Protocol-A.texi 280 KB
Newer Older
David Byers's avatar
David Byers committed
1
\input texinfo                         @c -*-texinfo-*-
David Byers's avatar
David Byers committed
2
3
4
@c
@c FIXME: Explain how the garb works with nice and keep-commented
@c
5
@c $Id: Protocol-A.texi,v 1.96 1999/11/20 20:06:30 ceder Exp $
David Byers's avatar
David Byers committed
6
7
8
9
10
11
12
@c %**start of header
@setfilename protocol-a.info
@settitle LysKOM Protocol A
@setchapternewpage odd
@c %**end of header
@iftex
@parindent 0pt
13
@font@tensltt=cmsltt10
14
15
16
17
18
@begin tex
\global\def\rett#1{{\let\t\sltt\tt #1}}
\global\def\sltt#1{{\fam\ttfam\tensltt\let\t\rett #1}}
\global\let\t\sltt
@end tex
David Byers's avatar
David Byers committed
19
20
21
@end iftex

@ifinfo
Per Cederqvist's avatar
Per Cederqvist committed
22
23
This is revision 10.2 of the LysKOM Protocol A specification.  It
specifies version 10 of the protocol.
David Byers's avatar
David Byers committed
24

David Byers's avatar
David Byers committed
25
Copyright @copyright{} 1995-1999 Lysator ACS.
David Byers's avatar
David Byers committed
26
27
28
29
30
31

Permission is granted to make and distribute verbatim copies of this
specification provided the copyright notice and this permission notice
are preserved on all copies.
@end ifinfo

32
33
34
35
36
@dircategory LysKOM
@direntry
* Protocol A: (protocol-a).             The LysKOM Protocol A specification.
@end direntry

David Byers's avatar
David Byers committed
37
38
39
40
@titlepage
@sp 10
@title{LysKOM Protocol A}
@sp 2
41
@subtitle{Protocol version 10}
David Byers's avatar
David Byers committed
42
43
44
45
46
@sp 2
@author by the LysKOM Developers

@page
@vskip 0pt plus 1filll
David Byers's avatar
David Byers committed
47
Copyright @copyright{} 1995-1999 Lysator ACS
David Byers's avatar
David Byers committed
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63

Permission is granted to make and distribute verbatim copies of this document
provided the copyright notice and this permission notice are preserved on all
copies.

Modified versions of this document may be redistributed with the added
condition that all modifications not cleared with the LysKOM development group
are clearly marked and that the entire modified work be redistributed under the
same conditions as the original.

Permission is granted to copy and distribute translations of this manual into
another language under the same conditions as for modified versions.

@end titlepage

@ifinfo
64
@node Top
65
@top LysKOM Protocol A
66
67

This document specifies version 10 of LysKOM Protocol A.
Per Cederqvist's avatar
Per Cederqvist committed
68
This is revision 10.2 of the specification.
David Byers's avatar
David Byers committed
69
70

@menu
71
72
73
74
75
76
77
78
79
80
81
82
* Overview::                    
* Introduction::                
* Data Types::                  
* Protocol Requests::           
* Asynchronous Messages::       
* Error Codes::                 
* LysKOM Content Types::        
* The User Area::               
* Writing Clients::             
* Importing and Exporting E-Mail::  
* Type Index::                  
* Request Index::               
David Byers's avatar
David Byers committed
83
84
85
@end menu
@end ifinfo

86
@node Overview
David Byers's avatar
David Byers committed
87
88
89
@chapter Overview

LysKOM is a conferencing system@footnote{Or in modern terms, enabling
90
91
92
93
94
95
technology for Computer-Supported Cooperative Work (CSCW).}. Similar
systems were QZ-KOM and PortaCOM@footnote{Also known as ``PottaKOM'' and
``BortaKOM.''}. The LysKOM system is copyrighted by Lysator Academic
Computing Society and distributed under conditions of the GNU Public
License. LysKOM and its documentation is provided ``as is'' without
warranty of any kind.
David Byers's avatar
David Byers committed
96

97
This document specifies version 10 of protocol A used between a LysKOM
98
99
client and a LysKOM server. Anything described here as ``unspecified''
is liable to change in future protocol versions.
David Byers's avatar
David Byers committed
100
101

This specification is the work of several people. The main contributors have
102
been
David Byers's avatar
David Byers committed
103
104
Per Cederqvist @email{ceder@@lysator.liu.se}, 
David Byers @email{byers@@lysator.liu.se},
David Byers's avatar
David Byers committed
105
106
107
108
109
110
@ifinfo
Pär
@end ifinfo
@iftex
P@"ar
@end iftex
David Byers's avatar
David Byers committed
111
112
113
114
Emanuelsson @email{pell@@lysator.liu.se},
Thomas Bellman @email{bellman@@lysator.liu.se}, 
Lars Aronsson @email{aronsson@@lysator.liu.se},
Linus Tolke @email{linus@@lysator.liu.se} and
David Byers's avatar
David Byers committed
115
116
117
118
119
120
@ifinfo
Kent Engström
@end ifinfo
@iftex
Kent Eng@-str@"om@penalty-10000
@end iftex
David Byers's avatar
David Byers committed
121
@email{kent@@lysator.liu.se}.
David Byers's avatar
David Byers committed
122

David Byers's avatar
David Byers committed
123
124
The LysKOM developers can be reached by email to
@email{lyskom@@lysator.liu.se}.
David Byers's avatar
David Byers committed
125

126
127
128
129
@menu
* Document Revision History::   
* Protocol Version History::    
* Notation::                    
David Byers's avatar
David Byers committed
130
131
@end menu

132
@node Document Revision History
David Byers's avatar
David Byers committed
133
134
135
@section Document Revision History

@table @asis
136

Per Cederqvist's avatar
Per Cederqvist committed
137
138
139
140
@item 10.2: 1999-07-23
Some typos and other minor errors were fixed.  Distributed with lyskomd
2.0.2.

141
@item 10.1: 1999-07-12
David Byers's avatar
Server:    
David Byers committed
142
Call @code{sub-comment} was incorrectly marked obsolete. This has been
143
144
145
146
147
corrected. Regexps are case sensitive.  The Info-Type enumeration was
introduced in the description of the protocol.  (Previous versions of
the protocol had broken definitions of add-recipient,
async-new-recipient and async-sub-recipient.)  Distributed with lyskomd
2.0.1.
David Byers's avatar
Server:    
David Byers committed
148

149
@item 10.0: 1999-06-27
150
151
The specification was translated to English and converted to Texinfo by
David Byers.  Protocol version 10.  Distributed with lyskomd 2.0.0.
152
153
154
Note: this revision incorrectly marked the @code{sub-comment} call as
obsolete, and stated that regexp lookup was case insensitive.  Both
statements were wrong, and has since been fixed.
155
156

@item 9.0: 1996-08-04
157
Protocol version 9.  Distributed with lyskomd 1.9.0.
158

David Byers's avatar
David Byers committed
159
@item 8.0: 1995-11-10
160
Protocol version 8.  Distributed with lyskomd 1.8.0.
David Byers's avatar
David Byers committed
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184

@item 7.1: 1995-01-08.
Protocol and document revision history were added by Per Cederqvist. Outline
mode was used to make the document more manageable. This version was
distributed with lyskomd 1.7.1.

@item 7.0: 1994-12-31.
The first specification with a version number. All calls that had been added
since 1991-06-25 were documented. Pell and Per Cederqvist did the deed. This
version was distributed with lyskomd 1.7.0.

@item 1993-05-19.
Linus Tolke wrote comments for some calls that were without comments.

@item 1992-07-06.
Linus Tolke converted the document to ISO 8859-1.

@item 1991-08-12.
Per Cederqvist started using version control for documentation.

@item 1991-06-25.
Lars Aronsson documented the protocol that was in use at the time.
@end table

185
@node Protocol Version History
186
187
188
@section Protocol Version History

@subsection Protocol version 10 (first implemented in lyskomd 2.0.0)
David Byers's avatar
David Byers committed
189

190
@table @asis
191
192
193
194
195
196

@item Error codes

The error codes are now documented.  Several error codes were changed to
more sane values while documenting the new behaviour.

197
@item New Server Calls
198
199
200

These new calls have status Recommended.

201
202
203
204
205
206
207
208
209
210
211
212
213
@itemize @bullet
@item 85=get-collate-table
@item 86=create-text
@item 87=create-anonymous-text
@item 88=create-conf
@item 89=create-person
@item 90=get-text-stat
@item 91=get-conf-stat
@item 92=modify-text-info
@item 93=modify-conf-info
@item 94=get-info
@item 95=modify-system-info
@item 96=query-predefined-aux-items
214
215
216
217
@item 98=query-read-texts
@item 99=get-membership
@item 100=add-member
@item 101=get-members
218
219
220
@item 102=set-membership-type
@item 103=local-to-global
@item 104=map-created-texts
221
222
223
224
225
226
227
@item 106=set-pers-flags
@end itemize

These new calls have status Experimental.

@itemize @bullet
@item 97=set-expire
David Byers's avatar
David Byers committed
228
@item 105=set-keep-commented
229
230
@end itemize

231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
@item Name changes

@multitable {59=create-anonymous-text} {59=create-anonymous-text-old}
@item Old name                 @tab New name
@item 5=create-person          @tab 5=create-person-old
@item 9=query-read-texts       @tab 9=query-read-texts-old
@item 10=create-conf           @tab 10=create-conf-old
@item 13=get-conf-stat-old     @tab 13=get-conf-stat-older
@item 14=add-member            @tab 14=add-member-old
@item 26=get-text-stat         @tab 26=get-text-stat-old
@item 28=create-text           @tab 28=create-text-old
@item 36=get-info              @tab 36=get-info-old
@item 46=get-membership        @tab 46=get-membership-old
@item 48=get-members           @tab 48=get-members-old
@item 50=get-conf-stat         @tab 50=get-conf-stat-old
@item 59=create-anonymous-text @tab 59=create-anonymous-text-old
@end multitable

@item Status change

The following calls have change status from Experimental to Recommended.

253
@itemize @bullet
254
255
256
257
258
@item 58=get-last-text
@item 77=set-last-read
@item 78=get-uconf-stat
@end itemize

259
The following calls have changed status from Recommended or
260
261
262
263
264
265
266
267
268
Experimental to Obsolete.

@itemize @bullet
@item 5=create-person-old
@item 9=query-read-texts-old
@item 10=create-conf-old
@item 14=add-member-old
@item 26=get-text-stat-old
@item 28=create-text-old
269
@item 36=get-info-old
270
@item 46=get-membership-old
271
@item 47=get-created-texts
272
@item 48=get-members-old
273
274
@item 50=get-conf-stat-old
@item 59=create-anonymous-text-old
275
276
@end itemize

277
@item New and Modified Structures
278
@itemize @bullet
279
@item Aux-Item
280
@item Aux-Item-Input
281
282
@item Conference
@item Info
283
284
285
@item Member
@item Membership
@item Membership-Type
286
287
@item Misc-Info
@item Text-Stat
288
289
@end itemize

290
291
292
293
294
295
@item Renamed Asynchronous Messages
A @samp{async-} prefix has been added to the name of all asynchronous
messages.  In addition, 0=new-text has been renamed to
0=async-new-text-old, and it is now considered obsolete.  Clients should
use 80=accept-async to listen to 15=async-new-text instead.

296
297
@item New Asynchronous Messages
@itemize @bullet
298
299
300
301
302
@item 14=async-deleted-text
@item 15=async-new-text
@item 16=async-new-recipient
@item 17=async-sub-recipient
@item 18=async-new-membership
303
@end itemize
304
305
306

@item Notes
@itemize @bullet
307
@item Since protocol version 9 setting a priority of zero for a
308
309
310
conference was supposed to indicate passive membership in a conference. 
It was largely up to the client to implement this. True passive
memberships have been introduced in this protocol version through the
311
Membership-type extension to the Membership type. In order to maintain
312
313
314
315
316
compatibility with clients that interpret priority 0 as passive
membership, the old calls @pxref{add-member-old} and
@pxref{get-membership-old} perform magic, translating between priorities 
and membership types. The magic is documented with each call.
@end itemize
317
318
@end table

319

320
@subsection Protocol version 9 (first implemented in lyskomd 1.9.0)
321
322

@table @asis
323
324
325
326
327
328
@item New functionality
@itemize @bullet
@item The server shall now reply with error @code{not-implemented} when
a client attempts to use an unimplemented call.  This feature requires
that the client uses newline as call terminator.
@end itemize
Per Cederqvist's avatar
Per Cederqvist committed
329
@item Added Commands
330
@itemize @bullet
331
332
333
334
335
336
@item 79=set-info: Can change server information.
@item 80=accept-async: Can select asynchronous messages to receive.
@item 81=query-async: Can query which messages are being send.
@item 82=user-active
@item 83=who-is-on-dynamic
@item 84=get-static-session-info
337
@end itemize
338
339
340
341
342
343
344
@item Changed names
@itemize @bullet
@item @code{change-conference} was previously called @code{pepsi}.  The
name was changed, but not the functionality.
@end itemize
@item Status change
@itemize @bullet
David Byers's avatar
David Byers committed
345
346
@item 63=@code{who-is-on-ident} is now considered obsolete.
@item 64=@code{get-session-info-ident} is now considered obsolete.
347
@end itemize
348
349
@end table

