Set cURL as default in HTTP fetching, a fallback method and consistency fixup between both methods

1 files changed, 150 insertions, 10 deletions

diff --git a/application/HttpUtils.php b/application/HttpUtils.php
index 2e0792f9..27a39d3d 100644
--- a/application/HttpUtils.php
+++ b/application/HttpUtils.php
@@ -1,6 +1,7 @@
 <?php
 /**
  * GET an HTTP URL to retrieve its content
+ * Uses the cURL library or a fallback method 
  *
  * @param string $url      URL to get (http://...)
  * @param int    $timeout  network timeout (in seconds)
@@ -20,38 +21,177 @@
  *      echo 'There was an error: '.htmlspecialchars($headers[0]);
  *  }
  *
- * @see http://php.net/manual/en/function.file-get-contents.php
- * @see http://php.net/manual/en/function.stream-context-create.php
- * @see http://php.net/manual/en/function.get-headers.php
+ * @see https://secure.php.net/manual/en/ref.curl.php
+ * @see https://secure.php.net/manual/en/functions.anonymous.php
+ * @see https://secure.php.net/manual/en/function.preg-split.php
+ * @see https://secure.php.net/manual/en/function.explode.php
+ * @see http://stackoverflow.com/q/17641073
+ * @see http://stackoverflow.com/q/9183178
+ * @see http://stackoverflow.com/q/1462720
  */
 function get_http_response($url, $timeout = 30, $maxBytes = 4194304)
 {
     $urlObj = new Url($url);
     $cleanUrl = $urlObj->idnToAscii();
 
-    if (! filter_var($cleanUrl, FILTER_VALIDATE_URL) || ! $urlObj->isHttp()) {
+    if (!filter_var($cleanUrl, FILTER_VALIDATE_URL) || !$urlObj->isHttp()) {
         return array(array(0 => 'Invalid HTTP Url'), false);
     }
 
+    $userAgent =
+        'Mozilla/5.0 (X11; Fedora; Linux x86_64; rv:45.0)'
+        . ' Gecko/20100101 Firefox/45.0';
+    $acceptLanguage =
+        substr(setlocale(LC_COLLATE, 0), 0, 2) . ',en-US;q=0.7,en;q=0.3';
+    $maxRedirs = 3;
+
+    if (!function_exists('curl_init')) {
+        return get_http_response_fallback(
+            $cleanUrl,
+            $timeout,
+            $maxBytes,
+            $userAgent,
+            $acceptLanguage,
+            $maxRedirs
+        );
+    }
+
+    $ch = curl_init($cleanUrl);
+    if ($ch === false) {
+        return array(array(0 => 'curl_init() error'), false);
+    }
+
+    // General cURL settings
+    curl_setopt($ch, CURLOPT_AUTOREFERER,       true);
+    curl_setopt($ch, CURLOPT_FOLLOWLOCATION,    true);
+    curl_setopt($ch, CURLOPT_HEADER,            true);
+    curl_setopt(
+        $ch,
+        CURLOPT_HTTPHEADER,
+        array('Accept-Language: ' . $acceptLanguage)
+    );
+    curl_setopt($ch, CURLOPT_MAXREDIRS,         $maxRedirs);
+    curl_setopt($ch, CURLOPT_RETURNTRANSFER,    true);
+    curl_setopt($ch, CURLOPT_TIMEOUT,           $timeout);
+    curl_setopt($ch, CURLOPT_USERAGENT,         $userAgent);
+
+    // Max download size management
+    curl_setopt($ch, CURLOPT_BUFFERSIZE,        1024);
+    curl_setopt($ch, CURLOPT_NOPROGRESS,        false);
+    curl_setopt($ch, CURLOPT_PROGRESSFUNCTION,
+        function($arg0, $arg1, $arg2, $arg3, $arg4 = 0) use ($maxBytes)
+        {
+            if (version_compare(phpversion(), '5.5', '<')) {
+                // PHP version lower than 5.5
+                // Callback has 4 arguments
+                $downloaded = $arg1;
+            } else {
+                // Callback has 5 arguments
+                $downloaded = $arg2;
+            }
+            // Non-zero return stops downloading
+            return ($downloaded > $maxBytes) ? 1 : 0;
+        }
+    );
+
+    $response = curl_exec($ch);
+    $errorNo = curl_errno($ch);
+    $errorStr = curl_error($ch);
+    $headSize = curl_getinfo($ch, CURLINFO_HEADER_SIZE);
+    curl_close($ch);
+
+    if ($response === false) {
+        if ($errorNo == CURLE_COULDNT_RESOLVE_HOST) {
+            /*
+             * Workaround to match fallback method behaviour
+             * Removing this would require updating
+             * GetHttpUrlTest::testGetInvalidRemoteUrl()
+             */
+            return array(false, false);
+        }
+        return array(array(0 => 'curl_exec() error: ' . $errorStr), false);
+    }
+
+    // Formatting output like the fallback method
+    $rawHeaders = substr($response, 0, $headSize);
+
+    // Keep only headers from latest redirection
+    $rawHeadersArrayRedirs = explode("\r\n\r\n", trim($rawHeaders));
+    $rawHeadersLastRedir = end($rawHeadersArrayRedirs);
+
+    $content = substr($response, $headSize);
+    $headers = array();
+    foreach (preg_split('~[\r\n]+~', $rawHeadersLastRedir) as $line) {
+        if (empty($line) or ctype_space($line)) {
+            continue;
+        }
+        $splitLine = explode(': ', $line, 2);
+        if (count($splitLine) > 1) {
+            $key = $splitLine[0];
+            $value = $splitLine[1];
+            if (array_key_exists($key, $headers)) {
+                if (!is_array($headers[$key])) {
+                    $headers[$key] = array(0 => $headers[$key]);
+                }
+                $headers[$key][] = $value;
+            } else {
+                $headers[$key] = $value;
+            }
+        } else {
+            $headers[] = $splitLine[0];
+        }
+    }
+
+    return array($headers, $content);
+}
+
+/**
+ * GET an HTTP URL to retrieve its content (fallback method)
+ *
+ * @param string $cleanUrl       URL to get (http://... valid and in ASCII form)
+ * @param int    $timeout        network timeout (in seconds)
+ * @param int    $maxBytes       maximum downloaded bytes
+ * @param string $userAgent      "User-Agent" header
+ * @param string $acceptLanguage "Accept-Language" header
+ * @param int    $maxRedr        maximum amount of redirections followed
+ *
+ * @return array HTTP response headers, downloaded content
+ *
+ * Output format:
+ *  [0] = associative array containing HTTP response headers
+ *  [1] = URL content (downloaded data)
+ *
+ * @see http://php.net/manual/en/function.file-get-contents.php
+ * @see http://php.net/manual/en/function.stream-context-create.php
+ * @see http://php.net/manual/en/function.get-headers.php
+ */
+function get_http_response_fallback(
+    $cleanUrl,
+    $timeout,
+    $maxBytes,
+    $userAgent,
+    $acceptLanguage,
+    $maxRedr
+) {
     $options = array(
         'http' => array(
             'method' => 'GET',
             'timeout' => $timeout,
-            'user_agent' => 'Mozilla/5.0 (X11; Fedora; Linux x86_64; rv:45.0)'
-                         .' Gecko/20100101 Firefox/45.0',
-            'accept_language' => substr(setlocale(LC_COLLATE, 0), 0, 2) . ',en-US;q=0.7,en;q=0.3',
+            'user_agent' => $userAgent,
+            'header' => "Accept: */*\r\n"
+                . 'Accept-Language: ' . $acceptLanguage
         )
     );
 
     stream_context_set_default($options);
-    list($headers, $finalUrl) = get_redirected_headers($cleanUrl);
+    list($headers, $finalUrl) = get_redirected_headers($cleanUrl, $maxRedr);
     if (! $headers || strpos($headers[0], '200 OK') === false) {
         $options['http']['request_fulluri'] = true;
         stream_context_set_default($options);
-        list($headers, $finalUrl) = get_redirected_headers($cleanUrl);
+        list($headers, $finalUrl) = get_redirected_headers($cleanUrl, $maxRedr);
     }
 
-    if (! $headers || strpos($headers[0], '200 OK') === false) {
+    if (! $headers) {
         return array($headers, false);
     }