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 43 #define LE_FLOWCTL_MAX_CREDITS 65535 44 45 bool disable_ertm; 46 bool enable_ecred = IS_ENABLED(CONFIG_BT_LE_L2CAP_ECRED); 47 48 static u32 l2cap_feat_mask = L2CAP_FEAT_FIXED_CHAN | L2CAP_FEAT_UCD; 49 50 static LIST_HEAD(chan_list); 51 static DEFINE_RWLOCK(chan_list_lock); 52 53 static struct sk_buff *l2cap_build_cmd(struct l2cap_conn *conn, 54 u8 code, u8 ident, u16 dlen, void *data); 55 static void l2cap_send_cmd(struct l2cap_conn *conn, u8 ident, u8 code, u16 len, 56 void *data); 57 static int l2cap_build_conf_req(struct l2cap_chan *chan, void *data, size_t data_size); 58 static void l2cap_send_disconn_req(struct l2cap_chan *chan, int err); 59 60 static void l2cap_tx(struct l2cap_chan *chan, struct l2cap_ctrl *control, 61 struct sk_buff_head *skbs, u8 event); 62 static void l2cap_retrans_timeout(struct work_struct *work); 63 static void l2cap_monitor_timeout(struct work_struct *work); 64 static void l2cap_ack_timeout(struct work_struct *work); 65 66 static inline u8 bdaddr_type(u8 link_type, u8 bdaddr_type) 67 { 68 if (link_type == LE_LINK) { 69 if (bdaddr_type == ADDR_LE_DEV_PUBLIC) 70 return BDADDR_LE_PUBLIC; 71 else 72 return BDADDR_LE_RANDOM; 73 } 74 75 return BDADDR_BREDR; 76 } 77 78 static inline u8 bdaddr_src_type(struct hci_conn *hcon) 79 { 80 return bdaddr_type(hcon->type, hcon->src_type); 81 } 82 83 static inline u8 bdaddr_dst_type(struct hci_conn *hcon) 84 { 85 return bdaddr_type(hcon->type, hcon->dst_type); 86 } 87 88 /* ---- L2CAP channels ---- */ 89 90 static struct l2cap_chan *__l2cap_get_chan_by_dcid(struct l2cap_conn *conn, 91 u16 cid) 92 { 93 struct l2cap_chan *c; 94 95 list_for_each_entry(c, &conn->chan_l, list) { 96 if (c->dcid == cid) 97 return c; 98 } 99 return NULL; 100 } 101 102 static struct l2cap_chan *__l2cap_get_chan_by_scid(struct l2cap_conn *conn, 103 u16 cid) 104 { 105 struct l2cap_chan *c; 106 107 list_for_each_entry(c, &conn->chan_l, list) { 108 if (c->scid == cid) 109 return c; 110 } 111 return NULL; 112 } 113 114 /* Find channel with given SCID. 115 * Returns a reference locked channel. 116 */ 117 static struct l2cap_chan *l2cap_get_chan_by_scid(struct l2cap_conn *conn, 118 u16 cid) 119 { 120 struct l2cap_chan *c; 121 122 mutex_lock(&conn->chan_lock); 123 c = __l2cap_get_chan_by_scid(conn, cid); 124 if (c) { 125 /* Only lock if chan reference is not 0 */ 126 c = l2cap_chan_hold_unless_zero(c); 127 if (c) 128 l2cap_chan_lock(c); 129 } 130 mutex_unlock(&conn->chan_lock); 131 132 return c; 133 } 134 135 /* Find channel with given DCID. 136 * Returns a reference locked channel. 137 */ 138 static struct l2cap_chan *l2cap_get_chan_by_dcid(struct l2cap_conn *conn, 139 u16 cid) 140 { 141 struct l2cap_chan *c; 142 143 mutex_lock(&conn->chan_lock); 144 c = __l2cap_get_chan_by_dcid(conn, cid); 145 if (c) { 146 /* Only lock if chan reference is not 0 */ 147 c = l2cap_chan_hold_unless_zero(c); 148 if (c) 149 l2cap_chan_lock(c); 150 } 151 mutex_unlock(&conn->chan_lock); 152 153 return c; 154 } 155 156 static struct l2cap_chan *__l2cap_get_chan_by_ident(struct l2cap_conn *conn, 157 u8 ident) 158 { 159 struct l2cap_chan *c; 160 161 list_for_each_entry(c, &conn->chan_l, list) { 162 if (c->ident == ident) 163 return c; 164 } 165 return NULL; 166 } 167 168 static struct l2cap_chan *__l2cap_global_chan_by_addr(__le16 psm, bdaddr_t *src, 169 u8 src_type) 170 { 171 struct l2cap_chan *c; 172 173 list_for_each_entry(c, &chan_list, global_l) { 174 if (src_type == BDADDR_BREDR && c->src_type != BDADDR_BREDR) 175 continue; 176 177 if (src_type != BDADDR_BREDR && c->src_type == BDADDR_BREDR) 178 continue; 179 180 if (c->sport == psm && !bacmp(&c->src, src)) 181 return c; 182 } 183 return NULL; 184 } 185 186 int l2cap_add_psm(struct l2cap_chan *chan, bdaddr_t *src, __le16 psm) 187 { 188 int err; 189 190 write_lock(&chan_list_lock); 191 192 if (psm && __l2cap_global_chan_by_addr(psm, src, chan->src_type)) { 193 err = -EADDRINUSE; 194 goto done; 195 } 196 197 if (psm) { 198 chan->psm = psm; 199 chan->sport = psm; 200 err = 0; 201 } else { 202 u16 p, start, end, incr; 203 204 if (chan->src_type == BDADDR_BREDR) { 205 start = L2CAP_PSM_DYN_START; 206 end = L2CAP_PSM_AUTO_END; 207 incr = 2; 208 } else { 209 start = L2CAP_PSM_LE_DYN_START; 210 end = L2CAP_PSM_LE_DYN_END; 211 incr = 1; 212 } 213 214 err = -EINVAL; 215 for (p = start; p <= end; p += incr) 216 if (!__l2cap_global_chan_by_addr(cpu_to_le16(p), src, 217 chan->src_type)) { 218 chan->psm = cpu_to_le16(p); 219 chan->sport = cpu_to_le16(p); 220 err = 0; 221 break; 222 } 223 } 224 225 done: 226 write_unlock(&chan_list_lock); 227 return err; 228 } 229 EXPORT_SYMBOL_GPL(l2cap_add_psm); 230 231 int l2cap_add_scid(struct l2cap_chan *chan, __u16 scid) 232 { 233 write_lock(&chan_list_lock); 234 235 /* Override the defaults (which are for conn-oriented) */ 236 chan->omtu = L2CAP_DEFAULT_MTU; 237 chan->chan_type = L2CAP_CHAN_FIXED; 238 239 chan->scid = scid; 240 241 write_unlock(&chan_list_lock); 242 243 return 0; 244 } 245 246 static u16 l2cap_alloc_cid(struct l2cap_conn *conn) 247 { 248 u16 cid, dyn_end; 249 250 if (conn->hcon->type == LE_LINK) 251 dyn_end = L2CAP_CID_LE_DYN_END; 252 else 253 dyn_end = L2CAP_CID_DYN_END; 254 255 for (cid = L2CAP_CID_DYN_START; cid <= dyn_end; cid++) { 256 if (!__l2cap_get_chan_by_scid(conn, cid)) 257 return cid; 258 } 259 260 return 0; 261 } 262 263 static void l2cap_state_change(struct l2cap_chan *chan, int state) 264 { 265 BT_DBG("chan %p %s -> %s", chan, state_to_string(chan->state), 266 state_to_string(state)); 267 268 chan->state = state; 269 chan->ops->state_change(chan, state, 0); 270 } 271 272 static inline void l2cap_state_change_and_error(struct l2cap_chan *chan, 273 int state, int err) 274 { 275 chan->state = state; 276 chan->ops->state_change(chan, chan->state, err); 277 } 278 279 static inline void l2cap_chan_set_err(struct l2cap_chan *chan, int err) 280 { 281 chan->ops->state_change(chan, chan->state, err); 282 } 283 284 static void __set_retrans_timer(struct l2cap_chan *chan) 285 { 286 if (!delayed_work_pending(&chan->monitor_timer) && 287 chan->retrans_timeout) { 288 l2cap_set_timer(chan, &chan->retrans_timer, 289 msecs_to_jiffies(chan->retrans_timeout)); 290 } 291 } 292 293 static void __set_monitor_timer(struct l2cap_chan *chan) 294 { 295 __clear_retrans_timer(chan); 296 if (chan->monitor_timeout) { 297 l2cap_set_timer(chan, &chan->monitor_timer, 298 msecs_to_jiffies(chan->monitor_timeout)); 299 } 300 } 301 302 static struct sk_buff *l2cap_ertm_seq_in_queue(struct sk_buff_head *head, 303 u16 seq) 304 { 305 struct sk_buff *skb; 306 307 skb_queue_walk(head, skb) { 308 if (bt_cb(skb)->l2cap.txseq == seq) 309 return skb; 310 } 311 312 return NULL; 313 } 314 315 /* ---- L2CAP sequence number lists ---- */ 316 317 /* For ERTM, ordered lists of sequence numbers must be tracked for 318 * SREJ requests that are received and for frames that are to be 319 * retransmitted. These seq_list functions implement a singly-linked 320 * list in an array, where membership in the list can also be checked 321 * in constant time. Items can also be added to the tail of the list 322 * and removed from the head in constant time, without further memory 323 * allocs or frees. 324 */ 325 326 static int l2cap_seq_list_init(struct l2cap_seq_list *seq_list, u16 size) 327 { 328 size_t alloc_size, i; 329 330 /* Allocated size is a power of 2 to map sequence numbers 331 * (which may be up to 14 bits) in to a smaller array that is 332 * sized for the negotiated ERTM transmit windows. 333 */ 334 alloc_size = roundup_pow_of_two(size); 335 336 seq_list->list = kmalloc_array(alloc_size, sizeof(u16), GFP_KERNEL); 337 if (!seq_list->list) 338 return -ENOMEM; 339 340 seq_list->mask = alloc_size - 1; 341 seq_list->head = L2CAP_SEQ_LIST_CLEAR; 342 seq_list->tail = L2CAP_SEQ_LIST_CLEAR; 343 for (i = 0; i < alloc_size; i++) 344 seq_list->list[i] = L2CAP_SEQ_LIST_CLEAR; 345 346 return 0; 347 } 348 349 static inline void l2cap_seq_list_free(struct l2cap_seq_list *seq_list) 350 { 351 kfree(seq_list->list); 352 } 353 354 static inline bool l2cap_seq_list_contains(struct l2cap_seq_list *seq_list, 355 u16 seq) 356 { 357 /* Constant-time check for list membership */ 358 return seq_list->list[seq & seq_list->mask] != L2CAP_SEQ_LIST_CLEAR; 359 } 360 361 static inline u16 l2cap_seq_list_pop(struct l2cap_seq_list *seq_list) 362 { 363 u16 seq = seq_list->head; 364 u16 mask = seq_list->mask; 365 366 seq_list->head = seq_list->list[seq & mask]; 367 seq_list->list[seq & mask] = L2CAP_SEQ_LIST_CLEAR; 368 369 if (seq_list->head == L2CAP_SEQ_LIST_TAIL) { 370 seq_list->head = L2CAP_SEQ_LIST_CLEAR; 371 seq_list->tail = L2CAP_SEQ_LIST_CLEAR; 372 } 373 374 return seq; 375 } 376 377 static void l2cap_seq_list_clear(struct l2cap_seq_list *seq_list) 378 { 379 u16 i; 380 381 if (seq_list->head == L2CAP_SEQ_LIST_CLEAR) 382 return; 383 384 for (i = 0; i <= seq_list->mask; i++) 385 seq_list->list[i] = L2CAP_SEQ_LIST_CLEAR; 386 387 seq_list->head = L2CAP_SEQ_LIST_CLEAR; 388 seq_list->tail = L2CAP_SEQ_LIST_CLEAR; 389 } 390 391 static void l2cap_seq_list_append(struct l2cap_seq_list *seq_list, u16 seq) 392 { 393 u16 mask = seq_list->mask; 394 395 /* All appends happen in constant time */ 396 397 if (seq_list->list[seq & mask] != L2CAP_SEQ_LIST_CLEAR) 398 return; 399 400 if (seq_list->tail == L2CAP_SEQ_LIST_CLEAR) 401 seq_list->head = seq; 402 else 403 seq_list->list[seq_list->tail & mask] = seq; 404 405 seq_list->tail = seq; 406 seq_list->list[seq & mask] = L2CAP_SEQ_LIST_TAIL; 407 } 408 409 static void l2cap_chan_timeout(struct work_struct *work) 410 { 411 struct l2cap_chan *chan = container_of(work, struct l2cap_chan, 412 chan_timer.work); 413 struct l2cap_conn *conn = chan->conn; 414 int reason; 415 416 BT_DBG("chan %p state %s", chan, state_to_string(chan->state)); 417 418 if (!conn) 419 return; 420 421 mutex_lock(&conn->chan_lock); 422 /* __set_chan_timer() calls l2cap_chan_hold(chan) while scheduling 423 * this work. No need to call l2cap_chan_hold(chan) here again. 424 */ 425 l2cap_chan_lock(chan); 426 427 if (chan->state == BT_CONNECTED || chan->state == BT_CONFIG) 428 reason = ECONNREFUSED; 429 else if (chan->state == BT_CONNECT && 430 chan->sec_level != BT_SECURITY_SDP) 431 reason = ECONNREFUSED; 432 else 433 reason = ETIMEDOUT; 434 435 l2cap_chan_close(chan, reason); 436 437 chan->ops->close(chan); 438 439 l2cap_chan_unlock(chan); 440 l2cap_chan_put(chan); 441 442 mutex_unlock(&conn->chan_lock); 443 } 444 445 struct l2cap_chan *l2cap_chan_create(void) 446 { 447 struct l2cap_chan *chan; 448 449 chan = kzalloc(sizeof(*chan), GFP_ATOMIC); 450 if (!chan) 451 return NULL; 452 453 skb_queue_head_init(&chan->tx_q); 454 skb_queue_head_init(&chan->srej_q); 455 mutex_init(&chan->lock); 456 457 /* Set default lock nesting level */ 458 atomic_set(&chan->nesting, L2CAP_NESTING_NORMAL); 459 460 /* Available receive buffer space is initially unknown */ 461 chan->rx_avail = -1; 462 463 write_lock(&chan_list_lock); 464 list_add(&chan->global_l, &chan_list); 465 write_unlock(&chan_list_lock); 466 467 INIT_DELAYED_WORK(&chan->chan_timer, l2cap_chan_timeout); 468 INIT_DELAYED_WORK(&chan->retrans_timer, l2cap_retrans_timeout); 469 INIT_DELAYED_WORK(&chan->monitor_timer, l2cap_monitor_timeout); 470 INIT_DELAYED_WORK(&chan->ack_timer, l2cap_ack_timeout); 471 472 chan->state = BT_OPEN; 473 474 kref_init(&chan->kref); 475 476 /* This flag is cleared in l2cap_chan_ready() */ 477 set_bit(CONF_NOT_COMPLETE, &chan->conf_state); 478 479 BT_DBG("chan %p", chan); 480 481 return chan; 482 } 483 EXPORT_SYMBOL_GPL(l2cap_chan_create); 484 485 static void l2cap_chan_destroy(struct kref *kref) 486 { 487 struct l2cap_chan *chan = container_of(kref, struct l2cap_chan, kref); 488 489 BT_DBG("chan %p", chan); 490 491 write_lock(&chan_list_lock); 492 list_del(&chan->global_l); 493 write_unlock(&chan_list_lock); 494 495 kfree(chan); 496 } 497 498 void l2cap_chan_hold(struct l2cap_chan *c) 499 { 500 BT_DBG("chan %p orig refcnt %u", c, kref_read(&c->kref)); 501 502 kref_get(&c->kref); 503 } 504 505 struct l2cap_chan *l2cap_chan_hold_unless_zero(struct l2cap_chan *c) 506 { 507 BT_DBG("chan %p orig refcnt %u", c, kref_read(&c->kref)); 508 509 if (!kref_get_unless_zero(&c->kref)) 510 return NULL; 511 512 return c; 513 } 514 515 void l2cap_chan_put(struct l2cap_chan *c) 516 { 517 BT_DBG("chan %p orig refcnt %u", c, kref_read(&c->kref)); 518 519 kref_put(&c->kref, l2cap_chan_destroy); 520 } 521 EXPORT_SYMBOL_GPL(l2cap_chan_put); 522 523 void l2cap_chan_set_defaults(struct l2cap_chan *chan) 524 { 525 chan->fcs = L2CAP_FCS_CRC16; 526 chan->max_tx = L2CAP_DEFAULT_MAX_TX; 527 chan->tx_win = L2CAP_DEFAULT_TX_WINDOW; 528 chan->tx_win_max = L2CAP_DEFAULT_TX_WINDOW; 529 chan->remote_max_tx = chan->max_tx; 530 chan->remote_tx_win = chan->tx_win; 531 chan->ack_win = L2CAP_DEFAULT_TX_WINDOW; 532 chan->sec_level = BT_SECURITY_LOW; 533 chan->flush_to = L2CAP_DEFAULT_FLUSH_TO; 534 chan->retrans_timeout = L2CAP_DEFAULT_RETRANS_TO; 535 chan->monitor_timeout = L2CAP_DEFAULT_MONITOR_TO; 536 537 chan->conf_state = 0; 538 set_bit(CONF_NOT_COMPLETE, &chan->conf_state); 539 540 set_bit(FLAG_FORCE_ACTIVE, &chan->flags); 541 } 542 EXPORT_SYMBOL_GPL(l2cap_chan_set_defaults); 543 544 static __u16 l2cap_le_rx_credits(struct l2cap_chan *chan) 545 { 546 size_t sdu_len = chan->sdu ? chan->sdu->len : 0; 547 548 if (chan->mps == 0) 549 return 0; 550 551 /* If we don't know the available space in the receiver buffer, give 552 * enough credits for a full packet. 553 */ 554 if (chan->rx_avail == -1) 555 return (chan->imtu / chan->mps) + 1; 556 557 /* If we know how much space is available in the receive buffer, give 558 * out as many credits as would fill the buffer. 559 */ 560 if (chan->rx_avail <= sdu_len) 561 return 0; 562 563 return DIV_ROUND_UP(chan->rx_avail - sdu_len, chan->mps); 564 } 565 566 static void l2cap_le_flowctl_init(struct l2cap_chan *chan, u16 tx_credits) 567 { 568 chan->sdu = NULL; 569 chan->sdu_last_frag = NULL; 570 chan->sdu_len = 0; 571 chan->tx_credits = tx_credits; 572 /* Derive MPS from connection MTU to stop HCI fragmentation */ 573 chan->mps = min_t(u16, chan->imtu, chan->conn->mtu - L2CAP_HDR_SIZE); 574 chan->rx_credits = l2cap_le_rx_credits(chan); 575 576 skb_queue_head_init(&chan->tx_q); 577 } 578 579 static void l2cap_ecred_init(struct l2cap_chan *chan, u16 tx_credits) 580 { 581 l2cap_le_flowctl_init(chan, tx_credits); 582 583 /* L2CAP implementations shall support a minimum MPS of 64 octets */ 584 if (chan->mps < L2CAP_ECRED_MIN_MPS) { 585 chan->mps = L2CAP_ECRED_MIN_MPS; 586 chan->rx_credits = l2cap_le_rx_credits(chan); 587 } 588 } 589 590 void __l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan) 591 { 592 BT_DBG("conn %p, psm 0x%2.2x, dcid 0x%4.4x", conn, 593 __le16_to_cpu(chan->psm), chan->dcid); 594 595 conn->disc_reason = HCI_ERROR_REMOTE_USER_TERM; 596 597 chan->conn = conn; 598 599 switch (chan->chan_type) { 600 case L2CAP_CHAN_CONN_ORIENTED: 601 /* Alloc CID for connection-oriented socket */ 602 chan->scid = l2cap_alloc_cid(conn); 603 if (conn->hcon->type == ACL_LINK) 604 chan->omtu = L2CAP_DEFAULT_MTU; 605 break; 606 607 case L2CAP_CHAN_CONN_LESS: 608 /* Connectionless socket */ 609 chan->scid = L2CAP_CID_CONN_LESS; 610 chan->dcid = L2CAP_CID_CONN_LESS; 611 chan->omtu = L2CAP_DEFAULT_MTU; 612 break; 613 614 case L2CAP_CHAN_FIXED: 615 /* Caller will set CID and CID specific MTU values */ 616 break; 617 618 default: 619 /* Raw socket can send/recv signalling messages only */ 620 chan->scid = L2CAP_CID_SIGNALING; 621 chan->dcid = L2CAP_CID_SIGNALING; 622 chan->omtu = L2CAP_DEFAULT_MTU; 623 } 624 625 chan->local_id = L2CAP_BESTEFFORT_ID; 626 chan->local_stype = L2CAP_SERV_BESTEFFORT; 627 chan->local_msdu = L2CAP_DEFAULT_MAX_SDU_SIZE; 628 chan->local_sdu_itime = L2CAP_DEFAULT_SDU_ITIME; 629 chan->local_acc_lat = L2CAP_DEFAULT_ACC_LAT; 630 chan->local_flush_to = L2CAP_EFS_DEFAULT_FLUSH_TO; 631 632 l2cap_chan_hold(chan); 633 634 /* Only keep a reference for fixed channels if they requested it */ 635 if (chan->chan_type != L2CAP_CHAN_FIXED || 636 test_bit(FLAG_HOLD_HCI_CONN, &chan->flags)) 637 hci_conn_hold(conn->hcon); 638 639 list_add(&chan->list, &conn->chan_l); 640 } 641 642 void l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan) 643 { 644 mutex_lock(&conn->chan_lock); 645 __l2cap_chan_add(conn, chan); 646 mutex_unlock(&conn->chan_lock); 647 } 648 649 void l2cap_chan_del(struct l2cap_chan *chan, int err) 650 { 651 struct l2cap_conn *conn = chan->conn; 652 653 __clear_chan_timer(chan); 654 655 BT_DBG("chan %p, conn %p, err %d, state %s", chan, conn, err, 656 state_to_string(chan->state)); 657 658 chan->ops->teardown(chan, err); 659 660 if (conn) { 661 /* Delete from channel list */ 662 list_del(&chan->list); 663 664 l2cap_chan_put(chan); 665 666 chan->conn = NULL; 667 668 /* Reference was only held for non-fixed channels or 669 * fixed channels that explicitly requested it using the 670 * FLAG_HOLD_HCI_CONN flag. 671 */ 672 if (chan->chan_type != L2CAP_CHAN_FIXED || 673 test_bit(FLAG_HOLD_HCI_CONN, &chan->flags)) 674 hci_conn_drop(conn->hcon); 675 } 676 677 if (test_bit(CONF_NOT_COMPLETE, &chan->conf_state)) 678 return; 679 680 switch (chan->mode) { 681 case L2CAP_MODE_BASIC: 682 break; 683 684 case L2CAP_MODE_LE_FLOWCTL: 685 case L2CAP_MODE_EXT_FLOWCTL: 686 skb_queue_purge(&chan->tx_q); 687 break; 688 689 case L2CAP_MODE_ERTM: 690 __clear_retrans_timer(chan); 691 __clear_monitor_timer(chan); 692 __clear_ack_timer(chan); 693 694 skb_queue_purge(&chan->srej_q); 695 696 l2cap_seq_list_free(&chan->srej_list); 697 l2cap_seq_list_free(&chan->retrans_list); 698 fallthrough; 699 700 case L2CAP_MODE_STREAMING: 701 skb_queue_purge(&chan->tx_q); 702 break; 703 } 704 } 705 EXPORT_SYMBOL_GPL(l2cap_chan_del); 706 707 static void __l2cap_chan_list_id(struct l2cap_conn *conn, u16 id, 708 l2cap_chan_func_t func, void *data) 709 { 710 struct l2cap_chan *chan, *l; 711 712 list_for_each_entry_safe(chan, l, &conn->chan_l, list) { 713 if (chan->ident == id) 714 func(chan, data); 715 } 716 } 717 718 static void __l2cap_chan_list(struct l2cap_conn *conn, l2cap_chan_func_t func, 719 void *data) 720 { 721 struct l2cap_chan *chan; 722 723 list_for_each_entry(chan, &conn->chan_l, list) { 724 func(chan, data); 725 } 726 } 727 728 void l2cap_chan_list(struct l2cap_conn *conn, l2cap_chan_func_t func, 729 void *data) 730 { 731 if (!conn) 732 return; 733 734 mutex_lock(&conn->chan_lock); 735 __l2cap_chan_list(conn, func, data); 736 mutex_unlock(&conn->chan_lock); 737 } 738 739 EXPORT_SYMBOL_GPL(l2cap_chan_list); 740 741 static void l2cap_conn_update_id_addr(struct work_struct *work) 742 { 743 struct l2cap_conn *conn = container_of(work, struct l2cap_conn, 744 id_addr_timer.work); 745 struct hci_conn *hcon = conn->hcon; 746 struct l2cap_chan *chan; 747 748 mutex_lock(&conn->chan_lock); 749 750 list_for_each_entry(chan, &conn->chan_l, list) { 751 l2cap_chan_lock(chan); 752 bacpy(&chan->dst, &hcon->dst); 753 chan->dst_type = bdaddr_dst_type(hcon); 754 l2cap_chan_unlock(chan); 755 } 756 757 mutex_unlock(&conn->chan_lock); 758 } 759 760 static void l2cap_chan_le_connect_reject(struct l2cap_chan *chan) 761 { 762 struct l2cap_conn *conn = chan->conn; 763 struct l2cap_le_conn_rsp rsp; 764 u16 result; 765 766 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) 767 result = L2CAP_CR_LE_AUTHORIZATION; 768 else 769 result = L2CAP_CR_LE_BAD_PSM; 770 771 l2cap_state_change(chan, BT_DISCONN); 772 773 rsp.dcid = cpu_to_le16(chan->scid); 774 rsp.mtu = cpu_to_le16(chan->imtu); 775 rsp.mps = cpu_to_le16(chan->mps); 776 rsp.credits = cpu_to_le16(chan->rx_credits); 777 rsp.result = cpu_to_le16(result); 778 779 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_RSP, sizeof(rsp), 780 &rsp); 781 } 782 783 static void l2cap_chan_ecred_connect_reject(struct l2cap_chan *chan) 784 { 785 l2cap_state_change(chan, BT_DISCONN); 786 787 __l2cap_ecred_conn_rsp_defer(chan); 788 } 789 790 static void l2cap_chan_connect_reject(struct l2cap_chan *chan) 791 { 792 struct l2cap_conn *conn = chan->conn; 793 struct l2cap_conn_rsp rsp; 794 u16 result; 795 796 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) 797 result = L2CAP_CR_SEC_BLOCK; 798 else 799 result = L2CAP_CR_BAD_PSM; 800 801 l2cap_state_change(chan, BT_DISCONN); 802 803 rsp.scid = cpu_to_le16(chan->dcid); 804 rsp.dcid = cpu_to_le16(chan->scid); 805 rsp.result = cpu_to_le16(result); 806 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO); 807 808 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP, sizeof(rsp), &rsp); 809 } 810 811 void l2cap_chan_close(struct l2cap_chan *chan, int reason) 812 { 813 struct l2cap_conn *conn = chan->conn; 814 815 BT_DBG("chan %p state %s", chan, state_to_string(chan->state)); 816 817 switch (chan->state) { 818 case BT_LISTEN: 819 chan->ops->teardown(chan, 0); 820 break; 821 822 case BT_CONNECTED: 823 case BT_CONFIG: 824 if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED) { 825 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan)); 826 l2cap_send_disconn_req(chan, reason); 827 } else 828 l2cap_chan_del(chan, reason); 829 break; 830 831 case BT_CONNECT2: 832 if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED) { 833 if (conn->hcon->type == ACL_LINK) 834 l2cap_chan_connect_reject(chan); 835 else if (conn->hcon->type == LE_LINK) { 836 switch (chan->mode) { 837 case L2CAP_MODE_LE_FLOWCTL: 838 l2cap_chan_le_connect_reject(chan); 839 break; 840 case L2CAP_MODE_EXT_FLOWCTL: 841 l2cap_chan_ecred_connect_reject(chan); 842 return; 843 } 844 } 845 } 846 847 l2cap_chan_del(chan, reason); 848 break; 849 850 case BT_CONNECT: 851 case BT_DISCONN: 852 l2cap_chan_del(chan, reason); 853 break; 854 855 default: 856 chan->ops->teardown(chan, 0); 857 break; 858 } 859 } 860 EXPORT_SYMBOL(l2cap_chan_close); 861 862 static inline u8 l2cap_get_auth_type(struct l2cap_chan *chan) 863 { 864 switch (chan->chan_type) { 865 case L2CAP_CHAN_RAW: 866 switch (chan->sec_level) { 867 case BT_SECURITY_HIGH: 868 case BT_SECURITY_FIPS: 869 return HCI_AT_DEDICATED_BONDING_MITM; 870 case BT_SECURITY_MEDIUM: 871 return HCI_AT_DEDICATED_BONDING; 872 default: 873 return HCI_AT_NO_BONDING; 874 } 875 break; 876 case L2CAP_CHAN_CONN_LESS: 877 if (chan->psm == cpu_to_le16(L2CAP_PSM_3DSP)) { 878 if (chan->sec_level == BT_SECURITY_LOW) 879 chan->sec_level = BT_SECURITY_SDP; 880 } 881 if (chan->sec_level == BT_SECURITY_HIGH || 882 chan->sec_level == BT_SECURITY_FIPS) 883 return HCI_AT_NO_BONDING_MITM; 884 else 885 return HCI_AT_NO_BONDING; 886 break; 887 case L2CAP_CHAN_CONN_ORIENTED: 888 if (chan->psm == cpu_to_le16(L2CAP_PSM_SDP)) { 889 if (chan->sec_level == BT_SECURITY_LOW) 890 chan->sec_level = BT_SECURITY_SDP; 891 892 if (chan->sec_level == BT_SECURITY_HIGH || 893 chan->sec_level == BT_SECURITY_FIPS) 894 return HCI_AT_NO_BONDING_MITM; 895 else 896 return HCI_AT_NO_BONDING; 897 } 898 fallthrough; 899 900 default: 901 switch (chan->sec_level) { 902 case BT_SECURITY_HIGH: 903 case BT_SECURITY_FIPS: 904 return HCI_AT_GENERAL_BONDING_MITM; 905 case BT_SECURITY_MEDIUM: 906 return HCI_AT_GENERAL_BONDING; 907 default: 908 return HCI_AT_NO_BONDING; 909 } 910 break; 911 } 912 } 913 914 /* Service level security */ 915 int l2cap_chan_check_security(struct l2cap_chan *chan, bool initiator) 916 { 917 struct l2cap_conn *conn = chan->conn; 918 __u8 auth_type; 919 920 if (conn->hcon->type == LE_LINK) 921 return smp_conn_security(conn->hcon, chan->sec_level); 922 923 auth_type = l2cap_get_auth_type(chan); 924 925 return hci_conn_security(conn->hcon, chan->sec_level, auth_type, 926 initiator); 927 } 928 929 static u8 l2cap_get_ident(struct l2cap_conn *conn) 930 { 931 u8 id; 932 933 /* Get next available identificator. 934 * 1 - 128 are used by kernel. 935 * 129 - 199 are reserved. 936 * 200 - 254 are used by utilities like l2ping, etc. 937 */ 938 939 mutex_lock(&conn->ident_lock); 940 941 if (++conn->tx_ident > 128) 942 conn->tx_ident = 1; 943 944 id = conn->tx_ident; 945 946 mutex_unlock(&conn->ident_lock); 947 948 return id; 949 } 950 951 static void l2cap_send_cmd(struct l2cap_conn *conn, u8 ident, u8 code, u16 len, 952 void *data) 953 { 954 struct sk_buff *skb = l2cap_build_cmd(conn, code, ident, len, data); 955 u8 flags; 956 957 BT_DBG("code 0x%2.2x", code); 958 959 if (!skb) 960 return; 961 962 /* Use NO_FLUSH if supported or we have an LE link (which does 963 * not support auto-flushing packets) */ 964 if (lmp_no_flush_capable(conn->hcon->hdev) || 965 conn->hcon->type == LE_LINK) 966 flags = ACL_START_NO_FLUSH; 967 else 968 flags = ACL_START; 969 970 bt_cb(skb)->force_active = BT_POWER_FORCE_ACTIVE_ON; 971 skb->priority = HCI_PRIO_MAX; 972 973 hci_send_acl(conn->hchan, skb, flags); 974 } 975 976 static void l2cap_do_send(struct l2cap_chan *chan, struct sk_buff *skb) 977 { 978 struct hci_conn *hcon = chan->conn->hcon; 979 u16 flags; 980 981 BT_DBG("chan %p, skb %p len %d priority %u", chan, skb, skb->len, 982 skb->priority); 983 984 /* Use NO_FLUSH for LE links (where this is the only option) or 985 * if the BR/EDR link supports it and flushing has not been 986 * explicitly requested (through FLAG_FLUSHABLE). 