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>
diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
index eb4a842..6f5fc61 100644
--- a/net/xfrm/xfrm_output.c
+++ b/net/xfrm/xfrm_output.c
@@ -214,5 +214,18 @@
return inner_mode->afinfo->extract_output(x, skb);
}
+void xfrm_local_error(struct sk_buff *skb, int mtu)
+{
+ struct xfrm_state_afinfo *afinfo;
+
+ afinfo = xfrm_state_get_afinfo(skb->sk->sk_family);
+ if (!afinfo)
+ return;
+
+ afinfo->local_error(skb, mtu);
+ xfrm_state_put_afinfo(afinfo);
+}
+
EXPORT_SYMBOL_GPL(xfrm_output);
EXPORT_SYMBOL_GPL(xfrm_inner_extract_output);
+EXPORT_SYMBOL_GPL(xfrm_local_error);