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Fix printing of Telnet GA as ugrave
[u/mdw/putty] / telnet.c
1 #include <windows.h>
2 #include <stdio.h>
3 #include <stdlib.h>
4 #include <winsock.h>
5
6 #include "putty.h"
7
8 #ifndef FALSE
9 #define FALSE 0
10 #endif
11 #ifndef TRUE
12 #define TRUE 1
13 #endif
14
15 static SOCKET s = INVALID_SOCKET;
16
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 */
24
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... */
38
39 #define TELOPT_BINARY 0 /* 8-bit data path */
40 #define TELOPT_ECHO 1 /* echo */
41 #define TELOPT_RCP 2 /* prepare to reconnect */
42 #define TELOPT_SGA 3 /* suppress go ahead */
43 #define TELOPT_NAMS 4 /* approximate message size */
44 #define TELOPT_STATUS 5 /* give status */
45 #define TELOPT_TM 6 /* timing mark */
46 #define TELOPT_RCTE 7 /* remote controlled transmission and echo */
47 #define TELOPT_NAOL 8 /* negotiate about output line width */
48 #define TELOPT_NAOP 9 /* negotiate about output page size */
49 #define TELOPT_NAOCRD 10 /* negotiate about CR disposition */
50 #define TELOPT_NAOHTS 11 /* negotiate about horizontal tabstops */
51 #define TELOPT_NAOHTD 12 /* negotiate about horizontal tab disposition */
52 #define TELOPT_NAOFFD 13 /* negotiate about formfeed disposition */
53 #define TELOPT_NAOVTS 14 /* negotiate about vertical tab stops */
54 #define TELOPT_NAOVTD 15 /* negotiate about vertical tab disposition */
55 #define TELOPT_NAOLFD 16 /* negotiate about output LF disposition */
56 #define TELOPT_XASCII 17 /* extended ascic character set */
57 #define TELOPT_LOGOUT 18 /* force logout */
58 #define TELOPT_BM 19 /* byte macro */
59 #define TELOPT_DET 20 /* data entry terminal */
60 #define TELOPT_SUPDUP 21 /* supdup protocol */
61 #define TELOPT_SUPDUPOUTPUT 22 /* supdup output */
62 #define TELOPT_SNDLOC 23 /* send location */
63 #define TELOPT_TTYPE 24 /* terminal type */
64 #define TELOPT_EOR 25 /* end or record */
65 #define TELOPT_TUID 26 /* TACACS user identification */
66 #define TELOPT_OUTMRK 27 /* output marking */
67 #define TELOPT_TTYLOC 28 /* terminal location number */
68 #define TELOPT_3270REGIME 29 /* 3270 regime */
69 #define TELOPT_X3PAD 30 /* X.3 PAD */
70 #define TELOPT_NAWS 31 /* window size */
71 #define TELOPT_TSPEED 32 /* terminal speed */
72 #define TELOPT_LFLOW 33 /* remote flow control */
73 #define TELOPT_LINEMODE 34 /* Linemode option */
74 #define TELOPT_XDISPLOC 35 /* X Display Location */
75 #define TELOPT_OLD_ENVIRON 36 /* Old - Environment variables */
76 #define TELOPT_AUTHENTICATION 37/* Authenticate */
77 #define TELOPT_ENCRYPT 38 /* Encryption option */
78 #define TELOPT_NEW_ENVIRON 39 /* New - Environment variables */
79 #define TELOPT_EXOPL 255 /* extended-options-list */
80
81 #define TELQUAL_IS 0 /* option is... */
82 #define TELQUAL_SEND 1 /* send option */
83 #define TELQUAL_INFO 2 /* ENVIRON: informational version of IS */
84 #define BSD_VAR 1
85 #define BSD_VALUE 0
86 #define RFC_VAR 0
87 #define RFC_VALUE 1
88
89 #define CR 13