987 */ 988 if (hcon->type == LE_LINK || 989 (!test_bit(FLAG_FLUSHABLE, &chan->flags) && 990 lmp_no_flush_capable(hcon->hdev))) 991 flags = ACL_START_NO_FLUSH; 992 else 993 flags = ACL_START; 994 995 bt_cb(skb)->force_active = test_bit(FLAG_FORCE_ACTIVE, &chan->flags); 996 hci_send_acl(chan->conn->hchan, skb, flags); 997 } 998 999 static void __unpack_enhanced_control(u16 enh, struct l2cap_ctrl *control) 1000 { 1001 control->reqseq = (enh & L2CAP_CTRL_REQSEQ) >> L2CAP_CTRL_REQSEQ_SHIFT; 1002 control->final = (enh & L2CAP_CTRL_FINAL) >> L2CAP_CTRL_FINAL_SHIFT; 1003 1004 if (enh & L2CAP_CTRL_FRAME_TYPE) { 1005 /* S-Frame */ 1006 control->sframe = 1; 1007 control->poll = (enh & L2CAP_CTRL_POLL) >> L2CAP_CTRL_POLL_SHIFT; 1008 control->super = (enh & L2CAP_CTRL_SUPERVISE) >> L2CAP_CTRL_SUPER_SHIFT; 1009 1010 control->sar = 0; 1011 control->txseq = 0; 1012 } else { 1013 /* I-Frame */ 1014 control->sframe = 0; 1015 control->sar = (enh & L2CAP_CTRL_SAR) >> L2CAP_CTRL_SAR_SHIFT; 1016 control->txseq = (enh & L2CAP_CTRL_TXSEQ) >> L2CAP_CTRL_TXSEQ_SHIFT; 1017 1018 control->poll = 0; 1019 control->super = 0; 1020 } 1021 } 1022 1023 static void __unpack_extended_control(u32 ext, struct l2cap_ctrl *control) 1024 { 1025 control->reqseq = (ext & L2CAP_EXT_CTRL_REQSEQ) >> L2CAP_EXT_CTRL_REQSEQ_SHIFT; 1026 control->final = (ext & L2CAP_EXT_CTRL_FINAL) >> L2CAP_EXT_CTRL_FINAL_SHIFT; 1027 1028 if (ext & L2CAP_EXT_CTRL_FRAME_TYPE) { 1029 /* S-Frame */ 1030 control->sframe = 1; 1031 control->poll = (ext & L2CAP_EXT_CTRL_POLL) >> L2CAP_EXT_CTRL_POLL_SHIFT; 1032 control->super = (ext & L2CAP_EXT_CTRL_SUPERVISE) >> L2CAP_EXT_CTRL_SUPER_SHIFT; 1033 1034 control->sar = 0; 1035 control->txseq = 0; 1036 } else { 1037 /* I-Frame */ 1038 control->sframe = 0; 1039 control->sar = (ext & L2CAP_EXT_CTRL_SAR) >> L2CAP_EXT_CTRL_SAR_SHIFT; 1040 control->txseq = (ext & L2CAP_EXT_CTRL_TXSEQ) >> L2CAP_EXT_CTRL_TXSEQ_SHIFT; 1041 1042 control->poll = 0; 1043 control->super = 0; 1044 } 1045 } 1046 1047 static inline void __unpack_control(struct l2cap_chan *chan, 1048 struct sk_buff *skb) 1049 { 1050 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) { 1051 __unpack_extended_control(get_unaligned_le32(skb->data), 1052 &bt_cb(skb)->l2cap); 1053 skb_pull(skb, L2CAP_EXT_CTRL_SIZE); 1054 } else { 1055 __unpack_enhanced_control(get_unaligned_le16(skb->data), 1056 &bt_cb(skb)->l2cap); 1057 skb_pull(skb, L2CAP_ENH_CTRL_SIZE); 1058 } 1059 } 1060 1061 static u32 __pack_extended_control(struct l2cap_ctrl *control) 1062 { 1063 u32 packed; 1064 1065 packed = control->reqseq << L2CAP_EXT_CTRL_REQSEQ_SHIFT; 1066 packed |= control->final << L2CAP_EXT_CTRL_FINAL_SHIFT; 1067 1068 if (control->sframe) { 1069 packed |= control->poll << L2CAP_EXT_CTRL_POLL_SHIFT; 1070 packed |= control->super << L2CAP_EXT_CTRL_SUPER_SHIFT; 1071 packed |= L2CAP_EXT_CTRL_FRAME_TYPE; 1072 } else { 1073 packed |= control->sar << L2CAP_EXT_CTRL_SAR_SHIFT; 1074 packed |= control->txseq << L2CAP_EXT_CTRL_TXSEQ_SHIFT; 1075 } 1076 1077 return packed; 1078 } 1079 1080 static u16 __pack_enhanced_control(struct l2cap_ctrl *control) 1081 { 1082 u16 packed; 1083 1084 packed = control->reqseq << L2CAP_CTRL_REQSEQ_SHIFT; 1085 packed |= control->final << L2CAP_CTRL_FINAL_SHIFT; 1086 1087 if (control->sframe) { 1088 packed |= control->poll << L2CAP_CTRL_POLL_SHIFT; 1089 packed |= control->super << L2CAP_CTRL_SUPER_SHIFT; 1090 packed |= L2CAP_CTRL_FRAME_TYPE; 1091 } else { 1092 packed |= control->sar << L2CAP_CTRL_SAR_SHIFT; 1093 packed |= control->txseq << L2CAP_CTRL_TXSEQ_SHIFT; 1094 } 1095 1096 return packed; 1097 } 1098 1099 static inline void __pack_control(struct l2cap_chan *chan, 1100 struct l2cap_ctrl *control, 1101 struct sk_buff *skb) 1102 { 1103 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) { 1104 put_unaligned_le32(__pack_extended_control(control), 1105 skb->data + L2CAP_HDR_SIZE); 1106 } else { 1107 put_unaligned_le16(__pack_enhanced_control(control), 1108 skb->data + L2CAP_HDR_SIZE); 1109 } 1110 } 1111 1112 static inline unsigned int __ertm_hdr_size(struct l2cap_chan *chan) 1113 { 1114 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) 1115 return L2CAP_EXT_HDR_SIZE; 1116 else 1117 return L2CAP_ENH_HDR_SIZE; 1118 } 1119 1120 static struct sk_buff *l2cap_create_sframe_pdu(struct l2cap_chan *chan, 1121 u32 control) 1122 { 1123 struct sk_buff *skb; 1124 struct l2cap_hdr *lh; 1125 int hlen = __ertm_hdr_size(chan); 1126 1127 if (chan->fcs == L2CAP_FCS_CRC16) 1128 hlen += L2CAP_FCS_SIZE; 1129 1130 skb = bt_skb_alloc(hlen, GFP_KERNEL); 1131 1132 if (!skb) 1133 return ERR_PTR(-ENOMEM); 1134 1135 lh = skb_put(skb, L2CAP_HDR_SIZE); 1136 lh->len = cpu_to_le16(hlen - L2CAP_HDR_SIZE); 1137 lh->cid = cpu_to_le16(chan->dcid); 1138 1139 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) 1140 put_unaligned_le32(control, skb_put(skb, L2CAP_EXT_CTRL_SIZE)); 1141 else 1142 put_unaligned_le16(control, skb_put(skb, L2CAP_ENH_CTRL_SIZE)); 1143 1144 if (chan->fcs == L2CAP_FCS_CRC16) { 1145 u16 fcs = crc16(0, (u8 *)skb->data, skb->len); 1146 put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE)); 1147 } 1148 1149 skb->priority = HCI_PRIO_MAX; 1150 return skb; 1151 } 1152 1153 static void l2cap_send_sframe(struct l2cap_chan *chan, 1154 struct l2cap_ctrl *control) 1155 { 1156 struct sk_buff *skb; 1157 u32 control_field; 1158 1159 BT_DBG("chan %p, control %p", chan, control); 1160 1161 if (!control->sframe) 1162 return; 1163 1164 if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state) && 1165 !control->poll) 1166 control->final = 1; 1167 1168 if (control->super == L2CAP_SUPER_RR) 1169 clear_bit(CONN_RNR_SENT, &chan->conn_state); 1170 else if (control->super == L2CAP_SUPER_RNR) 1171 set_bit(CONN_RNR_SENT, &chan->conn_state); 1172 1173 if (control->super != L2CAP_SUPER_SREJ) { 1174 chan->last_acked_seq = control->reqseq; 1175 __clear_ack_timer(chan); 1176 } 1177 1178 BT_DBG("reqseq %d, final %d, poll %d, super %d", control->reqseq, 1179 control->final, control->poll, control->super); 1180 1181 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) 1182 control_field = __pack_extended_control(control); 1183 else 1184 control_field = __pack_enhanced_control(control); 1185 1186 skb = l2cap_create_sframe_pdu(chan, control_field); 1187 if (!IS_ERR(skb)) 1188 l2cap_do_send(chan, skb); 1189 } 1190 1191 static void l2cap_send_rr_or_rnr(struct l2cap_chan *chan, bool poll) 1192 { 1193 struct l2cap_ctrl control; 1194 1195 BT_DBG("chan %p, poll %d", chan, poll); 1196 1197 memset(&control, 0, sizeof(control)); 1198 control.sframe = 1; 1199 control.poll = poll; 1200 1201 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) 1202 control.super = L2CAP_SUPER_RNR; 1203 else 1204 control.super = L2CAP_SUPER_RR; 1205 1206 control.reqseq = chan->buffer_seq; 1207 l2cap_send_sframe(chan, &control); 1208 } 1209 1210 static inline int __l2cap_no_conn_pending(struct l2cap_chan *chan) 1211 { 1212 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) 1213 return true; 1214 1215 return !test_bit(CONF_CONNECT_PEND, &chan->conf_state); 1216 } 1217 1218 void l2cap_send_conn_req(struct l2cap_chan *chan) 1219 { 1220 struct l2cap_conn *conn = chan->conn; 1221 struct l2cap_conn_req req; 1222 1223 req.scid = cpu_to_le16(chan->scid); 1224 req.psm = chan->psm; 1225 1226 chan->ident = l2cap_get_ident(conn); 1227 1228 set_bit(CONF_CONNECT_PEND, &chan->conf_state); 1229 1230 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_REQ, sizeof(req), &req); 1231 } 1232 1233 static void l2cap_chan_ready(struct l2cap_chan *chan) 1234 { 1235 /* The channel may have already been flagged as connected in 1236 * case of receiving data before the L2CAP info req/rsp 1237 * procedure is complete. 1238 */ 1239 if (chan->state == BT_CONNECTED) 1240 return; 1241 1242 /* This clears all conf flags, including CONF_NOT_COMPLETE */ 1243 chan->conf_state = 0; 1244 __clear_chan_timer(chan); 1245 1246 switch (chan->mode) { 1247 case L2CAP_MODE_LE_FLOWCTL: 1248 case L2CAP_MODE_EXT_FLOWCTL: 1249 if (!chan->tx_credits) 1250 chan->ops->suspend(chan); 1251 break; 1252 } 1253 1254 chan->state = BT_CONNECTED; 1255 1256 chan->ops->ready(chan); 1257 } 1258 1259 static void l2cap_le_connect(struct l2cap_chan *chan) 1260 { 1261 struct l2cap_conn *conn = chan->conn; 1262 struct l2cap_le_conn_req req; 1263 1264 if (test_and_set_bit(FLAG_LE_CONN_REQ_SENT, &chan->flags)) 1265 return; 1266 1267 if (!chan->imtu) 1268 chan->imtu = chan->conn->mtu; 1269 1270 l2cap_le_flowctl_init(chan, 0); 1271 1272 memset(&req, 0, sizeof(req)); 1273 req.psm = chan->psm; 1274 req.scid = cpu_to_le16(chan->scid); 1275 req.mtu = cpu_to_le16(chan->imtu); 1276 req.mps = cpu_to_le16(chan->mps); 1277 req.credits = cpu_to_le16(chan->rx_credits); 1278 1279 chan->ident = l2cap_get_ident(conn); 1280 1281 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_REQ, 1282 sizeof(req), &req); 1283 } 1284 1285 struct l2cap_ecred_conn_data { 1286 struct { 1287 struct l2cap_ecred_conn_req req; 1288 __le16 scid[5]; 1289 } __packed pdu; 1290 struct l2cap_chan *chan; 1291 struct pid *pid; 1292 int count; 1293 }; 1294 1295 static void l2cap_ecred_defer_connect(struct l2cap_chan *chan, void *data) 1296 { 1297 struct l2cap_ecred_conn_data *conn = data; 1298 struct pid *pid; 1299 1300 if (chan == conn->chan) 1301 return; 1302 1303 if (!test_and_clear_bit(FLAG_DEFER_SETUP, &chan->flags)) 1304 return; 1305 1306 pid = chan->ops->get_peer_pid(chan); 1307 1308 /* Only add deferred channels with the same PID/PSM */ 1309 if (conn->pid != pid || chan->psm != conn->chan->psm || chan->ident || 1310 chan->mode != L2CAP_MODE_EXT_FLOWCTL || chan->state != BT_CONNECT) 1311 return; 1312 1313 if (test_and_set_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags)) 1314 return; 1315 1316 l2cap_ecred_init(chan, 0); 1317 1318 /* Set the same ident so we can match on the rsp */ 1319 chan->ident = conn->chan->ident; 1320 1321 /* Include all channels deferred */ 1322 conn->pdu.scid[conn->count] = cpu_to_le16(chan->scid); 1323 1324 conn->count++; 1325 } 1326 1327 static void l2cap_ecred_connect(struct l2cap_chan *chan) 1328 { 1329 struct l2cap_conn *conn = chan->conn; 1330 struct l2cap_ecred_conn_data data; 1331 1332 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) 1333 return; 1334 1335 if (test_and_set_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags)) 1336 return; 1337 1338 l2cap_ecred_init(chan, 0); 1339 1340 memset(&data, 0, sizeof(data)); 1341 data.pdu.req.psm = chan->psm; 1342 data.pdu.req.mtu = cpu_to_le16(chan->imtu); 1343 data.pdu.req.mps = cpu_to_le16(chan->mps); 1344 data.pdu.req.credits = cpu_to_le16(chan->rx_credits); 1345 data.pdu.scid[0] = cpu_to_le16(chan->scid); 1346 1347 chan->ident = l2cap_get_ident(conn); 1348 1349 data.count = 1; 1350 data.chan = chan; 1351 data.pid = chan->ops->get_peer_pid(chan); 1352 1353 __l2cap_chan_list(conn, l2cap_ecred_defer_connect, &data); 1354 1355 l2cap_send_cmd(conn, chan->ident, L2CAP_ECRED_CONN_REQ, 1356 sizeof(data.pdu.req) + data.count * sizeof(__le16), 1357 &data.pdu); 1358 } 1359 1360 static void l2cap_le_start(struct l2cap_chan *chan) 1361 { 1362 struct l2cap_conn *conn = chan->conn; 1363 1364 if (!smp_conn_security(conn->hcon, chan->sec_level)) 1365 return; 1366 1367 if (!chan->psm) { 1368 l2cap_chan_ready(chan); 1369 return; 1370 } 1371 1372 if (chan->state == BT_CONNECT) { 1373 if (chan->mode == L2CAP_MODE_EXT_FLOWCTL) 1374 l2cap_ecred_connect(chan); 1375 else 1376 l2cap_le_connect(chan); 1377 } 1378 } 1379 1380 static void l2cap_start_connection(struct l2cap_chan *chan) 1381 { 1382 if (chan->conn->hcon->type == LE_LINK) { 1383 l2cap_le_start(chan); 1384 } else { 1385 l2cap_send_conn_req(chan); 1386 } 1387 } 1388 1389 static void l2cap_request_info(struct l2cap_conn *conn) 1390 { 1391 struct l2cap_info_req req; 1392 1393 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT) 1394 return; 1395 1396 req.type = cpu_to_le16(L2CAP_IT_FEAT_MASK); 1397 1398 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_SENT; 1399 conn->info_ident = l2cap_get_ident(conn); 1400 1401 schedule_delayed_work(&conn->info_timer, L2CAP_INFO_TIMEOUT); 1402 1403 l2cap_send_cmd(conn, conn->info_ident, L2CAP_INFO_REQ, 1404 sizeof(req), &req); 1405 } 1406 1407 static bool l2cap_check_enc_key_size(struct hci_conn *hcon) 1408 { 1409 /* The minimum encryption key size needs to be enforced by the 1410 * host stack before establishing any L2CAP connections. The 1411 * specification in theory allows a minimum of 1, but to align 1412 * BR/EDR and LE transports, a minimum of 7 is chosen. 1413 * 1414 * This check might also be called for unencrypted connections 1415 * that have no key size requirements. Ensure that the link is 1416 * actually encrypted before enforcing a key size. 1417 */ 1418 int min_key_size = hcon->hdev->min_enc_key_size; 1419 1420 /* On FIPS security level, key size must be 16 bytes */ 1421 if (hcon->sec_level == BT_SECURITY_FIPS) 1422 min_key_size = 16; 1423 1424 return (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags) || 1425 hcon->enc_key_size >= min_key_size); 1426 } 1427 1428 static void l2cap_do_start(struct l2cap_chan *chan) 1429 { 1430 struct l2cap_conn *conn = chan->conn; 1431 1432 if (conn->hcon->type == LE_LINK) { 1433 l2cap_le_start(chan); 1434 return; 1435 } 1436 1437 if (!(conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT)) { 1438 l2cap_request_info(conn); 1439 return; 1440 } 1441 1442 if (!(conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE)) 1443 return; 1444 1445 if (!l2cap_chan_check_security(chan, true) || 1446 !__l2cap_no_conn_pending(chan)) 1447 return; 1448 1449 if (l2cap_check_enc_key_size(conn->hcon)) 1450 l2cap_start_connection(chan); 1451 else 1452 __set_chan_timer(chan, L2CAP_DISC_TIMEOUT); 1453 } 1454 1455 static inline int l2cap_mode_supported(__u8 mode, __u32 feat_mask) 1456 { 1457 u32 local_feat_mask = l2cap_feat_mask; 1458 if (!disable_ertm) 1459 local_feat_mask |= L2CAP_FEAT_ERTM | L2CAP_FEAT_STREAMING; 1460 1461 switch (mode) { 1462 case L2CAP_MODE_ERTM: 1463 return L2CAP_FEAT_ERTM & feat_mask & local_feat_mask; 1464 case L2CAP_MODE_STREAMING: 1465 return L2CAP_FEAT_STREAMING & feat_mask & local_feat_mask; 1466 default: 1467 return 0x00; 1468 } 1469 } 1470 1471 static void l2cap_send_disconn_req(struct l2cap_chan *chan, int err) 1472 { 1473 struct l2cap_conn *conn = chan->conn; 1474 struct l2cap_disconn_req req; 1475 1476 if (!conn) 1477 return; 1478 1479 if (chan->mode == L2CAP_MODE_ERTM && chan->state == BT_CONNECTED) { 1480 __clear_retrans_timer(chan); 1481 __clear_monitor_timer(chan); 1482 __clear_ack_timer(chan); 1483 } 1484 1485 req.dcid = cpu_to_le16(chan->dcid); 1486 req.scid = cpu_to_le16(chan->scid); 1487 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_DISCONN_REQ, 1488 sizeof(req), &req); 1489 1490 l2cap_state_change_and_error(chan, BT_DISCONN, err); 1491 } 1492 1493 /* ---- L2CAP connections ---- */ 1494 static void l2cap_conn_start(struct l2cap_conn *conn) 1495 { 1496 struct l2cap_chan *chan, *tmp; 1497 1498 BT_DBG("conn %p", conn); 1499 1500 mutex_lock(&conn->chan_lock); 1501 1502 list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) { 1503 l2cap_chan_lock(chan); 1504 1505 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) { 1506 l2cap_chan_ready(chan); 1507 l2cap_chan_unlock(chan); 1508 continue; 1509 } 1510 1511 if (chan->state == BT_CONNECT) { 1512 if (!l2cap_chan_check_security(chan, true) || 1513 !__l2cap_no_conn_pending(chan)) { 1514 l2cap_chan_unlock(chan); 1515 continue; 1516 } 1517 1518 if (!l2cap_mode_supported(chan->mode, conn->feat_mask) 1519 && test_bit(CONF_STATE2_DEVICE, 1520 &chan->conf_state)) { 1521 l2cap_chan_close(chan, ECONNRESET); 1522 l2cap_chan_unlock(chan); 1523 continue; 1524 } 1525 1526 if (l2cap_check_enc_key_size(conn->hcon)) 1527 l2cap_start_connection(chan); 1528 else 1529 l2cap_chan_close(chan, ECONNREFUSED); 1530 1531 } else if (chan->state == BT_CONNECT2) { 1532 struct l2cap_conn_rsp rsp; 1533 char buf[128]; 1534 rsp.scid = cpu_to_le16(chan->dcid); 1535 rsp.dcid = cpu_to_le16(chan->scid); 1536 1537 if (l2cap_chan_check_security(chan, false)) { 1538 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) { 1539 rsp.result = cpu_to_le16(L2CAP_CR_PEND); 1540 rsp.status = cpu_to_le16(L2CAP_CS_AUTHOR_PEND); 1541 chan->ops->defer(chan); 1542 1543 } else { 1544 l2cap_state_change(chan, BT_CONFIG); 1545 rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS); 1546 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO); 1547 } 1548 } else { 1549 rsp.result = cpu_to_le16(L2CAP_CR_PEND); 1550 rsp.status = cpu_to_le16(L2CAP_CS_AUTHEN_PEND); 1551 } 1552 1553 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP, 1554 sizeof(rsp), &rsp); 1555 1556 if (test_bit(CONF_REQ_SENT, &chan->conf_state) || 1557 rsp.result != L2CAP_CR_SUCCESS) { 1558 l2cap_chan_unlock(chan); 1559 continue; 1560 } 1561 1562 set_bit(CONF_REQ_SENT, &chan->conf_state); 1563 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ, 1564 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf); 1565 chan->num_conf_req++; 1566 } 1567 1568 l2cap_chan_unlock(chan); 1569 } 1570 1571 mutex_unlock(&conn->chan_lock); 1572 } 1573 1574 static void l2cap_le_conn_ready(struct l2cap_conn *conn) 1575 { 1576 struct hci_conn *hcon = conn->hcon; 1577 struct hci_dev *hdev = hcon->hdev; 1578 1579 BT_DBG("%s conn %p", hdev->name, conn); 1580 1581 /* For outgoing pairing which doesn't necessarily have an 1582 * associated socket (e.g. mgmt_pair_device). 1583 */ 1584 if (hcon->out) 1585 smp_conn_security(hcon, hcon->pending_sec_level); 1586 1587 /* For LE peripheral connections, make sure the connection interval 1588 * is in the range of the minimum and maximum interval that has 1589 * been configured for this connection. If not, then trigger 1590 * the connection update procedure. 1591 */ 1592 if (hcon->role == HCI_ROLE_SLAVE && 1593 (hcon->le_conn_interval < hcon->le_conn_min_interval || 1594 hcon->le_conn_interval > hcon->le_conn_max_interval)) { 1595 struct l2cap_conn_param_update_req req; 1596 1597 req.min = cpu_to_le16(hcon->le_conn_min_interval); 1598 req.max = cpu_to_le16(hcon->le_conn_max_interval); 1599 req.latency = cpu_to_le16(hcon->le_conn_latency); 1600 req.to_multiplier = cpu_to_le16(hcon->le_supv_timeout); 1601 1602 l2cap_send_cmd(conn, l2cap_get_ident(conn), 1603 L2CAP_CONN_PARAM_UPDATE_REQ, sizeof(req), &req); 1604 } 1605 } 1606 1607 static void l2cap_conn_ready(struct l2cap_conn *conn) 1608 { 1609 struct l2cap_chan *chan; 1610 struct hci_conn *hcon = conn->hcon; 1611 1612 BT_DBG("conn %p", conn); 1613 1614 if (hcon->type == ACL_LINK) 1615 l2cap_request_info(conn); 1616 1617 mutex_lock(&conn->chan_lock); 1618 1619 list_for_each_entry(chan, &conn->chan_l, list) { 1620 1621 l2cap_chan_lock(chan); 1622 1623 if (hcon->type == LE_LINK) { 1624 l2cap_le_start(chan); 1625 } else if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) { 1626 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE) 1627 l2cap_chan_ready(chan); 1628 } else if (chan->state == BT_CONNECT) { 1629 l2cap_do_start(chan); 1630 } 1631 1632 l2cap_chan_unlock(chan); 1633 } 1634 1635 mutex_unlock(&conn->chan_lock); 1636 1637 if (hcon->type == LE_LINK) 1638 l2cap_le_conn_ready(conn); 1639 1640 queue_work(hcon->hdev->workqueue, &conn->pending_rx_work); 1641 } 1642 1643 /* Notify sockets that we cannot guaranty reliability anymore */ 1644 static void l2cap_conn_unreliable(struct l2cap_conn *conn, int err) 1645 { 1646 struct l2cap_chan *chan; 1647 1648 BT_DBG("conn %p", conn); 1649 1650 mutex_lock(&conn->chan_lock); 1651 1652 list_for_each_entry(chan, &conn->chan_l, list) { 1653 if (test_bit(FLAG_FORCE_RELIABLE, &chan->flags)) 1654 l2cap_chan_set_err(chan, err); 1655 } 1656 1657 mutex_unlock(&conn->chan_lock); 1658 } 1659 1660 static void l2cap_info_timeout(struct work_struct *work) 1661 { 1662 struct l2cap_conn *conn = container_of(work, struct l2cap_conn, 1663 info_timer.work); 1664 1665 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE; 1666 conn->info_ident = 0; 1667 1668 l2cap_conn_start(conn); 1669 } 1670 1671 /* 1672 * l2cap_user 1673 * External modules can register l2cap_user objects on l2cap_conn. The ->probe 1674 * callback is called during registration. The ->remove callback is called 1675 * during unregistration. 1676 * An l2cap_user object can either be explicitly unregistered or when the 1677 * underlying l2cap_conn object is deleted. This guarantees that l2cap->hcon, 1678 * l2cap->hchan, .. are valid as long as the remove callback hasn't been called. 1679 * External modules must own a reference to the l2cap_conn object if they intend 1680 * to call l2cap_unregister_user(). The l2cap_conn object might get destroyed at 1681 * any time if they don't. 1682 */ 1683 1684 int l2cap_register_user(struct l2cap_conn *conn, struct l2cap_user *user) 1685 { 1686 struct hci_dev *hdev = conn->hcon->hdev; 1687 int ret; 1688 1689 /* We need to check whether l2cap_conn is registered. If it is not, we 1690 * must not register the l2cap_user. l2cap_conn_del() is unregisters 1691 * l2cap_conn objects, but doesn't provide its own locking. Instead, it 1692 * relies on the parent hci_conn object to be locked. This itself relies 1693 * on the hci_dev object to be locked. So we must lock the hci device 1694 * here, too. */ 1695 1696 hci_dev_lock(hdev); 1697 1698 if (!list_empty(&user->list)) { 1699 ret = -EINVAL; 1700 goto out_unlock; 1701 } 1702 1703 /* conn->hchan is NULL after l2cap_conn_del() was called */ 1704 if (!conn->hchan) { 1705 ret = -ENODEV; 1706 goto out_unlock; 1707 } 1708 1709 ret = user->probe(conn, user); 1710 if (ret) 1711 goto out_unlock; 1712 1713 list_add(&user->list, &conn->users); 1714 ret = 0; 1715 1716 out_unlock: 1717 hci_dev_unlock(hdev); 1718 return ret; 1719 } 1720 EXPORT_SYMBOL(l2cap_register_user); 1721 1722 void l2cap_unregister_user(struct l2cap_conn *conn, struct l2cap_user *user) 1723 { 1724 struct hci_dev *hdev = conn->hcon->hdev; 1725 1726 hci_dev_lock(hdev); 1727 1728 if (list_empty(&user->list)) 1729 goto out_unlock; 1730 1731 list_del_init(&user->list); 1732 user->remove(conn, user); 1733 1734 out_unlock: 1735 hci_dev_unlock(hdev); 1736 } 1737 EXPORT_SYMBOL(l2cap_unregister_user); 1738 1739 static void l2cap_unregister_all_users(struct l2cap_conn *conn) 1740 { 1741 struct l2cap_user *user; 1742 1743 while (!list_empty(&conn->users)) { 1744 user = list_first_entry(&conn->users, struct l2cap_user, list); 1745 list_del_init(&user->list); 1746 user->remove(conn, user); 1747 } 1748 } 1749 1750 static void l2cap_conn_del(struct hci_conn *hcon, int err) 1751 { 1752 struct l2cap_conn *conn = hcon->l2cap_data; 1753 struct l2cap_chan *chan, *l; 1754 1755 if (!conn) 1756 return; 1757 1758 BT_DBG("hcon %p conn %p, err %d", hcon, conn, err); 1759 1760 kfree_skb(conn->rx_skb); 1761 1762 skb_queue_purge(&conn->pending_rx); 1763 1764 /* We can not call flush_work(&conn->pending_rx_work) here since we 1765 * might block if we are running on a worker from the same workqueue 1766 * pending_rx_work is waiting on. 1767 */ 1768 if (work_pending(&conn->pending_rx_work)) 1769 cancel_work_sync(&conn->pending_rx_work); 1770 1771 cancel_delayed_work_sync(&conn->id_addr_timer); 1772 1773 l2cap_unregister_all_users(conn); 1774 1775 /* Force the connection to be immediately dropped */ 1776 hcon->disc_timeout = 0; 1777 1778 mutex_lock(&conn->chan_lock); 1779 1780 /* Kill channels */ 1781 list_for_each_entry_safe(chan, l, &conn->chan_l, list) { 1782 l2cap_chan_hold(chan); 1783 l2cap_chan_lock(chan); 1784 1785 l2cap_chan_del(chan, err); 1786 1787 chan->ops->close(chan); 1788 1789 l2cap_chan_unlock(chan); 1790 l2cap_chan_put(chan); 1791 } 1792 1793 mutex_unlock(&conn->chan_lock); 1794 1795 hci_chan_del(conn->hchan); 1796 1797 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT) 1798 cancel_delayed_work_sync(&conn->info_timer); 1799 1800 hcon->l2cap_data = NULL; 1801 conn->hchan = NULL; 1802 l2cap_conn_put(conn); 1803 } 1804 1805 static void l2cap_conn_free(struct kref *ref) 1806 { 1807 struct l2cap_conn *conn = container_of(ref, struct l2cap_conn, ref); 1808 1809 hci_conn_put(conn->hcon); 1810 kfree(conn); 1811 } 1812 1813 struct l2cap_conn *l2cap_conn_get(struct l2cap_conn *conn) 1814 { 1815 kref_get(&conn->ref); 1816 return conn; 1817 } 1818 EXPORT_SYMBOL(l2cap_conn_get); 1819 1820 void l2cap_conn_put(struct l2cap_conn *conn) 1821 { 1822 kref_put(&conn->ref, l2cap_conn_free); 1823 } 1824 EXPORT_SYMBOL(l2cap_conn_put); 1825 1826 /* ---- Socket interface ---- */ 1827 1828 /* Find socket with psm and source / destination bdaddr. 1829 * Returns closest match. 1830 */ 1831 static struct l2cap_chan *l2cap_global_chan_by_psm(int state, __le16 psm, 1832 bdaddr_t *src, 1833 bdaddr_t *dst, 1834 u8 link_type) 1835 { 1836 struct l2cap_chan *c, *tmp, *c1 = NULL; 1837 1838 read_lock(&chan_list_lock); 1839 1840 list_for_each_entry_safe(c, tmp, &chan_list, global_l) { 1841 if (state && c->state != state) 1842 continue; 1843 1844 if (link_type == ACL_LINK && c->src_type != BDADDR_BREDR) 1845 continue; 1846 1847 if (link_type == LE_LINK && c->src_type == BDADDR_BREDR) 1848 continue; 1849 1850 if (c->chan_type != L2CAP_CHAN_FIXED && c->psm == psm) { 1851 int src_match, dst_match; 1852 int src_any, dst_any; 1853 1854 /* Exact match. */ 1855 src_match = !bacmp(&c->src, src); 1856 dst_match = !bacmp(&c->dst, dst); 1857 if (src_match && dst_match) { 1858 if (!l2cap_chan_hold_unless_zero(c)) 1859 continue; 1860 1861 read_unlock(&chan_list_lock); 1862 return c; 1863 } 1864 1865 /* Closest match */ 1866 src_any = !bacmp(&c->src, BDADDR_ANY); 1867 dst_any = !bacmp(&c->dst, BDADDR_ANY); 1868 if ((src_match && dst_any) || (src_any && dst_match) || 1869 (src_any && dst_any)) 1870 c1 = c; 1871 } 1872 } 1873 1874 if (c1) 1875 c1 = l2cap_chan_hold_unless_zero(c1); 1876 1877 read_unlock(&chan_list_lock); 1878 1879 return c1; 1880 } 1881 1882 static void l2cap_monitor_timeout(struct work_struct *work) 1883 { 1884 struct l2cap_chan *chan = container_of(work, struct l2cap_chan, 1885 monitor_timer.work); 1886 1887 BT_DBG("chan %p", chan); 1888 1889 l2cap_chan_lock(chan); 1890 1891 if (!chan->conn) { 1892 l2cap_chan_unlock(chan); 1893 l2cap_chan_put(chan); 1894 return; 1895 } 1896 1897 l2cap_tx(chan, NULL, NULL, L2CAP_EV_MONITOR_TO); 1898 1899 l2cap_chan_unlock(chan); 1900 l2cap_chan_put(chan); 1901 } 1902 1903 static void l2cap_retrans_timeout(struct work_struct *work) 1904 { 1905 struct l2cap_chan *chan = container_of(work, struct l2cap_chan, 1906 retrans_timer.work); 1907 1908 BT_DBG("chan %p", chan); 1909 1910 l2cap_chan_lock(chan); 1911 1912 if (!chan->conn) { 1913 l2cap_chan_unlock(chan); 1914 l2cap_chan_put(chan); 1915 return; 1916 } 1917 1918 l2cap_tx(chan, NULL, NULL, L2CAP_EV_RETRANS_TO); 1919 l2cap_chan_unlock(chan); 1920 l2cap_chan_put(chan); 1921 } 1922 1923 static void l2cap_streaming_send(struct l2cap_chan *chan, 1924 struct sk_buff_head *skbs) 1925 { 1926 struct sk_buff *skb; 1927 struct l2cap_ctrl *control; 1928 1929 BT_DBG("chan %p, skbs %p", chan, skbs); 1930 1931 skb_queue_splice_tail_init(skbs, &chan->tx_q); 1932 1933 while (!skb_queue_empty(&chan->tx_q)) { 1934 1935 skb = skb_dequeue(&chan->tx_q); 1936 1937 bt_cb(skb)->l2cap.retries = 1; 1938 control = &bt_cb(skb)->l2cap; 1939 1940 control->reqseq = 0; 1941 control->txseq = chan->next_tx_seq; 1942 1943 __pack_control(chan, control, skb); 1944 1945 if (chan->fcs == L2CAP_FCS_CRC16) { 1946 u16 fcs = crc16(0, (u8 *) skb->data, skb->len); 1947 put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE)); 1948 } 1949 1950 l2cap_do_send(chan, skb); 1951 1952 BT_DBG("Sent txseq %u", control->txseq); 1953 1954 chan->next_tx_seq = __next_seq(chan, chan->next_tx_seq); 1955 chan->frames_sent++; 1956 } 1957 } 1958 1959 static int l2cap_ertm_send(struct l2cap_chan *chan) 1960 { 1961 struct sk_buff *skb, *tx_skb; 1962 struct l2cap_ctrl *control; 1963 int sent = 0; 1964 1965 BT_DBG("chan %p", chan); 1966 1967 if (chan->state != BT_CONNECTED) 1968 return -ENOTCONN; 1969 1970 if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state)) 1971 return 0; 1972 1973 while (chan->tx_send_head && 1974 chan->unacked_frames < chan->remote_tx_win && 1975 chan->tx_state == L2CAP_TX_STATE_XMIT) { 1976 1977 skb = chan->tx_send_head; 1978 1979 bt_cb(skb)->l2cap.retries = 1; 1980 control = &bt_cb(skb)->l2cap; 1981 1982 if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state)) 1983 control->final = 1; 1984 1985 control->reqseq = chan->buffer_seq; 1986 chan->last_acked_seq = chan->buffer_seq; 1987 control->txseq = chan->next_tx_seq; 1988 1989 __pack_control(chan, control, skb); 1990 1991 if (chan->fcs == L2CAP_FCS_CRC16) { 1992 u16 fcs = crc16(0, (u8 *) skb->data, skb->len); 1993 put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE)); 1994 } 1995 1996 /* Clone after data has been modified. Data is assumed to be 1997 read-only (for locking purposes) on cloned sk_buffs. 1998 */ 1999 tx_skb = skb_clone(skb, GFP_KERNEL); 2000 2001 if (!tx_skb) 2002 break; 2003 2004 __set_retrans_timer(chan); 2005 2006 chan->next_tx_seq = __next_seq(chan, chan->next_tx_seq); 2007 chan->unacked_frames++; 2008 chan->frames_sent++; 2009 sent++; 2010 2011 if (skb_queue_is_last(&chan->tx_q, skb)) 2012 chan->tx_send_head = NULL; 2013 else 2014 chan->tx_send_head = skb_queue_next(&chan->tx_q, skb); 2015 2016 l2cap_do_send(chan, tx_skb); 2017 BT_DBG("Sent txseq %u", control->txseq); 2018 } 2019 2020 BT_DBG("Sent %d, %u unacked, %u in ERTM queue", sent, 2021 chan->unacked_frames, skb_queue_len(&chan->tx_q)); 2022 2023 return sent; 2024 } 2025 2026 static void l2cap_ertm_resend(struct l2cap_chan *chan) 2027 { 2028 struct l2cap_ctrl control; 2029 struct sk_buff *skb; 2030 struct sk_buff *tx_skb; 2031 u16 seq; 2032 2033 BT_DBG("chan %p", chan); 2034 2035 if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state)) 2036 return; 2037 2038 while (chan->retrans_list.head != L2CAP_SEQ_LIST_CLEAR) { 2039 seq = l2cap_seq_list_pop(&chan->retrans_list); 2040 2041 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, seq); 2042 if (!skb) { 2043 BT_DBG("Error: Can't retransmit seq %d, frame missing", 2044 seq); 2045 continue; 2046 } 2047 2048 bt_cb(skb)->l2cap.retries++; 2049 control = bt_cb(skb)->l2cap; 2050 2051 if (chan->max_tx != 0 && 2052 bt_cb(skb)->l2cap.retries > chan->max_tx) { 2053 BT_DBG("Retry limit exceeded (%d)", chan->max_tx); 2054 l2cap_send_disconn_req(chan, ECONNRESET); 2055 l2cap_seq_list_clear(&chan->retrans_list); 2056 break; 2057 } 2058 2059 control.reqseq = chan->buffer_seq; 2060 if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state)) 2061 control.final = 1; 2062 else 2063 control.final = 0; 2064 2065 if (skb_cloned(skb)) { 2066 /* Cloned sk_buffs are read-only, so we need a 2067 * writeable copy 2068 */ 2069 tx_skb = skb_copy(skb, GFP_KERNEL); 2070 } else { 2071 tx_skb = skb_clone(skb, GFP_KERNEL); 2072 } 2073 2074 if (!tx_skb) { 2075 l2cap_seq_list_clear(&chan->retrans_list); 2076 break; 2077 } 2078 2079 /* Update skb contents */ 2080 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) { 2081 put_unaligned_le32(__pack_extended_control(&control), 2082 tx_skb->data + L2CAP_HDR_SIZE); 2083 } else { 2084 put_unaligned_le16(__pack_enhanced_control(&control), 2085 tx_skb->data + L2CAP_HDR_SIZE); 2086 } 2087 2088 /* Update FCS */ 2089 if (chan->fcs == L2CAP_FCS_CRC16) { 2090 u16 fcs = crc16(0, (u8 *) tx_skb->data, 2091 tx_skb->len - L2CAP_FCS_SIZE); 2092 put_unaligned_le16(fcs, skb_tail_pointer(tx_skb) - 2093 L2CAP_FCS_SIZE); 2094 } 2095 2096 l2cap_do_send(chan, tx_skb); 2097 2098 BT_DBG("Resent txseq %d", control.txseq); 2099 2100 chan->last_acked_seq = chan->buffer_seq; 2101 } 2102 } 2103 2104 static void l2cap_retransmit(struct l2cap_chan *chan, 2105 struct l2cap_ctrl *control) 2106 { 2107 BT_DBG("chan %p, control %p", chan, control); 2108 2109 l2cap_seq_list_append(&chan->retrans_list, control->reqseq); 2110 l2cap_ertm_resend(chan); 2111 } 2112 2113 static void l2cap_retransmit_all(struct l2cap_chan *chan, 2114 struct l2cap_ctrl *control) 2115 { 2116 struct sk_buff *skb; 2117 2118 BT_DBG("chan %p, control %p", chan, control); 2119 2120 if (control->poll) 2121 set_bit(CONN_SEND_FBIT, &chan->conn_state); 2122 2123 l2cap_seq_list_clear(&chan->retrans_list); 2124 2125 if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state)) 2126 return; 2127 2128 if (chan->unacked_frames) { 2129 skb_queue_walk(&chan->tx_q, skb) { 2130 if (bt_cb(skb)->l2cap.txseq == control->reqseq || 2131 skb == chan->tx_send_head) 2132 break; 2133 } 2134 2135 skb_queue_walk_from(&chan->tx_q, skb) { 2136 if (skb == chan->tx_send_head) 2137 break; 2138 2139 l2cap_seq_list_append(&chan->retrans_list, 2140 bt_cb(skb)->l2cap.txseq); 2141 } 2142 2143 l2cap_ertm_resend(chan); 2144 } 2145 } 2146 2147 static void l2cap_send_ack(struct l2cap_chan *chan) 2148 { 2149 struct l2cap_ctrl control; 2150 u16 frames_to_ack = __seq_offset(chan, chan->buffer_seq, 2151 chan->last_acked_seq); 2152 int threshold; 2153 2154 BT_DBG("chan %p last_acked_seq %d buffer_seq %d", 2155 chan, chan->last_acked_seq, chan->buffer_seq); 2156 2157 memset(&control, 0, sizeof(control)); 2158 control.sframe = 1; 2159 2160 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state) && 2161 chan->rx_state == L2CAP_RX_STATE_RECV) { 2162 __clear_ack_timer(chan); 2163 control.super = L2CAP_SUPER_RNR; 2164 control.reqseq = chan->buffer_seq; 2165 l2cap_send_sframe(chan, &control); 2166 } else { 2167 if (!test_bit(CONN_REMOTE_BUSY, &chan->conn_state)) { 2168 l2cap_ertm_send(chan); 2169 /* If any i-frames were sent, they included an ack */ 2170 if (chan->buffer_seq == chan->last_acked_seq) 2171 frames_to_ack = 0; 2172 } 2173 2174 /* Ack now if the window is 3/4ths full. 2175 * Calculate without mul or div 2176 */ 2177 threshold = chan->ack_win; 2178 threshold += threshold << 1; 2179 threshold >>= 2; 2180 2181 BT_DBG("frames_to_ack %u, threshold %d", frames_to_ack, 2182 threshold); 2183 2184 if (frames_to_ack >= threshold) { 2185 __clear_ack_timer(chan); 2186 control.super = L2CAP_SUPER_RR; 2187 control.reqseq = chan->buffer_seq; 2188 l2cap_send_sframe(chan, &control); 2189 frames_to_ack = 0; 2190 } 2191 2192 if (frames_to_ack) 2193 __set_ack_timer(chan); 2194 } 2195 } 2196 2197 static inline int l2cap_skbuff_fromiovec(struct l2cap_chan *chan, 2198 struct msghdr *msg, int len, 2199 int count, struct sk_buff *skb) 2200 { 2201 struct l2cap_conn *conn = chan->conn; 2202 struct sk_buff **frag; 2203 int sent = 0; 2204 2205 if (!copy_from_iter_full(skb_put(skb, count), count, &msg->msg_iter)) 2206 return -EFAULT; 2207 2208 sent += count; 2209 len -= count; 2210 2211 /* Continuation fragments (no L2CAP header) */ 2212 frag = &skb_shinfo(skb)->frag_list; 2213 while (len) { 2214 struct sk_buff *tmp; 2215 2216 count = min_t(unsigned int, conn->mtu, len); 2217 2218 tmp = chan->ops->alloc_skb(chan, 0, count, 2219 msg->msg_flags & MSG_DONTWAIT); 2220 if (IS_ERR(tmp)) 2221 return PTR_ERR(tmp); 2222 2223 *frag = tmp; 2224 2225 if (!copy_from_iter_full(skb_put(*frag, count), count, 2226 &msg->msg_iter)) 2227 return -EFAULT; 2228 2229 sent += count; 2230 len -= count; 2231 2232 skb->len += (*frag)->len; 2233 skb->data_len += (*frag)->len; 2234 2235 frag = &(*frag)->next; 2236 } 2237 2238 return sent; 2239 } 2240 2241 static struct sk_buff *l2cap_create_connless_pdu(struct l2cap_chan *chan, 2242 struct msghdr *msg, size_t len) 2243 { 2244 struct l2cap_conn *conn = chan->conn; 2245 struct sk_buff *skb; 2246 int err, count, hlen = L2CAP_HDR_SIZE + L2CAP_PSMLEN_SIZE; 2247 struct l2cap_hdr *lh; 2248 2249 BT_DBG("chan %p psm 0x%2.2x len %zu", chan, 2250 __le16_to_cpu(chan->psm), len); 2251 2252 count = min_t(unsigned int, (conn->mtu - hlen), len); 2253 2254 skb = chan->ops->alloc_skb(chan, hlen, count, 2255 msg->msg_flags & MSG_DONTWAIT); 2256 if (IS_ERR(skb)) 2257 return skb; 2258 2259 /* Create L2CAP header */ 2260 lh = skb_put(skb, L2CAP_HDR_SIZE); 2261 lh->cid = cpu_to_le16(chan->dcid); 2262 lh->len = cpu_to_le16(len + L2CAP_PSMLEN_SIZE); 2263 put_unaligned(chan->psm, (__le16 *) skb_put(skb, L2CAP_PSMLEN_SIZE)); 2264 2265 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb); 2266 if (unlikely(err < 0)) { 2267 kfree_skb(skb); 2268 return ERR_PTR(err); 2269 } 2270 return skb; 2271 } 2272 2273 static struct sk_buff *l2cap_create_basic_pdu(struct l2cap_chan *chan, 2274 struct msghdr *msg, size_t len) 2275 { 2276 struct l2cap_conn *conn = chan->conn; 2277 struct sk_buff *skb; 2278 int err, count; 2279 struct l2cap_hdr *lh; 2280 2281 BT_DBG("chan %p len %zu", chan, len); 2282 2283 count = min_t(unsigned int, (conn->mtu - L2CAP_HDR_SIZE), len); 2284 2285 skb = chan->ops->alloc_skb(chan, L2CAP_HDR_SIZE, count, 2286 msg->msg_flags & MSG_DONTWAIT); 2287 if (IS_ERR(skb)) 2288 return skb; 2289 2290 /* Create L2CAP header */ 2291 lh = skb_put(skb, L2CAP_HDR_SIZE); 2292 lh->cid = cpu_to_le16(chan->dcid); 2293 lh->len = cpu_to_le16(len); 2294 2295 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb); 2296 if (unlikely(err < 0)) { 2297 kfree_skb(skb); 2298 return ERR_PTR(err); 2299 } 2300 return skb; 2301 } 2302 2303 static struct sk_buff *l2cap_create_iframe_pdu(struct l2cap_chan *chan, 2304 struct msghdr *msg, size_t len, 2305 u16 sdulen) 2306 { 2307 struct l2cap_conn *conn = chan->conn; 2308 struct sk_buff *skb; 2309 int err, count, hlen; 2310 struct l2cap_hdr *lh; 2311 2312 BT_DBG("chan %p len %zu", chan, len); 2313 2314 if (!conn) 2315 return ERR_PTR(-ENOTCONN); 2316 2317 hlen = __ertm_hdr_size(chan); 2318 2319 if (sdulen) 2320 hlen += L2CAP_SDULEN_SIZE; 2321 2322 if (chan->fcs == L2CAP_FCS_CRC16) 2323 hlen += L2CAP_FCS_SIZE; 2324 2325 count = min_t(unsigned int, (conn->mtu - hlen), len); 2326 2327 skb = chan->ops->alloc_skb(chan, hlen, count, 2328 msg->msg_flags & MSG_DONTWAIT); 2329 if (IS_ERR(skb)) 2330 return skb; 2331 2332 /* Create L2CAP header */ 2333 lh = skb_put(skb, L2CAP_HDR_SIZE); 2334 lh->cid = cpu_to_le16(chan->dcid); 2335 lh->len = cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE)); 2336 2337 /* Control header is populated later */ 2338 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) 2339 put_unaligned_le32(0, skb_put(skb, L2CAP_EXT_CTRL_SIZE)); 2340 else 2341 put_unaligned_le16(0, skb_put(skb, L2CAP_ENH_CTRL_SIZE)); 2342 2343 if (sdulen) 2344 put_unaligned_le16(sdulen, skb_put(skb, L2CAP_SDULEN_SIZE)); 2345 2346 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb); 2347 if (unlikely(err < 0)) { 2348 kfree_skb(skb); 2349 return ERR_PTR(err); 2350 } 2351 2352 bt_cb(skb)->l2cap.fcs = chan->fcs; 2353 bt_cb(skb)->l2cap.retries = 0; 2354 return skb; 2355 } 2356 2357 static int l2cap_segment_sdu(struct l2cap_chan *chan, 2358 struct sk_buff_head *seg_queue, 2359 struct msghdr *msg, size_t len) 2360 { 2361 struct sk_buff *skb; 2362 u16 sdu_len; 2363 size_t pdu_len; 2364 u8 sar; 2365 2366 BT_DBG("chan %p, msg %p, len %zu", chan, msg, len); 2367 2368 /* It is critical that ERTM PDUs fit in a single HCI fragment, 2369 * so fragmented skbs are not used. The HCI layer's handling 2370 * of fragmented skbs is not compatible with ERTM's queueing. 2371 */ 2372 2373 /* PDU size is derived from the HCI MTU */ 2374 pdu_len = chan->conn->mtu; 2375 2376 /* Constrain PDU size for BR/EDR connections */ 2377 pdu_len = min_t(size_t, pdu_len, L2CAP_BREDR_MAX_PAYLOAD); 2378 2379 /* Adjust for largest possible L2CAP overhead. */ 2380 if (chan->fcs) 2381 pdu_len -= L2CAP_FCS_SIZE; 2382 2383 pdu_len -= __ertm_hdr_size(chan); 2384 2385 /* Remote device may have requested smaller PDUs */ 2386 pdu_len = min_t(size_t, pdu_len, chan->remote_mps); 2387 2388 if (len <= pdu_len) { 2389 sar = L2CAP_SAR_UNSEGMENTED; 2390 sdu_len = 0; 2391 pdu_len = len; 2392 } else { 2393 sar = L2CAP_SAR_START; 2394 sdu_len = len; 2395 } 2396 2397 while (len > 0) { 2398 skb = l2cap_create_iframe_pdu(chan, msg, pdu_len, sdu_len); 2399 2400 if (IS_ERR(skb)) { 2401 __skb_queue_purge(seg_queue); 2402 return PTR_ERR(skb); 2403 } 2404 2405 bt_cb(skb)->l2cap.sar = sar; 2406 __skb_queue_tail(seg_queue, skb); 2407 2408 len -= pdu_len; 2409 if (sdu_len) 2410 sdu_len = 0; 2411 2412 if (len <= pdu_len) { 2413 sar = L2CAP_SAR_END; 2414 pdu_len = len; 2415 } else { 2416 sar = L2CAP_SAR_CONTINUE; 2417 } 2418 } 2419 2420 return 0; 2421 } 2422 2423 static struct sk_buff *l2cap_create_le_flowctl_pdu(struct l2cap_chan *chan, 2424 struct msghdr *msg, 2425 size_t len, u16 sdulen) 2426 { 2427 struct l2cap_conn *conn = chan->conn; 2428 struct sk_buff *skb; 2429 int err, count, hlen; 2430 struct l2cap_hdr *lh; 2431 2432 BT_DBG("chan %p len %zu", chan, len); 2433 2434 if (!conn) 2435 return ERR_PTR(-ENOTCONN); 2436 2437 hlen = L2CAP_HDR_SIZE; 2438 2439 if (sdulen) 2440 hlen += L2CAP_SDULEN_SIZE; 2441 2442 count = min_t(unsigned int, (conn->mtu - hlen), len); 2443 2444 skb = chan->ops->alloc_skb(chan, hlen, count, 2445 msg->msg_flags & MSG_DONTWAIT); 2446 if (IS_ERR(skb)) 2447 return skb; 2448 2449 /* Create L2CAP header */ 2450 lh = skb_put(skb, L2CAP_HDR_SIZE); 2451 lh->cid = cpu_to_le16(chan->dcid); 2452 lh->len = cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE)); 2453 2454 if (sdulen) 2455 put_unaligned_le16(sdulen, skb_put(skb, L2CAP_SDULEN_SIZE)); 2456 2457 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb); 2458 if (unlikely(err < 0)) { 2459 kfree_skb(skb); 2460 return ERR_PTR(err); 2461 } 2462 2463 return skb; 2464 } 2465 2466 static int l2cap_segment_le_sdu(struct l2cap_chan *chan, 2467 struct sk_buff_head *seg_queue, 2468 struct msghdr *msg, size_t len) 2469 { 2470 struct sk_buff *skb; 2471 size_t pdu_len; 2472 u16 sdu_len; 2473 2474 BT_DBG("chan %p, msg %p, len %zu", chan, msg, len); 2475 2476 sdu_len = len; 2477 pdu_len = chan->remote_mps - L2CAP_SDULEN_SIZE; 2478 2479 while (len > 0) { 2480 if (len <= pdu_len) 2481 pdu_len = len; 2482 2483 skb = l2cap_create_le_flowctl_pdu(chan, msg, pdu_len, sdu_len); 2484 if (IS_ERR(skb)) { 2485 __skb_queue_purge(seg_queue); 2486 return PTR_ERR(skb); 2487 } 2488 2489 __skb_queue_tail(seg_queue, skb); 2490 2491 len -= pdu_len; 2492 2493 if (sdu_len) { 2494 sdu_len = 0; 2495 pdu_len += L2CAP_SDULEN_SIZE; 2496 } 2497 } 2498 2499 return 0; 2500 } 2501 2502 static void l2cap_le_flowctl_send(struct l2cap_chan *chan) 2503 { 2504 int sent = 0; 2505 2506 BT_DBG("chan %p", chan); 2507 2508 while (chan->tx_credits && !skb_queue_empty(&chan->tx_q)) { 2509 l2cap_do_send(chan, skb_dequeue(&chan->tx_q)); 2510 chan->tx_credits--; 2511 sent++; 2512 } 2513 2514 BT_DBG("Sent %d credits %u queued %u", sent, chan->tx_credits, 2515 skb_queue_len(&chan->tx_q)); 2516 } 2517 2518 int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len) 2519 { 2520 struct sk_buff *skb; 2521 int err; 2522 struct sk_buff_head seg_queue; 2523 2524 if (!chan->conn) 2525 return -ENOTCONN; 2526 2527 /* Connectionless channel */ 2528 if (chan->chan_type == L2CAP_CHAN_CONN_LESS) { 2529 skb = l2cap_create_connless_pdu(chan, msg, len); 2530 if (IS_ERR(skb)) 2531 return PTR_ERR(skb); 2532 2533 l2cap_do_send(chan, skb); 2534 return len; 2535 } 2536 2537 switch (chan->mode) { 2538 case L2CAP_MODE_LE_FLOWCTL: 2539 case L2CAP_MODE_EXT_FLOWCTL: 2540 /* Check outgoing MTU */ 2541 if (len > chan->omtu) 2542 return -EMSGSIZE; 2543 2544 __skb_queue_head_init(&seg_queue); 2545 2546 err = l2cap_segment_le_sdu(chan, &seg_queue, msg, len); 2547 2548 if (chan->state != BT_CONNECTED) { 2549 __skb_queue_purge(&seg_queue); 2550 err = -ENOTCONN; 2551 } 2552 2553 if (err) 2554 return err; 2555 2556 skb_queue_splice_tail_init(&seg_queue, &chan->tx_q); 2557 2558 l2cap_le_flowctl_send(chan); 2559 2560 if (!chan->tx_credits) 2561 chan->ops->suspend(chan); 2562 2563 err = len; 2564 2565 break; 2566 2567 case L2CAP_MODE_BASIC: 2568 /* Check outgoing MTU */ 2569 if (len > chan->omtu) 2570 return -EMSGSIZE; 2571 2572 /* Create a basic PDU */ 2573 skb = l2cap_create_basic_pdu(chan, msg, len); 2574 if (IS_ERR(skb)) 2575 return PTR_ERR(skb); 2576 2577 l2cap_do_send(chan, skb); 2578 err = len; 2579 break; 2580 2581 case L2CAP_MODE_ERTM: 2582 case L2CAP_MODE_STREAMING: 2583 /* Check outgoing MTU */ 2584 if (len > chan->omtu) { 2585 err = -EMSGSIZE; 2586 break; 2587 } 2588 2589 __skb_queue_head_init(&seg_queue); 2590 2591 /* Do segmentation before calling in to the state machine, 2592 * since it's possible to block while waiting for memory 2593 * allocation. 2594 */ 2595 err = l2cap_segment_sdu(chan, &seg_queue, msg, len); 2596 2597 if (err) 2598 break; 2599 2600 if (chan->mode == L2CAP_MODE_ERTM) 2601 l2cap_tx(chan, NULL, &seg_queue, L2CAP_EV_DATA_REQUEST); 2602 else 2603 l2cap_streaming_send(chan, &seg_queue); 2604 2605 err = len; 2606 2607 /* If the skbs were not queued for sending, they'll still be in 2608 * seg_queue and need to be purged. 2609 */ 2610 __skb_queue_purge(&seg_queue); 2611 break; 2612 2613 default: 2614 BT_DBG("bad state %1.1x", chan->mode); 2615 err = -EBADFD; 2616 } 2617 2618 return err; 2619 } 2620 EXPORT_SYMBOL_GPL(l2cap_chan_send); 2621 2622 static void l2cap_send_srej(struct l2cap_chan *chan, u16 txseq) 2623 { 2624 struct l2cap_ctrl control; 2625 u16 seq; 2626 2627 BT_DBG("chan %p, txseq %u", chan, txseq); 2628 2629 memset(&control, 0, sizeof(control)); 2630 control.sframe = 1; 2631 control.super = L2CAP_SUPER_SREJ; 2632 2633 for (seq = chan->expected_tx_seq; seq != txseq; 2634 seq = __next_seq(chan, seq)) { 2635 if (!l2cap_ertm_seq_in_queue(&chan->srej_q, seq)) { 2636 control.reqseq = seq; 2637 l2cap_send_sframe(chan, &control); 2638 l2cap_seq_list_append(&chan->srej_list, seq); 2639 } 2640 } 2641 2642 chan->expected_tx_seq = __next_seq(chan, txseq); 2643 } 2644 2645 static void l2cap_send_srej_tail(struct l2cap_chan *chan) 2646 { 2647 struct l2cap_ctrl control; 2648 2649 BT_DBG("chan %p", chan); 2650 2651 if (chan->srej_list.tail == L2CAP_SEQ_LIST_CLEAR) 2652 return; 2653 2654 memset(&control, 0, sizeof(control)); 2655 control.sframe = 1; 2656 control.super = L2CAP_SUPER_SREJ; 2657 control.reqseq = chan->srej_list.tail; 2658 l2cap_send_sframe(chan, &control); 2659 } 2660 2661 static void l2cap_send_srej_list(struct l2cap_chan *chan, u16 txseq) 2662 { 2663 struct l2cap_ctrl control; 2664 u16 initial_head; 2665 u16 seq; 2666 2667 BT_DBG("chan %p, txseq %u", chan, txseq); 2668 2669 memset(&control, 0, sizeof(control)); 2670 control.sframe = 1; 2671 control.super = L2CAP_SUPER_SREJ; 2672 2673 /* Capture initial list head to allow only one pass through the list. */ 2674 initial_head = chan->srej_list.head; 2675 2676 do { 2677 seq = l2cap_seq_list_pop(&chan->srej_list); 2678 if (seq == txseq || seq == L2CAP_SEQ_LIST_CLEAR) 2679 break; 2680 2681 control.reqseq = seq; 2682 l2cap_send_sframe(chan, &control); 2683 l2cap_seq_list_append(&chan->srej_list, seq); 2684 } while (chan->srej_list.head != initial_head); 2685 } 2686 2687 static void l2cap_process_reqseq(struct l2cap_chan *chan, u16 reqseq) 2688 { 2689 struct sk_buff *acked_skb; 2690 u16 ackseq; 2691 2692 BT_DBG("chan %p, reqseq %u", chan, reqseq); 2693 2694 if (chan->unacked_frames == 0 || reqseq == chan->expected_ack_seq) 2695 return; 2696 2697 BT_DBG("expected_ack_seq %u, unacked_frames %u", 2698 chan->expected_ack_seq, chan->unacked_frames); 2699 2700 for (ackseq = chan->expected_ack_seq; ackseq != reqseq; 2701 ackseq = __next_seq(chan, ackseq)) { 2702 2703 acked_skb = l2cap_ertm_seq_in_queue(&chan->tx_q, ackseq); 2704 if (acked_skb) { 2705 skb_unlink(acked_skb, &chan->tx_q); 2706 kfree_skb(acked_skb); 2707 chan->unacked_frames--; 2708 } 2709 } 2710 2711 chan->expected_ack_seq = reqseq; 2712 2713 if (chan->unacked_frames == 0) 2714 __clear_retrans_timer(chan); 2715 2716 BT_DBG("unacked_frames %u", chan->unacked_frames); 2717 } 2718 2719 static void l2cap_abort_rx_srej_sent(struct l2cap_chan *chan) 2720 { 2721 BT_DBG("chan %p", chan); 2722 2723 chan->expected_tx_seq = chan->buffer_seq; 2724 l2cap_seq_list_clear(&chan->srej_list); 2725 skb_queue_purge(&chan->srej_q); 2726 chan->rx_state = L2CAP_RX_STATE_RECV; 2727 } 2728 2729 static void l2cap_tx_state_xmit(struct l2cap_chan *chan, 2730 struct l2cap_ctrl *control, 2731 struct sk_buff_head *skbs, u8 event) 2732 { 2733 BT_DBG("chan %p, control %p, skbs %p, event %d", chan, control, skbs, 2734 event); 2735 2736 switch (event) { 2737 case L2CAP_EV_DATA_REQUEST: 2738 if (chan->tx_send_head == NULL) 2739 chan->tx_send_head = skb_peek(skbs); 2740 2741 skb_queue_splice_tail_init(skbs, &chan->tx_q); 2742 l2cap_ertm_send(chan); 2743 break; 2744 case L2CAP_EV_LOCAL_BUSY_DETECTED: 2745 BT_DBG("Enter LOCAL_BUSY"); 2746 set_bit(CONN_LOCAL_BUSY, &chan->conn_state); 2747 2748 if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) { 2749 /* The SREJ_SENT state must be aborted if we are to 2750 * enter the LOCAL_BUSY state. 2751 */ 2752 l2cap_abort_rx_srej_sent(chan); 2753 } 2754 2755 l2cap_send_ack(chan); 2756 2757 break; 2758 case L2CAP_EV_LOCAL_BUSY_CLEAR: 2759 BT_DBG("Exit LOCAL_BUSY"); 2760 clear_bit(CONN_LOCAL_BUSY, &chan->conn_state); 2761 2762 if (test_bit(CONN_RNR_SENT, &chan->conn_state)) { 2763 struct l2cap_ctrl local_control; 2764 2765 memset(&local_control, 0, sizeof(local_control)); 2766 local_control.sframe = 1; 2767 local_control.super = L2CAP_SUPER_RR; 2768 local_control.poll = 1; 2769 local_control.reqseq = chan->buffer_seq; 2770 l2cap_send_sframe(chan, &local_control); 2771 2772 chan->retry_count = 1; 2773 __set_monitor_timer(chan); 2774 chan->tx_state = L2CAP_TX_STATE_WAIT_F; 2775 } 2776 break; 2777 case L2CAP_EV_RECV_REQSEQ_AND_FBIT: 2778 l2cap_process_reqseq(chan, control->reqseq); 2779 break; 2780 case L2CAP_EV_EXPLICIT_POLL: 2781 l2cap_send_rr_or_rnr(chan, 1); 2782 chan->retry_count = 1; 2783 __set_monitor_timer(chan); 2784 __clear_ack_timer(chan); 2785 chan->tx_state = L2CAP_TX_STATE_WAIT_F; 2786 break; 2787 case L2CAP_EV_RETRANS_TO: 2788 l2cap_send_rr_or_rnr(chan, 1); 2789 chan->retry_count = 1; 2790 __set_monitor_timer(chan); 2791 chan->tx_state = L2CAP_TX_STATE_WAIT_F; 2792 break; 2793 case L2CAP_EV_RECV_FBIT: 2794 /* Nothing to process */ 2795 break; 2796 default: 2797 break; 2798 } 2799 } 2800 2801 static void l2cap_tx_state_wait_f(struct l2cap_chan *chan, 2802 struct l2cap_ctrl *control, 2803 struct sk_buff_head *skbs, u8 event) 2804 { 2805 BT_DBG("chan %p, control %p, skbs %p, event %d", chan, control, skbs, 2806 event); 2807 2808 switch (event) { 2809 case L2CAP_EV_DATA_REQUEST: 2810 if (chan->tx_send_head == NULL) 2811 chan->tx_send_head = skb_peek(skbs); 2812 /* Queue data, but don't send. */ 2813 skb_queue_splice_tail_init(skbs, &chan->tx_q); 2814 break; 2815 case L2CAP_EV_LOCAL_BUSY_DETECTED: 2816 BT_DBG("Enter LOCAL_BUSY"); 2817 set_bit(CONN_LOCAL_BUSY, &chan->conn_state); 2818 2819 if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) { 2820 /* The SREJ_SENT state must be aborted if we are to 2821 * enter the LOCAL_BUSY state. 