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00031 #include "asterisk.h"
00032
00033 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 354884 $")
00034
00035 #include "asterisk/_private.h"
00036 #include <regex.h>
00037 #include <signal.h>
00038
00039 #include "asterisk/dnsmgr.h"
00040 #include "asterisk/linkedlists.h"
00041 #include "asterisk/utils.h"
00042 #include "asterisk/config.h"
00043 #include "asterisk/sched.h"
00044 #include "asterisk/cli.h"
00045 #include "asterisk/manager.h"
00046 #include "asterisk/acl.h"
00047
00048 static struct sched_context *sched;
00049 static int refresh_sched = -1;
00050 static pthread_t refresh_thread = AST_PTHREADT_NULL;
00051
00052 struct ast_dnsmgr_entry {
00053
00054 struct ast_sockaddr *result;
00055
00056 char *service;
00057
00058 unsigned int family;
00059
00060 unsigned int changed:1;
00061
00062 void *data;
00063
00064 dns_update_func update_func;
00065 ast_mutex_t lock;
00066 AST_RWLIST_ENTRY(ast_dnsmgr_entry) list;
00067
00068 char name[1];
00069 };
00070
00071 static AST_RWLIST_HEAD_STATIC(entry_list, ast_dnsmgr_entry);
00072
00073 AST_MUTEX_DEFINE_STATIC(refresh_lock);
00074
00075 #define REFRESH_DEFAULT 300
00076
00077 static int enabled;
00078 static int refresh_interval;
00079
00080 struct refresh_info {
00081 struct entry_list *entries;
00082 int verbose;
00083 unsigned int regex_present:1;
00084 regex_t filter;
00085 };
00086
00087 static struct refresh_info master_refresh_info = {
00088 .entries = &entry_list,
00089 .verbose = 0,
00090 };
00091
00092 struct ast_dnsmgr_entry *ast_dnsmgr_get_family(const char *name, struct ast_sockaddr *result, const char *service, unsigned int family)
00093 {
00094 struct ast_dnsmgr_entry *entry;
00095 int total_size = sizeof(*entry) + strlen(name) + (service ? strlen(service) + 1 : 0);
00096
00097 if (!result || ast_strlen_zero(name) || !(entry = ast_calloc(1, total_size))) {
00098 return NULL;
00099 }
00100
00101 entry->result = result;
00102 ast_mutex_init(&entry->lock);
00103 strcpy(entry->name, name);
00104 if (service) {
00105 entry->service = ((char *) entry) + sizeof(*entry) + strlen(name);
00106 strcpy(entry->service, service);
00107 }
00108 entry->family = family;
00109
00110 AST_RWLIST_WRLOCK(&entry_list);
00111 AST_RWLIST_INSERT_HEAD(&entry_list, entry, list);
00112 AST_RWLIST_UNLOCK(&entry_list);
00113
00114 return entry;
00115 }
00116
00117 struct ast_dnsmgr_entry *ast_dnsmgr_get(const char *name, struct ast_sockaddr *result, const char *service)
00118 {
00119 return ast_dnsmgr_get_family(name, result, service, 0);
00120 }
00121
00122 void ast_dnsmgr_release(struct ast_dnsmgr_entry *entry)
00123 {
00124 if (!entry)
00125 return;
00126
00127 AST_RWLIST_WRLOCK(&entry_list);
00128 AST_RWLIST_REMOVE(&entry_list, entry, list);
00129 AST_RWLIST_UNLOCK(&entry_list);
00130 ast_verb(4, "removing dns manager for '%s'\n", entry->name);
00131
00132 ast_mutex_destroy(&entry->lock);
00133 ast_free(entry);
00134 }
00135
00136 static int internal_dnsmgr_lookup(const char *name, struct ast_sockaddr *result, struct ast_dnsmgr_entry **dnsmgr, const char *service, dns_update_func func, void *data)
00137 {
00138 unsigned int family;
00139
00140 if (ast_strlen_zero(name) || !result || !dnsmgr) {
