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 sk->sk_sndtimeo); 259 if (err) 260 return err; 261 262 lock_sock(sk); 263 264 err = bt_sock_wait_state(sk, BT_CONNECTED, 265 sock_sndtimeo(sk, flags & O_NONBLOCK)); 266 267 release_sock(sk); 268 269 return err; 270 } 271 272 static int l2cap_sock_listen(struct socket *sock, int backlog) 273 { 274 struct sock *sk = sock->sk; 275 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 276 int err = 0; 277 278 BT_DBG("sk %p backlog %d", sk, backlog); 279 280 lock_sock(sk); 281 282 if (sk->sk_state != BT_BOUND) { 283 err = -EBADFD; 284 goto done; 285 } 286 287 if (sk->sk_type != SOCK_SEQPACKET && sk->sk_type != SOCK_STREAM) { 288 err = -EINVAL; 289 goto done; 290 } 291 292 switch (chan->mode) { 293 case L2CAP_MODE_BASIC: 294 case L2CAP_MODE_LE_FLOWCTL: 295 break; 296 case L2CAP_MODE_EXT_FLOWCTL: 297 if (!enable_ecred) { 298 err = -EOPNOTSUPP; 299 goto done; 300 } 301 break; 302 case L2CAP_MODE_ERTM: 303 case L2CAP_MODE_STREAMING: 304 if (!disable_ertm) 305 break; 306 fallthrough; 307 default: 308 err = -EOPNOTSUPP; 309 goto done; 310 } 311 312 sk->sk_max_ack_backlog = backlog; 313 sk->sk_ack_backlog = 0; 314 315 /* Listening channels need to use nested locking in order not to 316 * cause lockdep warnings when the created child channels end up 317 * being locked in the same thread as the parent channel. 318 */ 319 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT); 320 321 chan->state = BT_LISTEN; 322 sk->sk_state = BT_LISTEN; 323 324 done: 325 release_sock(sk); 326 return err; 327 } 328 329 static int l2cap_sock_accept(struct socket *sock, struct socket *newsock, 330 int flags, bool kern) 331 { 332 DEFINE_WAIT_FUNC(wait, woken_wake_function); 333 struct sock *sk = sock->sk, *nsk; 334 long timeo; 335 int err = 0; 336 337 lock_sock_nested(sk, L2CAP_NESTING_PARENT); 338 339 timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK); 340 341 BT_DBG("sk %p timeo %ld", sk, timeo); 342 343 /* Wait for an incoming connection. (wake-one). */ 344 add_wait_queue_exclusive(sk_sleep(sk), &wait); 345 while (1) { 346 if (sk->sk_state != BT_LISTEN) { 347 err = -EBADFD; 348 break; 349 } 350 351 nsk = bt_accept_dequeue(sk, newsock); 352 if (nsk) 353 break; 354 355 if (!timeo) { 356 err = -EAGAIN; 357 break; 358 } 359 360 if (signal_pending(current)) { 361 err = sock_intr_errno(timeo); 362 break; 363 } 364 365 release_sock(sk); 366 367 timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo); 368 369 lock_sock_nested(sk, L2CAP_NESTING_PARENT); 370 } 371 remove_wait_queue(sk_sleep(sk), &wait); 372 373 if (err) 374 goto done; 375 376 newsock->state = SS_CONNECTED; 377 378 BT_DBG("new socket %p", nsk); 379 380 done: 381 release_sock(sk); 382 return err; 383 } 384 385 static int l2cap_sock_getname(struct socket *sock, struct sockaddr *addr, 386 int peer) 387 { 388 struct sockaddr_l2 *la = (struct sockaddr_l2 *) addr; 389 struct sock *sk = sock->sk; 390 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 391 392 BT_DBG("sock %p, sk %p", sock, sk); 393 394 if (peer && sk->sk_state != BT_CONNECTED && 395 sk->sk_state != BT_CONNECT && sk->sk_state != BT_CONNECT2 && 396 sk->sk_state != BT_CONFIG) 397 return -ENOTCONN; 398 399 memset(la, 0, sizeof(struct sockaddr_l2)); 400 addr->sa_family = AF_BLUETOOTH; 401 402 la->l2_psm = chan->psm; 403 404 if (peer) { 405 bacpy(&la->l2_bdaddr, &chan->dst); 406 la->l2_cid = cpu_to_le16(chan->dcid); 407 la->l2_bdaddr_type = chan->dst_type; 408 } else { 409 bacpy(&la->l2_bdaddr, &chan->src); 410 la->l2_cid = cpu_to_le16(chan->scid); 411 la->l2_bdaddr_type = chan->src_type; 412 } 413 414 return sizeof(struct sockaddr_l2); 415 } 416 417 static int l2cap_get_mode(struct l2cap_chan *chan) 418 { 419 switch (chan->mode) { 420 case L2CAP_MODE_BASIC: 421 return BT_MODE_BASIC; 422 case L2CAP_MODE_ERTM: 423 return BT_MODE_ERTM; 424 case L2CAP_MODE_STREAMING: 425 return BT_MODE_STREAMING; 426 case L2CAP_MODE_LE_FLOWCTL: 427 return BT_MODE_LE_FLOWCTL; 428 case L2CAP_MODE_EXT_FLOWCTL: 429 return BT_MODE_EXT_FLOWCTL; 430 } 431 432 return -EINVAL; 433 } 434 435 static int l2cap_sock_getsockopt_old(struct socket *sock, int optname, 436 char __user *optval, int __user *optlen) 437 { 438 struct sock *sk = sock->sk; 439 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 440 struct l2cap_options opts; 441 struct l2cap_conninfo cinfo; 442 int len, err = 0; 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_t(unsigned int, 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_t(unsigned int, 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 len, 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 len = min_t(unsigned int, sizeof(opts), optlen); 758 if (copy_from_sockptr(&opts, optval, len)) { 759 err = -EFAULT; 760 break; 761 } 762 763 if (opts.txwin_size > L2CAP_DEFAULT_EXT_WINDOW) { 764 err = -EINVAL; 765 break; 766 } 767 768 if (!l2cap_valid_mtu(chan, opts.imtu)) { 769 err = -EINVAL; 770 break; 771 } 772 773 /* Only BR/EDR modes are supported here */ 774 switch (opts.mode) { 775 case L2CAP_MODE_BASIC: 776 clear_bit(CONF_STATE2_DEVICE, &chan->conf_state); 777 break; 778 case L2CAP_MODE_ERTM: 779 case L2CAP_MODE_STREAMING: 780 if (!disable_ertm) 781 break; 782 fallthrough; 783 default: 784 err = -EINVAL; 785 break; 786 } 787 788 if (err < 0) 789 break; 790 791 chan->mode = opts.mode; 792 793 BT_DBG("mode 0x%2.2x", chan->mode); 794 795 chan->imtu = opts.imtu; 796 chan->omtu = opts.omtu; 797 chan->fcs = opts.fcs; 798 chan->max_tx = opts.max_tx; 799 chan->tx_win = opts.txwin_size; 800 chan->flush_to = opts.flush_to; 801 break; 802 803 case L2CAP_LM: 804 if (copy_from_sockptr(&opt, optval, sizeof(u32))) { 805 err = -EFAULT; 806 break; 807 } 808 809 if (opt & L2CAP_LM_FIPS) { 810 err = -EINVAL; 811 break; 812 } 813 814 if (opt & L2CAP_LM_AUTH) 815 chan->sec_level = BT_SECURITY_LOW; 816 if (opt & L2CAP_LM_ENCRYPT) 817 chan->sec_level = BT_SECURITY_MEDIUM; 818 if (opt & L2CAP_LM_SECURE) 819 chan->sec_level = BT_SECURITY_HIGH; 820 821 if (opt & L2CAP_LM_MASTER) 822 set_bit(FLAG_ROLE_SWITCH, &chan->flags); 823 else 824 clear_bit(FLAG_ROLE_SWITCH, &chan->flags); 825 826 if (opt & L2CAP_LM_RELIABLE) 827 set_bit(FLAG_FORCE_RELIABLE, &chan->flags); 828 else 829 clear_bit(FLAG_FORCE_RELIABLE, &chan->flags); 830 break; 831 832 default: 833 err = -ENOPROTOOPT; 834 break; 835 } 836 837 release_sock(sk); 838 return err; 839 } 840 841 static int l2cap_set_mode(struct l2cap_chan *chan, u8 mode) 842 { 843 switch (mode) { 844 case BT_MODE_BASIC: 845 if (bdaddr_type_is_le(chan->src_type)) 846 return -EINVAL; 847 mode = L2CAP_MODE_BASIC; 848 clear_bit(CONF_STATE2_DEVICE, &chan->conf_state); 849 break; 850 case BT_MODE_ERTM: 851 if (!disable_ertm || bdaddr_type_is_le(chan->src_type)) 852 return -EINVAL; 853 mode = L2CAP_MODE_ERTM; 854 break; 855 case BT_MODE_STREAMING: 856 if (!disable_ertm || bdaddr_type_is_le(chan->src_type)) 857 return -EINVAL; 858 mode = L2CAP_MODE_STREAMING; 859 break; 860 case BT_MODE_LE_FLOWCTL: 861 if (!bdaddr_type_is_le(chan->src_type)) 862 return -EINVAL; 863 mode = L2CAP_MODE_LE_FLOWCTL; 864 break; 865 case BT_MODE_EXT_FLOWCTL: 866 /* TODO: Add support for ECRED PDUs to BR/EDR */ 867 if (!bdaddr_type_is_le(chan->src_type)) 868 return -EINVAL; 869 mode = L2CAP_MODE_EXT_FLOWCTL; 870 break; 871 default: 872 return -EINVAL; 873 } 874 875 chan->mode = mode; 876 877 return 0; 878 } 879 880 static int l2cap_sock_setsockopt(struct socket *sock, int level, int optname, 881 sockptr_t optval, unsigned int optlen) 882 { 883 struct sock *sk = sock->sk; 884 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 885 struct bt_security sec; 886 struct bt_power pwr; 887 struct l2cap_conn *conn; 888 int len, err = 0; 889 u32 opt; 890 u16 mtu; 891 u8 mode; 892 893 BT_DBG("sk %p", sk); 894 895 if (level == SOL_L2CAP) 896 return l2cap_sock_setsockopt_old(sock, optname, optval, optlen); 897 898 if (level != SOL_BLUETOOTH) 899 return -ENOPROTOOPT; 900 901 lock_sock(sk); 902 903 switch (optname) { 904 case BT_SECURITY: 905 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED && 906 chan->chan_type != L2CAP_CHAN_FIXED && 907 chan->chan_type != L2CAP_CHAN_RAW) { 908 err = -EINVAL; 909 break; 910 } 911 912 sec.level = BT_SECURITY_LOW; 913 914 len = min_t(unsigned int, sizeof(sec), optlen); 915 if (copy_from_sockptr(&sec, optval, len)) { 916 err = -EFAULT; 917 break; 918 } 919 920 if (sec.level < BT_SECURITY_LOW || 