+struct dso_st {
+ DSO_METHOD *meth;
+ /*
+ * Standard dlopen uses a (void *). Win32 uses a HANDLE. VMS doesn't use
+ * anything but will need to cache the filename for use in the dso_bind
+ * handler. All in all, let each method control its own destiny.
+ * "Handles" and such go in a STACK.
+ */
+ STACK_OF(void) *meth_data;
+ int references;
+ int flags;
+ /*
+ * For use by applications etc ... use this for your bits'n'pieces, don't
+ * touch meth_data!
+ */
+ CRYPTO_EX_DATA ex_data;
+ /*
+ * If this callback function pointer is set to non-NULL, then it will be
+ * used in DSO_load() in place of meth->dso_name_converter. NB: This
+ * should normally set using DSO_set_name_converter().
+ */
+ DSO_NAME_CONVERTER_FUNC name_converter;
+ /*
+ * If this callback function pointer is set to non-NULL, then it will be
+ * used in DSO_load() in place of meth->dso_merger. NB: This should
+ * normally set using DSO_set_merger().
+ */
+ DSO_MERGER_FUNC merger;
+ /*
+ * This is populated with (a copy of) the platform-independant filename
+ * used for this DSO.
+ */
+ char *filename;
+ /*
+ * This is populated with (a copy of) the translated filename by which
+ * the DSO was actually loaded. It is NULL iff the DSO is not currently
+ * loaded. NB: This is here because the filename translation process may
+ * involve a callback being invoked more than once not only to convert to
+ * a platform-specific form, but also to try different filenames in the
+ * process of trying to perform a load. As such, this variable can be
+ * used to indicate (a) whether this DSO structure corresponds to a
+ * loaded library or not, and (b) the filename with which it was actually
+ * loaded.
+ */
+ char *loaded_filename;
+};
+
+DSO *DSO_new(void);
+DSO *DSO_new_method(DSO_METHOD *method);
+int DSO_free(DSO *dso);
+int DSO_flags(DSO *dso);
+int DSO_up_ref(DSO *dso);
+long DSO_ctrl(DSO *dso, int cmd, long larg, void *parg);
+
+/*
+ * This function sets the DSO's name_converter callback. If it is non-NULL,
+ * then it will be used instead of the associated DSO_METHOD's function. If
+ * oldcb is non-NULL then it is set to the function pointer value being
+ * replaced. Return value is non-zero for success.
+ */
+int DSO_set_name_converter(DSO *dso, DSO_NAME_CONVERTER_FUNC cb,
+ DSO_NAME_CONVERTER_FUNC *oldcb);
+/*
+ * These functions can be used to get/set the platform-independant filename
+ * used for a DSO. NB: set will fail if the DSO is already loaded.
+ */
+const char *DSO_get_filename(DSO *dso);
+int DSO_set_filename(DSO *dso, const char *filename);
+/*
+ * This function will invoke the DSO's name_converter callback to translate a
+ * filename, or if the callback isn't set it will instead use the DSO_METHOD's
+ * converter. If "filename" is NULL, the "filename" in the DSO itself will be
+ * used. If the DSO_FLAG_NO_NAME_TRANSLATION flag is set, then the filename is
+ * simply duplicated. NB: This function is usually called from within a
+ * DSO_METHOD during the processing of a DSO_load() call, and is exposed so
+ * that caller-created DSO_METHODs can do the same thing. A non-NULL return
+ * value will need to be OPENSSL_free()'d.
+ */
+char *DSO_convert_filename(DSO *dso, const char *filename);
+/*
+ * This function will invoke the DSO's merger callback to merge two file
+ * specifications, or if the callback isn't set it will instead use the
+ * DSO_METHOD's merger. A non-NULL return value will need to be
+ * OPENSSL_free()'d.
+ */
+char *DSO_merge(DSO *dso, const char *filespec1, const char *filespec2);
+/*
+ * If the DSO is currently loaded, this returns the filename that it was
+ * loaded under, otherwise it returns NULL. So it is also useful as a test as
+ * to whether the DSO is currently loaded. NB: This will not necessarily
+ * return the same value as DSO_convert_filename(dso, dso->filename), because
+ * the DSO_METHOD's load function may have tried a variety of filenames (with
+ * and/or without the aid of the converters) before settling on the one it
+ * actually loaded.
+ */
+const char *DSO_get_loaded_filename(DSO *dso);