2822 */ 2823 l2cap_abort_rx_srej_sent(chan); 2824 } 2825 2826 l2cap_send_ack(chan); 2827 2828 break; 2829 case L2CAP_EV_LOCAL_BUSY_CLEAR: 2830 BT_DBG("Exit LOCAL_BUSY"); 2831 clear_bit(CONN_LOCAL_BUSY, &chan->conn_state); 2832 2833 if (test_bit(CONN_RNR_SENT, &chan->conn_state)) { 2834 struct l2cap_ctrl local_control; 2835 memset(&local_control, 0, sizeof(local_control)); 2836 local_control.sframe = 1; 2837 local_control.super = L2CAP_SUPER_RR; 2838 local_control.poll = 1; 2839 local_control.reqseq = chan->buffer_seq; 2840 l2cap_send_sframe(chan, &local_control); 2841 2842 chan->retry_count = 1; 2843 __set_monitor_timer(chan); 2844 chan->tx_state = L2CAP_TX_STATE_WAIT_F; 2845 } 2846 break; 2847 case L2CAP_EV_RECV_REQSEQ_AND_FBIT: 2848 l2cap_process_reqseq(chan, control->reqseq); 2849 fallthrough; 2850 2851 case L2CAP_EV_RECV_FBIT: 2852 if (control && control->final) { 2853 __clear_monitor_timer(chan); 2854 if (chan->unacked_frames > 0) 2855 __set_retrans_timer(chan); 2856 chan->retry_count = 0; 2857 chan->tx_state = L2CAP_TX_STATE_XMIT; 2858 BT_DBG("recv fbit tx_state 0x2.2%x", chan->tx_state); 2859 } 2860 break; 2861 case L2CAP_EV_EXPLICIT_POLL: 2862 /* Ignore */ 2863 break; 2864 case L2CAP_EV_MONITOR_TO: 2865 if (chan->max_tx == 0 || chan->retry_count < chan->max_tx) { 2866 l2cap_send_rr_or_rnr(chan, 1); 2867 __set_monitor_timer(chan); 2868 chan->retry_count++; 2869 } else { 2870 l2cap_send_disconn_req(chan, ECONNABORTED); 2871 } 2872 break; 2873 default: 2874 break; 2875 } 2876 } 2877 2878 static void l2cap_tx(struct l2cap_chan *chan, struct l2cap_ctrl *control, 2879 struct sk_buff_head *skbs, u8 event) 2880 { 2881 BT_DBG("chan %p, control %p, skbs %p, event %d, state %d", 2882 chan, control, skbs, event, chan->tx_state); 2883 2884 switch (chan->tx_state) { 2885 case L2CAP_TX_STATE_XMIT: 2886 l2cap_tx_state_xmit(chan, control, skbs, event); 2887 break; 2888 case L2CAP_TX_STATE_WAIT_F: 2889 l2cap_tx_state_wait_f(chan, control, skbs, event); 2890 break; 2891 default: 2892 /* Ignore event */ 2893 break; 2894 } 2895 } 2896 2897 static void l2cap_pass_to_tx(struct l2cap_chan *chan, 2898 struct l2cap_ctrl *control) 2899 { 2900 BT_DBG("chan %p, control %p", chan, control); 2901 l2cap_tx(chan, control, NULL, L2CAP_EV_RECV_REQSEQ_AND_FBIT); 2902 } 2903 2904 static void l2cap_pass_to_tx_fbit(struct l2cap_chan *chan, 2905 struct l2cap_ctrl *control) 2906 { 2907 BT_DBG("chan %p, control %p", chan, control); 2908 l2cap_tx(chan, control, NULL, L2CAP_EV_RECV_FBIT); 2909 } 2910 2911 /* Copy frame to all raw sockets on that connection */ 2912 static void l2cap_raw_recv(struct l2cap_conn *conn, struct sk_buff *skb) 2913 { 2914 struct sk_buff *nskb; 2915 struct l2cap_chan *chan; 2916 2917 BT_DBG("conn %p", conn); 2918 2919 mutex_lock(&conn->chan_lock); 2920 2921 list_for_each_entry(chan, &conn->chan_l, list) { 2922 if (chan->chan_type != L2CAP_CHAN_RAW) 2923 continue; 2924 2925 /* Don't send frame to the channel it came from */ 2926 if (bt_cb(skb)->l2cap.chan == chan) 2927 continue; 2928 2929 nskb = skb_clone(skb, GFP_KERNEL); 2930 if (!nskb) 2931 continue; 2932 if (chan->ops->recv(chan, nskb)) 2933 kfree_skb(nskb); 2934 } 2935 2936 mutex_unlock(&conn->chan_lock); 2937 } 2938 2939 /* ---- L2CAP signalling commands ---- */ 2940 static struct sk_buff *l2cap_build_cmd(struct l2cap_conn *conn, u8 code, 2941 u8 ident, u16 dlen, void *data) 2942 { 2943 struct sk_buff *skb, **frag; 2944 struct l2cap_cmd_hdr *cmd; 2945 struct l2cap_hdr *lh; 2946 int len, count; 2947 2948 BT_DBG("conn %p, code 0x%2.2x, ident 0x%2.2x, len %u", 2949 conn, code, ident, dlen); 2950 2951 if (conn->mtu < L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE) 2952 return NULL; 2953 2954 len = L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE + dlen; 2955 count = min_t(unsigned int, conn->mtu, len); 2956 2957 skb = bt_skb_alloc(count, GFP_KERNEL); 2958 if (!skb) 2959 return NULL; 2960 2961 lh = skb_put(skb, L2CAP_HDR_SIZE); 2962 lh->len = cpu_to_le16(L2CAP_CMD_HDR_SIZE + dlen); 2963 2964 if (conn->hcon->type == LE_LINK) 2965 lh->cid = cpu_to_le16(L2CAP_CID_LE_SIGNALING); 2966 else 2967 lh->cid = cpu_to_le16(L2CAP_CID_SIGNALING); 2968 2969 cmd = skb_put(skb, L2CAP_CMD_HDR_SIZE); 2970 cmd->code = code; 2971 cmd->ident = ident; 2972 cmd->len = cpu_to_le16(dlen); 2973 2974 if (dlen) { 2975 count -= L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE; 2976 skb_put_data(skb, data, count); 2977 data += count; 2978 } 2979 2980 len -= skb->len; 2981 2982 /* Continuation fragments (no L2CAP header) */ 2983 frag = &skb_shinfo(skb)->frag_list; 2984 while (len) { 2985 count = min_t(unsigned int, conn->mtu, len); 2986 2987 *frag = bt_skb_alloc(count, GFP_KERNEL); 2988 if (!*frag) 2989 goto fail; 2990 2991 skb_put_data(*frag, data, count); 2992 2993 len -= count; 2994 data += count; 2995 2996 frag = &(*frag)->next; 2997 } 2998 2999 return skb; 3000 3001 fail: 3002 kfree_skb(skb); 3003 return NULL; 3004 } 3005 3006 static inline int l2cap_get_conf_opt(void **ptr, int *type, int *olen, 3007 unsigned long *val) 3008 { 3009 struct l2cap_conf_opt *opt = *ptr; 3010 int len; 3011 3012 len = L2CAP_CONF_OPT_SIZE + opt->len; 3013 *ptr += len; 3014 3015 *type = opt->type; 3016 *olen = opt->len; 3017 3018 switch (opt->len) { 3019 case 1: 3020 *val = *((u8 *) opt->val); 3021 break; 3022 3023 case 2: 3024 *val = get_unaligned_le16(opt->val); 3025 break; 3026 3027 case 4: 3028 *val = get_unaligned_le32(opt->val); 3029 break; 3030 3031 default: 3032 *val = (unsigned long) opt->val; 3033 break; 3034 } 3035 3036 BT_DBG("type 0x%2.2x len %u val 0x%lx", *type, opt->len, *val); 3037 return len; 3038 } 3039 3040 static void l2cap_add_conf_opt(void **ptr, u8 type, u8 len, unsigned long val, size_t size) 3041 { 3042 struct l2cap_conf_opt *opt = *ptr; 3043 3044 BT_DBG("type 0x%2.2x len %u val 0x%lx", type, len, val); 3045 3046 if (size < L2CAP_CONF_OPT_SIZE + len) 3047 return; 3048 3049 opt->type = type; 3050 opt->len = len; 3051 3052 switch (len) { 3053 case 1: 3054 *((u8 *) opt->val) = val; 3055 break; 3056 3057 case 2: 3058 put_unaligned_le16(val, opt->val); 3059 break; 3060 3061 case 4: 3062 put_unaligned_le32(val, opt->val); 3063 break; 3064 3065 default: 3066 memcpy(opt->val, (void *) val, len); 3067 break; 3068 } 3069 3070 *ptr += L2CAP_CONF_OPT_SIZE + len; 3071 } 3072 3073 static void l2cap_add_opt_efs(void **ptr, struct l2cap_chan *chan, size_t size) 3074 { 3075 struct l2cap_conf_efs efs; 3076 3077 switch (chan->mode) { 3078 case L2CAP_MODE_ERTM: 3079 efs.id = chan->local_id; 3080 efs.stype = chan->local_stype; 3081 efs.msdu = cpu_to_le16(chan->local_msdu); 3082 efs.sdu_itime = cpu_to_le32(chan->local_sdu_itime); 3083 efs.acc_lat = cpu_to_le32(L2CAP_DEFAULT_ACC_LAT); 3084 efs.flush_to = cpu_to_le32(L2CAP_EFS_DEFAULT_FLUSH_TO); 3085 break; 3086 3087 case L2CAP_MODE_STREAMING: 3088 efs.id = 1; 3089 efs.stype = L2CAP_SERV_BESTEFFORT; 3090 efs.msdu = cpu_to_le16(chan->local_msdu); 3091 efs.sdu_itime = cpu_to_le32(chan->local_sdu_itime); 3092 efs.acc_lat = 0; 3093 efs.flush_to = 0; 3094 break; 3095 3096 default: 3097 return; 3098 } 3099 3100 l2cap_add_conf_opt(ptr, L2CAP_CONF_EFS, sizeof(efs), 3101 (unsigned long) &efs, size); 3102 } 3103 3104 static void l2cap_ack_timeout(struct work_struct *work) 3105 { 3106 struct l2cap_chan *chan = container_of(work, struct l2cap_chan, 3107 ack_timer.work); 3108 u16 frames_to_ack; 3109 3110 BT_DBG("chan %p", chan); 3111 3112 l2cap_chan_lock(chan); 3113 3114 frames_to_ack = __seq_offset(chan, chan->buffer_seq, 3115 chan->last_acked_seq); 3116 3117 if (frames_to_ack) 3118 l2cap_send_rr_or_rnr(chan, 0); 3119 3120 l2cap_chan_unlock(chan); 3121 l2cap_chan_put(chan); 3122 } 3123 3124 int l2cap_ertm_init(struct l2cap_chan *chan) 3125 { 3126 int err; 3127 3128 chan->next_tx_seq = 0; 3129 chan->expected_tx_seq = 0; 3130 chan->expected_ack_seq = 0; 3131 chan->unacked_frames = 0; 3132 chan->buffer_seq = 0; 3133 chan->frames_sent = 0; 3134 chan->last_acked_seq = 0; 3135 chan->sdu = NULL; 3136 chan->sdu_last_frag = NULL; 3137 chan->sdu_len = 0; 3138 3139 skb_queue_head_init(&chan->tx_q); 3140 3141 if (chan->mode != L2CAP_MODE_ERTM) 3142 return 0; 3143 3144 chan->rx_state = L2CAP_RX_STATE_RECV; 3145 chan->tx_state = L2CAP_TX_STATE_XMIT; 3146 3147 skb_queue_head_init(&chan->srej_q); 3148 3149 err = l2cap_seq_list_init(&chan->srej_list, chan->tx_win); 3150 if (err < 0) 3151 return err; 3152 3153 err = l2cap_seq_list_init(&chan->retrans_list, chan->remote_tx_win); 3154 if (err < 0) 3155 l2cap_seq_list_free(&chan->srej_list); 3156 3157 return err; 3158 } 3159 3160 static inline __u8 l2cap_select_mode(__u8 mode, __u16 remote_feat_mask) 3161 { 3162 switch (mode) { 3163 case L2CAP_MODE_STREAMING: 3164 case L2CAP_MODE_ERTM: 3165 if (l2cap_mode_supported(mode, remote_feat_mask)) 3166 return mode; 3167 fallthrough; 3168 default: 3169 return L2CAP_MODE_BASIC; 3170 } 3171 } 3172 3173 static inline bool __l2cap_ews_supported(struct l2cap_conn *conn) 3174 { 3175 return (conn->feat_mask & L2CAP_FEAT_EXT_WINDOW); 3176 } 3177 3178 static inline bool __l2cap_efs_supported(struct l2cap_conn *conn) 3179 { 3180 return (conn->feat_mask & L2CAP_FEAT_EXT_FLOW); 3181 } 3182 3183 static void __l2cap_set_ertm_timeouts(struct l2cap_chan *chan, 3184 struct l2cap_conf_rfc *rfc) 3185 { 3186 rfc->retrans_timeout = cpu_to_le16(L2CAP_DEFAULT_RETRANS_TO); 3187 rfc->monitor_timeout = cpu_to_le16(L2CAP_DEFAULT_MONITOR_TO); 3188 } 3189 3190 static inline void l2cap_txwin_setup(struct l2cap_chan *chan) 3191 { 3192 if (chan->tx_win > L2CAP_DEFAULT_TX_WINDOW && 3193 __l2cap_ews_supported(chan->conn)) { 3194 /* use extended control field */ 3195 set_bit(FLAG_EXT_CTRL, &chan->flags); 3196 chan->tx_win_max = L2CAP_DEFAULT_EXT_WINDOW; 3197 } else { 3198 chan->tx_win = min_t(u16, chan->tx_win, 3199 L2CAP_DEFAULT_TX_WINDOW); 3200 chan->tx_win_max = L2CAP_DEFAULT_TX_WINDOW; 3201 } 3202 chan->ack_win = chan->tx_win; 3203 } 3204 3205 static void l2cap_mtu_auto(struct l2cap_chan *chan) 3206 { 3207 struct hci_conn *conn = chan->conn->hcon; 3208 3209 chan->imtu = L2CAP_DEFAULT_MIN_MTU; 3210 3211 /* The 2-DH1 packet has between 2 and 56 information bytes 3212 * (including the 2-byte payload header) 3213 */ 3214 if (!(conn->pkt_type & HCI_2DH1)) 3215 chan->imtu = 54; 3216 3217 /* The 3-DH1 packet has between 2 and 85 information bytes 3218 * (including the 2-byte payload header) 3219 */ 3220 if (!(conn->pkt_type & HCI_3DH1)) 3221 chan->imtu = 83; 3222 3223 /* The 2-DH3 packet has between 2 and 369 information bytes 3224 * (including the 2-byte payload header) 3225 */ 3226 if (!(conn->pkt_type & HCI_2DH3)) 3227 chan->imtu = 367; 3228 3229 /* The 3-DH3 packet has between 2 and 554 information bytes 3230 * (including the 2-byte payload header) 3231 */ 3232 if (!(conn->pkt_type & HCI_3DH3)) 3233 chan->imtu = 552; 3234 3235 /* The 2-DH5 packet has between 2 and 681 information bytes 3236 * (including the 2-byte payload header) 3237 */ 3238 if (!(conn->pkt_type & HCI_2DH5)) 3239 chan->imtu = 679; 3240 3241 /* The 3-DH5 packet has between 2 and 1023 information bytes 3242 * (including the 2-byte payload header) 3243 */ 3244 if (!(conn->pkt_type & HCI_3DH5)) 3245 chan->imtu = 1021; 3246 } 3247 3248 static int l2cap_build_conf_req(struct l2cap_chan *chan, void *data, size_t data_size) 3249 { 3250 struct l2cap_conf_req *req = data; 3251 struct l2cap_conf_rfc rfc = { .mode = chan->mode }; 3252 void *ptr = req->data; 3253 void *endptr = data + data_size; 3254 u16 size; 3255 3256 BT_DBG("chan %p", chan); 3257 3258 if (chan->num_conf_req || chan->num_conf_rsp) 3259 goto done; 3260 3261 switch (chan->mode) { 3262 case L2CAP_MODE_STREAMING: 3263 case L2CAP_MODE_ERTM: 3264 if (test_bit(CONF_STATE2_DEVICE, &chan->conf_state)) 3265 break; 3266 3267 if (__l2cap_efs_supported(chan->conn)) 3268 set_bit(FLAG_EFS_ENABLE, &chan->flags); 3269 3270 fallthrough; 3271 default: 3272 chan->mode = l2cap_select_mode(rfc.mode, chan->conn->feat_mask); 3273 break; 3274 } 3275 3276 done: 3277 if (chan->imtu != L2CAP_DEFAULT_MTU) { 3278 if (!chan->imtu) 3279 l2cap_mtu_auto(chan); 3280 l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, chan->imtu, 3281 endptr - ptr); 3282 } 3283 3284 switch (chan->mode) { 3285 case L2CAP_MODE_BASIC: 3286 if (disable_ertm) 3287 break; 3288 3289 if (!(chan->conn->feat_mask & L2CAP_FEAT_ERTM) && 3290 !(chan->conn->feat_mask & L2CAP_FEAT_STREAMING)) 3291 break; 3292 3293 rfc.mode = L2CAP_MODE_BASIC; 3294 rfc.txwin_size = 0; 3295 rfc.max_transmit = 0; 3296 rfc.retrans_timeout = 0; 3297 rfc.monitor_timeout = 0; 3298 rfc.max_pdu_size = 0; 3299 3300 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc), 3301 (unsigned long) &rfc, endptr - ptr); 3302 break; 3303 3304 case L2CAP_MODE_ERTM: 3305 rfc.mode = L2CAP_MODE_ERTM; 3306 rfc.max_transmit = chan->max_tx; 3307 3308 __l2cap_set_ertm_timeouts(chan, &rfc); 3309 3310 size = min_t(u16, L2CAP_DEFAULT_MAX_PDU_SIZE, chan->conn->mtu - 3311 L2CAP_EXT_HDR_SIZE - L2CAP_SDULEN_SIZE - 3312 L2CAP_FCS_SIZE); 3313 rfc.max_pdu_size = cpu_to_le16(size); 3314 3315 l2cap_txwin_setup(chan); 3316 3317 rfc.txwin_size = min_t(u16, chan->tx_win, 3318 L2CAP_DEFAULT_TX_WINDOW); 3319 3320 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc), 3321 (unsigned long) &rfc, endptr - ptr); 3322 3323 if (test_bit(FLAG_EFS_ENABLE, &chan->flags)) 3324 l2cap_add_opt_efs(&ptr, chan, endptr - ptr); 3325 3326 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) 3327 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EWS, 2, 3328 chan->tx_win, endptr - ptr); 3329 3330 if (chan->conn->feat_mask & L2CAP_FEAT_FCS) 3331 if (chan->fcs == L2CAP_FCS_NONE || 3332 test_bit(CONF_RECV_NO_FCS, &chan->conf_state)) { 3333 chan->fcs = L2CAP_FCS_NONE; 3334 l2cap_add_conf_opt(&ptr, L2CAP_CONF_FCS, 1, 3335 chan->fcs, endptr - ptr); 3336 } 3337 break; 3338 3339 case L2CAP_MODE_STREAMING: 3340 l2cap_txwin_setup(chan); 3341 rfc.mode = L2CAP_MODE_STREAMING; 3342 rfc.txwin_size = 0; 3343 rfc.max_transmit = 0; 3344 rfc.retrans_timeout = 0; 3345 rfc.monitor_timeout = 0; 3346 3347 size = min_t(u16, L2CAP_DEFAULT_MAX_PDU_SIZE, chan->conn->mtu - 3348 L2CAP_EXT_HDR_SIZE - L2CAP_SDULEN_SIZE - 3349 L2CAP_FCS_SIZE); 3350 rfc.max_pdu_size = cpu_to_le16(size); 3351 3352 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc), 3353 (unsigned long) &rfc, endptr - ptr); 3354 3355 if (test_bit(FLAG_EFS_ENABLE, &chan->flags)) 3356 l2cap_add_opt_efs(&ptr, chan, endptr - ptr); 3357 3358 if (chan->conn->feat_mask & L2CAP_FEAT_FCS) 3359 if (chan->fcs == L2CAP_FCS_NONE || 3360 test_bit(CONF_RECV_NO_FCS, &chan->conf_state)) { 3361 chan->fcs = L2CAP_FCS_NONE; 3362 l2cap_add_conf_opt(&ptr, L2CAP_CONF_FCS, 1, 3363 chan->fcs, endptr - ptr); 3364 } 3365 break; 3366 } 3367 3368 req->dcid = cpu_to_le16(chan->dcid); 3369 req->flags = cpu_to_le16(0); 3370 3371 return ptr - data; 3372 } 3373 3374 static int l2cap_parse_conf_req(struct l2cap_chan *chan, void *data, size_t data_size) 3375 { 3376 struct l2cap_conf_rsp *rsp = data; 3377 void *ptr = rsp->data; 3378 void *endptr = data + data_size; 3379 void *req = chan->conf_req; 3380 int len = chan->conf_len; 3381 int type, hint, olen; 3382 unsigned long val; 3383 struct l2cap_conf_rfc rfc = { .mode = L2CAP_MODE_BASIC }; 3384 struct l2cap_conf_efs efs; 3385 u8 remote_efs = 0; 3386 u16 mtu = L2CAP_DEFAULT_MTU; 3387 u16 result = L2CAP_CONF_SUCCESS; 3388 u16 size; 3389 3390 BT_DBG("chan %p", chan); 3391 3392 while (len >= L2CAP_CONF_OPT_SIZE) { 3393 len -= l2cap_get_conf_opt(&req, &type, &olen, &val); 3394 if (len < 0) 3395 break; 3396 3397 hint = type & L2CAP_CONF_HINT; 3398 type &= L2CAP_CONF_MASK; 3399 3400 switch (type) { 3401 case L2CAP_CONF_MTU: 3402 if (olen != 2) 3403 break; 3404 mtu = val; 3405 break; 3406 3407 case L2CAP_CONF_FLUSH_TO: 3408 if (olen != 2) 3409 break; 3410 chan->flush_to = val; 3411 break; 3412 3413 case L2CAP_CONF_QOS: 3414 break; 3415 3416 case L2CAP_CONF_RFC: 3417 if (olen != sizeof(rfc)) 3418 break; 3419 memcpy(&rfc, (void *) val, olen); 3420 break; 3421 3422 case L2CAP_CONF_FCS: 3423 if (olen != 1) 3424 break; 3425 if (val == L2CAP_FCS_NONE) 3426 set_bit(CONF_RECV_NO_FCS, &chan->conf_state); 3427 break; 3428 3429 case L2CAP_CONF_EFS: 3430 if (olen != sizeof(efs)) 3431 break; 3432 remote_efs = 1; 3433 memcpy(&efs, (void *) val, olen); 3434 break; 3435 3436 case L2CAP_CONF_EWS: 3437 if (olen != 2) 3438 break; 3439 return -ECONNREFUSED; 3440 3441 default: 3442 if (hint) 3443 break; 3444 result = L2CAP_CONF_UNKNOWN; 3445 l2cap_add_conf_opt(&ptr, (u8)type, sizeof(u8), type, endptr - ptr); 3446 break; 3447 } 3448 } 3449 3450 if (chan->num_conf_rsp || chan->num_conf_req > 1) 3451 goto done; 3452 3453 switch (chan->mode) { 3454 case L2CAP_MODE_STREAMING: 3455 case L2CAP_MODE_ERTM: 3456 if (!test_bit(CONF_STATE2_DEVICE, &chan->conf_state)) { 3457 chan->mode = l2cap_select_mode(rfc.mode, 3458 chan->conn->feat_mask); 3459 break; 3460 } 3461 3462 if (remote_efs) { 3463 if (__l2cap_efs_supported(chan->conn)) 3464 set_bit(FLAG_EFS_ENABLE, &chan->flags); 3465 else 3466 return -ECONNREFUSED; 3467 } 3468 3469 if (chan->mode != rfc.mode) 3470 return -ECONNREFUSED; 3471 3472 break; 3473 } 3474 3475 done: 3476 if (chan->mode != rfc.mode) { 3477 result = L2CAP_CONF_UNACCEPT; 3478 rfc.mode = chan->mode; 3479 3480 if (chan->num_conf_rsp == 1) 3481 return -ECONNREFUSED; 3482 3483 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc), 3484 (unsigned long) &rfc, endptr - ptr); 3485 } 3486 3487 if (result == L2CAP_CONF_SUCCESS) { 3488 /* Configure output options and let the other side know 3489 * which ones we don't like. */ 3490 3491 if (mtu < L2CAP_DEFAULT_MIN_MTU) 3492 result = L2CAP_CONF_UNACCEPT; 3493 else { 3494 chan->omtu = mtu; 3495 set_bit(CONF_MTU_DONE, &chan->conf_state); 3496 } 3497 l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, chan->omtu, endptr - ptr); 3498 3499 if (remote_efs) { 3500 if (chan->local_stype != L2CAP_SERV_NOTRAFIC && 3501 efs.stype != L2CAP_SERV_NOTRAFIC && 3502 efs.stype != chan->local_stype) { 3503 3504 result = L2CAP_CONF_UNACCEPT; 3505 3506 if (chan->num_conf_req >= 1) 3507 return -ECONNREFUSED; 3508 3509 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS, 3510 sizeof(efs), 3511 (unsigned long) &efs, endptr - ptr); 3512 } else { 3513 /* Send PENDING Conf Rsp */ 3514 result = L2CAP_CONF_PENDING; 3515 set_bit(CONF_LOC_CONF_PEND, &chan->conf_state); 3516 } 3517 } 3518 3519 switch (rfc.mode) { 3520 case L2CAP_MODE_BASIC: 3521 chan->fcs = L2CAP_FCS_NONE; 3522 set_bit(CONF_MODE_DONE, &chan->conf_state); 3523 break; 3524 3525 case L2CAP_MODE_ERTM: 3526 if (!test_bit(CONF_EWS_RECV, &chan->conf_state)) 3527 chan->remote_tx_win = rfc.txwin_size; 3528 else 3529 rfc.txwin_size = L2CAP_DEFAULT_TX_WINDOW; 3530 3531 chan->remote_max_tx = rfc.max_transmit; 3532 3533 size = min_t(u16, le16_to_cpu(rfc.max_pdu_size), 3534 chan->conn->mtu - L2CAP_EXT_HDR_SIZE - 3535 L2CAP_SDULEN_SIZE - L2CAP_FCS_SIZE); 3536 rfc.max_pdu_size = cpu_to_le16(size); 3537 chan->remote_mps = size; 3538 3539 __l2cap_set_ertm_timeouts(chan, &rfc); 3540 3541 set_bit(CONF_MODE_DONE, &chan->conf_state); 3542 3543 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, 3544 sizeof(rfc), (unsigned long) &rfc, endptr - ptr); 3545 3546 if (remote_efs && 3547 test_bit(FLAG_EFS_ENABLE, &chan->flags)) { 3548 chan->remote_id = efs.id; 3549 chan->remote_stype = efs.stype; 3550 chan->remote_msdu = le16_to_cpu(efs.msdu); 3551 chan->remote_flush_to = 3552 le32_to_cpu(efs.flush_to); 3553 chan->remote_acc_lat = 3554 le32_to_cpu(efs.acc_lat); 3555 chan->remote_sdu_itime = 3556 le32_to_cpu(efs.sdu_itime); 3557 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS, 3558 sizeof(efs), 3559 (unsigned long) &efs, endptr - ptr); 3560 } 3561 break; 3562 3563 case L2CAP_MODE_STREAMING: 3564 size = min_t(u16, le16_to_cpu(rfc.max_pdu_size), 3565 chan->conn->mtu - L2CAP_EXT_HDR_SIZE - 3566 L2CAP_SDULEN_SIZE - L2CAP_FCS_SIZE); 3567 rfc.max_pdu_size = cpu_to_le16(size); 3568 chan->remote_mps = size; 3569 3570 set_bit(CONF_MODE_DONE, &chan->conf_state); 3571 3572 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc), 3573 (unsigned long) &rfc, endptr - ptr); 3574 3575 break; 3576 3577 default: 3578 result = L2CAP_CONF_UNACCEPT; 3579 3580 memset(&rfc, 0, sizeof(rfc)); 3581 rfc.mode = chan->mode; 3582 } 3583 3584 if (result == L2CAP_CONF_SUCCESS) 3585 set_bit(CONF_OUTPUT_DONE, &chan->conf_state); 3586 } 3587 rsp->scid = cpu_to_le16(chan->dcid); 3588 rsp->result = cpu_to_le16(result); 3589 rsp->flags = cpu_to_le16(0); 3590 3591 return ptr - data; 3592 } 3593 3594 static int l2cap_parse_conf_rsp(struct l2cap_chan *chan, void *rsp, int len, 3595 void *data, size_t size, u16 *result) 3596 { 3597 struct l2cap_conf_req *req = data; 3598 void *ptr = req->data; 3599 void *endptr = data + size; 3600 int type, olen; 3601 unsigned long val; 3602 struct l2cap_conf_rfc rfc = { .mode = L2CAP_MODE_BASIC }; 3603 struct l2cap_conf_efs efs; 3604 3605 BT_DBG("chan %p, rsp %p, len %d, req %p", chan, rsp, len, data); 3606 3607 while (len >= L2CAP_CONF_OPT_SIZE) { 3608 len -= l2cap_get_conf_opt(&rsp, &type, &olen, &val); 3609 if (len < 0) 3610 break; 3611 3612 switch (type) { 3613 case L2CAP_CONF_MTU: 3614 if (olen != 2) 3615 break; 3616 if (val < L2CAP_DEFAULT_MIN_MTU) { 3617 *result = L2CAP_CONF_UNACCEPT; 3618 chan->imtu = L2CAP_DEFAULT_MIN_MTU; 3619 } else 3620 chan->imtu = val; 3621 l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, chan->imtu, 3622 endptr - ptr); 3623 break; 3624 3625 case L2CAP_CONF_FLUSH_TO: 3626 if (olen != 2) 3627 break; 3628 chan->flush_to = val; 3629 l2cap_add_conf_opt(&ptr, L2CAP_CONF_FLUSH_TO, 2, 3630 chan->flush_to, endptr - ptr); 3631 break; 3632 3633 case L2CAP_CONF_RFC: 3634 if (olen != sizeof(rfc)) 3635 break; 3636 memcpy(&rfc, (void *)val, olen); 3637 if (test_bit(CONF_STATE2_DEVICE, &chan->conf_state) && 3638 rfc.mode != chan->mode) 3639 return -ECONNREFUSED; 3640 chan->fcs = 0; 3641 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc), 3642 (unsigned long) &rfc, endptr - ptr); 3643 break; 3644 3645 case L2CAP_CONF_EWS: 3646 if (olen != 2) 3647 break; 3648 chan->ack_win = min_t(u16, val, chan->ack_win); 3649 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EWS, 2, 3650 chan->tx_win, endptr - ptr); 3651 break; 3652 3653 case L2CAP_CONF_EFS: 3654 if (olen != sizeof(efs)) 3655 break; 3656 memcpy(&efs, (void *)val, olen); 3657 if (chan->local_stype != L2CAP_SERV_NOTRAFIC && 3658 efs.stype != L2CAP_SERV_NOTRAFIC && 3659 efs.stype != chan->local_stype) 3660 return -ECONNREFUSED; 3661 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS, sizeof(efs), 3662 (unsigned long) &efs, endptr - ptr); 3663 break; 3664 3665 case L2CAP_CONF_FCS: 3666 if (olen != 1) 3667 break; 3668 if (*result == L2CAP_CONF_PENDING) 3669 if (val == L2CAP_FCS_NONE) 3670 set_bit(CONF_RECV_NO_FCS, 3671 &chan->conf_state); 3672 break; 3673 } 3674 } 3675 3676 if (chan->mode == L2CAP_MODE_BASIC && chan->mode != rfc.mode) 3677 return -ECONNREFUSED; 3678 3679 chan->mode = rfc.mode; 3680 3681 if (*result == L2CAP_CONF_SUCCESS || *result == L2CAP_CONF_PENDING) { 3682 switch (rfc.mode) { 3683 case L2CAP_MODE_ERTM: 3684 chan->retrans_timeout = le16_to_cpu(rfc.retrans_timeout); 3685 chan->monitor_timeout = le16_to_cpu(rfc.monitor_timeout); 3686 chan->mps = le16_to_cpu(rfc.max_pdu_size); 3687 if (!test_bit(FLAG_EXT_CTRL, &chan->flags)) 3688 chan->ack_win = min_t(u16, chan->ack_win, 3689 rfc.txwin_size); 3690 3691 if (test_bit(FLAG_EFS_ENABLE, &chan->flags)) { 3692 chan->local_msdu = le16_to_cpu(efs.msdu); 3693 chan->local_sdu_itime = 3694 le32_to_cpu(efs.sdu_itime); 3695 chan->local_acc_lat = le32_to_cpu(efs.acc_lat); 3696 chan->local_flush_to = 3697 le32_to_cpu(efs.flush_to); 3698 } 3699 break; 3700 3701 case L2CAP_MODE_STREAMING: 3702 chan->mps = le16_to_cpu(rfc.max_pdu_size); 3703 } 3704 } 3705 3706 req->dcid = cpu_to_le16(chan->dcid); 3707 req->flags = cpu_to_le16(0); 3708 3709 return ptr - data; 3710 } 3711 3712 static int l2cap_build_conf_rsp(struct l2cap_chan *chan, void *data, 3713 u16 result, u16 flags) 3714 { 3715 struct l2cap_conf_rsp *rsp = data; 3716 void *ptr = rsp->data; 3717 3718 BT_DBG("chan %p", chan); 3719 3720 rsp->scid = cpu_to_le16(chan->dcid); 3721 rsp->result = cpu_to_le16(result); 3722 rsp->flags = cpu_to_le16(flags); 3723 3724 return ptr - data; 3725 } 3726 3727 void __l2cap_le_connect_rsp_defer(struct l2cap_chan *chan) 3728 { 3729 struct l2cap_le_conn_rsp rsp; 3730 struct l2cap_conn *conn = chan->conn; 3731 3732 BT_DBG("chan %p", chan); 3733 3734 rsp.dcid = cpu_to_le16(chan->scid); 3735 rsp.mtu = cpu_to_le16(chan->imtu); 3736 rsp.mps = cpu_to_le16(chan->mps); 3737 rsp.credits = cpu_to_le16(chan->rx_credits); 3738 rsp.result = cpu_to_le16(L2CAP_CR_LE_SUCCESS); 3739 3740 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_RSP, sizeof(rsp), 3741 &rsp); 3742 } 3743 3744 static void l2cap_ecred_list_defer(struct l2cap_chan *chan, void *data) 3745 { 3746 int *result = data; 3747 3748 if (*result || test_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags)) 3749 return; 3750 3751 switch (chan->state) { 3752 case BT_CONNECT2: 3753 /* If channel still pending accept add to result */ 3754 (*result)++; 3755 return; 3756 case BT_CONNECTED: 3757 return; 3758 default: 3759 /* If not connected or pending accept it has been refused */ 3760 *result = -ECONNREFUSED; 3761 return; 3762 } 3763 } 3764 3765 struct l2cap_ecred_rsp_data { 3766 struct { 3767 struct l2cap_ecred_conn_rsp rsp; 3768 __le16 scid[L2CAP_ECRED_MAX_CID]; 3769 } __packed pdu; 3770 int count; 3771 }; 3772 3773 static void l2cap_ecred_rsp_defer(struct l2cap_chan *chan, void *data) 3774 { 3775 struct l2cap_ecred_rsp_data *rsp = data; 3776 3777 if (test_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags)) 3778 return; 3779 3780 /* Reset ident so only one response is sent */ 3781 chan->ident = 0; 3782 3783 /* Include all channels pending with the same ident */ 3784 if (!rsp->pdu.rsp.result) 3785 rsp->pdu.rsp.dcid[rsp->count++] = cpu_to_le16(chan->scid); 3786 else 3787 l2cap_chan_del(chan, ECONNRESET); 3788 } 3789 3790 void __l2cap_ecred_conn_rsp_defer(struct l2cap_chan *chan) 3791 { 3792 struct l2cap_conn *conn = chan->conn; 3793 struct l2cap_ecred_rsp_data data; 3794 u16 id = chan->ident; 3795 int result = 0; 3796 3797 if (!id) 3798 return; 3799 3800 BT_DBG("chan %p id %d", chan, id); 3801 3802 memset(&data, 0, sizeof(data)); 3803 3804 data.pdu.rsp.mtu = cpu_to_le16(chan->imtu); 3805 data.pdu.rsp.mps = cpu_to_le16(chan->mps); 3806 data.pdu.rsp.credits = cpu_to_le16(chan->rx_credits); 3807 data.pdu.rsp.result = cpu_to_le16(L2CAP_CR_LE_SUCCESS); 3808 3809 /* Verify that all channels are ready */ 3810 __l2cap_chan_list_id(conn, id, l2cap_ecred_list_defer, &result); 3811 3812 if (result > 0) 3813 return; 3814 3815 if (result < 0) 3816 data.pdu.rsp.result = cpu_to_le16(L2CAP_CR_LE_AUTHORIZATION); 3817 3818 /* Build response */ 3819 __l2cap_chan_list_id(conn, id, l2cap_ecred_rsp_defer, &data); 3820 3821 l2cap_send_cmd(conn, id, L2CAP_ECRED_CONN_RSP, 3822 sizeof(data.pdu.rsp) + (data.count * sizeof(__le16)), 3823 &data.pdu); 3824 } 3825 3826 void __l2cap_connect_rsp_defer(struct l2cap_chan *chan) 3827 { 3828 struct l2cap_conn_rsp rsp; 3829 struct l2cap_conn *conn = chan->conn; 3830 u8 buf[128]; 3831 u8 rsp_code; 3832 3833 rsp.scid = cpu_to_le16(chan->dcid); 3834 rsp.dcid = cpu_to_le16(chan->scid); 3835 rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS); 3836 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO); 3837 rsp_code = L2CAP_CONN_RSP; 3838 3839 BT_DBG("chan %p rsp_code %u", chan, rsp_code); 3840 3841 l2cap_send_cmd(conn, chan->ident, rsp_code, sizeof(rsp), &rsp); 3842 3843 if (test_and_set_bit(CONF_REQ_SENT, &chan->conf_state)) 3844 return; 3845 3846 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ, 3847 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf); 3848 chan->num_conf_req++; 3849 } 3850 3851 static void l2cap_conf_rfc_get(struct l2cap_chan *chan, void *rsp, int len) 3852 { 3853 int type, olen; 3854 unsigned long val; 3855 /* Use sane default values in case a misbehaving remote device 3856 * did not send an RFC or extended window size option. 3857 */ 3858 u16 txwin_ext = chan->ack_win; 3859 struct l2cap_conf_rfc rfc = { 3860 .mode = chan->mode, 3861 .retrans_timeout = cpu_to_le16(L2CAP_DEFAULT_RETRANS_TO), 3862 .monitor_timeout = cpu_to_le16(L2CAP_DEFAULT_MONITOR_TO), 3863 .max_pdu_size = cpu_to_le16(chan->imtu), 3864 .txwin_size = min_t(u16, chan->ack_win, L2CAP_DEFAULT_TX_WINDOW), 3865 }; 3866 3867 BT_DBG("chan %p, rsp %p, len %d", chan, rsp, len); 3868 3869 if ((chan->mode != L2CAP_MODE_ERTM) && (chan->mode != L2CAP_MODE_STREAMING)) 3870 return; 3871 3872 while (len >= L2CAP_CONF_OPT_SIZE) { 3873 len -= l2cap_get_conf_opt(&rsp, &type, &olen, &val); 3874 if (len < 0) 3875 break; 3876 3877 switch (type) { 3878 case L2CAP_CONF_RFC: 3879 if (olen != sizeof(rfc)) 3880 break; 3881 memcpy(&rfc, (void *)val, olen); 3882 break; 3883 case L2CAP_CONF_EWS: 3884 if (olen != 2) 3885 break; 3886 txwin_ext = val; 3887 break; 3888 } 3889 } 3890 3891 switch (rfc.mode) { 3892 case L2CAP_MODE_ERTM: 3893 chan->retrans_timeout = le16_to_cpu(rfc.retrans_timeout); 3894 chan->monitor_timeout = le16_to_cpu(rfc.monitor_timeout); 3895 chan->mps = le16_to_cpu(rfc.max_pdu_size); 3896 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) 3897 chan->ack_win = min_t(u16, chan->ack_win, txwin_ext); 3898 else 3899 chan->ack_win = min_t(u16, chan->ack_win, 3900 rfc.txwin_size); 3901 break; 3902 case L2CAP_MODE_STREAMING: 3903 chan->mps = le16_to_cpu(rfc.max_pdu_size); 3904 } 3905 } 3906 3907 static inline int l2cap_command_rej(struct l2cap_conn *conn, 3908 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 3909 u8 *data) 3910 { 3911 struct l2cap_cmd_rej_unk *rej = (struct l2cap_cmd_rej_unk *) data; 3912 3913 if (cmd_len < sizeof(*rej)) 3914 return -EPROTO; 3915 3916 if (rej->reason != L2CAP_REJ_NOT_UNDERSTOOD) 3917 return 0; 3918 3919 if ((conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT) && 3920 cmd->ident == conn->info_ident) { 3921 cancel_delayed_work(&conn->info_timer); 3922 3923 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE; 3924 conn->info_ident = 0; 3925 3926 l2cap_conn_start(conn); 3927 } 3928 3929 return 0; 3930 } 3931 3932 static void l2cap_connect(struct l2cap_conn *conn, struct l2cap_cmd_hdr *cmd, 3933 u8 *data, u8 rsp_code) 3934 { 3935 struct l2cap_conn_req *req = (struct l2cap_conn_req *) data; 3936 struct l2cap_conn_rsp rsp; 3937 struct l2cap_chan *chan = NULL, *pchan = NULL; 3938 int result, status = L2CAP_CS_NO_INFO; 3939 3940 u16 dcid = 0, scid = __le16_to_cpu(req->scid); 3941 __le16 psm = req->psm; 3942 3943 BT_DBG("psm 0x%2.2x scid 0x%4.4x", __le16_to_cpu(psm), scid); 3944 3945 /* Check if we have socket listening on psm */ 3946 pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src, 3947 &conn->hcon->dst, ACL_LINK); 3948 if (!pchan) { 3949 result = L2CAP_CR_BAD_PSM; 3950 goto response; 3951 } 3952 3953 mutex_lock(&conn->chan_lock); 3954 l2cap_chan_lock(pchan); 3955 3956 /* Check if the ACL is secure enough (if not SDP) */ 3957 if (psm != cpu_to_le16(L2CAP_PSM_SDP) && 3958 !hci_conn_check_link_mode(conn->hcon)) { 3959 conn->disc_reason = HCI_ERROR_AUTH_FAILURE; 3960 result = L2CAP_CR_SEC_BLOCK; 3961 goto response; 3962 } 3963 3964 result = L2CAP_CR_NO_MEM; 3965 3966 /* Check for valid dynamic CID range (as per Erratum 3253) */ 3967 if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_DYN_END) { 3968 result = L2CAP_CR_INVALID_SCID; 3969 goto response; 3970 } 3971 3972 /* Check if we already have channel with that dcid */ 3973 if (__l2cap_get_chan_by_dcid(conn, scid)) { 3974 result = L2CAP_CR_SCID_IN_USE; 3975 goto response; 3976 } 3977 3978 chan = pchan->ops->new_connection(pchan); 3979 if (!chan) 3980 goto response; 3981 3982 /* For certain devices (ex: HID mouse), support for authentication, 3983 * pairing and bonding is optional. For such devices, inorder to avoid 3984 * the ACL alive for too long after L2CAP disconnection, reset the ACL 3985 * disc_timeout back to HCI_DISCONN_TIMEOUT during L2CAP connect. 3986 */ 3987 conn->hcon->disc_timeout = HCI_DISCONN_TIMEOUT; 3988 3989 bacpy(&chan->src, &conn->hcon->src); 3990 bacpy(&chan->dst, &conn->hcon->dst); 3991 chan->src_type = bdaddr_src_type(conn->hcon); 3992 chan->dst_type = bdaddr_dst_type(conn->hcon); 3993 chan->psm = psm; 3994 chan->dcid = scid; 3995 3996 __l2cap_chan_add(conn, chan); 3997 3998 dcid = chan->scid; 3999 4000 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan)); 4001 4002 chan->ident = cmd->ident; 4003 4004 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE) { 4005 if (l2cap_chan_check_security(chan, false)) { 4006 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) { 4007 l2cap_state_change(chan, BT_CONNECT2); 4008 result = L2CAP_CR_PEND; 4009 status = L2CAP_CS_AUTHOR_PEND; 4010 chan->ops->defer(chan); 4011 } else { 4012 l2cap_state_change(chan, BT_CONNECT2); 4013 result = L2CAP_CR_PEND; 4014 status = L2CAP_CS_NO_INFO; 4015 } 4016 } else { 4017 l2cap_state_change(chan, BT_CONNECT2); 4018 result = L2CAP_CR_PEND; 4019 status = L2CAP_CS_AUTHEN_PEND; 4020 } 4021 } else { 4022 l2cap_state_change(chan, BT_CONNECT2); 4023 result = L2CAP_CR_PEND; 4024 status = L2CAP_CS_NO_INFO; 4025 } 4026 4027 response: 4028 rsp.scid = cpu_to_le16(scid); 4029 rsp.dcid = cpu_to_le16(dcid); 4030 rsp.result = cpu_to_le16(result); 4031 rsp.status = cpu_to_le16(status); 4032 l2cap_send_cmd(conn, cmd->ident, rsp_code, sizeof(rsp), &rsp); 4033 4034 if (!pchan) 4035 return; 4036 4037 if (result == L2CAP_CR_PEND && status == L2CAP_CS_NO_INFO) { 4038 struct l2cap_info_req info; 4039 info.type = cpu_to_le16(L2CAP_IT_FEAT_MASK); 4040 4041 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_SENT; 4042 conn->info_ident = l2cap_get_ident(conn); 4043 4044 schedule_delayed_work(&conn->info_timer, L2CAP_INFO_TIMEOUT); 4045 4046 l2cap_send_cmd(conn, conn->info_ident, L2CAP_INFO_REQ, 4047 sizeof(info), &info); 4048 } 4049 4050 if (chan && !test_bit(CONF_REQ_SENT, &chan->conf_state) && 4051 result == L2CAP_CR_SUCCESS) { 4052 u8 buf[128]; 4053 set_bit(CONF_REQ_SENT, &chan->conf_state); 4054 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ, 4055 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf); 4056 chan->num_conf_req++; 4057 } 4058 4059 l2cap_chan_unlock(pchan); 4060 mutex_unlock(&conn->chan_lock); 4061 l2cap_chan_put(pchan); 4062 } 4063 4064 static int l2cap_connect_req(struct l2cap_conn *conn, 4065 struct l2cap_cmd_hdr *cmd, u16 cmd_len, u8 *data) 4066 { 4067 struct hci_dev *hdev = conn->hcon->hdev; 4068 struct hci_conn *hcon = conn->hcon; 4069 4070 if (cmd_len < sizeof(struct l2cap_conn_req)) 4071 return -EPROTO; 4072 4073 hci_dev_lock(hdev); 4074 if (hci_dev_test_flag(hdev, HCI_MGMT)) 4075 mgmt_device_connected(hdev, hcon, NULL, 0); 4076 hci_dev_unlock(hdev); 4077 4078 l2cap_connect(conn, cmd, data, L2CAP_CONN_RSP); 4079 return 0; 4080 } 4081 4082 static int l2cap_connect_create_rsp(struct l2cap_conn *conn, 4083 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4084 u8 *data) 4085 { 4086 struct l2cap_conn_rsp *rsp = (struct l2cap_conn_rsp *) data; 4087 u16 scid, dcid, result, status; 4088 struct l2cap_chan *chan; 4089 u8 req[128]; 4090 int err; 4091 4092 if (cmd_len < sizeof(*rsp)) 4093 return -EPROTO; 4094 4095 scid = __le16_to_cpu(rsp->scid); 4096 dcid = __le16_to_cpu(rsp->dcid); 4097 result = __le16_to_cpu(rsp->result); 4098 status = __le16_to_cpu(rsp->status); 4099 4100 if (result == L2CAP_CR_SUCCESS && (dcid < L2CAP_CID_DYN_START || 4101 dcid > L2CAP_CID_DYN_END)) 4102 return -EPROTO; 4103 4104 BT_DBG("dcid 0x%4.4x scid 0x%4.4x result 0x%2.2x status 0x%2.2x", 4105 dcid, scid, result, status); 4106 4107 mutex_lock(&conn->chan_lock); 4108 4109 if (scid) { 4110 chan = __l2cap_get_chan_by_scid(conn, scid); 4111 if (!chan) { 4112 err = -EBADSLT; 4113 goto unlock; 4114 } 4115 } else { 4116 chan = __l2cap_get_chan_by_ident(conn, cmd->ident); 4117 if (!chan) { 4118 err = -EBADSLT; 4119 goto unlock; 4120 } 4121 } 4122 4123 chan = l2cap_chan_hold_unless_zero(chan); 4124 if (!chan) { 4125 err = -EBADSLT; 4126 goto unlock; 4127 } 4128 4129 err = 0; 4130 4131 l2cap_chan_lock(chan); 4132 4133 switch (result) { 4134 case L2CAP_CR_SUCCESS: 4135 if (__l2cap_get_chan_by_dcid(conn, dcid)) { 4136 err = -EBADSLT; 4137 break; 4138 } 4139 4140 l2cap_state_change(chan, BT_CONFIG); 4141 chan->ident = 0; 4142 chan->dcid = dcid; 4143 clear_bit(CONF_CONNECT_PEND, &chan->conf_state); 4144 4145 if (test_and_set_bit(CONF_REQ_SENT, &chan->conf_state)) 4146 break; 4147 4148 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ, 4149 l2cap_build_conf_req(chan, req, sizeof(req)), req); 4150 chan->num_conf_req++; 4151 break; 4152 4153 case L2CAP_CR_PEND: 4154 set_bit(CONF_CONNECT_PEND, &chan->conf_state); 4155 break; 4156 4157 default: 4158 l2cap_chan_del(chan, ECONNREFUSED); 4159 break; 4160 } 4161 4162 l2cap_chan_unlock(chan); 4163 l2cap_chan_put(chan); 4164 4165 unlock: 4166 mutex_unlock(&conn->chan_lock); 4167 4168 return err; 4169 } 4170 4171 static inline void set_default_fcs(struct l2cap_chan *chan) 4172 { 4173 /* FCS is enabled only in ERTM or streaming mode, if one or both 4174 * sides request it. 4175 */ 4176 if (chan->mode != L2CAP_MODE_ERTM && chan->mode != L2CAP_MODE_STREAMING) 4177 chan->fcs = L2CAP_FCS_NONE; 4178 else if (!test_bit(CONF_RECV_NO_FCS, &chan->conf_state)) 4179 chan->fcs = L2CAP_FCS_CRC16; 4180 } 4181 4182 static void l2cap_send_efs_conf_rsp(struct l2cap_chan *chan, void *data, 4183 u8 ident, u16 flags) 4184 { 4185 struct l2cap_conn *conn = chan->conn; 4186 4187 BT_DBG("conn %p chan %p ident %d flags 0x%4.4x", conn, chan, ident, 4188 flags); 4189 4190 clear_bit(CONF_LOC_CONF_PEND, &chan->conf_state); 4191 set_bit(CONF_OUTPUT_DONE, &chan->conf_state); 4192 4193 l2cap_send_cmd(conn, ident, L2CAP_CONF_RSP, 4194 l2cap_build_conf_rsp(chan, data, 4195 L2CAP_CONF_SUCCESS, flags), data); 4196 } 4197 4198 static void cmd_reject_invalid_cid(struct l2cap_conn *conn, u8 ident, 4199 u16 scid, u16 dcid) 4200 { 4201 struct l2cap_cmd_rej_cid rej; 4202 4203 rej.reason = cpu_to_le16(L2CAP_REJ_INVALID_CID); 4204 rej.scid = __cpu_to_le16(scid); 4205 rej.dcid = __cpu_to_le16(dcid); 4206 4207 l2cap_send_cmd(conn, ident, L2CAP_COMMAND_REJ, sizeof(rej), &rej); 4208 } 4209 4210 static inline int l2cap_config_req(struct l2cap_conn *conn, 4211 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4212 u8 *data) 4213 { 4214 struct l2cap_conf_req *req = (struct l2cap_conf_req *) data; 4215 u16 dcid, flags; 4216 u8 rsp[64]; 4217 struct l2cap_chan *chan; 4218 int len, err = 0; 4219 4220 if (cmd_len < sizeof(*req)) 4221 return -EPROTO; 4222 4223 dcid = __le16_to_cpu(req->dcid); 4224 flags = __le16_to_cpu(req->flags); 4225 4226 BT_DBG("dcid 0x%4.4x flags 0x%2.2x", dcid, flags); 4227 4228 chan = l2cap_get_chan_by_scid(conn, dcid); 4229 if (!chan) { 4230 cmd_reject_invalid_cid(conn, cmd->ident, dcid, 0); 4231 return 0; 4232 } 4233 4234 if (chan->state != BT_CONFIG && chan->state != BT_CONNECT2 && 4235 chan->state != BT_CONNECTED) { 4236 cmd_reject_invalid_cid(conn, cmd->ident, chan->scid, 4237 chan->dcid); 4238 goto unlock; 4239 } 4240 4241 /* Reject if config buffer is too small. */ 4242 len = cmd_len - sizeof(*req); 4243 if (chan->conf_len + len > sizeof(chan->conf_req)) { 4244 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP, 4245 l2cap_build_conf_rsp(chan, rsp, 4246 L2CAP_CONF_REJECT, flags), rsp); 4247 goto unlock; 4248 } 4249 4250 /* Store config. */ 4251 memcpy(chan->conf_req + chan->conf_len, req->data, len); 4252 chan->conf_len += len; 4253 4254 if (flags & L2CAP_CONF_FLAG_CONTINUATION) { 4255 /* Incomplete config. Send empty response. */ 4256 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP, 4257 l2cap_build_conf_rsp(chan, rsp, 4258 L2CAP_CONF_SUCCESS, flags), rsp); 4259 goto unlock; 4260 } 4261 4262 /* Complete config. */ 4263 len = l2cap_parse_conf_req(chan, rsp, sizeof(rsp)); 4264 if (len < 0) { 4265 l2cap_send_disconn_req(chan, ECONNRESET); 4266 goto unlock; 4267 } 4268 4269 chan->ident = cmd->ident; 4270 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP, len, rsp); 4271 if (chan->num_conf_rsp < L2CAP_CONF_MAX_CONF_RSP) 4272 chan->num_conf_rsp++; 4273 4274 /* Reset config buffer. */ 4275 chan->conf_len = 0; 4276 4277 if (!test_bit(CONF_OUTPUT_DONE, &chan->conf_state)) 4278 goto unlock; 4279 4280 if (test_bit(CONF_INPUT_DONE, &chan->conf_state)) { 4281 set_default_fcs(chan); 4282 4283 if (chan->mode == L2CAP_MODE_ERTM || 4284 chan->mode == L2CAP_MODE_STREAMING) 4285 err = l2cap_ertm_init(chan); 4286 4287 if (err < 0) 4288 l2cap_send_disconn_req(chan, -err); 4289 else 4290 l2cap_chan_ready(chan); 4291 4292 goto unlock; 4293 } 4294 4295 if (!test_and_set_bit(CONF_REQ_SENT, &chan->conf_state)) { 4296 u8 buf[64]; 4297 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ, 4298 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf); 4299 chan->num_conf_req++; 4300 } 4301 4302 /* Got Conf Rsp PENDING from remote side and assume we sent 4303 Conf Rsp PENDING in the code above */ 4304 if (test_bit(CONF_REM_CONF_PEND, &chan->conf_state) && 4305 test_bit(CONF_LOC_CONF_PEND, &chan->conf_state)) { 4306 4307 /* check compatibility */ 4308 4309 /* Send rsp for BR/EDR channel */ 4310 l2cap_send_efs_conf_rsp(chan, rsp, cmd->ident, flags); 4311 } 4312 4313 unlock: 4314 l2cap_chan_unlock(chan); 4315 l2cap_chan_put(chan); 4316 return err; 4317 } 4318 4319 static inline int l2cap_config_rsp(struct l2cap_conn *conn, 4320 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4321 u8 *data) 4322 { 4323 struct l2cap_conf_rsp *rsp = (struct l2cap_conf_rsp *)data; 4324 u16 scid, flags, result; 4325 struct l2cap_chan *chan; 4326 int len = cmd_len - sizeof(*rsp); 4327 int err = 0; 4328 4329 if (cmd_len < sizeof(*rsp)) 4330 return -EPROTO; 4331 4332 scid = __le16_to_cpu(rsp->scid); 4333 flags = __le16_to_cpu(rsp->flags); 4334 result = __le16_to_cpu(rsp->result); 4335 4336 BT_DBG("scid 0x%4.4x flags 0x%2.2x result 0x%2.2x len %d", scid, flags, 4337 result, len); 4338 4339 chan = l2cap_get_chan_by_scid(conn, scid); 4340 if (!chan) 4341 return 0; 4342 4343 switch (result) { 4344 case L2CAP_CONF_SUCCESS: 4345 l2cap_conf_rfc_get(chan, rsp->data, len); 4346 clear_bit(CONF_REM_CONF_PEND, &chan->conf_state); 4347 break; 4348 4349 case L2CAP_CONF_PENDING: 4350 set_bit(CONF_REM_CONF_PEND, &chan->conf_state); 4351 4352 if (test_bit(CONF_LOC_CONF_PEND, &chan->conf_state)) { 4353 char buf[64]; 4354 4355 len = l2cap_parse_conf_rsp(chan, rsp->data, len, 4356 buf, sizeof(buf), &result); 4357 if (len < 0) { 4358 l2cap_send_disconn_req(chan, ECONNRESET); 4359 goto done; 4360 } 4361 4362 l2cap_send_efs_conf_rsp(chan, buf, cmd->ident, 0); 4363 } 4364 goto done; 4365 4366 case L2CAP_CONF_UNKNOWN: 4367 case L2CAP_CONF_UNACCEPT: 4368 if (chan->num_conf_rsp <= L2CAP_CONF_MAX_CONF_RSP) { 4369 char req[64]; 4370 4371 if (len > sizeof(req) - sizeof(struct l2cap_conf_req)) { 4372 l2cap_send_disconn_req(chan, ECONNRESET); 4373 goto done; 4374 } 4375 4376 /* throw out any old stored conf requests */ 4377 result = L2CAP_CONF_SUCCESS; 4378 len = l2cap_parse_conf_rsp(chan, rsp->data, len, 4379 req, sizeof(req), &result); 4380 if (len < 0) { 4381 l2cap_send_disconn_req(chan, ECONNRESET); 4382 goto done; 4383 } 4384 4385 l2cap_send_cmd(conn, l2cap_get_ident(conn), 4386 L2CAP_CONF_REQ, len, req); 4387 chan->num_conf_req++; 4388 if (result != L2CAP_CONF_SUCCESS) 4389 goto done; 4390 break; 4391 } 4392 fallthrough; 4393 4394 default: 4395 l2cap_chan_set_err(chan, ECONNRESET); 4396 4397 __set_chan_timer(chan, L2CAP_DISC_REJ_TIMEOUT); 4398 l2cap_send_disconn_req(chan, ECONNRESET); 4399 goto done; 4400 } 4401 4402 if (flags & L2CAP_CONF_FLAG_CONTINUATION) 4403 goto done; 4404 4405 set_bit(CONF_INPUT_DONE, &chan->conf_state); 4406 4407 if (test_bit(CONF_OUTPUT_DONE, &chan->conf_state)) { 4408 set_default_fcs(chan); 4409 4410 if (chan->mode == L2CAP_MODE_ERTM || 4411 chan->mode == L2CAP_MODE_STREAMING) 4412 err = l2cap_ertm_init(chan); 4413 4414 if (err < 0) 4415 l2cap_send_disconn_req(chan, -err); 4416 else 4417 l2cap_chan_ready(chan); 4418 } 4419 4420 done: 4421 l2cap_chan_unlock(chan); 4422 l2cap_chan_put(chan); 4423 return err; 4424 } 4425 4426 static inline int l2cap_disconnect_req(struct l2cap_conn *conn, 4427 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4428 u8 *data) 4429 { 4430 struct l2cap_disconn_req *req = (struct l2cap_disconn_req *) data; 4431 struct l2cap_disconn_rsp rsp; 4432 u16 dcid, scid; 4433 struct l2cap_chan *chan; 4434 4435 if (cmd_len != sizeof(*req)) 4436 return -EPROTO; 4437 4438 scid = __le16_to_cpu(req->scid); 4439 dcid = __le16_to_cpu(req->dcid); 4440 4441 BT_DBG("scid 0x%4.4x dcid 0x%4.4x", scid, dcid); 4442 4443 chan = l2cap_get_chan_by_scid(conn, dcid); 4444 if (!chan) { 4445 cmd_reject_invalid_cid(conn, cmd->ident, dcid, scid); 4446 return 0; 4447 } 4448 4449 rsp.dcid = cpu_to_le16(chan->scid); 4450 rsp.scid = cpu_to_le16(chan->dcid); 4451 l2cap_send_cmd(conn, cmd->ident, L2CAP_DISCONN_RSP, sizeof(rsp), &rsp); 4452 4453 chan->ops->set_shutdown(chan); 4454 4455 l2cap_chan_unlock(chan); 4456 mutex_lock(&conn->chan_lock); 4457 l2cap_chan_lock(chan); 4458 l2cap_chan_del(chan, ECONNRESET); 4459 mutex_unlock(&conn->chan_lock); 4460 4461 chan->ops->close(chan); 4462 4463 l2cap_chan_unlock(chan); 4464 l2cap_chan_put(chan); 4465 4466 return 0; 4467 } 4468 4469 static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn, 4470 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4471 u8 *data) 4472 { 4473 struct l2cap_disconn_rsp *rsp = (struct l2cap_disconn_rsp *) data; 4474 u16 dcid, scid; 4475 struct l2cap_chan *chan; 4476 4477 if (cmd_len != sizeof(*rsp)) 4478 return -EPROTO; 4479 4480 scid = __le16_to_cpu(rsp->scid); 4481 dcid = __le16_to_cpu(rsp->dcid); 4482 4483 BT_DBG("dcid 0x%4.4x scid 0x%4.4x", dcid, scid); 4484 4485 chan = l2cap_get_chan_by_scid(conn, scid); 4486 if (!chan) { 4487 return 0; 4488 } 4489 4490 if (chan->state != BT_DISCONN) { 4491 l2cap_chan_unlock(chan); 4492 l2cap_chan_put(chan); 4493 return 0; 4494 } 4495 4496 l2cap_chan_unlock(chan); 4497 mutex_lock(&conn->chan_lock); 4498 l2cap_chan_lock(chan); 4499 l2cap_chan_del(chan, 0); 4500 mutex_unlock(&conn->chan_lock); 4501 4502 chan->ops->close(chan); 4503 4504 l2cap_chan_unlock(chan); 4505 l2cap_chan_put(chan); 4506 4507 return 0; 4508 } 4509 4510 static inline int l2cap_information_req(struct l2cap_conn *conn, 4511 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4512 u8 *data) 4513 { 4514 struct l2cap_info_req *req = (struct l2cap_info_req *) data; 4515 u16 type; 4516 4517 if (cmd_len != sizeof(*req)) 4518 return -EPROTO; 4519 4520 type = __le16_to_cpu(req->type); 4521 4522 BT_DBG("type 0x%4.4x", type); 4523 4524 if (type == L2CAP_IT_FEAT_MASK) { 4525 u8 buf[8]; 4526 u32 feat_mask = l2cap_feat_mask; 4527 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) buf; 4528 rsp->type = cpu_to_le16(L2CAP_IT_FEAT_MASK); 4529 rsp->result = cpu_to_le16(L2CAP_IR_SUCCESS); 4530 if (!disable_ertm) 4531 feat_mask |= L2CAP_FEAT_ERTM | L2CAP_FEAT_STREAMING 4532 | L2CAP_FEAT_FCS; 4533 4534 put_unaligned_le32(feat_mask, rsp->data); 4535 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(buf), 4536 buf); 4537 } else if (type == L2CAP_IT_FIXED_CHAN) { 4538 u8 buf[12]; 4539 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) buf; 4540 4541 rsp->type = cpu_to_le16(L2CAP_IT_FIXED_CHAN); 4542 rsp->result = cpu_to_le16(L2CAP_IR_SUCCESS); 4543 rsp->data[0] = conn->local_fixed_chan; 4544 memset(rsp->data + 1, 0, 7); 4545 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(buf), 4546 buf); 4547 } else { 4548 struct l2cap_info_rsp rsp; 4549 rsp.type = cpu_to_le16(type); 4550 rsp.result = cpu_to_le16(L2CAP_IR_NOTSUPP); 4551 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(rsp), 4552 &rsp); 4553 } 4554 4555 return 0; 4556 } 4557 4558 static inline int l2cap_information_rsp(struct l2cap_conn *conn, 4559 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4560 u8 *data) 4561 { 4562 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) data; 4563 u16 type, result; 4564 4565 if (cmd_len < sizeof(*rsp)) 4566 return -EPROTO; 4567 4568 type = __le16_to_cpu(rsp->type); 4569 result = __le16_to_cpu(rsp->result); 4570 4571 BT_DBG("type 0x%4.4x result 0x%2.2x", type, result); 4572 4573 /* L2CAP Info req/rsp are unbound to channels, add extra checks */ 4574 if (cmd->ident != conn->info_ident || 4575 conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE) 4576 return 0; 4577 4578 cancel_delayed_work(&conn->info_timer); 4579 4580 if (result != L2CAP_IR_SUCCESS) { 4581 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE; 4582 conn->info_ident = 0; 4583 4584 l2cap_conn_start(conn); 4585 4586 return 0; 4587 } 4588 4589 switch (type) { 4590 case L2CAP_IT_FEAT_MASK: 4591 conn->feat_mask = get_unaligned_le32(rsp->data); 4592 4593 if (conn->feat_mask & L2CAP_FEAT_FIXED_CHAN) { 4594 struct l2cap_info_req req; 4595 req.type = cpu_to_le16(L2CAP_IT_FIXED_CHAN); 4596 4597 conn->info_ident = l2cap_get_ident(conn); 4598 4599 l2cap_send_cmd(conn, conn->info_ident, 4600 L2CAP_INFO_REQ, sizeof(req), &req); 4601 } else { 4602 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE; 4603 conn->info_ident = 0; 4604 4605 l2cap_conn_start(conn); 4606 } 4607 break; 4608 4609 case L2CAP_IT_FIXED_CHAN: 4610 conn->remote_fixed_chan = rsp->data[0]; 4611 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE; 4612 conn->info_ident = 0; 4613 4614 l2cap_conn_start(conn); 4615 break; 4616 } 4617 4618 return 0; 4619 } 4620 4621 static inline int l2cap_conn_param_update_req(struct l2cap_conn *conn, 4622 struct l2cap_cmd_hdr *cmd, 4623 u16 cmd_len, u8 *data) 4624 { 4625 struct hci_conn *hcon = conn->hcon; 4626 struct l2cap_conn_param_update_req *req; 4627 struct l2cap_conn_param_update_rsp rsp; 4628 u16 min, max, latency, to_multiplier; 4629 int err; 4630 4631 if (hcon->role != HCI_ROLE_MASTER) 4632 return -EINVAL; 4633 4634 if (cmd_len != sizeof(struct l2cap_conn_param_update_req)) 4635 return -EPROTO; 4636 4637 req = (struct l2cap_conn_param_update_req *) data; 4638 min = __le16_to_cpu(req->min); 4639 max = __le16_to_cpu(req->max); 4640 latency = __le16_to_cpu(req->latency); 4641 to_multiplier = __le16_to_cpu(req->to_multiplier); 4642 4643 BT_DBG("min 0x%4.4x max 0x%4.4x latency: 0x%4.4x Timeout: 0x%4.4x", 4644 min, max, latency, to_multiplier); 4645 4646 memset(&rsp, 0, sizeof(rsp)); 4647 4648 if (max > hcon->le_conn_max_interval) { 4649 BT_DBG("requested connection interval exceeds current bounds."); 4650 err = -EINVAL; 4651 } else { 4652 err = hci_check_conn_params(min, max, latency, to_multiplier); 4653 } 4654 4655 if (err) 4656 rsp.result = cpu_to_le16(L2CAP_CONN_PARAM_REJECTED); 4657 else 4658 rsp.result = cpu_to_le16(L2CAP_CONN_PARAM_ACCEPTED); 4659 4660 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONN_PARAM_UPDATE_RSP, 4661 sizeof(rsp), &rsp); 4662 4663 if (!err) { 4664 u8 store_hint; 4665 4666 store_hint = hci_le_conn_update(hcon, min, max, latency, 4667 to_multiplier); 4668 mgmt_new_conn_param(hcon->hdev, &hcon->dst, hcon->dst_type, 4669 store_hint, min, max, latency, 4670 to_multiplier); 4671 4672 } 4673 4674 return 0; 4675 } 4676 4677 static int l2cap_le_connect_rsp(struct l2cap_conn *conn, 4678 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4679 u8 *data) 4680 { 4681 struct l2cap_le_conn_rsp *rsp = (struct l2cap_le_conn_rsp *) data; 4682 struct hci_conn *hcon = conn->hcon; 4683 u16 dcid, mtu, mps, credits, result; 4684 struct l2cap_chan *chan; 4685 int err, sec_level; 4686 4687 if (cmd_len < sizeof(*rsp)) 4688 return -EPROTO; 4689 4690 dcid = __le16_to_cpu(rsp->dcid); 4691 mtu = __le16_to_cpu(rsp->mtu); 4692 mps = __le16_to_cpu(rsp->mps); 4693 credits = __le16_to_cpu(rsp->credits); 4694 result = __le16_to_cpu(rsp->result); 4695 4696 if (result == L2CAP_CR_LE_SUCCESS && (mtu < 23 || mps < 23 || 4697 dcid < L2CAP_CID_DYN_START || 4698 dcid > L2CAP_CID_LE_DYN_END)) 4699 return -EPROTO; 4700 4701 BT_DBG("dcid 0x%4.4x mtu %u mps %u credits %u result 0x%2.2x", 4702 dcid, mtu, mps, credits, result); 4703 4704 mutex_lock(&conn->chan_lock); 4705 4706 chan = __l2cap_get_chan_by_ident(conn, cmd->ident); 4707 if (!chan) { 4708 err = -EBADSLT; 4709 goto unlock; 4710 } 4711 4712 err = 0; 4713 4714 l2cap_chan_lock(chan); 4715 4716 switch (result) { 4717 case L2CAP_CR_LE_SUCCESS: 4718 if (__l2cap_get_chan_by_dcid(conn, dcid)) { 4719 err = -EBADSLT; 4720 break; 4721 } 4722 4723 chan->ident = 0; 4724 chan->dcid = dcid; 4725 chan->omtu = mtu; 4726 chan->remote_mps = mps; 4727 chan->tx_credits = credits; 4728 l2cap_chan_ready(chan); 4729 break; 4730 4731 case L2CAP_CR_LE_AUTHENTICATION: 4732 case L2CAP_CR_LE_ENCRYPTION: 4733 /* If we already have MITM protection we can't do 4734 * anything. 4735 */ 4736 if (hcon->sec_level > BT_SECURITY_MEDIUM) { 4737 l2cap_chan_del(chan, ECONNREFUSED); 4738 break; 4739 } 4740 4741 sec_level = hcon->sec_level + 1; 4742 if (chan->sec_level < sec_level) 4743 chan->sec_level = sec_level; 4744 4745 /* We'll need to send a new Connect Request */ 4746 clear_bit(FLAG_LE_CONN_REQ_SENT, &chan->flags); 4747 4748 smp_conn_security(hcon, chan->sec_level); 4749 break; 4750 4751 default: 4752 l2cap_chan_del(chan, ECONNREFUSED); 4753 break; 4754 } 4755 4756 l2cap_chan_unlock(chan); 4757 4758 unlock: 4759 mutex_unlock(&conn->chan_lock); 4760 4761 return err; 4762 } 4763 4764 static inline int l2cap_bredr_sig_cmd(struct l2cap_conn *conn, 4765 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4766 u8 *data) 4767 { 4768 int err = 0; 4769 4770 switch (cmd->code) { 4771 case L2CAP_COMMAND_REJ: 4772 l2cap_command_rej(conn, cmd, cmd_len, data); 4773 break; 4774 4775 case L2CAP_CONN_REQ: 4776 err = l2cap_connect_req(conn, cmd, cmd_len, data); 4777 break; 4778 4779 case L2CAP_CONN_RSP: 4780 l2cap_connect_create_rsp(conn, cmd, cmd_len, data); 4781 break; 4782 4783 case L2CAP_CONF_REQ: 4784 err = l2cap_config_req(conn, cmd, cmd_len, data); 4785 break; 4786 4787 case L2CAP_CONF_RSP: 4788 l2cap_config_rsp(conn, cmd, cmd_len, data); 4789 break; 4790 4791 case L2CAP_DISCONN_REQ: 4792 err = l2cap_disconnect_req(conn, cmd, cmd_len, data); 4793 break; 4794 4795 case L2CAP_DISCONN_RSP: 4796 l2cap_disconnect_rsp(conn, cmd, cmd_len, data); 4797 break; 4798 4799 case L2CAP_ECHO_REQ: 4800 l2cap_send_cmd(conn, cmd->ident, L2CAP_ECHO_RSP, cmd_len, data); 4801 break; 4802 4803 case L2CAP_ECHO_RSP: 4804 break; 4805 4806 case L2CAP_INFO_REQ: 4807 err = l2cap_information_req(conn, cmd, cmd_len, data); 4808 break; 4809 4810 case L2CAP_INFO_RSP: 4811 l2cap_information_rsp(conn, cmd, cmd_len, data); 4812 break; 4813 4814 default: 4815 BT_ERR("Unknown BR/EDR signaling command 0x%2.2x", cmd->code); 4816 err = -EINVAL; 4817 break; 4818 } 4819 4820 return err; 4821 } 4822 4823 static int l2cap_le_connect_req(struct l2cap_conn *conn, 4824 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4825 u8 *data) 4826 { 4827 struct l2cap_le_conn_req *req = (struct l2cap_le_conn_req *) data; 4828 struct l2cap_le_conn_rsp rsp; 4829 struct l2cap_chan *chan, *pchan; 4830 u16 dcid, scid, credits, mtu, mps; 4831 __le16 psm; 4832 u8 result; 4833 4834 if (cmd_len != sizeof(*req)) 4835 return -EPROTO; 4836 4837 scid = __le16_to_cpu(req->scid); 4838 mtu = __le16_to_cpu(req->mtu); 4839 mps = __le16_to_cpu(req->mps); 4840 psm = req->psm; 4841 dcid = 0; 4842 credits = 0; 4843 4844 if (mtu < 23 || mps < 23) 4845 return -EPROTO; 4846 4847 BT_DBG("psm 0x%2.2x scid 0x%4.4x mtu %u mps %u", __le16_to_cpu(psm), 4848 scid, mtu, mps); 4849 4850 /* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A 4851 * page 1059: 4852 * 4853 * Valid range: 0x0001-0x00ff 4854 * 4855 * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges 4856 */ 4857 if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) { 4858 result = L2CAP_CR_LE_BAD_PSM; 4859 chan = NULL; 4860 goto response; 4861 } 4862 4863 /* Check if we have socket listening on psm */ 4864 pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src, 4865 &conn->hcon->dst, LE_LINK); 4866 if (!pchan) { 4867 result = L2CAP_CR_LE_BAD_PSM; 4868 chan = NULL; 4869 goto response; 4870 } 4871 4872 mutex_lock(&conn->chan_lock); 4873 l2cap_chan_lock(pchan); 4874 4875 if (!smp_sufficient_security(conn->hcon, pchan->sec_level, 4876 SMP_ALLOW_STK)) { 4877 result = L2CAP_CR_LE_AUTHENTICATION; 4878 chan = NULL; 4879 goto response_unlock; 4880 } 4881 4882 /* Check for valid dynamic CID range */ 4883 if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_LE_DYN_END) { 4884 result = L2CAP_CR_LE_INVALID_SCID; 4885 chan = NULL; 4886 goto response_unlock; 4887 } 4888 4889 /* Check if we already have channel with that dcid */ 4890 if (__l2cap_get_chan_by_dcid(conn, scid)) { 4891 result = L2CAP_CR_LE_SCID_IN_USE; 4892 chan = NULL; 4893 goto response_unlock; 4894 } 4895 4896 chan = pchan->ops->new_connection(pchan); 4897 if (!chan) { 4898 result = L2CAP_CR_LE_NO_MEM; 4899 goto response_unlock; 4900 } 4901 4902 bacpy(&chan->src, &conn->hcon->src); 4903 bacpy(&chan->dst, &conn->hcon->dst); 4904 chan->src_type = bdaddr_src_type(conn->hcon); 4905 chan->dst_type = bdaddr_dst_type(conn->hcon); 4906 chan->psm = psm; 4907 chan->dcid = scid; 4908 chan->omtu = mtu; 4909 chan->remote_mps = mps; 4910 4911 __l2cap_chan_add(conn, chan); 4912 4913 l2cap_le_flowctl_init(chan, __le16_to_cpu(req->credits)); 4914 4915 dcid = chan->scid; 4916 credits = chan->rx_credits; 4917 4918 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan)); 4919 4920 chan->ident = cmd->ident; 4921 4922 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) { 4923 l2cap_state_change(chan, BT_CONNECT2); 4924 /* The following result value is actually not defined 4925 * for LE CoC but we use it to let the function know 4926 * that it should bail out after doing its cleanup 4927 * instead of sending a response. 4928 */ 4929 result = L2CAP_CR_PEND; 4930 chan->ops->defer(chan); 4931 } else { 4932 l2cap_chan_ready(chan); 4933 result = L2CAP_CR_LE_SUCCESS; 4934 } 4935 4936 response_unlock: 4937 l2cap_chan_unlock(pchan); 4938 mutex_unlock(&conn->chan_lock); 4939 l2cap_chan_put(pchan); 4940 4941 if (result == L2CAP_CR_PEND) 4942 return 0; 4943 4944 response: 4945 if (chan) { 4946 rsp.mtu = cpu_to_le16(chan->imtu); 4947 rsp.mps = cpu_to_le16(chan->mps); 4948 } else { 4949 rsp.mtu = 0; 4950 rsp.mps = 0; 4951 } 4952 4953 rsp.dcid = cpu_to_le16(dcid); 4954 rsp.credits = cpu_to_le16(credits); 4955 rsp.result = cpu_to_le16(result); 4956 4957 l2cap_send_cmd(conn, cmd->ident, L2CAP_LE_CONN_RSP, sizeof(rsp), &rsp); 4958 4959 return 0; 4960 } 4961 4962 static inline int l2cap_le_credits(struct l2cap_conn *conn, 4963 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4964 u8 *data) 4965 { 4966 struct l2cap_le_credits *pkt; 4967 struct l2cap_chan *chan; 4968 u16 cid, credits, max_credits; 4969 4970 if (cmd_len != sizeof(*pkt)) 4971 return -EPROTO; 4972 4973 pkt = (struct l2cap_le_credits *) data; 4974 cid = __le16_to_cpu(pkt->cid); 4975 credits = __le16_to_cpu(pkt->credits); 4976 4977 BT_DBG("cid 0x%4.4x credits 0x%4.4x", cid, credits); 4978 4979 chan = l2cap_get_chan_by_dcid(conn, cid); 4980 if (!chan) 4981 return -EBADSLT; 4982 4983 max_credits = LE_FLOWCTL_MAX_CREDITS - chan->tx_credits; 4984 if (credits > max_credits) { 4985 BT_ERR("LE credits overflow"); 4986 l2cap_send_disconn_req(chan, ECONNRESET); 4987 4988 /* Return 0 so that we don't trigger an unnecessary 4989 * command reject packet. 4990 */ 4991 goto unlock; 4992 } 4993 4994 chan->tx_credits += credits; 4995 4996 /* Resume sending */ 4997 l2cap_le_flowctl_send(chan); 4998 4999 if (chan->tx_credits) 5000 chan->ops->resume(chan); 5001 5002 unlock: 5003 l2cap_chan_unlock(chan); 5004 l2cap_chan_put(chan); 5005 5006 return 0; 5007 } 5008 5009 static inline int l2cap_ecred_conn_req(struct l2cap_conn *conn, 5010 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 5011 u8 *data) 5012 { 5013 struct l2cap_ecred_conn_req *req = (void *) data; 5014 struct { 5015 struct l2cap_ecred_conn_rsp rsp; 5016 __le16 dcid[L2CAP_ECRED_MAX_CID]; 5017 } __packed pdu; 5018 struct l2cap_chan *chan, *pchan; 5019 u16 mtu, mps; 5020 __le16 psm; 5021 u8 result, len = 0; 5022 int i, num_scid; 5023 bool defer = false; 5024 5025 if (!enable_ecred) 5026 return -EINVAL; 5027 5028 if (cmd_len < sizeof(*req) || (cmd_len - sizeof(*req)) % sizeof(u16)) { 5029 result = L2CAP_CR_LE_INVALID_PARAMS; 5030 goto response; 5031 } 5032 5033 cmd_len -= sizeof(*req); 5034 num_scid = cmd_len / sizeof(u16); 5035 5036 if (num_scid > ARRAY_SIZE(pdu.dcid)) { 5037 result = L2CAP_CR_LE_INVALID_PARAMS; 5038 goto response; 5039 } 5040 5041 mtu = __le16_to_cpu(req->mtu); 5042 mps = __le16_to_cpu(req->mps); 5043 5044 if (mtu < L2CAP_ECRED_MIN_MTU || mps < L2CAP_ECRED_MIN_MPS) { 5045 result = L2CAP_CR_LE_UNACCEPT_PARAMS; 5046 goto response; 5047 } 5048 5049 psm = req->psm; 5050 5051 /* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A 5052 * page 1059: 5053 * 5054 * Valid range: 0x0001-0x00ff 5055 * 5056 * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges 5057 */ 5058 if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) { 5059 result = L2CAP_CR_LE_BAD_PSM; 5060 goto response; 5061 } 5062 5063 BT_DBG("psm 0x%2.2x mtu %u mps %u", __le16_to_cpu(psm), mtu, mps); 5064 5065 memset(&pdu, 0, sizeof(pdu)); 5066 5067 /* Check if we have socket listening on psm */ 5068 pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src, 5069 &conn->hcon->dst, LE_LINK); 5070 if (!pchan) { 5071 result = L2CAP_CR_LE_BAD_PSM; 5072 goto response; 5073 } 5074 5075 mutex_lock(&conn->chan_lock); 5076 l2cap_chan_lock(pchan); 5077 5078 if (!smp_sufficient_security(conn->hcon, pchan->sec_level, 5079 SMP_ALLOW_STK)) { 5080 result = L2CAP_CR_LE_AUTHENTICATION; 5081 goto unlock; 5082 } 5083 5084 result = L2CAP_CR_LE_SUCCESS; 5085 5086 for (i = 0; i < num_scid; i++) { 5087 u16 scid = __le16_to_cpu(req->scid[i]); 5088 5089 BT_DBG("scid[%d] 0x%4.4x", i, scid); 5090 5091 pdu.dcid[i] = 0x0000; 5092 len += sizeof(*pdu.dcid); 5093 5094 /* Check for valid dynamic CID range */ 5095 if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_LE_DYN_END) { 5096 result = L2CAP_CR_LE_INVALID_SCID; 5097 continue; 5098 } 5099 5100 /* Check if we already have channel with that dcid */ 5101 if (__l2cap_get_chan_by_dcid(conn, scid)) { 5102 result = L2CAP_CR_LE_SCID_IN_USE; 5103 continue; 5104 } 5105 5106 chan = pchan->ops->new_connection(pchan); 5107 if (!chan) { 5108 result = L2CAP_CR_LE_NO_MEM; 5109 continue; 5110 } 5111 5112 bacpy(&chan->src, &conn->hcon->src); 5113 bacpy(&chan->dst, &conn->hcon->dst); 5114 chan->src_type = bdaddr_src_type(conn->hcon); 5115 chan->dst_type = bdaddr_dst_type(conn->hcon); 5116 chan->psm = psm; 5117 chan->dcid = scid; 5118 chan->omtu = mtu; 5119 chan->remote_mps = mps; 5120 5121 __l2cap_chan_add(conn, chan); 5122 5123 l2cap_ecred_init(chan, __le16_to_cpu(req->credits)); 5124 5125 /* Init response */ 5126 if (!pdu.rsp.credits) { 5127 pdu.rsp.mtu = cpu_to_le16(chan->imtu); 5128 pdu.rsp.mps = cpu_to_le16(chan->mps); 5129 pdu.rsp.credits = cpu_to_le16(chan->rx_credits); 5130 } 5131 5132 pdu.dcid[i] = cpu_to_le16(chan->scid); 5133 5134 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan)); 5135 5136 chan->ident = cmd->ident; 5137 chan->mode = L2CAP_MODE_EXT_FLOWCTL; 5138 5139 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) { 5140 l2cap_state_change(chan, BT_CONNECT2); 5141 defer = true; 5142 chan->ops->defer(chan); 5143 } else { 5144 l2cap_chan_ready(chan); 5145 } 5146 } 5147 5148 unlock: 5149 l2cap_chan_unlock(pchan); 5150 mutex_unlock(&conn->chan_lock); 5151 l2cap_chan_put(pchan); 5152 5153 response: 5154 pdu.rsp.result = cpu_to_le16(result); 5155 5156 if (defer) 5157 return 0; 5158 5159 l2cap_send_cmd(conn, cmd->ident, L2CAP_ECRED_CONN_RSP, 5160 sizeof(pdu.rsp) + len, &pdu); 5161 5162 return 0; 5163 } 5164 5165 static inline int l2cap_ecred_conn_rsp(struct l2cap_conn *conn, 5166 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 5167 u8 *data) 5168 { 5169 struct l2cap_ecred_conn_rsp *rsp = (void *) data; 5170 struct hci_conn *hcon = conn->hcon; 5171 u16 mtu, mps, credits, result; 5172 struct l2cap_chan *chan, *tmp; 5173 int err = 0, sec_level; 5174 int i = 0; 5175 5176 if (cmd_len < sizeof(*rsp)) 5177 return -EPROTO; 5178 5179 mtu = __le16_to_cpu(rsp->mtu); 5180 mps = __le16_to_cpu(rsp->mps); 5181 credits = __le16_to_cpu(rsp->credits); 5182 result = __le16_to_cpu(rsp->result); 5183 5184 BT_DBG("mtu %u mps %u credits %u result 0x%4.4x", mtu, mps, credits, 5185 result); 5186 5187 mutex_lock(&conn->chan_lock); 5188 5189 cmd_len -= sizeof(*rsp); 5190 5191 list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) { 5192 u16 dcid; 5193 5194 if (chan->ident != cmd->ident || 5195 chan->mode != L2CAP_MODE_EXT_FLOWCTL || 5196 chan->state == BT_CONNECTED) 5197 continue; 5198 5199 l2cap_chan_lock(chan); 5200 5201 /* Check that there is a dcid for each pending channel */ 5202 if (cmd_len < sizeof(dcid)) { 5203 l2cap_chan_del(chan, ECONNREFUSED); 5204 l2cap_chan_unlock(chan); 5205 continue; 5206 } 5207 5208 dcid = __le16_to_cpu(rsp->dcid[i++]); 5209 cmd_len -= sizeof(u16); 5210 5211 BT_DBG("dcid[%d] 0x%4.4x", i, dcid); 5212 5213 /* Check if dcid is already in use */ 5214 if (dcid && __l2cap_get_chan_by_dcid(conn, dcid)) { 5215 /* If a device receives a 5216 * L2CAP_CREDIT_BASED_CONNECTION_RSP packet with an 5217 * already-assigned Destination CID, then both the 5218 * original channel and the new channel shall be 5219 * immediately discarded and not used. 5220 */ 5221 l2cap_chan_del(chan, ECONNREFUSED); 5222 l2cap_chan_unlock(chan); 5223 chan = __l2cap_get_chan_by_dcid(conn, dcid); 5224 l2cap_chan_lock(chan); 5225 l2cap_chan_del(chan, ECONNRESET); 5226 l2cap_chan_unlock(chan); 5227 continue; 5228 } 5229 5230 switch (result) { 5231 case L2CAP_CR_LE_AUTHENTICATION: 5232 case L2CAP_CR_LE_ENCRYPTION: 5233 /* If we already have MITM protection we can't do 5234 * anything. 5235 */ 5236 if (hcon->sec_level > BT_SECURITY_MEDIUM) { 5237 l2cap_chan_del(chan, ECONNREFUSED); 5238 break; 5239 } 5240 5241 sec_level = hcon->sec_level + 1; 5242 if (chan->sec_level < sec_level) 5243 chan->sec_level = sec_level; 5244 5245 /* We'll need to send a new Connect Request */ 5246 clear_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags); 5247 5248 smp_conn_security(hcon, chan->sec_level); 5249 break; 5250 5251 case L2CAP_CR_LE_BAD_PSM: 5252 l2cap_chan_del(chan, ECONNREFUSED); 5253 break; 5254 5255 default: 5256 /* If dcid was not set it means channels was refused */ 5257 if (!dcid) { 5258 l2cap_chan_del(chan, ECONNREFUSED); 5259 break; 5260 } 5261 5262 chan->ident = 0; 5263 chan->dcid = dcid; 5264 chan->omtu = mtu; 5265 chan->remote_mps = mps; 5266 chan->tx_credits = credits; 5267 l2cap_chan_ready(chan); 5268 break; 5269 } 5270 5271 l2cap_chan_unlock(chan); 5272 } 5273 5274 mutex_unlock(&conn->chan_lock); 5275 5276 return err; 5277 } 5278 5279 static inline int l2cap_ecred_reconf_req(struct l2cap_conn *conn, 5280 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 5281 u8 *data) 5282 { 5283 struct l2cap_ecred_reconf_req *req = (void *) data; 5284 struct l2cap_ecred_reconf_rsp rsp; 5285 u16 mtu, mps, result; 5286 struct l2cap_chan *chan; 5287 int i, num_scid; 5288 5289 if (!enable_ecred) 5290 return -EINVAL; 5291 5292 if (cmd_len < sizeof(*req) || cmd_len - sizeof(*req) % sizeof(u16)) { 5293 result = L2CAP_CR_LE_INVALID_PARAMS; 5294 goto respond; 5295 } 5296 5297 mtu = __le16_to_cpu(req->mtu); 5298 mps = __le16_to_cpu(req->mps); 5299 5300 BT_DBG("mtu %u mps %u", mtu, mps); 5301 5302 if (mtu < L2CAP_ECRED_MIN_MTU) { 5303 result = L2CAP_RECONF_INVALID_MTU; 5304 goto respond; 5305 } 5306 5307 if (mps < L2CAP_ECRED_MIN_MPS) { 5308 result = L2CAP_RECONF_INVALID_MPS; 5309 goto respond; 5310 } 5311 5312 cmd_len -= sizeof(*req); 5313 num_scid = cmd_len / sizeof(u16); 5314 result = L2CAP_RECONF_SUCCESS; 5315 5316 for (i = 0; i < num_scid; i++) { 5317 u16 scid; 5318 5319 scid = __le16_to_cpu(req->scid[i]); 5320 if (!scid) 5321 return -EPROTO; 5322 5323 chan = __l2cap_get_chan_by_dcid(conn, scid); 5324 if (!chan) 5325 continue; 5326 5327 /* If the MTU value is decreased for any of the included 5328 * channels, then the receiver shall disconnect all 5329 * included channels. 5330 */ 5331 if (chan->omtu > mtu) { 5332 BT_ERR("chan %p decreased MTU %u -> %u", chan, 5333 chan->omtu, mtu); 5334 result = L2CAP_RECONF_INVALID_MTU; 5335 } 5336 5337 chan->omtu = mtu; 5338 chan->remote_mps = mps; 5339 } 5340 5341 respond: 5342 rsp.result = cpu_to_le16(result); 5343 5344 l2cap_send_cmd(conn, cmd->ident, L2CAP_ECRED_RECONF_RSP, sizeof(rsp), 5345 &rsp); 5346 5347 return 0; 5348 } 5349 5350 static inline int l2cap_ecred_reconf_rsp(struct l2cap_conn *conn, 5351 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 5352 u8 *data) 5353 { 5354 struct l2cap_chan *chan, *tmp; 5355 struct l2cap_ecred_conn_rsp *rsp = (void *) data; 5356 u16 result; 5357 5358 if (cmd_len < sizeof(*rsp)) 5359 return -EPROTO; 5360 5361 result = __le16_to_cpu(rsp->result); 5362 5363 BT_DBG("result 0x%4.4x", rsp->result); 5364 5365 if (!result) 5366 return 0; 5367 5368 list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) { 5369 if (chan->ident != cmd->ident) 5370 continue; 5371 5372 l2cap_chan_del(chan, ECONNRESET); 5373 } 5374 5375 return 0; 5376 } 5377 5378 static inline int l2cap_le_command_rej(struct l2cap_conn *conn, 5379 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 5380 u8 *data) 5381 { 5382 struct l2cap_cmd_rej_unk *rej = (struct l2cap_cmd_rej_unk *) data; 5383 struct l2cap_chan *chan; 5384 5385 if (cmd_len < sizeof(*rej)) 5386 return -EPROTO; 5387 5388 mutex_lock(&conn->chan_lock); 5389 5390 chan = __l2cap_get_chan_by_ident(conn, cmd->ident); 5391 if (!chan) 5392 goto done; 5393 5394 chan = l2cap_chan_hold_unless_zero(chan); 5395 if (!chan) 5396 goto done; 5397 5398 l2cap_chan_lock(chan); 5399 l2cap_chan_del(chan, ECONNREFUSED); 5400 l2cap_chan_unlock(chan); 5401 l2cap_chan_put(chan); 5402 5403 done: 5404 mutex_unlock(&conn->chan_lock); 5405 return 0; 5406 } 5407 5408 static inline int l2cap_le_sig_cmd(struct l2cap_conn *conn, 5409 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 5410 u8 *data) 5411 { 5412 int err = 0; 5413 5414 switch (cmd->code) { 5415 case L2CAP_COMMAND_REJ: 5416 l2cap_le_command_rej(conn, cmd, cmd_len, data); 5417 break; 5418 5419 case L2CAP_CONN_PARAM_UPDATE_REQ: 5420 err = l2cap_conn_param_update_req(conn, cmd, cmd_len, data); 5421 break; 5422 5423 case L2CAP_CONN_PARAM_UPDATE_RSP: 5424 break; 5425 5426 case L2CAP_LE_CONN_RSP: 5427 l2cap_le_connect_rsp(conn, cmd, cmd_len, data); 5428 break; 5429 5430 case L2CAP_LE_CONN_REQ: 5431 err = l2cap_le_connect_req(conn, cmd, cmd_len, data); 5432 break; 5433 5434 case L2CAP_LE_CREDITS: 5435 err = l2cap_le_credits(conn, cmd, cmd_len, data); 5436 break; 5437 5438 case L2CAP_ECRED_CONN_REQ: 5439 err = l2cap_ecred_conn_req(conn, cmd, cmd_len, data); 5440 break; 5441 5442 case L2CAP_ECRED_CONN_RSP: 5443 err = l2cap_ecred_conn_rsp(conn, cmd, cmd_len, data); 5444 break; 5445 5446 case L2CAP_ECRED_RECONF_REQ: 5447 err = l2cap_ecred_reconf_req(conn, cmd, cmd_len, data); 5448 break; 5449 5450 case L2CAP_ECRED_RECONF_RSP: 5451 err = l2cap_ecred_reconf_rsp(conn, cmd, cmd_len, data); 5452 break; 5453 5454 case L2CAP_DISCONN_REQ: 5455 err = l2cap_disconnect_req(conn, cmd, cmd_len, data); 5456 break; 5457 5458 case L2CAP_DISCONN_RSP: 5459 l2cap_disconnect_rsp(conn, cmd, cmd_len, data); 5460 break; 5461 5462 default: 5463 BT_ERR("Unknown LE signaling command 0x%2.2x", cmd->code); 5464 err = -EINVAL; 5465 break; 5466 } 5467 5468 return err; 5469 } 5470 5471 static inline void l2cap_le_sig_channel(struct l2cap_conn *conn, 5472 struct sk_buff *skb) 5473 { 5474 struct hci_conn *hcon = conn->hcon; 5475 struct l2cap_cmd_hdr *cmd; 5476 u16 len; 5477 int err; 5478 5479 if (hcon->type != LE_LINK) 5480 goto drop; 5481 5482 if (skb->len < L2CAP_CMD_HDR_SIZE) 5483 goto drop; 5484 5485 cmd = (void *) skb->data; 5486 skb_pull(skb, L2CAP_CMD_HDR_SIZE); 5487 5488 len = le16_to_cpu(cmd->len); 5489 5490 BT_DBG("code 0x%2.2x len %d id 0x%2.2x", cmd->code, len, cmd->ident); 5491 5492 if (len != skb->len || !cmd->ident) { 5493 BT_DBG("corrupted command"); 5494 goto drop; 5495 } 5496 5497 err = l2cap_le_sig_cmd(conn, cmd, len, skb->data); 5498 if (err) { 5499 struct l2cap_cmd_rej_unk rej; 5500 5501 BT_ERR("Wrong link type (%d)", err); 5502 5503 rej.reason = cpu_to_le16(L2CAP_REJ_NOT_UNDERSTOOD); 5504 l2cap_send_cmd(conn, cmd->ident, L2CAP_COMMAND_REJ, 5505 sizeof(rej), &rej); 5506 } 5507 5508 drop: 5509 kfree_skb(skb); 5510 } 5511 5512 static inline void l2cap_sig_send_rej(struct l2cap_conn *conn, u16 ident) 5513 { 5514 struct l2cap_cmd_rej_unk rej; 5515 5516 rej.reason = cpu_to_le16(L2CAP_REJ_NOT_UNDERSTOOD); 5517 l2cap_send_cmd(conn, ident, L2CAP_COMMAND_REJ, sizeof(rej), &rej); 5518 } 5519 5520 static inline void l2cap_sig_channel(struct l2cap_conn *conn, 5521 struct sk_buff *skb) 5522 { 5523 struct hci_conn *hcon = conn->hcon; 5524 struct l2cap_cmd_hdr *cmd; 5525 int err; 5526 5527 l2cap_raw_recv(conn, skb); 5528 5529 if (hcon->type != ACL_LINK) 5530 goto drop; 5531 5532 while (skb->len >= L2CAP_CMD_HDR_SIZE) { 5533 u16 len; 5534 5535 cmd = (void *) skb->data; 5536 skb_pull(skb, L2CAP_CMD_HDR_SIZE); 5537 5538 len = le16_to_cpu(cmd->len); 5539 5540 BT_DBG("code 0x%2.2x len %d id 0x%2.2x", cmd->code, len, 5541 cmd->ident); 5542 5543 if (len > skb->len || !cmd->ident) { 5544 BT_DBG("corrupted command"); 5545 l2cap_sig_send_rej(conn, cmd->ident); 5546 skb_pull(skb, len > skb->len ? skb->len : len); 5547 continue; 5548 } 5549 5550 err = l2cap_bredr_sig_cmd(conn, cmd, len, skb->data); 5551 if (err) { 5552 BT_ERR("Wrong link type (%d)", err); 5553 l2cap_sig_send_rej(conn, cmd->ident); 5554 } 5555 5556 skb_pull(skb, len); 5557 } 5558 5559 if (skb->len > 0) { 5560 BT_DBG("corrupted command"); 5561 l2cap_sig_send_rej(conn, 0); 5562 } 5563 5564 drop: 5565 kfree_skb(skb); 5566 } 5567 5568 static int l2cap_check_fcs(struct l2cap_chan *chan, struct sk_buff *skb) 5569 { 5570 u16 our_fcs, rcv_fcs; 5571 int hdr_size; 5572 5573 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) 5574 hdr_size = L2CAP_EXT_HDR_SIZE; 5575 else 5576 hdr_size = L2CAP_ENH_HDR_SIZE; 5577 5578 if (chan->fcs == L2CAP_FCS_CRC16) { 5579 skb_trim(skb, skb->len - L2CAP_FCS_SIZE); 5580 rcv_fcs = get_unaligned_le16(skb->data + skb->len); 5581 our_fcs = crc16(0, skb->data - hdr_size, skb->len + hdr_size); 5582 5583 if (our_fcs != rcv_fcs) 5584 return -EBADMSG; 5585 } 5586 return 0; 5587 } 5588 5589 static void l2cap_send_i_or_rr_or_rnr(struct l2cap_chan *chan) 5590 { 5591 struct l2cap_ctrl control; 5592 5593 BT_DBG("chan %p", chan); 5594 5595 memset(&control, 0, sizeof(control)); 5596 control.sframe = 1; 5597 control.final = 1; 5598 control.reqseq = chan->buffer_seq; 5599 set_bit(CONN_SEND_FBIT, &chan->conn_state); 5600 5601 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) { 5602 control.super = L2CAP_SUPER_RNR; 5603 l2cap_send_sframe(chan, &control); 5604 } 5605 5606 if (test_and_clear_bit(CONN_REMOTE_BUSY, &chan->conn_state) && 5607 chan->unacked_frames > 0) 5608 __set_retrans_timer(chan); 5609 5610 /* Send pending iframes */ 5611 l2cap_ertm_send(chan); 5612 5613 if (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state) && 5614 test_bit(CONN_SEND_FBIT, &chan->conn_state)) { 5615 /* F-bit wasn't sent in an s-frame or i-frame yet, so 5616 * send it now. 5617 */ 5618 control.super = L2CAP_SUPER_RR; 5619 l2cap_send_sframe(chan, &control); 5620 } 5621 } 5622 5623 static void append_skb_frag(struct sk_buff *skb, struct sk_buff *new_frag, 5624 struct sk_buff **last_frag) 5625 { 5626 /* skb->len reflects data in skb as well as all fragments 5627 * skb->data_len reflects only data in fragments 5628 */ 5629 if (!skb_has_frag_list(skb)) 5630 skb_shinfo(skb)->frag_list = new_frag; 5631 5632 new_frag->next = NULL; 5633 5634 (*last_frag)->next = new_frag; 5635 *last_frag = new_frag; 5636 5637 skb->len += new_frag->len; 5638 skb->data_len += new_frag->len; 5639 skb->truesize += new_frag->truesize; 5640 } 5641 5642 static int l2cap_reassemble_sdu(struct l2cap_chan *chan, struct sk_buff *skb, 5643 struct l2cap_ctrl *control) 5644 { 5645 int err = -EINVAL; 5646 5647 switch (control->sar) { 5648 case L2CAP_SAR_UNSEGMENTED: 5649 if (chan->sdu) 5650 break; 5651 5652 err = chan->ops->recv(chan, skb); 5653 break; 5654 5655 case L2CAP_SAR_START: 5656 if (chan->sdu) 5657 break; 5658 5659 if (!pskb_may_pull(skb, L2CAP_SDULEN_SIZE)) 5660 break; 5661 5662 chan->sdu_len = get_unaligned_le16(skb->data); 5663 skb_pull(skb, L2CAP_SDULEN_SIZE); 5664 5665 if (chan->sdu_len > chan->imtu) { 5666 err = -EMSGSIZE; 5667 break; 5668 } 5669 5670 if (skb->len >= chan->sdu_len) 5671 break; 5672 5673 chan->sdu = skb; 5674 chan->sdu_last_frag = skb; 5675 5676 skb = NULL; 5677 err = 0; 5678 break; 5679 5680 case L2CAP_SAR_CONTINUE: 5681 if (!chan->sdu) 5682 break; 5683 5684 append_skb_frag(chan->sdu, skb, 5685 &chan->sdu_last_frag); 5686 skb = NULL; 5687 5688 if (chan->sdu->len >= chan->sdu_len) 5689 break; 5690 5691 err = 0; 5692 break; 5693 5694 case L2CAP_SAR_END: 5695 if (!chan->sdu) 5696 break; 5697 5698 append_skb_frag(chan->sdu, skb, 5699 &chan->sdu_last_frag); 5700 skb = NULL; 5701 5702 if (chan->sdu->len != chan->sdu_len) 5703 break; 5704 5705 err = chan->ops->recv(chan, chan->sdu); 5706 5707 if (!err) { 5708 /* Reassembly complete */ 5709 chan->sdu = NULL; 5710 chan->sdu_last_frag = NULL; 5711 chan->sdu_len = 0; 5712 } 5713 break; 5714 } 5715 5716 if (err) { 5717 kfree_skb(skb); 5718 kfree_skb(chan->sdu); 5719 chan->sdu = NULL; 5720 chan->sdu_last_frag = NULL; 5721 chan->sdu_len = 0; 5722 } 5723 5724 return err; 5725 } 5726 5727 static int l2cap_resegment(struct l2cap_chan *chan) 5728 { 5729 /* Placeholder */ 5730 return 0; 5731 } 5732 5733 void l2cap_chan_busy(struct l2cap_chan *chan, int busy) 5734 { 5735 u8 event; 5736 5737 if (chan->mode != L2CAP_MODE_ERTM) 5738 return; 5739 5740 event = busy ? L2CAP_EV_LOCAL_BUSY_DETECTED : L2CAP_EV_LOCAL_BUSY_CLEAR; 5741 l2cap_tx(chan, NULL, NULL, event); 5742 } 5743 5744 static int l2cap_rx_queued_iframes(struct l2cap_chan *chan) 5745 { 5746 int err = 0; 5747 /* Pass sequential frames to l2cap_reassemble_sdu() 5748 * until a gap is encountered. 