/* * Copyright 2000-2021 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