DIRECTORY Basics USING [BITAND, BITOR, Card16FromH, FWORD, HFromCard16, HWORD], CommBuffer USING [Overhead], Arpa USING [Address]; ArpaBuf: CEDAR DEFINITIONS IMPORTS Basics ~ { HWORD: TYPE ~ Basics.HWORD; FWORD: TYPE ~ Basics.FWORD; maxBytes: CARDINAL ~ 1500; Version: TYPE ~ CARDINAL [0..0FH]; thisVersion: Version ~ 4; IHL: TYPE ~ CARDINAL [0..0FH]; minIHL: IHL ~ 5; IHLBytes: PROC [b: Buffer] RETURNS [CARD16] ~ INLINE { RETURN[b.hdr1.ihl * 4] }; maxOptionsBytes: CARDINAL = 4 * (IHL.LAST - minIHL); OptionsBytes: PROC [b: Buffer] RETURNS [CARD16] ~ INLINE { RETURN[(b.hdr1.ihl * 4) - hdrBytes] }; DataBytes: PROC [b: Buffer] RETURNS [CARD16] ~ INLINE { RETURN[Basics.Card16FromH[b.hdr1.length] - (b.hdr1.ihl * 4)] }; FragmentCtl: TYPE ~ HWORD; defaultFragmentCtl: FragmentCtl ~ [0, 0]; defaultFragmentCtlDontFragment: FragmentCtl ~ [40H, 0]; dontFragmentMask: FragmentCtl ~ [40H, 0]; moreFragmentsMask: FragmentCtl ~ [20H, 0]; fragmentOffsetMask: FragmentCtl ~ [1FH, 0FFH]; DontFragment: PROC [b: Buffer] RETURNS [BOOL] ~ INLINE { RETURN [ Basics.BITAND[LOOPHOLE[b.hdr1.fragmentCtl], LOOPHOLE[dontFragmentMask]] # 0]; }; MoreFragments: PROC [b: Buffer] RETURNS [BOOL] ~ INLINE { RETURN [ Basics.BITAND[LOOPHOLE[b.hdr1.fragmentCtl], LOOPHOLE[moreFragmentsMask]] # 0]; }; FragmentOffset: PROC [b: Buffer] RETURNS [CARD16] ~ INLINE { RETURN[Basics.Card16FromH[LOOPHOLE[Basics.BITAND[LOOPHOLE[b.hdr1.fragmentCtl], LOOPHOLE[fragmentOffsetMask]]]]]; }; FragmentOffsetBytes: PROC [b: Buffer] RETURNS [CARD16] ~ INLINE { RETURN[8*Basics.Card16FromH[LOOPHOLE[Basics.BITAND[LOOPHOLE[b.hdr1.fragmentCtl], LOOPHOLE[fragmentOffsetMask]]]]]; }; InteriorFragmentCtl: PROC [byteOffset: CARD16] RETURNS [HWORD] ~ INLINE { RETURN [LOOPHOLE[Basics.BITOR[LOOPHOLE[moreFragmentsMask], LOOPHOLE[Basics.HFromCard16[byteOffset/8]]]] ] }; FinalFragmentCtl: PROC [byteOffset: CARD16] RETURNS [HWORD] ~ INLINE { RETURN [Basics.HFromCard16[byteOffset/8]] }; TypeOfService: TYPE ~ MACHINE DEPENDENT RECORD [ precedence: Precedence, lowDelay: BOOL, highThroughput: BOOL, highReliability: BOOL, filler0: BOOL, filler1: BOOL ]; defaultTypeOfService: TypeOfService ~ [routine, FALSE, FALSE, FALSE, FALSE, FALSE]; Precedence: TYPE ~ MACHINE DEPENDENT { routine(0), priority(1), immediate(2), flash(3), flashOverride(4), critECP(5), inetCtl(6), netCtl(7) }; maxTimeToLive: BYTE ~ 60; Protocol: TYPE ~ MACHINE DEPENDENT { icmp(1), -- Internet Control Message Protocol igmp(2), -- Internet Group Management Protocol tcp(6), -- Transmission Control Protocol egp(8), -- Exterior Gateway Protocol igp(9), -- Interior Gateway pup(12), -- PUP udp(17), -- User Datagram Protocol xnsidp(22), -- XNS Internet Datagram Packet isotp4(29), -- ISO Transport Protocol Class 4 netblt(30), -- Bulk Data Transfer Protocol last(0FFH) }; Hdr: TYPE ~ MACHINE DEPENDENT RECORD [ version: Version _ thisVersion, ihl: IHL _ minIHL, typeOfService: TypeOfService _ defaultTypeOfService, length: HWORD, fragmentId: HWORD _ [0, 0], fragmentCtl: FragmentCtl _ defaultFragmentCtl, timeToLive: BYTE, protocol: Protocol, checksum: HWORD _ [0, 0], source: Arpa.Address, dest: Arpa.Address]; hdrBytes: CARDINAL ~ BYTES[Hdr]; Body: TYPE ~ MACHINE DEPENDENT RECORD [ SELECT OVERLAID * FROM bytes => [bytes: PACKED ARRAY [0..maxBodyBytes) OF BYTE], chars => [chars: PACKED ARRAY [0..maxBodyChars) OF CHAR], hWords => [hWords: PACKED ARRAY [0..maxBodyHWords) OF HWORD], fWords => [fWords: PACKED ARRAY [0..maxBodyFWords) OF FWORD] ENDCASE ]; maxBodyBytes: CARDINAL ~ maxBytes - hdrBytes; maxBodyChars: CARDINAL ~ maxBodyBytes; maxBodyHWords: CARDINAL ~ maxBodyBytes/BYTES[HWORD]; maxBodyFWords: CARDINAL ~ maxBodyBytes/BYTES[FWORD]; Packet: TYPE ~ REF PacketObject; PacketObject: TYPE ~ MACHINE DEPENDENT RECORD [ hdr: Hdr, body: Body]; Buffer: TYPE ~ REF BufferObject; BufferObject: TYPE ~ MACHINE DEPENDENT RECORD [ ovh: CommBuffer.Overhead, hdr1: Hdr, body: Body]; OptionType: TYPE ~ MACHINE DEPENDENT RECORD [ mustBeCopied: BOOL, class: [0..3B], number: OptionNumber ]; OptionNumber: TYPE ~ MACHINE DEPENDENT { endOfList(0), noOp(1), security(2), looseSourceRouting(3), timestamp(4), recordRoute(7), streamID(8), strictSourceRouting(9), last(37B) }; Option: TYPE ~ MACHINE DEPENDENT RECORD [ type: OptionType, length: BYTE ]; variableLength: BYTE ~ 0; endOfListOption: Option ~ [[FALSE, 0, endOfList], 1]; -- no length field! noOpOption: Option ~ [[FALSE, 0, noOp], 1]; -- no length field! securityOption: Option ~ [[TRUE, 0, security], 11]; looseSourceRoutingOption: Option ~ [[TRUE, 0, looseSourceRouting], variableLength]; timestampOption: Option ~ [[FALSE, 2, timestamp], variableLength]; recordRouteOption: Option ~ [[FALSE, 0, recordRoute], variableLength]; streamIDOption: Option ~ [[FALSE, 0, streamID], 4]; strictSourceRoutingOption: Option ~ [[TRUE, 0, strictSourceRouting], variableLength]; }. (ArpaBuf.mesa Copyright ╙ 1987 by Xerox Corporation. All rights reserved. Demers, August 27, 1987 0:53:28 am PDT Format for Arpa IP packets. Maximum Packet Size May be no less than 576 and no greater than CommDriver.dataBytesInBuffer. Header Return number of bytes in internet header, counting options. Return number of bytes of options in IP Hdr. Return number of bytes of data in IP Body. Masks for use against FragmentCtl Result is the offset in 8-byte chunks from the beginning of the datagram, not counting the header. Result is the offset in bytes from the beginning of the datagram, not counting the header. The offset is in bytes from the beginning of the datagram, not counting the header. The offset is in bytes from the beginning of the datagram, not counting the header. Body Packet Buffer All buffers start out as CommDriver.Buffer's. Clients may SmashType between CommDriver.Buffer and ArpaBuf.Buffer, so the "right" module gets to do finalization. This is VERY delicate. Options These appear in CommBuffer.BufferObject.spaceForOptions. Э╩╢ШcodeЪЬЩKЩ