Created
June 7, 2009 12:30
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a quick and dirty fallback downloader and load balancer
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################ | |
# INSTALLATION # | |
################ | |
There should be no weird php.ini variables to set, so just move this to a server and set the appropriate permissions. | |
If you want to make it so a URL can be parsed as http://foo.bar/proxy/param1/param2/paramn, you can utilise a .htaccess | |
file to do this. | |
First, rename proxy.php to proxy and then put a .htaccess file in the same directory as proxy with the following information: | |
<Files proxy> | |
ForceType application/x-httpd-php | |
</Files> | |
This will force apache to handle any requests to proxy with a content-type of application/x-httpd-php, forcing apache to execute it as | |
a php script. | |
######### | |
# USAGE # | |
######### | |
To use this in darkplaces/nexuiz, the following is a sample example curl_urls.txt that was used as a base case: | |
teambubble-colours.pk3 http://pavlvs.nexuizninjaz.com/servrarz/models/ | |
robot_v2.pk3 http://pavlvs.nexuizninjaz.com/servrarz/models/ | |
nxmdls-fel-jag-lei-sui.pk3 http://pavlvs.nexuizninjaz.com/servrarz/models/ | |
nxmdl-abyss.pk3 http://pavlvs.nexuizninjaz.com/servrarz/models/ | |
nxmdl-oa_angelyss_md3_tagfixed.pk3 http://pavlvs.nexuizninjaz.com/servrarz/models/ | |
nxmdl-spy.pk3 http://pavlvs.nexuizninjaz.com/servrarz/models/ | |
zuriastrad-bot.pk3 http://pavlvs.nexuizninjaz.com/servrarz/models/ | |
zz-keyhuntfix080813.pk3 http://pavlvs.nexuizninjaz.com/servrarz/models/ | |
zz-genderfix080817.pk3 http://pavlvs.nexuizninjaz.com/servrarz/models/ | |
nexball-ballmodel.pk3 http://pavlvs.nexuizninjaz.com/servrarz/models/ | |
spidflisk_effectinfo_* http://pavlvs.nexuizninjaz.com/servrarz/models/ | |
* http://lixi.nexfiles.com/proxy.php/map/ | |
This allows a user to specify finer granularity for static files, and use the proxy as a fallback. The idea | |
is that explicit file definitions should be guaranteed to at least not 404; though I'd like to allow proxy.cfg to be able | |
to load balance and fallback explicit files (per-file sets of providers). See CONFIG for where I want to take this. | |
In generic terms, the URL request takes this form: | |
http://foo.bar/proxy.php/key1/value1/key2/value2/keyn/valuen | |
And the four understood keys thus far are: | |
string "map" (defaults to null) | |
boolean "load_balance" (defaults to true, if it's set to anything, it's false) | |
int "retries" (not yet used; will default to 0) | |
boolean "debug" (*DO NOT USE* this for direct downloads; only use this to test the script from a direct request in the browser) | |
So an example might be: | |
http://maps.somedomain.ext/proxy.php/retries/2/load_balance/false/map/test.pk3 | |
or | |
http://maps.somedomain.ext/proxy.php/retries/2/map/test.pk3/debug/true | |
Please note that for darkplaces "map" has to be the last parameter, because the map's filename is automatically appended to request URL before | |
being dispatched. Other game servers might have different requirements on this; please check the server's documentation for clarification on this. | |
########## | |
# CONFIG # | |
########## | |
By default, the script expects a config file of config.cfg to reside in the same directory as the proxy script. However, this can be configured | |
by means of editing the proxy.php file and editing: | |
define("INI_FILE", "proxy.cfg"); | |
to be a relative or absolute path to your config file. | |
The config file uses a standard Windows or PHP ini structure, for example: | |
[section 1] | |
parameter1 = "value"; | |
parameter2 = "value2"; | |
[section 2] | |
parameter3 = "value3"; | |
parameter4 = "value4"; | |
The sample proxy.cfg has two example URLs in it, to define multiple values for one key, a [] must be used in the key name. For example: | |
[filename.pk3] | |
urls[] = "http://www.google.com"; | |
urls[] = "http://www.microsoft.com"; | |
