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 8 Written 2000,2001 by Maxim Krasnyansky <maxk@qualcomm.com> 9 10 This program is free software; you can redistribute it and/or modify 11 it under the terms of the GNU General Public License version 2 as 12 published by the Free Software Foundation; 13 14 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 15 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 16 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. 17 IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY 18 CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES 19 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 20 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 21 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 22 23 ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS, 24 COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS 25 SOFTWARE IS DISCLAIMED. 26 */ 27 28 /* Bluetooth L2CAP sockets. */ 29 30 #include <linux/module.h> 31 #include <linux/export.h> 32 #include <linux/filter.h> 33 #include <linux/sched/signal.h> 34 35 #include <net/bluetooth/bluetooth.h> 36 #include <net/bluetooth/hci_core.h> 37 #include <net/bluetooth/l2cap.h> 38 39 #include "smp.h" 40 41 static struct bt_sock_list l2cap_sk_list = { 42 .lock = __RW_LOCK_UNLOCKED(l2cap_sk_list.lock) 43 }; 44 45 static const struct proto_ops l2cap_sock_ops; 46 static void l2cap_sock_init(struct sock *sk, struct sock *parent); 47 static struct sock *l2cap_sock_alloc(struct net *net, struct socket *sock, 48 int proto, gfp_t prio, int kern); 49 static void l2cap_sock_cleanup_listen(struct sock *parent); 50 51 bool l2cap_is_socket(struct socket *sock) 52 { 53 return sock && sock->ops == &l2cap_sock_ops; 54 } 55 EXPORT_SYMBOL(l2cap_is_socket); 56 57 static int l2cap_validate_bredr_psm(u16 psm) 58 { 59 /* PSM must be odd and lsb of upper byte must be 0 */ 60 if ((psm & 0x0101) != 0x0001) 61 return -EINVAL; 62 63 /* Restrict usage of well-known PSMs */ 64 if (psm < L2CAP_PSM_DYN_START && !capable(CAP_NET_BIND_SERVICE)) 65 return -EACCES; 66 67 return 0; 68 } 69 70 static int l2cap_validate_le_psm(u16 psm) 71 { 72 /* Valid LE_PSM ranges are defined only until 0x00ff */ 73 if (psm > L2CAP_PSM_LE_DYN_END) 74 return -EINVAL; 75 76 /* Restrict fixed, SIG assigned PSM values to CAP_NET_BIND_SERVICE */ 77 if (psm < L2CAP_PSM_LE_DYN_START && !capable(CAP_NET_BIND_SERVICE)) 78 return -EACCES; 79 80 return 0; 81 } 82 83 static int l2cap_sock_bind(struct socket *sock, struct sockaddr *addr, int alen) 84 { 85 struct sock *sk = sock->sk; 86 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 87 struct sockaddr_l2 la; 88 int len, err = 0; 89 90 BT_DBG("sk %p", sk); 91 92 if (!addr || alen < offsetofend(struct sockaddr, sa_family) || 93 addr->sa_family != AF_BLUETOOTH) 94 return -EINVAL; 95 96 memset(&la, 0, sizeof(la)); 97 len = min_t(unsigned int, sizeof(la), alen); 98 memcpy(&la, addr, len); 99 100 if (la.l2_cid && la.l2_psm) 101 return -EINVAL; 102 103 if (!bdaddr_type_is_valid(la.l2_bdaddr_type)) 104 return -EINVAL; 105 106 if (bdaddr_type_is_le(la.l2_bdaddr_type)) { 107 /* We only allow ATT user space socket */ 108 if (la.l2_cid && 109 la.l2_cid != cpu_to_le16(L2CAP_CID_ATT)) 110 return -EINVAL; 111 } 112 113 lock_sock(sk); 114 115 if (sk->sk_state != BT_OPEN) { 116 err = -EBADFD; 117 goto done; 118 } 119 120 if (la.l2_psm) { 121 __u16 psm = __le16_to_cpu(la.l2_psm); 122 123 if (la.l2_bdaddr_type == BDADDR_BREDR) 124 err = l2cap_validate_bredr_psm(psm); 125 else 126 err = l2cap_validate_le_psm(psm); 127 128 if (err) 129 goto done; 130 } 131 132 bacpy(&chan->src, &la.l2_bdaddr); 133 chan->src_type = la.l2_bdaddr_type; 134 135 if (la.l2_cid) 136 err = l2cap_add_scid(chan, __le16_to_cpu(la.l2_cid)); 137 else 138 err = l2cap_add_psm(chan, &la.l2_bdaddr, la.l2_psm); 139 140 if (err < 0) 141 goto done; 142 143 switch (chan->chan_type) { 144 case L2CAP_CHAN_CONN_LESS: 145 if (__le16_to_cpu(la.l2_psm) == L2CAP_PSM_3DSP) 146 chan->sec_level = BT_SECURITY_SDP; 147 break; 148 case L2CAP_CHAN_CONN_ORIENTED: 149 if (__le16_to_cpu(la.l2_psm) == L2CAP_PSM_SDP || 150 __le16_to_cpu(la.l2_psm) == L2CAP_PSM_RFCOMM) 151 chan->sec_level = BT_SECURITY_SDP; 152 break; 153 case L2CAP_CHAN_RAW: 154 chan->sec_level = BT_SECURITY_SDP; 155 break; 156 case L2CAP_CHAN_FIXED: 157 /* Fixed channels default to the L2CAP core not holding a 158 * hci_conn reference for them. For fixed channels mapping to 159 * L2CAP sockets we do want to hold a reference so set the 160 * appropriate flag to request it. 161 */ 162 set_bit(FLAG_HOLD_HCI_CONN, &chan->flags); 163 break; 164 } 165 166 /* Use L2CAP_MODE_LE_FLOWCTL (CoC) in case of LE address and 167 * L2CAP_MODE_EXT_FLOWCTL (ECRED) has not been set. 168 */ 169 if (chan->psm && bdaddr_type_is_le(chan->src_type) && 170 chan->mode != L2CAP_MODE_EXT_FLOWCTL) 171 chan->mode = L2CAP_MODE_LE_FLOWCTL; 172 173 chan->state = BT_BOUND; 174 sk->sk_state = BT_BOUND; 175 176 done: 177 release_sock(sk); 178 return err; 179 } 180 181 static int l2cap_sock_connect(struct socket *sock, struct sockaddr *addr, 182 int alen, int flags) 183 { 184 struct sock *sk = sock->sk; 185 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 186 struct sockaddr_l2 la; 187 int len, err = 0; 188 bool zapped; 189 190 BT_DBG("sk %p", sk); 191 192 lock_sock(sk); 193 zapped = sock_flag(sk, SOCK_ZAPPED); 194 release_sock(sk); 195 196 if (zapped) 197 return -EINVAL; 198 199 if (!addr || alen < offsetofend(struct sockaddr, sa_family) || 200 addr->sa_family != AF_BLUETOOTH) 201 return -EINVAL; 202 203 memset(&la, 0, sizeof(la)); 204 len = min_t(unsigned int, sizeof(la), alen); 205 memcpy(&la, addr, len); 206 207 if (la.l2_cid && la.l2_psm) 208 return -EINVAL; 209 210 if (!bdaddr_type_is_valid(la.l2_bdaddr_type)) 211 return -EINVAL; 212 213 /* Check that the socket wasn't bound to something that 214 * conflicts with the address given to connect(). If chan->src 215 * is BDADDR_ANY it means bind() was never used, in which case 216 * chan->src_type and la.l2_bdaddr_type do not need to match. 