cel_pgsql.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2008
 *
 * Steve Murphy - adapted to CEL, from:
 * Matthew D. Hardeman <mhardemn@papersoft.com>
 * Adapted from the MySQL CDR logger originally by James Sharp
 *
 * Modified April, 2007; Dec, 2008
 * Steve Murphy <murf@digium.com>
 
 * Modified September 2003
 * Matthew D. Hardeman <mhardemn@papersoft.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 PostgreSQL CEL logger
 *
 * \author Steve Murphy <murf@digium.com>
 * PostgreSQL http://www.postgresql.org/
 * \ingroup cel_drivers
 */
 
/*** MODULEINFO
    <depend>pgsql</depend>
    <support_level>extended</support_level>
 ***/
 
#include "asterisk.h"
 
#include <libpq-fe.h>
 
#include "asterisk/config.h"
#include "asterisk/options.h"
#include "asterisk/channel.h"
#include "asterisk/cel.h"
#include "asterisk/module.h"
#include "asterisk/logger.h"
#include "asterisk.h"
 
#define DATE_FORMAT "%Y-%m-%d %T.%6q"
 
#define PGSQL_BACKEND_NAME "CEL PGSQL backend"
 
#define PGSQL_MIN_VERSION_SCHEMA 70300
 
static char *config = "cel_pgsql.conf";
 
static char *pghostname;
static char *pgdbname;
static char *pgdbuser;
static char *pgpassword;
static char *pgappname;
static char *pgdbport;
static char *table;
static char *schema;
 
static int connected = 0;
/* Optimization to reduce number of memory allocations */
static int maxsize = 512, maxsize2 = 512;
static int usegmtime = 0;
 
/*! \brief show_user_def is off by default */
#define CEL_SHOW_USERDEF_DEFAULT    0
 
/*! TRUE if we should set the eventtype field to USER_DEFINED on user events. */
static unsigned char cel_show_user_def;
 
AST_MUTEX_DEFINE_STATIC(pgsql_lock);
 
static PGconn   *conn = NULL;
static PGresult *result = NULL;
 
struct columns {
    char *name;
    char *type;
    int len;
    unsigned int notnull:1;
    unsigned int hasdefault:1;
    AST_RWLIST_ENTRY(columns) list;
};
 
static AST_RWLIST_HEAD_STATIC(psql_columns, columns);
 
#define LENGTHEN_BUF(size, var_sql) \
    do { \
        /* Lengthen buffer, if necessary */ \
        if (ast_str_strlen(var_sql) + size + 1 > ast_str_size(var_sql)) { \
            if (ast_str_make_space(&var_sql, ((ast_str_size(var_sql) + size + 3) / 512 + 1) * 512) != 0) { \
                ast_log(LOG_ERROR, "Unable to allocate sufficient memory.  Insert CEL '%s:%s' failed.\n", pghostname, table); \
                ast_free(sql); \
                ast_free(sql2); \
                AST_RWLIST_UNLOCK(&psql_columns); \
                return; \
            } \
        } \
    } while (0)
 
#define LENGTHEN_BUF1(size) \
    LENGTHEN_BUF(size, sql);
#define LENGTHEN_BUF2(size) \
    LENGTHEN_BUF(size, sql2);
 
static void pgsql_reconnect(void)
{
    struct ast_str *conn_info = ast_str_create(128);
    if (!conn_info) {
        ast_log(LOG_ERROR, "Failed to allocate memory for connection string.\n");
        return;
    }
 
    if (conn) {
        PQfinish(conn);
        conn = NULL;
    }
 
    ast_str_set(&conn_info, 0, "host=%s port=%s dbname=%s user=%s",
        pghostname, pgdbport, pgdbname, pgdbuser);
 
    if (!ast_strlen_zero(pgappname)) {
        ast_str_append(&conn_info, 0, " application_name=%s", pgappname);
    }
 
    if (!ast_strlen_zero(pgpassword)) {
        ast_str_append(&conn_info, 0, " password=%s", pgpassword);
    }
 
