diff options
Diffstat (limited to 'vendor/github.com/google/gopacket/layers/ctp.go')
-rw-r--r-- | vendor/github.com/google/gopacket/layers/ctp.go | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/vendor/github.com/google/gopacket/layers/ctp.go b/vendor/github.com/google/gopacket/layers/ctp.go new file mode 100644 index 0000000..8287584 --- /dev/null +++ b/vendor/github.com/google/gopacket/layers/ctp.go @@ -0,0 +1,109 @@ +// 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 layers + +import ( + "encoding/binary" + "fmt" + "github.com/google/gopacket" +) + +// EthernetCTPFunction is the function code used by the EthernetCTP protocol to identify each +// EthernetCTP layer. +type EthernetCTPFunction uint16 + +// EthernetCTPFunction values. +const ( + EthernetCTPFunctionReply EthernetCTPFunction = 1 + EthernetCTPFunctionForwardData EthernetCTPFunction = 2 +) + +// EthernetCTP implements the EthernetCTP protocol, see http://www.mit.edu/people/jhawk/ctp.html. +// We split EthernetCTP up into the top-level EthernetCTP layer, followed by zero or more +// EthernetCTPForwardData layers, followed by a final EthernetCTPReply layer. +type EthernetCTP struct { + BaseLayer + SkipCount uint16 +} + +// LayerType returns gopacket.LayerTypeEthernetCTP. +func (c *EthernetCTP) LayerType() gopacket.LayerType { + return LayerTypeEthernetCTP +} + +// EthernetCTPForwardData is the ForwardData layer inside EthernetCTP. See EthernetCTP's docs for more +// details. +type EthernetCTPForwardData struct { + BaseLayer + Function EthernetCTPFunction + ForwardAddress []byte +} + +// LayerType returns gopacket.LayerTypeEthernetCTPForwardData. +func (c *EthernetCTPForwardData) LayerType() gopacket.LayerType { + return LayerTypeEthernetCTPForwardData +} + +// ForwardEndpoint returns the EthernetCTPForwardData ForwardAddress as an endpoint. +func (c *EthernetCTPForwardData) ForwardEndpoint() gopacket.Endpoint { + return gopacket.NewEndpoint(EndpointMAC, c.ForwardAddress) +} + +// EthernetCTPReply is the Reply layer inside EthernetCTP. See EthernetCTP's docs for more details. +type EthernetCTPReply struct { + BaseLayer + Function EthernetCTPFunction + ReceiptNumber uint16 + Data []byte +} + +// LayerType returns gopacket.LayerTypeEthernetCTPReply. +func (c *EthernetCTPReply) LayerType() gopacket.LayerType { + return LayerTypeEthernetCTPReply +} + +// Payload returns the EthernetCTP reply's Data bytes. +func (c *EthernetCTPReply) Payload() []byte { return c.Data } + +func decodeEthernetCTP(data []byte, p gopacket.PacketBuilder) error { + c := &EthernetCTP{ + SkipCount: binary.LittleEndian.Uint16(data[:2]), + BaseLayer: BaseLayer{data[:2], data[2:]}, + } + if c.SkipCount%2 != 0 { + return fmt.Errorf("EthernetCTP skip count is odd: %d", c.SkipCount) + } + p.AddLayer(c) + return p.NextDecoder(gopacket.DecodeFunc(decodeEthernetCTPFromFunctionType)) +} + +// decodeEthernetCTPFromFunctionType reads in the first 2 bytes to determine the EthernetCTP +// layer type to decode next, then decodes based on that. +func decodeEthernetCTPFromFunctionType(data []byte, p gopacket.PacketBuilder) error { + function := EthernetCTPFunction(binary.LittleEndian.Uint16(data[:2])) + switch function { + case EthernetCTPFunctionReply: + reply := &EthernetCTPReply{ + Function: function, + ReceiptNumber: binary.LittleEndian.Uint16(data[2:4]), + Data: data[4:], + BaseLayer: BaseLayer{data, nil}, + } + p.AddLayer(reply) + p.SetApplicationLayer(reply) + return nil + case EthernetCTPFunctionForwardData: + forward := &EthernetCTPForwardData{ + Function: function, + ForwardAddress: data[2:8], + BaseLayer: BaseLayer{data[:8], data[8:]}, + } + p.AddLayer(forward) + return p.NextDecoder(gopacket.DecodeFunc(decodeEthernetCTPFromFunctionType)) + } + return fmt.Errorf("Unknown EthernetCTP function type %v", function) +} |