217 */ 218 if (chan->src_type == BDADDR_BREDR && bacmp(&chan->src, BDADDR_ANY) && 219 bdaddr_type_is_le(la.l2_bdaddr_type)) { 220 /* Old user space versions will try to incorrectly bind 221 * the ATT socket using BDADDR_BREDR. We need to accept 222 * this and fix up the source address type only when 223 * both the source CID and destination CID indicate 224 * ATT. Anything else is an invalid combination. 225 */ 226 if (chan->scid != L2CAP_CID_ATT || 227 la.l2_cid != cpu_to_le16(L2CAP_CID_ATT)) 228 return -EINVAL; 229 230 /* We don't have the hdev available here to make a 231 * better decision on random vs public, but since all 232 * user space versions that exhibit this issue anyway do 233 * not support random local addresses assuming public 234 * here is good enough. 235 */ 236 chan->src_type = BDADDR_LE_PUBLIC; 237 } 238 239 if (chan->src_type != BDADDR_BREDR && la.l2_bdaddr_type == BDADDR_BREDR) 240 return -EINVAL; 241 242 if (bdaddr_type_is_le(la.l2_bdaddr_type)) { 243 /* We only allow ATT user space socket */ 244 if (la.l2_cid && 245 la.l2_cid != cpu_to_le16(L2CAP_CID_ATT)) 246 return -EINVAL; 247 } 248 249 /* Use L2CAP_MODE_LE_FLOWCTL (CoC) in case of LE address and 250 * L2CAP_MODE_EXT_FLOWCTL (ECRED) has not been set. 251 */ 252 if (chan->psm && bdaddr_type_is_le(chan->src_type) && 253 chan->mode != L2CAP_MODE_EXT_FLOWCTL) 254 chan->mode = L2CAP_MODE_LE_FLOWCTL; 255 256 err = l2cap_chan_connect(chan, la.l2_psm, __le16_to_cpu(la.l2_cid), 257 &la.l2_bdaddr, la.l2_bdaddr_type); 258 if (err) 259 return err; 260 261 lock_sock(sk); 262 263 err = bt_sock_wait_state(sk, BT_CONNECTED, 264 sock_sndtimeo(sk, flags & O_NONBLOCK)); 265 266 release_sock(sk); 267 268 return err; 269 } 270 271 static int l2cap_sock_listen(struct socket *sock, int backlog) 272 { 273 struct sock *sk = sock->sk; 274 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 275 int err = 0; 276 277 BT_DBG("sk %p backlog %d", sk, backlog); 278 279 lock_sock(sk); 280 281 if (sk->sk_state != BT_BOUND) { 282 err = -EBADFD; 283 goto done; 284 } 285 286 if (sk->sk_type != SOCK_SEQPACKET && sk->sk_type != SOCK_STREAM) { 287 err = -EINVAL; 288 goto done; 289 } 290 291 switch (chan->mode) { 292 case L2CAP_MODE_BASIC: 293 case L2CAP_MODE_LE_FLOWCTL: 294 break; 295 case L2CAP_MODE_EXT_FLOWCTL: 296 if (!enable_ecred) { 297 err = -EOPNOTSUPP; 298 goto done; 299 } 300 break; 301 case L2CAP_MODE_ERTM: 302 case L2CAP_MODE_STREAMING: 303 if (!disable_ertm) 304 break; 305 fallthrough; 306 default: 307 err = -EOPNOTSUPP; 308 goto done; 309 } 310 311 sk->sk_max_ack_backlog = backlog; 312 sk->sk_ack_backlog = 0; 313 314 /* Listening channels need to use nested locking in order not to 315 * cause lockdep warnings when the created child channels end up 316 * being locked in the same thread as the parent channel. 317 */ 318 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT); 319 320 chan->state = BT_LISTEN; 321 sk->sk_state = BT_LISTEN; 322 323 done: 324 release_sock(sk); 325 return err; 326 } 327 328 static int l2cap_sock_accept(struct socket *sock, struct socket *newsock, 329 int flags, bool kern) 330 { 331 DEFINE_WAIT_FUNC(wait, woken_wake_function); 332 struct sock *sk = sock->sk, *nsk; 333 long timeo; 334 int err = 0; 335 336 lock_sock_nested(sk, L2CAP_NESTING_PARENT); 337 338 timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK); 339 340 BT_DBG("sk %p timeo %ld", sk, timeo); 341 342 /* Wait for an incoming connection. (wake-one). */ 343 add_wait_queue_exclusive(sk_sleep(sk), &wait); 344 while (1) { 345 if (sk->sk_state != BT_LISTEN) { 346 err = -EBADFD; 347 break; 348 } 349 350 nsk = bt_accept_dequeue(sk, newsock); 351 if (nsk) 352 break; 353 354 if (!timeo) { 355 err = -EAGAIN; 356 break; 357 } 358 359 if (signal_pending(current)) { 360 err = sock_intr_errno(timeo); 361 break; 362 } 363 364 release_sock(sk); 365 366 timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo); 367 368 lock_sock_nested(sk, L2CAP_NESTING_PARENT); 369 } 370 remove_wait_queue(sk_sleep(sk), &wait); 371 372 if (err) 373 goto done; 374 375 newsock->state = SS_CONNECTED; 376 377 BT_DBG("new socket %p", nsk); 378 379 done: 380 release_sock(sk); 381 return err; 382 } 383 384 static int l2cap_sock_getname(struct socket *sock, struct sockaddr *addr, 385 int peer) 386 { 387 struct sockaddr_l2 *la = (struct sockaddr_l2 *) addr; 388 struct sock *sk = sock->sk; 389 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 390 391 BT_DBG("sock %p, sk %p", sock, sk); 392 393 if (peer && sk->sk_state != BT_CONNECTED && 394 sk->sk_state != BT_CONNECT && sk->sk_state != BT_CONNECT2 && 395 sk->sk_state != BT_CONFIG) 396 return -ENOTCONN; 397 398 memset(la, 0, sizeof(struct sockaddr_l2)); 399 addr->sa_family = AF_BLUETOOTH; 400 401 la->l2_psm = chan->psm; 402 403 if (peer) { 404 bacpy(&la->l2_bdaddr, &chan->dst); 405 la->l2_cid = cpu_to_le16(chan->dcid); 406 la->l2_bdaddr_type = chan->dst_type; 407 } else { 408 bacpy(&la->l2_bdaddr, &chan->src); 409 la->l2_cid = cpu_to_le16(chan->scid); 410 la->l2_bdaddr_type = chan->src_type; 411 } 412 413 return sizeof(struct sockaddr_l2); 414 } 415 416 static int l2cap_get_mode(struct l2cap_chan *chan) 417 { 418 switch (chan->mode) { 419 case L2CAP_MODE_BASIC: 420 return BT_MODE_BASIC; 421 case L2CAP_MODE_ERTM: 422 return BT_MODE_ERTM; 423 case L2CAP_MODE_STREAMING: 424 return BT_MODE_STREAMING; 425 case L2CAP_MODE_LE_FLOWCTL: 426 return BT_MODE_LE_FLOWCTL; 427 case L2CAP_MODE_EXT_FLOWCTL: 428 return BT_MODE_EXT_FLOWCTL; 429 } 430 431 return -EINVAL; 432 } 433 434 static int l2cap_sock_getsockopt_old(struct socket *sock, int optname, 435 char __user *optval, int __user *optlen) 436 { 437 struct sock *sk = sock->sk; 438 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 439 struct l2cap_options opts; 440 struct l2cap_conninfo cinfo; 441 int err = 0; 442 size_t len; 443 u32 opt; 444 445 BT_DBG("sk %p", sk); 446 447 if (get_user(len, optlen)) 448 return -EFAULT; 449 450 lock_sock(sk); 451 452 switch (optname) { 453 case L2CAP_OPTIONS: 454 /* LE sockets should use BT_SNDMTU/BT_RCVMTU, but since 455 * legacy ATT code depends on getsockopt for 456 * L2CAP_OPTIONS we need to let this pass. 457 */ 458 if (bdaddr_type_is_le(chan->src_type) && 459 chan->scid != L2CAP_CID_ATT) { 460 err = -EINVAL; 461 break; 462 } 463 464 /* Only BR/EDR modes