loader.c

   1 /*
   2  * Asterisk -- A telephony toolkit for Linux.
   3  *
   4  * Module Loader
   5  *
   6  * Copyright (C) 1999-2004, Digium, Inc.
   7  *
   8  * Mark Spencer <markster@digium.com>
   9  *
  10  * This program is free software, distributed under the terms of
  11  * the GNU General Public License
  12  */
  13
  14 #include <stdio.h>
  15 #include <dirent.h>
  16 #include <unistd.h>
  17 #include <stdlib.h>
  18 #include <string.h>
  19 #include <asterisk/module.h>
  20 #include <asterisk/options.h>
  21 #include <asterisk/config.h>
  22 #include <asterisk/config_pvt.h>
  23 #include <asterisk/logger.h>
  24 #include <asterisk/channel.h>
  25 #include <asterisk/term.h>
  26 #include <asterisk/manager.h>
  27 #include <asterisk/enum.h>
  28 #include <asterisk/rtp.h>
  29 #include <asterisk/lock.h>
  30 #ifdef __APPLE__
  31 #include <asterisk/dlfcn-compat.h>
  32 #else
  33 #include <dlfcn.h>
  34 #endif
  35 #include <asterisk/md5.h>
  36 #include "asterisk.h"
  37 #include "astconf.h"
  38
  39 #ifndef RTLD_NOW
  40 #define RTLD_NOW 0
  41 #endif
  42
  43 static char expected_key[] =
  44 { 0x8e, 0x93, 0x22, 0x83, 0xf5, 0xc3, 0xc0, 0x75,
  45   0xff, 0x8b, 0xa9, 0xbe, 0x7c, 0x43, 0x74, 0x63 };
  46
  47 struct module {
  48         int (*load_module)(void);
  49         int (*unload_module)(void);
  50         int (*usecount)(void);
  51         char *(*description)(void);
  52         char *(*key)(void);
  53         int (*reload)(void);
  54         void *lib;
  55         char resource[256];
  56         struct module *next;
  57 };
  58
  59 static int printdigest(unsigned char *d)
  60 {
  61         int x;
  62         char buf[256];
  63         char buf2[16];
  64         snprintf(buf, sizeof(buf), "Unexpected signature:");
  65         for (x=0;x<16;x++) {
  66                 snprintf(buf2, sizeof(buf2), " %02x", *(d++));
  67                 strcat(buf, buf2);
  68         }
  69         strcat(buf, "\n");
  70         ast_log(LOG_DEBUG, buf);
  71         return 0;
  72 }
  73
  74 static int key_matches(char *key1, char *key2)
  75 {
  76         int match = 1;
  77         int x;
  78         for (x=0;x<16;x++) {
  79                 match &= (key1[x] == key2[x]);
  80         }
  81         return match;
  82 }
  83
  84 static int verify_key(char *key)
  85 {
  86         struct MD5Context c;
  87         char digest[16];
  88         MD5Init(&c);
  89         MD5Update(&c, key, strlen(key));
  90         MD5Final(digest, &c);
  91         if (key_matches(expected_key, digest))
  92                 return 0;
  93         printdigest(digest);
  94         return -1;
  95 }
  96
  97 static struct loadupdate {
  98         int (*updater)(void);
  99         struct loadupdate *next;
 100 } *updaters = NULL;
 101
 102 AST_MUTEX_DEFINE_STATIC(modlock);
 103 AST_MUTEX_DEFINE_STATIC(reloadlock);
 104
 105 static struct module *module_list=NULL;
 106 static int modlistver = 0;
 107
 108 int ast_unload_resource(char *resource_name, int force)
 109 {
 110         struct module *m, *ml = NULL;
 111         int res = -1;
 112         if (ast_mutex_lock(&modlock))
 113                 ast_log(LOG_WARNING, "Failed to lock\n");
 114         m = module_list;
 115         while(m) {
 116                 if (!strcasecmp(m->resource, resource_name)) {
 117                         if ((res = m->usecount()) > 0)  {
 118                                 if (force)
 119                                         ast_log(LOG_WARNING, "Warning:  Forcing removal of module %s with use count %d\n", resource_name, res);
 120                                 else {
 121                                         ast_log(LOG_WARNING, "Soft unload failed, '%s' has use count %d\n", resource_name, res);
 122                                         ast_mutex_unlock(&modlock);
 123                                         return -1;
 124                                 }
 125                         }
 126                         res = m->unload_module();
 127                         if (res) {
 128                                 ast_log(LOG_WARNING, "Firm unload failed for %s\n", resource_name);
 129                                 if (force <= AST_FORCE_FIRM) {
 130                                         ast_mutex_unlock(&modlock);
 131                                         return -1;
 132                                 } else
 133                                         ast_log(LOG_WARNING, "** Dangerous **: Unloading resource anyway, at user request\n");
 134                         }
 135                         if (ml)
 136                                 ml->next = m->next;
 137                         else
 138                                 module_list = m->next;
 139                         dlclose(m->lib);
 140                         free(m);
 141                         break;
 142                 }
 143                 ml = m;
 144                 m = m->next;
 145         }
 146         modlistver = rand();
 147         ast_mutex_unlock(&modlock);
 148         ast_update_use_count();
 149         return res;
 150 }
 151
 152 char *ast_module_helper(char *line, char *word, int pos, int state, int rpos, int needsreload)
 153 {
 154         struct module *m;
 155         int which=0;
 156         char *ret;
 157         if (pos != rpos)
 158                 return NULL;
 159         ast_mutex_lock(&modlock);
 160         m = module_list;
 161         while(m) {
 162                 if (!strncasecmp(word, m->resource, strlen(word)) && (m->reload || !needsreload)) {
 163                         if (++which > state)
 164                                 break;
 165                 }
 166                 m = m->next;
 167         }
 168         if (m) {
 169                 ret = strdup(m->resource);
 170         } else {
 171                 ret = NULL;
 172                 if (!strncasecmp(word, "astconfig", strlen(word))) {
 173                         if (++which > state)
 174                                 ret = strdup("astconfig");
 175                 } else if (!strncasecmp(word, "manager", strlen(word))) {
 176                         if (++which > state)
 177                                 ret = strdup("manager");
 178                 } else if (!strncasecmp(word, "enum", strlen(word))) {
 179                         if (++which > state)
 180                                 ret = strdup("enum");
 181                 } else if (!strncasecmp(word, "rtp", strlen(word))) {
 182                         if (++which > state)
 183                                 ret = strdup("rtp");
 184                 }
 185
 186         }
 187         ast_mutex_unlock(&modlock);
 188         return ret;
 189 }
 190
 191 int ast_module_reload(const char *name)
 192 {
 193         struct module *m;
 194         int reloaded = 0;
 195         int oldversion;
 196         int (*reload)(void);
 197         /* We'll do the logger and manager the favor of calling its reload here first */
 198
 199         if (ast_mutex_trylock(&reloadlock)) {
 200                 ast_verbose("The previous reload command didn't finish yet\n");
 201                 return -1;
 202         }
 203         if (!name || !strcasecmp(name, "astconfig")) {
 204                 read_ast_cust_config();
 205                 reloaded = 2;
 206         }
 207         if (!name || !strcasecmp(name, "manager")) {
 208                 reload_manager();
 209                 reloaded = 2;
 210         }
 211         if (!name || !strcasecmp(name, "enum")) {
 212                 ast_enum_reload();
 213                 reloaded = 2;
 214         }
 215         if (!name || !strcasecmp(name, "rtp")) {
 216                 ast_rtp_reload();
 217                 reloaded = 2;
 218         }
 219         time(&ast_lastreloadtime);
 220
 221         ast_mutex_lock(&modlock);
 222         oldversion = modlistver;
 223         m = module_list;
 224         while(m) {
 225                 if (!name || !strcasecmp(name, m->resource)) {
 226                         if (reloaded < 1)
 227                                 reloaded = 1;
 228                         reload = m->reload;
 229                         ast_mutex_unlock(&modlock);
 230                         if (reload) {
 231                                 reloaded = 2;
 232                                 if (option_verbose > 2)
 233                                         ast_verbose(VERBOSE_PREFIX_3 "Reloading module '%s' (%s)\n", m->resource, m->description());
 234                                 reload();
 235                         }
 236                         ast_mutex_lock(&modlock);
 237                         if (oldversion != modlistver)
 238                                 break;
 239                 }
 240                 m = m->next;
 241         }
 242         ast_mutex_unlock(&modlock);
 243         ast_mutex_unlock(&reloadlock);
 244         return reloaded;
 245 }
 246
 247 int ast_load_resource(char *resource_name)
 248 {
 249         static char fn[256];
 250         int errors=0;
 251         int res;
 252         struct module *m;
 253         int flags=RTLD_NOW;
 254 #ifdef RTLD_GLOBAL
 255         char *val;
 256 #endif
 257         char *key;
 258         int o;
 259         struct ast_config *cfg;
 260         char tmp[80];
 261         /* Keep the module file parsing silent */
 262         o = option_verbose;
 263         if (strncasecmp(resource_name, "res_", 4)) {
 264                 option_verbose = 0;
 265                 cfg = ast_load(AST_MODULE_CONFIG);
 266                 option_verbose = o;
 267                 if (cfg) {
 268 #ifdef RTLD_GLOBAL
 269                         if ((val = ast_variable_retrieve(cfg, "global", resource_name))
 270                                         && ast_true(val))
 271                                 flags |= RTLD_GLOBAL;
 272 #endif
 273                         ast_destroy(cfg);
 274                 }
 275         } else {
 276                 /* Resource modules are always loaded global and lazy */
 277 #ifdef RTLD_GLOBAL
 278                 flags = (RTLD_GLOBAL | RTLD_LAZY);
 279 #else
 280                 flags = RTLD_LAZY;
 281 #endif
 282         }
 283
 284         if (ast_mutex_lock(&modlock))
 285                 ast_log(LOG_WARNING, "Failed to lock\n");
 286         m = module_list;
 287         while(m) {
 288                 if (!strcasecmp(m->resource, resource_name)) {
 289                         ast_log(LOG_WARNING, "Module '%s' already exists\n", resource_name);
 290                         ast_mutex_unlock(&modlock);
 291                         return -1;
 292                 }
 293                 m = m->next;
 294         }
 295         m = malloc(sizeof(struct module));
 296         if (!m) {
 297                 ast_log(LOG_WARNING, "Out of memory\n");
 298                 ast_mutex_unlock(&modlock);
 299                 return -1;
 300         }
 301         strncpy(m->resource, resource_name, sizeof(m->resource)-1);
 302         if (resource_name[0] == '/') {
 303                 strncpy(fn, resource_name, sizeof(fn)-1);
 304         } else {
 305                 snprintf(fn, sizeof(fn), "%s/%s", (char *)ast_config_AST_MODULE_DIR, resource_name);
 306         }
 307         m->lib = dlopen(fn, flags);
 308         if (!m->lib) {
 309                 ast_log(LOG_WARNING, "%s\n", dlerror());
 310                 free(m);
 311                 ast_mutex_unlock(&modlock);
 312                 return -1;
 313         }
 314         m->load_module = dlsym(m->lib, "load_module");
 315         if (m->load_module == NULL)
 316                 m->load_module = dlsym(m->lib, "_load_module");
 317         if (!m->load_module) {
 318                 ast_log(LOG_WARNING, "No load_module in module %s\n", fn);
 319                 errors++;
 320         }
 321         m->unload_module = dlsym(m->lib, "unload_module");
 322         if (m->unload_module == NULL)
 323                 m->unload_module = dlsym(m->lib, "_unload_module");
 324         if (!m->unload_module) {
 325                 ast_log(LOG_WARNING, "No unload_module in module %s\n", fn);
 326                 errors++;
 327         }
 328         m->usecount = dlsym(m->lib, "usecount");
 329         if (m->usecount == NULL)
 330                 m->usecount = dlsym(m->lib, "_usecount");
 331         if (!m->usecount) {
 332                 ast_log(LOG_WARNING, "No usecount in module %s\n", fn);
 333                 errors++;
 334         }
 335         m->description = dlsym(m->lib, "description");
 336         if (m->description == NULL)
 337                 m->description = dlsym(m->lib, "_description");
 338         if (!m->description) {
 339                 ast_log(LOG_WARNING, "No description in module %s\n", fn);
 340                 errors++;
 341         }
 342         m->key = dlsym(m->lib, "key");
 343         if (m->key == NULL)
 344                 m->key = dlsym(m->lib, "_key");
 345         if (!m->key) {
 346                 ast_log(LOG_WARNING, "No key routine in module %s\n", fn);
 347                 errors++;
 348         }
 349         m->reload = dlsym(m->lib, "reload");
 350         if (m->reload == NULL)
 351                 m->reload = dlsym(m->lib, "_reload");
 352         if (!m->key || !(key = m->key())) {
 353                 ast_log(LOG_WARNING, "Key routine returned NULL in module %s\n", fn);
 354                 key = NULL;
 355                 errors++;
 356         }
 357         if (key && verify_key(key)) {
 358                 ast_log(LOG_WARNING, "Unexpected key returned by module %s\n", fn);
 359                 errors++;
 360         }
 361         if (errors) {
 362                 ast_log(LOG_WARNING, "%d error(s) loading module %s, aborted\n", errors, fn);
 363                 dlclose(m->lib);
 364                 free(m);
 365                 ast_mutex_unlock(&modlock);
 366                 return -1;
 367         }
 368         if (!fully_booted) {
 369                 if (option_verbose)
 370                         ast_verbose( " => (%s)\n", term_color(tmp, m->description(), COLOR_BROWN, COLOR_BLACK, sizeof(tmp)));
 371                 if (option_console && !option_verbose)
 372                         ast_verbose( ".");
 373         } else {
 374                 if (option_verbose)
 375                         ast_verbose(VERBOSE_PREFIX_1 "Loaded %s => (%s)\n", fn, m->description());
 376         }
 377
 378         /* add module 'm' to end of module_list chain
 379            so reload commands will be issued in same order modules were loaded */
