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(sizeof(struct nfc_llcp_sdp_tlv), GFP_KERNEL); 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", 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(sizeof(struct nfc_llcp_sdp_tlv), GFP_KERNEL); 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, offset = 0; 197 198 pr_debug("TLV array length %d\n", tlv_array_len); 199 200 if (local == NULL) 201 return -ENODEV; 202 203 while (offset < tlv_array_len) { 204 type = tlv[0]; 205 length = tlv[1]; 206 207 pr_debug("type 0x%x length %d\n", type, length); 208 209 switch (type) { 210 case LLCP_TLV_VERSION: 211 local->remote_version = llcp_tlv_version(tlv); 212 break; 213 case LLCP_TLV_MIUX: 214 local->remote_miu = llcp_tlv_miux(tlv) + 128; 215 break; 216 case LLCP_TLV_WKS: 217 local->remote_wks = llcp_tlv_wks(tlv); 218 break; 219 case LLCP_TLV_LTO: 220 local->remote_lto = llcp_tlv_lto(tlv) * 10; 221 break; 222 case LLCP_TLV_OPT: 223 local->remote_opt = llcp_tlv_opt(tlv); 224 break; 225 default: 226 pr_err("Invalid gt tlv value 0x%x\n", type); 227 break; 228 } 229 230 offset += length + 2; 231 tlv += length + 2; 232 } 233 234 pr_debug("version 0x%x miu %d lto %d opt 0x%x wks 0x%x\n", 235 local->remote_version, local->remote_miu, 236 local->remote_lto, local->remote_opt, 237 local->remote_wks); 238 239 return 0; 240 } 241 242 int nfc_llcp_parse_connection_tlv(struct nfc_llcp_sock *sock, 243 const u8 *tlv_array, u16 tlv_array_len) 244 { 245 const u8 *tlv = tlv_array; 246 u8 type, length, offset = 0; 247 248 pr_debug("TLV array length %d\n", tlv_array_len); 249 250 if (sock == NULL) 251 return -ENOTCONN; 252 253 while (offset < tlv_array_len) { 254 type = tlv[0]; 255 length = tlv[1]; 256 257 pr_debug("type 0x%x length %d\n", type, length); 258 259 switch (type) { 260 case LLCP_TLV_MIUX: 261 sock->remote_miu = llcp_tlv_miux(tlv) + 128; 262 break; 263 case LLCP_TLV_RW: 264 sock->remote_rw = llcp_tlv_rw(tlv); 265 break; 266 case LLCP_TLV_SN: 267 break; 268 default: 269 pr_err("Invalid gt tlv value 0x%x\n", type); 270 break; 271 } 272 273 offset += length + 2; 274 tlv += length + 2; 275 } 276 277 pr_debug("sock %p rw %d miu %d\n", sock, 278 sock->remote_rw, sock->remote_miu); 279 280 return 0; 281 } 282 283 static struct sk_buff *llcp_add_header(struct sk_buff *pdu, 284 u8 dsap, u8 ssap, u8 ptype) 285 { 286 u8 header[2]; 287 288 pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap); 289 290 header[0] = (u8)((dsap << 2) | (ptype >> 2)); 291 header[1] = (u8)((ptype << 6) | ssap); 292 293 pr_debug("header 0x%x 0x%x\n", header[0], header[1]); 294 295 skb_put_data(pdu, header, LLCP_HEADER_SIZE); 296 297 return pdu; 298 } 299 300 static struct sk_buff *llcp_add_tlv(struct sk_buff *pdu, const u8 *tlv, 301 u8 tlv_length) 302 { 303 /* XXX Add an skb length check */ 304 305 if (tlv == NULL) 306 return NULL; 307 308 skb_put_data(pdu, tlv, tlv_length); 309 310 return pdu; 311 } 312 313 static struct sk_buff *llcp_allocate_pdu(struct nfc_llcp_sock *sock, 314 u8 cmd, u16 size) 315 { 316 struct sk_buff *skb; 317 int err; 318 319 if (sock->ssap == 0) 320 return NULL; 321 322 skb = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT, 323 size + LLCP_HEADER_SIZE, &err); 324 if (skb == NULL) { 325 pr_err("Could not allocate PDU\n"); 326 return NULL; 327 } 328 329 skb = llcp_add_header(skb, sock->dsap, sock->ssap, cmd); 330 331 return skb; 332 } 333 334 int nfc_llcp_send_disconnect(struct nfc_llcp_sock *sock) 335 { 336 struct sk_buff *skb; 337 struct nfc_dev *dev; 338 struct nfc_llcp_local *local; 339 340 local = sock->local; 341 if (local == NULL) 342 return -ENODEV; 343 344 dev = sock->dev; 345 if (dev == NULL) 346 return -ENODEV; 347 348 skb = llcp_allocate_pdu(sock, LLCP_PDU_DISC, 0); 349 if (skb == NULL) 350 return -ENOMEM; 351 352 skb_queue_tail(&local->tx_queue, skb); 353 354 return 0; 355 } 356 357 int nfc_llcp_send_symm(struct nfc_dev *dev) 358 { 359 struct sk_buff *skb; 360 struct nfc_llcp_local *local; 361 u16 size = 0; 362 int err; 363 364 local = nfc_llcp_find_local(dev); 365 if (local == NULL) 366 return -ENODEV; 367 368 size += LLCP_HEADER_SIZE; 369 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; 370 371 skb = alloc_skb(size, GFP_KERNEL); 372 if (skb == NULL) { 373 err = -ENOMEM; 374 goto out; 375 } 376 377 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE); 378 379 skb = llcp_add_header(skb, 0, 0, LLCP_PDU_SYMM); 380 381 __net_timestamp(skb); 382 383 nfc_llcp_send_to_raw_sock(local, skb, NFC_DIRECTION_TX); 384 385 err = nfc_data_exchange(dev, local->target_idx, skb, 386 nfc_llcp_recv, local); 387 out: 388 nfc_llcp_local_put(local); 389 return err; 390 } 391 392 int nfc_llcp_send_connect(struct nfc_llcp_sock *sock) 393 { 394 struct nfc_llcp_local *local; 395 struct sk_buff *skb; 396 const u8 *service_name_tlv = NULL; 397 const u8 *miux_tlv = NULL; 398 const u8 *rw_tlv = NULL; 399 u8 service_name_tlv_length = 0; 400 u8 miux_tlv_length, rw_tlv_length, rw; 401 int err; 402 u16 size = 0; 403 __be16 miux; 404 405 local = sock->local; 406 if (local == NULL) 407 return -ENODEV; 408 409 if (sock->service_name != NULL) { 410 service_name_tlv = nfc_llcp_build_tlv(LLCP_TLV_SN, 411 sock->service_name, 412 sock->service_name_len, 413 &service_name_tlv_length); 414 if (!service_name_tlv) { 415 err = -ENOMEM; 416 goto error_tlv; 417 } 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 if (!miux_tlv) { 429 err = -ENOMEM; 430 goto error_tlv; 431 } 432 size += miux_tlv_length; 433 434 rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length); 435 if (!rw_tlv) { 436 err = -ENOMEM; 437 goto error_tlv; 438 } 439 size += rw_tlv_length; 440 441 pr_debug("SKB size %d SN length %zu\n", size, sock->service_name_len); 442 443 skb = llcp_allocate_pdu(sock, LLCP_PDU_CONNECT, size); 444 if (skb == NULL) { 445 err = -ENOMEM; 446 goto error_tlv; 447 } 448 449 llcp_add_tlv(skb, service_name_tlv, service_name_tlv_length); 450 llcp_add_tlv(skb, miux_tlv, miux_tlv_length); 451 llcp_add_tlv(skb, rw_tlv, rw_tlv_length); 452 453 skb_queue_tail(&local->tx_queue, skb); 454 455 err = 0; 456 457 error_tlv: 458 if (err) 459 pr_err("error %d\n", err); 460 461 kfree(service_name_tlv); 462 kfree(miux_tlv); 463 kfree(rw_tlv); 464 465 return err; 466 } 467 468 int nfc_llcp_send_cc(struct nfc_llcp_sock *sock) 469 { 470 struct nfc_llcp_local *local; 471 struct sk_buff *skb; 472 const u8 *miux_tlv = NULL; 473 const u8 *rw_tlv = NULL; 474 u8 miux_tlv_length, rw_tlv_length, rw; 475 int err; 476 u16 size = 0; 477 __be16 miux; 478 479 local = sock->local; 480 if (local == NULL) 481 return -ENODEV; 482 483 /* If the socket parameters are not set, use the local ones */ 484 miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ? 485 local->miux : sock->miux; 486 rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw; 487 488 miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0, 489 &miux_tlv_length); 490 if (!miux_tlv) { 491 err = -ENOMEM; 492 goto error_tlv; 493 } 494 size += miux_tlv_length; 495 496 rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length); 497 if (!rw_tlv) { 498 err = -ENOMEM; 499 goto error_tlv; 500 } 501 size += rw_tlv_length; 502 503 skb = llcp_allocate_pdu(sock, LLCP_PDU_CC, size); 504 if (skb == NULL) { 505 err = -ENOMEM; 506 goto error_tlv; 507 } 508 509 llcp_add_tlv(skb, miux_tlv, miux_tlv_length); 510 llcp_add_tlv(skb, rw_tlv, rw_tlv_length); 511 512 skb_queue_tail(&local->tx_queue, skb); 513 514 err = 0; 515 516 error_tlv: 517 if (err) 518 pr_err("error %d\n", err); 519 520 kfree(miux_tlv); 521 kfree(rw_tlv); 522 523 return err; 524 } 525 526 static struct sk_buff *nfc_llcp_allocate_snl(struct nfc_llcp_local *local, 527 size_t tlv_length) 528 { 529 struct sk_buff *skb; 530 struct nfc_dev *dev; 531 u16 size = 0; 532 533 if (local == NULL) 534 return ERR_PTR(-ENODEV); 535 536 dev = local->dev; 537 if (dev == NULL) 538 return ERR_PTR(-ENODEV); 539 540 size += LLCP_HEADER_SIZE; 541 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; 542 size += tlv_length; 543 544 skb = alloc_skb(size, GFP_KERNEL); 545 if (skb == NULL) 546 return ERR_PTR(-ENOMEM); 547 548 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE); 549 550 skb = llcp_add_header(skb, LLCP_SAP_SDP, LLCP_SAP_SDP, LLCP_PDU_SNL); 551 552 return skb; 553 } 554 555 int nfc_llcp_send_snl_sdres(struct nfc_llcp_local *local, 556 struct hlist_head *tlv_list, size_t tlvs_len) 557 { 558 struct nfc_llcp_sdp_tlv *sdp; 559 struct hlist_node *n; 560 struct sk_buff *skb; 561 562 skb = nfc_llcp_allocate_snl(local, tlvs_len); 563 if (IS_ERR(skb)) 564 return PTR_ERR(skb); 565 566 hlist_for_each_entry_safe(sdp, n, tlv_list, node) { 567 skb_put_data(skb, sdp->tlv, sdp->tlv_len); 568 569 hlist_del(&sdp->node); 570 571 nfc_llcp_free_sdp_tlv(sdp); 572 } 573 574 skb_queue_tail(&local->tx_queue, skb); 575 576 return 0; 577 } 578 579 int nfc_llcp_send_snl_sdreq(struct nfc_llcp_local *local, 580 struct hlist_head *tlv_list, size_t tlvs_len) 581 { 582 struct nfc_llcp_sdp_tlv *sdreq; 583 struct hlist_node *n; 584 struct sk_buff *skb; 585 586 skb = nfc_llcp_allocate_snl(local, tlvs_len); 587 if (IS_ERR(skb)) 588 return PTR_ERR(skb); 589 590 mutex_lock(&local->sdreq_lock); 591 592 if (hlist_empty(&local->pending_sdreqs)) 593 mod_timer(&local->sdreq_timer, 594 jiffies + msecs_to_jiffies(3 * local->remote_lto)); 595 596 hlist_for_each_entry_safe(sdreq, n, tlv_list, node) { 597 pr_debug("tid %d for %s\n", sdreq->tid, sdreq->uri); 598 599 skb_put_data(skb, sdreq->tlv, sdreq->tlv_len); 600 601 hlist_del(&sdreq->node); 602 603 hlist_add_head(&sdreq->node, &local->pending_sdreqs); 604 } 605 606 mutex_unlock(&local->sdreq_lock); 607 608 skb_queue_tail(&local->tx_queue, skb); 609 610 return 0; 611 } 612 613 int nfc_llcp_send_dm(struct nfc_llcp_local *local, u8 ssap, u8 dsap, u8 reason) 614 { 615 struct sk_buff *skb; 616 struct nfc_dev *dev; 617 u16 size = 1; /* Reason code */ 618 619 pr_debug("Sending DM reason 0x%x\n", reason); 620 621 if (local == NULL) 622 return -ENODEV; 623 624 dev = local->dev; 625 if (dev == NULL) 626 return -ENODEV; 627 628 size += LLCP_HEADER_SIZE; 629 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; 630 631 skb = alloc_skb(size, GFP_KERNEL); 632 if (skb == NULL) 633 return -ENOMEM; 634 635 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE); 636 637 skb = llcp_add_header(skb, dsap, ssap, LLCP_PDU_DM); 638 639 skb_put_data(skb, &reason, 1); 640 641 skb_queue_head(&local->tx_queue, skb); 642 643 return 0; 644 } 645 646 int nfc_llcp_send_i_frame(struct nfc_llcp_sock *sock, 647 struct msghdr *msg, size_t len) 648 { 649 struct sk_buff *pdu; 650 struct sock *sk = &sock->sk; 651 struct nfc_llcp_local *local; 652 size_t frag_len = 0, remaining_len; 653 u8 *msg_data, *msg_ptr; 654 u16 remote_miu; 655 656 pr_debug("Send I frame len %zd\n", len); 657 658 local = sock->local; 659 if (local == NULL) 660 return -ENODEV; 661 662 /* Remote is ready but has not acknowledged our frames */ 663 if((sock->remote_ready && 664 skb_queue_len(&sock->tx_pending_queue) >= sock->remote_rw && 665 skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) { 666 pr_err("Pending queue is full %d frames\n", 667 skb_queue_len(&sock->tx_pending_queue)); 668 return -ENOBUFS; 669 } 670 671 /* Remote is not ready and we've been queueing enough frames */ 672 if ((!sock->remote_ready && 673 skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) { 674 pr_err("Tx queue is full %d frames\n", 675 skb_queue_len(&sock->tx_queue)); 676 return -ENOBUFS; 677 } 678 679 msg_data = kmalloc(len, GFP_USER | __GFP_NOWARN); 680 if (msg_data == NULL) 681 return -ENOMEM; 682 683 if (memcpy_from_msg(msg_data, msg, len)) { 684 kfree(msg_data); 685 return -EFAULT; 686 } 687 688 remaining_len = len; 689 msg_ptr = msg_data; 690 691 do { 692 remote_miu = sock->remote_miu > LLCP_MAX_MIU ? 693 LLCP_DEFAULT_MIU : sock->remote_miu; 694 695 frag_len = min_t(size_t, remote_miu, remaining_len); 696 697 pr_debug("Fragment %zd bytes remaining %zd", 698 frag_len, remaining_len); 699 700 pdu = llcp_allocate_pdu(sock, LLCP_PDU_I, 701 frag_len + LLCP_SEQUENCE_SIZE); 702 if (pdu == NULL) { 703 kfree(msg_data); 704 return -ENOMEM; 705 } 706 707 skb_put(pdu, LLCP_SEQUENCE_SIZE); 708 709 if (likely(frag_len > 0)) 710 skb_put_data(pdu, msg_ptr, frag_len); 711 712 skb_queue_tail(&sock->tx_queue, pdu); 713 714 lock_sock(sk); 715 716 nfc_llcp_queue_i_frames(sock); 717 718 release_sock(sk); 719 720 remaining_len -= frag_len; 721 msg_ptr += frag_len; 722 } while (remaining_len > 0); 723 724 kfree(msg_data); 725 726 return len; 727 } 728 729 int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, u8 ssap, u8 dsap, 730 struct msghdr *msg, size_t len) 731 { 732 struct sk_buff *pdu; 733 struct nfc_llcp_local *local; 734 size_t frag_len = 0, remaining_len; 735 u8 *msg_ptr, *msg_data; 736 u16 remote_miu; 737 int err; 738 739 pr_debug("Send UI frame len %zd\n", len); 740 741 local = sock->local; 742 if (local == NULL) 743 return -ENODEV; 744 745 msg_data = kmalloc(len, GFP_USER | __GFP_NOWARN); 746 if (msg_data == NULL) 747 return -ENOMEM; 748 749 if (memcpy_from_msg(msg_data, msg, len)) { 750 kfree(msg_data); 751 return -EFAULT; 752 } 753 754 remaining_len = len; 755 msg_ptr = msg_data; 756 757 do { 758 remote_miu = sock->remote_miu > LLCP_MAX_MIU ? 759 local->remote_miu : sock->remote_miu; 760 761 frag_len = min_t(size_t, remote_miu, remaining_len); 762 763 pr_debug("Fragment %zd bytes remaining %zd", 764 frag_len, remaining_len); 765 766 pdu = nfc_alloc_send_skb(sock->dev, &sock->sk, 0, 767 frag_len + LLCP_HEADER_SIZE, &err); 768 if (pdu == NULL) { 769 pr_err("Could not allocate PDU (error=%d)\n", err); 770 len -= remaining_len; 771 if (len == 0) 772 len = err; 773 break; 774 } 775 776 pdu = llcp_add_header(pdu, dsap, ssap, LLCP_PDU_UI); 777 778 if (likely(frag_len > 0)) 779 skb_put_data(pdu, msg_ptr, frag_len); 780 781 /* No need to check for the peer RW for UI frames */ 782 skb_queue_tail(&local->tx_queue, pdu); 783 784 remaining_len -= frag_len; 785 msg_ptr += frag_len; 786 } while (remaining_len > 0); 787 788 kfree(msg_data); 789 790 return len; 791 } 792 793 int nfc_llcp_send_rr(struct nfc_llcp_sock *sock) 794 { 795 struct sk_buff *skb; 796 struct nfc_llcp_local *local; 797 798 pr_debug("Send rr nr %d\n", sock->recv_n); 799 800 local = sock->local; 801 if (local == NULL) 802 return -ENODEV; 803 804 skb = llcp_allocate_pdu(sock, LLCP_PDU_RR, LLCP_SEQUENCE_SIZE); 805 if (skb == NULL) 806 return -ENOMEM; 807 808 skb_put(skb, LLCP_SEQUENCE_SIZE); 809 810 skb->data[2] = sock->recv_n; 811 812 skb_queue_head(&local->tx_queue, skb); 813 814 return 0; 815 } 816