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00026 #include "asterisk.h"
00027
00028 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
00029
00030 #include <sys/types.h>
00031 #include <netinet/in.h>
00032 #include <sys/socket.h>
00033 #include <arpa/inet.h>
00034 #include <resolv.h>
00035 #include <stdio.h>
00036 #include <string.h>
00037 #include <unistd.h>
00038 #include <stdlib.h>
00039 #include <regex.h>
00040 #include <signal.h>
00041
00042 #include "asterisk/dnsmgr.h"
00043 #include "asterisk/linkedlists.h"
00044 #include "asterisk/utils.h"
00045 #include "asterisk/config.h"
00046 #include "asterisk/logger.h"
00047 #include "asterisk/sched.h"
00048 #include "asterisk/options.h"
00049 #include "asterisk/cli.h"
00050
00051 static struct sched_context *sched;
00052 static int refresh_sched = -1;
00053 static pthread_t refresh_thread = AST_PTHREADT_NULL;
00054
00055 struct ast_dnsmgr_entry {
00056
00057 struct in_addr *result;
00058
00059 struct in_addr last;
00060
00061 int changed:1;
00062 ast_mutex_t lock;
00063 AST_LIST_ENTRY(ast_dnsmgr_entry) list;
00064
00065 char name[1];
00066 };
00067
00068 static AST_LIST_HEAD_STATIC(entry_list, ast_dnsmgr_entry);
00069
00070 AST_MUTEX_DEFINE_STATIC(refresh_lock);
00071
00072 #define REFRESH_DEFAULT 300
00073
00074 static int enabled;
00075 static int refresh_interval;
00076
00077 struct refresh_info {
00078 struct entry_list *entries;
00079 int verbose;
00080 unsigned int regex_present:1;
00081 regex_t filter;
00082 };
00083
00084 static struct refresh_info master_refresh_info = {
00085 .entries = &entry_list,
00086 .verbose = 0,
00087 };
00088
00089 struct ast_dnsmgr_entry *ast_dnsmgr_get(const char *name, struct in_addr *result)
00090 {
00091 struct ast_dnsmgr_entry *entry;
00092
00093 if (!result || ast_strlen_zero(name) || !(entry = ast_calloc(1, sizeof(*entry) + strlen(name))))
00094 return NULL;
00095
00096 entry->result = result;
00097 ast_mutex_init(&entry->lock);
00098 strcpy(entry->name, name);
00099
00100 AST_LIST_LOCK(&entry_list);
00101 AST_LIST_INSERT_HEAD(&entry_list, entry, list);
00102 AST_LIST_UNLOCK(&entry_list);
00103
00104 return entry;
00105 }
00106
00107 void ast_dnsmgr_release(struct ast_dnsmgr_entry *entry)
00108 {
00109 if (!entry)
00110 return;
00111
00112 AST_LIST_LOCK(&entry_list);
00113 AST_LIST_REMOVE(&entry_list, entry, list);
00114 AST_LIST_UNLOCK(&entry_list);
00115 if (option_verbose > 3)
00116 ast_verbose(VERBOSE_PREFIX_4 "removing dns manager for '%s'\n", entry->name);
00117
00118 ast_mutex_destroy(&entry->lock);
00119 free(entry);
00120 }
00121
00122 int ast_dnsmgr_lookup(const char *name, struct in_addr *result, struct ast_dnsmgr_entry **dnsmgr)
00123 {
00124 if (ast_strlen_zero(name) || !result || !dnsmgr)
00125 return -1;
00126
00127 if (*dnsmgr && !strcasecmp((*dnsmgr)->name, name))
00128 return 0;
00129
00130 if (option_verbose > 3)
00131 ast_verbose(VERBOSE_PREFIX_4 "doing dnsmgr_lookup for '%s'\n", name);
00132
00133
00134
00135 if (inet_aton(name, result))
00136 return 0;
00137
00138
00139
00140 if (!enabled) {
00141 struct ast_hostent ahp;
00142 struct hostent *hp;
00143
00144 if ((hp = ast_gethostbyname(name, &ahp)))
00145 memcpy(result, hp->h_addr, sizeof(result));
00146 return 0;
00147 } else {
00148 if (option_verbose > 2)
00149 ast_verbose(VERBOSE_PREFIX_2 "adding dns manager for '%s'\n", name);
00150 *dnsmgr = ast_dnsmgr_get(name, result);
00151 return !*dnsmgr;
00152 }
00153 }
00154
00155
00156
00157
00158 static int dnsmgr_refresh(struct ast_dnsmgr_entry *entry, int verbose)
00159 {
00160 struct ast_hostent ahp;
00161 struct hostent *hp;
00162 char iabuf[INET_ADDRSTRLEN];
