Mon Jul 14 17:24:58 2008

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: 104596 $")
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          if (!name)
00589             continue;
00590          ast_log(LOG_NOTICE, "The module '%s' was not properly initialized.  "
00591             "Before reloading the module, you must run \"module load %s\" "
00592             "and fix whatever is preventing the module from being initialized.\n",
00593             name, name);
00594          res = 2; /* Don't report that the module was not found */
00595          break;
00596       }
00597 
00598       if (!info->reload) { /* cannot be reloaded */
00599          if (res < 1)   /* store result if possible */
00600             res = 1; /* 1 = no reload() method */
00601          continue;
00602       }
00603 
00604       res = 2;
00605       if (option_verbose > 2)
00606          ast_verbose(VERBOSE_PREFIX_3 "Reloading module '%s' (%s)\n", cur->resource, info->description);
00607       info->reload();
00608    }
00609    AST_LIST_UNLOCK(&module_list);
00610 
00611    ast_mutex_unlock(&reloadlock);
00612 
00613    return res;
00614 }
00615 
00616 static unsigned int inspect_module(const struct ast_module *mod)
00617 {
00618    if (!mod->info->description) {
00619       ast_log(LOG_WARNING, "Module '%s' does not provide a description.\n", mod->resource);
00620       return 1;
00621    }
00622 
00623    if (!mod->info->key) {
00624       ast_log(LOG_WARNING, "Module '%s' does not provide a license key.\n", mod->resource);
00625       return 1;
00626    }
00627 
00628    if (verify_key((unsigned char *) mod->info->key)) {
00629       ast_log(LOG_WARNING, "Module '%s' did not provide a valid license key.\n", mod->resource);
00630       return 1;
00631    }
00632 
00633    if (!ast_test_flag(mod->info, AST_MODFLAG_BUILDSUM)) {
00634       /*
00635       ast_log(LOG_WARNING, "Module '%s' was not compiled against a recent version of Asterisk and may cause instability.\n", mod->resource);
00636       */
00637    } else if (!ast_strlen_zero(mod->info->buildopt_sum) &&
00638          strcmp(buildopt_sum, mod->info->buildopt_sum)) {
00639       ast_log(LOG_WARNING, "Module '%s' was not compiled with the same compile-time options as this version of Asterisk.\n", mod->resource);
00640       ast_log(LOG_WARNING, "Module '%s' will not be initialized as it may cause instability.\n", mod->resource);
00641       return 1;
00642    }
00643 
00644    return 0;
00645 }
00646 
00647 static enum ast_module_load_result load_resource(const char *resource_name, unsigned int global_symbols_only)
00648 {
00649    struct ast_module *mod;
00650    enum ast_module_load_result res = AST_MODULE_LOAD_SUCCESS;
00651    char tmp[256];
00652 
00653    if ((mod = find_resource(resource_name, 0))) {
00654       if (mod->flags.running) {
00655          ast_log(LOG_WARNING, "Module '%s' already exists.\n", resource_name);
00656          return AST_MODULE_LOAD_DECLINE;
00657       }
00658       if (global_symbols_only && !ast_test_flag(mod->info, AST_MODFLAG_GLOBAL_SYMBOLS))
00659          return AST_MODULE_LOAD_SKIP;
00660    } else {
00661 #ifdef LOADABLE_MODULES
00662       if (!(mod = load_dynamic_module(resource_name, global_symbols_only))) {
00663          /* don't generate a warning message during load_modules() */
00664          if (!global_symbols_only) {
00665             ast_log(LOG_WARNING, "Module '%s' could not be loaded.\n", resource_name);
00666             return AST_MODULE_LOAD_DECLINE;
00667          } else {
00668             return AST_MODULE_LOAD_SKIP;
00669          }
00670       }
00671 #else
00672       ast_log(LOG_WARNING, "Module '%s' could not be loaded.\n", resource_name);
00673       return AST_MODULE_LOAD_DECLINE;
00674 #endif
00675    }
00676 
00677    if (inspect_module(mod)) {
00678       ast_log(LOG_WARNING, "Module '%s' could not be loaded.\n", resource_name);
00679 #ifdef LOADABLE_MODULES
00680       unload_dynamic_module(mod);
00681 #endif
00682       return AST_MODULE_LOAD_DECLINE;
00683    }
00684 
00685    mod->flags.declined = 0;
00686 
00687    if (mod->info->load)
00688       res = mod->info->load();
00689 
00690    switch (res) {
00691    case AST_MODULE_LOAD_SUCCESS:
00692       if (!ast_fully_booted) {
00693          if (option_verbose)
00694             ast_verbose("%s => (%s)\n", resource_name, term_color(tmp, mod->info->description, COLOR_BROWN, COLOR_BLACK, sizeof(tmp)));
00695          if (ast_opt_console && !option_verbose)
00696             ast_verbose( ".");
00697       } else {
00698          if (option_verbose)
