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First crack at `terminal-modes' in SSH. PuTTY now sends ERASE by default,
[sgt/putty] / unix / uxplink.c
1 /*
2 * PLink - a command-line (stdin/stdout) variant of PuTTY.
3 */
4
5 #include <stdio.h>
6 #include <stdlib.h>
7 #include <errno.h>
8 #include <assert.h>
9 #include <stdarg.h>
10 #include <signal.h>
11 #include <unistd.h>
12 #include <fcntl.h>
13 #include <termios.h>
14 #include <pwd.h>
15 #include <sys/ioctl.h>
16 #include <sys/select.h>
17
18 #define PUTTY_DO_GLOBALS /* actually _define_ globals */
19 #include "putty.h"
20 #include "storage.h"
21 #include "tree234.h"
22
23 #define MAX_STDIN_BACKLOG 4096
24
25 void fatalbox(char *p, ...)
26 {
27 va_list ap;
28 fprintf(stderr, "FATAL ERROR: ");
29 va_start(ap, p);
30 vfprintf(stderr, p, ap);
31 va_end(ap);
32 fputc('\n', stderr);
33 cleanup_exit(1);
34 }
35 void modalfatalbox(char *p, ...)
36 {
37 va_list ap;
38 fprintf(stderr, "FATAL ERROR: ");
39 va_start(ap, p);
40 vfprintf(stderr, p, ap);
41 va_end(ap);
42 fputc('\n', stderr);
43 cleanup_exit(1);
44 }
45 void connection_fatal(void *frontend, char *p, ...)
46 {
47 va_list ap;
48 fprintf(stderr, "FATAL ERROR: ");
49 va_start(ap, p);
50 vfprintf(stderr, p, ap);
51 va_end(ap);
52 fputc('\n', stderr);
53 cleanup_exit(1);
54 }
55 void cmdline_error(char *p, ...)
56 {
57 va_list ap;
58 fprintf(stderr, "plink: ");
59 va_start(ap, p);
60 vfprintf(stderr, p, ap);
61 va_end(ap);
62 fputc('\n', stderr);
63 exit(1);
64 }
65
66 static int local_tty = 0; /* do we have a local tty? */
67 static struct termios orig_termios;
68
69 static Backend *back;
70 static void *backhandle;
71 static Config cfg;
72
73 /*
74 * Default settings that are specific to pterm.
75 */
76 char *platform_default_s(const char *name)
77 {
78 if (!strcmp(name, "TermType"))
79 return dupstr(getenv("TERM"));
80 if (!strcmp(name, "UserName"))
81 return get_username();
82 return NULL;
83 }
84
85 int platform_default_i(const char *name, int def)
86 {
87 if (!strcmp(name, "TermWidth") ||
88 !strcmp(name, "TermHeight")) {
89 struct winsize size;
90 if (ioctl(0, TIOCGWINSZ, (void *)&size) >= 0)
91 return (!strcmp(name, "TermWidth") ? size.ws_col : size.ws_row);
92 }
93 return def;
94 }
95
96 FontSpec platform_default_fontspec(const char *name)
97 {
98 FontSpec ret;
99 *ret.name = '\0';
100 return ret;
101 }
102
103 Filename platform_default_filename(const char *name)
104 {
105 Filename ret;
106 if (!strcmp(name, "LogFileName"))
107 strcpy(ret.path, "putty.log");
108 else
109 *ret.path = '\0';
110 return ret;
111 }
112
113 char *x_get_default(const char *key)
114 {
115 return NULL; /* this is a stub */
116 }
117 int term_ldisc(Terminal *term, int mode)
118 {
119 return FALSE;
120 }
121 void ldisc_update(void *frontend, int echo, int edit)
122 {
123 /* Update stdin read mode to reflect changes in line discipline. */
124 struct termios mode;
125
126 if (!local_tty) return;
127
128 mode = orig_termios;
129
130 if (echo)
131 mode.c_lflag |= ECHO;
132 else
133 mode.c_lflag &= ~ECHO;
134
135 if (edit) {
136 mode.c_iflag |= ICRNL;
137 mode.c_lflag |= ISIG | ICANON;
138 } else {
139 mode.c_iflag &= ~ICRNL;
140 mode.c_lflag &= ~(ISIG | ICANON);
141 /* Solaris sets these to unhelpful values */
142 mode.c_cc[VMIN] = 1;
143 mode.c_cc[VTIME] = 0;
