net/nfc/llcp_commands.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, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #define pr_fmt(fmt) "llcp: %s: " fmt, __func__
  19
  20 #include <linux/init.h>
  21 #include <linux/kernel.h>
  22 #include <linux/module.h>
  23 #include <linux/nfc.h>
  24
  25 #include <net/nfc/nfc.h>
  26
  27 #include "nfc.h"
  28 #include "llcp.h"
  29
  30 static u8 llcp_tlv_length[LLCP_TLV_MAX] = {
  31         0,
  32         1, /* VERSION */
  33         2, /* MIUX */
  34         2, /* WKS */
  35         1, /* LTO */
  36         1, /* RW */
  37         0, /* SN */
  38         1, /* OPT */
  39         0, /* SDREQ */
  40         2, /* SDRES */
  41
  42 };
  43
  44 static u8 llcp_tlv8(u8 *tlv, u8 type)
  45 {
  46         if (tlv[0] != type || tlv[1] != llcp_tlv_length[tlv[0]])
  47                 return 0;
  48
  49         return tlv[2];
  50 }
  51
  52 static u16 llcp_tlv16(u8 *tlv, u8 type)
  53 {
  54         if (tlv[0] != type || tlv[1] != llcp_tlv_length[tlv[0]])
  55                 return 0;
  56
  57         return be16_to_cpu(*((__be16 *)(tlv + 2)));
  58 }
  59
  60
  61 static u8 llcp_tlv_version(u8 *tlv)
  62 {
  63         return llcp_tlv8(tlv, LLCP_TLV_VERSION);
  64 }
  65
  66 static u16 llcp_tlv_miux(u8 *tlv)
  67 {
  68         return llcp_tlv16(tlv, LLCP_TLV_MIUX) & 0x7ff;
  69 }
  70
  71 static u16 llcp_tlv_wks(u8 *tlv)
  72 {
  73         return llcp_tlv16(tlv, LLCP_TLV_WKS);
  74 }
  75
  76 static u16 llcp_tlv_lto(u8 *tlv)
  77 {
  78         return llcp_tlv8(tlv, LLCP_TLV_LTO);
  79 }
  80
  81 static u8 llcp_tlv_opt(u8 *tlv)
  82 {
  83         return llcp_tlv8(tlv, LLCP_TLV_OPT);
  84 }
  85
  86 static u8 llcp_tlv_rw(u8 *tlv)
  87 {
  88         return llcp_tlv8(tlv, LLCP_TLV_RW) & 0xf;
  89 }
  90
  91 u8 *nfc_llcp_build_tlv(u8 type, u8 *value, u8 value_length, u8 *tlv_length)
  92 {
  93         u8 *tlv, length;
  94
  95         pr_debug("type %d\n", type);
  96
  97         if (type >= LLCP_TLV_MAX)
  98                 return NULL;
  99
 100         length = llcp_tlv_length[type];
 101         if (length == 0 && value_length == 0)
 102                 return NULL;
 103         else if (length == 0)
 104                 length = value_length;
 105
 106         *tlv_length = 2 + length;
 107         tlv = kzalloc(2 + length, GFP_KERNEL);
 108         if (tlv == NULL)
 109                 return tlv;
 110
 111         tlv[0] = type;
 112         tlv[1] = length;
 113         memcpy(tlv + 2, value, length);
 114
 115         return tlv;
 116 }
 117
 118 struct nfc_llcp_sdp_tlv *nfc_llcp_build_sdres_tlv(u8 tid, u8 sap)
 119 {
 120         struct nfc_llcp_sdp_tlv *sdres;
 121         u8 value[2];
 122
 123         sdres = kzalloc(sizeof(struct nfc_llcp_sdp_tlv), GFP_KERNEL);
 124         if (sdres == NULL)
 125                 return NULL;
 126
 127         value[0] = tid;
 128         value[1] = sap;
 129
 130         sdres->tlv = nfc_llcp_build_tlv(LLCP_TLV_SDRES, value, 2,
 131                                         &sdres->tlv_len);
 132         if (sdres->tlv == NULL) {
 133                 kfree(sdres);
 134                 return NULL;
 135         }
 136
 137         sdres->tid = tid;
 138         sdres->sap = sap;
 139
 140         INIT_HLIST_NODE(&sdres->node);
 141
 142         return sdres;
 143 }
 144
 145 struct nfc_llcp_sdp_tlv *nfc_llcp_build_sdreq_tlv(u8 tid, char *uri,
 146                                                   size_t uri_len)
 147 {
 148         struct nfc_llcp_sdp_tlv *sdreq;
 149
 150         pr_debug("uri: %s, len: %zu\n", uri, uri_len);
 151
 152         sdreq = kzalloc(sizeof(struct nfc_llcp_sdp_tlv), GFP_KERNEL);
 153         if (sdreq == NULL)
 154                 return NULL;
 155
 156         sdreq->tlv_len = uri_len + 3;
 157
 158         if (uri[uri_len - 1] == 0)
 159                 sdreq->tlv_len--;
 160
 161         sdreq->tlv = kzalloc(sdreq->tlv_len + 1, GFP_KERNEL);
 162         if (sdreq->tlv == NULL) {
 163                 kfree(sdreq);
 164                 return NULL;
 165         }
 166
 167         sdreq->tlv[0] = LLCP_TLV_SDREQ;
 168         sdreq->tlv[1] = sdreq->tlv_len - 2;
 169         sdreq->tlv[2] = tid;
 170
 171         sdreq->tid = tid;
 172         sdreq->uri = sdreq->tlv + 3;
 173         memcpy(sdreq->uri, uri, uri_len);
 174
 175         sdreq->time = jiffies;
 176
 177         INIT_HLIST_NODE(&sdreq->node);
 178
 179         return sdreq;
 180 }
 181
 182 void nfc_llcp_free_sdp_tlv(struct nfc_llcp_sdp_tlv *sdp)
 183 {
 184         kfree(sdp->tlv);
 185         kfree(sdp);
 186 }
 187
 188 void nfc_llcp_free_sdp_tlv_list(struct hlist_head *head)
 189 {
 190         struct nfc_llcp_sdp_tlv *sdp;
 191         struct hlist_node *n;
 192
 193         hlist_for_each_entry_safe(sdp, n, head, node) {
 194                 hlist_del(&sdp->node);
 195
 196                 nfc_llcp_free_sdp_tlv(sdp);
 197         }
 198 }
 199
 200 int nfc_llcp_parse_gb_tlv(struct nfc_llcp_local *local,
 201                           u8 *tlv_array, u16 tlv_array_len)
 202 {
 203         u8 *tlv = tlv_array, type, length, offset = 0;
 204
 205         pr_debug("TLV array length %d\n", tlv_array_len);
 206
 207         if (local == NULL)
 208                 return -ENODEV;
 209
 210         while (offset < tlv_array_len) {
 211                 type = tlv[0];
 212                 length = tlv[1];
 213
 214                 pr_debug("type 0x%x length %d\n", type, length);
 215
 216                 switch (type) {
 217                 case LLCP_TLV_VERSION:
 218                         local->remote_version = llcp_tlv_version(tlv);
 219                         break;
 220                 case LLCP_TLV_MIUX:
 221                         local->remote_miu = llcp_tlv_miux(tlv) + 128;
 222                         break;
 223                 case LLCP_TLV_WKS:
 224                         local->remote_wks = llcp_tlv_wks(tlv);
 225                         break;
 226                 case LLCP_TLV_LTO:
 227                         local->remote_lto = llcp_tlv_lto(tlv) * 10;
 228                         break;
 229                 case LLCP_TLV_OPT:
 230                         local->remote_opt = llcp_tlv_opt(tlv);
 231                         break;
 232                 default:
 233                         pr_err("Invalid gt tlv value 0x%x\n", type);
 234                         break;
 235                 }
 236
 237                 offset += length + 2;
 238                 tlv += length + 2;
 239         }
 240
 241         pr_debug("version 0x%x miu %d lto %d opt 0x%x wks 0x%x\n",
 242                  local->remote_version, local->remote_miu,
 243                  local->remote_lto, local->remote_opt,
 244                  local->remote_wks);
 245
 246         return 0;
 247 }
 248
 249 int nfc_llcp_parse_connection_tlv(struct nfc_llcp_sock *sock,
 250                                   u8 *tlv_array, u16 tlv_array_len)
 251 {
 252         u8 *tlv = tlv_array, type, length, offset = 0;
 253
 254         pr_debug("TLV array length %d\n", tlv_array_len);
 255
 256         if (sock == NULL)
 257                 return -ENOTCONN;
 258
 259         while (offset < tlv_array_len) {
 260                 type = tlv[0];
 261                 length = tlv[1];
 262
 263                 pr_debug("type 0x%x length %d\n", type, length);
 264
 265                 switch (type) {
 266                 case LLCP_TLV_MIUX:
 267                         sock->remote_miu = llcp_tlv_miux(tlv) + 128;
 268                         break;
 269                 case LLCP_TLV_RW:
 270                         sock->remote_rw = llcp_tlv_rw(tlv);
 271                         break;
 272                 case LLCP_TLV_SN:
 273                         break;
 274                 default:
 275                         pr_err("Invalid gt tlv value 0x%x\n", type);
 276                         break;
 277                 }
 278
 279                 offset += length + 2;
 280                 tlv += length + 2;
 281         }
 282
 283         pr_debug("sock %p rw %d miu %d\n", sock,
 284                  sock->remote_rw, sock->remote_miu);
 285
 286         return 0;
 287 }
 288
 289 static struct sk_buff *llcp_add_header(struct sk_buff *pdu,
 290                                        u8 dsap, u8 ssap, u8 ptype)
 291 {
 292         u8 header[2];
 293
 294         pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap);
 295
 296         header[0] = (u8)((dsap << 2) | (ptype >> 2));
 297         header[1] = (u8)((ptype << 6) | ssap);
 298
 299         pr_debug("header 0x%x 0x%x\n", header[0], header[1]);
 300
 301         memcpy(skb_put(pdu, LLCP_HEADER_SIZE), header, LLCP_HEADER_SIZE);
 302
 303         return pdu;
 304 }
 305
 306 static struct sk_buff *llcp_add_tlv(struct sk_buff *pdu, u8 *tlv,
 307                                     u8 tlv_length)
 308 {
 309         /* XXX Add an skb length check */
 310
 311         if (tlv == NULL)
 312                 return NULL;
 313
 314         memcpy(skb_put(pdu, tlv_length), tlv, tlv_length);
 315
 316         return pdu;
 317 }
 318
 319 static struct sk_buff *llcp_allocate_pdu(struct nfc_llcp_sock *sock,
 320                                          u8 cmd, u16 size)
 321 {
 322         struct sk_buff *skb;
 323         int err;
 324
 325         if (sock->ssap == 0)
 326                 return NULL;
 327
 328         skb = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT,
 329                                  size + LLCP_HEADER_SIZE, &err);
 330         if (skb == NULL) {
 331                 pr_err("Could not allocate PDU\n");
 332                 return NULL;
 333         }
 334
 335         skb = llcp_add_header(skb, sock->dsap, sock->ssap, cmd);
 336
 337         return skb;
 338 }
 339
 340 int nfc_llcp_send_disconnect(struct nfc_llcp_sock *sock)
 341 {
 342         struct sk_buff *skb;
 343         struct nfc_dev *dev;
 344         struct nfc_llcp_local *local;
 345
 346         pr_debug("Sending DISC\n");
 347
 348         local = sock->local;
 349         if (local == NULL)
 350                 return -ENODEV;
 351
 352         dev = sock->dev;
 353         if (dev == NULL)
 354                 return -ENODEV;
 355
 356         skb = llcp_allocate_pdu(sock, LLCP_PDU_DISC, 0);
 357         if (skb == NULL)
 358                 return -ENOMEM;
 359
 360         skb_queue_tail(&local->tx_queue, skb);
 361
 362         return 0;
 363 }
 364
 365 int nfc_llcp_send_symm(struct nfc_dev *dev)
 366 {
 367         struct sk_buff *skb;
 368         struct nfc_llcp_local *local;
 369         u16 size = 0;
 370
 371         pr_debug("Sending SYMM\n");
 372
 373         local = nfc_llcp_find_local(dev);
 374         if (local == NULL)
 375                 return -ENODEV;
 376
 377         size += LLCP_HEADER_SIZE;
 378         size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
 379
 380         skb = alloc_skb(size, GFP_KERNEL);
 381         if (skb == NULL)
 382                 return -ENOMEM;
 383
 384         skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
 385
 386         skb = llcp_add_header(skb, 0, 0, LLCP_PDU_SYMM);
 387
 388         __net_timestamp(skb);
 389
 390         nfc_llcp_send_to_raw_sock(local, skb, NFC_DIRECTION_TX);
 391
 392         return nfc_data_exchange(dev, local->target_idx, skb,
 393                                  nfc_llcp_recv, local);
 394 }
 395
 396 int nfc_llcp_send_connect(struct nfc_llcp_sock *sock)
 397 {
 398         struct nfc_llcp_local *local;
 399         struct sk_buff *skb;
 400         u8 *service_name_tlv = NULL, service_name_tlv_length;
 401         u8 *miux_tlv = NULL, miux_tlv_length;
 402         u8 *rw_tlv = NULL, rw_tlv_length, rw;
 403         int err;
 404         u16 size = 0;
 405         __be16 miux;
 406
 407         pr_debug("Sending CONNECT\n");
 408
 409         local = sock->local;
 410         if (local == NULL)
 411                 return -ENODEV;
 412
 413         if (sock->service_name != NULL) {
 414                 service_name_tlv = nfc_llcp_build_tlv(LLCP_TLV_SN,
 415                                                       sock->service_name,
 416                                                       sock->service_name_len,
 417                                                       &service_name_tlv_length);
 418                 size += service_name_tlv_length;
 419         }
 420
 421         /* If the socket parameters are not set, use the local ones */
 422         miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ?
 423                 local->miux : sock->miux;
 424         rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw;
 425
 426         miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0,
 427                                       &miux_tlv_length);
 428         size += miux_tlv_length;
 429
 430         rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length);
 431         size += rw_tlv_length;
 432
 433         pr_debug("SKB size %d SN length %zu\n", size, sock->service_name_len);
 434
 435         skb = llcp_allocate_pdu(sock, LLCP_PDU_CONNECT, size);
 436         if (skb == NULL) {
 437                 err = -ENOMEM;
 438                 goto error_tlv;
 439         }
 440
 441         if (service_name_tlv != NULL)
 442                 skb = llcp_add_tlv(skb, service_name_tlv,
 443                                    service_name_tlv_length);
 444
 445         skb = llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
 446         skb = llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
 447
 448         skb_queue_tail(&local->tx_queue, skb);
 449
 450         return 0;
 451
 452 error_tlv:
 453         pr_err("error %d\n", err);
 454
 455         kfree(service_name_tlv);
 456         kfree(miux_tlv);
 457         kfree(rw_tlv);
 458
 459         return err;
 460 }
 461
 462 int nfc_llcp_send_cc(struct nfc_llcp_sock *sock)
 463 {
 464         struct nfc_llcp_local *local;
 465         struct sk_buff *skb;
 466         u8 *miux_tlv = NULL, miux_tlv_length;
 467         u8 *rw_tlv = NULL, rw_tlv_length, rw;
 468         int err;
 469         u16 size = 0;
 470         __be16 miux;
 471
 472         pr_debug("Sending CC\n");
 473
 474         local = sock->local;
 475         if (local == NULL)
 476                 return -ENODEV;
 477
 478         /* If the socket parameters are not set, use the local ones */
 479         miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ?
 480                 local->miux : sock->miux;
 481         rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw;
 482
 483         miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0,
 484                                       &miux_tlv_length);
 485         size += miux_tlv_length;
 486
 487         rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length);
 488         size += rw_tlv_length;
 489
 490         skb = llcp_allocate_pdu(sock, LLCP_PDU_CC, size);
 491         if (skb == NULL) {
 492                 err = -ENOMEM;
 493                 goto error_tlv;
 494         }
 495
 496         skb = llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
 497         skb = llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
 498
 499         skb_queue_tail(&local->tx_queue, skb);
 500
 501         return 0;
 502
 503 error_tlv:
 504         pr_err("error %d\n", err);
 505
 506         kfree(miux_tlv);
 507         kfree(rw_tlv);
 508
 509         return err;
 510 }
 511
 512 static struct sk_buff *nfc_llcp_allocate_snl(struct nfc_llcp_local *local,
 513                                              size_t tlv_length)
 514 {
 515         struct sk_buff *skb;
 516         struct nfc_dev *dev;
 517         u16 size = 0;
 518
 519         if (local == NULL)
 520                 return ERR_PTR(-ENODEV);
 521
 522         dev = local->dev;
 523         if (dev == NULL)
 524                 return ERR_PTR(-ENODEV);
 525
 526         size += LLCP_HEADER_SIZE;
 527         size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
 528         size += tlv_length;
 529
 530         skb = alloc_skb(size, GFP_KERNEL);
 531         if (skb == NULL)
 532                 return ERR_PTR(-ENOMEM);
 533
 534         skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
 535
 536         skb = llcp_add_header(skb, LLCP_SAP_SDP, LLCP_SAP_SDP, LLCP_PDU_SNL);
 537
 538         return skb;
 539 }
 540
 541 int nfc_llcp_send_snl_sdres(struct nfc_llcp_local *local,
 542                             struct hlist_head *tlv_list, size_t tlvs_len)
 543 {
 544         struct nfc_llcp_sdp_tlv *sdp;
 545         struct hlist_node *n;
 546         struct sk_buff *skb;
 547
 548         skb = nfc_llcp_allocate_snl(local, tlvs_len);
 549         if (IS_ERR(skb))
 550                 return PTR_ERR(skb);
 551
 552         hlist_for_each_entry_safe(sdp, n, tlv_list, node) {
 553                 memcpy(skb_put(skb, sdp->tlv_len), sdp->tlv, sdp->tlv_len);
 554
 555                 hlist_del(&sdp->node);
 556
 557                 nfc_llcp_free_sdp_tlv(sdp);
 558         }
 559
 560         skb_queue_tail(&local->tx_queue, skb);
 561
 562         return 0;
 563 }
 564
 565 int nfc_llcp_send_snl_sdreq(struct nfc_llcp_local *local,
 566                             struct hlist_head *tlv_list, size_t tlvs_len)
 567 {
 568         struct nfc_llcp_sdp_tlv *sdreq;
 569         struct hlist_node *n;
 570         struct sk_buff *skb;
 571
 572         skb = nfc_llcp_allocate_snl(local, tlvs_len);
 573         if (IS_ERR(skb))
 574                 return PTR_ERR(skb);
 575
 576         mutex_lock(&local->sdreq_lock);
 577
 578         if (hlist_empty(&local->pending_sdreqs))
 579                 mod_timer(&local->sdreq_timer,
 580                           jiffies + msecs_to_jiffies(3 * local->remote_lto));
 581
 582         hlist_for_each_entry_safe(sdreq, n, tlv_list, node) {
 583                 pr_debug("tid %d for %s\n", sdreq->tid, sdreq->uri);
 584
 585                 memcpy(skb_put(skb, sdreq->tlv_len), sdreq->tlv,
 586                        sdreq->tlv_len);
 587
 588                 hlist_del(&sdreq->node);
 589
 590                 hlist_add_head(&sdreq->node, &local->pending_sdreqs);
 591         }
 592
 593         mutex_unlock(&local->sdreq_lock);
 594
 595         skb_queue_tail(&local->tx_queue, skb);
 596
 597         return 0;
 598 }
 599
 600 int nfc_llcp_send_dm(struct nfc_llcp_local *local, u8 ssap, u8 dsap, u8 reason)
 601 {
 602         struct sk_buff *skb;
 603         struct nfc_dev *dev;
 604         u16 size = 1; /* Reason code */
 605
 606         pr_debug("Sending DM reason 0x%x\n", reason);
 607
 608         if (local == NULL)
 609                 return -ENODEV;
 610
 611         dev = local->dev;
 612         if (dev == NULL)
 613                 return -ENODEV;
 614
 615         size += LLCP_HEADER_SIZE;
 616         size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
 617
 618         skb = alloc_skb(size, GFP_KERNEL);
 619         if (skb == NULL)
 620                 return -ENOMEM;
 621
 622         skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
 623
 624         skb = llcp_add_header(skb, dsap, ssap, LLCP_PDU_DM);
 625
 626         memcpy(skb_put(skb, 1), &reason, 1);
 627
 628         skb_queue_head(&local->tx_queue, skb);
 629
 630         return 0;
 631 }
 632
 633 int nfc_llcp_send_i_frame(struct nfc_llcp_sock *sock,
 634                           struct msghdr *msg, size_t len)
 635 {
 636         struct sk_buff *pdu;
 637         struct sock *sk = &sock->sk;
 638         struct nfc_llcp_local *local;
 639         size_t frag_len = 0, remaining_len;
 640         u8 *msg_data, *msg_ptr;
 641         u16 remote_miu;
 642
 643         pr_debug("Send I frame len %zd\n", len);
 644
 645         local = sock->local;
 646         if (local == NULL)
 647                 return -ENODEV;
 648
 649         /* Remote is ready but has not acknowledged our frames */
 650         if((sock->remote_ready &&
 651             skb_queue_len(&sock->tx_pending_queue) >= sock->remote_rw &&
 652             skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) {
 653                 pr_err("Pending queue is full %d frames\n",
 654                        skb_queue_len(&sock->tx_pending_queue));
 655                 return -ENOBUFS;
 656         }
 657
 658         /* Remote is not ready and we've been queueing enough frames */
 659         if ((!sock->remote_ready &&
 660              skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) {
 661                 pr_err("Tx queue is full %d frames\n",
 662                        skb_queue_len(&sock->tx_queue));
 663                 return -ENOBUFS;
 664         }
 665
 666         msg_data = kmalloc(len, GFP_USER | __GFP_NOWARN);
 667         if (msg_data == NULL)
 668                 return -ENOMEM;
 669
 670         if (memcpy_from_msg(msg_data, msg, len)) {
 671                 kfree(msg_data);
 672                 return -EFAULT;
 673         }
 674
 675         remaining_len = len;
 676         msg_ptr = msg_data;
 677
 678         do {
 679                 remote_miu = sock->remote_miu > LLCP_MAX_MIU ?
 680                                 LLCP_DEFAULT_MIU : sock->remote_miu;
 681
 682                 frag_len = min_t(size_t, remote_miu, remaining_len);
 683
 684                 pr_debug("Fragment %zd bytes remaining %zd",
 685                          frag_len, remaining_len);
 686
 687                 pdu = llcp_allocate_pdu(sock, LLCP_PDU_I,
 688                                         frag_len + LLCP_SEQUENCE_SIZE);
 689                 if (pdu == NULL) {
 690                         kfree(msg_data);
 691                         return -ENOMEM;
 692                 }
 693
 694                 skb_put(pdu, LLCP_SEQUENCE_SIZE);
 695
 696                 if (likely(frag_len > 0))
 697                         memcpy(skb_put(pdu, frag_len), msg_ptr, frag_len);
 698
 699                 skb_queue_tail(&sock->tx_queue, pdu);
 700
 701                 lock_sock(sk);
 702
 703                 nfc_llcp_queue_i_frames(sock);
 704
 705                 release_sock(sk);
 706
 707                 remaining_len -= frag_len;
 708                 msg_ptr += frag_len;
 709         } while (remaining_len > 0);
 710
 711         kfree(msg_data);
 712
 713         return len;
 714 }
 715
 716 int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, u8 ssap, u8 dsap,
 717                            struct msghdr *msg, size_t len)
 718 {
 719         struct sk_buff *pdu;
 720         struct nfc_llcp_local *local;
 721         size_t frag_len = 0, remaining_len;
 722         u8 *msg_ptr, *msg_data;
 723         u16 remote_miu;
 724         int err;
 725
 726         pr_debug("Send UI frame len %zd\n", len);
 727
 728         local = sock->local;
 729         if (local == NULL)
 730                 return -ENODEV;
 731
 732         msg_data = kmalloc(len, GFP_USER | __GFP_NOWARN);
 733         if (msg_data == NULL)
 734                 return -ENOMEM;
 735
 736         if (memcpy_from_msg(msg_data, msg, len)) {
 737                 kfree(msg_data);
 738                 return -EFAULT;
 739         }
 740
 741         remaining_len = len;
 742         msg_ptr = msg_data;
 743
 744         do {
 745                 remote_miu = sock->remote_miu > LLCP_MAX_MIU ?
 746                                 local->remote_miu : sock->remote_miu;
 747
 748                 frag_len = min_t(size_t, remote_miu, remaining_len);
 749
 750                 pr_debug("Fragment %zd bytes remaining %zd",
 751                          frag_len, remaining_len);
 752
 753                 pdu = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT,
 754                                          frag_len + LLCP_HEADER_SIZE, &err);
 755                 if (pdu == NULL) {
 756                         pr_err("Could not allocate PDU\n");
 757                         continue;
 758                 }
 759
 760                 pdu = llcp_add_header(pdu, dsap, ssap, LLCP_PDU_UI);
 761
 762                 if (likely(frag_len > 0))
 763                         memcpy(skb_put(pdu, frag_len), msg_ptr, frag_len);
 764
 765                 /* No need to check for the peer RW for UI frames */
 766                 skb_queue_tail(&local->tx_queue, pdu);
 767
 768                 remaining_len -= frag_len;
 769                 msg_ptr += frag_len;
 770         } while (remaining_len > 0);
 771
 772         kfree(msg_data);
 773
 774         return len;
 775 }
 776
 777 int nfc_llcp_send_rr(struct nfc_llcp_sock *sock)
 778 {
 779         struct sk_buff *skb;
 780         struct nfc_llcp_local *local;
 781
 782         pr_debug("Send rr nr %d\n", sock->recv_n);
 783
 784         local = sock->local;
 785         if (local == NULL)
 786                 return -ENODEV;
 787
 788         skb = llcp_allocate_pdu(sock, LLCP_PDU_RR, LLCP_SEQUENCE_SIZE);
 789         if (skb == NULL)
 790                 return -ENOMEM;
 791
 792         skb_put(skb, LLCP_SEQUENCE_SIZE);
 793
 794         skb->data[2] = sock->recv_n;
 795
 796         skb_queue_head(&local->tx_queue, skb);
 797
 798         return 0;
 799 }