From 1aff64715edb8565e99337b842d814d636641b50 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Mon, 28 Aug 2017 17:00:12 +0200 Subject: [PATCH] netfilter: rt: account for tcp header size too This needs to accout for the ipv4/ipv6 header size and the tcp header without options. Fixes: 6b5dc98e8fac0 ("netfilter: rt: add support to fetch path mss") Reported-by: Matteo Croce Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_rt.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/netfilter/nft_rt.c b/net/netfilter/nft_rt.c index 61fd3acaa3c9..a6b7d05aeacf 100644 --- a/net/netfilter/nft_rt.c +++ b/net/netfilter/nft_rt.c @@ -35,10 +35,11 @@ static u16 get_tcpmss(const struct nft_pktinfo *pkt, const struct dst_entry *skb switch (nft_pf(pkt)) { case NFPROTO_IPV4: fl.u.ip4.daddr = ip_hdr(skb)->saddr; - minlen = sizeof(struct iphdr); + minlen = sizeof(struct iphdr) + sizeof(struct tcphdr); break; case NFPROTO_IPV6: fl.u.ip6.daddr = ipv6_hdr(skb)->saddr; + minlen = sizeof(struct ipv6hdr) + sizeof(struct tcphdr); break; }