144 /* FIXME: perhaps what we do with IXON/IXOFF should be an
145 * argument to ldisc_update(), to allow implementation of SSH-2
146 * "xon-xoff" and Rlogin's equivalent? */
147 mode.c_iflag &= ~IXON;
148 mode.c_iflag &= ~IXOFF;
149 }
150
151 tcsetattr(0, TCSANOW, &mode);
152 }
153
154 /* Helper function to extract a special character from a termios. */
155 static char *get_ttychar(struct termios *t, int index)
156 {
157 cc_t c = t->c_cc[index];
158 #if defined(_POSIX_VDISABLE)
159 if (c == _POSIX_VDISABLE)
160 return dupprintf("");
161 #endif
162 return dupprintf("^<%d>", c);
163 }
164
165 char *get_ttymode(void *frontend, const char *mode)
166 {
167 /*
168 * Propagate appropriate terminal modes from the local terminal,
169 * if any.
170 */
171 if (!local_tty) return NULL;
172
173 #define GET_CHAR(ourname, uxname) \
174 do { \
175 if (strcmp(mode, ourname) == 0) \
176 return get_ttychar(&orig_termios, uxname); \
177 } while(0)
178 #define GET_BOOL(ourname, uxname, uxmemb, transform) \
179 do { \
180 if (strcmp(mode, ourname) == 0) { \
181 int b = (orig_termios.uxmemb & uxname) != 0; \
182 transform; \
183 return dupprintf("%d", b); \
184 } \
185 } while (0)
186
187 /*
188 * Modes that want to be the same on all terminal devices involved.
189 */
190 /* All the special characters supported by SSH */
191 #if defined(VINTR)
192 GET_CHAR("INTR", VINTR);
193 #endif
194 #if defined(VQUIT)
195 GET_CHAR("QUIT", VQUIT);
196 #endif
197 #if defined(VERASE)
198 GET_CHAR("ERASE", VERASE);
199 #endif
200 #if defined(VKILL)
201 GET_CHAR("KILL", VKILL);
202 #endif
203 #if defined(VEOF)
204 GET_CHAR("EOF", VEOF);
205 #endif
206 #if defined(VEOL)
207 GET_CHAR("EOL", VEOL);
208 #endif
209 #if defined(VEOL2)
210 GET_CHAR("EOL2", VEOL2);
211 #endif
212 #if defined(VSTART)
213 GET_CHAR("START", VSTART);
214 #endif
215 #if defined(VSTOP)
216 GET_CHAR("STOP", VSTOP);
217 #endif
218 #if defined(VSUSP)
219 GET_CHAR("SUSP", VSUSP);
220 #endif
221 #if defined(VDSUSP)
222 GET_CHAR("DSUSP", VDSUSP);
223 #endif
224 #if defined(VREPRINT)
225 GET_CHAR("REPRINT", VREPRINT);
226 #endif
227 #if defined(VWERASE)
228 GET_CHAR("WERASE", VWERASE);
229 #endif
230 #if defined(VLNEXT)
231 GET_CHAR("LNEXT", VLNEXT);
232 #endif
233 #if defined(VFLUSH)
234 GET_CHAR("FLUSH", VFLUSH);
235 #endif
236 #if defined(VSWTCH)
237 GET_CHAR("SWTCH", VSWTCH);
238 #endif
239 #if defined(VSTATUS)
240 GET_CHAR("STATUS", VSTATUS);
241 #endif
242 #if defined(VDISCARD)
243 GET_CHAR("DISCARD", VDISCARD);
244 #endif
245 /* Modes that "configure" other major modes. These should probably be
246 * considered as user preferences. */
247 /* Configuration of ICANON */
248 #if defined(ECHOK)
249 GET_BOOL("ECHOK", ECHOK, c_lflag, );
250 #endif
251 #if defined(ECHOKE)
252 GET_BOOL("ECHOKE", ECHOKE, c_lflag, );
253 #endif
254 #if defined(ECHOE)
255 GET_BOOL("ECHOE", ECHOE, c_lflag, );
256 #endif
257 #if defined(ECHONL)
258 GET_BOOL("ECHONL", ECHONL, c_lflag, );
259 #endif
260 #if defined(XCASE)
261 GET_BOOL("XCASE", XCASE, c_lflag, );
262 #endif
263 /* Configuration of ECHO */
264 #if defined(ECHOCTL)
265 GET_BOOL("ECHOCTL", ECHOCTL, c_lflag, );
266 #endif
267 /* Configuration of IXON/IXOFF */
268 #if defined(IXANY)
269 GET_BOOL("IXANY", IXANY, c_iflag, );
270 #endif
271
272 /*
273 * Modes that want to be set in only one place, and that we have
274 * squashed locally.
