Previously, I had added the ast_sched_thread stuff that was a generic scheduler thread implementation. However, if you used it, it required using different functions for modifying scheduler contents. This patch reworks how this is done and just allows you to optionally start a thread on the original scheduler context structure that has always been there. This makes it trivial to switch to the generic scheduler thread implementation without having to touch any of the other code that adds or removes scheduler entries. In passing, I made some naming tweaks to add ast_ prefixes where they were not there before. Review: https://reviewboard.asterisk.org/r/1007/ git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@299091 65c4cc65-6c06-0410-ace0-fbb531ad65f3
321 lines
8.6 KiB
C
321 lines
8.6 KiB
C
/*
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* Asterisk -- An open source telephony toolkit.
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*
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* Copyright (C) 2010, Digium, Inc.
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*
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* David Vossel <dvossel@digium.com>
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*
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* See http://www.asterisk.org for more information about
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* the Asterisk project. Please do not directly contact
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* any of the maintainers of this project for assistance;
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* the project provides a web site, mailing lists and IRC
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* channels for your use.
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*
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* This program is free software, distributed under the terms of
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* the GNU General Public License Version 2. See the LICENSE file
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* at the top of the source tree.
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*/
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/*!
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* \file
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* \brief STUN Network Monitor
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*
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* \author David Vossel <dvossel@digium.com>
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*/
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#include "asterisk.h"
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ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
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#include "asterisk/module.h"
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#include "asterisk/event.h"
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#include "asterisk/sched.h"
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#include "asterisk/config.h"
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#include "asterisk/stun.h"
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#include "asterisk/netsock2.h"
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#include "asterisk/lock.h"
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#include <fcntl.h>
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static const int DEFAULT_MONITOR_REFRESH = 30;
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static const char stun_conf_file[] = "res_stun_monitor.conf";
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static struct ast_sched_context *sched;
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static struct {
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struct sockaddr_in stunaddr; /*!< The stun address we send requests to*/
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struct sockaddr_in externaladdr; /*!< current perceived external address. */
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ast_mutex_t lock;
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unsigned int refresh;
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int stunsock;
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unsigned int monitor_enabled:1;
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unsigned int externaladdr_known:1;
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} args;
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static inline void stun_close_sock(void)
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{
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if (args.stunsock != -1) {
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close(args.stunsock);
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args.stunsock = -1;
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memset(&args.externaladdr, 0, sizeof(args.externaladdr));
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args.externaladdr_known = 0;
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}
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}
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/* \brief purge the stun socket's receive buffer before issuing a new request
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*
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* XXX Note that this is somewhat of a hack. This function is essentially doing
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* a cleanup on the socket rec buffer to handle removing any STUN responses we have not
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* handled. This is called before sending out a new STUN request so we don't read
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* a latent previous response thinking it is new.
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*/
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static void stun_purge_socket(void)
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{
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int flags = fcntl(args.stunsock, F_GETFL);
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int res = 0;
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unsigned char reply_buf[1024];
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fcntl(args.stunsock, F_SETFL, flags | O_NONBLOCK);
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while (res != -1) {
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/* throw away everything in the buffer until we reach the end. */
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res = recv(args.stunsock, reply_buf, sizeof(reply_buf), 0);
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}
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fcntl(args.stunsock, F_SETFL, flags & ~O_NONBLOCK);
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}
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/* \brief called by scheduler to send STUN request */
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static int stun_monitor_request(const void *blarg)
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{
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int res;
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int generate_event = 0;
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struct sockaddr_in answer = { 0, };
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/* once the stun socket goes away, this scheduler item will go away as well */
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ast_mutex_lock(&args.lock);
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if (args.stunsock == -1) {
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ast_log(LOG_ERROR, "STUN monitor: can not send STUN request, socket is not open\n");
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goto monitor_request_cleanup;
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}
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stun_purge_socket();
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if (!(ast_stun_request(args.stunsock, &args.stunaddr, NULL, &answer)) &&
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(memcmp(&args.externaladdr, &answer, sizeof(args.externaladdr)))) {
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const char *newaddr = ast_strdupa(ast_inet_ntoa(answer.sin_addr));
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int newport = ntohs(answer.sin_port);
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ast_log(LOG_NOTICE, "STUN MONITOR: Old external address/port %s:%d now seen as %s:%d \n",
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ast_inet_ntoa(args.externaladdr.sin_addr), ntohs(args.externaladdr.sin_port),
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newaddr, newport);
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memcpy(&args.externaladdr, &answer, sizeof(args.externaladdr));
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if (args.externaladdr_known) {
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/* the external address was already known, and has changed... generate event. */
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generate_event = 1;
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} else {
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/* this was the first external address we found, do not alert listeners
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* until this address changes to something else. */
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args.externaladdr_known = 1;
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}
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}
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if (generate_event) {
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struct ast_event *event = ast_event_new(AST_EVENT_NETWORK_CHANGE, AST_EVENT_IE_END);
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if (!event) {
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ast_log(LOG_ERROR, "STUN monitor: could not create AST_EVENT_NETWORK_CHANGE event.\n");
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goto monitor_request_cleanup;
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}
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if (ast_event_queue(event)) {
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ast_event_destroy(event);
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event = NULL;
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ast_log(LOG_ERROR, "STUN monitor: could not queue AST_EVENT_NETWORK_CHANGE event.\n");
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goto monitor_request_cleanup;
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}
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}
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monitor_request_cleanup:
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/* always refresh this scheduler item. It will be removed elsewhere when
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* it is supposed to go away */
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res = args.refresh * 1000;
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ast_mutex_unlock(&args.lock);
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return res;
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}
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/* \brief stops the stun monitor thread
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* \note do not hold the args->lock while calling this
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*/
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static void stun_stop_monitor(void)
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{
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if (sched) {
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ast_sched_context_destroy(sched);
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sched = NULL;
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ast_log(LOG_NOTICE, "STUN monitor stopped\n");
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}
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/* it is only safe to destroy the socket without holding arg->lock
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* after the sched thread is destroyed */
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stun_close_sock();
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}
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/* \brief starts the stun monitor thread
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* \note The args->lock MUST be held when calling this function
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*/
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static int stun_start_monitor(void)
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{
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struct ast_sockaddr dst;
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/* clean up any previous open socket */
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stun_close_sock();
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/* create destination ast_sockaddr */
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ast_sockaddr_from_sin(&dst, &args.stunaddr);
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/* open new socket binding */
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args.stunsock = socket(AF_INET, SOCK_DGRAM, 0);
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if (args.stunsock < 0) {
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ast_log(LOG_WARNING, "Unable to create STUN socket: %s\n", strerror(errno));
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return -1;
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}
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if (ast_connect(args.stunsock, &dst) != 0) {
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ast_log(LOG_WARNING, "SIP STUN Failed to connect to %s\n", ast_sockaddr_stringify(&dst));
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stun_close_sock();
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return -1;
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}
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/* if scheduler thread is not started, make sure to start it now */
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if (sched) {
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return 0; /* already started */
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}
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if (!(sched = ast_sched_context_create())) {
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ast_log(LOG_ERROR, "Failed to create stun monitor scheduler context\n");
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stun_close_sock();
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return -1;
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}
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if (ast_sched_start_thread(sched)) {
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ast_sched_context_destroy(sched);
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sched = NULL;
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stun_close_sock();
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return -1;
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}
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if (ast_sched_add_variable(sched, (args.refresh * 1000), stun_monitor_request, NULL, 1) < 0) {
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ast_log(LOG_ERROR, "Unable to schedule STUN network monitor \n");
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ast_sched_context_destroy(sched);
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sched = NULL;
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stun_close_sock();
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return -1;
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}
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ast_log(LOG_NOTICE, "STUN monitor started\n");
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return 0;
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}
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static int load_config(int startup)
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{
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struct ast_flags config_flags = { 0, };
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struct ast_config *cfg;
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struct ast_variable *v;
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if (!startup) {
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ast_set_flag(&config_flags, CONFIG_FLAG_FILEUNCHANGED);
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}
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if (!(cfg = ast_config_load2(stun_conf_file, "res_stun_monitor", config_flags)) ||
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cfg == CONFIG_STATUS_FILEINVALID) {
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ast_log(LOG_WARNING, "Unable to load config %s\n", stun_conf_file);
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return -1;
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}
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if (cfg == CONFIG_STATUS_FILEUNCHANGED && !startup) {
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return 0;
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}
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/* set defaults */
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args.monitor_enabled = 0;
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memset(&args.stunaddr, 0, sizeof(args.stunaddr));
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args.refresh = DEFAULT_MONITOR_REFRESH;
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for (v = ast_variable_browse(cfg, "general"); v; v = v->next) {
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if (!strcasecmp(v->name, "stunaddr")) {
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args.stunaddr.sin_port = htons(STANDARD_STUN_PORT);
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if (ast_parse_arg(v->value, PARSE_INADDR, &args.stunaddr)) {
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ast_log(LOG_WARNING, "Invalid STUN server address: %s\n", v->value);
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} else {
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ast_log(LOG_NOTICE, "STUN monitor enabled: %s\n", v->value);
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args.monitor_enabled = 1;
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}
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} else if (!strcasecmp(v->name, "stunrefresh")) {
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if ((sscanf(v->value, "%30u", &args.refresh) != 1) || !args.refresh) {
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ast_log(LOG_WARNING, "Invalid stunrefresh value '%s', must be an integer > 0 at line %d\n", v->value, v->lineno);
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args.refresh = DEFAULT_MONITOR_REFRESH;
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} else {
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ast_log(LOG_NOTICE, "STUN Monitor set to refresh every %d seconds\n", args.refresh);
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}
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} else {
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ast_log(LOG_WARNING, "SIP STUN: invalid config option %s at line %d\n", v->value, v->lineno);
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}
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}
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ast_config_destroy(cfg);
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return 0;
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}
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static int __reload(int startup)
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{
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int res;
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ast_mutex_lock(&args.lock);
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if (!(res = load_config(startup)) && args.monitor_enabled) {
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res = stun_start_monitor();
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}
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ast_mutex_unlock(&args.lock);
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if ((res == -1) || !args.monitor_enabled) {
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args.monitor_enabled = 0;
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stun_stop_monitor();
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}
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return res;
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}
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static int reload(void)
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{
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return __reload(0);
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}
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static int unload_module(void)
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{
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stun_stop_monitor();
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ast_mutex_destroy(&args.lock);
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return 0;
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}
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static int load_module(void)
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{
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ast_mutex_init(&args.lock);
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args.stunsock = -1;
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memset(&args.externaladdr, 0, sizeof(args.externaladdr));
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args.externaladdr_known = 0;
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sched = NULL;
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if (__reload(1)) {
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stun_stop_monitor();
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ast_mutex_destroy(&args.lock);
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return AST_MODULE_LOAD_DECLINE;
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}
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return AST_MODULE_LOAD_SUCCESS;
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}
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AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_GLOBAL_SYMBOLS | AST_MODFLAG_LOAD_ORDER, "STUN Network Monitor",
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.load = load_module,
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.unload = unload_module,
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.reload = reload,
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.load_pri = AST_MODPRI_CHANNEL_DEPEND
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);
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