cel_sqlite3_custom.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2007, Digium, Inc.
 *
 * Steve Murphy <murf@digium.com> borrowed code from cdr,
 * Mark Spencer <markster@digium.com> and others.
 *
 * 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 Custom SQLite3 CEL records.
 *
 * \author Adapted by Steve Murphy <murf@digium.com> from
 *  Alejandro Rios <alejandro.rios@avatar.com.co> and
 *  Russell Bryant <russell@digium.com> from
 *  cdr_mysql_custom by Edward Eastman <ed@dm3.co.uk>,
 *  and cdr_sqlite by Holger Schurig <hs4233@mail.mn-solutions.de>
 * \ingroup cel_drivers
 */
 
/*** MODULEINFO
    <depend>sqlite3</depend>
    <support_level>extended</support_level>
 ***/
 
#include "asterisk.h"
 
#include <sqlite3.h>
 
#include "asterisk/paths.h"
#include "asterisk/channel.h"
#include "asterisk/cel.h"
#include "asterisk/module.h"
#include "asterisk/config.h"
#include "asterisk/pbx.h"
#include "asterisk/logger.h"
#include "asterisk/utils.h"
#include "asterisk/cli.h"
#include "asterisk/options.h"
#include "asterisk/stringfields.h"
 
#define SQLITE_BACKEND_NAME "CEL sqlite3 custom backend"
 
AST_MUTEX_DEFINE_STATIC(lock);
 
static const char config_file[] = "cel_sqlite3_custom.conf";
 
static sqlite3 *db = NULL;
 
static char table[80];
/*!
 * \bug Handling of this var is crash prone on reloads
 */
static char *columns;
static int busy_timeout;
 
struct values {
    char *expression;
    AST_LIST_ENTRY(values) list;
};
 
static AST_LIST_HEAD_STATIC(sql_values, values);
 
static void free_config(void);
 
static int load_column_config(const char *tmp)
{
    char *col = NULL;
    char *cols = NULL, *save = NULL;
    char *escaped = NULL;
    struct ast_str *column_string = NULL;
 
    if (ast_strlen_zero(tmp)) {
        ast_log(LOG_WARNING, "Column names not specified. Module not loaded.\n");
        return -1;
    }
    if (!(column_string = ast_str_create(1024))) {
        ast_log(LOG_ERROR, "Out of memory creating temporary buffer for column list for table '%s.'\n", table);
        return -1;
    }
    if (!(save = cols = ast_strdup(tmp))) {
        ast_log(LOG_ERROR, "Out of memory creating temporary buffer for column list for table '%s.'\n", table);
        ast_free(column_string);
        return -1;
    }
    while ((col = strsep(&cols, ","))) {
        col = ast_strip(col);
        escaped = sqlite3_mprintf("%q", col);
        if (!escaped) {
            ast_log(LOG_ERROR, "Out of memory creating entry for column '%s' in table '%s.'\n", col, table);
            ast_free(column_string);
            ast_free(save);
            return -1;
        }
        ast_str_append(&column_string, 0, "%s%s", ast_str_strlen(column_string) ? "," : "", escaped);
        sqlite3_free(escaped);
    }
    if (!(columns = ast_strdup(ast_str_buffer(column_string)))) {
        ast_log(LOG_ERROR, "Out of memory copying columns string for table '%s.'\n", table);
        ast_free(column_string);
        ast_free(save);
        return -1;
    }
    ast_free(column_string);
    ast_free(save);
 
    return 0;
}
 
static int load_values_config(const char *tmp)
{
    char *val = NULL;
    char *vals = NULL, *save = NULL;
    struct values *value = NULL;
 
    if (ast_strlen_zero(tmp)) {
        ast_log(LOG_WARNING, "Values not specified. Module not loaded.\n");
        return -1;
    }
    if (!(save = vals = ast_strdup(tmp))) {
        ast_log(LOG_ERROR, "Out of memory creating temporary buffer for value '%s'\n", tmp);
        return -1;
    }
    while ((val = strsep(&vals, ","))) {
        /* Strip the single quotes off if they are there */
        val = ast_strip_quoted(val, "'", "'");
        value = ast_calloc(sizeof(char), sizeof(*value) + strlen(val) + 1);
        if (!value) {
            ast_log(LOG_ERROR, "Out of memory creating entry for value '%s'\n", val);
            ast_free(save);
            return -1;
        }
        value->expression = (char *) value + sizeof(*value);
        ast_copy_string(value->expression, val, strlen(val) + 1);
        AST_LIST_INSERT_TAIL(&sql_values, value, list);
    }
    ast_free(save);
 
    return 0;
}
 
static int load_config(int reload)
{
    struct ast_config *cfg;
    struct ast_flags config_flags = { reload ? CONFIG_FLAG_FILEUNCHANGED : 0 };
    struct ast_variable *mappingvar;
    const char *tmp;
 
    if ((cfg = ast_config_load(config_file, config_flags)) == CONFIG_STATUS_FILEMISSING || cfg == CONFIG_STATUS_FILEINVALID) {
        ast_log(LOG_WARNING, "Failed to %sload configuration file. %s\n",
            reload ? "re" : "", reload ? "" : "Module not activated.");
        return -1;
    } else if (cfg == CONFIG_STATUS_FILEUNCHANGED) {
        return 0;
    }
 
    if (reload) {
        free_config();
    }
 
    if (!(mappingvar = ast_variable_browse(cfg, "master"))) {
        /* Nothing configured */
        ast_config_destroy(cfg);
        return -1;
    }
 
    /* Mapping must have a table name */
    if (!ast_strlen_zero(tmp = ast_variable_retrieve(cfg, "master", "table"))) {
        ast_copy_string(table, tmp, sizeof(table));
    } else {
        ast_log(LOG_WARNING, "Table name not specified.  Assuming cel.\n");
        strcpy(table, "cel");
    }
 
    /* sqlite3_busy_timeout in miliseconds */
    if ((tmp = ast_variable_retrieve(cfg, "master", "busy_timeout")) != NULL) {
        if (ast_parse_arg(tmp, PARSE_INT32|PARSE_DEFAULT, &busy_timeout, 1000) != 0) {
            ast_log(LOG_WARNING, "Invalid busy_timeout value '%s' specified. Using 1000 instead.\n", tmp);
        }
    } else {
        busy_timeout = 1000;
    }
 
    /* Columns */
    if (load_column_config(ast_variable_retrieve(cfg, "master", "columns"))) {
        ast_config_destroy(cfg);
        free_config();
        return -1;
    }
 
    /* Values */
    if (load_values_config(ast_variable_retrieve(cfg, "master", "values"))) {
        ast_config_destroy(cfg);
        free_config();
        return -1;
    }
 
    ast_verb(3, "Logging CEL records to table '%s' in 'master.db'\n", table);
 
    ast_config_destroy(cfg);
 
    return 0;
}
 
static void free_config(void)
{
    struct values *value;
 
    if (db) {
        sqlite3_close(db);
        db = NULL;
    }
 
    if (columns) {
        ast_free(columns);
        columns = NULL;
    }
 
    while ((value = AST_LIST_REMOVE_HEAD(&sql_values, list))) {
        ast_free(value);
    }
}
 
static void write_cel(struct ast_event *event)
{
    char *error = NULL;
    char *sql = NULL;
 
    if (db == NULL) {
        /* Should not have loaded, but be failsafe. */
        return;
    }
 
    ast_mutex_lock(&lock);
 
    { /* Make it obvious that only sql should be used outside of this block */
        char *escaped;
        char subst_buf[2048];
        struct values *value;
        struct ast_channel *dummy;
        struct ast_str *value_string = ast_str_create(1024);
 
        dummy = ast_cel_fabricate_channel_from_event(event);
        if (!dummy) {
            ast_log(LOG_ERROR, "Unable to fabricate channel from CEL event.\n");
            ast_free(value_string);
            ast_mutex_unlock(&lock);
            return;
        }
        AST_LIST_TRAVERSE(&sql_values, value, list) {
            pbx_substitute_variables_helper(dummy, value->expression, subst_buf, sizeof(subst_buf) - 1);
            escaped = sqlite3_mprintf("%q", subst_buf);
            ast_str_append(&value_string, 0, "%s'%s'", ast_str_strlen(value_string) ? "," : "", escaped);
            sqlite3_free(escaped);
        }
        sql = sqlite3_mprintf("INSERT INTO %q (%s) VALUES (%s)", table, columns, ast_str_buffer(value_string));
        ast_debug(1, "About to log: %s\n", sql);
        dummy = ast_channel_unref(dummy);
        ast_free(value_string);
    }
 
    if (sqlite3_exec(db, sql, NULL, NULL, &error) != SQLITE_OK) {
        ast_log(LOG_ERROR, "%s. SQL: %s.\n", error, sql);
        sqlite3_free(error);
    }
 
    if (sql) {
        sqlite3_free(sql);
    }
    ast_mutex_unlock(&lock);
 
    return;
}
 
static int unload_module(void)
{
    ast_cel_backend_unregister(SQLITE_BACKEND_NAME);
 
    free_config();
 
    return 0;
}
 
static int load_module(void)
{
    char *error;
    char filename[PATH_MAX];
    int res;
    char *sql;
 
    if (load_config(0)) {
        return AST_MODULE_LOAD_DECLINE;
    }
 
    /* is the database there? */
    snprintf(filename, sizeof(filename), "%s/master.db", ast_config_AST_LOG_DIR);
    res = sqlite3_open(filename, &db);
    if (res != SQLITE_OK) {
        ast_log(LOG_ERROR, "Could not open database %s.\n", filename);
        free_config();
        return AST_MODULE_LOAD_DECLINE;
    }
    sqlite3_busy_timeout(db, busy_timeout);
    /* is the table there? */
    sql = sqlite3_mprintf("SELECT COUNT(*) FROM %q;", table);
    res = sqlite3_exec(db, sql, NULL, NULL, NULL);
    sqlite3_free(sql);
    if (res != SQLITE_OK) {
        /* We don't use %q for the column list here since we already escaped when building it */
        sql = sqlite3_mprintf("CREATE TABLE %q (AcctId INTEGER PRIMARY KEY, %s)", table, columns);
        res = sqlite3_exec(db, sql, NULL, NULL, &error);
        sqlite3_free(sql);
        if (res != SQLITE_OK) {
            ast_log(LOG_WARNING, "Unable to create table '%s': %s.\n", table, error);
            sqlite3_free(error);
            free_config();
            return AST_MODULE_LOAD_DECLINE;
        }
    }
 
    if (ast_cel_backend_register(SQLITE_BACKEND_NAME, write_cel)) {
        ast_log(LOG_ERROR, "Unable to register custom SQLite3 CEL handling\n");
        free_config();
        return AST_MODULE_LOAD_DECLINE;
    }
 
    return AST_MODULE_LOAD_SUCCESS;
}
 
static int reload(void)
{
    int res = 0;
 
    ast_mutex_lock(&lock);
    res = load_config(1);
    ast_mutex_unlock(&lock);
 
    return res;
}
 
AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "SQLite3 Custom CEL Module",
    .support_level = AST_MODULE_SUPPORT_EXTENDED,
    .load = load_module,
    .unload = unload_module,
    .reload = reload,
    .load_pri = AST_MODPRI_CDR_DRIVER,
    .requires = "cel",
);