1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2011 Intel Corporation. All rights reserved. 4 * Copyright (C) 2014 Marvell International Ltd. 5 */ 6 7 #define pr_fmt(fmt) "llcp: %s: " fmt, __func__ 8 9 #include <linux/init.h> 10 #include <linux/kernel.h> 11 #include <linux/list.h> 12 #include <linux/nfc.h> 13 14 #include "nfc.h" 15 #include "llcp.h" 16 17 static u8 llcp_magic[3] = {0x46, 0x66, 0x6d}; 18 19 static LIST_HEAD(llcp_devices); 20 /* Protects llcp_devices list */ 21 static DEFINE_SPINLOCK(llcp_devices_lock); 22 23 static void nfc_llcp_rx_skb(struct nfc_llcp_local *local, struct sk_buff *skb); 24 25 void nfc_llcp_sock_link(struct llcp_sock_list *l, struct sock *sk) 26 { 27 write_lock(&l->lock); 28 sk_add_node(sk, &l->head); 29 write_unlock(&l->lock); 30 } 31 32 void nfc_llcp_sock_unlink(struct llcp_sock_list *l, struct sock *sk) 33 { 34 write_lock(&l->lock); 35 sk_del_node_init(sk); 36 write_unlock(&l->lock); 37 } 38 39 void nfc_llcp_socket_remote_param_init(struct nfc_llcp_sock *sock) 40 { 41 sock->remote_rw = LLCP_DEFAULT_RW; 42 sock->remote_miu = LLCP_MAX_MIU + 1; 43 } 44 45 static void nfc_llcp_socket_purge(struct nfc_llcp_sock *sock) 46 { 47 struct nfc_llcp_local *local = sock->local; 48 struct sk_buff *s, *tmp; 49 50 skb_queue_purge(&sock->tx_queue); 51 skb_queue_purge(&sock->tx_pending_queue); 52 53 if (local == NULL) 54 return; 55 56 /* Search for local pending SKBs that are related to this socket */ 57 skb_queue_walk_safe(&local->tx_queue, s, tmp) { 58 if (s->sk != &sock->sk) 59 continue; 60 61 skb_unlink(s, &local->tx_queue); 62 kfree_skb(s); 63 } 64 } 65 66 static void nfc_llcp_socket_release(struct nfc_llcp_local *local, bool device, 67 int err) 68 { 69 struct sock *sk; 70 struct hlist_node *tmp; 71 struct nfc_llcp_sock *llcp_sock; 72 73 skb_queue_purge(&local->tx_queue); 74 75 write_lock(&local->sockets.lock); 76 77 sk_for_each_safe(sk, tmp, &local->sockets.head) { 78 llcp_sock = nfc_llcp_sock(sk); 79 80 bh_lock_sock(sk); 81 82 nfc_llcp_socket_purge(llcp_sock); 83 84 if (sk->sk_state == LLCP_CONNECTED) 85 nfc_put_device(llcp_sock->dev); 86 87 if (sk->sk_state == LLCP_LISTEN) { 88 struct nfc_llcp_sock *lsk, *n; 89 struct sock *accept_sk; 90 91 list_for_each_entry_safe(lsk, n, 92 &llcp_sock->accept_queue, 93 accept_queue) { 94 accept_sk = &lsk->sk; 95 bh_lock_sock(accept_sk); 96 97 nfc_llcp_accept_unlink(accept_sk); 98 99 if (err) 100 accept_sk->sk_err = err; 101 accept_sk->sk_state = LLCP_CLOSED; 102 accept_sk->sk_state_change(sk); 103 104 bh_unlock_sock(accept_sk); 105 } 106 } 107 108 if (err) 109 sk->sk_err = err; 110 sk->sk_state = LLCP_CLOSED; 111 sk->sk_state_change(sk); 112 113 bh_unlock_sock(sk); 114 115 sk_del_node_init(sk); 116 } 117 118 write_unlock(&local->sockets.lock); 119 120 /* If we still have a device, we keep the RAW sockets alive */ 121 if (device == true) 122 return; 123 124 write_lock(&local->raw_sockets.lock); 125 126 sk_for_each_safe(sk, tmp, &local->raw_sockets.head) { 127 llcp_sock = nfc_llcp_sock(sk); 128 129 bh_lock_sock(sk); 130 131 nfc_llcp_socket_purge(llcp_sock); 132 133 if (err) 134 sk->sk_err = err; 135 sk->sk_state = LLCP_CLOSED; 136 sk->sk_state_change(sk); 137 138 bh_unlock_sock(sk); 139 140 sk_del_node_init(sk); 141 } 142 143 write_unlock(&local->raw_sockets.lock); 144 } 145 146 static struct nfc_llcp_local *nfc_llcp_local_get(struct nfc_llcp_local *local) 147 { 148 /* Since using nfc_llcp_local may result in usage of nfc_dev, whenever 149 * we hold a reference to local, we also need to hold a reference to 150 * the device to avoid UAF. 151 */ 152 if (!nfc_get_device(local->dev->idx)) 153 return NULL; 154 155 kref_get(&local->ref); 156 157 return local; 158 } 159 160 static void local_cleanup(struct nfc_llcp_local *local) 161 { 162 nfc_llcp_socket_release(local, false, ENXIO); 163 timer_delete_sync(&local->link_timer); 164 skb_queue_purge(&local->tx_queue); 165 cancel_work_sync(&local->tx_work); 166 cancel_work_sync(&local->rx_work); 167 cancel_work_sync(&local->timeout_work); 168 kfree_skb(local->rx_pending); 169 local->rx_pending = NULL; 170 timer_delete_sync(&local->sdreq_timer); 171 cancel_work_sync(&local->sdreq_timeout_work); 172 nfc_llcp_free_sdp_tlv_list(&local->pending_sdreqs); 173 } 174 175 static void local_release(struct kref *ref) 176 { 177 struct nfc_llcp_local *local; 178 179 local = container_of(ref, struct nfc_llcp_local, ref); 180 181 local_cleanup(local); 182 kfree(local); 183 } 184 185 int nfc_llcp_local_put(struct nfc_llcp_local *local) 186 { 187 struct nfc_dev *dev; 188 int ret; 189 190 if (local == NULL) 191 return 0; 192 193 dev = local->dev; 194 195 ret = kref_put(&local->ref, local_release); 196 nfc_put_device(dev); 197 198 return ret; 199 } 200 201 static struct nfc_llcp_sock *nfc_llcp_sock_get(struct nfc_llcp_local *local, 202 u8 ssap, u8 dsap) 203 { 204 struct sock *sk; 205 struct nfc_llcp_sock *llcp_sock, *tmp_sock; 206 207 pr_debug("ssap dsap %d %d\n", ssap, dsap); 208 209 if (ssap == 0 && dsap == 0) 210 return NULL; 211 212 read_lock(&local->sockets.lock); 213 214 llcp_sock = NULL; 215 216 sk_for_each(sk, &local->sockets.head) { 217 tmp_sock = nfc_llcp_sock(sk); 218 219 if (tmp_sock->ssap == ssap && tmp_sock->dsap == dsap) { 220 llcp_sock = tmp_sock; 