net/nfc/llcp_core.c

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