dccp: Extend CCID packet dequeueing interface

[karo-tx-linux.git] / net / dccp / output.c

diff --git a/net/dccp/output.c b/net/dccp/output.c
index a988fe9ffcbafdf74b6e90b24f4e8b8caa57591d..11418a9a389d3564654d3b5a971dafe481f14969 100644 (file)
--- a/net/dccp/output.c
+++ b/net/dccp/output.c
@@ -254,63 +254,89 @@ do_interrupted:
        goto out;
 }
 
+/**
+ * dccp_xmit_packet  -  Send data packet under control of CCID
+ * Transmits next-queued payload and informs CCID to account for the packet.
+ */
+static void dccp_xmit_packet(struct sock *sk)
+{
+       int err, len;
+       struct dccp_sock *dp = dccp_sk(sk);
+       struct sk_buff *skb = skb_dequeue(&sk->sk_write_queue);
+
+       if (unlikely(skb == NULL))
+               return;
+       len = skb->len;
+
+       if (sk->sk_state == DCCP_PARTOPEN) {
+               const u32 cur_mps = dp->dccps_mss_cache - DCCP_FEATNEG_OVERHEAD;
+               /*
+                * See 8.1.5 - Handshake Completion.
+                *
+                * For robustness we resend Confirm options until the client has
+                * entered OPEN. During the initial feature negotiation, the MPS
+                * is smaller than usual, reduced by the Change/Confirm options.
+                */
+               if (!list_empty(&dp->dccps_featneg) && len > cur_mps) {
+                       DCCP_WARN("Payload too large (%d) for featneg.\n", len);
+                       dccp_send_ack(sk);
+                       dccp_feat_list_purge(&dp->dccps_featneg);
+               }
+
+               inet_csk_schedule_ack(sk);
+               inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
+                                             inet_csk(sk)->icsk_rto,
+                                             DCCP_RTO_MAX);
+               DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_DATAACK;
+       } else if (dccp_ack_pending(sk)) {
+               DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_DATAACK;
+       } else {
+               DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_DATA;
+       }
+
+       err = dccp_transmit_skb(sk, skb);
+       if (err)
+               dccp_pr_debug("transmit_skb() returned err=%d\n", err);
+       /*
+        * Register this one as sent even if an error occurred. To the remote
+        * end a local packet drop is indistinguishable from network loss, i.e.
+        * any local drop will eventually be reported via receiver feedback.
+        */
+       ccid_hc_tx_packet_sent(dp->dccps_hc_tx_ccid, sk, len);
+}
+
 void dccp_write_xmit(struct sock *sk, int block)
 {
        struct dccp_sock *dp = dccp_sk(sk);
        struct sk_buff *skb;
 
        while ((skb = skb_peek(&sk->sk_write_queue))) {
-               int err = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb);
+               int rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb);
 
-               if (err > 0) {
+               switch (ccid_packet_dequeue_eval(rc)) {
+               case CCID_PACKET_WILL_DEQUEUE_LATER:
+                       return;
+               case CCID_PACKET_DELAY:
                        if (!block) {
                                sk_reset_timer(sk, &dp->dccps_xmit_timer,
-                                               msecs_to_jiffies(err)+jiffies);
+                                               msecs_to_jiffies(rc)+jiffies);
+                               return;
+                       }
+                       rc = dccp_wait_for_ccid(sk, skb, rc);
+                       if (rc && rc != -EINTR) {
+                               DCCP_BUG("err=%d after dccp_wait_for_ccid", rc);
+                               skb_dequeue(&sk->sk_write_queue);
+                               kfree_skb(skb);
                                break;
-                       } else
-                               err = dccp_wait_for_ccid(sk, skb, err);
-                       if (err && err != -EINTR)
-                               DCCP_BUG("err=%d after dccp_wait_for_ccid", err);
-               }
-
-               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) {
-                               const u32 cur_mps = dp->dccps_mss_cache - DCCP_FEATNEG_OVERHEAD;
-                               /*
-                                * See 8.1.5 - Handshake Completion.
-                                *
-                                * For robustness we resend Confirm options until the client has
-                                * entered OPEN. During the initial feature negotiation, the MPS
-                                * is smaller than usual, reduced by the Change/Confirm options.
-                                */
-                               if (!list_empty(&dp->dccps_featneg) && len > cur_mps) {
-                                       DCCP_WARN("Payload too large (%d) for featneg.\n", len);
-                                       dccp_send_ack(sk);
-                                       dccp_feat_list_purge(&dp->dccps_featneg);
-                               }
-
-                               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;
-
-                       err = dccp_transmit_skb(sk, skb);
-                       ccid_hc_tx_packet_sent(dp->dccps_hc_tx_ccid, sk, len);
-                       if (err)
-                               DCCP_BUG("err=%d after ccid_hc_tx_packet_sent",
-                                        err);
-               } else {
-                       dccp_pr_debug("packet discarded due to err=%d\n", err);
+                       }
+                       /* fall through */
+               case CCID_PACKET_SEND_AT_ONCE:
+                       dccp_xmit_packet(sk);
+                       break;
+               case CCID_PACKET_ERR:
+                       skb_dequeue(&sk->sk_write_queue);
                        kfree_skb(skb);
+                       dccp_pr_debug("packet discarded due to err=%d\n", rc);
                }
        }
 }