221 sock_hold(&llcp_sock->sk); 222 break; 223 } 224 } 225 226 read_unlock(&local->sockets.lock); 227 228 return llcp_sock; 229 } 230 231 static void nfc_llcp_sock_put(struct nfc_llcp_sock *sock) 232 { 233 sock_put(&sock->sk); 234 } 235 236 static void nfc_llcp_timeout_work(struct work_struct *work) 237 { 238 struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local, 239 timeout_work); 240 241 nfc_dep_link_down(local->dev); 242 } 243 244 static void nfc_llcp_symm_timer(struct timer_list *t) 245 { 246 struct nfc_llcp_local *local = timer_container_of(local, t, 247 link_timer); 248 249 pr_err("SYMM timeout\n"); 250 251 schedule_work(&local->timeout_work); 252 } 253 254 static void nfc_llcp_sdreq_timeout_work(struct work_struct *work) 255 { 256 unsigned long time; 257 HLIST_HEAD(nl_sdres_list); 258 struct hlist_node *n; 259 struct nfc_llcp_sdp_tlv *sdp; 260 struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local, 261 sdreq_timeout_work); 262 263 mutex_lock(&local->sdreq_lock); 264 265 time = jiffies - msecs_to_jiffies(3 * local->remote_lto); 266 267 hlist_for_each_entry_safe(sdp, n, &local->pending_sdreqs, node) { 268 if (time_after(sdp->time, time)) 269 continue; 270 271 sdp->sap = LLCP_SDP_UNBOUND; 272 273 hlist_del(&sdp->node); 274 275 hlist_add_head(&sdp->node, &nl_sdres_list); 276 } 277 278 if (!hlist_empty(&local->pending_sdreqs)) 279 mod_timer(&local->sdreq_timer, 280 jiffies + msecs_to_jiffies(3 * local->remote_lto)); 281 282 mutex_unlock(&local->sdreq_lock); 283 284 if (!hlist_empty(&nl_sdres_list)) 285 nfc_genl_llc_send_sdres(local->dev, &nl_sdres_list); 286 } 287 288 static void nfc_llcp_sdreq_timer(struct timer_list *t) 289 { 290 struct nfc_llcp_local *local = timer_container_of(local, t, 291 sdreq_timer); 292 293 schedule_work(&local->sdreq_timeout_work); 294 } 295 296 struct nfc_llcp_local *nfc_llcp_find_local(struct nfc_dev *dev) 297 { 298 struct nfc_llcp_local *local; 299 struct nfc_llcp_local *res = NULL; 300 301 spin_lock(&llcp_devices_lock); 302 list_for_each_entry(local, &llcp_devices, list) 303 if (local->dev == dev) { 304 res = nfc_llcp_local_get(local); 305 break; 306 } 307 spin_unlock(&llcp_devices_lock); 308 309 return res; 310 } 311 312 static struct nfc_llcp_local *nfc_llcp_remove_local(struct nfc_dev *dev) 313 { 314 struct nfc_llcp_local *local, *tmp; 315 316 spin_lock(&llcp_devices_lock); 317 list_for_each_entry_safe(local, tmp, &llcp_devices, list) 318 if (local->dev == dev) { 319 spin_lock(&local->tx_queue.lock); 320 list_del_init(&local->list); 321 spin_unlock(&local->tx_queue.lock); 322 spin_unlock(&llcp_devices_lock); 323 return local; 324 } 325 spin_unlock(&llcp_devices_lock); 326 327 pr_warn("Shutting down device not found\n"); 328 329 return NULL; 330 } 331 332 static char *wks[] = { 333 NULL, 334 NULL, /* SDP */ 335 "urn:nfc:sn:ip", 336 "urn:nfc:sn:obex", 337 "urn:nfc:sn:snep", 338 }; 339 340 static int nfc_llcp_wks_sap(const char *service_name, size_t service_name_len) 341 { 342 int sap, num_wks; 343 344 pr_debug("%s\n", service_name); 345 346 if (service_name == NULL) 347 return -EINVAL; 348 349 num_wks = ARRAY_SIZE(wks); 350 351 for (sap = 0; sap < num_wks; sap++) { 352 if (wks[sap] == NULL) 353 continue; 354 355 if (strncmp(wks[sap], service_name, service_name_len) == 0) 356 return sap; 357 } 358 359 return -EINVAL; 360 } 361 362 static 363 struct nfc_llcp_sock *nfc_llcp_sock_from_sn(struct nfc_llcp_local *local, 364 const u8 *sn, size_t sn_len, 365 bool needref) 366 { 367 struct sock *sk; 368 struct nfc_llcp_sock *llcp_sock, *tmp_sock; 369 370 pr_debug("sn %zd %p\n", sn_len, sn); 371 372 if (sn == NULL || sn_len == 0) 373 return NULL; 374 375 read_lock(&local->sockets.lock); 376 377 llcp_sock = NULL; 378 379 sk_for_each(sk, &local->sockets.head) { 380 tmp_sock = nfc_llcp_sock(sk); 381 382 pr_debug("llcp sock %p\n", tmp_sock); 383 384 if (tmp_sock->sk.sk_type == SOCK_STREAM && 385 tmp_sock->sk.sk_state != LLCP_LISTEN) 386 continue; 387 388 if (tmp_sock->sk.sk_type == SOCK_DGRAM && 389 tmp_sock->sk.sk_state != LLCP_BOUND) 390 continue; 391 392 if (tmp_sock->service_name == NULL || 393 tmp_sock->service_name_len == 0) 394 continue; 395 396 if (tmp_sock->service_name_len != sn_len) 397 continue; 398 399 if (memcmp(sn, tmp_sock->service_name, sn_len) == 0) { 400 llcp_sock = tmp_sock; 401 if (needref) 402 sock_hold(&llcp_sock->sk); 403 break; 404 } 405 } 406 407 read_unlock(&local->sockets.lock); 408 409 pr_debug("Found llcp sock %p\n", llcp_sock); 410 411 return llcp_sock; 412 } 413 414 u8 nfc_llcp_get_sdp_ssap(struct nfc_llcp_local *local, 415 struct nfc_llcp_sock *sock) 416 { 417 mutex_lock(&local->sdp_lock); 418 419 if (sock->service_name != NULL && sock->service_name_len > 0) { 420 int ssap = nfc_llcp_wks_sap(sock->service_name, 421 sock->service_name_len); 422 423 if (ssap > 0) { 424 pr_debug("WKS %d\n", ssap); 425 426 /* This is a WKS, let's check if it's free */ 427 if (test_bit(ssap, &local->local_wks)) { 428 mutex_unlock(&local->sdp_lock); 429 430 return LLCP_SAP_MAX; 431 } 432 433 set_bit(ssap, &local->local_wks); 434 mutex_unlock(&local->sdp_lock); 435 436 return ssap; 437 } 438 439 /* 440 * Check if there already is a non WKS socket bound 441 * to this service name. 442 */ 443 if (nfc_llcp_sock_from_sn(local, sock->service_name, 444 sock->service_name_len, 445 false) != NULL) { 446 mutex_unlock(&local->sdp_lock); 447 448 return LLCP_SAP_MAX; 449 } 450 451 mutex_unlock(&local->sdp_lock); 452 453 return LLCP_SDP_UNBOUND; 454 455 } else if (sock->ssap != 0 && sock->ssap < LLCP_WKS_NUM_SAP) { 456 if (!test_bit(sock->ssap, &local->local_wks)) { 457 set_bit(sock->ssap, &local->local_wks); 458 mutex_unlock(&local->sdp_lock); 459 460 return sock->ssap; 461 } 462 } 463 464 mutex_unlock(&local->sdp_lock); 465 466 return LLCP_SAP_MAX; 467 } 468 469 u8 nfc_llcp_get_local_ssap(struct nfc_llcp_local *local) 470 { 471 u8 local_ssap; 472 473 mutex_lock(&local->sdp_lock); 474 475 local_ssap = find_first_zero_bit(&local->local_sap, LLCP_LOCAL_NUM_SAP); 476 if (local_ssap == LLCP_LOCAL_NUM_SAP) { 477 mutex_unlock(&local->sdp_lock); 478 return LLCP_SAP_MAX; 479 } 480 481 set_bit(local_ssap, &local->local_sap); 482 483 mutex_unlock(&local->sdp_lock); 484 485 return local_ssap + LLCP_LOCAL_SAP_OFFSET; 486 } 487 488 void nfc_llcp_put_ssap(struct nfc_llcp_local *local, u8 ssap) 489 { 490 u8 local_ssap; 491 unsigned long *sdp; 492 493 if (ssap < LLCP_WKS_NUM_SAP) { 494 local_ssap = ssap; 495 sdp = &local->local_wks; 496 } else if (ssap < LLCP_LOCAL_NUM_SAP) { 497 atomic_t *client_cnt; 498 499 local_ssap = ssap - LLCP_WKS_NUM_SAP; 500 sdp = &local->local_sdp; 501 client_cnt = &local->local_sdp_cnt[local_ssap]; 502 503 pr_debug("%d clients\n", atomic_read(client_cnt)); 504 505 mutex_lock(&local->sdp_lock); 506 507 if (atomic_dec_and_test(client_cnt)) { 508 struct nfc_llcp_sock *l_sock; 509 510 pr_debug("No more clients for SAP %d\n", ssap); 511 512 clear_bit(local_ssap, sdp); 513 514 /* Find the listening sock and set it back to UNBOUND */ 515 l_sock = nfc_llcp_sock_get(local, ssap, LLCP_SAP_SDP); 516 if (l_sock) { 517 l_sock->ssap = LLCP_SDP_UNBOUND; 518 nfc_llcp_sock_put(l_sock); 519 } 520 } 521 522 mutex_unlock(&local->sdp_lock); 523 524 return; 525 } else if (ssap < LLCP_MAX_SAP) { 526 local_ssap = ssap - LLCP_LOCAL_NUM_SAP; 527 sdp = &local->local_sap; 528 } else { 529 return; 530 } 531 532 mutex_lock(&local->sdp_lock); 533 534 clear_bit(local_ssap, sdp); 535 536 mutex_unlock(&local->sdp_lock); 537 } 538 539 static u8 nfc_llcp_reserve_sdp_ssap(struct nfc_llcp_local *local) 540 { 541 u8 ssap; 542 543 mutex_lock(&local->sdp_lock); 544 545 ssap = find_first_zero_bit(&local->local_sdp, LLCP_SDP_NUM_SAP); 546 if (ssap == LLCP_SDP_NUM_SAP) { 547 mutex_unlock(&local->sdp_lock); 548 549 return LLCP_SAP_MAX; 550 } 551 552 pr_debug("SDP ssap %d\n", LLCP_WKS_NUM_SAP + ssap); 553 554 set_bit(ssap, &local->local_sdp); 555 556 mutex_unlock(&local->sdp_lock); 557 558 return LLCP_WKS_NUM_SAP + ssap; 559 } 560 561 static int nfc_llcp_build_gb(struct nfc_llcp_local *local) 562 { 563 u8 *gb_cur, version, version_length; 564 u8 lto_length, wks_length, miux_length; 565 const u8 *version_tlv = NULL, *lto_tlv = NULL, 566 *wks_tlv = NULL, *miux_tlv = NULL; 567 __be16 wks = cpu_to_be16(local->local_wks); 568 u8 gb_len = 0; 569 int ret = 0; 570 571 version = LLCP_VERSION_11; 572 version_tlv = nfc_llcp_build_tlv(LLCP_TLV_VERSION, &version, 573 1, &version_length); 574 if (!version_tlv) { 575 ret = -ENOMEM; 576 goto out; 577 } 578 gb_len += version_length; 579 580 lto_tlv = nfc_llcp_build_tlv(LLCP_TLV_LTO, &local->lto, 1, <o_length); 581 if (!lto_tlv) { 582 ret = -ENOMEM; 583 goto out; 584 } 585 gb_len += lto_length; 586 587 pr_debug("Local wks 0x%lx\n", local->local_wks); 588 wks_tlv = nfc_llcp_build_tlv(LLCP_TLV_WKS, (u8 *)&wks, 2, &wks_length); 589 if (!wks_tlv) { 590 ret = -ENOMEM; 591 goto out; 592 } 593 gb_len += wks_length; 594 595 miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&local->miux, 0, 596 &miux_length); 597 if (!miux_tlv) { 598 ret = -ENOMEM; 599 goto out; 600 } 601 gb_len += miux_length; 602 603 gb_len += ARRAY_SIZE(llcp_magic); 604 605 if (gb_len > NFC_MAX_GT_LEN) { 606 ret = -EINVAL; 607 goto out; 608 } 609 610 gb_cur = local->gb; 611 612 memcpy(gb_cur, llcp_magic, ARRAY_SIZE(llcp_magic)); 613 gb_cur += ARRAY_SIZE(llcp_magic); 614 615 memcpy(gb_cur, version_tlv, version_length); 616 gb_cur += version_length; 617 618 memcpy(gb_cur, lto_tlv, lto_length); 619 gb_cur += lto_length; 620 621 memcpy(gb_cur, wks_tlv, wks_length); 622 gb_cur += wks_length; 623 624 memcpy(gb_cur, miux_tlv, miux_length); 625 gb_cur += miux_length; 626 627 local->gb_len = gb_len; 628 629 out: 630 kfree(version_tlv); 631 kfree(lto_tlv); 632 kfree(wks_tlv); 633 kfree(miux_tlv); 634 635 return ret; 636 } 637 638 u8 *nfc_llcp_general_bytes(struct nfc_dev *dev, size_t *general_bytes_len) 639 { 640 struct nfc_llcp_local *local; 641 642 local = nfc_llcp_find_local(dev); 643 if (local == NULL) { 644 *general_bytes_len = 0; 645 return NULL; 646 } 647 648 nfc_llcp_build_gb(local); 649 650 *general_bytes_len = local->gb_len; 651 652 nfc_llcp_local_put(local); 653 654 return local->gb; 655 } 656 657 int nfc_llcp_set_remote_gb(struct nfc_dev *dev, const u8 *gb, u8 gb_len) 658 { 659 struct nfc_llcp_local *local; 660 int err; 661 662 if (gb_len < 3 || gb_len > NFC_MAX_GT_LEN) 663 return -EINVAL; 664 665 local = nfc_llcp_find_local(dev); 666 if (local == NULL) { 667 pr_err("No LLCP device\n"); 