921 sec.level > BT_SECURITY_FIPS) { 922 err = -EINVAL; 923 break; 924 } 925 926 chan->sec_level = sec.level; 927 928 if (!chan->conn) 929 break; 930 931 conn = chan->conn; 932 933 /* change security for LE channels */ 934 if (chan->scid == L2CAP_CID_ATT) { 935 if (smp_conn_security(conn->hcon, sec.level)) { 936 err = -EINVAL; 937 break; 938 } 939 940 set_bit(FLAG_PENDING_SECURITY, &chan->flags); 941 sk->sk_state = BT_CONFIG; 942 chan->state = BT_CONFIG; 943 944 /* or for ACL link */ 945 } else if ((sk->sk_state == BT_CONNECT2 && 946 test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags)) || 947 sk->sk_state == BT_CONNECTED) { 948 if (!l2cap_chan_check_security(chan, true)) 949 set_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags); 950 else 951 sk->sk_state_change(sk); 952 } else { 953 err = -EINVAL; 954 } 955 break; 956 957 case BT_DEFER_SETUP: 958 if (sk->sk_state != BT_BOUND && sk->sk_state != BT_LISTEN) { 959 err = -EINVAL; 960 break; 961 } 962 963 if (copy_from_sockptr(&opt, optval, sizeof(u32))) { 964 err = -EFAULT; 965 break; 966 } 967 968 if (opt) { 969 set_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags); 970 set_bit(FLAG_DEFER_SETUP, &chan->flags); 971 } else { 972 clear_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags); 973 clear_bit(FLAG_DEFER_SETUP, &chan->flags); 974 } 975 break; 976 977 case BT_FLUSHABLE: 978 if (copy_from_sockptr(&opt, optval, sizeof(u32))) { 979 err = -EFAULT; 980 break; 981 } 982 983 if (opt > BT_FLUSHABLE_ON) { 984 err = -EINVAL; 985 break; 986 } 987 988 if (opt == BT_FLUSHABLE_OFF) { 989 conn = chan->conn; 990 /* proceed further only when we have l2cap_conn and 991 No Flush support in the LM */ 992 if (!conn || !lmp_no_flush_capable(conn->hcon->hdev)) { 993 err = -EINVAL; 994 break; 995 } 996 } 997 998 if (opt) 999 set_bit(FLAG_FLUSHABLE, &chan->flags); 1000 else 1001 clear_bit(FLAG_FLUSHABLE, &chan->flags); 1002 break; 1003 1004 case BT_POWER: 1005 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED && 1006 chan->chan_type != L2CAP_CHAN_RAW) { 1007 err = -EINVAL; 1008 break; 1009 } 1010 1011 pwr.force_active = BT_POWER_FORCE_ACTIVE_ON; 1012 1013 len = min_t(unsigned int, sizeof(pwr), optlen); 1014 if (copy_from_sockptr(&pwr, optval, len)) { 1015 err = -EFAULT; 1016 break; 1017 } 1018 1019 if (pwr.force_active) 1020 set_bit(FLAG_FORCE_ACTIVE, &chan->flags); 1021 else 1022 clear_bit(FLAG_FORCE_ACTIVE, &chan->flags); 1023 break; 1024 1025 case BT_CHANNEL_POLICY: 1026 if (copy_from_sockptr(&opt, optval, sizeof(u32))) { 1027 err = -EFAULT; 1028 break; 1029 } 1030 1031 err = -EOPNOTSUPP; 1032 break; 1033 1034 case BT_SNDMTU: 1035 if (!bdaddr_type_is_le(chan->src_type)) { 1036 err = -EINVAL; 1037 break; 1038 } 1039 1040 /* Setting is not supported as it's the remote side that 1041 * decides this. 1042 */ 1043 err = -EPERM; 1044 break; 1045 1046 case BT_RCVMTU: 1047 if (!bdaddr_type_is_le(chan->src_type)) { 1048 err = -EINVAL; 1049 break; 1050 } 1051 1052 if (chan->mode == L2CAP_MODE_LE_FLOWCTL && 1053 sk->sk_state == BT_CONNECTED) { 1054 err = -EISCONN; 1055 break; 1056 } 1057 1058 if (copy_from_sockptr(&mtu, optval, sizeof(u16))) { 1059 err = -EFAULT; 1060 break; 1061 } 1062 1063 if (chan->mode == L2CAP_MODE_EXT_FLOWCTL && 1064 sk->sk_state == BT_CONNECTED) 1065 err = l2cap_chan_reconfigure(chan, mtu); 1066 else 1067 chan->imtu = mtu; 1068 1069 break; 1070 1071 case BT_MODE: 1072 if (!enable_ecred) { 1073 err = -ENOPROTOOPT; 1074 break; 1075 } 1076 1077 BT_DBG("sk->sk_state %u", sk->sk_state); 1078 1079 if (sk->sk_state != BT_BOUND) { 1080 err = -EINVAL; 1081 break; 1082 } 1083 1084 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) { 1085 err = -EINVAL; 1086 break; 1087 } 1088 1089 if (copy_from_sockptr(&mode, optval, sizeof(u8))) { 1090 err = -EFAULT; 1091 break; 1092 } 1093 1094 BT_DBG("mode %u", mode); 1095 1096 err = l2cap_set_mode(chan, mode); 1097 if (err) 1098 break; 1099 1100 BT_DBG("mode 0x%2.2x", chan->mode); 1101 1102 break; 1103 1104 default: 1105 err = -ENOPROTOOPT; 1106 break; 1107 } 1108 1109 release_sock(sk); 1110 return err; 1111 } 1112 1113 static int l2cap_sock_sendmsg(struct socket *sock, struct msghdr *msg, 1114 size_t len) 1115 { 1116 