ldpd: remove security check to allow operation on unnumbered interfaces

Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
(cherry picked from commit f25ccbd060a2086678f8608cafc5c5a2a2cf964a)

diff --git a/ldpd/packet.c b/ldpd/packet.c
index ad7818131188fab49bad34ed913c6aeb1e1a0963..be5ed8072baecad966562eb6c3d8b8e7f60623c9 100644 (file)
--- a/ldpd/packet.c
+++ b/ldpd/packet.c
@@ -285,8 +285,6 @@ disc_find_iface(unsigned int ifindex, int af, union ldpd_addr *src,
 {
        struct iface    *iface;
        struct iface_af *ia;
-       struct if_addr  *if_addr;
-       in_addr_t        mask;
 
        iface = if_lookup(leconf, ifindex);
        if (iface == NULL)
@@ -297,41 +295,14 @@ disc_find_iface(unsigned int ifindex, int af, union ldpd_addr *src,
                return (NULL);
 
        /*
-        * For unicast packets, we just need to make sure that the interface
-        * is enabled for the given address-family.
+        * RFC 7552 - Section 5.1:
+        * "Link-local IPv6 address MUST be used as the source IP address in
+        * IPv6 LDP Link Hellos".
         */
-       if (!multicast)
-               return (iface);
-
-       switch (af) {
-       case AF_INET:
-               LIST_FOREACH(if_addr, &iface->addr_list, entry) {
-                       if (if_addr->af != AF_INET)
-                               continue;
-
-                       switch (iface->type) {
-                       case IF_TYPE_POINTOPOINT:
-                               if (if_addr->dstbrd.v4.s_addr == src->v4.s_addr)
-                                       return (iface);
-                               break;
-                       default:
-                               mask = prefixlen2mask(if_addr->prefixlen);
-                               if ((if_addr->addr.v4.s_addr & mask) ==
-                                   (src->v4.s_addr & mask))
-                                       return (iface);
-                               break;
-                       }
-               }
-               break;
-       case AF_INET6:
-               if (IN6_IS_ADDR_LINKLOCAL(&src->v6))
-                       return (iface);
-               break;
-       default:
-               fatalx("disc_find_iface: unknown af");
-       }
+       if (multicast && af == AF_INET6 && !IN6_IS_ADDR_LINKLOCAL(&src->v6))
+               return (NULL);
 
-       return (NULL);
+       return (iface);
 }
 
 int