    conn = PQconnectdb(ast_str_buffer(conn_info));
    ast_free(conn_info);
}
 
 
static void pgsql_log(struct ast_event *event)
{
    struct ast_tm tm;
    char timestr[128];
    char *pgerror;
    struct ast_cel_event_record record = {
        .version = AST_CEL_EVENT_RECORD_VERSION,
    };
 
    if (ast_cel_fill_record(event, &record)) {
        return;
    }
 
    ast_mutex_lock(&pgsql_lock);
 
    ast_localtime(&record.event_time, &tm, usegmtime ? "GMT" : NULL);
    ast_strftime(timestr, sizeof(timestr), DATE_FORMAT, &tm);
 
    if ((!connected) && pghostname && pgdbuser && pgpassword && pgdbname) {
        pgsql_reconnect();
        if (PQstatus(conn) != CONNECTION_BAD) {
            connected = 1;
        } else {
            pgerror = PQerrorMessage(conn);
            ast_log(LOG_ERROR, "cel_pgsql: Unable to connect to database server %s.  Calls will not be logged!\n", pghostname);
            ast_log(LOG_ERROR, "cel_pgsql: Reason: %s\n", pgerror);
            PQfinish(conn);
            conn = NULL;
        }
    }
    if (connected) {
        struct columns *cur;
        struct ast_str *sql = ast_str_create(maxsize), *sql2 = ast_str_create(maxsize2);
        char buf[257];
        char *escapebuf = NULL;
        const char *value;
        int first = 1;
        size_t bufsize = 513;
 
        escapebuf = ast_malloc(bufsize);
        if (!escapebuf || !sql || !sql2) {
            goto ast_log_cleanup;
        }
 
        ast_str_set(&sql, 0, "INSERT INTO %s (", table);
        ast_str_set(&sql2, 0, " VALUES (");
 
#define SEP (first ? "" : ",")
 
        AST_RWLIST_RDLOCK(&psql_columns);
        AST_RWLIST_TRAVERSE(&psql_columns, cur, list) {
            LENGTHEN_BUF1(strlen(cur->name) + 2);
            ast_str_append(&sql, 0, "%s\"%s\"", SEP, cur->name);
 
            if (strcmp(cur->name, "eventtime") == 0) {
                if (strncmp(cur->type, "int", 3) == 0) {
                    LENGTHEN_BUF2(13);
                    ast_str_append(&sql2, 0, "%s%ld", SEP, (long) record.event_time.tv_sec);
                } else if (strncmp(cur->type, "float", 5) == 0) {
                    LENGTHEN_BUF2(31);
                    ast_str_append(&sql2, 0, "%s%f",
                        SEP,
                        (double) record.event_time.tv_sec +
                        (double) record.event_time.tv_usec / 1000000.0);
                } else {
                    /* char, hopefully */
                    LENGTHEN_BUF2(31);
                    ast_localtime(&record.event_time, &tm, usegmtime ? "GMT" : NULL);
                    ast_strftime(buf, sizeof(buf), DATE_FORMAT, &tm);
                    ast_str_append(&sql2, 0, "%s'%s'", SEP, buf);
                }
            } else if (strcmp(cur->name, "eventtype") == 0) {
                if (cur->type[0] == 'i') {
                    /* Get integer, no need to escape anything */
                    LENGTHEN_BUF2(5);
                    ast_str_append(&sql2, 0, "%s%d", SEP, (int) record.event_type);
                } else if (strncmp(cur->type, "float", 5) == 0) {
                    LENGTHEN_BUF2(31);
                    ast_str_append(&sql2, 0, "%s%f", SEP, (double) record.event_type);
                } else {
                    /* Char field, probably */
                    const char *event_name;
                    size_t required_size;
 
