PHP ping

 ?1 <?php ?2 /// start ping.inc.php /// ?3 ??4 $g_icmp_error = "No Error"; ?5 ??6 // timeout in ms ?7 function ping($host, $timeout) ?8 { ?9 ????$port = 0; 10 ????$datasize = 64; 11 ????global $g_icmp_error; 12 ????$g_icmp_error = "No Error"; 13 ????$ident = array(ord(‘J‘), ord(‘C‘)); 14 ????$seq = array(rand(0, 255), rand(0, 255)); 15 ?16 ????$packet = ‘‘; 17 ????$packet .= chr(8); // type = 8 : request 18 ????$packet .= chr(0); // code = 0 19 ?20 ????$packet .= chr(0); // checksum init 21 ????$packet .= chr(0); // checksum init 22 ?23 ????$packet .= chr($ident[0]); // identifier 24 ????$packet .= chr($ident[1]); // identifier 25 ?26 ????$packet .= chr($seq[0]); // seq 27 ????$packet .= chr($seq[1]); // seq 28 ?29 ????for ($i = 0; $i < $datasize; $i++) 30 ????????$packet .= chr(0); 31 ?32 ????$chk = icmpChecksum($packet); 33 ?34 ????$packet[2] = $chk[0]; // checksum init 35 ????$packet[3] = $chk[1]; // checksum init 36 ?37 ????$sock = socket_create(AF_INET, SOCK_RAW, getprotobyname(‘icmp‘)); 38 ????$time_start = microtime(true); 39 ????socket_sendto($sock, $packet, strlen($packet), 0, $host, $port); 40 ?41 ?42 ????$read = array($sock); 43 ????$write = NULL; 44 ????$except = NULL; 45 ?46 ????$select = socket_select($read, $write, $except, 0, $timeout * 1000); 47 ????if ($select === NULL) { 48 ????????$g_icmp_error = "Select Error"; 49 ????????socket_close($sock); 50 ????????return -1; 51 ????} elseif ($select === 0) { 52 ????????$g_icmp_error = "Timeout"; 53 ????????socket_close($sock); 54 ????????return -1; 55 ????} 56 ?57 ????$recv = ‘‘; 58 ????$time_stop = microtime(true); 59 ????socket_recvfrom($sock, $recv, 65535, 0, $host, $port); 60 ????$recv = unpack(‘C*‘, $recv); 61 ?62 ????if ($recv[10] !== 1) // ICMP proto = 1 63 ????{ 64 ????????$g_icmp_error = "Not ICMP packet"; 65 ????????socket_close($sock); 66 ????????return -1; 67 ????} 68 ?69 ????if ($recv[21] !== 0) // ICMP response = 0 70 ????{ 71 ????????$g_icmp_error = "Not ICMP response"; 72 ????????socket_close($sock); 73 ????????return -1; 74 ????} 75 ?76 ????if ($ident[0] !== $recv[25] || $ident[1] !== $recv[26]) { 77 ????????$g_icmp_error = "Bad identification number"; 78 ????????socket_close($sock); 79 ????????return -1; 80 ????} 81 ?82 ????if ($seq[0] !== $recv[27] || $seq[1] !== $recv[28]) { 83 ????????$g_icmp_error = "Bad sequence number"; 84 ????????socket_close($sock); 85 ????????return -1; 86 ????} 87 ?88 ????$ms = bcmul(bcsub($time_stop, $time_start, 6), 1000); 89 ?90 ????if ($ms < 0) { 91 ????????$g_icmp_error = "Response too long"; 92 ????????$ms = -1; 93 ????} 94 ?95 ????socket_close($sock); 96 ?97 ????return $ms; 98 } 99 100 function icmpChecksum($data)101 {102 ????$bit = unpack(‘n*‘, $data);103 ????$sum = array_sum($bit);104 105 ????if (strlen($data) % 2) {106 ????????$temp = unpack(‘C*‘, $data[strlen($data) - 1]);107 ????????$sum += $temp[1];108 ????}109 110 ????$sum = ($sum >> 16) + ($sum & 0xffff);111 ????$sum += ($sum >> 16);112 113 ????return pack(‘n*‘, ~$sum);114 }115 116 function getLastIcmpError()117 {118 ????global $g_icmp_error;119 ????return $g_icmp_error;120 }121 /// end ping.inc.php ///

$ping = ping(‘www.baidu.com‘,200);if ($ping > 0) { ???// ok ?} else { ???// failed}