Fri Sep 25 19:28:12 2009

Asterisk developer's documentation


loader.c

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00001 /*
00002  * Asterisk -- An open source telephony toolkit.
00003  *
00004  * Copyright (C) 1999 - 2006, Digium, Inc.
00005  *
00006  * Mark Spencer <markster@digium.com>
00007  * Kevin P. Fleming <kpfleming@digium.com>
00008  * Luigi Rizzo <rizzo@icir.org>
00009  *
00010  * See http://www.asterisk.org for more information about
00011  * the Asterisk project. Please do not directly contact
00012  * any of the maintainers of this project for assistance;
00013  * the project provides a web site, mailing lists and IRC
00014  * channels for your use.
00015  *
00016  * This program is free software, distributed under the terms of
00017  * the GNU General Public License Version 2. See the LICENSE file
00018  * at the top of the source tree.
00019  */
00020 
00021 /*! \file
00022  *
00023  * \brief Module Loader
00024  * \author Mark Spencer <markster@digium.com>
00025  * \author Kevin P. Fleming <kpfleming@digium.com>
00026  * \author Luigi Rizzo <rizzo@icir.org>
00027  * - See ModMngMnt
00028  */
00029 
00030 #include "asterisk.h"
00031 
00032 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 91501 $")
00033 
00034 #include <stdio.h>
00035 #include <dirent.h>
00036 #include <unistd.h>
00037 #include <stdlib.h>
00038 #include <errno.h>
00039 #include <string.h>
00040 
00041 #include "asterisk/linkedlists.h"
00042 #include "asterisk/module.h"
00043 #include "asterisk/options.h"
00044 #include "asterisk/config.h"
00045 #include "asterisk/logger.h"
00046 #include "asterisk/channel.h"
00047 #include "asterisk/term.h"
00048 #include "asterisk/manager.h"
00049 #include "asterisk/cdr.h"
00050 #include "asterisk/enum.h"
00051 #include "asterisk/rtp.h"
00052 #include "asterisk/http.h"
00053 #include "asterisk/lock.h"
00054 
00055 #ifdef DLFCNCOMPAT
00056 #include "asterisk/dlfcn-compat.h"
00057 #else
00058 #include <dlfcn.h>
00059 #endif
00060 
00061 #include "asterisk/md5.h"
00062 #include "asterisk/utils.h"
00063 
00064 #ifndef RTLD_NOW
00065 #define RTLD_NOW 0
00066 #endif
00067 
00068 struct ast_module_user {
00069    struct ast_channel *chan;
00070    AST_LIST_ENTRY(ast_module_user) entry;
00071 };
00072 
00073 AST_LIST_HEAD(module_user_list, ast_module_user);
00074 
00075 static unsigned char expected_key[] =
00076 { 0x87, 0x76, 0x79, 0x35, 0x23, 0xea, 0x3a, 0xd3,
00077   0x25, 0x2a, 0xbb, 0x35, 0x87, 0xe4, 0x22, 0x24 };
00078 
00079 static char buildopt_sum[33] = AST_BUILDOPT_SUM;
00080 
00081 static unsigned int embedding = 1; /* we always start out by registering embedded modules,
00082                   since they are here before we dlopen() any
00083                */
00084 
00085 struct ast_module {
00086    const struct ast_module_info *info;
00087    void *lib;              /* the shared lib, or NULL if embedded */
00088    int usecount;              /* the number of 'users' currently in this module */
00089    struct module_user_list users;         /* the list of users in the module */
00090    struct {
00091       unsigned int running:1;
00092       unsigned int declined:1;
00093    } flags;
00094    AST_LIST_ENTRY(ast_module) entry;
00095    char resource[0];
00096 };
00097 
00098 static AST_LIST_HEAD_STATIC(module_list, ast_module);
00099 
00100 struct loadupdate {
00101    int (*updater)(void);
00102    AST_LIST_ENTRY(loadupdate) entry;
00103 };
00104 
00105 static AST_LIST_HEAD_STATIC(updaters, loadupdate);
00106 
00107 AST_MUTEX_DEFINE_STATIC(reloadlock);
00108 
00109 /* when dynamic modules are being loaded, ast_module_register() will
00110    need to know what filename the module was loaded from while it
00111    is being registered
00112 */
00113 struct ast_module *resource_being_loaded;
00114 