275 */
276 #if defined(ISIG)
277 GET_BOOL("ISIG", ISIG, c_lflag, );
278 #endif
279 #if defined(ICANON)
280 GET_BOOL("ICANON", ICANON, c_lflag, );
281 #endif
282 #if defined(ECHO)
283 GET_BOOL("ECHO", ECHO, c_lflag, );
284 #endif
285 #if defined(IXON)
286 GET_BOOL("IXON", IXON, c_iflag, );
287 #endif
288 #if defined(IXOFF)
289 GET_BOOL("IXOFF", IXOFF, c_iflag, );
290 #endif
291
292 /*
293 * We do not propagate the following modes:
294 * - Parity/serial settings, which are a local affair and don't
295 * make sense propagated over SSH's 8-bit byte-stream.
296 * IGNPAR PARMRK INPCK CS7 CS8 PARENB PARODD
297 * - Things that want to be enabled in one place that we don't
298 * squash locally.
299 * IUCLC OLCUC
300 * - Status bits.
301 * PENDIN
302 * - Things I don't know what to do with. (FIXME)
303 * ISTRIP IMAXBEL NOFLSH TOSTOP IEXTEN OPOST
304 * INLCR IGNCR ICRNL ONLCR OCRNL ONOCR ONLRET
305 */
306
307 #undef GET_CHAR
308 #undef GET_BOOL
309
310 /* Fall through to here for unrecognised names, or ones that are
311 * unsupported on this platform */
312 return NULL;
313 }
314
315 void cleanup_termios(void)
316 {
317 if (local_tty)
318 tcsetattr(0, TCSANOW, &orig_termios);
319 }
320
321 bufchain stdout_data, stderr_data;
322
323 void try_output(int is_stderr)
324 {
325 bufchain *chain = (is_stderr ? &stderr_data : &stdout_data);
326 int fd = (is_stderr ? 2 : 1);
327 void *senddata;
328 int sendlen, ret;
329
330 if (bufchain_size(chain) == 0)
331 return;
332
333 bufchain_prefix(chain, &senddata, &sendlen);
334 ret = write(fd, senddata, sendlen);
335 if (ret > 0)
336 bufchain_consume(chain, ret);
337 else if (ret < 0) {
338 perror(is_stderr ? "stderr: write" : "stdout: write");
339 exit(1);
340 }
341 }
342
343 int from_backend(void *frontend_handle, int is_stderr,
344 const char *data, int len)
345 {
346 int osize, esize;
347
348 if (is_stderr) {
349 bufchain_add(&stderr_data, data, len);
350 try_output(1);
351 } else {
352 bufchain_add(&stdout_data, data, len);
353 try_output(0);
354 }
355
356 osize = bufchain_size(&stdout_data);
357 esize = bufchain_size(&stderr_data);
358
359 return osize + esize;
360 }
361
362 int signalpipe[2];
363
364 void sigwinch(int signum)
365 {
366 write(signalpipe[1], "x", 1);
367 }
368
369 /*
370 * In Plink our selects are synchronous, so these functions are
371 * empty stubs.
