From: vivek <vivek@cumulusnetworks.com>
Date: Fri, 13 May 2016 01:31:19 +0000 (-0700)
Subject: Revert "Zebra: Update/fix router_lifetime in IPv6 RAs"
X-Git-Tag: frr-2.0-rc1~918
X-Git-Url: https://git.puffer.fish/?a=commitdiff_plain;h=6b9efc026fe0632d580672e3182e614aef935ac8;p=mirror%2Ffrr.git

Revert "Zebra: Update/fix router_lifetime in IPv6 RAs"

This reverts commit 690baa53592320dddee5c729f959150cc9a72699.

Making the router lifetime in the IPv6 RAs as 0 by default would break BGP
unnumbered when this version of Quagga goes up against a 2.5.x Quagga. This
is because of a defect in the Quagga code that ignores any received RAs with
a lifetime of 0.
---

diff --git a/zebra/rtadv.c b/zebra/rtadv.c
index d4d48988c7..02499a3557 100644
--- a/zebra/rtadv.c
+++ b/zebra/rtadv.c
@@ -189,14 +189,8 @@ rtadv_send_packet (int sock, struct interface *ifp)
   rtadv->nd_ra_curhoplimit = 64;
 
   /* RFC4191: Default Router Preference is 0 if Router Lifetime is 0. */
-#if defined(HAVE_CUMULUS)
-  /* Uninitialized (default) lifetime means 0. */
-  rtadv->nd_ra_flags_reserved =
-    zif->rtadv.AdvDefaultLifetime <= 0 ? 0 : zif->rtadv.DefaultPreference;
-#else
   rtadv->nd_ra_flags_reserved =
     zif->rtadv.AdvDefaultLifetime == 0 ? 0 : zif->rtadv.DefaultPreference;
-#endif
   rtadv->nd_ra_flags_reserved <<= 3;
 
   if (zif->rtadv.AdvManagedFlag)
@@ -213,15 +207,9 @@ rtadv_send_packet (int sock, struct interface *ifp)
    * value for this field.  To prevent this, routers SHOULD keep
    * AdvDefaultLifetime in at least one second, even if the use of
    * MaxRtrAdvInterval would result in a smaller value. -- RFC6275, 7.5 */
-#if defined(HAVE_CUMULUS)
-  /* Uninitialized (default) lifetime means 0. */
-  pkt_RouterLifetime = zif->rtadv.AdvDefaultLifetime != -1 ?
-    zif->rtadv.AdvDefaultLifetime : 0;
-#else
   pkt_RouterLifetime = zif->rtadv.AdvDefaultLifetime != -1 ?
     zif->rtadv.AdvDefaultLifetime :
     MAX (1, 0.003 * zif->rtadv.MaxRtrAdvInterval);
-#endif
   rtadv->nd_ra_router_lifetime = htons (pkt_RouterLifetime);
   rtadv->nd_ra_reachable = htonl (zif->rtadv.AdvReachableTime);
   rtadv->nd_ra_retransmit = htonl (0);
@@ -460,7 +448,6 @@ rtadv_process_advert (u_char *msg, unsigned int len, struct interface *ifp,
   struct nd_router_advert *radvert;
   char addr_str[INET6_ADDRSTRLEN];
   struct zebra_if *zif;
-  struct prefix p;
 
   zif = ifp->info;
 
@@ -514,13 +501,15 @@ rtadv_process_advert (u_char *msg, unsigned int len, struct interface *ifp,
                 ifp->name, ifp->ifindex, addr_str);
     }
 
-  /* Create entry for neighbor if not known. */
-  p.family = AF_INET6;
-  IPV6_ADDR_COPY (&p.u.prefix, &addr->sin6_addr);
-  p.prefixlen = IPV6_MAX_PREFIXLEN;
+  /* Currently supporting only P2P links, so any new RA source address is
+     considered as the replacement of the previously learnt Link-Local address.
+     As per the RFC, lifetime zero is to be considered a delete */
+  if (ntohs(radvert->nd_ra_router_lifetime))
+     nbr_connected_replacement_add_ipv6(ifp, &addr->sin6_addr, 128);
+  else
+     nbr_connected_delete_ipv6(ifp, &addr->sin6_addr, 128);
 
-  if (!nbr_connected_check(ifp, &p))
-    nbr_connected_add_ipv6 (ifp, &addr->sin6_addr);
+  return;
 }
 
 
diff --git a/zebra/zserv.c b/zebra/zserv.c
index d6de0792e1..e9698a82a8 100644
--- a/zebra/zserv.c
+++ b/zebra/zserv.c
@@ -471,16 +471,21 @@ zsend_interface_vrf_update (struct zserv *client, struct interface *ifp,
   return zebra_server_send_message(client);
 }
 
-/* Add new nbr connected IPv6 address */
+/* Add new nbr connected IPv6 address if none exists already, or replace the
+   existing one if an ifc entry is found on the interface. */
 void
-nbr_connected_add_ipv6 (struct interface *ifp, struct in6_addr *address)
+nbr_connected_replacement_add_ipv6 (struct interface *ifp, struct in6_addr *address,
+                                    u_char prefixlen)
 {
   struct nbr_connected *ifc;
   struct prefix p;
 
   p.family = AF_INET6;
   IPV6_ADDR_COPY (&p.u.prefix, address);
-  p.prefixlen = IPV6_MAX_PREFIXLEN;
+  p.prefixlen = prefixlen;
+
+  if (nbr_connected_check(ifp, &p))
+    return;
 
   if (!(ifc = listnode_head(ifp->nbr_connected)))
     {
@@ -499,14 +504,15 @@ nbr_connected_add_ipv6 (struct interface *ifp, struct in6_addr *address)
 }
 
 void
-nbr_connected_delete_ipv6 (struct interface *ifp, struct in6_addr *address)
+nbr_connected_delete_ipv6 (struct interface *ifp, struct in6_addr *address,
+                           u_char prefixlen)
 {
   struct nbr_connected *ifc;
   struct prefix p;
 
   p.family = AF_INET6;
   IPV6_ADDR_COPY (&p.u.prefix, address);
-  p.prefixlen = IPV6_MAX_PREFIXLEN;
+  p.prefixlen = prefixlen;
 
   ifc = nbr_connected_check(ifp, &p);
   if (!ifc)
diff --git a/zebra/zserv.h b/zebra/zserv.h
index 16700ee523..7fde4adb5e 100644
--- a/zebra/zserv.h
+++ b/zebra/zserv.h
@@ -155,8 +155,9 @@ extern int zsend_interface_delete (struct zserv *, struct interface *);
 extern int zsend_interface_addresses (struct zserv *, struct interface *);
 extern int zsend_interface_address (int, struct zserv *, struct interface *,
                                     struct connected *);
-extern void nbr_connected_add_ipv6 (struct interface *, struct in6_addr *);
-extern void nbr_connected_delete_ipv6 (struct interface *, struct in6_addr *);
+extern void nbr_connected_replacement_add_ipv6 (struct interface *,
+                                                struct in6_addr *, u_char);
+extern void nbr_connected_delete_ipv6 (struct interface *, struct in6_addr *, u_char);
 extern int zsend_interface_update (int, struct zserv *, struct interface *);
 extern int zsend_redistribute_route (int, struct zserv *, struct prefix *,
 				     struct rib *);