net/bluetooth/rfcomm/core.c

   1 /*
   2    RFCOMM implementation for Linux Bluetooth stack (BlueZ).
   3    Copyright (C) 2002 Maxim Krasnyansky <maxk@qualcomm.com>
   4    Copyright (C) 2002 Marcel Holtmann <marcel@holtmann.org>
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License version 2 as
   8    published by the Free Software Foundation;
   9
  10    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  11    OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  12    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
  13    IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
  14    CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
  15    WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  16    ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  17    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  18
  19    ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
  20    COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
  21    SOFTWARE IS DISCLAIMED.
  22 */
  23
  24 /*
  25  * Bluetooth RFCOMM core.
  26  */
  27
  28 #include <linux/module.h>
  29 #include <linux/debugfs.h>
  30 #include <linux/kthread.h>
  31 #include <asm/unaligned.h>
  32
  33 #include <net/bluetooth/bluetooth.h>
  34 #include <net/bluetooth/hci_core.h>
  35 #include <net/bluetooth/l2cap.h>
  36 #include <net/bluetooth/rfcomm.h>
  37
  38 #include <trace/events/sock.h>
  39
  40 #define VERSION "1.11"
  41
  42 static bool disable_cfc;
  43 static bool l2cap_ertm;
  44 static int channel_mtu = -1;
  45
  46 static struct task_struct *rfcomm_thread;
  47
  48 static DEFINE_MUTEX(rfcomm_mutex);
  49 #define rfcomm_lock()   mutex_lock(&rfcomm_mutex)
  50 #define rfcomm_unlock() mutex_unlock(&rfcomm_mutex)
  51
  52
  53 static LIST_HEAD(session_list);
  54
  55 static int rfcomm_send_frame(struct rfcomm_session *s, u8 *data, int len);
  56 static int rfcomm_send_sabm(struct rfcomm_session *s, u8 dlci);
  57 static int rfcomm_send_disc(struct rfcomm_session *s, u8 dlci);
  58 static int rfcomm_queue_disc(struct rfcomm_dlc *d);
  59 static int rfcomm_send_nsc(struct rfcomm_session *s, int cr, u8 type);
  60 static int rfcomm_send_pn(struct rfcomm_session *s, int cr, struct rfcomm_dlc *d);
  61 static int rfcomm_send_msc(struct rfcomm_session *s, int cr, u8 dlci, u8 v24_sig);
  62 static int rfcomm_send_test(struct rfcomm_session *s, int cr, u8 *pattern, int len);
  63 static int rfcomm_send_credits(struct rfcomm_session *s, u8 addr, u8 credits);
  64 static void rfcomm_make_uih(struct sk_buff *skb, u8 addr);
  65
  66 static void rfcomm_process_connect(struct rfcomm_session *s);
  67
  68 static struct rfcomm_session *rfcomm_session_create(bdaddr_t *src,
  69                                                         bdaddr_t *dst,
  70                                                         u8 sec_level,
  71                                                         int *err);
  72 static struct rfcomm_session *rfcomm_session_get(bdaddr_t *src, bdaddr_t *dst);
  73 static struct rfcomm_session *rfcomm_session_del(struct rfcomm_session *s);
  74
  75 /* ---- RFCOMM frame parsing macros ---- */
  76 #define __get_dlci(b)     ((b & 0xfc) >> 2)
  77 #define __get_type(b)     ((b & 0xef))
  78
  79 #define __test_ea(b)      ((b & 0x01))
  80 #define __test_cr(b)      (!!(b & 0x02))
  81 #define __test_pf(b)      (!!(b & 0x10))
  82
  83 #define __session_dir(s)  ((s)->initiator ? 0x00 : 0x01)
  84
  85 #define __addr(cr, dlci)       (((dlci & 0x3f) << 2) | (cr << 1) | 0x01)
  86 #define __ctrl(type, pf)       (((type & 0xef) | (pf << 4)))
  87 #define __dlci(dir, chn)       (((chn & 0x1f) << 1) | dir)
  88 #define __srv_channel(dlci)    (dlci >> 1)
  89
  90 #define __len8(len)       (((len) << 1) | 1)
  91 #define __len16(len)      ((len) << 1)
  92
  93 /* MCC macros */
  94 #define __mcc_type(cr, type)   (((type << 2) | (cr << 1) | 0x01))
  95 #define __get_mcc_type(b) ((b & 0xfc) >> 2)
  96 #define __get_mcc_len(b)  ((b & 0xfe) >> 1)
  97
  98 /* RPN macros */
  99 #define __rpn_line_settings(data, stop, parity)  ((data & 0x3) | ((stop & 0x1) << 2) | ((parity & 0x7) << 3))
 100 #define __get_rpn_data_bits(line) ((line) & 0x3)
 101 #define __get_rpn_stop_bits(line) (((line) >> 2) & 0x1)
 102 #define __get_rpn_parity(line)    (((line) >> 3) & 0x7)
 103
 104 static DECLARE_WAIT_QUEUE_HEAD(rfcomm_wq);
 105
 106 static void rfcomm_schedule(void)
 107 {
 108         wake_up_all(&rfcomm_wq);
 109 }
 110
 111 /* ---- RFCOMM FCS computation ---- */
 112
 113 /* reversed, 8-bit, poly=0x07 */
 114 static unsigned char rfcomm_crc_table[256] = {
 115         0x00, 0x91, 0xe3, 0x72, 0x07, 0x96, 0xe4, 0x75,
 116         0x0e, 0x9f, 0xed, 0x7c, 0x09, 0x98, 0xea, 0x7b,
 117         0x1c, 0x8d, 0xff, 0x6e, 0x1b, 0x8a, 0xf8, 0x69,
 118         0x12, 0x83, 0xf1, 0x60, 0x15, 0x84, 0xf6, 0x67,
 119
 120         0x38, 0xa9, 0xdb, 0x4a, 0x3f, 0xae, 0xdc, 0x4d,
 121         0x36, 0xa7, 0xd5, 0x44, 0x31, 0xa0, 0xd2, 0x43,
 122         0x24, 0xb5, 0xc7, 0x56, 0x23, 0xb2, 0xc0, 0x51,
 123         0x2a, 0xbb, 0xc9, 0x58, 0x2d, 0xbc, 0xce, 0x5f,
 124
 125         0x70, 0xe1, 0x93, 0x02, 0x77, 0xe6, 0x94, 0x05,
 126         0x7e, 0xef, 0x9d, 0x0c, 0x79, 0xe8, 0x9a, 0x0b,
 127         0x6c, 0xfd, 0x8f, 0x1e, 0x6b, 0xfa, 0x88, 0x19,
 128         0x62, 0xf3, 0x81, 0x10, 0x65, 0xf4, 0x86, 0x17,
 129
 130         0x48, 0xd9, 0xab, 0x3a, 0x4f, 0xde, 0xac, 0x3d,
 131         0x46, 0xd7, 0xa5, 0x34, 0x41, 0xd0, 0xa2, 0x33,
 132         0x54, 0xc5, 0xb7, 0x26, 0x53, 0xc2, 0xb0, 0x21,
 133         0x5a, 0xcb, 0xb9, 0x28, 0x5d, 0xcc, 0xbe, 0x2f,
 134
 135         0xe0, 0x71, 0x03, 0x92, 0xe7, 0x76, 0x04, 0x95,
 136         0xee, 0x7f, 0x0d, 0x9c, 0xe9, 0x78, 0x0a, 0x9b,
 137         0xfc, 0x6d, 0x1f, 0x8e, 0xfb, 0x6a, 0x18, 0x89,
 138         0xf2, 0x63, 0x11, 0x80, 0xf5, 0x64, 0x16, 0x87,
 139
 140         0xd8, 0x49, 0x3b, 0xaa, 0xdf, 0x4e, 0x3c, 0xad,
 141         0xd6, 0x47, 0x35, 0xa4, 0xd1, 0x40, 0x32, 0xa3,
 142         0xc4, 0x55, 0x27, 0xb6, 0xc3, 0x52, 0x20, 0xb1,
 143         0xca, 0x5b, 0x29, 0xb8, 0xcd, 0x5c, 0x2e, 0xbf,
 144
 145         0x90, 0x01, 0x73, 0xe2, 0x97, 0x06, 0x74, 0xe5,
 146         0x9e, 0x0f, 0x7d, 0xec, 0x99, 0x08, 0x7a, 0xeb,
 147         0x8c, 0x1d, 0x6f, 0xfe, 0x8b, 0x1a, 0x68, 0xf9,
 148         0x82, 0x13, 0x61, 0xf0, 0x85, 0x14, 0x66, 0xf7,
 149
 150         0xa8, 0x39, 0x4b, 0xda, 0xaf, 0x3e, 0x4c, 0xdd,
 151         0xa6, 0x37, 0x45, 0xd4, 0xa1, 0x30, 0x42, 0xd3,
 152         0xb4, 0x25, 0x57, 0xc6, 0xb3, 0x22, 0x50, 0xc1,
 153         0xba, 0x2b, 0x59, 0xc8, 0xbd, 0x2c, 0x5e, 0xcf
 154 };
 155
 156 /* CRC on 2 bytes */
 157 #define __crc(data) (rfcomm_crc_table[rfcomm_crc_table[0xff ^ data[0]] ^ data[1]])
 158
 159 /* FCS on 2 bytes */
 160 static inline u8 __fcs(u8 *data)
 161 {
 162         return 0xff - __crc(data);
 163 }
 164
 165 /* FCS on 3 bytes */
 166 static inline u8 __fcs2(u8 *data)
 167 {
 168         return 0xff - rfcomm_crc_table[__crc(data) ^ data[2]];
 169 }
 170
 171 /* Check FCS */
 172 static inline int __check_fcs(u8 *data, int type, u8 fcs)
 173 {
 174         u8 f = __crc(data);
 175
 176         if (type != RFCOMM_UIH)
 177                 f = rfcomm_crc_table[f ^ data[2]];
 178
 179         return rfcomm_crc_table[f ^ fcs] != 0xcf;
 180 }
 181
 182 /* ---- L2CAP callbacks ---- */
 183 static void rfcomm_l2state_change(struct sock *sk)
 184 {
 185         BT_DBG("%p state %d", sk, sk->sk_state);
 186         rfcomm_schedule();
 187 }
 188
 189 static void rfcomm_l2data_ready(struct sock *sk)
 190 {
 191         trace_sk_data_ready(sk);
 192
 193         BT_DBG("%p", sk);
 194         rfcomm_schedule();
 195 }
 196
 197 static int rfcomm_l2sock_create(struct socket **sock)
 198 {
 199         int err;
 200
 201         BT_DBG("");
 202
 203         err = sock_create_kern(&init_net, PF_BLUETOOTH, SOCK_SEQPACKET, BTPROTO_L2CAP, sock);
 204         if (!err) {
 205                 struct sock *sk = (*sock)->sk;
 206                 sk->sk_data_ready   = rfcomm_l2data_ready;
 207                 sk->sk_state_change = rfcomm_l2state_change;
 208         }
 209         return err;
 210 }
 211
 212 static int rfcomm_check_security(struct rfcomm_dlc *d)
 213 {
 214         struct sock *sk = d->session->sock->sk;
 215         struct l2cap_conn *conn = l2cap_pi(sk)->chan->conn;
 216
 217         __u8 auth_type;
 218
 219         switch (d->sec_level) {
 220         case BT_SECURITY_HIGH:
 221         case BT_SECURITY_FIPS:
 222                 auth_type = HCI_AT_GENERAL_BONDING_MITM;
 223                 break;
 224         case BT_SECURITY_MEDIUM:
 225                 auth_type = HCI_AT_GENERAL_BONDING;
 226                 break;
 227         default:
 228                 auth_type = HCI_AT_NO_BONDING;
 229                 break;
 230         }
 231
 232         return hci_conn_security(conn->hcon, d->sec_level, auth_type,
 233                                  d->out);
 234 }
 235
 236 static void rfcomm_session_timeout(struct timer_list *t)
 237 {
 238         struct rfcomm_session *s = from_timer(s, t, timer);
 239
 240         BT_DBG("session %p state %ld", s, s->state);
 241
 242         set_bit(RFCOMM_TIMED_OUT, &s->flags);
 243         rfcomm_schedule();
 244 }
 245
 246 static void rfcomm_session_set_timer(struct rfcomm_session *s, long timeout)
 247 {
 248         BT_DBG("session %p state %ld timeout %ld", s, s->state, timeout);
 249
 250         mod_timer(&s->timer, jiffies + timeout);
 251 }
 252
 253 static void rfcomm_session_clear_timer(struct rfcomm_session *s)
 254 {
 255         BT_DBG("session %p state %ld", s, s->state);
 256
 257         del_timer_sync(&s->timer);
 258 }
 259
 260 /* ---- RFCOMM DLCs ---- */
 261 static void rfcomm_dlc_timeout(struct timer_list *t)
 262 {