struct sock *sk = sock->sk; 1117 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 1118 int err; 1119 1120 BT_DBG("sock %p, sk %p", sock, sk); 1121 1122 err = sock_error(sk); 1123 if (err) 1124 return err; 1125 1126 if (msg->msg_flags & MSG_OOB) 1127 return -EOPNOTSUPP; 1128 1129 if (sk->sk_state != BT_CONNECTED) 1130 return -ENOTCONN; 1131 1132 lock_sock(sk); 1133 err = bt_sock_wait_ready(sk, msg->msg_flags); 1134 release_sock(sk); 1135 if (err) 1136 return err; 1137 1138 l2cap_chan_lock(chan); 1139 err = l2cap_chan_send(chan, msg, len); 1140 l2cap_chan_unlock(chan); 1141 1142 return err; 1143 } 1144 1145 static int l2cap_sock_recvmsg(struct socket *sock, struct msghdr *msg, 1146 size_t len, int flags) 1147 { 1148 struct sock *sk = sock->sk; 1149 struct l2cap_pinfo *pi = l2cap_pi(sk); 1150 int err; 1151 1152 lock_sock(sk); 1153 1154 if (sk->sk_state == BT_CONNECT2 && test_bit(BT_SK_DEFER_SETUP, 1155 &bt_sk(sk)->flags)) { 1156 if (pi->chan->mode == L2CAP_MODE_EXT_FLOWCTL) { 1157 sk->sk_state = BT_CONNECTED; 1158 pi->chan->state = BT_CONNECTED; 1159 __l2cap_ecred_conn_rsp_defer(pi->chan); 1160 } else if (bdaddr_type_is_le(pi->chan->src_type)) { 1161 sk->sk_state = BT_CONNECTED; 1162 pi->chan->state = BT_CONNECTED; 1163 __l2cap_le_connect_rsp_defer(pi->chan); 1164 } else { 1165 sk->sk_state = BT_CONFIG; 1166 pi->chan->state = BT_CONFIG; 1167 __l2cap_connect_rsp_defer(pi->chan); 1168 } 1169 1170 err = 0; 1171 goto done; 1172 } 1173 1174 release_sock(sk); 1175 1176 if (sock->type == SOCK_STREAM) 1177 err = bt_sock_stream_recvmsg(sock, msg, len, flags); 1178 else 1179 err = bt_sock_recvmsg(sock, msg, len, flags); 1180 1181 if (pi->chan->mode != L2CAP_MODE_ERTM) 1182 return err; 1183 1184 /* Attempt to put pending rx data in the socket buffer */ 1185 1186 lock_sock(sk); 1187 1188 if (!test_bit(CONN_LOCAL_BUSY, &pi->chan->conn_state)) 1189 goto done; 1190 1191 if (pi->rx_busy_skb) { 1192 if (!__sock_queue_rcv_skb(sk, pi->rx_busy_skb)) 1193 pi->rx_busy_skb = NULL; 1194 else 1195 goto done; 1196 } 1197 1198 /* Restore data flow when half of the receive buffer is 1199 * available. This avoids resending large numbers of 1200 * frames. 1201 */ 1202 if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf >> 1) 1203 l2cap_chan_busy(pi->chan, 0); 1204 1205 done: 1206 release_sock(sk); 1207 return err; 1208 } 1209 1210 /* Kill socket (only if zapped and orphan) 1211 * Must be called on unlocked socket, with l2cap channel lock. 1212 */ 1213 static void l2cap_sock_kill(struct sock *sk) 1214 { 1215 if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket) 1216 return; 1217 1218 BT_DBG("sk %p state %s", sk, state_to_string(sk->sk_state)); 1219 1220 /* Kill poor orphan */ 1221 1222 l2cap_chan_put(l2cap_pi(sk)->chan); 1223 sock_set_flag(sk, SOCK_DEAD); 1224 sock_put(sk); 1225 } 1226 1227 static int __l2cap_wait_ack(struct sock *sk, struct l2cap_chan *chan) 1228 { 1229 DECLARE_WAITQUEUE(wait, current); 1230 int err = 0; 1231 int timeo = L2CAP_WAIT_ACK_POLL_PERIOD; 1232 /* Timeout to prevent infinite loop */ 1233 unsigned long timeout = jiffies + L2CAP_WAIT_ACK_TIMEOUT; 1234 1235 add_wait_queue(sk_sleep(sk), &wait); 1236 set_current_state(TASK_INTERRUPTIBLE); 1237 do { 1238 BT_DBG("Waiting for %d ACKs, timeout %04d ms", 1239 chan->unacked_frames, time_after(jiffies, timeout) ? 0 : 1240 jiffies_to_msecs(timeout - jiffies)); 1241 1242 if (!timeo) 1243 timeo = L2CAP_WAIT_ACK_POLL_PERIOD; 1244 1245 if (signal_pending(current)) { 1246 err = sock_intr_errno(timeo); 1247 break; 1248 } 1249 1250 release_sock(sk); 1251 timeo = schedule_timeout(timeo); 1252 lock_sock(sk); 1253 set_current_state(TASK_INTERRUPTIBLE); 1254 1255 err = sock_error(sk); 1256 if (err) 1257 break; 1258 1259 if (time_after(jiffies, timeout)) { 1260 err = -ENOLINK; 1261 break; 1262 } 1263 1264 } while (chan->unacked_frames > 0 && 1265 chan->state == BT_CONNECTED); 1266 1267 set_current_state(TASK_RUNNING); 1268 remove_wait_queue(sk_sleep(sk), &wait); 1269 return err; 1270 } 1271 1272 static int l2cap_sock_shutdown(struct socket *sock, int how) 1273 { 1274 struct sock *sk = sock->sk; 1275 struct l2cap_chan *chan; 1276 struct l2cap_conn *conn; 1277 int err = 0; 1278 1279 BT_DBG("sock %p, sk %p, how %d", sock, sk, how); 1280 1281 /* 'how' parameter is mapped to sk_shutdown as follows: 1282 * SHUT_RD (0) --> RCV_SHUTDOWN (1) 1283 * SHUT_WR (1) --> SEND_SHUTDOWN (2) 1284 * SHUT_RDWR (2) --> SHUTDOWN_MASK (3) 1285 */ 1286 how++; 1287 1288 if (!sk) 1289 return 0; 1290 1291 lock_sock(sk); 1292 1293 if ((sk->sk_shutdown & how) == how) 1294 goto shutdown_already; 1295 1296 BT_DBG("Handling sock shutdown"); 1297 1298 /* prevent sk structure from being freed whilst unlocked */ 1299 sock_hold(sk); 1300 1301 chan = l2cap_pi(sk)->chan; 1302 /* prevent chan structure from being freed whilst unlocked */ 1303 l2cap_chan_hold(chan); 1304 1305 BT_DBG("chan %p state %s", chan, state_to_string(chan->state)); 1306 1307 if (chan->mode == L2CAP_MODE_ERTM && 1308 chan->unacked_frames > 0 && 1309 chan->state == BT_CONNECTED) { 1310 err = __l2cap_wait_ack(sk, chan); 1311 1312 /* After waiting for ACKs, check whether shutdown 1313 * has already been actioned to close the L2CAP 1314 * link such as by l2cap_disconnection_req(). 1315 */ 1316 if ((sk->sk_shutdown & how) == how) 1317 goto shutdown_matched; 1318 } 1319 1320 /* Try setting the RCV_SHUTDOWN bit, return early if SEND_SHUTDOWN 1321 * is already set 1322 */ 1323 if ((how & RCV_SHUTDOWN) && !(sk->sk_shutdown & RCV_SHUTDOWN)) { 1324 sk->sk_shutdown |= RCV_SHUTDOWN; 1325 if ((sk->sk_shutdown & how) == how) 1326 goto shutdown_matched; 1327 } 1328 1329 sk->sk_shutdown |= SEND_SHUTDOWN; 1330 release_sock(sk); 1331 1332 l2cap_chan_lock(chan); 1333 conn = chan->conn; 1334 if (conn) 1335 /* prevent conn structure from being freed */ 1336 l2cap_conn_get(conn); 1337 l2cap_chan_unlock(chan); 1338 1339 if (conn) 1340 /* mutex lock must be taken before l2cap_chan_lock() */ 1341 mutex_lock(&conn->chan_lock); 1342 1343 l2cap_chan_lock(chan); 1344 l2cap_chan_close(chan, 0); 1345 l2cap_chan_unlock(chan); 1346 1347 if (conn) { 1348 mutex_unlock(&conn->chan_lock); 1349 l2cap_conn_put(conn); 1350 } 1351 1352 lock_sock(sk); 1353 1354 if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime && 1355 !(current->flags & PF_EXITING)) 1356 err = bt_sock_wait_state(sk, BT_CLOSED, 1357 sk->sk_lingertime); 1358 1359 shutdown_matched: 1360 l2cap_chan_put(chan); 1361 sock_put(sk); 1362 1363 shutdown_already: 1364 if (!err && sk->sk_err) 1365 err = -sk->sk_err; 1366 1367 release_sock(sk); 1368 1369 BT_DBG("Sock shutdown complete err: %d", err); 1370 1371 return err; 1372 } 1373 1374 static int l2cap_sock_release(struct socket *sock) 1375 { 1376 struct sock *sk = sock->sk; 1377 int err; 1378 struct l2cap_chan *chan; 1379 1380 BT_DBG("sock %p, sk %p", sock, sk); 1381 1382 if (!sk) 1383 return 0; 1384 1385 l2cap_sock_cleanup_listen(sk); 1386 bt_sock_unlink(&l2cap_sk_list, sk); 1387 1388 err = l2cap_sock_shutdown(sock, SHUT_RDWR); 1389 chan = l2cap_pi(sk)->chan; 1390 1391 l2cap_chan_hold(chan); 1392 l2cap_chan_lock(chan); 1393 1394 sock_orphan(sk); 1395 l2cap_sock_kill(sk); 1396 1397 l2cap_chan_unlock(chan); 1398 l2cap_chan_put(chan); 1399 1400 return err; 1401 } 1402 1403 static void l2cap_sock_cleanup_listen(struct sock *parent) 1404 { 1405 struct sock *sk; 1406 1407 BT_DBG("parent %p state %s", parent, 1408 state_to_string(parent->sk_state)); 1409 1410 /* Close not yet accepted channels */ 1411 while ((sk = bt_accept_dequeue(parent, NULL))) { 1412 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 1413 1414 BT_DBG("child chan %p state %s", chan, 1415 state_to_string(chan->state)); 1416 1417 l2cap_chan_hold(chan); 1418 l2cap_chan_lock(chan); 1419 1420 __clear_chan_timer(chan); 1421 l2cap_chan_close(chan, ECONNRESET); 1422 l2cap_sock_kill(sk); 1423 1424 l2cap_chan_unlock(chan); 1425 l2cap_chan_put(chan); 1426 } 1427 } 1428 1429 static struct l2cap_chan *l2cap_sock_new_connection_cb(struct l2cap_chan *chan) 1430 { 1431 struct sock *sk, *parent = chan->data; 1432 1433 lock_sock(parent); 1434 1435 /* Check for backlog size */ 1436 if (sk_acceptq_is_full(parent)) { 1437 BT_DBG("backlog full %d", parent->sk_ack_backlog); 1438 release_sock(parent); 1439 return NULL; 1440 } 1441 1442 sk = l2cap_sock_alloc(sock_net(parent), NULL, BTPROTO_L2CAP, 1443 GFP_ATOMIC, 0); 1444 if (!sk) { 1445 release_sock(parent); 