res_stun_monitor.c File Reference

STUN Network Monitor. More...

#include "asterisk.h"
#include "asterisk/module.h"
#include "asterisk/event.h"
#include "asterisk/sched.h"
#include "asterisk/config.h"
#include "asterisk/stun.h"
#include "asterisk/netsock2.h"
#include "asterisk/lock.h"
#include "asterisk/acl.h"
#include <fcntl.h>

Include dependency graph for res_stun_monitor.c:

Go to the source code of this file.

Defines
#define	DEFAULT_MONITOR_REFRESH   30
Functions
static void	__reg_module (void)
static int	__reload (int startup)
static void	__unreg_module (void)
static int	load_config (int startup)
static int	load_module (void)
static int	reload (void)
static int	setup_stunaddr (const char *value)
static void	stun_close_sock (void)
static int	stun_monitor_request (const void *blarg)
static int	stun_start_monitor (void)
static void	stun_stop_monitor (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 = "STUN Network Monitor" , .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 = AST_BUILDOPT_SUM, .load = load_module, .unload = unload_module, .reload = reload, .load_pri = AST_MODPRI_CHANNEL_DEPEND }
struct {
struct sockaddr_in   external_addr
unsigned int   external_addr_known:1
ast_mutex_t   lock
unsigned int   monitor_enabled:1
unsigned int   refresh
const char *   server_hostname
unsigned int   stun_poll_failed_gripe:1
unsigned int   stun_port
int   stun_sock
}	args
static struct ast_module_info *	ast_module_info = &__mod_info
static struct ast_sched_context *	sched
static const char	stun_conf_file [] = "res_stun_monitor.conf"

---

Detailed Description

STUN Network Monitor.

Author:

David Vossel <dvossel@digium.com>

Definition in file res_stun_monitor.c.

---

Define Documentation

#define DEFAULT_MONITOR_REFRESH   30

Default refresh period in seconds

Definition at line 44 of file res_stun_monitor.c.

Referenced by load_config().

---

Function Documentation

static void __reg_module

(

void

)

[static]

Definition at line 398 of file res_stun_monitor.c.

static int __reload

(

int

startup

)

[static]

Definition at line 352 of file res_stun_monitor.c.

References args, ast_mutex_lock, ast_mutex_unlock, load_config(), stun_start_monitor(), and stun_stop_monitor().

Referenced by load_module(), and reload().

{
   int res;

   ast_mutex_lock(&args.lock);
   if (!(res = load_config(startup)) && args.monitor_enabled) {
      res = stun_start_monitor();
   }
   ast_mutex_unlock(&args.lock);

   if (res < 0 || !args.monitor_enabled) {
      stun_stop_monitor();
   }

   return res;
}

static void __unreg_module

(

void

)

[static]

Definition at line 398 of file res_stun_monitor.c.

static int load_config

(

int

startup

)

[static]

Definition at line 303 of file res_stun_monitor.c.

References args, ast_config_destroy(), ast_config_load2(), ast_log(), ast_set_flag, ast_variable_browse(), CONFIG_FLAG_FILEUNCHANGED, CONFIG_STATUS_FILEINVALID, CONFIG_STATUS_FILEUNCHANGED, DEFAULT_MONITOR_REFRESH, ast_variable::lineno, LOG_WARNING, ast_variable::name, ast_variable::next, setup_stunaddr(), stun_close_sock(), and ast_variable::value.

{
   struct ast_flags config_flags = { 0, };
   struct ast_config *cfg;
   struct ast_variable *v;

   if (!startup) {
      ast_set_flag(&config_flags, CONFIG_FLAG_FILEUNCHANGED);
   }

   cfg = ast_config_load2(stun_conf_file, "res_stun_monitor", config_flags);
   if (!cfg || cfg == CONFIG_STATUS_FILEINVALID) {
      ast_log(LOG_WARNING, "Unable to load config %s\n", stun_conf_file);
      return -1;
   }
   if (cfg == CONFIG_STATUS_FILEUNCHANGED) {
      return 0;
   }

   /* clean up any previous open socket */
   stun_close_sock();
   args.stun_poll_failed_gripe = 0;

   /* set defaults */
   args.monitor_enabled = 0;
   args.refresh = DEFAULT_MONITOR_REFRESH;

   for (v = ast_variable_browse(cfg, "general"); v; v = v->next) {
      if (!strcasecmp(v->name, "stunaddr")) {
         if (setup_stunaddr(v->value)) {
            ast_log(LOG_WARNING, "Invalid STUN server address: %s at line %d\n",
               v->value, v->lineno);
         }
      } else if (!strcasecmp(v->name, "stunrefresh")) {
         if ((sscanf(v->value, "%30u", &args.refresh) != 1) || !args.refresh) {
            ast_log(LOG_WARNING, "Invalid stunrefresh value '%s', must be an integer > 0 at line %d\n", v->value, v->lineno);
            args.refresh = DEFAULT_MONITOR_REFRESH;
         }
      } else {
         ast_log(LOG_WARNING, "Invalid config option %s at line %d\n",
            v->value, v->lineno);
      }
   }

   ast_config_destroy(cfg);

   return 0;
}

static int load_module

(

void

)

[static]

Definition at line 381 of file res_stun_monitor.c.

References __reload(), args, AST_MODULE_LOAD_DECLINE, AST_MODULE_LOAD_SUCCESS, ast_mutex_destroy, and ast_mutex_init.

{
   ast_mutex_init(&args.lock);
   args.stun_sock = -1;
   if (__reload(1)) {
      ast_mutex_destroy(&args.lock);
      return AST_MODULE_LOAD_DECLINE;
   }

   return AST_MODULE_LOAD_SUCCESS;
}

static int reload

(

void

)

[static]

Definition at line 369 of file res_stun_monitor.c.

References __reload().

{
   return __reload(0);
}

static int setup_stunaddr

(

const char *

value

)

[static]

Definition at line 253 of file res_stun_monitor.c.

References args, ast_free, ast_get_ip(), ast_log(), ast_sockaddr_split_hostport(), ast_strdup, ast_strdupa, ast_strlen_zero(), LOG_WARNING, ast_sockaddr::ss, and STANDARD_STUN_PORT.

Referenced by load_config().

{
   char *val;
   char *host_str;
   char *port_str;
   unsigned int port;
   struct ast_sockaddr stun_addr;

   if (ast_strlen_zero(value)) {
      /* Setting to an empty value disables STUN monitoring. */
      args.monitor_enabled = 0;
      return 0;
   }

   val = ast_strdupa(value);
   if (!ast_sockaddr_split_hostport(val, &host_str, &port_str, 0)
      || ast_strlen_zero(host_str)) {
      return -1;
   }

   /* Determine STUN port */
   if (ast_strlen_zero(port_str)
      || 1 != sscanf(port_str, "%30u", &port)) {
      port = STANDARD_STUN_PORT;
   }

   host_str = ast_strdup(host_str);
   if (!host_str) {
      return -1;
   }

   /* Lookup STUN address. */
   memset(&stun_addr, 0, sizeof(stun_addr));
   stun_addr.ss.ss_family = AF_INET;
   if (ast_get_ip(&stun_addr, host_str)) {
      ast_log(LOG_WARNING, "Unable to lookup STUN server '%s'\n", host_str);
      ast_free(host_str);
      return -1;
   }

   /* Save STUN server information. */
   ast_free((char *) args.server_hostname);
   args.server_hostname = host_str;
   args.stun_port = port;

   /* Enable STUN monitor */
   args.monitor_enabled = 1;
   return 0;
}

static void stun_close_sock

(

void

)

[static]

Definition at line 70 of file res_stun_monitor.c.

References args.

Referenced by load_config(), stun_monitor_request(), stun_start_monitor(), and stun_stop_monitor().

{
   if (0 <= args.stun_sock) {
      close(args.stun_sock);
      args.stun_sock = -1;
   }
}

static int stun_monitor_request

(

const void *

blarg

)

[static]

Definition at line 79 of file res_stun_monitor.c.

References args, ast_connect(), ast_event_destroy(), AST_EVENT_IE_END, AST_EVENT_NETWORK_CHANGE, ast_event_new(), ast_event_queue(), ast_get_ip(), ast_inet_ntoa(), ast_log(), ast_mutex_lock, ast_mutex_unlock, ast_sockaddr_set_port, ast_sockaddr_stringify(), ast_strdupa, ast_stun_request(), errno, LOG_ERROR, LOG_NOTICE, LOG_WARNING, ast_sockaddr::ss, and stun_close_sock().

Referenced by stun_start_monitor().

{
   int res;
   struct sockaddr_in answer;
   static const struct sockaddr_in no_addr = { 0, };

   ast_mutex_lock(&args.lock);
   if (!args.monitor_enabled) {
      goto monitor_request_cleanup;
   }

   if (args.stun_sock < 0) {
      struct ast_sockaddr stun_addr;

      /* STUN socket not open.  Refresh the server DNS address resolution. */
      if (!args.server_hostname) {
         /* No STUN hostname? */
         goto monitor_request_cleanup;
      }

      /* Lookup STUN address. */
      memset(&stun_addr, 0, sizeof(stun_addr));
      stun_addr.ss.ss_family = AF_INET;
      if (ast_get_ip(&stun_addr, args.server_hostname)) {
         /* Lookup failed. */
         ast_log(LOG_WARNING, "Unable to lookup STUN server '%s'\n",
            args.server_hostname);
         goto monitor_request_cleanup;
      }
      ast_sockaddr_set_port(&stun_addr, args.stun_port);

      /* open socket binding */
      args.stun_sock = socket(AF_INET, SOCK_DGRAM, 0);
      if (args.stun_sock < 0) {
         ast_log(LOG_WARNING, "Unable to create STUN socket: %s\n", strerror(errno));
         goto monitor_request_cleanup;
      }
      if (ast_connect(args.stun_sock, &stun_addr)) {
         ast_log(LOG_WARNING, "STUN Failed to connect to %s: %s\n",
            ast_sockaddr_stringify(&stun_addr), strerror(errno));
         stun_close_sock();
         goto monitor_request_cleanup;
      }
   }

   res = ast_stun_request(args.stun_sock, NULL, NULL, &answer);
   if (res) {
      /*
       * STUN request timed out or errored.
       *
       * Refresh the server DNS address resolution next time around.
       */
      if (!args.stun_poll_failed_gripe) {
         args.stun_poll_failed_gripe = 1;
         ast_log(LOG_WARNING, "STUN poll %s. Re-evaluating STUN server address.\n",
            res < 0 ? "failed" : "got no response");
      }
      stun_close_sock();
   } else {
      args.stun_poll_failed_gripe = 0;
      if (memcmp(&no_addr, &answer, sizeof(no_addr))
         && memcmp(&args.external_addr, &answer, sizeof(args.external_addr))) {
         const char *newaddr = ast_strdupa(ast_inet_ntoa(answer.sin_addr));
         int newport = ntohs(answer.sin_port);

         ast_log(LOG_NOTICE, "Old external address/port %s:%d now seen as %s:%d.\n",
            ast_inet_ntoa(args.external_addr.sin_addr),
            ntohs(args.external_addr.sin_port), newaddr, newport);

         args.external_addr = answer;

         if (args.external_addr_known) {
            struct ast_event *event;

            /*
             * The external address was already known, and has changed...
             * generate event.
             */
            event = ast_event_new(AST_EVENT_NETWORK_CHANGE, AST_EVENT_IE_END);
            if (!event) {
               ast_log(LOG_ERROR, "Could not create AST_EVENT_NETWORK_CHANGE event.\n");
            } else if (ast_event_queue(event)) {
               ast_event_destroy(event);
               ast_log(LOG_ERROR, "Could not queue AST_EVENT_NETWORK_CHANGE event.\n");
            }
         } else {
            /* this was the first external address we found, do not alert listeners
             * until this address changes to something else. */
            args.external_addr_known = 1;
         }
      }
   }

monitor_request_cleanup:
   /* always refresh this scheduler item.  It will be removed elsewhere when
    * it is supposed to go away */
   res = args.refresh * 1000;
   ast_mutex_unlock(&args.lock);

   return res;
}

static int stun_start_monitor

(

void

)

[static]

Definition at line 213 of file res_stun_monitor.c.

References args, ast_log(), ast_sched_add_variable(), ast_sched_context_create(), ast_sched_context_destroy(), ast_sched_start_thread(), LOG_ERROR, LOG_NOTICE, stun_close_sock(), and stun_monitor_request().

Referenced by __reload().

{
   /* if scheduler thread is not started, make sure to start it now */
   if (sched) {
      return 0; /* already started */
   }

   if (!(sched = ast_sched_context_create())) {
      ast_log(LOG_ERROR, "Failed to create stun monitor scheduler context\n");
      return -1;
   }

   if (ast_sched_start_thread(sched)) {
      ast_sched_context_destroy(sched);
      sched = NULL;
      stun_close_sock();
      return -1;
   }

   if (ast_sched_add_variable(sched, (args.refresh * 1000), stun_monitor_request, NULL, 1) < 0) {
      ast_log(LOG_ERROR, "Unable to schedule STUN network monitor \n");
      ast_sched_context_destroy(sched);
      sched = NULL;
      return -1;
   }

   ast_log(LOG_NOTICE, "STUN monitor started\n");

   return 0;
}

static void stun_stop_monitor

(

void

)

[static]

Definition at line 189 of file res_stun_monitor.c.

References args, ast_free, ast_log(), ast_mutex_lock, ast_mutex_unlock, ast_sched_context_destroy(), LOG_NOTICE, and stun_close_sock().

Referenced by __reload(), and unload_module().

{
   ast_mutex_lock(&args.lock);
   args.monitor_enabled = 0;
   ast_free((char *) args.server_hostname);
   args.server_hostname = NULL;
   stun_close_sock();
   ast_mutex_unlock(&args.lock);

   if (sched) {
      ast_sched_context_destroy(sched);
      sched = NULL;
      ast_log(LOG_NOTICE, "STUN monitor stopped\n");
   }
}

static int unload_module

(

void

)

[static]

Definition at line 374 of file res_stun_monitor.c.

References args, ast_mutex_destroy, and stun_stop_monitor().

{
   stun_stop_monitor();
   ast_mutex_destroy(&args.lock);
   return 0;
}

---

Variable Documentation

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_GLOBAL_SYMBOLS | AST_MODFLAG_LOAD_ORDER , .description = "STUN Network Monitor" , .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 = AST_BUILDOPT_SUM, .load = load_module, .unload = unload_module, .reload = reload, .load_pri = AST_MODPRI_CHANNEL_DEPEND } [static]

Definition at line 398 of file res_stun_monitor.c.

struct { ... } args [static]

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struct ast_module_info* ast_module_info = &__mod_info [static]

Definition at line 398 of file res_stun_monitor.c.

struct sockaddr_in external_addr

Current perceived external address.

Definition at line 53 of file res_stun_monitor.c.

unsigned int external_addr_known

TRUE if the perceived external address is valid/known.

Definition at line 65 of file res_stun_monitor.c.

ast_mutex_t lock

STUN monitor protection lock.

Definition at line 51 of file res_stun_monitor.c.

unsigned int monitor_enabled

TRUE if the STUN monitor is enabled.

Definition at line 63 of file res_stun_monitor.c.

unsigned int refresh

Number of seconds between polls to the STUN server for the external address.

Definition at line 59 of file res_stun_monitor.c.

Referenced by iax2_ack_registry().

struct ast_sched_context* sched [static]

Definition at line 47 of file res_stun_monitor.c.

const char* server_hostname

STUN server host name.

Definition at line 55 of file res_stun_monitor.c.

const char stun_conf_file[] = "res_stun_monitor.conf" [static]

Definition at line 46 of file res_stun_monitor.c.

unsigned int stun_poll_failed_gripe

TRUE if we have already griped about a STUN poll failing.

Definition at line 67 of file res_stun_monitor.c.

unsigned int stun_port

Port of STUN server to use

Definition at line 57 of file res_stun_monitor.c.

int stun_sock

Monitoring STUN socket.

Definition at line 61 of file res_stun_monitor.c.