mirror of
https://github.com/apple/swift-nio-extras.git
synced 2025-05-14 00:42:41 +08:00
dabef818d3
Motivation: An index page ties all the other documentation together Modifications: Add index pages for the library targets. Correct a few minor errors in the main docs. Result: A more joined up documentation experience.
725 lines
33 KiB
Swift
725 lines
33 KiB
Swift
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This source file is part of the SwiftNIO open source project
|
|
//
|
|
// Copyright (c) 2019-2021 Apple Inc. and the SwiftNIO project authors
|
|
// Licensed under Apache License v2.0
|
|
//
|
|
// See LICENSE.txt for license information
|
|
// See CONTRIBUTORS.txt for the list of SwiftNIO project authors
|
|
//
|
|
// SPDX-License-Identifier: Apache-2.0
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#if os(macOS) || os(tvOS) || os(iOS) || os(watchOS)
|
|
import Darwin
|
|
#else
|
|
import Glibc
|
|
#endif
|
|
import Dispatch
|
|
|
|
import NIOCore
|
|
|
|
let sysWrite = write
|
|
|
|
struct TCPHeader {
|
|
struct Flags: OptionSet {
|
|
var rawValue: UInt8
|
|
|
|
init(rawValue: UInt8) {
|
|
self.rawValue = rawValue
|
|
}
|
|
|
|
static let fin = Flags(rawValue: 1 << 0)
|
|
static let syn = Flags(rawValue: 1 << 1)
|
|
static let rst = Flags(rawValue: 1 << 2)
|
|
static let psh = Flags(rawValue: 1 << 3)
|
|
static let ack = Flags(rawValue: 1 << 4)
|
|
static let urg = Flags(rawValue: 1 << 5)
|
|
static let ece = Flags(rawValue: 1 << 6)
|
|
static let cwr = Flags(rawValue: 1 << 7)
|
|
}
|
|
|
|
var flags: Flags
|
|
var ackNumber: UInt32?
|
|
var sequenceNumber: UInt32
|
|
var srcPort: UInt16
|
|
var dstPort: UInt16
|
|
}
|
|
|
|
struct PCAPRecordHeader {
|
|
enum Error: Swift.Error {
|
|
case incompatibleAddressPair(SocketAddress, SocketAddress)
|
|
}
|
|
enum AddressTuple {
|
|
case v4(src: SocketAddress.IPv4Address, dst: SocketAddress.IPv4Address)
|
|
case v6(src: SocketAddress.IPv6Address, dst: SocketAddress.IPv6Address)
|
|
|
|
var srcPort: UInt16 {
|
|
switch self {
|
|
case .v4(src: let src, dst: _):
|
|
return UInt16(bigEndian: src.address.sin_port)
|
|
case .v6(src: let src, dst: _):
|
|
return UInt16(bigEndian: src.address.sin6_port)
|
|
}
|
|
}
|
|
|
|
var dstPort: UInt16 {
|
|
switch self {
|
|
case .v4(src: _, dst: let dst):
|
|
return UInt16(bigEndian: dst.address.sin_port)
|
|
case .v6(src: _, dst: let dst):
|
|
return UInt16(bigEndian: dst.address.sin6_port)
|
|
}
|
|
}
|
|
}
|
|
|
|
var payloadLength: Int
|
|
var addresses: AddressTuple
|
|
var time: timeval
|
|
var tcp: TCPHeader
|
|
|
|
init(payloadLength: Int, addresses: AddressTuple, time: timeval, tcp: TCPHeader) {
|
|
self.payloadLength = payloadLength
|
|
self.addresses = addresses
|
|
self.time = time
|
|
self.tcp = tcp
|
|
|
|
assert(addresses.srcPort == Int(tcp.srcPort))
|
|
assert(addresses.dstPort == Int(tcp.dstPort))
|
|
assert(tcp.ackNumber == nil ? !tcp.flags.contains([.ack]) : tcp.flags.contains([.ack]))
|
|
}
|
|
|
|
init(payloadLength: Int, src: SocketAddress, dst: SocketAddress, tcp: TCPHeader) throws {
|
|
let addressTuple: AddressTuple
|
|
switch (src, dst) {
|
|
case (.v4(let src), .v4(let dst)):
|
|
addressTuple = .v4(src: src, dst: dst)
|
|
case (.v6(let src), .v6(let dst)):
|
|
addressTuple = .v6(src: src, dst: dst)
|
|
default:
|
|
throw Error.incompatibleAddressPair(src, dst)
|
|
}
|
|
self = .init(payloadLength: payloadLength, addresses: addressTuple, tcp: tcp)
|
|
}
|
|
|
|
init(payloadLength: Int, addresses: AddressTuple, tcp: TCPHeader) {
|
|
var tv = timeval()
|
|
gettimeofday(&tv, nil)
|
|
self = .init(payloadLength: payloadLength, addresses: addresses, time: tv, tcp: tcp)
|
|
}
|
|
}
|
|
|
|
/// A `ChannelHandler` that can write a [`.pcap` file](https://en.wikipedia.org/wiki/Pcap) containing the send/received
|
|
/// data as synthesized TCP packet captures.
