17 #define IAC 255 /* interpret as command: */
18 #define DONT 254 /* you are not to use option */
19 #define DO 253 /* please, you use option */
20 #define WONT 252 /* I won't use option */
21 #define WILL 251 /* I will use option */
22 #define SB 250 /* interpret as subnegotiation */
23 #define SE 240 /* end sub negotiation */
25 #define GA 249 /* you may reverse the line */
26 #define EL 248 /* erase the current line */
27 #define EC 247 /* erase the current character */
28 #define AYT 246 /* are you there */
29 #define AO 245 /* abort output--but let prog finish */
30 #define IP 244 /* interrupt process--permanently */
31 #define BREAK 243 /* break */
32 #define DM 242 /* data mark--for connect. cleaning */
33 #define NOP 241 /* nop */
34 #define EOR 239 /* end of record (transparent mode) */
35 #define ABORT 238 /* Abort process */
36 #define SUSP 237 /* Suspend process */
37 #define xEOF 236 /* End of file: EOF is already used... */
40 X(BINARY, 0) /* 8-bit data path */ \
41 X(ECHO, 1) /* echo */ \
42 X(RCP, 2) /* prepare to reconnect */ \
43 X(SGA, 3) /* suppress go ahead */ \
44 X(NAMS, 4) /* approximate message size */ \
45 X(STATUS, 5) /* give status */ \
46 X(TM, 6) /* timing mark */ \
47 X(RCTE, 7) /* remote controlled transmission and echo */ \
48 X(NAOL, 8) /* negotiate about output line width */ \
49 X(NAOP, 9) /* negotiate about output page size */ \
50 X(NAOCRD, 10) /* negotiate about CR disposition */ \
51 X(NAOHTS, 11) /* negotiate about horizontal tabstops */ \
52 X(NAOHTD, 12) /* negotiate about horizontal tab disposition */ \
53 X(NAOFFD, 13) /* negotiate about formfeed disposition */ \
54 X(NAOVTS, 14) /* negotiate about vertical tab stops */ \
55 X(NAOVTD, 15) /* negotiate about vertical tab disposition */ \
56 X(NAOLFD, 16) /* negotiate about output LF disposition */ \
57 X(XASCII, 17) /* extended ascic character set */ \
58 X(LOGOUT, 18) /* force logout */ \
59 X(BM, 19) /* byte macro */ \
60 X(DET, 20) /* data entry terminal */ \
61 X(SUPDUP, 21) /* supdup protocol */ \
62 X(SUPDUPOUTPUT, 22) /* supdup output */ \
63 X(SNDLOC, 23) /* send location */ \
64 X(TTYPE, 24) /* terminal type */ \
65 X(EOR, 25) /* end or record */ \
66 X(TUID, 26) /* TACACS user identification */ \
67 X(OUTMRK, 27) /* output marking */ \
68 X(TTYLOC, 28) /* terminal location number */ \
69 X(3270REGIME, 29) /* 3270 regime */ \
70 X(X3PAD, 30) /* X.3 PAD */ \
71 X(NAWS, 31) /* window size */ \
72 X(TSPEED, 32) /* terminal speed */ \
73 X(LFLOW, 33) /* remote flow control */ \
74 X(LINEMODE, 34) /* Linemode option */ \
75 X(XDISPLOC, 35) /* X Display Location */ \
76 X(OLD_ENVIRON, 36) /* Old - Environment variables */ \
77 X(AUTHENTICATION, 37) /* Authenticate */ \
78 X(ENCRYPT, 38) /* Encryption option */ \
79 X(NEW_ENVIRON, 39) /* New - Environment variables */ \
80 X(TN3270E, 40) /* TN3270 enhancements */ \
82 X(CHARSET, 42) /* Character set */ \
83 X(RSP, 43) /* Remote serial port */ \
84 X(COM_PORT_OPTION, 44) /* Com port control */ \
85 X(SLE, 45) /* Suppress local echo */ \
86 X(STARTTLS, 46) /* Start TLS */ \
87 X(KERMIT, 47) /* Automatic Kermit file transfer */ \
90 X(PRAGMA_LOGON, 138) \
92 X(PRAGMA_HEARTBEAT, 140) \
93 X(EXOPL, 255) /* extended-options-list */
95 #define telnet_enum(x,y) TELOPT_##x = y,
96 enum { TELOPTS(telnet_enum
) dummy
=0 };
99 #define TELQUAL_IS 0 /* option is... */
100 #define TELQUAL_SEND 1 /* send option */
101 #define TELQUAL_INFO 2 /* ENVIRON: informational version of IS */
111 #define iswritable(x) \
113 (telnet->opt_states[o_we_bin.index] == ACTIVE || (x) != CR))
115 static char *telopt(int opt
)
117 #define telnet_str(x,y) case TELOPT_##x: return #x;
126 static void telnet_size(void *handle
, int width
, int height
);
129 int send
; /* what we initially send */
130 int nsend
; /* -ve send if requested to stop it */
131 int ack
, nak
; /* +ve and -ve acknowledgements */
132 int option
; /* the option code */
133 int index
; /* index into telnet->opt_states[] */
135 REQUESTED
, ACTIVE
, INACTIVE
, REALLY_INACTIVE
153 static const struct Opt o_naws
=
154 { WILL
, WONT
, DO
, DONT
, TELOPT_NAWS
, OPTINDEX_NAWS
, REQUESTED
};
155 static const struct Opt o_tspeed
=
156 { WILL
, WONT
, DO
, DONT
, TELOPT_TSPEED
, OPTINDEX_TSPEED
, REQUESTED
};
157 static const struct Opt o_ttype
=
158 { WILL
, WONT
, DO
, DONT
, TELOPT_TTYPE
, OPTINDEX_TTYPE
, REQUESTED
};
159 static const struct Opt o_oenv
=
160 { WILL
, WONT
, DO
, DONT
, TELOPT_OLD_ENVIRON
, OPTINDEX_OENV
, INACTIVE
};
161 static const struct Opt o_nenv
=
162 { WILL
, WONT
, DO
, DONT
, TELOPT_NEW_ENVIRON
, OPTINDEX_NENV
, REQUESTED
};
163 static const struct Opt o_echo
=
164 { DO
, DONT
, WILL
, WONT
, TELOPT_ECHO
, OPTINDEX_ECHO
, REQUESTED
};
165 static const struct Opt o_we_sga
=
166 { WILL
, WONT
, DO
, DONT
, TELOPT_SGA
, OPTINDEX_WE_SGA
, REQUESTED
};
167 static const struct Opt o_they_sga
=
168 { DO
, DONT
, WILL
, WONT
, TELOPT_SGA
, OPTINDEX_THEY_SGA
, REQUESTED
};
169 static const struct Opt o_we_bin
=
170 { WILL
, WONT
, DO
, DONT
, TELOPT_BINARY
, OPTINDEX_WE_BIN
, INACTIVE
};
171 static const struct Opt o_they_bin
=
172 { DO
, DONT
, WILL
, WONT
, TELOPT_BINARY
, OPTINDEX_THEY_BIN
, INACTIVE
};
174 static const struct Opt
*const opts
[] = {
175 &o_naws
, &o_tspeed
, &o_ttype
, &o_oenv
, &o_nenv
, &o_echo
,
176 &o_we_sga
, &o_they_sga
, &o_we_bin
, &o_they_bin
, NULL
179 typedef struct telnet_tag
{
180 const struct plug_function_table
*fn
;
181 /* the above field _must_ be first in the structure */
187 int term_width
, term_height
;
189 int opt_states
[NUM_OPTS
];
191 int echoing
, editing
;
196 unsigned char *sb_buf
;
200 TOP_LEVEL
, SEENIAC
, SEENWILL
, SEENWONT
, SEENDO
, SEENDONT
,
201 SEENSB
, SUBNEGOT
, SUBNEG_IAC
, SEENCR
209 #define TELNET_MAX_BACKLOG 4096
211 #define SB_DELTA 1024
213 static void c_write(Telnet telnet
, char *buf
, int len
)
216 backlog
= from_backend(telnet
->frontend
, 0, buf
, len
);
217 sk_set_frozen(telnet
->s
, backlog
> TELNET_MAX_BACKLOG
);
220 static void log_option(Telnet telnet
, char *sender
, int cmd
, int option
)
224 * The strange-looking "<?""?>" below is there to avoid a
225 * trigraph - a double question mark followed by > maps to a
226 * closing brace character!
228 buf
= dupprintf("%s:\t%s %s", sender
,
229 (cmd
== WILL ?
"WILL" : cmd
== WONT ?
"WONT" :
230 cmd
== DO ?
"DO" : cmd
== DONT ?
"DONT" : "<?""?>"),
232 logevent(telnet
->frontend
, buf
);
236 static void send_opt(Telnet telnet
, int cmd
, int option
)
243 telnet
->bufsize
= sk_write(telnet
->s
, (char *)b
, 3);
244 log_option(telnet
, "client", cmd
, option
);
247 static void deactivate_option(Telnet telnet
, const struct Opt
*o
)
249 if (telnet
->opt_states
[o
->index
] == REQUESTED
||
250 telnet
->opt_states
[o
->index
] == ACTIVE
)
251 send_opt(telnet
, o
->nsend
, o
->option
);
252 telnet
->opt_states
[o
->index
] = REALLY_INACTIVE
;
256 * Generate side effects of enabling or disabling an option.
258 static void option_side_effects(Telnet telnet
, const struct Opt
*o
, int enabled
)
260 if (o
->option
== TELOPT_ECHO
&& o
->send
== DO
)
261 telnet
->echoing
= !enabled
;
262 else if (o
->option
== TELOPT_SGA
&& o
->send
== DO
)
263 telnet
->editing
= !enabled
;
264 if (telnet
->ldisc
) /* cause ldisc to notice the change */
265 ldisc_send(telnet
->ldisc
, NULL
, 0, 0);
267 /* Ensure we get the minimum options */
268 if (!telnet
->activated
) {
269 if (telnet
->opt_states
[o_echo
.index
] == INACTIVE
) {
270 telnet
->opt_states
[o_echo
.index
] = REQUESTED
;
271 send_opt(telnet
, o_echo
.send
, o_echo
.option
);
273 if (telnet
->opt_states
[o_we_sga
.index
] == INACTIVE
) {
274 telnet
->opt_states
[o_we_sga
.index
] = REQUESTED
;
275 send_opt(telnet
, o_we_sga
.send
, o_we_sga
.option
);
277 if (telnet
->opt_states
[o_they_sga
.index
] == INACTIVE
) {
278 telnet
->opt_states
[o_they_sga
.index
] = REQUESTED
;
279 send_opt(telnet
, o_they_sga
.send
, o_they_sga
.option
);
281 telnet
->activated
= TRUE
;
285 static void activate_option(Telnet telnet
, const struct Opt
*o
)
287 if (o
->send
== WILL
&& o
->option
== TELOPT_NAWS
)
288 telnet_size(telnet
, telnet
->term_width
, telnet
->term_height
);
289 if (o
->send
== WILL
&&
290 (o
->option
== TELOPT_NEW_ENVIRON
||
291 o
->option
== TELOPT_OLD_ENVIRON
)) {
293 * We may only have one kind of ENVIRON going at a time.
294 * This is a hack, but who cares.
296 deactivate_option(telnet
, o
->option
==
297 TELOPT_NEW_ENVIRON ?
&o_oenv
: &o_nenv
);
299 option_side_effects(telnet
, o
, 1);
302 static void refused_option(Telnet telnet
, const struct Opt
*o
)
304 if (o
->send
== WILL
&& o
->option
== TELOPT_NEW_ENVIRON
&&
305 telnet
->opt_states
[o_oenv
.index
] == INACTIVE
) {
306 send_opt(telnet
, WILL
, TELOPT_OLD_ENVIRON
);
307 telnet
->opt_states
[o_oenv
.index
] = REQUESTED
;
309 option_side_effects(telnet
, o
, 0);
312 static void proc_rec_opt(Telnet telnet
, int cmd
, int option
)
314 const struct Opt
*const *o
;
316 log_option(telnet
, "server", cmd
, option
);
317 for (o
= opts
; *o
; o
++) {
318 if ((*o
)->option
== option
&& (*o
)->ack
== cmd
) {
319 switch (telnet
->opt_states
[(*o
)->index
]) {
321 telnet
->opt_states
[(*o
)->index
] = ACTIVE
;
322 activate_option(telnet
, *o
);
327 telnet
->opt_states
[(*o
)->index
] = ACTIVE
;
328 send_opt(telnet
, (*o
)->send
, option
);
329 activate_option(telnet
, *o
);
331 case REALLY_INACTIVE
:
332 send_opt(telnet
, (*o
)->nsend
, option
);
336 } else if ((*o
)->option
== option
&& (*o
)->nak
== cmd
) {
337 switch (telnet
->opt_states
[(*o
)->index
]) {
339 telnet
->opt_states
[(*o
)->index
] = INACTIVE
;
340 refused_option(telnet
, *o
);
343 telnet
->opt_states
[(*o
)->index
] = INACTIVE
;
344 send_opt(telnet
, (*o
)->nsend
, option
);
345 option_side_effects(telnet
, *o
, 0);
348 case REALLY_INACTIVE
:
355 * If we reach here, the option was one we weren't prepared to
356 * cope with. If the request was positive (WILL or DO), we send
357 * a negative ack to indicate refusal. If the request was
358 * negative (WONT / DONT), we must do nothing.
360 if (cmd
== WILL
|| cmd
== DO
)
361 send_opt(telnet
, (cmd
== WILL ? DONT
: WONT
), option
);
364 static void process_subneg(Telnet telnet
)
366 unsigned char b
[2048], *p
, *q
;
370 switch (telnet
->sb_opt
) {
372 if (telnet
->sb_len
== 1 && telnet
->sb_buf
[0] == TELQUAL_SEND
) {
376 b
[2] = TELOPT_TSPEED
;
378 strcpy((char *)(b
+ 4), telnet
->cfg
.termspeed
);
379 n
= 4 + strlen(telnet
->cfg
.termspeed
);
382 telnet
->bufsize
= sk_write(telnet
->s
, (char *)b
, n
+ 2);
383 logevent(telnet
->frontend
, "server:\tSB TSPEED SEND");
384 logbuf
= dupprintf("client:\tSB TSPEED IS %s", telnet
->cfg
.termspeed
);
385 logevent(telnet
->frontend
, logbuf
);
388 logevent(telnet
->frontend
, "server:\tSB TSPEED <something weird>");
391 if (telnet
->sb_len
== 1 && telnet
->sb_buf
[0] == TELQUAL_SEND
) {
397 for (n
= 0; telnet
->cfg
.termtype
[n
]; n
++)
398 b
[n
+ 4] = (telnet
->cfg
.termtype
[n
] >= 'a'
399 && telnet
->cfg
.termtype
[n
] <=
400 'z' ? telnet
->cfg
.termtype
[n
] + 'A' -
401 'a' : telnet
->cfg
.termtype
[n
]);
404 telnet
->bufsize
= sk_write(telnet
->s
, (char *)b
, n
+ 6);
406 logevent(telnet
->frontend
, "server:\tSB TTYPE SEND");
407 logbuf
= dupprintf("client:\tSB TTYPE IS %s", b
+ 4);
408 logevent(telnet
->frontend
, logbuf
);
411 logevent(telnet
->frontend
, "server:\tSB TTYPE <something weird>\r\n");
413 case TELOPT_OLD_ENVIRON
:
414 case TELOPT_NEW_ENVIRON
:
416 q
= p
+ telnet
->sb_len
;
417 if (p
< q
&& *p
== TELQUAL_SEND
) {
420 logbuf
= dupprintf("server:\tSB %s SEND", telopt(telnet
->sb_opt
));
421 logevent(telnet
->frontend
, logbuf
);
423 if (telnet
->sb_opt
== TELOPT_OLD_ENVIRON
) {
424 if (telnet
->cfg
.rfc_environ
) {
432 * Try to guess the sense of VAR and VALUE.
