zebra: add ZEBRA_IPV4_NEXTHOP_LOOKUP_MRIB
This adds a new zapi call "ZEBRA_IPV4_NEXTHOP_LOOKUP_MRIB" performing a
Multicast RPF lookup for a given source. Details of the lookup
behaviour are left to the zebra side of things.
Note: this is non-reactive, as in, only delivers a snapshot of the state
at a particular point in time. There's no push notification of changes
happening to the RIB.
This combines the following 3 original patches:
- zebra: add zsend_ipv4_nexthop_lookup_mrib()
- zserv: Query mrib (SAFI_MULTICAST).
- zebra: Cleanups to zebra_rib.
Cc: Everton Marques <everton.marques@gmail.com>
Cc: Balaji G <balajig81@gmail.com>
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
diff --git a/lib/zebra.h b/lib/zebra.h
index b289a19..a4e0214 100644
--- a/lib/zebra.h
+++ b/lib/zebra.h
@@ -425,7 +425,8 @@
#define ZEBRA_ROUTER_ID_DELETE 21
#define ZEBRA_ROUTER_ID_UPDATE 22
#define ZEBRA_HELLO 23
-#define ZEBRA_MESSAGE_MAX 24
+#define ZEBRA_IPV4_NEXTHOP_LOOKUP_MRIB 24
+#define ZEBRA_MESSAGE_MAX 25
/* Marker value used in new Zserv, in the byte location corresponding
* the command value in the old zserv header. To allow old and new
diff --git a/zebra/zserv.c b/zebra/zserv.c
index ca17c2c..89eb266 100644
--- a/zebra/zserv.c
+++ b/zebra/zserv.c
@@ -599,6 +599,89 @@
return zebra_server_send_message(client);
}
+/*
+ Modified version of zsend_ipv4_nexthop_lookup():
+ Query unicast rib if nexthop is not found on mrib.
+ Returns both route metric and protocol distance.
+*/
+static int
+zsend_ipv4_nexthop_lookup_mrib (struct zserv *client, struct in_addr addr)
+{
+ struct stream *s;
+ struct rib *rib;
+ unsigned long nump;
+ u_char num;
+ struct nexthop *nexthop;
+
+ /* Lookup nexthop. */
+ rib = rib_match_ipv4_safi (addr, SAFI_MULTICAST);
+
+ if (IS_ZEBRA_DEBUG_PACKET && IS_ZEBRA_DEBUG_RECV)
+ zlog_debug("%s: %s mrib entry found.", __func__, rib ? "Matching" : "No matching");
+
+ if (!rib) {
+ /* Retry lookup with unicast rib */
+ rib = rib_match_ipv4_safi (addr, SAFI_UNICAST);
+ if (IS_ZEBRA_DEBUG_PACKET && IS_ZEBRA_DEBUG_RECV)
+ zlog_debug("%s: %s rib entry found.", __func__, rib ? "Matching" : "No matching");
+ }
+
+ /* Get output stream. */
+ s = client->obuf;
+ stream_reset (s);
+
+ /* Fill in result. */
+ zserv_create_header (s, ZEBRA_IPV4_NEXTHOP_LOOKUP_MRIB);
+ stream_put_in_addr (s, &addr);
+
+ if (rib)
+ {
+ stream_putc (s, rib->distance);
+ stream_putl (s, rib->metric);
+ num = 0;
+ nump = stream_get_endp(s); /* remember position for nexthop_num */
+ stream_putc (s, 0); /* reserve room for nexthop_num */
+ /* Only non-recursive routes are elegible to resolve the nexthop we
+ * are looking up. Therefore, we will just iterate over the top
+ * chain of nexthops. */
+ for (nexthop = rib->nexthop; nexthop; nexthop = nexthop->next)
+ if (CHECK_FLAG (nexthop->flags, NEXTHOP_FLAG_FIB))
+ {
+ stream_putc (s, nexthop->type);
+ switch (nexthop->type)
+ {
+ case ZEBRA_NEXTHOP_IPV4:
+ stream_put_in_addr (s, &nexthop->gate.ipv4);
+ break;
+ case ZEBRA_NEXTHOP_IPV4_IFINDEX:
+ stream_put_in_addr (s, &nexthop->gate.ipv4);
+ stream_putl (s, nexthop->ifindex);
+ break;
+ case ZEBRA_NEXTHOP_IFINDEX:
+ case ZEBRA_NEXTHOP_IFNAME:
+ stream_putl (s, nexthop->ifindex);
+ break;
+ default:
+ /* do nothing */
+ break;
+ }
+ num++;
+ }
+
+ stream_putc_at (s, nump, num); /* store nexthop_num */
+ }
+ else
+ {
+ stream_putc (s, 0); /* distance */
+ stream_putl (s, 0); /* metric */
+ stream_putc (s, 0); /* nexthop_num */
+ }
+
+ stream_putw_at (s, 0, stream_get_endp (s));
+
+ return zebra_server_send_message(client);
+}
+
static int
zsend_ipv4_import_lookup (struct zserv *client, struct prefix_ipv4 *p)
{
@@ -920,6 +1003,16 @@
return zsend_ipv4_nexthop_lookup (client, addr);
}
+/* MRIB Nexthop lookup for IPv4. */
+static int
+zread_ipv4_nexthop_lookup_mrib (struct zserv *client, u_short length)
+{
+ struct in_addr addr;
+
+ addr.s_addr = stream_get_ipv4 (client->ibuf);
+ return zsend_ipv4_nexthop_lookup_mrib (client, addr);
+}
+
/* Nexthop lookup for IPv4. */
static int
zread_ipv4_import_lookup (struct zserv *client, u_short length)
@@ -1352,6 +1445,9 @@
case ZEBRA_IPV4_NEXTHOP_LOOKUP:
zread_ipv4_nexthop_lookup (client, length);
break;
+ case ZEBRA_IPV4_NEXTHOP_LOOKUP_MRIB:
+ zread_ipv4_nexthop_lookup_mrib (client, length);
+ break;
#ifdef HAVE_IPV6
case ZEBRA_IPV6_NEXTHOP_LOOKUP:
zread_ipv6_nexthop_lookup (client, length);