1446 return NULL; 1447 } 1448 1449 bt_sock_reclassify_lock(sk, BTPROTO_L2CAP); 1450 1451 l2cap_sock_init(sk, parent); 1452 1453 bt_accept_enqueue(parent, sk, false); 1454 1455 release_sock(parent); 1456 1457 return l2cap_pi(sk)->chan; 1458 } 1459 1460 static int l2cap_sock_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) 1461 { 1462 struct sock *sk = chan->data; 1463 int err; 1464 1465 lock_sock(sk); 1466 1467 if (l2cap_pi(sk)->rx_busy_skb) { 1468 err = -ENOMEM; 1469 goto done; 1470 } 1471 1472 if (chan->mode != L2CAP_MODE_ERTM && 1473 chan->mode != L2CAP_MODE_STREAMING) { 1474 /* Even if no filter is attached, we could potentially 1475 * get errors from security modules, etc. 1476 */ 1477 err = sk_filter(sk, skb); 1478 if (err) 1479 goto done; 1480 } 1481 1482 err = __sock_queue_rcv_skb(sk, skb); 1483 1484 /* For ERTM, handle one skb that doesn't fit into the recv 1485 * buffer. This is important to do because the data frames 1486 * have already been acked, so the skb cannot be discarded. 1487 * 1488 * Notify the l2cap core that the buffer is full, so the 1489 * LOCAL_BUSY state is entered and no more frames are 1490 * acked and reassembled until there is buffer space 1491 * available. 1492 */ 1493 if (err < 0 && chan->mode == L2CAP_MODE_ERTM) { 1494 l2cap_pi(sk)->rx_busy_skb = skb; 1495 l2cap_chan_busy(chan, 1); 1496 err = 0; 1497 } 1498 1499 done: 1500 release_sock(sk); 1501 1502 return err; 1503 } 1504 1505 static void l2cap_sock_close_cb(struct l2cap_chan *chan) 1506 { 1507 struct sock *sk = chan->data; 1508 1509 if (!sk) 1510 return; 1511 1512 l2cap_sock_kill(sk); 1513 } 1514 1515 static void l2cap_sock_teardown_cb(struct l2cap_chan *chan, int err) 1516 { 1517 struct sock *sk = chan->data; 1518 struct sock *parent; 1519 1520 if (!sk) 1521 return; 1522 1523 BT_DBG("chan %p state %s", chan, state_to_string(chan->state)); 1524 1525 /* This callback can be called both for server (BT_LISTEN) 1526 * sockets as well as "normal" ones. To avoid lockdep warnings 1527 * with child socket locking (through l2cap_sock_cleanup_listen) 1528 * we need separation into separate nesting levels. The simplest 1529 * way to accomplish this is to inherit the nesting level used 1530 * for the channel. 1531 */ 1532 lock_sock_nested(sk, atomic_read(&chan->nesting)); 1533 1534 parent = bt_sk(sk)->parent; 1535 1536 switch (chan->state) { 1537 case BT_OPEN: 1538 case BT_BOUND: 1539 case BT_CLOSED: 1540 break; 1541 case BT_LISTEN: 1542 l2cap_sock_cleanup_listen(sk); 1543 sk->sk_state = BT_CLOSED; 1544 chan->state = BT_CLOSED; 1545 1546 break; 1547 default: 1548 sk->sk_state = BT_CLOSED; 1549 chan->state = BT_CLOSED; 1550 1551 sk->sk_err = err; 1552 1553 if (parent) { 1554 bt_accept_unlink(sk); 1555 parent->sk_data_ready(parent); 1556 } else { 1557 sk->sk_state_change(sk); 1558 } 1559 1560 break; 1561 } 1562 release_sock(sk); 1563 1564 /* Only zap after cleanup to avoid use after free race */ 1565 sock_set_flag(sk, SOCK_ZAPPED); 1566 1567 } 1568 1569 static void l2cap_sock_state_change_cb(struct l2cap_chan *chan, int state, 1570 int err) 1571 { 1572 struct sock *sk = chan->data; 1573 1574 sk->sk_state = state; 1575 1576 if (err) 1577 sk->sk_err = err; 1578 } 1579 1580 static struct sk_buff *l2cap_sock_alloc_skb_cb(struct l2cap_chan *chan, 1581 unsigned long hdr_len, 1582 unsigned long len, int nb) 1583 { 1584 struct sock *sk = chan->data; 1585 struct sk_buff *skb; 1586 int err; 1587 1588 l2cap_chan_unlock(chan); 1589 skb = bt_skb_send_alloc(sk, hdr_len + len, nb, &err); 1590 l2cap_chan_lock(chan); 1591 1592 if (!skb) 1593 return ERR_PTR(err); 1594 1595 /* Channel lock is released before requesting new skb and then 1596 * reacquired thus we need to recheck channel state. 