From: Johan Hedberg <johan.hedberg@xxxxxxxxx>
This patch adds segmentation support for outgoing data packets. Packets
are segmented based on the MTU and MPS values. The l2cap_chan struct
already contains many helpful variables from BR/EDR Enhanced L2CAP which
can be used for this.
Signed-off-by: Johan Hedberg <johan.hedberg@xxxxxxxxx>
---
net/bluetooth/l2cap_core.c | 127 ++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 126 insertions(+), 1 deletion(-)
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index b0287f57d534..2c591afccb51 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -607,6 +607,7 @@ void l2cap_chan_del(struct l2cap_chan *chan, int err)
break;
case L2CAP_MODE_LE_FLOWCTL:
+ skb_queue_purge(&chan->tx_q);
break;
case L2CAP_MODE_ERTM:
@@ -1194,12 +1195,24 @@ static void l2cap_move_done(struct l2cap_chan *chan)
}
}
+static void l2cap_le_flowctl_start(struct l2cap_chan *chan)
+{
+ chan->sdu = NULL;
+ chan->sdu_last_frag = NULL;
+ chan->sdu_len = 0;
+
+ skb_queue_head_init(&chan->tx_q);
+}
+
static void l2cap_chan_ready(struct l2cap_chan *chan)
{
/* This clears all conf flags, including CONF_NOT_COMPLETE */
chan->conf_state = 0;
__clear_chan_timer(chan);
+ if (chan->mode == L2CAP_MODE_LE_FLOWCTL)
+ l2cap_le_flowctl_start(chan);
+
chan->state = BT_CONNECTED;
chan->ops->ready(chan);
@@ -2521,6 +2534,89 @@ static int l2cap_segment_sdu(struct l2cap_chan *chan,
return 0;
}
+static struct sk_buff *l2cap_create_le_flowctl_pdu(struct l2cap_chan *chan,
+ struct msghdr *msg,
+ size_t len, u16 sdulen)
+{
+ struct l2cap_conn *conn = chan->conn;
+ struct sk_buff *skb;
+ int err, count, hlen;
+ struct l2cap_hdr *lh;
+
+ BT_DBG("chan %p len %zu", chan, len);
+
+ if (!conn)
+ return ERR_PTR(-ENOTCONN);
+
+ hlen = L2CAP_HDR_SIZE;
+
+ if (sdulen)
+ hlen += L2CAP_SDULEN_SIZE;
+
+ count = min_t(unsigned int, (conn->mtu - hlen), len);
+
+ skb = chan->ops->alloc_skb(chan, count + hlen,
+ msg->msg_flags & MSG_DONTWAIT);
+ if (IS_ERR(skb))
+ return skb;
+
+ /* Create L2CAP header */
+ lh = (struct l2cap_hdr *) skb_put(skb, L2CAP_HDR_SIZE);
+ lh->cid = cpu_to_le16(chan->dcid);
+ lh->len = cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE));
+
+ if (sdulen)
+ put_unaligned_le16(sdulen, skb_put(skb, L2CAP_SDULEN_SIZE));
+
+ err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
+ if (unlikely(err < 0)) {
+ kfree_skb(skb);
+ return ERR_PTR(err);
+ }
+
+ return skb;
+}
+
+static int l2cap_segment_le_sdu(struct l2cap_chan *chan,
+ struct sk_buff_head *seg_queue,
+ struct msghdr *msg, size_t len)
+{
+ struct sk_buff *skb;
+ size_t pdu_len;
+ u16 sdu_len;
+
+ BT_DBG("chan %p, msg %p, len %zu", chan, msg, len);
+
+ pdu_len = chan->conn->mtu - L2CAP_HDR_SIZE;
+
+ pdu_len = min_t(size_t, pdu_len, chan->remote_mps);
+
+ sdu_len = len;
+ pdu_len -= L2CAP_SDULEN_SIZE;
+
+ while (len > 0) {
+ if (len <= pdu_len)
+ pdu_len = len;
+
+ skb = l2cap_create_le_flowctl_pdu(chan, msg, pdu_len, sdu_len);
+ if (IS_ERR(skb)) {
+ __skb_queue_purge(seg_queue);
+ return PTR_ERR(skb);
+ }
+
+ __skb_queue_tail(seg_queue, skb);
+
+ len -= pdu_len;
+
+ if (sdu_len) {
+ sdu_len = 0;
+ pdu_len += L2CAP_SDULEN_SIZE;
+ }
+ }
+
+ return 0;
+}
+
int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len,
u32 priority)
{
@@ -2543,10 +2639,39 @@ int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len,
switch (chan->mode) {
case L2CAP_MODE_LE_FLOWCTL:
+ /* Check outgoing MTU */
+ if (len > chan->omtu)
+ return -EMSGSIZE;
+
if (!chan->tx_credits)
return -EAGAIN;
- /* fall through */
+ __skb_queue_head_init(&seg_queue);
+
+ err = l2cap_segment_le_sdu(chan, &seg_queue, msg, len);
+
+ if (chan->state != BT_CONNECTED) {
+ __skb_queue_purge(&seg_queue);
+ err = -ENOTCONN;
+ }
+
+ if (err)
+ return err;
+
+ skb_queue_splice_tail_init(&seg_queue, &chan->tx_q);
+
+ while (chan->tx_credits && !skb_queue_empty(&chan->tx_q)) {
+ l2cap_do_send(chan, skb_dequeue(&chan->tx_q));
+ chan->tx_credits--;
+ }
+
+ if (!chan->tx_credits)
+ chan->ops->suspend(chan);
+
+ err = len;
+
+ break;
+
case L2CAP_MODE_BASIC:
/* Check outgoing MTU */
if (len > chan->omtu)
--
1.8.4.2
--
To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
