问题
Our Datacenter has given us a JSON dump from all of our machines to import into our own inventory management system. This supplies the IP Blocks such as (192.168.1.1/26) but as I am importing hundreds of blocks, I would like to also calculate the Netmask and Gateway.
I looked over the networking functions on the PHP Doxygen but was not able to find any way to do this. How can I calculate Netmask/Gateway from an IP Block?
回答1:
You can calculate the ip and mask using something like this:
$ip_with_mask = '192.168.1.1/26';
list($ip, $mask_int) = explode('/', $ip_with_mask);
$mask_nr = (pow(2, $mask_int) - 1) << (32 - $mask_int);
//pow(2, $x) - 1 changes the number to a number made of that many set bits
//and $y << (32 - $x) shifts it to the end of the 32 bits
$mask = long2ip($mask_nr);
$subnet_ip = long2ip(ip2long($ip) & $mask_nr);
$gateway_ip = long2ip((ip2long($ip) & $mask_nr) + 1);
回答2:
<?php
/*
I have snipped this script from online and modified to give JSON output
*/
$networkArray = array();
// Define your IP address detail in below line
$my_net_info=rtrim('10.240.1.1/22');
if (! ereg('^([0-9]{1,3}\.){3}[0-9]{1,3}(( ([0-9]{1,3}\.){3}[0-9]{1,3})|(/[0-9]{1,2}))$',$my_net_info)){
$networkArray['error'] = "Invalid Input";
}
if (ereg("/",$my_net_info)){ //if cidr type mask
$dq_host = strtok("$my_net_info", "/");
$cdr_nmask = strtok("/");
if (!($cdr_nmask >= 0 && $cdr_nmask <= 32)){
$networkArray['error'] = "Invalid CIDR value. Try an integer 0 - 32";
}
$bin_nmask=cdrtobin($cdr_nmask);
$bin_wmask=binnmtowm($bin_nmask);
} else { //Dotted quad mask?
$dqs=explode(" ", $my_net_info);
$dq_host=$dqs[0];
$bin_nmask=dqtobin($dqs[1]);
$bin_wmask=binnmtowm($bin_nmask);
if (ereg("0",rtrim($bin_nmask, "0"))) { //Wildcard mask then? hmm?
$bin_wmask=dqtobin($dqs[1]);
$bin_nmask=binwmtonm($bin_wmask);
if (ereg("0",rtrim($bin_nmask, "0"))){ //If it's not wcard, whussup?
$networkArray['error'] = "Invalid Netmask";
}
}
$cdr_nmask=bintocdr($bin_nmask);
}
//Check for valid $dq_host
if(! ereg('^0.',$dq_host)){
foreach( explode(".",$dq_host) as $octet ){
if($octet > 255){
$networkArray['error'] = "Invalid IP Address";
}
}
}
if(!empty($networkArray['error'])){
echo json_encode($networkArray);
exit;
}
$bin_host=dqtobin($dq_host);
$bin_bcast=(str_pad(substr($bin_host,0,$cdr_nmask),32,1));
$bin_net=(str_pad(substr($bin_host,0,$cdr_nmask),32,0));
$bin_first=(str_pad(substr($bin_net,0,31),32,1));
$bin_last=(str_pad(substr($bin_bcast,0,31),32,0));
$host_total=(bindec(str_pad("",(32-$cdr_nmask),1)) - 1);
if ($host_total <= 0){ //Takes care of 31 and 32 bit masks.
$bin_first="N/A" ; $bin_last="N/A" ; $host_total="N/A";
if ($bin_net === $bin_bcast) $bin_bcast="N/A";
}
//Determine Class
if (ereg('^0',$bin_net)){
$class="A";
$dotbin_net= "0 " . substr(dotbin($bin_net,$cdr_nmask),1) ;
}elseif (ereg('^10',$bin_net)){
$class="B";
$dotbin_net= "10 " . substr(dotbin($bin_net,$cdr_nmask),2) ;
}elseif (ereg('^110',$bin_net)){
$class="C";
$dotbin_net= "110 " . substr(dotbin($bin_net,$cdr_nmask),3) ;
}elseif (ereg('^1110',$bin_net)){
$class="D";
$dotbin_net= "1110 " . substr(dotbin($bin_net,$cdr_nmask),4) ;
$special="Multicast Address Space";
}else{
$class="E";
$dotbin_net= "1111 " . substr(dotbin($bin_net,$cdr_nmask),4) ;
$special="Experimental Address Space";
}
if (ereg('^(00001010)|(101011000001)|(1100000010101000)',$bin_net)){
$special='RFC-1918 Private Internet Address';
}
// Print Results
$networkArray['class'] = $class;
$networkArray['address'] = $dq_host;
$networkArray['mask'] = bintodq($bin_nmask);
$networkArray['cdr'] = $cdr_nmask;
$networkArray['wildcard'] = bintodq($bin_wmask);
$networkArray['network'] = bintodq($bin_net);
$networkArray['broadcast'] = bintodq($bin_bcast);
$networkArray['hostmin'] = bintodq($bin_first);
$networkArray['hostmax'] = bintodq($bin_last);
$networkArray['hostnet'] = $host_total;
$networkArray['special'] = $special;
$networkArray['bin-address'] = dotbin($bin_host,$cdr_nmask);
$networkArray['bin-mask'] = dotbin($bin_nmask, $cdr_nmask);
$networkArray['bin-wildcard'] = dotbin($bin_wmask, $cdr_nmask);
$networkArray['bin-network'] = $dotbin_net;
$networkArray['bin-broadcast'] = dotbin($bin_bcast, $cdr_nmask);
$networkArray['bin-hostmin'] = dotbin($bin_first, $cdr_nmask);
$networkArray['bin-hostmax'] = dotbin($bin_last, $cdr_nmask);
echo json_encode($networkArray);
function binnmtowm($binin){
$binin=rtrim($binin, "0");
if (!ereg("0",$binin) ){
return str_pad(str_replace("1","0",$binin), 32, "1");
} else return "1010101010101010101010101010101010101010";
}
function bintocdr ($binin){
return strlen(rtrim($binin,"0"));
}
function bintodq ($binin) {
if ($binin=="N/A") return $binin;
$binin=explode(".", chunk_split($binin,8,"."));
for ($i=0; $i<4 ; $i++) {
$dq[$i]=bindec($binin[$i]);
}
return implode(".",$dq) ;
}
function bintoint ($binin){
return bindec($binin);
}
function binwmtonm($binin){
$binin=rtrim($binin, "1");
if (!ereg("1",$binin)){
return str_pad(str_replace("0","1",$binin), 32, "0");
} else return "1010101010101010101010101010101010101010";
}
function cdrtobin ($cdrin){
return str_pad(str_pad("", $cdrin, "1"), 32, "0");
}
function dotbin($binin,$cdr_nmask){
// splits 32 bit bin into dotted bin octets
if ($binin=="N/A") return $binin;
$oct=rtrim(chunk_split($binin,8,"."),".");
if ($cdr_nmask > 0){
$offset=sprintf("%u",$cdr_nmask/8) + $cdr_nmask ;
return substr($oct,0,$offset ) . substr($oct,$offset) ;
} else {
return $oct;
}
}
function dqtobin($dqin) {
$dq = explode(".",$dqin);
for ($i=0; $i<4 ; $i++) {
$bin[$i]=str_pad(decbin($dq[$i]), 8, "0", STR_PAD_LEFT);
}
return implode("",$bin);
}
function inttobin ($intin) {
return str_pad(decbin($intin), 32, "0", STR_PAD_LEFT);
}
?>
回答3:
The ip address is logical and'ed with the subnet_mask. The subnet_mask can be used to carve out many net_id. Read here for an example: http://www.garykessler.net/library/subnet_masks.html.
来源：https://stackoverflow.com/questions/19769747/calculate-netmask-gateway-from-ip-blocks