zebra: add dplane backup nhg api

Add an api to allow a dplane plugin to set a route's backup
nexthops.

Signed-off-by: Mark Stapp <mjs@voltanet.io>

2 files changed, 33 insertions, 0 deletions

diff --git a/zebra/zebra_dplane.c b/zebra/zebra_dplane.c
index 64383fc81c..7e7bf1410c 100644
--- a/zebra/zebra_dplane.c
+++ b/zebra/zebra_dplane.c
@@ -1149,6 +1149,37 @@ void dplane_ctx_set_nexthops(struct zebra_dplane_ctx *ctx, struct nexthop *nh)
 	nexthop_group_copy_nh_sorted(&(ctx->u.rinfo.zd_ng), nh);
 }
 
+/*
+ * Set the list of backup nexthops; their ordering is preserved (they're not
+ * re-sorted.)
+ */
+void dplane_ctx_set_backup_nhg(struct zebra_dplane_ctx *ctx,
+			       const struct nexthop_group *nhg)
+{
+	struct nexthop *nh, *last_nh, *nexthop;
+
+	DPLANE_CTX_VALID(ctx);
+
+	if (ctx->u.rinfo.backup_ng.nexthop) {
+		nexthops_free(ctx->u.rinfo.backup_ng.nexthop);
+		ctx->u.rinfo.backup_ng.nexthop = NULL;
+	}
+
+	last_nh = NULL;
+
+	/* Be careful to preserve the order of the backup list */
+	for (nh = nhg->nexthop; nh; nh = nh->next) {
+		nexthop = nexthop_dup(nh, NULL);
+
+		if (last_nh)
+			NEXTHOP_APPEND(last_nh, nexthop);
+		else
+			ctx->u.rinfo.backup_ng.nexthop = nexthop;
+
+		last_nh = nexthop;
+	}
+}
+
 uint32_t dplane_ctx_get_nhg_id(const struct zebra_dplane_ctx *ctx)
 {
 	DPLANE_CTX_VALID(ctx);
diff --git a/zebra/zebra_dplane.h b/zebra/zebra_dplane.h
index 9e07231fea..2c3501a5b1 100644
--- a/zebra/zebra_dplane.h
+++ b/zebra/zebra_dplane.h
@@ -283,6 +283,8 @@ void dplane_ctx_set_distance(struct zebra_dplane_ctx *ctx, uint8_t distance);
 uint8_t dplane_ctx_get_old_distance(const struct zebra_dplane_ctx *ctx);
 
 void dplane_ctx_set_nexthops(struct zebra_dplane_ctx *ctx, struct nexthop *nh);
+void dplane_ctx_set_backup_nhg(struct zebra_dplane_ctx *ctx,
+			       const struct nexthop_group *nhg);
 
 uint32_t dplane_ctx_get_nhg_id(const struct zebra_dplane_ctx *ctx);
 const struct nexthop_group *dplane_ctx_get_ng(