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uint64_decimal() incorrectly output 0 as "" instead of "0". This only affected
[u/mdw/putty] / telnet.c
CommitLineData
374330e2 1#include <stdio.h>
2#include <stdlib.h>
374330e2 3
4#include "putty.h"
5
6#ifndef FALSE
7#define FALSE 0
8#endif
9#ifndef TRUE
10#define TRUE 1
11#endif
12
32874aea 13#define IAC 255 /* interpret as command: */
14#define DONT 254 /* you are not to use option */
15#define DO 253 /* please, you use option */
16#define WONT 252 /* I won't use option */
17#define WILL 251 /* I will use option */
18#define SB 250 /* interpret as subnegotiation */
19#define SE 240 /* end sub negotiation */
20
21#define GA 249 /* you may reverse the line */
22#define EL 248 /* erase the current line */
23#define EC 247 /* erase the current character */
24#define AYT 246 /* are you there */
25#define AO 245 /* abort output--but let prog finish */
26#define IP 244 /* interrupt process--permanently */
27#define BREAK 243 /* break */
28#define DM 242 /* data mark--for connect. cleaning */
29#define NOP 241 /* nop */
30#define EOR 239 /* end of record (transparent mode) */
31#define ABORT 238 /* Abort process */
32#define SUSP 237 /* Suspend process */
33#define xEOF 236 /* End of file: EOF is already used... */
34
35#define TELOPT_BINARY 0 /* 8-bit data path */
36#define TELOPT_ECHO 1 /* echo */
37#define TELOPT_RCP 2 /* prepare to reconnect */
38#define TELOPT_SGA 3 /* suppress go ahead */
39#define TELOPT_NAMS 4 /* approximate message size */
40#define TELOPT_STATUS 5 /* give status */
41#define TELOPT_TM 6 /* timing mark */
42#define TELOPT_RCTE 7 /* remote controlled transmission and echo */
43#define TELOPT_NAOL 8 /* negotiate about output line width */
44#define TELOPT_NAOP 9 /* negotiate about output page size */
45#define TELOPT_NAOCRD 10 /* negotiate about CR disposition */
46#define TELOPT_NAOHTS 11 /* negotiate about horizontal tabstops */
47#define TELOPT_NAOHTD 12 /* negotiate about horizontal tab disposition */
48#define TELOPT_NAOFFD 13 /* negotiate about formfeed disposition */
49#define TELOPT_NAOVTS 14 /* negotiate about vertical tab stops */
50#define TELOPT_NAOVTD 15 /* negotiate about vertical tab disposition */
51#define TELOPT_NAOLFD 16 /* negotiate about output LF disposition */
52#define TELOPT_XASCII 17 /* extended ascic character set */
53#define TELOPT_LOGOUT 18 /* force logout */
54#define TELOPT_BM 19 /* byte macro */
55#define TELOPT_DET 20 /* data entry terminal */
56#define TELOPT_SUPDUP 21 /* supdup protocol */
57#define TELOPT_SUPDUPOUTPUT 22 /* supdup output */
58#define TELOPT_SNDLOC 23 /* send location */
59#define TELOPT_TTYPE 24 /* terminal type */
60#define TELOPT_EOR 25 /* end or record */
61#define TELOPT_TUID 26 /* TACACS user identification */
62#define TELOPT_OUTMRK 27 /* output marking */
63#define TELOPT_TTYLOC 28 /* terminal location number */
64#define TELOPT_3270REGIME 29 /* 3270 regime */
65#define TELOPT_X3PAD 30 /* X.3 PAD */
66#define TELOPT_NAWS 31 /* window size */
67#define TELOPT_TSPEED 32 /* terminal speed */
68#define TELOPT_LFLOW 33 /* remote flow control */
69#define TELOPT_LINEMODE 34 /* Linemode option */
70#define TELOPT_XDISPLOC 35 /* X Display Location */
71#define TELOPT_OLD_ENVIRON 36 /* Old - Environment variables */
72#define TELOPT_AUTHENTICATION 37 /* Authenticate */
73#define TELOPT_ENCRYPT 38 /* Encryption option */
74#define TELOPT_NEW_ENVIRON 39 /* New - Environment variables */
347e5401 75#define TELOPT_TN3270E 40 /* TN3270 enhancements */
76#define TELOPT_XAUTH 41
77#define TELOPT_CHARSET 42 /* Character set */
78#define TELOPT_RSP 43 /* Remote serial port */
79#define TELOPT_COM_PORT_OPTION 44 /* Com port control */
80#define TELOPT_SLE 45 /* Suppress local echo */
81#define TELOPT_STARTTLS 46 /* Start TLS */
82#define TELOPT_KERMIT 47 /* Automatic Kermit file transfer */
83#define TELOPT_SEND_URL 48
84#define TELOPT_FORWARD_X 49
85#define TELOPT_PRAGMA_LOGON 138
86#define TELOPT_SSPI_LOGON 139
87#define TELOPT_PRAGMA_HEARTBEAT 140
32874aea 88#define TELOPT_EXOPL 255 /* extended-options-list */
89
90#define TELQUAL_IS 0 /* option is... */
91#define TELQUAL_SEND 1 /* send option */
92#define TELQUAL_INFO 2 /* ENVIRON: informational version of IS */
374330e2 93#define BSD_VAR 1
94#define BSD_VALUE 0
95#define RFC_VAR 0
96#define RFC_VALUE 1
97
98#define CR 13
99#define LF 10
100#define NUL 0
101
656fa244 102#define iswritable(x) \
103 ( (x) != IAC && \
