ipv6: handle Redirect ICMP Message with no Redirected Header option

rfc 4861 says the Redirected Header option is optional, so
the kernel should not drop the Redirect Message that has no
Redirected Header option. In this patch, the function
ip6_redirect_no_header() is introduced to deal with that
condition.

Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>

diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
index 260f83f16bcfb3e79f2572604fc373c1830e2310..f667248202b6be9aacd3dc51f93eb43c9936a217 100644 (file)
--- a/include/net/ip6_route.h
+++ b/include/net/ip6_route.h
@@ -135,6 +135,8 @@ extern void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu,
 extern void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk,
                               __be32 mtu);
 extern void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark);
+extern void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif,
+                                  u32 mark);
 extern void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk);
 
 struct netlink_callback;

diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 79aa9652ed86d9cac754366c075800fbbe4aca1b..04d31c2fbef1ede543bbc4942873722f66a9b524 100644 (file)
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1369,8 +1369,10 @@ static void ndisc_redirect_rcv(struct sk_buff *skb)
        if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts))
                return;
 
-       if (!ndopts.nd_opts_rh)
+       if (!ndopts.nd_opts_rh) {
+               ip6_redirect_no_header(skb, dev_net(skb->dev), 0, 0);
                return;
+       }
 
        hdr = (u8 *)ndopts.nd_opts_rh;
        hdr += 8;

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index b70f8979003b5e23c4b1e78e44713ba3d3520de9..8d9a93ed9c5926924b809b5bb68b267c07f3ca61 100644 (file)
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1178,6 +1178,27 @@ void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark)
 }
 EXPORT_SYMBOL_GPL(ip6_redirect);
 
+void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif,
+                           u32 mark)
+{
+       const struct ipv6hdr *iph = ipv6_hdr(skb);
+       const struct rd_msg *msg = (struct rd_msg *)icmp6_hdr(skb);
+       struct dst_entry *dst;
+       struct flowi6 fl6;
+
+       memset(&fl6, 0, sizeof(fl6));
+       fl6.flowi6_oif = oif;
+       fl6.flowi6_mark = mark;
+       fl6.flowi6_flags = 0;
+       fl6.daddr = msg->dest;
+       fl6.saddr = iph->daddr;
+
+       dst = ip6_route_output(net, NULL, &fl6);
+       if (!dst->error)
+               rt6_do_redirect(dst, NULL, skb);
+       dst_release(dst);
+}
+
 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk)
 {
        ip6_redirect(skb, sock_net(sk), sk->sk_bound_dev_if, sk->sk_mark);