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 READ_ONCE(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 struct proto_accept_arg *arg) 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, arg->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 err = 0; 443 size_t len; 444 u32 opt; 445 446 BT_DBG("sk %p", sk); 447 448 if (get_user(len, optlen)) 449 return -EFAULT; 450 451 lock_sock(sk); 452 453 switch (optname) { 454 case L2CAP_OPTIONS: 455 /* LE sockets should use BT_SNDMTU/BT_RCVMTU, but since 456 * legacy ATT code depends on getsockopt for 457 * L2CAP_OPTIONS we need to let this pass. 458 */ 459 if (bdaddr_type_is_le(chan->src_type) && 460 chan->scid != L2CAP_CID_ATT) { 461 err = -EINVAL; 462 break; 463 } 464 465 /* Only BR/EDR modes are supported here */ 466 switch (chan->mode) { 467 case L2CAP_MODE_BASIC: 468 case L2CAP_MODE_ERTM: 469 case L2CAP_MODE_STREAMING: 470 break; 471 default: 472 err = -EINVAL; 473 break; 474 } 475 476 if (err < 0) 477 break; 478 479 memset(&opts, 0, sizeof(opts)); 480 opts.imtu = chan->imtu; 481 opts.omtu = chan->omtu; 482 opts.flush_to = chan->flush_to; 483 opts.mode = chan->mode; 484 opts.fcs = chan->fcs; 485 opts.max_tx = chan->max_tx; 486 opts.txwin_size = chan->tx_win; 487 488 BT_DBG("mode 0x%2.2x", chan->mode); 489 490 len = min(len, sizeof(opts)); 491 if (copy_to_user(optval, (char *) &opts, len)) 492 err = -EFAULT; 493 494 break; 495 496 case L2CAP_LM: 497 switch (chan->sec_level) { 498 case BT_SECURITY_LOW: 499 opt = L2CAP_LM_AUTH; 500 break; 501 case BT_SECURITY_MEDIUM: 502 opt = L2CAP_LM_AUTH | L2CAP_LM_ENCRYPT; 503 break; 504 case BT_SECURITY_HIGH: 505 opt = L2CAP_LM_AUTH | L2CAP_LM_ENCRYPT | 506 L2CAP_LM_SECURE; 507 break; 508 case BT_SECURITY_FIPS: 509 opt = L2CAP_LM_AUTH | L2CAP_LM_ENCRYPT | 510 L2CAP_LM_SECURE | L2CAP_LM_FIPS; 511 break; 512 default: 513 opt = 0; 514 break; 515 } 516 517 if (test_bit(FLAG_ROLE_SWITCH, &chan->flags)) 518 opt |= L2CAP_LM_MASTER; 519 520 if (test_bit(FLAG_FORCE_RELIABLE, &chan->flags)) 521 opt |= L2CAP_LM_RELIABLE; 522 523 if (put_user(opt, (u32 __user *) optval)) 524 err = -EFAULT; 525 526 break; 527 528 case L2CAP_CONNINFO: 529 if (sk->sk_state != BT_CONNECTED && 530 !(sk->sk_state == BT_CONNECT2 && 531 test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags))) { 532 err = -ENOTCONN; 533 break; 534 } 535 536 memset(&cinfo, 0, sizeof(cinfo)); 537 cinfo.hci_handle = chan->conn->hcon->handle; 538 memcpy(cinfo.dev_class, chan->conn->hcon->dev_class, 3); 539 540 len = min(len, sizeof(cinfo)); 541 if (copy_to_user(optval, (char *) &cinfo, len)) 542 err = -EFAULT; 543 544 break; 545 546 default: 547 err = -ENOPROTOOPT; 548 break; 549 } 550 551 release_sock(sk); 552 return err; 553 } 554 555 static int l2cap_sock_getsockopt(struct socket *sock, int level, int optname, 556 char __user *optval, int __user *optlen) 557 { 558 struct sock *sk = sock->sk; 559 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 560 struct bt_security sec; 561 struct bt_power pwr; 562 u32 phys; 563 int len, mode, err = 0; 564 565 BT_DBG("sk %p", sk); 566 567 if (level == SOL_L2CAP) 568 return l2cap_sock_getsockopt_old(sock, optname, optval, optlen); 569 570 if (level != SOL_BLUETOOTH) 571 return -ENOPROTOOPT; 572 573 if (get_user(len, optlen)) 574 return -EFAULT; 575 576 lock_sock(sk); 577 578 switch (optname) { 579 case BT_SECURITY: 580 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED && 581 chan->chan_type != L2CAP_CHAN_FIXED && 582 chan->chan_type != L2CAP_CHAN_RAW) { 583 err = -EINVAL; 584 break; 585 } 586 587 memset(&sec, 0, sizeof(sec)); 588 if (chan->conn) { 589 sec.level = chan->conn->hcon->sec_level; 590 591 if (sk->sk_state == BT_CONNECTED) 592 sec.key_size = chan->conn->hcon->enc_key_size; 593 } else { 594 sec.level = chan->sec_level; 595 } 596 597 len = min_t(unsigned int, len, sizeof(sec)); 598 if (copy_to_user(optval, (char *) &sec, len)) 599 err = -EFAULT; 600 601 break; 602 603 case BT_DEFER_SETUP: 604 if (sk->sk_state != BT_BOUND && sk->sk_state != BT_LISTEN) { 605 err = -EINVAL; 606 break; 607 } 608 609 if (put_user(test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags), 610 (u32 __user *) optval)) 611 err = -EFAULT; 612 613 break; 614 615 case BT_FLUSHABLE: 616 if (put_user(test_bit(FLAG_FLUSHABLE, &chan->flags), 617 (u32 __user *) optval)) 618 err = -EFAULT; 619 620 break; 621 622 case BT_POWER: 623 if (sk->sk_type != SOCK_SEQPACKET && sk->sk_type != SOCK_STREAM 624 && sk->sk_type != SOCK_RAW) { 625 err = -EINVAL; 626 break; 627 } 628 629 pwr.force_active = test_bit(FLAG_FORCE_ACTIVE, &chan->flags); 630 631 len = min_t(unsigned int, len, sizeof(pwr)); 632 if (copy_to_user(optval, (char *) &pwr, len)) 633 err = -EFAULT; 634 635 break; 636 637 case BT_CHANNEL_POLICY: 638 if (put_user(chan->chan_policy, (u32 __user *) optval)) 639 err = -EFAULT; 640 break; 641 642 case BT_SNDMTU: 643 if (!bdaddr_type_is_le(chan->src_type)) { 644 err = -EINVAL; 645 break; 646 } 647 648 if (sk->sk_state != BT_CONNECTED) { 649 err = -ENOTCONN; 650 break; 651 } 652 653 if (put_user(chan->omtu, (u16 __user *) optval)) 654 err = -EFAULT; 655 break; 656 657 case BT_RCVMTU: 658 if (!bdaddr_type_is_le(chan->src_type)) { 659 err = -EINVAL; 660 break; 661 } 662 663 if (put_user(chan->imtu, (u16 __user *) optval)) 664 err = -EFAULT; 665 break; 666 667 case BT_PHY: 668 if (sk->sk_state != BT_CONNECTED) { 669 err = -ENOTCONN; 670 break; 671 } 672 673 phys = hci_conn_get_phy(chan->conn->hcon); 674 675 if (put_user(phys, (u32 __user *) optval)) 676 err = -EFAULT; 677 break; 678 679 case BT_MODE: 680 if (!enable_ecred) { 681 err = -ENOPROTOOPT; 682 break; 683 } 684 685 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) { 686 err = -EINVAL; 687 break; 688 } 689 690 mode = l2cap_get_mode(chan); 691 if (mode < 0) { 692 err = mode; 693 break; 694 } 695 696 if (put_user(mode, (u8 __user *) optval)) 697 err = -EFAULT; 698 break; 699 700 default: 701 err = -ENOPROTOOPT; 702 break; 703 } 704 705 release_sock(sk); 706 return err; 707 } 708 709 static bool l2cap_valid_mtu(struct l2cap_chan *chan, u16 mtu) 710 { 711 switch (chan->scid) { 712 case L2CAP_CID_ATT: 713 if (mtu && mtu < L2CAP_LE_MIN_MTU) 714 return false; 715 break; 716 717 default: 718 if (mtu && mtu < L2CAP_DEFAULT_MIN_MTU) 719 return false; 720 } 721 722 return true; 723 } 724 725 static int l2cap_sock_setsockopt_old(struct socket *sock, int optname, 726 sockptr_t optval, unsigned int optlen) 727 { 728 struct sock *sk = sock->sk; 729 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 730 struct l2cap_options opts; 731 int err = 0; 732 u32 opt; 733 734 BT_DBG("sk %p", sk); 735 736 lock_sock(sk); 737 738 switch (optname) { 739 case L2CAP_OPTIONS: 740 if (bdaddr_type_is_le(chan->src_type)) { 741 err = -EINVAL; 742 break; 743 } 744 745 if (sk->sk_state == BT_CONNECTED) { 746 err = -EINVAL; 747 break; 748 } 749 750 opts.imtu = chan->imtu; 751 opts.omtu = chan->omtu; 752 opts.flush_to = chan->flush_to; 753 opts.mode = chan->mode; 754 opts.fcs = chan->fcs; 755 opts.max_tx = chan->max_tx; 756 opts.txwin_size = chan->tx_win; 757 758 err = copy_safe_from_sockptr(&opts, sizeof(opts), optval, 759 optlen); 760 if (err) 761 break; 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 err = copy_safe_from_sockptr(&opt, sizeof(opt), optval, optlen); 805 if (err) 806 break; 807 808 if (opt & L2CAP_LM_FIPS) { 809 err = -EINVAL; 810 break; 811 } 812 813 if (opt & L2CAP_LM_AUTH) 814 chan->sec_level = BT_SECURITY_LOW; 815 if (opt & L2CAP_LM_ENCRYPT) 816 chan->sec_level = BT_SECURITY_MEDIUM; 817 if (opt & L2CAP_LM_SECURE) 818 chan->sec_level = BT_SECURITY_HIGH; 819 820 if (opt & L2CAP_LM_MASTER) 821 set_bit(FLAG_ROLE_SWITCH, &chan->flags); 822 else 823 clear_bit(FLAG_ROLE_SWITCH, &chan->flags); 824 825 if (opt & L2CAP_LM_RELIABLE) 826 set_bit(FLAG_FORCE_RELIABLE, &chan->flags); 827 else 828 clear_bit(FLAG_FORCE_RELIABLE, &chan->flags); 829 break; 830 831 default: 832 err = -ENOPROTOOPT; 833 break; 834 } 835 836 release_sock(sk); 837 return err; 838 } 839 840 static int l2cap_set_mode(struct l2cap_chan *chan, u8 mode) 841 { 842 switch (mode) { 843 case BT_MODE_BASIC: 844 if (bdaddr_type_is_le(chan->src_type)) 845 return -EINVAL; 846 mode = L2CAP_MODE_BASIC; 847 clear_bit(CONF_STATE2_DEVICE, &chan->conf_state); 848 break; 849 case BT_MODE_ERTM: 850 if (!disable_ertm || bdaddr_type_is_le(chan->src_type)) 851 return -EINVAL; 852 mode = L2CAP_MODE_ERTM; 853 break; 854 case BT_MODE_STREAMING: 855 if (!disable_ertm || bdaddr_type_is_le(chan->src_type)) 856 return -EINVAL; 857 mode = L2CAP_MODE_STREAMING; 858 break; 859 case BT_MODE_LE_FLOWCTL: 860 if (!bdaddr_type_is_le(chan->src_type)) 861 return -EINVAL; 862 mode = L2CAP_MODE_LE_FLOWCTL; 863 break; 864 case BT_MODE_EXT_FLOWCTL: 865 /* TODO: Add support for ECRED PDUs to BR/EDR */ 866 if (!bdaddr_type_is_le(chan->src_type)) 867 return -EINVAL; 868 mode = L2CAP_MODE_EXT_FLOWCTL; 869 break; 870 default: 871 return -EINVAL; 872 } 873 874 chan->mode = mode; 875 876 return 0; 877 } 878 879 static int l2cap_sock_setsockopt(struct socket *sock, int level, int optname, 880 sockptr_t optval, unsigned int optlen) 881 { 882 struct sock *sk = sock->sk; 883 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 884 struct bt_security sec; 885 struct bt_power pwr; 886 struct l2cap_conn *conn; 887 int err = 0; 888 u32 opt; 889 u16 mtu; 890 u8 mode; 891 892 BT_DBG("sk %p", sk); 893 894 if (level == SOL_L2CAP) 895 return l2cap_sock_setsockopt_old(sock, optname, optval, optlen); 896 897 if (level != SOL_BLUETOOTH) 898 return -ENOPROTOOPT; 899 900 lock_sock(sk); 901 902 switch (optname) { 903 case BT_SECURITY: 904 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED && 905 chan->chan_type != L2CAP_CHAN_FIXED && 906 chan->chan_type != L2CAP_CHAN_RAW) { 907 err = -EINVAL; 908 break; 909 } 910 911 sec.level = BT_SECURITY_LOW; 912 913 err = copy_safe_from_sockptr(&sec, sizeof(sec), optval, optlen); 914 if (err) 915 break; 916 917 if (sec.level < BT_SECURITY_LOW || 918 sec.level > BT_SECURITY_FIPS) { 919 err = -EINVAL; 920 break; 921 } 922 923 chan->sec_level = sec.level; 924 925 if (!chan->conn) 926 break; 927 928 conn = chan->conn; 929 930 /* change security for LE channels */ 931 if (chan->scid == L2CAP_CID_ATT) { 932 if (smp_conn_security(conn->hcon, sec.level)) { 933 err = -EINVAL; 934 break; 935 } 936 937 set_bit(FLAG_PENDING_SECURITY, &chan->flags); 938 sk->sk_state = BT_CONFIG; 939 chan->state = BT_CONFIG; 940 941 /* or for ACL link */ 942 } else if ((sk->sk_state == BT_CONNECT2 && 943 test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags)) || 944 sk->sk_state == BT_CONNECTED) { 945 if (!l2cap_chan_check_security(chan, true)) 946 set_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags); 947 else 948 sk->sk_state_change(sk); 949 } else { 950 err = -EINVAL; 951 } 952 break; 953 954 case BT_DEFER_SETUP: 955 if (sk->sk_state != BT_BOUND && sk->sk_state != BT_LISTEN) { 956 err = -EINVAL; 957 break; 958 } 959 960 err = copy_safe_from_sockptr(&opt, sizeof(opt), optval, optlen); 961 if (err) 962 break; 963 964 if (opt) { 965 set_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags); 966 set_bit(FLAG_DEFER_SETUP, &chan->flags); 967 } else { 968 clear_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags); 969 clear_bit(FLAG_DEFER_SETUP, &chan->flags); 970 } 971 break; 972 973 case BT_FLUSHABLE: 974 err = copy_safe_from_sockptr(&opt, sizeof(opt), optval, optlen); 975 if (err) 976 break; 977 978 if (opt > BT_FLUSHABLE_ON) { 979 err = -EINVAL; 980 break; 981 } 982 983 if (opt == BT_FLUSHABLE_OFF) { 984 conn = chan->conn; 985 /* proceed further only when we have l2cap_conn and 986 No Flush support in the LM */ 987 if (!conn || !lmp_no_flush_capable(conn->hcon->hdev)) { 988 err = -EINVAL; 989 break; 990 } 991 } 992 993 if (opt) 994 set_bit(FLAG_FLUSHABLE, &chan->flags); 995 else 996 clear_bit(FLAG_FLUSHABLE, &chan->flags); 997 break; 998 999 case BT_POWER: 1000 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED && 1001 chan->chan_type != L2CAP_CHAN_RAW) { 1002 err = -EINVAL; 1003 break; 1004 } 1005 1006 pwr.force_active = BT_POWER_FORCE_ACTIVE_ON; 1007 1008 err = copy_safe_from_sockptr(&pwr, sizeof(pwr), optval, optlen); 1009 if (err) 1010 break; 1011 1012 if (pwr.force_active) 1013 set_bit(FLAG_FORCE_ACTIVE, &chan->flags); 1014 else 1015 clear_bit(FLAG_FORCE_ACTIVE, &chan->flags); 1016 break; 1017 1018 case BT_CHANNEL_POLICY: 1019 err = copy_safe_from_sockptr(&opt, sizeof(opt), optval, optlen); 1020 if (err) 1021 break; 1022 1023 err = -EOPNOTSUPP; 1024 break; 1025 1026 case BT_SNDMTU: 1027 if (!bdaddr_type_is_le(chan->src_type)) { 1028 err = -EINVAL; 1029 break; 1030 } 1031 1032 /* Setting is not supported as it's the remote side that 1033 * decides this. 1034 */ 1035 err = -EPERM; 1036 break; 1037 1038 case BT_RCVMTU: 1039 if (!bdaddr_type_is_le(chan->src_type)) { 1040 err = -EINVAL; 1041 break; 1042 } 1043 1044 if (chan->mode == L2CAP_MODE_LE_FLOWCTL && 1045 sk->sk_state == BT_CONNECTED) { 1046 err = -EISCONN; 1047 break; 1048 } 1049 1050 err = copy_safe_from_sockptr(&mtu, sizeof(mtu), optval, optlen); 1051 if (err) 1052 break; 1053 1054 if (chan->mode == L2CAP_MODE_EXT_FLOWCTL && 1055 sk->sk_state == BT_CONNECTED) 1056 err = l2cap_chan_reconfigure(chan, mtu); 1057 else 1058 chan->imtu = mtu; 1059 1060 break; 1061 1062 case BT_MODE: 1063 if (!enable_ecred) { 1064 err = -ENOPROTOOPT; 1065 break; 1066 } 1067 1068 BT_DBG("sk->sk_state %u", sk->sk_state); 1069 1070 if (sk->sk_state != BT_BOUND) { 1071 err = -EINVAL; 1072 break; 1073 } 1074 1075 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) { 1076 err = -EINVAL; 1077 break; 1078 } 1079 1080 err = copy_safe_from_sockptr(&mode, sizeof(mode), optval, 1081 optlen); 1082 if (err) 1083 break; 1084 1085 BT_DBG("mode %u", mode); 1086 1087 err = l2cap_set_mode(chan, mode); 1088 if (err) 1089 break; 1090 1091 BT_DBG("mode 0x%2.2x", chan->mode); 1092 1093 break; 1094 1095 default: 1096 err = -ENOPROTOOPT; 1097 break; 1098 } 1099 1100 release_sock(sk); 1101 return err; 1102 } 1103 1104 static int l2cap_sock_sendmsg(struct socket *sock, struct msghdr *msg, 1105 size_t len) 1106 { 1107 struct sock *sk = sock->sk; 1108 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 1109 struct sockcm_cookie sockc; 1110 int err; 1111 1112 BT_DBG("sock %p, sk %p", sock, sk); 1113 1114 err = sock_error(sk); 1115 if (err) 1116 return err; 1117 1118 if (msg->msg_flags & MSG_OOB) 1119 return -EOPNOTSUPP; 1120 1121 if (sk->sk_state != BT_CONNECTED) 1122 return -ENOTCONN; 1123 1124 hci_sockcm_init(&sockc, sk); 1125 1126 if (msg->msg_controllen) { 1127 err = sock_cmsg_send(sk, msg, &sockc); 1128 if (err) 1129 return err; 1130 } 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, &sockc); 1140 l2cap_chan_unlock(chan); 1141 1142 return err; 1143 } 1144 1145 static void l2cap_publish_rx_avail(struct l2cap_chan *chan) 1146 { 1147 struct sock *sk = chan->data; 1148 ssize_t avail = sk->sk_rcvbuf - atomic_read(&sk->sk_rmem_alloc); 1149 int expected_skbs, skb_overhead; 1150 1151 if (avail <= 0) { 1152 l2cap_chan_rx_avail(chan, 0); 1153 return; 1154 } 1155 1156 if (!chan->mps) { 1157 l2cap_chan_rx_avail(chan, -1); 1158 return; 1159 } 1160 1161 /* Correct available memory by estimated sk_buff overhead. 1162 * This is significant due to small transfer sizes. However, accept 1163 * at least one full packet if receive space is non-zero. 1164 */ 1165 expected_skbs = DIV_ROUND_UP(avail, chan->mps); 1166 skb_overhead = expected_skbs * sizeof(struct sk_buff); 1167 if (skb_overhead < avail) 1168 l2cap_chan_rx_avail(chan, avail - skb_overhead); 1169 else 1170 l2cap_chan_rx_avail(chan, -1); 1171 } 1172 1173 static int l2cap_sock_recvmsg(struct socket *sock, struct msghdr *msg, 1174 size_t len, int flags) 1175 { 1176 struct sock *sk = sock->sk; 1177 struct l2cap_pinfo *pi = l2cap_pi(sk); 1178 int err; 1179 1180 if (unlikely(flags & MSG_ERRQUEUE)) 1181 return sock_recv_errqueue(sk, msg, len, SOL_BLUETOOTH, 1182 BT_SCM_ERROR); 1183 1184 lock_sock(sk); 1185 1186 if (sk->sk_state == BT_CONNECT2 && test_bit(BT_SK_DEFER_SETUP, 1187 &bt_sk(sk)->flags)) { 1188 if (pi->chan->mode == L2CAP_MODE_EXT_FLOWCTL) { 1189 sk->sk_state = BT_CONNECTED; 1190 pi->chan->state = BT_CONNECTED; 1191 __l2cap_ecred_conn_rsp_defer(pi->chan); 1192 } else if (bdaddr_type_is_le(pi->chan->src_type)) { 1193 sk->sk_state = BT_CONNECTED; 1194 pi->chan->state = BT_CONNECTED; 1195 __l2cap_le_connect_rsp_defer(pi->chan); 1196 } else { 1197 sk->sk_state = BT_CONFIG; 1198 pi->chan->state = BT_CONFIG; 1199 __l2cap_connect_rsp_defer(pi->chan); 1200 } 1201 1202 err = 0; 1203 goto done; 1204 } 1205 1206 release_sock(sk); 1207 1208 if (sock->type == SOCK_STREAM) 1209 err = bt_sock_stream_recvmsg(sock, msg, len, flags); 1210 else 1211 err = bt_sock_recvmsg(sock, msg, len, flags); 1212 1213 if (pi->chan->mode != L2CAP_MODE_ERTM && 1214 pi->chan->mode != L2CAP_MODE_LE_FLOWCTL && 1215 pi->chan->mode != L2CAP_MODE_EXT_FLOWCTL) 1216 return err; 1217 1218 lock_sock(sk); 1219 1220 l2cap_publish_rx_avail(pi->chan); 1221 1222 /* Attempt to put pending rx data in the socket buffer */ 1223 while (!list_empty(&pi->rx_busy)) { 1224 struct l2cap_rx_busy *rx_busy = 1225 list_first_entry(&pi->rx_busy, 1226 struct l2cap_rx_busy, 1227 list); 1228 if (__sock_queue_rcv_skb(sk, rx_busy->skb) < 0) 1229 goto done; 1230 list_del(&rx_busy->list); 1231 kfree(rx_busy); 1232 } 1233 1234 /* Restore data flow when half of the receive buffer is 1235 * available. This avoids resending large numbers of 1236 * frames. 1237 */ 1238 if (test_bit(CONN_LOCAL_BUSY, &pi->chan->conn_state) && 1239 atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf >> 1) 1240 l2cap_chan_busy(pi->chan, 0); 1241 1242 done: 1243 release_sock(sk); 1244 return err; 1245 } 1246 1247 /* Kill socket (only if zapped and orphan) 1248 * Must be called on unlocked socket, with l2cap channel lock. 1249 */ 1250 static void l2cap_sock_kill(struct sock *sk) 1251 { 1252 if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket) 1253 return; 1254 1255 BT_DBG("sk %p state %s", sk, state_to_string(sk->sk_state)); 1256 1257 /* Sock is dead, so set chan data to NULL, avoid other task use invalid 1258 * sock pointer. 1259 */ 1260 l2cap_pi(sk)->chan->data = NULL; 1261 /* Kill poor orphan */ 1262 1263 l2cap_chan_put(l2cap_pi(sk)->chan); 1264 sock_set_flag(sk, SOCK_DEAD); 1265 sock_put(sk); 1266 } 1267 1268 static int __l2cap_wait_ack(struct sock *sk, struct l2cap_chan *chan) 1269 { 1270 DECLARE_WAITQUEUE(wait, current); 1271 int err = 0; 1272 int timeo = L2CAP_WAIT_ACK_POLL_PERIOD; 1273 /* Timeout to prevent infinite loop */ 1274 unsigned long timeout = jiffies + L2CAP_WAIT_ACK_TIMEOUT; 1275 1276 add_wait_queue(sk_sleep(sk), &wait); 1277 set_current_state(TASK_INTERRUPTIBLE); 1278 do { 1279 BT_DBG("Waiting for %d ACKs, timeout %04d ms", 1280 chan->unacked_frames, time_after(jiffies, timeout) ? 0 : 1281 jiffies_to_msecs(timeout - jiffies)); 1282 1283 if (!timeo) 1284 timeo = L2CAP_WAIT_ACK_POLL_PERIOD; 1285 1286 if (signal_pending(current)) { 1287 err = sock_intr_errno(timeo); 1288 break; 1289 } 1290 1291 release_sock(sk); 1292 timeo = schedule_timeout(timeo); 1293 lock_sock(sk); 1294 set_current_state(TASK_INTERRUPTIBLE); 1295 1296 err = sock_error(sk); 1297 if (err) 1298 break; 1299 1300 if (time_after(jiffies, timeout)) { 1301 err = -ENOLINK; 1302 break; 1303 } 1304 1305 } while (chan->unacked_frames > 0 && 1306 chan->state == BT_CONNECTED); 1307 1308 set_current_state(TASK_RUNNING); 1309 remove_wait_queue(sk_sleep(sk), &wait); 1310 return err; 1311 } 1312 1313 static int l2cap_sock_shutdown(struct socket *sock, int how) 1314 { 1315 struct sock *sk = sock->sk; 1316 struct l2cap_chan *chan; 1317 struct l2cap_conn *conn; 1318 int err = 0; 1319 1320 BT_DBG("sock %p, sk %p, how %d", sock, sk, how); 1321 1322 /* 'how' parameter is mapped to sk_shutdown as follows: 1323 * SHUT_RD (0) --> RCV_SHUTDOWN (1) 1324 * SHUT_WR (1) --> SEND_SHUTDOWN (2) 1325 * SHUT_RDWR (2) --> SHUTDOWN_MASK (3) 1326 */ 1327 how++; 1328 1329 if (!sk) 1330 return 0; 1331 1332 lock_sock(sk); 1333 1334 if ((sk->sk_shutdown & how) == how) 1335 goto shutdown_already; 1336 1337 BT_DBG("Handling sock shutdown"); 1338 1339 /* prevent sk structure from being freed whilst unlocked */ 1340 sock_hold(sk); 1341 1342 /* prevent chan structure from being freed whilst unlocked */ 1343 chan = l2cap_chan_hold_unless_zero(l2cap_pi(sk)->chan); 1344 if (!chan) 1345 goto shutdown_already; 1346 1347 BT_DBG("chan %p state %s", chan, state_to_string(chan->state)); 1348 1349 if (chan->mode == L2CAP_MODE_ERTM && 1350 chan->unacked_frames > 0 && 1351 chan->state == BT_CONNECTED) { 1352 err = __l2cap_wait_ack(sk, chan); 1353 1354 /* After waiting for ACKs, check whether shutdown 1355 * has already been actioned to close the L2CAP 1356 * link such as by l2cap_disconnection_req(). 1357 */ 1358 if ((sk->sk_shutdown & how) == how) 1359 goto shutdown_matched; 1360 } 1361 1362 /* Try setting the RCV_SHUTDOWN bit, return early if SEND_SHUTDOWN 1363 * is already set 1364 */ 1365 if ((how & RCV_SHUTDOWN) && !(sk->sk_shutdown & RCV_SHUTDOWN)) { 1366 sk->sk_shutdown |= RCV_SHUTDOWN; 1367 if ((sk->sk_shutdown & how) == how) 1368 goto shutdown_matched; 1369 } 1370 1371 sk->sk_shutdown |= SEND_SHUTDOWN; 1372 release_sock(sk); 1373 1374 l2cap_chan_lock(chan); 1375 /* prevent conn structure from being freed */ 1376 conn = l2cap_conn_hold_unless_zero(chan->conn); 1377 l2cap_chan_unlock(chan); 1378 1379 if (conn) 1380 /* mutex lock must be taken before l2cap_chan_lock() */ 1381 mutex_lock(&conn->lock); 1382 1383 l2cap_chan_lock(chan); 1384 l2cap_chan_close(chan, 0); 1385 l2cap_chan_unlock(chan); 1386 1387 if (conn) { 1388 mutex_unlock(&conn->lock); 1389 l2cap_conn_put(conn); 1390 } 1391 1392 lock_sock(sk); 1393 1394 if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime && 1395 !(current->flags & PF_EXITING)) 1396 err = bt_sock_wait_state(sk, BT_CLOSED, 1397 sk->sk_lingertime); 1398 1399 shutdown_matched: 1400 l2cap_chan_put(chan); 1401 sock_put(sk); 1402 1403 shutdown_already: 1404 if (!err && sk->sk_err) 1405 err = -sk->sk_err; 1406 1407 release_sock(sk); 1408 1409 BT_DBG("Sock shutdown complete err: %d", err); 1410 1411 return err; 1412 } 1413 1414 static int l2cap_sock_release(struct socket *sock) 1415 { 1416 struct sock *sk = sock->sk; 1417 int err; 1418 struct l2cap_chan *chan; 1419 1420 BT_DBG("sock %p, sk %p", sock, sk); 1421 1422 if (!sk) 1423 return 0; 1424 1425 lock_sock_nested(sk, L2CAP_NESTING_PARENT); 1426 l2cap_sock_cleanup_listen(sk); 1427 release_sock(sk); 1428 1429 bt_sock_unlink(&l2cap_sk_list, sk); 1430 1431 err = l2cap_sock_shutdown(sock, SHUT_RDWR); 1432 chan = l2cap_pi(sk)->chan; 1433 1434 l2cap_chan_hold(chan); 1435 l2cap_chan_lock(chan); 1436 1437 sock_orphan(sk); 1438 l2cap_sock_kill(sk); 1439 1440 l2cap_chan_unlock(chan); 1441 l2cap_chan_put(chan); 1442 1443 return err; 1444 } 1445 1446 static void l2cap_sock_cleanup_listen(struct sock *parent) 1447 { 1448 struct sock *sk; 1449 1450 BT_DBG("parent %p state %s", parent, 1451 state_to_string(parent->sk_state)); 1452 1453 /* Close not yet accepted channels */ 1454 while ((sk = bt_accept_dequeue(parent, NULL))) { 1455 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 1456 1457 BT_DBG("child chan %p state %s", chan, 1458 state_to_string(chan->state)); 1459 1460 l2cap_chan_hold(chan); 1461 l2cap_chan_lock(chan); 1462 1463 __clear_chan_timer(chan); 1464 l2cap_chan_close(chan, ECONNRESET); 1465 l2cap_sock_kill(sk); 1466 1467 l2cap_chan_unlock(chan); 1468 l2cap_chan_put(chan); 1469 } 1470 } 1471 1472 static struct l2cap_chan *l2cap_sock_new_connection_cb(struct l2cap_chan *chan) 1473 { 1474 struct sock *sk, *parent = chan->data; 1475 1476 lock_sock(parent); 1477 1478 /* Check for backlog size */ 1479 if (sk_acceptq_is_full(parent)) { 1480 BT_DBG("backlog full %d", parent->sk_ack_backlog); 1481 release_sock(parent); 1482 return NULL; 1483 } 1484 1485 sk = l2cap_sock_alloc(sock_net(parent), NULL, BTPROTO_L2CAP, 1486 GFP_ATOMIC, 0); 1487 if (!sk) { 1488 release_sock(parent); 1489 return NULL; 1490 } 1491 1492 bt_sock_reclassify_lock(sk, BTPROTO_L2CAP); 1493 1494 l2cap_sock_init(sk, parent); 1495 1496 bt_accept_enqueue(parent, sk, false); 1497 1498 release_sock(parent); 1499 1500 return l2cap_pi(sk)->chan; 1501 } 1502 1503 static int l2cap_sock_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) 1504 { 1505 struct sock *sk; 1506 struct l2cap_pinfo *pi; 1507 int err; 1508 1509 sk = chan->data; 1510 if (!sk) 1511 return -ENXIO; 1512 1513 pi = l2cap_pi(sk); 1514 lock_sock(sk); 1515 if (chan->mode == L2CAP_MODE_ERTM && !list_empty(&pi->rx_busy)) { 1516 err = -ENOMEM; 1517 goto done; 1518 } 1519 1520 if (chan->mode != L2CAP_MODE_ERTM && 1521 chan->mode != L2CAP_MODE_STREAMING && 1522 chan->mode != L2CAP_MODE_LE_FLOWCTL && 1523 chan->mode != L2CAP_MODE_EXT_FLOWCTL) { 1524 /* Even if no filter is attached, we could potentially 1525 * get errors from security modules, etc. 1526 */ 1527 err = sk_filter(sk, skb); 1528 if (err) 1529 goto done; 1530 } 1531 1532 err = __sock_queue_rcv_skb(sk, skb); 1533 1534 l2cap_publish_rx_avail(chan); 1535 1536 /* For ERTM and LE, handle a skb that doesn't fit into the recv 1537 * buffer. This is important to do because the data frames 1538 * have already been acked, so the skb cannot be discarded. 1539 * 1540 * Notify the l2cap core that the buffer is full, so the 1541 * LOCAL_BUSY state is entered and no more frames are 1542 * acked and reassembled until there is buffer space 1543 * available. 1544 */ 1545 if (err < 0 && 1546 (chan->mode == L2CAP_MODE_ERTM || 1547 chan->mode == L2CAP_MODE_LE_FLOWCTL || 1548 chan->mode == L2CAP_MODE_EXT_FLOWCTL)) { 1549 struct l2cap_rx_busy *rx_busy = 1550 kmalloc(sizeof(*rx_busy), GFP_KERNEL); 1551 if (!rx_busy) { 1552 err = -ENOMEM; 1553 goto done; 1554 } 1555 rx_busy->skb = skb; 1556 list_add_tail(&rx_busy->list, &pi->rx_busy); 1557 l2cap_chan_busy(chan, 1); 1558 err = 0; 1559 } 1560 1561 done: 1562 release_sock(sk); 1563 1564 return err; 1565 } 1566 1567 static void l2cap_sock_close_cb(struct l2cap_chan *chan) 1568 { 1569 struct sock *sk = chan->data; 1570 1571 if (!sk) 1572 return; 1573 1574 l2cap_sock_kill(sk); 1575 } 1576 1577 static void l2cap_sock_teardown_cb(struct l2cap_chan *chan, int err) 1578 { 1579 struct sock *sk = chan->data; 1580 struct sock *parent; 1581 1582 if (!sk) 1583 return; 1584 1585 BT_DBG("chan %p state %s", chan, state_to_string(chan->state)); 1586 1587 /* This callback can be called both for server (BT_LISTEN) 1588 * sockets as well as "normal" ones. To avoid lockdep warnings 1589 * with child socket locking (through l2cap_sock_cleanup_listen) 1590 * we need separation into separate nesting levels. The simplest 1591 * way to accomplish this is to inherit the nesting level used 1592 * for the channel. 1593 */ 1594 lock_sock_nested(sk, atomic_read(&chan->nesting)); 1595 1596 parent = bt_sk(sk)->parent; 1597 1598 switch (chan->state) { 1599 case BT_OPEN: 1600 case BT_BOUND: 1601 case BT_CLOSED: 1602 break; 1603 case BT_LISTEN: 1604 l2cap_sock_cleanup_listen(sk); 1605 sk->sk_state = BT_CLOSED; 1606 chan->state = BT_CLOSED; 1607 1608 break; 1609 default: 1610 sk->sk_state = BT_CLOSED; 1611 chan->state = BT_CLOSED; 1612 1613 sk->sk_err = err; 1614 1615 if (parent) { 1616 bt_accept_unlink(sk); 1617 parent->sk_data_ready(parent); 1618 } else { 1619 sk->sk_state_change(sk); 1620 } 1621 1622 break; 1623 } 1624 release_sock(sk); 1625 1626 /* Only zap after cleanup to avoid use after free race */ 1627 sock_set_flag(sk, SOCK_ZAPPED); 1628 1629 } 1630 1631 static void l2cap_sock_state_change_cb(struct l2cap_chan *chan, int state, 1632 int err) 1633 { 1634 struct sock *sk = chan->data; 1635 1636 sk->sk_state = state; 1637 1638 if (err) 1639 sk->sk_err = err; 1640 } 1641 1642 static struct sk_buff *l2cap_sock_alloc_skb_cb(struct l2cap_chan *chan, 1643 unsigned long hdr_len, 1644 unsigned long len, int nb) 1645 { 1646 struct sock *sk = chan->data; 1647 struct sk_buff *skb; 1648 int err; 1649 1650 l2cap_chan_unlock(chan); 1651 skb = bt_skb_send_alloc(sk, hdr_len + len, nb, &err); 1652 l2cap_chan_lock(chan); 1653 1654 if (!skb) 1655 return ERR_PTR(err); 1656 1657 /* Channel lock is released before requesting new skb and then 1658 * reacquired thus we need to recheck channel state. 1659 */ 1660 if (chan->state != BT_CONNECTED) { 1661 kfree_skb(skb); 1662 return ERR_PTR(-ENOTCONN); 1663 } 1664 1665 skb->priority = READ_ONCE(sk->sk_priority); 1666 1667 bt_cb(skb)->l2cap.chan = chan; 1668 1669 return skb; 1670 } 1671 1672 static void l2cap_sock_ready_cb(struct l2cap_chan *chan) 1673 { 1674 struct sock *sk = chan->data; 1675 struct sock *parent; 1676 1677 lock_sock(sk); 1678 1679 parent = bt_sk(sk)->parent; 1680 1681 BT_DBG("sk %p, parent %p", sk, parent); 1682 1683 sk->sk_state = BT_CONNECTED; 1684 sk->sk_state_change(sk); 1685 1686 if (parent) 1687 parent->sk_data_ready(parent); 1688 1689 release_sock(sk); 1690 } 1691 1692 static void l2cap_sock_defer_cb(struct l2cap_chan *chan) 1693 { 1694 struct sock *parent, *sk = chan->data; 1695 1696 lock_sock(sk); 1697 1698 parent = bt_sk(sk)->parent; 1699 if (parent) 1700 parent->sk_data_ready(parent); 1701 1702 release_sock(sk); 1703 } 1704 1705 static void l2cap_sock_resume_cb(struct l2cap_chan *chan) 1706 { 1707 struct sock *sk = chan->data; 1708 1709 if (!sk) 1710 return; 1711 1712 if (test_and_clear_bit(FLAG_PENDING_SECURITY, &chan->flags)) { 1713 sk->sk_state = BT_CONNECTED; 1714 chan->state = BT_CONNECTED; 1715 } 1716 1717 clear_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags); 1718 sk->sk_state_change(sk); 1719 } 1720 1721 static void l2cap_sock_set_shutdown_cb(struct l2cap_chan *chan) 1722 { 1723 struct sock *sk = chan->data; 1724 1725 lock_sock(sk); 1726 sk->sk_shutdown = SHUTDOWN_MASK; 1727 release_sock(sk); 1728 } 1729 1730 static long l2cap_sock_get_sndtimeo_cb(struct l2cap_chan *chan) 1731 { 1732 struct sock *sk = chan->data; 1733 1734 return READ_ONCE(sk->sk_sndtimeo); 1735 } 1736 1737 static struct pid *l2cap_sock_get_peer_pid_cb(struct l2cap_chan *chan) 1738 { 1739 struct sock *sk = chan->data; 1740 1741 return sk->sk_peer_pid; 1742 } 1743 1744 static void l2cap_sock_suspend_cb(struct l2cap_chan *chan) 1745 { 1746 struct sock *sk = chan->data; 1747 1748 set_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags); 1749 sk->sk_state_change(sk); 1750 } 1751 1752 static int l2cap_sock_filter(struct l2cap_chan *chan, struct sk_buff *skb) 1753 { 1754 struct sock *sk = chan->data; 1755 1756 switch (chan->mode) { 1757 case L2CAP_MODE_ERTM: 1758 case L2CAP_MODE_STREAMING: 1759 return sk_filter(sk, skb); 1760 } 1761 1762 return 0; 1763 } 1764 1765 static const struct l2cap_ops l2cap_chan_ops = { 1766 .name = "L2CAP Socket Interface", 1767 .new_connection = l2cap_sock_new_connection_cb, 1768 .recv = l2cap_sock_recv_cb, 1769 .close = l2cap_sock_close_cb, 1770 .teardown = l2cap_sock_teardown_cb, 1771 .state_change = l2cap_sock_state_change_cb, 1772 .ready = l2cap_sock_ready_cb, 1773 .defer = l2cap_sock_defer_cb, 1774 .resume = l2cap_sock_resume_cb, 1775 .suspend = l2cap_sock_suspend_cb, 1776 .set_shutdown = l2cap_sock_set_shutdown_cb, 1777 .get_sndtimeo = l2cap_sock_get_sndtimeo_cb, 1778 .get_peer_pid = l2cap_sock_get_peer_pid_cb, 1779 .alloc_skb = l2cap_sock_alloc_skb_cb, 1780 .filter = l2cap_sock_filter, 1781 }; 1782 1783 static void l2cap_sock_destruct(struct sock *sk) 1784 { 1785 struct l2cap_rx_busy *rx_busy, *next; 1786 1787 BT_DBG("sk %p", sk); 1788 1789 if (l2cap_pi(sk)->chan) { 1790 l2cap_pi(sk)->chan->data = NULL; 1791 l2cap_chan_put(l2cap_pi(sk)->chan); 1792 } 1793 1794 list_for_each_entry_safe(rx_busy, next, &l2cap_pi(sk)->rx_busy, list) { 1795 kfree_skb(rx_busy->skb); 1796 list_del(&rx_busy->list); 1797 kfree(rx_busy); 1798 } 1799 1800 skb_queue_purge(&sk->sk_receive_queue); 1801 skb_queue_purge(&sk->sk_write_queue); 1802 } 1803 1804 static void l2cap_skb_msg_name(struct sk_buff *skb, void *msg_name, 1805 int *msg_namelen) 1806 { 1807 DECLARE_SOCKADDR(struct sockaddr_l2 *, la, msg_name); 1808 1809 memset(la, 0, sizeof(struct sockaddr_l2)); 1810 la->l2_family = AF_BLUETOOTH; 1811 la->l2_psm = bt_cb(skb)->l2cap.psm; 1812 bacpy(&la->l2_bdaddr, &bt_cb(skb)->l2cap.bdaddr); 1813 1814 *msg_namelen = sizeof(struct sockaddr_l2); 1815 } 1816 1817 static void l2cap_sock_init(struct sock *sk, struct sock *parent) 1818 { 1819 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 1820 1821 BT_DBG("sk %p", sk); 1822 1823 if (parent) { 1824 struct l2cap_chan *pchan = l2cap_pi(parent)->chan; 1825 1826 sk->sk_type = parent->sk_type; 1827 bt_sk(sk)->flags = bt_sk(parent)->flags; 1828 1829 chan->chan_type = pchan->chan_type; 1830 chan->imtu = pchan->imtu; 1831 chan->omtu = pchan->omtu; 1832 chan->conf_state = pchan->conf_state; 1833 chan->mode = pchan->mode; 1834 chan->fcs = pchan->fcs; 1835 chan->max_tx = pchan->max_tx; 1836 chan->tx_win = pchan->tx_win; 1837 chan->tx_win_max = pchan->tx_win_max; 1838 chan->sec_level = pchan->sec_level; 1839 chan->flags = pchan->flags; 1840 chan->tx_credits = pchan->tx_credits; 1841 chan->rx_credits = pchan->rx_credits; 1842 1843 if (chan->chan_type == L2CAP_CHAN_FIXED) { 1844 chan->scid = pchan->scid; 1845 chan->dcid = pchan->scid; 1846 } 1847 1848 security_sk_clone(parent, sk); 1849 } else { 1850 switch (sk->sk_type) { 1851 case SOCK_RAW: 1852 chan->chan_type = L2CAP_CHAN_RAW; 1853 break; 1854 case SOCK_DGRAM: 1855 chan->chan_type = L2CAP_CHAN_CONN_LESS; 1856 bt_sk(sk)->skb_msg_name = l2cap_skb_msg_name; 1857 break; 1858 case SOCK_SEQPACKET: 1859 case SOCK_STREAM: 1860 chan->chan_type = L2CAP_CHAN_CONN_ORIENTED; 1861 break; 1862 } 1863 1864 chan->imtu = L2CAP_DEFAULT_MTU; 1865 chan->omtu = 0; 1866 if (!disable_ertm && sk->sk_type == SOCK_STREAM) { 1867 chan->mode = L2CAP_MODE_ERTM; 1868 set_bit(CONF_STATE2_DEVICE, &chan->conf_state); 1869 } else { 1870 chan->mode = L2CAP_MODE_BASIC; 1871 } 1872 1873 l2cap_chan_set_defaults(chan); 1874 } 1875 1876 /* Default config options */ 1877 chan->flush_to = L2CAP_DEFAULT_FLUSH_TO; 1878 1879 chan->data = sk; 1880 chan->ops = &l2cap_chan_ops; 1881 1882 l2cap_publish_rx_avail(chan); 1883 } 1884 1885 static struct proto l2cap_proto = { 1886 .name = "L2CAP", 1887 .owner = THIS_MODULE, 1888 .obj_size = sizeof(struct l2cap_pinfo) 1889 }; 1890 1891 static struct sock *l2cap_sock_alloc(struct net *net, struct socket *sock, 1892 int proto, gfp_t prio, int kern) 1893 { 1894 struct sock *sk; 1895 struct l2cap_chan *chan; 1896 1897 sk = bt_sock_alloc(net, sock, &l2cap_proto, proto, prio, kern); 1898 if (!sk) 1899 return NULL; 1900 1901 sk->sk_destruct = l2cap_sock_destruct; 1902 sk->sk_sndtimeo = L2CAP_CONN_TIMEOUT; 1903 1904 INIT_LIST_HEAD(&l2cap_pi(sk)->rx_busy); 1905 1906 chan = l2cap_chan_create(); 1907 if (!chan) { 1908 sk_free(sk); 1909 if (sock) 1910 sock->sk = NULL; 1911 return NULL; 1912 } 1913 1914 l2cap_chan_hold(chan); 1915 1916 l2cap_pi(sk)->chan = chan; 1917 1918 return sk; 1919 } 1920 1921 static int l2cap_sock_create(struct net *net, struct socket *sock, int protocol, 1922 int kern) 1923 { 1924 struct sock *sk; 1925 1926 BT_DBG("sock %p", sock); 1927 1928 sock->state = SS_UNCONNECTED; 1929 1930 if (sock->type != SOCK_SEQPACKET && sock->type != SOCK_STREAM && 1931 sock->type != SOCK_DGRAM && sock->type != SOCK_RAW) 1932 return -ESOCKTNOSUPPORT; 1933 1934 if (sock->type == SOCK_RAW && !kern && !capable(CAP_NET_RAW)) 1935 return -EPERM; 1936 1937 sock->ops = &l2cap_sock_ops; 1938 1939 sk = l2cap_sock_alloc(net, sock, protocol, GFP_ATOMIC, kern); 1940 if (!sk) 1941 return -ENOMEM; 1942 1943 l2cap_sock_init(sk, NULL); 1944 bt_sock_link(&l2cap_sk_list, sk); 1945 return 0; 1946 } 1947 1948 static const struct proto_ops l2cap_sock_ops = { 1949 .family = PF_BLUETOOTH, 1950 .owner = THIS_MODULE, 1951 .release = l2cap_sock_release, 1952 .bind = l2cap_sock_bind, 1953 .connect = l2cap_sock_connect, 1954 .listen = l2cap_sock_listen, 1955 .accept = l2cap_sock_accept, 1956 .getname = l2cap_sock_getname, 1957 .sendmsg = l2cap_sock_sendmsg, 1958 .recvmsg = l2cap_sock_recvmsg, 1959 .poll = bt_sock_poll, 1960 .ioctl = bt_sock_ioctl, 1961 .gettstamp = sock_gettstamp, 1962 .mmap = sock_no_mmap, 1963 .socketpair = sock_no_socketpair, 1964 .shutdown = l2cap_sock_shutdown, 1965 .setsockopt = l2cap_sock_setsockopt, 1966 .getsockopt = l2cap_sock_getsockopt 1967 }; 1968 1969 static const struct net_proto_family l2cap_sock_family_ops = { 1970 .family = PF_BLUETOOTH, 1971 .owner = THIS_MODULE, 1972 .create = l2cap_sock_create, 1973 }; 1974 1975 int __init l2cap_init_sockets(void) 1976 { 1977 int err; 1978 1979 BUILD_BUG_ON(sizeof(struct sockaddr_l2) > sizeof(struct sockaddr)); 1980 1981 err = proto_register(&l2cap_proto, 0); 1982 if (err < 0) 1983 return err; 1984 1985 err = bt_sock_register(BTPROTO_L2CAP, &l2cap_sock_family_ops); 1986 if (err < 0) { 1987 BT_ERR("L2CAP socket registration failed"); 1988 goto error; 1989 } 1990 1991 err = bt_procfs_init(&init_net, "l2cap", &l2cap_sk_list, 1992 NULL); 1993 if (err < 0) { 1994 BT_ERR("Failed to create L2CAP proc file"); 1995 bt_sock_unregister(BTPROTO_L2CAP); 1996 goto error; 1997 } 1998 1999 BT_INFO("L2CAP socket layer initialized"); 2000 2001 return 0; 2002 2003 error: 2004 proto_unregister(&l2cap_proto); 2005 return err; 2006 } 2007 2008 void l2cap_cleanup_sockets(void) 2009 { 2010 bt_procfs_cleanup(&init_net, "l2cap"); 2011 bt_sock_unregister(BTPROTO_L2CAP); 2012 proto_unregister(&l2cap_proto); 2013 } 2014