<?
/**
* This class performs a dhcp lease query and passes back
* all info pertaining to the lease.
*
* Copyright (c) 2010 by Pat Winn (pat@patwinn.com)
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND PAT WINN DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL PAT WINN BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
* OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* Portions of the parser code were adapted from code originally written by
* Angelo R. DiNardi (angelo@dinardi.name).
*
* Many thanks also to all those in the ISC DHCP hacker community and the
* folks at ISC who chimed in to help figure this stuff out. Without the
* input..I would never have gotten to this point. :-)
*
* If this file looks funky to you, try setting tab stops=4.
*
* @author Pat Winn (pat@patwinn.com)
* @date 06/17/2010
* @version 1.0
*/
require_once("dhcpAPI.php");
class dhcpLeaseQuery
{
// contains packet data
private $packet = Array();
// actual packet to be sent or received
private $myPacket = '';
// what to use for our giaddr (where will we send the leaseactive/etc. packets back to)
private $my_giaddr = '';
// IP address of the dhcpd server
private $my_server = '';
// our socket handle
private $socket = '';
// the lease info packet we hope to get back
public $lease = '';
// data types for given options
private $options = '';
// array containing the various message types we may encounter
private $messageTypes = '';
/**
* Constructor
* @$myGiaddr = IP address to use for giaddr field
* @$dhcpServer = IP address of the dhcpd server we want to query
* @returns nothing
*/
function __construct(&$myGiaddr, &$dhcpServer) {
$this->my_giaddr = $myGiaddr;
$this->my_server = $dhcpServer;
$this->options = array(
1 => array('name' => 'subnet_mask', 'type' => 'ip'),
2 => array('name' => 'time_offset', 'type' => 'int'),
3 => array('name' => 'router', 'type' => 'ip'),
6 => array('name' => 'dns_server', 'type' => 'ip'),
7 => array('name' => 'log_server', 'type' => 'ip'),
12 => array('name' => 'host_name', 'type' => 'string'),
15 => array('name' => 'domain_name', 'type' => 'string'),
23 => array('name' => 'ttl', 'type' => 'int'),
28 => array('name' => 'broadcast_address', 'type' => 'ip'),
43 => array('name' => 'vendor_specific', 'type' => 'string'),
50 => array('name' => 'requested_ip_address', 'type' => 'ip'),
51 => array('name' => 'lease_time', 'type' => 'int'),
53 => array('name' => 'message_type', 'type' => 'messageType'),
54 => array('name' => 'server_id', 'type' => 'ip'),
55 => array('name' => 'parameter_request', 'type' => 'binary'),
57 => array('name' => 'max_message_size', 'type' => 'int'),
58 => array('name' => 'renewal_time', 'type' => 'int'),
59 => array('name' => 'rebinding_time', 'type' => 'int'),
61 => array('name' => 'client_id', 'type' => 'mac'),
60 => array('name' => 'vendor_class_identifier', 'type' => 'string'),
66 => array('name' => 'tftp_server', 'type' => 'string'),
82 => array('name' => 'option-82', 'type' => 'string'),
91 => array('name' => 'client-last-transaction-time', 'type' => 'int'),
92 => array('name' => 'associated-ip', 'type' => 'string')
);
$this->messageTypes = array(
1 => 'discover',
2 => 'offer',
3 => 'request',
4 => 'decline',
5 => 'ack',
6 => 'nak',
7 => 'release',
8 => 'inform',
10 => 'DHCPLEASEQUERY',
11 => 'DHCPLEASEUNASSIGNED',
12 => 'DHCPLEASEUNKNOWN',
13 => 'DHCPLEASEACTIVE'
);
// build the basic packet
$this->packet['op'] = D_BOOTREQUEST;
$this->packet['htype'] = D_ETHERNET;
$this->packet['hlen'] = '06';
$this->packet['hops'] = '00';
$this->packet['xid'] = sprintf("%08x\n", mt_rand(0, 0xFFFFFF));
$this->packet['secs'] = '0000';
$this->packet['flags'] = '0000';
$this->packet['yiaddr'] = $this->ip2hex("0.0.0.0");
$this->packet['siaddr'] = $this->ip2hex("0.0.0.0");
$this->packet['giaddr'] = $this->ip2hex($myGiaddr);
$this->packet['chaddr'] = $this->pad('', 32);
$this->packet['sname'] = $this->pad('', 128);
$this->packet['file'] = $this->pad('', 256);
$this->packet['magic'] = D_MAGIC;
$this->packet['options'] = $this->int2hex(53) . $this->int2hex(1) . D_LEASEQUERY;
$this->packet['options'] .= $this->int2hex(55) . $this->int2hex(count($this->options));
// add all possible options to the list and see what all we get back..
foreach($this->options as $k => $v) {
$this->packet['options'] .= $this->int2hex($k);
}
// don't forget the end octet!
$this->packet['options'] .= $this->int2hex(255);
}
/**
* Send a DHCPLEASEQUERY packet to the remote dhcpd
* @$ipaddr = IP address to query information for
* @returns true if sent, false if not
*/
public function sendQuery(&$ipaddr) {
// add the client ip that we want to query for to the packet
$this->packet['ciaddr'] = $this->ip2hex($ipaddr);
// pack it into binary fun..
$this->myPacket =
pack("H2H2H2H2H8H4H4H8H8H8H8H32H128H256H8H*",
$this->packet['op'], $this->packet['htype'], $this->packet['hlen'],
$this->packet['hops'], $this->packet['xid'], $this->packet['secs'],
$this->packet['flags'], $this->packet['ciaddr'], $this->packet['yiaddr'],
$this->packet['siaddr'], $this->packet['giaddr'], $this->packet['chaddr'],
$this->packet['sname'], $this->packet['file'],
$this->packet['magic'], $this->packet['options']
);
// open a socket to the server
$this->socket = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP);
socket_set_option($this->socket, SOL_SOCKET, SO_BROADCAST, 1);
socket_bind($this->socket, $this->my_giaddr, 67);
// send the packet (finally)..
$error = socket_sendto($this->socket, $this->myPacket,
strlen($this->myPacket), 0, $this->my_server, 67);
if ($error === FALSE) {
print("Send failed for address");
print_r("ERROR: ". $error ." while trying to send.");
return(false);
} else {
echo "Sent ". $error ." bytes\n";
return(true);
}
}
/**
* Receive a lease query response packet
* @returns array with lease info or false if failure
*/
public function receive() {
if($this->socket == null) {
$this->socket = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP);
socket_set_option($this->fp, SOL_SOCKET, SO_REUSEADDR, 1);
socket_bind($this->socket, $this->my_giaddr, 67);
}
$pkt = false;
$port = 67;
if (false !== ($pkt = socket_recvfrom($this->socket, $buf, 2048, MSG_WAITALL, $this->my_server, $port))) {
$this->log('leaseQuery.php: '. "Rec: ". $pkt . "\nbytes:: ". $buf);
} else {
$this->log('leaseQuery.php: '. "ERR: ". socket_strerror(socket_last_error($this->socket)));
return(false);
}
// close the listener socket
try {
socket_close($this->socket);
} catch(Exception $t) {}
// parse the packet and save off the data in our array
$this->parse($buf);
if($this->parse($buf) !== false) {
return($this->lease);
} else {
return(false);
}
}
/**
* Parse an incoming packet and put it's contents into an array
* @$_pkt = packet payload to parse
*/
private function parse($_pkt) {
// unpack the binary octets from the packet payload into something we can work with
$_format = "H2op/H2htype/H2hlen/H2hops/H8xid/H4secs/H4flags/H8ciaddr/";
$_format .= "H8yiaddr/H8siaddr/H8giaddr/H32chaddr/H128sname/H256file/H8magic/H*options";
$this->lease = unpack($_format, $_pkt);
// check the packet's magic number and return out without doing anything if bad
if(!$this->lease['magic'] == '63825363') {
$this->log("BAD MAGIC: ". $this->lease['magic']);
return(false);
}
// grab the options field from the payload and save it for later
$optionData = $this->lease['options'];
$pos = 0;
$this->lease['cid'] = ''; // option 82 circuit id
$this->lease['rid'] = ''; // option 82 remote id
// loop through all the options sent to us and parse things out
// (this is ugly and should be cleaned up/optimized some later..<blush>)
while(strlen($optionData) > $pos) {
// get the code number for the current option
$code = base_convert(substr($optionData, $pos, 2), 16, 10);
$pos += 2;
// get the option field length for the current option
$len = base_convert(substr($optionData, $pos, 2), 16, 10);
$pos += 2;
// get the bytes that make up the current option info
$curoptdata = substr($optionData, $pos, $len*2);
$pos += $len*2;
// attempt to look up the data type, etc. for the current option code/type
$optinfo = $this->options[$code];
// if we found the code in the list..parse things out
if($optinfo !== null) {
$translatedData = null;
// check the data type and determine how to parse it
switch($optinfo['type']) {
case 'int':
$translatedData = base_convert($curoptdata, 16, 10);
break;
case 'string':
// if we are dealing with option 82, loop through it's sub options
// as appropriate
if($code == 82) {
$_pos = 0;
$o82 = substr($curoptdata, $_pos, $len*2);
while(strlen($o82) > $_pos) {
$_code = base_convert(substr($o82, $_pos, 2), 16, 10);
$_pos += 2;
$_len = base_convert(substr($o82, $_pos, 2), 16, 10);
$_pos += 2;
$curo82 = substr($o82, $_pos, $_len*2);
$_pos += $_len*2;
// why in the heck does sub-option 2 not convert the same as
// sub-option 1 (cid)? It's in the same format and
// should convert the same. FIX THIS!!!!!
($_code == 1) ? $field = "cid" : $field = "rid";
$this->lease[$field] = $this->hex2str($curo82);
}
} else {
$translatedData = $this->hex2str($curoptdata);
}
break;
case 'ip':
$translatedData = $this->hex2ip($curoptdata);
break;
case 'messageType':
$translatedData = $this->messageTypes[$this->hex2int($curoptdata)];
break;
default:
$translatedData = $curoptdata;
}
$this->lease[$optinfo['name']] = $translatedData;
} else {
$this->lease[$code] = $curoptdata;
}
}
// Now clean up a few of the values a bit further.
// ** Note that I've put most of these into try/catch blocks but have not added
// ** any real error handling to most. Just let it keep going without breaking for now.
try {
$this->lease['chaddr'] = $this->str2mac(substr($this->lease['chaddr'], 0, 12));
} catch(Exception $e0) {}
try {
$this->lease['client_id'] = substr($this->lease['client_id'], 2);
} catch(Exception $e1) {}
try {
$this->lease['ciaddr'] = $this->hex2ip($this->lease['ciaddr']);
} catch(Exception $e3) {}
try {
$this->lease['yiaddr'] = $this->hex2ip($this->lease['yiaddr']);
} catch(Exception $e4) {}
try {
$this->lease['siaddr'] = $this->hex2ip($this->lease['siaddr']);
} catch(Exception $e5) {}
try {
$this->lease['giaddr'] = $this->hex2ip($this->lease['giaddr']);
} catch(Exception $e6) {}
// set the start/end/renew/rebind/total times to a human readable date/time
// before altering their values below
$this->setTimes(
$this->lease['lease_time'],
$this->lease['renewal_time'],
$this->lease['rebinding_time'],
$this->lease['client-last-transaction-time']
);
try {
$this->lease['lease_time'] = $this->toDateStr($this->lease['lease_time']);
} catch(Exception $e7) {}
try {
$this->lease['renewal_time'] = $this->toDateStr($this->lease['renewal_time']);
} catch(Exception $e8) {}
try {
$this->lease['rebinding_time'] = $this->toDateStr($this->lease['rebinding_time']);
} catch(Exception $e8) {}
try {
$this->lease['client-last-transaction-time'] = $this->toDateStr($this->lease['client-last-transaction-time']);
} catch(Exception $e9) {}
}
/**
* Convert the lease start/end/renewal/rebinding/cltt seconds to real dates/times in mysql format
* Also set the total number of seconds the lease was given for
* @$_lt = lease time in seconds (no relation to the epoch)
* @$_rt = renewal time in seconds (no relation to the epoch)
* @$_bt = rebinding time in seconds (no relation to the epoch)
* @$_ct = client last transmission time (no relation to the epoch)
* @returns nothing, merely attempts to add the appropriate fields to the lease array which
* already contains the rest of the current lease info
*/
private function setTimes(&$_lt, &$_rt, &$_bt, &$_ct) {
try {
$_now = time();
$startSecs = ($_now - $_ct);
$totalSecs = ($_ct + $_lt);
$this->lease['curTime'] = date("Y-m-d H:i:s");
$this->lease['clttTime'] = date("Y-m-d H:i:s", $startSecs);
$this->lease['startTime'] = date("Y-m-d H:i:s", $startSecs);
$this->lease['renew'] = date("Y-m-d H:i:s", ($_now + $_rt));
$this->lease['rebind'] = date("Y-m-d H:i:s", ($_now + $_bt));
$this->lease['endTime'] = date("Y-m-d H:i:s", ($startSecs + $totalSecs));
$this->lease['leaseTime'] = $totalSecs;
} catch(Exception $t) {}
}
/**
* Convert a string to mac address w/ :'s inserted
* @$s = string to convert
* @returns converted string or original string if error
*/
private function str2mac($s) {
try {
$oct1 = $s{0} . $s{1};
$oct2 = $s{2} . $s{3};
