From a37f48fdd6d0fd00d722ef29f3a0ad3b2dfbe826 Mon Sep 17 00:00:00 2001
From: flashwave <me@flash.moe>
Date: Sat, 22 Dec 2018 18:03:58 +0100
Subject: [PATCH] //cidr stuff

---
 misuzu.php       |  1 -
 public/index.php | 53 ++++++++++++++++++++++++++++++++---------
 src/Net/cidr.php |  5 ----
 src/Net/ip.php   | 61 ++++++++++++++++++++++++++++++++++++++++++++++--
 utility.php      | 11 +++++++++
 5 files changed, 112 insertions(+), 19 deletions(-)
 delete mode 100644 src/Net/cidr.php

diff --git a/misuzu.php b/misuzu.php
index 7834c535..ebfa5e58 100644
--- a/misuzu.php
+++ b/misuzu.php
@@ -51,7 +51,6 @@ require_once 'src/Forum/perms.php';
 require_once 'src/Forum/post.php';
 require_once 'src/Forum/topic.php';
 require_once 'src/Forum/validate.php';
-require_once 'src/Net/cidr.php';
 require_once 'src/Net/geoip.php';
 require_once 'src/Net/ip.php';
 require_once 'src/Parsers/parse.php';
diff --git a/public/index.php b/public/index.php
index 3a7d285d..e6bbc42a 100644
--- a/public/index.php
+++ b/public/index.php
@@ -1,22 +1,53 @@
 <?php
 require_once '../misuzu.php';
 
-if (!empty($_GET['pdump'])) {
-    header('Content-Type: text/plain');
+if (MSZ_DEBUG) {
+    if (!empty($_GET['pdump'])) {
+        header('Content-Type: text/plain');
 
-    for ($i = 0; $i < 10; $i++) {
-        $perms = [];
+        for ($i = 0; $i < 10; $i++) {
+            $perms = [];
 
-        echo "# USER {$i}\n";
+            echo "# USER {$i}\n";
 
-        foreach (MSZ_PERM_MODES as $mode) {
-            $perms = decbin(perms_get_user($mode, $i));
-            echo "{$mode}: {$perms}\n";
+            foreach (MSZ_PERM_MODES as $mode) {
+                $perms = decbin(perms_get_user($mode, $i));
+                echo "{$mode}: {$perms}\n";
+            }
+
+            echo "\n";
         }
-
-        echo "\n";
+        return;
+    }
+
+    if (!empty($_GET['cidr'])) {
+        header('Content-Type: text/plain');
+
+        $checks = [
+            [
+                'cidr' => '104.16.0.0/12',
+                'addrs' => [
+                    '104.28.8.4',
+                    '104.28.9.4',
+                    '94.211.73.13',
+                ],
+            ],
+        ];
+
+        foreach ($checks as $check) {
+            $mask = ip_cidr_to_mask($check['cidr']);
+
+            echo 'MASK> ' .  inet_ntop($mask) . "\t" . decbin_str($mask) . PHP_EOL;
+
+            foreach ($check['addrs'] as $addr) {
+                $addr = inet_pton($addr);
+                echo 'ADDR> ' . inet_ntop($addr) . "\t" . decbin_str($addr) . "\t" . ip_match_mask($addr, $mask) . PHP_EOL;
+            }
+
+            echo PHP_EOL;
+        }
+        return;
     }
-    return;
 }
 
 if (config_get_default(false, 'Site', 'embed_linked_data')) {
diff --git a/src/Net/cidr.php b/src/Net/cidr.php
deleted file mode 100644
index f2550f06..00000000
--- a/src/Net/cidr.php
+++ /dev/null
@@ -1,5 +0,0 @@
-<?php
-function cidr_range_to_mask(string $startAddress, string $endAddress, bool $isRaw = false): array
-{
-    return [];
-}
diff --git a/src/Net/ip.php b/src/Net/ip.php
index b480eceb..bccc2f44 100644
--- a/src/Net/ip.php
+++ b/src/Net/ip.php
@@ -40,15 +40,72 @@ function ip_detect_string_version(string $address): int
     return MSZ_IP_UNKNOWN;
 }
 
-function ip_detect_raw_version(string $raw): int
+function ip_detect_raw_version(string $raw, bool $returnWidth = false): int
 {
     $rawLength = strlen($raw);
 
     foreach (MSZ_IP_SIZES as $version => $length) {
         if ($rawLength === $length) {
-            return $version;
+            return $returnWidth ? $length : $version;
         }
     }
 
     return MSZ_IP_UNKNOWN;
 }
+
+function ip_get_raw_width(int $version): int
+{
+    return MSZ_IP_SIZES[$version] ?? 0;
+}
+
+// Takes 1.2.3.4/n notation, returns subnet mask in raw bytes
+function ip_cidr_to_mask(string $ipRange): string
+{
+    [$address, $bits] = explode('/', $ipRange, 2);
+
+    $address = inet_pton($address);
+    $width = ip_detect_raw_version($address, true) * 8;
+
+    if ($bits < 1 || $bits > $width) {
+        return str_repeat(chr(0), $width);
+    }
+
+    $mask = '';
+
+    for ($i = 0; $i < floor($width / 8); $i++) {
+        $addressByte = ord($address[$i]);
+        $maskByte = 0;
+
+        for ($j = 0; $j < 8; $j++) {
+            $offset = (8 * $i) + $j;
+            $bit = 0x80 >> $j;
+
+            if ($offset < $bits && ($addressByte & $bit) > 0) {
+                $maskByte |= $bit;
+            } else {
+                $maskByte &= ~$bit;
+            }
+        }
+
+        $mask .= chr($maskByte);
+    }
+
+    return $mask;
+}
+
+// Takes a RAW IP and a RAW MASK
+function ip_match_mask(string $ipAddress, string $mask): int
+{
+    $width = strlen($mask);
+    $result = false;
+
+    if (strlen($ipAddress) !== $width) {
+        return $result;
+    }
+
+    for ($i = 0; $i < $width; $i++) {
+        $result &= ($ipAddress[$i] & ~$mask[$i]) === 0;
+    }
+
+    return $result;
+}
diff --git a/utility.php b/utility.php
index caf29b6d..841b39b0 100644
--- a/utility.php
+++ b/utility.php
@@ -342,3 +342,14 @@ function is_user_int($value): bool
 {
     return ctype_digit(strval($value));
 }
+
+function decbin_str(string $str): string
+{
+    $out = '';
+
+    for ($i = 0; $i < strlen($str); $i++) {
+        $out .= str_pad(decbin(ord($str[$i])), 8, '0');
+    }
+
+    return $out;
+}