---

yaml
---
r: 306926
b: refs/heads/master
c: 94122bb
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: daf6a78c161fccd058ca2f1b21e757ebaa2e9909
+refs/heads/master: 94122bbe9c8c4ad7ba9f02f9a30bfc95672c404e

trunk/include/net/bluetooth/l2cap.h

@@ -44,6 +44,7 @@
 #define L2CAP_DEFAULT_MAX_SDU_SIZE	0xFFFF
 #define L2CAP_DEFAULT_SDU_ITIME		0xFFFFFFFF
 #define L2CAP_DEFAULT_ACC_LAT		0xFFFFFFFF
+#define L2CAP_BREDR_MAX_PAYLOAD		1019    /* 3-DH5 packet */
 
 #define L2CAP_DISC_TIMEOUT		msecs_to_jiffies(100)
 #define L2CAP_DISC_REJ_TIMEOUT		msecs_to_jiffies(5000)

trunk/net/bluetooth/l2cap_core.c

@@ -1634,6 +1634,7 @@ static void l2cap_streaming_send(struct l2cap_chan *chan)
 	while ((skb = skb_dequeue(&chan->tx_q))) {
 		control = __get_control(chan, skb->data + L2CAP_HDR_SIZE);
 		control |= __set_txseq(chan, chan->next_tx_seq);
+		control |= __set_ctrl_sar(chan, bt_cb(skb)->control.sar);
 		__put_control(chan, control, skb->data + L2CAP_HDR_SIZE);
 
 		if (chan->fcs == L2CAP_FCS_CRC16) {
@@ -1706,6 +1707,9 @@ static int l2cap_ertm_send(struct l2cap_chan *chan)
 	if (chan->state != BT_CONNECTED)
 		return -ENOTCONN;
 
+	if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state))
+		return 0;
+
 	while ((skb = chan->tx_send_head) && (!l2cap_tx_window_full(chan))) {
 
 		if (bt_cb(skb)->control.retries == chan->remote_max_tx &&
@@ -1726,6 +1730,7 @@ static int l2cap_ertm_send(struct l2cap_chan *chan)
 
 		control |= __set_reqseq(chan, chan->buffer_seq);
 		control |= __set_txseq(chan, chan->next_tx_seq);
+		control |= __set_ctrl_sar(chan, bt_cb(skb)->control.sar);
 
 		__put_control(chan, control, tx_skb->data + L2CAP_HDR_SIZE);
 
@@ -1921,7 +1926,7 @@ static struct sk_buff *l2cap_create_basic_pdu(struct l2cap_chan *chan,
 
 static struct sk_buff *l2cap_create_iframe_pdu(struct l2cap_chan *chan,
 						struct msghdr *msg, size_t len,
-						u32 control, u16 sdulen)
+						u16 sdulen)
 {
 	struct l2cap_conn *conn = chan->conn;
 	struct sk_buff *skb;
@@ -1956,7 +1961,7 @@ static struct sk_buff *l2cap_create_iframe_pdu(struct l2cap_chan *chan,
 	lh->cid = cpu_to_le16(chan->dcid);
 	lh->len = cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE));
 
-	__put_control(chan, control, skb_put(skb, __ctrl_size(chan)));
+	__put_control(chan, 0, skb_put(skb, __ctrl_size(chan)));
 
 	if (sdulen)
 		put_unaligned_le16(sdulen, skb_put(skb, L2CAP_SDULEN_SIZE));
@@ -1974,57 +1979,78 @@ static struct sk_buff *l2cap_create_iframe_pdu(struct l2cap_chan *chan,
 	return skb;
 }
 
-static int l2cap_sar_segment_sdu(struct l2cap_chan *chan, struct msghdr *msg, size_t len)
+static int l2cap_segment_sdu(struct l2cap_chan *chan,
+			     struct sk_buff_head *seg_queue,
+			     struct msghdr *msg, size_t len)
 {
 	struct sk_buff *skb;
-	struct sk_buff_head sar_queue;
-	u32 control;
-	size_t size = 0;
+	u16 sdu_len;
+	size_t pdu_len;
+	int err = 0;
+	u8 sar;
 
-	skb_queue_head_init(&sar_queue);
-	control = __set_ctrl_sar(chan, L2CAP_SAR_START);
-	skb = l2cap_create_iframe_pdu(chan, msg, chan->remote_mps, control, len);
-	if (IS_ERR(skb))
-		return PTR_ERR(skb);
+	BT_DBG("chan %p, msg %p, len %d", chan, msg, (int)len);
 
-	__skb_queue_tail(&sar_queue, skb);
-	len -= chan->remote_mps;
-	size += chan->remote_mps;
+	/* It is critical that ERTM PDUs fit in a single HCI fragment,
+	 * so fragmented skbs are not used.  The HCI layer's handling
+	 * of fragmented skbs is not compatible with ERTM's queueing.
+	 */
 
-	while (len > 0) {
-		size_t buflen;
+	/* PDU size is derived from the HCI MTU */
+	pdu_len = chan->conn->mtu;
 