urls[] = "http://www.apple.com"; | |
[filename2.pk3] | |
urls[] = "http://www.yahoo.com"; | |
urls[] = "http://www.opera.com"; | |
[filename3.pk3] | |
urls[] = "http://www.fark.com"; | |
urls[] = "http://news.google.com"; | |
The script doesn't currently support grouping (with [filenamen.blah]), but grouping these is something I want to do, so that multiple values | |
can be assigned on a per-file basis (and namespacing with inheritance, too). |
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urls[]="http://maps.nexuizninjaz.com/" | |
urls[]="http://maps.nexfiles.com/" | |
urls[]="http://maps.nexfiles.com/spidflisk/" | |
urls[]="http://maps.praeclan.com/" | |
urls[]="http://maps.praeclan.com/spidflisk/" | |
urls[]="http://rm.endoftheinternet.org/~nexuiz/maps/" |
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<?php | |
/** | |
* proxy.php -- A simple little script to pseudo load balance/failover multiple map servers. | |
* by Lixivial (Jesse Pearson) | |
* contact: jesall@gmail.com | |
* or irc.quakenet.org/#prae.nexuiz | |
* URL parameter construct: | |
* | |
* http://foo.bar/install.path/debug/{true|false}/load_balance/{true|false}/retries/{n-maxn}/map/{filename} | |
* | |
* This will then be accessible in an associative array by the given key (load_balance, retries, map). | |
* param defaults are as follows: | |
* debug false | |
* load_balance true | |
* retries 0 | |
* map null | |
* | |
* 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 3 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. | |
* | |
* You should have received a copy of the GNU General Public License | |
* along with this program. If not, see <http://www.gnu.org/licenses/>. | |
*/ | |
define("INI_FILE", "proxy.cfg"); | |
define("MAX_PARAM_LENGTH", 254); | |
// The number used to accommodate pings that were unable to be retrieved, or local servers, | |
// to push them to the bottom of the load balanced sorted list. | |
define("ARTIFICIAL_PING", rand(125, 200)); | |
// You can use this variable to set a global redirection on error. | |
define("ERROR_REDIRECT_LOCATION", null); | |
// If debugging is enabled, this is the level of error reporting PHP will report. | |
// E_ALL ^ E_NOTICE is default PHP error reporting (all errors except notice). | |
define("ERROR_REPORTING_LEVEL", E_ALL ^ E_NOTICE); | |
/* If a user wants to use ICMP as a ping, set this to TRUE. | |
Note that it'll probably be less reliable to get data back from the server | |
as many people block these requests, but if this is set to true, it'll fallback | |
to using the method used when this is defined as FALSE. | |
Also, even though this is set to TRUE, there's no guarantee the web user will | |
have sufficient permissions to open a raw socket.*/ | |
define("USE_ICMP", FALSE); | |
define("MAX_ICMP_BYTES", 512); | |
$params = get_parameters(); | |
$config = parse_ini_file(INI_FILE); | |
/* If debugging is set on the URL, then allow the specified error reporting level, | |
otherwise silently eat all errors, so as not to offer a corrupted download | |
to a client. */ | |
error_reporting(isset($params['debug']) ? ERROR_REPORTING_LEVEL : 0); | |
// Perform pseudo load balancing? | |
$load_balance = isset($params['load_balance']) ? FALSE : TRUE; | |
// NOT YET USED: Perform a given number of retries on a host before moving on. | |
$retries = isset($params['retries']) ? $params['retries'] : 1; | |
// Construct our list of servers, and, if loadbalancing, then order them by their response times. | |
$servers = get_server_list($load_balance, $config["urls"]); | |
// Ensure that a map variable was given and that we have access to the curl extension. | |
if ((isset($params['map']) && $params['map'] != "") && extension_loaded('curl')) { | |
// Instantiate a null curl handle. | |
$chandle = curl_init(); | |
if (!isset($params['debug'])) { | |
$count = 0; | |
/* Since this is already sorted by lowest ping, we'll take them 1-by-1 | |
and take the first to give a valid response. | |
NOTE: This has to be done as close to the actual redirect such that we get the most accurate | |
representation of the actual server response (which is more important than pinging). */ | |
foreach($servers as $key => $value) { | |
$temp_url = $key.$params['map']; | |
$count++; | |
if (get_status_code($chandle, $temp_url) == 200) { | |
header("Location: ".$temp_url); | |
break; | |
} else if ($count + 1 >= count($servers)) { | |
die_404(); | |
} | |
} | |
} else { | |
if (PHP_SAPI == "cli") { | |
echo " Map | Server | Ping | Status |\r\n"; | |
foreach($servers as $key => $value) { | |
$temp_url = $key.$params['map']; | |
echo $params['map']." | ".$key." | ".$value." | ".get_status_code($chandle, $temp_url)."\r\n"; | |
} | |
} else { | |
echo "<table><tr><td>Map</td><td>Server</td><td>Ping</td><td>Status</td>"; | |
foreach($servers as $key => $value) { | |
$temp_url = $key.$params['map']; | |
echo "<tr><td>".$params['map']."</td><td>".$key."</td><td>".$value."</td><td>".get_status_code($chandle, $temp_url)."</td>"; | |
} | |
echo "</table>"; | |
} | |
} | |
// Close the curl handle. | |
curl_close($chandle); | |
} else { | |
die_404(); | |
} | |
exit; | |
/** | |
* Throw a 404 response so that any cURL or any file downloaders will get a standard error response. | |
* rather than a blank page or a page with a message, which will result in a 200. | |
* | |
* It can take an optional parameter to override the default static variable | |
* ERROR_REDIRECT_LOCATION, in case there are instances where we want to redirect | |
* requests for some reason. | |
* | |
* @param string $redirect | |
*/ | |
function die_404($redirect=null) { | |
if ($redirect != null) { | |
header("Location: ".$redirect); | |
} else if (ERROR_REDIRECT_LOCATION != null) { | |
header("Location: ".ERROR_REDIRECT_LOCATION); | |
} else { | |
header("HTTP/1.1 404 Not Found", true, 404); | |
header("Status: 404 Not Found", true, 404); | |
} | |
} | |
/** | |
* Tokenize the parameters in the form of /param1/paramn/ | |
* | |
* Parameters take this form, rather than param1=test¶mn=testn to accommodate | |
* crawler-safe URLs. | |
* | |
* The URL should take the form of http://foo.bar/key1/value1/key2/value2/keyn/valuen | |
* It makes the URL longer than, say, http://foo.bar/value1/value2/value3, but offers | |
* reliable access to values in other areas, without worrying about the order in which | |
* they were typed in the request. | |
* | |
* @return associative array $return_params | |
* Array of parameters. Note that this can be empty. | |
*/ | |
function get_parameters() { | |
if(isset($_SERVER['PATH_INFO'])) { | |
$return_params = array(); | |
// Split the URL on / | |
$params = explode('/', $_SERVER['PATH_INFO']); | |
array_shift($params); | |
reset($params); | |
// loop every other one (every even will be a key, every odd will be a value) | |
for ($i=0; $i<count($params); $i=$i+2) { | |
$key = $params[$i]; | |
$value = $params[$i + 1]; | |
// if it has a value, place it in the associative array with its key. | |
// Also prevent sending overly long value or keys. | |
if ((isset($value) && strlen($value) < MAX_PARAM_LENGTH) && strlen($key) < MAX_PARAM_LENGTH) { | |
$return_params[ $key ] = $value; | |
} | |
} | |
return $return_params; | |
} else { | |
die_404(); | |
} | |
} | |
/** | |
* Construct an associative array of sites and their pings. | |
* | |
* @param boolean $load_balance | |
* Whether or not to attempt rudimentary load balancing (via ping). | |
* @param array $server_list | |
* A list of servers, in the form of http://www.google.com or www.google.com. | |
* @return associative array $hash_table | |
* A sorted associative array whose value of ping is keyed by the server name. | |
*/ | |
function get_server_list($load_balance, $server_list) { | |
$hash_table = array(); | |
// Go over each of the server_list URLs in order to build an key/value pair out of them. | |
if (count($server_list) > 0) { | |
foreach($server_list as $server_url) { | |
if ($load_balance) { | |