00699             ast_verbose(VERBOSE_PREFIX_1 "Loaded %s => (%s)\n", resource_name, mod->info->description);
00700       }
00701 
00702       mod->flags.running = 1;
00703 
00704       ast_update_use_count();
00705       break;
00706    case AST_MODULE_LOAD_DECLINE:
00707       mod->flags.declined = 1;
00708       break;
00709    case AST_MODULE_LOAD_FAILURE:
00710       break;
00711    case AST_MODULE_LOAD_SKIP:
00712       /* modules should never return this value */
00713       break;
00714    }
00715 
00716    return res;
00717 }
00718 
00719 int ast_load_resource(const char *resource_name)
00720 {
00721        AST_LIST_LOCK(&module_list);
00722        load_resource(resource_name, 0);
00723        AST_LIST_UNLOCK(&module_list);
00724 
00725        return 0;
00726 }
00727 
00728 struct load_order_entry {
00729    char *resource;
00730    AST_LIST_ENTRY(load_order_entry) entry;
00731 };
00732 
00733 AST_LIST_HEAD_NOLOCK(load_order, load_order_entry);
00734 
00735 static struct load_order_entry *add_to_load_order(const char *resource, struct load_order *load_order)
00736 {
00737    struct load_order_entry *order;
00738 
00739    AST_LIST_TRAVERSE(load_order, order, entry) {
00740       if (!resource_name_match(order->resource, resource))
00741          return NULL;
00742    }
00743 
00744    if (!(order = ast_calloc(1, sizeof(*order))))
00745       return NULL;
00746 
00747    order->resource = ast_strdup(resource);
00748    AST_LIST_INSERT_TAIL(load_order, order, entry);
00749 
00750    return order;
00751 }
00752 
00753 int load_modules(unsigned int preload_only)
00754 {
00755    struct ast_config *cfg;
00756    struct ast_module *mod;
00757    struct load_order_entry *order;
00758    struct ast_variable *v;
00759    unsigned int load_count;
00760    struct load_order load_order;
00761    int res = 0;
00762 #ifdef LOADABLE_MODULES
00763    struct dirent *dirent;
00764    DIR *dir;
00765 #endif
00766 
00767    /* all embedded modules have registered themselves by now */
00768    embedding = 0;
00769 
00770    if (option_verbose)
00771       ast_verbose("Asterisk Dynamic Loader Starting:\n");
00772 
00773    AST_LIST_HEAD_INIT_NOLOCK(&load_order);
00774 
00775    AST_LIST_LOCK(&module_list);
00776 
00777    if (!(cfg = ast_config_load(AST_MODULE_CONFIG))) {
00778       ast_log(LOG_WARNING, "No '%s' found, no modules will be loaded.\n", AST_MODULE_CONFIG);
00779       goto done;
00780    }
00781 
00782    /* first, find all the modules we have been explicitly requested to load */
00783    for (v = ast_variable_browse(cfg, "modules"); v; v = v->next) {
00784       if (!strcasecmp(v->name, preload_only ? "preload" : "load"))
00785          add_to_load_order(v->value, &load_order);
00786    }
00787 
00788    /* check if 'autoload' is on */
00789    if (!preload_only && ast_true(ast_variable_retrieve(cfg, "modules", "autoload"))) {
00790       /* if so, first add all the embedded modules that are not already running to the load order */
00791       AST_LIST_TRAVERSE(&module_list, mod, entry) {
00792          /* if it's not embedded, skip it */
00793          if (mod->lib)
00794             continue;
00795 
00796          if (mod->flags.running)
00797             continue;
00798 
00799          order = add_to_load_order(mod->resource, &load_order);
00800       }
00801 
00802 #ifdef LOADABLE_MODULES
00803       /* if we are allowed to load dynamic modules, scan the directory for
00804          for all available modules and add them as well */
00805       if ((dir  = opendir(ast_config_AST_MODULE_DIR))) {
00806          while ((dirent = readdir(dir))) {
00807             int ld = strlen(dirent->d_name);
00808 
00809             /* Must end in .so to load it.  */
00810 
00811             if (ld < 4)
00812                continue;
00813 
00814             if (strcasecmp(dirent->d_name + ld - 3, ".so"))
00815                continue;
00816 
00817             /* if there is already a module by this name in the module_list,
00818                skip this file */
00819             if (find_resource(dirent->d_name, 0))
00820                continue;
00821 
00822             add_to_load_order(dirent->d_name, &load_order);
00823          }
00824 
00825          closedir(dir);
00826       } else {
00827          if (!ast_opt_quiet)
00828             ast_log(LOG_WARNING, "Unable to open modules directory '%s'.\n",
00829                ast_config_AST_MODULE_DIR);
00830       }
00831 #endif
00832    }
00833 
00834    /* now scan the config for any modules we are prohibited from loading and
00835       remove them from the load order */
00836    for (v = ast_variable_browse(cfg, "modules"); v; v = v->next) {
00837       if (strcasecmp(v->name, "noload"))
00838          continue;
00839 
00840       AST_LIST_TRAVERSE_SAFE_BEGIN(&load_order, order, entry) {
00841          if (!resource_name_match(order->resource, v->value)) {
00842             AST_LIST_REMOVE_CURRENT(&load_order, entry);
00843             free(order->resource);
00844             free(order);
00845          }
00846       }
00847       AST_LIST_TRAVERSE_SAFE_END;
00848    }
00849 
00850    /* we are done with the config now, all the information we need is in the
00851       load_order list */
00852    ast_config_destroy(cfg);
00853 
00854    load_count = 0;
00855    AST_LIST_TRAVERSE(&load_order, order, entry)
00856       load_count++;
00857 
00858    if (load_count)
00859       ast_log(LOG_NOTICE, "%d modules will be loaded.\n", load_count);
00860 
00861    /* first, load only modules that provide global symbols */
00862    AST_LIST_TRAVERSE_SAFE_BEGIN(&load_order, order, entry) {
00863       switch (load_resource(order->resource, 1)) {
00864       case AST_MODULE_LOAD_SUCCESS:
00865       case AST_MODULE_LOAD_DECLINE:
00866          AST_LIST_REMOVE_CURRENT(&load_order, entry);
00867          free(order->resource);
00868          free(order);
00869          break;
00870       case AST_MODULE_LOAD_FAILURE:
00871          res = -1;
00872          goto done;
00873       case AST_MODULE_LOAD_SKIP:
00874          /* try again later */
00875          break;
00876       }
00877    }
00878    AST_LIST_TRAVERSE_SAFE_END;
00879 
00880    /* now load everything else */
00881    AST_LIST_TRAVERSE_SAFE_BEGIN(&load_order, order, entry) {
00882       switch (load_resource(order->resource, 0)) {
00883       case AST_MODULE_LOAD_SUCCESS:
00884       case AST_MODULE_LOAD_DECLINE:
00885          AST_LIST_REMOVE_CURRENT(&load_order, entry);
00886          free(order->resource);
00887          free(order);
00888          break;
00889       case AST_MODULE_LOAD_FAILURE:
00890          res = -1;
00891          goto done;
00892       case AST_MODULE_LOAD_SKIP:
00893          /* should not happen */
00894          break;
00895       }
00896    }
00897    AST_LIST_TRAVERSE_SAFE_END;
00898 
00899 done:
00900    while ((order = AST_LIST_REMOVE_HEAD(&load_order, entry))) {
00901       free(order->resource);
00902       free(order);
00903    }
00904 
00905    AST_LIST_UNLOCK(&module_list);
00906 
00907    return res;
00908 }
00909 
00910 void ast_update_use_count(void)
00911 {
00912    /* Notify any module monitors that the use count for a
00913       resource has changed */
00914    struct loadupdate *m;
00915 
00916    AST_LIST_LOCK(&updaters);
00917    AST_LIST_TRAVERSE(&updaters, m, entry)
00918       m->updater();
00919    AST_LIST_UNLOCK(&updaters);
00920 }
00921 
00922 int ast_update_module_list(int (*modentry)(const char *module, const char *description, int usecnt, const char *like),
00923             const char *like)
00924 {
00925    struct ast_module *cur;
00926    int unlock = -1;
00927    int total_mod_loaded = 0;
00928 
00929    if (AST_LIST_TRYLOCK(&module_list))
00930       unlock = 0;
00931 
00932    AST_LIST_TRAVERSE(&module_list, cur, entry) {
00933       total_mod_loaded += modentry(cur->resource, cur->info->description, cur->usecount, like);
00934    }
00935 
00936    if (unlock)
00937       AST_LIST_UNLOCK(&module_list);
00938 
00939    return total_mod_loaded;
00940 }
00941 
00942 int ast_loader_register(int (*v)(void))
00943 {
00944    struct loadupdate *tmp;
00945 
00946    if (!(tmp = ast_malloc(sizeof(*tmp))))
00947       return -1;
00948 
00949    tmp->updater = v;
00950    AST_LIST_LOCK(&updaters);
00951    AST_LIST_INSERT_HEAD(&updaters, tmp, entry);
00952    AST_LIST_UNLOCK(&updaters);
00953 
00954    return 0;
00955 }
00956 
00957 int ast_loader_unregister(int (*v)(void))
00958 {
00959    struct loadupdate *cur;
00960 
00961    AST_LIST_LOCK(&updaters);
00962    AST_LIST_TRAVERSE_SAFE_BEGIN(&updaters, cur, entry) {
00963       if (cur->updater == v)  {
00964          AST_LIST_REMOVE_CURRENT(&updaters, entry);
00965          break;
00966       }
00967    }
00968    AST_LIST_TRAVERSE_SAFE_END;
00969    AST_LIST_UNLOCK(&updaters);
00970 
00971    return cur ? 0 : -1;
00972 }
00973 
00974 struct ast_module *ast_module_ref(struct ast_module *mod)
00975 {
00976    ast_atomic_fetchadd_int(&mod->usecount, +1);
00977    ast_update_use_count();
00978 
00979    return mod;
00980 }
00981 
00982 void ast_module_unref(struct ast_module *mod)
00983 {
00984    ast_atomic_fetchadd_int(&mod->usecount, -1);
00985    ast_update_use_count();
00986 }

Generated on Mon Jul 14 17:24:58 2008 for Asterisk - the Open Source PBX by  doxygen 1.5.1