From 77f9c55e858fa9739880c5aa0ffff0dd11b6a4c7 Mon Sep 17 00:00:00 2001
From: Kenji ITO <mystralkk@gmail.com>
Date: Mon, 23 Jan 2017 21:02:02 +0900
Subject: [PATCH] Add user agent to 404.log entry (code provided by hiroron)

---
 public_html/lib-common.php | 49 +++++++++++++++++++++++++-------------
 1 file changed, 33 insertions(+), 16 deletions(-)

diff --git a/public_html/lib-common.php b/public_html/lib-common.php
index 806458402..afe10d4a2 100644
--- a/public_html/lib-common.php
+++ b/public_html/lib-common.php
@@ -7658,36 +7658,53 @@ function COM_handle404($alternate_url = '')
     header('HTTP/1.1 404 Not Found');
     header('Status: 404 Not Found');
 
-    // Add log stuff
-    $url = COM_getCurrentURL();
-    if (isset($_USER['uid'])) {
-        $byUser = $_USER['uid'] . '@' . $_SERVER['REMOTE_ADDR'];
+    if (isset($_SERVER['SCRIPT_URI'])) {
+        $url = $_SERVER['SCRIPT_URI'];
     } else {
+        if (empty($_SERVER['HTTPS']) || ($_SERVER['HTTPS'] === 'off')) {
+            $url = 'http';
+        } else {
+            $url = 'https';
+        }
+
+        $url .= '://' . @$_SERVER['HTTP_HOST'] . strip_tags($_SERVER['SCRIPT_URI']);
+    }
+
+    // Add log stuff
+    if (empty($_USER['uid'])) {
         $byUser = 'anon@' . $_SERVER['REMOTE_ADDR'];
+    } else {
+        $byUser = $_USER['uid'] . '@' . $_SERVER['REMOTE_ADDR'];
     }
-    $refUrl = $_SERVER['HTTP_REFERER'];
-    $timestamp = @strftime('%c');
-    $logEntry = "404 Error generated by $byUser for url: $url";
-    if (!empty($refUrl)) {
-        $logEntry .= " - Referring url: $refUrl";
+
+    $logEntry = "404 Error generated by {$byUser} for URL: {$url}";
+
+    // Add referer
+    if (!empty($_SERVER['HTTP_REFERER'])) {
+        $logEntry .= " - Referring URL: {$_SERVER['HTTP_REFERER']}";
     }
-    $logEntry = str_replace(array('<?', '?>'), array('(@', '@)'), $logEntry);
 
-    $logfile = $_CONF['path_log'] . '404.log';
-    if ($file = fopen($logfile, 'a')) {
-        fputs($file, "$timestamp - $logEntry \n");
+    // Add user agent
+    if (isset($_SERVER['HTTP_USER_AGENT'])) {
+        $logEntry .= ' - User agent: ' . $_SERVER['HTTP_USER_AGENT'];
     }
 
-    $display = COM_startBlock($LANG_404[1]);
-    $display .= sprintf($LANG_404[2], $url);
+    // Write into log file
+    $logEntry = str_replace(array('<?', '?>'), array('(@', '@)'), $logEntry);
+    $logEntry = @strftime('%c') . ' - ' . $logEntry . PHP_EOL;
+    @file_put_contents($_CONF['path_log'] . '404.log', $logEntry, FILE_APPEND | LOCK_EX);
+
+    $display = COM_startBlock($LANG_404[1])
+        . sprintf($LANG_404[2], $url);
+
     if ($alternate_url != '') {
         $display .= sprintf($LANG_404[4], $alternate_url);
     } else {
         $display .= $LANG_404[3];
     }
+
     $display .= COM_endBlock();
     $display = COM_createHTMLDocument($display, array('pagetitle' => $LANG_404[1]));
-
     COM_output($display);
     exit; // Do not want to go any further
 }