Update of /usr/cvsroot/asterisk
In directory mongoose.digium.com:/tmp/cvs-serv17258
Added Files:
dnsmgr.c
Log Message:
preliminary "managed DNS lookup" support
--- NEW FILE: dnsmgr.c ---
/*
* Asterisk -- A telephony toolkit for Linux.
*
* Background DNS update manager
*
* Copyright (C) 2005, Kevin P. Fleming
*
* Kevin P. Fleming <[EMAIL PROTECTED]>
*
* This program is free software, distributed under the terms of
* the GNU General Public License
*/
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <resolv.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <regex.h>
#include <signal.h>
#include <asterisk/dnsmgr.h>
#include <asterisk/linkedlists.h>
#include <asterisk/utils.h>
#include <asterisk/config.h>
#include <asterisk/logger.h>
#include <asterisk/sched.h>
#include <asterisk/options.h>
#include <asterisk/cli.h>
#include "asterisk.h"
static struct sched_context *sched;
static int refresh_sched = -1;
static pthread_t refresh_thread = AST_PTHREADT_NULL;
struct ast_dnsmgr_entry {
struct in_addr *result;
AST_LIST_ENTRY(ast_dnsmgr_entry) list;
char name[1];
};
static AST_LIST_HEAD(entry_list, ast_dnsmgr_entry) entry_list;
AST_MUTEX_DEFINE_STATIC(refresh_lock);
#define REFRESH_DEFAULT 300
static int enabled = 0;
static int refresh_interval;
struct refresh_info {
struct entry_list *entries;
int verbose;
regex_t filter;
};
static struct refresh_info master_refresh_info = {
.entries = &entry_list,
.verbose = 0,
};
struct ast_dnsmgr_entry *ast_dnsmgr_get(const char *name, struct in_addr
*result)
{
struct ast_dnsmgr_entry *entry;
if (!name || !result || ast_strlen_zero(name))
return NULL;
entry = calloc(1, sizeof(*result) + strlen(name));
if (!entry)
return NULL;
entry->result = result;
strcpy(entry->name, name);
AST_LIST_LOCK(&entry_list);
AST_LIST_INSERT_HEAD(&entry_list, entry, list);
AST_LIST_UNLOCK(&entry_list);
return entry;
}
void ast_dnsmgr_release(struct ast_dnsmgr_entry *entry)
{
/* if there is an entry (and not the special flag value), remove/free
it */
if (entry && (entry != (typeof(entry)) -1)) {
AST_LIST_LOCK(&entry_list);
AST_LIST_REMOVE(&entry_list, entry, list);
AST_LIST_UNLOCK(&entry_list);
free(entry);
};
}
int ast_dnsmgr_lookup(const char *name, struct in_addr *result, struct
ast_dnsmgr_entry **dnsmgr)
{
if (!name || ast_strlen_zero(name) || !result || !dnsmgr)
return -1;
if (*dnsmgr && !strcasecmp((*dnsmgr)->name, name))
return 0;
if (option_verbose > 3)
ast_verbose(VERBOSE_PREFIX_3 "doing lookup for '%s'\n", name);
/* if it's actually an IP address and not a name,
there's no need for a managed lookup */
if (inet_aton(name, result))
return 0;
/* if the manager is disabled, do a direct lookup and return the result,
otherwise register a managed lookup for the name */
if (!enabled) {
struct ast_hostent ahp;
struct hostent *hp;
if ((hp = ast_gethostbyname(name, &ahp)))
memcpy(result, hp->h_addr, sizeof(result));
/* flag value to indicate no manager was allocated */
*dnsmgr = (typeof(*dnsmgr)) -1;
} else {
if (option_verbose > 2)
ast_verbose(VERBOSE_PREFIX_2 "adding manager for
'%s'\n", name);
*dnsmgr = ast_dnsmgr_get(name, result);
}
return !*dnsmgr;
}
static void *do_refresh(void *data)
{
for (;;) {
pthread_testcancel();
usleep(ast_sched_wait(sched));
pthread_testcancel();
ast_sched_runq(sched);
}
return NULL;
}
static int refresh_list(void *data)
{
struct refresh_info *info = data;
struct ast_dnsmgr_entry *entry;
struct ast_hostent ahp;
struct hostent *hp;
/* 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;
}
if (option_verbose > 2)
ast_verbose(VERBOSE_PREFIX_2 "Refreshing DNS lookups.\n");
AST_LIST_LOCK(info->entries);
AST_LIST_TRAVERSE(info->entries, entry, list) {
if (info->filter.used && regexec(&info->filter, entry->name, 0,
NULL, 0))
continue;
if (info->verbose && (option_verbose > 2))
ast_verbose(VERBOSE_PREFIX_2 "refreshing '%s'\n",
entry->name);
if ((hp = ast_gethostbyname(entry->name, &ahp))) {
/* check to see if it has changed, do callback if
requested */
memcpy(entry->result, hp->h_addr,
sizeof(entry->result));
}
}
AST_LIST_UNLOCK(info->entries);
ast_mutex_unlock(&refresh_lock);
/* automatically reschedule */
return -1;
}
static int do_reload(int loading);
static int handle_cli_reload(int fd, int argc, char *argv[])
{
if (argc > 2)
return RESULT_SHOWUSAGE;
do_reload(0);
return 0;
}
static int handle_cli_refresh(int fd, int argc, char *argv[])
{
struct refresh_info info = {
.entries = &entry_list,
.verbose = 1,
};
if (argc > 3)
return RESULT_SHOWUSAGE;
if (argc == 3) {
if (regcomp(&info.filter, argv[2], REG_EXTENDED | REG_NOSUB))
return RESULT_SHOWUSAGE;
}
refresh_list(&info);
if (info.filter.used)
regfree(&info.filter);
return 0;
}
static int handle_cli_status(int fd, int argc, char *argv[])
{
int count = 0;
struct ast_dnsmgr_entry *entry;
if (argc > 2)
return RESULT_SHOWUSAGE;
ast_cli(fd, "DNS Manager: %s\n", enabled ? "enabled" : "disabled");
ast_cli(fd, "Refresh Interval: %d seconds\n", refresh_interval);
AST_LIST_LOCK(&entry_list);
AST_LIST_TRAVERSE(&entry_list, entry, list)
count++;
AST_LIST_UNLOCK(&entry_list);
ast_cli(fd, "Number of entries: %d\n", count);
return 0;
}
static struct ast_cli_entry cli_reload = {
.cmda = { "dnsmgr", "reload", NULL },
.handler = handle_cli_reload,
.summary = "Reloads the DNS manager configuration",
.usage =
"Usage: dnsmgr reload\n"
" Reloads the DNS manager configuration.\n"
};
static struct ast_cli_entry cli_refresh = {
.cmda = { "dnsmgr", "refresh", NULL },
.handler = handle_cli_refresh,
.summary = "Performs an immediate refresh",
.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",
};
static struct ast_cli_entry cli_status = {
.cmda = { "dnsmgr", "status", NULL },
.handler = handle_cli_status,
.summary = "Display the DNS manager status",
.usage =
"Usage: dnsmgr status\n"
" Displays the DNS manager status.\n"
};
int dnsmgr_init(void)
{
sched = sched_context_create();
if (!sched) {
ast_log(LOG_ERROR, "Unable to create schedule context.\n");
return -1;
}
AST_LIST_HEAD_INIT(&entry_list);
ast_cli_register(&cli_reload);
ast_cli_register(&cli_status);
return do_reload(1);
}
void dnsmgr_reload(void)
{
do_reload(0);
}
static int do_reload(int loading)
{
struct ast_config *config;
const char *interval_value;
const char *enabled_value;
int interval;
int was_enabled;
pthread_attr_t attr;
int res = -1;
/* 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 (refresh_sched > -1)
ast_sched_del(sched, refresh_sched);
if ((config = ast_config_load("dnsmgr.conf"))) {
if ((enabled_value = ast_variable_retrieve(config, "general",
"enabled"))) {
enabled = ast_true(enabled_value);
}
if ((interval_value = ast_variable_retrieve(config, "general",
"refreshinterval"))) {
if (sscanf(interval_value, "%d", &interval) < 1)
ast_log(LOG_WARNING, "Unable to convert '%s' to
a numeric value.\n", interval_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) {
refresh_sched = ast_sched_add(sched, refresh_interval * 1000,
refresh_list, &master_refresh_info);
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 && !was_enabled && (refresh_thread == AST_PTHREADT_NULL)) {
pthread_attr_init(&attr);
pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
if (ast_pthread_create(&refresh_thread, &attr, do_refresh,
NULL) < 0) {
ast_log(LOG_ERROR, "Unable to start refresh thread.\n");
ast_sched_del(sched, refresh_sched);
}
else {
ast_cli_register(&cli_refresh);
res = 0;
}
}
/* 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_cli_unregister(&cli_refresh);
res = 0;
}
else
res = 0;
ast_mutex_unlock(&refresh_lock);
return res;
}
_______________________________________________
Asterisk-Cvs mailing list
[email protected]
http://lists.digium.com/mailman/listinfo/asterisk-cvs
