lib: add SAFI_ENCAP type, safi2str prefix utility

Signed-off-by: Lou Berger <lberger@labn.net>
diff --git a/lib/prefix.c b/lib/prefix.c
index 936e9fc..3e4ca16 100644
--- a/lib/prefix.c
+++ b/lib/prefix.c
@@ -223,6 +223,22 @@
   return 0;
 }
 
+const char *
+safi2str(safi_t safi)
+{
+  switch (safi) {
+    case SAFI_UNICAST:
+	return "unicast";
+    case SAFI_MULTICAST:
+	return "multicast";
+    case SAFI_ENCAP:
+	return "encap";
+    case SAFI_MPLS_VPN:
+	return "vpn";
+  }
+  return NULL;
+}
+
 /* If n includes p prefix then return 1 else return 0. */
 int
 prefix_match (const struct prefix *n, const struct prefix *p)
diff --git a/lib/prefix.h b/lib/prefix.h
index a517d79..4a31750 100644
--- a/lib/prefix.h
+++ b/lib/prefix.h
@@ -173,6 +173,7 @@
 extern int str2family(const char *);
 extern int afi2family (afi_t);
 extern afi_t family2afi (int);
+extern const char *safi2str(safi_t safi);
 
 /* Check bit of the prefix. */
 extern unsigned int prefix_bit (const u_char *prefix, const u_char prefixlen);
diff --git a/lib/zebra.h b/lib/zebra.h
index 5f45a3a..644729b 100644
--- a/lib/zebra.h
+++ b/lib/zebra.h
@@ -489,7 +489,8 @@
 #define SAFI_MULTICAST            2
 #define SAFI_RESERVED_3           3
 #define SAFI_MPLS_VPN             4
-#define SAFI_MAX                  5
+#define SAFI_ENCAP		  7 /* per IANA */
+#define SAFI_MAX                  8
 
 /* Default Administrative Distance of each protocol. */
 #define ZEBRA_KERNEL_DISTANCE_DEFAULT      0