lib: Allow doing match/set tag untagged

In route-map: `match tag untagged`.

E.g. Cisco/Juniper allows that, but they use `match tag 0` instead.

Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>

4 files changed, 39 insertions, 18 deletions

diff --git a/doc/user/ripngd.rst b/doc/user/ripngd.rst
index f898bed57..f55ee3944 100644
--- a/doc/user/ripngd.rst
+++ b/doc/user/ripngd.rst
@@ -136,7 +136,7 @@ functionality.
    range is very large for compatibility with other protocols. For RIPng, valid
    metric values are from 1 to 16.
 
-.. clicmd:: set tag (1-4294967295)
+.. clicmd:: set tag <untagged|(1-4294967295)>
 
    Set a tag on the matched route.
 
diff --git a/doc/user/routemap.rst b/doc/user/routemap.rst
index 791762aa7..1d2f4e352 100644
--- a/doc/user/routemap.rst
+++ b/doc/user/routemap.rst
@@ -176,10 +176,9 @@ Route Map Match Command
 
    Matches the specified `metric`.
 
-.. clicmd:: match tag TAG
+.. clicmd:: match tag <untagged|(1-4294967295)>
 
-   Matches the specified tag value associated with the route. This tag value
-   can be in the range of (1-4294967295).
+   Matches the specified tag (or untagged) value associated with the route.
 
 .. clicmd:: match local-preference METRIC
 
@@ -241,9 +240,10 @@ Route Map Set Command
 
 .. program:: configure
 
-.. clicmd:: set tag TAG
+.. clicmd:: set tag <untagged|(1-4294967295)>
+
+   Set a tag on the matched route.
 
-   Set a tag on the matched route. This tag value can be from (1-4294967295).
    Additionally if you have compiled with the :option:`--enable-realms`
    configure option. Tag values from (1-255) are sent to the Linux kernel as a
    realm value. Then route policy can be applied. See the tc man page.  As
diff --git a/lib/routemap_cli.c b/lib/routemap_cli.c
index a12a07c14..8e2e497e0 100644
--- a/lib/routemap_cli.c
+++ b/lib/routemap_cli.c
@@ -490,29 +490,33 @@ DEFPY_YANG(
 
 DEFPY_YANG(
 	match_tag, match_tag_cmd,
-	"match tag (1-4294967295)$tag",
+	"match tag <untagged$untagged|(1-4294967295)$tagged>",
 	MATCH_STR
 	"Match tag of route\n"
+	"Untagged route\n"
 	"Tag value\n")
 {
 	const char *xpath =
 		"./match-condition[condition='frr-route-map:match-tag']";
 	char xpath_value[XPATH_MAXLEN];
+	char value[64];
 
 	nb_cli_enqueue_change(vty, xpath, NB_OP_CREATE, NULL);
 	snprintf(xpath_value, sizeof(xpath_value),
 		 "%s/rmap-match-condition/tag", xpath);
-	nb_cli_enqueue_change(vty, xpath_value, NB_OP_MODIFY, tag_str);
+	snprintf(value, sizeof(value), "%lu", tagged ? tagged : 0);
+	nb_cli_enqueue_change(vty, xpath_value, NB_OP_MODIFY, value);
 
 	return nb_cli_apply_changes(vty, NULL);
 }
 
 DEFPY_YANG(
 	no_match_tag, no_match_tag_cmd,
-	"no match tag [(1-4294967295)]",
+	"no match tag [<untagged|(1-4294967295)>]",
 	NO_STR
 	MATCH_STR
 	"Match tag of route\n"
+	"Untagged route\n"
 	"Tag value\n")
 {
 	const char *xpath =
@@ -581,9 +585,15 @@ void route_map_condition_show(struct vty *vty, const struct lyd_node *dnode,
 			yang_dnode_get_string(dnode,
 					      "./rmap-match-condition/metric"));
 	} else if (IS_MATCH_TAG(condition)) {
-		vty_out(vty, " match tag %s\n",
-			yang_dnode_get_string(dnode,
-					      "./rmap-match-condition/tag"));
+		uint32_t tag =
+			strtoul(yang_dnode_get_string(dnode,
+						      "./rmap-match-condition/tag"),
+				NULL, 10);
+
+		if (!tag)
+			vty_out(vty, " match tag untagged\n");
+		else
+			vty_out(vty, " match tag %u\n", tag);
 	} else if (IS_MATCH_IPv4_PREFIX_LEN(condition)) {
 		vty_out(vty, " match ip address prefix-len %s\n",
 			yang_dnode_get_string(
@@ -973,28 +983,32 @@ DEFPY_YANG(no_set_max_metric, no_set_max_metric_cmd,
 
 DEFPY_YANG(
 	set_tag, set_tag_cmd,
-	"set tag (1-4294967295)$tag",
+	"set tag <untagged$untagged|(1-4294967295)$tagged>",
 	SET_STR
 	"Tag value for routing protocol\n"
+	"Untagged route\n"
 	"Tag value\n")
 {
 	const char *xpath = "./set-action[action='frr-route-map:set-tag']";
 	char xpath_value[XPATH_MAXLEN];
+	char value[64];
 
 	nb_cli_enqueue_change(vty, xpath, NB_OP_CREATE, NULL);
 	snprintf(xpath_value, sizeof(xpath_value), "%s/rmap-set-action/tag",
 		 xpath);
-	nb_cli_enqueue_change(vty, xpath_value, NB_OP_MODIFY, tag_str);
+	snprintf(value, sizeof(value), "%lu", tagged ? tagged : 0);
+	nb_cli_enqueue_change(vty, xpath_value, NB_OP_MODIFY, value);
 
 	return nb_cli_apply_changes(vty, NULL);
 }
 
 DEFPY_YANG(
 	no_set_tag, no_set_tag_cmd,
-	"no set tag [(1-4294967295)]",
+	"no set tag [<untagged|(1-4294967295)>]",
 	NO_STR
 	SET_STR
 	"Tag value for routing protocol\n"
+	"Untagged route\n"
 	"Tag value\n")
 {
 	const char *xpath = "./set-action[action='frr-route-map:set-tag']";
@@ -1101,8 +1115,15 @@ void route_map_action_show(struct vty *vty, const struct lyd_node *dnode,
 			yang_dnode_get_string(dnode,
 					      "./rmap-set-action/max-metric"));
 	} else if (IS_SET_TAG(action)) {
-		vty_out(vty, " set tag %s\n",
-			yang_dnode_get_string(dnode, "rmap-set-action/tag"));
+		uint32_t tag =
+			strtoul(yang_dnode_get_string(dnode,
+						      "rmap-set-action/tag"),
+				NULL, 10);
+
+		if (!tag)
+			vty_out(vty, " set tag untagged\n");
+		else
+			vty_out(vty, " set tag %u\n", tag);
 	} else if (IS_SET_SR_TE_COLOR(action)) {
 		vty_out(vty, " set sr-te color %s\n",
 			yang_dnode_get_string(dnode,
diff --git a/yang/frr-route-map.yang b/yang/frr-route-map.yang
index 7cb13b60f..26d56acc0 100644
--- a/yang/frr-route-map.yang
+++ b/yang/frr-route-map.yang
@@ -268,7 +268,7 @@ module frr-route-map {
           when "derived-from-or-self(../condition, 'match-tag')";
           leaf tag {
             type uint32 {
-              range "1..4294967295";
+              range "0..4294967295";
             }
           }
         }