668 return -ENODEV; 669 } 670 671 memset(local->remote_gb, 0, NFC_MAX_GT_LEN); 672 memcpy(local->remote_gb, gb, gb_len); 673 local->remote_gb_len = gb_len; 674 675 if (memcmp(local->remote_gb, llcp_magic, 3)) { 676 pr_err("MAC does not support LLCP\n"); 677 err = -EINVAL; 678 goto out; 679 } 680 681 err = nfc_llcp_parse_gb_tlv(local, 682 &local->remote_gb[3], 683 local->remote_gb_len - 3); 684 out: 685 nfc_llcp_local_put(local); 686 return err; 687 } 688 689 static u8 nfc_llcp_dsap(const struct sk_buff *pdu) 690 { 691 return (pdu->data[0] & 0xfc) >> 2; 692 } 693 694 static u8 nfc_llcp_ptype(const struct sk_buff *pdu) 695 { 696 return ((pdu->data[0] & 0x03) << 2) | ((pdu->data[1] & 0xc0) >> 6); 697 } 698 699 static u8 nfc_llcp_ssap(const struct sk_buff *pdu) 700 { 701 return pdu->data[1] & 0x3f; 702 } 703 704 static u8 nfc_llcp_ns(const struct sk_buff *pdu) 705 { 706 return pdu->data[2] >> 4; 707 } 708 709 static u8 nfc_llcp_nr(const struct sk_buff *pdu) 710 { 711 return pdu->data[2] & 0xf; 712 } 713 714 static void nfc_llcp_set_nrns(struct nfc_llcp_sock *sock, struct sk_buff *pdu) 715 { 716 pdu->data[2] = (sock->send_n << 4) | (sock->recv_n); 717 sock->send_n = (sock->send_n + 1) % 16; 718 sock->recv_ack_n = (sock->recv_n - 1) % 16; 719 } 720 721 void nfc_llcp_send_to_raw_sock(struct nfc_llcp_local *local, 722 struct sk_buff *skb, u8 direction) 723 { 724 struct sk_buff *skb_copy = NULL, *nskb; 725 struct sock *sk; 726 u8 *data; 727 728 read_lock(&local->raw_sockets.lock); 729 730 sk_for_each(sk, &local->raw_sockets.head) { 731 if (sk->sk_state != LLCP_BOUND) 732 continue; 733 734 if (skb_copy == NULL) { 735 skb_copy = __pskb_copy_fclone(skb, NFC_RAW_HEADER_SIZE, 736 GFP_ATOMIC, true); 737 738 if (skb_copy == NULL) 739 continue; 740 741 data = skb_push(skb_copy, NFC_RAW_HEADER_SIZE); 742 743 data[0] = local->dev ? local->dev->idx : 0xFF; 744 data[1] = direction & 0x01; 745 data[1] |= (RAW_PAYLOAD_LLCP << 1); 746 } 747 748 nskb = skb_clone(skb_copy, GFP_ATOMIC); 749 if (!nskb) 750 continue; 751 752 if (sock_queue_rcv_skb(sk, nskb)) 753 kfree_skb(nskb); 754 } 755 756 read_unlock(&local->raw_sockets.lock); 757 758 kfree_skb(skb_copy); 759 } 760 761 static void nfc_llcp_tx_work(struct work_struct *work) 762 { 763 struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local, 764 tx_work); 765 struct sk_buff *skb; 766 struct sock *sk; 767 struct nfc_llcp_sock *llcp_sock; 768 769 skb = skb_dequeue(&local->tx_queue); 770 if (skb != NULL) { 771 sk = skb->sk; 772 llcp_sock = nfc_llcp_sock(sk); 773 774 if (llcp_sock == NULL && nfc_llcp_ptype(skb) == LLCP_PDU_I) { 775 kfree_skb(skb); 776 nfc_llcp_send_symm(local->dev); 777 } else if (llcp_sock && !llcp_sock->remote_ready) { 778 skb_queue_head(&local->tx_queue, skb); 779 nfc_llcp_send_symm(local->dev); 780 } else { 781 struct sk_buff *copy_skb = NULL; 782 u8 ptype = nfc_llcp_ptype(skb); 783 int ret; 784 785 pr_debug("Sending pending skb\n"); 786 print_hex_dump_debug("LLCP Tx: ", DUMP_PREFIX_OFFSET, 787 16, 1, skb->data, skb->len, true); 788 789 if (ptype == LLCP_PDU_I) 790 copy_skb = skb_copy(skb, GFP_ATOMIC); 791 792 __net_timestamp(skb); 793 794 nfc_llcp_send_to_raw_sock(local, skb, 795 NFC_DIRECTION_TX); 796 797 ret = nfc_data_exchange(local->dev, local->target_idx, 798 skb, nfc_llcp_recv, local); 799 800 if (ret) { 801 kfree_skb(copy_skb); 802 goto out; 803 } 804 805 if (ptype == LLCP_PDU_I && copy_skb) 806 skb_queue_tail(&llcp_sock->tx_pending_queue, 807 copy_skb); 808 } 809 } else { 810 nfc_llcp_send_symm(local->dev); 811 } 812 813 out: 814 mod_timer(&local->link_timer, 815 jiffies + msecs_to_jiffies(2 * local->remote_lto)); 816 } 817 818 static struct nfc_llcp_sock *nfc_llcp_connecting_sock_get(struct nfc_llcp_local *local, 819 u8 ssap) 820 { 821 struct sock *sk; 822 struct nfc_llcp_sock *llcp_sock; 823 824 read_lock(&local->connecting_sockets.lock); 825 826 sk_for_each(sk, &local->connecting_sockets.head) { 827 llcp_sock = nfc_llcp_sock(sk); 828 829 if (llcp_sock->ssap == ssap) { 830 sock_hold(&llcp_sock->sk); 831 goto out; 832 } 833 } 834 835 llcp_sock = NULL; 836 837 out: 838 read_unlock(&local->connecting_sockets.lock); 839 840 return llcp_sock; 841 } 842 843 static struct nfc_llcp_sock *nfc_llcp_sock_get_sn(struct nfc_llcp_local *local, 844 const u8 *sn, size_t sn_len) 845 { 846 return nfc_llcp_sock_from_sn(local, sn, sn_len, true); 847 } 848 849 static const u8 *nfc_llcp_connect_sn(const struct sk_buff *skb, size_t *sn_len) 850 { 851 u8 type, length; 852 const u8 *tlv = &skb->data[LLCP_HEADER_SIZE]; 853 const u8 *tlv_end = skb_tail_pointer(skb); 854 855 while (tlv + 2 < tlv_end) { 856 type = tlv[0]; 857 length = tlv[1]; 858 859 if (tlv + 2 + length > tlv_end) 860 break; 861 862 pr_debug("type 0x%x length %d\n", type, length); 863 864 if (type == LLCP_TLV_SN) { 865 *sn_len = length; 866 return &tlv[2]; 867 } 868 869 tlv += length + 2; 870 } 871 872 return NULL; 873 } 874 875 static void nfc_llcp_recv_ui(struct nfc_llcp_local *local, 876 struct sk_buff *skb) 877 { 878 struct nfc_llcp_sock *llcp_sock; 879 struct nfc_llcp_ui_cb *ui_cb; 880 u8 dsap, ssap; 881 882 dsap = nfc_llcp_dsap(skb); 883 ssap = nfc_llcp_ssap(skb); 884 885 ui_cb = nfc_llcp_ui_skb_cb(skb); 886 ui_cb->dsap = dsap; 887 ui_cb->ssap = ssap; 888 889 pr_debug("%d %d\n", dsap, ssap); 890 891 /* We're looking for a bound socket, not a client one */ 892 llcp_sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP); 893 if (llcp_sock == NULL || llcp_sock->sk.sk_type != SOCK_DGRAM) 894 return; 895 896 /* There is no sequence with UI frames */ 897 skb_pull(skb, LLCP_HEADER_SIZE); 898 if (!sock_queue_rcv_skb(&llcp_sock->sk, skb)) { 899 /* 900 * UI frames will be freed from the socket layer, so we 901 * need to keep them alive until someone receives them. 902 */ 903 skb_get(skb); 904 } else { 905 pr_err("Receive queue is full\n"); 906 } 907 908 nfc_llcp_sock_put(llcp_sock); 909 } 910 911 static void nfc_llcp_recv_connect(struct nfc_llcp_local *local, 912 const struct sk_buff *skb) 913 { 914 struct sock *new_sk, *parent; 915 struct nfc_llcp_sock *sock, *new_sock; 916 u8 dsap, ssap, reason; 917 918 dsap = nfc_llcp_dsap(skb); 919 ssap = nfc_llcp_ssap(skb); 920 921 pr_debug("%d %d\n", dsap, ssap); 922 923 if (dsap != LLCP_SAP_SDP) { 924 sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP); 925 if (sock == NULL || sock->sk.sk_state != LLCP_LISTEN) { 926 reason = LLCP_DM_NOBOUND; 927 goto fail; 928 } 929 } else { 930 const u8 *sn; 931 size_t sn_len; 932 933 sn = nfc_llcp_connect_sn(skb, &sn_len); 934 if (sn == NULL) { 935 reason = LLCP_DM_NOBOUND; 936 goto fail; 937 } 938 939 pr_debug("Service name length %zu\n", sn_len); 940 941 sock = nfc_llcp_sock_get_sn(local, sn, sn_len); 942 if (sock == NULL) { 943 reason = LLCP_DM_NOBOUND; 944 goto fail; 945 } 946 } 947 948 lock_sock(&sock->sk); 949 950 parent = &sock->sk; 951 952 if (sk_acceptq_is_full(parent)) { 953 reason = LLCP_DM_REJ; 954 release_sock(&sock->sk); 955 sock_put(&sock->sk); 956 goto fail; 957 } 958 959 if (sock->ssap == LLCP_SDP_UNBOUND) { 960 u8 ssap = nfc_llcp_reserve_sdp_ssap(local); 961 962 pr_debug("First client, reserving %d\n", ssap); 963 964 if (ssap == LLCP_SAP_MAX) { 965 reason = LLCP_DM_REJ; 966 release_sock(&sock->sk); 967 sock_put(&sock->sk); 968 goto fail; 969 } 970 971 sock->ssap = ssap; 972 } 973 974 new_sk = nfc_llcp_sock_alloc(NULL, parent->sk_type, GFP_ATOMIC, 0); 975 if (new_sk == NULL) { 976 reason = LLCP_DM_REJ; 977 release_sock(&sock->sk); 978 sock_put(&sock->sk); 979 goto fail; 980 } 981 982 new_sock = nfc_llcp_sock(new_sk); 983 984 new_sock->local = nfc_llcp_local_get(local); 985 if (!new_sock->local) { 986 reason = LLCP_DM_REJ; 987 sock_put(&new_sock->sk); 988 release_sock(&sock->sk); 989 sock_put(&sock->sk); 990 goto fail; 991 } 992 993 new_sock->dev = local->dev; 994 new_sock->rw = sock->rw; 995 new_sock->miux = sock->miux; 996 new_sock->nfc_protocol = sock->nfc_protocol; 997 new_sock->dsap = ssap; 998 new_sock->target_idx = local->target_idx; 999 new_sock->parent = parent; 1000 new_sock->ssap = sock->ssap; 1001 if (sock->ssap < LLCP_LOCAL_NUM_SAP && sock->ssap >= LLCP_WKS_NUM_SAP) { 1002 atomic_t *client_count; 1003 1004 pr_debug("reserved_ssap %d for %p\n", sock->ssap, new_sock); 1005 1006 client_count = 1007 &local->local_sdp_cnt[sock->ssap - LLCP_WKS_NUM_SAP]; 1008 1009 atomic_inc(client_count); 1010 new_sock->reserved_ssap = sock->ssap; 1011 } 1012 1013 nfc_llcp_parse_connection_tlv(new_sock, &skb->data[LLCP_HEADER_SIZE], 1014 skb->len - LLCP_HEADER_SIZE); 1015 1016 pr_debug("new sock %p sk %p\n", new_sock, &new_sock->sk); 1017 1018 nfc_llcp_sock_link(&local->sockets, new_sk); 1019 1020 nfc_llcp_accept_enqueue(&sock->sk, new_sk); 1021 1022 nfc_get_device(local->dev->idx); 1023 1024 new_sk->sk_state = LLCP_CONNECTED; 1025 1026 /* Wake the listening processes */ 1027 parent->sk_data_ready(parent); 1028 1029 /* Send CC */ 1030 nfc_llcp_send_cc(new_sock); 1031 1032 release_sock(&sock->sk); 1033 sock_put(&sock->sk); 1034 1035 return; 1036 1037 fail: 1038 /* Send DM */ 1039 nfc_llcp_send_dm(local, dsap, ssap, reason); 1040 } 1041 1042 int nfc_llcp_queue_i_frames(struct nfc_llcp_sock *sock) 1043 { 1044 int nr_frames = 0; 1045 struct nfc_llcp_local *local = sock->local; 1046 1047 pr_debug("Remote ready %d tx queue len %d remote rw %d", 1048 sock->remote_ready, skb_queue_len(&sock->tx_pending_queue), 1049 sock->remote_rw); 1050 1051 /* Try to queue some I frames for transmission */ 1052 while (sock->remote_ready && 1053 skb_queue_len(&sock->tx_pending_queue) < sock->remote_rw) { 1054 struct sk_buff *pdu; 1055 1056 pdu = skb_dequeue(&sock->tx_queue); 1057 if (pdu == NULL) 1058 break; 1059 1060 /* Update N(S)/N(R) */ 1061 nfc_llcp_set_nrns(sock, pdu); 1062 1063 skb_queue_tail(&local->tx_queue, pdu); 1064 nr_frames++; 1065 } 1066 1067 return nr_frames; 1068 } 1069 1070 static void nfc_llcp_recv_hdlc(struct nfc_llcp_local *local, 1071 struct sk_buff *skb) 1072 { 1073 struct nfc_llcp_sock *llcp_sock; 1074 struct sock *sk; 1075 u8 dsap, ssap, ptype, ns, nr; 1076 1077 ptype = nfc_llcp_ptype(skb); 1078 dsap = nfc_llcp_dsap(skb); 1079 ssap = nfc_llcp_ssap(skb); 1080 ns = nfc_llcp_ns(skb); 1081 nr = nfc_llcp_nr(skb); 1082 1083 pr_debug("%d %d R %d S %d\n", dsap, ssap, nr, ns); 1084 1085 llcp_sock = nfc_llcp_sock_get(local, dsap, ssap); 1086 if (llcp_sock == NULL) { 1087 nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN); 1088 return; 1089 } 1090 1091 sk = &llcp_sock->sk; 1092 lock_sock(sk); 1093 if (sk->sk_state == LLCP_CLOSED) { 1094 release_sock(sk); 1095 nfc_llcp_sock_put(llcp_sock); 1096 return; 1097 } 1098 1099 /* Pass the payload upstream */ 1100 if (ptype == LLCP_PDU_I) { 1101 pr_debug("I frame, queueing on %p\n", &llcp_sock->sk); 1102 1103 if (ns == llcp_sock->recv_n) 1104 llcp_sock->recv_n = (llcp_sock->recv_n + 1) % 16; 1105 else 1106 pr_err("Received out of sequence I PDU\n"); 1107 1108 skb_pull(skb, LLCP_HEADER_SIZE + LLCP_SEQUENCE_SIZE); 1109 if (!sock_queue_rcv_skb(&llcp_sock->sk, skb)) { 1110 /* 1111 * I frames will be freed from the socket layer, so we 1112 * need to keep them alive until someone receives them. 1113 */ 1114 skb_get(skb); 1115 } else { 1116 pr_err("Receive queue is full\n"); 1117 } 1118 } 1119 1120 /* Remove skbs from the pending queue */ 1121 if (llcp_sock->send_ack_n != nr) { 1122 struct sk_buff *s, *tmp; 1123 u8 n; 1124 1125 llcp_sock->send_ack_n = nr; 1126 1127 /* Remove and free all skbs until ns == nr */ 1128 skb_queue_walk_safe(&llcp_sock->tx_pending_queue, s, tmp) { 1129 n = nfc_llcp_ns(s); 1130 1131 skb_unlink(s, &llcp_sock->tx_pending_queue); 1132 kfree_skb(s); 1133 1134 if (n == nr) 1135 break; 1136 } 1137 1138 /* Re-queue the remaining skbs for transmission */ 1139 skb_queue_reverse_walk_safe(&llcp_sock->tx_pending_queue, 1140 s, tmp) { 1141 skb_unlink(s, &llcp_sock->tx_pending_queue); 1142 skb_queue_head(&local->tx_queue, s); 1143 } 1144 } 1145 1146 if (ptype == LLCP_PDU_RR) 1147 llcp_sock->remote_ready = true; 1148 else if (ptype == LLCP_PDU_RNR) 1149 llcp_sock->remote_ready = false; 1150 1151 if (nfc_llcp_queue_i_frames(llcp_sock) == 0 && ptype == LLCP_PDU_I) 1152 nfc_llcp_send_rr(llcp_sock); 1153 1154 release_sock(sk); 1155 nfc_llcp_sock_put(llcp_sock); 1156 } 1157 1158 static void nfc_llcp_recv_disc(struct nfc_llcp_local *local, 1159 const struct sk_buff *skb) 1160 { 1161 struct nfc_llcp_sock *llcp_sock; 1162 struct sock *sk; 1163 u8 dsap, ssap; 1164 1165 dsap = nfc_llcp_dsap(skb); 1166 ssap = nfc_llcp_ssap(skb); 1167 1168 if ((dsap == 0) && (ssap == 0)) { 1169 pr_debug("Connection termination"); 1170 nfc_dep_link_down(local->dev); 1171 return; 1172 } 1173 1174 llcp_sock = nfc_llcp_sock_get(local, dsap, ssap); 1175 if (llcp_sock == NULL) { 1176 nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN); 1177 return; 1178 } 1179 1180 sk = &llcp_sock->sk; 1181 lock_sock(sk); 1182 1183 nfc_llcp_socket_purge(llcp_sock); 1184 1185 if (sk->sk_state == LLCP_CLOSED) { 1186 release_sock(sk); 1187 nfc_llcp_sock_put(llcp_sock); 1188 return; 1189 } 1190 1191 if (sk->sk_state == LLCP_CONNECTED) { 1192 nfc_put_device(local->dev); 1193 sk->sk_state = LLCP_CLOSED; 1194 sk->sk_state_change(sk); 1195 } 1196 1197 nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_DISC); 1198 1199 release_sock(sk); 1200 nfc_llcp_sock_put(llcp_sock); 1201 } 1202 1203 static void nfc_llcp_recv_cc(struct nfc_llcp_local *local, 1204 const struct sk_buff *skb) 1205 { 1206 struct nfc_llcp_sock *llcp_sock; 1207 struct sock *sk; 1208 u8 dsap, ssap; 1209 1210 dsap = nfc_llcp_dsap(skb); 1211 ssap = nfc_llcp_ssap(skb); 1212 1213 llcp_sock = nfc_llcp_connecting_sock_get(local, dsap); 1214 if (llcp_sock == NULL) { 1215 pr_err("Invalid CC\n"); 1216 nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN); 1217 1218 return; 1219 } 1220 1221 sk = &llcp_sock->sk; 1222 1223 lock_sock(sk); 1224 1225 /* Check if socket was destroyed whilst waiting for the lock */ 1226 if (!sk_hashed(sk)) { 1227 release_sock(sk); 1228 nfc_llcp_sock_put(llcp_sock); 1229 return; 1230 } 1231 1232 /* Unlink from connecting and link to the client array */ 1233 nfc_llcp_sock_unlink(&local->connecting_sockets, sk); 1234 nfc_llcp_sock_link(&local->sockets, sk); 1235 llcp_sock->dsap = ssap; 1236 1237 nfc_llcp_parse_connection_tlv(llcp_sock, &skb->data[LLCP_HEADER_SIZE], 1238 skb->len - LLCP_HEADER_SIZE); 1239 1240 sk->sk_state = LLCP_CONNECTED; 1241 sk->sk_state_change(sk); 1242 1243 release_sock(sk); 1244 1245 nfc_llcp_sock_put(llcp_sock); 1246 } 1247 1248 static void nfc_llcp_recv_dm(struct nfc_llcp_local *local, 1249 const struct sk_buff *skb) 1250 { 1251 struct nfc_llcp_sock *llcp_sock; 1252 struct sock *sk; 1253 u8 dsap, ssap, reason; 1254 1255 dsap = nfc_llcp_dsap(skb); 1256 ssap = nfc_llcp_ssap(skb); 1257 reason = skb->data[2]; 1258 1259 pr_debug("%d %d reason %d\n", ssap, dsap, reason); 1260 1261 switch (reason) { 1262 case LLCP_DM_NOBOUND: 1263 case LLCP_DM_REJ: 1264 llcp_sock = nfc_llcp_connecting_sock_get(local, dsap); 1265 break; 1266 1267 default: 1268 llcp_sock = nfc_llcp_sock_get(local, dsap, ssap); 1269 break; 1270 } 1271 1272 if (llcp_sock == NULL) { 1273 pr_debug("Already closed\n"); 1274 return; 1275 } 1276 1277 sk = &llcp_sock->sk; 1278 1279 sk->sk_err = ENXIO; 1280 sk->sk_state = LLCP_CLOSED; 1281 sk->sk_state_change(sk); 1282 1283 nfc_llcp_sock_put(llcp_sock); 1284 } 1285 1286 static void nfc_llcp_recv_snl(struct nfc_llcp_local *local, 1287 const struct sk_buff *skb) 1288 { 1289 struct nfc_llcp_sock *llcp_sock; 1290 u8 dsap, ssap, type, length, tid, sap; 1291 const u8 *tlv, *tlv_end; 1292 const char *service_name; 1293 int service_name_len; 1294 struct nfc_llcp_sdp_tlv *sdp; 1295 HLIST_HEAD(llc_sdres_list); 1296 size_t sdres_tlvs_len; 1297 HLIST_HEAD(nl_sdres_list); 1298 1299 dsap = nfc_llcp_dsap(skb); 1300 ssap = nfc_llcp_ssap(skb); 1301 1302 pr_debug("%d %d\n", dsap, ssap); 1303 1304 if (dsap != LLCP_SAP_SDP || ssap != LLCP_SAP_SDP) { 1305 pr_err("Wrong SNL SAP\n"); 1306 return; 1307 } 1308 1309 /* 1310 * Walk the SNL TLV list in the linear part of the skb only, 1311 * bounded by skb_tail_pointer(). Each TLV needs a two-byte 1312 * header (type, length) and its declared length must fit before 1313 * the end; this also keeps the walk safe for very short frames. 