Wed Jan 27 20:02:12 2016

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 /*** MODULEINFO
00031    <support_level>core</support_level>
00032  ***/
00033 
00034 #include "asterisk.h"
00035 
00036 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 413586 $")
00037 
00038 #include "asterisk/_private.h"
00039 #include "asterisk/paths.h"   /* use ast_config_AST_MODULE_DIR */
00040 #include <dirent.h>
00041 
00042 #include "asterisk/linkedlists.h"
00043 #include "asterisk/module.h"
00044 #include "asterisk/config.h"
00045 #include "asterisk/channel.h"
00046 #include "asterisk/term.h"
00047 #include "asterisk/manager.h"
00048 #include "asterisk/cdr.h"
00049 #include "asterisk/enum.h"
00050 #include "asterisk/http.h"
00051 #include "asterisk/lock.h"
00052 #include "asterisk/features.h"
00053 #include "asterisk/dsp.h"
00054 #include "asterisk/udptl.h"
00055 #include "asterisk/heap.h"
00056 #include "asterisk/app.h"
00057 #include "asterisk/test.h"
00058 
00059 #include <dlfcn.h>
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 #ifndef RTLD_LOCAL
00069 #define RTLD_LOCAL 0
00070 #endif
00071 
00072 struct ast_module_user {
00073    struct ast_channel *chan;
00074    AST_LIST_ENTRY(ast_module_user) entry;
00075 };
00076 
00077 AST_LIST_HEAD(module_user_list, ast_module_user);
00078 
00079 static const unsigned char expected_key[] =
00080 { 0x87, 0x76, 0x79, 0x35, 0x23, 0xea, 0x3a, 0xd3,
00081   0x25, 0x2a, 0xbb, 0x35, 0x87, 0xe4, 0x22, 0x24 };
00082 
00083 static char buildopt_sum[33] = AST_BUILDOPT_SUM;
00084 
00085 static unsigned int embedding = 1; /* we always start out by registering embedded modules,
00086                   since they are here before we dlopen() any
00087                */
00088 
00089 struct ast_module {
00090    const struct ast_module_info *info;
00091    void *lib;              /* the shared lib, or NULL if embedded */
00092    int usecount;              /* the number of 'users' currently in this module */
00093    struct module_user_list users;         /* the list of users in the module */
00094    struct {
00095       unsigned int running:1;
00096       unsigned int declined:1;
00097    } flags;
00098    AST_LIST_ENTRY(ast_module) entry;
00099    char resource[0];
00100 };
00101 
00102 static AST_LIST_HEAD_STATIC(module_list, ast_module);
00103 
00104 const char *ast_module_name(const struct ast_module *mod)
00105 {
00106    if (!mod || !mod->info) {
00107       return NULL;
00108    }
00109 
00110    return mod->info->name;
00111 }
00112 
00113 /*
00114  * module_list is cleared by its constructor possibly after
00115  * we start accumulating embedded modules, so we need to
00116  * use another list (without the lock) to accumulate them.
00117  * Then we update the main list when embedding is done.
00118  */
00119 static struct module_list embedded_module_list;
00120 
00121 struct loadupdate {
00122    int (*updater)(void);
00123    AST_LIST_ENTRY(loadupdate) entry;
00124 };
00125 
00126 static AST_LIST_HEAD_STATIC(updaters, loadupdate);
00127 
00128 AST_MUTEX_DEFINE_STATIC(reloadlock);
00129 
00130 struct reload_queue_item {
00131    AST_LIST_ENTRY(reload_queue_item) entry;
00132    char module[0];
00133 };
00134 
00135 static int do_full_reload = 0;
00136 
00137 static AST_LIST_HEAD_STATIC(reload_queue, reload_queue_item);
00138 
00139 /* when dynamic modules are being loaded, ast_module_register() will
00140    need to know what filename the module was loaded from while it
00141    is being registered
00142 */
00143 static struct ast_module *resource_being_loaded;
00144 
00145 /* XXX: should we check for duplicate resource names here? */
00146 
00147 void ast_module_register(const struct ast_module_info *info)
00148 {
00149    struct ast_module *mod;
00150 
00151    if (embedding) {
00152       if (!(mod = ast_calloc(1, sizeof(*mod) + strlen(info->name) + 1)))
00153          return;
00154       strcpy(mod->resource, info->name);
00155    } else {
00156       mod = resource_being_loaded;
00157    }
00158 
00159    mod->info = info;
00160    AST_LIST_HEAD_INIT(&mod->users);
00161 
00162    /* during startup, before the loader has been initialized,
00163       there are no threads, so there is no need to take the lock
00164       on this list to manipulate it. it is also possible that it
00165       might be unsafe to use the list lock at that point... so
00166       let's avoid it altogether
00167    */
00168    if (embedding) {
00169       AST_LIST_INSERT_TAIL(&embedded_module_list, mod, entry);
00170    } else {
00171       AST_LIST_LOCK(&module_list);
00172       /* it is paramount that the new entry be placed at the tail of
00173          the list, otherwise the code that uses dlopen() to load
00174          dynamic modules won't be able to find out if the module it
00175          just opened was registered or failed to load
00176       */
00177       AST_LIST_INSERT_TAIL(&module_list, mod, entry);
00178       AST_LIST_UNLOCK(&module_list);
00179    }
00180 
00181    /* give the module a copy of its own handle, for later use in registrations and the like */
00182    *((struct ast_module **) &(info->self)) = mod;
00183 }
00184 
00185 void ast_module_unregister(const struct ast_module_info *info)
00186 {
00187    struct ast_module *mod = NULL;
00188 
00189    /* it is assumed that the users list in the module structure
00190       will already be empty, or we cannot have gotten to this
00191       point
00192    */
00193    AST_LIST_LOCK(&module_list);
00194    AST_LIST_TRAVERSE_SAFE_BEGIN(&module_list, mod, entry) {
00195       if (mod->info == info) {
00196          AST_LIST_REMOVE_CURRENT(entry);
00197          break;
00198       }
00199    }
00200    AST_LIST_TRAVERSE_SAFE_END;
00201    AST_LIST_UNLOCK(&module_list);
00202 
00203    if (mod) {
00204       AST_LIST_HEAD_DESTROY(&mod->users);
00205       ast_free(mod);
00206    }
00207 }
00208 
00209 struct ast_module_user *__ast_module_user_add(struct ast_module *mod, struct ast_channel *chan)
00210 {
00211    struct ast_module_user *u;
00212 
00213    u = ast_calloc(1, sizeof(*u));
00214    if (!u) {
00215       return NULL;
00216    }
00217 
00218    u->chan = chan;
00219 
00220    AST_LIST_LOCK(&mod->users);
00221    AST_LIST_INSERT_HEAD(&mod->users, u, entry);
00222    AST_LIST_UNLOCK(&mod->users);
00223 
00224    ast_atomic_fetchadd_int(&mod->usecount, +1);
00225 
00226    ast_update_use_count();
00227 
00228    return u;
00229 }
00230 
00231 void __ast_module_user_remove(struct ast_module *mod, struct ast_module_user *u)
00232 {
00233    if (!u) {
00234       return;
00235    }
00236 
00237    AST_LIST_LOCK(&mod->users);
00238    u = AST_LIST_REMOVE(&mod->users, u, entry);
00239    AST_LIST_UNLOCK(&mod->users);
00240    if (!u) {
00241       /*
00242        * Was not in the list.  Either a bad pointer or
00243        * __ast_module_user_hangup_all() has been called.
00244        */
00245       return;
00246    }
00247 
00248    ast_atomic_fetchadd_int(&mod->usecount, -1);
00249    ast_free(u);
00250 
00251    ast_update_use_count();
00252 }
00253 
00254 void __ast_module_user_hangup_all(struct ast_module *mod)
00255 {
00256    struct ast_module_user *u;
00257 
00258    AST_LIST_LOCK(&mod->users);
00259    while ((u = AST_LIST_REMOVE_HEAD(&mod->users, entry))) {
00260       if (u->chan) {
00261          ast_softhangup(u->chan, AST_SOFTHANGUP_APPUNLOAD);
00262       }
00263       ast_atomic_fetchadd_int(&mod->usecount, -1);
00264       ast_free(u);
00265    }
00266    AST_LIST_UNLOCK(&mod->users);
00267 
00268    ast_update_use_count();
00269 }
00270 
00271 /*! \note
00272  * In addition to modules, the reload command handles some extra keywords
00273  * which are listed here together with the corresponding handlers.
00274  * This table is also used by the command completion code.
00275  */
00276 static struct reload_classes {
00277    const char *name;
00278    int (*reload_fn)(void);
00279 } reload_classes[] = {  /* list in alpha order, longest match first for cli completion */
00280    { "cdr", ast_cdr_engine_reload },
00281    { "dnsmgr", dnsmgr_reload },
00282    { "extconfig", read_config_maps },
00283    { "enum",   ast_enum_reload },
00284    { "manager",   reload_manager },
00285    { "http",   ast_http_reload },
00286    { "logger", logger_reload },
00287    { "features",  ast_features_reload },
00288    { "dsp", ast_dsp_reload},
00289    { "udptl",  ast_udptl_reload },
00290    { "indications", ast_indications_reload },
00291    { "cel",        ast_cel_engine_reload },
00292    { "plc",        ast_plc_reload },
00293    { NULL,  NULL }
00294 };
00295 
00296 static int printdigest(const unsigned char *d)
00297 {
00298    int x, pos;
00299    char buf[256]; /* large enough so we don't have to worry */
00300 
00301    for (pos = 0, x = 0; x < 16; x++)
00302       pos += sprintf(buf + pos, " %02x", (unsigned)*d++);
00303 
00304    ast_debug(1, "Unexpected signature:%s\n", buf);
00305 
00306    return 0;
00307 }
00308 
00309 static int key_matches(const unsigned char *key1, const unsigned char *key2)
00310 {
00311    int x;
00312 
00313    for (x = 0; x < 16; x++) {
00314       if (key1[x] != key2[x])
00315          return 0;
00316    }
00317 
00318    return 1;
00319 }
00320 
00321 static int verify_key(const unsigned char *key)
00322 {
00323    struct MD5Context c;
00324    unsigned char digest[16];
00325 
00326    MD5Init(&c);
00327    MD5Update(&c, key, strlen((char *)key));
00328    MD5Final(digest, &c);
00329 
00330    if (key_matches(expected_key, digest))
00331       return 0;
00332 
00333    printdigest(digest);
00334 
00335    return -1;
00336 }
00337 
00338 static int resource_name_match(const char *name1_in, const char *name2_in)
00339 {
00340    char *name1 = (char *) name1_in;
00341    char *name2 = (char *) name2_in;
00342 
00343    /* trim off any .so extensions */
00344    if (!strcasecmp(name1 + strlen(name1) - 3, ".so")) {
00345       name1 = ast_strdupa(name1);
00346       name1[strlen(name1) - 3] = '\0';
00347    }
00348    if (!strcasecmp(name2 + strlen(name2) - 3, ".so")) {
00349       name2 = ast_strdupa(name2);
00350       name2[strlen(name2) - 3] = '\0';
00351    }
00352 
00353    return strcasecmp(name1, name2);
00354 }
00355 
00356 static struct ast_module *find_resource(const char *resource, int do_lock)
00357 {
00358    struct ast_module *cur;
00359 
00360    if (do_lock)
00361       AST_LIST_LOCK(&module_list);
00362 
00363    AST_LIST_TRAVERSE(&module_list, cur, entry) {
00364       if (!resource_name_match(resource, cur->resource))
00365          break;
00366    }
00367 
00368    if (do_lock)
00369       AST_LIST_UNLOCK(&module_list);
00370 
00371    return cur;
00372 }
00373 
00374 #ifdef LOADABLE_MODULES
00375 
00376 static void close_lib(const char *name, void *lib)
00377 {
00378    char *error;
00379 
00380    if (!lib) {
00381       return;
00382    }
00383 
00384    /* Clear any existing error */
00385    dlerror();
00386    if (dlclose(lib)) {
00387       error = dlerror();
00388       ast_log(AST_LOG_ERROR, "Failure in dlclose for module '%s': %s\n",
00389          S_OR(name, "unknown"), S_OR(error, "Unknown error"));
00390    }
00391 }
00392 
00393 static void unload_dynamic_module(struct ast_module *mod)
00394 {
00395    void *lib = mod->lib;
00396 
00397    /* WARNING: the structure pointed to by mod is going to
00398       disappear when this operation succeeds, so we can't
00399       dereference it */
00400    close_lib(ast_module_name(mod), lib);
00401 }
00402 
00403 static enum ast_module_load_result load_resource(const char *resource_name, unsigned int global_symbols_only, struct ast_heap *resource_heap, int required);
00404 
00405 static struct ast_module *load_dynamic_module(const char *resource_in, unsigned int global_symbols_only, struct ast_heap *resource_heap)
00406 {
00407    char fn[PATH_MAX] = "";
00408    void *lib = NULL;
00409    struct ast_module *mod;
00410    unsigned int wants_global;
00411    int space;  /* room needed for the descriptor */
00412    int missing_so = 0;
00413 
00414    space = sizeof(*resource_being_loaded) + strlen(resource_in) + 1;
00415    if (strcasecmp(resource_in + strlen(resource_in) - 3, ".so")) {
00416       missing_so = 1;
00417       space += 3; /* room for the extra ".so" */
00418    }
00419 
00420    snprintf(fn, sizeof(fn), "%s/%s%s", ast_config_AST_MODULE_DIR, resource_in, missing_so ? ".so" : "");
00421 
00422    /* make a first load of the module in 'quiet' mode... don't try to resolve
00423       any symbols, and don't export any symbols. this will allow us to peek into
