path: root/net/nfc/llcp/llcp.c

/*
 * Copyright (C) 2011  Intel Corporation. All rights reserved.
 *
 * 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, write to the
 * Free Software Foundation, Inc.,
 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#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 struct list_head llcp_devices;

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);
}

static void nfc_llcp_socket_release(struct nfc_llcp_local *local)
{
	struct sock *sk;
	struct hlist_node *node, *tmp;
	struct nfc_llcp_sock *llcp_sock;

	write_lock(&local->sockets.lock);

	sk_for_each_safe(sk, node, tmp, &local->sockets.head) {
		llcp_sock = nfc_llcp_sock(sk);

		lock_sock(sk);

		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;
				lock_sock(accept_sk);

				nfc_llcp_accept_unlink(accept_sk);

				accept_sk->sk_state = LLCP_CLOSED;

				release_sock(accept_sk);

				sock_orphan(accept_sk);
			}
		}

		sk->sk_state = LLCP_CLOSED;

		release_sock(sk);

		sock_orphan(sk);

		sk_del_node_init(sk);
	}

	write_unlock(&local->sockets.lock);
}

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

	return local;
}

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);
	nfc_llcp_socket_release(local);
	del_timer_sync(&local->link_timer);
	skb_queue_purge(&local->tx_queue);
	destroy_workqueue(local->tx_wq);
	destroy_workqueue(local->rx_wq);
	kfree_skb(local->rx_pending);
	kfree(local);
}

int nfc_llcp_local_put(struct nfc_llcp_local *local)
{
	WARN_ON(local == NULL);

	if (local == NULL)
		return 0;

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

static void nfc_llcp_clear_sdp(struct nfc_llcp_local *local)
{
	mutex_lock(&local->sdp_lock);

	local->local_wks = 0;
	local->local_sdp = 0;
	local->local_sap = 0;

	mutex_unlock(&local->sdp_lock);
}

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