1 /* 2 * util/fptr_wlist.h - function pointer whitelists. 3 * 4 * Copyright (c) 2007, NLnet Labs. All rights reserved. 5 * 6 * This software is open source. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * Redistributions of source code must retain the above copyright notice, 13 * this list of conditions and the following disclaimer. 14 * 15 * Redistributions in binary form must reproduce the above copyright notice, 16 * this list of conditions and the following disclaimer in the documentation 17 * and/or other materials provided with the distribution. 18 * 19 * Neither the name of the NLNET LABS nor the names of its contributors may 20 * be used to endorse or promote products derived from this software without 21 * specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 24 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 25 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 26 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 27 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 29 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 30 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 31 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 32 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 33 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 34 */ 35 36 /** 37 * \file 38 * 39 * This file contains functions that check function pointers. 40 * The functions contain a whitelist of known good callback values. 41 * Any other values lead to an error. 42 * 43 * This prevent heap overflow based exploits, where the callback pointer 44 * is overwritten by a buffer overflow (apart from this defense, buffer 45 * overflows should be fixed of course). 46 * 47 * Function pointers are used in 48 * o network code callbacks. 49 * o rbtree, lruhash, region data manipulation 50 * in lruhash, the assertions are before the critical regions. 51 * in other places, assertions are before the callback. 52 * o module operations. 53 */ 54 55 #ifndef UTIL_FPTR_WLIST_H 56 #define UTIL_FPTR_WLIST_H 57 #include "util/netevent.h" 58 #include "util/storage/lruhash.h" 59 #include "util/module.h" 60 #include "util/tube.h" 61 #include "services/mesh.h" 62 63 /** 64 * Macro to perform an assertion check for fptr wlist checks. 65 * Does not get disabled in optimize mode. Check adds security by layers. 66 */ 67 #if defined(EXPORT_ALL_SYMBOLS) 68 #define fptr_ok(x) /* nothing, dll-exe memory layout on win disables it */ 69 #else 70 #define fptr_ok(x) \ 71 do { if(!(x)) \ 72 fatal_exit("%s:%d: %s: pointer whitelist %s failed", \ 73 __FILE__, __LINE__, __func__, #x); \ 74 } while(0); 75 #endif 76 77 /** 78 * Check function pointer whitelist for comm_point callback values. 79 * 80 * @param fptr: function pointer to check. 81 * @return false if not in whitelist. 82 */ 83 int fptr_whitelist_comm_point(comm_point_callback_t *fptr); 84 85 /** 86 * Check function pointer whitelist for raw comm_point callback values. 87 * 88 * @param fptr: function pointer to check. 89 * @return false if not in whitelist. 90 */ 91 int fptr_whitelist_comm_point_raw(comm_point_callback_t *fptr); 92 93 /** 94 * Check function pointer whitelist for comm_timer callback values. 95 * 96 * @param fptr: function pointer to check. 97 * @return false if not in whitelist. 98 */ 99 int fptr_whitelist_comm_timer(void (*fptr)(void*)); 100 101 /** 102 * Check function pointer whitelist for comm_signal callback values. 103 * 104 * @param fptr: function pointer to check. 105 * @return false if not in whitelist. 106 */ 107 int fptr_whitelist_comm_signal(void (*fptr)(int, void*)); 108 109 /** 110 * Check function pointer whitelist for start_accept callback values. 111 * 112 * @param fptr: function pointer to check. 113 * @return false if not in whitelist. 114 */ 115 int fptr_whitelist_start_accept(void (*fptr)(void*)); 116 117 /** 118 * Check function pointer whitelist for stop_accept callback values. 119 * 120 * @param fptr: function pointer to check. 121 * @return false if not in whitelist. 122 */ 123 int fptr_whitelist_stop_accept(void (*fptr)(void*)); 124 125 /** 126 * Check function pointer whitelist for event structure callback values. 127 * This is not called by libevent itself, but checked by netevent. 128 * 129 * @param fptr: function pointer to check. 130 * @return false if not in whitelist. 131 */ 132 int fptr_whitelist_event(void (*fptr)(int, short, void *)); 133 134 /** 135 * Check function pointer whitelist for pending udp callback values. 136 * 137 * @param fptr: function pointer to check. 138 * @return false if not in whitelist. 139 */ 140 int fptr_whitelist_pending_udp(comm_point_callback_t *fptr); 141 142 /** 143 * Check function pointer whitelist for pending tcp callback values. 144 * 145 * @param fptr: function pointer to check. 146 * @return false if not in whitelist. 147 */ 148 int fptr_whitelist_pending_tcp(comm_point_callback_t *fptr); 149 150 /** 151 * Check function pointer whitelist for serviced query callback values. 152 * 153 * @param fptr: function pointer to check. 154 * @return false if not in whitelist. 155 */ 156 int fptr_whitelist_serviced_query(comm_point_callback_t *fptr); 157 158 /** 159 * Check function pointer whitelist for rbtree cmp callback values. 160 * 161 * @param fptr: function pointer to check. 162 * @return false if not in whitelist. 163 */ 164 int fptr_whitelist_rbtree_cmp(int (*fptr) (const void *, const void *)); 165 166 /** 167 * Check function pointer whitelist for lruhash sizefunc callback values. 168 * 169 * @param fptr: function pointer to check. 170 * @return false if not in whitelist. 171 */ 172 int fptr_whitelist_hash_sizefunc(lruhash_sizefunc_t fptr); 173 174 /** 175 * Check function pointer whitelist for lruhash compfunc callback values. 176 * 177 * @param fptr: function pointer to check. 178 * @return false if not in whitelist. 179 */ 180 int fptr_whitelist_hash_compfunc(lruhash_compfunc_t fptr); 181 182 /** 183 * Check function pointer whitelist for lruhash delkeyfunc callback values. 184 * 185 * @param fptr: function pointer to check. 186 * @return false if not in whitelist. 187 */ 188 int fptr_whitelist_hash_delkeyfunc(lruhash_delkeyfunc_t fptr); 189 190 /** 191 * Check function pointer whitelist for lruhash deldata callback values. 192 * 193 * @param fptr: function pointer to check. 194 * @return false if not in whitelist. 195 */ 196 int fptr_whitelist_hash_deldatafunc(lruhash_deldatafunc_t fptr); 197 198 /** 199 * Check function pointer whitelist for lruhash markdel callback values. 200 * 201 * @param fptr: function pointer to check. 202 * @return false if not in whitelist. 203 */ 204 int fptr_whitelist_hash_markdelfunc(lruhash_markdelfunc_t fptr); 205 206 /** 207 * Check function pointer whitelist for module_env send_query callback values. 208 * 209 * @param fptr: function pointer to check. 210 * @return false if not in whitelist. 211 */ 212 int fptr_whitelist_modenv_send_query(struct outbound_entry* (*fptr)( 213 uint8_t* qname, size_t qnamelen, uint16_t qtype, uint16_t qclass, 214 uint16_t flags, int dnssec, int want_dnssec, int nocaps, 215 struct sockaddr_storage* addr, socklen_t addrlen, 216 uint8_t* zone, size_t zonelen, 217 struct module_qstate* q)); 218 219 /** 220 * Check function pointer whitelist for module_env detach_subs callback values. 221 * 222 * @param fptr: function pointer to check. 223 * @return false if not in whitelist. 224 */ 225 int fptr_whitelist_modenv_detach_subs(void (*fptr)( 226 struct module_qstate* qstate)); 227 228 /** 229 * Check function pointer whitelist for module_env attach_sub callback values. 230 * 231 * @param fptr: function pointer to check. 232 * @return false if not in whitelist. 233 */ 234 int fptr_whitelist_modenv_attach_sub(int (*fptr)( 235 struct module_qstate* qstate, struct query_info* qinfo, 236 uint16_t qflags, int prime, int valrec, struct module_qstate** newq)); 237 238 /** 239 * Check function pointer whitelist for module_env kill_sub callback values. 240 * 241 * @param fptr: function pointer to check. 242 * @return false if not in whitelist. 243 */ 244 int fptr_whitelist_modenv_kill_sub(void (*fptr)(struct module_qstate* newq)); 245 246 /** 247 * Check function pointer whitelist for module_env detect_cycle callback values. 248 * 249 * @param fptr: function pointer to check. 250 * @return false if not in whitelist. 251 */ 252 int fptr_whitelist_modenv_detect_cycle(int (*fptr)( 253 struct module_qstate* qstate, struct query_info* qinfo, 254 uint16_t flags, int prime, int valrec)); 255 256 /** 257 * Check function pointer whitelist for module init call values. 258 * 259 * @param fptr: function pointer to check. 260 * @return false if not in whitelist. 261 */ 262 int fptr_whitelist_mod_init(int (*fptr)(struct module_env* env, int id)); 263 264 /** 265 * Check function pointer whitelist for module deinit call values. 266 * 267 * @param fptr: function pointer to check. 268 * @return false if not in whitelist. 269 */ 270 int fptr_whitelist_mod_deinit(void (*fptr)(struct module_env* env, int id)); 271 272 /** 273 * Check function pointer whitelist for module operate call values. 274 * 275 * @param fptr: function pointer to check. 276 * @return false if not in whitelist. 277 */ 278 int fptr_whitelist_mod_operate(void (*fptr)(struct module_qstate* qstate, 279 enum module_ev event, int id, struct outbound_entry* outbound)); 280 281 /** 282 * Check function pointer whitelist for module inform_super call values. 283 * 284 * @param fptr: function pointer to check. 285 * @return false if not in whitelist. 286 */ 287 int fptr_whitelist_mod_inform_super(void (*fptr)( 288 struct module_qstate* qstate, int id, struct module_qstate* super)); 289 290 /** 291 * Check function pointer whitelist for module clear call values. 292 * 293 * @param fptr: function pointer to check. 294 * @return false if not in whitelist. 295 */ 296 int fptr_whitelist_mod_clear(void (*fptr)(struct module_qstate* qstate, 297 int id)); 298 299 /** 300 * Check function pointer whitelist for module get_mem call values. 301 * 302 * @param fptr: function pointer to check. 303 * @return false if not in whitelist. 304 */ 305 int fptr_whitelist_mod_get_mem(size_t (*fptr)(struct module_env* env, int id)); 306 307 /** 308 * Check function pointer whitelist for alloc clear on id overflow call values. 309 * 310 * @param fptr: function pointer to check. 311 * @return false if not in whitelist. 312 */ 313 int fptr_whitelist_alloc_cleanup(void (*fptr)(void*)); 314 315 /** 316 * Check function pointer whitelist for tube listen handler values. 317 * 318 * @param fptr: function pointer to check. 319 * @return false if not in whitelist. 320 */ 321 int fptr_whitelist_tube_listen(tube_callback_t* fptr); 322 323 /** 324 * Check function pointer whitelist for mesh state callback values. 325 * 326 * @param fptr: function pointer to check. 327 * @return false if not in whitelist. 328 */ 329 int fptr_whitelist_mesh_cb(mesh_cb_func_t fptr); 330 331 /** 332 * Check function pointer whitelist for config_get_option func values. 333 * @param fptr: function pointer to check. 334 * @return false if not in whitelist. 335 */ 336 int fptr_whitelist_print_func(void (*fptr)(char*,void*)); 337 338 /** Due to module breakage by fptr wlist, these test app declarations 339 * are presented here */ 340 /** 341 * compare two order_ids from lock-verify test app 342 * @param e1: first order_id 343 * @param e2: second order_id 344 * @return compare code -1, 0, +1 (like memcmp). 345 */ 346 int order_lock_cmp(const void* e1, const void* e2); 347 348 /** 349 * compare two codeline structs for rbtree from memstats test app 350 * @param a: codeline 351 * @param b: codeline 352 * @return compare code -1, 0, +1 (like memcmp). 353 */ 354 int codeline_cmp(const void* a, const void* b); 355 356 /** compare two replay_vars */ 357 int replay_var_compare(const void* a, const void* b); 358 359 #endif /* UTIL_FPTR_WLIST_H */ 360