104 (telnet->opt_states[o_we_bin.index] == ACTIVE || (x) != CR))
374330e2 105
32874aea 106static char *telopt(int opt)
107{
374330e2 108#define i(x) if (opt == TELOPT_ ## x) return #x;
32874aea 109 i(BINARY);
110 i(ECHO);
111 i(RCP);
112 i(SGA);
113 i(NAMS);
114 i(STATUS);
115 i(TM);
116 i(RCTE);
117 i(NAOL);
118 i(NAOP);
119 i(NAOCRD);
120 i(NAOHTS);
121 i(NAOHTD);
122 i(NAOFFD);
123 i(NAOVTS);
124 i(NAOVTD);
125 i(NAOLFD);
126 i(XASCII);
127 i(LOGOUT);
128 i(BM);
129 i(DET);
130 i(SUPDUP);
131 i(SUPDUPOUTPUT);
132 i(SNDLOC);
133 i(TTYPE);
134 i(EOR);
135 i(TUID);
136 i(OUTMRK);
137 i(TTYLOC);
138 i(X3PAD);
139 i(NAWS);
140 i(TSPEED);
141 i(LFLOW);
142 i(LINEMODE);
143 i(XDISPLOC);
144 i(OLD_ENVIRON);
145 i(AUTHENTICATION);
146 i(ENCRYPT);
147 i(NEW_ENVIRON);
347e5401 148 i(TN3270E);
149 i(XAUTH);
150 i(CHARSET);
151 i(RSP);
152 i(COM_PORT_OPTION);
153 i(SLE);
154 i(STARTTLS);
155 i(KERMIT);
156 i(SEND_URL);
157 i(FORWARD_X);
158 i(PRAGMA_LOGON);
159 i(SSPI_LOGON);
160 i(PRAGMA_HEARTBEAT);
32874aea 161 i(EXOPL);
374330e2 162#undef i
163 return "<unknown>";
164}
165
51470298 166static void telnet_size(void *handle, int width, int height);
374330e2 167
168struct Opt {
169 int send; /* what we initially send */
170 int nsend; /* -ve send if requested to stop it */
171 int ack, nak; /* +ve and -ve acknowledgements */
172 int option; /* the option code */
51470298 173 int index; /* index into telnet->opt_states[] */
374330e2 174 enum {
175 REQUESTED, ACTIVE, INACTIVE, REALLY_INACTIVE
51470298 176 } initial_state;
177};
178
179enum {
180 OPTINDEX_NAWS,
181 OPTINDEX_TSPEED,
182 OPTINDEX_TTYPE,
183 OPTINDEX_OENV,
184 OPTINDEX_NENV,
185 OPTINDEX_ECHO,
186 OPTINDEX_WE_SGA,
187 OPTINDEX_THEY_SGA,
656fa244 188 OPTINDEX_WE_BIN,
189 OPTINDEX_THEY_BIN,
51470298 190 NUM_OPTS
374330e2 191};
192
51470298 193static const struct Opt o_naws =
194 { WILL, WONT, DO, DONT, TELOPT_NAWS, OPTINDEX_NAWS, REQUESTED };
195static const struct Opt o_tspeed =
196 { WILL, WONT, DO, DONT, TELOPT_TSPEED, OPTINDEX_TSPEED, REQUESTED };
197static const struct Opt o_ttype =
198 { WILL, WONT, DO, DONT, TELOPT_TTYPE, OPTINDEX_TTYPE, REQUESTED };
199static const struct Opt o_oenv = { WILL, WONT, DO, DONT, TELOPT_OLD_ENVIRON,
200 OPTINDEX_OENV, INACTIVE
32874aea 201};
51470298 202static const struct Opt o_nenv = { WILL, WONT, DO, DONT, TELOPT_NEW_ENVIRON,
203 OPTINDEX_NENV, REQUESTED
32874aea 204};
51470298 205static const struct Opt o_echo =
206 { DO, DONT, WILL, WONT, TELOPT_ECHO, OPTINDEX_ECHO, REQUESTED };
207static const struct Opt o_we_sga =
208 { WILL, WONT, DO, DONT, TELOPT_SGA, OPTINDEX_WE_SGA, REQUESTED };
209static const struct Opt o_they_sga =
210 { DO, DONT, WILL, WONT, TELOPT_SGA, OPTINDEX_THEY_SGA, REQUESTED };
656fa244 211static const struct Opt o_we_bin =
212 { WILL, WONT, DO, DONT, TELOPT_BINARY, OPTINDEX_WE_BIN, INACTIVE };
213static const struct Opt o_they_bin =
214 { DO, DONT, WILL, WONT, TELOPT_BINARY, OPTINDEX_THEY_BIN, INACTIVE };
51470298 215
216static const struct Opt *const opts[] = {
374330e2 217 &o_naws, &o_tspeed, &o_ttype, &o_oenv, &o_nenv, &o_echo,
656fa244 218 &o_we_sga, &o_they_sga, &o_we_bin, &o_they_bin, NULL
374330e2 219};
220
51470298 221typedef struct telnet_tag {
222 const struct plug_function_table *fn;
223 /* the above field _must_ be first in the structure */
224
225 Socket s;
226
227 void *frontend;
b9d7bcad 228 void *ldisc;
51470298 229 int term_width, term_height;
230
231 int opt_states[NUM_OPTS];
232
233 int echoing, editing;
234 int activated;
235 int bufsize;
236 int in_synch;
237 int sb_opt, sb_len;
a1fd562d 238 unsigned char *sb_buf;
51470298 239 int sb_size;
240
241 enum {
242 TOP_LEVEL, SEENIAC, SEENWILL, SEENWONT, SEENDO, SEENDONT,
243 SEENSB, SUBNEGOT, SUBNEG_IAC, SEENCR
244 } state;
245
86916870 246 Config cfg;
51470298 247} *Telnet;
248
5471d09a 249#define TELNET_MAX_BACKLOG 4096
250
374330e2 251#define SB_DELTA 1024
252
51470298 253static void c_write1(Telnet telnet, int c)
32874aea 254{
5471d09a 255 int backlog;
32874aea 256 char cc = (char) c;
51470298 257 backlog = from_backend(telnet->frontend, 0, &cc, 1);
258 sk_set_frozen(telnet->s, backlog > TELNET_MAX_BACKLOG);
fe50e814 259}
260
a8327734 261static void log_option(Telnet telnet, char *sender, int cmd, int option)
32874aea 262{
57356d63 263 char *buf;
24d7f854 264 /*
265 * The strange-looking "<?""?>" below is there to avoid a
266 * trigraph - a double question mark followed by > maps to a
267 * closing brace character!
