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_hdr 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_hdr 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 struct l2cap_ecred_conn_rsp *rsp_flex = 3777 container_of(&rsp->pdu.rsp, struct l2cap_ecred_conn_rsp, hdr); 3778 3779 if (test_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags)) 3780 return; 3781 3782 /* Reset ident so only one response is sent */ 3783 chan->ident = 0; 3784 3785 /* Include all channels pending with the same ident */ 3786 if (!rsp->pdu.rsp.result) 3787 rsp_flex->dcid[rsp->count++] = cpu_to_le16(chan->scid); 3788 else 3789 l2cap_chan_del(chan, ECONNRESET); 3790 } 3791 3792 void __l2cap_ecred_conn_rsp_defer(struct l2cap_chan *chan) 3793 { 3794 struct l2cap_conn *conn = chan->conn; 3795 struct l2cap_ecred_rsp_data data; 3796 u16 id = chan->ident; 3797 int result = 0; 3798 3799 if (!id) 3800 return; 3801 3802 BT_DBG("chan %p id %d", chan, id); 3803 3804 memset(&data, 0, sizeof(data)); 3805 3806 data.pdu.rsp.mtu = cpu_to_le16(chan->imtu); 3807 data.pdu.rsp.mps = cpu_to_le16(chan->mps); 3808 data.pdu.rsp.credits = cpu_to_le16(chan->rx_credits); 3809 data.pdu.rsp.result = cpu_to_le16(L2CAP_CR_LE_SUCCESS); 3810 3811 /* Verify that all channels are ready */ 3812 __l2cap_chan_list_id(conn, id, l2cap_ecred_list_defer, &result); 3813 3814 if (result > 0) 3815 return; 3816 3817 if (result < 0) 3818 data.pdu.rsp.result = cpu_to_le16(L2CAP_CR_LE_AUTHORIZATION); 3819 3820 /* Build response */ 3821 __l2cap_chan_list_id(conn, id, l2cap_ecred_rsp_defer, &data); 3822 3823 l2cap_send_cmd(conn, id, L2CAP_ECRED_CONN_RSP, 3824 sizeof(data.pdu.rsp) + (data.count * sizeof(__le16)), 3825 &data.pdu); 3826 } 3827 3828 void __l2cap_connect_rsp_defer(struct l2cap_chan *chan) 3829 { 3830 struct l2cap_conn_rsp rsp; 3831 struct l2cap_conn *conn = chan->conn; 3832 u8 buf[128]; 3833 u8 rsp_code; 3834 3835 rsp.scid = cpu_to_le16(chan->dcid); 3836 rsp.dcid = cpu_to_le16(chan->scid); 3837 rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS); 3838 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO); 3839 rsp_code = L2CAP_CONN_RSP; 3840 3841 BT_DBG("chan %p rsp_code %u", chan, rsp_code); 3842 3843 l2cap_send_cmd(conn, chan->ident, rsp_code, sizeof(rsp), &rsp); 3844 3845 if (test_and_set_bit(CONF_REQ_SENT, &chan->conf_state)) 3846 return; 3847 3848 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ, 3849 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf); 3850 chan->num_conf_req++; 3851 } 3852 3853 static void l2cap_conf_rfc_get(struct l2cap_chan *chan, void *rsp, int len) 3854 { 3855 int type, olen; 3856 unsigned long val; 3857 /* Use sane default values in case a misbehaving remote device 3858 * did not send an RFC or extended window size option. 3859 */ 3860 u16 txwin_ext = chan->ack_win; 3861 struct l2cap_conf_rfc rfc = { 3862 .mode = chan->mode, 3863 .retrans_timeout = cpu_to_le16(L2CAP_DEFAULT_RETRANS_TO), 3864 .monitor_timeout = cpu_to_le16(L2CAP_DEFAULT_MONITOR_TO), 3865 .max_pdu_size = cpu_to_le16(chan->imtu), 3866 .txwin_size = min_t(u16, chan->ack_win, L2CAP_DEFAULT_TX_WINDOW), 3867 }; 3868 3869 BT_DBG("chan %p, rsp %p, len %d", chan, rsp, len); 3870 3871 if ((chan->mode != L2CAP_MODE_ERTM) && (chan->mode != L2CAP_MODE_STREAMING)) 3872 return; 3873 3874 while (len >= L2CAP_CONF_OPT_SIZE) { 3875 len -= l2cap_get_conf_opt(&rsp, &type, &olen, &val); 3876 if (len < 0) 3877 break; 3878 3879 switch (type) { 3880 case L2CAP_CONF_RFC: 3881 if (olen != sizeof(rfc)) 3882 break; 3883 memcpy(&rfc, (void *)val, olen); 3884 break; 3885 case L2CAP_CONF_EWS: 3886 if (olen != 2) 3887 break; 3888 txwin_ext = val; 3889 break; 3890 } 3891 } 3892 3893 switch (rfc.mode) { 3894 case L2CAP_MODE_ERTM: 3895 chan->retrans_timeout = le16_to_cpu(rfc.retrans_timeout); 3896 chan->monitor_timeout = le16_to_cpu(rfc.monitor_timeout); 3897 chan->mps = le16_to_cpu(rfc.max_pdu_size); 3898 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) 3899 chan->ack_win = min_t(u16, chan->ack_win, txwin_ext); 3900 else 3901 chan->ack_win = min_t(u16, chan->ack_win, 3902 rfc.txwin_size); 3903 break; 3904 case L2CAP_MODE_STREAMING: 3905 chan->mps = le16_to_cpu(rfc.max_pdu_size); 3906 } 3907 } 3908 3909 static inline int l2cap_command_rej(struct l2cap_conn *conn, 3910 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 3911 u8 *data) 3912 { 3913 struct l2cap_cmd_rej_unk *rej = (struct l2cap_cmd_rej_unk *) data; 3914 3915 if (cmd_len < sizeof(*rej)) 3916 return -EPROTO; 3917 3918 if (rej->reason != L2CAP_REJ_NOT_UNDERSTOOD) 3919 return 0; 3920 3921 if ((conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT) && 3922 cmd->ident == conn->info_ident) { 3923 cancel_delayed_work(&conn->info_timer); 3924 3925 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE; 3926 conn->info_ident = 0; 3927 3928 l2cap_conn_start(conn); 3929 } 3930 3931 return 0; 3932 } 3933 3934 static void l2cap_connect(struct l2cap_conn *conn, struct l2cap_cmd_hdr *cmd, 3935 u8 *data, u8 rsp_code) 3936 { 3937 struct l2cap_conn_req *req = (struct l2cap_conn_req *) data; 3938 struct l2cap_conn_rsp rsp; 3939 struct l2cap_chan *chan = NULL, *pchan = NULL; 3940 int result, status = L2CAP_CS_NO_INFO; 3941 3942 u16 dcid = 0, scid = __le16_to_cpu(req->scid); 3943 __le16 psm = req->psm; 3944 3945 BT_DBG("psm 0x%2.2x scid 0x%4.4x", __le16_to_cpu(psm), scid); 3946 3947 /* Check if we have socket listening on psm */ 3948 pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src, 3949 &conn->hcon->dst, ACL_LINK); 3950 if (!pchan) { 3951 result = L2CAP_CR_BAD_PSM; 3952 goto response; 3953 } 3954 3955 mutex_lock(&conn->chan_lock); 3956 l2cap_chan_lock(pchan); 3957 3958 /* Check if the ACL is secure enough (if not SDP) */ 3959 if (psm != cpu_to_le16(L2CAP_PSM_SDP) && 3960 !hci_conn_check_link_mode(conn->hcon)) { 3961 conn->disc_reason = HCI_ERROR_AUTH_FAILURE; 3962 result = L2CAP_CR_SEC_BLOCK; 3963 goto response; 3964 } 3965 3966 result = L2CAP_CR_NO_MEM; 3967 3968 /* Check for valid dynamic CID range (as per Erratum 3253) */ 3969 if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_DYN_END) { 3970 result = L2CAP_CR_INVALID_SCID; 3971 goto response; 3972 } 3973 3974 /* Check if we already have channel with that dcid */ 3975 if (__l2cap_get_chan_by_dcid(conn, scid)) { 3976 result = L2CAP_CR_SCID_IN_USE; 3977 goto response; 3978 } 3979 3980 chan = pchan->ops->new_connection(pchan); 3981 if (!chan) 3982 goto response; 3983 3984 /* For certain devices (ex: HID mouse), support for authentication, 3985 * pairing and bonding is optional. For such devices, inorder to avoid 3986 * the ACL alive for too long after L2CAP disconnection, reset the ACL 3987 * disc_timeout back to HCI_DISCONN_TIMEOUT during L2CAP connect. 3988 */ 3989 conn->hcon->disc_timeout = HCI_DISCONN_TIMEOUT; 3990 3991 bacpy(&chan->src, &conn->hcon->src); 3992 bacpy(&chan->dst, &conn->hcon->dst); 3993 chan->src_type = bdaddr_src_type(conn->hcon); 3994 chan->dst_type = bdaddr_dst_type(conn->hcon); 3995 chan->psm = psm; 3996 chan->dcid = scid; 3997 3998 __l2cap_chan_add(conn, chan); 3999 4000 dcid = chan->scid; 4001 4002 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan)); 4003 4004 chan->ident = cmd->ident; 4005 4006 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE) { 4007 if (l2cap_chan_check_security(chan, false)) { 4008 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) { 4009 l2cap_state_change(chan, BT_CONNECT2); 4010 result = L2CAP_CR_PEND; 4011 status = L2CAP_CS_AUTHOR_PEND; 4012 chan->ops->defer(chan); 4013 } else { 4014 l2cap_state_change(chan, BT_CONFIG); 4015 result = L2CAP_CR_SUCCESS; 4016 status = L2CAP_CS_NO_INFO; 4017 } 4018 } else { 4019 l2cap_state_change(chan, BT_CONNECT2); 4020 result = L2CAP_CR_PEND; 4021 status = L2CAP_CS_AUTHEN_PEND; 4022 } 4023 } else { 4024 l2cap_state_change(chan, BT_CONNECT2); 4025 result = L2CAP_CR_PEND; 4026 status = L2CAP_CS_NO_INFO; 4027 } 4028 4029 response: 4030 rsp.scid = cpu_to_le16(scid); 4031 rsp.dcid = cpu_to_le16(dcid); 4032 rsp.result = cpu_to_le16(result); 4033 rsp.status = cpu_to_le16(status); 4034 l2cap_send_cmd(conn, cmd->ident, rsp_code, sizeof(rsp), &rsp); 4035 4036 if (!pchan) 4037 return; 4038 4039 if (result == L2CAP_CR_PEND && status == L2CAP_CS_NO_INFO) { 4040 struct l2cap_info_req info; 4041 info.type = cpu_to_le16(L2CAP_IT_FEAT_MASK); 4042 4043 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_SENT; 4044 conn->info_ident = l2cap_get_ident(conn); 4045 4046 schedule_delayed_work(&conn->info_timer, L2CAP_INFO_TIMEOUT); 4047 4048 l2cap_send_cmd(conn, conn->info_ident, L2CAP_INFO_REQ, 4049 sizeof(info), &info); 4050 } 4051 4052 if (chan && !test_bit(CONF_REQ_SENT, &chan->conf_state) && 4053 result == L2CAP_CR_SUCCESS) { 4054 u8 buf[128]; 4055 set_bit(CONF_REQ_SENT, &chan->conf_state); 4056 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ, 4057 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf); 4058 chan->num_conf_req++; 4059 } 4060 4061 l2cap_chan_unlock(pchan); 4062 mutex_unlock(&conn->chan_lock); 4063 l2cap_chan_put(pchan); 4064 } 4065 4066 static int l2cap_connect_req(struct l2cap_conn *conn, 4067 struct l2cap_cmd_hdr *cmd, u16 cmd_len, u8 *data) 4068 { 4069 struct hci_dev *hdev = conn->hcon->hdev; 4070 struct hci_conn *hcon = conn->hcon; 4071 4072 if (cmd_len < sizeof(struct l2cap_conn_req)) 4073 return -EPROTO; 4074 4075 hci_dev_lock(hdev); 4076 if (hci_dev_test_flag(hdev, HCI_MGMT)) 4077 mgmt_device_connected(hdev, hcon, NULL, 0); 4078 hci_dev_unlock(hdev); 4079 4080 l2cap_connect(conn, cmd, data, L2CAP_CONN_RSP); 4081 return 0; 4082 } 4083 4084 static int l2cap_connect_create_rsp(struct l2cap_conn *conn, 4085 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4086 u8 *data) 4087 { 4088 struct l2cap_conn_rsp *rsp = (struct l2cap_conn_rsp *) data; 4089 u16 scid, dcid, result, status; 4090 struct l2cap_chan *chan; 4091 u8 req[128]; 4092 int err; 4093 4094 if (cmd_len < sizeof(*rsp)) 4095 return -EPROTO; 4096 4097 scid = __le16_to_cpu(rsp->scid); 4098 dcid = __le16_to_cpu(rsp->dcid); 4099 result = __le16_to_cpu(rsp->result); 4100 status = __le16_to_cpu(rsp->status); 4101 4102 if (result == L2CAP_CR_SUCCESS && (dcid < L2CAP_CID_DYN_START || 4103 dcid > L2CAP_CID_DYN_END)) 4104 return -EPROTO; 4105 4106 BT_DBG("dcid 0x%4.4x scid 0x%4.4x result 0x%2.2x status 0x%2.2x", 4107 dcid, scid, result, status); 4108 4109 mutex_lock(&conn->chan_lock); 4110 4111 if (scid) { 4112 chan = __l2cap_get_chan_by_scid(conn, scid); 4113 if (!chan) { 4114 err = -EBADSLT; 4115 goto unlock; 4116 } 4117 } else { 4118 chan = __l2cap_get_chan_by_ident(conn, cmd->ident); 4119 if (!chan) { 4120 err = -EBADSLT; 4121 goto unlock; 4122 } 4123 } 4124 4125 chan = l2cap_chan_hold_unless_zero(chan); 4126 if (!chan) { 4127 err = -EBADSLT; 4128 goto unlock; 4129 } 4130 4131 err = 0; 4132 4133 l2cap_chan_lock(chan); 4134 4135 switch (result) { 4136 case L2CAP_CR_SUCCESS: 4137 if (__l2cap_get_chan_by_dcid(conn, dcid)) { 4138 err = -EBADSLT; 4139 break; 4140 } 4141 4142 l2cap_state_change(chan, BT_CONFIG); 4143 chan->ident = 0; 4144 chan->dcid = dcid; 4145 clear_bit(CONF_CONNECT_PEND, &chan->conf_state); 4146 4147 if (test_and_set_bit(CONF_REQ_SENT, &chan->conf_state)) 4148 break; 4149 4150 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ, 4151 l2cap_build_conf_req(chan, req, sizeof(req)), req); 4152 chan->num_conf_req++; 4153 break; 4154 4155 case L2CAP_CR_PEND: 4156 set_bit(CONF_CONNECT_PEND, &chan->conf_state); 4157 break; 4158 4159 default: 4160 l2cap_chan_del(chan, ECONNREFUSED); 4161 break; 4162 } 4163 4164 l2cap_chan_unlock(chan); 4165 l2cap_chan_put(chan); 4166 4167 unlock: 4168 mutex_unlock(&conn->chan_lock); 4169 4170 return err; 4171 } 4172 4173 static inline void set_default_fcs(struct l2cap_chan *chan) 4174 { 4175 /* FCS is enabled only in ERTM or streaming mode, if one or both 4176 * sides request it. 4177 */ 4178 if (chan->mode != L2CAP_MODE_ERTM && chan->mode != L2CAP_MODE_STREAMING) 4179 chan->fcs = L2CAP_FCS_NONE; 4180 else if (!test_bit(CONF_RECV_NO_FCS, &chan->conf_state)) 4181 chan->fcs = L2CAP_FCS_CRC16; 4182 } 4183 4184 static void l2cap_send_efs_conf_rsp(struct l2cap_chan *chan, void *data, 4185 u8 ident, u16 flags) 4186 { 4187 struct l2cap_conn *conn = chan->conn; 4188 4189 BT_DBG("conn %p chan %p ident %d flags 0x%4.4x", conn, chan, ident, 4190 flags); 4191 4192 clear_bit(CONF_LOC_CONF_PEND, &chan->conf_state); 4193 set_bit(CONF_OUTPUT_DONE, &chan->conf_state); 4194 4195 l2cap_send_cmd(conn, ident, L2CAP_CONF_RSP, 4196 l2cap_build_conf_rsp(chan, data, 4197 L2CAP_CONF_SUCCESS, flags), data); 4198 } 4199 4200 static void cmd_reject_invalid_cid(struct l2cap_conn *conn, u8 ident, 4201 u16 scid, u16 dcid) 4202 { 4203 struct l2cap_cmd_rej_cid rej; 4204 4205 rej.reason = cpu_to_le16(L2CAP_REJ_INVALID_CID); 4206 rej.scid = __cpu_to_le16(scid); 4207 rej.dcid = __cpu_to_le16(dcid); 4208 4209 l2cap_send_cmd(conn, ident, L2CAP_COMMAND_REJ, sizeof(rej), &rej); 4210 } 4211 4212 static inline int l2cap_config_req(struct l2cap_conn *conn, 4213 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4214 