cel_odbc.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2008 Digium
 *
 * Adapted from cdr_adaptive_odbc:
 * Tilghman Lesher <tlesher AT digium DOT com>
 * by Steve Murphy
 *
 * 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 ODBC CEL backend
 *
 * \author Tilghman Lesher \verbatim <tlesher AT digium DOT com> \endverbatim
 * \ingroup cel_drivers
 */
 
/*** MODULEINFO
    <depend>res_odbc</depend>
    <depend>generic_odbc</depend>
    <support_level>core</support_level>
 ***/
 
#include "asterisk.h"
 
#include <sys/types.h>
#include <time.h>
#include <math.h>
 
#include <sql.h>
#include <sqlext.h>
#include <sqltypes.h>
 
#include "asterisk/config.h"
#include "asterisk/channel.h"
#include "asterisk/lock.h"
#include "asterisk/linkedlists.h"
#include "asterisk/res_odbc.h"
#include "asterisk/cel.h"
#include "asterisk/module.h"
 
#define CONFIG  "cel_odbc.conf"
 
#define ODBC_BACKEND_NAME "ODBC CEL backend"
 
/*! \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;
 
/* Optimization to reduce number of memory allocations */
static int maxsize = 512, maxsize2 = 512;
 
struct columns {
    char *name;
    char *celname;
    char *filtervalue;
    char *staticvalue;
    SQLSMALLINT type;
    SQLINTEGER size;
    SQLSMALLINT decimals;
    SQLSMALLINT radix;
    SQLSMALLINT nullable;
    SQLINTEGER octetlen;
    AST_LIST_ENTRY(columns) list;
};
 
struct tables {
    char *connection;
    char *table;
    unsigned int usegmtime:1;
    unsigned int allowleapsec:1;
    AST_LIST_HEAD_NOLOCK(odbc_columns, columns) columns;
    AST_RWLIST_ENTRY(tables) list;
};
 
static AST_RWLIST_HEAD_STATIC(odbc_tables, tables);
 
static int load_config(void)
{
    struct ast_config *cfg;
    struct ast_variable *var;
    const char *tmp, *catg;
    struct tables *tableptr;
    struct columns *entry;
    struct odbc_obj *obj;
    char columnname[80];
    char connection[40];
    char table[40];
    int lenconnection, lentable;
    SQLLEN sqlptr;
    int res = 0;
    SQLHSTMT stmt = NULL;
    struct ast_flags config_flags = { 0 }; /* Part of our config comes from the database */
 
    cfg = ast_config_load(CONFIG, config_flags);
    if (!cfg || cfg == CONFIG_STATUS_FILEINVALID) {
        ast_log(LOG_WARNING, "Unable to load " CONFIG ".  No ODBC CEL records!\n");
        return -1;
    }
 
    /* Process the general category */
    cel_show_user_def = CEL_SHOW_USERDEF_DEFAULT;
    for (var = ast_variable_browse(cfg, "general"); var; var = var->next) {
        if (!strcasecmp(var->name, "show_user_defined")) {
            cel_show_user_def = ast_true(var->value) ? 1 : 0;
        } else {
            /* Unknown option name. */
        }
    }
 
    for (catg = ast_category_browse(cfg, NULL); catg; catg = ast_category_browse(cfg, catg)) {
        if (!strcasecmp(catg, "general")) {
            continue;
        }
        var = ast_variable_browse(cfg, catg);
        if (!var)
            continue;
 
        if (ast_strlen_zero(tmp = ast_variable_retrieve(cfg, catg, "connection"))) {
            ast_log(LOG_WARNING, "No connection parameter found in '%s'.  Skipping.\n", catg);
            continue;
        }
        ast_copy_string(connection, tmp, sizeof(connection));
        lenconnection = strlen(connection);
 