268 */
57356d63 269 buf = dupprintf("%s:\t%s %s", sender,
270 (cmd == WILL ? "WILL" : cmd == WONT ? "WONT" :
271 cmd == DO ? "DO" : cmd == DONT ? "DONT" : "<?""?>"),
272 telopt(option));
a8327734 273 logevent(telnet->frontend, buf);
57356d63 274 sfree(buf);
374330e2 275}
276
51470298 277static void send_opt(Telnet telnet, int cmd, int option)
32874aea 278{
374330e2 279 unsigned char b[3];
280
32874aea 281 b[0] = IAC;
282 b[1] = cmd;
283 b[2] = option;
a1fd562d 284 telnet->bufsize = sk_write(telnet->s, (char *)b, 3);
a8327734 285 log_option(telnet, "client", cmd, option);
374330e2 286}
287
51470298 288static void deactivate_option(Telnet telnet, const struct Opt *o)
32874aea 289{
51470298 290 if (telnet->opt_states[o->index] == REQUESTED ||
291 telnet->opt_states[o->index] == ACTIVE)
292 send_opt(telnet, o->nsend, o->option);
293 telnet->opt_states[o->index] = REALLY_INACTIVE;
374330e2 294}
295
708bbbbe 296/*
297 * Generate side effects of enabling or disabling an option.
298 */
51470298 299static void option_side_effects(Telnet telnet, const struct Opt *o, int enabled)
32874aea 300{
0965bee0 301 if (o->option == TELOPT_ECHO && o->send == DO)
51470298 302 telnet->echoing = !enabled;
b6c680d4 303 else if (o->option == TELOPT_SGA && o->send == DO)
51470298 304 telnet->editing = !enabled;
b9d7bcad 305 if (telnet->ldisc) /* cause ldisc to notice the change */
306 ldisc_send(telnet->ldisc, NULL, 0, 0);
8faa456c 307
308 /* Ensure we get the minimum options */
51470298 309 if (!telnet->activated) {
310 if (telnet->opt_states[o_echo.index] == INACTIVE) {
311 telnet->opt_states[o_echo.index] = REQUESTED;
312 send_opt(telnet, o_echo.send, o_echo.option);
8faa456c 313 }
51470298 314 if (telnet->opt_states[o_we_sga.index] == INACTIVE) {
315 telnet->opt_states[o_we_sga.index] = REQUESTED;
316 send_opt(telnet, o_we_sga.send, o_we_sga.option);
8faa456c 317 }
51470298 318 if (telnet->opt_states[o_they_sga.index] == INACTIVE) {
319 telnet->opt_states[o_they_sga.index] = REQUESTED;
320 send_opt(telnet, o_they_sga.send, o_they_sga.option);
8faa456c 321 }
51470298 322 telnet->activated = TRUE;
8faa456c 323 }
708bbbbe 324}
325
51470298 326static void activate_option(Telnet telnet, const struct Opt *o)
32874aea 327{
374330e2 328 if (o->send == WILL && o->option == TELOPT_NAWS)
51470298 329 telnet_size(telnet, telnet->term_width, telnet->term_height);
374330e2 330 if (o->send == WILL &&
331 (o->option == TELOPT_NEW_ENVIRON ||
332 o->option == TELOPT_OLD_ENVIRON)) {
333 /*
334 * We may only have one kind of ENVIRON going at a time.
335 * This is a hack, but who cares.
