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_unsized *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_unsized *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, phys; 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 /* Only allow setting output MTU when not connected */ 1033 if (sk->sk_state == BT_CONNECTED) { 1034 err = -EISCONN; 1035 break; 1036 } 1037 1038 err = copy_safe_from_sockptr(&mtu, sizeof(mtu), optval, optlen); 1039 if (err) 1040 break; 1041 1042 chan->omtu = mtu; 1043 break; 1044 1045 case BT_RCVMTU: 1046 if (!bdaddr_type_is_le(chan->src_type)) { 1047 err = -EINVAL; 1048 break; 1049 } 1050 1051 if (chan->mode == L2CAP_MODE_LE_FLOWCTL && 1052 sk->sk_state == BT_CONNECTED) { 1053 err = -EISCONN; 1054 break; 1055 } 1056 1057 err = copy_safe_from_sockptr(&mtu, sizeof(mtu), optval, optlen); 1058 if (err) 1059 break; 1060 1061 if (chan->mode == L2CAP_MODE_EXT_FLOWCTL && 1062 sk->sk_state == BT_CONNECTED) 1063 err = l2cap_chan_reconfigure(chan, mtu); 1064 else 1065 chan->imtu = mtu; 1066 1067 break; 1068 1069 case BT_PHY: 1070 if (sk->sk_state != BT_CONNECTED) { 1071 err = -ENOTCONN; 1072 break; 1073 } 1074 1075 err = copy_safe_from_sockptr(&phys, sizeof(phys), optval, 1076 optlen); 1077 if (err) 1078 break; 1079 1080 if (!chan->conn) 1081 break; 1082 1083 conn = chan->conn; 1084 err = hci_conn_set_phy(conn->hcon, phys); 1085 break; 1086 1087 case BT_MODE: 1088 if (!enable_ecred) { 1089 err = -ENOPROTOOPT; 1090 break; 1091 } 1092 1093 BT_DBG("sk->sk_state %u", sk->sk_state); 1094 1095 if (sk->sk_state != BT_BOUND) { 1096 err = -EINVAL; 1097 break; 1098 } 1099 1100 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) { 1101 err = -EINVAL; 1102 break; 1103 } 1104 1105 err = copy_safe_from_sockptr(&mode, sizeof(mode), optval, 1106 optlen); 1107 if (err) 1108 break; 1109 1110 BT_DBG("mode %u", mode); 1111 1112 err = l2cap_set_mode(chan, mode); 1113 if (err) 1114 break; 1115 1116 BT_DBG("mode 0x%2.2x", chan->mode); 1117 1118 break; 1119 1120 default: 1121 err = -ENOPROTOOPT; 1122 break; 1123 } 1124 1125 release_sock(sk); 1126 return err; 1127 } 1128 1129 static int l2cap_sock_sendmsg(struct socket *sock, struct msghdr *msg, 1130 size_t len) 1131 { 1132 struct sock *sk = sock->sk; 1133 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 1134 struct sockcm_cookie sockc; 1135 int err; 1136 1137 BT_DBG("sock %p, sk %p", sock, sk); 1138 1139 err = sock_error(sk); 1140 if (err) 1141 return err; 1142 1143 if (msg->msg_flags & MSG_OOB) 1144 return -EOPNOTSUPP; 1145 1146 if (sk->sk_state != BT_CONNECTED) 1147 return -ENOTCONN; 1148 1149 hci_sockcm_init(&sockc, sk); 1150 1151 if (msg->msg_controllen) { 1152 err = sock_cmsg_send(sk, msg, &sockc); 1153 if (err) 1154 return err; 1155 } 1156 1157 lock_sock(sk); 1158 err = bt_sock_wait_ready(sk, msg->msg_flags); 1159 release_sock(sk); 1160 if (err) 1161 return err; 1162 1163 l2cap_chan_lock(chan); 1164 err = l2cap_chan_send(chan, msg, len, &sockc); 1165 l2cap_chan_unlock(chan); 1166 1167 return err; 1168 } 1169 1170 static void l2cap_publish_rx_avail(struct l2cap_chan *chan) 1171 { 1172 struct sock *sk = chan->data; 1173 ssize_t avail = sk->sk_rcvbuf - atomic_read(&sk->sk_rmem_alloc); 1174 int expected_skbs, skb_overhead; 1175 1176 if (avail <= 0) { 1177 l2cap_chan_rx_avail(chan, 0); 1178 return; 1179 } 1180 1181 if (!chan->mps) { 1182 l2cap_chan_rx_avail(chan, -1); 1183 return; 1184 } 1185 1186 /* Correct available memory by estimated sk_buff overhead. 1187 * This is significant due to small transfer sizes. However, accept 1188 * at least one full packet if receive space is non-zero. 1189 */ 1190 expected_skbs = DIV_ROUND_UP(avail, chan->mps); 1191 skb_overhead = expected_skbs * sizeof(struct sk_buff); 1192 if (skb_overhead < avail) 1193 l2cap_chan_rx_avail(chan, avail - skb_overhead); 1194 else 1195 l2cap_chan_rx_avail(chan, -1); 1196 } 1197 1198 static int l2cap_sock_recvmsg(struct socket *sock, struct msghdr *msg, 1199 size_t len, int flags) 1200 { 1201 struct sock *sk = sock->sk; 1202 struct l2cap_pinfo *pi = l2cap_pi(sk); 1203 int err; 1204 1205 if (unlikely(flags & MSG_ERRQUEUE)) 1206 return sock_recv_errqueue(sk, msg, len, SOL_BLUETOOTH, 1207 BT_SCM_ERROR); 1208 1209 lock_sock(sk); 1210 1211 if (sk->sk_state == BT_CONNECT2 && test_bit(BT_SK_DEFER_SETUP, 1212 &bt_sk(sk)->flags)) { 1213 if (pi->chan->mode == L2CAP_MODE_EXT_FLOWCTL) { 1214 sk->sk_state = BT_CONNECTED; 1215 pi->chan->state = BT_CONNECTED; 1216 __l2cap_ecred_conn_rsp_defer(pi->chan); 1217 } else if (bdaddr_type_is_le(pi->chan->src_type)) { 1218 sk->sk_state = BT_CONNECTED; 1219 pi->chan->state = BT_CONNECTED; 1220 __l2cap_le_connect_rsp_defer(pi->chan); 1221 } else { 1222 sk->sk_state = BT_CONFIG; 1223 pi->chan->state = BT_CONFIG; 1224 __l2cap_connect_rsp_defer(pi->chan); 1225 } 1226 1227 err = 0; 1228 goto done; 1229 } 1230 1231 release_sock(sk); 1232 1233 if (sock->type == SOCK_STREAM) 1234 err = bt_sock_stream_recvmsg(sock, msg, len, flags); 1235 else 1236 err = bt_sock_recvmsg(sock, msg, len, flags); 1237 1238 if (pi->chan->mode != L2CAP_MODE_ERTM && 1239 pi->chan->mode != L2CAP_MODE_LE_FLOWCTL && 1240 pi->chan->mode != L2CAP_MODE_EXT_FLOWCTL) 1241 return err; 1242 1243 lock_sock(sk); 1244 1245 l2cap_publish_rx_avail(pi->chan); 1246 1247 /* Attempt to put pending rx data in the socket buffer */ 1248 while (!list_empty(&pi->rx_busy)) { 1249 struct l2cap_rx_busy *rx_busy = 1250 list_first_entry(&pi->rx_busy, 1251 struct l2cap_rx_busy, 1252 list); 1253 if (__sock_queue_rcv_skb(sk, rx_busy->skb) < 0) 1254 goto done; 1255 list_del(&rx_busy->list); 1256 kfree(rx_busy); 1257 } 1258 1259 /* Restore data flow when half of the receive buffer is 1260 * available. This avoids resending large numbers of 1261 * frames. 1262 */ 1263 if (test_bit(CONN_LOCAL_BUSY, &pi->chan->conn_state) && 1264 atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf >> 1) 1265 l2cap_chan_busy(pi->chan, 0); 1266 1267 done: 1268 release_sock(sk); 1269 return err; 1270 } 1271 1272 /* Kill socket (only if zapped and orphan) 1273 * Must be called on unlocked socket, with l2cap channel lock. 1274 */ 1275 static void l2cap_sock_kill(struct sock *sk) 1276 { 1277 if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket) 1278 return; 1279 1280 BT_DBG("sk %p state %s", sk, state_to_string(sk->sk_state)); 1281 1282 /* Sock is dead, so set chan data to NULL, avoid other task use invalid 1283 * sock pointer. 