                    event_name = (!cel_show_user_def
                        && record.event_type == AST_CEL_USER_DEFINED)
                        ? record.user_defined_name : record.event_name;
                    required_size = strlen(event_name) * 2 + 1;
                    if (required_size > bufsize) {
                        char *tmpbuf = ast_realloc(escapebuf, required_size);
                        if (!tmpbuf) {
                            AST_RWLIST_UNLOCK(&psql_columns);
                            goto ast_log_cleanup;
                        }
                        escapebuf = tmpbuf;
                        bufsize = required_size;
                    }
                    PQescapeStringConn(conn, escapebuf, event_name,
                        strlen(event_name), NULL);
                    LENGTHEN_BUF2(strlen(escapebuf) + 3);
                    ast_str_append(&sql2, 0, "%s'%s'", SEP, escapebuf);
                }
            } else if (strcmp(cur->name, "amaflags") == 0) {
                if (strncmp(cur->type, "int", 3) == 0) {
                    /* Integer, no need to escape anything */
                    LENGTHEN_BUF2(13);
                    ast_str_append(&sql2, 0, "%s%u", SEP, record.amaflag);
                } else {
                    /* Although this is a char field, there are no special characters in the values for these fields */
                    LENGTHEN_BUF2(31);
                    ast_str_append(&sql2, 0, "%s'%u'", SEP, record.amaflag);
                }
            } else {
                /* Arbitrary field, could be anything */
                if (strcmp(cur->name, "userdeftype") == 0) {
                    value = record.user_defined_name;
                } else if (strcmp(cur->name, "cid_name") == 0) {
                    value = record.caller_id_name;
                } else if (strcmp(cur->name, "cid_num") == 0) {
                    value = record.caller_id_num;
                } else if (strcmp(cur->name, "cid_ani") == 0) {
                    value = record.caller_id_ani;
                } else if (strcmp(cur->name, "cid_rdnis") == 0) {
                    value = record.caller_id_rdnis;
                } else if (strcmp(cur->name, "cid_dnid") == 0) {
                    value = record.caller_id_dnid;
                } else if (strcmp(cur->name, "exten") == 0) {
                    value = record.extension;
                } else if (strcmp(cur->name, "context") == 0) {
                    value = record.context;
                } else if (strcmp(cur->name, "channame") == 0) {
                    value = record.channel_name;
                } else if (strcmp(cur->name, "appname") == 0) {
                    value = record.application_name;
                } else if (strcmp(cur->name, "appdata") == 0) {
                    value = record.application_data;
                } else if (strcmp(cur->name, "accountcode") == 0) {
                    value = record.account_code;
                } else if (strcmp(cur->name, "peeraccount") == 0) {
                    value = record.peer_account;
                } else if (strcmp(cur->name, "uniqueid") == 0) {
                    value = record.unique_id;
                } else if (strcmp(cur->name, "linkedid") == 0) {
                    value = record.linked_id;
                } else if (strcmp(cur->name, "userfield") == 0) {
                    value = record.user_field;
                } else if (strcmp(cur->name, "peer") == 0) {
                    value = record.peer;
                } else if (strcmp(cur->name, "extra") == 0) {
                    value = record.extra;
                } else {
                    value = NULL;
                }
 
                if (value == NULL) {
                    ast_str_append(&sql2, 0, "%sDEFAULT", SEP);
                } else if (strncmp(cur->type, "int", 3) == 0) {
                    long long whatever;
                    if (value && sscanf(value, "%30lld", &whatever) == 1) {
                        LENGTHEN_BUF2(26);
                        ast_str_append(&sql2, 0, "%s%lld", SEP, whatever);
                    } else {
                        LENGTHEN_BUF2(2);
                        ast_str_append(&sql2, 0, "%s0", SEP);
                    }
                } else if (strncmp(cur->type, "float", 5) == 0) {
                    long double whatever;
                    if (value && sscanf(value, "%30Lf", &whatever) == 1) {
                        LENGTHEN_BUF2(51);
                        ast_str_append(&sql2, 0, "%s%30Lf", SEP, whatever);
                    } else {
                        LENGTHEN_BUF2(2);
                        ast_str_append(&sql2, 0, "%s0", SEP);
                    }
                    /* XXX Might want to handle dates, times, and other misc fields here XXX */
                } else {
                    if (value) {
                        size_t required_size = strlen(value) * 2 + 1;
 
                        /* If our argument size exceeds our buffer, grow it,
                         * as PQescapeStringConn() expects the buffer to be
                         * adequitely sized and does *NOT* do size checking.
                         */
                        if (required_size > bufsize) {
                            char *tmpbuf = ast_realloc(escapebuf, required_size);
 
