1
2This is a distribution of both client and server telnet. These programs
3have been compiled on:
4 telnet telnetd
5 BSD 4.4 x x
6 BSD 4.3 Reno X X
7 UNICOS 8.0 X X
8 UNICOS 7.C X X
9 UNICOS 7.0 X X
10 UNICOS 6.1 X X
11 BSDI 1.0 X X
12 Solaris 2.2 x x (no linemode in server)
13 Solaris 2.3 x x (no linemode in server)
14 SunOs 4.1.3 X X (no linemode in server)
15 Ultrix 4.3 X X (no linemode in server)
16 DYNIX V3.0.17.9 X X (no linemode in server)
17 HP-UX 8.0 x x (no linemode in server)
18
19In addition, previous versions have been compiled on the following
20machines, but were not available for testing this version.
21 telnet telnetd
22 Next1.0 X X
23 UNICOS 6.0 X X
24 UNICOS 5.1 X X
25 UNICOS 5.0 X X
26 SunOs 4.0.3c X X (no linemode in server)
27 BSD 4.3 X X (no linemode in server)
28 DYNIX V3.0.12 X X (no linemode in server)
29 Ultrix 3.1 X X (no linemode in server)
30 Ultrix 4.0 X X (no linemode in server)
31 SunOs 3.5 X X (no linemode in server)
32
33This code should work, but there are no guarantees.
34
35January 19, 1994
36
37This is a list of some of the changes since the last tar release
38of telnet/telnetd. There are probably other changes that aren't
39listed here, but this should hit a lot of the main ones.
40
41 General:
42 Changed #define for AUTHENTICATE to AUTHENTICATION
43 Changed #define for ENCRYPT to ENCRYPTION
44 Changed #define for DES_ENCRYPT to DES_ENCRYPTION
45
46 Added support for SPX authentication: -DSPX
47
48 Added support for Kerberos Version 5 authentication: -DKRB5
49
50 Added support for ANSI C function prototypes
51
52 Added support for the NEW-ENVIRON option (RFC-1572)
53 including support for USERVAR.
54
55 Made support for the old Environment Option (RFC-1408)
56 conditional on -DOLD_ENVIRON
57
58 Added #define ENV_HACK - support for RFC 1571
59
60 The encryption code is removed from the public distributions.
61 Domestic 4.4 BSD distributions contain the encryption code.
62
63 ENV_HACK: Code to deal with systems that only implement
64 the old ENVIRON option, and have reversed definitions
65 of ENV_VAR and ENV_VAL. Also fixes ENV processing in
66 client to handle things besides just the default set...
67
68 NO_BSD_SETJMP: UNICOS configuration for
69 UNICOS 6.1/6.0/5.1/5.0 systems.
70
71 STREAMSPTY: Use /dev/ptmx to get a clean pty. This
72 is for SVr4 derivatives (Like Solaris)
73
74 UTMPX: For systems that have /etc/utmpx. This is for
75 SVr4 derivatives (Like Solaris)
76
77 Definitions for BSDI 1.0
78
79 Definitions for 4.3 Reno and 4.4 BSD.
80
81 Definitions for UNICOS 8.0 and UNICOS 7.C
82
83 Definitions for Solaris 2.0
84
85 Definitions for HP-UX 8.0
86
87 Latest Copyright notices from Berkeley.
88
89 FLOW-CONTROL: support for RFC-XXXx
90
91
92 Client Specific:
93
94 Fix the "send" command to not send garbage...
95
96 Fix status message for "skiprc"
97
98 Make sure to send NAWS after telnet has been suspended
99 or an external command has been run, if the window size
100 has changed.
101
102 sysV88 support.
103
104 Server Specific:
105
106 Support flowcontrol option in non-linemode servers.
107
108 -k Server supports Kludge Linemode, but will default to
109 either single character mode or real Linemode support.
110 The user will have to explicitly ask to switch into
111 kludge linemode. ("stty extproc", or escape back to
112 to telnet and say "mode line".)
113
114 -u Specify the length of the hostname field in the utmp
115 file. Hostname longer than this length will be put
116 into the utmp file in dotted decimal notation, rather
117 than putting in a truncated hostname.
118
119 -U Registered hosts only. If a reverse hostname lookup
120 fails, the connection will be refused.
121
122 -f/-F
123 Allows forwarding of credentials for KRB5.
124
125Februrary 22, 1991:
126
127 Features:
128
129 This version of telnet/telnetd has support for both
130 the AUTHENTICATION and ENCRYPTION options. The
131 AUTHENTICATION option is fairly well defined, and
132 an option number has been assigned to it. The
133 ENCRYPTION option is still in a state of flux; an
134 option number has been assigned to, but it is still
135 subject to change. The code is provided in this release
136 for experimental and testing purposes.
137
138 The telnet "send" command can now be used to send
139 do/dont/will/wont commands, with any telnet option
140 name. The rules for when do/dont/will/wont are sent
141 are still followed, so just because the user requests
142 that one of these be sent doesn't mean that it will
143 be sent...
144
145 The telnet "getstatus" command no longer requires
146 that option printing be enabled to see the response
147 to the "DO STATUS" command.
148
149 A -n flag has been added to telnetd to disable
150 keepalives.
151
152 A new telnet command, "auth" has been added (if
153 AUTHENTICATE is defined). It has four sub-commands,
154 "status", "disable", "enable" and "help".
155
156 A new telnet command, "encrypt" has been added (if
157 ENCRYPT is defined). It has many sub-commands:
158 "enable", "type", "start", "stop", "input",
159 "-input", "output", "-output", "status", and "help".
160
161 The LOGOUT option is now supported by both telnet
162 and telnetd, a new command, "logout", was added
163 to support this.
164
165 Several new toggle options were added:
166 "autoencrypt", "autodecrypt", "autologin", "authdebug",
167 "encdebug", "skiprc", "verbose_encrypt"
168
169 An "rlogin" interface has been added. If the program
170 is named "rlogin", or the "-r" flag is given, then
171 an rlogin type of interface will be used.
172 ~. Terminates the session
173 ~<susp> Suspend the session
174 ~^] Escape to telnet command mode
175 ~~ Pass through the ~.
176 BUG: If you type the rlogin escape character
177 in the middle of a line while in rlogin
178 mode, you cannot erase it or any characters
179 before it. Hopefully this can be fixed
180 in a future release...
181
182 General changes:
183
184 A "libtelnet.a" has now been created. This libraray
185 contains code that is common to both telnet and
186 telnetd. This is also where library routines that
187 are needed, but are not in the standard C library,
188 are placed.
189
190 The makefiles have been re-done. All of the site
191 specific configuration information has now been put
192 into a single "Config.generic" file, in the top level
193 directory. Changing this one file will take care of
194 all three subdirectories. Also, to add a new/local
195 definition, a "Config.local" file may be created
196 at the top level; if that file exists, the subdirectories
197 will use that file instead of "Config.generic".
198
199 Many 1-2 line functions in commands.c have been
200 removed, and just inserted in-line, or replaced
201 with a macro.
202
203 Bug Fixes:
204
205 The non-termio code in both telnet and telnetd was
206 setting/clearing CTLECH in the sg_flags word. This
207 was incorrect, and has been changed to set/clear the
208 LCTLECH bit in the local mode word.
209
210 The SRCRT #define has been removed. If IP_OPTIONS
211 and IPPROTO_IP are defined on the system, then the
212 source route code is automatically enabled.
213
214 The NO_GETTYTAB #define has been removed; there
215 is a compatability routine that can be built into
216 libtelnet to achive the same results.
217
218 The server, telnetd, has been switched to use getopt()
219 for parsing the argument list.
220
221 The code for getting the input/output speeds via
222 cfgetispeed()/cfgetospeed() was still not quite
223 right in telnet. Posix says if the ispeed is 0,
224 then it is really equal to the ospeed.
225
226 The suboption processing code in telnet now has
227 explicit checks to make sure that we received
228 the entire suboption (telnetd was already doing this).
229
230 The telnet code for processing the terminal type
231 could cause a core dump if an existing connection
232 was closed, and a new connection opened without
233 exiting telnet.
234
235 Telnetd was doing a TCSADRAIN when setting the new
236 terminal settings; This is not good, because it means
237 that the tcsetattr() will hang waiting for output to
238 drain, and telnetd is the only one that will drain
239 the output... The fix is to use TCSANOW which does
240 not wait.
241
242 Telnetd was improperly setting/clearing the ISTRIP
243 flag in the c_lflag field, it should be using the
244 c_iflag field.
245
246 When the child process of telnetd was opening the
247 slave side of the pty, it was re-setting the EXTPROC
248 bit too early, and some of the other initialization
249 code was wiping it out. This would cause telnetd
250 to go out of linemode and into single character mode.
251
252 One instance of leaving linemode in telnetd forgot
253 to send a WILL ECHO to the client, the net result
254 would be that the user would see double character
255 echo.
256
257 If the MODE was being changed several times very
258 quickly, telnetd could get out of sync with the
259 state changes and the returning acks; and wind up
260 being left in the wrong state.
261
262September 14, 1990:
263
264 Switch the client to use getopt() for parsing the
265 argument list. The 4.3Reno getopt.c is included for
266 systems that don't have getopt().
267
268 Use the posix _POSIX_VDISABLE value for what value
269 to use when disabling special characters. If this
270 is undefined, it defaults to 0x3ff.
271
272 For non-termio systems, TIOCSETP was being used to
273 change the state of the terminal. This causes the
274 input queue to be flushed, which we don't want. This
275 is now changed to TIOCSETN.
276
277 Take out the "#ifdef notdef" around the code in the
278 server that generates a "sync" when the pty oputput
279 is flushed. The potential problem is that some older
280 telnet clients may go into an infinate loop when they
281 receive a "sync", if so, the server can be compiled
282 with "NO_URGENT" defined.
283
284 Fix the client where it was setting/clearing the OPOST
285 bit in the c_lflag field, not the c_oflag field.
286
287 Fix the client where it was setting/clearing the ISTRIP
288 bit in the c_lflag field, not the c_iflag field. (On
289 4.3Reno, this is the ECHOPRT bit in the c_lflag field.)
290 The client also had its interpretation of WILL BINARY
291 and DO BINARY reversed.
292
293 Fix a bug in client that would cause a core dump when
294 attempting to remove the last environment variable.
295
296 In the client, there were a few places were switch()
297 was being passed a character, and if it was a negative
298 value, it could get sign extended, and not match
299 the 8 bit case statements. The fix is to and the
300 switch value with 0xff.
301
302 Add a couple more printoption() calls in the client, I
303 don't think there are any more places were a telnet
304 command can be received and not printed out when
305 "options" is on.
306
307 A new flag has been added to the client, "-a". Currently,
308 this just causes the USER name to be sent across, in
309 the future this may be used to signify that automatic
310 authentication is requested.
311
312 The USER variable is now only sent by the client if
313 the "-a" or "-l user" options are explicity used, or
314 if the user explicitly asks for the "USER" environment
315 variable to be exported. In the server, if it receives
316 the "USER" environment variable, it won't print out the
317 banner message, so that only "Password:" will be printed.
318 This makes the symantics more like rlogin, and should be
319 more familiar to the user. (People are not used to
320 getting a banner message, and then getting just a
321 "Password:" prompt.)
322
323 Re-vamp the code for starting up the child login
324 process. The code was getting ugly, and it was
325 hard to tell what was really going on. What we
326 do now is after the fork(), in the child:
327 1) make sure we have no controlling tty
328 2) open and initialize the tty
329 3) do a setsid()/setpgrp()
330 4) makes the tty our controlling tty.
331 On some systems, #2 makes the tty our controlling
332 tty, and #4 is a no-op. The parent process does
333 a gets rid of any controlling tty after the child
334 is fork()ed.
335
336 Use the strdup() library routine in telnet, instead
337 of the local savestr() routine. If you don't have
338 strdup(), you need to define NO_STRDUP.
339
340 Add support for ^T (SIGINFO/VSTATUS), found in the
341 4.3Reno distribution. This maps to the AYT character.
342 You need a 4-line bugfix in the kernel to get this
343 to work properly:
344
345 > *** tty_pty.c.ORG Tue Sep 11 09:41:53 1990
346 > --- tty_pty.c Tue Sep 11 17:48:03 1990
347 > ***************
348 > *** 609,613 ****
349 > if ((tp->t_lflag&NOFLSH) == 0)
350 > ttyflush(tp, FREAD|FWRITE);
351 > ! pgsignal(tp->t_pgrp, *(unsigned int *)data);
352 > return(0);
353 > }
354 > --- 609,616 ----
355 > if ((tp->t_lflag&NOFLSH) == 0)
356 > ttyflush(tp, FREAD|FWRITE);
357 > ! pgsignal(tp->t_pgrp, *(unsigned int *)data, 1);
358 > ! if ((*(unsigned int *)data == SIGINFO) &&
359 > ! ((tp->t_lflag&NOKERNINFO) == 0))
360 > ! ttyinfo(tp);
361 > return(0);
362 > }
363
364 The client is now smarter when setting the telnet escape
365 character; it only sets it to one of VEOL and VEOL2 if
366 one of them is undefined, and the other one is not already
367 defined to the telnet escape character.
368
369 Handle TERMIOS systems that have seperate input and output
370 line speed settings imbedded in the flags.
371
372 Many other minor bug fixes.
373
374June 20, 1990:
375 Re-organize makefiles and source tree. The telnet/Source
376 directory is now gone, and all the source that was in
377 telnet/Source is now just in the telnet directory.
378
379 Seperate makefile for each system are now gone. There
380 are two makefiles, Makefile and Makefile.generic.
381 The "Makefile" has the definitions for the various
382 system, and "Makefile.generic" does all the work.
383 There is a variable called "WHAT" that is used to
384 specify what to make. For example, in the telnet
385 directory, you might say:
386 make 4.4bsd WHAT=clean
387 to clean out the directory.
388
389 Add support for the ENVIRON and XDISPLOC options.
390 In order for the server to work, login has to have
391 the "-p" option to preserve environment variables.
392
393 Add the SOFT_TAB and LIT_ECHO modes in the LINEMODE support.
394
395 Add the "-l user" option to command line and open command
396 (This is passed through the ENVIRON option).
397
398 Add the "-e" command line option, for setting the escape
399 character.
400
401 Add the "-D", diagnostic, option to the server. This allows
402 the server to print out debug information, which is very
403 useful when trying to debug a telnet that doesn't have any
404 debugging ability.
405
406 Turn off the literal next character when not in LINEMODE.
407
408 Don't recognize ^Y locally, just pass it through.
409
410 Make minor modifications for Sun4.0 and Sun4.1
411
412 Add support for both FORW1 and FORW2 characters. The
413 telnet escpape character is set to whichever of the
414 two is not being used. If both are in use, the escape
415 character is not set, so when in linemode the user will
416 have to follow the escape character with a <CR> or <EOF)
417 to get it passed through.
418
419 Commands can now be put in single and double quotes, and
420 a backslash is now an escape character. This is needed
421 for allowing arbitrary strings to be assigned to environment
422 variables.
423
424 Switch telnetd to use macros like telnet for keeping
425 track of the state of all the options.
426
427 Fix telnetd's processing of options so that we always do
428 the right processing of the LINEMODE option, regardless
429 of who initiates the request to turn it on. Also, make
430 sure that if the other side went "WILL ECHO" in response
431 to our "DO ECHO", that we send a "DONT ECHO" to get the
432 option turned back off!
433
434 Fix the TERMIOS setting of the terminal speed to handle both
435 BSD's seperate fields, and the SYSV method of CBAUD bits.
436
437 Change how we deal with the other side refusing to enable
438 an option. The sequence used to be: send DO option; receive
439 WONT option; send DONT option. Now, the sequence is: send
440 DO option; receive WONT option. Both should be valid
441 according to the spec, but there has been at least one
442 client implementation of telnet identified that can get
443 really confused by this. (The exact sequence, from a trace
444 on the server side, is (numbers are number of responses that
445 we expect to get after that line...):
446
447 send WILL ECHO 1 (initial request)
448 send WONT ECHO 2 (server is changing state)
449 recv DO ECHO 1 (first reply, ok. expect DONT ECHO next)
450 send WILL ECHO 2 (server changes state again)
451 recv DONT ECHO 1 (second reply, ok. expect DO ECHO next)
452 recv DONT ECHO 0 (third reply, wrong answer. got DONT!!!)
