5 files changed, 274 insertions, 2 deletions
diff --git a/phpBB/download/file.php b/phpBB/download/file.php
index 891352f00c..68a4afe03c 100644
--- a/phpBB/download/file.php
+++ b/phpBB/download/file.php
@@ -246,7 +246,7 @@ if (!download_allowed())
 $download_mode = (int) $extensions[$attachment['extension']]['download_mode'];
 
 // Fetching filename here to prevent sniffing of filename
-$sql = 'SELECT attach_id, is_orphan, in_message, post_msg_id, extension, physical_filename, real_filename, mimetype, filetime
+$sql = 'SELECT attach_id, is_orphan, in_message, post_msg_id, extension, physical_filename, real_filename, mimetype, filesize, filetime
 	FROM ' . ATTACHMENTS_TABLE . "
 	WHERE attach_id = $download_id";
 $result = $db->sql_query_limit($sql, 1);
@@ -275,7 +275,7 @@ if ($thumbnail)
 {
 	$attachment['physical_filename'] = 'thumb_' . $attachment['physical_filename'];
 }
-else if (($display_cat == ATTACHMENT_CATEGORY_NONE/* || $display_cat == ATTACHMENT_CATEGORY_IMAGE*/) && !$attachment['is_orphan'])
+else if (($display_cat == ATTACHMENT_CATEGORY_NONE/* || $display_cat == ATTACHMENT_CATEGORY_IMAGE*/) && !$attachment['is_orphan'] && !phpbb_http_byte_range($attachment['filesize']))
 {
 	// Update download count
 	$sql = 'UPDATE ' . ATTACHMENTS_TABLE . '
diff --git a/phpBB/includes/functions_download.php b/phpBB/includes/functions_download.php
index 87bf7a91a6..94d851e383 100644
--- a/phpBB/includes/functions_download.php
+++ b/phpBB/includes/functions_download.php
@@ -157,6 +157,16 @@ function send_file_to_browser($attachment, $upload_dir, $category)
 		trigger_error('UNABLE_TO_DELIVER_FILE');
 	}
 
+	// Make sure the database record for the filesize is correct
+	if ($size > 0 && $size != $attachment['filesize'])
+	{
+		// Update database record
+		$sql = 'UPDATE ' . ATTACHMENTS_TABLE . '
+			SET filesize = ' . (int) $size . '
+			WHERE attach_id = ' . (int) $attachment['attach_id'];
+		$db->sql_query($sql);
+	}
+
 	// Now the tricky part... let's dance
 	header('Pragma: public');
 
@@ -226,6 +236,16 @@ function send_file_to_browser($attachment, $upload_dir, $category)
 
 		if ($fp !== false)
 		{
+			// Deliver file partially if requested
+			if ($range = phpbb_http_byte_range($size))
+			{
+				fseek($fp, $range['byte_pos_start']);
+
+				send_status_line(206, 'Partial Content');
+				header('Content-Range: bytes ' . $range['byte_pos_start'] . '-' . $range['byte_pos_end'] . '/' . $range['bytes_total']);
+				header('Content-Length: ' . $range['bytes_requested']);
+			}
+
 			while (!feof($fp))
 			{
 				echo fread($fp, 8192);
@@ -407,3 +427,151 @@ function file_gc()
 	$db->sql_close();
 	exit;
 }
+
+/**
+* HTTP range support (RFC 2616 Section 14.35)
+*
+* Allows browsers to request partial file content
+* in case a download has been interrupted.
+*
+* @param int $filesize		the size of the file in bytes we are about to deliver
+*
+* @return mixed		false if the whole file has to be delivered
+*					associative array on success
+*/
+function phpbb_http_byte_range($filesize)
+{
+	// Only call find_range_request() once.
+	static $request_array;
+
+	if (!$filesize)
+	{
+		return false;
+	}
+
+	if (!isset($request_array))
+	{
+		$request_array = phpbb_find_range_request();
+	}
+	
+	return (empty($request_array)) ? false : phpbb_parse_range_request($request_array, $filesize);
+}
+
+/**
+* Searches for HTTP range request in super globals.
+*
+* @return mixed		false if no request found
+*					array of strings containing the requested ranges otherwise
+*					e.g. array(0 => '0-0', 1 => '123-125')
+*/
+function phpbb_find_range_request()
+{
+	$globals = array(
+		array('_SERVER',	'HTTP_RANGE'),
+		array('_ENV',		'HTTP_RANGE'),
+	);
+
+	foreach ($globals as $array)
+	{
+		$global	= $array[0];
+		$key	= $array[1];
+
+		// Make sure range request starts with "bytes="
+		if (isset($GLOBALS[$global][$key]) && strpos($GLOBALS[$global][$key], 'bytes=') === 0)
+		{
+			// Strip leading 'bytes='
+			// Multiple ranges can be separated by a comma
+			return explode(',', substr($GLOBALS[$global][$key], 6));
+		}
+	}
+
+	return false;
+}
+
+/**
+* Analyses a range request array.
+*
+* A range request can contain multiple ranges,
+* we however only handle the first request and
+* only support requests from a given byte to the end of the file.
+*
+* @param array	$request_array	array of strings containing the requested ranges
+* @param int	$filesize		the full size of the file in bytes that has been requested
+*
+* @return mixed		false if the whole file has to be delivered
+*					associative array on success
+*						byte_pos_start		the first byte position, can be passed to fseek()
+*						byte_pos_end		the last byte position
+*						bytes_requested		the number of bytes requested
+*						bytes_total			the full size of the file
+*/
+function phpbb_parse_range_request($request_array, $filesize)
+{
+	// Go through all ranges
+	foreach ($request_array as $range_string)
+	{
+		$range = explode('-', trim($range_string));
+
+		// "-" is invalid, "0-0" however is valid and means the very first byte.
+		if (sizeof($range) != 2 || $range[0] === '' && $range[1] === '')
+		{
+			continue;
+		}
+
+		if ($range[0] === '')
+		{
+			// Return last $range[1] bytes.
+
+			if (!$range[1])
+			{
+				continue;
+			}
+
+			if ($range[1] >= $filesize)
+			{
+				return false;
+			}
+
+			$first_byte_pos	= $filesize - (int) $range[1];
+			$last_byte_pos	= $filesize - 1;
+		}
+		else
+		{
+			// Return bytes from $range[0] to $range[1]
+
+			$first_byte_pos	= (int) $range[0];
+			$last_byte_pos	= (int) $range[1];
+
+			if ($last_byte_pos && $last_byte_pos < $first_byte_pos)
+			{
+				// The requested range contains 0 bytes.
+				continue;
+			}
+
+			if ($first_byte_pos >= $filesize)
+			{
+				// Requested range not satisfiable
+				return false;
+			}
+
+			// Adjust last-byte-pos if it is absent or greater than the content.
+			if ($range[1] === '' || $last_byte_pos >= $filesize)
+			{
+				$last_byte_pos = $filesize - 1;
+			}
+		}
+
+		// We currently do not support range requests that end before the end of the file
+		if ($last_byte_pos != $filesize - 1)
+		{
+			continue;
+		}
+
+		return array(
+			'byte_pos_start'	=> $first_byte_pos,
+			'byte_pos_end'		=> $last_byte_pos,
+			'bytes_requested'	=> $last_byte_pos - $first_byte_pos + 1,
+			'bytes_total'		=> $filesize,
+		);
+	}
+}
diff --git a/tests/all_tests.php b/tests/all_tests.php
index feaaa1f0a1..4c2fa891a2 100644
--- a/tests/all_tests.php
+++ b/tests/all_tests.php
@@ -26,6 +26,7 @@ require_once 'dbal/all_tests.php';
 require_once 'regex/all_tests.php';
 require_once 'network/all_tests.php';
 require_once 'random/all_tests.php';
+require_once 'download/all_tests.php';
 
 // exclude the test directory from code coverage reports
 if (version_compare(PHPUnit_Runner_Version::id(), '3.5.0') >= 0)
@@ -59,6 +60,7 @@ class phpbb_all_tests
 		$suite->addTest(phpbb_regex_all_tests::suite());
 		$suite->addTest(phpbb_network_all_tests::suite());
 		$suite->addTest(phpbb_random_all_tests::suite());
+		$suite->addTest(phpbb_download_all_tests::suite());
 
 		return $suite;
 	}
diff --git a/tests/download/all_tests.php b/tests/download/all_tests.php
new file mode 100644
index 0000000000..21305a887c
--- /dev/null
+++ b/tests/download/all_tests.php
@@ -0,0 +1,40 @@
+<?php
+/**
+*
+* @package testing
+* @copyright (c) 2010 phpBB Group
+* @license http://opensource.org/licenses/gpl-license.php GNU Public License
+*
+*/
+
+if (!defined('PHPUnit_MAIN_METHOD'))
+{
+	define('PHPUnit_MAIN_METHOD', 'phpbb_download_all_tests::main');
+}
+
+require_once 'test_framework/framework.php';
+require_once 'PHPUnit/TextUI/TestRunner.php';
+
+require_once 'download/http_byte_range.php';
+
+class phpbb_download_all_tests
+{
+	public static function main()
+	{
+		PHPUnit_TextUI_TestRunner::run(self::suite());
+	}
+
+	public static function suite()
+	{
+		$suite = new PHPUnit_Framework_TestSuite('phpBB Download Tests');
+
+		$suite->addTestSuite('phpbb_download_http_byte_range_test');
+
+		return $suite;
+	}
+}
+
+if (PHPUnit_MAIN_METHOD == 'phpbb_download_all_tests::main')
+{
+	phpbb_regex_all_tests::main();
+}
diff --git a/tests/download/http_byte_range.php b/tests/download/http_byte_range.php
new file mode 100644
index 0000000000..cc42dee353
--- /dev/null
+++ b/tests/download/http_byte_range.php
@@ -0,0 +1,62 @@
+<?php
+/**
+*
+* @package testing
+* @copyright (c) 2010 phpBB Group
+* @license http://opensource.org/licenses/gpl-license.php GNU Public License
+*
+*/
+
+require_once 'test_framework/framework.php';
+require_once '../phpBB/includes/functions_download.php';
+
+class phpbb_download_http_byte_range_test extends phpbb_test_case
+{
+	public function test_find_range_request()
+	{
+		// Missing 'bytes=' prefix
+		$_SERVER['HTTP_RANGE'] = 'bztes=';
+		$this->assertEquals(false, phpbb_find_range_request());
+		unset($_SERVER['HTTP_RANGE']);
+
+		$_ENV['HTTP_RANGE'] = 'bztes=';
+		$this->assertEquals(false, phpbb_find_range_request());
+		unset($_ENV['HTTP_RANGE']);
+
+		$_SERVER['HTTP_RANGE'] = 'bytes=0-0,123-125';
+		$this->assertEquals(array('0-0', '123-125'), phpbb_find_range_request());
+		unset($_SERVER['HTTP_RANGE']);
+	}
+
+	/**
+	* @dataProvider parse_range_request_data()
+	*/
+	public function test_parse_range_request($request_array, $filesize, $expected)
+	{
+		$this->assertEquals($expected, phpbb_parse_range_request($request_array, $filesize));
+	}
+
+	public function parse_range_request_data()
+	{
+		return array(
+			// Does not read until the end of file.
+			array(
+				array('3-4'),
+				10,
+				false,
+			),
+
+			// Valid request, handle second range.
+			array(
+				array('0-0', '120-125'),
+				125,
+				array(
+					'byte_pos_start'	=> 120,
+					'byte_pos_end'		=> 124,
+					'bytes_requested'	=> 5,
+					'bytes_total'		=> 125,
+				)
+			),
+		);
+	}
+}