Add avahi code to look for the rmeote control information for the cli…

…ent and get the port number from it.

.gitignore

@@ -23,6 +23,7 @@ man/Makefile
 man/Makefile.in
 scripts/shairport-sync.service
 scripts/shairport-sync
+shairport-sync.core
 
 #Some dbus files that are automatically generated
 dbus/data/org.gnome.ShairportSync.service

mdns.c

@@ -104,6 +104,22 @@ void mdns_unregister(void) {
   }
 }
 
+void mdns_dacp_monitor(char* dacp_id,uint16_t *port,void** private_pointer) {
+  if ((config.mdns) && (config.mdns->mdns_dacp_monitor)) {
+    int error = config.mdns->mdns_dacp_monitor(dacp_id,port,private_pointer);
+    if (error) {
+  		debug(1,"Error starting a DACP monitor.");
+    }
+  } else
+  	debug(1,"Can't start a DACP monitor.");
+}
+
+void mdns_dacp_dont_monitor(void** private_pointer) {
+  if ((config.mdns) && (config.mdns->mdns_dacp_dont_monitor)) {
+    config.mdns->mdns_dacp_dont_monitor(private_pointer);
+  } else
+  	debug(1,"Can't stop a DACP monitor.");
+}
 void mdns_ls_backends(void) {
   mdns_backend **b = NULL;
   printf("Available mDNS backends: \n");

mdns.h

@@ -1,18 +1,24 @@
 #ifndef _MDNS_H
 #define _MDNS_H
 
+#include <stdint.h>
 #include "config.h"
 
 extern int mdns_pid;
 
 void mdns_unregister(void);
 void mdns_register(void);
+void mdns_dacp_monitor(char* dacp_id,uint16_t *port,void** private_pointer);
+void mdns_dacp_dont_monitor(void** private_pointer);
+
 void mdns_ls_backends(void);
 
 typedef struct {
   char *name;
   int (*mdns_register)(char *apname, int port);
   void (*mdns_unregister)(void);
+  int (*mdns_dacp_monitor)(char* dacp_id,uint16_t *port,void** private_pointer);
+  void (*mdns_dacp_dont_monitor)(void** private_pointer);
 } mdns_backend;
 
 #ifdef CONFIG_METADATA