1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2011 Intel Corporation. All rights reserved. 4 */ 5 6 #define pr_fmt(fmt) "llcp: %s: " fmt, __func__ 7 8 #include <linux/init.h> 9 #include <linux/kernel.h> 10 #include <linux/module.h> 11 #include <linux/nfc.h> 12 13 #include <net/nfc/nfc.h> 14 15 #include "nfc.h" 16 #include "llcp.h" 17 18 static const u8 llcp_tlv_length[LLCP_TLV_MAX] = { 19 0, 20 1, /* VERSION */ 21 2, /* MIUX */ 22 2, /* WKS */ 23 1, /* LTO */ 24 1, /* RW */ 25 0, /* SN */ 26 1, /* OPT */ 27 0, /* SDREQ */ 28 2, /* SDRES */ 29 30 }; 31 32 static u8 llcp_tlv8(const u8 *tlv, u8 type) 33 { 34 if (tlv[0] != type || tlv[1] != llcp_tlv_length[tlv[0]]) 35 return 0; 36 37 return tlv[2]; 38 } 39 40 static u16 llcp_tlv16(const u8 *tlv, u8 type) 41 { 42 if (tlv[0] != type || tlv[1] != llcp_tlv_length[tlv[0]]) 43 return 0; 44 45 return be16_to_cpu(*((__be16 *)(tlv + 2))); 46 } 47 48 49 static u8 llcp_tlv_version(const u8 *tlv) 50 { 51 return llcp_tlv8(tlv, LLCP_TLV_VERSION); 52 } 53 54 static u16 llcp_tlv_miux(const u8 *tlv) 55 { 56 return llcp_tlv16(tlv, LLCP_TLV_MIUX) & 0x7ff; 57 } 58 59 static u16 llcp_tlv_wks(const u8 *tlv) 60 { 61 return llcp_tlv16(tlv, LLCP_TLV_WKS); 62 } 63 64 static u16 llcp_tlv_lto(const u8 *tlv) 65 { 66 return llcp_tlv8(tlv, LLCP_TLV_LTO); 67 } 68 69 static u8 llcp_tlv_opt(const u8 *tlv) 70 { 71 return llcp_tlv8(tlv, LLCP_TLV_OPT); 72 } 73 74 static u8 llcp_tlv_rw(const u8 *tlv) 75 { 76 return llcp_tlv8(tlv, LLCP_TLV_RW) & 0xf; 77 } 78 79 u8 *nfc_llcp_build_tlv(u8 type, const u8 *value, u8 value_length, u8 *tlv_length) 80 { 81 u8 *tlv, length; 82 83 pr_debug("type %d\n", type); 84 85 if (type >= LLCP_TLV_MAX) 86 return NULL; 87 88 length = llcp_tlv_length[type]; 89 if (length == 0 && value_length == 0) 90 return NULL; 91 else if (length == 0) 92 length = value_length; 93 94 *tlv_length = 2 + length; 95 tlv = kzalloc(2 + length, GFP_KERNEL); 96 if (tlv == NULL) 97 return tlv; 98 99 tlv[0] = type; 100 tlv[1] = length; 101 memcpy(tlv + 2, value, length); 102 103 return tlv; 104 } 105 106 struct nfc_llcp_sdp_tlv *nfc_llcp_build_sdres_tlv(u8 tid, u8 sap) 107 { 108 struct nfc_llcp_sdp_tlv *sdres; 109 u8 value[2]; 110 111 sdres = kzalloc_obj(struct nfc_llcp_sdp_tlv); 112 if (sdres == NULL) 113 return NULL; 114 115 value[0] = tid; 116 value[1] = sap; 117 118 sdres->tlv = nfc_llcp_build_tlv(LLCP_TLV_SDRES, value, 2, 119 &sdres->tlv_len); 120 if (sdres->tlv == NULL) { 121 kfree(sdres); 122 return NULL; 123 } 124 125 sdres->tid = tid; 126 sdres->sap = sap; 127 128 INIT_HLIST_NODE(&sdres->node); 129 130 return sdres; 131 } 132 133 struct nfc_llcp_sdp_tlv *nfc_llcp_build_sdreq_tlv(u8 tid, const char *uri, 134 size_t uri_len) 135 { 136 struct nfc_llcp_sdp_tlv *sdreq; 137 138 pr_debug("uri: %.*s, len: %zu\n", (int)uri_len, uri, uri_len); 139 140 /* sdreq->tlv_len is u8, takes uri_len, + 3 for header, + 1 for NULL */ 141 if (WARN_ON_ONCE(uri_len > U8_MAX - 4)) 142 return NULL; 143 144 sdreq = kzalloc_obj(struct nfc_llcp_sdp_tlv); 145 if (sdreq == NULL) 146 return NULL; 147 148 sdreq->tlv_len = uri_len + 3; 149 150 if (uri[uri_len - 1] == 0) 151 sdreq->tlv_len--; 152 153 sdreq->tlv = kzalloc(sdreq->tlv_len + 1, GFP_KERNEL); 154 if (sdreq->tlv == NULL) { 155 kfree(sdreq); 156 return NULL; 157 } 158 159 sdreq->tlv[0] = LLCP_TLV_SDREQ; 160 sdreq->tlv[1] = sdreq->tlv_len - 2; 161 sdreq->tlv[2] = tid; 162 163 sdreq->tid = tid; 164 sdreq->uri = sdreq->tlv + 3; 165 memcpy(sdreq->uri, uri, uri_len); 166 167 sdreq->time = jiffies; 168 169 INIT_HLIST_NODE(&sdreq->node); 170 171 return sdreq; 172 } 173 174 void nfc_llcp_free_sdp_tlv(struct nfc_llcp_sdp_tlv *sdp) 175 { 176 kfree(sdp->tlv); 177 kfree(sdp); 178 } 179 180 void nfc_llcp_free_sdp_tlv_list(struct hlist_head *head) 181 { 182 struct nfc_llcp_sdp_tlv *sdp; 183 struct hlist_node *n; 184 185 hlist_for_each_entry_safe(sdp, n, head, node) { 186 hlist_del(&sdp->node); 187 188 nfc_llcp_free_sdp_tlv(sdp); 189 } 190 } 191 192 int nfc_llcp_parse_gb_tlv(struct nfc_llcp_local *local, 193 const u8 *tlv_array, u16 tlv_array_len) 194 { 195 const u8 *tlv = tlv_array; 196 u8 type, length; 197 u16 offset = 0; 198 199 pr_debug("TLV array length %d\n", tlv_array_len); 200 201 if (local == NULL) 202 return -ENODEV; 203 204 while (offset < tlv_array_len) { 205 if (offset + 2 > tlv_array_len) 206 return -EINVAL; 207 208 type = tlv[0]; 209 length = tlv[1]; 210 211 if (offset + 2 + length > tlv_array_len) 212 return -EINVAL; 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 const u8 *tlv_array, u16 tlv_array_len) 251 { 252 const u8 *tlv = tlv_array; 253 u8 type, length; 254 u16 offset = 0; 255 256 pr_debug("TLV array length %d\n", tlv_array_len); 257 258 if (sock == NULL) 259 return -ENOTCONN; 260 261 while (offset < tlv_array_len) { 262 if (offset + 2 > tlv_array_len) 263 return -EINVAL; 264 265 type = tlv[0]; 266 length = tlv[1]; 267 268 if (offset + 2 + length > tlv_array_len) 269 return -EINVAL; 270 271 pr_debug("type 0x%x length %d\n", type, length); 272 273 switch (type) { 274 case LLCP_TLV_MIUX: 275 sock->remote_miu = llcp_tlv_miux(tlv) + 128; 276 break; 277 case LLCP_TLV_RW: 278 sock->remote_rw = llcp_tlv_rw(tlv); 279 break; 280 case LLCP_TLV_SN: 281 break; 282 default: 283 pr_err("Invalid gt tlv value 0x%x\n", type); 284 break; 285 } 286 287 offset += length + 2; 288 tlv += length + 2; 289 } 290 291 pr_debug("sock %p rw %d miu %d\n", sock, 292 sock->remote_rw, sock->remote_miu); 293 294 return 0; 295 } 296 297 static struct sk_buff *llcp_add_header(struct sk_buff *pdu, 298 u8 dsap, u8 ssap, u8 ptype) 299 { 300 u8 header[2]; 301 302 pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap); 303 304 header[0] = (u8)((dsap << 2) | (ptype >> 2)); 305 header[1] = (u8)((ptype << 6) | ssap); 306 307 pr_debug("header 0x%x 0x%x\n", header[0], header[1]); 308 309 skb_put_data(pdu, header, LLCP_HEADER_SIZE); 310 311 return pdu; 312 } 313 314 static struct sk_buff *llcp_add_tlv(struct sk_buff *pdu, const u8 *tlv, 315 u8 tlv_length) 316 { 317 /* XXX Add an skb length check */ 318 319 if (tlv == NULL) 320 return NULL; 321 322 skb_put_data(pdu, tlv, tlv_length); 323 324 return pdu; 325 } 326 327 static struct sk_buff *llcp_allocate_pdu(struct nfc_llcp_sock *sock, 328 u8 cmd, u16 size) 329 { 330 struct sk_buff *skb; 331 int err; 332 333 if (sock->ssap == 0) 334 return NULL; 335 336 skb = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT, 337 size + LLCP_HEADER_SIZE, &err); 338 if (skb == NULL) { 339 pr_err("Could not allocate PDU\n"); 340 return NULL; 341 } 342 343 skb = llcp_add_header(skb, sock->dsap, sock->ssap, cmd); 344 345 return skb; 346 } 347 348 int nfc_llcp_send_disconnect(struct nfc_llcp_sock *sock) 349 { 350 struct sk_buff *skb; 351 struct nfc_dev *dev; 352 struct nfc_llcp_local *local; 353 354 local = sock->local; 355 if (local == NULL) 356 return -ENODEV; 357 358 dev = sock->dev; 359 if (dev == NULL) 360 return -ENODEV; 361 362 skb = llcp_allocate_pdu(sock, LLCP_PDU_DISC, 0); 363 if (skb == NULL) 364 return -ENOMEM; 365 366 skb_queue_tail(&local->tx_queue, skb); 367 368 return 0; 369 } 370 371 int nfc_llcp_send_symm(struct nfc_dev *dev) 372 { 373 struct sk_buff *skb; 374 struct nfc_llcp_local *local; 375 u16 size = 0; 376 int err; 377 378 local = nfc_llcp_find_local(dev); 379 if (local == NULL) 380 return -ENODEV; 381 382 size += LLCP_HEADER_SIZE; 383 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; 384 385 skb = alloc_skb(size, GFP_KERNEL); 386 if (skb == NULL) { 387 err = -ENOMEM; 388 goto out; 389 } 390 391 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE); 392 393 skb = llcp_add_header(skb, 0, 0, LLCP_PDU_SYMM); 394 395 __net_timestamp(skb); 396 397 nfc_llcp_send_to_raw_sock(local, skb, NFC_DIRECTION_TX); 398 399 err = nfc_data_exchange(dev, local->target_idx, skb, 400 nfc_llcp_recv, local); 401 out: 402 nfc_llcp_local_put(local); 403 return err; 404 } 405 406 int nfc_llcp_send_connect(struct nfc_llcp_sock *sock) 407 { 408 struct nfc_llcp_local *local; 409 struct sk_buff *skb; 410 const u8 *service_name_tlv = NULL; 411 const u8 *miux_tlv = NULL; 412 const u8 *rw_tlv = NULL; 413 u8 service_name_tlv_length = 0; 414 u8 miux_tlv_length, rw_tlv_length, rw; 415 int err; 416 u16 size = 0; 417 __be16 miux; 418 419 local = sock->local; 420 if (local == NULL) 421 return -ENODEV; 422 423 if (sock->service_name != NULL) { 424 service_name_tlv = nfc_llcp_build_tlv(LLCP_TLV_SN, 425 sock->service_name, 426 sock->service_name_len, 427 &service_name_tlv_length); 428 if (!service_name_tlv) { 429 err = -ENOMEM; 430 goto error_tlv; 431 } 432 size += service_name_tlv_length; 433 } 434 435 /* If the socket parameters are not set, use the local ones */ 436 miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ? 437 local->miux : sock->miux; 438 rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw; 439 440 miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0, 441 &miux_tlv_length); 442 if (!miux_tlv) { 443 err = -ENOMEM; 444 goto error_tlv; 445 } 446 size += miux_tlv_length; 447 448 rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length); 449 if (!rw_tlv) { 450 err = -ENOMEM; 451 goto error_tlv; 452 } 453 size += rw_tlv_length; 454 455 pr_debug("SKB size %d SN length %zu\n", size, sock->service_name_len); 456 457 skb = llcp_allocate_pdu(sock, LLCP_PDU_CONNECT, size); 458 if (skb == NULL) { 459 err = -ENOMEM; 460 goto error_tlv; 461 } 462 463 llcp_add_tlv(skb, service_name_tlv, service_name_tlv_length); 464 llcp_add_tlv(skb, miux_tlv, miux_tlv_length); 465 llcp_add_tlv(skb, rw_tlv, rw_tlv_length); 466 467 skb_queue_tail(&local->tx_queue, skb); 468 469 err = 0; 470 471 error_tlv: 472 if (err) 473 pr_err("error %d\n", err); 474 475 kfree(service_name_tlv); 476 kfree(miux_tlv); 477 kfree(rw_tlv); 478 479 return err; 480 } 481 482 int nfc_llcp_send_cc(struct nfc_llcp_sock *sock) 483 { 484 struct nfc_llcp_local *local; 485 struct sk_buff *skb; 486 const u8 *miux_tlv = NULL; 487 const u8 *rw_tlv = NULL; 488 u8 miux_tlv_length, rw_tlv_length, rw; 489 int err; 490 u16 size = 0; 491 __be16 miux; 492 493 local = sock->local; 494 if (local == NULL) 495 return -ENODEV; 496 497 /* If the socket parameters are not set, use the local ones */ 498 miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ? 499 local->miux : sock->miux; 500 rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw; 501 502 miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0, 503 &miux_tlv_length); 504 if (!miux_tlv) { 505 err = -ENOMEM; 506 goto error_tlv; 507 } 508 size += miux_tlv_length; 509 510 rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length); 511 if (!rw_tlv) { 512 err = -ENOMEM; 513 goto error_tlv; 514 } 515 size += rw_tlv_length; 516 517 skb = llcp_allocate_pdu(sock, LLCP_PDU_CC, size); 518 if (skb == NULL) { 519 err = -ENOMEM; 520 goto error_tlv; 521 } 522 523 llcp_add_tlv(skb, miux_tlv, miux_tlv_length); 524 llcp_add_tlv(skb, rw_tlv, rw_tlv_length); 525 526 skb_queue_tail(&local->tx_queue, skb); 527 528 err = 0; 529 530 error_tlv: 531 if (err) 532 pr_err("error %d\n", err); 533 534 kfree(miux_tlv); 535 kfree(rw_tlv); 536 537 return err; 538 } 539 540 static struct sk_buff *nfc_llcp_allocate_snl(struct nfc_llcp_local *local, 541 size_t tlv_length) 542 { 543 struct sk_buff *skb; 544 struct nfc_dev *dev; 545 u16 size = 0; 546 547 if (local == NULL) 548 return ERR_PTR(-ENODEV); 549 550 dev = local->dev; 551 if (dev == NULL) 552 return ERR_PTR(-ENODEV); 553 554 size += LLCP_HEADER_SIZE; 555 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; 556 size += tlv_length; 557 558 skb = alloc_skb(size, GFP_KERNEL); 559 if (skb == NULL) 560 return ERR_PTR(-ENOMEM); 561 562 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE); 563 564 skb = llcp_add_header(skb, LLCP_SAP_SDP, LLCP_SAP_SDP, LLCP_PDU_SNL); 565 566 return skb; 567 } 568 569 int nfc_llcp_send_snl_sdres(struct nfc_llcp_local *local, 570 struct hlist_head *tlv_list, size_t tlvs_len) 571 { 572 struct nfc_llcp_sdp_tlv *sdp; 573 struct hlist_node *n; 574 struct sk_buff *skb; 575 576 skb = nfc_llcp_allocate_snl(local, tlvs_len); 577 if (IS_ERR(skb)) 578 return PTR_ERR(skb); 579 580 hlist_for_each_entry_safe(sdp, n, tlv_list, node) { 581 skb_put_data(skb, sdp->tlv, sdp->tlv_len); 582 583 hlist_del(&sdp->node); 584 585 nfc_llcp_free_sdp_tlv(sdp); 586 } 587 588 skb_queue_tail(&local->tx_queue, skb); 589 590 return 0; 591 } 592 593 int nfc_llcp_send_snl_sdreq(struct nfc_llcp_local *local, 594 struct hlist_head *tlv_list, size_t tlvs_len) 595 { 596 struct nfc_llcp_sdp_tlv *sdreq; 597 struct hlist_node *n; 598 struct sk_buff *skb; 599 600 skb = nfc_llcp_allocate_snl(local, tlvs_len); 601 if (IS_ERR(skb)) 602 return PTR_ERR(skb); 603 604 mutex_lock(&local->sdreq_lock); 605 606 if (hlist_empty(&local->pending_sdreqs)) 607 mod_timer(&local->sdreq_timer, 608 jiffies + msecs_to_jiffies(3 * local->remote_lto)); 609 610 hlist_for_each_entry_safe(sdreq, n, tlv_list, node) { 611 pr_debug("tid %d for %s\n", sdreq->tid, sdreq->uri); 612 613 skb_put_data(skb, sdreq->tlv, sdreq->tlv_len); 614 615 hlist_del(&sdreq->node); 616 617 hlist_add_head(&sdreq->node, &local->pending_sdreqs); 618 } 619 620 mutex_unlock(&local->sdreq_lock); 621 622 skb_queue_tail(&local->tx_queue, skb); 623 624 return 0; 625 } 626 627 int nfc_llcp_send_dm(struct nfc_llcp_local *local, u8 ssap, u8 dsap, u8 reason) 628 { 629 struct sk_buff *skb; 630 struct nfc_dev *dev; 631 u16 size = 1; /* Reason code */ 632 633 pr_debug("Sending DM reason 0x%x\n", reason); 634 635 if (local == NULL) 636 return -ENODEV; 637 638 dev = local->dev; 639 if (dev == NULL) 640 return -ENODEV; 641 642 size += LLCP_HEADER_SIZE; 643 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; 644 645 skb = alloc_skb(size, GFP_KERNEL); 646 if (skb == NULL) 647 return -ENOMEM; 648 649 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE); 650 651 skb = llcp_add_header(skb, dsap, ssap, LLCP_PDU_DM); 652 653 skb_put_data(skb, &reason, 1); 654 655 skb_queue_head(&local->tx_queue, skb); 656 657 return 0; 658 } 659 660 int nfc_llcp_send_i_frame(struct nfc_llcp_sock *sock, 661 struct msghdr *msg, size_t len) 662 { 663 struct sk_buff *pdu; 664 struct sock *sk = &sock->sk; 665 struct nfc_llcp_local *local; 666 size_t frag_len = 0, remaining_len; 667 u8 *msg_data, *msg_ptr; 668 u16 remote_miu; 669 670 pr_debug("Send I frame len %zd\n", len); 671 672 local = sock->local; 673 if (local == NULL) 674 return -ENODEV; 675 676 /* Remote is ready but has not acknowledged our frames */ 677 if((sock->remote_ready && 678 skb_queue_len(&sock->tx_pending_queue) >= sock->remote_rw && 679 skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) { 680 pr_err("Pending queue is full %d frames\n", 681 skb_queue_len(&sock->tx_pending_queue)); 682 return -ENOBUFS; 683 } 684 685 /* Remote is not ready and we've been queueing enough frames */ 686 if ((!sock->remote_ready && 687 skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) { 688 pr_err("Tx queue is full %d frames\n", 689 skb_queue_len(&sock->tx_queue)); 690 return -ENOBUFS; 691 } 692 693 msg_data = kmalloc(len, GFP_USER | __GFP_NOWARN); 694 if (msg_data == NULL) 695 return -ENOMEM; 696 697 if (memcpy_from_msg(msg_data, msg, len)) { 698 kfree(msg_data); 699 return -EFAULT; 700 } 701 702 remaining_len = len; 703 msg_ptr = msg_data; 704 705 do { 706 remote_miu = sock->remote_miu > LLCP_MAX_MIU ? 707 LLCP_DEFAULT_MIU : sock->remote_miu; 708 709 frag_len = min_t(size_t, remote_miu, remaining_len); 710 711 pr_debug("Fragment %zd bytes remaining %zd", 712 frag_len, remaining_len); 713 714 pdu = llcp_allocate_pdu(sock, LLCP_PDU_I, 715 frag_len + LLCP_SEQUENCE_SIZE); 716 if (pdu == NULL) { 717 kfree(msg_data); 718 return -ENOMEM; 719 } 720 721 skb_put(pdu, LLCP_SEQUENCE_SIZE); 722 723 if (likely(frag_len > 0)) 724 skb_put_data(pdu, msg_ptr, frag_len); 725 726 skb_queue_tail(&sock->tx_queue, pdu); 727 728 lock_sock(sk); 729 730 nfc_llcp_queue_i_frames(sock); 731 732 release_sock(sk); 733 734 remaining_len -= frag_len; 735 msg_ptr += frag_len; 736 } while (remaining_len > 0); 737 738 kfree(msg_data); 739 740 return len; 741 } 742 743 int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, u8 ssap, u8 dsap, 744 struct msghdr *msg, size_t len) 745 { 746 struct sk_buff *pdu; 747 struct nfc_llcp_local *local; 748 size_t frag_len = 0, remaining_len; 749 u8 *msg_ptr, *msg_data; 750 u16 remote_miu; 751 int err; 752 753 pr_debug("Send UI frame len %zd\n", len); 754 755 local = sock->local; 756 if (local == NULL) 757 return -ENODEV; 758 759 msg_data = kmalloc(len, GFP_USER | __GFP_NOWARN); 760 if (msg_data == NULL) 761 return -ENOMEM; 762 763 if (memcpy_from_msg(msg_data, msg, len)) { 764 kfree(msg_data); 765 return -EFAULT; 766 } 767 768 remaining_len = len; 769 msg_ptr = msg_data; 770 771 do { 772 remote_miu = sock->remote_miu > LLCP_MAX_MIU ? 773 local->remote_miu : sock->remote_miu; 774 775 frag_len = min_t(size_t, remote_miu, remaining_len); 776 777 pr_debug("Fragment %zd bytes remaining %zd", 778 frag_len, remaining_len); 779 780 pdu = nfc_alloc_send_skb(sock->dev, &sock->sk, 0, 781 frag_len + LLCP_HEADER_SIZE, &err); 782 if (pdu == NULL) { 783 pr_err("Could not allocate PDU (error=%d)\n", err); 784 len -= remaining_len; 785 if (len == 0) 786 len = err; 787 break; 788 } 789 790 pdu = llcp_add_header(pdu, dsap, ssap, LLCP_PDU_UI); 791 792 if (likely(frag_len > 0)) 793 skb_put_data(pdu, msg_ptr, frag_len); 794 795 spin_lock(&local->tx_queue.lock); 796 797 if (list_empty(&local->list)) { 798 spin_unlock(&local->tx_queue.lock); 799 800 kfree_skb(pdu); 801 802 len -= remaining_len; 803 if (len == 0) 804 len = -ENXIO; 805 break; 806 } 807 808 /* No need to check for the peer RW for UI frames */ 809 __skb_queue_tail(&local->tx_queue, pdu); 810 811 spin_unlock(&local->tx_queue.lock); 812 813 remaining_len -= frag_len; 814 msg_ptr += frag_len; 815 } while (remaining_len > 0); 816 817 kfree(msg_data); 818 819 return len; 820 } 821 822 int nfc_llcp_send_rr(struct nfc_llcp_sock *sock) 823 { 824 struct sk_buff *skb; 825 struct nfc_llcp_local *local; 826 827 pr_debug("Send rr nr %d\n", sock->recv_n); 828 829 local = sock->local; 830 if (local == NULL) 831 return -ENODEV; 832 833 skb = llcp_allocate_pdu(sock, LLCP_PDU_RR, LLCP_SEQUENCE_SIZE); 834 if (skb == NULL) 835 return -ENOMEM; 836 837 skb_put(skb, LLCP_SEQUENCE_SIZE); 838 839 skb->data[2] = sock->recv_n; 840 841 skb_queue_head(&local->tx_queue, skb); 842 843 return 0; 844 } 845