90 #define LF 10
91 #define NUL 0
92
93 #define iswritable(x) ( (x) != IAC && (x) != CR )
94
95 static char *telopt(int opt) {
96 #define i(x) if (opt == TELOPT_ ## x) return #x;
97 i(BINARY); i(ECHO); i(RCP); i(SGA); i(NAMS); i(STATUS); i(TM); i(RCTE);
98 i(NAOL); i(NAOP); i(NAOCRD); i(NAOHTS); i(NAOHTD); i(NAOFFD); i(NAOVTS);
99 i(NAOVTD); i(NAOLFD); i(XASCII); i(LOGOUT); i(BM); i(DET); i(SUPDUP);
100 i(SUPDUPOUTPUT); i(SNDLOC); i(TTYPE); i(EOR); i(TUID); i(OUTMRK);
101 i(TTYLOC); i(X3PAD); i(NAWS); i(TSPEED); i(LFLOW); i(LINEMODE);
102 i(XDISPLOC); i(OLD_ENVIRON); i(AUTHENTICATION); i(ENCRYPT);
103 i(NEW_ENVIRON); i(EXOPL);
104 #undef i
105 return "<unknown>";
106 }
107
108 static void telnet_size(void);
109
110 struct Opt {
111 int send; /* what we initially send */
112 int nsend; /* -ve send if requested to stop it */
113 int ack, nak; /* +ve and -ve acknowledgements */
114 int option; /* the option code */
115 enum {
116 REQUESTED, ACTIVE, INACTIVE, REALLY_INACTIVE
117 } state;
118 };
119
120 static struct Opt o_naws = {WILL, WONT, DO, DONT, TELOPT_NAWS, REQUESTED};
121 static struct Opt o_tspeed = {WILL, WONT, DO, DONT, TELOPT_TSPEED, REQUESTED};
122 static struct Opt o_ttype = {WILL, WONT, DO, DONT, TELOPT_TTYPE, REQUESTED};
123 static struct Opt o_oenv = {WILL, WONT, DO, DONT, TELOPT_OLD_ENVIRON,
124 INACTIVE};
125 static struct Opt o_nenv = {WILL, WONT, DO, DONT, TELOPT_NEW_ENVIRON,
126 REQUESTED};
127 static struct Opt o_echo = {DO, DONT, WILL, WONT, TELOPT_ECHO, REQUESTED};
128 static struct Opt o_we_sga = {WILL, WONT, DO, DONT, TELOPT_SGA, REQUESTED};
129 static struct Opt o_they_sga = {DO, DONT, WILL, WONT, TELOPT_SGA, REQUESTED};
130
131 static struct Opt *opts[] = {
132 &o_naws, &o_tspeed, &o_ttype, &o_oenv, &o_nenv, &o_echo,
133 &o_we_sga, &o_they_sga, NULL
134 };
135
136 #if 0
137 static int in_synch;
138 #endif
139
140 static int sb_opt, sb_len;
141 static char *sb_buf = NULL;
142 static int sb_size = 0;
143 #define SB_DELTA 1024
144
145 static void try_write (void) {
146 while (outbuf_head != outbuf_reap) {
147 int end = (outbuf_reap < outbuf_head ? outbuf_head : OUTBUF_SIZE);
148 int len = end - outbuf_reap;
149 int ret;
150
151 ret = send (s, outbuf+outbuf_reap, len, 0);
152 if (ret > 0)
153 outbuf_reap = (outbuf_reap + ret) & OUTBUF_MASK;
154 if (ret < len)
155 return;
156 }
157 }
158
159 static void s_write (void *buf, int len) {
160 unsigned char *p = buf;
161 while (len--) {
162 int new_head = (outbuf_head + 1) & OUTBUF_MASK;
163 if (new_head != outbuf_reap) {
164 outbuf[outbuf_head] = *p++;
165 outbuf_head = new_head;
166 }
167 }
168 try_write();
169 }
170
171 static void c_write (char *buf, int len) {
172 while (len--) {
173 int new_head = (inbuf_head + 1) & INBUF_MASK;
174 if (new_head != inbuf_reap) {
175 inbuf[inbuf_head] = *buf++;
176 inbuf_head = new_head;
177 }
178 }
179 }
180
181 static void log_option (char *sender, int cmd, int option) {
182 char buf[50];
183 sprintf(buf, "%s:\t%s %s", sender,
184 (cmd == WILL ? "WILL" : cmd == WONT ? "WONT" :
