3 files changed, 89 insertions, 19 deletions

diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
index 9c18e555b6ed..66b8d9688d9e 100644
--- a/include/net/bluetooth/l2cap.h
+++ b/include/net/bluetooth/l2cap.h
@@ -422,6 +422,7 @@ struct l2cap_conn {
 struct l2cap_pinfo {
 	struct bt_sock	bt;
 	struct l2cap_chan	*chan;
+	struct sk_buff	*rx_busy_skb;
 };
 
 enum {
@@ -498,5 +499,6 @@ void l2cap_chan_close(struct l2cap_chan *chan, int reason);
 void l2cap_chan_destroy(struct l2cap_chan *chan);
 int l2cap_chan_connect(struct l2cap_chan *chan);
 int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len);
+void l2cap_chan_busy(struct l2cap_chan *chan, int busy);
 
 #endif /* __L2CAP_H */
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index f7ada4a2cc5d..ea9c7d061046 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -3350,21 +3350,21 @@ static int l2cap_push_rx_skb(struct l2cap_chan *chan, struct sk_buff *skb, u16 c
 	}
 
 	err = l2cap_ertm_reassembly_sdu(chan, skb, control);
-	if (err >= 0) {
-		chan->buffer_seq = (chan->buffer_seq + 1) % 64;
-		return err;
-	}
-
-	l2cap_ertm_enter_local_busy(chan);
-
-	bt_cb(skb)->sar = control >> L2CAP_CTRL_SAR_SHIFT;
-	__skb_queue_tail(&chan->busy_q, skb);
-
-	queue_work(_busy_wq, &chan->busy_work);
+	chan->buffer_seq = (chan->buffer_seq + 1) % 64;
 
 	return err;
 }
 
+void l2cap_chan_busy(struct l2cap_chan *chan, int busy)
+{
+	if (chan->mode == L2CAP_MODE_ERTM) {
+		if (busy)
+			l2cap_ertm_enter_local_busy(chan);
+		else
+			l2cap_ertm_exit_local_busy(chan);
+	}
+}
+
 static int l2cap_streaming_reassembly_sdu(struct l2cap_chan *chan, struct sk_buff *skb, u16 control)
 {
 	struct sk_buff *_skb;
@@ -3463,13 +3463,22 @@ static void l2cap_check_srej_gap(struct l2cap_chan *chan, u8 tx_seq)
 	struct sk_buff *skb;
 	u16 control;
 
-	while ((skb = skb_peek(&chan->srej_q))) {
+	while ((skb = skb_peek(&chan->srej_q)) &&
+			!test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
+		int err;
+
 		if (bt_cb(skb)->tx_seq != tx_seq)
 			break;
 
 		skb = skb_dequeue(&chan->srej_q);
 		control = bt_cb(skb)->sar << L2CAP_CTRL_SAR_SHIFT;
-		l2cap_ertm_reassembly_sdu(chan, skb, control);
+		err = l2cap_ertm_reassembly_sdu(chan, skb, control);
+
+		if (err < 0) {
+			l2cap_send_disconn_req(chan->conn, chan, ECONNRESET);
+			break;
+		}
+
 		chan->buffer_seq_srej =
 			(chan->buffer_seq_srej + 1) % 64;
 		tx_seq = (tx_seq + 1) % 64;
@@ -3625,8 +3634,10 @@ expected:
 	}
 
 	err = l2cap_push_rx_skb(chan, skb, rx_control);
-	if (err < 0)
-		return 0;
+	if (err < 0) {
+		l2cap_send_disconn_req(chan->conn, chan, ECONNRESET);
+		return err;
+	}
 
 	if (rx_control & L2CAP_CTRL_FINAL) {
 		if (!test_and_clear_bit(CONN_REJ_ACT, &chan->conn_state))
diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index 39082d4e77ce..146b614d10ed 100644
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -711,13 +711,15 @@ static int l2cap_sock_sendmsg(struct kiocb *iocb, struct socket *sock, struct ms
 static int l2cap_sock_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg, size_t len, int flags)
 {
 	struct sock *sk = sock->sk;
+	struct l2cap_pinfo *pi = l2cap_pi(sk);
+	int err;
 
 	lock_sock(sk);
 
 	if (sk->sk_state == BT_CONNECT2 && bt_sk(sk)->defer_setup) {
 		sk->sk_state = BT_CONFIG;
 
-		__l2cap_connect_rsp_defer(l2cap_pi(sk)->chan);
+		__l2cap_connect_rsp_defer(pi->chan);
 		release_sock(sk);
 		return 0;
 	}
@@ -725,9 +727,37 @@ static int l2cap_sock_recvmsg(struct kiocb *iocb, struct socket *sock, struct ms
 	release_sock(sk);
 
 	if (sock->type == SOCK_STREAM)
-		return bt_sock_stream_recvmsg(iocb, sock, msg, len, flags);
+		err = bt_sock_stream_recvmsg(iocb, sock, msg, len, flags);
+	else
+		err = bt_sock_recvmsg(iocb, sock, msg, len, flags);
+
+	if (pi->chan->mode != L2CAP_MODE_ERTM)
+		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;
+
+	if (pi->rx_busy_skb) {
+		if (!sock_queue_rcv_skb(sk, pi->rx_busy_skb))
+			pi->rx_busy_skb = NULL;
+		else
+			goto done;
+	}
 
-	return bt_sock_recvmsg(iocb, sock, msg, len, flags);
+	/* 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)
+		l2cap_chan_busy(pi->chan, 0);
+
+done:
+	release_sock(sk);
+	return err;
 }
 
 /* Kill socket (only if zapped and orphan)
@@ -811,9 +841,31 @@ static struct l2cap_chan *l2cap_sock_new_connection_cb(void *data)
 
 static int l2cap_sock_recv_cb(void *data, struct sk_buff *skb)
 {
+	int err;
 	struct sock *sk = data;
+	struct l2cap_pinfo *pi = l2cap_pi(sk);
 
-	return sock_queue_rcv_skb(sk, skb);
+	if (pi->rx_busy_skb)
+		return -ENOMEM;
+
+	err = sock_queue_rcv_skb(sk, skb);
+
+	/* For ERTM, handle one 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.
+	 *
+	 * Notify the l2cap core that the buffer is full, so the
+	 * LOCAL_BUSY state is entered and no more frames are
+	 * acked and reassembled until there is buffer space
+	 * available.
+	 */
+	if (err < 0 && pi->chan->mode == L2CAP_MODE_ERTM) {
+		pi->rx_busy_skb = skb;
+		l2cap_chan_busy(pi->chan, 1);
+		err = 0;
+	}
+
+	return err;
 }
 
 static void l2cap_sock_close_cb(void *data)
@@ -842,6 +894,11 @@ static void l2cap_sock_destruct(struct sock *sk)
 {
 	BT_DBG("sk %p", sk);
 
+	if (l2cap_pi(sk)->rx_busy_skb) {
+		kfree_skb(l2cap_pi(sk)->rx_busy_skb);
+		l2cap_pi(sk)->rx_busy_skb = NULL;
+	}
+
 	skb_queue_purge(&sk->sk_receive_queue);
 	skb_queue_purge(&sk->sk_write_queue);
 }