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 && mtu < L2CAP_LE_MIN_MTU) 713 return false; 714 break; 715 716 default: 717 if (mtu && 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 /* prevent chan structure from being freed whilst unlocked */ 1327 chan = l2cap_chan_hold_unless_zero(l2cap_pi(sk)->chan); 1328 if (!chan) 1329 goto shutdown_already; 1330 1331 BT_DBG("chan %p state %s", chan, state_to_string(chan->state)); 1332 1333 if (chan->mode == L2CAP_MODE_ERTM && 1334 chan->unacked_frames > 0 && 1335 chan->state == BT_CONNECTED) { 1336 err = __l2cap_wait_ack(sk, chan); 1337 1338 /* After waiting for ACKs, check whether shutdown 1339 * has already been actioned to close the L2CAP 1340 * link such as by l2cap_disconnection_req(). 1341 */ 1342 if ((sk->sk_shutdown & how) == how) 1343 goto shutdown_matched; 1344 } 1345 1346 /* Try setting the RCV_SHUTDOWN bit, return early if SEND_SHUTDOWN 1347 * is already set 1348 */ 1349 if ((how & RCV_SHUTDOWN) && !(sk->sk_shutdown & RCV_SHUTDOWN)) { 1350 sk->sk_shutdown |= RCV_SHUTDOWN; 1351 if ((sk->sk_shutdown & how) == how) 1352 goto shutdown_matched; 1353 } 1354 1355 sk->sk_shutdown |= SEND_SHUTDOWN; 1356 release_sock(sk); 1357 1358 l2cap_chan_lock(chan); 1359 /* prevent conn structure from being freed */ 1360 conn = l2cap_conn_hold_unless_zero(chan->conn); 1361 l2cap_chan_unlock(chan); 1362 1363 if (conn) 1364 /* mutex lock must be taken before l2cap_chan_lock() */ 1365 mutex_lock(&conn->lock); 1366 1367 l2cap_chan_lock(chan); 1368 l2cap_chan_close(chan, 0); 1369 l2cap_chan_unlock(chan); 1370 1371 if (conn) { 1372 mutex_unlock(&conn->lock); 1373 l2cap_conn_put(conn); 1374 } 1375 1376 lock_sock(sk); 1377 1378 if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime && 1379 !(current->flags & PF_EXITING)) 1380 err = bt_sock_wait_state(sk, BT_CLOSED, 1381 sk->sk_lingertime); 1382 1383 shutdown_matched: 1384 l2cap_chan_put(chan); 1385 sock_put(sk); 1386 1387 shutdown_already: 1388 if (!err && sk->sk_err) 1389 err = -sk->sk_err; 1390 1391 release_sock(sk); 1392 1393 BT_DBG("Sock shutdown complete err: %d", err); 1394 1395 return err; 1396 } 1397 1398 static int l2cap_sock_release(struct socket *sock) 1399 { 1400 struct sock *sk = sock->sk; 1401 int err; 1402 struct l2cap_chan *chan; 1403 1404 BT_DBG("sock %p, sk %p", sock, sk); 1405 1406 if (!sk) 1407 return 0; 1408 1409 l2cap_sock_cleanup_listen(sk); 1410 bt_sock_unlink(&l2cap_sk_list, sk); 1411 1412 err = l2cap_sock_shutdown(sock, SHUT_RDWR); 1413 chan = l2cap_pi(sk)->chan; 1414 1415 l2cap_chan_hold(chan); 1416 l2cap_chan_lock(chan); 1417 1418 sock_orphan(sk); 1419 l2cap_sock_kill(sk); 1420 1421 l2cap_chan_unlock(chan); 1422 l2cap_chan_put(chan); 1423 1424 return err; 1425 } 1426 1427 static void l2cap_sock_cleanup_listen(struct sock *parent) 1428 { 1429 struct sock *sk; 1430 1431 BT_DBG("parent %p state %s", parent, 