Bluetooth: Initial work for L2CAP split.

This patch tries to do the minimal to move l2cap_sock_create() and its
dependencies to l2cap_sock.c. It create a API to initialize and cleanup
the L2CAP sockets from l2cap_core.c through l2cap_init_sockets() and
l2cap_cleanup_sockets().

Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
new file mode 100644
index 0000000..6ea1894
--- /dev/null
+++ b/net/bluetooth/l2cap_sock.c
@@ -0,0 +1,213 @@
+/*
+   BlueZ - Bluetooth protocol stack for Linux
+   Copyright (C) 2000-2001 Qualcomm Incorporated
+   Copyright (C) 2009-2010 Gustavo F. Padovan <gustavo@padovan.org>
+   Copyright (C) 2010 Google Inc.
+
+   Written 2000,2001 by Maxim Krasnyansky <maxk@qualcomm.com>
+
+   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.
+*/
+
+/* Bluetooth L2CAP sockets. */
+
+#include <net/bluetooth/bluetooth.h>
+#include <net/bluetooth/l2cap.h>
+
+static void l2cap_sock_timeout(unsigned long arg)
+{
+	struct sock *sk = (struct sock *) arg;
+	int reason;
+
+	BT_DBG("sock %p state %d", sk, sk->sk_state);
+
+	bh_lock_sock(sk);
+
+	if (sock_owned_by_user(sk)) {
+		/* sk is owned by user. Try again later */
+		l2cap_sock_set_timer(sk, HZ / 5);
+		bh_unlock_sock(sk);
+		sock_put(sk);
+		return;
+	}
+
+	if (sk->sk_state == BT_CONNECTED || sk->sk_state == BT_CONFIG)
+		reason = ECONNREFUSED;
+	else if (sk->sk_state == BT_CONNECT &&
+				l2cap_pi(sk)->sec_level != BT_SECURITY_SDP)
+		reason = ECONNREFUSED;
+	else
+		reason = ETIMEDOUT;
+
+	__l2cap_sock_close(sk, reason);
+
+	bh_unlock_sock(sk);
+
+	l2cap_sock_kill(sk);
+	sock_put(sk);
+}
+
+
+static void l2cap_sock_destruct(struct sock *sk)
+{
+	BT_DBG("sk %p", sk);
+
+	skb_queue_purge(&sk->sk_receive_queue);
+	skb_queue_purge(&sk->sk_write_queue);
+}
+
+void l2cap_sock_init(struct sock *sk, struct sock *parent)
+{
+	struct l2cap_pinfo *pi = l2cap_pi(sk);
+
+	BT_DBG("sk %p", sk);
+
+	if (parent) {
+		sk->sk_type = parent->sk_type;
+		bt_sk(sk)->defer_setup = bt_sk(parent)->defer_setup;
+
+		pi->imtu = l2cap_pi(parent)->imtu;
+		pi->omtu = l2cap_pi(parent)->omtu;
+		pi->conf_state = l2cap_pi(parent)->conf_state;
+		pi->mode = l2cap_pi(parent)->mode;
+		pi->fcs  = l2cap_pi(parent)->fcs;
+		pi->max_tx = l2cap_pi(parent)->max_tx;
+		pi->tx_win = l2cap_pi(parent)->tx_win;
+		pi->sec_level = l2cap_pi(parent)->sec_level;
+		pi->role_switch = l2cap_pi(parent)->role_switch;
+		pi->force_reliable = l2cap_pi(parent)->force_reliable;
+		pi->flushable = l2cap_pi(parent)->flushable;
+	} else {
+		pi->imtu = L2CAP_DEFAULT_MTU;
+		pi->omtu = 0;
+		if (!disable_ertm && sk->sk_type == SOCK_STREAM) {
+			pi->mode = L2CAP_MODE_ERTM;
+			pi->conf_state |= L2CAP_CONF_STATE2_DEVICE;
+		} else {
+			pi->mode = L2CAP_MODE_BASIC;
+		}
+		pi->max_tx = L2CAP_DEFAULT_MAX_TX;
+		pi->fcs  = L2CAP_FCS_CRC16;
+		pi->tx_win = L2CAP_DEFAULT_TX_WINDOW;
+		pi->sec_level = BT_SECURITY_LOW;
+		pi->role_switch = 0;
+		pi->force_reliable = 0;
+		pi->flushable = BT_FLUSHABLE_OFF;
+	}
+
+	/* Default config options */
+	pi->conf_len = 0;
+	pi->flush_to = L2CAP_DEFAULT_FLUSH_TO;
+	skb_queue_head_init(TX_QUEUE(sk));
+	skb_queue_head_init(SREJ_QUEUE(sk));
+	skb_queue_head_init(BUSY_QUEUE(sk));
+	INIT_LIST_HEAD(SREJ_LIST(sk));
+}
+
+static struct proto l2cap_proto = {
+	.name		= "L2CAP",
+	.owner		= THIS_MODULE,
+	.obj_size	= sizeof(struct l2cap_pinfo)
+};
+
+struct sock *l2cap_sock_alloc(struct net *net, struct socket *sock, int proto, gfp_t prio)
+{
+	struct sock *sk;
+
+	sk = sk_alloc(net, PF_BLUETOOTH, prio, &l2cap_proto);
+	if (!sk)
+		return NULL;
+
+	sock_init_data(sock, sk);
+	INIT_LIST_HEAD(&bt_sk(sk)->accept_q);
+
+	sk->sk_destruct = l2cap_sock_destruct;
+	sk->sk_sndtimeo = msecs_to_jiffies(L2CAP_CONN_TIMEOUT);
+
+	sock_reset_flag(sk, SOCK_ZAPPED);
+
+	sk->sk_protocol = proto;
+	sk->sk_state = BT_OPEN;
+
+	setup_timer(&sk->sk_timer, l2cap_sock_timeout, (unsigned long) sk);
+
+	bt_sock_link(&l2cap_sk_list, sk);
+	return sk;
+}
+
+static int l2cap_sock_create(struct net *net, struct socket *sock, int protocol,
+			     int kern)
+{
+	struct sock *sk;
+
+	BT_DBG("sock %p", sock);
+
+	sock->state = SS_UNCONNECTED;
+
+	if (sock->type != SOCK_SEQPACKET && sock->type != SOCK_STREAM &&
+			sock->type != SOCK_DGRAM && sock->type != SOCK_RAW)
+		return -ESOCKTNOSUPPORT;
+
+	if (sock->type == SOCK_RAW && !kern && !capable(CAP_NET_RAW))
+		return -EPERM;
+
+	sock->ops = &l2cap_sock_ops;
+
+	sk = l2cap_sock_alloc(net, sock, protocol, GFP_ATOMIC);
+	if (!sk)
+		return -ENOMEM;
+
+	l2cap_sock_init(sk, NULL);
+	return 0;
+}
+
+static const struct net_proto_family l2cap_sock_family_ops = {
+	.family	= PF_BLUETOOTH,
+	.owner	= THIS_MODULE,
+	.create	= l2cap_sock_create,
+};
+
+int __init l2cap_init_sockets(void)
+{
+       int err;
+
+       err = proto_register(&l2cap_proto, 0);
+       if (err < 0)
+               return err;
+
+       err = bt_sock_register(BTPROTO_L2CAP, &l2cap_sock_family_ops);
+       if (err < 0)
+               goto error;
+
+       BT_INFO("L2CAP socket layer initialized");
+
+       return 0;
+
+error:
+       BT_ERR("L2CAP socket registration failed");
+       proto_unregister(&l2cap_proto);
+       return err;
+}
+
+void l2cap_cleanup_sockets(void)
+{
+       if (bt_sock_unregister(BTPROTO_L2CAP) < 0)
+               BT_ERR("L2CAP socket unregistration failed");
+
+       proto_unregister(&l2cap_proto);
+}