1 /* 2 BlueZ - Bluetooth protocol stack for Linux 3 Copyright (C) 2000-2001 Qualcomm Incorporated 4 Copyright (C) 2009-2010 Gustavo F. Padovan <gustavo@padovan.org> 5 Copyright (C) 2010 Google Inc. 6 Copyright (C) 2011 ProFUSION Embedded Systems 7 Copyright (c) 2012 Code Aurora Forum. All rights reserved. 8 9 Written 2000,2001 by Maxim Krasnyansky <maxk@qualcomm.com> 10 11 This program is free software; you can redistribute it and/or modify 12 it under the terms of the GNU General Public License version 2 as 13 published by the Free Software Foundation; 14 15 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 16 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. 18 IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY 19 CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES 20 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 21 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 22 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 23 24 ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS, 25 COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS 26 SOFTWARE IS DISCLAIMED. 27 */ 28 29 /* Bluetooth L2CAP core. */ 30 31 #include <linux/module.h> 32 33 #include <linux/debugfs.h> 34 #include <linux/crc16.h> 35 #include <linux/filter.h> 36 37 #include <net/bluetooth/bluetooth.h> 38 #include <net/bluetooth/hci_core.h> 39 #include <net/bluetooth/l2cap.h> 40 41 #include "smp.h" 42 #include "a2mp.h" 43 #include "amp.h" 44 45 #define LE_FLOWCTL_MAX_CREDITS 65535 46 47 bool disable_ertm; 48 bool enable_ecred = IS_ENABLED(CONFIG_BT_LE_L2CAP_ECRED); 49 50 static u32 l2cap_feat_mask = L2CAP_FEAT_FIXED_CHAN | L2CAP_FEAT_UCD; 51 52 static LIST_HEAD(chan_list); 53 static DEFINE_RWLOCK(chan_list_lock); 54 55 static struct sk_buff *l2cap_build_cmd(struct l2cap_conn *conn, 56 u8 code, u8 ident, u16 dlen, void *data); 57 static void l2cap_send_cmd(struct l2cap_conn *conn, u8 ident, u8 code, u16 len, 58 void *data); 59 static int l2cap_build_conf_req(struct l2cap_chan *chan, void *data, size_t data_size); 60 static void l2cap_send_disconn_req(struct l2cap_chan *chan, int err); 61 62 static void l2cap_tx(struct l2cap_chan *chan, struct l2cap_ctrl *control, 63 struct sk_buff_head *skbs, u8 event); 64 static void l2cap_retrans_timeout(struct work_struct *work); 65 static void l2cap_monitor_timeout(struct work_struct *work); 66 static void l2cap_ack_timeout(struct work_struct *work); 67 68 static inline u8 bdaddr_type(u8 link_type, u8 bdaddr_type) 69 { 70 if (link_type == LE_LINK) { 71 if (bdaddr_type == ADDR_LE_DEV_PUBLIC) 72 return BDADDR_LE_PUBLIC; 73 else 74 return BDADDR_LE_RANDOM; 75 } 76 77 return BDADDR_BREDR; 78 } 79 80 static inline u8 bdaddr_src_type(struct hci_conn *hcon) 81 { 82 return bdaddr_type(hcon->type, hcon->src_type); 83 } 84 85 static inline u8 bdaddr_dst_type(struct hci_conn *hcon) 86 { 87 return bdaddr_type(hcon->type, hcon->dst_type); 88 } 89 90 /* ---- L2CAP channels ---- */ 91 92 static struct l2cap_chan *__l2cap_get_chan_by_dcid(struct l2cap_conn *conn, 93 u16 cid) 94 { 95 struct l2cap_chan *c; 96 97 list_for_each_entry(c, &conn->chan_l, list) { 98 if (c->dcid == cid) 99 return c; 100 } 101 return NULL; 102 } 103 104 static struct l2cap_chan *__l2cap_get_chan_by_scid(struct l2cap_conn *conn, 105 u16 cid) 106 { 107 struct l2cap_chan *c; 108 109 list_for_each_entry(c, &conn->chan_l, list) { 110 if (c->scid == cid) 111 return c; 112 } 113 return NULL; 114 } 115 116 /* Find channel with given SCID. 117 * Returns a reference locked channel. 118 */ 119 static struct l2cap_chan *l2cap_get_chan_by_scid(struct l2cap_conn *conn, 120 u16 cid) 121 { 122 struct l2cap_chan *c; 123 124 mutex_lock(&conn->chan_lock); 125 c = __l2cap_get_chan_by_scid(conn, cid); 126 if (c) { 127 /* Only lock if chan reference is not 0 */ 128 c = l2cap_chan_hold_unless_zero(c); 129 if (c) 130 l2cap_chan_lock(c); 131 } 132 mutex_unlock(&conn->chan_lock); 133 134 return c; 135 } 136 137 /* Find channel with given DCID. 138 * Returns a reference locked channel. 139 */ 140 static struct l2cap_chan *l2cap_get_chan_by_dcid(struct l2cap_conn *conn, 141 u16 cid) 142 { 143 struct l2cap_chan *c; 144 145 mutex_lock(&conn->chan_lock); 146 c = __l2cap_get_chan_by_dcid(conn, cid); 147 if (c) { 148 /* Only lock if chan reference is not 0 */ 149 c = l2cap_chan_hold_unless_zero(c); 150 if (c) 151 l2cap_chan_lock(c); 152 } 153 mutex_unlock(&conn->chan_lock); 154 155 return c; 156 } 157 158 static struct l2cap_chan *__l2cap_get_chan_by_ident(struct l2cap_conn *conn, 159 u8 ident) 160 { 161 struct l2cap_chan *c; 162 163 list_for_each_entry(c, &conn->chan_l, list) { 164 if (c->ident == ident) 165 return c; 166 } 167 return NULL; 168 } 169 170 static struct l2cap_chan *l2cap_get_chan_by_ident(struct l2cap_conn *conn, 171 u8 ident) 172 { 173 struct l2cap_chan *c; 174 175 mutex_lock(&conn->chan_lock); 176 c = __l2cap_get_chan_by_ident(conn, ident); 177 if (c) { 178 /* Only lock if chan reference is not 0 */ 179 c = l2cap_chan_hold_unless_zero(c); 180 if (c) 181 l2cap_chan_lock(c); 182 } 183 mutex_unlock(&conn->chan_lock); 184 185 return c; 186 } 187 188 static struct l2cap_chan *__l2cap_global_chan_by_addr(__le16 psm, bdaddr_t *src, 189 u8 src_type) 190 { 191 struct l2cap_chan *c; 192 193 list_for_each_entry(c, &chan_list, global_l) { 194 if (src_type == BDADDR_BREDR && c->src_type != BDADDR_BREDR) 195 continue; 196 197 if (src_type != BDADDR_BREDR && c->src_type == BDADDR_BREDR) 198 continue; 199 200 if (c->sport == psm && !bacmp(&c->src, src)) 201 return c; 202 } 203 return NULL; 204 } 205 206 int l2cap_add_psm(struct l2cap_chan *chan, bdaddr_t *src, __le16 psm) 207 { 208 int err; 209 210 write_lock(&chan_list_lock); 211 212 if (psm && __l2cap_global_chan_by_addr(psm, src, chan->src_type)) { 213 err = -EADDRINUSE; 214 goto done; 215 } 216 217 if (psm) { 218 chan->psm = psm; 219 chan->sport = psm; 220 err = 0; 221 } else { 222 u16 p, start, end, incr; 223 224 if (chan->src_type == BDADDR_BREDR) { 225 start = L2CAP_PSM_DYN_START; 226 end = L2CAP_PSM_AUTO_END; 227 incr = 2; 228 } else { 229 start = L2CAP_PSM_LE_DYN_START; 230 end = L2CAP_PSM_LE_DYN_END; 231 incr = 1; 232 } 233 234 err = -EINVAL; 235 for (p = start; p <= end; p += incr) 236 if (!__l2cap_global_chan_by_addr(cpu_to_le16(p), src, 237 chan->src_type)) { 238 chan->psm = cpu_to_le16(p); 239 chan->sport = cpu_to_le16(p); 240 err = 0; 241 break; 242 } 243 } 244 245 done: 246 write_unlock(&chan_list_lock); 247 return err; 248 } 249 EXPORT_SYMBOL_GPL(l2cap_add_psm); 250 251 int l2cap_add_scid(struct l2cap_chan *chan, __u16 scid) 252 { 253 write_lock(&chan_list_lock); 254 255 /* Override the defaults (which are for conn-oriented) */ 256 chan->omtu = L2CAP_DEFAULT_MTU; 257 chan->chan_type = L2CAP_CHAN_FIXED; 258 259 chan->scid = scid; 260 261 write_unlock(&chan_list_lock); 262 263 return 0; 264 } 265 266 static u16 l2cap_alloc_cid(struct l2cap_conn *conn) 267 { 268 u16 cid, dyn_end; 269 270 if (conn->hcon->type == LE_LINK) 271 dyn_end = L2CAP_CID_LE_DYN_END; 272 else 273 dyn_end = L2CAP_CID_DYN_END; 274 275 for (cid = L2CAP_CID_DYN_START; cid <= dyn_end; cid++) { 276 if (!__l2cap_get_chan_by_scid(conn, cid)) 277 return cid; 278 } 279 280 return 0; 281 } 282 283 static void l2cap_state_change(struct l2cap_chan *chan, int state) 284 { 285 BT_DBG("chan %p %s -> %s", chan, state_to_string(chan->state), 286 state_to_string(state)); 287 288 chan->state = state; 289 chan->ops->state_change(chan, state, 0); 290 } 291 292 static inline void l2cap_state_change_and_error(struct l2cap_chan *chan, 293 int state, int err) 294 { 295 chan->state = state; 296 chan->ops->state_change(chan, chan->state, err); 297 } 298 299 static inline void l2cap_chan_set_err(struct l2cap_chan *chan, int err) 300 { 301 chan->ops->state_change(chan, chan->state, err); 302 } 303 304 static void __set_retrans_timer(struct l2cap_chan *chan) 305 { 306 if (!delayed_work_pending(&chan->monitor_timer) && 307 chan->retrans_timeout) { 308 l2cap_set_timer(chan, &chan->retrans_timer, 309 msecs_to_jiffies(chan->retrans_timeout)); 310 } 311 } 312 313 static void __set_monitor_timer(struct l2cap_chan *chan) 314 { 315 __clear_retrans_timer(chan); 316 if (chan->monitor_timeout) { 317 l2cap_set_timer(chan, &chan->monitor_timer, 318 msecs_to_jiffies(chan->monitor_timeout)); 319 } 320 } 321 322 static struct sk_buff *l2cap_ertm_seq_in_queue(struct sk_buff_head *head, 323 u16 seq) 324 { 325 struct sk_buff *skb; 326 327 skb_queue_walk(head, skb) { 328 if (bt_cb(skb)->l2cap.txseq == seq) 329 return skb; 330 } 331 332 return NULL; 333 } 334 335 /* ---- L2CAP sequence number lists ---- */ 336 337 /* For ERTM, ordered lists of sequence numbers must be tracked for 338 * SREJ requests that are received and for frames that are to be 339 * retransmitted. These seq_list functions implement a singly-linked 340 * list in an array, where membership in the list can also be checked 341 * in constant time. Items can also be added to the tail of the list 342 * and removed from the head in constant time, without further memory 343 * allocs or frees. 344 */ 345 346 static int l2cap_seq_list_init(struct l2cap_seq_list *seq_list, u16 size) 347 { 348 size_t alloc_size, i; 349 350 /* Allocated size is a power of 2 to map sequence numbers 351 * (which may be up to 14 bits) in to a smaller array that is 352 * sized for the negotiated ERTM transmit windows. 353 */ 354 alloc_size = roundup_pow_of_two(size); 355 356 seq_list->list = kmalloc_array(alloc_size, sizeof(u16), GFP_KERNEL); 357 if (!seq_list->list) 358 return -ENOMEM; 359 360 seq_list->mask = alloc_size - 1; 361 seq_list->head = L2CAP_SEQ_LIST_CLEAR; 362 seq_list->tail = L2CAP_SEQ_LIST_CLEAR; 363 for (i = 0; i < alloc_size; i++) 364 seq_list->list[i] = L2CAP_SEQ_LIST_CLEAR; 365 366 return 0; 367 } 368 369 static inline void l2cap_seq_list_free(struct l2cap_seq_list *seq_list) 370 { 371 kfree(seq_list->list); 372 } 373 374 static inline bool l2cap_seq_list_contains(struct l2cap_seq_list *seq_list, 375 u16 seq) 376 { 377 /* Constant-time check for list membership */ 378 return seq_list->list[seq & seq_list->mask] != L2CAP_SEQ_LIST_CLEAR; 379 } 380 381 static inline u16 l2cap_seq_list_pop(struct l2cap_seq_list *seq_list) 382 { 383 u16 seq = seq_list->head; 384 u16 mask = seq_list->mask; 385 386 seq_list->head = seq_list->list[seq & mask]; 387 seq_list->list[seq & mask] = L2CAP_SEQ_LIST_CLEAR; 388 389 if (seq_list->head == L2CAP_SEQ_LIST_TAIL) { 390 seq_list->head = L2CAP_SEQ_LIST_CLEAR; 391 seq_list->tail = L2CAP_SEQ_LIST_CLEAR; 392 } 393 394 return seq; 395 } 396 397 static void l2cap_seq_list_clear(struct l2cap_seq_list *seq_list) 398 { 399 u16 i; 400 401 if (seq_list->head == L2CAP_SEQ_LIST_CLEAR) 402 return; 403 404 for (i = 0; i <= seq_list->mask; i++) 405 seq_list->list[i] = L2CAP_SEQ_LIST_CLEAR; 406 407 seq_list->head = L2CAP_SEQ_LIST_CLEAR; 408 seq_list->tail = L2CAP_SEQ_LIST_CLEAR; 409 } 410 411 static void l2cap_seq_list_append(struct l2cap_seq_list *seq_list, u16 seq) 412 { 413 u16 mask = seq_list->mask; 414 415 /* All appends happen in constant time */ 416 417 if (seq_list->list[seq & mask] != L2CAP_SEQ_LIST_CLEAR) 418 return; 419 420 if (seq_list->tail == L2CAP_SEQ_LIST_CLEAR) 421 seq_list->head = seq; 422 else 423 seq_list->list[seq_list->tail & mask] = seq; 424 425 seq_list->tail = seq; 426 seq_list->list[seq & mask] = L2CAP_SEQ_LIST_TAIL; 427 } 428 429 static void l2cap_chan_timeout(struct work_struct *work) 430 { 431 struct l2cap_chan *chan = container_of(work, struct l2cap_chan, 432 chan_timer.work); 433 struct l2cap_conn *conn = chan->conn; 434 int reason; 435 436 BT_DBG("chan %p state %s", chan, state_to_string(chan->state)); 437 438 mutex_lock(&conn->chan_lock); 439 /* __set_chan_timer() calls l2cap_chan_hold(chan) while scheduling 440 * this work. No need to call l2cap_chan_hold(chan) here again. 441 */ 442 l2cap_chan_lock(chan); 443 444 if (chan->state == BT_CONNECTED || chan->state == BT_CONFIG) 445 reason = ECONNREFUSED; 446 else if (chan->state == BT_CONNECT && 447 chan->sec_level != BT_SECURITY_SDP) 448 reason = ECONNREFUSED; 449 else 450 reason = ETIMEDOUT; 451 452 l2cap_chan_close(chan, reason); 453 454 chan->ops->close(chan); 455 456 l2cap_chan_unlock(chan); 457 l2cap_chan_put(chan); 458 459 mutex_unlock(&conn->chan_lock); 460 } 461 462 struct l2cap_chan *l2cap_chan_create(void) 463 { 464 struct l2cap_chan *chan; 465 466 chan = kzalloc(sizeof(*chan), GFP_ATOMIC); 467 if (!chan) 468 return NULL; 469 470 skb_queue_head_init(&chan->tx_q); 471 skb_queue_head_init(&chan->srej_q); 472 mutex_init(&chan->lock); 473 474 /* Set default lock nesting level */ 475 atomic_set(&chan->nesting, L2CAP_NESTING_NORMAL); 476 477 write_lock(&chan_list_lock); 478 list_add(&chan->global_l, &chan_list); 479 write_unlock(&chan_list_lock); 480 481 INIT_DELAYED_WORK(&chan->chan_timer, l2cap_chan_timeout); 482 INIT_DELAYED_WORK(&chan->retrans_timer, l2cap_retrans_timeout); 483 INIT_DELAYED_WORK(&chan->monitor_timer, l2cap_monitor_timeout); 484 INIT_DELAYED_WORK(&chan->ack_timer, l2cap_ack_timeout); 485 486 chan->state = BT_OPEN; 487 488 kref_init(&chan->kref); 489 490 /* This flag is cleared in l2cap_chan_ready() */ 491 set_bit(CONF_NOT_COMPLETE, &chan->conf_state); 492 493 BT_DBG("chan %p", chan); 494 495 return chan; 496 } 497 EXPORT_SYMBOL_GPL(l2cap_chan_create); 498 499 static void l2cap_chan_destroy(struct kref *kref) 500 { 501 struct l2cap_chan *chan = container_of(kref, struct l2cap_chan, kref); 502 503 BT_DBG("chan %p", chan); 504 505 write_lock(&chan_list_lock); 506 list_del(&chan->global_l); 507 write_unlock(&chan_list_lock); 508 509 kfree(chan); 510 } 511 512 void l2cap_chan_hold(struct l2cap_chan *c) 513 { 514 BT_DBG("chan %p orig refcnt %u", c, kref_read(&c->kref)); 515 516 kref_get(&c->kref); 517 } 518 519 struct l2cap_chan *l2cap_chan_hold_unless_zero(struct l2cap_chan *c) 520 { 521 BT_DBG("chan %p orig refcnt %u", c, kref_read(&c->kref)); 522 523 if (!kref_get_unless_zero(&c->kref)) 524 return NULL; 525 526 return c; 527 } 528 529 void l2cap_chan_put(struct l2cap_chan *c) 530 { 531 BT_DBG("chan %p orig refcnt %u", c, kref_read(&c->kref)); 532 533 kref_put(&c->kref, l2cap_chan_destroy); 534 } 535 EXPORT_SYMBOL_GPL(l2cap_chan_put); 536 537 void l2cap_chan_set_defaults(struct l2cap_chan *chan) 538 { 539 chan->fcs = L2CAP_FCS_CRC16; 540 chan->max_tx = L2CAP_DEFAULT_MAX_TX; 541 chan->tx_win = L2CAP_DEFAULT_TX_WINDOW; 542 chan->tx_win_max = L2CAP_DEFAULT_TX_WINDOW; 543 chan->remote_max_tx = chan->max_tx; 544 chan->remote_tx_win = chan->tx_win; 545 chan->ack_win = L2CAP_DEFAULT_TX_WINDOW; 546 chan->sec_level = BT_SECURITY_LOW; 547 chan->flush_to = L2CAP_DEFAULT_FLUSH_TO; 548 chan->retrans_timeout = L2CAP_DEFAULT_RETRANS_TO; 549 chan->monitor_timeout = L2CAP_DEFAULT_MONITOR_TO; 550 551 chan->conf_state = 0; 552 set_bit(CONF_NOT_COMPLETE, &chan->conf_state); 553 554 set_bit(FLAG_FORCE_ACTIVE, &chan->flags); 555 } 556 EXPORT_SYMBOL_GPL(l2cap_chan_set_defaults); 557 558 static void l2cap_le_flowctl_init(struct l2cap_chan *chan, u16 tx_credits) 559 { 560 chan->sdu = NULL; 561 chan->sdu_last_frag = NULL; 562 chan->sdu_len = 0; 563 chan->tx_credits = tx_credits; 564 /* Derive MPS from connection MTU to stop HCI fragmentation */ 565 chan->mps = min_t(u16, chan->imtu, chan->conn->mtu - L2CAP_HDR_SIZE); 566 /* Give enough credits for a full packet */ 567 chan->rx_credits = (chan->imtu / chan->mps) + 1; 568 569 skb_queue_head_init(&chan->tx_q); 570 } 571 572 static void l2cap_ecred_init(struct l2cap_chan *chan, u16 tx_credits) 573 { 574 l2cap_le_flowctl_init(chan, tx_credits); 575 576 /* L2CAP implementations shall support a minimum MPS of 64 octets */ 577 if (chan->mps < L2CAP_ECRED_MIN_MPS) { 578 chan->mps = L2CAP_ECRED_MIN_MPS; 579 chan->rx_credits = (chan->imtu / chan->mps) + 1; 580 } 581 } 582 583 void __l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan) 584 { 585 BT_DBG("conn %p, psm 0x%2.2x, dcid 0x%4.4x", conn, 586 __le16_to_cpu(chan->psm), chan->dcid); 587 588 conn->disc_reason = HCI_ERROR_REMOTE_USER_TERM; 589 590 chan->conn = conn; 591 592 switch (chan->chan_type) { 593 case L2CAP_CHAN_CONN_ORIENTED: 594 /* Alloc CID for connection-oriented socket */ 595 chan->scid = l2cap_alloc_cid(conn); 596 if (conn->hcon->type == ACL_LINK) 597 chan->omtu = L2CAP_DEFAULT_MTU; 598 break; 599 600 case L2CAP_CHAN_CONN_LESS: 601 /* Connectionless socket */ 602 chan->scid = L2CAP_CID_CONN_LESS; 603 chan->dcid = L2CAP_CID_CONN_LESS; 604 chan->omtu = L2CAP_DEFAULT_MTU; 605 break; 606 607 case L2CAP_CHAN_FIXED: 608 /* Caller will set CID and CID specific MTU values */ 609 break; 610 611 default: 612 /* Raw socket can send/recv signalling messages only */ 613 chan->scid = L2CAP_CID_SIGNALING; 614 chan->dcid = L2CAP_CID_SIGNALING; 615 chan->omtu = L2CAP_DEFAULT_MTU; 616 } 617 618 chan->local_id = L2CAP_BESTEFFORT_ID; 619 chan->local_stype = L2CAP_SERV_BESTEFFORT; 620 chan->local_msdu = L2CAP_DEFAULT_MAX_SDU_SIZE; 621 chan->local_sdu_itime = L2CAP_DEFAULT_SDU_ITIME; 622 chan->local_acc_lat = L2CAP_DEFAULT_ACC_LAT; 623 chan->local_flush_to = L2CAP_EFS_DEFAULT_FLUSH_TO; 624 625 l2cap_chan_hold(chan); 626 627 /* Only keep a reference for fixed channels if they requested it */ 628 if (chan->chan_type != L2CAP_CHAN_FIXED || 629 test_bit(FLAG_HOLD_HCI_CONN, &chan->flags)) 630 hci_conn_hold(conn->hcon); 631 632 list_add(&chan->list, &conn->chan_l); 633 } 634 635 void l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan) 636 { 637 mutex_lock(&conn->chan_lock); 638 __l2cap_chan_add(conn, chan); 639 mutex_unlock(&conn->chan_lock); 640 } 641 642 void l2cap_chan_del(struct l2cap_chan *chan, int err) 643 { 644 struct l2cap_conn *conn = chan->conn; 645 646 __clear_chan_timer(chan); 647 648 BT_DBG("chan %p, conn %p, err %d, state %s", chan, conn, err, 649 state_to_string(chan->state)); 650 651 chan->ops->teardown(chan, err); 652 653 if (conn) { 654 struct amp_mgr *mgr = conn->hcon->amp_mgr; 655 /* Delete from channel list */ 656 list_del(&chan->list); 657 658 l2cap_chan_put(chan); 659 660 chan->conn = NULL; 661 662 /* Reference was only held for non-fixed channels or 663 * fixed channels that explicitly requested it using the 664 * FLAG_HOLD_HCI_CONN flag. 665 */ 666 if (chan->chan_type != L2CAP_CHAN_FIXED || 667 test_bit(FLAG_HOLD_HCI_CONN, &chan->flags)) 668 hci_conn_drop(conn->hcon); 669 670 if (mgr && mgr->bredr_chan == chan) 671 mgr->bredr_chan = NULL; 672 } 673 674 if (chan->hs_hchan) { 675 struct hci_chan *hs_hchan = chan->hs_hchan; 676 677 BT_DBG("chan %p disconnect hs_hchan %p", chan, hs_hchan); 678 amp_disconnect_logical_link(hs_hchan); 679 } 680 681 if (test_bit(CONF_NOT_COMPLETE, &chan->conf_state)) 682 return; 683 684 switch (chan->mode) { 685 case L2CAP_MODE_BASIC: 686 break; 687 688 case L2CAP_MODE_LE_FLOWCTL: 689 case L2CAP_MODE_EXT_FLOWCTL: 690 skb_queue_purge(&chan->tx_q); 691 break; 692 693 case L2CAP_MODE_ERTM: 694 __clear_retrans_timer(chan); 695 __clear_monitor_timer(chan); 696 __clear_ack_timer(chan); 697 698 skb_queue_purge(&chan->srej_q); 699 700 l2cap_seq_list_free(&chan->srej_list); 701 l2cap_seq_list_free(&chan->retrans_list); 702 fallthrough; 703 704 case L2CAP_MODE_STREAMING: 705 skb_queue_purge(&chan->tx_q); 706 break; 707 } 708 } 709 EXPORT_SYMBOL_GPL(l2cap_chan_del); 710 711 static void __l2cap_chan_list_id(struct l2cap_conn *conn, u16 id, 712 l2cap_chan_func_t func, void *data) 713 { 714 struct l2cap_chan *chan, *l; 715 716 list_for_each_entry_safe(chan, l, &conn->chan_l, list) { 717 if (chan->ident == id) 718 func(chan, data); 719 } 720 } 721 722 static void __l2cap_chan_list(struct l2cap_conn *conn, l2cap_chan_func_t func, 723 void *data) 724 { 725 struct l2cap_chan *chan; 726 727 list_for_each_entry(chan, &conn->chan_l, list) { 728 func(chan, data); 729 } 730 } 731 732 void l2cap_chan_list(struct l2cap_conn *conn, l2cap_chan_func_t func, 733 void *data) 734 { 735 if (!conn) 736 return; 737 738 mutex_lock(&conn->chan_lock); 739 __l2cap_chan_list(conn, func, data); 740 mutex_unlock(&conn->chan_lock); 741 } 742 743 EXPORT_SYMBOL_GPL(l2cap_chan_list); 744 745 static void l2cap_conn_update_id_addr(struct work_struct *work) 746 { 747 struct l2cap_conn *conn = container_of(work, struct l2cap_conn, 748 id_addr_timer.work); 749 struct hci_conn *hcon = conn->hcon; 750 struct l2cap_chan *chan; 751 752 mutex_lock(&conn->chan_lock); 753 754 list_for_each_entry(chan, &conn->chan_l, list) { 755 l2cap_chan_lock(chan); 756 bacpy(&chan->dst, &hcon->dst); 757 chan->dst_type = bdaddr_dst_type(hcon); 758 l2cap_chan_unlock(chan); 759 } 760 761 mutex_unlock(&conn->chan_lock); 762 } 763 764 static void l2cap_chan_le_connect_reject(struct l2cap_chan *chan) 765 { 766 struct l2cap_conn *conn = chan->conn; 767 struct l2cap_le_conn_rsp rsp; 768 u16 result; 769 770 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) 771 result = L2CAP_CR_LE_AUTHORIZATION; 772 else 773 result = L2CAP_CR_LE_BAD_PSM; 774 775 l2cap_state_change(chan, BT_DISCONN); 776 777 rsp.dcid = cpu_to_le16(chan->scid); 778 rsp.mtu = cpu_to_le16(chan->imtu); 779 rsp.mps = cpu_to_le16(chan->mps); 780 rsp.credits = cpu_to_le16(chan->rx_credits); 781 rsp.result = cpu_to_le16(result); 782 783 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_RSP, sizeof(rsp), 784 &rsp); 785 } 786 787 static void l2cap_chan_ecred_connect_reject(struct l2cap_chan *chan) 788 { 789 l2cap_state_change(chan, BT_DISCONN); 790 791 __l2cap_ecred_conn_rsp_defer(chan); 792 } 793 794 static void l2cap_chan_connect_reject(struct l2cap_chan *chan) 795 { 796 struct l2cap_conn *conn = chan->conn; 797 struct l2cap_conn_rsp rsp; 798 u16 result; 799 800 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) 801 result = L2CAP_CR_SEC_BLOCK; 802 else 803 result = L2CAP_CR_BAD_PSM; 804 805 l2cap_state_change(chan, BT_DISCONN); 806 807 rsp.scid = cpu_to_le16(chan->dcid); 808 rsp.dcid = cpu_to_le16(chan->scid); 809 rsp.result = cpu_to_le16(result); 810 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO); 811 812 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP, sizeof(rsp), &rsp); 813 } 814 815 void l2cap_chan_close(struct l2cap_chan *chan, int reason) 816 { 817 struct l2cap_conn *conn = chan->conn; 818 819 BT_DBG("chan %p state %s", chan, state_to_string(chan->state)); 820 821 switch (chan->state) { 822 case BT_LISTEN: 823 chan->ops->teardown(chan, 0); 824 break; 825 826 case BT_CONNECTED: 827 case BT_CONFIG: 828 if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED) { 829 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan)); 830 l2cap_send_disconn_req(chan, reason); 831 } else 832 l2cap_chan_del(chan, reason); 833 break; 834 835 case BT_CONNECT2: 836 if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED) { 837 if (conn->hcon->type == ACL_LINK) 838 l2cap_chan_connect_reject(chan); 839 else if (conn->hcon->type == LE_LINK) { 840 switch (chan->mode) { 841 case L2CAP_MODE_LE_FLOWCTL: 842 l2cap_chan_le_connect_reject(chan); 843 break; 844 case L2CAP_MODE_EXT_FLOWCTL: 845 l2cap_chan_ecred_connect_reject(chan); 846 return; 847 } 848 } 849 } 850 851 l2cap_chan_del(chan, reason); 852 break; 853 854 case BT_CONNECT: 855 case BT_DISCONN: 856 l2cap_chan_del(chan, reason); 857 break; 858 859 default: 860 chan->ops->teardown(chan, 0); 861 break; 862 } 863 } 864 EXPORT_SYMBOL(l2cap_chan_close); 865 866 static inline u8 l2cap_get_auth_type(struct l2cap_chan *chan) 867 { 868 switch (chan->chan_type) { 869 case L2CAP_CHAN_RAW: 870 switch (chan->sec_level) { 871 case BT_SECURITY_HIGH: 872 case BT_SECURITY_FIPS: 873 return HCI_AT_DEDICATED_BONDING_MITM; 874 case BT_SECURITY_MEDIUM: 875 return HCI_AT_DEDICATED_BONDING; 876 default: 877 return HCI_AT_NO_BONDING; 878 } 879 break; 880 case L2CAP_CHAN_CONN_LESS: 881 if (chan->psm == cpu_to_le16(L2CAP_PSM_3DSP)) { 882 if (chan->sec_level == BT_SECURITY_LOW) 883 chan->sec_level = BT_SECURITY_SDP; 884 } 885 if (chan->sec_level == BT_SECURITY_HIGH || 886 chan->sec_level == BT_SECURITY_FIPS) 887 return HCI_AT_NO_BONDING_MITM; 888 else 889 return HCI_AT_NO_BONDING; 890 break; 891 case L2CAP_CHAN_CONN_ORIENTED: 892 if (chan->psm == cpu_to_le16(L2CAP_PSM_SDP)) { 893 if (chan->sec_level == BT_SECURITY_LOW) 894 chan->sec_level = BT_SECURITY_SDP; 895 896 if (chan->sec_level == BT_SECURITY_HIGH || 897 chan->sec_level == BT_SECURITY_FIPS) 898 return HCI_AT_NO_BONDING_MITM; 899 else 900 return HCI_AT_NO_BONDING; 901 } 902 fallthrough; 903 904 default: 905 switch (chan->sec_level) { 906 case BT_SECURITY_HIGH: 907 case BT_SECURITY_FIPS: 908 return HCI_AT_GENERAL_BONDING_MITM; 909 case BT_SECURITY_MEDIUM: 910 return HCI_AT_GENERAL_BONDING; 911 default: 912 return HCI_AT_NO_BONDING; 913 } 914 break; 915 } 916 } 917 918 /* Service level security */ 919 int l2cap_chan_check_security(struct l2cap_chan *chan, bool initiator) 920 { 921 struct l2cap_conn *conn = chan->conn; 922 __u8 auth_type; 923 924 if (conn->hcon->type == LE_LINK) 925 return smp_conn_security(conn->hcon, chan->sec_level); 926 927 auth_type = l2cap_get_auth_type(chan); 928 929 return hci_conn_security(conn->hcon, chan->sec_level, auth_type, 930 initiator); 931 } 932 933 static u8 l2cap_get_ident(struct l2cap_conn *conn) 934 { 935 u8 id; 936 937 /* Get next available identificator. 938 * 1 - 128 are used by kernel. 939 * 129 - 199 are reserved. 940 * 200 - 254 are used by utilities like l2ping, etc. 941 */ 942 943 mutex_lock(&conn->ident_lock); 944 945 if (++conn->tx_ident > 128) 946 conn->tx_ident = 1; 947 948 id = conn->tx_ident; 949 950 mutex_unlock(&conn->ident_lock); 951 952 return id; 953 } 954 955 static void l2cap_send_cmd(struct l2cap_conn *conn, u8 ident, u8 code, u16 len, 956 void *data) 957 { 958 struct sk_buff *skb = l2cap_build_cmd(conn, code, ident, len, data); 959 u8 flags; 960 961 BT_DBG("code 0x%2.2x", code); 962 963 if (!skb) 964 return; 965 966 /* Use NO_FLUSH if supported or we have an LE link (which does 967 * not support auto-flushing packets) */ 968 if (lmp_no_flush_capable(conn->hcon->hdev) || 969 conn->hcon->type == LE_LINK) 970 flags = ACL_START_NO_FLUSH; 971 else 972 flags = ACL_START; 973 974 bt_cb(skb)->force_active = BT_POWER_FORCE_ACTIVE_ON; 975 skb->priority = HCI_PRIO_MAX; 976 977 hci_send_acl(conn->hchan, skb, flags); 978 } 979 980 static bool __chan_is_moving(struct l2cap_chan *chan) 981 { 982 return chan->move_state != L2CAP_MOVE_STABLE && 983 chan->move_state != L2CAP_MOVE_WAIT_PREPARE; 984 } 985 986 static void l2cap_do_send(struct l2cap_chan *chan, struct sk_buff *skb) 987 { 988 struct hci_conn *hcon = chan->conn->hcon; 989 u16 flags; 990 991 BT_DBG("chan %p, skb %p len %d priority %u", chan, skb, skb->len, 992 skb->priority); 993 994 if (chan->hs_hcon && !__chan_is_moving(chan)) { 995 if (chan->hs_hchan) 996 hci_send_acl(chan->hs_hchan, skb, ACL_COMPLETE); 997 else 998 kfree_skb(skb); 999 1000 return; 1001 } 1002 1003 /* Use NO_FLUSH for LE links (where this is the only option) or 1004 * if the BR/EDR link supports it and flushing has not been 1005 * explicitly requested (through FLAG_FLUSHABLE). 