372 */
373 int uxsel_input_add(int fd, int rwx) { return 0; }
374 void uxsel_input_remove(int id) { }
375
376 /*
377 * Short description of parameters.
378 */
379 static void usage(void)
380 {
381 printf("PuTTY Link: command-line connection utility\n");
382 printf("%s\n", ver);
383 printf("Usage: plink [options] [user@]host [command]\n");
384 printf(" (\"host\" can also be a PuTTY saved session name)\n");
385 printf("Options:\n");
386 printf(" -V print version information and exit\n");
387 printf(" -pgpfp print PGP key fingerprints and exit\n");
388 printf(" -v show verbose messages\n");
389 printf(" -load sessname Load settings from saved session\n");
390 printf(" -ssh -telnet -rlogin -raw\n");
391 printf(" force use of a particular protocol\n");
392 printf(" -P port connect to specified port\n");
393 printf(" -l user connect with specified username\n");
394 printf(" -batch disable all interactive prompts\n");
395 printf("The following options only apply to SSH connections:\n");
396 printf(" -pw passw login with specified password\n");
397 printf(" -D [listen-IP:]listen-port\n");
398 printf(" Dynamic SOCKS-based port forwarding\n");
399 printf(" -L [listen-IP:]listen-port:host:port\n");
400 printf(" Forward local port to remote address\n");
401 printf(" -R [listen-IP:]listen-port:host:port\n");
402 printf(" Forward remote port to local address\n");
403 printf(" -X -x enable / disable X11 forwarding\n");
404 printf(" -A -a enable / disable agent forwarding\n");
405 printf(" -t -T enable / disable pty allocation\n");
406 printf(" -1 -2 force use of particular protocol version\n");
407 printf(" -4 -6 force use of IPv4 or IPv6\n");
408 printf(" -C enable compression\n");
409 printf(" -i key private key file for authentication\n");
410 printf(" -m file read remote command(s) from file\n");
411 printf(" -s remote command is an SSH subsystem (SSH-2 only)\n");
412 printf(" -N don't start a shell/command (SSH-2 only)\n");
413 exit(1);
414 }
415
416 static void version(void)
417 {
418 printf("plink: %s\n", ver);
419 exit(1);
420 }
421
422 int main(int argc, char **argv)
423 {
424 int sending;
425 int portnumber = -1;
426 int *fdlist;
427 int fd;
428 int i, fdcount, fdsize, fdstate;
429 int connopen;
430 int exitcode;
431 int errors;
432 int use_subsystem = 0;
433 void *ldisc, *logctx;
434 long now;
435
436 ssh_get_line = console_get_line;
437
438 fdlist = NULL;
439 fdcount = fdsize = 0;
440 /*
441 * Initialise port and protocol to sensible defaults. (These
442 * will be overridden by more or less anything.)
443 */
444 default_protocol = PROT_SSH;
445 default_port = 22;
446
447 flags = FLAG_STDERR;
448 /*
449 * Process the command line.
450 */
451 do_defaults(NULL, &cfg);
452 loaded_session = FALSE;
453 default_protocol = cfg.protocol;
454 default_port = cfg.port;
455 errors = 0;
456 {
457 /*
458 * Override the default protocol if PLINK_PROTOCOL is set.
