res_stun_monitor.c File Reference

STUN Network Monitor. More...

#include "asterisk.h"
#include "asterisk/module.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 "asterisk/cli.h"
#include "asterisk/json.h"
#include "asterisk/stasis.h"
#include "asterisk/stasis_system.h"
#include "asterisk/astobj2.h"
#include <fcntl.h>

Include dependency graph for res_stun_monitor.c:

Go to the source code of this file.

Macros
#define	DATALN   "%-25s %-5u %-7u %-8d %-7s %-16s %-d\n"
#define	DEFAULT_MONITOR_REFRESH   30
#define	DEFAULT_RETRIES   3
#define	HEADER   "%-25s %-5s %-7s %-8s %-7s %-16s %-s\n"

Functions
static void	__reg_module (void)
static int	__reload (int startup)
static void	__unreg_module (void)
static void	_stun_show_status (int fd)
	Execute stun show status command. More...
struct ast_module *	AST_MODULE_SELF_SYM (void)
static char *	handle_cli_stun_show_status (struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
static int	load_config (int startup)
static int	load_module (void)
static int	reload (void)
static int	setup_stunaddr (const char *value, int reload)
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, .support_level = AST_MODULE_SUPPORT_CORE, .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 const struct ast_module_info *	ast_module_info = &__mod_info
static struct ast_cli_entry	cli_stun []
static struct ast_sched_context *	sched
static const char	stun_conf_file [] = "res_stun_monitor.conf"

Detailed Description

STUN Network Monitor.

Author

David Vossel dvoss.nosp@m.el@d.nosp@m.igium.nosp@m..com

Definition in file res_stun_monitor.c.

Macro Definition Documentation

DATALN

#define DATALN   "%-25s %-5u %-7u %-8d %-7s %-16s %-d\n"

Referenced by _stun_show_status().

DEFAULT_MONITOR_REFRESH

#define DEFAULT_MONITOR_REFRESH   30

Default refresh period in seconds

Definition at line 47 of file res_stun_monitor.c.

Referenced by load_config().

DEFAULT_RETRIES

#define DEFAULT_RETRIES   3

retries shown in stun show status matching static retries in stun.c

Definition at line 48 of file res_stun_monitor.c.

Referenced by _stun_show_status().

HEADER

#define HEADER   "%-25s %-5s %-7s %-8s %-7s %-16s %-s\n"

Referenced by _stun_show_status().

Function Documentation

__reg_module()

static void __reg_module ( void  )

static

Definition at line 487 of file res_stun_monitor.c.

__reload()

static int __reload ( int  startup )

static

Definition at line 433 of file res_stun_monitor.c.

References args, ast_mutex_lock, ast_mutex_unlock, load_config(), reload(), 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;
}

__unreg_module()

static void __unreg_module ( void  )

static

Definition at line 487 of file res_stun_monitor.c.

_stun_show_status()

static void _stun_show_status ( int  fd )

static

Execute stun show status command.

we only have one stun server, but start to play well with more

Definition at line 377 of file res_stun_monitor.c.

References a, args, ast_cli(), ast_inet_ntoa(), DATALN, DEFAULT_RETRIES, handle_cli_stun_show_status(), HEADER, and status.

Referenced by handle_cli_stun_show_status(), and load_config().

{
   const char *status;

#define DATALN "%-25s %-5u %-7u %-8d %-7s %-16s %-d\n"
#define HEADER "%-25s %-5s %-7s %-8s %-7s %-16s %-s\n"

   /*! we only have one stun server, but start to play well with more */
   ast_cli(fd, HEADER, "Hostname", "Port", "Period", "Retries", "Status", "ExternAddr", "ExternPort");

   if (args.stun_poll_failed_gripe) {
      status = "FAIL";
   } else if (args.external_addr_known) {
      status = "OK";
   } else {
      status = "INIT";
   }
   ast_cli( fd, DATALN,
           args.server_hostname,
           args.stun_port,
           args.refresh,
           DEFAULT_RETRIES,
           status,
           ast_inet_ntoa(args.external_addr.sin_addr),
           ntohs(args.external_addr.sin_port)
         );

#undef HEADER
#undef DATALN
}

AST_MODULE_SELF_SYM()

struct ast_module* AST_MODULE_SELF_SYM

(

void

)

Definition at line 487 of file res_stun_monitor.c.

handle_cli_stun_show_status()

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

static

Definition at line 408 of file res_stun_monitor.c.

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

Referenced by _stun_show_status().

{
   switch (cmd) {
   case CLI_INIT:
      e->command = "stun show status";
      e->usage =
          "Usage: stun show status\n"
          "       List all known STUN servers and statuses.\n";
      return NULL;
   case CLI_GENERATE:
      return NULL;
   }

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

   _stun_show_status(a->fd);
   return CLI_SUCCESS;
}

load_config()

static int load_config ( int  startup )

static

Definition at line 327 of file res_stun_monitor.c.

References _stun_show_status(), 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(), stun_conf_file, and ast_variable::value.

Referenced by __reload(), and setup_stunaddr().

{
   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, !startup)) {
            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;
}

load_module()

static int load_module ( void  )

static

Register CLI commands

Definition at line 466 of file res_stun_monitor.c.

References __reload(), args, ast_cli_register_multiple, AST_MODFLAG_GLOBAL_SYMBOLS, AST_MODFLAG_LOAD_ORDER, AST_MODPRI_CHANNEL_DEPEND, AST_MODULE_INFO(), AST_MODULE_LOAD_DECLINE, AST_MODULE_LOAD_SUCCESS, AST_MODULE_SUPPORT_CORE, ast_mutex_destroy, ast_mutex_init, ASTERISK_GPL_KEY, reload(), and unload_module().

Referenced by unload_module().

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

   /*! Register CLI commands */
   ast_cli_register_multiple(cli_stun, sizeof(cli_stun) / sizeof(struct ast_cli_entry));

   return AST_MODULE_LOAD_SUCCESS;
}

reload()

static int reload ( void  )

static

Definition at line 450 of file res_stun_monitor.c.

References __reload(), and unload_module().

Referenced by __reload(), load_module(), and stun_start_monitor().

{
   return __reload(0);
}

setup_stunaddr()

static int setup_stunaddr ( const char *  value, int  reload  )

static

Definition at line 273 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, load_config(), LOG_WARNING, ast_sockaddr::ss, STANDARD_STUN_PORT, and value.

Referenced by load_config(), and stun_start_monitor().

{
   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);

      /* Only treat this as fatal if we are reloading */
      if (reload) {
         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;
}

stun_close_sock()

static void stun_close_sock ( void  )

static

Definition at line 76 of file res_stun_monitor.c.

References args, and stun_monitor_request().

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;
   }
}

stun_monitor_request()

static int stun_monitor_request ( const void *  blarg )

static

Definition at line 85 of file res_stun_monitor.c.

References answer(), ao2_cleanup, args, ast_connect(), ast_get_ip(), ast_inet_ntoa(), ast_json_object_create(), ast_json_payload_create(), ast_json_unref(), ast_log, ast_mutex_lock, ast_mutex_unlock, ast_network_change_type(), ast_sockaddr_set_port, ast_sockaddr_stringify(), ast_strdupa, ast_stun_request(), ast_system_topic(), errno, LOG_ERROR, LOG_NOTICE, LOG_WARNING, NULL, RAII_VAR, ast_sockaddr::ss, stasis_message_create(), stasis_publish(), stun_close_sock(), and stun_stop_monitor().

Referenced by stun_close_sock(), and 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) {
            RAII_VAR(struct stasis_message *, msg, NULL, ao2_cleanup);
            RAII_VAR(struct ast_json_payload *, json_payload, NULL, ao2_cleanup);
            RAII_VAR(struct ast_json *, json_object, NULL, ast_json_unref);

            if (!ast_network_change_type()) {
               goto publish_failure;
            }

            /* This json_object doesn't actually contain anything yet. We have to reference something
             * for stasis, and this is useful for if we want to ever add data for any reason. */
            json_object = ast_json_object_create();
            if (!json_object) {
               goto publish_failure;
            }

            if (!(json_payload = ast_json_payload_create(json_object))) {
               goto publish_failure;
            }

            msg = stasis_message_create(ast_network_change_type(), json_payload);

publish_failure:
            if (msg) {
               stasis_publish(ast_system_topic(), msg);
            } else {
               ast_log(LOG_ERROR, "Failed to issue network change message.\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;
}

stun_start_monitor()

static int stun_start_monitor ( void  )

static

Definition at line 233 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, NULL, reload(), setup_stunaddr(), stun_close_sock(), stun_monitor_request(), and value.

Referenced by __reload(), and stun_stop_monitor().

{
   /* 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;
}

stun_stop_monitor()

static void stun_stop_monitor ( void  )

static

Definition at line 209 of file res_stun_monitor.c.

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

Referenced by __reload(), stun_monitor_request(), 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");
   }
}

unload_module()

static int unload_module ( void  )

static

Unregister CLI commands

Definition at line 455 of file res_stun_monitor.c.

References args, ARRAY_LEN, ast_cli_unregister_multiple(), ast_mutex_destroy, load_module(), and stun_stop_monitor().

Referenced by load_module(), and reload().

{
   stun_stop_monitor();
   ast_mutex_destroy(&args.lock);

   /*! Unregister CLI commands */
   ast_cli_unregister_multiple(cli_stun, ARRAY_LEN(cli_stun));

   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 = "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, .support_level = AST_MODULE_SUPPORT_CORE, .load = load_module, .unload = unload_module, .reload = reload, .load_pri = AST_MODPRI_CHANNEL_DEPEND }

static

Definition at line 487 of file res_stun_monitor.c.

args

struct { ... } args

Referenced by __reload(), _stun_show_status(), load_config(), load_module(), setup_stunaddr(), stun_close_sock(), stun_monitor_request(), stun_start_monitor(), stun_stop_monitor(), and unload_module().

ast_module_info

const struct ast_module_info* ast_module_info = &__mod_info

static

Definition at line 487 of file res_stun_monitor.c.

cli_stun

struct ast_cli_entry cli_stun[]

static

Initial value:

= {
   { .handler =  handle_cli_stun_show_status , .summary =  "Show STUN servers and statuses" ,},
}

Definition at line 429 of file res_stun_monitor.c.

external_addr

struct sockaddr_in external_addr

Current perceived external address.

Definition at line 59 of file res_stun_monitor.c.

external_addr_known

unsigned int external_addr_known

TRUE if the perceived external address is valid/known.

Definition at line 71 of file res_stun_monitor.c.

lock

ast_mutex_t lock

STUN monitor protection lock.

Definition at line 57 of file res_stun_monitor.c.

monitor_enabled

unsigned int monitor_enabled

TRUE if the STUN monitor is enabled.

Definition at line 69 of file res_stun_monitor.c.

refresh

unsigned int refresh

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

Definition at line 65 of file res_stun_monitor.c.

Referenced by iax2_ack_registry(), and update_registry().

sched

struct ast_sched_context* sched

static

Definition at line 53 of file res_stun_monitor.c.

server_hostname

const char* server_hostname

STUN server host name.

Definition at line 61 of file res_stun_monitor.c.

stun_conf_file

const char stun_conf_file[] = "res_stun_monitor.conf"

static

Definition at line 52 of file res_stun_monitor.c.

Referenced by load_config().

stun_poll_failed_gripe

unsigned int stun_poll_failed_gripe

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

Definition at line 73 of file res_stun_monitor.c.

stun_port

unsigned int stun_port

Port of STUN server to use

Definition at line 63 of file res_stun_monitor.c.

stun_sock

int stun_sock

Monitoring STUN socket.

Definition at line 67 of file res_stun_monitor.c.