1 /* 2 BlueZ - Bluetooth protocol stack for Linux 3 Copyright (C) 2000-2001 Qualcomm Incorporated 4 Copyright (C) 2009-2010 Gustavo F. Padovan <gustavo@padovan.org> 5 Copyright (C) 2010 Google Inc. 6 Copyright (C) 2011 ProFUSION Embedded Systems 7 8 Written 2000,2001 by Maxim Krasnyansky <maxk@qualcomm.com> 9 10 This program is free software; you can redistribute it and/or modify 11 it under the terms of the GNU General Public License version 2 as 12 published by the Free Software Foundation; 13 14 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 15 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 16 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. 17 IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY 18 CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES 19 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 20 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 21 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 22 23 ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS, 24 COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS 25 SOFTWARE IS DISCLAIMED. 26 */ 27 28 /* Bluetooth L2CAP sockets. */ 29 30 #include <linux/module.h> 31 #include <linux/export.h> 32 #include <linux/filter.h> 33 #include <linux/sched/signal.h> 34 35 #include <net/bluetooth/bluetooth.h> 36 #include <net/bluetooth/hci_core.h> 37 #include <net/bluetooth/l2cap.h> 38 39 #include "smp.h" 40 41 static struct bt_sock_list l2cap_sk_list = { 42 .lock = __RW_LOCK_UNLOCKED(l2cap_sk_list.lock) 43 }; 44 45 static const struct proto_ops l2cap_sock_ops; 46 static void l2cap_sock_init(struct sock *sk, struct sock *parent); 47 static struct sock *l2cap_sock_alloc(struct net *net, struct socket *sock, 48 int proto, gfp_t prio, int kern); 49 static void l2cap_sock_cleanup_listen(struct sock *parent); 50 51 bool l2cap_is_socket(struct socket *sock) 52 { 53 return sock && sock->ops == &l2cap_sock_ops; 54 } 55 EXPORT_SYMBOL(l2cap_is_socket); 56 57 static int l2cap_validate_bredr_psm(u16 psm) 58 { 59 /* PSM must be odd and lsb of upper byte must be 0 */ 60 if ((psm & 0x0101) != 0x0001) 61 return -EINVAL; 62 63 /* Restrict usage of well-known PSMs */ 64 if (psm < L2CAP_PSM_DYN_START && !capable(CAP_NET_BIND_SERVICE)) 65 return -EACCES; 66 67 return 0; 68 } 69 70 static int l2cap_validate_le_psm(u16 psm) 71 { 72 /* Valid LE_PSM ranges are defined only until 0x00ff */ 73 if (psm > L2CAP_PSM_LE_DYN_END) 74 return -EINVAL; 75 76 /* Restrict fixed, SIG assigned PSM values to CAP_NET_BIND_SERVICE */ 77 if (psm < L2CAP_PSM_LE_DYN_START && !capable(CAP_NET_BIND_SERVICE)) 78 return -EACCES; 79 80 return 0; 81 } 82 83 static int l2cap_sock_bind(struct socket *sock, struct sockaddr *addr, int alen) 84 { 85 struct sock *sk = sock->sk; 86 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 87 struct sockaddr_l2 la; 88 int len, err = 0; 89 90 BT_DBG("sk %p", sk); 91 92 if (!addr || alen < offsetofend(struct sockaddr, sa_family) || 93 addr->sa_family != AF_BLUETOOTH) 94 return -EINVAL; 95 96 memset(&la, 0, sizeof(la)); 97 len = min_t(unsigned int, sizeof(la), alen); 98 memcpy(&la, addr, len); 99 100 if (la.l2_cid && la.l2_psm) 101 return -EINVAL; 102 103 if (!bdaddr_type_is_valid(la.l2_bdaddr_type)) 104 return -EINVAL; 105 106 if (bdaddr_type_is_le(la.l2_bdaddr_type)) { 107 /* We only allow ATT user space socket */ 108 if (la.l2_cid && 109 la.l2_cid != cpu_to_le16(L2CAP_CID_ATT)) 110 return -EINVAL; 111 } 112 113 lock_sock(sk); 114 115 if (sk->sk_state != BT_OPEN) { 116 err = -EBADFD; 117 goto done; 118 } 119 120 if (la.l2_psm) { 121 __u16 psm = __le16_to_cpu(la.l2_psm); 122 123 if (la.l2_bdaddr_type == BDADDR_BREDR) 124 err = l2cap_validate_bredr_psm(psm); 125 else 126 err = l2cap_validate_le_psm(psm); 127 128 if (err) 129 goto done; 130 } 131 132 bacpy(&chan->src, &la.l2_bdaddr); 133 chan->src_type = la.l2_bdaddr_type; 134 135 if (la.l2_cid) 136 err = l2cap_add_scid(chan, __le16_to_cpu(la.l2_cid)); 137 else 138 err = l2cap_add_psm(chan, &la.l2_bdaddr, la.l2_psm); 139 140 if (err < 0) 141 goto done; 142 143 switch (chan->chan_type) { 144 case L2CAP_CHAN_CONN_LESS: 145 if (__le16_to_cpu(la.l2_psm) == L2CAP_PSM_3DSP) 146 chan->sec_level = BT_SECURITY_SDP; 147 break; 148 case L2CAP_CHAN_CONN_ORIENTED: 149 if (__le16_to_cpu(la.l2_psm) == L2CAP_PSM_SDP || 150 __le16_to_cpu(la.l2_psm) == L2CAP_PSM_RFCOMM) 151 chan->sec_level = BT_SECURITY_SDP; 152 break; 153 case L2CAP_CHAN_RAW: 154 chan->sec_level = BT_SECURITY_SDP; 155 break; 156 case L2CAP_CHAN_FIXED: 157 /* Fixed channels default to the L2CAP core not holding a 158 * hci_conn reference for them. For fixed channels mapping to 159 * L2CAP sockets we do want to hold a reference so set the 160 * appropriate flag to request it. 161 */ 162 set_bit(FLAG_HOLD_HCI_CONN, &chan->flags); 163 break; 164 } 165 166 /* Use L2CAP_MODE_LE_FLOWCTL (CoC) in case of LE address and 167 * L2CAP_MODE_EXT_FLOWCTL (ECRED) has not been set. 168 */ 169 if (chan->psm && bdaddr_type_is_le(chan->src_type) && 170 chan->mode != L2CAP_MODE_EXT_FLOWCTL) 171 chan->mode = L2CAP_MODE_LE_FLOWCTL; 172 173 chan->state = BT_BOUND; 174 sk->sk_state = BT_BOUND; 175 176 done: 177 release_sock(sk); 178 return err; 179 } 180 181 static int l2cap_sock_connect(struct socket *sock, struct sockaddr *addr, 182 int alen, int flags) 183 { 184 struct sock *sk = sock->sk; 185 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 186 struct sockaddr_l2 la; 187 int len, err = 0; 188 bool zapped; 189 190 BT_DBG("sk %p", sk); 191 192 lock_sock(sk); 193 zapped = sock_flag(sk, SOCK_ZAPPED); 194 release_sock(sk); 195 196 if (zapped) 197 return -EINVAL; 198 199 if (!addr || alen < offsetofend(struct sockaddr, sa_family) || 200 addr->sa_family != AF_BLUETOOTH) 201 return -EINVAL; 202 203 memset(&la, 0, sizeof(la)); 204 len = min_t(unsigned int, sizeof(la), alen); 205 memcpy(&la, addr, len); 206 207 if (la.l2_cid && la.l2_psm) 208 return -EINVAL; 209 210 if (!bdaddr_type_is_valid(la.l2_bdaddr_type)) 211 return -EINVAL; 212 213 /* Check that the socket wasn't bound to something that 214 * conflicts with the address given to connect(). If chan->src 215 * is BDADDR_ANY it means bind() was never used, in which case 216 * chan->src_type and la.l2_bdaddr_type do not need to match. 217 */ 218 if (chan->src_type == BDADDR_BREDR && bacmp(&chan->src, BDADDR_ANY) && 219 bdaddr_type_is_le(la.l2_bdaddr_type)) { 220 /* Old user space versions will try to incorrectly bind 221 * the ATT socket using BDADDR_BREDR. We need to accept 222 * this and fix up the source address type only when 223 * both the source CID and destination CID indicate 224 * ATT. Anything else is an invalid combination. 225 */ 226 if (chan->scid != L2CAP_CID_ATT || 227 la.l2_cid != cpu_to_le16(L2CAP_CID_ATT)) 228 return -EINVAL; 229 230 /* We don't have the hdev available here to make a 231 * better decision on random vs public, but since all 232 * user space versions that exhibit this issue anyway do 233 * not support random local addresses assuming public 234 * here is good enough. 235 */ 236 chan->src_type = BDADDR_LE_PUBLIC; 237 } 238 239 if (chan->src_type != BDADDR_BREDR && la.l2_bdaddr_type == BDADDR_BREDR) 240 return -EINVAL; 241 242 if (bdaddr_type_is_le(la.l2_bdaddr_type)) { 243 /* We only allow ATT user space socket */ 244 if (la.l2_cid && 245 la.l2_cid != cpu_to_le16(L2CAP_CID_ATT)) 246 return -EINVAL; 247 } 248 249 /* Use L2CAP_MODE_LE_FLOWCTL (CoC) in case of LE address and 250 * L2CAP_MODE_EXT_FLOWCTL (ECRED) has not been set. 251 */ 252 if (chan->psm && bdaddr_type_is_le(chan->src_type) && 253 chan->mode != L2CAP_MODE_EXT_FLOWCTL) 254 chan->mode = L2CAP_MODE_LE_FLOWCTL; 255 256 err = l2cap_chan_connect(chan, la.l2_psm, __le16_to_cpu(la.l2_cid), 257 &la.l2_bdaddr, la.l2_bdaddr_type, 258 sk->sk_sndtimeo); 259 if (err) 260 return err; 261 262 lock_sock(sk); 263 264 err = bt_sock_wait_state(sk, BT_CONNECTED, 265 sock_sndtimeo(sk, flags & O_NONBLOCK)); 266 267 release_sock(sk); 268 269 return err; 270 } 271 272 static int l2cap_sock_listen(struct socket *sock, int backlog) 273 { 274 struct sock *sk = sock->sk; 275 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 276 int err = 0; 277 278 BT_DBG("sk %p backlog %d", sk, backlog); 279 280 lock_sock(sk); 281 282 if (sk->sk_state != BT_BOUND) { 283 err = -EBADFD; 284 goto done; 285 } 286 287 if (sk->sk_type != SOCK_SEQPACKET && sk->sk_type != SOCK_STREAM) { 288 err = -EINVAL; 289 goto done; 290 } 291 292 switch (chan->mode) { 293 case L2CAP_MODE_BASIC: 294 case L2CAP_MODE_LE_FLOWCTL: 295 break; 296 case L2CAP_MODE_EXT_FLOWCTL: 297 if (!enable_ecred) { 298 err = -EOPNOTSUPP; 299 goto done; 300 } 301 break; 302 case L2CAP_MODE_ERTM: 303 case L2CAP_MODE_STREAMING: 304 if (!disable_ertm) 305 break; 306 fallthrough; 307 default: 308 err = -EOPNOTSUPP; 309 goto done; 310 } 311 312 sk->sk_max_ack_backlog = backlog; 313 sk->sk_ack_backlog = 0; 314 315 /* Listening channels need to use nested locking in order not to 316 * cause lockdep warnings when the created child channels end up 317 * being locked in the same thread as the parent channel. 318 */ 319 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT); 320 321 chan->state = BT_LISTEN; 322 sk->sk_state = BT_LISTEN; 323 324 done: 325 release_sock(sk); 326 return err; 327 } 328 329 static int l2cap_sock_accept(struct socket *sock, struct socket *newsock, 330 struct proto_accept_arg *arg) 331 { 332 DEFINE_WAIT_FUNC(wait, woken_wake_function); 333 struct sock *sk = sock->sk, *nsk; 334 long timeo; 335 int err = 0; 336 337 lock_sock_nested(sk, L2CAP_NESTING_PARENT); 338 339 timeo = sock_rcvtimeo(sk, arg->flags & O_NONBLOCK); 340 341 BT_DBG("sk %p timeo %ld", sk, timeo); 342 343 /* Wait for an incoming connection. (wake-one). */ 344 add_wait_queue_exclusive(sk_sleep(sk), &wait); 345 while (1) { 346 if (sk->sk_state != BT_LISTEN) { 347 err = -EBADFD; 348 break; 349 } 350 351 nsk = bt_accept_dequeue(sk, newsock); 352 if (nsk) 353 break; 354 355 if (!timeo) { 356 err = -EAGAIN; 357 break; 358 } 359 360 if (signal_pending(current)) { 361 err = sock_intr_errno(timeo); 362 break; 363 } 364 365 release_sock(sk); 366 367 timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo); 368 369 lock_sock_nested(sk, L2CAP_NESTING_PARENT); 370 } 371 remove_wait_queue(sk_sleep(sk), &wait); 372 373 if (err) 374 goto done; 375 376 newsock->state = SS_CONNECTED; 377 378 BT_DBG("new socket %p", nsk); 379 380 done: 381 release_sock(sk); 382 return err; 383 } 384 385 static int l2cap_sock_getname(struct socket *sock, struct sockaddr *addr, 386 int peer) 387 { 388 struct sockaddr_l2 *la = (struct sockaddr_l2 *) addr; 389 struct sock *sk = sock->sk; 390 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 391 392 BT_DBG("sock %p, sk %p", sock, sk); 393 394 if (peer && sk->sk_state != BT_CONNECTED && 395 sk->sk_state != BT_CONNECT && sk->sk_state != BT_CONNECT2 && 396 sk->sk_state != BT_CONFIG) 397 return -ENOTCONN; 398 399 memset(la, 0, sizeof(struct sockaddr_l2)); 400 addr->sa_family = AF_BLUETOOTH; 401 402 la->l2_psm = chan->psm; 403 404 if (peer) { 405 bacpy(&la->l2_bdaddr, &chan->dst); 406 la->l2_cid = cpu_to_le16(chan->dcid); 407 la->l2_bdaddr_type = chan->dst_type; 408 } else { 409 bacpy(&la->l2_bdaddr, &chan->src); 410 la->l2_cid = cpu_to_le16(chan->scid); 411 la->l2_bdaddr_type = chan->src_type; 412 } 413 414 return sizeof(struct sockaddr_l2); 415 } 416 417 static int l2cap_get_mode(struct l2cap_chan *chan) 418 { 419 switch (chan->mode) { 420 case L2CAP_MODE_BASIC: 421 return BT_MODE_BASIC; 422 case L2CAP_MODE_ERTM: 423 return BT_MODE_ERTM; 424 case L2CAP_MODE_STREAMING: 425 return BT_MODE_STREAMING; 426 case L2CAP_MODE_LE_FLOWCTL: 427 return BT_MODE_LE_FLOWCTL; 428 case L2CAP_MODE_EXT_FLOWCTL: 429 return BT_MODE_EXT_FLOWCTL; 430 } 431 432 return -EINVAL; 433 } 434 435 static int l2cap_sock_getsockopt_old(struct socket *sock, int optname, 436 char __user *optval, int __user *optlen) 437 { 438 struct sock *sk = sock->sk; 439 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 440 struct l2cap_options opts; 441 struct l2cap_conninfo cinfo; 442 int err = 0; 443 size_t len; 444 u32 opt; 445 446 BT_DBG("sk %p", sk); 447 448 if (get_user(len, optlen)) 449 return -EFAULT; 450 451 lock_sock(sk); 452 453 switch (optname) { 454 case L2CAP_OPTIONS: 455 /* LE sockets should use BT_SNDMTU/BT_RCVMTU, but since 456 * legacy ATT code depends on getsockopt for 457 * L2CAP_OPTIONS we need to let this pass. 458 */ 459 if (bdaddr_type_is_le(chan->src_type) && 460 chan->scid != L2CAP_CID_ATT) { 461 err = -EINVAL; 462 break; 463 } 464 465 /* Only BR/EDR modes are supported here */ 466 switch (chan->mode) { 467 case L2CAP_MODE_BASIC: 468 case L2CAP_MODE_ERTM: 469 case L2CAP_MODE_STREAMING: 470 break; 471 default: 472 err = -EINVAL; 473 break; 474 } 475 476 if (err < 0) 477 break; 478 479 memset(&opts, 0, sizeof(opts)); 480 opts.imtu = chan->imtu; 481 opts.omtu = chan->omtu; 482 opts.flush_to = chan->flush_to; 483 opts.mode = chan->mode; 484 opts.fcs = chan->fcs; 485 opts.max_tx = chan->max_tx; 486 opts.txwin_size = chan->tx_win; 487 488 BT_DBG("mode 0x%2.2x", chan->mode); 489 490 len = min(len, sizeof(opts)); 491 if (copy_to_user(optval, (char *) &opts, len)) 492 err = -EFAULT; 493 494 break; 495 496 case L2CAP_LM: 497 switch (chan->sec_level) { 498 case BT_SECURITY_LOW: 499 opt = L2CAP_LM_AUTH; 500 break; 501 case BT_SECURITY_MEDIUM: 502 opt = L2CAP_LM_AUTH | L2CAP_LM_ENCRYPT; 503 break; 504 case BT_SECURITY_HIGH: 505 opt = L2CAP_LM_AUTH | L2CAP_LM_ENCRYPT | 506 L2CAP_LM_SECURE; 507 break; 508 case BT_SECURITY_FIPS: 509 opt = L2CAP_LM_AUTH | L2CAP_LM_ENCRYPT | 510 L2CAP_LM_SECURE | L2CAP_LM_FIPS; 511 break; 512 default: 513 opt = 0; 514 break; 515 } 516 517 if (test_bit(FLAG_ROLE_SWITCH, &chan->flags)) 518 opt |= L2CAP_LM_MASTER; 519 520 if (test_bit(FLAG_FORCE_RELIABLE, &chan->flags)) 521 opt |= L2CAP_LM_RELIABLE; 522 523 if (put_user(opt, (u32 __user *) optval)) 524 err = -EFAULT; 525 526 break; 527 528 case L2CAP_CONNINFO: 529 if (sk->sk_state != BT_CONNECTED && 530 !(sk->sk_state == BT_CONNECT2 && 531 test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags))) { 532 err = -ENOTCONN; 533 break; 534 } 535 536 memset(&cinfo, 0, sizeof(cinfo)); 537 cinfo.hci_handle = chan->conn->hcon->handle; 538 memcpy(cinfo.dev_class, chan->conn->hcon->dev_class, 3); 539 540 len = min(len, sizeof(cinfo)); 541 if (copy_to_user(optval, (char *) &cinfo, len)) 542 err = -EFAULT; 543 544 break; 545 546 default: 547 err = -ENOPROTOOPT; 548 break; 549 } 550 551 release_sock(sk); 552 return err; 553 } 554 555 static int l2cap_sock_getsockopt(struct socket *sock, int level, int optname, 556 char __user *optval, int __user *optlen) 557 { 558 struct sock *sk = sock->sk; 559 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 560 struct bt_security sec; 561 struct bt_power pwr; 562 u32 phys; 563 int len, mode, err = 0; 564 565 BT_DBG("sk %p", sk); 566 567 if (level == SOL_L2CAP) 568 return l2cap_sock_getsockopt_old(sock, optname, optval, optlen); 569 570 if (level != SOL_BLUETOOTH) 571 return -ENOPROTOOPT; 572 573 if (get_user(len, optlen)) 574 return -EFAULT; 575 576 lock_sock(sk); 577 578 switch (optname) { 579 case BT_SECURITY: 580 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED && 581 chan->chan_type != L2CAP_CHAN_FIXED && 582 chan->chan_type != L2CAP_CHAN_RAW) { 583 err = -EINVAL; 584 break; 585 } 586 587 memset(&sec, 0, sizeof(sec)); 588 if (chan->conn) { 589 sec.level = chan->conn->hcon->sec_level; 590 591 if (sk->sk_state == BT_CONNECTED) 592 sec.key_size = chan->conn->hcon->enc_key_size; 593 } else { 594 sec.level = chan->sec_level; 595 } 596 597 len = min_t(unsigned int, len, sizeof(sec)); 598 if (copy_to_user(optval, (char *) &sec, len)) 599 err = -EFAULT; 600 601 break; 602 603 case BT_DEFER_SETUP: 604 if (sk->sk_state != BT_BOUND && sk->sk_state != BT_LISTEN) { 605 err = -EINVAL; 606 break; 607 } 608 609 if (put_user(test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags), 610 (u32 __user *) optval)) 611 err = -EFAULT; 612 613 break; 614 615 case BT_FLUSHABLE: 616 if (put_user(test_bit(FLAG_FLUSHABLE, &chan->flags), 617 (u32 __user *) optval)) 618 err = -EFAULT; 619 620 break; 621 622 case BT_POWER: 623 if (sk->sk_type != SOCK_SEQPACKET && sk->sk_type != SOCK_STREAM 624 && sk->sk_type != SOCK_RAW) { 625 err = -EINVAL; 626 break; 627 } 628 629 pwr.force_active = test_bit(FLAG_FORCE_ACTIVE, &chan->flags); 630 631 len = min_t(unsigned int, len, sizeof(pwr)); 632 if (copy_to_user(optval, (char *) &pwr, len)) 633 err = -EFAULT; 634 635 break; 636 637 case BT_CHANNEL_POLICY: 638 if (put_user(chan->chan_policy, (u32 __user *) optval)) 639 err = -EFAULT; 640 break; 641 642 case BT_SNDMTU: 643 if (!bdaddr_type_is_le(chan->src_type)) { 644 err = -EINVAL; 645 break; 646 } 647 648 if (sk->sk_state != BT_CONNECTED) { 649 err = -ENOTCONN; 650 break; 651 } 652 653 if (put_user(chan->omtu, (u16 __user *) optval)) 654 err = -EFAULT; 655 break; 656 657 case BT_RCVMTU: 658 if (!bdaddr_type_is_le(chan->src_type)) { 659 err = -EINVAL; 660 break; 661 } 662 663 if (put_user(chan->imtu, (u16 __user *) optval)) 664 err = -EFAULT; 665 break; 666 667 case BT_PHY: 668 if (sk->sk_state != BT_CONNECTED) { 669 err = -ENOTCONN; 670 break; 671 } 672 673 phys = hci_conn_get_phy(chan->conn->hcon); 674 675 if (put_user(phys, (u32 __user *) optval)) 676 err = -EFAULT; 677 break; 678 679 case BT_MODE: 680 if (!enable_ecred) { 681 err = -ENOPROTOOPT; 682 break; 683 } 684 685 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) { 686 err = -EINVAL; 687 break; 688 } 689 690 mode = l2cap_get_mode(chan); 691 if (mode < 0) { 692 err = mode; 693 break; 694 } 695 696 if (put_user(mode, (u8 __user *) optval)) 697 err = -EFAULT; 698 break; 699 700 default: 701 err = -ENOPROTOOPT; 702 break; 703 } 704 705 release_sock(sk); 706 return err; 707 } 708 709 static bool l2cap_valid_mtu(struct l2cap_chan *chan, u16 mtu) 710 { 711 switch (chan->scid) { 712 case L2CAP_CID_ATT: 713 if (mtu && mtu < L2CAP_LE_MIN_MTU) 714 return false; 715 break; 716 717 default: 718 if (mtu && mtu < L2CAP_DEFAULT_MIN_MTU) 719 return false; 720 } 721 722 return true; 723 } 724 725 static int l2cap_sock_setsockopt_old(struct socket *sock, int optname, 726 sockptr_t optval, unsigned int optlen) 727 { 728 struct sock *sk = sock->sk; 729 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 730 struct l2cap_options opts; 731 int err = 0; 732 u32 opt; 733 734 BT_DBG("sk %p", sk); 735 736 lock_sock(sk); 737 738 switch (optname) { 739 case L2CAP_OPTIONS: 740 if (bdaddr_type_is_le(chan->src_type)) { 741 err = -EINVAL; 742 break; 743 } 744 745 if (sk->sk_state == BT_CONNECTED) { 746 err = -EINVAL; 747 break; 748 } 749 750 opts.imtu = chan->imtu; 751 opts.omtu = chan->omtu; 752 opts.flush_to = chan->flush_to; 753 opts.mode = chan->mode; 754 opts.fcs = chan->fcs; 755 opts.max_tx = chan->max_tx; 756 opts.txwin_size = chan->tx_win; 757 758 err = copy_safe_from_sockptr(&opts, sizeof(opts), optval, 759 optlen); 760 if (err) 761 break; 762 763 if (opts.txwin_size > L2CAP_DEFAULT_EXT_WINDOW) { 764 err = -EINVAL; 765 break; 766 } 767 768 if (!l2cap_valid_mtu(chan, opts.imtu)) { 769 err = -EINVAL; 770 break; 771 } 772 773 /* Only BR/EDR modes are supported here */ 774 switch (opts.mode) { 775 case L2CAP_MODE_BASIC: 776 clear_bit(CONF_STATE2_DEVICE, &chan->conf_state); 777 break; 778 case L2CAP_MODE_ERTM: 779 case L2CAP_MODE_STREAMING: 780 if (!disable_ertm) 781 break; 782 fallthrough; 783 default: 784 err = -EINVAL; 785 break; 786 } 787 788 if (err < 0) 789 break; 790 791 chan->mode = opts.mode; 792 793 BT_DBG("mode 0x%2.2x", chan->mode); 794 795 chan->imtu = opts.imtu; 796 chan->omtu = opts.omtu; 797 chan->fcs = opts.fcs; 798 chan->max_tx = opts.max_tx; 799 chan->tx_win = opts.txwin_size; 800 chan->flush_to = opts.flush_to; 801 break; 802 803 case L2CAP_LM: 804 err = copy_safe_from_sockptr(&opt, sizeof(opt), optval, optlen); 805 if (err) 806 break; 807 808 if (opt & L2CAP_LM_FIPS) { 809 err = -EINVAL; 810 break; 811 } 812 813 if (opt & L2CAP_LM_AUTH) 814 chan->sec_level = BT_SECURITY_LOW; 815 if (opt & L2CAP_LM_ENCRYPT) 816 chan->sec_level = BT_SECURITY_MEDIUM; 817 if (opt & L2CAP_LM_SECURE) 818 chan->sec_level = BT_SECURITY_HIGH; 819 820 if (opt & L2CAP_LM_MASTER) 821 set_bit(FLAG_ROLE_SWITCH, &chan->flags); 822 else 823 clear_bit(FLAG_ROLE_SWITCH, &chan->flags); 824 825 if (opt & L2CAP_LM_RELIABLE) 826 set_bit(FLAG_FORCE_RELIABLE, &chan->flags); 827 else 828 clear_bit(FLAG_FORCE_RELIABLE, &chan->flags); 829 break; 830 831 default: 832 err = -ENOPROTOOPT; 833 break; 834 } 835 836 release_sock(sk); 837 return err; 838 } 839 840 static int l2cap_set_mode(struct l2cap_chan *chan, u8 mode) 841 { 842 switch (mode) { 843 case BT_MODE_BASIC: 844 if (bdaddr_type_is_le(chan->src_type)) 845 return -EINVAL; 846 mode = L2CAP_MODE_BASIC; 847 clear_bit(CONF_STATE2_DEVICE, &chan->conf_state); 848 break; 849 case BT_MODE_ERTM: 850 if (!disable_ertm || bdaddr_type_is_le(chan->src_type)) 851 return -EINVAL; 852 mode = L2CAP_MODE_ERTM; 853 break; 854 case BT_MODE_STREAMING: 855 if (!disable_ertm || bdaddr_type_is_le(chan->src_type)) 856 return -EINVAL; 857 mode = L2CAP_MODE_STREAMING; 858 break; 859 case BT_MODE_LE_FLOWCTL: 860 if (!bdaddr_type_is_le(chan->src_type)) 861 return -EINVAL; 862 mode = L2CAP_MODE_LE_FLOWCTL; 863 break; 864 case BT_MODE_EXT_FLOWCTL: 865 /* TODO: Add support for ECRED PDUs to BR/EDR */ 866 if (!bdaddr_type_is_le(chan->src_type)) 867 return -EINVAL; 868 mode = L2CAP_MODE_EXT_FLOWCTL; 869 break; 870 default: 871 return -EINVAL; 872 } 873 874 chan->mode = mode; 875 876 return 0; 877 } 878 879 static int l2cap_sock_setsockopt(struct socket *sock, int level, int optname, 880 sockptr_t optval, unsigned int optlen) 881 { 882 struct sock *sk = sock->sk; 883 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 884 struct bt_security sec; 885 struct bt_power pwr; 886 struct l2cap_conn *conn; 887 int err = 0; 888 u32 opt; 889 u16 mtu; 890 u8 mode; 891 892 BT_DBG("sk %p", sk); 893 894 if (level == SOL_L2CAP) 895 return l2cap_sock_setsockopt_old(sock, optname, optval, optlen); 896 897 if (level != SOL_BLUETOOTH) 898 return -ENOPROTOOPT; 899 900 lock_sock(sk); 901 902 switch (optname) { 903 case BT_SECURITY: 904 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED && 905 chan->chan_type != L2CAP_CHAN_FIXED && 906 chan->chan_type != L2CAP_CHAN_RAW) { 907 err = -EINVAL; 908 break; 909 } 910 911 sec.level = BT_SECURITY_LOW; 912 913 err = copy_safe_from_sockptr(&sec, sizeof(sec), optval, optlen); 914 if (err) 915 break; 916 917 if (sec.level < BT_SECURITY_LOW || 918 sec.level > BT_SECURITY_FIPS) { 919 err = -EINVAL; 920 break; 921 } 922 923 chan->sec_level = sec.level; 924 925 if (!chan->conn) 926 break; 927 928 conn = chan->conn; 929 930 /* change security for LE channels */ 931 if (chan->scid == L2CAP_CID_ATT) { 932 if (smp_conn_security(conn->hcon, sec.level)) { 933 err = -EINVAL; 934 break; 935 } 936 937 set_bit(FLAG_PENDING_SECURITY, &chan->flags); 938 sk->sk_state = BT_CONFIG; 939 chan->state = BT_CONFIG; 940 941 /* or for ACL link */ 942 } else if ((sk->sk_state == BT_CONNECT2 && 943 test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags)) || 944 sk->sk_state == BT_CONNECTED) { 945 if (!l2cap_chan_check_security(chan, true)) 946 set_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags); 947 else 948 sk->sk_state_change(sk); 949 } else { 950 err = -EINVAL; 951 } 952 break; 953 954 case BT_DEFER_SETUP: 955 if (sk->sk_state != BT_BOUND && sk->sk_state != BT_LISTEN) { 956 err = -EINVAL; 957 break; 958 } 959 960 err = copy_safe_from_sockptr(&opt, sizeof(opt), optval, optlen); 961 if (err) 962 break; 963 964 if (opt) { 965 set_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags); 966 set_bit(FLAG_DEFER_SETUP, &chan->flags); 967 } else { 968 clear_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags); 969 clear_bit(FLAG_DEFER_SETUP, &chan->flags); 970 } 971 break; 972 973 case BT_FLUSHABLE: 974 err = copy_safe_from_sockptr(&opt, sizeof(opt), optval, optlen); 975 if (err) 976 break; 977 978 if (opt > BT_FLUSHABLE_ON) { 979 err = -EINVAL; 980 break; 981 } 982 983 if (opt == BT_FLUSHABLE_OFF) { 984 conn = chan->conn; 985 /* proceed further only when we have l2cap_conn and 986 No Flush support in the LM */ 987 if (!conn || !lmp_no_flush_capable(conn->hcon->hdev)) { 988 err = -EINVAL; 989 break; 990 } 991 } 992 993 if (opt) 994 set_bit(FLAG_FLUSHABLE, &chan->flags); 995 else 996 clear_bit(FLAG_FLUSHABLE, &chan->flags); 997 break; 998 999 case BT_POWER: 1000 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED && 1001 chan->chan_type != L2CAP_CHAN_RAW) { 1002 err = -EINVAL; 1003 break; 1004 } 1005 1006 pwr.force_active = BT_POWER_FORCE_ACTIVE_ON; 1007 1008 err = copy_safe_from_sockptr(&pwr, sizeof(pwr), optval, optlen); 1009 if (err) 1010 break; 1011 1012 if (pwr.force_active) 1013 