00424       the module's info block (if available) to see what flags it has set */
00425 
00426    resource_being_loaded = ast_calloc(1, space);
00427    if (!resource_being_loaded)
00428       return NULL;
00429    strcpy(resource_being_loaded->resource, resource_in);
00430    if (missing_so)
00431       strcat(resource_being_loaded->resource, ".so");
00432 
00433    if (!(lib = dlopen(fn, RTLD_LAZY | RTLD_LOCAL))) {
00434       ast_log(LOG_WARNING, "Error loading module '%s': %s\n", resource_in, dlerror());
00435       ast_free(resource_being_loaded);
00436       return NULL;
00437    }
00438 
00439    /* the dlopen() succeeded, let's find out if the module
00440       registered itself */
00441    /* note that this will only work properly as long as
00442       ast_module_register() (which is called by the module's
00443       constructor) places the new module at the tail of the
00444       module_list
00445    */
00446    if (resource_being_loaded != (mod = AST_LIST_LAST(&module_list))) {
00447       ast_log(LOG_WARNING, "Module '%s' did not register itself during load\n", resource_in);
00448       /* no, it did not, so close it and return */
00449       close_lib(resource_in, lib);
00450       /* note that the module's destructor will call ast_module_unregister(),
00451          which will free the structure we allocated in resource_being_loaded */
00452       return NULL;
00453    }
00454 
00455    wants_global = ast_test_flag(mod->info, AST_MODFLAG_GLOBAL_SYMBOLS);
00456 
00457    /* if we are being asked only to load modules that provide global symbols,
00458       and this one does not, then close it and return */
00459    if (global_symbols_only && !wants_global) {
00460       close_lib(resource_in, lib);
00461       return NULL;
00462    }
00463 
00464    /* This section is a workaround for a gcc 4.1 bug that has already been
00465     * fixed in later versions.  Unfortunately, some distributions, such as
00466     * RHEL/CentOS 5, distribute gcc 4.1, so we're stuck with having to deal
00467     * with this issue.  This basically ensures that optional_api modules are
00468     * loaded before any module which requires their functionality. */
00469 #if !defined(HAVE_ATTRIBUTE_weak_import) && !defined(HAVE_ATTRIBUTE_weakref)
00470    if (!ast_strlen_zero(mod->info->nonoptreq)) {
00471       /* Force any required dependencies to load */
00472       char *each, *required_resource = ast_strdupa(mod->info->nonoptreq);
00473       while ((each = strsep(&required_resource, ","))) {
00474          struct ast_module *dependency;
00475          each = ast_strip(each);
00476          dependency = find_resource(each, 0);
00477          /* Is it already loaded? */
00478          if (!dependency) {
00479             load_resource(each, global_symbols_only, resource_heap, 1);
00480          }
00481       }
00482    }
00483 #endif
00484 
00485    close_lib(resource_in, lib);
00486    resource_being_loaded = NULL;
00487 
00488    /* start the load process again */
00489    resource_being_loaded = ast_calloc(1, space);
00490    if (!resource_being_loaded)
00491       return NULL;
00492    strcpy(resource_being_loaded->resource, resource_in);
00493    if (missing_so)
00494       strcat(resource_being_loaded->resource, ".so");
00495 
00496    if (!(lib = dlopen(fn, wants_global ? RTLD_LAZY | RTLD_GLOBAL : RTLD_NOW | RTLD_LOCAL))) {
00497       ast_log(LOG_WARNING, "Error loading module '%s': %s\n", resource_in, dlerror());
00498       ast_free(resource_being_loaded);
00499       return NULL;
00500    }
00501 
00502    /* since the module was successfully opened, and it registered itself
00503       the previous time we did that, we're going to assume it worked this
00504       time too :) */
00505 
00506    AST_LIST_LAST(&module_list)->lib = lib;
00507    resource_being_loaded = NULL;
00508 
00509    return AST_LIST_LAST(&module_list);
00510 }
00511 #endif
00512 
00513 void ast_module_shutdown(void)
00514 {
00515    struct ast_module *mod;
00516    int somethingchanged = 1, final = 0;
00517 
00518    AST_LIST_LOCK(&module_list);
00519 
00520    /*!\note Some resources, like timers, are started up dynamically, and thus
00521     * may be still in use, even if all channels are dead.  We must therefore
00522     * check the usecount before asking modules to unload. */
00523    do {
00524       if (!somethingchanged) {
00525          /*!\note If we go through the entire list without changing
00526           * anything, ignore the usecounts and unload, then exit. */
00527          final = 1;
00528       }
00529 
00530       /* Reset flag before traversing the list */
00531       somethingchanged = 0;
00532 
00533       AST_LIST_TRAVERSE_SAFE_BEGIN(&module_list, mod, entry) {
00534          if (!final && mod->usecount) {
00535             continue;
00536          }
00537          AST_LIST_REMOVE_CURRENT(entry);
00538          if (mod->flags.running && !mod->flags.declined && mod->info->unload) {
00539             mod->info->unload();
00540          }
00541          AST_LIST_HEAD_DESTROY(&mod->users);
00542          free(mod);
00543          somethingchanged = 1;
00544       }
00545       AST_LIST_TRAVERSE_SAFE_END;
00546    } while (somethingchanged && !final);
00547 
00548    AST_LIST_UNLOCK(&module_list);
00549 }
00550 
00551 int ast_unload_resource(const char *resource_name, enum ast_module_unload_mode force)
00552 {
00553    struct ast_module *mod;
00554    int res = -1;
00555    int error = 0;
00556 
00557    AST_LIST_LOCK(&module_list);
00558 
00559    if (!(mod = find_resource(resource_name, 0))) {
00560       AST_LIST_UNLOCK(&module_list);