        /* When loading, we want to be sure we can connect. */
        obj = ast_odbc_request_obj(connection, 1);
        if (!obj) {
            ast_log(LOG_WARNING, "No such connection '%s' in the '%s' section of " CONFIG ".  Check res_odbc.conf.\n", connection, catg);
            continue;
        }
 
        if (ast_strlen_zero(tmp = ast_variable_retrieve(cfg, catg, "table"))) {
            ast_log(LOG_NOTICE, "No table name found.  Assuming 'cel'.\n");
            tmp = "cel";
        }
        ast_copy_string(table, tmp, sizeof(table));
        lentable = strlen(table);
 
        res = SQLAllocHandle(SQL_HANDLE_STMT, obj->con, &stmt);
        if (!SQL_SUCCEEDED(res)) {
            ast_log(LOG_WARNING, "SQL Alloc Handle failed on connection '%s'!\n", connection);
            ast_odbc_release_obj(obj);
            continue;
        }
 
        res = SQLColumns(stmt, NULL, 0, NULL, 0, (unsigned char *)table, SQL_NTS, (unsigned char *)"%", SQL_NTS);
        if (!SQL_SUCCEEDED(res)) {
            ast_log(LOG_ERROR, "Unable to query database columns on connection '%s'.  Skipping.\n", connection);
            ast_odbc_release_obj(obj);
            continue;
        }
 
        tableptr = ast_calloc(sizeof(char), sizeof(*tableptr) + lenconnection + 1 + lentable + 1);
        if (!tableptr) {
            ast_log(LOG_ERROR, "Out of memory creating entry for table '%s' on connection '%s'\n", table, connection);
            ast_odbc_release_obj(obj);
            res = -1;
            break;
        }
 
        tableptr->connection = (char *)tableptr + sizeof(*tableptr);
        tableptr->table = (char *)tableptr + sizeof(*tableptr) + lenconnection + 1;
        ast_copy_string(tableptr->connection, connection, lenconnection + 1);
        ast_copy_string(tableptr->table, table, lentable + 1);
 
        tableptr->usegmtime = 0;
        if (!ast_strlen_zero(tmp = ast_variable_retrieve(cfg, catg, "usegmtime"))) {
            tableptr->usegmtime = ast_true(tmp);
        }
 
        tableptr->allowleapsec = 1;
        if (!ast_strlen_zero(tmp = ast_variable_retrieve(cfg, catg, "allowleapsecond"))) {
            tableptr->allowleapsec = ast_true(tmp);
        }
 
        ast_verb(3, "Found CEL table %s@%s.\n", tableptr->table, tableptr->connection);
 
        /* Check for filters first */
        for (var = ast_variable_browse(cfg, catg); var; var = var->next) {
            if (strncmp(var->name, "filter", 6) == 0) {
                char *celvar = ast_strdupa(var->name + 6);
                celvar = ast_strip(celvar);
                ast_verb(3, "Found filter %s for cel variable %s in %s@%s\n", var->value, celvar, tableptr->table, tableptr->connection);
 
                entry = ast_calloc(sizeof(char), sizeof(*entry) + strlen(celvar) + 1 + strlen(var->value) + 1);
                if (!entry) {
                    ast_log(LOG_ERROR, "Out of memory creating filter entry for CEL variable '%s' in table '%s' on connection '%s'\n", celvar, table, connection);
                    res = -1;
                    break;
                }
 
                /* NULL column entry means this isn't a column in the database */
                entry->name = NULL;
                entry->celname = (char *)entry + sizeof(*entry);
                entry->filtervalue = (char *)entry + sizeof(*entry) + strlen(celvar) + 1;
                strcpy(entry->celname, celvar);
                strcpy(entry->filtervalue, var->value);
 
                AST_LIST_INSERT_TAIL(&(tableptr->columns), entry, list);
            }
        }
 
        while ((res = SQLFetch(stmt)) != SQL_NO_DATA && res != SQL_ERROR) {
            char *celvar = "", *staticvalue = "";
 
            SQLGetData(stmt,  4, SQL_C_CHAR, columnname, sizeof(columnname), &sqlptr);
 
            /* Is there an alias for this column? */
 
            /* NOTE: This seems like a non-optimal parse method, but I'm going
             * for user configuration readability, rather than fast parsing. We
             * really don't parse this file all that often, anyway.
             */
            for (var = ast_variable_browse(cfg, catg); var; var = var->next) {
                if (strncmp(var->name, "alias", 5) == 0 && strcasecmp(var->value, columnname) == 0) {
                    char *alias = ast_strdupa(var->name + 5);
                    celvar = ast_strip(alias);
                    ast_verb(3, "Found alias %s for column %s in %s@%s\n", celvar, columnname, tableptr->table, tableptr->connection);
                    break;
                } else if (strncmp(var->name, "static", 6) == 0 && strcasecmp(var->value, columnname) == 0) {
                    char *item = ast_strdupa(var->name + 6);
                    item = ast_strip(item);
                    if (item[0] == '"' && item[strlen(item) - 1] == '"') {
                        /* Remove surrounding quotes */
                        item[strlen(item) - 1] = '\0';
                        item++;
                    }
                    staticvalue = item;
                }
            }
 
            entry = ast_calloc(sizeof(char), sizeof(*entry) + strlen(columnname) + 1 + strlen(celvar) + 1 + strlen(staticvalue) + 1);
            if (!entry) {
                ast_log(LOG_ERROR, "Out of memory creating entry for column '%s' in table '%s' on connection '%s'\n", columnname, table, connection);
                res = -1;
                break;
            }
            entry->name = (char *)entry + sizeof(*entry);
            strcpy(entry->name, columnname);
 
            if (!ast_strlen_zero(celvar)) {
                entry->celname = entry->name + strlen(columnname) + 1;
                strcpy(entry->celname, celvar);
            } else { /* Point to same place as the column name */
                entry->celname = (char *)entry + sizeof(*entry);
            }
 
            if (!ast_strlen_zero(staticvalue)) {
                entry->staticvalue = entry->celname + strlen(entry->celname) + 1;
                strcpy(entry->staticvalue, staticvalue);
            }
 
            SQLGetData(stmt,  5, SQL_C_SHORT, &entry->type, sizeof(entry->type), NULL);
            SQLGetData(stmt,  7, SQL_C_LONG, &entry->size, sizeof(entry->size), NULL);
            SQLGetData(stmt,  9, SQL_C_SHORT, &entry->decimals, sizeof(entry->decimals), NULL);
            SQLGetData(stmt, 10, SQL_C_SHORT, &entry->radix, sizeof(entry->radix), NULL);
            SQLGetData(stmt, 11, SQL_C_SHORT, &entry->nullable, sizeof(entry->nullable), NULL);
            SQLGetData(stmt, 16, SQL_C_LONG, &entry->octetlen, sizeof(entry->octetlen), NULL);
 
            /* Specification states that the octenlen should be the maximum number of bytes
             * returned in a char or binary column, but it seems that some drivers just set
             * it to NULL. (Bad Postgres! No biscuit!) */
            if (entry->octetlen == 0)
                entry->octetlen = entry->size;
 
            ast_verb(10, "Found %s column with type %hd with len %ld, octetlen %ld, and numlen (%hd,%hd)\n", entry->name, entry->type, (long) entry->size, (long) entry->octetlen, entry->decimals, entry->radix);
            /* Insert column info into column list */
            AST_LIST_INSERT_TAIL(&(tableptr->columns), entry, list);
            res = 0;
        }
 
        SQLFreeHandle(SQL_HANDLE_STMT, stmt);
        ast_odbc_release_obj(obj);
 
        if (AST_LIST_FIRST(&(tableptr->columns)))
            AST_RWLIST_INSERT_TAIL(&odbc_tables, tableptr, list);
        else
            ast_free(tableptr);
    }
    ast_config_destroy(cfg);
    return res;
}
 
static int free_config(void)
{
    struct tables *table;
    struct columns *entry;
    while ((table = AST_RWLIST_REMOVE_HEAD(&odbc_tables, list))) {
        while ((entry = AST_LIST_REMOVE_HEAD(&(table->columns), list))) {
            ast_free(entry);
        }
        ast_free(table);
    }
    return 0;
}
 
#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 + 1) / 512 + 1) * 512) != 0) { \
                        ast_log(LOG_ERROR, "Unable to allocate sufficient memory.  Insert CEL '%s:%s' failed.\n", tableptr->connection, tableptr->table); \
                        ast_free(sql);                                          \
                        ast_free(sql2);                                         \
                        AST_RWLIST_UNLOCK(&odbc_tables);                        \
                        return;                                                 \
                    }                                                           \
                }                                                               \
            } while (0)
 
#define LENGTHEN_BUF1(size) \
    LENGTHEN_BUF(size, sql);
 