/* Check to see if it's a local server. If it is, we're going to put it at the bottom of the list. | |
This is a stupid stupid stupid check, it should become more intelligent through some constructive | |
and clever querying. */ | |
if (strpos($server_url,$_SERVER['SERVER_NAME']) === false) { | |
$ping = ping(split_url($server_url)); | |
# Set the ping, if it's found, else place it at the end of the list. | |
if ($ping != null) { | |
$hash_table[ $server_url ] = $ping; | |
} else { | |
$hash_table[ $server_url ] = ARTIFICIAL_PING; | |
} | |
} else { | |
$hash_table[ $server_url ] = ARTIFICIAL_PING; | |
} | |
} else { | |
$hash_table[ $server_url ] = ARTIFICIAL_PING; | |
} | |
} | |
if ($load_balance) { | |
uasort($hash_table, "comparator"); | |
} | |
return $hash_table; | |
} else { | |
die_404(); | |
} | |
} | |
/** | |
* Checks a site's HTTP status. | |
* | |
* @param resource $handle | |
* A null or already init'd curl handle. | |
* @param string $url | |
* The URL to check, in the form of http://foo.bar.com/path/to/file.ext | |
* @return int | |
* The status as returned from the target web server (404, 503, 200, etc) | |
*/ | |
function get_status_code($handle, $url) { | |
// Ensure that we can actually perform the action... | |
if (!ini_get('safe_mode') && | |
(strpos(ini_get('disable_functions'), 'curl_exec') == 0) && | |
(strpos(ini_get('disable_functions'), 'curl_get_info') == 0) && | |
(strpos(ini_get('disable_functions'), 'curl_setopt_array') == 0)) { | |
/* Reset the URL, and ensure that the header and results are returned. | |
Also, limit our byte download to just 1 byte, so that we can get our status code without | |
having to download the file ourselves. */ | |
curl_setopt_array($handle, array(CURLOPT_URL => $url, | |
CURLOPT_RETURNTRANSFER=>TRUE, | |
CURLOPT_HEADER=>TRUE, | |
CURLOPT_RANGE=>"0-1")); | |
// Perform the connection in order to determine the server's response. | |
$response = curl_exec($handle); | |
// Return the status code. | |
$status = curl_getinfo($handle, CURLINFO_HTTP_CODE); | |
// Since we chopped off our download, we'll get a 206; force it to be a 200. | |
return $status == 206 ? 200 : $status; | |
} else { | |
return 404; | |
} | |
} | |
/** | |
* Pings a domain using ICMP, TCP or UDP. | |
* | |
* If USE_ICMP is defined as being TRUE, then it attempts to create a socket connection, which | |
* requires privilege escalation on most platforms. If this fails, it parses the output of the | |
* ping utility. If *that* fails, it falls back to a simple fsockopen() ping. | |
* | |
* @param associative array $url | |
* The array of the parsed requested URL. | |
* @return int $status | |
* The time it took fsockopen to respond between $starttime and $stoptime assignments. | |
*/ | |
function ping($url) { | |
if (USE_ICMP) { | |
// First ensure that the sockets extension has been loaded and compiled into PHP. | |
if(extension_loaded('sockets')) { | |
$operating_system = strtolower(PHP_OS); | |
$socket = null; | |
// If we're on Windows, handle socket creation attempt differently; and the ping command. | |
if (substr_count($operating_system, "win")) { | |
// Try to create a socket. | |
if ($socket = socket_create(AF_INET, SOCK_RAW, 1)) { | |
return perform_icmp_ping($socket, $url['site']); | |
} else { | |
// TODO: Add parsing of the Windows ping command here. | |
return null; | |
} | |
} else { | |
// Attempt to perform a setuid as root. | |
if(posix_seteuid(0)) { | |
// This could potentially be quite dangerous since we're sending this out as root. | |
// We need to determine what user we're running as, and perform another seteuid. | |
if ($socket = socket_create(AF_INET, SOCK_RAW, 1)) { | |
return perform_icmp_ping($socket, $url['site']); | |
} else { | |
return perform_fsock_ping($url); | |
} | |
} else { | |
// Only perform this if we can be assured that this function is callable. | |
if(!ini_get('safe_mode') && | |
(strpos(ini_get('disable_functions'), 'shell_exec')) == 0) { | |
