Protocol-A.texi 266 KB
 David Byers committed Jan 13, 1996 1 \input texinfo @c -*-texinfo-*-  David Byers committed Jan 07, 1999 2 3 4 @c @c FIXME: Explain how the garb works with nice and keep-commented @c  Per Cederqvist committed Feb 05, 1999 5 @c $Id: Protocol-A.texi,v 1.53 1999/02/05 22:19:28 ceder Exp$  David Byers committed Jan 13, 1996 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  David Byers committed Jul 27, 1996 13 @font@tensltt=cmsltt10  David Byers committed Jun 14, 1996 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 committed Jan 13, 1996 19 20 21 @end iftex @ifinfo  David Byers committed Jun 14, 1996 22 This is the specification of LysKOM Protocol A v. 9.0  David Byers committed Jan 13, 1996 23   David Byers committed Dec 30, 1998 24 Copyright @copyright{} 1995-1999 Lysator ACS.  David Byers committed Jan 13, 1996 25 26 27 28 29 30  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  Per Cederqvist committed Aug 02, 1998 31 32 33 34 35 @dircategory LysKOM @direntry * Protocol A: (protocol-a). The LysKOM Protocol A specification. @end direntry  David Byers committed Jan 13, 1996 36 37 38 39 @titlepage @sp 10 @title{LysKOM Protocol A} @sp 2  David Byers committed Sep 13, 1997 40 @subtitle{Protocol version 10.0}  David Byers committed Jan 13, 1996 41 42 43 44 45 @sp 2 @author by the LysKOM Developers @page @vskip 0pt plus 1filll  David Byers committed Dec 30, 1998 46 Copyright @copyright{} 1995-1999 Lysator ACS  David Byers committed Jan 13, 1996 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64  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 @node Top, Overview, (dir), (dir) @comment node-name, next, previous, up  Per Cederqvist committed Jul 07, 1998 65 This document specifies LysKOM Protocol A, version 9.0.  David Byers committed Jan 13, 1996 66   Per Cederqvist committed Aug 02, 1998 67 68 69 70 FIXME: This document is not yet published. The document you are looking at has the version numbers all wrong. This will be fixed before publication.  David Byers committed Jan 13, 1996 71 72 73 74 75 76 @menu * Overview:: * Introduction:: * Data Types:: * Protocol Requests:: * Asynchronous Messages::  David Byers committed Sep 13, 1997 77 78 79 80 * Error Codes:: * LysKOM Content Types:: * The User Area:: * Writing Clients::  David Byers committed Jan 15, 1999 81 * Importing and Exporting E-Mail::  Per Cederqvist committed Aug 22, 1998 82 83 * Type Index:: * Request Index::  David Byers committed Jan 13, 1996 84 85 86 @end menu @end ifinfo  David Byers committed Jan 15, 1999 87 @node Overview, Introduction, Top, Top  David Byers committed Jan 13, 1996 88 89 90 @chapter Overview LysKOM is a conferencing system@footnote{Or in modern terms, enabling  David Byers committed Sep 13, 1997 91 92 93 94 95 96 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 committed Jan 13, 1996 97   David Byers committed Sep 13, 1997 98 99 100 This document specifies version 10.0 of protocol A used between a LysKOM client and a LysKOM server. Anything described here as unspecified'' is liable to change in future protocol versions.  David Byers committed Jan 13, 1996 101 102  This specification is the work of several people. The main contributors have  David Byers committed Sep 13, 1997 103 104 105 been Per Cederqvist @code{}, David Byers @code{},  David Byers committed Jan 13, 1996 106 107 108 109 110 111 @ifinfo Pär @end ifinfo @iftex P@"ar @end iftex  David Byers committed Sep 13, 1997 112 113 114 Emanuelsson @code{}, Thomas Bellman @code{}, Lars Aronsson @code{},  David Byers committed Jan 13, 1996 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 Linus Tolke @code{} and @ifinfo Kent Engström @end ifinfo @iftex Kent Eng@-str@"om@penalty-10000 @end iftex @code{}. The LysKOM developers can be reached by email to @code{lyskom@@lysator.liu.se}. @menu * Document Revision History:: * Protocol Revision History:: * Protocol Design Principles:: * Notation:: @end menu  David Byers committed Jan 15, 1999 133 @node Document Revision History, Protocol Revision History,, Overview  David Byers committed Jan 13, 1996 134 135 136 @section Document Revision History @table @asis  David Byers committed Sep 13, 1997 137   David Byers committed Jun 14, 1996 138 139 140 141 @item 9.0: @i{In progress} Protocol version 9 is begin developed and this document needs to be updated.  David Byers committed Jan 13, 1996 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 @item 8.0: 1995-11-10 Protocol version 8 is being documented. This specification was translated to English and converted to Texinfo by David Byers. @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 @node Protocol Revision History, Protocol Design Principles, Document Revision History, Overview @section Protocol Revision History  David Byers committed Sep 13, 1997 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 @subsection Protocol version 10.0 @table @asis @item New Server Calls @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 @item 97=set-expire  David Byers committed Jun 14, 1998 189 190 191 192 @item 98=query-read-texts @item 99=get-membership @item 100=add-member @item 101=get-members  