00115 /* XXX: should we check for duplicate resource names here? */
00116 
00117 void ast_module_register(const struct ast_module_info *info)
00118 {
00119    struct ast_module *mod;
00120 
00121    if (embedding) {
00122       if (!(mod = ast_calloc(1, sizeof(*mod) + strlen(info->name) + 1)))
00123          return;
00124       strcpy(mod->resource, info->name);
00125    } else {
00126       mod = resource_being_loaded;
00127    }
00128 
00129    mod->info = info;
00130    AST_LIST_HEAD_INIT(&mod->users);
00131 
00132    /* during startup, before the loader has been initialized,
00133       there are no threads, so there is no need to take the lock
00134       on this list to manipulate it. it is also possible that it
00135       might be unsafe to use the list lock at that point... so
00136       let's avoid it altogether
00137    */
00138    if (!embedding)
00139       AST_LIST_LOCK(&module_list);
00140 
00141    /* it is paramount that the new entry be placed at the tail of
00142       the list, otherwise the code that uses dlopen() to load
00143       dynamic modules won't be able to find out if the module it
00144       just opened was registered or failed to load
00145    */
00146    AST_LIST_INSERT_TAIL(&module_list, mod, entry);
00147 
00148    if (!embedding)
00149       AST_LIST_UNLOCK(&module_list);
00150 
00151    /* give the module a copy of its own handle, for later use in registrations and the like */
00152    *((struct ast_module **) &(info->self)) = mod;
00153 }
00154 
00155 void ast_module_unregister(const struct ast_module_info *info)
00156 {
00157    struct ast_module *mod = NULL;
00158 
00159    /* it is assumed that the users list in the module structure
00160       will already be empty, or we cannot have gotten to this
00161       point
00162    */
00163    AST_LIST_LOCK(&module_list);
00164    AST_LIST_TRAVERSE_SAFE_BEGIN(&module_list, mod, entry) {
00165       if (mod->info == info) {
00166          AST_LIST_REMOVE_CURRENT(&module_list, entry);
00167          break;
00168       }
00169    }
00170    AST_LIST_TRAVERSE_SAFE_END;
00171    AST_LIST_UNLOCK(&module_list);
00172 
00173    if (mod) {
00174       AST_LIST_HEAD_DESTROY(&mod->users);
00175       free(mod);
00176    }
00177 }
00178 
00179 struct ast_module_user *__ast_module_user_add(struct ast_module *mod,
00180                      struct ast_channel *chan)
00181 {
00182    struct ast_module_user *u = ast_calloc(1, sizeof(*u));
00183 
00184    if (!u)
00185       return NULL;
00186 
00187    u->chan = chan;
00188 
00189    AST_LIST_LOCK(&mod->users);
00190    AST_LIST_INSERT_HEAD(&mod->users, u, entry);
00191    AST_LIST_UNLOCK(&mod->users);
00192 
00193    ast_atomic_fetchadd_int(&mod->usecount, +1);
00194 
00195    ast_update_use_count();
00196 
00197    return u;
00198 }
00199 
00200 void __ast_module_user_remove(struct ast_module *mod, struct ast_module_user *u)
00201 {
00202    AST_LIST_LOCK(&mod->users);
00203    AST_LIST_REMOVE(&mod->users, u, entry);
00204    AST_LIST_UNLOCK(&mod->users);
00205    ast_atomic_fetchadd_int(&mod->usecount, -1);
00206    free(u);
00207 
00208    ast_update_use_count();
00209 }
00210 
00211 void __ast_module_user_hangup_all(struct ast_module *mod)
00212 {
00213    struct ast_module_user *u;
00214 
00215    AST_LIST_LOCK(&mod->users);
00216    while ((u = AST_LIST_REMOVE_HEAD(&mod->users, entry))) {
00217       ast_softhangup(u->chan, AST_SOFTHANGUP_APPUNLOAD);
00218       ast_atomic_fetchadd_int(&mod->usecount, -1);
00219       free(u);
00220    }
00221    AST_LIST_UNLOCK(&mod->users);
00222 
00223         ast_update_use_count();
00224 }
00225 
00226 /*! \note
00227  * In addition to modules, the reload command handles some extra keywords
00228  * which are listed here together with the corresponding handlers.
00229  * This table is also used by the command completion code.
