-- Copyright (C) 1983, 1985 by Xerox Corporation. All rights reserved.
-- LocalNameConversion.mesa, HGM, 6-Jul-85 11:01:30
DIRECTORY
Mopcodes USING [zEXCH],
String USING [AppendChar, AppendString, AppendLongNumber, AppendOctal],
Buffer USING [AccessHandle, DestroyPool, GetBuffer, MakePool, ReturnBuffer],
Driver USING [Glitch],
PupDefs USING [
NameLookupErrorCode, DataWordsPerPupBuffer,
GetPupContentsBytes, SetPupContentsWords,
SetPupContentsBytes, UniqueLocalPupAddress, PupRouterBroadcastThis,
PupAddress, PupBuffer, PupSocket, PupSocketDestroy, PupSocketMake,
SecondsToTocks],
PupRouterDefs USING [GetRoutingTableEntry, RoutingTableEntry],
PupStream USING [],
PupTypes USING [fillInSocketID, miscSrvSoc, PupSocketID];
LocalNameConversion: PROGRAM
IMPORTS String, Buffer, Driver, PupDefs, PupRouterDefs EXPORTS PupStream, PupDefs =
BEGIN OPEN PupDefs;
PupNameTrouble: PUBLIC ERROR [e: LONG STRING, code: NameLookupErrorCode] = CODE;
StringIsNIL: PUBLIC ERROR = CODE;
StringTooLong: PUBLIC ERROR = CODE;
GetPupAddress: PUBLIC PROCEDURE [
a: LONG POINTER TO PupAddress, s: LONG STRING] =
BEGIN IF ~ParsePupAddressConstant[a, s] THEN PupNameLookup[a, s]; END;
-- Lookup Text string as Name Via our own NameServer
PupNameLookup: PUBLIC PROCEDURE [
a: LONG POINTER TO PupAddress, s: LONG STRING] =
BEGIN
TakeTheFirst: PROCEDURE [him: PupAddress] RETURNS [BOOLEAN] =
BEGIN
a.net ← him.net;
a.host ← him.host;
IF him.socket # [0, 0] THEN a.socket ← him.socket;
RETURN[TRUE];
END;
IF s.length = 2 AND s[0] = 'M AND s[1] = 'E THEN
BEGIN -- special case hack
me: PupAddress ← UniqueLocalPupAddress[NIL];
a.net ← me.net;
a.host ← me.host;
RETURN;
END;
IF EnumeratePupAddresses[s, TakeTheFirst] THEN RETURN;
ERROR PupNameTrouble["No Route to that Host"L, noRoute];
END;
EnumeratePupAddresses: PUBLIC PROCEDURE [
s: LONG STRING, filter: PROCEDURE [PupAddress] RETURNS [BOOLEAN]]
RETURNS [hit: BOOLEAN] =
BEGIN
pool: Buffer.AccessHandle ← Buffer.MakePool[send: 1, receive: 10];
soc: PupSocket ← PupSocketMake[
PupTypes.fillInSocketID, GetMyMiscServicesSoc[], SecondsToTocks[2]];
b: PupBuffer ← NIL;
BEGIN
ENABLE
UNWIND => -- this is the error exit
BEGIN
IF b # NIL THEN Buffer.ReturnBuffer[b];
PupSocketDestroy[soc];
Buffer.DestroyPool[pool];
END;
FOR try: CARDINAL IN [0..20) DO
b ← Buffer.GetBuffer[pup, pool, send];
b.pup.pupType ← nameLookup;
b.pup.pupID ← [try, try];
MoveStringBodyToPupBuffer[b, s];
IF try > 10 THEN
BEGIN
b.pup.source ← soc.getLocalAddress[];
b.pup.dest.socket ← PupTypes.miscSrvSoc;
PupRouterBroadcastThis[b];
END
ELSE soc.put[b];
b ← NIL; -- In case we get Aborted and then UNWIND
b ← soc.get[]; -- 2 sec wait
IF b # NIL THEN
SELECT b.pup.pupType FROM
nameIs =>
BEGIN
maxAnswers: CARDINAL = 35;
maxHops: CARDINAL = 999;
trialAddress: LONG POINTER TO ARRAY OF PupAddress ←
LOOPHOLE[@b.pup.pupWords];
distance: ARRAY [0..maxAnswers) OF CARDINAL ← ALL[maxHops];
howMany: CARDINAL;
howMany ← MIN[
maxAnswers, GetPupContentsBytes[b]/(2*SIZE[PupAddress])];
FOR i: CARDINAL IN [0..howMany) DO
rte: PupRouterDefs.RoutingTableEntry;
rte ← PupRouterDefs.GetRoutingTableEntry[trialAddress[i].net];
IF rte # NIL AND rte.context # NIL THEN distance[i] ← rte.hop;
ENDLOOP;
hit ← FALSE;
FOR j: CARDINAL IN [0..maxHops) UNTIL hit DO
FOR i: CARDINAL IN [0..howMany) UNTIL hit DO
IF distance[i] # j THEN LOOP;
hit ← filter[trialAddress[i]];
ENDLOOP;
ENDLOOP;
Buffer.ReturnBuffer[b];
PupSocketDestroy[soc];
Buffer.DestroyPool[pool];
RETURN;
END;
nameError => SaveFrameSpace[b];
ENDCASE => BEGIN Buffer.ReturnBuffer[b]; b ← NIL; END;
ENDLOOP;
ERROR PupNameTrouble["No name lookup server responded"L, noResponse];
END; -- of ENABLE
END;
SaveFrameSpace: PROCEDURE [b: PupBuffer] =
BEGIN
error: STRING = [50];
AppendPseudoString[error, DESCRIPTOR[@b.pup.pupBytes, GetPupContentsBytes[b]]];
ERROR PupNameTrouble[error, errorFromServer];
END;
-- Parse a string of the form net#host#socket
-- Setup net and host appropiately, Don't change socket if not specified
-- RETURNs TRUE unless can't parse it.
ParsePupAddressConstant: PUBLIC PROCEDURE [
a: LONG POINTER TO PupAddress, s: LONG STRING] RETURNS [BOOLEAN] =
BEGIN
n, h, s1, s2: CARDINAL ← 0;
i: CARDINAL;
c: CHARACTER;
bar: BOOLEAN ← FALSE;
IF s = NIL OR s.length = 0 THEN RETURN[FALSE];
FOR i ← 0, i + 1 UNTIL i = s.length DO
SELECT (c ← s[i]) FROM
'| => BEGIN IF bar THEN RETURN[FALSE]; bar ← TRUE; s1 ← s2; s2 ← 0; END;
'# =>
BEGIN
IF bar THEN RETURN[FALSE];
IF n # 0 OR s1 # 0 THEN RETURN[FALSE];
n ← h;
h ← s2;
s1 ← s2 ← 0;
END;
IN ['0..'9] =>
BEGIN
IF ~bar THEN s1 ← s1*8 + s2/17777B -- 32 bit number
ELSE IF s2 > 17777B THEN RETURN[FALSE];
s2 ← s2*8 + CARDINAL[c - '0];
END;
ENDCASE => RETURN[FALSE];
ENDLOOP;
IF n ~IN [0..377B] THEN RETURN[FALSE];
IF h ~IN [0..377B] THEN RETURN[FALSE];
a.net ← [n];
a.host ← [h];
IF s1 # 0 OR s2 # 0 THEN a.socket ← [s1, s2];
RETURN[TRUE];
END;
-- Inverse of PupNameLookup
PupAddressLookup: PUBLIC PROCEDURE [s: LONG STRING, a: PupAddress] =
BEGIN
pool: Buffer.AccessHandle ← Buffer.MakePool[send: 1, receive: 10];
soc: PupSocket ← PupSocketMake[
PupTypes.fillInSocketID, GetMyMiscServicesSoc[], SecondsToTocks[2]];
b: PupBuffer ← NIL;
BEGIN
ENABLE
UNWIND => -- this is the error exit
BEGIN
IF b # NIL THEN Buffer.ReturnBuffer[b];
PupSocketDestroy[soc];
Buffer.DestroyPool[pool];
END;
FOR try: CARDINAL IN [0..20) DO
b ← Buffer.GetBuffer[pup, pool, send];
b.pup.pupType ← addressLookup;
b.pup.pupID ← [try, try];
b.pup.address ← a;
SetPupContentsWords[b, SIZE[PupAddress]];
IF try > 10 THEN
BEGIN
b.pup.source ← soc.getLocalAddress[];
b.pup.dest.socket ← PupTypes.miscSrvSoc;
PupRouterBroadcastThis[b];
END
ELSE soc.put[b];
b ← NIL; -- In case we get Aborted and then UNWIND
b ← soc.get[]; -- 2 sec wait
IF b # NIL THEN
SELECT b.pup.pupType FROM
addressIs =>
BEGIN
AppendPseudoString[
s, DESCRIPTOR[@b.pup.pupBytes, GetPupContentsBytes[b]]];
Buffer.ReturnBuffer[b];
PupSocketDestroy[soc];
Buffer.DestroyPool[pool];
RETURN;
END;
nameError => SaveFrameSpace[b];
ENDCASE => BEGIN Buffer.ReturnBuffer[b]; b ← NIL; END;
ENDLOOP;
ERROR PupNameTrouble["No name lookup server responded"L, noResponse];
END; -- of ENABLE
END;
AppendMyName: PUBLIC PROCEDURE [name: LONG STRING] =
BEGIN AppendHostName[name, UniqueLocalPupAddress[NIL]]; END;
AppendHostName: PUBLIC PROCEDURE [s: LONG STRING, who: PupAddress] =
BEGIN
who.socket ← [0, 0];
PupAddressLookup[
s, who ! PupNameTrouble => BEGIN AppendPupAddress[s, who]; CONTINUE; END];
END;
AppendOctal: PROCEDURE [s: LONG STRING, n: CARDINAL] =
BEGIN
IF n > 7 THEN AppendOctal[s, n/8];
String.AppendChar[s, '0 + (n MOD 8)];
END;
-- move the body of a mesa STRING into the body of a packet and set its length
MoveStringBodyToPupBuffer: PUBLIC PROCEDURE [b: PupBuffer, s: LONG STRING] =
BEGIN
dataBytesPerPup: CARDINAL ← 2*DataWordsPerPupBuffer[];
IF s = NIL THEN Driver.Glitch[StringIsNIL];
IF s.length > dataBytesPerPup THEN Driver.Glitch[StringTooLong];
FOR i: CARDINAL IN [0..s.length) DO b.pup.pupChars[i] ← s[i]; ENDLOOP;
SetPupContentsBytes[b, s.length];
END;
-- append the body of a mesa STRING into the body of a packet and set its length
AppendStringBodyToPupBuffer: PUBLIC PROCEDURE [b: PupBuffer, s: LONG STRING] =
BEGIN
length: CARDINAL;
dataBytesPerPup: CARDINAL ← 2*DataWordsPerPupBuffer[];
IF s = NIL THEN Driver.Glitch[StringIsNIL];
length ← GetPupContentsBytes[b];
IF (s.length + length) > dataBytesPerPup THEN
Driver.Glitch[StringTooLong];
FOR i: CARDINAL IN [0..s.length) DO b.pup.pupChars[length + i] ← s[i]; ENDLOOP;
SetPupContentsBytes[b, (s.length + length)];
END;
-- APPEND a pseudo string to a LONG STRING
AppendPseudoString: PROCEDURE [
e: LONG STRING, p: LONG DESCRIPTOR FOR PACKED ARRAY OF CHARACTER] =
BEGIN
FOR i: CARDINAL IN [0..MIN[e.maxlength - e.length, LENGTH[p]]) DO
String.AppendChar[e, p[i]]; ENDLOOP;
END;
GetMyMiscServicesSoc: PROCEDURE RETURNS [me: PupAddress] =
BEGIN me ← UniqueLocalPupAddress[NIL]; me.socket ← PupTypes.miscSrvSoc; END;
AppendPupAddress: PUBLIC PROCEDURE [s: LONG STRING, a: PupAddress] =
BEGIN
Flip: PROCEDURE [PupTypes.PupSocketID] RETURNS [LONG INTEGER] = MACHINE CODE
BEGIN Mopcodes.zEXCH END;
AppendOctal[s, a.net];
String.AppendChar[s, '#];
AppendOctal[s, a.host];
String.AppendChar[s, '#];
String.AppendLongNumber[s, Flip[a.socket], 8];
END;
AppendErrorPup: PUBLIC PROCEDURE [s: LONG STRING, b: PupDefs.PupBuffer] =
BEGIN
IF b.pup.pupType = error THEN
BEGIN
String.AppendString[s, "[Error Pup, code="L];
String.AppendOctal[s, b.pup.errorCode];
String.AppendString[s, ", from: "L];
AppendPupAddress[s, b.pup.source];
String.AppendString[s, "] "L];
FOR i: CARDINAL IN [0..PupDefs.GetPupContentsBytes[b] - 2*(10 + 1 + 1)) DO
String.AppendChar[s, b.pup.errorText[i]]; ENDLOOP;
END
ELSE
BEGIN
String.AppendString[s, "[Funny PupType = "L];
String.AppendOctal[s, b.pup.pupType];
String.AppendString[s, ", from: "L];
AppendPupAddress[s, b.pup.source];
String.AppendString[s, "]"L];
END;
END;
END.