1 files changed, 70 insertions, 5 deletions

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 563f12c1c99..73cf3f78aaa 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1690,14 +1690,78 @@ static struct rt6_info *ip6_route_redirect(const struct in6_addr *dest,
                                                    flags, __ip6_route_redirect);
 }
 
-void rt6_redirect(const struct in6_addr *dest, const struct in6_addr *src,
-                  const struct in6_addr *saddr,
-                  struct neighbour *neigh, u8 *lladdr, int on_link)
+void rt6_redirect(struct sk_buff *skb)
 {
-        struct rt6_info *rt, *nrt = NULL;
+        struct net *net = dev_net(skb->dev);
         struct netevent_redirect netevent;
-        struct net *net = dev_net(neigh->dev);
+        struct rt6_info *rt, *nrt = NULL;
+        const struct in6_addr *target;
         struct neighbour *old_neigh;
+        const struct in6_addr *dest;
+        const struct in6_addr *src;
+        const struct in6_addr *saddr;
+        struct ndisc_options ndopts;
+        struct inet6_dev *in6_dev;
+        struct neighbour *neigh;
+        struct icmp6hdr *icmph;
+        int on_link, optlen;
+        u8 *lladdr = NULL;
+
+        optlen = skb->tail - skb->transport_header;
+        optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
+
+        if (optlen < 0) {
+                net_dbg_ratelimited("rt6_redirect: packet too short\n");
+                return;
+        }
+
+        icmph = icmp6_hdr(skb);
+        target = (const struct in6_addr *) (icmph + 1);
+        dest = target + 1;
+
+        if (ipv6_addr_is_multicast(dest)) {
+                net_dbg_ratelimited("rt6_redirect: destination address is multicast\n");
+                return;
+        }
+
+        if (ipv6_addr_equal(dest, target)) {
+                on_link = 1;
+        } else if (ipv6_addr_type(target) !=
+                   (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
+                net_dbg_ratelimited("rt6_redirect: target address is not link-local unicast\n");
+                return;
+        }
+
+        in6_dev = __in6_dev_get(skb->dev);
+        if (!in6_dev)
+                return;
+        if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects)
+                return;
+
+        /* RFC2461 8.1:
+         *      The IP source address of the Redirect MUST be the same as the current
+         *      first-hop router for the specified ICMP Destination Address.
+         */
+
+        if (!ndisc_parse_options((u8*)(dest + 1), optlen, &ndopts)) {
+                net_dbg_ratelimited("rt6_redirect: invalid ND options\n");
+                return;
+        }
+        if (ndopts.nd_opts_tgt_lladdr) {
+                lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
+                                             skb->dev);
+                if (!lladdr) {
+                        net_dbg_ratelimited("rt6_redirect: invalid link-layer address length\n");
+                        return;
+                }
+        }
+
+        neigh = __neigh_lookup(&nd_tbl, target, skb->dev, 1);
+        if (!neigh)
+                return;
+
+        src = &ipv6_hdr(skb)->daddr;
+        saddr = &ipv6_hdr(skb)->saddr;
 
         rt = ip6_route_redirect(dest, src, saddr, neigh->dev);
 
@@ -1756,6 +1820,7 @@ void rt6_redirect(const struct in6_addr *dest, const struct in6_addr *src,
         }
 
 out:
+        neigh_release(neigh);
         dst_release(&rt->dst);
 }