ip netns: Delete all netns

Allow delete all namespace names by:

    $ ip -all netns del
Signed-off-by: Vadim Kochan <vadim4j@gmail.com>

ip/ipnetns.c

@@ -23,7 +23,7 @@ static int usage(void)
 {
 	fprintf(stderr, "Usage: ip netns list\n");
 	fprintf(stderr, "       ip netns add NAME\n");
-	fprintf(stderr, "       ip netns delete NAME\n");
+	fprintf(stderr, "       ip [-all] netns delete [NAME]\n");
 	fprintf(stderr, "       ip netns identify [PID]\n");
 	fprintf(stderr, "       ip netns pids NAME\n");
 	fprintf(stderr, "       ip [-all] netns exec [NAME] cmd ...\n");
@@ -259,18 +259,11 @@ static int netns_identify(int argc, char **argv)
 
 }
 
-static int netns_delete(int argc, char **argv)
+static int on_netns_del(char *nsname, void *arg)
 {
-	const char *name;
 	char netns_path[MAXPATHLEN];
 
-	if (argc < 1) {
-		fprintf(stderr, "No netns name specified\n");
-		return -1;
-	}
-
-	name = argv[0];
-	snprintf(netns_path, sizeof(netns_path), "%s/%s", NETNS_RUN_DIR, name);
+	snprintf(netns_path, sizeof(netns_path), "%s/%s", NETNS_RUN_DIR, nsname);
 	umount2(netns_path, MNT_DETACH);
 	if (unlink(netns_path) < 0) {
 		fprintf(stderr, "Cannot remove namespace file \"%s\": %s\n",
@@ -280,6 +273,19 @@ static int netns_delete(int argc, char **argv)
 	return 0;
 }
 
+static int netns_delete(int argc, char **argv)
+{
+	if (argc < 1 && !do_all) {
+		fprintf(stderr, "No netns name specified\n");
+		return -1;
+	}
+
+	if (do_all)
+		return netns_foreach(on_netns_del, NULL);
+
+	return on_netns_del(argv[0], NULL);
+}
+
 static int create_netns_dir(void)
 {
 	/* Create the base netns directory if it doesn't exist */

man/man8/ip-netns.8

@@ -16,9 +16,13 @@ ip-netns \- process network namespace management
 .BR "ip netns" " { " list " } "
 
 .ti -8
-.BR "ip netns" " { " add " | " delete " } "
+.B ip netns add
 .I NETNSNAME
 
+.ti -8
+.B ip [-all] netns del
+.RI "[ " NETNSNAME " ]"
+
 .ti -8
 .BR "ip netns identify"
 .RI "[ " PID " ]"
@@ -76,7 +80,7 @@ If NAME is available in /var/run/netns/ this command creates a new
 network namespace and assigns NAME.
 
 .TP
-.B ip netns delete NAME - delete the name of a network namespace
+.B ip [-all] netns delete [ NAME ] - delete the name of a network namespace(s)
 .sp
 If NAME is present in /var/run/netns it is umounted and the mount
 point is removed.  If this is the last user of the network namespace the
@@ -84,6 +88,10 @@ network namespace will be freed, otherwise the network namespace
 persists until it has no more users.  ip netns delete may fail if
 the mount point is in use in another mount namespace.
 
+If
+.B -all
+option was specified then all the network namespace names will be removed.
+
 .TP
 .B ip netns identify [PID] - Report network namespaces names for process
 .sp