redonkable/alistair23-linux
redonkable/alistair23-linux
1
0
Fork 0
Code Releases Activity

Bluetooth: Add LE L2CAP segmentation support for outgoing data

Browse source 
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@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This commit is contained in:
Johan Hedberg 2013-05-31 17:54:51 +03:00 committed by Marcel Holtmann
parent 837776f790
commit 177f8f2b12
1 changed files with 126 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

127
net/bluetooth/l2cap_core.c
View file

@ -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)