100 lines
2.5 KiB
Swift
100 lines
2.5 KiB
Swift
//
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// LayerPacket.swift
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// Tun
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//
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// Created by 安礼成 on 2024/8/21.
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//
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import Foundation
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import zlib
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struct LayerPacket {
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// 数据包类型
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enum PacketType: UInt16 {
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case arp = 0x0806
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case ipv4 = 0x0800
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case ipv6 = 0x86DD
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case taggedFrame = 0x8100
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}
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enum LayerPacketError: Error {
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case invalidLength
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case invaldPacketType
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}
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struct MacAddress {
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let data: Data
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init(data: Data) {
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self.data = data
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}
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func isBroadcast() -> Bool {
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return data.count == 6 && self.data.allSatisfy { $0 == 0xFF}
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}
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func isMulticast() -> Bool {
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return data.count == 6 && (data[0] == 0x01 && data[1] == 0x00 && data[2] == 0x5E)
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}
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func format() -> String {
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// 将mac地址转换成字符串
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let bytes = [UInt8](data)
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return bytes.map { String(format: "%02X", $0) }.joined(separator: ":").lowercased()
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}
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static func description(data: Data) -> String {
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// 将mac地址转换成字符串
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let bytes = [UInt8](data)
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return bytes.map { String(format: "%02X", $0) }.joined(separator: ":").lowercased()
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}
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}
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let dstMac: Data
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let srcMac: Data
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let type: PacketType
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let data: Data
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init(dstMac: Data, srcMac: Data, type: PacketType, data: Data) {
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self.dstMac = dstMac
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self.srcMac = srcMac
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self.type = type
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self.data = data
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}
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init(layerData playload: Data) throws {
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guard playload.count >= 14 else {
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throw LayerPacketError.invalidLength
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}
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self.dstMac = Data(playload[0..<6])
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self.srcMac = Data(playload[6..<12])
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guard let type = PacketType(rawValue: UInt16(bytes: (playload[12], playload[13]))) else {
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throw LayerPacketError.invaldPacketType
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}
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self.type = type
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self.data = Data(playload[14...])
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}
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func marshal() -> Data {
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var packet = Data()
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packet.append(dstMac)
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packet.append(srcMac)
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packet.append(self.type.rawValue.data())
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packet.append(self.data)
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return packet
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}
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private static func crc32(data: Data) -> UInt32 {
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let crc = data.withUnsafeBytes { buffer in
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return zlib.crc32(0, buffer.bindMemory(to: UInt8.self).baseAddress, uInt(buffer.count))
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}
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return UInt32(crc)
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}
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}
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