Bluetooth: Add configuration support for ERTM and Streaming mode

Add support to config_req and config_rsp to configure ERTM and Streaming
mode. If the remote device specifies ERTM or Streaming mode, then the
same mode is proposed. Otherwise ERTM or Basic mode is used. And in case
of a state 2 device, the remote device should propose the same mode. If
not, then the channel gets disconnected.

Signed-off-by: Gustavo F. Padovan <gustavo@las.ic.unicamp.br>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
static int l2cap_sock_bind(struct socket *sock, struct sockaddr *addr, int alen)
{
	struct sock *sk = sock->sk;
	struct sockaddr_l2 la;
	int len, err = 0;

	BT_DBG("sk %p", sk);

	if (!addr || addr->sa_family != AF_BLUETOOTH)
		return -EINVAL;

	memset(&la, 0, sizeof(la));
	len = min_t(unsigned int, sizeof(la), alen);
	memcpy(&la, addr, len);

	if (la.l2_cid)
		return -EINVAL;

	lock_sock(sk);

	if (sk->sk_state != BT_OPEN) {
		err = -EBADFD;
		goto done;
	}

	if (la.l2_psm && __le16_to_cpu(la.l2_psm) < 0x1001 &&
				!capable(CAP_NET_BIND_SERVICE)) {
		err = -EACCES;
		goto done;
	}

	write_lock_bh(&l2cap_sk_list.lock);

	if (la.l2_psm && __l2cap_get_sock_by_addr(la.l2_psm, &la.l2_bdaddr)) {
		err = -EADDRINUSE;
	} else {
		/* Save source address */
		bacpy(&bt_sk(sk)->src, &la.l2_bdaddr);
		l2cap_pi(sk)->psm   = la.l2_psm;
		l2cap_pi(sk)->sport = la.l2_psm;
		sk->sk_state = BT_BOUND;

		if (__le16_to_cpu(la.l2_psm) == 0x0001 ||
					__le16_to_cpu(la.l2_psm) == 0x0003)
			l2cap_pi(sk)->sec_level = BT_SECURITY_SDP;
	}

	write_unlock_bh(&l2cap_sk_list.lock);

done:
	release_sock(sk);
	return err;
}

static int l2cap_sock_bind(struct socket *sock, struct sockaddr *addr, int alen)
{
	struct sock *sk = sock->sk;
	struct sockaddr_l2 la;
	int len, err = 0;

	BT_DBG("sk %p", sk);

	if (!addr || addr->sa_family != AF_BLUETOOTH)
		return -EINVAL;

	memset(&la, 0, sizeof(la));
	len = min_t(unsigned int, sizeof(la), alen);
	memcpy(&la, addr, len);

	if (la.l2_cid)
		return -EINVAL;

	lock_sock(sk);

	if (sk->sk_state != BT_OPEN) {
		err = -EBADFD;
		goto done;
	}

	if (la.l2_psm && __le16_to_cpu(la.l2_psm) < 0x1001 &&
				!capable(CAP_NET_BIND_SERVICE)) {
		err = -EACCES;
		goto done;
	}

	write_lock_bh(&l2cap_sk_list.lock);

	if (la.l2_psm && __l2cap_get_sock_by_addr(la.l2_psm, &la.l2_bdaddr)) {
		err = -EADDRINUSE;
	} else {
		/* Save source address */
		bacpy(&bt_sk(sk)->src, &la.l2_bdaddr);
		l2cap_pi(sk)->psm   = la.l2_psm;
		l2cap_pi(sk)->sport = la.l2_psm;
		sk->sk_state = BT_BOUND;

		if (__le16_to_cpu(la.l2_psm) == 0x0001 ||
					__le16_to_cpu(la.l2_psm) == 0x0003)
			l2cap_pi(sk)->sec_level = BT_SECURITY_SDP;
	}

	write_unlock_bh(&l2cap_sk_list.lock);

done:
	release_sock(sk);
	return err;
}