are supported here */ 465 switch (chan->mode) { 466 case L2CAP_MODE_BASIC: 467 case L2CAP_MODE_ERTM: 468 case L2CAP_MODE_STREAMING: 469 break; 470 default: 471 err = -EINVAL; 472 break; 473 } 474 475 if (err < 0) 476 break; 477 478 memset(&opts, 0, sizeof(opts)); 479 opts.imtu = chan->imtu; 480 opts.omtu = chan->omtu; 481 opts.flush_to = chan->flush_to; 482 opts.mode = chan->mode; 483 opts.fcs = chan->fcs; 484 opts.max_tx = chan->max_tx; 485 opts.txwin_size = chan->tx_win; 486 487 BT_DBG("mode 0x%2.2x", chan->mode); 488 489 len = min(len, sizeof(opts)); 490 if (copy_to_user(optval, (char *) &opts, len)) 491 err = -EFAULT; 492 493 break; 494 495 case L2CAP_LM: 496 switch (chan->sec_level) { 497 case BT_SECURITY_LOW: 498 opt = L2CAP_LM_AUTH; 499 break; 500 case BT_SECURITY_MEDIUM: 501 opt = L2CAP_LM_AUTH | L2CAP_LM_ENCRYPT; 502 break; 503 case BT_SECURITY_HIGH: 504 opt = L2CAP_LM_AUTH | L2CAP_LM_ENCRYPT | 505 L2CAP_LM_SECURE; 506 break; 507 case BT_SECURITY_FIPS: 508 opt = L2CAP_LM_AUTH | L2CAP_LM_ENCRYPT | 509 L2CAP_LM_SECURE | L2CAP_LM_FIPS; 510 break; 511 default: 512 opt = 0; 513 break; 514 } 515 516 if (test_bit(FLAG_ROLE_SWITCH, &chan->flags)) 517 opt |= L2CAP_LM_MASTER; 518 519 if (test_bit(FLAG_FORCE_RELIABLE, &chan->flags)) 520 opt |= L2CAP_LM_RELIABLE; 521 522 if (put_user(opt, (u32 __user *) optval)) 523 err = -EFAULT; 524 525 break; 526 527 case L2CAP_CONNINFO: 528 if (sk->sk_state != BT_CONNECTED && 529 !(sk->sk_state == BT_CONNECT2 && 530 test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags))) { 531 err = -ENOTCONN; 532 break; 533 } 534 535 memset(&cinfo, 0, sizeof(cinfo)); 536 cinfo.hci_handle = chan->conn->hcon->handle; 537 memcpy(cinfo.dev_class, chan->conn->hcon->dev_class, 3); 538 539 len = min(len, sizeof(cinfo)); 540 if (copy_to_user(optval, (char *) &cinfo, len)) 541 err = -EFAULT; 542 543 break; 544 545 default: 546 err = -ENOPROTOOPT; 547 break; 548 } 549 550 release_sock(sk); 551 return err; 552 } 553 554 static int l2cap_sock_getsockopt(struct socket *sock, int level, int optname, 555 char __user *optval, int __user *optlen) 556 { 557 struct sock *sk = sock->sk; 558 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 559 struct bt_security sec; 560 struct bt_power pwr; 561 u32 phys; 562 int len, mode, err = 0; 563 564 BT_DBG("sk %p", sk); 565 566 if (level == SOL_L2CAP) 567 return l2cap_sock_getsockopt_old(sock, optname, optval, optlen); 568 569 if (level != SOL_BLUETOOTH) 570 return -ENOPROTOOPT; 571 572 if (get_user(len, optlen)) 573 return -EFAULT; 574 575 lock_sock(sk); 576 577 switch (optname) { 578 case BT_SECURITY: 579 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED && 580 chan->chan_type != L2CAP_CHAN_FIXED && 581 chan->chan_type != L2CAP_CHAN_RAW) { 582 err = -EINVAL; 583 break; 584 } 585 586 memset(&sec, 0, sizeof(sec)); 587 if (chan->conn) { 588 sec.level = chan->conn->hcon->sec_level; 589 590 if (sk->sk_state == BT_CONNECTED) 591 sec.key_size = chan->conn->hcon->enc_key_size; 592 } else { 593 sec.level = chan->sec_level; 594 } 595 596 len = min_t(unsigned int, len, sizeof(sec)); 597 if (copy_to_user(optval, (char *) &sec, len)) 598 err = -EFAULT; 599 600 break; 601 602 case BT_DEFER_SETUP: 603 if (sk->sk_state != BT_BOUND && sk->sk_state != BT_LISTEN) { 604 err = -EINVAL; 605 break; 606 } 607 608 if (put_user(test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags), 609 (u32 __user *) optval)) 610 err = -EFAULT; 611 612 break; 613 614 case BT_FLUSHABLE: 615 if (put_user(test_bit(FLAG_FLUSHABLE, &chan->flags), 616 (u32 __user *) optval)) 617 err = -EFAULT; 618 619 break; 620 621 case BT_POWER: 622 if (sk->sk_type != SOCK_SEQPACKET && sk->sk_type != SOCK_STREAM 623 && sk->sk_type != SOCK_RAW) { 624 err = -EINVAL; 625 break; 626 } 627 628 pwr.force_active = test_bit(FLAG_FORCE_ACTIVE, &chan->flags); 629 630 len = min_t(unsigned int, len, sizeof(pwr)); 631 if (copy_to_user(optval, (char *) &pwr, len)) 632 err = -EFAULT; 633 634 break; 635 636 case BT_CHANNEL_POLICY: 637 if (put_user(chan->chan_policy, (u32 __user *) optval)) 638 err = -EFAULT; 639 break; 640 641 case BT_SNDMTU: 642 if (!bdaddr_type_is_le(chan->src_type)) { 643 err = -EINVAL; 644 break; 645 } 646 647 if (sk->sk_state != BT_CONNECTED) { 648 err = -ENOTCONN; 649 break; 650 } 651 652 if (put_user(chan->omtu, (u16 __user *) optval)) 653 err = -EFAULT; 654 break; 655 656 case BT_RCVMTU: 657 if (!bdaddr_type_is_le(chan->src_type)) { 658 err = -EINVAL; 659 break; 660 } 661 662 if (put_user(chan->imtu, (u16 __user *) optval)) 663 err = -EFAULT; 664 break; 665 666 case BT_PHY: 667 if (sk->sk_state != BT_CONNECTED) { 668 err = -ENOTCONN; 669 break; 670 } 671 672 phys = hci_conn_get_phy(chan->conn->hcon); 673 674 if (put_user(phys, (u32 __user *) optval)) 675 err = -EFAULT; 676 break; 677 678 case BT_MODE: 679 if (!enable_ecred) { 680 err = -ENOPROTOOPT; 681 break; 682 } 683 684 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) { 685 err = -EINVAL; 686 break; 687 } 688 689 mode = l2cap_get_mode(chan); 690 if (mode < 0) { 691 err = mode; 692 break; 693 } 694 695 if (put_user(mode, (u8 __user *) optval)) 696 err = -EFAULT; 697 break; 698 699 default: 700 err = -ENOPROTOOPT; 701 break; 702 } 703 704 release_sock(sk); 705 return err; 706 } 707 708 static bool l2cap_valid_mtu(struct l2cap_chan *chan, u16 mtu) 709 { 710 switch (chan->scid) { 711 case L2CAP_CID_ATT: 712 if (mtu < L2CAP_LE_MIN_MTU) 713 return false; 714 break; 715 716 default: 717 if (mtu < L2CAP_DEFAULT_MIN_MTU) 718 return false; 719 } 720 721 return true; 722 } 723 724 static int l2cap_sock_setsockopt_old(struct socket *sock, int optname, 725 sockptr_t optval, unsigned int optlen) 726 { 727 struct sock *sk = sock->sk; 728 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 729 struct l2cap_options opts; 730 int err = 0; 731 u32 opt; 732 733 BT_DBG("sk %p", sk); 734 735 lock_sock(sk); 736 737 switch (optname) { 738 case L2CAP_OPTIONS: 739 if (bdaddr_type_is_le(chan->src_type)) { 740 err = -EINVAL; 741 break; 742 } 743 744 if (sk->sk_state == BT_CONNECTED) { 745 err = -EINVAL; 746 break; 747 } 748 749 opts.imtu = chan->imtu; 750 opts.omtu = chan->omtu; 751 opts.flush_to = chan->flush_to; 