                            if (!tmpbuf) {
                                AST_RWLIST_UNLOCK(&psql_columns);
                                goto ast_log_cleanup;
                            }
 
                            escapebuf = tmpbuf;
                            bufsize = required_size;
                        }
                        PQescapeStringConn(conn, escapebuf, value, strlen(value), NULL);
                    } else {
                        escapebuf[0] = '\0';
                    }
                    LENGTHEN_BUF2(strlen(escapebuf) + 3);
                    ast_str_append(&sql2, 0, "%s'%s'", SEP, escapebuf);
                }
            }
            first = 0;
        }
        AST_RWLIST_UNLOCK(&psql_columns);
        LENGTHEN_BUF1(ast_str_strlen(sql2) + 2);
        ast_str_append(&sql, 0, ")%s)", ast_str_buffer(sql2));
 
        ast_debug(3, "Inserting a CEL record: [%s].\n", ast_str_buffer(sql));
        /* Test to be sure we're still connected... */
        /* If we're connected, and connection is working, good. */
        /* Otherwise, attempt reconnect.  If it fails... sorry... */
        if (PQstatus(conn) == CONNECTION_OK) {
            connected = 1;
        } else {
            ast_log(LOG_WARNING, "Connection was lost... attempting to reconnect.\n");
            PQreset(conn);
            if (PQstatus(conn) == CONNECTION_OK) {
                ast_log(LOG_NOTICE, "Connection reestablished.\n");
                connected = 1;
            } else {
                pgerror = PQerrorMessage(conn);
                ast_log(LOG_ERROR, "Unable to reconnect to database server %s. Calls will not be logged!\n", pghostname);
                ast_log(LOG_ERROR, "Reason: %s\n", pgerror);
                PQfinish(conn);
                conn = NULL;
                connected = 0;
                goto ast_log_cleanup;
            }
        }
        result = PQexec(conn, ast_str_buffer(sql));
        if (PQresultStatus(result) != PGRES_COMMAND_OK) {
            pgerror = PQresultErrorMessage(result);
            ast_log(LOG_WARNING, "Failed to insert call detail record into database!\n");
            ast_log(LOG_WARNING, "Reason: %s\n", pgerror);
            ast_log(LOG_WARNING, "Connection may have been lost... attempting to reconnect.\n");
            PQreset(conn);
            if (PQstatus(conn) == CONNECTION_OK) {
                ast_log(LOG_NOTICE, "Connection reestablished.\n");
                connected = 1;
                PQclear(result);
                result = PQexec(conn, ast_str_buffer(sql));
                if (PQresultStatus(result) != PGRES_COMMAND_OK) {
                    pgerror = PQresultErrorMessage(result);
                    ast_log(LOG_ERROR, "HARD ERROR!  Attempted reconnection failed.  DROPPING CALL RECORD!\n");
                    ast_log(LOG_ERROR, "Reason: %s\n", pgerror);
                }
            }
        }
        PQclear(result);
 
        /* Next time, just allocate buffers that are that big to start with. */
        if (ast_str_strlen(sql) > maxsize) {
            maxsize = ast_str_strlen(sql);
        }
        if (ast_str_strlen(sql2) > maxsize2) {
            maxsize2 = ast_str_strlen(sql2);
        }
 
ast_log_cleanup:
        ast_free(sql);
        ast_free(sql2);
        ast_free(escapebuf);
    }
 
    ast_mutex_unlock(&pgsql_lock);
}
 
static int my_unload_module(void)
{
    struct columns *current;
 
    ast_cel_backend_unregister(PGSQL_BACKEND_NAME);
    AST_RWLIST_WRLOCK(&psql_columns);
    if (conn) {
        PQfinish(conn);
        conn = NULL;
    }
    if (pghostname) {
        ast_free(pghostname);
        pghostname = NULL;
    }
    if (pgdbname) {
        ast_free(pgdbname);
        pgdbname = NULL;
    }
    if (pgdbuser) {
        ast_free(pgdbuser);
        pgdbuser = NULL;
    }
    if (pgpassword) {
        ast_free(pgpassword);
        pgpassword = NULL;
    }
    if (pgappname) {
        ast_free(pgappname);
        pgappname = NULL;
    }
    if (pgdbport) {
        ast_free(pgdbport);
        pgdbport = NULL;
    }
    if (table) {
        ast_free(table);
        table = NULL;
    }
    if (schema) {
        ast_free(schema);
        schema = NULL;
    }
    while ((current = AST_RWLIST_REMOVE_HEAD(&psql_columns, list))) {
        ast_free(current);
    }
    AST_RWLIST_UNLOCK(&psql_columns);
    return 0;
}
 
static int unload_module(void)
{
    return my_unload_module();
}
 
static int process_my_load_module(struct ast_config *cfg)
{
    struct ast_variable *var;
    char *pgerror;
    const char *tmp;
    PGresult *result;
    struct columns *cur;
 
    if (!(var = ast_variable_browse(cfg, "global"))) {
        ast_log(LOG_WARNING,"CEL pgsql config file missing global section.\n");
        return AST_MODULE_LOAD_DECLINE;
    }
    if (!(tmp = ast_variable_retrieve(cfg,"global","hostname"))) {
        ast_log(LOG_WARNING,"PostgreSQL server hostname not specified.  Assuming unix socket connection\n");
        tmp = "";   /* connect via UNIX-socket by default */
    }
    if (pghostname)
        ast_free(pghostname);
    if (!(pghostname = ast_strdup(tmp))) {
        ast_log(LOG_WARNING,"PostgreSQL Ran out of memory copying host info\n");
        return AST_MODULE_LOAD_DECLINE;
    }
    if (!(tmp = ast_variable_retrieve(cfg, "global", "dbname"))) {
        ast_log(LOG_WARNING,"PostgreSQL database not specified.  Assuming asterisk\n");
        tmp = "asteriskceldb";
    }
    if (pgdbname)
        ast_free(pgdbname);
    if (!(pgdbname = ast_strdup(tmp))) {
        ast_log(LOG_WARNING,"PostgreSQL Ran out of memory copying dbname info\n");
        return AST_MODULE_LOAD_DECLINE;
    }
    if (!(tmp = ast_variable_retrieve(cfg, "global", "user"))) {
        ast_log(LOG_WARNING,"PostgreSQL database user not specified.  Assuming asterisk\n");
        tmp = "asterisk";
    }
    if (pgdbuser)
        ast_free(pgdbuser);
    if (!(pgdbuser = ast_strdup(tmp))) {
        ast_log(LOG_WARNING,"PostgreSQL Ran out of memory copying user info\n");
        return AST_MODULE_LOAD_DECLINE;
    }
    if (!(tmp = ast_variable_retrieve(cfg, "global", "password"))) {
        ast_log(LOG_WARNING, "PostgreSQL database password not specified.  Assuming blank\n");
        tmp = "";
    }
    if (pgpassword)
        ast_free(pgpassword);
    if (!(pgpassword = ast_strdup(tmp))) {
        ast_log(LOG_WARNING,"PostgreSQL Ran out of memory copying password info\n");
        return AST_MODULE_LOAD_DECLINE;
    }
    if (!(tmp = ast_variable_retrieve(cfg, "global", "appname"))) {
        tmp = "";
    }
    if (pgappname) {
        ast_free(pgappname);
    }
    if (!(pgappname = ast_strdup(tmp))) {
        ast_log(LOG_WARNING,"PostgreSQL Ran out of memory copying appname info\n");
        return AST_MODULE_LOAD_DECLINE;
    }
 
