llcp_core.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Copyright (C) 2011  Intel Corporation. All rights reserved.
   4 * Copyright (C) 2014 Marvell International Ltd.
   5 */
   6
   7#define pr_fmt(fmt) "llcp: %s: " fmt, __func__
   8
   9#include <linux/init.h>
  10#include <linux/kernel.h>
  11#include <linux/list.h>
  12#include <linux/nfc.h>
  13
  14#include "nfc.h"
  15#include "llcp.h"
  16
  17static u8 llcp_magic[3] = {0x46, 0x66, 0x6d};
  18
  19static LIST_HEAD(llcp_devices);
  20/* Protects llcp_devices list */
  21static DEFINE_SPINLOCK(llcp_devices_lock);
  22
  23static void nfc_llcp_rx_skb(struct nfc_llcp_local *local, struct sk_buff *skb);
  24
  25void nfc_llcp_sock_link(struct llcp_sock_list *l, struct sock *sk)
  26{
  27	write_lock(&l->lock);
  28	sk_add_node(sk, &l->head);
  29	write_unlock(&l->lock);
  30}
  31
  32void nfc_llcp_sock_unlink(struct llcp_sock_list *l, struct sock *sk)
  33{
  34	write_lock(&l->lock);
  35	sk_del_node_init(sk);
  36	write_unlock(&l->lock);
  37}
  38
  39void nfc_llcp_socket_remote_param_init(struct nfc_llcp_sock *sock)
  40{
  41	sock->remote_rw = LLCP_DEFAULT_RW;
  42	sock->remote_miu = LLCP_MAX_MIU + 1;
  43}
  44
  45static void nfc_llcp_socket_purge(struct nfc_llcp_sock *sock)
  46{
  47	struct nfc_llcp_local *local = sock->local;
  48	struct sk_buff *s, *tmp;
  49
  50	skb_queue_purge(&sock->tx_queue);
  51	skb_queue_purge(&sock->tx_pending_queue);
  52
  53	if (local == NULL)
  54		return;
  55
  56	/* Search for local pending SKBs that are related to this socket */
  57	skb_queue_walk_safe(&local->tx_queue, s, tmp) {
  58		if (s->sk != &sock->sk)
  59			continue;
  60
  61		skb_unlink(s, &local->tx_queue);
  62		kfree_skb(s);
  63	}
  64}
  65
  66static void nfc_llcp_socket_release(struct nfc_llcp_local *local, bool device,
  67				    int err)
  68{
  69	struct sock *sk;
  70	struct hlist_node *tmp;
  71	struct nfc_llcp_sock *llcp_sock;
  72
  73	skb_queue_purge(&local->tx_queue);
  74
  75	write_lock(&local->sockets.lock);
  76
  77	sk_for_each_safe(sk, tmp, &local->sockets.head) {
  78		llcp_sock = nfc_llcp_sock(sk);
  79
  80		bh_lock_sock(sk);
  81
  82		nfc_llcp_socket_purge(llcp_sock);
  83
  84		if (sk->sk_state == LLCP_CONNECTED)
  85			nfc_put_device(llcp_sock->dev);
  86
  87		if (sk->sk_state == LLCP_LISTEN) {
  88			struct nfc_llcp_sock *lsk, *n;
  89			struct sock *accept_sk;
  90
  91			list_for_each_entry_safe(lsk, n,
  92						 &llcp_sock->accept_queue,
  93						 accept_queue) {
  94				accept_sk = &lsk->sk;
  95				bh_lock_sock(accept_sk);
  96
  97				nfc_llcp_accept_unlink(accept_sk);
  98
  99				if (err)
 100					accept_sk->sk_err = err;
 101				accept_sk->sk_state = LLCP_CLOSED;
 102				accept_sk->sk_state_change(sk);
 103
 104				bh_unlock_sock(accept_sk);
 105			}
 106		}
 107
 108		if (err)
 109			sk->sk_err = err;
 110		sk->sk_state = LLCP_CLOSED;
 111		sk->sk_state_change(sk);
 112
 113		bh_unlock_sock(sk);
 114
 115		sk_del_node_init(sk);
 116	}
 117
 118	write_unlock(&local->sockets.lock);
 119
 120	/* If we still have a device, we keep the RAW sockets alive */
 121	if (device == true)
 122		return;
 123
 124	write_lock(&local->raw_sockets.lock);
 125
 126	sk_for_each_safe(sk, tmp, &local->raw_sockets.head) {
 127		llcp_sock = nfc_llcp_sock(sk);
 128
 129		bh_lock_sock(sk);
 130
 131		nfc_llcp_socket_purge(llcp_sock);
 132
 133		if (err)
 134			sk->sk_err = err;
 135		sk->sk_state = LLCP_CLOSED;
 136		sk->sk_state_change(sk);
 137
 138		bh_unlock_sock(sk);
 139
 140		sk_del_node_init(sk);
 141	}
 142
 143	write_unlock(&local->raw_sockets.lock);
 144}
 145
 146static struct nfc_llcp_local *nfc_llcp_local_get(struct nfc_llcp_local *local)
 147{
 148	/* Since using nfc_llcp_local may result in usage of nfc_dev, whenever
 149	 * we hold a reference to local, we also need to hold a reference to
 150	 * the device to avoid UAF.