752 opts.mode = chan->mode; 753 opts.fcs = chan->fcs; 754 opts.max_tx = chan->max_tx; 755 opts.txwin_size = chan->tx_win; 756 757 err = bt_copy_from_sockptr(&opts, sizeof(opts), optval, optlen); 758 if (err) 759 break; 760 761 if (opts.txwin_size > L2CAP_DEFAULT_EXT_WINDOW) { 762 err = -EINVAL; 763 break; 764 } 765 766 if (!l2cap_valid_mtu(chan, opts.imtu)) { 767 err = -EINVAL; 768 break; 769 } 770 771 /* Only BR/EDR modes are supported here */ 772 switch (opts.mode) { 773 case L2CAP_MODE_BASIC: 774 clear_bit(CONF_STATE2_DEVICE, &chan->conf_state); 775 break; 776 case L2CAP_MODE_ERTM: 777 case L2CAP_MODE_STREAMING: 778 if (!disable_ertm) 779 break; 780 fallthrough; 781 default: 782 err = -EINVAL; 783 break; 784 } 785 786 if (err < 0) 787 break; 788 789 chan->mode = opts.mode; 790 791 BT_DBG("mode 0x%2.2x", chan->mode); 792 793 chan->imtu = opts.imtu; 794 chan->omtu = opts.omtu; 795 chan->fcs = opts.fcs; 796 chan->max_tx = opts.max_tx; 797 chan->tx_win = opts.txwin_size; 798 chan->flush_to = opts.flush_to; 799 break; 800 801 case L2CAP_LM: 802 err = bt_copy_from_sockptr(&opt, sizeof(opt), optval, optlen); 803 if (err) 804 break; 805 806 if (opt & L2CAP_LM_FIPS) { 807 err = -EINVAL; 808 break; 809 } 810 811 if (opt & L2CAP_LM_AUTH) 812 chan->sec_level = BT_SECURITY_LOW; 813 if (opt & L2CAP_LM_ENCRYPT) 814 chan->sec_level = BT_SECURITY_MEDIUM; 815 if (opt & L2CAP_LM_SECURE) 816 chan->sec_level = BT_SECURITY_HIGH; 817 818 if (opt & L2CAP_LM_MASTER) 819 set_bit(FLAG_ROLE_SWITCH, &chan->flags); 820 else 821 clear_bit(FLAG_ROLE_SWITCH, &chan->flags); 822 823 if (opt & L2CAP_LM_RELIABLE) 824 set_bit(FLAG_FORCE_RELIABLE, &chan->flags); 825 else 826 clear_bit(FLAG_FORCE_RELIABLE, &chan->flags); 827 break; 828 829 default: 830 err = -ENOPROTOOPT; 831 break; 832 } 833 834 release_sock(sk); 835 return err; 836 } 837 838 static int l2cap_set_mode(struct l2cap_chan *chan, u8 mode) 839 { 840 switch (mode) { 841 case BT_MODE_BASIC: 842 if (bdaddr_type_is_le(chan->src_type)) 843 return -EINVAL; 844 mode = L2CAP_MODE_BASIC; 845 clear_bit(CONF_STATE2_DEVICE, &chan->conf_state); 846 break; 847 case BT_MODE_ERTM: 848 if (!disable_ertm || bdaddr_type_is_le(chan->src_type)) 849 return -EINVAL; 850 mode = L2CAP_MODE_ERTM; 851 break; 852 case BT_MODE_STREAMING: 853 if (!disable_ertm || bdaddr_type_is_le(chan->src_type)) 854 return -EINVAL; 855 mode = L2CAP_MODE_STREAMING; 856 break; 857 case BT_MODE_LE_FLOWCTL: 858 if (!bdaddr_type_is_le(chan->src_type)) 859 return -EINVAL; 860 mode = L2CAP_MODE_LE_FLOWCTL; 861 break; 862 case BT_MODE_EXT_FLOWCTL: 863 /* TODO: Add support for ECRED PDUs to BR/EDR */ 864 if (!bdaddr_type_is_le(chan->src_type)) 865 return -EINVAL; 866 mode = L2CAP_MODE_EXT_FLOWCTL; 867 break; 868 default: 869 return -EINVAL; 870 } 871 872 chan->mode = mode; 873 874 return 0; 875 } 876 877 static int l2cap_sock_setsockopt(struct socket *sock, int level, int optname, 878 sockptr_t optval, unsigned int optlen) 879 { 880 struct sock *sk = sock->sk; 881 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 882 struct bt_security sec; 883 struct bt_power pwr; 884 struct l2cap_conn *conn; 885 int err = 0; 886 u32 opt; 887 u16 mtu; 888 u8 mode; 889 890 BT_DBG("sk %p", sk); 891 892 if (level == SOL_L2CAP) 893 return l2cap_sock_setsockopt_old(sock, optname, optval, optlen); 894 895 if (level != SOL_BLUETOOTH) 896 return -ENOPROTOOPT; 897 898 lock_sock(sk); 899 900 switch (optname) { 901 case BT_SECURITY: 902 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED && 903 chan->chan_type != L2CAP_CHAN_FIXED && 904 chan->chan_type != L2CAP_CHAN_RAW) { 905 err = -EINVAL; 906 break; 907 } 908 909 sec.level = BT_SECURITY_LOW; 910 911 err = bt_copy_from_sockptr(&sec, sizeof(sec), optval, optlen); 912 if (err) 913 break; 914 915 if (sec.level < BT_SECURITY_LOW || 916 sec.level > BT_SECURITY_FIPS) { 917 err = -EINVAL; 918 break; 919 } 920 921 chan->sec_level = sec.level; 922 923 if (!chan->conn) 924 break; 925 926 conn = chan->conn; 927 928 /* change security for LE channels */ 929 if (chan->scid == L2CAP_CID_ATT) { 930 if (smp_conn_security(conn->hcon, sec.level)) { 931 err = -EINVAL; 932 break; 933 } 934 935 set_bit(FLAG_PENDING_SECURITY, &chan->flags); 936 sk->sk_state = BT_CONFIG; 937 chan->state = BT_CONFIG; 938 939 /* or for ACL link */ 940 } else if ((sk->sk_state == BT_CONNECT2 && 941 test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags)) || 942 sk->sk_state == BT_CONNECTED) { 943 if (!l2cap_chan_check_security(chan, true)) 944 set_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags); 945 else 946 sk->sk_state_change(sk); 947 } else { 948 err = -EINVAL; 949 } 950 break; 951 952 case BT_DEFER_SETUP: 953 if (sk->sk_state != BT_BOUND && sk->sk_state != BT_LISTEN) { 954 err = -EINVAL; 955 break; 956 } 957 958 err = bt_copy_from_sockptr(&opt, sizeof(opt), optval, optlen); 959 if (err) 960 break; 961 962 if (opt) { 963 set_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags); 964 set_bit(FLAG_DEFER_SETUP, &chan->flags); 965 } else { 966 clear_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags); 967 clear_bit(FLAG_DEFER_SETUP, &chan->flags); 968 } 969 break; 970 971 case BT_FLUSHABLE: 972 err = bt_copy_from_sockptr(&opt, sizeof(opt), optval, optlen); 973 if (err) 974 break; 975 976 if (opt > BT_FLUSHABLE_ON) { 977 err = -EINVAL; 978 break; 979 } 980 981 if (opt == BT_FLUSHABLE_OFF) { 982 conn = chan->conn; 983 /* proceed further only when we have l2cap_conn and 984 No Flush support in the LM */ 985 if (!conn || !lmp_no_flush_capable(conn->hcon->hdev)) { 986 err = -EINVAL; 987 break; 988 } 989 } 990 991 if (opt) 992 set_bit(FLAG_FLUSHABLE, &chan->flags); 993 else 994 clear_bit(FLAG_FLUSHABLE, &chan->flags); 995 break; 996 997 case BT_POWER: 998 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED && 999 chan->chan_type != L2CAP_CHAN_RAW) { 1000 err = -EINVAL; 1001 break; 1002 } 1003 1004 pwr.force_active = BT_POWER_FORCE_ACTIVE_ON; 1005 1006 err = bt_copy_from_sockptr(&pwr, sizeof(pwr), optval, optlen); 1007 if (err) 1008 break; 1009 1010 if (pwr.force_active) 1011 set_bit(FLAG_FORCE_ACTIVE, &chan->flags); 1012 else 1013 clear_bit(FLAG_FORCE_ACTIVE, &chan->flags); 1014 