438 } else if (*p
== BSD_VAR
) {
446 * With NEW_ENVIRON, the sense of VAR and VALUE
454 b
[2] = telnet
->sb_opt
;
457 e
= telnet
->cfg
.environmt
;
460 while (*e
&& *e
!= '\t')
470 char user
[sizeof(telnet
->cfg
.username
)];
471 (void) get_remote_username(&telnet
->cfg
, user
, sizeof(user
));
485 telnet
->bufsize
= sk_write(telnet
->s
, (char *)b
, n
);
486 logbuf
= dupprintf("client:\tSB %s IS %s%s%s%s",
487 telopt(telnet
->sb_opt
),
488 *user ?
"USER=" : "",
491 n
== 6 ?
"<nothing>" :
492 (*telnet
->cfg
.environmt ?
"<stuff>" : ""));
493 logevent(telnet
->frontend
, logbuf
);
501 static void do_telnet_read(Telnet telnet
, char *buf
, int len
)
504 int outbuflen
= 0, outbufsize
= 0;
506 #define ADDTOBUF(c) do { \
507 if (outbuflen >= outbufsize) { \
508 outbufsize = outbuflen + 256; \
509 outbuf = sresize(outbuf, outbufsize, char); \
511 outbuf[outbuflen++] = (c); \
515 int c
= (unsigned char) *buf
++;
517 switch (telnet
->state
) {
520 if (c
== NUL
&& telnet
->state
== SEENCR
)
521 telnet
->state
= TOP_LEVEL
;
523 telnet
->state
= SEENIAC
;
525 if (!telnet
->in_synch
)
529 /* I can't get the F***ing winsock to insert the urgent IAC
530 * into the right position! Even with SO_OOBINLINE it gives
531 * it to recv too soon. And of course the DM byte (that
532 * arrives in the same packet!) appears several K later!!
534 * Oh well, we do get the DM in the right place so I'll
535 * just stop hiding on the next 0xf2 and hope for the best.
538 telnet
->in_synch
= 0;
540 if (c
== CR
&& telnet
->opt_states
[o_they_bin
.index
] != ACTIVE
)
541 telnet
->state
= SEENCR
;
543 telnet
->state
= TOP_LEVEL
;
548 telnet
->state
= SEENDO
;
550 telnet
->state
= SEENDONT
;
552 telnet
->state
= SEENWILL
;
554 telnet
->state
= SEENWONT
;
556 telnet
->state
= SEENSB
;
558 telnet
->in_synch
= 0;
559 telnet
->state
= TOP_LEVEL
;
561 /* ignore everything else; print it if it's IAC */
565 telnet
->state
= TOP_LEVEL
;
569 proc_rec_opt(telnet
, WILL
, c
);
570 telnet
->state
= TOP_LEVEL
;
573 proc_rec_opt(telnet
, WONT
, c
);
574 telnet
->state
= TOP_LEVEL
;
577 proc_rec_opt(telnet
, DO
, c
);
578 telnet
->state
= TOP_LEVEL
;
581 proc_rec_opt(telnet
, DONT
, c
);
582 telnet
->state
= TOP_LEVEL
;
587 telnet
->state
= SUBNEGOT
;
591 telnet
->state
= SUBNEG_IAC
;
594 if (telnet
->sb_len
>= telnet
->sb_size
) {
595 telnet
->sb_size
+= SB_DELTA
;
596 telnet
->sb_buf
= sresize(telnet
->sb_buf
, telnet
->sb_size
,
599 telnet
->sb_buf
[telnet
->sb_len
++] = c
;
600 telnet
->state
= SUBNEGOT
; /* in case we came here by goto */
605 goto subneg_addchar
; /* yes, it's a hack, I know, but... */
607 process_subneg(telnet
);
608 telnet
->state
= TOP_LEVEL
;
615 c_write(telnet
, outbuf
, outbuflen
);
619 static void telnet_log(Plug plug
, int type
, SockAddr addr
, int port
,
620 const char *error_msg
, int error_code
)
622 Telnet telnet
= (Telnet
) plug
;
623 char addrbuf
[256], *msg
;
625 sk_getaddr(addr
, addrbuf
, lenof(addrbuf
));
628 msg
= dupprintf("Connecting to %s port %d", addrbuf
, port
);
630 msg
= dupprintf("Failed to connect to %s: %s", addrbuf
, error_msg
);
632 logevent(telnet
->frontend
, msg
);
635 static int telnet_closing(Plug plug
, const char *error_msg
, int error_code
,
638 Telnet telnet
= (Telnet
) plug
;
643 notify_remote_exit(telnet
->frontend
);
646 logevent(telnet
->frontend
, error_msg
);
647 connection_fatal(telnet
->frontend
, "%s", error_msg
);
649 /* Otherwise, the remote side closed the connection normally. */
653 static int telnet_receive(Plug plug
, int urgent
, char *data
, int len
)
655 Telnet telnet
= (Telnet
) plug
;
657 telnet
->in_synch
= TRUE
;
658 do_telnet_read(telnet
, data
, len
);
662 static void telnet_sent(Plug plug
, int bufsize
)
664 Telnet telnet
= (Telnet
) plug
;
665 telnet
->bufsize
= bufsize
;
669 * Called to set up the Telnet connection.