1006 */ 1007 if (hcon->type == LE_LINK || 1008 (!test_bit(FLAG_FLUSHABLE, &chan->flags) && 1009 lmp_no_flush_capable(hcon->hdev))) 1010 flags = ACL_START_NO_FLUSH; 1011 else 1012 flags = ACL_START; 1013 1014 bt_cb(skb)->force_active = test_bit(FLAG_FORCE_ACTIVE, &chan->flags); 1015 hci_send_acl(chan->conn->hchan, skb, flags); 1016 } 1017 1018 static void __unpack_enhanced_control(u16 enh, struct l2cap_ctrl *control) 1019 { 1020 control->reqseq = (enh & L2CAP_CTRL_REQSEQ) >> L2CAP_CTRL_REQSEQ_SHIFT; 1021 control->final = (enh & L2CAP_CTRL_FINAL) >> L2CAP_CTRL_FINAL_SHIFT; 1022 1023 if (enh & L2CAP_CTRL_FRAME_TYPE) { 1024 /* S-Frame */ 1025 control->sframe = 1; 1026 control->poll = (enh & L2CAP_CTRL_POLL) >> L2CAP_CTRL_POLL_SHIFT; 1027 control->super = (enh & L2CAP_CTRL_SUPERVISE) >> L2CAP_CTRL_SUPER_SHIFT; 1028 1029 control->sar = 0; 1030 control->txseq = 0; 1031 } else { 1032 /* I-Frame */ 1033 control->sframe = 0; 1034 control->sar = (enh & L2CAP_CTRL_SAR) >> L2CAP_CTRL_SAR_SHIFT; 1035 control->txseq = (enh & L2CAP_CTRL_TXSEQ) >> L2CAP_CTRL_TXSEQ_SHIFT; 1036 1037 control->poll = 0; 1038 control->super = 0; 1039 } 1040 } 1041 1042 static void __unpack_extended_control(u32 ext, struct l2cap_ctrl *control) 1043 { 1044 control->reqseq = (ext & L2CAP_EXT_CTRL_REQSEQ) >> L2CAP_EXT_CTRL_REQSEQ_SHIFT; 1045 control->final = (ext & L2CAP_EXT_CTRL_FINAL) >> L2CAP_EXT_CTRL_FINAL_SHIFT; 1046 1047 if (ext & L2CAP_EXT_CTRL_FRAME_TYPE) { 1048 /* S-Frame */ 1049 control->sframe = 1; 1050 control->poll = (ext & L2CAP_EXT_CTRL_POLL) >> L2CAP_EXT_CTRL_POLL_SHIFT; 1051 control->super = (ext & L2CAP_EXT_CTRL_SUPERVISE) >> L2CAP_EXT_CTRL_SUPER_SHIFT; 1052 1053 control->sar = 0; 1054 control->txseq = 0; 1055 } else { 1056 /* I-Frame */ 1057 control->sframe = 0; 1058 control->sar = (ext & L2CAP_EXT_CTRL_SAR) >> L2CAP_EXT_CTRL_SAR_SHIFT; 1059 control->txseq = (ext & L2CAP_EXT_CTRL_TXSEQ) >> L2CAP_EXT_CTRL_TXSEQ_SHIFT; 1060 1061 control->poll = 0; 1062 control->super = 0; 1063 } 1064 } 1065 1066 static inline void __unpack_control(struct l2cap_chan *chan, 1067 struct sk_buff *skb) 1068 { 1069 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) { 1070 __unpack_extended_control(get_unaligned_le32(skb->data), 1071 &bt_cb(skb)->l2cap); 1072 skb_pull(skb, L2CAP_EXT_CTRL_SIZE); 1073 } else { 1074 __unpack_enhanced_control(get_unaligned_le16(skb->data), 1075 &bt_cb(skb)->l2cap); 1076 skb_pull(skb, L2CAP_ENH_CTRL_SIZE); 1077 } 1078 } 1079 1080 static u32 __pack_extended_control(struct l2cap_ctrl *control) 1081 { 1082 u32 packed; 1083 1084 packed = control->reqseq << L2CAP_EXT_CTRL_REQSEQ_SHIFT; 1085 packed |= control->final << L2CAP_EXT_CTRL_FINAL_SHIFT; 1086 1087 if (control->sframe) { 1088 packed |= control->poll << L2CAP_EXT_CTRL_POLL_SHIFT; 1089 packed |= control->super << L2CAP_EXT_CTRL_SUPER_SHIFT; 1090 packed |= L2CAP_EXT_CTRL_FRAME_TYPE; 1091 } else { 1092 packed |= control->sar << L2CAP_EXT_CTRL_SAR_SHIFT; 1093 packed |= control->txseq << L2CAP_EXT_CTRL_TXSEQ_SHIFT; 1094 } 1095 1096 return packed; 1097 } 1098 1099 static u16 __pack_enhanced_control(struct l2cap_ctrl *control) 1100 { 1101 u16 packed; 1102 1103 packed = control->reqseq << L2CAP_CTRL_REQSEQ_SHIFT; 1104 packed |= control->final << L2CAP_CTRL_FINAL_SHIFT; 1105 1106 if (control->sframe) { 1107 packed |= control->poll << L2CAP_CTRL_POLL_SHIFT; 1108 packed |= control->super << L2CAP_CTRL_SUPER_SHIFT; 1109 packed |= L2CAP_CTRL_FRAME_TYPE; 1110 } else { 1111 packed |= control->sar << L2CAP_CTRL_SAR_SHIFT; 1112 packed |= control->txseq << L2CAP_CTRL_TXSEQ_SHIFT; 1113 } 1114 1115 return packed; 1116 } 1117 1118 static inline void __pack_control(struct l2cap_chan *chan, 1119 struct l2cap_ctrl *control, 1120 struct sk_buff *skb) 1121 { 1122 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) { 1123 put_unaligned_le32(__pack_extended_control(control), 1124 skb->data + L2CAP_HDR_SIZE); 1125 } else { 1126 put_unaligned_le16(__pack_enhanced_control(control), 1127 skb->data + L2CAP_HDR_SIZE); 1128 } 1129 } 1130 1131 static inline unsigned int __ertm_hdr_size(struct l2cap_chan *chan) 1132 { 1133 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) 1134 return L2CAP_EXT_HDR_SIZE; 1135 else 1136 return L2CAP_ENH_HDR_SIZE; 1137 } 1138 1139 static struct sk_buff *l2cap_create_sframe_pdu(struct l2cap_chan *chan, 1140 u32 control) 1141 { 1142 struct sk_buff *skb; 1143 struct l2cap_hdr *lh; 1144 int hlen = __ertm_hdr_size(chan); 1145 1146 if (chan->fcs == L2CAP_FCS_CRC16) 1147 hlen += L2CAP_FCS_SIZE; 1148 1149 skb = bt_skb_alloc(hlen, GFP_KERNEL); 1150 1151 if (!skb) 1152 return ERR_PTR(-ENOMEM); 1153 1154 lh = skb_put(skb, L2CAP_HDR_SIZE); 1155 lh->len = cpu_to_le16(hlen - L2CAP_HDR_SIZE); 1156 lh->cid = cpu_to_le16(chan->dcid); 1157 1158 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) 1159 put_unaligned_le32(control, skb_put(skb, L2CAP_EXT_CTRL_SIZE)); 1160 else 1161 put_unaligned_le16(control, skb_put(skb, L2CAP_ENH_CTRL_SIZE)); 1162 1163 if (chan->fcs == L2CAP_FCS_CRC16) { 1164 u16 fcs = crc16(0, (u8 *)skb->data, skb->len); 1165 put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE)); 1166 } 1167 1168 skb->priority = HCI_PRIO_MAX; 1169 return skb; 1170 } 1171 1172 static void l2cap_send_sframe(struct l2cap_chan *chan, 1173 struct l2cap_ctrl *control) 1174 { 1175 struct sk_buff *skb; 1176 u32 control_field; 1177 1178 BT_DBG("chan %p, control %p", chan, control); 1179 1180 if (!control->sframe) 1181 return; 1182 1183 if (__chan_is_moving(chan)) 1184 return; 1185 1186 if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state) && 1187 !control->poll) 1188 control->final = 1; 1189 1190 if (control->super == L2CAP_SUPER_RR) 1191 clear_bit(CONN_RNR_SENT, &chan->conn_state); 1192 else if (control->super == L2CAP_SUPER_RNR) 1193 set_bit(CONN_RNR_SENT, &chan->conn_state); 1194 1195 if (control->super != L2CAP_SUPER_SREJ) { 1196 chan->last_acked_seq = control->reqseq; 1197 __clear_ack_timer(chan); 1198 } 1199 1200 BT_DBG("reqseq %d, final %d, poll %d, super %d", control->reqseq, 1201 control->final, control->poll, control->super); 1202 1203 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) 1204 control_field = __pack_extended_control(control); 1205 else 1206 control_field = __pack_enhanced_control(control); 1207 1208 skb = l2cap_create_sframe_pdu(chan, control_field); 1209 if (!IS_ERR(skb)) 1210 l2cap_do_send(chan, skb); 1211 } 1212 1213 static void l2cap_send_rr_or_rnr(struct l2cap_chan *chan, bool poll) 1214 { 1215 struct l2cap_ctrl control; 1216 1217 BT_DBG("chan %p, poll %d", chan, poll); 1218 1219 memset(&control, 0, sizeof(control)); 1220 control.sframe = 1; 1221 control.poll = poll; 1222 1223 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) 1224 control.super = L2CAP_SUPER_RNR; 1225 else 1226 control.super = L2CAP_SUPER_RR; 1227 1228 control.reqseq = chan->buffer_seq; 1229 l2cap_send_sframe(chan, &control); 1230 } 1231 1232 static inline int __l2cap_no_conn_pending(struct l2cap_chan *chan) 1233 { 1234 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) 1235 return true; 1236 1237 return !test_bit(CONF_CONNECT_PEND, &chan->conf_state); 1238 } 1239 1240 static bool __amp_capable(struct l2cap_chan *chan) 1241 { 1242 struct l2cap_conn *conn = chan->conn; 1243 struct hci_dev *hdev; 1244 bool amp_available = false; 1245 1246 if (!(conn->local_fixed_chan & L2CAP_FC_A2MP)) 1247 return false; 1248 1249 if (!(conn->remote_fixed_chan & L2CAP_FC_A2MP)) 1250 return false; 1251 1252 read_lock(&hci_dev_list_lock); 1253 list_for_each_entry(hdev, &hci_dev_list, list) { 1254 if (hdev->amp_type != AMP_TYPE_BREDR && 1255 test_bit(HCI_UP, &hdev->flags)) { 1256 amp_available = true; 1257 break; 1258 } 1259 } 1260 read_unlock(&hci_dev_list_lock); 1261 1262 if (chan->chan_policy == BT_CHANNEL_POLICY_AMP_PREFERRED) 1263 return amp_available; 1264 1265 return false; 1266 } 1267 1268 static bool l2cap_check_efs(struct l2cap_chan *chan) 1269 { 1270 /* Check EFS parameters */ 1271 return true; 1272 } 1273 1274 void l2cap_send_conn_req(struct l2cap_chan *chan) 1275 { 1276 struct l2cap_conn *conn = chan->conn; 1277 struct l2cap_conn_req req; 1278 1279 req.scid = cpu_to_le16(chan->scid); 1280 req.psm = chan->psm; 1281 1282 chan->ident = l2cap_get_ident(conn); 1283 1284 set_bit(CONF_CONNECT_PEND, &chan->conf_state); 1285 1286 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_REQ, sizeof(req), &req); 1287 } 1288 1289 static void l2cap_send_create_chan_req(struct l2cap_chan *chan, u8 amp_id) 1290 { 1291 struct l2cap_create_chan_req req; 1292 req.scid = cpu_to_le16(chan->scid); 1293 req.psm = chan->psm; 1294 req.amp_id = amp_id; 1295 1296 chan->ident = l2cap_get_ident(chan->conn); 1297 1298 l2cap_send_cmd(chan->conn, chan->ident, L2CAP_CREATE_CHAN_REQ, 1299 sizeof(req), &req); 1300 } 1301 1302 static void l2cap_move_setup(struct l2cap_chan *chan) 1303 { 1304 struct sk_buff *skb; 1305 1306 BT_DBG("chan %p", chan); 1307 1308 if (chan->mode != L2CAP_MODE_ERTM) 1309 return; 1310 1311 __clear_retrans_timer(chan); 1312 __clear_monitor_timer(chan); 1313 __clear_ack_timer(chan); 1314 1315 chan->retry_count = 0; 1316 skb_queue_walk(&chan->tx_q, skb) { 1317 if (bt_cb(skb)->l2cap.retries) 1318 bt_cb(skb)->l2cap.retries = 1; 1319 else 1320 break; 1321 } 1322 1323 chan->expected_tx_seq = chan->buffer_seq; 1324 1325 clear_bit(CONN_REJ_ACT, &chan->conn_state); 1326 clear_bit(CONN_SREJ_ACT, &chan->conn_state); 1327 l2cap_seq_list_clear(&chan->retrans_list); 1328 l2cap_seq_list_clear(&chan->srej_list); 1329 skb_queue_purge(&chan->srej_q); 1330 1331 chan->tx_state = L2CAP_TX_STATE_XMIT; 1332 chan->rx_state = L2CAP_RX_STATE_MOVE; 1333 1334 set_bit(CONN_REMOTE_BUSY, &chan->conn_state); 1335 } 1336 1337 static void l2cap_move_done(struct l2cap_chan *chan) 1338 { 1339 u8 move_role = chan->move_role; 1340 BT_DBG("chan %p", chan); 1341 1342 chan->move_state = L2CAP_MOVE_STABLE; 1343 chan->move_role = L2CAP_MOVE_ROLE_NONE; 1344 1345 if (chan->mode != L2CAP_MODE_ERTM) 1346 return; 1347 1348 switch (move_role) { 1349 case L2CAP_MOVE_ROLE_INITIATOR: 1350 l2cap_tx(chan, NULL, NULL, L2CAP_EV_EXPLICIT_POLL); 1351 chan->rx_state = L2CAP_RX_STATE_WAIT_F; 1352 break; 1353 case L2CAP_MOVE_ROLE_RESPONDER: 1354 chan->rx_state = L2CAP_RX_STATE_WAIT_P; 1355 break; 1356 } 1357 } 1358 1359 static void l2cap_chan_ready(struct l2cap_chan *chan) 1360 { 1361 /* The channel may have already been flagged as connected in 1362 * case of receiving data before the L2CAP info req/rsp 1363 * procedure is complete. 1364 */ 1365 if (chan->state == BT_CONNECTED) 1366 return; 1367 1368 /* This clears all conf flags, including CONF_NOT_COMPLETE */ 1369 chan->conf_state = 0; 1370 __clear_chan_timer(chan); 1371 1372 switch (chan->mode) { 1373 case L2CAP_MODE_LE_FLOWCTL: 1374 case L2CAP_MODE_EXT_FLOWCTL: 1375 if (!chan->tx_credits) 1376 chan->ops->suspend(chan); 1377 break; 1378 } 1379 1380 chan->state = BT_CONNECTED; 1381 1382 chan->ops->ready(chan); 1383 } 1384 1385 static void l2cap_le_connect(struct l2cap_chan *chan) 1386 { 1387 struct l2cap_conn *conn = chan->conn; 1388 struct l2cap_le_conn_req req; 1389 1390 if (test_and_set_bit(FLAG_LE_CONN_REQ_SENT, &chan->flags)) 1391 return; 1392 1393 if (!chan->imtu) 1394 chan->imtu = chan->conn->mtu; 1395 1396 l2cap_le_flowctl_init(chan, 0); 1397 1398 memset(&req, 0, sizeof(req)); 1399 req.psm = chan->psm; 1400 req.scid = cpu_to_le16(chan->scid); 1401 req.mtu = cpu_to_le16(chan->imtu); 1402 req.mps = cpu_to_le16(chan->mps); 1403 req.credits = cpu_to_le16(chan->rx_credits); 1404 1405 chan->ident = l2cap_get_ident(conn); 1406 1407 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_REQ, 1408 sizeof(req), &req); 1409 } 1410 1411 struct l2cap_ecred_conn_data { 1412 struct { 1413 struct l2cap_ecred_conn_req req; 1414 __le16 scid[5]; 1415 } __packed pdu; 1416 struct l2cap_chan *chan; 1417 struct pid *pid; 1418 int count; 1419 }; 1420 1421 static void l2cap_ecred_defer_connect(struct l2cap_chan *chan, void *data) 1422 { 1423 struct l2cap_ecred_conn_data *conn = data; 1424 struct pid *pid; 1425 1426 if (chan == conn->chan) 1427 return; 1428 1429 if (!test_and_clear_bit(FLAG_DEFER_SETUP, &chan->flags)) 1430 return; 1431 1432 pid = chan->ops->get_peer_pid(chan); 1433 1434 /* Only add deferred channels with the same PID/PSM */ 1435 if (conn->pid != pid || chan->psm != conn->chan->psm || chan->ident || 1436 chan->mode != L2CAP_MODE_EXT_FLOWCTL || chan->state != BT_CONNECT) 1437 return; 1438 1439 if (test_and_set_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags)) 1440 return; 1441 1442 l2cap_ecred_init(chan, 0); 1443 1444 /* Set the same ident so we can match on the rsp */ 1445 chan->ident = conn->chan->ident; 1446 1447 /* Include all channels deferred */ 1448 conn->pdu.scid[conn->count] = cpu_to_le16(chan->scid); 1449 1450 conn->count++; 1451 } 1452 1453 static void l2cap_ecred_connect(struct l2cap_chan *chan) 1454 { 1455 struct l2cap_conn *conn = chan->conn; 1456 struct l2cap_ecred_conn_data data; 1457 1458 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) 1459 return; 1460 1461 if (test_and_set_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags)) 1462 return; 1463 1464 l2cap_ecred_init(chan, 0); 1465 1466 memset(&data, 0, sizeof(data)); 1467 data.pdu.req.psm = chan->psm; 1468 data.pdu.req.mtu = cpu_to_le16(chan->imtu); 1469 data.pdu.req.mps = cpu_to_le16(chan->mps); 1470 data.pdu.req.credits = cpu_to_le16(chan->rx_credits); 1471 data.pdu.scid[0] = cpu_to_le16(chan->scid); 1472 1473 chan->ident = l2cap_get_ident(conn); 1474 1475 data.count = 1; 1476 data.chan = chan; 1477 data.pid = chan->ops->get_peer_pid(chan); 1478 1479 __l2cap_chan_list(conn, l2cap_ecred_defer_connect, &data); 1480 1481 l2cap_send_cmd(conn, chan->ident, L2CAP_ECRED_CONN_REQ, 1482 sizeof(data.pdu.req) + data.count * sizeof(__le16), 1483 &data.pdu); 1484 } 1485 1486 static void l2cap_le_start(struct l2cap_chan *chan) 1487 { 1488 struct l2cap_conn *conn = chan->conn; 1489 1490 if (!smp_conn_security(conn->hcon, chan->sec_level)) 1491 return; 1492 1493 if (!chan->psm) { 1494 l2cap_chan_ready(chan); 1495 return; 1496 } 1497 1498 if (chan->state == BT_CONNECT) { 1499 if (chan->mode == L2CAP_MODE_EXT_FLOWCTL) 1500 l2cap_ecred_connect(chan); 1501 else 1502 l2cap_le_connect(chan); 1503 } 1504 } 1505 1506 static void l2cap_start_connection(struct l2cap_chan *chan) 1507 { 1508 if (__amp_capable(chan)) { 1509 BT_DBG("chan %p AMP capable: discover AMPs", chan); 1510 a2mp_discover_amp(chan); 1511 } else if (chan->conn->hcon->type == LE_LINK) { 1512 l2cap_le_start(chan); 1513 } else { 1514 l2cap_send_conn_req(chan); 1515 } 1516 } 1517 1518 static void l2cap_request_info(struct l2cap_conn *conn) 1519 { 1520 struct l2cap_info_req req; 1521 1522 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT) 1523 return; 1524 1525 req.type = cpu_to_le16(L2CAP_IT_FEAT_MASK); 1526 1527 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_SENT; 1528 conn->info_ident = l2cap_get_ident(conn); 1529 1530 schedule_delayed_work(&conn->info_timer, L2CAP_INFO_TIMEOUT); 1531 1532 l2cap_send_cmd(conn, conn->info_ident, L2CAP_INFO_REQ, 1533 sizeof(req), &req); 1534 } 1535 1536 static bool l2cap_check_enc_key_size(struct hci_conn *hcon) 1537 { 1538 /* The minimum encryption key size needs to be enforced by the 1539 * host stack before establishing any L2CAP connections. The 1540 * specification in theory allows a minimum of 1, but to align 1541 * BR/EDR and LE transports, a minimum of 7 is chosen. 1542 * 1543 * This check might also be called for unencrypted connections 1544 * that have no key size requirements. Ensure that the link is 1545 * actually encrypted before enforcing a key size. 1546 */ 1547 int min_key_size = hcon->hdev->min_enc_key_size; 1548 1549 /* On FIPS security level, key size must be 16 bytes */ 1550 if (hcon->sec_level == BT_SECURITY_FIPS) 1551 min_key_size = 16; 1552 1553 return (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags) || 1554 hcon->enc_key_size >= min_key_size); 1555 } 1556 1557 static void l2cap_do_start(struct l2cap_chan *chan) 1558 { 1559 struct l2cap_conn *conn = chan->conn; 1560 1561 if (conn->hcon->type == LE_LINK) { 1562 l2cap_le_start(chan); 1563 return; 1564 } 1565 1566 if (!(conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT)) { 1567 l2cap_request_info(conn); 1568 return; 1569 } 1570 1571 if (!(conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE)) 1572 return; 1573 1574 if (!l2cap_chan_check_security(chan, true) || 1575 !__l2cap_no_conn_pending(chan)) 1576 return; 1577 1578 if (l2cap_check_enc_key_size(conn->hcon)) 1579 l2cap_start_connection(chan); 1580 else 1581 __set_chan_timer(chan, L2CAP_DISC_TIMEOUT); 1582 } 1583 1584 static inline int l2cap_mode_supported(__u8 mode, __u32 feat_mask) 1585 { 1586 u32 local_feat_mask = l2cap_feat_mask; 1587 if (!disable_ertm) 1588 local_feat_mask |= L2CAP_FEAT_ERTM | L2CAP_FEAT_STREAMING; 1589 1590 switch (mode) { 1591 case L2CAP_MODE_ERTM: 1592 return L2CAP_FEAT_ERTM & feat_mask & local_feat_mask; 1593 case L2CAP_MODE_STREAMING: 1594 return L2CAP_FEAT_STREAMING & feat_mask & local_feat_mask; 1595 default: 1596 return 0x00; 1597 } 1598 } 1599 1600 static void l2cap_send_disconn_req(struct l2cap_chan *chan, int err) 1601 { 1602 struct l2cap_conn *conn = chan->conn; 1603 struct l2cap_disconn_req req; 1604 1605 if (!conn) 1606 return; 1607 1608 if (chan->mode == L2CAP_MODE_ERTM && chan->state == BT_CONNECTED) { 1609 __clear_retrans_timer(chan); 1610 __clear_monitor_timer(chan); 1611 __clear_ack_timer(chan); 1612 } 1613 1614 if (chan->scid == L2CAP_CID_A2MP) { 1615 l2cap_state_change(chan, BT_DISCONN); 1616 return; 1617 } 1618 1619 req.dcid = cpu_to_le16(chan->dcid); 1620 req.scid = cpu_to_le16(chan->scid); 1621 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_DISCONN_REQ, 1622 sizeof(req), &req); 1623 1624 l2cap_state_change_and_error(chan, BT_DISCONN, err); 1625 } 1626 1627 /* ---- L2CAP connections ---- */ 1628 static void l2cap_conn_start(struct l2cap_conn *conn) 1629 { 1630 struct l2cap_chan *chan, *tmp; 1631 1632 BT_DBG("conn %p", conn); 1633 1634 mutex_lock(&conn->chan_lock); 1635 1636 list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) { 1637 l2cap_chan_lock(chan); 1638 1639 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) { 1640 l2cap_chan_ready(chan); 1641 l2cap_chan_unlock(chan); 1642 continue; 1643 } 1644 1645 if (chan->state == BT_CONNECT) { 1646 if (!l2cap_chan_check_security(chan, true) || 1647 !__l2cap_no_conn_pending(chan)) { 1648 l2cap_chan_unlock(chan); 1649 continue; 1650 } 1651 1652 if (!l2cap_mode_supported(chan->mode, conn->feat_mask) 1653 && test_bit(CONF_STATE2_DEVICE, 1654 &chan->conf_state)) { 1655 l2cap_chan_close(chan, ECONNRESET); 1656 l2cap_chan_unlock(chan); 1657 continue; 1658 } 1659 1660 if (l2cap_check_enc_key_size(conn->hcon)) 1661 l2cap_start_connection(chan); 1662 else 1663 l2cap_chan_close(chan, ECONNREFUSED); 1664 1665 } else if (chan->state == BT_CONNECT2) { 1666 struct l2cap_conn_rsp rsp; 1667 char buf[128]; 1668 rsp.scid = cpu_to_le16(chan->dcid); 1669 rsp.dcid = cpu_to_le16(chan->scid); 1670 1671 if (l2cap_chan_check_security(chan, false)) { 1672 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) { 1673 rsp.result = cpu_to_le16(L2CAP_CR_PEND); 1674 rsp.status = cpu_to_le16(L2CAP_CS_AUTHOR_PEND); 1675 chan->ops->defer(chan); 1676 1677 } else { 1678 l2cap_state_change(chan, BT_CONFIG); 1679 rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS); 1680 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO); 1681 } 1682 } else { 1683 rsp.result = cpu_to_le16(L2CAP_CR_PEND); 1684 rsp.status = cpu_to_le16(L2CAP_CS_AUTHEN_PEND); 1685 } 1686 1687 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP, 1688 sizeof(rsp), &rsp); 1689 1690 if (test_bit(CONF_REQ_SENT, &chan->conf_state) || 1691 rsp.result != L2CAP_CR_SUCCESS) { 1692 l2cap_chan_unlock(chan); 1693 continue; 1694 } 1695 1696 set_bit(CONF_REQ_SENT, &chan->conf_state); 1697 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ, 1698 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf); 1699 chan->num_conf_req++; 1700 } 1701 1702 l2cap_chan_unlock(chan); 1703 } 1704 1705 mutex_unlock(&conn->chan_lock); 1706 } 1707 1708 static void l2cap_le_conn_ready(struct l2cap_conn *conn) 1709 { 1710 struct hci_conn *hcon = conn->hcon; 1711 struct hci_dev *hdev = hcon->hdev; 1712 1713 BT_DBG("%s conn %p", hdev->name, conn); 1714 1715 /* For outgoing pairing which doesn't necessarily have an 1716 * associated socket (e.g. mgmt_pair_device). 1717 */ 1718 if (hcon->out) 1719 smp_conn_security(hcon, hcon->pending_sec_level); 1720 1721 /* For LE peripheral connections, make sure the connection interval 1722 * is in the range of the minimum and maximum interval that has 1723 * been configured for this connection. If not, then trigger 1724 * the connection update procedure. 1725 */ 1726 if (hcon->role == HCI_ROLE_SLAVE && 1727 (hcon->le_conn_interval < hcon->le_conn_min_interval || 1728 hcon->le_conn_interval > hcon->le_conn_max_interval)) { 1729 struct l2cap_conn_param_update_req req; 1730 1731 req.min = cpu_to_le16(hcon->le_conn_min_interval); 1732 req.max = cpu_to_le16(hcon->le_conn_max_interval); 1733 req.latency = cpu_to_le16(hcon->le_conn_latency); 1734 req.to_multiplier = cpu_to_le16(hcon->le_supv_timeout); 1735 1736 l2cap_send_cmd(conn, l2cap_get_ident(conn), 1737 L2CAP_CONN_PARAM_UPDATE_REQ, sizeof(req), &req); 1738 } 1739 } 1740 1741 static void l2cap_conn_ready(struct l2cap_conn *conn) 1742 { 1743 struct l2cap_chan *chan; 1744 struct hci_conn *hcon = conn->hcon; 1745 1746 BT_DBG("conn %p", conn); 1747 1748 if (hcon->type == ACL_LINK) 1749 l2cap_request_info(conn); 1750 1751 mutex_lock(&conn->chan_lock); 1752 1753 list_for_each_entry(chan, &conn->chan_l, list) { 1754 1755 l2cap_chan_lock(chan); 1756 1757 if (chan->scid == L2CAP_CID_A2MP) { 1758 l2cap_chan_unlock(chan); 1759 continue; 1760 } 1761 1762 if (hcon->type == LE_LINK) { 1763 l2cap_le_start(chan); 1764 } else if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) { 1765 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE) 1766 l2cap_chan_ready(chan); 1767 } else if (chan->state == BT_CONNECT) { 1768 l2cap_do_start(chan); 1769 } 1770 1771 l2cap_chan_unlock(chan); 1772 } 1773 1774 mutex_unlock(&conn->chan_lock); 1775 1776 if (hcon->type == LE_LINK) 1777 l2cap_le_conn_ready(conn); 1778 1779 queue_work(hcon->hdev->workqueue, &conn->pending_rx_work); 1780 } 1781 1782 /* Notify sockets that we cannot guaranty reliability anymore */ 1783 static void l2cap_conn_unreliable(struct l2cap_conn *conn, int err) 1784 { 1785 struct l2cap_chan *chan; 1786 1787 BT_DBG("conn %p", conn); 1788 1789 mutex_lock(&conn->chan_lock); 1790 1791 list_for_each_entry(chan, &conn->chan_l, list) { 1792 if (test_bit(FLAG_FORCE_RELIABLE, &chan->flags)) 1793 l2cap_chan_set_err(chan, err); 1794 } 1795 1796 mutex_unlock(&conn->chan_lock); 1797 } 1798 1799 static void l2cap_info_timeout(struct work_struct *work) 1800 { 1801 struct l2cap_conn *conn = container_of(work, struct l2cap_conn, 1802 info_timer.work); 1803 1804 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE; 1805 conn->info_ident = 0; 1806 1807 l2cap_conn_start(conn); 1808 } 1809 1810 /* 1811 * l2cap_user 1812 * External modules can register l2cap_user objects on l2cap_conn. The ->probe 1813 * callback is called during registration. The ->remove callback is called 1814 * during unregistration. 1815 * An l2cap_user object can either be explicitly unregistered or when the 1816 * underlying l2cap_conn object is deleted. This guarantees that l2cap->hcon, 1817 * l2cap->hchan, .. are valid as long as the remove callback hasn't been called. 1818 * External modules must own a reference to the l2cap_conn object if they intend 1819 * to call l2cap_unregister_user(). The l2cap_conn object might get destroyed at 1820 * any time if they don't. 1821 */ 1822 1823 int l2cap_register_user(struct l2cap_conn *conn, struct l2cap_user *user) 1824 { 1825 struct hci_dev *hdev = conn->hcon->hdev; 1826 int ret; 1827 1828 /* We need to check whether l2cap_conn is registered. If it is not, we 1829 * must not register the l2cap_user. l2cap_conn_del() is unregisters 1830 * l2cap_conn objects, but doesn't provide its own locking. Instead, it 1831 * relies on the parent hci_conn object to be locked. This itself relies 1832 * on the hci_dev object to be locked. So we must lock the hci device 1833 * here, too. */ 1834 1835 hci_dev_lock(hdev); 1836 1837 if (!list_empty(&user->list)) { 1838 ret = -EINVAL; 1839 goto out_unlock; 1840 } 1841 1842 /* conn->hchan is NULL after l2cap_conn_del() was called */ 1843 if (!conn->hchan) { 1844 ret = -ENODEV; 1845 goto out_unlock; 1846 } 1847 1848 ret = user->probe(conn, user); 1849 if (ret) 1850 goto out_unlock; 1851 1852 list_add(&user->list, &conn->users); 1853 ret = 0; 1854 1855 out_unlock: 1856 hci_dev_unlock(hdev); 1857 return ret; 1858 } 1859 EXPORT_SYMBOL(l2cap_register_user); 1860 1861 void l2cap_unregister_user(struct l2cap_conn *conn, struct l2cap_user *user) 1862 { 1863 struct hci_dev *hdev = conn->hcon->hdev; 1864 1865 hci_dev_lock(hdev); 1866 1867 if (list_empty(&user->list)) 1868 goto out_unlock; 1869 1870 list_del_init(&user->list); 1871 user->remove(conn, user); 1872 1873 out_unlock: 1874 hci_dev_unlock(hdev); 1875 } 1876 EXPORT_SYMBOL(l2cap_unregister_user); 1877 1878 static void l2cap_unregister_all_users(struct l2cap_conn *conn) 1879 { 1880 struct l2cap_user *user; 1881 1882 while (!list_empty(&conn->users)) { 1883 user = list_first_entry(&conn->users, struct l2cap_user, list); 1884 list_del_init(&user->list); 1885 user->remove(conn, user); 1886 } 1887 } 1888 1889 static void l2cap_conn_del(struct hci_conn *hcon, int err) 1890 { 1891 struct l2cap_conn *conn = hcon->l2cap_data; 1892 struct l2cap_chan *chan, *l; 1893 1894 if (!conn) 1895 return; 1896 1897 BT_DBG("hcon %p conn %p, err %d", hcon, conn, err); 1898 1899 kfree_skb(conn->rx_skb); 1900 1901 skb_queue_purge(&conn->pending_rx); 1902 1903 /* We can not call flush_work(&conn->pending_rx_work) here since we 1904 * might block if we are running on a worker from the same workqueue 1905 * pending_rx_work is waiting on. 1906 */ 1907 if (work_pending(&conn->pending_rx_work)) 1908 cancel_work_sync(&conn->pending_rx_work); 1909 1910 cancel_delayed_work_sync(&conn->id_addr_timer); 1911 1912 l2cap_unregister_all_users(conn); 1913 1914 /* Force the connection to be immediately dropped */ 1915 hcon->disc_timeout = 0; 1916 1917 mutex_lock(&conn->chan_lock); 1918 1919 /* Kill channels */ 1920 list_for_each_entry_safe(chan, l, &conn->chan_l, list) { 1921 l2cap_chan_hold(chan); 1922 l2cap_chan_lock(chan); 1923 1924 l2cap_chan_del(chan, err); 1925 1926 chan->ops->close(chan); 1927 1928 l2cap_chan_unlock(chan); 1929 l2cap_chan_put(chan); 1930 } 1931 1932 mutex_unlock(&conn->chan_lock); 1933 1934 hci_chan_del(conn->hchan); 1935 1936 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT) 1937 cancel_delayed_work_sync(&conn->info_timer); 1938 1939 hcon->l2cap_data = NULL; 1940 conn->hchan = NULL; 1941 l2cap_conn_put(conn); 1942 } 1943 1944 static void l2cap_conn_free(struct kref *ref) 1945 { 1946 struct l2cap_conn *conn = container_of(ref, struct l2cap_conn, ref); 1947 1948 hci_conn_put(conn->hcon); 1949 kfree(conn); 1950 } 1951 1952 struct l2cap_conn *l2cap_conn_get(struct l2cap_conn *conn) 1953 { 1954 kref_get(&conn->ref); 1955 return conn; 1956 } 1957 EXPORT_SYMBOL(l2cap_conn_get); 1958 1959 void l2cap_conn_put(struct l2cap_conn *conn) 1960 { 1961 kref_put(&conn->ref, l2cap_conn_free); 1962 } 1963 EXPORT_SYMBOL(l2cap_conn_put); 1964 1965 /* ---- Socket interface ---- */ 1966 1967 /* Find socket with psm and source / destination bdaddr. 1968 * Returns closest match. 1969 */ 1970 static struct l2cap_chan *l2cap_global_chan_by_psm(int state, __le16 psm, 1971 bdaddr_t *src, 1972 bdaddr_t *dst, 1973 u8 link_type) 1974 { 1975 struct l2cap_chan *c, *tmp, *c1 = NULL; 1976 1977 read_lock(&chan_list_lock); 1978 1979 list_for_each_entry_safe(c, tmp, &chan_list, global_l) { 1980 if (state && c->state != state) 1981 continue; 1982 1983 if (link_type == ACL_LINK && c->src_type != BDADDR_BREDR) 1984 continue; 1985 1986 if (link_type == LE_LINK && c->src_type == BDADDR_BREDR) 1987 continue; 1988 1989 if (c->chan_type != L2CAP_CHAN_FIXED && c->psm == psm) { 1990 int src_match, dst_match; 1991 int src_any, dst_any; 1992 1993 /* Exact match. */ 1994 src_match = !bacmp(&c->src, src); 1995 dst_match = !bacmp(&c->dst, dst); 1996 if (src_match && dst_match) { 1997 if (!l2cap_chan_hold_unless_zero(c)) 1998 continue; 1999 2000 read_unlock(&chan_list_lock); 2001 return c; 2002 } 2003 2004 /* Closest match */ 2005 src_any = !bacmp(&c->src, BDADDR_ANY); 2006 dst_any = !bacmp(&c->dst, BDADDR_ANY); 2007 if ((src_match && dst_any) || (src_any && dst_match) || 2008 (src_any && dst_any)) 2009 c1 = c; 2010 } 2011 } 2012 2013 if (c1) 2014 c1 = l2cap_chan_hold_unless_zero(c1); 2015 2016 read_unlock(&chan_list_lock); 2017 2018 return c1; 2019 } 2020 2021 static void l2cap_monitor_timeout(struct work_struct *work) 2022 { 2023 struct l2cap_chan *chan = container_of(work, struct l2cap_chan, 2024 monitor_timer.work); 2025 2026 BT_DBG("chan %p", chan); 2027 2028 l2cap_chan_lock(chan); 2029 2030 if (!chan->conn) { 2031 l2cap_chan_unlock(chan); 2032 l2cap_chan_put(chan); 2033 return; 2034 } 2035 2036 l2cap_tx(chan, NULL, NULL, L2CAP_EV_MONITOR_TO); 2037 2038 l2cap_chan_unlock(chan); 2039 l2cap_chan_put(chan); 2040 } 2041 2042 static void l2cap_retrans_timeout(struct work_struct *work) 2043 { 2044 struct l2cap_chan *chan = container_of(work, struct l2cap_chan, 2045 retrans_timer.work); 2046 2047 BT_DBG("chan %p", chan); 2048 2049 l2cap_chan_lock(chan); 2050 2051 if (!chan->conn) { 2052 l2cap_chan_unlock(chan); 2053 l2cap_chan_put(chan); 2054 return; 2055 } 2056 2057 l2cap_tx(chan, NULL, NULL, L2CAP_EV_RETRANS_TO); 2058 l2cap_chan_unlock(chan); 2059 l2cap_chan_put(chan); 2060 } 2061 2062 static void l2cap_streaming_send(struct l2cap_chan *chan, 2063 struct sk_buff_head *skbs) 2064 { 2065 struct sk_buff *skb; 2066 struct l2cap_ctrl *control; 2067 2068 BT_DBG("chan %p, skbs %p", chan, skbs); 2069 2070 if (__chan_is_moving(chan)) 2071 return; 2072 2073 skb_queue_splice_tail_init(skbs, &chan->tx_q); 2074 2075 while (!skb_queue_empty(&chan->tx_q)) { 2076 2077 skb = skb_dequeue(&chan->tx_q); 2078 2079 bt_cb(skb)->l2cap.retries = 1; 2080 control = &bt_cb(skb)->l2cap; 2081 2082 control->reqseq = 0; 2083 control->txseq = chan->next_tx_seq; 2084 2085 __pack_control(chan, control, skb); 2086 2087 if (chan->fcs == L2CAP_FCS_CRC16) { 2088 u16 fcs = crc16(0, (u8 *) skb->data, skb->len); 2089 put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE)); 2090 } 2091 2092 l2cap_do_send(chan, skb); 2093 2094 BT_DBG("Sent txseq %u", control->txseq); 2095 2096 chan->next_tx_seq = __next_seq(chan, chan->next_tx_seq); 2097 chan->frames_sent++; 2098 } 2099 } 2100 2101 static int l2cap_ertm_send(struct l2cap_chan *chan) 2102 { 2103 struct sk_buff *skb, *tx_skb; 2104 struct l2cap_ctrl *control; 2105 int sent = 0; 2106 2107 BT_DBG("chan %p", chan); 2108 2109 if (chan->state != BT_CONNECTED) 2110 return -ENOTCONN; 2111 2112 if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state)) 2113 return 0; 2114 2115 if (__chan_is_moving(chan)) 2116 return 0; 2117 2118 while (chan->tx_send_head && 2119 chan->unacked_frames < chan->remote_tx_win && 2120 chan->tx_state == L2CAP_TX_STATE_XMIT) { 2121 2122 skb = chan->tx_send_head; 2123 2124 bt_cb(skb)->l2cap.retries = 1; 2125 control = &bt_cb(skb)->l2cap; 2126 2127 if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state)) 2128 control->final = 1; 2129 2130 control->reqseq = chan->buffer_seq; 2131 chan->last_acked_seq = chan->buffer_seq; 2132 control->txseq = chan->next_tx_seq; 2133 2134 __pack_control(chan, control, skb); 2135 2136 if (chan->fcs == L2CAP_FCS_CRC16) { 2137 u16 fcs = crc16(0, (u8 *) skb->data, skb->len); 2138 put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE)); 2139 } 2140 2141 /* Clone after data has been modified. Data is assumed to be 2142 read-only (for locking purposes) on cloned sk_buffs. 2143 */ 2144 tx_skb = skb_clone(skb, GFP_KERNEL); 2145 2146 if (!tx_skb) 2147 break; 2148 2149 __set_retrans_timer(chan); 2150 2151 chan->next_tx_seq = __next_seq(chan, chan->next_tx_seq); 2152 chan->unacked_frames++; 2153 chan->frames_sent++; 2154 sent++; 2155 2156 if (skb_queue_is_last(&chan->tx_q, skb)) 2157 chan->tx_send_head = NULL; 2158 else 2159 chan->tx_send_head = skb_queue_next(&chan->tx_q, skb); 2160 2161 l2cap_do_send(chan, tx_skb); 2162 BT_DBG("Sent txseq %u", control->txseq); 2163 } 2164 2165 BT_DBG("Sent %d, %u unacked, %u in ERTM queue", sent, 2166 chan->unacked_frames, skb_queue_len(&chan->tx_q)); 2167 2168 return sent; 2169 } 2170 2171 static void l2cap_ertm_resend(struct l2cap_chan *chan) 2172 { 2173 struct l2cap_ctrl control; 2174 struct sk_buff *skb; 2175 struct sk_buff *tx_skb; 2176 u16 seq; 2177 2178 BT_DBG("chan %p", chan); 2179 2180 if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state)) 2181 return; 2182 2183 if (__chan_is_moving(chan)) 2184 return; 2185 2186 while (chan->retrans_list.head != L2CAP_SEQ_LIST_CLEAR) { 2187 seq = l2cap_seq_list_pop(&chan->retrans_list); 2188 2189 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, seq); 2190 if (!skb) { 2191 BT_DBG("Error: Can't retransmit seq %d, frame missing", 2192 seq); 2193 continue; 2194 } 2195 2196 bt_cb(skb)->l2cap.retries++; 2197 control = bt_cb(skb)->l2cap; 2198 2199 if (chan->max_tx != 0 && 2200 bt_cb(skb)->l2cap.retries > chan->max_tx) { 2201 BT_DBG("Retry limit exceeded (%d)", chan->max_tx); 2202 l2cap_send_disconn_req(chan, ECONNRESET); 2203 l2cap_seq_list_clear(&chan->retrans_list); 2204 break; 2205 } 2206 2207 control.reqseq = chan->buffer_seq; 2208 if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state)) 2209 control.final = 1; 2210 else 2211 control.final = 0; 2212 2213 if (skb_cloned(skb)) { 2214 /* Cloned sk_buffs are read-only, so we need a 2215 * writeable copy 2216 */ 2217 tx_skb = skb_copy(skb, GFP_KERNEL); 2218 } else { 2219 tx_skb = skb_clone(skb, GFP_KERNEL); 2220 } 2221 2222 if (!tx_skb) { 2223 l2cap_seq_list_clear(&chan->retrans_list); 2224 break; 2225 } 2226 2227 /* Update skb contents */ 2228 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) { 2229 put_unaligned_le32(__pack_extended_control(&control), 2230 tx_skb->data + L2CAP_HDR_SIZE); 2231 } else { 2232 put_unaligned_le16(__pack_enhanced_control(&control), 2233 tx_skb->data + L2CAP_HDR_SIZE); 2234 } 2235 2236 /* Update FCS */ 2237 if (chan->fcs == L2CAP_FCS_CRC16) { 2238 u16 fcs = crc16(0, (u8 *) tx_skb->data, 2239 tx_skb->len - L2CAP_FCS_SIZE); 2240 put_unaligned_le16(fcs, skb_tail_pointer(tx_skb) - 2241 L2CAP_FCS_SIZE); 2242 } 2243 2244 l2cap_do_send(chan, tx_skb); 2245 2246 BT_DBG("Resent txseq %d", control.txseq); 2247 2248 chan->last_acked_seq = chan->buffer_seq; 2249 } 2250 } 2251 2252 static void l2cap_retransmit(struct l2cap_chan *chan, 2253 struct l2cap_ctrl *control) 2254 { 2255 BT_DBG("chan %p, control %p", chan, control); 2256 2257 l2cap_seq_list_append(&chan->retrans_list, control->reqseq); 2258 l2cap_ertm_resend(chan); 2259 } 2260 2261 static void l2cap_retransmit_all(struct l2cap_chan *chan, 2262 struct l2cap_ctrl *control) 2263 { 2264 struct sk_buff *skb; 2265 2266 BT_DBG("chan %p, control %p", chan, control); 2267 2268 if (control->poll) 2269 set_bit(CONN_SEND_FBIT, &chan->conn_state); 2270 2271 l2cap_seq_list_clear(&chan->retrans_list); 2272 2273 if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state)) 2274 return; 2275 2276 if (chan->unacked_frames) { 2277 skb_queue_walk(&chan->tx_q, skb) { 2278 if (bt_cb(skb)->l2cap.txseq == control->reqseq || 2279 skb == chan->tx_send_head) 2280 break; 2281 } 2282 2283 skb_queue_walk_from(&chan->tx_q, skb) { 2284 if (skb == chan->tx_send_head) 2285 break; 2286 2287 l2cap_seq_list_append(&chan->retrans_list, 2288 bt_cb(skb)->l2cap.txseq); 2289 } 2290 2291 l2cap_ertm_resend(chan); 2292 } 2293 } 2294 2295 static void l2cap_send_ack(struct l2cap_chan *chan) 2296 { 2297 struct l2cap_ctrl control; 2298 u16 frames_to_ack = __seq_offset(chan, chan->buffer_seq, 2299 chan->last_acked_seq); 2300 int threshold; 2301 2302 BT_DBG("chan %p last_acked_seq %d buffer_seq %d", 2303 chan, chan->last_acked_seq, chan->buffer_seq); 2304 2305 memset(&control, 0, sizeof(control)); 2306 control.sframe = 1; 2307 2308 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state) && 2309 chan->rx_state == L2CAP_RX_STATE_RECV) { 2310 __clear_ack_timer(chan); 2311 control.super = L2CAP_SUPER_RNR; 2312 control.reqseq = chan->buffer_seq; 2313 l2cap_send_sframe(chan, &control); 2314 } else { 2315 if (!test_bit(CONN_REMOTE_BUSY, &chan->conn_state)) { 2316 l2cap_ertm_send(chan); 2317 /* If any i-frames were sent, they included an ack */ 2318 if (chan->buffer_seq == chan->last_acked_seq) 2319 frames_to_ack = 0; 2320 } 2321 2322 /* Ack now if the window is 3/4ths full. 2323 * Calculate without mul or div 2324 */ 2325 threshold = chan->ack_win; 2326 threshold += threshold << 1; 2327 threshold >>= 2; 2328 2329 BT_DBG("frames_to_ack %u, threshold %d", frames_to_ack, 2330 threshold); 2331 2332 if (frames_to_ack >= threshold) { 2333 __clear_ack_timer(chan); 2334 control.super = L2CAP_SUPER_RR; 2335 control.reqseq = chan->buffer_seq; 2336 l2cap_send_sframe(chan, &control); 2337 frames_to_ack = 0; 2338 } 2339 2340 if (frames_to_ack) 2341 __set_ack_timer(chan); 2342 } 2343 } 2344 2345 static inline int l2cap_skbuff_fromiovec(struct l2cap_chan *chan, 2346 struct msghdr *msg, int len, 2347 int count, struct sk_buff *skb) 2348 { 2349 struct l2cap_conn *conn = chan->conn; 2350 struct sk_buff **frag; 2351 int sent = 0; 2352 2353 if (!copy_from_iter_full(skb_put(skb, count), count, &msg->msg_iter)) 2354 return -EFAULT; 2355 2356 sent += count; 2357 len -= count; 2358 2359 /* Continuation fragments (no L2CAP header) */ 2360 frag = &skb_shinfo(skb)->frag_list; 2361 while (len) { 2362 struct sk_buff *tmp; 2363 2364 count = min_t(unsigned int, conn->mtu, len); 2365 2366 tmp = chan->ops->alloc_skb(chan, 0, count, 2367 msg->msg_flags & MSG_DONTWAIT); 2368 if (IS_ERR(tmp)) 2369 return PTR_ERR(tmp); 2370 2371 *frag = tmp; 2372 2373 if (!copy_from_iter_full(skb_put(*frag, count), count, 2374 &msg->msg_iter)) 2375 return -EFAULT; 2376 2377 sent += count; 2378 len -= count; 2379 2380 skb->len += (*frag)->len; 2381 skb->data_len += (*frag)->len; 2382 2383 frag = &(*frag)->next; 2384 } 2385 2386 return sent; 2387 } 2388 2389 static struct sk_buff *l2cap_create_connless_pdu(struct l2cap_chan *chan, 2390 struct msghdr *msg, size_t len) 2391 { 2392 struct l2cap_conn *conn = chan->conn; 2393 struct sk_buff *skb; 2394 int err, count, hlen = L2CAP_HDR_SIZE + L2CAP_PSMLEN_SIZE; 2395 struct l2cap_hdr *lh; 2396 2397 BT_DBG("chan %p psm 0x%2.2x len %zu", chan, 2398 __le16_to_cpu(chan->psm), len); 2399 2400 count = min_t(unsigned int, (conn->mtu - hlen), len); 2401 2402 skb = chan->ops->alloc_skb(chan, hlen, count, 2403 msg->msg_flags & MSG_DONTWAIT); 2404 if (IS_ERR(skb)) 2405 return skb; 2406 2407 /* Create L2CAP header */ 2408 lh = skb_put(skb, L2CAP_HDR_SIZE); 2409 lh->cid = cpu_to_le16(chan->dcid); 2410 lh->len = cpu_to_le16(len + L2CAP_PSMLEN_SIZE); 2411 put_unaligned(chan->psm, (__le16 *) skb_put(skb, L2CAP_PSMLEN_SIZE)); 2412 2413 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb); 2414 if (unlikely(err < 0)) { 2415 kfree_skb(skb); 2416 return ERR_PTR(err); 2417 } 2418 return skb; 2419 } 2420 2421 static struct sk_buff *l2cap_create_basic_pdu(struct l2cap_chan *chan, 2422 struct msghdr *msg, size_t len) 2423 { 2424 struct l2cap_conn *conn = chan->conn; 2425 struct sk_buff *skb; 2426 int err, count; 2427 struct l2cap_hdr *lh; 2428 2429 BT_DBG("chan %p len %zu", chan, len); 2430 2431 count = min_t(unsigned int, (conn->mtu - L2CAP_HDR_SIZE), len); 2432 2433 skb = chan->ops->alloc_skb(chan, L2CAP_HDR_SIZE, count, 2434 msg->msg_flags & MSG_DONTWAIT); 2435 if (IS_ERR(skb)) 2436 return skb; 2437 2438 /* Create L2CAP header */ 2439 lh = skb_put(skb, L2CAP_HDR_SIZE); 2440 lh->cid = cpu_to_le16(chan->dcid); 2441 lh->len = cpu_to_le16(len); 2442 2443 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb); 2444 if (unlikely(err < 0)) { 2445 kfree_skb(skb); 2446 return ERR_PTR(err); 2447 } 2448 return skb; 2449 } 2450 2451 static struct sk_buff *l2cap_create_iframe_pdu(struct l2cap_chan *chan, 2452 struct msghdr *msg, size_t len, 2453 u16 sdulen) 2454 { 2455 struct l2cap_conn *conn = chan->conn; 2456 struct sk_buff *skb; 2457 int err, count, hlen; 2458 struct l2cap_hdr *lh; 2459 2460 BT_DBG("chan %p len %zu", chan, len); 2461 2462 if (!conn) 2463 return ERR_PTR(-ENOTCONN); 2464 2465 hlen = __ertm_hdr_size(chan); 2466 2467 if (sdulen) 2468 hlen += L2CAP_SDULEN_SIZE; 2469 2470 if (chan->fcs == L2CAP_FCS_CRC16) 2471 hlen += L2CAP_FCS_SIZE; 2472 2473 count = min_t(unsigned int, (conn->mtu - hlen), len); 2474 2475 skb = chan->ops->alloc_skb(chan, hlen, count, 2476 msg->msg_flags & MSG_DONTWAIT); 2477 if (IS_ERR(skb)) 2478 return skb; 2479 2480 /* Create L2CAP header */ 2481 lh = skb_put(skb, L2CAP_HDR_SIZE); 2482 lh->cid = cpu_to_le16(chan->dcid); 2483 lh->len = cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE)); 2484 2485 /* Control header is populated later */ 2486 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) 2487 put_unaligned_le32(0, skb_put(skb, L2CAP_EXT_CTRL_SIZE)); 2488 else 2489 put_unaligned_le16(0, skb_put(skb, L2CAP_ENH_CTRL_SIZE)); 2490 2491 if (sdulen) 2492 put_unaligned_le16(sdulen, skb_put(skb, L2CAP_SDULEN_SIZE)); 2493 2494 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb); 2495 if (unlikely(err < 0)) { 2496 kfree_skb(skb); 2497 return ERR_PTR(err); 2498 } 2499 2500 bt_cb(skb)->l2cap.fcs = chan->fcs; 2501 bt_cb(skb)->l2cap.retries = 0; 2502 return skb; 2503 } 2504 2505 static int l2cap_segment_sdu(struct l2cap_chan *chan, 2506 struct sk_buff_head *seg_queue, 2507 struct msghdr *msg, size_t len) 2508 { 2509 struct sk_buff *skb; 2510 u16 sdu_len; 2511 size_t pdu_len; 2512 u8 sar; 2513 2514 BT_DBG("chan %p, msg %p, len %zu", chan, msg, len); 2515 2516 /* It is critical that ERTM PDUs fit in a single HCI fragment, 2517 * so fragmented skbs are not used. The HCI layer's handling 2518 * of fragmented skbs is not compatible with ERTM's queueing. 2519 */ 2520 2521 /* PDU size is derived from the HCI MTU */ 2522 pdu_len = chan->conn->mtu; 2523 2524 /* Constrain PDU size for BR/EDR connections */ 2525 if (!chan->hs_hcon) 2526 pdu_len = min_t(size_t, pdu_len, L2CAP_BREDR_MAX_PAYLOAD); 2527 2528 /* Adjust for largest possible L2CAP overhead. */ 2529 if (chan->fcs) 2530 pdu_len -= L2CAP_FCS_SIZE; 2531 2532 pdu_len -= __ertm_hdr_size(chan); 2533 2534 /* Remote device may have requested smaller PDUs */ 2535 pdu_len = min_t(size_t, pdu_len, chan->remote_mps); 2536 2537 if (len <= pdu_len) { 2538 sar = L2CAP_SAR_UNSEGMENTED; 2539 sdu_len = 0; 2540 pdu_len = len; 2541 } else { 2542 sar = L2CAP_SAR_START; 2543 sdu_len = len; 2544 } 2545 2546 while (len > 0) { 2547 skb = l2cap_create_iframe_pdu(chan, msg, pdu_len, sdu_len); 2548 2549 if (IS_ERR(skb)) { 2550 __skb_queue_purge(seg_queue); 2551 return PTR_ERR(skb); 2552 } 2553 2554 bt_cb(skb)->l2cap.sar = sar; 2555 __skb_queue_tail(seg_queue, skb); 2556 2557 len -= pdu_len; 2558 if (sdu_len) 2559 sdu_len = 0; 2560 2561 if (len <= pdu_len) { 2562 sar = L2CAP_SAR_END; 2563 pdu_len = len; 2564 } else { 2565 sar = L2CAP_SAR_CONTINUE; 2566 } 2567 } 2568 2569 return 0; 2570 } 2571 2572 static struct sk_buff *l2cap_create_le_flowctl_pdu(struct l2cap_chan *chan, 2573 struct msghdr *msg, 2574 size_t len, u16 sdulen) 2575 { 2576 struct l2cap_conn *conn = chan->conn; 2577 struct sk_buff *skb; 2578 int err, count, hlen; 2579 struct l2cap_hdr *lh; 2580 2581 BT_DBG("chan %p len %zu", chan, len); 2582 2583 if (!conn) 2584 return ERR_PTR(-ENOTCONN); 2585 2586 hlen = L2CAP_HDR_SIZE; 2587 2588 if (sdulen) 2589 hlen += L2CAP_SDULEN_SIZE; 2590 2591 count = min_t(unsigned int, (conn->mtu - hlen), len); 2592 2593 skb = chan->ops->alloc_skb(chan, hlen, count, 2594 msg->msg_flags & MSG_DONTWAIT); 2595 if (IS_ERR(skb)) 2596 return skb; 2597 2598 /* Create L2CAP header */ 2599 lh = skb_put(skb, L2CAP_HDR_SIZE); 2600 lh->cid = cpu_to_le16(chan->dcid); 2601 lh->len = cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE)); 2602 2603 if (sdulen) 2604 put_unaligned_le16(sdulen, skb_put(skb, L2CAP_SDULEN_SIZE)); 2605 2606 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb); 2607 if (unlikely(err < 0)) { 2608 kfree_skb(skb); 2609 return ERR_PTR(err); 2610 } 2611 2612 return skb; 2613 } 2614 2615 static int l2cap_segment_le_sdu(struct l2cap_chan *chan, 2616 struct sk_buff_head *seg_queue, 2617 struct msghdr *msg, size_t len) 2618 { 2619 struct sk_buff *skb; 2620 size_t pdu_len; 2621 u16 sdu_len; 2622 2623 BT_DBG("chan %p, msg %p, len %zu", chan, msg, len); 2624 2625 sdu_len = len; 2626 pdu_len = chan->remote_mps - L2CAP_SDULEN_SIZE; 2627 2628 while (len > 0) { 2629 if (len <= pdu_len) 2630 pdu_len = len; 2631 2632 skb = l2cap_create_le_flowctl_pdu(chan, msg, pdu_len, sdu_len); 2633 if (IS_ERR(skb)) { 2634 __skb_queue_purge(seg_queue); 2635 return PTR_ERR(skb); 2636 } 2637 2638 __skb_queue_tail(seg_queue, skb); 2639 2640 len -= pdu_len; 2641 2642 if (sdu_len) { 2643 sdu_len = 0; 2644 pdu_len += L2CAP_SDULEN_SIZE; 2645 } 2646 } 2647 2648 return 0; 2649 } 2650 2651 static void l2cap_le_flowctl_send(struct l2cap_chan *chan) 2652 { 2653 int sent = 0; 2654 2655 BT_DBG("chan %p", chan); 2656 2657 while (chan->tx_credits && !skb_queue_empty(&chan->tx_q)) { 2658 l2cap_do_send(chan, skb_dequeue(&chan->tx_q)); 2659 chan->tx_credits--; 2660 sent++; 2661 } 2662 2663 BT_DBG("Sent %d credits %u queued %u", sent, chan->tx_credits, 2664 skb_queue_len(&chan->tx_q)); 2665 } 2666 2667 int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len) 2668 { 2669 struct sk_buff *skb; 2670 int err; 2671 struct sk_buff_head seg_queue; 2672 2673 if (!chan->conn) 2674 return -ENOTCONN; 2675 2676 /* Connectionless channel */ 2677 if (chan->chan_type == L2CAP_CHAN_CONN_LESS) { 2678 skb = l2cap_create_connless_pdu(chan, msg, len); 2679 if (IS_ERR(skb)) 2680 return PTR_ERR(skb); 2681 2682 l2cap_do_send(chan, skb); 2683 return len; 2684 } 2685 2686 switch (chan->mode) { 2687 case L2CAP_MODE_LE_FLOWCTL: 2688 case L2CAP_MODE_EXT_FLOWCTL: 2689 /* Check outgoing MTU */ 2690 if (len > chan->omtu) 2691 return -EMSGSIZE; 2692 2693 __skb_queue_head_init(&seg_queue); 2694 2695 err = l2cap_segment_le_sdu(chan, &seg_queue, msg, len); 2696 2697 if (chan->state != BT_CONNECTED) { 2698 __skb_queue_purge(&seg_queue); 2699 err = -ENOTCONN; 2700 } 2701 2702 if (err) 2703 return err; 2704 2705 skb_queue_splice_tail_init(&seg_queue, &chan->tx_q); 2706 2707 l2cap_le_flowctl_send(chan); 2708 2709 if (!chan->tx_credits) 2710 chan->ops->suspend(chan); 2711 2712 err = len; 2713 2714 break; 2715 2716 case L2CAP_MODE_BASIC: 2717 /* Check outgoing MTU */ 2718 if (len > chan->omtu) 2719 return -EMSGSIZE; 2720 2721 /* Create a basic PDU */ 2722 skb = l2cap_create_basic_pdu(chan, msg, len); 2723 if (IS_ERR(skb)) 2724 return PTR_ERR(skb); 2725 2726 l2cap_do_send(chan, skb); 2727 err = len; 2728 break; 2729 2730 case L2CAP_MODE_ERTM: 2731 case L2CAP_MODE_STREAMING: 2732 /* Check outgoing MTU */ 2733 if (len > chan->omtu) { 2734 err = -EMSGSIZE; 2735 break; 2736 } 2737 2738 __skb_queue_head_init(&seg_queue); 2739 2740 /* Do segmentation before calling in to the state machine, 2741 * since it's possible to block while waiting for memory 2742 * allocation. 2743 */ 2744 err = l2cap_segment_sdu(chan, &seg_queue, msg, len); 2745 2746 if (err) 2747 break; 2748 2749 if (chan->mode == L2CAP_MODE_ERTM) 2750 l2cap_tx(chan, NULL, &seg_queue, L2CAP_EV_DATA_REQUEST); 2751 else 2752 l2cap_streaming_send(chan, &seg_queue); 2753 2754 err = len; 2755 2756 /* If the skbs were not queued for sending, they'll still be in 2757 * seg_queue and need to be purged. 2758 */ 2759 __skb_queue_purge(&seg_queue); 2760 break; 2761 2762 default: 2763 BT_DBG("bad state %1.1x", chan->mode); 2764 err = -EBADFD; 2765 } 2766 2767 return err; 2768 } 2769 EXPORT_SYMBOL_GPL(l2cap_chan_send); 2770 2771 static void l2cap_send_srej(struct l2cap_chan *chan, u16 txseq) 2772 { 2773 struct l2cap_ctrl control; 2774 u16 seq; 2775 2776 BT_DBG("chan %p, txseq %u", chan, txseq); 2777 2778 memset(&control, 0, sizeof(control)); 2779 control.sframe = 1; 2780 control.super = L2CAP_SUPER_SREJ; 2781 2782 for (seq = chan->expected_tx_seq; seq != txseq; 2783 seq = __next_seq(chan, seq)) { 2784 if (!l2cap_ertm_seq_in_queue(&chan->srej_q, seq)) { 2785 control.reqseq = seq; 2786 l2cap_send_sframe(chan, &control); 2787 l2cap_seq_list_append(&chan->srej_list, seq); 2788 } 2789 } 2790 2791 chan->expected_tx_seq = __next_seq(chan, txseq); 2792 } 2793 2794 static void l2cap_send_srej_tail(struct l2cap_chan *chan) 2795 { 2796 struct l2cap_ctrl control; 2797 2798 BT_DBG("chan %p", chan); 2799 2800 if (chan->srej_list.tail == L2CAP_SEQ_LIST_CLEAR) 2801 return; 2802 2803 memset(&control, 0, sizeof(control)); 2804 control.sframe = 1; 2805 control.super = L2CAP_SUPER_SREJ; 2806 control.reqseq = chan->srej_list.tail; 2807 l2cap_send_sframe(chan, &control); 2808 } 2809 2810 static void l2cap_send_srej_list(struct l2cap_chan *chan, u16 txseq) 2811 { 2812 struct l2cap_ctrl control; 2813 u16 initial_head; 2814 u16 seq; 2815 2816 BT_DBG("chan %p, txseq %u", chan, txseq); 2817 2818 memset(&control, 0, sizeof(control)); 2819 control.sframe = 1; 2820 control.super = L2CAP_SUPER_SREJ; 2821 2822 /* Capture initial list head to allow only one pass through the list. */ 2823 initial_head = chan->srej_list.head; 2824 2825 do { 2826 seq = l2cap_seq_list_pop(&chan->srej_list); 2827 if (seq == txseq || seq == L2CAP_SEQ_LIST_CLEAR) 2828 break; 2829 2830 control.reqseq = seq; 2831 l2cap_send_sframe(chan, &control); 2832 l2cap_seq_list_append(&chan->srej_list, seq); 2833 } while (chan->srej_list.head != initial_head); 2834 } 2835 2836 static void l2cap_process_reqseq(struct l2cap_chan *chan, u16 reqseq) 2837 { 2838 struct sk_buff *acked_skb; 2839 u16 ackseq; 2840 2841 BT_DBG("chan %p, reqseq %u", chan, reqseq); 2842 2843 if (chan->unacked_frames == 0 || reqseq == chan->expected_ack_seq) 2844 return; 2845 2846 BT_DBG("expected_ack_seq %u, unacked_frames %u", 2847 chan->expected_ack_seq, chan->unacked_frames); 2848 2849 for (ackseq = chan->expected_ack_seq; ackseq != reqseq; 2850 ackseq = __next_seq(chan, ackseq)) { 2851 2852 acked_skb = l2cap_ertm_seq_in_queue(&chan->tx_q, ackseq); 2853 if (acked_skb) { 2854 skb_unlink(acked_skb, &chan->tx_q); 2855 kfree_skb(acked_skb); 2856 chan->unacked_frames--; 2857 } 2858 } 2859 2860 chan->expected_ack_seq = reqseq; 2861 2862 if (chan->unacked_frames == 0) 2863 __clear_retrans_timer(chan); 2864 2865 BT_DBG("unacked_frames %u", chan->unacked_frames); 2866 } 2867 2868 static void l2cap_abort_rx_srej_sent(struct l2cap_chan *chan) 2869 { 2870 BT_DBG("chan %p", chan); 2871 2872 chan->expected_tx_seq = chan->buffer_seq; 2873 l2cap_seq_list_clear(&chan->srej_list); 2874 skb_queue_purge(&chan->srej_q); 2875 chan->rx_state = L2CAP_RX_STATE_RECV; 2876 } 2877 2878 static void l2cap_tx_state_xmit(struct l2cap_chan *chan, 2879 struct l2cap_ctrl *control, 2880 struct sk_buff_head *skbs, u8 event) 2881 { 2882 BT_DBG("chan %p, control %p, skbs %p, event %d", chan, control, skbs, 2883 event); 2884 2885 switch (event) { 2886 case L2CAP_EV_DATA_REQUEST: 2887 if (chan->tx_send_head == NULL) 2888 chan->tx_send_head = skb_peek(skbs); 2889 2890 skb_queue_splice_tail_init(skbs, &chan->tx_q); 2891 l2cap_ertm_send(chan); 2892 break; 2893 case L2CAP_EV_LOCAL_BUSY_DETECTED: 2894 BT_DBG("Enter LOCAL_BUSY"); 2895 set_bit(CONN_LOCAL_BUSY, &chan->conn_state); 2896 2897 if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) { 2898 /* The SREJ_SENT state must be aborted if we are to 2899 * enter the LOCAL_BUSY state. 2900 */ 2901 l2cap_abort_rx_srej_sent(chan); 2902 } 2903 2904 l2cap_send_ack(chan); 2905 2906 break; 2907 case L2CAP_EV_LOCAL_BUSY_CLEAR: 2908 BT_DBG("Exit LOCAL_BUSY"); 2909 clear_bit(CONN_LOCAL_BUSY, &chan->conn_state); 2910 2911 if (test_bit(CONN_RNR_SENT, &chan->conn_state)) { 2912 struct l2cap_ctrl local_control; 2913 2914 memset(&local_control, 0, sizeof(local_control)); 2915 local_control.sframe = 1; 2916 local_control.super = L2CAP_SUPER_RR; 2917 local_control.poll = 1; 2918 local_control.reqseq = chan->buffer_seq; 2919 l2cap_send_sframe(chan, &local_control); 2920 2921 chan->retry_count = 1; 2922 __set_monitor_timer(chan); 2923 chan->tx_state = L2CAP_TX_STATE_WAIT_F; 2924 } 2925 break; 2926 case L2CAP_EV_RECV_REQSEQ_AND_FBIT: 2927 l2cap_process_reqseq(chan, control->reqseq); 2928 break; 2929 case L2CAP_EV_EXPLICIT_POLL: 2930 l2cap_send_rr_or_rnr(chan, 1); 2931 chan->retry_count = 1; 2932 __set_monitor_timer(chan); 2933 __clear_ack_timer(chan); 2934 chan->tx_state = L2CAP_TX_STATE_WAIT_F; 2935 break; 2936 case L2CAP_EV_RETRANS_TO: 2937 l2cap_send_rr_or_rnr(chan, 1); 2938 chan->retry_count = 1; 2939 __set_monitor_timer(chan); 2940 chan->tx_state = L2CAP_TX_STATE_WAIT_F; 2941 break; 2942 case L2CAP_EV_RECV_FBIT: 2943 /* Nothing to process */ 2944 break; 2945 default: 2946 break; 2947 } 2948 } 2949 2950 static void l2cap_tx_state_wait_f(struct l2cap_chan *chan, 2951 struct l2cap_ctrl *control, 2952 struct sk_buff_head *skbs, u8 event) 2953 { 2954 BT_DBG("chan %p, control %p, skbs %p, event %d", chan, control, skbs, 2955 event); 2956 2957 switch (event) { 2958 case L2CAP_EV_DATA_REQUEST: 2959 if (chan->tx_send_head == NULL) 2960 chan->tx_send_head = skb_peek(skbs); 2961 /* Queue data, but don't send. */ 2962 skb_queue_splice_tail_init(skbs, &chan->tx_q); 2963 break; 2964 case L2CAP_EV_LOCAL_BUSY_DETECTED: 2965 BT_DBG("Enter LOCAL_BUSY"); 2966 set_bit(CONN_LOCAL_BUSY, &chan->conn_state); 2967 2968 if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) { 2969 /* The SREJ_SENT state must be aborted if we are to 2970 * enter the LOCAL_BUSY state. 2971 */ 2972 l2cap_abort_rx_srej_sent(chan); 2973 } 2974 2975 l2cap_send_ack(chan); 2976 2977 break; 2978 case L2CAP_EV_LOCAL_BUSY_CLEAR: 2979 BT_DBG("Exit LOCAL_BUSY"); 2980 clear_bit(CONN_LOCAL_BUSY, &chan->conn_state); 2981 2982 if (test_bit(CONN_RNR_SENT, &chan->conn_state)) { 2983 struct l2cap_ctrl local_control; 2984 memset(&local_control, 0, sizeof(local_control)); 2985 local_control.sframe = 1; 2986 local_control.super = L2CAP_SUPER_RR; 2987 local_control.poll = 1; 2988 local_control.reqseq = chan->buffer_seq; 2989 l2cap_send_sframe(chan, &local_control); 2990 2991 chan->retry_count = 1; 2992 __set_monitor_timer(chan); 2993 chan->tx_state = L2CAP_TX_STATE_WAIT_F; 2994 } 2995 break; 2996 case L2CAP_EV_RECV_REQSEQ_AND_FBIT: 2997 l2cap_process_reqseq(chan, control->reqseq); 2998 fallthrough; 2999 3000 case L2CAP_EV_RECV_FBIT: 3001 if (control && control->final) { 3002 __clear_monitor_timer(chan); 3003 if (chan->unacked_frames > 0) 3004 __set_retrans_timer(chan); 3005 chan->retry_count = 0; 3006 chan->tx_state = L2CAP_TX_STATE_XMIT; 3007 BT_DBG("recv fbit tx_state 0x2.2%x", chan->tx_state); 3008 } 3009 break; 3010 case L2CAP_EV_EXPLICIT_POLL: 3011 /* Ignore */ 3012 break; 3013 case L2CAP_EV_MONITOR_TO: 3014 if (chan->max_tx == 0 || chan->retry_count < chan->max_tx) { 3015 l2cap_send_rr_or_rnr(chan, 1); 3016 __set_monitor_timer(chan); 3017 chan->retry_count++; 3018 } else { 3019 l2cap_send_disconn_req(chan, ECONNABORTED); 3020 } 3021 break; 3022 default: 3023 break; 3024 } 3025 } 3026 3027 static void l2cap_tx(struct l2cap_chan *chan, struct l2cap_ctrl *control, 3028 struct sk_buff_head *skbs, u8 event) 3029 { 3030 BT_DBG("chan %p, control %p, skbs %p, event %d, state %d", 3031 chan, control, skbs, event, chan->tx_state); 3032 3033 switch (chan->tx_state) { 3034 case L2CAP_TX_STATE_XMIT: 3035 l2cap_tx_state_xmit(chan, control, skbs, event); 3036 break; 3037 case L2CAP_TX_STATE_WAIT_F: 3038 l2cap_tx_state_wait_f(chan, control, skbs, event); 3039 break; 3040 default: 3041 /* Ignore event */ 3042 break; 3043 } 3044 } 3045 3046 static void l2cap_pass_to_tx(struct l2cap_chan *chan, 3047 struct l2cap_ctrl *control) 3048 { 3049 BT_DBG("chan %p, control %p", chan, control); 3050 l2cap_tx(chan, control, NULL, L2CAP_EV_RECV_REQSEQ_AND_FBIT); 3051 } 3052 3053 static void l2cap_pass_to_tx_fbit(struct l2cap_chan *chan, 3054 struct l2cap_ctrl *control) 3055 { 3056 BT_DBG("chan %p, control %p", chan, control); 3057 l2cap_tx(chan, control, NULL, L2CAP_EV_RECV_FBIT); 3058 } 3059 3060 /* Copy frame to all raw sockets on that connection */ 3061 static void l2cap_raw_recv(struct l2cap_conn *conn, struct sk_buff *skb) 3062 { 3063 struct sk_buff *nskb; 3064 struct l2cap_chan *chan; 3065 3066 BT_DBG("conn %p", conn); 3067 3068 mutex_lock(&conn->chan_lock); 3069 3070 list_for_each_entry(chan, &conn->chan_l, list) { 3071 if (chan->chan_type != L2CAP_CHAN_RAW) 3072 continue; 3073 3074 /* Don't send frame to the channel it came from */ 3075 if (bt_cb(skb)->l2cap.chan == chan) 3076 continue; 3077 3078 nskb = skb_clone(skb, GFP_KERNEL); 3079 if (!nskb) 3080 continue; 3081 if (chan->ops->recv(chan, nskb)) 3082 kfree_skb(nskb); 3083 } 3084 3085 mutex_unlock(&conn->chan_lock); 3086 } 3087 3088 /* ---- L2CAP signalling commands ---- */ 3089 static struct sk_buff *l2cap_build_cmd(struct l2cap_conn *conn, u8 code, 3090 u8 ident, u16 dlen, void *data) 3091 { 3092 struct sk_buff *skb, **frag; 3093 struct l2cap_cmd_hdr *cmd; 3094 struct l2cap_hdr *lh; 3095 int len, count; 3096 3097 BT_DBG("conn %p, code 0x%2.2x, ident 0x%2.2x, len %u", 3098 conn, code, ident, dlen); 3099 3100 if (conn->mtu < L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE) 3101 return NULL; 3102 3103 len = L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE + dlen; 3104 count = min_t(unsigned int, conn->mtu, len); 3105 3106 skb = bt_skb_alloc(count, GFP_KERNEL); 3107 if (!skb) 3108 return NULL; 3109 3110 lh = skb_put(skb, L2CAP_HDR_SIZE); 3111 lh->len = cpu_to_le16(L2CAP_CMD_HDR_SIZE + dlen); 3112 3113 if (conn->hcon->type == LE_LINK) 3114 lh->cid = cpu_to_le16(L2CAP_CID_LE_SIGNALING); 3115 else 3116 lh->cid = cpu_to_le16(L2CAP_CID_SIGNALING); 3117 3118 cmd = skb_put(skb, L2CAP_CMD_HDR_SIZE); 3119 cmd->code = code; 3120 cmd->ident = ident; 3121 cmd->len = cpu_to_le16(dlen); 3122 3123 if (dlen) { 3124 count -= L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE; 3125 skb_put_data(skb, data, count); 3126 data += count; 3127 } 3128 3129 len -= skb->len; 3130 3131 /* Continuation fragments (no L2CAP header) */ 3132 frag = &skb_shinfo(skb)->frag_list; 3133 while (len) { 3134 count = min_t(unsigned int, conn->mtu, len); 3135 3136 *frag = bt_skb_alloc(count, GFP_KERNEL); 3137 if (!*frag) 3138 goto fail; 3139 3140 skb_put_data(*frag, data, count); 3141 3142 len -= count; 3143 data += count; 3144 3145 frag = &(*frag)->next; 3146 } 3147 3148 return skb; 3149 3150 fail: 3151 kfree_skb(skb); 3152 return NULL; 3153 } 3154 3155 static inline int l2cap_get_conf_opt(void **ptr, int *type, int *olen, 3156 unsigned long *val) 3157 { 3158 struct l2cap_conf_opt *opt = *ptr; 3159 int len; 3160 3161 len = L2CAP_CONF_OPT_SIZE + opt->len; 3162 *ptr += len; 3163 3164 *type = opt->type; 3165 *olen = opt->len; 3166 3167 switch (opt->len) { 3168 case 1: 3169 *val = *((u8 *) opt->val); 3170 break; 3171 3172 case 2: 3173 *val = get_unaligned_le16(opt->val); 3174 break; 3175 3176 case 4: 3177 *val = get_unaligned_le32(opt->val); 3178 break; 3179 3180 default: 3181 *val = (unsigned long) opt->val; 3182 break; 3183 } 3184 3185 BT_DBG("type 0x%2.2x len %u val 0x%lx", *type, opt->len, *val); 3186 return len; 3187 } 3188 3189 static void l2cap_add_conf_opt(void **ptr, u8 type, u8 len, unsigned long val, size_t size) 3190 { 3191 struct l2cap_conf_opt *opt = *ptr; 3192 3193 BT_DBG("type 0x%2.2x len %u val 0x%lx", type, len, val); 3194 3195 if (size < L2CAP_CONF_OPT_SIZE + len) 3196 return; 3197 3198 opt->type = type; 3199 opt->len = len; 3200 3201 switch (len) { 3202 case 1: 3203 *((u8 *) opt->val) = val; 3204 break; 3205 3206 case 2: 3207 put_unaligned_le16(val, opt->val); 3208 break; 3209 3210 case 4: 3211 put_unaligned_le32(val, opt->val); 3212 break; 3213 3214 default: 3215 memcpy(opt->val, (void *) val, len); 3216 break; 3217 } 3218 3219 *ptr += L2CAP_CONF_OPT_SIZE + len; 3220 } 3221 3222 static void l2cap_add_opt_efs(void **ptr, struct l2cap_chan *chan, size_t size) 3223 { 3224 struct l2cap_conf_efs efs; 3225 3226 switch (chan->mode) { 3227 case L2CAP_MODE_ERTM: 3228 efs.id = chan->local_id; 3229 efs.stype = chan->local_stype; 3230 efs.msdu = cpu_to_le16(chan->local_msdu); 3231 efs.sdu_itime = cpu_to_le32(chan->local_sdu_itime); 3232 efs.acc_lat = cpu_to_le32(L2CAP_DEFAULT_ACC_LAT); 3233 efs.flush_to = cpu_to_le32(L2CAP_EFS_DEFAULT_FLUSH_TO); 3234 break; 3235 3236 case L2CAP_MODE_STREAMING: 3237 efs.id = 1; 3238 efs.stype = L2CAP_SERV_BESTEFFORT; 3239 efs.msdu = cpu_to_le16(chan->local_msdu); 3240 efs.sdu_itime = cpu_to_le32(chan->local_sdu_itime); 3241 efs.acc_lat = 0; 3242 efs.flush_to = 0; 3243 break; 3244 3245 default: 3246 return; 3247 } 3248 3249 l2cap_add_conf_opt(ptr, L2CAP_CONF_EFS, sizeof(efs), 3250 (unsigned long) &efs, size); 3251 } 3252 3253 static void l2cap_ack_timeout(struct work_struct *work) 3254 { 3255 struct l2cap_chan *chan = container_of(work, struct l2cap_chan, 3256 ack_timer.work); 3257 u16 frames_to_ack; 3258 3259 BT_DBG("chan %p", chan); 3260 3261 l2cap_chan_lock(chan); 3262 3263 frames_to_ack = __seq_offset(chan, chan->buffer_seq, 3264 chan->last_acked_seq); 3265 3266 if (frames_to_ack) 3267 l2cap_send_rr_or_rnr(chan, 0); 3268 3269 l2cap_chan_unlock(chan); 3270 l2cap_chan_put(chan); 3271 } 3272 3273 int l2cap_ertm_init(struct l2cap_chan *chan) 3274 { 3275 int err; 3276 3277 chan->next_tx_seq = 0; 3278 chan->expected_tx_seq = 0; 3279 chan->expected_ack_seq = 0; 3280 chan->unacked_frames = 0; 3281 chan->buffer_seq = 0; 3282 chan->frames_sent = 0; 3283 chan->last_acked_seq = 0; 3284 chan->sdu = NULL; 3285 chan->sdu_last_frag = NULL; 3286 chan->sdu_len = 0; 3287 3288 skb_queue_head_init(&chan->tx_q); 3289 3290 chan->local_amp_id = AMP_ID_BREDR; 3291 chan->move_id = AMP_ID_BREDR; 3292 chan->move_state = L2CAP_MOVE_STABLE; 3293 chan->move_role = L2CAP_MOVE_ROLE_NONE; 3294 3295 if (chan->mode != L2CAP_MODE_ERTM) 3296 return 0; 3297 3298 chan->rx_state = L2CAP_RX_STATE_RECV; 3299 chan->tx_state = L2CAP_TX_STATE_XMIT; 3300 3301 skb_queue_head_init(&chan->srej_q); 3302 3303 err = l2cap_seq_list_init(&chan->srej_list, chan->tx_win); 3304 if (err < 0) 3305 return err; 3306 3307 err = l2cap_seq_list_init(&chan->retrans_list, chan->remote_tx_win); 3308 if (err < 0) 3309 l2cap_seq_list_free(&chan->srej_list); 3310 3311 return err; 3312 } 3313 3314 static inline __u8 l2cap_select_mode(__u8 mode, __u16 remote_feat_mask) 3315 { 3316 switch (mode) { 3317 case L2CAP_MODE_STREAMING: 3318 case L2CAP_MODE_ERTM: 3319 if (l2cap_mode_supported(mode, remote_feat_mask)) 3320 return mode; 3321 fallthrough; 3322 default: 3323 return L2CAP_MODE_BASIC; 3324 } 3325 } 3326 3327 static inline bool __l2cap_ews_supported(struct l2cap_conn *conn) 3328 { 3329 return ((conn->local_fixed_chan & L2CAP_FC_A2MP) && 3330 (conn->feat_mask & L2CAP_FEAT_EXT_WINDOW)); 3331 } 3332 3333 static inline bool __l2cap_efs_supported(struct l2cap_conn *conn) 3334 { 3335 return ((conn->local_fixed_chan & L2CAP_FC_A2MP) && 3336 (conn->feat_mask & L2CAP_FEAT_EXT_FLOW)); 3337 } 3338 3339 static void __l2cap_set_ertm_timeouts(struct l2cap_chan *chan, 3340 struct l2cap_conf_rfc *rfc) 3341 { 3342 if (chan->local_amp_id != AMP_ID_BREDR && chan->hs_hcon) { 3343 u64 ertm_to = chan->hs_hcon->hdev->amp_be_flush_to; 3344 3345 /* Class 1 devices have must have ERTM timeouts 3346 * exceeding the Link Supervision Timeout. The 3347 * default Link Supervision Timeout for AMP 3348 * controllers is 10 seconds. 3349 * 3350 * Class 1 devices use 0xffffffff for their 3351 * best-effort flush timeout, so the clamping logic 3352 * will result in a timeout that meets the above 3353 * requirement. ERTM timeouts are 16-bit values, so 3354 * the maximum timeout is 65.535 seconds. 3355 */ 3356 3357 /* Convert timeout to milliseconds and round */ 3358 ertm_to = DIV_ROUND_UP_ULL(ertm_to, 1000); 3359 3360 /* This is the recommended formula for class 2 devices 3361 * that start ERTM timers when packets are sent to the 3362 * controller. 3363 */ 3364 ertm_to = 3 * ertm_to + 500; 3365 3366 if (ertm_to > 0xffff) 3367 ertm_to = 0xffff; 3368 3369 rfc->retrans_timeout = cpu_to_le16((u16) ertm_to); 3370 rfc->monitor_timeout = rfc->retrans_timeout; 3371 } else { 3372 rfc->retrans_timeout = cpu_to_le16(L2CAP_DEFAULT_RETRANS_TO); 3373 rfc->monitor_timeout = cpu_to_le16(L2CAP_DEFAULT_MONITOR_TO); 3374 } 3375 } 3376 3377 static inline void l2cap_txwin_setup(struct l2cap_chan *chan) 3378 { 3379 if (chan->tx_win > L2CAP_DEFAULT_TX_WINDOW && 3380 __l2cap_ews_supported(chan->conn)) { 3381 /* use extended control field */ 3382 set_bit(FLAG_EXT_CTRL, &chan->flags); 3383 chan->tx_win_max = L2CAP_DEFAULT_EXT_WINDOW; 3384 } else { 3385 chan->tx_win = min_t(u16, chan->tx_win, 3386 L2CAP_DEFAULT_TX_WINDOW); 3387 chan->tx_win_max = L2CAP_DEFAULT_TX_WINDOW; 3388 } 3389 chan->ack_win = chan->tx_win; 3390 } 3391 3392 static void l2cap_mtu_auto(struct l2cap_chan *chan) 3393 { 3394 struct hci_conn *conn = chan->conn->hcon; 3395 3396 chan->imtu = L2CAP_DEFAULT_MIN_MTU; 3397 3398 /* The 2-DH1 packet has between 2 and 56 information bytes 3399 * (including the 2-byte payload header) 3400 */ 3401 if (!(conn->pkt_type & HCI_2DH1)) 3402 chan->imtu = 54; 3403 3404 /* The 3-DH1 packet has between 2 and 85 information bytes 3405 * (including the 2-byte payload header) 3406 */ 3407 if (!(conn->pkt_type & HCI_3DH1)) 3408 chan->imtu = 83; 3409 3410 /* The 2-DH3 packet has between 2 and 369 information bytes 3411 * (including the 2-byte payload header) 3412 */ 3413 if (!(conn->pkt_type & HCI_2DH3)) 3414 chan->imtu = 367; 3415 3416 /* The 3-DH3 packet has between 2 and 554 information bytes 3417 * (including the 2-byte payload header) 3418 */ 3419 if (!(conn->pkt_type & HCI_3DH3)) 3420 chan->imtu = 552; 3421 3422 /* The 2-DH5 packet has between 2 and 681 information bytes 3423 * (including the 2-byte payload header) 3424 */ 3425 if (!(conn->pkt_type & HCI_2DH5)) 3426 chan->imtu = 679; 3427 3428 /* The 3-DH5 packet has between 2 and 1023 information bytes 3429 * (including the 2-byte payload header) 3430 */ 3431 if (!(conn->pkt_type & HCI_3DH5)) 3432 chan->imtu = 1021; 3433 } 3434 3435 static int l2cap_build_conf_req(struct l2cap_chan *chan, void *data, size_t data_size) 3436 { 3437 struct l2cap_conf_req *req = data; 3438 struct l2cap_conf_rfc rfc = { .mode = chan->mode }; 3439 void *ptr = req->data; 3440 void *endptr = data + data_size; 3441 u16 size; 3442 3443 BT_DBG("chan %p", chan); 3444 3445 if (chan->num_conf_req || chan->num_conf_rsp) 3446 goto done; 3447 3448 switch (chan->mode) { 3449 case L2CAP_MODE_STREAMING: 3450 case L2CAP_MODE_ERTM: 3451 if (test_bit(CONF_STATE2_DEVICE, &chan->conf_state)) 3452 break; 3453 3454 if (__l2cap_efs_supported(chan->conn)) 3455 set_bit(FLAG_EFS_ENABLE, &chan->flags); 3456 3457 fallthrough; 3458 default: 3459 chan->mode = l2cap_select_mode(rfc.mode, chan->conn->feat_mask); 3460 break; 3461 } 3462 3463 done: 3464 if (chan->imtu != L2CAP_DEFAULT_MTU) { 3465 if (!chan->imtu) 3466 l2cap_mtu_auto(chan); 3467 l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, chan->imtu, 3468 endptr - ptr); 3469 } 3470 3471 switch (chan->mode) { 3472 case L2CAP_MODE_BASIC: 3473 if (disable_ertm) 3474 break; 3475 3476 if (!(chan->conn->feat_mask & L2CAP_FEAT_ERTM) && 3477 !(chan->conn->feat_mask & L2CAP_FEAT_STREAMING)) 3478 break; 3479 3480 rfc.mode = L2CAP_MODE_BASIC; 3481 rfc.txwin_size = 0; 3482 rfc.max_transmit = 0; 3483 rfc.retrans_timeout = 0; 3484 rfc.monitor_timeout = 0; 3485 rfc.max_pdu_size = 0; 3486 3487 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc), 3488 (unsigned long) &rfc, endptr - ptr); 3489 break; 3490 3491 case L2CAP_MODE_ERTM: 3492 rfc.mode = L2CAP_MODE_ERTM; 3493 rfc.max_transmit = chan->max_tx; 3494 3495 __l2cap_set_ertm_timeouts(chan, &rfc); 3496 3497 size = min_t(u16, L2CAP_DEFAULT_MAX_PDU_SIZE, chan->conn->mtu - 3498 L2CAP_EXT_HDR_SIZE - L2CAP_SDULEN_SIZE - 3499 L2CAP_FCS_SIZE); 3500 rfc.max_pdu_size = cpu_to_le16(size); 3501 3502 l2cap_txwin_setup(chan); 3503 3504 rfc.txwin_size = min_t(u16, chan->tx_win, 3505 L2CAP_DEFAULT_TX_WINDOW); 3506 3507 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc), 3508 (unsigned long) &rfc, endptr - ptr); 3509 3510 if (test_bit(FLAG_EFS_ENABLE, &chan->flags)) 3511 l2cap_add_opt_efs(&ptr, chan, endptr - ptr); 3512 3513 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) 3514 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EWS, 2, 3515 chan->tx_win, endptr - ptr); 3516 3517 if (chan->conn->feat_mask & L2CAP_FEAT_FCS) 3518 if (chan->fcs == L2CAP_FCS_NONE || 3519 test_bit(CONF_RECV_NO_FCS, &chan->conf_state)) { 3520 chan->fcs = L2CAP_FCS_NONE; 3521 l2cap_add_conf_opt(&ptr, L2CAP_CONF_FCS, 1, 3522 chan->fcs, endptr - ptr); 3523 } 3524 break; 3525 3526 case L2CAP_MODE_STREAMING: 3527 l2cap_txwin_setup(chan); 3528 rfc.mode = L2CAP_MODE_STREAMING; 3529 rfc.txwin_size = 0; 3530 rfc.max_transmit = 0; 3531 rfc.retrans_timeout = 0; 3532 rfc.monitor_timeout = 0; 3533 3534 size = min_t(u16, L2CAP_DEFAULT_MAX_PDU_SIZE, chan->conn->mtu - 3535 L2CAP_EXT_HDR_SIZE - L2CAP_SDULEN_SIZE - 3536 L2CAP_FCS_SIZE); 3537 rfc.max_pdu_size = cpu_to_le16(size); 3538 3539 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc), 3540 (unsigned long) &rfc, endptr - ptr); 3541 3542 if (test_bit(FLAG_EFS_ENABLE, &chan->flags)) 3543 l2cap_add_opt_efs(&ptr, chan, endptr - ptr); 3544 3545 if (chan->conn->feat_mask & L2CAP_FEAT_FCS) 3546 if (chan->fcs == L2CAP_FCS_NONE || 3547 test_bit(CONF_RECV_NO_FCS, &chan->conf_state)) { 3548 chan->fcs = L2CAP_FCS_NONE; 3549 l2cap_add_conf_opt(&ptr, L2CAP_CONF_FCS, 1, 3550 chan->fcs, endptr - ptr); 3551 } 3552 break; 3553 } 3554 3555 req->dcid = cpu_to_le16(chan->dcid); 3556 req->flags = cpu_to_le16(0); 3557 3558 return ptr - data; 3559 } 3560 3561 static int l2cap_parse_conf_req(struct l2cap_chan *chan, void *data, size_t data_size) 3562 { 3563 struct l2cap_conf_rsp *rsp = data; 3564 void *ptr = rsp->data; 3565 void *endptr = data + data_size; 3566 void *req = chan->conf_req; 3567 int len = chan->conf_len; 3568 int type, hint, olen; 3569 unsigned long val; 3570 struct l2cap_conf_rfc rfc = { .mode = L2CAP_MODE_BASIC }; 3571 struct l2cap_conf_efs efs; 3572 u8 remote_efs = 0; 3573 u16 mtu = L2CAP_DEFAULT_MTU; 3574 u16 result = L2CAP_CONF_SUCCESS; 3575 u16 size; 3576 3577 BT_DBG("chan %p", chan); 3578 3579 while (len >= L2CAP_CONF_OPT_SIZE) { 3580 len -= l2cap_get_conf_opt(&req, &type, &olen, &val); 3581 if (len < 0) 3582 break; 3583 3584 hint = type & L2CAP_CONF_HINT; 3585 type &= L2CAP_CONF_MASK; 3586 3587 switch (type) { 3588 case L2CAP_CONF_MTU: 3589 if (olen != 2) 3590 break; 3591 mtu = val; 3592 break; 3593 3594 case L2CAP_CONF_FLUSH_TO: 3595 if (olen != 2) 3596 break; 3597 chan->flush_to = val; 3598 break; 3599 3600 case L2CAP_CONF_QOS: 3601 break; 3602 3603 case L2CAP_CONF_RFC: 3604 if (olen != sizeof(rfc)) 3605 break; 3606 memcpy(&rfc, (void *) val, olen); 3607 break; 3608 3609 case L2CAP_CONF_FCS: 3610 if (olen != 1) 3611 break; 3612 if (val == L2CAP_FCS_NONE) 3613 set_bit(CONF_RECV_NO_FCS, &chan->conf_state); 3614 break; 3615 3616 case L2CAP_CONF_EFS: 3617 if (olen != sizeof(efs)) 3618 break; 3619 remote_efs = 1; 3620 memcpy(&efs, (void *) val, olen); 3621 break; 3622 3623 case L2CAP_CONF_EWS: 3624 if (olen != 2) 3625 break; 3626 if (!(chan->conn->local_fixed_chan & L2CAP_FC_A2MP)) 3627 return -ECONNREFUSED; 3628 set_bit(FLAG_EXT_CTRL, &chan->flags); 3629 set_bit(CONF_EWS_RECV, &chan->conf_state); 3630 chan->tx_win_max = L2CAP_DEFAULT_EXT_WINDOW; 3631 chan->remote_tx_win = val; 3632 break; 3633 3634 default: 3635 if (hint) 3636 break; 3637 result = L2CAP_CONF_UNKNOWN; 3638 l2cap_add_conf_opt(&ptr, (u8)type, sizeof(u8), type, endptr - ptr); 3639 break; 3640 } 3641 } 3642 3643 if (chan->num_conf_rsp || chan->num_conf_req > 1) 3644 goto done; 3645 3646 switch (chan->mode) { 3647 case L2CAP_MODE_STREAMING: 3648 case L2CAP_MODE_ERTM: 3649 if (!test_bit(CONF_STATE2_DEVICE, &chan->conf_state)) { 3650 chan->mode = l2cap_select_mode(rfc.mode, 3651 chan->conn->feat_mask); 3652 break; 3653 } 3654 3655 if (remote_efs) { 3656 if (__l2cap_efs_supported(chan->conn)) 3657 set_bit(FLAG_EFS_ENABLE, &chan->flags); 3658 else 3659 return -ECONNREFUSED; 3660 } 3661 3662 if (chan->mode != rfc.mode) 3663 return -ECONNREFUSED; 3664 3665 break; 3666 } 3667 3668 done: 3669 if (chan->mode != rfc.mode) { 3670 result = L2CAP_CONF_UNACCEPT; 3671 rfc.mode = chan->mode; 3672 3673 if (chan->num_conf_rsp == 1) 3674 return -ECONNREFUSED; 3675 3676 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc), 3677 (unsigned long) &rfc, endptr - ptr); 3678 } 3679 3680 if (result == L2CAP_CONF_SUCCESS) { 3681 /* Configure output options and let the other side know 3682 * which ones we don't like. */ 3683 3684 if (mtu < L2CAP_DEFAULT_MIN_MTU) 3685 result = L2CAP_CONF_UNACCEPT; 3686 else { 3687 chan->omtu = mtu; 3688 set_bit(CONF_MTU_DONE, &chan->conf_state); 3689 } 3690 l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, chan->omtu, endptr - ptr); 3691 3692 if (remote_efs) { 3693 if (chan->local_stype != L2CAP_SERV_NOTRAFIC && 3694 efs.stype != L2CAP_SERV_NOTRAFIC && 3695 efs.stype != chan->local_stype) { 3696 3697 result = L2CAP_CONF_UNACCEPT; 3698 3699 if (chan->num_conf_req >= 1) 3700 return -ECONNREFUSED; 3701 3702 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS, 3703 sizeof(efs), 3704 (unsigned long) &efs, endptr - ptr); 3705 } else { 3706 /* Send PENDING Conf Rsp */ 3707 result = L2CAP_CONF_PENDING; 3708 set_bit(CONF_LOC_CONF_PEND, &chan->conf_state); 3709 } 3710 } 3711 3712 switch (rfc.mode) { 3713 case L2CAP_MODE_BASIC: 3714 chan->fcs = L2CAP_FCS_NONE; 3715 set_bit(CONF_MODE_DONE, &chan->conf_state); 3716 break; 3717 3718 case L2CAP_MODE_ERTM: 3719 if (!test_bit(CONF_EWS_RECV, &chan->conf_state)) 3720 chan->remote_tx_win = rfc.txwin_size; 3721 else 3722 rfc.txwin_size = L2CAP_DEFAULT_TX_WINDOW; 3723 3724 chan->remote_max_tx = rfc.max_transmit; 3725 3726 size = min_t(u16, le16_to_cpu(rfc.max_pdu_size), 3727 chan->conn->mtu - L2CAP_EXT_HDR_SIZE - 3728 L2CAP_SDULEN_SIZE - L2CAP_FCS_SIZE); 3729 rfc.max_pdu_size = cpu_to_le16(size); 3730 chan->remote_mps = size; 3731 3732 __l2cap_set_ertm_timeouts(chan, &rfc); 3733 3734 set_bit(CONF_MODE_DONE, &chan->conf_state); 3735 3736 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, 3737 sizeof(rfc), (unsigned long) &rfc, endptr - ptr); 3738 3739 if (remote_efs && 3740 test_bit(FLAG_EFS_ENABLE, &chan->flags)) { 3741 chan->remote_id = efs.id; 3742 chan->remote_stype = efs.stype; 3743 chan->remote_msdu = le16_to_cpu(efs.msdu); 3744 chan->remote_flush_to = 3745 le32_to_cpu(efs.flush_to); 3746 chan->remote_acc_lat = 3747 le32_to_cpu(efs.acc_lat); 3748 chan->remote_sdu_itime = 3749 le32_to_cpu(efs.sdu_itime); 3750 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS, 3751 sizeof(efs), 3752 (unsigned long) &efs, endptr - ptr); 3753 } 3754 break; 3755 3756 case L2CAP_MODE_STREAMING: 3757 size = min_t(u16, le16_to_cpu(rfc.max_pdu_size), 3758 chan->conn->mtu - L2CAP_EXT_HDR_SIZE - 3759 L2CAP_SDULEN_SIZE - L2CAP_FCS_SIZE); 3760 rfc.max_pdu_size = cpu_to_le16(size); 3761 chan->remote_mps = size; 3762 3763 set_bit(CONF_MODE_DONE, &chan->conf_state); 3764 3765 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc), 3766 (unsigned long) &rfc, endptr - ptr); 3767 3768 break; 3769 3770 default: 3771 result = L2CAP_CONF_UNACCEPT; 3772 3773 memset(&rfc, 0, sizeof(rfc)); 3774 rfc.mode = chan->mode; 3775 } 3776 3777 if (result == L2CAP_CONF_SUCCESS) 3778 set_bit(CONF_OUTPUT_DONE, &chan->conf_state); 3779 } 3780 rsp->scid = cpu_to_le16(chan->dcid); 3781 rsp->result = cpu_to_le16(result); 3782 rsp->flags = cpu_to_le16(0); 3783 3784 return ptr - data; 3785 } 3786 3787 static int l2cap_parse_conf_rsp(struct l2cap_chan *chan, void *rsp, int len, 3788 void *data, size_t size, u16 *result) 3789 { 3790 struct l2cap_conf_req *req = data; 3791 void *ptr = req->data; 3792 void *endptr = data + size; 3793 int type, olen; 3794 unsigned long val; 3795 struct l2cap_conf_rfc rfc = { .mode = L2CAP_MODE_BASIC }; 3796 struct l2cap_conf_efs efs; 3797 3798 BT_DBG("chan %p, rsp %p, len %d, req %p", chan, rsp, len, data); 3799 3800 while (len >= L2CAP_CONF_OPT_SIZE) { 3801 len -= l2cap_get_conf_opt(&rsp, &type, &olen, &val); 3802 if (len < 0) 3803 break; 3804 3805 switch (type) { 3806 case L2CAP_CONF_MTU: 3807 if (olen != 2) 3808 break; 3809 if (val < L2CAP_DEFAULT_MIN_MTU) { 3810 *result = L2CAP_CONF_UNACCEPT; 3811 chan->imtu = L2CAP_DEFAULT_MIN_MTU; 3812 } else 3813 chan->imtu = val; 3814 l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, chan->imtu, 3815 endptr - ptr); 3816 break; 3817 3818 case L2CAP_CONF_FLUSH_TO: 3819 if (olen != 2) 3820 break; 3821 chan->flush_to = val; 3822 l2cap_add_conf_opt(&ptr, L2CAP_CONF_FLUSH_TO, 2, 3823 chan->flush_to, endptr - ptr); 3824 break; 3825 3826 case L2CAP_CONF_RFC: 3827 if (olen != sizeof(rfc)) 3828 break; 3829 memcpy(&rfc, (void *)val, olen); 3830 if (test_bit(CONF_STATE2_DEVICE, &chan->conf_state) && 3831 rfc.mode != chan->mode) 3832 return -ECONNREFUSED; 3833 chan->fcs = 0; 3834 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc), 3835 (unsigned long) &rfc, endptr - ptr); 3836 break; 3837 3838 case L2CAP_CONF_EWS: 3839 if (olen != 2) 3840 break; 3841 chan->ack_win = min_t(u16, val, chan->ack_win); 3842 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EWS, 2, 3843 chan->tx_win, endptr - ptr); 3844 break; 3845 3846 case L2CAP_CONF_EFS: 3847 if (olen != sizeof(efs)) 3848 break; 3849 memcpy(&efs, (void *)val, olen); 3850 if (chan->local_stype != L2CAP_SERV_NOTRAFIC && 3851 efs.stype != L2CAP_SERV_NOTRAFIC && 3852 efs.stype != chan->local_stype) 3853 return -ECONNREFUSED; 3854 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS, sizeof(efs), 3855 (unsigned long) &efs, endptr - ptr); 3856 break; 3857 3858 case L2CAP_CONF_FCS: 3859 if (olen != 1) 3860 break; 3861 if (*result == L2CAP_CONF_PENDING) 3862 if (val == L2CAP_FCS_NONE) 3863 set_bit(CONF_RECV_NO_FCS, 3864 &chan->conf_state); 3865 break; 3866 } 3867 } 3868 3869 if (chan->mode == L2CAP_MODE_BASIC && chan->mode != rfc.mode) 3870 return -ECONNREFUSED; 3871 3872 chan->mode = rfc.mode; 3873 3874 if (*result == L2CAP_CONF_SUCCESS || *result == L2CAP_CONF_PENDING) { 3875 switch (rfc.mode) { 3876 case L2CAP_MODE_ERTM: 3877 chan->retrans_timeout = le16_to_cpu(rfc.retrans_timeout); 3878 chan->monitor_timeout = le16_to_cpu(rfc.monitor_timeout); 3879 chan->mps = le16_to_cpu(rfc.max_pdu_size); 3880 if (!test_bit(FLAG_EXT_CTRL, &chan->flags)) 3881 chan->ack_win = min_t(u16, chan->ack_win, 3882 rfc.txwin_size); 3883 3884 if (test_bit(FLAG_EFS_ENABLE, &chan->flags)) { 3885 chan->local_msdu = le16_to_cpu(efs.msdu); 3886 chan->local_sdu_itime = 3887 le32_to_cpu(efs.sdu_itime); 3888 chan->local_acc_lat = le32_to_cpu(efs.acc_lat); 3889 chan->local_flush_to = 3890 le32_to_cpu(efs.flush_to); 3891 } 3892 break; 3893 3894 case L2CAP_MODE_STREAMING: 3895 chan->mps = le16_to_cpu(rfc.max_pdu_size); 3896 } 3897 } 3898 3899 req->dcid = cpu_to_le16(chan->dcid); 3900 req->flags = cpu_to_le16(0); 3901 3902 return ptr - data; 3903 } 3904 3905 static int l2cap_build_conf_rsp(struct l2cap_chan *chan, void *data, 3906 u16 result, u16 flags) 3907 { 3908 struct l2cap_conf_rsp *rsp = data; 3909 void *ptr = rsp->data; 3910 3911 BT_DBG("chan %p", chan); 3912 3913 rsp->scid = cpu_to_le16(chan->dcid); 3914 rsp->result = cpu_to_le16(result); 3915 rsp->flags = cpu_to_le16(flags); 3916 3917 return ptr - data; 3918 } 3919 3920 void __l2cap_le_connect_rsp_defer(struct l2cap_chan *chan) 3921 { 3922 struct l2cap_le_conn_rsp rsp; 3923 struct l2cap_conn *conn = chan->conn; 3924 3925 BT_DBG("chan %p", chan); 3926 3927 rsp.dcid = cpu_to_le16(chan->scid); 3928 rsp.mtu = cpu_to_le16(chan->imtu); 3929 rsp.mps = cpu_to_le16(chan->mps); 3930 rsp.credits = cpu_to_le16(chan->rx_credits); 3931 rsp.result = cpu_to_le16(L2CAP_CR_LE_SUCCESS); 3932 3933 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_RSP, sizeof(rsp), 3934 &rsp); 3935 } 3936 3937 static void l2cap_ecred_list_defer(struct l2cap_chan *chan, void *data) 3938 { 3939 int *result = data; 3940 3941 if (*result || test_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags)) 3942 return; 3943 3944 switch (chan->state) { 3945 case BT_CONNECT2: 3946 /* If channel still pending accept add to result */ 3947 (*result)++; 3948 return; 3949 case BT_CONNECTED: 3950 return; 3951 default: 3952 /* If not connected or pending accept it has been refused */ 3953 *result = -ECONNREFUSED; 3954 return; 3955 } 3956 } 3957 3958 struct l2cap_ecred_rsp_data { 3959 struct { 3960 struct l2cap_ecred_conn_rsp rsp; 3961 __le16 scid[L2CAP_ECRED_MAX_CID]; 3962 } __packed pdu; 3963 int count; 3964 }; 3965 3966 static void l2cap_ecred_rsp_defer(struct l2cap_chan *chan, void *data) 3967 { 3968 struct l2cap_ecred_rsp_data *rsp = data; 3969 3970 if (test_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags)) 3971 return; 3972 3973 /* Reset ident so only one response is sent */ 3974 chan->ident = 0; 3975 3976 /* Include all channels pending with the same ident */ 3977 if (!rsp->pdu.rsp.result) 3978 rsp->pdu.rsp.dcid[rsp->count++] = cpu_to_le16(chan->scid); 3979 else 3980 l2cap_chan_del(chan, ECONNRESET); 3981 } 3982 3983 void __l2cap_ecred_conn_rsp_defer(struct l2cap_chan *chan) 3984 { 3985 struct l2cap_conn *conn = chan->conn; 3986 struct l2cap_ecred_rsp_data data; 3987 u16 id = chan->ident; 3988 int result = 0; 3989 3990 if (!id) 3991 return; 3992 3993 BT_DBG("chan %p id %d", chan, id); 3994 3995 memset(&data, 0, sizeof(data)); 3996 3997 data.pdu.rsp.mtu = cpu_to_le16(chan->imtu); 3998 data.pdu.rsp.mps = cpu_to_le16(chan->mps); 3999 data.pdu.rsp.credits = cpu_to_le16(chan->rx_credits); 4000 data.pdu.rsp.result = cpu_to_le16(L2CAP_CR_LE_SUCCESS); 4001 4002 /* Verify that all channels are ready */ 4003 __l2cap_chan_list_id(conn, id, l2cap_ecred_list_defer, &result); 4004 4005 if (result > 0) 4006 return; 4007 4008 if (result < 0) 4009 data.pdu.rsp.result = cpu_to_le16(L2CAP_CR_LE_AUTHORIZATION); 4010 4011 /* Build response */ 4012 __l2cap_chan_list_id(conn, id, l2cap_ecred_rsp_defer, &data); 4013 4014 l2cap_send_cmd(conn, id, L2CAP_ECRED_CONN_RSP, 4015 sizeof(data.pdu.rsp) + (data.count * sizeof(__le16)), 4016 &data.pdu); 4017 } 4018 4019 void __l2cap_connect_rsp_defer(struct l2cap_chan *chan) 4020 { 4021 struct l2cap_conn_rsp rsp; 4022 struct l2cap_conn *conn = chan->conn; 4023 u8 buf[128]; 4024 u8 rsp_code; 4025 4026 rsp.scid = cpu_to_le16(chan->dcid); 4027 rsp.dcid = cpu_to_le16(chan->scid); 4028 rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS); 4029 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO); 4030 4031 if (chan->hs_hcon) 4032 rsp_code = L2CAP_CREATE_CHAN_RSP; 4033 else 4034 rsp_code = L2CAP_CONN_RSP; 4035 4036 BT_DBG("chan %p rsp_code %u", chan, rsp_code); 4037 4038 l2cap_send_cmd(conn, chan->ident, rsp_code, sizeof(rsp), &rsp); 4039 4040 if (test_and_set_bit(CONF_REQ_SENT, &chan->conf_state)) 4041 return; 4042 4043 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ, 4044 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf); 4045 chan->num_conf_req++; 4046 } 4047 4048 static void l2cap_conf_rfc_get(struct l2cap_chan *chan, void *rsp, int len) 4049 { 4050 int type, olen; 4051 unsigned long val; 4052 /* Use sane default values in case a misbehaving remote device 4053 * did not send an RFC or extended window size option. 4054 */ 4055 u16 txwin_ext = chan->ack_win; 4056 struct l2cap_conf_rfc rfc = { 4057 .mode = chan->mode, 4058 .retrans_timeout = cpu_to_le16(L2CAP_DEFAULT_RETRANS_TO), 4059 .monitor_timeout = cpu_to_le16(L2CAP_DEFAULT_MONITOR_TO), 4060 .max_pdu_size = cpu_to_le16(chan->imtu), 4061 .txwin_size = min_t(u16, chan->ack_win, L2CAP_DEFAULT_TX_WINDOW), 4062 }; 4063 4064 BT_DBG("chan %p, rsp %p, len %d", chan, rsp, len); 4065 4066 if ((chan->mode != L2CAP_MODE_ERTM) && (chan->mode != L2CAP_MODE_STREAMING)) 4067 return; 4068 4069 while (len >= L2CAP_CONF_OPT_SIZE) { 4070 len -= l2cap_get_conf_opt(&rsp, &type, &olen, &val); 4071 if (len < 0) 4072 break; 4073 4074 switch (type) { 4075 case L2CAP_CONF_RFC: 4076 if (olen != sizeof(rfc)) 4077 break; 4078 memcpy(&rfc, (void *)val, olen); 4079 break; 4080 case L2CAP_CONF_EWS: 4081 if (olen != 2) 4082 break; 4083 txwin_ext = val; 4084 break; 4085 } 4086 } 4087 4088 switch (rfc.mode) { 4089 case L2CAP_MODE_ERTM: 4090 chan->retrans_timeout = le16_to_cpu(rfc.retrans_timeout); 4091 chan->monitor_timeout = le16_to_cpu(rfc.monitor_timeout); 4092 chan->mps = le16_to_cpu(rfc.max_pdu_size); 4093 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) 4094 chan->ack_win = min_t(u16, chan->ack_win, txwin_ext); 4095 else 4096 chan->ack_win = min_t(u16, chan->ack_win, 4097 rfc.txwin_size); 4098 break; 4099 case L2CAP_MODE_STREAMING: 4100 chan->mps = le16_to_cpu(rfc.max_pdu_size); 4101 } 4102 } 4103 4104 static inline int l2cap_command_rej(struct l2cap_conn *conn, 4105 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4106 u8 *data) 4107 { 4108 struct l2cap_cmd_rej_unk *rej = (struct l2cap_cmd_rej_unk *) data; 4109 4110 if (cmd_len < sizeof(*rej)) 4111 return -EPROTO; 4112 4113 if (rej->reason != L2CAP_REJ_NOT_UNDERSTOOD) 4114 return 0; 4115 4116 if ((conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT) && 4117 cmd->ident == conn->info_ident) { 4118 cancel_delayed_work(&conn->info_timer); 4119 4120 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE; 4121 conn->info_ident = 0; 4122 4123 l2cap_conn_start(conn); 4124 } 4125 4126 return 0; 4127 } 4128 4129 static struct l2cap_chan *l2cap_connect(struct l2cap_conn *conn, 4130 struct l2cap_cmd_hdr *cmd, 4131 u8 *data, u8 rsp_code, u8 amp_id) 4132 { 4133 struct l2cap_conn_req *req = (struct l2cap_conn_req *) data; 4134 struct l2cap_conn_rsp rsp; 4135 struct l2cap_chan *chan = NULL, *pchan; 4136 int result, status = L2CAP_CS_NO_INFO; 4137 4138 u16 dcid = 0, scid = __le16_to_cpu(req->scid); 4139 __le16 psm = req->psm; 4140 4141 BT_DBG("psm 0x%2.2x scid 0x%4.4x", __le16_to_cpu(psm), scid); 4142 4143 /* Check if we have socket listening on psm */ 4144 pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src, 4145 &conn->hcon->dst, ACL_LINK); 4146 if (!pchan) { 4147 result = L2CAP_CR_BAD_PSM; 4148 goto sendresp; 4149 } 4150 4151 mutex_lock(&conn->chan_lock); 4152 l2cap_chan_lock(pchan); 4153 4154 /* Check if the ACL is secure enough (if not SDP) */ 4155 if (psm != cpu_to_le16(L2CAP_PSM_SDP) && 4156 !hci_conn_check_link_mode(conn->hcon)) { 4157 conn->disc_reason = HCI_ERROR_AUTH_FAILURE; 4158 result = L2CAP_CR_SEC_BLOCK; 4159 goto response; 4160 } 4161 4162 result = L2CAP_CR_NO_MEM; 4163 4164 /* Check for valid dynamic CID range (as per Erratum 3253) */ 4165 if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_DYN_END) { 4166 result = L2CAP_CR_INVALID_SCID; 4167 goto response; 4168 } 4169 4170 /* Check if we already have channel with that dcid */ 4171 if (__l2cap_get_chan_by_dcid(conn, scid)) { 4172 result = L2CAP_CR_SCID_IN_USE; 4173 goto response; 4174 } 4175 4176 chan = pchan->ops->new_connection(pchan); 4177 if (!chan) 4178 goto response; 4179 4180 /* For certain devices (ex: HID mouse), support for authentication, 4181 * pairing and bonding is optional. For such devices, inorder to avoid 4182 * the ACL alive for too long after L2CAP disconnection, reset the ACL 4183 * disc_timeout back to HCI_DISCONN_TIMEOUT during L2CAP connect. 4184 */ 4185 conn->hcon->disc_timeout = HCI_DISCONN_TIMEOUT; 4186 4187 bacpy(&chan->src, &conn->hcon->src); 4188 bacpy(&chan->dst, &conn->hcon->dst); 4189 chan->src_type = bdaddr_src_type(conn->hcon); 4190 chan->dst_type = bdaddr_dst_type(conn->hcon); 4191 chan->psm = psm; 4192 chan->dcid = scid; 4193 chan->local_amp_id = amp_id; 4194 4195 __l2cap_chan_add(conn, chan); 4196 4197 dcid = chan->scid; 4198 4199 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan)); 4200 4201 chan->ident = cmd->ident; 4202 4203 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE) { 4204 if (l2cap_chan_check_security(chan, false)) { 4205 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) { 4206 l2cap_state_change(chan, BT_CONNECT2); 4207 result = L2CAP_CR_PEND; 4208 status = L2CAP_CS_AUTHOR_PEND; 4209 chan->ops->defer(chan); 4210 } else { 4211 /* Force pending result for AMP controllers. 