[DCCP]: Introduce tx buffering
This adds transmit buffering to DCCP.
I have tested with CCID2/3 and with loss and rate limiting.
Signed off by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dccp/output.c b/net/dccp/output.c
index 58669be..7102e3a 100644
--- a/net/dccp/output.c
+++ b/net/dccp/output.c
@@ -198,7 +198,7 @@
while (1) {
prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
- if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
+ if (sk->sk_err)
goto do_error;
if (!*timeo)
goto do_nonblock;
@@ -234,37 +234,72 @@
goto out;
}
-int dccp_write_xmit(struct sock *sk, struct sk_buff *skb, long *timeo)
+static void dccp_write_xmit_timer(unsigned long data) {
+ struct sock *sk = (struct sock *)data;
+ struct dccp_sock *dp = dccp_sk(sk);
+
+ bh_lock_sock(sk);
+ if (sock_owned_by_user(sk))
+ sk_reset_timer(sk, &dp->dccps_xmit_timer, jiffies+1);
+ else
+ dccp_write_xmit(sk, 0);
+ bh_unlock_sock(sk);
+ sock_put(sk);
+}
+
+void dccp_write_xmit(struct sock *sk, int block)
{
- const struct dccp_sock *dp = dccp_sk(sk);
- int err = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb,
+ struct dccp_sock *dp = dccp_sk(sk);
+ struct sk_buff *skb;
+ long timeo = 30000; /* If a packet is taking longer than 2 secs
+ we have other issues */
+
+ while ((skb = skb_peek(&sk->sk_write_queue))) {
+ int err = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb,
skb->len);
- if (err > 0)
- err = dccp_wait_for_ccid(sk, skb, timeo);
+ if (err > 0) {
+ if (!block) {
+ sk_reset_timer(sk, &dp->dccps_xmit_timer,
+ msecs_to_jiffies(err)+jiffies);
+ break;
+ } else
+ err = dccp_wait_for_ccid(sk, skb, &timeo);
+ if (err) {
+ printk(KERN_CRIT "%s:err at dccp_wait_for_ccid"
+ " %d\n", __FUNCTION__, err);
+ dump_stack();
+ }
+ }
- if (err == 0) {
- struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
- const int len = skb->len;
+ skb_dequeue(&sk->sk_write_queue);
+ if (err == 0) {
+ struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
+ const int len = skb->len;
- if (sk->sk_state == DCCP_PARTOPEN) {
- /* See 8.1.5. Handshake Completion */
- inet_csk_schedule_ack(sk);
- inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
+ if (sk->sk_state == DCCP_PARTOPEN) {
+ /* See 8.1.5. Handshake Completion */
+ inet_csk_schedule_ack(sk);
+ inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
inet_csk(sk)->icsk_rto,
DCCP_RTO_MAX);
- dcb->dccpd_type = DCCP_PKT_DATAACK;
- } else if (dccp_ack_pending(sk))
- dcb->dccpd_type = DCCP_PKT_DATAACK;
- else
- dcb->dccpd_type = DCCP_PKT_DATA;
+ dcb->dccpd_type = DCCP_PKT_DATAACK;
+ } else if (dccp_ack_pending(sk))
+ dcb->dccpd_type = DCCP_PKT_DATAACK;
+ else
+ dcb->dccpd_type = DCCP_PKT_DATA;
- err = dccp_transmit_skb(sk, skb);
- ccid_hc_tx_packet_sent(dp->dccps_hc_tx_ccid, sk, 0, len);
- } else
- kfree_skb(skb);
-
- return err;
+ err = dccp_transmit_skb(sk, skb);
+ ccid_hc_tx_packet_sent(dp->dccps_hc_tx_ccid, sk, 0, len);
+ if (err) {
+ printk(KERN_CRIT "%s:err from "
+ "ccid_hc_tx_packet_sent %d\n",
+ __FUNCTION__, err);
+ dump_stack();
+ }
+ } else
+ kfree(skb);
+ }
}
int dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
@@ -426,6 +461,9 @@
dccp_set_seqno(&dp->dccps_awl, max48(dp->dccps_awl, dp->dccps_iss));
icsk->icsk_retransmits = 0;
+ init_timer(&dp->dccps_xmit_timer);
+ dp->dccps_xmit_timer.data = (unsigned long)sk;
+ dp->dccps_xmit_timer.function = dccp_write_xmit_timer;
}
int dccp_connect(struct sock *sk)
@@ -560,8 +598,10 @@
DCCP_PKT_CLOSE : DCCP_PKT_CLOSEREQ;
if (active) {
+ dccp_write_xmit(sk, 1);
dccp_skb_entail(sk, skb);
dccp_transmit_skb(sk, skb_clone(skb, prio));
+ /* FIXME do we need a retransmit timer here? */
} else
dccp_transmit_skb(sk, skb);
}