 263         struct rfcomm_dlc *d = from_timer(d, t, timer);
 264
 265         BT_DBG("dlc %p state %ld", d, d->state);
 266
 267         set_bit(RFCOMM_TIMED_OUT, &d->flags);
 268         rfcomm_dlc_put(d);
 269         rfcomm_schedule();
 270 }
 271
 272 static void rfcomm_dlc_set_timer(struct rfcomm_dlc *d, long timeout)
 273 {
 274         BT_DBG("dlc %p state %ld timeout %ld", d, d->state, timeout);
 275
 276         if (!mod_timer(&d->timer, jiffies + timeout))
 277                 rfcomm_dlc_hold(d);
 278 }
 279
 280 static void rfcomm_dlc_clear_timer(struct rfcomm_dlc *d)
 281 {
 282         BT_DBG("dlc %p state %ld", d, d->state);
 283
 284         if (del_timer(&d->timer))
 285                 rfcomm_dlc_put(d);
 286 }
 287
 288 static void rfcomm_dlc_clear_state(struct rfcomm_dlc *d)
 289 {
 290         BT_DBG("%p", d);
 291
 292         d->state      = BT_OPEN;
 293         d->flags      = 0;
 294         d->mscex      = 0;
 295         d->sec_level  = BT_SECURITY_LOW;
 296         d->mtu        = RFCOMM_DEFAULT_MTU;
 297         d->v24_sig    = RFCOMM_V24_RTC | RFCOMM_V24_RTR | RFCOMM_V24_DV;
 298
 299         d->cfc        = RFCOMM_CFC_DISABLED;
 300         d->rx_credits = RFCOMM_DEFAULT_CREDITS;
 301 }
 302
 303 struct rfcomm_dlc *rfcomm_dlc_alloc(gfp_t prio)
 304 {
 305         struct rfcomm_dlc *d = kzalloc(sizeof(*d), prio);
 306
 307         if (!d)
 308                 return NULL;
 309
 310         timer_setup(&d->timer, rfcomm_dlc_timeout, 0);
 311
 312         skb_queue_head_init(&d->tx_queue);
 313         mutex_init(&d->lock);
 314         refcount_set(&d->refcnt, 1);
 315
 316         rfcomm_dlc_clear_state(d);
 317
 318         BT_DBG("%p", d);
 319
 320         return d;
 321 }
 322
 323 void rfcomm_dlc_free(struct rfcomm_dlc *d)
 324 {
 325         BT_DBG("%p", d);
 326
 327         skb_queue_purge(&d->tx_queue);
 328         kfree(d);
 329 }
 330
 331 static void rfcomm_dlc_link(struct rfcomm_session *s, struct rfcomm_dlc *d)
 332 {
 333         BT_DBG("dlc %p session %p", d, s);
 334
 335         rfcomm_session_clear_timer(s);
 336         rfcomm_dlc_hold(d);
 337         list_add(&d->list, &s->dlcs);
 338         d->session = s;
 339 }
 340
 341 static void rfcomm_dlc_unlink(struct rfcomm_dlc *d)
 342 {
 343         struct rfcomm_session *s = d->session;
 344
 345         BT_DBG("dlc %p refcnt %d session %p", d, refcount_read(&d->refcnt), s);
 346
 347         list_del(&d->list);
 348         d->session = NULL;
 349         rfcomm_dlc_put(d);
 350
 351         if (list_empty(&s->dlcs))
 352                 rfcomm_session_set_timer(s, RFCOMM_IDLE_TIMEOUT);
 353 }
 354
 355 static struct rfcomm_dlc *rfcomm_dlc_get(struct rfcomm_session *s, u8 dlci)
 356 {
 357         struct rfcomm_dlc *d;
 358
 359         list_for_each_entry(d, &s->dlcs, list)
 360                 if (d->dlci == dlci)
 361                         return d;
 362
 363         return NULL;
 364 }
 365
 366 static int rfcomm_check_channel(u8 channel)
 367 {
 368         return channel < 1 || channel > 30;
 369 }
 370
 371 static int __rfcomm_dlc_open(struct rfcomm_dlc *d, bdaddr_t *src, bdaddr_t *dst, u8 channel)
 372 {
 373         struct rfcomm_session *s;
 374         int err = 0;
 375         u8 dlci;
 376
 377         BT_DBG("dlc %p state %ld %pMR -> %pMR channel %d",
 378                d, d->state, src, dst, channel);
 379
 380         if (rfcomm_check_channel(channel))
 381                 return -EINVAL;
 382
 383         if (d->state != BT_OPEN && d->state != BT_CLOSED)
 384                 return 0;
 385
 386         s = rfcomm_session_get(src, dst);
 387         if (!s) {
 388                 s = rfcomm_session_create(src, dst, d->sec_level, &err);
 389                 if (!s)
 390                         return err;
 391         }
 392
 393         dlci = __dlci(__session_dir(s), channel);
 394
 395         /* Check if DLCI already exists */
 396         if (rfcomm_dlc_get(s, dlci))
 397                 return -EBUSY;
 398
 399         rfcomm_dlc_clear_state(d);
 400
 401         d->dlci     = dlci;
 402         d->addr     = __addr(s->initiator, dlci);
 403         d->priority = 7;
 404
 405         d->state = BT_CONFIG;
 406         rfcomm_dlc_link(s, d);
 407
 408         d->out = 1;
 409
 410         d->mtu = s->mtu;
 411         d->cfc = (s->cfc == RFCOMM_CFC_UNKNOWN) ? 0 : s->cfc;
 412
 413         if (s->state == BT_CONNECTED) {
 414                 if (rfcomm_check_security(d))
 415                         rfcomm_send_pn(s, 1, d);
 416                 else
 417                         set_bit(RFCOMM_AUTH_PENDING, &d->flags);
 418         }
 419
 420         rfcomm_dlc_set_timer(d, RFCOMM_CONN_TIMEOUT);
 421
 422         return 0;
 423 }
 424
 425 int rfcomm_dlc_open(struct rfcomm_dlc *d, bdaddr_t *src, bdaddr_t *dst, u8 channel)
 426 {
 427         int r;
 428
 429         rfcomm_lock();
 430
 431         r = __rfcomm_dlc_open(d, src, dst, channel);
 432
 433         rfcomm_unlock();
 434         return r;
 435 }
 436
 437 static void __rfcomm_dlc_disconn(struct rfcomm_dlc *d)
 438 {
 439         struct rfcomm_session *s = d->session;
 440
 441         d->state = BT_DISCONN;
 442         if (skb_queue_empty(&d->tx_queue)) {
 443                 rfcomm_send_disc(s, d->dlci);
 444                 rfcomm_dlc_set_timer(d, RFCOMM_DISC_TIMEOUT);
 445         } else {
 446                 rfcomm_queue_disc(d);
 447                 rfcomm_dlc_set_timer(d, RFCOMM_DISC_TIMEOUT * 2);
 448         }
 449 }
 450
 451 static int __rfcomm_dlc_close(struct rfcomm_dlc *d, int err)
 452 {
 453         struct rfcomm_session *s = d->session;
 454         if (!s)
 455                 return 0;
 456
 457         BT_DBG("dlc %p state %ld dlci %d err %d session %p",
 458                         d, d->state, d->dlci, err, s);
 459
 460         switch (d->state) {
 461         case BT_CONNECT:
 462         case BT_CONFIG:
 463         case BT_OPEN:
 464         case BT_CONNECT2:
 465                 if (test_and_clear_bit(RFCOMM_DEFER_SETUP, &d->flags)) {
 466                         set_bit(RFCOMM_AUTH_REJECT, &d->flags);
 467                         rfcomm_schedule();
 468                         return 0;
 469                 }
 470         }
 471
 472         switch (d->state) {
 473         case BT_CONNECT:
 474         case BT_CONNECTED:
 475                 __rfcomm_dlc_disconn(d);
 476                 break;
 477
 478         case BT_CONFIG:
 479                 if (s->state != BT_BOUND) {
 480                         __rfcomm_dlc_disconn(d);
 481                         break;
 482                 }
 483                 /* if closing a dlc in a session that hasn't been started,
 484                  * just close and unlink the dlc
 485                  */
 486                 fallthrough;
 487
 488         default:
 489                 rfcomm_dlc_clear_timer(d);
 490
 491                 rfcomm_dlc_lock(d);
 492                 d->state = BT_CLOSED;
 493                 d->state_change(d, err);
 494                 rfcomm_dlc_unlock(d);
 495
 496                 skb_queue_purge(&d->tx_queue);
 497                 rfcomm_dlc_unlink(d);
 498         }
 499
 500         return 0;
 501 }
 502
 503 int rfcomm_dlc_close(struct rfcomm_dlc *d, int err)
 504 {
 505         int r = 0;
 506         struct rfcomm_dlc *d_list;
 507         struct rfcomm_session *s, *s_list;
 508
 509         BT_DBG("dlc %p state %ld dlci %d err %d", d, d->state, d->dlci, err);
 510
 511         rfcomm_lock();
 512
 513         s = d->session;
 514         if (!s)
 515                 goto no_session;
 516
 517         /* after waiting on the mutex check the session still exists
 518          * then check the dlc still exists
 519          */
 520         list_for_each_entry(s_list, &session_list, list) {
 521                 if (s_list == s) {
 522                         list_for_each_entry(d_list, &s->dlcs, list) {
 523                                 if (d_list == d) {
 524                                         r = __rfcomm_dlc_close(d, err);
 525                                         break;
 526                                 }
 527                         }
 528                         break;
 529                 }
 530         }
 531
 532 no_session:
 533         rfcomm_unlock();
 534         return r;
 535 }
 536
 537 struct rfcomm_dlc *rfcomm_dlc_exists(bdaddr_t *src, bdaddr_t *dst, u8 channel)
 538 {
 539         struct rfcomm_session *s;
 540         struct rfcomm_dlc *dlc = NULL;
 541         u8 dlci;
 542
 543         if (rfcomm_check_channel(channel))
 544                 return ERR_PTR(-EINVAL);
 545
 546         rfcomm_lock();
 547         s = rfcomm_session_get(src, dst);
 548         if (s) {
 549                 dlci = __dlci(__session_dir(s), channel);
 550                 dlc = rfcomm_dlc_get(s, dlci);
 551         }
 552         rfcomm_unlock();
 553         return dlc;
 554 }
 555
 556 static int rfcomm_dlc_send_frag(struct rfcomm_dlc *d, struct sk_buff *frag)
 557 {
 558         int len = frag->len;
 559
 560         BT_DBG("dlc %p mtu %d len %d", d, d->mtu, len);
 561
 562         if (len > d->mtu)
 563                 return -EINVAL;
 564
 565         rfcomm_make_uih(frag, d->addr);
 566         __skb_queue_tail(&d->tx_queue, frag);
 567
 568         return len;
 569 }
 570
 571 int rfcomm_dlc_send(struct rfcomm_dlc *d, struct sk_buff *skb)
 572 {
 573         unsigned long flags;
 574         struct sk_buff *frag, *next;
 575         int len;
 576
 577         if (d->state != BT_CONNECTED)
 578                 return -ENOTCONN;
 579
 580         frag = skb_shinfo(skb)->frag_list;
 581         skb_shinfo(skb)->frag_list = NULL;
 582
 583         /* Queue all fragments atomically. */
 584         spin_lock_irqsave(&d->tx_queue.lock, flags);
 585
 586         len = rfcomm_dlc_send_frag(d, skb);
 587         if (len < 0 || !frag)
 588                 goto unlock;
 589
 590         for (; frag; frag = next) {
 591                 int ret;
 592
 593                 next = frag->next;
 594
 595                 ret = rfcomm_dlc_send_frag(d, frag);
 596                 if (ret < 0) {
 597                         dev_kfree_skb_irq(frag);
 598                         goto unlock;
 599                 }
 600
 601                 len += ret;
 602         }
 603
 604 unlock:
 605         spin_unlock_irqrestore(&d->tx_queue.lock, flags);
 606
 607         if (len > 0 && !test_bit(RFCOMM_TX_THROTTLED, &d->flags))
 608                 rfcomm_schedule();
 609         return len;
 610 }
 611
 612 void rfcomm_dlc_send_noerror(struct rfcomm_dlc *d, struct sk_buff *skb)
 613 {
 614         int len = skb->len;
 615
 616         BT_DBG("dlc %p mtu %d len %d", d, d->mtu, len);
 617
 618         rfcomm_make_uih(skb, d->addr);
 619         skb_queue_tail(&d->tx_queue, skb);
 620
 621         if (d->state == BT_CONNECTED &&
 622             !test_bit(RFCOMM_TX_THROTTLED, &d->flags))
 623                 rfcomm_schedule();
 624 }
 625
 626 void __rfcomm_dlc_throttle(struct rfcomm_dlc *d)
 627 {
 628         BT_DBG("dlc %p state %ld", d, d->state);
 629
 630         if (!d->cfc) {
 631                 d->v24_sig |= RFCOMM_V24_FC;
 632                 set_bit(RFCOMM_MSC_PENDING, &d->flags);
 633         }
 634         rfcomm_schedule();
 635 }
 636
 637 void __rfcomm_dlc_unthrottle(struct rfcomm_dlc *d)
 638 {
 639         BT_DBG("dlc %p state %ld", d, d->state);
 640
 641         if (!d->cfc) {
 642                 d->v24_sig &= ~RFCOMM_V24_FC;
 643                 set_bit(RFCOMM_MSC_PENDING, &d->flags);
 644         }
 645         rfcomm_schedule();
 646 }
 647
 648 /*
 649    Set/get modem status functions use _local_ status i.e. what we report
 650    to the other side.
 651    Remote status is provided by dlc->modem_status() callback.
 652  */
 653 int rfcomm_dlc_set_modem_status(struct rfcomm_dlc *d, u8 v24_sig)
 654 {
 655         BT_DBG("dlc %p state %ld v24_sig 0x%x",
 656                         d, d->state, v24_sig);
 657
 658         if (test_bit(RFCOMM_RX_THROTTLED, &d->flags))
 659                 v24_sig |= RFCOMM_V24_FC;
 660         else
 661                 v24_sig &= ~RFCOMM_V24_FC;
 662
 663         d->v24_sig = v24_sig;
 664
 665         if (!test_and_set_bit(RFCOMM_MSC_PENDING, &d->flags))
 666                 rfcomm_schedule();
 667
 668         return 0;
 669 }
 670
 671 int rfcomm_dlc_get_modem_status(struct rfcomm_dlc *d, u8 *v24_sig)
 672 {
 673         BT_DBG("dlc %p state %ld v24_sig 0x%x",
 674                         d, d->state, d->v24_sig);
 675
 676         *v24_sig = d->v24_sig;
 677         return 0;
 678 }
 679
 680 /* ---- RFCOMM sessions ---- */
 681 static struct rfcomm_session *rfcomm_session_add(struct socket *sock, int state)
 682 {
 683         struct rfcomm_session *s = kzalloc(sizeof(*s), GFP_KERNEL);
 684
 685         if (!s)
 686                 return NULL;
 687
 688         BT_DBG("session %p sock %p", s, sock);
 689
 690         timer_setup(&s->timer, rfcomm_session_timeout, 0);
 691
 692         INIT_LIST_HEAD(&s->dlcs);
 693         s->state = state;
 694         s->sock  = sock;
 695
 696         s->mtu = RFCOMM_DEFAULT_MTU;
 697         s->cfc = disable_cfc ? RFCOMM_CFC_DISABLED : RFCOMM_CFC_UNKNOWN;
 698
 699         /* Do not increment module usage count for listening sessions.
 700          * Otherwise we won't be able to unload the module. */
 701         if (state != BT_LISTEN)
 702                 if (!try_module_get(THIS_MODULE)) {
 703                         kfree(s);
 704                         return NULL;
 705                 }
 706
 707         list_add(&s->list, &session_list);
 708
 709         return s;
 710 }
 711
 712 static struct rfcomm_session *rfcomm_session_del(struct rfcomm_session *s)
 713 {
 714         int state = s->state;
 715
 716         BT_DBG("session %p state %ld", s, s->state);
 717
 718         list_del(&s->list);
 719
 720         rfcomm_session_clear_timer(s);
 721         sock_release(s->sock);
 722         kfree(s);
 723
 724         if (state != BT_LISTEN)
 725                 module_put(THIS_MODULE);
 726
 727         return NULL;
 728 }
 729
 730 static struct rfcomm_session *rfcomm_session_get(bdaddr_t *src, bdaddr_t *dst)
 731 {
 732         struct rfcomm_session *s, *n;
 733         struct l2cap_chan *chan;
 734         list_for_each_entry_safe(s, n, &session_list, list) {
 735                 chan = l2cap_pi(s->sock->sk)->chan;
 736
 737                 if ((!bacmp(src, BDADDR_ANY) || !bacmp(&chan->src, src)) &&
 738                     !bacmp(&chan->dst, dst))
 739                         return s;
 740         }
 741         return NULL;
 742 }
 743
 744 static struct rfcomm_session *rfcomm_session_close(struct rfcomm_session *s,
 745                                                    int err)
 746 {
 747         struct rfcomm_dlc *d, *n;
 748
 749         s->state = BT_CLOSED;
 750
 751         BT_DBG("session %p state %ld err %d", s, s->state, err);
 752
 753         /* Close all dlcs */
 754         list_for_each_entry_safe(d, n, &s->dlcs, list) {
 755                 d->state = BT_CLOSED;
 756                 __rfcomm_dlc_close(d, err);
 757         }
 758
 759         rfcomm_session_clear_timer(s);
 760         return rfcomm_session_del(s);
 761 }
 762
 763 static struct rfcomm_session *rfcomm_session_create(bdaddr_t *src,
 764                                                         bdaddr_t *dst,
 765                                                         u8 sec_level,
 766                                                         int *err)
 767 {
 768         struct rfcomm_session *s = NULL;
 769         struct sockaddr_l2 addr;
 770         struct socket *sock;
 771         struct sock *sk;
 772
 773         BT_DBG("%pMR -> %pMR", src, dst);
 774
 775         *err = rfcomm_l2sock_create(&sock);
 776         if (*err < 0)
 777                 return NULL;
 778
 779         bacpy(&addr.l2_bdaddr, src);
 780         addr.l2_family = AF_BLUETOOTH;
 781         addr.l2_psm    = 0;
 782         addr.l2_cid    = 0;
 783         addr.l2_bdaddr_type = BDADDR_BREDR;
 784         *err = kernel_bind(sock, (struct sockaddr *) &addr, sizeof(addr));
 785         if (*err < 0)
 786                 goto failed;
 787
 788         /* Set L2CAP options */
 789         sk = sock->sk;
 790         lock_sock(sk);
 791         /* Set MTU to 0 so L2CAP can auto select the MTU */
 792         l2cap_pi(sk)->chan->imtu = 0;
 793         l2cap_pi(sk)->chan->sec_level = sec_level;
 794         if (l2cap_ertm)
 795                 l2cap_pi(sk)->chan->mode = L2CAP_MODE_ERTM;
 796         release_sock(sk);
 797
 798         s = rfcomm_session_add(sock, BT_BOUND);
 799         if (!s) {
 800                 *err = -ENOMEM;
 801                 goto failed;
 802         }
 803
 804         s->initiator = 1;
 805
 806         bacpy(&addr.l2_bdaddr, dst);
 807         addr.l2_family = AF_BLUETOOTH;
 808         addr.l2_psm    = cpu_to_le16(L2CAP_PSM_RFCOMM);
 809         addr.l2_cid    = 0;
 810         addr.l2_bdaddr_type = BDADDR_BREDR;
 811         *err = kernel_connect(sock, (struct sockaddr *) &addr, sizeof(addr), O_NONBLOCK);
 812         if (*err == 0 || *err == -EINPROGRESS)
 813                 return s;
 814
 815         return rfcomm_session_del(s);
 816
 817 failed:
 818         sock_release(sock);
 819         return NULL;
 820 }
 821
 822 void rfcomm_session_getaddr(struct rfcomm_session *s, bdaddr_t *src, bdaddr_t *dst)
 823 {
 824         struct l2cap_chan *chan = l2cap_pi(s->sock->sk)->chan;
 825         if (src)
 826                 bacpy(src, &chan->src);
 827         if (dst)
 828                 bacpy(dst, &chan->dst);
 829 }
 830
 831 /* ---- RFCOMM frame sending ---- */
 832 static int rfcomm_send_frame(struct rfcomm_session *s, u8 *data, int len)
 833 {
 834         struct kvec iv = { data, len };
 835         struct msghdr msg;
 836
 837         BT_DBG("session %p len %d", s, len);
 838
 839         memset(&msg, 0, sizeof(msg));
 840
 841         return kernel_sendmsg(s->sock, &msg, &iv, 1, len);
 842 }
 843
 844 static int rfcomm_send_cmd(struct rfcomm_session *s, struct rfcomm_cmd *cmd)
 845 {
 846         BT_DBG("%p cmd %u", s, cmd->ctrl);
 847
 848         return rfcomm_send_frame(s, (void *) cmd, sizeof(*cmd));
 849 }
 850
 851 static int rfcomm_send_sabm(struct rfcomm_session *s, u8 dlci)
 852 {
 853         struct rfcomm_cmd cmd;
 854
 855         BT_DBG("%p dlci %d", s, dlci);
 856
 857         cmd.addr = __addr(s->initiator, dlci);
 858         cmd.ctrl = __ctrl(RFCOMM_SABM, 1);
 859         cmd.len  = __len8(0);
 860         cmd.fcs  = __fcs2((u8 *) &cmd);
 861
 862         return rfcomm_send_cmd(s, &cmd);
 863 }
 864
 865 static int rfcomm_send_ua(struct rfcomm_session *s, u8 dlci)
 866 {
 867         struct rfcomm_cmd cmd;
 868
 869         BT_DBG("%p dlci %d", s, dlci);
 870
 871         cmd.addr = __addr(!s->initiator, dlci);
 872         cmd.ctrl = __ctrl(RFCOMM_UA, 1);
 873         cmd.len  = __len8(0);
 874         cmd.fcs  = __fcs2((u8 *) &cmd);
 875
 876         return rfcomm_send_cmd(s, &cmd);
 877 }
 878
 879 static int rfcomm_send_disc(struct rfcomm_session *s, u8 dlci)
 880 {
 881         struct rfcomm_cmd cmd;
 882
 883         BT_DBG("%p dlci %d", s, dlci);
 884
 885         cmd.addr = __addr(s->initiator, dlci);
 886         cmd.ctrl = __ctrl(RFCOMM_DISC, 1);
 887         cmd.len  = __len8(0);
 888         cmd.fcs  = __fcs2((u8 *) &cmd);
 889
 890         return rfcomm_send_cmd(s, &cmd);
 891 }
 892
 893 static int rfcomm_queue_disc(struct rfcomm_dlc *d)
 894 {
 895         struct rfcomm_cmd *cmd;
 896         struct sk_buff *skb;
 897
 898         BT_DBG("dlc %p dlci %d", d, d->dlci);
 899
 900         skb = alloc_skb(sizeof(*cmd), GFP_KERNEL);
 901         if (!skb)
 902                 return -ENOMEM;
 903
 904         cmd = __skb_put(skb, sizeof(*cmd));
 905         cmd->addr = d->addr;
 906         cmd->ctrl = __ctrl(RFCOMM_DISC, 1);
 907         cmd->len  = __len8(0);
 908         cmd->fcs  = __fcs2((u8 *) cmd);
 909
 910         skb_queue_tail(&d->tx_queue, skb);
 911         rfcomm_schedule();
 912         return 0;
 913 }
 914
 915 static int rfcomm_send_dm(struct rfcomm_session *s, u8 dlci)
 916 {
 917         struct rfcomm_cmd cmd;
 918
 919         BT_DBG("%p dlci %d", s, dlci);
 920
 921         cmd.addr = __addr(!s->initiator, dlci);
 922         cmd.ctrl = __ctrl(RFCOMM_DM, 1);
 923         cmd.len  = __len8(0);
 924         cmd.fcs  = __fcs2((u8 *) &cmd);
 925
 926         return rfcomm_send_cmd(s, &cmd);
 927 }
 928
 929 static int rfcomm_send_nsc(struct rfcomm_session *s, int cr, u8 type)
 930 {
 931         struct rfcomm_hdr *hdr;
 932         struct rfcomm_mcc *mcc;
 933         u8 buf[16], *ptr = buf;
 934
 935         BT_DBG("%p cr %d type %d", s, cr, type);
 936
 937         hdr = (void *) ptr; ptr += sizeof(*hdr);
 938         hdr->addr = __addr(s->initiator, 0);
 939         hdr->ctrl = __ctrl(RFCOMM_UIH, 0);
 940         hdr->len  = __len8(sizeof(*mcc) + 1);
 941
 942         mcc = (void *) ptr; ptr += sizeof(*mcc);
 943         mcc->type = __mcc_type(0, RFCOMM_NSC);
 944         mcc->len  = __len8(1);
 945
 946         /* Type that we didn't like */
 947         *ptr = __mcc_type(cr, type); ptr++;
 948
 949         *ptr = __fcs(buf); ptr++;
 950
 951         return rfcomm_send_frame(s, buf, ptr - buf);
 952 }
 953
 954 static int rfcomm_send_pn(struct rfcomm_session *s, int cr, struct rfcomm_dlc *d)
 955 {
 956         struct rfcomm_hdr *hdr;
 957         struct rfcomm_mcc *mcc;
 958         struct rfcomm_pn  *pn;
 959         u8 buf[16], *ptr = buf;
 960
 961         BT_DBG("%p cr %d dlci %d mtu %d", s, cr, d->dlci, d->mtu);
 962
 963         hdr = (void *) ptr; ptr += sizeof(*hdr);
 964         hdr->addr = __addr(s->initiator, 0);
 965         hdr->ctrl = __ctrl(RFCOMM_UIH, 0);
 966         hdr->len  = __len8(sizeof(*mcc) + sizeof(*pn));
 967
 968         mcc = (void *) ptr; ptr += sizeof(*mcc);
 969         mcc->type = __mcc_type(cr, RFCOMM_PN);
 970         mcc->len  = __len8(sizeof(*pn));
 971
 972         pn = (void *) ptr; ptr += sizeof(*pn);
 973         pn->dlci        = d->dlci;
 974         pn->priority    = d->priority;
 975         pn->ack_timer   = 0;
 976         pn->max_retrans = 0;
 977
 978         if (s->cfc) {
 979                 pn->flow_ctrl = cr ? 0xf0 : 0xe0;
 980                 pn->credits = RFCOMM_DEFAULT_CREDITS;
 981         } else {
 982                 pn->flow_ctrl = 0;
 983                 pn->credits   = 0;
 984         }
 985
 986         if (cr && channel_mtu >= 0)
 987                 pn->mtu = cpu_to_le16(channel_mtu);
 988         else
 989                 pn->mtu = cpu_to_le16(d->mtu);
 990
 991         *ptr = __fcs(buf); ptr++;
 992
 993         return rfcomm_send_frame(s, buf, ptr - buf);
 994 }
 995
 996 int rfcomm_send_rpn(struct rfcomm_session *s, int cr, u8 dlci,
 997                         u8 bit_rate, u8 data_bits, u8 stop_bits,
 998                         u8 parity, u8 flow_ctrl_settings,
 999                         u8 xon_char, u8 xoff_char, u16 param_mask)
1000 {
1001         struct rfcomm_hdr *hdr;
1002         struct rfcomm_mcc *mcc;
1003         struct rfcomm_rpn *rpn;
1004         u8 buf[16], *ptr = buf;
1005
1006         BT_DBG("%p cr %d dlci %d bit_r 0x%x data_b 0x%x stop_b 0x%x parity 0x%x"
1007                         " flwc_s 0x%x xon_c 0x%x xoff_c 0x%x p_mask 0x%x",
1008                 s, cr, dlci, bit_rate, data_bits, stop_bits, parity,
1009                 flow_ctrl_settings, xon_char, xoff_char, param_mask);
1010
1011         hdr = (void *) ptr; ptr += sizeof(*hdr);
1012         hdr->addr = __addr(s->initiator, 0);
1013         hdr->ctrl = __ctrl(RFCOMM_UIH, 0);
1014         hdr->len  = __len8(sizeof(*mcc) + sizeof(*rpn));
1015
1016         mcc = (void *) ptr; ptr += sizeof(*mcc);
1017         mcc->type = __mcc_type(cr, RFCOMM_RPN);
1018         mcc->len  = __len8(sizeof(*rpn));
1019
1020         rpn = (void *) ptr; ptr += sizeof(*rpn);
1021         rpn->dlci          = __addr(1, dlci);
1022         rpn->bit_rate      = bit_rate;
1023         rpn->line_settings = __rpn_line_settings(data_bits, stop_bits, parity);
1024         rpn->flow_ctrl     = flow_ctrl_settings;
1025         rpn->xon_char      = xon_char;
1026         rpn->xoff_char     = xoff_char;
1027         rpn->param_mask    = cpu_to_le16(param_mask);
1028
1029         *ptr = __fcs(buf); ptr++;
1030
1031         return rfcomm_send_frame(s, buf, ptr - buf);
1032 }
1033
1034 static int rfcomm_send_rls(struct rfcomm_session *s, int cr, u8 dlci, u8 status)
1035 {
1036         struct rfcomm_hdr *hdr;
1037         struct rfcomm_mcc *mcc;
1038         struct rfcomm_rls *rls;
1039         u8 buf[16], *ptr = buf;
1040
1041         BT_DBG("%p cr %d status 0x%x", s, cr, status);
1042
1043         hdr = (void *) ptr; ptr += sizeof(*hdr);
1044         hdr->addr = __addr(s->initiator, 0);
1045         hdr->ctrl = __ctrl(RFCOMM_UIH, 0);
1046         hdr->len  = __len8(sizeof(*mcc) + sizeof(*rls));
1047
1048         mcc = (void *) ptr; ptr += sizeof(*mcc);
1049         mcc->type = __mcc_type(cr, RFCOMM_RLS);
1050         mcc->len  = __len8(sizeof(*rls));
1051
1052         rls = (void *) ptr; ptr += sizeof(*rls);
1053         rls->dlci   = __addr(1, dlci);
1054         rls->status = status;
1055
1056         *ptr = __fcs(buf); ptr++;
1057
1058         return rfcomm_send_frame(s, buf, ptr - buf);
1059 }
1060
1061 static int rfcomm_send_msc(struct rfcomm_session *s, int cr, u8 dlci, u8 v24_sig)
1062 {
1063         struct rfcomm_hdr *hdr;
1064         struct rfcomm_mcc *mcc;
1065         struct rfcomm_msc *msc;
1066         u8 buf[16], *ptr = buf;
1067
1068         BT_DBG("%p cr %d v24 0x%x", s, cr, v24_sig);
1069
1070         hdr = (void *) ptr; ptr += sizeof(*hdr);
1071         hdr->addr = __addr(s->initiator, 0);
1072         hdr->ctrl = __ctrl(RFCOMM_UIH, 0);
1073         hdr->len  = __len8(sizeof(*mcc) + sizeof(*msc));
1074
1075         mcc = (void *) ptr; ptr += sizeof(*mcc);
1076         mcc->type = __mcc_type(cr, RFCOMM_MSC);
1077         mcc->len  = __len8(sizeof(*msc));
1078
1079         msc = (void *) ptr; ptr += sizeof(*msc);
1080         msc->dlci    = __addr(1, dlci);
1081         msc->v24_sig = v24_sig | 0x01;
1082
1083         *ptr = __fcs(buf); ptr++;
1084
1085         return rfcomm_send_frame(s, buf, ptr - buf);
1086 }
1087
1088 static int rfcomm_send_fcoff(struct rfcomm_session *s, int cr)
1089 {
1090         struct rfcomm_hdr *hdr;
1091         struct rfcomm_mcc *mcc;
1092         u8 buf[16], *ptr = buf;
1093
1094         BT_DBG("%p cr %d", s, cr);
1095
1096         hdr = (void *) ptr; ptr += sizeof(*hdr);
1097         hdr->addr = __addr(s->initiator, 0);
1098         hdr->ctrl = __ctrl(RFCOMM_UIH, 0);
1099         hdr->len  = __len8(sizeof(*mcc));
1100
1101         mcc = (void *) ptr; ptr += sizeof(*mcc);
1102         mcc->type = __mcc_type(cr, RFCOMM_FCOFF);
1103         mcc->len  = __len8(0);
1104
1105         *ptr = __fcs(buf); ptr++;
1106
1107         return rfcomm_send_frame(s, buf, ptr - buf);
1108 }
1109
1110 static int rfcomm_send_fcon(struct rfcomm_session *s, int cr)
1111 {
1112         struct rfcomm_hdr *hdr;
1113         struct rfcomm_mcc *mcc;
1114         u8 buf[16], *ptr = buf;
1115
1116         BT_DBG("%p cr %d", s, cr);
1117
1118         hdr = (void *) ptr; ptr += sizeof(*hdr);
1119         hdr->addr = __addr(s->initiator, 0);
1120         hdr->ctrl = __ctrl(RFCOMM_UIH, 0);
1121         hdr->len  = __len8(sizeof(*mcc));
1122
1123         mcc = (void *) ptr; ptr += sizeof(*mcc);
1124         mcc->type = __mcc_type(cr, RFCOMM_FCON);
1125         mcc->len  = __len8(0);
1126
1127         *ptr = __fcs(buf); ptr++;
1128
1129         return rfcomm_send_frame(s, buf, ptr - buf);
1130 }
1131
1132 static int rfcomm_send_test(struct rfcomm_session *s, int cr, u8 *pattern, int len)
1133 {
1134         struct socket *sock = s->sock;
1135         struct kvec iv[3];
1136         struct msghdr msg;
1137         unsigned char hdr[5], crc[1];
1138
1139         if (len > 125)
1140                 return -EINVAL;
1141
1142         BT_DBG("%p cr %d", s, cr);
1143
1144         hdr[0] = __addr(s->initiator, 0);
1145         hdr[1] = __ctrl(RFCOMM_UIH, 0);
1146         hdr[2] = 0x01 | ((len + 2) << 1);
1147         hdr[3] = 0x01 | ((cr & 0x01) << 1) | (RFCOMM_TEST << 2);
1148         hdr[4] = 0x01 | (len << 1);
1149
1150         crc[0] = __fcs(hdr);
1151
1152         iv[0].iov_base = hdr;
1153         iv[0].iov_len  = 5;
1154         iv[1].iov_base = pattern;
1155         iv[1].iov_len  = len;
1156         iv[2].iov_base = crc;
1157         iv[2].iov_len  = 1;
1158
1159         memset(&msg, 0, sizeof(msg));
1160
1161         return kernel_sendmsg(sock, &msg, iv, 3, 6 + len);
1162 }
1163
1164 static int rfcomm_send_credits(struct rfcomm_session *s, u8 addr, u8 credits)
1165 {
1166         struct rfcomm_hdr *hdr;
1167         u8 buf[16], *ptr = buf;
1168
1169         BT_DBG("%p addr %d credits %d", s, addr, credits);
1170
1171         hdr = (void *) ptr; ptr += sizeof(*hdr);
1172         hdr->addr = addr;
1173         hdr->ctrl = __ctrl(RFCOMM_UIH, 1);
1174         hdr->len  = __len8(0);
1175
1176         *ptr = credits; ptr++;
1177
1178         *ptr = __fcs(buf); ptr++;
1179
1180         return rfcomm_send_frame(s, buf, ptr - buf);
1181 }
1182
1183 static void rfcomm_make_uih(struct sk_buff *skb, u8 addr)
1184 {
1185         struct rfcomm_hdr *hdr;
1186         int len = skb->len;
1187         u8 *crc;
1188
1189         if (len > 127) {
1190                 hdr = skb_push(skb, 4);
1191                 put_unaligned(cpu_to_le16(__len16(len)), (__le16 *) &hdr->len);
1192         } else {
1193                 hdr = skb_push(skb, 3);
1194                 hdr->len = __len8(len);
1195         }
1196         hdr->addr = addr;
1197         hdr->ctrl = __ctrl(RFCOMM_UIH, 0);
1198
1199         crc = skb_put(skb, 1);
1200         *crc = __fcs((void *) hdr);
1201 }
1202
1203 /* ---- RFCOMM frame reception ---- */
1204 static struct rfcomm_session *rfcomm_recv_ua(struct rfcomm_session *s, u8 dlci)
1205 {
1206         BT_DBG("session %p state %ld dlci %d", s, s->state, dlci);
1207
1208         if (dlci) {
1209                 /* Data channel */
1210                 struct rfcomm_dlc *d = rfcomm_dlc_get(s, dlci);
1211                 if (!d) {
1212                         rfcomm_send_dm(s, dlci);
1213                         return s;
1214                 }
1215
1216                 switch (d->state) {
1217                 case BT_CONNECT:
1218                         rfcomm_dlc_clear_timer(d);
1219
1220                         rfcomm_dlc_lock(d);
1221                         d->state = BT_CONNECTED;
1222                         d->state_change(d, 0);
1223                         rfcomm_dlc_unlock(d);
1224
1225                         rfcomm_send_msc(s, 1, dlci, d->v24_sig);
1226                         break;
1227
1228                 case BT_DISCONN:
1229                         d->state = BT_CLOSED;
1230                         __rfcomm_dlc_close(d, 0);
1231
1232                         if (list_empty(&s->dlcs)) {
1233                                 s->state = BT_DISCONN;
1234                                 rfcomm_send_disc(s, 0);
1235                                 rfcomm_session_clear_timer(s);
1236                         }
1237
1238                         break;
1239                 }
1240         } else {
1241                 /* Control channel */
1242                 switch (s->state) {
1243                 case BT_CONNECT:
1244                         s->state = BT_CONNECTED;
1245                         rfcomm_process_connect(s);
1246                         break;
1247
1248                 case BT_DISCONN:
1249                         s = rfcomm_session_close(s, ECONNRESET);
1250                         break;
1251                 }
1252         }
1253         return s;
1254 }
1255
1256 static struct rfcomm_session *rfcomm_recv_dm(struct rfcomm_session *s, u8 dlci)
1257 {
1258         int err = 0;
1259
1260         BT_DBG("session %p state %ld dlci %d", s, s->state, dlci);
1261
1262         if (dlci) {
1263                 /* Data DLC */
1264                 struct rfcomm_dlc *d = rfcomm_dlc_get(s, dlci);
1265                 if (d) {
1266                         if (d->state == BT_CONNECT || d->state == BT_CONFIG)
1267                                 err = ECONNREFUSED;
1268                         else
1269                                 err = ECONNRESET;
1270
1271                         d->state = BT_CLOSED;
1272                         __rfcomm_dlc_close(d, err);
1273                 }
1274         } else {
1275                 if (s->state == BT_CONNECT)
1276                         err = ECONNREFUSED;
1277                 else
1278                         err = ECONNRESET;
1279
1280                 s = rfcomm_session_close(s, err);
1281         }
1282         return s;
1283 }
1284
1285 static struct rfcomm_session *rfcomm_recv_disc(struct rfcomm_session *s,
1286                                                u8 dlci)
1287 {
1288         int err = 0;
1289
1290         BT_DBG("session %p state %ld dlci %d", s, s->state, dlci);
1291
1292         if (dlci) {
1293                 struct rfcomm_dlc *d = rfcomm_dlc_get(s, dlci);
1294                 if (d) {
1295                         rfcomm_send_ua(s, dlci);
1296
1297                         if (d->state == BT_CONNECT || d->state == BT_CONFIG)
1298                                 err = ECONNREFUSED;
1299                         else
1300                                 err = ECONNRESET;
1301
1302                         d->state = BT_CLOSED;
1303                         __rfcomm_dlc_close(d, err);
1304                 } else
1305                         rfcomm_send_dm(s, dlci);
1306
1307         } else {
1308                 rfcomm_send_ua(s, 0);
1309
1310                 if (s->state == BT_CONNECT)
1311                         err = ECONNREFUSED;
1312                 else
1313                         err = ECONNRESET;
1314
1315                 s = rfcomm_session_close(s, err);
1316         }
1317         return s;
1318 }
1319
1320 void rfcomm_dlc_accept(struct rfcomm_dlc *d)
1321 {
1322         struct sock *sk = d->session->sock->sk;
1323         struct l2cap_conn *conn = l2cap_pi(sk)->chan->conn;
1324
1325         BT_DBG("dlc %p", d);
1326
1327         rfcomm_send_ua(d->session, d->dlci);
1328
1329         rfcomm_dlc_clear_timer(d);
1330
1331         rfcomm_dlc_lock(d);
1332         d->state = BT_CONNECTED;
1333         d->state_change(d, 0);
1334         rfcomm_dlc_unlock(d);
1335
1336         if (d->role_switch)
1337                 hci_conn_switch_role(conn->hcon, 0x00);
1338
1339         rfcomm_send_msc(d->session, 1, d->dlci, d->v24_sig);
1340 }
1341
1342 static void rfcomm_check_accept(struct rfcomm_dlc *d)
1343 {
1344         if (rfcomm_check_security(d)) {
1345                 if (d->defer_setup) {
1346                         set_bit(RFCOMM_DEFER_SETUP, &d->flags);
1347                         rfcomm_dlc_set_timer(d, RFCOMM_AUTH_TIMEOUT);
1348
1349                         rfcomm_dlc_lock(d);
1350                         d->state = BT_CONNECT2;
1351                         d->state_change(d, 0);
1352                         rfcomm_dlc_unlock(d);
1353                 } else
1354                         rfcomm_dlc_accept(d);
1355         } else {
1356                 set_bit(RFCOMM_AUTH_PENDING, &d->flags);
1357                 rfcomm_dlc_set_timer(d, RFCOMM_AUTH_TIMEOUT);
1358         }
1359 }
1360
1361 static int rfcomm_recv_sabm(struct rfcomm_session *s, u8 dlci)
1362 {
1363         struct rfcomm_dlc *d;
1364         u8 channel;
1365
1366         BT_DBG("session %p state %ld dlci %d", s, s->state, dlci);
1367
1368         if (!dlci) {
1369                 rfcomm_send_ua(s, 0);
1370
1371                 if (s->state == BT_OPEN) {
1372                         s->state = BT_CONNECTED;
1373                         rfcomm_process_connect(s);
1374                 }
1375                 return 0;
1376         }
1377
1378         /* Check if DLC exists */
1379         d = rfcomm_dlc_get(s, dlci);
1380         if (d) {
1381                 if (d->state == BT_OPEN) {
1382                         /* DLC was previously opened by PN request */
1383                         rfcomm_check_accept(d);
1384                 }
1385                 return 0;
1386         }
1387
1388         /* Notify socket layer about incoming connection */
1389         channel = __srv_channel(dlci);
1390         if (rfcomm_connect_ind(s, channel, &d)) {
1391                 d->dlci = dlci;
1392                 d->addr = __addr(s->initiator, dlci);
1393                 rfcomm_dlc_link(s, d);
1394
1395                 rfcomm_check_accept(d);
1396         } else {
1397                 rfcomm_send_dm(s, dlci);
1398         }
1399
1400         return 0;
1401 }
1402
1403 static int rfcomm_apply_pn(struct rfcomm_dlc *d, int cr, struct rfcomm_pn *pn)
1404 {
1405         struct rfcomm_session *s = d->session;
1406
1407         BT_DBG("dlc %p state %ld dlci %d mtu %d fc 0x%x credits %d",
1408                         d, d->state, d->dlci, pn->mtu, pn->flow_ctrl, pn->credits);
1409
1410         if ((pn->flow_ctrl == 0xf0 && s->cfc != RFCOMM_CFC_DISABLED) ||
1411                                                 pn->flow_ctrl == 0xe0) {
1412                 d->cfc = RFCOMM_CFC_ENABLED;
1413                 d->tx_credits = pn->credits;
1414         } else {
1415                 d->cfc = RFCOMM_CFC_DISABLED;
1416                 set_bit(RFCOMM_TX_THROTTLED, &d->flags);
1417         }
1418
1419         if (s->cfc == RFCOMM_CFC_UNKNOWN)
1420                 s->cfc = d->cfc;
1421
1422         d->priority = pn->priority;
1423
1424         d->mtu = __le16_to_cpu(pn->mtu);
1425
1426         if (cr && d->mtu > s->mtu)
1427                 d->mtu = s->mtu;
1428
1429         return 0;
1430 }
1431
1432 static int rfcomm_recv_pn(struct rfcomm_session *s, int cr, struct sk_buff *skb)
1433 {
1434         struct rfcomm_pn *pn = (void *) skb->data;
1435         struct rfcomm_dlc *d;
1436         u8 dlci = pn->dlci;
1437
1438         BT_DBG("session %p state %ld dlci %d", s, s->state, dlci);
1439
1440         if (!dlci)
1441                 return 0;
1442
1443         d = rfcomm_dlc_get(s, dlci);
1444         if (d) {
1445                 if (cr) {
1446                         /* PN request */
1447                         rfcomm_apply_pn(d, cr, pn);
1448                         rfcomm_send_pn(s, 0, d);
1449                 } else {
1450                         /* PN response */
1451                         switch (d->state) {
1452                         case BT_CONFIG:
1453                                 rfcomm_apply_pn(d, cr, pn);
1454
1455                                 d->state = BT_CONNECT;
1456                                 rfcomm_send_sabm(s, d->dlci);
1457                                 break;
1458                         }
1459                 }
1460         } else {
1461                 u8 channel = __srv_channel(dlci);
1462
1463                 if (!cr)
1464                         return 0;
1465
1466                 /* PN request for non existing DLC.