4212 * The connection will succeed after the 4213 * physical link is up. 4214 */ 4215 if (amp_id == AMP_ID_BREDR) { 4216 l2cap_state_change(chan, BT_CONFIG); 4217 result = L2CAP_CR_SUCCESS; 4218 } else { 4219 l2cap_state_change(chan, BT_CONNECT2); 4220 result = L2CAP_CR_PEND; 4221 } 4222 status = L2CAP_CS_NO_INFO; 4223 } 4224 } else { 4225 l2cap_state_change(chan, BT_CONNECT2); 4226 result = L2CAP_CR_PEND; 4227 status = L2CAP_CS_AUTHEN_PEND; 4228 } 4229 } else { 4230 l2cap_state_change(chan, BT_CONNECT2); 4231 result = L2CAP_CR_PEND; 4232 status = L2CAP_CS_NO_INFO; 4233 } 4234 4235 response: 4236 l2cap_chan_unlock(pchan); 4237 mutex_unlock(&conn->chan_lock); 4238 l2cap_chan_put(pchan); 4239 4240 sendresp: 4241 rsp.scid = cpu_to_le16(scid); 4242 rsp.dcid = cpu_to_le16(dcid); 4243 rsp.result = cpu_to_le16(result); 4244 rsp.status = cpu_to_le16(status); 4245 l2cap_send_cmd(conn, cmd->ident, rsp_code, sizeof(rsp), &rsp); 4246 4247 if (result == L2CAP_CR_PEND && status == L2CAP_CS_NO_INFO) { 4248 struct l2cap_info_req info; 4249 info.type = cpu_to_le16(L2CAP_IT_FEAT_MASK); 4250 4251 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_SENT; 4252 conn->info_ident = l2cap_get_ident(conn); 4253 4254 schedule_delayed_work(&conn->info_timer, L2CAP_INFO_TIMEOUT); 4255 4256 l2cap_send_cmd(conn, conn->info_ident, L2CAP_INFO_REQ, 4257 sizeof(info), &info); 4258 } 4259 4260 if (chan && !test_bit(CONF_REQ_SENT, &chan->conf_state) && 4261 result == L2CAP_CR_SUCCESS) { 4262 u8 buf[128]; 4263 set_bit(CONF_REQ_SENT, &chan->conf_state); 4264 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ, 4265 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf); 4266 chan->num_conf_req++; 4267 } 4268 4269 return chan; 4270 } 4271 4272 static int l2cap_connect_req(struct l2cap_conn *conn, 4273 struct l2cap_cmd_hdr *cmd, u16 cmd_len, u8 *data) 4274 { 4275 struct hci_dev *hdev = conn->hcon->hdev; 4276 struct hci_conn *hcon = conn->hcon; 4277 4278 if (cmd_len < sizeof(struct l2cap_conn_req)) 4279 return -EPROTO; 4280 4281 hci_dev_lock(hdev); 4282 if (hci_dev_test_flag(hdev, HCI_MGMT) && 4283 !test_and_set_bit(HCI_CONN_MGMT_CONNECTED, &hcon->flags)) 4284 mgmt_device_connected(hdev, hcon, NULL, 0); 4285 hci_dev_unlock(hdev); 4286 4287 l2cap_connect(conn, cmd, data, L2CAP_CONN_RSP, 0); 4288 return 0; 4289 } 4290 4291 static int l2cap_connect_create_rsp(struct l2cap_conn *conn, 4292 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4293 u8 *data) 4294 { 4295 struct l2cap_conn_rsp *rsp = (struct l2cap_conn_rsp *) data; 4296 u16 scid, dcid, result, status; 4297 struct l2cap_chan *chan; 4298 u8 req[128]; 4299 int err; 4300 4301 if (cmd_len < sizeof(*rsp)) 4302 return -EPROTO; 4303 4304 scid = __le16_to_cpu(rsp->scid); 4305 dcid = __le16_to_cpu(rsp->dcid); 4306 result = __le16_to_cpu(rsp->result); 4307 status = __le16_to_cpu(rsp->status); 4308 4309 if (result == L2CAP_CR_SUCCESS && (dcid < L2CAP_CID_DYN_START || 4310 dcid > L2CAP_CID_DYN_END)) 4311 return -EPROTO; 4312 4313 BT_DBG("dcid 0x%4.4x scid 0x%4.4x result 0x%2.2x status 0x%2.2x", 4314 dcid, scid, result, status); 4315 4316 mutex_lock(&conn->chan_lock); 4317 4318 if (scid) { 4319 chan = __l2cap_get_chan_by_scid(conn, scid); 4320 if (!chan) { 4321 err = -EBADSLT; 4322 goto unlock; 4323 } 4324 } else { 4325 chan = __l2cap_get_chan_by_ident(conn, cmd->ident); 4326 if (!chan) { 4327 err = -EBADSLT; 4328 goto unlock; 4329 } 4330 } 4331 4332 chan = l2cap_chan_hold_unless_zero(chan); 4333 if (!chan) { 4334 err = -EBADSLT; 4335 goto unlock; 4336 } 4337 4338 err = 0; 4339 4340 l2cap_chan_lock(chan); 4341 4342 switch (result) { 4343 case L2CAP_CR_SUCCESS: 4344 if (__l2cap_get_chan_by_dcid(conn, dcid)) { 4345 err = -EBADSLT; 4346 break; 4347 } 4348 4349 l2cap_state_change(chan, BT_CONFIG); 4350 chan->ident = 0; 4351 chan->dcid = dcid; 4352 clear_bit(CONF_CONNECT_PEND, &chan->conf_state); 4353 4354 if (test_and_set_bit(CONF_REQ_SENT, &chan->conf_state)) 4355 break; 4356 4357 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ, 4358 l2cap_build_conf_req(chan, req, sizeof(req)), req); 4359 chan->num_conf_req++; 4360 break; 4361 4362 case L2CAP_CR_PEND: 4363 set_bit(CONF_CONNECT_PEND, &chan->conf_state); 4364 break; 4365 4366 default: 4367 l2cap_chan_del(chan, ECONNREFUSED); 4368 break; 4369 } 4370 4371 l2cap_chan_unlock(chan); 4372 l2cap_chan_put(chan); 4373 4374 unlock: 4375 mutex_unlock(&conn->chan_lock); 4376 4377 return err; 4378 } 4379 4380 static inline void set_default_fcs(struct l2cap_chan *chan) 4381 { 4382 /* FCS is enabled only in ERTM or streaming mode, if one or both 4383 * sides request it. 4384 */ 4385 if (chan->mode != L2CAP_MODE_ERTM && chan->mode != L2CAP_MODE_STREAMING) 4386 chan->fcs = L2CAP_FCS_NONE; 4387 else if (!test_bit(CONF_RECV_NO_FCS, &chan->conf_state)) 4388 chan->fcs = L2CAP_FCS_CRC16; 4389 } 4390 4391 static void l2cap_send_efs_conf_rsp(struct l2cap_chan *chan, void *data, 4392 u8 ident, u16 flags) 4393 { 4394 struct l2cap_conn *conn = chan->conn; 4395 4396 BT_DBG("conn %p chan %p ident %d flags 0x%4.4x", conn, chan, ident, 4397 flags); 4398 4399 clear_bit(CONF_LOC_CONF_PEND, &chan->conf_state); 4400 set_bit(CONF_OUTPUT_DONE, &chan->conf_state); 4401 4402 l2cap_send_cmd(conn, ident, L2CAP_CONF_RSP, 4403 l2cap_build_conf_rsp(chan, data, 4404 L2CAP_CONF_SUCCESS, flags), data); 4405 } 4406 4407 static void cmd_reject_invalid_cid(struct l2cap_conn *conn, u8 ident, 4408 u16 scid, u16 dcid) 4409 { 4410 struct l2cap_cmd_rej_cid rej; 4411 4412 rej.reason = cpu_to_le16(L2CAP_REJ_INVALID_CID); 4413 rej.scid = __cpu_to_le16(scid); 4414 rej.dcid = __cpu_to_le16(dcid); 4415 4416 l2cap_send_cmd(conn, ident, L2CAP_COMMAND_REJ, sizeof(rej), &rej); 4417 } 4418 4419 static inline int l2cap_config_req(struct l2cap_conn *conn, 4420 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4421 u8 *data) 4422 { 4423 struct l2cap_conf_req *req = (struct l2cap_conf_req *) data; 4424 u16 dcid, flags; 4425 u8 rsp[64]; 4426 struct l2cap_chan *chan; 4427 int len, err = 0; 4428 4429 if (cmd_len < sizeof(*req)) 4430 return -EPROTO; 4431 4432 dcid = __le16_to_cpu(req->dcid); 4433 flags = __le16_to_cpu(req->flags); 4434 4435 BT_DBG("dcid 0x%4.4x flags 0x%2.2x", dcid, flags); 4436 4437 chan = l2cap_get_chan_by_scid(conn, dcid); 4438 if (!chan) { 4439 cmd_reject_invalid_cid(conn, cmd->ident, dcid, 0); 4440 return 0; 4441 } 4442 4443 if (chan->state != BT_CONFIG && chan->state != BT_CONNECT2 && 4444 chan->state != BT_CONNECTED) { 4445 cmd_reject_invalid_cid(conn, cmd->ident, chan->scid, 4446 chan->dcid); 4447 goto unlock; 4448 } 4449 4450 /* Reject if config buffer is too small. */ 4451 len = cmd_len - sizeof(*req); 4452 if (chan->conf_len + len > sizeof(chan->conf_req)) { 4453 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP, 4454 l2cap_build_conf_rsp(chan, rsp, 4455 L2CAP_CONF_REJECT, flags), rsp); 4456 goto unlock; 4457 } 4458 4459 /* Store config. */ 4460 memcpy(chan->conf_req + chan->conf_len, req->data, len); 4461 chan->conf_len += len; 4462 4463 if (flags & L2CAP_CONF_FLAG_CONTINUATION) { 4464 /* Incomplete config. Send empty response. */ 4465 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP, 4466 l2cap_build_conf_rsp(chan, rsp, 4467 L2CAP_CONF_SUCCESS, flags), rsp); 4468 goto unlock; 4469 } 4470 4471 /* Complete config. */ 4472 len = l2cap_parse_conf_req(chan, rsp, sizeof(rsp)); 4473 if (len < 0) { 4474 l2cap_send_disconn_req(chan, ECONNRESET); 4475 goto unlock; 4476 } 4477 4478 chan->ident = cmd->ident; 4479 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP, len, rsp); 4480 if (chan->num_conf_rsp < L2CAP_CONF_MAX_CONF_RSP) 4481 chan->num_conf_rsp++; 4482 4483 /* Reset config buffer. */ 4484 chan->conf_len = 0; 4485 4486 if (!test_bit(CONF_OUTPUT_DONE, &chan->conf_state)) 4487 goto unlock; 4488 4489 if (test_bit(CONF_INPUT_DONE, &chan->conf_state)) { 4490 set_default_fcs(chan); 4491 4492 if (chan->mode == L2CAP_MODE_ERTM || 4493 chan->mode == L2CAP_MODE_STREAMING) 4494 err = l2cap_ertm_init(chan); 4495 4496 if (err < 0) 4497 l2cap_send_disconn_req(chan, -err); 4498 else 4499 l2cap_chan_ready(chan); 4500 4501 goto unlock; 4502 } 4503 4504 if (!test_and_set_bit(CONF_REQ_SENT, &chan->conf_state)) { 4505 u8 buf[64]; 4506 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ, 4507 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf); 4508 chan->num_conf_req++; 4509 } 4510 4511 /* Got Conf Rsp PENDING from remote side and assume we sent 4512 Conf Rsp PENDING in the code above */ 4513 if (test_bit(CONF_REM_CONF_PEND, &chan->conf_state) && 4514 test_bit(CONF_LOC_CONF_PEND, &chan->conf_state)) { 4515 4516 /* check compatibility */ 4517 4518 /* Send rsp for BR/EDR channel */ 4519 if (!chan->hs_hcon) 4520 l2cap_send_efs_conf_rsp(chan, rsp, cmd->ident, flags); 4521 else 4522 chan->ident = cmd->ident; 4523 } 4524 4525 unlock: 4526 l2cap_chan_unlock(chan); 4527 l2cap_chan_put(chan); 4528 return err; 4529 } 4530 4531 static inline int l2cap_config_rsp(struct l2cap_conn *conn, 4532 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4533 u8 *data) 4534 { 4535 struct l2cap_conf_rsp *rsp = (struct l2cap_conf_rsp *)data; 4536 u16 scid, flags, result; 4537 struct l2cap_chan *chan; 4538 int len = cmd_len - sizeof(*rsp); 4539 int err = 0; 4540 4541 if (cmd_len < sizeof(*rsp)) 4542 return -EPROTO; 4543 4544 scid = __le16_to_cpu(rsp->scid); 4545 flags = __le16_to_cpu(rsp->flags); 4546 result = __le16_to_cpu(rsp->result); 4547 4548 BT_DBG("scid 0x%4.4x flags 0x%2.2x result 0x%2.2x len %d", scid, flags, 4549 result, len); 4550 4551 chan = l2cap_get_chan_by_scid(conn, scid); 4552 if (!chan) 4553 return 0; 4554 4555 switch (result) { 4556 case L2CAP_CONF_SUCCESS: 4557 l2cap_conf_rfc_get(chan, rsp->data, len); 4558 clear_bit(CONF_REM_CONF_PEND, &chan->conf_state); 4559 break; 4560 4561 case L2CAP_CONF_PENDING: 4562 set_bit(CONF_REM_CONF_PEND, &chan->conf_state); 4563 4564 if (test_bit(CONF_LOC_CONF_PEND, &chan->conf_state)) { 4565 char buf[64]; 4566 4567 len = l2cap_parse_conf_rsp(chan, rsp->data, len, 4568 buf, sizeof(buf), &result); 4569 if (len < 0) { 4570 l2cap_send_disconn_req(chan, ECONNRESET); 4571 goto done; 4572 } 4573 4574 if (!chan->hs_hcon) { 4575 l2cap_send_efs_conf_rsp(chan, buf, cmd->ident, 4576 0); 4577 } else { 4578 if (l2cap_check_efs(chan)) { 4579 amp_create_logical_link(chan); 4580 chan->ident = cmd->ident; 4581 } 4582 } 4583 } 4584 goto done; 4585 4586 case L2CAP_CONF_UNKNOWN: 4587 case L2CAP_CONF_UNACCEPT: 4588 if (chan->num_conf_rsp <= L2CAP_CONF_MAX_CONF_RSP) { 4589 char req[64]; 4590 4591 if (len > sizeof(req) - sizeof(struct l2cap_conf_req)) { 4592 l2cap_send_disconn_req(chan, ECONNRESET); 4593 goto done; 4594 } 4595 4596 /* throw out any old stored conf requests */ 4597 result = L2CAP_CONF_SUCCESS; 4598 len = l2cap_parse_conf_rsp(chan, rsp->data, len, 4599 req, sizeof(req), &result); 4600 if (len < 0) { 4601 l2cap_send_disconn_req(chan, ECONNRESET); 4602 goto done; 4603 } 4604 4605 l2cap_send_cmd(conn, l2cap_get_ident(conn), 4606 L2CAP_CONF_REQ, len, req); 4607 chan->num_conf_req++; 4608 if (result != L2CAP_CONF_SUCCESS) 4609 goto done; 4610 break; 4611 } 4612 fallthrough; 4613 4614 default: 4615 l2cap_chan_set_err(chan, ECONNRESET); 4616 4617 __set_chan_timer(chan, L2CAP_DISC_REJ_TIMEOUT); 4618 l2cap_send_disconn_req(chan, ECONNRESET); 4619 goto done; 4620 } 4621 4622 if (flags & L2CAP_CONF_FLAG_CONTINUATION) 4623 goto done; 4624 4625 set_bit(CONF_INPUT_DONE, &chan->conf_state); 4626 4627 if (test_bit(CONF_OUTPUT_DONE, &chan->conf_state)) { 4628 set_default_fcs(chan); 4629 4630 if (chan->mode == L2CAP_MODE_ERTM || 4631 chan->mode == L2CAP_MODE_STREAMING) 4632 err = l2cap_ertm_init(chan); 4633 4634 if (err < 0) 4635 l2cap_send_disconn_req(chan, -err); 4636 else 4637 l2cap_chan_ready(chan); 4638 } 4639 4640 done: 4641 l2cap_chan_unlock(chan); 4642 l2cap_chan_put(chan); 4643 return err; 4644 } 4645 4646 static inline int l2cap_disconnect_req(struct l2cap_conn *conn, 4647 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4648 u8 *data) 4649 { 4650 struct l2cap_disconn_req *req = (struct l2cap_disconn_req *) data; 4651 struct l2cap_disconn_rsp rsp; 4652 u16 dcid, scid; 4653 struct l2cap_chan *chan; 4654 4655 if (cmd_len != sizeof(*req)) 4656 return -EPROTO; 4657 4658 scid = __le16_to_cpu(req->scid); 4659 dcid = __le16_to_cpu(req->dcid); 4660 4661 BT_DBG("scid 0x%4.4x dcid 0x%4.4x", scid, dcid); 4662 4663 chan = l2cap_get_chan_by_scid(conn, dcid); 4664 if (!chan) { 4665 cmd_reject_invalid_cid(conn, cmd->ident, dcid, scid); 4666 return 0; 4667 } 4668 4669 rsp.dcid = cpu_to_le16(chan->scid); 4670 rsp.scid = cpu_to_le16(chan->dcid); 4671 l2cap_send_cmd(conn, cmd->ident, L2CAP_DISCONN_RSP, sizeof(rsp), &rsp); 4672 4673 chan->ops->set_shutdown(chan); 4674 4675 l2cap_chan_unlock(chan); 4676 mutex_lock(&conn->chan_lock); 4677 l2cap_chan_lock(chan); 4678 l2cap_chan_del(chan, ECONNRESET); 4679 mutex_unlock(&conn->chan_lock); 4680 4681 chan->ops->close(chan); 4682 4683 l2cap_chan_unlock(chan); 4684 l2cap_chan_put(chan); 4685 4686 return 0; 4687 } 4688 4689 static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn, 4690 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4691 u8 *data) 4692 { 4693 struct l2cap_disconn_rsp *rsp = (struct l2cap_disconn_rsp *) data; 4694 u16 dcid, scid; 4695 struct l2cap_chan *chan; 4696 4697 if (cmd_len != sizeof(*rsp)) 4698 return -EPROTO; 4699 4700 scid = __le16_to_cpu(rsp->scid); 4701 dcid = __le16_to_cpu(rsp->dcid); 4702 4703 BT_DBG("dcid 0x%4.4x scid 0x%4.4x", dcid, scid); 4704 4705 chan = l2cap_get_chan_by_scid(conn, scid); 4706 if (!chan) { 4707 return 0; 4708 } 4709 4710 if (chan->state != BT_DISCONN) { 4711 l2cap_chan_unlock(chan); 4712 l2cap_chan_put(chan); 4713 return 0; 4714 } 4715 4716 l2cap_chan_unlock(chan); 4717 mutex_lock(&conn->chan_lock); 4718 l2cap_chan_lock(chan); 4719 l2cap_chan_del(chan, 0); 4720 mutex_unlock(&conn->chan_lock); 4721 4722 chan->ops->close(chan); 4723 4724 l2cap_chan_unlock(chan); 4725 l2cap_chan_put(chan); 4726 4727 return 0; 4728 } 4729 4730 static inline int l2cap_information_req(struct l2cap_conn *conn, 4731 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4732 u8 *data) 4733 { 4734 struct l2cap_info_req *req = (struct l2cap_info_req *) data; 4735 u16 type; 4736 4737 if (cmd_len != sizeof(*req)) 4738 return -EPROTO; 4739 4740 type = __le16_to_cpu(req->type); 4741 4742 BT_DBG("type 0x%4.4x", type); 4743 4744 if (type == L2CAP_IT_FEAT_MASK) { 4745 u8 buf[8]; 4746 u32 feat_mask = l2cap_feat_mask; 4747 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) buf; 4748 rsp->type = cpu_to_le16(L2CAP_IT_FEAT_MASK); 4749 rsp->result = cpu_to_le16(L2CAP_IR_SUCCESS); 4750 if (!disable_ertm) 4751 feat_mask |= L2CAP_FEAT_ERTM | L2CAP_FEAT_STREAMING 4752 | L2CAP_FEAT_FCS; 4753 if (conn->local_fixed_chan & L2CAP_FC_A2MP) 4754 feat_mask |= L2CAP_FEAT_EXT_FLOW 4755 | L2CAP_FEAT_EXT_WINDOW; 4756 4757 put_unaligned_le32(feat_mask, rsp->data); 4758 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(buf), 4759 buf); 4760 } else if (type == L2CAP_IT_FIXED_CHAN) { 4761 u8 buf[12]; 4762 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) buf; 4763 4764 rsp->type = cpu_to_le16(L2CAP_IT_FIXED_CHAN); 4765 rsp->result = cpu_to_le16(L2CAP_IR_SUCCESS); 4766 rsp->data[0] = conn->local_fixed_chan; 4767 memset(rsp->data + 1, 0, 7); 4768 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(buf), 4769 buf); 4770 } else { 4771 struct l2cap_info_rsp rsp; 4772 rsp.type = cpu_to_le16(type); 4773 rsp.result = cpu_to_le16(L2CAP_IR_NOTSUPP); 4774 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(rsp), 4775 &rsp); 4776 } 4777 4778 return 0; 4779 } 4780 4781 static inline int l2cap_information_rsp(struct l2cap_conn *conn, 4782 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4783 u8 *data) 4784 { 4785 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) data; 4786 u16 type, result; 4787 4788 if (cmd_len < sizeof(*rsp)) 4789 return -EPROTO; 4790 4791 type = __le16_to_cpu(rsp->type); 4792 result = __le16_to_cpu(rsp->result); 4793 4794 BT_DBG("type 0x%4.4x result 0x%2.2x", type, result); 4795 4796 /* L2CAP Info req/rsp are unbound to channels, add extra checks */ 4797 if (cmd->ident != conn->info_ident || 4798 conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE) 4799 return 0; 4800 4801 cancel_delayed_work(&conn->info_timer); 4802 4803 if (result != L2CAP_IR_SUCCESS) { 4804 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE; 4805 conn->info_ident = 0; 4806 4807 l2cap_conn_start(conn); 4808 4809 return 0; 4810 } 4811 4812 switch (type) { 4813 case L2CAP_IT_FEAT_MASK: 4814 conn->feat_mask = get_unaligned_le32(rsp->data); 4815 4816 if (conn->feat_mask & L2CAP_FEAT_FIXED_CHAN) { 4817 struct l2cap_info_req req; 4818 req.type = cpu_to_le16(L2CAP_IT_FIXED_CHAN); 4819 4820 conn->info_ident = l2cap_get_ident(conn); 4821 4822 l2cap_send_cmd(conn, conn->info_ident, 4823 L2CAP_INFO_REQ, sizeof(req), &req); 4824 } else { 4825 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE; 4826 conn->info_ident = 0; 4827 4828 l2cap_conn_start(conn); 4829 } 4830 break; 4831 4832 case L2CAP_IT_FIXED_CHAN: 4833 conn->remote_fixed_chan = rsp->data[0]; 4834 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE; 4835 conn->info_ident = 0; 4836 4837 l2cap_conn_start(conn); 4838 break; 4839 } 4840 4841 return 0; 4842 } 4843 4844 static int l2cap_create_channel_req(struct l2cap_conn *conn, 4845 struct l2cap_cmd_hdr *cmd, 4846 u16 cmd_len, void *data) 4847 { 4848 struct l2cap_create_chan_req *req = data; 4849 struct l2cap_create_chan_rsp rsp; 4850 struct l2cap_chan *chan; 4851 struct hci_dev *hdev; 4852 u16 psm, scid; 4853 4854 if (cmd_len != sizeof(*req)) 4855 return -EPROTO; 4856 4857 if (!(conn->local_fixed_chan & L2CAP_FC_A2MP)) 4858 return -EINVAL; 4859 4860 psm = le16_to_cpu(req->psm); 4861 scid = le16_to_cpu(req->scid); 4862 4863 BT_DBG("psm 0x%2.2x, scid 0x%4.4x, amp_id %d", psm, scid, req->amp_id); 4864 4865 /* For controller id 0 make BR/EDR connection */ 4866 if (req->amp_id == AMP_ID_BREDR) { 4867 l2cap_connect(conn, cmd, data, L2CAP_CREATE_CHAN_RSP, 4868 req->amp_id); 4869 return 0; 4870 } 4871 4872 /* Validate AMP controller id */ 4873 hdev = hci_dev_get(req->amp_id); 4874 if (!hdev) 4875 goto error; 4876 4877 if (hdev->dev_type != HCI_AMP || !test_bit(HCI_UP, &hdev->flags)) { 4878 hci_dev_put(hdev); 4879 goto error; 4880 } 4881 4882 chan = l2cap_connect(conn, cmd, data, L2CAP_CREATE_CHAN_RSP, 4883 req->amp_id); 4884 if (chan) { 4885 struct amp_mgr *mgr = conn->hcon->amp_mgr; 4886 struct hci_conn *hs_hcon; 4887 4888 hs_hcon = hci_conn_hash_lookup_ba(hdev, AMP_LINK, 4889 &conn->hcon->dst); 4890 if (!hs_hcon) { 4891 hci_dev_put(hdev); 4892 cmd_reject_invalid_cid(conn, cmd->ident, chan->scid, 4893 chan->dcid); 4894 return 0; 4895 } 4896 4897 BT_DBG("mgr %p bredr_chan %p hs_hcon %p", mgr, chan, hs_hcon); 4898 4899 mgr->bredr_chan = chan; 4900 chan->hs_hcon = hs_hcon; 4901 chan->fcs = L2CAP_FCS_NONE; 4902 conn->mtu = hdev->block_mtu; 4903 } 4904 4905 hci_dev_put(hdev); 4906 4907 return 0; 4908 4909 error: 4910 rsp.dcid = 0; 4911 rsp.scid = cpu_to_le16(scid); 4912 rsp.result = cpu_to_le16(L2CAP_CR_BAD_AMP); 4913 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO); 4914 4915 l2cap_send_cmd(conn, cmd->ident, L2CAP_CREATE_CHAN_RSP, 4916 sizeof(rsp), &rsp); 4917 4918 return 0; 4919 } 4920 4921 static void l2cap_send_move_chan_req(struct l2cap_chan *chan, u8 dest_amp_id) 4922 { 4923 struct l2cap_move_chan_req req; 4924 u8 ident; 4925 4926 BT_DBG("chan %p, dest_amp_id %d", chan, dest_amp_id); 4927 4928 ident = l2cap_get_ident(chan->conn); 4929 chan->ident = ident; 4930 4931 req.icid = cpu_to_le16(chan->scid); 4932 req.dest_amp_id = dest_amp_id; 4933 4934 l2cap_send_cmd(chan->conn, ident, L2CAP_MOVE_CHAN_REQ, sizeof(req), 4935 &req); 4936 4937 __set_chan_timer(chan, L2CAP_MOVE_TIMEOUT); 4938 } 4939 4940 static void l2cap_send_move_chan_rsp(struct l2cap_chan *chan, u16 result) 4941 { 4942 struct l2cap_move_chan_rsp rsp; 4943 4944 BT_DBG("chan %p, result 0x%4.4x", chan, result); 4945 4946 rsp.icid = cpu_to_le16(chan->dcid); 4947 rsp.result = cpu_to_le16(result); 4948 4949 l2cap_send_cmd(chan->conn, chan->ident, L2CAP_MOVE_CHAN_RSP, 4950 sizeof(rsp), &rsp); 4951 } 4952 4953 static void l2cap_send_move_chan_cfm(struct l2cap_chan *chan, u16 result) 4954 { 4955 struct l2cap_move_chan_cfm cfm; 4956 4957 BT_DBG("chan %p, result 0x%4.4x", chan, result); 4958 4959 chan->ident = l2cap_get_ident(chan->conn); 4960 4961 cfm.icid = cpu_to_le16(chan->scid); 4962 cfm.result = cpu_to_le16(result); 4963 4964 l2cap_send_cmd(chan->conn, chan->ident, L2CAP_MOVE_CHAN_CFM, 4965 sizeof(cfm), &cfm); 4966 4967 __set_chan_timer(chan, L2CAP_MOVE_TIMEOUT); 4968 } 4969 4970 static void l2cap_send_move_chan_cfm_icid(struct l2cap_conn *conn, u16 icid) 4971 { 4972 struct l2cap_move_chan_cfm cfm; 4973 4974 BT_DBG("conn %p, icid 0x%4.4x", conn, icid); 4975 4976 cfm.icid = cpu_to_le16(icid); 4977 cfm.result = cpu_to_le16(L2CAP_MC_UNCONFIRMED); 4978 4979 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_MOVE_CHAN_CFM, 4980 sizeof(cfm), &cfm); 4981 } 4982 4983 static void l2cap_send_move_chan_cfm_rsp(struct l2cap_conn *conn, u8 ident, 4984 u16 icid) 4985 { 4986 struct l2cap_move_chan_cfm_rsp rsp; 4987 4988 BT_DBG("icid 0x%4.4x", icid); 4989 4990 rsp.icid = cpu_to_le16(icid); 4991 l2cap_send_cmd(conn, ident, L2CAP_MOVE_CHAN_CFM_RSP, sizeof(rsp), &rsp); 4992 } 4993 4994 static void __release_logical_link(struct l2cap_chan *chan) 4995 { 4996 chan->hs_hchan = NULL; 4997 chan->hs_hcon = NULL; 4998 4999 /* Placeholder - release the logical link */ 5000 } 5001 5002 static void l2cap_logical_fail(struct l2cap_chan *chan) 5003 { 5004 /* Logical link setup failed */ 5005 if (chan->state != BT_CONNECTED) { 5006 /* Create channel failure, disconnect */ 5007 l2cap_send_disconn_req(chan, ECONNRESET); 5008 return; 5009 } 5010 5011 switch (chan->move_role) { 5012 case L2CAP_MOVE_ROLE_RESPONDER: 5013 l2cap_move_done(chan); 5014 l2cap_send_move_chan_rsp(chan, L2CAP_MR_NOT_SUPP); 5015 break; 5016 case L2CAP_MOVE_ROLE_INITIATOR: 5017 if (chan->move_state == L2CAP_MOVE_WAIT_LOGICAL_COMP || 5018 chan->move_state == L2CAP_MOVE_WAIT_LOGICAL_CFM) { 5019 /* Remote has only sent pending or 5020 * success responses, clean up 5021 */ 5022 l2cap_move_done(chan); 5023 } 5024 5025 /* Other amp move states imply that the move 5026 * has already aborted 5027 */ 5028 l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED); 5029 break; 5030 } 5031 } 5032 5033 static void l2cap_logical_finish_create(struct l2cap_chan *chan, 5034 struct hci_chan *hchan) 5035 { 5036 struct l2cap_conf_rsp rsp; 5037 5038 chan->hs_hchan = hchan; 5039 chan->hs_hcon->l2cap_data = chan->conn; 5040 5041 l2cap_send_efs_conf_rsp(chan, &rsp, chan->ident, 0); 5042 5043 if (test_bit(CONF_INPUT_DONE, &chan->conf_state)) { 5044 int err; 5045 5046 set_default_fcs(chan); 5047 5048 err = l2cap_ertm_init(chan); 5049 if (err < 0) 5050 l2cap_send_disconn_req(chan, -err); 5051 else 5052 l2cap_chan_ready(chan); 5053 } 5054 } 5055 5056 static void l2cap_logical_finish_move(struct l2cap_chan *chan, 5057 struct hci_chan *hchan) 5058 { 5059 chan->hs_hcon = hchan->conn; 5060 chan->hs_hcon->l2cap_data = chan->conn; 5061 5062 BT_DBG("move_state %d", chan->move_state); 5063 5064 switch (chan->move_state) { 5065 case L2CAP_MOVE_WAIT_LOGICAL_COMP: 5066 /* Move confirm will be sent after a success 5067 * response is received 5068 */ 5069 chan->move_state = L2CAP_MOVE_WAIT_RSP_SUCCESS; 5070 break; 5071 case L2CAP_MOVE_WAIT_LOGICAL_CFM: 5072 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) { 5073 chan->move_state = L2CAP_MOVE_WAIT_LOCAL_BUSY; 5074 } else if (chan->move_role == L2CAP_MOVE_ROLE_INITIATOR) { 5075 chan->move_state = L2CAP_MOVE_WAIT_CONFIRM_RSP; 5076 l2cap_send_move_chan_cfm(chan, L2CAP_MC_CONFIRMED); 5077 } else if (chan->move_role == L2CAP_MOVE_ROLE_RESPONDER) { 5078 chan->move_state = L2CAP_MOVE_WAIT_CONFIRM; 5079 l2cap_send_move_chan_rsp(chan, L2CAP_MR_SUCCESS); 5080 } 5081 break; 5082 default: 5083 /* Move was not in expected state, free the channel */ 5084 __release_logical_link(chan); 5085 5086 chan->move_state = L2CAP_MOVE_STABLE; 5087 } 5088 } 5089 5090 /* Call with chan locked */ 5091 void l2cap_logical_cfm(struct l2cap_chan *chan, struct hci_chan *hchan, 5092 u8 status) 5093 { 5094 BT_DBG("chan %p, hchan %p, status %d", chan, hchan, status); 5095 5096 if (status) { 5097 l2cap_logical_fail(chan); 5098 __release_logical_link(chan); 5099 return; 5100 } 5101 5102 if (chan->state != BT_CONNECTED) { 5103 /* Ignore logical link if channel is on BR/EDR */ 5104 if (chan->local_amp_id != AMP_ID_BREDR) 5105 l2cap_logical_finish_create(chan, hchan); 5106 } else { 5107 l2cap_logical_finish_move(chan, hchan); 5108 } 5109 } 5110 5111 void l2cap_move_start(struct l2cap_chan *chan) 5112 { 5113 BT_DBG("chan %p", chan); 5114 5115 if (chan->local_amp_id == AMP_ID_BREDR) { 5116 if (chan->chan_policy != BT_CHANNEL_POLICY_AMP_PREFERRED) 5117 return; 5118 chan->move_role = L2CAP_MOVE_ROLE_INITIATOR; 5119 chan->move_state = L2CAP_MOVE_WAIT_PREPARE; 5120 /* Placeholder - start physical link setup */ 5121 } else { 5122 chan->move_role = L2CAP_MOVE_ROLE_INITIATOR; 5123 chan->move_state = L2CAP_MOVE_WAIT_RSP_SUCCESS; 5124 chan->move_id = 0; 5125 l2cap_move_setup(chan); 5126 l2cap_send_move_chan_req(chan, 0); 5127 } 5128 } 5129 5130 static void l2cap_do_create(struct l2cap_chan *chan, int result, 5131 u8 local_amp_id, u8 remote_amp_id) 5132 { 5133 BT_DBG("chan %p state %s %u -> %u", chan, state_to_string(chan->state), 5134 local_amp_id, remote_amp_id); 5135 5136 chan->fcs = L2CAP_FCS_NONE; 5137 5138 /* Outgoing channel on AMP */ 5139 if (chan->state == BT_CONNECT) { 5140 if (result == L2CAP_CR_SUCCESS) { 5141 chan->local_amp_id = local_amp_id; 5142 l2cap_send_create_chan_req(chan, remote_amp_id); 5143 } else { 5144 /* Revert to BR/EDR connect */ 5145 l2cap_send_conn_req(chan); 5146 } 5147 5148 return; 5149 } 5150 5151 /* Incoming channel on AMP */ 5152 if (__l2cap_no_conn_pending(chan)) { 5153 struct l2cap_conn_rsp rsp; 5154 char buf[128]; 5155 rsp.scid = cpu_to_le16(chan->dcid); 5156 rsp.dcid = cpu_to_le16(chan->scid); 5157 5158 if (result == L2CAP_CR_SUCCESS) { 5159 /* Send successful response */ 5160 rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS); 5161 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO); 5162 } else { 5163 /* Send negative response */ 5164 rsp.result = cpu_to_le16(L2CAP_CR_NO_MEM); 5165 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO); 5166 } 5167 5168 l2cap_send_cmd(chan->conn, chan->ident, L2CAP_CREATE_CHAN_RSP, 5169 sizeof(rsp), &rsp); 5170 5171 if (result == L2CAP_CR_SUCCESS) { 5172 l2cap_state_change(chan, BT_CONFIG); 5173 set_bit(CONF_REQ_SENT, &chan->conf_state); 5174 l2cap_send_cmd(chan->conn, l2cap_get_ident(chan->conn), 5175 L2CAP_CONF_REQ, 5176 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf); 5177 chan->num_conf_req++; 5178 } 5179 } 5180 } 5181 5182 static void l2cap_do_move_initiate(struct l2cap_chan *chan, u8 local_amp_id, 5183 u8 remote_amp_id) 5184 { 5185 l2cap_move_setup(chan); 5186 chan->move_id = local_amp_id; 5187 chan->move_state = L2CAP_MOVE_WAIT_RSP; 5188 5189 l2cap_send_move_chan_req(chan, remote_amp_id); 5190 } 5191 5192 static void l2cap_do_move_respond(struct l2cap_chan *chan, int result) 5193 { 5194 struct hci_chan *hchan = NULL; 5195 5196 /* Placeholder - get hci_chan for logical link */ 5197 5198 if (hchan) { 5199 if (hchan->state == BT_CONNECTED) { 5200 /* Logical link is ready to go */ 5201 chan->hs_hcon = hchan->conn; 5202 chan->hs_hcon->l2cap_data = chan->conn; 5203 chan->move_state = L2CAP_MOVE_WAIT_CONFIRM; 5204 l2cap_send_move_chan_rsp(chan, L2CAP_MR_SUCCESS); 5205 5206 l2cap_logical_cfm(chan, hchan, L2CAP_MR_SUCCESS); 5207 } else { 5208 /* Wait for logical link to be ready */ 5209 chan->move_state = L2CAP_MOVE_WAIT_LOGICAL_CFM; 5210 } 5211 } else { 5212 /* Logical link not available */ 5213 l2cap_send_move_chan_rsp(chan, L2CAP_MR_NOT_ALLOWED); 5214 } 5215 } 5216 5217 static void l2cap_do_move_cancel(struct l2cap_chan *chan, int result) 5218 { 5219 if (chan->move_role == L2CAP_MOVE_ROLE_RESPONDER) { 5220 u8 rsp_result; 5221 if (result == -EINVAL) 5222 rsp_result = L2CAP_MR_BAD_ID; 5223 else 5224 rsp_result = L2CAP_MR_NOT_ALLOWED; 5225 5226 l2cap_send_move_chan_rsp(chan, rsp_result); 5227 } 5228 5229 chan->move_role = L2CAP_MOVE_ROLE_NONE; 5230 chan->move_state = L2CAP_MOVE_STABLE; 5231 5232 /* Restart data transmission */ 5233 l2cap_ertm_send(chan); 5234 } 5235 5236 /* Invoke with locked chan */ 5237 void __l2cap_physical_cfm(struct l2cap_chan *chan, int result) 5238 { 5239 u8 local_amp_id = chan->local_amp_id; 5240 u8 remote_amp_id = chan->remote_amp_id; 5241 5242 BT_DBG("chan %p, result %d, local_amp_id %d, remote_amp_id %d", 5243 chan, result, local_amp_id, remote_amp_id); 5244 5245 if (chan->state == BT_DISCONN || chan->state == BT_CLOSED) 5246 return; 5247 5248 if (chan->state != BT_CONNECTED) { 5249 l2cap_do_create(chan, result, local_amp_id, remote_amp_id); 5250 } else if (result != L2CAP_MR_SUCCESS) { 5251 l2cap_do_move_cancel(chan, result); 5252 } else { 5253 switch (chan->move_role) { 5254 case L2CAP_MOVE_ROLE_INITIATOR: 5255 l2cap_do_move_initiate(chan, local_amp_id, 5256 remote_amp_id); 5257 break; 5258 case L2CAP_MOVE_ROLE_RESPONDER: 5259 l2cap_do_move_respond(chan, result); 5260 break; 5261 default: 5262 l2cap_do_move_cancel(chan, result); 5263 break; 5264 } 5265 } 5266 } 5267 5268 static inline int l2cap_move_channel_req(struct l2cap_conn *conn, 5269 struct l2cap_cmd_hdr *cmd, 5270 u16 cmd_len, void *data) 5271 { 5272 struct l2cap_move_chan_req *req = data; 5273 struct l2cap_move_chan_rsp rsp; 5274 struct l2cap_chan *chan; 5275 u16 icid = 0; 5276 u16 result = L2CAP_MR_NOT_ALLOWED; 5277 5278 if (cmd_len != sizeof(*req)) 5279 return -EPROTO; 5280 5281 icid = le16_to_cpu(req->icid); 5282 5283 BT_DBG("icid 0x%4.4x, dest_amp_id %d", icid, req->dest_amp_id); 5284 5285 if (!(conn->local_fixed_chan & L2CAP_FC_A2MP)) 5286 return -EINVAL; 5287 5288 chan = l2cap_get_chan_by_dcid(conn, icid); 5289 if (!chan) { 5290 rsp.icid = cpu_to_le16(icid); 5291 rsp.result = cpu_to_le16(L2CAP_MR_NOT_ALLOWED); 5292 l2cap_send_cmd(conn, cmd->ident, L2CAP_MOVE_CHAN_RSP, 5293 sizeof(rsp), &rsp); 5294 return 0; 5295 } 5296 5297 chan->ident = cmd->ident; 5298 5299 if (chan->scid < L2CAP_CID_DYN_START || 5300 chan->chan_policy == BT_CHANNEL_POLICY_BREDR_ONLY || 5301 (chan->mode != L2CAP_MODE_ERTM && 5302 chan->mode != L2CAP_MODE_STREAMING)) { 5303 result = L2CAP_MR_NOT_ALLOWED; 5304 goto send_move_response; 5305 } 5306 5307 if (chan->local_amp_id == req->dest_amp_id) { 5308 result = L2CAP_MR_SAME_ID; 5309 goto send_move_response; 5310 } 5311 5312 if (req->dest_amp_id != AMP_ID_BREDR) { 5313 struct hci_dev *hdev; 5314 hdev = hci_dev_get(req->dest_amp_id); 5315 if (!hdev || hdev->dev_type != HCI_AMP || 5316 !test_bit(HCI_UP, &hdev->flags)) { 5317 if (hdev) 5318 hci_dev_put(hdev); 5319 5320 result = L2CAP_MR_BAD_ID; 5321 goto send_move_response; 5322 } 5323 hci_dev_put(hdev); 5324 } 5325 5326 /* Detect a move collision. Only send a collision response 5327 * if this side has "lost", otherwise proceed with the move. 5328 * The winner has the larger bd_addr. 5329 */ 5330 if ((__chan_is_moving(chan) || 5331 chan->move_role != L2CAP_MOVE_ROLE_NONE) && 5332 bacmp(&conn->hcon->src, &conn->hcon->dst) > 0) { 5333 result = L2CAP_MR_COLLISION; 5334 goto send_move_response; 5335 } 5336 5337 chan->move_role = L2CAP_MOVE_ROLE_RESPONDER; 5338 l2cap_move_setup(chan); 5339 chan->move_id = req->dest_amp_id; 5340 5341 if (req->dest_amp_id == AMP_ID_BREDR) { 5342 /* Moving to BR/EDR */ 5343 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) { 5344 chan->move_state = L2CAP_MOVE_WAIT_LOCAL_BUSY; 5345 result = L2CAP_MR_PEND; 5346 } else { 5347 chan->move_state = L2CAP_MOVE_WAIT_CONFIRM; 5348 result = L2CAP_MR_SUCCESS; 5349 } 5350 } else { 5351 chan->move_state = L2CAP_MOVE_WAIT_PREPARE; 5352 /* Placeholder - uncomment when amp functions are available */ 5353 /*amp_accept_physical(chan, req->dest_amp_id);*/ 5354 result = L2CAP_MR_PEND; 5355 } 5356 5357 send_move_response: 5358 l2cap_send_move_chan_rsp(chan, result); 5359 5360 l2cap_chan_unlock(chan); 5361 l2cap_chan_put(chan); 5362 5363 return 0; 5364 } 5365 5366 static void l2cap_move_continue(struct l2cap_conn *conn, u16 icid, u16 result) 5367 { 5368 struct l2cap_chan *chan; 5369 struct hci_chan *hchan = NULL; 5370 5371 chan = l2cap_get_chan_by_scid(conn, icid); 5372 if (!chan) { 5373 l2cap_send_move_chan_cfm_icid(conn, icid); 5374 return; 5375 } 5376 5377 __clear_chan_timer(chan); 5378 if (result == L2CAP_MR_PEND) 5379 __set_chan_timer(chan, L2CAP_MOVE_ERTX_TIMEOUT); 5380 5381 switch (chan->move_state) { 5382 case L2CAP_MOVE_WAIT_LOGICAL_COMP: 5383 /* Move confirm will be sent when logical link 5384 * is complete. 5385 */ 5386 chan->move_state = L2CAP_MOVE_WAIT_LOGICAL_CFM; 5387 break; 5388 case L2CAP_MOVE_WAIT_RSP_SUCCESS: 5389 if (result == L2CAP_MR_PEND) { 5390 break; 5391 } else if (test_bit(CONN_LOCAL_BUSY, 5392 &chan->conn_state)) { 5393 chan->move_state = L2CAP_MOVE_WAIT_LOCAL_BUSY; 5394 } else { 5395 /* Logical link is up or moving to BR/EDR, 5396 * proceed with move 5397 */ 5398 chan->move_state = L2CAP_MOVE_WAIT_CONFIRM_RSP; 5399 l2cap_send_move_chan_cfm(chan, L2CAP_MC_CONFIRMED); 5400 } 5401 break; 5402 case L2CAP_MOVE_WAIT_RSP: 5403 /* Moving to AMP */ 5404 if (result == L2CAP_MR_SUCCESS) { 5405 /* Remote is ready, send confirm immediately 5406 * after logical link is ready 5407 */ 5408 chan->move_state = L2CAP_MOVE_WAIT_LOGICAL_CFM; 5409 } else { 5410 /* Both logical link and move success 5411 * are required to confirm 5412 */ 5413 chan->move_state = L2CAP_MOVE_WAIT_LOGICAL_COMP; 5414 } 5415 5416 /* Placeholder - get hci_chan for logical link */ 5417 if (!hchan) { 5418 /* Logical link not available */ 5419 l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED); 5420 break; 5421 } 5422 5423 /* If the logical link is not yet connected, do not 5424 * send confirmation. 5425 */ 5426 if (hchan->state != BT_CONNECTED) 5427 break; 5428 5429 /* Logical link is already ready to go */ 5430 5431 chan->hs_hcon = hchan->conn; 5432 chan->hs_hcon->l2cap_data = chan->conn; 5433 5434 if (result == L2CAP_MR_SUCCESS) { 5435 /* Can confirm now */ 5436 l2cap_send_move_chan_cfm(chan, L2CAP_MC_CONFIRMED); 5437 } else { 5438 /* Now only need move success 5439 * to confirm 5440 */ 5441 chan->move_state = L2CAP_MOVE_WAIT_RSP_SUCCESS; 5442 } 5443 5444 l2cap_logical_cfm(chan, hchan, L2CAP_MR_SUCCESS); 5445 break; 5446 default: 5447 /* Any other amp move state means the move failed. */ 5448 chan->move_id = chan->local_amp_id; 5449 l2cap_move_done(chan); 5450 l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED); 5451 } 5452 5453 l2cap_chan_unlock(chan); 5454 l2cap_chan_put(chan); 5455 } 5456 5457 static void l2cap_move_fail(struct l2cap_conn *conn, u8 ident, u16 icid, 5458 u16 result) 5459 { 5460 struct l2cap_chan *chan; 5461 5462 chan = l2cap_get_chan_by_ident(conn, ident); 5463 if (!chan) { 5464 /* Could not locate channel, icid is best guess */ 5465 l2cap_send_move_chan_cfm_icid(conn, icid); 5466 return; 5467 } 5468 5469 __clear_chan_timer(chan); 5470 5471 if (chan->move_role == L2CAP_MOVE_ROLE_INITIATOR) { 5472 if (result == L2CAP_MR_COLLISION) { 5473 chan->move_role = L2CAP_MOVE_ROLE_RESPONDER; 5474 } else { 5475 /* Cleanup - cancel move */ 5476 chan->move_id = chan->local_amp_id; 5477 l2cap_move_done(chan); 5478 } 5479 } 5480 5481 l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED); 5482 5483 l2cap_chan_unlock(chan); 5484 l2cap_chan_put(chan); 5485 } 5486 5487 static int l2cap_move_channel_rsp(struct l2cap_conn *conn, 5488 struct l2cap_cmd_hdr *cmd, 5489 u16 cmd_len, void *data) 5490 { 5491 struct l2cap_move_chan_rsp *rsp = data; 5492 u16 icid, result; 5493 5494 if (cmd_len != sizeof(*rsp)) 5495 return -EPROTO; 5496 5497 icid = le16_to_cpu(rsp->icid); 5498 result = le16_to_cpu(rsp->result); 5499 5500 BT_DBG("icid 0x%4.4x, result 0x%4.4x", icid, result); 5501 5502 if (result == L2CAP_MR_SUCCESS || result == L2CAP_MR_PEND) 5503 l2cap_move_continue(conn, icid, result); 5504 else 5505 l2cap_move_fail(conn, cmd->ident, icid, result); 5506 5507 return 0; 5508 } 5509 5510 static int l2cap_move_channel_confirm(struct l2cap_conn *conn, 5511 struct l2cap_cmd_hdr *cmd, 5512 u16 cmd_len, void *data) 5513 { 5514 struct l2cap_move_chan_cfm *cfm = data; 5515 struct l2cap_chan *chan; 5516 u16 icid, result; 5517 5518 if (cmd_len != sizeof(*cfm)) 5519 return -EPROTO; 5520 5521 icid = le16_to_cpu(cfm->icid); 5522 result = le16_to_cpu(cfm->result); 5523 5524 BT_DBG("icid 0x%4.4x, result 0x%4.4x", icid, result); 5525 5526 chan = l2cap_get_chan_by_dcid(conn, icid); 5527 if (!chan) { 5528 /* Spec requires a response even if the icid was not found */ 5529 l2cap_send_move_chan_cfm_rsp(conn, cmd->ident, icid); 5530 return 0; 5531 } 5532 5533 if (chan->move_state == L2CAP_MOVE_WAIT_CONFIRM) { 5534 if (result == L2CAP_MC_CONFIRMED) { 5535 chan->local_amp_id = chan->move_id; 5536 if (chan->local_amp_id == AMP_ID_BREDR) 5537 __release_logical_link(chan); 5538 } else { 5539 chan->move_id = chan->local_amp_id; 5540 } 5541 5542 l2cap_move_done(chan); 5543 } 5544 5545 l2cap_send_move_chan_cfm_rsp(conn, cmd->ident, icid); 5546 5547 l2cap_chan_unlock(chan); 5548 l2cap_chan_put(chan); 5549 5550 return 0; 5551 } 5552 5553 static inline int l2cap_move_channel_confirm_rsp(struct l2cap_conn *conn, 5554 struct l2cap_cmd_hdr *cmd, 5555 u16 cmd_len, void *data) 5556 { 5557 struct l2cap_move_chan_cfm_rsp *rsp = data; 5558 struct l2cap_chan *chan; 5559 u16 icid; 5560 5561 if (cmd_len != sizeof(*rsp)) 5562 return -EPROTO; 5563 5564 icid = le16_to_cpu(rsp->icid); 5565 5566 BT_DBG("icid 0x%4.4x", icid); 5567 5568 chan = l2cap_get_chan_by_scid(conn, icid); 5569 if (!chan) 5570 return 0; 5571 5572 __clear_chan_timer(chan); 5573 5574 if (chan->move_state == L2CAP_MOVE_WAIT_CONFIRM_RSP) { 5575 chan->local_amp_id = chan->move_id; 5576 5577 if (chan->local_amp_id == AMP_ID_BREDR && chan->hs_hchan) 5578 __release_logical_link(chan); 5579 5580 l2cap_move_done(chan); 5581 } 5582 5583 l2cap_chan_unlock(chan); 5584 l2cap_chan_put(chan); 5585 5586 return 0; 5587 } 5588 5589 static inline int l2cap_conn_param_update_req(struct l2cap_conn *conn, 5590 struct l2cap_cmd_hdr *cmd, 5591 u16 cmd_len, u8 *data) 5592 { 5593 struct hci_conn *hcon = conn->hcon; 5594 struct l2cap_conn_param_update_req *req; 5595 struct l2cap_conn_param_update_rsp rsp; 5596 u16 min, max, latency, to_multiplier; 5597 int err; 5598 5599 if (hcon->role != HCI_ROLE_MASTER) 5600 return -EINVAL; 5601 5602 if (cmd_len != sizeof(struct l2cap_conn_param_update_req)) 5603 return -EPROTO; 5604 5605 req = (struct l2cap_conn_param_update_req *) data; 5606 min = __le16_to_cpu(req->min); 5607 max = __le16_to_cpu(req->max); 5608 latency = __le16_to_cpu(req->latency); 5609 to_multiplier = __le16_to_cpu(req->to_multiplier); 5610 5611 BT_DBG("min 0x%4.4x max 0x%4.4x latency: 0x%4.4x Timeout: 0x%4.4x", 5612 min, max, latency, to_multiplier); 5613 5614 memset(&rsp, 0, sizeof(rsp)); 5615 5616 err = hci_check_conn_params(min, max, latency, to_multiplier); 5617 if (err) 5618 rsp.result = cpu_to_le16(L2CAP_CONN_PARAM_REJECTED); 5619 else 5620 rsp.result = cpu_to_le16(L2CAP_CONN_PARAM_ACCEPTED); 5621 5622 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONN_PARAM_UPDATE_RSP, 5623 sizeof(rsp), &rsp); 5624 5625 if (!err) { 5626 u8 store_hint; 5627 5628 store_hint = hci_le_conn_update(hcon, min, max, latency, 5629 to_multiplier); 5630 mgmt_new_conn_param(hcon->hdev, &hcon->dst, hcon->dst_type, 5631 store_hint, min, max, latency, 5632 to_multiplier); 5633 5634 } 5635 5636 return 0; 5637 } 5638 5639 static int l2cap_le_connect_rsp(struct l2cap_conn *conn, 5640 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 5641 u8 *data) 5642 { 5643 struct l2cap_le_conn_rsp *rsp = (struct l2cap_le_conn_rsp *) data; 5644 struct hci_conn *hcon = conn->hcon; 5645 u16 dcid, mtu, mps, credits, result; 5646 struct l2cap_chan *chan; 5647 int err, sec_level; 5648 5649 if (cmd_len < sizeof(*rsp)) 5650 return -EPROTO; 5651 5652 dcid = __le16_to_cpu(rsp->dcid); 5653 mtu = __le16_to_cpu(rsp->mtu); 5654 mps = __le16_to_cpu(rsp->mps); 5655 credits = __le16_to_cpu(rsp->credits); 5656 result = __le16_to_cpu(rsp->result); 5657 5658 if (result == L2CAP_CR_LE_SUCCESS && (mtu < 23 || mps < 23 || 5659 dcid < L2CAP_CID_DYN_START || 5660 dcid > L2CAP_CID_LE_DYN_END)) 5661 return -EPROTO; 5662 5663 BT_DBG("dcid 0x%4.4x mtu %u mps %u credits %u result 0x%2.2x", 5664 dcid, mtu, mps, credits, result); 5665 5666 mutex_lock(&conn->chan_lock); 5667 5668 chan = __l2cap_get_chan_by_ident(conn, cmd->ident); 5669 if (!chan) { 5670 err = -EBADSLT; 5671 goto unlock; 5672 } 5673 5674 err = 0; 5675 5676 l2cap_chan_lock(chan); 5677 5678 switch (result) { 5679 case L2CAP_CR_LE_SUCCESS: 5680 if (__l2cap_get_chan_by_dcid(conn, dcid)) { 5681 err = -EBADSLT; 5682 break; 5683 } 5684 5685 chan->ident = 0; 5686 chan->dcid = dcid; 5687 chan->omtu = mtu; 5688 chan->remote_mps = mps; 5689 chan->tx_credits = credits; 5690 l2cap_chan_ready(chan); 5691 break; 5692 5693 case L2CAP_CR_LE_AUTHENTICATION: 5694 case L2CAP_CR_LE_ENCRYPTION: 5695 /* If we already have MITM protection we can't do 5696 * anything. 5697 */ 5698 if (hcon->sec_level > BT_SECURITY_MEDIUM) { 5699 l2cap_chan_del(chan, ECONNREFUSED); 5700 break; 5701 } 5702 5703 sec_level = hcon->sec_level + 1; 5704 if (chan->sec_level < sec_level) 5705 chan->sec_level = sec_level; 5706 5707 /* We'll need to send a new Connect Request */ 5708 clear_bit(FLAG_LE_CONN_REQ_SENT, &chan->flags); 5709 5710 smp_conn_security(hcon, chan->sec_level); 5711 break; 5712 5713 default: 5714 l2cap_chan_del(chan, ECONNREFUSED); 5715 break; 5716 } 5717 5718 l2cap_chan_unlock(chan); 5719 5720 unlock: 5721 mutex_unlock(&conn->chan_lock); 5722 5723 return err; 5724 } 5725 5726 static inline int l2cap_bredr_sig_cmd(struct l2cap_conn *conn, 5727 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 5728 u8 *data) 5729 { 5730 int err = 0; 5731 5732 switch (cmd->code) { 5733 case L2CAP_COMMAND_REJ: 5734 l2cap_command_rej(conn, cmd, cmd_len, data); 5735 break; 5736 5737 case L2CAP_CONN_REQ: 5738 err = l2cap_connect_req(conn, cmd, cmd_len, data); 5739 break; 5740 5741 case L2CAP_CONN_RSP: 5742 case L2CAP_CREATE_CHAN_RSP: 5743 l2cap_connect_create_rsp(conn, cmd, cmd_len, data); 5744 break; 5745 5746 case L2CAP_CONF_REQ: 5747 err = l2cap_config_req(conn, cmd, cmd_len, data); 5748 break; 5749 5750 case L2CAP_CONF_RSP: 5751 l2cap_config_rsp(conn, cmd, cmd_len, data); 5752 break; 5753 5754 case L2CAP_DISCONN_REQ: 5755 err = l2cap_disconnect_req(conn, cmd, cmd_len, data); 5756 break; 5757 5758 case L2CAP_DISCONN_RSP: 5759 l2cap_disconnect_rsp(conn, cmd, cmd_len, data); 5760 break; 5761 5762 case L2CAP_ECHO_REQ: 5763 l2cap_send_cmd(conn, cmd->ident, L2CAP_ECHO_RSP, cmd_len, data); 5764 break; 5765 5766 case L2CAP_ECHO_RSP: 5767 break; 5768 5769 case L2CAP_INFO_REQ: 5770 err = l2cap_information_req(conn, cmd, cmd_len, data); 5771 break; 5772 5773 case L2CAP_INFO_RSP: 5774 l2cap_information_rsp(conn, cmd, cmd_len, data); 5775 break; 5776 5777 case L2CAP_CREATE_CHAN_REQ: 5778 err = l2cap_create_channel_req(conn, cmd, cmd_len, data); 5779 break; 5780 5781 case L2CAP_MOVE_CHAN_REQ: 5782 err = l2cap_move_channel_req(conn, cmd, cmd_len, data); 5783 break; 5784 5785 case L2CAP_MOVE_CHAN_RSP: 5786 l2cap_move_channel_rsp(conn, cmd, cmd_len, data); 5787 break; 5788 5789 case L2CAP_MOVE_CHAN_CFM: 5790 err = l2cap_move_channel_confirm(conn, cmd, cmd_len, data); 5791 break; 5792 5793 case L2CAP_MOVE_CHAN_CFM_RSP: 5794 l2cap_move_channel_confirm_rsp(conn, cmd, cmd_len, data); 5795 break; 5796 5797 default: 5798 BT_ERR("Unknown BR/EDR signaling command 0x%2.2x", cmd->code); 5799 err = -EINVAL; 5800 break; 5801 } 5802 5803 return err; 5804 } 5805 5806 static int l2cap_le_connect_req(struct l2cap_conn *conn, 5807 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 5808 u8 *data) 5809 { 5810 struct l2cap_le_conn_req *req = (struct l2cap_le_conn_req *) data; 5811 struct l2cap_le_conn_rsp rsp; 5812 struct l2cap_chan *chan, *pchan; 5813 u16 dcid, scid, credits, mtu, mps; 5814 __le16 psm; 5815 u8 result; 5816 5817 if (cmd_len != sizeof(*req)) 5818 return -EPROTO; 5819 5820 scid = __le16_to_cpu(req->scid); 5821 mtu = __le16_to_cpu(req->mtu); 5822 mps = __le16_to_cpu(req->mps); 5823 psm = req->psm; 5824 dcid = 0; 5825 credits = 0; 5826 5827 if (mtu < 23 || mps < 23) 5828 return -EPROTO; 5829 5830 BT_DBG("psm 0x%2.2x scid 0x%4.4x mtu %u mps %u", __le16_to_cpu(psm), 5831 scid, mtu, mps); 5832 5833 /* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A 5834 * page 1059: 5835 * 5836 * Valid range: 0x0001-0x00ff 5837 * 5838 * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges 5839 */ 5840 if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) { 5841 result = L2CAP_CR_LE_BAD_PSM; 5842 chan = NULL; 5843 goto response; 5844 } 5845 5846 /* Check if we have socket listening on psm */ 5847 pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src, 5848 &conn->hcon->dst, LE_LINK); 5849 if (!pchan) { 5850 result = L2CAP_CR_LE_BAD_PSM; 5851 chan = NULL; 5852 goto response; 5853 } 5854 5855 mutex_lock(&conn->chan_lock); 5856 l2cap_chan_lock(pchan); 5857 5858 if (!smp_sufficient_security(conn->hcon, pchan->sec_level, 5859 SMP_ALLOW_STK)) { 5860 result = L2CAP_CR_LE_AUTHENTICATION; 5861 chan = NULL; 5862 goto response_unlock; 5863 } 5864 5865 /* Check for valid dynamic CID range */ 5866 if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_LE_DYN_END) { 5867 result = L2CAP_CR_LE_INVALID_SCID; 5868 chan = NULL; 5869 goto response_unlock; 5870 } 5871 5872 /* Check if we already have channel with that dcid */ 5873 if (__l2cap_get_chan_by_dcid(conn, scid)) { 5874 result = L2CAP_CR_LE_SCID_IN_USE; 5875 chan = NULL; 5876 goto response_unlock; 5877 } 5878 5879 chan = pchan->ops->new_connection(pchan); 5880 if (!chan) { 5881 result = L2CAP_CR_LE_NO_MEM; 5882 goto response_unlock; 5883 } 5884 5885 bacpy(&chan->src, &conn->hcon->src); 5886 bacpy(&chan->dst, &conn->hcon->dst); 5887 chan->src_type = bdaddr_src_type(conn->hcon); 5888 chan->dst_type = bdaddr_dst_type(conn->hcon); 5889 chan->psm = psm; 5890 chan->dcid = scid; 5891 chan->omtu = mtu; 5892 chan->remote_mps = mps; 5893 5894 __l2cap_chan_add(conn, chan); 5895 5896 l2cap_le_flowctl_init(chan, __le16_to_cpu(req->credits)); 5897 5898 dcid = chan->scid; 5899 credits = chan->rx_credits; 5900 5901 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan)); 5902 5903 chan->ident = cmd->ident; 5904 5905 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) { 5906 l2cap_state_change(chan, BT_CONNECT2); 5907 /* The following result value is actually not defined 5908 * for LE CoC but we use it to let the function know 5909 * that it should bail out after doing its cleanup 5910 * instead of sending a response. 5911 */ 5912 result = L2CAP_CR_PEND; 5913 chan->ops->defer(chan); 5914 } else { 5915 l2cap_chan_ready(chan); 5916 result = L2CAP_CR_LE_SUCCESS; 5917 } 5918 5919 response_unlock: 5920 l2cap_chan_unlock(pchan); 5921 mutex_unlock(&conn->chan_lock); 5922 l2cap_chan_put(pchan); 5923 5924 if (result == L2CAP_CR_PEND) 5925 return 0; 5926 5927 response: 5928 if (chan) { 5929 rsp.mtu = cpu_to_le16(chan->imtu); 5930 rsp.mps = cpu_to_le16(chan->mps); 5931 } else { 5932 rsp.mtu = 0; 5933 rsp.mps = 0; 5934 } 5935 5936 rsp.dcid = cpu_to_le16(dcid); 5937 rsp.credits = cpu_to_le16(credits); 5938 rsp.result = cpu_to_le16(result); 5939 5940 l2cap_send_cmd(conn, cmd->ident, L2CAP_LE_CONN_RSP, sizeof(rsp), &rsp); 5941 5942 return 0; 5943 } 5944 5945 static inline int l2cap_le_credits(struct l2cap_conn *conn, 5946 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 5947 u8 *data) 5948 { 5949 struct l2cap_le_credits *pkt; 5950 struct l2cap_chan *chan; 5951 u16 cid, credits, max_credits; 5952 5953 if (cmd_len != sizeof(*pkt)) 5954 return -EPROTO; 5955 5956 pkt = (struct l2cap_le_credits *) data; 5957 cid = __le16_to_cpu(pkt->cid); 5958 credits = __le16_to_cpu(pkt->credits); 5959 5960 BT_DBG("cid 0x%4.4x credits 0x%4.4x", cid, credits); 5961 5962 chan = l2cap_get_chan_by_dcid(conn, cid); 5963 if (!chan) 5964 return -EBADSLT; 5965 5966 max_credits = LE_FLOWCTL_MAX_CREDITS - chan->tx_credits; 5967 if (credits > max_credits) { 5968 BT_ERR("LE credits overflow"); 5969 l2cap_send_disconn_req(chan, ECONNRESET); 5970 5971 /* Return 0 so that we don't trigger an unnecessary 5972 * command reject packet. 5973 */ 5974 goto unlock; 5975 } 5976 5977 chan->tx_credits += credits; 5978 5979 /* Resume sending */ 5980 l2cap_le_flowctl_send(chan); 5981 5982 if (chan->tx_credits) 5983 chan->ops->resume(chan); 5984 5985 unlock: 5986 l2cap_chan_unlock(chan); 5987 l2cap_chan_put(chan); 5988 5989 return 0; 5990 } 5991 5992 static inline int l2cap_ecred_conn_req(struct l2cap_conn *conn, 5993 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 5994 u8 *data) 5995 { 5996 struct l2cap_ecred_conn_req *req = (void *) data; 5997 struct { 5998 struct l2cap_ecred_conn_rsp rsp; 5999 __le16 dcid[L2CAP_ECRED_MAX_CID]; 6000 } __packed pdu; 6001 struct l2cap_chan *chan, *pchan; 6002 u16 mtu, mps; 6003 __le16 psm; 6004 u8 result, len = 0; 6005 int i, num_scid; 6006 bool defer = false; 6007 6008 if (!enable_ecred) 6009 return -EINVAL; 6010 6011 if (cmd_len < sizeof(*req) || (cmd_len - sizeof(*req)) % sizeof(u16)) { 6012 result = L2CAP_CR_LE_INVALID_PARAMS; 6013 goto response; 6014 } 6015 6016 cmd_len -= sizeof(*req); 6017 num_scid = cmd_len / sizeof(u16); 6018 6019 if (num_scid > ARRAY_SIZE(pdu.dcid)) { 6020 result = L2CAP_CR_LE_INVALID_PARAMS; 6021 goto response; 6022 } 6023 6024 mtu = __le16_to_cpu(req->mtu); 6025 mps = __le16_to_cpu(req->mps); 6026 6027 if (mtu < L2CAP_ECRED_MIN_MTU || mps < L2CAP_ECRED_MIN_MPS) { 6028 result = L2CAP_CR_LE_UNACCEPT_PARAMS; 6029 goto response; 6030 } 6031 6032 psm = req->psm; 6033 6034 /* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A 6035 * page 1059: 6036 * 6037 * Valid range: 0x0001-0x00ff 6038 * 6039 * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges 6040 */ 6041 if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) { 6042 result = L2CAP_CR_LE_BAD_PSM; 6043 goto response; 6044 } 6045 6046 BT_DBG("psm 0x%2.2x mtu %u mps %u", __le16_to_cpu(psm), mtu, mps); 6047 6048 memset(&pdu, 0, sizeof(pdu)); 6049 6050 /* Check if we have socket listening on psm */ 6051 pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src, 6052 &conn->hcon->dst, LE_LINK); 6053 if (!pchan) { 6054 result = L2CAP_CR_LE_BAD_PSM; 6055 goto response; 6056 } 6057 6058 mutex_lock(&conn->chan_lock); 6059 l2cap_chan_lock(pchan); 6060 6061 if (!smp_sufficient_security(conn->hcon, pchan->sec_level, 6062 SMP_ALLOW_STK)) { 6063 result = L2CAP_CR_LE_AUTHENTICATION; 6064 goto unlock; 6065 } 6066 6067 result = L2CAP_CR_LE_SUCCESS; 6068 6069 for (i = 0; i < num_scid; i++) { 6070 u16 scid = __le16_to_cpu(req->scid[i]); 6071 6072 BT_DBG("scid[%d] 0x%4.4x", i, scid); 6073 6074 pdu.dcid[i] = 0x0000; 6075 len += sizeof(*pdu.dcid); 6076 6077 /* Check for valid dynamic CID range */ 6078 if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_LE_DYN_END) { 6079 result = L2CAP_CR_LE_INVALID_SCID; 6080 continue; 6081 } 6082 6083 /* Check if we already have channel with that dcid */ 6084 if (__l2cap_get_chan_by_dcid(conn, scid)) { 6085 result = L2CAP_CR_LE_SCID_IN_USE; 6086 continue; 6087 } 6088 6089 chan = pchan->ops->new_connection(pchan); 6090 if (!chan) { 6091 result = L2CAP_CR_LE_NO_MEM; 6092 continue; 6093 } 6094 6095 bacpy(&chan->src, &conn->hcon->src); 6096 bacpy(&chan->dst, &conn->hcon->dst); 6097 chan->src_type = bdaddr_src_type(conn->hcon); 6098 chan->dst_type = bdaddr_dst_type(conn->hcon); 6099 chan->psm = psm; 6100 chan->dcid = scid; 6101 chan->omtu = mtu; 6102 chan->remote_mps = mps; 6103 6104 __l2cap_chan_add(conn, chan); 6105 6106 l2cap_ecred_init(chan, __le16_to_cpu(req->credits)); 6107 6108 /* Init response */ 6109 if (!pdu.rsp.credits) { 6110 pdu.rsp.mtu = cpu_to_le16(chan->imtu); 6111 pdu.rsp.mps = cpu_to_le16(chan->mps); 6112 pdu.rsp.credits = cpu_to_le16(chan->rx_credits); 6113 } 6114 6115 pdu.dcid[i] = cpu_to_le16(chan->scid); 6116 6117 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan)); 6118 6119 chan->ident = cmd->ident; 6120 chan->mode = L2CAP_MODE_EXT_FLOWCTL; 6121 6122 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) { 6123 l2cap_state_change(chan, BT_CONNECT2); 6124 defer = true; 6125 chan->ops->defer(chan); 6126 } else { 6127 l2cap_chan_ready(chan); 6128 } 6129 } 6130 6131 unlock: 6132 l2cap_chan_unlock(pchan); 6133 mutex_unlock(&conn->chan_lock); 6134 l2cap_chan_put(pchan); 6135 6136 response: 6137 pdu.rsp.result = cpu_to_le16(result); 6138 6139 if (defer) 6140 return 0; 6141 6142 l2cap_send_cmd(conn, cmd->ident, L2CAP_ECRED_CONN_RSP, 6143 sizeof(pdu.rsp) + len, &pdu); 6144 6145 return 0; 6146 } 6147 6148 static inline int l2cap_ecred_conn_rsp(struct l2cap_conn *conn, 6149 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 6150 u8 *data) 6151 { 6152 struct l2cap_ecred_conn_rsp *rsp = (void *) data; 6153 struct hci_conn *hcon = conn->hcon; 6154 u16 mtu, mps, credits, result; 6155 struct l2cap_chan *chan, *tmp; 6156 int err = 0, sec_level; 6157 int i = 0; 6158 6159 if (cmd_len < sizeof(*rsp)) 6160 return -EPROTO; 6161 6162 mtu = __le16_to_cpu(rsp->mtu); 6163 mps = __le16_to_cpu(rsp->mps); 6164 credits = __le16_to_cpu(rsp->credits); 6165 result = __le16_to_cpu(rsp->result); 6166 6167 BT_DBG("mtu %u mps %u credits %u result 0x%4.4x", mtu, mps, credits, 6168 result); 6169 6170 mutex_lock(&conn->chan_lock); 6171 6172 cmd_len -= sizeof(*rsp); 6173 6174 list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) { 6175 u16 dcid; 6176 6177 if (chan->ident != cmd->ident || 6178 chan->mode != L2CAP_MODE_EXT_FLOWCTL || 6179 chan->state == BT_CONNECTED) 6180 continue; 6181 6182 l2cap_chan_lock(chan); 6183 6184 /* Check that there is a dcid for each pending channel */ 6185 if (cmd_len < sizeof(dcid)) { 6186 l2cap_chan_del(chan, ECONNREFUSED); 6187 l2cap_chan_unlock(chan); 6188 continue; 6189 } 6190 6191 dcid = __le16_to_cpu(rsp->dcid[i++]); 6192 cmd_len -= sizeof(u16); 6193 6194 BT_DBG("dcid[%d] 0x%4.4x", i, dcid); 6195 6196 /* Check if dcid is already in use */ 6197 if (dcid && __l2cap_get_chan_by_dcid(conn, dcid)) { 6198 /* If a device receives a 6199 * L2CAP_CREDIT_BASED_CONNECTION_RSP packet with an 6200 * already-assigned Destination CID, then both the 6201 * original channel and the new channel shall be 6202 * immediately discarded and not used. 6203 */ 6204 l2cap_chan_del(chan, ECONNREFUSED); 6205 l2cap_chan_unlock(chan); 6206 chan = __l2cap_get_chan_by_dcid(conn, dcid); 6207 l2cap_chan_lock(chan); 6208 l2cap_chan_del(chan, ECONNRESET); 6209 l2cap_chan_unlock(chan); 6210 continue; 6211 } 6212 6213 switch (result) { 6214 case L2CAP_CR_LE_AUTHENTICATION: 6215 case L2CAP_CR_LE_ENCRYPTION: 6216 /* If we already have MITM protection we can't do 6217 * anything. 6218 */ 6219 if (hcon->sec_level > BT_SECURITY_MEDIUM) { 6220 l2cap_chan_del(chan, ECONNREFUSED); 6221 break; 6222 } 6223 6224 sec_level = hcon->sec_level + 1; 6225 if (chan->sec_level < sec_level) 6226 chan->sec_level = sec_level; 6227 6228 /* We'll need to send a new Connect Request */ 6229 clear_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags); 6230 6231 smp_conn_security(hcon, chan->sec_level); 6232 break; 6233 6234 case L2CAP_CR_LE_BAD_PSM: 6235 l2cap_chan_del(chan, ECONNREFUSED); 6236 break; 6237 6238 default: 6239 /* If dcid was not set it means channels was refused */ 6240 if (!dcid) { 6241 l2cap_chan_del(chan, ECONNREFUSED); 6242 break; 6243 } 6244 6245 chan->ident = 0; 6246 chan->dcid = dcid; 6247 chan->omtu = mtu; 6248 chan->remote_mps = mps; 6249 chan->tx_credits = credits; 6250 l2cap_chan_ready(chan); 6251 break; 6252 } 6253 6254 l2cap_chan_unlock(chan); 6255 } 6256 6257 mutex_unlock(&conn->chan_lock); 6258 6259 return err; 6260 } 6261 6262 static inline int l2cap_ecred_reconf_req(struct l2cap_conn *conn, 6263 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 6264 u8 *data) 6265 { 6266 struct l2cap_ecred_reconf_req *req = (void *) data; 6267 struct l2cap_ecred_reconf_rsp rsp; 6268 u16 mtu, mps, result; 6269 struct l2cap_chan *chan; 6270 int i, num_scid; 6271 6272 if (!enable_ecred) 6273 return -EINVAL; 6274 6275 if (cmd_len < sizeof(*req) || cmd_len - sizeof(*req) % sizeof(u16)) { 6276 result = L2CAP_CR_LE_INVALID_PARAMS; 6277 goto respond; 6278 } 6279 6280 mtu = __le16_to_cpu(req->mtu); 6281 mps = __le16_to_cpu(req->mps); 6282 6283 BT_DBG("mtu %u mps %u", mtu, mps); 6284 6285 if (mtu < L2CAP_ECRED_MIN_MTU) { 6286 result = L2CAP_RECONF_INVALID_MTU; 6287 goto respond; 6288 } 6289 6290 if (mps < L2CAP_ECRED_MIN_MPS) { 6291 result = L2CAP_RECONF_INVALID_MPS; 6292 goto respond; 6293 } 6294 6295 cmd_len -= sizeof(*req); 6296 num_scid = cmd_len / sizeof(u16); 6297 result = L2CAP_RECONF_SUCCESS; 6298 6299 for (i = 0; i < num_scid; i++) { 6300 u16 scid; 6301 6302 scid = __le16_to_cpu(req->scid[i]); 6303 if (!scid) 6304 return -EPROTO; 6305 6306 chan = __l2cap_get_chan_by_dcid(conn, scid); 6307 if (!chan) 6308 continue; 6309 6310 /* If the MTU value is decreased for any of the included 6311 * channels, then the receiver shall disconnect all 6312 * included channels. 6313 */ 6314 if (chan->omtu > mtu) { 6315 BT_ERR("chan %p decreased MTU %u -> %u", chan, 6316 chan->omtu, mtu); 6317 result = L2CAP_RECONF_INVALID_MTU; 6318 } 6319 6320 chan->omtu = mtu; 6321 chan->remote_mps = mps; 6322 } 6323 6324 respond: 6325 rsp.result = cpu_to_le16(result); 6326 6327 l2cap_send_cmd(conn, cmd->ident, L2CAP_ECRED_RECONF_RSP, sizeof(rsp), 6328 &rsp); 6329 6330 return 0; 6331 } 6332 6333 static inline int l2cap_ecred_reconf_rsp(struct l2cap_conn *conn, 6334 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 6335 u8 *data) 6336 { 6337 struct l2cap_chan *chan, *tmp; 6338 struct l2cap_ecred_conn_rsp *rsp = (void *) data; 6339 u16 result; 6340 6341 if (cmd_len < sizeof(*rsp)) 6342 return -EPROTO; 6343 6344 result = __le16_to_cpu(rsp->result); 6345 6346 BT_DBG("result 0x%4.4x", rsp->result); 6347 6348 if (!result) 6349 return 0; 6350 6351 list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) { 6352 if (chan->ident != cmd->ident) 6353 continue; 6354 6355 l2cap_chan_del(chan, ECONNRESET); 6356 } 6357 6358 return 0; 6359 } 6360 6361 static inline int l2cap_le_command_rej(struct l2cap_conn *conn, 6362 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 6363 u8 *data) 6364 { 6365 struct l2cap_cmd_rej_unk *rej = (struct l2cap_cmd_rej_unk *) data; 6366 struct l2cap_chan *chan; 6367 6368 if (cmd_len < sizeof(*rej)) 6369 return -EPROTO; 6370 6371 mutex_lock(&conn->chan_lock); 6372 6373 chan = __l2cap_get_chan_by_ident(conn, cmd->ident); 6374 if (!chan) 6375 goto done; 6376 6377 l2cap_chan_lock(chan); 6378 l2cap_chan_del(chan, ECONNREFUSED); 6379 l2cap_chan_unlock(chan); 6380 6381 done: 6382 mutex_unlock(&conn->chan_lock); 6383 return 0; 6384 } 6385 6386 static inline int l2cap_le_sig_cmd(struct l2cap_conn *conn, 6387 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 6388 u8 *data) 6389 { 6390 int err = 0; 6391 6392 switch (cmd->code) { 6393 case L2CAP_COMMAND_REJ: 6394 l2cap_le_command_rej(conn, cmd, cmd_len, data); 6395 break; 6396 6397 case L2CAP_CONN_PARAM_UPDATE_REQ: 6398 err = l2cap_conn_param_update_req(conn, cmd, cmd_len, data); 6399 break; 6400 6401 case L2CAP_CONN_PARAM_UPDATE_RSP: 6402 break; 6403 6404 case L2CAP_LE_CONN_RSP: 6405 l2cap_le_connect_rsp(conn, cmd, cmd_len, data); 6406 break; 6407 6408 case L2CAP_LE_CONN_REQ: 6409 err = l2cap_le_connect_req(conn, cmd, cmd_len, data); 6410 break; 6411 6412 case L2CAP_LE_CREDITS: 6413 err = l2cap_le_credits(conn, cmd, cmd_len, data); 6414 break; 6415 6416 case L2CAP_ECRED_CONN_REQ: 6417 err = l2cap_ecred_conn_req(conn, cmd, cmd_len, data); 6418 break; 6419 6420 case L2CAP_ECRED_CONN_RSP: 6421 err = l2cap_ecred_conn_rsp(conn, cmd, cmd_len, data); 6422 break; 6423 6424 case L2CAP_ECRED_RECONF_REQ: 6425 err = l2cap_ecred_reconf_req(conn, cmd, cmd_len, data); 6426 break; 6427 6428 case L2CAP_ECRED_RECONF_RSP: 6429 err = l2cap_ecred_reconf_rsp(conn, cmd, cmd_len, data); 6430 break; 6431 6432 case L2CAP_DISCONN_REQ: 6433 err = l2cap_disconnect_req(conn, cmd, cmd_len, data); 6434 break; 6435 6436 case L2CAP_DISCONN_RSP: 6437 l2cap_disconnect_rsp(conn, cmd, cmd_len, data); 6438 break; 6439 6440 default: 6441 BT_ERR("Unknown LE signaling command 0x%2.2x", cmd->code); 6442 err = -EINVAL; 6443 break; 6444 } 6445 6446 return err; 6447 } 6448 6449 static inline void l2cap_le_sig_channel(struct l2cap_conn *conn, 6450 struct sk_buff *skb) 6451 { 6452 struct hci_conn *hcon = conn->hcon; 6453 struct l2cap_cmd_hdr *cmd; 6454 u16 len; 6455 int err; 6456 6457 if (hcon->type != LE_LINK) 6458 goto drop; 6459 6460 if (skb->len < L2CAP_CMD_HDR_SIZE) 6461 goto drop; 6462 6463 cmd = (void *) skb->data; 6464 skb_pull(skb, L2CAP_CMD_HDR_SIZE); 6465 6466 len = le16_to_cpu(cmd->len); 6467 6468 BT_DBG("code 0x%2.2x len %d id 0x%2.2x", cmd->code, len, cmd->ident); 6469 6470 if (len != skb->len || !cmd->ident) { 6471 BT_DBG("corrupted command"); 6472 goto drop; 6473 } 6474 6475 err = l2cap_le_sig_cmd(conn, cmd, len, skb->data); 6476 if (err) { 6477 struct l2cap_cmd_rej_unk rej; 6478 6479 BT_ERR("Wrong link type (%d)", err); 6480 6481 rej.reason = cpu_to_le16(L2CAP_REJ_NOT_UNDERSTOOD); 6482 l2cap_send_cmd(conn, cmd->ident, L2CAP_COMMAND_REJ, 6483 sizeof(rej), &rej); 6484 } 6485 6486 drop: 6487 kfree_skb(skb); 6488 } 6489 6490 static inline void l2cap_sig_channel(struct l2cap_conn *conn, 6491 struct sk_buff *skb) 6492 { 6493 struct hci_conn *hcon = conn->hcon; 6494 struct l2cap_cmd_hdr *cmd; 6495 int err; 6496 6497 l2cap_raw_recv(conn, skb); 6498 6499 if (hcon->type != ACL_LINK) 6500 goto drop; 6501 6502 while (skb->len >= L2CAP_CMD_HDR_SIZE) { 6503 u16 len; 6504 6505 cmd = (void *) skb->data; 6506 skb_pull(skb, L2CAP_CMD_HDR_SIZE); 6507 6508 len = le16_to_cpu(cmd->len); 6509 6510 BT_DBG("code 0x%2.2x len %d id 0x%2.2x", cmd->code, len, 6511 cmd->ident); 6512 6513 if (len > skb->len || !cmd->ident) { 6514 BT_DBG("corrupted command"); 6515 break; 6516 } 6517 6518 err = l2cap_bredr_sig_cmd(conn, cmd, len, skb->data); 6519 if (err) { 6520 struct l2cap_cmd_rej_unk rej; 6521 6522 BT_ERR("Wrong link type (%d)", err); 6523 6524 rej.reason = cpu_to_le16(L2CAP_REJ_NOT_UNDERSTOOD); 6525 l2cap_send_cmd(conn, cmd->ident, L2CAP_COMMAND_REJ, 6526 sizeof(rej), &rej); 6527 } 6528 6529 skb_pull(skb, len); 6530 } 6531 6532 drop: 6533 kfree_skb(skb); 6534 } 6535 6536 static int l2cap_check_fcs(struct l2cap_chan *chan, struct sk_buff *skb) 6537 { 6538 u16 our_fcs, rcv_fcs; 6539 int hdr_size; 6540 6541 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) 6542 hdr_size = L2CAP_EXT_HDR_SIZE; 6543 else 6544 hdr_size = L2CAP_ENH_HDR_SIZE; 6545 6546 if (chan->fcs == L2CAP_FCS_CRC16) { 6547 skb_trim(skb, skb->len - L2CAP_FCS_SIZE); 6548 rcv_fcs = get_unaligned_le16(skb->data + skb->len); 6549 our_fcs = crc16(0, skb->data - hdr_size, skb->len + hdr_size); 6550 6551 if (our_fcs != rcv_fcs) 6552 return -EBADMSG; 6553 } 6554 return 0; 6555 } 6556 6557 static void l2cap_send_i_or_rr_or_rnr(struct l2cap_chan *chan) 6558 { 6559 struct l2cap_ctrl control; 6560 6561 BT_DBG("chan %p", chan); 6562 6563 memset(&control, 0, sizeof(control)); 6564 control.sframe = 1; 6565 control.final = 1; 6566 control.reqseq = chan->buffer_seq; 6567 set_bit(CONN_SEND_FBIT, &chan->conn_state); 6568 6569 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) { 6570 control.super = L2CAP_SUPER_RNR; 6571 l2cap_send_sframe(chan, &control); 6572 } 6573 6574 if (test_and_clear_bit(CONN_REMOTE_BUSY, &chan->conn_state) && 6575 chan->unacked_frames > 0) 6576 __set_retrans_timer(chan); 6577 6578 /* Send pending iframes */ 6579 l2cap_ertm_send(chan); 6580 6581 if (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state) && 6582 test_bit(CONN_SEND_FBIT, &chan->conn_state)) { 6583 /* F-bit wasn't sent in an s-frame or i-frame yet, so 6584 * send it now. 6585 */ 6586 control.super = L2CAP_SUPER_RR; 6587 l2cap_send_sframe(chan, &control); 6588 } 6589 } 6590 6591 static void append_skb_frag(struct sk_buff *skb, struct sk_buff *new_frag, 6592 struct sk_buff **last_frag) 6593 { 6594 /* skb->len reflects data in skb as well as all fragments 6595 * skb->data_len reflects only data in fragments 6596 */ 6597 if (!skb_has_frag_list(skb)) 6598 skb_shinfo(skb)->frag_list = new_frag; 6599 6600 new_frag->next = NULL; 6601 6602 (*last_frag)->next = new_frag; 6603 *last_frag = new_frag; 6604 6605 skb->len += new_frag->len; 6606 skb->data_len += new_frag->len; 6607 skb->truesize += new_frag->truesize; 6608 } 6609 6610 static int l2cap_reassemble_sdu(struct l2cap_chan *chan, struct sk_buff *skb, 6611 struct l2cap_ctrl *control) 6612 { 6613 int err = -EINVAL; 6614 6615 switch (control->sar) { 6616 case L2CAP_SAR_UNSEGMENTED: 6617 if (chan->sdu) 6618 break; 6619 6620 err = chan->ops->recv(chan, skb); 6621 break; 6622 6623 case L2CAP_SAR_START: 6624 if (chan->sdu) 6625 break; 6626 6627 if (!pskb_may_pull(skb, L2CAP_SDULEN_SIZE)) 6628 break; 6629 6630 chan->sdu_len = get_unaligned_le16(skb->data); 6631 skb_pull(skb, L2CAP_SDULEN_SIZE); 6632 6633 if (chan->sdu_len > chan->imtu) { 6634 err = -EMSGSIZE; 6635 break; 6636 } 6637 6638 if (skb->len >= chan->sdu_len) 6639 break; 6640 6641 chan->sdu = skb; 6642 chan->sdu_last_frag = skb; 6643 6644 skb = NULL; 6645 err = 0; 6646 break; 6647 6648 case L2CAP_SAR_CONTINUE: 6649 if (!chan->sdu) 6650 break; 6651 6652 append_skb_frag(chan->sdu, skb, 6653 &chan->sdu_last_frag); 6654 skb = NULL; 6655 6656 if (chan->sdu->len >= chan->sdu_len) 6657 break; 6658 6659 err = 0; 6660 break; 6661 6662 case L2CAP_SAR_END: 6663 if (!chan->sdu) 6664 break; 6665 6666 append_skb_frag(chan->sdu, skb, 6667 &chan->sdu_last_frag); 6668 skb = NULL; 6669 6670 if (chan->sdu->len != chan->sdu_len) 6671 break; 6672 6673 err = chan->ops->recv(chan, chan->sdu); 6674 6675 if (!err) { 6676 /* Reassembly complete */ 6677 chan->sdu = NULL; 6678 chan->sdu_last_frag = NULL; 6679 chan->sdu_len = 0; 6680 } 6681 break; 6682 } 6683 6684 if (err) { 6685 kfree_skb(skb); 6686 kfree_skb(chan->sdu); 6687 chan->sdu = NULL; 6688 chan->sdu_last_frag = NULL; 6689 chan->sdu_len = 0; 6690 } 6691 6692 return err; 6693 } 6694 6695 static int l2cap_resegment(struct l2cap_chan *chan) 6696 { 6697 /* Placeholder */ 6698 return 0; 6699 } 6700 6701 void l2cap_chan_busy(struct l2cap_chan *chan, int busy) 6702 { 6703 u8 event; 6704 6705 if (chan->mode != L2CAP_MODE_ERTM) 6706 return; 6707 6708 event = busy ? L2CAP_EV_LOCAL_BUSY_DETECTED : L2CAP_EV_LOCAL_BUSY_CLEAR; 6709 l2cap_tx(chan, NULL, NULL, event); 6710 } 6711 6712 static int l2cap_rx_queued_iframes(struct l2cap_chan *chan) 6713 { 6714 int err = 0; 6715 /* Pass sequential frames to l2cap_reassemble_sdu() 6716 * until a gap is encountered. 6717 */ 6718 6719 BT_DBG("chan %p", chan); 6720 6721 while (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) { 6722 struct sk_buff *skb; 6723 BT_DBG("Searching for skb with txseq %d (queue len %d)", 6724 chan->buffer_seq, skb_queue_len(&chan->srej_q)); 6725 6726 skb = l2cap_ertm_seq_in_queue(&chan->srej_q, chan->buffer_seq); 6727 6728 if (!skb) 6729 break; 6730 6731 skb_unlink(skb, &chan->srej_q); 6732 chan->buffer_seq = __next_seq(chan, chan->buffer_seq); 6733 err = l2cap_reassemble_sdu(chan, skb, &bt_cb(skb)->l2cap); 6734 if (err) 6735 break; 6736 } 6737 6738 if (skb_queue_empty(&chan->srej_q)) { 6739 chan->rx_state = L2CAP_RX_STATE_RECV; 6740 l2cap_send_ack(chan); 6741 } 6742 6743 return err; 6744 } 6745 6746 static void l2cap_handle_srej(struct l2cap_chan *chan, 6747 struct l2cap_ctrl *control) 6748 { 6749 struct sk_buff *skb; 6750 6751 BT_DBG("chan %p, control %p", chan, control); 6752 6753 if (control->reqseq == chan->next_tx_seq) { 6754 BT_DBG("Invalid reqseq %d, disconnecting", control->reqseq); 6755 l2cap_send_disconn_req(chan, ECONNRESET); 6756 return; 6757 } 6758 6759 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, control->reqseq); 6760 6761 if (skb == NULL) { 6762 BT_DBG("Seq %d not available for retransmission", 6763 control->reqseq); 6764 return; 6765 } 6766 6767 if (chan->max_tx != 0 && bt_cb(skb)->l2cap.retries >= chan->max_tx) { 6768 BT_DBG("Retry limit exceeded (%d)", chan->max_tx); 6769 l2cap_send_disconn_req(chan, ECONNRESET); 6770 return; 6771 } 6772 6773 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state); 6774 6775 if (control->poll) { 6776 l2cap_pass_to_tx(chan, control); 6777 6778 set_bit(CONN_SEND_FBIT, &chan->conn_state); 6779 l2cap_retransmit(chan, control); 6780 l2cap_ertm_send(chan); 6781 6782 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F) { 6783 set_bit(CONN_SREJ_ACT, &chan->conn_state); 6784 chan->srej_save_reqseq = control->reqseq; 6785 } 6786 } else { 6787 l2cap_pass_to_tx_fbit(chan, control); 6788 6789 if (control->final) { 6790 if (chan->srej_save_reqseq != control->reqseq || 6791 !test_and_clear_bit(CONN_SREJ_ACT, 6792 &chan->conn_state)) 6793 l2cap_retransmit(chan, control); 6794 } else { 6795 l2cap_retransmit(chan, control); 6796 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F) { 6797 set_bit(CONN_SREJ_ACT, &chan->conn_state); 6798 chan->srej_save_reqseq = control->reqseq; 6799 } 6800 } 6801 } 6802 } 6803 6804 static void l2cap_handle_rej(struct l2cap_chan *chan, 6805 struct l2cap_ctrl *control) 6806 { 6807 struct sk_buff *skb; 6808 6809 BT_DBG("chan %p, control %p", chan, control); 6810 6811 if (control->reqseq == chan->next_tx_seq) { 6812 BT_DBG("Invalid reqseq %d, disconnecting", control->reqseq); 6813 l2cap_send_disconn_req(chan, ECONNRESET); 6814 return; 6815 } 6816 6817 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, control->reqseq); 6818 6819 if (chan->max_tx && skb && 6820 bt_cb(skb)->l2cap.retries >= chan->max_tx) { 6821 BT_DBG("Retry limit exceeded (%d)", chan->max_tx); 6822 l2cap_send_disconn_req(chan, ECONNRESET); 6823 return; 6824 } 6825 6826 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state); 6827 6828 l2cap_pass_to_tx(chan, control); 6829 6830 if (control->final) { 6831 if (!test_and_clear_bit(CONN_REJ_ACT, &chan->conn_state)) 6832 l2cap_retransmit_all(chan, control); 6833 } else { 6834 l2cap_retransmit_all(chan, control); 6835 l2cap_ertm_send(chan); 6836 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F) 6837 set_bit(CONN_REJ_ACT, &chan->conn_state); 6838 } 6839 } 6840 6841 static u8 l2cap_classify_txseq(struct l2cap_chan *chan, u16 txseq) 6842 { 6843 BT_DBG("chan %p, txseq %d", chan, txseq); 6844 6845 BT_DBG("last_acked_seq %d, expected_tx_seq %d", chan->last_acked_seq, 6846 chan->expected_tx_seq); 6847 6848 if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) { 6849 if (__seq_offset(chan, txseq, chan->last_acked_seq) >= 6850 chan->tx_win) { 6851 /* See notes below regarding "double poll" and 6852 * invalid packets. 6853 */ 6854 if (chan->tx_win <= ((chan->tx_win_max + 1) >> 1)) { 6855 BT_DBG("Invalid/Ignore - after SREJ"); 6856 return L2CAP_TXSEQ_INVALID_IGNORE; 6857 } else { 6858 BT_DBG("Invalid - in window after SREJ sent"); 6859 return L2CAP_TXSEQ_INVALID; 6860 } 6861 } 6862 6863 if (chan->srej_list.head == txseq) { 6864 BT_DBG("Expected SREJ"); 6865 return L2CAP_TXSEQ_EXPECTED_SREJ; 6866 } 6867 6868 if (l2cap_ertm_seq_in_queue(&chan->srej_q, txseq)) { 6869 BT_DBG("Duplicate SREJ - txseq already stored"); 6870 return L2CAP_TXSEQ_DUPLICATE_SREJ; 6871 } 6872 6873 if (l2cap_seq_list_contains(&chan->srej_list, txseq)) { 6874 BT_DBG("Unexpected SREJ - not requested"); 6875 return L2CAP_TXSEQ_UNEXPECTED_SREJ; 6876 } 6877 } 6878 6879 if (chan->expected_tx_seq == txseq) { 6880 if (__seq_offset(chan, txseq, chan->last_acked_seq) >= 6881 chan->tx_win) { 6882 BT_DBG("Invalid - txseq outside tx window"); 6883 return L2CAP_TXSEQ_INVALID; 6884 } else { 6885 BT_DBG("Expected"); 6886 return L2CAP_TXSEQ_EXPECTED; 6887 } 6888 } 6889 6890 if (__seq_offset(chan, txseq, chan->last_acked_seq) < 6891 __seq_offset(chan, chan->expected_tx_seq, chan->last_acked_seq)) { 6892 BT_DBG("Duplicate - expected_tx_seq later than txseq"); 6893 return L2CAP_TXSEQ_DUPLICATE; 6894 } 6895 6896 if (__seq_offset(chan, txseq, chan->last_acked_seq) >= chan->tx_win) { 6897 /* A source of invalid packets is a "double poll" condition, 6898 * where delays cause us to send multiple poll packets. If 6899 * the remote stack receives and processes both polls, 6900 * sequence numbers can wrap around in such a way that a 6901 * resent frame has a sequence number that looks like new data 6902 * with a sequence gap. This would trigger an erroneous SREJ 6903 * request. 6904 * 6905 * Fortunately, this is impossible with a tx window that's 6906 * less than half of the maximum sequence number, which allows 6907 * invalid frames to be safely ignored. 6908 * 6909 * With tx window sizes greater than half of the tx window 6910 * maximum, the frame is invalid and cannot be ignored. This 6911 * causes a disconnect. 6912 */ 6913 6914 if (chan->tx_win <= ((chan->tx_win_max + 1) >> 1)) { 6915 BT_DBG("Invalid/Ignore - txseq outside tx window"); 6916 return L2CAP_TXSEQ_INVALID_IGNORE; 6917 } else { 6918 BT_DBG("Invalid - txseq outside tx window"); 6919 return L2CAP_TXSEQ_INVALID; 6920 } 6921 } else { 6922 BT_DBG("Unexpected - txseq indicates missing frames"); 6923 return L2CAP_TXSEQ_UNEXPECTED; 6924 } 6925 } 6926 6927 static int l2cap_rx_state_recv(struct l2cap_chan *chan, 6928 struct l2cap_ctrl *control, 6929 struct sk_buff *skb, u8 event) 6930 { 6931 struct l2cap_ctrl local_control; 6932 int err = 0; 6933 bool skb_in_use = false; 6934 6935 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb, 6936 event); 6937 6938 switch (event) { 6939 case L2CAP_EV_RECV_IFRAME: 6940 switch (l2cap_classify_txseq(chan, control->txseq)) { 6941 case L2CAP_TXSEQ_EXPECTED: 6942 l2cap_pass_to_tx(chan, control); 6943 6944 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) { 6945 BT_DBG("Busy, discarding expected seq %d", 6946 control->txseq); 6947 break; 6948 } 6949 6950 chan->expected_tx_seq = __next_seq(chan, 6951 control->txseq); 6952 6953 chan->buffer_seq = chan->expected_tx_seq; 6954 skb_in_use = true; 6955 6956 /* l2cap_reassemble_sdu may free skb, hence invalidate 6957 * control, so make a copy in advance to use it after 6958 * l2cap_reassemble_sdu returns and to avoid the race 6959 * condition, for example: 6960 * 6961 * The current thread calls: 6962 * l2cap_reassemble_sdu 6963 * chan->ops->recv == l2cap_sock_recv_cb 6964 * __sock_queue_rcv_skb 6965 * Another thread calls: 6966 * bt_sock_recvmsg 6967 * skb_recv_datagram 6968 * skb_free_datagram 6969 * Then the current thread tries to access control, but 6970 * it was freed by skb_free_datagram. 6971 */ 6972 local_control = *control; 6973 err = l2cap_reassemble_sdu(chan, skb, control); 6974 if (err) 6975 break; 6976 6977 if (local_control.final) { 6978 if (!test_and_clear_bit(CONN_REJ_ACT, 6979 &chan->conn_state)) { 6980 local_control.final = 0; 6981 l2cap_retransmit_all(chan, &local_control); 6982 l2cap_ertm_send(chan); 6983 } 6984 } 6985 6986 if (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) 6987 l2cap_send_ack(chan); 6988 break; 6989 case L2CAP_TXSEQ_UNEXPECTED: 6990 l2cap_pass_to_tx(chan, control); 6991 6992 /* Can't issue SREJ frames in the local busy state. 6993 * Drop this frame, it will be seen as missing 6994 * when local busy is exited. 6995 */ 6996 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) { 6997 BT_DBG("Busy, discarding unexpected seq %d", 6998 control->txseq); 6999 break; 7000 } 7001 7002 /* There was a gap in the sequence, so an SREJ 7003 * must be sent for each missing frame. The 7004 * current frame is stored for later use. 7005 */ 7006 skb_queue_tail(&chan->srej_q, skb); 7007 skb_in_use = true; 7008 BT_DBG("Queued %p (queue len %d)", skb, 7009 skb_queue_len(&chan->srej_q)); 7010 7011 clear_bit(CONN_SREJ_ACT, &chan->conn_state); 7012 l2cap_seq_list_clear(&chan->srej_list); 7013 l2cap_send_srej(chan, control->txseq); 7014 7015 chan->rx_state = L2CAP_RX_STATE_SREJ_SENT; 7016 break; 7017 case L2CAP_TXSEQ_DUPLICATE: 7018 l2cap_pass_to_tx(chan, control); 7019 break; 7020 case L2CAP_TXSEQ_INVALID_IGNORE: 7021 break; 7022 case L2CAP_TXSEQ_INVALID: 7023 default: 7024 l2cap_send_disconn_req(chan, ECONNRESET); 7025 break; 7026 } 7027 break; 7028 case L2CAP_EV_RECV_RR: 7029 l2cap_pass_to_tx(chan, control); 7030 if (control->final) { 7031 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state); 7032 7033 if (!test_and_clear_bit(CONN_REJ_ACT, &chan->conn_state) && 7034 !__chan_is_moving(chan)) { 7035 control->final = 0; 7036 l2cap_retransmit_all(chan, control); 7037 } 7038 7039 l2cap_ertm_send(chan); 7040 } else if (control->poll) { 7041 l2cap_send_i_or_rr_or_rnr(chan); 7042 } else { 7043 if (test_and_clear_bit(CONN_REMOTE_BUSY, 7044 &chan->conn_state) && 7045 chan->unacked_frames) 7046 __set_retrans_timer(chan); 7047 7048 l2cap_ertm_send(chan); 7049 } 7050 break; 7051 case L2CAP_EV_RECV_RNR: 7052 set_bit(CONN_REMOTE_BUSY, &chan->conn_state); 7053 l2cap_pass_to_tx(chan, control); 7054 if (control && control->poll) { 7055 set_bit(CONN_SEND_FBIT, &chan->conn_state); 7056 l2cap_send_rr_or_rnr(chan, 0); 7057 } 7058 __clear_retrans_timer(chan); 7059 l2cap_seq_list_clear(&chan->retrans_list); 7060 break; 7061 case L2CAP_EV_RECV_REJ: 7062 l2cap_handle_rej(chan, control); 7063 break; 7064 case L2CAP_EV_RECV_SREJ: 7065 l2cap_handle_srej(chan, control); 7066 break; 7067 default: 7068 break; 7069 } 7070 7071 if (skb && !skb_in_use) { 7072 BT_DBG("Freeing %p", skb); 7073 kfree_skb(skb); 7074 } 7075 7076 return err; 7077 } 7078 7079 static int l2cap_rx_state_srej_sent(struct l2cap_chan *chan, 7080 struct l2cap_ctrl *control, 7081 struct sk_buff *skb, u8 event) 7082 { 7083 int err = 0; 7084 u16 txseq = control->txseq; 7085 bool skb_in_use = false; 7086 7087 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb, 7088 event); 7089 7090 switch (event) { 7091 case L2CAP_EV_RECV_IFRAME: 7092 switch (l2cap_classify_txseq(chan, txseq)) { 7093 case L2CAP_TXSEQ_EXPECTED: 7094 /* Keep frame for reassembly later */ 7095 l2cap_pass_to_tx(chan, control); 7096 skb_queue_tail(&chan->srej_q, skb); 7097 skb_in_use = true; 7098 BT_DBG("Queued %p (queue len %d)", skb, 7099 skb_queue_len(&chan->srej_q)); 7100 7101 chan->expected_tx_seq = __next_seq(chan, txseq); 7102 break; 7103 case L2CAP_TXSEQ_EXPECTED_SREJ: 7104 l2cap_seq_list_pop(&chan->srej_list); 7105 7106 l2cap_pass_to_tx(chan, control); 7107 skb_queue_tail(&chan->srej_q, skb); 7108 skb_in_use = true; 7109 BT_DBG("Queued %p (queue len %d)", skb, 7110 skb_queue_len(&chan->srej_q)); 7111 7112 err = l2cap_rx_queued_iframes(chan); 7113 if (err) 7114 break; 7115 7116 break; 7117 case L2CAP_TXSEQ_UNEXPECTED: 7118 /* Got a frame that can't be reassembled yet. 7119 * Save it for later, and send SREJs to cover 7120 * the missing frames. 7121 */ 7122 skb_queue_tail(&chan->srej_q, skb); 7123 skb_in_use = true; 7124 BT_DBG("Queued %p (queue len %d)", skb, 7125 skb_queue_len(&chan->srej_q)); 7126 7127 l2cap_pass_to_tx(chan, control); 7128 l2cap_send_srej(chan, control->txseq); 7129 break; 7130 case L2CAP_TXSEQ_UNEXPECTED_SREJ: 7131 /* This frame was requested with an SREJ, but 7132 * some expected retransmitted frames are 7133 * missing. Request retransmission of missing 7134 * SREJ'd frames. 7135 */ 7136 skb_queue_tail(&chan->srej_q, skb); 7137 skb_in_use = true; 7138 BT_DBG("Queued %p (queue len %d)", skb, 7139 skb_queue_len(&chan->srej_q)); 7140 7141 l2cap_pass_to_tx(chan, control); 7142 l2cap_send_srej_list(chan, control->txseq); 7143 break; 7144 case L2CAP_TXSEQ_DUPLICATE_SREJ: 7145 /* We've already queued this frame. Drop this copy. */ 7146 l2cap_pass_to_tx(chan, control); 7147 break; 7148 case L2CAP_TXSEQ_DUPLICATE: 7149 /* Expecting a later sequence number, so this frame 7150 * was already received. Ignore it completely. 7151 */ 7152 break; 7153 case L2CAP_TXSEQ_INVALID_IGNORE: 7154 break; 7155 case L2CAP_TXSEQ_INVALID: 7156 default: 7157 l2cap_send_disconn_req(chan, ECONNRESET); 7158 break; 7159 } 7160 break; 7161 case L2CAP_EV_RECV_RR: 7162 l2cap_pass_to_tx(chan, control); 7163 if (control->final) { 7164 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state); 7165 7166 if (!test_and_clear_bit(CONN_REJ_ACT, 7167 &chan->conn_state)) { 7168 control->final = 0; 7169 l2cap_retransmit_all(chan, control); 7170 } 7171 7172 l2cap_ertm_send(chan); 7173 } else if (control->poll) { 7174 if (test_and_clear_bit(CONN_REMOTE_BUSY, 7175 &chan->conn_state) && 7176 chan->unacked_frames) { 7177 __set_retrans_timer(chan); 7178 } 7179 7180 set_bit(CONN_SEND_FBIT, &chan->conn_state); 7181 l2cap_send_srej_tail(chan); 7182 } else { 7183 if (test_and_clear_bit(CONN_REMOTE_BUSY, 7184 &chan->conn_state) && 7185 chan->unacked_frames) 7186 __set_retrans_timer(chan); 7187 7188 l2cap_send_ack(chan); 7189 } 7190 break; 7191 case L2CAP_EV_RECV_RNR: 7192 set_bit(CONN_REMOTE_BUSY, &chan->conn_state); 7193 l2cap_pass_to_tx(chan, control); 7194 if (control->poll) { 7195 l2cap_send_srej_tail(chan); 7196 } else { 7197 struct l2cap_ctrl rr_control; 7198 memset(&rr_control, 0, sizeof(rr_control)); 7199 rr_control.sframe = 1; 7200 rr_control.super = L2CAP_SUPER_RR; 7201 rr_control.reqseq = chan->buffer_seq; 7202 l2cap_send_sframe(chan, &rr_control); 7203 } 7204 7205 break; 7206 case L2CAP_EV_RECV_REJ: 7207 l2cap_handle_rej(chan, control); 7208 break; 7209 case L2CAP_EV_RECV_SREJ: 7210 l2cap_handle_srej(chan, control); 7211 break; 7212 } 7213 7214 if (skb && !skb_in_use) { 7215 BT_DBG("Freeing %p", skb); 7216 kfree_skb(skb); 7217 } 7218 7219 return err; 7220 } 7221 7222 static int l2cap_finish_move(struct l2cap_chan *chan) 7223 { 7224 BT_DBG("chan %p", chan); 7225 7226 chan->rx_state = L2CAP_RX_STATE_RECV; 7227 7228 if (chan->hs_hcon) 7229 chan->conn->mtu = chan->hs_hcon->hdev->block_mtu; 7230 else 7231 chan->conn->mtu = chan->conn->hcon->hdev->acl_mtu; 7232 7233 return l2cap_resegment(chan); 7234 } 7235 7236 static int l2cap_rx_state_wait_p(struct l2cap_chan *chan, 7237 struct l2cap_ctrl *control, 7238 struct sk_buff *skb, u8 event) 7239 { 7240 int err; 7241 7242 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb, 7243 event); 7244 7245 if (!control->poll) 7246 return -EPROTO; 7247 7248 l2cap_process_reqseq(chan, control->reqseq); 7249 7250 if (!skb_queue_empty(&chan->tx_q)) 7251 chan->tx_send_head = skb_peek(&chan->tx_q); 7252 else 7253 chan->tx_send_head = NULL; 7254 7255 /* Rewind next_tx_seq to the point expected 7256 * by the receiver. 7257 */ 7258 chan->next_tx_seq = control->reqseq; 7259 chan->unacked_frames = 0; 7260 7261 err = l2cap_finish_move(chan); 7262 if (err) 7263 return err; 7264 7265 set_bit(CONN_SEND_FBIT, &chan->conn_state); 7266 l2cap_send_i_or_rr_or_rnr(chan); 7267 7268 if (event == L2CAP_EV_RECV_IFRAME) 7269 return -EPROTO; 7270 7271 return l2cap_rx_state_recv(chan, control, NULL, event); 7272 } 7273 7274 static int l2cap_rx_state_wait_f(struct l2cap_chan *chan, 7275 struct l2cap_ctrl *control, 7276 struct sk_buff *skb, u8 event) 7277 { 7278 int err; 7279 7280 if (!control->final) 7281 return -EPROTO; 7282 7283 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state); 7284 7285 chan->rx_state = L2CAP_RX_STATE_RECV; 7286 l2cap_process_reqseq(chan, control->reqseq); 7287 7288 if (!skb_queue_empty(&chan->tx_q)) 7289 chan->tx_send_head = skb_peek(&chan->tx_q); 7290 else 7291 chan->tx_send_head = NULL; 7292 7293 /* Rewind next_tx_seq to the point expected 7294 * by the receiver. 7295 */ 7296 chan->next_tx_seq = control->reqseq; 7297 chan->unacked_frames = 0; 7298 7299 if (chan->hs_hcon) 7300 chan->conn->mtu = chan->hs_hcon->hdev->block_mtu; 7301 else 7302 chan->conn->mtu = chan->conn->hcon->hdev->acl_mtu; 7303 7304 err = l2cap_resegment(chan); 7305 7306 if (!err) 7307 err = l2cap_rx_state_recv(chan, control, skb, event); 7308 7309 return err; 7310 } 7311 7312 static bool __valid_reqseq(struct l2cap_chan *chan, u16 reqseq) 7313 { 7314 /* Make sure reqseq is for a packet that has been sent but not acked */ 7315 u16 unacked; 7316 7317 unacked = __seq_offset(chan, chan->next_tx_seq, chan->expected_ack_seq); 7318 return __seq_offset(chan, chan->next_tx_seq, reqseq) <= unacked; 7319 } 7320 7321 static int l2cap_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control, 7322 struct sk_buff *skb, u8 event) 7323 { 7324 int err = 0; 7325 7326 BT_DBG("chan %p, control %p, skb %p, event %d, state %d", chan, 7327 control, skb, event, chan->rx_state); 7328 7329 if (__valid_reqseq(chan, control->reqseq)) { 7330 switch (chan->rx_state) { 7331 case L2CAP_RX_STATE_RECV: 7332 err = l2cap_rx_state_recv(chan, control, skb, event); 7333 break; 7334 case L2CAP_RX_STATE_SREJ_SENT: 7335 err = l2cap_rx_state_srej_sent(chan, control, skb, 7336 event); 7337 break; 7338 case L2CAP_RX_STATE_WAIT_P: 7339 err = l2cap_rx_state_wait_p(chan, control, skb, event); 7340 break; 7341 case L2CAP_RX_STATE_WAIT_F: 7342 err = l2cap_rx_state_wait_f(chan, control, skb, event); 7343 break; 7344 default: 7345 /* shut it down */ 7346 break; 7347 } 7348 } else { 7349 BT_DBG("Invalid reqseq %d (next_tx_seq %d, expected_ack_seq %d", 7350 control->reqseq, chan->next_tx_seq, 7351 chan->expected_ack_seq); 7352 l2cap_send_disconn_req(chan, ECONNRESET); 7353 } 7354 7355 return err; 7356 } 7357 7358 static int l2cap_stream_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control, 7359 struct sk_buff *skb) 7360 { 7361 /* l2cap_reassemble_sdu may free skb, hence invalidate control, so store 7362 * the txseq field in advance to use it after l2cap_reassemble_sdu 7363 * returns and to avoid the race condition, for example: 7364 * 7365 * The current thread calls: 7366 * l2cap_reassemble_sdu 7367 * chan->ops->recv == l2cap_sock_recv_cb 7368 * __sock_queue_rcv_skb 7369 * Another thread calls: 7370 * bt_sock_recvmsg 7371 * skb_recv_datagram 7372 * skb_free_datagram 7373 * Then the current thread tries to access control, but it was freed by 7374 * skb_free_datagram. 7375 */ 7376 u16 txseq = control->txseq; 7377 7378 BT_DBG("chan %p, control %p, skb %p, state %d", chan, control, skb, 7379 chan->rx_state); 7380 7381 if (l2cap_classify_txseq(chan, txseq) == L2CAP_TXSEQ_EXPECTED) { 7382 l2cap_pass_to_tx(chan, control); 7383 7384 BT_DBG("buffer_seq %u->%u", chan->buffer_seq, 7385 __next_seq(chan, chan->buffer_seq)); 7386 7387 chan->buffer_seq = __next_seq(chan, chan->buffer_seq); 7388 7389 l2cap_reassemble_sdu(chan, skb, control); 7390 } else { 7391 if (chan->sdu) { 7392 kfree_skb(chan->sdu); 7393 chan->sdu = NULL; 7394 } 7395 chan->sdu_last_frag = NULL; 7396 chan->sdu_len = 0; 7397 7398 if (skb) { 7399 BT_DBG("Freeing %p", skb); 7400 kfree_skb(skb); 7401 } 7402 } 7403 7404 chan->last_acked_seq = txseq; 7405 chan->expected_tx_seq = __next_seq(chan, txseq); 7406 7407 return 0; 7408 } 7409 7410 static int l2cap_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb) 7411 { 7412 struct l2cap_ctrl *control = &bt_cb(skb)->l2cap; 7413 u16 len; 7414 u8 event; 7415 7416 __unpack_control(chan, skb); 7417 7418 len = skb->len; 7419 7420 /* 7421 * We can just drop the corrupted I-frame here. 7422 * Receiver will miss it and start proper recovery 7423 * procedures and ask for retransmission. 