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->tlv_len is u8, takes uri_len, + 3 for header, + 1 for NULL */ 153 if (WARN_ON_ONCE(uri_len > U8_MAX - 4)) 154 return NULL; 155 156 sdreq = kzalloc(sizeof(struct nfc_llcp_sdp_tlv), GFP_KERNEL); 157 if (sdreq == NULL) 158 return NULL; 159 160 sdreq->tlv_len = uri_len + 3; 161 162 if (uri[uri_len - 1] == 0) 163 sdreq->tlv_len--; 164 165 sdreq->tlv = kzalloc(sdreq->tlv_len + 1, GFP_KERNEL); 166 if (sdreq->tlv == NULL) { 167 kfree(sdreq); 168 return NULL; 169 } 170 171 sdreq->tlv[0] = LLCP_TLV_SDREQ; 172 sdreq->tlv[1] = sdreq->tlv_len - 2; 173 sdreq->tlv[2] = tid; 174 175 sdreq->tid = tid; 176 sdreq->uri = sdreq->tlv + 3; 177 memcpy(sdreq->uri, uri, uri_len); 178 179 sdreq->time = jiffies; 180 181 INIT_HLIST_NODE(&sdreq->node); 182 183 return sdreq; 184 } 185 186 void nfc_llcp_free_sdp_tlv(struct nfc_llcp_sdp_tlv *sdp) 187 { 188 kfree(sdp->tlv); 189 kfree(sdp); 190 } 191 192 void nfc_llcp_free_sdp_tlv_list(struct hlist_head *head) 193 { 194 struct nfc_llcp_sdp_tlv *sdp; 195 struct hlist_node *n; 196 197 hlist_for_each_entry_safe(sdp, n, head, node) { 198 hlist_del(&sdp->node); 199 200 nfc_llcp_free_sdp_tlv(sdp); 201 } 202 } 203 204 int nfc_llcp_parse_gb_tlv(struct nfc_llcp_local *local, 205 u8 *tlv_array, u16 tlv_array_len) 206 { 207 u8 *tlv = tlv_array, type, length, offset = 0; 208 209 pr_debug("TLV array length %d\n", tlv_array_len); 210 211 if (local == NULL) 212 return -ENODEV; 213 214 while (offset < tlv_array_len) { 215 type = tlv[0]; 216 length = tlv[1]; 217 218 pr_debug("type 0x%x length %d\n", type, length); 219 220 switch (type) { 221 case LLCP_TLV_VERSION: 222 local->remote_version = llcp_tlv_version(tlv); 223 break; 224 case LLCP_TLV_MIUX: 225 local->remote_miu = llcp_tlv_miux(tlv) + 128; 226 break; 227 case LLCP_TLV_WKS: 228 local->remote_wks = llcp_tlv_wks(tlv); 229 break; 230 case LLCP_TLV_LTO: 231 local->remote_lto = llcp_tlv_lto(tlv) * 10; 232 break; 233 case LLCP_TLV_OPT: 234 local->remote_opt = llcp_tlv_opt(tlv); 235 break; 236 default: 237 pr_err("Invalid gt tlv value 0x%x\n", type); 238 break; 239 } 240 241 offset += length + 2; 242 tlv += length + 2; 243 } 244 245 pr_debug("version 0x%x miu %d lto %d opt 0x%x wks 0x%x\n", 246 local->remote_version, local->remote_miu, 247 local->remote_lto, local->remote_opt, 248 local->remote_wks); 249 250 return 0; 251 } 252 253 int nfc_llcp_parse_connection_tlv(struct nfc_llcp_sock *sock, 254 u8 *tlv_array, u16 tlv_array_len) 255 { 256 u8 *tlv = tlv_array, type, length, offset = 0; 257 258 pr_debug("TLV array length %d\n", tlv_array_len); 259 260 if (sock == NULL) 261 return -ENOTCONN; 262 263 while (offset < tlv_array_len) { 264 type = tlv[0]; 265 length = tlv[1]; 266 267 pr_debug("type 0x%x length %d\n", type, length); 268 269 switch (type) { 270 case LLCP_TLV_MIUX: 271 sock->remote_miu = llcp_tlv_miux(tlv) + 128; 272 break; 273 case LLCP_TLV_RW: 274 sock->remote_rw = llcp_tlv_rw(tlv); 275 break; 276 case LLCP_TLV_SN: 277 break; 278 default: 279 pr_err("Invalid gt tlv value 0x%x\n", type); 280 break; 281 } 282 283 offset += length + 2; 284 tlv += length + 2; 285 } 286 287 pr_debug("sock %p rw %d miu %d\n", sock, 288 sock->remote_rw, sock->remote_miu); 289 290 return 0; 291 } 292 293 static struct sk_buff *llcp_add_header(struct sk_buff *pdu, 294 u8 dsap, u8 ssap, u8 ptype) 295 { 296 u8 header[2]; 297 298 pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap); 299 300 header[0] = (u8)((dsap << 2) | (ptype >> 2)); 301 header[1] = (u8)((ptype << 6) | ssap); 302 303 pr_debug("header 0x%x 0x%x\n", header[0], header[1]); 304 305 skb_put_data(pdu, header, LLCP_HEADER_SIZE); 306 307 return pdu; 308 } 309 310 static struct sk_buff *llcp_add_tlv(struct sk_buff *pdu, u8 *tlv, 311 u8 tlv_length) 312 { 313 /* XXX Add an skb length check */ 314 315 if (tlv == NULL) 316 return NULL; 317 318 skb_put_data(pdu, tlv, tlv_length); 319 320 return pdu; 321 } 322 323 static struct sk_buff *llcp_allocate_pdu(struct nfc_llcp_sock *sock, 324 u8 cmd, u16 size) 325 { 326 struct sk_buff *skb; 327 int err; 328 329 if (sock->ssap == 0) 330 return NULL; 331 332 skb = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT, 333 size + LLCP_HEADER_SIZE, &err); 334 if (skb == NULL) { 335 pr_err("Could not allocate PDU\n"); 336 return NULL; 337 } 338 339 skb = llcp_add_header(skb, sock->dsap, sock->ssap, cmd); 340 341 return skb; 342 } 343 344 int nfc_llcp_send_disconnect(struct nfc_llcp_sock *sock) 345 { 346 struct sk_buff *skb; 347 struct nfc_dev *dev; 348 struct nfc_llcp_local *local; 349 350 pr_debug("Sending DISC\n"); 351 352 local = sock->local; 353 if (local == NULL) 354 return -ENODEV; 355 356 dev = sock->dev; 357 if (dev == NULL) 358 return -ENODEV; 359 360 skb = llcp_allocate_pdu(sock, LLCP_PDU_DISC, 0); 361 if (skb == NULL) 362 return -ENOMEM; 363 364 skb_queue_tail(&local->tx_queue, skb); 365 366 return 0; 367 } 368 369 int nfc_llcp_send_symm(struct nfc_dev *dev) 370 { 371 struct sk_buff *skb; 372 struct nfc_llcp_local *local; 373 u16 size = 0; 374 375 pr_debug("Sending SYMM\n"); 376 377 local = nfc_llcp_find_local(dev); 378 if (local == NULL) 379 return -ENODEV; 380 381 size += LLCP_HEADER_SIZE; 382 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; 383 384 skb = alloc_skb(size, GFP_KERNEL); 385 if (skb == NULL) 386 return -ENOMEM; 387 388 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE); 389 390 skb = llcp_add_header(skb, 0, 0, LLCP_PDU_SYMM); 391 392 __net_timestamp(skb); 393 394 nfc_llcp_send_to_raw_sock(local, skb, NFC_DIRECTION_TX); 395 396 return nfc_data_exchange(dev, local->target_idx, skb, 397 nfc_llcp_recv, local); 398 } 399 400 int nfc_llcp_send_connect(struct nfc_llcp_sock *sock) 401 { 402 struct nfc_llcp_local *local; 403 struct sk_buff *skb; 404 u8 *service_name_tlv = NULL, service_name_tlv_length; 405 u8 *miux_tlv = NULL, miux_tlv_length; 406 u8 *rw_tlv = NULL, rw_tlv_length, rw; 407 int err; 408 u16 size = 0; 409 __be16 miux; 410 411 pr_debug("Sending CONNECT\n"); 412 413 local = sock->local; 414 if (local == NULL) 415 return -ENODEV; 416 417 if (sock->service_name != NULL) { 418 service_name_tlv = nfc_llcp_build_tlv(LLCP_TLV_SN, 419 sock->service_name, 420 sock->service_name_len, 421 &service_name_tlv_length); 422 size += service_name_tlv_length; 423 } 424 425 /* If the socket parameters are not set, use the local ones */ 426 miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ? 427 local->miux : sock->miux; 428 rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw; 429 430 miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0, 431 &miux_tlv_length); 432 size += miux_tlv_length; 433 434 rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length); 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 size += miux_tlv_length; 488 489 rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length); 490 size += rw_tlv_length; 491 492 skb = llcp_allocate_pdu(sock, LLCP_PDU_CC, size); 493 if (skb == NULL) { 494 err = -ENOMEM; 495 goto error_tlv; 496 } 497 498 llcp_add_tlv(skb, miux_tlv, miux_tlv_length); 499 llcp_add_tlv(skb, rw_tlv, rw_tlv_length); 500 501 skb_queue_tail(&local->tx_queue, skb); 502 503 err = 0; 504 505 error_tlv: 506 if (err) 507 pr_err("error %d\n", err); 508 509 kfree(miux_tlv); 510 kfree(rw_tlv); 511 512 return err; 513 } 514 515 static struct sk_buff *nfc_llcp_allocate_snl(struct nfc_llcp_local *local, 516 size_t tlv_length) 517 { 518 struct sk_buff *skb; 519 struct nfc_dev *dev; 520 u16 size = 0; 521 522 if (local == NULL) 523 return ERR_PTR(-ENODEV); 524 525 dev = local->dev; 526 if (dev == NULL) 527 return ERR_PTR(-ENODEV); 528 529 size += LLCP_HEADER_SIZE; 530 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; 531 size += tlv_length; 532 533 skb = alloc_skb(size, GFP_KERNEL); 534 if (skb == NULL) 535 return ERR_PTR(-ENOMEM); 536 537 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE); 538 539 skb = llcp_add_header(skb, LLCP_SAP_SDP, LLCP_SAP_SDP, LLCP_PDU_SNL); 540 541 return skb; 542 } 543 544 int nfc_llcp_send_snl_sdres(struct nfc_llcp_local *local, 545 struct hlist_head *tlv_list, size_t tlvs_len) 546 { 547 struct nfc_llcp_sdp_tlv *sdp; 548 struct hlist_node *n; 549 struct sk_buff *skb; 550 551 skb = nfc_llcp_allocate_snl(local, tlvs_len); 552 if (IS_ERR(skb)) 553 return PTR_ERR(skb); 554 555 hlist_for_each_entry_safe(sdp, n, tlv_list, node) { 556 skb_put_data(skb, sdp->tlv, sdp->tlv_len); 557 558 hlist_del(&sdp->node); 559 560 nfc_llcp_free_sdp_tlv(sdp); 561 } 562 563 skb_queue_tail(&local->tx_queue, skb); 564 565 return 0; 566 } 567 568 int nfc_llcp_send_snl_sdreq(struct nfc_llcp_local *local, 569 struct hlist_head *tlv_list, size_t tlvs_len) 570 { 571 struct nfc_llcp_sdp_tlv *sdreq; 572 struct hlist_node *n; 573 struct sk_buff *skb; 574 575 skb = nfc_llcp_allocate_snl(local, tlvs_len); 576 if (IS_ERR(skb)) 577 return PTR_ERR(skb); 578 579 mutex_lock(&local->sdreq_lock); 580 581 if (hlist_empty(&local->pending_sdreqs)) 582 mod_timer(&local->sdreq_timer, 583 jiffies + msecs_to_jiffies(3 * local->remote_lto)); 584 585 hlist_for_each_entry_safe(sdreq, n, tlv_list, node) { 586 pr_debug("tid %d for %s\n", sdreq->tid, sdreq->uri); 587 588 skb_put_data(skb, sdreq->tlv, sdreq->tlv_len); 589 590 hlist_del(&sdreq->node); 591 592 hlist_add_head(&sdreq->node, &local->pending_sdreqs); 593 } 594 595 mutex_unlock(&local->sdreq_lock); 596 597 skb_queue_tail(&local->tx_queue, skb); 598 599 return 0; 600 } 601 602 int nfc_llcp_send_dm(struct nfc_llcp_local *local, u8 ssap, u8 dsap, u8 reason) 603 { 604 struct sk_buff *skb; 605 struct nfc_dev *dev; 606 u16 size = 1; /* Reason code */ 607 608 pr_debug("Sending DM reason 0x%x\n", reason); 609 610 if (local == NULL) 611 return -ENODEV; 612 613 dev = local->dev; 614 if (dev == NULL) 615 return -ENODEV; 616 617 size += LLCP_HEADER_SIZE; 618 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; 619 620 skb = alloc_skb(size, GFP_KERNEL); 621 if (skb == NULL) 622 return -ENOMEM; 623 624 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE); 625 626 skb = llcp_add_header(skb, dsap, ssap, LLCP_PDU_DM); 627 628 skb_put_data(skb, &reason, 1); 629 630 skb_queue_head(&local->tx_queue, skb); 631 632 return 0; 633 } 634 635 int nfc_llcp_send_i_frame(struct nfc_llcp_sock *sock, 636 struct msghdr *msg, size_t len) 637 { 638 struct sk_buff *pdu; 639 struct sock *sk = &sock->sk; 640 struct nfc_llcp_local *local; 641 size_t frag_len = 0, remaining_len; 642 u8 *msg_data, *msg_ptr; 643 u16 remote_miu; 644 645 pr_debug("Send I frame len %zd\n", len); 646 647 local = sock->local; 648 if (local == NULL) 649 return -ENODEV; 650 651 /* Remote is ready but has not acknowledged our frames */ 652 if((sock->remote_ready && 653 skb_queue_len(&sock->tx_pending_queue) >= sock->remote_rw && 654 skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) { 655 pr_err("Pending queue is full %d frames\n", 656 skb_queue_len(&sock->tx_pending_queue)); 657 return -ENOBUFS; 658 } 659 660 /* Remote is not ready and we've been queueing enough frames */ 661 if ((!sock->remote_ready && 662 skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) { 663 pr_err("Tx queue is full %d frames\n", 664 skb_queue_len(&sock->tx_queue)); 665 return -ENOBUFS; 666 } 667 668 msg_data = kmalloc(len, GFP_USER | __GFP_NOWARN); 669 if (msg_data == NULL) 670 return -ENOMEM; 671 672 if (memcpy_from_msg(msg_data, msg, len)) { 673 kfree(msg_data); 674 return -EFAULT; 675 } 676 677 remaining_len = len; 678 msg_ptr = msg_data; 679 680 do { 681 remote_miu = sock->remote_miu > LLCP_MAX_MIU ? 682 LLCP_DEFAULT_MIU : sock->remote_miu; 683 684 frag_len = min_t(size_t, remote_miu, remaining_len); 685 686 pr_debug("Fragment %zd bytes remaining %zd", 687 frag_len, remaining_len); 688 689 pdu = llcp_allocate_pdu(sock, LLCP_PDU_I, 690 frag_len + LLCP_SEQUENCE_SIZE); 691 if (pdu == NULL) { 692 kfree(msg_data); 693 return -ENOMEM; 694 } 695 696 skb_put(pdu, LLCP_SEQUENCE_SIZE); 697 698 if (likely(frag_len > 0)) 699 skb_put_data(pdu, msg_ptr, frag_len); 700 701 skb_queue_tail(&sock->tx_queue, pdu); 702 703 lock_sock(sk); 704 705 nfc_llcp_queue_i_frames(sock); 706 707 release_sock(sk); 708 709 remaining_len -= frag_len; 710 msg_ptr += frag_len; 711 } while (remaining_len > 0); 712 713 kfree(msg_data); 714 715 return len; 716 } 717 718 int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, u8 ssap, u8 dsap, 719 struct msghdr *msg, size_t len) 720 { 721 struct sk_buff *pdu; 722 struct nfc_llcp_local *local; 723 size_t frag_len = 0, remaining_len; 724 u8 *msg_ptr, *msg_data; 725 u16 remote_miu; 726 int err; 727 728 pr_debug("Send UI frame len %zd\n", len); 729 730 local = sock->local; 731 if (local == NULL) 732 return -ENODEV; 733 734 msg_data = kmalloc(len, GFP_USER | __GFP_NOWARN); 735 if (msg_data == NULL) 736 return -ENOMEM; 737 738 if (memcpy_from_msg(msg_data, msg, len)) { 739 kfree(msg_data); 740 return -EFAULT; 741 } 742 743 remaining_len = len; 744 msg_ptr = msg_data; 745 746 do { 747 remote_miu = sock->remote_miu > LLCP_MAX_MIU ? 748 local->remote_miu : sock->remote_miu; 749 750 frag_len = min_t(size_t, remote_miu, remaining_len); 751 752 pr_debug("Fragment %zd bytes remaining %zd", 753 frag_len, remaining_len); 754 755 pdu = nfc_alloc_send_skb(sock->dev, &sock->sk, 0, 756 frag_len + LLCP_HEADER_SIZE, &err); 757 if (pdu == NULL) { 758 pr_err("Could not allocate PDU (error=%d)\n", err); 759 len -= remaining_len; 760 if (len == 0) 761 len = err; 762 break; 763 } 764 765 pdu = llcp_add_header(pdu, dsap, ssap, LLCP_PDU_UI); 766 767 if (likely(frag_len > 0)) 768 skb_put_data(pdu, msg_ptr, frag_len); 769 770 /* No need to check for the peer RW for UI frames */ 771 skb_queue_tail(&local->tx_queue, pdu); 772 773 remaining_len -= frag_len; 774 msg_ptr += frag_len; 775 } while (remaining_len > 0); 776 777 kfree(msg_data); 778 779 return len; 780 } 781 782 int nfc_llcp_send_rr(struct nfc_llcp_sock *sock) 783 { 784 struct sk_buff *skb; 785 struct nfc_llcp_local *local; 786 787 pr_debug("Send rr nr %d\n", sock->recv_n); 788 789 local = sock->local; 790 if (local == NULL) 791 return -ENODEV; 792 793 skb = llcp_allocate_pdu(sock, LLCP_PDU_RR, LLCP_SEQUENCE_SIZE); 794 if (skb == NULL) 795 return -ENOMEM; 796 797 skb_put(skb, LLCP_SEQUENCE_SIZE); 798 799 skb->data[2] = sock->recv_n; 800 801 skb_queue_head(&local->tx_queue, skb); 802 803 return 0; 804 } 805