net/nfc/llcp/llcp.c

   1 /*
   2  * Copyright (C) 2011  Intel Corporation. All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the
  16  * Free Software Foundation, Inc.,
  17  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  18  */
  19
  20 #define pr_fmt(fmt) "llcp: %s: " fmt, __func__
  21
  22 #include <linux/init.h>
  23 #include <linux/kernel.h>
  24 #include <linux/list.h>
  25 #include <linux/nfc.h>
  26
  27 #include "../nfc.h"
  28 #include "llcp.h"
  29
  30 static u8 llcp_magic[3] = {0x46, 0x66, 0x6d};
  31
  32 static struct list_head llcp_devices;
  33
  34 void nfc_llcp_sock_link(struct llcp_sock_list *l, struct sock *sk)
  35 {
  36         write_lock(&l->lock);
  37         sk_add_node(sk, &l->head);
  38         write_unlock(&l->lock);
  39 }
  40
  41 void nfc_llcp_sock_unlink(struct llcp_sock_list *l, struct sock *sk)
  42 {
  43         write_lock(&l->lock);
  44         sk_del_node_init(sk);
  45         write_unlock(&l->lock);
  46 }
  47
  48 static void nfc_llcp_socket_release(struct nfc_llcp_local *local, bool listen)
  49 {
  50         struct sock *sk;
  51         struct hlist_node *node, *tmp;
  52         struct nfc_llcp_sock *llcp_sock;
  53
  54         write_lock(&local->sockets.lock);
  55
  56         sk_for_each_safe(sk, node, tmp, &local->sockets.head) {
  57                 llcp_sock = nfc_llcp_sock(sk);
  58
  59                 bh_lock_sock(sk);
  60
  61                 if (sk->sk_state == LLCP_CONNECTED)
  62                         nfc_put_device(llcp_sock->dev);
  63
  64                 if (sk->sk_state == LLCP_LISTEN) {
  65                         struct nfc_llcp_sock *lsk, *n;
  66                         struct sock *accept_sk;
  67
  68                         list_for_each_entry_safe(lsk, n, &llcp_sock->accept_queue,
  69                                                  accept_queue) {
  70                                 accept_sk = &lsk->sk;
  71                                 bh_lock_sock(accept_sk);
  72
  73                                 nfc_llcp_accept_unlink(accept_sk);
  74
  75                                 accept_sk->sk_state = LLCP_CLOSED;
  76
  77                                 bh_unlock_sock(accept_sk);
  78
  79                                 sock_orphan(accept_sk);
  80                         }
  81
  82                         if (listen == true) {
  83                                 bh_unlock_sock(sk);
  84                                 continue;
  85                         }
  86                 }
  87
  88                 sk->sk_state = LLCP_CLOSED;
  89
  90                 bh_unlock_sock(sk);
  91
  92                 sock_orphan(sk);
  93
  94                 sk_del_node_init(sk);
  95         }
  96
  97         write_unlock(&local->sockets.lock);
  98 }
  99
 100 struct nfc_llcp_local *nfc_llcp_local_get(struct nfc_llcp_local *local)
 101 {
 102         kref_get(&local->ref);
 103
 104         return local;
 105 }
 106
 107 static void local_release(struct kref *ref)
 108 {
 109         struct nfc_llcp_local *local;
 110
 111         local = container_of(ref, struct nfc_llcp_local, ref);
 112
 113         list_del(&local->list);
 114         nfc_llcp_socket_release(local, false);
 115         del_timer_sync(&local->link_timer);
 116         skb_queue_purge(&local->tx_queue);
 117         cancel_work_sync(&local->tx_work);
 118         cancel_work_sync(&local->rx_work);
 119         cancel_work_sync(&local->timeout_work);
 120         kfree_skb(local->rx_pending);
 121         kfree(local);
 122 }
 123
 124 int nfc_llcp_local_put(struct nfc_llcp_local *local)
 125 {
 126         if (local == NULL)
 127                 return 0;
 128
 129         return kref_put(&local->ref, local_release);
 130 }
 131
 132 static struct nfc_llcp_sock *nfc_llcp_sock_get(struct nfc_llcp_local *local,
 133                                                u8 ssap, u8 dsap)
 134 {
 135         struct sock *sk;
 136         struct hlist_node *node;
 137         struct nfc_llcp_sock *llcp_sock;
 138
 139         pr_debug("ssap dsap %d %d\n", ssap, dsap);
 140
 141         if (ssap == 0 && dsap == 0)
 142                 return NULL;
 143
 144         read_lock(&local->sockets.lock);
 145
 146         llcp_sock = NULL;
 147
 148         sk_for_each(sk, node, &local->sockets.head) {
 149                 llcp_sock = nfc_llcp_sock(sk);
 150
 151                 if (llcp_sock->ssap == ssap && llcp_sock->dsap == dsap)
 152                         break;
 153         }
 154
 155         read_unlock(&local->sockets.lock);
 156
 157         if (llcp_sock == NULL)
 158                 return NULL;
 159
 160         sock_hold(&llcp_sock->sk);
 161
 162         return llcp_sock;
 163 }
 164
 165 static void nfc_llcp_sock_put(struct nfc_llcp_sock *sock)
 166 {
 167         sock_put(&sock->sk);
 168 }
 169
 170 static void nfc_llcp_timeout_work(struct work_struct *work)
 171 {
 172         struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
 173                                                     timeout_work);
 174
 175         nfc_dep_link_down(local->dev);
 176 }
 177
 178 static void nfc_llcp_symm_timer(unsigned long data)
 179 {
 180         struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
 181
 182         pr_err("SYMM timeout\n");
 183
 184         schedule_work(&local->timeout_work);
 185 }
 186
 187 struct nfc_llcp_local *nfc_llcp_find_local(struct nfc_dev *dev)
 188 {
 189         struct nfc_llcp_local *local, *n;
 190
 191         list_for_each_entry_safe(local, n, &llcp_devices, list)
 192                 if (local->dev == dev)
 193                         return local;
 194
 195         pr_debug("No device found\n");
 196
 197         return NULL;
 198 }
 199
 200 static char *wks[] = {
 201         NULL,
 202         NULL, /* SDP */
 203         "urn:nfc:sn:ip",
 204         "urn:nfc:sn:obex",
 205         "urn:nfc:sn:snep",
 206 };
 207
 208 static int nfc_llcp_wks_sap(char *service_name, size_t service_name_len)
 209 {
 210         int sap, num_wks;
 211
 212         pr_debug("%s\n", service_name);
 213
 214         if (service_name == NULL)
 215                 return -EINVAL;
 216
 217         num_wks = ARRAY_SIZE(wks);
 218
 219         for (sap = 0; sap < num_wks; sap++) {
 220                 if (wks[sap] == NULL)
 221                         continue;
 222
 223                 if (strncmp(wks[sap], service_name, service_name_len) == 0)
 224                         return sap;
 225         }
 226
 227         return -EINVAL;
 228 }
 229
 230 static
 231 struct nfc_llcp_sock *nfc_llcp_sock_from_sn(struct nfc_llcp_local *local,
 232                                             u8 *sn, size_t sn_len)
 233 {
 234         struct sock *sk;
 235         struct hlist_node *node;
 236         struct nfc_llcp_sock *llcp_sock, *tmp_sock;
 237
 238         pr_debug("sn %zd %p\n", sn_len, sn);
 239
 240         if (sn == NULL || sn_len == 0)
 241                 return NULL;
 242
 243         read_lock(&local->sockets.lock);
 244
 245         llcp_sock = NULL;
 246
 247         sk_for_each(sk, node, &local->sockets.head) {
 248                 tmp_sock = nfc_llcp_sock(sk);
 249
 250                 pr_debug("llcp sock %p\n", tmp_sock);
 251
 252                 if (tmp_sock->sk.sk_type == SOCK_STREAM &&
 253                     tmp_sock->sk.sk_state != LLCP_LISTEN)
 254                         continue;
 255
 256                 if (tmp_sock->sk.sk_type == SOCK_DGRAM &&
 257                     tmp_sock->sk.sk_state != LLCP_BOUND)
 258                         continue;
 259
 260                 if (tmp_sock->service_name == NULL ||
 261                     tmp_sock->service_name_len == 0)
 262                         continue;
 263
 264                 if (tmp_sock->service_name_len != sn_len)
 265                         continue;
 266
 267                 if (memcmp(sn, tmp_sock->service_name, sn_len) == 0) {
 268                         llcp_sock = tmp_sock;
 269                         break;
 270                 }
 271         }
 272
 273         read_unlock(&local->sockets.lock);
 274
 275         pr_debug("Found llcp sock %p\n", llcp_sock);
 276
 277         return llcp_sock;
 278 }
 279
 280 u8 nfc_llcp_get_sdp_ssap(struct nfc_llcp_local *local,
 281                          struct nfc_llcp_sock *sock)
 282 {
 283         mutex_lock(&local->sdp_lock);
 284
 285         if (sock->service_name != NULL && sock->service_name_len > 0) {
 286                 int ssap = nfc_llcp_wks_sap(sock->service_name,
 287                                             sock->service_name_len);
 288
 289                 if (ssap > 0) {
 290                         pr_debug("WKS %d\n", ssap);
 291
 292                         /* This is a WKS, let's check if it's free */
 293                         if (local->local_wks & BIT(ssap)) {
 294                                 mutex_unlock(&local->sdp_lock);
 295
 296                                 return LLCP_SAP_MAX;
 297                         }
 298
 299                         set_bit(ssap, &local->local_wks);
 300                         mutex_unlock(&local->sdp_lock);
 301
 302                         return ssap;
 303                 }
 304
 305                 /*
 306                  * Check if there already is a non WKS socket bound
 307                  * to this service name.
 308                  */
 309                 if (nfc_llcp_sock_from_sn(local, sock->service_name,
 310                                           sock->service_name_len) != NULL) {
 311                         mutex_unlock(&local->sdp_lock);
 312
 313                         return LLCP_SAP_MAX;
 314                 }
 315
 316                 mutex_unlock(&local->sdp_lock);
 317
 318                 return LLCP_SDP_UNBOUND;
 319
 320         } else if (sock->ssap != 0 && sock->ssap < LLCP_WKS_NUM_SAP) {
 321                 if (!test_bit(sock->ssap, &local->local_wks)) {
 322                         set_bit(sock->ssap, &local->local_wks);
 323                         mutex_unlock(&local->sdp_lock);
 324
 325                         return sock->ssap;
 326                 }
 327         }
 328
 329         mutex_unlock(&local->sdp_lock);
 330
 331         return LLCP_SAP_MAX;
 332 }
 333
 334 u8 nfc_llcp_get_local_ssap(struct nfc_llcp_local *local)
 335 {
 336         u8 local_ssap;
 337
 338         mutex_lock(&local->sdp_lock);
 339
 340         local_ssap = find_first_zero_bit(&local->local_sap, LLCP_LOCAL_NUM_SAP);
 341         if (local_ssap == LLCP_LOCAL_NUM_SAP) {
 342                 mutex_unlock(&local->sdp_lock);
 343                 return LLCP_SAP_MAX;
 344         }
 345
 346         set_bit(local_ssap, &local->local_sap);
 347
 348         mutex_unlock(&local->sdp_lock);
 349
 350         return local_ssap + LLCP_LOCAL_SAP_OFFSET;
 351 }
 352
 353 void nfc_llcp_put_ssap(struct nfc_llcp_local *local, u8 ssap)
 354 {
 355         u8 local_ssap;
 356         unsigned long *sdp;
 357
 358         if (ssap < LLCP_WKS_NUM_SAP) {
 359                 local_ssap = ssap;
 360                 sdp = &local->local_wks;
 361         } else if (ssap < LLCP_LOCAL_NUM_SAP) {
 362                 atomic_t *client_cnt;
 363
 364                 local_ssap = ssap - LLCP_WKS_NUM_SAP;
 365                 sdp = &local->local_sdp;
 366                 client_cnt = &local->local_sdp_cnt[local_ssap];
 367
 368                 pr_debug("%d clients\n", atomic_read(client_cnt));
 369
 370                 mutex_lock(&local->sdp_lock);
 371
 372                 if (atomic_dec_and_test(client_cnt)) {
 373                         struct nfc_llcp_sock *l_sock;
 374
 375                         pr_debug("No more clients for SAP %d\n", ssap);
 376
 377                         clear_bit(local_ssap, sdp);
 378
 379                         /* Find the listening sock and set it back to UNBOUND */
 380                         l_sock = nfc_llcp_sock_get(local, ssap, LLCP_SAP_SDP);
 381                         if (l_sock) {
 382                                 l_sock->ssap = LLCP_SDP_UNBOUND;
 383                                 nfc_llcp_sock_put(l_sock);
 384                         }
 385                 }
 386
 387                 mutex_unlock(&local->sdp_lock);
 388
 389                 return;
 390         } else if (ssap < LLCP_MAX_SAP) {
 391                 local_ssap = ssap - LLCP_LOCAL_NUM_SAP;
 392                 sdp = &local->local_sap;
 393         } else {
 394                 return;
 395         }
 396
 397         mutex_lock(&local->sdp_lock);
 398
 399         clear_bit(local_ssap, sdp);
 400
 401         mutex_unlock(&local->sdp_lock);
 402 }
 403
 404 static u8 nfc_llcp_reserve_sdp_ssap(struct nfc_llcp_local *local)
 405 {
 406         u8 ssap;
 407
 408         mutex_lock(&local->sdp_lock);
 409
 410         ssap = find_first_zero_bit(&local->local_sdp, LLCP_SDP_NUM_SAP);
 411         if (ssap == LLCP_SDP_NUM_SAP) {
 412                 mutex_unlock(&local->sdp_lock);
 413
 414                 return LLCP_SAP_MAX;
 415         }
 416
 417         pr_debug("SDP ssap %d\n", LLCP_WKS_NUM_SAP + ssap);
 418
 419         set_bit(ssap, &local->local_sdp);
 420
 421         mutex_unlock(&local->sdp_lock);
 422
 423         return LLCP_WKS_NUM_SAP + ssap;
 424 }
 425
 426 static int nfc_llcp_build_gb(struct nfc_llcp_local *local)
 427 {
 428         u8 *gb_cur, *version_tlv, version, version_length;
 429         u8 *lto_tlv, lto, lto_length;
 430         u8 *wks_tlv, wks_length;
 431         u8 *miux_tlv, miux_length;
 432         __be16 miux;
 433         u8 gb_len = 0;
 434         int ret = 0;
 435
 436         version = LLCP_VERSION_11;
 437         version_tlv = nfc_llcp_build_tlv(LLCP_TLV_VERSION, &version,
 438                                          1, &version_length);
 439         gb_len += version_length;
 440
 441         /* 1500 ms */
 442         lto = 150;
 443         lto_tlv = nfc_llcp_build_tlv(LLCP_TLV_LTO, &lto, 1, &lto_length);
 444         gb_len += lto_length;
 445
 446         pr_debug("Local wks 0x%lx\n", local->local_wks);
 447         wks_tlv = nfc_llcp_build_tlv(LLCP_TLV_WKS, (u8 *)&local->local_wks, 2,
 448                                      &wks_length);
 449         gb_len += wks_length;
 450
 451         miux = cpu_to_be16(LLCP_MAX_MIUX);
 452         miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0,
 453                                       &miux_length);
 454         gb_len += miux_length;
 455
 456         gb_len += ARRAY_SIZE(llcp_magic);
 457
 458         if (gb_len > NFC_MAX_GT_LEN) {
 459                 ret = -EINVAL;
 460                 goto out;
 461         }
 462
 463         gb_cur = local->gb;
 464
 465         memcpy(gb_cur, llcp_magic, ARRAY_SIZE(llcp_magic));
 466         gb_cur += ARRAY_SIZE(llcp_magic);
 467
 468         memcpy(gb_cur, version_tlv, version_length);
 469         gb_cur += version_length;
 470
 471         memcpy(gb_cur, lto_tlv, lto_length);
 472         gb_cur += lto_length;
 473
 474         memcpy(gb_cur, wks_tlv, wks_length);
 475         gb_cur += wks_length;
 476
 477         memcpy(gb_cur, miux_tlv, miux_length);
 478         gb_cur += miux_length;
 479
 480         local->gb_len = gb_len;
 481
 482 out:
 483         kfree(version_tlv);
 484         kfree(lto_tlv);
 485         kfree(wks_tlv);
 486         kfree(miux_tlv);
 487
 488         return ret;
 489 }
 490
 491 u8 *nfc_llcp_general_bytes(struct nfc_dev *dev, size_t *general_bytes_len)
 492 {
 493         struct nfc_llcp_local *local;
 494
 495         local = nfc_llcp_find_local(dev);
 496         if (local == NULL) {
 497                 *general_bytes_len = 0;
 498                 return NULL;
 499         }
 500
 501         nfc_llcp_build_gb(local);
 502
 503         *general_bytes_len = local->gb_len;
 504
 505         return local->gb;
 506 }
 507
 508 int nfc_llcp_set_remote_gb(struct nfc_dev *dev, u8 *gb, u8 gb_len)
 509 {
 510         struct nfc_llcp_local *local = nfc_llcp_find_local(dev);
 511
 512         if (local == NULL) {
 513                 pr_err("No LLCP device\n");
 514                 return -ENODEV;
 515         }
 516
 517         memset(local->remote_gb, 0, NFC_MAX_GT_LEN);
 518         memcpy(local->remote_gb, gb, gb_len);
 519         local->remote_gb_len = gb_len;
 520
 521         if (local->remote_gb == NULL || local->remote_gb_len == 0)
 522                 return -ENODEV;
 523
 524         if (memcmp(local->remote_gb, llcp_magic, 3)) {
 525                 pr_err("MAC does not support LLCP\n");
 526                 return -EINVAL;
 527         }
 528
 529         return nfc_llcp_parse_gb_tlv(local,
 530                                      &local->remote_gb[3],