 380         m->next = NULL;
 381         if (module_list == NULL) {
 382                 /* empty list so far, add at front */
 383                 module_list = m;
 384         }
 385         else {
 386                 struct module *i;
 387                 /* find end of chain, and add there */
 388                 for (i = module_list; i->next; i = i->next)
 389                         ;
 390                 i->next = m;
 391         }
 392
 393         modlistver = rand();
 394         ast_mutex_unlock(&modlock);
 395         if ((res = m->load_module())) {
 396                 ast_log(LOG_WARNING, "%s: load_module failed, returning %d\n", m->resource, res);
 397                 ast_unload_resource(resource_name, 0);
 398                 return -1;
 399         }
 400         ast_update_use_count();
 401         return 0;
 402 }
 403
 404 static int ast_resource_exists(char *resource)
 405 {
 406         struct module *m;
 407         if (ast_mutex_lock(&modlock))
 408                 ast_log(LOG_WARNING, "Failed to lock\n");
 409         m = module_list;
 410         while(m) {
 411                 if (!strcasecmp(resource, m->resource))
 412                         break;
 413                 m = m->next;
 414         }
 415         ast_mutex_unlock(&modlock);
 416         if (m)
 417                 return -1;
 418         else
 419                 return 0;
 420 }
 421
 422 static const char *loadorder[] =
 423 {
 424         "res_",
 425         "chan_",
 426         "pbx_",
 427         NULL,
 428 };
 429
 430 int load_modules()
 431 {
 432         struct ast_config *cfg;
 433         struct ast_variable *v;
 434         char tmp[80];
 435         if (option_verbose)
 436                 ast_verbose( "Asterisk Dynamic Loader Starting:\n");
 437         cfg = ast_load(AST_MODULE_CONFIG);
 438         if (cfg) {
 439                 /* Load explicitly defined modules */
 440                 v = ast_variable_browse(cfg, "modules");
 441                 while(v) {
 442                         if (!strcasecmp(v->name, "load")) {
 443                                 if (option_debug && !option_verbose)
 444                                         ast_log(LOG_DEBUG, "Loading module %s\n", v->value);
 445                                 if (option_verbose) {
 446                                         ast_verbose( VERBOSE_PREFIX_1 "[%s]", term_color(tmp, v->value, COLOR_BRWHITE, 0, sizeof(tmp)));
 447                                         fflush(stdout);
 448                                 }
 449                                 if (ast_load_resource(v->value)) {
 450                                         ast_log(LOG_WARNING, "Loading module %s failed!\n", v->value);
 451                                         if (cfg)
 452                                                 ast_destroy(cfg);
 453                                         return -1;
 454                                 }
 455                         }
 456                         v=v->next;
 457                 }
 458         }
 459         if (!cfg || ast_true(ast_variable_retrieve(cfg, "modules", "autoload"))) {
 460                 /* Load all modules */
 461                 DIR *mods;
 462                 struct dirent *d;
 463                 int x;
 464                 /* Loop through each order */
 465                 for (x=0;x<sizeof(loadorder) / sizeof(loadorder[0]);x++) {
 466                         mods = opendir((char *)ast_config_AST_MODULE_DIR);
 467                         if (mods) {
 468                                 while((d = readdir(mods))) {
 469                                         /* Must end in .so to load it.  */
 470                                         if ((strlen(d->d_name) > 3) &&
 471                                             (!loadorder[x] || !strncasecmp(d->d_name, loadorder[x], strlen(loadorder[x]))) &&
 472                                             !strcasecmp(d->d_name + strlen(d->d_name) - 3, ".so") &&
 473                                                 !ast_resource_exists(d->d_name)) {
 474                                                 /* It's a shared library -- Just be sure we're allowed to load it -- kinda
 475                                                    an inefficient way to do it, but oh well. */
 476                                                 if (cfg) {
 477                                                         v = ast_variable_browse(cfg, "modules");
 478                                                         while(v) {
 479                                                                 if (!strcasecmp(v->name, "noload") &&
 480                                                                     !strcasecmp(v->value, d->d_name))
 481                                                                         break;
