[NETFILTER]: Fix HW checksum handling in TCPMSS target
Most importantly, remove bogus BUG() in receive path.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/netfilter/ipt_TCPMSS.c b/net/ipv4/netfilter/ipt_TCPMSS.c
index 1049050..7b84a25 100644
--- a/net/ipv4/netfilter/ipt_TCPMSS.c
+++ b/net/ipv4/netfilter/ipt_TCPMSS.c
@@ -61,6 +61,10 @@
if (!skb_ip_make_writable(pskb, (*pskb)->len))
return NF_DROP;
+ if ((*pskb)->ip_summed == CHECKSUM_HW &&
+ skb_checksum_help(*pskb, out == NULL))
+ return NF_DROP;
+
iph = (*pskb)->nh.iph;
tcplen = (*pskb)->len - iph->ihl*4;
@@ -186,9 +190,6 @@
newmss);
retmodified:
- /* We never hw checksum SYN packets. */
- BUG_ON((*pskb)->ip_summed == CHECKSUM_HW);
-
(*pskb)->nfcache |= NFC_UNKNOWN | NFC_ALTERED;
return IPT_CONTINUE;
}