|
|
///
|
|
/// You will be able to open the `.pcap` file in for example [Wireshark](https://www.wireshark.org) or
|
|
/// [`tcpdump`](http://www.tcpdump.org). Using `NIOWritePCAPHandler` to write your `.pcap` files can be useful for
|
|
/// example when your real network traffic is TLS protected (so `tcpdump`/Wireshark can't read it directly), or if you
|
|
/// don't have enough privileges on the running host to dump the network traffic.
|
|
///
|
|
/// ``NIOWritePCAPHandler`` will also work with Unix Domain Sockets in which case it will still synthesize a TCP packet
|
|
/// capture with local address `111.111.111.111` (port `1111`) and remote address `222.222.222.222` (port `2222`).
|
|
public class NIOWritePCAPHandler: RemovableChannelHandler {
|
|
public enum Mode {
|
|
case client
|
|
case server
|
|
}
|
|
|
|
/// Settings for ``NIOWritePCAPHandler``.
|
|
public struct Settings {
|
|
/// When to issue data into the `.pcap` file.
|
|
public enum EmitPCAP {
|
|
/// Write the data immediately when ``NIOWritePCAPHandler`` saw the event on the `ChannelPipeline`.
|
|
///
|
|
/// For writes this means when the `write` event is triggered. Please note that this will write potentially
|
|
/// unflushed data into the `.pcap` file.
|
|
///
|
|
/// If in doubt, prefer ``whenCompleted``.
|
|
case whenIssued
|
|
|
|
/// Write the data when the event completed.
|
|
///
|
|
/// For writes this means when the `write` promise is succeeded. The ``whenCompleted`` mode mirrors most
|
|
/// closely what's actually sent over the wire.
|
|
case whenCompleted
|
|
}
|
|
|
|
/// When to emit the data from the `write` event into the `.pcap` file.
|
|
public var emitPCAPWrites: EmitPCAP
|
|
|
|
/// Default settings for the ``NIOWritePCAPHandler``.
|
|
public init() {
|
|
self = .init(emitPCAPWrites: .whenCompleted)
|
|
}
|
|
|
|
/// Settings with customization.
|
|
///
|
|
/// - parameters:
|
|
/// - emitPCAPWrites: When to issue the writes into the `.pcap` file, see ``EmitPCAP``.
|
|
public init(emitPCAPWrites: EmitPCAP) {
|
|
self.emitPCAPWrites = emitPCAPWrites
|
|
}
|
|
}
|
|
|
|
private enum CloseState {
|
|
case notClosing
|
|
case closedInitiatorLocal
|
|
case closedInitiatorRemote
|
|
}
|
|
|
|
private let fileSink: (ByteBuffer) -> Void
|
|
private let mode: Mode
|
|
private let maxPayloadSize = Int(UInt16.max - 40 /* needs to fit into the IPv4 header which adds 40 */)
|
|
private let settings: Settings
|
|
private var buffer: ByteBuffer!
|
|
private var readInboundBytes: UInt64 = 0
|
|
private var writtenOutboundBytes: UInt64 = 0
|
|
private var closeState = CloseState.notClosing
|
|
|
|
private static let fakeLocalAddress = try! SocketAddress(ipAddress: "111.111.111.111", port: 1111)
|
|
private static let fakeRemoteAddress = try! SocketAddress(ipAddress: "222.222.222.222", port: 2222)
|
|
|
|
private var localAddress: SocketAddress?
|
|
private var remoteAddress: SocketAddress?
|
|
|
|
/// Reusable header for `.pcap` file.
