zebra: atomic FIB updates

This commit updates the kernel API so that route changes are
atomically updated using change/replaces messages instead
of first sending a withdraw followed with update.

Same for zclient updates, changes are sent as single ADD
instead of DELETE + ADD.

Signed-off-by: Timo Teräs <timo.teras@iki.fi>

1 files changed, 25 insertions, 44 deletions

diff --git a/zebra/rt_socket.c b/zebra/rt_socket.c
index bf21ca95..00093c2a 100644
--- a/zebra/rt_socket.c
+++ b/zebra/rt_socket.c
@@ -214,34 +214,6 @@ kernel_rtm_ipv4 (int cmd, struct prefix *p, struct rib *rib, int family)
   return 0; /*XXX*/
 }
 
-int
-kernel_add_ipv4 (struct prefix *p, struct rib *rib)
-{
-  int route;
-
-  if (zserv_privs.change(ZPRIVS_RAISE))
-    zlog (NULL, LOG_ERR, "Can't raise privileges");
-  route = kernel_rtm_ipv4 (RTM_ADD, p, rib, AF_INET);
-  if (zserv_privs.change(ZPRIVS_LOWER))
-    zlog (NULL, LOG_ERR, "Can't lower privileges");
-
-  return route;
-}
-
-int
-kernel_delete_ipv4 (struct prefix *p, struct rib *rib)
-{
-  int route;
-
-  if (zserv_privs.change(ZPRIVS_RAISE))
-    zlog (NULL, LOG_ERR, "Can't raise privileges");
-  route = kernel_rtm_ipv4 (RTM_DELETE, p, rib, AF_INET);
-  if (zserv_privs.change(ZPRIVS_LOWER))
-    zlog (NULL, LOG_ERR, "Can't lower privileges");
-
-  return route;
-}
-
 #ifdef HAVE_IPV6
 
 /* Calculate sin6_len value for netmask socket value. */
@@ -384,31 +356,40 @@ kernel_rtm_ipv6_multipath (int cmd, struct prefix *p, struct rib *rib,
   return 0; /*XXX*/
 }
 
+#endif
+
 int
-kernel_add_ipv6 (struct prefix *p, struct rib *rib)
+kernel_route_rib (struct prefix *p, struct rib *old, struct rib *new)
 {
-  int route;
+  struct rib *rib;
+  int route = 0, cmd;
 
-  if (zserv_privs.change(ZPRIVS_RAISE))
-    zlog (NULL, LOG_ERR, "Can't raise privileges");
-  route =  kernel_rtm_ipv6_multipath (RTM_ADD, p, rib, AF_INET6);
-  if (zserv_privs.change(ZPRIVS_LOWER))
-    zlog (NULL, LOG_ERR, "Can't lower privileges");
+  if (!old && new)
+    cmd = RTM_ADD;
+  else if (old && !new)
+    cmd = RTM_DEL;
+  else
+    cmd = RTM_CHANGE;
 
-  return route;
-}
-
-int
-kernel_delete_ipv6 (struct prefix *p, struct rib *rib)
-{
-  int route;
+  rib = new ? new : old;
 
   if (zserv_privs.change(ZPRIVS_RAISE))
     zlog (NULL, LOG_ERR, "Can't raise privileges");
-  route =  kernel_rtm_ipv6_multipath (RTM_DELETE, p, rib, AF_INET6);
+
+  switch (PREFIX_FAMILY(p))
+    {
+    case AF_INET:
+      route = kernel_rtm_ipv4 (cmd, p, rib, AF_INET);
+      break;
+#ifdef HAVE_IPV6
+    case AF_INET6:
+      route = kernel_rtm_ipv6 (cmd, p, rib, AF_INET6);
+      break;
+#endif
+    }
+
   if (zserv_privs.change(ZPRIVS_LOWER))
     zlog (NULL, LOG_ERR, "Can't lower privileges");
 
   return route;
 }
-#endif /* HAVE_IPV6 */