#define LENGTHEN_BUF2(size) \
    LENGTHEN_BUF(size, sql2);
 
static void odbc_log(struct ast_event *event)
{
    struct tables *tableptr;
    struct columns *entry;
    struct odbc_obj *obj;
    struct ast_str *sql = ast_str_create(maxsize), *sql2 = ast_str_create(maxsize2);
    char *tmp;
    char colbuf[1024], *colptr;
    SQLHSTMT stmt = NULL;
    int res;
    struct ast_cel_event_record record = {
        .version = AST_CEL_EVENT_RECORD_VERSION,
    };
 
    if (ast_cel_fill_record(event, &record)) {
        return;
    }
 
    if (!sql || !sql2) {
        if (sql)
            ast_free(sql);
        if (sql2)
            ast_free(sql2);
        return;
    }
 
    if (AST_RWLIST_RDLOCK(&odbc_tables)) {
        ast_log(LOG_ERROR, "Unable to lock table list.  Insert CEL(s) failed.\n");
        ast_free(sql);
        ast_free(sql2);
        return;
    }
 
    AST_LIST_TRAVERSE(&odbc_tables, tableptr, list) {
        char *separator = "";
        ast_str_set(&sql, 0, "INSERT INTO %s (", tableptr->table);
        ast_str_set(&sql2, 0, " VALUES (");
 
        /* No need to check the connection now; we'll handle any failure in prepare_and_execute */
        if (!(obj = ast_odbc_request_obj(tableptr->connection, 0))) {
            ast_log(LOG_WARNING, "Unable to retrieve database handle for '%s:%s'.  CEL failed: %s\n", tableptr->connection, tableptr->table, ast_str_buffer(sql));
            continue;
        }
 
        AST_LIST_TRAVERSE(&(tableptr->columns), entry, list) {
            int datefield = 0;
            int unknown = 0;
            if (strcasecmp(entry->celname, "eventtime") == 0) {
                datefield = 1;
            }
 
            /* Check if we have a similarly named variable */
            if (entry->staticvalue) {
                colptr = ast_strdupa(entry->staticvalue);
            } else if (datefield) {
                struct timeval date_tv = record.event_time;
                struct ast_tm tm = { 0, };
                ast_localtime(&date_tv, &tm, tableptr->usegmtime ? "UTC" : NULL);
                /* SQL server 2008 added datetime2 and datetimeoffset data types, that
                   are reported to SQLColumns() as SQL_WVARCHAR, according to "Enhanced
                   Date/Time Type Behavior with Previous SQL Server Versions (ODBC)".
                   Here we format the event time with fraction seconds, so these new
                   column types will be set to high-precision event time. However, 'date'
                   and 'time' columns, also newly introduced, reported as SQL_WVARCHAR
                   too, and insertion of the value formatted here into these will fail.
                   This should be ok, however, as nobody is going to store just event
                   date or just time for CDR purposes.
                 */
                ast_strftime(colbuf, sizeof(colbuf), "%Y-%m-%d %H:%M:%S.%6q", &tm);
                colptr = colbuf;
            } else {
                if (strcmp(entry->celname, "userdeftype") == 0) {
                    ast_copy_string(colbuf, record.user_defined_name, sizeof(colbuf));
                } else if (strcmp(entry->celname, "cid_name") == 0) {
                    ast_copy_string(colbuf, record.caller_id_name, sizeof(colbuf));
                } else if (strcmp(entry->celname, "cid_num") == 0) {
                    ast_copy_string(colbuf, record.caller_id_num, sizeof(colbuf));
                } else if (strcmp(entry->celname, "cid_ani") == 0) {
                    ast_copy_string(colbuf, record.caller_id_ani, sizeof(colbuf));
                } else if (strcmp(entry->celname, "cid_rdnis") == 0) {
                    ast_copy_string(colbuf, record.caller_id_rdnis, sizeof(colbuf));
                } else if (strcmp(entry->celname, "cid_dnid") == 0) {
                    ast_copy_string(colbuf, record.caller_id_dnid, sizeof(colbuf));
                } else if (strcmp(entry->celname, "exten") == 0) {
                    ast_copy_string(colbuf, record.extension, sizeof(colbuf));
                } else if (strcmp(entry->celname, "context") == 0) {
                    ast_copy_string(colbuf, record.context, sizeof(colbuf));
                } else if (strcmp(entry->celname, "channame") == 0) {
                    ast_copy_string(colbuf, record.channel_name, sizeof(colbuf));
                } else if (strcmp(entry->celname, "appname") == 0) {
                    ast_copy_string(colbuf, record.application_name, sizeof(colbuf));
                } else if (strcmp(entry->celname, "appdata") == 0) {
                    ast_copy_string(colbuf, record.application_data, sizeof(colbuf));
                } else if (strcmp(entry->celname, "accountcode") == 0) {
                    ast_copy_string(colbuf, record.account_code, sizeof(colbuf));
                } else if (strcmp(entry->celname, "peeraccount") == 0) {
                    ast_copy_string(colbuf, record.peer_account, sizeof(colbuf));
                } else if (strcmp(entry->celname, "uniqueid") == 0) {
                    ast_copy_string(colbuf, record.unique_id, sizeof(colbuf));
                } else if (strcmp(entry->celname, "linkedid") == 0) {
                    ast_copy_string(colbuf, record.linked_id, sizeof(colbuf));
                } else if (strcmp(entry->celname, "userfield") == 0) {
                    ast_copy_string(colbuf, record.user_field, sizeof(colbuf));
                } else if (strcmp(entry->celname, "peer") == 0) {
                    ast_copy_string(colbuf, record.peer, sizeof(colbuf));
                } else if (strcmp(entry->celname, "amaflags") == 0) {
                    snprintf(colbuf, sizeof(colbuf), "%u", record.amaflag);
                } else if (strcmp(entry->celname, "extra") == 0) {
                    ast_copy_string(colbuf, record.extra, sizeof(colbuf));
                } else if (strcmp(entry->celname, "eventtype") == 0) {
                    snprintf(colbuf, sizeof(colbuf), "%u", record.event_type);
                } else {
                    colbuf[0] = 0;
                    unknown = 1;
                }
                colptr = colbuf;
            }
 
            if (colptr && !unknown) {
                /* Check first if the column filters this entry.  Note that this
                 * is very specifically NOT ast_strlen_zero(), because the filter
                 * could legitimately specify that the field is blank, which is
                 * different from the field being unspecified (NULL). */
                if (entry->filtervalue && strcasecmp(colptr, entry->filtervalue) != 0) {
                    ast_verb(4, "CEL column '%s' with value '%s' does not match filter of"
                        " '%s'.  Cancelling this CEL.\n",
                        entry->celname, colptr, entry->filtervalue);
                    goto early_release;
                }
 
                /* Only a filter? */
                if (ast_strlen_zero(entry->name))
                    continue;
 
                LENGTHEN_BUF1(strlen(entry->name));
 
                switch (entry->type) {
                case SQL_CHAR:
                case SQL_VARCHAR:
                case SQL_LONGVARCHAR:
#ifdef HAVE_ODBC_WCHAR
                case SQL_WCHAR:
                case SQL_WVARCHAR:
                case SQL_WLONGVARCHAR:
#endif
                case SQL_BINARY:
                case SQL_VARBINARY:
                case SQL_LONGVARBINARY:
                case SQL_GUID:
                    /* For these two field names, get the rendered form, instead of the raw
                     * form (but only when we're dealing with a character-based field).
                     */
                    if (strcasecmp(entry->name, "eventtype") == 0) {
                        const char *event_name;
 
                        event_name = (!cel_show_user_def
                            && record.event_type == AST_CEL_USER_DEFINED)
                            ? record.user_defined_name : record.event_name;
                        snprintf(colbuf, sizeof(colbuf), "%s", event_name);
                    }
 
                    /* Truncate too-long fields */
                    if (entry->type != SQL_GUID) {
                        if (strlen(colptr) > entry->octetlen) {
                            colptr[entry->octetlen] = '\0';
                        }
                    }
 
                    ast_str_append(&sql, 0, "%s%s", separator, entry->name);
                    LENGTHEN_BUF2(strlen(colptr));
 
                    /* Encode value, with escaping */
                    ast_str_append(&sql2, 0, "%s'", separator);
                    for (tmp = colptr; *tmp; tmp++) {
                        if (*tmp == '\'') {
                            ast_str_append(&sql2, 0, "''");
                        } else if (*tmp == '\\' && ast_odbc_backslash_is_escape(obj)) {
                            ast_str_append(&sql2, 0, "\\\\");
                        } else {
                            ast_str_append(&sql2, 0, "%c", *tmp);
                        }
                    }
                    ast_str_append(&sql2, 0, "'");
                    break;
                case SQL_TYPE_DATE:
                    if (ast_strlen_zero(colptr)) {
                        continue;
                    } else {
                        int year = 0, month = 0, day = 0;
                        if (strcasecmp(entry->name, "eventdate") == 0) {
                            struct ast_tm tm;
                            ast_localtime(&record.event_time, &tm, tableptr->usegmtime ? "UTC" : NULL);
                            year = tm.tm_year + 1900;
                            month = tm.tm_mon + 1;
                            day = tm.tm_mday;
                        } else {
                            if (sscanf(colptr, "%4d-%2d-%2d", &year, &month, &day) != 3 || year <= 0 ||
                                month <= 0 || month > 12 || day < 0 || day > 31 ||
                                ((month == 4 || month == 6 || month == 9 || month == 11) && day == 31) ||
                                (month == 2 && year % 400 == 0 && day > 29) ||
                                (month == 2 && year % 100 == 0 && day > 28) ||
                                (month == 2 && year % 4 == 0 && day > 29) ||
                                (month == 2 && year % 4 != 0 && day > 28)) {
                                ast_log(LOG_WARNING, "CEL variable %s is not a valid date ('%s').\n", entry->name, colptr);
                                continue;
                            }
 
                            if (year > 0 && year < 100) {
                                year += 2000;
                            }
                        }
 
                        ast_str_append(&sql, 0, "%s%s", separator, entry->name);
                        LENGTHEN_BUF2(17);
                        ast_str_append(&sql2, 0, "%s{d '%04d-%02d-%02d'}", separator, year, month, day);
                    }
                    break;
                case SQL_TYPE_TIME:
                    if (ast_strlen_zero(colptr)) {
                        continue;
                    } else {
                        int hour = 0, minute = 0, second = 0;
                        if (strcasecmp(entry->name, "eventdate") == 0) {
                            struct ast_tm tm;
                            ast_localtime(&record.event_time, &tm, tableptr->usegmtime ? "UTC" : NULL);
                            hour = tm.tm_hour;
                            minute = tm.tm_min;
                            second = (tableptr->allowleapsec || tm.tm_sec < 60) ? tm.tm_sec : 59;
                        } else {
                            int count = sscanf(colptr, "%2d:%2d:%2d", &hour, &minute, &second);
 
                            if ((count != 2 && count != 3) || hour < 0 || hour > 23 || minute < 0 || minute > 59 || second < 0 || second > (tableptr->allowleapsec ? 60 : 59)) {
                                ast_log(LOG_WARNING, "CEL variable %s is not a valid time ('%s').\n", entry->name, colptr);
                                continue;
                            }
                        }
 
                        ast_str_append(&sql, 0, "%s%s", separator, entry->name);
                        LENGTHEN_BUF2(15);
                        ast_str_append(&sql2, 0, "%s{t '%02d:%02d:%02d'}", separator, hour, minute, second);
                    }
                    break;
                case SQL_TYPE_TIMESTAMP:
                case SQL_TIMESTAMP:
                case SQL_DATETIME:
                    if (ast_strlen_zero(colptr)) {
                        continue;
                    } else {
                        if (datefield) {
                            /*
                             * We've already properly formatted the timestamp so there's no need
                             * to parse it and re-format it.
                             */
                            ast_str_append(&sql, 0, "%s%s", separator, entry->name);
                            LENGTHEN_BUF2(27);
                            ast_str_append(&sql2, 0, "%s{ts '%s'}", separator, colptr);
                        } else {
                            int year = 0, month = 0, day = 0, hour = 0, minute = 0;
                            /* MUST use double for microsecond precision */
                            double second = 0.0;
                            if (strcasecmp(entry->name, "eventdate") == 0) {
                                /*
                                 * There doesn't seem to be any reference to 'eventdate' anywhere
                                 * other than in this module.  It should be considered for removal
                                 * at a later date.
                                 */
                                struct ast_tm tm;
                                ast_localtime(&record.event_time, &tm, tableptr->usegmtime ? "UTC" : NULL);
                                year = tm.tm_year + 1900;
                                month = tm.tm_mon + 1;
                                day = tm.tm_mday;
                                hour = tm.tm_hour;
                                minute = tm.tm_min;
                                second = (tableptr->allowleapsec || tm.tm_sec < 60) ? tm.tm_sec : 59;
                                second += (tm.tm_usec / 1000000.0);
                            } else {
                                /*
                                 * If we're here, the data to be inserted MAY be a timestamp
                                 * but the column is.  We parse as much as we can.
                                 */
                                int count = sscanf(colptr, "%4d-%2d-%2d %2d:%2d:%lf", &year, &month, &day, &hour, &minute, &second);
 
                                if ((count != 3 && count != 5 && count != 6) || year <= 0 ||
                                    month <= 0 || month > 12 || day < 0 || day > 31 ||
                                    ((month == 4 || month == 6 || month == 9 || month == 11) && day == 31) ||
                                    (month == 2 && year % 400 == 0 && day > 29) ||
                                    (month == 2 && year % 100 == 0 && day > 28) ||
                                    (month == 2 && year % 4 == 0 && day > 29) ||
                                    (month == 2 && year % 4 != 0 && day > 28) ||
                                    hour > 23 || minute > 59 || ((int)floor(second)) > (tableptr->allowleapsec ? 60 : 59) ||
                                    hour < 0 || minute < 0 || ((int)floor(second)) < 0) {
                                    ast_log(LOG_WARNING, "CEL variable %s is not a valid timestamp ('%s').\n", entry->name, colptr);
                                    continue;
                                }
 
                                if (year > 0 && year < 100) {
                                    year += 2000;
                                }
                            }
 
                            ast_str_append(&sql, 0, "%s%s", separator, entry->name);
                            LENGTHEN_BUF2(27);
                            ast_str_append(&sql2, 0, "%s{ts '%04d-%02d-%02d %02d:%02d:%09.6lf'}", separator, year, month, day, hour, minute, second);
                        }
                    }
                    break;
                case SQL_INTEGER:
                    {
                        int integer = 0;
                        if (sscanf(colptr, "%30d", &integer) != 1) {
                            ast_log(LOG_WARNING, "CEL variable %s is not an integer.\n", entry->name);
                            continue;
                        }
 
                        ast_str_append(&sql, 0, "%s%s", separator, entry->name);
                        LENGTHEN_BUF2(12);
                        ast_str_append(&sql2, 0, "%s%d", separator, integer);
                    }
                    break;
                case SQL_BIGINT:
                    {
                        long long integer = 0;
                        int ret;
                        if ((ret = sscanf(colptr, "%30lld", &integer)) != 1) {
                            ast_log(LOG_WARNING, "CEL variable %s is not an integer. (%d - '%s')\n", entry->name, ret, colptr);
                            continue;
                        }
 
                        ast_str_append(&sql, 0, "%s%s", separator, entry->name);
                        LENGTHEN_BUF2(24);
                        ast_str_append(&sql2, 0, "%s%lld", separator, integer);
                    }
                    break;
                case SQL_SMALLINT:
                    {
                        short integer = 0;
                        if (sscanf(colptr, "%30hd", &integer) != 1) {
                            ast_log(LOG_WARNING, "CEL variable %s is not an integer.\n", entry->name);
                            continue;
                        }
 
                        ast_str_append(&sql, 0, "%s%s", separator, entry->name);
                        LENGTHEN_BUF2(7);
                        ast_str_append(&sql2, 0, "%s%d", separator, integer);
                    }
                    break;
                case SQL_TINYINT:
                    {
                        signed char integer = 0;
                        if (sscanf(colptr, "%30hhd", &integer) != 1) {
                            ast_log(LOG_WARNING, "CEL variable %s is not an integer.\n", entry->name);
                            continue;
                        }
 
                        ast_str_append(&sql, 0, "%s%s", separator, entry->name);
                        LENGTHEN_BUF2(4);
                        ast_str_append(&sql2, 0, "%s%d", separator, integer);
                    }
                    break;
                case SQL_BIT:
                    {
                        signed char integer = 0;
                        if (sscanf(colptr, "%30hhd", &integer) != 1) {
                            ast_log(LOG_WARNING, "CEL variable %s is not an integer.\n", entry->name);
                            continue;
                        }
                        if (integer != 0)
                            integer = 1;
 
                        ast_str_append(&sql, 0, "%s%s", separator, entry->name);
                        LENGTHEN_BUF2(2);
                        ast_str_append(&sql2, 0, "%s%d", separator, integer);
                    }
                    break;
                case SQL_NUMERIC:
                case SQL_DECIMAL:
                    {
                        double number = 0.0;
                        if (sscanf(colptr, "%30lf", &number) != 1) {
                            ast_log(LOG_WARNING, "CEL variable %s is not an numeric type.\n", entry->name);
                            continue;
                        }
 
                        ast_str_append(&sql, 0, "%s%s", separator, entry->name);
                        LENGTHEN_BUF2(entry->decimals + 2);
                        ast_str_append(&sql2, 0, "%s%*.*lf", separator, entry->decimals, entry->radix, number);
                    }
                    break;
                case SQL_FLOAT:
                case SQL_REAL:
                case SQL_DOUBLE:
                    {
                        double number = 0.0;
                        if (sscanf(colptr, "%30lf", &number) != 1) {
                            ast_log(LOG_WARNING, "CEL variable %s is not an numeric type.\n", entry->name);
                            continue;
                        }
 
                        ast_str_append(&sql, 0, "%s%s", separator, entry->name);
                        LENGTHEN_BUF2(entry->decimals);
                        ast_str_append(&sql2, 0, "%s%lf", separator, number);
                    }
                    break;
                default:
                    ast_log(LOG_WARNING, "Column type %d (field '%s:%s:%s') is unsupported at this time.\n", entry->type, tableptr->connection, tableptr->table, entry->name);
                    continue;
                }
                separator = ", ";
            }
        }
 
        /* Concatenate the two constructed buffers */
        LENGTHEN_BUF1(ast_str_strlen(sql2));
        ast_str_append(&sql, 0, ")");
        ast_str_append(&sql2, 0, ")");
        ast_str_append(&sql, 0, "%s", ast_str_buffer(sql2));
 
        ast_debug(3, "Executing SQL statement: [%s]\n", ast_str_buffer(sql));
 
        /* There is no benefit to prepared statements here as each generated
           INSERT statement is unique. Just execute our query directly. */
        res = SQLAllocHandle(SQL_HANDLE_STMT, obj->con, &stmt);
        if (!SQL_SUCCEEDED(res)) {
            ast_log(LOG_WARNING, "SQL Alloc Handle failed on connection '%s'!\n",
                tableptr->connection);
            goto early_release;
        }
 
        res = ast_odbc_execute_sql(obj, stmt, ast_str_buffer(sql));
        if (!SQL_SUCCEEDED(res)) {
            ast_log(LOG_WARNING, "Insert failed on '%s:%s'.  CEL failed: %s\n", tableptr->connection, tableptr->table, ast_str_buffer(sql));
        }
 
        SQLFreeHandle(SQL_HANDLE_STMT, stmt);
 
early_release:
        ast_odbc_release_obj(obj);
    }
    AST_RWLIST_UNLOCK(&odbc_tables);
 
    /* 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_free(sql);
    ast_free(sql2);
}
 
static int unload_module(void)
{
    if (AST_RWLIST_WRLOCK(&odbc_tables)) {
        ast_log(LOG_ERROR, "Unable to lock column list.  Unload failed.\n");
        return -1;
    }
 
    ast_cel_backend_unregister(ODBC_BACKEND_NAME);
    free_config();
    AST_RWLIST_UNLOCK(&odbc_tables);
    AST_RWLIST_HEAD_DESTROY(&odbc_tables);
 
    return 0;
}
 
static int load_module(void)
{
    AST_RWLIST_HEAD_INIT(&odbc_tables);
 
    if (AST_RWLIST_WRLOCK(&odbc_tables)) {
        ast_log(LOG_ERROR, "Unable to lock column list.  Load failed.\n");
        return AST_MODULE_LOAD_DECLINE;
    }
    load_config();
    AST_RWLIST_UNLOCK(&odbc_tables);
    if (ast_cel_backend_register(ODBC_BACKEND_NAME, odbc_log)) {
        ast_log(LOG_ERROR, "Unable to subscribe to CEL events\n");
        free_config();
        return AST_MODULE_LOAD_DECLINE;
    }
    return AST_MODULE_LOAD_SUCCESS;
}
 
static int reload(void)
{
    if (AST_RWLIST_WRLOCK(&odbc_tables)) {
        ast_log(LOG_ERROR, "Unable to lock column list.  Reload failed.\n");
        return AST_MODULE_LOAD_DECLINE;
    }
 
    free_config();
    load_config();
    AST_RWLIST_UNLOCK(&odbc_tables);
    return AST_MODULE_LOAD_SUCCESS;
}
 
AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "ODBC CEL backend",
    .support_level = AST_MODULE_SUPPORT_CORE,
    .load = load_module,
    .unload = unload_module,
    .reload = reload,
    .load_pri = AST_MODPRI_CDR_DRIVER,
    .requires = "cel,res_odbc",
);