asterisk: add an 'interface' option to trigger reregister events

If set this now automatically re-registers all outbound registrations when
the interface is becoming available. This ensures that no stale IPs are
registered at the SIP trunk.

Fixes #681

Signed-off-by: Andre Heider <a.heider@gmail.com>

net/asterisk/files/asterisk.conf

@@ -11,6 +11,7 @@
 
 config asterisk 'general'
 	option enabled '0'
+	option interface 'wan'
 	option log_stderr '1'
 	option log_stdout '0'
 	option options ''

net/asterisk/files/asterisk.init

@@ -76,3 +76,11 @@ reregister() {
     $COMMAND -x 'pjsip send unregister *all' -x 'pjsip send register *all'
   }
 }
+
+service_triggers() {
+  config_load $NAME
+  config_get_bool enabled general enabled 0
+  config_get interface general interface ""
+
+  [ $enabled -eq 1 -a -n "$interface" ] && procd_add_interface_trigger "interface.*.up" "$interface" /etc/init.d/$NAME reregister
+}