00230  */
00231 static struct reload_classes {
00232    const char *name;
00233    int (*reload_fn)(void);
00234 } reload_classes[] = {  /* list in alpha order, longest match first for cli completion */
00235    { "cdr", ast_cdr_engine_reload },
00236    { "dnsmgr", dnsmgr_reload },
00237    { "extconfig", read_config_maps },
00238    { "enum",   ast_enum_reload },
00239    { "manager",   reload_manager },
00240    { "rtp", ast_rtp_reload },
00241    { "http",   ast_http_reload },
00242    { "logger", logger_reload },
00243    { NULL,  NULL }
00244 };
00245 
00246 static int printdigest(const unsigned char *d)
00247 {
00248    int x, pos;
00249    char buf[256]; /* large enough so we don't have to worry */
00250 
00251    for (pos = 0, x = 0; x < 16; x++)
00252       pos += sprintf(buf + pos, " %02x", *d++);
00253 
00254    ast_log(LOG_DEBUG, "Unexpected signature:%s\n", buf);
00255 
00256    return 0;
00257 }
00258 
00259 static int key_matches(const unsigned char *key1, const unsigned char *key2)
00260 {
00261    int x;
00262 
00263    for (x = 0; x < 16; x++) {
00264       if (key1[x] != key2[x])
00265          return 0;
00266    }
00267 
00268    return 1;
00269 }
00270 
00271 static int verify_key(const unsigned char *key)
00272 {
00273    struct MD5Context c;
00274    unsigned char digest[16];
00275 
00276    MD5Init(&c);
00277    MD5Update(&c, key, strlen((char *)key));
00278    MD5Final(digest, &c);
00279 
00280    if (key_matches(expected_key, digest))
00281       return 0;
00282 
00283    printdigest(digest);
00284 
00285    return -1;
00286 }
00287 
00288 static int resource_name_match(const char *name1_in, const char *name2_in)
00289 {
00290    char *name1 = (char *) name1_in;
00291    char *name2 = (char *) name2_in;
00292 
00293    /* trim off any .so extensions */
00294    if (!strcasecmp(name1 + strlen(name1) - 3, ".so")) {
00295       name1 = ast_strdupa(name1);
00296       name1[strlen(name1) - 3] = '\0';
00297    }
00298    if (!strcasecmp(name2 + strlen(name2) - 3, ".so")) {
00299       name2 = ast_strdupa(name2);
00300       name2[strlen(name2) - 3] = '\0';
00301    }
00302 
00303    return strcasecmp(name1, name2);
00304 }
00305 
00306 static struct ast_module *find_resource(const char *resource, int do_lock)
00307 {
00308    struct ast_module *cur;
00309 
00310    if (do_lock)
00311       AST_LIST_LOCK(&module_list);
00312 
00313    AST_LIST_TRAVERSE(&module_list, cur, entry) {
00314       if (!resource_name_match(resource, cur->resource))
00315          break;
00316    }
00317 
00318    if (do_lock)
00319       AST_LIST_UNLOCK(&module_list);
00320 
00321    return cur;
00322 }
00323 
00324 #ifdef LOADABLE_MODULES
00325 static void unload_dynamic_module(struct ast_module *mod)
00326 {
00327    void *lib = mod->lib;
00328 
00329    /* WARNING: the structure pointed to by mod is going to
00330       disappear when this operation succeeds, so we can't
00331       dereference it */
00332 
00333    if (lib)
00334       while (!dlclose(lib));
00335 }
00336 
00337 static struct ast_module *load_dynamic_module(const char *resource_in, unsigned int global_symbols_only)
00338 {
00339    char fn[256];
00340    void *lib;
00341    struct ast_module *mod;
00342    char *resource = (char *) resource_in;
00343    unsigned int wants_global;
00344 
00345    if (strcasecmp(resource + strlen(resource) - 3, ".so")) {
00346       resource = alloca(strlen(resource_in) + 3);
00347            strcpy(resource, resource_in);
00348       strcat(resource, ".so");
00349    }
00350 
00351    snprintf(fn, sizeof(fn), "%s/%s", ast_config_AST_MODULE_DIR, resource);
00352 
00353    /* make a first load of the module in 'quiet' mode... don't try to resolve
00354       any symbols, and don't export any symbols. this will allow us to peek into
00355       the module's info block (if available) to see what flags it has set */
00356 
00357    if (!(resource_being_loaded = ast_calloc(1, sizeof(*resource_being_loaded) + strlen(resource) + 1)))
00358       return NULL;
00359 
00360    strcpy(resource_being_loaded->resource, resource);
00361 
00362    /* libopenh323 is buggy and segfaults on dlclose() when opened with
00363     * RTLD_LAZY. Workaround this until it gets fixed */
00364    if (!strcasecmp(resource, "chan_h323.so") ||
