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