David Byers committed Dec 29, 1998 193 194 @item 102=local-to-global @item 103=map-created-texts  David Byers committed Jan 07, 1999 195 @item 105=set-keep-commented  David Byers committed Sep 13, 1997 196 197 198 199 200 @end itemize @item Removed Server Calls @itemize @bullet @item 5=create-person  David Byers committed Jun 14, 1998 201 @item 9=query-read-texts  David Byers committed Sep 13, 1997 202 @item 10=create-conf  David Byers committed Jun 14, 1998 203 @item 14=add-member  David Byers committed Sep 13, 1997 204 205 206 @item 26=get-text-stat @item 28=create-text @item 36=get-info-old  David Byers committed Jun 14, 1998 207 208 @item 46=get-membership-old @item 48=get-members-old  David Byers committed Sep 13, 1997 209 210 211 212 213 214 @item 50=get-conf-stat @item 59=create-anonymous-text @end itemize @item New and New Modified Structures @itemize @bullet  Per Cederqvist committed Aug 29, 1998 215 @item Aux-Item  Per Cederqvist committed Aug 29, 1998 216 @item Aux-Item-Input  David Byers committed Sep 13, 1997 217 218 @item Conference @item Info  David Byers committed Jun 14, 1998 219 220 221 @item Member @item Membership @item Membership-Type  Per Cederqvist committed Aug 29, 1998 222 223 @item Misc-Info @item Text-Stat  David Byers committed Sep 13, 1997 224 225 226 227 228 229 230 @end itemize @item New Asynchronous Messages @itemize @bullet @item async-deleted-text message @item New async-new-text message @end itemize  David Byers committed Dec 29, 1998 231 232 233 234 235 236 237 238 239 240 241 242 243  @item Notes @itemize @bullet @item Since protocol version 9 setting a priority of zero in a 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 Membership-type extension to Membership type. In order to maintain 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  David Byers committed Sep 13, 1997 244 245 @end table  David Byers committed Dec 29, 1998 246   David Byers committed Jun 14, 1996 247 248 249 @subsection Protocol version 9.0 @table @asis  Per Cederqvist committed Jul 07, 1998 250 @item Added Commands  David Byers committed Jun 14, 1996 251 @itemize @bullet  David Byers committed Sep 13, 1997 252 253 254 255 256 257 @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  David Byers committed Jun 14, 1996 258 259 260 @end itemize @end table  David Byers committed Jan 13, 1996 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 @subsection Protocol version 8.0 @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 75=get_version_info @item 76=lookup_z_name @end itemize @item Other @itemize @bullet @item  Per Cederqvist committed Jul 07, 1998 305 The asynchronous message 1=i-am-off has been removed  David Byers committed Jan 13, 1996 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 @end itemize @end table @subsection Protocol Version 6 (first implemented in lyskomd 1.4.0) @table @asis @item New Calls @itemize @bullet @item 67=lookup_person @item 68=lookup_conf @item 69=set_client_version @item 70=get_client_name @item 71=get_client_version @item 72=mark_text @item 73=unmark_text @end itemize @end table @subsection Protocol Version 5 (first implemented in lyskomd 1.3.0) @table @asis @item New Calls @itemize @bullet @item 65=re_lookup_person @item 66=re_lookup_conf @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 63=who_is_on_ident @item 64=get_session_info_ident @end itemize @end table @subsection Protocol Version 3 (first implemented in lyskomd 1.1.0) @table @asis @item New Calls @itemize @bullet @item 61=find_previous_text_no @item 60=find_next_text_no @item 59=create_anonymous_text @item 58=get_last_text @end itemize @end table @subsection Protocol Version 2 (first implemented in lyskomd 0.30.0) @table @asis @item New Calls @itemize @bullet @item 57=set_user_area @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 @node Protocol Design Principles, Notation, Protocol Revision History, Overview @section Transport Protocol Requirements LysKOM protocol A can be run on top of any reliable, bidirectional, 8-bit data stream. All current implementations use TCP/IP. At Lysator port 4894 is used on the host @code{kom.lysator.liu.se}.  Per Cederqvist committed Aug 08, 1998 399 Data in protocol A is ASCII clear text except within Hollerith strings,  David Byers committed Sep 13, 1997 400 401 402 403 where arbitrary eight-bit characters are allowed. Data arguments are separated by whitespace. The reason for this unorthodox design is that the protocol should be usable from a text-only terminal, something that is very useful during server and early client development.  David Byers committed Jan 13, 1996 404 405 406 407 408  @node Notation, , Protocol Design Principles, Overview @section Notation  David Byers committed Sep 13, 1997 409 410 411 This specification uses a BNF-like grammar to describe the protocol and its data elements. It does not use ASN.1 because we don't know ASN.1 and probably wouldn't like it very much even if we did.  David Byers committed Jan 13, 1996 412   David Byers committed Sep 13, 1997 413 Data fields have been given names that start with a lower-case letter.  