l2cap.c

Linux嵌入式平台蓝牙协议栈软件

		if (err < 0)
			goto done;
	}

	sk->sk_max_ack_backlog = backlog;
	sk->sk_ack_backlog = 0;
	sk->sk_state = BT_LISTEN;

done:
	release_sock(sk);
	return err;
}

static int l2cap_sock_accept(struct socket *sock, struct socket *newsock, int flags)
{
	DECLARE_WAITQUEUE(wait, current);
	struct sock *sk = sock->sk, *nsk;
	long timeo;
	int err = 0;

	lock_sock(sk);

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

	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);

	BT_DBG("sk %p timeo %ld", sk, timeo);

	/* Wait for an incoming connection. (wake-one). */
	add_wait_queue_exclusive(sk->sk_sleep, &wait);
	while (!(nsk = bt_accept_dequeue(sk, newsock))) {
		set_current_state(TASK_INTERRUPTIBLE);
		if (!timeo) {
			err = -EAGAIN;
			break;
		}

		release_sock(sk);
		timeo = schedule_timeout(timeo);
		lock_sock(sk);

		if (sk->sk_state != BT_LISTEN) {
			err = -EBADFD;
			break;
		}

		if (signal_pending(current)) {
			err = sock_intr_errno(timeo);
			break;
		}
	}
	set_current_state(TASK_RUNNING);
	remove_wait_queue(sk->sk_sleep, &wait);

	if (err)
		goto done;

	newsock->state = SS_CONNECTED;

	BT_DBG("new socket %p", nsk);

done:
	release_sock(sk);
	return err;
}

static int l2cap_sock_getname(struct socket *sock, struct sockaddr *addr, int *len, int peer)
{
	struct sockaddr_l2 *la = (struct sockaddr_l2 *) addr;
	struct sock *sk = sock->sk;

	BT_DBG("sock %p, sk %p", sock, sk);

	addr->sa_family = AF_BLUETOOTH;
	*len = sizeof(struct sockaddr_l2);

	if (peer)
		bacpy(&la->l2_bdaddr, &bt_sk(sk)->dst);
	else
		bacpy(&la->l2_bdaddr, &bt_sk(sk)->src);

	la->l2_psm = l2cap_pi(sk)->psm;
	return 0;
}

static inline int l2cap_do_send(struct sock *sk, struct msghdr *msg, int len)
{
	struct l2cap_conn *conn = l2cap_pi(sk)->conn;
	struct sk_buff *skb, **frag;
	int err, hlen, count, sent=0;
	struct l2cap_hdr *lh;

	BT_DBG("sk %p len %d", sk, len);

	/* First fragment (with L2CAP header) */
	if (sk->sk_type == SOCK_DGRAM)
		hlen = L2CAP_HDR_SIZE + 2;
	else
		hlen = L2CAP_HDR_SIZE;

	count = min_t(unsigned int, (conn->mtu - hlen), len);

	skb = bt_skb_send_alloc(sk, hlen + count,
			msg->msg_flags & MSG_DONTWAIT, &err);
	if (!skb)
		return err;

	/* Create L2CAP header */
	lh = (struct l2cap_hdr *) skb_put(skb, L2CAP_HDR_SIZE);
	lh->cid = __cpu_to_le16(l2cap_pi(sk)->dcid);
	lh->len = __cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE));

	if (sk->sk_type == SOCK_DGRAM)
		put_unaligned(l2cap_pi(sk)->psm, (u16 *) skb_put(skb, 2));

	if (memcpy_fromiovec(skb_put(skb, count), msg->msg_iov, count)) {
		err = -EFAULT;
		goto fail;
	}

	sent += count;
	len  -= count;

	/* Continuation fragments (no L2CAP header) */
	frag = &skb_shinfo(skb)->frag_list;
	while (len) {
		count = min_t(unsigned int, conn->mtu, len);

		*frag = bt_skb_send_alloc(sk, count, msg->msg_flags & MSG_DONTWAIT, &err);
		if (!*frag)
			goto fail;
		
		if (memcpy_fromiovec(skb_put(*frag, count), msg->msg_iov, count)) {
			err = -EFAULT;
			goto fail;
		}

		sent += count;
		len  -= count;

		frag = &(*frag)->next;
	}

	if ((err = hci_send_acl(conn->hcon, skb, 0)) < 0)
		goto fail;

	return sent;

fail:
	kfree_skb(skb);
	return err;
}

static int l2cap_sock_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg, size_t len)
{
	struct sock *sk = sock->sk;
	int err = 0;

	BT_DBG("sock %p, sk %p", sock, sk);

	if (sk->sk_err)
		return sock_error(sk);

	if (msg->msg_flags & MSG_OOB)
		return -EOPNOTSUPP;

	/* Check outgoing MTU */
	if (len > l2cap_pi(sk)->omtu)
		return -EINVAL;

	lock_sock(sk);

	if (sk->sk_state == BT_CONNECTED)
		err = l2cap_do_send(sk, msg, len);
	else
		err = -ENOTCONN;

	release_sock(sk);
	return err;
}

static int l2cap_sock_setsockopt(struct socket *sock, int level, int optname, char __user *optval, int optlen)
{
	struct sock *sk = sock->sk;
	struct l2cap_options opts;
	int err = 0, len;
	u32 opt;

	BT_DBG("sk %p", sk);

	lock_sock(sk);

	switch (optname) {
	case L2CAP_OPTIONS:
		len = min_t(unsigned int, sizeof(opts), optlen);
		if (copy_from_user((char *)&opts, optval, len)) {
			err = -EFAULT;
			break;
		}
		l2cap_pi(sk)->imtu  = opts.imtu;
		l2cap_pi(sk)->omtu  = opts.omtu;
		break;

	case L2CAP_LM:
		if (get_user(opt, (u32 __user *)optval)) {
			err = -EFAULT;
			break;
		}

		l2cap_pi(sk)->link_mode = opt;
		break;

	default:
		err = -ENOPROTOOPT;
		break;
	}

	release_sock(sk);
	return err;
}

static int l2cap_sock_getsockopt(struct socket *sock, int level, int optname, char __user *optval, int __user *optlen)
{
	struct sock *sk = sock->sk;
	struct l2cap_options opts;
	struct l2cap_conninfo cinfo;
	int len, err = 0; 

	if (get_user(len, optlen))
		return -EFAULT;

	lock_sock(sk);

	switch (optname) {
	case L2CAP_OPTIONS:
		opts.imtu     = l2cap_pi(sk)->imtu;
		opts.omtu     = l2cap_pi(sk)->omtu;
		opts.flush_to = l2cap_pi(sk)->flush_to;

		len = min_t(unsigned int, len, sizeof(opts));
		if (copy_to_user(optval, (char *)&opts, len))
			err = -EFAULT;

		break;

	case L2CAP_LM:
		if (put_user(l2cap_pi(sk)->link_mode, (u32 __user *)optval))
			err = -EFAULT;
		break;

	case L2CAP_CONNINFO:
		if (sk->sk_state != BT_CONNECTED) {
			err = -ENOTCONN;
			break;
		}

		cinfo.hci_handle = l2cap_pi(sk)->conn->hcon->handle;

		len = min_t(unsigned int, len, sizeof(cinfo));
		if (copy_to_user(optval, (char *)&cinfo, len))
			err = -EFAULT;

		break;

	default:
		err = -ENOPROTOOPT;
		break;
	}

	release_sock(sk);
	return err;
}

static int l2cap_sock_shutdown(struct socket *sock, int how)
{
	struct sock *sk = sock->sk;
	int err = 0;

	BT_DBG("sock %p, sk %p", sock, sk);

	if (!sk)
		return 0;

	lock_sock(sk);
	if (!sk->sk_shutdown) {
		sk->sk_shutdown = SHUTDOWN_MASK;
		l2cap_sock_clear_timer(sk);
		__l2cap_sock_close(sk, 0);

		if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime)
			err = bt_sock_wait_state(sk, BT_CLOSED, sk->sk_lingertime);
	}
	release_sock(sk);
	return err;
}

static int l2cap_sock_release(struct socket *sock)
{
	struct sock *sk = sock->sk;
	int err;