1597 */ 1598 if (chan->state != BT_CONNECTED) { 1599 kfree_skb(skb); 1600 return ERR_PTR(-ENOTCONN); 1601 } 1602 1603 skb->priority = READ_ONCE(sk->sk_priority); 1604 1605 bt_cb(skb)->l2cap.chan = chan; 1606 1607 return skb; 1608 } 1609 1610 static void l2cap_sock_ready_cb(struct l2cap_chan *chan) 1611 { 1612 struct sock *sk = chan->data; 1613 struct sock *parent; 1614 1615 lock_sock(sk); 1616 1617 parent = bt_sk(sk)->parent; 1618 1619 BT_DBG("sk %p, parent %p", sk, parent); 1620 1621 sk->sk_state = BT_CONNECTED; 1622 sk->sk_state_change(sk); 1623 1624 if (parent) 1625 parent->sk_data_ready(parent); 1626 1627 release_sock(sk); 1628 } 1629 1630 static void l2cap_sock_defer_cb(struct l2cap_chan *chan) 1631 { 1632 struct sock *parent, *sk = chan->data; 1633 1634 lock_sock(sk); 1635 1636 parent = bt_sk(sk)->parent; 1637 if (parent) 1638 parent->sk_data_ready(parent); 1639 1640 release_sock(sk); 1641 } 1642 1643 static void l2cap_sock_resume_cb(struct l2cap_chan *chan) 1644 { 1645 struct sock *sk = chan->data; 1646 1647 if (test_and_clear_bit(FLAG_PENDING_SECURITY, &chan->flags)) { 1648 sk->sk_state = BT_CONNECTED; 1649 chan->state = BT_CONNECTED; 1650 } 1651 1652 clear_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags); 1653 sk->sk_state_change(sk); 1654 } 1655 1656 static void l2cap_sock_set_shutdown_cb(struct l2cap_chan *chan) 1657 { 1658 struct sock *sk = chan->data; 1659 1660 lock_sock(sk); 1661 sk->sk_shutdown = SHUTDOWN_MASK; 1662 release_sock(sk); 1663 } 1664 1665 static long l2cap_sock_get_sndtimeo_cb(struct l2cap_chan *chan) 1666 { 1667 struct sock *sk = chan->data; 1668 1669 return sk->sk_sndtimeo; 1670 } 1671 1672 static struct pid *l2cap_sock_get_peer_pid_cb(struct l2cap_chan *chan) 1673 { 1674 struct sock *sk = chan->data; 1675 1676 return sk->sk_peer_pid; 1677 } 1678 1679 static void l2cap_sock_suspend_cb(struct l2cap_chan *chan) 1680 { 1681 struct sock *sk = chan->data; 1682 1683 set_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags); 1684 sk->sk_state_change(sk); 1685 } 1686 1687 static int l2cap_sock_filter(struct l2cap_chan *chan, struct sk_buff *skb) 1688 { 1689 struct sock *sk = chan->data; 1690 1691 switch (chan->mode) { 1692 case L2CAP_MODE_ERTM: 1693 case L2CAP_MODE_STREAMING: 1694 return sk_filter(sk, skb); 1695 } 1696 1697 return 0; 1698 } 1699 1700 static const struct l2cap_ops l2cap_chan_ops = { 1701 .name = "L2CAP Socket Interface", 1702 .new_connection = l2cap_sock_new_connection_cb, 1703 .recv = l2cap_sock_recv_cb, 1704 .close = l2cap_sock_close_cb, 1705 .teardown = l2cap_sock_teardown_cb, 1706 .state_change = l2cap_sock_state_change_cb, 1707 .ready = l2cap_sock_ready_cb, 1708 .defer = l2cap_sock_defer_cb, 1709 .resume = l2cap_sock_resume_cb, 1710 .suspend = l2cap_sock_suspend_cb, 1711 .set_shutdown = l2cap_sock_set_shutdown_cb, 1712 .get_sndtimeo = l2cap_sock_get_sndtimeo_cb, 1713 .get_peer_pid = l2cap_sock_get_peer_pid_cb, 1714 .alloc_skb = l2cap_sock_alloc_skb_cb, 1715 .filter = l2cap_sock_filter, 1716 }; 1717 1718 static void l2cap_sock_destruct(struct sock *sk) 1719 { 1720 BT_DBG("sk %p", sk); 1721 1722 if (l2cap_pi(sk)->chan) { 1723 l2cap_pi(sk)->chan->data = NULL; 1724 l2cap_chan_put(l2cap_pi(sk)->chan); 1725 } 1726 1727 if (l2cap_pi(sk)->rx_busy_skb) { 1728 kfree_skb(l2cap_pi(sk)->rx_busy_skb); 1729 l2cap_pi(sk)->rx_busy_skb = NULL; 1730 } 1731 1732 skb_queue_purge(&sk->sk_receive_queue); 1733 skb_queue_purge(&sk->sk_write_queue); 1734 } 1735 1736 static void l2cap_skb_msg_name(struct sk_buff *skb, void *msg_name, 1737 int *msg_namelen) 1738 { 1739 DECLARE_SOCKADDR(struct sockaddr_l2 *, la, msg_name); 1740 1741 memset(la, 0, sizeof(struct sockaddr_l2)); 1742 la->l2_family = AF_BLUETOOTH; 1743 la->l2_psm = bt_cb(skb)->l2cap.psm; 1744 bacpy(&la->l2_bdaddr, &bt_cb(skb)->l2cap.bdaddr); 1745 1746 *msg_namelen = sizeof(struct sockaddr_l2); 1747 } 1748 1749 static void l2cap_sock_init(struct sock *sk, struct sock *parent) 1750 { 1751 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 1752 1753 BT_DBG("sk %p", sk); 1754 1755 if (parent) { 1756 struct l2cap_chan *pchan = l2cap_pi(parent)->chan; 1757 1758 sk->sk_type = parent->sk_type; 1759 bt_sk(sk)->flags = bt_sk(parent)->flags; 1760 1761 chan->chan_type = pchan->chan_type; 1762 chan->imtu = pchan->imtu; 1763 chan->omtu = pchan->omtu; 1764 chan->conf_state = pchan->conf_state; 1765 chan->mode = pchan->mode; 1766 chan->fcs = pchan->fcs; 1767 chan->max_tx = pchan->max_tx; 1768 chan->tx_win = pchan->tx_win; 1769 chan->tx_win_max = pchan->tx_win_max; 1770 chan->sec_level = pchan->sec_level; 1771 chan->flags = pchan->flags; 1772 chan->tx_credits = pchan->tx_credits; 1773 chan->rx_credits = pchan->rx_credits; 1774 1775 if (chan->chan_type == L2CAP_CHAN_FIXED) { 1776 chan->scid = pchan->scid; 1777 chan->dcid = pchan->scid; 1778 } 1779 1780 security_sk_clone(parent, sk); 1781 } else { 1782 switch (sk->sk_type) { 1783 case SOCK_RAW: 1784 chan->chan_type = L2CAP_CHAN_RAW; 1785 break; 1786 case SOCK_DGRAM: 1787 chan->chan_type = L2CAP_CHAN_CONN_LESS; 1788 bt_sk(sk)->skb_msg_name = l2cap_skb_msg_name; 1789 break; 1790 case SOCK_SEQPACKET: 1791 case SOCK_STREAM: 1792 chan->chan_type = L2CAP_CHAN_CONN_ORIENTED; 1793 break; 1794 } 1795 1796 chan->imtu = L2CAP_DEFAULT_MTU; 1797 chan->omtu = 0; 1798 if (!disable_ertm && sk->sk_type == SOCK_STREAM) { 1799 chan->mode = L2CAP_MODE_ERTM; 1800 set_bit(CONF_STATE2_DEVICE, &chan->conf_state); 1801 } else { 1802 chan->mode = L2CAP_MODE_BASIC; 1803 } 1804 1805 l2cap_chan_set_defaults(chan); 1806 } 1807 1808 /* Default config options */ 1809 chan->flush_to = L2CAP_DEFAULT_FLUSH_TO; 1810 1811 chan->data = sk; 1812 chan->ops = &l2cap_chan_ops; 1813 } 1814 1815 static struct proto l2cap_proto = { 1816 .name = "L2CAP", 1817 .owner = THIS_MODULE, 1818 .obj_size = sizeof(struct l2cap_pinfo) 1819 }; 1820 1821 static struct sock *l2cap_sock_alloc(struct net *net, struct socket *sock, 1822 int proto, gfp_t prio, int kern) 1823 { 1824 struct sock *sk; 1825 struct l2cap_chan *chan; 1826 1827 sk = bt_sock_alloc(net, sock, &l2cap_proto, proto, prio, kern); 1828 if (!sk) 1829 return NULL; 1830 1831 sk->sk_destruct = l2cap_sock_destruct; 1832 sk->sk_sndtimeo = L2CAP_CONN_TIMEOUT; 1833 1834 chan = l2cap_chan_create(); 1835 if (!chan) { 1836 sk_free(sk); 1837 return NULL; 1838 } 1839 1840 l2cap_chan_hold(chan); 1841 1842 l2cap_pi(sk)->chan = chan; 1843 1844 return sk; 1845 } 1846 1847 static int l2cap_sock_create(struct net *net, struct socket *sock, int protocol, 1848 int kern) 1849 { 1850 struct sock *sk; 1851 1852 BT_DBG("sock %p", sock); 1853 1854 sock->state = SS_UNCONNECTED; 1855 1856 if (sock->type != SOCK_SEQPACKET && sock->type != SOCK_STREAM && 1857 sock->type != SOCK_DGRAM && sock->type != SOCK_RAW) 1858 return -ESOCKTNOSUPPORT; 1859 1860 if (sock->type == SOCK_RAW && !kern && !capable(CAP_NET_RAW)) 1861 return -EPERM; 1862 1863 sock->ops = &l2cap_sock_ops; 1864 1865 sk = l2cap_sock_alloc(net, sock, protocol, GFP_ATOMIC, kern); 1866 if (!sk) 1867 return -ENOMEM; 1868 1869 l2cap_sock_init(sk, NULL); 1870 bt_sock_link(&l2cap_sk_list, sk); 1871 return 0; 1872 } 1873 1874 static const struct proto_ops l2cap_sock_ops = { 1875 .family = PF_BLUETOOTH, 1876 .owner = THIS_MODULE, 1877 .release = l2cap_sock_release, 1878 .bind = l2cap_sock_bind, 1879 .connect = l2cap_sock_connect, 1880 .listen = l2cap_sock_listen, 1881 .accept = l2cap_sock_accept, 1882 .getname = l2cap_sock_getname, 1883 .sendmsg = l2cap_sock_sendmsg, 1884 .recvmsg = l2cap_sock_recvmsg, 1885 .poll = bt_sock_poll, 1886 .ioctl = bt_sock_ioctl, 1887 .gettstamp = sock_gettstamp, 1888 .mmap = sock_no_mmap, 1889 .socketpair = sock_no_socketpair, 1890 .shutdown = l2cap_sock_shutdown, 1891 .setsockopt = l2cap_sock_setsockopt, 1892 .getsockopt = l2cap_sock_getsockopt 1893 }; 1894 1895 static const struct net_proto_family l2cap_sock_family_ops = { 1896 .family = PF_BLUETOOTH, 1897 .owner = THIS_MODULE, 1898 .create = l2cap_sock_create, 1899 }; 1900 1901 int __init l2cap_init_sockets(void) 1902 { 1903 int err; 1904 1905 BUILD_BUG_ON(sizeof(struct sockaddr_l2) > sizeof(struct sockaddr)); 1906 1907 err = proto_register(&l2cap_proto, 0); 1908 if (err < 0) 1909 return err; 1910 1911 err = bt_sock_register(BTPROTO_L2CAP, &l2cap_sock_family_ops); 1912 if (err < 0) { 1913 BT_ERR("L2CAP socket registration failed"); 1914 goto error; 1915 } 1916 1917 err = bt_procfs_init(&init_net, "l2cap", &l2cap_sk_list, 1918 NULL); 1919 if (err < 0) { 1920 BT_ERR("Failed to create L2CAP proc file"); 1921 bt_sock_unregister(BTPROTO_L2CAP); 1922 goto error; 1923 } 1924 1925 BT_INFO("L2CAP socket layer initialized"); 1926 1927 return 0; 1928 1929 error: 1930 proto_unregister(&l2cap_proto); 1931 return err; 1932 } 1933 1934 void l2cap_cleanup_sockets(void) 1935 { 1936 bt_procfs_cleanup(&init_net, "l2cap"); 1937 bt_sock_unregister(BTPROTO_L2CAP); 1938 proto_unregister(&l2cap_proto); 1939 } 1940