    if (!(tmp = ast_variable_retrieve(cfg,"global","port"))) {
        ast_log(LOG_WARNING,"PostgreSQL database port not specified.  Using default 5432.\n");
        tmp = "5432";
    }
    if (pgdbport)
        ast_free(pgdbport);
    if (!(pgdbport = ast_strdup(tmp))) {
        ast_log(LOG_WARNING,"PostgreSQL Ran out of memory copying port info\n");
        return AST_MODULE_LOAD_DECLINE;
    }
    if (!(tmp = ast_variable_retrieve(cfg, "global", "table"))) {
        ast_log(LOG_WARNING,"CEL table not specified.  Assuming cel\n");
        tmp = "cel";
    }
    if (table)
        ast_free(table);
    if (!(table = ast_strdup(tmp))) {
        return AST_MODULE_LOAD_DECLINE;
    }
    cel_show_user_def = CEL_SHOW_USERDEF_DEFAULT;
    if ((tmp = ast_variable_retrieve(cfg, "global", "show_user_defined"))) {
        cel_show_user_def = ast_true(tmp) ? 1 : 0;
    }
    if ((tmp = ast_variable_retrieve(cfg, "global", "usegmtime"))) {
        usegmtime = ast_true(tmp);
    } else {
        usegmtime = 0;
    }
    if (!(tmp = ast_variable_retrieve(cfg, "global", "schema"))) {
        tmp = "";
    }
    if (schema) {
        ast_free(schema);
    }
    if (!(schema = ast_strdup(tmp))) {
        ast_log(LOG_WARNING,"PostgreSQL Ran out of memory copying schema info\n");
        return AST_MODULE_LOAD_DECLINE;
    }
    if (DEBUG_ATLEAST(3)) {
        if (ast_strlen_zero(pghostname)) {
            ast_log(LOG_DEBUG, "cel_pgsql: using default unix socket\n");
        } else {
            ast_log(LOG_DEBUG, "cel_pgsql: got hostname of %s\n", pghostname);
        }
        ast_log(LOG_DEBUG, "cel_pgsql: got port of %s\n", pgdbport);
        ast_log(LOG_DEBUG, "cel_pgsql: got user of %s\n", pgdbuser);
        ast_log(LOG_DEBUG, "cel_pgsql: got dbname of %s\n", pgdbname);
        ast_log(LOG_DEBUG, "cel_pgsql: got password of %s\n", pgpassword);
        ast_log(LOG_DEBUG, "cel_pgsql: got sql table name of %s\n", table);
        ast_log(LOG_DEBUG, "cel_pgsql: got show_user_defined of %s\n",
            cel_show_user_def ? "Yes" : "No");
    }
 
    pgsql_reconnect();
    if (PQstatus(conn) != CONNECTION_BAD) {
        char sqlcmd[768];
        char *fname, *ftype, *flen, *fnotnull, *fdef, *tablename, *tmp_tablename;
        int i, rows, version;
 
        ast_debug(1, "Successfully connected to PostgreSQL database.\n");
        connected = 1;
 
        version = PQserverVersion(conn);
        /* Remove any schema name from the table */
        if ((tmp_tablename = strrchr(table, '.'))) {
            tmp_tablename++;
        } else {
            tmp_tablename = table;
        }
        tablename = ast_alloca(strlen(tmp_tablename) * 2 + 1);
        PQescapeStringConn(conn, tablename, tmp_tablename, strlen(tmp_tablename), NULL);
        if (version >= PGSQL_MIN_VERSION_SCHEMA) {
            char *schemaname;
            int lenschema;
            lenschema = strlen(schema);
            schemaname = ast_alloca(lenschema * 2 + 1);
            PQescapeStringConn(conn, schemaname, schema, lenschema, NULL);
 
            snprintf(sqlcmd, sizeof(sqlcmd),
            "SELECT a.attname, t.typname, a.attlen, a.attnotnull, pg_catalog.pg_get_expr(d.adbin, d.adrelid) adsrc, a.atttypmod "
            "FROM (((pg_catalog.pg_class c INNER JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace "
                     "AND c.relname = '%s' AND n.nspname = %s%s%s) "
                   "INNER JOIN pg_catalog.pg_attribute a ON ("
                       "NOT a.attisdropped) AND a.attnum > 0 AND a.attrelid = c.oid) "
                "INNER JOIN pg_catalog.pg_type t ON t.oid = a.atttypid) "
            "LEFT OUTER JOIN pg_attrdef d ON a.atthasdef AND d.adrelid = a.attrelid "
              "AND d.adnum = a.attnum "
            "ORDER BY n.nspname, c.relname, attnum",
                tablename,
                lenschema == 0 ? "" : "'", lenschema == 0 ? "current_schema()" : schemaname, lenschema == 0 ? "" : "'");
        } else {
            snprintf(sqlcmd, sizeof(sqlcmd),
            "SELECT a.attname, t.typname, a.attlen, a.attnotnull, d.adsrc, a.atttypmod "
            "FROM pg_class c, pg_type t, pg_attribute a "
            "LEFT OUTER JOIN pg_attrdef d ON a.atthasdef AND d.adrelid = a.attrelid "
            "AND d.adnum = a.attnum WHERE c.oid = a.attrelid AND a.atttypid = t.oid "
            "AND (a.attnum > 0) AND c.relname = '%s' ORDER BY c.relname, attnum", tablename);
        }
        /* Query the columns */
        result = PQexec(conn, sqlcmd);
        if (PQresultStatus(result) != PGRES_TUPLES_OK) {
            pgerror = PQresultErrorMessage(result);
            ast_log(LOG_ERROR, "Failed to query database columns: %s\n", pgerror);
            PQclear(result);
            unload_module();
            return AST_MODULE_LOAD_DECLINE;
        }
 
