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 bdaddr_type(u8 link_type,u8 bdaddr_type)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 bdaddr_src_type(struct hci_conn * hcon)78 static inline u8 bdaddr_src_type(struct hci_conn *hcon) 79 { 80 return bdaddr_type(hcon->type, hcon->src_type); 81 } 82 bdaddr_dst_type(struct hci_conn * hcon)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 __l2cap_get_chan_by_dcid(struct l2cap_conn * conn,u16 cid)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 __l2cap_get_chan_by_scid(struct l2cap_conn * conn,u16 cid)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 */ l2cap_get_chan_by_scid(struct l2cap_conn * conn,u16 cid)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 */ l2cap_get_chan_by_dcid(struct l2cap_conn * conn,u16 cid)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 __l2cap_get_chan_by_ident(struct l2cap_conn * conn,u8 ident)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 __l2cap_global_chan_by_addr(__le16 psm,bdaddr_t * src,u8 src_type)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 l2cap_add_psm(struct l2cap_chan * chan,bdaddr_t * src,__le16 psm)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 l2cap_add_scid(struct l2cap_chan * chan,__u16 scid)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 l2cap_alloc_cid(struct l2cap_conn * conn)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 l2cap_state_change(struct l2cap_chan * chan,int state)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 l2cap_state_change_and_error(struct l2cap_chan * chan,int state,int err)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 l2cap_chan_set_err(struct l2cap_chan * chan,int err)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 __set_retrans_timer(struct l2cap_chan * chan)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 __set_monitor_timer(struct l2cap_chan * chan)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 l2cap_ertm_seq_in_queue(struct sk_buff_head * head,u16 seq)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 l2cap_seq_list_init(struct l2cap_seq_list * seq_list,u16 size)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 l2cap_seq_list_free(struct l2cap_seq_list * seq_list)349 static inline void l2cap_seq_list_free(struct l2cap_seq_list *seq_list) 350 { 351 kfree(seq_list->list); 352 } 353 l2cap_seq_list_contains(struct l2cap_seq_list * seq_list,u16 seq)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 l2cap_seq_list_pop(struct l2cap_seq_list * seq_list)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 l2cap_seq_list_clear(struct l2cap_seq_list * seq_list)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 l2cap_seq_list_append(struct l2cap_seq_list * seq_list,u16 seq)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 l2cap_chan_timeout(struct work_struct * work)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 l2cap_chan_create(void)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 l2cap_chan_destroy(struct kref * kref)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 l2cap_chan_hold(struct l2cap_chan * c)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 l2cap_chan_hold_unless_zero(struct l2cap_chan * c)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 l2cap_chan_put(struct l2cap_chan * c)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 l2cap_chan_set_defaults(struct l2cap_chan * chan)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 l2cap_le_rx_credits(struct l2cap_chan * chan)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 l2cap_le_flowctl_init(struct l2cap_chan * chan,u16 tx_credits)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 l2cap_ecred_init(struct l2cap_chan * chan,u16 tx_credits)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 __l2cap_chan_add(struct l2cap_conn * conn,struct l2cap_chan * chan)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 l2cap_chan_add(struct l2cap_conn * conn,struct l2cap_chan * chan)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 l2cap_chan_del(struct l2cap_chan * chan,int err)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 __l2cap_chan_list_id(struct l2cap_conn * conn,u16 id,l2cap_chan_func_t func,void * data)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 __l2cap_chan_list(struct l2cap_conn * conn,l2cap_chan_func_t func,void * data)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 l2cap_chan_list(struct l2cap_conn * conn,l2cap_chan_func_t func,void * data)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 l2cap_conn_update_id_addr(struct work_struct * work)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 l2cap_chan_le_connect_reject(struct l2cap_chan * chan)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 l2cap_chan_ecred_connect_reject(struct l2cap_chan * chan)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 l2cap_chan_connect_reject(struct l2cap_chan * chan)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 l2cap_chan_close(struct l2cap_chan * chan,int reason)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 l2cap_get_auth_type(struct l2cap_chan * chan)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 */ l2cap_chan_check_security(struct l2cap_chan * chan,bool initiator)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 l2cap_get_ident(struct l2cap_conn * conn)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 l2cap_send_cmd(struct l2cap_conn * conn,u8 ident,u8 code,u16 len,void * data)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 l2cap_do_send(struct l2cap_chan * chan,struct sk_buff * skb)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 __unpack_enhanced_control(u16 enh,struct l2cap_ctrl * control)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 __unpack_extended_control(u32 ext,struct l2cap_ctrl * control)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 __unpack_control(struct l2cap_chan * chan,struct sk_buff * skb)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 __pack_extended_control(struct l2cap_ctrl * control)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 __pack_enhanced_control(struct l2cap_ctrl * control)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 __pack_control(struct l2cap_chan * chan,struct l2cap_ctrl * control,struct sk_buff * skb)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 __ertm_hdr_size(struct l2cap_chan * chan)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 l2cap_create_sframe_pdu(struct l2cap_chan * chan,u32 control)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 l2cap_send_sframe(struct l2cap_chan * chan,struct l2cap_ctrl * control)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 l2cap_send_rr_or_rnr(struct l2cap_chan * chan,bool poll)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 __l2cap_no_conn_pending(struct l2cap_chan * chan)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 l2cap_send_conn_req(struct l2cap_chan * chan)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 l2cap_chan_ready(struct l2cap_chan * chan)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 l2cap_le_connect(struct l2cap_chan * chan)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 l2cap_ecred_defer_connect(struct l2cap_chan * chan,void * data)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 l2cap_ecred_connect(struct l2cap_chan * chan)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 l2cap_le_start(struct l2cap_chan * chan)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 l2cap_start_connection(struct l2cap_chan * chan)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 l2cap_request_info(struct l2cap_conn * conn)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 l2cap_check_enc_key_size(struct hci_conn * hcon)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 l2cap_do_start(struct l2cap_chan * chan)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 l2cap_mode_supported(__u8 mode,__u32 feat_mask)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 l2cap_send_disconn_req(struct l2cap_chan * chan,int err)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 ---- */ l2cap_conn_start(struct l2cap_conn * conn)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 l2cap_le_conn_ready(struct l2cap_conn * conn)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 l2cap_conn_ready(struct l2cap_conn * conn)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 */ l2cap_conn_unreliable(struct l2cap_conn * conn,int err)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 l2cap_info_timeout(struct work_struct * work)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 l2cap_register_user(struct l2cap_conn * conn,struct l2cap_user * user)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 l2cap_unregister_user(struct l2cap_conn * conn,struct l2cap_user * user)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 l2cap_unregister_all_users(struct l2cap_conn * conn)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 l2cap_conn_del(struct hci_conn * hcon,int err)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 l2cap_conn_free(struct kref * ref)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 l2cap_conn_get(struct l2cap_conn * conn)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 l2cap_conn_put(struct l2cap_conn * conn)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 */ l2cap_global_chan_by_psm(int state,__le16 psm,bdaddr_t * src,bdaddr_t * dst,u8 link_type)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 l2cap_monitor_timeout(struct work_struct * work)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 l2cap_retrans_timeout(struct work_struct * work)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 l2cap_streaming_send(struct l2cap_chan * chan,struct sk_buff_head * skbs)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 l2cap_ertm_send(struct l2cap_chan * chan)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 l2cap_ertm_resend(struct l2cap_chan * chan)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 l2cap_retransmit(struct l2cap_chan * chan,struct l2cap_ctrl * control)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 l2cap_retransmit_all(struct l2cap_chan * chan,struct l2cap_ctrl * control)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 l2cap_send_ack(struct l2cap_chan * chan)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 l2cap_skbuff_fromiovec(struct l2cap_chan * chan,struct msghdr * msg,int len,int count,struct sk_buff * skb)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 l2cap_create_connless_pdu(struct l2cap_chan * chan,struct msghdr * msg,size_t len)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 l2cap_create_basic_pdu(struct l2cap_chan * chan,struct msghdr * msg,size_t len)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 l2cap_create_iframe_pdu(struct l2cap_chan * chan,struct msghdr * msg,size_t len,u16 sdulen)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 l2cap_segment_sdu(struct l2cap_chan * chan,struct sk_buff_head * seg_queue,struct msghdr * msg,size_t len)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 l2cap_create_le_flowctl_pdu(struct l2cap_chan * chan,struct msghdr * msg,size_t len,u16 sdulen)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 l2cap_segment_le_sdu(struct l2cap_chan * chan,struct sk_buff_head * seg_queue,struct msghdr * msg,size_t len)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 l2cap_le_flowctl_send(struct l2cap_chan * chan)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 l2cap_chan_send(struct l2cap_chan * chan,struct msghdr * msg,size_t len)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 l2cap_send_srej(struct l2cap_chan * chan,u16 txseq)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 l2cap_send_srej_tail(struct l2cap_chan * chan)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 l2cap_send_srej_list(struct l2cap_chan * chan,u16 txseq)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 l2cap_process_reqseq(struct l2cap_chan * chan,u16 reqseq)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 l2cap_abort_rx_srej_sent(struct l2cap_chan * chan)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 l2cap_tx_state_xmit(struct l2cap_chan * chan,struct l2cap_ctrl * control,struct sk_buff_head * skbs,u8 event)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 l2cap_tx_state_wait_f(struct l2cap_chan * chan,struct l2cap_ctrl * control,struct sk_buff_head * skbs,u8 event)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 l2cap_tx(struct l2cap_chan * chan,struct l2cap_ctrl * control,struct sk_buff_head * skbs,u8 event)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 l2cap_pass_to_tx(struct l2cap_chan * chan,struct l2cap_ctrl * control)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 l2cap_pass_to_tx_fbit(struct l2cap_chan * chan,struct l2cap_ctrl * control)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 */ l2cap_raw_recv(struct l2cap_conn * conn,struct sk_buff * skb)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 ---- */ l2cap_build_cmd(struct l2cap_conn * conn,u8 code,u8 ident,u16 dlen,void * data)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 l2cap_get_conf_opt(void ** ptr,int * type,int * olen,unsigned long * val)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 l2cap_add_conf_opt(void ** ptr,u8 type,u8 len,unsigned long val,size_t size)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 l2cap_add_opt_efs(void ** ptr,struct l2cap_chan * chan,size_t size)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 l2cap_ack_timeout(struct work_struct * work)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 l2cap_ertm_init(struct l2cap_chan * chan)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 l2cap_select_mode(__u8 mode,__u16 remote_feat_mask)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 __l2cap_ews_supported(struct l2cap_conn * conn)3173 static inline bool __l2cap_ews_supported(struct l2cap_conn *conn) 3174 { 3175 return (conn->feat_mask & L2CAP_FEAT_EXT_WINDOW); 3176 } 3177 __l2cap_efs_supported(struct l2cap_conn * conn)3178 static inline bool __l2cap_efs_supported(struct l2cap_conn *conn) 3179 { 3180 return (conn->feat_mask & L2CAP_FEAT_EXT_FLOW); 3181 } 3182 __l2cap_set_ertm_timeouts(struct l2cap_chan * chan,struct l2cap_conf_rfc * rfc)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 l2cap_txwin_setup(struct l2cap_chan * chan)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 l2cap_mtu_auto(struct l2cap_chan * chan)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 l2cap_build_conf_req(struct l2cap_chan * chan,void * data,size_t data_size)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 l2cap_parse_conf_req(struct l2cap_chan * chan,void * data,size_t data_size)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 l2cap_parse_conf_rsp(struct l2cap_chan * chan,void * rsp,int len,void * data,size_t size,u16 * result)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 l2cap_build_conf_rsp(struct l2cap_chan * chan,void * data,u16 result,u16 flags)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 __l2cap_le_connect_rsp_defer(struct l2cap_chan * chan)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 l2cap_ecred_list_defer(struct l2cap_chan * chan,void * data)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 l2cap_ecred_rsp_defer(struct l2cap_chan * chan,void * data)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 __l2cap_ecred_conn_rsp_defer(struct l2cap_chan * chan)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 __l2cap_connect_rsp_defer(struct l2cap_chan * chan)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 l2cap_conf_rfc_get(struct l2cap_chan * chan,void * rsp,int len)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 l2cap_command_rej(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)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 l2cap_connect(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u8 * data,u8 rsp_code)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 l2cap_connect_req(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4066 static int l2cap_connect_req(struct l2cap_conn *conn, 4067 struct l2cap_cmd_hdr *cmd, u16 cmd_len, u8 *data) 4068 { 4069 if (cmd_len < sizeof(struct l2cap_conn_req)) 4070 return -EPROTO; 4071 4072 l2cap_connect(conn, cmd, data, L2CAP_CONN_RSP); 4073 return 0; 4074 } 4075 l2cap_connect_create_rsp(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4076 static int l2cap_connect_create_rsp(struct l2cap_conn *conn, 4077 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4078 u8 *data) 4079 { 4080 struct l2cap_conn_rsp *rsp = (struct l2cap_conn_rsp *) data; 4081 u16 scid, dcid, result, status; 4082 struct l2cap_chan *chan; 4083 u8 req[128]; 4084 int err; 4085 4086 if (cmd_len < sizeof(*rsp)) 4087 return -EPROTO; 4088 4089 scid = __le16_to_cpu(rsp->scid); 4090 dcid = __le16_to_cpu(rsp->dcid); 4091 result = __le16_to_cpu(rsp->result); 4092 status = __le16_to_cpu(rsp->status); 4093 4094 if (result == L2CAP_CR_SUCCESS && (dcid < L2CAP_CID_DYN_START || 4095 dcid > L2CAP_CID_DYN_END)) 4096 return -EPROTO; 4097 4098 BT_DBG("dcid 0x%4.4x scid 0x%4.4x result 0x%2.2x status 0x%2.2x", 4099 dcid, scid, result, status); 4100 4101 mutex_lock(&conn->chan_lock); 4102 4103 if (scid) { 4104 chan = __l2cap_get_chan_by_scid(conn, scid); 4105 if (!chan) { 4106 err = -EBADSLT; 4107 goto unlock; 4108 } 4109 } else { 4110 chan = __l2cap_get_chan_by_ident(conn, cmd->ident); 4111 if (!chan) { 4112 err = -EBADSLT; 4113 goto unlock; 4114 } 4115 } 4116 4117 chan = l2cap_chan_hold_unless_zero(chan); 4118 if (!chan) { 4119 err = -EBADSLT; 4120 goto unlock; 4121 } 4122 4123 err = 0; 4124 4125 l2cap_chan_lock(chan); 4126 4127 switch (result) { 4128 case L2CAP_CR_SUCCESS: 4129 if (__l2cap_get_chan_by_dcid(conn, dcid)) { 4130 err = -EBADSLT; 4131 break; 4132 } 4133 4134 l2cap_state_change(chan, BT_CONFIG); 4135 chan->ident = 0; 4136 chan->dcid = dcid; 4137 clear_bit(CONF_CONNECT_PEND, &chan->conf_state); 4138 4139 if (test_and_set_bit(CONF_REQ_SENT, &chan->conf_state)) 4140 break; 4141 4142 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ, 4143 l2cap_build_conf_req(chan, req, sizeof(req)), req); 4144 chan->num_conf_req++; 4145 break; 4146 4147 case L2CAP_CR_PEND: 4148 set_bit(CONF_CONNECT_PEND, &chan->conf_state); 4149 break; 4150 4151 default: 4152 l2cap_chan_del(chan, ECONNREFUSED); 4153 break; 4154 } 4155 4156 l2cap_chan_unlock(chan); 4157 l2cap_chan_put(chan); 4158 4159 unlock: 4160 mutex_unlock(&conn->chan_lock); 4161 4162 return err; 4163 } 4164 set_default_fcs(struct l2cap_chan * chan)4165 static inline void set_default_fcs(struct l2cap_chan *chan) 4166 { 4167 /* FCS is enabled only in ERTM or streaming mode, if one or both 4168 * sides request it. 4169 */ 4170 if (chan->mode != L2CAP_MODE_ERTM && chan->mode != L2CAP_MODE_STREAMING) 4171 chan->fcs = L2CAP_FCS_NONE; 4172 else if (!test_bit(CONF_RECV_NO_FCS, &chan->conf_state)) 4173 chan->fcs = L2CAP_FCS_CRC16; 4174 } 4175 l2cap_send_efs_conf_rsp(struct l2cap_chan * chan,void * data,u8 ident,u16 flags)4176 static void l2cap_send_efs_conf_rsp(struct l2cap_chan *chan, void *data, 4177 u8 ident, u16 flags) 4178 { 4179 struct l2cap_conn *conn = chan->conn; 4180 4181 BT_DBG("conn %p chan %p ident %d flags 0x%4.4x", conn, chan, ident, 4182 flags); 4183 4184 clear_bit(CONF_LOC_CONF_PEND, &chan->conf_state); 4185 set_bit(CONF_OUTPUT_DONE, &chan->conf_state); 4186 4187 l2cap_send_cmd(conn, ident, L2CAP_CONF_RSP, 4188 l2cap_build_conf_rsp(chan, data, 4189 L2CAP_CONF_SUCCESS, flags), data); 4190 } 4191 cmd_reject_invalid_cid(struct l2cap_conn * conn,u8 ident,u16 scid,u16 dcid)4192 static void cmd_reject_invalid_cid(struct l2cap_conn *conn, u8 ident, 4193 u16 scid, u16 dcid) 4194 { 4195 struct l2cap_cmd_rej_cid rej; 4196 4197 rej.reason = cpu_to_le16(L2CAP_REJ_INVALID_CID); 4198 rej.scid = __cpu_to_le16(scid); 4199 rej.dcid = __cpu_to_le16(dcid); 4200 4201 l2cap_send_cmd(conn, ident, L2CAP_COMMAND_REJ, sizeof(rej), &rej); 4202 } 4203 l2cap_config_req(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4204 static inline int l2cap_config_req(struct l2cap_conn *conn, 4205 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4206 u8 *data) 4207 { 4208 struct l2cap_conf_req *req = (struct l2cap_conf_req *) data; 4209 u16 dcid, flags; 4210 u8 rsp[64]; 4211 struct l2cap_chan *chan; 4212 int len, err = 0; 4213 4214 if (cmd_len < sizeof(*req)) 4215 return -EPROTO; 4216 4217 dcid = __le16_to_cpu(req->dcid); 4218 flags = __le16_to_cpu(req->flags); 4219 4220 BT_DBG("dcid 0x%4.4x flags 0x%2.2x", dcid, flags); 4221 4222 chan = l2cap_get_chan_by_scid(conn, dcid); 4223 if (!chan) { 4224 cmd_reject_invalid_cid(conn, cmd->ident, dcid, 0); 4225 return 0; 4226 } 4227 4228 if (chan->state != BT_CONFIG && chan->state != BT_CONNECT2 && 4229 chan->state != BT_CONNECTED) { 4230 cmd_reject_invalid_cid(conn, cmd->ident, chan->scid, 4231 chan->dcid); 4232 goto unlock; 4233 } 4234 4235 /* Reject if config buffer is too small. */ 4236 len = cmd_len - sizeof(*req); 4237 if (chan->conf_len + len > sizeof(chan->conf_req)) { 4238 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP, 4239 l2cap_build_conf_rsp(chan, rsp, 4240 L2CAP_CONF_REJECT, flags), rsp); 4241 goto unlock; 4242 } 4243 4244 /* Store config. */ 4245 memcpy(chan->conf_req + chan->conf_len, req->data, len); 4246 chan->conf_len += len; 4247 4248 if (flags & L2CAP_CONF_FLAG_CONTINUATION) { 4249 /* Incomplete config. Send empty response. */ 4250 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP, 4251 l2cap_build_conf_rsp(chan, rsp, 4252 L2CAP_CONF_SUCCESS, flags), rsp); 4253 goto unlock; 4254 } 4255 4256 /* Complete config. */ 4257 len = l2cap_parse_conf_req(chan, rsp, sizeof(rsp)); 4258 if (len < 0) { 4259 l2cap_send_disconn_req(chan, ECONNRESET); 4260 goto unlock; 4261 } 4262 4263 chan->ident = cmd->ident; 4264 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP, len, rsp); 4265 if (chan->num_conf_rsp < L2CAP_CONF_MAX_CONF_RSP) 4266 chan->num_conf_rsp++; 4267 4268 /* Reset config buffer. */ 4269 chan->conf_len = 0; 4270 4271 if (!test_bit(CONF_OUTPUT_DONE, &chan->conf_state)) 4272 goto unlock; 4273 4274 if (test_bit(CONF_INPUT_DONE, &chan->conf_state)) { 4275 set_default_fcs(chan); 4276 4277 if (chan->mode == L2CAP_MODE_ERTM || 4278 chan->mode == L2CAP_MODE_STREAMING) 4279 err = l2cap_ertm_init(chan); 4280 4281 if (err < 0) 4282 l2cap_send_disconn_req(chan, -err); 4283 else 4284 l2cap_chan_ready(chan); 4285 4286 goto unlock; 4287 } 4288 4289 if (!test_and_set_bit(CONF_REQ_SENT, &chan->conf_state)) { 4290 u8 buf[64]; 4291 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ, 4292 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf); 4293 chan->num_conf_req++; 4294 } 4295 4296 /* Got Conf Rsp PENDING from remote side and assume we sent 4297 Conf Rsp PENDING in the code above */ 4298 if (test_bit(CONF_REM_CONF_PEND, &chan->conf_state) && 4299 test_bit(CONF_LOC_CONF_PEND, &chan->conf_state)) { 4300 4301 /* check compatibility */ 4302 4303 /* Send rsp for BR/EDR channel */ 4304 l2cap_send_efs_conf_rsp(chan, rsp, cmd->ident, flags); 4305 } 4306 4307 unlock: 4308 l2cap_chan_unlock(chan); 4309 l2cap_chan_put(chan); 4310 return err; 4311 } 4312 l2cap_config_rsp(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4313 static inline int l2cap_config_rsp(struct l2cap_conn *conn, 4314 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4315 u8 *data) 4316 { 4317 struct l2cap_conf_rsp *rsp = (struct l2cap_conf_rsp *)data; 4318 u16 scid, flags, result; 4319 struct l2cap_chan *chan; 4320 int len = cmd_len - sizeof(*rsp); 4321 int err = 0; 4322 4323 if (cmd_len < sizeof(*rsp)) 4324 return -EPROTO; 4325 4326 scid = __le16_to_cpu(rsp->scid); 4327 flags = __le16_to_cpu(rsp->flags); 4328 result = __le16_to_cpu(rsp->result); 4329 4330 BT_DBG("scid 0x%4.4x flags 0x%2.2x result 0x%2.2x len %d", scid, flags, 4331 result, len); 4332 4333 chan = l2cap_get_chan_by_scid(conn, scid); 4334 if (!chan) 4335 return 0; 4336 4337 switch (result) { 4338 case L2CAP_CONF_SUCCESS: 4339 l2cap_conf_rfc_get(chan, rsp->data, len); 4340 clear_bit(CONF_REM_CONF_PEND, &chan->conf_state); 4341 break; 4342 4343 case L2CAP_CONF_PENDING: 4344 set_bit(CONF_REM_CONF_PEND, &chan->conf_state); 4345 4346 if (test_bit(CONF_LOC_CONF_PEND, &chan->conf_state)) { 4347 char buf[64]; 4348 4349 len = l2cap_parse_conf_rsp(chan, rsp->data, len, 4350 buf, sizeof(buf), &result); 4351 if (len < 0) { 4352 l2cap_send_disconn_req(chan, ECONNRESET); 4353 goto done; 4354 } 4355 4356 l2cap_send_efs_conf_rsp(chan, buf, cmd->ident, 0); 4357 } 4358 goto done; 4359 4360 case L2CAP_CONF_UNKNOWN: 4361 case L2CAP_CONF_UNACCEPT: 4362 if (chan->num_conf_rsp <= L2CAP_CONF_MAX_CONF_RSP) { 4363 char req[64]; 4364 4365 if (len > sizeof(req) - sizeof(struct l2cap_conf_req)) { 4366 l2cap_send_disconn_req(chan, ECONNRESET); 4367 goto done; 4368 } 4369 4370 /* throw out any old stored conf requests */ 4371 result = L2CAP_CONF_SUCCESS; 4372 len = l2cap_parse_conf_rsp(chan, rsp->data, len, 4373 req, sizeof(req), &result); 4374 if (len < 0) { 4375 l2cap_send_disconn_req(chan, ECONNRESET); 4376 goto done; 4377 } 4378 4379 l2cap_send_cmd(conn, l2cap_get_ident(conn), 4380 L2CAP_CONF_REQ, len, req); 4381 chan->num_conf_req++; 4382 if (result != L2CAP_CONF_SUCCESS) 4383 goto done; 4384 break; 4385 } 4386 fallthrough; 4387 4388 default: 4389 l2cap_chan_set_err(chan, ECONNRESET); 4390 4391 __set_chan_timer(chan, L2CAP_DISC_REJ_TIMEOUT); 4392 l2cap_send_disconn_req(chan, ECONNRESET); 4393 goto done; 4394 } 4395 4396 if (flags & L2CAP_CONF_FLAG_CONTINUATION) 4397 goto done; 4398 4399 set_bit(CONF_INPUT_DONE, &chan->conf_state); 4400 4401 if (test_bit(CONF_OUTPUT_DONE, &chan->conf_state)) { 4402 set_default_fcs(chan); 4403 4404 if (chan->mode == L2CAP_MODE_ERTM || 4405 chan->mode == L2CAP_MODE_STREAMING) 4406 err = l2cap_ertm_init(chan); 4407 4408 if (err < 0) 4409 l2cap_send_disconn_req(chan, -err); 4410 else 4411 l2cap_chan_ready(chan); 4412 } 4413 4414 done: 4415 l2cap_chan_unlock(chan); 4416 l2cap_chan_put(chan); 4417 return err; 4418 } 4419 l2cap_disconnect_req(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4420 static inline int l2cap_disconnect_req(struct l2cap_conn *conn, 4421 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4422 u8 *data) 4423 { 4424 struct l2cap_disconn_req *req = (struct l2cap_disconn_req *) data; 4425 struct l2cap_disconn_rsp rsp; 4426 u16 dcid, scid; 4427 struct l2cap_chan *chan; 4428 4429 if (cmd_len != sizeof(*req)) 4430 return -EPROTO; 4431 4432 scid = __le16_to_cpu(req->scid); 4433 dcid = __le16_to_cpu(req->dcid); 4434 4435 BT_DBG("scid 0x%4.4x dcid 0x%4.4x", scid, dcid); 4436 4437 chan = l2cap_get_chan_by_scid(conn, dcid); 4438 if (!chan) { 4439 cmd_reject_invalid_cid(conn, cmd->ident, dcid, scid); 4440 return 0; 4441 } 4442 4443 rsp.dcid = cpu_to_le16(chan->scid); 4444 rsp.scid = cpu_to_le16(chan->dcid); 4445 l2cap_send_cmd(conn, cmd->ident, L2CAP_DISCONN_RSP, sizeof(rsp), &rsp); 4446 4447 chan->ops->set_shutdown(chan); 4448 4449 l2cap_chan_unlock(chan); 4450 mutex_lock(&conn->chan_lock); 4451 l2cap_chan_lock(chan); 4452 l2cap_chan_del(chan, ECONNRESET); 4453 mutex_unlock(&conn->chan_lock); 4454 4455 chan->ops->close(chan); 4456 4457 l2cap_chan_unlock(chan); 4458 l2cap_chan_put(chan); 4459 4460 return 0; 4461 } 4462 l2cap_disconnect_rsp(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4463 static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn, 4464 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4465 u8 *data) 4466 { 4467 struct l2cap_disconn_rsp *rsp = (struct l2cap_disconn_rsp *) data; 4468 u16 dcid, scid; 4469 struct l2cap_chan *chan; 4470 4471 if (cmd_len != sizeof(*rsp)) 4472 return -EPROTO; 4473 4474 scid = __le16_to_cpu(rsp->scid); 4475 dcid = __le16_to_cpu(rsp->dcid); 4476 4477 BT_DBG("dcid 0x%4.4x scid 0x%4.4x", dcid, scid); 4478 4479 chan = l2cap_get_chan_by_scid(conn, scid); 4480 if (!chan) { 4481 return 0; 4482 } 4483 4484 if (chan->state != BT_DISCONN) { 4485 l2cap_chan_unlock(chan); 4486 l2cap_chan_put(chan); 4487 return 0; 4488 } 4489 4490 l2cap_chan_unlock(chan); 4491 mutex_lock(&conn->chan_lock); 4492 l2cap_chan_lock(chan); 4493 l2cap_chan_del(chan, 0); 4494 mutex_unlock(&conn->chan_lock); 4495 4496 chan->ops->close(chan); 4497 4498 l2cap_chan_unlock(chan); 4499 l2cap_chan_put(chan); 4500 4501 return 0; 4502 } 4503 l2cap_information_req(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4504 static inline int l2cap_information_req(struct l2cap_conn *conn, 4505 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4506 u8 *data) 4507 { 4508 struct l2cap_info_req *req = (struct l2cap_info_req *) data; 4509 u16 type; 4510 4511 if (cmd_len != sizeof(*req)) 4512 return -EPROTO; 4513 4514 type = __le16_to_cpu(req->type); 4515 4516 BT_DBG("type 0x%4.4x", type); 4517 4518 if (type == L2CAP_IT_FEAT_MASK) { 4519 u8 buf[8]; 4520 u32 feat_mask = l2cap_feat_mask; 4521 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) buf; 4522 rsp->type = cpu_to_le16(L2CAP_IT_FEAT_MASK); 4523 rsp->result = cpu_to_le16(L2CAP_IR_SUCCESS); 4524 if (!disable_ertm) 4525 feat_mask |= L2CAP_FEAT_ERTM | L2CAP_FEAT_STREAMING 4526 | L2CAP_FEAT_FCS; 4527 4528 put_unaligned_le32(feat_mask, rsp->data); 4529 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(buf), 4530 buf); 4531 } else if (type == L2CAP_IT_FIXED_CHAN) { 4532 u8 buf[12]; 4533 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) buf; 4534 4535 rsp->type = cpu_to_le16(L2CAP_IT_FIXED_CHAN); 4536 rsp->result = cpu_to_le16(L2CAP_IR_SUCCESS); 4537 rsp->data[0] = conn->local_fixed_chan; 4538 memset(rsp->data + 1, 0, 7); 4539 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(buf), 4540 buf); 4541 } else { 4542 struct l2cap_info_rsp rsp; 4543 rsp.type = cpu_to_le16(type); 4544 rsp.result = cpu_to_le16(L2CAP_IR_NOTSUPP); 4545 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(rsp), 4546 &rsp); 4547 } 4548 4549 return 0; 4550 } 4551 l2cap_information_rsp(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4552 static inline int l2cap_information_rsp(struct l2cap_conn *conn, 4553 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4554 u8 *data) 4555 { 4556 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) data; 4557 u16 type, result; 4558 4559 if (cmd_len < sizeof(*rsp)) 4560 return -EPROTO; 4561 4562 type = __le16_to_cpu(rsp->type); 4563 result = __le16_to_cpu(rsp->result); 4564 4565 BT_DBG("type 0x%4.4x result 0x%2.2x", type, result); 4566 4567 /* L2CAP Info req/rsp are unbound to channels, add extra checks */ 4568 if (cmd->ident != conn->info_ident || 4569 conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE) 4570 return 0; 4571 4572 cancel_delayed_work(&conn->info_timer); 4573 4574 if (result != L2CAP_IR_SUCCESS) { 4575 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE; 4576 conn->info_ident = 0; 4577 4578 l2cap_conn_start(conn); 4579 4580 return 0; 4581 } 4582 4583 switch (type) { 4584 case L2CAP_IT_FEAT_MASK: 4585 conn->feat_mask = get_unaligned_le32(rsp->data); 4586 4587 if (conn->feat_mask & L2CAP_FEAT_FIXED_CHAN) { 4588 struct l2cap_info_req req; 4589 req.type = cpu_to_le16(L2CAP_IT_FIXED_CHAN); 4590 4591 conn->info_ident = l2cap_get_ident(conn); 4592 4593 l2cap_send_cmd(conn, conn->info_ident, 4594 L2CAP_INFO_REQ, sizeof(req), &req); 4595 } else { 4596 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE; 4597 conn->info_ident = 0; 4598 4599 l2cap_conn_start(conn); 4600 } 4601 break; 4602 4603 case L2CAP_IT_FIXED_CHAN: 4604 conn->remote_fixed_chan = rsp->data[0]; 4605 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE; 4606 conn->info_ident = 0; 4607 4608 l2cap_conn_start(conn); 4609 break; 4610 } 4611 4612 return 0; 4613 } 4614 l2cap_conn_param_update_req(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4615 static inline int l2cap_conn_param_update_req(struct l2cap_conn *conn, 4616 struct l2cap_cmd_hdr *cmd, 4617 u16 cmd_len, u8 *data) 4618 { 4619 struct hci_conn *hcon = conn->hcon; 4620 struct l2cap_conn_param_update_req *req; 4621 struct l2cap_conn_param_update_rsp rsp; 4622 u16 min, max, latency, to_multiplier; 4623 int err; 4624 4625 if (hcon->role != HCI_ROLE_MASTER) 4626 return -EINVAL; 4627 4628 if (cmd_len != sizeof(struct l2cap_conn_param_update_req)) 4629 return -EPROTO; 4630 4631 req = (struct l2cap_conn_param_update_req *) data; 4632 min = __le16_to_cpu(req->min); 4633 max = __le16_to_cpu(req->max); 4634 latency = __le16_to_cpu(req->latency); 4635 to_multiplier = __le16_to_cpu(req->to_multiplier); 4636 4637 BT_DBG("min 0x%4.4x max 0x%4.4x latency: 0x%4.4x Timeout: 0x%4.4x", 4638 min, max, latency, to_multiplier); 4639 4640 memset(&rsp, 0, sizeof(rsp)); 4641 4642 err = hci_check_conn_params(min, max, latency, to_multiplier); 4643 if (err) 4644 rsp.result = cpu_to_le16(L2CAP_CONN_PARAM_REJECTED); 4645 else 4646 rsp.result = cpu_to_le16(L2CAP_CONN_PARAM_ACCEPTED); 4647 4648 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONN_PARAM_UPDATE_RSP, 4649 sizeof(rsp), &rsp); 4650 4651 if (!err) { 4652 u8 store_hint; 4653 4654 store_hint = hci_le_conn_update(hcon, min, max, latency, 4655 to_multiplier); 4656 mgmt_new_conn_param(hcon->hdev, &hcon->dst, hcon->dst_type, 4657 store_hint, min, max, latency, 4658 to_multiplier); 4659 4660 } 4661 4662 return 0; 4663 } 4664 l2cap_le_connect_rsp(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4665 static int l2cap_le_connect_rsp(struct l2cap_conn *conn, 4666 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4667 u8 *data) 4668 { 4669 struct l2cap_le_conn_rsp *rsp = (struct l2cap_le_conn_rsp *) data; 4670 struct hci_conn *hcon = conn->hcon; 4671 u16 dcid, mtu, mps, credits, result; 4672 struct l2cap_chan *chan; 4673 int err, sec_level; 4674 4675 if (cmd_len < sizeof(*rsp)) 4676 return -EPROTO; 4677 4678 dcid = __le16_to_cpu(rsp->dcid); 4679 mtu = __le16_to_cpu(rsp->mtu); 4680 mps = __le16_to_cpu(rsp->mps); 4681 credits = __le16_to_cpu(rsp->credits); 4682 result = __le16_to_cpu(rsp->result); 4683 4684 if (result == L2CAP_CR_LE_SUCCESS && (mtu < 23 || mps < 23 || 4685 dcid < L2CAP_CID_DYN_START || 4686 dcid > L2CAP_CID_LE_DYN_END)) 4687 return -EPROTO; 4688 4689 BT_DBG("dcid 0x%4.4x mtu %u mps %u credits %u result 0x%2.2x", 4690 dcid, mtu, mps, credits, result); 4691 4692 mutex_lock(&conn->chan_lock); 4693 4694 chan = __l2cap_get_chan_by_ident(conn, cmd->ident); 4695 if (!chan) { 4696 err = -EBADSLT; 4697 goto unlock; 4698 } 4699 4700 err = 0; 4701 4702 l2cap_chan_lock(chan); 4703 4704 switch (result) { 4705 case L2CAP_CR_LE_SUCCESS: 4706 if (__l2cap_get_chan_by_dcid(conn, dcid)) { 4707 err = -EBADSLT; 4708 break; 4709 } 4710 4711 chan->ident = 0; 4712 chan->dcid = dcid; 4713 chan->omtu = mtu; 4714 chan->remote_mps = mps; 4715 chan->tx_credits = credits; 4716 l2cap_chan_ready(chan); 4717 break; 4718 4719 case L2CAP_CR_LE_AUTHENTICATION: 4720 case L2CAP_CR_LE_ENCRYPTION: 4721 /* If we already have MITM protection we can't do 4722 * anything. 4723 */ 4724 if (hcon->sec_level > BT_SECURITY_MEDIUM) { 4725 l2cap_chan_del(chan, ECONNREFUSED); 4726 break; 4727 } 4728 4729 sec_level = hcon->sec_level + 1; 4730 if (chan->sec_level < sec_level) 4731 chan->sec_level = sec_level; 4732 4733 /* We'll need to send a new Connect Request */ 4734 clear_bit(FLAG_LE_CONN_REQ_SENT, &chan->flags); 4735 4736 smp_conn_security(hcon, chan->sec_level); 4737 break; 4738 4739 default: 4740 l2cap_chan_del(chan, ECONNREFUSED); 4741 break; 4742 } 4743 4744 l2cap_chan_unlock(chan); 4745 4746 unlock: 4747 mutex_unlock(&conn->chan_lock); 4748 4749 return err; 4750 } 4751 l2cap_bredr_sig_cmd(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4752 static inline int l2cap_bredr_sig_cmd(struct l2cap_conn *conn, 4753 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4754 u8 *data) 4755 { 4756 int err = 0; 4757 4758 switch (cmd->code) { 4759 case L2CAP_COMMAND_REJ: 4760 l2cap_command_rej(conn, cmd, cmd_len, data); 4761 break; 4762 4763 case L2CAP_CONN_REQ: 4764 err = l2cap_connect_req(conn, cmd, cmd_len, data); 4765 break; 4766 4767 case L2CAP_CONN_RSP: 4768 l2cap_connect_create_rsp(conn, cmd, cmd_len, data); 4769 break; 4770 4771 case L2CAP_CONF_REQ: 4772 err = l2cap_config_req(conn, cmd, cmd_len, data); 4773 break; 4774 4775 case L2CAP_CONF_RSP: 4776 l2cap_config_rsp(conn, cmd, cmd_len, data); 4777 break; 4778 4779 case L2CAP_DISCONN_REQ: 4780 err = l2cap_disconnect_req(conn, cmd, cmd_len, data); 4781 break; 4782 4783 case L2CAP_DISCONN_RSP: 4784 l2cap_disconnect_rsp(conn, cmd, cmd_len, data); 4785 break; 4786 4787 case L2CAP_ECHO_REQ: 4788 l2cap_send_cmd(conn, cmd->ident, L2CAP_ECHO_RSP, cmd_len, data); 4789 break; 4790 4791 case L2CAP_ECHO_RSP: 4792 break; 4793 4794 case L2CAP_INFO_REQ: 4795 err = l2cap_information_req(conn, cmd, cmd_len, data); 4796 break; 4797 4798 case L2CAP_INFO_RSP: 4799 l2cap_information_rsp(conn, cmd, cmd_len, data); 4800 break; 4801 4802 default: 4803 BT_ERR("Unknown BR/EDR signaling command 0x%2.2x", cmd->code); 4804 err = -EINVAL; 4805 break; 4806 } 4807 4808 return err; 4809 } 4810 l2cap_le_connect_req(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4811 static int l2cap_le_connect_req(struct l2cap_conn *conn, 4812 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4813 u8 *data) 4814 { 4815 struct l2cap_le_conn_req *req = (struct l2cap_le_conn_req *) data; 4816 struct l2cap_le_conn_rsp rsp; 4817 struct l2cap_chan *chan, *pchan; 4818 u16 dcid, scid, credits, mtu, mps; 4819 __le16 psm; 4820 u8 result; 4821 4822 if (cmd_len != sizeof(*req)) 4823 return -EPROTO; 4824 4825 scid = __le16_to_cpu(req->scid); 4826 mtu = __le16_to_cpu(req->mtu); 4827 mps = __le16_to_cpu(req->mps); 4828 psm = req->psm; 4829 dcid = 0; 4830 credits = 0; 4831 4832 if (mtu < 23 || mps < 23) 4833 return -EPROTO; 4834 4835 BT_DBG("psm 0x%2.2x scid 0x%4.4x mtu %u mps %u", __le16_to_cpu(psm), 4836 scid, mtu, mps); 4837 4838 /* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A 4839 * page 1059: 4840 * 4841 * Valid range: 0x0001-0x00ff 4842 * 4843 * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges 4844 */ 4845 if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) { 4846 result = L2CAP_CR_LE_BAD_PSM; 4847 chan = NULL; 4848 goto response; 4849 } 4850 4851 /* Check if we have socket listening on psm */ 4852 pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src, 4853 &conn->hcon->dst, LE_LINK); 4854 if (!pchan) { 4855 result = L2CAP_CR_LE_BAD_PSM; 4856 chan = NULL; 4857 goto response; 4858 } 4859 4860 mutex_lock(&conn->chan_lock); 4861 l2cap_chan_lock(pchan); 4862 4863 if (!smp_sufficient_security(conn->hcon, pchan->sec_level, 4864 SMP_ALLOW_STK)) { 4865 result = L2CAP_CR_LE_AUTHENTICATION; 4866 chan = NULL; 4867 goto response_unlock; 4868 } 4869 4870 /* Check for valid dynamic CID range */ 4871 if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_LE_DYN_END) { 4872 result = L2CAP_CR_LE_INVALID_SCID; 4873 chan = NULL; 4874 goto response_unlock; 4875 } 4876 4877 /* Check if we already have channel with that dcid */ 4878 if (__l2cap_get_chan_by_dcid(conn, scid)) { 4879 result = L2CAP_CR_LE_SCID_IN_USE; 4880 chan = NULL; 4881 goto response_unlock; 4882 } 4883 4884 chan = pchan->ops->new_connection(pchan); 4885 if (!chan) { 4886 result = L2CAP_CR_LE_NO_MEM; 4887 goto response_unlock; 4888 } 4889 4890 bacpy(&chan->src, &conn->hcon->src); 4891 bacpy(&chan->dst, &conn->hcon->dst); 4892 chan->src_type = bdaddr_src_type(conn->hcon); 4893 chan->dst_type = bdaddr_dst_type(conn->hcon); 4894 chan->psm = psm; 4895 chan->dcid = scid; 4896 chan->omtu = mtu; 4897 chan->remote_mps = mps; 4898 4899 __l2cap_chan_add(conn, chan); 4900 4901 l2cap_le_flowctl_init(chan, __le16_to_cpu(req->credits)); 4902 4903 dcid = chan->scid; 4904 credits = chan->rx_credits; 4905 4906 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan)); 4907 4908 chan->ident = cmd->ident; 4909 4910 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) { 4911 l2cap_state_change(chan, BT_CONNECT2); 4912 /* The following result value is actually not defined 4913 * for LE CoC but we use it to let the function know 4914 * that it should bail out after doing its cleanup 4915 * instead of sending a response. 4916 */ 4917 result = L2CAP_CR_PEND; 4918 chan->ops->defer(chan); 4919 } else { 4920 l2cap_chan_ready(chan); 4921 result = L2CAP_CR_LE_SUCCESS; 4922 } 4923 4924 response_unlock: 4925 l2cap_chan_unlock(pchan); 4926 mutex_unlock(&conn->chan_lock); 4927 l2cap_chan_put(pchan); 4928 4929 if (result == L2CAP_CR_PEND) 4930 return 0; 4931 4932 response: 4933 if (chan) { 4934 rsp.mtu = cpu_to_le16(chan->imtu); 4935 rsp.mps = cpu_to_le16(chan->mps); 4936 } else { 4937 rsp.mtu = 0; 4938 rsp.mps = 0; 4939 } 4940 4941 rsp.dcid = cpu_to_le16(dcid); 4942 rsp.credits = cpu_to_le16(credits); 4943 rsp.result = cpu_to_le16(result); 4944 4945 l2cap_send_cmd(conn, cmd->ident, L2CAP_LE_CONN_RSP, sizeof(rsp), &rsp); 4946 4947 return 0; 4948 } 4949 l2cap_le_credits(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4950 static inline int l2cap_le_credits(struct l2cap_conn *conn, 4951 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4952 u8 *data) 4953 { 4954 struct l2cap_le_credits *pkt; 4955 struct l2cap_chan *chan; 4956 u16 cid, credits, max_credits; 4957 4958 if (cmd_len != sizeof(*pkt)) 4959 return -EPROTO; 4960 4961 pkt = (struct l2cap_le_credits *) data; 4962 cid = __le16_to_cpu(pkt->cid); 4963 credits = __le16_to_cpu(pkt->credits); 4964 4965 BT_DBG("cid 0x%4.4x credits 0x%4.4x", cid, credits); 4966 4967 chan = l2cap_get_chan_by_dcid(conn, cid); 4968 if (!chan) 4969 return -EBADSLT; 4970 4971 max_credits = LE_FLOWCTL_MAX_CREDITS - chan->tx_credits; 4972 if (credits > max_credits) { 4973 BT_ERR("LE credits overflow"); 4974 l2cap_send_disconn_req(chan, ECONNRESET); 4975 4976 /* Return 0 so that we don't trigger an unnecessary 4977 * command reject packet. 4978 */ 4979 goto unlock; 4980 } 4981 4982 chan->tx_credits += credits; 4983 4984 /* Resume sending */ 4985 l2cap_le_flowctl_send(chan); 4986 4987 if (chan->tx_credits) 4988 chan->ops->resume(chan); 4989 4990 unlock: 4991 l2cap_chan_unlock(chan); 4992 l2cap_chan_put(chan); 4993 4994 return 0; 4995 } 4996 l2cap_ecred_conn_req(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4997 static inline int l2cap_ecred_conn_req(struct l2cap_conn *conn, 4998 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 4999 u8 *data) 5000 { 5001 struct l2cap_ecred_conn_req *req = (void *) data; 5002 DEFINE_RAW_FLEX(struct l2cap_ecred_conn_rsp, pdu, dcid, L2CAP_ECRED_MAX_CID); 5003 struct l2cap_chan *chan, *pchan; 5004 u16 mtu, mps; 5005 __le16 psm; 5006 u8 result, len = 0; 5007 int i, num_scid; 5008 bool defer = false; 5009 5010 if (!enable_ecred) 5011 return -EINVAL; 5012 5013 if (cmd_len < sizeof(*req) || (cmd_len - sizeof(*req)) % sizeof(u16)) { 5014 result = L2CAP_CR_LE_INVALID_PARAMS; 5015 goto response; 5016 } 5017 5018 cmd_len -= sizeof(*req); 5019 num_scid = cmd_len / sizeof(u16); 5020 5021 if (num_scid > L2CAP_ECRED_MAX_CID) { 5022 result = L2CAP_CR_LE_INVALID_PARAMS; 5023 goto response; 5024 } 5025 5026 mtu = __le16_to_cpu(req->mtu); 5027 mps = __le16_to_cpu(req->mps); 5028 5029 if (mtu < L2CAP_ECRED_MIN_MTU || mps < L2CAP_ECRED_MIN_MPS) { 5030 result = L2CAP_CR_LE_UNACCEPT_PARAMS; 5031 goto response; 5032 } 5033 5034 psm = req->psm; 5035 5036 /* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A 5037 * page 1059: 5038 * 5039 * Valid range: 0x0001-0x00ff 5040 * 5041 * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges 5042 */ 5043 if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) { 5044 result = L2CAP_CR_LE_BAD_PSM; 5045 goto response; 5046 } 5047 5048 BT_DBG("psm 0x%2.2x mtu %u mps %u", __le16_to_cpu(psm), mtu, mps); 5049 5050 memset(pdu, 0, sizeof(*pdu)); 5051 5052 /* Check if we have socket listening on psm */ 5053 pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src, 5054 &conn->hcon->dst, LE_LINK); 5055 if (!pchan) { 5056 result = L2CAP_CR_LE_BAD_PSM; 5057 goto response; 5058 } 5059 5060 mutex_lock(&conn->chan_lock); 5061 l2cap_chan_lock(pchan); 5062 5063 if (!smp_sufficient_security(conn->hcon, pchan->sec_level, 5064 SMP_ALLOW_STK)) { 5065 result = L2CAP_CR_LE_AUTHENTICATION; 5066 goto unlock; 5067 } 5068 5069 result = L2CAP_CR_LE_SUCCESS; 5070 5071 for (i = 0; i < num_scid; i++) { 5072 u16 scid = __le16_to_cpu(req->scid[i]); 5073 5074 BT_DBG("scid[%d] 0x%4.4x", i, scid); 5075 5076 pdu->dcid[i] = 0x0000; 5077 len += sizeof(*pdu->dcid); 5078 5079 /* Check for valid dynamic CID range */ 5080 if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_LE_DYN_END) { 5081 result = L2CAP_CR_LE_INVALID_SCID; 5082 continue; 5083 } 5084 5085 /* Check if we already have channel with that dcid */ 5086 if (__l2cap_get_chan_by_dcid(conn, scid)) { 5087 result = L2CAP_CR_LE_SCID_IN_USE; 5088 continue; 5089 } 5090 5091 chan = pchan->ops->new_connection(pchan); 5092 if (!chan) { 5093 result = L2CAP_CR_LE_NO_MEM; 5094 continue; 5095 } 5096 5097 bacpy(&chan->src, &conn->hcon->src); 5098 bacpy(&chan->dst, &conn->hcon->dst); 5099 chan->src_type = bdaddr_src_type(conn->hcon); 5100 chan->dst_type = bdaddr_dst_type(conn->hcon); 5101 chan->psm = psm; 5102 chan->dcid = scid; 5103 chan->omtu = mtu; 5104 chan->remote_mps = mps; 5105 5106 __l2cap_chan_add(conn, chan); 5107 5108 l2cap_ecred_init(chan, __le16_to_cpu(req->credits)); 5109 5110 /* Init response */ 5111 if (!pdu->credits) { 5112 pdu->mtu = cpu_to_le16(chan->imtu); 5113 pdu->mps = cpu_to_le16(chan->mps); 5114 pdu->credits = cpu_to_le16(chan->rx_credits); 5115 } 5116 5117 pdu->dcid[i] = cpu_to_le16(chan->scid); 5118 5119 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan)); 5120 5121 chan->ident = cmd->ident; 5122 chan->mode = L2CAP_MODE_EXT_FLOWCTL; 5123 5124 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) { 5125 l2cap_state_change(chan, BT_CONNECT2); 5126 defer = true; 5127 chan->ops->defer(chan); 5128 } else { 5129 l2cap_chan_ready(chan); 5130 } 5131 } 5132 5133 unlock: 5134 l2cap_chan_unlock(pchan); 5135 mutex_unlock(&conn->chan_lock); 5136 l2cap_chan_put(pchan); 5137 5138 response: 5139 pdu->result = cpu_to_le16(result); 5140 5141 if (defer) 5142 return 0; 5143 5144 l2cap_send_cmd(conn, cmd->ident, L2CAP_ECRED_CONN_RSP, 5145 sizeof(*pdu) + len, pdu); 5146 5147 return 0; 5148 } 5149 l2cap_ecred_conn_rsp(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)5150 static inline int l2cap_ecred_conn_rsp(struct l2cap_conn *conn, 5151 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 5152 u8 *data) 5153 { 5154 struct l2cap_ecred_conn_rsp *rsp = (void *) data; 5155 struct hci_conn *hcon = conn->hcon; 5156 u16 mtu, mps, credits, result; 5157 struct l2cap_chan *chan, *tmp; 5158 int err = 0, sec_level; 5159 int i = 0; 5160 5161 if (cmd_len < sizeof(*rsp)) 5162 return -EPROTO; 5163 5164 mtu = __le16_to_cpu(rsp->mtu); 5165 mps = __le16_to_cpu(rsp->mps); 5166 credits = __le16_to_cpu(rsp->credits); 5167 result = __le16_to_cpu(rsp->result); 5168 5169 BT_DBG("mtu %u mps %u credits %u result 0x%4.4x", mtu, mps, credits, 5170 result); 5171 5172 mutex_lock(&conn->chan_lock); 5173 5174 cmd_len -= sizeof(*rsp); 5175 5176 list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) { 5177 u16 dcid; 5178 5179 if (chan->ident != cmd->ident || 5180 chan->mode != L2CAP_MODE_EXT_FLOWCTL || 5181 chan->state == BT_CONNECTED) 5182 continue; 5183 5184 l2cap_chan_lock(chan); 5185 5186 /* Check that there is a dcid for each pending channel */ 5187 if (cmd_len < sizeof(dcid)) { 5188 l2cap_chan_del(chan, ECONNREFUSED); 5189 l2cap_chan_unlock(chan); 5190 continue; 5191 } 5192 5193 dcid = __le16_to_cpu(rsp->dcid[i++]); 5194 cmd_len -= sizeof(u16); 5195 5196 BT_DBG("dcid[%d] 0x%4.4x", i, dcid); 5197 5198 /* Check if dcid is already in use */ 5199 if (dcid && __l2cap_get_chan_by_dcid(conn, dcid)) { 5200 /* If a device receives a 5201 * L2CAP_CREDIT_BASED_CONNECTION_RSP packet with an 5202 * already-assigned Destination CID, then both the 5203 * original channel and the new channel shall be 5204 * immediately discarded and not used. 5205 */ 5206 l2cap_chan_del(chan, ECONNREFUSED); 5207 l2cap_chan_unlock(chan); 5208 chan = __l2cap_get_chan_by_dcid(conn, dcid); 5209 l2cap_chan_lock(chan); 5210 l2cap_chan_del(chan, ECONNRESET); 5211 l2cap_chan_unlock(chan); 5212 continue; 5213 } 5214 5215 switch (result) { 5216 case L2CAP_CR_LE_AUTHENTICATION: 5217 case L2CAP_CR_LE_ENCRYPTION: 5218 /* If we already have MITM protection we can't do 5219 * anything. 5220 */ 5221 if (hcon->sec_level > BT_SECURITY_MEDIUM) { 5222 l2cap_chan_del(chan, ECONNREFUSED); 5223 break; 5224 } 5225 5226 sec_level = hcon->sec_level + 1; 5227 if (chan->sec_level < sec_level) 5228 chan->sec_level = sec_level; 5229 5230 /* We'll need to send a new Connect Request */ 5231 clear_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags); 5232 5233 smp_conn_security(hcon, chan->sec_level); 5234 break; 5235 5236 case L2CAP_CR_LE_BAD_PSM: 5237 l2cap_chan_del(chan, ECONNREFUSED); 5238 break; 5239 5240 default: 5241 /* If dcid was not set it means channels was refused */ 5242 if (!dcid) { 5243 l2cap_chan_del(chan, ECONNREFUSED); 5244 break; 5245 } 5246 5247 chan->ident = 0; 5248 chan->dcid = dcid; 5249 chan->omtu = mtu; 5250 chan->remote_mps = mps; 5251 chan->tx_credits = credits; 5252 l2cap_chan_ready(chan); 5253 break; 5254 } 5255 5256 l2cap_chan_unlock(chan); 5257 } 5258 5259 mutex_unlock(&conn->chan_lock); 5260 5261 return err; 5262 } 5263 l2cap_ecred_reconf_req(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)5264 static inline int l2cap_ecred_reconf_req(struct l2cap_conn *conn, 5265 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 5266 u8 *data) 5267 { 5268 struct l2cap_ecred_reconf_req *req = (void *) data; 5269 struct l2cap_ecred_reconf_rsp rsp; 5270 u16 mtu, mps, result; 5271 struct l2cap_chan *chan; 5272 int i, num_scid; 5273 5274 if (!enable_ecred) 5275 return -EINVAL; 5276 5277 if (cmd_len < sizeof(*req) || cmd_len - sizeof(*req) % sizeof(u16)) { 5278 result = L2CAP_CR_LE_INVALID_PARAMS; 5279 goto respond; 5280 } 5281 5282 mtu = __le16_to_cpu(req->mtu); 5283 mps = __le16_to_cpu(req->mps); 5284 5285 BT_DBG("mtu %u mps %u", mtu, mps); 5286 5287 if (mtu < L2CAP_ECRED_MIN_MTU) { 5288 result = L2CAP_RECONF_INVALID_MTU; 5289 goto respond; 5290 } 5291 5292 if (mps < L2CAP_ECRED_MIN_MPS) { 5293 result = L2CAP_RECONF_INVALID_MPS; 5294 goto respond; 5295 } 5296 5297 cmd_len -= sizeof(*req); 5298 num_scid = cmd_len / sizeof(u16); 5299 result = L2CAP_RECONF_SUCCESS; 5300 5301 for (i = 0; i < num_scid; i++) { 5302 u16 scid; 5303 5304 scid = __le16_to_cpu(req->scid[i]); 5305 if (!scid) 5306 return -EPROTO; 5307 5308 chan = __l2cap_get_chan_by_dcid(conn, scid); 5309 if (!chan) 5310 continue; 5311 5312 /* If the MTU value is decreased for any of the included 5313 * channels, then the receiver shall disconnect all 5314 * included channels. 5315 */ 5316 if (chan->omtu > mtu) { 5317 BT_ERR("chan %p decreased MTU %u -> %u", chan, 5318 chan->omtu, mtu); 5319 result = L2CAP_RECONF_INVALID_MTU; 5320 } 5321 5322 chan->omtu = mtu; 5323 chan->remote_mps = mps; 5324 } 5325 5326 respond: 5327 rsp.result = cpu_to_le16(result); 5328 5329 l2cap_send_cmd(conn, cmd->ident, L2CAP_ECRED_RECONF_RSP, sizeof(rsp), 5330 &rsp); 5331 5332 return 0; 5333 } 5334 l2cap_ecred_reconf_rsp(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)5335 static inline int l2cap_ecred_reconf_rsp(struct l2cap_conn *conn, 5336 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 5337 u8 *data) 5338 { 5339 struct l2cap_chan *chan, *tmp; 5340 struct l2cap_ecred_conn_rsp *rsp = (void *) data; 5341 u16 result; 5342 5343 if (cmd_len < sizeof(*rsp)) 5344 return -EPROTO; 5345 5346 result = __le16_to_cpu(rsp->result); 5347 5348 BT_DBG("result 0x%4.4x", rsp->result); 5349 5350 if (!result) 5351 return 0; 5352 5353 list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) { 5354 if (chan->ident != cmd->ident) 5355 continue; 5356 5357 l2cap_chan_del(chan, ECONNRESET); 5358 } 5359 5360 return 0; 5361 } 5362 l2cap_le_command_rej(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)5363 static inline int l2cap_le_command_rej(struct l2cap_conn *conn, 5364 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 5365 u8 *data) 5366 { 5367 struct l2cap_cmd_rej_unk *rej = (struct l2cap_cmd_rej_unk *) data; 5368 struct l2cap_chan *chan; 5369 5370 if (cmd_len < sizeof(*rej)) 5371 return -EPROTO; 5372 5373 mutex_lock(&conn->chan_lock); 5374 5375 chan = __l2cap_get_chan_by_ident(conn, cmd->ident); 5376 if (!chan) 5377 goto done; 5378 5379 chan = l2cap_chan_hold_unless_zero(chan); 5380 if (!chan) 5381 goto done; 5382 5383 l2cap_chan_lock(chan); 5384 l2cap_chan_del(chan, ECONNREFUSED); 5385 l2cap_chan_unlock(chan); 5386 l2cap_chan_put(chan); 5387 5388 done: 5389 mutex_unlock(&conn->chan_lock); 5390 return 0; 5391 } 5392 l2cap_le_sig_cmd(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)5393 static inline int l2cap_le_sig_cmd(struct l2cap_conn *conn, 5394 struct l2cap_cmd_hdr *cmd, u16 cmd_len, 5395 u8 *data) 5396 { 5397 int err = 0; 5398 5399 switch (cmd->code) { 5400 case L2CAP_COMMAND_REJ: 5401 l2cap_le_command_rej(conn, cmd, cmd_len, data); 5402 break; 5403 5404 case L2CAP_CONN_PARAM_UPDATE_REQ: 5405 err = l2cap_conn_param_update_req(conn, cmd, cmd_len, data); 5406 break; 5407 5408 case L2CAP_CONN_PARAM_UPDATE_RSP: 5409 break; 5410 5411 case L2CAP_LE_CONN_RSP: 5412 l2cap_le_connect_rsp(conn, cmd, cmd_len, data); 5413 break; 5414 5415 case L2CAP_LE_CONN_REQ: 5416 err = l2cap_le_connect_req(conn, cmd, cmd_len, data); 5417 break; 5418 5419 case L2CAP_LE_CREDITS: 5420 err = l2cap_le_credits(conn, cmd, cmd_len, data); 5421 break; 5422 5423 case L2CAP_ECRED_CONN_REQ: 5424 err = l2cap_ecred_conn_req(conn, cmd, cmd_len, data); 5425 break; 5426 5427 case L2CAP_ECRED_CONN_RSP: 5428 err = l2cap_ecred_conn_rsp(conn, cmd, cmd_len, data); 5429 break; 5430 5431 case L2CAP_ECRED_RECONF_REQ: 5432 err = l2cap_ecred_reconf_req(conn, cmd, cmd_len, data); 5433 break; 5434 5435 case L2CAP_ECRED_RECONF_RSP: 5436 err = l2cap_ecred_reconf_rsp(conn, cmd, cmd_len, data); 5437 break; 5438 5439 case L2CAP_DISCONN_REQ: 5440 err = l2cap_disconnect_req(conn, cmd, cmd_len, data); 5441 break; 5442 5443 case L2CAP_DISCONN_RSP: 5444 l2cap_disconnect_rsp(conn, cmd, cmd_len, data); 5445 break; 5446 5447 default: 5448 BT_ERR("Unknown LE signaling command 0x%2.2x", cmd->code); 5449 err = -EINVAL; 5450 break; 5451 } 5452 5453 return err; 5454 } 5455 l2cap_le_sig_channel(struct l2cap_conn * conn,struct sk_buff * skb)5456 static inline void l2cap_le_sig_channel(struct l2cap_conn *conn, 5457 struct sk_buff *skb) 5458 { 5459 struct hci_conn *hcon = conn->hcon; 5460 struct l2cap_cmd_hdr *cmd; 5461 u16 len; 5462 int err; 5463 5464 if (hcon->type != LE_LINK) 5465 goto drop; 5466 5467 if (skb->len < L2CAP_CMD_HDR_SIZE) 5468 goto drop; 5469 5470 cmd = (void *) skb->data; 5471 skb_pull(skb, L2CAP_CMD_HDR_SIZE); 5472 5473 len = le16_to_cpu(cmd->len); 5474 5475 BT_DBG("code 0x%2.2x len %d id 0x%2.2x", cmd->code, len, cmd->ident); 5476 5477 if (len != skb->len || !cmd->ident) { 5478 BT_DBG("corrupted command"); 5479 goto drop; 5480 } 5481 5482 err = l2cap_le_sig_cmd(conn, cmd, len, skb->data); 5483 if (err) { 5484 struct l2cap_cmd_rej_unk rej; 5485 5486 BT_ERR("Wrong link type (%d)", err); 5487 5488 rej.reason = cpu_to_le16(L2CAP_REJ_NOT_UNDERSTOOD); 5489 l2cap_send_cmd(conn, cmd->ident, L2CAP_COMMAND_REJ, 5490 sizeof(rej), &rej); 5491 } 5492 5493 drop: 5494 kfree_skb(skb); 5495 } 5496 l2cap_sig_send_rej(struct l2cap_conn * conn,u16 ident)5497 static inline void l2cap_sig_send_rej(struct l2cap_conn *conn, u16 ident) 5498 { 5499 struct l2cap_cmd_rej_unk rej; 5500 5501 rej.reason = cpu_to_le16(L2CAP_REJ_NOT_UNDERSTOOD); 5502 l2cap_send_cmd(conn, ident, L2CAP_COMMAND_REJ, sizeof(rej), &rej); 5503 } 5504 l2cap_sig_channel(struct l2cap_conn * conn,struct sk_buff * skb)5505 static inline void l2cap_sig_channel(struct l2cap_conn *conn, 5506 struct sk_buff *skb) 5507 { 5508 struct hci_conn *hcon = conn->hcon; 5509 struct l2cap_cmd_hdr *cmd; 5510 int err; 5511 5512 l2cap_raw_recv(conn, skb); 5513 5514 if (hcon->type != ACL_LINK) 5515 goto drop; 5516 5517 while (skb->len >= L2CAP_CMD_HDR_SIZE) { 5518 u16 len; 5519 5520 cmd = (void *) skb->data; 5521 skb_pull(skb, L2CAP_CMD_HDR_SIZE); 5522 5523 len = le16_to_cpu(cmd->len); 5524 5525 BT_DBG("code 0x%2.2x len %d id 0x%2.2x", cmd->code, len, 5526 cmd->ident); 5527 5528 if (len > skb->len || !cmd->ident) { 5529 BT_DBG("corrupted command"); 5530 l2cap_sig_send_rej(conn, cmd->ident); 5531 skb_pull(skb, len > skb->len ? skb->len : len); 5532 continue; 5533 } 5534 5535 err = l2cap_bredr_sig_cmd(conn, cmd, len, skb->data); 5536 if (err) { 5537 BT_ERR("Wrong link type (%d)", err); 5538 l2cap_sig_send_rej(conn, cmd->ident); 5539 } 5540 5541 skb_pull(skb, len); 5542 } 5543 5544 if (skb->len > 0) { 5545 BT_DBG("corrupted command"); 5546 l2cap_sig_send_rej(conn, 0); 5547 } 5548 5549 drop: 5550 kfree_skb(skb); 5551 } 5552 l2cap_check_fcs(struct l2cap_chan * chan,struct sk_buff * skb)5553 static int l2cap_check_fcs(struct l2cap_chan *chan, struct sk_buff *skb) 5554 { 5555 u16 our_fcs, rcv_fcs; 5556 int hdr_size; 5557 5558 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) 5559 hdr_size = L2CAP_EXT_HDR_SIZE; 5560 else 5561 hdr_size = L2CAP_ENH_HDR_SIZE; 5562 5563 if (chan->fcs == L2CAP_FCS_CRC16) { 5564 skb_trim(skb, skb->len - L2CAP_FCS_SIZE); 5565 rcv_fcs = get_unaligned_le16(skb->data + skb->len); 5566 our_fcs = crc16(0, skb->data - hdr_size, skb->len + hdr_size); 5567 5568 if (our_fcs != rcv_fcs) 5569 return -EBADMSG; 5570 } 5571 return 0; 5572 } 5573 l2cap_send_i_or_rr_or_rnr(struct l2cap_chan * chan)5574 static void l2cap_send_i_or_rr_or_rnr(struct l2cap_chan *chan) 5575 { 5576 struct l2cap_ctrl control; 5577 5578 BT_DBG("chan %p", chan); 5579 5580 memset(&control, 0, sizeof(control)); 5581 control.sframe = 1; 5582 control.final = 1; 5583 control.reqseq = chan->buffer_seq; 5584 set_bit(CONN_SEND_FBIT, &chan->conn_state); 