185 cmd == DO ? "DO" : cmd == DONT ? "DONT" : "<??>"),
186 telopt(option));
187 logevent(buf);
188 }
189
190 static void send_opt (int cmd, int option) {
191 unsigned char b[3];
192
193 b[0] = IAC; b[1] = cmd; b[2] = option;
194 s_write (b, 3);
195 log_option("client", cmd, option);
196 }
197
198 static void deactivate_option (struct Opt *o) {
199 if (o->state == REQUESTED || o->state == ACTIVE)
200 send_opt (o->nsend, o->option);
201 o->state = REALLY_INACTIVE;
202 }
203
204 static void activate_option (struct Opt *o) {
205 if (o->send == WILL && o->option == TELOPT_NAWS)
206 telnet_size();
207 if (o->send == WILL &&
208 (o->option == TELOPT_NEW_ENVIRON ||
209 o->option == TELOPT_OLD_ENVIRON)) {
210 /*
211 * We may only have one kind of ENVIRON going at a time.
212 * This is a hack, but who cares.
213 */
214 deactivate_option (o->option==TELOPT_NEW_ENVIRON ? &o_oenv : &o_nenv);
215 }
216 }
217
218 static 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 }
224 }
225
226 static void proc_rec_opt (int cmd, int option) {
227 struct Opt **o;
228
229 log_option ("server", cmd, option);
230 for (o = opts; *o; o++) {
231 if ((*o)->option == option && (*o)->ack == cmd) {
232 switch ((*o)->state) {
233 case REQUESTED:
234 (*o)->state = ACTIVE;
235 activate_option (*o);
236 break;
237 case ACTIVE:
238 break;
239 case INACTIVE:
240 (*o)->state = ACTIVE;
241 send_opt ((*o)->send, option);
242 activate_option (*o);
243 break;
244 case REALLY_INACTIVE:
245 send_opt ((*o)->nsend, option);
246 break;
247 }
248 return;
249 } else if ((*o)->option == option && (*o)->nak == cmd) {
250 switch ((*o)->state) {
251 case REQUESTED:
252 (*o)->state = INACTIVE;
253 refused_option (*o);
254 break;
255 case ACTIVE:
256 (*o)->state = INACTIVE;
257 send_opt ((*o)->nsend, option);
258 break;
259 case INACTIVE:
260 case REALLY_INACTIVE:
261 break;
262 }
263 return;
264 }
265 }
266 /*
267 * If we reach here, the option was one we weren't prepared to
268 * cope with. So send a negative ack.
269 */
270 send_opt ((cmd == WILL ? DONT : WONT), option);
271 }
272
273 static void process_subneg (void) {
274 unsigned char b[2048], *p, *q;
275 int var, value, n;
276 char *e;
277
278 switch (sb_opt) {
279 case TELOPT_TSPEED:
280 if (sb_len == 1 && sb_buf[0] == TELQUAL_SEND) {
281 char logbuf[sizeof(cfg.termspeed)+80];
282 b[0] = IAC; b[1] = SB; b[2] = TELOPT_TSPEED;
283 b[3] = TELQUAL_IS;
284 strcpy(b+4, cfg.termspeed);
285 n = 4 + strlen(cfg.termspeed);
286 b[n] = IAC; b[n+1] = SE;
287 s_write (b, n+2);
288 logevent("server:\tSB TSPEED SEND");
289 sprintf(logbuf, "client:\tSB TSPEED IS %s", cfg.termspeed);
290 logevent (logbuf);
291 } else
292 logevent ("server:\tSB TSPEED <something weird>");
293 break;
294 case TELOPT_TTYPE:
295 if (sb_len == 1 && sb_buf[0] == TELQUAL_SEND) {
296 char logbuf[sizeof(cfg.termtype)+80];
297 b[0] = IAC; b[1] = SB; b[2] = TELOPT_TTYPE;
298 b[3] = TELQUAL_IS;
299 for (n = 0; cfg.termtype[n]; n++)
300 b[n+4] = (cfg.termtype[n] >= 'a' && cfg.termtype[n] <= 'z' ?
301 cfg.termtype[n] + 'A'-'a' : cfg.termtype[n]);
302 b[n+4] = IAC; b[n+5] = SE;
303 s_write (b, n+6);
304 b[n+4] = 0;
305 logevent("server:\tSB TTYPE SEND");
306 sprintf(logbuf, "client:\tSB TTYPE IS %s", b+4);
307 logevent(logbuf);
308 } else
309 logevent("server:\tSB TTYPE <something weird>\r\n");
310 break;
311 case TELOPT_OLD_ENVIRON:
312 case TELOPT_NEW_ENVIRON:
313 p = sb_buf;
314 q = p + sb_len;
315 if (p < q && *p == TELQUAL_SEND) {
316 char logbuf[50];
317 p++;
318 sprintf (logbuf, "server:\tSB %s SEND", telopt(sb_opt));
319 logevent (logbuf);
320 if (sb_opt == TELOPT_OLD_ENVIRON) {
321 if (cfg.rfc_environ) {
322 value = RFC_VALUE;
323 var = RFC_VAR;
324 } else {
325 value = BSD_VALUE;
326 var = BSD_VAR;
327 }
328 /*
329 * Try to guess the sense of VAR and VALUE.
330 */
331 while (p < q) {
332 if (*p == RFC_VAR) {
333 value = RFC_VALUE;
334 var = RFC_VAR;
335 } else if (*p == BSD_VAR) {
336 value = BSD_VALUE;
337 var = BSD_VAR;
338 }
339 p++;
340 }
341 } else {
342 /*
343 * With NEW_ENVIRON, the sense of VAR and VALUE
344 * isn't in doubt.
345 */
346 value = RFC_VALUE;
347 var = RFC_VAR;
348 }
349 b[0] = IAC; b[1] = SB; b[2] = sb_opt;
350 b[3] = TELQUAL_IS;
351 n = 4;
352 e = cfg.environmt;
353 while (*e) {
354 b[n++] = var;
355 while (*e && *e != '\t') b[n++] = *e++;
356 if (*e == '\t') e++;
357 b[n++] = value;
358 while (*e) b[n++] = *e++;
359 e++;
360 }
361 if (*cfg.username) {
362 b[n++] = var; b[n++] = 'U'; b[n++] = 'S';
363 b[n++] = 'E'; b[n++] = 'R'; b[n++] = value;
364 e = cfg.username;
365 while (*e) b[n++] = *e++;
366 }
367 b[n++] = IAC; b[n++] = SE;
368 s_write (b, n);
369 sprintf(logbuf, "client:\tSB %s IS %s", telopt(sb_opt),
370 n==6 ? "<nothing>" : "<stuff>");
371 logevent (logbuf);
372 }
373 break;
374 }
375 }
376
377 static enum {
378 TOPLEVEL, SEENIAC, SEENWILL, SEENWONT, SEENDO, SEENDONT,
379 SEENSB, SUBNEGOT, SUBNEG_IAC, SEENCR
380 } telnet_state = TOPLEVEL;
381
382 static void do_telnet_read (char *buf, int len) {
383 unsigned char b[10];
384
385 while (len--) {
386 int c = (unsigned char) *buf++;
387
388 switch (telnet_state) {
389 case TOPLEVEL:
390 case SEENCR:
391 if (c == NUL && telnet_state == SEENCR)
392 telnet_state = TOPLEVEL;
393 else if (c == IAC)
394 telnet_state = SEENIAC;
395 else {
396 b[0] = c;
397 #if 0
398 if (!in_synch)
399 #endif
400 c_write (b, 1);
401 if (c == CR)
402 telnet_state = SEENCR;
403 else
404 telnet_state = TOPLEVEL;
405 }
406 break;
407 case SEENIAC:
408 if (c == DO) telnet_state = SEENDO;
409 else if (c == DONT) telnet_state = SEENDONT;
