Add listen mode

src/listen.c

@@ -0,0 +1,87 @@
+#include "listen.h"
+#include "serve.h"
+#include "util.h"
+
+#include <stdlib.h>
+
+struct listen * listen_create( 
+		char* s_ip_address, 
+		char* s_rebind_ip_address, 
+		char* s_port, 
+		char* s_rebind_port, 
+		char* s_file,
+		char *s_ctrl_sock, 
+		int default_deny,
+		int acl_entries, 
+		char** s_acl_entries,
+		int max_nbd_clients )
+{
+	struct listen * listen;
+
+	listen = (struct listen *)xmalloc( sizeof( listen ) );
+	listen->init_serve = server_create( s_ip_address, 
+			s_port, 
+			s_file,
+			s_ctrl_sock, 
+			default_deny, 
+			acl_entries, 
+			s_acl_entries, 
+			1, 0);
+	listen->main_serve = server_create( 
+			s_rebind_ip_address ? s_rebind_ip_address : s_ip_address, 
+			s_rebind_port ? s_rebind_port : s_port, 
+			s_file,
+			s_ctrl_sock, 
+			default_deny, 
+			acl_entries, 
+			s_acl_entries, 
+			max_nbd_clients, 1);
+	return listen;
+}
+
+
+void listen_destroy( struct listen * listen )
+{
+	NULLCHECK( listen );
+	free( listen );
+}
+
+
+void listen_switch( struct listen * listen )
+{
+	NULLCHECK( listen );
+
+	/* TODO: Copy acl from init_serve to main_serve */
+	/* TODO: rename underlying file from foo.INCOMPLETE to foo */
+}
+
+
+void listen_cleanup( void * unused __attribute__((unused)) )
+{
+}
+
+void do_listen( struct listen * listen )
+{
+	NULLCHECK( listen );
+
+	int have_control = 0;
+
+	have_control = do_serve( listen->init_serve );
+
+	if( have_control ) {
+		info( "Taking control.");
+		listen_switch( listen );
+		server_destroy( listen->init_serve );
+		info( "Switched to the main server, serving." );
+		do_serve( listen->main_serve );
+	}
+	else {
+		warn("Failed to take control, giving up.");
+		server_destroy( listen->init_serve );
+	}
+	server_destroy( listen->main_serve );
+
+	info("Listen done.");
+	listen_cleanup( listen );
+}
+