7424 */ 7425 if (l2cap_check_fcs(chan, skb)) 7426 goto drop; 7427 7428 if (!control->sframe && control->sar == L2CAP_SAR_START) 7429 len -= L2CAP_SDULEN_SIZE; 7430 7431 if (chan->fcs == L2CAP_FCS_CRC16) 7432 len -= L2CAP_FCS_SIZE; 7433 7434 if (len > chan->mps) { 7435 l2cap_send_disconn_req(chan, ECONNRESET); 7436 goto drop; 7437 } 7438 7439 if (chan->ops->filter) { 7440 if (chan->ops->filter(chan, skb)) 7441 goto drop; 7442 } 7443 7444 if (!control->sframe) { 7445 int err; 7446 7447 BT_DBG("iframe sar %d, reqseq %d, final %d, txseq %d", 7448 control->sar, control->reqseq, control->final, 7449 control->txseq); 7450 7451 /* Validate F-bit - F=0 always valid, F=1 only 7452 * valid in TX WAIT_F 7453 */ 7454 if (control->final && chan->tx_state != L2CAP_TX_STATE_WAIT_F) 7455 goto drop; 7456 7457 if (chan->mode != L2CAP_MODE_STREAMING) { 7458 event = L2CAP_EV_RECV_IFRAME; 7459 err = l2cap_rx(chan, control, skb, event); 7460 } else { 7461 err = l2cap_stream_rx(chan, control, skb); 7462 } 7463 7464 if (err) 7465 l2cap_send_disconn_req(chan, ECONNRESET); 7466 } else { 7467 const u8 rx_func_to_event[4] = { 7468 L2CAP_EV_RECV_RR, L2CAP_EV_RECV_REJ, 7469 L2CAP_EV_RECV_RNR, L2CAP_EV_RECV_SREJ 7470 }; 7471 7472 /* Only I-frames are expected in streaming mode */ 7473 if (chan->mode == L2CAP_MODE_STREAMING) 7474 goto drop; 7475 7476 BT_DBG("sframe reqseq %d, final %d, poll %d, super %d", 7477 control->reqseq, control->final, control->poll, 7478 control->super); 7479 7480 if (len != 0) { 7481 BT_ERR("Trailing bytes: %d in sframe", len); 7482 l2cap_send_disconn_req(chan, ECONNRESET); 7483 goto drop; 7484 } 7485 7486 /* Validate F and P bits */ 7487 if (control->final && (control->poll || 7488 chan->tx_state != L2CAP_TX_STATE_WAIT_F)) 7489 goto drop; 7490 7491 event = rx_func_to_event[control->super]; 7492 if (l2cap_rx(chan, control, skb, event)) 7493 l2cap_send_disconn_req(chan, ECONNRESET); 7494 } 7495 7496 return 0; 7497 7498 drop: 7499 kfree_skb(skb); 7500 return 0; 7501 } 7502 7503 static void l2cap_chan_le_send_credits(struct l2cap_chan *chan) 7504 { 7505 struct l2cap_conn *conn = chan->conn; 7506 struct l2cap_le_credits pkt; 7507 u16 return_credits; 7508 7509 return_credits = (chan->imtu / chan->mps) + 1; 7510 7511 if (chan->rx_credits >= return_credits) 7512 return; 7513 7514 return_credits -= chan->rx_credits; 7515 7516 BT_DBG("chan %p returning %u credits to sender", chan, return_credits); 7517 7518 chan->rx_credits += return_credits; 7519 7520 pkt.cid = cpu_to_le16(chan->scid); 7521 pkt.credits = cpu_to_le16(return_credits); 7522 7523 chan->ident = l2cap_get_ident(conn); 7524 7525 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CREDITS, sizeof(pkt), &pkt); 7526 } 7527 7528 static int l2cap_ecred_recv(struct l2cap_chan *chan, struct sk_buff *skb) 7529 { 7530 int err; 7531 7532 BT_DBG("SDU reassemble complete: chan %p skb->len %u", chan, skb->len); 7533 7534 /* Wait recv to confirm reception before updating the credits */ 7535 err = chan->ops->recv(chan, skb); 7536 7537 /* Update credits whenever an SDU is received */ 7538 l2cap_chan_le_send_credits(chan); 7539 7540 return err; 7541 } 7542 7543 static int l2cap_ecred_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb) 7544 { 7545 int err; 7546 7547 if (!chan->rx_credits) { 7548 BT_ERR("No credits to receive LE L2CAP data"); 7549 l2cap_send_disconn_req(chan, ECONNRESET); 7550 return -ENOBUFS; 7551 } 7552 7553 if (chan->imtu < skb->len) { 7554 BT_ERR("Too big LE L2CAP PDU"); 7555 return -ENOBUFS; 7556 } 7557 7558 chan->rx_credits--; 7559 BT_DBG("rx_credits %u -> %u", chan->rx_credits + 1, chan->rx_credits); 7560 7561 /* Update if remote had run out of credits, this should only happens 7562 * if the remote is not using the entire MPS. 7563 */ 7564 if (!chan->rx_credits) 7565 l2cap_chan_le_send_credits(chan); 7566 7567 err = 0; 7568 7569 if (!chan->sdu) { 7570 u16 sdu_len; 7571 7572 sdu_len = get_unaligned_le16(skb->data); 7573 skb_pull(skb, L2CAP_SDULEN_SIZE); 7574 7575 BT_DBG("Start of new SDU. sdu_len %u skb->len %u imtu %u", 7576 sdu_len, skb->len, chan->imtu); 7577 7578 if (sdu_len > chan->imtu) { 7579 BT_ERR("Too big LE L2CAP SDU length received"); 7580 err = -EMSGSIZE; 7581 goto failed; 7582 } 7583 7584 if (skb->len > sdu_len) { 7585 BT_ERR("Too much LE L2CAP data received"); 7586 err = -EINVAL; 7587 goto failed; 7588 } 7589 7590 if (skb->len == sdu_len) 7591 return l2cap_ecred_recv(chan, skb); 7592 7593 chan->sdu = skb; 7594 chan->sdu_len = sdu_len; 7595 chan->sdu_last_frag = skb; 7596 7597 /* Detect if remote is not able to use the selected MPS */ 7598 if (skb->len + L2CAP_SDULEN_SIZE < chan->mps) { 7599 u16 mps_len = skb->len + L2CAP_SDULEN_SIZE; 7600 7601 /* Adjust the number of credits */ 7602 BT_DBG("chan->mps %u -> %u", chan->mps, mps_len); 7603 chan->mps = mps_len; 7604 l2cap_chan_le_send_credits(chan); 7605 } 7606 7607 return 0; 7608 } 7609 7610 BT_DBG("SDU fragment. chan->sdu->len %u skb->len %u chan->sdu_len %u", 7611 chan->sdu->len, skb->len, chan->sdu_len); 7612 7613 if (chan->sdu->len + skb->len > chan->sdu_len) { 7614 BT_ERR("Too much LE L2CAP data received"); 7615 err = -EINVAL; 7616 goto failed; 7617 } 7618 7619 append_skb_frag(chan->sdu, skb, &chan->sdu_last_frag); 7620 skb = NULL; 7621 7622 if (chan->sdu->len == chan->sdu_len) { 7623 err = l2cap_ecred_recv(chan, chan->sdu); 7624 if (!err) { 7625 chan->sdu = NULL; 7626 chan->sdu_last_frag = NULL; 7627 chan->sdu_len = 0; 7628 } 7629 } 7630 7631 failed: 7632 if (err) { 7633 kfree_skb(skb); 7634 kfree_skb(chan->sdu); 7635 chan->sdu = NULL; 7636 chan->sdu_last_frag = NULL; 7637 chan->sdu_len = 0; 7638 } 7639 7640 /* We can't return an error here since we took care of the skb 7641 * freeing internally. An error return would cause the caller to 7642 * do a double-free of the skb. 7643 */ 7644 return 0; 7645 } 7646 7647 static void l2cap_data_channel(struct l2cap_conn *conn, u16 cid, 7648 struct sk_buff *skb) 7649 { 7650 struct l2cap_chan *chan; 7651 7652 chan = l2cap_get_chan_by_scid(conn, cid); 7653 if (!chan) { 7654 if (cid == L2CAP_CID_A2MP) { 7655 chan = a2mp_channel_create(conn, skb); 7656 if (!chan) { 7657 kfree_skb(skb); 7658 return; 7659 } 7660 7661 l2cap_chan_hold(chan); 7662 l2cap_chan_lock(chan); 7663 } else { 7664 BT_DBG("unknown cid 0x%4.4x", cid); 7665 /* Drop packet and return */ 7666 kfree_skb(skb); 7667 return; 7668 } 7669 } 7670 7671 BT_DBG("chan %p, len %d", chan, skb->len); 7672 7673 /* If we receive data on a fixed channel before the info req/rsp 7674 * procedure is done simply assume that the channel is supported 7675 * and mark it as ready. 7676 */ 7677 if (chan->chan_type == L2CAP_CHAN_FIXED) 7678 l2cap_chan_ready(chan); 7679 7680 if (chan->state != BT_CONNECTED) 7681 goto drop; 7682 7683 switch (chan->mode) { 7684 case L2CAP_MODE_LE_FLOWCTL: 7685 case L2CAP_MODE_EXT_FLOWCTL: 7686 if (l2cap_ecred_data_rcv(chan, skb) < 0) 7687 goto drop; 7688 7689 goto done; 7690 7691 case L2CAP_MODE_BASIC: 7692 /* If socket recv buffers overflows we drop data here 7693 * which is *bad* because L2CAP has to be reliable. 7694 * But we don't have any other choice. L2CAP doesn't 7695 * provide flow control mechanism. */ 7696 7697 if (chan->imtu < skb->len) { 7698 BT_ERR("Dropping L2CAP data: receive buffer overflow"); 7699 goto drop; 7700 } 7701 7702 if (!chan->ops->recv(chan, skb)) 7703 goto done; 7704 break; 7705 7706 case L2CAP_MODE_ERTM: 7707 case L2CAP_MODE_STREAMING: 7708 l2cap_data_rcv(chan, skb); 7709 goto done; 7710 7711 default: 7712 BT_DBG("chan %p: bad mode 0x%2.2x", chan, chan->mode); 7713 break; 7714 } 7715 7716 drop: 7717 kfree_skb(skb); 7718 7719 done: 7720 l2cap_chan_unlock(chan); 7721 l2cap_chan_put(chan); 7722 } 7723 7724 static void l2cap_conless_channel(struct l2cap_conn *conn, __le16 psm, 7725 struct sk_buff *skb) 7726 { 7727 struct hci_conn *hcon = conn->hcon; 7728 struct l2cap_chan *chan; 7729 7730 if (hcon->type != ACL_LINK) 7731 goto free_skb; 7732 7733 chan = l2cap_global_chan_by_psm(0, psm, &hcon->src, &hcon->dst, 7734 ACL_LINK); 7735 if (!chan) 7736 goto free_skb; 7737 7738 BT_DBG("chan %p, len %d", chan, skb->len); 7739 7740 if (chan->state != BT_BOUND && chan->state != BT_CONNECTED) 7741 goto drop; 7742 7743 if (chan->imtu < skb->len) 7744 goto drop; 7745 7746 /* Store remote BD_ADDR and PSM for msg_name */ 7747 bacpy(&bt_cb(skb)->l2cap.bdaddr, &hcon->dst); 7748 bt_cb(skb)->l2cap.psm = psm; 7749 7750 if (!chan->ops->recv(chan, skb)) { 7751 l2cap_chan_put(chan); 7752 return; 7753 } 7754 7755 drop: 7756 l2cap_chan_put(chan); 7757 free_skb: 7758 kfree_skb(skb); 7759 } 7760 7761 static void l2cap_recv_frame(struct l2cap_conn *conn, struct sk_buff *skb) 7762 { 7763 struct l2cap_hdr *lh = (void *) skb->data; 7764 struct hci_conn *hcon = conn->hcon; 7765 u16 cid, len; 7766 __le16 psm; 7767 7768 if (hcon->state != BT_CONNECTED) { 7769 BT_DBG("queueing pending rx skb"); 7770 skb_queue_tail(&conn->pending_rx, skb); 7771 return; 7772 } 7773 7774 skb_pull(skb, L2CAP_HDR_SIZE); 7775 cid = __le16_to_cpu(lh->cid); 7776 len = __le16_to_cpu(lh->len); 7777 7778 if (len != skb->len) { 7779 kfree_skb(skb); 7780 return; 7781 } 7782 7783 /* Since we can't actively block incoming LE connections we must 7784 * at least ensure that we ignore incoming data from them. 7785 */ 7786 if (hcon->type == LE_LINK && 7787 hci_bdaddr_list_lookup(&hcon->hdev->reject_list, &hcon->dst, 7788 bdaddr_dst_type(hcon))) { 7789 kfree_skb(skb); 7790 return; 7791 } 7792 7793 BT_DBG("len %d, cid 0x%4.4x", len, cid); 7794 7795 switch (cid) { 7796 case L2CAP_CID_SIGNALING: 7797 l2cap_sig_channel(conn, skb); 7798 break; 7799 7800 case L2CAP_CID_CONN_LESS: 7801 psm = get_unaligned((__le16 *) skb->data); 7802 skb_pull(skb, L2CAP_PSMLEN_SIZE); 7803 l2cap_conless_channel(conn, psm, skb); 7804 break; 7805 7806 case L2CAP_CID_LE_SIGNALING: 7807 l2cap_le_sig_channel(conn, skb); 7808 break; 7809 7810 default: 7811 l2cap_data_channel(conn, cid, skb); 7812 break; 7813 } 7814 } 7815 7816 static void process_pending_rx(struct work_struct *work) 7817 { 7818 struct l2cap_conn *conn = container_of(work, struct l2cap_conn, 7819 pending_rx_work); 7820 struct sk_buff *skb; 7821 7822 BT_DBG(""); 7823 7824 while ((skb = skb_dequeue(&conn->pending_rx))) 7825 l2cap_recv_frame(conn, skb); 7826 } 7827 7828 static struct l2cap_conn *l2cap_conn_add(struct hci_conn *hcon) 7829 { 7830 struct l2cap_conn *conn = hcon->l2cap_data; 7831 struct hci_chan *hchan; 7832 7833 if (conn) 7834 return conn; 7835 7836 hchan = hci_chan_create(hcon); 7837 if (!hchan) 7838 return NULL; 7839 7840 conn = kzalloc(sizeof(*conn), GFP_KERNEL); 7841 if (!conn) { 7842 hci_chan_del(hchan); 7843 return NULL; 7844 } 7845 7846 kref_init(&conn->ref); 7847 hcon->l2cap_data = conn; 7848 conn->hcon = hci_conn_get(hcon); 7849 conn->hchan = hchan; 7850 7851 BT_DBG("hcon %p conn %p hchan %p", hcon, conn, hchan); 7852 7853 switch (hcon->type) { 7854 case LE_LINK: 7855 if (hcon->hdev->le_mtu) { 7856 conn->mtu = hcon->hdev->le_mtu; 7857 break; 7858 } 7859 fallthrough; 7860 default: 7861 conn->mtu = hcon->hdev->acl_mtu; 7862 break; 7863 } 7864 7865 conn->feat_mask = 0; 7866 7867 conn->local_fixed_chan = L2CAP_FC_SIG_BREDR | L2CAP_FC_CONNLESS; 7868 7869 if (hcon->type == ACL_LINK && 7870 hci_dev_test_flag(hcon->hdev, HCI_HS_ENABLED)) 7871 conn->local_fixed_chan |= L2CAP_FC_A2MP; 7872 7873 if (hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED) && 7874 (bredr_sc_enabled(hcon->hdev) || 7875 hci_dev_test_flag(hcon->hdev, HCI_FORCE_BREDR_SMP))) 7876 conn->local_fixed_chan |= L2CAP_FC_SMP_BREDR; 7877 7878 mutex_init(&conn->ident_lock); 7879 mutex_init(&conn->chan_lock); 7880 7881 INIT_LIST_HEAD(&conn->chan_l); 7882 INIT_LIST_HEAD(&conn->users); 7883 7884 INIT_DELAYED_WORK(&conn->info_timer, l2cap_info_timeout); 7885 7886 skb_queue_head_init(&conn->pending_rx); 7887 INIT_WORK(&conn->pending_rx_work, process_pending_rx); 7888 INIT_DELAYED_WORK(&conn->id_addr_timer, l2cap_conn_update_id_addr); 7889 7890 conn->disc_reason = HCI_ERROR_REMOTE_USER_TERM; 7891 7892 return conn; 7893 } 7894 7895 static bool is_valid_psm(u16 psm, u8 dst_type) 7896 { 7897 if (!psm) 7898 return false; 7899 7900 if (bdaddr_type_is_le(dst_type)) 7901 return (psm <= 0x00ff); 7902 7903 /* PSM must be odd and lsb of upper byte must be 0 */ 7904 return ((psm & 0x0101) == 0x0001); 7905 } 7906 7907 struct l2cap_chan_data { 7908 struct l2cap_chan *chan; 7909 struct pid *pid; 7910 int count; 7911 }; 7912 7913 static void l2cap_chan_by_pid(struct l2cap_chan *chan, void *data) 7914 { 7915 struct l2cap_chan_data *d = data; 7916 struct pid *pid; 7917 7918 if (chan == d->chan) 7919 return; 7920 7921 if (!test_bit(FLAG_DEFER_SETUP, &chan->flags)) 7922 return; 7923 7924 pid = chan->ops->get_peer_pid(chan); 7925 7926 /* Only count deferred channels with the same PID/PSM */ 7927 if (d->pid != pid || chan->psm != d->chan->psm || chan->ident || 7928 chan->mode != L2CAP_MODE_EXT_FLOWCTL || chan->state != BT_CONNECT) 7929 return; 7930 7931 d->count++; 7932 } 7933 7934 int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid, 7935 bdaddr_t *dst, u8 dst_type) 7936 { 7937 struct l2cap_conn *conn; 7938 struct hci_conn *hcon; 7939 struct hci_dev *hdev; 7940 int err; 7941 7942 BT_DBG("%pMR -> %pMR (type %u) psm 0x%4.4x mode 0x%2.2x", &chan->src, 7943 dst, dst_type, __le16_to_cpu(psm), chan->mode); 7944 7945 hdev = hci_get_route(dst, &chan->src, chan->src_type); 7946 if (!hdev) 7947 return -EHOSTUNREACH; 7948 7949 hci_dev_lock(hdev); 7950 7951 if (!is_valid_psm(__le16_to_cpu(psm), dst_type) && !cid && 7952 chan->chan_type != L2CAP_CHAN_RAW) { 7953 err = -EINVAL; 7954 goto done; 7955 } 7956 7957 if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED && !psm) { 7958 err = -EINVAL; 7959 goto done; 7960 } 7961 7962 if (chan->chan_type == L2CAP_CHAN_FIXED && !cid) { 7963 err = -EINVAL; 7964 goto done; 7965 } 7966 7967 switch (chan->mode) { 7968 case L2CAP_MODE_BASIC: 7969 break; 7970 case L2CAP_MODE_LE_FLOWCTL: 7971 break; 7972 case L2CAP_MODE_EXT_FLOWCTL: 7973 if (!enable_ecred) { 7974 err = -EOPNOTSUPP; 7975 goto done; 7976 } 7977 break; 7978 case L2CAP_MODE_ERTM: 7979 case L2CAP_MODE_STREAMING: 7980 if (!disable_ertm) 7981 break; 7982 fallthrough; 7983 default: 7984 err = -EOPNOTSUPP; 7985 goto done; 7986 } 7987 7988 switch (chan->state) { 7989 case BT_CONNECT: 7990 case BT_CONNECT2: 7991 case BT_CONFIG: 7992 /* Already connecting */ 7993 err = 0; 7994 goto done; 7995 7996 case BT_CONNECTED: 7997 /* Already connected */ 7998 err = -EISCONN; 7999 goto done; 8000 8001 case BT_OPEN: 8002 case BT_BOUND: 8003 /* Can connect */ 8004 break; 8005 8006 default: 8007 err = -EBADFD; 8008 goto done; 8009 } 8010 8011 /* Set destination address and psm */ 8012 bacpy(&chan->dst, dst); 8013 chan->dst_type = dst_type; 8014 8015 chan->psm = psm; 8016 chan->dcid = cid; 8017 8018 if (bdaddr_type_is_le(dst_type)) { 8019 /* Convert from L2CAP channel address type to HCI address type 8020 */ 8021 if (dst_type == BDADDR_LE_PUBLIC) 8022 dst_type = ADDR_LE_DEV_PUBLIC; 8023 else 8024 dst_type = ADDR_LE_DEV_RANDOM; 8025 8026 if (hci_dev_test_flag(hdev, HCI_ADVERTISING)) 8027 hcon = hci_connect_le(hdev, dst, dst_type, false, 8028 chan->sec_level, 8029 HCI_LE_CONN_TIMEOUT, 8030 HCI_ROLE_SLAVE); 8031 else 8032 hcon = hci_connect_le_scan(hdev, dst, dst_type, 8033 chan->sec_level, 8034 HCI_LE_CONN_TIMEOUT, 8035 CONN_REASON_L2CAP_CHAN); 8036 8037 } else { 8038 u8 auth_type = l2cap_get_auth_type(chan); 8039 hcon = hci_connect_acl(hdev, dst, chan->sec_level, auth_type, 8040 CONN_REASON_L2CAP_CHAN); 8041 } 8042 8043 if (IS_ERR(hcon)) { 8044 err = PTR_ERR(hcon); 8045 goto done; 8046 } 8047 8048 conn = l2cap_conn_add(hcon); 8049 if (!conn) { 8050 hci_conn_drop(hcon); 8051 err = -ENOMEM; 8052 goto done; 8053 } 8054 8055 if (chan->mode == L2CAP_MODE_EXT_FLOWCTL) { 8056 struct l2cap_chan_data data; 8057 8058 data.chan = chan; 8059 data.pid = chan->ops->get_peer_pid(chan); 8060 data.count = 1; 8061 8062 l2cap_chan_list(conn, l2cap_chan_by_pid, &data); 8063 8064 /* Check if there isn't too many channels being connected */ 8065 if (data.count > L2CAP_ECRED_CONN_SCID_MAX) { 8066 hci_conn_drop(hcon); 8067 err = -EPROTO; 8068 goto done; 8069 } 8070 } 8071 8072 mutex_lock(&conn->chan_lock); 8073 l2cap_chan_lock(chan); 8074 8075 if (cid && __l2cap_get_chan_by_dcid(conn, cid)) { 8076 hci_conn_drop(hcon); 8077 err = -EBUSY; 8078 goto chan_unlock; 8079 } 8080 8081 /* Update source addr of the socket */ 8082 bacpy(&chan->src, &hcon->src); 8083 chan->src_type = bdaddr_src_type(hcon); 8084 8085 __l2cap_chan_add(conn, chan); 8086 8087 /* l2cap_chan_add takes its own ref so we can drop this one */ 8088 hci_conn_drop(hcon); 8089 8090 l2cap_state_change(chan, BT_CONNECT); 8091 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan)); 8092 8093 /* Release chan->sport so that it can be reused by other 8094 * sockets (as it's only used for listening sockets). 8095 */ 8096 write_lock(&chan_list_lock); 8097 chan->sport = 0; 8098 write_unlock(&chan_list_lock); 8099 8100 if (hcon->state == BT_CONNECTED) { 8101 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) { 8102 __clear_chan_timer(chan); 8103 if (l2cap_chan_check_security(chan, true)) 8104 l2cap_state_change(chan, BT_CONNECTED); 8105 } else 8106 l2cap_do_start(chan); 8107 } 8108 8109 err = 0; 8110 8111 chan_unlock: 8112 l2cap_chan_unlock(chan); 8113 mutex_unlock(&conn->chan_lock); 8114 done: 8115 hci_dev_unlock(hdev); 8116 hci_dev_put(hdev); 8117 return err; 8118 } 8119 EXPORT_SYMBOL_GPL(l2cap_chan_connect); 8120 8121 static void l2cap_ecred_reconfigure(struct l2cap_chan *chan) 8122 { 8123 struct l2cap_conn *conn = chan->conn; 8124 struct { 8125 struct l2cap_ecred_reconf_req req; 8126 __le16 scid; 8127 } pdu; 8128 8129 pdu.req.mtu = cpu_to_le16(chan->imtu); 8130 pdu.req.mps = cpu_to_le16(chan->mps); 8131 pdu.scid = cpu_to_le16(chan->scid); 8132 8133 chan->ident = l2cap_get_ident(conn); 8134 8135 l2cap_send_cmd(conn, chan->ident, L2CAP_ECRED_RECONF_REQ, 8136 sizeof(pdu), &pdu); 8137 } 8138 8139 int l2cap_chan_reconfigure(struct l2cap_chan *chan, __u16 mtu) 8140 { 8141 if (chan->imtu > mtu) 8142 return -EINVAL; 8143 8144 BT_DBG("chan %p mtu 0x%4.4x", chan, mtu); 8145 8146 chan->imtu = mtu; 8147 8148 l2cap_ecred_reconfigure(chan); 8149 8150 return 0; 8151 } 8152 8153 /* ---- L2CAP interface with lower layer (HCI) ---- */ 8154 8155 int l2cap_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr) 8156 { 8157 int exact = 0, lm1 = 0, lm2 = 0; 8158 struct l2cap_chan *c; 8159 8160 BT_DBG("hdev %s, bdaddr %pMR", hdev->name, bdaddr); 8161 8162 /* Find listening sockets and check their link_mode */ 8163 read_lock(&chan_list_lock); 8164 list_for_each_entry(c, &chan_list, global_l) { 8165 if (c->state != BT_LISTEN) 8166 continue; 8167 8168 if (!bacmp(&c->src, &hdev->bdaddr)) { 8169 lm1 |= HCI_LM_ACCEPT; 8170 if (test_bit(FLAG_ROLE_SWITCH, &c->flags)) 8171 lm1 |= HCI_LM_MASTER; 8172 exact++; 8173 } else if (!bacmp(&c->src, BDADDR_ANY)) { 8174 lm2 |= HCI_LM_ACCEPT; 8175 if (test_bit(FLAG_ROLE_SWITCH, &c->flags)) 8176 lm2 |= HCI_LM_MASTER; 8177 } 8178 } 8179 read_unlock(&chan_list_lock); 8180 8181 return exact ? lm1 : lm2; 8182 } 8183 8184 /* Find the next fixed channel in BT_LISTEN state, continue iteration 8185 * from an existing channel in the list or from the beginning of the 8186 * global list (by passing NULL as first parameter). 8187 */ 8188 static struct l2cap_chan *l2cap_global_fixed_chan(struct l2cap_chan *c, 8189 struct hci_conn *hcon) 8190 { 8191 u8 src_type = bdaddr_src_type(hcon); 8192 8193 read_lock(&chan_list_lock); 8194 8195 if (c) 8196 c = list_next_entry(c, global_l); 8197 else 8198 c = list_entry(chan_list.next, typeof(*c), global_l); 8199 8200 list_for_each_entry_from(c, &chan_list, global_l) { 8201 if (c->chan_type != L2CAP_CHAN_FIXED) 8202 continue; 8203 if (c->state != BT_LISTEN) 8204 continue; 8205 if (bacmp(&c->src, &hcon->src) && bacmp(&c->src, BDADDR_ANY)) 8206 continue; 8207 if (src_type != c->src_type) 8208 continue; 8209 8210 c = l2cap_chan_hold_unless_zero(c); 8211 read_unlock(&chan_list_lock); 8212 return c; 8213 } 8214 8215 read_unlock(&chan_list_lock); 8216 8217 return NULL; 8218 } 8219 8220 static void l2cap_connect_cfm(struct hci_conn *hcon, u8 status) 8221 { 8222 struct hci_dev *hdev = hcon->hdev; 8223 struct l2cap_conn *conn; 8224 struct l2cap_chan *pchan; 8225 u8 dst_type; 8226 8227 if (hcon->type != ACL_LINK && hcon->type != LE_LINK) 8228 return; 8229 8230 BT_DBG("hcon %p bdaddr %pMR status %d", hcon, &hcon->dst, status); 8231 8232 if (status) { 8233 l2cap_conn_del(hcon, bt_to_errno(status)); 8234 return; 8235 } 8236 8237 conn = l2cap_conn_add(hcon); 8238 if (!conn) 8239 return; 8240 8241 dst_type = bdaddr_dst_type(hcon); 8242 8243 /* If device is blocked, do not create channels for it */ 8244 if (hci_bdaddr_list_lookup(&hdev->reject_list, &hcon->dst, dst_type)) 8245 return; 8246 8247 /* Find fixed channels and notify them of the new connection. We 8248 * use multiple individual lookups, continuing each time where 8249 * we left off, because the list lock would prevent calling the 8250 * potentially sleeping l2cap_chan_lock() function. 8251 */ 8252 pchan = l2cap_global_fixed_chan(NULL, hcon); 8253 while (pchan) { 8254 struct l2cap_chan *chan, *next; 8255 8256 /* Client fixed channels should override server ones */ 8257 if (__l2cap_get_chan_by_dcid(conn, pchan->scid)) 8258 goto next; 8259 8260 l2cap_chan_lock(pchan); 8261 chan = pchan->ops->new_connection(pchan); 8262 if (chan) { 8263 bacpy(&chan->src, &hcon->src); 8264 bacpy(&chan->dst, &hcon->dst); 8265 chan->src_type = bdaddr_src_type(hcon); 8266 chan->dst_type = dst_type; 8267 8268 __l2cap_chan_add(conn, chan); 8269 } 8270 8271 l2cap_chan_unlock(pchan); 8272 next: 8273 next = l2cap_global_fixed_chan(pchan, hcon); 8274 l2cap_chan_put(pchan); 8275 pchan = next; 8276 } 8277 8278 l2cap_conn_ready(conn); 8279 } 8280 8281 int l2cap_disconn_ind(struct hci_conn *hcon) 8282 { 8283 struct l2cap_conn *conn = hcon->l2cap_data; 8284 8285 BT_DBG("hcon %p", hcon); 8286 8287 if (!conn) 8288 return HCI_ERROR_REMOTE_USER_TERM; 8289 return conn->disc_reason; 8290 } 8291 8292 static void l2cap_disconn_cfm(struct hci_conn *hcon, u8 reason) 8293 { 8294 if (hcon->type != ACL_LINK && hcon->type != LE_LINK) 8295 return; 8296 8297 BT_DBG("hcon %p reason %d", hcon, reason); 8298 8299 l2cap_conn_del(hcon, bt_to_errno(reason)); 8300 } 8301 8302 static inline void l2cap_check_encryption(struct l2cap_chan *chan, u8 encrypt) 8303 { 8304 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) 8305 return; 8306 8307 if (encrypt == 0x00) { 8308 if (chan->sec_level == BT_SECURITY_MEDIUM) { 8309 __set_chan_timer(chan, L2CAP_ENC_TIMEOUT); 8310 } else if (chan->sec_level == BT_SECURITY_HIGH || 8311 chan->sec_level == BT_SECURITY_FIPS) 8312 l2cap_chan_close(chan, ECONNREFUSED); 8313 } else { 8314 if (chan->sec_level == BT_SECURITY_MEDIUM) 8315 __clear_chan_timer(chan); 8316 } 8317 } 8318 8319 static void l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt) 8320 { 8321 struct l2cap_conn *conn = hcon->l2cap_data; 8322 struct l2cap_chan *chan; 8323 8324 if (!conn) 8325 return; 8326 8327 BT_DBG("conn %p status 0x%2.2x encrypt %u", conn, status, encrypt); 8328 8329 mutex_lock(&conn->chan_lock); 8330 8331 list_for_each_entry(chan, &conn->chan_l, list) { 8332 l2cap_chan_lock(chan); 8333 8334 BT_DBG("chan %p scid 0x%4.4x state %s", chan, chan->scid, 8335 state_to_string(chan->state)); 8336 8337 if (chan->scid == L2CAP_CID_A2MP) { 8338 l2cap_chan_unlock(chan); 8339 continue; 8340 } 8341 8342 if (!status && encrypt) 8343 chan->sec_level = hcon->sec_level; 8344 8345 if (!__l2cap_no_conn_pending(chan)) { 8346 l2cap_chan_unlock(chan); 8347 continue; 8348 } 8349 8350 if (!status && (chan->state == BT_CONNECTED || 8351 chan->state == BT_CONFIG)) { 8352 chan->ops->resume(chan); 8353 l2cap_check_encryption(chan, encrypt); 8354 l2cap_chan_unlock(chan); 8355 continue; 8356 } 8357 8358 if (chan->state == BT_CONNECT) { 8359 if (!status && l2cap_check_enc_key_size(hcon)) 8360 l2cap_start_connection(chan); 8361 else 8362 __set_chan_timer(chan, L2CAP_DISC_TIMEOUT); 8363 } else if (chan->state == BT_CONNECT2 && 8364 !(chan->mode == L2CAP_MODE_EXT_FLOWCTL || 8365 chan->mode == L2CAP_MODE_LE_FLOWCTL)) { 8366 struct l2cap_conn_rsp rsp; 8367 __u16 res, stat; 8368 8369 if (!status && l2cap_check_enc_key_size(hcon)) { 8370 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) { 8371 res = L2CAP_CR_PEND; 8372 stat = L2CAP_CS_AUTHOR_PEND; 8373 chan->ops->defer(chan); 8374 } else { 8375 l2cap_state_change(chan, BT_CONFIG); 8376 res = L2CAP_CR_SUCCESS; 8377 stat = L2CAP_CS_NO_INFO; 8378 } 8379 } else { 8380 l2cap_state_change(chan, BT_DISCONN); 8381 __set_chan_timer(chan, L2CAP_DISC_TIMEOUT); 8382 res = L2CAP_CR_SEC_BLOCK; 8383 stat = L2CAP_CS_NO_INFO; 8384 } 8385 8386 rsp.scid = cpu_to_le16(chan->dcid); 8387 rsp.dcid = cpu_to_le16(chan->scid); 8388 rsp.result = cpu_to_le16(res); 8389 rsp.status = cpu_to_le16(stat); 8390 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP, 8391 sizeof(rsp), &rsp); 8392 8393 if (!test_bit(CONF_REQ_SENT, &chan->conf_state) && 8394 res == L2CAP_CR_SUCCESS) { 8395 char buf[128]; 8396 set_bit(CONF_REQ_SENT, &chan->conf_state); 8397 l2cap_send_cmd(conn, l2cap_get_ident(conn), 8398 L2CAP_CONF_REQ, 8399 l2cap_build_conf_req(chan, buf, sizeof(buf)), 8400 buf); 8401 chan->num_conf_req++; 8402 } 8403 } 8404 8405 l2cap_chan_unlock(chan); 8406 } 8407 8408 mutex_unlock(&conn->chan_lock); 8409 } 8410 8411 /* Append fragment into frame respecting the maximum len of rx_skb */ 8412 static int l2cap_recv_frag(struct l2cap_conn *conn, struct sk_buff *skb, 8413 u16 len) 8414 { 8415 if (!conn->rx_skb) { 8416 /* Allocate skb for the complete frame (with header) */ 8417 conn->rx_skb = bt_skb_alloc(len, GFP_KERNEL); 8418 if (!conn->rx_skb) 8419 return -ENOMEM; 8420 /* Init rx_len */ 8421 conn->rx_len = len; 8422 } 8423 8424 /* Copy as much as the rx_skb can hold */ 8425 len = min_t(u16, len, skb->len); 8426 skb_copy_from_linear_data(skb, skb_put(conn->rx_skb, len), len); 8427 skb_pull(skb, len); 8428 conn->rx_len -= len; 8429 8430 return len; 8431 } 8432 8433 static int l2cap_recv_len(struct l2cap_conn *conn, struct sk_buff *skb) 8434 { 8435 struct sk_buff *rx_skb; 8436 int len; 8437 8438 /* Append just enough to complete the header */ 8439 len = l2cap_recv_frag(conn, skb, L2CAP_LEN_SIZE - conn->rx_skb->len); 8440 8441 /* If header could not be read just continue */ 8442 if (len < 0 || conn->rx_skb->len < L2CAP_LEN_SIZE) 8443 return len; 8444 8445 rx_skb = conn->rx_skb; 8446 len = get_unaligned_le16(rx_skb->data); 8447 8448 /* Check if rx_skb has enough space to received all fragments */ 8449 if (len + (L2CAP_HDR_SIZE - L2CAP_LEN_SIZE) <= skb_tailroom(rx_skb)) { 8450 /* Update expected len */ 8451 conn->rx_len = len + (L2CAP_HDR_SIZE - L2CAP_LEN_SIZE); 8452 return L2CAP_LEN_SIZE; 8453 } 8454 8455 /* Reset conn->rx_skb since it will need to be reallocated in order to 8456 * fit all fragments. 8457 */ 8458 conn->rx_skb = NULL; 8459 8460 /* Reallocates rx_skb using the exact expected length */ 8461 len = l2cap_recv_frag(conn, rx_skb, 8462 len + (L2CAP_HDR_SIZE - L2CAP_LEN_SIZE)); 8463 kfree_skb(rx_skb); 8464 8465 return len; 8466 } 8467 8468 static void l2cap_recv_reset(struct l2cap_conn *conn) 8469 { 8470 kfree_skb(conn->rx_skb); 8471 conn->rx_skb = NULL; 8472 conn->rx_len = 0; 8473 } 8474 8475 void l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 flags) 8476 { 8477 struct l2cap_conn *conn = hcon->l2cap_data; 8478 int len; 8479 8480 /* For AMP controller do not create l2cap conn */ 8481 if (!conn && hcon->hdev->dev_type != HCI_PRIMARY) 8482 goto drop; 8483 8484 if (!conn) 8485 conn = l2cap_conn_add(hcon); 8486 8487 if (!conn) 8488 goto drop; 8489 8490 BT_DBG("conn %p len %u flags 0x%x", conn, skb->len, flags); 8491 8492 switch (flags) { 8493 case ACL_START: 8494 case ACL_START_NO_FLUSH: 8495 case ACL_COMPLETE: 8496 if (conn->rx_skb) { 8497 BT_ERR("Unexpected start frame (len %d)", skb->len); 8498 l2cap_recv_reset(conn); 8499 l2cap_conn_unreliable(conn, ECOMM); 8500 } 8501 8502 /* Start fragment may not contain the L2CAP length so just 8503 * copy the initial byte when that happens and use conn->mtu as 8504 * expected length. 8505 */ 8506 if (skb->len < L2CAP_LEN_SIZE) { 8507 l2cap_recv_frag(conn, skb, conn->mtu); 8508 break; 8509 } 8510 8511 len = get_unaligned_le16(skb->data) + L2CAP_HDR_SIZE; 8512 8513 if (len == skb->len) { 8514 /* Complete frame received */ 8515 l2cap_recv_frame(conn, skb); 8516 return; 8517 } 8518 8519 BT_DBG("Start: total len %d, frag len %u", len, skb->len); 8520 8521 if (skb->len > len) { 8522 BT_ERR("Frame is too long (len %u, expected len %d)", 8523 skb->len, len); 8524 l2cap_conn_unreliable(conn, ECOMM); 8525 goto drop; 8526 } 8527 8528 /* Append fragment into frame (with header) */ 8529 if (l2cap_recv_frag(conn, skb, len) < 0) 8530 goto drop; 8531 8532 break; 8533 8534 case ACL_CONT: 8535 BT_DBG("Cont: frag len %u (expecting %u)", skb->len, conn->rx_len); 8536 8537 if (!conn->rx_skb) { 8538 BT_ERR("Unexpected continuation frame (len %d)", skb->len); 8539 l2cap_conn_unreliable(conn, ECOMM); 8540 goto drop; 8541 } 8542 8543 /* Complete the L2CAP length if it has not been read */ 8544 if (conn->rx_skb->len < L2CAP_LEN_SIZE) { 8545 if (l2cap_recv_len(conn, skb) < 0) { 8546 l2cap_conn_unreliable(conn, ECOMM); 8547 goto drop; 8548 } 8549 8550 /* Header still could not be read just continue */ 8551 if (conn->rx_skb->len < L2CAP_LEN_SIZE) 8552 break; 8553 } 8554 8555 if (skb->len > conn->rx_len) { 8556 BT_ERR("Fragment is too long (len %u, expected %u)", 8557 skb->len, conn->rx_len); 8558 l2cap_recv_reset(conn); 8559 l2cap_conn_unreliable(conn, ECOMM); 8560 goto drop; 8561 } 8562 8563 /* Append fragment into frame (with header) */ 8564 l2cap_recv_frag(conn, skb, skb->len); 8565 8566 if (!conn->rx_len) { 8567 /* Complete frame received. l2cap_recv_frame 8568 * takes ownership of the skb so set the global 8569 * rx_skb pointer to NULL first. 8570 */ 8571 struct sk_buff *rx_skb = conn->rx_skb; 8572 conn->rx_skb = NULL; 8573 l2cap_recv_frame(conn, rx_skb); 8574 } 8575 break; 8576 } 8577 8578 drop: 8579 kfree_skb(skb); 8580 } 8581 8582 static struct hci_cb l2cap_cb = { 8583 .name = "L2CAP", 8584 .connect_cfm = l2cap_connect_cfm, 8585 .disconn_cfm = l2cap_disconn_cfm, 8586 .security_cfm = l2cap_security_cfm, 8587 }; 8588 8589 static int l2cap_debugfs_show(struct seq_file *f, void *p) 8590 { 8591 struct l2cap_chan *c; 8592 8593 read_lock(&chan_list_lock); 8594 8595 list_for_each_entry(c, &chan_list, global_l) { 8596 seq_printf(f, "%pMR (%u) %pMR (%u) %d %d 0x%4.4x 0x%4.4x %d %d %d %d\n", 8597 &c->src, c->src_type, &c->dst, c->dst_type, 8598 c->state, __le16_to_cpu(c->psm), 8599 c->scid, c->dcid, c->imtu, c->omtu, 8600 c->sec_level, c->mode); 8601 } 8602 8603 read_unlock(&chan_list_lock); 8604 8605 return 0; 8606 } 8607 8608 DEFINE_SHOW_ATTRIBUTE(l2cap_debugfs); 8609 8610 static struct dentry *l2cap_debugfs; 8611 8612 int __init l2cap_init(void) 8613 { 8614 int err; 8615 8616 err = l2cap_init_sockets(); 8617 if (err < 0) 8618 return err; 8619 8620 hci_register_cb(&l2cap_cb); 8621 8622 if (IS_ERR_OR_NULL(bt_debugfs)) 8623 return 0; 8624 8625 l2cap_debugfs = debugfs_create_file("l2cap", 0444, bt_debugfs, 8626 NULL, &l2cap_debugfs_fops); 8627 8628 return 0; 8629 } 8630 8631 void l2cap_exit(void) 8632 { 8633 debugfs_remove(l2cap_debugfs); 8634 hci_unregister_cb(&l2cap_cb); 8635 l2cap_cleanup_sockets(); 8636 } 8637 8638 module_param(disable_ertm, bool, 0644); 8639 MODULE_PARM_DESC(disable_ertm, "Disable enhanced retransmission mode"); 8640 8641 module_param(enable_ecred, bool, 0644); 8642 MODULE_PARM_DESC(enable_ecred, "Enable enhanced credit flow control mode"); 8643