1432 state_to_string(parent->sk_state)); 1433 1434 /* Close not yet accepted channels */ 1435 while ((sk = bt_accept_dequeue(parent, NULL))) { 1436 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 1437 1438 BT_DBG("child chan %p state %s", chan, 1439 state_to_string(chan->state)); 1440 1441 l2cap_chan_hold(chan); 1442 l2cap_chan_lock(chan); 1443 1444 __clear_chan_timer(chan); 1445 l2cap_chan_close(chan, ECONNRESET); 1446 l2cap_sock_kill(sk); 1447 1448 l2cap_chan_unlock(chan); 1449 l2cap_chan_put(chan); 1450 } 1451 } 1452 1453 static struct l2cap_chan *l2cap_sock_new_connection_cb(struct l2cap_chan *chan) 1454 { 1455 struct sock *sk, *parent = chan->data; 1456 1457 lock_sock(parent); 1458 1459 /* Check for backlog size */ 1460 if (sk_acceptq_is_full(parent)) { 1461 BT_DBG("backlog full %d", parent->sk_ack_backlog); 1462 release_sock(parent); 1463 return NULL; 1464 } 1465 1466 sk = l2cap_sock_alloc(sock_net(parent), NULL, BTPROTO_L2CAP, 1467 GFP_ATOMIC, 0); 1468 if (!sk) { 1469 release_sock(parent); 1470 return NULL; 1471 } 1472 1473 bt_sock_reclassify_lock(sk, BTPROTO_L2CAP); 1474 1475 l2cap_sock_init(sk, parent); 1476 1477 bt_accept_enqueue(parent, sk, false); 1478 1479 release_sock(parent); 1480 1481 return l2cap_pi(sk)->chan; 1482 } 1483 1484 static int l2cap_sock_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) 1485 { 1486 struct sock *sk; 1487 struct l2cap_pinfo *pi; 1488 int err; 1489 1490 sk = chan->data; 1491 if (!sk) 1492 return -ENXIO; 1493 1494 pi = l2cap_pi(sk); 1495 lock_sock(sk); 1496 if (chan->mode == L2CAP_MODE_ERTM && !list_empty(&pi->rx_busy)) { 1497 err = -ENOMEM; 1498 goto done; 1499 } 1500 1501 if (chan->mode != L2CAP_MODE_ERTM && 1502 chan->mode != L2CAP_MODE_STREAMING && 1503 chan->mode != L2CAP_MODE_LE_FLOWCTL && 1504 chan->mode != L2CAP_MODE_EXT_FLOWCTL) { 1505 /* Even if no filter is attached, we could potentially 1506 * get errors from security modules, etc. 1507 */ 1508 err = sk_filter(sk, skb); 1509 if (err) 1510 goto done; 1511 } 1512 1513 err = __sock_queue_rcv_skb(sk, skb); 1514 1515 l2cap_publish_rx_avail(chan); 1516 1517 /* For ERTM and LE, handle a skb that doesn't fit into the recv 1518 * buffer. This is important to do because the data frames 1519 * have already been acked, so the skb cannot be discarded. 1520 * 1521 * Notify the l2cap core that the buffer is full, so the 1522 * LOCAL_BUSY state is entered and no more frames are 1523 * acked and reassembled until there is buffer space 1524 * available. 1525 */ 1526 if (err < 0 && 1527 (chan->mode == L2CAP_MODE_ERTM || 1528 chan->mode == L2CAP_MODE_LE_FLOWCTL || 1529 chan->mode == L2CAP_MODE_EXT_FLOWCTL)) { 1530 struct l2cap_rx_busy *rx_busy = 1531 kmalloc(sizeof(*rx_busy), GFP_KERNEL); 1532 if (!rx_busy) { 1533 err = -ENOMEM; 1534 goto done; 1535 } 1536 rx_busy->skb = skb; 1537 list_add_tail(&rx_busy->list, &pi->rx_busy); 1538 l2cap_chan_busy(chan, 1); 1539 err = 0; 1540 } 1541 1542 done: 1543 release_sock(sk); 1544 1545 return err; 1546 } 1547 1548 static void l2cap_sock_close_cb(struct l2cap_chan *chan) 1549 { 1550 struct sock *sk = chan->data; 1551 1552 if (!sk) 1553 return; 1554 1555 l2cap_sock_kill(sk); 1556 } 1557 1558 static void l2cap_sock_teardown_cb(struct l2cap_chan *chan, int err) 1559 { 1560 struct sock *sk = chan->data; 1561 struct sock *parent; 1562 1563 if (!sk) 1564 return; 1565 1566 BT_DBG("chan %p state %s", chan, state_to_string(chan->state)); 1567 1568 /* This callback can be called both for server (BT_LISTEN) 1569 * sockets as well as "normal" ones. To avoid lockdep warnings 1570 * with child socket locking (through l2cap_sock_cleanup_listen) 1571 * we need separation into separate nesting levels. The simplest 1572 * way to accomplish this is to inherit the nesting level used 1573 * for the channel. 1574 */ 1575 lock_sock_nested(sk, atomic_read(&chan->nesting)); 1576 1577 parent = bt_sk(sk)->parent; 1578 1579 switch (chan->state) { 1580 case BT_OPEN: 1581 case BT_BOUND: 1582 case BT_CLOSED: 1583 break; 1584 case BT_LISTEN: 1585 l2cap_sock_cleanup_listen(sk); 1586 sk->sk_state = BT_CLOSED; 1587 chan->state = BT_CLOSED; 1588 1589 break; 1590 default: 1591 sk->sk_state = BT_CLOSED; 1592 chan->state = BT_CLOSED; 1593 1594 sk->sk_err = err; 1595 1596 if (parent) { 1597 bt_accept_unlink(sk); 1598 parent->sk_data_ready(parent); 1599 } else { 1600 sk->sk_state_change(sk); 1601 } 1602 1603 break; 1604 } 1605 release_sock(sk); 1606 1607 /* Only zap after cleanup to avoid use after free race */ 1608 sock_set_flag(sk, SOCK_ZAPPED); 1609 1610 } 1611 1612 static void l2cap_sock_state_change_cb(struct l2cap_chan *chan, int state, 1613 int err) 1614 { 1615 struct sock *sk = chan->data; 1616 1617 sk->sk_state = state; 1618 1619 if (err) 1620 sk->sk_err = err; 1621 } 1622 1623 static struct sk_buff *l2cap_sock_alloc_skb_cb(struct l2cap_chan *chan, 1624 unsigned long hdr_len, 1625 unsigned long len, int nb) 1626 { 1627 struct sock *sk = chan->data; 1628 struct sk_buff *skb; 1629 int err; 1630 1631 l2cap_chan_unlock(chan); 1632 skb = bt_skb_send_alloc(sk, hdr_len + len, nb, &err); 1633 l2cap_chan_lock(chan); 1634 1635 if (!skb) 1636 return ERR_PTR(err); 1637 1638 /* Channel lock is released before requesting new skb and then 1639 * reacquired thus we need to recheck channel state. 1640 */ 1641 if (chan->state != BT_CONNECTED) { 1642 kfree_skb(skb); 1643 return ERR_PTR(-ENOTCONN); 1644 } 1645 1646 skb->priority = sk->sk_priority; 1647 1648 bt_cb(skb)->l2cap.chan = chan; 1649 1650 return skb; 1651 } 1652 1653 static void l2cap_sock_ready_cb(struct l2cap_chan *chan) 1654 { 1655 struct sock *sk = chan->data; 1656 struct sock *parent; 1657 1658 lock_sock(sk); 1659 1660 parent = bt_sk(sk)->parent; 1661 1662 BT_DBG("sk %p, parent %p", sk, parent); 1663 1664 sk->sk_state = BT_CONNECTED; 1665 sk->sk_state_change(sk); 1666 1667 if (parent) 1668 parent->sk_data_ready(parent); 1669 1670 release_sock(sk); 1671 } 1672 1673 static void l2cap_sock_defer_cb(struct l2cap_chan *chan) 1674 { 1675 struct sock *parent, *sk = chan->data; 1676 1677 lock_sock(sk); 1678 1679 parent = bt_sk(sk)->parent; 1680 if (parent) 1681 parent->sk_data_ready(parent); 1682 1683 release_sock(sk); 1684 } 1685 1686 static void l2cap_sock_resume_cb(struct l2cap_chan *chan) 1687 { 1688 struct sock *sk = chan->data; 1689 1690 if (test_and_clear_bit(FLAG_PENDING_SECURITY, &chan->flags)) { 1691 sk->sk_state = BT_CONNECTED; 1692 chan->state = BT_CONNECTED; 1693 } 1694 1695 clear_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags); 1696 sk->sk_state_change(sk); 1697 } 1698 1699 static void l2cap_sock_set_shutdown_cb(struct l2cap_chan *chan) 1700 { 1701 struct sock *sk = chan->data; 1702 1703 lock_sock(sk); 1704 sk->sk_shutdown = SHUTDOWN_MASK; 1705 release_sock(sk); 1706 } 1707 1708 static long l2cap_sock_get_sndtimeo_cb(struct l2cap_chan *chan) 1709 { 1710 struct sock *sk = chan->data; 1711 1712 return sk->sk_sndtimeo; 1713 } 1714 1715 static struct pid *l2cap_sock_get_peer_pid_cb(struct l2cap_chan *chan) 1716 { 1717 struct sock *sk = chan->data; 1718 1719 return sk->sk_peer_pid; 1720 } 1721 1722 static void l2cap_sock_suspend_cb(struct l2cap_chan *chan) 1723 { 1724 struct sock *sk = chan->data; 1725 1726 set_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags); 1727 sk->sk_state_change(sk); 1728 } 1729 1730 static int l2cap_sock_filter(struct l2cap_chan *chan, struct sk_buff *skb) 1731 { 1732 struct sock *sk = chan->data; 1733 1734 switch (chan->mode) { 1735 case L2CAP_MODE_ERTM: 1736 case L2CAP_MODE_STREAMING: 1737 return sk_filter(sk, skb); 1738 } 1739 1740 return 0; 1741 } 1742 1743 static const struct l2cap_ops l2cap_chan_ops = { 1744 .name = "L2CAP Socket Interface", 1745 .new_connection = l2cap_sock_new_connection_cb, 1746 .recv = l2cap_sock_recv_cb, 1747 .close = l2cap_sock_close_cb, 1748 .teardown = l2cap_sock_teardown_cb, 1749 .state_change = l2cap_sock_state_change_cb, 1750 .ready = l2cap_sock_ready_cb, 1751 .defer = l2cap_sock_defer_cb, 1752 .resume = l2cap_sock_resume_cb, 1753 .suspend = l2cap_sock_suspend_cb, 1754 .set_shutdown = l2cap_sock_set_shutdown_cb, 1755 .get_sndtimeo = l2cap_sock_get_sndtimeo_cb, 1756 .get_peer_pid = l2cap_sock_get_peer_pid_cb, 1757 .alloc_skb = l2cap_sock_alloc_skb_cb, 1758 .filter = l2cap_sock_filter, 1759 }; 1760 1761 static void l2cap_sock_destruct(struct sock *sk) 1762 { 1763 struct l2cap_rx_busy *rx_busy, *next; 1764 1765 BT_DBG("sk %p", sk); 1766 1767 if (l2cap_pi(sk)->chan) { 1768 l2cap_pi(sk)->chan->data = NULL; 1769 l2cap_chan_put(l2cap_pi(sk)->chan); 1770 } 1771 1772 list_for_each_entry_safe(rx_busy, next, &l2cap_pi(sk)->rx_busy, list) { 1773 kfree_skb(rx_busy->skb); 1774 list_del(&rx_busy->list); 1775 kfree(rx_busy); 1776 } 1777 1778 skb_queue_purge(&sk->sk_receive_queue); 1779 skb_queue_purge(&sk->sk_write_queue); 1780 } 1781 1782 static void l2cap_skb_msg_name(struct sk_buff *skb, void *msg_name, 1783 int *msg_namelen) 1784 { 1785 DECLARE_SOCKADDR(struct sockaddr_l2 *, la, msg_name); 1786 1787 memset(la, 0, sizeof(struct sockaddr_l2)); 1788 la->l2_family = AF_BLUETOOTH; 1789 la->l2_psm = bt_cb(skb)->l2cap.psm; 1790 bacpy(&la->l2_bdaddr, &bt_cb(skb)->l2cap.bdaddr); 1791 1792 *msg_namelen = sizeof(struct sockaddr_l2); 1793 } 1794 1795 static void l2cap_sock_init(struct sock *sk, struct sock *parent) 1796 { 1797 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 1798 1799 BT_DBG("sk %p", sk); 1800 1801 if (parent) { 1802 struct l2cap_chan *pchan = l2cap_pi(parent)->chan; 1803 1804 sk->sk_type = parent->sk_type; 1805 bt_sk(sk)->flags = bt_sk(parent)->flags; 1806 1807 chan->chan_type = pchan->chan_type; 1808 chan->imtu = pchan->imtu; 1809 chan->omtu = pchan->omtu; 1810 chan->conf_state = pchan->conf_state; 1811 chan->mode = pchan->mode; 1812 chan->fcs = pchan->fcs; 1813 chan->max_tx = pchan->max_tx; 1814 chan->tx_win = pchan->tx_win; 1815 chan->tx_win_max = pchan->tx_win_max; 1816 chan->sec_level = pchan->sec_level; 1817 chan->flags = pchan->flags; 1818 chan->tx_credits = pchan->tx_credits; 1819 chan->rx_credits = pchan->rx_credits; 1820 1821 if (chan->chan_type == L2CAP_CHAN_FIXED) { 1822 chan->scid = pchan->scid; 1823 chan->dcid = pchan->scid; 1824 } 1825 1826 security_sk_clone(parent, sk); 1827 } else { 1828 switch (sk->sk_type) { 1829 case SOCK_RAW: 1830 chan->chan_type = L2CAP_CHAN_RAW; 1831 break; 1832 case SOCK_DGRAM: 1833 chan->chan_type = L2CAP_CHAN_CONN_LESS; 1834 bt_sk(sk)->skb_msg_name = l2cap_skb_msg_name; 1835 break; 1836 case SOCK_SEQPACKET: 1837 case SOCK_STREAM: 1838 chan->chan_type = L2CAP_CHAN_CONN_ORIENTED; 1839 break; 1840 } 1841 1842 chan->imtu = L2CAP_DEFAULT_MTU; 1843 chan->omtu = 0; 1844 if (!disable_ertm && sk->sk_type == SOCK_STREAM) { 1845 chan->mode = L2CAP_MODE_ERTM; 1846 set_bit(CONF_STATE2_DEVICE, &chan->conf_state); 1847 } else { 1848 chan->mode = L2CAP_MODE_BASIC; 1849 } 1850 1851 l2cap_chan_set_defaults(chan); 1852 } 1853 1854 /* Default config options */ 1855 chan->flush_to = L2CAP_DEFAULT_FLUSH_TO; 1856 1857 chan->data = sk; 1858 chan->ops = &l2cap_chan_ops; 1859 1860 l2cap_publish_rx_avail(chan); 1861 } 1862 1863 static struct proto l2cap_proto = { 1864 .name = "L2CAP", 1865 .owner = THIS_MODULE, 1866 .obj_size = sizeof(struct l2cap_pinfo) 1867 }; 1868 1869 static struct sock *l2cap_sock_alloc(struct net *net, struct socket *sock, 1870 int proto, gfp_t prio, int kern) 1871 { 1872 struct sock *sk; 1873 struct l2cap_chan *chan; 1874 1875 sk = bt_sock_alloc(net, sock, &l2cap_proto, proto, prio, kern); 1876 if (!sk) 1877 return NULL; 