better IP validation

app/Support/Ip.php

@@ -0,0 +1,44 @@
+<?php
+
+namespace App\Support;
+
+use Illuminate\Support\Str;
+
+class Ip
+{
+    public static function inNetwork(string $ip, string $network): bool
+    {
+        if (Str::contains($network, '/')) {
+            [$subnet, $mask] = explode('/', $network);
+            $subnet = inet_pton($subnet);
+            $ip = inet_pton($ip);
+
+            $mask = (int) $mask;
+            $maskBytes = (int) floor($mask / 8);
+            $maskBits = $mask % 8;
+
+            if ($maskBytes > 0) {
+                $subnetBytes = substr($subnet, 0, $maskBytes);
+                $ipBytes = substr($ip, 0, $maskBytes);
+
+                if ($subnetBytes !== $ipBytes) {
+                    return false;
+                }
+            }
+
+            if ($maskBits > 0) {
+                $maskValue = chr(pow(2, $maskBits) - 1);
+                $subnetByte = ord($subnet[$maskBytes]);
+                $ipByte = ord($ip[$maskBytes]);
+
+                if (($subnetByte & $maskValue) !== ($ipByte & $maskValue)) {
+                    return false;
+                }
+            }
+
+            return true;
+        }
+
+        return $ip === $network;
+    }
+}

routes/web.php

@@ -6,6 +6,7 @@ use App\Http\Controllers\EnvironmentController;
 use App\Http\Controllers\OrganisationController;
 use App\Http\Controllers\ServerController;
 use App\Models\Server;
+use App\Support\Ip;
 use Illuminate\Http\Request;
 use Illuminate\Support\Facades\Route;
 use Inertia\Inertia;
@@ -67,9 +68,16 @@ Route::post('/provision-callback', function (Request $request) {
 
     $server = Server::find($validated['server_id']);
 
+    // Check against ipv4 and ipv6
+    $isValidIp = false;
+    if ($server->ipv4 && Ip::inNetwork($request->ip(), $server->ipv4)) {
+        $isValidIp = true;
+    }
+    if ($server->ipv6 && Ip::inNetwork($request->ip(), $server->ipv6)) {
+        $isValidIp = true;
+    }
 
-
-    if ($request->ip() !== $server->ipv4 && inet_pton($request->ip()) !== inet_pton($server->ipv6)) {
+    if (! $isValidIp) {
         logger('someone tried to callback from an invalid IP');
         logger(' server ip: ' . $server->ipv4);
         logger(' server ipv6: ' . $server->ipv6);