459 */
460 char *p = getenv("PLINK_PROTOCOL");
461 int i;
462 if (p) {
463 for (i = 0; backends[i].backend != NULL; i++) {
464 if (!strcmp(backends[i].name, p)) {
465 default_protocol = cfg.protocol = backends[i].protocol;
466 default_port = cfg.port =
467 backends[i].backend->default_port;
468 break;
469 }
470 }
471 }
472 }
473 while (--argc) {
474 char *p = *++argv;
475 if (*p == '-') {
476 int ret = cmdline_process_param(p, (argc > 1 ? argv[1] : NULL),
477 1, &cfg);
478 if (ret == -2) {
479 fprintf(stderr,
480 "plink: option \"%s\" requires an argument\n", p);
481 errors = 1;
482 } else if (ret == 2) {
483 --argc, ++argv;
484 } else if (ret == 1) {
485 continue;
486 } else if (!strcmp(p, "-batch")) {
487 console_batch_mode = 1;
488 } else if (!strcmp(p, "-s")) {
489 /* Save status to write to cfg later. */
490 use_subsystem = 1;
491 } else if (!strcmp(p, "-V")) {
492 version();
493 } else if (!strcmp(p, "-pgpfp")) {
494 pgp_fingerprints();
495 exit(1);
496 } else if (!strcmp(p, "-o")) {
497 if (argc <= 1) {
498 fprintf(stderr,
499 "plink: option \"-o\" requires an argument\n");
500 errors = 1;
501 } else {
502 --argc;
503 provide_xrm_string(*++argv);
504 }
505 } else {
506 fprintf(stderr, "plink: unknown option \"%s\"\n", p);
507 errors = 1;
508 }
509 } else if (*p) {
510 if (!*cfg.host) {
511 char *q = p;
512
513 do_defaults(NULL, &cfg);
514
515 /*
516 * If the hostname starts with "telnet:", set the
517 * protocol to Telnet and process the string as a
518 * Telnet URL.
519 */
520 if (!strncmp(q, "telnet:", 7)) {
521 char c;
522
523 q += 7;
524 if (q[0] == '/' && q[1] == '/')
525 q += 2;
526 cfg.protocol = PROT_TELNET;
527 p = q;
528 while (*p && *p != ':' && *p != '/')
529 p++;
530 c = *p;
531 if (*p)
532 *p++ = '\0';
533 if (c == ':')
534 cfg.port = atoi(p);
535 else
536 cfg.port = -1;
537 strncpy(cfg.host, q, sizeof(cfg.host) - 1);
538 cfg.host[sizeof(cfg.host) - 1] = '\0';
539 } else {
540 char *r, *user, *host;
541 /*
542 * Before we process the [user@]host string, we
543 * first check for the presence of a protocol
544 * prefix (a protocol name followed by ",").
545 */
546 r = strchr(p, ',');
547 if (r) {
548 int i, j;
549 for (i = 0; backends[i].backend != NULL; i++) {
550 j = strlen(backends[i].name);
551 if (j == r - p &&
552 !memcmp(backends[i].name, p, j)) {
553 default_protocol = cfg.protocol =
554 backends[i].protocol;
555 portnumber =
556 backends[i].backend->default_port;
557 p = r + 1;
558 break;
559 }
560 }
561 }
562
563 /*
564 * A nonzero length string followed by an @ is treated
565 * as a username. (We discount an _initial_ @.) The
566 * rest of the string (or the whole string if no @)
567 * is treated as a session name and/or hostname.
568 */
569 r = strrchr(p, '@');
570 if (r == p)
571 p++, r = NULL; /* discount initial @ */
572 if (r) {
573 *r++ = '\0';
574 user = p, host = r;
575 } else {
576 user = NULL, host = p;
577 }
578
579 /*
580 * Now attempt to load a saved session with the
581 * same name as the hostname.
