dnsmgr.c File Reference

Background DNS update manager. More...

#include "asterisk.h"
#include "asterisk/_private.h"
#include <regex.h>
#include <signal.h>
#include "asterisk/module.h"
#include "asterisk/dnsmgr.h"
#include "asterisk/linkedlists.h"
#include "asterisk/utils.h"
#include "asterisk/config.h"
#include "asterisk/sched.h"
#include "asterisk/cli.h"
#include "asterisk/manager.h"
#include "asterisk/acl.h"

Include dependency graph for dnsmgr.c:

Go to the source code of this file.

Data Structures
struct	ast_dnsmgr_entry
struct	entry_list
struct	refresh_info

Macros
#define	REFRESH_DEFAULT   300

Functions
static void	__reg_module (void)
static void	__unreg_module (void)
int	ast_dnsmgr_changed (struct ast_dnsmgr_entry *entry)
	Check is see if a dnsmgr entry has changed. More...
struct ast_dnsmgr_entry *	ast_dnsmgr_get (const char *name, struct ast_sockaddr *result, const char *service)
	Allocate a new DNS manager entry. More...
struct ast_dnsmgr_entry *	ast_dnsmgr_get_family (const char *name, struct ast_sockaddr *result, const char *service, unsigned int family)
	Allocate a new DNS manager entry. More...
int	ast_dnsmgr_lookup (const char *name, struct ast_sockaddr *result, struct ast_dnsmgr_entry **dnsmgr, const char *service)
	Allocate and initialize a DNS manager entry. More...
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)
	Allocate and initialize a DNS manager entry, with update callback. More...
int	ast_dnsmgr_refresh (struct ast_dnsmgr_entry *entry)
	Force a refresh of a dnsmgr entry. More...
void	ast_dnsmgr_release (struct ast_dnsmgr_entry *entry)
	Free a DNS manager entry. More...
struct ast_module *	AST_MODULE_SELF_SYM (void)
static int	dnsmgr_refresh (struct ast_dnsmgr_entry *entry, int verbose)
void	dnsmgr_start_refresh (void)
static void *	do_refresh (void *data)
static int	do_reload (int loading)
static char *	handle_cli_refresh (struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
static char *	handle_cli_reload (struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
static char *	handle_cli_status (struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
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)
static int	load_module (void)
static int	refresh_list (const void *data)
static int	reload_module (void)
static int	unload_module (void)

Variables
static struct ast_module_info	__mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_GLOBAL_SYMBOLS | AST_MODFLAG_LOAD_ORDER , .description = "DNS Manager" , .key = "This paragraph is copyright (c) 2006 by Digium, Inc. \In order for your module to load, it must return this \key via a function called \"key\". Any code which \includes this paragraph must be licensed under the GNU \General Public License version 2 or later (at your \option). In addition to Digium's general reservations \of rights, Digium expressly reserves the right to \allow other parties to license this paragraph under \different terms. Any use of Digium, Inc. trademarks or \logos (including \"Asterisk\" or \"Digium\") without \express written permission of Digium, Inc. is prohibited.\n" , .buildopt_sum = "30ef0c93b36035ec78c9cfd712d36d9b" , .support_level = AST_MODULE_SUPPORT_CORE, .load = load_module, .unload = unload_module, .reload = reload_module, .load_pri = AST_MODPRI_CORE, .requires = "extconfig", }
static const struct ast_module_info *	ast_module_info = &__mod_info
static struct ast_cli_entry	cli_refresh = { .handler = handle_cli_refresh , .summary = "Performs an immediate refresh" ,}
static struct ast_cli_entry	cli_reload = { .handler = handle_cli_reload , .summary = "Reloads the DNS manager configuration" ,}
static struct ast_cli_entry	cli_status = { .handler = handle_cli_status , .summary = "Display the DNS manager status" ,}
static int	enabled
static struct entry_list	entry_list = { .first = NULL, .last = NULL, .lock = { PTHREAD_RWLOCK_INITIALIZER , NULL, {1, 0} } , }
static struct refresh_info	master_refresh_info
static int	refresh_interval
static ast_mutex_t	refresh_lock = { PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP , NULL, {1, 0} }
static int	refresh_sched = -1
static pthread_t	refresh_thread = AST_PTHREADT_NULL
static struct ast_sched_context *	sched

Detailed Description

Background DNS update manager.

Author

Kevin P. Fleming kpfle.nosp@m.ming.nosp@m.@digi.nosp@m.um.c.nosp@m.om

Bug:

There is a minor race condition. In the event that an IP address of a dnsmgr managed host changes, there is the potential for the consumer of that address to access the in_addr data at the same time that the dnsmgr thread is in the middle of updating it to the new address.

Definition in file dnsmgr.c.

Macro Definition Documentation

REFRESH_DEFAULT

#define REFRESH_DEFAULT   300

Definition at line 89 of file dnsmgr.c.

Referenced by do_reload().

Function Documentation

__reg_module()

static void __reg_module ( void  )

static

Definition at line 527 of file dnsmgr.c.

__unreg_module()

static void __unreg_module ( void  )

static

Definition at line 527 of file dnsmgr.c.

ast_dnsmgr_changed()

int ast_dnsmgr_changed

(

struct ast_dnsmgr_entry *

entry

)

Check is see if a dnsmgr entry has changed.

Return values

non-zero	if the dnsmgr entry has changed since the last call to this function
zero	if the dnsmgr entry has not changed since the last call to this function

Definition at line 247 of file dnsmgr.c.

References ast_mutex_lock, ast_mutex_unlock, ast_dnsmgr_entry::changed, and ast_dnsmgr_entry::lock.

Referenced by iax2_do_register().

{
   int changed;

   ast_mutex_lock(&entry->lock);

   changed = entry->changed;
   entry->changed = 0;

   ast_mutex_unlock(&entry->lock);

   return changed;
}

ast_dnsmgr_get()

struct ast_dnsmgr_entry* ast_dnsmgr_get	(	const char *	name,
		struct ast_sockaddr *	result,
		const char *	service
	)

Allocate a new DNS manager entry.

Parameters

name	the hostname
result	where the DNS manager should store the IP address as it refreshes it.
service

This function allocates a new DNS manager entry object, and fills it with the provided hostname and IP address. This function does not force an initial lookup of the IP address. So, generally, this should be used when the initial address is already known.

Returns

a DNS manager entry

Version

1.6.1 result changed from struct in_addr to struct sockaddr_in to store port number

1.8.0 result changed from struct ast_sockaddr_in to ast_sockaddr for IPv6 support

Definition at line 131 of file dnsmgr.c.

References ast_dnsmgr_get_family().

{
   return ast_dnsmgr_get_family(name, result, service, 0);
}

ast_dnsmgr_get_family()

struct ast_dnsmgr_entry* ast_dnsmgr_get_family	(	const char *	name,
		struct ast_sockaddr *	result,
		const char *	service,
		unsigned int	family
	)

Allocate a new DNS manager entry.

Parameters

name	the hostname
result	where the DNS manager should store the IP address as it refreshes it.
service
family	Address family to filter DNS addresses.

This function allocates a new DNS manager entry object, and fills it with the provided hostname and IP address. This function does not force an initial lookup of the IP address. So, generally, this should be used when the initial address is already known.

Returns

a DNS manager entry

Definition at line 106 of file dnsmgr.c.

References ast_calloc, ast_mutex_init, AST_RWLIST_INSERT_HEAD, AST_RWLIST_UNLOCK, AST_RWLIST_WRLOCK, ast_strlen_zero, ast_dnsmgr_entry::family, ast_dnsmgr_entry::lock, NULL, ast_dnsmgr_entry::result, and ast_dnsmgr_entry::service.

Referenced by ast_dnsmgr_get(), and internal_dnsmgr_lookup().

{
   struct ast_dnsmgr_entry *entry;
   int total_size = sizeof(*entry) + strlen(name) + (service ? strlen(service) + 1 : 0);

   if (!result || ast_strlen_zero(name) || !(entry = ast_calloc(1, total_size))) {
      return NULL;
   }

   entry->result = result;
   ast_mutex_init(&entry->lock);
   strcpy(entry->name, name);
   if (service) {
      entry->service = ((char *) entry) + sizeof(*entry) + strlen(name);
      strcpy(entry->service, service);
   }
   entry->family = family;

   AST_RWLIST_WRLOCK(&entry_list);
   AST_RWLIST_INSERT_HEAD(&entry_list, entry, list);
   AST_RWLIST_UNLOCK(&entry_list);

   return entry;
}

ast_dnsmgr_lookup()

int ast_dnsmgr_lookup	(	const char *	name,
		struct ast_sockaddr *	result,
		struct ast_dnsmgr_entry **	dnsmgr,
		const char *	service
	)

Allocate and initialize a DNS manager entry.

Parameters

name	the hostname
result	where to store the IP address as the DNS manager refreshes it. The address family is used as an input parameter to filter the returned addresses. If it is 0, both IPv4 and IPv6 addresses can be returned.
dnsmgr	Where to store the allocate DNS manager entry
service

Note

This function allocates a new DNS manager entry object, and fills it with the provided hostname and IP address. This function does force an initial lookup, so it may block for some period of time.

Return values

0	success
non-zero	failure

Version

1.6.1 result changed from struct in_addr to struct aockaddr_in to store port number

Definition at line 191 of file dnsmgr.c.

References internal_dnsmgr_lookup(), and NULL.

Referenced by __iax2_do_register_s(), build_peer(), iax2_append_register(), and transport_apply().

{
   return internal_dnsmgr_lookup(name, result, dnsmgr, service, NULL, NULL);
}

ast_dnsmgr_lookup_cb()

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
	)

Allocate and initialize a DNS manager entry, with update callback.

Parameters

name	the hostname
result	The addr which is intended to be updated in the update callback when DNS manager calls it on refresh. The address family is used as an input parameter to filter the returned addresses. If it is 0, both IPv4 and IPv6 addresses can be returned.
dnsmgr	Where to store the allocate DNS manager entry
service
func	The update callback function The update callback will be called when DNS manager detects that an IP address has been changed. Instead of updating the addr itself, DNS manager will call this callback function with the old and new addresses. It is the responsibility of the callback to perform any updates
data	A pointer to data that will be passed through to the callback function

Note

This function allocates a new DNS manager entry object, and fills it with the provided hostname and IP address. This function does force an initial lookup, so it may block for some period of time.

Return values

0	success
non-zero	failure

Definition at line 196 of file dnsmgr.c.

References internal_dnsmgr_lookup().

Referenced by __sip_subscribe_mwi_do(), build_peer(), and transmit_register().

{
   return internal_dnsmgr_lookup(name, result, dnsmgr, service, func, data);
}

ast_dnsmgr_refresh()

int ast_dnsmgr_refresh

(

struct ast_dnsmgr_entry *

entry

)

Force a refresh of a dnsmgr entry.

Return values

non-zero	if the result is different than the previous result
zero	if the result is the same as the previous result

Definition at line 239 of file dnsmgr.c.

References dnsmgr_refresh().

Referenced by build_peer(), iax2_do_register(), and sip_reg_timeout().

{
   return dnsmgr_refresh(entry, 0);
}

ast_dnsmgr_release()

void ast_dnsmgr_release

(

struct ast_dnsmgr_entry *

entry

)

Free a DNS manager entry.

Parameters

entry

the DNS manager entry to free

Returns

nothing

Definition at line 136 of file dnsmgr.c.

References ast_debug, ast_free, ast_mutex_destroy, AST_RWLIST_REMOVE, AST_RWLIST_UNLOCK, AST_RWLIST_WRLOCK, and ast_dnsmgr_entry::lock.

Referenced by __cleanup_registration(), __shutdown_mwi_subscription(), delete_users(), destroy_sip_transport_state(), match_and_cleanup_peer_sched(), and peer_destructor().

{
   if (!entry) {
      return;
   }

   AST_RWLIST_WRLOCK(&entry_list);
   AST_RWLIST_REMOVE(&entry_list, entry, list);
   AST_RWLIST_UNLOCK(&entry_list);
   ast_debug(6, "removing dns manager for '%s'\n", entry->name);

   ast_mutex_destroy(&entry->lock);
   ast_free(entry);
}

AST_MODULE_SELF_SYM()

struct ast_module* AST_MODULE_SELF_SYM

(

void

)

Definition at line 527 of file dnsmgr.c.

dnsmgr_refresh()

static int dnsmgr_refresh ( struct ast_dnsmgr_entry *  entry, int  verbose  )

static

Definition at line 204 of file dnsmgr.c.

References ast_debug, ast_get_ip_or_srv(), ast_log, ast_mutex_lock, ast_mutex_unlock, ast_sockaddr_cmp(), ast_sockaddr_copy(), ast_sockaddr_port, ast_sockaddr_set_port, ast_sockaddr_stringify(), ast_strdupa, ast_dnsmgr_entry::changed, ast_dnsmgr_entry::data, ast_dnsmgr_entry::family, ast_sockaddr::len, ast_dnsmgr_entry::lock, LOG_NOTICE, ast_dnsmgr_entry::result, ast_dnsmgr_entry::service, ast_sockaddr::ss, and ast_dnsmgr_entry::update_func.

Referenced by ast_dnsmgr_refresh(), and refresh_list().

{
   struct ast_sockaddr tmp = { .len = 0, };
   int changed = 0;

   ast_mutex_lock(&entry->lock);

   ast_debug(6, "refreshing '%s'\n", entry->name);

   tmp.ss.ss_family = entry->family;
   if (!ast_get_ip_or_srv(&tmp, entry->name, entry->service)) {
      if (!ast_sockaddr_port(&tmp)) {
         ast_sockaddr_set_port(&tmp, ast_sockaddr_port(entry->result));
      }
      if (ast_sockaddr_cmp(&tmp, entry->result)) {
         const char *old_addr = ast_strdupa(ast_sockaddr_stringify(entry->result));
         const char *new_addr = ast_strdupa(ast_sockaddr_stringify(&tmp));

         if (entry->update_func) {
            entry->update_func(entry->result, &tmp, entry->data);
         } else {
            ast_log(LOG_NOTICE, "dnssrv: host '%s' changed from %s to %s\n",
                  entry->name, old_addr, new_addr);

            ast_sockaddr_copy(entry->result, &tmp);
            changed = entry->changed = 1;
         }
      }
   }

   ast_mutex_unlock(&entry->lock);

   return changed;
}

dnsmgr_start_refresh()

void dnsmgr_start_refresh

(

void

)

Provided by dnsmgr.c

Definition at line 302 of file dnsmgr.c.

References ast_sched_add_variable(), AST_SCHED_DEL, do_reload(), refresh_list(), and refresh_sched.

Referenced by asterisk_daemon().

{
   if (refresh_sched > -1) {
      AST_SCHED_DEL(sched, refresh_sched);
      refresh_sched = ast_sched_add_variable(sched, 100, refresh_list, &master_refresh_info, 1);
   }
}

do_refresh()

static void* do_refresh ( void *  data )

static

Definition at line 261 of file dnsmgr.c.

References ast_sched_runq(), ast_sched_wait(), and NULL.

Referenced by do_reload().

{
   for (;;) {
      pthread_testcancel();
      usleep((ast_sched_wait(sched)*1000));
      pthread_testcancel();
      ast_sched_runq(sched);
   }
   return NULL;
}

do_reload()

static int do_reload ( int  loading )

static

Definition at line 450 of file dnsmgr.c.

References ast_config_destroy(), ast_config_load2(), ast_log, AST_MODFLAG_GLOBAL_SYMBOLS, AST_MODFLAG_LOAD_ORDER, AST_MODPRI_CORE, AST_MODULE_INFO(), AST_MODULE_SUPPORT_CORE, ast_mutex_lock, ast_mutex_unlock, ast_pthread_create_background, AST_PTHREADT_NULL, ast_sched_add_variable(), AST_SCHED_DEL, ast_true(), ast_variable_browse(), ASTERISK_GPL_KEY, config, CONFIG_FLAG_FILEUNCHANGED, CONFIG_STATUS_FILEINVALID, CONFIG_STATUS_FILEMISSING, CONFIG_STATUS_FILEUNCHANGED, do_refresh(), enabled, load_module(), LOG_ERROR, LOG_NOTICE, LOG_WARNING, ast_variable::name, ast_variable::next, NULL, REFRESH_DEFAULT, refresh_interval, refresh_list(), refresh_lock, refresh_sched, refresh_thread, reload(), reload_module(), unload_module(), and ast_variable::value.

Referenced by dnsmgr_start_refresh(), handle_cli_reload(), load_module(), and reload_module().

{
   struct ast_config *config;
   struct ast_variable *v;
   struct ast_flags config_flags = { loading ? 0 : CONFIG_FLAG_FILEUNCHANGED };
   int interval;
   int was_enabled;

   if ((config = ast_config_load2("dnsmgr.conf", "dnsmgr", config_flags)) == CONFIG_STATUS_FILEUNCHANGED) {
      return 0;
   }

   /* ensure that no refresh cycles run while the reload is in progress */
   ast_mutex_lock(&refresh_lock);

   /* reset defaults in preparation for reading config file */
   refresh_interval = REFRESH_DEFAULT;
   was_enabled = enabled;
   enabled = 0;

   if (config == CONFIG_STATUS_FILEMISSING || config == CONFIG_STATUS_FILEINVALID) {
      ast_mutex_unlock(&refresh_lock);
      return 0;
   }

   AST_SCHED_DEL(sched, refresh_sched);

   for (v = ast_variable_browse(config, "general"); v; v = v->next) {
      if (!strcasecmp(v->name, "enable")) {
         enabled = ast_true(v->value);
      } else if (!strcasecmp(v->name, "refreshinterval")) {
         if (sscanf(v->value, "%30d", &interval) < 1) {
            ast_log(LOG_WARNING, "Unable to convert '%s' to a numeric value.\n", v->value);
         } else if (interval < 0) {
            ast_log(LOG_WARNING, "Invalid refresh interval '%d' specified, using default\n", interval);
         } else {
            refresh_interval = interval;
         }
      }
   }
   ast_config_destroy(config);

   if (enabled && refresh_interval) {
      ast_log(LOG_NOTICE, "Managed DNS entries will be refreshed every %d seconds.\n", refresh_interval);
   }

   /* if this reload enabled the manager, create the background thread
      if it does not exist */
   if (enabled) {
      if (!was_enabled && (refresh_thread == AST_PTHREADT_NULL)) {
         if (ast_pthread_create_background(&refresh_thread, NULL, do_refresh, NULL) < 0) {
            ast_log(LOG_ERROR, "Unable to start refresh thread.\n");
         }
      }
      /* make a background refresh happen right away */
      refresh_sched = ast_sched_add_variable(sched, 100, refresh_list, &master_refresh_info, 1);
   /* if this reload disabled the manager and there is a background thread, kill it */
   } else if (!enabled && was_enabled && (refresh_thread != AST_PTHREADT_NULL)) {
      /* wake up the thread so it will exit */
      pthread_cancel(refresh_thread);
      pthread_kill(refresh_thread, SIGURG);
      pthread_join(refresh_thread, NULL);
      refresh_thread = AST_PTHREADT_NULL;
   }

   ast_mutex_unlock(&refresh_lock);

   return 0;
}

handle_cli_refresh()

static char* handle_cli_refresh ( struct ast_cli_entry *  e, int  cmd, struct ast_cli_args *  a  )

static

Definition at line 332 of file dnsmgr.c.

References ast_cli_args::argc, ast_cli_args::argv, ast_cli(), CLI_GENERATE, CLI_INIT, CLI_SHOWUSAGE, CLI_SUCCESS, ast_cli_entry::command, enabled, refresh_info::entries, entry_list, ast_cli_args::fd, refresh_info::filter, NULL, refresh_list(), refresh_info::regex_present, and ast_cli_entry::usage.

{
   struct refresh_info info = {
      .entries = &entry_list,
      .verbose = 1,
   };
   switch (cmd) {
   case CLI_INIT:
      e->command = "dnsmgr refresh";
      e->usage =
         "Usage: dnsmgr refresh [pattern]\n"
         "       Peforms an immediate refresh of the managed DNS entries.\n"
         "       Optional regular expression pattern is used to filter the entries to refresh.\n";
      return NULL;
   case CLI_GENERATE:
      return NULL;
   }

   if (!enabled) {
      ast_cli(a->fd, "DNS Manager is disabled.\n");
      return 0;
   }

   if (a->argc > 3) {
      return CLI_SHOWUSAGE;
   }

   if (a->argc == 3) {
      if (regcomp(&info.filter, a->argv[2], REG_EXTENDED | REG_NOSUB)) {
         return CLI_SHOWUSAGE;
      } else {
         info.regex_present = 1;
      }
   }

   refresh_list(&info);

   if (info.regex_present) {
      regfree(&info.filter);
   }

   return CLI_SUCCESS;
}

handle_cli_reload()

static char* handle_cli_reload ( struct ast_cli_entry *  e, int  cmd, struct ast_cli_args *  a  )

static

Definition at line 312 of file dnsmgr.c.

References ast_cli_args::argc, CLI_GENERATE, CLI_INIT, CLI_SHOWUSAGE, CLI_SUCCESS, ast_cli_entry::command, do_reload(), NULL, and ast_cli_entry::usage.

{
   switch (cmd) {
   case CLI_INIT:
      e->command = "dnsmgr reload";
      e->usage =
         "Usage: dnsmgr reload\n"
         "       Reloads the DNS manager configuration.\n";
      return NULL;
   case CLI_GENERATE:
      return NULL;
   }
   if (a->argc > 2) {
      return CLI_SHOWUSAGE;
   }

   do_reload(0);
   return CLI_SUCCESS;
}

handle_cli_status()

static char* handle_cli_status ( struct ast_cli_entry *  e, int  cmd, struct ast_cli_args *  a  )

static

Definition at line 376 of file dnsmgr.c.

References ast_cli_args::argc, ast_cli(), AST_RWLIST_RDLOCK, AST_RWLIST_TRAVERSE, AST_RWLIST_UNLOCK, CLI_GENERATE, CLI_INIT, CLI_SHOWUSAGE, CLI_SUCCESS, ast_cli_entry::command, enabled, ast_cli_args::fd, NULL, refresh_interval, and ast_cli_entry::usage.

{
   int count = 0;
   struct ast_dnsmgr_entry *entry;
   switch (cmd) {
   case CLI_INIT:
      e->command = "dnsmgr status";
      e->usage =
         "Usage: dnsmgr status\n"
         "       Displays the DNS manager status.\n";
      return NULL;
   case CLI_GENERATE:
      return NULL;
   }

   if (a->argc > 2) {
      return CLI_SHOWUSAGE;
   }

   ast_cli(a->fd, "DNS Manager: %s\n", enabled ? "enabled" : "disabled");
   ast_cli(a->fd, "Refresh Interval: %d seconds\n", refresh_interval);
   AST_RWLIST_RDLOCK(&entry_list);
   AST_RWLIST_TRAVERSE(&entry_list, entry, list)
      count++;
   AST_RWLIST_UNLOCK(&entry_list);
   ast_cli(a->fd, "Number of entries: %d\n", count);

   return CLI_SUCCESS;
}

internal_dnsmgr_lookup()

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  )

static

Definition at line 151 of file dnsmgr.c.

References ast_debug, ast_dnsmgr_get_family(), ast_get_ip_or_srv(), ast_sockaddr_parse(), ast_strlen_zero, ast_dnsmgr_entry::data, enabled, ast_dnsmgr_entry::family, PARSE_PORT_FORBID, and ast_sockaddr::ss.

Referenced by ast_dnsmgr_lookup(), and ast_dnsmgr_lookup_cb().

{
   unsigned int family;

   if (ast_strlen_zero(name) || !result || !dnsmgr) {
      return -1;
   }

   if (*dnsmgr && !strcasecmp((*dnsmgr)->name, name)) {
      return 0;
   }

   /* Lookup address family filter. */
   family = result->ss.ss_family;

   /*
    * If it's actually an IP address and not a name, there's no
    * need for a managed lookup.
    */
   if (ast_sockaddr_parse(result, name, PARSE_PORT_FORBID)) {
      return 0;
   }

   ast_debug(6, "doing dnsmgr_lookup for '%s'\n", name);

   /* do a lookup now but add a manager so it will automagically get updated in the background */
   ast_get_ip_or_srv(result, name, service);

   /* if dnsmgr is not enable don't bother adding an entry */
   if (!enabled) {
      return 0;
   }

   ast_debug(6, "adding dns manager for '%s'\n", name);
   *dnsmgr = ast_dnsmgr_get_family(name, result, service, family);
   (*dnsmgr)->update_func = func;
   (*dnsmgr)->data = data;
   return !*dnsmgr;
}

load_module()

static int load_module ( void  )

static

Definition at line 432 of file dnsmgr.c.

References ast_cli_register, ast_log, AST_MODULE_LOAD_FAILURE, AST_MODULE_LOAD_SUCCESS, ast_sched_context_create(), do_reload(), and LOG_ERROR.

Referenced by do_reload().

{
   if (!(sched = ast_sched_context_create())) {
      ast_log(LOG_ERROR, "Unable to create schedule context.\n");
      return AST_MODULE_LOAD_FAILURE;
   }
   ast_cli_register(&cli_reload);
   ast_cli_register(&cli_status);
   ast_cli_register(&cli_refresh);

   return do_reload(1) ? AST_MODULE_LOAD_FAILURE : AST_MODULE_LOAD_SUCCESS;
}

refresh_list()

static int refresh_list ( const void *  data )

static

Definition at line 272 of file dnsmgr.c.

References ast_debug, ast_log, ast_mutex_trylock, ast_mutex_unlock, AST_RWLIST_RDLOCK, AST_RWLIST_TRAVERSE, AST_RWLIST_UNLOCK, dnsmgr_refresh(), refresh_info::entries, refresh_info::filter, sip_to_pjsip::info(), LOG_WARNING, NULL, refresh_interval, refresh_lock, refresh_info::regex_present, and refresh_info::verbose.

Referenced by dnsmgr_start_refresh(), do_reload(), and handle_cli_refresh().

{
   struct refresh_info *info = (struct refresh_info *)data;
   struct ast_dnsmgr_entry *entry;

   /* if a refresh or reload is already in progress, exit now */
   if (ast_mutex_trylock(&refresh_lock)) {
      if (info->verbose) {
         ast_log(LOG_WARNING, "DNS Manager refresh already in progress.\n");
      }
      return -1;
   }

   ast_debug(6, "Refreshing DNS lookups.\n");
   AST_RWLIST_RDLOCK(info->entries);
   AST_RWLIST_TRAVERSE(info->entries, entry, list) {
      if (info->regex_present && regexec(&info->filter, entry->name, 0, NULL, 0)) {
         continue;
      }

      dnsmgr_refresh(entry, info->verbose);
   }
   AST_RWLIST_UNLOCK(info->entries);

   ast_mutex_unlock(&refresh_lock);

   /* automatically reschedule based on the interval */
   return refresh_interval * 1000;
}

reload_module()

static int reload_module ( void  )

static

Definition at line 445 of file dnsmgr.c.

References do_reload().

Referenced by do_reload().

{
   return do_reload(0);
}

unload_module()

static int unload_module ( void  )

static

Definition at line 410 of file dnsmgr.c.

References ast_cli_unregister(), ast_mutex_lock, ast_mutex_unlock, AST_PTHREADT_NULL, ast_sched_context_destroy(), NULL, refresh_lock, and refresh_thread.

Referenced by do_reload().

{
   ast_cli_unregister(&cli_reload);
   ast_cli_unregister(&cli_status);
   ast_cli_unregister(&cli_refresh);

   /* Destroy refresh thread. */
   ast_mutex_lock(&refresh_lock);
   if (refresh_thread != AST_PTHREADT_NULL) {
      /* wake up the thread so it will exit */
      pthread_cancel(refresh_thread);
      pthread_kill(refresh_thread, SIGURG);
      pthread_join(refresh_thread, NULL);
      refresh_thread = AST_PTHREADT_NULL;
   }
   ast_mutex_unlock(&refresh_lock);

   ast_sched_context_destroy(sched);

   return 0;
}

Variable Documentation

__mod_info

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_GLOBAL_SYMBOLS | AST_MODFLAG_LOAD_ORDER , .description = "DNS Manager" , .key = "This paragraph is copyright (c) 2006 by Digium, Inc. \In order for your module to load, it must return this \key via a function called \"key\". Any code which \includes this paragraph must be licensed under the GNU \General Public License version 2 or later (at your \option). In addition to Digium's general reservations \of rights, Digium expressly reserves the right to \allow other parties to license this paragraph under \different terms. Any use of Digium, Inc. trademarks or \logos (including \"Asterisk\" or \"Digium\") without \express written permission of Digium, Inc. is prohibited.\n" , .buildopt_sum = "30ef0c93b36035ec78c9cfd712d36d9b" , .support_level = AST_MODULE_SUPPORT_CORE, .load = load_module, .unload = unload_module, .reload = reload_module, .load_pri = AST_MODPRI_CORE, .requires = "extconfig", }

static

Definition at line 527 of file dnsmgr.c.

ast_module_info

const struct ast_module_info* ast_module_info = &__mod_info

static

Definition at line 527 of file dnsmgr.c.

cli_refresh

struct ast_cli_entry cli_refresh = { .handler = handle_cli_refresh , .summary = "Performs an immediate refresh" ,}

static

Definition at line 407 of file dnsmgr.c.

cli_reload

struct ast_cli_entry cli_reload = { .handler = handle_cli_reload , .summary = "Reloads the DNS manager configuration" ,}

static

Definition at line 406 of file dnsmgr.c.

cli_status

struct ast_cli_entry cli_status = { .handler = handle_cli_status , .summary = "Display the DNS manager status" ,}

static

Definition at line 408 of file dnsmgr.c.

enabled

int enabled

static

Definition at line 91 of file dnsmgr.c.

Referenced by __ast_http_load(), ast_ari_config_init(), ast_cel_check_enabled(), ast_context_set_autohints(), do_reload(), handle_cli_refresh(), handle_cli_status(), internal_dnsmgr_lookup(), load_module(), load_odbc_config(), osp_check_destination(), and process_config().

entry_list

struct entry_list entry_list = { .first = NULL, .last = NULL, .lock = { PTHREAD_RWLOCK_INITIALIZER , NULL, {1, 0} } , }

static

Referenced by handle_cli_refresh().

master_refresh_info

struct refresh_info master_refresh_info

static

Initial value:

= {
   .entries = &entry_list,
   .verbose = 0,
}

Definition at line 101 of file dnsmgr.c.

refresh_interval

int refresh_interval

static

Definition at line 92 of file dnsmgr.c.

Referenced by do_reload(), handle_cli_status(), and refresh_list().

refresh_lock

ast_mutex_t refresh_lock = { PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP , NULL, {1, 0} }

static

Definition at line 87 of file dnsmgr.c.

Referenced by do_reload(), refresh_list(), and unload_module().

refresh_sched

int refresh_sched = -1

static

Definition at line 63 of file dnsmgr.c.

Referenced by dnsmgr_start_refresh(), and do_reload().

refresh_thread

pthread_t refresh_thread = AST_PTHREADT_NULL

static

Definition at line 64 of file dnsmgr.c.

Referenced by do_reload(), and unload_module().

sched

struct ast_sched_context* sched

static

Definition at line 62 of file dnsmgr.c.