dccp ccid-2: Stop polling

This updates CCID2 to use the CCID dequeuing mechanism, converting from
previous constant-polling to a now event-driven mechanism.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>

2 files changed, 18 insertions, 8 deletions

diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c
index bbf16b35734d..c7d83e3c1648 100644
--- a/net/dccp/ccids/ccid2.c
+++ b/net/dccp/ccids/ccid2.c
@@ -123,12 +123,9 @@ static int ccid2_hc_tx_alloc_seq(struct ccid2_hc_tx_sock *hctx)
 
 static int ccid2_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
 {
-        struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk);
-
-        if (hctx->pipe < hctx->cwnd)
-                return 0;
-
-        return 1; /* XXX CCID should dequeue when ready instead of polling */
+        if (ccid2_cwnd_network_limited(ccid2_hc_tx_sk(sk)))
+                return CCID_PACKET_WILL_DEQUEUE_LATER;
+        return CCID_PACKET_SEND_AT_ONCE;
 }
 
 static void ccid2_change_l_ack_ratio(struct sock *sk, u32 val)
@@ -168,6 +165,7 @@ static void ccid2_hc_tx_rto_expire(unsigned long data)
 {
         struct sock *sk = (struct sock *)data;
         struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk);
+        const bool sender_was_blocked = ccid2_cwnd_network_limited(hctx);
         long s;
 
         bh_lock_sock(sk);
@@ -187,8 +185,6 @@ static void ccid2_hc_tx_rto_expire(unsigned long data)
         if (s > 60)
                 hctx->rto = 60 * HZ;
 
-        ccid2_start_rto_timer(sk);
-
         /* adjust pipe, cwnd etc */
         hctx->ssthresh = hctx->cwnd / 2;
         if (hctx->ssthresh < 2)
@@ -205,6 +201,11 @@ static void ccid2_hc_tx_rto_expire(unsigned long data)
         hctx->rpdupack = -1;
         ccid2_change_l_ack_ratio(sk, 1);
         ccid2_hc_tx_check_sanity(hctx);
+
+        /* if we were blocked before, we may now send cwnd=1 packet */
+        if (sender_was_blocked)
+                tasklet_schedule(&dccp_sk(sk)->dccps_xmitlet);
+        ccid2_start_rto_timer(sk);
 out:
         bh_unlock_sock(sk);
         sock_put(sk);
@@ -455,6 +456,7 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
 {
         struct dccp_sock *dp = dccp_sk(sk);
         struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk);
+        const bool sender_was_blocked = ccid2_cwnd_network_limited(hctx);
         struct dccp_ackvec_parsed *avp;
         u64 ackno, seqno;
         struct ccid2_seq *seqp;
@@ -640,6 +642,9 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
 
         ccid2_hc_tx_check_sanity(hctx);
 done:
+        /* check if incoming Acks allow pending packets to be sent */
+        if (sender_was_blocked && !ccid2_cwnd_network_limited(hctx))
+                tasklet_schedule(&dccp_sk(sk)->dccps_xmitlet);
         dccp_ackvec_parsed_cleanup(&hctx->av_chunks);
 }
 
diff --git a/net/dccp/ccids/ccid2.h b/net/dccp/ccids/ccid2.h
index 907deed255b4..d5900dd5d4f4 100644
--- a/net/dccp/ccids/ccid2.h
+++ b/net/dccp/ccids/ccid2.h
@@ -70,6 +70,11 @@ struct ccid2_hc_tx_sock {
         struct list_head        av_chunks;
 };
 
+static inline bool ccid2_cwnd_network_limited(struct ccid2_hc_tx_sock *hctx)
+{
+        return (hctx->pipe >= hctx->cwnd);
+}
+
 struct ccid2_hc_rx_sock {
         int                     data;
 };