350
@subsection Protocol version 8 (first implemented in lyskomd 1.8.0)
David Byers's avatar
David Byers committed
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385

@table @asis 
@item Added Functionality
@itemize @bullet
@item
30=add-recipient: Can change recpt to cc_recpt and vice versa.
@item
21=set-conf-type: Accepts Conf-Type and Extended-Conf-Type.
@item
10=create-conf: Accepts Conf-Type and Extended-Conf-Type.
@end itemize

@item New Commands
@itemize @bullet
@item
77=set-last-read
@item
78=get-uconf-stat
@end itemize
@end table

@subsection Protocol version 7 (first implemented in lyskomd 1.7.0)

@table @asis
@item Added Functionality
@itemize @bullet
@item
53=send-message: Recipient can be a conference or a person.
@end itemize

@item New Commands
@itemize @bullet
@item
74=re-z-lookup
@item
386
75=get-version-info
David Byers's avatar
David Byers committed
387
@item
388
76=lookup-z-name
David Byers's avatar
David Byers committed
389
390
391
392
393
@end itemize

@item Other
@itemize @bullet
@item
Per Cederqvist's avatar
Per Cederqvist committed
394
The asynchronous message 1=i-am-off has been removed
David Byers's avatar
David Byers committed
395
396
397
398
399
400
401
402
403
@end itemize
@end table

@subsection Protocol Version 6 (first implemented in lyskomd 1.4.0)

@table @asis
@item New Calls
@itemize @bullet
@item
404
67=lookup-person
David Byers's avatar
David Byers committed
405
@item
406
68=lookup-conf
David Byers's avatar
David Byers committed
407
@item
408
69=set-client-version
David Byers's avatar
David Byers committed
409
@item
410
70=get-client-name
David Byers's avatar
David Byers committed
411
@item
412
71=get-client-version
David Byers's avatar
David Byers committed
413
@item
414
72=mark-text
David Byers's avatar
David Byers committed
415
@item
416
73=unmark-text
David Byers's avatar
David Byers committed
417
418
419
420
421
422
423
424
425
426
@end itemize
@end table


@subsection Protocol Version 5 (first implemented in lyskomd 1.3.0)

@table @asis
@item New Calls
@itemize @bullet
@item
427
65=re-lookup-person
David Byers's avatar
David Byers committed
428
@item
429
66=re-lookup-conf
David Byers's avatar
David Byers committed
430
431
432
433
434
435
436
437
438
439
440
@end itemize
@end table

@subsection Protocol Version 4 (first implemented in lyskomd 1.1.1)

@table @asis
@item New Calls
@itemize @bullet
@item
62=login
@item
441
63=who-is-on-ident
David Byers's avatar
David Byers committed
442
@item
443
64=get-session-info-ident
David Byers's avatar
David Byers committed
444
445
446
447
448
449
450
451
452
@end itemize
@end table

@subsection Protocol Version 3 (first implemented in lyskomd 1.1.0)

@table @asis
@item New Calls
@itemize @bullet
@item
453
61=find-previous-text-no
David Byers's avatar
David Byers committed
454
@item
455
60=find-next-text-no
David Byers's avatar
David Byers committed
456
@item
457
59=create-anonymous-text
David Byers's avatar
David Byers committed
458
@item
459
58=get-last-text
David Byers's avatar
David Byers committed
460
461
462
463
464
465
466
467
468
@end itemize
@end table

@subsection Protocol Version 2 (first implemented in lyskomd 0.30.0)

@table @asis
@item New Calls
@itemize @bullet
@item
469
57=set-user-area
David Byers's avatar
David Byers committed
470
471
472
473
474
475
476
477
478
479
480
@end itemize
@end table

@subsection Protocol Version 1 (first implemented in lyskomd 0.29.2)

@table @asis
@item New Calls
All calls from 0--56.
@end table


481
@node Notation
David Byers's avatar
David Byers committed
482
483
@section Notation

484
This specification uses a BNF-like grammar to describe the protocol and
485
its data elements.
David Byers's avatar
David Byers committed
486

487
Data fields have been given names that start with a lower-case letter.
488
489
490
491
492
493
494
495
496
497
498

Fundamental data types have names in all-caps (such as @code{INT32} and
@code{ARRAY}).

Derived data types have names that start with an upper-case letter. (If
the type contains more than one word, all words start with an upper-case
letter, like this: @code{Text-Stat}.)  The operator @code{::=} defines
the name to its left.

Comments start with @code{!} (exclamation mark) and alternatives are
separated by a @code{|} (vertical bar.) A @code{;} (semicolon)
499
500
501
terminates statements in the grammar. In some specifications there are
literal strings. There is to be no whitespace before or after literal
strings unless there is whitespace in the literal itself.
David Byers's avatar
David Byers committed
502
503


504
@node Introduction
David Byers's avatar
David Byers committed
505
506
507
508
509
510
@chapter Introduction

This chapter introduces the concepts used in LysKOM, such as articles,
conferences and sessions. 

@menu
511
512
513
514
515
516
517
* Articles::                    
* Conferences::                 
* The Misc-Info List::          
* The Aux-Item List::           
* Security::                    
* Membership and Reading::      
* Client-Server Dialog::        
David Byers's avatar
David Byers committed
518
519
520
@end menu


521
@node Articles
David Byers's avatar
David Byers committed
522
523
524
525
@section Articles

An article is represented as a value of the type @code{Text-Stat} and a
string containing the article contents. An article will usually have one
526
527
528
529
or more recipients and may be a comment or footnote to other articles.
Each article is kept in the database until it is older than the
@code{nice} value of each of its recipients and it is not marked by any
user.
David Byers's avatar
David Byers committed
530

531
532
533
534
535
Currently there is a structure called a @code{Misc-Info-List} associated
with the @code{Text-Stat}. This list contains information about
recipients, senders, comments and footnotes. In the future the
information contained in the @code{Misc-Info-List} will be integrated
into the @code{Text-Stat}.
David Byers's avatar
David Byers committed
536
537
538

