89 lines
2.5 KiB
Swift
89 lines
2.5 KiB
Swift
//
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// IPPacket.swift
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// Tun
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//
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// Created by 安礼成 on 2024/1/18.
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//
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import Foundation
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struct IPHeader {
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let version: UInt8
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let headerLength: UInt8
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let typeOfService: UInt8
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let totalLength: UInt16
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let id: UInt16
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let offset: UInt16
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let timeToLive: UInt8
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let proto: UInt8
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let checksum: UInt16
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let source: UInt32
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let destination: UInt32
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var source_ip: String {
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return SDLUtil.int32ToIp(source)
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}
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var destination_ip: String {
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return SDLUtil.int32ToIp(destination)
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}
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public var description: String {
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"""
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IPHeader version: \(version), header length: \(headerLength), type of service: \(typeOfService), total length: \(totalLength),
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id: \(id), offset: \(offset), time ot live: \(timeToLive), proto: \(proto), checksum: \(checksum), source ip: \(source_ip), destination ip:\(destination_ip)
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"""
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}
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}
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enum IPVersion: UInt8 {
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case ipv4 = 4
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case ipv6 = 6
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}
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enum TransportProtocol: UInt8 {
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case icmp = 1
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case tcp = 6
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case udp = 17
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}
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struct IPPacket {
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let header: IPHeader
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let data: Data
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init?(_ data: Data) {
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guard data.count >= 20 else {
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return nil
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}
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self.header = IPHeader(version: data[0] >> 4,
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headerLength: (data[0] & 0b1111) * 4,
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typeOfService: data[1],
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totalLength: UInt16(bytes: (data[2], data[3])),
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id: UInt16(bytes: (data[4], data[5])),
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offset: 1,
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timeToLive: data[8],
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proto: data[9],
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checksum: UInt16(bytes: (data[10], data[11])),
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source: UInt32(bytes: (data[12], data[13], data[14], data[15])),
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destination: UInt32(bytes: (data[16], data[17], data[18], data[19])))
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self.data = data
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}
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// 获取负载部分
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func getPayload() -> Data {
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return data.subdata(in: 20..<data.count)
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}
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// 获取ip数据包里面目标端口
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func getDstPort() -> UInt16? {
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guard case .ipv4 = IPVersion(rawValue: self.header.version), self.data.count >= 24 else {
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return nil
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}
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// 系统只会读取到ipv4的数据包，(srcPort:16, dstPort:16, ...)
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return UInt16(bytes: (self.data[22], self.data[23]))
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}
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}
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