net/bluetooth/l2cap_core.c

   1 /*
   2    BlueZ - Bluetooth protocol stack for Linux
   3    Copyright (C) 2000-2001 Qualcomm Incorporated
   4    Copyright (C) 2009-2010 Gustavo F. Padovan <gustavo@padovan.org>
   5    Copyright (C) 2010 Google Inc.
   6    Copyright (C) 2011 ProFUSION Embedded Systems
   7    Copyright (c) 2012 Code Aurora Forum.  All rights reserved.
   8
   9    Written 2000,2001 by Maxim Krasnyansky <maxk@qualcomm.com>
  10
  11    This program is free software; you can redistribute it and/or modify
  12    it under the terms of the GNU General Public License version 2 as
  13    published by the Free Software Foundation;
  14
  15    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  16    OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
  18    IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
  19    CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
  20    WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  21    ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  22    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  23
  24    ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
  25    COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
  26    SOFTWARE IS DISCLAIMED.
  27 */
  28
  29 /* Bluetooth L2CAP core. */
  30
  31 #include <linux/module.h>
  32
  33 #include <linux/debugfs.h>
  34 #include <linux/crc16.h>
  35 #include <linux/filter.h>
  36
  37 #include <net/bluetooth/bluetooth.h>
  38 #include <net/bluetooth/hci_core.h>
  39 #include <net/bluetooth/l2cap.h>
  40
  41 #include "smp.h"
  42 #include "a2mp.h"
  43 #include "amp.h"
  44
  45 #define LE_FLOWCTL_MAX_CREDITS 65535
  46
  47 bool disable_ertm;
  48
  49 static u32 l2cap_feat_mask = L2CAP_FEAT_FIXED_CHAN | L2CAP_FEAT_UCD;
  50
  51 static LIST_HEAD(chan_list);
  52 static DEFINE_RWLOCK(chan_list_lock);
  53
  54 static u16 le_max_credits = L2CAP_LE_MAX_CREDITS;
  55 static u16 le_default_mps = L2CAP_LE_DEFAULT_MPS;
  56
  57 static struct sk_buff *l2cap_build_cmd(struct l2cap_conn *conn,
  58                                        u8 code, u8 ident, u16 dlen, void *data);
  59 static void l2cap_send_cmd(struct l2cap_conn *conn, u8 ident, u8 code, u16 len,
  60                            void *data);
  61 static int l2cap_build_conf_req(struct l2cap_chan *chan, void *data);
  62 static void l2cap_send_disconn_req(struct l2cap_chan *chan, int err);
  63
  64 static void l2cap_tx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
  65                      struct sk_buff_head *skbs, u8 event);
  66
  67 static inline u8 bdaddr_type(u8 link_type, u8 bdaddr_type)
  68 {
  69         if (link_type == LE_LINK) {
  70                 if (bdaddr_type == ADDR_LE_DEV_PUBLIC)
  71                         return BDADDR_LE_PUBLIC;
  72                 else
  73                         return BDADDR_LE_RANDOM;
  74         }
  75
  76         return BDADDR_BREDR;
  77 }
  78
  79 static inline u8 bdaddr_src_type(struct hci_conn *hcon)
  80 {
  81         return bdaddr_type(hcon->type, hcon->src_type);
  82 }
  83
  84 static inline u8 bdaddr_dst_type(struct hci_conn *hcon)
  85 {
  86         return bdaddr_type(hcon->type, hcon->dst_type);
  87 }
  88
  89 /* ---- L2CAP channels ---- */
  90
  91 static struct l2cap_chan *__l2cap_get_chan_by_dcid(struct l2cap_conn *conn,
  92                                                    u16 cid)
  93 {
  94         struct l2cap_chan *c;
  95
  96         list_for_each_entry(c, &conn->chan_l, list) {
  97                 if (c->dcid == cid)
  98                         return c;
  99         }
 100         return NULL;
 101 }
 102
 103 static struct l2cap_chan *__l2cap_get_chan_by_scid(struct l2cap_conn *conn,
 104                                                    u16 cid)
 105 {
 106         struct l2cap_chan *c;
 107
 108         list_for_each_entry(c, &conn->chan_l, list) {
 109                 if (c->scid == cid)
 110                         return c;
 111         }
 112         return NULL;
 113 }
 114
 115 /* Find channel with given SCID.
 116  * Returns locked channel. */
 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                 l2cap_chan_lock(c);
 126         mutex_unlock(&conn->chan_lock);
 127
 128         return c;
 129 }
 130
 131 /* Find channel with given DCID.
 132  * Returns locked channel.
 133  */
 134 static struct l2cap_chan *l2cap_get_chan_by_dcid(struct l2cap_conn *conn,
 135                                                  u16 cid)
 136 {
 137         struct l2cap_chan *c;
 138
 139         mutex_lock(&conn->chan_lock);
 140         c = __l2cap_get_chan_by_dcid(conn, cid);
 141         if (c)
 142                 l2cap_chan_lock(c);
 143         mutex_unlock(&conn->chan_lock);
 144
 145         return c;
 146 }
 147
 148 static struct l2cap_chan *__l2cap_get_chan_by_ident(struct l2cap_conn *conn,
 149                                                     u8 ident)
 150 {
 151         struct l2cap_chan *c;
 152
 153         list_for_each_entry(c, &conn->chan_l, list) {
 154                 if (c->ident == ident)
 155                         return c;
 156         }
 157         return NULL;
 158 }
 159
 160 static struct l2cap_chan *l2cap_get_chan_by_ident(struct l2cap_conn *conn,
 161                                                   u8 ident)
 162 {
 163         struct l2cap_chan *c;
 164
 165         mutex_lock(&conn->chan_lock);
 166         c = __l2cap_get_chan_by_ident(conn, ident);
 167         if (c)
 168                 l2cap_chan_lock(c);
 169         mutex_unlock(&conn->chan_lock);
 170
 171         return c;
 172 }
 173
 174 static struct l2cap_chan *__l2cap_global_chan_by_addr(__le16 psm, bdaddr_t *src)
 175 {
 176         struct l2cap_chan *c;
 177
 178         list_for_each_entry(c, &chan_list, global_l) {
 179                 if (c->sport == psm && !bacmp(&c->src, src))
 180                         return c;
 181         }
 182         return NULL;
 183 }
 184
 185 int l2cap_add_psm(struct l2cap_chan *chan, bdaddr_t *src, __le16 psm)
 186 {
 187         int err;
 188
 189         write_lock(&chan_list_lock);
 190
 191         if (psm && __l2cap_global_chan_by_addr(psm, src)) {
 192                 err = -EADDRINUSE;
 193                 goto done;
 194         }
 195
 196         if (psm) {
 197                 chan->psm = psm;
 198                 chan->sport = psm;
 199                 err = 0;
 200         } else {
 201                 u16 p, start, end, incr;
 202
 203                 if (chan->src_type == BDADDR_BREDR) {
 204                         start = L2CAP_PSM_DYN_START;
 205                         end = L2CAP_PSM_AUTO_END;
 206                         incr = 2;
 207                 } else {
 208                         start = L2CAP_PSM_LE_DYN_START;
 209                         end = L2CAP_PSM_LE_DYN_END;
 210                         incr = 1;
 211                 }
 212
 213                 err = -EINVAL;
 214                 for (p = start; p <= end; p += incr)
 215                         if (!__l2cap_global_chan_by_addr(cpu_to_le16(p), src)) {
 216                                 chan->psm   = cpu_to_le16(p);
 217                                 chan->sport = cpu_to_le16(p);
 218                                 err = 0;
 219                                 break;
 220                         }
 221         }
 222
 223 done:
 224         write_unlock(&chan_list_lock);
 225         return err;
 226 }
 227 EXPORT_SYMBOL_GPL(l2cap_add_psm);
 228
 229 int l2cap_add_scid(struct l2cap_chan *chan,  __u16 scid)
 230 {
 231         write_lock(&chan_list_lock);
 232
 233         /* Override the defaults (which are for conn-oriented) */
 234         chan->omtu = L2CAP_DEFAULT_MTU;
 235         chan->chan_type = L2CAP_CHAN_FIXED;
 236
 237         chan->scid = scid;
 238
 239         write_unlock(&chan_list_lock);
 240
 241         return 0;
 242 }
 243
 244 static u16 l2cap_alloc_cid(struct l2cap_conn *conn)
 245 {
 246         u16 cid, dyn_end;
 247
 248         if (conn->hcon->type == LE_LINK)
 249                 dyn_end = L2CAP_CID_LE_DYN_END;
 250         else
 251                 dyn_end = L2CAP_CID_DYN_END;
 252
 253         for (cid = L2CAP_CID_DYN_START; cid <= dyn_end; cid++) {
 254                 if (!__l2cap_get_chan_by_scid(conn, cid))
 255                         return cid;
 256         }
 257
 258         return 0;
 259 }
 260
 261 static void l2cap_state_change(struct l2cap_chan *chan, int state)
 262 {
 263         BT_DBG("chan %p %s -> %s", chan, state_to_string(chan->state),
 264                state_to_string(state));
 265
 266         chan->state = state;
 267         chan->ops->state_change(chan, state, 0);
 268 }
 269
 270 static inline void l2cap_state_change_and_error(struct l2cap_chan *chan,
 271                                                 int state, int err)
 272 {
 273         chan->state = state;
 274         chan->ops->state_change(chan, chan->state, err);
 275 }
 276
 277 static inline void l2cap_chan_set_err(struct l2cap_chan *chan, int err)
 278 {
 279         chan->ops->state_change(chan, chan->state, err);
 280 }
 281
 282 static void __set_retrans_timer(struct l2cap_chan *chan)
 283 {
 284         if (!delayed_work_pending(&chan->monitor_timer) &&
 285             chan->retrans_timeout) {
 286                 l2cap_set_timer(chan, &chan->retrans_timer,
 287                                 msecs_to_jiffies(chan->retrans_timeout));
 288         }
 289 }
 290
 291 static void __set_monitor_timer(struct l2cap_chan *chan)
 292 {
 293         __clear_retrans_timer(chan);
 294         if (chan->monitor_timeout) {
 295                 l2cap_set_timer(chan, &chan->monitor_timer,
 296                                 msecs_to_jiffies(chan->monitor_timeout));
 297         }
 298 }
 299
 300 static struct sk_buff *l2cap_ertm_seq_in_queue(struct sk_buff_head *head,
 301                                                u16 seq)
 302 {
 303         struct sk_buff *skb;
 304
 305         skb_queue_walk(head, skb) {
 306                 if (bt_cb(skb)->l2cap.txseq == seq)
 307                         return skb;
 308         }
 309
 310         return NULL;
 311 }
 312
 313 /* ---- L2CAP sequence number lists ---- */
 314
 315 /* For ERTM, ordered lists of sequence numbers must be tracked for
 316  * SREJ requests that are received and for frames that are to be
 317  * retransmitted. These seq_list functions implement a singly-linked
 318  * list in an array, where membership in the list can also be checked
 319  * in constant time. Items can also be added to the tail of the list
 320  * and removed from the head in constant time, without further memory
 321  * allocs or frees.
 322  */
 323
 324 static int l2cap_seq_list_init(struct l2cap_seq_list *seq_list, u16 size)
 325 {
 326         size_t alloc_size, i;
 327
 328         /* Allocated size is a power of 2 to map sequence numbers
 329          * (which may be up to 14 bits) in to a smaller array that is
 330          * sized for the negotiated ERTM transmit windows.
 331          */
 332         alloc_size = roundup_pow_of_two(size);
 333
 334         seq_list->list = kmalloc(sizeof(u16) * alloc_size, GFP_KERNEL);
 335         if (!seq_list->list)
 336                 return -ENOMEM;
 337
 338         seq_list->mask = alloc_size - 1;
 339         seq_list->head = L2CAP_SEQ_LIST_CLEAR;
 340         seq_list->tail = L2CAP_SEQ_LIST_CLEAR;
 341         for (i = 0; i < alloc_size; i++)
 342                 seq_list->list[i] = L2CAP_SEQ_LIST_CLEAR;
 343
 344         return 0;
 345 }
 346
 347 static inline void l2cap_seq_list_free(struct l2cap_seq_list *seq_list)
 348 {
 349         kfree(seq_list->list);
 350 }
 351
 352 static inline bool l2cap_seq_list_contains(struct l2cap_seq_list *seq_list,
 353                                            u16 seq)
 354 {
 355         /* Constant-time check for list membership */
 356         return seq_list->list[seq & seq_list->mask] != L2CAP_SEQ_LIST_CLEAR;
 357 }
 358
 359 static inline u16 l2cap_seq_list_pop(struct l2cap_seq_list *seq_list)
 360 {
 361         u16 seq = seq_list->head;
 362         u16 mask = seq_list->mask;
 363
 364         seq_list->head = seq_list->list[seq & mask];
 365         seq_list->list[seq & mask] = L2CAP_SEQ_LIST_CLEAR;
 366
 367         if (seq_list->head == L2CAP_SEQ_LIST_TAIL) {
 368                 seq_list->head = L2CAP_SEQ_LIST_CLEAR;
 369                 seq_list->tail = L2CAP_SEQ_LIST_CLEAR;
 370         }
 371
 372         return seq;
 373 }
 374
 375 static void l2cap_seq_list_clear(struct l2cap_seq_list *seq_list)
 376 {
 377         u16 i;
 378
 379         if (seq_list->head == L2CAP_SEQ_LIST_CLEAR)
 380                 return;
 381
 382         for (i = 0; i <= seq_list->mask; i++)
 383                 seq_list->list[i] = L2CAP_SEQ_LIST_CLEAR;
 384
 385         seq_list->head = L2CAP_SEQ_LIST_CLEAR;
 386         seq_list->tail = L2CAP_SEQ_LIST_CLEAR;
 387 }
 388
 389 static void l2cap_seq_list_append(struct l2cap_seq_list *seq_list, u16 seq)
 390 {
 391         u16 mask = seq_list->mask;
 392
 393         /* All appends happen in constant time */
 394
 395         if (seq_list->list[seq & mask] != L2CAP_SEQ_LIST_CLEAR)
 396                 return;
 397
 398         if (seq_list->tail == L2CAP_SEQ_LIST_CLEAR)
 399                 seq_list->head = seq;
 400         else
 401                 seq_list->list[seq_list->tail & mask] = seq;
 402
 403         seq_list->tail = seq;
 404         seq_list->list[seq & mask] = L2CAP_SEQ_LIST_TAIL;
 405 }
 406
 407 static void l2cap_chan_timeout(struct work_struct *work)
 408 {
 409         struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
 410                                                chan_timer.work);
 411         struct l2cap_conn *conn = chan->conn;
 412         int reason;
 413
 414         BT_DBG("chan %p state %s", chan, state_to_string(chan->state));
 415
 416         mutex_lock(&conn->chan_lock);
 417         l2cap_chan_lock(chan);
 418
 419         if (chan->state == BT_CONNECTED || chan->state == BT_CONFIG)
 420                 reason = ECONNREFUSED;
 421         else if (chan->state == BT_CONNECT &&
 422                  chan->sec_level != BT_SECURITY_SDP)
 423                 reason = ECONNREFUSED;
 424         else
 425                 reason = ETIMEDOUT;
 426
 427         l2cap_chan_close(chan, reason);
 428
 429         l2cap_chan_unlock(chan);
 430
 431         chan->ops->close(chan);
 432         mutex_unlock(&conn->chan_lock);
 433
 434         l2cap_chan_put(chan);
 435 }
 436
 437 struct l2cap_chan *l2cap_chan_create(void)
 438 {
 439         struct l2cap_chan *chan;
 440
 441         chan = kzalloc(sizeof(*chan), GFP_ATOMIC);
 442         if (!chan)
 443                 return NULL;
 444
 445         mutex_init(&chan->lock);
 446
 447         /* Set default lock nesting level */
 448         atomic_set(&chan->nesting, L2CAP_NESTING_NORMAL);
 449
 450         write_lock(&chan_list_lock);
 451         list_add(&chan->global_l, &chan_list);
 452         write_unlock(&chan_list_lock);
 453
 454         INIT_DELAYED_WORK(&chan->chan_timer, l2cap_chan_timeout);
 455
 456         chan->state = BT_OPEN;
 457
 458         kref_init(&chan->kref);
 459
 460         /* This flag is cleared in l2cap_chan_ready() */
 461         set_bit(CONF_NOT_COMPLETE, &chan->conf_state);
 462
 463         BT_DBG("chan %p", chan);
 464
 465         return chan;
 466 }
 467 EXPORT_SYMBOL_GPL(l2cap_chan_create);
 468
 469 static void l2cap_chan_destroy(struct kref *kref)
 470 {
 471         struct l2cap_chan *chan = container_of(kref, struct l2cap_chan, kref);
 472
 473         BT_DBG("chan %p", chan);
 474
 475         write_lock(&chan_list_lock);
 476         list_del(&chan->global_l);
 477         write_unlock(&chan_list_lock);
 478
 479         kfree(chan);
 480 }
 481
 482 void l2cap_chan_hold(struct l2cap_chan *c)
 483 {
 484         BT_DBG("chan %p orig refcnt %d", c, kref_read(&c->kref));
 485
 486         kref_get(&c->kref);
 487 }
 488
 489 void l2cap_chan_put(struct l2cap_chan *c)
 490 {
 491         BT_DBG("chan %p orig refcnt %d", c, kref_read(&c->kref));
 492
 493         kref_put(&c->kref, l2cap_chan_destroy);
 494 }
 495 EXPORT_SYMBOL_GPL(l2cap_chan_put);
 496
 497 void l2cap_chan_set_defaults(struct l2cap_chan *chan)
 498 {
 499         chan->fcs  = L2CAP_FCS_CRC16;
 500         chan->max_tx = L2CAP_DEFAULT_MAX_TX;
 501         chan->tx_win = L2CAP_DEFAULT_TX_WINDOW;
 502         chan->tx_win_max = L2CAP_DEFAULT_TX_WINDOW;
 503         chan->remote_max_tx = chan->max_tx;
 504         chan->remote_tx_win = chan->tx_win;
 505         chan->ack_win = L2CAP_DEFAULT_TX_WINDOW;
 506         chan->sec_level = BT_SECURITY_LOW;
 507         chan->flush_to = L2CAP_DEFAULT_FLUSH_TO;
 508         chan->retrans_timeout = L2CAP_DEFAULT_RETRANS_TO;
 509         chan->monitor_timeout = L2CAP_DEFAULT_MONITOR_TO;
 510         chan->conf_state = 0;
 511
 512         set_bit(FLAG_FORCE_ACTIVE, &chan->flags);
 513 }
 514 EXPORT_SYMBOL_GPL(l2cap_chan_set_defaults);
 515
 516 static void l2cap_le_flowctl_init(struct l2cap_chan *chan)
 517 {
 518         chan->sdu = NULL;
 519         chan->sdu_last_frag = NULL;
 520         chan->sdu_len = 0;
 521         chan->tx_credits = 0;
 522         chan->rx_credits = le_max_credits;
 523         chan->mps = min_t(u16, chan->imtu, le_default_mps);
 524
 525         skb_queue_head_init(&chan->tx_q);
 526 }
 527
 528 void __l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
 529 {
 530         BT_DBG("conn %p, psm 0x%2.2x, dcid 0x%4.4x", conn,
 531                __le16_to_cpu(chan->psm), chan->dcid);
 532
 533         conn->disc_reason = HCI_ERROR_REMOTE_USER_TERM;
 534
 535         chan->conn = conn;
 536
 537         switch (chan->chan_type) {
 538         case L2CAP_CHAN_CONN_ORIENTED:
 539                 /* Alloc CID for connection-oriented socket */
 540                 chan->scid = l2cap_alloc_cid(conn);
 541                 if (conn->hcon->type == ACL_LINK)
 542                         chan->omtu = L2CAP_DEFAULT_MTU;
 543                 break;
 544
 545         case L2CAP_CHAN_CONN_LESS:
 546                 /* Connectionless socket */
 547                 chan->scid = L2CAP_CID_CONN_LESS;
 548                 chan->dcid = L2CAP_CID_CONN_LESS;
 549                 chan->omtu = L2CAP_DEFAULT_MTU;
 550                 break;
 551
 552         case L2CAP_CHAN_FIXED:
 553                 /* Caller will set CID and CID specific MTU values */
 554                 break;
 555
 556         default:
 557                 /* Raw socket can send/recv signalling messages only */
 558                 chan->scid = L2CAP_CID_SIGNALING;
 559                 chan->dcid = L2CAP_CID_SIGNALING;
 560                 chan->omtu = L2CAP_DEFAULT_MTU;
 561         }
 562
 563         chan->local_id          = L2CAP_BESTEFFORT_ID;
 564         chan->local_stype       = L2CAP_SERV_BESTEFFORT;
 565         chan->local_msdu        = L2CAP_DEFAULT_MAX_SDU_SIZE;
 566         chan->local_sdu_itime   = L2CAP_DEFAULT_SDU_ITIME;
 567         chan->local_acc_lat     = L2CAP_DEFAULT_ACC_LAT;
 568         chan->local_flush_to    = L2CAP_EFS_DEFAULT_FLUSH_TO;
 569
 570         l2cap_chan_hold(chan);
 571
 572         /* Only keep a reference for fixed channels if they requested it */
 573         if (chan->chan_type != L2CAP_CHAN_FIXED ||
 574             test_bit(FLAG_HOLD_HCI_CONN, &chan->flags))
 575                 hci_conn_hold(conn->hcon);
 576
 577         list_add(&chan->list, &conn->chan_l);
 578 }
 579
 580 void l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
 581 {
 582         mutex_lock(&conn->chan_lock);
 583         __l2cap_chan_add(conn, chan);
 584         mutex_unlock(&conn->chan_lock);
 585 }
 586
 587 void l2cap_chan_del(struct l2cap_chan *chan, int err)
 588 {
 589         struct l2cap_conn *conn = chan->conn;
 590
 591         __clear_chan_timer(chan);
 592
 593         BT_DBG("chan %p, conn %p, err %d, state %s", chan, conn, err,
 594                state_to_string(chan->state));
 595
 596         chan->ops->teardown(chan, err);
 597
 598         if (conn) {
 599                 struct amp_mgr *mgr = conn->hcon->amp_mgr;
 600                 /* Delete from channel list */
 601                 list_del(&chan->list);
 602
 603                 l2cap_chan_put(chan);
 604
 605                 chan->conn = NULL;
 606
 607                 /* Reference was only held for non-fixed channels or
 608                  * fixed channels that explicitly requested it using the
 609                  * FLAG_HOLD_HCI_CONN flag.
 610                  */
 611                 if (chan->chan_type != L2CAP_CHAN_FIXED ||
 612                     test_bit(FLAG_HOLD_HCI_CONN, &chan->flags))
 613                         hci_conn_drop(conn->hcon);
 614
 615                 if (mgr && mgr->bredr_chan == chan)
 616                         mgr->bredr_chan = NULL;
 617         }
 618
 619         if (chan->hs_hchan) {
 620                 struct hci_chan *hs_hchan = chan->hs_hchan;
 621
 622                 BT_DBG("chan %p disconnect hs_hchan %p", chan, hs_hchan);
 623                 amp_disconnect_logical_link(hs_hchan);
 624         }
 625
 626         if (test_bit(CONF_NOT_COMPLETE, &chan->conf_state))
 627                 return;
 628
 629         switch(chan->mode) {
 630         case L2CAP_MODE_BASIC:
 631                 break;
 632
 633         case L2CAP_MODE_LE_FLOWCTL:
 634                 skb_queue_purge(&chan->tx_q);
 635                 break;
 636
 637         case L2CAP_MODE_ERTM:
 638                 __clear_retrans_timer(chan);
 639                 __clear_monitor_timer(chan);
 640                 __clear_ack_timer(chan);
 641
 642                 skb_queue_purge(&chan->srej_q);
 643
 644                 l2cap_seq_list_free(&chan->srej_list);
 645                 l2cap_seq_list_free(&chan->retrans_list);
 646
 647                 /* fall through */
 648
 649         case L2CAP_MODE_STREAMING:
 650                 skb_queue_purge(&chan->tx_q);
 651                 break;
 652         }
 653
 654         return;
 655 }
 656 EXPORT_SYMBOL_GPL(l2cap_chan_del);
 657
 658 static void l2cap_conn_update_id_addr(struct work_struct *work)
 659 {
 660         struct l2cap_conn *conn = container_of(work, struct l2cap_conn,
 661                                                id_addr_update_work);
 662         struct hci_conn *hcon = conn->hcon;
 663         struct l2cap_chan *chan;
 664
 665         mutex_lock(&conn->chan_lock);
 666
 667         list_for_each_entry(chan, &conn->chan_l, list) {
 668                 l2cap_chan_lock(chan);
 669                 bacpy(&chan->dst, &hcon->dst);
 670                 chan->dst_type = bdaddr_dst_type(hcon);
 671                 l2cap_chan_unlock(chan);
 672         }
 673
 674         mutex_unlock(&conn->chan_lock);
 675 }
 676
 677 static void l2cap_chan_le_connect_reject(struct l2cap_chan *chan)
 678 {
 679         struct l2cap_conn *conn = chan->conn;
 680         struct l2cap_le_conn_rsp rsp;
 681         u16 result;
 682
 683         if (test_bit(FLAG_DEFER_SETUP, &chan->flags))
 684                 result = L2CAP_CR_AUTHORIZATION;
 685         else
 686                 result = L2CAP_CR_BAD_PSM;
 687
 688         l2cap_state_change(chan, BT_DISCONN);
 689
 690         rsp.dcid    = cpu_to_le16(chan->scid);
 691         rsp.mtu     = cpu_to_le16(chan->imtu);
 692         rsp.mps     = cpu_to_le16(chan->mps);
 693         rsp.credits = cpu_to_le16(chan->rx_credits);
 694         rsp.result  = cpu_to_le16(result);
 695
 696         l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_RSP, sizeof(rsp),
 697                        &rsp);
 698 }
 699
 700 static void l2cap_chan_connect_reject(struct l2cap_chan *chan)
 701 {
 702         struct l2cap_conn *conn = chan->conn;
 703         struct l2cap_conn_rsp rsp;
 704         u16 result;
 705
 706         if (test_bit(FLAG_DEFER_SETUP, &chan->flags))
 707                 result = L2CAP_CR_SEC_BLOCK;
 708         else
 709                 result = L2CAP_CR_BAD_PSM;
 710
 711         l2cap_state_change(chan, BT_DISCONN);
 712
 713         rsp.scid   = cpu_to_le16(chan->dcid);
 714         rsp.dcid   = cpu_to_le16(chan->scid);
 715         rsp.result = cpu_to_le16(result);
 716         rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
 717
 718         l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP, sizeof(rsp), &rsp);
 719 }
 720
 721 void l2cap_chan_close(struct l2cap_chan *chan, int reason)
 722 {
 723         struct l2cap_conn *conn = chan->conn;
 724
 725         BT_DBG("chan %p state %s", chan, state_to_string(chan->state));
 726
 727         switch (chan->state) {
 728         case BT_LISTEN:
 729                 chan->ops->teardown(chan, 0);
 730                 break;
 731
 732         case BT_CONNECTED:
 733         case BT_CONFIG:
 734                 if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED) {
 735                         __set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
 736                         l2cap_send_disconn_req(chan, reason);
 737                 } else
 738                         l2cap_chan_del(chan, reason);
 739                 break;
 740
 741         case BT_CONNECT2:
 742                 if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED) {
 743                         if (conn->hcon->type == ACL_LINK)
 744                                 l2cap_chan_connect_reject(chan);
 745                         else if (conn->hcon->type == LE_LINK)
 746                                 l2cap_chan_le_connect_reject(chan);
 747                 }
 748
 749                 l2cap_chan_del(chan, reason);
 750                 break;
 751
 752         case BT_CONNECT:
 753         case BT_DISCONN:
 754                 l2cap_chan_del(chan, reason);
 755                 break;
 756
 757         default:
 758                 chan->ops->teardown(chan, 0);
 759                 break;
 760         }
 761 }
 762 EXPORT_SYMBOL(l2cap_chan_close);
 763
 764 static inline u8 l2cap_get_auth_type(struct l2cap_chan *chan)
 765 {
 766         switch (chan->chan_type) {
 767         case L2CAP_CHAN_RAW:
 768                 switch (chan->sec_level) {
 769                 case BT_SECURITY_HIGH:
 770                 case BT_SECURITY_FIPS:
 771                         return HCI_AT_DEDICATED_BONDING_MITM;
 772                 case BT_SECURITY_MEDIUM:
 773                         return HCI_AT_DEDICATED_BONDING;
 774                 default:
 775                         return HCI_AT_NO_BONDING;
 776                 }
 777                 break;
 778         case L2CAP_CHAN_CONN_LESS:
 779                 if (chan->psm == cpu_to_le16(L2CAP_PSM_3DSP)) {
 780                         if (chan->sec_level == BT_SECURITY_LOW)
 781                                 chan->sec_level = BT_SECURITY_SDP;
 782                 }
 783                 if (chan->sec_level == BT_SECURITY_HIGH ||
 784                     chan->sec_level == BT_SECURITY_FIPS)
 785                         return HCI_AT_NO_BONDING_MITM;
 786                 else
 787                         return HCI_AT_NO_BONDING;
 788                 break;
 789         case L2CAP_CHAN_CONN_ORIENTED:
 790                 if (chan->psm == cpu_to_le16(L2CAP_PSM_SDP)) {
 791                         if (chan->sec_level == BT_SECURITY_LOW)
 792                                 chan->sec_level = BT_SECURITY_SDP;
 793
 794                         if (chan->sec_level == BT_SECURITY_HIGH ||
 795                             chan->sec_level == BT_SECURITY_FIPS)
 796                                 return HCI_AT_NO_BONDING_MITM;
 797                         else
 798                                 return HCI_AT_NO_BONDING;
 799                 }
 800                 /* fall through */
 801         default:
 802                 switch (chan->sec_level) {
 803                 case BT_SECURITY_HIGH:
 804                 case BT_SECURITY_FIPS:
 805                         return HCI_AT_GENERAL_BONDING_MITM;
 806                 case BT_SECURITY_MEDIUM:
 807                         return HCI_AT_GENERAL_BONDING;
 808                 default:
 809                         return HCI_AT_NO_BONDING;
 810                 }
 811                 break;
 812         }
 813 }
 814
 815 /* Service level security */
 816 int l2cap_chan_check_security(struct l2cap_chan *chan, bool initiator)
 817 {
 818         struct l2cap_conn *conn = chan->conn;
 819         __u8 auth_type;
 820
 821         if (conn->hcon->type == LE_LINK)
 822                 return smp_conn_security(conn->hcon, chan->sec_level);
 823
 824         auth_type = l2cap_get_auth_type(chan);
 825
 826         return hci_conn_security(conn->hcon, chan->sec_level, auth_type,
 827                                  initiator);
 828 }
 829
 830 static u8 l2cap_get_ident(struct l2cap_conn *conn)
 831 {
 832         u8 id;
 833
 834         /* Get next available identificator.
