[IPV6] MIP6: Ignore to report if mobility headers is rejected.

Ignore to report user-space for known mobility headers rejected by
destination options header transformation.
Mobile IPv6 specification (RFC3775) says that mobility header
is used with destination options header carrying home address option
only for binding update message. Other type message cannot be used
and node must drop it silently (and must not send binding error) if
receving such packet.
To achieve it, (1) application should use transformation policy and
wild-card states to catch binding update message prior other packets
(2) kernel doesn't report the reject to user-space not to send
binding error message by application.
This patch is for (2).
Based on MIPL2 kernel patch.

This patch was also written by: Ville Nuorvala <vnuorval@tcs.hut.fi>

Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/mip6.c b/net/ipv6/mip6.c
index 31445d09261e402272444f30d58b914da55b303b..70854035c1314bdaa86575283f6f65aace926dd2 100644 (file)
--- a/net/ipv6/mip6.c
+++ b/net/ipv6/mip6.c
@@ -234,6 +234,9 @@ static int mip6_destopt_reject(struct xfrm_state *x, struct sk_buff *skb, struct
        struct timeval stamp;
        int err = 0;
 
+       if (unlikely(fl->proto == IPPROTO_MH && fl->fl_mh_type <= IP6_MH_TYPE_MAX))
+               goto out;
+
        if (likely(opt->dsthao)) {
                offset = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
                if (likely(offset >= 0))