net/nfc/llcp_core.c

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