<> <> <> <<>> <> <<>> DIRECTORY Basics USING [FWORD, HWORD], CommBuffer USING [Overhead], Arpa USING [Address]; ArpaBuf: CEDAR DEFINITIONS ~ { 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; FragmentCtl: TYPE ~ HWORD; defaultFragmentCtl: FragmentCtl ~ [0, 0]; <> dontFragmentMask: HWORD ~ [04H, 0H]; moreFragmentsMask: HWORD ~ [02H, 0H]; fragmentOffsetMask: HWORD ~ [01FH, 0FFH]; 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) }; 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]; <<>> }.