Replace NEKit dependency with reduced subset
This commit is contained in:
relikd
389
GlassVPN/zhuhaow-NEKit/IPStack/DNS/DNSMessage.swift
Executable file
389
GlassVPN/zhuhaow-NEKit/IPStack/DNS/DNSMessage.swift
Executable file
@@ -0,0 +1,389 @@
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import Foundation
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open class DNSMessage {
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// var sourceAddress: IPv4Address?
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// var sourcePort: Port?
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// var destinationAddress: IPv4Address?
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// var destinationPort: Port?
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open var transactionID: UInt16 = 0
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open var messageType: DNSMessageType = .query
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open var authoritative: Bool = false
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open var truncation: Bool = false
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open var recursionDesired: Bool = false
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open var recursionAvailable: Bool = false
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open var status: DNSReturnStatus = .success
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open var queries: [DNSQuery] = []
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open var answers: [DNSResource] = []
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open var nameservers: [DNSResource] = []
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open var addtionals: [DNSResource] = []
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var payload: Data!
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var bytesLength: Int {
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var len = 12 + queries.reduce(0) {
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$0 + $1.bytesLength
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}
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len += answers.reduce(0) {
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$0 + $1.bytesLength
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}
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len += nameservers.reduce(0) {
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$0 + $1.bytesLength
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}
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len += addtionals.reduce(0) {
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$0 + $1.bytesLength
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}
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return len
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}
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var resolvedIPv4Address: IPAddress? {
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for answer in answers {
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if let address = answer.ipv4Address {
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return address
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}
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}
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return nil
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}
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var type: DNSType? {
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return queries.first?.type
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}
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init() {}
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init?(payload: Data) {
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self.payload = payload
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let scanner = BinaryDataScanner(data: payload, littleEndian: false)
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transactionID = scanner.read16()!
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var bytes = scanner.readByte()!
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if bytes & 0x80 > 0 {
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messageType = .response
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} else {
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messageType = .query
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}
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// ignore OP code
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authoritative = bytes & 0x04 > 0
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truncation = bytes & 0x02 > 0
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recursionDesired = bytes & 0x01 > 0
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bytes = scanner.readByte()!
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recursionAvailable = bytes & 0x80 > 0
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if let status = DNSReturnStatus(rawValue: bytes & 0x0F) {
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self.status = status
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} else {
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DDLogError("Received DNS response with unknown status: \(bytes & 0x0F).")
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self.status = .serverFailure
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}
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let queryCount = scanner.read16()!
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let answerCount = scanner.read16()!
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let nameserverCount = scanner.read16()!
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let addtionalCount = scanner.read16()!
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for _ in 0..<queryCount {
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queries.append(DNSQuery(payload: payload, offset: scanner.position, base: 0)!)
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scanner.advance(by: queries.last!.bytesLength)
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}
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for _ in 0..<answerCount {
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answers.append(DNSResource(payload: payload, offset: scanner.position, base: 0)!)
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scanner.advance(by: answers.last!.bytesLength)
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}
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for _ in 0..<nameserverCount {
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nameservers.append(DNSResource(payload: payload, offset: scanner.position, base: 0)!)
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scanner.advance(by: nameservers.last!.bytesLength)
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}
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for _ in 0..<addtionalCount {
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addtionals.append(DNSResource(payload: payload, offset: scanner.position, base: 0)!)
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scanner.advance(by: addtionals.last!.bytesLength)
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}
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}
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func buildMessage() -> Bool {
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payload = Data(count: bytesLength)
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if transactionID == 0 {
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transactionID = UInt16(arc4random_uniform(UInt32(UInt16.max)))
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}
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setPayloadWithUInt16(transactionID, at: 0, swap: true)
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var byte: UInt8 = 0
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byte += messageType.rawValue << 7
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if authoritative {
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byte += 4
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}
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if truncation {
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byte += 2
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}
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if recursionDesired {
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byte += 1
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}
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setPayloadWithUInt8(byte, at: 2)
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byte = 0
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if recursionAvailable {
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byte += 128
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}
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byte += status.rawValue
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setPayloadWithUInt8(byte, at: 3)
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setPayloadWithUInt16(UInt16(queries.count), at: 4, swap: true)
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setPayloadWithUInt16(UInt16(answers.count), at: 6, swap: true)
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setPayloadWithUInt16(UInt16(nameservers.count), at: 8, swap: true)
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setPayloadWithUInt16(UInt16(addtionals.count), at: 10, swap: true)
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return writeAllRecordAt(12)
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}
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// swiftlint:disable variable_name
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func setPayloadWithUInt8(_ value: UInt8, at: Int) {
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var v = value
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withUnsafeBytes(of: &v) {
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payload.replaceSubrange(at..<at+1, with: $0)
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}
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}
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func setPayloadWithUInt16(_ value: UInt16, at: Int, swap: Bool = false) {
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var v: UInt16
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if swap {
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v = NSSwapHostShortToBig(value)
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} else {
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v = value
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}
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withUnsafeBytes(of: &v) {
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payload.replaceSubrange(at..<at+2, with: $0)
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}
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}
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func setPayloadWithUInt32(_ value: UInt32, at: Int, swap: Bool = false) {
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var v: UInt32
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if swap {
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v = NSSwapHostIntToBig(value)
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} else {
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v = value
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}
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withUnsafeBytes(of: &v) {
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payload.replaceSubrange(at..<at+4, with: $0)
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}
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}
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func setPayloadWithData(_ data: Data, at: Int, length: Int? = nil, from: Int = 0) {
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let length = length ?? data.count - from
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payload.withUnsafeMutableBytes { ptr in
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data.copyBytes(to: ptr.baseAddress!.advanced(by: at).assumingMemoryBound(to: UInt8.self), from: from..<from+length)
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}
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}
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func resetPayloadAt(_ at: Int, length: Int) {
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payload.resetBytes(in: at..<at+length)
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}
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fileprivate func writeAllRecordAt(_ at: Int) -> Bool {
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var position = at
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for query in queries {
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guard writeDNSQuery(query, at: position) else {
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return false
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}
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position += query.bytesLength
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}
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for resources in [answers, nameservers, addtionals] {
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for resource in resources {
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guard writeDNSResource(resource, at: position) else {
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return false
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}
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position += resource.bytesLength
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}
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}
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return true
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}
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fileprivate func writeDNSQuery(_ query: DNSQuery, at: Int) -> Bool {
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guard DNSNameConverter.setName(query.name, toData: &payload!, at: at) else {
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return false
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}
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setPayloadWithUInt16(query.type.rawValue, at: at + query.nameBytesLength, swap: true)
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setPayloadWithUInt16(query.klass.rawValue, at: at + query.nameBytesLength + 2, swap: true)
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return true
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}
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fileprivate func writeDNSResource(_ resource: DNSResource, at: Int) -> Bool {
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guard DNSNameConverter.setName(resource.name, toData: &payload!, at: at) else {
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return false
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}
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setPayloadWithUInt16(resource.type.rawValue, at: at + resource.nameBytesLength, swap: true)
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setPayloadWithUInt16(resource.klass.rawValue, at: at + resource.nameBytesLength + 2, swap: true)
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setPayloadWithUInt32(resource.TTL, at: at + resource.nameBytesLength + 4, swap: true)
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setPayloadWithUInt16(resource.dataLength, at: at + resource.nameBytesLength + 8, swap: true)
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setPayloadWithData(resource.data, at: at + resource.nameBytesLength + 10)
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return true
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}
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}
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open class DNSQuery {
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public let name: String
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public let type: DNSType
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public let klass: DNSClass
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let nameBytesLength: Int
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init(name: String, type: DNSType = .a, klass: DNSClass = .internet) {
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self.name = name.trimmingCharacters(in: CharacterSet(charactersIn: "."))
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self.type = type
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self.klass = klass
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self.nameBytesLength = name.utf8.count + 2
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}
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init?(payload: Data, offset: Int, base: Int = 0) {
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(self.name, self.nameBytesLength) = DNSNameConverter.getNamefromData(payload, offset: offset, base: base)
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let scanner = BinaryDataScanner(data: payload, littleEndian: false)
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scanner.skip(to: offset + self.nameBytesLength)
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guard let type = DNSType(rawValue: scanner.read16()!) else {
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DDLogError("Received DNS packet with unknown type.")
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return nil
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}
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self.type = type
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guard let klass = DNSClass(rawValue: scanner.read16()!) else {
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DDLogError("Received DNS packet with unknown class.")
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return nil
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}
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self.klass = klass
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}
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var bytesLength: Int {
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return nameBytesLength + 4
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}
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}
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open class DNSResource {
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public let name: String
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public let type: DNSType
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public let klass: DNSClass
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public let TTL: UInt32
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let dataLength: UInt16
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public let data: Data
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let nameBytesLength: Int
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init(name: String, type: DNSType = .a, klass: DNSClass = .internet, TTL: UInt32 = 300, data: Data) {
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self.name = name
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self.type = type
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self.klass = klass
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self.TTL = TTL
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dataLength = UInt16(data.count)
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self.data = data
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self.nameBytesLength = name.utf8.count + 2
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}
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static func ARecord(_ name: String, TTL: UInt32 = 300, address: IPAddress) -> DNSResource {
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return DNSResource(name: name, type: .a, klass: .internet, TTL: TTL, data: address.dataInNetworkOrder)
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}
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init?(payload: Data, offset: Int, base: Int = 0) {
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(self.name, self.nameBytesLength) = DNSNameConverter.getNamefromData(payload, offset: offset, base: base)
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let scanner = BinaryDataScanner(data: payload, littleEndian: false)
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scanner.skip(to: offset + self.nameBytesLength)
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guard let type = DNSType(rawValue: scanner.read16()!) else {
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DDLogError("Received DNS packet with unknown type.")
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return nil
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}
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self.type = type
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guard let klass = DNSClass(rawValue: scanner.read16()!) else {
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DDLogError("Received DNS packet with unknown class.")
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return nil
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}
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self.klass = klass
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self.TTL = scanner.read32()!
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dataLength = scanner.read16()!
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self.data = payload.subdata(in: scanner.position..<scanner.position+Int(dataLength))
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}
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var bytesLength: Int {
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return nameBytesLength + 10 + Int(dataLength)
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}
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var ipv4Address: IPAddress? {
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guard type == .a else {
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return nil
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}
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return IPAddress(fromBytesInNetworkOrder: (data as NSData).bytes)
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}
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}
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class DNSNameConverter {
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static func setName(_ name: String, toData data: inout Data, at: Int) -> Bool {
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let labels = name.components(separatedBy: CharacterSet(charactersIn: "."))
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var position = at
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for label in labels {
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let len = label.utf8.count
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guard len != 0 else {
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// invalid domain name
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return false
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}
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data[position] = UInt8(len)
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position += 1
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data.replaceSubrange(position..<position+len, with: label.data(using: .utf8)!)
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position += len
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}
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data[position] = 0
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return true
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}
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static func getNamefromData(_ data: Data, offset: Int, base: Int = 0) -> (String, Int) {
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let scanner = BinaryDataScanner(data: data, littleEndian: false)
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scanner.skip(to: offset)
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var len: UInt8 = 0
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var name = ""
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var currentReadBytes = 0
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var jumped = false
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var nameBytesLength = 0
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repeat {
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let length = scanner.read16()!
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// is this a pointer?
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if length & 0xC000 == 0xC000 {
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if !jumped {
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// save the length position
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nameBytesLength = 2 + currentReadBytes
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jumped = true
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}
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scanner.skip(to: Int(length & 0x3FFF) + base)
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} else {
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scanner.advance(by: -2)
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}
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len = scanner.readByte()!
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currentReadBytes += 1
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if len == 0 {
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break
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}
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currentReadBytes += Int(len)
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guard let label = String(bytes: scanner.data.subdata(in: scanner.position..<scanner.position+Int(len)), encoding: .utf8) else {
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return ("", currentReadBytes)
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}
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// this is not efficient, but won't take much time, so maybe I'll optimize it later
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name = name.appendingFormat(".%@", label)
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scanner.advance(by: Int(len))
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} while true
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if !jumped {
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nameBytesLength = currentReadBytes
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}
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return (name.trimmingCharacters(in: CharacterSet(charactersIn: ".")), nameBytesLength)
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}
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}
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Reference in New Issue
Block a user