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Ooh. Actually, that vulnerability is further-reaching than I
[u/mdw/putty] / telnet.c
CommitLineData
374330e2 1#include <windows.h>
2#include <stdio.h>
3#include <stdlib.h>
4d331a77 4#ifndef AUTO_WINSOCK
5#ifdef WINSOCK_TWO
6#include <winsock2.h>
7#else
374330e2 8#include <winsock.h>
4d331a77 9#endif
10#endif
374330e2 11
12#include "putty.h"
13
14#ifndef FALSE
15#define FALSE 0
16#endif
17#ifndef TRUE
18#define TRUE 1
19#endif
20
21static SOCKET s = INVALID_SOCKET;
22
23#define IAC 255 /* interpret as command: */
24#define DONT 254 /* you are not to use option */
25#define DO 253 /* please, you use option */
26#define WONT 252 /* I won't use option */
27#define WILL 251 /* I will use option */
28#define SB 250 /* interpret as subnegotiation */
29#define SE 240 /* end sub negotiation */
30
31#define GA 249 /* you may reverse the line */
32#define EL 248 /* erase the current line */
33#define EC 247 /* erase the current character */
34#define AYT 246 /* are you there */
35#define AO 245 /* abort output--but let prog finish */
36#define IP 244 /* interrupt process--permanently */
37#define BREAK 243 /* break */
38#define DM 242 /* data mark--for connect. cleaning */
39#define NOP 241 /* nop */
40#define EOR 239 /* end of record (transparent mode) */
41#define ABORT 238 /* Abort process */
42#define SUSP 237 /* Suspend process */
43#define xEOF 236 /* End of file: EOF is already used... */
44
45#define TELOPT_BINARY 0 /* 8-bit data path */
46#define TELOPT_ECHO 1 /* echo */
47#define TELOPT_RCP 2 /* prepare to reconnect */
48#define TELOPT_SGA 3 /* suppress go ahead */
49#define TELOPT_NAMS 4 /* approximate message size */
50#define TELOPT_STATUS 5 /* give status */
51#define TELOPT_TM 6 /* timing mark */
52#define TELOPT_RCTE 7 /* remote controlled transmission and echo */
53#define TELOPT_NAOL 8 /* negotiate about output line width */
54#define TELOPT_NAOP 9 /* negotiate about output page size */
55#define TELOPT_NAOCRD 10 /* negotiate about CR disposition */
56#define TELOPT_NAOHTS 11 /* negotiate about horizontal tabstops */
57#define TELOPT_NAOHTD 12 /* negotiate about horizontal tab disposition */
58#define TELOPT_NAOFFD 13 /* negotiate about formfeed disposition */
59#define TELOPT_NAOVTS 14 /* negotiate about vertical tab stops */
60#define TELOPT_NAOVTD 15 /* negotiate about vertical tab disposition */
61#define TELOPT_NAOLFD 16 /* negotiate about output LF disposition */
62#define TELOPT_XASCII 17 /* extended ascic character set */
63#define TELOPT_LOGOUT 18 /* force logout */
64#define TELOPT_BM 19 /* byte macro */
65#define TELOPT_DET 20 /* data entry terminal */
66#define TELOPT_SUPDUP 21 /* supdup protocol */
67#define TELOPT_SUPDUPOUTPUT 22 /* supdup output */
68#define TELOPT_SNDLOC 23 /* send location */
69#define TELOPT_TTYPE 24 /* terminal type */
70#define TELOPT_EOR 25 /* end or record */
71#define TELOPT_TUID 26 /* TACACS user identification */
72#define TELOPT_OUTMRK 27 /* output marking */
73#define TELOPT_TTYLOC 28 /* terminal location number */