5585 5586 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) { 5587 control.super = L2CAP_SUPER_RNR; 5588 l2cap_send_sframe(chan, &control); 5589 } 5590 5591 if (test_and_clear_bit(CONN_REMOTE_BUSY, &chan->conn_state) && 5592 chan->unacked_frames > 0) 5593 __set_retrans_timer(chan); 5594 5595 /* Send pending iframes */ 5596 l2cap_ertm_send(chan); 5597 5598 if (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state) && 5599 test_bit(CONN_SEND_FBIT, &chan->conn_state)) { 5600 /* F-bit wasn't sent in an s-frame or i-frame yet, so 5601 * send it now. 5602 */ 5603 control.super = L2CAP_SUPER_RR; 5604 l2cap_send_sframe(chan, &control); 5605 } 5606 } 5607 append_skb_frag(struct sk_buff * skb,struct sk_buff * new_frag,struct sk_buff ** last_frag)5608 static void append_skb_frag(struct sk_buff *skb, struct sk_buff *new_frag, 5609 struct sk_buff **last_frag) 5610 { 5611 /* skb->len reflects data in skb as well as all fragments 5612 * skb->data_len reflects only data in fragments 5613 */ 5614 if (!skb_has_frag_list(skb)) 5615 skb_shinfo(skb)->frag_list = new_frag; 5616 5617 new_frag->next = NULL; 5618 5619 (*last_frag)->next = new_frag; 5620 *last_frag = new_frag; 5621 5622 skb->len += new_frag->len; 5623 skb->data_len += new_frag->len; 5624 skb->truesize += new_frag->truesize; 5625 } 5626 l2cap_reassemble_sdu(struct l2cap_chan * chan,struct sk_buff * skb,struct l2cap_ctrl * control)5627 static int l2cap_reassemble_sdu(struct l2cap_chan *chan, struct sk_buff *skb, 5628 struct l2cap_ctrl *control) 5629 { 5630 int err = -EINVAL; 5631 5632 switch (control->sar) { 5633 case L2CAP_SAR_UNSEGMENTED: 5634 if (chan->sdu) 5635 break; 5636 5637 err = chan->ops->recv(chan, skb); 5638 break; 5639 5640 case L2CAP_SAR_START: 5641 if (chan->sdu) 5642 break; 5643 5644 if (!pskb_may_pull(skb, L2CAP_SDULEN_SIZE)) 5645 break; 5646 5647 chan->sdu_len = get_unaligned_le16(skb->data); 5648 skb_pull(skb, L2CAP_SDULEN_SIZE); 5649 5650 if (chan->sdu_len > chan->imtu) { 5651 err = -EMSGSIZE; 5652 break; 5653 } 5654 5655 if (skb->len >= chan->sdu_len) 5656 break; 5657 5658 chan->sdu = skb; 5659 chan->sdu_last_frag = skb; 5660 5661 skb = NULL; 5662 err = 0; 5663 break; 5664 5665 case L2CAP_SAR_CONTINUE: 5666 if (!chan->sdu) 5667 break; 5668 5669 append_skb_frag(chan->sdu, skb, 5670 &chan->sdu_last_frag); 5671 skb = NULL; 5672 5673 if (chan->sdu->len >= chan->sdu_len) 5674 break; 5675 5676 err = 0; 5677 break; 5678 5679 case L2CAP_SAR_END: 5680 if (!chan->sdu) 5681 break; 5682 5683 append_skb_frag(chan->sdu, skb, 5684 &chan->sdu_last_frag); 5685 skb = NULL; 5686 5687 if (chan->sdu->len != chan->sdu_len) 5688 break; 5689 5690 err = chan->ops->recv(chan, chan->sdu); 5691 5692 if (!err) { 5693 /* Reassembly complete */ 5694 chan->sdu = NULL; 5695 chan->sdu_last_frag = NULL; 5696 chan->sdu_len = 0; 5697 } 5698 break; 5699 } 5700 5701 if (err) { 5702 kfree_skb(skb); 5703 kfree_skb(chan->sdu); 5704 chan->sdu = NULL; 5705 chan->sdu_last_frag = NULL; 5706 chan->sdu_len = 0; 5707 } 5708 5709 return err; 5710 } 5711 l2cap_resegment(struct l2cap_chan * chan)5712 static int l2cap_resegment(struct l2cap_chan *chan) 5713 { 5714 /* Placeholder */ 5715 return 0; 5716 } 5717 l2cap_chan_busy(struct l2cap_chan * chan,int busy)5718 void l2cap_chan_busy(struct l2cap_chan *chan, int busy) 5719 { 5720 u8 event; 5721 5722 if (chan->mode != L2CAP_MODE_ERTM) 5723 return; 5724 5725 event = busy ? L2CAP_EV_LOCAL_BUSY_DETECTED : L2CAP_EV_LOCAL_BUSY_CLEAR; 5726 l2cap_tx(chan, NULL, NULL, event); 5727 } 5728 l2cap_rx_queued_iframes(struct l2cap_chan * chan)5729 static int l2cap_rx_queued_iframes(struct l2cap_chan *chan) 5730 { 5731 int err = 0; 5732 /* Pass sequential frames to l2cap_reassemble_sdu() 5733 * until a gap is encountered. 5734 */ 5735 5736 BT_DBG("chan %p", chan); 5737 5738 while (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) { 5739 struct sk_buff *skb; 5740 BT_DBG("Searching for skb with txseq %d (queue len %d)", 5741 chan->buffer_seq, skb_queue_len(&chan->srej_q)); 5742 5743 skb = l2cap_ertm_seq_in_queue(&chan->srej_q, chan->buffer_seq); 5744 5745 if (!skb) 5746 break; 5747 5748 skb_unlink(skb, &chan->srej_q); 5749 chan->buffer_seq = __next_seq(chan, chan->buffer_seq); 5750 err = l2cap_reassemble_sdu(chan, skb, &bt_cb(skb)->l2cap); 5751 if (err) 5752 break; 5753 } 5754 5755 if (skb_queue_empty(&chan->srej_q)) { 5756 chan->rx_state = L2CAP_RX_STATE_RECV; 5757 l2cap_send_ack(chan); 5758 } 5759 5760 return err; 5761 } 5762 l2cap_handle_srej(struct l2cap_chan * chan,struct l2cap_ctrl * control)5763 static void l2cap_handle_srej(struct l2cap_chan *chan, 5764 struct l2cap_ctrl *control) 5765 { 5766 struct sk_buff *skb; 5767 5768 BT_DBG("chan %p, control %p", chan, control); 5769 5770 if (control->reqseq == chan->next_tx_seq) { 5771 BT_DBG("Invalid reqseq %d, disconnecting", control->reqseq); 5772 l2cap_send_disconn_req(chan, ECONNRESET); 5773 return; 5774 } 5775 5776 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, control->reqseq); 5777 5778 if (skb == NULL) { 5779 BT_DBG("Seq %d not available for retransmission", 5780 control->reqseq); 5781 return; 5782 } 5783 5784 if (chan->max_tx != 0 && bt_cb(skb)->l2cap.retries >= chan->max_tx) { 5785 BT_DBG("Retry limit exceeded (%d)", chan->max_tx); 5786 l2cap_send_disconn_req(chan, ECONNRESET); 5787 return; 5788 } 5789 5790 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state); 5791 5792 if (control->poll) { 5793 l2cap_pass_to_tx(chan, control); 5794 5795 set_bit(CONN_SEND_FBIT, &chan->conn_state); 5796 l2cap_retransmit(chan, control); 5797 l2cap_ertm_send(chan); 5798 5799 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F) { 5800 set_bit(CONN_SREJ_ACT, &chan->conn_state); 5801 chan->srej_save_reqseq = control->reqseq; 5802 } 5803 } else { 5804 l2cap_pass_to_tx_fbit(chan, control); 5805 5806 if (control->final) { 5807 if (chan->srej_save_reqseq != control->reqseq || 5808 !test_and_clear_bit(CONN_SREJ_ACT, 5809 &chan->conn_state)) 5810 l2cap_retransmit(chan, control); 5811 } else { 5812 l2cap_retransmit(chan, control); 5813 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F) { 5814 set_bit(CONN_SREJ_ACT, &chan->conn_state); 5815 chan->srej_save_reqseq = control->reqseq; 5816 } 5817 } 5818 } 5819 } 5820 l2cap_handle_rej(struct l2cap_chan * chan,struct l2cap_ctrl * control)5821 static void l2cap_handle_rej(struct l2cap_chan *chan, 5822 struct l2cap_ctrl *control) 5823 { 5824 struct sk_buff *skb; 5825 5826 BT_DBG("chan %p, control %p", chan, control); 5827 5828 if (control->reqseq == chan->next_tx_seq) { 5829 BT_DBG("Invalid reqseq %d, disconnecting", control->reqseq); 5830 l2cap_send_disconn_req(chan, ECONNRESET); 5831 return; 5832 } 5833 5834 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, control->reqseq); 5835 5836 if (chan->max_tx && skb && 5837 bt_cb(skb)->l2cap.retries >= chan->max_tx) { 5838 BT_DBG("Retry limit exceeded (%d)", chan->max_tx); 5839 l2cap_send_disconn_req(chan, ECONNRESET); 5840 return; 5841 } 5842 5843 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state); 5844 5845 l2cap_pass_to_tx(chan, control); 5846 5847 if (control->final) { 5848 if (!test_and_clear_bit(CONN_REJ_ACT, &chan->conn_state)) 5849 l2cap_retransmit_all(chan, control); 5850 } else { 5851 l2cap_retransmit_all(chan, control); 5852 l2cap_ertm_send(chan); 5853 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F) 5854 set_bit(CONN_REJ_ACT, &chan->conn_state); 5855 } 5856 } 5857 l2cap_classify_txseq(struct l2cap_chan * chan,u16 txseq)5858 static u8 l2cap_classify_txseq(struct l2cap_chan *chan, u16 txseq) 5859 { 5860 BT_DBG("chan %p, txseq %d", chan, txseq); 5861 5862 BT_DBG("last_acked_seq %d, expected_tx_seq %d", chan->last_acked_seq, 5863 chan->expected_tx_seq); 5864 5865 if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) { 5866 if (__seq_offset(chan, txseq, chan->last_acked_seq) >= 5867 chan->tx_win) { 5868 /* See notes below regarding "double poll" and 5869 * invalid packets. 5870 */ 5871 if (chan->tx_win <= ((chan->tx_win_max + 1) >> 1)) { 5872 BT_DBG("Invalid/Ignore - after SREJ"); 5873 return L2CAP_TXSEQ_INVALID_IGNORE; 5874 } else { 5875 BT_DBG("Invalid - in window after SREJ sent"); 5876 return L2CAP_TXSEQ_INVALID; 5877 } 5878 } 5879 5880 if (chan->srej_list.head == txseq) { 5881 BT_DBG("Expected SREJ"); 5882 return L2CAP_TXSEQ_EXPECTED_SREJ; 5883 } 5884 5885 if (l2cap_ertm_seq_in_queue(&chan->srej_q, txseq)) { 5886 BT_DBG("Duplicate SREJ - txseq already stored"); 5887 return L2CAP_TXSEQ_DUPLICATE_SREJ; 5888 } 5889 5890 if (l2cap_seq_list_contains(&chan->srej_list, txseq)) { 5891 BT_DBG("Unexpected SREJ - not requested"); 5892 return L2CAP_TXSEQ_UNEXPECTED_SREJ; 5893 } 5894 } 5895 5896 if (chan->expected_tx_seq == txseq) { 5897 if (__seq_offset(chan, txseq, chan->last_acked_seq) >= 5898 chan->tx_win) { 5899 BT_DBG("Invalid - txseq outside tx window"); 5900 return L2CAP_TXSEQ_INVALID; 5901 } else { 5902 BT_DBG("Expected"); 5903 return L2CAP_TXSEQ_EXPECTED; 5904 } 5905 } 5906 5907 if (__seq_offset(chan, txseq, chan->last_acked_seq) < 5908 __seq_offset(chan, chan->expected_tx_seq, chan->last_acked_seq)) { 5909 BT_DBG("Duplicate - expected_tx_seq later than txseq"); 5910 return L2CAP_TXSEQ_DUPLICATE; 5911 } 5912 5913 if (__seq_offset(chan, txseq, chan->last_acked_seq) >= chan->tx_win) { 5914 /* A source of invalid packets is a "double poll" condition, 5915 * where delays cause us to send multiple poll packets. If 5916 * the remote stack receives and processes both polls, 5917 * sequence numbers can wrap around in such a way that a 5918 * resent frame has a sequence number that looks like new data 5919 * with a sequence gap. This would trigger an erroneous SREJ 5920 * request. 5921 * 5922 * Fortunately, this is impossible with a tx window that's 5923 * less than half of the maximum sequence number, which allows 5924 * invalid frames to be safely ignored. 5925 * 5926 * With tx window sizes greater than half of the tx window 5927 * maximum, the frame is invalid and cannot be ignored. This 5928 * causes a disconnect. 5929 */ 5930 5931 if (chan->tx_win <= ((chan->tx_win_max + 1) >> 1)) { 5932 BT_DBG("Invalid/Ignore - txseq outside tx window"); 5933 return L2CAP_TXSEQ_INVALID_IGNORE; 5934 } else { 5935 BT_DBG("Invalid - txseq outside tx window"); 5936 return L2CAP_TXSEQ_INVALID; 5937 } 5938 } else { 5939 BT_DBG("Unexpected - txseq indicates missing frames"); 5940 return L2CAP_TXSEQ_UNEXPECTED; 5941 } 5942 } 5943 l2cap_rx_state_recv(struct l2cap_chan * chan,struct l2cap_ctrl * control,struct sk_buff * skb,u8 event)5944 static int l2cap_rx_state_recv(struct l2cap_chan *chan, 5945 struct l2cap_ctrl *control, 5946 struct sk_buff *skb, u8 event) 5947 { 5948 struct l2cap_ctrl local_control; 5949 int err = 0; 5950 bool skb_in_use = false; 5951 5952 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb, 5953 event); 5954 5955 switch (event) { 5956 case L2CAP_EV_RECV_IFRAME: 5957 switch (l2cap_classify_txseq(chan, control->txseq)) { 5958 case L2CAP_TXSEQ_EXPECTED: 5959 l2cap_pass_to_tx(chan, control); 5960 5961 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) { 5962 BT_DBG("Busy, discarding expected seq %d", 5963 control->txseq); 5964 break; 5965 } 5966 5967 chan->expected_tx_seq = __next_seq(chan, 5968 control->txseq); 5969 5970 chan->buffer_seq = chan->expected_tx_seq; 5971 skb_in_use = true; 5972 5973 /* l2cap_reassemble_sdu may free skb, hence invalidate 5974 * control, so make a copy in advance to use it after 5975 * l2cap_reassemble_sdu returns and to avoid the race 5976 * condition, for example: 5977 * 5978 * The current thread calls: 5979 * l2cap_reassemble_sdu 5980 * chan->ops->recv == l2cap_sock_recv_cb 5981 * __sock_queue_rcv_skb 5982 * Another thread calls: 5983 * bt_sock_recvmsg 5984 * skb_recv_datagram 5985 * skb_free_datagram 5986 * Then the current thread tries to access control, but 5987 * it was freed by skb_free_datagram. 5988 */ 5989 local_control = *control; 5990 err = l2cap_reassemble_sdu(chan, skb, control); 5991 if (err) 5992 break; 5993 5994 if (local_control.final) { 5995 if (!test_and_clear_bit(CONN_REJ_ACT, 5996 &chan->conn_state)) { 5997 local_control.final = 0; 5998 l2cap_retransmit_all(chan, &local_control); 5999 l2cap_ertm_send(chan); 6000 } 6001 } 6002 6003 if (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) 6004 l2cap_send_ack(chan); 6005 break; 6006 case L2CAP_TXSEQ_UNEXPECTED: 6007 l2cap_pass_to_tx(chan, control); 6008 6009 /* Can't issue SREJ frames in the local busy state. 6010 * Drop this frame, it will be seen as missing 6011 * when local busy is exited. 6012 */ 6013 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) { 6014 BT_DBG("Busy, discarding unexpected seq %d", 6015 control->txseq); 6016 break; 6017 } 6018 6019 /* There was a gap in the sequence, so an SREJ 6020 * must be sent for each missing frame. The 6021 * current frame is stored for later use. 6022 */ 6023 skb_queue_tail(&chan->srej_q, skb); 6024 skb_in_use = true; 6025 BT_DBG("Queued %p (queue len %d)", skb, 6026 skb_queue_len(&chan->srej_q)); 6027 6028 clear_bit(CONN_SREJ_ACT, &chan->conn_state); 6029 l2cap_seq_list_clear(&chan->srej_list); 6030 l2cap_send_srej(chan, control->txseq); 6031 6032 chan->rx_state = L2CAP_RX_STATE_SREJ_SENT; 6033 break; 6034 case L2CAP_TXSEQ_DUPLICATE: 6035 l2cap_pass_to_tx(chan, control); 6036 break; 6037 case L2CAP_TXSEQ_INVALID_IGNORE: 6038 break; 6039 case L2CAP_TXSEQ_INVALID: 6040 default: 6041 l2cap_send_disconn_req(chan, ECONNRESET); 6042 break; 6043 } 6044 break; 6045 case L2CAP_EV_RECV_RR: 6046 l2cap_pass_to_tx(chan, control); 6047 if (control->final) { 6048 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state); 6049 6050 if (!test_and_clear_bit(CONN_REJ_ACT, 6051 &chan->conn_state)) { 6052 control->final = 0; 6053 l2cap_retransmit_all(chan, control); 6054 } 6055 6056 l2cap_ertm_send(chan); 6057 } else if (control->poll) { 6058 l2cap_send_i_or_rr_or_rnr(chan); 6059 } else { 6060 if (test_and_clear_bit(CONN_REMOTE_BUSY, 6061 &chan->conn_state) && 6062 chan->unacked_frames) 6063 __set_retrans_timer(chan); 6064 6065 l2cap_ertm_send(chan); 6066 } 6067 break; 6068 case L2CAP_EV_RECV_RNR: 6069 set_bit(CONN_REMOTE_BUSY, &chan->conn_state); 6070 l2cap_pass_to_tx(chan, control); 6071 if (control && control->poll) { 6072 set_bit(CONN_SEND_FBIT, &chan->conn_state); 6073 l2cap_send_rr_or_rnr(chan, 0); 6074 } 6075 __clear_retrans_timer(chan); 6076 l2cap_seq_list_clear(&chan->retrans_list); 6077 break; 6078 case L2CAP_EV_RECV_REJ: 6079 l2cap_handle_rej(chan, control); 6080 break; 6081 case L2CAP_EV_RECV_SREJ: 6082 l2cap_handle_srej(chan, control); 6083 break; 6084 default: 6085 break; 6086 } 6087 6088 if (skb && !skb_in_use) { 6089 BT_DBG("Freeing %p", skb); 6090 kfree_skb(skb); 6091 } 6092 6093 return err; 6094 } 6095 l2cap_rx_state_srej_sent(struct l2cap_chan * chan,struct l2cap_ctrl * control,struct sk_buff * skb,u8 event)6096 static int l2cap_rx_state_srej_sent(struct l2cap_chan *chan, 6097 struct l2cap_ctrl *control, 6098 struct sk_buff *skb, u8 event) 6099 { 6100 int err = 0; 6101 u16 txseq = control->txseq; 6102 bool skb_in_use = false; 6103 6104 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb, 6105 event); 6106 6107 switch (event) { 6108 case L2CAP_EV_RECV_IFRAME: 6109 switch (l2cap_classify_txseq(chan, txseq)) { 6110 case L2CAP_TXSEQ_EXPECTED: 6111 /* Keep frame for reassembly later */ 6112 l2cap_pass_to_tx(chan, control); 6113 skb_queue_tail(&chan->srej_q, skb); 6114 skb_in_use = true; 6115 BT_DBG("Queued %p (queue len %d)", skb, 6116 skb_queue_len(&chan->srej_q)); 6117 6118 chan->expected_tx_seq = __next_seq(chan, txseq); 6119 break; 6120 case L2CAP_TXSEQ_EXPECTED_SREJ: 6121 l2cap_seq_list_pop(&chan->srej_list); 6122 6123 l2cap_pass_to_tx(chan, control); 6124 skb_queue_tail(&chan->srej_q, skb); 6125 skb_in_use = true; 6126 BT_DBG("Queued %p (queue len %d)", skb, 6127 skb_queue_len(&chan->srej_q)); 6128 6129 err = l2cap_rx_queued_iframes(chan); 6130 if (err) 6131 break; 6132 6133 break; 6134 case L2CAP_TXSEQ_UNEXPECTED: 6135 /* Got a frame that can't be reassembled yet. 6136 * Save it for later, and send SREJs to cover 6137 * the missing frames. 6138 */ 6139 skb_queue_tail(&chan->srej_q, skb); 6140 skb_in_use = true; 6141 BT_DBG("Queued %p (queue len %d)", skb, 6142 skb_queue_len(&chan->srej_q)); 6143 6144 l2cap_pass_to_tx(chan, control); 6145 l2cap_send_srej(chan, control->txseq); 6146 break; 6147 case L2CAP_TXSEQ_UNEXPECTED_SREJ: 6148 /* This frame was requested with an SREJ, but 6149 * some expected retransmitted frames are 6150 * missing. Request retransmission of missing 6151 * SREJ'd frames. 6152 */ 6153 skb_queue_tail(&chan->srej_q, skb); 6154 skb_in_use = true; 6155 BT_DBG("Queued %p (queue len %d)", skb, 6156 skb_queue_len(&chan->srej_q)); 6157 6158 l2cap_pass_to_tx(chan, control); 6159 l2cap_send_srej_list(chan, control->txseq); 6160 break; 6161 case L2CAP_TXSEQ_DUPLICATE_SREJ: 6162 /* We've already queued this frame. Drop this copy. */ 6163 l2cap_pass_to_tx(chan, control); 6164 break; 6165 case L2CAP_TXSEQ_DUPLICATE: 6166 /* Expecting a later sequence number, so this frame 6167 * was already received. Ignore it completely. 6168 */ 6169 break; 6170 case L2CAP_TXSEQ_INVALID_IGNORE: 6171 break; 6172 case L2CAP_TXSEQ_INVALID: 6173 default: 6174 l2cap_send_disconn_req(chan, ECONNRESET); 6175 break; 6176 } 6177 break; 6178 case L2CAP_EV_RECV_RR: 6179 l2cap_pass_to_tx(chan, control); 6180 if (control->final) { 6181 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state); 6182 6183 if (!test_and_clear_bit(CONN_REJ_ACT, 6184 &chan->conn_state)) { 6185 control->final = 0; 6186 l2cap_retransmit_all(chan, control); 6187 } 6188 6189 l2cap_ertm_send(chan); 6190 } else if (control->poll) { 6191 if (test_and_clear_bit(CONN_REMOTE_BUSY, 6192 &chan->conn_state) && 6193 chan->unacked_frames) { 6194 __set_retrans_timer(chan); 6195 } 6196 6197 set_bit(CONN_SEND_FBIT, &chan->conn_state); 6198 l2cap_send_srej_tail(chan); 6199 } else { 6200 if (test_and_clear_bit(CONN_REMOTE_BUSY, 6201 &chan->conn_state) && 6202 chan->unacked_frames) 6203 __set_retrans_timer(chan); 6204 6205 l2cap_send_ack(chan); 6206 } 6207 break; 6208 case L2CAP_EV_RECV_RNR: 6209 set_bit(CONN_REMOTE_BUSY, &chan->conn_state); 6210 l2cap_pass_to_tx(chan, control); 6211 if (control->poll) { 6212 l2cap_send_srej_tail(chan); 6213 } else { 6214 struct l2cap_ctrl rr_control; 6215 memset(&rr_control, 0, sizeof(rr_control)); 6216 rr_control.sframe = 1; 6217 rr_control.super = L2CAP_SUPER_RR; 6218 rr_control.reqseq = chan->buffer_seq; 6219 l2cap_send_sframe(chan, &rr_control); 6220 } 6221 6222 break; 6223 case L2CAP_EV_RECV_REJ: 6224 l2cap_handle_rej(chan, control); 6225 break; 6226 case L2CAP_EV_RECV_SREJ: 6227 l2cap_handle_srej(chan, control); 6228 break; 6229 } 6230 6231 if (skb && !skb_in_use) { 6232 BT_DBG("Freeing %p", skb); 6233 kfree_skb(skb); 6234 } 6235 6236 return err; 6237 } 6238 l2cap_finish_move(struct l2cap_chan * chan)6239 static int l2cap_finish_move(struct l2cap_chan *chan) 6240 { 6241 BT_DBG("chan %p", chan); 6242 6243 chan->rx_state = L2CAP_RX_STATE_RECV; 6244 chan->conn->mtu = chan->conn->hcon->mtu; 6245 6246 return l2cap_resegment(chan); 6247 } 6248 l2cap_rx_state_wait_p(struct l2cap_chan * chan,struct l2cap_ctrl * control,struct sk_buff * skb,u8 event)6249 static int l2cap_rx_state_wait_p(struct l2cap_chan *chan, 6250 struct l2cap_ctrl *control, 6251 struct sk_buff *skb, u8 event) 6252 { 6253 int err; 6254 6255 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb, 6256 event); 6257 6258 if (!control->poll) 6259 return -EPROTO; 6260 6261 l2cap_process_reqseq(chan, control->reqseq); 6262 6263 if (!skb_queue_empty(&chan->tx_q)) 6264 chan->tx_send_head = skb_peek(&chan->tx_q); 6265 else 6266 chan->tx_send_head = NULL; 6267 6268 /* Rewind next_tx_seq to the point expected 6269 * by the receiver. 6270 */ 6271 chan->next_tx_seq = control->reqseq; 6272 chan->unacked_frames = 0; 6273 6274 err = l2cap_finish_move(chan); 6275 if (err) 6276 return err; 6277 6278 set_bit(CONN_SEND_FBIT, &chan->conn_state); 6279 l2cap_send_i_or_rr_or_rnr(chan); 6280 6281 if (event == L2CAP_EV_RECV_IFRAME) 6282 return -EPROTO; 6283 6284 return l2cap_rx_state_recv(chan, control, NULL, event); 6285 } 6286 l2cap_rx_state_wait_f(struct l2cap_chan * chan,struct l2cap_ctrl * control,struct sk_buff * skb,u8 event)6287 static int l2cap_rx_state_wait_f(struct l2cap_chan *chan, 6288 struct l2cap_ctrl *control, 6289 struct sk_buff *skb, u8 event) 6290 { 6291 int err; 6292 6293 if (!control->final) 6294 return -EPROTO; 6295 6296 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state); 6297 6298 chan->rx_state = L2CAP_RX_STATE_RECV; 6299 l2cap_process_reqseq(chan, control->reqseq); 6300 6301 if (!skb_queue_empty(&chan->tx_q)) 6302 chan->tx_send_head = skb_peek(&chan->tx_q); 6303 else 6304 chan->tx_send_head = NULL; 6305 6306 /* Rewind next_tx_seq to the point expected 6307 * by the receiver. 6308 */ 6309 chan->next_tx_seq = control->reqseq; 6310 chan->unacked_frames = 0; 6311 chan->conn->mtu = chan->conn->hcon->mtu; 6312 6313 err = l2cap_resegment(chan); 6314 6315 if (!err) 6316 err = l2cap_rx_state_recv(chan, control, skb, event); 6317 6318 return err; 6319 } 6320 __valid_reqseq(struct l2cap_chan * chan,u16 reqseq)6321 static bool __valid_reqseq(struct l2cap_chan *chan, u16 reqseq) 6322 { 6323 /* Make sure reqseq is for a packet that has been sent but not acked */ 6324 u16 unacked; 6325 6326 unacked = __seq_offset(chan, chan->next_tx_seq, chan->expected_ack_seq); 6327 return __seq_offset(chan, chan->next_tx_seq, reqseq) <= unacked; 6328 } 6329 l2cap_rx(struct l2cap_chan * chan,struct l2cap_ctrl * control,struct sk_buff * skb,u8 event)6330 static int l2cap_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control, 6331 struct sk_buff *skb, u8 event) 6332 { 6333 int err = 0; 6334 6335 BT_DBG("chan %p, control %p, skb %p, event %d, state %d", chan, 6336 control, skb, event, chan->rx_state); 6337 6338 if (__valid_reqseq(chan, control->reqseq)) { 6339 switch (chan->rx_state) { 6340 case L2CAP_RX_STATE_RECV: 6341 err = l2cap_rx_state_recv(chan, control, skb, event); 6342 break; 6343 case L2CAP_RX_STATE_SREJ_SENT: 6344 err = l2cap_rx_state_srej_sent(chan, control, skb, 6345 event); 6346 break; 6347 case L2CAP_RX_STATE_WAIT_P: 6348 err = l2cap_rx_state_wait_p(chan, control, skb, event); 6349 break; 6350 case L2CAP_RX_STATE_WAIT_F: 6351 err = l2cap_rx_state_wait_f(chan, control, skb, event); 6352 break; 6353 default: 6354 /* shut it down */ 6355 break; 6356 } 6357 } else { 6358 BT_DBG("Invalid reqseq %d (next_tx_seq %d, expected_ack_seq %d", 6359 control->reqseq, chan->next_tx_seq, 6360 chan->expected_ack_seq); 6361 l2cap_send_disconn_req(chan, ECONNRESET); 6362 } 6363 6364 return err; 6365 } 6366 l2cap_stream_rx(struct l2cap_chan * chan,struct l2cap_ctrl * control,struct sk_buff * skb)6367 static int l2cap_stream_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control, 6368 struct sk_buff *skb) 6369 { 6370 /* l2cap_reassemble_sdu may free skb, hence invalidate control, so store 6371 * the txseq field in advance to use it after l2cap_reassemble_sdu 6372 * returns and to avoid the race condition, for example: 6373 * 6374 * The current thread calls: 6375 * l2cap_reassemble_sdu 6376 * chan->ops->recv == l2cap_sock_recv_cb 6377 * __sock_queue_rcv_skb 6378 * Another thread calls: 6379 * bt_sock_recvmsg 6380 * skb_recv_datagram 6381 * skb_free_datagram 6382 * Then the current thread tries to access control, but it was freed by 6383 * skb_free_datagram. 6384 */ 6385 u16 txseq = control->txseq; 6386 6387 BT_DBG("chan %p, control %p, skb %p, state %d", chan, control, skb, 6388 chan->rx_state); 6389 6390 if (l2cap_classify_txseq(chan, txseq) == L2CAP_TXSEQ_EXPECTED) { 6391 l2cap_pass_to_tx(chan, control); 6392 6393 BT_DBG("buffer_seq %u->%u", chan->buffer_seq, 6394 __next_seq(chan, chan->buffer_seq)); 6395 6396 chan->buffer_seq = __next_seq(chan, chan->buffer_seq); 6397 6398 l2cap_reassemble_sdu(chan, skb, control); 6399 } else { 6400 if (chan->sdu) { 6401 kfree_skb(chan->sdu); 6402 chan->sdu = NULL; 6403 } 6404 chan->sdu_last_frag = NULL; 6405 chan->sdu_len = 0; 6406 6407 if (skb) { 6408 BT_DBG("Freeing %p", skb); 6409 kfree_skb(skb); 6410 } 6411 } 6412 6413 chan->last_acked_seq = txseq; 6414 chan->expected_tx_seq = __next_seq(chan, txseq); 6415 6416 return 0; 6417 } 6418 l2cap_data_rcv(struct l2cap_chan * chan,struct sk_buff * skb)6419 static int l2cap_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb) 6420 { 6421 struct l2cap_ctrl *control = &bt_cb(skb)->l2cap; 6422 u16 len; 6423 u8 event; 6424 6425 __unpack_control(chan, skb); 6426 6427 len = skb->len; 6428 6429 /* 6430 * We can just drop the corrupted I-frame here. 6431 * Receiver will miss it and start proper recovery 6432 * procedures and ask for retransmission. 6433 */ 6434 if (l2cap_check_fcs(chan, skb)) 6435 goto drop; 6436 6437 if (!control->sframe && control->sar == L2CAP_SAR_START) 6438 len -= L2CAP_SDULEN_SIZE; 6439 6440 if (chan->fcs == L2CAP_FCS_CRC16) 6441 len -= L2CAP_FCS_SIZE; 6442 6443 if (len > chan->mps) { 6444 l2cap_send_disconn_req(chan, ECONNRESET); 6445 goto drop; 6446 } 6447 6448 if (chan->ops->filter) { 6449 if (chan->ops->filter(chan, skb)) 6450 goto drop; 6451 } 6452 6453 if (!control->sframe) { 6454 int err; 6455 6456 BT_DBG("iframe sar %d, reqseq %d, final %d, txseq %d", 6457 control->sar, control->reqseq, control->final, 6458 control->txseq); 6459 6460 /* Validate F-bit - F=0 always valid, F=1 only 6461 * valid in TX WAIT_F 6462 */ 6463 if (control->final && chan->tx_state != L2CAP_TX_STATE_WAIT_F) 6464 goto drop; 6465 6466 if (chan->mode != L2CAP_MODE_STREAMING) { 6467 event = L2CAP_EV_RECV_IFRAME; 6468 err = l2cap_rx(chan, control, skb, event); 6469 } else { 6470 err = l2cap_stream_rx(chan, control, skb); 6471 } 6472 6473 if (err) 6474 l2cap_send_disconn_req(chan, ECONNRESET); 6475 } else { 6476 const u8 rx_func_to_event[4] = { 6477 L2CAP_EV_RECV_RR, L2CAP_EV_RECV_REJ, 6478 L2CAP_EV_RECV_RNR, L2CAP_EV_RECV_SREJ 6479 }; 6480 6481 /* Only I-frames are expected in streaming mode */ 6482 if (chan->mode == L2CAP_MODE_STREAMING) 6483 goto drop; 6484 6485 BT_DBG("sframe reqseq %d, final %d, poll %d, super %d", 6486 control->reqseq, control->final, control->poll, 6487 control->super); 6488 6489 if (len != 0) { 6490 BT_ERR("Trailing bytes: %d in sframe", len); 6491 l2cap_send_disconn_req(chan, ECONNRESET); 6492 goto drop; 6493 } 6494 6495 /* Validate F and P bits */ 6496 if (control->final && (control->poll || 6497 chan->tx_state != L2CAP_TX_STATE_WAIT_F)) 6498 goto drop; 6499 6500 event = rx_func_to_event[control->super]; 6501 if (l2cap_rx(chan, control, skb, event)) 6502 l2cap_send_disconn_req(chan, ECONNRESET); 6503 } 6504 6505 return 0; 6506 6507 drop: 6508 kfree_skb(skb); 6509 return 0; 6510 } 6511 l2cap_chan_le_send_credits(struct l2cap_chan * chan)6512 static void l2cap_chan_le_send_credits(struct l2cap_chan *chan) 6513 { 6514 struct l2cap_conn *conn = chan->conn; 6515 struct l2cap_le_credits pkt; 6516 u16 return_credits = l2cap_le_rx_credits(chan); 6517 6518 if (chan->rx_credits >= return_credits) 6519 return; 6520 6521 return_credits -= chan->rx_credits; 6522 6523 BT_DBG("chan %p returning %u credits to sender", chan, return_credits); 6524 6525 chan->rx_credits += return_credits; 6526 6527 pkt.cid = cpu_to_le16(chan->scid); 6528 pkt.credits = cpu_to_le16(return_credits); 6529 6530 chan->ident = l2cap_get_ident(conn); 6531 6532 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CREDITS, sizeof(pkt), &pkt); 6533 } 6534 l2cap_chan_rx_avail(struct l2cap_chan * chan,ssize_t rx_avail)6535 void l2cap_chan_rx_avail(struct l2cap_chan *chan, ssize_t rx_avail) 6536 { 6537 if (chan->rx_avail == rx_avail) 6538 return; 6539 6540 BT_DBG("chan %p has %zd bytes avail for rx", chan, rx_avail); 6541 6542 chan->rx_avail = rx_avail; 6543 6544 if (chan->state == BT_CONNECTED) 6545 l2cap_chan_le_send_credits(chan); 6546 } 6547 l2cap_ecred_recv(struct l2cap_chan * chan,struct sk_buff * skb)6548 static int l2cap_ecred_recv(struct l2cap_chan *chan, struct sk_buff *skb) 6549 { 6550 int err; 6551 6552 BT_DBG("SDU reassemble complete: chan %p skb->len %u", chan, skb->len); 6553 6554 /* Wait recv to confirm reception before updating the credits */ 6555 err = chan->ops->recv(chan, skb); 6556 6557 if (err < 0 && chan->rx_avail != -1) { 6558 BT_ERR("Queueing received LE L2CAP data failed"); 6559 l2cap_send_disconn_req(chan, ECONNRESET); 6560 return err; 6561 } 6562 6563 /* Update credits whenever an SDU is received */ 6564 l2cap_chan_le_send_credits(chan); 6565 6566 return err; 6567 } 6568 l2cap_ecred_data_rcv(struct l2cap_chan * chan,struct sk_buff * skb)6569 static int l2cap_ecred_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb) 6570 { 6571 int err; 6572 6573 if (!chan->rx_credits) { 6574 BT_ERR("No credits to receive LE L2CAP data"); 6575 l2cap_send_disconn_req(chan, ECONNRESET); 6576 return -ENOBUFS; 6577 } 6578 6579 if (chan->imtu < skb->len) { 6580 BT_ERR("Too big LE L2CAP PDU"); 6581 return -ENOBUFS; 6582 } 6583 6584 chan->rx_credits--; 6585 BT_DBG("chan %p: rx_credits %u -> %u", 6586 chan, chan->rx_credits + 1, chan->rx_credits); 6587 6588 /* Update if remote had run out of credits, this should only happens 6589 * if the remote is not using the entire MPS. 6590 */ 6591 if (!chan->rx_credits) 6592 l2cap_chan_le_send_credits(chan); 6593 6594 err = 0; 6595 6596 if (!chan->sdu) { 6597 u16 sdu_len; 6598 6599 sdu_len = get_unaligned_le16(skb->data); 6600 skb_pull(skb, L2CAP_SDULEN_SIZE); 6601 6602 BT_DBG("Start of new SDU. sdu_len %u skb->len %u imtu %u", 6603 sdu_len, skb->len, chan->imtu); 6604 6605 if (sdu_len > chan->imtu) { 6606 BT_ERR("Too big LE L2CAP SDU length received"); 6607 err = -EMSGSIZE; 6608 goto failed; 6609 } 6610 6611 if (skb->len > sdu_len) { 6612 BT_ERR("Too much LE L2CAP data received"); 6613 err = -EINVAL; 6614 goto failed; 6615 } 6616 6617 if (skb->len == sdu_len) 6618 return l2cap_ecred_recv(chan, skb); 6619 6620 chan->sdu = skb; 6621 chan->sdu_len = sdu_len; 6622 chan->sdu_last_frag = skb; 6623 6624 /* Detect if remote is not able to use the selected MPS */ 6625 if (skb->len + L2CAP_SDULEN_SIZE < chan->mps) { 6626 u16 mps_len = skb->len + L2CAP_SDULEN_SIZE; 6627 6628 /* Adjust the number of credits */ 6629 BT_DBG("chan->mps %u -> %u", chan->mps, mps_len); 6630 chan->mps = mps_len; 6631 l2cap_chan_le_send_credits(chan); 6632 } 6633 6634 return 0; 6635 } 6636 6637 BT_DBG("SDU fragment. chan->sdu->len %u skb->len %u chan->sdu_len %u", 6638 chan->sdu->len, skb->len, chan->sdu_len); 6639 6640 if (chan->sdu->len + skb->len > chan->sdu_len) { 6641 BT_ERR("Too much LE L2CAP data received"); 6642 err = -EINVAL; 6643 goto failed; 6644 } 6645 6646 append_skb_frag(chan->sdu, skb, &chan->sdu_last_frag); 6647 skb = NULL; 6648 6649 if (chan->sdu->len == chan->sdu_len) { 6650 err = l2cap_ecred_recv(chan, chan->sdu); 6651 if (!err) { 6652 chan->sdu = NULL; 6653 chan->sdu_last_frag = NULL; 6654 chan->sdu_len = 0; 6655 } 6656 } 6657 6658 failed: 6659 if (err) { 6660 kfree_skb(skb); 6661 kfree_skb(chan->sdu); 6662 chan->sdu = NULL; 6663 chan->sdu_last_frag = NULL; 6664 chan->sdu_len = 0; 6665 } 6666 6667 /* We can't return an error here since we took care of the skb 6668 * freeing internally. An error return would cause the caller to 6669 * do a double-free of the skb. 6670 */ 6671 return 0; 6672 } 6673 l2cap_data_channel(struct l2cap_conn * conn,u16 cid,struct sk_buff * skb)6674 static void l2cap_data_channel(struct l2cap_conn *conn, u16 cid, 6675 struct sk_buff *skb) 6676 { 6677 struct l2cap_chan *chan; 6678 6679 chan = l2cap_get_chan_by_scid(conn, cid); 6680 if (!chan) { 6681 BT_DBG("unknown cid 0x%4.4x", cid); 6682 /* Drop packet and return */ 6683 kfree_skb(skb); 6684 return; 6685 } 6686 6687 BT_DBG("chan %p, len %d", chan, skb->len); 6688 6689 /* If we receive data on a fixed channel before the info req/rsp 6690 * procedure is done simply assume that the channel is supported 6691 * and mark it as ready. 6692 */ 6693 if (chan->chan_type == L2CAP_CHAN_FIXED) 6694 l2cap_chan_ready(chan); 6695 6696 if (chan->state != BT_CONNECTED) 6697 goto drop; 6698 6699 switch (chan->mode) { 6700 case L2CAP_MODE_LE_FLOWCTL: 6701 case L2CAP_MODE_EXT_FLOWCTL: 6702 if (l2cap_ecred_data_rcv(chan, skb) < 0) 6703 goto drop; 6704 6705 goto done; 6706 6707 case L2CAP_MODE_BASIC: 6708 /* If socket recv buffers overflows we drop data here 6709 * which is *bad* because L2CAP has to be reliable. 6710 * But we don't have any other choice. L2CAP doesn't 6711 * provide flow control mechanism. */ 6712 6713 if (chan->imtu < skb->len) { 6714 BT_ERR("Dropping L2CAP data: receive buffer overflow"); 6715 goto drop; 6716 } 6717 6718 if (!chan->ops->recv(chan, skb)) 6719 goto done; 6720 break; 6721 6722 case L2CAP_MODE_ERTM: 6723 case L2CAP_MODE_STREAMING: 6724 l2cap_data_rcv(chan, skb); 6725 goto done; 6726 6727 default: 6728 BT_DBG("chan %p: bad mode 0x%2.2x", chan, chan->mode); 6729 break; 6730 } 6731 6732 drop: 6733 kfree_skb(skb); 6734 6735 done: 6736 l2cap_chan_unlock(chan); 6737 l2cap_chan_put(chan); 6738 } 6739 l2cap_conless_channel(struct l2cap_conn * conn,__le16 psm,struct sk_buff * skb)6740 static void l2cap_conless_channel(struct l2cap_conn *conn, __le16 psm, 6741 struct sk_buff *skb) 6742 { 6743 struct hci_conn *hcon = conn->hcon; 6744 struct l2cap_chan *chan; 6745 6746 if (hcon->type != ACL_LINK) 6747 goto free_skb; 6748 6749 chan = l2cap_global_chan_by_psm(0, psm, &hcon->src, &hcon->dst, 6750 ACL_LINK); 6751 if (!chan) 6752 goto free_skb; 6753 6754 BT_DBG("chan %p, len %d", chan, skb->len); 6755 6756 l2cap_chan_lock(chan); 6757 6758 if (chan->state != BT_BOUND && chan->state != BT_CONNECTED) 6759 goto drop; 6760 6761 if (chan->imtu < skb->len) 6762 goto drop; 6763 6764 /* Store remote BD_ADDR and PSM for msg_name */ 6765 bacpy(&bt_cb(skb)->l2cap.bdaddr, &hcon->dst); 6766 bt_cb(skb)->l2cap.psm = psm; 6767 6768 if (!chan->ops->recv(chan, skb)) { 6769 l2cap_chan_unlock(chan); 6770 l2cap_chan_put(chan); 6771 return; 6772 } 6773 6774 drop: 6775 l2cap_chan_unlock(chan); 6776 l2cap_chan_put(chan); 6777 free_skb: 6778 kfree_skb(skb); 6779 } 6780 l2cap_recv_frame(struct l2cap_conn * conn,struct sk_buff * skb)6781 static void l2cap_recv_frame(struct l2cap_conn *conn, struct sk_buff *skb) 6782 { 6783 struct l2cap_hdr *lh = (void *) skb->data; 6784 struct hci_conn *hcon = conn->hcon; 6785 u16 cid, len; 6786 __le16 psm; 6787 6788 if (hcon->state != BT_CONNECTED) { 6789 BT_DBG("queueing pending rx skb"); 6790 skb_queue_tail(&conn->pending_rx, skb); 6791 return; 6792 } 6793 6794 skb_pull(skb, L2CAP_HDR_SIZE); 6795 cid = __le16_to_cpu(lh->cid); 6796 len = __le16_to_cpu(lh->len); 6797 6798 if (len != skb->len) { 6799 kfree_skb(skb); 6800 return; 6801 } 6802 6803 /* Since we can't actively block incoming LE connections we must 6804 * at least ensure that we ignore incoming data from them. 6805 */ 6806 if (hcon->type == LE_LINK && 6807 hci_bdaddr_list_lookup(&hcon->hdev->reject_list, &hcon->dst, 6808 bdaddr_dst_type(hcon))) { 6809 kfree_skb(skb); 6810 return; 6811 } 6812 6813 BT_DBG("len %d, cid 0x%4.4x", len, cid); 6814 6815 switch (cid) { 6816 case L2CAP_CID_SIGNALING: 6817 l2cap_sig_channel(conn, skb); 6818 break; 6819 6820 case L2CAP_CID_CONN_LESS: 6821 psm = get_unaligned((__le16 *) skb->data); 6822 skb_pull(skb, L2CAP_PSMLEN_SIZE); 6823 l2cap_conless_channel(conn, psm, skb); 6824 break; 6825 6826 case L2CAP_CID_LE_SIGNALING: 6827 l2cap_le_sig_channel(conn, skb); 6828 break; 6829 6830 default: 6831 l2cap_data_channel(conn, cid, skb); 6832 break; 6833 } 6834 } 6835 process_pending_rx(struct work_struct * work)6836 static void process_pending_rx(struct work_struct *work) 6837 { 6838 struct l2cap_conn *conn = container_of(work, struct l2cap_conn, 6839 pending_rx_work); 6840 struct sk_buff *skb; 6841 6842 BT_DBG(""); 6843 6844 while ((skb = skb_dequeue(&conn->pending_rx))) 6845 l2cap_recv_frame(conn, skb); 6846 } 6847 l2cap_conn_add(struct hci_conn * hcon)6848 static struct l2cap_conn *l2cap_conn_add(struct hci_conn *hcon) 6849 { 6850 struct l2cap_conn *conn = hcon->l2cap_data; 6851 struct hci_chan *hchan; 6852 6853 if (conn) 6854 return conn; 6855 6856 hchan = hci_chan_create(hcon); 6857 if (!hchan) 6858 return NULL; 6859 6860 conn = kzalloc(sizeof(*conn), GFP_KERNEL); 6861 if (!conn) { 6862 hci_chan_del(hchan); 6863 return NULL; 6864 } 6865 6866 kref_init(&conn->ref); 6867 hcon->l2cap_data = conn; 6868 conn->hcon = hci_conn_get(hcon); 6869 conn->hchan = hchan; 6870 6871 BT_DBG("hcon %p conn %p hchan %p", hcon, conn, hchan); 6872 6873 conn->mtu = hcon->mtu; 6874 conn->feat_mask = 0; 6875 6876 conn->local_fixed_chan = L2CAP_FC_SIG_BREDR | L2CAP_FC_CONNLESS; 6877 6878 if (hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED) && 6879 (bredr_sc_enabled(hcon->hdev) || 6880 hci_dev_test_flag(hcon->hdev, HCI_FORCE_BREDR_SMP))) 6881 conn->local_fixed_chan |= L2CAP_FC_SMP_BREDR; 6882 6883 mutex_init(&conn->ident_lock); 6884 mutex_init(&conn->chan_lock); 6885 6886 INIT_LIST_HEAD(&conn->chan_l); 6887 INIT_LIST_HEAD(&conn->users); 6888 6889 INIT_DELAYED_WORK(&conn->info_timer, l2cap_info_timeout); 6890 6891 skb_queue_head_init(&conn->pending_rx); 6892 INIT_WORK(&conn->pending_rx_work, process_pending_rx); 6893 INIT_DELAYED_WORK(&conn->id_addr_timer, l2cap_conn_update_id_addr); 6894 6895 conn->disc_reason = HCI_ERROR_REMOTE_USER_TERM; 6896 6897 return conn; 6898 } 6899 is_valid_psm(u16 psm,u8 dst_type)6900 static bool is_valid_psm(u16 psm, u8 dst_type) 6901 { 6902 if (!psm) 6903 return false; 6904 6905 if (bdaddr_type_is_le(dst_type)) 6906 return (psm <= 0x00ff); 6907 6908 /* PSM must be odd and lsb of upper byte must be 0 */ 6909 return ((psm & 0x0101) == 0x0001); 6910 } 6911 6912 struct l2cap_chan_data { 6913 struct l2cap_chan *chan; 6914 struct pid *pid; 6915 int count; 6916 }; 6917 l2cap_chan_by_pid(struct l2cap_chan * chan,void * data)6918 static void l2cap_chan_by_pid(struct l2cap_chan *chan, void *data) 6919 { 6920 struct l2cap_chan_data *d = data; 6921 struct pid *pid; 6922 6923 if (chan == d->chan) 6924 return; 6925 6926 if (!test_bit(FLAG_DEFER_SETUP, &chan->flags)) 6927 return; 6928 6929 pid = chan->ops->get_peer_pid(chan); 6930 6931 /* Only count deferred channels with the same PID/PSM */ 6932 if (d->pid != pid || chan->psm != d->chan->psm || chan->ident || 6933 chan->mode != L2CAP_MODE_EXT_FLOWCTL || chan->state != BT_CONNECT) 6934 return; 6935 6936 d->count++; 6937 } 6938 l2cap_chan_connect(struct l2cap_chan * chan,__le16 psm,u16 cid,bdaddr_t * dst,u8 dst_type,u16 timeout)6939 int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid, 6940 bdaddr_t *dst, u8 dst_type, u16 timeout) 6941 { 6942 struct l2cap_conn *conn; 6943 struct hci_conn *hcon; 6944 struct hci_dev *hdev; 6945 int err; 6946 6947 BT_DBG("%pMR -> %pMR (type %u) psm 0x%4.4x mode 0x%2.2x", &chan->src, 6948 dst, dst_type, __le16_to_cpu(psm), chan->mode); 6949 6950 hdev = hci_get_route(dst, &chan->src, chan->src_type); 6951 if (!hdev) 6952 return -EHOSTUNREACH; 6953 6954 hci_dev_lock(hdev); 6955 6956 if (!is_valid_psm(__le16_to_cpu(psm), dst_type) && !cid && 6957 chan->chan_type != L2CAP_CHAN_RAW) { 6958 err = -EINVAL; 6959 goto done; 6960 } 6961 6962 if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED && !psm) { 6963 err = -EINVAL; 6964 goto done; 6965 } 6966 6967 if (chan->chan_type == L2CAP_CHAN_FIXED && !cid) { 6968 err = -EINVAL; 6969 goto done; 6970 } 6971 6972 switch (chan->mode) { 6973 case L2CAP_MODE_BASIC: 6974 break; 6975 case L2CAP_MODE_LE_FLOWCTL: 6976 break; 6977 case L2CAP_MODE_EXT_FLOWCTL: 6978 if (!enable_ecred) { 6979 err = -EOPNOTSUPP; 6980 goto done; 6981 } 6982 break; 6983 case L2CAP_MODE_ERTM: 6984 case L2CAP_MODE_STREAMING: 6985 if (!disable_ertm) 6986 break; 6987 fallthrough; 6988 default: 6989 err = -EOPNOTSUPP; 6990 goto done; 6991 } 6992 6993 switch (chan->state) { 6994 case BT_CONNECT: 6995 case BT_CONNECT2: 6996 case BT_CONFIG: 6997 /* Already connecting */ 6998 err = 0; 6999 goto done; 7000 7001 case BT_CONNECTED: 7002 /* Already connected */ 7003 err = -EISCONN; 7004 goto done; 7005 7006 case BT_OPEN: 7007 case BT_BOUND: 7008 /* Can connect */ 7009 break; 7010 7011 default: 7012 err = -EBADFD; 7013 goto done; 7014 } 7015 7016 /* Set destination address and psm */ 7017 bacpy(&chan->dst, dst); 7018 chan->dst_type = dst_type; 7019 7020 chan->psm = psm; 7021 chan->dcid = cid; 7022 7023 if (bdaddr_type_is_le(dst_type)) { 7024 /* Convert from L2CAP channel address type to HCI address type 7025 */ 7026 if (dst_type == BDADDR_LE_PUBLIC) 7027 dst_type = ADDR_LE_DEV_PUBLIC; 7028 else 7029 dst_type = ADDR_LE_DEV_RANDOM; 7030 7031 if (hci_dev_test_flag(hdev, HCI_ADVERTISING)) 7032 hcon = hci_connect_le(hdev, dst, dst_type, false, 7033 chan->sec_level, timeout, 7034 HCI_ROLE_SLAVE, 0, 0); 7035 else 7036 hcon = hci_connect_le_scan(hdev, dst, dst_type, 7037 chan->sec_level, timeout, 7038 CONN_REASON_L2CAP_CHAN); 7039 7040 } else { 7041 u8 auth_type = l2cap_get_auth_type(chan); 7042 hcon = hci_connect_acl(hdev, dst, chan->sec_level, auth_type, 7043 CONN_REASON_L2CAP_CHAN, timeout); 7044 } 7045 7046 if (IS_ERR(hcon)) { 7047 err = PTR_ERR(hcon); 7048 goto done; 7049 } 7050 7051 conn = l2cap_conn_add(hcon); 7052 if (!conn) { 7053 hci_conn_drop(hcon); 7054 err = -ENOMEM; 7055 goto done; 7056 } 7057 7058 if (chan->mode == L2CAP_MODE_EXT_FLOWCTL) { 7059 struct l2cap_chan_data data; 7060 7061 data.chan = chan; 7062 data.pid = chan->ops->get_peer_pid(chan); 7063 data.count = 1; 7064 7065 l2cap_chan_list(conn, l2cap_chan_by_pid, &data); 7066 7067 /* Check if there isn't too many channels being connected */ 7068 if (data.count > L2CAP_ECRED_CONN_SCID_MAX) { 7069 hci_conn_drop(hcon); 7070 err = -EPROTO; 7071 goto done; 7072 } 7073 } 7074 7075 mutex_lock(&conn->chan_lock); 7076 l2cap_chan_lock(chan); 7077 7078 if (cid && __l2cap_get_chan_by_dcid(conn, cid)) { 7079 hci_conn_drop(hcon); 7080 err = -EBUSY; 7081 goto chan_unlock; 7082 } 7083 7084 /* Update source addr of the socket */ 7085 bacpy(&chan->src, &hcon->src); 7086 chan->src_type = bdaddr_src_type(hcon); 7087 7088 __l2cap_chan_add(conn, chan); 7089 7090 /* l2cap_chan_add takes its own ref so we can drop this one */ 7091 hci_conn_drop(hcon); 7092 7093 l2cap_state_change(chan, BT_CONNECT); 7094 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan)); 7095 7096 /* Release chan->sport so that it can be reused by other 7097 * sockets (as it's only used for listening sockets). 