set_bit(FLAG_FORCE_ACTIVE, &chan->flags); 1014 else 1015 clear_bit(FLAG_FORCE_ACTIVE, &chan->flags); 1016 break; 1017 1018 case BT_CHANNEL_POLICY: 1019 err = copy_safe_from_sockptr(&opt, sizeof(opt), optval, optlen); 1020 if (err) 1021 break; 1022 1023 err = -EOPNOTSUPP; 1024 break; 1025 1026 case BT_SNDMTU: 1027 if (!bdaddr_type_is_le(chan->src_type)) { 1028 err = -EINVAL; 1029 break; 1030 } 1031 1032 /* Setting is not supported as it's the remote side that 1033 * decides this. 1034 */ 1035 err = -EPERM; 1036 break; 1037 1038 case BT_RCVMTU: 1039 if (!bdaddr_type_is_le(chan->src_type)) { 1040 err = -EINVAL; 1041 break; 1042 } 1043 1044 if (chan->mode == L2CAP_MODE_LE_FLOWCTL && 1045 sk->sk_state == BT_CONNECTED) { 1046 err = -EISCONN; 1047 break; 1048 } 1049 1050 err = copy_safe_from_sockptr(&mtu, sizeof(mtu), optval, optlen); 1051 if (err) 1052 break; 1053 1054 if (chan->mode == L2CAP_MODE_EXT_FLOWCTL && 1055 sk->sk_state == BT_CONNECTED) 1056 err = l2cap_chan_reconfigure(chan, mtu); 1057 else 1058 chan->imtu = mtu; 1059 1060 break; 1061 1062 case BT_MODE: 1063 if (!enable_ecred) { 1064 err = -ENOPROTOOPT; 1065 break; 1066 } 1067 1068 BT_DBG("sk->sk_state %u", sk->sk_state); 1069 1070 if (sk->sk_state != BT_BOUND) { 1071 err = -EINVAL; 1072 break; 1073 } 1074 1075 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) { 1076 err = -EINVAL; 1077 break; 1078 } 1079 1080 err = copy_safe_from_sockptr(&mode, sizeof(mode), optval, 1081 optlen); 1082 if (err) 1083 break; 1084 1085 BT_DBG("mode %u", mode); 1086 1087 err = l2cap_set_mode(chan, mode); 1088 if (err) 1089 break; 1090 1091 BT_DBG("mode 0x%2.2x", chan->mode); 1092 1093 break; 1094 1095 default: 1096 err = -ENOPROTOOPT; 1097 break; 1098 } 1099 1100 release_sock(sk); 1101 return err; 1102 } 1103 1104 static int l2cap_sock_sendmsg(struct socket *sock, struct msghdr *msg, 1105 size_t len) 1106 { 1107 struct sock *sk = sock->sk; 1108 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 1109 int err; 1110 1111 BT_DBG("sock %p, sk %p", sock, sk); 1112 1113 err = sock_error(sk); 1114 if (err) 1115 return err; 1116 1117 if (msg->msg_flags & MSG_OOB) 1118 return -EOPNOTSUPP; 1119 1120 if (sk->sk_state != BT_CONNECTED) 1121 return -ENOTCONN; 1122 1123 lock_sock(sk); 1124 err = bt_sock_wait_ready(sk, msg->msg_flags); 1125 release_sock(sk); 1126 if (err) 1127 return err; 1128 1129 l2cap_chan_lock(chan); 1130 err = l2cap_chan_send(chan, msg, len); 1131 l2cap_chan_unlock(chan); 1132 1133 return err; 1134 } 1135 1136 static void l2cap_publish_rx_avail(struct l2cap_chan *chan) 1137 { 1138 struct sock *sk = chan->data; 1139 ssize_t avail = sk->sk_rcvbuf - atomic_read(&sk->sk_rmem_alloc); 1140 int expected_skbs, skb_overhead; 1141 1142 if (avail <= 0) { 1143 l2cap_chan_rx_avail(chan, 0); 1144 return; 1145 } 1146 1147 if (!chan->mps) { 1148 l2cap_chan_rx_avail(chan, -1); 1149 return; 1150 } 1151 1152 /* Correct available memory by estimated sk_buff overhead. 1153 * This is significant due to small transfer sizes. However, accept 1154 * at least one full packet if receive space is non-zero. 1155 */ 1156 expected_skbs = DIV_ROUND_UP(avail, chan->mps); 1157 skb_overhead = expected_skbs * sizeof(struct sk_buff); 1158 if (skb_overhead < avail) 1159 l2cap_chan_rx_avail(chan, avail - skb_overhead); 1160 else 1161 l2cap_chan_rx_avail(chan, -1); 1162 } 1163 1164 static int l2cap_sock_recvmsg(struct socket *sock, struct msghdr *msg, 1165 size_t len, int flags) 1166 { 1167 struct sock *sk = sock->sk; 1168 struct l2cap_pinfo *pi = l2cap_pi(sk); 1169 int err; 1170 1171 lock_sock(sk); 1172 1173 if (sk->sk_state == BT_CONNECT2 && test_bit(BT_SK_DEFER_SETUP, 1174 &bt_sk(sk)->flags)) { 1175 if (pi->chan->mode == L2CAP_MODE_EXT_FLOWCTL) { 1176 sk->sk_state = BT_CONNECTED; 1177 pi->chan->state = BT_CONNECTED; 1178 __l2cap_ecred_conn_rsp_defer(pi->chan); 1179 } else if (bdaddr_type_is_le(pi->chan->src_type)) { 1180 sk->sk_state = BT_CONNECTED; 1181 pi->chan->state = BT_CONNECTED; 1182 __l2cap_le_connect_rsp_defer(pi->chan); 1183 } else { 1184 sk->sk_state = BT_CONFIG; 1185 pi->chan->state = BT_CONFIG; 1186 __l2cap_connect_rsp_defer(pi->chan); 1187 } 1188 1189 err = 0; 1190 goto done; 1191 } 1192 1193 release_sock(sk); 1194 1195 if (sock->type == SOCK_STREAM) 1196 err = bt_sock_stream_recvmsg(sock, msg, len, flags); 1197 else 1198 err = bt_sock_recvmsg(sock, msg, len, flags); 1199 1200 if (pi->chan->mode != L2CAP_MODE_ERTM && 1201 pi->chan->mode != L2CAP_MODE_LE_FLOWCTL && 1202 pi->chan->mode != L2CAP_MODE_EXT_FLOWCTL) 1203 return err; 1204 1205 lock_sock(sk); 1206 1207 l2cap_publish_rx_avail(pi->chan); 1208 1209 /* Attempt to put pending rx data in the socket buffer */ 1210 while (!list_empty(&pi->rx_busy)) { 1211 struct l2cap_rx_busy *rx_busy = 1212 list_first_entry(&pi->rx_busy, 1213 struct l2cap_rx_busy, 1214 list); 1215 if (__sock_queue_rcv_skb(sk, rx_busy->skb) < 0) 1216 goto done; 1217 list_del(&rx_busy->list); 1218 kfree(rx_busy); 1219 } 1220 1221 /* Restore data flow when half of the receive buffer is 1222 * available. This avoids resending large numbers of 1223 * frames. 1224 */ 1225 if (test_bit(CONN_LOCAL_BUSY, &pi->chan->conn_state) && 1226 atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf >> 1) 1227 l2cap_chan_busy(pi->chan, 0); 1228 1229 done: 1230 release_sock(sk); 1231 return err; 1232 } 1233 1234 /* Kill socket (only if zapped and orphan) 1235 * Must be called on unlocked socket, with l2cap channel lock. 1236 */ 1237 static void l2cap_sock_kill(struct sock *sk) 1238 { 1239 if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket) 1240 return; 1241 1242 BT_DBG("sk %p state %s", sk, state_to_string(sk->sk_state)); 1243 1244 /* Sock is dead, so set chan data to NULL, avoid other task use invalid 1245 * sock pointer. 1246 */ 1247 l2cap_pi(sk)->chan->data = NULL; 1248 /* Kill poor orphan */ 1249 1250 l2cap_chan_put(l2cap_pi(sk)->chan); 1251 sock_set_flag(sk, SOCK_DEAD); 1252 sock_put(sk); 1253 } 1254 1255 static int __l2cap_wait_ack(struct sock *sk, struct l2cap_chan *chan) 1256 { 1257 DECLARE_WAITQUEUE(wait, current); 1258 int err = 0; 1259 int timeo = L2CAP_WAIT_ACK_POLL_PERIOD; 1260 /* Timeout to prevent infinite loop */ 1261 unsigned long timeout = jiffies + L2CAP_WAIT_ACK_TIMEOUT; 1262 1263 add_wait_queue(sk_sleep(sk), &wait); 1264 set_current_state(TASK_INTERRUPTIBLE); 1265 do { 1266 BT_DBG("Waiting for %d ACKs, timeout %04d ms", 1267 chan->unacked_frames, time_after(jiffies, timeout) ? 0 : 1268 jiffies_to_msecs(timeout - jiffies)); 1269 1270 if (!timeo) 1271 timeo = L2CAP_WAIT_ACK_POLL_PERIOD; 1272 1273 if (signal_pending(current)) { 1274 err = sock_intr_errno(timeo); 1275 break; 1276 } 1277 1278 release_sock(sk); 1279 timeo = schedule_timeout(timeo); 1280 lock_sock(sk); 1281 set_current_state(TASK_INTERRUPTIBLE); 1282 1283 err = sock_error(sk); 1284 if (err) 1285 break; 1286 1287 if (time_after(jiffies, timeout)) { 1288 err = -ENOLINK; 1289 break; 1290 } 1291 1292 } while (chan->unacked_frames > 0 && 1293 chan->state == BT_CONNECTED); 1294 1295 set_current_state(TASK_RUNNING); 1296 remove_wait_queue(sk_sleep(sk), &wait); 1297 return err; 1298 } 1299 1300 static int l2cap_sock_shutdown(struct socket *sock, int how) 1301 { 1302 struct sock *sk = sock->sk; 1303 struct l2cap_chan *chan; 1304 struct l2cap_conn *conn; 1305 int err = 0; 1306 1307 BT_DBG("sock %p, sk %p, how %d", sock, sk, how); 1308 1309 /* 'how' parameter is mapped to sk_shutdown as follows: 1310 * SHUT_RD (0) --> RCV_SHUTDOWN (1) 1311 * SHUT_WR (1) --> SEND_SHUTDOWN (2) 1312 * SHUT_RDWR (2) --> SHUTDOWN_MASK (3) 1313 */ 1314 how++; 1315 1316 if (!sk) 1317 return 0; 1318 1319 lock_sock(sk); 1320 1321 if ((sk->sk_shutdown & how) == how) 1322 goto shutdown_already; 1323 1324 BT_DBG("Handling sock shutdown"); 1325 1326 /* prevent sk structure from being freed whilst unlocked */ 1327 sock_hold(sk); 1328 1329 /* prevent chan structure from being freed whilst unlocked */ 1330 chan = l2cap_chan_hold_unless_zero(l2cap_pi(sk)->chan); 1331 if (!chan) 1332 goto shutdown_already; 1333 1334 BT_DBG("chan %p state %s", chan, state_to_string(chan->state)); 1335 1336 if (chan->mode == L2CAP_MODE_ERTM && 1337 chan->unacked_frames > 0 && 1338 chan->state == BT_CONNECTED) { 1339 err = __l2cap_wait_ack(sk, chan); 1340 1341 /* After waiting for ACKs, check whether shutdown 1342 * has already been actioned to close the L2CAP 1343 * link such as by l2cap_disconnection_req(). 1344 */ 1345 if ((sk->sk_shutdown & how) == how) 1346 goto shutdown_matched; 1347 } 1348 1349 /* Try setting the RCV_SHUTDOWN bit, return early if SEND_SHUTDOWN 1350 * is already set 1351 */ 1352 if ((how & RCV_SHUTDOWN) && !(sk->sk_shutdown & RCV_SHUTDOWN)) { 1353 sk->sk_shutdown |= RCV_SHUTDOWN; 1354 if ((sk->sk_shutdown & how) == how) 1355 goto shutdown_matched; 1356 } 1357 1358 sk->sk_shutdown |= SEND_SHUTDOWN; 1359 release_sock(sk); 1360 1361 l2cap_chan_lock(chan); 1362 /* prevent conn structure from being freed */ 1363 conn = l2cap_conn_hold_unless_zero(chan->conn); 1364 l2cap_chan_unlock(chan); 1365 1366 if (conn) 1367 /* mutex lock must be taken before l2cap_chan_lock() */ 1368 mutex_lock(&conn->lock); 1369 1370 l2cap_chan_lock(chan); 1371 l2cap_chan_close(chan, 0); 1372 l2cap_chan_unlock(chan); 1373 1374 if (conn) { 1375 mutex_unlock(&conn->lock); 1376 l2cap_conn_put(conn); 1377 } 1378 1379 lock_sock(sk); 1380 1381 if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime && 1382 !(current->flags & PF_EXITING)) 1383 err = bt_sock_wait_state(sk, BT_CLOSED, 1384 sk->sk_lingertime); 1385 1386 shutdown_matched: 1387 l2cap_chan_put(chan); 1388 sock_put(sk); 1389 1390 shutdown_already: 1391 if (!err && sk->sk_err) 1392 err = -sk->sk_err; 1393 1394 release_sock(sk); 1395 1396 BT_DBG("Sock shutdown complete err: %d", err); 1397 1398 return err; 1399 } 1400 1401 static int l2cap_sock_release(struct socket *sock) 1402 { 1403 struct sock *sk = sock->sk; 1404 int err; 1405 struct l2cap_chan *chan; 1406 1407 BT_DBG("sock %p, sk %p", sock, sk); 1408 1409 if (!sk) 1410 return 0; 1411 1412 l2cap_sock_cleanup_listen(sk); 1413 bt_sock_unlink(&l2cap_sk_list, sk); 1414 1415 err = l2cap_sock_shutdown(sock, SHUT_RDWR); 1416 chan = l2cap_pi(sk)->chan; 1417 1418 l2cap_chan_hold(chan); 1419 l2cap_chan_lock(chan); 1420 1421 sock_orphan(sk); 1422 l2cap_sock_kill(sk); 1423 1424 l2cap_chan_unlock(chan); 1425 l2cap_chan_put(chan); 1426 1427 return err; 1428 } 1429 1430 static void l2cap_sock_cleanup_listen(struct sock *parent) 1431 { 1432 struct sock *sk; 1433 1434 BT_DBG("parent %p state %s", parent, 1435 state_to_string(parent->sk_state)); 1436 1437 /* Close not yet accepted channels */ 1438 while ((sk = bt_accept_dequeue(parent, NULL))) { 1439 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 1440 1441 BT_DBG("child chan %p state %s", chan, 1442 state_to_string(chan->state)); 1443 1444 l2cap_chan_hold(chan); 1445 l2cap_chan_lock(chan); 1446 1447 __clear_chan_timer(chan); 1448 l2cap_chan_close(chan, ECONNRESET); 1449 l2cap_sock_kill(sk); 1450 1451 l2cap_chan_unlock(chan); 1452 l2cap_chan_put(chan); 1453 } 1454 } 1455 1456 static struct l2cap_chan *l2cap_sock_new_connection_cb(struct l2cap_chan *chan) 1457 { 1458 struct sock *sk, *parent = chan->data; 1459 1460 lock_sock(parent); 1461 1462 /* Check for backlog size */ 1463 if (sk_acceptq_is_full(parent)) { 1464 BT_DBG("backlog full %d", parent->sk_ack_backlog); 1465 release_sock(parent); 1466 return NULL; 1467 } 1468 1469 sk = l2cap_sock_alloc(sock_net(parent), NULL, BTPROTO_L2CAP, 1470 GFP_ATOMIC, 0); 1471 if (!sk) { 1472 release_sock(parent); 1473 return NULL; 1474 } 1475 1476 bt_sock_reclassify_lock(sk, BTPROTO_L2CAP); 1477 1478 l2cap_sock_init(sk, parent); 1479 1480 bt_accept_enqueue(parent, sk, false); 1481 1482 release_sock(parent); 1483 1484 return l2cap_pi(sk)->chan; 1485 } 1486 1487 static int l2cap_sock_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) 1488 { 1489 struct sock *sk; 1490 struct l2cap_pinfo *pi; 1491 int err; 1492 1493 sk = chan->data; 1494 if (!sk) 1495 return -ENXIO; 1496 1497 pi = l2cap_pi(sk); 1498 lock_sock(sk); 1499 if (chan->mode == L2CAP_MODE_ERTM && !list_empty(&pi->rx_busy)) { 1500 err = -ENOMEM; 1501 goto done; 1502 } 1503 1504 if (chan->mode != L2CAP_MODE_ERTM && 1505 chan->mode != L2CAP_MODE_STREAMING && 1506 chan->mode != L2CAP_MODE_LE_FLOWCTL && 1507 chan->mode != L2CAP_MODE_EXT_FLOWCTL) { 1508 /* Even if no filter is attached, we could potentially 1509 * get errors from security modules, etc. 1510 */ 1511 err = sk_filter(sk, skb); 1512 if (err) 1513 goto done; 1514 } 1515 1516 err = __sock_queue_rcv_skb(sk, skb); 1517 1518 l2cap_publish_rx_avail(chan); 1519 1520 /* For ERTM and LE, handle a skb that doesn't fit into the recv 1521 * buffer. This is important to do because the data frames 1522 * have already been acked, so the skb cannot be discarded. 