-int url_canon_split_rel(byte *url, byte *buf1, byte *buf2, struct url *u, struct url *base);
-int url_auto_canonicalize_rel(byte *src, byte *dst, struct url *base);
-uns identify_protocol(byte *p);
-int url_has_repeated_component(byte *url);
+int url_canon_split_rel(const byte *url, byte *buf1, byte *buf2, struct url *u, struct url *base);
+int url_auto_canonicalize_rel(const byte *src, byte *dst, struct url *base);
+uns identify_protocol(const byte *p);
+int url_has_repeated_component(const byte *url);