00141 return -1;
00142 }
00143
00144 if (*dnsmgr && !strcasecmp((*dnsmgr)->name, name)) {
00145 return 0;
00146 }
00147
00148
00149 family = result->ss.ss_family;
00150
00151
00152
00153
00154
00155 if (ast_sockaddr_parse(result, name, PARSE_PORT_FORBID)) {
00156 return 0;
00157 }
00158
00159 ast_verb(4, "doing dnsmgr_lookup for '%s'\n", name);
00160
00161
00162 ast_get_ip_or_srv(result, name, service);
00163
00164
00165 if (!enabled) {
00166 return 0;
00167 }
00168
00169 ast_verb(3, "adding dns manager for '%s'\n", name);
00170 *dnsmgr = ast_dnsmgr_get_family(name, result, service, family);
00171 (*dnsmgr)->update_func = func;
00172 (*dnsmgr)->data = data;
00173 return !*dnsmgr;
00174 }
00175
00176 int ast_dnsmgr_lookup(const char *name, struct ast_sockaddr *result, struct ast_dnsmgr_entry **dnsmgr, const char *service)
00177 {
00178 return internal_dnsmgr_lookup(name, result, dnsmgr, service, NULL, NULL);
00179 }
00180
00181 int ast_dnsmgr_lookup_cb(const char *name, struct ast_sockaddr *result, struct ast_dnsmgr_entry **dnsmgr, const char *service, dns_update_func func, void *data)
00182 {
00183 return internal_dnsmgr_lookup(name, result, dnsmgr, service, func, data);
00184 }
00185
00186
00187
00188
00189 static int dnsmgr_refresh(struct ast_dnsmgr_entry *entry, int verbose)
00190 {
00191 struct ast_sockaddr tmp = { .len = 0, };
00192 int changed = 0;
00193
00194 ast_mutex_lock(&entry->lock);
00195
00196 if (verbose) {
00197 ast_verb(3, "refreshing '%s'\n", entry->name);
00198 }
00199
00200 tmp.ss.ss_family = entry->family;
00201 if (!ast_get_ip_or_srv(&tmp, entry->name, entry->service)) {
00202 if (!ast_sockaddr_port(&tmp)) {
00203 ast_sockaddr_set_port(&tmp, ast_sockaddr_port(entry->result));
00204 }
00205 if (ast_sockaddr_cmp(&tmp, entry->result)) {
00206 const char *old_addr = ast_strdupa(ast_sockaddr_stringify(entry->result));
00207 const char *new_addr = ast_strdupa(ast_sockaddr_stringify(&tmp));
00208
00209 if (entry->update_func) {
00210 entry->update_func(entry->result, &tmp, entry->data);
00211 } else {
00212 ast_log(LOG_NOTICE, "dnssrv: host '%s' changed from %s to %s\n",
00213 entry->name, old_addr, new_addr);
00214
00215 ast_sockaddr_copy(entry->result, &tmp);
00216 changed = entry->changed = 1;
00217 }
00218 }
00219 }
00220
00221 ast_mutex_unlock(&entry->lock);
00222
00223 return changed;
00224 }
00225
00226 int ast_dnsmgr_refresh(struct ast_dnsmgr_entry *entry)
00227 {
00228 return dnsmgr_refresh(entry, 0);
00229 }
00230
00231
00232
00233
00234 int ast_dnsmgr_changed(struct ast_dnsmgr_entry *entry)
00235 {
00236 int changed;
00237
00238 ast_mutex_lock(&entry->lock);
00239
00240 changed = entry->changed;
00241 entry->changed = 0;
00242
00243 ast_mutex_unlock(&entry->lock);
00244
00245 return changed;
00246 }
00247
00248 static void *do_refresh(void *data)
00249 {
00250 for (;;) {
00251 pthread_testcancel();
00252 usleep((ast_sched_wait(sched)*1000));
00253 pthread_testcancel();
00254 ast_sched_runq(sched);
00255 }
00256 return NULL;
00257 }
00258
00259 static int refresh_list(const void *data)
00260 {
00261 struct refresh_info *info = (struct refresh_info *)data;
00262 struct ast_dnsmgr_entry *entry;
00263
00264
00265 if (ast_mutex_trylock(&refresh_lock)) {
00266 if (info->verbose)
00267 ast_log(LOG_WARNING, "DNS Manager refresh already in progress.\n");
00268 return -1;
00269 }
00270
00271 ast_verb(3, "Refreshing DNS lookups.\n");
00272 AST_RWLIST_RDLOCK(info->entries);
00273 AST_RWLIST_TRAVERSE(info->entries, entry, list) {
00274 if (info->regex_present && regexec(&info->filter, entry->name, 0, NULL, 0))
00275 continue;
00276
00277 dnsmgr_refresh(entry, info->verbose);
00278 }
00279 AST_RWLIST_UNLOCK(info->entries);
00280
00281 ast_mutex_unlock(&refresh_lock);
00282
00283
00284 return refresh_interval * 1000;
00285 }
00286
00287 void dnsmgr_start_refresh(void)
00288 {
00289 if (refresh_sched > -1) {
00290 AST_SCHED_DEL(sched, refresh_sched);
00291 refresh_sched = ast_sched_add_variable(sched, 100, refresh_list, &master_refresh_info, 1);
00292 }
00293 }
00294
00295 static int do_reload(int loading);
00296
00297 static char *handle_cli_reload(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
00298 {
00299 switch (cmd) {
00300 case CLI_INIT:
00301 e->command = "dnsmgr reload";
00302 e->usage =
00303 "Usage: dnsmgr reload\n"
00304 " Reloads the DNS manager configuration.\n";
00305 return NULL;
00306 case CLI_GENERATE:
00307 return NULL;
00308 }
00309 if (a->argc > 2)
00310 return CLI_SHOWUSAGE;
00311
00312 do_reload(0);
00313 return CLI_SUCCESS;
00314 }
00315
00316 static char *handle_cli_refresh(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
00317 {
00318 struct refresh_info info = {
00319 .entries = &entry_list,
00320 .verbose = 1,
00321 };
00322 switch (cmd) {
00323 case CLI_INIT:
00324 e->command = "dnsmgr refresh";
00325 e->usage =
00326 "Usage: dnsmgr refresh [pattern]\n"
00327 " Peforms an immediate refresh of the managed DNS entries.\n"
00328 " Optional regular expression pattern is used to filter the entries to refresh.\n";
00329 return NULL;
00330 case CLI_GENERATE:
00331 return NULL;
00332 }
00333
00334 if (!enabled) {
00335 ast_cli(a->fd, "DNS Manager is disabled.\n");
00336 return 0;
00337 }
00338
00339 if (a->argc > 3) {
00340 return CLI_SHOWUSAGE;
00341 }
00342
00343 if (a->argc == 3) {
00344 if (regcomp(&info.filter, a->argv[2], REG_EXTENDED | REG_NOSUB)) {
00345 return CLI_SHOWUSAGE;
00346 } else {
00347 info.regex_present = 1;
00348 }
00349 }
00350
00351 refresh_list(&info);
00352
00353 if (info.regex_present) {
00354 regfree(&info.filter);
00355 }
00356
00357 return CLI_SUCCESS;
00358 }
00359
00360 static char *handle_cli_status(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
00361 {
00362 int count = 0;
00363 struct ast_dnsmgr_entry *entry;
00364 switch (cmd) {
00365 case CLI_INIT:
00366 e->command = "dnsmgr status";
00367 e->usage =
00368 "Usage: dnsmgr status\n"
00369 " Displays the DNS manager status.\n";
00370 return NULL;
00371 case CLI_GENERATE:
00372 return NULL;
00373 }
00374
00375 if (a->argc > 2)
00376 return CLI_SHOWUSAGE;
00377
00378 ast_cli(a->fd, "DNS Manager: %s\n", enabled ? "enabled" : "disabled");
00379 ast_cli(a->fd, "Refresh Interval: %d seconds\n", refresh_interval);
00380 AST_RWLIST_RDLOCK(&entry_list);
00381 AST_RWLIST_TRAVERSE(&entry_list, entry, list)
00382 count++;
00383 AST_RWLIST_UNLOCK(&entry_list);
00384 ast_cli(a->fd, "Number of entries: %d\n", count);
00385
