diff options
| author | Eric Dumazet <edumazet@google.com> | 2016-01-15 08:21:32 -0800 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2016-01-18 12:18:17 +0100 |
| commit | d6b3347bf178266259af64b1f27b5cf54acf62c8 (patch) | |
| tree | 73511ca46445418d5dba23d91ebfb4371b679593 /net/netfilter | |
| parent | efaea94aaf0decd55b15aa7068d4d516a352e56e (diff) | |
| download | linux-d6b3347bf178266259af64b1f27b5cf54acf62c8.tar.gz | |
netfilter: xt_TCPMSS: handle CHECKSUM_COMPLETE in tcpmss_tg6()
In case MSS option is added in TCP options, skb length increases by 4. IPv6 needs to update skb->csum if skb has CHECKSUM_COMPLETE, otherwise kernel complains loudly in netdev_rx_csum_fault() with a stack dump. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/netfilter')
| -rw-r--r-- | net/netfilter/xt_TCPMSS.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/net/netfilter/xt_TCPMSS.c b/net/netfilter/xt_TCPMSS.c index b7c43def0dc6..e118397254af 100644 --- a/net/netfilter/xt_TCPMSS.c +++ b/net/netfilter/xt_TCPMSS.c @@ -228,7 +228,7 @@ tcpmss_tg6(struct sk_buff *skb, const struct xt_action_param *par) { struct ipv6hdr *ipv6h = ipv6_hdr(skb); u8 nexthdr; - __be16 frag_off; + __be16 frag_off, oldlen, newlen; int tcphoff; int ret; @@ -244,7 +244,12 @@ tcpmss_tg6(struct sk_buff *skb, const struct xt_action_param *par) return NF_DROP; if (ret > 0) { ipv6h = ipv6_hdr(skb); - ipv6h->payload_len = htons(ntohs(ipv6h->payload_len) + ret); + oldlen = ipv6h->payload_len; + newlen = htons(ntohs(oldlen) + ret); + if (skb->ip_summed == CHECKSUM_COMPLETE) + skb->csum = csum_add(csum_sub(skb->csum, oldlen), + newlen); + ipv6h->payload_len = newlen; } return XT_CONTINUE; } |