break; 1015 1016 case BT_CHANNEL_POLICY: 1017 err = bt_copy_from_sockptr(&opt, sizeof(opt), optval, optlen); 1018 if (err) 1019 break; 1020 1021 err = -EOPNOTSUPP; 1022 break; 1023 1024 case BT_SNDMTU: 1025 if (!bdaddr_type_is_le(chan->src_type)) { 1026 err = -EINVAL; 1027 break; 1028 } 1029 1030 /* Setting is not supported as it's the remote side that 1031 * decides this. 1032 */ 1033 err = -EPERM; 1034 break; 1035 1036 case BT_RCVMTU: 1037 if (!bdaddr_type_is_le(chan->src_type)) { 1038 err = -EINVAL; 1039 break; 1040 } 1041 1042 if (chan->mode == L2CAP_MODE_LE_FLOWCTL && 1043 sk->sk_state == BT_CONNECTED) { 1044 err = -EISCONN; 1045 break; 1046 } 1047 1048 err = bt_copy_from_sockptr(&mtu, sizeof(mtu), optval, optlen); 1049 if (err) 1050 break; 1051 1052 if (chan->mode == L2CAP_MODE_EXT_FLOWCTL && 1053 sk->sk_state == BT_CONNECTED) 1054 err = l2cap_chan_reconfigure(chan, mtu); 1055 else 1056 chan->imtu = mtu; 1057 1058 break; 1059 1060 case BT_MODE: 1061 if (!enable_ecred) { 1062 err = -ENOPROTOOPT; 1063 break; 1064 } 1065 1066 BT_DBG("sk->sk_state %u", sk->sk_state); 1067 1068 if (sk->sk_state != BT_BOUND) { 1069 err = -EINVAL; 1070 break; 1071 } 1072 1073 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) { 1074 err = -EINVAL; 1075 break; 1076 } 1077 1078 err = bt_copy_from_sockptr(&mode, sizeof(mode), optval, optlen); 1079 if (err) 1080 break; 1081 1082 BT_DBG("mode %u", mode); 1083 1084 err = l2cap_set_mode(chan, mode); 1085 if (err) 1086 break; 1087 1088 BT_DBG("mode 0x%2.2x", chan->mode); 1089 1090 break; 1091 1092 default: 1093 err = -ENOPROTOOPT; 1094 break; 1095 } 1096 1097 release_sock(sk); 1098 return err; 1099 } 1100 1101 static int l2cap_sock_sendmsg(struct socket *sock, struct msghdr *msg, 1102 size_t len) 1103 { 1104 struct sock *sk = sock->sk; 1105 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 1106 int err; 1107 1108 BT_DBG("sock %p, sk %p", sock, sk); 1109 1110 err = sock_error(sk); 1111 if (err) 1112 return err; 1113 1114 if (msg->msg_flags & MSG_OOB) 1115 return -EOPNOTSUPP; 1116 1117 if (sk->sk_state != BT_CONNECTED) 1118 return -ENOTCONN; 1119 1120 lock_sock(sk); 1121 err = bt_sock_wait_ready(sk, msg->msg_flags); 1122 release_sock(sk); 1123 if (err) 1124 return err; 1125 1126 l2cap_chan_lock(chan); 1127 err = l2cap_chan_send(chan, msg, len); 1128 l2cap_chan_unlock(chan); 1129 1130 return err; 1131 } 1132 1133 static void l2cap_publish_rx_avail(struct l2cap_chan *chan) 1134 { 1135 struct sock *sk = chan->data; 1136 ssize_t avail = sk->sk_rcvbuf - atomic_read(&sk->sk_rmem_alloc); 1137 int expected_skbs, skb_overhead; 1138 1139 if (avail <= 0) { 1140 l2cap_chan_rx_avail(chan, 0); 1141 return; 1142 } 1143 1144 if (!chan->mps) { 1145 l2cap_chan_rx_avail(chan, -1); 1146 return; 1147 } 1148 1149 /* Correct available memory by estimated sk_buff overhead. 1150 * This is significant due to small transfer sizes. However, accept 1151 * at least one full packet if receive space is non-zero. 1152 */ 1153 expected_skbs = DIV_ROUND_UP(avail, chan->mps); 1154 skb_overhead = expected_skbs * sizeof(struct sk_buff); 1155 if (skb_overhead < avail) 1156 l2cap_chan_rx_avail(chan, avail - skb_overhead); 1157 else 1158 l2cap_chan_rx_avail(chan, -1); 1159 } 1160 1161 static int l2cap_sock_recvmsg(struct socket *sock, struct msghdr *msg, 1162 size_t len, int flags) 1163 { 1164 struct sock *sk = sock->sk; 1165 struct l2cap_pinfo *pi = l2cap_pi(sk); 1166 int err; 1167 1168 lock_sock(sk); 1169 1170 if (sk->sk_state == BT_CONNECT2 && test_bit(BT_SK_DEFER_SETUP, 1171 &bt_sk(sk)->flags)) { 1172 if (pi->chan->mode == L2CAP_MODE_EXT_FLOWCTL) { 1173 sk->sk_state = BT_CONNECTED; 1174 pi->chan->state = BT_CONNECTED; 1175 __l2cap_ecred_conn_rsp_defer(pi->chan); 1176 } else if (bdaddr_type_is_le(pi->chan->src_type)) { 1177 sk->sk_state = BT_CONNECTED; 1178 pi->chan->state = BT_CONNECTED; 1179 __l2cap_le_connect_rsp_defer(pi->chan); 1180 } else { 1181 sk->sk_state = BT_CONFIG; 1182 pi->chan->state = BT_CONFIG; 1183 __l2cap_connect_rsp_defer(pi->chan); 1184 } 1185 1186 err = 0; 1187 goto done; 1188 } 1189 1190 release_sock(sk); 1191 1192 if (sock->type == SOCK_STREAM) 1193 err = bt_sock_stream_recvmsg(sock, msg, len, flags); 1194 else 1195 err = bt_sock_recvmsg(sock, msg, len, flags); 1196 1197 if (pi->chan->mode != L2CAP_MODE_ERTM && 1198 pi->chan->mode != L2CAP_MODE_LE_FLOWCTL && 1199 pi->chan->mode != L2CAP_MODE_EXT_FLOWCTL) 1200 return err; 1201 1202 lock_sock(sk); 1203 1204 l2cap_publish_rx_avail(pi->chan); 1205 1206 /* Attempt to put pending rx data in the socket buffer */ 1207 while (!list_empty(&pi->rx_busy)) { 1208 struct l2cap_rx_busy *rx_busy = 1209 list_first_entry(&pi->rx_busy, 1210 struct l2cap_rx_busy, 1211 list); 1212 if (__sock_queue_rcv_skb(sk, rx_busy->skb) < 0) 1213 goto done; 1214 list_del(&rx_busy->list); 1215 kfree(rx_busy); 1216 } 1217 1218 /* Restore data flow when half of the receive buffer is 1219 * available. This avoids resending large numbers of 1220 * frames. 1221 */ 1222 if (test_bit(CONN_LOCAL_BUSY, &pi->chan->conn_state) && 1223 atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf >> 1) 1224 l2cap_chan_busy(pi->chan, 0); 1225 1226 done: 1227 release_sock(sk); 1228 return err; 1229 } 1230 1231 /* Kill socket (only if zapped and orphan) 1232 * Must be called on unlocked socket, with l2cap channel lock. 1233 */ 1234 static void l2cap_sock_kill(struct sock *sk) 1235 { 1236 if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket) 1237 return; 1238 1239 BT_DBG("sk %p state %s", sk, state_to_string(sk->sk_state)); 1240 1241 /* Sock is dead, so set chan data to NULL, avoid other task use invalid 1242 * sock pointer. 1243 */ 1244 l2cap_pi(sk)->chan->data = NULL; 1245 /* Kill poor orphan */ 1246 1247 l2cap_chan_put(l2cap_pi(sk)->chan); 1248 sock_set_flag(sk, SOCK_DEAD); 1249 sock_put(sk); 1250 } 1251 1252 static int __l2cap_wait_ack(struct sock *sk, struct l2cap_chan *chan) 1253 { 1254 DECLARE_WAITQUEUE(wait, current); 1255 int err = 0; 1256 int timeo = L2CAP_WAIT_ACK_POLL_PERIOD; 1257 /* Timeout to prevent infinite loop */ 1258 unsigned long timeout = jiffies + L2CAP_WAIT_ACK_TIMEOUT; 1259 1260 add_wait_queue(sk_sleep(sk), &wait); 1261 set_current_state(TASK_INTERRUPTIBLE); 1262 do { 1263 BT_DBG("Waiting for %d ACKs, timeout %04d ms", 1264 chan->unacked_frames, time_after(jiffies, timeout) ? 