 835          *    1 - 128 are used by kernel.
 836          *  129 - 199 are reserved.
 837          *  200 - 254 are used by utilities like l2ping, etc.
 838          */
 839
 840         mutex_lock(&conn->ident_lock);
 841
 842         if (++conn->tx_ident > 128)
 843                 conn->tx_ident = 1;
 844
 845         id = conn->tx_ident;
 846
 847         mutex_unlock(&conn->ident_lock);
 848
 849         return id;
 850 }
 851
 852 static void l2cap_send_cmd(struct l2cap_conn *conn, u8 ident, u8 code, u16 len,
 853                            void *data)
 854 {
 855         struct sk_buff *skb = l2cap_build_cmd(conn, code, ident, len, data);
 856         u8 flags;
 857
 858         BT_DBG("code 0x%2.2x", code);
 859
 860         if (!skb)
 861                 return;
 862
 863         /* Use NO_FLUSH if supported or we have an LE link (which does
 864          * not support auto-flushing packets) */
 865         if (lmp_no_flush_capable(conn->hcon->hdev) ||
 866             conn->hcon->type == LE_LINK)
 867                 flags = ACL_START_NO_FLUSH;
 868         else
 869                 flags = ACL_START;
 870
 871         bt_cb(skb)->force_active = BT_POWER_FORCE_ACTIVE_ON;
 872         skb->priority = HCI_PRIO_MAX;
 873
 874         hci_send_acl(conn->hchan, skb, flags);
 875 }
 876
 877 static bool __chan_is_moving(struct l2cap_chan *chan)
 878 {
 879         return chan->move_state != L2CAP_MOVE_STABLE &&
 880                chan->move_state != L2CAP_MOVE_WAIT_PREPARE;
 881 }
 882
 883 static void l2cap_do_send(struct l2cap_chan *chan, struct sk_buff *skb)
 884 {
 885         struct hci_conn *hcon = chan->conn->hcon;
 886         u16 flags;
 887
 888         BT_DBG("chan %p, skb %p len %d priority %u", chan, skb, skb->len,
 889                skb->priority);
 890
 891         if (chan->hs_hcon && !__chan_is_moving(chan)) {
 892                 if (chan->hs_hchan)
 893                         hci_send_acl(chan->hs_hchan, skb, ACL_COMPLETE);
 894                 else
 895                         kfree_skb(skb);
 896
 897                 return;
 898         }
 899
 900         /* Use NO_FLUSH for LE links (where this is the only option) or
 901          * if the BR/EDR link supports it and flushing has not been
 902          * explicitly requested (through FLAG_FLUSHABLE).
 903          */
 904         if (hcon->type == LE_LINK ||
 905             (!test_bit(FLAG_FLUSHABLE, &chan->flags) &&
 906              lmp_no_flush_capable(hcon->hdev)))
 907                 flags = ACL_START_NO_FLUSH;
 908         else
 909                 flags = ACL_START;
 910
 911         bt_cb(skb)->force_active = test_bit(FLAG_FORCE_ACTIVE, &chan->flags);
 912         hci_send_acl(chan->conn->hchan, skb, flags);
 913 }
 914
 915 static void __unpack_enhanced_control(u16 enh, struct l2cap_ctrl *control)
 916 {
 917         control->reqseq = (enh & L2CAP_CTRL_REQSEQ) >> L2CAP_CTRL_REQSEQ_SHIFT;
 918         control->final = (enh & L2CAP_CTRL_FINAL) >> L2CAP_CTRL_FINAL_SHIFT;
 919
 920         if (enh & L2CAP_CTRL_FRAME_TYPE) {
 921                 /* S-Frame */
 922                 control->sframe = 1;
 923                 control->poll = (enh & L2CAP_CTRL_POLL) >> L2CAP_CTRL_POLL_SHIFT;
 924                 control->super = (enh & L2CAP_CTRL_SUPERVISE) >> L2CAP_CTRL_SUPER_SHIFT;
 925
 926                 control->sar = 0;
 927                 control->txseq = 0;
 928         } else {
 929                 /* I-Frame */
 930                 control->sframe = 0;
 931                 control->sar = (enh & L2CAP_CTRL_SAR) >> L2CAP_CTRL_SAR_SHIFT;
 932                 control->txseq = (enh & L2CAP_CTRL_TXSEQ) >> L2CAP_CTRL_TXSEQ_SHIFT;
 933
 934                 control->poll = 0;
 935                 control->super = 0;
 936         }
 937 }
 938
 939 static void __unpack_extended_control(u32 ext, struct l2cap_ctrl *control)
 940 {
 941         control->reqseq = (ext & L2CAP_EXT_CTRL_REQSEQ) >> L2CAP_EXT_CTRL_REQSEQ_SHIFT;
 942         control->final = (ext & L2CAP_EXT_CTRL_FINAL) >> L2CAP_EXT_CTRL_FINAL_SHIFT;
 943
 944         if (ext & L2CAP_EXT_CTRL_FRAME_TYPE) {
 945                 /* S-Frame */
 946                 control->sframe = 1;
 947                 control->poll = (ext & L2CAP_EXT_CTRL_POLL) >> L2CAP_EXT_CTRL_POLL_SHIFT;
 948                 control->super = (ext & L2CAP_EXT_CTRL_SUPERVISE) >> L2CAP_EXT_CTRL_SUPER_SHIFT;
 949
 950                 control->sar = 0;
 951                 control->txseq = 0;
 952         } else {
 953                 /* I-Frame */
 954                 control->sframe = 0;
 955                 control->sar = (ext & L2CAP_EXT_CTRL_SAR) >> L2CAP_EXT_CTRL_SAR_SHIFT;
 956                 control->txseq = (ext & L2CAP_EXT_CTRL_TXSEQ) >> L2CAP_EXT_CTRL_TXSEQ_SHIFT;
 957
 958                 control->poll = 0;
 959                 control->super = 0;
 960         }
 961 }
 962
 963 static inline void __unpack_control(struct l2cap_chan *chan,
 964                                     struct sk_buff *skb)
 965 {
 966         if (test_bit(FLAG_EXT_CTRL, &chan->flags)) {
 967                 __unpack_extended_control(get_unaligned_le32(skb->data),
 968                                           &bt_cb(skb)->l2cap);
 969                 skb_pull(skb, L2CAP_EXT_CTRL_SIZE);
 970         } else {
 971                 __unpack_enhanced_control(get_unaligned_le16(skb->data),
 972                                           &bt_cb(skb)->l2cap);
 973                 skb_pull(skb, L2CAP_ENH_CTRL_SIZE);
 974         }
 975 }
 976
 977 static u32 __pack_extended_control(struct l2cap_ctrl *control)
 978 {
 979         u32 packed;
 980
 981         packed = control->reqseq << L2CAP_EXT_CTRL_REQSEQ_SHIFT;
 982         packed |= control->final << L2CAP_EXT_CTRL_FINAL_SHIFT;
 983
 984         if (control->sframe) {
 985                 packed |= control->poll << L2CAP_EXT_CTRL_POLL_SHIFT;
 986                 packed |= control->super << L2CAP_EXT_CTRL_SUPER_SHIFT;
 987                 packed |= L2CAP_EXT_CTRL_FRAME_TYPE;
 988         } else {
 989                 packed |= control->sar << L2CAP_EXT_CTRL_SAR_SHIFT;
 990                 packed |= control->txseq << L2CAP_EXT_CTRL_TXSEQ_SHIFT;
 991         }
 992
 993         return packed;
 994 }
 995
 996 static u16 __pack_enhanced_control(struct l2cap_ctrl *control)
 997 {
 998         u16 packed;
 999
1000         packed = control->reqseq << L2CAP_CTRL_REQSEQ_SHIFT;
1001         packed |= control->final << L2CAP_CTRL_FINAL_SHIFT;
1002
1003         if (control->sframe) {
1004                 packed |= control->poll << L2CAP_CTRL_POLL_SHIFT;
1005                 packed |= control->super << L2CAP_CTRL_SUPER_SHIFT;
1006                 packed |= L2CAP_CTRL_FRAME_TYPE;
1007         } else {
1008                 packed |= control->sar << L2CAP_CTRL_SAR_SHIFT;
1009                 packed |= control->txseq << L2CAP_CTRL_TXSEQ_SHIFT;
1010         }
1011
1012         return packed;
1013 }
1014
1015 static inline void __pack_control(struct l2cap_chan *chan,
1016                                   struct l2cap_ctrl *control,
1017                                   struct sk_buff *skb)
1018 {
1019         if (test_bit(FLAG_EXT_CTRL, &chan->flags)) {
1020                 put_unaligned_le32(__pack_extended_control(control),
1021                                    skb->data + L2CAP_HDR_SIZE);
1022         } else {
1023                 put_unaligned_le16(__pack_enhanced_control(control),
1024                                    skb->data + L2CAP_HDR_SIZE);
1025         }
1026 }
1027
1028 static inline unsigned int __ertm_hdr_size(struct l2cap_chan *chan)
1029 {
1030         if (test_bit(FLAG_EXT_CTRL, &chan->flags))
1031                 return L2CAP_EXT_HDR_SIZE;
1032         else
1033                 return L2CAP_ENH_HDR_SIZE;
1034 }
1035
1036 static struct sk_buff *l2cap_create_sframe_pdu(struct l2cap_chan *chan,
1037                                                u32 control)
1038 {
1039         struct sk_buff *skb;
1040         struct l2cap_hdr *lh;
1041         int hlen = __ertm_hdr_size(chan);
1042
1043         if (chan->fcs == L2CAP_FCS_CRC16)
1044                 hlen += L2CAP_FCS_SIZE;
1045
1046         skb = bt_skb_alloc(hlen, GFP_KERNEL);
1047
1048         if (!skb)
1049                 return ERR_PTR(-ENOMEM);
1050
1051         lh = skb_put(skb, L2CAP_HDR_SIZE);
1052         lh->len = cpu_to_le16(hlen - L2CAP_HDR_SIZE);
1053         lh->cid = cpu_to_le16(chan->dcid);
1054
1055         if (test_bit(FLAG_EXT_CTRL, &chan->flags))
1056                 put_unaligned_le32(control, skb_put(skb, L2CAP_EXT_CTRL_SIZE));
1057         else
1058                 put_unaligned_le16(control, skb_put(skb, L2CAP_ENH_CTRL_SIZE));
1059
1060         if (chan->fcs == L2CAP_FCS_CRC16) {
1061                 u16 fcs = crc16(0, (u8 *)skb->data, skb->len);
1062                 put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE));
1063         }
1064
1065         skb->priority = HCI_PRIO_MAX;
1066         return skb;
1067 }
1068
1069 static void l2cap_send_sframe(struct l2cap_chan *chan,
1070                               struct l2cap_ctrl *control)
1071 {
1072         struct sk_buff *skb;
1073         u32 control_field;
1074
1075         BT_DBG("chan %p, control %p", chan, control);
1076
1077         if (!control->sframe)
1078                 return;
1079
1080         if (__chan_is_moving(chan))
1081                 return;
1082
1083         if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state) &&
1084             !control->poll)
1085                 control->final = 1;
1086
1087         if (control->super == L2CAP_SUPER_RR)
1088                 clear_bit(CONN_RNR_SENT, &chan->conn_state);
1089         else if (control->super == L2CAP_SUPER_RNR)
1090                 set_bit(CONN_RNR_SENT, &chan->conn_state);
1091
1092         if (control->super != L2CAP_SUPER_SREJ) {
1093                 chan->last_acked_seq = control->reqseq;
1094                 __clear_ack_timer(chan);
1095         }
1096
1097         BT_DBG("reqseq %d, final %d, poll %d, super %d", control->reqseq,
1098                control->final, control->poll, control->super);
1099
1100         if (test_bit(FLAG_EXT_CTRL, &chan->flags))
1101                 control_field = __pack_extended_control(control);
1102         else
1103                 control_field = __pack_enhanced_control(control);
1104
1105         skb = l2cap_create_sframe_pdu(chan, control_field);
1106         if (!IS_ERR(skb))
1107                 l2cap_do_send(chan, skb);
1108 }
1109
1110 static void l2cap_send_rr_or_rnr(struct l2cap_chan *chan, bool poll)
1111 {
1112         struct l2cap_ctrl control;
1113
1114         BT_DBG("chan %p, poll %d", chan, poll);
1115
1116         memset(&control, 0, sizeof(control));
1117         control.sframe = 1;
1118         control.poll = poll;
1119
1120         if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state))
1121                 control.super = L2CAP_SUPER_RNR;
1122         else
1123                 control.super = L2CAP_SUPER_RR;
1124
1125         control.reqseq = chan->buffer_seq;
1126         l2cap_send_sframe(chan, &control);
1127 }
1128
1129 static inline int __l2cap_no_conn_pending(struct l2cap_chan *chan)
1130 {
1131         if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED)
1132                 return true;
1133
1134         return !test_bit(CONF_CONNECT_PEND, &chan->conf_state);
1135 }
1136
1137 static bool __amp_capable(struct l2cap_chan *chan)
1138 {
1139         struct l2cap_conn *conn = chan->conn;
1140         struct hci_dev *hdev;
1141         bool amp_available = false;
1142
1143         if (!(conn->local_fixed_chan & L2CAP_FC_A2MP))
1144                 return false;
1145
1146         if (!(conn->remote_fixed_chan & L2CAP_FC_A2MP))
1147                 return false;
1148
1149         read_lock(&hci_dev_list_lock);
1150         list_for_each_entry(hdev, &hci_dev_list, list) {
1151                 if (hdev->amp_type != AMP_TYPE_BREDR &&
1152                     test_bit(HCI_UP, &hdev->flags)) {
1153                         amp_available = true;
1154                         break;
1155                 }
1156         }
1157         read_unlock(&hci_dev_list_lock);
1158
1159         if (chan->chan_policy == BT_CHANNEL_POLICY_AMP_PREFERRED)
1160                 return amp_available;
1161
1162         return false;
1163 }
1164
1165 static bool l2cap_check_efs(struct l2cap_chan *chan)
1166 {
1167         /* Check EFS parameters */
1168         return true;
1169 }
1170
1171 void l2cap_send_conn_req(struct l2cap_chan *chan)
1172 {
1173         struct l2cap_conn *conn = chan->conn;
1174         struct l2cap_conn_req req;
1175
1176         req.scid = cpu_to_le16(chan->scid);
1177         req.psm  = chan->psm;
1178
1179         chan->ident = l2cap_get_ident(conn);
1180
1181         set_bit(CONF_CONNECT_PEND, &chan->conf_state);
1182
1183         l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_REQ, sizeof(req), &req);
1184 }
1185
1186 static void l2cap_send_create_chan_req(struct l2cap_chan *chan, u8 amp_id)
1187 {
1188         struct l2cap_create_chan_req req;
1189         req.scid = cpu_to_le16(chan->scid);
1190         req.psm  = chan->psm;
1191         req.amp_id = amp_id;
1192
1193         chan->ident = l2cap_get_ident(chan->conn);
1194
1195         l2cap_send_cmd(chan->conn, chan->ident, L2CAP_CREATE_CHAN_REQ,
1196                        sizeof(req), &req);
1197 }
1198
1199 static void l2cap_move_setup(struct l2cap_chan *chan)
1200 {
1201         struct sk_buff *skb;
1202
1203         BT_DBG("chan %p", chan);
1204
1205         if (chan->mode != L2CAP_MODE_ERTM)
1206                 return;
1207
1208         __clear_retrans_timer(chan);
1209         __clear_monitor_timer(chan);
1210         __clear_ack_timer(chan);
1211
1212         chan->retry_count = 0;
1213         skb_queue_walk(&chan->tx_q, skb) {
1214                 if (bt_cb(skb)->l2cap.retries)
1215                         bt_cb(skb)->l2cap.retries = 1;
1216                 else
1217                         break;
1218         }
1219
1220         chan->expected_tx_seq = chan->buffer_seq;
1221
1222         clear_bit(CONN_REJ_ACT, &chan->conn_state);
1223         clear_bit(CONN_SREJ_ACT, &chan->conn_state);
1224         l2cap_seq_list_clear(&chan->retrans_list);
1225         l2cap_seq_list_clear(&chan->srej_list);
1226         skb_queue_purge(&chan->srej_q);
1227
1228         chan->tx_state = L2CAP_TX_STATE_XMIT;
1229         chan->rx_state = L2CAP_RX_STATE_MOVE;
1230
1231         set_bit(CONN_REMOTE_BUSY, &chan->conn_state);
1232 }
1233
1234 static void l2cap_move_done(struct l2cap_chan *chan)
1235 {
1236         u8 move_role = chan->move_role;
1237         BT_DBG("chan %p", chan);
1238
1239         chan->move_state = L2CAP_MOVE_STABLE;
1240         chan->move_role = L2CAP_MOVE_ROLE_NONE;
1241
1242         if (chan->mode != L2CAP_MODE_ERTM)
1243                 return;
1244
1245         switch (move_role) {
1246         case L2CAP_MOVE_ROLE_INITIATOR:
1247                 l2cap_tx(chan, NULL, NULL, L2CAP_EV_EXPLICIT_POLL);
1248                 chan->rx_state = L2CAP_RX_STATE_WAIT_F;
1249                 break;
1250         case L2CAP_MOVE_ROLE_RESPONDER:
1251                 chan->rx_state = L2CAP_RX_STATE_WAIT_P;
1252                 break;
1253         }
1254 }
1255
1256 static void l2cap_chan_ready(struct l2cap_chan *chan)
1257 {
1258         /* The channel may have already been flagged as connected in
1259          * case of receiving data before the L2CAP info req/rsp
1260          * procedure is complete.