00365        !strcasecmp(resource, "chan_oh323.so"))
00366       lib = dlopen(fn, RTLD_NOW | RTLD_LOCAL);
00367 
00368    if (!(lib = dlopen(fn, RTLD_LAZY | RTLD_LOCAL))) {
00369       ast_log(LOG_WARNING, "Error loading module '%s': %s\n", resource_in, dlerror());
00370       free(resource_being_loaded);
00371       return NULL;
00372    }
00373 
00374    /* the dlopen() succeeded, let's find out if the module
00375       registered itself */
00376    /* note that this will only work properly as long as
00377       ast_module_register() (which is called by the module's
00378       constructor) places the new module at the tail of the
00379       module_list
00380    */
00381    if (resource_being_loaded != (mod = AST_LIST_LAST(&module_list))) {
00382       ast_log(LOG_WARNING, "Module '%s' did not register itself during load\n", resource_in);
00383       /* no, it did not, so close it and return */
00384       while (!dlclose(lib));
00385       /* note that the module's destructor will call ast_module_unregister(),
00386          which will free the structure we allocated in resource_being_loaded */
00387       return NULL;
00388    }
00389 
00390    wants_global = ast_test_flag(mod->info, AST_MODFLAG_GLOBAL_SYMBOLS);
00391 
00392    /* if we are being asked only to load modules that provide global symbols,
00393       and this one does not, then close it and return */
00394    if (global_symbols_only && !wants_global) {
00395       while (!dlclose(lib));
00396       return NULL;
00397    }
00398 
00399    /* if the system supports RTLD_NOLOAD, we can just 'promote' the flags
00400       on the already-opened library to what we want... if not, we have to
00401       close it and start over
00402    */
00403 #if defined(HAVE_RTLD_NOLOAD) && !defined(__Darwin__)
00404    if (!dlopen(fn, RTLD_NOLOAD | (wants_global ? RTLD_LAZY | RTLD_GLOBAL : RTLD_NOW | RTLD_LOCAL))) {
00405       ast_log(LOG_WARNING, "Unable to promote flags on module '%s': %s\n", resource_in, dlerror());
00406       while (!dlclose(lib));
00407       free(resource_being_loaded);
00408       return NULL;
00409    }
00410 #else
00411    while (!dlclose(lib));
00412    resource_being_loaded = NULL;
00413 
00414    /* start the load process again */
00415 
00416    if (!(resource_being_loaded = ast_calloc(1, sizeof(*resource_being_loaded) + strlen(resource) + 1)))
00417       return NULL;
00418 
00419    strcpy(resource_being_loaded->resource, resource);
00420 
00421    if (!(lib = dlopen(fn, wants_global ? RTLD_LAZY | RTLD_GLOBAL : RTLD_NOW | RTLD_LOCAL))) {
00422       ast_log(LOG_WARNING, "Error loading module '%s': %s\n", resource_in, dlerror());
00423       free(resource_being_loaded);
00424       return NULL;
00425    }
00426 
00427    /* since the module was successfully opened, and it registered itself
00428       the previous time we did that, we're going to assume it worked this
00429       time too :) */
00430 #endif
00431 
00432    AST_LIST_LAST(&module_list)->lib = lib;
00433    resource_being_loaded = NULL;
00434 
00435    return AST_LIST_LAST(&module_list);
00436 }
00437 #endif
00438 
00439 void ast_module_shutdown(void)
00440 {
00441    struct ast_module *mod;
00442    AST_LIST_HEAD_NOLOCK_STATIC(local_module_list, ast_module);
00443 
00444    /* We have to call the unload() callbacks in reverse order that the modules
00445     * exist in the module list so it is the reverse order of how they were
00446     * loaded. */
00447 
00448    AST_LIST_LOCK(&module_list);
00449    while ((mod = AST_LIST_REMOVE_HEAD(&module_list, entry)))
00450       AST_LIST_INSERT_HEAD(&local_module_list, mod, entry);
00451    AST_LIST_UNLOCK(&module_list);
00452 
00453    while ((mod = AST_LIST_REMOVE_HEAD(&local_module_list, entry))) {
00454       if (mod->info->unload)
00455          mod->info->unload();
00456       /* Since this should only be called when shutting down "gracefully",
00457        * all channels should be down before we get to this point, meaning
00458        * there will be no module users left. */
00459       AST_LIST_HEAD_DESTROY(&mod->users);
00460       free(mod);
00461    }
00462 }
00463 
00464 int ast_unload_resource(const char *resource_name, enum ast_module_unload_mode force)
00465 {
00466    struct ast_module *mod;
00467    int res = -1;
00468    int error = 0;
00469 
00470    AST_LIST_LOCK(&module_list);
00471 
00472    if (!(mod = find_resource(resource_name, 0))) {
00473       AST_LIST_UNLOCK(&module_list);
00474       return 0;
00475    }
00476 
00477    if (!(mod->flags.running || mod->flags.declined))
00478       error = 1;
00479 
00480    if (!mod->lib) {
00481       ast_log(LOG_WARNING, "Unloading embedded modules is not supported.\n");
00482       error = 1;
00483    }
00484 
00485    if (!error && (mod->usecount > 0)) {
00486       if (force)
00487          ast_log(LOG_WARNING, "Warning:  Forcing removal of module '%s' with use count %d\n",
00488             resource_name, mod->usecount);
00489       else {
00490          ast_log(LOG_WARNING, "Soft unload failed, '%s' has use count %d\n", resource_name,
00491             mod->usecount);
00492          error = 1;
00493       }
00494    }
00495 
00496    if (!error) {
00497       __ast_module_user_hangup_all(mod);
00498       res = mod->info->unload();
00499 
00500       if (res) {
00501          ast_log(LOG_WARNING, "Firm unload failed for %s\n", resource_name);
00502          if (force <= AST_FORCE_FIRM)
00503             error = 1;
00504          else
00505             ast_log(LOG_WARNING, "** Dangerous **: Unloading resource anyway, at user request\n");
00506       }
00507    }
00508 
00509    if (!error)
00510       mod->flags.running = mod->flags.declined = 0;
00511 
00512    AST_LIST_UNLOCK(&module_list);
00513 
00514 #ifdef LOADABLE_MODULES
00515    if (!error)
00516       unload_dynamic_module(mod);
00517 #endif
00518 
00519    if (!error)
00520       ast_update_use_count();
00521 
00522    return res;
00523 }
00524 
00525 char *ast_module_helper(const char *line, const char *word, int pos, int state, int rpos, int needsreload)
00526 {
00527    struct ast_module *cur;
00528    int i, which=0, l = strlen(word);
00529    char *ret = NULL;
00530 
00531    if (pos != rpos)
00532       return NULL;
00533 
00534    AST_LIST_LOCK(&module_list);
00535    AST_LIST_TRAVERSE(&module_list, cur, entry) {
00536       if (!strncasecmp(word, cur->resource, l) &&
00537           (cur->info->reload || !needsreload) &&
00538           ++which > state) {
00539          ret = strdup(cur->resource);
00540          break;
00541       }
00542    }
00543    AST_LIST_UNLOCK(&module_list);
00544 
00545    if (!ret) {
00546       for (i=0; !ret && reload_classes[i].name; i++) {
00547          if (!strncasecmp(word, reload_classes[i].name, l) && ++which > state)
00548             ret = strdup(reload_classes[i].name);
00549       }
00550    }
00551 
00552    return ret;
00553 }
00554 
00555 int ast_module_reload(const char *name)
00556 {
00557    struct ast_module *cur;
00558    int res = 0; /* return value. 0 = not found, others, see below */
00559    int i;
00560 
00561    if (ast_mutex_trylock(&reloadlock)) {
00562       ast_verbose("The previous reload command didn't finish yet\n");
00563       return -1;  /* reload already in progress */
00564    }
00565    ast_lastreloadtime = time(NULL);
00566 
00567    /* Call "predefined" reload here first */
00568    for (i = 0; reload_classes[i].name; i++) {
00569       if (!name || !strcasecmp(name, reload_classes[i].name)) {
00570          reload_classes[i].reload_fn();   /* XXX should check error ? */
00571          res = 2; /* found and reloaded */
00572       }
00573    }
00574 
00575    if (name && res) {
00576       ast_mutex_unlock(&reloadlock);
00577       return res;
00578    }
00579 
00580    AST_LIST_LOCK(&module_list);
00581    AST_LIST_TRAVERSE(&module_list, cur, entry) {
00582       const struct ast_module_info *info = cur->info;
00583 
00584       if (name && resource_name_match(name, cur->resource))
00585          continue;
00586 
00587       if (!(cur->flags.running || cur->flags.declined))
00588          continue;
00589 
00590       if (!info->reload) { /* cannot be reloaded */
00591          if (res < 1)   /* store result if possible */
00592             res = 1; /* 1 = no reload() method */
00593          continue;
00594       }
00595 
00596       res = 2;
00597       if (option_verbose > 2)
00598          ast_verbose(VERBOSE_PREFIX_3 "Reloading module '%s' (%s)\n", cur->resource, info->description);
00599       info->reload();
00600    }
00601    AST_LIST_UNLOCK(&module_list);
00602 
00603    ast_mutex_unlock(&reloadlock);
00604 
00605    return res;
00606 }
00607 
00608 static unsigned int inspect_module(const struct ast_module *mod)
00609 {
00610    if (!mod->info->description) {
00611       ast_log(LOG_WARNING, "Module '%s' does not provide a description.\n", mod->resource);
00612       return 1;
00613    }
00614 
00615    if (!mod->info->key) {
00616       ast_log(LOG_WARNING, "Module '%s' does not provide a license key.\n", mod->resource);
00617       return 1;
00618    }
00619 
00620    if (verify_key((unsigned char *) mod->info->key)) {
00621       ast_log(LOG_WARNING, "Module '%s' did not provide a valid license key.\n", mod->resource);
00622       return 1;
00623    }
00624 
00625    if (!ast_test_flag(mod->info, AST_MODFLAG_BUILDSUM)) {
00626       /*
00627       ast_log(LOG_WARNING, "Module '%s' was not compiled against a recent version of Asterisk and may cause instability.\n", mod->resource);
00628       */
00629    } else if (!ast_strlen_zero(mod->info->buildopt_sum) &&
00630          strcmp(buildopt_sum, mod->info->buildopt_sum)) {
00631       ast_log(LOG_WARNING, "Module '%s' was not compiled with the same compile-time options as this version of Asterisk.\n", mod->resource);
00632       ast_log(LOG_WARNING, "Module '%s' will not be initialized as it may cause instability.\n", mod->resource);
00633       return 1;
00634    }
00635 
00636    return 0;
00637 }
00638 
00639 static enum ast_module_load_result load_resource(const char *resource_name, unsigned int global_symbols_only)
00640 {
00641    struct ast_module *mod;
00642    enum ast_module_load_result res = AST_MODULE_LOAD_SUCCESS;
00643    char tmp[256];
00644 
00645    if ((mod = find_resource(resource_name, 0))) {
00646       if (mod->flags.running) {
00647          ast_log(LOG_WARNING, "Module '%s' already exists.\n", resource_name);
00648          return AST_MODULE_LOAD_DECLINE;
00649       }
00650       if (global_symbols_only && !ast_test_flag(mod->info, AST_MODFLAG_GLOBAL_SYMBOLS))
00651          return AST_MODULE_LOAD_SKIP;
00652    } else {
00653 #ifdef LOADABLE_MODULES
00654       if (!(mod = load_dynamic_module(resource_name, global_symbols_only))) {
00655          /* don't generate a warning message during load_modules() */
00656          if (!global_symbols_only) {
00657             ast_log(LOG_WARNING, "Module '%s' could not be loaded.\n", resource_name);
00658             return AST_MODULE_LOAD_DECLINE;
00659          } else {
00660             return AST_MODULE_LOAD_SKIP;
00661          }
00662       }
00663 #else
00664       ast_log(LOG_WARNING, "Module '%s' could not be loaded.\n", resource_name);
00665       return AST_MODULE_LOAD_DECLINE;
00666 #endif
00667    }
00668 
00669    if (inspect_module(mod)) {
00670       ast_log(LOG_WARNING, "Module '%s' could not be loaded.\n", resource_name);
00671 #ifdef LOADABLE_MODULES
00672       unload_dynamic_module(mod);
00673 #endif
00674       return AST_MODULE_LOAD_DECLINE;
00675    }
00676 
00677    mod->flags.declined = 0;
00678 
00679    if (mod->info->load)
00680       res = mod->info->load();
00681 
00682    switch (res) {
00683    case AST_MODULE_LOAD_SUCCESS:
00684       if (!ast_fully_booted) {
00685          if (option_verbose)
00686             ast_verbose("%s => (%s)\n", resource_name, term_color(tmp, mod->info->description, COLOR_BROWN, COLOR_BLACK, sizeof(tmp)));
00687          if (ast_opt_console && !option_verbose)
00688             ast_verbose( ".");
00689       } else {
00690          if (option_verbose)
00691             ast_verbose(VERBOSE_PREFIX_1 "Loaded %s => (%s)\n", resource_name, mod->info->description);
00692       }
00693 
00694       mod->flags.running = 1;
00695 
00696       ast_update_use_count();
00697       break;
00698    case AST_MODULE_LOAD_DECLINE:
00699       mod->flags.declined = 1;
00700       break;
00701    case AST_MODULE_LOAD_FAILURE:
00702       break;
00703    case AST_MODULE_LOAD_SKIP:
00704       /* modules should never return this value */
00705       break;
00706    }
00707 
00708    return res;
00709 }
00710 
00711 int ast_load_resource(const char *resource_name)
00712 {
00713        AST_LIST_LOCK(&module_list);
00714        load_resource(resource_name, 0);
00715        AST_LIST_UNLOCK(&module_list);
00716 
00717        return 0;
00718 }
00719 
00720 struct load_order_entry {
00721    char *resource;
00722    AST_LIST_ENTRY(load_order_entry) entry;
00723 };
00724 
00725 AST_LIST_HEAD_NOLOCK(load_order, load_order_entry);
00726 
00727 static struct load_order_entry *add_to_load_order(const char *resource, struct load_order *load_order)
00728 {
00729    struct load_order_entry *order;
00730 
00731    AST_LIST_TRAVERSE(load_order, order, entry) {
00732       if (!resource_name_match(order->resource, resource))
00733          return NULL;
00734    }
00735 
00736    if (!(order = ast_calloc(1, sizeof(*order))))
00737       return NULL;
00738 
00739    order->resource = ast_strdup(resource);
00740    AST_LIST_INSERT_TAIL(load_order, order, entry);
00741 
00742    return order;
00743 }
00744 
00745 int load_modules(unsigned int preload_only)
00746 {
00747    struct ast_config *cfg;
00748    struct ast_module *mod;
00749    struct load_order_entry *order;
00750    struct ast_variable *v;
00751    unsigned int load_count;
00752    struct load_order load_order;
00753    int res = 0;
00754 #ifdef LOADABLE_MODULES
00755    struct dirent *dirent;
00756    DIR *dir;
00757 #endif
00758 
00759    /* all embedded modules have registered themselves by now */
00760    embedding = 0;
00761 
00762    if (option_verbose)
00763       ast_verbose("Asterisk Dynamic Loader Starting:\n");
00764 
00765    AST_LIST_HEAD_INIT_NOLOCK(&load_order);
00766 
00767    AST_LIST_LOCK(&module_list);
00768 
00769    if (!(cfg = ast_config_load(AST_MODULE_CONFIG))) {
00770       ast_log(LOG_WARNING, "No '%s' found, no modules will be loaded.\n", AST_MODULE_CONFIG);
00771       goto done;
00772    }
00773 
00774    /* first, find all the modules we have been explicitly requested to load */
00775    for (v = ast_variable_browse(cfg, "modules"); v; v = v->next) {
00776       if (!strcasecmp(v->name, preload_only ? "preload" : "load"))
00777          add_to_load_order(v->value, &load_order);
00778    }
00779 
00780    /* check if 'autoload' is on */
00781    if (!preload_only && ast_true(ast_variable_retrieve(cfg, "modules", "autoload"))) {
00782       /* if so, first add all the embedded modules that are not already running to the load order */
00783       AST_LIST_TRAVERSE(&module_list, mod, entry) {
00784          /* if it's not embedded, skip it */
00785          if (mod->lib)
00786             continue;
00787 
00788          if (mod->flags.running)
00789             continue;
00790 
00791          order = add_to_load_order(mod->resource, &load_order);
00792       }
00793 
00794 #ifdef LOADABLE_MODULES
00795       /* if we are allowed to load dynamic modules, scan the directory for
00796          for all available modules and add them as well */
00797       if ((dir  = opendir(ast_config_AST_MODULE_DIR))) {
00798          while ((dirent = readdir(dir))) {
00799             int ld = strlen(dirent->d_name);
00800 
00801             /* Must end in .so to load it.  */
00802 
00803             if (ld < 4)
00804                continue;
00805 
00806             if (strcasecmp(dirent->d_name + ld - 3, ".so"))
00807                continue;
00808 
00809             /* if there is already a module by this name in the module_list,
00810                skip this file */
00811             if (find_resource(dirent->d_name, 0))
00812                continue;
00813 
00814             add_to_load_order(dirent->d_name, &load_order);
00815          }
00816 
00817          closedir(dir);
00818       } else {
00819          if (!ast_opt_quiet)
00820             ast_log(LOG_WARNING, "Unable to open modules directory '%s'.\n",
00821                ast_config_AST_MODULE_DIR);
00822       }
00823 #endif
00824    }
00825 
00826    /* now scan the config for any modules we are prohibited from loading and
00827       remove them from the load order */
00828    for (v = ast_variable_browse(cfg, "modules"); v; v = v->next) {
00829       if (strcasecmp(v->name, "noload"))
00830          continue;
00831 
00832       AST_LIST_TRAVERSE_SAFE_BEGIN(&load_order, order, entry) {
00833          if (!resource_name_match(order->resource, v->value)) {
00834             AST_LIST_REMOVE_CURRENT(&load_order, entry);
00835             free(order->resource);
00836             free(order);
00837          }
00838       }
00839       AST_LIST_TRAVERSE_SAFE_END;
00840    }
00841 
00842    /* we are done with the config now, all the information we need is in the
00843       load_order list */
00844    ast_config_destroy(cfg);
00845 
00846    load_count = 0;
00847    AST_LIST_TRAVERSE(&load_order, order, entry)
00848       load_count++;
00849 
00850    if (load_count)
00851       ast_log(LOG_NOTICE, "%d modules will be loaded.\n", load_count);
00852 
00853    /* first, load only modules that provide global symbols */
00854    AST_LIST_TRAVERSE_SAFE_BEGIN(&load_order, order, entry) {
00855       switch (load_resource(order->resource, 1)) {
00856       case AST_MODULE_LOAD_SUCCESS:
00857       case AST_MODULE_LOAD_DECLINE:
00858          AST_LIST_REMOVE_CURRENT(&load_order, entry);
00859          free(order->resource);
00860          free(order);
00861          break;
00862       case AST_MODULE_LOAD_FAILURE:
00863          res = -1;
00864          goto done;
00865       case AST_MODULE_LOAD_SKIP:
00866          /* try again later */
00867          break;
00868       }
00869    }
00870    AST_LIST_TRAVERSE_SAFE_END;
00871 
00872    /* now load everything else */
00873    AST_LIST_TRAVERSE_SAFE_BEGIN(&load_order, order, entry) {
00874       switch (load_resource(order->resource, 0)) {
00875       case AST_MODULE_LOAD_SUCCESS:
00876       case AST_MODULE_LOAD_DECLINE:
00877          AST_LIST_REMOVE_CURRENT(&load_order, entry);
00878          free(order->resource);
00879          free(order);
00880          break;
00881       case AST_MODULE_LOAD_FAILURE:
00882          res = -1;
00883          goto done;
00884       case AST_MODULE_LOAD_SKIP:
00885          /* should not happen */
00886          break;
00887       }
00888    }
00889    AST_LIST_TRAVERSE_SAFE_END;
00890 
00891 done:
00892    while ((order = AST_LIST_REMOVE_HEAD(&load_order, entry))) {
00893       free(order->resource);
00894       free(order);
00895    }
00896 
00897    AST_LIST_UNLOCK(&module_list);
00898 
00899    return res;
00900 }
00901 
00902 void ast_update_use_count(void)
00903 {
00904    /* Notify any module monitors that the use count for a
00905       resource has changed */
00906    struct loadupdate *m;
00907 
00908    AST_LIST_LOCK(&module_list);
00909    AST_LIST_TRAVERSE(&updaters, m, entry)
00910       m->updater();
00911    AST_LIST_UNLOCK(&module_list);
00912 }
00913 
00914 int ast_update_module_list(int (*modentry)(const char *module, const char *description, int usecnt, const char *like),
00915             const char *like)
00916 {
00917    struct ast_module *cur;
00918    int unlock = -1;
00919    int total_mod_loaded = 0;
00920 
00921    if (AST_LIST_TRYLOCK(&module_list))
00922       unlock = 0;
00923 
00924    AST_LIST_TRAVERSE(&module_list, cur, entry) {
00925       total_mod_loaded += modentry(cur->resource, cur->info->description, cur->usecount, like);
00926    }
00927 
00928    if (unlock)
00929       AST_LIST_UNLOCK(&module_list);
00930 
00931    return total_mod_loaded;
00932 }
00933 
00934 int ast_loader_register(int (*v)(void))
00935 {
00936    struct loadupdate *tmp;
00937 
00938    if (!(tmp = ast_malloc(sizeof(*tmp))))
00939       return -1;
00940 
00941    tmp->updater = v;
00942    AST_LIST_LOCK(&module_list);
00943    AST_LIST_INSERT_HEAD(&updaters, tmp, entry);
00944    AST_LIST_UNLOCK(&module_list);
00945 
00946    return 0;
00947 }
00948 
00949 int ast_loader_unregister(int (*v)(void))
00950 {
00951    struct loadupdate *cur;
00952 
00953    AST_LIST_LOCK(&module_list);
00954    AST_LIST_TRAVERSE_SAFE_BEGIN(&updaters, cur, entry) {
00955       if (cur->updater == v)  {
00956          AST_LIST_REMOVE_CURRENT(&updaters, entry);
00957          break;
00958       }
00959    }
00960    AST_LIST_TRAVERSE_SAFE_END;
00961    AST_LIST_UNLOCK(&module_list);
00962 
00963    return cur ? 0 : -1;
00964 }
00965 
00966 struct ast_module *ast_module_ref(struct ast_module *mod)
00967 {
00968    ast_atomic_fetchadd_int(&mod->usecount, +1);
00969    ast_update_use_count();
00970 
00971    return mod;
00972 }
00973 
00974 void ast_module_unref(struct ast_module *mod)
00975 {
00976    ast_atomic_fetchadd_int(&mod->usecount, -1);
00977    ast_update_use_count();
00978 }

Generated on Fri Sep 25 19:28:12 2009 for Asterisk - the Open Source PBX by  doxygen 1.5.5