bgpd: add functions related to srte_color management

Signed-off-by: Francois Dumontet <francois.dumontet@6wind.com>

bgpd/bgp_attr.c

@@ -2206,6 +2206,16 @@ cluster_list_ignore:
 	return bgp_attr_ignore(peer, args->type);
 }
 
+/* get locally configure or received srte-color value*/
+uint32_t bgp_attr_get_color(struct attr *attr)
+{
+	if (attr->srte_color)
+		return attr->srte_color;
+	if (attr->ecommunity)
+		return ecommunity_select_color(attr->ecommunity);
+	return 0;
+}
+
 /* Multiprotocol reachability information parse. */
 int bgp_mp_reach_parse(struct bgp_attr_parser_args *args,
 		       struct bgp_nlri *mp_update)

bgpd/bgp_attr.h

@@ -466,6 +466,8 @@ extern void bgp_packet_mpunreach_end(struct stream *s, size_t attrlen_pnt);
 extern enum bgp_attr_parse_ret bgp_attr_nexthop_valid(struct peer *peer,
 						      struct attr *attr);
 
+extern uint32_t bgp_attr_get_color(struct attr *attr);
+
 static inline bool bgp_rmap_nhop_changed(uint32_t out_rmap_flags,
 					 uint32_t in_rmap_flags)
 {

bgpd/bgp_ecommunity.c

@@ -1420,6 +1420,29 @@ bool ecommunity_match(const struct ecommunity *ecom1,
 		return false;
 }
 
+/* return last occurence of color */
+/* it will be the greatest color value */
+extern uint32_t ecommunity_select_color(const struct ecommunity *ecom)
+{
+
+	uint32_t aux_color = 0;
+	uint8_t *p;
+	uint32_t c = 0;
+
+	/* If the value already exists in the structure return 0.  */
+
+	for (p = ecom->val; c < ecom->size; p += ecom->unit_size, c++) {
+		if (p == NULL)
+			break;
+
+		if (p[0] == ECOMMUNITY_ENCODE_OPAQUE &&
+		    p[1] == ECOMMUNITY_COLOR)
+			ptr_get_be32((const uint8_t *)&p[4], &aux_color);
+	}
+	return aux_color;
+}
+
+
 /* return first occurence of type */
 extern struct ecommunity_val *ecommunity_lookup(const struct ecommunity *ecom,
 						uint8_t type, uint8_t subtype)

bgpd/bgp_ecommunity.h

@@ -349,6 +349,7 @@ extern char *ecommunity_str(struct ecommunity *ecom);
 extern struct ecommunity_val *ecommunity_lookup(const struct ecommunity *,
 						uint8_t, uint8_t);
 
+extern uint32_t ecommunity_select_color(const struct ecommunity *ecom);
 extern bool ecommunity_add_val(struct ecommunity *ecom,
 			       struct ecommunity_val *eval,
 			       bool unique, bool overwrite);

bgpd/bgp_nht.c

@@ -32,6 +32,7 @@
 #include "bgpd/bgp_evpn.h"
 #include "bgpd/bgp_rd.h"
 #include "bgpd/bgp_mplsvpn.h"
+#include "bgpd/bgp_ecommunity.h"
 
 extern struct zclient *zclient;
 
@@ -321,7 +322,10 @@ int bgp_find_or_add_nexthop(struct bgp *bgp_route, struct bgp *bgp_nexthop,
 			return 0;
 		}
 
-		srte_color = pi->attr->srte_color;
+		if (CHECK_FLAG(pi->attr->flag,
+			       ATTR_FLAG_BIT(BGP_ATTR_SRTE_COLOR)))
+			srte_color = bgp_attr_get_color(pi->attr);
+
 	} else if (peer) {
 		/*
 		 * Gather the ifindex for if up/down events to be
@@ -1238,9 +1242,9 @@ void evaluate_paths(struct bgp_nexthop_cache *bnc)
 		else if (bpi_ultimate->extra)
 			bpi_ultimate->extra->igpmetric = 0;
 
-		if (CHECK_FLAG(bnc->change_flags, BGP_NEXTHOP_METRIC_CHANGED)
+		if (CHECK_FLAG(bnc->change_flags, BGP_NEXTHOP_METRIC_CHANGED) ||
-		    || CHECK_FLAG(bnc->change_flags, BGP_NEXTHOP_CHANGED)
+		    CHECK_FLAG(bnc->change_flags, BGP_NEXTHOP_CHANGED) ||
-		    || path->attr->srte_color != 0)
+		    bgp_attr_get_color(path->attr))
 			SET_FLAG(path->flags, BGP_PATH_IGP_CHANGED);
 
 		path_valid = CHECK_FLAG(path->flags, BGP_PATH_VALID);

bgpd/bgp_zebra.c

@@ -1440,7 +1440,7 @@ void bgp_zebra_announce(struct bgp_dest *dest, const struct prefix *p,
 
 		if (CHECK_FLAG(info->attr->flag,
 			       ATTR_FLAG_BIT(BGP_ATTR_SRTE_COLOR)))
-			api_nh->srte_color = info->attr->srte_color;
+			api_nh->srte_color = bgp_attr_get_color(info->attr);
 
 		if (bgp_debug_zebra(&api.prefix)) {
 			if (mpinfo->extra) {