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 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(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(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(u8 *tlv) 50 { 51 return llcp_tlv8(tlv, LLCP_TLV_VERSION); 52 } 53 54 static u16 llcp_tlv_miux(u8 *tlv) 55 { 56 return llcp_tlv16(tlv, LLCP_TLV_MIUX) & 0x7ff; 57 } 58 59 static u16 llcp_tlv_wks(u8 *tlv) 60 { 61 return llcp_tlv16(tlv, LLCP_TLV_WKS); 62 } 63 64 static u16 llcp_tlv_lto(u8 *tlv) 65 { 66 return llcp_tlv8(tlv, LLCP_TLV_LTO); 67 } 68 69 static u8 llcp_tlv_opt(u8 *tlv) 70 { 71 return llcp_tlv8(tlv, LLCP_TLV_OPT); 72 } 73 74 static u8 llcp_tlv_rw(u8 *tlv) 75 { 76 return llcp_tlv8(tlv, LLCP_TLV_RW) & 0xf; 77 } 78 79 u8 *nfc_llcp_build_tlv(u8 type, 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, 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 u8 *tlv_array, u16 tlv_array_len) 194 { 195 u8 *tlv = tlv_array, type, length, offset = 0; 196 197 pr_debug("TLV array length %d\n", tlv_array_len); 198 199 if (local == NULL) 200 return -ENODEV; 201 202 while (offset < tlv_array_len) { 203 type = tlv[0]; 204 length = tlv[1]; 205 206 pr_debug("type 0x%x length %d\n", type, length); 207 208 switch (type) { 209 case LLCP_TLV_VERSION: 210 local->remote_version = llcp_tlv_version(tlv); 211 break; 212 case LLCP_TLV_MIUX: 213 local->remote_miu = llcp_tlv_miux(tlv) + 128; 214 break; 215 case LLCP_TLV_WKS: 216 local->remote_wks = llcp_tlv_wks(tlv); 217 break; 218 case LLCP_TLV_LTO: 219 local->remote_lto = llcp_tlv_lto(tlv) * 10; 220 break; 221 case LLCP_TLV_OPT: 222 local->remote_opt = llcp_tlv_opt(tlv); 223 break; 224 default: 225 pr_err("Invalid gt tlv value 0x%x\n", type); 226 break; 227 } 228 229 offset += length + 2; 230 tlv += length + 2; 231 } 232 233 pr_debug("version 0x%x miu %d lto %d opt 0x%x wks 0x%x\n", 234 local->remote_version, local->remote_miu, 235 local->remote_lto, local->remote_opt, 236 local->remote_wks); 237 238 return 0; 239 } 240 241 int nfc_llcp_parse_connection_tlv(struct nfc_llcp_sock *sock, 242 u8 *tlv_array, u16 tlv_array_len) 243 { 244 u8 *tlv = tlv_array, type, length, offset = 0; 245 246 pr_debug("TLV array length %d\n", tlv_array_len); 247 248 if (sock == NULL) 249 return -ENOTCONN; 250 251 while (offset < tlv_array_len) { 252 type = tlv[0]; 253 length = tlv[1]; 254 255 pr_debug("type 0x%x length %d\n", type, length); 256 257 switch (type) { 258 case LLCP_TLV_MIUX: 259 sock->remote_miu = llcp_tlv_miux(tlv) + 128; 260 break; 261 case LLCP_TLV_RW: 262 sock->remote_rw = llcp_tlv_rw(tlv); 263 break; 264 case LLCP_TLV_SN: 265 break; 266 default: 267 pr_err("Invalid gt tlv value 0x%x\n", type); 268 break; 269 } 270 271 offset += length + 2; 272 tlv += length + 2; 273 } 274 275 pr_debug("sock %p rw %d miu %d\n", sock, 276 sock->remote_rw, sock->remote_miu); 277 278 return 0; 279 } 280 281 static struct sk_buff *llcp_add_header(struct sk_buff *pdu, 282 u8 dsap, u8 ssap, u8 ptype) 283 { 284 u8 header[2]; 285 286 pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap); 287 288 header[0] = (u8)((dsap << 2) | (ptype >> 2)); 289 header[1] = (u8)((ptype << 6) | ssap); 290 291 pr_debug("header 0x%x 0x%x\n", header[0], header[1]); 292 293 skb_put_data(pdu, header, LLCP_HEADER_SIZE); 294 295 return pdu; 296 } 297 298 static struct sk_buff *llcp_add_tlv(struct sk_buff *pdu, u8 *tlv, 299 u8 tlv_length) 300 { 301 /* XXX Add an skb length check */ 302 303 if (tlv == NULL) 304 return NULL; 305 306 skb_put_data(pdu, tlv, tlv_length); 307 308 return pdu; 309 } 310 311 static struct sk_buff *llcp_allocate_pdu(struct nfc_llcp_sock *sock, 312 u8 cmd, u16 size) 313 { 314 struct sk_buff *skb; 315 int err; 316 317 if (sock->ssap == 0) 318 return NULL; 319 320 skb = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT, 321 size + LLCP_HEADER_SIZE, &err); 322 if (skb == NULL) { 323 pr_err("Could not allocate PDU\n"); 324 return NULL; 325 } 326 327 skb = llcp_add_header(skb, sock->dsap, sock->ssap, cmd); 328 329 return skb; 330 } 331 332 int nfc_llcp_send_disconnect(struct nfc_llcp_sock *sock) 333 { 334 struct sk_buff *skb; 335 struct nfc_dev *dev; 336 struct nfc_llcp_local *local; 337 338 pr_debug("Sending DISC\n"); 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; 362 363 pr_debug("Sending SYMM\n"); 364 365 local = nfc_llcp_find_local(dev); 366 if (local == NULL) 367 return -ENODEV; 368 369 size += LLCP_HEADER_SIZE; 370 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; 371 372 skb = alloc_skb(size, GFP_KERNEL); 373 if (skb == NULL) 374 return -ENOMEM; 375 376 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE); 377 378 skb = llcp_add_header(skb, 0, 0, LLCP_PDU_SYMM); 379 380 __net_timestamp(skb); 381 382 nfc_llcp_send_to_raw_sock(local, skb, NFC_DIRECTION_TX); 383 384 return nfc_data_exchange(dev, local->target_idx, skb, 385 nfc_llcp_recv, local); 386 } 387 388 int nfc_llcp_send_connect(struct nfc_llcp_sock *sock) 389 { 390 struct nfc_llcp_local *local; 391 struct sk_buff *skb; 392 u8 *service_name_tlv = NULL, service_name_tlv_length; 393 u8 *miux_tlv = NULL, miux_tlv_length; 394 u8 *rw_tlv = NULL, rw_tlv_length, rw; 395 int err; 396 u16 size = 0; 397 __be16 miux; 398 399 pr_debug("Sending CONNECT\n"); 400 401 local = sock->local; 402 if (local == NULL) 403 return -ENODEV; 404 405 if (sock->service_name != NULL) { 406 service_name_tlv = nfc_llcp_build_tlv(LLCP_TLV_SN, 407 sock->service_name, 408 sock->service_name_len, 409 &service_name_tlv_length); 410 if (!service_name_tlv) { 411 err = -ENOMEM; 412 goto error_tlv; 413 } 414 size += service_name_tlv_length; 415 } 416 417 /* If the socket parameters are not set, use the local ones */ 418 miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ? 419 local->miux : sock->miux; 420 rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw; 421 422 miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0, 423 &miux_tlv_length); 424 if (!miux_tlv) { 425 err = -ENOMEM; 426 goto error_tlv; 427 } 428 size += miux_tlv_length; 429 430 rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length); 431 if (!rw_tlv) { 432 err = -ENOMEM; 433 goto error_tlv; 434 } 435 size += rw_tlv_length; 436 437 pr_debug("SKB size %d SN length %zu\n", size, sock->service_name_len); 438 439 skb = llcp_allocate_pdu(sock, LLCP_PDU_CONNECT, size); 440 if (skb == NULL) { 441 err = -ENOMEM; 442 goto error_tlv; 443 } 444 445 llcp_add_tlv(skb, service_name_tlv, service_name_tlv_length); 446 llcp_add_tlv(skb, miux_tlv, miux_tlv_length); 447 llcp_add_tlv(skb, rw_tlv, rw_tlv_length); 448 449 skb_queue_tail(&local->tx_queue, skb); 450 451 err = 0; 452 453 error_tlv: 454 if (err) 455 pr_err("error %d\n", err); 456 457 kfree(service_name_tlv); 458 kfree(miux_tlv); 459 kfree(rw_tlv); 460 461 return err; 462 } 463 464 int nfc_llcp_send_cc(struct nfc_llcp_sock *sock) 465 { 466 struct nfc_llcp_local *local; 467 struct sk_buff *skb; 468 u8 *miux_tlv = NULL, miux_tlv_length; 469 u8 *rw_tlv = NULL, rw_tlv_length, rw; 470 int err; 471 u16 size = 0; 472 __be16 miux; 473 474 pr_debug("Sending CC\n"); 475 476 local = sock->local; 477 if (local == NULL) 478 return -ENODEV; 479 480 /* If the socket parameters are not set, use the local ones */ 481 miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ? 482 local->miux : sock->miux; 483 rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw; 484 485 miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0, 486 &miux_tlv_length); 487 if (!miux_tlv) { 488 err = -ENOMEM; 489 goto error_tlv; 490 } 491 size += miux_tlv_length; 492 493 rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length); 494 if (!rw_tlv) { 495 err = -ENOMEM; 496 goto error_tlv; 497 } 498 size += rw_tlv_length; 499 500 skb = llcp_allocate_pdu(sock, LLCP_PDU_CC, size); 501 if (skb == NULL) { 502 err = -ENOMEM; 503 goto error_tlv; 504 } 505 506 llcp_add_tlv(skb, miux_tlv, miux_tlv_length); 507 llcp_add_tlv(skb, rw_tlv, rw_tlv_length); 508 509 skb_queue_tail(&local->tx_queue, skb); 510 511 err = 0; 512 513 error_tlv: 514 if (err) 515 pr_err("error %d\n", err); 516 517 kfree(miux_tlv); 518 kfree(rw_tlv); 519 520 return err; 521 } 522 523 static struct sk_buff *nfc_llcp_allocate_snl(struct nfc_llcp_local *local, 524 size_t tlv_length) 525 { 526 struct sk_buff *skb; 527 struct nfc_dev *dev; 528 u16 size = 0; 529 530 if (local == NULL) 531 return ERR_PTR(-ENODEV); 532 533 dev = local->dev; 534 if (dev == NULL) 535 return ERR_PTR(-ENODEV); 536 537 size += LLCP_HEADER_SIZE; 538 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; 539 size += tlv_length; 540 541 skb = alloc_skb(size, GFP_KERNEL); 542 if (skb == NULL) 543 return ERR_PTR(-ENOMEM); 544 545 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE); 546 547 skb = llcp_add_header(skb, LLCP_SAP_SDP, LLCP_SAP_SDP, LLCP_PDU_SNL); 548 549 return skb; 550 } 551 552 int nfc_llcp_send_snl_sdres(struct nfc_llcp_local *local, 553 struct hlist_head *tlv_list, size_t tlvs_len) 554 { 555 struct nfc_llcp_sdp_tlv *sdp; 556 struct hlist_node *n; 557 struct sk_buff *skb; 558 559 skb = nfc_llcp_allocate_snl(local, tlvs_len); 560 if (IS_ERR(skb)) 561 return PTR_ERR(skb); 562 563 hlist_for_each_entry_safe(sdp, n, tlv_list, node) { 564 skb_put_data(skb, sdp->tlv, sdp->tlv_len); 565 566 hlist_del(&sdp->node); 567 568 nfc_llcp_free_sdp_tlv(sdp); 569 } 570 571 skb_queue_tail(&local->tx_queue, skb); 572 573 return 0; 574 } 575 576 int nfc_llcp_send_snl_sdreq(struct nfc_llcp_local *local, 577 struct hlist_head *tlv_list, size_t tlvs_len) 578 { 579 struct nfc_llcp_sdp_tlv *sdreq; 580 struct hlist_node *n; 581 struct sk_buff *skb; 582 583 skb = nfc_llcp_allocate_snl(local, tlvs_len); 584 if (IS_ERR(skb)) 585 return PTR_ERR(skb); 586 587 mutex_lock(&local->sdreq_lock); 588 589 if (hlist_empty(&local->pending_sdreqs)) 590 mod_timer(&local->sdreq_timer, 591 jiffies + msecs_to_jiffies(3 * local->remote_lto)); 592 593 hlist_for_each_entry_safe(sdreq, n, tlv_list, node) { 594 pr_debug("tid %d for %s\n", sdreq->tid, sdreq->uri); 595 596 skb_put_data(skb, sdreq->tlv, sdreq->tlv_len); 597 598 hlist_del(&sdreq->node); 599 600 hlist_add_head(&sdreq->node, &local->pending_sdreqs); 601 } 602 603 mutex_unlock(&local->sdreq_lock); 604 605 skb_queue_tail(&local->tx_queue, skb); 606 607 return 0; 608 } 609 610 int nfc_llcp_send_dm(struct nfc_llcp_local *local, u8 ssap, u8 dsap, u8 reason) 611 { 612 struct sk_buff *skb; 613 struct nfc_dev *dev; 614 u16 size = 1; /* Reason code */ 615 616 pr_debug("Sending DM reason 0x%x\n", reason); 617 618 if (local == NULL) 619 return -ENODEV; 620 621 dev = local->dev; 622 if (dev == NULL) 623 return -ENODEV; 624 625 size += LLCP_HEADER_SIZE; 626 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; 627 628 skb = alloc_skb(size, GFP_KERNEL); 629 if (skb == NULL) 630 return -ENOMEM; 631 632 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE); 633 634 skb = llcp_add_header(skb, dsap, ssap, LLCP_PDU_DM); 635 636 skb_put_data(skb, &reason, 1); 637 638 skb_queue_head(&local->tx_queue, skb); 639 640 return 0; 641 } 642 643 int nfc_llcp_send_i_frame(struct nfc_llcp_sock *sock, 644 struct msghdr *msg, size_t len) 645 { 646 struct sk_buff *pdu; 647 struct sock *sk = &sock->sk; 648 struct nfc_llcp_local *local; 649 size_t frag_len = 0, remaining_len; 650 u8 *msg_data, *msg_ptr; 651 u16 remote_miu; 652 653 pr_debug("Send I frame len %zd\n", len); 654 655 local = sock->local; 656 if (local == NULL) 657 return -ENODEV; 658 659 /* Remote is ready but has not acknowledged our frames */ 660 if((sock->remote_ready && 661 skb_queue_len(&sock->tx_pending_queue) >= sock->remote_rw && 662 skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) { 663 pr_err("Pending queue is full %d frames\n", 664 skb_queue_len(&sock->tx_pending_queue)); 665 return -ENOBUFS; 666 } 667 668 /* Remote is not ready and we've been queueing enough frames */ 669 if ((!sock->remote_ready && 670 skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) { 671 pr_err("Tx queue is full %d frames\n", 672 skb_queue_len(&sock->tx_queue)); 673 return -ENOBUFS; 674 } 675 676 msg_data = kmalloc(len, GFP_USER | __GFP_NOWARN); 677 if (msg_data == NULL) 678 return -ENOMEM; 679 680 if (memcpy_from_msg(msg_data, msg, len)) { 681 kfree(msg_data); 682 return -EFAULT; 683 } 684 685 remaining_len = len; 686 msg_ptr = msg_data; 687 688 do { 689 remote_miu = sock->remote_miu > LLCP_MAX_MIU ? 690 LLCP_DEFAULT_MIU : sock->remote_miu; 691 692 frag_len = min_t(size_t, remote_miu, remaining_len); 693 694 pr_debug("Fragment %zd bytes remaining %zd", 695 frag_len, remaining_len); 696 697 pdu = llcp_allocate_pdu(sock, LLCP_PDU_I, 698 frag_len + LLCP_SEQUENCE_SIZE); 699 if (pdu == NULL) { 700 kfree(msg_data); 701 return -ENOMEM; 702 } 703 704 skb_put(pdu, LLCP_SEQUENCE_SIZE); 705 706 if (likely(frag_len > 0)) 707 skb_put_data(pdu, msg_ptr, frag_len); 708 709 skb_queue_tail(&sock->tx_queue, pdu); 710 711 lock_sock(sk); 712 713 nfc_llcp_queue_i_frames(sock); 714 715 release_sock(sk); 716 717 remaining_len -= frag_len; 718 msg_ptr += frag_len; 719 } while (remaining_len > 0); 720 721 kfree(msg_data); 722 723 return len; 724 } 725 726 int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, u8 ssap, u8 dsap, 727 struct msghdr *msg, size_t len) 728 { 729 struct sk_buff *pdu; 730 struct nfc_llcp_local *local; 731 size_t frag_len = 0, remaining_len; 732 u8 *msg_ptr, *msg_data; 733 u16 remote_miu; 734 int err; 735 736 pr_debug("Send UI frame len %zd\n", len); 737 738 local = sock->local; 739 if (local == NULL) 740 return -ENODEV; 741 742 msg_data = kmalloc(len, GFP_USER | __GFP_NOWARN); 743 if (msg_data == NULL) 744 return -ENOMEM; 745 746 if (memcpy_from_msg(msg_data, msg, len)) { 747 kfree(msg_data); 748 return -EFAULT; 749 } 750 751 remaining_len = len; 752 msg_ptr = msg_data; 753 754 do { 755 remote_miu = sock->remote_miu > LLCP_MAX_MIU ? 756 local->remote_miu : sock->remote_miu; 757 758 frag_len = min_t(size_t, remote_miu, remaining_len); 759 760 pr_debug("Fragment %zd bytes remaining %zd", 761 frag_len, remaining_len); 762 763 pdu = nfc_alloc_send_skb(sock->dev, &sock->sk, 0, 764 frag_len + LLCP_HEADER_SIZE, &err); 765 if (pdu == NULL) { 766 pr_err("Could not allocate PDU (error=%d)\n", err); 767 len -= remaining_len; 768 if (len == 0) 769 len = err; 770 break; 771 } 772 773 pdu = llcp_add_header(pdu, dsap, ssap, LLCP_PDU_UI); 774 775 if (likely(frag_len > 0)) 776 skb_put_data(pdu, msg_ptr, frag_len); 777 778 /* No need to check for the peer RW for UI frames */ 779 skb_queue_tail(&local->tx_queue, pdu); 780 781 remaining_len -= frag_len; 782 msg_ptr += frag_len; 783 } while (remaining_len > 0); 784 785 kfree(msg_data); 786 787 return len; 788 } 789 790 int nfc_llcp_send_rr(struct nfc_llcp_sock *sock) 791 { 792 struct sk_buff *skb; 793 struct nfc_llcp_local *local; 794 795 pr_debug("Send rr nr %d\n", sock->recv_n); 796 797 local = sock->local; 798 if (local == NULL) 799 return -ENODEV; 800 801 skb = llcp_allocate_pdu(sock, LLCP_PDU_RR, LLCP_SEQUENCE_SIZE); 802 if (skb == NULL) 803 return -ENOMEM; 804 805 skb_put(skb, LLCP_SEQUENCE_SIZE); 806 807 skb->data[2] = sock->recv_n; 808 809 skb_queue_head(&local->tx_queue, skb); 810 811 return 0; 812 } 813