/*
   * Copyright (C) 2011  Intel Corporation. All rights reserved.

   * Copyright (C) 2014 Marvell International Ltd.

   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License

   * along with this program; if not, see <http://www.gnu.org/licenses/>.

   */
  
  #define pr_fmt(fmt) "llcp: %s: " fmt, __func__
  
  #include <linux/init.h>
  #include <linux/kernel.h>
  #include <linux/list.h>
  #include <linux/nfc.h>

  #include "nfc.h"

  #include "llcp.h"
  
  static u8 llcp_magic[3] = {0x46, 0x66, 0x6d};

  static LIST_HEAD(llcp_devices);

  static void nfc_llcp_rx_skb(struct nfc_llcp_local *local, struct sk_buff *skb);

  void nfc_llcp_sock_link(struct llcp_sock_list *l, struct sock *sk)

  {

  	write_lock(&l->lock);
  	sk_add_node(sk, &l->head);
  	write_unlock(&l->lock);
  }

  void nfc_llcp_sock_unlink(struct llcp_sock_list *l, struct sock *sk)
  {
  	write_lock(&l->lock);
  	sk_del_node_init(sk);
  	write_unlock(&l->lock);
  }

  void nfc_llcp_socket_remote_param_init(struct nfc_llcp_sock *sock)
  {
  	sock->remote_rw = LLCP_DEFAULT_RW;
  	sock->remote_miu = LLCP_MAX_MIU + 1;
  }

  static void nfc_llcp_socket_purge(struct nfc_llcp_sock *sock)
  {
  	struct nfc_llcp_local *local = sock->local;
  	struct sk_buff *s, *tmp;
  
  	pr_debug("%p
  ", &sock->sk);
  
  	skb_queue_purge(&sock->tx_queue);
  	skb_queue_purge(&sock->tx_pending_queue);

  
  	if (local == NULL)
  		return;
  
  	/* Search for local pending SKBs that are related to this socket */
  	skb_queue_walk_safe(&local->tx_queue, s, tmp) {
  		if (s->sk != &sock->sk)
  			continue;
  
  		skb_unlink(s, &local->tx_queue);
  		kfree_skb(s);
  	}
  }

  static void nfc_llcp_socket_release(struct nfc_llcp_local *local, bool device,

  				    int err)

  {
  	struct sock *sk;

  	struct hlist_node *tmp;

  	struct nfc_llcp_sock *llcp_sock;

  	skb_queue_purge(&local->tx_queue);

  	write_lock(&local->sockets.lock);

  	sk_for_each_safe(sk, tmp, &local->sockets.head) {

  		llcp_sock = nfc_llcp_sock(sk);

  		bh_lock_sock(sk);

  		nfc_llcp_socket_purge(llcp_sock);

  		if (sk->sk_state == LLCP_CONNECTED)
  			nfc_put_device(llcp_sock->dev);

  		if (sk->sk_state == LLCP_LISTEN) {

  			struct nfc_llcp_sock *lsk, *n;
  			struct sock *accept_sk;

  			list_for_each_entry_safe(lsk, n,
  						 &llcp_sock->accept_queue,

  						 accept_queue) {

  				accept_sk = &lsk->sk;

  				bh_lock_sock(accept_sk);

  
  				nfc_llcp_accept_unlink(accept_sk);

  				if (err)
  					accept_sk->sk_err = err;

  				accept_sk->sk_state = LLCP_CLOSED;

  				accept_sk->sk_state_change(sk);

  				bh_unlock_sock(accept_sk);

  			}

  		}

  		if (err)
  			sk->sk_err = err;

  		sk->sk_state = LLCP_CLOSED;

  		sk->sk_state_change(sk);

  		bh_unlock_sock(sk);

  		sk_del_node_init(sk);

  	}

  	write_unlock(&local->sockets.lock);

  	/* If we still have a device, we keep the RAW sockets alive */
  	if (device == true)

  		return;
  
  	write_lock(&local->raw_sockets.lock);
  
  	sk_for_each_safe(sk, tmp, &local->raw_sockets.head) {
  		llcp_sock = nfc_llcp_sock(sk);
  
  		bh_lock_sock(sk);
  
  		nfc_llcp_socket_purge(llcp_sock);

  		if (err)
  			sk->sk_err = err;

  		sk->sk_state = LLCP_CLOSED;

  		sk->sk_state_change(sk);
  
  		bh_unlock_sock(sk);

  		sk_del_node_init(sk);
  	}
  
  	write_unlock(&local->raw_sockets.lock);

  }

  struct nfc_llcp_local *nfc_llcp_local_get(struct nfc_llcp_local *local)
  {
  	kref_get(&local->ref);
  
  	return local;
  }

  static void local_cleanup(struct nfc_llcp_local *local)

  {

  	nfc_llcp_socket_release(local, false, ENXIO);

  	del_timer_sync(&local->link_timer);
  	skb_queue_purge(&local->tx_queue);

  	cancel_work_sync(&local->tx_work);
  	cancel_work_sync(&local->rx_work);
  	cancel_work_sync(&local->timeout_work);

  	kfree_skb(local->rx_pending);

  	del_timer_sync(&local->sdreq_timer);
  	cancel_work_sync(&local->sdreq_timeout_work);

  	nfc_llcp_free_sdp_tlv_list(&local->pending_sdreqs);

  }
  
  static void local_release(struct kref *ref)
  {
  	struct nfc_llcp_local *local;
  
  	local = container_of(ref, struct nfc_llcp_local, ref);
  
  	list_del(&local->list);

  	local_cleanup(local);

  	kfree(local);
  }
  
  int nfc_llcp_local_put(struct nfc_llcp_local *local)
  {

  	if (local == NULL)
  		return 0;

  	return kref_put(&local->ref, local_release);
  }

  static struct nfc_llcp_sock *nfc_llcp_sock_get(struct nfc_llcp_local *local,
  					       u8 ssap, u8 dsap)
  {
  	struct sock *sk;

  	struct nfc_llcp_sock *llcp_sock, *tmp_sock;

  
  	pr_debug("ssap dsap %d %d
  ", ssap, dsap);
  
  	if (ssap == 0 && dsap == 0)
  		return NULL;
  
  	read_lock(&local->sockets.lock);
  
  	llcp_sock = NULL;

  	sk_for_each(sk, &local->sockets.head) {

  		tmp_sock = nfc_llcp_sock(sk);

  		if (tmp_sock->ssap == ssap && tmp_sock->dsap == dsap) {
  			llcp_sock = tmp_sock;

  			break;

