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/layers/dhcpv4.go | 571 +++++++++++++++++++++ 1 file changed, 571 insertions(+) create mode 100644 vendor/github.com/google/gopacket/layers/dhcpv4.go (limited to 'vendor/github.com/google/gopacket/layers/dhcpv4.go') diff --git a/vendor/github.com/google/gopacket/layers/dhcpv4.go b/vendor/github.com/google/gopacket/layers/dhcpv4.go new file mode 100644 index 0000000..761b201 --- /dev/null +++ b/vendor/github.com/google/gopacket/layers/dhcpv4.go @@ -0,0 +1,571 @@ +// Copyright 2016 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 ( + "bytes" + "encoding/binary" + "errors" + "fmt" + "net" + + "github.com/google/gopacket" +) + +// DHCPOp rerprents a bootp operation +type DHCPOp byte + +// bootp operations +const ( + DHCPOpRequest DHCPOp = 1 + DHCPOpReply DHCPOp = 2 +) + +// String returns a string version of a DHCPOp. +func (o DHCPOp) String() string { + switch o { + case DHCPOpRequest: + return "Request" + case DHCPOpReply: + return "Reply" + default: + return "Unknown" + } +} + +// DHCPMsgType represents a DHCP operation +type DHCPMsgType byte + +// Constants that represent DHCP operations +const ( + DHCPMsgTypeUnspecified DHCPMsgType = iota + DHCPMsgTypeDiscover + DHCPMsgTypeOffer + DHCPMsgTypeRequest + DHCPMsgTypeDecline + DHCPMsgTypeAck + DHCPMsgTypeNak + DHCPMsgTypeRelease + DHCPMsgTypeInform +) + +// String returns a string version of a DHCPMsgType. +func (o DHCPMsgType) String() string { + switch o { + case DHCPMsgTypeUnspecified: + return "Unspecified" + case DHCPMsgTypeDiscover: + return "Discover" + case DHCPMsgTypeOffer: + return "Offer" + case DHCPMsgTypeRequest: + return "Request" + case DHCPMsgTypeDecline: + return "Decline" + case DHCPMsgTypeAck: + return "Ack" + case DHCPMsgTypeNak: + return "Nak" + case DHCPMsgTypeRelease: + return "Release" + case DHCPMsgTypeInform: + return "Inform" + default: + return "Unknown" + } +} + +//DHCPMagic is the RFC 2131 "magic cooke" for DHCP. +var DHCPMagic uint32 = 0x63825363 + +// DHCPv4 contains data for a single DHCP packet. +type DHCPv4 struct { + BaseLayer + Operation DHCPOp + HardwareType LinkType + HardwareLen uint8 + HardwareOpts uint8 + Xid uint32 + Secs uint16 + Flags uint16 + ClientIP net.IP + YourClientIP net.IP + NextServerIP net.IP + RelayAgentIP net.IP + ClientHWAddr net.HardwareAddr + ServerName []byte + File []byte + Options DHCPOptions +} + +// DHCPOptions is used to get nicely printed option lists which would normally +// be cut off after 5 options. +type DHCPOptions []DHCPOption + +// String returns a string version of the options list. +func (o DHCPOptions) String() string { + buf := &bytes.Buffer{} + buf.WriteByte('[') + for i, opt := range o { + buf.WriteString(opt.String()) + if i+1 != len(o) { + buf.WriteString(", ") + } + } + buf.WriteByte(']') + return buf.String() +} + +// LayerType returns gopacket.LayerTypeDHCPv4 +func (d *DHCPv4) LayerType() gopacket.LayerType { return LayerTypeDHCPv4 } + +// DecodeFromBytes decodes the given bytes into this layer. +func (d *DHCPv4) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error { + d.Operation = DHCPOp(data[0]) + d.HardwareType = LinkType(data[1]) + d.HardwareLen = data[2] + d.HardwareOpts = data[3] + d.Xid = binary.BigEndian.Uint32(data[4:8]) + d.Secs = binary.BigEndian.Uint16(data[8:10]) + d.Flags = binary.BigEndian.Uint16(data[10:12]) + d.ClientIP = net.IP(data[12:16]) + d.YourClientIP = net.IP(data[16:20]) + d.NextServerIP = net.IP(data[20:24]) + d.RelayAgentIP = net.IP(data[24:28]) + d.ClientHWAddr = net.HardwareAddr(data[28 : 28+d.HardwareLen]) + d.ServerName = data[44:108] + d.File = data[108:236] + if binary.BigEndian.Uint32(data[236:240]) != DHCPMagic { + return errors.New("Bad DHCP header") + } + + if len(data) <= 240 { + // DHCP Packet could have no option (??) + return nil + } + + options := data[240:] + + stop := len(options) + start := 0 + for start < stop { + o := DHCPOption{} + if err := o.decode(options[start:]); err != nil { + return err + } + if o.Type == DHCPOptEnd { + break + } + d.Options = append(d.Options, o) + // Check if the option is a single byte pad + if o.Type == DHCPOptPad { + start++ + } else { + start += int(o.Length) + 2 + } + } + return nil +} + +// Len returns the length of a DHCPv4 packet. +func (d *DHCPv4) Len() uint16 { + n := uint16(240) + for _, o := range d.Options { + if o.Type == DHCPOptPad { + n++ + } else { + n += uint16(o.Length) + 2 + } + } + n++ // for opt end + return n +} + +// SerializeTo writes the serialized form of this layer into the +// SerializationBuffer, implementing gopacket.SerializableLayer. +// See the docs for gopacket.SerializableLayer for more info. +func (d *DHCPv4) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error { + plen := int(d.Len()) + + data, err := b.PrependBytes(plen) + if err != nil { + return err + } + + data[0] = byte(d.Operation) + data[1] = byte(d.HardwareType) + if opts.FixLengths { + d.HardwareLen = uint8(len(d.ClientHWAddr)) + } + data[2] = d.HardwareLen + data[3] = d.HardwareOpts + binary.BigEndian.PutUint32(data[4:8], d.Xid) + binary.BigEndian.PutUint16(data[8:10], d.Secs) + binary.BigEndian.PutUint16(data[10:12], d.Flags) + copy(data[12:16], d.ClientIP.To4()) + copy(data[16:20], d.YourClientIP.To4()) + copy(data[20:24], d.NextServerIP.To4()) + copy(data[24:28], d.RelayAgentIP.To4()) + copy(data[28:44], d.ClientHWAddr) + copy(data[44:108], d.ServerName) + copy(data[108:236], d.File) + binary.BigEndian.PutUint32(data[236:240], DHCPMagic) + + if len(d.Options) > 0 { + offset := 240 + for _, o := range d.Options { + if err := o.encode(data[offset:]); err != nil { + return err + } + // A pad option is only a single byte + if o.Type == DHCPOptPad { + offset++ + } else { + offset += 2 + len(o.Data) + } + } + optend := NewDHCPOption(DHCPOptEnd, nil) + if err := optend.encode(data[offset:]); err != nil { + return err + } + } + return nil +} + +// CanDecode returns the set of layer types that this DecodingLayer can decode. +func (d *DHCPv4) CanDecode() gopacket.LayerClass { + return LayerTypeDHCPv4 +} + +// NextLayerType returns the layer type contained by this DecodingLayer. +func (d *DHCPv4) NextLayerType() gopacket.LayerType { + return gopacket.LayerTypePayload +} + +func decodeDHCPv4(data []byte, p gopacket.PacketBuilder) error { + dhcp := &DHCPv4{} + err := dhcp.DecodeFromBytes(data, p) + if err != nil { + return err + } + p.AddLayer(dhcp) + return p.NextDecoder(gopacket.LayerTypePayload) +} + +// DHCPOpt