1 files changed, 73 insertions, 18 deletions

diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index 5cc83f906c..8645461d45 100644
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -1131,6 +1131,34 @@ static int l2cap_sock_sendmsg(struct socket *sock, struct msghdr *msg,
 	return err;
 }
 
+static void l2cap_publish_rx_avail(struct l2cap_chan *chan)
+{
+	struct sock *sk = chan->data;
+	ssize_t avail = sk->sk_rcvbuf - atomic_read(&sk->sk_rmem_alloc);
+	int expected_skbs, skb_overhead;
+
+	if (avail <= 0) {
+		l2cap_chan_rx_avail(chan, 0);
+		return;
+	}
+
+	if (!chan->mps) {
+		l2cap_chan_rx_avail(chan, -1);
+		return;
+	}
+
+	/* Correct available memory by estimated sk_buff overhead.
+	 * This is significant due to small transfer sizes. However, accept
+	 * at least one full packet if receive space is non-zero.
+	 */
+	expected_skbs = DIV_ROUND_UP(avail, chan->mps);
+	skb_overhead = expected_skbs * sizeof(struct sk_buff);
+	if (skb_overhead < avail)
+		l2cap_chan_rx_avail(chan, avail - skb_overhead);
+	else
+		l2cap_chan_rx_avail(chan, -1);
+}
+
 static int l2cap_sock_recvmsg(struct socket *sock, struct msghdr *msg,
 			      size_t len, int flags)
 {
@@ -1167,28 +1195,33 @@ static int l2cap_sock_recvmsg(struct socket *sock, struct msghdr *msg,
 	else
 		err = bt_sock_recvmsg(sock, msg, len, flags);
 
-	if (pi->chan->mode != L2CAP_MODE_ERTM)
+	if (pi->chan->mode != L2CAP_MODE_ERTM &&
+	    pi->chan->mode != L2CAP_MODE_LE_FLOWCTL &&
+	    pi->chan->mode != L2CAP_MODE_EXT_FLOWCTL)
 		return err;
 
-	/* Attempt to put pending rx data in the socket buffer */
-
 	lock_sock(sk);
 
-	if (!test_bit(CONN_LOCAL_BUSY, &pi->chan->conn_state))
-		goto done;
+	l2cap_publish_rx_avail(pi->chan);
 
-	if (pi->rx_busy_skb) {
-		if (!__sock_queue_rcv_skb(sk, pi->rx_busy_skb))
-			pi->rx_busy_skb = NULL;
-		else
+	/* Attempt to put pending rx data in the socket buffer */
+	while (!list_empty(&pi->rx_busy)) {
+		struct l2cap_rx_busy *rx_busy =
+			list_first_entry(&pi->rx_busy,
+					 struct l2cap_rx_busy,
+					 list);
+		if (__sock_queue_rcv_skb(sk, rx_busy->skb) < 0)
 			goto done;
+		list_del(&rx_busy->list);
+		kfree(rx_busy);
 	}
 
 	/* Restore data flow when half of the receive buffer is
 	 * available.  This avoids resending large numbers of
 	 * frames.
 	 */
-	if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf >> 1)
+	if (test_bit(CONN_LOCAL_BUSY, &pi->chan->conn_state) &&
+	    atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf >> 1)
 		l2cap_chan_busy(pi->chan, 0);
 
 done:
@@ -1449,17 +1482,20 @@ static struct l2cap_chan *l2cap_sock_new_connection_cb(struct l2cap_chan *chan)
 static int l2cap_sock_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
 {
 	struct sock *sk = chan->data;
+	struct l2cap_pinfo *pi = l2cap_pi(sk);
 	int err;
 
 	lock_sock(sk);
 
-	if (l2cap_pi(sk)->rx_busy_skb) {
+	if (chan->mode == L2CAP_MODE_ERTM && !list_empty(&pi->rx_busy)) {
 		err = -ENOMEM;
 		goto done;
 	}
 
 	if (chan->mode != L2CAP_MODE_ERTM &&
-	    chan->mode != L2CAP_MODE_STREAMING) {
+	    chan->mode != L2CAP_MODE_STREAMING &&
+	    chan->mode != L2CAP_MODE_LE_FLOWCTL &&
+	    chan->mode != L2CAP_MODE_EXT_FLOWCTL) {
 		/* Even if no filter is attached, we could potentially
 		 * get errors from security modules, etc.
 		 */
@@ -1470,7 +1506,9 @@ static int l2cap_sock_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
 
 	err = __sock_queue_rcv_skb(sk, skb);
 
-	/* For ERTM, handle one skb that doesn't fit into the recv
+	l2cap_publish_rx_avail(chan);
+
+	/* For ERTM and LE, handle a skb that doesn't fit into the recv
 	 * buffer.  This is important to do because the data frames
 	 * have already been acked, so the skb cannot be discarded.
 	 *
@@ -1479,8 +1517,18 @@ static int l2cap_sock_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
 	 * acked and reassembled until there is buffer space
 	 * available.
 	 */
-	if (err < 0 && chan->mode == L2CAP_MODE_ERTM) {
-		l2cap_pi(sk)->rx_busy_skb = skb;
+	if (err < 0 &&
+	    (chan->mode == L2CAP_MODE_ERTM ||
+	     chan->mode == L2CAP_MODE_LE_FLOWCTL ||
+	     chan->mode == L2CAP_MODE_EXT_FLOWCTL)) {
+		struct l2cap_rx_busy *rx_busy =
+			kmalloc(sizeof(*rx_busy), GFP_KERNEL);
+		if (!rx_busy) {
+			err = -ENOMEM;
+			goto done;
+		}
+		rx_busy->skb = skb;
+		list_add_tail(&rx_busy->list, &pi->rx_busy);
 		l2cap_chan_busy(chan, 1);
 		err = 0;
 	}
@@ -1706,6 +1754,8 @@ static const struct l2cap_ops l2cap_chan_ops = {
 
 static void l2cap_sock_destruct(struct sock *sk)
 {
+	struct l2cap_rx_busy *rx_busy, *next;
+
 	BT_DBG("sk %p", sk);
 
 	if (l2cap_pi(sk)->chan) {
@@ -1713,9 +1763,10 @@ static void l2cap_sock_destruct(struct sock *sk)
 		l2cap_chan_put(l2cap_pi(sk)->chan);
 	}
 
-	if (l2cap_pi(sk)->rx_busy_skb) {
-		kfree_skb(l2cap_pi(sk)->rx_busy_skb);
-		l2cap_pi(sk)->rx_busy_skb = NULL;
+	list_for_each_entry_safe(rx_busy, next, &l2cap_pi(sk)->rx_busy, list) {
+		kfree_skb(rx_busy->skb);
+		list_del(&rx_busy->list);
+		kfree(rx_busy);
 	}
 
 	skb_queue_purge(&sk->sk_receive_queue);
@@ -1799,6 +1850,8 @@ static void l2cap_sock_init(struct sock *sk, struct sock *parent)
 
 	chan->data = sk;
 	chan->ops = &l2cap_chan_ops;
+
+	l2cap_publish_rx_avail(chan);
 }
 
 static struct proto l2cap_proto = {
@@ -1820,6 +1873,8 @@ static struct sock *l2cap_sock_alloc(struct net *net, struct socket *sock,
 	sk->sk_destruct = l2cap_sock_destruct;
 	sk->sk_sndtimeo = L2CAP_CONN_TIMEOUT;
 
+	INIT_LIST_HEAD(&l2cap_pi(sk)->rx_busy);
+
 	chan = l2cap_chan_create();
 	if (!chan) {
 		sk_free(sk);