socket_util: added socket_bind_listen()

Moved code from listen_add_address() (listen.c) to socket_util.c.

src/socket_util.h

@@ -43,4 +43,24 @@ struct sockaddr;
 char *
 sockaddr_to_string(const struct sockaddr *sa, size_t length, GError **error);
 
+/**
+ * Creates a socket listening on the specified address.  This is a
+ * shortcut for socket(), bind() and listen().
+ *
+ * @param domain the socket domain, e.g. PF_INET6
+ * @param type the socket type, e.g. SOCK_STREAM
+ * @param protocol the protocol, usually 0 to let the kernel choose
+ * @param address the address to listen on
+ * @param address_length the size of #address
+ * @param backlog the backlog parameter for the listen() system call
+ * @param error location to store the error occuring, or NULL to
+ * ignore errors
+ * @return the socket file descriptor or -1 on error
+ */
+int
+socket_bind_listen(int domain, int type, int protocol,
+		   const struct sockaddr *address, size_t address_length,
+		   int backlog,
+		   GError **error);
+
 #endif