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Diffstat (limited to 'vendor/github.com/google/gopacket/parser.go')
| -rw-r--r-- | vendor/github.com/google/gopacket/parser.go | 198 |
1 files changed, 0 insertions, 198 deletions
diff --git a/vendor/github.com/google/gopacket/parser.go b/vendor/github.com/google/gopacket/parser.go deleted file mode 100644 index f786834..0000000 --- a/vendor/github.com/google/gopacket/parser.go +++ /dev/null @@ -1,198 +0,0 @@ -// 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 ( - "fmt" -) - -// DecodingLayer is an interface for packet layers that can decode themselves. -// -// The important part of DecodingLayer is that they decode themselves in-place. -// Calling DecodeFromBytes on a DecodingLayer totally resets the entire layer to -// the new state defined by the data passed in. A returned error leaves the -// DecodingLayer in an unknown intermediate state, thus its fields should not be -// trusted. -// -// Because the DecodingLayer is resetting its own fields, a call to -// DecodeFromBytes should normally not require any memory allocation. -type DecodingLayer interface { - // DecodeFromBytes resets the internal state of this layer to the state - // defined by the passed-in bytes. Slices in the DecodingLayer may - // reference the passed-in data, so care should be taken to copy it - // first should later modification of data be required before the - // DecodingLayer is discarded. - DecodeFromBytes(data []byte, df DecodeFeedback) error - // CanDecode returns the set of LayerTypes this DecodingLayer can - // decode. For Layers that are also DecodingLayers, this will most - // often be that Layer's LayerType(). - CanDecode() LayerClass - // NextLayerType returns the LayerType which should be used to decode - // the LayerPayload. - NextLayerType() LayerType - // LayerPayload is the set of bytes remaining to decode after a call to - // DecodeFromBytes. - LayerPayload() []byte -} - -// DecodingLayerParser parses a given set of layer types. See DecodeLayers for -// more information on how DecodingLayerParser should be used. -type DecodingLayerParser struct { - // DecodingLayerParserOptions is the set of options available to the - // user to define the parser's behavior. - DecodingLayerParserOptions - first LayerType - decoders map[LayerType]DecodingLayer - df DecodeFeedback - // Truncated is set when a decode layer detects that the packet has been - // truncated. - Truncated bool -} - -// AddDecodingLayer adds a decoding layer to the parser. This adds support for -// the decoding layer's CanDecode layers to the parser... should they be -// encountered, they'll be parsed. -func (l *DecodingLayerParser) AddDecodingLayer(d DecodingLayer) { - for _, typ := range d.CanDecode().LayerTypes() { - l.decoders[typ] = d - } -} - -// SetTruncated is used by DecodingLayers to set the Truncated boolean in the -// DecodingLayerParser. Users should simply read Truncated after calling -// DecodeLayers. -func (l *DecodingLayerParser) SetTruncated() { - l.Truncated = true -} - -// NewDecodingLayerParser creates a new DecodingLayerParser and adds in all -// of the given DecodingLayers with AddDecodingLayer. -// -// Each call to DecodeLayers will attempt to decode the given bytes first by -// treating them as a 'first'-type layer, then by using NextLayerType on -// subsequently decoded layers to find the next relevant decoder. Should a -// deoder not be available for the layer type returned by NextLayerType, -// decoding will stop. -func NewDecodingLayerParser(first LayerType, decoders ...DecodingLayer) *DecodingLayerParser { - dlp := &DecodingLayerParser{ - decoders: make(map[LayerType]DecodingLayer), - first: first, - } - dlp.df = dlp // Cast this once to the interface - for _, d := range decoders { - dlp.AddDecodingLayer(d) - } - return dlp -} - -// DecodeLayers decodes as many layers as possible from the given data. It -// initially treats the data as layer type 'typ', then uses NextLayerType on -// each subsequent decoded layer until it gets to a layer type it doesn't know -// how to parse. -// -// For each layer successfully decoded, DecodeLayers appends the layer type to -// the decoded slice. DecodeLayers truncates the 'decoded' slice initially, so -// there's no need to empty it yourself. -// -// This decoding method is about an order of magnitude faster than packet -// decoding, because it only decodes known layers that have already been -// allocated. This means it doesn't need to allocate each layer it returns... -// instead it overwrites the layers that already exist. -// -// Example usage: -// func main() { -// var eth layers.Ethernet -// var ip4 layers.IPv4 -// var ip6 layers.IPv6 -// var tcp layers.TCP -// var udp layers.UDP -// var payload gopacket.Payload -// parser := gopacket.NewDecodingLayerParser(layers.LayerTypeEthernet, ð, &ip4, &ip6, &tcp, &udp, &payload) -// var source gopacket.PacketDataSource = getMyDataSource() -// decodedLayers := make([]gopacket.LayerType, 0, 10) -// for { -// data, _, err := source.ReadPacketData() -// if err == nil { -// fmt.Println("Error reading packet data: ", err) -// continue -// } -// fmt.Println("Decoding packet") -// err = parser.DecodeLayers(data, &decodedLayers) -// for _, typ := range decodedLayers { -// fmt.Println(" Successfully decoded layer type", typ) -// switch typ { -// case layers.LayerTypeEthernet: -// fmt.Println(" Eth ", eth.SrcMAC, eth.DstMAC) -// case layers.LayerTypeIPv4: -// fmt.Println(" IP4 ", ip4.SrcIP, ip4.DstIP) -// case layers.LayerTypeIPv6: -// fmt.Println(" IP6 ", ip6.SrcIP, ip6.DstIP) -// case layers.LayerTypeTCP: -// fmt.Println(" TCP ", tcp.SrcPort, tcp.DstPort) -// case layers.LayerTypeUDP: -// fmt.Println(" UDP ", udp.SrcPort, udp.DstPort) -// } -// } -// if decodedLayers.Truncated { -// fmt.Println(" Packet has been truncated") -// } -// if err != nil { -// fmt.Println(" Error encountered:", err) -// } -// } -// } -// -// If DecodeLayers is unable to decode the next layer type, it will return the -// error UnsupportedLayerType. -func (l *DecodingLayerParser) DecodeLayers(data []byte, decoded *[]LayerType) (err error) { - l.Truncated = false - if !l.IgnorePanic { - defer panicToError(&err) - } - typ := l.first - *decoded = (*decoded)[:0] // Truncated decoded layers. - for len(data) > 0 { - decoder, ok := l.decoders[typ] - if !ok { - return UnsupportedLayerType(typ) - } else if err = decoder.DecodeFromBytes(data, l.df); err != nil { - return err - } - *decoded = append(*decoded, typ) - typ = decoder.NextLayerType() - data = decoder.LayerPayload() - } - return nil -} - -// UnsupportedLayerType is returned by DecodingLayerParser if DecodeLayers -// encounters a layer type that the DecodingLayerParser has no decoder for. -type UnsupportedLayerType LayerType - -// Error implements the error interface, returning a string to say that the -// given layer type is unsupported. -func (e UnsupportedLayerType) Error() string { - return fmt.Sprintf("No decoder for layer type %v", LayerType(e)) -} - -func panicToError(e *error) { - if r := recover(); r != nil { - *e = fmt.Errorf("panic: %v", r) - } -} - -// DecodingLayerParserOptions provides options to affect the behavior of a given -// DecodingLayerParser. -type DecodingLayerParserOptions struct { - // IgnorePanic determines whether a DecodingLayerParser should stop - // panics on its own (by returning them as an error from DecodeLayers) - // or should allow them to raise up the stack. Handling errors does add - // latency to the process of decoding layers, but is much safer for - // callers. IgnorePanic defaults to false, thus if the caller does - // nothing decode panics will be returned as errors. - IgnorePanic bool -} |