0 : 1265 jiffies_to_msecs(timeout - jiffies)); 1266 1267 if (!timeo) 1268 timeo = L2CAP_WAIT_ACK_POLL_PERIOD; 1269 1270 if (signal_pending(current)) { 1271 err = sock_intr_errno(timeo); 1272 break; 1273 } 1274 1275 release_sock(sk); 1276 timeo = schedule_timeout(timeo); 1277 lock_sock(sk); 1278 set_current_state(TASK_INTERRUPTIBLE); 1279 1280 err = sock_error(sk); 1281 if (err) 1282 break; 1283 1284 if (time_after(jiffies, timeout)) { 1285 err = -ENOLINK; 1286 break; 1287 } 1288 1289 } while (chan->unacked_frames > 0 && 1290 chan->state == BT_CONNECTED); 1291 1292 set_current_state(TASK_RUNNING); 1293 remove_wait_queue(sk_sleep(sk), &wait); 1294 return err; 1295 } 1296 1297 static int l2cap_sock_shutdown(struct socket *sock, int how) 1298 { 1299 struct sock *sk = sock->sk; 1300 struct l2cap_chan *chan; 1301 struct l2cap_conn *conn; 1302 int err = 0; 1303 1304 BT_DBG("sock %p, sk %p, how %d", sock, sk, how); 1305 1306 /* 'how' parameter is mapped to sk_shutdown as follows: 1307 * SHUT_RD (0) --> RCV_SHUTDOWN (1) 1308 * SHUT_WR (1) --> SEND_SHUTDOWN (2) 1309 * SHUT_RDWR (2) --> SHUTDOWN_MASK (3) 1310 */ 1311 how++; 1312 1313 if (!sk) 1314 return 0; 1315 1316 lock_sock(sk); 1317 1318 if ((sk->sk_shutdown & how) == how) 1319 goto shutdown_already; 1320 1321 BT_DBG("Handling sock shutdown"); 1322 1323 /* prevent sk structure from being freed whilst unlocked */ 1324 sock_hold(sk); 1325 1326 chan = l2cap_pi(sk)->chan; 1327 /* prevent chan structure from being freed whilst unlocked */ 1328 l2cap_chan_hold(chan); 1329 1330 BT_DBG("chan %p state %s", chan, state_to_string(chan->state)); 1331 1332 if (chan->mode == L2CAP_MODE_ERTM && 1333 chan->unacked_frames > 0 && 1334 chan->state == BT_CONNECTED) { 1335 err = __l2cap_wait_ack(sk, chan); 1336 1337 /* After waiting for ACKs, check whether shutdown 1338 * has already been actioned to close the L2CAP 1339 * link such as by l2cap_disconnection_req(). 1340 */ 1341 if ((sk->sk_shutdown & how) == how) 1342 goto shutdown_matched; 1343 } 1344 1345 /* Try setting the RCV_SHUTDOWN bit, return early if SEND_SHUTDOWN 1346 * is already set 1347 */ 1348 if ((how & RCV_SHUTDOWN) && !(sk->sk_shutdown & RCV_SHUTDOWN)) { 1349 sk->sk_shutdown |= RCV_SHUTDOWN; 1350 if ((sk->sk_shutdown & how) == how) 1351 goto shutdown_matched; 1352 } 1353 1354 sk->sk_shutdown |= SEND_SHUTDOWN; 1355 release_sock(sk); 1356 1357 l2cap_chan_lock(chan); 1358 conn = chan->conn; 1359 if (conn) 1360 /* prevent conn structure from being freed */ 1361 l2cap_conn_get(conn); 1362 l2cap_chan_unlock(chan); 1363 1364 if (conn) 1365 /* mutex lock must be taken before l2cap_chan_lock() */ 1366 mutex_lock(&conn->chan_lock); 1367 1368 l2cap_chan_lock(chan); 1369 l2cap_chan_close(chan, 0); 1370 l2cap_chan_unlock(chan); 1371 1372 if (conn) { 1373 mutex_unlock(&conn->chan_lock); 1374 l2cap_conn_put(conn); 1375 } 1376 1377 lock_sock(sk); 1378 1379 if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime && 1380 !(current->flags & PF_EXITING)) 1381 err = bt_sock_wait_state(sk, BT_CLOSED, 1382 sk->sk_lingertime); 1383 1384 shutdown_matched: 1385 l2cap_chan_put(chan); 1386 sock_put(sk); 1387 1388 shutdown_already: 1389 if (!err && sk->sk_err) 1390 err = -sk->sk_err; 1391 1392 release_sock(sk); 1393 1394 BT_DBG("Sock shutdown complete err: %d", err); 1395 1396 return err; 1397 } 1398 1399 static int l2cap_sock_release(struct socket *sock) 1400 { 1401 struct sock *sk = sock->sk; 1402 int err; 1403 struct l2cap_chan *chan; 1404 1405 BT_DBG("sock %p, sk %p", sock, sk); 1406 1407 if (!sk) 1408 return 0; 1409 1410 l2cap_sock_cleanup_listen(sk); 1411 bt_sock_unlink(&l2cap_sk_list, sk); 1412 1413 err = l2cap_sock_shutdown(sock, SHUT_RDWR); 1414 chan = l2cap_pi(sk)->chan; 1415 1416 l2cap_chan_hold(chan); 1417 l2cap_chan_lock(chan); 1418 1419 sock_orphan(sk); 1420 l2cap_sock_kill(sk); 1421 1422 l2cap_chan_unlock(chan); 1423 l2cap_chan_put(chan); 1424 1425 return err; 1426 } 1427 1428 static void l2cap_sock_cleanup_listen(struct sock *parent) 1429 { 1430 struct sock *sk; 1431 1432 BT_DBG("parent %p state %s", parent, 1433 state_to_string(parent->sk_state)); 1434 1435 /* Close not yet accepted channels */ 1436 while ((sk = bt_accept_dequeue(parent, NULL))) { 1437 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 1438 1439 BT_DBG("child chan %p state %s", chan, 1440 state_to_string(chan->state)); 1441 1442 l2cap_chan_hold(chan); 1443 l2cap_chan_lock(chan); 1444 1445 __clear_chan_timer(chan); 1446 l2cap_chan_close(chan, ECONNRESET); 1447 l2cap_sock_kill(sk); 1448 1449 l2cap_chan_unlock(chan); 1450 l2cap_chan_put(chan); 1451 } 1452 } 1453 1454 static struct l2cap_chan *l2cap_sock_new_connection_cb(struct l2cap_chan *chan) 1455 { 1456 struct sock *sk, *parent = chan->data; 1457 1458 lock_sock(parent); 1459 1460 /* Check for backlog size */ 1461 if (sk_acceptq_is_full(parent)) { 1462 BT_DBG("backlog full %d", parent->sk_ack_backlog); 1463 release_sock(parent); 1464 return NULL; 1465 } 1466 1467 sk = l2cap_sock_alloc(sock_net(parent), NULL, BTPROTO_L2CAP, 1468 GFP_ATOMIC, 0); 1469 if (!sk) { 1470 release_sock(parent); 1471 return NULL; 1472 } 1473 1474 bt_sock_reclassify_lock(sk, BTPROTO_L2CAP); 1475 1476 l2cap_sock_init(sk, parent); 1477 1478 bt_accept_enqueue(parent, sk, false); 1479 1480 release_sock(parent); 1481 1482 return l2cap_pi(sk)->chan; 1483 } 1484 1485 static int l2cap_sock_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) 1486 { 1487 struct sock *sk; 1488 struct l2cap_pinfo *pi; 1489 int err; 1490 1491 sk = chan->data; 1492 if (!sk) 1493 return -ENXIO; 1494 1495 pi = l2cap_pi(sk); 1496 lock_sock(sk); 1497 if (chan->mode == L2CAP_MODE_ERTM && !list_empty(&pi->rx_busy)) { 1498 err = -ENOMEM; 1499 goto done; 1500 } 1501 1502 if (chan->mode != L2CAP_MODE_ERTM && 1503 chan->mode != L2CAP_MODE_STREAMING && 1504 chan->mode != L2CAP_MODE_LE_FLOWCTL && 1505 chan->mode != L2CAP_MODE_EXT_FLOWCTL) { 1506 /* Even if no filter is attached, we could potentially 1507 * get errors from security modules, etc. 1508 */ 1509 err = sk_filter(sk, skb); 1510 if (err) 1511 goto done; 1512 } 1513 1514 err = __sock_queue_rcv_skb(sk, skb); 1515 1516 l2cap_publish_rx_avail(chan); 1517 1518 /* For ERTM and LE, handle a skb that doesn't fit into the recv 1519 * buffer. This is important to do because the data frames 1520 * have already been acked, so the skb cannot be discarded. 1521 * 1522 * Notify the l2cap core that the buffer is full, so the 1523 * LOCAL_BUSY state is entered and no more frames are 1524 * acked and reassembled until there is buffer space 1525 * available. 1526 */ 1527 if (err < 0 && 1528 (chan->mode == L2CAP_MODE_ERTM || 1529 chan->mode == L2CAP_MODE_LE_FLOWCTL || 1530 chan->mode == L2CAP_MODE_EXT_FLOWCTL)) { 1531 struct l2cap_rx_busy *rx_busy = 1532 kmalloc(sizeof(*rx_busy), GFP_KERNEL); 1533 if (!rx_busy) { 1534 err = -ENOMEM; 1535 goto done; 1536 } 1537 rx_busy->skb = skb; 1538 list_add_tail(&rx_busy->list, &pi->rx_busy); 1539 l2cap_chan_busy(chan, 1); 1540 err = 0; 1541 } 1542 1543 done: 1544 release_sock(sk); 1545 1546 return err; 1547 } 1548 1549 static void l2cap_sock_close_cb(struct l2cap_chan *chan) 1550 { 1551 struct sock *sk = chan->data; 1552 1553 if (!sk) 1554 return; 1555 1556 l2cap_sock_kill(sk); 1557 } 1558 1559 static void l2cap_sock_teardown_cb(struct l2cap_chan *chan, int err) 1560 { 1561 struct sock *sk = chan->data; 1562 struct sock *parent; 1563 1564 if (!sk) 1565 return; 1566 1567 BT_DBG("chan %p state %s", chan, state_to_string(chan->state)); 1568 1569 /* This callback can be called both for server (BT_LISTEN) 1570 * sockets as well as "normal" ones. To avoid lockdep warnings 1571 * with child socket locking (through l2cap_sock_cleanup_listen) 1572 * we need separation into separate nesting levels. The simplest 1573 * way to accomplish this is to inherit the nesting level used 1574 * for the channel. 1575 */ 1576 lock_sock_nested(sk, atomic_read(&chan->nesting)); 1577 1578 parent = bt_sk(sk)->parent; 1579 1580 switch (chan->state) { 1581 case BT_OPEN: 1582 case BT_BOUND: 1583 case BT_CLOSED: 1584 break; 1585 case BT_LISTEN: 1586 l2cap_sock_cleanup_listen(sk); 1587 sk->sk_state = BT_CLOSED; 1588 chan->state = BT_CLOSED; 1589 1590 break; 1591 default: 1592 sk->sk_state = BT_CLOSED; 1593 chan->state = BT_CLOSED; 1594 1595 sk->sk_err = err; 1596 1597 if (parent) { 1598 bt_accept_unlink(sk); 1599 parent->sk_data_ready(parent); 1600 } else { 1601 sk->sk_state_change(sk); 1602 } 1603 1604 break; 1605 } 1606 release_sock(sk); 1607 1608 /* Only zap after cleanup to avoid use after free race */ 1609 sock_set_flag(sk, SOCK_ZAPPED); 1610 1611 } 1612 1613 static void l2cap_sock_state_change_cb(struct l2cap_chan *chan, int state, 1614 int err) 1615 { 1616 struct sock *sk = chan->data; 1617 1618 sk->sk_state = state; 1619 1620 if (err) 1621 sk->sk_err = err; 1622 } 1623 1624 static struct sk_buff *l2cap_sock_alloc_skb_cb(struct l2cap_chan *chan, 1625 unsigned long hdr_len, 1626 unsigned long len, int nb) 1627 { 1628 struct sock *sk = chan->data; 1629 struct sk_buff *skb; 1630 int err; 1631 1632 l2cap_chan_unlock(chan); 1633 skb = bt_skb_send_alloc(sk, hdr_len + len, nb, &err); 1634 l2cap_chan_lock(chan); 1635 1636 if (!skb) 1637 return ERR_PTR(err); 1638 1639 /* Channel lock is released before requesting new skb and then 1640 * reacquired thus we need to recheck channel state. 1641 */ 1642 if (chan->state != BT_CONNECTED) { 1643 kfree_skb(skb); 1644 return ERR_PTR(-ENOTCONN); 1645 } 1646 1647 skb->priority = sk->sk_priority; 1648 1649 bt_cb(skb)->l2cap.chan = chan; 1650 1651 return skb; 1652 } 1653 1654 static void l2cap_sock_ready_cb(struct l2cap_chan *chan) 1655 { 1656 struct sock *sk = chan->data; 1657 struct sock *parent; 1658 1659 lock_sock(sk); 1660 1661 parent = bt_sk(sk)->parent; 1662 1663 BT_DBG("sk %p, parent %p", sk, parent); 1664 1665 sk->sk_state = BT_CONNECTED; 1666 sk->sk_state_change(sk); 1667 1668 if (parent) 1669 parent->sk_data_ready(parent); 1670 1671 release_sock(sk); 1672 } 1673 1674 static void l2cap_sock_defer_cb(struct l2cap_chan *chan) 1675 { 1676 struct sock *parent, *sk = chan->data; 1677 1678 lock_sock(sk); 1679 1680 parent = bt_sk(sk)->parent; 1681 if (parent) 1682 parent->sk_data_ready(parent); 1683 1684 release_sock(sk); 1685 } 1686 1687 static void l2cap_sock_resume_cb(struct l2cap_chan *chan) 1688 { 1689 struct sock *sk = chan->data; 1690 1691 if (test_and_clear_bit(FLAG_PENDING_SECURITY, &chan->flags)) { 1692 sk->sk_state = BT_CONNECTED; 1693 chan->state = BT_CONNECTED; 1694 } 1695 1696 clear_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags); 1697 sk->sk_state_change(sk); 1698 } 1699 1700 static void l2cap_sock_set_shutdown_cb(struct l2cap_chan *chan) 1701 { 1702 struct sock *sk = chan->data; 1703 1704 lock_sock(sk); 1705 sk->sk_shutdown = SHUTDOWN_MASK; 1706 release_sock(sk); 1707 } 1708 1709 static long l2cap_sock_get_sndtimeo_cb(struct l2cap_chan *chan) 1710 { 1711 struct sock *sk = chan->data; 1712 1713 return sk->sk_sndtimeo; 1714 } 1715 1716 static struct pid *l2cap_sock_get_peer_pid_cb(struct l2cap_chan *chan) 1717 { 1718 struct sock *sk = chan->data; 1719 1720 return sk->sk_peer_pid; 1721 } 1722 1723 static void l2cap_sock_suspend_cb(struct l2cap_chan *chan) 1724 { 1725 struct sock *sk = chan->data; 1726 1727 set_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags); 1728 sk->sk_state_change(sk); 1729 } 1730 1731 static int l2cap_sock_filter(struct l2cap_chan *chan, struct sk_buff *skb) 1732 { 1733 struct sock *sk = chan->data; 1734 1735 switch (chan->mode) { 1736 case L2CAP_MODE_ERTM: 1737 case L2CAP_MODE_STREAMING: 1738 return sk_filter(sk, skb); 1739 } 1740 1741 return 0; 1742 } 1743 1744 static const struct l2cap_ops l2cap_chan_ops = { 1745 .name = "L2CAP Socket Interface", 1746 .new_connection = l2cap_sock_new_connection_cb, 1747 .recv = l2cap_sock_recv_cb, 1748 .close = l2cap_sock_close_cb, 1749 .teardown = l2cap_sock_teardown_cb, 1750 .state_change = l2cap_sock_state_change_cb, 1751 .ready = l2cap_sock_ready_cb, 1752 .defer = l2cap_sock_defer_cb, 1753 .resume = l2cap_sock_resume_cb, 1754 .suspend = l2cap_sock_suspend_cb, 1755 .set_shutdown = l2cap_sock_set_shutdown_cb, 1756 .get_sndtimeo = l2cap_sock_get_sndtimeo_cb, 1757 .get_peer_pid = l2cap_sock_get_peer_pid_cb, 1758 .alloc_skb = l2cap_sock_alloc_skb_cb, 1759 .filter = l2cap_sock_filter, 1760 }; 1761 1762 static void l2cap_sock_destruct(struct sock *sk) 1763 { 1764 struct l2cap_rx_busy *rx_busy, *next; 1765 1766 BT_DBG("sk %p", sk); 1767 1768 if (l2cap_pi(sk)->chan) { 1769 l2cap_pi(sk)->chan->data = NULL; 1770 l2cap_chan_put(l2cap_pi(sk)->chan); 1771 } 1772 1773 list_for_each_entry_safe(rx_busy, next, &l2cap_pi(sk)->rx_busy, list) { 1774 kfree_skb(rx_busy->skb); 1775 list_del(&rx_busy->list); 1776 kfree(rx_busy); 1777 } 1778 1779 skb_queue_purge(&sk->sk_receive_queue); 1780 skb_queue_purge(&sk->sk_write_queue); 1781 } 1782 1783 static void l2cap_skb_msg_name(struct sk_buff *skb, void *msg_name, 1784 int *msg_namelen) 1785 { 1786 DECLARE_SOCKADDR(struct sockaddr_l2 *, la, msg_name); 1787 1788 memset(la, 0, sizeof(struct sockaddr_l2)); 1789 la->l2_family = AF_BLUETOOTH; 1790 la->l2_psm = bt_cb(skb)->l2cap.psm; 1791 bacpy(&la->l2_bdaddr, &bt_cb(skb)->l2cap.bdaddr); 1792 1793 *msg_namelen = sizeof(struct sockaddr_l2); 1794 } 1795 1796 static void l2cap_sock_init(struct sock *sk, struct sock *parent) 1797 { 1798 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 1799 1800 BT_DBG("sk %p", sk); 1801 1802 if (parent) { 1803 struct l2cap_chan *pchan = l2cap_pi(parent)->chan; 1804 1805 sk->sk_type = parent->sk_type; 1806 bt_sk(sk)->flags = bt_sk(parent)->flags; 1807 1808 chan->chan_type = pchan->chan_type; 1809 chan->imtu = pchan->imtu; 1810 chan->omtu = pchan->omtu; 1811 chan->conf_state = pchan->conf_state; 1812 chan->mode = pchan->mode; 1813 chan->fcs = pchan->fcs; 1814 chan->max_tx = pchan->max_tx; 1815 chan->tx_win = pchan->tx_win; 1816 chan->tx_win_max = pchan->tx_win_max; 1817 chan->sec_level = pchan->sec_level; 1818 chan->flags = pchan->flags; 1819 chan->tx_credits = pchan->tx_credits; 1820 chan->rx_credits = pchan->rx_credits; 1821 1822 if (chan->chan_type == L2CAP_CHAN_FIXED) { 1823 chan->scid = pchan->scid; 1824 chan->dcid = pchan->scid; 1825 } 1826 1827 security_sk_clone(parent, sk); 1828 } else { 1829 switch (sk->sk_type) { 1830 case SOCK_RAW: 1831 chan->chan_type = L2CAP_CHAN_RAW; 1832 break; 1833 case SOCK_DGRAM: 1834 chan->chan_type = L2CAP_CHAN_CONN_LESS; 1835 bt_sk(sk)->skb_msg_name = l2cap_skb_msg_name; 1836 break; 1837 case SOCK_SEQPACKET: 1838 case SOCK_STREAM: 1839 chan->chan_type = L2CAP_CHAN_CONN_ORIENTED; 1840 break; 1841 } 1842 1843 chan->imtu = L2CAP_DEFAULT_MTU; 1844 chan->omtu = 0; 1845 if (!disable_ertm && sk->sk_type == SOCK_STREAM) { 1846 chan->mode = L2CAP_MODE_ERTM; 1847 set_bit(CONF_STATE2_DEVICE, &chan->conf_state); 1848 } else { 1849 chan->mode = L2CAP_MODE_BASIC; 1850 } 1851 1852 l2cap_chan_set_defaults(chan); 1853 } 1854 1855 /* Default config options */ 1856 chan->flush_to = L2CAP_DEFAULT_FLUSH_TO; 1857 1858 chan->data = sk; 1859 chan->ops = &l2cap_chan_ops; 1860 1861 l2cap_publish_rx_avail(chan); 1862 } 1863 1864 static struct proto l2cap_proto = { 1865 .name = "L2CAP", 1866 .owner = THIS_MODULE, 1867 .obj_size = sizeof(struct l2cap_pinfo) 1868 }; 1869 1870 static struct sock *l2cap_sock_alloc(struct net *net, struct socket *sock, 1871 int proto, gfp_t prio, int kern) 1872 { 1873 struct sock *sk; 1874 struct l2cap_chan *chan; 1875 1876 sk = bt_sock_alloc(net, sock, &l2cap_proto, proto, prio, kern); 1877 if (!sk) 1878 return NULL; 1879 1880 sk->sk_destruct = l2cap_sock_destruct; 1881 sk->sk_sndtimeo = L2CAP_CONN_TIMEOUT; 1882 1883 INIT_LIST_HEAD(&l2cap_pi(sk)->rx_busy); 1884 1885 chan = l2cap_chan_create(); 1886 if (!chan) { 1887 sk_free(sk); 1888 return NULL; 1889 } 1890 1891 l2cap_chan_hold(chan); 1892 1893 l2cap_pi(sk)->chan = chan; 1894 1895 return sk; 1896 } 1897 1898 static int l2cap_sock_create(struct net *net, struct socket *sock, int protocol, 1899 int kern) 1900 { 1901 struct sock *sk; 1902 1903 BT_DBG("sock %p", sock); 1904 1905 sock->state = SS_UNCONNECTED; 1906 1907 if (sock->type != SOCK_SEQPACKET && sock->type != SOCK_STREAM && 1908 sock->type != SOCK_DGRAM && sock->type != SOCK_RAW) 1909 return -ESOCKTNOSUPPORT; 1910 1911 if (sock->type == SOCK_RAW && !kern && !capable(CAP_NET_RAW)) 1912 return -EPERM; 1913 1914 sock->ops = &l2cap_sock_ops; 1915 1916 sk = l2cap_sock_alloc(net, sock, protocol, GFP_ATOMIC, kern); 1917 if (!sk) 1918 return -ENOMEM; 1919 1920 l2cap_sock_init(sk, NULL); 1921 bt_sock_link(&l2cap_sk_list, sk); 1922 return 0; 1923 } 1924 1925 static const struct proto_ops l2cap_sock_ops = { 1926 .family = PF_BLUETOOTH, 1927 .owner = THIS_MODULE, 1928 .release = l2cap_sock_release, 1929 .bind = l2cap_sock_bind, 1930 .connect = l2cap_sock_connect, 1931 .listen = l2cap_sock_listen, 1932 .accept = l2cap_sock_accept, 1933 .getname = l2cap_sock_getname, 1934 .sendmsg = l2cap_sock_sendmsg, 1935 .recvmsg = l2cap_sock_recvmsg, 1936 .poll = bt_sock_poll, 1937 .ioctl = bt_sock_ioctl, 1938 .gettstamp = sock_gettstamp, 1939 .mmap = sock_no_mmap, 1940 .socketpair = sock_no_socketpair, 1941 .shutdown = l2cap_sock_shutdown, 1942 .setsockopt = l2cap_sock_setsockopt, 1943 .getsockopt = l2cap_sock_getsockopt 1944 }; 1945 1946 static const struct net_proto_family l2cap_sock_family_ops = { 1947 .family = PF_BLUETOOTH, 1948 .owner = THIS_MODULE, 1949 .create = l2cap_sock_create, 1950 }; 1951 1952 int __init l2cap_init_sockets(void) 1953 { 1954 int err; 1955 1956 BUILD_BUG_ON(sizeof(struct sockaddr_l2) > sizeof(struct sockaddr)); 1957 1958 err = proto_register(&l2cap_proto, 0); 1959 if (err < 0) 1960 return err; 1961 1962 err = bt_sock_register(BTPROTO_L2CAP, &l2cap_sock_family_ops); 1963 if (err < 0) { 1964 BT_ERR("L2CAP socket registration failed"); 1965 goto error; 1966 } 1967 1968 err = bt_procfs_init(&init_net, "l2cap", &l2cap_sk_list, 1969 NULL); 1970 if (err < 0) { 1971 BT_ERR("Failed to create L2CAP proc file"); 1972 bt_sock_unregister(BTPROTO_L2CAP); 1973 goto error; 1974 } 1975 1976 BT_INFO("L2CAP socket layer initialized"); 1977 1978 return 0; 1979 1980 error: 1981 proto_unregister(&l2cap_proto); 1982 return err; 1983 } 1984 1985 void l2cap_cleanup_sockets(void) 1986 { 1987 bt_procfs_cleanup(&init_net, "l2cap"); 1988 bt_sock_unregister(BTPROTO_L2CAP); 1989 proto_unregister(&l2cap_proto); 1990 } 1991