-		if (len > chan->remote_mps) {
-			control = __set_ctrl_sar(chan, L2CAP_SAR_CONTINUE);
-			buflen = chan->remote_mps;
-		} else {
-			control = __set_ctrl_sar(chan, L2CAP_SAR_END);
-			buflen = len;
-		}
+	pdu_len = min_t(size_t, pdu_len, L2CAP_BREDR_MAX_PAYLOAD);
+
+	/* Adjust for largest possible L2CAP overhead. */
+	pdu_len -= L2CAP_EXT_HDR_SIZE + L2CAP_FCS_SIZE;
+
+	/* Remote device may have requested smaller PDUs */
+	pdu_len = min_t(size_t, pdu_len, chan->remote_mps);
+
+	if (len <= pdu_len) {
+		sar = L2CAP_SAR_UNSEGMENTED;
+		sdu_len = 0;
+		pdu_len = len;
+	} else {
+		sar = L2CAP_SAR_START;
+		sdu_len = len;
+		pdu_len -= L2CAP_SDULEN_SIZE;
+	}
+
+	while (len > 0) {
+		skb = l2cap_create_iframe_pdu(chan, msg, pdu_len, sdu_len);
 
-		skb = l2cap_create_iframe_pdu(chan, msg, buflen, control, 0);
 		if (IS_ERR(skb)) {
-			skb_queue_purge(&sar_queue);
+			__skb_queue_purge(seg_queue);
 			return PTR_ERR(skb);
 		}
 
-		__skb_queue_tail(&sar_queue, skb);
-		len -= buflen;
-		size += buflen;
+		bt_cb(skb)->control.sar = sar;
+		__skb_queue_tail(seg_queue, skb);
+
+		len -= pdu_len;
+		if (sdu_len) {
+			sdu_len = 0;
+			pdu_len += L2CAP_SDULEN_SIZE;
+		}
+
+		if (len <= pdu_len) {
+			sar = L2CAP_SAR_END;
+			pdu_len = len;
+		} else {
+			sar = L2CAP_SAR_CONTINUE;
+		}
 	}
-	skb_queue_splice_tail(&sar_queue, &chan->tx_q);
-	if (chan->tx_send_head == NULL)
-		chan->tx_send_head = sar_queue.next;
 
-	return size;
+	return err;
 }
 
 int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len,
 								u32 priority)
 {
 	struct sk_buff *skb;
-	u32 control;
 	int err;
+	struct sk_buff_head seg_queue;
 
 	/* Connectionless channel */
 	if (chan->chan_type == L2CAP_CHAN_CONN_LESS) {
@@ -2053,42 +2079,44 @@ int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len,
 
 	case L2CAP_MODE_ERTM:
 	case L2CAP_MODE_STREAMING:
-		/* Entire SDU fits into one PDU */
-		if (len <= chan->remote_mps) {
-			control = __set_ctrl_sar(chan, L2CAP_SAR_UNSEGMENTED);
-			skb = l2cap_create_iframe_pdu(chan, msg, len, control,
-									0);
-			if (IS_ERR(skb))
-				return PTR_ERR(skb);
+		/* Check outgoing MTU */
+		if (len > chan->omtu) {
+			err = -EMSGSIZE;
+			break;
+		}
 
-			__skb_queue_tail(&chan->tx_q, skb);
+		__skb_queue_head_init(&seg_queue);
 
-			if (chan->tx_send_head == NULL)
-				chan->tx_send_head = skb;
+		/* Do segmentation before calling in to the state machine,
+		 * since it's possible to block while waiting for memory
+		 * allocation.
+		 */
+		err = l2cap_segment_sdu(chan, &seg_queue, msg, len);
 
-		} else {
-			/* Segment SDU into multiples PDUs */
-			err = l2cap_sar_segment_sdu(chan, msg, len);
-			if (err < 0)
-				return err;
+		/* The channel could have been closed while segmenting,
+		 * check that it is still connected.
+		 */
+		if (chan->state != BT_CONNECTED) {
+			__skb_queue_purge(&seg_queue);
+			err = -ENOTCONN;
 		}
 
-		if (chan->mode == L2CAP_MODE_STREAMING) {
-			l2cap_streaming_send(chan);
-			err = len;
+		if (err)
 			break;
-		}
 
-		if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state) &&
-				test_bit(CONN_WAIT_F, &chan->conn_state)) {
-			err = len;
-			break;
-		}
+		skb_queue_splice_tail_init(&seg_queue, &chan->tx_q);
+		if (chan->mode == L2CAP_MODE_ERTM)
+			err = l2cap_ertm_send(chan);
+		else
+			l2cap_streaming_send(chan);
 
-		err = l2cap_ertm_send(chan);
 		if (err >= 0)
 			err = len;
 
+		/* If the skbs were not queued for sending, they'll still be in
+		 * seg_queue and need to be purged.
+		 */
+		__skb_queue_purge(&seg_queue);
 		break;
 
 	default: