prototype.c revision 97485501f87e5452bc49721003ebfb9717f497b6
1/* 2 * This file is part of ltrace. 3 * Copyright (C) 2012,2013 Petr Machata, Red Hat Inc. 4 * 5 * This program is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU General Public License as 7 * published by the Free Software Foundation; either version 2 of the 8 * License, or (at your option) any later version. 9 * 10 * This program is distributed in the hope that it will be useful, but 11 * WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 * General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 18 * 02110-1301 USA 19 */ 20 21#include <alloca.h> 22#include <errno.h> 23#include <stdlib.h> 24#include <string.h> 25#include <stdio.h> 26 27#include "common.h" 28#include "callback.h" 29#include "param.h" 30#include "prototype.h" 31#include "type.h" 32#include "options.h" 33#include "read_config_file.h" 34#include "backend.h" 35 36struct protolib_cache g_protocache; 37static struct protolib legacy_typedefs; 38 39void 40prototype_init(struct prototype *proto) 41{ 42 VECT_INIT(&proto->params, struct param); 43 44 proto->return_info = NULL; 45 proto->own_return_info = 0; 46} 47 48static void 49param_destroy_cb(struct param *param, void *data) 50{ 51 param_destroy(param); 52} 53 54void 55prototype_destroy(struct prototype *proto) 56{ 57 if (proto == NULL) 58 return; 59 if (proto->own_return_info) { 60 type_destroy(proto->return_info); 61 free(proto->return_info); 62 } 63 64 VECT_DESTROY(&proto->params, struct param, ¶m_destroy_cb, NULL); 65} 66 67int 68prototype_push_param(struct prototype *proto, struct param *param) 69{ 70 return VECT_PUSHBACK(&proto->params, param); 71} 72 73size_t 74prototype_num_params(struct prototype *proto) 75{ 76 return vect_size(&proto->params); 77} 78 79void 80prototype_destroy_nth_param(struct prototype *proto, size_t n) 81{ 82 assert(n < prototype_num_params(proto)); 83 VECT_ERASE(&proto->params, struct param, n, n+1, 84 ¶m_destroy_cb, NULL); 85} 86 87struct param * 88prototype_get_nth_param(struct prototype *proto, size_t n) 89{ 90 assert(n < prototype_num_params(proto)); 91 return VECT_ELEMENT(&proto->params, struct param, n); 92} 93 94struct each_param_data { 95 struct prototype *proto; 96 enum callback_status (*cb)(struct prototype *, struct param *, void *); 97 void *data; 98}; 99 100static enum callback_status 101each_param_cb(struct param *param, void *data) 102{ 103 struct each_param_data *cb_data = data; 104 return (cb_data->cb)(cb_data->proto, param, cb_data->data); 105} 106 107struct param * 108prototype_each_param(struct prototype *proto, struct param *start_after, 109 enum callback_status (*cb)(struct prototype *, 110 struct param *, void *), 111 void *data) 112{ 113 struct each_param_data cb_data = { proto, cb, data }; 114 return VECT_EACH(&proto->params, struct param, start_after, 115 &each_param_cb, &cb_data); 116} 117 118void 119named_type_init(struct named_type *named, 120 struct arg_type_info *info, int own_type) 121{ 122 named->info = info; 123 named->own_type = own_type; 124 named->forward = 0; 125} 126 127void 128named_type_destroy(struct named_type *named) 129{ 130 if (named->own_type) { 131 type_destroy(named->info); 132 free(named->info); 133 } 134} 135 136void 137protolib_init(struct protolib *plib) 138{ 139 DICT_INIT(&plib->prototypes, char *, struct prototype, 140 dict_hash_string, dict_eq_string, NULL); 141 142 DICT_INIT(&plib->named_types, char *, struct named_type, 143 dict_hash_string, dict_eq_string, NULL); 144 145 