1523 * 1524 * Notify the l2cap core that the buffer is full, so the 1525 * LOCAL_BUSY state is entered and no more frames are 1526 * acked and reassembled until there is buffer space 1527 * available. 1528 */ 1529 if (err < 0 && 1530 (chan->mode == L2CAP_MODE_ERTM || 1531 chan->mode == L2CAP_MODE_LE_FLOWCTL || 1532 chan->mode == L2CAP_MODE_EXT_FLOWCTL)) { 1533 struct l2cap_rx_busy *rx_busy = 1534 kmalloc(sizeof(*rx_busy), GFP_KERNEL); 1535 if (!rx_busy) { 1536 err = -ENOMEM; 1537 goto done; 1538 } 1539 rx_busy->skb = skb; 1540 list_add_tail(&rx_busy->list, &pi->rx_busy); 1541 l2cap_chan_busy(chan, 1); 1542 err = 0; 1543 } 1544 1545 done: 1546 release_sock(sk); 1547 1548 return err; 1549 } 1550 1551 static void l2cap_sock_close_cb(struct l2cap_chan *chan) 1552 { 1553 struct sock *sk = chan->data; 1554 1555 if (!sk) 1556 return; 1557 1558 l2cap_sock_kill(sk); 1559 } 1560 1561 static void l2cap_sock_teardown_cb(struct l2cap_chan *chan, int err) 1562 { 1563 struct sock *sk = chan->data; 1564 struct sock *parent; 1565 1566 if (!sk) 1567 return; 1568 1569 BT_DBG("chan %p state %s", chan, state_to_string(chan->state)); 1570 1571 /* This callback can be called both for server (BT_LISTEN) 1572 * sockets as well as "normal" ones. To avoid lockdep warnings 1573 * with child socket locking (through l2cap_sock_cleanup_listen) 1574 * we need separation into separate nesting levels. The simplest 1575 * way to accomplish this is to inherit the nesting level used 1576 * for the channel. 1577 */ 1578 lock_sock_nested(sk, atomic_read(&chan->nesting)); 1579 1580 parent = bt_sk(sk)->parent; 1581 1582 switch (chan->state) { 1583 case BT_OPEN: 1584 case BT_BOUND: 1585 case BT_CLOSED: 1586 break; 1587 case BT_LISTEN: 1588 l2cap_sock_cleanup_listen(sk); 1589 sk->sk_state = BT_CLOSED; 1590 chan->state = BT_CLOSED; 1591 1592 break; 1593 default: 1594 sk->sk_state = BT_CLOSED; 1595 chan->state = BT_CLOSED; 1596 1597 sk->sk_err = err; 1598 1599 if (parent) { 1600 bt_accept_unlink(sk); 1601 parent->sk_data_ready(parent); 1602 } else { 1603 sk->sk_state_change(sk); 1604 } 1605 1606 break; 1607 } 1608 release_sock(sk); 1609 1610 /* Only zap after cleanup to avoid use after free race */ 1611 sock_set_flag(sk, SOCK_ZAPPED); 1612 1613 } 1614 1615 static void l2cap_sock_state_change_cb(struct l2cap_chan *chan, int state, 1616 int err) 1617 { 1618 struct sock *sk = chan->data; 1619 1620 sk->sk_state = state; 1621 1622 if (err) 1623 sk->sk_err = err; 1624 } 1625 1626 static struct sk_buff *l2cap_sock_alloc_skb_cb(struct l2cap_chan *chan, 1627 unsigned long hdr_len, 1628 unsigned long len, int nb) 1629 { 1630 struct sock *sk = chan->data; 1631 struct sk_buff *skb; 1632 int err; 1633 1634 l2cap_chan_unlock(chan); 1635 skb = bt_skb_send_alloc(sk, hdr_len + len, nb, &err); 1636 l2cap_chan_lock(chan); 1637 1638 if (!skb) 1639 return ERR_PTR(err); 1640 1641 /* Channel lock is released before requesting new skb and then 1642 * reacquired thus we need to recheck channel state. 1643 */ 1644 if (chan->state != BT_CONNECTED) { 1645 kfree_skb(skb); 1646 return ERR_PTR(-ENOTCONN); 1647 } 1648 1649 skb->priority = READ_ONCE(sk->sk_priority); 1650 1651 bt_cb(skb)->l2cap.chan = chan; 1652 1653 return skb; 1654 } 1655 1656 static void l2cap_sock_ready_cb(struct l2cap_chan *chan) 1657 { 1658 struct sock *sk = chan->data; 1659 struct sock *parent; 1660 1661 lock_sock(sk); 1662 1663 parent = bt_sk(sk)->parent; 1664 1665 BT_DBG("sk %p, parent %p", sk, parent); 1666 1667 sk->sk_state = BT_CONNECTED; 1668 sk->sk_state_change(sk); 1669 1670 if (parent) 1671 parent->sk_data_ready(parent); 1672 1673 release_sock(sk); 1674 } 1675 1676 static void l2cap_sock_defer_cb(struct l2cap_chan *chan) 1677 { 1678 struct sock *parent, *sk = chan->data; 1679 1680 lock_sock(sk); 1681 1682 parent = bt_sk(sk)->parent; 1683 if (parent) 1684 parent->sk_data_ready(parent); 1685 1686 release_sock(sk); 1687 } 1688 1689 static void l2cap_sock_resume_cb(struct l2cap_chan *chan) 1690 { 1691 struct sock *sk = chan->data; 1692 1693 if (test_and_clear_bit(FLAG_PENDING_SECURITY, &chan->flags)) { 1694 sk->sk_state = BT_CONNECTED; 1695 chan->state = BT_CONNECTED; 1696 } 1697 1698 clear_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags); 1699 sk->sk_state_change(sk); 1700 } 1701 1702 static void l2cap_sock_set_shutdown_cb(struct l2cap_chan *chan) 1703 { 1704 struct sock *sk = chan->data; 1705 1706 lock_sock(sk); 1707 sk->sk_shutdown = SHUTDOWN_MASK; 1708 release_sock(sk); 1709 } 1710 1711 static long l2cap_sock_get_sndtimeo_cb(struct l2cap_chan *chan) 1712 { 1713 struct sock *sk = chan->data; 1714 1715 return sk->sk_sndtimeo; 1716 } 1717 1718 static struct pid *l2cap_sock_get_peer_pid_cb(struct l2cap_chan *chan) 1719 { 1720 struct sock *sk = chan->data; 1721 1722 return sk->sk_peer_pid; 1723 } 1724 1725 static void l2cap_sock_suspend_cb(struct l2cap_chan *chan) 1726 { 1727 struct sock *sk = chan->data; 1728 1729 set_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags); 1730 sk->sk_state_change(sk); 1731 } 1732 1733 static int l2cap_sock_filter(struct l2cap_chan *chan, struct sk_buff *skb) 1734 { 1735 struct sock *sk = chan->data; 1736 1737 switch (chan->mode) { 1738 case L2CAP_MODE_ERTM: 1739 case L2CAP_MODE_STREAMING: 1740 return sk_filter(sk, skb); 1741 } 1742 1743 return 0; 1744 } 1745 1746 static const struct l2cap_ops l2cap_chan_ops = { 1747 .name = "L2CAP Socket Interface", 1748 .new_connection = l2cap_sock_new_connection_cb, 1749 .recv = l2cap_sock_recv_cb, 1750 .close = l2cap_sock_close_cb, 1751 .teardown = l2cap_sock_teardown_cb, 1752 .state_change = l2cap_sock_state_change_cb, 1753 .ready = l2cap_sock_ready_cb, 1754 .defer = l2cap_sock_defer_cb, 1755 .resume = l2cap_sock_resume_cb, 1756 .suspend = l2cap_sock_suspend_cb, 1757 .set_shutdown = l2cap_sock_set_shutdown_cb, 1758 .get_sndtimeo = l2cap_sock_get_sndtimeo_cb, 1759 .get_peer_pid = l2cap_sock_get_peer_pid_cb, 1760 .alloc_skb = l2cap_sock_alloc_skb_cb, 1761 .filter = l2cap_sock_filter, 1762 }; 1763 1764 static void l2cap_sock_destruct(struct sock *sk) 1765 { 1766 struct l2cap_rx_busy *rx_busy, *next; 1767 1768 BT_DBG("sk %p", sk); 1769 1770 if (l2cap_pi(sk)->chan) { 1771 l2cap_pi(sk)->chan->data = NULL; 1772 l2cap_chan_put(l2cap_pi(sk)->chan); 1773 } 1774 1775 list_for_each_entry_safe(rx_busy, next, &l2cap_pi(sk)->rx_busy, list) { 1776 kfree_skb(rx_busy->skb); 1777 list_del(&rx_busy->list); 1778 kfree(rx_busy); 1779 } 1780 1781 skb_queue_purge(&sk->sk_receive_queue); 1782 skb_queue_purge(&sk->sk_write_queue); 1783 } 1784 1785 static void l2cap_skb_msg_name(struct sk_buff *skb, void *msg_name, 1786 int *msg_namelen) 1787 { 1788 DECLARE_SOCKADDR(struct sockaddr_l2 *, la, msg_name); 1789 1790 memset(la, 0, sizeof(struct sockaddr_l2)); 1791 la->l2_family = AF_BLUETOOTH; 1792 la->l2_psm = bt_cb(skb)->l2cap.psm; 1793 bacpy(&la->l2_bdaddr, &bt_cb(skb)->l2cap.bdaddr); 1794 1795 *msg_namelen = sizeof(struct sockaddr_l2); 1796 } 1797 1798 static void l2cap_sock_init(struct sock *sk, struct sock *parent) 1799 { 1800 struct l2cap_chan *chan = l2cap_pi(sk)->chan; 1801 1802 BT_DBG("sk %p", sk); 1803 1804 if (parent) { 1805 struct l2cap_chan *pchan = l2cap_pi(parent)->chan; 1806 1807 sk->sk_type = parent->sk_type; 1808 bt_sk(sk)->flags = bt_sk(parent)->flags; 1809 1810 chan->chan_type = pchan->chan_type; 1811 chan->imtu = pchan->imtu; 1812 chan->omtu = pchan->omtu; 1813 chan->conf_state = pchan->conf_state; 1814 chan->mode = pchan->mode; 1815 chan->fcs = pchan->fcs; 1816 chan->max_tx = pchan->max_tx; 1817 chan->tx_win = pchan->tx_win; 1818 chan->tx_win_max = pchan->tx_win_max; 1819 chan->sec_level = pchan->sec_level; 1820 chan->flags = pchan->flags; 1821 chan->tx_credits = pchan->tx_credits; 1822 chan->rx_credits = pchan->rx_credits; 1823 1824 if (chan->chan_type == L2CAP_CHAN_FIXED) { 1825 chan->scid = pchan->scid; 1826 chan->dcid = pchan->scid; 1827 } 1828 1829 security_sk_clone(parent, sk); 1830 } else { 1831 switch (sk->sk_type) { 1832 case SOCK_RAW: 1833 chan->chan_type = L2CAP_CHAN_RAW; 1834 break; 1835 case SOCK_DGRAM: 1836 chan->chan_type = L2CAP_CHAN_CONN_LESS; 1837 bt_sk(sk)->skb_msg_name = l2cap_skb_msg_name; 1838 break; 1839 case SOCK_SEQPACKET: 1840 case SOCK_STREAM: 1841 chan->chan_type = L2CAP_CHAN_CONN_ORIENTED; 1842 break; 1843 } 1844 1845 chan->imtu = L2CAP_DEFAULT_MTU; 1846 chan->omtu = 0; 1847 if (!disable_ertm && sk->sk_type == SOCK_STREAM) { 1848 chan->mode = L2CAP_MODE_ERTM; 1849 set_bit(CONF_STATE2_DEVICE, &chan->conf_state); 1850 } else { 1851 chan->mode = L2CAP_MODE_BASIC; 1852 } 1853 1854 l2cap_chan_set_defaults(chan); 1855 } 1856 1857 /* Default config options */ 1858 chan->flush_to = L2CAP_DEFAULT_FLUSH_TO; 1859 1860 chan->data = sk; 1861 chan->ops = &l2cap_chan_ops; 1862 1863 l2cap_publish_rx_avail(chan); 1864 } 1865 1866 static struct proto l2cap_proto = { 1867 .name = "L2CAP", 1868 .owner = THIS_MODULE, 1869 .obj_size = sizeof(struct l2cap_pinfo) 1870 }; 1871 1872 static struct sock *l2cap_sock_alloc(struct net *net, struct socket *sock, 1873 int proto, gfp_t prio, int kern) 1874 { 1875 struct sock *sk; 1876 struct l2cap_chan *chan; 1877 1878 sk = bt_sock_alloc(net, sock, &l2cap_proto, proto, prio, kern); 1879 if (!sk) 1880 return NULL; 1881 1882 sk->sk_destruct = l2cap_sock_destruct; 1883 sk->sk_sndtimeo = L2CAP_CONN_TIMEOUT; 1884 1885 INIT_LIST_HEAD(&l2cap_pi(sk)->rx_busy); 1886 1887 chan = l2cap_chan_create(); 1888 if (!chan) { 1889 sk_free(sk); 1890 if (sock) 1891 sock->sk = NULL; 1892 return NULL; 1893 } 1894 1895 l2cap_chan_hold(chan); 1896 1897 l2cap_pi(sk)->chan = chan; 1898 1899 return sk; 1900 } 1901 1902 static int l2cap_sock_create(struct net *net, struct socket *sock, int protocol, 1903 int kern) 1904 { 1905 struct sock *sk; 1906 1907 BT_DBG("sock %p", sock); 1908 1909 sock->state = SS_UNCONNECTED; 1910 1911 if (sock->type != SOCK_SEQPACKET && sock->type != SOCK_STREAM && 1912 sock->type != SOCK_DGRAM && sock->type != SOCK_RAW) 1913 return -ESOCKTNOSUPPORT; 1914 1915 if (sock->type == SOCK_RAW && !kern && !capable(CAP_NET_RAW)) 1916 return -EPERM; 1917 1918 sock->ops = &l2cap_sock_ops; 1919 1920 sk = l2cap_sock_alloc(net, sock, protocol, GFP_ATOMIC, kern); 1921 if (!sk) 1922 return -ENOMEM; 1923 1924 l2cap_sock_init(sk, NULL); 1925 bt_sock_link(&l2cap_sk_list, sk); 1926 return 0; 1927 } 1928 1929 static const struct proto_ops l2cap_sock_ops = { 1930 .family = PF_BLUETOOTH, 1931 .owner = THIS_MODULE, 1932 .release = l2cap_sock_release, 1933 .bind = l2cap_sock_bind, 1934 .connect = l2cap_sock_connect, 1935 .listen = l2cap_sock_listen, 1936 .accept = l2cap_sock_accept, 1937 .getname = l2cap_sock_getname, 1938 .sendmsg = l2cap_sock_sendmsg, 1939 .recvmsg = l2cap_sock_recvmsg, 1940 .poll = bt_sock_poll, 1941 .ioctl = bt_sock_ioctl, 1942 .gettstamp = sock_gettstamp, 1943 .mmap = sock_no_mmap, 1944 .socketpair = sock_no_socketpair, 1945 .shutdown = l2cap_sock_shutdown, 1946 .setsockopt = l2cap_sock_setsockopt, 1947 .getsockopt = l2cap_sock_getsockopt 1948 }; 1949 1950 static const struct net_proto_family l2cap_sock_family_ops = { 1951 .family = PF_BLUETOOTH, 1952 .owner = THIS_MODULE, 1953 .create = l2cap_sock_create, 1954 }; 1955 1956 int __init l2cap_init_sockets(void) 1957 { 1958 int err; 1959 1960 BUILD_BUG_ON(sizeof(struct sockaddr_l2) > sizeof(struct sockaddr)); 1961 1962 err = proto_register(&l2cap_proto, 0); 1963 if (err < 0) 1964 return err; 1965 1966 err = bt_sock_register(BTPROTO_L2CAP, &l2cap_sock_family_ops); 1967 if (err < 0) { 1968 BT_ERR("L2CAP socket registration failed"); 1969 goto error; 1970 } 1971 1972 err = bt_procfs_init(&init_net, "l2cap", &l2cap_sk_list, 1973 NULL); 1974 if (err < 0) { 1975 BT_ERR("Failed to create L2CAP proc file"); 1976 bt_sock_unregister(BTPROTO_L2CAP); 1977 goto error; 1978 } 1979 1980 BT_INFO("L2CAP socket layer initialized"); 1981 1982 return 0; 1983 1984 error: 1985 proto_unregister(&l2cap_proto); 1986 return err; 1987 } 1988 1989 void l2cap_cleanup_sockets(void) 1990 { 1991 bt_procfs_cleanup(&init_net, "l2cap"); 1992 bt_sock_unregister(BTPROTO_L2CAP); 1993 proto_unregister(&l2cap_proto); 1994 } 1995