[TCP/DCCP]: Introduce net_xmit_eval

Throughout the TCP/DCCP (and tunnelling) code, it often happens that the
return code of a transmit function needs to be tested against NET_XMIT_CN
which is a value that does not indicate a strict error condition.

This patch uses a macro for these recurring situations which is consistent
with the already existing macro net_xmit_errno, saving on duplicated code.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>

2 files changed, 2 insertions, 9 deletions

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 2eb58844403c..0ad0904bf56c 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -662,8 +662,7 @@ static int tcp_v4_send_synack(struct sock *sk, struct request_sock *req,
                 err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
                                             ireq->rmt_addr,
                                             ireq->opt);
-                if (err == NET_XMIT_CN)
-                        err = 0;
+                err = net_xmit_eval(err);
         }
 
 out:
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index f63e99aac2d5..6a8581ab9a23 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -484,13 +484,7 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
 
         tcp_enter_cwr(sk);
 
-        /* NET_XMIT_CN is special. It does not guarantee,
-         * that this packet is lost. It tells that device
-         * is about to start to drop packets or already
-         * drops some packets of the same priority and
-         * invokes us to send less aggressively.
-         */
-        return err == NET_XMIT_CN ? 0 : err;
+        return net_xmit_eval(err);
 
 #undef SYSCTL_FLAG_TSTAMPS
 #undef SYSCTL_FLAG_WSCALE