$oct3 = $s{4} . $s{5};
$oct4 = $s{6} . $s{7};
$oct5 = $s{8} . $s{9};
$oct6 = $s{10} . $s{11};
return($oct1 .":". $oct2 .":". $oct3 .":". $oct4 .":". $oct5 .":". $oct6);
} catch(Exception $r) {
return($s);
}
}
/**
* Convert a value to hex
* @$s = value to convert
* @returns converted hex value or -1 upon failure
*/
private function str2hex($s) {
$hex = '';
try {
for ($i = 0 ; $i < strlen($s); $i++) {
$hex .= dechex(ord($s[$i]));
}
} catch(Exception $x) {
return(-1);
}
return($hex);
}
/**
* Convert a hex value to string
* @$hex = hex octet(s) to convert
* @returns converted string or false upon failure
*/
private function hex2str($hex) {
$str = '';
for ($i = 0 ; $i < strlen($hex) - 1 ; $i += 2) {
$str .= chr(hexdec($hex[$i] . $hex[$i + 1]));
}
return($str);
}
// convert an ip address to hex values
/*
* Convert an IP address to hex octets
* @$ip = IP address to convert
* @returns converted IP or -1 if failure
*/
private function ip2hex($ip) {
$t = explode(".", $ip);
try {
$hex = $this->int2hex($t[0]) . $this->int2hex($t[1]) . $this->int2hex($t[2]) . $this->int2hex($t[3]);
return($hex);
} catch(Exception $y) {
return(-1);
}
}
/**
* Convert a hex value back to an ip address
* @$hex = value to convert
* @returns string containing ip address or -1 upon failure
*/
private function hex2ip($hex) {
$retVal = -1;
try {
$retVal =
$this->hex2int($hex[0] . $hex[1]) .".".
$this->hex2int($hex[2] . $hex[3]) .".".
$this->hex2int($hex[4] . $hex[5]) .".".
$this->hex2int($hex[6] . $hex[7]);
} catch(Exception $r) {
$retVal = -1;
}
return($retVal);
}
/*
* Convert an int value to a 0 padded hex value
* @$int = int to pad
* @returns padded value or -1 if failure
*/
private function int2hex($int) {
try {
$hex = base_convert($int, 10, 16);
switch(strlen($hex)) {
case 1:
case 3:
case 7: $hex = '0' . $hex; break;
case 5: $hex = '000' . $hex; break;
}
return $hex;
} catch(Exception $z) {
return(-1);
}
}
/**
* Convert a hex value back to an int value
* @$hex = value to convert
* @returns converted int value or -1 if failure
*/
private function hex2int($hex) {
$retVal = -1;
try {
$retVal = base_convert($hex, 16, 10);
} catch(Exception $g) {
$retVal = -1;
}
return($retVal);
}
/**
* Convert an int to number of days/hours/mins/secs
* Has no relation to the epoch, just the number of days/hours/mins/secs
* @$t = number to convert
* @returns string containing days, hours, mins, secs padded w/ 0's if applicable
*/
private function toDateStr($t) {
$hours = $this->lpad(intVal($t / 3600), 2);
$days = $this->lpad(intVal($hours / 24), 2);
$mins = $this->lpad(intVal(($t / 60) - ($hours * 60)), 2);
$secs = $this->lpad(intVal($t % 60), 2);
return($days ."d ". $hours ."h ". $mins ."m ". $secs ."s");
}
/**
* Pad a field to a given number of 0's
* @$s = string to add padding to (defaults to right side pad)
* @$cnt = number of 0's to pad with
* @returns padded string
*/
private function pad($s, $cnt) {
return(str_pad($s, $cnt, '0'));
}
/**
* Pad a field to a given number of 0's
* @$s = string to add padding to (defaults to left side pad)
* @$cnt = number of 0's to pad with
* @returns padded string
*/
private function lpad($s, $cnt) {
return(str_pad($s, $cnt, '0', STR_PAD_LEFT));
}
/**
* debug function...
*/
private function log($s) {
$fp = fopen('/var/log/dhcp.log', 'a+');
fputs($fp, $s ."\n");
fclose($fp);
}
}
?>
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