336 */
51470298 337 deactivate_option(telnet, o->option ==
32874aea 338 TELOPT_NEW_ENVIRON ? &o_oenv : &o_nenv);
374330e2 339 }
51470298 340 option_side_effects(telnet, o, 1);
374330e2 341}
342
51470298 343static void refused_option(Telnet telnet, const struct Opt *o)
32874aea 344{
374330e2 345 if (o->send == WILL && o->option == TELOPT_NEW_ENVIRON &&
51470298 346 telnet->opt_states[o_oenv.index] == INACTIVE) {
347 send_opt(telnet, WILL, TELOPT_OLD_ENVIRON);
348 telnet->opt_states[o_oenv.index] = REQUESTED;
374330e2 349 }
51470298 350 option_side_effects(telnet, o, 0);
374330e2 351}
352
51470298 353static void proc_rec_opt(Telnet telnet, int cmd, int option)
32874aea 354{
51470298 355 const struct Opt *const *o;
374330e2 356
a8327734 357 log_option(telnet, "server", cmd, option);
374330e2 358 for (o = opts; *o; o++) {
359 if ((*o)->option == option && (*o)->ack == cmd) {
51470298 360 switch (telnet->opt_states[(*o)->index]) {
374330e2 361 case REQUESTED:
51470298 362 telnet->opt_states[(*o)->index] = ACTIVE;
363 activate_option(telnet, *o);
374330e2 364 break;
365 case ACTIVE:
366 break;
367 case INACTIVE:
51470298 368 telnet->opt_states[(*o)->index] = ACTIVE;
369 send_opt(telnet, (*o)->send, option);
370 activate_option(telnet, *o);
374330e2 371 break;
372 case REALLY_INACTIVE:
51470298 373 send_opt(telnet, (*o)->nsend, option);
374330e2 374 break;
375 }
376 return;
377 } else if ((*o)->option == option && (*o)->nak == cmd) {
51470298 378 switch (telnet->opt_states[(*o)->index]) {
374330e2 379 case REQUESTED:
51470298 380 telnet->opt_states[(*o)->index] = INACTIVE;
381 refused_option(telnet, *o);
374330e2 382 break;
383 case ACTIVE:
51470298 384 telnet->opt_states[(*o)->index] = INACTIVE;
385 send_opt(telnet, (*o)->nsend, option);
386 option_side_effects(telnet, *o, 0);
374330e2 387 break;
388 case INACTIVE:
389 case REALLY_INACTIVE:
390 break;
391 }
392 return;
393 }
394 }
395 /*
396 * If we reach here, the option was one we weren't prepared to
397 * cope with. So send a negative ack.
398 */
51470298 399 send_opt(telnet, (cmd == WILL ? DONT : WONT), option);
374330e2 400}
401
51470298 402static void process_subneg(Telnet telnet)
32874aea 403{
374330e2 404 unsigned char b[2048], *p, *q;
405 int var, value, n;
406 char *e;
407
51470298 408 switch (telnet->sb_opt) {
374330e2 409 case TELOPT_TSPEED:
51470298 410 if (telnet->sb_len == 1 && telnet->sb_buf[0] == TELQUAL_SEND) {
57356d63 411 char *logbuf;
32874aea 412 b[0] = IAC;
413 b[1] = SB;
414 b[2] = TELOPT_TSPEED;
374330e2 415 b[3] = TELQUAL_IS;
86916870 416 strcpy((char *)(b + 4), telnet->cfg.termspeed);
417 n = 4 + strlen(telnet->cfg.termspeed);
32874aea 418 b[n] = IAC;
419 b[n + 1] = SE;
a1fd562d 420 telnet->bufsize = sk_write(telnet->s, (char *)b, n + 2);
a8327734 421 logevent(telnet->frontend, "server:\tSB TSPEED SEND");
86916870 422 logbuf = dupprintf("client:\tSB TSPEED IS %s", telnet->cfg.termspeed);
a8327734 423 logevent(telnet->frontend, logbuf);
57356d63 424 sfree(logbuf);
374330e2 425 } else
a8327734 426 logevent(telnet->frontend, "server:\tSB TSPEED <something weird>");
374330e2 427 break;
428 case TELOPT_TTYPE:
51470298 429 if (telnet->sb_len == 1 && telnet->sb_buf[0] == TELQUAL_SEND) {
57356d63 430 char *logbuf;
32874aea 431 b[0] = IAC;
432 b[1] = SB;
433 b[2] = TELOPT_TTYPE;
374330e2 434 b[3] = TELQUAL_IS;
86916870 435 for (n = 0; telnet->cfg.termtype[n]; n++)
436 b[n + 4] = (telnet->cfg.termtype[n] >= 'a'
437 && telnet->cfg.termtype[n] <=
438 'z' ? telnet->cfg.termtype[n] + 'A' -
439 'a' : telnet->cfg.termtype[n]);
32874aea 440 b[n + 4] = IAC;
441 b[n + 5] = SE;
a1fd562d 442 telnet->bufsize = sk_write(telnet->s, (char *)b, n + 6);
32874aea 443 b[n + 4] = 0;
a8327734 444 logevent(telnet->frontend, "server:\tSB TTYPE SEND");
57356d63 445 logbuf = dupprintf("client:\tSB TTYPE IS %s", b + 4);
a8327734 446 logevent(telnet->frontend, logbuf);
57356d63 447 sfree(logbuf);
374330e2 448 } else
a8327734 449 logevent(telnet->frontend, "server:\tSB TTYPE <something weird>\r\n");
374330e2 450 break;
451 case TELOPT_OLD_ENVIRON:
32874aea 452 case TELOPT_NEW_ENVIRON:
51470298 453 p = telnet->sb_buf;
454 q = p + telnet->sb_len;
374330e2 455 if (p < q && *p == TELQUAL_SEND) {
57356d63 456 char *logbuf;
374330e2 457 p++;
57356d63 458 logbuf = dupprintf("server:\tSB %s SEND", telopt(telnet->sb_opt));
a8327734 459 logevent(telnet->frontend, logbuf);
57356d63 460 sfree(logbuf);
51470298 461 if (telnet->sb_opt == TELOPT_OLD_ENVIRON) {
86916870 462 if (telnet->cfg.rfc_environ) {
374330e2 463 value = RFC_VALUE;
464 var = RFC_VAR;
465 } else {
466 value = BSD_VALUE;
467 var = BSD_VAR;
468 }
469 /*
470 * Try to guess the sense of VAR and VALUE.
471 */
472 while (p < q) {
473 if (*p == RFC_VAR) {
474 value = RFC_VALUE;
475 var = RFC_VAR;
476 } else if (*p == BSD_VAR) {
477 value = BSD_VALUE;
478 var = BSD_VAR;
479 }
480 p++;
481 }
482 } else {
483 /*
484 * With NEW_ENVIRON, the sense of VAR and VALUE
485 * isn't in doubt.
486 */
487 value = RFC_VALUE;
488 var = RFC_VAR;
489 }
32874aea 490 b[0] = IAC;
491 b[1] = SB;
51470298 492 b[2] = telnet->sb_opt;
374330e2 493 b[3] = TELQUAL_IS;
494 n = 4;
86916870 495 e = telnet->cfg.environmt;
374330e2 496 while (*e) {
497 b[n++] = var;
32874aea 498 while (*e && *e != '\t')
499 b[n++] = *e++;
500 if (*e == '\t')
501 e++;
374330e2 502 b[n++] = value;
32874aea 503 while (*e)
504 b[n++] = *e++;
374330e2 505 e++;
506 }
86916870 507 if (*telnet->cfg.username) {
32874aea 508 b[n++] = var;
509 b[n++] = 'U';
510 b[n++] = 'S';
511 b[n++] = 'E';
512 b[n++] = 'R';
513 b[n++] = value;
86916870 514 e = telnet->cfg.username;
32874aea 515 while (*e)
516 b[n++] = *e++;
374330e2 517 }
32874aea 518 b[n++] = IAC;
519 b[n++] = SE;
a1fd562d 520 telnet->bufsize = sk_write(telnet->s, (char *)b, n);
afaa639b 521 logbuf = dupprintf("client:\tSB %s IS %s%s%s%s",
522 telopt(telnet->sb_opt),
523 *telnet->cfg.username ? "USER=" : "",
524 telnet->cfg.username,
525 *telnet->cfg.username ? " " : "",
526 n == 6 ? "<nothing>" :
527 (*telnet->cfg.environmt ? "<stuff>" : ""));
a8327734 528 logevent(telnet->frontend, logbuf);
57356d63 529 sfree(logbuf);
374330e2 530 }
531 break;
532 }
533}
534
51470298 535static void do_telnet_read(Telnet telnet, char *buf, int len)
32874aea 536{
374330e2 537
538 while (len--) {
539 int c = (unsigned char) *buf++;
540
51470298 541 switch (telnet->state) {
887035a5 542 case TOP_LEVEL:
374330e2 543 case SEENCR:
51470298 544 if (c == NUL && telnet->state == SEENCR)
545 telnet->state = TOP_LEVEL;
374330e2 546 else if (c == IAC)
51470298 547 telnet->state = SEENIAC;
374330e2 548 else {
51470298 549 if (!telnet->in_synch)
550 c_write1(telnet, c);
2f938b83 551
552#if 1
553 /* I can't get the F***ing winsock to insert the urgent IAC
554 * into the right position! Even with SO_OOBINLINE it gives
555 * it to recv too soon. And of course the DM byte (that
556 * arrives in the same packet!) appears several K later!!
557 *
558 * Oh well, we do get the DM in the right place so I'll
559 * just stop hiding on the next 0xf2 and hope for the best.
560 */
32874aea 561 else if (c == DM)
51470298 562 telnet->in_synch = 0;
2f938b83 563#endif
656fa244 564 if (c == CR && telnet->opt_states[o_they_bin.index] != ACTIVE)
51470298 565 telnet->state = SEENCR;
374330e2 566 else
51470298 567 telnet->state = TOP_LEVEL;
374330e2 568 }
569 break;
570 case SEENIAC:
32874aea 571 if (c == DO)
51470298 572 telnet->state = SEENDO;
32874aea 573 else if (c == DONT)
51470298 574 telnet->state = SEENDONT;
32874aea 575 else if (c == WILL)
51470298 576 telnet->state = SEENWILL;
32874aea 577 else if (c == WONT)
51470298 578 telnet->state = SEENWONT;
32874aea 579 else if (c == SB)
51470298 580 telnet->state = SEENSB;
2f938b83 581 else if (c == DM) {
51470298 582 telnet->in_synch = 0;
583 telnet->state = TOP_LEVEL;
32874aea 584 } else {
ded38628 585 /* ignore everything else; print it if it's IAC */
586 if (c == IAC) {
51470298 587 c_write1(telnet, c);
ded38628 588 }
51470298 589 telnet->state = TOP_LEVEL;
300d41b0 590 }
374330e2 591 break;
592 case SEENWILL:
51470298 593 proc_rec_opt(telnet, WILL, c);
594 telnet->state = TOP_LEVEL;
374330e2 595 break;
596 case SEENWONT:
51470298 597 proc_rec_opt(telnet, WONT, c);
598 telnet->state = TOP_LEVEL;
374330e2 599 break;
600 case SEENDO:
51470298 601 proc_rec_opt(telnet, DO, c);
602 telnet->state = TOP_LEVEL;
374330e2 603 break;
604 case SEENDONT:
51470298 605 proc_rec_opt(telnet, DONT, c);
606 telnet->state = TOP_LEVEL;
374330e2 607 break;
608 case SEENSB:
51470298 609 telnet->sb_opt = c;
610 telnet->sb_len = 0;
611 telnet->state = SUBNEGOT;
374330e2 612 break;
613 case SUBNEGOT:
614 if (c == IAC)
51470298 615 telnet->state = SUBNEG_IAC;
374330e2 616 else {
32874aea 617 subneg_addchar:
51470298 618 if (telnet->sb_len >= telnet->sb_size) {
51470298 619 telnet->sb_size += SB_DELTA;
3d88e64d 620 telnet->sb_buf = sresize(telnet->sb_buf, telnet->sb_size,
621 unsigned char);
374330e2 622 }
3d88e64d 623 telnet->sb_buf[telnet->sb_len++] = c;
51470298 624 telnet->state = SUBNEGOT; /* in case we came here by goto */
374330e2 625 }
626 break;
627 case SUBNEG_IAC:
628 if (c != SE)
629 goto subneg_addchar; /* yes, it's a hack, I know, but... */
630 else {
51470298 631 process_subneg(telnet);
632 telnet->state = TOP_LEVEL;
374330e2 633 }
634 break;
635 }
636 }
637}
638
cbe2d68f 639static int telnet_closing(Plug plug, const char *error_msg, int error_code,
32874aea 640 int calling_back)
641{
51470298 642 Telnet telnet = (Telnet) plug;
643
644 if (telnet->s) {
645 sk_close(telnet->s);
646 telnet->s = NULL;
f3ab576e 647 }
7e78000d 648 if (error_msg) {
32874aea 649 /* A socket error has occurred. */
a8327734 650 logevent(telnet->frontend, error_msg);
971bcc0a 651 connection_fatal(telnet->frontend, "%s", error_msg);
32874aea 652 } /* Otherwise, the remote side closed the connection normally. */
7e78000d 653 return 0;
654}
655
32874aea 656static int telnet_receive(Plug plug, int urgent, char *data, int len)
657{
51470298 658 Telnet telnet = (Telnet) plug;
32874aea 659 if (urgent)
51470298 660 telnet->in_synch = TRUE;
661 do_telnet_read(telnet, data, len);
8df7a775 662 return 1;
663}
664
3ad9d396 665static void telnet_sent(Plug plug, int bufsize)
666{
51470298 667 Telnet telnet = (Telnet) plug;
668 telnet->bufsize = bufsize;
3ad9d396 669}
670
374330e2 671/*
8df7a775 672 * Called to set up the Telnet connection.
374330e2 673 *
674 * Returns an error message, or NULL on success.
675 *
6e1ebb76 676 * Also places the canonical host name into `realhost'. It must be
677 * freed by the caller.
374330e2 678 */
cbe2d68f 679static const char *telnet_init(void *frontend_handle, void **backend_handle,
680 Config *cfg,
681 char *host, int port, char **realhost,
79bf227b 682 int nodelay, int keepalive)
32874aea 683{
51470298 684 static const struct plug_function_table fn_table = {
7e78000d 685 telnet_closing,
3ad9d396 686 telnet_receive,
687 telnet_sent
51470298 688 };
8df7a775 689 SockAddr addr;
cbe2d68f 690 const char *err;
51470298 691 Telnet telnet;
692
3d88e64d 693 telnet = snew(struct telnet_tag);
51470298 694 telnet->fn = &fn_table;
86916870 695 telnet->cfg = *cfg; /* STRUCTURE COPY */
51470298 696 telnet->s = NULL;
697 telnet->echoing = TRUE;
698 telnet->editing = TRUE;
699 telnet->activated = FALSE;
700 telnet->sb_buf = NULL;
701 telnet->sb_size = 0;
702 telnet->frontend = frontend_handle;
86916870 703 telnet->term_width = telnet->cfg.width;
704 telnet->term_height = telnet->cfg.height;
51470298 705 telnet->state = TOP_LEVEL;
cc31ab78 706 telnet->ldisc = NULL;
51470298 707 *backend_handle = telnet;
887035a5 708
374330e2 709 /*
710 * Try to find host.
711 */
3ad9d396 712 {
57356d63 713 char *buf;
714 buf = dupprintf("Looking up host \"%s\"", host);
a8327734 715 logevent(telnet->frontend, buf);
57356d63 716 sfree(buf);
3ad9d396 717 }
e8fa8f62 718 addr = name_lookup(host, port, realhost, &telnet->cfg);
f85e6f6e 719 if ((err = sk_addr_error(addr)) != NULL) {
720 sk_addr_free(addr);
8df7a775 721 return err;
f85e6f6e 722 }
374330e2 723
724 if (port < 0)
725 port = 23; /* default telnet port */
726
727 /*
728 * Open socket.
729 */
3ad9d396 730 {
57356d63 731 char *buf, addrbuf[100];
3ad9d396 732 sk_getaddr(addr, addrbuf, 100);
57356d63 733 buf = dupprintf("Connecting to %s port %d", addrbuf, port);
a8327734 734 logevent(telnet->frontend, buf);
57356d63 735 sfree(buf);
3ad9d396 736 }
51470298 737 telnet->s = new_connection(addr, *realhost, port, 0, 1,
79bf227b 738 nodelay, keepalive, (Plug) telnet, &telnet->cfg);
a1fd562d 739 if ((err = sk_socket_error(telnet->s)) != NULL)
8df7a775 740 return err;
374330e2 741
374330e2 742 /*
743 * Initialise option states.
744 */
86916870 745 if (telnet->cfg.passive_telnet) {
51470298 746 const struct Opt *const *o;
8faa456c 747
748 for (o = opts; *o; o++)
51470298 749 telnet->opt_states[(*o)->index] = INACTIVE;
8faa456c 750 } else {
51470298 751 const struct Opt *const *o;
374330e2 752
51470298 753 for (o = opts; *o; o++) {
754 telnet->opt_states[(*o)->index] = (*o)->initial_state;
755 if (telnet->opt_states[(*o)->index] == REQUESTED)
756 send_opt(telnet, (*o)->send, (*o)->option);
757 }
758 telnet->activated = TRUE;
374330e2 759 }
760
374330e2 761 /*
762 * Set up SYNCH state.
763 */
51470298 764 telnet->in_synch = FALSE;
6f34e365 765
533b1743 766 /*
767 * We can send special commands from the start.
768 */
769 update_specials_menu(telnet->frontend);
770
374330e2 771 return NULL;
772}
773
fabd1805 774static void telnet_free(void *handle)
775{
776 Telnet telnet = (Telnet) handle;
777
778 sfree(telnet->sb_buf);
779 if (telnet->s)
780 sk_close(telnet->s);
781 sfree(telnet);
782}
374330e2 783/*
86916870 784 * Reconfigure the Telnet backend. There's no immediate action
785 * necessary, in this backend: we just save the fresh config for
786 * any subsequent negotiations.
787 */
788static void telnet_reconfig(void *handle, Config *cfg)
789{
790 Telnet telnet = (Telnet) handle;
791 telnet->cfg = *cfg; /* STRUCTURE COPY */
792}
793
794/*
374330e2 795 * Called to send data down the Telnet connection.
796 */
51470298 797static int telnet_send(void *handle, char *buf, int len)
32874aea 798{
51470298 799 Telnet telnet = (Telnet) handle;
a1fd562d 800 unsigned char *p, *end;
c85623f9 801 static const unsigned char iac[2] = { IAC, IAC };
802 static const unsigned char cr[2] = { CR, NUL };
a5f3e637 803#if 0
c85623f9 804 static const unsigned char nl[2] = { CR, LF };
a5f3e637 805#endif
374330e2 806
51470298 807 if (telnet->s == NULL)
5471d09a 808 return 0;
374330e2 809
a1fd562d 810 p = (unsigned char *)buf;
811 end = (unsigned char *)(buf + len);
812 while (p < end) {
813 unsigned char *q = p;
374330e2 814
a1fd562d 815 while (p < end && iswritable(*p))
32874aea 816 p++;
a1fd562d 817 telnet->bufsize = sk_write(telnet->s, (char *)q, p - q);
374330e2 818
a1fd562d 819 while (p < end && !iswritable(*p)) {
51470298 820 telnet->bufsize =
a1fd562d 821 sk_write(telnet->s, (char *)(*p == IAC ? iac : cr), 2);
374330e2 822 p++;
823 }
824 }
5471d09a 825
51470298 826 return telnet->bufsize;
5471d09a 827}
828
829/*
830 * Called to query the current socket sendability status.
831 */
51470298 832static int telnet_sendbuffer(void *handle)
5471d09a 833{
51470298 834 Telnet telnet = (Telnet) handle;
835 return telnet->bufsize;
374330e2 836}
837
838/*
839 * Called to set the size of the window from Telnet's POV.
840 */
51470298 841static void telnet_size(void *handle, int width, int height)
32874aea 842{
51470298 843 Telnet telnet = (Telnet) handle;
ef41972c 844 unsigned char b[24];
845 int n;
57356d63 846 char *logbuf;
374330e2 847
51470298 848 telnet->term_width = width;
849 telnet->term_height = height;
f278d6f8 850
51470298 851 if (telnet->s == NULL || telnet->opt_states[o_naws.index] != ACTIVE)
374330e2 852 return;
ef41972c 853 n = 0;
854 b[n++] = IAC;
855 b[n++] = SB;
856 b[n++] = TELOPT_NAWS;
857 b[n++] = telnet->term_width >> 8;
858 if (b[n-1] == IAC) b[n++] = IAC; /* duplicate any IAC byte occurs */
859 b[n++] = telnet->term_width & 0xFF;
860 if (b[n-1] == IAC) b[n++] = IAC; /* duplicate any IAC byte occurs */
861 b[n++] = telnet->term_height >> 8;
862 if (b[n-1] == IAC) b[n++] = IAC; /* duplicate any IAC byte occurs */
863 b[n++] = telnet->term_height & 0xFF;
864 if (b[n-1] == IAC) b[n++] = IAC; /* duplicate any IAC byte occurs */
865 b[n++] = IAC;
866 b[n++] = SE;
a1fd562d 867 telnet->bufsize = sk_write(telnet->s, (char *)b, n);
57356d63 868 logbuf = dupprintf("client:\tSB NAWS %d,%d",
ef41972c 869 telnet->term_width, telnet->term_height);
a8327734 870 logevent(telnet->frontend, logbuf);
57356d63 871 sfree(logbuf);
374330e2 872}
873
874/*
875 * Send Telnet special codes.
876 */
51470298 877static void telnet_special(void *handle, Telnet_Special code)
32874aea 878{
51470298 879 Telnet telnet = (Telnet) handle;
374330e2 880 unsigned char b[2];
881
51470298 882 if (telnet->s == NULL)
374330e2 883 return;
884
885 b[0] = IAC;
886 switch (code) {
32874aea 887 case TS_AYT:
888 b[1] = AYT;
a1fd562d 889 telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
32874aea 890 break;
891 case TS_BRK:
892 b[1] = BREAK;
a1fd562d 893 telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
32874aea 894 break;
895 case TS_EC:
896 b[1] = EC;
a1fd562d 897 telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
32874aea 898 break;
899 case TS_EL:
900 b[1] = EL;
a1fd562d 901 telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
32874aea 902 break;
903 case TS_GA:
904 b[1] = GA;
a1fd562d 905 telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
32874aea 906 break;
907 case TS_NOP:
908 b[1] = NOP;
a1fd562d 909 telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
32874aea 910 break;
911 case TS_ABORT:
912 b[1] = ABORT;
a1fd562d 913 telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
32874aea 914 break;
915 case TS_AO:
916 b[1] = AO;
a1fd562d 917 telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
32874aea 918 break;
919 case TS_IP:
920 b[1] = IP;
a1fd562d 921 telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
32874aea 922 break;
923 case TS_SUSP:
924 b[1] = SUSP;
a1fd562d 925 telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
32874aea 926 break;
927 case TS_EOR:
928 b[1] = EOR;
a1fd562d 929 telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
32874aea 930 break;
931 case TS_EOF:
932 b[1] = xEOF;
a1fd562d 933 telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
32874aea 934 break;
a5f3e637 935 case TS_EOL:
6ee0cb6d 936 /* In BINARY mode, CR-LF becomes just CR -
937 * and without the NUL suffix too. */
656fa244 938 if (telnet->opt_states[o_we_bin.index] == ACTIVE)
6ee0cb6d 939 telnet->bufsize = sk_write(telnet->s, "\r", 1);
656fa244 940 else
941 telnet->bufsize = sk_write(telnet->s, "\r\n", 2);
a5f3e637 942 break;
374330e2 943 case TS_SYNCH:
32874aea 944 b[1] = DM;
a1fd562d 945 telnet->bufsize = sk_write(telnet->s, (char *)b, 1);
946 telnet->bufsize = sk_write_oob(telnet->s, (char *)(b + 1), 1);
32874aea 947 break;
684d367c 948 case TS_RECHO:
51470298 949 if (telnet->opt_states[o_echo.index] == INACTIVE ||
950 telnet->opt_states[o_echo.index] == REALLY_INACTIVE) {
951 telnet->opt_states[o_echo.index] = REQUESTED;
952 send_opt(telnet, o_echo.send, o_echo.option);
684d367c 953 }
954 break;
955 case TS_LECHO:
51470298 956 if (telnet->opt_states[o_echo.index] == ACTIVE) {
957 telnet->opt_states[o_echo.index] = REQUESTED;
958 send_opt(telnet, o_echo.nsend, o_echo.option);
684d367c 959 }
374330e2 960 break;
32874aea 961 case TS_PING:
51470298 962 if (telnet->opt_states[o_they_sga.index] == ACTIVE) {
32874aea 963 b[1] = NOP;
a1fd562d 964 telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
ec55b220 965 }
32874aea 966 break;
6f2d0cde 967 default:
968 break; /* never heard of it */
374330e2 969 }
970}
971
125105d1 972static const struct telnet_special *telnet_get_specials(void *handle)
973{
974 static const struct telnet_special specials[] = {
975 {"Are You There", TS_AYT},
976 {"Break", TS_BRK},
977 {"Synch", TS_SYNCH},
978 {"Erase Character", TS_EC},
979 {"Erase Line", TS_EL},
980 {"Go Ahead", TS_GA},
981 {"No Operation", TS_NOP},
6f2d0cde 982 {NULL, TS_SEP},
125105d1 983 {"Abort Process", TS_ABORT},
984 {"Abort Output", TS_AO},
985 {"Interrupt Process", TS_IP},
986 {"Suspend Process", TS_SUSP},
6f2d0cde 987 {NULL, TS_SEP},
125105d1 988 {"End Of Record", TS_EOR},
989 {"End Of File", TS_EOF},
6f2d0cde 990 {NULL, TS_EXITMENU}
125105d1 991 };
992 return specials;
993}
994
51470298 995static Socket telnet_socket(void *handle)
32874aea 996{
51470298 997 Telnet telnet = (Telnet) handle;
998 return telnet->s;
32874aea 999}
8ccc75b0 1000
51470298 1001static int telnet_sendok(void *handle)
32874aea 1002{
68a49acb 1003 /* Telnet telnet = (Telnet) handle; */
32874aea 1004 return 1;
1005}
4017be6d 1006
51470298 1007static void telnet_unthrottle(void *handle, int backlog)
5471d09a 1008{
51470298 1009 Telnet telnet = (Telnet) handle;
1010 sk_set_frozen(telnet->s, backlog > TELNET_MAX_BACKLOG);
5471d09a 1011}
1012
51470298 1013static int telnet_ldisc(void *handle, int option)
32874aea 1014{
51470298 1015 Telnet telnet = (Telnet) handle;
32874aea 1016 if (option == LD_ECHO)
51470298 1017 return telnet->echoing;
32874aea 1018 if (option == LD_EDIT)
51470298 1019 return telnet->editing;
0965bee0 1020 return FALSE;
1021}
1022
b9d7bcad 1023static void telnet_provide_ldisc(void *handle, void *ldisc)
1024{
1025 Telnet telnet = (Telnet) handle;
1026 telnet->ldisc = ldisc;
1027}
1028
a8327734 1029static void telnet_provide_logctx(void *handle, void *logctx)
1030{
1031 /* This is a stub. */
1032}
1033
51470298 1034static int telnet_exitcode(void *handle)
d8d6c7e5 1035{
0da1a790 1036 Telnet telnet = (Telnet) handle;
1037 if (telnet->s != NULL)
1038 return -1; /* still connected */
1039 else
1040 /* Telnet doesn't transmit exit codes back to the client */
1041 return 0;
d8d6c7e5 1042}
1043
374330e2 1044Backend telnet_backend = {
1045 telnet_init,
fabd1805 1046 telnet_free,
86916870 1047 telnet_reconfig,
374330e2 1048 telnet_send,
5471d09a 1049 telnet_sendbuffer,
374330e2 1050 telnet_size,
4017be6d 1051 telnet_special,
125105d1 1052 telnet_get_specials,
8ccc75b0 1053 telnet_socket,
d8d6c7e5 1054 telnet_exitcode,
97db3be4 1055 telnet_sendok,
0965bee0 1056 telnet_ldisc,
b9d7bcad 1057 telnet_provide_ldisc,
a8327734 1058 telnet_provide_logctx,
5471d09a 1059 telnet_unthrottle,
97db3be4 1060 23
374330e2 1061};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator