feat: initial commit of Railtrack Pro prototype with complete test suite

2026-03-13 14:26:16 +00:00
commit 40500bb503
7790 changed files with 986332 additions and 0 deletions
@@ -0,0 +1,203 @@
+'use strict'
+
+const { Buffer } = require('node:buffer')
+const net = require('node:net')
+const { InvalidArgumentError } = require('./errors')
+
+/**
+ * Parse an address and determine its type
+ * @param {string} address - The address to parse
+ * @returns {{type: number, buffer: Buffer}} Address type and buffer
+ */
+function parseAddress (address) {
+  // Check if it's an IPv4 address
+  if (net.isIPv4(address)) {
+    const parts = address.split('.').map(Number)
+    return {
+      type: 0x01, // IPv4
+      buffer: Buffer.from(parts)
+    }
+  }
+
+  // Check if it's an IPv6 address
+  if (net.isIPv6(address)) {
+    return {
+      type: 0x04, // IPv6
+      buffer: parseIPv6(address)
+    }
+  }
+
+  // Otherwise, treat as domain name
+  const domainBuffer = Buffer.from(address, 'utf8')
+  if (domainBuffer.length > 255) {
+    throw new InvalidArgumentError('Domain name too long (max 255 bytes)')
+  }
+
+  return {
+    type: 0x03, // Domain
+    buffer: Buffer.concat([Buffer.from([domainBuffer.length]), domainBuffer])
+  }
+}
+
+/**
+ * Parse IPv6 address to buffer
+ * @param {string} address - IPv6 address string
+ * @returns {Buffer} 16-byte buffer
+ */
+function parseIPv6 (address) {
+  const buffer = Buffer.alloc(16)
+  const parts = address.split(':')
+  let partIndex = 0
+  let bufferIndex = 0
+
+  // Handle compressed notation (::)
+  const doubleColonIndex = address.indexOf('::')
+  if (doubleColonIndex !== -1) {
+    // Count non-empty parts
+    const nonEmptyParts = parts.filter(p => p.length > 0).length
+    const skipParts = 8 - nonEmptyParts
+
+    for (let i = 0; i < parts.length; i++) {
+      if (parts[i] === '' && i === doubleColonIndex / 3) {
+        // Skip empty parts for ::
+        bufferIndex += skipParts * 2
+      } else if (parts[i] !== '') {
+        const value = parseInt(parts[i], 16)
+        buffer.writeUInt16BE(value, bufferIndex)
+        bufferIndex += 2
+      }
+    }
+  } else {
+    // No compression, parse normally
+    for (const part of parts) {
+      if (part === '') continue
+      const value = parseInt(part, 16)
+      buffer.writeUInt16BE(value, partIndex * 2)
+      partIndex++
+    }
+  }
+
+  return buffer
+}
+
+/**
+ * Build a SOCKS5 address buffer
+ * @param {number} type - Address type (1=IPv4, 3=Domain, 4=IPv6)
+ * @param {Buffer} addressBuffer - The address data
+ * @param {number} port - Port number
+ * @returns {Buffer} Complete address buffer including type, address, and port
+ */
+function buildAddressBuffer (type, addressBuffer, port) {
+  const portBuffer = Buffer.allocUnsafe(2)
+  portBuffer.writeUInt16BE(port, 0)
+
+  return Buffer.concat([
+    Buffer.from([type]),
+    addressBuffer,
+    portBuffer
+  ])
+}
+
+/**
+ * Parse address from SOCKS5 response
+ * @param {Buffer} buffer - Buffer containing the address
+ * @param {number} offset - Starting offset in buffer
+ * @returns {{address: string, port: number, bytesRead: number}}
+ */
+function parseResponseAddress (buffer, offset = 0) {
+  if (buffer.length < offset + 1) {
+    throw new InvalidArgumentError('Buffer too small to contain address type')
+  }
+
+  const addressType = buffer[offset]
+  let address
+  let currentOffset = offset + 1
+
+  switch (addressType) {
+    case 0x01: { // IPv4
+      if (buffer.length < currentOffset + 6) {
+        throw new InvalidArgumentError('Buffer too small for IPv4 address')
+      }
+      address = Array.from(buffer.subarray(currentOffset, currentOffset + 4)).join('.')
+      currentOffset += 4
+      break
+    }
+
+    case 0x03: { // Domain
+      if (buffer.length < currentOffset + 1) {
+        throw new InvalidArgumentError('Buffer too small for domain length')
+      }
+      const domainLength = buffer[currentOffset]
+      currentOffset += 1
+
+      if (buffer.length < currentOffset + domainLength + 2) {
+        throw new InvalidArgumentError('Buffer too small for domain address')
+      }
+      address = buffer.subarray(currentOffset, currentOffset + domainLength).toString('utf8')
+      currentOffset += domainLength
+      break
+    }
+
+    case 0x04: { // IPv6
+      if (buffer.length < currentOffset + 18) {
+        throw new InvalidArgumentError('Buffer too small for IPv6 address')
+      }
+      // Convert buffer to IPv6 string
+      const parts = []
+      for (let i = 0; i < 8; i++) {
+        const value = buffer.readUInt16BE(currentOffset + i * 2)
+        parts.push(value.toString(16))
+      }
+      address = parts.join(':')
+      currentOffset += 16
+      break
+    }
+
+    default:
+      throw new InvalidArgumentError(`Invalid address type: ${addressType}`)
+  }
+
+  // Parse port
+  if (buffer.length < currentOffset + 2) {
+    throw new InvalidArgumentError('Buffer too small for port')
+  }
+  const port = buffer.readUInt16BE(currentOffset)
+  currentOffset += 2
+
+  return {
+    address,
+    port,
+    bytesRead: currentOffset - offset
+  }
+}
+
+/**
+ * Create error for SOCKS5 reply code
+ * @param {number} replyCode - SOCKS5 reply code
+ * @returns {Error} Appropriate error object
+ */
+function createReplyError (replyCode) {
+  const messages = {
+    0x01: 'General SOCKS server failure',
+    0x02: 'Connection not allowed by ruleset',
+    0x03: 'Network unreachable',
+    0x04: 'Host unreachable',
+    0x05: 'Connection refused',
+    0x06: 'TTL expired',
+    0x07: 'Command not supported',
+    0x08: 'Address type not supported'
+  }
+
+  const message = messages[replyCode] || `Unknown SOCKS5 error code: ${replyCode}`
+  const error = new Error(message)
+  error.code = `SOCKS5_${replyCode}`
+  return error
+}
+
+module.exports = {
+  parseAddress,
+  parseIPv6,
+  buildAddressBuffer,
+  parseResponseAddress,
+  createReplyError
+}