 151	 */
 152	if (!nfc_get_device(local->dev->idx))
 153		return NULL;
 154
 155	kref_get(&local->ref);
 156
 157	return local;
 158}
 159
 160static void local_cleanup(struct nfc_llcp_local *local)
 161{
 162	nfc_llcp_socket_release(local, false, ENXIO);
 163	timer_delete_sync(&local->link_timer);
 164	skb_queue_purge(&local->tx_queue);
 165	cancel_work_sync(&local->tx_work);
 166	cancel_work_sync(&local->rx_work);
 167	cancel_work_sync(&local->timeout_work);
 168	kfree_skb(local->rx_pending);
 169	local->rx_pending = NULL;
 170	timer_delete_sync(&local->sdreq_timer);
 171	cancel_work_sync(&local->sdreq_timeout_work);
 172	nfc_llcp_free_sdp_tlv_list(&local->pending_sdreqs);
 173}
 174
 175static void local_release(struct kref *ref)
 176{
 177	struct nfc_llcp_local *local;
 178
 179	local = container_of(ref, struct nfc_llcp_local, ref);
 180
 181	local_cleanup(local);
 182	kfree(local);
 183}
 184
 185int nfc_llcp_local_put(struct nfc_llcp_local *local)
 186{
 187	struct nfc_dev *dev;
 188	int ret;
 189
 190	if (local == NULL)
 191		return 0;
 192
 193	dev = local->dev;
 194
 195	ret = kref_put(&local->ref, local_release);
 196	nfc_put_device(dev);
 197
 198	return ret;
 199}
 200
 201static struct nfc_llcp_sock *nfc_llcp_sock_get(struct nfc_llcp_local *local,
 202					       u8 ssap, u8 dsap)
 203{
 204	struct sock *sk;
 205	struct nfc_llcp_sock *llcp_sock, *tmp_sock;
 206
 207	pr_debug("ssap dsap %d %d\n", ssap, dsap);
 208
 209	if (ssap == 0 && dsap == 0)
 210		return NULL;
 211
 212	read_lock(&local->sockets.lock);
 213
 214	llcp_sock = NULL;
 215
 216	sk_for_each(sk, &local->sockets.head) {
 217		tmp_sock = nfc_llcp_sock(sk);
 218
 219		if (tmp_sock->ssap == ssap && tmp_sock->dsap == dsap) {
 220			llcp_sock = tmp_sock;
 221			sock_hold(&llcp_sock->sk);
 222			break;
 223		}
 224	}
 225
 226	read_unlock(&local->sockets.lock);
 227
 228	return llcp_sock;
 229}
 230
 231static void nfc_llcp_sock_put(struct nfc_llcp_sock *sock)
 232{
 233	sock_put(&sock->sk);
 234}
 235
 236static void nfc_llcp_timeout_work(struct work_struct *work)
 237{
 238	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
 239						    timeout_work);
 240
 241	nfc_dep_link_down(local->dev);
 242}
 243
 244static void nfc_llcp_symm_timer(struct timer_list *t)
 245{
 246	struct nfc_llcp_local *local = timer_container_of(local, t,
 247							  link_timer);
 248
 249	pr_err("SYMM timeout\n");
 250
 251	schedule_work(&local->timeout_work);
 252}
 253
 254static void nfc_llcp_sdreq_timeout_work(struct work_struct *work)
 255{
 256	unsigned long time;
 257	HLIST_HEAD(nl_sdres_list);
 258	struct hlist_node *n;
 259	struct nfc_llcp_sdp_tlv *sdp;
 260	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
 261						    sdreq_timeout_work);
 262
 263	mutex_lock(&local->sdreq_lock);
 264
 265	time = jiffies - msecs_to_jiffies(3 * local->remote_lto);
 266
 267	hlist_for_each_entry_safe(sdp, n, &local->pending_sdreqs, node) {
 268		if (time_after(sdp->time, time))
 269			continue;
 270
 271		sdp->sap = LLCP_SDP_UNBOUND;
 272
 273		hlist_del(&sdp->node);
 274
 275		hlist_add_head(&sdp->node, &nl_sdres_list);
 276	}
 277
 278	if (!hlist_empty(&local->pending_sdreqs))
 279		mod_timer(&local->sdreq_timer,
 280			  jiffies + msecs_to_jiffies(3 * local->remote_lto));
 281
 282	mutex_unlock(&local->sdreq_lock);
 283
 284	if (!hlist_empty(&nl_sdres_list))
 285		nfc_genl_llc_send_sdres(local->dev, &nl_sdres_list);
 286}
 287
 288static void nfc_llcp_sdreq_timer(struct timer_list *t)
 289{
 290	struct nfc_llcp_local *local = timer_container_of(local, t,
 291							  sdreq_timer);
 292
 293	schedule_work(&local->sdreq_timeout_work);
 294}
 295
 296struct nfc_llcp_local *nfc_llcp_find_local(struct nfc_dev *dev)
 297{
 298	struct nfc_llcp_local *local;
 299	struct nfc_llcp_local *res = NULL;
 300
 301	spin_lock(&llcp_devices_lock);
 302	list_for_each_entry(local, &llcp_devices, list)
 303		if (local->dev == dev) {
 304			res = nfc_llcp_local_get(local);
 305			break;
 306		}
 307	spin_unlock(&llcp_devices_lock);
 308
 309	return res;
 310}
 311
 312static struct nfc_llcp_local *nfc_llcp_remove_local(struct nfc_dev *dev)
 313{
 314	struct nfc_llcp_local *local, *tmp;
 315
 316	spin_lock(&llcp_devices_lock);
 317	list_for_each_entry_safe(local, tmp, &llcp_devices, list)
 318		if (local->dev == dev) {
 319			spin_lock(&local->tx_queue.lock);
 320			list_del_init(&local->list);
 321			spin_unlock(&local->tx_queue.lock);
 322			spin_unlock(&llcp_devices_lock);
 323			return local;
 324		}
 325	spin_unlock(&llcp_devices_lock);
 326
 327	pr_warn("Shutting down device not found\n");
 328
 329	return NULL;
 330}
 331
 332static char *wks[] = {
 333	NULL,
 334	NULL, /* SDP */
 335	"urn:nfc:sn:ip",
 336	"urn:nfc:sn:obex",
 337	"urn:nfc:sn:snep",
 338};
 339
 340static int nfc_llcp_wks_sap(const char *service_name, size_t service_name_len)
 341{
 342	int sap, num_wks;
 343
 344	pr_debug("%s\n", service_name);
 345
 346	if (service_name == NULL)
 347		return -EINVAL;
 348
 349	num_wks = ARRAY_SIZE(wks);
 350
 351	for (sap = 0; sap < num_wks; sap++) {
 352		if (wks[sap] == NULL)
 353			continue;
 354
 355		if (strncmp(wks[sap], service_name, service_name_len) == 0)
 356			return sap;
 357	}
 358
 359	return -EINVAL;
 360}
 361
 362static
 363struct nfc_llcp_sock *nfc_llcp_sock_from_sn(struct nfc_llcp_local *local,
 364					    const u8 *sn, size_t sn_len,
 365					    bool needref)
 366{
 367	struct sock *sk;
 368	struct nfc_llcp_sock *llcp_sock, *tmp_sock;
 369
 370	pr_debug("sn %zd %p\n", sn_len, sn);
 371
 372	if (sn == NULL || sn_len == 0)
 373		return NULL;
 374
 375	read_lock(&local->sockets.lock);
 376
 377	llcp_sock = NULL;
 378
 379	sk_for_each(sk, &local->sockets.head) {
 380		tmp_sock = nfc_llcp_sock(sk);
 381
 382		pr_debug("llcp sock %p\n", tmp_sock);
 383
 384		if (tmp_sock->sk.sk_type == SOCK_STREAM &&
 385		    tmp_sock->sk.sk_state != LLCP_LISTEN)
 386			continue;
 387
 388		if (tmp_sock->sk.sk_type == SOCK_DGRAM &&
 389		    tmp_sock->sk.sk_state != LLCP_BOUND)
 390			continue;
 391
 392		if (tmp_sock->service_name == NULL ||
 393		    tmp_sock->service_name_len == 0)
 394			continue;
 395
 396		if (tmp_sock->service_name_len != sn_len)
 397			continue;
 398
 399		if (memcmp(sn, tmp_sock->service_name, sn_len) == 0) {
 400			llcp_sock = tmp_sock;
 401			if (needref)
 402				sock_hold(&llcp_sock->sk);
 403			break;
 404		}
 405	}
 406
 407	read_unlock(&local->sockets.lock);
 408
 409	pr_debug("Found llcp sock %p\n", llcp_sock);
 410
 411	return llcp_sock;
 412}
 413
 414u8 nfc_llcp_get_sdp_ssap(struct nfc_llcp_local *local,
 415			 struct nfc_llcp_sock *sock)
 416{
 417	mutex_lock(&local->sdp_lock);
 418
 419	if (sock->service_name != NULL && sock->service_name_len > 0) {
 420		int ssap = nfc_llcp_wks_sap(sock->service_name,
 421					    sock->service_name_len);
 422
 423		if (ssap > 0) {
 424			pr_debug("WKS %d\n", ssap);
 425
 426			/* This is a WKS, let's check if it's free */
 427			if (test_bit(ssap, &local->local_wks)) {
 428				mutex_unlock(&local->sdp_lock);
 429
 430				return LLCP_SAP_MAX;
 431			}
 432
 433			set_bit(ssap, &local->local_wks);
 434			mutex_unlock(&local->sdp_lock);
 435
 436			return ssap;
 437		}
 438
 439		/*
 440		 * Check if there already is a non WKS socket bound
 441		 * to this service name.