 531                                      local->remote_gb_len - 3);
 532 }
 533
 534 static u8 nfc_llcp_dsap(struct sk_buff *pdu)
 535 {
 536         return (pdu->data[0] & 0xfc) >> 2;
 537 }
 538
 539 static u8 nfc_llcp_ptype(struct sk_buff *pdu)
 540 {
 541         return ((pdu->data[0] & 0x03) << 2) | ((pdu->data[1] & 0xc0) >> 6);
 542 }
 543
 544 static u8 nfc_llcp_ssap(struct sk_buff *pdu)
 545 {
 546         return pdu->data[1] & 0x3f;
 547 }
 548
 549 static u8 nfc_llcp_ns(struct sk_buff *pdu)
 550 {
 551         return pdu->data[2] >> 4;
 552 }
 553
 554 static u8 nfc_llcp_nr(struct sk_buff *pdu)
 555 {
 556         return pdu->data[2] & 0xf;
 557 }
 558
 559 static void nfc_llcp_set_nrns(struct nfc_llcp_sock *sock, struct sk_buff *pdu)
 560 {
 561         pdu->data[2] = (sock->send_n << 4) | (sock->recv_n);
 562         sock->send_n = (sock->send_n + 1) % 16;
 563         sock->recv_ack_n = (sock->recv_n - 1) % 16;
 564 }
 565
 566 void nfc_llcp_send_to_raw_sock(struct nfc_llcp_local *local,
 567                                struct sk_buff *skb, u8 direction)
 568 {
 569         struct hlist_node *node;
 570         struct sk_buff *skb_copy = NULL, *nskb;
 571         struct sock *sk;
 572         u8 *data;
 573
 574         read_lock(&local->raw_sockets.lock);
 575
 576         sk_for_each(sk, node, &local->raw_sockets.head) {
 577                 if (sk->sk_state != LLCP_BOUND)
 578                         continue;
 579
 580                 if (skb_copy == NULL) {
 581                         skb_copy = __pskb_copy(skb, NFC_LLCP_RAW_HEADER_SIZE,
 582                                                GFP_ATOMIC);
 583
 584                         if (skb_copy == NULL)
 585                                 continue;
 586
 587                         data = skb_push(skb_copy, NFC_LLCP_RAW_HEADER_SIZE);
 588
 589                         data[0] = local->dev ? local->dev->idx : 0xFF;
 590                         data[1] = direction;
 591                 }
 592
 593                 nskb = skb_clone(skb_copy, GFP_ATOMIC);
 594                 if (!nskb)
 595                         continue;
 596
 597                 if (sock_queue_rcv_skb(sk, nskb))
 598                         kfree_skb(nskb);
 599         }
 600
 601         read_unlock(&local->raw_sockets.lock);
 602
 603         kfree_skb(skb_copy);
 604 }
 605
 606 static void nfc_llcp_tx_work(struct work_struct *work)
 607 {
 608         struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
 609                                                     tx_work);
 610         struct sk_buff *skb;
 611         struct sock *sk;
 612         struct nfc_llcp_sock *llcp_sock;
 613
 614         skb = skb_dequeue(&local->tx_queue);
 615         if (skb != NULL) {
 616                 sk = skb->sk;
 617                 llcp_sock = nfc_llcp_sock(sk);
 618
 619                 if (llcp_sock == NULL && nfc_llcp_ptype(skb) == LLCP_PDU_I) {
 620                         nfc_llcp_send_symm(local->dev);
 621                 } else {
 622                         int ret;
 623
 624                         pr_debug("Sending pending skb\n");
 625                         print_hex_dump(KERN_DEBUG, "LLCP Tx: ",
 626                                        DUMP_PREFIX_OFFSET, 16, 1,
 627                                        skb->data, skb->len, true);
 628
 629                         nfc_llcp_send_to_raw_sock(local, skb,
 630                                                   NFC_LLCP_DIRECTION_TX);
 631
 632                         ret = nfc_data_exchange(local->dev, local->target_idx,
 633                                                 skb, nfc_llcp_recv, local);
 634
 635                         if (!ret && nfc_llcp_ptype(skb) == LLCP_PDU_I) {
 636                                 skb = skb_get(skb);
 637                                 skb_queue_tail(&llcp_sock->tx_pending_queue,
 638                                                skb);
 639                         }
 640                 }
 641         } else {
 642                 nfc_llcp_send_symm(local->dev);
 643         }
 644
 645         mod_timer(&local->link_timer,
 646                   jiffies + msecs_to_jiffies(2 * local->remote_lto));
 647 }
 648
 649 static struct nfc_llcp_sock *nfc_llcp_connecting_sock_get(struct nfc_llcp_local *local,
 650                                                           u8 ssap)
 651 {
 652         struct sock *sk;
 653         struct nfc_llcp_sock *llcp_sock;
 654         struct hlist_node *node;
 655
 656         read_lock(&local->connecting_sockets.lock);
 657
 658         sk_for_each(sk, node, &local->connecting_sockets.head) {
 659                 llcp_sock = nfc_llcp_sock(sk);
 660
 661                 if (llcp_sock->ssap == ssap) {
 662                         sock_hold(&llcp_sock->sk);
 663                         goto out;
 664                 }
 665         }
 666
 667         llcp_sock = NULL;
 668
 669 out:
 670         read_unlock(&local->connecting_sockets.lock);
 671
 672         return llcp_sock;
 673 }
 674
 675 static struct nfc_llcp_sock *nfc_llcp_sock_get_sn(struct nfc_llcp_local *local,
 676                                                   u8 *sn, size_t sn_len)
 677 {
 678         struct nfc_llcp_sock *llcp_sock;
 679
 680         llcp_sock = nfc_llcp_sock_from_sn(local, sn, sn_len);
 681
 682         if (llcp_sock == NULL)
 683                 return NULL;
 684
 685         sock_hold(&llcp_sock->sk);
 686
 687         return llcp_sock;
 688 }
 689
 690 static u8 *nfc_llcp_connect_sn(struct sk_buff *skb, size_t *sn_len)
 691 {
 692         u8 *tlv = &skb->data[2], type, length;
 693         size_t tlv_array_len = skb->len - LLCP_HEADER_SIZE, offset = 0;
 694
 695         while (offset < tlv_array_len) {
 696                 type = tlv[0];
 697                 length = tlv[1];
 698
 699                 pr_debug("type 0x%x length %d\n", type, length);
 700
 701                 if (type == LLCP_TLV_SN) {
 702                         *sn_len = length;
 703                         return &tlv[2];
 704                 }
 705
 706                 offset += length + 2;
 707                 tlv += length + 2;
 708         }
 709
 710         return NULL;
 711 }
 712
 713 static void nfc_llcp_recv_connect(struct nfc_llcp_local *local,
 714                                   struct sk_buff *skb)
 715 {
 716         struct sock *new_sk, *parent;
 717         struct nfc_llcp_sock *sock, *new_sock;
 718         u8 dsap, ssap, reason;
 719
 720         dsap = nfc_llcp_dsap(skb);
 721         ssap = nfc_llcp_ssap(skb);
 722
 723         pr_debug("%d %d\n", dsap, ssap);
 724
 725         if (dsap != LLCP_SAP_SDP) {
 726                 sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
 727                 if (sock == NULL || sock->sk.sk_state != LLCP_LISTEN) {
 728                         reason = LLCP_DM_NOBOUND;
 729                         goto fail;
 730                 }
 731         } else {
 732                 u8 *sn;
 733                 size_t sn_len;
 734
 735                 sn = nfc_llcp_connect_sn(skb, &sn_len);
 736                 if (sn == NULL) {
 737                         reason = LLCP_DM_NOBOUND;
 738                         goto fail;
 739                 }
 740
 741                 pr_debug("Service name length %zu\n", sn_len);
 742
 743                 sock = nfc_llcp_sock_get_sn(local, sn, sn_len);
 744                 if (sock == NULL) {
 745                         reason = LLCP_DM_NOBOUND;
 746                         goto fail;
 747                 }
 748         }
 749
 750         lock_sock(&sock->sk);
 751
 752         parent = &sock->sk;
 753
 754         if (sk_acceptq_is_full(parent)) {
 755                 reason = LLCP_DM_REJ;
 756                 release_sock(&sock->sk);
 757                 sock_put(&sock->sk);
 758                 goto fail;
 759         }
 760
 761         if (sock->ssap == LLCP_SDP_UNBOUND) {
 762                 u8 ssap = nfc_llcp_reserve_sdp_ssap(local);
 763
 764                 pr_debug("First client, reserving %d\n", ssap);
 765
 766                 if (ssap == LLCP_SAP_MAX) {
 767                         reason = LLCP_DM_REJ;
 768                         release_sock(&sock->sk);
 769                         sock_put(&sock->sk);
 770                         goto fail;
 771                 }
 772
 773                 sock->ssap = ssap;
 774         }
 775
 776         new_sk = nfc_llcp_sock_alloc(NULL, parent->sk_type, GFP_ATOMIC);
 777         if (new_sk == NULL) {
 778                 reason = LLCP_DM_REJ;
 779                 release_sock(&sock->sk);
 780                 sock_put(&sock->sk);
 781                 goto fail;
 782         }
 783
 784         new_sock = nfc_llcp_sock(new_sk);
 785         new_sock->dev = local->dev;
 786         new_sock->local = nfc_llcp_local_get(local);
 787         new_sock->miu = local->remote_miu;
 788         new_sock->nfc_protocol = sock->nfc_protocol;
 789         new_sock->dsap = ssap;
 790         new_sock->target_idx = local->target_idx;
 791         new_sock->parent = parent;
 792         new_sock->ssap = sock->ssap;
 793         if (sock->ssap < LLCP_LOCAL_NUM_SAP && sock->ssap >= LLCP_WKS_NUM_SAP) {
 794                 atomic_t *client_count;
 795
 796                 pr_debug("reserved_ssap %d for %p\n", sock->ssap, new_sock);
 797
 798                 client_count =
 799                         &local->local_sdp_cnt[sock->ssap - LLCP_WKS_NUM_SAP];
 800
 801                 atomic_inc(client_count);
 802                 new_sock->reserved_ssap = sock->ssap;
 803         }
 804
 805         nfc_llcp_parse_connection_tlv(new_sock, &skb->data[LLCP_HEADER_SIZE],
 806                                       skb->len - LLCP_HEADER_SIZE);
 807
 808         pr_debug("new sock %p sk %p\n", new_sock, &new_sock->sk);
 809
 810         nfc_llcp_sock_link(&local->sockets, new_sk);
 811
 812         nfc_llcp_accept_enqueue(&sock->sk, new_sk);
 813
 814         nfc_get_device(local->dev->idx);
 815
 816         new_sk->sk_state = LLCP_CONNECTED;
 817
 818         /* Wake the listening processes */
 819         parent->sk_data_ready(parent, 0);
 820
 821         /* Send CC */
 822         nfc_llcp_send_cc(new_sock);
 823
 824         release_sock(&sock->sk);
 825         sock_put(&sock->sk);
 826
 827         return;
 828
 829 fail:
 830         /* Send DM */
 831         nfc_llcp_send_dm(local, dsap, ssap, reason);
 832 }
 833
 834 int nfc_llcp_queue_i_frames(struct nfc_llcp_sock *sock)
 835 {
 836         int nr_frames = 0;
 837         struct nfc_llcp_local *local = sock->local;
 838
 839         pr_debug("Remote ready %d tx queue len %d remote rw %d",
 840                  sock->remote_ready, skb_queue_len(&sock->tx_pending_queue),
 841                  sock->rw);
 842
 843         /* Try to queue some I frames for transmission */
 844         while (sock->remote_ready &&
 845                skb_queue_len(&sock->tx_pending_queue) < sock->rw) {
 846                 struct sk_buff *pdu;
 847
 848                 pdu = skb_dequeue(&sock->tx_queue);
 849                 if (pdu == NULL)
 850                         break;
 851
 852                 /* Update N(S)/N(R) */
 853                 nfc_llcp_set_nrns(sock, pdu);
 854
 855                 skb_queue_tail(&local->tx_queue, pdu);
 856                 nr_frames++;
 857         }
 858
 859         return nr_frames;
 860 }
 861
 862 static void nfc_llcp_recv_hdlc(struct nfc_llcp_local *local,
 863                                struct sk_buff *skb)
 864 {
 865         struct nfc_llcp_sock *llcp_sock;
 866         struct sock *sk;
 867         u8 dsap, ssap, ptype, ns, nr;
 868
 869         ptype = nfc_llcp_ptype(skb);
 870         dsap = nfc_llcp_dsap(skb);
 871         ssap = nfc_llcp_ssap(skb);
 872         ns = nfc_llcp_ns(skb);
 873         nr = nfc_llcp_nr(skb);
 874
 875         pr_debug("%d %d R %d S %d\n", dsap, ssap, nr, ns);
 876
 877         llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
 878         if (llcp_sock == NULL) {
 879                 nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
 880                 return;
 881         }
 882
 883         sk = &llcp_sock->sk;
 884         lock_sock(sk);
 885         if (sk->sk_state == LLCP_CLOSED) {
 886                 release_sock(sk);
 887                 nfc_llcp_sock_put(llcp_sock);
 888         }
 889
 890         /* Pass the payload upstream */
 891         if (ptype == LLCP_PDU_I) {
 892                 pr_debug("I frame, queueing on %p\n", &llcp_sock->sk);
 893
 894                 if (ns == llcp_sock->recv_n)
 895                         llcp_sock->recv_n = (llcp_sock->recv_n + 1) % 16;
 896                 else
 897                         pr_err("Received out of sequence I PDU\n");
 898
 899                 skb_pull(skb, LLCP_HEADER_SIZE + LLCP_SEQUENCE_SIZE);
 900                 if (sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
 901                         pr_err("receive queue is full\n");
 902                         skb_queue_head(&llcp_sock->tx_backlog_queue, skb);
 903                 }
 904         }
 905
 906         /* Remove skbs from the pending queue */
 907         if (llcp_sock->send_ack_n != nr) {
 908                 struct sk_buff *s, *tmp;
 909
 910                 llcp_sock->send_ack_n = nr;
 911
 912                 /* Remove and free all skbs until ns == nr */
 913                 skb_queue_walk_safe(&llcp_sock->tx_pending_queue, s, tmp) {
 914                         skb_unlink(s, &llcp_sock->tx_pending_queue);
 915                         kfree_skb(s);
 916
 917                         if (nfc_llcp_ns(s) == nr)
 918                                 break;
 919                 }
 920
 921                 /* Re-queue the remaining skbs for transmission */
 922                 skb_queue_reverse_walk_safe(&llcp_sock->tx_pending_queue,
 923                                             s, tmp) {
 924                         skb_unlink(s, &llcp_sock->tx_pending_queue);
 925                         skb_queue_head(&local->tx_queue, s);
 926                 }
 927         }
 928
 929         if (ptype == LLCP_PDU_RR)
 930                 llcp_sock->remote_ready = true;
 931         else if (ptype == LLCP_PDU_RNR)
 932                 llcp_sock->remote_ready = false;
 933
 934         if (nfc_llcp_queue_i_frames(llcp_sock) == 0 && ptype == LLCP_PDU_I)
 935                 nfc_llcp_send_rr(llcp_sock);
 936
 937         release_sock(sk);
 938         nfc_llcp_sock_put(llcp_sock);
 939 }
 940
 941 static void nfc_llcp_recv_disc(struct nfc_llcp_local *local,
 942                                struct sk_buff *skb)
 943 {
 944         struct nfc_llcp_sock *llcp_sock;
 945         struct sock *sk;
 946         u8 dsap, ssap;
 947
 948         dsap = nfc_llcp_dsap(skb);
 949         ssap = nfc_llcp_ssap(skb);
 950
 951         llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
 952         if (llcp_sock == NULL) {
 953                 nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
 954                 return;
 955         }
 956
 957         sk = &llcp_sock->sk;
 958         lock_sock(sk);
 959         if (sk->sk_state == LLCP_CLOSED) {
 960                 release_sock(sk);
 961                 nfc_llcp_sock_put(llcp_sock);
 962         }
 963
 964         if (sk->sk_state == LLCP_CONNECTED) {
 965                 nfc_put_device(local->dev);
 966                 sk->sk_state = LLCP_CLOSED;
 967                 sk->sk_state_change(sk);
 968         }
 969
 970         nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_DISC);
 971
 972         release_sock(sk);
 973         nfc_llcp_sock_put(llcp_sock);
 974 }
 975
 976 static void nfc_llcp_recv_cc(struct nfc_llcp_local *local, struct sk_buff *skb)
 977 {
 978         struct nfc_llcp_sock *llcp_sock;
 979         struct sock *sk;
 980         u8 dsap, ssap;
 981
 982         dsap = nfc_llcp_dsap(skb);
 983         ssap = nfc_llcp_ssap(skb);
 984
 985         llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
 986         if (llcp_sock == NULL) {
 987                 pr_err("Invalid CC\n");
 988                 nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
 989
 990                 return;
 991         }
 992
 993         sk = &llcp_sock->sk;
 994
 995         /* Unlink from connecting and link to the client array */
 996         nfc_llcp_sock_unlink(&local->connecting_sockets, sk);
 997         nfc_llcp_sock_link(&local->sockets, sk);
 998         llcp_sock->dsap = ssap;
 999
1000         nfc_llcp_parse_connection_tlv(llcp_sock, &skb->data[LLCP_HEADER_SIZE],
1001                                       skb->len - LLCP_HEADER_SIZE);
1002
1003         sk->sk_state = LLCP_CONNECTED;
1004         sk->sk_state_change(sk);
1005
1006         nfc_llcp_sock_put(llcp_sock);
1007 }
1008
1009 static void nfc_llcp_recv_dm(struct nfc_llcp_local *local, struct sk_buff *skb)
1010 {
1011         struct nfc_llcp_sock *llcp_sock;
1012         struct sock *sk;
1013         u8 dsap, ssap, reason;
1014
1015         dsap = nfc_llcp_dsap(skb);
1016         ssap = nfc_llcp_ssap(skb);
1017         reason = skb->data[2];
1018
1019         pr_debug("%d %d reason %d\n", ssap, dsap, reason);
1020
1021         switch (reason) {
1022         case LLCP_DM_NOBOUND:
1023         case LLCP_DM_REJ:
1024                 llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
1025                 break;
1026
1027         default:
1028                 llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1029                 break;
1030         }
1031
1032         if (llcp_sock == NULL) {
1033                 pr_err("Invalid DM\n");
1034                 return;
1035         }
1036
1037         sk = &llcp_sock->sk;
1038
1039         sk->sk_err = ENXIO;
1040         sk->sk_state = LLCP_CLOSED;
1041         sk->sk_state_change(sk);
1042
1043         nfc_llcp_sock_put(llcp_sock);
1044 }
1045
1046 static void nfc_llcp_recv_snl(struct nfc_llcp_local *local,
1047                               struct sk_buff *skb)
1048 {
1049         struct nfc_llcp_sock *llcp_sock;
1050         u8 dsap, ssap, *tlv, type, length, tid, sap;
1051         u16 tlv_len, offset;
1052         char *service_name;
1053         size_t service_name_len;
1054
1055         dsap = nfc_llcp_dsap(skb);
1056         ssap = nfc_llcp_ssap(skb);
1057
1058         pr_debug("%d %d\n", dsap, ssap);
1059
1060         if (dsap != LLCP_SAP_SDP || ssap != LLCP_SAP_SDP) {
1061                 pr_err("Wrong SNL SAP\n");
1062                 return;
1063         }
1064
1065         tlv = &skb->data[LLCP_HEADER_SIZE];
1066         tlv_len = skb->len - LLCP_HEADER_SIZE;
1067         offset = 0;
1068
1069         while(offset < tlv_len) {
1070                 type = tlv[0];
1071                 length = tlv[1];
1072
1073                 switch (type) {
1074                 case LLCP_TLV_SDREQ:
1075                         tid = tlv[2];
1076                         service_name = (char *) &tlv[3];
1077                         service_name_len = length - 1;
1078
1079                         pr_debug("Looking for %.16s\n", service_name);
1080
1081                         if (service_name_len == strlen("urn:nfc:sn:sdp") &&
1082                             !strncmp(service_name, "urn:nfc:sn:sdp",
1083                                      service_name_len)) {
1084                                 sap = 1;
1085                                 goto send_snl;
1086                         }
1087
1088                         llcp_sock = nfc_llcp_sock_from_sn(local, service_name,
1089                                                           service_name_len);
1090                         if (!llcp_sock) {
1091                                 sap = 0;
1092                                 goto send_snl;
1093                         }
1094
1095                         /*
1096                          * We found a socket but its ssap has not been reserved
1097                          * yet. We need to assign it for good and send a reply.
1098                          * The ssap will be freed when the socket is closed.
1099                          */
1100                         if (llcp_sock->ssap == LLCP_SDP_UNBOUND) {
1101                                 atomic_t *client_count;
1102
1103                                 sap = nfc_llcp_reserve_sdp_ssap(local);
1104
1105                                 pr_debug("Reserving %d\n", sap);
1106
1107                                 if (sap == LLCP_SAP_MAX) {
1108                                         sap = 0;
1109                                         goto send_snl;
1110                                 }
1111
1112                                 client_count =
1113                                         &local->local_sdp_cnt[sap -
1114                                                               LLCP_WKS_NUM_SAP];
1115
1116                                 atomic_inc(client_count);
1117
1118                                 llcp_sock->ssap = sap;
1119                                 llcp_sock->reserved_ssap = sap;
1120                         } else {
1121                                 sap = llcp_sock->ssap;
1122                         }
1123
1124                         pr_debug("%p %d\n", llcp_sock, sap);
1125
1126                 send_snl:
1127                         nfc_llcp_send_snl(local, tid, sap);
1128                         break;
1129
1130                 default:
1131                         pr_err("Invalid SNL tlv value 0x%x\n", type);
1132                         break;
1133                 }
1134
1135                 offset += length + 2;
1136                 tlv += length + 2;
1137         }
1138 }
1139
1140 static void nfc_llcp_rx_work(struct work_struct *work)
1141 {
1142         struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
1143                                                     rx_work);
1144         u8 dsap, ssap, ptype;
1145         struct sk_buff *skb;
1146
1147         skb = local->rx_pending;
1148         if (skb == NULL) {
1149                 pr_debug("No pending SKB\n");
1150                 return;
1151         }
1152
1153         ptype = nfc_llcp_ptype(skb);
1154         dsap = nfc_llcp_dsap(skb);
1155         ssap = nfc_llcp_ssap(skb);
1156
1157         pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap);
1158
1159         if (ptype != LLCP_PDU_SYMM)
1160                 print_hex_dump(KERN_DEBUG, "LLCP Rx: ", DUMP_PREFIX_OFFSET,
1161                                16, 1, skb->data, skb->len, true);
1162
1163         nfc_llcp_send_to_raw_sock(local, skb, NFC_LLCP_DIRECTION_RX);
1164
1165         switch (ptype) {
1166         case LLCP_PDU_SYMM:
1167                 pr_debug("SYMM\n");
1168                 break;
1169
1170         case LLCP_PDU_CONNECT:
1171                 pr_debug("CONNECT\n");
1172                 nfc_llcp_recv_connect(local, skb);
1173                 break;
1174
1175         case LLCP_PDU_DISC:
1176                 pr_debug("DISC\n");
1177                 nfc_llcp_recv_disc(local, skb);
1178                 break;
1179
1180         case LLCP_PDU_CC:
1181                 pr_debug("CC\n");
1182                 nfc_llcp_recv_cc(local, skb);
1183                 break;
1184
1185         case LLCP_PDU_DM:
1186                 pr_debug("DM\n");
1187                 nfc_llcp_recv_dm(local, skb);
1188                 break;
1189
1190         case LLCP_PDU_SNL:
1191                 pr_debug("SNL\n");
1192                 nfc_llcp_recv_snl(local, skb);
1193                 break;
1194
1195         case LLCP_PDU_I:
1196         case LLCP_PDU_RR:
1197         case LLCP_PDU_RNR:
1198                 pr_debug("I frame\n");
1199                 nfc_llcp_recv_hdlc(local, skb);
1200                 break;
1201
1202         }
1203
1204         schedule_work(&local->tx_work);
1205         kfree_skb(local->rx_pending);
1206         local->rx_pending = NULL;
1207 }
1208
1209 void nfc_llcp_recv(void *data, struct sk_buff *skb, int err)
1210 {
1211         struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
1212
1213         pr_debug("Received an LLCP PDU\n");
1214         if (err < 0) {
1215                 pr_err("err %d\n", err);
1216                 return;
1217         }
1218
1219         local->rx_pending = skb_get(skb);
1220         del_timer(&local->link_timer);
1221         schedule_work(&local->rx_work);
1222 }
1223
1224 int nfc_llcp_data_received(struct nfc_dev *dev, struct sk_buff *skb)
1225 {
1226         struct nfc_llcp_local *local;
1227
1228         local = nfc_llcp_find_local(dev);
1229         if (local == NULL)
1230                 return -ENODEV;
1231
1232         local->rx_pending = skb_get(skb);
1233         del_timer(&local->link_timer);
1234         schedule_work(&local->rx_work);
1235
1236         return 0;
1237 }
1238
1239 void nfc_llcp_mac_is_down(struct nfc_dev *dev)
1240 {
1241         struct nfc_llcp_local *local;
1242
1243         local = nfc_llcp_find_local(dev);
1244         if (local == NULL)
1245                 return;
1246
1247         /* Close and purge all existing sockets */
1248         nfc_llcp_socket_release(local, true);
1249 }
1250
1251 void nfc_llcp_mac_is_up(struct nfc_dev *dev, u32 target_idx,
1252                         u8 comm_mode, u8 rf_mode)
1253 {
1254         struct nfc_llcp_local *local;
1255
1256         pr_debug("rf mode %d\n", rf_mode);
1257
1258         local = nfc_llcp_find_local(dev);
1259         if (local == NULL)
1260                 return;
1261
1262         local->target_idx = target_idx;
1263         local->comm_mode = comm_mode;
1264         local->rf_mode = rf_mode;
1265
1266         if (rf_mode == NFC_RF_INITIATOR) {
1267                 pr_debug("Queueing Tx work\n");
1268
1269                 schedule_work(&local->tx_work);
1270         } else {
1271                 mod_timer(&local->link_timer,
1272                           jiffies + msecs_to_jiffies(local->remote_lto));
1273         }
1274 }
1275
1276 int nfc_llcp_register_device(struct nfc_dev *ndev)
1277 {
1278         struct nfc_llcp_local *local;
1279
1280         local = kzalloc(sizeof(struct nfc_llcp_local), GFP_KERNEL);
1281         if (local == NULL)
1282                 return -ENOMEM;
1283
1284         local->dev = ndev;
1285         INIT_LIST_HEAD(&local->list);
1286         kref_init(&local->ref);
1287         mutex_init(&local->sdp_lock);
1288         init_timer(&local->link_timer);
1289         local->link_timer.data = (unsigned long) local;
1290         local->link_timer.function = nfc_llcp_symm_timer;
1291
1292         skb_queue_head_init(&local->tx_queue);
1293         INIT_WORK(&local->tx_work, nfc_llcp_tx_work);
1294
1295         local->rx_pending = NULL;
1296         INIT_WORK(&local->rx_work, nfc_llcp_rx_work);
1297
1298         INIT_WORK(&local->timeout_work, nfc_llcp_timeout_work);
1299
1300         rwlock_init(&local->sockets.lock);
1301         rwlock_init(&local->connecting_sockets.lock);
1302         rwlock_init(&local->raw_sockets.lock);
1303
1304         nfc_llcp_build_gb(local);
1305
1306         local->remote_miu = LLCP_DEFAULT_MIU;
1307         local->remote_lto = LLCP_DEFAULT_LTO;
1308
1309         list_add(&llcp_devices, &local->list);
1310
1311         return 0;
1312 }
1313
1314 void nfc_llcp_unregister_device(struct nfc_dev *dev)
1315 {
1316         struct nfc_llcp_local *local = nfc_llcp_find_local(dev);
1317
1318         if (local == NULL) {
1319                 pr_debug("No such device\n");
1320                 return;
1321         }
1322
1323         nfc_llcp_local_put(local);
1324 }
1325
1326 int __init nfc_llcp_init(void)
1327 {
1328         INIT_LIST_HEAD(&llcp_devices);
1329
1330         return nfc_llcp_sock_init();
1331 }
1332
1333 void nfc_llcp_exit(void)
1334 {
1335         nfc_llcp_sock_exit();
1336 }