i exist and i must consume

This commit is contained in:
2026-08-15 21:07:44 -04:00
commit a1373e720e
4 changed files with 717 additions and 0 deletions

459
MMDBWriter.php Normal file
View File

@@ -0,0 +1,459 @@
<?php
/**
* MMDBWriter - a pure-PHP library for generating MaxMind DB (.mmdb) files.
*
* Implements the MaxMind DB binary format from scratch:
* https://maxmind.github.io/MaxMind-DB/
*
* Supports IPv4 and IPv6 (dual-stack) databases, arbitrary nested
* map/array data structures, and all MMDB scalar types.
*
* Usage:
* $w = new MMDBWriter(6, 'GeoIP-Custom', ['en']);
* $w->addRecord('1.2.3.0/24', ['country' => 'US', 'city' => 'Ashburn']);
* $w->addRecord('2001:db8::/32', ['country' => 'DE']);
* $w->write('/path/to/out.mmdb');
*/
// ---------------------------------------------------------------------
// Explicit value typing (use when auto-detection of PHP types isn't
// precise enough, e.g. you need a uint16 instead of the default uint32).
// ---------------------------------------------------------------------
final class MMDBType
{
const POINTER = 1;
const STRING = 2;
const DOUBLE = 3;
const BYTES = 4;
const UINT16 = 5;
const UINT32 = 6;
const MAP = 7;
const INT32 = 8;
const UINT64 = 9;
const UINT128 = 10;
const ARRAY_T = 11;
const BOOLEAN = 14;
const FLOAT = 15;
}
final class MMDBValue
{
public $type;
public $value;
private function __construct(int $type, $value)
{
$this->type = $type;
$this->value = $value;
}
public static function string(string $v): self { return new self(MMDBType::STRING, $v); }
public static function bytes(string $v): self { return new self(MMDBType::BYTES, $v); }
public static function double(float $v): self { return new self(MMDBType::DOUBLE, $v); }
public static function float(float $v): self { return new self(MMDBType::FLOAT, $v); }
public static function uint16(int $v): self { return new self(MMDBType::UINT16, $v); }
public static function uint32(int $v): self { return new self(MMDBType::UINT32, $v); }
public static function uint64(int $v): self { return new self(MMDBType::UINT64, $v); }
// $v may be a PHP int (<= 64 bit) or a hex string like "0x1ff...".
public static function uint128($v): self { return new self(MMDBType::UINT128, $v); }
public static function int32(int $v): self { return new self(MMDBType::INT32, $v); }
public static function bool(bool $v): self { return new self(MMDBType::BOOLEAN, $v); }
public static function map(array $v): self { return new self(MMDBType::MAP, $v); }
public static function arr(array $v): self { return new self(MMDBType::ARRAY_T, $v); }
}
// ---------------------------------------------------------------------
// Binary encoder for the MaxMind DB "data format"
// ---------------------------------------------------------------------
final class MMDBEncoder
{
/** Encode any supported PHP value (or MMDBValue wrapper) to raw bytes. */
public static function encode($value): string
{
if ($value instanceof MMDBValue) {
return self::encodeTyped($value->type, $value->value);
}
if (is_bool($value)) {
return self::encodeTyped(MMDBType::BOOLEAN, $value);
}
if (is_int($value)) {
if ($value >= 0 && $value <= 0xFFFFFFFF) {
return self::encodeTyped(MMDBType::UINT32, $value);
}
if ($value < 0 && $value >= -2147483648) {
return self::encodeTyped(MMDBType::INT32, $value);
}
return self::encodeTyped(MMDBType::UINT64, $value);
}
if (is_float($value)) {
return self::encodeTyped(MMDBType::DOUBLE, $value);
}
if (is_string($value)) {
return self::encodeTyped(MMDBType::STRING, $value);
}
if (is_array($value)) {
if (self::isList($value)) {
return self::encodeTyped(MMDBType::ARRAY_T, $value);
}
return self::encodeTyped(MMDBType::MAP, $value);
}
throw new InvalidArgumentException('Unsupported value type: ' . gettype($value));
}
private static function isList(array $a): bool
{
$i = 0;
foreach ($a as $k => $_) {
if ($k !== $i++) {
return false;
}
}
return true;
}
private static function encodeTyped(int $type, $value): string
{
switch ($type) {
case MMDBType::STRING:
$payload = $value;
return self::controlAndSize($type, strlen($payload)) . $payload;
case MMDBType::BYTES:
$payload = $value;
return self::controlAndSize($type, strlen($payload)) . $payload;
case MMDBType::DOUBLE:
$payload = pack('E', $value); // 8-byte big-endian double
return self::controlAndSize($type, 8) . $payload;
case MMDBType::FLOAT:
$payload = pack('G', $value); // 4-byte big-endian float
return self::controlAndSize($type, 4) . $payload;
case MMDBType::UINT16:
$payload = pack('n', $value & 0xFFFF);
return self::controlAndSize($type, 2) . $payload;
case MMDBType::UINT32:
$payload = pack('N', $value & 0xFFFFFFFF);
return self::controlAndSize($type, 4) . $payload;
case MMDBType::INT32:
$payload = pack('N', $value & 0xFFFFFFFF);
return self::controlAndSize($type, 4) . $payload;
case MMDBType::UINT64:
$payload = pack('J', $value); // 8-byte big-endian uint64
return self::controlAndSize($type, 8) . $payload;
case MMDBType::UINT128:
$payload = self::to16Bytes($value);
return self::controlAndSize($type, 16) . $payload;
case MMDBType::BOOLEAN:
// Boolean has no payload; the value lives in the size field.
return self::controlAndSize($type, $value ? 1 : 0);
case MMDBType::MAP:
$out = self::controlAndSize($type, count($value));
foreach ($value as $k => $v) {
$out .= self::encodeTyped(MMDBType::STRING, (string) $k);
$out .= self::encode($v);
}
return $out;
case MMDBType::ARRAY_T:
$out = self::controlAndSize($type, count($value));
foreach ($value as $v) {
$out .= self::encode($v);
}
return $out;
default:
throw new InvalidArgumentException("Unsupported MMDB type: $type");
}
}
private static function to16Bytes($value): string
{
if (is_string($value) && preg_match('/^0x[0-9a-fA-F]+$/', $value)) {
$hex = str_pad(substr($value, 2), 32, '0', STR_PAD_LEFT);
return hex2bin($hex);
}
// Treat as a (<=64-bit) PHP int, zero-padded to 128 bits.
return str_repeat("\x00", 8) . pack('J', (int) $value);
}
/**
* Build the control byte (+ extra size bytes, + extended-type byte)
* for a given MMDB type and payload size, per the spec's control
* byte format.
*/
private static function controlAndSize(int $type, int $size): string
{
$typeBits = $type <= 7 ? $type : 0; // 0 = "look at next byte for real type"
$out = '';
if ($size < 29) {
$out .= chr(($typeBits << 5) | $size);
} elseif ($size < 285) {
$out .= chr(($typeBits << 5) | 29);
$out .= chr($size - 29);
} elseif ($size < 65821) {
$out .= chr(($typeBits << 5) | 30);
$out .= substr(pack('N', $size - 285), 2, 2); // 2-byte BE
} else {
$out .= chr(($typeBits << 5) | 31);
$out .= substr(pack('N', $size - 65821), 1, 3); // 3-byte BE
}
if ($type > 7) {
$out .= chr($type - 7); // extended type byte
}
return $out;
}
}
// ---------------------------------------------------------------------
// Binary trie used to build the MMDB search tree
// ---------------------------------------------------------------------
final class MMDBTree
{
/** @var array<int, array{0:mixed,1:mixed}> node index => [left, right] */
private $nodes = [[null, null]];
public function nodeCount(): int
{
return count($this->nodes);
}
/**
* @param int[] $bits 0/1 array, the path from the root
* @param int $prefixLen how many bits of $bits to actually use
* @param int $dataOffset byte offset of this record's value in the data section
*/
public function insert(array $bits, int $prefixLen, int $dataOffset): void
{
$current = 0;
for ($i = 0; $i < $prefixLen; $i++) {
$bit = $bits[$i];
$isLast = ($i === $prefixLen - 1);
$rec = $this->nodes[$current][$bit];
if ($isLast) {
$this->nodes[$current][$bit] = ['data' => $dataOffset];
continue;
}
if ($rec === null) {
$newIdx = count($this->nodes);
$this->nodes[] = [null, null];
$this->nodes[$current][$bit] = $newIdx;
$current = $newIdx;
} elseif (is_array($rec)) {
// A less-specific network already terminates here; split it
// so both children inherit its data, then keep descending.
$newIdx = count($this->nodes);
$this->nodes[] = [$rec, $rec];
$this->nodes[$current][$bit] = $newIdx;
$current = $newIdx;
} else {
$current = $rec;
}
}
}
/**
* Serialize the tree to bytes using the smallest record size (24, 28,
* or 32 bits) that fits every record value.
*
* @return array{0:string,1:int} [tree bytes, record size used]
*/
public function serialize(int $dataSectionLength): array
{
$nodeCount = count($this->nodes);
$maxDataPointer = $dataSectionLength + $nodeCount + 16;
$maxValue = max($nodeCount, $maxDataPointer);
if ($maxValue <= 0xFFFFFF) {
$recordSize = 24;
} elseif ($maxValue <= 0xFFFFFFF) {
$recordSize = 28;
} elseif ($maxValue <= 0xFFFFFFFF) {
$recordSize = 32;
} else {
throw new RuntimeException('Database too large for a 32-bit record size.');
}
$out = '';
foreach ($this->nodes as $node) {
$left = $this->recordValue($node[0], $nodeCount);
$right = $this->recordValue($node[1], $nodeCount);
$out .= $this->packPair($left, $right, $recordSize);
}
return [$out, $recordSize];
}
private function recordValue($rec, int $nodeCount): int
{
if ($rec === null) {
return $nodeCount; // "not found" sentinel
}
if (is_array($rec)) {
return $rec['data'] + $nodeCount + 16;
}
return $rec; // pointer to another node
}
private function packPair(int $left, int $right, int $recordSize): string
{
if ($recordSize === 24) {
return substr(pack('N', $left), 1, 3) . substr(pack('N', $right), 1, 3);
}
if ($recordSize === 32) {
return pack('N', $left) . pack('N', $right);
}
// 28-bit: 7 bytes total, per the MMDB spec's packing scheme.
$b0 = ($left >> 20) & 0xFF;
$b1 = ($left >> 12) & 0xFF;
$b2 = ($left >> 4) & 0xFF;
$b3 = (($left & 0xF) << 4) | (($right >> 24) & 0xF);
$b4 = ($right >> 16) & 0xFF;
$b5 = ($right >> 8) & 0xFF;
$b6 = $right & 0xFF;
return chr($b0) . chr($b1) . chr($b2) . chr($b3) . chr($b4) . chr($b5) . chr($b6);
}
}
// ---------------------------------------------------------------------
// Top-level writer: ties the tree, data section and metadata together
// ---------------------------------------------------------------------
final class MMDBWriter
{
private $ipVersion;
private $totalDepth;
private $tree;
private $dataSection = '';
private $dataCache = [];
private $databaseType;
private $languages;
private $description;
/**
* @param int $ipVersion 4 (IPv4-only tree) or 6 (dual-stack tree)
* @param string $databaseType free-form name, e.g. "GeoIP-Custom"
* @param string[] $languages language codes present in $description
* @param array $description language code => human description
*/
public function __construct(
int $ipVersion = 6,
string $databaseType = 'Custom',
array $languages = ['en'],
array $description = ['en' => 'Custom MMDB database']
) {
if ($ipVersion !== 4 && $ipVersion !== 6) {
throw new InvalidArgumentException('ipVersion must be 4 or 6');
}
$this->ipVersion = $ipVersion;
$this->totalDepth = $ipVersion === 4 ? 32 : 128;
$this->tree = new MMDBTree();
$this->databaseType = $databaseType;
$this->languages = $languages;
$this->description = $description;
}
/**
* @param string $cidr e.g. "1.2.3.0/24", "2001:db8::/32", or a bare IP
* @param mixed $data scalar/array/MMDBValue data to associate with the network
*/
public function addRecord(string $cidr, $data): void
{
[$ip, $prefixLen] = $this->parseCidr($cidr);
[$bits, $treePrefixLen] = $this->ipToTreeBits($ip, $prefixLen);
$offset = $this->internData($data);
$this->tree->insert($bits, $treePrefixLen, $offset);
}
public function write(string $path): void
{
[$treeBytes, $recordSize] = $this->tree->serialize(strlen($this->dataSection));
$metadata = [
'node_count' => MMDBValue::uint32($this->tree->nodeCount()),
'record_size' => MMDBValue::uint16($recordSize),
'ip_version' => MMDBValue::uint16($this->ipVersion),
'database_type' => MMDBValue::string($this->databaseType),
'languages' => array_values($this->languages),
'binary_format_major_version' => MMDBValue::uint16(2),
'binary_format_minor_version' => MMDBValue::uint16(0),
'build_epoch' => MMDBValue::uint64(time()),
'description' => $this->description,
];
$metadataBytes = MMDBEncoder::encode(MMDBValue::map($metadata));
$separator = str_repeat("\x00", 16);
$marker = "\xAB\xCD\xEFMaxMind.com";
$blob = $treeBytes . $separator . $this->dataSection . $marker . $metadataBytes;
if (file_put_contents($path, $blob) === false) {
throw new RuntimeException("Failed to write $path");
}
}
private function internData($data): int
{
$key = serialize($data);
if (isset($this->dataCache[$key])) {
return $this->dataCache[$key];
}
$offset = strlen($this->dataSection);
$this->dataSection .= MMDBEncoder::encode($data);
$this->dataCache[$key] = $offset;
return $offset;
}
private function parseCidr(string $cidr): array
{
if (strpos($cidr, '/') !== false) {
[$ip, $prefix] = explode('/', $cidr, 2);
return [$ip, (int) $prefix];
}
$isV4 = strpos($cidr, ':') === false;
return [$cidr, $isV4 ? 32 : 128];
}
private function ipToTreeBits(string $ip, int $prefixLen): array
{
$packed = @inet_pton($ip);
if ($packed === false) {
throw new InvalidArgumentException("Invalid IP address: $ip");
}
$isV4 = strlen($packed) === 4;
if ($isV4 && $this->totalDepth === 128) {
// Embed IPv4 networks under ::/96, as MaxMind's own dual-stack
// databases do.
$prefix = array_fill(0, 96, 0);
$treePrefixLen = 96 + $prefixLen;
} else {
$prefix = [];
$treePrefixLen = $prefixLen;
}
$bits = $prefix;
foreach (str_split($packed) as $byte) {
$b = ord($byte);
for ($i = 7; $i >= 0; $i--) {
$bits[] = ($b >> $i) & 1;
}
}
return [$bits, $treePrefixLen];
}
}