74#define TELOPT_3270REGIME 29 /* 3270 regime */
75#define TELOPT_X3PAD 30 /* X.3 PAD */
76#define TELOPT_NAWS 31 /* window size */
77#define TELOPT_TSPEED 32 /* terminal speed */
78#define TELOPT_LFLOW 33 /* remote flow control */
79#define TELOPT_LINEMODE 34 /* Linemode option */
80#define TELOPT_XDISPLOC 35 /* X Display Location */
81#define TELOPT_OLD_ENVIRON 36 /* Old - Environment variables */
82#define TELOPT_AUTHENTICATION 37/* Authenticate */
83#define TELOPT_ENCRYPT 38 /* Encryption option */
84#define TELOPT_NEW_ENVIRON 39 /* New - Environment variables */
85#define TELOPT_EXOPL 255 /* extended-options-list */
86
87#define TELQUAL_IS 0 /* option is... */
88#define TELQUAL_SEND 1 /* send option */
89#define TELQUAL_INFO 2 /* ENVIRON: informational version of IS */
90#define BSD_VAR 1
91#define BSD_VALUE 0
92#define RFC_VAR 0
93#define RFC_VALUE 1
94
95#define CR 13
96#define LF 10
97#define NUL 0
98
99#define iswritable(x) ( (x) != IAC && (x) != CR )
100
101static char *telopt(int opt) {
102#define i(x) if (opt == TELOPT_ ## x) return #x;
103 i(BINARY); i(ECHO); i(RCP); i(SGA); i(NAMS); i(STATUS); i(TM); i(RCTE);
104 i(NAOL); i(NAOP); i(NAOCRD); i(NAOHTS); i(NAOHTD); i(NAOFFD); i(NAOVTS);
105 i(NAOVTD); i(NAOLFD); i(XASCII); i(LOGOUT); i(BM); i(DET); i(SUPDUP);
106 i(SUPDUPOUTPUT); i(SNDLOC); i(TTYPE); i(EOR); i(TUID); i(OUTMRK);
107 i(TTYLOC); i(X3PAD); i(NAWS); i(TSPEED); i(LFLOW); i(LINEMODE);
108 i(XDISPLOC); i(OLD_ENVIRON); i(AUTHENTICATION); i(ENCRYPT);
109 i(NEW_ENVIRON); i(EXOPL);
110#undef i
111 return "<unknown>";
112}
113
114static void telnet_size(void);
115
116struct Opt {
117 int send; /* what we initially send */
118 int nsend; /* -ve send if requested to stop it */
119 int ack, nak; /* +ve and -ve acknowledgements */
120 int option; /* the option code */
121 enum {
122 REQUESTED, ACTIVE, INACTIVE, REALLY_INACTIVE
123 } state;
124};
125
126static struct Opt o_naws = {WILL, WONT, DO, DONT, TELOPT_NAWS, REQUESTED};
127static struct Opt o_tspeed = {WILL, WONT, DO, DONT, TELOPT_TSPEED, REQUESTED};
128static struct Opt o_ttype = {WILL, WONT, DO, DONT, TELOPT_TTYPE, REQUESTED};
129static struct Opt o_oenv = {WILL, WONT, DO, DONT, TELOPT_OLD_ENVIRON,
130 INACTIVE};
131static struct Opt o_nenv = {WILL, WONT, DO, DONT, TELOPT_NEW_ENVIRON,
132 REQUESTED};
133static struct Opt o_echo = {DO, DONT, WILL, WONT, TELOPT_ECHO, REQUESTED};
134static struct Opt o_we_sga = {WILL, WONT, DO, DONT, TELOPT_SGA, REQUESTED};
135static struct Opt o_they_sga = {DO, DONT, WILL, WONT, TELOPT_SGA, REQUESTED};
136
137static struct Opt *opts[] = {
138 &o_naws, &o_tspeed, &o_ttype, &o_oenv, &o_nenv, &o_echo,
139 &o_we_sga, &o_they_sga, NULL
140};
141
374330e2 142static int in_synch;
374330e2 143static int sb_opt, sb_len;
144static char *sb_buf = NULL;
145static int sb_size = 0;
146#define SB_DELTA 1024
147
148static void try_write (void) {
149 while (outbuf_head != outbuf_reap) {
150 int end = (outbuf_reap < outbuf_head ? outbuf_head : OUTBUF_SIZE);
151 int len = end - outbuf_reap;
152 int ret;
153
154 ret = send (s, outbuf+outbuf_reap, len, 0);
155 if (ret > 0)
156 outbuf_reap = (outbuf_reap + ret) & OUTBUF_MASK;
157 if (ret < len)
158 return;
159 }
160}
161
162static void s_write (void *buf, int len) {
163 unsigned char *p = buf;
164 while (len--) {
165 int new_head = (outbuf_head + 1) & OUTBUF_MASK;
166 if (new_head != outbuf_reap) {
167 outbuf[outbuf_head] = *p++;
168 outbuf_head = new_head;
169 }
170 }
171 try_write();
172}
173
fe50e814 174static void c_write1(int c) {
175 char cc = (char)c;
176 from_backend(0, &cc, 1);
177}
178
374330e2 179static void log_option (char *sender, int cmd, int option) {
180 char buf[50];
181 sprintf(buf, "%s:\t%s %s", sender,
182 (cmd == WILL ? "WILL" : cmd == WONT ? "WONT" :
183 cmd == DO ? "DO" : cmd == DONT ? "DONT" : "<??>"),
184 telopt(option));
c5e9c988 185 logevent(buf);
374330e2 186}
187
188static void send_opt (int cmd, int option) {
189 unsigned char b[3];
190
191 b[0] = IAC; b[1] = cmd; b[2] = option;
192 s_write (b, 3);
193 log_option("client", cmd, option);
194}
195
196static void deactivate_option (struct Opt *o) {
197 if (o->state == REQUESTED || o->state == ACTIVE)
198 send_opt (o->nsend, o->option);
199 o->state = REALLY_INACTIVE;
200}
201
202static void activate_option (struct Opt *o) {
203 if (o->send == WILL && o->option == TELOPT_NAWS)
204 telnet_size();
205 if (o->send == WILL &&
206 (o->option == TELOPT_NEW_ENVIRON ||
207 o->option == TELOPT_OLD_ENVIRON)) {
208 /*
209 * We may only have one kind of ENVIRON going at a time.
210 * This is a hack, but who cares.
211 */
212 deactivate_option (o->option==TELOPT_NEW_ENVIRON ? &o_oenv : &o_nenv);
213 }
2f938b83 214 if (o->option == TELOPT_ECHO && cfg.ldisc_term)
684d367c 215 ldisc = &ldisc_simple;
374330e2 216}
217
218static void refused_option (struct Opt *o) {
219 if (o->send == WILL && o->option == TELOPT_NEW_ENVIRON &&
220 o_oenv.state == INACTIVE) {
221 send_opt (WILL, TELOPT_OLD_ENVIRON);
222 o_oenv.state = REQUESTED;
223 }
2f938b83 224 if (o->option == TELOPT_ECHO && cfg.ldisc_term)
684d367c 225 ldisc = &ldisc_term;
374330e2 226}
227
228static void proc_rec_opt (int cmd, int option) {
229 struct Opt **o;
230
231 log_option ("server", cmd, option);
232 for (o = opts; *o; o++) {
233 if ((*o)->option == option && (*o)->ack == cmd) {
234 switch ((*o)->state) {
235 case REQUESTED:
236 (*o)->state = ACTIVE;
237 activate_option (*o);
238 break;
239 case ACTIVE:
240 break;
241 case INACTIVE:
242 (*o)->state = ACTIVE;
243 send_opt ((*o)->send, option);
244 activate_option (*o);
245 break;
246 case REALLY_INACTIVE:
247 send_opt ((*o)->nsend, option);
248 break;
249 }
250 return;
251 } else if ((*o)->option == option && (*o)->nak == cmd) {
252 switch ((*o)->state) {
253 case REQUESTED:
254 (*o)->state = INACTIVE;
255 refused_option (*o);
256 break;
257 case ACTIVE:
258 (*o)->state = INACTIVE;
259 send_opt ((*o)->nsend, option);
260 break;
261 case INACTIVE:
262 case REALLY_INACTIVE:
263 break;
264 }
265 return;
266 }
267 }
268 /*
269 * If we reach here, the option was one we weren't prepared to
270 * cope with. So send a negative ack.
271 */
272 send_opt ((cmd == WILL ? DONT : WONT), option);
273}
274
275static void process_subneg (void) {
276 unsigned char b[2048], *p, *q;
277 int var, value, n;
278 char *e;
279
280 switch (sb_opt) {
281 case TELOPT_TSPEED:
282 if (sb_len == 1 && sb_buf[0] == TELQUAL_SEND) {
283 char logbuf[sizeof(cfg.termspeed)+80];
284 b[0] = IAC; b[1] = SB; b[2] = TELOPT_TSPEED;
285 b[3] = TELQUAL_IS;
286 strcpy(b+4, cfg.termspeed);
287 n = 4 + strlen(cfg.termspeed);
288 b[n] = IAC; b[n+1] = SE;
289 s_write (b, n+2);
c5e9c988 290 logevent("server:\tSB TSPEED SEND");
374330e2 291 sprintf(logbuf, "client:\tSB TSPEED IS %s", cfg.termspeed);
c5e9c988 292 logevent (logbuf);
374330e2 293 } else
c5e9c988 294 logevent ("server:\tSB TSPEED <something weird>");
374330e2 295 break;
296 case TELOPT_TTYPE:
297 if (sb_len == 1 && sb_buf[0] == TELQUAL_SEND) {
298 char logbuf[sizeof(cfg.termtype)+80];
299 b[0] = IAC; b[1] = SB; b[2] = TELOPT_TTYPE;
300 b[3] = TELQUAL_IS;
301 for (n = 0; cfg.termtype[n]; n++)
302 b[n+4] = (cfg.termtype[n] >= 'a' && cfg.termtype[n] <= 'z' ?
303 cfg.termtype[n] + 'A'-'a' : cfg.termtype[n]);
304 b[n+4] = IAC; b[n+5] = SE;
305 s_write (b, n+6);
306 b[n+4] = 0;
c5e9c988 307 logevent("server:\tSB TTYPE SEND");
374330e2 308 sprintf(logbuf, "client:\tSB TTYPE IS %s", b+4);
c5e9c988 309 logevent(logbuf);
374330e2 310 } else
c5e9c988 311 logevent("server:\tSB TTYPE <something weird>\r\n");
374330e2 312 break;
313 case TELOPT_OLD_ENVIRON:
314 case TELOPT_NEW_ENVIRON:
315 p = sb_buf;
316 q = p + sb_len;
317 if (p < q && *p == TELQUAL_SEND) {
318 char logbuf[50];
319 p++;
320 sprintf (logbuf, "server:\tSB %s SEND", telopt(sb_opt));
c5e9c988 321 logevent (logbuf);
374330e2 322 if (sb_opt == TELOPT_OLD_ENVIRON) {
323 if (cfg.rfc_environ) {
324 value = RFC_VALUE;
325 var = RFC_VAR;
326 } else {
327 value = BSD_VALUE;
328 var = BSD_VAR;
329 }
330 /*
331 * Try to guess the sense of VAR and VALUE.
332 */
333 while (p < q) {
334 if (*p == RFC_VAR) {
335 value = RFC_VALUE;
336 var = RFC_VAR;
337 } else if (*p == BSD_VAR) {
338 value = BSD_VALUE;
339 var = BSD_VAR;
340 }
341 p++;
342 }
343 } else {
344 /*
345 * With NEW_ENVIRON, the sense of VAR and VALUE
346 * isn't in doubt.