410 else if (c == WILL) telnet_state = SEENWILL;
411 else if (c == WONT) telnet_state = SEENWONT;
412 else if (c == SB) telnet_state = SEENSB;
413 else {
414 /* ignore everything else; print it if it's IAC */
415 if (c == IAC) {
416 b[0] = c;
417 c_write(b,1);
418 }
419 telnet_state = TOPLEVEL;
420 }
421 break;
422 case SEENWILL:
423 proc_rec_opt (WILL, c);
424 telnet_state = TOPLEVEL;
425 break;
426 case SEENWONT:
427 proc_rec_opt (WONT, c);
428 telnet_state = TOPLEVEL;
429 break;
430 case SEENDO:
431 proc_rec_opt (DO, c);
432 telnet_state = TOPLEVEL;
433 break;
434 case SEENDONT:
435 proc_rec_opt (DONT, c);
436 telnet_state = TOPLEVEL;
437 break;
438 case SEENSB:
439 sb_opt = c;
440 sb_len = 0;
441 telnet_state = SUBNEGOT;
442 break;
443 case SUBNEGOT:
444 if (c == IAC)
445 telnet_state = SUBNEG_IAC;
446 else {
447 subneg_addchar:
448 if (sb_len >= sb_size) {
449 char *newbuf;
450 sb_size += SB_DELTA;
451 newbuf = (sb_buf ?
452 realloc(sb_buf, sb_size) :
453 malloc(sb_size));
454 if (newbuf)
455 sb_buf = newbuf;
456 else
457 sb_size -= SB_DELTA;
458 }
459 if (sb_len < sb_size)
460 sb_buf[sb_len++] = c;
461 telnet_state = SUBNEGOT;/* in case we came here by goto */
462 }
463 break;
464 case SUBNEG_IAC:
465 if (c != SE)
466 goto subneg_addchar; /* yes, it's a hack, I know, but... */
467 else {
468 process_subneg();
469 telnet_state = TOPLEVEL;
470 }
471 break;
472 }
473 }
474 }
475
476 /*
477 * Called to set up the Telnet connection. Will arrange for
478 * WM_NETEVENT messages to be passed to the specified window, whose
479 * window procedure should then call telnet_msg().
480 *
481 * Returns an error message, or NULL on success.
482 *
483 * Also places the canonical host name into `realhost'.
484 */
485 static char *telnet_init (HWND hwnd, char *host, int port, char **realhost) {
486 SOCKADDR_IN addr;
487 struct hostent *h;
488 unsigned long a;
489
490 /*
491 * Try to find host.
492 */
493 if ( (a = inet_addr(host)) == (unsigned long) INADDR_NONE) {
494 if ( (h = gethostbyname(host)) == NULL)
495 switch (WSAGetLastError()) {
496 case WSAENETDOWN: return "Network is down";
497 case WSAHOST_NOT_FOUND: case WSANO_DATA:
498 return "Host does not exist";
499 case WSATRY_AGAIN: return "Host not found";
500 default: return "gethostbyname: unknown error";
501 }
502 memcpy (&a, h->h_addr, sizeof(a));
503 *realhost = h->h_name;
504 } else
505 *realhost = host;
506 a = ntohl(a);
507
508 if (port < 0)
509 port = 23; /* default telnet port */
510
511 /*
512 * Open socket.