        rows = PQntuples(result);
        for (i = 0; i < rows; i++) {
            fname = PQgetvalue(result, i, 0);
            ftype = PQgetvalue(result, i, 1);
            flen = PQgetvalue(result, i, 2);
            fnotnull = PQgetvalue(result, i, 3);
            fdef = PQgetvalue(result, i, 4);
            ast_verb(4, "Found column '%s' of type '%s'\n", fname, ftype);
            cur = ast_calloc(1, sizeof(*cur) + strlen(fname) + strlen(ftype) + 2);
            if (cur) {
                sscanf(flen, "%30d", &cur->len);
                cur->name = (char *)cur + sizeof(*cur);
                cur->type = (char *)cur + sizeof(*cur) + strlen(fname) + 1;
                strcpy(cur->name, fname);
                strcpy(cur->type, ftype);
                if (*fnotnull == 't') {
                    cur->notnull = 1;
                } else {
                    cur->notnull = 0;
                }
                if (!ast_strlen_zero(fdef)) {
                    cur->hasdefault = 1;
                } else {
                    cur->hasdefault = 0;
                }
                AST_RWLIST_INSERT_TAIL(&psql_columns, cur, list);
            }
        }
        PQclear(result);
    } else {
        pgerror = PQerrorMessage(conn);
        ast_log(LOG_ERROR, "cel_pgsql: Unable to connect to database server %s.  CALLS WILL NOT BE LOGGED!!\n", pghostname);
        ast_log(LOG_ERROR, "cel_pgsql: Reason: %s\n", pgerror);
        connected = 0;
        PQfinish(conn);
        conn = NULL;
    }
    return AST_MODULE_LOAD_SUCCESS;
}
 
static int my_load_module(int reload)
{
    struct ast_config *cfg;
    struct ast_flags config_flags = { reload ? CONFIG_FLAG_FILEUNCHANGED : 0 };
 
    if ((cfg = ast_config_load(config, config_flags)) == NULL || cfg == CONFIG_STATUS_FILEINVALID) {
        ast_log(LOG_WARNING, "Unable to load config for PostgreSQL CEL's: %s\n", config);
        return AST_MODULE_LOAD_DECLINE;
    } else if (cfg == CONFIG_STATUS_FILEUNCHANGED) {
        return AST_MODULE_LOAD_SUCCESS;
    }
 
    if (reload) {
        my_unload_module();
    }
 
    process_my_load_module(cfg);
    ast_config_destroy(cfg);
 
    if (ast_cel_backend_register(PGSQL_BACKEND_NAME, pgsql_log)) {
        ast_log(LOG_WARNING, "Unable to subscribe to CEL events for pgsql\n");
        return AST_MODULE_LOAD_DECLINE;
    }
 
    return AST_MODULE_LOAD_SUCCESS;
}
 
static int load_module(void)
{
    return my_load_module(0);
}
 
static int reload(void)
{
    return my_load_module(1);
}
 
AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "PostgreSQL CEL Backend",
    .support_level = AST_MODULE_SUPPORT_EXTENDED,
    .load = load_module,
    .unload = unload_module,
    .reload = reload,
    .load_pri = AST_MODPRI_CDR_DRIVER,
    .requires = "cel",
);