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/*
* Copyright 2000-2020 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
# pragma once
# 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);
#endif
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