[PATCH 2/3] network: tcp_connect should return certain errors up thestack

From: Eric Paris
Date: Tue Nov 16 2010 - 16:56:24 EST


The current tcp_connect code completely ignores errors from sending an skb.
This makes sense in many situations (like -ENOBUFFS) but I want to be able to
immediately fail connections if they are denied by the SELinux netfilter hook.
Netfilter does not normally return ECONNREFUSED when it drops a packet so we
respect that error code as a final and fatal error that can not be recovered.

Based-on-patch-by: Patrick McHardy <kaber@xxxxxxxxx>
Signed-off-by: Eric Paris <eparis@xxxxxxxxxx>
---

net/ipv4/tcp_output.c | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index e961522..15dcd7b 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2592,6 +2592,7 @@ int tcp_connect(struct sock *sk)
{
struct tcp_sock *tp = tcp_sk(sk);
struct sk_buff *buff;
+ int err;

tcp_connect_init(sk);

@@ -2614,7 +2615,9 @@ int tcp_connect(struct sock *sk)
sk->sk_wmem_queued += buff->truesize;
sk_mem_charge(sk, buff->truesize);
tp->packets_out += tcp_skb_pcount(buff);
- tcp_transmit_skb(sk, buff, 1, sk->sk_allocation);
+ err = tcp_transmit_skb(sk, buff, 1, sk->sk_allocation);
+ if (err == -ECONNREFUSED)
+ return err;

/* We change tp->snd_nxt after the tcp_transmit_skb() call
* in order to make this packet get counted in tcpOutSegs.

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