ospf6d: Json support added for command "show ipv6 ospf6 spf tree [json]"

Modify code to add JSON format output in show command
"show ipv6 ospf6 spf tree" with proper formating

Signed-off-by: Yash Ranjan <ranjany@vmware.com>

doc/user/ospf6d.rst

@@ -229,6 +229,15 @@ Showing OSPF6 information
    Interface name can also be given. JSON output can be obtained by appending
    'json' to the end of command.
 
+.. index:: show ipv6 ospf6 spf tree [json]
+.. clicmd:: show ipv6 ospf6 spf tree [json]
+
+   This commands shows the spf tree from the recent spf calculation with the
+   calling router as the root. If json is appended in the end, we can get the
+   tree in JSON format. Each area that the router belongs to has it's own
+   JSON object, with each router having "cost", "isLeafNode" and "children" as
+   arguments.
+   
 OSPF6 Configuration Examples
 ============================
 

ospf6d/ospf6_area.c

@@ -44,6 +44,7 @@
 #include "ospf6_abr.h"
 #include "ospf6_asbr.h"
 #include "ospf6d.h"
+#include "lib/json.h"
 
 DEFINE_MTYPE_STATIC(OSPF6D, OSPF6_PLISTNAME, "Prefix list name")
 
@@ -850,12 +851,13 @@ DEFUN (no_area_export_list,
 
 DEFUN (show_ipv6_ospf6_spf_tree,
        show_ipv6_ospf6_spf_tree_cmd,
-       "show ipv6 ospf6 spf tree",
+       "show ipv6 ospf6 spf tree [json]",
        SHOW_STR
        IP6_STR
        OSPF6_STR
        "Shortest Path First calculation\n"
-       "Show SPF tree\n")
+       "Show SPF tree\n"
+        JSON_STR)
 {
 	struct listnode *node;
 	struct ospf6_area *oa;
@@ -863,20 +865,52 @@ DEFUN (show_ipv6_ospf6_spf_tree,
 	struct ospf6_route *route;
 	struct prefix prefix;
 	struct ospf6 *ospf6;
+	json_object *json = NULL;
+	json_object *json_area = NULL;
+	json_object *json_head = NULL;
+	bool uj = use_json(argc, argv);
 
 	ospf6 = ospf6_lookup_by_vrf_name(VRF_DEFAULT_NAME);
 	OSPF6_CMD_CHECK_RUNNING(ospf6);
+
+	if (uj)
+		json = json_object_new_object();
 	ospf6_linkstate_prefix(ospf6->router_id, htonl(0), &prefix);
 
 	for (ALL_LIST_ELEMENTS_RO(ospf6->area_list, node, oa)) {
+		if (uj) {
+			json_area = json_object_new_object();
+			json_head = json_object_new_object();
+		}
 		route = ospf6_route_lookup(&prefix, oa->spf_table);
 		if (route == NULL) {
-			vty_out(vty, "LS entry for root not found in area %s\n",
-				oa->name);
+			if (uj) {
+				json_object_string_add(
+					json, oa->name,
+					"LS entry for not not found");
+				json_object_free(json_head);
+				json_object_free(json_area);
+			} else
+				vty_out(vty,
+					"LS entry for root not found in area %s\n",
+					oa->name);
 			continue;
 		}
 		root = (struct ospf6_vertex *)route->route_option;
-		ospf6_spf_display_subtree(vty, "", 0, root);
+		ospf6_spf_display_subtree(vty, "", 0, root, json_head, uj);
+
+		if (uj) {
+			json_object_object_add(json_area, root->name,
+					       json_head);
+			json_object_object_add(json, oa->name, json_area);
+		}
+	}
+
+	if (uj) {
+		vty_out(vty, "%s\n",
+			json_object_to_json_string_ext(
+				json, JSON_C_TO_STRING_PRETTY));
+		json_object_free(json);
 	}
 
 	return CMD_SUCCESS;
@@ -924,7 +958,7 @@ DEFUN (show_ipv6_ospf6_area_spf_tree,
 		return CMD_SUCCESS;
 	}
 	root = (struct ospf6_vertex *)route->route_option;
-	ospf6_spf_display_subtree(vty, "", 0, root);
+	ospf6_spf_display_subtree(vty, "", 0, root, NULL, false);
 
 	return CMD_SUCCESS;
 }
@@ -985,7 +1019,7 @@ DEFUN (show_ipv6_ospf6_simulate_spf_tree_root,
 		return CMD_SUCCESS;
 	}
 	root = (struct ospf6_vertex *)route->route_option;
-	ospf6_spf_display_subtree(vty, "", 0, root);
+	ospf6_spf_display_subtree(vty, "", 0, root, NULL, false);
 
 	ospf6_spf_table_finish(spf_table);
 	ospf6_route_table_delete(spf_table);

ospf6d/ospf6_spf.c

@@ -722,16 +722,24 @@ void ospf6_spf_schedule(struct ospf6 *ospf6, unsigned int reason)
 }
 
 void ospf6_spf_display_subtree(struct vty *vty, const char *prefix, int rest,
-			       struct ospf6_vertex *v)
+			       struct ospf6_vertex *v, json_object *json_obj,
+			       bool use_json)
 {
 	struct listnode *node, *nnode;
 	struct ospf6_vertex *c;
 	char *next_prefix;
 	int len;
 	int restnum;
+	json_object *json_childs = NULL;
+	json_object *json_child = NULL;
 
-	/* "prefix" is the space prefix of the display line */
-	vty_out(vty, "%s+-%s [%d]\n", prefix, v->name, v->cost);
+	if (use_json) {
+		json_childs = json_object_new_object();
+		json_object_int_add(json_obj, "cost", v->cost);
+	} else {
+		/* "prefix" is the space prefix of the display line */
+		vty_out(vty, "%s+-%s [%d]\n", prefix, v->name, v->cost);
+	}
 
 	len = strlen(prefix) + 4;
 	next_prefix = (char *)malloc(len);
@@ -743,10 +751,27 @@ void ospf6_spf_display_subtree(struct vty *vty, const char *prefix, int rest,
 
 	restnum = listcount(v->child_list);
 	for (ALL_LIST_ELEMENTS(v->child_list, node, nnode, c)) {
-		restnum--;
-		ospf6_spf_display_subtree(vty, next_prefix, restnum, c);
-	}
+		if (use_json)
+			json_child = json_object_new_object();
+		else
+			restnum--;
 
+		ospf6_spf_display_subtree(vty, next_prefix, restnum, c,
+					  json_child, use_json);
+
+		if (use_json)
+			json_object_object_add(json_childs, c->name,
+					       json_child);
+	}
+	if (use_json) {
+		json_object_boolean_add(json_obj, "isLeafNode",
+					!listcount(v->child_list));
+		if (listcount(v->child_list))
+			json_object_object_add(json_obj, "children",
+					       json_childs);
+		else
+			json_object_free(json_childs);
+	}
 	free(next_prefix);
 }
 

ospf6d/ospf6_spf.h

@@ -23,6 +23,7 @@
 
 #include "typesafe.h"
 #include "ospf6_top.h"
+#include "lib/json.h"
 
 /* Debug option */
 extern unsigned char conf_debug_ospf6_spf;
@@ -147,7 +148,8 @@ extern void ospf6_spf_calculation(uint32_t router_id,
 extern void ospf6_spf_schedule(struct ospf6 *ospf, unsigned int reason);
 
 extern void ospf6_spf_display_subtree(struct vty *vty, const char *prefix,
-				      int rest, struct ospf6_vertex *v);
+				      int rest, struct ospf6_vertex *v,
+				      json_object *json_obj, bool use_json);
 
 extern void ospf6_spf_config_write(struct vty *vty, struct ospf6 *ospf6);
 extern int config_write_ospf6_debug_spf(struct vty *vty);