00163 char iabuf2[INET_ADDRSTRLEN];
00164 struct in_addr tmp;
00165 int changed = 0;
00166
00167 ast_mutex_lock(&entry->lock);
00168 if (verbose && (option_verbose > 2))
00169 ast_verbose(VERBOSE_PREFIX_2 "refreshing '%s'\n", entry->name);
00170
00171 if ((hp = ast_gethostbyname(entry->name, &ahp))) {
00172
00173 memcpy(&tmp, hp->h_addr, sizeof(tmp));
00174 if (tmp.s_addr != entry->last.s_addr) {
00175 ast_copy_string(iabuf, ast_inet_ntoa(entry->last), sizeof(iabuf));
00176 ast_copy_string(iabuf2, ast_inet_ntoa(tmp), sizeof(iabuf2));
00177 ast_log(LOG_NOTICE, "host '%s' changed from %s to %s\n",
00178 entry->name, iabuf, iabuf2);
00179 memcpy(entry->result, hp->h_addr, sizeof(entry->result));
00180 memcpy(&entry->last, hp->h_addr, sizeof(entry->last));
00181 changed = entry->changed = 1;
00182 }
00183
00184 }
00185 ast_mutex_unlock(&entry->lock);
00186 return changed;
00187 }
00188
00189 int ast_dnsmgr_refresh(struct ast_dnsmgr_entry *entry)
00190 {
00191 return dnsmgr_refresh(entry, 0);
00192 }
00193
00194
00195
00196
00197 int ast_dnsmgr_changed(struct ast_dnsmgr_entry *entry)
00198 {
00199 int changed;
00200
00201 ast_mutex_lock(&entry->lock);
00202
00203 changed = entry->changed;
00204 entry->changed = 0;
00205
00206 ast_mutex_unlock(&entry->lock);
00207
00208 return changed;
00209 }
00210
00211 static void *do_refresh(void *data)
00212 {
00213 for (;;) {
00214 pthread_testcancel();
00215 usleep((ast_sched_wait(sched)*1000));
00216 pthread_testcancel();
00217 ast_sched_runq(sched);
00218 }
00219 return NULL;
00220 }
00221
00222 static int refresh_list(void *data)
00223 {
00224 struct refresh_info *info = data;
00225 struct ast_dnsmgr_entry *entry;
00226
00227
00228 if (ast_mutex_trylock(&refresh_lock)) {
00229 if (info->verbose)
00230 ast_log(LOG_WARNING, "DNS Manager refresh already in progress.\n");
00231 return -1;
00232 }
00233
00234 if (option_verbose > 2)
00235 ast_verbose(VERBOSE_PREFIX_2 "Refreshing DNS lookups.\n");
00236 AST_LIST_LOCK(info->entries);
00237 AST_LIST_TRAVERSE(info->entries, entry, list) {
00238 if (info->regex_present && regexec(&info->filter, entry->name, 0, NULL, 0))
00239 continue;
00240
00241 dnsmgr_refresh(entry, info->verbose);
00242 }
00243 AST_LIST_UNLOCK(info->entries);
00244
00245 ast_mutex_unlock(&refresh_lock);
00246
00247
00248 return refresh_interval * 1000;
00249 }
00250
00251 void dnsmgr_start_refresh(void)
00252 {
00253 if (refresh_sched > -1) {
00254 ast_sched_del(sched, refresh_sched);
00255 refresh_sched = ast_sched_add_variable(sched, 100, refresh_list, &master_refresh_info, 1);
00256 }
00257 }
00258
00259 static int do_reload(int loading);
00260
00261 static int handle_cli_reload(int fd, int argc, char *argv[])
00262 {
00263 if (argc > 2)
00264 return RESULT_SHOWUSAGE;
00265
00266 do_reload(0);
00267 return 0;
00268 }
00269
00270 static int handle_cli_refresh(int fd, int argc, char *argv[])
00271 {
00272 struct refresh_info info = {
00273 .entries = &entry_list,
00274 .verbose = 1,
00275 };
00276
00277 if (argc > 3)
00278 return RESULT_SHOWUSAGE;
00279
00280 if (argc == 3) {
00281 if (regcomp(&info.filter, argv[2], REG_EXTENDED | REG_NOSUB))
00282 return RESULT_SHOWUSAGE;
00283 else
00284 info.regex_present = 1;
00285 }
00286
00287 refresh_list(&info);
00288
00289 if (info.regex_present)
00290 regfree(&info.filter);
00291
00292 return 0;
00293 }
00294
00295 static int handle_cli_status(int fd, int argc, char *argv[])
00296 {
00297 int count = 0;
00298 struct ast_dnsmgr_entry *entry;
00299
00300 if (argc > 2)
00301 return RESULT_SHOWUSAGE;
00302
00303 ast_cli(fd, "DNS Manager: %s\n", enabled ? "enabled" : "disabled");
00304 ast_cli(fd, "Refresh Interval: %d seconds\n", refresh_interval);
00305 AST_LIST_LOCK(&entry_list);
00306 AST_LIST_TRAVERSE(&entry_list, entry, list)
00307 count++;
00308 AST_LIST_UNLOCK(&entry_list);
00309 ast_cli(fd, "Number of entries: %d\n", count);
00310
00311 return 0;
00312 }
00313
00314 static struct ast_cli_entry cli_reload = {
00315 { "dnsmgr", "reload", NULL },
00316 handle_cli_reload, "Reloads the DNS manager configuration",
00317 "Usage: dnsmgr reload\n"
00318 " Reloads the DNS manager configuration.\n"
00319 };
00320
00321 static struct ast_cli_entry cli_refresh = {
00322 { "dnsmgr", "refresh", NULL },
00323 handle_cli_refresh, "Performs an immediate refresh",
00324 "Usage: dnsmgr refresh [pattern]\n"
00325 " Peforms an immediate refresh of the managed DNS entries.\n"
00326 " Optional regular expression pattern is used to filter the entries to refresh.\n",
00327 };
00328
00329 static struct ast_cli_entry cli_status = {
00330 { "dnsmgr", "status", NULL },
00331 handle_cli_status, "Display the DNS manager status",
00332 "Usage: dnsmgr status\n"
00333 " Displays the DNS manager status.\n"
00334 };
00335
00336 int dnsmgr_init(void)
00337 {
00338 if (!(sched = sched_context_create())) {
00339 ast_log(LOG_ERROR, "Unable to create schedule context.\n");
00340 return -1;
00341 }
00342 ast_cli_register(&cli_reload);
00343 ast_cli_register(&cli_status);
00344 return do_reload(1);
00345 }
00346
00347 int dnsmgr_reload(void)
00348 {
00349 return do_reload(0);
00350 }
00351
00352 static int do_reload(int loading)
00353 {
00354 struct ast_config *config;
00355 const char *interval_value;
00356 const char *enabled_value;
00357 int interval;
00358 int was_enabled;
00359 int res = -1;
00360
00361
00362 ast_mutex_lock(&refresh_lock);
00363
00364
00365 refresh_interval = REFRESH_DEFAULT;
00366 was_enabled = enabled;
00367 enabled = 0;
00368
00369 if (refresh_sched > -1)
00370 ast_sched_del(sched, refresh_sched);
00371
00372 if ((config = ast_config_load("dnsmgr.conf"))) {
00373 if ((enabled_value = ast_variable_retrieve(config, "general", "enable"))) {
00374 enabled = ast_true(enabled_value);
00375 }
00376 if ((interval_value = ast_variable_retrieve(config, "general", "refreshinterval"))) {
00377 if (sscanf(interval_value, "%d", &interval) < 1)
00378 ast_log(LOG_WARNING, "Unable to convert '%s' to a numeric value.\n", interval_value);
00379 else if (interval < 0)
00380 ast_log(LOG_WARNING, "Invalid refresh interval '%d' specified, using default\n", interval);
00381 else
00382 refresh_interval = interval;
00383 }
00384 ast_config_destroy(config);
00385 }
00386
00387 if (enabled && refresh_interval)
00388 ast_log(LOG_NOTICE, "Managed DNS entries will be refreshed every %d seconds.\n", refresh_interval);
00389
00390
00391
00392 if (enabled) {
00393 if (!was_enabled && (refresh_thread == AST_PTHREADT_NULL)) {
00394 if (ast_pthread_create_background(&refresh_thread, NULL, do_refresh, NULL) < 0) {
00395 ast_log(LOG_ERROR, "Unable to start refresh thread.\n");
00396 }
00397 ast_cli_register(&cli_refresh);
00398 }
00399
00400 refresh_sched = ast_sched_add_variable(sched, 100, refresh_list, &master_refresh_info, 1);
00401 res = 0;
00402 }
00403
00404
00405 else if (!enabled && was_enabled && (refresh_thread != AST_PTHREADT_NULL)) {
00406
00407 pthread_cancel(refresh_thread);
00408 pthread_kill(refresh_thread, SIGURG);
00409 pthread_join(refresh_thread, NULL);
00410 refresh_thread = AST_PTHREADT_NULL;
00411 ast_cli_unregister(&cli_refresh);
00412 res = 0;
00413 }
00414 else
00415 res = 0;
00416
00417 ast_mutex_unlock(&refresh_lock);
00418
00419 return res;
00420 }