represents a DHCP option or parameter from RFC-2132 +type DHCPOpt byte + +// Constants for the DHCPOpt options. +const ( + DHCPOptPad DHCPOpt = 0 + DHCPOptSubnetMask DHCPOpt = 1 // 4, net.IP + DHCPOptTimeOffset DHCPOpt = 2 // 4, int32 (signed seconds from UTC) + DHCPOptRouter DHCPOpt = 3 // n*4, [n]net.IP + DHCPOptTimeServer DHCPOpt = 4 // n*4, [n]net.IP + DHCPOptNameServer DHCPOpt = 5 // n*4, [n]net.IP + DHCPOptDNS DHCPOpt = 6 // n*4, [n]net.IP + DHCPOptLogServer DHCPOpt = 7 // n*4, [n]net.IP + DHCPOptCookieServer DHCPOpt = 8 // n*4, [n]net.IP + DHCPOptLPRServer DHCPOpt = 9 // n*4, [n]net.IP + DHCPOptImpressServer DHCPOpt = 10 // n*4, [n]net.IP + DHCPOptResLocServer DHCPOpt = 11 // n*4, [n]net.IP + DHCPOptHostname DHCPOpt = 12 // n, string + DHCPOptBootfileSize DHCPOpt = 13 // 2, uint16 + DHCPOptMeritDumpFile DHCPOpt = 14 // >1, string + DHCPOptDomainName DHCPOpt = 15 // n, string + DHCPOptSwapServer DHCPOpt = 16 // n*4, [n]net.IP + DHCPOptRootPath DHCPOpt = 17 // n, string + DHCPOptExtensionsPath DHCPOpt = 18 // n, string + DHCPOptIPForwarding DHCPOpt = 19 // 1, bool + DHCPOptSourceRouting DHCPOpt = 20 // 1, bool + DHCPOptPolicyFilter DHCPOpt = 21 // 8*n, [n]{net.IP/net.IP} + DHCPOptDatagramMTU DHCPOpt = 22 // 2, uint16 + DHCPOptDefaultTTL DHCPOpt = 23 // 1, byte + DHCPOptPathMTUAgingTimeout DHCPOpt = 24 // 4, uint32 + DHCPOptPathPlateuTableOption DHCPOpt = 25 // 2*n, []uint16 + DHCPOptInterfaceMTU DHCPOpt = 26 // 2, uint16 + DHCPOptAllSubsLocal DHCPOpt = 27 // 1, bool + DHCPOptBroadcastAddr DHCPOpt = 28 // 4, net.IP + DHCPOptMaskDiscovery DHCPOpt = 29 // 1, bool + DHCPOptMaskSupplier DHCPOpt = 30 // 1, bool + DHCPOptRouterDiscovery DHCPOpt = 31 // 1, bool + DHCPOptSolicitAddr DHCPOpt = 32 // 4, net.IP + DHCPOptStaticRoute DHCPOpt = 33 // n*8, [n]{net.IP/net.IP} -- note the 2nd is router not mask + DHCPOptARPTrailers DHCPOpt = 34 // 1, bool + DHCPOptARPTimeout DHCPOpt = 35 // 4, uint32 + DHCPOptEthernetEncap DHCPOpt = 36 // 1, bool + DHCPOptTCPTTL DHCPOpt = 37 // 1, byte + DHCPOptTCPKeepAliveInt DHCPOpt = 38 // 4, uint32 + DHCPOptTCPKeepAliveGarbage DHCPOpt = 39 // 1, bool + DHCPOptNISDomain DHCPOpt = 40 // n, string + DHCPOptNISServers DHCPOpt = 41 // 4*n, [n]net.IP + DHCPOptNTPServers DHCPOpt = 42 // 4*n, [n]net.IP + DHCPOptVendorOption DHCPOpt = 43 // n, [n]byte // may be encapsulated. + DHCPOptNetBIOSTCPNS DHCPOpt = 44 // 4*n, [n]net.IP + DHCPOptNetBIOSTCPDDS DHCPOpt = 45 // 4*n, [n]net.IP + DHCPOptNETBIOSTCPNodeType DHCPOpt = 46 // 1, magic byte + DHCPOptNetBIOSTCPScope DHCPOpt = 47 // n, string + DHCPOptXFontServer DHCPOpt = 48 // n, string + DHCPOptXDisplayManager DHCPOpt = 49 // n, string + DHCPOptRequestIP DHCPOpt = 50 // 4, net.IP + DHCPOptLeaseTime DHCPOpt = 51 // 4, uint32 + DHCPOptExtOptions DHCPOpt = 52 // 1, 1/2/3 + DHCPOptMessageType DHCPOpt = 53 // 1, 1-7 + DHCPOptServerID DHCPOpt = 54 // 4, net.IP + DHCPOptParamsRequest DHCPOpt = 55 // n, []byte + DHCPOptMessage DHCPOpt = 56 // n, 3 + DHCPOptMaxMessageSize DHCPOpt = 57 // 2, uint16 + DHCPOptT1 DHCPOpt = 58 // 4, uint32 + DHCPOptT2 DHCPOpt = 59 // 4, uint32 + DHCPOptClassID DHCPOpt = 60 // n, []byte + DHCPOptClientID DHCPOpt = 61 // n >= 2, []byte + DHCPOptDomainSearch DHCPOpt = 119 // n, string + DHCPOptSIPServers DHCPOpt = 120 // n, url + DHCPOptClasslessStaticRoute DHCPOpt = 121 // + DHCPOptEnd DHCPOpt = 255 +) + +// String returns a string version of a DHCPOpt. +func (o DHCPOpt) String() string { + switch o { + case DHCPOptPad: + return "(padding)" + case DHCPOptSubnetMask: + return "SubnetMask" + case DHCPOptTimeOffset: + return "TimeOffset" + case DHCPOptRouter: + return "Router" + case DHCPOptTimeServer: + return "rfc868" // old time server protocol stringified to dissuade confusion w. NTP + case DHCPOptNameServer: + return "ien116" // obscure nameserver protocol stringified to dissuade confusion w. DNS + case DHCPOptDNS: + return "DNS" + case DHCPOptLogServer: + return "mitLCS" // MIT LCS server protocol yada yada w. Syslog + case DHCPOptCookieServer: + return "CookieServer" + case DHCPOptLPRServer: + return "LPRServer" + case DHCPOptImpressServer: + return "ImpressServer" + case DHCPOptResLocServer: + return "ResourceLocationServer" + case DHCPOptHostname: + return "Hostname" + case DHCPOptBootfileSize: + return "BootfileSize" + case DHCPOptMeritDumpFile: + return "MeritDumpFile" + case DHCPOptDomainName: + return "DomainName" + case DHCPOptSwapServer: + return "SwapServer" + case DHCPOptRootPath: + return "RootPath" + case DHCPOptExtensionsPath: + return "ExtensionsPath" + case DHCPOptIPForwarding: + return "IPForwarding" + case DHCPOptSourceRouting: + return "SourceRouting" + case DHCPOptPolicyFilter: + return "PolicyFilter" + case DHCPOptDatagramMTU: + return "DatagramMTU" + case DHCPOptDefaultTTL: + return "DefaultTTL" + case DHCPOptPathMTUAgingTimeout: + return "PathMTUAgingTimeout" + case DHCPOptPathPlateuTableOption: + return "PathPlateuTableOption" + case DHCPOptInterfaceMTU: + return "InterfaceMTU" + case DHCPOptAllSubsLocal: + return "AllSubsLocal" + case DHCPOptBroadcastAddr: + return "BroadcastAddress" + case DHCPOptMaskDiscovery: + return "MaskDiscovery" + case DHCPOptMaskSupplier: + return "MaskSupplier" + case DHCPOptRouterDiscovery: + return "RouterDiscovery" + case DHCPOptSolicitAddr: + return "SolicitAddr" + case DHCPOptStaticRoute: + return "StaticRoute" + case DHCPOptARPTrailers: + return "ARPTrailers" + case DHCPOptARPTimeout: + return "ARPTimeout" + case DHCPOptEthernetEncap: + return "EthernetEncap" + case DHCPOptTCPTTL: + return "TCPTTL" + case DHCPOptTCPKeepAliveInt: + return "TCPKeepAliveInt" + case DHCPOptTCPKeepAliveGarbage: + return "TCPKeepAliveGarbage" + case DHCPOptNISDomain: + return "NISDomain" + case DHCPOptNISServers: + return "NISServers" + case DHCPOptNTPServers: + return "NTPServers" + case DHCPOptVendorOption: + return "VendorOption" + case DHCPOptNetBIOSTCPNS: + return "NetBIOSOverTCPNS" + case DHCPOptNetBIOSTCPDDS: + return "NetBiosOverTCPDDS" + case DHCPOptNETBIOSTCPNodeType: + return "NetBIOSOverTCPNodeType" + case DHCPOptNetBIOSTCPScope: + return "NetBIOSOverTCPScope" + case DHCPOptXFontServer: + return "XFontServer" + case DHCPOptXDisplayManager: + return "XDisplayManager" + case DHCPOptEnd: + return "(end)" + case DHCPOptSIPServers: + return "SipServers" + case DHCPOptRequestIP: + return "RequestIP" + case DHCPOptLeaseTime: + return "LeaseTime" + case DHCPOptExtOptions: + return "ExtOpts" + case DHCPOptMessageType: + return "MessageType" + case DHCPOptServerID: + return "ServerID" + case DHCPOptParamsRequest: + return "ParamsRequest" + case DHCPOptMessage: + return "Message" + case DHCPOptMaxMessageSize: + return "MaxDHCPSize" + case DHCPOptT1: + return "Timer1" + case DHCPOptT2: + return "Timer2" + case DHCPOptClassID: + return "ClassID" + case DHCPOptClientID: + return "ClientID" + case DHCPOptDomainSearch: + return "DomainSearch" + case DHCPOptClasslessStaticRoute: + return "ClasslessStaticRoute" + default: + return "Unknown" + } +} + +// DHCPOption rerpresents a DHCP option. +type DHCPOption struct { + Type DHCPOpt + Length uint8 + Data []byte +} + +// String returns a string version of a DHCP Option. +func (o DHCPOption) String() string { + switch o.Type { + + case DHCPOptHostname, DHCPOptMeritDumpFile, DHCPOptDomainName, DHCPOptRootPath, + DHCPOptExtensionsPath, DHCPOptNISDomain, DHCPOptNetBIOSTCPScope, DHCPOptXFontServer, + DHCPOptXDisplayManager, DHCPOptMessage, DHCPOptDomainSearch: // string + return fmt.Sprintf("Option(%s:%s)", o.Type, string(o.Data)) + + case DHCPOptMessageType: + if len(o.Data) != 1 { + return fmt.Sprintf("Option(%s:INVALID)", o.Type) + } + return fmt.Sprintf("Option(%s:%s)", o.Type, DHCPMsgType(o.Data[0])) + + case DHCPOptSubnetMask, DHCPOptServerID, DHCPOptBroadcastAddr, + DHCPOptSolicitAddr, DHCPOptRequestIP: // net.IP + if len(o.Data) < 4 { + return fmt.Sprintf("Option(%s:INVALID)", o.Type) + } + return fmt.Sprintf("Option(%s:%s)", o.Type, net.IP(o.Data)) + + case DHCPOptT1, DHCPOptT2, DHCPOptLeaseTime, DHCPOptPathMTUAgingTimeout, + DHCPOptARPTimeout, DHCPOptTCPKeepAliveInt: // uint32 + if len(o.Data) != 4 { + return fmt.Sprintf("Option(%s:INVALID)", o.Type) + } + return fmt.Sprintf("Option(%s:%d)", o.Type, + uint32(o.Data[0])<<24|uint32(o.Data[1])<<16|uint32(o.Data[2])<<8|uint32(o.Data[3])) + + case DHCPOptParamsRequest: + buf := &bytes.Buffer{} + buf.WriteString(fmt.Sprintf("Option(%s:", o.Type)) + for i, v := range o.Data { + buf.WriteString(DHCPOpt(v).String()) + if i+1 != len(o.Data) { + buf.WriteByte(',') + } + } + buf.WriteString(")") + return buf.String() + + default: + return fmt.Sprintf("Option(%s:%v)", o.Type, o.Data) + } +} + +// NewDHCPOption constructs a new DHCPOption with a given type and data. +func NewDHCPOption(t DHCPOpt, data []byte) DHCPOption { + o := DHCPOption{Type: t} + if data != nil { + o.Data = data + o.Length = uint8(len(data)) + } + return o +} + +func (o *DHCPOption) encode(b []byte) error { + switch o.Type { + case DHCPOptPad, DHCPOptEnd: + b[0] = byte(o.Type) + default: + if o.Length > 253 { + return errors.New("data too long to encode") + } + b[0] = byte(o.Type) + b[1] = o.Length + copy(b[2:], o.Data) + } + return nil +} + +func (o *DHCPOption) decode(data []byte) error { + if len(data) < 1 { + // Pad/End have a length of 1 + return errors.New("Not enough data to decode") + } + o.Type = DHCPOpt(data[0]) + switch o.Type { + case DHCPOptPad, DHCPOptEnd: + o.Data = nil + default: + if len(data) < 3 { + return errors.New("Not enough data to decode") + } + o.Length = data[1] + if o.Length > 253 { + return errors.New("data too long to decode") + } + o.Data = data[2 : 2+o.Length] + } + return nil +} -- cgit 1.2.3-korg