// Accommodate the different ping syntax. | |
// 100 second timeout, 1 attempt. | |
if (substr_count(strtolower(PHP_OS), "hpux")) { | |
$result = shell_exec("ping -m 10 -n 1 " . $url['site']); | |
} else if (substr_count(strtolower(PHP_OS), "aix")) { | |
$result = shell_exec("ping -i 10 -c 1 " . $url['site']); | |
} else if (substr_count(strtolower(PHP_OS), "mac") || | |
substr_count(strtolower(PHP_OS), "darwin")) { | |
$result = shell_exec("ping -t 10 -c 1 " . $url['site']); | |
} else if (substr_count(strtolower(PHP_OS), "bsd")) { | |
$result = shell_exec("ping -w 10 -c 1 " . $url['site']); | |
} else { | |
$result = shell_exec("ping -W 10 -c 1 " . $url['site']); | |
} | |
if ($result == null || $result == "") { | |
return perform_fsock_ping($url); | |
} else { | |
// Parse the output. | |
$position = strpos($result, "min/avg/max"); | |
if ($position > 0) { | |
$output = trim(str_replace(" ms", "", substr($result, $position))); | |
$pieces = explode("=", $output); | |
$results = explode("/", $pieces[1]); | |
return round($results[1], 0); | |
} else { | |
return null; | |
} | |
} | |
} else { | |
return perform_fsock_ping($url); | |
} | |
} | |
} | |
} else { | |
return perform_fsock_ping($url); | |
} | |
} else { | |
return perform_fsock_ping($url); | |
} | |
} | |
/** | |
* Splits a URL into its core components. | |
* | |
* based on: http://snipplr.com/view/6526/split-an-url-into-protocol-site-and-resource-parts/ | |
* | |
* @param string $url | |
* A page URL to be parsed. (eg. http://www.google.com/search?q=test) | |
* @return associative array $result | |
* Construction: | |
* string $result['protocol'] = "http" | |
* int $result['port'] = 80 | |
* string $result['site'] = "www.google.com" | |
* string $result['resource'] = "/search?q=test" | |
*/ | |
function split_url($url) { | |
$result = array(); | |
$regex = '#^(.*?//)*([\w\.\d]*)(:(\d+))*(/*)(.*)$#'; | |
$matches = array(); | |
preg_match($regex, $url, $matches); | |
// Assign the matched parts of url to the result array | |
$result['protocol'] = $matches[1]; | |
$result['port'] = $matches[4] == NULL ? 80 : intval($matches[4]); | |
$result['site'] = $matches[2]; | |
$result['resource'] = $matches[6]; | |
// clean up the site portion by removing the trailing / | |
$result['site'] = preg_replace('#/$#', '', $result['site']); | |
// clean up the protocol portion by removing the trailing :// | |
$result['protocol'] = preg_replace('#://$#', '', $result['protocol']); | |
return $result; | |
} | |
/** | |
* A basic array comparator. | |
* | |
* As with any comparator, it takes two values, compares the two, and then returns whether or not | |
* the value should move up or down the array (or stay in place: 0) | |
* | |
* @param string $a | |
* Value to be compared against. | |
* @param string $b | |
* Value to be compared to. | |
* @return int | |
* The direction in which the element whose value is $a should move. | |
*/ | |
function comparator($a, $b) { | |
if ($a == $b) { | |
return 0; | |
} | |
return ($a < $b) ? -1 : 1; | |
} | |
/** | |
* An fsockopen() ping. | |
* | |
* This will perform a rudimentary attempt at a connection and time it | |
* in order to attempt a guess at how well the server is responding. | |
* | |
* This can support either UDP or TCP, depending on how the server is defined in | |
* the INI_FILE. | |
* | |
* @param associative array $url | |
* The array of URL request elements. | |
* @return int $status | |
* The calculated time in ms. If null, it means an error occurred. | |
*/ | |
function perform_fsock_ping($url) { | |
if (!ini_get('safe_mode') && | |
(strpos(ini_get('disable_functions'), 'fsockopen') == 0)) { | |
$start_time = microtime(true); | |
// Allow per-site UDP/TCP handling. | |
if (strtolower($url['protocol']) == "udp") { | |
$url['site'] = "udp://".$url['site']; | |
} | |
$file = fsockopen($url['site'], $url['port'], $errno, $errstr, 10); | |
$stop_time = microtime(true); | |
$status = null; | |
// The site is not responding. | |
if (!$file) { | |
return null; | |
} else { | |
fclose($file); | |
$status = ($stop_time - $start_time) * 1000; | |
$status = floor($status); | |
} | |
return $status; | |
} else { | |
return null; | |
} | |
} | |
/** | |
* An ICMP packet ping. | |
* | |
* This method has multiple facilities: | |
* 1. An attempt is made to blindly create a raw socket. | |
* 2. If the above somehow fails, perhaps due to Vista or Windows 7, | |
* it tries to use the built-in ping, and takes the final avg of that. | |
* 3. Otherwise, it will return null. This is so an error can be differentiated from a response. | |
* | |
* @param string $domain | |
* The domain name to be pinged. | |
*/ | |
function perform_icmp_ping($socket, $domain) { | |
// Set the timeout values to 2 seconds. | |
socket_set_option($socket,SOL_SOCKET,SO_RCVTIMEO, array("sec"=>2, | |
"usec"=>0)); | |
// Attempt a connection. | |
if(socket_connect($socket, $domain, null)) { | |
$packet = create_icmp_packet(); | |
// Attempt to send the packet. | |
if(socket_write($socket, $packet, strlen($packet))) { | |
$start_time = microtime(TRUE); | |
// Grab the socket success status while building our read array, and timeouts. | |
$response = socket_select($read_array = array($socket), $write_array = NULL, $f = NULL, $timeout_seconds, $timeout_milliseconds); | |
// Only move forward if the socket states it is OK (responded within given timeout). | |
if ($response > 0) { | |
$response_time = round((microtime(TRUE) - $start_time) * 1000, 0); | |
/** TODO: Perform sequence validation to avoid man-in-the-middle attacks. | |
* $result = socket_read($socket, MAX_ICMP_BYTES); | |
* $response_sequence = substr($result, 26, 2); | |
* if ($response_sequence != $packet->sequence) { | |
* return null; | |
* } */ | |
socket_close($socket); | |
return $response_time; | |
} else { | |
socket_close($socket); | |
return null; | |
} | |
} else { | |
socket_close($socket); | |
return null; | |
} | |
} else { | |
return null; | |
} | |
} | |
/** | |
* Build a basic ICMP packet. | |
* | |
* But it goes something like, where each '-' is a bit, and ~ is variable length. | |
* |--------|--------|----------------|~~~~~~~~| | |
* Type Code Checksum Data | |
* | |
* For further definition see http://tools.ietf.org/rfc/rfc0792.txt. | |
*/ | |
function create_icmp_packet() { | |
// Qualification of the packet. | |
$data = "ping from a file download proxy"; | |
// We want to send an echo request packet. | |
$type = "\x08"; | |
$code = "\x00"; | |
// As specified by RFC-792, we need to 0 out this checksum before calculating it. | |
$checksum = "\x00\x00"; | |
// Generate a random 16-bit identifier and sequence. | |
$identifier = chr(rand(0, 255)).chr(rand(0, 255)); | |
$sequence = "\x00\x00"; | |
// Generate a checksum of the almost completed packet. | |
$checksum = perform_icmp_checksum($type.$code.$checksum.$identifier.$sequence.$data); | |
// Return the built packet. | |
return ($type.$code.$checksum.$identifier.$sequence.$data); | |
} | |
/** | |
* Generate a checksum of an almost complete packet (generating this is the final piece) | |
* | |
* This checksum generation is based off of in_cksum from | |
* http://ws.edu.isoc.org/materials/src/ping.c | |
* | |
* @param short $packet | |
* The packet containing everything but the checksum. | |
* | |
* @return short $checksum | |
* The checksum of the given packet. | |
*/ | |
function perform_icmp_checksum($packet) { | |
// Ensure there are no trailing bits, if so, add another bit. | |
if(strlen($packet) % 2) { | |
$packet.="\x00"; | |
} | |
// First, create a new array of unsigned shorts from our packet | |
$bit_array = unpack("n*",$packet); | |
// Now get a sum total of the array. | |
$bit_sum = array_sum($bit_array); | |
// Now do some bit shifting | |
while($bit_sum >> 16) { | |
$bit_sum = ($bit_sum >> 16) + ($bit_sum & 65535); | |
} | |
// Return the unsigned short truncated sum. | |
return pack('n*', ~$bit_sum); | |
} | |
?> |
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