1261          */
1262         if (chan->state == BT_CONNECTED)
1263                 return;
1264
1265         /* This clears all conf flags, including CONF_NOT_COMPLETE */
1266         chan->conf_state = 0;
1267         __clear_chan_timer(chan);
1268
1269         if (chan->mode == L2CAP_MODE_LE_FLOWCTL && !chan->tx_credits)
1270                 chan->ops->suspend(chan);
1271
1272         chan->state = BT_CONNECTED;
1273
1274         chan->ops->ready(chan);
1275 }
1276
1277 static void l2cap_le_connect(struct l2cap_chan *chan)
1278 {
1279         struct l2cap_conn *conn = chan->conn;
1280         struct l2cap_le_conn_req req;
1281
1282         if (test_and_set_bit(FLAG_LE_CONN_REQ_SENT, &chan->flags))
1283                 return;
1284
1285         req.psm     = chan->psm;
1286         req.scid    = cpu_to_le16(chan->scid);
1287         req.mtu     = cpu_to_le16(chan->imtu);
1288         req.mps     = cpu_to_le16(chan->mps);
1289         req.credits = cpu_to_le16(chan->rx_credits);
1290
1291         chan->ident = l2cap_get_ident(conn);
1292
1293         l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_REQ,
1294                        sizeof(req), &req);
1295 }
1296
1297 static void l2cap_le_start(struct l2cap_chan *chan)
1298 {
1299         struct l2cap_conn *conn = chan->conn;
1300
1301         if (!smp_conn_security(conn->hcon, chan->sec_level))
1302                 return;
1303
1304         if (!chan->psm) {
1305                 l2cap_chan_ready(chan);
1306                 return;
1307         }
1308
1309         if (chan->state == BT_CONNECT)
1310                 l2cap_le_connect(chan);
1311 }
1312
1313 static void l2cap_start_connection(struct l2cap_chan *chan)
1314 {
1315         if (__amp_capable(chan)) {
1316                 BT_DBG("chan %p AMP capable: discover AMPs", chan);
1317                 a2mp_discover_amp(chan);
1318         } else if (chan->conn->hcon->type == LE_LINK) {
1319                 l2cap_le_start(chan);
1320         } else {
1321                 l2cap_send_conn_req(chan);
1322         }
1323 }
1324
1325 static void l2cap_request_info(struct l2cap_conn *conn)
1326 {
1327         struct l2cap_info_req req;
1328
1329         if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT)
1330                 return;
1331
1332         req.type = cpu_to_le16(L2CAP_IT_FEAT_MASK);
1333
1334         conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_SENT;
1335         conn->info_ident = l2cap_get_ident(conn);
1336
1337         schedule_delayed_work(&conn->info_timer, L2CAP_INFO_TIMEOUT);
1338
1339         l2cap_send_cmd(conn, conn->info_ident, L2CAP_INFO_REQ,
1340                        sizeof(req), &req);
1341 }
1342
1343 static void l2cap_do_start(struct l2cap_chan *chan)
1344 {
1345         struct l2cap_conn *conn = chan->conn;
1346
1347         if (conn->hcon->type == LE_LINK) {
1348                 l2cap_le_start(chan);
1349                 return;
1350         }
1351
1352         if (!(conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT)) {
1353                 l2cap_request_info(conn);
1354                 return;
1355         }
1356
1357         if (!(conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE))
1358                 return;
1359
1360         if (l2cap_chan_check_security(chan, true) &&
1361             __l2cap_no_conn_pending(chan))
1362                 l2cap_start_connection(chan);
1363 }
1364
1365 static inline int l2cap_mode_supported(__u8 mode, __u32 feat_mask)
1366 {
1367         u32 local_feat_mask = l2cap_feat_mask;
1368         if (!disable_ertm)
1369                 local_feat_mask |= L2CAP_FEAT_ERTM | L2CAP_FEAT_STREAMING;
1370
1371         switch (mode) {
1372         case L2CAP_MODE_ERTM:
1373                 return L2CAP_FEAT_ERTM & feat_mask & local_feat_mask;
1374         case L2CAP_MODE_STREAMING:
1375                 return L2CAP_FEAT_STREAMING & feat_mask & local_feat_mask;
1376         default:
1377                 return 0x00;
1378         }
1379 }
1380
1381 static void l2cap_send_disconn_req(struct l2cap_chan *chan, int err)
1382 {
1383         struct l2cap_conn *conn = chan->conn;
1384         struct l2cap_disconn_req req;
1385
1386         if (!conn)
1387                 return;
1388
1389         if (chan->mode == L2CAP_MODE_ERTM && chan->state == BT_CONNECTED) {
1390                 __clear_retrans_timer(chan);
1391                 __clear_monitor_timer(chan);
1392                 __clear_ack_timer(chan);
1393         }
1394
1395         if (chan->scid == L2CAP_CID_A2MP) {
1396                 l2cap_state_change(chan, BT_DISCONN);
1397                 return;
1398         }
1399
1400         req.dcid = cpu_to_le16(chan->dcid);
1401         req.scid = cpu_to_le16(chan->scid);
1402         l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_DISCONN_REQ,
1403                        sizeof(req), &req);
1404
1405         l2cap_state_change_and_error(chan, BT_DISCONN, err);
1406 }
1407
1408 /* ---- L2CAP connections ---- */
1409 static void l2cap_conn_start(struct l2cap_conn *conn)
1410 {
1411         struct l2cap_chan *chan, *tmp;
1412
1413         BT_DBG("conn %p", conn);
1414
1415         mutex_lock(&conn->chan_lock);
1416
1417         list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) {
1418                 l2cap_chan_lock(chan);
1419
1420                 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
1421                         l2cap_chan_ready(chan);
1422                         l2cap_chan_unlock(chan);
1423                         continue;
1424                 }
1425
1426                 if (chan->state == BT_CONNECT) {
1427                         if (!l2cap_chan_check_security(chan, true) ||
1428                             !__l2cap_no_conn_pending(chan)) {
1429                                 l2cap_chan_unlock(chan);
1430                                 continue;
1431                         }
1432
1433                         if (!l2cap_mode_supported(chan->mode, conn->feat_mask)
1434                             && test_bit(CONF_STATE2_DEVICE,
1435                                         &chan->conf_state)) {
1436                                 l2cap_chan_close(chan, ECONNRESET);
1437                                 l2cap_chan_unlock(chan);
1438                                 continue;
1439                         }
1440
1441                         l2cap_start_connection(chan);
1442
1443                 } else if (chan->state == BT_CONNECT2) {
1444                         struct l2cap_conn_rsp rsp;
1445                         char buf[128];
1446                         rsp.scid = cpu_to_le16(chan->dcid);
1447                         rsp.dcid = cpu_to_le16(chan->scid);
1448
1449                         if (l2cap_chan_check_security(chan, false)) {
1450                                 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
1451                                         rsp.result = cpu_to_le16(L2CAP_CR_PEND);
1452                                         rsp.status = cpu_to_le16(L2CAP_CS_AUTHOR_PEND);
1453                                         chan->ops->defer(chan);
1454
1455                                 } else {
1456                                         l2cap_state_change(chan, BT_CONFIG);
1457                                         rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS);
1458                                         rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
1459                                 }
1460                         } else {
1461                                 rsp.result = cpu_to_le16(L2CAP_CR_PEND);
1462                                 rsp.status = cpu_to_le16(L2CAP_CS_AUTHEN_PEND);
1463                         }
1464
1465                         l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP,
1466                                        sizeof(rsp), &rsp);
1467
1468                         if (test_bit(CONF_REQ_SENT, &chan->conf_state) ||
1469                             rsp.result != L2CAP_CR_SUCCESS) {
1470                                 l2cap_chan_unlock(chan);
1471                                 continue;
1472                         }
1473
1474                         set_bit(CONF_REQ_SENT, &chan->conf_state);
1475                         l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
1476                                        l2cap_build_conf_req(chan, buf), buf);
1477                         chan->num_conf_req++;
1478                 }
1479
1480                 l2cap_chan_unlock(chan);
1481         }
1482
1483         mutex_unlock(&conn->chan_lock);
1484 }
1485
1486 static void l2cap_le_conn_ready(struct l2cap_conn *conn)
1487 {
1488         struct hci_conn *hcon = conn->hcon;
1489         struct hci_dev *hdev = hcon->hdev;
1490
1491         BT_DBG("%s conn %p", hdev->name, conn);
1492
1493         /* For outgoing pairing which doesn't necessarily have an
1494          * associated socket (e.g. mgmt_pair_device).
1495          */
1496         if (hcon->out)
1497                 smp_conn_security(hcon, hcon->pending_sec_level);
1498
1499         /* For LE slave connections, make sure the connection interval
1500          * is in the range of the minium and maximum interval that has
1501          * been configured for this connection. If not, then trigger
1502          * the connection update procedure.
1503          */
1504         if (hcon->role == HCI_ROLE_SLAVE &&
1505             (hcon->le_conn_interval < hcon->le_conn_min_interval ||
1506              hcon->le_conn_interval > hcon->le_conn_max_interval)) {
1507                 struct l2cap_conn_param_update_req req;
1508
1509                 req.min = cpu_to_le16(hcon->le_conn_min_interval);
1510                 req.max = cpu_to_le16(hcon->le_conn_max_interval);
1511                 req.latency = cpu_to_le16(hcon->le_conn_latency);
1512                 req.to_multiplier = cpu_to_le16(hcon->le_supv_timeout);
1513
1514                 l2cap_send_cmd(conn, l2cap_get_ident(conn),
1515                                L2CAP_CONN_PARAM_UPDATE_REQ, sizeof(req), &req);
1516         }
1517 }
1518
1519 static void l2cap_conn_ready(struct l2cap_conn *conn)
1520 {
1521         struct l2cap_chan *chan;
1522         struct hci_conn *hcon = conn->hcon;
1523
1524         BT_DBG("conn %p", conn);
1525
1526         if (hcon->type == ACL_LINK)
1527                 l2cap_request_info(conn);
1528
1529         mutex_lock(&conn->chan_lock);
1530
1531         list_for_each_entry(chan, &conn->chan_l, list) {
1532
1533                 l2cap_chan_lock(chan);
1534
1535                 if (chan->scid == L2CAP_CID_A2MP) {
1536                         l2cap_chan_unlock(chan);
1537                         continue;
1538                 }
1539
1540                 if (hcon->type == LE_LINK) {
1541                         l2cap_le_start(chan);
1542                 } else if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
1543                         if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE)
1544                                 l2cap_chan_ready(chan);
1545                 } else if (chan->state == BT_CONNECT) {
1546                         l2cap_do_start(chan);
1547                 }
1548
1549                 l2cap_chan_unlock(chan);
1550         }
1551
1552         mutex_unlock(&conn->chan_lock);
1553
1554         if (hcon->type == LE_LINK)
1555                 l2cap_le_conn_ready(conn);
1556
1557         queue_work(hcon->hdev->workqueue, &conn->pending_rx_work);
1558 }
1559
1560 /* Notify sockets that we cannot guaranty reliability anymore */
1561 static void l2cap_conn_unreliable(struct l2cap_conn *conn, int err)
1562 {
1563         struct l2cap_chan *chan;
1564
1565         BT_DBG("conn %p", conn);
1566
1567         mutex_lock(&conn->chan_lock);
1568
1569         list_for_each_entry(chan, &conn->chan_l, list) {
1570                 if (test_bit(FLAG_FORCE_RELIABLE, &chan->flags))
1571                         l2cap_chan_set_err(chan, err);
1572         }
1573
1574         mutex_unlock(&conn->chan_lock);
1575 }
1576
1577 static void l2cap_info_timeout(struct work_struct *work)
1578 {
1579         struct l2cap_conn *conn = container_of(work, struct l2cap_conn,
1580                                                info_timer.work);
1581
1582         conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
1583         conn->info_ident = 0;
1584
1585         l2cap_conn_start(conn);
1586 }
1587
1588 /*
1589  * l2cap_user
1590  * External modules can register l2cap_user objects on l2cap_conn. The ->probe
1591  * callback is called during registration. The ->remove callback is called
1592  * during unregistration.
1593  * An l2cap_user object can either be explicitly unregistered or when the
1594  * underlying l2cap_conn object is deleted. This guarantees that l2cap->hcon,
1595  * l2cap->hchan, .. are valid as long as the remove callback hasn't been called.
1596  * External modules must own a reference to the l2cap_conn object if they intend
1597  * to call l2cap_unregister_user(). The l2cap_conn object might get destroyed at
1598  * any time if they don't.
1599  */
1600
1601 int l2cap_register_user(struct l2cap_conn *conn, struct l2cap_user *user)
1602 {
1603         struct hci_dev *hdev = conn->hcon->hdev;
1604         int ret;
1605
1606         /* We need to check whether l2cap_conn is registered. If it is not, we
1607          * must not register the l2cap_user. l2cap_conn_del() is unregisters
1608          * l2cap_conn objects, but doesn't provide its own locking. Instead, it
1609          * relies on the parent hci_conn object to be locked. This itself relies
1610          * on the hci_dev object to be locked. So we must lock the hci device
1611          * here, too. */
1612
1613         hci_dev_lock(hdev);
1614
1615         if (!list_empty(&user->list)) {
1616                 ret = -EINVAL;
1617                 goto out_unlock;
1618         }
1619
1620         /* conn->hchan is NULL after l2cap_conn_del() was called */
1621         if (!conn->hchan) {
1622                 ret = -ENODEV;
1623                 goto out_unlock;
1624         }
1625
1626         ret = user->probe(conn, user);
1627         if (ret)
1628                 goto out_unlock;
1629
1630         list_add(&user->list, &conn->users);
1631         ret = 0;
1632
1633 out_unlock:
1634         hci_dev_unlock(hdev);
1635         return ret;
1636 }
1637 EXPORT_SYMBOL(l2cap_register_user);
1638
1639 void l2cap_unregister_user(struct l2cap_conn *conn, struct l2cap_user *user)
1640 {
1641         struct hci_dev *hdev = conn->hcon->hdev;
1642
1643         hci_dev_lock(hdev);
1644
1645         if (list_empty(&user->list))
1646                 goto out_unlock;
1647
1648         list_del_init(&user->list);
1649         user->remove(conn, user);
1650
1651 out_unlock:
1652         hci_dev_unlock(hdev);
1653 }
1654 EXPORT_SYMBOL(l2cap_unregister_user);
1655
1656 static void l2cap_unregister_all_users(struct l2cap_conn *conn)
1657 {
1658         struct l2cap_user *user;
1659
1660         while (!list_empty(&conn->users)) {
1661                 user = list_first_entry(&conn->users, struct l2cap_user, list);
1662                 list_del_init(&user->list);
1663                 user->remove(conn, user);
1664         }
1665 }
1666
1667 static void l2cap_conn_del(struct hci_conn *hcon, int err)
1668 {
1669         struct l2cap_conn *conn = hcon->l2cap_data;
1670         struct l2cap_chan *chan, *l;
1671
1672         if (!conn)
1673                 return;
1674
1675         BT_DBG("hcon %p conn %p, err %d", hcon, conn, err);
1676
1677         kfree_skb(conn->rx_skb);
1678
1679         skb_queue_purge(&conn->pending_rx);
1680
1681         /* We can not call flush_work(&conn->pending_rx_work) here since we
1682          * might block if we are running on a worker from the same workqueue
1683          * pending_rx_work is waiting on.
1684          */
1685         if (work_pending(&conn->pending_rx_work))
1686                 cancel_work_sync(&conn->pending_rx_work);
1687
1688         if (work_pending(&conn->id_addr_update_work))
1689                 cancel_work_sync(&conn->id_addr_update_work);
1690
1691         l2cap_unregister_all_users(conn);
1692
1693         /* Force the connection to be immediately dropped */
1694         hcon->disc_timeout = 0;
1695
1696         mutex_lock(&conn->chan_lock);
1697
1698         /* Kill channels */
1699         list_for_each_entry_safe(chan, l, &conn->chan_l, list) {
1700                 l2cap_chan_hold(chan);
1701                 l2cap_chan_lock(chan);
1702
1703                 l2cap_chan_del(chan, err);
1704
1705                 l2cap_chan_unlock(chan);
1706
1707                 chan->ops->close(chan);
1708                 l2cap_chan_put(chan);
1709         }
1710
1711         mutex_unlock(&conn->chan_lock);
1712
1713         hci_chan_del(conn->hchan);
1714
1715         if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT)
1716                 cancel_delayed_work_sync(&conn->info_timer);
1717
1718         hcon->l2cap_data = NULL;
1719         conn->hchan = NULL;
1720         l2cap_conn_put(conn);
1721 }
1722
1723 static void l2cap_conn_free(struct kref *ref)
1724 {
1725         struct l2cap_conn *conn = container_of(ref, struct l2cap_conn, ref);
1726
1727         hci_conn_put(conn->hcon);
1728         kfree(conn);
1729 }
1730
1731 struct l2cap_conn *l2cap_conn_get(struct l2cap_conn *conn)
1732 {
1733         kref_get(&conn->ref);
1734         return conn;
1735 }
1736 EXPORT_SYMBOL(l2cap_conn_get);
1737
1738 void l2cap_conn_put(struct l2cap_conn *conn)
1739 {
1740         kref_put(&conn->ref, l2cap_conn_free);
1741 }
1742 EXPORT_SYMBOL(l2cap_conn_put);
1743
1744 /* ---- Socket interface ---- */
1745
1746 /* Find socket with psm and source / destination bdaddr.
1747  * Returns closest match.
1748  */
1749 static struct l2cap_chan *l2cap_global_chan_by_psm(int state, __le16 psm,
1750                                                    bdaddr_t *src,
1751                                                    bdaddr_t *dst,
1752                                                    u8 link_type)
1753 {
1754         struct l2cap_chan *c, *c1 = NULL;
1755
1756         read_lock(&chan_list_lock);
1757
1758         list_for_each_entry(c, &chan_list, global_l) {
1759                 if (state && c->state != state)
1760                         continue;
1761
1762                 if (link_type == ACL_LINK && c->src_type != BDADDR_BREDR)
1763                         continue;
1764
1765                 if (link_type == LE_LINK && c->src_type == BDADDR_BREDR)
1766                         continue;
1767
1768                 if (c->psm == psm) {
1769                         int src_match, dst_match;
1770                         int src_any, dst_any;
1771
1772                         /* Exact match. */
1773                         src_match = !bacmp(&c->src, src);
1774                         dst_match = !bacmp(&c->dst, dst);
1775                         if (src_match && dst_match) {
1776                                 l2cap_chan_hold(c);
1777                                 read_unlock(&chan_list_lock);
1778                                 return c;
1779                         }
1780
1781                         /* Closest match */
1782                         src_any = !bacmp(&c->src, BDADDR_ANY);
1783                         dst_any = !bacmp(&c->dst, BDADDR_ANY);
1784                         if ((src_match && dst_any) || (src_any && dst_match) ||
1785                             (src_any && dst_any))
1786                                 c1 = c;
1787                 }
1788         }
1789
1790         if (c1)
1791                 l2cap_chan_hold(c1);
1792
1793         read_unlock(&chan_list_lock);
1794
1795         return c1;
1796 }
1797
1798 static void l2cap_monitor_timeout(struct work_struct *work)
1799 {
1800         struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
1801                                                monitor_timer.work);
1802
1803         BT_DBG("chan %p", chan);
1804
1805         l2cap_chan_lock(chan);
1806
1807         if (!chan->conn) {
1808                 l2cap_chan_unlock(chan);
1809                 l2cap_chan_put(chan);
1810                 return;
1811         }
1812
1813         l2cap_tx(chan, NULL, NULL, L2CAP_EV_MONITOR_TO);
1814
1815         l2cap_chan_unlock(chan);
1816         l2cap_chan_put(chan);
1817 }
1818
1819 static void l2cap_retrans_timeout(struct work_struct *work)
1820 {
1821         struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
1822                                                retrans_timer.work);
1823
1824         BT_DBG("chan %p", chan);
1825
1826         l2cap_chan_lock(chan);
1827
1828         if (!chan->conn) {
1829                 l2cap_chan_unlock(chan);
1830                 l2cap_chan_put(chan);
1831                 return;
1832         }
1833
1834         l2cap_tx(chan, NULL, NULL, L2CAP_EV_RETRANS_TO);
1835         l2cap_chan_unlock(chan);
1836         l2cap_chan_put(chan);
1837 }
1838
1839 static void l2cap_streaming_send(struct l2cap_chan *chan,
1840                                  struct sk_buff_head *skbs)
1841 {
1842         struct sk_buff *skb;
1843         struct l2cap_ctrl *control;
1844
1845         BT_DBG("chan %p, skbs %p", chan, skbs);
1846
1847         if (__chan_is_moving(chan))
1848                 return;
1849
1850         skb_queue_splice_tail_init(skbs, &chan->tx_q);
1851
1852         while (!skb_queue_empty(&chan->tx_q)) {
1853
1854                 skb = skb_dequeue(&chan->tx_q);
1855
1856                 bt_cb(skb)->l2cap.retries = 1;
1857                 control = &bt_cb(skb)->l2cap;
1858
1859                 control->reqseq = 0;
1860                 control->txseq = chan->next_tx_seq;
1861
1862                 __pack_control(chan, control, skb);
1863
1864                 if (chan->fcs == L2CAP_FCS_CRC16) {
1865                         u16 fcs = crc16(0, (u8 *) skb->data, skb->len);
1866                         put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE));
1867                 }
1868
1869                 l2cap_do_send(chan, skb);
1870
1871                 BT_DBG("Sent txseq %u", control->txseq);
1872
1873                 chan->next_tx_seq = __next_seq(chan, chan->next_tx_seq);
1874                 chan->frames_sent++;
1875         }
1876 }
1877
1878 static int l2cap_ertm_send(struct l2cap_chan *chan)
1879 {
1880         struct sk_buff *skb, *tx_skb;
1881         struct l2cap_ctrl *control;
1882         int sent = 0;
1883
1884         BT_DBG("chan %p", chan);
1885
1886         if (chan->state != BT_CONNECTED)
1887                 return -ENOTCONN;
1888
1889         if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state))
1890                 return 0;
1891
1892         if (__chan_is_moving(chan))
1893                 return 0;
1894
1895         while (chan->tx_send_head &&
1896                chan->unacked_frames < chan->remote_tx_win &&
1897                chan->tx_state == L2CAP_TX_STATE_XMIT) {
1898
1899                 skb = chan->tx_send_head;
1900
1901                 bt_cb(skb)->l2cap.retries = 1;
1902                 control = &bt_cb(skb)->l2cap;
1903
1904                 if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state))
1905                         control->final = 1;
1906
1907                 control->reqseq = chan->buffer_seq;
1908                 chan->last_acked_seq = chan->buffer_seq;
1909                 control->txseq = chan->next_tx_seq;
1910
1911                 __pack_control(chan, control, skb);
1912
1913                 if (chan->fcs == L2CAP_FCS_CRC16) {
1914                         u16 fcs = crc16(0, (u8 *) skb->data, skb->len);
1915                         put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE));
1916                 }
1917
1918                 /* Clone after data has been modified. Data is assumed to be
1919                    read-only (for locking purposes) on cloned sk_buffs.
1920                  */
1921                 tx_skb = skb_clone(skb, GFP_KERNEL);
1922
1923                 if (!tx_skb)
1924                         break;
1925
1926                 __set_retrans_timer(chan);
1927
1928                 chan->next_tx_seq = __next_seq(chan, chan->next_tx_seq);
1929                 chan->unacked_frames++;
1930                 chan->frames_sent++;
1931                 sent++;
1932
1933                 if (skb_queue_is_last(&chan->tx_q, skb))
1934                         chan->tx_send_head = NULL;
1935                 else
1936                         chan->tx_send_head = skb_queue_next(&chan->tx_q, skb);
1937
1938                 l2cap_do_send(chan, tx_skb);
1939                 BT_DBG("Sent txseq %u", control->txseq);
1940         }
1941
1942         BT_DBG("Sent %d, %u unacked, %u in ERTM queue", sent,
1943                chan->unacked_frames, skb_queue_len(&chan->tx_q));
1944
1945         return sent;
1946 }
1947
1948 static void l2cap_ertm_resend(struct l2cap_chan *chan)
1949 {
1950         struct l2cap_ctrl control;
1951         struct sk_buff *skb;
1952         struct sk_buff *tx_skb;
1953         u16 seq;
1954
1955         BT_DBG("chan %p", chan);
1956
1957         if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state))
1958                 return;
1959
1960         if (__chan_is_moving(chan))
1961                 return;
1962
1963         while (chan->retrans_list.head != L2CAP_SEQ_LIST_CLEAR) {
1964                 seq = l2cap_seq_list_pop(&chan->retrans_list);
1965
1966                 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, seq);
1967                 if (!skb) {
1968                         BT_DBG("Error: Can't retransmit seq %d, frame missing",
1969                                seq);
1970                         continue;
1971                 }
1972
1973                 bt_cb(skb)->l2cap.retries++;
1974                 control = bt_cb(skb)->l2cap;
1975
1976                 if (chan->max_tx != 0 &&
1977                     bt_cb(skb)->l2cap.retries > chan->max_tx) {
1978                         BT_DBG("Retry limit exceeded (%d)", chan->max_tx);
1979                         l2cap_send_disconn_req(chan, ECONNRESET);
1980                         l2cap_seq_list_clear(&chan->retrans_list);
1981                         break;
1982                 }
1983
1984                 control.reqseq = chan->buffer_seq;
1985                 if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state))
1986                         control.final = 1;
1987                 else
1988                         control.final = 0;
1989
1990                 if (skb_cloned(skb)) {
1991                         /* Cloned sk_buffs are read-only, so we need a
1992                          * writeable copy
1993                          */
1994                         tx_skb = skb_copy(skb, GFP_KERNEL);
1995                 } else {
1996                         tx_skb = skb_clone(skb, GFP_KERNEL);
1997                 }
1998
1999                 if (!tx_skb) {
2000                         l2cap_seq_list_clear(&chan->retrans_list);
2001                         break;
2002                 }
2003
2004                 /* Update skb contents */
2005                 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) {
2006                         put_unaligned_le32(__pack_extended_control(&control),
2007                                            tx_skb->data + L2CAP_HDR_SIZE);
2008                 } else {
2009                         put_unaligned_le16(__pack_enhanced_control(&control),
2010                                            tx_skb->data + L2CAP_HDR_SIZE);
2011                 }
2012
2013                 /* Update FCS */
2014                 if (chan->fcs == L2CAP_FCS_CRC16) {
2015                         u16 fcs = crc16(0, (u8 *) tx_skb->data,
2016                                         tx_skb->len - L2CAP_FCS_SIZE);
2017                         put_unaligned_le16(fcs, skb_tail_pointer(tx_skb) -
2018                                                 L2CAP_FCS_SIZE);
2019                 }
2020
2021                 l2cap_do_send(chan, tx_skb);
2022
2023                 BT_DBG("Resent txseq %d", control.txseq);
2024
2025                 chan->last_acked_seq = chan->buffer_seq;
2026         }
2027 }
2028
2029 static void l2cap_retransmit(struct l2cap_chan *chan,
2030                              struct l2cap_ctrl *control)
2031 {
2032         BT_DBG("chan %p, control %p", chan, control);
2033
2034         l2cap_seq_list_append(&chan->retrans_list, control->reqseq);
2035         l2cap_ertm_resend(chan);
2036 }
2037
2038 static void l2cap_retransmit_all(struct l2cap_chan *chan,
2039                                  struct l2cap_ctrl *control)
2040 {
2041         struct sk_buff *skb;
2042
2043         BT_DBG("chan %p, control %p", chan, control);
2044
2045         if (control->poll)
2046                 set_bit(CONN_SEND_FBIT, &chan->conn_state);
2047
2048         l2cap_seq_list_clear(&chan->retrans_list);
2049
2050         if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state))
2051                 return;
2052
2053         if (chan->unacked_frames) {
2054                 skb_queue_walk(&chan->tx_q, skb) {
2055                         if (bt_cb(skb)->l2cap.txseq == control->reqseq ||
2056                             skb == chan->tx_send_head)
2057                                 break;
2058                 }
2059
2060                 skb_queue_walk_from(&chan->tx_q, skb) {
2061                         if (skb == chan->tx_send_head)
2062                                 break;
2063
2064                         l2cap_seq_list_append(&chan->retrans_list,
2065                                               bt_cb(skb)->l2cap.txseq);
2066                 }
2067
2068                 l2cap_ertm_resend(chan);
2069         }
2070 }
2071
2072 static void l2cap_send_ack(struct l2cap_chan *chan)
2073 {
2074         struct l2cap_ctrl control;
2075         u16 frames_to_ack = __seq_offset(chan, chan->buffer_seq,
2076                                          chan->last_acked_seq);
2077         int threshold;
2078
2079         BT_DBG("chan %p last_acked_seq %d buffer_seq %d",
2080                chan, chan->last_acked_seq, chan->buffer_seq);
2081
2082         memset(&control, 0, sizeof(control));
2083         control.sframe = 1;
2084
2085         if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state) &&
2086             chan->rx_state == L2CAP_RX_STATE_RECV) {
2087                 __clear_ack_timer(chan);
2088                 control.super = L2CAP_SUPER_RNR;
2089                 control.reqseq = chan->buffer_seq;
2090                 l2cap_send_sframe(chan, &control);
2091         } else {
2092                 if (!test_bit(CONN_REMOTE_BUSY, &chan->conn_state)) {
2093                         l2cap_ertm_send(chan);
2094                         /* If any i-frames were sent, they included an ack */
2095                         if (chan->buffer_seq == chan->last_acked_seq)
2096                                 frames_to_ack = 0;
2097                 }
2098
2099                 /* Ack now if the window is 3/4ths full.
