/*

 * Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the Apache License 2.0 (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 */

#ifndef OSSL_INTERNAL_DSO_H

# define OSSL_INTERNAL_DSO_H

# include <openssl/crypto.h>

# include "internal/dsoerr.h"

/* These values are used as commands to DSO_ctrl() */

# define DSO_CTRL_GET_FLAGS      1

# define DSO_CTRL_SET_FLAGS      2

# define DSO_CTRL_OR_FLAGS       3

/*

 * By default, DSO_load() will translate the provided filename into a form

 * typical for the platform using the dso_name_converter function of the

 * method. Eg. win32 will transform "blah" into "blah.dll", and dlfcn will

 * transform it into "libblah.so". This callback could even utilise the

 * DSO_METHOD's converter too if it only wants to override behaviour for

 * one or two possible DSO methods. However, the following flag can be

 * set in a DSO to prevent *any* native name-translation at all - eg. if

 * the caller has prompted the user for a path to a driver library so the

 * filename should be interpreted as-is.

 */

# define DSO_FLAG_NO_NAME_TRANSLATION            0x01

/*

 * An extra flag to give if only the extension should be added as

 * translation.  This is obviously only of importance on Unix and other

 * operating systems where the translation also may prefix the name with

 * something, like 'lib', and ignored everywhere else. This flag is also

 * ignored if DSO_FLAG_NO_NAME_TRANSLATION is used at the same time.

 */

# define DSO_FLAG_NAME_TRANSLATION_EXT_ONLY      0x02

/*

 * Don't unload the DSO when we call DSO_free()

 */

# define DSO_FLAG_NO_UNLOAD_ON_FREE              0x04

/*

 * This flag loads the library with public symbols. Meaning: The exported

 * symbols of this library are public to all libraries loaded after this

 * library. At the moment only implemented in unix.

 */

# define DSO_FLAG_GLOBAL_SYMBOLS                 0x20

typedef void (*DSO_FUNC_TYPE) (void);

typedef struct dso_st DSO;

typedef struct dso_meth_st DSO_METHOD;

/*

 * The function prototype used for method functions (or caller-provided

 * callbacks) that transform filenames. They are passed a DSO structure

 * pointer (or NULL if they are to be used independently of a DSO object) and

 * a filename to transform. They should either return NULL (if there is an

 * error condition) or a newly allocated string containing the transformed

 * form that the caller will need to free with OPENSSL_free() when done.

 */

typedef char *(*DSO_NAME_CONVERTER_FUNC)(DSO *, const char *);

/*

 * The function prototype used for method functions (or caller-provided

 * callbacks) that merge two file specifications. They are passed a DSO

 * structure pointer (or NULL if they are to be used independently of a DSO

 * object) and two file specifications to merge. They should either return

 * NULL (if there is an error condition) or a newly allocated string

 * containing the result of merging that the caller will need to free with

 * OPENSSL_free() when done. Here, merging means that bits and pieces are

 * taken from each of the file specifications and added together in whatever

 * fashion that is sensible for the DSO method in question.  The only rule

 * that really applies is that if the two specification contain pieces of the

 * same type, the copy from the first string takes priority.  One could see

 * it as the first specification is the one given by the user and the second

 * being a bunch of defaults to add on if they're missing in the first.

 */

typedef char *(*DSO_MERGER_FUNC)(DSO *, const char *, const char *);

DSO *DSO_new(void);

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);

/*

 * These functions can be used to get/set the platform-independent 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);

/*

 * The all-singing all-dancing load function, you normally pass NULL for the

 * first and third parameters. Use DSO_up_ref and DSO_free for subsequent

 * reference count handling. Any flags passed in will be set in the

 * constructed DSO after its init() function but before the load operation.

 * If 'dso' is non-NULL, 'flags' is ignored.

 */

DSO *DSO_load(DSO *dso, const char *filename, DSO_METHOD *meth, int flags);

/* This function binds to a function inside a shared library. */

DSO_FUNC_TYPE DSO_bind_func(DSO *dso, const char *symname);

/*

 * This method is the default, but will beg, borrow, or steal whatever method

 * should be the default on any particular platform (including

 * DSO_METH_null() if necessary).

 */

DSO_METHOD *DSO_METHOD_openssl(void);

/*

 * This function writes null-terminated pathname of DSO module containing

 * 'addr' into 'sz' large caller-provided 'path' and returns the number of

 * characters [including trailing zero] written to it. If 'sz' is 0 or

 * negative, 'path' is ignored and required amount of characters [including

 * trailing zero] to accommodate pathname is returned. If 'addr' is NULL, then

 * pathname of cryptolib itself is returned. Negative or zero return value

 * denotes error.

 */

int DSO_pathbyaddr(void *addr, char *path, int sz);

/*

 * Like DSO_pathbyaddr() but instead returns a handle to the DSO for the symbol

 * or NULL on error.

 */

DSO *DSO_dsobyaddr(void *addr, int flags);

/*

 * This function should be used with caution! It looks up symbols in *all*

 * loaded modules and if module gets unloaded by somebody else attempt to

 * dereference the pointer is doomed to have fatal consequences. Primary

 * usage for this function is to probe *core* system functionality, e.g.

 * check if getnameinfo(3) is available at run-time without bothering about

 * OS-specific details such as libc.so.versioning or where does it actually

 * reside: in libc itself or libsocket.

 */

void *DSO_global_lookup(const char *name);

int ERR_load_DSO_strings(void);

#endif