1 /* 2 * Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the OpenSSL license (the "License"). You may not use 5 * this file except in compliance with the License. You can obtain a copy 6 * in the file LICENSE in the source distribution or at 7 * https://www.openssl.org/source/license.html 8 */ 9 10 #ifndef OSSL_INTERNAL_DSO_H 11 # define OSSL_INTERNAL_DSO_H 12 13 # include <openssl/crypto.h> 14 # include "internal/dsoerr.h" 15 16 /* These values are used as commands to DSO_ctrl() */ 17 # define DSO_CTRL_GET_FLAGS 1 18 # define DSO_CTRL_SET_FLAGS 2 19 # define DSO_CTRL_OR_FLAGS 3 20 21 /* 22 * By default, DSO_load() will translate the provided filename into a form 23 * typical for the platform using the dso_name_converter function of the 24 * method. Eg. win32 will transform "blah" into "blah.dll", and dlfcn will 25 * transform it into "libblah.so". This callback could even utilise the 26 * DSO_METHOD's converter too if it only wants to override behaviour for 27 * one or two possible DSO methods. However, the following flag can be 28 * set in a DSO to prevent *any* native name-translation at all - eg. if 29 * the caller has prompted the user for a path to a driver library so the 30 * filename should be interpreted as-is. 31 */ 32 # define DSO_FLAG_NO_NAME_TRANSLATION 0x01 33 /* 34 * An extra flag to give if only the extension should be added as 35 * translation. This is obviously only of importance on Unix and other 36 * operating systems where the translation also may prefix the name with 37 * something, like 'lib', and ignored everywhere else. This flag is also 38 * ignored if DSO_FLAG_NO_NAME_TRANSLATION is used at the same time. 39 */ 40 # define DSO_FLAG_NAME_TRANSLATION_EXT_ONLY 0x02 41 42 /* 43 * Don't unload the DSO when we call DSO_free() 44 */ 45 # define DSO_FLAG_NO_UNLOAD_ON_FREE 0x04 46 47 /* 48 * This flag loads the library with public symbols. Meaning: The exported 49 * symbols of this library are public to all libraries loaded after this 50 * library. At the moment only implemented in unix. 51 */ 52 # define DSO_FLAG_GLOBAL_SYMBOLS 0x20 53 54 typedef void (*DSO_FUNC_TYPE) (void); 55 56 typedef struct dso_st DSO; 57 typedef struct dso_meth_st DSO_METHOD; 58 59 /* 60 * The function prototype used for method functions (or caller-provided 61 * callbacks) that transform filenames. They are passed a DSO structure 62 * pointer (or NULL if they are to be used independently of a DSO object) and 63 * a filename to transform. They should either return NULL (if there is an 64 * error condition) or a newly allocated string containing the transformed 65 * form that the caller will need to free with OPENSSL_free() when done. 66 */ 67 typedef char *(*DSO_NAME_CONVERTER_FUNC)(DSO *, const char *); 68 /* 69 * The function prototype used for method functions (or caller-provided 70 * callbacks) that merge two file specifications. They are passed a DSO 71 * structure pointer (or NULL if they are to be used independently of a DSO 72 * object) and two file specifications to merge. They should either return 73 * NULL (if there is an error condition) or a newly allocated string 74 * containing the result of merging that the caller will need to free with 75 * OPENSSL_free() when done. Here, merging means that bits and pieces are 76 * taken from each of the file specifications and added together in whatever 77 * fashion that is sensible for the DSO method in question. The only rule 78 * that really applies is that if the two specification contain pieces of the 79 * same type, the copy from the first string takes priority. One could see 80 * it as the first specification is the one given by the user and the second 81 * being a bunch of defaults to add on if they're missing in the first. 82 */ 83 typedef char *(*DSO_MERGER_FUNC)(DSO *, const char *, const char *); 84 85 DSO *DSO_new(void); 86 int DSO_free(DSO *dso); 87 int DSO_flags(DSO *dso); 88 int DSO_up_ref(DSO *dso); 89 long DSO_ctrl(DSO *dso, int cmd, long larg, void *parg); 90 91 /* 92 * These functions can be used to get/set the platform-independent filename 93 * used for a DSO. NB: set will fail if the DSO is already loaded. 94 */ 95 const char *DSO_get_filename(DSO *dso); 96 int DSO_set_filename(DSO *dso, const char *filename); 97 /* 98 * This function will invoke the DSO's name_converter callback to translate a 99 * filename, or if the callback isn't set it will instead use the DSO_METHOD's 100 * converter. If "filename" is NULL, the "filename" in the DSO itself will be 101 * used. If the DSO_FLAG_NO_NAME_TRANSLATION flag is set, then the filename is 102 * simply duplicated. NB: This function is usually called from within a 103 * DSO_METHOD during the processing of a DSO_load() call, and is exposed so 104 * that caller-created DSO_METHODs can do the same thing. A non-NULL return 105 * value will need to be OPENSSL_free()'d. 106 */ 107 char *DSO_convert_filename(DSO *dso, const char *filename); 108 /* 109 * This function will invoke the DSO's merger callback to merge two file 110 * specifications, or if the callback isn't set it will instead use the 111 * DSO_METHOD's merger. A non-NULL return value will need to be 112 * OPENSSL_free()'d. 113 */ 114 char *DSO_merge(DSO *dso, const char *filespec1, const char *filespec2); 115 116 /* 117 * The all-singing all-dancing load function, you normally pass NULL for the 118 * first and third parameters. Use DSO_up_ref and DSO_free for subsequent 119 * reference count handling. Any flags passed in will be set in the 120 * constructed DSO after its init() function but before the load operation. 121 * If 'dso' is non-NULL, 'flags' is ignored. 122 */ 123 DSO *DSO_load(DSO *dso, const char *filename, DSO_METHOD *meth, int flags); 124 125 /* This function binds to a function inside a shared library. */ 126 DSO_FUNC_TYPE DSO_bind_func(DSO *dso, const char *symname); 127 128 /* 129 * This method is the default, but will beg, borrow, or steal whatever method 130 * should be the default on any particular platform (including 131 * DSO_METH_null() if necessary). 132 */ 133 DSO_METHOD *DSO_METHOD_openssl(void); 134 135 /* 136 * This function writes null-terminated pathname of DSO module containing 137 * 'addr' into 'sz' large caller-provided 'path' and returns the number of 138 * characters [including trailing zero] written to it. If 'sz' is 0 or 139 * negative, 'path' is ignored and required amount of characters [including 140 * trailing zero] to accommodate pathname is returned. If 'addr' is NULL, then 141 * pathname of cryptolib itself is returned. Negative or zero return value 142 * denotes error. 143 */ 144 int DSO_pathbyaddr(void *addr, char *path, int sz); 145 146 /* 147 * Like DSO_pathbyaddr() but instead returns a handle to the DSO for the symbol 148 * or NULL on error. 149 */ 150 DSO *DSO_dsobyaddr(void *addr, int flags); 151 152 /* 153 * This function should be used with caution! It looks up symbols in *all* 154 * loaded modules and if module gets unloaded by somebody else attempt to 155 * dereference the pointer is doomed to have fatal consequences. Primary 156 * usage for this function is to probe *core* system functionality, e.g. 157 * check if getnameinfo(3) is available at run-time without bothering about 158 * OS-specific details such as libc.so.versioning or where does it actually 159 * reside: in libc itself or libsocket. 160 */ 161 void *DSO_global_lookup(const char *name); 162 163 int ERR_load_DSO_strings(void); 164 165 #endif 166
Indexes created Sun Mar 01 05:31:48 UTC 2026