00386 return CLI_SUCCESS;
00387 }
00388
00389 static struct ast_cli_entry cli_reload = AST_CLI_DEFINE(handle_cli_reload, "Reloads the DNS manager configuration");
00390 static struct ast_cli_entry cli_refresh = AST_CLI_DEFINE(handle_cli_refresh, "Performs an immediate refresh");
00391 static struct ast_cli_entry cli_status = AST_CLI_DEFINE(handle_cli_status, "Display the DNS manager status");
00392
00393 int dnsmgr_init(void)
00394 {
00395 if (!(sched = sched_context_create())) {
00396 ast_log(LOG_ERROR, "Unable to create schedule context.\n");
00397 return -1;
00398 }
00399 ast_cli_register(&cli_reload);
00400 ast_cli_register(&cli_status);
00401 ast_cli_register(&cli_refresh);
00402 return do_reload(1);
00403 }
00404
00405 int dnsmgr_reload(void)
00406 {
00407 return do_reload(0);
00408 }
00409
00410 static int do_reload(int loading)
00411 {
00412 struct ast_config *config;
00413 struct ast_flags config_flags = { loading ? 0 : CONFIG_FLAG_FILEUNCHANGED };
00414 const char *interval_value;
00415 const char *enabled_value;
00416 int interval;
00417 int was_enabled;
00418 int res = -1;
00419
00420 config = ast_config_load2("dnsmgr.conf", "dnsmgr", config_flags);
00421 if (config == CONFIG_STATUS_FILEMISSING || config == CONFIG_STATUS_FILEUNCHANGED || config == CONFIG_STATUS_FILEINVALID) {
00422 return 0;
00423 }
00424
00425
00426 ast_mutex_lock(&refresh_lock);
00427
00428
00429 refresh_interval = REFRESH_DEFAULT;
00430 was_enabled = enabled;
00431 enabled = 0;
00432
00433 AST_SCHED_DEL(sched, refresh_sched);
00434
00435 if (config) {
00436 if ((enabled_value = ast_variable_retrieve(config, "general", "enable"))) {
00437 enabled = ast_true(enabled_value);
00438 }
00439 if ((interval_value = ast_variable_retrieve(config, "general", "refreshinterval"))) {
00440 if (sscanf(interval_value, "%30d", &interval) < 1)
00441 ast_log(LOG_WARNING, "Unable to convert '%s' to a numeric value.\n", interval_value);
00442 else if (interval < 0)
00443 ast_log(LOG_WARNING, "Invalid refresh interval '%d' specified, using default\n", interval);
00444 else
00445 refresh_interval = interval;
00446 }
00447 ast_config_destroy(config);
00448 }
00449
00450 if (enabled && refresh_interval)
00451 ast_log(LOG_NOTICE, "Managed DNS entries will be refreshed every %d seconds.\n", refresh_interval);
00452
00453
00454
00455 if (enabled) {
00456 if (!was_enabled && (refresh_thread == AST_PTHREADT_NULL)) {
00457 if (ast_pthread_create_background(&refresh_thread, NULL, do_refresh, NULL) < 0) {
00458 ast_log(LOG_ERROR, "Unable to start refresh thread.\n");
00459 }
00460 }
00461
00462 refresh_sched = ast_sched_add_variable(sched, 100, refresh_list, &master_refresh_info, 1);
00463 res = 0;
00464 }
00465
00466
00467 else if (!enabled && was_enabled && (refresh_thread != AST_PTHREADT_NULL)) {
00468
00469 pthread_cancel(refresh_thread);
00470 pthread_kill(refresh_thread, SIGURG);
00471 pthread_join(refresh_thread, NULL);
00472 refresh_thread = AST_PTHREADT_NULL;
00473 res = 0;
00474 }
00475 else
00476 res = 0;
00477
00478 ast_mutex_unlock(&refresh_lock);
00479 manager_event(EVENT_FLAG_SYSTEM, "Reload", "Module: DNSmgr\r\nStatus: %s\r/nMessage: DNSmgr reload Requested\r\n", enabled ? "Enabled" : "Disabled");
00480
00481 return res;
00482 }