Implements router advertisements activated by received routes.

The RAdv protocol could be configured to change its behavior based on
availability of routes, e.g., do not announce router lifetime when a
default route is not available.

1 files changed, 18 insertions, 14 deletions

diff --git a/proto/radv/packets.c b/proto/radv/packets.c
index 6fdfcaa3..dd839536 100644
--- a/proto/radv/packets.c
+++ b/proto/radv/packets.c
@@ -240,6 +240,7 @@ radv_prepare_ra(struct radv_iface *ifa)
 {
   struct proto_radv *ra = ifa->ra;
   struct radv_config *cf = (struct radv_config *) (ra->p.cf);
+  struct radv_iface_config *ic = ifa->cf;
 
   char *buf = ifa->sk->tbuf;
   char *bufstart = buf;
@@ -249,21 +250,22 @@ radv_prepare_ra(struct radv_iface *ifa)
   pkt->type = ICMPV6_RA;
   pkt->code = 0;
   pkt->checksum = 0;
-  pkt->current_hop_limit = ifa->cf->current_hop_limit;
-  pkt->flags = (ifa->cf->managed ? OPT_RA_MANAGED : 0) |
-    (ifa->cf->other_config ? OPT_RA_OTHER_CFG : 0);
-  pkt->router_lifetime = htons(ifa->cf->default_lifetime);
-  pkt->reachable_time = htonl(ifa->cf->reachable_time);
-  pkt->retrans_timer = htonl(ifa->cf->retrans_timer);
+  pkt->current_hop_limit = ic->current_hop_limit;
+  pkt->flags = (ic->managed ? OPT_RA_MANAGED : 0) |
+    (ic->other_config ? OPT_RA_OTHER_CFG : 0);
+  pkt->router_lifetime = (ra->active || !ic->default_lifetime_sensitive) ?
+    htons(ic->default_lifetime) : 0;
+  pkt->reachable_time = htonl(ic->reachable_time);
+  pkt->retrans_timer = htonl(ic->retrans_timer);
   buf += sizeof(*pkt);
 
-  if (ifa->cf->link_mtu)
+  if (ic->link_mtu)
   {
     struct radv_opt_mtu *om = (void *) buf;
     om->type = OPT_MTU;
     om->length = 1;
     om->reserved = 0;
-    om->mtu = htonl(ifa->cf->link_mtu);
+    om->mtu = htonl(ic->link_mtu);
     buf += sizeof (*om);
   }
 
@@ -288,26 +290,28 @@ radv_prepare_ra(struct radv_iface *ifa)
     op->pxlen = addr->pxlen;
     op->flags = (pc->onlink ? OPT_PX_ONLINK : 0) |
       (pc->autonomous ? OPT_PX_AUTONOMOUS : 0);
-    op->valid_lifetime = htonl(pc->valid_lifetime);
-    op->preferred_lifetime = htonl(pc->preferred_lifetime);
+    op->valid_lifetime = (ra->active || !pc->valid_lifetime_sensitive) ?
+      htonl(pc->valid_lifetime) : 0;
+    op->preferred_lifetime = (ra->active || !pc->preferred_lifetime_sensitive) ?
+      htonl(pc->preferred_lifetime) : 0;
     op->reserved = 0;
     op->prefix = addr->prefix;
     ipa_hton(op->prefix);
     buf += sizeof(*op);
   }
 
-  if (! ifa->cf->rdnss_local)
+  if (! ic->rdnss_local)
     if (radv_prepare_rdnss(ifa, &cf->rdnss_list, &buf, bufend) < 0)
       goto done;
 
-  if (radv_prepare_rdnss(ifa, &ifa->cf->rdnss_list, &buf, bufend) < 0)
+  if (radv_prepare_rdnss(ifa, &ic->rdnss_list, &buf, bufend) < 0)
     goto done;
 
-  if (! ifa->cf->dnssl_local)
+  if (! ic->dnssl_local)
     if (radv_prepare_dnssl(ifa, &cf->dnssl_list, &buf, bufend) < 0)
       goto done;
 
-  if (radv_prepare_dnssl(ifa, &ifa->cf->dnssl_list, &buf, bufend) < 0)
+  if (radv_prepare_dnssl(ifa, &ic->dnssl_list, &buf, bufend) < 0)
     goto done;
 
  done: