bgpd, doc: Allow route-map policy modifications to also affect route reflectors.

By default, attribute modification via route-map policy out is ignored on
reflected routes. This patch provides an option to allow this modification
to occur. Once enabled, it affects all reflected routes.

Signed-off-by: Dinesh G Dutt <ddutt@cumulusnetworks.com>
diff --git a/bgpd/bgp_route.c b/bgpd/bgp_route.c
index d3f1270..e5224dc 100644
--- a/bgpd/bgp_route.c
+++ b/bgpd/bgp_route.c
@@ -1078,9 +1078,9 @@
       info.attr = attr;
 
       /* The route reflector is not allowed to modify the attributes
-	 of the reflected IBGP routes. */
-      if (from->sort == BGP_PEER_IBGP
-	  && peer->sort == BGP_PEER_IBGP)
+	 of the reflected IBGP routes, unless configured to allow it */
+      if ((from->sort == BGP_PEER_IBGP && peer->sort == BGP_PEER_IBGP) &&
+	  !bgp_flag_check(bgp, BGP_FLAG_RR_ALLOW_OUTBOUND_POLICY))
 	{
 	  bgp_attr_dup (&dummy_attr, attr);
 	  info.attr = &dummy_attr;