VECT_INIT(&plib->imports, struct protolib *); 146 147 plib->refs = 0; 148} 149 150static void 151destroy_prototype_cb(struct prototype *proto, void *data) 152{ 153 prototype_destroy(proto); 154} 155 156static void 157destroy_named_type_cb(struct named_type *named, void *data) 158{ 159 named_type_destroy(named); 160} 161 162void 163protolib_destroy(struct protolib *plib) 164{ 165 assert(plib->refs == 0); 166 167 VECT_DESTROY(&plib->imports, struct prototype *, NULL, NULL); 168 169 DICT_DESTROY(&plib->prototypes, const char *, struct prototype, 170 dict_dtor_string, destroy_prototype_cb, NULL); 171 172 DICT_DESTROY(&plib->named_types, const char *, struct named_type, 173 dict_dtor_string, destroy_named_type_cb, NULL); 174} 175 176static struct protolib ** 177each_import(struct protolib *plib, struct protolib **start_after, 178 enum callback_status (*cb)(struct protolib **, void *), void *data) 179{ 180 assert(plib != NULL); 181 return VECT_EACH(&plib->imports, struct protolib *, 182 start_after, cb, data); 183} 184 185static enum callback_status 186is_or_imports(struct protolib **plibp, void *data) 187{ 188 assert(plibp != NULL); 189 assert(*plibp != NULL); 190 struct protolib *import = data; 191 if (*plibp == import 192 || each_import(*plibp, NULL, &is_or_imports, import) != NULL) 193 return CBS_STOP; 194 else 195 return CBS_CONT; 196} 197 198int 199protolib_add_import(struct protolib *plib, struct protolib *import) 200{ 201 assert(plib != NULL); 202 assert(import != NULL); 203 if (is_or_imports(&import, plib) == CBS_STOP) { 204 fprintf(stderr, "Recursive import rejected.\n"); 205 return -2; 206 } 207 208 return VECT_PUSHBACK(&plib->imports, &import) < 0 ? -1 : 0; 209} 210 211static int 212bailout(const char *name, int own) 213{ 214 int save_errno = errno; 215 if (own) 216 free((char *)name); 217 errno = save_errno; 218 return -1; 219} 220 221int 222protolib_add_prototype(struct protolib *plib, const char *name, int own_name, 223 struct prototype *proto) 224{ 225 assert(plib != NULL); 226 if (strdup_if(&name, name, !own_name) < 0) 227 return -1; 228 if (DICT_INSERT(&plib->prototypes, &name, proto) < 0) 229 return bailout(name, own_name); 230 return 0; 231} 232 233int 234protolib_add_named_type(struct protolib *plib, const char *name, int own_name, 235 struct named_type *named) 236{ 237 assert(plib != NULL); 238 if (strdup_if(&name, name, !own_name) < 0) 239 return -1; 240 if (DICT_INSERT(&plib->named_types, &name, named) < 0) 241 return bailout(name, own_name); 242 return 0; 243} 244 245struct lookup { 246 const char *name; 247 void *result; 248 struct dict *(*getter)(struct protolib *plib); 249}; 250 251static struct dict * 252get_prototypes(struct protolib *plib) 253{ 254 assert(plib != NULL); 255 return &plib->prototypes; 256} 257 258static struct dict * 259get_named_types(struct protolib *plib) 260{ 261 assert(plib != NULL); 262 return &plib->named_types; 263} 264 265static enum callback_status 266protolib_lookup_rec(struct protolib **plibp, void *data) 267{ 268 assert(plibp != NULL); 269 assert(*plibp != NULL); 270 struct lookup *lookup = data; 271 struct dict *dict = (*lookup->getter)(*plibp); 272 273 lookup->result = dict_find(dict, &lookup->name); 274 if (lookup->result != NULL) 275 return CBS_STOP; 276 277 if (each_import(*plibp, NULL, &protolib_lookup_rec, lookup) != NULL) { 278 assert(lookup->result != NULL); 279 return CBS_STOP; 280 } 281 282 return CBS_CONT; 283} 284 285static void * 286protolib_lookup(struct protolib *plib, const char *name, 287 struct