path: root/net/bluetooth/rfcomm/sock.c

/*
   RFCOMM implementation for Linux Bluetooth stack (BlueZ).
   Copyright (C) 2002 Maxim Krasnyansky <maxk@qualcomm.com>
   Copyright (C) 2002 Marcel Holtmann <marcel@holtmann.org>

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License version 2 as
   published by the Free Software Foundation;

   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
   OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
   IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
   CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
   WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
   ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

   ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
   COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
   SOFTWARE IS DISCLAIMED.
*/

/*
 * RFCOMM sockets.
 */

#include <linux/module.h>

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/poll.h>
#include <linux/fcntl.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/socket.h>
#include <linux/skbuff.h>
#include <linux/list.h>
#include <linux/device.h>
#include <net/sock.h>

#include <asm/system.h>
#include <asm/uaccess.h>

#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>
#include <net/bluetooth/l2cap.h>
#include <net/bluetooth/rfcomm.h>

static const struct proto_ops rfcomm_sock_ops;

static struct bt_sock_list rfcomm_sk_list = {
	.lock = __RW_LOCK_UNLOCKED(rfcomm_sk_list.lock)
};

static void rfcomm_sock_close(struct sock *sk);
static void rfcomm_sock_kill(struct sock *sk);

/* ---- DLC callbacks ----
 *
 * called under rfcomm_dlc_lock()
 */
static void rfcomm_sk_data_ready(struct rfcomm_dlc *d, struct sk_buff *skb)
{
	struct sock *sk = d->owner;
	if (!sk)
		return;

	atomic_add(skb->len, &sk->sk_rmem_alloc);
	skb_queue_tail(&sk->sk_receive_queue, skb);
	sk->sk_data_ready(sk, skb->len);

	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
		rfcomm_dlc_throttle(d);
}

static void rfcomm_sk_state_change(struct rfcomm_dlc *d, int err)
{
	struct sock *sk = d->owner, *parent;
	if (!sk)
		return;

	BT_DBG("dlc %p state %ld err %d", d, d->state, err);

	bh_lock_sock(sk);

	if (err)
		sk->sk_err = err;

	sk->sk_state = d->state;

	parent = bt_sk(sk)->parent;
	if (parent) {
		if (d->state == BT_CLOSED) {
			sock_set_flag(sk, SOCK_ZAPPED);
			bt_accept_unlink(sk);
		}
		parent->sk_data_ready(parent, 0);
	} else {
		if (d->state == BT_CONNECTED)
			rfcomm_session_getaddr(d->session, &bt_sk(sk)->src, NULL);
		sk->sk_state_change(sk);
	}

	bh_unlock_sock(sk);

	if (parent && sock_flag(sk, SOCK_ZAPPED)) {
		/* We have to drop DLC lock here, otherwise
		 * rfcomm_sock_destruct() will dead lock. */
		rfcomm_dlc_unlock(d);
		rfcomm_sock_kill(sk);
		rfcomm_dlc_lock(d);
	}
}

/* ---- Socket functions ---- */
static struct sock *__rfcomm_get_sock_by_addr(u8 channel, bdaddr_t *src)
{
	struct sock *sk = NULL;
	struct hlist_node *node;

	sk_for_each(sk, node, &rfcomm_sk_list.head) {
		if (rfcomm_pi(sk)->channel == channel &&
				!bacmp(&bt_sk(sk)->src, src))
			break;
	}

	return node ? sk : NULL;
}

/* Find socket with channel and source bdaddr.
 * Returns closest match.
 */
static struct sock *__rfcomm_get_sock_by_channel(int state, u8 channel, bdaddr_t *src)
{
	struct sock *sk = NULL, *sk1 = NULL;
	struct hlist_node *node;

	sk_for_each(sk, node, &rfcomm_sk_list.head) {
		if (state && sk->sk_state != state)
			continue;

		if (rfcomm_pi(sk)->channel == channel) {
			/* Exact match. */
			if (!bacmp(&bt_sk(sk)->src, src))
				break;

			/* Closest match */
			if (!bacmp(&bt_sk(sk)->src, BDADDR_ANY))
				sk1 = sk;
		}
	}
	return node ? sk : sk1;
}

/* Find socket with given address (channel, src).
 * Returns locked socket */
static inline struct sock *rfcomm_get_sock_by_channel(int state, u8 channel, bdaddr_t *src)
{
	struct sock *s;
	read_lock(&rfcomm_sk_list.lock);
	s = __rfcomm_get_sock_by_channel(state,