act_nat: fix the wrong checksum when addr isn't in old_addr/mask
fix the wrong checksum when addr isn't in old_addr/mask
For TCP and UDP packets, when addr isn't in old_addr/mask we don't do SNAT or
DNAT, and we should not update layer 4 checksum.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
----
net/sched/act_nat.c | 4 ++++
1 file changed, 4 insertions(+)
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/act_nat.c b/net/sched/act_nat.c
index d885ba3..5709494 100644
--- a/net/sched/act_nat.c
+++ b/net/sched/act_nat.c
@@ -159,6 +159,9 @@
iph->daddr = new_addr;
csum_replace4(&iph->check, addr, new_addr);
+ } else if ((iph->frag_off & htons(IP_OFFSET)) ||
+ iph->protocol != IPPROTO_ICMP) {
+ goto out;
}
ihl = iph->ihl * 4;
@@ -247,6 +250,7 @@
break;
}
+out:
return action;
drop: