[iproute2,net-next] bridge: this patch adds json support for bridge mdb show

diff --git a/bridge/mdb.c b/bridge/mdb.c
index e60ff3e..748091b 100644
--- a/bridge/mdb.c
+++ b/bridge/mdb.c
@@ -13,6 +13,7 @@ 
 #include <linux/if_ether.h>
 #include <string.h>
 #include <arpa/inet.h>
+#include <json_writer.h>
 
 #include "libnetlink.h"
 #include "br_common.h"
@@ -25,6 +26,9 @@ 
 #endif
 
 static unsigned int filter_index, filter_vlan;
+json_writer_t *jw_global;
+static bool print_mdb_entries = true;
+static bool print_mdb_router = true;
 
 static void usage(void)
 {
@@ -49,13 +53,26 @@  static void __print_router_port_stats(FILE *f, struct rtattr *pattr)
 	if (tb[MDBA_ROUTER_PATTR_TIMER]) {
 		__jiffies_to_tv(&tv,
 				rta_getattr_u32(tb[MDBA_ROUTER_PATTR_TIMER]));
-		fprintf(f, " %4i.%.2i",
-			(int)tv.tv_sec, (int)tv.tv_usec/10000);
+		if (jw_global) {
+			char formatted_time[9];
+
+			snprintf(formatted_time, sizeof(formatted_time),
+				 "%4i.%.2i", (int)tv.tv_sec,
+				 (int)tv.tv_usec/10000);
+			jsonw_string_field(jw_global, "timer", formatted_time);
+		} else {
+			fprintf(f, " %4i.%.2i",
+				(int)tv.tv_sec, (int)tv.tv_usec/10000);
+		}
 	}
 	if (tb[MDBA_ROUTER_PATTR_TYPE]) {
 		type = rta_getattr_u8(tb[MDBA_ROUTER_PATTR_TYPE]);
-		fprintf(f, " %s",
-			is_temp_mcast_rtr(type) ? "temp" : "permanent");
+		if (jw_global)
+			jsonw_string_field(jw_global, "type",
+				is_temp_mcast_rtr(type) ? "temp" : "permanent");
+		else
+			fprintf(f, " %s",
+				is_temp_mcast_rtr(type) ? "temp" : "permanent");
 	}
 }
 
@@ -65,24 +82,50 @@  static void br_print_router_ports(FILE *f, struct rtattr *attr, __u32 brifidx)
 	struct rtattr *i;
 	int rem;
 
-	if (!show_stats)
-		fprintf(f, "router ports on %s: ", ll_index_to_name(brifidx));
-
 	rem = RTA_PAYLOAD(attr);
-	for (i = RTA_DATA(attr); RTA_OK(i, rem); i = RTA_NEXT(i, rem)) {
-		port_ifindex = RTA_DATA(i);
-		if (show_stats) {
-			fprintf(f, "router ports on %s: %s",
-				ll_index_to_name(brifidx),
-				ll_index_to_name(*port_ifindex));
-			__print_router_port_stats(f, i);
-			fprintf(f, "\n");
-		} else {
-			fprintf(f, "%s ", ll_index_to_name(*port_ifindex));
+	if (jw_global) {
+		jsonw_name(jw_global, ll_index_to_name(brifidx));
+		jsonw_start_array(jw_global);
+		for (i = RTA_DATA(attr); RTA_OK(i, rem); i = RTA_NEXT(i, rem)) {
+			port_ifindex = RTA_DATA(i);
+			jsonw_start_object(jw_global);
+			jsonw_string_field(jw_global,
+					   "port",
+					   ll_index_to_name(*port_ifindex));
+			if (show_stats)
+				__print_router_port_stats(f, i);
+			jsonw_end_object(jw_global);
+		}
+		jsonw_end_array(jw_global);
+	} else {
+		if (!show_stats)
+			fprintf(f, "router ports on %s: ",
+				ll_index_to_name(brifidx));
+		for (i = RTA_DATA(attr); RTA_OK(i, rem); i = RTA_NEXT(i, rem)) {
+			port_ifindex = RTA_DATA(i);
+			if (show_stats) {
+				fprintf(f, "router ports on %s: %s",
+					ll_index_to_name(brifidx),
+					ll_index_to_name(*port_ifindex));
+				__print_router_port_stats(f, i);
+				fprintf(f, "\n");
+			} else{
+				fprintf(f, "%s ",
+					ll_index_to_name(*port_ifindex));
+			}
 		}
+		if (!show_stats)
+			fprintf(f, "\n");
 	}
-	if (!show_stats)
-		fprintf(f, "\n");
+}
+
+static void start_json_mdb_flags_array(bool *mdb_flags)
+{
+	if (*mdb_flags)
+		return;
+	jsonw_name(jw_global, "flags");
+	jsonw_start_array(jw_global);
+	*mdb_flags = true;
 }
 
 static void print_mdb_entry(FILE *f, int ifindex, struct br_mdb_entry *e,
@@ -91,28 +134,70 @@  static void print_mdb_entry(FILE *f, int ifindex, struct br_mdb_entry *e,
 	SPRINT_BUF(abuf);
 	const void *src;
 	int af;
+	bool mdb_flags = false;
 
 	if (filter_vlan && e->vid != filter_vlan)
 		return;
 	af = e->addr.proto == htons(ETH_P_IP) ? AF_INET : AF_INET6;
 	src = af == AF_INET ? (const void *)&e->addr.u.ip4 :
 			      (const void *)&e->addr.u.ip6;
-	if (n->nlmsg_type == RTM_DELMDB)
-		fprintf(f, "Deleted ");
-	fprintf(f, "dev %s port %s grp %s %s %s", ll_index_to_name(ifindex),
-		ll_index_to_name(e->ifindex),
-		inet_ntop(af, src, abuf, sizeof(abuf)),
-		(e->state & MDB_PERMANENT) ? "permanent" : "temp",
-		(e->flags & MDB_FLAGS_OFFLOAD) ? "offload" : "");
-	if (e->vid)
-		fprintf(f, " vid %hu", e->vid);
+	if (jw_global)
+		jsonw_start_object(jw_global);
+	if (n->nlmsg_type == RTM_DELMDB) {
+		if (jw_global)
+			jsonw_string_field(jw_global, "opCode", "deleted");
+		else
+			fprintf(f, "Deleted ");
+	}
+	if (jw_global) {
+		jsonw_string_field(jw_global, "dev", ll_index_to_name(ifindex));
+		jsonw_string_field(jw_global,
+				   "port",
+				   ll_index_to_name(e->ifindex));
+		jsonw_string_field(jw_global, "grp", inet_ntop(af, src,
+			abuf, sizeof(abuf)));
+		jsonw_string_field(jw_global, "state",
+			(e->state & MDB_PERMANENT) ? "permanent" : "temp");
+		if (e->flags & MDB_FLAGS_OFFLOAD) {
+			start_json_mdb_flags_array(&mdb_flags);
+			jsonw_string(jw_global, "offload");
+		}
+		if (mdb_flags)
+			jsonw_end_array(jw_global);
+	} else{
+		fprintf(f, "dev %s port %s grp %s %s %s",
+			ll_index_to_name(ifindex),
+			ll_index_to_name(e->ifindex),
+			inet_ntop(af, src, abuf, sizeof(abuf)),
+			(e->state & MDB_PERMANENT) ? "permanent" : "temp",
+			(e->flags & MDB_FLAGS_OFFLOAD) ? "offload" : "");
+	}
+	if (e->vid) {
+		if (jw_global)
+			jsonw_uint_field(jw_global, "vid", e->vid);
+		else
+			fprintf(f, " vid %hu", e->vid);
+	}
 	if (show_stats && tb && tb[MDBA_MDB_EATTR_TIMER]) {
 		struct timeval tv;
 
 		__jiffies_to_tv(&tv, rta_getattr_u32(tb[MDBA_MDB_EATTR_TIMER]));
-		fprintf(f, "%4i.%.2i", (int)tv.tv_sec, (int)tv.tv_usec/10000);
+		if (jw_global) {
+			char formatted_time[9];
+
+			snprintf(formatted_time, sizeof(formatted_time),
+				 "%4i.%.2i", (int)tv.tv_sec,
+				 (int)tv.tv_usec/10000);
+			jsonw_string_field(jw_global, "timer", formatted_time);
+		} else {
+			fprintf(f, "%4i.%.2i", (int)tv.tv_sec,
+				(int)tv.tv_usec/10000);
+		}
 	}
-	fprintf(f, "\n");
+	if (jw_global)
+		jsonw_end_object(jw_global);
+	else
+		fprintf(f, "\n");
 }
 
 static void br_print_mdb_entry(FILE *f, int ifindex, struct rtattr *attr,
@@ -157,14 +242,14 @@  int print_mdb(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
 
 	parse_rtattr(tb, MDBA_MAX, MDBA_RTA(r), n->nlmsg_len - NLMSG_LENGTH(sizeof(*r)));
 
-	if (tb[MDBA_MDB]) {
+	if (tb[MDBA_MDB] && print_mdb_entries) {
 		int rem = RTA_PAYLOAD(tb[MDBA_MDB]);
 
 		for (i = RTA_DATA(tb[MDBA_MDB]); RTA_OK(i, rem); i = RTA_NEXT(i, rem))
 			br_print_mdb_entry(fp, r->ifindex, i, n);
 	}
 
-	if (tb[MDBA_ROUTER]) {
+	if (tb[MDBA_ROUTER] && print_mdb_router) {
 		if (n->nlmsg_type == RTM_GETMDB) {
 			if (show_details)
 				br_print_router_ports(fp, tb[MDBA_ROUTER],
@@ -174,15 +259,33 @@  int print_mdb(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
 
 			i = RTA_DATA(tb[MDBA_ROUTER]);
 			port_ifindex = RTA_DATA(i);
-			if (n->nlmsg_type == RTM_DELMDB)
-				fprintf(fp, "Deleted ");
-			fprintf(fp, "router port dev %s master %s\n",
-				ll_index_to_name(*port_ifindex),
-				ll_index_to_name(r->ifindex));
+			if (n->nlmsg_type == RTM_DELMDB) {
+				if (jw_global)
+					jsonw_string_field(jw_global,
+							   "opCode",
+							   "deleted");
+				else
+					fprintf(fp, "Deleted ");
+			}
+			if (jw_global) {
+				jsonw_name(jw_global,
+					   ll_index_to_name(r->ifindex));
+				jsonw_start_array(jw_global);
+				jsonw_start_object(jw_global);
+				jsonw_string_field(jw_global, "port",
+					ll_index_to_name(*port_ifindex));
+				jsonw_end_object(jw_global);
+				jsonw_end_array(jw_global);
+			} else {
+				fprintf(fp, "router port dev %s master %s\n",
+					ll_index_to_name(*port_ifindex),
+					ll_index_to_name(r->ifindex));
+			}
 		}
 	}
 
-	fflush(fp);
+	if (!jw_global)
+		fflush(fp);
 
 	return 0;
 }
@@ -215,15 +318,54 @@  static int mdb_show(int argc, char **argv)
 		}
 	}
 
+	/* get mdb entries*/
+	if (rtnl_wilddump_request(&rth, PF_BRIDGE, RTM_GETMDB) < 0) {
+		perror("Cannot send dump request");
+		return -1;
+	}
+
+	if (!json_output) {
+		/* Normal output */
+		if (rtnl_dump_filter(&rth, print_mdb, stdout) < 0) {
+			fprintf(stderr, "Dump terminated\n");
+			return -1;
+		}
+		return 0;
+	}
+	/* Json output */
+	jw_global = jsonw_new(stdout);
+	jsonw_pretty(jw_global, 1);
+	jsonw_start_object(jw_global);
+	jsonw_name(jw_global, "mdb");
+	jsonw_start_array(jw_global);
+
+	/* print mdb entries */
+	print_mdb_entries = true;
+	print_mdb_router = false;
+	if (rtnl_dump_filter(&rth, print_mdb, stdout) < 0) {
+		fprintf(stderr, "Dump terminated\n");
+		return -1;
+	}
+	jsonw_end_array(jw_global);
+
+	/* get router ports */
 	if (rtnl_wilddump_request(&rth, PF_BRIDGE, RTM_GETMDB) < 0) {
 		perror("Cannot send dump request");
 		return -1;
 	}
+	jsonw_name(jw_global, "router");
+	jsonw_start_object(jw_global);
 
+	/* print router ports */
+	print_mdb_entries = false;
+	print_mdb_router = true;
 	if (rtnl_dump_filter(&rth, print_mdb, stdout) < 0) {
 		fprintf(stderr, "Dump terminated\n");
 		return -1;
 	}
+	jsonw_end_object(jw_global);
+	jsonw_end_object(jw_global);
+	jsonw_destroy(&jw_global);
 
 	return 0;
 }