path: root/net/ipv4/xfrm4_output.c
diff options
authorHannes Frederic Sowa <hannes@stressinduktion.org>2013-08-14 13:05:23 +0200
committerSteffen Klassert <steffen.klassert@secunet.com>2013-08-14 13:07:12 +0200
commit628e341f319f1a64a4639088faba952e4ec8f0a8 (patch)
tree28fd4b1a02ca00a1abe0b1e71898ab8db6a81dad /net/ipv4/xfrm4_output.c
parenttun: compare with 0 instead of total_len (diff)
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: <https://bugzilla.kernel.org/show_bug.cgi?id=58691> 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: <vi0oss@gmail.com> Cc: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Diffstat (limited to 'net/ipv4/xfrm4_output.c')
1 files changed, 10 insertions, 2 deletions
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);
icmp_send(skb, ICMP_DEST_UNREACH,
ICMP_FRAG_NEEDED, htonl(mtu));
@@ -99,3 +98,12 @@ int xfrm4_output(struct sk_buff *skb)
!(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);