Add utility function to parse port from URI

src/core/uri.c

@@ -159,3 +159,14 @@ struct uri * parse_uri ( const char *uri_string ) {
 
 	return uri;
 }
+
+/**
+ * Get port from URI
+ *
+ * @v uri		URI
+ * @v default_port	Default port to use if none specified in URI
+ * @ret port		Port
+ */
+unsigned int uri_port ( struct uri *uri, unsigned int default_port ) {
+	return ( uri->port ? strtoul ( uri->port, NULL, 0 ) : default_port );
+}

src/include/gpxe/uri.h

@@ -112,5 +112,6 @@ static inline void free_uri ( struct uri *uri ) {
 }
 
 extern struct uri * parse_uri ( const char *uri_string );
+unsigned int uri_port ( struct uri *uri, unsigned int default_port );
 
 #endif /* _GPXE_URI_H */