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