From 628e341f319f1a64a4639088faba952e4ec8f0a8 Mon Sep 17 00:00:00 2001 From: Hannes Frederic Sowa Date: Wed, 14 Aug 2013 13:05:23 +0200 Subject: xfrm: make local error reporting more robust In xfrm4 and xfrm6 we need to take care about sockets of the other address family. This could happen because a 6in4 or 4in6 tunnel could get protected by ipsec. Because we don't want to have a run-time dependency on ipv6 when only using ipv4 xfrm we have to embed a pointer to the correct local_error function in xfrm_state_afinet and look it up when returning an error depending on the socket address family. Thanks to vi0ss for the great bug report: v2: a) fix two more unsafe interpretations of skb->sk as ipv6 socket (xfrm6_local_dontfrag and __xfrm6_output) v3: a) add an EXPORT_SYMBOL_GPL(xfrm_local_error) to fix a link error when building ipv6 as a module (thanks to Steffen Klassert) Reported-by: Cc: Steffen Klassert Signed-off-by: Hannes Frederic Sowa Signed-off-by: Steffen Klassert --- net/ipv4/xfrm4_output.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'net/ipv4/xfrm4_output.c') diff --git a/net/ipv4/xfrm4_output.c b/net/ipv4/xfrm4_output.c index 327a617d594c..7a5491ffa4de 100644 --- a/net/ipv4/xfrm4_output.c +++ b/net/ipv4/xfrm4_output.c @@ -33,8 +33,7 @@ static int xfrm4_tunnel_check_size(struct sk_buff *skb) mtu = dst_mtu(dst); if (skb->len > mtu) { if (skb->sk) - ip_local_error(skb->sk, EMSGSIZE, ip_hdr(skb)->daddr, - inet_sk(skb->sk)->inet_dport, mtu); + xfrm_local_error(skb, mtu); else icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); @@ -99,3 +98,12 @@ int xfrm4_output(struct sk_buff *skb) x->outer_mode->afinfo->output_finish, !(IPCB(skb)->flags & IPSKB_REROUTED)); } + +void xfrm4_local_error(struct sk_buff *skb, u32 mtu) +{ + struct iphdr *hdr; + + hdr = skb->encapsulation ? inner_ip_hdr(skb) : ip_hdr(skb); + ip_local_error(skb->sk, EMSGSIZE, hdr->daddr, + inet_sk(skb->sk)->inet_dport, mtu); +} -- cgit v1.2.3-59-g8ed1b