bgpd: support for redirect ipv6 simpson method

this commit supports [0] where ipv6 address is encoded in nexthop
attribute of nlri, and not in bgp redirect ip extended community. the
community contains only duplicate information or not.
Adding to this, because an action or a rule needs to apply to either
ipv4 or ipv6 flow, modify some internal structures so as to be aware of
which flow needs to be filtered. This work is needed when an ipv6
flowspec rule without ip addresses is mentioned, we need to know which
afi is served. Also, this work will be useful when doing redirect VRF.

[0] draft-simpson-idr-flowspec-redirect-02.txt

Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>

1 files changed, 29 insertions, 8 deletions

diff --git a/bgpd/bgp_zebra.c b/bgpd/bgp_zebra.c
index 87936f1dd..bf32d493b 100644
--- a/bgpd/bgp_zebra.c
+++ b/bgpd/bgp_zebra.c
@@ -2356,7 +2356,10 @@ static void bgp_encode_pbr_rule_action(struct stream *s,
 				       struct bgp_pbr_rule *pbr)
 {
 	struct prefix pfx;
+	uint8_t fam = AF_INET;
 
+	if (pbra && pbra->nh.type == NEXTHOP_TYPE_IPV6)
+		fam = AF_INET6;
 	stream_putl(s, 0); /* seqno unused */
 	if (pbr)
 		stream_putl(s, pbr->priority);
@@ -2376,7 +2379,7 @@ static void bgp_encode_pbr_rule_action(struct stream *s,
 		memcpy(&pfx, &(pbr->src), sizeof(struct prefix));
 	else {
 		memset(&pfx, 0, sizeof(pfx));
-		pfx.family = AF_INET;
+		pfx.family = fam;
 	}
 	stream_putc(s, pfx.family);
 	stream_putc(s, pfx.prefixlen);
@@ -2388,7 +2391,7 @@ static void bgp_encode_pbr_rule_action(struct stream *s,
 		memcpy(&pfx, &(pbr->dst), sizeof(struct prefix));
 	else {
 		memset(&pfx, 0, sizeof(pfx));
-		pfx.family = AF_INET;
+		pfx.family = fam;
 	}
 	stream_putc(s, pfx.family);
 	stream_putc(s, pfx.prefixlen);
@@ -3063,14 +3066,14 @@ void bgp_zebra_announce_default(struct bgp *bgp, struct nexthop *nh,
 	struct zapi_route api;
 	struct prefix p;
 
-	if (!nh || nh->type != NEXTHOP_TYPE_IPV4
+	if (!nh || (nh->type != NEXTHOP_TYPE_IPV4
+		    && nh->type != NEXTHOP_TYPE_IPV6)
 	    || nh->vrf_id == VRF_UNKNOWN)
 		return;
 	memset(&p, 0, sizeof(struct prefix));
-	/* default route */
-	if (afi != AFI_IP)
+	if (afi != AFI_IP && afi != AFI_IP6)
 		return;
-	p.family = AF_INET;
+	p.family = afi2family(afi);
 	memset(&api, 0, sizeof(api));
 	api.vrf_id = bgp->vrf_id;
 	api.type = ZEBRA_ROUTE_BGP;
@@ -3086,7 +3089,7 @@ void bgp_zebra_announce_default(struct bgp *bgp, struct nexthop *nh,
 	SET_FLAG(api.message, ZAPI_MESSAGE_DISTANCE);
 
 	/* redirect IP */
-	if (nh->gate.ipv4.s_addr != INADDR_ANY) {
+	if (afi == AFI_IP && nh->gate.ipv4.s_addr != INADDR_ANY) {
 		char buff[PREFIX_STRLEN];
 
 		api_nh->vrf_id = nh->vrf_id;
@@ -3095,7 +3098,25 @@ void bgp_zebra_announce_default(struct bgp *bgp, struct nexthop *nh,
 
 		inet_ntop(AF_INET, &(nh->gate.ipv4), buff, INET_ADDRSTRLEN);
 		if (BGP_DEBUG(zebra, ZEBRA))
-			zlog_info("BGP: %s default route to %s table %d (redirect IP)",
+			zlog_debug("BGP: %s default route to %s table %d (redirect IP)",
+				  announce ? "adding" : "withdrawing",
+				  buff, table_id);
+		zclient_route_send(announce ? ZEBRA_ROUTE_ADD
+				   : ZEBRA_ROUTE_DELETE,
+				   zclient, &api);
+	} else if (afi == AFI_IP6 &&
+		   memcmp(&nh->gate.ipv6,
+			  &in6addr_any, sizeof(struct in6_addr))) {
+		char buff[PREFIX_STRLEN];
+
+		api_nh->vrf_id = nh->vrf_id;
+		memcpy(&api_nh->gate.ipv6, &nh->gate.ipv6,
+		       sizeof(struct in6_addr));
+		api_nh->type = NEXTHOP_TYPE_IPV6;
+
+		inet_ntop(AF_INET6, &(nh->gate.ipv6), buff, INET_ADDRSTRLEN);
+		if (BGP_DEBUG(zebra, ZEBRA))
+			zlog_debug("BGP: %s default route to %s table %d (redirect IP)",
 				  announce ? "adding" : "withdrawing",
 				  buff, table_id);
 		zclient_route_send(announce ? ZEBRA_ROUTE_ADD