671 * Returns an error message, or NULL on success.
673 * Also places the canonical host name into `realhost'. It must be
674 * freed by the caller.
676 static const char *telnet_init(void *frontend_handle
, void **backend_handle
,
678 char *host
, int port
, char **realhost
,
679 int nodelay
, int keepalive
)
681 static const struct plug_function_table fn_table
= {
691 telnet
= snew(struct telnet_tag
);
692 telnet
->fn
= &fn_table
;
693 telnet
->cfg
= *cfg
; /* STRUCTURE COPY */
695 telnet
->echoing
= TRUE
;
696 telnet
->editing
= TRUE
;
697 telnet
->activated
= FALSE
;
698 telnet
->sb_buf
= NULL
;
700 telnet
->frontend
= frontend_handle
;
701 telnet
->term_width
= telnet
->cfg
.width
;
702 telnet
->term_height
= telnet
->cfg
.height
;
703 telnet
->state
= TOP_LEVEL
;
704 telnet
->ldisc
= NULL
;
705 telnet
->pinger
= NULL
;
706 *backend_handle
= telnet
;
713 buf
= dupprintf("Looking up host \"%s\"%s", host
,
714 (cfg
->addressfamily
== ADDRTYPE_IPV4 ?
" (IPv4)" :
715 (cfg
->addressfamily
== ADDRTYPE_IPV6 ?
" (IPv6)" :
717 logevent(telnet
->frontend
, buf
);
720 addr
= name_lookup(host
, port
, realhost
, &telnet
->cfg
, cfg
->addressfamily
);
721 if ((err
= sk_addr_error(addr
)) != NULL
) {
727 port
= 23; /* default telnet port */
732 telnet
->s
= new_connection(addr
, *realhost
, port
, 0, 1,
733 nodelay
, keepalive
, (Plug
) telnet
, &telnet
->cfg
);
734 if ((err
= sk_socket_error(telnet
->s
)) != NULL
)
737 telnet
->pinger
= pinger_new(&telnet
->cfg
, &telnet_backend
, telnet
);
740 * Initialise option states.
742 if (telnet
->cfg
.passive_telnet
) {
743 const struct Opt
*const *o
;
745 for (o
= opts
; *o
; o
++)
746 telnet
->opt_states
[(*o
)->index
] = INACTIVE
;
748 const struct Opt
*const *o
;
750 for (o
= opts
; *o
; o
++) {
751 telnet
->opt_states
[(*o
)->index
] = (*o
)->initial_state
;
752 if (telnet
->opt_states
[(*o
)->index
] == REQUESTED
)
753 send_opt(telnet
, (*o
)->send
, (*o
)->option
);
755 telnet
->activated
= TRUE
;
759 * Set up SYNCH state.
761 telnet
->in_synch
= FALSE
;
764 * We can send special commands from the start.
766 update_specials_menu(telnet
->frontend
);
769 * loghost overrides realhost, if specified.
771 if (*telnet
->cfg
.loghost
) {
775 *realhost
= dupstr(telnet
->cfg
.loghost
);
776 colon
= strrchr(*realhost
, ':');
779 * FIXME: if we ever update this aspect of ssh.c for
780 * IPv6 literal management, this should change in line
790 static void telnet_free(void *handle
)
792 Telnet telnet
= (Telnet
) handle
;
794 sfree(telnet
->sb_buf
);
798 pinger_free(telnet
->pinger
);
802 * Reconfigure the Telnet backend. There's no immediate action
803 * necessary, in this backend: we just save the fresh config for
804 * any subsequent negotiations.
806 static void telnet_reconfig(void *handle
, Config
*cfg
)
808 Telnet telnet
= (Telnet
) handle
;
809 pinger_reconfig(telnet
->pinger
, &telnet
->cfg
, cfg
);
810 telnet
->cfg
= *cfg
; /* STRUCTURE COPY */
814 * Called to send data down the Telnet connection.
816 static int telnet_send(void *handle
, char *buf
, int len
)
818 Telnet telnet
= (Telnet
) handle
;
819 unsigned char *p
, *end
;
820 static const unsigned char iac
[2] = { IAC
, IAC
};
821 static const unsigned char cr
[2] = { CR
, NUL
};
823 static const unsigned char nl
[2] = { CR
, LF
};
826 if (telnet
->s
== NULL
)
829 p
= (unsigned char *)buf
;
830 end
= (unsigned char *)(buf
+ len
);
832 unsigned char *q
= p
;
834 while (p
< end
&& iswritable(*p
))
836 telnet
->bufsize
= sk_write(telnet
->s
, (char *)q
, p
- q
);
838 while (p
< end
&& !iswritable(*p
)) {
840 sk_write(telnet
->s
, (char *)(*p
== IAC ? iac
: cr
), 2);
845 return telnet
->bufsize
;
849 * Called to query the current socket sendability status.
851 static int telnet_sendbuffer(void *handle
)
853 Telnet telnet
= (Telnet
) handle
;
854 return telnet
->bufsize
;
858 * Called to set the size of the window from Telnet's POV.
860 static void telnet_size(void *handle
, int width
, int height
)
862 Telnet telnet
= (Telnet
) handle
;
867 telnet
->term_width
= width
;
868 telnet
->term_height
= height
;
870 if (telnet
->s
== NULL
|| telnet
->opt_states
[o_naws
.index
] != ACTIVE
)
875 b
[n
++] = TELOPT_NAWS
;
876 b
[n
++] = telnet
->term_width
>> 8;
877 if (b
[n
-1] == IAC
) b
[n
++] = IAC
; /* duplicate any IAC byte occurs */
878 b
[n
++] = telnet
->term_width
& 0xFF;
879 if (b
[n
-1] == IAC
) b
[n
++] = IAC
; /* duplicate any IAC byte occurs */
880 b
[n
++] = telnet
->term_height
>> 8;
881 if (b
[n
-1] == IAC
) b
[n
++] = IAC
; /* duplicate any IAC byte occurs */
882 b
[n
++] = telnet
->term_height
& 0xFF;
883 if (b
[n
-1] == IAC
) b
[n
++] = IAC
; /* duplicate any IAC byte occurs */
886 telnet
->bufsize
= sk_write(telnet
->s
, (char *)b
, n
);
887 logbuf
= dupprintf("client:\tSB NAWS %d,%d",
888 telnet
->term_width
, telnet
->term_height
);
889 logevent(telnet
->frontend
, logbuf
);
894 * Send Telnet special codes.
896 static void telnet_special(void *handle
, Telnet_Special code
)
898 Telnet telnet
= (Telnet
) handle
;
901 if (telnet
->s
== NULL
)
908 telnet
->bufsize
= sk_write(telnet
->s
, (char *)b
, 2);
912 telnet
->bufsize
= sk_write(telnet
->s
, (char *)b
, 2);
916 telnet
->bufsize
= sk_write(telnet
->s
, (char *)b
, 2);
920 telnet
->bufsize
= sk_write(telnet
->s
, (char *)b
, 2);
924 telnet
->bufsize
= sk_write(telnet
->s
, (char *)b
, 2);
928 telnet
->bufsize
= sk_write(telnet
->s
, (char *)b
, 2);
932 telnet
->bufsize
= sk_write(telnet
->s
, (char *)b
, 2);
936 telnet
->bufsize
= sk_write(telnet
->s
, (char *)b
, 2);
940 telnet
->bufsize
= sk_write(telnet
->s
, (char *)b
, 2);
944 telnet
->bufsize
= sk_write(telnet
->s
, (char *)b
, 2);
948 telnet
->bufsize
= sk_write(telnet
->s
, (char *)b
, 2);
952 telnet
->bufsize
= sk_write(telnet
->s
, (char *)b
, 2);
955 /* In BINARY mode, CR-LF becomes just CR -
956 * and without the NUL suffix too. */
957 if (telnet
->opt_states
[o_we_bin
.index
] == ACTIVE
)
958 telnet
->bufsize
= sk_write(telnet
->s
, "\r", 1);
960 telnet
->bufsize
= sk_write(telnet
->s
, "\r\n", 2);
964 telnet
->bufsize
= sk_write(telnet
->s
, (char *)b
, 1);
965 telnet
->bufsize
= sk_write_oob(telnet
->s
, (char *)(b
+ 1), 1);
968 if (telnet
->opt_states
[o_echo
.index
] == INACTIVE
||
969 telnet
->opt_states
[o_echo
.index
] == REALLY_INACTIVE
) {
970 telnet
->opt_states
[o_echo
.index
] = REQUESTED
;
971 send_opt(telnet
, o_echo
.send
, o_echo
.option
);
975 if (telnet
->opt_states
[o_echo
.index
] == ACTIVE
) {
976 telnet
->opt_states
[o_echo
.index
] = REQUESTED
;
977 send_opt(telnet
, o_echo
.nsend
, o_echo
.option
);
981 if (telnet
->opt_states
[o_they_sga
.index
] == ACTIVE
) {
983 telnet
->bufsize
= sk_write(telnet
->s
, (char *)b
, 2);
987 break; /* never heard of it */
991 static const struct telnet_special
*telnet_get_specials(void *handle
)
993 static const struct telnet_special specials
[] = {
994 {"Are You There", TS_AYT
},
997 {"Erase Character", TS_EC
},
998 {"Erase Line", TS_EL
},
1000 {"No Operation", TS_NOP
},
1002 {"Abort Process", TS_ABORT
},
1003 {"Abort Output", TS_AO
},
1004 {"Interrupt Process", TS_IP
},
1005 {"Suspend Process", TS_SUSP
},
1007 {"End Of Record", TS_EOR
},
1008 {"End Of File", TS_EOF
},
1014 static int telnet_connected(void *handle
)
1016 Telnet telnet
= (Telnet
) handle
;
1017 return telnet
->s
!= NULL
;
1020 static int telnet_sendok(void *handle
)
1022 /* Telnet telnet = (Telnet) handle; */
1026 static void telnet_unthrottle(void *handle
, int backlog
)
1028 Telnet telnet
= (Telnet
) handle
;
1029 sk_set_frozen(telnet
->s
, backlog
> TELNET_MAX_BACKLOG
);
1032 static int telnet_ldisc(void *handle
, int option
)
1034 Telnet telnet
= (Telnet
) handle
;
1035 if (option
== LD_ECHO
)
1036 return telnet
->echoing
;
1037 if (option
== LD_EDIT
)
1038 return telnet
->editing
;
1042 static void telnet_provide_ldisc(void *handle
, void *ldisc
)
1044 Telnet telnet
= (Telnet
) handle
;
1045 telnet
->ldisc
= ldisc
;
1048 static void telnet_provide_logctx(void *handle
, void *logctx
)
1050 /* This is a stub. */
1053 static int telnet_exitcode(void *handle
)
1055 Telnet telnet
= (Telnet
) handle
;
1056 if (telnet
->s
!= NULL
)
1057 return -1; /* still connected */
1059 /* Telnet doesn't transmit exit codes back to the client */
1064 * cfg_info for Telnet does nothing at all.
1066 static int telnet_cfg_info(void *handle
)
1071 Backend telnet_backend
= {
1079 telnet_get_specials
,
1084 telnet_provide_ldisc
,
1085 telnet_provide_logctx
,