MINOR: listeners: Add support for a label on bind line

It is now possile to set a label on a bind line. All sockets attached to
this bind line inherits from this label. The idea is to be able to groud of
sockets. For now, there is no mechanism to create these groups, this must be
done by hand.

doc/configuration.txt

@@ -16698,6 +16698,10 @@ interface <interface>
   client IP addresses need to be able to reach frontends hosted on different
   interfaces.
 
+label <label>
+  Sets an optional label for these sockets. It could be used group sockets by
+  label, independently of where the bind lines were declared.
+
 level <level>
   This setting is used with the stats sockets only to restrict the nature of
   the commands that can be issued on the socket. It is ignored by other

include/haproxy/listener-t.h

@@ -244,7 +244,7 @@ struct listener {
 	struct fe_counters *counters;	/* statistics counters */
 	struct mt_list wait_queue;	/* link element to make the listener wait for something (LI_LIMITED)  */
 	char *name;			/* listener's name */
-
+	char *label;                    /* listener's label */
 	unsigned int thr_conn[MAX_THREADS_PER_GROUP]; /* number of connections per thread for the group */
 
 	struct list by_fe;              /* chaining in frontend's list of listeners */

src/listener.c

@@ -932,6 +932,11 @@ struct listener *clone_listener(struct listener *src)
 		if (!l->name)
 			goto oom2;
 	}
+	if (l->label) {
+		l->label = strdup(l->label);
+		if (!l->label)
+			goto oom3;
+	}
 
 	l->rx.owner = l;
 	l->rx.shard_info = NULL;
@@ -952,6 +957,8 @@ struct listener *clone_listener(struct listener *src)
 	global.maxsock++;
 	return l;
 
+ oom3:
+	free(l->name);
  oom2:
 	free(l);
  oom1:
@@ -2422,6 +2429,28 @@ static int bind_parse_name(char **args, int cur_arg, struct proxy *px, struct bi
 	return 0;
 }
 
+/* parse the "label" bind keyword */
+static int bind_parse_label(char **args, int cur_arg, struct proxy *px, struct bind_conf *conf, char **err)
+{
+	struct listener *l;
+
+	if (!*args[cur_arg + 1]) {
+		memprintf(err, "'%s' : missing label", args[cur_arg]);
+		return ERR_ALERT | ERR_FATAL;
+	}
+
+	list_for_each_entry(l, &conf->listeners, by_bind) {
+		free(l->label);
+		l->label = strdup(args[cur_arg + 1]);
+		if (!l->label) {
+			memprintf(err, "'%s %s' : out of memory", args[cur_arg], args[cur_arg + 1]);
+			return ERR_ALERT | ERR_FATAL;
+		}
+	}
+
+	return 0;
+}
+
 /* parse the "nbconn" bind keyword */
 static int bind_parse_nbconn(char **args, int cur_arg, struct proxy *px, struct bind_conf *conf, char **err)
 {
@@ -2628,6 +2657,7 @@ static struct bind_kw_list bind_kws = { "ALL", { }, {
 	{ "guid-prefix",  bind_parse_guid_prefix,  1, 1 }, /* set guid of listening socket */
 	{ "id",           bind_parse_id,           1, 1 }, /* set id of listening socket */
 	{ "idle-ping",    bind_parse_idle_ping,    1, 1 }, /* activate idle ping if mux support it */
+	{ "label",        bind_parse_label,        1, 1 }, /* set label of listening socket */
 	{ "maxconn",      bind_parse_maxconn,      1, 0 }, /* set maxconn of listening socket */
 	{ "name",         bind_parse_name,         1, 1 }, /* set name of listening socket */
 	{ "nbconn",       bind_parse_nbconn,       1, 1 }, /* set number of connection on active preconnect */

src/proxy.c

@@ -391,6 +391,7 @@ void deinit_proxy(struct proxy *p)
 		LIST_DELETE(&l->by_fe);
 		LIST_DELETE(&l->by_bind);
 		free(l->name);
+		free(l->label);
 		free(l->per_thr);
 		free(l->counters);
 		task_destroy(l->rx.rhttp.task);