1467                  * Assume incoming connection. */
1468                 if (rfcomm_connect_ind(s, channel, &d)) {
1469                         d->dlci = dlci;
1470                         d->addr = __addr(s->initiator, dlci);
1471                         rfcomm_dlc_link(s, d);
1472
1473                         rfcomm_apply_pn(d, cr, pn);
1474
1475                         d->state = BT_OPEN;
1476                         rfcomm_send_pn(s, 0, d);
1477                 } else {
1478                         rfcomm_send_dm(s, dlci);
1479                 }
1480         }
1481         return 0;
1482 }
1483
1484 static int rfcomm_recv_rpn(struct rfcomm_session *s, int cr, int len, struct sk_buff *skb)
1485 {
1486         struct rfcomm_rpn *rpn = (void *) skb->data;
1487         u8 dlci = __get_dlci(rpn->dlci);
1488
1489         u8 bit_rate  = 0;
1490         u8 data_bits = 0;
1491         u8 stop_bits = 0;
1492         u8 parity    = 0;
1493         u8 flow_ctrl = 0;
1494         u8 xon_char  = 0;
1495         u8 xoff_char = 0;
1496         u16 rpn_mask = RFCOMM_RPN_PM_ALL;
1497
1498         BT_DBG("dlci %d cr %d len 0x%x bitr 0x%x line 0x%x flow 0x%x xonc 0x%x xoffc 0x%x pm 0x%x",
1499                 dlci, cr, len, rpn->bit_rate, rpn->line_settings, rpn->flow_ctrl,
1500                 rpn->xon_char, rpn->xoff_char, rpn->param_mask);
1501
1502         if (!cr)
1503                 return 0;
1504
1505         if (len == 1) {
1506                 /* This is a request, return default (according to ETSI TS 07.10) settings */
1507                 bit_rate  = RFCOMM_RPN_BR_9600;
1508                 data_bits = RFCOMM_RPN_DATA_8;
1509                 stop_bits = RFCOMM_RPN_STOP_1;
1510                 parity    = RFCOMM_RPN_PARITY_NONE;
1511                 flow_ctrl = RFCOMM_RPN_FLOW_NONE;
1512                 xon_char  = RFCOMM_RPN_XON_CHAR;
1513                 xoff_char = RFCOMM_RPN_XOFF_CHAR;
1514                 goto rpn_out;
1515         }
1516
1517         /* Check for sane values, ignore/accept bit_rate, 8 bits, 1 stop bit,
1518          * no parity, no flow control lines, normal XON/XOFF chars */
1519
1520         if (rpn->param_mask & cpu_to_le16(RFCOMM_RPN_PM_BITRATE)) {
1521                 bit_rate = rpn->bit_rate;
1522                 if (bit_rate > RFCOMM_RPN_BR_230400) {
1523                         BT_DBG("RPN bit rate mismatch 0x%x", bit_rate);
1524                         bit_rate = RFCOMM_RPN_BR_9600;
1525                         rpn_mask ^= RFCOMM_RPN_PM_BITRATE;
1526                 }
1527         }
1528
1529         if (rpn->param_mask & cpu_to_le16(RFCOMM_RPN_PM_DATA)) {
1530                 data_bits = __get_rpn_data_bits(rpn->line_settings);
1531                 if (data_bits != RFCOMM_RPN_DATA_8) {
1532                         BT_DBG("RPN data bits mismatch 0x%x", data_bits);
1533                         data_bits = RFCOMM_RPN_DATA_8;
1534                         rpn_mask ^= RFCOMM_RPN_PM_DATA;
1535                 }
1536         }
1537
1538         if (rpn->param_mask & cpu_to_le16(RFCOMM_RPN_PM_STOP)) {
1539                 stop_bits = __get_rpn_stop_bits(rpn->line_settings);
1540                 if (stop_bits != RFCOMM_RPN_STOP_1) {
1541                         BT_DBG("RPN stop bits mismatch 0x%x", stop_bits);
1542                         stop_bits = RFCOMM_RPN_STOP_1;
1543                         rpn_mask ^= RFCOMM_RPN_PM_STOP;
1544                 }
1545         }
1546
1547         if (rpn->param_mask & cpu_to_le16(RFCOMM_RPN_PM_PARITY)) {
1548                 parity = __get_rpn_parity(rpn->line_settings);
1549                 if (parity != RFCOMM_RPN_PARITY_NONE) {
1550                         BT_DBG("RPN parity mismatch 0x%x", parity);
1551                         parity = RFCOMM_RPN_PARITY_NONE;
1552                         rpn_mask ^= RFCOMM_RPN_PM_PARITY;
1553                 }
1554         }
1555
1556         if (rpn->param_mask & cpu_to_le16(RFCOMM_RPN_PM_FLOW)) {
1557                 flow_ctrl = rpn->flow_ctrl;
1558                 if (flow_ctrl != RFCOMM_RPN_FLOW_NONE) {
1559                         BT_DBG("RPN flow ctrl mismatch 0x%x", flow_ctrl);
1560                         flow_ctrl = RFCOMM_RPN_FLOW_NONE;
1561                         rpn_mask ^= RFCOMM_RPN_PM_FLOW;
1562                 }
1563         }
1564
1565         if (rpn->param_mask & cpu_to_le16(RFCOMM_RPN_PM_XON)) {
1566                 xon_char = rpn->xon_char;
1567                 if (xon_char != RFCOMM_RPN_XON_CHAR) {
1568                         BT_DBG("RPN XON char mismatch 0x%x", xon_char);
1569                         xon_char = RFCOMM_RPN_XON_CHAR;
1570                         rpn_mask ^= RFCOMM_RPN_PM_XON;
1571                 }
1572         }
1573
1574         if (rpn->param_mask & cpu_to_le16(RFCOMM_RPN_PM_XOFF)) {
1575                 xoff_char = rpn->xoff_char;
1576                 if (xoff_char != RFCOMM_RPN_XOFF_CHAR) {
1577                         BT_DBG("RPN XOFF char mismatch 0x%x", xoff_char);
1578                         xoff_char = RFCOMM_RPN_XOFF_CHAR;
1579                         rpn_mask ^= RFCOMM_RPN_PM_XOFF;
1580                 }
1581         }
1582
1583 rpn_out:
1584         rfcomm_send_rpn(s, 0, dlci, bit_rate, data_bits, stop_bits,
1585                         parity, flow_ctrl, xon_char, xoff_char, rpn_mask);
1586
1587         return 0;
1588 }
1589
1590 static int rfcomm_recv_rls(struct rfcomm_session *s, int cr, struct sk_buff *skb)
1591 {
1592         struct rfcomm_rls *rls = (void *) skb->data;
1593         u8 dlci = __get_dlci(rls->dlci);
1594
1595         BT_DBG("dlci %d cr %d status 0x%x", dlci, cr, rls->status);
1596
1597         if (!cr)
1598                 return 0;
1599
1600         /* We should probably do something with this information here. But
1601          * for now it's sufficient just to reply -- Bluetooth 1.1 says it's
1602          * mandatory to recognise and respond to RLS */
1603
1604         rfcomm_send_rls(s, 0, dlci, rls->status);
1605
1606         return 0;
1607 }
1608
1609 static int rfcomm_recv_msc(struct rfcomm_session *s, int cr, struct sk_buff *skb)
1610 {
1611         struct rfcomm_msc *msc = (void *) skb->data;
1612         struct rfcomm_dlc *d;
1613         u8 dlci = __get_dlci(msc->dlci);
1614
1615         BT_DBG("dlci %d cr %d v24 0x%x", dlci, cr, msc->v24_sig);
1616
1617         d = rfcomm_dlc_get(s, dlci);
1618         if (!d)
1619                 return 0;
1620
1621         if (cr) {
1622                 if (msc->v24_sig & RFCOMM_V24_FC && !d->cfc)
1623                         set_bit(RFCOMM_TX_THROTTLED, &d->flags);
1624                 else
1625                         clear_bit(RFCOMM_TX_THROTTLED, &d->flags);
1626
1627                 rfcomm_dlc_lock(d);
1628
1629                 d->remote_v24_sig = msc->v24_sig;
1630
1631                 if (d->modem_status)
1632                         d->modem_status(d, msc->v24_sig);
1633
1634                 rfcomm_dlc_unlock(d);
1635
1636                 rfcomm_send_msc(s, 0, dlci, msc->v24_sig);
1637
1638                 d->mscex |= RFCOMM_MSCEX_RX;
1639         } else
1640                 d->mscex |= RFCOMM_MSCEX_TX;
1641
1642         return 0;
1643 }
1644
1645 static int rfcomm_recv_mcc(struct rfcomm_session *s, struct sk_buff *skb)
1646 {
1647         struct rfcomm_mcc *mcc = (void *) skb->data;
1648         u8 type, cr, len;
1649
1650         cr   = __test_cr(mcc->type);
1651         type = __get_mcc_type(mcc->type);
1652         len  = __get_mcc_len(mcc->len);
1653
1654         BT_DBG("%p type 0x%x cr %d", s, type, cr);
1655
1656         skb_pull(skb, 2);
1657
1658         switch (type) {
1659         case RFCOMM_PN:
1660                 rfcomm_recv_pn(s, cr, skb);
1661                 break;
1662
1663         case RFCOMM_RPN:
1664                 rfcomm_recv_rpn(s, cr, len, skb);
1665                 break;
1666
1667         case RFCOMM_RLS:
1668                 rfcomm_recv_rls(s, cr, skb);
1669                 break;
1670
1671         case RFCOMM_MSC:
1672                 rfcomm_recv_msc(s, cr, skb);
1673                 break;
1674
1675         case RFCOMM_FCOFF:
1676                 if (cr) {
1677                         set_bit(RFCOMM_TX_THROTTLED, &s->flags);
1678                         rfcomm_send_fcoff(s, 0);
1679                 }
1680                 break;
1681
1682         case RFCOMM_FCON:
1683                 if (cr) {
1684                         clear_bit(RFCOMM_TX_THROTTLED, &s->flags);
1685                         rfcomm_send_fcon(s, 0);
1686                 }
1687                 break;
1688
1689         case RFCOMM_TEST:
1690                 if (cr)
1691                         rfcomm_send_test(s, 0, skb->data, skb->len);
1692                 break;
1693
1694         case RFCOMM_NSC:
1695                 break;
1696
1697         default:
1698                 BT_ERR("Unknown control type 0x%02x", type);
1699                 rfcomm_send_nsc(s, cr, type);
1700                 break;
1701         }
1702         return 0;
1703 }
1704
1705 static int rfcomm_recv_data(struct rfcomm_session *s, u8 dlci, int pf, struct sk_buff *skb)
1706 {
1707         struct rfcomm_dlc *d;
1708
1709         BT_DBG("session %p state %ld dlci %d pf %d", s, s->state, dlci, pf);
1710
1711         d = rfcomm_dlc_get(s, dlci);
1712         if (!d) {
1713                 rfcomm_send_dm(s, dlci);