2100                  * Calculate without mul or div
2101                  */
2102                 threshold = chan->ack_win;
2103                 threshold += threshold << 1;
2104                 threshold >>= 2;
2105
2106                 BT_DBG("frames_to_ack %u, threshold %d", frames_to_ack,
2107                        threshold);
2108
2109                 if (frames_to_ack >= threshold) {
2110                         __clear_ack_timer(chan);
2111                         control.super = L2CAP_SUPER_RR;
2112                         control.reqseq = chan->buffer_seq;
2113                         l2cap_send_sframe(chan, &control);
2114                         frames_to_ack = 0;
2115                 }
2116
2117                 if (frames_to_ack)
2118                         __set_ack_timer(chan);
2119         }
2120 }
2121
2122 static inline int l2cap_skbuff_fromiovec(struct l2cap_chan *chan,
2123                                          struct msghdr *msg, int len,
2124                                          int count, struct sk_buff *skb)
2125 {
2126         struct l2cap_conn *conn = chan->conn;
2127         struct sk_buff **frag;
2128         int sent = 0;
2129
2130         if (!copy_from_iter_full(skb_put(skb, count), count, &msg->msg_iter))
2131                 return -EFAULT;
2132
2133         sent += count;
2134         len  -= count;
2135
2136         /* Continuation fragments (no L2CAP header) */
2137         frag = &skb_shinfo(skb)->frag_list;
2138         while (len) {
2139                 struct sk_buff *tmp;
2140
2141                 count = min_t(unsigned int, conn->mtu, len);
2142
2143                 tmp = chan->ops->alloc_skb(chan, 0, count,
2144                                            msg->msg_flags & MSG_DONTWAIT);
2145                 if (IS_ERR(tmp))
2146                         return PTR_ERR(tmp);
2147
2148                 *frag = tmp;
2149
2150                 if (!copy_from_iter_full(skb_put(*frag, count), count,
2151                                    &msg->msg_iter))
2152                         return -EFAULT;
2153
2154                 sent += count;
2155                 len  -= count;
2156
2157                 skb->len += (*frag)->len;
2158                 skb->data_len += (*frag)->len;
2159
2160                 frag = &(*frag)->next;
2161         }
2162
2163         return sent;
2164 }
2165
2166 static struct sk_buff *l2cap_create_connless_pdu(struct l2cap_chan *chan,
2167                                                  struct msghdr *msg, size_t len)
2168 {
2169         struct l2cap_conn *conn = chan->conn;
2170         struct sk_buff *skb;
2171         int err, count, hlen = L2CAP_HDR_SIZE + L2CAP_PSMLEN_SIZE;
2172         struct l2cap_hdr *lh;
2173
2174         BT_DBG("chan %p psm 0x%2.2x len %zu", chan,
2175                __le16_to_cpu(chan->psm), len);
2176
2177         count = min_t(unsigned int, (conn->mtu - hlen), len);
2178
2179         skb = chan->ops->alloc_skb(chan, hlen, count,
2180                                    msg->msg_flags & MSG_DONTWAIT);
2181         if (IS_ERR(skb))
2182                 return skb;
2183
2184         /* Create L2CAP header */
2185         lh = skb_put(skb, L2CAP_HDR_SIZE);
2186         lh->cid = cpu_to_le16(chan->dcid);
2187         lh->len = cpu_to_le16(len + L2CAP_PSMLEN_SIZE);
2188         put_unaligned(chan->psm, (__le16 *) skb_put(skb, L2CAP_PSMLEN_SIZE));
2189
2190         err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
2191         if (unlikely(err < 0)) {
2192                 kfree_skb(skb);
2193                 return ERR_PTR(err);
2194         }
2195         return skb;
2196 }
2197
2198 static struct sk_buff *l2cap_create_basic_pdu(struct l2cap_chan *chan,
2199                                               struct msghdr *msg, size_t len)
2200 {
2201         struct l2cap_conn *conn = chan->conn;
2202         struct sk_buff *skb;
2203         int err, count;
2204         struct l2cap_hdr *lh;
2205
2206         BT_DBG("chan %p len %zu", chan, len);
2207
2208         count = min_t(unsigned int, (conn->mtu - L2CAP_HDR_SIZE), len);
2209
2210         skb = chan->ops->alloc_skb(chan, L2CAP_HDR_SIZE, count,
2211                                    msg->msg_flags & MSG_DONTWAIT);
2212         if (IS_ERR(skb))
2213                 return skb;
2214
2215         /* Create L2CAP header */
2216         lh = skb_put(skb, L2CAP_HDR_SIZE);
2217         lh->cid = cpu_to_le16(chan->dcid);
2218         lh->len = cpu_to_le16(len);
2219
2220         err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
2221         if (unlikely(err < 0)) {
2222                 kfree_skb(skb);
2223                 return ERR_PTR(err);
2224         }
2225         return skb;
2226 }
2227
2228 static struct sk_buff *l2cap_create_iframe_pdu(struct l2cap_chan *chan,
2229                                                struct msghdr *msg, size_t len,
2230                                                u16 sdulen)
2231 {
2232         struct l2cap_conn *conn = chan->conn;
2233         struct sk_buff *skb;
2234         int err, count, hlen;
2235         struct l2cap_hdr *lh;
2236
2237         BT_DBG("chan %p len %zu", chan, len);
2238
2239         if (!conn)
2240                 return ERR_PTR(-ENOTCONN);
2241
2242         hlen = __ertm_hdr_size(chan);
2243
2244         if (sdulen)
2245                 hlen += L2CAP_SDULEN_SIZE;
2246
2247         if (chan->fcs == L2CAP_FCS_CRC16)
2248                 hlen += L2CAP_FCS_SIZE;
2249
2250         count = min_t(unsigned int, (conn->mtu - hlen), len);
2251
2252         skb = chan->ops->alloc_skb(chan, hlen, count,
2253                                    msg->msg_flags & MSG_DONTWAIT);
2254         if (IS_ERR(skb))
2255                 return skb;
2256
2257         /* Create L2CAP header */
2258         lh = skb_put(skb, L2CAP_HDR_SIZE);
2259         lh->cid = cpu_to_le16(chan->dcid);
2260         lh->len = cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE));
2261
2262         /* Control header is populated later */
2263         if (test_bit(FLAG_EXT_CTRL, &chan->flags))
2264                 put_unaligned_le32(0, skb_put(skb, L2CAP_EXT_CTRL_SIZE));
2265         else
2266                 put_unaligned_le16(0, skb_put(skb, L2CAP_ENH_CTRL_SIZE));
2267
2268         if (sdulen)
2269                 put_unaligned_le16(sdulen, skb_put(skb, L2CAP_SDULEN_SIZE));
2270
2271         err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
2272         if (unlikely(err < 0)) {
2273                 kfree_skb(skb);
2274                 return ERR_PTR(err);
2275         }
2276
2277         bt_cb(skb)->l2cap.fcs = chan->fcs;
2278         bt_cb(skb)->l2cap.retries = 0;
2279         return skb;
2280 }
2281
2282 static int l2cap_segment_sdu(struct l2cap_chan *chan,
2283                              struct sk_buff_head *seg_queue,
2284                              struct msghdr *msg, size_t len)
2285 {
2286         struct sk_buff *skb;
2287         u16 sdu_len;
2288         size_t pdu_len;
2289         u8 sar;
2290
2291         BT_DBG("chan %p, msg %p, len %zu", chan, msg, len);
2292
2293         /* It is critical that ERTM PDUs fit in a single HCI fragment,
2294          * so fragmented skbs are not used.  The HCI layer's handling
2295          * of fragmented skbs is not compatible with ERTM's queueing.
2296          */
2297
2298         /* PDU size is derived from the HCI MTU */
2299         pdu_len = chan->conn->mtu;
2300
2301         /* Constrain PDU size for BR/EDR connections */
2302         if (!chan->hs_hcon)
2303                 pdu_len = min_t(size_t, pdu_len, L2CAP_BREDR_MAX_PAYLOAD);
2304
2305         /* Adjust for largest possible L2CAP overhead. */
2306         if (chan->fcs)
2307                 pdu_len -= L2CAP_FCS_SIZE;
2308
2309         pdu_len -= __ertm_hdr_size(chan);
2310
2311         /* Remote device may have requested smaller PDUs */
2312         pdu_len = min_t(size_t, pdu_len, chan->remote_mps);
2313
2314         if (len <= pdu_len) {
2315                 sar = L2CAP_SAR_UNSEGMENTED;
2316                 sdu_len = 0;
2317                 pdu_len = len;
2318         } else {
2319                 sar = L2CAP_SAR_START;
2320                 sdu_len = len;
2321         }
2322
2323         while (len > 0) {
2324                 skb = l2cap_create_iframe_pdu(chan, msg, pdu_len, sdu_len);
2325
2326                 if (IS_ERR(skb)) {
2327                         __skb_queue_purge(seg_queue);
2328                         return PTR_ERR(skb);
2329                 }
2330
2331                 bt_cb(skb)->l2cap.sar = sar;
2332                 __skb_queue_tail(seg_queue, skb);
2333
2334                 len -= pdu_len;
2335                 if (sdu_len)
2336                         sdu_len = 0;
2337
2338                 if (len <= pdu_len) {
2339                         sar = L2CAP_SAR_END;
2340                         pdu_len = len;
2341                 } else {
2342                         sar = L2CAP_SAR_CONTINUE;
2343                 }
2344         }
2345
2346         return 0;
2347 }
2348
2349 static struct sk_buff *l2cap_create_le_flowctl_pdu(struct l2cap_chan *chan,
2350                                                    struct msghdr *msg,
2351                                                    size_t len, u16 sdulen)
2352 {
2353         struct l2cap_conn *conn = chan->conn;
2354         struct sk_buff *skb;
2355         int err, count, hlen;
2356         struct l2cap_hdr *lh;
2357
2358         BT_DBG("chan %p len %zu", chan, len);
2359
2360         if (!conn)
2361                 return ERR_PTR(-ENOTCONN);
2362
2363         hlen = L2CAP_HDR_SIZE;
2364
2365         if (sdulen)
2366                 hlen += L2CAP_SDULEN_SIZE;
2367
2368         count = min_t(unsigned int, (conn->mtu - hlen), len);
2369
2370         skb = chan->ops->alloc_skb(chan, hlen, count,
2371                                    msg->msg_flags & MSG_DONTWAIT);
2372         if (IS_ERR(skb))
2373                 return skb;
2374
2375         /* Create L2CAP header */
2376         lh = skb_put(skb, L2CAP_HDR_SIZE);
2377         lh->cid = cpu_to_le16(chan->dcid);
2378         lh->len = cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE));
2379
2380         if (sdulen)
2381                 put_unaligned_le16(sdulen, skb_put(skb, L2CAP_SDULEN_SIZE));
2382
2383         err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
2384         if (unlikely(err < 0)) {
2385                 kfree_skb(skb);
2386                 return ERR_PTR(err);
2387         }
2388
2389         return skb;
2390 }
2391
2392 static int l2cap_segment_le_sdu(struct l2cap_chan *chan,
2393                                 struct sk_buff_head *seg_queue,
2394                                 struct msghdr *msg, size_t len)
2395 {
2396         struct sk_buff *skb;
2397         size_t pdu_len;
2398         u16 sdu_len;
2399
2400         BT_DBG("chan %p, msg %p, len %zu", chan, msg, len);
2401
2402         sdu_len = len;
2403         pdu_len = chan->remote_mps - L2CAP_SDULEN_SIZE;
2404
2405         while (len > 0) {
2406                 if (len <= pdu_len)
2407                         pdu_len = len;
2408
2409                 skb = l2cap_create_le_flowctl_pdu(chan, msg, pdu_len, sdu_len);
2410                 if (IS_ERR(skb)) {
2411                         __skb_queue_purge(seg_queue);
2412                         return PTR_ERR(skb);
2413                 }
2414
2415                 __skb_queue_tail(seg_queue, skb);
2416
2417                 len -= pdu_len;
2418
2419                 if (sdu_len) {
2420                         sdu_len = 0;
2421                         pdu_len += L2CAP_SDULEN_SIZE;
2422                 }
2423         }
2424
2425         return 0;
2426 }
2427
2428 static void l2cap_le_flowctl_send(struct l2cap_chan *chan)
2429 {
2430         int sent = 0;
2431
2432         BT_DBG("chan %p", chan);
2433
2434         while (chan->tx_credits && !skb_queue_empty(&chan->tx_q)) {
2435                 l2cap_do_send(chan, skb_dequeue(&chan->tx_q));
2436                 chan->tx_credits--;
2437                 sent++;
2438         }
2439
2440         BT_DBG("Sent %d credits %u queued %u", sent, chan->tx_credits,
2441                skb_queue_len(&chan->tx_q));
2442 }
2443
2444 int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len)
2445 {
2446         struct sk_buff *skb;
2447         int err;
2448         struct sk_buff_head seg_queue;
2449
2450         if (!chan->conn)
2451                 return -ENOTCONN;
2452
2453         /* Connectionless channel */
2454         if (chan->chan_type == L2CAP_CHAN_CONN_LESS) {
2455                 skb = l2cap_create_connless_pdu(chan, msg, len);
2456                 if (IS_ERR(skb))
2457                         return PTR_ERR(skb);
2458
2459                 /* Channel lock is released before requesting new skb and then
2460                  * reacquired thus we need to recheck channel state.