|
|
public static var pcapFileHeader: ByteBuffer {
|
|
var buffer = ByteBufferAllocator().buffer(capacity: 24)
|
|
buffer.writePCAPHeader()
|
|
return buffer
|
|
}
|
|
|
|
/// Initialize a ``NIOWritePCAPHandler``.
|
|
///
|
|
/// - parameters:
|
|
/// - fakeLocalAddress: Allows you to optionally override the local address to be different from the real one.
|
|
/// - fakeRemoteAddress: Allows you to optionally override the remote address to be different from the real one.
|
|
/// - settings: The settings for the ``NIOWritePCAPHandler``.
|
|
/// - fileSink: The `fileSink` closure is called every time a new chunk of the `.pcap` file is ready to be
|
|
/// written to disk or elsewhere. See ``SynchronizedFileSink`` for a convenient way to write to
|
|
/// disk.
|
|
public init(mode: Mode,
|
|
fakeLocalAddress: SocketAddress? = nil,
|
|
fakeRemoteAddress: SocketAddress? = nil,
|
|
settings: Settings,
|
|
fileSink: @escaping (ByteBuffer) -> Void) {
|
|
self.settings = settings
|
|
self.fileSink = fileSink
|
|
self.mode = mode
|
|
if let fakeLocalAddress = fakeLocalAddress {
|
|
self.localAddress = fakeLocalAddress
|
|
}
|
|
if let fakeRemoteAddress = fakeRemoteAddress {
|
|
self.remoteAddress = fakeRemoteAddress
|
|
}
|
|
}
|
|
|
|
/// Initialize a ``NIOWritePCAPHandler`` with default settings.
|
|
///
|
|
/// - parameters:
|
|
/// - fakeLocalAddress: Allows you to optionally override the local address to be different from the real one.
|
|
/// - fakeRemoteAddress: Allows you to optionally override the remote address to be different from the real one.
|
|
/// - fileSink: The `fileSink` closure is called every time a new chunk of the `.pcap` file is ready to be
|
|
/// written to disk or elsewhere. See `NIOSynchronizedFileSink` for a convenient way to write to
|
|
/// disk.
|
|
public convenience init(mode: Mode,
|
|
fakeLocalAddress: SocketAddress? = nil,
|
|
fakeRemoteAddress: SocketAddress? = nil,
|
|
fileSink: @escaping (ByteBuffer) -> Void) {
|
|
self.init(mode: mode,
|
|
fakeLocalAddress: fakeLocalAddress,
|
|
fakeRemoteAddress: fakeRemoteAddress,
|
|
settings: Settings(),
|
|
fileSink: fileSink)
|
|
}
|
|
|
|
private func writeBuffer(_ buffer: ByteBuffer) {
|
|
self.fileSink(buffer)
|
|
}
|
|
|
|
private func localAddress(context: ChannelHandlerContext) -> SocketAddress {
|
|
if let localAddress = self.localAddress {
|
|
return localAddress
|
|
} else {
|
|
let localAddress = context.channel.localAddress ?? NIOWritePCAPHandler.fakeLocalAddress
|
|
self.localAddress = localAddress
|
|
return localAddress
|
|
}
|
|
}
|
|
|
|
private func remoteAddress(context: ChannelHandlerContext) -> SocketAddress {
|
|
if let remoteAddress = self.remoteAddress {
|
|
return remoteAddress
|
|
} else {
|
|
let remoteAddress = context.channel.remoteAddress ?? NIOWritePCAPHandler.fakeRemoteAddress
|
|
self.remoteAddress = remoteAddress
|
|
return remoteAddress
|
|
}
|
|
}
|
|
|
|
private func clientAddress(context: ChannelHandlerContext) -> SocketAddress {
|
|
switch self.mode {
|
|
case .client:
|
|
return self.localAddress(context: context)
|
|
case .server:
|
|
return self.remoteAddress(context: context)
|
|
}
|
|
}
|
|
|
|
private func serverAddress(context: ChannelHandlerContext) -> SocketAddress {
|
|
switch self.mode {
|
|
case .client:
|
|
return self.remoteAddress(context: context)
|
|
case .server:
|
|
return self.localAddress(context: context)
|
|
}
|
|
}
|
|
|
|
private func takeSensiblySizedPayload(buffer: inout ByteBuffer) -> ByteBuffer? {
|
|
guard buffer.readableBytes > 0 else {
|
|
return nil
|
|
}
|
|
|
|
return buffer.readSlice(length: min(buffer.readableBytes, self.maxPayloadSize))
|
|
}
|
|
|
|
private func sequenceNumber(byteCount: UInt64) -> UInt32 {
|
|
return UInt32(byteCount % (UInt64(UInt32.max) + 1))
|
|
}
|
|
}
|
|
|
|
extension NIOWritePCAPHandler: ChannelDuplexHandler {
|
|
public typealias InboundIn = ByteBuffer
|
|
public typealias InboundOut = ByteBuffer
|
|
public typealias OutboundIn = IOData
|
|
public typealias OutboundOut = IOData
|
|
|
|
public func handlerAdded(context: ChannelHandlerContext) {
|
|
self.buffer = context.channel.allocator.buffer(capacity: 256)
|
|
}
|
|
|
|
public func channelActive(context: ChannelHandlerContext) {
|
|
self.buffer.clear()
|
|
self.readInboundBytes = 1
|
|
self.writtenOutboundBytes = 1
|
|
do {
|
|
let clientAddress = self.clientAddress(context: context)
|
|
let serverAddress = self.serverAddress(context: context)
|
|
try self.buffer.writePCAPRecord(.init(payloadLength: 0,
|
|
src: clientAddress,
|
|
dst: serverAddress,
|
|
tcp: TCPHeader(flags: [.syn],
|
|
ackNumber: nil,
|
|
sequenceNumber: 0,
|
|
srcPort: .init(clientAddress.port!),
|
|
dstPort: .init(serverAddress.port!))))
|
|
try self.buffer.writePCAPRecord(.init(payloadLength: 0,
|
|
src: serverAddress,
|
|
dst: clientAddress,
|
|
tcp: TCPHeader(flags: [.syn, .ack],
|
|
ackNumber: 1,
|
|
sequenceNumber: 0,
|
|
srcPort: .init(serverAddress.port!),
|
|
dstPort: .init(clientAddress.port!))))
|
|
try self.buffer.writePCAPRecord(.init(payloadLength: 0,
|
|
src: clientAddress,
|
|
dst: serverAddress,
|
|
tcp: TCPHeader(flags: [.ack],
|
|
ackNumber: 1,
|
|
sequenceNumber: 1,
|
|
srcPort: .init(clientAddress.port!),
|
|
dstPort: .init(serverAddress.port!))))
|
|
self.writeBuffer(self.buffer)
|
|
} catch {
|
|
context.fireErrorCaught(error)
|
|
}
|
|
context.fireChannelActive()
|
|
}
|
|
|
|
public func channelInactive(context: ChannelHandlerContext) {
|
|
let didLocalInitiateTheClose: Bool
|
|
switch self.closeState {
|
|
case .closedInitiatorLocal:
|
|
didLocalInitiateTheClose = true
|
|
case .closedInitiatorRemote:
|
|
didLocalInitiateTheClose = false
|
|
case .notClosing:
|
|
self.closeState = .closedInitiatorRemote
|
|
didLocalInitiateTheClose = false
|
|
}
|
|
|
|
self.buffer.clear()
|
|
do {
|
|
let closeInitiatorAddress = didLocalInitiateTheClose ? self.localAddress(context: context) : self.remoteAddress(context: context)
|
|
let closeRecipientAddress = didLocalInitiateTheClose ? self.remoteAddress(context: context) : self.localAddress(context: context)
|
|
let initiatorSeq = self.sequenceNumber(byteCount: didLocalInitiateTheClose ?
|
|
self.writtenOutboundBytes : self.readInboundBytes)
|
|
let recipientSeq = self.sequenceNumber(byteCount: didLocalInitiateTheClose ?
|
|
self.readInboundBytes : self.writtenOutboundBytes)
|
|
|
|
// terminate the connection cleanly
|
|
try self.buffer.writePCAPRecord(.init(payloadLength: 0,
|
|
src: closeInitiatorAddress,
|
|
dst: closeRecipientAddress,
|
|
tcp: TCPHeader(flags: [.fin],
|
|
ackNumber: nil,
|
|
sequenceNumber: initiatorSeq,
|
|
srcPort: .init(closeInitiatorAddress.port!),
|
|
dstPort: .init(closeRecipientAddress.port!))))
|
|
try self.buffer.writePCAPRecord(.init(payloadLength: 0,
|
|
src: closeRecipientAddress,
|
|
dst: closeInitiatorAddress,
|
|
tcp: TCPHeader(flags: [.ack, .fin],
|
|
ackNumber: initiatorSeq + 1,
|
|
sequenceNumber: recipientSeq,
|
|
srcPort: .init(closeRecipientAddress.port!),
|
|
dstPort: .init(closeInitiatorAddress.port!))))
|
|
try self.buffer.writePCAPRecord(.init(payloadLength: 0,
|
|
src: closeInitiatorAddress,
|
|
dst: closeRecipientAddress,
|
|
tcp: TCPHeader(flags: [.ack],
|
|
ackNumber: recipientSeq + 1,
|
|
sequenceNumber: initiatorSeq + 1,
|
|
srcPort: .init(closeInitiatorAddress.port!),
|
|
dstPort: .init(closeRecipientAddress.port!))))
|
|
self.writeBuffer(self.buffer)
|
|
} catch {
|
|
context.fireErrorCaught(error)
|
|
}
|
|
context.fireChannelInactive()
|
|
}
|
|
|
|
public func channelRead(context: ChannelHandlerContext, data: NIOAny) {
|
|
defer {
|
|
context.fireChannelRead(data)
|
|
}
|
|
guard self.closeState == .notClosing else {
|
|
return
|
|
}
|
|
|
|
let data = self.unwrapInboundIn(data)
|
|
guard data.readableBytes > 0 else {
|
|
return
|
|
}
|
|
|
|
self.buffer.clear()
|
|
do {
|
|
var data = data
|
|
while var payloadToSend = self.takeSensiblySizedPayload(buffer: &data) {
|
|
try self.buffer.writePCAPRecord(.init(payloadLength: payloadToSend.readableBytes,
|
|
src: self.remoteAddress(context: context),
|
|
dst: self.localAddress(context: context),
|
|
tcp: TCPHeader(flags: [],
|
|
ackNumber: nil,
|
|
sequenceNumber: self.sequenceNumber(byteCount: self.readInboundBytes),
|
|
srcPort: .init(self.remoteAddress(context: context).port!),
|
|
dstPort: .init(self.localAddress(context: context).port!))))
|
|
self.readInboundBytes += UInt64(payloadToSend.readableBytes)
|
|
self.buffer.writeBuffer(&payloadToSend)
|
|
}
|
|
assert(data.readableBytes == 0)
|
|
self.writeBuffer(self.buffer)
|
|
} catch {
|
|
context.fireErrorCaught(error)
|
|
}
|
|
}
|
|
|
|
public func write(context: ChannelHandlerContext, data: NIOAny, promise: EventLoopPromise<Void>?) {
|
|
var buffer = self.unwrapInboundIn(data)
|
|
|
|
func emitWrites() {
|
|
do {
|
|
self.buffer.clear()
|
|
while var payloadToSend = self.takeSensiblySizedPayload(buffer: &buffer) {
|
|
try self.buffer.writePCAPRecord(.init(payloadLength: payloadToSend.readableBytes,
|
|
src: self.localAddress(context: context),
|
|
dst: self.remoteAddress(context: context),
|
|
tcp: TCPHeader(flags: [],
|
|
ackNumber: nil,
|
|
sequenceNumber: self.sequenceNumber(byteCount: self.writtenOutboundBytes),
|
|
srcPort: .init(self.localAddress(context: context).port!),
|
|
dstPort: .init(self.remoteAddress(context: context).port!))))
|
|
self.writtenOutboundBytes += UInt64(payloadToSend.readableBytes)
|
|
self.buffer.writeBuffer(&payloadToSend)
|
|
}
|
|
self.writeBuffer(self.buffer)
|
|
} catch {
|
|
context.fireErrorCaught(error)
|
|
}
|
|
}
|
|
|
|
switch self.settings.emitPCAPWrites {
|
|
case .whenCompleted:
|
|
let promise = promise ?? context.eventLoop.makePromise()
|
|
promise.futureResult.whenSuccess {
|
|
emitWrites()
|
|
}
|
|
context.write(data, promise: promise)
|
|
case .whenIssued:
|
|
emitWrites()
|
|
context.write(data, promise: promise)
|
|
}
|
|
}
|
|
|
|
public func userInboundEventTriggered(context: ChannelHandlerContext, event: Any) {
|
|
if let event = event as? ChannelEvent {
|
|
if event == .inputClosed {
|
|
switch self.closeState {
|
|
case .closedInitiatorLocal:
|
|
() // fair enough, we already closed locally
|
|
case .closedInitiatorRemote:
|
|
() // that's odd but okay
|
|
case .notClosing:
|
|
self.closeState = .closedInitiatorRemote
|
|
}
|
|
}
|
|
}
|
|
context.fireUserInboundEventTriggered(event)
|
|
}
|
|
|
|
public func close(context: ChannelHandlerContext, mode: CloseMode, promise: EventLoopPromise<Void>?) {
|
|
switch self.closeState {
|
|
case .closedInitiatorLocal:
|
|
() // weird, this looks like a double-close
|
|
case .closedInitiatorRemote:
|
|
() // fair enough, already closed I guess
|
|
case .notClosing:
|
|
self.closeState = .closedInitiatorLocal
|
|
}
|
|
context.close(mode: mode, promise: promise)
|
|
}
|
|
}
|
|
|
|
extension ByteBuffer {
|
|
mutating func writePCAPHeader() {
|
|
// guint32 magic_number; /* magic number */
|
|
self.writeInteger(0xa1b2c3d4, endianness: .host, as: UInt32.self)
|
|
// guint16 version_major; /* major version number */
|
|
self.writeInteger(2, endianness: .host, as: UInt16.self)
|
|
// guint16 version_minor; /* minor version number *
|
|
self.writeInteger(4, endianness: .host, as: UInt16.self)
|
|
// gint32 thiszone; /* GMT to local correction */
|
|
self.writeInteger(0, endianness: .host, as: UInt32.self)
|
|
// guint32 sigfigs; /* accuracy of timestamps */
|
|
self.writeInteger(0, endianness: .host, as: UInt32.self)
|
|
// guint32 snaplen; /* max length of captured packets, in octets */
|
|
self.writeInteger(.max, endianness: .host, as: UInt32.self)
|
|
// guint32 network; /* data link type */
|
|
self.writeInteger(0, endianness: .host, as: UInt32.self)
|
|
}
|
|
|
|
mutating func writePCAPRecord(_ record: PCAPRecordHeader) throws {
|
|
let rawDataLength = record.payloadLength
|
|
let tcpLength = rawDataLength + 20 /* TCP header length */
|
|
|
|
// record
|
|
// guint32 ts_sec; /* timestamp seconds */
|
|
self.writeInteger(.init(record.time.tv_sec), endianness: .host, as: UInt32.self)
|
|
// guint32 ts_usec; /* timestamp microseconds */
|
|
self.writeInteger(.init(record.time.tv_usec), endianness: .host, as: UInt32.self)
|
|
// continued below ...
|
|
|
|
switch record.addresses {
|
|
case .v4(let la, let ra):
|
|
let ipv4WholeLength = tcpLength + 20 /* IPv4 header length, included in IPv4 */
|
|
let recordLength = ipv4WholeLength + 4 /* 32 bits for protocol id */
|
|
|
|
// record, continued
|
|
// guint32 incl_len; /* number of octets of packet saved in file */
|
|
self.writeInteger(.init(recordLength), endianness: .host, as: UInt32.self)
|
|
// guint32 orig_len; /* actual length of packet */
|
|
self.writeInteger(.init(recordLength), endianness: .host, as: UInt32.self)
|
|
|
|
self.writeInteger(2, endianness: .host, as: UInt32.self) // IPv4
|
|
|
|
// IPv4 packet
|
|
self.writeInteger(0x45, as: UInt8.self) // IP version (4) & IHL (5)
|
|
self.writeInteger(0, as: UInt8.self) // DSCP
|
|
self.writeInteger(.init(ipv4WholeLength), as: UInt16.self)
|
|
|
|
self.writeInteger(0, as: UInt16.self) // identification
|
|
self.writeInteger(0x4000 /* this set's "don't fragment" */, as: UInt16.self) // flags & fragment offset
|
|
self.writeInteger(.max /* we don't care about TTL */, as: UInt8.self) // TTL
|
|
self.writeInteger(6, as: UInt8.self) // TCP
|
|
self.writeInteger(0, as: UInt16.self) // checksum
|
|
self.writeInteger(la.address.sin_addr.s_addr, endianness: .host, as: UInt32.self)
|
|
self.writeInteger(ra.address.sin_addr.s_addr, endianness: .host, as: UInt32.self)
|
|
case .v6(let la, let ra):
|
|
let ipv6PayloadLength = tcpLength
|
|
let recordLength = ipv6PayloadLength + 4 /* 32 bits for protocol id */ + 40 /* IPv6 header length */
|
|
|
|
// record, continued
|
|
// guint32 incl_len; /* number of octets of packet saved in file */
|
|
self.writeInteger(.init(recordLength), endianness: .host, as: UInt32.self)
|
|
// guint32 orig_len; /* actual length of packet */
|
|
self.writeInteger(.init(recordLength), endianness: .host, as: UInt32.self)
|
|
|
|
self.writeInteger(24, endianness: .host, as: UInt32.self) // IPv6
|
|
|
|
// IPv6 packet
|
|
self.writeInteger(/* version */ (6 << 28), as: UInt32.self) // IP version (6) & fancy stuff
|
|
self.writeInteger(.init(ipv6PayloadLength), as: UInt16.self)
|
|
self.writeInteger(6, as: UInt8.self) // TCP
|
|
self.writeInteger(.max /* we don't care about TTL */, as: UInt8.self) // hop limit (like TTL)
|
|
|
|
var laAddress = la.address
|
|
withUnsafeBytes(of: &laAddress.sin6_addr) { ptr in
|
|
assert(ptr.count == 16)
|
|
self.writeBytes(ptr)
|
|
}
|
|
var raAddress = ra.address
|
|
withUnsafeBytes(of: &raAddress.sin6_addr) { ptr in
|
|
assert(ptr.count == 16)
|
|
self.writeBytes(ptr)
|
|
}
|
|
}
|
|
|
|
// TCP
|
|
self.writeInteger(record.tcp.srcPort, as: UInt16.self)
|
|
self.writeInteger(record.tcp.dstPort, as: UInt16.self)
|
|
|
|
self.writeInteger(record.tcp.sequenceNumber, as: UInt32.self) // seq no
|
|
self.writeInteger(record.tcp.ackNumber ?? 0, as: UInt32.self) // ack no
|
|
|
|
self.writeInteger(5 << 12 | UInt16(record.tcp.flags.rawValue), as: UInt16.self) // data offset + reserved bits + fancy stuff
|
|
self.writeInteger(.max /* we don't do actual window sizes */, as: UInt16.self) // window size
|
|
self.writeInteger(0xbad /* fake */, as: UInt16.self) // checksum
|
|
self.writeInteger(0, as: UInt16.self) // urgent pointer
|
|
}
|
|
}
|
|
|
|
extension NIOWritePCAPHandler {
|
|
/// A synchronised file sink that uses a `DispatchQueue` to do all the necessary write synchronously.
|
|
///
|
|
/// A `SynchronizedFileSink` is thread-safe so can be used from any thread/`EventLoop`. After use, you
|
|
/// _must_ call `syncClose` on the `SynchronizedFileSink` to shut it and all the associated resources down. Failing
|
|
/// to do so triggers undefined behaviour.
|
|
public final class SynchronizedFileSink {
|
|
private let fileHandle: NIOFileHandle
|
|
private let workQueue: DispatchQueue
|
|
private let writesGroup = DispatchGroup()
|
|
private let errorHandler: (Swift.Error) -> Void
|
|
private var state: State = .running /* protected by `workQueue` */
|
|
|
|
public enum FileWritingMode {
|
|
case appendToExistingPCAPFile
|
|
case createNewPCAPFile
|
|
}
|
|
|
|
public struct Error: Swift.Error {
|
|
public var errorCode: Int
|
|
|
|
internal enum ErrorCode: Int {
|
|
case cannotOpenFileError = 1
|
|
case cannotWriteToFileError
|
|
}
|
|
}
|
|
|
|
private enum State {
|
|
case running
|
|
case error(Swift.Error)
|
|
}
|
|
|
|
/// Creates a `SynchronizedFileSink` for writing to a `.pcap` file at `path`.
|
|
///
|
|
/// Typically, after you created a `SynchronizedFileSink`, you will hand `myFileSink.write` to
|
|
/// `NIOWritePCAPHandler`'s constructor so `NIOPCAPHandler` can write `.pcap` files. Example:
|
|
///
|
|
/// ```swift
|
|
/// let fileSink = try NIOWritePCAPHandler.SynchronizedFileSink.fileSinkWritingToFile(path: "test.pcap",
|
|
/// errorHandler: { error in
|
|
/// print("ERROR: \(error)")
|
|
/// })
|
|
/// defer {
|
|
/// try fileSink.syncClose()
|
|
/// }
|
|
/// // [...]
|
|
/// channel.pipeline.addHandler(NIOWritePCAPHandler(mode: .server, fileSink: fileSink.write))
|
|
/// ```
|
|
///
|
|
/// - parameters:
|
|
/// - path: The path of the `.pcap` file to write.
|
|
/// - fileWritingMode: Whether to append to an existing `.pcap` file or to create a new `.pcap` file. If you
|
|
/// choose to append to an existing `.pcap` file, the file header does not get written.
|
|
/// - errorHandler: Invoked when an unrecoverable error has occured. In this event you may log the error and
|
|
/// you must then `syncClose` the `SynchronizedFileSink`. When `errorHandler` has been
|
|
/// called, no further writes will be attempted and `errorHandler` will also not be called
|
|
/// again.
|
|
public static func fileSinkWritingToFile(path: String,
|
|
fileWritingMode: FileWritingMode = .createNewPCAPFile,
|
|
errorHandler: @escaping (Swift.Error) -> Void) throws -> SynchronizedFileSink {
|
|
let oflag: CInt = fileWritingMode == FileWritingMode.createNewPCAPFile ? (O_TRUNC | O_CREAT) : O_APPEND
|
|
let fd = try path.withCString { pathPtr -> CInt in
|
|
let fd = open(pathPtr, O_WRONLY | oflag, 0o600)
|
|
guard fd >= 0 else {
|
|
throw SynchronizedFileSink.Error(errorCode: Error.ErrorCode.cannotOpenFileError.rawValue)
|
|
}
|
|
return fd
|
|
}
|
|
|
|
if fileWritingMode == .createNewPCAPFile {
|
|
let writeOk = NIOWritePCAPHandler.pcapFileHeader.withUnsafeReadableBytes { ptr in
|
|
return sysWrite(fd, ptr.baseAddress, ptr.count) == ptr.count
|
|
}
|
|
guard writeOk else {
|
|
throw SynchronizedFileSink.Error(errorCode: Error.ErrorCode.cannotWriteToFileError.rawValue)
|
|
}
|
|
}
|
|
return SynchronizedFileSink(fileHandle: NIOFileHandle(descriptor: fd),
|
|
errorHandler: errorHandler)
|
|
}
|
|
|
|
private init(fileHandle: NIOFileHandle,
|
|
errorHandler: @escaping (Swift.Error) -> Void) {
|
|
self.fileHandle = fileHandle
|
|
self.workQueue = DispatchQueue(label: "io.swiftnio.extras.WritePCAPHandler.SynchronizedFileSink.workQueue")
|
|
self.errorHandler = errorHandler
|
|
}
|
|
|
|
/// Synchronously close this `SynchronizedFileSink` and any associated resources.
|
|
///
|
|
/// After use, it is mandatory to close a `SynchronizedFileSink` exactly once. `syncClose` may be called from
|
|
/// any thread but not from an `EventLoop` as it will block.
|
|
public func syncClose() throws {
|
|
self.writesGroup.wait()
|
|
try self.workQueue.sync {
|
|
try self.fileHandle.close()
|
|
}
|
|
}
|
|
|
|
public func write(buffer: ByteBuffer) {
|
|
self.workQueue.async(group: self.writesGroup) {
|
|
guard case .running = self.state else {
|
|
return
|
|
}
|
|
do {
|
|
try self.fileHandle.withUnsafeFileDescriptor { fd in
|
|
var buffer = buffer
|
|
while buffer.readableBytes > 0 {
|
|
try buffer.readWithUnsafeReadableBytes { dataPtr in
|
|
let r = sysWrite(fd, dataPtr.baseAddress, dataPtr.count)
|
|
assert(r != 0, "write returned 0 but we tried to write \(dataPtr.count) bytes")
|
|
guard r > 0 else {
|
|
throw Error.init(errorCode: Error.ErrorCode.cannotWriteToFileError.rawValue)
|
|
}
|
|
return r
|
|
}
|
|
}
|
|
}
|
|
} catch {
|
|
self.state = .error(error)
|
|
self.errorHandler(error)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
#if swift(>=5.5) && canImport(_Concurrency)
|
|
extension NIOWritePCAPHandler.SynchronizedFileSink: @unchecked Sendable {
|
|
|
|
}
|
|
#endif
|