 442		 */
 443		if (nfc_llcp_sock_from_sn(local, sock->service_name,
 444					  sock->service_name_len,
 445					  false) != NULL) {
 446			mutex_unlock(&local->sdp_lock);
 447
 448			return LLCP_SAP_MAX;
 449		}
 450
 451		mutex_unlock(&local->sdp_lock);
 452
 453		return LLCP_SDP_UNBOUND;
 454
 455	} else if (sock->ssap != 0 && sock->ssap < LLCP_WKS_NUM_SAP) {
 456		if (!test_bit(sock->ssap, &local->local_wks)) {
 457			set_bit(sock->ssap, &local->local_wks);
 458			mutex_unlock(&local->sdp_lock);
 459
 460			return sock->ssap;
 461		}
 462	}
 463
 464	mutex_unlock(&local->sdp_lock);
 465
 466	return LLCP_SAP_MAX;
 467}
 468
 469u8 nfc_llcp_get_local_ssap(struct nfc_llcp_local *local)
 470{
 471	u8 local_ssap;
 472
 473	mutex_lock(&local->sdp_lock);
 474
 475	local_ssap = find_first_zero_bit(&local->local_sap, LLCP_LOCAL_NUM_SAP);
 476	if (local_ssap == LLCP_LOCAL_NUM_SAP) {
 477		mutex_unlock(&local->sdp_lock);
 478		return LLCP_SAP_MAX;
 479	}
 480
 481	set_bit(local_ssap, &local->local_sap);
 482
 483	mutex_unlock(&local->sdp_lock);
 484
 485	return local_ssap + LLCP_LOCAL_SAP_OFFSET;
 486}
 487
 488void nfc_llcp_put_ssap(struct nfc_llcp_local *local, u8 ssap)
 489{
 490	u8 local_ssap;
 491	unsigned long *sdp;
 492
 493	if (ssap < LLCP_WKS_NUM_SAP) {
 494		local_ssap = ssap;
 495		sdp = &local->local_wks;
 496	} else if (ssap < LLCP_LOCAL_NUM_SAP) {
 497		atomic_t *client_cnt;
 498
 499		local_ssap = ssap - LLCP_WKS_NUM_SAP;
 500		sdp = &local->local_sdp;
 501		client_cnt = &local->local_sdp_cnt[local_ssap];
 502
 503		pr_debug("%d clients\n", atomic_read(client_cnt));
 504
 505		mutex_lock(&local->sdp_lock);
 506
 507		if (atomic_dec_and_test(client_cnt)) {
 508			struct nfc_llcp_sock *l_sock;
 509
 510			pr_debug("No more clients for SAP %d\n", ssap);
 511
 512			clear_bit(local_ssap, sdp);
 513
 514			/* Find the listening sock and set it back to UNBOUND */
 515			l_sock = nfc_llcp_sock_get(local, ssap, LLCP_SAP_SDP);
 516			if (l_sock) {
 517				l_sock->ssap = LLCP_SDP_UNBOUND;
 518				nfc_llcp_sock_put(l_sock);
 519			}
 520		}
 521
 522		mutex_unlock(&local->sdp_lock);
 523
 524		return;
 525	} else if (ssap < LLCP_MAX_SAP) {
 526		local_ssap = ssap - LLCP_LOCAL_NUM_SAP;
 527		sdp = &local->local_sap;
 528	} else {
 529		return;
 530	}
 531
 532	mutex_lock(&local->sdp_lock);
 533
 534	clear_bit(local_ssap, sdp);
 535
 536	mutex_unlock(&local->sdp_lock);
 537}
 538
 539static u8 nfc_llcp_reserve_sdp_ssap(struct nfc_llcp_local *local)
 540{
 541	u8 ssap;
 542
 543	mutex_lock(&local->sdp_lock);
 544
 545	ssap = find_first_zero_bit(&local->local_sdp, LLCP_SDP_NUM_SAP);
 546	if (ssap == LLCP_SDP_NUM_SAP) {
 547		mutex_unlock(&local->sdp_lock);
 548
 549		return LLCP_SAP_MAX;
 550	}
 551
 552	pr_debug("SDP ssap %d\n", LLCP_WKS_NUM_SAP + ssap);
 553
 554	set_bit(ssap, &local->local_sdp);
 555
 556	mutex_unlock(&local->sdp_lock);
 557
 558	return LLCP_WKS_NUM_SAP + ssap;
 559}
 560
 561static int nfc_llcp_build_gb(struct nfc_llcp_local *local)
 562{
 563	u8 *gb_cur, version, version_length;
 564	u8 lto_length, wks_length, miux_length;
 565	const u8 *version_tlv = NULL, *lto_tlv = NULL,
 566	   *wks_tlv = NULL, *miux_tlv = NULL;
 567	__be16 wks = cpu_to_be16(local->local_wks);
 568	u8 gb_len = 0;
 569	int ret = 0;
 570
 571	version = LLCP_VERSION_11;
 572	version_tlv = nfc_llcp_build_tlv(LLCP_TLV_VERSION, &version,
 573					 1, &version_length);
 574	if (!version_tlv) {
 575		ret = -ENOMEM;
 576		goto out;
 577	}
 578	gb_len += version_length;
 579
 580	lto_tlv = nfc_llcp_build_tlv(LLCP_TLV_LTO, &local->lto, 1, &lto_length);
 581	if (!lto_tlv) {
 582		ret = -ENOMEM;
 583		goto out;
 584	}
 585	gb_len += lto_length;
 586
 587	pr_debug("Local wks 0x%lx\n", local->local_wks);
 588	wks_tlv = nfc_llcp_build_tlv(LLCP_TLV_WKS, (u8 *)&wks, 2, &wks_length);
 589	if (!wks_tlv) {
 590		ret = -ENOMEM;
 591		goto out;
 592	}
 593	gb_len += wks_length;
 594
 595	miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&local->miux, 0,
 596				      &miux_length);
 597	if (!miux_tlv) {
 598		ret = -ENOMEM;
 599		goto out;
 600	}
 601	gb_len += miux_length;
 602
 603	gb_len += ARRAY_SIZE(llcp_magic);
 604
 605	if (gb_len > NFC_MAX_GT_LEN) {
 606		ret = -EINVAL;
 607		goto out;
 608	}
 609
 610	gb_cur = local->gb;
 611
 612	memcpy(gb_cur, llcp_magic, ARRAY_SIZE(llcp_magic));
 613	gb_cur += ARRAY_SIZE(llcp_magic);
 614
 615	memcpy(gb_cur, version_tlv, version_length);
 616	gb_cur += version_length;
 617
 618	memcpy(gb_cur, lto_tlv, lto_length);
 619	gb_cur += lto_length;
 620
 621	memcpy(gb_cur, wks_tlv, wks_length);
 622	gb_cur += wks_length;
 623
 624	memcpy(gb_cur, miux_tlv, miux_length);
 625	gb_cur += miux_length;
 626
 627	local->gb_len = gb_len;
 628
 629out:
 630	kfree(version_tlv);
 631	kfree(lto_tlv);
 632	kfree(wks_tlv);
 633	kfree(miux_tlv);
 634
 635	return ret;
 636}
 637
 638u8 *nfc_llcp_general_bytes(struct nfc_dev *dev, size_t *general_bytes_len)
 639{
 640	struct nfc_llcp_local *local;
 641
 642	local = nfc_llcp_find_local(dev);
 643	if (local == NULL) {
 644		*general_bytes_len = 0;
 645		return NULL;
 646	}
 647
 648	nfc_llcp_build_gb(local);
 649
 650	*general_bytes_len = local->gb_len;
 651
 652	nfc_llcp_local_put(local);
 653
 654	return local->gb;
 655}
 656
 657int nfc_llcp_set_remote_gb(struct nfc_dev *dev, const u8 *gb, u8 gb_len)
 658{
 659	struct nfc_llcp_local *local;
 660	int err;
 661
 662	if (gb_len < 3 || gb_len > NFC_MAX_GT_LEN)
 663		return -EINVAL;
 664
 665	local = nfc_llcp_find_local(dev);
 666	if (local == NULL) {
 667		pr_err("No LLCP device\n");
 668		return -ENODEV;
 669	}
 670
 671	memset(local->remote_gb, 0, NFC_MAX_GT_LEN);
 672	memcpy(local->remote_gb, gb, gb_len);
 673	local->remote_gb_len = gb_len;
 674
 675	if (memcmp(local->remote_gb, llcp_magic, 3)) {
 676		pr_err("MAC does not support LLCP\n");
 677		err = -EINVAL;