00561       ast_log(LOG_WARNING, "Unload failed, '%s' could not be found\n", resource_name);
00562       return -1;
00563    }
00564 
00565    if (!mod->flags.running || mod->flags.declined) {
00566       ast_log(LOG_WARNING, "Unload failed, '%s' is not loaded.\n", resource_name);
00567       error = 1;
00568    }
00569 
00570    if (!error && (mod->usecount > 0)) {
00571       if (force)
00572          ast_log(LOG_WARNING, "Warning:  Forcing removal of module '%s' with use count %d\n",
00573             resource_name, mod->usecount);
00574       else {
00575          ast_log(LOG_WARNING, "Soft unload failed, '%s' has use count %d\n", resource_name,
00576             mod->usecount);
00577          error = 1;
00578       }
00579    }
00580 
00581    if (!error) {
00582       /* Request any channels attached to the module to hangup. */
00583       __ast_module_user_hangup_all(mod);
00584 
00585       res = mod->info->unload();
00586       if (res) {
00587          ast_log(LOG_WARNING, "Firm unload failed for %s\n", resource_name);
00588          if (force <= AST_FORCE_FIRM) {
00589             error = 1;
00590          } else {
00591             ast_log(LOG_WARNING, "** Dangerous **: Unloading resource anyway, at user request\n");
00592          }
00593       }
00594 
00595       if (!error) {
00596          /*
00597           * Request hangup on any channels that managed to get attached
00598           * while we called the module unload function.
00599           */
00600          __ast_module_user_hangup_all(mod);
00601          sched_yield();
00602       }
00603    }
00604 
00605    if (!error)
00606       mod->flags.running = mod->flags.declined = 0;
00607 
00608    AST_LIST_UNLOCK(&module_list);
00609 
00610    if (!error && !mod->lib && mod->info && mod->info->restore_globals)
00611       mod->info->restore_globals();
00612 
00613 #ifdef LOADABLE_MODULES
00614    if (!error) {
00615       unload_dynamic_module(mod);
00616       ast_test_suite_event_notify("MODULE_UNLOAD", "Message: %s", resource_name);
00617    }
00618 #endif
00619 
00620    if (!error)
00621       ast_update_use_count();
00622 
00623    return res;
00624 }
00625 
00626 char *ast_module_helper(const char *line, const char *word, int pos, int state, int rpos, int needsreload)
00627 {
00628    struct ast_module *cur;
00629    int i, which=0, l = strlen(word);
00630    char *ret = NULL;
00631 
00632    if (pos != rpos)
00633       return NULL;
00634 
00635    AST_LIST_LOCK(&module_list);
00636    AST_LIST_TRAVERSE(&module_list, cur, entry) {
00637       if (!strncasecmp(word, cur->resource, l) &&
00638           (cur->info->reload || !needsreload) &&
00639           ++which > state) {
00640          ret = ast_strdup(cur->resource);
00641          break;
00642       }
00643    }
00644    AST_LIST_UNLOCK(&module_list);
00645 
00646    if (!ret) {
00647       for (i=0; !ret && reload_classes[i].name; i++) {
00648          if (!strncasecmp(word, reload_classes[i].name, l) && ++which > state)
00649             ret = ast_strdup(reload_classes[i].name);
00650       }
00651    }
00652 
00653    return ret;
00654 }
00655 
00656 void ast_process_pending_reloads(void)
00657 {
00658    struct reload_queue_item *item;
00659 
00660    if (!ast_fully_booted) {
00661       return;
00662    }
00663 
00664    AST_LIST_LOCK(&reload_queue);
00665 
00666    if (do_full_reload) {
00667       do_full_reload = 0;
00668       AST_LIST_UNLOCK(&reload_queue);
00669       ast_log(LOG_NOTICE, "Executing deferred reload request.\n");
00670       ast_module_reload(NULL);
00671       return;
00672    }
00673 
00674    while ((item = AST_LIST_REMOVE_HEAD(&reload_queue, entry))) {
00675       ast_log(LOG_NOTICE, "Executing deferred reload request for module '%s'.\n", item->module);
00676       ast_module_reload(item->module);
00677       ast_free(item);
00678    }
00679 
00680    AST_LIST_UNLOCK(&reload_queue);
00681 }
00682 
00683 static void queue_reload_request(const char *module)
00684 {
00685    struct reload_queue_item *item;
00686 
00687    AST_LIST_LOCK(&reload_queue);
00688 
00689    if (do_full_reload) {
00690       AST_LIST_UNLOCK(&reload_queue);
00691       return;
00692    }
00693 
00694    if (ast_strlen_zero(module)) {
00695       /* A full reload request (when module is NULL) wipes out any previous
00696          reload requests and causes the queue to ignore future ones */
00697       while ((item = AST_LIST_REMOVE_HEAD(&reload_queue, entry))) {
00698          ast_free(item);
00699       }
00700       do_full_reload = 1;
00701    } else {
00702       /* No reason to add the same module twice */
00703       AST_LIST_TRAVERSE(&reload_queue, item, entry) {
00704          if (!strcasecmp(item->module, module)) {
00705             AST_LIST_UNLOCK(&reload_queue);
00706             return;
00707          }
00708       }
00709       item = ast_calloc(1, sizeof(*item) + strlen(module) + 1);
00710       if (!item) {
00711          ast_log(LOG_ERROR, "Failed to allocate reload queue item.\n");
00712          AST_LIST_UNLOCK(&reload_queue);
00713          return;
00714       }
00715       strcpy(item->module, module);
00716       AST_LIST_INSERT_TAIL(&reload_queue, item, entry);
00717    }
00718    AST_LIST_UNLOCK(&reload_queue);
00719 }
00720 
00721 int ast_module_reload(const char *name)
00722 {
00723    struct ast_module *cur;
00724    int res = 0; /* return value. 0 = not found, others, see below */
00725    int i;
00726 
00727    /* If we aren't fully booted, we just pretend we reloaded but we queue this
00728       up to run once we are booted up. */
00729    if (!ast_fully_booted) {
00730       queue_reload_request(name);
00731       return 0;
00732    }
00733 