Every article has at least one number, the global article number. Global
numbers are assigned in ascending order to new articles, and are never
539
reused. If an article has recipients it will also have a local number
Per Cederqvist's avatar
Per Cederqvist committed
540
for each recipient. Local numbers are used in some data structures to
541
provide more compact storage and to provide an ordering of articles for
542
543
544
a particular recipient. Local numbers are assigned in ascending order
and are never reused for a particular recipient, though different
recipients will have articles with the same local numbers.
David Byers's avatar
David Byers committed
545

546
Occasionally it is necessary to map between local and global numbers.
547
The server call @code{local-to-global} does this.
David Byers's avatar
David Byers committed
548
549
550



551
@node Conferences
David Byers's avatar
David Byers committed
552
553
@section Conferences

554
555
556
557
Conferences hold articles. They are represented in the protocol as a
data type called @code{Conference}. Each conference has a
@emph{creator}, the person who created the conference, and a
@emph{supervisor}, a conference whose members can modify the conference.
David Byers's avatar
David Byers committed
558
If the supervisor is a person, the members of that person's mailbox
559
560
561
562
563
are supervisors, which in most cases is only that person. We have also
introduced a type called @code{UConference} (pronounced micro-conf-stat)
which holds a subset of the information contained in the full
@code{Conference} type. Use the @code{UConference} type whenever
possible since it places a much smaller load on the LysKOM server.
David Byers's avatar
David Byers committed
564
565

Each conference has a type, which is essentially a collection of boolean
Per Cederqvist's avatar
Per Cederqvist committed
566
flags. Currently the flags @code{rd-prot}, @code{letterbox},
567
568
@code{secret}, @code{original},  @code{allow-anonymous} and 
@code{forbid-secret} are defined.
David Byers's avatar
David Byers committed
569
570
571
572
573
574
575

@table @code
@item rd-prot
The conference is protected from reading by non-members. Persons become
members by having one of the existing members or supervisors add him or
her to the conference. This restriction is enforced by the server.
@item original
576
577
578
579
Conferences of this type are intended for original articles only.
Comments are to be redirected to the super-conference instead. This
restriction is currently not enforced by the server; clients must
implement this functionality.
David Byers's avatar
David Byers committed
580
@item letterbox
581
Conferences of this type are connected to persons. Letters to a person
David Byers's avatar
David Byers committed
582
are sent to the mailbox and the name of the mailbox is synchronized
583
584
with the person name. It is currently not possible to explicitly set or
clear this flag on a conference.
David Byers's avatar
David Byers committed
585
586
@item secret
Conferences of this type are secret. The server will not divulge any
587
information about the existence of the conference to persons who are not
David Byers's avatar
David Byers committed
588
members or supervisors of the conference. If a mailbox is made secret,
David Byers's avatar
David Byers committed
589
590
that person cannot log in using the person name, but must specify a
person number instead.
591
592
593
@item allow-anonymous
Conferences of this type accept anonymous articles. Other conferences
will reject anonymous articles.
David Byers's avatar
David Byers committed
594
595
596
@item forbid-secret
Conferences of this type do not allow secret members. If a conference is 
changed to this type, preexisting secret members remain secret.
David Byers's avatar
David Byers committed
597
598
599
600
@end table



601
602
603
604
@menu
* Persons and Sessions::        
@end menu

605
@node Persons and Sessions
David Byers's avatar
David Byers committed
606
607
608
@subsection Persons and Sessions

Persons are represented in the protocol by values of the type
609
610
611
612
@code{Person}. Associated with persons are statistics, a set of personal
flags and a set of privileges (@pxref{Security}.) Persons are also
associated with a conference that has the same number as the person and
the @code{letterbox} bit set.
David Byers's avatar
David Byers committed
613
614

Connections to the server are represented as values of the type
615
616
617
618
619
620
@code{Static-Session-Info}, @code{Session-Info-Ident} or
@code{Session-Info}. Sessions have session number that are unique for
each session in the lifetime of the server execution. A single user can
have several sessions running at once. The session is not released until
the network connection is closed; a user can log in and out repeatedly
in a single session.
David Byers's avatar
David Byers committed
621
622


623
@node The Misc-Info List
David Byers's avatar
David Byers committed
624
625
@section The Misc-Info List

626
627
The @code{Misc-Info} list contains tagged data. The fields are sent in
groups pertaining to a particular type of information: information about
628
629
recipient; carbon copy recipient; blank carbon copy recipient;
comment to; footnote to; comment in
630
631
632
and footnote in. The information groups may be sent in any order and
there may be any number of groups. Within each group the elements are
always sent in the order listed below.
David Byers's avatar
David Byers committed
633

634
@subsection Recipient
David Byers's avatar
David Byers committed
635
636
637

@table @code
@item recpt
638
639
Starts a recipient group. It contains the conference number of a
recipient of the article.
David Byers's avatar
David Byers committed
640
@item loc-no
641
642
643
Always present within a recipient group. It contains the local text
number of the article in the conference specified by the preceding
@code{recpt} field.
David Byers's avatar
David Byers committed
644
@item rec-time
645
646
647
If the recipient is a person, this element is added by the server when
the recipient marks the article as read. It contains the time when the
text was read.
David Byers's avatar
David Byers committed
648
@item sent-by
649
650
651
Present when the recipient was added by a person other than the author
(after the article was created.) It contains the person number of the
person who added the recipient.
David Byers's avatar
David Byers committed
652
@item sent-at
653
654
Present when the recipient was added after the article was created. It
contains the time when the recipient was added.
David Byers's avatar
David Byers committed
655
656
657
@end table


658
@subsection Carbon Copy (CC) Recipient
David Byers's avatar
David Byers committed
659

660
661
662
663
The carbon-copy recipient group is identical to the recipient group
above. The difference is how new comments to an article with a recipient
or carbon-copy recipient are treated. A comment to an article is sent to
all recipients, but not to carbon-copy recipients of the original
Per Cederqvist's avatar
Per Cederqvist committed
664
article. This difference is enforced by the clients.
David Byers's avatar
David Byers committed
665
666
667

@table @code
@item cc-recpt
668
669
Starts a carbon-copy recipient group. It contains the conference number
of a carbon-copy recipient of the article.
David Byers's avatar
David Byers committed
670
@item loc-no
671
672
673
Always present in a CC recipient group. It contains the local text
number of the article in the conference specified by the most recent
@code{cc-recpt} field.
David Byers's avatar
David Byers committed
674
@item rec-time
675
Present after the CC recipient has read the article. It contains the
676
677
time when the article was read. Since only persons can read articles
this will only be seen if the CC recipient is a person.
David Byers's avatar
David Byers committed
678
679
680
@item sent-by
Present when a CC recipient was added by a person other than the author
after the article had been created. It contains the person number of the
681
person who added the CC recipient.
David Byers's avatar
David Byers committed
682
683
684
685
686
687
@item sent-at
Present when a CC recipient was added after the article had been
created. It is the time when the CC recipient was added.
@end table


688
689
690
691
692
@subsection Blank Carbon Copy (BCC) Recipient

The blank carbon-copy recipient group is identical to the carbon-copy
recipient group above. The difference is the visibility of the
information. A carbon-copy recipient group is visible to anyone that is
693
allowed to fetch both the text status of the involved text and the
694
conference status of the involved conference.  (That is, as long as the
695
conference isn't secret everybody is allowed to see the carbon-copy
696
697
698
699
700
701
recipient group.)

A BCC recipient group is only visible to members and supervisors of the
recipient.  This is enforced by the server.

This type of group was introduced in protocol version 10.  When
702
703
704
old-style calls such as get-text-stat-old (@pxref{get-text-stat-old})
are used this will be converted to a CC recipient group by the server
for the benefit of clients that don't understand this group.
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727

@table @code
@item bcc-recpt
Starts a blank carbon-copy recipient group. It contains the conference
number of a blank carbon-copy recipient of the article.
@item loc-no
Always present in a BCC recipient group. It contains the local text
number of the article in the conference specified by the most recent
@code{bcc-recpt} field.
@item rec-time
Present after the BCC recipient has read the article. It contains the
time when the article was read. Since only persons can read articles
this will only be seen if the BCC recipient is a person.
@item sent-by
Present when a BCC recipient was added by a person other than the author
after the article had been created. It contains the person number of the
person who added the BCC recipient.
@item sent-at
Present when a BCC recipient was added after the article had been
created. It is the time when the BCC recipient was added.
@end table


728
@subsection Comment To
David Byers's avatar
David Byers committed
729
730
731
732
733
734
735
736
737
738

@table @code
@item comm-to
Always present when the article is a comment to another article.
@item sent-by
Present when the article was added as a comment by a person other than
the author, after the article had been created. It contains the person
number of the person who added the article as a comment.
@item sent-at
Present when the article was added as a comment after the article had
739
been created. It contains the time when it was added as a comment.
David Byers's avatar
David Byers committed
740
741
742
@end table


743
@subsection Footnote To
David Byers's avatar
David Byers committed
744
745

@table @code
746
@item footn-to
David Byers's avatar
David Byers committed
747
748
749
Always present when the article is a footnote to another article.
@item sent-at
Present when the article was added as a footnote after the article had
750
been created. It contains the time when it was added as a footnote.
David Byers's avatar
David Byers committed
751
752
753
@end table


754
@subsection Comment in
David Byers's avatar
David Byers committed
755
756
757
758
759
760
761
762

@table @code
@item comm-in
Present when there are comments to this article. It contains the article
number which is a comment to this article.
@end table


763
@subsection Footnote in
David Byers's avatar
David Byers committed
764
765

@table @code
766
@item footn-in
David Byers's avatar
David Byers committed
767
768
769
770
771
Present when there are footnotes to this article. It contains the
article number which is a footnote to this article.
@end table


772
@node The Aux-Item List
773
@section The Aux-Item List
774
775
776
777
778

The aux-item list is used as a generic extension mechanism in the LysKOM
server and in protocol A. 

@menu
779
780
781
782
783
* About Aux-Items::             
* Predefined Aux-Item Types::   
* Client-Specific Aux-Item Types::  
* Experimental Aux-Item Types::  
* Defining New Aux-Item Types::  
784
785
@end menu

786
@node About Aux-Items
787
@subsection About Aux-Items
788
789
790
791

Aux-items were introduced in protocol version 10 as a mechanism for
extending the conference, text and server information structures without
changing the protocol. Persons were excluded since nobody could figure
David Byers's avatar
David Byers committed
792
out a case where setting an aux-item on the mailbox wasn't as good as
793
794
795
796
797
798
799
800
801
setting it on the person (another reason was that I was fed up writing
aux-item code by the time they were working on texts and conferences.)

The exact structure of an aux item is specified elsewhere (@pxref{LysKOM
Data Types}). The important fields here are the aux-no, tag and data
fields.

The aux-no field is used to identify an item. The aux-no together with a
text or conference number uniquely identifies a particular aux item.
802
Items are numbered from one and up within each item list. Once assigned,
803
804
805
806
the aux-no for an item is never changed. New items are guaranteed to
be assigned numbers that have never been used before within a particular
list.

807
The tag field identifies the type of aux item. It is used by the server
808
809
810
811
812
813
814
815
816
817
and by clients to figure out how to interpret the data field, and by the
server to decide if the item needs special treatment.

The data field is a simple string. The meaning of the string is
determined by the tag field, but since it is a string, clients that have
no understanding of the contents can successfully parse the item anyway
(in contrast to items in the misc-info list.)



818
@node Predefined Aux-Item Types
819
@subsection Predefined Aux-Item Types
820

David Byers's avatar
David Byers committed
821
822
823
Predefined Aux-Item types are part of Protocol A, and clients should
support all of them. As with other parts of the protocol, changes to
these definitions will be made backwards-compatible, if possible.
824

David Byers's avatar
David Byers committed
825
826
827
Creation and deletion of items with a predefined type can cause
arbitrarily complex and wonderous behavior in the server. Furthermore,
the server may place constraints on the items with regard to content,
828
flags, who can create them, to what objects they can be attached and
David Byers's avatar
David Byers committed
829
830
so forth. The server may also silently enforce specific values for any
field of an item, regardless of what the client requests.
831

832
All items with tags in the range 1-9999 and 30000 and up are considered
833
834
predefined. If a client attempts to create an item with a tag in this
range, but the server has no idea what that tag means, the server will
David Byers's avatar
David Byers committed
835
return an error (illegal-aux-item.)
836

837
838
839
Some of the aux-items below (mostly the ones that begin with "mx-") are
used by mail importers. For information about supplementary aux-items
introduced by @code{komimportmail}, see @ref{komimportmail Aux-Item Types}.
840
841
842

@table @samp
@item content-type [1] (text)
843
Specifies the content type of a text. Data is a valid MIME type or one
844
845
846
847
848
849
850
851
852
853
854
of the special LysKOM types (@pxref{LysKOM Content Types}.)

This item may only be set by the author of a text. The inherit, secret
and hide-owner bits are cleared. Only one content-type item can be
created per creator.


@item fast-reply [2] (text)
Data is a string that constitutes a brief comment to the text. This
comment should be displayed immediately after the text body. 

David Byers's avatar
David Byers committed
855
856
An item of this type will never be inherited, can always be deleted, is
never anonymous and is never secret.
857
858
859


@item cross-reference [3] (text, conference)
David Byers's avatar
David Byers committed
860
Data is a cross-reference to something else. The contents consist of a
861
862
letter, a number, and optionally a space and a descriptive text. The
letter must be one
David Byers's avatar
David Byers committed
863
864
865
866
867
of T, C or P. T specifies that the cross-reference points to a text; C
that it points to a conference; and P that it points to a person. The
number is the id of the target of the cross reference. The descriptive
text is simly that, a text that describes the cross-reference. For
example, "T15 Check this out!" is a cross reference to text 15 with a
868
869
description that reads "Check this out!", and "T17" is a cross reference
without a description.
870

David Byers's avatar
David Byers committed
871
872
The inherit bit is automatically cleared and the item can always be
deleted. 
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905


@item no-comments [4] (text)
When this item is set, the author requests that nobody comments the
text. This is advisory only; it is still possible to write comments, but
clients should advise the user that this is contrary to the author's
wishes. Data should be empty.

This item may only be set by the author. The secret, hide-creator and
inherit bits are automatically cleared.


@item personal-comment [5] (text)
When this item is set, the author requests only personal comments. This
is advisory only; it is still possible to create regular comments, but
clients should advise the user that the author prefers a personal
comment. Data should be empty.

This item may only be set by the author. The secret, hide-creator and
inherit bits are automatically cleared.


@item request-confirmation [6] (text)
The author requests that everyone who reads the text confirms having
done so by creating read-confirmation items on the text. Clients should
ask users if they wish to confirm having read the text when it is
displayed. Data should be empty.

The hide-creator, secret and inherit bits are automatically cleared.


@item read-confirm [7] (text)
This item can be taken as confirmation that the item creator has read
906
907
908
the text to which the item is attached. Clients should never ever create
this item without an explicit confirmation from the user that the text
has indeed been read.
909
910

The hide-creator, secret and inherit bits are automatically cleared.
David Byers's avatar
David Byers committed
911
Once created an item of this type cannot be deleted.
912
913
914


@item redirect [8] (conference)
David Byers's avatar
David Byers committed
915

David Byers's avatar
David Byers committed
916
917
918
919
920
921
922
923
924
925
926
This item indicates that texts should not be sent to the conference,
but be directed to some other target instead. Clients should notify
users that attempt to send texts to the conference of the redirect and
offer to send the text to the target of the redirect instead. A typical
use of this item would be a user that does not read LysKOM very often
and would like to advise other users to send e-mail instead.

Data is PROTOCOL:ADDRESS where PROTOCOL is either "E-mail" or "LysKOM",
and ADDRESS is either an e-mail address or a LysKOM conference. 
Hopefully we'll be able to replace this with a forwarding mechanism
later.
927
928

This item can only be set by the conference supervisor or in the case of
David Byers's avatar
David Byers committed
929
a mailbox, the person attached to the mailbox. The hide-creator and
930
931
932
secret bits are cleared automatically. Only one redirect can be
specified.

David Byers's avatar
David Byers committed
933

934
935
936
937
938
@item x-face [9] (conference)

Data is the face of the person in compface format. Cool, innit?

This item can only be set by the conference supervisor or in the case of
David Byers's avatar
David Byers committed
939
a mailbox, the person attached to the mailbox. The hide-creator and
940
941
942
secret bits are cleared automatically. 


943
@item alternate-name [10] (text, conference)
944
945

Data is a string that the client may use as an alternate to the name of
David Byers's avatar
David Byers committed
946
947
948
a conference or the subject of a text. Note that the server does not
match against this name when performing name lookups. Clients should
only display alternate names created by the user currently logged on.
949
950
951
952
953
954
955

The inherit flag is automatically cleared.


@item pgp-signature [11] (text)

Data is a PGP signature of the text. The signature should be the
David Byers's avatar
David Byers committed
956
equivalent of what "pgp -sba" in PGP 2.6.2 generates.
957
958
959
960
961
962
963
964

The secret, hide-creator and inherit bits are automatically cleared.
Signatures cannot be deleted once they have been created.


@item pgp-public-key [12] (letterbox)

Data is the public key of the person. It is desirable that the public
David Byers's avatar
David Byers committed
965
966
967
key contains a userid of the format "LysKOM <p@var{n}@@@var{server}>+",
where @var{n} is the number of the person in the LysKOM server specified
in @var{server}. This rule is currently not enforced.
968
969
970
971

This item can only be set by the person himself. The hide-creator,
secret and inherit bits are automatically cleared.

David Byers's avatar
David Byers committed
972

973
974
@item e-mail-address [13] (conference, letterbox, server)

David Byers's avatar
David Byers committed
975
976
Data is an RFC 822-style email address. When set on a mailbox, it
should be the email address of the person. If the person has multiple
977
978
979
email addresses he may set serveral e-mail-address aux-items.

The meaning of this aux-item when set on a conference that isn't a
David Byers's avatar
David Byers committed
980
981
982
mailbox is vague. For a conference that is used as to import a mailing
list this should be the email address of the list. For other conferences 
we haven't really defined a sensible use.
983
984

When this aux-item is set on the server it shold contain the email
985
address of the administrator (or administrators.)
986

David Byers's avatar
David Byers committed
987
988
989
This aux-item can only be set by the supervisor of a conference or the
server administrator. The creator cannot be hidden.

990
991
992
993

@item faq-text [14] (conference, server)

Data is a decimal text number, which is a FAQ for the conference (or
David Byers's avatar
David Byers committed
994
995
server). Creating an item of this type automatically causes creation of
a faq-for-conf item.
David Byers's avatar
David Byers committed
996
997
998
999

This item can only be set by the supervisor or server administrator. The 
hide-creator, secret, and inherit bits are automatically cleared.

1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011

@item creating-software [15] (text)

Data is the name and version number of the client that created the
text.  This aux-item can only be set by the author of the text.  Once
set, it cannot be removed or changed.  A typical value would be
@samp{elisp-client 0.47.3}.  Setting the creating-software aux-item is
optional.

The data should be the client name, a space, and the client version used
in the @code{set-client-version} call.  The server may enforce this
restriction.
1012

1013
@item mx-author [16] (text)
1014

1015
Data is a string containing the name of the author of an imported
1016
1017
1018
1019
1020
1021
e-mail, extracted from the @code{From} header.  This aux-item may be
missing, if the mail address in the @code{From} header consists of just
the @code{addr-spec} (see the next aux-item).

Clients should display this instead of the actual author of the text
(which will be an importer ID) even if an mx-from aux-item is not present.
1022

1023
1024
Sample contents: @code{Joe Q. Public} which may come from a @code{From}
header containing @code{"Joe Q. Public" <john.q.public@@example.com>}.
1025

1026
@item mx-from [17] (text)
1027

1028
1029
Data is the proper e-mail address (called @code{addr-spec} in the mail
standards) extracted from the @code{From} header of an imported
1030
1031
1032
1033
1034
1035
e-mail. 

Clients should display this address together with the mx-author,
preferably inside angles. If mx-author is not present, this address
should be shown anyway. It can also be used by clients to construct an
address for personal (e-mail) replies to an imported message.
1036

1037
1038
1039
Sample contents: @code{john.q.public@@example.com} which may come from a
@code{From} header containing @code{john.q.public@@example.com} or
something like @code{"Joe Q. Public" <john.q.public@@example.com>}.
1040

1041
@item mx-reply-to [18] (text)
1042

1043
1044
1045
1046
Data is the proper e-mail address (called @code{addr-spec} in the mail
standards) extracted from the @code{Reply-To} header of an imported
e-mail. Clients should use this for constructing replies to imported
messages.
1047

1048
@item mx-to [19] (text)
1049

1050
1051
1052
1053
Data is a single e-mail address from an email @code{To} header.
Multiple @code{mx-to} items may be present when multiple recipients are
specified in the header. Clients should display these items along
with the normal LysKOM recipient headers.
1054

1055
1056
1057
Sample contents: @code{john.q.public@@example.com} and
@code{"Joe Q. Public" <john.q.public@@example.com>} are both valid.

1058
@item mx-cc [20] (text)
1059

1060
1061
Same as @code{mx-to}, but applies to the @code{CC} header rather than
the @code{To} header.
1062

1063
@item mx-date [21] (text)
1064

1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
Data is the date and time from the @code{Date} header of an imported
email. Its format is "YYYY-MM-DD hh:mm:ss TZ". YYYY is the year the
message was sent, MM is the month, DD is the day, hh is the hour, mm is
the minute and ss is the second. This date and time are given in the
timezone where the message was sent. TZ is the timezone the date is
valid for. It must be of the form "+hhmm" or "-hhmm", where hh is the
number of hours offset from UTC and mm is the number of minutes
offset. Symbolic timezones are not permitted. The timezone specification
is recommended but optional, since it is not always available.

Clients should display this information as the date and time a text was
written, since the imported text will have been created at a later
time. The date and time when the mesage was imported would then be
displayed elsewhere or not at all.
1079

1080
1081
@item mx-message-id [22] (text)

1082
1083
1084
Data is the @code{Message-ID} header of an imported e-mail, with
whitespace and comments removed. The Message-ID should contain the
surrounding angles.
1085
1086
1087

@item mx-in-reply-to [23] (text)

1088
1089
1090
Data is a string containing one item of the same form as the
mx-message-id item described above. This is the Message-ID of
another mail the current text is a comment to.
1091

1092
1093
1094
1095
1096
1097
1098
Hopefully, this information comes from the @code{In-Reply-To} header
of the imported e-mail, but it could also have been picked from the end
of the @code{References} header line.

If the text really comments more than one other text directly, 
it is allowed to attach more than one @code{mx-in-reply-to} items to
it.
1099
1100
1101

@item mx-misc [24] (text)

1102
1103
1104
1105
1106
Data is a string that contains all of the headers of an imported email,
including @code{Subject}, and including those that are redundantly
stored in other aux-items. The headers are concatenated with "\n". In
other words, this item contains all headers of an imported e-mail as
they appear in the message.
1107

1108
Clients are encouraged to provide a command to display this information.
1109

1110
@item mx-allow-filter [25] (conference)
1111

1112
1113
1114
This aux-item has been declared obsolete. It was intended to supply
the importer with information on how to filter incoming messages
based on regular expressions matching header lines.
1115

1116
@item mx-reject-forward [26] (conference)
1117

1118
1119
1120
This aux-item has been declared obsolete. It was intended 
to supplement mx-allow-filter by telling where rejected mails should
be sent.
1121

David Byers's avatar
David Byers committed
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
@item notify-comments [27] (letterbox)

Data is a decimal text number that the user is interested in. Clients
should monitor this text for unread comments and present these to the
user in some convenient manner. This is typically used by users that
want to read comments to some text of theirs as soon as they arrive,
rather than in the normal reading order.

This item can only be set by the owner of the letterbox. No flags are
forced or cleared.
1132

David Byers's avatar
David Byers committed
1133
1134
1135
1136
1137
1138
1139
1140
@item faq-for-conf [28] (text)

Data is a decimal number specifying the conference a certain text is a
FAQ for. The special number zero denotes that the text is a FAQ for the
entire system. Items of this kind can only be created by the LysKOM
server itself. Texts with this item are protected from garbage
collection.

1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
@item recommended-conf [29] (server)

Data is a decimal number specifying a conference that new members should
automatically be added to, optionally followed by a space and a
recommended priority, optionally followed by a space and a membership
type.  In the future, additional data may be defined; clients should
be prepared to accept and ignore a space and any trailing data that may
follow the membership type.

A few examples might clarify what the data may look like:
@table @code
@item 1
Conference number 1.
@item 2 32
Conference number 2, with priority 32.
@item 3 250 11100000
Conference number 3, with priority 250.  The membership should be
secret, passive and have the invitation bit set.
@item 4 253 01000000 garbage
Conference number 4, with priority 253.  The membership should be
passive.  The client should ignore the trailing garbage.  Note that
1162
clients are not allowed to create aux-items of this format, but the
1163
1164
1165
1166
1167
1168
should be prepared to hande them correctly.
@end table

This is a recommendation only; it is up to the client that creates a new
person to also add him to the conferences that are specified via
@code{recommended-conf}.
1169

David Byers's avatar
David Byers committed
1170
1171
@end table

1172
@node Client-Specific Aux-Item Types
1173
@subsection Client-Specific Aux-Item Types
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187

Client-specific items do not cause the server to perform any magic. All
the flags (except the delete flag) are left untouched, the data is not
validated in any way, and anyone can create any item. If you need more
server support than this, your item should be on the predefined list.

All tags in the range 10000-19999 are reserved for clients. Blocks of
100 numbers at a time can be assigned to specific clients. A client
should never create items with tags in a range assigned to another
client or in an unassigned range. Assigned ranges will never change.

Currently, the following ranges are assigned to clients:
@itemize @bullet
@item 10000-10099: The Elisp Client
1188
@item 10100-10199: komimportmail
1189
1190
1191
1192
1193
@end itemize

If you want a range of numbers, send e-mail to the LysKOM development
group.

1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
@menu
* komimportmail Aux-Item Types::
@end menu

@node komimportmail Aux-Item Types
@subsubsection komimportmail Aux-Item Types

During the design and implementation of the @code{komimportmail} mail
importer, some new aux-items were defined to solve specific problems.
These aux-items are documented here:

@table @samp

@item mx-mime-belongs-to [10100] (text)

Data is a decimal text number that this text is an attachment to.  Most
likely, the current text is also a comment (or perhaps a footnote) to
the text mentioned in the aux-item. A client can use this aux-item to
alter the display format of the text (stating that this is an
attachment, not a normal comment).


@item mx-mime-part-in [10101] (text)

Data is a decimal text number of a text that is an attachment to the
current one. In other words: this is the converse of mx-mime-belongs-to.
A client can use this aux-item to know which comments to mark as
attachments; the remaining comments are assumed to be normal.

@item mx-mime-misc [10102] (text)

Data is a string that contains all of the MIME headers for the current
text. It is set by the importer. The fields are concatenated with
"\n".

Clients are encouraged to provide a command to display this.

@item mx-envelope-sender [10103] (text)

Data is the envelope sender of an imported text. The mail server is
supposed to pass this information to the importer, for inclusion here.

@item mx-mime-file-name [10104] (text)

Data is the file name of an attachment. Most likely, the importer gets
this information from a @code{name} parameter on a @code{Content-Type}
MIME header line.

Clients are encouraged to use this file name as the default file name
when the user chooses to save the text.

@end table
1246

1247
@node Experimental Aux-Item Types
1248
@subsection Experimental Aux-Item Types
1249
1250
1251
1252
1253
1254

Experimental numbers are free for all. Use 'em any way you want. All
numbers in the range 20000-29999 are for experimental use. 



1255
@node Defining New Aux-Item Types
1256
@subsection Defining New Aux-Item Types
1257

1258
If you want a new predefined item type, just document what it does, what
1259
1260
the data format looks like and what the server is to do with the item
and send this to the LysKOM development group. We'll assign a number to
1261
your item and put the documentation in this document. 
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280

If you're not sure what you want the data to look like yet, make a note
in your documentation that the data format might change. Once you have a
data format you're happy with, update the documentation so others may
use your item.

If you need serious magic in the server (more than can be specified with
the lyskomd configuration file), you'll probably have to write the code
yourself, or hope that the development group thinks your idea is so cool
we do the job for you.

The idea is not to reject any type of item, unless there's already an
item type that does the job just as well. Adding item types should be a
much less painful process than adding new calls.





1281
@node Security
1282
@section Security
David Byers's avatar
David Byers committed
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354

Security in LysKOM is based on two components. Each person has a set of
privileges and each session has a security level. Rights in the system
require both the sufficient privileges and a sufficient security
level. The privileges currently available are wheel, admin, statistic,
create-conf, create-pers and change-name. Security levels range from 0
to 255.


@table @code
@item wheel
@emph{Normally not assigned}
@table @asis
@item Level 0
Person may always log in, even when LysKOM is crowded.
@item Level 6
Person may set Priv-Bits for all persons.
@item Level 7
Person may set password for all persons.
@item Level 8
Person acts as supervisor for everything.
@item Level 10
Person can read all articles.
@end table

@item admin
@emph{Normally not assigned}
@table @asis
@item Level 1
Shut down the server@*
Set motd_of_kom@*
Read last_login
@item Level 2
Read status of secret conferences and persons@*
Read the protected parts of person and conference statuses@*
Read the entire text status, even when there are secret recipients
@item Level 3
Change everybody's names
@item Level 4
Add/remove members@*
Add/remove recipients to articles
@item Level 5
Set super-conference@*
Remove articles
@item Level 6
Set administrator
@end table

@item statistic
@emph{Normally not assigned}
@table @asis
@item Level 2
Read the statistics portions of persons, even if protected
@end table

@item create_conf
@emph{Normally assigned}
@table @asis
@item Level 0
Create conferences
@end table

@item create_pers
@emph{Normally assigned}
@table @asis
@item Level 0
Create persons
@end table

@end table


1355
@node Membership and Reading
David Byers's avatar
David Byers committed
1356
1357
@section Membership and Reading

1358
Persons' memberships in conferences are represented in the protocol as
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
arrays of @code{Membership}-typed values. This structure contains
information about how and when the membership was created and which
texts have been read in the conference.

There are two kinds of memberships. An active membership indicates that
the person is actively participating in the conference, wants to know if 
there are unread texts and wants to receive messages send to the
conference. A passive membership is similar to no membership at all. The 
person is still a member but will not receive messages sent to the
conference and will not be notified when there are new texts. From the
user's perspective, passive membership should be like no membership at
all, but the server still remembers what the user has read in the
conference while he or she was an active member. Since protocol version
10 a bit in the membership type field of the membership structure
indicates the type of membership. Previously the server did not support
passive memberships, but there was a convention that clients should
treat the priority level zero as a passive membership.

The membership record indicates which texts have been read through the
@code{last-text-read} and @code{read-texts} fields. All texts with local 
numbers up to @code{last-text-read} have been read. In addition, all
texts with local numbers contained in the @code{read-texts} array have
been read.
David Byers's avatar
David Byers committed
1382
1383

Finding out which articles a person has read in a particular conference
1384
1385
requires a few calls. Normally, a client will retrieve a batch of
perhaps 50 articles at a time. The outline of the process is as follows:
David Byers's avatar
David Byers committed
1386
1387
1388

@enumerate
@item Fetch the membership to get the @code{last-text-read}
1389
1390
1391
1392
@item Use @pxref{local-to-global} to translate a number of local numbers 
to global numbers. 
@item Remove the global numbers corresponding to local numbers contained 
in @code{read-texts} from the result
David Byers's avatar
David Byers committed
1393
1394
1395
@item Get and translate more texts as needed.
@end enumerate

1396
The process is complicated because of the translation between local and
1397
global text numbers. If the server does not implement the
1398
1399
@pxref{local-to-global} call, it is possible to use the less
efficient but perfectly serviceable @pxref{get-map} call instead.
David Byers's avatar
David Byers committed
1400
1401


1402
@node Client-Server Dialog
David Byers's avatar
David Byers committed
1403
1404
1405
1406
1407
1408
1409
1410
@section Client-Server Dialog

The client-server dialog consists of two phases, establishing the connection
and the LysKOM session itself.

@subsection Connecting to the Server

A connection to the server is initiated by connecting to the appropriate
David Byers's avatar