<?php

/*
 * MailWatch for MailScanner
 * Copyright (C) 2003-2011  Steve Freegard (steve@freegard.name)
 * Copyright (C) 2011  Garrod Alwood (garrod.alwood@lorodoes.com)
 * Copyright (C) 2014-2021  MailWatch Team (https://github.com/mailwatch/1.2.0/graphs/contributors)
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
 *
 * In addition, as a special exception, the copyright holder gives permission to link the code of this program with
 * those files in the PEAR library that are licensed under the PHP License (or with modified versions of those files
 * that use the same license as those files), and distribute linked combinations including the two.
 * You must obey the GNU General Public License in all respects for all of the code used other than those files in the
 * PEAR library that are licensed under the PHP License. If you modify this program, you may extend this exception to
 * your version of the program, but you are not obligated to do so.
 * If you do not wish to do so, delete this exception statement from your version.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

ini_set('error_log', 'syslog');
ini_set('html_errors', 'off');
ini_set('display_errors', 'on');
ini_set('implicit_flush', 'false');

// Edit if you changed webapp directory from default
$pathToFunctions = '/var/www/html/mailscanner/functions.php';
if (!@is_file($pathToFunctions)) {
    exit('Error: Cannot find functions.php file in "' . $pathToFunctions . '": edit ' . __FILE__ . ' and set the right path on line ' . (__LINE__ - 3) . PHP_EOL);
}
require $pathToFunctions;

// Set-up environment
set_time_limit(0);
// Limit to how long a queue id remains in queue before dropping
define('QUEUETIMEOUT', '300');
define('DEBUG_MILTER', false);

$idqueue = [];

function doit($input)
{
    if (!$fp = popen($input, 'r')) {
        exit(__('diepipe54'));
    }

    while ($line = fgets($fp, 2096)) {
        process_entries($line);
    }

    process_sql();

    pclose($fp);
}

function follow($file)
{
    $size = filesize($file);
    while (true) {
        clearstatcache();
        $currentSize = filesize($file);
        if ($size == $currentSize) {
            sleep(5);
            continue;
        }

        $fh = fopen($file, 'r');
        if (!$fh) {
            exit(__('diepipe56'));
        }
        fseek($fh, $size);

        while ($line = fgets($fh)) {
            process_entries($line);
        }

        process_sql();

        fclose($fh);
        $size = $currentSize;
    }
}

/* Loop through log, looking for message-ids and matching to addresses
 * Populates $idqueue 2 dimensional array,
 * first element is entry for a queue id
 * second element are properties of the entry
 * [0] -- queue id
 * [1] -- message-id
 * [2] -- timestamp in epoch
 * [3] -- delivery attempt (to address)
 */
function process_entries($line)
{
    global $idqueue;

    // Watch for message-id's
    if (preg_match('/^.*postfix\/cleanup.*: (\S+): message-id=(\S+)$/', $line, $explode)) {
        // Add to queue and timestamp it
        $arrEntry = [];
        array_push($arrEntry, $explode[1]);
        array_push($arrEntry, $explode[2]);
        array_push($arrEntry, time());
        array_push($arrEntry, null);
        array_push($idqueue, $arrEntry);
        if (DEBUG_MILTER === true) {
            syslog(LOG_MAIL | LOG_DEBUG, 'milter_relay: Added smtpid ' . $explode[1] . ' to relay queue');
        }

        // Watch for verifications
    } elseif (preg_match('/^.*postfix\/smtp.*: (\S+):.*status=(?:deliverable|undeliverable)/', $line, $id)) {
        remove_entry($id[1]);
        if (DEBUG_MILTER === true) {
            syslog(LOG_MAIL | LOG_DEBUG, 'milter_relay: Removed smtpid ' . $id[1] . ' from relay queue (delivery verification)');
        }

        // Watch for milter connections
    } elseif (preg_match('/^.*postfix\/cleanup.*: (\S+): milter/', $line, $id)) {
        remove_entry($id[1]);
        if (DEBUG_MILTER === true) {
            syslog(LOG_MAIL | LOG_DEBUG, 'milter_relay: Removed smtpid ' . $id[1] . ' from relay queue (milter activity)');
        }
        // Watch for deliver attempts (after verification check above)
    } elseif (preg_match('/^.*postfix\/smtp.*: (\S+): to=\<(\S+)\>,/', $line, $explode)) {
        // Scan queue for matching id
        $idcount = count($idqueue);
        for ($i = 0; $i < $idcount; ++$i) {
            if ($idqueue[$i][0] === $explode[1]) {
                // Delivery attempt found
                $idqueue[$i][3] = $explode[2];
                if (DEBUG_MILTER === true) {
                    syslog(LOG_MAIL | LOG_DEBUG, 'milter_relay: delivery attempt for smtpid ' . $explode[1] . ' detected and updated in queue');
                }
                break;
            }
        }
    }
}

function process_sql()
{
    global $idqueue;

    // Scan queue for delivery attempts in queue and matching maillog entries
    $idcount = count($idqueue);
    for ($i = 0; $i < $idcount; ++$i) {
        if (null !== $idqueue[$i][3]) {
            $message_id = safe_value($idqueue[$i][1]);
            $to = safe_value($idqueue[$i][3]);
            $smtp_id = safe_value($idqueue[$i][0]);

            $result = dbquery("SELECT id from `maillog` where messageid='" . $message_id . "' and to_address LIKE '%" . $to . "%' LIMIT 1;");
            @$smtpd_id = $result->fetch_row()[0];

            if (DEBUG_MILTER === true) {
                syslog(LOG_MAIL | LOG_DEBUG, 'milter_relay: idqueue ' . $i . ' of ' . ($idcount - 1) . ' / ' . $smtp_id . ' / ' . $message_id . ' / ' . $to . ' => ' . $smtpd_id);
            }

            // Find correllating ids and update table, drop from queue
            if (isset($smtpd_id) && $smtpd_id !== $smtp_id) {
                dbquery("REPLACE INTO `mtalog_ids` VALUES ('" . $smtpd_id . "','" . $smtp_id . "')");
                array_splice($idqueue, $i, 1);
                --$i;
                $idcount = count($idqueue);
                if (DEBUG_MILTER === true) {
                    syslog(LOG_MAIL | LOG_DEBUG, 'milter_relay: maillog hit for ' . $smtp_id . ' entry logged and removed from queue');
                }
            }
        }
    }
}

function remove_entry($id)
{
    global $idqueue;

    // Search queue for id
    $idcount = count($idqueue);
    for ($i = 0; $i < $idcount; ++$i) {
        if (time() > $idqueue[$i][2] + QUEUETIMEOUT) {
            // Drop expired entry from queue
            if (DEBUG_MILTER === true) {
                syslog(LOG_MAIL | LOG_DEBUG, 'milter_relay: Expiring smtpid ' . $idqueue[$i][0] . ' after ' . QUEUETIMEOUT . ' seconds');
            }
            array_splice($idqueue, $i, 1);
            --$i;
            $idcount = count($idqueue);
            continue;
        }

        if ($idqueue[$i][0] === $id) {
            // Drop id from array
            array_splice($idqueue, $i, 1);
            break;
        }
    }
}

if (isset($_SERVER['argv'][1]) && '--refresh' === $_SERVER['argv'][1]) {
    doit('cat ' . MS_LOG);
} else {
    // Refresh first
    doit('cat ' . MS_LOG);
    // Start watching the maillog
    follow(MS_LOG);
}