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Bluetooth: Add LE flow control discipline 

This patch adds the necessary discipline for reacting to LE L2CAP
Credits packets, sending those packets, and modifying the known credits
accordingly.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This commit is contained in:
Johan Hedberg 2013-12-05 09:45:01 +02:00 committed by Marcel Holtmann
parent b1c325c23d
commit fad5fc8959
1 changed files with 66 additions and 1 deletions
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67
net/bluetooth/l2cap_core.c
View File

@ -2542,8 +2542,12 @@ int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len,
}
switch (chan->mode) {
case L2CAP_MODE_BASIC:
case L2CAP_MODE_LE_FLOWCTL:
if (!chan->tx_credits)
return -EAGAIN;
/* fall through */
case L2CAP_MODE_BASIC:
/* Check outgoing MTU */
if (len > chan->omtu)
return -EMSGSIZE;
@ -5551,6 +5555,42 @@ response:
return 0;
}
static inline int l2cap_le_credits(struct l2cap_conn *conn,
struct l2cap_cmd_hdr *cmd, u16 cmd_len,
u8 *data)
{
struct l2cap_le_credits *pkt;
struct l2cap_chan *chan;
u16 cid, credits;
if (cmd_len != sizeof(*pkt))
return -EPROTO;
pkt = (struct l2cap_le_credits *) data;
cid = __le16_to_cpu(pkt->cid);
credits = __le16_to_cpu(pkt->credits);
BT_DBG("cid 0x%4.4x credits 0x%4.4x", cid, credits);
chan = l2cap_get_chan_by_dcid(conn, cid);
if (!chan)
return -EBADSLT;
chan->tx_credits += credits;
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->resume(chan);
l2cap_chan_unlock(chan);
return 0;
}
static inline int l2cap_le_sig_cmd(struct l2cap_conn *conn,
struct l2cap_cmd_hdr *cmd, u16 cmd_len,
u8 *data)
@ -5576,6 +5616,10 @@ static inline int l2cap_le_sig_cmd(struct l2cap_conn *conn,
err = l2cap_le_connect_req(conn, cmd, cmd_len, data);
break;
case L2CAP_LE_CREDITS:
err = l2cap_le_credits(conn, cmd, cmd_len, data);
break;
case L2CAP_DISCONN_REQ:
err = l2cap_disconnect_req(conn, cmd, cmd_len, data);
break;
@ -6636,6 +6680,22 @@ static void l2cap_chan_le_send_credits(struct l2cap_chan *chan)
l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CREDITS, sizeof(pkt), &pkt);
}
static int l2cap_le_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb)
{
if (!chan->rx_credits)
return -ENOBUFS;
if (chan->imtu < skb->len)
return -ENOBUFS;
chan->rx_credits--;
BT_DBG("rx_credits %u -> %u", chan->rx_credits + 1, chan->rx_credits);
l2cap_chan_le_send_credits(chan);
return chan->ops->recv(chan, skb);
}
static void l2cap_data_channel(struct l2cap_conn *conn, u16 cid,
struct sk_buff *skb)
{
@ -6666,6 +6726,11 @@ static void l2cap_data_channel(struct l2cap_conn *conn, u16 cid,
switch (chan->mode) {
case L2CAP_MODE_LE_FLOWCTL:
if (l2cap_le_data_rcv(chan, skb) < 0)
goto drop;
goto done;
case L2CAP_MODE_BASIC:
/* If socket recv buffers overflows we drop data here
* which is *bad* because L2CAP has to be reliable.