2461                  */
2462                 if (chan->state != BT_CONNECTED) {
2463                         kfree_skb(skb);
2464                         return -ENOTCONN;
2465                 }
2466
2467                 l2cap_do_send(chan, skb);
2468                 return len;
2469         }
2470
2471         switch (chan->mode) {
2472         case L2CAP_MODE_LE_FLOWCTL:
2473                 /* Check outgoing MTU */
2474                 if (len > chan->omtu)
2475                         return -EMSGSIZE;
2476
2477                 __skb_queue_head_init(&seg_queue);
2478
2479                 err = l2cap_segment_le_sdu(chan, &seg_queue, msg, len);
2480
2481                 if (chan->state != BT_CONNECTED) {
2482                         __skb_queue_purge(&seg_queue);
2483                         err = -ENOTCONN;
2484                 }
2485
2486                 if (err)
2487                         return err;
2488
2489                 skb_queue_splice_tail_init(&seg_queue, &chan->tx_q);
2490
2491                 l2cap_le_flowctl_send(chan);
2492
2493                 if (!chan->tx_credits)
2494                         chan->ops->suspend(chan);
2495
2496                 err = len;
2497
2498                 break;
2499
2500         case L2CAP_MODE_BASIC:
2501                 /* Check outgoing MTU */
2502                 if (len > chan->omtu)
2503                         return -EMSGSIZE;
2504
2505                 /* Create a basic PDU */
2506                 skb = l2cap_create_basic_pdu(chan, msg, len);
2507                 if (IS_ERR(skb))
2508                         return PTR_ERR(skb);
2509
2510                 /* Channel lock is released before requesting new skb and then
2511                  * reacquired thus we need to recheck channel state.
2512                  */
2513                 if (chan->state != BT_CONNECTED) {
2514                         kfree_skb(skb);
2515                         return -ENOTCONN;
2516                 }
2517
2518                 l2cap_do_send(chan, skb);
2519                 err = len;
2520                 break;
2521
2522         case L2CAP_MODE_ERTM:
2523         case L2CAP_MODE_STREAMING:
2524                 /* Check outgoing MTU */
2525                 if (len > chan->omtu) {
2526                         err = -EMSGSIZE;
2527                         break;
2528                 }
2529
2530                 __skb_queue_head_init(&seg_queue);
2531
2532                 /* Do segmentation before calling in to the state machine,
2533                  * since it's possible to block while waiting for memory
2534                  * allocation.
2535                  */
2536                 err = l2cap_segment_sdu(chan, &seg_queue, msg, len);
2537
2538                 /* The channel could have been closed while segmenting,
2539                  * check that it is still connected.
2540                  */
2541                 if (chan->state != BT_CONNECTED) {
2542                         __skb_queue_purge(&seg_queue);
2543                         err = -ENOTCONN;
2544                 }
2545
2546                 if (err)
2547                         break;
2548
2549                 if (chan->mode == L2CAP_MODE_ERTM)
2550                         l2cap_tx(chan, NULL, &seg_queue, L2CAP_EV_DATA_REQUEST);
2551                 else
2552                         l2cap_streaming_send(chan, &seg_queue);
2553
2554                 err = len;
2555
2556                 /* If the skbs were not queued for sending, they'll still be in
2557                  * seg_queue and need to be purged.
2558                  */
2559                 __skb_queue_purge(&seg_queue);
2560                 break;
2561
2562         default:
2563                 BT_DBG("bad state %1.1x", chan->mode);
2564                 err = -EBADFD;
2565         }
2566
2567         return err;
2568 }
2569 EXPORT_SYMBOL_GPL(l2cap_chan_send);
2570
2571 static void l2cap_send_srej(struct l2cap_chan *chan, u16 txseq)
2572 {
2573         struct l2cap_ctrl control;
2574         u16 seq;
2575
2576         BT_DBG("chan %p, txseq %u", chan, txseq);
2577
2578         memset(&control, 0, sizeof(control));
2579         control.sframe = 1;
2580         control.super = L2CAP_SUPER_SREJ;
2581
2582         for (seq = chan->expected_tx_seq; seq != txseq;
2583              seq = __next_seq(chan, seq)) {
2584                 if (!l2cap_ertm_seq_in_queue(&chan->srej_q, seq)) {
2585                         control.reqseq = seq;
2586                         l2cap_send_sframe(chan, &control);
2587                         l2cap_seq_list_append(&chan->srej_list, seq);
2588                 }
2589         }
2590
2591         chan->expected_tx_seq = __next_seq(chan, txseq);
2592 }
2593
2594 static void l2cap_send_srej_tail(struct l2cap_chan *chan)
2595 {
2596         struct l2cap_ctrl control;
2597
2598         BT_DBG("chan %p", chan);
2599
2600         if (chan->srej_list.tail == L2CAP_SEQ_LIST_CLEAR)
2601                 return;
2602
2603         memset(&control, 0, sizeof(control));
2604         control.sframe = 1;
2605         control.super = L2CAP_SUPER_SREJ;
2606         control.reqseq = chan->srej_list.tail;
2607         l2cap_send_sframe(chan, &control);
2608 }
2609
2610 static void l2cap_send_srej_list(struct l2cap_chan *chan, u16 txseq)
2611 {
2612         struct l2cap_ctrl control;
2613         u16 initial_head;
2614         u16 seq;
2615
2616         BT_DBG("chan %p, txseq %u", chan, txseq);
2617
2618         memset(&control, 0, sizeof(control));
2619         control.sframe = 1;
2620         control.super = L2CAP_SUPER_SREJ;
2621
2622         /* Capture initial list head to allow only one pass through the list. */
2623         initial_head = chan->srej_list.head;
2624
2625         do {
2626                 seq = l2cap_seq_list_pop(&chan->srej_list);
2627                 if (seq == txseq || seq == L2CAP_SEQ_LIST_CLEAR)
2628                         break;
2629
2630                 control.reqseq = seq;
2631                 l2cap_send_sframe(chan, &control);
2632                 l2cap_seq_list_append(&chan->srej_list, seq);
2633         } while (chan->srej_list.head != initial_head);
2634 }
2635
2636 static void l2cap_process_reqseq(struct l2cap_chan *chan, u16 reqseq)
2637 {
2638         struct sk_buff *acked_skb;
2639         u16 ackseq;
2640
2641         BT_DBG("chan %p, reqseq %u", chan, reqseq);
2642
2643         if (chan->unacked_frames == 0 || reqseq == chan->expected_ack_seq)
2644                 return;
2645
2646         BT_DBG("expected_ack_seq %u, unacked_frames %u",
2647                chan->expected_ack_seq, chan->unacked_frames);
2648
2649         for (ackseq = chan->expected_ack_seq; ackseq != reqseq;
2650              ackseq = __next_seq(chan, ackseq)) {
2651
2652                 acked_skb = l2cap_ertm_seq_in_queue(&chan->tx_q, ackseq);
2653                 if (acked_skb) {
2654                         skb_unlink(acked_skb, &chan->tx_q);
2655                         kfree_skb(acked_skb);
2656                         chan->unacked_frames--;
2657                 }
2658         }
2659
2660         chan->expected_ack_seq = reqseq;
2661
2662         if (chan->unacked_frames == 0)
2663                 __clear_retrans_timer(chan);
2664
2665         BT_DBG("unacked_frames %u", chan->unacked_frames);
2666 }
2667
2668 static void l2cap_abort_rx_srej_sent(struct l2cap_chan *chan)
2669 {
2670         BT_DBG("chan %p", chan);
2671
2672         chan->expected_tx_seq = chan->buffer_seq;
2673         l2cap_seq_list_clear(&chan->srej_list);
2674         skb_queue_purge(&chan->srej_q);
2675         chan->rx_state = L2CAP_RX_STATE_RECV;
2676 }
2677
2678 static void l2cap_tx_state_xmit(struct l2cap_chan *chan,
2679                                 struct l2cap_ctrl *control,
2680                                 struct sk_buff_head *skbs, u8 event)
2681 {
2682         BT_DBG("chan %p, control %p, skbs %p, event %d", chan, control, skbs,
2683                event);
2684
2685         switch (event) {
2686         case L2CAP_EV_DATA_REQUEST:
2687                 if (chan->tx_send_head == NULL)
2688                         chan->tx_send_head = skb_peek(skbs);
2689
2690                 skb_queue_splice_tail_init(skbs, &chan->tx_q);
2691                 l2cap_ertm_send(chan);
2692                 break;
2693         case L2CAP_EV_LOCAL_BUSY_DETECTED:
2694                 BT_DBG("Enter LOCAL_BUSY");
2695                 set_bit(CONN_LOCAL_BUSY, &chan->conn_state);
2696
2697                 if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) {
2698                         /* The SREJ_SENT state must be aborted if we are to
2699                          * enter the LOCAL_BUSY state.
2700                          */
2701                         l2cap_abort_rx_srej_sent(chan);
2702                 }
2703
2704                 l2cap_send_ack(chan);
2705
2706                 break;
2707         case L2CAP_EV_LOCAL_BUSY_CLEAR:
2708                 BT_DBG("Exit LOCAL_BUSY");
2709                 clear_bit(CONN_LOCAL_BUSY, &chan->conn_state);
2710
2711                 if (test_bit(CONN_RNR_SENT, &chan->conn_state)) {
2712                         struct l2cap_ctrl local_control;
2713
2714                         memset(&local_control, 0, sizeof(local_control));
2715                         local_control.sframe = 1;
2716                         local_control.super = L2CAP_SUPER_RR;
2717                         local_control.poll = 1;
2718                         local_control.reqseq = chan->buffer_seq;
2719                         l2cap_send_sframe(chan, &local_control);
2720
2721                         chan->retry_count = 1;
2722                         __set_monitor_timer(chan);
2723                         chan->tx_state = L2CAP_TX_STATE_WAIT_F;
2724                 }
2725                 break;
2726         case L2CAP_EV_RECV_REQSEQ_AND_FBIT:
2727                 l2cap_process_reqseq(chan, control->reqseq);
2728                 break;
2729         case L2CAP_EV_EXPLICIT_POLL:
2730                 l2cap_send_rr_or_rnr(chan, 1);
2731                 chan->retry_count = 1;
2732                 __set_monitor_timer(chan);
2733                 __clear_ack_timer(chan);
2734                 chan->tx_state = L2CAP_TX_STATE_WAIT_F;
2735                 break;
2736         case L2CAP_EV_RETRANS_TO:
2737                 l2cap_send_rr_or_rnr(chan, 1);
2738                 chan->retry_count = 1;
2739                 __set_monitor_timer(chan);
2740                 chan->tx_state = L2CAP_TX_STATE_WAIT_F;
2741                 break;
2742         case L2CAP_EV_RECV_FBIT:
2743                 /* Nothing to process */
2744                 break;
2745         default:
2746                 break;
2747         }
2748 }
2749
2750 static void l2cap_tx_state_wait_f(struct l2cap_chan *chan,
2751                                   struct l2cap_ctrl *control,
2752                                   struct sk_buff_head *skbs, u8 event)
2753 {
2754         BT_DBG("chan %p, control %p, skbs %p, event %d", chan, control, skbs,
2755                event);
2756
2757         switch (event) {
2758         case L2CAP_EV_DATA_REQUEST:
2759                 if (chan->tx_send_head == NULL)
2760                         chan->tx_send_head = skb_peek(skbs);
2761                 /* Queue data, but don't send. */
2762                 skb_queue_splice_tail_init(skbs, &chan->tx_q);
2763                 break;
2764         case L2CAP_EV_LOCAL_BUSY_DETECTED:
2765                 BT_DBG("Enter LOCAL_BUSY");
2766                 set_bit(CONN_LOCAL_BUSY, &chan->conn_state);
2767
2768                 if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) {
2769                         /* The SREJ_SENT state must be aborted if we are to
2770                          * enter the LOCAL_BUSY state.
