[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>

3 files changed, 5 insertions, 17 deletions

diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index bc400b2ba25e..61c09014dade 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -501,8 +501,7 @@ static int dccp_v4_send_response(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:
@@ -571,7 +570,7 @@ static void dccp_v4_ctl_send_reset(struct sk_buff *rxskb)
                                     rxskb->nh.iph->saddr, NULL);
         bh_unlock_sock(dccp_v4_ctl_socket->sk);
 
-        if (err == NET_XMIT_CN || err == 0) {
+        if (net_xmit_eval(err) == 0) {
                 DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
                 DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
         }
diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index 8d6ddb6389a7..2165b1740c7c 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -294,8 +294,7 @@ static int dccp_v6_send_response(struct sock *sk, struct request_sock *req,
                                                          &ireq6->rmt_addr);
                 ipv6_addr_copy(&fl.fl6_dst, &ireq6->rmt_addr);
                 err = ip6_xmit(sk, skb, &fl, opt, 0);
-                if (err == NET_XMIT_CN)
-                        err = 0;
+                err = net_xmit_eval(err);
         }
 
 done:
diff --git a/net/dccp/output.c b/net/dccp/output.c
index 0994b13f0f15..ef22f3cc791a 100644
--- a/net/dccp/output.c
+++ b/net/dccp/output.c
@@ -125,16 +125,7 @@ static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
 
                 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
                 err = icsk->icsk_af_ops->queue_xmit(skb, sk, 0);
-                if (err <= 0)
-                        return err;
-
-                /* 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);
         }
         return -ENOBUFS;
 }
@@ -426,8 +417,7 @@ int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code)
                 if (skb != NULL) {
                         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
                         err = inet_csk(sk)->icsk_af_ops->queue_xmit(skb, sk, 0);
-                        if (err == NET_XMIT_CN)
-                                err = 0;
+                        return net_xmit_eval(err);
                 }
         }