From 3f1edad4e6ba0a7876750aea55507fae14d8badf Mon Sep 17 00:00:00 2001 From: Milan Lenco Date: Wed, 11 Oct 2017 16:40:58 +0200 Subject: ODPM 266: Go-libmemif + 2 examples. Change-Id: Icdb9b9eb2314eff6c96afe7996fcf2728291de4a Signed-off-by: Milan Lenco --- vendor/github.com/google/gopacket/decode.go | 157 ++++++++++++++++++++++++++++ 1 file changed, 157 insertions(+) create mode 100644 vendor/github.com/google/gopacket/decode.go (limited to 'vendor/github.com/google/gopacket/decode.go') diff --git a/vendor/github.com/google/gopacket/decode.go b/vendor/github.com/google/gopacket/decode.go new file mode 100644 index 0000000..2633f84 --- /dev/null +++ b/vendor/github.com/google/gopacket/decode.go @@ -0,0 +1,157 @@ +// Copyright 2012 Google, Inc. All rights reserved. +// +// Use of this source code is governed by a BSD-style license +// that can be found in the LICENSE file in the root of the source +// tree. + +package gopacket + +import ( + "errors" +) + +// DecodeFeedback is used by DecodingLayer layers to provide decoding metadata. +type DecodeFeedback interface { + // SetTruncated should be called if during decoding you notice that a packet + // is shorter than internal layer variables (HeaderLength, or the like) say it + // should be. It sets packet.Metadata().Truncated. + SetTruncated() +} + +type nilDecodeFeedback struct{} + +func (nilDecodeFeedback) SetTruncated() {} + +// NilDecodeFeedback implements DecodeFeedback by doing nothing. +var NilDecodeFeedback DecodeFeedback = nilDecodeFeedback{} + +// PacketBuilder is used by layer decoders to store the layers they've decoded, +// and to defer future decoding via NextDecoder. +// Typically, the pattern for use is: +// func (m *myDecoder) Decode(data []byte, p PacketBuilder) error { +// if myLayer, err := myDecodingLogic(data); err != nil { +// return err +// } else { +// p.AddLayer(myLayer) +// } +// // maybe do this, if myLayer is a LinkLayer +// p.SetLinkLayer(myLayer) +// return p.NextDecoder(nextDecoder) +// } +type PacketBuilder interface { + DecodeFeedback + // AddLayer should be called by a decoder immediately upon successful + // decoding of a layer. + AddLayer(l Layer) + // The following functions set the various specific layers in the final + // packet. Note that if many layers call SetX, the first call is kept and all + // other calls are ignored. + SetLinkLayer(LinkLayer) + SetNetworkLayer(NetworkLayer) + SetTransportLayer(TransportLayer) + SetApplicationLayer(ApplicationLayer) + SetErrorLayer(ErrorLayer) + // NextDecoder should be called by a decoder when they're done decoding a + // packet layer but not done with decoding the entire packet. The next + // decoder will be called to decode the last AddLayer's LayerPayload. + // Because of this, NextDecoder must only be called once all other + // PacketBuilder calls have been made. Set*Layer and AddLayer calls after + // NextDecoder calls will behave incorrectly. + NextDecoder(next Decoder) error + // DumpPacketData is used solely for decoding. If you come across an error + // you need to diagnose while processing a packet, call this and your packet's + // data will be dumped to stderr so you can create a test. This should never + // be called from a production decoder. + DumpPacketData() + // DecodeOptions returns the decode options + DecodeOptions() *DecodeOptions +} + +// Decoder is an interface for logic to decode a packet layer. Users may +// implement a Decoder to handle their own strange packet types, or may use one +// of the many decoders available in the 'layers' subpackage to decode things +// for them. +type Decoder interface { + // Decode decodes the bytes of a packet, sending decoded values and other + // information to PacketBuilder, and returning an error if unsuccessful. See + // the PacketBuilder documentation for more details. + Decode([]byte, PacketBuilder) error +} + +// DecodeFunc wraps a function to make it a Decoder. +type DecodeFunc func([]byte, PacketBuilder) error + +// Decode implements Decoder by calling itself. +func (d DecodeFunc) Decode(data []byte, p PacketBuilder) error { + // function, call thyself. + return d(data, p) +} + +// DecodePayload is a Decoder that returns a Payload layer containing all +// remaining bytes. +var DecodePayload Decoder = DecodeFunc(decodePayload) + +// DecodeUnknown is a Decoder that returns an Unknown layer containing all +// remaining bytes, useful if you run up against a layer that you're unable to +// decode yet. This layer is considered an ErrorLayer. +var DecodeUnknown Decoder = DecodeFunc(decodeUnknown) + +// DecodeFragment is a Decoder that returns a Fragment layer containing all +// remaining bytes. +var DecodeFragment Decoder = DecodeFunc(decodeFragment) + +// LayerTypeZero is an invalid layer type, but can be used to determine whether +// layer type has actually been set correctly. +var LayerTypeZero = RegisterLayerType(0, LayerTypeMetadata{Name: "Unknown", Decoder: DecodeUnknown}) + +// LayerTypeDecodeFailure is the layer type for the default error layer. +var LayerTypeDecodeFailure = RegisterLayerType(1, LayerTypeMetadata{Name: "DecodeFailure", Decoder: DecodeUnknown}) + +// LayerTypePayload is the layer type for a payload that we don't try to decode +// but treat as a success, IE: an application-level payload. +var LayerTypePayload = RegisterLayerType(2, LayerTypeMetadata{Name: "Payload", Decoder: DecodePayload}) + +// LayerTypeFragment is the layer type for a fragment of a layer transported +// by an underlying layer that supports fragmentation. +var LayerTypeFragment = RegisterLayerType(3, LayerTypeMetadata{Name: "Fragment", Decoder: DecodeFragment}) + +// DecodeFailure is a packet layer created if decoding of the packet data failed +// for some reason. It implements ErrorLayer. LayerContents will be the entire +// set of bytes that failed to parse, and Error will return the reason parsing +// failed. +type DecodeFailure struct { + data []byte + err error + stack []byte +} + +// Error returns the error encountered during decoding. +func (d *DecodeFailure) Error() error { return d.err } + +// LayerContents implements Layer. +func (d *DecodeFailure) LayerContents() []byte { return d.data } + +// LayerPayload implements Layer. +func (d *DecodeFailure) LayerPayload() []byte { return nil } + +// String implements fmt.Stringer. +func (d *DecodeFailure) String() string { + return "Packet decoding error: " + d.Error().Error() +} + +// Dump implements Dumper. +func (d *DecodeFailure) Dump() (s string) { + if d.stack != nil { + s = string(d.stack) + } + return +} + +// LayerType returns LayerTypeDecodeFailure +func (d *DecodeFailure) LayerType() LayerType { return LayerTypeDecodeFailure } + +// decodeUnknown "decodes" unsupported data types by returning an error. +// This decoder will thus always return a DecodeFailure layer. +func decodeUnknown(data []byte, p PacketBuilder) error { + return errors.New("Layer type not currently supported") +} -- cgit 1.2.3-korg