u8 *data) 4215 { 4216 struct l2cap_conf_req *req = (struct l2cap_conf_req *) data; 4217 u16 dcid, flags; 4218 u8 rsp[64]; 4219 struct l2cap_chan *chan; 4220 int len, err = 0; 4221 4222 if (cmd_len < sizeof(*req)) 4223 return -EPROTO; 4224 4225 dcid = __le16_to_cpu(req->dcid); 4226 flags = __le16_to_cpu(req->flags); 4227 4228 BT_DBG("dcid 0x%4.4x flags 0x%2.2x", dcid, flags); 4229 4230 chan = l2cap_get_chan_by_scid(conn, dcid); 4231 if (!chan) { 4232 cmd_reject_invalid_cid(conn, cmd->ident, dcid, 0); 4233 return 0; 4234 } 4235 4236 if (chan->state != BT_CONFIG && chan->state != BT_CONNECT2 && 4237 chan->state != BT_CONNECTED) { 4238 cmd_reject_invalid_cid(conn, cmd->ident, chan->scid, 4239 chan->dcid); 4240 goto unlock; 4241 } 4242 4243 /* Reject if config buffer is too small. */ 4244 len = cmd_len - sizeof(*req); 4245 if (chan->conf_len + len > sizeof(chan->conf_req)) { 4246 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP, 4247 l2cap_build_conf_rsp(chan, rsp, 4248 L2CAP_CONF_REJECT, flags), rsp); 4249 goto unlock; 4250 } 4251 4252 /* Store config. */ 4253 memcpy(chan->conf_req + chan->conf_len, req->data, len); 4254 chan->conf_len += len; 4255 4256 if (flags & L2CAP_CONF_FLAG_CONTINUATION) { 4257 /* Incomplete config. Send empty response. */ 4258 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP, 4259 l2cap_build_conf_rsp(chan, rsp, 4260 L2CAP_CONF_SUCCESS, flags), rsp); 4261 goto unlock; 4262 } 4263 4264 /* Complete config. */ 4265 len = l2cap_parse_conf_req(chan, rsp, sizeof(rsp)); 4266 if (len < 0) { 4267 l2cap_send_disconn_req(chan, ECONNRESET); 4268 goto unlock; 4269 } 4270 4271 chan->ident = cmd->ident; 4272 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP, len, rsp); 4273 if (chan->num_conf_rsp < L2CAP_CONF_MAX_CONF_RSP) 4274 chan->num_conf_rsp++; 4275 4276 /* Reset config buffer. */ 4277 chan->conf_len = 0; 4278 4279 if (!test_bit(CONF_OUTPUT_DONE, &chan->conf_state)) 4280 goto unlock; 4281 4282 if (test_bit(CONF_INPUT_DONE, &chan->conf_state)) { 4283 set_default_fcs(chan); 4284 4285 if (chan->mode == L2CAP_MODE_ERTM || 4286 chan->mode == L2CAP_MODE_STREAMING) 4287 err = l2cap_ertm_init(chan); 4288 4289 if (err < 0) 4290 l2cap_send_disconn_req(chan, -err); 4291 else 4292 l2cap_chan_ready(chan); 4293 4294 goto unlock; 4295 } 4296 4297 if (!test_and_set_bit(CONF_REQ_SENT, &chan->conf_state)) { 4298 u8 buf[64]; 4299 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ, 4300 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf); 4301 chan->num_conf_req++; 4302 } 4303 4304 /* Got Conf Rsp PENDING from remote side and assume we sent 4305 Conf Rsp PENDING in the code above */ 4306 if (test_bit(CONF_REM_CONF_PEND, &chan->conf_state) && 4307 test_bit(CONF_LOC_CONF_PEND, &chan->conf_state)) { 4308 4309 /* check compatibility */ 4310 4311 /* Send rsp for BR/EDR channel */ 4312 l2cap_send_efs_conf_rsp(chan, rsp, cmd->ident, flags); 4313 } 4314 4315 unlock: 4316 l2cap_chan_unlock(chan); 4317 l2cap_chan_put(chan); 4318 return err; 4319 } 4320 4321 static inline int l2cap_config_rsp(struct l2cap_conn *conn, 4322 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4323 u8 *data) 4324 { 4325 struct l2cap_conf_rsp *rsp = (struct l2cap_conf_rsp *)data; 4326 u16 scid, flags, result; 4327 struct l2cap_chan *chan; 4328 int len = cmd_len - sizeof(*rsp); 4329 int err = 0; 4330 4331 if (cmd_len < sizeof(*rsp)) 4332 return -EPROTO; 4333 4334 scid = __le16_to_cpu(rsp->scid); 4335 flags = __le16_to_cpu(rsp->flags); 4336 result = __le16_to_cpu(rsp->result); 4337 4338 BT_DBG("scid 0x%4.4x flags 0x%2.2x result 0x%2.2x len %d", scid, flags, 4339 result, len); 4340 4341 chan = l2cap_get_chan_by_scid(conn, scid); 4342 if (!chan) 4343 return 0; 4344 4345 switch (result) { 4346 case L2CAP_CONF_SUCCESS: 4347 l2cap_conf_rfc_get(chan, rsp->data, len); 4348 clear_bit(CONF_REM_CONF_PEND, &chan->conf_state); 4349 break; 4350 4351 case L2CAP_CONF_PENDING: 4352 set_bit(CONF_REM_CONF_PEND, &chan->conf_state); 4353 4354 if (test_bit(CONF_LOC_CONF_PEND, &chan->conf_state)) { 4355 char buf[64]; 4356 4357 len = l2cap_parse_conf_rsp(chan, rsp->data, len, 4358 buf, sizeof(buf), &result); 4359 if (len < 0) { 4360 l2cap_send_disconn_req(chan, ECONNRESET); 4361 goto done; 4362 } 4363 4364 l2cap_send_efs_conf_rsp(chan, buf, cmd->ident, 0); 4365 } 4366 goto done; 4367 4368 case L2CAP_CONF_UNKNOWN: 4369 case L2CAP_CONF_UNACCEPT: 4370 if (chan->num_conf_rsp <= L2CAP_CONF_MAX_CONF_RSP) { 4371 char req[64]; 4372 4373 if (len > sizeof(req) - sizeof(struct l2cap_conf_req)) { 4374 l2cap_send_disconn_req(chan, ECONNRESET); 4375 goto done; 4376 } 4377 4378 /* throw out any old stored conf requests */ 4379 result = L2CAP_CONF_SUCCESS; 4380 len = l2cap_parse_conf_rsp(chan, rsp->data, len, 4381 req, sizeof(req), &result); 4382 if (len < 0) { 4383 l2cap_send_disconn_req(chan, ECONNRESET); 4384 goto done; 4385 } 4386 4387 l2cap_send_cmd(conn, l2cap_get_ident(conn), 4388 L2CAP_CONF_REQ, len, req); 4389 chan->num_conf_req++; 4390 if (result != L2CAP_CONF_SUCCESS) 4391 goto done; 4392 break; 4393 } 4394 fallthrough; 4395 4396 default: 4397 l2cap_chan_set_err(chan, ECONNRESET); 4398 4399 __set_chan_timer(chan, L2CAP_DISC_REJ_TIMEOUT); 4400 l2cap_send_disconn_req(chan, ECONNRESET); 4401 goto done; 4402 } 4403 4404 if (flags & L2CAP_CONF_FLAG_CONTINUATION) 4405 goto done; 4406 4407 set_bit(CONF_INPUT_DONE, &chan->conf_state); 4408 4409 if (test_bit(CONF_OUTPUT_DONE, &chan->conf_state)) { 4410 set_default_fcs(chan); 4411 4412 if (chan->mode == L2CAP_MODE_ERTM || 4413 chan->mode == L2CAP_MODE_STREAMING) 4414 err = l2cap_ertm_init(chan); 4415 4416 if (err < 0) 4417 l2cap_send_disconn_req(chan, -err); 4418 else 4419 l2cap_chan_ready(chan); 4420 } 4421 4422 done: 4423 l2cap_chan_unlock(chan); 4424 l2cap_chan_put(chan); 4425 return err; 4426 } 4427 4428 static inline int l2cap_disconnect_req(struct l2cap_conn *conn, 4429 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4430 u8 *data) 4431 { 4432 struct l2cap_disconn_req *req = (struct l2cap_disconn_req *) data; 4433 struct l2cap_disconn_rsp rsp; 4434 u16 dcid, scid; 4435 struct l2cap_chan *chan; 4436 4437 if (cmd_len != sizeof(*req)) 4438 return -EPROTO; 4439 4440 scid = __le16_to_cpu(req->scid); 4441 dcid = __le16_to_cpu(req->dcid); 4442 4443 BT_DBG("scid 0x%4.4x dcid 0x%4.4x", scid, dcid); 4444 4445 chan = l2cap_get_chan_by_scid(conn, dcid); 4446 if (!chan) { 4447 cmd_reject_invalid_cid(conn, cmd->ident, dcid, scid); 4448 return 0; 4449 } 4450 4451 rsp.dcid = cpu_to_le16(chan->scid); 4452 rsp.scid = cpu_to_le16(chan->dcid); 4453 l2cap_send_cmd(conn, cmd->ident, L2CAP_DISCONN_RSP, sizeof(rsp), &rsp); 4454 4455 chan->ops->set_shutdown(chan); 4456 4457 l2cap_chan_unlock(chan); 4458 mutex_lock(&conn->chan_lock); 4459 l2cap_chan_lock(chan); 4460 l2cap_chan_del(chan, ECONNRESET); 4461 mutex_unlock(&conn->chan_lock); 4462 4463 chan->ops->close(chan); 4464 4465 l2cap_chan_unlock(chan); 4466 l2cap_chan_put(chan); 4467 4468 return 0; 4469 } 4470 4471 static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn, 4472 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4473 u8 *data) 4474 { 4475 struct l2cap_disconn_rsp *rsp = (struct l2cap_disconn_rsp *) data; 4476 u16 dcid, scid; 4477 struct l2cap_chan *chan; 4478 4479 if (cmd_len != sizeof(*rsp)) 4480 return -EPROTO; 4481 4482 scid = __le16_to_cpu(rsp->scid); 4483 dcid = __le16_to_cpu(rsp->dcid); 4484 4485 BT_DBG("dcid 0x%4.4x scid 0x%4.4x", dcid, scid); 4486 4487 chan = l2cap_get_chan_by_scid(conn, scid); 4488 if (!chan) { 4489 return 0; 4490 } 4491 4492 if (chan->state != BT_DISCONN) { 4493 l2cap_chan_unlock(chan); 4494 l2cap_chan_put(chan); 4495 return 0; 4496 } 4497 4498 l2cap_chan_unlock(chan); 4499 mutex_lock(&conn->chan_lock); 4500 l2cap_chan_lock(chan); 4501 l2cap_chan_del(chan, 0); 4502 mutex_unlock(&conn->chan_lock); 4503 4504 chan->ops->close(chan); 4505 4506 l2cap_chan_unlock(chan); 4507 l2cap_chan_put(chan); 4508 4509 return 0; 4510 } 4511 4512 static inline int l2cap_information_req(struct l2cap_conn *conn, 4513 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4514 u8 *data) 4515 { 4516 struct l2cap_info_req *req = (struct l2cap_info_req *) data; 4517 u16 type; 4518 4519 if (cmd_len != sizeof(*req)) 4520 return -EPROTO; 4521 4522 type = __le16_to_cpu(req->type); 4523 4524 BT_DBG("type 0x%4.4x", type); 4525 4526 if (type == L2CAP_IT_FEAT_MASK) { 4527 u8 buf[8]; 4528 u32 feat_mask = l2cap_feat_mask; 4529 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) buf; 4530 rsp->type = cpu_to_le16(L2CAP_IT_FEAT_MASK); 4531 rsp->result = cpu_to_le16(L2CAP_IR_SUCCESS); 4532 if (!disable_ertm) 4533 feat_mask |= L2CAP_FEAT_ERTM | L2CAP_FEAT_STREAMING 4534 | L2CAP_FEAT_FCS; 4535 4536 put_unaligned_le32(feat_mask, rsp->data); 4537 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(buf), 4538 buf); 4539 } else if (type == L2CAP_IT_FIXED_CHAN) { 4540 u8 buf[12]; 4541 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) buf; 4542 4543 rsp->type = cpu_to_le16(L2CAP_IT_FIXED_CHAN); 4544 rsp->result = cpu_to_le16(L2CAP_IR_SUCCESS); 4545 rsp->data[0] = conn->local_fixed_chan; 4546 memset(rsp->data + 1, 0, 7); 4547 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(buf), 4548 buf); 4549 } else { 4550 struct l2cap_info_rsp rsp; 4551 rsp.type = cpu_to_le16(type); 4552 rsp.result = cpu_to_le16(L2CAP_IR_NOTSUPP); 4553 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(rsp), 4554 &rsp); 4555 } 4556 4557 return 0; 4558 } 4559 4560 static inline int l2cap_information_rsp(struct l2cap_conn *conn, 4561 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4562 u8 *data) 4563 { 4564 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) data; 4565 u16 type, result; 4566 4567 if (cmd_len < sizeof(*rsp)) 4568 return -EPROTO; 4569 4570 type = __le16_to_cpu(rsp->type); 4571 result = __le16_to_cpu(rsp->result); 4572 4573 BT_DBG("type 0x%4.4x result 0x%2.2x", type, result); 4574 4575 /* L2CAP Info req/rsp are unbound to channels, add extra checks */ 4576 if (cmd->ident != conn->info_ident || 4577 conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE) 4578 return 0; 4579 4580 cancel_delayed_work(&conn->info_timer); 4581 4582 if (result != L2CAP_IR_SUCCESS) { 4583 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE; 4584 conn->info_ident = 0; 4585 4586 l2cap_conn_start(conn); 4587 4588 return 0; 4589 } 4590 4591 switch (type) { 4592 case L2CAP_IT_FEAT_MASK: 4593 conn->feat_mask = get_unaligned_le32(rsp->data); 4594 4595 if (conn->feat_mask & L2CAP_FEAT_FIXED_CHAN) { 4596 struct l2cap_info_req req; 4597 req.type = cpu_to_le16(L2CAP_IT_FIXED_CHAN); 4598 4599 conn->info_ident = l2cap_get_ident(conn); 4600 4601 l2cap_send_cmd(conn, conn->info_ident, 4602 L2CAP_INFO_REQ, sizeof(req), &req); 4603 } else { 4604 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE; 4605 conn->info_ident = 0; 4606 4607 l2cap_conn_start(conn); 4608 } 4609 break; 4610 4611 case L2CAP_IT_FIXED_CHAN: 4612 conn->remote_fixed_chan = rsp->data[0]; 4613 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE; 4614 conn->info_ident = 0; 4615 4616 l2cap_conn_start(conn); 4617 break; 4618 } 4619 4620 return 0; 4621 } 4622 4623 static inline int l2cap_conn_param_update_req(struct l2cap_conn *conn, 4624 struct l2cap_cmd_hdr *cmd, 4625 u16 cmd_len, u8 *data) 4626 { 4627 struct hci_conn *hcon = conn->hcon; 4628 struct l2cap_conn_param_update_req *req; 4629 struct l2cap_conn_param_update_rsp rsp; 4630 u16 min, max, latency, to_multiplier; 4631 int err; 4632 4633 if (hcon->role != HCI_ROLE_MASTER) 4634 return -EINVAL; 4635 4636 if (cmd_len != sizeof(struct l2cap_conn_param_update_req)) 4637 return -EPROTO; 4638 4639 req = (struct l2cap_conn_param_update_req *) data; 4640 min = __le16_to_cpu(req->min); 4641 max = __le16_to_cpu(req->max); 4642 latency = __le16_to_cpu(req->latency); 4643 to_multiplier = __le16_to_cpu(req->to_multiplier); 4644 4645 BT_DBG("min 0x%4.4x max 0x%4.4x latency: 0x%4.4x Timeout: 0x%4.4x", 4646 min, max, latency, to_multiplier); 4647 4648 memset(&rsp, 0, sizeof(rsp)); 4649 4650 err = hci_check_conn_params(min, max, latency, to_multiplier); 4651 if (err) 4652 rsp.result = cpu_to_le16(L2CAP_CONN_PARAM_REJECTED); 4653 else 4654 rsp.result = cpu_to_le16(L2CAP_CONN_PARAM_ACCEPTED); 4655 4656 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONN_PARAM_UPDATE_RSP, 4657 sizeof(rsp), &rsp); 4658 4659 if (!err) { 4660 u8 store_hint; 4661 4662 store_hint = hci_le_conn_update(hcon, min, max, latency, 4663 to_multiplier); 4664 mgmt_new_conn_param(hcon->hdev, &hcon->dst, hcon->dst_type, 4665 store_hint, min, max, latency, 4666 to_multiplier); 4667 4668 } 4669 4670 return 0; 4671 } 4672 4673 static int l2cap_le_connect_rsp(struct l2cap_conn *conn, 4674 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4675 u8 *data) 4676 { 4677 struct l2cap_le_conn_rsp *rsp = (struct l2cap_le_conn_rsp *) data; 4678 struct hci_conn *hcon = conn->hcon; 4679 u16 dcid, mtu, mps, credits, result; 4680 struct l2cap_chan *chan; 4681 int err, sec_level; 4682 4683 if (cmd_len < sizeof(*rsp)) 4684 return -EPROTO; 4685 4686 dcid = __le16_to_cpu(rsp->dcid); 4687 mtu = __le16_to_cpu(rsp->mtu); 4688 mps = __le16_to_cpu(rsp->mps); 4689 credits = __le16_to_cpu(rsp->credits); 4690 result = __le16_to_cpu(rsp->result); 4691 4692 if (result == L2CAP_CR_LE_SUCCESS && (mtu < 23 || mps < 23 || 4693 dcid < L2CAP_CID_DYN_START || 4694 dcid > L2CAP_CID_LE_DYN_END)) 4695 return -EPROTO; 4696 4697 BT_DBG("dcid 0x%4.4x mtu %u mps %u credits %u result 0x%2.2x", 4698 dcid, mtu, mps, credits, result); 4699 4700 mutex_lock(&conn->chan_lock); 4701 4702 chan = __l2cap_get_chan_by_ident(conn, cmd->ident); 4703 if (!chan) { 4704 err = -EBADSLT; 4705 goto unlock; 4706 } 4707 4708 err = 0; 4709 4710 l2cap_chan_lock(chan); 4711 4712 switch (result) { 4713 case L2CAP_CR_LE_SUCCESS: 4714 if (__l2cap_get_chan_by_dcid(conn, dcid)) { 4715 err = -EBADSLT; 4716 break; 4717 } 4718 4719 chan->ident = 0; 4720 chan->dcid = dcid; 4721 chan->omtu = mtu; 4722 chan->remote_mps = mps; 4723 chan->tx_credits = credits; 4724 l2cap_chan_ready(chan); 4725 break; 4726 4727 case L2CAP_CR_LE_AUTHENTICATION: 4728 case L2CAP_CR_LE_ENCRYPTION: 4729 /* If we already have MITM protection we can't do 4730 * anything. 4731 */ 4732 if (hcon->sec_level > BT_SECURITY_MEDIUM) { 4733 l2cap_chan_del(chan, ECONNREFUSED); 4734 break; 4735 } 4736 4737 sec_level = hcon->sec_level + 1; 4738 if (chan->sec_level < sec_level) 4739 chan->sec_level = sec_level; 4740 4741 /* We'll need to send a new Connect Request */ 4742 clear_bit(FLAG_LE_CONN_REQ_SENT, &chan->flags); 4743 4744 smp_conn_security(hcon, chan->sec_level); 4745 break; 4746 4747 default: 4748 l2cap_chan_del(chan, ECONNREFUSED); 4749 break; 4750 } 4751 4752 l2cap_chan_unlock(chan); 4753 4754 unlock: 4755 mutex_unlock(&conn->chan_lock); 4756 4757 return err; 4758 } 4759 4760 static inline int l2cap_bredr_sig_cmd(struct l2cap_conn *conn, 4761 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4762 u8 *data) 4763 { 4764 int err = 0; 4765 4766 switch (cmd->code) { 4767 case L2CAP_COMMAND_REJ: 4768 l2cap_command_rej(conn, cmd, cmd_len, data); 4769 break; 4770 4771 case L2CAP_CONN_REQ: 4772 err = l2cap_connect_req(conn, cmd, cmd_len, data); 4773 break; 4774 4775 case L2CAP_CONN_RSP: 4776 l2cap_connect_create_rsp(conn, cmd, cmd_len, data); 4777 break; 4778 4779 case L2CAP_CONF_REQ: 4780 err = l2cap_config_req(conn, cmd, cmd_len, data); 4781 break; 4782 4783 case L2CAP_CONF_RSP: 4784 l2cap_config_rsp(conn, cmd, cmd_len, data); 4785 break; 4786 4787 case L2CAP_DISCONN_REQ: 4788 err = l2cap_disconnect_req(conn, cmd, cmd_len, data); 4789 break; 4790 4791 case L2CAP_DISCONN_RSP: 4792 l2cap_disconnect_rsp(conn, cmd, cmd_len, data); 4793 break; 4794 4795 case L2CAP_ECHO_REQ: 4796 l2cap_send_cmd(conn, cmd->ident, L2CAP_ECHO_RSP, cmd_len, data); 4797 break; 4798 4799 case L2CAP_ECHO_RSP: 4800 break; 4801 4802 case L2CAP_INFO_REQ: 4803 err = l2cap_information_req(conn, cmd, cmd_len, data); 4804 break; 4805 4806 case L2CAP_INFO_RSP: 4807 l2cap_information_rsp(conn, cmd, cmd_len, data); 4808 break; 4809 4810 default: 4811 BT_ERR("Unknown BR/EDR signaling command 0x%2.2x", cmd->code); 4812 err = -EINVAL; 4813 break; 4814 } 4815 4816 return err; 4817 } 4818 4819 static int l2cap_le_connect_req(struct l2cap_conn *conn, 4820 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4821 u8 *data) 4822 { 4823 struct l2cap_le_conn_req *req = (struct l2cap_le_conn_req *) data; 4824 struct l2cap_le_conn_rsp rsp; 4825 struct l2cap_chan *chan, *pchan; 4826 u16 dcid, scid, credits, mtu, mps; 4827 __le16 psm; 4828 u8 result; 4829 4830 if (cmd_len != sizeof(*req)) 4831 return -EPROTO; 4832 4833 scid = __le16_to_cpu(req->scid); 4834 mtu = __le16_to_cpu(req->mtu); 4835 mps = __le16_to_cpu(req->mps); 4836 psm = req->psm; 4837 dcid = 0; 4838 credits = 0; 4839 4840 if (mtu < 23 || mps < 23) 4841 return -EPROTO; 4842 4843 BT_DBG("psm 0x%2.2x scid 0x%4.4x mtu %u mps %u", __le16_to_cpu(psm), 4844 scid, mtu, mps); 4845 4846 /* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A 4847 * page 1059: 4848 * 4849 * Valid range: 0x0001-0x00ff 4850 * 4851 * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges 4852 */ 4853 if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) { 4854 result = L2CAP_CR_LE_BAD_PSM; 4855 chan = NULL; 4856 goto response; 4857 } 4858 4859 /* Check if we have socket listening on psm */ 4860 pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src, 4861 &conn->hcon->dst, LE_LINK); 4862 if (!pchan) { 4863 result = L2CAP_CR_LE_BAD_PSM; 4864 chan = NULL; 4865 goto response; 4866 } 4867 4868 mutex_lock(&conn->chan_lock); 4869 l2cap_chan_lock(pchan); 4870 4871 if (!smp_sufficient_security(conn->hcon, pchan->sec_level, 4872 SMP_ALLOW_STK)) { 4873 result = L2CAP_CR_LE_AUTHENTICATION; 4874 chan = NULL; 4875 goto response_unlock; 4876 } 4877 4878 /* Check for valid dynamic CID range */ 4879 if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_LE_DYN_END) { 4880 result = L2CAP_CR_LE_INVALID_SCID; 4881 chan = NULL; 4882 goto response_unlock; 4883 } 4884 4885 /* Check if we already have channel with that dcid */ 4886 if (__l2cap_get_chan_by_dcid(conn, scid)) { 4887 result = L2CAP_CR_LE_SCID_IN_USE; 4888 chan = NULL; 4889 goto response_unlock; 4890 } 4891 4892 chan = pchan->ops->new_connection(pchan); 4893 if (!chan) { 4894 result = L2CAP_CR_LE_NO_MEM; 4895 goto response_unlock; 4896 } 4897 4898 bacpy(&chan->src, &conn->hcon->src); 4899 bacpy(&chan->dst, &conn->hcon->dst); 4900 chan->src_type = bdaddr_src_type(conn->hcon); 4901 chan->dst_type = bdaddr_dst_type(conn->hcon); 4902 chan->psm = psm; 4903 chan->dcid = scid; 4904 chan->omtu = mtu; 4905 chan->remote_mps = mps; 4906 4907 __l2cap_chan_add(conn, chan); 4908 4909 l2cap_le_flowctl_init(chan, __le16_to_cpu(req->credits)); 4910 4911 dcid = chan->scid; 4912 credits = chan->rx_credits; 4913 4914 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan)); 4915 4916 chan->ident = cmd->ident; 4917 4918 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) { 4919 l2cap_state_change(chan, BT_CONNECT2); 4920 /* The following result value is actually not defined 4921 * for LE CoC but we use it to let the function know 4922 * that it should bail out after doing its cleanup 4923 * instead of sending a response. 4924 */ 4925 result = L2CAP_CR_PEND; 4926 chan->ops->defer(chan); 4927 } else { 4928 l2cap_chan_ready(chan); 4929 result = L2CAP_CR_LE_SUCCESS; 4930 } 4931 4932 response_unlock: 4933 l2cap_chan_unlock(pchan); 4934 mutex_unlock(&conn->chan_lock); 4935 l2cap_chan_put(pchan); 4936 4937 if (result == L2CAP_CR_PEND) 4938 return 0; 4939 4940 response: 4941 if (chan) { 4942 rsp.mtu = cpu_to_le16(chan->imtu); 4943 rsp.mps = cpu_to_le16(chan->mps); 4944 } else { 4945 rsp.mtu = 0; 4946 rsp.mps = 0; 4947 } 4948 4949 rsp.dcid = cpu_to_le16(dcid); 4950 rsp.credits = cpu_to_le16(credits); 4951 rsp.result = cpu_to_le16(result); 4952 4953 l2cap_send_cmd(conn, cmd->ident, L2CAP_LE_CONN_RSP, sizeof(rsp), &rsp); 4954 4955 return 0; 4956 } 4957 4958 static inline int l2cap_le_credits(struct l2cap_conn *conn, 4959 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4960 u8 *data) 4961 { 4962 struct l2cap_le_credits *pkt; 4963 struct l2cap_chan *chan; 4964 u16 cid, credits, max_credits; 4965 4966 if (cmd_len != sizeof(*pkt)) 4967 return -EPROTO; 4968 4969 pkt = (struct l2cap_le_credits *) data; 4970 cid = __le16_to_cpu(pkt->cid); 4971 credits = __le16_to_cpu(pkt->credits); 4972 4973 BT_DBG("cid 0x%4.4x credits 0x%4.4x", cid, credits); 4974 4975 chan = l2cap_get_chan_by_dcid(conn, cid); 4976 if (!chan) 4977 return -EBADSLT; 4978 4979 max_credits = LE_FLOWCTL_MAX_CREDITS - chan->tx_credits; 4980 if (credits > max_credits) { 4981 BT_ERR("LE credits overflow"); 4982 l2cap_send_disconn_req(chan, ECONNRESET); 4983 4984 /* Return 0 so that we don't trigger an unnecessary 4985 * command reject packet. 4986 */ 4987 goto unlock; 4988 } 4989 4990 chan->tx_credits += credits; 4991 4992 /* Resume sending */ 4993 l2cap_le_flowctl_send(chan); 4994 4995 if (chan->tx_credits) 4996 chan->ops->resume(chan); 4997 4998 unlock: 4999 l2cap_chan_unlock(chan); 5000 l2cap_chan_put(chan); 5001 5002 return 0; 5003 } 5004 5005 static inline int l2cap_ecred_conn_req(struct l2cap_conn *conn, 5006 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 5007 u8 *data) 5008 { 5009 struct l2cap_ecred_conn_req *req = (void *) data; 5010 DEFINE_RAW_FLEX(struct l2cap_ecred_conn_rsp, pdu, dcid, L2CAP_ECRED_MAX_CID); 5011 struct l2cap_chan *chan, *pchan; 5012 u16 mtu, mps; 5013 __le16 psm; 5014 u8 result, len = 0; 5015 int i, num_scid; 5016 bool defer = false; 5017 5018 if (!enable_ecred) 5019 return -EINVAL; 5020 5021 if (cmd_len < sizeof(*req) || (cmd_len - sizeof(*req)) % sizeof(u16)) { 5022 result = L2CAP_CR_LE_INVALID_PARAMS; 5023 goto response; 5024 } 5025 5026 cmd_len -= sizeof(*req); 5027 num_scid = cmd_len / sizeof(u16); 5028 5029 if (num_scid > L2CAP_ECRED_MAX_CID) { 5030 result = L2CAP_CR_LE_INVALID_PARAMS; 5031 goto response; 5032 } 5033 5034 mtu = __le16_to_cpu(req->mtu); 5035 mps = __le16_to_cpu(req->mps); 5036 5037 if (mtu < L2CAP_ECRED_MIN_MTU || mps < L2CAP_ECRED_MIN_MPS) { 5038 result = L2CAP_CR_LE_UNACCEPT_PARAMS; 5039 goto response; 5040 } 5041 5042 psm = req->psm; 5043 5044 /* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A 5045 * page 1059: 5046 * 5047 * Valid range: 0x0001-0x00ff 5048 * 5049 * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges 5050 */ 5051 if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) { 5052 result = L2CAP_CR_LE_BAD_PSM; 5053 goto response; 5054 } 5055 5056 BT_DBG("psm 0x%2.2x mtu %u mps %u", __le16_to_cpu(psm), mtu, mps); 5057 5058 memset(pdu, 0, sizeof(*pdu)); 5059 5060 /* Check if we have socket listening on psm */ 5061 pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src, 5062 &conn->hcon->dst, LE_LINK); 5063 if (!pchan) { 5064 result = L2CAP_CR_LE_BAD_PSM; 5065 goto response; 5066 } 5067 5068 mutex_lock(&conn->chan_lock); 5069 l2cap_chan_lock(pchan); 5070 5071 if (!smp_sufficient_security(conn->hcon, pchan->sec_level, 5072 SMP_ALLOW_STK)) { 5073 result = L2CAP_CR_LE_AUTHENTICATION; 5074 goto unlock; 5075 } 5076 5077 result = L2CAP_CR_LE_SUCCESS; 5078 5079 for (i = 0; i < num_scid; i++) { 5080 u16 scid = __le16_to_cpu(req->scid[i]); 5081 5082 BT_DBG("scid[%d] 0x%4.4x", i, scid); 5083 5084 pdu->dcid[i] = 0x0000; 5085 len += sizeof(*pdu->dcid); 5086 5087 /* Check for valid dynamic CID range */ 5088 if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_LE_DYN_END) { 5089 result = L2CAP_CR_LE_INVALID_SCID; 5090 continue; 5091 } 5092 5093 /* Check if we already have channel with that dcid */ 5094 if (__l2cap_get_chan_by_dcid(conn, scid)) { 5095 result = L2CAP_CR_LE_SCID_IN_USE; 5096 continue; 5097 } 5098 5099 chan = pchan->ops->new_connection(pchan); 5100 if (!chan) { 5101 result = L2CAP_CR_LE_NO_MEM; 5102 continue; 5103 } 5104 5105 bacpy(&chan->src, &conn->hcon->src); 5106 bacpy(&chan->dst, &conn->hcon->dst); 5107 chan->src_type = bdaddr_src_type(conn->hcon); 5108 chan->dst_type = bdaddr_dst_type(conn->hcon); 5109 chan->psm = psm; 5110 chan->dcid = scid; 5111 chan->omtu = mtu; 5112 chan->remote_mps = mps; 5113 5114 __l2cap_chan_add(conn, chan); 5115 5116 l2cap_ecred_init(chan, __le16_to_cpu(req->credits)); 5117 5118 /* Init response */ 5119 if (!pdu->credits) { 5120 pdu->mtu = cpu_to_le16(chan->imtu); 5121 pdu->mps = cpu_to_le16(chan->mps); 5122 pdu->credits = cpu_to_le16(chan->rx_credits); 5123 } 5124 5125 pdu->dcid[i] = cpu_to_le16(chan->scid); 5126 5127 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan)); 5128 5129 chan->ident = cmd->ident; 5130 chan->mode = L2CAP_MODE_EXT_FLOWCTL; 5131 5132 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) { 5133 l2cap_state_change(chan, BT_CONNECT2); 5134 defer = true; 5135 chan->ops->defer(chan); 5136 } else { 5137 l2cap_chan_ready(chan); 5138 } 5139 } 5140 5141 unlock: 5142 l2cap_chan_unlock(pchan); 5143 mutex_unlock(&conn->chan_lock); 5144 l2cap_chan_put(pchan); 5145 5146 response: 5147 pdu->result = cpu_to_le16(result); 5148 5149 if (defer) 5150 return 0; 5151 5152 l2cap_send_cmd(conn, cmd->ident, L2CAP_ECRED_CONN_RSP, 5153 sizeof(*pdu) + len, pdu); 5154 5155 return 0; 5156 } 5157 5158 static inline int l2cap_ecred_conn_rsp(struct l2cap_conn *conn, 5159 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 5160 u8 *data) 5161 { 5162 struct l2cap_ecred_conn_rsp *rsp = (void *) data; 5163 struct hci_conn *hcon = conn->hcon; 5164 u16 mtu, mps, credits, result; 5165 struct l2cap_chan *chan, *tmp; 5166 int err = 0, sec_level; 5167 int i = 0; 5168 5169 if (cmd_len < sizeof(*rsp)) 5170 return -EPROTO; 5171 5172 mtu = __le16_to_cpu(rsp->mtu); 5173 mps = __le16_to_cpu(rsp->mps); 5174 credits = __le16_to_cpu(rsp->credits); 5175 result = __le16_to_cpu(rsp->result); 5176 5177 BT_DBG("mtu %u mps %u credits %u result 0x%4.4x", mtu, mps, credits, 5178 result); 5179 5180 mutex_lock(&conn->chan_lock); 5181 5182 cmd_len -= sizeof(*rsp); 5183 5184 list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) { 5185 u16 dcid; 5186 5187 if (chan->ident != cmd->ident || 5188 chan->mode != L2CAP_MODE_EXT_FLOWCTL || 5189 chan->state == BT_CONNECTED) 5190 continue; 5191 5192 l2cap_chan_lock(chan); 5193 5194 /* Check that there is a dcid for each pending channel */ 5195 if (cmd_len < sizeof(dcid)) { 5196 l2cap_chan_del(chan, ECONNREFUSED); 5197 l2cap_chan_unlock(chan); 5198 continue; 5199 } 5200 5201 dcid = __le16_to_cpu(rsp->dcid[i++]); 5202 cmd_len -= sizeof(u16); 5203 5204 BT_DBG("dcid[%d] 0x%4.4x", i, dcid); 5205 5206 /* Check if dcid is already in use */ 5207 if (dcid && __l2cap_get_chan_by_dcid(conn, dcid)) { 5208 /* If a device receives a 5209 * L2CAP_CREDIT_BASED_CONNECTION_RSP packet with an 5210 * already-assigned Destination CID, then both the 5211 * original channel and the new channel shall be 5212 * immediately discarded and not used. 5213 */ 5214 l2cap_chan_del(chan, ECONNREFUSED); 5215 l2cap_chan_unlock(chan); 5216 chan = __l2cap_get_chan_by_dcid(conn, dcid); 5217 l2cap_chan_lock(chan); 5218 l2cap_chan_del(chan, ECONNRESET); 5219 l2cap_chan_unlock(chan); 5220 continue; 5221 } 5222 5223 switch (result) { 5224 case L2CAP_CR_LE_AUTHENTICATION: 5225 case L2CAP_CR_LE_ENCRYPTION: 5226 /* If we already have MITM protection we can't do 5227 * anything. 5228 */ 5229 if (hcon->sec_level > BT_SECURITY_MEDIUM) { 5230 l2cap_chan_del(chan, ECONNREFUSED); 5231 break; 5232 } 5233 5234 sec_level = hcon->sec_level + 1; 5235 if (chan->sec_level < sec_level) 5236 chan->sec_level = sec_level; 5237 5238 /* We'll need to send a new Connect Request */ 5239 clear_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags); 5240 5241 smp_conn_security(hcon, chan->sec_level); 5242 break; 5243 5244 case L2CAP_CR_LE_BAD_PSM: 5245 l2cap_chan_del(chan, ECONNREFUSED); 5246 break; 5247 5248 default: 5249 /* If dcid was not set it means channels was refused */ 5250 if (!dcid) { 5251 l2cap_chan_del(chan, ECONNREFUSED); 5252 break; 5253 } 5254 5255 chan->ident = 0; 5256 chan->dcid = dcid; 5257 chan->omtu = mtu; 5258 chan->remote_mps = mps; 5259 chan->tx_credits = credits; 5260 l2cap_chan_ready(chan); 5261 break; 5262 } 5263 5264 l2cap_chan_unlock(chan); 5265 } 5266 5267 mutex_unlock(&conn->chan_lock); 5268 5269 return err; 5270 } 5271 5272 static inline int l2cap_ecred_reconf_req(struct l2cap_conn *conn, 5273 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 5274 u8 *data) 5275 { 5276 struct l2cap_ecred_reconf_req *req = (void *) data; 5277 struct l2cap_ecred_reconf_rsp rsp; 5278 u16 mtu, mps, result; 5279 struct l2cap_chan *chan; 5280 int i, num_scid; 5281 5282 if (!enable_ecred) 5283 return -EINVAL; 5284 5285 if (cmd_len < sizeof(*req) || cmd_len - sizeof(*req) % sizeof(u16)) { 5286 result = L2CAP_CR_LE_INVALID_PARAMS; 5287 goto respond; 5288 } 5289 5290 mtu = __le16_to_cpu(req->mtu); 5291 mps = __le16_to_cpu(req->mps); 5292 5293 BT_DBG("mtu %u mps %u", mtu, mps); 5294 5295 if (mtu < L2CAP_ECRED_MIN_MTU) { 5296 result = L2CAP_RECONF_INVALID_MTU; 5297 goto respond; 5298 } 5299 5300 if (mps < L2CAP_ECRED_MIN_MPS) { 5301 result = L2CAP_RECONF_INVALID_MPS; 5302 goto respond; 5303 } 5304 5305 cmd_len -= sizeof(*req); 5306 num_scid = cmd_len / sizeof(u16); 5307 result = L2CAP_RECONF_SUCCESS; 5308 5309 for (i = 0; i < num_scid; i++) { 5310 u16 scid; 5311 5312 scid = __le16_to_cpu(req->scid[i]); 5313 if (!scid) 5314 return -EPROTO; 5315 5316 chan = __l2cap_get_chan_by_dcid(conn, scid); 5317 if (!chan) 5318 continue; 5319 5320 /* If the MTU value is decreased for any of the included 5321 * channels, then the receiver shall disconnect all 5322 * included channels. 5323 */ 5324 if (chan->omtu > mtu) { 5325 BT_ERR("chan %p decreased MTU %u -> %u", chan, 5326 chan->omtu, mtu); 5327 result = L2CAP_RECONF_INVALID_MTU; 5328 } 5329 5330 chan->omtu = mtu; 5331 chan->remote_mps = mps; 5332 } 5333 5334 respond: 5335 rsp.result = cpu_to_le16(result); 5336 5337 l2cap_send_cmd(conn, cmd->ident, L2CAP_ECRED_RECONF_RSP, sizeof(rsp), 5338 &rsp); 5339 5340 return 0; 5341 } 5342 5343 static inline int l2cap_ecred_reconf_rsp(struct l2cap_conn *conn, 5344 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 5345 u8 *data) 5346 { 5347 struct l2cap_chan *chan, *tmp; 5348 struct l2cap_ecred_conn_rsp *rsp = (void *) data; 5349 u16 result; 5350 5351 if (cmd_len < sizeof(*rsp)) 5352 return -EPROTO; 5353 5354 result = __le16_to_cpu(rsp->result); 5355 5356 BT_DBG("result 0x%4.4x", rsp->result); 5357 5358 if (!result) 5359 return 0; 5360 5361 list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) { 5362 if (chan->ident != cmd->ident) 5363 continue; 5364 5365 l2cap_chan_del(chan, ECONNRESET); 5366 } 5367 5368 return 0; 5369 } 5370 5371 static inline int l2cap_le_command_rej(struct l2cap_conn *conn, 5372 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 5373 u8 *data) 5374 { 5375 struct l2cap_cmd_rej_unk *rej = (struct l2cap_cmd_rej_unk *) data; 5376 struct l2cap_chan *chan; 5377 5378 if (cmd_len < sizeof(*rej)) 5379 return -EPROTO; 5380 5381 mutex_lock(&conn->chan_lock); 5382 5383 chan = __l2cap_get_chan_by_ident(conn, cmd->ident); 5384 if (!chan) 5385 goto done; 5386 5387 chan = l2cap_chan_hold_unless_zero(chan); 5388 if (!chan) 5389 goto done; 5390 5391 l2cap_chan_lock(chan); 5392 l2cap_chan_del(chan, ECONNREFUSED); 5393 l2cap_chan_unlock(chan); 5394 l2cap_chan_put(chan); 5395 5396 done: 5397 mutex_unlock(&conn->chan_lock); 5398 return 0; 5399 } 5400 5401 static inline int l2cap_le_sig_cmd(struct l2cap_conn *conn, 5402 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 5403 u8 *data) 5404 { 5405 int err = 0; 5406 5407 switch (cmd->code) { 5408 case L2CAP_COMMAND_REJ: 5409 l2cap_le_command_rej(conn, cmd, cmd_len, data); 5410 break; 5411 5412 case L2CAP_CONN_PARAM_UPDATE_REQ: 5413 err = l2cap_conn_param_update_req(conn, cmd, cmd_len, data); 5414 break; 5415 5416 case L2CAP_CONN_PARAM_UPDATE_RSP: 5417 break; 5418 5419 case L2CAP_LE_CONN_RSP: 5420 l2cap_le_connect_rsp(conn, cmd, cmd_len, data); 5421 break; 5422 5423 case L2CAP_LE_CONN_REQ: 5424 err = l2cap_le_connect_req(conn, cmd, cmd_len, data); 5425 break; 5426 5427 case L2CAP_LE_CREDITS: 5428 err = l2cap_le_credits(conn, cmd, cmd_len, data); 5429 break; 5430 5431 case L2CAP_ECRED_CONN_REQ: 5432 err = l2cap_ecred_conn_req(conn, cmd, cmd_len, data); 5433 break; 5434 5435 case L2CAP_ECRED_CONN_RSP: 5436 err = l2cap_ecred_conn_rsp(conn, cmd, cmd_len, data); 5437 break; 5438 5439 case L2CAP_ECRED_RECONF_REQ: 5440 err = l2cap_ecred_reconf_req(conn, cmd, cmd_len, data); 5441 break; 5442 5443 case L2CAP_ECRED_RECONF_RSP: 5444 err = l2cap_ecred_reconf_rsp(conn, cmd, cmd_len, data); 5445 break; 5446 5447 case L2CAP_DISCONN_REQ: 5448 err = l2cap_disconnect_req(conn, cmd, cmd_len, data); 5449 break; 5450 5451 case L2CAP_DISCONN_RSP: 5452 l2cap_disconnect_rsp(conn, cmd, cmd_len, data); 5453 break; 5454 5455 default: 5456 BT_ERR("Unknown LE signaling command 0x%2.2x", cmd->code); 5457 err = -EINVAL; 5458 break; 5459 } 5460 5461 return err; 5462 } 5463 5464 static inline void l2cap_le_sig_channel(struct l2cap_conn *conn, 5465 struct sk_buff *skb) 5466 { 5467 struct hci_conn *hcon = conn->hcon; 5468 struct l2cap_cmd_hdr *cmd; 5469 u16 len; 5470 int err; 5471 5472 if (hcon->type != LE_LINK) 5473 goto drop; 5474 5475 if (skb->len < L2CAP_CMD_HDR_SIZE) 5476 goto drop; 5477 5478 cmd = (void *) skb->data; 5479 skb_pull(skb, L2CAP_CMD_HDR_SIZE); 5480 5481 len = le16_to_cpu(cmd->len); 5482 5483 BT_DBG("code 0x%2.2x len %d id 0x%2.2x", cmd->code, len, cmd->ident); 5484 5485 if (len != skb->len || !cmd->ident) { 5486 BT_DBG("corrupted command"); 5487 goto drop; 5488 } 5489 5490 err = l2cap_le_sig_cmd(conn, cmd, len, skb->data); 5491 if (err) { 5492 struct l2cap_cmd_rej_unk rej; 5493 5494 BT_ERR("Wrong link type (%d)", err); 5495 5496 rej.reason = cpu_to_le16(L2CAP_REJ_NOT_UNDERSTOOD); 5497 l2cap_send_cmd(conn, cmd->ident, L2CAP_COMMAND_REJ, 5498 sizeof(rej), &rej); 5499 } 5500 5501 drop: 5502 kfree_skb(skb); 5503 } 5504 5505 static inline void l2cap_sig_send_rej(struct l2cap_conn *conn, u16 ident) 5506 { 5507 struct l2cap_cmd_rej_unk rej; 5508 5509 rej.reason = cpu_to_le16(L2CAP_REJ_NOT_UNDERSTOOD); 5510 l2cap_send_cmd(conn, ident, L2CAP_COMMAND_REJ, sizeof(rej), &rej); 5511 } 5512 5513 static inline void l2cap_sig_channel(struct l2cap_conn *conn, 5514 struct sk_buff *skb) 5515 { 5516 struct hci_conn *hcon = conn->hcon; 5517 struct l2cap_cmd_hdr *cmd; 5518 int err; 5519 5520 l2cap_raw_recv(conn, skb); 5521 5522 if (hcon->type != ACL_LINK) 5523 goto drop; 5524 5525 while (skb->len >= L2CAP_CMD_HDR_SIZE) { 5526 u16 len; 5527 5528 cmd = (void *) skb->data; 5529 skb_pull(skb, L2CAP_CMD_HDR_SIZE); 5530 5531 len = le16_to_cpu(cmd->len); 5532 5533 BT_DBG("code 0x%2.2x len %d id 0x%2.2x", cmd->code, len, 5534 cmd->ident); 5535 5536 if (len > skb->len || !cmd->ident) { 5537 BT_DBG("corrupted command"); 5538 l2cap_sig_send_rej(conn, cmd->ident); 5539 skb_pull(skb, len > skb->len ? skb->len : len); 5540 continue; 5541 } 5542 5543 err = l2cap_bredr_sig_cmd(conn, cmd, len, skb->data); 5544 if (err) { 5545 BT_ERR("Wrong link type (%d)", err); 5546 l2cap_sig_send_rej(conn, cmd->ident); 5547 } 5548 5549 skb_pull(skb, len); 5550 } 5551 5552 if (skb->len > 0) { 5553 BT_DBG("corrupted command"); 5554 l2cap_sig_send_rej(conn, 0); 5555 } 5556 5557 drop: 5558 kfree_skb(skb); 5559 } 5560 5561 static int l2cap_check_fcs(struct l2cap_chan *chan, struct sk_buff *skb) 5562 { 5563 u16 our_fcs, rcv_fcs; 5564 int hdr_size; 5565 5566 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) 5567 hdr_size = L2CAP_EXT_HDR_SIZE; 5568 else 5569 hdr_size = L2CAP_ENH_HDR_SIZE; 5570 5571 if (chan->fcs == L2CAP_FCS_CRC16) { 5572 skb_trim(skb, skb->len - L2CAP_FCS_SIZE); 5573 rcv_fcs = get_unaligned_le16(skb->data + skb->len); 5574 our_fcs = crc16(0, skb->data - hdr_size, skb->len + hdr_size); 5575 5576 if (our_fcs != rcv_fcs) 5577 return -EBADMSG; 5578 } 5579 return 0; 5580 } 5581 5582 static void l2cap_send_i_or_rr_or_rnr(struct l2cap_chan *chan) 5583 { 5584 struct l2cap_ctrl control; 5585 5586 BT_DBG("chan %p", chan); 5587 5588 memset(&control, 0, sizeof(control)); 5589 control.sframe = 1; 5590 control.final = 1; 5591 control.reqseq = chan->buffer_seq; 5592 set_bit(CONN_SEND_FBIT, &chan->conn_state); 5593 5594 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) { 5595 control.super = L2CAP_SUPER_RNR; 5596 l2cap_send_sframe(chan, &control); 5597 } 5598 5599 if (test_and_clear_bit(CONN_REMOTE_BUSY, &chan->conn_state) && 5600 chan->unacked_frames > 0) 5601 __set_retrans_timer(chan); 5602 5603 /* Send pending iframes */ 5604 l2cap_ertm_send(chan); 5605 5606 if (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state) && 5607 test_bit(CONN_SEND_FBIT, &chan->conn_state)) { 5608 /* F-bit wasn't sent in an s-frame or i-frame yet, so 5609 * send it now. 5610 */ 5611 control.super = L2CAP_SUPER_RR; 5612 l2cap_send_sframe(chan, &control); 5613 } 5614 } 5615 5616 static void append_skb_frag(struct sk_buff *skb, struct sk_buff *new_frag, 5617 struct sk_buff **last_frag) 5618 { 5619 /* skb->len reflects data in skb as well as all fragments 5620 * skb->data_len reflects only data in fragments 5621 */ 5622 if (!skb_has_frag_list(skb)) 5623 skb_shinfo(skb)->frag_list = new_frag; 5624 5625 new_frag->next = NULL; 5626 5627 (*last_frag)->next = new_frag; 5628 *last_frag = new_frag; 5629 5630 skb->len += new_frag->len; 5631 skb->data_len += new_frag->len; 5632 skb->truesize += new_frag->truesize; 5633 } 5634 5635 static int l2cap_reassemble_sdu(struct l2cap_chan *chan, struct sk_buff *skb, 5636 struct l2cap_ctrl *control) 5637 { 5638 int err = -EINVAL; 5639 5640 switch (control->sar) { 5641 case L2CAP_SAR_UNSEGMENTED: 5642 if (chan->sdu) 5643 break; 5644 5645 err = chan->ops->recv(chan, skb); 5646 break; 5647 5648 case L2CAP_SAR_START: 5649 if (chan->sdu) 5650 break; 5651 5652 if (!pskb_may_pull(skb, L2CAP_SDULEN_SIZE)) 5653 break; 5654 5655 chan->sdu_len = get_unaligned_le16(skb->data); 5656 skb_pull(skb, L2CAP_SDULEN_SIZE); 5657 5658 if (chan->sdu_len > chan->imtu) { 5659 err = -EMSGSIZE; 5660 break; 5661 } 5662 5663 if (skb->len >= chan->sdu_len) 5664 break; 5665 5666 chan->sdu = skb; 5667 chan->sdu_last_frag = skb; 5668 5669 skb = NULL; 5670 err = 0; 5671 break; 5672 5673 case L2CAP_SAR_CONTINUE: 5674 if (!chan->sdu) 5675 break; 5676 5677 append_skb_frag(chan->sdu, skb, 5678 &chan->sdu_last_frag); 5679 skb = NULL; 5680 5681 if (chan->sdu->len >= chan->sdu_len) 5682 break; 5683 5684 err = 0; 5685 break; 5686 5687 case L2CAP_SAR_END: 5688 if (!chan->sdu) 5689 break; 5690 5691 append_skb_frag(chan->sdu, skb, 5692 &chan->sdu_last_frag); 5693 skb = NULL; 5694 5695 if (chan->sdu->len != chan->sdu_len) 5696 break; 5697 5698 err = chan->ops->recv(chan, chan->sdu); 5699 5700 if (!err) { 5701 /* Reassembly complete */ 5702 chan->sdu = NULL; 5703 chan->sdu_last_frag = NULL; 5704 chan->sdu_len = 0; 5705 } 5706 break; 5707 } 5708 5709 if (err) { 5710 kfree_skb(skb); 5711 kfree_skb(chan->sdu); 5712 chan->sdu = NULL; 5713 chan->sdu_last_frag = NULL; 5714 chan->sdu_len = 0; 5715 } 5716 5717 return err; 5718 } 5719 5720 static int l2cap_resegment(struct l2cap_chan *chan) 5721 { 5722 /* Placeholder */ 5723 return 0; 5724 } 5725 5726 void l2cap_chan_busy(struct l2cap_chan *chan, int busy) 5727 { 5728 u8 event; 5729 5730 if (chan->mode != L2CAP_MODE_ERTM) 5731 return; 5732 5733 event = busy ? L2CAP_EV_LOCAL_BUSY_DETECTED : L2CAP_EV_LOCAL_BUSY_CLEAR; 5734 l2cap_tx(chan, NULL, NULL, event); 5735 } 5736 5737 static int l2cap_rx_queued_iframes(struct l2cap_chan *chan) 5738 { 5739 int err = 0; 5740 /* Pass sequential frames to l2cap_reassemble_sdu() 5741 * until a gap is encountered. 5742 */ 5743 5744 BT_DBG("chan %p", chan); 5745 5746 while (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) { 5747 struct sk_buff *skb; 5748 BT_DBG("Searching for skb with txseq %d (queue len %d)", 5749 chan->buffer_seq, skb_queue_len(&chan->srej_q)); 5750 5751 skb = l2cap_ertm_seq_in_queue(&chan->srej_q, chan->buffer_seq); 5752 5753 if (!skb) 5754 break; 5755 5756 skb_unlink(skb, &chan->srej_q); 5757 chan->buffer_seq = __next_seq(chan, chan->buffer_seq); 5758 err = l2cap_reassemble_sdu(chan, skb, &bt_cb(skb)->l2cap); 5759 if (err) 5760 break; 5761 } 5762 5763 if (skb_queue_empty(&chan->srej_q)) { 5764 chan->rx_state = L2CAP_RX_STATE_RECV; 5765 l2cap_send_ack(chan); 5766 } 5767 5768 return err; 5769 } 5770 5771 static void l2cap_handle_srej(struct l2cap_chan *chan, 5772 struct l2cap_ctrl *control) 5773 { 5774 struct sk_buff *skb; 5775 5776 BT_DBG("chan %p, control %p", chan, control); 5777 5778 if (control->reqseq == chan->next_tx_seq) { 5779 BT_DBG("Invalid reqseq %d, disconnecting", control->reqseq); 5780 l2cap_send_disconn_req(chan, ECONNRESET); 5781 return; 5782 } 5783 5784 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, control->reqseq); 5785 5786 if (skb == NULL) { 5787 BT_DBG("Seq %d not available for retransmission", 5788 control->reqseq); 5789 return; 5790 } 5791 5792 if (chan->max_tx != 0 && bt_cb(skb)->l2cap.retries >= chan->max_tx) { 5793 BT_DBG("Retry limit exceeded (%d)", chan->max_tx); 5794 l2cap_send_disconn_req(chan, ECONNRESET); 5795 return; 5796 } 5797 5798 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state); 5799 5800 if (control->poll) { 5801 l2cap_pass_to_tx(chan, control); 5802 5803 set_bit(CONN_SEND_FBIT, &chan->conn_state); 5804 l2cap_retransmit(chan, control); 5805 l2cap_ertm_send(chan); 5806 5807 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F) { 5808 set_bit(CONN_SREJ_ACT, &chan->conn_state); 5809 chan->srej_save_reqseq = control->reqseq; 5810 } 5811 } else { 5812 l2cap_pass_to_tx_fbit(chan, control); 5813 5814 if (control->final) { 5815 if (chan->srej_save_reqseq != control->reqseq || 5816 !test_and_clear_bit(CONN_SREJ_ACT, 5817 &chan->conn_state)) 5818 l2cap_retransmit(chan, control); 5819 } else { 5820 l2cap_retransmit(chan, control); 5821 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F) { 5822 set_bit(CONN_SREJ_ACT, &chan->conn_state); 5823 chan->srej_save_reqseq = control->reqseq; 5824 } 5825 } 5826 } 5827 } 5828 5829 static void l2cap_handle_rej(struct l2cap_chan *chan, 5830 struct l2cap_ctrl *control) 5831 { 5832 struct sk_buff *skb; 5833 5834 BT_DBG("chan %p, control %p", chan, control); 5835 5836 if (control->reqseq == chan->next_tx_seq) { 5837 BT_DBG("Invalid reqseq %d, disconnecting", control->reqseq); 5838 l2cap_send_disconn_req(chan, ECONNRESET); 5839 return; 5840 } 5841 5842 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, control->reqseq); 5843 5844 if (chan->max_tx && skb && 5845 bt_cb(skb)->l2cap.retries >= chan->max_tx) { 5846 BT_DBG("Retry limit exceeded (%d)", chan->max_tx); 5847 l2cap_send_disconn_req(chan, ECONNRESET); 5848 return; 5849 } 5850 5851 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state); 5852 5853 l2cap_pass_to_tx(chan, control); 5854 5855 if (control->final) { 5856 if (!test_and_clear_bit(CONN_REJ_ACT, &chan->conn_state)) 5857 l2cap_retransmit_all(chan, control); 5858 } else { 5859 l2cap_retransmit_all(chan, control); 5860 l2cap_ertm_send(chan); 5861 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F) 5862 set_bit(CONN_REJ_ACT, &chan->conn_state); 5863 } 5864 } 5865 5866 static u8 l2cap_classify_txseq(struct l2cap_chan *chan, u16 txseq) 5867 { 5868 BT_DBG("chan %p, txseq %d", chan, txseq); 5869 5870 BT_DBG("last_acked_seq %d, expected_tx_seq %d", chan->last_acked_seq, 5871 chan->expected_tx_seq); 5872 5873 if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) { 5874 if (__seq_offset(chan, txseq, chan->last_acked_seq) >= 5875 chan->tx_win) { 5876 /* See notes below regarding "double poll" and 5877 * invalid packets. 5878 */ 5879 if (chan->tx_win <= ((chan->tx_win_max + 1) >> 1)) { 5880 BT_DBG("Invalid/Ignore - after SREJ"); 5881 return L2CAP_TXSEQ_INVALID_IGNORE; 5882 } else { 5883 BT_DBG("Invalid - in window after SREJ sent"); 5884 return L2CAP_TXSEQ_INVALID; 5885 } 5886 } 5887 5888 if (chan->srej_list.head == txseq) { 5889 BT_DBG("Expected SREJ"); 5890 return L2CAP_TXSEQ_EXPECTED_SREJ; 5891 } 5892 5893 if (l2cap_ertm_seq_in_queue(&chan->srej_q, txseq)) { 5894 BT_DBG("Duplicate SREJ - txseq already stored"); 5895 return L2CAP_TXSEQ_DUPLICATE_SREJ; 5896 } 5897 5898 if (l2cap_seq_list_contains(&chan->srej_list, txseq)) { 5899 BT_DBG("Unexpected SREJ - not requested"); 5900 return L2CAP_TXSEQ_UNEXPECTED_SREJ; 5901 } 5902 } 5903 5904 if (chan->expected_tx_seq == txseq) { 5905 if (__seq_offset(chan, txseq, chan->last_acked_seq) >= 5906 chan->tx_win) { 5907 BT_DBG("Invalid - txseq outside tx window"); 5908 return L2CAP_TXSEQ_INVALID; 5909 } else { 5910 BT_DBG("Expected"); 5911 return L2CAP_TXSEQ_EXPECTED; 5912 } 5913 } 5914 5915 if (__seq_offset(chan, txseq, chan->last_acked_seq) < 5916 __seq_offset(chan, chan->expected_tx_seq, chan->last_acked_seq)) { 5917 BT_DBG("Duplicate - expected_tx_seq later than txseq"); 5918 return L2CAP_TXSEQ_DUPLICATE; 5919 } 5920 5921 if (__seq_offset(chan, txseq, chan->last_acked_seq) >= chan->tx_win) { 5922 /* A source of invalid packets is a "double poll" condition, 5923 * where delays cause us to send multiple poll packets. If 5924 * the remote stack receives and processes both polls, 5925 * sequence numbers can wrap around in such a way that a 5926 * resent frame has a sequence number that looks like new data 5927 * with a sequence gap. This would trigger an erroneous SREJ 5928 * request. 5929 * 5930 * Fortunately, this is impossible with a tx window that's 5931 * less than half of the maximum sequence number, which allows 5932 * invalid frames to be safely ignored. 5933 * 5934 * With tx window sizes greater than half of the tx window 5935 * maximum, the frame is invalid and cannot be ignored. This 5936 * causes a disconnect. 5937 */ 5938 5939 if (chan->tx_win <= ((chan->tx_win_max + 1) >> 1)) { 5940 BT_DBG("Invalid/Ignore - txseq outside tx window"); 5941 return L2CAP_TXSEQ_INVALID_IGNORE; 5942 } else { 5943 BT_DBG("Invalid - txseq outside tx window"); 5944 return L2CAP_TXSEQ_INVALID; 5945 } 5946 } else { 5947 BT_DBG("Unexpected - txseq indicates missing frames"); 5948 return L2CAP_TXSEQ_UNEXPECTED; 5949 } 5950 } 5951 5952 static int l2cap_rx_state_recv(struct l2cap_chan *chan, 5953 struct l2cap_ctrl *control, 5954 struct sk_buff *skb, u8 event) 5955 { 5956 struct l2cap_ctrl local_control; 5957 int err = 0; 5958 bool skb_in_use = false; 5959 5960 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb, 5961 event); 5962 5963 switch (event) { 5964 case L2CAP_EV_RECV_IFRAME: 5965 switch (l2cap_classify_txseq(chan, control->txseq)) { 5966 case L2CAP_TXSEQ_EXPECTED: 5967 l2cap_pass_to_tx(chan, control); 5968 5969 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) { 5970 BT_DBG("Busy, discarding expected seq %d", 5971 control->txseq); 5972 break; 5973 } 5974 5975 chan->expected_tx_seq = __next_seq(chan, 5976 control->txseq); 5977 5978 chan->buffer_seq = chan->expected_tx_seq; 5979 skb_in_use = true; 5980 5981 /* l2cap_reassemble_sdu may free skb, hence invalidate 5982 * control, so make a copy in advance to use it after 5983 * l2cap_reassemble_sdu returns and to avoid the race 5984 * condition, for example: 5985 * 5986 * The current thread calls: 5987 * l2cap_reassemble_sdu 5988 * chan->ops->recv == l2cap_sock_recv_cb 5989 * __sock_queue_rcv_skb 5990 * Another thread calls: 5991 * bt_sock_recvmsg 5992 * skb_recv_datagram 5993 * skb_free_datagram 5994 * Then the current thread tries to access control, but 5995 * it was freed by skb_free_datagram. 5996 */ 5997 local_control = *control; 5998 err = l2cap_reassemble_sdu(chan, skb, control); 5999 if (err) 6000 break; 6001 6002 if (local_control.final) { 6003 if (!test_and_clear_bit(CONN_REJ_ACT, 6004 &chan->conn_state)) { 6005 local_control.final = 0; 6006 l2cap_retransmit_all(chan, &local_control); 6007 l2cap_ertm_send(chan); 6008 } 6009 } 6010 6011 if (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) 6012 l2cap_send_ack(chan); 6013 break; 6014 case L2CAP_TXSEQ_UNEXPECTED: 6015 l2cap_pass_to_tx(chan, control); 6016 6017 /* Can't issue SREJ frames in the local busy state. 6018 * Drop this frame, it will be seen as missing 6019 * when local busy is exited. 6020 */ 6021 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) { 6022 BT_DBG("Busy, discarding unexpected seq %d", 6023 control->txseq); 6024 break; 6025 } 6026 6027 /* There was a gap in the sequence, so an SREJ 6028 * must be sent for each missing frame. The 6029 * current frame is stored for later use. 6030 */ 6031 skb_queue_tail(&chan->srej_q, skb); 6032 skb_in_use = true; 6033 BT_DBG("Queued %p (queue len %d)", skb, 6034 skb_queue_len(&chan->srej_q)); 6035 6036 clear_bit(CONN_SREJ_ACT, &chan->conn_state); 6037 l2cap_seq_list_clear(&chan->srej_list); 6038 l2cap_send_srej(chan, control->txseq); 6039 6040 chan->rx_state = L2CAP_RX_STATE_SREJ_SENT; 6041 break; 6042 case L2CAP_TXSEQ_DUPLICATE: 6043 l2cap_pass_to_tx(chan, control); 6044 break; 6045 case L2CAP_TXSEQ_INVALID_IGNORE: 6046 break; 6047 case L2CAP_TXSEQ_INVALID: 6048 default: 6049 l2cap_send_disconn_req(chan, ECONNRESET); 6050 break; 6051 } 6052 break; 6053 case L2CAP_EV_RECV_RR: 6054 l2cap_pass_to_tx(chan, control); 6055 if (control->final) { 6056 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state); 6057 6058 if (!test_and_clear_bit(CONN_REJ_ACT, 6059 &chan->conn_state)) { 6060 control->final = 0; 6061 l2cap_retransmit_all(chan, control); 6062 } 6063 6064 l2cap_ertm_send(chan); 6065 } else if (control->poll) { 6066 l2cap_send_i_or_rr_or_rnr(chan); 6067 } else { 6068 if (test_and_clear_bit(CONN_REMOTE_BUSY, 6069 &chan->conn_state) && 6070 chan->unacked_frames) 6071 __set_retrans_timer(chan); 6072 6073 l2cap_ertm_send(chan); 6074 } 6075 break; 6076 case L2CAP_EV_RECV_RNR: 6077 set_bit(CONN_REMOTE_BUSY, &chan->conn_state); 6078 l2cap_pass_to_tx(chan, control); 6079 if (control && control->poll) { 6080 set_bit(CONN_SEND_FBIT, &chan->conn_state); 6081 l2cap_send_rr_or_rnr(chan, 0); 6082 } 6083 __clear_retrans_timer(chan); 6084 l2cap_seq_list_clear(&chan->retrans_list); 6085 break; 6086 case L2CAP_EV_RECV_REJ: 6087 l2cap_handle_rej(chan, control); 6088 break; 6089 case L2CAP_EV_RECV_SREJ: 6090 l2cap_handle_srej(chan, control); 6091 break; 6092 default: 6093 break; 6094 } 6095 6096 if (skb && !skb_in_use) { 6097 BT_DBG("Freeing %p", skb); 6098 kfree_skb(skb); 6099 } 6100 6101 return err; 6102 } 6103 6104 static int l2cap_rx_state_srej_sent(struct l2cap_chan *chan, 6105 struct l2cap_ctrl *control, 6106 struct sk_buff *skb, u8 event) 6107 { 6108 int err = 0; 6109 u16 txseq = control->txseq; 6110 bool skb_in_use = false; 6111 6112 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb, 6113 event); 6114 6115 switch (event) { 6116 case L2CAP_EV_RECV_IFRAME: 6117 switch (l2cap_classify_txseq(chan, txseq)) { 6118 case L2CAP_TXSEQ_EXPECTED: 6119 /* Keep frame for reassembly later */ 6120 l2cap_pass_to_tx(chan, control); 6121 skb_queue_tail(&chan->srej_q, skb); 6122 skb_in_use = true; 6123 BT_DBG("Queued %p (queue len %d)", skb, 6124 skb_queue_len(&chan->srej_q)); 6125 6126 chan->expected_tx_seq = __next_seq(chan, txseq); 6127 break; 6128 case L2CAP_TXSEQ_EXPECTED_SREJ: 6129 l2cap_seq_list_pop(&chan->srej_list); 6130 6131 l2cap_pass_to_tx(chan, control); 6132 skb_queue_tail(&chan->srej_q, skb); 6133 skb_in_use = true; 6134 BT_DBG("Queued %p (queue len %d)", skb, 6135 skb_queue_len(&chan->srej_q)); 6136 6137 err = l2cap_rx_queued_iframes(chan); 6138 if (err) 6139 break; 6140 6141 break; 6142 case L2CAP_TXSEQ_UNEXPECTED: 6143 /* Got a frame that can't be reassembled yet. 6144 * Save it for later, and send SREJs to cover 6145 * the missing frames. 6146 */ 6147 skb_queue_tail(&chan->srej_q, skb); 6148 skb_in_use = true; 6149 BT_DBG("Queued %p (queue len %d)", skb, 6150 skb_queue_len(&chan->srej_q)); 6151 6152 l2cap_pass_to_tx(chan, control); 6153 l2cap_send_srej(chan, control->txseq); 6154 break; 6155 case L2CAP_TXSEQ_UNEXPECTED_SREJ: 6156 /* This frame was requested with an SREJ, but 6157 * some expected retransmitted frames are 6158 * missing. Request retransmission of missing 6159 * SREJ'd frames. 6160 */ 6161 skb_queue_tail(&chan->srej_q, skb); 6162 skb_in_use = true; 6163 BT_DBG("Queued %p (queue len %d)", skb, 6164 skb_queue_len(&chan->srej_q)); 6165 6166 l2cap_pass_to_tx(chan, control); 6167 l2cap_send_srej_list(chan, control->txseq); 6168 break; 6169 case L2CAP_TXSEQ_DUPLICATE_SREJ: 6170 /* We've already queued this frame. Drop this copy. */ 6171 l2cap_pass_to_tx(chan, control); 6172 break; 6173 case L2CAP_TXSEQ_DUPLICATE: 6174 /* Expecting a later sequence number, so this frame 6175 * was already received. Ignore it completely. 6176 */ 6177 break; 6178 case L2CAP_TXSEQ_INVALID_IGNORE: 6179 break; 6180 case L2CAP_TXSEQ_INVALID: 6181 default: 6182 l2cap_send_disconn_req(chan, ECONNRESET); 6183 break; 6184 } 6185 break; 6186 case L2CAP_EV_RECV_RR: 6187 l2cap_pass_to_tx(chan, control); 6188 if (control->final) { 6189 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state); 6190 6191 if (!test_and_clear_bit(CONN_REJ_ACT, 6192 &chan->conn_state)) { 6193 control->final = 0; 6194 l2cap_retransmit_all(chan, control); 6195 } 6196 6197 l2cap_ertm_send(chan); 6198 } else if (control->poll) { 6199 if (test_and_clear_bit(CONN_REMOTE_BUSY, 6200 &chan->conn_state) && 6201 chan->unacked_frames) { 6202 __set_retrans_timer(chan); 6203 } 6204 6205 set_bit(CONN_SEND_FBIT, &chan->conn_state); 6206 l2cap_send_srej_tail(chan); 6207 } else { 6208 if (test_and_clear_bit(CONN_REMOTE_BUSY, 6209 &chan->conn_state) && 6210 chan->unacked_frames) 6211 __set_retrans_timer(chan); 6212 6213 l2cap_send_ack(chan); 6214 } 6215 break; 6216 case L2CAP_EV_RECV_RNR: 6217 set_bit(CONN_REMOTE_BUSY, &chan->conn_state); 6218 l2cap_pass_to_tx(chan, control); 6219 if (control->poll) { 6220 l2cap_send_srej_tail(chan); 6221 } else { 6222 struct l2cap_ctrl rr_control; 6223 memset(&rr_control, 0, sizeof(rr_control)); 6224 rr_control.sframe = 1; 6225 rr_control.super = L2CAP_SUPER_RR; 6226 rr_control.reqseq = chan->buffer_seq; 6227 l2cap_send_sframe(chan, &rr_control); 6228 } 6229 6230 break; 6231 case L2CAP_EV_RECV_REJ: 6232 l2cap_handle_rej(chan, control); 6233 break; 6234 case L2CAP_EV_RECV_SREJ: 6235 l2cap_handle_srej(chan, control); 6236 break; 6237 } 6238 6239 if (skb && !skb_in_use) { 6240 BT_DBG("Freeing %p", skb); 6241 kfree_skb(skb); 6242 } 6243 6244 return err; 6245 } 6246 6247 static int l2cap_finish_move(struct l2cap_chan *chan) 6248 { 6249 BT_DBG("chan %p", chan); 6250 6251 chan->rx_state = L2CAP_RX_STATE_RECV; 6252 chan->conn->mtu = chan->conn->hcon->mtu; 6253 6254 return l2cap_resegment(chan); 6255 } 6256 6257 static int l2cap_rx_state_wait_p(struct l2cap_chan *chan, 6258 struct l2cap_ctrl *control, 6259 struct sk_buff *skb, u8 event) 6260 { 6261 int err; 6262 6263 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb, 6264 event); 6265 6266 if (!control->poll) 6267 return -EPROTO; 6268 6269 l2cap_process_reqseq(chan, control->reqseq); 6270 6271 if (!skb_queue_empty(&chan->tx_q)) 6272 chan->tx_send_head = skb_peek(&chan->tx_q); 6273 else 6274 chan->tx_send_head = NULL; 6275 6276 /* Rewind next_tx_seq to the point expected 6277 * by the receiver. 6278 */ 6279 chan->next_tx_seq = control->reqseq; 6280 chan->unacked_frames = 0; 6281 6282 err = l2cap_finish_move(chan); 6283 if (err) 6284 return err; 6285 6286 set_bit(CONN_SEND_FBIT, &chan->conn_state); 6287 l2cap_send_i_or_rr_or_rnr(chan); 6288 6289 if (event == L2CAP_EV_RECV_IFRAME) 6290 return -EPROTO; 6291 6292 return l2cap_rx_state_recv(chan, control, NULL, event); 6293 } 6294 6295 static int l2cap_rx_state_wait_f(struct l2cap_chan *chan, 6296 struct l2cap_ctrl *control, 6297 struct sk_buff *skb, u8 event) 6298 { 6299 int err; 6300 6301 if (!control->final) 6302 return -EPROTO; 6303 6304 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state); 6305 6306 chan->rx_state = L2CAP_RX_STATE_RECV; 6307 l2cap_process_reqseq(chan, control->reqseq); 6308 6309 if (!skb_queue_empty(&chan->tx_q)) 6310 chan->tx_send_head = skb_peek(&chan->tx_q); 6311 else 6312 chan->tx_send_head = NULL; 6313 6314 /* Rewind next_tx_seq to the point expected 6315 * by the receiver. 6316 */ 6317 chan->next_tx_seq = control->reqseq; 6318 chan->unacked_frames = 0; 6319 chan->conn->mtu = chan->conn->hcon->mtu; 6320 6321 err = l2cap_resegment(chan); 6322 6323 if (!err) 6324 err = l2cap_rx_state_recv(chan, control, skb, event); 6325 6326 return err; 6327 } 6328 6329 static bool __valid_reqseq(struct l2cap_chan *chan, u16 reqseq) 6330 { 6331 /* Make sure reqseq is for a packet that has been sent but not acked */ 6332 u16 unacked; 6333 6334 unacked = __seq_offset(chan, chan->next_tx_seq, chan->expected_ack_seq); 6335 return __seq_offset(chan, chan->next_tx_seq, reqseq) <= unacked; 6336 } 6337 6338 static int l2cap_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control, 6339 struct sk_buff *skb, u8 event) 6340 { 6341 int err = 0; 6342 6343 BT_DBG("chan %p, control %p, skb %p, event %d, state %d", chan, 6344 control, skb, event, chan->rx_state); 6345 6346 if (__valid_reqseq(chan, control->reqseq)) { 6347 switch (chan->rx_state) { 6348 case L2CAP_RX_STATE_RECV: 6349 err = l2cap_rx_state_recv(chan, control, skb, event); 6350 break; 6351 case L2CAP_RX_STATE_SREJ_SENT: 6352 err = l2cap_rx_state_srej_sent(chan, control, skb, 6353 event); 6354 break; 6355 case L2CAP_RX_STATE_WAIT_P: 6356 err = l2cap_rx_state_wait_p(chan, control, skb, event); 6357 break; 6358 case L2CAP_RX_STATE_WAIT_F: 6359 err = l2cap_rx_state_wait_f(chan, control, skb, event); 6360 break; 6361 default: 6362 /* shut it down */ 6363 break; 6364 } 6365 } else { 6366 BT_DBG("Invalid reqseq %d (next_tx_seq %d, expected_ack_seq %d", 6367 control->reqseq, chan->next_tx_seq, 6368 chan->expected_ack_seq); 6369 l2cap_send_disconn_req(chan, ECONNRESET); 6370 } 6371 6372 return err; 6373 } 6374 6375 static int l2cap_stream_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control, 6376 struct sk_buff *skb) 6377 { 6378 /* l2cap_reassemble_sdu may free skb, hence invalidate control, so store 6379 * the txseq field in advance to use it after l2cap_reassemble_sdu 6380 * returns and to avoid the race condition, for example: 6381 * 6382 * The current thread calls: 6383 * l2cap_reassemble_sdu 6384 * chan->ops->recv == l2cap_sock_recv_cb 6385 * __sock_queue_rcv_skb 6386 * Another thread calls: 6387 * bt_sock_recvmsg 6388 * skb_recv_datagram 6389 * skb_free_datagram 6390 * Then the current thread tries to access control, but it was freed by 6391 * skb_free_datagram. 6392 */ 6393 u16 txseq = control->txseq; 6394 6395 BT_DBG("chan %p, control %p, skb %p, state %d", chan, control, skb, 6396 chan->rx_state); 6397 6398 if (l2cap_classify_txseq(chan, txseq) == L2CAP_TXSEQ_EXPECTED) { 6399 l2cap_pass_to_tx(chan, control); 6400 6401 BT_DBG("buffer_seq %u->%u", chan->buffer_seq, 6402 __next_seq(chan, chan->buffer_seq)); 6403 6404 chan->buffer_seq = __next_seq(chan, chan->buffer_seq); 6405 6406 l2cap_reassemble_sdu(chan, skb, control); 6407 } else { 6408 if (chan->sdu) { 6409 kfree_skb(chan->sdu); 6410 chan->sdu = NULL; 6411 } 6412 chan->sdu_last_frag = NULL; 6413 chan->sdu_len = 0; 6414 6415 if (skb) { 6416 BT_DBG("Freeing %p", skb); 6417 kfree_skb(skb); 6418 } 6419 } 6420 6421 chan->last_acked_seq = txseq; 6422 chan->expected_tx_seq = __next_seq(chan, txseq); 6423 6424 return 0; 6425 } 6426 6427 static int l2cap_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb) 6428 { 6429 struct l2cap_ctrl *control = &bt_cb(skb)->l2cap; 6430 u16 len; 6431 u8 event; 6432 6433 __unpack_control(chan, skb); 6434 6435 len = skb->len; 6436 6437 /* 6438 * We can just drop the corrupted I-frame here. 6439 * Receiver will miss it and start proper recovery 6440 * procedures and ask for retransmission. 6441 */ 6442 if (l2cap_check_fcs(chan, skb)) 6443 goto drop; 6444 6445 if (!control->sframe && control->sar == L2CAP_SAR_START) 6446 len -= L2CAP_SDULEN_SIZE; 6447 6448 if (chan->fcs == L2CAP_FCS_CRC16) 6449 len -= L2CAP_FCS_SIZE; 6450 6451 if (len > chan->mps) { 6452 l2cap_send_disconn_req(chan, ECONNRESET); 6453 goto drop; 6454 } 6455 6456 if (chan->ops->filter) { 6457 if (chan->ops->filter(chan, skb)) 6458 goto drop; 6459 } 6460 6461 if (!control->sframe) { 6462 int err; 6463 6464 BT_DBG("iframe sar %d, reqseq %d, final %d, txseq %d", 6465 control->sar, control->reqseq, control->final, 6466 control->txseq); 6467 6468 /* Validate F-bit - F=0 always valid, F=1 only 6469 * valid in TX WAIT_F 6470 */ 6471 if (control->final && chan->tx_state != L2CAP_TX_STATE_WAIT_F) 6472 goto drop; 6473 6474 if (chan->mode != L2CAP_MODE_STREAMING) { 6475 event = L2CAP_EV_RECV_IFRAME; 6476 err = l2cap_rx(chan, control, skb, event); 6477 } else { 6478 err = l2cap_stream_rx(chan, control, skb); 6479 } 6480 6481 if (err) 6482 l2cap_send_disconn_req(chan, ECONNRESET); 6483 } else { 6484 const u8 rx_func_to_event[4] = { 6485 L2CAP_EV_RECV_RR, L2CAP_EV_RECV_REJ, 6486 L2CAP_EV_RECV_RNR, L2CAP_EV_RECV_SREJ 6487 }; 6488 6489 /* Only I-frames are expected in streaming mode */ 6490 if (chan->mode == L2CAP_MODE_STREAMING) 6491 goto drop; 6492 6493 BT_DBG("sframe reqseq %d, final %d, poll %d, super %d", 6494 control->reqseq, control->final, control->poll, 6495 control->super); 6496 6497 if (len != 0) { 6498 BT_ERR("Trailing bytes: %d in sframe", len); 6499 l2cap_send_disconn_req(chan, ECONNRESET); 6500 goto drop; 6501 } 6502 6503 /* Validate F and P bits */ 6504 if (control->final && (control->poll || 6505 chan->tx_state != L2CAP_TX_STATE_WAIT_F)) 6506 goto drop; 6507 6508 event = rx_func_to_event[control->super]; 6509 if (l2cap_rx(chan, control, skb, event)) 6510 l2cap_send_disconn_req(chan, ECONNRESET); 6511 } 6512 6513 return 0; 6514 6515 drop: 6516 kfree_skb(skb); 6517 return 0; 6518 } 6519 6520 static void l2cap_chan_le_send_credits(struct l2cap_chan *chan) 6521 { 6522 struct l2cap_conn *conn = chan->conn; 6523 struct l2cap_le_credits pkt; 6524 u16 return_credits = l2cap_le_rx_credits(chan); 6525 6526 if (chan->rx_credits >= return_credits) 6527 return; 6528 6529 return_credits -= chan->rx_credits; 6530 6531 BT_DBG("chan %p returning %u credits to sender", chan, return_credits); 6532 6533 chan->rx_credits += return_credits; 6534 6535 pkt.cid = cpu_to_le16(chan->scid); 6536 pkt.credits = cpu_to_le16(return_credits); 6537 6538 chan->ident = l2cap_get_ident(conn); 6539 6540 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CREDITS, sizeof(pkt), &pkt); 6541 } 6542 6543 void l2cap_chan_rx_avail(struct l2cap_chan *chan, ssize_t rx_avail) 6544 { 6545 if (chan->rx_avail == rx_avail) 6546 return; 6547 6548 BT_DBG("chan %p has %zd bytes avail for rx", chan, rx_avail); 6549 6550 chan->rx_avail = rx_avail; 6551 6552 if (chan->state == BT_CONNECTED) 6553 l2cap_chan_le_send_credits(chan); 6554 } 6555 6556 static int l2cap_ecred_recv(struct l2cap_chan *chan, struct sk_buff *skb) 6557 { 6558 int err; 6559 6560 BT_DBG("SDU reassemble complete: chan %p skb->len %u", chan, skb->len); 6561 6562 /* Wait recv to confirm reception before updating the credits */ 6563 err = chan->ops->recv(chan, skb); 6564 6565 if (err < 0 && chan->rx_avail != -1) { 6566 BT_ERR("Queueing received LE L2CAP data failed"); 6567 l2cap_send_disconn_req(chan, ECONNRESET); 6568 return err; 6569 } 6570 6571 /* Update credits whenever an SDU is received */ 6572 l2cap_chan_le_send_credits(chan); 6573 6574 return err; 6575 } 6576 6577 static int l2cap_ecred_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb) 6578 { 6579 int err; 6580 6581 if (!chan->rx_credits) { 6582 BT_ERR("No credits to receive LE L2CAP data"); 6583 l2cap_send_disconn_req(chan, ECONNRESET); 6584 return -ENOBUFS; 6585 } 6586 6587 if (chan->imtu < skb->len) { 6588 BT_ERR("Too big LE L2CAP PDU"); 6589 return -ENOBUFS; 6590 } 6591 6592 chan->rx_credits--; 6593 BT_DBG("chan %p: rx_credits %u -> %u", 6594 chan, chan->rx_credits + 1, chan->rx_credits); 6595 6596 /* Update if remote had run out of credits, this should only happens 6597 * if the remote is not using the entire MPS. 6598 */ 6599 if (!chan->rx_credits) 6600 l2cap_chan_le_send_credits(chan); 6601 6602 err = 0; 6603 6604 if (!chan->sdu) { 6605 u16 sdu_len; 6606 6607 sdu_len = get_unaligned_le16(skb->data); 6608 skb_pull(skb, L2CAP_SDULEN_SIZE); 6609 6610 BT_DBG("Start of new SDU. sdu_len %u skb->len %u imtu %u", 6611 sdu_len, skb->len, chan->imtu); 6612 6613 if (sdu_len > chan->imtu) { 6614 BT_ERR("Too big LE L2CAP SDU length received"); 6615 err = -EMSGSIZE; 6616 goto failed; 6617 } 6618 6619 if (skb->len > sdu_len) { 6620 BT_ERR("Too much LE L2CAP data received"); 6621 err = -EINVAL; 6622 goto failed; 6623 } 6624 6625 if (skb->len == sdu_len) 6626 return l2cap_ecred_recv(chan, skb); 6627 6628 chan->sdu = skb; 6629 chan->sdu_len = sdu_len; 6630 chan->sdu_last_frag = skb; 6631 6632 /* Detect if remote is not able to use the selected MPS */ 6633 if (skb->len + L2CAP_SDULEN_SIZE < chan->mps) { 6634 u16 mps_len = skb->len + L2CAP_SDULEN_SIZE; 6635 6636 /* Adjust the number of credits */ 6637 BT_DBG("chan->mps %u -> %u", chan->mps, mps_len); 6638 chan->mps = mps_len; 6639 l2cap_chan_le_send_credits(chan); 6640 } 6641 6642 return 0; 6643 } 6644 6645 BT_DBG("SDU fragment. chan->sdu->len %u skb->len %u chan->sdu_len %u", 6646 chan->sdu->len, skb->len, chan->sdu_len); 6647 6648 if (chan->sdu->len + skb->len > chan->sdu_len) { 6649 BT_ERR("Too much LE L2CAP data received"); 6650 err = -EINVAL; 6651 goto failed; 6652 } 6653 6654 append_skb_frag(chan->sdu, skb, &chan->sdu_last_frag); 6655 skb = NULL; 6656 6657 if (chan->sdu->len == chan->sdu_len) { 6658 err = l2cap_ecred_recv(chan, chan->sdu); 6659 if (!err) { 6660 chan->sdu = NULL; 6661 chan->sdu_last_frag = NULL; 6662 chan->sdu_len = 0; 6663 } 6664 } 6665 6666 failed: 6667 if (err) { 6668 kfree_skb(skb); 6669 kfree_skb(chan->sdu); 6670 chan->sdu = NULL; 6671 chan->sdu_last_frag = NULL; 6672 chan->sdu_len = 0; 6673 } 6674 6675 /* We can't return an error here since we took care of the skb 6676 * freeing internally. An error return would cause the caller to 6677 * do a double-free of the skb. 6678 */ 6679 return 0; 6680 } 6681 6682 static void l2cap_data_channel(struct l2cap_conn *conn, u16 cid, 6683 struct sk_buff *skb) 6684 { 6685 struct l2cap_chan *chan; 6686 6687 chan = l2cap_get_chan_by_scid(conn, cid); 6688 if (!chan) { 6689 BT_DBG("unknown cid 0x%4.4x", cid); 6690 /* Drop packet and return */ 6691 kfree_skb(skb); 6692 return; 6693 } 6694 6695 BT_DBG("chan %p, len %d", chan, skb->len); 6696 6697 /* If we receive data on a fixed channel before the info req/rsp 6698 * procedure is done simply assume that the channel is supported 6699 * and mark it as ready. 6700 */ 6701 if (chan->chan_type == L2CAP_CHAN_FIXED) 6702 l2cap_chan_ready(chan); 6703 6704 if (chan->state != BT_CONNECTED) 6705 goto drop; 6706 6707 switch (chan->mode) { 6708 case L2CAP_MODE_LE_FLOWCTL: 6709 case L2CAP_MODE_EXT_FLOWCTL: 6710 if (l2cap_ecred_data_rcv(chan, skb) < 0) 6711 goto drop; 6712 6713 goto done; 6714 6715 case L2CAP_MODE_BASIC: 6716 /* If socket recv buffers overflows we drop data here 6717 * which is *bad* because L2CAP has to be reliable. 6718 * But we don't have any other choice. L2CAP doesn't 6719 * provide flow control mechanism. */ 6720 6721 if (chan->imtu < skb->len) { 6722 BT_ERR("Dropping L2CAP data: receive buffer overflow"); 6723 goto drop; 6724 } 6725 6726 if (!chan->ops->recv(chan, skb)) 6727 goto done; 6728 break; 6729 6730 case L2CAP_MODE_ERTM: 6731 case L2CAP_MODE_STREAMING: 6732 l2cap_data_rcv(chan, skb); 6733 goto done; 6734 6735 default: 6736 BT_DBG("chan %p: bad mode 0x%2.2x", chan, chan->mode); 6737 break; 6738 } 6739 6740 drop: 6741 kfree_skb(skb); 6742 6743 done: 6744 l2cap_chan_unlock(chan); 6745 l2cap_chan_put(chan); 6746 } 6747 6748 static void l2cap_conless_channel(struct l2cap_conn *conn, __le16 psm, 6749 struct sk_buff *skb) 6750 { 6751 struct hci_conn *hcon = conn->hcon; 6752 struct l2cap_chan *chan; 6753 6754 if (hcon->type != ACL_LINK) 6755 goto free_skb; 6756 6757 chan = l2cap_global_chan_by_psm(0, psm, &hcon->src, &hcon->dst, 6758 ACL_LINK); 6759 if (!chan) 6760 goto free_skb; 6761 6762 BT_DBG("chan %p, len %d", chan, skb->len); 6763 6764 l2cap_chan_lock(chan); 6765 6766 if (chan->state != BT_BOUND && chan->state != BT_CONNECTED) 6767 goto drop; 6768 6769 if (chan->imtu < skb->len) 6770 goto drop; 6771 6772 /* Store remote BD_ADDR and PSM for msg_name */ 6773 bacpy(&bt_cb(skb)->l2cap.bdaddr, &hcon->dst); 6774 bt_cb(skb)->l2cap.psm = psm; 6775 6776 if (!chan->ops->recv(chan, skb)) { 6777 l2cap_chan_unlock(chan); 6778 l2cap_chan_put(chan); 6779 return; 6780 } 6781 6782 drop: 6783 l2cap_chan_unlock(chan); 6784 l2cap_chan_put(chan); 6785 free_skb: 6786 kfree_skb(skb); 6787 } 6788 6789 static void l2cap_recv_frame(struct l2cap_conn *conn, struct sk_buff *skb) 6790 { 6791 struct l2cap_hdr *lh = (void *) skb->data; 6792 struct hci_conn *hcon = conn->hcon; 6793 u16 cid, len; 6794 __le16 psm; 6795 6796 if (hcon->state != BT_CONNECTED) { 6797 BT_DBG("queueing pending rx skb"); 6798 skb_queue_tail(&conn->pending_rx, skb); 6799 return; 6800 } 6801 6802 skb_pull(skb, L2CAP_HDR_SIZE); 6803 cid = __le16_to_cpu(lh->cid); 6804 len = __le16_to_cpu(lh->len); 6805 6806 if (len != skb->len) { 6807 kfree_skb(skb); 6808 return; 6809 } 6810 6811 /* Since we can't actively block incoming LE connections we must 6812 * at least ensure that we ignore incoming data from them. 6813 */ 6814 if (hcon->type == LE_LINK && 6815 hci_bdaddr_list_lookup(&hcon->hdev->reject_list, &hcon->dst, 6816 bdaddr_dst_type(hcon))) { 6817 kfree_skb(skb); 6818 return; 6819 } 6820 6821 BT_DBG("len %d, cid 0x%4.4x", len, cid); 6822 6823 switch (cid) { 6824 case L2CAP_CID_SIGNALING: 6825 l2cap_sig_channel(conn, skb); 6826 break; 6827 6828 case L2CAP_CID_CONN_LESS: 6829 psm = get_unaligned((__le16 *) skb->data); 6830 skb_pull(skb, L2CAP_PSMLEN_SIZE); 6831 l2cap_conless_channel(conn, psm, skb); 6832 break; 6833 6834 case L2CAP_CID_LE_SIGNALING: 6835 l2cap_le_sig_channel(conn, skb); 6836 break; 6837 6838 default: 6839 l2cap_data_channel(conn, cid, skb); 6840 break; 6841 } 6842 } 6843 6844 static void process_pending_rx(struct work_struct *work) 6845 { 6846 struct l2cap_conn *conn = container_of(work, struct l2cap_conn, 6847 pending_rx_work); 6848 struct sk_buff *skb; 6849 6850 BT_DBG(""); 6851 6852 while ((skb = skb_dequeue(&conn->pending_rx))) 6853 l2cap_recv_frame(conn, skb); 6854 } 6855 6856 static struct l2cap_conn *l2cap_conn_add(struct hci_conn *hcon) 6857 { 6858 struct l2cap_conn *conn = hcon->l2cap_data; 6859 struct hci_chan *hchan; 6860 6861 if (conn) 6862 return conn; 6863 6864 hchan = hci_chan_create(hcon); 6865 if (!hchan) 6866 return NULL; 6867 6868 conn = kzalloc(sizeof(*conn), GFP_KERNEL); 6869 if (!conn) { 6870 hci_chan_del(hchan); 6871 return NULL; 6872 } 6873 6874 kref_init(&conn->ref); 6875 hcon->l2cap_data = conn; 6876 conn->hcon = hci_conn_get(hcon); 6877 conn->hchan = hchan; 6878 6879 BT_DBG("hcon %p conn %p hchan %p", hcon, conn, hchan); 6880 6881 conn->mtu = hcon->mtu; 6882 conn->feat_mask = 0; 6883 6884 conn->local_fixed_chan = L2CAP_FC_SIG_BREDR | L2CAP_FC_CONNLESS; 6885 6886 if (hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED) && 6887 (bredr_sc_enabled(hcon->hdev) || 6888 hci_dev_test_flag(hcon->hdev, HCI_FORCE_BREDR_SMP))) 6889 conn->local_fixed_chan |= L2CAP_FC_SMP_BREDR; 6890 6891 mutex_init(&conn->ident_lock); 6892 mutex_init(&conn->chan_lock); 6893 6894 INIT_LIST_HEAD(&conn->chan_l); 6895 INIT_LIST_HEAD(&conn->users); 6896 6897 INIT_DELAYED_WORK(&conn->info_timer, l2cap_info_timeout); 6898 6899 skb_queue_head_init(&conn->pending_rx); 6900 INIT_WORK(&conn->pending_rx_work, process_pending_rx); 6901 INIT_DELAYED_WORK(&conn->id_addr_timer, l2cap_conn_update_id_addr); 6902 6903 conn->disc_reason = HCI_ERROR_REMOTE_USER_TERM; 6904 6905 return conn; 6906 } 6907 6908 static bool is_valid_psm(u16 psm, u8 dst_type) 6909 { 6910 if (!psm) 6911 return false; 6912 6913 if (bdaddr_type_is_le(dst_type)) 6914 return (psm <= 0x00ff); 6915 6916 /* PSM must be odd and lsb of upper byte must be 0 */ 6917 return ((psm & 0x0101) == 0x0001); 6918 } 6919 6920 struct l2cap_chan_data { 6921 struct l2cap_chan *chan; 6922 struct pid *pid; 6923 int count; 6924 }; 6925 6926 static void l2cap_chan_by_pid(struct l2cap_chan *chan, void *data) 6927 { 6928 struct l2cap_chan_data *d = data; 6929 struct pid *pid; 6930 6931 if (chan == d->chan) 6932 return; 6933 6934 if (!test_bit(FLAG_DEFER_SETUP, &chan->flags)) 6935 return; 6936 6937 pid = chan->ops->get_peer_pid(chan); 6938 6939 /* Only count deferred channels with the same PID/PSM */ 6940 if (d->pid != pid || chan->psm != d->chan->psm || chan->ident || 6941 chan->mode != L2CAP_MODE_EXT_FLOWCTL || chan->state != BT_CONNECT) 6942 return; 6943 6944 d->count++; 6945 } 6946 6947 int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid, 6948 bdaddr_t *dst, u8 dst_type, u16 timeout) 6949 { 6950 struct l2cap_conn *conn; 6951 struct hci_conn *hcon; 6952 struct hci_dev *hdev; 6953 int err; 6954 6955 BT_DBG("%pMR -> %pMR (type %u) psm 0x%4.4x mode 0x%2.2x", &chan->src, 6956 dst, dst_type, __le16_to_cpu(psm), chan->mode); 6957 6958 hdev = hci_get_route(dst, &chan->src, chan->src_type); 6959 if (!hdev) 6960 return -EHOSTUNREACH; 6961 6962 hci_dev_lock(hdev); 6963 6964 if (!is_valid_psm(__le16_to_cpu(psm), dst_type) && !cid && 6965 chan->chan_type != L2CAP_CHAN_RAW) { 6966 err = -EINVAL; 6967 goto done; 6968 } 6969 6970 if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED && !psm) { 6971 err = -EINVAL; 6972 goto done; 6973 } 6974 6975 if (chan->chan_type == L2CAP_CHAN_FIXED && !cid) { 6976 err = -EINVAL; 6977 goto done; 6978 } 6979 6980 switch (chan->mode) { 6981 case L2CAP_MODE_BASIC: 6982 break; 6983 case L2CAP_MODE_LE_FLOWCTL: 6984 break; 6985 case L2CAP_MODE_EXT_FLOWCTL: 6986 if (!enable_ecred) { 6987 err = -EOPNOTSUPP; 6988 goto done; 6989 } 6990 break; 6991 case L2CAP_MODE_ERTM: 6992 case L2CAP_MODE_STREAMING: 6993 if (!disable_ertm) 6994 break; 6995 fallthrough; 6996 default: 6997 err = -EOPNOTSUPP; 6998 goto done; 6999 } 7000 7001 switch (chan->state) { 7002 case BT_CONNECT: 7003 case BT_CONNECT2: 7004 case BT_CONFIG: 7005 /* Already connecting */ 7006 err = 0; 7007 goto done; 7008 7009 case BT_CONNECTED: 7010 /* Already connected */ 7011 err = -EISCONN; 7012 goto done; 7013 7014 case BT_OPEN: 7015 case BT_BOUND: 7016 /* Can connect */ 7017 break; 7018 7019 default: 7020 err = -EBADFD; 7021 goto done; 7022 } 7023 7024 /* Set destination address and psm */ 7025 bacpy(&chan->dst, dst); 7026 chan->dst_type = dst_type; 7027 7028 chan->psm = psm; 7029 chan->dcid = cid; 7030 7031 if (bdaddr_type_is_le(dst_type)) { 7032 /* Convert from L2CAP channel address type to HCI address type 7033 */ 7034 if (dst_type == BDADDR_LE_PUBLIC) 7035 dst_type = ADDR_LE_DEV_PUBLIC; 7036 else 7037 dst_type = ADDR_LE_DEV_RANDOM; 7038 7039 if (hci_dev_test_flag(hdev, HCI_ADVERTISING)) 7040 hcon = hci_connect_le(hdev, dst, dst_type, false, 7041 chan->sec_level, timeout, 7042 HCI_ROLE_SLAVE, 0, 0); 7043 else 7044 hcon = hci_connect_le_scan(hdev, dst, dst_type, 7045 chan->sec_level, timeout, 7046 CONN_REASON_L2CAP_CHAN); 7047 7048 } else { 7049 u8 auth_type = l2cap_get_auth_type(chan); 7050 hcon = hci_connect_acl(hdev, dst, chan->sec_level, auth_type, 7051 CONN_REASON_L2CAP_CHAN, timeout); 7052 } 7053 7054 if (IS_ERR(hcon)) { 7055 err = PTR_ERR(hcon); 7056 goto done; 7057 } 7058 7059 conn = l2cap_conn_add(hcon); 7060 if (!conn) { 7061 hci_conn_drop(hcon); 7062 err = -ENOMEM; 7063 goto done; 7064 } 7065 7066 if (chan->mode == L2CAP_MODE_EXT_FLOWCTL) { 7067 struct l2cap_chan_data data; 7068 7069 data.chan = chan; 7070 data.pid = chan->ops->get_peer_pid(chan); 7071 data.count = 1; 7072 7073 l2cap_chan_list(conn, l2cap_chan_by_pid, &data); 7074 7075 /* Check if there isn't too many channels being connected */ 7076 if (data.count > L2CAP_ECRED_CONN_SCID_MAX) { 7077 hci_conn_drop(hcon); 7078 err = -EPROTO; 7079 goto done; 7080 } 7081 } 7082 7083 mutex_lock(&conn->chan_lock); 7084 l2cap_chan_lock(chan); 7085 7086 if (cid && __l2cap_get_chan_by_dcid(conn, cid)) { 7087 hci_conn_drop(hcon); 7088 err = -EBUSY; 7089 goto chan_unlock; 7090 } 7091 7092 /* Update source addr of the socket */ 7093 bacpy(&chan->src, &hcon->src); 7094 chan->src_type = bdaddr_src_type(hcon); 7095 7096 __l2cap_chan_add(conn, chan); 7097 7098 /* l2cap_chan_add takes its own ref so we can drop this one */ 7099 hci_conn_drop(hcon); 7100 7101 l2cap_state_change(chan, BT_CONNECT); 7102 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan)); 7103 7104 /* Release chan->sport so that it can be reused by other 7105 * sockets (as it's only used for listening sockets). 7106 */ 7107 write_lock(&chan_list_lock); 7108 chan->sport = 0; 7109 write_unlock(&chan_list_lock); 7110 7111 if (hcon->state == BT_CONNECTED) { 7112 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) { 7113 __clear_chan_timer(chan); 7114 if (l2cap_chan_check_security(chan, true)) 7115 l2cap_state_change(chan, BT_CONNECTED); 7116 } else 7117 l2cap_do_start(chan); 7118 } 7119 7120 err = 0; 7121 7122 chan_unlock: 7123 l2cap_chan_unlock(chan); 7124 mutex_unlock(&conn->chan_lock); 7125 done: 7126 hci_dev_unlock(hdev); 7127 hci_dev_put(hdev); 7128 return err; 7129 } 7130 EXPORT_SYMBOL_GPL(l2cap_chan_connect); 7131 7132 static void l2cap_ecred_reconfigure(struct l2cap_chan *chan) 7133 { 7134 struct l2cap_conn *conn = chan->conn; 7135 DEFINE_RAW_FLEX(struct l2cap_ecred_reconf_req, pdu, scid, 1); 7136 7137 pdu->mtu = cpu_to_le16(chan->imtu); 7138 pdu->mps = cpu_to_le16(chan->mps); 7139 pdu->scid[0] = cpu_to_le16(chan->scid); 7140 7141 chan->ident = l2cap_get_ident(conn); 7142 7143 l2cap_send_cmd(conn, chan->ident, L2CAP_ECRED_RECONF_REQ, 7144 sizeof(pdu), &pdu); 7145 } 7146 7147 int l2cap_chan_reconfigure(struct l2cap_chan *chan, __u16 mtu) 7148 { 7149 if (chan->imtu > mtu) 7150 return -EINVAL; 7151 7152 BT_DBG("chan %p mtu 0x%4.4x", chan, mtu); 7153 7154 chan->imtu = mtu; 7155 7156 l2cap_ecred_reconfigure(chan); 7157 7158 return 0; 7159 } 7160 7161 /* ---- L2CAP interface with lower layer (HCI) ---- */ 7162 7163 int l2cap_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr) 7164 { 7165 int exact = 0, lm1 = 0, lm2 = 0; 7166 struct l2cap_chan *c; 7167 7168 BT_DBG("hdev %s, bdaddr %pMR", hdev->name, bdaddr); 7169 7170 /* Find listening sockets and check their link_mode */ 7171 read_lock(&chan_list_lock); 7172 list_for_each_entry(c, &chan_list, global_l) { 7173 if (c->state != BT_LISTEN) 7174 continue; 7175 7176 if (!bacmp(&c->src, &hdev->bdaddr)) { 7177 lm1 |= HCI_LM_ACCEPT; 7178 if (test_bit(FLAG_ROLE_SWITCH, &c->flags)) 7179 lm1 |= HCI_LM_MASTER; 7180 exact++; 7181 } else if (!bacmp(&c->src, BDADDR_ANY)) { 7182 lm2 |= HCI_LM_ACCEPT; 7183 if (test_bit(FLAG_ROLE_SWITCH, &c->flags)) 7184 lm2 |= HCI_LM_MASTER; 7185 } 7186 } 7187 read_unlock(&chan_list_lock); 7188 7189 return exact ? lm1 : lm2; 7190 } 7191 7192 /* Find the next fixed channel in BT_LISTEN state, continue iteration 7193 * from an existing channel in the list or from the beginning of the 7194 * global list (by passing NULL as first parameter). 7195 */ 7196 static struct l2cap_chan *l2cap_global_fixed_chan(struct l2cap_chan *c, 7197 struct hci_conn *hcon) 7198 { 7199 u8 src_type = bdaddr_src_type(hcon); 7200 7201 read_lock(&chan_list_lock); 7202 7203 if (c) 7204 c = list_next_entry(c, global_l); 7205 else 7206 c = list_entry(chan_list.next, typeof(*c), global_l); 7207 7208 list_for_each_entry_from(c, &chan_list, global_l) { 7209 if (c->chan_type != L2CAP_CHAN_FIXED) 7210 continue; 7211 if (c->state != BT_LISTEN) 7212 continue; 7213 if (bacmp(&c->src, &hcon->src) && bacmp(&c->src, BDADDR_ANY)) 7214 continue; 7215 if (src_type != c->src_type) 7216 continue; 7217 7218 c = l2cap_chan_hold_unless_zero(c); 7219 read_unlock(&chan_list_lock); 7220 return c; 7221 } 7222 7223 read_unlock(&chan_list_lock); 7224 7225 return NULL; 7226 } 7227 7228 static void l2cap_connect_cfm(struct hci_conn *hcon, u8 status) 7229 { 7230 struct hci_dev *hdev = hcon->hdev; 7231 struct l2cap_conn *conn; 7232 struct l2cap_chan *pchan; 7233 u8 dst_type; 7234 7235 if (hcon->type != ACL_LINK && hcon->type != LE_LINK) 7236 return; 7237 7238 BT_DBG("hcon %p bdaddr %pMR status %d", hcon, &hcon->dst, status); 7239 7240 if (status) { 7241 l2cap_conn_del(hcon, bt_to_errno(status)); 7242 return; 7243 } 7244 7245 conn = l2cap_conn_add(hcon); 7246 if (!conn) 7247 return; 7248 7249 dst_type = bdaddr_dst_type(hcon); 7250 7251 /* If device is blocked, do not create channels for it */ 7252 if (hci_bdaddr_list_lookup(&hdev->reject_list, &hcon->dst, dst_type)) 7253 return; 7254 7255 /* Find fixed channels and notify them of the new connection. We 7256 * use multiple individual lookups, continuing each time where 7257 * we left off, because the list lock would prevent calling the 7258 * potentially sleeping l2cap_chan_lock() function. 7259 */ 7260 pchan = l2cap_global_fixed_chan(NULL, hcon); 7261 while (pchan) { 7262 struct l2cap_chan *chan, *next; 7263 7264 /* Client fixed channels should override server ones */ 7265 if (__l2cap_get_chan_by_dcid(conn, pchan->scid)) 7266 goto next; 7267 7268 l2cap_chan_lock(pchan); 7269 chan = pchan->ops->new_connection(pchan); 7270 if (chan) { 7271 bacpy(&chan->src, &hcon->src); 7272 bacpy(&chan->dst, &hcon->dst); 7273 chan->src_type = bdaddr_src_type(hcon); 7274 chan->dst_type = dst_type; 7275 7276 __l2cap_chan_add(conn, chan); 7277 } 7278 7279 l2cap_chan_unlock(pchan); 7280 next: 7281 next = l2cap_global_fixed_chan(pchan, hcon); 7282 l2cap_chan_put(pchan); 7283 pchan = next; 7284 } 7285 7286 l2cap_conn_ready(conn); 7287 } 7288 7289 int l2cap_disconn_ind(struct hci_conn *hcon) 7290 { 7291 struct l2cap_conn *conn = hcon->l2cap_data; 7292 7293 BT_DBG("hcon %p", hcon); 7294 7295 if (!conn) 7296 return HCI_ERROR_REMOTE_USER_TERM; 7297 return conn->disc_reason; 7298 } 7299 7300 static void l2cap_disconn_cfm(struct hci_conn *hcon, u8 reason) 7301 { 7302 if (hcon->type != ACL_LINK && hcon->type != LE_LINK) 7303 return; 7304 7305 BT_DBG("hcon %p reason %d", hcon, reason); 7306 7307 l2cap_conn_del(hcon, bt_to_errno(reason)); 7308 } 7309 7310 static inline void l2cap_check_encryption(struct l2cap_chan *chan, u8 encrypt) 7311 { 7312 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) 7313 return; 7314 7315 if (encrypt == 0x00) { 7316 if (chan->sec_level == BT_SECURITY_MEDIUM) { 7317 __set_chan_timer(chan, L2CAP_ENC_TIMEOUT); 7318 } else if (chan->sec_level == BT_SECURITY_HIGH || 7319 chan->sec_level == BT_SECURITY_FIPS) 7320 l2cap_chan_close(chan, ECONNREFUSED); 7321 } else { 7322 if (chan->sec_level == BT_SECURITY_MEDIUM) 7323 __clear_chan_timer(chan); 7324 } 7325 } 7326 7327 static void l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt) 7328 { 7329 struct l2cap_conn *conn = hcon->l2cap_data; 7330 struct l2cap_chan *chan; 7331 7332 if (!conn) 7333 return; 7334 7335 BT_DBG("conn %p status 0x%2.2x encrypt %u", conn, status, encrypt); 7336 7337 mutex_lock(&conn->chan_lock); 7338 7339 list_for_each_entry(chan, &conn->chan_l, list) { 7340 l2cap_chan_lock(chan); 7341 7342 BT_DBG("chan %p scid 0x%4.4x state %s", chan, chan->scid, 7343 state_to_string(chan->state)); 7344 7345 if (!status && encrypt) 7346 chan->sec_level = hcon->sec_level; 7347 7348 if (!__l2cap_no_conn_pending(chan)) { 7349 l2cap_chan_unlock(chan); 7350 continue; 7351 } 7352 7353 if (!status && (chan->state == BT_CONNECTED || 7354 chan->state == BT_CONFIG)) { 7355 chan->ops->resume(chan); 7356 l2cap_check_encryption(chan, encrypt); 7357 l2cap_chan_unlock(chan); 7358 continue; 7359 } 7360 7361 if (chan->state == BT_CONNECT) { 7362 if (!status && l2cap_check_enc_key_size(hcon)) 7363 l2cap_start_connection(chan); 7364 else 7365 __set_chan_timer(chan, L2CAP_DISC_TIMEOUT); 7366 } else if (chan->state == BT_CONNECT2 && 7367 !(chan->mode == L2CAP_MODE_EXT_FLOWCTL || 7368 chan->mode == L2CAP_MODE_LE_FLOWCTL)) { 7369 struct l2cap_conn_rsp rsp; 7370 __u16 res, stat; 7371 7372 if (!status && l2cap_check_enc_key_size(hcon)) { 7373 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) { 7374 res = L2CAP_CR_PEND; 7375 stat = L2CAP_CS_AUTHOR_PEND; 7376 chan->ops->defer(chan); 7377 } else { 7378 l2cap_state_change(chan, BT_CONFIG); 7379 res = L2CAP_CR_SUCCESS; 7380 stat = L2CAP_CS_NO_INFO; 7381 } 7382 } else { 7383 l2cap_state_change(chan, BT_DISCONN); 7384 __set_chan_timer(chan, L2CAP_DISC_TIMEOUT); 7385 res = L2CAP_CR_SEC_BLOCK; 7386 stat = L2CAP_CS_NO_INFO; 7387 } 7388 7389 rsp.scid = cpu_to_le16(chan->dcid); 7390 rsp.dcid = cpu_to_le16(chan->scid); 7391 rsp.result = cpu_to_le16(res); 7392 rsp.status = cpu_to_le16(stat); 7393 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP, 7394 sizeof(rsp), &rsp); 7395 7396 if (!test_bit(CONF_REQ_SENT, &chan->conf_state) && 7397 res == L2CAP_CR_SUCCESS) { 7398 char buf[128]; 7399 set_bit(CONF_REQ_SENT, &chan->conf_state); 7400 l2cap_send_cmd(conn, l2cap_get_ident(conn), 7401 L2CAP_CONF_REQ, 7402 l2cap_build_conf_req(chan, buf, sizeof(buf)), 7403 buf); 7404 chan->num_conf_req++; 7405 } 7406 } 7407 7408 l2cap_chan_unlock(chan); 7409 } 7410 7411 mutex_unlock(&conn->chan_lock); 7412 } 7413 7414 /* Append fragment into frame respecting the maximum len of rx_skb */ 7415 static int l2cap_recv_frag(struct l2cap_conn *conn, struct sk_buff *skb, 7416 u16 len) 7417 { 7418 if (!conn->rx_skb) { 7419 /* Allocate skb for the complete frame (with header) */ 7420 conn->rx_skb = bt_skb_alloc(len, GFP_KERNEL); 7421 if (!conn->rx_skb) 7422 return -ENOMEM; 7423 /* Init rx_len */ 7424 conn->rx_len = len; 7425 } 7426 7427 /* Copy as much as the rx_skb can hold */ 7428 len = min_t(u16, len, skb->len); 7429 skb_copy_from_linear_data(skb, skb_put(conn->rx_skb, len), len); 7430 skb_pull(skb, len); 7431 conn->rx_len -= len; 7432 7433 return len; 7434 } 7435 7436 static int l2cap_recv_len(struct l2cap_conn *conn, struct sk_buff *skb) 7437 { 7438 struct sk_buff *rx_skb; 7439 int len; 7440 7441 /* Append just enough to complete the header */ 7442 len = l2cap_recv_frag(conn, skb, L2CAP_LEN_SIZE - conn->rx_skb->len); 7443 7444 /* If header could not be read just continue */ 7445 if (len < 0 || conn->rx_skb->len < L2CAP_LEN_SIZE) 7446 return len; 7447 7448 rx_skb = conn->rx_skb; 7449 len = get_unaligned_le16(rx_skb->data); 7450 7451 /* Check if rx_skb has enough space to received all fragments */ 7452 if (len + (L2CAP_HDR_SIZE - L2CAP_LEN_SIZE) <= skb_tailroom(rx_skb)) { 7453 /* Update expected len */ 7454 conn->rx_len = len + (L2CAP_HDR_SIZE - L2CAP_LEN_SIZE); 7455 return L2CAP_LEN_SIZE; 7456 } 7457 7458 /* Reset conn->rx_skb since it will need to be reallocated in order to 7459 * fit all fragments. 7460 */ 7461 conn->rx_skb = NULL; 7462 7463 /* Reallocates rx_skb using the exact expected length */ 7464 len = l2cap_recv_frag(conn, rx_skb, 7465 len + (L2CAP_HDR_SIZE - L2CAP_LEN_SIZE)); 7466 kfree_skb(rx_skb); 7467 7468 return len; 7469 } 7470 7471 static void l2cap_recv_reset(struct l2cap_conn *conn) 7472 { 7473 kfree_skb(conn->rx_skb); 7474 conn->rx_skb = NULL; 7475 conn->rx_len = 0; 7476 } 7477 7478 void l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 flags) 7479 { 7480 struct l2cap_conn *conn = hcon->l2cap_data; 7481 int len; 7482 7483 if (!conn) 7484 conn = l2cap_conn_add(hcon); 7485 7486 if (!conn) 7487 goto drop; 7488 7489 BT_DBG("conn %p len %u flags 0x%x", conn, skb->len, flags); 7490 7491 switch (flags) { 7492 case ACL_START: 7493 case ACL_START_NO_FLUSH: 7494 case ACL_COMPLETE: 7495 if (conn->rx_skb) { 7496 BT_ERR("Unexpected start frame (len %d)", skb->len); 7497 l2cap_recv_reset(conn); 7498 l2cap_conn_unreliable(conn, ECOMM); 7499 } 7500 7501 /* Start fragment may not contain the L2CAP length so just 7502 * copy the initial byte when that happens and use conn->mtu as 7503 * expected length. 7504 */ 7505 if (skb->len < L2CAP_LEN_SIZE) { 7506 l2cap_recv_frag(conn, skb, conn->mtu); 7507 break; 7508 } 7509 7510 len = get_unaligned_le16(skb->data) + L2CAP_HDR_SIZE; 7511 7512 if (len == skb->len) { 7513 /* Complete frame received */ 7514 l2cap_recv_frame(conn, skb); 7515 return; 7516 } 7517 7518 BT_DBG("Start: total len %d, frag len %u", len, skb->len); 7519 7520 if (skb->len > len) { 7521 BT_ERR("Frame is too long (len %u, expected len %d)", 7522 skb->len, len); 7523 l2cap_conn_unreliable(conn, ECOMM); 7524 goto drop; 7525 } 7526 7527 /* Append fragment into frame (with header) */ 7528 if (l2cap_recv_frag(conn, skb, len) < 0) 7529 goto drop; 7530 7531 break; 7532 7533 case ACL_CONT: 7534 BT_DBG("Cont: frag len %u (expecting %u)", skb->len, conn->rx_len); 7535 7536 if (!conn->rx_skb) { 7537 BT_ERR("Unexpected continuation frame (len %d)", skb->len); 7538 l2cap_conn_unreliable(conn, ECOMM); 7539 goto drop; 7540 } 7541 7542 /* Complete the L2CAP length if it has not been read */ 7543 if (conn->rx_skb->len < L2CAP_LEN_SIZE) { 7544 if (l2cap_recv_len(conn, skb) < 0) { 7545 l2cap_conn_unreliable(conn, ECOMM); 7546 goto drop; 7547 } 7548 7549 /* Header still could not be read just continue */ 7550 if (conn->rx_skb->len < L2CAP_LEN_SIZE) 7551 break; 7552 } 7553 7554 if (skb->len > conn->rx_len) { 7555 BT_ERR("Fragment is too long (len %u, expected %u)", 7556 skb->len, conn->rx_len); 7557 l2cap_recv_reset(conn); 7558 l2cap_conn_unreliable(conn, ECOMM); 7559 goto drop; 7560 } 7561 7562 /* Append fragment into frame (with header) */ 7563 l2cap_recv_frag(conn, skb, skb->len); 7564 7565 if (!conn->rx_len) { 7566 /* Complete frame received. l2cap_recv_frame 7567 * takes ownership of the skb so set the global 7568 * rx_skb pointer to NULL first. 7569 */ 7570 struct sk_buff *rx_skb = conn->rx_skb; 7571 conn->rx_skb = NULL; 7572 l2cap_recv_frame(conn, rx_skb); 7573 } 7574 break; 7575 } 7576 7577 drop: 7578 kfree_skb(skb); 7579 } 7580 7581 static struct hci_cb l2cap_cb = { 7582 .name = "L2CAP", 7583 .connect_cfm = l2cap_connect_cfm, 7584 .disconn_cfm = l2cap_disconn_cfm, 7585 .security_cfm = l2cap_security_cfm, 7586 }; 7587 7588 static int l2cap_debugfs_show(struct seq_file *f, void *p) 7589 { 7590 struct l2cap_chan *c; 7591 7592 read_lock(&chan_list_lock); 7593 7594 list_for_each_entry(c, &chan_list, global_l) { 7595 seq_printf(f, "%pMR (%u) %pMR (%u) %d %d 0x%4.4x 0x%4.4x %d %d %d %d\n", 7596 &c->src, c->src_type, &c->dst, c->dst_type, 7597 c->state, __le16_to_cpu(c->psm), 7598 c->scid, c->dcid, c->imtu, c->omtu, 7599 c->sec_level, c->mode); 7600 } 7601 7602 read_unlock(&chan_list_lock); 7603 7604 return 0; 7605 } 7606 7607 DEFINE_SHOW_ATTRIBUTE(l2cap_debugfs); 7608 7609 static struct dentry *l2cap_debugfs; 7610 7611 int __init l2cap_init(void) 7612 { 7613 int err; 7614 7615 err = l2cap_init_sockets(); 7616 if (err < 0) 7617 return err; 7618 7619 hci_register_cb(&l2cap_cb); 7620 7621 if (IS_ERR_OR_NULL(bt_debugfs)) 7622 return 0; 7623 7624 l2cap_debugfs = debugfs_create_file("l2cap", 0444, bt_debugfs, 7625 NULL, &l2cap_debugfs_fops); 7626 7627 return 0; 7628 } 7629 7630 void l2cap_exit(void) 7631 { 7632 debugfs_remove(l2cap_debugfs); 7633 hci_unregister_cb(&l2cap_cb); 7634 l2cap_cleanup_sockets(); 7635 } 7636 7637 module_param(disable_ertm, bool, 0644); 7638 MODULE_PARM_DESC(disable_ertm, "Disable enhanced retransmission mode"); 7639 7640 module_param(enable_ecred, bool, 0644); 7641 MODULE_PARM_DESC(enable_ecred, "Enable enhanced credit flow control mode"); 7642