453 *** send WONT ECHO (send WONT to acknowledge the DONT)
454 send WILL ECHO 1 (ask again to enable option)
455 recv DO ECHO 0
456
457 recv DONT ECHO 0
458 send WONT ECHO 1
459 recv DONT ECHO 0
460 recv DO ECHO 1
461 send WILL ECHO 0
462 (and the last 5 lines loop forever)
463
464 The line with the "***" is last of the WILL/DONT/WONT sequence.
465 The change to the server to not generate that makes this same
466 example become:
467
468 send will ECHO 1
469 send wont ECHO 2
470 recv do ECHO 1
471 send will ECHO 2
472 recv dont ECHO 1
473 recv dont ECHO 0
474 recv do ECHO 1
475 send will ECHO 0
476
477 There is other option negotiation going on, and not sending
478 the third part changes some of the timings, but this specific
479 example no longer gets stuck in a loop. The "telnet.state"
480 file has been modified to reflect this change to the algorithm.
481
482 A bunch of miscellaneous bug fixes and changes to make
483 lint happier.
484
485 This version of telnet also has some KERBEROS stuff in
486 it. This has not been tested, it uses an un-authorized
487 telnet option number, and uses an out-of-date version
488 of the (still being defined) AUTHENTICATION option.
489 There is no support for this code, do not enable it.
490
491
492March 1, 1990:
493CHANGES/BUGFIXES SINCE LAST RELEASE:
494 Some support for IP TOS has been added. Requires that the
495 kernel support the IP_TOS socket option (currently this
496 is only in UNICOS 6.0).
497
498 Both telnet and telnetd now use the cc_t typedef. typedefs are
499 included for systems that don't have it (in termios.h).
500
501 SLC_SUSP was not supported properly before. It is now.
502
503 IAC EOF was not translated properly in telnetd for SYSV_TERMIO
504 when not in linemode. It now saves a copy of the VEOF character,
505 so that when ICANON is turned off and we can't trust it anymore
506 (because it is now the VMIN character) we use the saved value.
507
508 There were two missing "break" commands in the linemode
509 processing code in telnetd.
510
511 Telnetd wasn't setting the kernel window size information
512 properly. It was using the rows for both rows and columns...
513
514Questions/comments go to
515 David Borman
516 Cray Research, Inc.
517 655F Lone Oak Drive
518 Eagan, MN 55123
519 dab@cray.com.
520
521README: You are reading it.
522
523Config.generic:
524 This file contains all the OS specific definitions. It
525 has pre-definitions for many common system types, and is
526 in standard makefile fromat. See the comments at the top
527 of the file for more information.
528
529Config.local:
530 This is not part of the distribution, but if this file exists,
531 it is used instead of "Config.generic". This allows site
532 specific configuration without having to modify the distributed
533 "Config.generic" file.
534
535kern.diff:
536 This file contains the diffs for the changes needed for the
537 kernel to support LINEMODE is the server. These changes are
538 for a 4.3BSD system. You may need to make some changes for
539 your particular system.
540
541 There is a new bit in the terminal state word, TS_EXTPROC.
542 When this bit is set, several aspects of the terminal driver
543 are disabled. Input line editing, character echo, and
544 mapping of signals are all disabled. This allows the telnetd
545 to turn of these functions when in linemode, but still keep
546 track of what state the user wants the terminal to be in.
547
548 New ioctl()s:
549
550 TIOCEXT Turn on/off the TS_EXTPROC bit
551 TIOCGSTATE Get t_state of tty to look at TS_EXTPROC bit
552 TIOCSIG Generate a signal to processes in the
553 current process group of the pty.
554
555 There is a new mode for packet driver, the TIOCPKT_IOCTL bit.
556 When packet mode is turned on in the pty, and the TS_EXTPROC
557 bit is set, then whenever the state of the pty is changed, the
558 next read on the master side of the pty will have the TIOCPKT_IOCTL
559 bit set, and the data will contain the following:
560 struct xx {
561 struct sgttyb a;
562 struct tchars b;
563 struct ltchars c;
564 int t_state;
565 int t_flags;
566 }
567 This allows the process on the server side of the pty to know
568 when the state of the terminal has changed, and what the new
569 state is.
570
571 However, if you define USE_TERMIO or SYSV_TERMIO, the code will
572 expect that the structure returned in the TIOCPKT_IOCTL is
573 the termio/termios structure.
574
575stty.diff:
576 This file contains the changes needed for the stty(1) program
577 to report on the current status of the TS_EXTPROC bit. It also
578 allows the user to turn on/off the TS_EXTPROC bit. This is useful
579 because it allows the user to say "stty -extproc", and the
580 LINEMODE option will be automatically disabled, and saying "stty
581 extproc" will re-enable the LINEMODE option.
582
583telnet.state:
584 Both the client and server have code in them to deal
585 with option negotiation loops. The algorithm that is
586 used is described in this file.
587
588telnet:
589 This directory contains the client code. No kernel changes are
590 needed to use this code.
591
592telnetd:
593 This directory contains the server code. If LINEMODE or KLUDGELINEMODE
594 are defined, then the kernel modifications listed above are needed.
595
596libtelnet:
597 This directory contains code that is common to both the client
598 and the server.
599
600arpa:
601 This directory has a new <arpa/telnet.h>
602
603libtelnet/Makefile.4.4:
604telnet/Makefile.4.4:
605telnetd/Makefile.4.4:
606 These are the makefiles that can be used on a 4.3Reno
607 system when this software is installed in /usr/src/lib/libtelnet,
608 /usr/src/libexec/telnetd, and /usr/src/usr.bin/telnet.
609
610
611The following TELNET options are supported:
612
613 LINEMODE:
614 The LINEMODE option is supported as per RFC1116. The
615 FORWARDMASK option is not currently supported.
616
617 BINARY: The client has the ability to turn on/off the BINARY
618 option in each direction. Turning on BINARY from
619 server to client causes the LITOUT bit to get set in
620 the terminal driver on both ends, turning on BINARY
621 from the client to the server causes the PASS8 bit
622 to get set in the terminal driver on both ends.
623
624 TERMINAL-TYPE:
625 This is supported as per RFC1091. On the server side,
626 when a terminal type is received, termcap/terminfo
627 is consulted to determine if it is a known terminal
628 type. It keeps requesting terminal types until it
629 gets one that it recongnizes, or hits the end of the
630 list. The server side looks up the entry in the
631 termcap/terminfo data base, and generates a list of
632 names which it then passes one at a time to each
633 request for a terminal type, duplicating the last
634 entry in the list before cycling back to the beginning.
635
636 NAWS: The Negotiate about Window Size, as per RFC 1073.
637
638 TERMINAL-SPEED:
639 Implemented as per RFC 1079
640
641 TOGGLE-FLOW-CONTROL:
642 Implemented as per RFC 1080
643
644 TIMING-MARK:
645 As per RFC 860
646
647 SGA: As per RFC 858
648
649 ECHO: As per RFC 857
650
651 LOGOUT: As per RFC 727
652
653 STATUS:
654 The server will send its current status upon
655 request. It does not ask for the clients status.
656 The client will request the servers current status
657 from the "send getstatus" command.
658
659 ENVIRON:
660 This option is currently being defined by the IETF
661 Telnet Working Group, and an RFC has not yet been
662 issued, but should be in the near future...
663
664 X-DISPLAY-LOCATION:
665 This functionality can be done through the ENVIRON
666 option, it is added here for completeness.
667
668 AUTHENTICATION:
669 This option is currently being defined by the IETF
670 Telnet Working Group, and an RFC has not yet been
671 issued. The basic framework is pretty much decided,
672 but the definitions for the specific authentication
673 schemes is still in a state of flux.
674
675 ENCRYPTION:
676 This option is currently being defined by the IETF
677 Telnet Working Group, and an RFC has not yet been
678 issued. The draft RFC is still in a state of flux,
679 so this code may change in the future.
680