1878 1879 sk->sk_destruct = l2cap_sock_destruct; 1880 sk->sk_sndtimeo = L2CAP_CONN_TIMEOUT; 1881 1882 INIT_LIST_HEAD(&l2cap_pi(sk)->rx_busy); 1883 1884 chan = l2cap_chan_create(); 1885 if (!chan) { 1886 sk_free(sk); 1887 if (sock) 1888 sock->sk = NULL; 1889 return NULL; 1890 } 1891 1892 l2cap_chan_hold(chan); 1893 1894 l2cap_pi(sk)->chan = chan; 1895 1896 return sk; 1897 } 1898 1899 static int l2cap_sock_create(struct net *net, struct socket *sock, int protocol, 1900 int kern) 1901 { 1902 struct sock *sk; 1903 1904 BT_DBG("sock %p", sock); 1905 1906 sock->state = SS_UNCONNECTED; 1907 1908 if (sock->type != SOCK_SEQPACKET && sock->type != SOCK_STREAM && 1909 sock->type != SOCK_DGRAM && sock->type != SOCK_RAW) 1910 return -ESOCKTNOSUPPORT; 1911 1912 if (sock->type == SOCK_RAW && !kern && !capable(CAP_NET_RAW)) 1913 return -EPERM; 1914 1915 sock->ops = &l2cap_sock_ops; 1916 1917 sk = l2cap_sock_alloc(net, sock, protocol, GFP_ATOMIC, kern); 1918 if (!sk) 1919 return -ENOMEM; 1920 1921 l2cap_sock_init(sk, NULL); 1922 bt_sock_link(&l2cap_sk_list, sk); 1923 return 0; 1924 } 1925 1926 static const struct proto_ops l2cap_sock_ops = { 1927 .family = PF_BLUETOOTH, 1928 .owner = THIS_MODULE, 1929 .release = l2cap_sock_release, 1930 .bind = l2cap_sock_bind, 1931 .connect = l2cap_sock_connect, 1932 .listen = l2cap_sock_listen, 1933 .accept = l2cap_sock_accept, 1934 .getname = l2cap_sock_getname, 1935 .sendmsg = l2cap_sock_sendmsg, 1936 .recvmsg = l2cap_sock_recvmsg, 1937 .poll = bt_sock_poll, 1938 .ioctl = bt_sock_ioctl, 1939 .gettstamp = sock_gettstamp, 1940 .mmap = sock_no_mmap, 1941 .socketpair = sock_no_socketpair, 1942 .shutdown = l2cap_sock_shutdown, 1943 .setsockopt = l2cap_sock_setsockopt, 1944 .getsockopt = l2cap_sock_getsockopt 1945 }; 1946 1947 static const struct net_proto_family l2cap_sock_family_ops = { 1948 .family = PF_BLUETOOTH, 1949 .owner = THIS_MODULE, 1950 .create = l2cap_sock_create, 1951 }; 1952 1953 int __init l2cap_init_sockets(void) 1954 { 1955 int err; 1956 1957 BUILD_BUG_ON(sizeof(struct sockaddr_l2) > sizeof(struct sockaddr)); 1958 1959 err = proto_register(&l2cap_proto, 0); 1960 if (err < 0) 1961 return err; 1962 1963 err = bt_sock_register(BTPROTO_L2CAP, &l2cap_sock_family_ops); 1964 if (err < 0) { 1965 BT_ERR("L2CAP socket registration failed"); 1966 goto error; 1967 } 1968 1969 err = bt_procfs_init(&init_net, "l2cap", &l2cap_sk_list, 1970 NULL); 1971 if (err < 0) { 1972 BT_ERR("Failed to create L2CAP proc file"); 1973 bt_sock_unregister(BTPROTO_L2CAP); 1974 goto error; 1975 } 1976 1977 BT_INFO("L2CAP socket layer initialized"); 1978 1979 return 0; 1980 1981 error: 1982 proto_unregister(&l2cap_proto); 1983 return err; 1984 } 1985 1986 void l2cap_cleanup_sockets(void) 1987 { 1988 bt_procfs_cleanup(&init_net, "l2cap"); 1989 bt_sock_unregister(BTPROTO_L2CAP); 1990 proto_unregister(&l2cap_proto); 1991 } 1992