lib, ospfd, ospf6d, zebra: add OSPF opaque route attributes

Update ospfd and ospf6d to send opaque route attributes to
zebra. Those attributes are stored in the RIB and can be viewed
using the "show ip[v6] route" commands (other than that, they are
completely ignored by zebra).

Example:
```
debian# show ip route 192.168.1.0/24
Routing entry for 192.168.1.0/24
  Known via "ospf", distance 110, metric 20, best
  Last update 01:57:08 ago
  * 10.0.1.2, via eth-rt2, weight 1
    OSPF path type        : External-2
    OSPF tag              : 0

debian#
debian# show ip route 192.168.1.0/24 json
{
  "192.168.1.0\/24":[
    {
      "prefix":"192.168.1.0\/24",
      "prefixLen":24,
      "protocol":"ospf",
      "vrfId":0,
      "vrfName":"default",
      "selected":true,
      [snip]
      "ospfPathType":"External-2",
      "ospfTag":"0"
    }
  ]
}
```

Signed-off-by: Renato Westphal <renato@opensourcerouting.org>

1 files changed, 36 insertions, 0 deletions

diff --git a/ospfd/ospf_zebra.c b/ospfd/ospf_zebra.c
index b0ed66da5f..7834b7d934 100644
--- a/ospfd/ospf_zebra.c
+++ b/ospfd/ospf_zebra.c
@@ -33,6 +33,7 @@
 #include "filter.h"
 #include "plist.h"
 #include "log.h"
+#include "route_opaque.h"
 #include "lib/bfd.h"
 #include "nexthop.h"
 
@@ -255,6 +256,38 @@ static void ospf_zebra_add_nexthop(struct ospf *ospf, struct ospf_path *path,
 	api->nexthop_num++;
 }
 
+static void ospf_zebra_append_opaque_attr(struct ospf_route *or,
+					  struct zapi_route *api)
+{
+	struct ospf_zebra_opaque ospf_opaque = {};
+
+	/* OSPF path type */
+	snprintf(ospf_opaque.path_type, sizeof(ospf_opaque.path_type), "%s",
+		 ospf_path_type_name(or->path_type));
+
+	switch (or->path_type) {
+	case OSPF_PATH_INTRA_AREA:
+	case OSPF_PATH_INTER_AREA:
+		/* OSPF area ID */
+		(void)inet_ntop(AF_INET, &or->u.std.area_id,
+				ospf_opaque.area_id,
+				sizeof(ospf_opaque.area_id));
+		break;
+	case OSPF_PATH_TYPE1_EXTERNAL:
+	case OSPF_PATH_TYPE2_EXTERNAL:
+		/* OSPF route tag */
+		snprintf(ospf_opaque.tag, sizeof(ospf_opaque.tag), "%u",
+			 or->u.ext.tag);
+		break;
+	default:
+		break;
+	}
+
+	SET_FLAG(api->message, ZAPI_MESSAGE_OPAQUE);
+	api->opaque.length = sizeof(struct ospf_zebra_opaque);
+	memcpy(api->opaque.data, &ospf_opaque, api->opaque.length);
+}
+
 void ospf_zebra_add(struct ospf *ospf, struct prefix_ipv4 *p,
 		    struct ospf_route * or)
 {
@@ -322,6 +355,9 @@ void ospf_zebra_add(struct ospf *ospf, struct prefix_ipv4 *p,
 		}
 	}
 
+	if (CHECK_FLAG(ospf->config, OSPF_SEND_EXTRA_DATA_TO_ZEBRA))
+		ospf_zebra_append_opaque_attr(or, &api);
+
 	zclient_route_send(ZEBRA_ROUTE_ADD, zclient, &api);
 }