diff options
| author | Eric Dumazet <edumazet@google.com> | 2015-04-09 13:31:56 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-04-29 10:22:17 +0200 |
| commit | 8e7e388769164149622871ef0c17de842350af5d (patch) | |
| tree | 3c642207f0d693f8c499c52a2220916187bab2ee | |
| parent | 6906cf737301f8837c9ce123595deb8dac1380f5 (diff) | |
| download | lwn-8e7e388769164149622871ef0c17de842350af5d.tar.gz lwn-8e7e388769164149622871ef0c17de842350af5d.zip | |
tcp: tcp_make_synack() should clear skb->tstamp
[ Upstream commit b50edd7812852d989f2ef09dcfc729690f54a42d ]
I noticed tcpdump was giving funky timestamps for locally
generated SYNACK messages on loopback interface.
11:42:46.938990 IP 127.0.0.1.48245 > 127.0.0.2.23850: S
945476042:945476042(0) win 43690 <mss 65495,nop,nop,sackOK,nop,wscale 7>
20:28:58.502209 IP 127.0.0.2.23850 > 127.0.0.1.48245: S
3160535375:3160535375(0) ack 945476043 win 43690 <mss
65495,nop,nop,sackOK,nop,wscale 7>
This is because we need to clear skb->tstamp before
entering lower stack, otherwise net_timestamp_check()
does not set skb->tstamp.
Fixes: 7faee5c0d514 ("tcp: remove TCP_SKB_CB(skb)->when")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/ipv4/tcp_output.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 1db253e36045..d520492ba698 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2929,6 +2929,8 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst, } #endif + /* Do not fool tcpdump (if any), clean our debris */ + skb->tstamp.tv64 = 0; return skb; } EXPORT_SYMBOL(tcp_make_synack); |