1284 */ 1285 l2cap_pi(sk)->chan->data = NULL; 1286 /* Kill poor orphan */ 1287 1288 l2cap_chan_put(l2cap_pi(sk)->chan); 1289 sock_set_flag(sk, SOCK_DEAD); 1290 sock_put(sk); 1291 } 1292 1293 static int __l2cap_wait_ack(struct sock *sk, struct l2cap_chan *chan) 1294 { 1295 DECLARE_WAITQUEUE(wait, current); 1296 int err = 0; 1297 int timeo = L2CAP_WAIT_ACK_POLL_PERIOD; 1298 /* Timeout to prevent infinite loop */ 1299 unsigned long timeout = jiffies + L2CAP_WAIT_ACK_TIMEOUT; 1300 1301 add_wait_queue(sk_sleep(sk), &wait); 1302 set_current_state(TASK_INTERRUPTIBLE); 1303 do { 1304 BT_DBG("Waiting for %d ACKs, timeout %04d ms", 1305 chan->unacked_frames, time_after(jiffies, timeout) ? 0 : 1306 jiffies_to_msecs(timeout - jiffies)); 1307 1308 if (!timeo) 1309 timeo = L2CAP_WAIT_ACK_POLL_PERIOD; 1310 1311 if (signal_pending(current)) { 1312 err = sock_intr_errno(timeo); 1313 break; 1314 } 1315 1316 release_sock(sk); 1317 timeo = schedule_timeout(timeo); 1318 lock_sock(sk); 1319 set_current_state(TASK_INTERRUPTIBLE); 1320 1321 err = sock_error(sk); 1322 if (err) 1323 break; 1324 1325 if (time_after(jiffies, timeout)) { 1326 err = -ENOLINK; 1327 break; 1328 } 1329 1330 } while (chan->unacked_frames > 0 && 1331 chan->state == BT_CONNECTED); 1332 1333 set_current_state(TASK_RUNNING); 1334 remove_wait_queue(sk_sleep(sk), &wait); 1335 return err; 1336 } 1337 1338 static int l2cap_sock_shutdown(struct socket *sock, int how) 1339 { 1340 struct sock *sk = sock->sk; 1341 struct l2cap_chan *chan; 1342 struct l2cap_conn *conn; 1343 int err = 0; 1344 1345 BT_DBG("sock %p, sk %p, how %d", sock, sk, how); 1346 1347 /* 'how' parameter is mapped to sk_shutdown as follows: 1348 * SHUT_RD (0) --> RCV_SHUTDOWN (1) 1349 * SHUT_WR (1) --> SEND_SHUTDOWN (2) 1350 * SHUT_RDWR (2) --> SHUTDOWN_MASK (3) 1351 */ 1352 how++; 1353 1354 if (!sk) 1355 return 0; 1356 1357 lock_sock(sk); 1358 1359 if ((sk->sk_shutdown & how) == how) 1360 goto shutdown_already; 1361 1362 BT_DBG("Handling sock shutdown"); 1363 1364 /* prevent sk structure from being freed whilst unlocked */ 1365 sock_hold(sk); 1366 1367 /* prevent chan structure from being freed whilst unlocked */ 1368 chan = l2cap_chan_hold_unless_zero(l2cap_pi(sk)->chan); 1369 if (!chan) 1370 goto shutdown_already; 1371 1372 BT_DBG("chan %p state %s", chan, state_to_string(chan->state)); 1373 1374 if (chan->mode == L2CAP_MODE_ERTM && 1375 chan->unacked_frames > 0 && 1376 chan->state == BT_CONNECTED) { 1377 err = __l2cap_wait_ack(sk, chan); 1378 1379 /* After waiting for ACKs, check whether shutdown 1380 * has already been actioned to close the L2CAP 1381 * link such as by l2cap_disconnection_req(). 1382 */ 1383 if ((sk->sk_shutdown & how) == how) 1384 goto shutdown_matched; 1385 } 1386 1387 /* Try setting the RCV_SHUTDOWN bit, return early if SEND_SHUTDOWN 1388 * is already set 1389 */ 1390 if ((how & RCV_SHUTDOWN) && !