Merge pull request #5901 from mjstapp/backup_nh_prep

zebra, lib: Backup nexthop (path) prep work

1 files changed, 20 insertions, 2 deletions

diff --git a/lib/nexthop.h b/lib/nexthop.h
index 267f9f28ad..c4e88dd844 100644
--- a/lib/nexthop.h
+++ b/lib/nexthop.h
@@ -86,6 +86,8 @@ struct nexthop {
 					  * active one
 					  */
 #define NEXTHOP_FLAG_RNH_FILTERED  (1 << 5) /* rmap filtered, used by rnh */
+#define NEXTHOP_FLAG_HAS_BACKUP (1 << 6)    /* Backup nexthop index is set */
+
 #define NEXTHOP_IS_ACTIVE(flags)                                               \
 	(CHECK_FLAG(flags, NEXTHOP_FLAG_ACTIVE)                                \
 	 && !CHECK_FLAG(flags, NEXTHOP_FLAG_DUPLICATE))
@@ -116,15 +118,31 @@ struct nexthop {
 
 	/* Weight of the nexthop ( for unequal cost ECMP ) */
 	uint8_t weight;
+
+	/* Index of a corresponding backup nexthop in a backup list;
+	 * only meaningful if the HAS_BACKUP flag is set.
+	 */
+	uint8_t backup_idx;
 };
 
+/* Backup index value is limited */
+#define NEXTHOP_BACKUP_IDX_MAX 255
+
+/* Utility to append one nexthop to another. */
+#define NEXTHOP_APPEND(to, new)           \
+	do {                              \
+		(to)->next = (new);       \
+		(new)->prev = (to);       \
+		(new)->next = NULL;       \
+	} while (0)
+
 struct nexthop *nexthop_new(void);
 
 void nexthop_free(struct nexthop *nexthop);
 void nexthops_free(struct nexthop *nexthop);
 
-void nexthop_add_labels(struct nexthop *, enum lsp_types_t, uint8_t,
-			mpls_label_t *);
+void nexthop_add_labels(struct nexthop *nexthop, enum lsp_types_t ltype,
+			uint8_t num_labels, const mpls_label_t *labels);
 void nexthop_del_labels(struct nexthop *);
 
 /*