7098 */ 7099 write_lock(&chan_list_lock); 7100 chan->sport = 0; 7101 write_unlock(&chan_list_lock); 7102 7103 if (hcon->state == BT_CONNECTED) { 7104 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) { 7105 __clear_chan_timer(chan); 7106 if (l2cap_chan_check_security(chan, true)) 7107 l2cap_state_change(chan, BT_CONNECTED); 7108 } else 7109 l2cap_do_start(chan); 7110 } 7111 7112 err = 0; 7113 7114 chan_unlock: 7115 l2cap_chan_unlock(chan); 7116 mutex_unlock(&conn->chan_lock); 7117 done: 7118 hci_dev_unlock(hdev); 7119 hci_dev_put(hdev); 7120 return err; 7121 } 7122 EXPORT_SYMBOL_GPL(l2cap_chan_connect); 7123 l2cap_ecred_reconfigure(struct l2cap_chan * chan)7124 static void l2cap_ecred_reconfigure(struct l2cap_chan *chan) 7125 { 7126 struct l2cap_conn *conn = chan->conn; 7127 DEFINE_RAW_FLEX(struct l2cap_ecred_reconf_req, pdu, scid, 1); 7128 7129 pdu->mtu = cpu_to_le16(chan->imtu); 7130 pdu->mps = cpu_to_le16(chan->mps); 7131 pdu->scid[0] = cpu_to_le16(chan->scid); 7132 7133 chan->ident = l2cap_get_ident(conn); 7134 7135 l2cap_send_cmd(conn, chan->ident, L2CAP_ECRED_RECONF_REQ, 7136 sizeof(pdu), &pdu); 7137 } 7138 l2cap_chan_reconfigure(struct l2cap_chan * chan,__u16 mtu)7139 int l2cap_chan_reconfigure(struct l2cap_chan *chan, __u16 mtu) 7140 { 7141 if (chan->imtu > mtu) 7142 return -EINVAL; 7143 7144 BT_DBG("chan %p mtu 0x%4.4x", chan, mtu); 7145 7146 chan->imtu = mtu; 7147 7148 l2cap_ecred_reconfigure(chan); 7149 7150 return 0; 7151 } 7152 7153 /* ---- L2CAP interface with lower layer (HCI) ---- */ 7154 l2cap_connect_ind(struct hci_dev * hdev,bdaddr_t * bdaddr)7155 int l2cap_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr) 7156 { 7157 int exact = 0, lm1 = 0, lm2 = 0; 7158 struct l2cap_chan *c; 7159 7160 BT_DBG("hdev %s, bdaddr %pMR", hdev->name, bdaddr); 7161 7162 /* Find listening sockets and check their link_mode */ 7163 read_lock(&chan_list_lock); 7164 list_for_each_entry(c, &chan_list, global_l) { 7165 if (c->state != BT_LISTEN) 7166 continue; 7167 7168 if (!bacmp(&c->src, &hdev->bdaddr)) { 7169 lm1 |= HCI_LM_ACCEPT; 7170 if (test_bit(FLAG_ROLE_SWITCH, &c->flags)) 7171 lm1 |= HCI_LM_MASTER; 7172 exact++; 7173 } else if (!bacmp(&c->src, BDADDR_ANY)) { 7174 lm2 |= HCI_LM_ACCEPT; 7175 if (test_bit(FLAG_ROLE_SWITCH, &c->flags)) 7176 lm2 |= HCI_LM_MASTER; 7177 } 7178 } 7179 read_unlock(&chan_list_lock); 7180 7181 return exact ? lm1 : lm2; 7182 } 7183 7184 /* Find the next fixed channel in BT_LISTEN state, continue iteration 7185 * from an existing channel in the list or from the beginning of the 7186 * global list (by passing NULL as first parameter). 7187 */ l2cap_global_fixed_chan(struct l2cap_chan * c,struct hci_conn * hcon)7188 static struct l2cap_chan *l2cap_global_fixed_chan(struct l2cap_chan *c, 7189 struct hci_conn *hcon) 7190 { 7191 u8 src_type = bdaddr_src_type(hcon); 7192 7193 read_lock(&chan_list_lock); 7194 7195 if (c) 7196 c = list_next_entry(c, global_l); 7197 else 7198 c = list_entry(chan_list.next, typeof(*c), global_l); 7199 7200 list_for_each_entry_from(c, &chan_list, global_l) { 7201 if (c->chan_type != L2CAP_CHAN_FIXED) 7202 continue; 7203 if (c->state != BT_LISTEN) 7204 continue; 7205 if (bacmp(&c->src, &hcon->src) && bacmp(&c->src, BDADDR_ANY)) 7206 continue; 7207 if (src_type != c->src_type) 7208 continue; 7209 7210 c = l2cap_chan_hold_unless_zero(c); 7211 read_unlock(&chan_list_lock); 7212 return c; 7213 } 7214 7215 read_unlock(&chan_list_lock); 7216 7217 return NULL; 7218 } 7219 l2cap_connect_cfm(struct hci_conn * hcon,u8 status)7220 static void l2cap_connect_cfm(struct hci_conn *hcon, u8 status) 7221 { 7222 struct hci_dev *hdev = hcon->hdev; 7223 struct l2cap_conn *conn; 7224 struct l2cap_chan *pchan; 7225 u8 dst_type; 7226 7227 if (hcon->type != ACL_LINK && hcon->type != LE_LINK) 7228 return; 7229 7230 BT_DBG("hcon %p bdaddr %pMR status %d", hcon, &hcon->dst, status); 7231 7232 if (status) { 7233 l2cap_conn_del(hcon, bt_to_errno(status)); 7234 return; 7235 } 7236 7237 conn = l2cap_conn_add(hcon); 7238 if (!conn) 7239 return; 7240 7241 dst_type = bdaddr_dst_type(hcon); 7242 7243 /* If device is blocked, do not create channels for it */ 7244 if (hci_bdaddr_list_lookup(&hdev->reject_list, &hcon->dst, dst_type)) 7245 return; 7246 7247 /* Find fixed channels and notify them of the new connection. We 7248 * use multiple individual lookups, continuing each time where 7249 * we left off, because the list lock would prevent calling the 7250 * potentially sleeping l2cap_chan_lock() function. 7251 */ 7252 pchan = l2cap_global_fixed_chan(NULL, hcon); 7253 while (pchan) { 7254 struct l2cap_chan *chan, *next; 7255 7256 /* Client fixed channels should override server ones */ 7257 if (__l2cap_get_chan_by_dcid(conn, pchan->scid)) 7258 goto next; 7259 7260 l2cap_chan_lock(pchan); 7261 chan = pchan->ops->new_connection(pchan); 7262 if (chan) { 7263 bacpy(&chan->src, &hcon->src); 7264 bacpy(&chan->dst, &hcon->dst); 7265 chan->src_type = bdaddr_src_type(hcon); 7266 chan->dst_type = dst_type; 7267 7268 __l2cap_chan_add(conn, chan); 7269 } 7270 7271 l2cap_chan_unlock(pchan); 7272 next: 7273 next = l2cap_global_fixed_chan(pchan, hcon); 7274 l2cap_chan_put(pchan); 7275 pchan = next; 7276 } 7277 7278 l2cap_conn_ready(conn); 7279 } 7280 l2cap_disconn_ind(struct hci_conn * hcon)7281 int l2cap_disconn_ind(struct hci_conn *hcon) 7282 { 7283 struct l2cap_conn *conn = hcon->l2cap_data; 7284 7285 BT_DBG("hcon %p", hcon); 7286 7287 if (!conn) 7288 return HCI_ERROR_REMOTE_USER_TERM; 7289 return conn->disc_reason; 7290 } 7291 l2cap_disconn_cfm(struct hci_conn * hcon,u8 reason)7292 static void l2cap_disconn_cfm(struct hci_conn *hcon, u8 reason) 7293 { 7294 if (hcon->type != ACL_LINK && hcon->type != LE_LINK) 7295 return; 7296 7297 BT_DBG("hcon %p reason %d", hcon, reason); 7298 7299 l2cap_conn_del(hcon, bt_to_errno(reason)); 7300 } 7301 l2cap_check_encryption(struct l2cap_chan * chan,u8 encrypt)7302 static inline void l2cap_check_encryption(struct l2cap_chan *chan, u8 encrypt) 7303 { 7304 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) 7305 return; 7306 7307 if (encrypt == 0x00) { 7308 if (chan->sec_level == BT_SECURITY_MEDIUM) { 7309 __set_chan_timer(chan, L2CAP_ENC_TIMEOUT); 7310 } else if (chan->sec_level == BT_SECURITY_HIGH || 7311 chan->sec_level == BT_SECURITY_FIPS) 7312 l2cap_chan_close(chan, ECONNREFUSED); 7313 } else { 7314 if (chan->sec_level == BT_SECURITY_MEDIUM) 7315 __clear_chan_timer(chan); 7316 } 7317 } 7318 l2cap_security_cfm(struct hci_conn * hcon,u8 status,u8 encrypt)7319 static void l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt) 7320 { 7321 struct l2cap_conn *conn = hcon->l2cap_data; 7322 struct l2cap_chan *chan; 7323 7324 if (!conn) 7325 return; 7326 7327 BT_DBG("conn %p status 0x%2.2x encrypt %u", conn, status, encrypt); 7328 7329 mutex_lock(&conn->chan_lock); 7330 7331 list_for_each_entry(chan, &conn->chan_l, list) { 7332 l2cap_chan_lock(chan); 7333 7334 BT_DBG("chan %p scid 0x%4.4x state %s", chan, chan->scid, 7335 state_to_string(chan->state)); 7336 7337 if (!status && encrypt) 7338 chan->sec_level = hcon->sec_level; 7339 7340 if (!__l2cap_no_conn_pending(chan)) { 7341 l2cap_chan_unlock(chan); 7342 continue; 7343 } 7344 7345 if (!status && (chan->state == BT_CONNECTED || 7346 chan->state == BT_CONFIG)) { 7347 chan->ops->resume(chan); 7348 l2cap_check_encryption(chan, encrypt); 7349 l2cap_chan_unlock(chan); 7350 continue; 7351 } 7352 7353 if (chan->state == BT_CONNECT) { 7354 if (!status && l2cap_check_enc_key_size(hcon)) 7355 l2cap_start_connection(chan); 7356 else 7357 __set_chan_timer(chan, L2CAP_DISC_TIMEOUT); 7358 } else if (chan->state == BT_CONNECT2 && 7359 !(chan->mode == L2CAP_MODE_EXT_FLOWCTL || 7360 chan->mode == L2CAP_MODE_LE_FLOWCTL)) { 7361 struct l2cap_conn_rsp rsp; 7362 __u16 res, stat; 7363 7364 if (!status && l2cap_check_enc_key_size(hcon)) { 7365 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) { 7366 res = L2CAP_CR_PEND; 7367 stat = L2CAP_CS_AUTHOR_PEND; 7368 chan->ops->defer(chan); 7369 } else { 7370 l2cap_state_change(chan, BT_CONFIG); 7371 res = L2CAP_CR_SUCCESS; 7372 stat = L2CAP_CS_NO_INFO; 7373 } 7374 } else { 7375 l2cap_state_change(chan, BT_DISCONN); 7376 __set_chan_timer(chan, L2CAP_DISC_TIMEOUT); 7377 res = L2CAP_CR_SEC_BLOCK; 7378 stat = L2CAP_CS_NO_INFO; 7379 } 7380 7381 rsp.scid = cpu_to_le16(chan->dcid); 7382 rsp.dcid = cpu_to_le16(chan->scid); 7383 rsp.result = cpu_to_le16(res); 7384 rsp.status = cpu_to_le16(stat); 7385 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP, 7386 sizeof(rsp), &rsp); 7387 7388 if (!test_bit(CONF_REQ_SENT, &chan->conf_state) && 7389 res == L2CAP_CR_SUCCESS) { 7390 char buf[128]; 7391 set_bit(CONF_REQ_SENT, &chan->conf_state); 7392 l2cap_send_cmd(conn, l2cap_get_ident(conn), 7393 L2CAP_CONF_REQ, 7394 l2cap_build_conf_req(chan, buf, sizeof(buf)), 7395 buf); 7396 chan->num_conf_req++; 7397 } 7398 } 7399 7400 l2cap_chan_unlock(chan); 7401 } 7402 7403 mutex_unlock(&conn->chan_lock); 7404 } 7405 7406 /* Append fragment into frame respecting the maximum len of rx_skb */ l2cap_recv_frag(struct l2cap_conn * conn,struct sk_buff * skb,u16 len)7407 static int l2cap_recv_frag(struct l2cap_conn *conn, struct sk_buff *skb, 7408 u16 len) 7409 { 7410 if (!conn->rx_skb) { 7411 /* Allocate skb for the complete frame (with header) */ 7412 conn->rx_skb = bt_skb_alloc(len, GFP_KERNEL); 7413 if (!conn->rx_skb) 7414 return -ENOMEM; 7415 /* Init rx_len */ 7416 conn->rx_len = len; 7417 } 7418 7419 /* Copy as much as the rx_skb can hold */ 7420 len = min_t(u16, len, skb->len); 7421 skb_copy_from_linear_data(skb, skb_put(conn->rx_skb, len), len); 7422 skb_pull(skb, len); 7423 conn->rx_len -= len; 7424 7425 return len; 7426 } 7427 l2cap_recv_len(struct l2cap_conn * conn,struct sk_buff * skb)7428 static int l2cap_recv_len(struct l2cap_conn *conn, struct sk_buff *skb) 7429 { 7430 struct sk_buff *rx_skb; 7431 int len; 7432 7433 /* Append just enough to complete the header */ 7434 len = l2cap_recv_frag(conn, skb, L2CAP_LEN_SIZE - conn->rx_skb->len); 7435 7436 /* If header could not be read just continue */ 7437 if (len < 0 || conn->rx_skb->len < L2CAP_LEN_SIZE) 7438 return len; 7439 7440 rx_skb = conn->rx_skb; 7441 len = get_unaligned_le16(rx_skb->data); 7442 7443 /* Check if rx_skb has enough space to received all fragments */ 7444 if (len + (L2CAP_HDR_SIZE - L2CAP_LEN_SIZE) <= skb_tailroom(rx_skb)) { 7445 /* Update expected len */ 7446 conn->rx_len = len + (L2CAP_HDR_SIZE - L2CAP_LEN_SIZE); 7447 return L2CAP_LEN_SIZE; 7448 } 7449 7450 /* Reset conn->rx_skb since it will need to be reallocated in order to 7451 * fit all fragments. 7452 */ 7453 conn->rx_skb = NULL; 7454 7455 /* Reallocates rx_skb using the exact expected length */ 7456 len = l2cap_recv_frag(conn, rx_skb, 7457 len + (L2CAP_HDR_SIZE - L2CAP_LEN_SIZE)); 7458 kfree_skb(rx_skb); 7459 7460 return len; 7461 } 7462 l2cap_recv_reset(struct l2cap_conn * conn)7463 static void l2cap_recv_reset(struct l2cap_conn *conn) 7464 { 7465 kfree_skb(conn->rx_skb); 7466 conn->rx_skb = NULL; 7467 conn->rx_len = 0; 7468 } 7469 l2cap_recv_acldata(struct hci_conn * hcon,struct sk_buff * skb,u16 flags)7470 void l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 flags) 7471 { 7472 struct l2cap_conn *conn = hcon->l2cap_data; 7473 int len; 7474 7475 if (!conn) 7476 conn = l2cap_conn_add(hcon); 7477 7478 if (!conn) 7479 goto drop; 7480 7481 BT_DBG("conn %p len %u flags 0x%x", conn, skb->len, flags); 7482 7483 switch (flags) { 7484 case ACL_START: 7485 case ACL_START_NO_FLUSH: 7486 case ACL_COMPLETE: 7487 if (conn->rx_skb) { 7488 BT_ERR("Unexpected start frame (len %d)", skb->len); 7489 l2cap_recv_reset(conn); 7490 l2cap_conn_unreliable(conn, ECOMM); 7491 } 7492 7493 /* Start fragment may not contain the L2CAP length so just 7494 * copy the initial byte when that happens and use conn->mtu as 7495 * expected length. 7496 */ 7497 if (skb->len < L2CAP_LEN_SIZE) { 7498 l2cap_recv_frag(conn, skb, conn->mtu); 7499 break; 7500 } 7501 7502 len = get_unaligned_le16(skb->data) + L2CAP_HDR_SIZE; 7503 7504 if (len == skb->len) { 7505 /* Complete frame received */ 7506 l2cap_recv_frame(conn, skb); 7507 return; 7508 } 7509 7510 BT_DBG("Start: total len %d, frag len %u", len, skb->len); 7511 7512 if (skb->len > len) { 7513 BT_ERR("Frame is too long (len %u, expected len %d)", 7514 skb->len, len); 7515 l2cap_conn_unreliable(conn, ECOMM); 7516 goto drop; 7517 } 7518 7519 /* Append fragment into frame (with header) */ 7520 if (l2cap_recv_frag(conn, skb, len) < 0) 7521 goto drop; 7522 7523 break; 7524 7525 case ACL_CONT: 7526 BT_DBG("Cont: frag len %u (expecting %u)", skb->len, conn->rx_len); 7527 7528 if (!conn->rx_skb) { 7529 BT_ERR("Unexpected continuation frame (len %d)", skb->len); 7530 l2cap_conn_unreliable(conn, ECOMM); 7531 goto drop; 7532 } 7533 7534 /* Complete the L2CAP length if it has not been read */ 7535 if (conn->rx_skb->len < L2CAP_LEN_SIZE) { 7536 if (l2cap_recv_len(conn, skb) < 0) { 7537 l2cap_conn_unreliable(conn, ECOMM); 7538 goto drop; 7539 } 7540 7541 /* Header still could not be read just continue */ 7542 if (conn->rx_skb->len < L2CAP_LEN_SIZE) 7543 break; 7544 } 7545 7546 if (skb->len > conn->rx_len) { 7547 BT_ERR("Fragment is too long (len %u, expected %u)", 7548 skb->len, conn->rx_len); 7549 l2cap_recv_reset(conn); 7550 l2cap_conn_unreliable(conn, ECOMM); 7551 goto drop; 7552 } 7553 7554 /* Append fragment into frame (with header) */ 7555 l2cap_recv_frag(conn, skb, skb->len); 7556 7557 if (!conn->rx_len) { 7558 /* Complete frame received. l2cap_recv_frame 7559 * takes ownership of the skb so set the global 7560 * rx_skb pointer to NULL first. 7561 */ 7562 struct sk_buff *rx_skb = conn->rx_skb; 7563 conn->rx_skb = NULL; 7564 l2cap_recv_frame(conn, rx_skb); 7565 } 7566 break; 7567 } 7568 7569 drop: 7570 kfree_skb(skb); 7571 } 7572 7573 static struct hci_cb l2cap_cb = { 7574 .name = "L2CAP", 7575 .connect_cfm = l2cap_connect_cfm, 7576 .disconn_cfm = l2cap_disconn_cfm, 7577 .security_cfm = l2cap_security_cfm, 7578 }; 7579 l2cap_debugfs_show(struct seq_file * f,void * p)7580 static int l2cap_debugfs_show(struct seq_file *f, void *p) 7581 { 7582 struct l2cap_chan *c; 7583 7584 read_lock(&chan_list_lock); 7585 7586 list_for_each_entry(c, &chan_list, global_l) { 7587 seq_printf(f, "%pMR (%u) %pMR (%u) %d %d 0x%4.4x 0x%4.4x %d %d %d %d\n", 7588 &c->src, c->src_type, &c->dst, c->dst_type, 7589 c->state, __le16_to_cpu(c->psm), 7590 c->scid, c->dcid, c->imtu, c->omtu, 7591 c->sec_level, c->mode); 7592 } 7593 7594 read_unlock(&chan_list_lock); 7595 7596 return 0; 7597 } 7598 7599 DEFINE_SHOW_ATTRIBUTE(l2cap_debugfs); 7600 7601 static struct dentry *l2cap_debugfs; 7602 l2cap_init(void)7603 int __init l2cap_init(void) 7604 { 7605 int err; 7606 7607 err = l2cap_init_sockets(); 7608 if (err < 0) 7609 return err; 7610 7611 hci_register_cb(&l2cap_cb); 7612 7613 if (IS_ERR_OR_NULL(bt_debugfs)) 7614 return 0; 7615 7616 l2cap_debugfs = debugfs_create_file("l2cap", 0444, bt_debugfs, 7617 NULL, &l2cap_debugfs_fops); 7618 7619 return 0; 7620 } 7621 l2cap_exit(void)7622 void l2cap_exit(void) 7623 { 7624 debugfs_remove(l2cap_debugfs); 7625 hci_unregister_cb(&l2cap_cb); 7626 l2cap_cleanup_sockets(); 7627 } 7628 7629 module_param(disable_ertm, bool, 0644); 7630 MODULE_PARM_DESC(disable_ertm, "Disable enhanced retransmission mode"); 7631 7632 module_param(enable_ecred, bool, 0644); 7633 MODULE_PARM_DESC(enable_ecred, "Enable enhanced credit flow control mode"); 7634