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