Per Cederqvist committed Aug 29, 1998 414 415 416 417 418 419 420 421 422 423 424  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)  David Byers committed Sep 13, 1997 425 426 427 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 committed Jan 13, 1996 428 429   David Byers committed Jan 15, 1999 430 @node Introduction, Data Types, Overview, Top  David Byers committed Jan 13, 1996 431 432 433 434 435 436 437 438 439 440 @chapter Introduction This chapter introduces the concepts used in LysKOM, such as articles, conferences and sessions. @menu * Articles :: * Conferences :: * Persons and Sessions :: * The Misc-Info List ::  David Byers committed Sep 13, 1997 441 * The Aux-Item List ::  David Byers committed Jan 13, 1996 442 443 444 445 446 447 448 449 450 451 452 * Security :: * Membership and Reading:: * Client-Server Dialog :: @end menu @node Articles, Conferences, , Introduction @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  David Byers committed Sep 13, 1997 453 454 455 456 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 committed Jan 13, 1996 457   David Byers committed Sep 13, 1997 458 459 460 461 462 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 committed Jan 13, 1996 463 464 465  Every article has at least one number, the global article number. Global numbers are assigned in ascending order to new articles, and are never  David Byers committed Sep 13, 1997 466 reused. If an article has recipients it will also have a local number  Per Cederqvist committed Jul 07, 1998 467 for each recipient. Local numbers are used in some data structures to  Per Cederqvist committed Aug 08, 1998 468 provide more compact storage and to provide an ordering of articles for  David Byers committed Sep 13, 1997 469 470 471 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 committed Jan 13, 1996 472   David Byers committed Sep 13, 1997 473 Occasionally it is necessary to map between local and global numbers.  Per Cederqvist committed Aug 03, 1998 474 The server call @code{local-to-global} does this.  David Byers committed Jan 13, 1996 475 476 477 478 479 480  @node Conferences, Persons and Sessions, Articles, Introduction @section Conferences  David Byers committed Sep 13, 1997 481 482 483 484 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 committed Dec 26, 1998 485 If the supervisor is a person, the members of that person's mailbox  David Byers committed Sep 13, 1997 486 487 488 489 490 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 committed Jan 13, 1996 491 492  Each conference has a type, which is essentially a collection of boolean  Per Cederqvist committed Jul 07, 1998 493 flags. Currently the flags @code{rd-prot}, @code{letterbox},  David Byers committed Sep 13, 1997 494 @code{secret}, @code{original} and @code{allow-anonymous} are defined.  David Byers committed Jan 13, 1996 495 496 497 498 499 500 501  @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  David Byers committed Sep 13, 1997 502 503 504 505 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 committed Jan 13, 1996 506 @item letterbox  David Byers committed Sep 13, 1997 507 Conferences of this type are connected to persons. Letters to a person  David Byers committed Dec 26, 1998 508 are sent to the mailbox and the name of the mailbox is synchronized  David Byers committed Sep 13, 1997 509 510 with the person name. It is currently not possible to explicitly set or clear this flag on a conference.  David Byers committed Jan 13, 1996 511 512 513 @item secret Conferences of this type are secret. The server will not divulge any information of the existence of the conference to persons who are not  David Byers committed Dec 26, 1998 514 members or supervisors of the conference. If a mailbox is made secret,  David Byers committed Jan 13, 1996 515 516 that person cannot log in using the person name, but must specify a person number instead.  David Byers committed Sep 13, 1997 517 518 519 @item allow-anonymous Conferences of this type accept anonymous articles. Other conferences will reject anonymous articles.  David Byers committed Dec 26, 1998 520 521 522 @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 committed Jan 13, 1996 523 524 525 526 527 528 529 530 @end table @node Persons and Sessions, The Misc-Info List, Conferences, Introduction @subsection Persons and Sessions Persons are represented in the protocol by values of the type  David Byers committed Sep 13, 1997 531 532 533 534 @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 committed Jan 13, 1996 535 536  Connections to the server are represented as values of the type  David Byers committed Sep 13, 1997 537 538 539 540 541 542 @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 committed Jan 13, 1996 543 544   David Byers committed Sep 13, 1997 545 @node The Misc-Info List, The Aux-Item List, Persons and Sessions, Introduction  David Byers committed Jan 13, 1996 546 547 @section The Misc-Info List  David Byers committed Sep 13, 1997 548 549 The @code{Misc-Info} list contains tagged data. The fields are sent in groups pertaining to a particular type of information: information about  Per Cederqvist committed Oct 06, 1998 550 551 recipient; carbon copy recipient; blank carbon copy recipient; comment to; footnote to; comment in  David Byers committed Sep 13, 1997 552 553 554 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 committed Jan 13, 1996 555   David Byers committed Jun 14, 1996 556 @subsection Recipient  David Byers committed Jan 13, 1996 557 558 559  @table @code @item recpt  David Byers committed Sep 13, 1997 560 561 Starts a recipient group. It contains the conference number of a recipient of the article.  David Byers committed Jan 13, 1996 562 @item loc-no  David Byers committed Sep 13, 1997 563 564 565 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 committed Jan 13, 1996 566 @item rec-time  David Byers committed Sep 13, 1997 567 568 569 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 committed Jan 13, 1996 570 @item sent-by  David Byers committed Sep 13, 1997 571 572 573 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 committed Jan 13, 1996 574 @item sent-at  David Byers committed Sep 13, 1997 575 576 Present when the recipient was added after the article was created. It contains the time when the recipient was added.  David Byers committed Jan 13, 1996 577 578 579 @end table  David Byers committed Jun 14, 1996 580 @subsection Carbon Copy (CC) Recipient  David Byers committed Jan 13, 1996 581   David Byers committed Sep 13, 1997 582 583 584 585 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 committed Jul 07, 1998 586 article. This difference is enforced by the clients.  David Byers committed Jan 13, 1996 587 588 589  @table @code @item cc-recpt  David Byers committed Sep 13, 1997 590 591 Starts a carbon-copy recipient group. It contains the conference number of a carbon-copy recipient of the article.  David Byers committed Jan 13, 1996 592 @item loc-no  David Byers committed Sep 13, 1997 593 594 595 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 committed Jan 13, 1996 596 @item rec-time  David Byers committed Sep 13, 1997 597 Present after the CC recipient has read the article. It contains the  Per Cederqvist committed Oct 06, 1998 598 599 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 committed Jan 13, 1996 600 601 602 @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  Per Cederqvist committed Oct 06, 1998 603 person who added the CC recipient.  David Byers committed Jan 13, 1996 604 605 606 607 608 609 @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  Per Cederqvist committed Oct 06, 1998 610 611 612 613 614 615 616 617 618 619 620 621 622 623 @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 allowed to fetch both the text status of the involed text and the conference status of the involved conference. (That is, as long as the conference isn't secret everybody is allowed to se the carbon-copy 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  David Byers committed Jan 14, 1999 624 old-style calls such as @xref{get-text-stat-old} are used this  Per Cederqvist committed Oct 06, 1998 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 will be converted to a CC recipient group by the server for the benefit of clients that don't understand this group. @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  David Byers committed Jun 14, 1996 650 @subsection Comment To  David Byers committed Jan 13, 1996 651 652 653 654 655 656 657 658 659 660 661 662 663 664  @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 been created. It contains the time when is was added as a comment. @end table  David Byers committed Jun 14, 1996 665 @subsection Footnote To  David Byers committed Jan 13, 1996 666 667  @table @code  David Byers committed Sep 13, 1997 668 @item footn-to  David Byers committed Jan 13, 1996 669 670 671 672 673 674 675 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 been created. It contains the time when is was added as a footnote. @end table  David Byers committed Jun 14, 1996 676 @subsection Comment in  David Byers committed Jan 13, 1996 677 678 679 680 681 682 683 684  @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  David Byers committed Jun 14, 1996 685 @subsection Footnote in  David Byers committed Jan 13, 1996 686 687  @table @code  David Byers committed Sep 13, 1997 688 @item footn-in  David Byers committed Jan 13, 1996 689 690 691 692 693 Present when there are footnotes to this article. It contains the article number which is a footnote to this article. @end table  David Byers committed Sep 13, 1997 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 @node The Aux-Item List, Security, The Misc-Info List, Introduction @subsection The Aux-Item List The aux-item list is used as a generic extension mechanism in the LysKOM server and in protocol A. @menu * About Aux-Items :: * Predefined Aux-Item Types :: * Client-Specific Aux-Item Types :: * Experimental Aux-Item Types :: * Defining New Aux-Item Types :: @end menu @node About Aux-Items, Predefined Aux-Item Types, , The Aux-Item List @subsubsection About Aux-Items 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 committed Dec 26, 1998 714 out a case where setting an aux-item on the mailbox wasn't as good as  David Byers committed Sep 13, 1997 715 716 717 718 719 720 721 722 723 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.  