1314 */ 1315 tlv = &skb->data[LLCP_HEADER_SIZE]; 1316 tlv_end = skb_tail_pointer(skb); 1317 sdres_tlvs_len = 0; 1318 1319 while (tlv + 2 < tlv_end) { 1320 type = tlv[0]; 1321 length = tlv[1]; 1322 1323 if (tlv + 2 + length > tlv_end) 1324 break; 1325 1326 switch (type) { 1327 case LLCP_TLV_SDREQ: 1328 if (length < 1) 1329 break; 1330 1331 tid = tlv[2]; 1332 service_name = (char *) &tlv[3]; 1333 service_name_len = length - 1; 1334 1335 pr_debug("Looking for %.*s\n", service_name_len, 1336 service_name); 1337 1338 if (service_name_len == strlen("urn:nfc:sn:sdp") && 1339 !strncmp(service_name, "urn:nfc:sn:sdp", 1340 service_name_len)) { 1341 sap = 1; 1342 goto add_snl; 1343 } 1344 1345 llcp_sock = nfc_llcp_sock_from_sn(local, service_name, 1346 service_name_len, 1347 true); 1348 if (!llcp_sock) { 1349 sap = 0; 1350 goto add_snl; 1351 } 1352 1353 /* 1354 * We found a socket but its ssap has not been reserved 1355 * yet. We need to assign it for good and send a reply. 1356 * The ssap will be freed when the socket is closed. 1357 */ 1358 if (llcp_sock->ssap == LLCP_SDP_UNBOUND) { 1359 atomic_t *client_count; 1360 1361 sap = nfc_llcp_reserve_sdp_ssap(local); 1362 1363 pr_debug("Reserving %d\n", sap); 1364 1365 if (sap == LLCP_SAP_MAX) { 1366 sap = 0; 1367 nfc_llcp_sock_put(llcp_sock); 1368 goto add_snl; 1369 } 1370 1371 client_count = 1372 &local->local_sdp_cnt[sap - 1373 LLCP_WKS_NUM_SAP]; 1374 1375 atomic_inc(client_count); 1376 1377 llcp_sock->ssap = sap; 1378 llcp_sock->reserved_ssap = sap; 1379 } else { 1380 sap = llcp_sock->ssap; 1381 } 1382 1383 pr_debug("%p %d\n", llcp_sock, sap); 1384 1385 nfc_llcp_sock_put(llcp_sock); 1386 add_snl: 1387 sdp = nfc_llcp_build_sdres_tlv(tid, sap); 1388 if (sdp == NULL) 1389 goto exit; 1390 1391 sdres_tlvs_len += sdp->tlv_len; 1392 hlist_add_head(&sdp->node, &llc_sdres_list); 1393 break; 1394 1395 case LLCP_TLV_SDRES: 1396 if (length != 2) 1397 break; 1398 1399 mutex_lock(&local->sdreq_lock); 1400 1401 pr_debug("LLCP_TLV_SDRES: searching tid %d\n", tlv[2]); 1402 1403 hlist_for_each_entry(sdp, &local->pending_sdreqs, node) { 1404 if (sdp->tid != tlv[2]) 1405 continue; 1406 1407 sdp->sap = tlv[3]; 1408 1409 pr_debug("Found: uri=%s, sap=%d\n", 1410 sdp->uri, sdp->sap); 1411 1412 hlist_del(&sdp->node); 1413 1414 hlist_add_head(&sdp->node, &nl_sdres_list); 1415 1416 break; 1417 } 1418 1419 mutex_unlock(&local->sdreq_lock); 1420 break; 1421 1422 default: 1423 pr_err("Invalid SNL tlv value 0x%x\n", type); 1424 break; 1425 } 1426 1427 tlv += length + 2; 1428 } 1429 1430 exit: 1431 if (!hlist_empty(&nl_sdres_list)) 1432 nfc_genl_llc_send_sdres(local->dev, &nl_sdres_list); 1433 1434 if (!hlist_empty(&llc_sdres_list)) 1435 nfc_llcp_send_snl_sdres(local, &llc_sdres_list, sdres_tlvs_len); 1436 } 1437 1438 static void nfc_llcp_recv_agf(struct nfc_llcp_local *local, struct sk_buff *skb) 1439 { 1440 u8 ptype; 1441 u16 pdu_len; 1442 struct sk_buff *new_skb; 1443 1444 if (skb->len <= LLCP_HEADER_SIZE) { 1445 pr_err("Malformed AGF PDU\n"); 1446 return; 1447 } 1448 1449 skb_pull(skb, LLCP_HEADER_SIZE); 1450 1451 while (skb->len > LLCP_AGF_PDU_HEADER_SIZE) { 1452 pdu_len = skb->data[0] << 8 | skb->data[1]; 1453 1454 skb_pull(skb, LLCP_AGF_PDU_HEADER_SIZE); 1455 1456 if (pdu_len < LLCP_HEADER_SIZE || pdu_len > skb->len) { 1457 pr_err("Malformed AGF PDU\n"); 1458 return; 1459 } 1460 1461 ptype = nfc_llcp_ptype(skb); 1462 1463 if (ptype == LLCP_PDU_SYMM || ptype == LLCP_PDU_AGF) 1464 goto next; 1465 1466 new_skb = nfc_alloc_recv_skb(pdu_len, GFP_KERNEL); 1467 if (new_skb == NULL) { 1468 pr_err("Could not allocate PDU\n"); 1469 return; 1470 } 1471 1472 skb_put_data(new_skb, skb->data, pdu_len); 1473 1474 nfc_llcp_rx_skb(local, new_skb); 1475 1476 kfree_skb(new_skb); 1477 next: 1478 skb_pull(skb, pdu_len); 1479 } 1480 } 1481 1482 static void nfc_llcp_rx_skb(struct nfc_llcp_local *local, struct sk_buff *skb) 1483 { 1484 u8 dsap, ssap, ptype; 1485 1486 ptype = nfc_llcp_ptype(skb); 1487 dsap = nfc_llcp_dsap(skb); 1488 ssap = nfc_llcp_ssap(skb); 1489 1490 pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap); 1491 1492 if (ptype != LLCP_PDU_SYMM) 1493 print_hex_dump_debug("LLCP Rx: ", DUMP_PREFIX_OFFSET, 16, 1, 1494 skb->data, skb->len, true); 1495 1496 switch (ptype) { 1497 case LLCP_PDU_SYMM: 1498 pr_debug("SYMM\n"); 1499 break; 1500 1501 case LLCP_PDU_UI: 1502 pr_debug("UI\n"); 1503 nfc_llcp_recv_ui(local, skb); 1504 break; 1505 1506 case LLCP_PDU_CONNECT: 1507 pr_debug("CONNECT\n"); 1508 nfc_llcp_recv_connect(local, skb); 1509 break; 1510 1511 case LLCP_PDU_DISC: 1512 pr_debug("DISC\n"); 1513 nfc_llcp_recv_disc(local, skb); 1514 break; 1515 1516 case LLCP_PDU_CC: 1517 pr_debug("CC\n"); 1518 nfc_llcp_recv_cc(local, skb); 1519 break; 1520 1521 case LLCP_PDU_DM: 1522 pr_debug("DM\n"); 1523 nfc_llcp_recv_dm(local, skb); 1524 break; 1525 1526 case LLCP_PDU_SNL: 1527 pr_debug("SNL\n"); 1528 nfc_llcp_recv_snl(local, skb); 1529 break; 1530 1531 case LLCP_PDU_I: 1532 case LLCP_PDU_RR: 1533 case LLCP_PDU_RNR: 1534 pr_debug("I frame\n"); 1535 nfc_llcp_recv_hdlc(local, skb); 1536 break; 1537 1538 case LLCP_PDU_AGF: 1539 pr_debug("AGF frame\n"); 1540 nfc_llcp_recv_agf(local, skb); 1541 break; 1542 } 1543 } 1544 1545 static void nfc_llcp_rx_work(struct work_struct *work) 1546 { 1547 struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local, 1548 rx_work); 1549 struct sk_buff *skb; 1550 1551 skb = local->rx_pending; 1552 if (skb == NULL) { 1553 pr_debug("No pending SKB\n"); 1554 return; 1555 } 1556 1557 __net_timestamp(skb); 1558 1559 nfc_llcp_send_to_raw_sock(local, skb, NFC_DIRECTION_RX); 1560 1561 nfc_llcp_rx_skb(local, skb); 1562 1563 schedule_work(&local->tx_work); 1564 kfree_skb(local->rx_pending); 1565 local->rx_pending = NULL; 1566 } 1567 1568 static void __nfc_llcp_recv(struct nfc_llcp_local *local, struct sk_buff *skb) 1569 { 1570 if (!pskb_may_pull(skb, LLCP_HEADER_SIZE)) { 1571 kfree_skb(skb); 1572 return; 1573 } 1574 1575 local->rx_pending = skb; 1576 timer_delete(&local->link_timer); 1577 schedule_work(&local->rx_work); 1578 } 1579 1580 void nfc_llcp_recv(void *data, struct sk_buff *skb, int err) 1581 { 1582 struct nfc_llcp_local *local = (struct nfc_llcp_local *) data; 1583 1584 if (err < 0) { 1585 pr_err("LLCP PDU receive err %d\n", err); 1586 return; 1587 } 1588 1589 __nfc_llcp_recv(local, skb); 1590 } 1591 1592 int nfc_llcp_data_received(struct nfc_dev *dev, struct sk_buff *skb) 1593 { 1594 struct nfc_llcp_local *local; 1595 1596 local = nfc_llcp_find_local(dev); 1597 if (local == NULL) { 1598 kfree_skb(skb); 1599 return -ENODEV; 1600 } 1601 1602 __nfc_llcp_recv(local, skb); 1603 1604 nfc_llcp_local_put(local); 1605 1606 return 0; 1607 } 1608 1609 void nfc_llcp_mac_is_down(struct nfc_dev *dev) 1610 { 1611 struct nfc_llcp_local *local; 1612 1613 local = nfc_llcp_find_local(dev); 1614 if (local == NULL) 1615 return; 1616 1617 local->remote_miu = LLCP_DEFAULT_MIU; 1618 local->remote_lto = LLCP_DEFAULT_LTO; 1619 1620 /* Close and purge all existing sockets */ 1621 nfc_llcp_socket_release(local, true, 0); 1622 1623 nfc_llcp_local_put(local); 1624 } 1625 1626 void nfc_llcp_mac_is_up(struct nfc_dev *dev, u32 target_idx, 1627 u8 comm_mode, u8 rf_mode) 1628 { 1629 struct nfc_llcp_local *local; 1630 1631 pr_debug("rf mode %d\n", rf_mode); 1632 1633 local = nfc_llcp_find_local(dev); 1634 if (local == NULL) 1635 return; 1636 1637 local->target_idx = target_idx; 1638 local->comm_mode = comm_mode; 1639 local->rf_mode = rf_mode; 1640 1641 if (rf_mode == NFC_RF_INITIATOR) { 1642 pr_debug("Queueing Tx work\n"); 1643 1644 schedule_work(&local->tx_work); 1645 } else { 1646 mod_timer(&local->link_timer, 1647 jiffies + msecs_to_jiffies(local->remote_lto)); 1648 } 1649 1650 nfc_llcp_local_put(local); 1651 } 1652 1653 int nfc_llcp_register_device(struct nfc_dev *ndev) 1654 { 1655 struct nfc_llcp_local *local; 1656 1657 local = kzalloc_obj(struct nfc_llcp_local); 1658 if (local == NULL) 1659 return -ENOMEM; 1660 1661 /* As we are going to initialize local's refcount, we need to get the 1662 * nfc_dev to avoid UAF, otherwise there is no point in continuing. 1663 * See nfc_llcp_local_get(). 1664 */ 1665 local->dev = nfc_get_device(ndev->idx); 1666 if (!local->dev) { 1667 kfree(local); 1668 return -ENODEV; 1669 } 1670 1671 INIT_LIST_HEAD(&local->list); 1672 kref_init(&local->ref); 1673 mutex_init(&local->sdp_lock); 1674 timer_setup(&local->link_timer, nfc_llcp_symm_timer, 0); 1675 1676 skb_queue_head_init(&local->tx_queue); 1677 INIT_WORK(&local->tx_work, nfc_llcp_tx_work); 1678 1679 local->rx_pending = NULL; 1680 INIT_WORK(&local->rx_work, nfc_llcp_rx_work); 1681 1682 INIT_WORK(&local->timeout_work, nfc_llcp_timeout_work); 1683 1684 rwlock_init(&local->sockets.lock); 1685 rwlock_init(&local->connecting_sockets.lock); 1686 rwlock_init(&local->raw_sockets.lock); 1687 1688 local->lto = 150; /* 1500 ms */ 1689 local->rw = LLCP_MAX_RW; 1690 local->miux = cpu_to_be16(LLCP_MAX_MIUX); 1691 local->local_wks = 0x1; /* LLC Link Management */ 1692 1693 nfc_llcp_build_gb(local); 1694 1695 local->remote_miu = LLCP_DEFAULT_MIU; 1696 local->remote_lto = LLCP_DEFAULT_LTO; 1697 1698 mutex_init(&local->sdreq_lock); 1699 INIT_HLIST_HEAD(&local->pending_sdreqs); 1700 timer_setup(&local->sdreq_timer, nfc_llcp_sdreq_timer, 0); 1701 INIT_WORK(&local->sdreq_timeout_work, nfc_llcp_sdreq_timeout_work); 1702 1703 spin_lock(&llcp_devices_lock); 1704 list_add(&local->list, &llcp_devices); 1705 spin_unlock(&llcp_devices_lock); 1706 1707 return 0; 1708 } 1709 1710 void nfc_llcp_unregister_device(struct nfc_dev *dev) 1711 { 1712 struct nfc_llcp_local *local = nfc_llcp_remove_local(dev); 1713 1714 if (local == NULL) { 1715 pr_debug("No such device\n"); 1716 return; 1717 } 1718 1719 local_cleanup(local); 1720 1721 nfc_llcp_local_put(local); 1722 } 1723 1724 int __init nfc_llcp_init(void) 1725 { 1726 return nfc_llcp_sock_init(); 1727 } 1728 1729 void nfc_llcp_exit(void) 1730 { 1731 nfc_llcp_sock_exit(); 1732 } 1733