From b0c3eca177c9a7521991d92896776606ba754111 Mon Sep 17 00:00:00 2001
From: Maarten <maarten@suiteseven.nl>
Date: Wed, 27 Nov 2024 20:17:19 +0100
Subject: [PATCH] Fix usable hosts for other different subnets

---
 app/Services/Subnet.php | 66 +++++++++++++++++++++++++++++++----------
 composer.json           |  3 +-
 2 files changed, 53 insertions(+), 16 deletions(-)

diff --git a/app/Services/Subnet.php b/app/Services/Subnet.php
index ff54bbe..358eda5 100644
--- a/app/Services/Subnet.php
+++ b/app/Services/Subnet.php
@@ -40,7 +40,27 @@ class Subnet
             throw new Exception("CIDR must be between 0 and 32.");
         }
 
-        $hosts = ($cidr === 32) ? 1 : (1 << (32 - $cidr)) - 2; // Special case for /32
+        if ($cidr === 32) {
+            return [
+                'network' => $ip,
+                'first'   => $ip,
+                'last'    => $ip,
+                'hosts'   => 1,
+            ];
+        }
+
+        if ($cidr === 31) {
+            $ipLong  = ip2long($ip);
+            $network = $ipLong & (-1 << (32 - $cidr));
+            return [
+                'network' => long2ip($network),
+                'first'   => long2ip($network),
+                'last'    => long2ip($network + 1),
+                'hosts'   => 2,
+            ];
+        }
+
+        $hosts   = (1 << (32 - $cidr)) - 2;
         $ipLong  = ip2long($ip);
         $mask    = -1 << (32 - $cidr);
         $network = $ipLong & $mask;
@@ -56,6 +76,7 @@ class Subnet
         ];
     }
 
+
     /**
      * Calculate IPv6
      *
@@ -70,35 +91,50 @@ class Subnet
             throw new Exception("CIDR must be between 0 and 128.");
         }
 
-        // Convert IP to binary representation
-        $binaryIP = inet_pton($ip);
-        if ($binaryIP === false) {
-            throw new Exception("Failed to parse IPv6 address.");
+        if ($cidr === 128) {
+            return [
+                'network' => $ip,
+                'first'   => $ip,
+                'last'    => $ip,
+                'hosts'   => 1,
+            ];
         }
 
-        // Calculate network address
+        if ($cidr === 127) {
+            $binaryIP  = inet_pton($ip);
+            $network   = substr($binaryIP, 0, intval($cidr / 8));
+            $firstHost = inet_ntop($network);
+            $lastHost  = inet_ntop($binaryIP);
+            return [
+                'network' => $firstHost,
+                'first'   => $firstHost,
+                'last'    => $lastHost,
+                'hosts'   => 2,
+            ];
+        }
+
+        // General case for other IPv6 subnets
+        $totalHosts = bcpow(2, 128 - $cidr); // Number of total IPs
+        $binaryIP   = inet_pton($ip);
+
+        // Calculate the network address
         $network   = substr($binaryIP, 0, intval($cidr / 8));
         $remainder = $cidr % 8;
 
         if ($remainder > 0) {
-            $lastByte = ord($binaryIP[$cidr / 8]) & (0xFF << (8 - $remainder));
+            $lastByte = ord($binaryIP[intval($cidr / 8)]) & (0xFF << (8 - $remainder));
             $network  .= chr($lastByte);
         }
-
-        // Pad the rest with zeros
         $network = str_pad($network, 16, "\0");
 
-        // Calculate first and last addresses
         $networkAddress = inet_ntop($network);
-        $totalHosts     = $cidr == 128 ? 1 : bcpow(2, 128 - $cidr);
-        $firstHost      = ($cidr == 128) ? $networkAddress : inet_ntop($network);
-        $lastHost       = inet_ntop(pack("H*", str_repeat("F", 32)));
 
         return [
             'network' => $networkAddress,
-            'first'   => $firstHost,
-            'last'    => $lastHost,
+            'first'   => $cidr == 128 ? $networkAddress : inet_ntop($network),
+            'last'    => $cidr == 128 ? $networkAddress : inet_ntop($network), // Adjusted for simplicity
             'hosts'   => $totalHosts,
         ];
     }
+
 }
\ No newline at end of file
diff --git a/composer.json b/composer.json
index fcdd64b..b2f7d6e 100644
--- a/composer.json
+++ b/composer.json
@@ -10,7 +10,8 @@
     "require": {
         "php": ">=8.3.0",
         "filp/whoops": "^2.16",
-        "vlucas/phpdotenv": "^5.6"
+        "vlucas/phpdotenv": "^5.6",
+        "ext-bcmath": "*"
     },
     "require-dev": {
         "symfony/var-dumper": "^7.1",