95 lines
2.9 KiB
Swift
95 lines
2.9 KiB
Swift
//
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// DNSClient.swift
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// Tun
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//
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// Created by 安礼成 on 2025/12/10.
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//
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import Foundation
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import NIOCore
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import NIOPosix
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// 处理和sn-server服务器之间的通讯
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final class SDLDNSClient: ChannelInboundHandler {
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typealias InboundIn = AddressedEnvelope<ByteBuffer>
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private let group = MultiThreadedEventLoopGroup(numberOfThreads: 1)
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private var channel: Channel?
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private let logger: SDLLogger
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private let dnsServerAddress: SocketAddress
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public let packetFlow: AsyncStream<Data>
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private let packetContinuation: AsyncStream<Data>.Continuation
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// 启动函数
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init(dnsServerAddress: SocketAddress, logger: SDLLogger) async throws {
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self.dnsServerAddress = dnsServerAddress
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self.logger = logger
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(self.packetFlow, self.packetContinuation) = AsyncStream.makeStream(of: Data.self, bufferingPolicy: .unbounded)
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}
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func start() throws {
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let bootstrap = DatagramBootstrap(group: group)
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.channelOption(ChannelOptions.socketOption(.so_reuseaddr), value: 1)
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.channelInitializer { channel in
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channel.pipeline.addHandler(self)
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}
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self.channel = try bootstrap.bind(host: "0.0.0.0", port: 0).wait()
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self.logger.log("[DNSClient] started", level: .debug)
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}
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// --MARK: ChannelInboundHandler delegate
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func channelRead(context: ChannelHandlerContext, data: NIOAny) {
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let envelope = unwrapInboundIn(data)
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var buffer = envelope.data
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let remoteAddress = envelope.remoteAddress
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self.logger.log("[DNSClient] read data: \(buffer), from: \(remoteAddress)", level: .debug)
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let len = buffer.readableBytes
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if let bytes = buffer.readBytes(length: len) {
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self.packetContinuation.yield(Data(bytes))
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}
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}
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func channelInactive(context: ChannelHandlerContext) {
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self.packetContinuation.finish()
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}
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func forward(ipPacket: IPPacket) {
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guard let channel = self.channel else {
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return
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}
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let buffer = channel.allocator.buffer(bytes: ipPacket.data)
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let envelope = AddressedEnvelope<ByteBuffer>(remoteAddress: self.dnsServerAddress, data: buffer)
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channel.pipeline.eventLoop.execute {
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channel.writeAndFlush(envelope, promise: nil)
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}
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}
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deinit {
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try? self.group.syncShutdownGracefully()
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self.packetContinuation.finish()
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}
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}
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extension SDLDNSClient {
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struct Helper {
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static let dnsServer: String = "100.100.100.100"
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// dns请求包的目标地址
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static let dnsDestIpAddr: UInt32 = 1684300900
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// 判断是否是dns请求的数据包
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static func isDnsRequestPacket(ipPacket: IPPacket) -> Bool {
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return ipPacket.header.destination == dnsDestIpAddr
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}
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}
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}
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