tipc: JSON support for showing nametable

Add json output support for nametable show

Example output:
$tipc -j -p nametable show

[ {
        "type": 0,
        "lower": 16781313,
        "upper": 16781313,
        "scope": "zone",
        "port": 0,
        "node": ""
    },{
        "type": 0,
        "lower": 16781416,
        "upper": 16781416,
        "scope": "cluster",
        "port": 0,
        "node": ""
    } ]

v2:
    Replace variable 'json_flag' by 'json' declared in include/utils.h
    Add new parameter '-pretty' to support pretty output

v3:
    Update manual page

Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au>
Signed-off-by: David Ahern <dsahern@gmail.com>

man/man8/tipc-nametable.8

@@ -18,6 +18,16 @@ tipc-nametable \- show TIPC nametable
 Options (flags) that can be passed anywhere in the command chain.
 .TP
 .BR "\-h" , " --help"
+
+.TP
+.BR "\-j", " \-json"
+Output results in JavaScript Object Notation (JSON).
+
+.TP
+.BR "\-p", " \-pretty"
+The default JSON format is compact and more efficient to parse but hard for most users to read.
+This flag adds indentation for readability.
+
 Show help about last valid command. For example
 .B tipc nametable --help
 will show nametable help and

man/man8/tipc.8

@@ -40,6 +40,15 @@ will show bearer help and
 .B tipc --help
 will show general help. The position of the option in the string is irrelevant.
 
+.TP
+.BR "\-j", " \-json"
+Output results in JavaScript Object Notation (JSON).
+
+.TP
+.BR "\-p", " \-pretty"
+The default JSON format is compact and more efficient to parse but hard for most users to read.
+This flag adds indentation for readability.
+
 .SH COMMANDS
 
 .TP

tipc/nametable.c

@@ -21,6 +21,7 @@
 #include "msg.h"
 #include "nametable.h"
 #include "misc.h"
+#include "utils.h"
 
 #define PORTID_STR_LEN 45 /* Four u32 and five delimiter chars */
 
@@ -46,7 +47,7 @@ static int nametable_show_cb(const struct nlmsghdr *nlh, void *data)
 	if (!publ[TIPC_NLA_NAME_TABLE_PUBL])
 		return MNL_CB_ERROR;
 
-	if (!*iteration)
+	if (!*iteration && !is_json_context())
 		printf("%-10s %-10s %-10s %-8s %-10s %-33s\n",
 		       "Type", "Lower", "Upper", "Scope", "Port",
 		       "Node");
@@ -54,13 +55,20 @@ static int nametable_show_cb(const struct nlmsghdr *nlh, void *data)
 
 	hash2nodestr(mnl_attr_get_u32(publ[TIPC_NLA_PUBL_NODE]), str);
 
-	printf("%-10u %-10u %-10u %-8s %-10u %s\n",
+	open_json_object(NULL);
-	       mnl_attr_get_u32(publ[TIPC_NLA_PUBL_TYPE]),
+	print_uint(PRINT_ANY, "type", "%-10u",
-	       mnl_attr_get_u32(publ[TIPC_NLA_PUBL_LOWER]),
+			   mnl_attr_get_u32(publ[TIPC_NLA_PUBL_TYPE]));
-	       mnl_attr_get_u32(publ[TIPC_NLA_PUBL_UPPER]),
+	print_uint(PRINT_ANY, "lower", "%-10u",
-	       scope[mnl_attr_get_u32(publ[TIPC_NLA_PUBL_SCOPE])],
+			   mnl_attr_get_u32(publ[TIPC_NLA_PUBL_LOWER]));
-	       mnl_attr_get_u32(publ[TIPC_NLA_PUBL_REF]),
+	print_uint(PRINT_ANY, "upper", "%-10u",
-	       str);
+			   mnl_attr_get_u32(publ[TIPC_NLA_PUBL_UPPER]));
+	print_string(PRINT_ANY, "scope", "%-8s",
+			     scope[mnl_attr_get_u32(publ[TIPC_NLA_PUBL_SCOPE])]);
+	print_uint(PRINT_ANY, "port", "%-10u",
+			   mnl_attr_get_u32(publ[TIPC_NLA_PUBL_REF]));
+	print_string(PRINT_ANY, "node", "%s", str);
+	print_string(PRINT_FP, NULL, "\n", "");
+	close_json_object();
 
 	return MNL_CB_OK;
 }
@@ -70,6 +78,7 @@ static int cmd_nametable_show(struct nlmsghdr *nlh, const struct cmd *cmd,
 {
 	int iteration = 0;
 	char buf[MNL_SOCKET_BUFFER_SIZE];
+	int rc = 0;
 
 	if (help_flag) {
 		fprintf(stderr, "Usage: %s nametable show\n", cmdl->argv[0]);
@@ -81,7 +90,11 @@ static int cmd_nametable_show(struct nlmsghdr *nlh, const struct cmd *cmd,
 		return -1;
 	}
 
-	return msg_dumpit(nlh, nametable_show_cb, &iteration);
+	new_json_obj(json);
+	rc = msg_dumpit(nlh, nametable_show_cb, &iteration);
+	delete_json_obj();
+
+	return rc;
 }
 
 void cmd_nametable_help(struct cmdl *cmdl)

tipc/tipc.c

@@ -24,6 +24,8 @@
 #include "cmdl.h"
 
 int help_flag;
+int json;
+int pretty;
 
 static void about(struct cmdl *cmdl)
 {
@@ -33,6 +35,8 @@ static void about(struct cmdl *cmdl)
 		"\n"
 		"Options:\n"
 		" -h, --help \t\tPrint help for last given command\n"
+		" -j, --json \t\tJson format printouts\n"
+		" -p, --pretty \t\tpretty print\n"
 		"\n"
 		"Commands:\n"
 		" bearer                - Show or modify bearers\n"
@@ -53,6 +57,8 @@ int main(int argc, char *argv[])
 	const struct cmd cmd = {"tipc", NULL, about};
 	struct option long_options[] = {
 		{"help", no_argument, 0, 'h'},
+		{"json", no_argument, 0, 'j'},
+		{"pretty", no_argument, 0, 'p'},
 		{0, 0, 0, 0}
 	};
 	const struct cmd cmds[] = {
@@ -69,7 +75,7 @@ int main(int argc, char *argv[])
 	do {
 		int option_index = 0;
 
-		i = getopt_long(argc, argv, "h", long_options, &option_index);
+		i = getopt_long(argc, argv, "hjp", long_options, &option_index);
 
 		switch (i) {
 		case 'h':
@@ -79,6 +85,18 @@ int main(int argc, char *argv[])
 			 */
 			help_flag = 1;
 			break;
+		case 'j':
+			/*
+			 * Enable json format printouts
+			 */
+			json = 1;
+			break;
+		case 'p':
+			/*
+			 * Enable json pretty output
+			 */
+			pretty = 1;
+			break;
 		case -1:
 			/* End of options */
 			break;