package dhcpv4 import ( "fmt" ) // values from http://www.networksorcery.com/enp/protocol/dhcp.htm and // http://www.networksorcery.com/enp/protocol/bootp/options.htm // TransactionID represents a 4-byte DHCP transaction ID as defined in RFC 951, // Section 3. // // The TransactionID is used to match DHCP replies to their original request. type TransactionID [4]byte // String prints a hex transaction ID. func (xid TransactionID) String() string { return fmt.Sprintf("0x%x", xid[:]) } // MessageType represents the possible DHCP message types - DISCOVER, OFFER, etc type MessageType byte // DHCP message types const ( // MessageTypeNone is not a real message type, it is used by certain // functions to signal that no explicit message type is requested MessageTypeNone MessageType = 0 MessageTypeDiscover MessageType = 1 MessageTypeOffer MessageType = 2 MessageTypeRequest MessageType = 3 MessageTypeDecline MessageType = 4 MessageTypeAck MessageType = 5 MessageTypeNak MessageType = 6 MessageTypeRelease MessageType = 7 MessageTypeInform MessageType = 8 ) func (m MessageType) String() string { if s, ok := messageTypeToString[m]; ok { return s } return fmt.Sprintf("unknown (%d)", byte(m)) } var messageTypeToString = map[MessageType]string{ MessageTypeDiscover: "DISCOVER", MessageTypeOffer: "OFFER", MessageTypeRequest: "REQUEST", MessageTypeDecline: "DECLINE", MessageTypeAck: "ACK", MessageTypeNak: "NAK", MessageTypeRelease: "RELEASE", MessageTypeInform: "INFORM", } // OpcodeType represents a DHCPv4 opcode. type OpcodeType uint8 // constants that represent valid values for OpcodeType const ( OpcodeBootRequest OpcodeType = 1 OpcodeBootReply OpcodeType = 2 ) func (o OpcodeType) String() string { if s, ok := opcodeToString[o]; ok { return s } return fmt.Sprintf("unknown (%d)", uint8(o)) } var opcodeToString = map[OpcodeType]string{ OpcodeBootRequest: "BootRequest", OpcodeBootReply: "BootReply", } // OptionCode is a single byte representing the code for a given Option. // // OptionCode is an interface purely to support different stringers on options // with the same Code value, as vendor-specific options use option codes that // have the same value, but mean a different thing. type OptionCode interface { Code() uint8 String() string } // optionCode is a DHCP option code. type optionCode uint8 func (o optionCode) Code() uint8 { return uint8(o) } func (o optionCode) String() string { if s, ok := optionCodeToString[o]; ok { return s } return fmt.Sprintf("unknown (%d)", o) } // DHCPv4 Options const ( OptionPad optionCode = 0 OptionSubnetMask optionCode = 1 OptionTimeOffset optionCode = 2 OptionRouter optionCode = 3 OptionTimeServer optionCode = 4 OptionNameServer optionCode = 5 OptionDomainNameServer optionCode = 6 OptionLogServer optionCode = 7 OptionQuoteServer optionCode = 8 OptionLPRServer optionCode = 9 OptionImpressServer optionCode = 10 OptionResourceLocationServer optionCode = 11 OptionHostName optionCode = 12 OptionBootFileSize optionCode = 13 OptionMeritDumpFile optionCode = 14 OptionDomainName optionCode = 15 OptionSwapServer optionCode = 16 OptionRootPath optionCode = 17 OptionExtensionsPath optionCode = 18 OptionIPForwarding optionCode = 19 OptionNonLocalSourceRouting optionCode = 20 OptionPolicyFilter optionCode = 21 OptionMaximumDatagramAssemblySize optionCode = 22 OptionDefaultIPTTL optionCode = 23 OptionPathMTUAgingTimeout optionCode = 24 