Per Cederqvist committed Aug 08, 1998 724 Items are numbered from one and up within each item list. Once assigned,  David Byers committed Sep 13, 1997 725 726 727 728 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.  Per Cederqvist committed Aug 08, 1998 729 The tag field identifies the type of aux item. It is used by the server  David Byers committed Sep 13, 1997 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 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.) @node Predefined Aux-Item Types, Client-Specific Aux-Item Types, About Aux-Items, The Aux-Item List @subsubsection Predefined Aux-Item Types Predefined Aux-Item types are part of Protocol A, and clients are encouraged to support all of them. As with other parts of the protocol, changes to these item types will probably always be backwards-compatible. Predefined types can case serious magic to be invoked in the server. There is no limit to the strangeness that may be associated with this type of item. The server may also place limits on who may create predefined items, might verify the data field, and can force any field in the item to a specific value, no matter what the client specified.  Per Cederqvist committed Aug 08, 1998 754 All items with tags in the range 1-9999 and 30000 and up are considered  David Byers committed Sep 13, 1997 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 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 return an error (KOM_ILL_AUX.) @table @samp @item content-type [1] (text) Specifies the content type of a text. Data is a valid MIME type of one 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 committed Dec 26, 1998 775 776 An item of this type will never be inherited, can always be deleted, is never anonymous and is never secret.  David Byers committed Sep 13, 1997 777 778 779  @item cross-reference [3] (text, conference)  David Byers committed Dec 26, 1998 780 781 782 783 784 785 786 787 Data is a cross-reference to something else. The contents consist of a letter, a number, a space and a descriptive text. The letter must be one 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 description that reads "Check this out!".  David Byers committed Sep 13, 1997 788   David Byers committed Dec 26, 1998 789 790 The inherit bit is automatically cleared and the item can always be deleted.  David Byers committed Sep 13, 1997 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823  @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  Per Cederqvist committed Aug 08, 1998 824 825 826 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.  David Byers committed Sep 13, 1997 827 828  The hide-creator, secret and inherit bits are automatically cleared.  David Byers committed Dec 26, 1998 829 Once created an item of this type cannot be deleted.  David Byers committed Sep 13, 1997 830 831 832  @item redirect [8] (conference)  David Byers committed Dec 29, 1998 833   David Byers committed Dec 26, 1998 834 835 836 837 838 839 840 841 842 843 844 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.  David Byers committed Sep 13, 1997 845 846  This item can only be set by the conference supervisor or in the case of  David Byers committed Dec 26, 1998 847 a mailbox, the person attached to the mailbox. The hide-creator and  David Byers committed Sep 13, 1997 848 849 850 secret bits are cleared automatically. Only one redirect can be specified.  David Byers committed Dec 29, 1998 851   David Byers committed Sep 13, 1997 852 853 854 855 856 @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 committed Dec 26, 1998 857 a mailbox, the person attached to the mailbox. The hide-creator and  David Byers committed Sep 13, 1997 858 859 860 secret bits are cleared automatically.  Per Cederqvist committed Aug 08, 1998 861 @item alternate-name [10] (text, conference)  David Byers committed Sep 13, 1997 862 863  Data is a string that the client may use as an alternate to the name of  David Byers committed Dec 26, 1998 864 865 866 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.  David Byers committed Sep 13, 1997 867 868 869 870 871 872 873  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 committed Dec 26, 1998 874 equivalent of what "pgp -sba" in PGP 2.6.2 generates.  David Byers committed Sep 13, 1997 875 876 877 878 879 880 881 882 883 884  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 key contains a userid of the format "LysKOM +", where \1 is the number of the person in the LysKOM server specified in \2.  David Byers committed Dec 26, 1998 885 This rule is currently not enforced.  David Byers committed Sep 13, 1997 886 887 888 889  This item can only be set by the person himself. The hide-creator, secret and inherit bits are automatically cleared.  David Byers committed Dec 26, 1998 890   Per Cederqvist committed Aug 16, 1998 891 892 @item e-mail-address [13] (conference, letterbox, server)  David Byers committed Dec 26, 1998 893 894 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  Per Cederqvist committed Aug 16, 1998 895 896 897 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 committed Dec 26, 1998 898 899 900 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.  Per Cederqvist committed Aug 16, 1998 901 902  When this aux-item is set on the server it shold contain the email  David Byers committed Jan 18, 1999 903 address of the administrator (or administrators.)  Per Cederqvist committed Aug 16, 1998 904   David Byers committed Dec 26, 1998 905 906 907 This aux-item can only be set by the supervisor of a conference or the server administrator. The creator cannot be hidden.  Per Cederqvist committed Aug 16, 1998 908 909 910 911  @item faq-text [14] (conference, server) Data is a decimal text number, which is a FAQ for the conference (or  David Byers committed Dec 26, 1998 912 913 914 915 916 917 918 server). This aux-item can only be set by the administrator. Adding this item to a conference or to the server automatically marks the text. Deleting the item unmarks the text. This item can only be set by the supervisor or server administrator. The hide-creator, secret, and inherit bits are automatically cleared.  Per Cederqvist committed Aug 16, 1998 919 920 921 922 923 924 925 926 927 928 929 930  @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.  David Byers committed Sep 13, 1997 931   David Byers committed Jan 14, 1999 932 @item mx-author [16] (text)  Jonas S Karlsson committed Oct 11, 1998 933   David Byers committed Jan 14, 1999 934 935 936 Data is a string containing the name of the author of an imported e-mail. Clients should display this instead of the actual author of the text, which will be an importer ID.  Jonas S Karlsson committed Oct 11, 1998 937 938   David Byers committed Jan 14, 1999 939 @item mx-from [17] (text)  Jonas S Karlsson committed Oct 11, 1998 940   David Byers committed Jan 14, 1999 941 942 943 Data is the e-mail address extracted from the @code{From} header of an imported e-mail. This field can be used by clients to construct an address for personal (e-mail) replies to an imported message.  Jonas S Karlsson committed Oct 11, 1998 944 945   David Byers committed Jan 14, 1999 946 @item mx-reply-to [18] (text)  Jonas S Karlsson committed Oct 11, 1998 947   David Byers committed Jan 14, 1999 948 949 950 Data is the e-mail address extracted from the @code{Reply-To} header of an imported e-mail. Clients should use this for constructing replies to imported messages.  Jonas S Karlsson committed Oct 11, 1998 951 952   David Byers committed Jan 14, 1999 953 @item mx-to [19] (text)  Jonas S Karlsson committed Oct 11, 1998 954   David Byers committed Jan 14, 1999 955 956 957 958 Data is a single e-mail address, and must be valid as the contents of an e-mail @code{To} header. Multiple @code{mx-o} items may be present. For imported messages, these items contain the @code{To} header of the messages.  Jonas S Karlsson committed Oct 11, 1998 959   David Byers committed Jan 14, 1999 960 961 962 On messages created by a LysKOM person, the @code{mx-to} items are used by the exporter to determine that the message is to be exported and where to send it.  Jonas S Karlsson committed Oct 11, 1998 963   David Byers committed Jan 14, 1999 964 @item mx-cc [20] (text)  David Byers committed Sep 13, 1997 965   David Byers committed Jan 14, 1999 966 967 Same as @code{mx-to}, but applies to the @code{CC} header rather than the @code{To} header.  Jonas S Karlsson committed Oct 11, 1998 968   969   David Byers committed Jan 14, 1999 970 @item mx-date [21] (text)  971   David Byers committed Jan 14, 1999 972 973 974 975 976 977 978 979 980 Data is the send data of an imported e-mail. 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.  981   David Byers committed Jan 14, 1999 982 983 Clients should display this date as the date a text was written since the imported text will have been created at a later date.  984 985   David Byers committed Jan 14, 1999 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 @item mx-message-id [22] (text) Data is the @code{Message-ID} header of an imported e-mail. This is used by e-mail importers. @item mx-in-reply-to [23] (text) Data is a string containing one item from the @code{In-Reply-To} header of an imported e-mail. If the @code{In-Reply-To} header contains several items, there will be several @code{mx-in-reply-to} items. @item mx-misc [24] (text) Data is a string that contains all of the headers, including @code{Subject}, and including whose that are redundantly stored in other aux-items. It is set by the importer. The fields are concatenated with "\n". In other words, this item contains all headers of an imported e-mail as they appear in the message. @item mx-allow-filter [25] (conference)  Jonas S Karlsson committed Oct 11, 1998 1008 1009  Data is a regexp string which allows a sender (a field in the  1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 email-header) to import the message. If none is present, the text is imported. Several filters can exist, however, it is enough if one positive filter matches (OR) and none negative dissallows (AND) import. The order is of no importance. Can be set by an organizer of the conference. The regexp is case insensitive, and use a glob-pat style, it allows [^]?*+(|) as constructs. Note that "." is literal. The importer is required to check these when adding recipient of an imported text and comply. Example of usage: (positive filter) "From:*.liu.se*", "From:*jsk*". "From:*(jonas|jonka|jsk)*" Tests are not made on the text-body.  Jonas S Karlsson committed Oct 11, 1998 1022 1023  However, if the string starts with a "!" the email will be rejected if  1024 the there is a match (negative filter), even if one of the filter allowed it. Example:  Jonas S Karlsson committed Oct 11, 1998 1025 1026 "!From:*aol*", "!Subject:*money*".  David Byers committed Jan 14, 1999 1027 @item mx-reject-forward [26] (conference)  Jonas S Karlsson committed Oct 11, 1998 1028   1029 1030 Data is a string with either an email name on the same format as aux-info rediret [8]. The mail is forwarded to this address if it was  David Byers committed Jan 14, 1999 1031 rejected by "mx-import-filter".  Jonas S Karlsson committed Oct 11, 1998 1032   David Byers committed Dec 26, 1998 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 @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.  David Byers committed Sep 13, 1997 1043 1044   David Byers committed Dec 26, 1998 1045 1046 @end table  David Byers committed Sep 13, 1997 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080  @node Client-Specific Aux-Item Types, Experimental Aux-Item Types, Predefined Aux-Item Types, The Aux-Item List @subsubsection Client-Specific Aux-Item Types 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 @end itemize If you want a range of numbers, send e-mail to the LysKOM development group. @node Experimental Aux-Item Types, Defining New Aux-Item Types, Client-Specific Aux-Item Types, The Aux-Item List @subsubsection Experimental Aux-Item Types Experimental numbers are free for all. Use 'em any way you want. All numbers in the range 20000-29999 are for experimental use. @node Defining New Aux-Item Types, , Experimental Aux-Item Types, The Aux-Item List @subsubsection Defining New Aux-Item Types  Per Cederqvist committed Aug 08, 1998 1081 If you want a new predefined item type, just document what it does, what  David Byers committed Sep 13, 1997 1082 1083 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  Per Cederqvist committed Aug 08, 1998 1084 your item and put the documentation in this document.  David Byers committed Sep 13, 1997 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104  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. @node Security, Membership and Reading, The Aux-Item List, Introduction  David Byers committed Jan 13, 1996 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 @subsection Security 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 @node Membership and Reading, Client-Server Dialog, Security, Introduction @section Membership and Reading  David Byers committed Sep 13, 1997 1181 Persons' memberships in conferences are represented in the protocol as  David Byers committed Dec 29, 1998 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 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 committed Jan 13, 1996 1205 1206  Finding out which articles a person has read in a particular conference  David Byers committed Sep 13, 1997 1207 1208 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 committed Jan 13, 1996 1209 1210 1211  @enumerate @item Fetch the membership to get the @code{last-text-read}  David Byers committed Dec 29, 1998 1212 1213 1214 1215 @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 committed Jan 13, 1996 1216 1217 1218 @item Get and translate more texts as needed. @end enumerate  David Byers committed Sep 13, 1997 1219 The process is complicated because of the translation between local and  David Byers committed Dec 29, 1998 1220 global text numbers. If the server does not implement the  David Byers committed Jan 14, 1999 1221 1222 @pxref{local-to-global} call, it is possible to use the less efficient but perfectly serviceable @pxref{get-map} call instead.  David Byers committed Jan 13, 1996 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233  @node Client-Server Dialog, ,Membership and Reading , Introduction @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 committed Sep 13, 1997 1234 1235 1236 1237 network port@footnote{The default port for a LysKOM server is 4894} and sending a single letter which is used to select a protocol version followed by connection information required by that protocol. In protocol A the connection information is a Hollerith string saying who  Per Cederqvist committed Aug 08, 1998 1238 the user connecting is followed by a newline character.  David Byers committed Jan 13, 1996 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252  When the server has accepted the connection its reply is protocol-dependent. Protocol A servers will reply with the string @code{LysKOM} on a single line. @example % telnet kom.lysator.liu.se Trying 130.236.254.151 ... Connected to varg.lysator.liu.se. Escape character is '^]'. A5Hbyers LysKOM @end example  David Byers committed Sep 13, 1997 1253 1254 1255 After connecting, calls to the server can be made. Most calls require the user to log in, but some calls can be made without a log-in. Calls to the server are made by sending a reference number followed by the  David Byers committed Jan 18, 1999 1256 1257 call as specified. The call @i{must} be terminated with a linefeed character (ASCII 0x0A).  David Byers committed Jan 13, 1996 1258 1259 1260 1261 1262 1263 1264 1265  @example server-call ::= ( ref-no : INT32; request : Protocol-Request; ) @end example  David Byers committed Sep 13, 1997 1266 1267 1268 At some future point the server will reply with the result of the request or an error code preceded by an indicator and the reference number.  David Byers committed Jan 13, 1996 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282  @example server-reply ::= ok-reply | error-reply; ok-reply ::= ( "=" ref-no : INT32; reply-data; ) error-reply ::= ( "%" ref-no : INT32; error-no : Error-No;  David Byers committed Sep 13, 1997 1283  error-status : INT32;  David Byers committed Jan 13, 1996 1284 1285 1286 1287 1288 1289  ) error-no ::= INT32; @end example Our notation is not flexible enough to specify the two-way nature of the  David Byers committed Sep 13, 1997 1290 1291 1292 1293 1294 1295 communication. @code{ref-no} in the reply is always the same as @code{ref-no} in the corresponding request. @code{reply-data} depends on which request was made and is specified together with each request. Please note that there is no whitespace after the initial indicator in the reply.  David Byers committed Jan 13, 1996 1296   David Byers committed Sep 13, 1997 1297 Error reporting is covered in more detail in chapter @ref{Error Codes}.  David Byers committed Jan 13, 1996 1298 1299   David Byers committed Jan 15, 1999 1300 @node Data Types, Protocol Requests, Introduction, Top  David Byers committed Jan 13, 1996 1301 1302 @chapter Data Types  David Byers committed Sep 13, 1997 1303 1304 1305 1306 The data types in protocol A come in two flavors. The first (vanilla) are the simple data types from which the LysKOM (chocolate) data types are built. Simple data types include things like integers and strings while complex data types include things such as conferences and people.  David Byers committed Jan 13, 1996 1307 1308 1309 1310  @menu * Simple Data Types:: * LysKOM Data Types::  David Byers committed Sep 13, 1997 1311 * Name Expansion::  David Byers committed Jan 13, 1996 1312 1313 1314 1315 1316 @end menu @node Simple Data Types, LysKOM Data Types, Data Types, Data Types @section Simple Data Types  David Byers committed Jan 18, 1999 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 Data elements sent from the client to the server are separated by one or more space characters (ASCII 32). An entire call is terminated by a linefeed character (ASCII 10). Earlier versions of the protocol specified that data elements could be separated by any number of linefeed (ASCII 10), return (ASCII 13), tab (ASCII 9) or space (ASCII 32) characters. Servers should be forgiving and understand requests using the older conventions, but clients must conform to the current convention of separating data elements with spaces and terminating all requests with a linefeed character.  David Byers committed Jan 13, 1996 1327 1328 1329 1330  @subsection Integers  Per Cederqvist committed Aug 22, 1998 1331 1332 1333 1334 @tindex INT32 @tindex INT16 @tindex INT8 @tindex BOOL  David Byers committed Sep 13, 1997 1335 1336 1337 @dfn{INT32}, @dfn{INT16}, @dfn{INT8} and @dfn{BOOL} are non-negative integers which must fit in 32, 16, 8 and 1 bits, respectively. They are transmitted to the server in ASCII-encoded decimal notation.  David Byers committed Jan 13, 1996 1338 1339 1340 1341  @subsection Strings  Per Cederqvist committed Aug 22, 1998 1342 @tindex HOLLERITH  David Byers committed Jan 13, 1996 1343 1344 1345 @dfn{HOLLERITH} denotes character strings of arbitrary length. They are transmitted as @code{H} where @code{} is the string and @code{} is the number of characters in @code{} in decimal  David Byers committed Sep 13, 1997 1346 1347 1348 1349 notation. All byte values are allowed in the string itself, including nulls. Long live FORTRAN!  David Byers committed Jan 13, 1996 1350 1351 1352 1353 1354  @subsection Bit Strings  Per Cederqvist committed Aug 22, 1998 1355 @tindex BITSTRING  David Byers committed Sep 13, 1997 1356 1357 @dfn{BITSTRING} is a string of bits, commonly used for a set of boolean-valued flags. Bit strings are denoted as  David Byers committed Jan 13, 1996 1358 1359 1360 1361 1362  @example BITSTRING ( name-1; name-2; name-3; ... ) @end example  David Byers committed Sep 13, 1997 1363 1364 in this specification. They are transmitted as a sequence of ASCII ones and zeroes in the order the fields are listed.  David Byers committed Jan 13, 1996 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376  For instance, given the specification @example shape-of-world : BITSTRING ( is-flat; is-round; is-2d; is-3d; ) @end example  David Byers committed Sep 13, 1997 1377 1378 most peoples idea of @code{shape-of-world} would be sent as @code{0101} (round and three-dimensional.)