347 */
348 value = RFC_VALUE;
349 var = RFC_VAR;
350 }
351 b[0] = IAC; b[1] = SB; b[2] = sb_opt;
352 b[3] = TELQUAL_IS;
353 n = 4;
37508af4 354 e = cfg.environmt;
374330e2 355 while (*e) {
356 b[n++] = var;
357 while (*e && *e != '\t') b[n++] = *e++;
358 if (*e == '\t') e++;
359 b[n++] = value;
360 while (*e) b[n++] = *e++;
361 e++;
362 }
363 if (*cfg.username) {
364 b[n++] = var; b[n++] = 'U'; b[n++] = 'S';
365 b[n++] = 'E'; b[n++] = 'R'; b[n++] = value;
366 e = cfg.username;
367 while (*e) b[n++] = *e++;
368 }
369 b[n++] = IAC; b[n++] = SE;
370 s_write (b, n);
371 sprintf(logbuf, "client:\tSB %s IS %s", telopt(sb_opt),
372 n==6 ? "<nothing>" : "<stuff>");
c5e9c988 373 logevent (logbuf);
374330e2 374 }
375 break;
376 }
377}
378
379static enum {
380 TOPLEVEL, SEENIAC, SEENWILL, SEENWONT, SEENDO, SEENDONT,
381 SEENSB, SUBNEGOT, SUBNEG_IAC, SEENCR
382} telnet_state = TOPLEVEL;
383
384static void do_telnet_read (char *buf, int len) {
374330e2 385
386 while (len--) {
387 int c = (unsigned char) *buf++;
388
389 switch (telnet_state) {
390 case TOPLEVEL:
391 case SEENCR:
392 if (c == NUL && telnet_state == SEENCR)
393 telnet_state = TOPLEVEL;
394 else if (c == IAC)
395 telnet_state = SEENIAC;
396 else {
374330e2 397 if (!in_synch)
c9def1b8 398 c_write1(c);
2f938b83 399
400#if 1
401 /* I can't get the F***ing winsock to insert the urgent IAC
402 * into the right position! Even with SO_OOBINLINE it gives
403 * it to recv too soon. And of course the DM byte (that
404 * arrives in the same packet!) appears several K later!!
405 *
406 * Oh well, we do get the DM in the right place so I'll
407 * just stop hiding on the next 0xf2 and hope for the best.
408 */
409 else if (c == DM) in_synch = 0;
410#endif
374330e2 411 if (c == CR)
412 telnet_state = SEENCR;
413 else
414 telnet_state = TOPLEVEL;
415 }
416 break;
417 case SEENIAC:
418 if (c == DO) telnet_state = SEENDO;
419 else if (c == DONT) telnet_state = SEENDONT;
420 else if (c == WILL) telnet_state = SEENWILL;
421 else if (c == WONT) telnet_state = SEENWONT;
422 else if (c == SB) telnet_state = SEENSB;
2f938b83 423 else if (c == DM) {
424 in_synch = 0;
425 telnet_state = TOPLEVEL;
426 }
300d41b0 427 else {
ded38628 428 /* ignore everything else; print it if it's IAC */
429 if (c == IAC) {
c9def1b8 430 c_write1(c);
ded38628 431 }
300d41b0 432 telnet_state = TOPLEVEL;
433 }
374330e2 434 break;
435 case SEENWILL:
436 proc_rec_opt (WILL, c);
437 telnet_state = TOPLEVEL;
438 break;
439 case SEENWONT:
440 proc_rec_opt (WONT, c);
441 telnet_state = TOPLEVEL;
442 break;
443 case SEENDO:
444 proc_rec_opt (DO, c);
445 telnet_state = TOPLEVEL;
446 break;
447 case SEENDONT:
448 proc_rec_opt (DONT, c);
449 telnet_state = TOPLEVEL;
450 break;
451 case SEENSB:
452 sb_opt = c;
453 sb_len = 0;
454 telnet_state = SUBNEGOT;
455 break;
456 case SUBNEGOT:
457 if (c == IAC)
458 telnet_state = SUBNEG_IAC;
459 else {
460 subneg_addchar:
461 if (sb_len >= sb_size) {
462 char *newbuf;
463 sb_size += SB_DELTA;
464 newbuf = (sb_buf ?
c9def1b8 465 srealloc(sb_buf, sb_size) :
466 smalloc(sb_size));
374330e2 467 if (newbuf)
468 sb_buf = newbuf;
469 else
470 sb_size -= SB_DELTA;
471 }
472 if (sb_len < sb_size)
473 sb_buf[sb_len++] = c;
474 telnet_state = SUBNEGOT;/* in case we came here by goto */
475 }
476 break;
477 case SUBNEG_IAC:
478 if (c != SE)
479 goto subneg_addchar; /* yes, it's a hack, I know, but... */
480 else {
481 process_subneg();
482 telnet_state = TOPLEVEL;
483 }
484 break;
485 }
486 }
487}
488
489/*
490 * Called to set up the Telnet connection. Will arrange for
491 * WM_NETEVENT messages to be passed to the specified window, whose
492 * window procedure should then call telnet_msg().
493 *
494 * Returns an error message, or NULL on success.
495 *
496 * Also places the canonical host name into `realhost'.
497 */
498static char *telnet_init (HWND hwnd, char *host, int port, char **realhost) {
499 SOCKADDR_IN addr;
500 struct hostent *h;
501 unsigned long a;
502
503 /*
504 * Try to find host.
505 */
506 if ( (a = inet_addr(host)) == (unsigned long) INADDR_NONE) {
507 if ( (h = gethostbyname(host)) == NULL)
508 switch (WSAGetLastError()) {
509 case WSAENETDOWN: return "Network is down";
510 case WSAHOST_NOT_FOUND: case WSANO_DATA:
511 return "Host does not exist";
512 case WSATRY_AGAIN: return "Host not found";
513 default: return "gethostbyname: unknown error";
514 }
515 memcpy (&a, h->h_addr, sizeof(a));
516 *realhost = h->h_name;
517 } else
518 *realhost = host;
519 a = ntohl(a);
520
521 if (port < 0)
522 port = 23; /* default telnet port */
523
524 /*
525 * Open socket.
526 */
527 s = socket(AF_INET, SOCK_STREAM, 0);
528 if (s == INVALID_SOCKET)
529 switch (WSAGetLastError()) {
530 case WSAENETDOWN: return "Network is down";
531 case WSAEAFNOSUPPORT: return "TCP/IP support not present";
532 default: return "socket(): unknown error";
533 }
534
374330e2 535 {
536 BOOL b = TRUE;
537 setsockopt (s, SOL_SOCKET, SO_OOBINLINE, (void *)&b, sizeof(b));
538 }
374330e2 539
540 /*
541 * Bind to local address.
542 */
543 addr.sin_family = AF_INET;
544 addr.sin_addr.s_addr = htonl(INADDR_ANY);
545 addr.sin_port = htons(0);
546 if (bind (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
547 switch (WSAGetLastError()) {
548 case WSAENETDOWN: return "Network is down";
549 default: return "bind(): unknown error";
550 }
551
552 /*
553 * Connect to remote address.
554 */
555 addr.sin_addr.s_addr = htonl(a);
556 addr.sin_port = htons((short)port);
557 if (connect (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
558 switch (WSAGetLastError()) {
559 case WSAENETDOWN: return "Network is down";
560 case WSAECONNREFUSED: return "Connection refused";
561 case WSAENETUNREACH: return "Network is unreachable";
562 case WSAEHOSTUNREACH: return "No route to host";
563 default: return "connect(): unknown error";
564 }
565
4017be6d 566 if (hwnd && WSAAsyncSelect (s, hwnd, WM_NETEVENT, FD_READ |
374330e2 567 FD_WRITE | FD_OOB | FD_CLOSE) == SOCKET_ERROR)
568 switch (WSAGetLastError()) {
569 case WSAENETDOWN: return "Network is down";
570 default: return "WSAAsyncSelect(): unknown error";
571 }
572
573 /*
574 * Initialise option states.
575 */
eb5e1db9 576 if( cfg.ldisc_term )
577 {
578 struct Opt **o;
579
580 for (o = opts; *o; o++)
581 if ((*o)->state == REQUESTED)
582 (*o)->state = INACTIVE;
583 }
584 else
374330e2 585 {
586 struct Opt **o;
587
588 for (o = opts; *o; o++)
589 if ((*o)->state == REQUESTED)
590 send_opt ((*o)->send, (*o)->option);
591 }
592
374330e2 593 /*
594 * Set up SYNCH state.
595 */
596 in_synch = FALSE;
6f34e365 597
598 /*
599 * We have no pre-session phase.
600 */
601 begin_session();
602
374330e2 603 return NULL;
604}
605
606/*
607 * Process a WM_NETEVENT message. Will return 0 if the connection
608 * has closed, or <0 for a socket error.
609 */
610static int telnet_msg (WPARAM wParam, LPARAM lParam) {
611 int ret;
c9def1b8 612 /* This needs to be larger than the packet size now that inbuf
613 * cannot overflow, in fact the fewer calls we make to windows
614 * the faster we will run!
615 */
616 char buf[16384];
374330e2 617
8ce72d2c 618 /*
619 * Because reading less than the whole of the available pending
620 * data can generate an FD_READ event, we need to allow for the
621 * possibility that FD_READ may arrive with FD_CLOSE already in
622 * the queue; so it's possible that we can get here even with s
623 * invalid. If so, we return 1 and don't worry about it.
624 */
625 if (s == INVALID_SOCKET)
626 return 1;
374330e2 627
8d5de777 628 if (WSAGETSELECTERROR(lParam) != 0) {
629 closesocket(s);
630 s = INVALID_SOCKET;
374330e2 631 return -WSAGETSELECTERROR(lParam);
8d5de777 632 }
374330e2 633
634 switch (WSAGETSELECTEVENT(lParam)) {
635 case FD_READ:
8ce72d2c 636 case FD_CLOSE:
2f938b83 637 {
638 int clear_of_oob = 1;
ec55b220 639
640 /* Don't check for error return; some shims don't support
641 * this ioctl.
642 */
643 ioctlsocket (s, SIOCATMARK, &clear_of_oob);
2f938b83 644
645 in_synch = !clear_of_oob;
646
647 do {
648 ret = recv(s, buf, sizeof(buf), 0);
649 if (ret < 0 && WSAGetLastError() == WSAEWOULDBLOCK)
650 return 1;
8d5de777 651 if (ret < 0) { /* any _other_ error */
652 closesocket(s);
653 s = INVALID_SOCKET;
2f938b83 654 return -10000-WSAGetLastError();
8d5de777 655 }
2f938b83 656 if (ret == 0) {
657 s = INVALID_SOCKET;
658 return 0;
659 }
2f938b83 660 do_telnet_read (buf, ret);
661 } while (in_synch);
374330e2 662 }
374330e2 663 return 1;
664 case FD_WRITE:
665 if (outbuf_head != outbuf_reap)
666 try_write();
667 return 1;
374330e2 668 }
669 return 1; /* shouldn't happen, but WTF */
670}
671
672/*
673 * Called to send data down the Telnet connection.
674 */
675static void telnet_send (char *buf, int len) {
676 char *p;
677 static unsigned char iac[2] = { IAC, IAC };
678 static unsigned char cr[2] = { CR, NUL };
eb5e1db9 679 static unsigned char nl[2] = { CR, LF };
374330e2 680
681 if (s == INVALID_SOCKET)
682 return;
683
684 p = buf;
2f938b83 685 while (p < buf+len) {
374330e2 686 char *q = p;
687
688 while (iswritable((unsigned char)*p) && p < buf+len) p++;
689 s_write (q, p-q);
690
691 while (p < buf+len && !iswritable((unsigned char)*p)) {
eb5e1db9 692 s_write ((unsigned char)*p == IAC ? iac : nl, 2);
374330e2 693 p++;
694 }
695 }
696}
697
698/*
699 * Called to set the size of the window from Telnet's POV.
700 */
701static void telnet_size(void) {
702 unsigned char b[16];
703 char logbuf[50];
704
705 if (s == INVALID_SOCKET || o_naws.state != ACTIVE)
706 return;
707 b[0] = IAC; b[1] = SB; b[2] = TELOPT_NAWS;
708 b[3] = cols >> 8; b[4] = cols & 0xFF;
709 b[5] = rows >> 8; b[6] = rows & 0xFF;
710 b[7] = IAC; b[8] = SE;
711 s_write (b, 9);
712 sprintf(logbuf, "client:\tSB NAWS %d,%d",
713 ((unsigned char)b[3] << 8) + (unsigned char)b[4],
714 ((unsigned char)b[5] << 8) + (unsigned char)b[6]);
c5e9c988 715 logevent (logbuf);
374330e2 716}
717
718/*
719 * Send Telnet special codes.
720 */
721static void telnet_special (Telnet_Special code) {
722 unsigned char b[2];
723
724 if (s == INVALID_SOCKET)
725 return;
726
727 b[0] = IAC;
728 switch (code) {
729 case TS_AYT: b[1] = AYT; s_write (b, 2); break;
730 case TS_BRK: b[1] = BREAK; s_write (b, 2); break;
731 case TS_EC: b[1] = EC; s_write (b, 2); break;
732 case TS_EL: b[1] = EL; s_write (b, 2); break;
733 case TS_GA: b[1] = GA; s_write (b, 2); break;
734 case TS_NOP: b[1] = NOP; s_write (b, 2); break;
735 case TS_ABORT: b[1] = ABORT; s_write (b, 2); break;
736 case TS_AO: b[1] = AO; s_write (b, 2); break;
737 case TS_IP: b[1] = IP; s_write (b, 2); break;
738 case TS_SUSP: b[1] = SUSP; s_write (b, 2); break;
739 case TS_EOR: b[1] = EOR; s_write (b, 2); break;
740 case TS_EOF: b[1] = xEOF; s_write (b, 2); break;
741 case TS_SYNCH:
742 outbuf_head = outbuf_reap = 0;
684d367c 743 b[1] = DM;
744 send (s, b, 2, MSG_OOB);
745 break;
746 case TS_RECHO:
747 if (o_echo.state == INACTIVE || o_echo.state == REALLY_INACTIVE) {
748 o_echo.state = REQUESTED;
749 send_opt (o_echo.send, o_echo.option);
750 }
751 break;
752 case TS_LECHO:
753 if (o_echo.state == ACTIVE) {
754 o_echo.state = REQUESTED;
755 send_opt (o_echo.nsend, o_echo.option);
756 }
374330e2 757 break;
ec55b220 758 case TS_PING:
759 if (o_they_sga.state == ACTIVE) {
760 b[1] = NOP;
761 s_write (b, 2);
762 }
763 break;
374330e2 764 }
765}
766
8ccc75b0 767static SOCKET telnet_socket(void) { return s; }
768
769static int telnet_sendok(void) { return 1; }
4017be6d 770
374330e2 771Backend telnet_backend = {
772 telnet_init,
773 telnet_msg,
774 telnet_send,
775 telnet_size,
4017be6d 776 telnet_special,
8ccc75b0 777 telnet_socket,
97db3be4 778 telnet_sendok,
779 23
374330e2 780};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator