Files
asterisk/main/db.c
Tilghman Lesher d09fddd38e Fix race in astdb
The underlying db1 implementation does not fully isolate the pages retrieved
from astdb, so the lock protecting accesses needs to be extended until the
copy from the shared memory structure is done.
(closes issue #14682)
 Reported by: makoto


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@182449 65c4cc65-6c06-0410-ace0-fbb531ad65f3
2009-03-17 05:50:52 +00:00

596 lines
14 KiB
C

/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (C) 1999 - 2005, Digium, Inc.
*
* Mark Spencer <markster@digium.com>
*
* See http://www.asterisk.org for more information about
* the Asterisk project. Please do not directly contact
* any of the maintainers of this project for assistance;
* the project provides a web site, mailing lists and IRC
* channels for your use.
*
* This program is free software, distributed under the terms of
* the GNU General Public License Version 2. See the LICENSE file
* at the top of the source tree.
*/
/*! \file
*
* \brief ASTdb Management
*
* \author Mark Spencer <markster@digium.com>
*
* \note DB3 is licensed under Sleepycat Public License and is thus incompatible
* with GPL. To avoid having to make another exception (and complicate
* licensing even further) we elect to use DB1 which is BSD licensed
*/
#include "asterisk.h"
ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include <signal.h>
#include <errno.h>
#include <unistd.h>
#include <dirent.h>
#include "asterisk/channel.h"
#include "asterisk/file.h"
#include "asterisk/app.h"
#include "asterisk/dsp.h"
#include "asterisk/logger.h"
#include "asterisk/options.h"
#include "asterisk/astdb.h"
#include "asterisk/cli.h"
#include "asterisk/utils.h"
#include "asterisk/lock.h"
#include "asterisk/manager.h"
#include "db1-ast/include/db.h"
#ifdef __CYGWIN__
#define dbopen __dbopen
#endif
static DB *astdb;
AST_MUTEX_DEFINE_STATIC(dblock);
static int dbinit(void)
{
if (!astdb && !(astdb = dbopen((char *)ast_config_AST_DB, O_CREAT | O_RDWR, 0664, DB_BTREE, NULL))) {
ast_log(LOG_WARNING, "Unable to open Asterisk database '%s': %s\n", ast_config_AST_DB, strerror(errno));
return -1;
}
return 0;
}
static inline int keymatch(const char *key, const char *prefix)
{
int preflen = strlen(prefix);
if (!preflen)
return 1;
if (!strcasecmp(key, prefix))
return 1;
if ((strlen(key) > preflen) && !strncasecmp(key, prefix, preflen)) {
if (key[preflen] == '/')
return 1;
}
return 0;
}
static inline int subkeymatch(const char *key, const char *suffix)
{
int suffixlen = strlen(suffix);
if (suffixlen) {
const char *subkey = key + strlen(key) - suffixlen;
if (subkey < key)
return 0;
if (!strcasecmp(subkey, suffix))
return 1;
}
return 0;
}
int ast_db_deltree(const char *family, const char *keytree)
{
char prefix[256];
DBT key, data;
char *keys;
int res;
int pass;
if (family) {
if (keytree) {
snprintf(prefix, sizeof(prefix), "/%s/%s", family, keytree);
} else {
snprintf(prefix, sizeof(prefix), "/%s", family);
}
} else if (keytree) {
return -1;
} else {
prefix[0] = '\0';
}
ast_mutex_lock(&dblock);
if (dbinit()) {
ast_mutex_unlock(&dblock);
return -1;
}
memset(&key, 0, sizeof(key));
memset(&data, 0, sizeof(data));
pass = 0;
while (!(res = astdb->seq(astdb, &key, &data, pass++ ? R_NEXT : R_FIRST))) {
if (key.size) {
keys = key.data;
keys[key.size - 1] = '\0';
} else {
keys = "<bad key>";
}
if (keymatch(keys, prefix)) {
astdb->del(astdb, &key, 0);
}
}
astdb->sync(astdb, 0);
ast_mutex_unlock(&dblock);
return 0;
}
int ast_db_put(const char *family, const char *keys, char *value)
{
char fullkey[256];
DBT key, data;
int res, fullkeylen;
ast_mutex_lock(&dblock);
if (dbinit()) {
ast_mutex_unlock(&dblock);
return -1;
}
fullkeylen = snprintf(fullkey, sizeof(fullkey), "/%s/%s", family, keys);
memset(&key, 0, sizeof(key));
memset(&data, 0, sizeof(data));
key.data = fullkey;
key.size = fullkeylen + 1;
data.data = value;
data.size = strlen(value) + 1;
res = astdb->put(astdb, &key, &data, 0);
astdb->sync(astdb, 0);
ast_mutex_unlock(&dblock);
if (res)
ast_log(LOG_WARNING, "Unable to put value '%s' for key '%s' in family '%s'\n", value, keys, family);
return res;
}
int ast_db_get(const char *family, const char *keys, char *value, int valuelen)
{
char fullkey[256] = "";
DBT key, data;
int res, fullkeylen;
ast_mutex_lock(&dblock);
if (dbinit()) {
ast_mutex_unlock(&dblock);
return -1;
}
fullkeylen = snprintf(fullkey, sizeof(fullkey), "/%s/%s", family, keys);
memset(&key, 0, sizeof(key));
memset(&data, 0, sizeof(data));
memset(value, 0, valuelen);
key.data = fullkey;
key.size = fullkeylen + 1;
res = astdb->get(astdb, &key, &data, 0);
/* Be sure to NULL terminate our data either way */
if (res) {
if (option_debug)
ast_log(LOG_DEBUG, "Unable to find key '%s' in family '%s'\n", keys, family);
} else {
#if 0
printf("Got value of size %d\n", data.size);
#endif
if (data.size) {
((char *)data.data)[data.size - 1] = '\0';
/* Make sure that we don't write too much to the dst pointer or we don't read too much from the source pointer */
ast_copy_string(value, data.data, (valuelen > data.size) ? data.size : valuelen);
} else {
ast_log(LOG_NOTICE, "Strange, empty value for /%s/%s\n", family, keys);
}
}
/* Data is not fully isolated for concurrency, so the lock must be extended
* to after the copy to the output buffer. */
ast_mutex_unlock(&dblock);
return res;
}
int ast_db_del(const char *family, const char *keys)
{
char fullkey[256];
DBT key;
int res, fullkeylen;
ast_mutex_lock(&dblock);
if (dbinit()) {
ast_mutex_unlock(&dblock);
return -1;
}
fullkeylen = snprintf(fullkey, sizeof(fullkey), "/%s/%s", family, keys);
memset(&key, 0, sizeof(key));
key.data = fullkey;
key.size = fullkeylen + 1;
res = astdb->del(astdb, &key, 0);
astdb->sync(astdb, 0);
ast_mutex_unlock(&dblock);
if (res && option_debug)
ast_log(LOG_DEBUG, "Unable to find key '%s' in family '%s'\n", keys, family);
return res;
}
static int database_put(int fd, int argc, char *argv[])
{
int res;
if (argc != 5)
return RESULT_SHOWUSAGE;
res = ast_db_put(argv[2], argv[3], argv[4]);
if (res) {
ast_cli(fd, "Failed to update entry\n");
} else {
ast_cli(fd, "Updated database successfully\n");
}
return RESULT_SUCCESS;
}
static int database_get(int fd, int argc, char *argv[])
{
int res;
char tmp[256];
if (argc != 4)
return RESULT_SHOWUSAGE;
res = ast_db_get(argv[2], argv[3], tmp, sizeof(tmp));
if (res) {
ast_cli(fd, "Database entry not found.\n");
} else {
ast_cli(fd, "Value: %s\n", tmp);
}
return RESULT_SUCCESS;
}
static int database_del(int fd, int argc, char *argv[])
{
int res;
if (argc != 4)
return RESULT_SHOWUSAGE;
res = ast_db_del(argv[2], argv[3]);
if (res) {
ast_cli(fd, "Database entry does not exist.\n");
} else {
ast_cli(fd, "Database entry removed.\n");
}
return RESULT_SUCCESS;
}
static int database_deltree(int fd, int argc, char *argv[])
{
int res;
if ((argc < 3) || (argc > 4))
return RESULT_SHOWUSAGE;
if (argc == 4) {
res = ast_db_deltree(argv[2], argv[3]);
} else {
res = ast_db_deltree(argv[2], NULL);
}
if (res) {
ast_cli(fd, "Database entries do not exist.\n");
} else {
ast_cli(fd, "Database entries removed.\n");
}
return RESULT_SUCCESS;
}
static int database_show(int fd, int argc, char *argv[])
{
char prefix[256];
DBT key, data;
char *keys, *values;
int res;
int pass;
if (argc == 4) {
/* Family and key tree */
snprintf(prefix, sizeof(prefix), "/%s/%s", argv[2], argv[3]);
} else if (argc == 3) {
/* Family only */
snprintf(prefix, sizeof(prefix), "/%s", argv[2]);
} else if (argc == 2) {
/* Neither */
prefix[0] = '\0';
} else {
return RESULT_SHOWUSAGE;
}
ast_mutex_lock(&dblock);
if (dbinit()) {
ast_mutex_unlock(&dblock);
ast_cli(fd, "Database unavailable\n");
return RESULT_SUCCESS;
}
memset(&key, 0, sizeof(key));
memset(&data, 0, sizeof(data));
pass = 0;
while (!(res = astdb->seq(astdb, &key, &data, pass++ ? R_NEXT : R_FIRST))) {
if (key.size) {
keys = key.data;
keys[key.size - 1] = '\0';
} else {
keys = "<bad key>";
}
if (data.size) {
values = data.data;
values[data.size - 1]='\0';
} else {
values = "<bad value>";
}
if (keymatch(keys, prefix)) {
ast_cli(fd, "%-50s: %-25s\n", keys, values);
}
}
ast_mutex_unlock(&dblock);
return RESULT_SUCCESS;
}
static int database_showkey(int fd, int argc, char *argv[])
{
char suffix[256];
DBT key, data;
char *keys, *values;
int res;
int pass;
if (argc == 3) {
/* Key only */
snprintf(suffix, sizeof(suffix), "/%s", argv[2]);
} else {
return RESULT_SHOWUSAGE;
}
ast_mutex_lock(&dblock);
if (dbinit()) {
ast_mutex_unlock(&dblock);
ast_cli(fd, "Database unavailable\n");
return RESULT_SUCCESS;
}
memset(&key, 0, sizeof(key));
memset(&data, 0, sizeof(data));
pass = 0;
while (!(res = astdb->seq(astdb, &key, &data, pass++ ? R_NEXT : R_FIRST))) {
if (key.size) {
keys = key.data;
keys[key.size - 1] = '\0';
} else {
keys = "<bad key>";
}
if (data.size) {
values = data.data;
values[data.size - 1]='\0';
} else {
values = "<bad value>";
}
if (subkeymatch(keys, suffix)) {
ast_cli(fd, "%-50s: %-25s\n", keys, values);
}
}
ast_mutex_unlock(&dblock);
return RESULT_SUCCESS;
}
struct ast_db_entry *ast_db_gettree(const char *family, const char *keytree)
{
char prefix[256];
DBT key, data;
char *keys, *values;
int values_len;
int res;
int pass;
struct ast_db_entry *last = NULL;
struct ast_db_entry *cur, *ret=NULL;
if (!ast_strlen_zero(family)) {
if (!ast_strlen_zero(keytree)) {
/* Family and key tree */
snprintf(prefix, sizeof(prefix), "/%s/%s", family, keytree);
} else {
/* Family only */
snprintf(prefix, sizeof(prefix), "/%s", family);
}
} else {
prefix[0] = '\0';
}
ast_mutex_lock(&dblock);
if (dbinit()) {
ast_mutex_unlock(&dblock);
ast_log(LOG_WARNING, "Database unavailable\n");
return NULL;
}
memset(&key, 0, sizeof(key));
memset(&data, 0, sizeof(data));
pass = 0;
while (!(res = astdb->seq(astdb, &key, &data, pass++ ? R_NEXT : R_FIRST))) {
if (key.size) {
keys = key.data;
keys[key.size - 1] = '\0';
} else {
keys = "<bad key>";
}
if (data.size) {
values = data.data;
values[data.size - 1] = '\0';
} else {
values = "<bad value>";
}
values_len = strlen(values) + 1;
if (keymatch(keys, prefix) && (cur = ast_malloc(sizeof(*cur) + strlen(keys) + 1 + values_len))) {
cur->next = NULL;
cur->key = cur->data + values_len;
strcpy(cur->data, values);
strcpy(cur->key, keys);
if (last) {
last->next = cur;
} else {
ret = cur;
}
last = cur;
}
}
ast_mutex_unlock(&dblock);
return ret;
}
void ast_db_freetree(struct ast_db_entry *dbe)
{
struct ast_db_entry *last;
while (dbe) {
last = dbe;
dbe = dbe->next;
free(last);
}
}
static char database_show_usage[] =
"Usage: database show [family [keytree]]\n"
" Shows Asterisk database contents, optionally restricted\n"
"to a given family, or family and keytree.\n";
static char database_showkey_usage[] =
"Usage: database showkey <keytree>\n"
" Shows Asterisk database contents, restricted to a given key.\n";
static char database_put_usage[] =
"Usage: database put <family> <key> <value>\n"
" Adds or updates an entry in the Asterisk database for\n"
"a given family, key, and value.\n";
static char database_get_usage[] =
"Usage: database get <family> <key>\n"
" Retrieves an entry in the Asterisk database for a given\n"
"family and key.\n";
static char database_del_usage[] =
"Usage: database del <family> <key>\n"
" Deletes an entry in the Asterisk database for a given\n"
"family and key.\n";
static char database_deltree_usage[] =
"Usage: database deltree <family> [keytree]\n"
" Deletes a family or specific keytree within a family\n"
"in the Asterisk database.\n";
struct ast_cli_entry cli_database[] = {
{ { "database", "show", NULL },
database_show, "Shows database contents",
database_show_usage },
{ { "database", "showkey", NULL },
database_showkey, "Shows database contents",
database_showkey_usage },
{ { "database", "get", NULL },
database_get, "Gets database value",
database_get_usage },
{ { "database", "put", NULL },
database_put, "Adds/updates database value",
database_put_usage },
{ { "database", "del", NULL },
database_del, "Removes database key/value",
database_del_usage },
{ { "database", "deltree", NULL },
database_deltree, "Removes database keytree/values",
database_deltree_usage },
};
static int manager_dbput(struct mansession *s, const struct message *m)
{
const char *family = astman_get_header(m, "Family");
const char *key = astman_get_header(m, "Key");
const char *val = astman_get_header(m, "Val");
int res;
if (ast_strlen_zero(family)) {
astman_send_error(s, m, "No family specified");
return 0;
}
if (ast_strlen_zero(key)) {
astman_send_error(s, m, "No key specified");
return 0;
}
res = ast_db_put(family, key, (char *) S_OR(val, ""));
if (res) {
astman_send_error(s, m, "Failed to update entry");
} else {
astman_send_ack(s, m, "Updated database successfully");
}
return 0;
}
static int manager_dbget(struct mansession *s, const struct message *m)
{
const char *id = astman_get_header(m,"ActionID");
char idText[256] = "";
const char *family = astman_get_header(m, "Family");
const char *key = astman_get_header(m, "Key");
char tmp[256];
int res;
if (ast_strlen_zero(family)) {
astman_send_error(s, m, "No family specified.");
return 0;
}
if (ast_strlen_zero(key)) {
astman_send_error(s, m, "No key specified.");
return 0;
}
if (!ast_strlen_zero(id))
snprintf(idText, sizeof(idText) ,"ActionID: %s\r\n", id);
res = ast_db_get(family, key, tmp, sizeof(tmp));
if (res) {
astman_send_error(s, m, "Database entry not found");
} else {
astman_send_ack(s, m, "Result will follow");
astman_append(s, "Event: DBGetResponse\r\n"
"Family: %s\r\n"
"Key: %s\r\n"
"Val: %s\r\n"
"%s"
"\r\n",
family, key, tmp, idText);
}
return 0;
}
int astdb_init(void)
{
dbinit();
ast_cli_register_multiple(cli_database, sizeof(cli_database) / sizeof(struct ast_cli_entry));
ast_manager_register("DBGet", EVENT_FLAG_SYSTEM, manager_dbget, "Get DB Entry");
ast_manager_register("DBPut", EVENT_FLAG_SYSTEM, manager_dbput, "Put DB Entry");
return 0;
}