  		}

  	}
  
  	read_unlock(&local->sockets.lock);
  
  	if (llcp_sock == NULL)
  		return NULL;
  
  	sock_hold(&llcp_sock->sk);
  
  	return llcp_sock;
  }
  
  static void nfc_llcp_sock_put(struct nfc_llcp_sock *sock)
  {
  	sock_put(&sock->sk);
  }

  static void nfc_llcp_timeout_work(struct work_struct *work)
  {
  	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,

  						    timeout_work);

  
  	nfc_dep_link_down(local->dev);
  }
  
  static void nfc_llcp_symm_timer(unsigned long data)
  {
  	struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
  
  	pr_err("SYMM timeout
  ");

  	schedule_work(&local->timeout_work);

  }

  static void nfc_llcp_sdreq_timeout_work(struct work_struct *work)
  {
  	unsigned long time;
  	HLIST_HEAD(nl_sdres_list);
  	struct hlist_node *n;
  	struct nfc_llcp_sdp_tlv *sdp;
  	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
  						    sdreq_timeout_work);
  
  	mutex_lock(&local->sdreq_lock);
  
  	time = jiffies - msecs_to_jiffies(3 * local->remote_lto);
  
  	hlist_for_each_entry_safe(sdp, n, &local->pending_sdreqs, node) {
  		if (time_after(sdp->time, time))
  			continue;
  
  		sdp->sap = LLCP_SDP_UNBOUND;
  
  		hlist_del(&sdp->node);
  
  		hlist_add_head(&sdp->node, &nl_sdres_list);
  	}
  
  	if (!hlist_empty(&local->pending_sdreqs))
  		mod_timer(&local->sdreq_timer,
  			  jiffies + msecs_to_jiffies(3 * local->remote_lto));
  
  	mutex_unlock(&local->sdreq_lock);
  
  	if (!hlist_empty(&nl_sdres_list))
  		nfc_genl_llc_send_sdres(local->dev, &nl_sdres_list);
  }
  
  static void nfc_llcp_sdreq_timer(unsigned long data)
  {
  	struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
  
  	schedule_work(&local->sdreq_timeout_work);
  }

  struct nfc_llcp_local *nfc_llcp_find_local(struct nfc_dev *dev)
  {

  	struct nfc_llcp_local *local;

  	list_for_each_entry(local, &llcp_devices, list)

  		if (local->dev == dev)
  			return local;
  
  	pr_debug("No device found
  ");
  
  	return NULL;
  }
  
  static char *wks[] = {
  	NULL,
  	NULL, /* SDP */
  	"urn:nfc:sn:ip",
  	"urn:nfc:sn:obex",
  	"urn:nfc:sn:snep",
  };
  
  static int nfc_llcp_wks_sap(char *service_name, size_t service_name_len)
  {
  	int sap, num_wks;
  
  	pr_debug("%s
  ", service_name);
  
  	if (service_name == NULL)
  		return -EINVAL;
  
  	num_wks = ARRAY_SIZE(wks);

  	for (sap = 0; sap < num_wks; sap++) {

  		if (wks[sap] == NULL)
  			continue;
  
  		if (strncmp(wks[sap], service_name, service_name_len) == 0)
  			return sap;
  	}
  
  	return -EINVAL;
  }

  static
  struct nfc_llcp_sock *nfc_llcp_sock_from_sn(struct nfc_llcp_local *local,
  					    u8 *sn, size_t sn_len)
  {
  	struct sock *sk;

  	struct nfc_llcp_sock *llcp_sock, *tmp_sock;
  
  	pr_debug("sn %zd %p
  ", sn_len, sn);
  
  	if (sn == NULL || sn_len == 0)
  		return NULL;
  
  	read_lock(&local->sockets.lock);
  
  	llcp_sock = NULL;

  	sk_for_each(sk, &local->sockets.head) {

  		tmp_sock = nfc_llcp_sock(sk);
  
  		pr_debug("llcp sock %p
  ", tmp_sock);

  		if (tmp_sock->sk.sk_type == SOCK_STREAM &&
  		    tmp_sock->sk.sk_state != LLCP_LISTEN)
  			continue;
  
  		if (tmp_sock->sk.sk_type == SOCK_DGRAM &&
  		    tmp_sock->sk.sk_state != LLCP_BOUND)

  			continue;
  
  		if (tmp_sock->service_name == NULL ||
  		    tmp_sock->service_name_len == 0)
  			continue;
  
  		if (tmp_sock->service_name_len != sn_len)
  			continue;
  
  		if (memcmp(sn, tmp_sock->service_name, sn_len) == 0) {
  			llcp_sock = tmp_sock;
  			break;
  		}
  	}
  
  	read_unlock(&local->sockets.lock);
  
  	pr_debug("Found llcp sock %p
  ", llcp_sock);
  
  	return llcp_sock;
  }

  u8 nfc_llcp_get_sdp_ssap(struct nfc_llcp_local *local,

  			 struct nfc_llcp_sock *sock)

  {
  	mutex_lock(&local->sdp_lock);
  
  	if (sock->service_name != NULL && sock->service_name_len > 0) {
  		int ssap = nfc_llcp_wks_sap(sock->service_name,

  					    sock->service_name_len);

  
  		if (ssap > 0) {
  			pr_debug("WKS %d
  ", ssap);
  
  			/* This is a WKS, let's check if it's free */
  			if (local->local_wks & BIT(ssap)) {
  				mutex_unlock(&local->sdp_lock);
  
  				return LLCP_SAP_MAX;
  			}

  			set_bit(ssap, &local->local_wks);

  			mutex_unlock(&local->sdp_lock);
  
  			return ssap;
  		}
  
  		/*

  		 * Check if there already is a non WKS socket bound
  		 * to this service name.

  		 */

  		if (nfc_llcp_sock_from_sn(local, sock->service_name,
  					  sock->service_name_len) != NULL) {

  			mutex_unlock(&local->sdp_lock);
  
  			return LLCP_SAP_MAX;
  		}

  		mutex_unlock(&local->sdp_lock);

  		return LLCP_SDP_UNBOUND;

  	} else if (sock->ssap != 0 && sock->ssap < LLCP_WKS_NUM_SAP) {
  		if (!test_bit(sock->ssap, &local->local_wks)) {
  			set_bit(sock->ssap, &local->local_wks);
  			mutex_unlock(&local->sdp_lock);

  			return sock->ssap;

  		}
  	}
  
  	mutex_unlock(&local->sdp_lock);
  
  	return LLCP_SAP_MAX;
  }
  
  u8 nfc_llcp_get_local_ssap(struct nfc_llcp_local *local)
  {
  	u8 local_ssap;
  
  	mutex_lock(&local->sdp_lock);
  
  	local_ssap = find_first_zero_bit(&local->local_sap, LLCP_LOCAL_NUM_SAP);
  	if (local_ssap == LLCP_LOCAL_NUM_SAP) {
  		mutex_unlock(&local->sdp_lock);
  		return LLCP_SAP_MAX;
  	}

  	set_bit(local_ssap, &local->local_sap);

  
  	mutex_unlock(&local->sdp_lock);
  
  	return local_ssap + LLCP_LOCAL_SAP_OFFSET;
  }
  
  void nfc_llcp_put_ssap(struct nfc_llcp_local *local, u8 ssap)
  {
  	u8 local_ssap;
  	unsigned long *sdp;
  
  	if (ssap < LLCP_WKS_NUM_SAP) {
  		local_ssap = ssap;
  		sdp = &local->local_wks;
  	} else if (ssap < LLCP_LOCAL_NUM_SAP) {

  		atomic_t *client_cnt;

  		local_ssap = ssap - LLCP_WKS_NUM_SAP;
  		sdp = &local->local_sdp;

  		client_cnt = &local->local_sdp_cnt[local_ssap];
  
  		pr_debug("%d clients
  ", atomic_read(client_cnt));
  
  		mutex_lock(&local->sdp_lock);
  
  		if (atomic_dec_and_test(client_cnt)) {
  			struct nfc_llcp_sock *l_sock;
  
  			pr_debug("No more clients for SAP %d
  ", ssap);
  
  			clear_bit(local_ssap, sdp);
  
  			/* Find the listening sock and set it back to UNBOUND */
  			l_sock = nfc_llcp_sock_get(local, ssap, LLCP_SAP_SDP);
  			if (l_sock) {
  				l_sock->ssap = LLCP_SDP_UNBOUND;
  				nfc_llcp_sock_put(l_sock);
  			}
  		}
  
  		mutex_unlock(&local->sdp_lock);
  
  		return;

  	} else if (ssap < LLCP_MAX_SAP) {
  		local_ssap = ssap - LLCP_LOCAL_NUM_SAP;
  		sdp = &local->local_sap;
  	} else {
  		return;
  	}
  
  	mutex_lock(&local->sdp_lock);

  	clear_bit(local_ssap, sdp);

  
  	mutex_unlock(&local->sdp_lock);
  }

  static u8 nfc_llcp_reserve_sdp_ssap(struct nfc_llcp_local *local)
  {
  	u8 ssap;
  
  	mutex_lock(&local->sdp_lock);
  
  	ssap = find_first_zero_bit(&local->local_sdp, LLCP_SDP_NUM_SAP);
  	if (ssap == LLCP_SDP_NUM_SAP) {
  		mutex_unlock(&local->sdp_lock);
  
  		return LLCP_SAP_MAX;
  	}
  
  	pr_debug("SDP ssap %d
  ", LLCP_WKS_NUM_SAP + ssap);
  
  	set_bit(ssap, &local->local_sdp);
  
  	mutex_unlock(&local->sdp_lock);
  
  	return LLCP_WKS_NUM_SAP + ssap;
  }

  static int nfc_llcp_build_gb(struct nfc_llcp_local *local)
  {
  	u8 *gb_cur, *version_tlv, version, version_length;

  	u8 *lto_tlv, lto_length;

  	u8 *wks_tlv, wks_length;

  	u8 *miux_tlv, miux_length;

  	__be16 wks = cpu_to_be16(local->local_wks);

  	u8 gb_len = 0;

  	int ret = 0;

  
  	version = LLCP_VERSION_11;
  	version_tlv = nfc_llcp_build_tlv(LLCP_TLV_VERSION, &version,

  					 1, &version_length);

  	gb_len += version_length;

  	lto_tlv = nfc_llcp_build_tlv(LLCP_TLV_LTO, &local->lto, 1, &lto_length);

  	gb_len += lto_length;
  
  	pr_debug("Local wks 0x%lx
  ", local->local_wks);

  	wks_tlv = nfc_llcp_build_tlv(LLCP_TLV_WKS, (u8 *)&wks, 2, &wks_length);

  	gb_len += wks_length;

  	miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&local->miux, 0,

  				      &miux_length);
  	gb_len += miux_length;

  	gb_len += ARRAY_SIZE(llcp_magic);
  
  	if (gb_len > NFC_MAX_GT_LEN) {

  		ret = -EINVAL;
  		goto out;

  	}
  
  	gb_cur = local->gb;
  
  	memcpy(gb_cur, llcp_magic, ARRAY_SIZE(llcp_magic));
  	gb_cur += ARRAY_SIZE(llcp_magic);
  
  	memcpy(gb_cur, version_tlv, version_length);
  	gb_cur += version_length;
  
  	memcpy(gb_cur, lto_tlv, lto_length);
  	gb_cur += lto_length;
  
  	memcpy(gb_cur, wks_tlv, wks_length);
  	gb_cur += wks_length;

  	memcpy(gb_cur, miux_tlv, miux_length);
  	gb_cur += miux_length;

  	local->gb_len = gb_len;
  
  out:

  	kfree(version_tlv);
  	kfree(lto_tlv);

  	kfree(wks_tlv);
  	kfree(miux_tlv);

  	return ret;

  }

  u8 *nfc_llcp_general_bytes(struct nfc_dev *dev, size_t *general_bytes_len)
  {
  	struct nfc_llcp_local *local;
  
  	local = nfc_llcp_find_local(dev);
  	if (local == NULL) {
  		*general_bytes_len = 0;
  		return NULL;
  	}
  
  	nfc_llcp_build_gb(local);
  
  	*general_bytes_len = local->gb_len;
  
  	return local->gb;
  }

  int nfc_llcp_set_remote_gb(struct nfc_dev *dev, u8 *gb, u8 gb_len)
  {

  	struct nfc_llcp_local *local;
  
  	if (gb_len < 3 || gb_len > NFC_MAX_GT_LEN)
  		return -EINVAL;

  	local = nfc_llcp_find_local(dev);

  	if (local == NULL) {
  		pr_err("No LLCP device
  ");
  		return -ENODEV;
  	}
  
  	memset(local->remote_gb, 0, NFC_MAX_GT_LEN);
  	memcpy(local->remote_gb, gb, gb_len);
  	local->remote_gb_len = gb_len;

  	if (memcmp(local->remote_gb, llcp_magic, 3)) {
  		pr_err("MAC does not support LLCP
  ");
  		return -EINVAL;
  	}

  	return nfc_llcp_parse_gb_tlv(local,
  				     &local->remote_gb[3],
  				     local->remote_gb_len - 3);

  }

  static u8 nfc_llcp_dsap(struct sk_buff *pdu)
  {
  	return (pdu->data[0] & 0xfc) >> 2;
  }
  
  static u8 nfc_llcp_ptype(struct sk_buff *pdu)
  {
  	return ((pdu->data[0] & 0x03) << 2) | ((pdu->data[1] & 0xc0) >> 6);
  }
  
  static u8 nfc_llcp_ssap(struct sk_buff *pdu)
  {
  	return pdu->data[1] & 0x3f;
  }
  
  static u8 nfc_llcp_ns(struct sk_buff *pdu)
  {
  	return pdu->data[2] >> 4;
  }
  
  static u8 nfc_llcp_nr(struct sk_buff *pdu)
  {
  	return pdu->data[2] & 0xf;
  }
  
  static void nfc_llcp_set_nrns(struct nfc_llcp_sock *sock, struct sk_buff *pdu)
  {

  	pdu->data[2] = (sock->send_n << 4) | (sock->recv_n);

  	sock->send_n = (sock->send_n + 1) % 16;
  	sock->recv_ack_n = (sock->recv_n - 1) % 16;
  }

  void nfc_llcp_send_to_raw_sock(struct nfc_llcp_local *local,
  			       struct sk_buff *skb, u8 direction)
  {

  	struct sk_buff *skb_copy = NULL, *nskb;
  	struct sock *sk;
  	u8 *data;
  
  	read_lock(&local->raw_sockets.lock);

  	sk_for_each(sk, &local->raw_sockets.head) {

  		if (sk->sk_state != LLCP_BOUND)
  			continue;
  
  		if (skb_copy == NULL) {

  			skb_copy = __pskb_copy_fclone(skb, NFC_RAW_HEADER_SIZE,
  						      GFP_ATOMIC, true);

  
  			if (skb_copy == NULL)
  				continue;

  			data = skb_push(skb_copy, NFC_RAW_HEADER_SIZE);

  
  			data[0] = local->dev ? local->dev->idx : 0xFF;

  			data[1] = direction & 0x01;
  			data[1] |= (RAW_PAYLOAD_LLCP << 1);

  		}
  
  		nskb = skb_clone(skb_copy, GFP_ATOMIC);
  		if (!nskb)
  			continue;
  
  		if (sock_queue_rcv_skb(sk, nskb))
  			kfree_skb(nskb);
  	}
  
  	read_unlock(&local->raw_sockets.lock);
  
  	kfree_skb(skb_copy);
  }

  static void nfc_llcp_tx_work(struct work_struct *work)
  {
  	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
  						    tx_work);
  	struct sk_buff *skb;
  	struct sock *sk;
  	struct nfc_llcp_sock *llcp_sock;
  
  	skb = skb_dequeue(&local->tx_queue);
  	if (skb != NULL) {
  		sk = skb->sk;
  		llcp_sock = nfc_llcp_sock(sk);

  
  		if (llcp_sock == NULL && nfc_llcp_ptype(skb) == LLCP_PDU_I) {

  			kfree_skb(skb);

  			nfc_llcp_send_symm(local->dev);

  		} else if (llcp_sock && !llcp_sock->remote_ready) {
  			skb_queue_head(&local->tx_queue, skb);
  			nfc_llcp_send_symm(local->dev);

  		} else {

  			struct sk_buff *copy_skb = NULL;
  			u8 ptype = nfc_llcp_ptype(skb);

  			int ret;
  
  			pr_debug("Sending pending skb
  ");

  			print_hex_dump_debug("LLCP Tx: ", DUMP_PREFIX_OFFSET,
  					     16, 1, skb->data, skb->len, true);

  			if (ptype == LLCP_PDU_DISC && sk != NULL &&
  			    sk->sk_state == LLCP_DISCONNECTING) {
  				nfc_llcp_sock_unlink(&local->sockets, sk);
  				sock_orphan(sk);
  				sock_put(sk);
  			}

  			if (ptype == LLCP_PDU_I)
  				copy_skb = skb_copy(skb, GFP_ATOMIC);

  			__net_timestamp(skb);

  			nfc_llcp_send_to_raw_sock(local, skb,

  						  NFC_DIRECTION_TX);

  			ret = nfc_data_exchange(local->dev, local->target_idx,
  						skb, nfc_llcp_recv, local);

  			if (ret) {
  				kfree_skb(copy_skb);
  				goto out;

  			}

  
  			if (ptype == LLCP_PDU_I && copy_skb)
  				skb_queue_tail(&llcp_sock->tx_pending_queue,
  					       copy_skb);

  		}
  	} else {
  		nfc_llcp_send_symm(local->dev);
  	}

  out:

  	mod_timer(&local->link_timer,
  		  jiffies + msecs_to_jiffies(2 * local->remote_lto));
  }

  static struct nfc_llcp_sock *nfc_llcp_connecting_sock_get(struct nfc_llcp_local *local,
  							  u8 ssap)
  {
  	struct sock *sk;
  	struct nfc_llcp_sock *llcp_sock;

  
  	read_lock(&local->connecting_sockets.lock);

  	sk_for_each(sk, &local->connecting_sockets.head) {

  		llcp_sock = nfc_llcp_sock(sk);

  		if (llcp_sock->ssap == ssap) {
  			sock_hold(&llcp_sock->sk);

  			goto out;

  		}

  	}
  
  	llcp_sock = NULL;
  
  out:
  	read_unlock(&local->connecting_sockets.lock);

  	return llcp_sock;
  }

  static struct nfc_llcp_sock *nfc_llcp_sock_get_sn(struct nfc_llcp_local *local,
  						  u8 *sn, size_t sn_len)
  {

  	struct nfc_llcp_sock *llcp_sock;

  	llcp_sock = nfc_llcp_sock_from_sn(local, sn, sn_len);

  	if (llcp_sock == NULL)
  		return NULL;

  	sock_hold(&llcp_sock->sk);
  
  	return llcp_sock;

  }

  static u8 *nfc_llcp_connect_sn(struct sk_buff *skb, size_t *sn_len)
  {
  	u8 *tlv = &skb->data[2], type, length;
  	size_t tlv_array_len = skb->len - LLCP_HEADER_SIZE, offset = 0;
  
  	while (offset < tlv_array_len) {
  		type = tlv[0];
  		length = tlv[1];
  
  		pr_debug("type 0x%x length %d
  ", type, length);
  
  		if (type == LLCP_TLV_SN) {
  			*sn_len = length;
  			return &tlv[2];
  		}
  
  		offset += length + 2;
  		tlv += length + 2;
  	}
  
  	return NULL;
  }

  static void nfc_llcp_recv_ui(struct nfc_llcp_local *local,
  			     struct sk_buff *skb)
  {
  	struct nfc_llcp_sock *llcp_sock;
  	struct nfc_llcp_ui_cb *ui_cb;
  	u8 dsap, ssap;
  
  	dsap = nfc_llcp_dsap(skb);
  	ssap = nfc_llcp_ssap(skb);
  
  	ui_cb = nfc_llcp_ui_skb_cb(skb);
  	ui_cb->dsap = dsap;
  	ui_cb->ssap = ssap;

  	pr_debug("%d %d
  ", dsap, ssap);
  
  	/* We're looking for a bound socket, not a client one */
  	llcp_sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
  	if (llcp_sock == NULL || llcp_sock->sk.sk_type != SOCK_DGRAM)
  		return;
  
  	/* There is no sequence with UI frames */
  	skb_pull(skb, LLCP_HEADER_SIZE);

  	if (!sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
  		/*
  		 * UI frames will be freed from the socket layer, so we
  		 * need to keep them alive until someone receives them.
  		 */
  		skb_get(skb);
  	} else {
  		pr_err("Receive queue is full
  ");

  	}
  
  	nfc_llcp_sock_put(llcp_sock);
  }

  static void nfc_llcp_recv_connect(struct nfc_llcp_local *local,

  				  struct sk_buff *skb)

  {
  	struct sock *new_sk, *parent;
  	struct nfc_llcp_sock *sock, *new_sock;

  	u8 dsap, ssap, reason;

  
  	dsap = nfc_llcp_dsap(skb);
  	ssap = nfc_llcp_ssap(skb);
  
  	pr_debug("%d %d
  ", dsap, ssap);

  	if (dsap != LLCP_SAP_SDP) {

  		sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
  		if (sock == NULL || sock->sk.sk_state != LLCP_LISTEN) {

  			reason = LLCP_DM_NOBOUND;
  			goto fail;
  		}

  	} else {
  		u8 *sn;
  		size_t sn_len;
  
  		sn = nfc_llcp_connect_sn(skb, &sn_len);
  		if (sn == NULL) {
  			reason = LLCP_DM_NOBOUND;
  			goto fail;
  		}
  
  		pr_debug("Service name length %zu
  ", sn_len);

  		sock = nfc_llcp_sock_get_sn(local, sn, sn_len);
  		if (sock == NULL) {
  			reason = LLCP_DM_NOBOUND;
  			goto fail;

  		}

  	}

  	lock_sock(&sock->sk);

  	parent = &sock->sk;
  
  	if (sk_acceptq_is_full(parent)) {
  		reason = LLCP_DM_REJ;
  		release_sock(&sock->sk);
  		sock_put(&sock->sk);
  		goto fail;
  	}

  	if (sock->ssap == LLCP_SDP_UNBOUND) {
  		u8 ssap = nfc_llcp_reserve_sdp_ssap(local);
  
  		pr_debug("First client, reserving %d
  ", ssap);
  
  		if (ssap == LLCP_SAP_MAX) {
  			reason = LLCP_DM_REJ;
  			release_sock(&sock->sk);
  			sock_put(&sock->sk);
  			goto fail;
  		}
  
  		sock->ssap = ssap;
  	}

  	new_sk = nfc_llcp_sock_alloc(NULL, parent->sk_type, GFP_ATOMIC, 0);

  	if (new_sk == NULL) {
  		reason = LLCP_DM_REJ;
  		release_sock(&sock->sk);
  		sock_put(&sock->sk);
  		goto fail;
  	}
  
  	new_sock = nfc_llcp_sock(new_sk);
  	new_sock->dev = local->dev;

  	new_sock->local = nfc_llcp_local_get(local);

  	new_sock->rw = sock->rw;
  	new_sock->miux = sock->miux;

  	new_sock->nfc_protocol = sock->nfc_protocol;

  	new_sock->dsap = ssap;

  	new_sock->target_idx = local->target_idx;

  	new_sock->parent = parent;

  	new_sock->ssap = sock->ssap;
  	if (sock->ssap < LLCP_LOCAL_NUM_SAP && sock->ssap >= LLCP_WKS_NUM_SAP) {
  		atomic_t *client_count;
  
  		pr_debug("reserved_ssap %d for %p
  ", sock->ssap, new_sock);
  
  		client_count =
  			&local->local_sdp_cnt[sock->ssap - LLCP_WKS_NUM_SAP];
  
  		atomic_inc(client_count);
  		new_sock->reserved_ssap = sock->ssap;
  	}

  	nfc_llcp_parse_connection_tlv(new_sock, &skb->data[LLCP_HEADER_SIZE],
  				      skb->len - LLCP_HEADER_SIZE);

  	pr_debug("new sock %p sk %p
  ", new_sock, &new_sock->sk);

  	nfc_llcp_sock_link(&local->sockets, new_sk);

  
  	nfc_llcp_accept_enqueue(&sock->sk, new_sk);
  
  	nfc_get_device(local->dev->idx);
  
  	new_sk->sk_state = LLCP_CONNECTED;
  
  	/* Wake the listening processes */

  	parent->sk_data_ready(parent);

  
  	/* Send CC */
  	nfc_llcp_send_cc(new_sock);
  
  	release_sock(&sock->sk);
  	sock_put(&sock->sk);
  
  	return;
  
  fail:
  	/* Send DM */
  	nfc_llcp_send_dm(local, dsap, ssap, reason);

  }

  int nfc_llcp_queue_i_frames(struct nfc_llcp_sock *sock)

  {

  	int nr_frames = 0;

  	struct nfc_llcp_local *local = sock->local;
  
  	pr_debug("Remote ready %d tx queue len %d remote rw %d",

  		 sock->remote_ready, skb_queue_len(&sock->tx_pending_queue),

  		 sock->remote_rw);

  
  	/* Try to queue some I frames for transmission */
  	while (sock->remote_ready &&

  	       skb_queue_len(&sock->tx_pending_queue) < sock->remote_rw) {

  		struct sk_buff *pdu;

  
  		pdu = skb_dequeue(&sock->tx_queue);
  		if (pdu == NULL)
  			break;
  
  		/* Update N(S)/N(R) */
  		nfc_llcp_set_nrns(sock, pdu);

  		skb_queue_tail(&local->tx_queue, pdu);

  		nr_frames++;

  	}

  
  	return nr_frames;

  }

  static void nfc_llcp_recv_hdlc(struct nfc_llcp_local *local,

  			       struct sk_buff *skb)

  {
  	struct nfc_llcp_sock *llcp_sock;
  	struct sock *sk;
  	u8 dsap, ssap, ptype, ns, nr;
  
  	ptype = nfc_llcp_ptype(skb);
  	dsap = nfc_llcp_dsap(skb);
  	ssap = nfc_llcp_ssap(skb);
  	ns = nfc_llcp_ns(skb);
  	nr = nfc_llcp_nr(skb);
  
  	pr_debug("%d %d R %d S %d
  ", dsap, ssap, nr, ns);
  
  	llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
  	if (llcp_sock == NULL) {
  		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
  		return;
  	}
  
  	sk = &llcp_sock->sk;
  	lock_sock(sk);
  	if (sk->sk_state == LLCP_CLOSED) {
  		release_sock(sk);
  		nfc_llcp_sock_put(llcp_sock);
  	}

  	/* Pass the payload upstream */
  	if (ptype == LLCP_PDU_I) {
  		pr_debug("I frame, queueing on %p
  ", &llcp_sock->sk);

  		if (ns == llcp_sock->recv_n)
  			llcp_sock->recv_n = (llcp_sock->recv_n + 1) % 16;
  		else
  			pr_err("Received out of sequence I PDU
  ");

  		skb_pull(skb, LLCP_HEADER_SIZE + LLCP_SEQUENCE_SIZE);

  		if (!sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
  			/*
  			 * I frames will be freed from the socket layer, so we
  			 * need to keep them alive until someone receives them.
  			 */
  			skb_get(skb);
  		} else {
  			pr_err("Receive queue is full
  ");

  		}
  	}
  
  	/* Remove skbs from the pending queue */
  	if (llcp_sock->send_ack_n != nr) {
  		struct sk_buff *s, *tmp;

  		u8 n;

  
  		llcp_sock->send_ack_n = nr;

  		/* Remove and free all skbs until ns == nr */
  		skb_queue_walk_safe(&llcp_sock->tx_pending_queue, s, tmp) {

  			n = nfc_llcp_ns(s);

  			skb_unlink(s, &llcp_sock->tx_pending_queue);
  			kfree_skb(s);

  			if (n == nr)

  				break;
  		}
  
  		/* Re-queue the remaining skbs for transmission */
  		skb_queue_reverse_walk_safe(&llcp_sock->tx_pending_queue,
  					    s, tmp) {
  			skb_unlink(s, &llcp_sock->tx_pending_queue);
  			skb_queue_head(&local->tx_queue, s);
  		}

  	}

  	if (ptype == LLCP_PDU_RR)
  		llcp_sock->remote_ready = true;

  	else if (ptype == LLCP_PDU_RNR)

  		llcp_sock->remote_ready = false;

  	if (nfc_llcp_queue_i_frames(llcp_sock) == 0 && ptype == LLCP_PDU_I)

  		nfc_llcp_send_rr(llcp_sock);

  
  	release_sock(sk);
  	nfc_llcp_sock_put(llcp_sock);
  }
  
  static void nfc_llcp_recv_disc(struct nfc_llcp_local *local,

  			       struct sk_buff *skb)

  {
  	struct nfc_llcp_sock *llcp_sock;
  	struct sock *sk;
  	u8 dsap, ssap;
  
  	dsap = nfc_llcp_dsap(skb);
  	ssap = nfc_llcp_ssap(skb);

  	if ((dsap == 0) && (ssap == 0)) {
  		pr_debug("Connection termination");
  		nfc_dep_link_down(local->dev);
  		return;
  	}

  	llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
  	if (llcp_sock == NULL) {
  		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
  		return;
  	}
  
  	sk = &llcp_sock->sk;
  	lock_sock(sk);

  
  	nfc_llcp_socket_purge(llcp_sock);

  	if (sk->sk_state == LLCP_CLOSED) {
  		release_sock(sk);
  		nfc_llcp_sock_put(llcp_sock);
  	}

  	if (sk->sk_state == LLCP_CONNECTED) {
  		nfc_put_device(local->dev);
  		sk->sk_state = LLCP_CLOSED;
  		sk->sk_state_change(sk);
  	}
  
  	nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_DISC);
  
  	release_sock(sk);
  	nfc_llcp_sock_put(llcp_sock);
  }

  static void nfc_llcp_recv_cc(struct nfc_llcp_local *local, struct sk_buff *skb)

  {
  	struct nfc_llcp_sock *llcp_sock;

  	struct sock *sk;

  	u8 dsap, ssap;

  	dsap = nfc_llcp_dsap(skb);
  	ssap = nfc_llcp_ssap(skb);

  	llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);

  	if (llcp_sock == NULL) {
  		pr_err("Invalid CC
  ");
  		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
  
  		return;
  	}

  	sk = &llcp_sock->sk;

  	/* Unlink from connecting and link to the client array */
  	nfc_llcp_sock_unlink(&local->connecting_sockets, sk);
  	nfc_llcp_sock_link(&local->sockets, sk);
  	llcp_sock->dsap = ssap;

  	nfc_llcp_parse_connection_tlv(llcp_sock, &skb->data[LLCP_HEADER_SIZE],
  				      skb->len - LLCP_HEADER_SIZE);

  	sk->sk_state = LLCP_CONNECTED;
  	sk->sk_state_change(sk);

  	nfc_llcp_sock_put(llcp_sock);
  }

  static void nfc_llcp_recv_dm(struct nfc_llcp_local *local, struct sk_buff *skb)
  {
  	struct nfc_llcp_sock *llcp_sock;
  	struct sock *sk;
  	u8 dsap, ssap, reason;
  
  	dsap = nfc_llcp_dsap(skb);
  	ssap = nfc_llcp_ssap(skb);
  	reason = skb->data[2];
  
  	pr_debug("%d %d reason %d
  ", ssap, dsap, reason);
  
  	switch (reason) {
  	case LLCP_DM_NOBOUND:
  	case LLCP_DM_REJ:
  		llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
  		break;
  
  	default:
  		llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
  		break;
  	}
  
  	if (llcp_sock == NULL) {

  		pr_debug("Already closed
  ");

  		return;
  	}
  
  	sk = &llcp_sock->sk;
  
  	sk->sk_err = ENXIO;
  	sk->sk_state = LLCP_CLOSED;
  	sk->sk_state_change(sk);
  
  	nfc_llcp_sock_put(llcp_sock);

  }

  static void nfc_llcp_recv_snl(struct nfc_llcp_local *local,
  			      struct sk_buff *skb)
  {
  	struct nfc_llcp_sock *llcp_sock;
  	u8 dsap, ssap, *tlv, type, length, tid, sap;
  	u16 tlv_len, offset;
  	char *service_name;
  	size_t service_name_len;

  	struct nfc_llcp_sdp_tlv *sdp;
  	HLIST_HEAD(llc_sdres_list);
  	size_t sdres_tlvs_len;

  	HLIST_HEAD(nl_sdres_list);

  
  	dsap = nfc_llcp_dsap(skb);
  	ssap = nfc_llcp_ssap(skb);
  
  	pr_debug("%d %d
  ", dsap, ssap);
  
  	if (dsap != LLCP_SAP_SDP || ssap != LLCP_SAP_SDP) {
  		pr_err("Wrong SNL SAP
  ");
  		return;
  	}
  
  	tlv = &skb->data[LLCP_HEADER_SIZE];
  	tlv_len = skb->len - LLCP_HEADER_SIZE;
  	offset = 0;

  	sdres_tlvs_len = 0;

  	while (offset < tlv_len) {

  		type = tlv[0];
  		length = tlv[1];
  
  		switch (type) {
  		case LLCP_TLV_SDREQ:
  			tid = tlv[2];
  			service_name = (char *) &tlv[3];
  			service_name_len = length - 1;

  			pr_debug("Looking for %.16s
  ", service_name);

  
  			if (service_name_len == strlen("urn:nfc:sn:sdp") &&
  			    !strncmp(service_name, "urn:nfc:sn:sdp",
  				     service_name_len)) {
  				sap = 1;

  				goto add_snl;

  			}
  
  			llcp_sock = nfc_llcp_sock_from_sn(local, service_name,
  							  service_name_len);
  			if (!llcp_sock) {
  				sap = 0;

  				goto add_snl;

  			}
  
  			/*
  			 * We found a socket but its ssap has not been reserved
  			 * yet. We need to assign it for good and send a reply.
  			 * The ssap will be freed when the socket is closed.
  			 */
  			if (llcp_sock->ssap == LLCP_SDP_UNBOUND) {
  				atomic_t *client_count;
  
  				sap = nfc_llcp_reserve_sdp_ssap(local);
  
  				pr_debug("Reserving %d
  ", sap);
  
  				if (sap == LLCP_SAP_MAX) {
  					sap = 0;

  					goto add_snl;

  				}
  
  				client_count =
  					&local->local_sdp_cnt[sap -
  							      LLCP_WKS_NUM_SAP];
  
  				atomic_inc(client_count);
  
  				llcp_sock->ssap = sap;
  				llcp_sock->reserved_ssap = sap;

  			} else {

  				sap = llcp_sock->ssap;

  			}

  			pr_debug("%p %d
  ", llcp_sock, sap);

  add_snl:
  			sdp = nfc_llcp_build_sdres_tlv(tid, sap);
  			if (sdp == NULL)
  				goto exit;
  
  			sdres_tlvs_len += sdp->tlv_len;
  			hlist_add_head(&sdp->node, &llc_sdres_list);

  			break;

  		case LLCP_TLV_SDRES:
  			mutex_lock(&local->sdreq_lock);
  
  			pr_debug("LLCP_TLV_SDRES: searching tid %d
  ", tlv[2]);
  
  			hlist_for_each_entry(sdp, &local->pending_sdreqs, node) {
  				if (sdp->tid != tlv[2])
  					continue;
  
  				sdp->sap = tlv[3];
  
  				pr_debug("Found: uri=%s, sap=%d
  ",
  					 sdp->uri, sdp->sap);
  
  				hlist_del(&sdp->node);
  
  				hlist_add_head(&sdp->node, &nl_sdres_list);
  
  				break;
  			}
  
  			mutex_unlock(&local->sdreq_lock);
  			break;

  		default:
  			pr_err("Invalid SNL tlv value 0x%x
  ", type);
  			break;
  		}
  
  		offset += length + 2;
  		tlv += length + 2;
  	}

  
  exit:

  	if (!hlist_empty(&nl_sdres_list))
  		nfc_genl_llc_send_sdres(local->dev, &nl_sdres_list);

  	if (!hlist_empty(&llc_sdres_list))
  		nfc_llcp_send_snl_sdres(local, &llc_sdres_list, sdres_tlvs_len);

  }

  static void nfc_llcp_recv_agf(struct nfc_llcp_local *local, struct sk_buff *skb)

  {

  	u8 ptype;
  	u16 pdu_len;
  	struct sk_buff *new_skb;

  	if (skb->len <= LLCP_HEADER_SIZE) {
  		pr_err("Malformed AGF PDU
  ");

  		return;
  	}

  	skb_pull(skb, LLCP_HEADER_SIZE);
  
  	while (skb->len > LLCP_AGF_PDU_HEADER_SIZE) {
  		pdu_len = skb->data[0] << 8 | skb->data[1];
  
  		skb_pull(skb, LLCP_AGF_PDU_HEADER_SIZE);
  
  		if (pdu_len < LLCP_HEADER_SIZE || pdu_len > skb->len) {
  			pr_err("Malformed AGF PDU
  ");
  			return;
  		}
  
  		ptype = nfc_llcp_ptype(skb);
  
  		if (ptype == LLCP_PDU_SYMM || ptype == LLCP_PDU_AGF)
  			goto next;
  
  		new_skb = nfc_alloc_recv_skb(pdu_len, GFP_KERNEL);
  		if (new_skb == NULL) {
  			pr_err("Could not allocate PDU
  ");
  			return;
  		}

  		skb_put_data(new_skb, skb->data, pdu_len);

  
  		nfc_llcp_rx_skb(local, new_skb);
  
  		kfree_skb(new_skb);
  next:
  		skb_pull(skb, pdu_len);
  	}
  }
  
  static void nfc_llcp_rx_skb(struct nfc_llcp_local *local, struct sk_buff *skb)
  {
  	u8 dsap, ssap, ptype;

  	ptype = nfc_llcp_ptype(skb);
  	dsap = nfc_llcp_dsap(skb);
  	ssap = nfc_llcp_ssap(skb);
  
  	pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x
  ", ptype, dsap, ssap);

  	if (ptype != LLCP_PDU_SYMM)

  		print_hex_dump_debug("LLCP Rx: ", DUMP_PREFIX_OFFSET, 16, 1,
  				     skb->data, skb->len, true);

  	switch (ptype) {
  	case LLCP_PDU_SYMM:
  		pr_debug("SYMM
  ");
  		break;

  	case LLCP_PDU_UI:
  		pr_debug("UI
  ");
  		nfc_llcp_recv_ui(local, skb);
  		break;

  	case LLCP_PDU_CONNECT:
  		pr_debug("CONNECT
  ");
  		nfc_llcp_recv_connect(local, skb);
  		break;
  
  	case LLCP_PDU_DISC:
  		pr_debug("DISC
  ");
  		nfc_llcp_recv_disc(local, skb);
  		break;
  
  	case LLCP_PDU_CC:
  		pr_debug("CC
  ");
  		nfc_llcp_recv_cc(local, skb);
  		break;

  	case LLCP_PDU_DM:
  		pr_debug("DM
  ");
  		nfc_llcp_recv_dm(local, skb);
  		break;

  	case LLCP_PDU_SNL:
  		pr_debug("SNL
  ");
  		nfc_llcp_recv_snl(local, skb);
  		break;

  	case LLCP_PDU_I:
  	case LLCP_PDU_RR:

  	case LLCP_PDU_RNR:

  		pr_debug("I frame
  ");
  		nfc_llcp_recv_hdlc(local, skb);
  		break;

  	case LLCP_PDU_AGF:
  		pr_debug("AGF frame
  ");
  		nfc_llcp_recv_agf(local, skb);
  		break;

  	}

  }
  
  static void nfc_llcp_rx_work(struct work_struct *work)
  {
  	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
  						    rx_work);
  	struct sk_buff *skb;
  
  	skb = local->rx_pending;
  	if (skb == NULL) {
  		pr_debug("No pending SKB
  ");
  		return;
  	}
  
  	__net_timestamp(skb);

  	nfc_llcp_send_to_raw_sock(local, skb, NFC_DIRECTION_RX);

  
  	nfc_llcp_rx_skb(local, skb);

  	schedule_work(&local->tx_work);

  	kfree_skb(local->rx_pending);
  	local->rx_pending = NULL;

  }

  static void __nfc_llcp_recv(struct nfc_llcp_local *local, struct sk_buff *skb)
  {
  	local->rx_pending = skb;
  	del_timer(&local->link_timer);
  	schedule_work(&local->rx_work);
  }

  void nfc_llcp_recv(void *data, struct sk_buff *skb, int err)
  {
  	struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
  
  	pr_debug("Received an LLCP PDU
  ");
  	if (err < 0) {

  		pr_err("err %d
  ", err);

  		return;
  	}

  	__nfc_llcp_recv(local, skb);

  }

  int nfc_llcp_data_received(struct nfc_dev *dev, struct sk_buff *skb)
  {
  	struct nfc_llcp_local *local;
  
  	local = nfc_llcp_find_local(dev);

  	if (local == NULL) {
  		kfree_skb(skb);

  		return -ENODEV;

  	}

  	__nfc_llcp_recv(local, skb);

  
  	return 0;
  }

  void nfc_llcp_mac_is_down(struct nfc_dev *dev)
  {
  	struct nfc_llcp_local *local;
  
  	local = nfc_llcp_find_local(dev);
  	if (local == NULL)
  		return;

  	local->remote_miu = LLCP_DEFAULT_MIU;
  	local->remote_lto = LLCP_DEFAULT_LTO;

  	/* Close and purge all existing sockets */

  	nfc_llcp_socket_release(local, true, 0);

  }
  
  void nfc_llcp_mac_is_up(struct nfc_dev *dev, u32 target_idx,
  			u8 comm_mode, u8 rf_mode)
  {
  	struct nfc_llcp_local *local;
  
  	pr_debug("rf mode %d
  ", rf_mode);
  
  	local = nfc_llcp_find_local(dev);
  	if (local == NULL)
  		return;
  
  	local->target_idx = target_idx;
  	local->comm_mode = comm_mode;
  	local->rf_mode = rf_mode;
  
  	if (rf_mode == NFC_RF_INITIATOR) {
  		pr_debug("Queueing Tx work
  ");

  		schedule_work(&local->tx_work);

  	} else {
  		mod_timer(&local->link_timer,

  			  jiffies + msecs_to_jiffies(local->remote_lto));

  	}
  }
  
  int nfc_llcp_register_device(struct nfc_dev *ndev)
  {

  	struct nfc_llcp_local *local;

  
  	local = kzalloc(sizeof(struct nfc_llcp_local), GFP_KERNEL);
  	if (local == NULL)
  		return -ENOMEM;
  
  	local->dev = ndev;
  	INIT_LIST_HEAD(&local->list);

  	kref_init(&local->ref);

  	mutex_init(&local->sdp_lock);

  	init_timer(&local->link_timer);
  	local->link_timer.data = (unsigned long) local;
  	local->link_timer.function = nfc_llcp_symm_timer;
  
  	skb_queue_head_init(&local->tx_queue);
  	INIT_WORK(&local->tx_work, nfc_llcp_tx_work);

  
  	local->rx_pending = NULL;
  	INIT_WORK(&local->rx_work, nfc_llcp_rx_work);

  
  	INIT_WORK(&local->timeout_work, nfc_llcp_timeout_work);

  	rwlock_init(&local->sockets.lock);
  	rwlock_init(&local->connecting_sockets.lock);

  	rwlock_init(&local->raw_sockets.lock);

  	local->lto = 150; /* 1500 ms */
  	local->rw = LLCP_MAX_RW;
  	local->miux = cpu_to_be16(LLCP_MAX_MIUX);

  	local->local_wks = 0x1; /* LLC Link Management */

  	nfc_llcp_build_gb(local);
  
  	local->remote_miu = LLCP_DEFAULT_MIU;
  	local->remote_lto = LLCP_DEFAULT_LTO;

  	mutex_init(&local->sdreq_lock);
  	INIT_HLIST_HEAD(&local->pending_sdreqs);

  	init_timer(&local->sdreq_timer);
  	local->sdreq_timer.data = (unsigned long) local;
  	local->sdreq_timer.function = nfc_llcp_sdreq_timer;
  	INIT_WORK(&local->sdreq_timeout_work, nfc_llcp_sdreq_timeout_work);

  	list_add(&local->list, &llcp_devices);

  
  	return 0;

  }
  
  void nfc_llcp_unregister_device(struct nfc_dev *dev)
  {
  	struct nfc_llcp_local *local = nfc_llcp_find_local(dev);
  
  	if (local == NULL) {
  		pr_debug("No such device
  ");
  		return;
  	}

  	local_cleanup(local);

  	nfc_llcp_local_put(local);

  }
  
  int __init nfc_llcp_init(void)
  {

  	return nfc_llcp_sock_init();
  }
  
  void nfc_llcp_exit(void)
  {
  	nfc_llcp_sock_exit();
  }