 482                                                                 v = v->next;
 483                                                         }
 484                                                         if (v) {
 485                                                                 if (option_verbose) {
 486                                                                         ast_verbose( VERBOSE_PREFIX_1 "[skipping %s]\n", d->d_name);
 487                                                                         fflush(stdout);
 488                                                                 }
 489                                                                 continue;
 490                                                         }
 491
 492                                                 }
 493                                             if (option_debug && !option_verbose)
 494                                                         ast_log(LOG_DEBUG, "Loading module %s\n", d->d_name);
 495                                                 if (option_verbose) {
 496                                                         ast_verbose( VERBOSE_PREFIX_1 "[%s]", term_color(tmp, d->d_name, COLOR_BRWHITE, 0, sizeof(tmp)));
 497                                                         fflush(stdout);
 498                                                 }
 499                                                 if (ast_load_resource(d->d_name)) {
 500                                                         ast_log(LOG_WARNING, "Loading module %s failed!\n", d->d_name);
 501                                                         if (cfg)
 502                                                                 ast_destroy(cfg);
 503                                                         return -1;
 504                                                 }
 505                                         }
 506                                 }
 507                                 closedir(mods);
 508                         } else {
 509                                 if (!option_quiet)
 510                                         ast_log(LOG_WARNING, "Unable to open modules directory %s.\n", (char *)ast_config_AST_MODULE_DIR);
 511                         }
 512                 }
 513         }
 514         ast_destroy(cfg);
 515         return 0;
 516 }
 517
 518 void ast_update_use_count(void)
 519 {
 520         /* Notify any module monitors that the use count for a
 521            resource has changed */
 522         struct loadupdate *m;
 523         if (ast_mutex_lock(&modlock))
 524                 ast_log(LOG_WARNING, "Failed to lock\n");
 525         m = updaters;
 526         while(m) {
 527                 m->updater();
 528                 m = m->next;
 529         }
 530         ast_mutex_unlock(&modlock);
 531
 532 }
 533
 534 int ast_update_module_list(int (*modentry)(char *module, char *description, int usecnt, char *like), char *like)
 535 {
 536         struct module *m;
 537         int unlock = -1;
 538         int total_mod_loaded = 0;
 539         if (ast_mutex_trylock(&modlock))
 540                 unlock = 0;
 541         m = module_list;
 542         while(m) {
 543                 total_mod_loaded += modentry(m->resource, m->description(), m->usecount(), like);
 544                 m = m->next;
 545         }
 546         if (unlock)
 547                 ast_mutex_unlock(&modlock);
 548         return total_mod_loaded;
 549 }
 550
 551 int ast_loader_register(int (*v)(void))
 552 {
 553         struct loadupdate *tmp;
 554         /* XXX Should be more flexible here, taking > 1 verboser XXX */
 555         if ((tmp = malloc(sizeof (struct loadupdate)))) {
 556                 tmp->updater = v;
 557                 if (ast_mutex_lock(&modlock))
 558                         ast_log(LOG_WARNING, "Failed to lock\n");
 559                 tmp->next = updaters;
 560                 updaters = tmp;
 561                 ast_mutex_unlock(&modlock);
 562                 return 0;
 563         }
 564         return -1;
 565 }
 566
 567 int ast_loader_unregister(int (*v)(void))
 568 {
 569         int res = -1;
 570         struct loadupdate *tmp, *tmpl=NULL;
 571         if (ast_mutex_lock(&modlock))
 572                 ast_log(LOG_WARNING, "Failed to lock\n");
 573         tmp = updaters;
 574         while(tmp) {
 575                 if (tmp->updater == v)  {
 576                         if (tmpl)
 577                                 tmpl->next = tmp->next;
 578                         else
 579                                 updaters = tmp->next;
 580                         break;
 581                 }
 582                 tmpl = tmp;
 583                 tmp = tmp->next;
 584         }
 585         if (tmp)
 586                 res = 0;
 587         ast_mutex_unlock(&modlock);
 588         return res;
 589 }