2771                          */
2772                         l2cap_abort_rx_srej_sent(chan);
2773                 }
2774
2775                 l2cap_send_ack(chan);
2776
2777                 break;
2778         case L2CAP_EV_LOCAL_BUSY_CLEAR:
2779                 BT_DBG("Exit LOCAL_BUSY");
2780                 clear_bit(CONN_LOCAL_BUSY, &chan->conn_state);
2781
2782                 if (test_bit(CONN_RNR_SENT, &chan->conn_state)) {
2783                         struct l2cap_ctrl local_control;
2784                         memset(&local_control, 0, sizeof(local_control));
2785                         local_control.sframe = 1;
2786                         local_control.super = L2CAP_SUPER_RR;
2787                         local_control.poll = 1;
2788                         local_control.reqseq = chan->buffer_seq;
2789                         l2cap_send_sframe(chan, &local_control);
2790
2791                         chan->retry_count = 1;
2792                         __set_monitor_timer(chan);
2793                         chan->tx_state = L2CAP_TX_STATE_WAIT_F;
2794                 }
2795                 break;
2796         case L2CAP_EV_RECV_REQSEQ_AND_FBIT:
2797                 l2cap_process_reqseq(chan, control->reqseq);
2798
2799                 /* Fall through */
2800
2801         case L2CAP_EV_RECV_FBIT:
2802                 if (control && control->final) {
2803                         __clear_monitor_timer(chan);
2804                         if (chan->unacked_frames > 0)
2805                                 __set_retrans_timer(chan);
2806                         chan->retry_count = 0;
2807                         chan->tx_state = L2CAP_TX_STATE_XMIT;
2808                         BT_DBG("recv fbit tx_state 0x2.2%x", chan->tx_state);
2809                 }
2810                 break;
2811         case L2CAP_EV_EXPLICIT_POLL:
2812                 /* Ignore */
2813                 break;
2814         case L2CAP_EV_MONITOR_TO:
2815                 if (chan->max_tx == 0 || chan->retry_count < chan->max_tx) {
2816                         l2cap_send_rr_or_rnr(chan, 1);
2817                         __set_monitor_timer(chan);
2818                         chan->retry_count++;
2819                 } else {
2820                         l2cap_send_disconn_req(chan, ECONNABORTED);
2821                 }
2822                 break;
2823         default:
2824                 break;
2825         }
2826 }
2827
2828 static void l2cap_tx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
2829                      struct sk_buff_head *skbs, u8 event)
2830 {
2831         BT_DBG("chan %p, control %p, skbs %p, event %d, state %d",
2832                chan, control, skbs, event, chan->tx_state);
2833
2834         switch (chan->tx_state) {
2835         case L2CAP_TX_STATE_XMIT:
2836                 l2cap_tx_state_xmit(chan, control, skbs, event);
2837                 break;
2838         case L2CAP_TX_STATE_WAIT_F:
2839                 l2cap_tx_state_wait_f(chan, control, skbs, event);
2840                 break;
2841         default:
2842                 /* Ignore event */
2843                 break;
2844         }
2845 }
2846
2847 static void l2cap_pass_to_tx(struct l2cap_chan *chan,
2848                              struct l2cap_ctrl *control)
2849 {
2850         BT_DBG("chan %p, control %p", chan, control);
2851         l2cap_tx(chan, control, NULL, L2CAP_EV_RECV_REQSEQ_AND_FBIT);
2852 }
2853
2854 static void l2cap_pass_to_tx_fbit(struct l2cap_chan *chan,
2855                                   struct l2cap_ctrl *control)
2856 {
2857         BT_DBG("chan %p, control %p", chan, control);
2858         l2cap_tx(chan, control, NULL, L2CAP_EV_RECV_FBIT);
2859 }
2860
2861 /* Copy frame to all raw sockets on that connection */
2862 static void l2cap_raw_recv(struct l2cap_conn *conn, struct sk_buff *skb)
2863 {
2864         struct sk_buff *nskb;
2865         struct l2cap_chan *chan;
2866
2867         BT_DBG("conn %p", conn);
2868
2869         mutex_lock(&conn->chan_lock);
2870
2871         list_for_each_entry(chan, &conn->chan_l, list) {
2872                 if (chan->chan_type != L2CAP_CHAN_RAW)
2873                         continue;
2874
2875                 /* Don't send frame to the channel it came from */
2876                 if (bt_cb(skb)->l2cap.chan == chan)
2877                         continue;
2878
2879                 nskb = skb_clone(skb, GFP_KERNEL);
2880                 if (!nskb)
2881                         continue;
2882                 if (chan->ops->recv(chan, nskb))
2883                         kfree_skb(nskb);
2884         }
2885
2886         mutex_unlock(&conn->chan_lock);
2887 }
2888
2889 /* ---- L2CAP signalling commands ---- */
2890 static struct sk_buff *l2cap_build_cmd(struct l2cap_conn *conn, u8 code,
2891                                        u8 ident, u16 dlen, void *data)
2892 {
2893         struct sk_buff *skb, **frag;
2894         struct l2cap_cmd_hdr *cmd;
2895         struct l2cap_hdr *lh;
2896         int len, count;
2897
2898         BT_DBG("conn %p, code 0x%2.2x, ident 0x%2.2x, len %u",
2899                conn, code, ident, dlen);
2900
2901         if (conn->mtu < L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE)
2902                 return NULL;
2903
2904         len = L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE + dlen;
2905         count = min_t(unsigned int, conn->mtu, len);
2906
2907         skb = bt_skb_alloc(count, GFP_KERNEL);
2908         if (!skb)
2909                 return NULL;
2910
2911         lh = skb_put(skb, L2CAP_HDR_SIZE);
2912         lh->len = cpu_to_le16(L2CAP_CMD_HDR_SIZE + dlen);
2913
2914         if (conn->hcon->type == LE_LINK)
2915                 lh->cid = cpu_to_le16(L2CAP_CID_LE_SIGNALING);
2916         else
2917                 lh->cid = cpu_to_le16(L2CAP_CID_SIGNALING);
2918
2919         cmd = skb_put(skb, L2CAP_CMD_HDR_SIZE);
2920         cmd->code  = code;
2921         cmd->ident = ident;
2922         cmd->len   = cpu_to_le16(dlen);
2923
2924         if (dlen) {
2925                 count -= L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE;
2926                 skb_put_data(skb, data, count);
2927                 data += count;
2928         }
2929
2930         len -= skb->len;
2931
2932         /* Continuation fragments (no L2CAP header) */
2933         frag = &skb_shinfo(skb)->frag_list;
2934         while (len) {
2935                 count = min_t(unsigned int, conn->mtu, len);
2936
2937                 *frag = bt_skb_alloc(count, GFP_KERNEL);
2938                 if (!*frag)
2939                         goto fail;
2940
2941                 skb_put_data(*frag, data, count);
2942
2943                 len  -= count;
2944                 data += count;
2945
2946                 frag = &(*frag)->next;
2947         }
2948
2949         return skb;
2950
2951 fail:
2952         kfree_skb(skb);
2953         return NULL;
2954 }
2955
2956 static inline int l2cap_get_conf_opt(void **ptr, int *type, int *olen,
2957                                      unsigned long *val)
2958 {
2959         struct l2cap_conf_opt *opt = *ptr;
2960         int len;
2961
2962         len = L2CAP_CONF_OPT_SIZE + opt->len;
2963         *ptr += len;
2964
2965         *type = opt->type;
2966         *olen = opt->len;
2967
2968         switch (opt->len) {
2969         case 1:
2970                 *val = *((u8 *) opt->val);
2971                 break;
2972
2973         case 2:
2974                 *val = get_unaligned_le16(opt->val);
2975                 break;
2976
2977         case 4:
2978                 *val = get_unaligned_le32(opt->val);
2979                 break;
2980
2981         default:
2982                 *val = (unsigned long) opt->val;
2983                 break;
2984         }
2985
2986         BT_DBG("type 0x%2.2x len %u val 0x%lx", *type, opt->len, *val);
2987         return len;
2988 }
2989
2990 static void l2cap_add_conf_opt(void **ptr, u8 type, u8 len, unsigned long val)
2991 {
2992         struct l2cap_conf_opt *opt = *ptr;
2993
2994         BT_DBG("type 0x%2.2x len %u val 0x%lx", type, len, val);
2995
2996         opt->type = type;
2997         opt->len  = len;
2998
2999         switch (len) {
3000         case 1:
3001                 *((u8 *) opt->val)  = val;
3002                 break;
3003
3004         case 2:
3005                 put_unaligned_le16(val, opt->val);
3006                 break;
3007
3008         case 4:
3009                 put_unaligned_le32(val, opt->val);
3010                 break;
3011
3012         default:
3013                 memcpy(opt->val, (void *) val, len);
3014                 break;
3015         }
3016
3017         *ptr += L2CAP_CONF_OPT_SIZE + len;
3018 }
3019
3020 static void l2cap_add_opt_efs(void **ptr, struct l2cap_chan *chan)
3021 {
3022         struct l2cap_conf_efs efs;
3023
3024         switch (chan->mode) {
3025         case L2CAP_MODE_ERTM:
3026                 efs.id          = chan->local_id;
3027                 efs.stype       = chan->local_stype;
3028                 efs.msdu        = cpu_to_le16(chan->local_msdu);
3029                 efs.sdu_itime   = cpu_to_le32(chan->local_sdu_itime);
3030                 efs.acc_lat     = cpu_to_le32(L2CAP_DEFAULT_ACC_LAT);
3031                 efs.flush_to    = cpu_to_le32(L2CAP_EFS_DEFAULT_FLUSH_TO);
3032                 break;
3033
3034         case L2CAP_MODE_STREAMING:
3035                 efs.id          = 1;
3036                 efs.stype       = L2CAP_SERV_BESTEFFORT;
3037                 efs.msdu        = cpu_to_le16(chan->local_msdu);
3038                 efs.sdu_itime   = cpu_to_le32(chan->local_sdu_itime);
3039                 efs.acc_lat     = 0;
3040                 efs.flush_to    = 0;
3041                 break;
3042
3043         default:
3044                 return;
3045         }
3046
3047         l2cap_add_conf_opt(ptr, L2CAP_CONF_EFS, sizeof(efs),
3048                            (unsigned long) &efs);
3049 }
3050
3051 static void l2cap_ack_timeout(struct work_struct *work)
3052 {
3053         struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
3054                                                ack_timer.work);
3055         u16 frames_to_ack;
3056
3057         BT_DBG("chan %p", chan);
3058
3059         l2cap_chan_lock(chan);
3060
3061         frames_to_ack = __seq_offset(chan, chan->buffer_seq,
3062                                      chan->last_acked_seq);
3063
3064         if (frames_to_ack)
3065                 l2cap_send_rr_or_rnr(chan, 0);
3066
3067         l2cap_chan_unlock(chan);
3068         l2cap_chan_put(chan);
3069 }
3070
3071 int l2cap_ertm_init(struct l2cap_chan *chan)
3072 {
3073         int err;
3074
3075         chan->next_tx_seq = 0;
3076         chan->expected_tx_seq = 0;
3077         chan->expected_ack_seq = 0;
3078         chan->unacked_frames = 0;
3079         chan->buffer_seq = 0;
3080         chan->frames_sent = 0;
3081         chan->last_acked_seq = 0;
3082         chan->sdu = NULL;
3083         chan->sdu_last_frag = NULL;
3084         chan->sdu_len = 0;
3085
3086         skb_queue_head_init(&chan->tx_q);
3087
3088         chan->local_amp_id = AMP_ID_BREDR;
3089         chan->move_id = AMP_ID_BREDR;
3090         chan->move_state = L2CAP_MOVE_STABLE;
3091         chan->move_role = L2CAP_MOVE_ROLE_NONE;
3092
3093         if (chan->mode != L2CAP_MODE_ERTM)
3094                 return 0;
3095
3096         chan->rx_state = L2CAP_RX_STATE_RECV;
3097         chan->tx_state = L2CAP_TX_STATE_XMIT;
3098
3099         INIT_DELAYED_WORK(&chan->retrans_timer, l2cap_retrans_timeout);
3100         INIT_DELAYED_WORK(&chan->monitor_timer, l2cap_monitor_timeout);
3101         INIT_DELAYED_WORK(&chan->ack_timer, l2cap_ack_timeout);
3102
3103         skb_queue_head_init(&chan->srej_q);
3104
3105         err = l2cap_seq_list_init(&chan->srej_list, chan->tx_win);
3106         if (err < 0)
3107                 return err;
3108
3109         err = l2cap_seq_list_init(&chan->retrans_list, chan->remote_tx_win);
3110         if (err < 0)
3111                 l2cap_seq_list_free(&chan->srej_list);
3112
3113         return err;
3114 }
3115
3116 static inline __u8 l2cap_select_mode(__u8 mode, __u16 remote_feat_mask)
3117 {
3118         switch (mode) {
3119         case L2CAP_MODE_STREAMING:
3120         case L2CAP_MODE_ERTM:
3121                 if (l2cap_mode_supported(mode, remote_feat_mask))
3122                         return mode;
3123                 /* fall through */
3124         default:
3125                 return L2CAP_MODE_BASIC;
3126         }
3127 }
3128
3129 static inline bool __l2cap_ews_supported(struct l2cap_conn *conn)
3130 {
3131         return ((conn->local_fixed_chan & L2CAP_FC_A2MP) &&
3132                 (conn->feat_mask & L2CAP_FEAT_EXT_WINDOW));
3133 }
3134
3135 static inline bool __l2cap_efs_supported(struct l2cap_conn *conn)
3136 {
3137         return ((conn->local_fixed_chan & L2CAP_FC_A2MP) &&
3138                 (conn->feat_mask & L2CAP_FEAT_EXT_FLOW));
3139 }
3140
3141 static void __l2cap_set_ertm_timeouts(struct l2cap_chan *chan,
3142                                       struct l2cap_conf_rfc *rfc)
3143 {
3144         if (chan->local_amp_id != AMP_ID_BREDR && chan->hs_hcon) {
3145                 u64 ertm_to = chan->hs_hcon->hdev->amp_be_flush_to;
3146
3147                 /* Class 1 devices have must have ERTM timeouts
3148                  * exceeding the Link Supervision Timeout.  The
3149                  * default Link Supervision Timeout for AMP
3150                  * controllers is 10 seconds.
3151                  *
3152                  * Class 1 devices use 0xffffffff for their
3153                  * best-effort flush timeout, so the clamping logic
3154                  * will result in a timeout that meets the above
3155                  * requirement.  ERTM timeouts are 16-bit values, so
3156                  * the maximum timeout is 65.535 seconds.
3157                  */
3158
3159                 /* Convert timeout to milliseconds and round */
3160                 ertm_to = DIV_ROUND_UP_ULL(ertm_to, 1000);
3161
3162                 /* This is the recommended formula for class 2 devices
3163                  * that start ERTM timers when packets are sent to the
3164                  * controller.
3165                  */
3166                 ertm_to = 3 * ertm_to + 500;
3167
3168                 if (ertm_to > 0xffff)
3169                         ertm_to = 0xffff;
3170
3171                 rfc->retrans_timeout = cpu_to_le16((u16) ertm_to);
3172                 rfc->monitor_timeout = rfc->retrans_timeout;
3173         } else {
3174                 rfc->retrans_timeout = cpu_to_le16(L2CAP_DEFAULT_RETRANS_TO);
3175                 rfc->monitor_timeout = cpu_to_le16(L2CAP_DEFAULT_MONITOR_TO);
3176         }
3177 }
3178
3179 static inline void l2cap_txwin_setup(struct l2cap_chan *chan)
3180 {
3181         if (chan->tx_win > L2CAP_DEFAULT_TX_WINDOW &&
3182             __l2cap_ews_supported(chan->conn)) {
3183                 /* use extended control field */
3184                 set_bit(FLAG_EXT_CTRL, &chan->flags);
3185                 chan->tx_win_max = L2CAP_DEFAULT_EXT_WINDOW;
3186         } else {
3187                 chan->tx_win = min_t(u16, chan->tx_win,
3188                                      L2CAP_DEFAULT_TX_WINDOW);
3189                 chan->tx_win_max = L2CAP_DEFAULT_TX_WINDOW;
3190         }
3191         chan->ack_win = chan->tx_win;
3192 }
3193
3194 static int l2cap_build_conf_req(struct l2cap_chan *chan, void *data)
3195 {
3196         struct l2cap_conf_req *req = data;
3197         struct l2cap_conf_rfc rfc = { .mode = chan->mode };
3198         void *ptr = req->data;
3199         u16 size;
3200
3201         BT_DBG("chan %p", chan);
3202
3203         if (chan->num_conf_req || chan->num_conf_rsp)
3204                 goto done;
3205
3206         switch (chan->mode) {
3207         case L2CAP_MODE_STREAMING:
3208         case L2CAP_MODE_ERTM:
3209                 if (test_bit(CONF_STATE2_DEVICE, &chan->conf_state))
3210                         break;
3211
3212                 if (__l2cap_efs_supported(chan->conn))
3213                         set_bit(FLAG_EFS_ENABLE, &chan->flags);
3214
3215                 /* fall through */
3216         default:
3217                 chan->mode = l2cap_select_mode(rfc.mode, chan->conn->feat_mask);
3218                 break;
3219         }
3220
3221 done:
3222         if (chan->imtu != L2CAP_DEFAULT_MTU)
3223                 l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, chan->imtu);
3224
3225         switch (chan->mode) {
3226         case L2CAP_MODE_BASIC:
3227                 if (disable_ertm)
3228                         break;
3229
3230                 if (!(chan->conn->feat_mask & L2CAP_FEAT_ERTM) &&
3231                     !(chan->conn->feat_mask & L2CAP_FEAT_STREAMING))
3232                         break;
3233
3234                 rfc.mode            = L2CAP_MODE_BASIC;
3235                 rfc.txwin_size      = 0;
3236                 rfc.max_transmit    = 0;
3237                 rfc.retrans_timeout = 0;
3238                 rfc.monitor_timeout = 0;
3239                 rfc.max_pdu_size    = 0;
3240
3241                 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3242                                    (unsigned long) &rfc);
3243                 break;
3244
3245         case L2CAP_MODE_ERTM:
3246                 rfc.mode            = L2CAP_MODE_ERTM;
3247                 rfc.max_transmit    = chan->max_tx;
3248
3249                 __l2cap_set_ertm_timeouts(chan, &rfc);
3250
3251                 size = min_t(u16, L2CAP_DEFAULT_MAX_PDU_SIZE, chan->conn->mtu -
3252                              L2CAP_EXT_HDR_SIZE - L2CAP_SDULEN_SIZE -
3253                              L2CAP_FCS_SIZE);
3254                 rfc.max_pdu_size = cpu_to_le16(size);
3255
3256                 l2cap_txwin_setup(chan);
3257
3258                 rfc.txwin_size = min_t(u16, chan->tx_win,
3259                                        L2CAP_DEFAULT_TX_WINDOW);
3260
3261                 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3262                                    (unsigned long) &rfc);
3263
3264                 if (test_bit(FLAG_EFS_ENABLE, &chan->flags))
3265                         l2cap_add_opt_efs(&ptr, chan);
3266
3267                 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
3268                         l2cap_add_conf_opt(&ptr, L2CAP_CONF_EWS, 2,
3269                                            chan->tx_win);
3270
3271                 if (chan->conn->feat_mask & L2CAP_FEAT_FCS)
3272                         if (chan->fcs == L2CAP_FCS_NONE ||
3273                             test_bit(CONF_RECV_NO_FCS, &chan->conf_state)) {
3274                                 chan->fcs = L2CAP_FCS_NONE;
3275                                 l2cap_add_conf_opt(&ptr, L2CAP_CONF_FCS, 1,
3276                                      &nbs