1714                 goto drop;
1715         }
1716
1717         if (pf && d->cfc) {
1718                 u8 credits = *(u8 *) skb->data; skb_pull(skb, 1);
1719
1720                 d->tx_credits += credits;
1721                 if (d->tx_credits)
1722                         clear_bit(RFCOMM_TX_THROTTLED, &d->flags);
1723         }
1724
1725         if (skb->len && d->state == BT_CONNECTED) {
1726                 rfcomm_dlc_lock(d);
1727                 d->rx_credits--;
1728                 d->data_ready(d, skb);
1729                 rfcomm_dlc_unlock(d);
1730                 return 0;
1731         }
1732
1733 drop:
1734         kfree_skb(skb);
1735         return 0;
1736 }
1737
1738 static struct rfcomm_session *rfcomm_recv_frame(struct rfcomm_session *s,
1739                                                 struct sk_buff *skb)
1740 {
1741         struct rfcomm_hdr *hdr = (void *) skb->data;
1742         u8 type, dlci, fcs;
1743
1744         if (!s) {
1745                 /* no session, so free socket data */
1746                 kfree_skb(skb);
1747                 return s;
1748         }
1749
1750         dlci = __get_dlci(hdr->addr);
1751         type = __get_type(hdr->ctrl);
1752
1753         /* Trim FCS */
1754         skb->len--; skb->tail--;
1755         fcs = *(u8 *)skb_tail_pointer(skb);
1756
1757         if (__check_fcs(skb->data, type, fcs)) {
1758                 BT_ERR("bad checksum in packet");
1759                 kfree_skb(skb);
1760                 return s;
1761         }
1762
1763         if (__test_ea(hdr->len))
1764                 skb_pull(skb, 3);
1765         else
1766                 skb_pull(skb, 4);
1767
1768         switch (type) {
1769         case RFCOMM_SABM:
1770                 if (__test_pf(hdr->ctrl))
1771                         rfcomm_recv_sabm(s, dlci);
1772                 break;
1773
1774         case RFCOMM_DISC:
1775                 if (__test_pf(hdr->ctrl))
1776                         s = rfcomm_recv_disc(s, dlci);
1777                 break;
1778
1779         case RFCOMM_UA:
1780                 if (__test_pf(hdr->ctrl))
1781                         s = rfcomm_recv_ua(s, dlci);
1782                 break;
1783
1784         case RFCOMM_DM:
1785                 s = rfcomm_recv_dm(s, dlci);
1786                 break;
1787
1788         case RFCOMM_UIH:
1789                 if (dlci) {
1790                         rfcomm_recv_data(s, dlci, __test_pf(hdr->ctrl), skb);
1791                         return s;
1792                 }
1793                 rfcomm_recv_mcc(s, skb);
1794                 break;
1795
1796         default:
1797                 BT_ERR("Unknown packet type 0x%02x", type);
1798                 break;
1799         }
1800         kfree_skb(skb);
1801         return s;
1802 }
1803
1804 /* ---- Connection and data processing ---- */
1805
1806 static void rfcomm_process_connect(struct rfcomm_session *s)
1807 {
1808         struct rfcomm_dlc *d, *n;
1809
1810         BT_DBG("session %p state %ld", s, s->state);
1811
1812         list_for_each_entry_safe(d, n, &s->dlcs, list) {
1813                 if (d->state == BT_CONFIG) {
1814                         d->mtu = s->mtu;
1815                         if (rfcomm_check_security(d)) {
1816                                 rfcomm_send_pn(s, 1, d);
1817                         } else {
1818                                 set_bit(RFCOMM_AUTH_PENDING, &d->flags);
1819                                 rfcomm_dlc_set_timer(d, RFCOMM_AUTH_TIMEOUT);
1820                         }
1821                 }
1822         }
1823 }
1824
1825 /* Send data queued for the DLC.
1826  * Return number of frames left in the queue.
1827  */
1828 static int rfcomm_process_tx(struct rfcomm_dlc *d)
1829 {
1830         struct sk_buff *skb;
1831         int err;
1832
1833         BT_DBG("dlc %p state %ld cfc %d rx_credits %d tx_credits %d",
1834                         d, d->state, d->cfc, d->rx_credits, d->tx_credits);
1835
1836         /* Send pending MSC */
1837         if (test_and_clear_bit(RFCOMM_MSC_PENDING, &d->flags))
1838                 rfcomm_send_msc(d->session, 1, d->dlci, d->v24_sig);
1839
1840         if (d->cfc) {
1841                 /* CFC enabled.
1842                  * Give them some credits */
1843                 if (!test_bit(RFCOMM_RX_THROTTLED, &d->flags) &&
1844                                 d->rx_credits <= (d->cfc >> 2)) {
1845                         rfcomm_send_credits(d->session, d->addr, d->cfc - d->rx_credits);
1846                         d->rx_credits = d->cfc;
1847                 }
1848         } else {
1849                 /* CFC disabled.
1850                  * Give ourselves some credits */
1851                 d->tx_credits = 5;
1852         }
1853
1854         if (test_bit(RFCOMM_TX_THROTTLED, &d->flags))
1855                 return skb_queue_len(&d->tx_queue);
1856
1857         while (d->tx_credits && (skb = skb_dequeue(&d->tx_queue))) {
1858                 err = rfcomm_send_frame(d->session, skb->data, skb->len);
1859                 if (err < 0) {
1860                         skb_queue_head(&d->tx_queue, skb);
1861                         break;
1862                 }
1863                 kfree_skb(skb);
1864                 d->tx_credits--;
1865         }
1866
1867         if (d->cfc && !d->tx_credits) {
1868                 /* We're out of TX credits.
1869                  * Set TX_THROTTLED flag to avoid unnesary wakeups by dlc_send. */
1870                 set_bit(RFCOMM_TX_THROTTLED, &d->flags);
1871         }
1872
1873         return skb_queue_len(&d->tx_queue);
1874 }
1875
1876 static void rfcomm_process_dlcs(struct rfcomm_session *s)
1877 {
1878         struct rfcomm_dlc *d, *n;
1879
1880         BT_DBG("session %p state %ld", s, s->state);
1881
1882         list_for_each_entry_safe(d, n, &s->dlcs, list) {
1883                 if (test_bit(RFCOMM_TIMED_OUT, &d->flags)) {
1884                         __rfcomm_dlc_close(d, ETIMEDOUT);
1885                         continue;
1886                 }
1887
1888                 if (test_bit(RFCOMM_ENC_DROP, &d->flags)) {
1889                         __rfcomm_dlc_close(d, ECONNREFUSED);
1890                         continue;
1891                 }
1892
1893                 if (test_and_clear_bit(RFCOMM_AUTH_ACCEPT, &d->flags)) {
1894                         rfcomm_dlc_clear_timer(d);
1895                         if (d->out) {
1896                                 rfcomm_send_pn(s, 1, d);
1897                                 rfcomm_dlc_set_timer(d, RFCOMM_CONN_TIMEOUT);
1898                         } else {
1899                                 if (d->defer_setup) {
1900                                         set_bit(RFCOMM_DEFER_SETUP, &d->flags);
1901                                         rfcomm_dlc_set_timer(d, RFCOMM_AUTH_TIMEOUT);
1902
1903                                         rfcomm_dlc_lock(d);
1904                                         d->state = BT_CONNECT2;
1905                                         d->state_change(d, 0);
1906                                         rfcomm_dlc_unlock(d);
1907                                 } else
1908                                         rfcomm_dlc_accept(d);
1909                         }
1910                         continue;
1911                 } else if (test_and_clear_bit(RFCOMM_AUTH_REJECT, &d->flags)) {
1912                         rfcomm_dlc_clear_timer(d);
1913                         if (!d->out)
1914                                 rfcomm_send_dm(s, d->dlci);
1915                         else
1916                                 d->state = BT_CLOSED;
1917                         __rfcomm_dlc_close(d, ECONNREFUSED);
1918                         continue;
1919                 }
1920
1921                 if (test_bit(RFCOMM_SEC_PENDING, &d->flags))
1922                         continue;
1923
1924                 if (test_bit(RFCOMM_TX_THROTTLED, &s->flags))
1925                         continue;
1926
1927                 if ((d->state == BT_CONNECTED || d->state == BT_DISCONN) &&
1928                                                 d->mscex == RFCOMM_MSCEX_OK)
1929                         rfcomm_process_tx(d);
1930         }
1931 }
1932
1933 static struct rfcomm_session *rfcomm_process_rx(struct rfcomm_session *s)
1934 {
1935         struct socket *sock = s->sock;
1936         struct sock *sk = sock->sk;
1937         struct sk_buff *skb;
1938
1939         BT_DBG("session %p state %ld qlen %d", s, s->state, skb_queue_len(&sk->sk_receive_queue));
1940
1941         /* Get data directly from socket receive queue without copying it. */
1942         while ((skb = skb_dequeue(&sk->sk_receive_queue))) {
1943                 skb_orphan(skb);
1944                 if (!skb_linearize(skb)) {
1945                         s = rfcomm_recv_frame(s, skb);
1946                         if (!s)
1947                                 break;
1948                 } else {
1949                         kfree_skb(skb);
1950                 }
1951         }
1952
1953         if (s && (sk->sk_state == BT_CLOSED))
1954                 s = rfcomm_session_close(s, sk->sk_err);
1955
1956         return s;
1957 }
1958
1959 static void rfcomm_accept_connection(struct rfcomm_session *s)
1960 {
1961         struct socket *sock = s->sock, *nsock;
1962         int err;
1963
1964         /* Fast check for a new connection.
1965          * Avoids unnesesary socket allocations. */
1966         if (list_empty(&bt_sk(sock->sk)->accept_q))
1967                 return;
1968
1969         BT_DBG("session %p", s);
1970
1971         err = kernel_accept(sock, &nsock, O_NONBLOCK);
1972         if (err < 0)
1973                 return;
1974
1975         /* Set our callbacks */
1976         nsock->sk->sk_data_ready   = rfcomm_l2data_ready;
1977         nsock->sk->sk_state_change = rfcomm_l2state_change;
1978
1979         s = rfcomm_session_add(nsock, BT_OPEN);
1980         if (s) {
1981                 /* We should adjust MTU on incoming sessions.
1982                  * L2CAP MTU minus UIH header and FCS. */
1983                 s->mtu = min(l2cap_pi(nsock->sk)->chan->omtu,
1984                                 l2cap_pi(nsock->sk)->chan->imtu) - 5;
1985
1986                 rfcomm_schedule();
1987         } else
1988                 sock_release(nsock);
1989 }
1990
1991 static struct rfcomm_session *rfcomm_check_connection(struct rfcomm_session *s)
1992 {
1993         struct sock *sk = s->sock->sk;
1994
1995         BT_DBG("%p state %ld", s, s->state);
1996
1997         switch (sk->sk_state) {
1998         case BT_CONNECTED:
1999                 s->state = BT_CONNECT;
2000
2001                 /* We can adjust MTU on outgoing sessions.
2002                  * L2CAP MTU minus UIH header and FCS. */
2003                 s->mtu = min(l2cap_pi(sk)->chan->omtu, l2cap_pi(sk)->chan->imtu) - 5;
2004
2005                 rfcomm_send_sabm(s, 0);
2006                 break;
2007
2008         case BT_CLOSED:
2009                 s = rfcomm_session_close(s, sk->sk_err);
2010                 break;
2011         }
2012         return s;
2013 }
2014
2015 static void rfcomm_process_sessions(void)
2016 {
2017         struct rfcomm_session *s, *n;
2018
2019         rfcomm_lock();
2020
2021         list_for_each_entry_safe(s, n, &session_list, list) {
2022                 if (test_and_clear_bit(RFCOMM_TIMED_OUT, &s->flags)) {
2023                         s->state = BT_DISCONN;
2024                         rfcomm_send_disc(s, 0);
2025                         continue;
2026                 }
2027
2028                 switch (s->state) {
2029                 case BT_LISTEN:
2030                         rfcomm_accept_connection(s);
2031                         continue;
2032
2033                 case BT_BOUND:
2034                         s = rfcomm_check_connection(s);
2035                         break;
2036
2037                 default:
2038                         s = rfcomm_process_rx(s);
2039                         break;
2040                 }
2041
2042                 if (s)
2043                         rfcomm_process_dlcs(s);
2044         }
2045
2046         rfcomm_unlock();
2047 }
2048
2049 static int rfcomm_add_listener(bdaddr_t *ba)
2050 {
2051         struct sockaddr_l2 addr;
2052         struct socket *sock;
2053         struct sock *sk;
2054         struct rfcomm_session *s;
2055         int    err = 0;
2056
2057         /* Create socket */
2058         err = rfcomm_l2sock_create(&sock);
2059         if (err < 0) {
2060                 BT_ERR("Create socket failed %d", err);
2061                 return err;
2062         }
2063
2064         /* Bind socket */
2065         bacpy(&addr.l2_bdaddr, ba);
2066         addr.l2_family = AF_BLUETOOTH;
2067         addr.l2_psm    = cpu_to_le16(L2CAP_PSM_RFCOMM);
2068         addr.l2_cid    = 0;
2069         addr.l2_bdaddr_type = BDADDR_BREDR;
2070         err = kernel_bind(sock, (struct sockaddr *) &addr, sizeof(addr));
2071         if (err < 0) {
2072                 BT_ERR("Bind failed %d", err);
2073                 goto failed;
2074         }
2075
2076         /* Set L2CAP options */
2077         sk = sock->sk;
2078         lock_sock(sk);
2079         /* Set MTU to 0 so L2CAP can auto select the MTU */
2080         l2cap_pi(sk)->chan->imtu = 0;
2081         release_sock(sk);
2082
2083         /* Start listening on the socket */
2084         err = kernel_listen(sock, 10);
2085         if (err) {
2086                 BT_ERR("Listen failed %d", err);
2087                 goto failed;
2088         }
2089
2090         /* Add listening session */
2091         s = rfcomm_session_add(sock, BT_LISTEN);
2092         if (!s) {
2093                 err = -ENOMEM;
2094                 goto failed;
2095         }
2096
2097         return 0;
2098 failed:
2099         sock_release(sock);
2100         return err;
2101 }
2102
2103 static void rfcomm_kill_listener(void)
2104 {
2105         struct rfcomm_session *s, *n;
2106
2107         BT_DBG("");
2108
2109         list_for_each_entry_safe(s, n, &session_list, list)
2110                 rfcomm_session_del(s);
2111 }
2112
2113 static int rfcomm_run(void *unused)
2114 {
2115         DEFINE_WAIT_FUNC(wait, woken_wake_function);
2116         BT_DBG("");
2117
2118         set_user_nice(current, -10);
2119
2120         rfcomm_add_listener(BDADDR_ANY);
2121
2122         add_wait_queue(&rfcomm_wq, &wait);
2123         while (!kthread_should_stop()) {
2124
2125                 /* Process stuff */
2126                 rfcomm_process_sessions();
2127
2128                 wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
2129         }
2130         remove_wait_queue(&rfcomm_wq, &wait);
2131
2132         rfcomm_kill_listener();
2133
2134         return 0;
2135 }
2136
2137 static void rfcomm_security_cfm(struct hci_conn *conn, u8 status, u8 encrypt)
2138 {
2139         struct rfcomm_session *s;
2140         struct rfcomm_dlc *d, *n;
2141
2142         BT_DBG("conn %p status 0x%02x encrypt 0x%02x", conn, status, encrypt);
2143
2144         s = rfcomm_session_get(&conn->hdev->bdaddr, &conn->dst);
2145         if (!s)
2146                 return;
2147
2148         list_for_each_entry_safe(d, n, &s->dlcs, list) {
2149                 if (test_and_clear_bit(RFCOMM_SEC_PENDING, &d->flags)) {
2150                         rfcomm_dlc_clear_timer(d);
2151                         if (status || encrypt == 0x00) {
2152                                 set_bit(RFCOMM_ENC_DROP, &d->flags);
2153                                 continue;
2154                         }
2155                 }
2156
2157                 if (d->state == BT_CONNECTED && !status && encrypt == 0x00) {
2158                         if (d->sec_level == BT_SECURITY_MEDIUM) {
2159                                 set_bit(RFCOMM_SEC_PENDING, &d->flags);
2160                                 rfcomm_dlc_set_timer(d, RFCOMM_AUTH_TIMEOUT);
2161                                 continue;
2162                         } else if (d->sec_level == BT_SECURITY_HIGH ||
2163                                    d->sec_level == BT_SECURITY_FIPS) {
2164                                 set_bit(RFCOMM_ENC_DROP, &d->flags);
2165                                 continue;
2166                         }
2167                 }
2168
2169                 if (!test_and_clear_bit(RFCOMM_AUTH_PENDING, &d->flags))
2170                         continue;
2171
2172                 if (!status && hci_conn_check_secure(conn, d->sec_level))
2173                         set_bit(RFCOMM_AUTH_ACCEPT, &d->flags);
2174                 else
2175                         set_bit(RFCOMM_AUTH_REJECT, &d->flags);
2176         }
2177
2178         rfcomm_schedule();
2179 }
2180
2181 static struct hci_cb rfcomm_cb = {
2182         .name           = "RFCOMM",
2183         .security_cfm   = rfcomm_security_cfm
2184 };
2185
2186 static int rfcomm_dlc_debugfs_show(struct seq_file *f, void *x)
2187 {
2188         struct rfcomm_session *s;
2189
2190         rfcomm_lock();
2191
2192         list_for_each_entry(s, &session_list, list) {
2193                 struct l2cap_chan *chan = l2cap_pi(s->sock->sk)->chan;
2194                 struct rfcomm_dlc *d;
2195                 list_for_each_entry(d, &s->dlcs, list) {
2196                         seq_printf(f, "%pMR %pMR %ld %d %d %d %d\n",
2197                                    &chan->src, &chan->dst,
2198                                    d->state, d->dlci, d->mtu,
2199                                    d->rx_credits, d->tx_credits);
2200                 }
2201         }
2202
2203         rfcomm_unlock();
2204
2205         return 0;
2206 }
2207
2208 DEFINE_SHOW_ATTRIBUTE(rfcomm_dlc_debugfs);
2209
2210 static struct dentry *rfcomm_dlc_debugfs;
2211
2212 /* ---- Initialization ---- */
2213 static int __init rfcomm_init(void)
2214 {
2215         int err;
2216
2217         hci_register_cb(&rfcomm_cb);
2218
2219         rfcomm_thread = kthread_run(rfcomm_run, NULL, "krfcommd");
2220         if (IS_ERR(rfcomm_thread)) {
2221                 err = PTR_ERR(rfcomm_thread);
2222                 goto unregister;
2223         }
2224
2225         err = rfcomm_init_ttys();
2226         if (err < 0)
2227                 goto stop;
2228
2229         err = rfcomm_init_sockets();
2230         if (err < 0)
2231                 goto cleanup;
2232
2233         BT_INFO("RFCOMM ver %s", VERSION);
2234
2235         if (IS_ERR_OR_NULL(bt_debugfs))
2236                 return 0;
2237
2238         rfcomm_dlc_debugfs = debugfs_create_file("rfcomm_dlc", 0444,
2239                                                  bt_debugfs, NULL,
2240                                                  &rfcomm_dlc_debugfs_fops);
2241
2242         return 0;
2243
2244 cleanup:
2245         rfcomm_cleanup_ttys();
2246
2247 stop:
2248         kthread_stop(rfcomm_thread);
2249
2250 unregister:
2251         hci_unregister_cb(&rfcomm_cb);
2252
2253         return err;
2254 }
2255
2256 static void __exit rfcomm_exit(void)
2257 {
2258         debugfs_remove(rfcomm_dlc_debugfs);
2259
2260         hci_unregister_cb(&rfcomm_cb);
2261
2262         kthread_stop(rfcomm_thread);
2263
2264         rfcomm_cleanup_ttys();
2265
2266         rfcomm_cleanup_sockets();
2267 }
2268
2269 module_init(rfcomm_init);
2270 module_exit(rfcomm_exit);
2271
2272 module_param(disable_cfc, bool, 0644);
2273 MODULE_PARM_DESC(disable_cfc, "Disable credit based flow control");
2274
2275 module_param(channel_mtu, int, 0644);
2276 MODULE_PARM_DESC(channel_mtu, "Default MTU for the RFCOMM channel");
2277
2278 module_param(l2cap_ertm, bool, 0644);
2279 MODULE_PARM_DESC(l2cap_ertm, "Use L2CAP ERTM mode for connection");
2280
2281 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
2282 MODULE_DESCRIPTION("Bluetooth RFCOMM ver " VERSION);
2283 MODULE_VERSION(VERSION);
2284 MODULE_LICENSE("GPL");
2285 MODULE_ALIAS("bt-proto-3");