dict *(*getter)(struct protolib *)) 288{ 289 assert(plib != NULL); 290 struct lookup lookup = { name, NULL, getter }; 291 if (protolib_lookup_rec(&plib, &lookup) == CBS_STOP) 292 assert(lookup.result != NULL); 293 else 294 assert(lookup.result == NULL); 295 return lookup.result; 296} 297 298struct prototype * 299protolib_lookup_prototype(struct protolib *plib, const char *name) 300{ 301 assert(plib != NULL); 302 return protolib_lookup(plib, name, &get_prototypes); 303} 304 305struct named_type * 306protolib_lookup_type(struct protolib *plib, const char *name) 307{ 308 assert(plib != NULL); 309 return protolib_lookup(plib, name, &get_named_types); 310} 311 312static void 313destroy_protolib_cb(struct protolib **plibp, void *data) 314{ 315 assert(plibp != NULL); 316 317 if (*plibp != NULL 318 && --(*plibp)->refs == 0) { 319 protolib_destroy(*plibp); 320 free(*plibp); 321 } 322} 323 324void 325protolib_cache_destroy(struct protolib_cache *cache) 326{ 327 DICT_DESTROY(&cache->protolibs, const char *, struct protolib *, 328 dict_dtor_string, destroy_protolib_cb, NULL); 329} 330 331struct load_config_data { 332 struct protolib_cache *self; 333 const char *key; 334 struct protolib *result; 335}; 336 337static struct protolib * 338consider_config_dir(struct protolib_cache *cache, 339 const char *path, const char *key) 340{ 341 size_t len = sizeof ".conf"; 342 char slash[2] = {'/'}; 343 char *buf = alloca(strlen(path) + 1 + strlen(key) + len); 344 strcpy(stpcpy(stpcpy(stpcpy(buf, path), slash), key), ".conf"); 345 346 return protolib_cache_file(cache, buf, 0); 347} 348 349static enum callback_status 350consider_confdir_cb(struct opt_F_t *entry, void *d) 351{ 352 if (opt_F_get_kind(entry) != OPT_F_DIR) 353 return CBS_CONT; 354 struct load_config_data *data = d; 355 356 data->result = consider_config_dir(data->self, 357 entry->pathname, data->key); 358 return data->result != NULL ? CBS_STOP : CBS_CONT; 359} 360 361static int 362load_dash_F_dirs(struct protolib_cache *cache, 363 const char *key, struct protolib **retp) 364{ 365 struct load_config_data data = {cache, key}; 366 367 if (VECT_EACH(&opt_F, struct opt_F_t, NULL, 368 consider_confdir_cb, &data) == NULL) 369 /* Not found. That's fine. */ 370 return 0; 371 372 if (data.result == NULL) 373 /* There were errors. */ 374 return -1; 375 376 *retp = data.result; 377 return 0; 378} 379 380static int 381load_config(struct protolib_cache *cache, 382 const char *key, int private, struct protolib **retp) 383{ 384 const char **dirs = NULL; 385 if (os_get_config_dirs(private, &dirs) < 0 386 || dirs == NULL) 387 return -1; 388 389 for (; *dirs != NULL; ++dirs) { 390 struct protolib *plib = consider_config_dir(cache, *dirs, key); 391 if (plib != NULL) { 392 *retp = plib; 393 break; 394 } 395 } 396 397 return 0; 398} 399 400static int 401add_ltrace_conf(struct protolib_cache *cache) 402{ 403 /* Look into private config directories for .ltrace.conf and 404 * into system config directories for ltrace.conf. If it's 405 * found, add it to implicit import module. */ 406 struct protolib *plib = NULL; 407 const char *home = NULL; 408 if (os_get_ltrace_conf_filename(&home) < 0 409 || (home != NULL 410 && (plib = consider_config_dir(cache, home, ".ltrace")) != NULL 411 && protolib_add_import(&cache->imports, plib) < 0) 412 || (plib == NULL && load_config(cache, "ltrace", 0, &plib) < 0) 413 || (plib != NULL && protolib_add_import(&cache->imports, plib) < 0)) 414 /* N.B. If plib is non-NULL, it has been already 415 * cached. We don't therefore destroy it on 416 * failures. */ 417 return -1; 418 419 /* Never mind whether we've found anything. It's fine if the 420 * config is absent. */ 421 return 0; 422} 423 424static enum callback_status 425add_imports_cb(struct opt_F_t *entry, void *data) 426{ 427 struct protolib_cache *self = data; 428 if (opt_F_get_kind(entry) != OPT_F_FILE) 429 return CBS_CONT; 430 431 struct protolib *new_import 432 = protolib_cache_file(self, entry->pathname, 0); 433 434 if (new_import == NULL 435 || protolib_add_import(&self->imports, new_import) < 0) 436 /* N.B. If new_import is non-NULL, it has been already 437 * cached. We don't therefore destroy it on 438 * failures. */ 439 return CBS_STOP; 440 441 return CBS_CONT; 442} 443 444int 445protolib_cache_init(struct protolib_cache *cache, struct protolib *import) 446{ 447 DICT_INIT(&cache->protolibs, char *, struct protolib *, 448 dict_hash_string, dict_eq_string, NULL); 449 protolib_init(&cache->imports); 450 451 /* At this point the cache is consistent. This is important, 452 * because next we will use it to cache files that we load 453 * due to -F. 454 * 455 * But we are about to construct the implicit import module, 456 * which means this module can't be itself imported to the 457 * files that we load now. So remember that we are still 458 * bootstrapping. */ 459 cache->bootstrap = 1; 460 461 if (protolib_add_import(&cache->imports, &legacy_typedefs) < 0 462 || (import != NULL 463 && protolib_add_import(&cache->imports, import) < 0) 464 || add_ltrace_conf(cache) < 0 465 || VECT_EACH(&opt_F, struct opt_F_t, NULL, 466 add_imports_cb, cache) != NULL) { 467 protolib_cache_destroy(cache); 468 return -1; 469 } 470 471 cache->bootstrap = 0; 472 return 0; 473} 474 475static enum callback_status 476add_import_cb(struct protolib **importp, void *data) 477{ 478 struct protolib *plib = data; 479 if (protolib_add_import(plib, *importp) < 0) 480 return CBS_STOP; 481 else 482 return CBS_CONT; 483} 484 485static struct protolib * 486build_default_config(struct protolib_cache *cache, const char *key) 487{ 488 struct protolib *new_plib = malloc(sizeof(*new_plib)); 489 if (new_plib == NULL) { 490 fprintf(stderr, "Couldn't create config module %s: %s\n", 491 key, strerror(errno)); 492 return NULL; 493 } 494 495 protolib_init(new_plib); 496 497 /* If bootstrapping, copy over imports from implicit import 498 * module to new_plib. We can't reference the implicit 499 * import module itself, because new_plib will become part of 500 * this same implicit import module itself. */ 501 if ((cache->bootstrap && each_import(&cache->imports, NULL, 502 add_import_cb, new_plib) != NULL) 503 || (!cache->bootstrap 504 && protolib_add_import(new_plib, &cache->imports) < 0)) { 505 506 fprintf(stderr, 507 "Couldn't add imports to config module %s: %s\n", 508 key, strerror(errno)); 509 protolib_destroy(new_plib); 510 free(new_plib); 511 return NULL; 512 } 513 514 return new_plib; 515} 516 517static void 518attempt_to_cache(struct protolib_cache *cache, 519 const char *key, struct protolib *plib) 520{ 521 if (protolib_cache_protolib(cache, key, 1, plib) == 0 522 || plib == NULL) 523 /* Never mind failing to store a NULL. */ 524 return; 525 526 /* Returning a protolib that hasn't been cached would leak 527 * that protolib, but perhaps it's less bad then giving up 528 * outright. At least print an error message. */ 529 fprintf(stderr, "Couldn't cache prototype library for %s\n", key); 530} 531 532struct protolib * 533protolib_cache_search(struct protolib_cache *cache, 534 const char *key, int own_key, int allow_private) 535{ 536 struct protolib *plib = NULL; 537 if (DICT_FIND_VAL(&cache->protolibs, &key, &plib) == 0) 538 return plib; 539 540 if (strdup_if(&key, key, !own_key) < 0) { 541 fprintf(stderr, "Couldn't cache %s: %s\n", 542 key, strerror(errno)); 543 return NULL; 544 } 545 546 /* The order is: -F directories, private directories, system 547 * directories. If the config file is not found anywhere, 548 * build a default one. */ 549 if (load_dash_F_dirs(cache, key, &plib) < 0 550 || (plib == NULL && allow_private 551 && load_config(cache, key, 1, &plib) < 0) 552 || (plib == NULL 553 && load_config(cache, key, 0, &plib) < 0) 554 || (plib == NULL 555 && (plib = build_default_config(cache, key)) == NULL)) 556 fprintf(stderr, 557 "Error occurred when attempting to load a prototype " 558 "library for %s.\n", key); 559 560 /* Whatever came out of this (even NULL), store it in the 561 * cache. */ 562 attempt_to_cache(cache, key, plib); 563 return plib; 564} 565 566struct protolib * 567protolib_cache_file(struct protolib_cache *cache, 568 const char *filename, int own_filename) 569{ 570 { 571 struct protolib *plib; 572 if (DICT_FIND_VAL(&cache->protolibs, &filename, &plib) == 0) 573 return plib; 574 } 575 576 FILE *stream = fopen(filename, "r"); 577 if (stream == NULL) 578 return NULL; 579 580 if (strdup_if(&filename, filename, !own_filename) < 0) { 581 fprintf(stderr, "Couldn't cache %s: %s\n", 582 filename, strerror(errno)); 583 fclose(stream); 584 return NULL; 585 } 586 587 struct protolib *new_plib = build_default_config(cache, filename); 588 if (new_plib == NULL 589 || read_config_file(stream, filename, new_plib) < 0) { 590 fclose(stream); 591 if (own_filename) 592 free((char *)filename); 593 if (new_plib != NULL) { 594 protolib_destroy(new_plib); 595 free(new_plib); 596 } 597 return NULL; 598 } 599 600 attempt_to_cache(cache, filename, new_plib); 601 fclose(stream); 602 return new_plib; 603} 604 605int 606protolib_cache_protolib(struct protolib_cache *cache, 607 const char *filename, int own_filename, 608 struct protolib *plib) 609{ 610 if (strdup_if(&filename, filename, !own_filename) < 0) { 611 fprintf(stderr, "Couldn't cache %s: %s\n", 612 filename, strerror(errno)); 613 return -1; 614 } 615 616 int rc = DICT_INSERT(&cache->protolibs, &filename, &plib); 617 if (rc < 0 && own_filename) 618 free((char *)filename); 619 if (rc == 0 && plib != NULL) 620 plib->refs++; 621 return rc; 622} 623 624static void 625destroy_global_config(void) 626{ 627 protolib_cache_destroy(&g_protocache); 628 protolib_destroy(&legacy_typedefs); 629} 630 631void 632init_global_config(void) 633{ 634 protolib_init(&legacy_typedefs); 635 struct arg_type_info *void_info = type_get_simple(ARGTYPE_VOID); 636 static struct arg_type_info ptr_info; 637 type_init_pointer(&ptr_info, void_info, 0); 638 639 static struct named_type voidptr_type; 640 named_type_init(&voidptr_type, &ptr_info, 0); 641 642 /* Build legacy typedefs first. This is used by 643 * protolib_cache_init call below. */ 644 if (protolib_add_named_type(&legacy_typedefs, "addr", 0, 645 &voidptr_type) < 0 646 || protolib_add_named_type(&legacy_typedefs, "file", 0, 647 &voidptr_type) < 0) { 648 fprintf(stderr, 649 "Couldn't initialize aliases `addr' and `file'.\n"); 650 651 exit(1); 652 } 653 654 if (protolib_cache_init(&g_protocache, NULL) < 0) { 655 fprintf(stderr, "Couldn't init prototype cache\n"); 656 exit(1); 657 } 658 659 atexit(destroy_global_config); 660} 661