	BT_DBG("sock %p, sk %p", sock, sk);

	if (!sk)
		return 0;

	err = l2cap_sock_shutdown(sock, 2);

	sock_orphan(sk);
	l2cap_sock_kill(sk);
	return err;
}

/* ---- L2CAP channels ---- */
static struct sock *__l2cap_get_chan_by_dcid(struct l2cap_chan_list *l, u16 cid)
{
	struct sock *s;
	for (s = l->head; s; s = l2cap_pi(s)->next_c) {
		if (l2cap_pi(s)->dcid == cid)
			break;
	}
	return s;
}

static struct sock *__l2cap_get_chan_by_scid(struct l2cap_chan_list *l, u16 cid)
{
	struct sock *s;
	for (s = l->head; s; s = l2cap_pi(s)->next_c) {
		if (l2cap_pi(s)->scid == cid)
			break;
	}
	return s;
}

/* Find channel with given SCID.
 * Returns locked socket */
static inline struct sock *l2cap_get_chan_by_scid(struct l2cap_chan_list *l, u16 cid)
{
	struct sock *s;
	read_lock(&l->lock);
	s = __l2cap_get_chan_by_scid(l, cid);
	if (s) bh_lock_sock(s);
	read_unlock(&l->lock);
	return s;
}

static u16 l2cap_alloc_cid(struct l2cap_chan_list *l)
{
	u16 cid = 0x0040;

	for (; cid < 0xffff; cid++) {
		if(!__l2cap_get_chan_by_scid(l, cid))
			return cid;
	}

	return 0;
}

static inline void __l2cap_chan_link(struct l2cap_chan_list *l, struct sock *sk)
{
	sock_hold(sk);

	if (l->head)
		l2cap_pi(l->head)->prev_c = sk;

	l2cap_pi(sk)->next_c = l->head;
	l2cap_pi(sk)->prev_c = NULL;
	l->head = sk;
}

static inline void l2cap_chan_unlink(struct l2cap_chan_list *l, struct sock *sk)
{
	struct sock *next = l2cap_pi(sk)->next_c, *prev = l2cap_pi(sk)->prev_c;

	write_lock(&l->lock);
	if (sk == l->head)
		l->head = next;

	if (next)
		l2cap_pi(next)->prev_c = prev;
	if (prev)
		l2cap_pi(prev)->next_c = next;
	write_unlock(&l->lock);

	__sock_put(sk);
}

static void __l2cap_chan_add(struct l2cap_conn *conn, struct sock *sk, struct sock *parent)
{
	struct l2cap_chan_list *l = &conn->chan_list;

	BT_DBG("conn %p, psm 0x%2.2x, dcid 0x%4.4x", conn, l2cap_pi(sk)->psm, l2cap_pi(sk)->dcid);

	l2cap_pi(sk)->conn = conn;

	if (sk->sk_type == SOCK_SEQPACKET) {
		/* Alloc CID for connection-oriented socket */
		l2cap_pi(sk)->scid = l2cap_alloc_cid(l);
	} else if (sk->sk_type == SOCK_DGRAM) {
		/* Connectionless socket */
		l2cap_pi(sk)->scid = 0x0002;
		l2cap_pi(sk)->dcid = 0x0002;
		l2cap_pi(sk)->omtu = L2CAP_DEFAULT_MTU;
	} else {
		/* Raw socket can send/recv signalling messages only */
		l2cap_pi(sk)->scid = 0x0001;
		l2cap_pi(sk)->dcid = 0x0001;
		l2cap_pi(sk)->omtu = L2CAP_DEFAULT_MTU;
	}

	__l2cap_chan_link(l, sk);

	if (parent)
		bt_accept_enqueue(parent, sk);
}

/* Delete channel. 
 * Must be called on the locked socket. */
static void l2cap_chan_del(struct sock *sk, int err)
{
	struct l2cap_conn *conn = l2cap_pi(sk)->conn;
	struct sock *parent = bt_sk(sk)->parent;

	l2cap_sock_clear_timer(sk);

	BT_DBG("sk %p, conn %p, err %d", sk, conn, err);

	if (conn) { 
		/* Unlink from channel list */
		l2cap_chan_unlink(&conn->chan_list, sk);
		l2cap_pi(sk)->conn = NULL;
		hci_conn_put(conn->hcon);
	}

	sk->sk_state  = BT_CLOSED;
	sk->sk_zapped = 1;

	if (err)
		sk->sk_err = err;

	if (parent)
		parent->sk_data_ready(parent, 0);
	else
		sk->sk_state_change(sk);
}

static void l2cap_conn_ready(struct l2cap_conn *conn)
{
	struct l2cap_chan_list *l = &conn->chan_list;
	struct sock *sk;

	BT_DBG("conn %p", conn);

	read_lock(&l->lock);

	for (sk = l->head; sk; sk = l2cap_pi(sk)->next_c) {
		bh_lock_sock(sk);

		if (sk->sk_type != SOCK_SEQPACKET) {
			l2cap_sock_clear_timer(sk);
			sk->sk_state = BT_CONNECTED;
			sk->sk_state_change(sk);
		} else if (sk->sk_state == BT_CONNECT) {
			struct l2cap_conn_req req;
			req.scid = __cpu_to_le16(l2cap_pi(sk)->scid);
			req.psm  = l2cap_pi(sk)->psm;
			l2cap_send_req(conn, L2CAP_CONN_REQ, sizeof(req), &req);
		}

		bh_unlock_sock(sk);
	}

	read_unlock(&l->lock);
}

static void l2cap_chan_ready(struct sock *sk)
{
	struct sock *parent = bt_sk(sk)->parent;

	BT_DBG("sk %p, parent %p", sk, parent);

	l2cap_pi(sk)->conf_state = 0;
	l2cap_sock_clear_timer(sk);

	if (!parent) {
		/* Outgoing channel.
		 * Wake up socket sleeping on connect.
		 */
		sk->sk_state = BT_CONNECTED;
		sk->sk_state_change(sk);
	} else {
		/* Incoming channel.
		 * Wake up socket sleeping on accept.
		 */
		parent->sk_data_ready(parent, 0);
	}
}

/* Copy frame to all raw sockets on that connection */
static void l2cap_raw_recv(struct l2cap_conn *conn, struct sk_buff *skb)
{
	struct l2cap_chan_list *l = &conn->chan_list;
	struct sk_buff *nskb;
	struct sock * sk;

	BT_DBG("conn %p", conn);

	read_lock(&l->lock);
	for (sk = l->head; sk; sk = l2cap_pi(sk)->next_c) {
		if (sk->sk_type != SOCK_RAW)
			continue;

		/* Don't send frame to the socket it came from */
		if (skb->sk == sk)
			continue;

		if (!(nskb = skb_clone(skb, GFP_ATOMIC)))
			continue;

		if (sock_queue_rcv_skb(sk, nskb))
			kfree_skb(nskb);
	}
	read_unlock(&l->lock);
}

/* ---- L2CAP signalling commands ---- */
static inline u8 l2cap_get_ident(struct l2cap_conn *conn)
{
	u8 id;

	/* Get next available identificator.
	 *    1 - 199 are used by kernel.
	 *  200 - 254 are used by utilities like l2ping, etc 
	 */

	spin_lock(&conn->lock);

	if (++conn->tx_ident > 199)
		conn->tx_ident = 1;

	id = conn->tx_ident;

	spin_unlock(&conn->lock);

	return id;
}

static struct sk_buff *l2cap_build_cmd(struct l2cap_conn *conn,
				u8 code, u8 ident, u16 dlen, void *data)
{
	struct sk_buff *skb, **frag;
	struct l2cap_cmd_hdr *cmd;
	struct l2cap_hdr *lh;
	int len, count;

	BT_DBG("conn %p, code 0x%2.2x, ident 0x%2.2x, len %d", conn, code, ident, dlen);

	len = L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE + dlen;
	count = min_t(unsigned int, conn->mtu, len);