(sk->sk_shutdown & RCV_SHUTDOWN)) { 1391 sk->sk_shutdown |= RCV_SHUTDOWN; 1392 if ((sk->sk_shutdown & how) == how) 1393 goto shutdown_matched; 1394 } 1395 1396 sk->sk_shutdown |= SEND_SHUTDOWN; 1397 release_sock(sk); 1398 1399 l2cap_chan_lock(chan); 1400 /* prevent conn structure from being freed */ 1401 conn = l2cap_conn_hold_unless_zero(chan->conn); 1402 l2cap_chan_unlock(chan); 1403 1404 if (conn) 1405 /* mutex lock must be taken before l2cap_chan_lock() */ 1406 mutex_lock(&conn->lock); 1407 1408 l2cap_chan_lock(chan); 1409 l2cap_chan_close(chan, 0); 1410 l2cap_chan_unlock(chan); 1411 1412 if (conn) { 1413 mutex_unlock(&conn->lock); 1414 l2cap_conn_put(conn); 1415 } 1416 1417 lock_sock(sk); 1418 1419 if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime && 1420 !(current->flags & PF_EXITING)) 1421 err = bt_sock_wait_state(sk, BT_CLOSED, 1422 sk->sk_lingertime); 1423 1424 shutdown_matched: 1425 l2cap_chan_put(chan); 1426 sock_put(sk); 1427 1428 shutdown_already: 1429 if (!err && sk->sk_err) 1430 err = -sk->sk_err; 1431 1432 release_sock(sk); 1433 1434 BT_DBG("Sock shutdown complete err: %d", err); 1435 1436 return err; 1437 } 1438 1439 static int l2cap_sock_release(struct socket *sock) 1440 { 1441 struct sock *sk = sock->sk; 1442 int err; 1443 struct l2cap_chan *chan; 1444 1445 BT_DBG("sock %p, sk %p", sock, sk); 1446 1447 if (!sk) 1448 return 0; 1449 1450 lock_sock_nested(sk, L2CAP_NESTING_PARENT); 1451 l2cap_sock_cleanup_listen(sk); 1452 release_sock(sk); 1453 1454 bt_sock_unlink(&l2cap_sk_list, sk); 1455 1456 err = l2cap_sock_shutdown(sock, SHUT_RDWR); 1457 chan = l2cap_pi(sk)->chan; 1458 1459 l2cap_chan_hold(chan); 1460 l2cap_chan_lock(chan); 1461 1462 sock_orphan(sk); 1463 l2cap_sock_kill(sk); 1464 1465 l2cap_chan_unlock(chan); 1466 l2cap_chan_put(chan); 1467 1468 return err; 1469 } 1470 1471 static void l2cap_sock_cleanup_listen(struct sock *parent) 1472 { 1473 struct sock *sk; 1474 1475 BT_DBG("parent %p state %s", parent, 1476 state_to_string(parent->sk_state)); 1477 1478 /* Close not yet accepted channels */ 1479 while ((sk = bt_accept_dequeue(parent, NULL))) { 1480 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 1481 1482 BT_DBG("child chan %p state %s", chan, 1483 state_to_string(chan->state)); 1484 1485 l2cap_chan_hold(chan); 1486 l2cap_chan_lock(chan); 1487 1488 __clear_chan_timer(chan); 1489 l2cap_chan_close(chan, ECONNRESET); 1490 l2cap_sock_kill(sk); 1491 1492 l2cap_chan_unlock(chan); 1493 l2cap_chan_put(chan); 1494 } 1495 } 1496 1497 static struct l2cap_chan *l2cap_sock_new_connection_cb(struct l2cap_chan *chan) 1498 { 1499 struct sock *sk, *parent = chan->data; 1500 1501 lock_sock(parent); 1502 1503 /* Check for backlog size */ 1504 if (sk_acceptq_is_full(parent)) { 1505 BT_DBG("backlog full %d", parent->sk_ack_backlog); 1506 release_sock(parent); 1507 return NULL; 1508 } 1509 1510 sk = l2cap_sock_alloc(sock_net(parent), NULL, BTPROTO_L2CAP, 1511 GFP_ATOMIC, 0); 1512 if (!sk) { 1513 release_sock(parent); 1514 return NULL; 1515 } 1516 1517 bt_sock_reclassify_lock(sk, BTPROTO_L2CAP); 1518 1519 l2cap_sock_init(sk, parent); 1520 1521 bt_accept_enqueue(parent, sk, false); 1522 1523 release_sock(parent); 1524 1525 return l2cap_pi(sk)->chan; 1526 } 1527 1528 static int l2cap_sock_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) 1529 { 1530 struct sock *sk; 1531 struct l2cap_pinfo *pi; 1532 int err; 1533 1534 sk = chan->data; 1535 if (!sk) 1536 return -ENXIO; 1537 1538 pi = l2cap_pi(sk); 1539 lock_sock(sk); 1540 if (chan->mode == L2CAP_MODE_ERTM && !list_empty(&pi->rx_busy)) { 1541 err = -ENOMEM; 1542 goto done; 1543 } 1544 1545 if (chan->mode != L2CAP_MODE_ERTM && 1546 chan->mode != L2CAP_MODE_STREAMING && 1547 chan->mode != L2CAP_MODE_LE_FLOWCTL && 1548 chan->mode != L2CAP_MODE_EXT_FLOWCTL) { 1549 /* Even if no filter is attached, we could potentially 1550 * get errors from security modules, etc. 1551 */ 1552 err = sk_filter(sk, skb); 1553 if (err) 1554 goto done; 1555 } 1556 1557 err = __sock_queue_rcv_skb(sk, skb); 1558 1559 l2cap_publish_rx_avail(chan); 1560 1561 /* For ERTM and LE, handle a skb that doesn't fit into the recv 1562 * buffer. This is important to do because the data frames 1563 * have already been acked, so the skb cannot be discarded. 1564 * 1565 * Notify the l2cap core that the buffer is full, so the 1566 * LOCAL_BUSY state is entered and no more frames are 1567 * acked and reassembled until there is buffer space 1568 * available. 1569 */ 1570 if (err < 0 && 1571 (chan->mode == L2CAP_MODE_ERTM || 1572 chan->mode == L2CAP_MODE_LE_FLOWCTL || 1573 chan->mode == L2CAP_MODE_EXT_FLOWCTL)) { 1574 struct l2cap_rx_busy *rx_busy = kmalloc_obj(*rx_busy); 1575 if (!rx_busy) { 1576 err = -ENOMEM; 1577 goto done; 1578 } 1579 rx_busy->skb = skb; 1580 list_add_tail(&rx_busy->list, &pi->rx_busy); 1581 l2cap_chan_busy(chan, 1); 1582 err = 0; 1583 } 1584 1585 done: 1586 release_sock(sk); 1587 1588 return err; 1589 } 1590 1591 static void l2cap_sock_close_cb(struct l2cap_chan *chan) 1592 { 1593 struct sock *sk = chan->data; 1594 1595 if (!sk) 1596 return; 1597 1598 l2cap_sock_kill(sk); 1599 } 1600 1601 static void l2cap_sock_teardown_cb(struct l2cap_chan *chan, int err) 1602 { 1603 struct sock *sk = chan->data; 1604 struct sock *parent; 1605 1606 if (!sk) 1607 return; 1608 1609 BT_DBG("chan %p state %s", chan, state_to_string(chan->state)); 1610 1611 /* This callback can be called both for server (BT_LISTEN) 1612 * sockets as well as "normal" ones. To avoid lockdep warnings 1613 * with child socket locking (through l2cap_sock_cleanup_listen) 1614 * we need separation into separate nesting levels. The simplest 1615 * way to accomplish this is to inherit the nesting level used 1616 * for the channel. 1617 */ 1618 lock_sock_nested(sk, atomic_read(&chan->nesting)); 1619 1620 parent = bt_sk(sk)->parent; 1621 1622 switch (chan->state) { 1623 case BT_OPEN: 1624 case BT_BOUND: 1625 case BT_CLOSED: 1626 break; 1627 case BT_LISTEN: 1628 l2cap_sock_cleanup_listen(sk); 1629 sk->sk_state = BT_CLOSED; 1630 chan->state = BT_CLOSED; 1631 1632 break; 1633 default: 1634 sk->sk_state = BT_CLOSED; 1635 chan->state = BT_CLOSED; 1636 1637 sk->sk_err = err; 1638 1639 if (parent) { 1640 bt_accept_unlink(sk); 1641 parent->sk_data_ready(parent); 1642 } else { 1643 sk->sk_state_change(sk); 1644 } 1645 1646 break; 1647 } 1648 release_sock(sk); 1649 1650 /* Only zap after cleanup to avoid use after free race */ 1651 sock_set_flag(sk, SOCK_ZAPPED); 1652 1653 } 1654 1655 static void l2cap_sock_state_change_cb(struct l2cap_chan *chan, int state, 1656 int err) 1657 { 1658 struct sock *sk = chan->data; 1659 1660 sk->sk_state = state; 1661 1662 if (err) 1663 sk->sk_err = err; 1664 } 1665 1666 static struct sk_buff *l2cap_sock_alloc_skb_cb(struct l2cap_chan *chan, 1667 unsigned long hdr_len, 1668 unsigned long len, int nb) 1669 { 1670 struct sock *sk = chan->data; 1671 struct sk_buff *skb; 1672 int err; 1673 1674 l2cap_chan_unlock(chan); 1675 skb = bt_skb_send_alloc(sk, hdr_len + len, nb, &err); 1676 l2cap_chan_lock(chan); 1677 1678 if (!skb) 1679 return ERR_PTR(err); 1680 1681 /* Channel lock is released before requesting new skb and then 1682 * reacquired thus we need to recheck channel state. 1683 */ 1684 if (chan->state != BT_CONNECTED) { 1685 kfree_skb(skb); 1686 return ERR_PTR(-ENOTCONN); 1687 } 1688 1689 skb->priority = READ_ONCE(sk->sk_priority); 1690 1691 bt_cb(skb)->l2cap.chan = chan; 1692 1693 return skb; 1694 } 1695 1696 static void l2cap_sock_ready_cb(struct l2cap_chan *chan) 1697 { 1698 struct sock *sk = chan->data; 1699 struct sock *parent; 1700 1701 lock_sock(sk); 1702 1703 parent = bt_sk(sk)->parent; 1704 1705 BT_DBG("sk %p, parent %p", sk, parent); 1706 1707 sk->sk_state = BT_CONNECTED; 1708 sk->sk_state_change(sk); 1709 1710 if (parent) 1711 parent->sk_data_ready(parent); 1712 1713 release_sock(sk); 1714 } 1715 1716 static void l2cap_sock_defer_cb(struct l2cap_chan *chan) 1717 { 1718 struct sock *parent, *sk = chan->data; 1719 1720 lock_sock(sk); 1721 1722 parent = bt_sk(sk)->parent; 1723 if (parent) 1724 parent->sk_data_ready(parent); 1725 1726 release_sock(sk); 1727 } 1728 1729 static void l2cap_sock_resume_cb(struct l2cap_chan *chan) 1730 { 1731 struct sock *sk = chan->data; 1732 1733 if (!sk) 1734 return; 1735 1736 if (test_and_clear_bit(FLAG_PENDING_SECURITY, &chan->flags)) { 1737 sk->sk_state = BT_CONNECTED; 1738 chan->state = BT_CONNECTED; 1739 } 1740 1741 clear_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags); 1742 sk->sk_state_change(sk); 1743 } 1744 1745 static void l2cap_sock_set_shutdown_cb(struct l2cap_chan *chan) 1746 { 1747 struct sock *sk = chan->data; 1748 1749 lock_sock(sk); 1750 sk->sk_shutdown = SHUTDOWN_MASK; 1751 release_sock(sk); 1752 } 1753 1754 static long l2cap_sock_get_sndtimeo_cb(struct l2cap_chan *chan) 1755 { 1756 struct sock *sk = chan->data; 1757 1758 return READ_ONCE(sk->sk_sndtimeo); 1759 } 1760 1761 static struct pid *l2cap_sock_get_peer_pid_cb(struct l2cap_chan *chan) 1762 { 1763 struct sock *sk = chan->data; 1764 1765 return sk->sk_peer_pid; 1766 } 1767 1768 static void l2cap_sock_suspend_cb(struct l2cap_chan *chan) 1769 { 1770 struct sock *sk = chan->data; 1771 1772 set_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags); 1773 sk->sk_state_change(sk); 1774 } 1775 1776 static int l2cap_sock_filter(struct l2cap_chan *chan, struct sk_buff *skb) 1777 { 1778 struct sock *sk = chan->data; 1779 1780 switch (chan->mode) { 1781 case L2CAP_MODE_ERTM: 1782 case L2CAP_MODE_STREAMING: 1783 return sk_filter(sk, skb); 1784 } 1785 1786 return 0; 1787 } 1788 1789 static const struct l2cap_ops l2cap_chan_ops = { 1790 .name = "L2CAP Socket Interface", 1791 .new_connection = l2cap_sock_new_connection_cb, 1792 .recv = l2cap_sock_recv_cb, 1793 .close = l2cap_sock_close_cb, 1794 .teardown = l2cap_sock_teardown_cb, 1795 .state_change = l2cap_sock_state_change_cb, 1796 .ready = l2cap_sock_ready_cb, 1797 .defer = l2cap_sock_defer_cb, 1798 .resume = l2cap_sock_resume_cb, 1799 .suspend = l2cap_sock_suspend_cb, 1800 .set_shutdown = l2cap_sock_set_shutdown_cb, 1801 .get_sndtimeo = l2cap_sock_get_sndtimeo_cb, 1802 .get_peer_pid = l2cap_sock_get_peer_pid_cb, 1803 .alloc_skb = l2cap_sock_alloc_skb_cb, 1804 .filter = l2cap_sock_filter, 1805 }; 1806 1807 static void l2cap_sock_destruct(struct sock *sk) 1808 { 1809 struct l2cap_rx_busy *rx_busy, *next; 1810 1811 BT_DBG("sk %p", sk); 1812 1813 if (l2cap_pi(sk)->chan) { 1814 l2cap_pi(sk)->chan->data = NULL; 1815 l2cap_chan_put(l2cap_pi(sk)->chan); 1816 } 1817 1818 list_for_each_entry_safe(rx_busy, next, &l2cap_pi(sk)->rx_busy, list) { 1819 kfree_skb(rx_busy->skb); 1820 list_del(&rx_busy->list); 1821 kfree(rx_busy); 1822 } 1823 1824 skb_queue_purge(&sk->sk_receive_queue); 1825 skb_queue_purge(&sk->sk_write_queue); 1826 skb_queue_purge(&sk->sk_error_queue); 1827 } 1828 1829 static void l2cap_skb_msg_name(struct sk_buff *skb, void *msg_name, 1830 int *msg_namelen) 1831 { 1832 DECLARE_SOCKADDR(struct sockaddr_l2 *, la, msg_name); 1833 1834 memset(la, 0, sizeof(struct sockaddr_l2)); 1835 la->l2_family = AF_BLUETOOTH; 1836 la->l2_psm = bt_cb(skb)->l2cap.psm; 1837 bacpy(&la->l2_bdaddr, &bt_cb(skb)->l2cap.bdaddr); 1838 1839 *msg_namelen = sizeof(struct sockaddr_l2); 1840 } 1841 1842 static void l2cap_sock_init(struct sock *sk, struct sock *parent) 1843 { 1844 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 1845 1846 BT_DBG("sk %p", sk); 1847 1848 if (parent) { 1849 struct l2cap_chan *pchan = l2cap_pi(parent)->chan; 1850 1851 sk->sk_type = parent->sk_type; 1852 bt_sk(sk)->flags = bt_sk(parent)->flags; 1853 1854 chan->chan_type = pchan->chan_type; 1855 chan->imtu = pchan->imtu; 1856 chan->omtu = pchan->omtu; 1857 chan->conf_state = pchan->conf_state; 1858 chan->mode = pchan->mode; 1859 chan->fcs = pchan->fcs; 1860 chan->max_tx = pchan->max_tx; 1861 chan->tx_win = pchan->tx_win; 1862 chan->tx_win_max = pchan->tx_win_max; 1863 chan->sec_level = pchan->sec_level; 1864 chan->flags = pchan->flags; 1865 chan->tx_credits = pchan->tx_credits; 1866 chan->rx_credits = pchan->rx_credits; 1867 1868 if (chan->chan_type == L2CAP_CHAN_FIXED) { 1869 chan->scid = pchan->scid; 1870 chan->dcid = pchan->scid; 1871 } 1872 1873 security_sk_clone(parent, sk); 1874 } else { 1875 switch (sk->sk_type) { 1876 case SOCK_RAW: 1877 chan->chan_type = L2CAP_CHAN_RAW; 1878 break; 1879 case SOCK_DGRAM: 1880 chan->chan_type = L2CAP_CHAN_CONN_LESS; 1881 bt_sk(sk)->skb_msg_name = l2cap_skb_msg_name; 1882 break; 1883 case SOCK_SEQPACKET: 1884 case SOCK_STREAM: 1885 chan->chan_type = L2CAP_CHAN_CONN_ORIENTED; 1886 break; 1887 } 1888 1889 chan->imtu = L2CAP_DEFAULT_MTU; 1890 chan->omtu = 0; 1891 if (!disable_ertm && sk->sk_type == SOCK_STREAM) { 1892 chan->mode = L2CAP_MODE_ERTM; 1893 set_bit(CONF_STATE2_DEVICE, &chan->conf_state); 1894 } else { 1895 chan->mode = L2CAP_MODE_BASIC; 1896 } 1897 1898 l2cap_chan_set_defaults(chan); 1899 } 1900 1901 /* Default config options */ 1902 chan->flush_to = L2CAP_DEFAULT_FLUSH_TO; 1903 1904 chan->data = sk; 1905 chan->ops = &l2cap_chan_ops; 1906 1907 l2cap_publish_rx_avail(chan); 1908 } 1909 1910 static struct proto l2cap_proto = { 1911 .name = "L2CAP", 1912 .owner = THIS_MODULE, 1913 .obj_size = sizeof(struct l2cap_pinfo) 1914 }; 1915 1916 static struct sock *l2cap_sock_alloc(struct net *net, struct socket *sock, 1917 int proto, gfp_t prio, int kern) 1918 { 1919 struct sock *sk; 1920 struct l2cap_chan *chan; 1921 1922 sk = bt_sock_alloc(net, sock, &l2cap_proto, proto, prio, kern); 1923 if (!sk) 1924 return NULL; 1925 1926 sk->sk_destruct = l2cap_sock_destruct; 1927 sk->sk_sndtimeo = L2CAP_CONN_TIMEOUT; 1928 1929 INIT_LIST_HEAD(&l2cap_pi(sk)->rx_busy); 1930 1931 chan = l2cap_chan_create(); 1932 if (!chan) { 1933 sk_free(sk); 1934 if (sock) 1935 sock->sk = NULL; 1936 return NULL; 1937 } 1938 1939 l2cap_chan_hold(chan); 1940 1941 l2cap_pi(sk)->chan = chan; 1942 1943 return sk; 1944 } 1945 1946 static int l2cap_sock_create(struct net *net, struct socket *sock, int protocol, 1947 int kern) 1948 { 1949 struct sock *sk; 1950 1951 BT_DBG("sock %p", sock); 1952 1953 sock->state = SS_UNCONNECTED; 1954 1955 if (sock->type != SOCK_SEQPACKET && sock->type != SOCK_STREAM && 1956 sock->type != SOCK_DGRAM && sock->type != SOCK_RAW) 1957 return -ESOCKTNOSUPPORT; 1958 1959 if (sock->type == SOCK_RAW && !kern && !capable(CAP_NET_RAW)) 1960 return -EPERM; 1961 1962 sock->ops = &l2cap_sock_ops; 1963 1964 sk = l2cap_sock_alloc(net, sock, protocol, GFP_ATOMIC, kern); 1965 if (!sk) 1966 return -ENOMEM; 1967 1968 l2cap_sock_init(sk, NULL); 1969 bt_sock_link(&l2cap_sk_list, sk); 1970 return 0; 1971 } 1972 1973 static const struct proto_ops l2cap_sock_ops = { 1974 .family = PF_BLUETOOTH, 1975 .owner = THIS_MODULE, 1976 .release = l2cap_sock_release, 1977 .bind = l2cap_sock_bind, 1978 .connect = l2cap_sock_connect, 1979 .listen = l2cap_sock_listen, 1980 .accept = l2cap_sock_accept, 1981 .getname = l2cap_sock_getname, 1982 .sendmsg = l2cap_sock_sendmsg, 1983 .recvmsg = l2cap_sock_recvmsg, 1984 .poll = bt_sock_poll, 1985 .ioctl = bt_sock_ioctl, 1986 .gettstamp = sock_gettstamp, 1987 .mmap = sock_no_mmap, 1988 .socketpair = sock_no_socketpair, 1989 .shutdown = l2cap_sock_shutdown, 1990 .setsockopt = l2cap_sock_setsockopt, 1991 .getsockopt = l2cap_sock_getsockopt 1992 }; 1993 1994 static const struct net_proto_family l2cap_sock_family_ops = { 1995 .family = PF_BLUETOOTH, 1996 .owner = THIS_MODULE, 1997 .create = l2cap_sock_create, 1998 }; 1999 2000 int __init l2cap_init_sockets(void) 2001 { 2002 int err; 2003 2004 BUILD_BUG_ON(sizeof(struct sockaddr_l2) > sizeof(struct sockaddr)); 2005 2006 err = proto_register(&l2cap_proto, 0); 2007 if (err < 0) 2008 return err; 2009 2010 err = bt_sock_register(BTPROTO_L2CAP, &l2cap_sock_family_ops); 2011 if (err < 0) { 2012 BT_ERR("L2CAP socket registration failed"); 2013 goto error; 2014 } 2015 2016 err = bt_procfs_init(&init_net, "l2cap", &l2cap_sk_list, 2017 NULL); 2018 if (err < 0) { 2019 BT_ERR("Failed to create L2CAP proc file"); 2020 bt_sock_unregister(BTPROTO_L2CAP); 2021 goto error; 2022 } 2023 2024 BT_INFO("L2CAP socket layer initialized"); 2025 2026 return 0; 2027 2028 error: 2029 proto_unregister(&l2cap_proto); 2030 return err; 2031 } 2032 2033 void l2cap_cleanup_sockets(void) 2034 { 2035 bt_procfs_cleanup(&init_net, "l2cap"); 2036 bt_sock_unregister(BTPROTO_L2CAP); 2037 proto_unregister(&l2cap_proto); 2038 } 2039