513 */
514 s = socket(AF_INET, SOCK_STREAM, 0);
515 if (s == INVALID_SOCKET)
516 switch (WSAGetLastError()) {
517 case WSAENETDOWN: return "Network is down";
518 case WSAEAFNOSUPPORT: return "TCP/IP support not present";
519 default: return "socket(): unknown error";
520 }
521
522 #if 0
523 {
524 BOOL b = TRUE;
525 setsockopt (s, SOL_SOCKET, SO_OOBINLINE, (void *)&b, sizeof(b));
526 }
527 #endif
528
529 /*
530 * Bind to local address.
531 */
532 addr.sin_family = AF_INET;
533 addr.sin_addr.s_addr = htonl(INADDR_ANY);
534 addr.sin_port = htons(0);
535 if (bind (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
536 switch (WSAGetLastError()) {
537 case WSAENETDOWN: return "Network is down";
538 default: return "bind(): unknown error";
539 }
540
541 /*
542 * Connect to remote address.
543 */
544 addr.sin_addr.s_addr = htonl(a);
545 addr.sin_port = htons((short)port);
546 if (connect (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
547 switch (WSAGetLastError()) {
548 case WSAENETDOWN: return "Network is down";
549 case WSAECONNREFUSED: return "Connection refused";
550 case WSAENETUNREACH: return "Network is unreachable";
551 case WSAEHOSTUNREACH: return "No route to host";
552 default: return "connect(): unknown error";
553 }
554
555 if (WSAAsyncSelect (s, hwnd, WM_NETEVENT, FD_READ |
556 FD_WRITE | FD_OOB | FD_CLOSE) == SOCKET_ERROR)
557 switch (WSAGetLastError()) {
558 case WSAENETDOWN: return "Network is down";
559 default: return "WSAAsyncSelect(): unknown error";
560 }
561
562 /*
563 * Initialise option states.
564 */
565 {
566 struct Opt **o;
567
568 for (o = opts; *o; o++)
569 if ((*o)->state == REQUESTED)
570 send_opt ((*o)->send, (*o)->option);
571 }
572
573 #if 0
574 /*
575 * Set up SYNCH state.
576 */
577 in_synch = FALSE;
578 #endif
579
580 return NULL;
581 }
582
583 /*
584 * Process a WM_NETEVENT message. Will return 0 if the connection
585 * has closed, or <0 for a socket error.
586 */
587 static int telnet_msg (WPARAM wParam, LPARAM lParam) {
588 int ret;
589 char buf[256];
590
591 /*
592 * Because reading less than the whole of the available pending
593 * data can generate an FD_READ event, we need to allow for the
594 * possibility that FD_READ may arrive with FD_CLOSE already in
595 * the queue; so it's possible that we can get here even with s
596 * invalid. If so, we return 1 and don't worry about it.
597 */
598 if (s == INVALID_SOCKET)
599 return 1;
600
601 if (WSAGETSELECTERROR(lParam) != 0)
602 return -WSAGETSELECTERROR(lParam);
603
604 switch (WSAGETSELECTEVENT(lParam)) {
605 case FD_READ:
606 case FD_CLOSE:
607 ret = recv(s, buf, sizeof(buf), 0);
608 if (ret < 0 && WSAGetLastError() == WSAEWOULDBLOCK)
609 return 1;
610 if (ret < 0) /* any _other_ error */
611 return -10000-WSAGetLastError();
612 if (ret == 0) {
613 s = INVALID_SOCKET;
614 return 0;
615 }
616 #if 0
617 if (in_synch) {
618 BOOL i;
619 if (ioctlsocket (s, SIOCATMARK, &i) < 0) {
620 return -20000-WSAGetLastError();
621 }
622 if (i)
623 in_synch = FALSE;
624 }
625 #endif
626 do_telnet_read (buf, ret);
627 return 1;
628 case FD_OOB:
629 do {
630 ret = recv(s, buf, sizeof(buf), 0);
631 } while (ret > 0);
632 telnet_state = TOPLEVEL;
633 do {
634 ret = recv(s, buf, 1, MSG_OOB);
635 if (ret > 0)
636 do_telnet_read (buf, ret);
637 } while (ret > 0);
638 if (ret < 0 && WSAGetLastError() != WSAEWOULDBLOCK)
639 return -30000-WSAGetLastError();
640 return 1;
641 case FD_WRITE:
642 if (outbuf_head != outbuf_reap)
643 try_write();
644 return 1;
645 }
646 return 1; /* shouldn't happen, but WTF */
647 }
648
649 /*
650 * Called to send data down the Telnet connection.
651 */
652 static void telnet_send (char *buf, int len) {
653 char *p;
654 static unsigned char iac[2] = { IAC, IAC };
655 static unsigned char cr[2] = { CR, NUL };
656
657 if (s == INVALID_SOCKET)
658 return;
659
660 p = buf;
661 while (p < buf+len) {
662 char *q = p;
663
664 while (iswritable((unsigned char)*p) && p < buf+len) p++;
665 s_write (q, p-q);
666
667 while (p < buf+len && !iswritable((unsigned char)*p)) {
668 s_write ((unsigned char)*p == IAC ? iac : cr, 2);
669 p++;
670 }
671 }
672 }
673
674 /*
675 * Called to set the size of the window from Telnet's POV.
676 */
677 static void telnet_size(void) {
678 unsigned char b[16];
679 char logbuf[50];
680
681 if (s == INVALID_SOCKET || o_naws.state != ACTIVE)
682 return;
683 b[0] = IAC; b[1] = SB; b[2] = TELOPT_NAWS;
684 b[3] = cols >> 8; b[4] = cols & 0xFF;
685 b[5] = rows >> 8; b[6] = rows & 0xFF;
686 b[7] = IAC; b[8] = SE;
687 s_write (b, 9);
688 sprintf(logbuf, "client:\tSB NAWS %d,%d",
689 ((unsigned char)b[3] << 8) + (unsigned char)b[4],
690 ((unsigned char)b[5] << 8) + (unsigned char)b[6]);
691 logevent (logbuf);
692 }
693
694 /*
695 * Send Telnet special codes.
696 */
697 static void telnet_special (Telnet_Special code) {
698 unsigned char b[2];
699
700 if (s == INVALID_SOCKET)
701 return;
702
703 b[0] = IAC;
704 switch (code) {
705 case TS_AYT: b[1] = AYT; s_write (b, 2); break;
706 case TS_BRK: b[1] = BREAK; s_write (b, 2); break;
707 case TS_EC: b[1] = EC; s_write (b, 2); break;
708 case TS_EL: b[1] = EL; s_write (b, 2); break;
709 case TS_GA: b[1] = GA; s_write (b, 2); break;
710 case TS_NOP: b[1] = NOP; s_write (b, 2); break;
711 case TS_ABORT: b[1] = ABORT; s_write (b, 2); break;
712 case TS_AO: b[1] = AO; s_write (b, 2); break;
713 case TS_IP: b[1] = IP; s_write (b, 2); break;
714 case TS_SUSP: b[1] = SUSP; s_write (b, 2); break;
715 case TS_EOR: b[1] = EOR; s_write (b, 2); break;
716 case TS_EOF: b[1] = xEOF; s_write (b, 2); break;
717 case TS_SYNCH:
718 outbuf_head = outbuf_reap = 0;
719 b[0] = DM;
720 send (s, b, 1, MSG_OOB);
721 break;
722 }
723 }
724
725 Backend telnet_backend = {
726 telnet_init,
727 telnet_msg,
728 telnet_send,
729 telnet_size,
730 telnet_special
731 };
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator