[IPV6]: Add ifindex field to ND user option messages.

Userland neighbor discovery options are typically heavily involved with
the interface on which thay are received: add a missing ifindex field to
the original struct. Thanks to Rémi Denis-Courmont.

Signed-off-by: Pierre Ynard <linkfanel@yahoo.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 3 insertions, 0 deletions

diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index 5bf618241ab9..4e81836191df 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -491,9 +491,11 @@ struct nduseroptmsg
         unsigned char   nduseropt_family;
         unsigned char   nduseropt_pad1;
         unsigned short  nduseropt_opts_len;     /* Total length of options */
+        int             nduseropt_ifindex;
         __u8            nduseropt_icmp_type;
         __u8            nduseropt_icmp_code;
         unsigned short  nduseropt_pad2;
+        unsigned int    nduseropt_pad3;
         /* Followed by one or more ND options */
 };
 
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 36f7dbfb6dbb..67997a74ddce 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1037,6 +1037,7 @@ static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
 
         ndmsg = nlmsg_data(nlh);
         ndmsg->nduseropt_family = AF_INET6;
+        ndmsg->nduseropt_ifindex = ra->dev->ifindex;
         ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
         ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
         ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;