Add IPv6 support

Split IPv4 and IPv6 calculations into different JS files to make them easier to understand.

IDE decided to format HTML code and I left it as-is.

calculations.js

@@ -0,0 +1,44 @@
+function inet_ntoa(mode, addrint) {
+    var fn = "inet_ntoa_" + mode;
+    return window[fn](addrint);
+}
+
+function inet_aton(mode, addrint) {
+    var fn = "inet_aton_" + mode;
+    return window[fn](addrint);
+}
+
+function network_address(mode, addrint) {
+    var fn = "network_address_" + mode;
+    return window[fn](addrint);
+}
+
+function subnet_addresses(mode, addrint) {
+    var fn = "subnet_addresses_" + mode;
+    return window[fn](addrint);
+}
+
+function subnet_first_address_useable(mode, addrint) {
+    var fn = "subnet_first_address_useable_" + mode;
+    return window[fn](addrint);
+}
+
+function subnet_last_address_useable(mode, addrint) {
+    var fn = "subnet_last_address_useable_" + mode;
+    return window[fn](addrint);
+}
+
+function subnet_last_address(mode, subnet, mask) {
+    var fn = "subnet_last_address_" + mode;
+    return window[fn](mode, subnet, mask);
+}
+
+function subnet_netmask(mode, addrint) {
+    var fn = "subnet_netmask_" + mode;
+    return window[fn](addrint);
+}
+
+function num_hosts(mode, useableFirst, useableLast) {
+    var fn = "num_hosts_" + mode;
+    return window[fn](useableFirst, useableLast);
+}

calculations_4.js

@@ -0,0 +1,60 @@
+function inet_ntoa_4(addrint) {
+    return (
+        ((addrint >> 24) & 0xff) +
+        "." +
+        ((addrint >> 16) & 0xff) +
+        "." +
+        ((addrint >> 8) & 0xff) +
+        "." +
+        (addrint & 0xff)
+    );
+};
+
+function inet_aton_4(addrstr) {
+    var re = /^([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3})$/;
+    var res = re.exec(addrstr);
+
+    if (res === null) {
+        return null;
+    }
+
+    for (var i = 1; i <= 4; i++) {
+        if (res[i] < 0 || res[i] > 255) {
+            return null;
+        }
+    }
+
+    return (res[1] << 24) | (res[2] << 16) | (res[3] << 8) | res[4];
+}
+
+function network_address_4(ip, mask) {
+    var maskbits = 0;
+    for (var i = 31 - mask; i >= 0; i--) {
+        ip &= ~1 << i;
+    }
+    return ip;
+}
+
+function subnet_addresses_4(mask) {
+    return 1 << (32 - mask);
+}
+
+function subnet_first_address_useable_4(addrint) {
+    return addrint + 1;
+}
+
+function subnet_last_address_useable_4(addrint) {
+    return addrint - 1;
+}
+
+function subnet_last_address_4(mode, subnet, mask) {
+    return subnet + subnet_addresses(mode, mask) - 1;
+}
+
+function subnet_netmask_4(mask) {
+    return network_address(4, 0xffffffff, mask);
+}
+
+function num_hosts_4(useableFirst, useableLast) {
+    return 1 + useableLast - useableFirst;
+}

calculations_6.js

@@ -0,0 +1,79 @@
+function inet_ntoa_6(addrint) {
+    return "" +
+        ((addrint >> 112n) & BigInt(0xffff)).toString(16) +
+        ":" +
+        ((addrint >> 96n) & BigInt(0xffff)).toString(16) +
+        ":" +
+        ((addrint >> 80n) & BigInt(0xffff)).toString(16) +
+        ":" +
+        ((addrint >> 64n) & BigInt(0xffff)).toString(16) +
+        ":" +
+        ((addrint >> 48n) & BigInt(0xffff)).toString(16) +
+        ":" +
+        ((addrint >> 32n) & BigInt(0xffff)).toString(16) +
+        ":" +
+        ((addrint >> 16n) & BigInt(0xffff)).toString(16) +
+        ":" +
+        (addrint & BigInt(0xffff)).toString(16);
+}
+
+function inet_aton_6(addrstr) {
+    var re =
+        /^([0-9a-f]{1,4})\:([0-9a-f]{1,4})\:([0-9a-f]{1,4})\:([0-9a-f]{1,4})\:([0-9a-f]{1,4})\:([0-9a-f]{1,4})\:([0-9a-f]{1,4})\:([0-9a-f]{1,4})$/;
+    var res = re.exec(addrstr);
+
+    if (res === null) {
+        return null;
+    }
+
+    for (var i = 1; i <= 8; i++) {
+        if (res[i] < 0 || res[i] > 0xffff) {
+            return null;
+        }
+    }
+
+    var r1 = BigInt(parseInt(res[1], 16)) << 112n;
+    var r2 = BigInt(parseInt(res[2], 16)) << 96n;
+    var r3 = BigInt(parseInt(res[3], 16)) << 80n;
+    var r4 = BigInt(parseInt(res[4], 16)) << 64n;
+    var r5 = BigInt(parseInt(res[5], 16)) << 48n;
+    var r6 = BigInt(parseInt(res[6], 16)) << 32n;
+    var r7 = BigInt(parseInt(res[7], 16)) << 16n;
+    var r8 = BigInt(parseInt(res[8], 16));
+
+    var rt = r1 | r2 | r3 | r4 | r5 | r6 | r7 | r8;
+
+    return rt;
+}
+
+function network_address_6(ip, mask) {
+    var maskbits = 0;
+    for (var i = 128 - mask; i >= 0; i--) {
+        ip &= ~1 << i;
+    }
+    return ip;
+}
+
+function subnet_addresses_6(mask) {
+    return 1n << (128n - BigInt(mask));
+}
+
+function subnet_first_address_useable_6(addrint) {
+    return addrint + 1n;
+}
+
+function subnet_last_address_useable_6(addrint) {
+    return addrint - 1n;
+}
+
+function subnet_last_address_6(mode, subnet, mask) {
+    return subnet + subnet_addresses(mode, mask) - 1n;
+}
+
+function subnet_netmask_6(mask) {
+    return undefined;
+}
+
+function num_hosts_6(useableFirst, useableLast) {
+    return 1n + useableLast - useableFirst;
+}

gennum.php

@@ -1,5 +1,5 @@
-<?
-for ($i=0;$i<=32; $i++) {
+<?php
+for ($i=0;$i<=128; $i++) {
 
 $str = '/'.$i;
 $font = 2;