OptionPathMTUPlateauTable optionCode = 25 OptionInterfaceMTU optionCode = 26 OptionAllSubnetsAreLocal optionCode = 27 OptionBroadcastAddress optionCode = 28 OptionPerformMaskDiscovery optionCode = 29 OptionMaskSupplier optionCode = 30 OptionPerformRouterDiscovery optionCode = 31 OptionRouterSolicitationAddress optionCode = 32 OptionStaticRoutingTable optionCode = 33 OptionTrailerEncapsulation optionCode = 34 OptionArpCacheTimeout optionCode = 35 OptionEthernetEncapsulation optionCode = 36 OptionDefaulTCPTTL optionCode = 37 OptionTCPKeepaliveInterval optionCode = 38 OptionTCPKeepaliveGarbage optionCode = 39 OptionNetworkInformationServiceDomain optionCode = 40 OptionNetworkInformationServers optionCode = 41 OptionNTPServers optionCode = 42 OptionVendorSpecificInformation optionCode = 43 OptionNetBIOSOverTCPIPNameServer optionCode = 44 OptionNetBIOSOverTCPIPDatagramDistributionServer optionCode = 45 OptionNetBIOSOverTCPIPNodeType optionCode = 46 OptionNetBIOSOverTCPIPScope optionCode = 47 OptionXWindowSystemFontServer optionCode = 48 OptionXWindowSystemDisplayManger optionCode = 49 OptionRequestedIPAddress optionCode = 50 OptionIPAddressLeaseTime optionCode = 51 OptionOptionOverload optionCode = 52 OptionDHCPMessageType optionCode = 53 OptionServerIdentifier optionCode = 54 OptionParameterRequestList optionCode = 55 OptionMessage optionCode = 56 OptionMaximumDHCPMessageSize optionCode = 57 OptionRenewTimeValue optionCode = 58 OptionRebindingTimeValue optionCode = 59 OptionClassIdentifier optionCode = 60 OptionClientIdentifier optionCode = 61 OptionNetWareIPDomainName optionCode = 62 OptionNetWareIPInformation optionCode = 63 OptionNetworkInformationServicePlusDomain optionCode = 64 OptionNetworkInformationServicePlusServers optionCode = 65 OptionTFTPServerName optionCode = 66 OptionBootfileName optionCode = 67 OptionMobileIPHomeAgent optionCode = 68 OptionSimpleMailTransportProtocolServer optionCode = 69 OptionPostOfficeProtocolServer optionCode = 70 OptionNetworkNewsTransportProtocolServer optionCode = 71 OptionDefaultWorldWideWebServer optionCode = 72 OptionDefaultFingerServer optionCode = 73 OptionDefaultInternetRelayChatServer optionCode = 74 OptionStreetTalkServer optionCode = 75 OptionStreetTalkDirectoryAssistanceServer optionCode = 76 OptionUserClassInformation optionCode = 77 OptionSLPDirectoryAgent optionCode = 78 OptionSLPServiceScope optionCode = 79 OptionRapidCommit optionCode = 80 OptionFQDN optionCode = 81 OptionRelayAgentInformation optionCode = 82 OptionInternetStorageNameService optionCode = 83 // Option 84 returned in RFC 3679 OptionNDSServers optionCode = 85 OptionNDSTreeName optionCode = 86 OptionNDSContext optionCode = 87 OptionBCMCSControllerDomainNameList optionCode = 88 OptionBCMCSControllerIPv4AddressList optionCode = 89 OptionAuthentication optionCode = 90 OptionClientLastTransactionTime optionCode = 91 OptionAssociatedIP optionCode = 92 OptionClientSystemArchitectureType optionCode = 93 OptionClientNetworkInterfaceIdentifier optionCode = 94 OptionLDAP optionCode = 95 // Option 96 returned in RFC 3679 OptionClientMachineIdentifier optionCode = 97 OptionOpenGroupUserAuthentication optionCode = 98 OptionGeoConfCivic optionCode = 99 OptionIEEE10031TZString optionCode = 100 OptionReferenceToTZDatabase optionCode = 101 // Options 102-111 returned in RFC 3679 OptionNetInfoParentServerAddress optionCode = 112 OptionNetInfoParentServerTag optionCode = 113 OptionURL optionCode = 114 // Option 115 returned in RFC 3679 OptionAutoConfigure optionCode = 116 OptionNameServiceSearch optionCode = 117 OptionSubnetSelection optionCode = 118 OptionDNSDomainSearchList optionCode = 119 OptionSIPServersDHCPOption optionCode = 120 OptionClasslessStaticRouteOption optionCode = 121 OptionCCC optionCode = 122 OptionGeoConf optionCode = 123 OptionVendorIdentifyingVendorClass optionCode = 124 OptionVendorIdentifyingVendorSpecific optionCode = 125 // Options 126-127 returned in RFC 3679 OptionTFTPServerIPAddress optionCode = 128 OptionCallServerIPAddress optionCode = 129 OptionDiscriminationString optionCode = 130 OptionRemoteStatisticsServerIPAddress optionCode = 131 Option8021PVLANID optionCode = 132 Option8021QL2Priority optionCode = 133 OptionDiffservCodePoint optionCode = 134 OptionHTTPProxyForPhoneSpecificApplications optionCode = 135 OptionPANAAuthenticationAgent optionCode = 136 OptionLoSTServer optionCode = 137 OptionCAPWAPAccessControllerAddresses optionCode = 138 OptionOPTIONIPv4AddressMoS optionCode = 139 OptionOPTIONIPv4FQDNMoS optionCode = 140 OptionSIPUAConfigurationServiceDomains optionCode = 141 OptionOPTIONIPv4AddressANDSF optionCode = 142 OptionOPTIONIPv6AddressANDSF optionCode = 143 // Options 144-149 returned in RFC 3679 OptionTFTPServerAddress optionCode = 150 OptionStatusCode optionCode = 151 OptionBaseTime optionCode = 152 OptionStartTimeOfState optionCode = 153 OptionQueryStartTime optionCode = 154 OptionQueryEndTime optionCode = 155 OptionDHCPState optionCode = 156 OptionDataSource optionCode = 157 // Options 158-174 returned in RFC 3679 OptionEtherboot optionCode = 175 OptionIPTelephone optionCode = 176 OptionEtherbootPacketCableAndCableHome optionCode = 177 // Options 178-207 returned in RFC 3679 OptionPXELinuxMagicString optionCode = 208 OptionPXELinuxConfigFile optionCode = 209 OptionPXELinuxPathPrefix optionCode = 210 OptionPXELinuxRebootTime optionCode = 211 OptionOPTION6RD optionCode = 212 OptionOPTIONv4AccessDomain optionCode = 213 // Options 214-219 returned in RFC 3679 OptionSubnetAllocation optionCode = 220 OptionVirtualSubnetAllocation optionCode = 221 // Options 222-223 returned in RFC 3679 // Options 224-254 are reserved for private use OptionEnd optionCode = 255 ) var optionCodeToString = map[optionCode]string{ OptionPad: "Pad", OptionSubnetMask: "Subnet Mask", OptionTimeOffset: "Time Offset", OptionRouter: "Router", OptionTimeServer: "Time Server", OptionNameServer: "Name Server", OptionDomainNameServer: "Domain Name Server", OptionLogServer: "Log Server", OptionQuoteServer: "Quote Server", OptionLPRServer: "LPR Server", OptionImpressServer: "Impress Server", OptionResourceLocationServer: "Resource Location Server", OptionHostName: "Host Name", OptionBootFileSize: "Boot File Size", OptionMeritDumpFile: "Merit Dump File", OptionDomainName: "Domain Name", OptionSwapServer: "Swap Server", OptionRootPath: "Root Path", OptionExtensionsPath: "Extensions Path", OptionIPForwarding: "IP Forwarding enable/disable", OptionNonLocalSourceRouting: "Non-local Source Routing enable/disable", OptionPolicyFilter: "Policy Filter", OptionMaximumDatagramAssemblySize: "Maximum Datagram Reassembly Size", OptionDefaultIPTTL: "Default IP Time-to-live", OptionPathMTUAgingTimeout: "Path MTU Aging Timeout", OptionPathMTUPlateauTable: "Path MTU Plateau Table", OptionInterfaceMTU: "Interface MTU", OptionAllSubnetsAreLocal: "All Subnets Are Local", OptionBroadcastAddress: "Broadcast Address", OptionPerformMaskDiscovery: "Perform Mask Discovery", OptionMaskSupplier: "Mask Supplier", OptionPerformRouterDiscovery: "Perform Router Discovery", OptionRouterSolicitationAddress: "Router Solicitation Address", OptionStaticRoutingTable: "Static Routing Table", OptionTrailerEncapsulation: "Trailer Encapsulation", OptionArpCacheTimeout: "ARP Cache Timeout", OptionEthernetEncapsulation: "Ethernet Encapsulation", OptionDefaulTCPTTL: "Default TCP TTL", OptionTCPKeepaliveInterval: "TCP Keepalive Interval", OptionTCPKeepaliveGarbage: "TCP Keepalive Garbage", OptionNetworkInformationServiceDomain: "Network Information Service Domain", OptionNetworkInformationServers: "Network Information Servers", OptionNTPServers: "NTP Servers", OptionVendorSpecificInformation: "Vendor Specific Information", OptionNetBIOSOverTCPIPNameServer: "NetBIOS over TCP/IP Name Server", OptionNetBIOSOverTCPIPDatagramDistributionServer: "NetBIOS over TCP/IP Datagram Distribution Server", OptionNetBIOSOverTCPIPNodeType: "NetBIOS over TCP/IP Node Type", OptionNetBIOSOverTCPIPScope: "NetBIOS over TCP/IP Scope", OptionXWindowSystemFontServer: "X Window System Font Server", OptionXWindowSystemDisplayManger: "X Window System Display Manager", OptionRequestedIPAddress: "Requested IP Address", OptionIPAddressLeaseTime: "IP Addresses Lease Time", OptionOptionOverload: "Option Overload", OptionDHCPMessageType: "DHCP Message Type", OptionServerIdentifier: "Server Identifier", OptionParameterRequestList: "Parameter Request List", OptionMessage: "Message", OptionMaximumDHCPMessageSize: "Maximum DHCP Message Size", OptionRenewTimeValue: "Renew Time Value", OptionRebindingTimeValue: "Rebinding Time Value", OptionClassIdentifier: "Class Identifier", OptionClientIdentifier: "Client identifier", OptionNetWareIPDomainName: "NetWare/IP Domain Name", OptionNetWareIPInformation: "NetWare/IP Information", OptionNetworkInformationServicePlusDomain: "Network Information Service+ Domain", OptionNetworkInformationServicePlusServers: "Network Information Service+ Servers", OptionTFTPServerName: "TFTP Server Name", OptionBootfileName: "Bootfile Name", OptionMobileIPHomeAgent: "Mobile IP Home Agent", OptionSimpleMailTransportProtocolServer: "SMTP Server", OptionPostOfficeProtocolServer: "POP Server", OptionNetworkNewsTransportProtocolServer: "NNTP Server", OptionDefaultWorldWideWebServer: "Default WWW Server", OptionDefaultFingerServer: "Default Finger Server", OptionDefaultInternetRelayChatServer: "Default IRC Server", OptionStreetTalkServer: "StreetTalk Server", OptionStreetTalkDirectoryAssistanceServer: "StreetTalk Directory Assistance Server", OptionUserClassInformation: "User Class Information", OptionSLPDirectoryAgent: "SLP DIrectory Agent", OptionSLPServiceScope: "SLP Service Scope", OptionRapidCommit: "Rapid Commit", OptionFQDN: "FQDN", OptionRelayAgentInformation: "Relay Agent Information", OptionInternetStorageNameService: "Internet Storage Name Service", // Option 84 returned in RFC 3679 OptionNDSServers: "NDS Servers", OptionNDSTreeName: "NDS Tree Name", OptionNDSContext: "NDS Context", OptionBCMCSControllerDomainNameList: "BCMCS Controller Domain Name List", OptionBCMCSControllerIPv4AddressList: "BCMCS Controller IPv4 Address List", OptionAuthentication: "Authentication", OptionClientLastTransactionTime: "Client Last Transaction Time", OptionAssociatedIP: "Associated IP", OptionClientSystemArchitectureType: "Client System Architecture Type", OptionClientNetworkInterfaceIdentifier: "Client Network Interface Identifier", OptionLDAP: "LDAP", // Option 96 returned in RFC 3679 OptionClientMachineIdentifier: "Client Machine Identifier", OptionOpenGroupUserAuthentication: "OpenGroup's User Authentication", OptionGeoConfCivic: "GEOCONF_CIVIC", OptionIEEE10031TZString: "IEEE 1003.1 TZ String", OptionReferenceToTZDatabase: "Reference to the TZ Database", // Options 102-111 returned in RFC 3679 OptionNetInfoParentServerAddress: "NetInfo Parent Server Address", OptionNetInfoParentServerTag: "NetInfo Parent Server Tag", OptionURL: "URL", // Option 115 returned in RFC 3679 OptionAutoConfigure: "Auto-Configure", OptionNameServiceSearch: "Name Service Search", OptionSubnetSelection: "Subnet Selection", OptionDNSDomainSearchList: "DNS Domain Search List", OptionSIPServersDHCPOption: "SIP Servers DHCP Option", OptionClasslessStaticRouteOption: "Classless Static Route Option", OptionCCC: "CCC, CableLabs Client Configuration", OptionGeoConf: "GeoConf", OptionVendorIdentifyingVendorClass: "Vendor-Identifying Vendor Class", OptionVendorIdentifyingVendorSpecific: "Vendor-Identifying Vendor-Specific", // Options 126-127 returned in RFC 3679 OptionTFTPServerIPAddress: "TFTP Server IP Address", OptionCallServerIPAddress: "Call Server IP Address", OptionDiscriminationString: "Discrimination String", OptionRemoteStatisticsServerIPAddress: "RemoteStatistics Server IP Address", Option8021PVLANID: "802.1P VLAN ID", Option8021QL2Priority: "802.1Q L2 Priority", OptionDiffservCodePoint: "Diffserv Code Point", OptionHTTPProxyForPhoneSpecificApplications: "HTTP Proxy for phone-specific applications", OptionPANAAuthenticationAgent: "PANA Authentication Agent", OptionLoSTServer: "LoST Server", OptionCAPWAPAccessControllerAddresses: "CAPWAP Access Controller Addresses", OptionOPTIONIPv4AddressMoS: "OPTION-IPv4_Address-MoS", OptionOPTIONIPv4FQDNMoS: "OPTION-IPv4_FQDN-MoS", OptionSIPUAConfigurationServiceDomains: "SIP UA Configuration Service Domains", OptionOPTIONIPv4AddressANDSF: "OPTION-IPv4_Address-ANDSF", OptionOPTIONIPv6AddressANDSF: "OPTION-IPv6_Address-ANDSF", // Options 144-149 returned in RFC 3679 OptionTFTPServerAddress: "TFTP Server Address", OptionStatusCode: "Status Code", OptionBaseTime: "Base Time", OptionStartTimeOfState: "Start Time of State", OptionQueryStartTime: "Query Start Time", OptionQueryEndTime: "Query End Time", OptionDHCPState: "DHCP Staet", OptionDataSource: "Data Source", // Options 158-174 returned in RFC 3679 OptionEtherboot: "Etherboot", OptionIPTelephone: "IP Telephone", OptionEtherbootPacketCableAndCableHome: "Etherboot / PacketCable and CableHome", // Options 178-207 returned in RFC 3679 OptionPXELinuxMagicString: "PXELinux Magic String", OptionPXELinuxConfigFile: "PXELinux Config File", OptionPXELinuxPathPrefix: "PXELinux Path Prefix", OptionPXELinuxRebootTime: "PXELinux Reboot Time", OptionOPTION6RD: "OPTION_6RD", OptionOPTIONv4AccessDomain: "OPTION_V4_ACCESS_DOMAIN", // Options 214-219 returned in RFC 3679 OptionSubnetAllocation: "Subnet Allocation", OptionVirtualSubnetAllocation: "Virtual Subnet Selection", // Options 222-223 returned in RFC 3679 // Options 224-254 are reserved for private use OptionEnd: "End", }