 678		goto out;
 679	}
 680
 681	err = nfc_llcp_parse_gb_tlv(local,
 682				     &local->remote_gb[3],
 683				     local->remote_gb_len - 3);
 684out:
 685	nfc_llcp_local_put(local);
 686	return err;
 687}
 688
 689static u8 nfc_llcp_dsap(const struct sk_buff *pdu)
 690{
 691	return (pdu->data[0] & 0xfc) >> 2;
 692}
 693
 694static u8 nfc_llcp_ptype(const struct sk_buff *pdu)
 695{
 696	return ((pdu->data[0] & 0x03) << 2) | ((pdu->data[1] & 0xc0) >> 6);
 697}
 698
 699static u8 nfc_llcp_ssap(const struct sk_buff *pdu)
 700{
 701	return pdu->data[1] & 0x3f;
 702}
 703
 704static u8 nfc_llcp_ns(const struct sk_buff *pdu)
 705{
 706	return pdu->data[2] >> 4;
 707}
 708
 709static u8 nfc_llcp_nr(const struct sk_buff *pdu)
 710{
 711	return pdu->data[2] & 0xf;
 712}
 713
 714static void nfc_llcp_set_nrns(struct nfc_llcp_sock *sock, struct sk_buff *pdu)
 715{
 716	pdu->data[2] = (sock->send_n << 4) | (sock->recv_n);
 717	sock->send_n = (sock->send_n + 1) % 16;
 718	sock->recv_ack_n = (sock->recv_n - 1) % 16;
 719}
 720
 721void nfc_llcp_send_to_raw_sock(struct nfc_llcp_local *local,
 722			       struct sk_buff *skb, u8 direction)
 723{
 724	struct sk_buff *skb_copy = NULL, *nskb;
 725	struct sock *sk;
 726	u8 *data;
 727
 728	read_lock(&local->raw_sockets.lock);
 729
 730	sk_for_each(sk, &local->raw_sockets.head) {
 731		if (sk->sk_state != LLCP_BOUND)
 732			continue;
 733
 734		if (skb_copy == NULL) {
 735			skb_copy = __pskb_copy_fclone(skb, NFC_RAW_HEADER_SIZE,
 736						      GFP_ATOMIC, true);
 737
 738			if (skb_copy == NULL)
 739				continue;
 740
 741			data = skb_push(skb_copy, NFC_RAW_HEADER_SIZE);
 742
 743			data[0] = local->dev ? local->dev->idx : 0xFF;
 744			data[1] = direction & 0x01;
 745			data[1] |= (RAW_PAYLOAD_LLCP << 1);
 746		}
 747
 748		nskb = skb_clone(skb_copy, GFP_ATOMIC);
 749		if (!nskb)
 750			continue;
 751
 752		if (sock_queue_rcv_skb(sk, nskb))
 753			kfree_skb(nskb);
 754	}
 755
 756	read_unlock(&local->raw_sockets.lock);
 757
 758	kfree_skb(skb_copy);
 759}
 760
 761static void nfc_llcp_tx_work(struct work_struct *work)
 762{
 763	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
 764						    tx_work);
 765	struct sk_buff *skb;
 766	struct sock *sk;
 767	struct nfc_llcp_sock *llcp_sock;
 768
 769	skb = skb_dequeue(&local->tx_queue);
 770	if (skb != NULL) {
 771		sk = skb->sk;
 772		llcp_sock = nfc_llcp_sock(sk);
 773
 774		if (llcp_sock == NULL && nfc_llcp_ptype(skb) == LLCP_PDU_I) {
 775			kfree_skb(skb);
 776			nfc_llcp_send_symm(local->dev);
 777		} else if (llcp_sock && !llcp_sock->remote_ready) {
 778			skb_queue_head(&local->tx_queue, skb);
 779			nfc_llcp_send_symm(local->dev);
 780		} else {
 781			struct sk_buff *copy_skb = NULL;
 782			u8 ptype = nfc_llcp_ptype(skb);
 783			int ret;
 784
 785			pr_debug("Sending pending skb\n");
 786			print_hex_dump_debug("LLCP Tx: ", DUMP_PREFIX_OFFSET,
 787					     16, 1, skb->data, skb->len, true);
 788
 789			if (ptype == LLCP_PDU_I)
 790				copy_skb = skb_copy(skb, GFP_ATOMIC);
 791
 792			__net_timestamp(skb);
 793
 794			nfc_llcp_send_to_raw_sock(local, skb,
 795						  NFC_DIRECTION_TX);
 796
 797			ret = nfc_data_exchange(local->dev, local->target_idx,
 798						skb, nfc_llcp_recv, local);
 799
 800			if (ret) {
 801				kfree_skb(copy_skb);
 802				goto out;
 803			}
 804
 805			if (ptype == LLCP_PDU_I && copy_skb)
 806				skb_queue_tail(&llcp_sock->tx_pending_queue,
 807					       copy_skb);
 808		}
 809	} else {
 810		nfc_llcp_send_symm(local->dev);
 811	}
 812
 813out:
 814	mod_timer(&local->link_timer,
 815		  jiffies + msecs_to_jiffies(2 * local->remote_lto));
 816}
 817
 818static struct nfc_llcp_sock *nfc_llcp_connecting_sock_get(struct nfc_llcp_local *local,
 819							  u8 ssap)
 820{
 821	struct sock *sk;
 822	struct nfc_llcp_sock *llcp_sock;
 823
 824	read_lock(&local->connecting_sockets.lock);
 825
 826	sk_for_each(sk, &local->connecting_sockets.head) {
 827		llcp_sock = nfc_llcp_sock(sk);
 828
 829		if (llcp_sock->ssap == ssap) {
 830			sock_hold(&llcp_sock->sk);
 831			goto out;
 832		}
 833	}
 834
 835	llcp_sock = NULL;
 836
 837out:
 838	read_unlock(&local->connecting_sockets.lock);
 839
 840	return llcp_sock;
 841}
 842
 843static struct nfc_llcp_sock *nfc_llcp_sock_get_sn(struct nfc_llcp_local *local,
 844						  const u8 *sn, size_t sn_len)
 845{
 846	return nfc_llcp_sock_from_sn(local, sn, sn_len, true);
 847}
 848
 849static const u8 *nfc_llcp_connect_sn(const struct sk_buff *skb, size_t *sn_len)
 850{
 851	u8 type, length;
 852	const u8 *tlv = &skb->data[2];
 853	size_t tlv_array_len = skb->len - LLCP_HEADER_SIZE, offset = 0;
 854
 855	while (offset < tlv_array_len) {
 856		type = tlv[0];
 857		length = tlv[1];
 858
 859		pr_debug("type 0x%x length %d\n", type, length);
 860
 861		if (type == LLCP_TLV_SN) {
 862			*sn_len = length;
 863			return &tlv[2];
 864		}
 865
 866		offset += length + 2;
 867		tlv += length + 2;
 868	}
 869
 870	return NULL;
 871}
 872
 873static void nfc_llcp_recv_ui(struct nfc_llcp_local *local,
 874			     struct sk_buff *skb)
 875{
 876	struct nfc_llcp_sock *llcp_sock;
 877	struct nfc_llcp_ui_cb *ui_cb;
 878	u8 dsap, ssap;
 879
 880	dsap = nfc_llcp_dsap(skb);
 881	ssap = nfc_llcp_ssap(skb);
 882
 883	ui_cb = nfc_llcp_ui_skb_cb(skb);
 884	ui_cb->dsap = dsap;
 885	ui_cb->ssap = ssap;
 886
 887	pr_debug("%d %d\n", dsap, ssap);
 888
 889	/* We're looking for a bound socket, not a client one */
 890	llcp_sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
 891	if (llcp_sock == NULL || llcp_sock->sk.sk_type != SOCK_DGRAM)
 892		return;
 893
 894	/* There is no sequence with UI frames */
 895	skb_pull(skb, LLCP_HEADER_SIZE);
 896	if (!sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
 897		/*
 898		 * UI frames will be freed from the socket layer, so we
 899		 * need to keep them alive until someone receives them.