00734    if (ast_mutex_trylock(&reloadlock)) {
00735       ast_verbose("The previous reload command didn't finish yet\n");
00736       return -1;  /* reload already in progress */
00737    }
00738    ast_lastreloadtime = ast_tvnow();
00739 
00740    if (ast_opt_lock_confdir) {
00741       int try;
00742       int res;
00743       for (try = 1, res = AST_LOCK_TIMEOUT; try < 6 && (res == AST_LOCK_TIMEOUT); try++) {
00744          res = ast_lock_path(ast_config_AST_CONFIG_DIR);
00745          if (res == AST_LOCK_TIMEOUT) {
00746             ast_log(LOG_WARNING, "Failed to grab lock on %s, try %d\n", ast_config_AST_CONFIG_DIR, try);
00747          }
00748       }
00749       if (res != AST_LOCK_SUCCESS) {
00750          ast_verbose("Cannot grab lock on %s\n", ast_config_AST_CONFIG_DIR);
00751          ast_mutex_unlock(&reloadlock);
00752          return -1;
00753       }
00754    }
00755 
00756    /* Call "predefined" reload here first */
00757    for (i = 0; reload_classes[i].name; i++) {
00758       if (!name || !strcasecmp(name, reload_classes[i].name)) {
00759          if (!reload_classes[i].reload_fn()) {
00760             ast_test_suite_event_notify("MODULE_RELOAD", "Message: %s", name);
00761          }
00762          res = 2; /* found and reloaded */
00763       }
00764    }
00765 
00766    if (name && res) {
00767       if (ast_opt_lock_confdir) {
00768          ast_unlock_path(ast_config_AST_CONFIG_DIR);
00769       }
00770       ast_mutex_unlock(&reloadlock);
00771       return res;
00772    }
00773 
00774    AST_LIST_LOCK(&module_list);
00775    AST_LIST_TRAVERSE(&module_list, cur, entry) {
00776       const struct ast_module_info *info = cur->info;
00777 
00778       if (name && resource_name_match(name, cur->resource))
00779          continue;
00780 
00781       if (!cur->flags.running || cur->flags.declined) {
00782          if (!name)
00783             continue;
00784          ast_log(LOG_NOTICE, "The module '%s' was not properly initialized.  "
00785             "Before reloading the module, you must run \"module load %s\" "
00786             "and fix whatever is preventing the module from being initialized.\n",
00787             name, name);
00788          res = 2; /* Don't report that the module was not found */
00789          break;
00790       }
00791 
00792       if (!info->reload) { /* cannot be reloaded */
00793          /* Nothing to reload, so reload is successful */
00794          ast_test_suite_event_notify("MODULE_RELOAD", "Message: %s", cur->resource);
00795          if (res < 1)   /* store result if possible */
00796             res = 1; /* 1 = no reload() method */
00797          continue;
00798       }
00799 
00800       res = 2;
00801       ast_verb(3, "Reloading module '%s' (%s)\n", cur->resource, info->description);
00802       if (!info->reload()) {
00803          ast_test_suite_event_notify("MODULE_RELOAD", "Message: %s", cur->resource);
00804       }
00805    }
00806    AST_LIST_UNLOCK(&module_list);
00807 
00808    if (ast_opt_lock_confdir) {
00809       ast_unlock_path(ast_config_AST_CONFIG_DIR);
00810    }
00811    ast_mutex_unlock(&reloadlock);
00812 
00813    return res;
00814 }
00815 
00816 static unsigned int inspect_module(const struct ast_module *mod)
00817 {
00818    if (!mod->info->description) {
00819       ast_log(LOG_WARNING, "Module '%s' does not provide a description.\n", mod->resource);
00820       return 1;
00821    }
00822 
00823    if (!mod->info->key) {
00824       ast_log(LOG_WARNING, "Module '%s' does not provide a license key.\n", mod->resource);
00825       return 1;
00826    }
00827 
00828    if (verify_key((unsigned char *) mod->info->key)) {
00829       ast_log(LOG_WARNING, "Module '%s' did not provide a valid license key.\n", mod->resource);
00830       return 1;
00831    }
00832 
00833    if (!ast_strlen_zero(mod->info->buildopt_sum) &&
00834        strcmp(buildopt_sum, mod->info->buildopt_sum)) {
00835       ast_log(LOG_WARNING, "Module '%s' was not compiled with the same compile-time options as this version of Asterisk.\n", mod->resource);
00836       ast_log(LOG_WARNING, "Module '%s' will not be initialized as it may cause instability.\n", mod->resource);
00837       return 1;
00838    }
00839 
00840    return 0;
00841 }
00842 
00843 static enum ast_module_load_result start_resource(struct ast_module *mod)
00844 {
00845    char tmp[256];
00846    enum ast_module_load_result res;
00847 
00848    if (mod->flags.running) {
00849       return AST_MODULE_LOAD_SUCCESS;
00850    }
00851 
00852    if (!mod->info->load) {
00853       return AST_MODULE_LOAD_FAILURE;
00854    }
00855 
00856    res = mod->info->load();
00857 
00858    switch (res) {
00859    case AST_MODULE_LOAD_SUCCESS:
00860       if (!ast_fully_booted) {
00861          ast_verb(1, "%s => (%s)\n", mod->resource, term_color(tmp, mod->info->description, COLOR_BROWN, COLOR_BLACK, sizeof(tmp)));
00862          if (ast_opt_console && !option_verbose)
00863             ast_verbose( ".");
00864       } else {
00865          ast_verb(1, "Loaded %s => (%s)\n", mod->resource, mod->info->description);
00866       }
00867 
00868       mod->flags.running = 1;
00869 
00870       ast_update_use_count();
00871       break;
00872    case AST_MODULE_LOAD_DECLINE:
00873       mod->flags.declined = 1;
00874       break;
00875    case AST_MODULE_LOAD_FAILURE:
00876    case AST_MODULE_LOAD_SKIP: /* modules should never return this value */
00877    case AST_MODULE_LOAD_PRIORITY:
00878       break;
00879    }
00880 
00881    return res;
00882 }
00883 
00884 /*! loads a resource based upon resource_name. If global_symbols_only is set
00885  *  only modules with global symbols will be loaded.
00886  *
00887  *  If the ast_heap is provided (not NULL) the module is found and added to the
00888  *  heap without running the module's load() function.  By doing this, modules
00889  *  added to the resource_heap can be initialized later in order by priority. 
00890  *
00891  *  If the ast_heap is not provided, the module's load function will be executed
00892  *  immediately */
00893 static enum ast_module_load_result load_resource(const char *resource_name, unsigned int global_symbols_only, struct ast_heap *resource_heap, int required)
00894 {
00895    struct ast_module *mod;
00896    enum ast_module_load_result res = AST_MODULE_LOAD_SUCCESS;
00897 
00898    if ((mod = find_resource(resource_name, 0))) {
00899       if (mod->flags.running) {
00900          ast_log(LOG_WARNING, "Module '%s' already exists.\n", resource_name);
00901          return AST_MODULE_LOAD_DECLINE;
00902       }
00903       if (global_symbols_only && !ast_test_flag(mod->info, AST_MODFLAG_GLOBAL_SYMBOLS))
00904          return AST_MODULE_LOAD_SKIP;
00905    } else {
00906 #ifdef LOADABLE_MODULES
00907       if (!(mod = load_dynamic_module(resource_name, global_symbols_only, resource_heap))) {
00908          /* don't generate a warning message during load_modules() */
00909          if (!global_symbols_only) {
00910             ast_log(LOG_WARNING, "Module '%s' could not be loaded.\n", resource_name);
00911             return required ? AST_MODULE_LOAD_FAILURE : AST_MODULE_LOAD_DECLINE;
00912          } else {
00913             return required ? AST_MODULE_LOAD_FAILURE : AST_MODULE_LOAD_SKIP;
00914          }
00915       }
00916 #else
00917       ast_log(LOG_WARNING, "Module '%s' could not be loaded.\n", resource_name);
00918       return required ? AST_MODULE_LOAD_FAILURE : AST_MODULE_LOAD_DECLINE;
00919 #endif
00920    }
00921 
00922    if (inspect_module(mod)) {
00923       ast_log(LOG_WARNING, "Module '%s' could not be loaded.\n", resource_name);
00924 #ifdef LOADABLE_MODULES
00925       unload_dynamic_module(mod);
00926 #endif
00927       return required ? AST_MODULE_LOAD_FAILURE : AST_MODULE_LOAD_DECLINE;
00928    }
00929 
00930    if (!mod->lib && mod->info->backup_globals && mod->info->backup_globals()) {
00931       ast_log(LOG_WARNING, "Module '%s' was unable to backup its global data.\n", resource_name);
00932       return required ? AST_MODULE_LOAD_FAILURE : AST_MODULE_LOAD_DECLINE;
00933    }
00934 
00935    mod->flags.declined = 0;
00936 
00937    if (resource_heap) {
00938       ast_heap_push(resource_heap, mod);
00939       res = AST_MODULE_LOAD_PRIORITY;
00940    } else {
00941       res = start_resource(mod);
00942    }
00943 
00944    return res;
00945 }
00946 
00947 int ast_load_resource(const char *resource_name)
00948 {
00949    int res;
00950    AST_LIST_LOCK(&module_list);
00951    res = load_resource(resource_name, 0, NULL, 0);
00952    if (!res) {
00953       ast_test_suite_event_notify("MODULE_LOAD", "Message: %s", resource_name);
00954    }
00955    AST_LIST_UNLOCK(&module_list);
00956 
00957    return res;
00958 }
00959 
00960 struct load_order_entry {
00961    char *resource;
00962    int required;
00963    AST_LIST_ENTRY(load_order_entry) entry;
00964 };
00965 
00966 AST_LIST_HEAD_NOLOCK(load_order, load_order_entry);
00967 
00968 static struct load_order_entry *add_to_load_order(const char *resource, struct load_order *load_order, int required)
00969 {
00970    struct load_order_entry *order;
00971 
00972    AST_LIST_TRAVERSE(load_order, order, entry) {
00973       if (!resource_name_match(order->resource, resource)) {
00974          /* Make sure we have the proper setting for the required field 
00975             (we might have both load= and required= lines in modules.conf) */
00976          order->required |= required;
00977          return NULL;
00978       }
00979    }
00980 
00981    if (!(order = ast_calloc(1, sizeof(*order))))
00982       return NULL;
00983 
00984    order->resource = ast_strdup(resource);
00985    order->required = required;
00986    AST_LIST_INSERT_TAIL(load_order, order, entry);
00987 
00988    return order;
00989 }
00990 
00991 static int mod_load_cmp(void *a, void *b)
00992 {
00993    struct ast_module *a_mod = (struct ast_module *) a;
00994    struct ast_module *b_mod = (struct ast_module *) b;
00995    int res = -1;
00996    /* if load_pri is not set, default is 128.  Lower is better*/
00997    unsigned char a_pri = ast_test_flag(a_mod->info, AST_MODFLAG_LOAD_ORDER) ? a_mod->info->load_pri : 128;
00998    unsigned char b_pri = ast_test_flag(b_mod->info, AST_MODFLAG_LOAD_ORDER) ? b_mod->info->load_pri : 128;
00999    if (a_pri == b_pri) {
01000       res = 0;
01001    } else if (a_pri < b_pri) {
01002       res = 1;
01003    }
01004    return res;
01005 }
01006 
01007 /*! loads modules in order by load_pri, updates mod_count 
01008    \return -1 on failure to load module, -2 on failure to load required module, otherwise 0
01009 */
01010 static int load_resource_list(struct load_order *load_order, unsigned int global_symbols, int *mod_count)
01011 {
01012    struct ast_heap *resource_heap;
01013    struct load_order_entry *order;
01014    struct ast_module *mod;
01015    int count = 0;
01016    int res = 0;
01017 
01018    if(!(resource_heap = ast_heap_create(8, mod_load_cmp, -1))) {
01019       return -1;
01020    }
01021 
01022    /* first, add find and add modules to heap */
01023    AST_LIST_TRAVERSE_SAFE_BEGIN(load_order, order, entry) {
01024       switch (load_resource(order->resource, global_symbols, resource_heap, order->required)) {
01025       case AST_MODULE_LOAD_SUCCESS:
01026       case AST_MODULE_LOAD_DECLINE:
01027          AST_LIST_REMOVE_CURRENT(entry);
01028          ast_free(order->resource);
01029          ast_free(order);
01030          break;
01031       case AST_MODULE_LOAD_FAILURE:
01032          ast_log(LOG_ERROR, "*** Failed to load module %s - %s\n", order->resource, order->required ? "Required" : "Not required");
01033          fprintf(stderr, "*** Failed to load module %s - %s\n", order->resource, order->required ? "Required" : "Not required");
01034          res = order->required ? -2 : -1;
01035          goto done;
01036       case AST_MODULE_LOAD_SKIP:
01037          break;
01038       case AST_MODULE_LOAD_PRIORITY:
01039          AST_LIST_REMOVE_CURRENT(entry);
01040          ast_free(order->resource);
01041          ast_free(order);
01042          break;
01043       }
01044    }
01045    AST_LIST_TRAVERSE_SAFE_END;
01046 
01047    /* second remove modules from heap sorted by priority */
01048    while ((mod = ast_heap_pop(resource_heap))) {
01049       switch (start_resource(mod)) {
01050       case AST_MODULE_LOAD_SUCCESS:
01051          count++;
01052       case AST_MODULE_LOAD_DECLINE:
01053          break;
01054       case AST_MODULE_LOAD_FAILURE:
01055          res = -1;
01056          goto done;
01057       case AST_MODULE_LOAD_SKIP:
01058       case AST_MODULE_LOAD_PRIORITY:
01059          break;
01060       }
01061    }
01062 
01063 done:
01064    if (mod_count) {
01065       *mod_count += count;
01066    }
01067    ast_heap_destroy(resource_heap);
01068 
01069    return res;
01070 }
01071 
01072 int load_modules(unsigned int preload_only)
01073 {
01074    struct ast_config *cfg;
01075    struct ast_module *mod;
01076    struct load_order_entry *order;
01077    struct ast_variable *v;
01078    unsigned int load_count;
01079    struct load_order load_order;
01080    int res = 0;
01081    struct ast_flags config_flags = { 0 };
01082    int modulecount = 0;
01083 
01084 #ifdef LOADABLE_MODULES
01085    struct dirent *dirent;
01086    DIR *dir;
01087 #endif
01088 
01089    /* all embedded modules have registered themselves by now */
01090    embedding = 0;
01091 
01092    ast_verb(1, "Asterisk Dynamic Loader Starting:\n");
01093 
01094    AST_LIST_HEAD_INIT_NOLOCK(&load_order);
01095 
01096    AST_LIST_LOCK(&module_list);
01097 
01098    if (embedded_module_list.first) {
01099       module_list.first = embedded_module_list.first;
01100       module_list.last = embedded_module_list.last;
01101       embedded_module_list.first = NULL;
01102    }
01103 
01104    cfg = ast_config_load2(AST_MODULE_CONFIG, "" /* core, can't reload */, config_flags);
01105    if (cfg == CONFIG_STATUS_FILEMISSING || cfg == CONFIG_STATUS_FILEINVALID) {
01106       ast_log(LOG_WARNING, "No '%s' found, no modules will be loaded.\n", AST_MODULE_CONFIG);
01107       goto done;
01108    }
01109 
01110    /* first, find all the modules we have been explicitly requested to load */
01111    for (v = ast_variable_browse(cfg, "modules"); v; v = v->next) {
01112       if (!strcasecmp(v->name, preload_only ? "preload" : "load")) {
01113          add_to_load_order(v->value, &load_order, 0);
01114       }
01115       if (!strcasecmp(v->name, preload_only ? "preload-require" : "require")) {
01116          /* Add the module to the list and make sure it's required */
01117          add_to_load_order(v->value, &load_order, 1);
01118          ast_debug(2, "Adding module to required list: %s (%s)\n", v->value, v->name);
01119       }
01120 
01121    }
01122 
01123    /* check if 'autoload' is on */
01124    if (!preload_only && ast_true(ast_variable_retrieve(cfg, "modules", "autoload"))) {
01125       /* if so, first add all the embedded modules that are not already running to the load order */
01126       AST_LIST_TRAVERSE(&module_list, mod, entry) {
01127          /* if it's not embedded, skip it */
01128          if (mod->lib)
01129             continue;
01130 
01131          if (mod->flags.running)
01132             continue;
01133 
01134          add_to_load_order(mod->resource, &load_order, 0);
01135       }
01136 
01137 #ifdef LOADABLE_MODULES
01138       /* if we are allowed to load dynamic modules, scan the directory for
01139          for all available modules and add them as well */
01140       if ((dir = opendir(ast_config_AST_MODULE_DIR))) {
01141          while ((dirent = readdir(dir))) {
01142             int ld = strlen(dirent->d_name);
01143 
01144             /* Must end in .so to load it.  */
01145 
01146             if (ld < 4)
01147                continue;
01148 
01149             if (strcasecmp(dirent->d_name + ld - 3, ".so"))
01150                continue;
01151 
01152             /* if there is already a module by this name in the module_list,
01153                skip this file */
01154             if (find_resource(dirent->d_name, 0))
01155                continue;
01156 
01157             add_to_load_order(dirent->d_name, &load_order, 0);
01158          }
01159 
01160          closedir(dir);
01161       } else {
01162          if (!ast_opt_quiet)
01163             ast_log(LOG_WARNING, "Unable to open modules directory '%s'.\n",
01164                ast_config_AST_MODULE_DIR);
01165       }
01166 #endif
01167    }
01168 
01169    /* now scan the config for any modules we are prohibited from loading and
01170       remove them from the load order */
01171    for (v = ast_variable_browse(cfg, "modules"); v; v = v->next) {
01172       if (strcasecmp(v->name, "noload"))
01173          continue;
01174 
01175       AST_LIST_TRAVERSE_SAFE_BEGIN(&load_order, order, entry) {
01176          if (!resource_name_match(order->resource, v->value)) {
01177             AST_LIST_REMOVE_CURRENT(entry);
01178             ast_free(order->resource);
01179             ast_free(order);
01180          }
01181       }
01182       AST_LIST_TRAVERSE_SAFE_END;
01183    }
01184 
01185    /* we are done with the config now, all the information we need is in the
01186       load_order list */
01187    ast_config_destroy(cfg);
01188 
01189    load_count = 0;
01190    AST_LIST_TRAVERSE(&load_order, order, entry)
01191       load_count++;
01192 
01193    if (load_count)
01194       ast_log(LOG_NOTICE, "%u modules will be loaded.\n", load_count);
01195 
01196    /* first, load only modules that provide global symbols */
01197    if ((res = load_resource_list(&load_order, 1, &modulecount)) < 0) {
01198       goto done;
01199    }
01200 
01201    /* now load everything else */
01202    if ((res = load_resource_list(&load_order, 0, &modulecount)) < 0) {
01203       goto done;
01204    }
01205 
01206 done:
01207    while ((order = AST_LIST_REMOVE_HEAD(&load_order, entry))) {
01208       ast_free(order->resource);
01209       ast_free(order);
01210    }
01211 
01212    AST_LIST_UNLOCK(&module_list);
01213    
01214    /* Tell manager clients that are aggressive at logging in that we're done
01215       loading modules. If there's a DNS problem in chan_sip, we might not
01216       even reach this */
01217    manager_event(EVENT_FLAG_SYSTEM, "ModuleLoadReport", "ModuleLoadStatus: Done\r\nModuleSelection: %s\r\nModuleCount: %d\r\n", preload_only ? "Preload" : "All", modulecount);
01218    
01219    return res;
01220 }
01221 
01222 void ast_update_use_count(void)
01223 {
01224    /* Notify any module monitors that the use count for a
01225       resource has changed */
01226    struct loadupdate *m;
01227 
01228    AST_LIST_LOCK(&updaters);
01229    AST_LIST_TRAVERSE(&updaters, m, entry)
01230       m->updater();
01231    AST_LIST_UNLOCK(&updaters);
01232 }
01233 
01234 int ast_update_module_list(int (*modentry)(const char *module, const char *description, int usecnt, const char *like),
01235             const char *like)
01236 {
01237    struct ast_module *cur;
01238    int unlock = -1;
01239    int total_mod_loaded = 0;
01240 
01241    if (AST_LIST_TRYLOCK(&module_list))
01242       unlock = 0;
01243  
01244    AST_LIST_TRAVERSE(&module_list, cur, entry) {
01245       total_mod_loaded += modentry(cur->resource, cur->info->description, cur->usecount, like);
01246    }
01247 
01248    if (unlock)
01249       AST_LIST_UNLOCK(&module_list);
01250 
01251    return total_mod_loaded;
01252 }
01253 
01254 /*! \brief Check if module exists */
01255 int ast_module_check(const char *name)
01256 {
01257    struct ast_module *cur;
01258 
01259    if (ast_strlen_zero(name))
01260       return 0;       /* FALSE */
01261 
01262    cur = find_resource(name, 1);
01263 
01264    return (cur != NULL);
01265 }
01266 
01267 
01268 int ast_loader_register(int (*v)(void))
01269 {
01270    struct loadupdate *tmp;
01271 
01272    if (!(tmp = ast_malloc(sizeof(*tmp))))
01273       return -1;
01274 
01275    tmp->updater = v;
01276    AST_LIST_LOCK(&updaters);
01277    AST_LIST_INSERT_HEAD(&updaters, tmp, entry);
01278    AST_LIST_UNLOCK(&updaters);
01279 
01280    return 0;
01281 }
01282 
01283 int ast_loader_unregister(int (*v)(void))
01284 {
01285    struct loadupdate *cur;
01286 
01287    AST_LIST_LOCK(&updaters);
01288    AST_LIST_TRAVERSE_SAFE_BEGIN(&updaters, cur, entry) {
01289       if (cur->updater == v)  {
01290          AST_LIST_REMOVE_CURRENT(entry);
01291          break;
01292       }
01293    }
01294    AST_LIST_TRAVERSE_SAFE_END;
01295    AST_LIST_UNLOCK(&updaters);
01296 
01297    return cur ? 0 : -1;
01298 }
01299 
01300 struct ast_module *ast_module_ref(struct ast_module *mod)
01301 {
01302    if (!mod) {
01303       return NULL;
01304    }
01305 
01306    ast_atomic_fetchadd_int(&mod->usecount, +1);
01307    ast_update_use_count();
01308 
01309    return mod;
01310 }
01311 
01312 void ast_module_unref(struct ast_module *mod)
01313 {
01314    if (!mod) {
01315       return;
01316    }
01317 
01318    ast_atomic_fetchadd_int(&mod->usecount, -1);
01319    ast_update_use_count();
01320 }

Generated on 27 Jan 2016 for Asterisk - The Open Source Telephony Project by  doxygen 1.6.1