[Cyan]<CedarChest6.0>VoiceUtils>NamesGV.mesa!1

NamesGV.Mesa

Last modified by Swinehart, July 19, 1985 2:41:08 pm PDT

Last Edited by: Pier, May 1, 1984 11:13:41 am PDT

This interface defines a number of groups of utility functions having to do with file names, Grapevine RNames, network host names, passwords (strings and keys), and the like.

Each group is further explained below.

DIRECTORY

GVBasics USING [ Password ],

Rope USING [ ROPE ],

RPC USING [ EncryptionKey, ShortROPE ]

;

NamesGV: CEDAR DEFINITIONS = {

ROPE: TYPE = RPC.ShortROPE;

Rname: TYPE = ROPE;

anonymousRname: Rname = NIL;

Grapevine and Name Lookup Server utilities

The .Lark registry within Grapevine is used as a replicated database to store a number of interesting things. To get more flexibility, the forwarding lists of entries are used in a nonstandard way. Each entry in the list has the form "attribute: value". The functions below allow clients to obtain or alter the attribute values of an entry. This is further explained below.

Etherphone (Lark) number 107, for RPC purposes, calls itself "173#107# (derived from its Ethernet host number.) Information about it is represented in the .Lark registry by the RName "173#107#.Lark" The GetDefaultInstance function either of these values from a supplied NetAddress.

AttributeSeq: TYPE = REF AttributeSeqRec;

AttributeSeqRec: TYPE = RECORD [

length: CARDINAL𡤀,

s: SEQUENCE maxLength: CARDINAL OF AttributeSeqValue

];

AttributeSeqValue: TYPE = RECORD [

attributeName: ATOM←$unspec,

attributeValue: ROPE←NIL

];

Authenticity: TYPE = { unknown, authentic, bogus, nonexistent, perhaps };

As a return from GVAuthenticate or GVIsAuthenticated,

unknown indicates system/communications failure;

perhaps indicates that the RName exists, but no one has demanded authentication.

nonexistent indicates that the RName doesn't exist

authentic and bogus denote the results of an authentication attempt.

GVGetAttribute: PROC [rName: ROPE, attribute: ATOM, default: ROPE] RETURNS [value: ROPE];

Default if rName or attribute not found.

GVSetAttribute: PROC [rName: ROPE, attribute: ATOM, value: ROPE];

NIL value deletes the attribute.

GVGetAttributeSeq: PROC [rName: ROPE, attribute: ATOM] RETURNS [value: AttributeSeq];

If name not found OR attribute isn't there, return NIL

GVSetAttributeSeq: PROC [rName: ROPE, attribute: ATOM, value: AttributeSeq];

If the value field in the GV forwarding list has commas in it, it can be obtained/provided as a sequence of ropes. The parsing is done at Get/Set time. The package makes arbitrary assumptions about the max. length of such a sequence. Fix it if it breaks.

AttributeSeqValue.attributeName will be NIL in this use.

GVGetAttributes: PROC[rName: ROPE] RETURNS [value: AttributeSeq];

Returns a sequence of [attributeName, attributeValue] pairs.

GVAuthenticate: PROC[rName: ROPE, key: RPC.EncryptionKey]

RETURNS [authenticity: Authenticity];

Supply the key to Grapevine, and remember the results. Once authenticated, one remains authenticated until the name is forgotten. Authenticity is retained over local cache saving and restoration. This is a security breach, but an efficient one.

GVIsAuthenticated: PROC[rName: ROPE] RETURNS [authenticity: Authenticity];

GVUpdate: PROC[rName: ROPE];

Now recent changes to this RName can be updated in the Grapevine database. Any client that calls GVSetAttribute or GVSetAttributeList must call GVUpdate when all attributes have been changed.

GVUpdateAll: PROC;

Writes all dirty RNames to GV.

GVWait: PROC;

Wait for all updates to/from the Grapevine cache to complete. Calls for cooperation on the part of the user/clients, who should not also be launching new actions that will cause Grapevine activities. Used to determine when it's OK to do a RollBack.

GVFlushCache: PROC;

Forget everything known about GV names.

GVSaveCache: PROC;

Save everything known about GV names on ./GVCacheLog.txt.

GVRestoreCache: PROC;

Get it all back. Anything known before this call is forgotten, though.