 900		 */
 901		skb_get(skb);
 902	} else {
 903		pr_err("Receive queue is full\n");
 904	}
 905
 906	nfc_llcp_sock_put(llcp_sock);
 907}
 908
 909static void nfc_llcp_recv_connect(struct nfc_llcp_local *local,
 910				  const struct sk_buff *skb)
 911{
 912	struct sock *new_sk, *parent;
 913	struct nfc_llcp_sock *sock, *new_sock;
 914	u8 dsap, ssap, reason;
 915
 916	dsap = nfc_llcp_dsap(skb);
 917	ssap = nfc_llcp_ssap(skb);
 918
 919	pr_debug("%d %d\n", dsap, ssap);
 920
 921	if (dsap != LLCP_SAP_SDP) {
 922		sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
 923		if (sock == NULL || sock->sk.sk_state != LLCP_LISTEN) {
 924			reason = LLCP_DM_NOBOUND;
 925			goto fail;
 926		}
 927	} else {
 928		const u8 *sn;
 929		size_t sn_len;
 930
 931		sn = nfc_llcp_connect_sn(skb, &sn_len);
 932		if (sn == NULL) {
 933			reason = LLCP_DM_NOBOUND;
 934			goto fail;
 935		}
 936
 937		pr_debug("Service name length %zu\n", sn_len);
 938
 939		sock = nfc_llcp_sock_get_sn(local, sn, sn_len);
 940		if (sock == NULL) {
 941			reason = LLCP_DM_NOBOUND;
 942			goto fail;
 943		}
 944	}
 945
 946	lock_sock(&sock->sk);
 947
 948	parent = &sock->sk;
 949
 950	if (sk_acceptq_is_full(parent)) {
 951		reason = LLCP_DM_REJ;
 952		release_sock(&sock->sk);
 953		sock_put(&sock->sk);
 954		goto fail;
 955	}
 956
 957	if (sock->ssap == LLCP_SDP_UNBOUND) {
 958		u8 ssap = nfc_llcp_reserve_sdp_ssap(local);
 959
 960		pr_debug("First client, reserving %d\n", ssap);
 961
 962		if (ssap == LLCP_SAP_MAX) {
 963			reason = LLCP_DM_REJ;
 964			release_sock(&sock->sk);
 965			sock_put(&sock->sk);
 966			goto fail;
 967		}
 968
 969		sock->ssap = ssap;
 970	}
 971
 972	new_sk = nfc_llcp_sock_alloc(NULL, parent->sk_type, GFP_ATOMIC, 0);
 973	if (new_sk == NULL) {
 974		reason = LLCP_DM_REJ;
 975		release_sock(&sock->sk);
 976		sock_put(&sock->sk);
 977		goto fail;
 978	}
 979
 980	new_sock = nfc_llcp_sock(new_sk);
 981
 982	new_sock->local = nfc_llcp_local_get(local);
 983	if (!new_sock->local) {
 984		reason = LLCP_DM_REJ;
 985		sock_put(&new_sock->sk);
 986		release_sock(&sock->sk);
 987		sock_put(&sock->sk);
 988		goto fail;
 989	}
 990
 991	new_sock->dev = local->dev;
 992	new_sock->rw = sock->rw;
 993	new_sock->miux = sock->miux;
 994	new_sock->nfc_protocol = sock->nfc_protocol;
 995	new_sock->dsap = ssap;
 996	new_sock->target_idx = local->target_idx;
 997	new_sock->parent = parent;
 998	new_sock->ssap = sock->ssap;
 999	if (sock->ssap < LLCP_LOCAL_NUM_SAP && sock->ssap >= LLCP_WKS_NUM_SAP) {
1000		atomic_t *client_count;
1001
1002		pr_debug("reserved_ssap %d for %p\n", sock->ssap, new_sock);
1003
1004		client_count =
1005			&local->local_sdp_cnt[sock->ssap - LLCP_WKS_NUM_SAP];
1006
1007		atomic_inc(client_count);
1008		new_sock->reserved_ssap = sock->ssap;
1009	}
1010
1011	nfc_llcp_parse_connection_tlv(new_sock, &skb->data[LLCP_HEADER_SIZE],
1012				      skb->len - LLCP_HEADER_SIZE);
1013
1014	pr_debug("new sock %p sk %p\n", new_sock, &new_sock->sk);
1015
1016	nfc_llcp_sock_link(&local->sockets, new_sk);
1017
1018	nfc_llcp_accept_enqueue(&sock->sk, new_sk);
1019
1020	nfc_get_device(local->dev->idx);
1021
1022	new_sk->sk_state = LLCP_CONNECTED;
1023
1024	/* Wake the listening processes */
1025	parent->sk_data_ready(parent);
1026
1027	/* Send CC */
1028	nfc_llcp_send_cc(new_sock);
1029
1030	release_sock(&sock->sk);
1031	sock_put(&sock->sk);
1032
1033	return;
1034
1035fail:
1036	/* Send DM */
1037	nfc_llcp_send_dm(local, dsap, ssap, reason);
1038}
1039
1040int nfc_llcp_queue_i_frames(struct nfc_llcp_sock *sock)
1041{
1042	int nr_frames = 0;
1043	struct nfc_llcp_local *local = sock->local;
1044
1045	pr_debug("Remote ready %d tx queue len %d remote rw %d",
1046		 sock->remote_ready, skb_queue_len(&sock->tx_pending_queue),
1047		 sock->remote_rw);
1048
1049	/* Try to queue some I frames for transmission */
1050	while (sock->remote_ready &&
1051	       skb_queue_len(&sock->tx_pending_queue) < sock->remote_rw) {
1052		struct sk_buff *pdu;
1053
1054		pdu = skb_dequeue(&sock->tx_queue);
1055		if (pdu == NULL)
1056			break;
1057
1058		/* Update N(S)/N(R) */
1059		nfc_llcp_set_nrns(sock, pdu);
1060
1061		skb_queue_tail(&local->tx_queue, pdu);
1062		nr_frames++;
1063	}
1064
1065	return nr_frames;
1066}
1067
1068static void nfc_llcp_recv_hdlc(struct nfc_llcp_local *local,
1069			       struct sk_buff *skb)
1070{
1071	struct nfc_llcp_sock *llcp_sock;
1072	struct sock *sk;
1073	u8 dsap, ssap, ptype, ns, nr;
1074
1075	ptype = nfc_llcp_ptype(skb);
1076	dsap = nfc_llcp_dsap(skb);
1077	ssap = nfc_llcp_ssap(skb);
1078	ns = nfc_llcp_ns(skb);
1079	nr = nfc_llcp_nr(skb);
1080
1081	pr_debug("%d %d R %d S %d\n", dsap, ssap, nr, ns);
1082
1083	llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1084	if (llcp_sock == NULL) {
1085		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1086		return;
1087	}
1088
1089	sk = &llcp_sock->sk;
1090	lock_sock(sk);
1091	if (sk->sk_state == LLCP_CLOSED) {
1092		release_sock(sk);
1093		nfc_llcp_sock_put(llcp_sock);
1094		return;
1095	}
1096
1097	/* Pass the payload upstream */
1098	if (ptype == LLCP_PDU_I) {
1099		pr_debug("I frame, queueing on %p\n", &llcp_sock->sk);
1100
1101		if (ns == llcp_sock->recv_n)
1102			llcp_sock->recv_n = (llcp_sock->recv_n + 1) % 16;
1103		else
1104			pr_err("Received out of sequence I PDU\n");
1105
1106		skb_pull(skb, LLCP_HEADER_SIZE + LLCP_SEQUENCE_SIZE);
1107		if (!sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
1108			/*
1109			 * I frames will be freed from the socket layer, so we
1110			 * need to keep them alive until someone receives them.
1111			 */
1112			skb_get(skb);
1113		} else {
1114			pr_err("Receive queue is full\n");
1115		}
1116	}
1117
1118	/* Remove skbs from the pending queue */
1119	if (llcp_sock->send_ack_n != nr) {
1120		struct sk_buff *s, *tmp;
1121		u8 n;
1122
1123		llcp_sock->send_ack_n = nr;
1124
1125		/* Remove and free all skbs until ns == nr */
1126		skb_queue_walk_safe(&llcp_sock->tx_pending_queue, s, tmp) {
1127			n = nfc_llcp_ns(s);
1128
1129			skb_unlink(s, &llcp_sock->tx_pending_queue);
1130			kfree_skb(s);
1131
1132			if (n == nr)
1133				break;
1134		}
1135
1136		/* Re-queue the remaining skbs for transmission */
1137		skb_queue_reverse_walk_safe(&llcp_sock->tx_pending_queue,
1138					    s, tmp) {
1139			skb_unlink(s, &llcp_sock->tx_pending_queue);
1140			skb_queue_head(&local->tx_queue, s);
1141		}
1142	}
1143
1144	if (ptype == LLCP_PDU_RR)
1145		llcp_sock->remote_ready = true;
1146	else if (ptype == LLCP_PDU_RNR)
1147		llcp_sock->remote_ready = false;
1148
1149	if (nfc_llcp_queue_i_frames(llcp_sock) == 0 && ptype == LLCP_PDU_I)
1150		nfc_llcp_send_rr(llcp_sock);
1151
1152	release_sock(sk);
1153	nfc_llcp_sock_put(llcp_sock);
1154}
1155
1156static void nfc_llcp_recv_disc(struct nfc_llcp_local *local,
1157			       const struct sk_buff *skb)
1158{
1159	struct nfc_llcp_sock *llcp_sock;
1160	struct sock *sk;
1161	u8 dsap, ssap;
1162
1163	dsap = nfc_llcp_dsap(skb);
1164	ssap = nfc_llcp_ssap(skb);
1165
1166	if ((dsap == 0) && (ssap == 0)) {
1167		pr_debug("Connection termination");
1168		nfc_dep_link_down(local->dev);
1169		return;
1170	}
1171
1172	llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1173	if (llcp_sock == NULL) {
1174		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1175		return;
1176	}
1177
1178	sk = &llcp_sock->sk;
1179	lock_sock(sk);
1180
1181	nfc_llcp_socket_purge(llcp_sock);
1182
1183	if (sk->sk_state == LLCP_CLOSED) {
1184		release_sock(sk);
1185		nfc_llcp_sock_put(llcp_sock);
1186		return;
1187	}
1188
1189	if (sk->sk_state == LLCP_CONNECTED) {
1190		nfc_put_device(local->dev);
1191		sk->sk_state = LLCP_CLOSED;
1192		sk->sk_state_change(sk);
1193	}
1194
1195	nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_DISC);
1196
1197	release_sock(sk);
1198	nfc_llcp_sock_put(llcp_sock);
1199}
1200
1201static void nfc_llcp_recv_cc(struct nfc_llcp_local *local,
1202			     const struct sk_buff *skb)
1203{
1204	struct nfc_llcp_sock *llcp_sock;
1205	struct sock *sk;
1206	u8 dsap, ssap;
1207
1208	dsap = nfc_llcp_dsap(skb);
1209	ssap = nfc_llcp_ssap(skb);
1210
1211	llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
1212	if (llcp_sock == NULL) {
1213		pr_err("Invalid CC\n");
1214		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1215
1216		return;
1217	}
1218
1219	sk = &llcp_sock->sk;
1220
1221	/* Unlink from connecting and link to the client array */
1222	nfc_llcp_sock_unlink(&local->connecting_sockets, sk);
1223	nfc_llcp_sock_link(&local->sockets, sk);
1224	llcp_sock->dsap = ssap;
1225
1226	nfc_llcp_parse_connection_tlv(llcp_sock, &skb->data[LLCP_HEADER_SIZE],
1227				      skb->len - LLCP_HEADER_SIZE);
1228
1229	sk->sk_state = LLCP_CONNECTED;
1230	sk->sk_state_change(sk);
1231
1232	nfc_llcp_sock_put(llcp_sock);
1233}
1234
1235static void nfc_llcp_recv_dm(struct nfc_llcp_local *local,
1236			     const struct sk_buff *skb)
1237{
1238	struct nfc_llcp_sock *llcp_sock;
1239	struct sock *sk;
1240	u8 dsap, ssap, reason;
1241
1242	dsap = nfc_llcp_dsap(skb);
1243	ssap = nfc_llcp_ssap(skb);
1244	reason = skb->data[2];
1245
1246	pr_debug("%d %d reason %d\n", ssap, dsap, reason);
1247
1248	switch (reason) {
1249	case LLCP_DM_NOBOUND:
1250	case LLCP_DM_REJ:
1251		llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
1252		break;
1253
1254	default:
1255		llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1256		break;
1257	}
1258
1259	if (llcp_sock == NULL) {
1260		pr_debug("Already closed\n");
1261		return;
1262	}
1263
1264	sk = &llcp_sock->sk;
1265
1266	sk->sk_err = ENXIO;
1267	sk->sk_state = LLCP_CLOSED;
1268	sk->sk_state_change(sk);
1269
1270	nfc_llcp_sock_put(llcp_sock);
1271}
1272
1273static void nfc_llcp_recv_snl(struct nfc_llcp_local *local,
1274			      const struct sk_buff *skb)
1275{
1276	struct nfc_llcp_sock *llcp_sock;
1277	u8 dsap, ssap, type, length, tid, sap;
1278	const u8 *tlv;
1279	u16 tlv_len, offset;
1280	const char *service_name;
1281	size_t service_name_len;
1282	struct nfc_llcp_sdp_tlv *sdp;
1283	HLIST_HEAD(llc_sdres_list);
1284	size_t sdres_tlvs_len;
1285	HLIST_HEAD(nl_sdres_list);
1286
1287	dsap = nfc_llcp_dsap(skb);
1288	ssap = nfc_llcp_ssap(skb);
1289
1290	pr_debug("%d %d\n", dsap, ssap);
1291
1292	if (dsap != LLCP_SAP_SDP || ssap != LLCP_SAP_SDP) {
1293		pr_err("Wrong SNL SAP\n");
1294		return;
1295	}
1296
1297	tlv = &skb->data[LLCP_HEADER_SIZE];
1298	tlv_len = skb->len - LLCP_HEADER_SIZE;
1299	offset = 0;
1300	sdres_tlvs_len = 0;
1301
1302	while (offset < tlv_len) {
1303		type = tlv[0];
1304		length = tlv[1];
1305
1306		switch (type) {
1307		case LLCP_TLV_SDREQ:
1308			tid = tlv[2];
1309			service_name = (char *) &tlv[3];
1310			service_name_len = length - 1;
1311
1312			pr_debug("Looking for %.16s\n", service_name);
1313
1314			if (service_name_len == strlen("urn:nfc:sn:sdp") &&
1315			    !strncmp(service_name, "urn:nfc:sn:sdp",
1316				     service_name_len)) {
1317				sap = 1;
1318				goto add_snl;
1319			}
1320
1321			llcp_sock = nfc_llcp_sock_from_sn(local, service_name,
1322							  service_name_len,
1323							  true);
1324			if (!llcp_sock) {
1325				sap = 0;
1326				goto add_snl;
1327			}
1328
1329			/*
1330			 * We found a socket but its ssap has not been reserved
1331			 * yet. We need to assign it for good and send a reply.
1332			 * The ssap will be freed when the socket is closed.
1333			 */
1334			if (llcp_sock->ssap == LLCP_SDP_UNBOUND) {
1335				atomic_t *client_count;
1336
1337				sap = nfc_llcp_reserve_sdp_ssap(local);
1338
1339				pr_debug("Reserving %d\n", sap);
1340
1341				if (sap == LLCP_SAP_MAX) {
1342					sap = 0;
1343					nfc_llcp_sock_put(llcp_sock);
1344					goto add_snl;
1345				}
1346
1347				client_count =
1348					&local->local_sdp_cnt[sap -
1349							      LLCP_WKS_NUM_SAP];
1350
1351				atomic_inc(client_count);
1352
1353				llcp_sock->ssap = sap;
1354				llcp_sock->reserved_ssap = sap;
1355			} else {
1356				sap = llcp_sock->ssap;
1357			}
1358
1359			pr_debug("%p %d\n", llcp_sock, sap);
1360
1361			nfc_llcp_sock_put(llcp_sock);
1362add_snl:
1363			sdp = nfc_llcp_build_sdres_tlv(tid, sap);
1364			if (sdp == NULL)
1365				goto exit;
1366
1367			sdres_tlvs_len += sdp->tlv_len;
1368			hlist_add_head(&sdp->node, &llc_sdres_list);
1369			break;
1370
1371		case LLCP_TLV_SDRES:
1372			mutex_lock(&local->sdreq_lock);
1373
1374			pr_debug("LLCP_TLV_SDRES: searching tid %d\n", tlv[2]);
1375
1376			hlist_for_each_entry(sdp, &local->pending_sdreqs, node) {
1377				if (sdp->tid != tlv[2])
1378					continue;
1379
1380				sdp->sap = tlv[3];
1381
1382				pr_debug("Found: uri=%s, sap=%d\n",
1383					 sdp->uri, sdp->sap);
1384
1385				hlist_del(&sdp->node);
1386
1387				hlist_add_head(&sdp->node, &nl_sdres_list);
1388
1389				break;
1390			}
1391
1392			mutex_unlock(&local->sdreq_lock);
1393			break;
1394
1395		default:
1396			pr_err("Invalid SNL tlv value 0x%x\n", type);
1397			break;
1398		}
1399
1400		offset += length + 2;
1401		tlv += length + 2;
1402	}
1403
1404exit:
1405	if (!hlist_empty(&nl_sdres_list))
1406		nfc_genl_llc_send_sdres(local->dev, &nl_sdres_list);
1407
1408	if (!hlist_empty(&llc_sdres_list))
1409		nfc_llcp_send_snl_sdres(local, &llc_sdres_list, sdres_tlvs_len);
1410}
1411
1412static void nfc_llcp_recv_agf(struct nfc_llcp_local *local, struct sk_buff *skb)
1413{
1414	u8 ptype;
1415	u16 pdu_len;
1416	struct sk_buff *new_skb;
1417
1418	if (skb->len <= LLCP_HEADER_SIZE) {
1419		pr_err("Malformed AGF PDU\n");
1420		return;
1421	}
1422
1423	skb_pull(skb, LLCP_HEADER_SIZE);
1424
1425	while (skb->len > LLCP_AGF_PDU_HEADER_SIZE) {
1426		pdu_len = skb->data[0] << 8 | skb->data[1];
1427
1428		skb_pull(skb, LLCP_AGF_PDU_HEADER_SIZE);
1429
1430		if (pdu_len < LLCP_HEADER_SIZE || pdu_len > skb->len) {
1431			pr_err("Malformed AGF PDU\n");
1432			return;
1433		}
1434
1435		ptype = nfc_llcp_ptype(skb);
1436
1437		if (ptype == LLCP_PDU_SYMM || ptype == LLCP_PDU_AGF)
1438			goto next;
1439
1440		new_skb = nfc_alloc_recv_skb(pdu_len, GFP_KERNEL);
1441		if (new_skb == NULL) {
1442			pr_err("Could not allocate PDU\n");
1443			return;
1444		}
1445
1446		skb_put_data(new_skb, skb->data, pdu_len);
1447
1448		nfc_llcp_rx_skb(local, new_skb);
1449
1450		kfree_skb(new_skb);
1451next:
1452		skb_pull(skb, pdu_len);
1453	}
1454}
1455
1456static void nfc_llcp_rx_skb(struct nfc_llcp_local *local, struct sk_buff *skb)
1457{
1458	u8 dsap, ssap, ptype;
1459
1460	ptype = nfc_llcp_ptype(skb);
1461	dsap = nfc_llcp_dsap(skb);
1462	ssap = nfc_llcp_ssap(skb);
1463
1464	pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap);
1465
1466	if (ptype != LLCP_PDU_SYMM)
1467		print_hex_dump_debug("LLCP Rx: ", DUMP_PREFIX_OFFSET, 16, 1,
1468				     skb->data, skb->len, true);
1469
1470	switch (ptype) {
1471	case LLCP_PDU_SYMM:
1472		pr_debug("SYMM\n");
1473		break;
1474
1475	case LLCP_PDU_UI:
1476		pr_debug("UI\n");
1477		nfc_llcp_recv_ui(local, skb);
1478		break;
1479
1480	case LLCP_PDU_CONNECT:
1481		pr_debug("CONNECT\n");
1482		nfc_llcp_recv_connect(local, skb);
1483		break;
1484
1485	case LLCP_PDU_DISC:
1486		pr_debug("DISC\n");
1487		nfc_llcp_recv_disc(local, skb);
1488		break;
1489
1490	case LLCP_PDU_CC:
1491		pr_debug("CC\n");
1492		nfc_llcp_recv_cc(local, skb);
1493		break;
1494
1495	case LLCP_PDU_DM:
1496		pr_debug("DM\n");
1497		nfc_llcp_recv_dm(local, skb);
1498		break;
1499
1500	case LLCP_PDU_SNL:
1501		pr_debug("SNL\n");
1502		nfc_llcp_recv_snl(local, skb);
1503		break;
1504
1505	case LLCP_PDU_I:
1506	case LLCP_PDU_RR:
1507	case LLCP_PDU_RNR:
1508		pr_debug("I frame\n");
1509		nfc_llcp_recv_hdlc(local, skb);
1510		break;
1511
1512	case LLCP_PDU_AGF:
1513		pr_debug("AGF frame\n");
1514		nfc_llcp_recv_agf(local, skb);
1515		break;
1516	}
1517}
1518
1519static void nfc_llcp_rx_work(struct work_struct *work)
1520{
1521	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
1522						    rx_work);
1523	struct sk_buff *skb;
1524
1525	skb = local->rx_pending;
1526	if (skb == NULL) {
1527		pr_debug("No pending SKB\n");
1528		return;
1529	}
1530
1531	__net_timestamp(skb);
1532
1533	nfc_llcp_send_to_raw_sock(local, skb, NFC_DIRECTION_RX);
1534
1535	nfc_llcp_rx_skb(local, skb);
1536
1537	schedule_work(&local->tx_work);
1538	kfree_skb(local->rx_pending);
1539	local->rx_pending = NULL;
1540}
1541
1542static void __nfc_llcp_recv(struct nfc_llcp_local *local, struct sk_buff *skb)
1543{
1544	local->rx_pending = skb;
1545	timer_delete(&local->link_timer);
1546	schedule_work(&local->rx_work);
1547}
1548
1549void nfc_llcp_recv(void *data, struct sk_buff *skb, int err)
1550{
1551	struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
1552
1553	if (err < 0) {
1554		pr_err("LLCP PDU receive err %d\n", err);
1555		return;
1556	}
1557
1558	__nfc_llcp_recv(local, skb);
1559}
1560
1561int nfc_llcp_data_received(struct nfc_dev *dev, struct sk_buff *skb)
1562{
1563	struct nfc_llcp_local *local;
1564
1565	local = nfc_llcp_find_local(dev);
1566	if (local == NULL) {
1567		kfree_skb(skb);
1568		return -ENODEV;
1569	}
1570
1571	__nfc_llcp_recv(local, skb);
1572
1573	nfc_llcp_local_put(local);
1574
1575	return 0;
1576}
1577
1578void nfc_llcp_mac_is_down(struct nfc_dev *dev)
1579{
1580	struct nfc_llcp_local *local;
1581
1582	local = nfc_llcp_find_local(dev);
1583	if (local == NULL)
1584		return;
1585
1586	local->remote_miu = LLCP_DEFAULT_MIU;
1587	local->remote_lto = LLCP_DEFAULT_LTO;
1588
1589	/* Close and purge all existing sockets */
1590	nfc_llcp_socket_release(local, true, 0);
1591
1592	nfc_llcp_local_put(local);
1593}
1594
1595void nfc_llcp_mac_is_up(struct nfc_dev *dev, u32 target_idx,
1596			u8 comm_mode, u8 rf_mode)
1597{
1598	struct nfc_llcp_local *local;
1599
1600	pr_debug("rf mode %d\n", rf_mode);
1601
1602	local = nfc_llcp_find_local(dev);
1603	if (local == NULL)
1604		return;
1605
1606	local->target_idx = target_idx;
1607	local->comm_mode = comm_mode;
1608	local->rf_mode = rf_mode;
1609
1610	if (rf_mode == NFC_RF_INITIATOR) {
1611		pr_debug("Queueing Tx work\n");
1612
1613		schedule_work(&local->tx_work);
1614	} else {
1615		mod_timer(&local->link_timer,
1616			  jiffies + msecs_to_jiffies(local->remote_lto));
1617	}
1618
1619	nfc_llcp_local_put(local);
1620}
1621
1622int nfc_llcp_register_device(struct nfc_dev *ndev)
1623{
1624	struct nfc_llcp_local *local;
1625
1626	local = kzalloc(sizeof(struct nfc_llcp_local), GFP_KERNEL);
1627	if (local == NULL)
1628		return -ENOMEM;
1629
1630	/* As we are going to initialize local's refcount, we need to get the
1631	 * nfc_dev to avoid UAF, otherwise there is no point in continuing.
1632	 * See nfc_llcp_local_get().
1633	 */
1634	local->dev = nfc_get_device(ndev->idx);
1635	if (!local->dev) {
1636		kfree(local);
1637		return -ENODEV;
1638	}
1639
1640	INIT_LIST_HEAD(&local->list);
1641	kref_init(&local->ref);
1642	mutex_init(&local->sdp_lock);
1643	timer_setup(&local->link_timer, nfc_llcp_symm_timer, 0);
1644
1645	skb_queue_head_init(&local->tx_queue);
1646	INIT_WORK(&local->tx_work, nfc_llcp_tx_work);
1647
1648	local->rx_pending = NULL;
1649	INIT_WORK(&local->rx_work, nfc_llcp_rx_work);
1650
1651	INIT_WORK(&local->timeout_work, nfc_llcp_timeout_work);
1652
1653	rwlock_init(&local->sockets.lock);
1654	rwlock_init(&local->connecting_sockets.lock);
1655	rwlock_init(&local->raw_sockets.lock);
1656
1657	local->lto = 150; /* 1500 ms */
1658	local->rw = LLCP_MAX_RW;
1659	local->miux = cpu_to_be16(LLCP_MAX_MIUX);
1660	local->local_wks = 0x1; /* LLC Link Management */
1661
1662	nfc_llcp_build_gb(local);
1663
1664	local->remote_miu = LLCP_DEFAULT_MIU;
1665	local->remote_lto = LLCP_DEFAULT_LTO;
1666
1667	mutex_init(&local->sdreq_lock);
1668	INIT_HLIST_HEAD(&local->pending_sdreqs);
1669	timer_setup(&local->sdreq_timer, nfc_llcp_sdreq_timer, 0);
1670	INIT_WORK(&local->sdreq_timeout_work, nfc_llcp_sdreq_timeout_work);
1671
1672	spin_lock(&llcp_devices_lock);
1673	list_add(&local->list, &llcp_devices);
1674	spin_unlock(&llcp_devices_lock);
1675
1676	return 0;
1677}
1678
1679void nfc_llcp_unregister_device(struct nfc_dev *dev)
1680{
1681	struct nfc_llcp_local *local = nfc_llcp_remove_local(dev);
1682
1683	if (local == NULL) {
1684		pr_debug("No such device\n");
1685		return;
1686	}
1687
1688	local_cleanup(local);
1689
1690	nfc_llcp_local_put(local);
1691}
1692
1693int __init nfc_llcp_init(void)
1694{
1695	return nfc_llcp_sock_init();
1696}
1697
1698void nfc_llcp_exit(void)
1699{
1700	nfc_llcp_sock_exit();
1701}