5749 */ 5750 5751 BT_DBG("chan %p", chan); 5752 5753 while (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) { 5754 struct sk_buff *skb; 5755 BT_DBG("Searching for skb with txseq %d (queue len %d)", 5756 chan->buffer_seq, skb_queue_len(&chan->srej_q)); 5757 5758 skb = l2cap_ertm_seq_in_queue(&chan->srej_q, chan->buffer_seq); 5759 5760 if (!skb) 5761 break; 5762 5763 skb_unlink(skb, &chan->srej_q); 5764 chan->buffer_seq = __next_seq(chan, chan->buffer_seq); 5765 err = l2cap_reassemble_sdu(chan, skb, &bt_cb(skb)->l2cap); 5766 if (err) 5767 break; 5768 } 5769 5770 if (skb_queue_empty(&chan->srej_q)) { 5771 chan->rx_state = L2CAP_RX_STATE_RECV; 5772 l2cap_send_ack(chan); 5773 } 5774 5775 return err; 5776 } 5777 5778 static void l2cap_handle_srej(struct l2cap_chan *chan, 5779 struct l2cap_ctrl *control) 5780 { 5781 struct sk_buff *skb; 5782 5783 BT_DBG("chan %p, control %p", chan, control); 5784 5785 if (control->reqseq == chan->next_tx_seq) { 5786 BT_DBG("Invalid reqseq %d, disconnecting", control->reqseq); 5787 l2cap_send_disconn_req(chan, ECONNRESET); 5788 return; 5789 } 5790 5791 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, control->reqseq); 5792 5793 if (skb == NULL) { 5794 BT_DBG("Seq %d not available for retransmission", 5795 control->reqseq); 5796 return; 5797 } 5798 5799 if (chan->max_tx != 0 && bt_cb(skb)->l2cap.retries >= chan->max_tx) { 5800 BT_DBG("Retry limit exceeded (%d)", chan->max_tx); 5801 l2cap_send_disconn_req(chan, ECONNRESET); 5802 return; 5803 } 5804 5805 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state); 5806 5807 if (control->poll) { 5808 l2cap_pass_to_tx(chan, control); 5809 5810 set_bit(CONN_SEND_FBIT, &chan->conn_state); 5811 l2cap_retransmit(chan, control); 5812 l2cap_ertm_send(chan); 5813 5814 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F) { 5815 set_bit(CONN_SREJ_ACT, &chan->conn_state); 5816 chan->srej_save_reqseq = control->reqseq; 5817 } 5818 } else { 5819 l2cap_pass_to_tx_fbit(chan, control); 5820 5821 if (control->final) { 5822 if (chan->srej_save_reqseq != control->reqseq || 5823 !test_and_clear_bit(CONN_SREJ_ACT, 5824 &chan->conn_state)) 5825 l2cap_retransmit(chan, control); 5826 } else { 5827 l2cap_retransmit(chan, control); 5828 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F) { 5829 set_bit(CONN_SREJ_ACT, &chan->conn_state); 5830 chan->srej_save_reqseq = control->reqseq; 5831 } 5832 } 5833 } 5834 } 5835 5836 static void l2cap_handle_rej(struct l2cap_chan *chan, 5837 struct l2cap_ctrl *control) 5838 { 5839 struct sk_buff *skb; 5840 5841 BT_DBG("chan %p, control %p", chan, control); 5842 5843 if (control->reqseq == chan->next_tx_seq) { 5844 BT_DBG("Invalid reqseq %d, disconnecting", control->reqseq); 5845 l2cap_send_disconn_req(chan, ECONNRESET); 5846 return; 5847 } 5848 5849 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, control->reqseq); 5850 5851 if (chan->max_tx && skb && 5852 bt_cb(skb)->l2cap.retries >= chan->max_tx) { 5853 BT_DBG("Retry limit exceeded (%d)", chan->max_tx); 5854 l2cap_send_disconn_req(chan, ECONNRESET); 5855 return; 5856 } 5857 5858 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state); 5859 5860 l2cap_pass_to_tx(chan, control); 5861 5862 if (control->final) { 5863 if (!test_and_clear_bit(CONN_REJ_ACT, &chan->conn_state)) 5864 l2cap_retransmit_all(chan, control); 5865 } else { 5866 l2cap_retransmit_all(chan, control); 5867 l2cap_ertm_send(chan); 5868 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F) 5869 set_bit(CONN_REJ_ACT, &chan->conn_state); 5870 } 5871 } 5872 5873 static u8 l2cap_classify_txseq(struct l2cap_chan *chan, u16 txseq) 5874 { 5875 BT_DBG("chan %p, txseq %d", chan, txseq); 5876 5877 BT_DBG("last_acked_seq %d, expected_tx_seq %d", chan->last_acked_seq, 5878 chan->expected_tx_seq); 5879 5880 if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) { 5881 if (__seq_offset(chan, txseq, chan->last_acked_seq) >= 5882 chan->tx_win) { 5883 /* See notes below regarding "double poll" and 5884 * invalid packets. 5885 */ 5886 if (chan->tx_win <= ((chan->tx_win_max + 1) >> 1)) { 5887 BT_DBG("Invalid/Ignore - after SREJ"); 5888 return L2CAP_TXSEQ_INVALID_IGNORE; 5889 } else { 5890 BT_DBG("Invalid - in window after SREJ sent"); 5891 return L2CAP_TXSEQ_INVALID; 5892 } 5893 } 5894 5895 if (chan->srej_list.head == txseq) { 5896 BT_DBG("Expected SREJ"); 5897 return L2CAP_TXSEQ_EXPECTED_SREJ; 5898 } 5899 5900 if (l2cap_ertm_seq_in_queue(&chan->srej_q, txseq)) { 5901 BT_DBG("Duplicate SREJ - txseq already stored"); 5902 return L2CAP_TXSEQ_DUPLICATE_SREJ; 5903 } 5904 5905 if (l2cap_seq_list_contains(&chan->srej_list, txseq)) { 5906 BT_DBG("Unexpected SREJ - not requested"); 5907 return L2CAP_TXSEQ_UNEXPECTED_SREJ; 5908 } 5909 } 5910 5911 if (chan->expected_tx_seq == txseq) { 5912 if (__seq_offset(chan, txseq, chan->last_acked_seq) >= 5913 chan->tx_win) { 5914 BT_DBG("Invalid - txseq outside tx window"); 5915 return L2CAP_TXSEQ_INVALID; 5916 } else { 5917 BT_DBG("Expected"); 5918 return L2CAP_TXSEQ_EXPECTED; 5919 } 5920 } 5921 5922 if (__seq_offset(chan, txseq, chan->last_acked_seq) < 5923 __seq_offset(chan, chan->expected_tx_seq, chan->last_acked_seq)) { 5924 BT_DBG("Duplicate - expected_tx_seq later than txseq"); 5925 return L2CAP_TXSEQ_DUPLICATE; 5926 } 5927 5928 if (__seq_offset(chan, txseq, chan->last_acked_seq) >= chan->tx_win) { 5929 /* A source of invalid packets is a "double poll" condition, 5930 * where delays cause us to send multiple poll packets. If 5931 * the remote stack receives and processes both polls, 5932 * sequence numbers can wrap around in such a way that a 5933 * resent frame has a sequence number that looks like new data 5934 * with a sequence gap. This would trigger an erroneous SREJ 5935 * request. 5936 * 5937 * Fortunately, this is impossible with a tx window that's 5938 * less than half of the maximum sequence number, which allows 5939 * invalid frames to be safely ignored. 5940 * 5941 * With tx window sizes greater than half of the tx window 5942 * maximum, the frame is invalid and cannot be ignored. This 5943 * causes a disconnect. 5944 */ 5945 5946 if (chan->tx_win <= ((chan->tx_win_max + 1) >> 1)) { 5947 BT_DBG("Invalid/Ignore - txseq outside tx window"); 5948 return L2CAP_TXSEQ_INVALID_IGNORE; 5949 } else { 5950 BT_DBG("Invalid - txseq outside tx window"); 5951 return L2CAP_TXSEQ_INVALID; 5952 } 5953 } else { 5954 BT_DBG("Unexpected - txseq indicates missing frames"); 5955 return L2CAP_TXSEQ_UNEXPECTED; 5956 } 5957 } 5958 5959 static int l2cap_rx_state_recv(struct l2cap_chan *chan, 5960 struct l2cap_ctrl *control, 5961 struct sk_buff *skb, u8 event) 5962 { 5963 struct l2cap_ctrl local_control; 5964 int err = 0; 5965 bool skb_in_use = false; 5966 5967 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb, 5968 event); 5969 5970 switch (event) { 5971 case L2CAP_EV_RECV_IFRAME: 5972 switch (l2cap_classify_txseq(chan, control->txseq)) { 5973 case L2CAP_TXSEQ_EXPECTED: 5974 l2cap_pass_to_tx(chan, control); 5975 5976 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) { 5977 BT_DBG("Busy, discarding expected seq %d", 5978 control->txseq); 5979 break; 5980 } 5981 5982 chan->expected_tx_seq = __next_seq(chan, 5983 control->txseq); 5984 5985 chan->buffer_seq = chan->expected_tx_seq; 5986 skb_in_use = true; 5987 5988 /* l2cap_reassemble_sdu may free skb, hence invalidate 5989 * control, so make a copy in advance to use it after 5990 * l2cap_reassemble_sdu returns and to avoid the race 5991 * condition, for example: 5992 * 5993 * The current thread calls: 5994 * l2cap_reassemble_sdu 5995 * chan->ops->recv == l2cap_sock_recv_cb 5996 * __sock_queue_rcv_skb 5997 * Another thread calls: 5998 * bt_sock_recvmsg 5999 * skb_recv_datagram 6000 * skb_free_datagram 6001 * Then the current thread tries to access control, but 6002 * it was freed by skb_free_datagram. 6003 */ 6004 local_control = *control; 6005 err = l2cap_reassemble_sdu(chan, skb, control); 6006 if (err) 6007 break; 6008 6009 if (local_control.final) { 6010 if (!test_and_clear_bit(CONN_REJ_ACT, 6011 &chan->conn_state)) { 6012 local_control.final = 0; 6013 l2cap_retransmit_all(chan, &local_control); 6014 l2cap_ertm_send(chan); 6015 } 6016 } 6017 6018 if (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) 6019 l2cap_send_ack(chan); 6020 break; 6021 case L2CAP_TXSEQ_UNEXPECTED: 6022 l2cap_pass_to_tx(chan, control); 6023 6024 /* Can't issue SREJ frames in the local busy state. 6025 * Drop this frame, it will be seen as missing 6026 * when local busy is exited. 6027 */ 6028 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) { 6029 BT_DBG("Busy, discarding unexpected seq %d", 6030 control->txseq); 6031 break; 6032 } 6033 6034 /* There was a gap in the sequence, so an SREJ 6035 * must be sent for each missing frame. The 6036 * current frame is stored for later use. 6037 */ 6038 skb_queue_tail(&chan->srej_q, skb); 6039 skb_in_use = true; 6040 BT_DBG("Queued %p (queue len %d)", skb, 6041 skb_queue_len(&chan->srej_q)); 6042 6043 clear_bit(CONN_SREJ_ACT, &chan->conn_state); 6044 l2cap_seq_list_clear(&chan->srej_list); 6045 l2cap_send_srej(chan, control->txseq); 6046 6047 chan->rx_state = L2CAP_RX_STATE_SREJ_SENT; 6048 break; 6049 case L2CAP_TXSEQ_DUPLICATE: 6050 l2cap_pass_to_tx(chan, control); 6051 break; 6052 case L2CAP_TXSEQ_INVALID_IGNORE: 6053 break; 6054 case L2CAP_TXSEQ_INVALID: 6055 default: 6056 l2cap_send_disconn_req(chan, ECONNRESET); 6057 break; 6058 } 6059 break; 6060 case L2CAP_EV_RECV_RR: 6061 l2cap_pass_to_tx(chan, control); 6062 if (control->final) { 6063 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state); 6064 6065 if (!test_and_clear_bit(CONN_REJ_ACT, 6066 &chan->conn_state)) { 6067 control->final = 0; 6068 l2cap_retransmit_all(chan, control); 6069 } 6070 6071 l2cap_ertm_send(chan); 6072 } else if (control->poll) { 6073 l2cap_send_i_or_rr_or_rnr(chan); 6074 } else { 6075 if (test_and_clear_bit(CONN_REMOTE_BUSY, 6076 &chan->conn_state) && 6077 chan->unacked_frames) 6078 __set_retrans_timer(chan); 6079 6080 l2cap_ertm_send(chan); 6081 } 6082 break; 6083 case L2CAP_EV_RECV_RNR: 6084 set_bit(CONN_REMOTE_BUSY, &chan->conn_state); 6085 l2cap_pass_to_tx(chan, control); 6086 if (control && control->poll) { 6087 set_bit(CONN_SEND_FBIT, &chan->conn_state); 6088 l2cap_send_rr_or_rnr(chan, 0); 6089 } 6090 __clear_retrans_timer(chan); 6091 l2cap_seq_list_clear(&chan->retrans_list); 6092 break; 6093 case L2CAP_EV_RECV_REJ: 6094 l2cap_handle_rej(chan, control); 6095 break; 6096 case L2CAP_EV_RECV_SREJ: 6097 l2cap_handle_srej(chan, control); 6098 break; 6099 default: 6100 break; 6101 } 6102 6103 if (skb && !skb_in_use) { 6104 BT_DBG("Freeing %p", skb); 6105 kfree_skb(skb); 6106 } 6107 6108 return err; 6109 } 6110 6111 static int l2cap_rx_state_srej_sent(struct l2cap_chan *chan, 6112 struct l2cap_ctrl *control, 6113 struct sk_buff *skb, u8 event) 6114 { 6115 int err = 0; 6116 u16 txseq = control->txseq; 6117 bool skb_in_use = false; 6118 6119 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb, 6120 event); 6121 6122 switch (event) { 6123 case L2CAP_EV_RECV_IFRAME: 6124 switch (l2cap_classify_txseq(chan, txseq)) { 6125 case L2CAP_TXSEQ_EXPECTED: 6126 /* Keep frame for reassembly later */ 6127 l2cap_pass_to_tx(chan, control); 6128 skb_queue_tail(&chan->srej_q, skb); 6129 skb_in_use = true; 6130 BT_DBG("Queued %p (queue len %d)", skb, 6131 skb_queue_len(&chan->srej_q)); 6132 6133 chan->expected_tx_seq = __next_seq(chan, txseq); 6134 break; 6135 case L2CAP_TXSEQ_EXPECTED_SREJ: 6136 l2cap_seq_list_pop(&chan->srej_list); 6137 6138 l2cap_pass_to_tx(chan, control); 6139 skb_queue_tail(&chan->srej_q, skb); 6140 skb_in_use = true; 6141 BT_DBG("Queued %p (queue len %d)", skb, 6142 skb_queue_len(&chan->srej_q)); 6143 6144 err = l2cap_rx_queued_iframes(chan); 6145 if (err) 6146 break; 6147 6148 break; 6149 case L2CAP_TXSEQ_UNEXPECTED: 6150 /* Got a frame that can't be reassembled yet. 6151 * Save it for later, and send SREJs to cover 6152 * the missing frames. 6153 */ 6154 skb_queue_tail(&chan->srej_q, skb); 6155 skb_in_use = true; 6156 BT_DBG("Queued %p (queue len %d)", skb, 6157 skb_queue_len(&chan->srej_q)); 6158 6159 l2cap_pass_to_tx(chan, control); 6160 l2cap_send_srej(chan, control->txseq); 6161 break; 6162 case L2CAP_TXSEQ_UNEXPECTED_SREJ: 6163 /* This frame was requested with an SREJ, but 6164 * some expected retransmitted frames are 6165 * missing. Request retransmission of missing 6166 * SREJ'd frames. 6167 */ 6168 skb_queue_tail(&chan->srej_q, skb); 6169 skb_in_use = true; 6170 BT_DBG("Queued %p (queue len %d)", skb, 6171 skb_queue_len(&chan->srej_q)); 6172 6173 l2cap_pass_to_tx(chan, control); 6174 l2cap_send_srej_list(chan, control->txseq); 6175 break; 6176 case L2CAP_TXSEQ_DUPLICATE_SREJ: 6177 /* We've already queued this frame. Drop this copy. */ 6178 l2cap_pass_to_tx(chan, control); 6179 break; 6180 case L2CAP_TXSEQ_DUPLICATE: 6181 /* Expecting a later sequence number, so this frame 6182 * was already received. Ignore it completely. 6183 */ 6184 break; 6185 case L2CAP_TXSEQ_INVALID_IGNORE: 6186 break; 6187 case L2CAP_TXSEQ_INVALID: 6188 default: 6189 l2cap_send_disconn_req(chan, ECONNRESET); 6190 break; 6191 } 6192 break; 6193 case L2CAP_EV_RECV_RR: 6194 l2cap_pass_to_tx(chan, control); 6195 if (control->final) { 6196 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state); 6197 6198 if (!test_and_clear_bit(CONN_REJ_ACT, 6199 &chan->conn_state)) { 6200 control->final = 0; 6201 l2cap_retransmit_all(chan, control); 6202 } 6203 6204 l2cap_ertm_send(chan); 6205 } else if (control->poll) { 6206 if (test_and_clear_bit(CONN_REMOTE_BUSY, 6207 &chan->conn_state) && 6208 chan->unacked_frames) { 6209 __set_retrans_timer(chan); 6210 } 6211 6212 set_bit(CONN_SEND_FBIT, &chan->conn_state); 6213 l2cap_send_srej_tail(chan); 6214 } else { 6215 if (test_and_clear_bit(CONN_REMOTE_BUSY, 6216 &chan->conn_state) && 6217 chan->unacked_frames) 6218 __set_retrans_timer(chan); 6219 6220 l2cap_send_ack(chan); 6221 } 6222 break; 6223 case L2CAP_EV_RECV_RNR: 6224 set_bit(CONN_REMOTE_BUSY, &chan->conn_state); 6225 l2cap_pass_to_tx(chan, control); 6226 if (control->poll) { 6227 l2cap_send_srej_tail(chan); 6228 } else { 6229 struct l2cap_ctrl rr_control; 6230 memset(&rr_control, 0, sizeof(rr_control)); 6231 rr_control.sframe = 1; 6232 rr_control.super = L2CAP_SUPER_RR; 6233 rr_control.reqseq = chan->buffer_seq; 6234 l2cap_send_sframe(chan, &rr_control); 6235 } 6236 6237 break; 6238 case L2CAP_EV_RECV_REJ: 6239 l2cap_handle_rej(chan, control); 6240 break; 6241 case L2CAP_EV_RECV_SREJ: 6242 l2cap_handle_srej(chan, control); 6243 break; 6244 } 6245 6246 if (skb && !skb_in_use) { 6247 BT_DBG("Freeing %p", skb); 6248 kfree_skb(skb); 6249 } 6250 6251 return err; 6252 } 6253 6254 static int l2cap_finish_move(struct l2cap_chan *chan) 6255 { 6256 BT_DBG("chan %p", chan); 6257 6258 chan->rx_state = L2CAP_RX_STATE_RECV; 6259 chan->conn->mtu = chan->conn->hcon->mtu; 6260 6261 return l2cap_resegment(chan); 6262 } 6263 6264 static int l2cap_rx_state_wait_p(struct l2cap_chan *chan, 6265 struct l2cap_ctrl *control, 6266 struct sk_buff *skb, u8 event) 6267 { 6268 int err; 6269 6270 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb, 6271 event); 6272 6273 if (!control->poll) 6274 return -EPROTO; 6275 6276 l2cap_process_reqseq(chan, control->reqseq); 6277 6278 if (!skb_queue_empty(&chan->tx_q)) 6279 chan->tx_send_head = skb_peek(&chan->tx_q); 6280 else 6281 chan->tx_send_head = NULL; 6282 6283 /* Rewind next_tx_seq to the point expected 6284 * by the receiver. 6285 */ 6286 chan->next_tx_seq = control->reqseq; 6287 chan->unacked_frames = 0; 6288 6289 err = l2cap_finish_move(chan); 6290 if (err) 6291 return err; 6292 6293 set_bit(CONN_SEND_FBIT, &chan->conn_state); 6294 l2cap_send_i_or_rr_or_rnr(chan); 6295 6296 if (event == L2CAP_EV_RECV_IFRAME) 6297 return -EPROTO; 6298 6299 return l2cap_rx_state_recv(chan, control, NULL, event); 6300 } 6301 6302 static int l2cap_rx_state_wait_f(struct l2cap_chan *chan, 6303 struct l2cap_ctrl *control, 6304 struct sk_buff *skb, u8 event) 6305 { 6306 int err; 6307 6308 if (!control->final) 6309 return -EPROTO; 6310 6311 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state); 6312 6313 chan->rx_state = L2CAP_RX_STATE_RECV; 6314 l2cap_process_reqseq(chan, control->reqseq); 6315 6316 if (!skb_queue_empty(&chan->tx_q)) 6317 chan->tx_send_head = skb_peek(&chan->tx_q); 6318 else 6319 chan->tx_send_head = NULL; 6320 6321 /* Rewind next_tx_seq to the point expected 6322 * by the receiver. 6323 */ 6324 chan->next_tx_seq = control->reqseq; 6325 chan->unacked_frames = 0; 6326 chan->conn->mtu = chan->conn->hcon->mtu; 6327 6328 err = l2cap_resegment(chan); 6329 6330 if (!err) 6331 err = l2cap_rx_state_recv(chan, control, skb, event); 6332 6333 return err; 6334 } 6335 6336 static bool __valid_reqseq(struct l2cap_chan *chan, u16 reqseq) 6337 { 6338 /* Make sure reqseq is for a packet that has been sent but not acked */ 6339 u16 unacked; 6340 6341 unacked = __seq_offset(chan, chan->next_tx_seq, chan->expected_ack_seq); 6342 return __seq_offset(chan, chan->next_tx_seq, reqseq) <= unacked; 6343 } 6344 6345 static int l2cap_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control, 6346 struct sk_buff *skb, u8 event) 6347 { 6348 int err = 0; 6349 6350 BT_DBG("chan %p, control %p, skb %p, event %d, state %d", chan, 6351 control, skb, event, chan->rx_state); 6352 6353 if (__valid_reqseq(chan, control->reqseq)) { 6354 switch (chan->rx_state) { 6355 case L2CAP_RX_STATE_RECV: 6356 err = l2cap_rx_state_recv(chan, control, skb, event); 6357 break; 6358 case L2CAP_RX_STATE_SREJ_SENT: 6359 err = l2cap_rx_state_srej_sent(chan, control, skb, 6360 event); 6361 break; 6362 case L2CAP_RX_STATE_WAIT_P: 6363 err = l2cap_rx_state_wait_p(chan, control, skb, event); 6364 break; 6365 case L2CAP_RX_STATE_WAIT_F: 6366 err = l2cap_rx_state_wait_f(chan, control, skb, event); 6367 break; 6368 default: 6369 /* shut it down */ 6370 break; 6371 } 6372 } else { 6373 BT_DBG("Invalid reqseq %d (next_tx_seq %d, expected_ack_seq %d", 6374 control->reqseq, chan->next_tx_seq, 6375 chan->expected_ack_seq); 6376 l2cap_send_disconn_req(chan, ECONNRESET); 6377 } 6378 6379 return err; 6380 } 6381 6382 static int l2cap_stream_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control, 6383 struct sk_buff *skb) 6384 { 6385 /* l2cap_reassemble_sdu may free skb, hence invalidate control, so store 6386 * the txseq field in advance to use it after l2cap_reassemble_sdu 6387 * returns and to avoid the race condition, for example: 6388 * 6389 * The current thread calls: 6390 * l2cap_reassemble_sdu 6391 * chan->ops->recv == l2cap_sock_recv_cb 6392 * __sock_queue_rcv_skb 6393 * Another thread calls: 6394 * bt_sock_recvmsg 6395 * skb_recv_datagram 6396 * skb_free_datagram 6397 * Then the current thread tries to access control, but it was freed by 6398 * skb_free_datagram. 6399 */ 6400 u16 txseq = control->txseq; 6401 6402 BT_DBG("chan %p, control %p, skb %p, state %d", chan, control, skb, 6403 chan->rx_state); 6404 6405 if (l2cap_classify_txseq(chan, txseq) == L2CAP_TXSEQ_EXPECTED) { 6406 l2cap_pass_to_tx(chan, control); 6407 6408 BT_DBG("buffer_seq %u->%u", chan->buffer_seq, 6409 __next_seq(chan, chan->buffer_seq)); 6410 6411 chan->buffer_seq = __next_seq(chan, chan->buffer_seq); 6412 6413 l2cap_reassemble_sdu(chan, skb, control); 6414 } else { 6415 if (chan->sdu) { 6416 kfree_skb(chan->sdu); 6417 chan->sdu = NULL; 6418 } 6419 chan->sdu_last_frag = NULL; 6420 chan->sdu_len = 0; 6421 6422 if (skb) { 6423 BT_DBG("Freeing %p", skb); 6424 kfree_skb(skb); 6425 } 6426 } 6427 6428 chan->last_acked_seq = txseq; 6429 chan->expected_tx_seq = __next_seq(chan, txseq); 6430 6431 return 0; 6432 } 6433 6434 static int l2cap_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb) 6435 { 6436 struct l2cap_ctrl *control = &bt_cb(skb)->l2cap; 6437 u16 len; 6438 u8 event; 6439 6440 __unpack_control(chan, skb); 6441 6442 len = skb->len; 6443 6444 /* 6445 * We can just drop the corrupted I-frame here. 6446 * Receiver will miss it and start proper recovery 6447 * procedures and ask for retransmission. 6448 */ 6449 if (l2cap_check_fcs(chan, skb)) 6450 goto drop; 6451 6452 if (!control->sframe && control->sar == L2CAP_SAR_START) 6453 len -= L2CAP_SDULEN_SIZE; 6454 6455 if (chan->fcs == L2CAP_FCS_CRC16) 6456 len -= L2CAP_FCS_SIZE; 6457 6458 if (len > chan->mps) { 6459 l2cap_send_disconn_req(chan, ECONNRESET); 6460 goto drop; 6461 } 6462 6463 if (chan->ops->filter) { 6464 if (chan->ops->filter(chan, skb)) 6465 goto drop; 6466 } 6467 6468 if (!control->sframe) { 6469 int err; 6470 6471 BT_DBG("iframe sar %d, reqseq %d, final %d, txseq %d", 6472 control->sar, control->reqseq, control->final, 6473 control->txseq); 6474 6475 /* Validate F-bit - F=0 always valid, F=1 only 6476 * valid in TX WAIT_F 6477 */ 6478 if (control->final && chan->tx_state != L2CAP_TX_STATE_WAIT_F) 6479 goto drop; 6480 6481 if (chan->mode != L2CAP_MODE_STREAMING) { 6482 event = L2CAP_EV_RECV_IFRAME; 6483 err = l2cap_rx(chan, control, skb, event); 6484 } else { 6485 err = l2cap_stream_rx(chan, control, skb); 6486 } 6487 6488 if (err) 6489 l2cap_send_disconn_req(chan, ECONNRESET); 6490 } else { 6491 const u8 rx_func_to_event[4] = { 6492 L2CAP_EV_RECV_RR, L2CAP_EV_RECV_REJ, 6493 L2CAP_EV_RECV_RNR, L2CAP_EV_RECV_SREJ 6494 }; 6495 6496 /* Only I-frames are expected in streaming mode */ 6497 if (chan->mode == L2CAP_MODE_STREAMING) 6498 goto drop; 6499 6500 BT_DBG("sframe reqseq %d, final %d, poll %d, super %d", 6501 control->reqseq, control->final, control->poll, 6502 control->super); 6503 6504 if (len != 0) { 6505 BT_ERR("Trailing bytes: %d in sframe", len); 6506 l2cap_send_disconn_req(chan, ECONNRESET); 6507 goto drop; 6508 } 6509 6510 /* Validate F and P bits */ 6511 if (control->final && (control->poll || 6512 chan->tx_state != L2CAP_TX_STATE_WAIT_F)) 6513 goto drop; 6514 6515 event = rx_func_to_event[control->super]; 6516 if (l2cap_rx(chan, control, skb, event)) 6517 l2cap_send_disconn_req(chan, ECONNRESET); 6518 } 6519 6520 return 0; 6521 6522 drop: 6523 kfree_skb(skb); 6524 return 0; 6525 } 6526 6527 static void l2cap_chan_le_send_credits(struct l2cap_chan *chan) 6528 { 6529 struct l2cap_conn *conn = chan->conn; 6530 struct l2cap_le_credits pkt; 6531 u16 return_credits = l2cap_le_rx_credits(chan); 6532 6533 if (chan->rx_credits >= return_credits) 6534 return; 6535 6536 return_credits -= chan->rx_credits; 6537 6538 BT_DBG("chan %p returning %u credits to sender", chan, return_credits); 6539 6540 chan->rx_credits += return_credits; 6541 6542 pkt.cid = cpu_to_le16(chan->scid); 6543 pkt.credits = cpu_to_le16(return_credits); 6544 6545 chan->ident = l2cap_get_ident(conn); 6546 6547 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CREDITS, sizeof(pkt), &pkt); 6548 } 6549 6550 void l2cap_chan_rx_avail(struct l2cap_chan *chan, ssize_t rx_avail) 6551 { 6552 if (chan->rx_avail == rx_avail) 6553 return; 6554 6555 BT_DBG("chan %p has %zd bytes avail for rx", chan, rx_avail); 6556 6557 chan->rx_avail = rx_avail; 6558 6559 if (chan->state == BT_CONNECTED) 6560 l2cap_chan_le_send_credits(chan); 6561 } 6562 6563 static int l2cap_ecred_recv(struct l2cap_chan *chan, struct sk_buff *skb) 6564 { 6565 int err; 6566 6567 BT_DBG("SDU reassemble complete: chan %p skb->len %u", chan, skb->len); 6568 6569 /* Wait recv to confirm reception before updating the credits */ 6570 err = chan->ops->recv(chan, skb); 6571 6572 if (err < 0 && chan->rx_avail != -1) { 6573 BT_ERR("Queueing received LE L2CAP data failed"); 6574 l2cap_send_disconn_req(chan, ECONNRESET); 6575 return err; 6576 } 6577 6578 /* Update credits whenever an SDU is received */ 6579 l2cap_chan_le_send_credits(chan); 6580 6581 return err; 6582 } 6583 6584 static int l2cap_ecred_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb) 6585 { 6586 int err; 6587 6588 if (!chan->rx_credits) { 6589 BT_ERR("No credits to receive LE L2CAP data"); 6590 l2cap_send_disconn_req(chan, ECONNRESET); 6591 return -ENOBUFS; 6592 } 6593 6594 if (chan->imtu < skb->len) { 6595 BT_ERR("Too big LE L2CAP PDU"); 6596 return -ENOBUFS; 6597 } 6598 6599 chan->rx_credits--; 6600 BT_DBG("chan %p: rx_credits %u -> %u", 6601 chan, chan->rx_credits + 1, chan->rx_credits); 6602 6603 /* Update if remote had run out of credits, this should only happens 6604 * if the remote is not using the entire MPS. 6605 */ 6606 if (!chan->rx_credits) 6607 l2cap_chan_le_send_credits(chan); 6608 6609 err = 0; 6610 6611 if (!chan->sdu) { 6612 u16 sdu_len; 6613 6614 sdu_len = get_unaligned_le16(skb->data); 6615 skb_pull(skb, L2CAP_SDULEN_SIZE); 6616 6617 BT_DBG("Start of new SDU. sdu_len %u skb->len %u imtu %u", 6618 sdu_len, skb->len, chan->imtu); 6619 6620 if (sdu_len > chan->imtu) { 6621 BT_ERR("Too big LE L2CAP SDU length received"); 6622 err = -EMSGSIZE; 6623 goto failed; 6624 } 6625 6626 if (skb->len > sdu_len) { 6627 BT_ERR("Too much LE L2CAP data received"); 6628 err = -EINVAL; 6629 goto failed; 6630 } 6631 6632 if (skb->len == sdu_len) 6633 return l2cap_ecred_recv(chan, skb); 6634 6635 chan->sdu = skb; 6636 chan->sdu_len = sdu_len; 6637 chan->sdu_last_frag = skb; 6638 6639 /* Detect if remote is not able to use the selected MPS */ 6640 if (skb->len + L2CAP_SDULEN_SIZE < chan->mps) { 6641 u16 mps_len = skb->len + L2CAP_SDULEN_SIZE; 6642 6643 /* Adjust the number of credits */ 6644 BT_DBG("chan->mps %u -> %u", chan->mps, mps_len); 6645 chan->mps = mps_len; 6646 l2cap_chan_le_send_credits(chan); 6647 } 6648 6649 return 0; 6650 } 6651 6652 BT_DBG("SDU fragment. chan->sdu->len %u skb->len %u chan->sdu_len %u", 6653 chan->sdu->len, skb->len, chan->sdu_len); 6654 6655 if (chan->sdu->len + skb->len > chan->sdu_len) { 6656 BT_ERR("Too much LE L2CAP data received"); 6657 err = -EINVAL; 6658 goto failed; 6659 } 6660 6661 append_skb_frag(chan->sdu, skb, &chan->sdu_last_frag); 6662 skb = NULL; 6663 6664 if (chan->sdu->len == chan->sdu_len) { 6665 err = l2cap_ecred_recv(chan, chan->sdu); 6666 if (!err) { 6667 chan->sdu = NULL; 6668 chan->sdu_last_frag = NULL; 6669 chan->sdu_len = 0; 6670 } 6671 } 6672 6673 failed: 6674 if (err) { 6675 kfree_skb(skb); 6676 kfree_skb(chan->sdu); 6677 chan->sdu = NULL; 6678 chan->sdu_last_frag = NULL; 6679 chan->sdu_len = 0; 6680 } 6681 6682 /* We can't return an error here since we took care of the skb 6683 * freeing internally. An error return would cause the caller to 6684 * do a double-free of the skb. 6685 */ 6686 return 0; 6687 } 6688 6689 static void l2cap_data_channel(struct l2cap_conn *conn, u16 cid, 6690 struct sk_buff *skb) 6691 { 6692 struct l2cap_chan *chan; 6693 6694 chan = l2cap_get_chan_by_scid(conn, cid); 6695 if (!chan) { 6696 BT_DBG("unknown cid 0x%4.4x", cid); 6697 /* Drop packet and return */ 6698 kfree_skb(skb); 6699 return; 6700 } 6701 6702 BT_DBG("chan %p, len %d", chan, skb->len); 6703 6704 /* If we receive data on a fixed channel before the info req/rsp 6705 * procedure is done simply assume that the channel is supported 6706 * and mark it as ready. 