RPC: Pilot compatible interface to the RPC runtime.
MesaRPC.mesa
Last Edited by: Andrew Birrell, September 13, 1983 1:33 pm
DIRECTORY
GVBasics USING[ maxRNameLength, Password ];
MesaRPC: CEDAR DEFINITIONS =
BEGIN
Short string types. Used only by Lupine clients.
maxShortStringLength: CARDINAL = 64;
ShortSTRING: TYPE = STRING;
Types for Import and Export calls.
InterfaceName: TYPE = RECORD [
type: LONG STRING ← NIL, -- e.g., "AlpineAccess.Alpine"
instance: LONG STRING ← NIL, -- e.g., "MontBlanc.Alpine"
version: VersionRange ← matchAllVersions ];
defaultInterfaceName: InterfaceName = [];
VersionRange: TYPE = MACHINE DEPENDENT RECORD[first, last: CARDINAL];
client-defined, closed interval
matchAllVersions: VersionRange = [1,0];
importer: use any version; exporter: no versioning implied
Parameter storage zones. Used only by Lupine clients.
Zones: TYPE = RECORD [
gc: ZONE ← NIL,
heap: UNCOUNTED ZONE ← NIL,
mds: MDSZone ← NIL ];
standardZones: Zones = [];
Encryption and Authentication facilities.
maxPrincipalLength: CARDINAL = MIN[maxShortStringLength, GVBasics.maxRNameLength];
Limit on length of ropes used for Principal names
Principal: TYPE = LONG STRING;
Name of authentication principal
EncryptionKey: TYPE = GVBasics.Password;
DES key
MakeKey: PROCEDURE [text: LONG STRING] RETURNS[EncryptionKey];
Conversation: TYPE = LONG POINTER TO ConversationObject;
ConversationObject: PRIVATE TYPE;
SecurityLevel: TYPE = MACHINE DEPENDENT {
none(0), -- unauthenticated, insecure; used for "unencrypted"
authOnly(1), -- authenticated, but unencrypted calls
ECB(2), -- authenticated, encrypt with ECB mode of DES
CBC(3), -- authenticated, encrypt with CBC mode of DES
CBCCheck(4) -- authenticated, encrypt with CBC mode of DES + checksum
};
ConversationLevel: TYPE = SecurityLevel[authOnly..CBCCheck];
unencrypted: Conversation = NIL;
Dummy conversation; may be passed to RPC runtime.
GetConversationID[unencrypted] = ERROR;
GetCaller[unencrypted] = NIL;
GetLevel[unencrypted] = none;
GenerateConversation: PROC RETURNS[Conversation];
Returns a handle for a previously unused Conversation. This conversation is only for local use, it must not be passed to the RPC runtime.
GetConversationID[GenerateConversation[]] = unique ID;
GetCaller[GenerateConversation[]] = NIL;
GetLevel[GenerateConversation[]] = "none";
StartConversation: PROCEDURE[
caller: Principal,
key: EncryptionKey,
callee: Principal,
level: ConversationLevel ]
RETURNS[conversation: Conversation];
Obtains authenticator for conversation, registers it with runtime, and allocates ConversationID
EndConversation: PROCEDURE [conversation: Conversation];
Terminates use of this conversation
GetCaller: PROCEDURE [conversation: Conversation] RETURNS [caller: Principal];
Returns the caller name for a current call. Result is NIL if conversation's security level is "none" (including conversation = "unencrypted").
GetLevel: PROCEDURE [conversation: Conversation] RETURNS [level: SecurityLevel];
ConversationID: TYPE[3];
UID allocated by initiator host
GetConversationID: PROC[conversation: Conversation] RETURNS[id: ConversationID];
Returns permanently unique ID of this conversation
Public signals:
AuthenticateFailure: TYPE = {
communications, -- couldn't contact authentication server(s) --
badCaller, -- invalid caller name --
badKey, -- incorrect caller password --
badCallee -- invalid callee name --
};
ExportFailure: TYPE = {
communications, -- couldn't access binding database --
badType, -- unacceptable interface type name --
badInstance, -- unacceptable interface instance name --
badVersion, -- statically silly version range --
tooMany, -- too many exports for local tables --
badCredentials -- not allowed to change the database --
};
ImportFailure: TYPE = {
communications, -- couldn't access binding database --
badType, -- unacceptable interface type name --
badInstance, -- unacceptable interface instance name --
badVersion, -- statically silly version range --
wrongVersion, -- exported version not in req'd range --
unbound, -- this instance not exported --
stubProtocol -- exporter protocol incompatible with importer --
};
CallFailure: TYPE = {
timeout, -- no acknowledgement within reasonable time --
unbound, -- server no longer exports the interface --
busy, -- server says it's too busy --
runtimeProtocol, -- user/server runtimes don't understand each other --
stubProtocol -- user/server stubs don't understand each other --
};
AuthenticateFailed: ERROR[why: AuthenticateFailure];
Raised by StartConversation
ExportFailed: ERROR[why: ExportFailure];
Raised by ExportInterface
ImportFailed: ERROR[why: ImportFailure];
Raised by ImportInterface
CallFailed: SIGNAL[why: CallFailure];
Raised by any remote call; only why=timeout is resumable
END.