path: root/net
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authorSteffen Klassert <steffen.klassert@secunet.com>2009-04-06 03:58:50 +0000
committerDavid S. Miller <davem@davemloft.net>2009-04-06 17:07:59 -0700
commitd1d88e5de491f7b0862a0adaed427211c0e4a0a6 (patch)
tree4706cb6a58d60c9061203f788e074c531fb5362d /net
parent10fd9d7ec48194754de6497ded2ef53cbd2c313e (diff)
xfrm: fix fragmentation on inter family tunnels
If an ipv4 packet (not locally generated with IP_DF flag not set) bigger than mtu size is supposed to go via a xfrm ipv6 tunnel, the packetsize check in xfrm4_tunnel_check_size() is omited and ipv6 drops the packet without sending a notice to the original sender of the ipv4 packet. Another issue is that ipv4 connection tracking does reassembling of incomming fragmented packets. If such a reassembled packet is supposed to go via a xfrm ipv6 tunnel it will be droped, even if the original sender did proper fragmentation. According to RFC 2473 (section 7) tunnel ipv6 packets resulting from the encapsulation of an original packet are considered as locally generated packets. If such a packet passed the checks in xfrm{4,6}_tunnel_check_size() fragmentation is allowed according to RFC 2473 (section 7.1/7.2). This patch sets skb->local_df in xfrm6_prepare_output() to achieve fragmentation in this case. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
1 files changed, 1 insertions, 0 deletions
diff --git a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c
index 0af823cf7f1..5ee5a031bc9 100644
--- a/net/ipv6/xfrm6_output.c
+++ b/net/ipv6/xfrm6_output.c
@@ -72,6 +72,7 @@ int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
skb->protocol = htons(ETH_P_IPV6);
+ skb->local_df = 1;
return x->outer_mode->output2(x, skb);