6707 */ 6708 if (chan->chan_type == L2CAP_CHAN_FIXED) 6709 l2cap_chan_ready(chan); 6710 6711 if (chan->state != BT_CONNECTED) 6712 goto drop; 6713 6714 switch (chan->mode) { 6715 case L2CAP_MODE_LE_FLOWCTL: 6716 case L2CAP_MODE_EXT_FLOWCTL: 6717 if (l2cap_ecred_data_rcv(chan, skb) < 0) 6718 goto drop; 6719 6720 goto done; 6721 6722 case L2CAP_MODE_BASIC: 6723 /* If socket recv buffers overflows we drop data here 6724 * which is *bad* because L2CAP has to be reliable. 6725 * But we don't have any other choice. L2CAP doesn't 6726 * provide flow control mechanism. */ 6727 6728 if (chan->imtu < skb->len) { 6729 BT_ERR("Dropping L2CAP data: receive buffer overflow"); 6730 goto drop; 6731 } 6732 6733 if (!chan->ops->recv(chan, skb)) 6734 goto done; 6735 break; 6736 6737 case L2CAP_MODE_ERTM: 6738 case L2CAP_MODE_STREAMING: 6739 l2cap_data_rcv(chan, skb); 6740 goto done; 6741 6742 default: 6743 BT_DBG("chan %p: bad mode 0x%2.2x", chan, chan->mode); 6744 break; 6745 } 6746 6747 drop: 6748 kfree_skb(skb); 6749 6750 done: 6751 l2cap_chan_unlock(chan); 6752 l2cap_chan_put(chan); 6753 } 6754 6755 static void l2cap_conless_channel(struct l2cap_conn *conn, __le16 psm, 6756 struct sk_buff *skb) 6757 { 6758 struct hci_conn *hcon = conn->hcon; 6759 struct l2cap_chan *chan; 6760 6761 if (hcon->type != ACL_LINK) 6762 goto free_skb; 6763 6764 chan = l2cap_global_chan_by_psm(0, psm, &hcon->src, &hcon->dst, 6765 ACL_LINK); 6766 if (!chan) 6767 goto free_skb; 6768 6769 BT_DBG("chan %p, len %d", chan, skb->len); 6770 6771 if (chan->state != BT_BOUND && chan->state != BT_CONNECTED) 6772 goto drop; 6773 6774 if (chan->imtu < skb->len) 6775 goto drop; 6776 6777 /* Store remote BD_ADDR and PSM for msg_name */ 6778 bacpy(&bt_cb(skb)->l2cap.bdaddr, &hcon->dst); 6779 bt_cb(skb)->l2cap.psm = psm; 6780 6781 if (!chan->ops->recv(chan, skb)) { 6782 l2cap_chan_put(chan); 6783 return; 6784 } 6785 6786 drop: 6787 l2cap_chan_put(chan); 6788 free_skb: 6789 kfree_skb(skb); 6790 } 6791 6792 static void l2cap_recv_frame(struct l2cap_conn *conn, struct sk_buff *skb) 6793 { 6794 struct l2cap_hdr *lh = (void *) skb->data; 6795 struct hci_conn *hcon = conn->hcon; 6796 u16 cid, len; 6797 __le16 psm; 6798 6799 if (hcon->state != BT_CONNECTED) { 6800 BT_DBG("queueing pending rx skb"); 6801 skb_queue_tail(&conn->pending_rx, skb); 6802 return; 6803 } 6804 6805 skb_pull(skb, L2CAP_HDR_SIZE); 6806 cid = __le16_to_cpu(lh->cid); 6807 len = __le16_to_cpu(lh->len); 6808 6809 if (len != skb->len) { 6810 kfree_skb(skb); 6811 return; 6812 } 6813 6814 /* Since we can't actively block incoming LE connections we must 6815 * at least ensure that we ignore incoming data from them. 6816 */ 6817 if (hcon->type == LE_LINK && 6818 hci_bdaddr_list_lookup(&hcon->hdev->reject_list, &hcon->dst, 6819 bdaddr_dst_type(hcon))) { 6820 kfree_skb(skb); 6821 return; 6822 } 6823 6824 BT_DBG("len %d, cid 0x%4.4x", len, cid); 6825 6826 switch (cid) { 6827 case L2CAP_CID_SIGNALING: 6828 l2cap_sig_channel(conn, skb); 6829 break; 6830 6831 case L2CAP_CID_CONN_LESS: 6832 psm = get_unaligned((__le16 *) skb->data); 6833 skb_pull(skb, L2CAP_PSMLEN_SIZE); 6834 l2cap_conless_channel(conn, psm, skb); 6835 break; 6836 6837 case L2CAP_CID_LE_SIGNALING: 6838 l2cap_le_sig_channel(conn, skb); 6839 break; 6840 6841 default: 6842 l2cap_data_channel(conn, cid, skb); 6843 break; 6844 } 6845 } 6846 6847 static void process_pending_rx(struct work_struct *work) 6848 { 6849 struct l2cap_conn *conn = container_of(work, struct l2cap_conn, 6850 pending_rx_work); 6851 struct sk_buff *skb; 6852 6853 BT_DBG(""); 6854 6855 while ((skb = skb_dequeue(&conn->pending_rx))) 6856 l2cap_recv_frame(conn, skb); 6857 } 6858 6859 static struct l2cap_conn *l2cap_conn_add(struct hci_conn *hcon) 6860 { 6861 struct l2cap_conn *conn = hcon->l2cap_data; 6862 struct hci_chan *hchan; 6863 6864 if (conn) 6865 return conn; 6866 6867 hchan = hci_chan_create(hcon); 6868 if (!hchan) 6869 return NULL; 6870 6871 conn = kzalloc(sizeof(*conn), GFP_KERNEL); 6872 if (!conn) { 6873 hci_chan_del(hchan); 6874 return NULL; 6875 } 6876 6877 kref_init(&conn->ref); 6878 hcon->l2cap_data = conn; 6879 conn->hcon = hci_conn_get(hcon); 6880 conn->hchan = hchan; 6881 6882 BT_DBG("hcon %p conn %p hchan %p", hcon, conn, hchan); 6883 6884 conn->mtu = hcon->mtu; 6885 conn->feat_mask = 0; 6886 6887 conn->local_fixed_chan = L2CAP_FC_SIG_BREDR | L2CAP_FC_CONNLESS; 6888 6889 if (hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED) && 6890 (bredr_sc_enabled(hcon->hdev) || 6891 hci_dev_test_flag(hcon->hdev, HCI_FORCE_BREDR_SMP))) 6892 conn->local_fixed_chan |= L2CAP_FC_SMP_BREDR; 6893 6894 mutex_init(&conn->ident_lock); 6895 mutex_init(&conn->chan_lock); 6896 6897 INIT_LIST_HEAD(&conn->chan_l); 6898 INIT_LIST_HEAD(&conn->users); 6899 6900 INIT_DELAYED_WORK(&conn->info_timer, l2cap_info_timeout); 6901 6902 skb_queue_head_init(&conn->pending_rx); 6903 INIT_WORK(&conn->pending_rx_work, process_pending_rx); 6904 INIT_DELAYED_WORK(&conn->id_addr_timer, l2cap_conn_update_id_addr); 6905 6906 conn->disc_reason = HCI_ERROR_REMOTE_USER_TERM; 6907 6908 return conn; 6909 } 6910 6911 static bool is_valid_psm(u16 psm, u8 dst_type) 6912 { 6913 if (!psm) 6914 return false; 6915 6916 if (bdaddr_type_is_le(dst_type)) 6917 return (psm <= 0x00ff); 6918 6919 /* PSM must be odd and lsb of upper byte must be 0 */ 6920 return ((psm & 0x0101) == 0x0001); 6921 } 6922 6923 struct l2cap_chan_data { 6924 struct l2cap_chan *chan; 6925 struct pid *pid; 6926 int count; 6927 }; 6928 6929 static void l2cap_chan_by_pid(struct l2cap_chan *chan, void *data) 6930 { 6931 struct l2cap_chan_data *d = data; 6932 struct pid *pid; 6933 6934 if (chan == d->chan) 6935 return; 6936 6937 if (!test_bit(FLAG_DEFER_SETUP, &chan->flags)) 6938 return; 6939 6940 pid = chan->ops->get_peer_pid(chan); 6941 6942 /* Only count deferred channels with the same PID/PSM */ 6943 if (d->pid != pid || chan->psm != d->chan->psm || chan->ident || 6944 chan->mode != L2CAP_MODE_EXT_FLOWCTL || chan->state != BT_CONNECT) 6945 return; 6946 6947 d->count++; 6948 } 6949 6950 int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid, 6951 bdaddr_t *dst, u8 dst_type) 6952 { 6953 struct l2cap_conn *conn; 6954 struct hci_conn *hcon; 6955 struct hci_dev *hdev; 6956 int err; 6957 6958 BT_DBG("%pMR -> %pMR (type %u) psm 0x%4.4x mode 0x%2.2x", &chan->src, 6959 dst, dst_type, __le16_to_cpu(psm), chan->mode); 6960 6961 hdev = hci_get_route(dst, &chan->src, chan->src_type); 6962 if (!hdev) 6963 return -EHOSTUNREACH; 6964 6965 hci_dev_lock(hdev); 6966 6967 if (!is_valid_psm(__le16_to_cpu(psm), dst_type) && !cid && 6968 chan->chan_type != L2CAP_CHAN_RAW) { 6969 err = -EINVAL; 6970 goto done; 6971 } 6972 6973 if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED && !psm) { 6974 err = -EINVAL; 6975 goto done; 6976 } 6977 6978 if (chan->chan_type == L2CAP_CHAN_FIXED && !cid) { 6979 err = -EINVAL; 6980 goto done; 6981 } 6982 6983 switch (chan->mode) { 6984 case L2CAP_MODE_BASIC: 6985 break; 6986 case L2CAP_MODE_LE_FLOWCTL: 6987 break; 6988 case L2CAP_MODE_EXT_FLOWCTL: 6989 if (!enable_ecred) { 6990 err = -EOPNOTSUPP; 6991 goto done; 6992 } 6993 break; 6994 case L2CAP_MODE_ERTM: 6995 case L2CAP_MODE_STREAMING: 6996 if (!disable_ertm) 6997 break; 6998 fallthrough; 6999 default: 7000 err = -EOPNOTSUPP; 7001 goto done; 7002 } 7003 7004 switch (chan->state) { 7005 case BT_CONNECT: 7006 case BT_CONNECT2: 7007 case BT_CONFIG: 7008 /* Already connecting */ 7009 err = 0; 7010 goto done; 7011 7012 case BT_CONNECTED: 7013 /* Already connected */ 7014 err = -EISCONN; 7015 goto done; 7016 7017 case BT_OPEN: 7018 case BT_BOUND: 7019 /* Can connect */ 7020 break; 7021 7022 default: 7023 err = -EBADFD; 7024 goto done; 7025 } 7026 7027 /* Set destination address and psm */ 7028 bacpy(&chan->dst, dst); 7029 chan->dst_type = dst_type; 7030 7031 chan->psm = psm; 7032 chan->dcid = cid; 7033 7034 if (bdaddr_type_is_le(dst_type)) { 7035 /* Convert from L2CAP channel address type to HCI address type 7036 */ 7037 if (dst_type == BDADDR_LE_PUBLIC) 7038 dst_type = ADDR_LE_DEV_PUBLIC; 7039 else 7040 dst_type = ADDR_LE_DEV_RANDOM; 7041 7042 if (hci_dev_test_flag(hdev, HCI_ADVERTISING)) 7043 hcon = hci_connect_le(hdev, dst, dst_type, false, 7044 chan->sec_level, 7045 HCI_LE_CONN_TIMEOUT, 7046 HCI_ROLE_SLAVE); 7047 else 7048 hcon = hci_connect_le_scan(hdev, dst, dst_type, 7049 chan->sec_level, 7050 HCI_LE_CONN_TIMEOUT, 7051 CONN_REASON_L2CAP_CHAN); 7052 7053 } else { 7054 u8 auth_type = l2cap_get_auth_type(chan); 7055 hcon = hci_connect_acl(hdev, dst, chan->sec_level, auth_type, 7056 CONN_REASON_L2CAP_CHAN); 7057 } 7058 7059 if (IS_ERR(hcon)) { 7060 err = PTR_ERR(hcon); 7061 goto done; 7062 } 7063 7064 conn = l2cap_conn_add(hcon); 7065 if (!conn) { 7066 hci_conn_drop(hcon); 7067 err = -ENOMEM; 7068 goto done; 7069 } 7070 7071 if (chan->mode == L2CAP_MODE_EXT_FLOWCTL) { 7072 struct l2cap_chan_data data; 7073 7074 data.chan = chan; 7075 data.pid = chan->ops->get_peer_pid(chan); 7076 data.count = 1; 7077 7078 l2cap_chan_list(conn, l2cap_chan_by_pid, &data); 7079 7080 /* Check if there isn't too many channels being connected */ 7081 if (data.count > L2CAP_ECRED_CONN_SCID_MAX) { 7082 hci_conn_drop(hcon); 7083 err = -EPROTO; 7084 goto done; 7085 } 7086 } 7087 7088 mutex_lock(&conn->chan_lock); 7089 l2cap_chan_lock(chan); 7090 7091 if (cid && __l2cap_get_chan_by_dcid(conn, cid)) { 7092 hci_conn_drop(hcon); 7093 err = -EBUSY; 7094 goto chan_unlock; 7095 } 7096 7097 /* Update source addr of the socket */ 7098 bacpy(&chan->src, &hcon->src); 7099 chan->src_type = bdaddr_src_type(hcon); 7100 7101 __l2cap_chan_add(conn, chan); 7102 7103 /* l2cap_chan_add takes its own ref so we can drop this one */ 7104 hci_conn_drop(hcon); 7105 7106 l2cap_state_change(chan, BT_CONNECT); 7107 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan)); 7108 7109 /* Release chan->sport so that it can be reused by other 7110 * sockets (as it's only used for listening sockets). 7111 */ 7112 write_lock(&chan_list_lock); 7113 chan->sport = 0; 7114 write_unlock(&chan_list_lock); 7115 7116 if (hcon->state == BT_CONNECTED) { 7117 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) { 7118 __clear_chan_timer(chan); 7119 if (l2cap_chan_check_security(chan, true)) 7120 l2cap_state_change(chan, BT_CONNECTED); 7121 } else 7122 l2cap_do_start(chan); 7123 } 7124 7125 err = 0; 7126 7127 chan_unlock: 7128 l2cap_chan_unlock(chan); 7129 mutex_unlock(&conn->chan_lock); 7130 done: 7131 hci_dev_unlock(hdev); 7132 hci_dev_put(hdev); 7133 return err; 7134 } 7135 EXPORT_SYMBOL_GPL(l2cap_chan_connect); 7136 7137 static void l2cap_ecred_reconfigure(struct l2cap_chan *chan) 7138 { 7139 struct l2cap_conn *conn = chan->conn; 7140 struct { 7141 struct l2cap_ecred_reconf_req req; 7142 __le16 scid; 7143 } pdu; 7144 7145 pdu.req.mtu = cpu_to_le16(chan->imtu); 7146 pdu.req.mps = cpu_to_le16(chan->mps); 7147 pdu.scid = cpu_to_le16(chan->scid); 7148 7149 chan->ident = l2cap_get_ident(conn); 7150 7151 l2cap_send_cmd(conn, chan->ident, L2CAP_ECRED_RECONF_REQ, 7152 sizeof(pdu), &pdu); 7153 } 7154 7155 int l2cap_chan_reconfigure(struct l2cap_chan *chan, __u16 mtu) 7156 { 7157 if (chan->imtu > mtu) 7158 return -EINVAL; 7159 7160 BT_DBG("chan %p mtu 0x%4.4x", chan, mtu); 7161 7162 chan->imtu = mtu; 7163 7164 l2cap_ecred_reconfigure(chan); 7165 7166 return 0; 7167 } 7168 7169 /* ---- L2CAP interface with lower layer (HCI) ---- */ 7170 7171 int l2cap_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr) 7172 { 7173 int exact = 0, lm1 = 0, lm2 = 0; 7174 struct l2cap_chan *c; 7175 7176 BT_DBG("hdev %s, bdaddr %pMR", hdev->name, bdaddr); 7177 7178 /* Find listening sockets and check their link_mode */ 7179 read_lock(&chan_list_lock); 7180 list_for_each_entry(c, &chan_list, global_l) { 7181 if (c->state != BT_LISTEN) 7182 continue; 7183 7184 if (!bacmp(&c->src, &hdev->bdaddr)) { 7185 lm1 |= HCI_LM_ACCEPT; 7186 if (test_bit(FLAG_ROLE_SWITCH, &c->flags)) 7187 lm1 |= HCI_LM_MASTER; 7188 exact++; 7189 } else if (!bacmp(&c->src, BDADDR_ANY)) { 7190 lm2 |= HCI_LM_ACCEPT; 7191 if (test_bit(FLAG_ROLE_SWITCH, &c->flags)) 7192 lm2 |= HCI_LM_MASTER; 7193 } 7194 } 7195 read_unlock(&chan_list_lock); 7196 7197 return exact ? lm1 : lm2; 7198 } 7199 7200 /* Find the next fixed channel in BT_LISTEN state, continue iteration 7201 * from an existing channel in the list or from the beginning of the 7202 * global list (by passing NULL as first parameter). 7203 */ 7204 static struct l2cap_chan *l2cap_global_fixed_chan(struct l2cap_chan *c, 7205 struct hci_conn *hcon) 7206 { 7207 u8 src_type = bdaddr_src_type(hcon); 7208 7209 read_lock(&chan_list_lock); 7210 7211 if (c) 7212 c = list_next_entry(c, global_l); 7213 else 7214 c = list_entry(chan_list.next, typeof(*c), global_l); 7215 7216 list_for_each_entry_from(c, &chan_list, global_l) { 7217 if (c->chan_type != L2CAP_CHAN_FIXED) 7218 continue; 7219 if (c->state != BT_LISTEN) 7220 continue; 7221 if (bacmp(&c->src, &hcon->src) && bacmp(&c->src, BDADDR_ANY)) 7222 continue; 7223 if (src_type != c->src_type) 7224 continue; 7225 7226 c = l2cap_chan_hold_unless_zero(c); 7227 read_unlock(&chan_list_lock); 7228 return c; 7229 } 7230 7231 read_unlock(&chan_list_lock); 7232 7233 return NULL; 7234 } 7235 7236 static void l2cap_connect_cfm(struct hci_conn *hcon, u8 status) 7237 { 7238 struct hci_dev *hdev = hcon->hdev; 7239 struct l2cap_conn *conn; 7240 struct l2cap_chan *pchan; 7241 u8 dst_type; 7242 7243 if (hcon->type != ACL_LINK && hcon->type != LE_LINK) 7244 return; 7245 7246 BT_DBG("hcon %p bdaddr %pMR status %d", hcon, &hcon->dst, status); 7247 7248 if (status) { 7249 l2cap_conn_del(hcon, bt_to_errno(status)); 7250 return; 7251 } 7252 7253 conn = l2cap_conn_add(hcon); 7254 if (!conn) 7255 return; 7256 7257 dst_type = bdaddr_dst_type(hcon); 7258 7259 /* If device is blocked, do not create channels for it */ 7260 if (hci_bdaddr_list_lookup(&hdev->reject_list, &hcon->dst, dst_type)) 7261 return; 7262 7263 /* Find fixed channels and notify them of the new connection. We 7264 * use multiple individual lookups, continuing each time where 7265 * we left off, because the list lock would prevent calling the 7266 * potentially sleeping l2cap_chan_lock() function. 7267 */ 7268 pchan = l2cap_global_fixed_chan(NULL, hcon); 7269 while (pchan) { 7270 struct l2cap_chan *chan, *next; 7271 7272 /* Client fixed channels should override server ones */ 7273 if (__l2cap_get_chan_by_dcid(conn, pchan->scid)) 7274 goto next; 7275 7276 l2cap_chan_lock(pchan); 7277 chan = pchan->ops->new_connection(pchan); 7278 if (chan) { 7279 bacpy(&chan->src, &hcon->src); 7280 bacpy(&chan->dst, &hcon->dst); 7281 chan->src_type = bdaddr_src_type(hcon); 7282 chan->dst_type = dst_type; 7283 7284 __l2cap_chan_add(conn, chan); 7285 } 7286 7287 l2cap_chan_unlock(pchan); 7288 next: 7289 next = l2cap_global_fixed_chan(pchan, hcon); 7290 l2cap_chan_put(pchan); 7291 pchan = next; 7292 } 7293 7294 l2cap_conn_ready(conn); 7295 } 7296 7297 int l2cap_disconn_ind(struct hci_conn *hcon) 7298 { 7299 struct l2cap_conn *conn = hcon->l2cap_data; 7300 7301 BT_DBG("hcon %p", hcon); 7302 7303 if (!conn) 7304 return HCI_ERROR_REMOTE_USER_TERM; 7305 return conn->disc_reason; 7306 } 7307 7308 static void l2cap_disconn_cfm(struct hci_conn *hcon, u8 reason) 7309 { 7310 if (hcon->type != ACL_LINK && hcon->type != LE_LINK) 7311 return; 7312 7313 BT_DBG("hcon %p reason %d", hcon, reason); 7314 7315 l2cap_conn_del(hcon, bt_to_errno(reason)); 7316 } 7317 7318 static inline void l2cap_check_encryption(struct l2cap_chan *chan, u8 encrypt) 7319 { 7320 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) 7321 return; 7322 7323 if (encrypt == 0x00) { 7324 if (chan->sec_level == BT_SECURITY_MEDIUM) { 7325 __set_chan_timer(chan, L2CAP_ENC_TIMEOUT); 7326 } else if (chan->sec_level == BT_SECURITY_HIGH || 7327 chan->sec_level == BT_SECURITY_FIPS) 7328 l2cap_chan_close(chan, ECONNREFUSED); 7329 } else { 7330 if (chan->sec_level == BT_SECURITY_MEDIUM) 7331 __clear_chan_timer(chan); 7332 } 7333 } 7334 7335 static void l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt) 7336 { 7337 struct l2cap_conn *conn = hcon->l2cap_data; 7338 struct l2cap_chan *chan; 7339 7340 if (!conn) 7341 return; 7342 7343 BT_DBG("conn %p status 0x%2.2x encrypt %u", conn, status, encrypt); 7344 7345 mutex_lock(&conn->chan_lock); 7346 7347 list_for_each_entry(chan, &conn->chan_l, list) { 7348 l2cap_chan_lock(chan); 7349 7350 BT_DBG("chan %p scid 0x%4.4x state %s", chan, chan->scid, 7351 state_to_string(chan->state)); 7352 7353 if (!status && encrypt) 7354 chan->sec_level = hcon->sec_level; 7355 7356 if (!__l2cap_no_conn_pending(chan)) { 7357 l2cap_chan_unlock(chan); 7358 continue; 7359 } 7360 7361 if (!status && (chan->state == BT_CONNECTED || 7362 chan->state == BT_CONFIG)) { 7363 chan->ops->resume(chan); 7364 l2cap_check_encryption(chan, encrypt); 7365 l2cap_chan_unlock(chan); 7366 continue; 7367 } 7368 7369 if (chan->state == BT_CONNECT) { 7370 if (!status && l2cap_check_enc_key_size(hcon)) 7371 l2cap_start_connection(chan); 7372 else 7373 __set_chan_timer(chan, L2CAP_DISC_TIMEOUT); 7374 } else if (chan->state == BT_CONNECT2 && 7375 !(chan->mode == L2CAP_MODE_EXT_FLOWCTL || 7376 chan->mode == L2CAP_MODE_LE_FLOWCTL)) { 7377 struct l2cap_conn_rsp rsp; 7378 __u16 res, stat; 7379 7380 if (!status && l2cap_check_enc_key_size(hcon)) { 7381 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) { 7382 res = L2CAP_CR_PEND; 7383 stat = L2CAP_CS_AUTHOR_PEND; 7384 chan->ops->defer(chan); 7385 } else { 7386 l2cap_state_change(chan, BT_CONFIG); 7387 res = L2CAP_CR_SUCCESS; 7388 stat = L2CAP_CS_NO_INFO; 7389 } 7390 } else { 7391 l2cap_state_change(chan, BT_DISCONN); 7392 __set_chan_timer(chan, L2CAP_DISC_TIMEOUT); 7393 res = L2CAP_CR_SEC_BLOCK; 7394 stat = L2CAP_CS_NO_INFO; 7395 } 7396 7397 rsp.scid = cpu_to_le16(chan->dcid); 7398 rsp.dcid = cpu_to_le16(chan->scid); 7399 rsp.result = cpu_to_le16(res); 7400 rsp.status = cpu_to_le16(stat); 7401 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP, 7402 sizeof(rsp), &rsp); 7403 7404 if (!test_bit(CONF_REQ_SENT, &chan->conf_state) && 7405 res == L2CAP_CR_SUCCESS) { 7406 char buf[128]; 7407 set_bit(CONF_REQ_SENT, &chan->conf_state); 7408 l2cap_send_cmd(conn, l2cap_get_ident(conn), 7409 L2CAP_CONF_REQ, 7410 l2cap_build_conf_req(chan, buf, sizeof(buf)), 7411 buf); 7412 chan->num_conf_req++; 7413 } 7414 } 7415 7416 l2cap_chan_unlock(chan); 7417 } 7418 7419 mutex_unlock(&conn->chan_lock); 7420 } 7421 7422 /* Append fragment into frame respecting the maximum len of rx_skb */ 7423 static int l2cap_recv_frag(struct l2cap_conn *conn, struct sk_buff *skb, 7424 u16 len) 7425 { 7426 if (!conn->rx_skb) { 7427 /* Allocate skb for the complete frame (with header) */ 7428 conn->rx_skb = bt_skb_alloc(len, GFP_KERNEL); 7429 if (!conn->rx_skb) 7430 return -ENOMEM; 7431 /* Init rx_len */ 7432 conn->rx_len = len; 7433 } 7434 7435 /* Copy as much as the rx_skb can hold */ 7436 len = min_t(u16, len, skb->len); 7437 skb_copy_from_linear_data(skb, skb_put(conn->rx_skb, len), len); 7438 skb_pull(skb, len); 7439 conn->rx_len -= len; 7440 7441 return len; 7442 } 7443 7444 static int l2cap_recv_len(struct l2cap_conn *conn, struct sk_buff *skb) 7445 { 7446 struct sk_buff *rx_skb; 7447 int len; 7448 7449 /* Append just enough to complete the header */ 7450 len = l2cap_recv_frag(conn, skb, L2CAP_LEN_SIZE - conn->rx_skb->len); 7451 7452 /* If header could not be read just continue */ 7453 if (len < 0 || conn->rx_skb->len < L2CAP_LEN_SIZE) 7454 return len; 7455 7456 rx_skb = conn->rx_skb; 7457 len = get_unaligned_le16(rx_skb->data); 7458 7459 /* Check if rx_skb has enough space to received all fragments */ 7460 if (len + (L2CAP_HDR_SIZE - L2CAP_LEN_SIZE) <= skb_tailroom(rx_skb)) { 7461 /* Update expected len */ 7462 conn->rx_len = len + (L2CAP_HDR_SIZE - L2CAP_LEN_SIZE); 7463 return L2CAP_LEN_SIZE; 7464 } 7465 7466 /* Reset conn->rx_skb since it will need to be reallocated in order to 7467 * fit all fragments. 7468 */ 7469 conn->rx_skb = NULL; 7470 7471 /* Reallocates rx_skb using the exact expected length */ 7472 len = l2cap_recv_frag(conn, rx_skb, 7473 len + (L2CAP_HDR_SIZE - L2CAP_LEN_SIZE)); 7474 kfree_skb(rx_skb); 7475 7476 return len; 7477 } 7478 7479 static void l2cap_recv_reset(struct l2cap_conn *conn) 7480 { 7481 kfree_skb(conn->rx_skb); 7482 conn->rx_skb = NULL; 7483 conn->rx_len = 0; 7484 } 7485 7486 void l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 flags) 7487 { 7488 struct l2cap_conn *conn = hcon->l2cap_data; 7489 int len; 7490 7491 if (!conn) 7492 conn = l2cap_conn_add(hcon); 7493 7494 if (!conn) 7495 goto drop; 7496 7497 BT_DBG("conn %p len %u flags 0x%x", conn, skb->len, flags); 7498 7499 switch (flags) { 7500 case ACL_START: 7501 case ACL_START_NO_FLUSH: 7502 case ACL_COMPLETE: 7503 if (conn->rx_skb) { 7504 BT_ERR("Unexpected start frame (len %d)", skb->len); 7505 l2cap_recv_reset(conn); 7506 l2cap_conn_unreliable(conn, ECOMM); 7507 } 7508 7509 /* Start fragment may not contain the L2CAP length so just 7510 * copy the initial byte when that happens and use conn->mtu as 7511 * expected length. 7512 */ 7513 if (skb->len < L2CAP_LEN_SIZE) { 7514 l2cap_recv_frag(conn, skb, conn->mtu); 7515 break; 7516 } 7517 7518 len = get_unaligned_le16(skb->data) + L2CAP_HDR_SIZE; 7519 7520 if (len == skb->len) { 7521 /* Complete frame received */ 7522 l2cap_recv_frame(conn, skb); 7523 return; 7524 } 7525 7526 BT_DBG("Start: total len %d, frag len %u", len, skb->len); 7527 7528 if (skb->len > len) { 7529 BT_ERR("Frame is too long (len %u, expected len %d)", 7530 skb->len, len); 7531 l2cap_conn_unreliable(conn, ECOMM); 7532 goto drop; 7533 } 7534 7535 /* Append fragment into frame (with header) */ 7536 if (l2cap_recv_frag(conn, skb, len) < 0) 7537 goto drop; 7538 7539 break; 7540 7541 case ACL_CONT: 7542 BT_DBG("Cont: frag len %u (expecting %u)", skb->len, conn->rx_len); 7543 7544 if (!conn->rx_skb) { 7545 BT_ERR("Unexpected continuation frame (len %d)", skb->len); 7546 l2cap_conn_unreliable(conn, ECOMM); 7547 goto drop; 7548 } 7549 7550 /* Complete the L2CAP length if it has not been read */ 7551 if (conn->rx_skb->len < L2CAP_LEN_SIZE) { 7552 if (l2cap_recv_len(conn, skb) < 0) { 7553 l2cap_conn_unreliable(conn, ECOMM); 7554 goto drop; 7555 } 7556 7557 /* Header still could not be read just continue */ 7558 if (conn->rx_skb->len < L2CAP_LEN_SIZE) 7559 break; 7560 } 7561 7562 if (skb->len > conn->rx_len) { 7563 BT_ERR("Fragment is too long (len %u, expected %u)", 7564 skb->len, conn->rx_len); 7565 l2cap_recv_reset(conn); 7566 l2cap_conn_unreliable(conn, ECOMM); 7567 goto drop; 7568 } 7569 7570 /* Append fragment into frame (with header) */ 7571 l2cap_recv_frag(conn, skb, skb->len); 7572 7573 if (!conn->rx_len) { 7574 /* Complete frame received. l2cap_recv_frame 7575 * takes ownership of the skb so set the global 7576 * rx_skb pointer to NULL first. 7577 */ 7578 struct sk_buff *rx_skb = conn->rx_skb; 7579 conn->rx_skb = NULL; 7580 l2cap_recv_frame(conn, rx_skb); 7581 } 7582 break; 7583 } 7584 7585 drop: 7586 kfree_skb(skb); 7587 } 7588 7589 static struct hci_cb l2cap_cb = { 7590 .name = "L2CAP", 7591 .connect_cfm = l2cap_connect_cfm, 7592 .disconn_cfm = l2cap_disconn_cfm, 7593 .security_cfm = l2cap_security_cfm, 7594 }; 7595 7596 static int l2cap_debugfs_show(struct seq_file *f, void *p) 7597 { 7598 struct l2cap_chan *c; 7599 7600 read_lock(&chan_list_lock); 7601 7602 list_for_each_entry(c, &chan_list, global_l) { 7603 seq_printf(f, "%pMR (%u) %pMR (%u) %d %d 0x%4.4x 0x%4.4x %d %d %d %d\n", 7604 &c->src, c->src_type, &c->dst, c->dst_type, 7605 c->state, __le16_to_cpu(c->psm), 7606 c->scid, c->dcid, c->imtu, c->omtu, 7607 c->sec_level, c->mode); 7608 } 7609 7610 read_unlock(&chan_list_lock); 7611 7612 return 0; 7613 } 7614 7615 DEFINE_SHOW_ATTRIBUTE(l2cap_debugfs); 7616 7617 static struct dentry *l2cap_debugfs; 7618 7619 int __init l2cap_init(void) 7620 { 7621 int err; 7622 7623 err = l2cap_init_sockets(); 7624 if (err < 0) 7625 return err; 7626 7627 hci_register_cb(&l2cap_cb); 7628 7629 if (IS_ERR_OR_NULL(bt_debugfs)) 7630 return 0; 7631 7632 l2cap_debugfs = debugfs_create_file("l2cap", 0444, bt_debugfs, 7633 NULL, &l2cap_debugfs_fops); 7634 7635 return 0; 7636 } 7637 7638 void l2cap_exit(void) 7639 { 7640 debugfs_remove(l2cap_debugfs); 7641 hci_unregister_cb(&l2cap_cb); 7642 l2cap_cleanup_sockets(); 7643 } 7644 7645 module_param(disable_ertm, bool, 0644); 7646 MODULE_PARM_DESC(disable_ertm, "Disable enhanced retransmission mode"); 7647 7648 module_param(enable_ecred, bool, 0644); 7649 MODULE_PARM_DESC(enable_ecred, "Enable enhanced credit flow control mode"); 7650