bgpd, lib, pimd: Make nexthop_update decoding common

Create a zapi_nexthop_update_decode function that both
pim and bgp use to decode the message from zebra.

There probably could be further optimizations but I opted
to keep the code as similiar as is possible between the
originals because they both make some assumptions about
code flow that I do not fully understand yet.

The real goal here is that I want to create a new
user of the nexthop tracking code from a higher level
daemon and I see no need to re-implement this damn
code again for a 3rd time.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

1 files changed, 66 insertions, 0 deletions

diff --git a/lib/zclient.c b/lib/zclient.c
index d3717d0cdd..cba9640f15 100644
--- a/lib/zclient.c
+++ b/lib/zclient.c
@@ -1212,6 +1212,72 @@ stream_failure:
 	return false;
 }
 
+struct nexthop *nexthop_from_zapi_nexthop(struct zapi_nexthop *znh)
+{
+	struct nexthop *n = nexthop_new();
+
+	n->type = znh->type;
+	n->ifindex = znh->ifindex;
+	n->gate = znh->gate;
+
+	/*
+	 * This function does not currently handle labels
+	 */
+
+	return n;
+}
+
+bool zapi_nexthop_update_decode(struct stream *s, struct zapi_route *nhr)
+{
+	uint32_t i;
+
+	memset(nhr, 0, sizeof(*nhr));
+
+	STREAM_GETW(s, nhr->prefix.family);
+	STREAM_GETC(s, nhr->prefix.prefixlen);
+	switch(nhr->prefix.family) {
+	case AF_INET:
+		STREAM_GET(&nhr->prefix.u.prefix4.s_addr, s, IPV4_MAX_BYTELEN);
+		break;
+	case AF_INET6:
+		STREAM_GET(&nhr->prefix.u.prefix6, s, IPV6_MAX_BYTELEN);
+		break;
+	default:
+		break;
+	}
+
+	STREAM_GETC(s, nhr->distance);
+	STREAM_GETL(s, nhr->metric);
+	STREAM_GETC(s, nhr->nexthop_num);
+
+	for (i = 0; i < nhr->nexthop_num ; i++) {
+		STREAM_GETC(s, nhr->nexthops[i].type);
+		switch (nhr->nexthops[i].type) {
+		case NEXTHOP_TYPE_IPV4:
+		case NEXTHOP_TYPE_IPV4_IFINDEX:
+			STREAM_GET(&nhr->nexthops[i].gate.ipv4.s_addr,
+				   s, IPV4_MAX_BYTELEN);
+			STREAM_GETL(s, nhr->nexthops[i].ifindex);
+			break;
+		case NEXTHOP_TYPE_IFINDEX:
+			STREAM_GETL(s, nhr->nexthops[i].ifindex);
+			break;
+		case NEXTHOP_TYPE_IPV6:
+		case NEXTHOP_TYPE_IPV6_IFINDEX:
+			STREAM_GET(&nhr->nexthops[i].gate.ipv6,
+				   s, IPV6_MAX_BYTELEN);
+			STREAM_GETL(s, nhr->nexthops[i].ifindex);
+			break;
+		case NEXTHOP_TYPE_BLACKHOLE:
+			break;
+		}
+	}
+
+	return true;
+stream_failure:
+	return false;
+}
+
 /*
  * send a ZEBRA_REDISTRIBUTE_ADD or ZEBRA_REDISTRIBUTE_DELETE
  * for the route type (ZEBRA_ROUTE_KERNEL etc.). The zebra server will