582 */
583 {
584 Config cfg2;
585 do_defaults(host, &cfg2);
586 if (loaded_session || cfg2.host[0] == '\0') {
587 /* No settings for this host; use defaults */
588 /* (or session was already loaded with -load) */
589 strncpy(cfg.host, host, sizeof(cfg.host) - 1);
590 cfg.host[sizeof(cfg.host) - 1] = '\0';
591 cfg.port = default_port;
592 } else {
593 cfg = cfg2;
594 }
595 }
596
597 if (user) {
598 /* Patch in specified username. */
599 strncpy(cfg.username, user,
600 sizeof(cfg.username) - 1);
601 cfg.username[sizeof(cfg.username) - 1] = '\0';
602 }
603
604 }
605 } else {
606 char *command;
607 int cmdlen, cmdsize;
608 cmdlen = cmdsize = 0;
609 command = NULL;
610
611 while (argc) {
612 while (*p) {
613 if (cmdlen >= cmdsize) {
614 cmdsize = cmdlen + 512;
615 command = sresize(command, cmdsize, char);
616 }
617 command[cmdlen++]=*p++;
618 }
619 if (cmdlen >= cmdsize) {
620 cmdsize = cmdlen + 512;
621 command = sresize(command, cmdsize, char);
622 }
623 command[cmdlen++]=' '; /* always add trailing space */
624 if (--argc) p = *++argv;
625 }
626 if (cmdlen) command[--cmdlen]='\0';
627 /* change trailing blank to NUL */
628 cfg.remote_cmd_ptr = command;
629 cfg.remote_cmd_ptr2 = NULL;
630 cfg.nopty = TRUE; /* command => no terminal */
631
632 break; /* done with cmdline */
633 }
634 }
635 }
636
637 if (errors)
638 return 1;
639
640 if (!*cfg.host) {
641 usage();
642 }
643
644 /*
645 * Trim leading whitespace off the hostname if it's there.
646 */
647 {
648 int space = strspn(cfg.host, " \t");
649 memmove(cfg.host, cfg.host+space, 1+strlen(cfg.host)-space);
650 }
651
652 /* See if host is of the form user@host */
653 if (cfg.host[0] != '\0') {
654 char *atsign = strrchr(cfg.host, '@');
655 /* Make sure we're not overflowing the user field */
656 if (atsign) {
657 if (atsign - cfg.host < sizeof cfg.username) {
658 strncpy(cfg.username, cfg.host, atsign - cfg.host);
659 cfg.username[atsign - cfg.host] = '\0';
660 }
661 memmove(cfg.host, atsign + 1, 1 + strlen(atsign + 1));
662 }
663 }
664
665 /*
666 * Perform command-line overrides on session configuration.
667 */
668 cmdline_run_saved(&cfg);
669
670 /*
671 * Apply subsystem status.
672 */
673 if (use_subsystem)
674 cfg.ssh_subsys = TRUE;
675
676 /*
677 * Trim a colon suffix off the hostname if it's there.
678 */
679 cfg.host[strcspn(cfg.host, ":")] = '\0';
680
681 /*
682 * Remove any remaining whitespace from the hostname.
683 */
684 {
685 int p1 = 0, p2 = 0;
686 while (cfg.host[p2] != '\0') {
687 if (cfg.host[p2] != ' ' && cfg.host[p2] != '\t') {
688 cfg.host[p1] = cfg.host[p2];
689 p1++;
690 }
691 p2++;
692 }
693 cfg.host[p1] = '\0';
694 }
695
696 if (!cfg.remote_cmd_ptr && !*cfg.remote_cmd)
697 flags |= FLAG_INTERACTIVE;
698
699 /*
700 * Select protocol. This is farmed out into a table in a
701 * separate file to enable an ssh-free variant.
702 */
703 {
704 int i;
705 back = NULL;
706 for (i = 0; backends[i].backend != NULL; i++)
707 if (backends[i].protocol == cfg.protocol) {
708 back = backends[i].backend;
709 break;
710 }
711 if (back == NULL) {
712 fprintf(stderr,
713 "Internal fault: Unsupported protocol found\n");
714 return 1;
715 }
716 }
717
718 /*
719 * Select port.
720 */
721 if (portnumber != -1)
722 cfg.port = portnumber;
723
724 /*
725 * Set up the pipe we'll use to tell us about SIGWINCH.
726 */
727 if (pipe(signalpipe) < 0) {
728 perror("pipe");
729 exit(1);
730 }
731 putty_signal(SIGWINCH, sigwinch);
732
733 sk_init();
734 uxsel_init();
735
736 /*
737 * Start up the connection.
738 */
739 logctx = log_init(NULL, &cfg);
740 console_provide_logctx(logctx);
741 {
742 const char *error;
743 char *realhost;
744 /* nodelay is only useful if stdin is a terminal device */
745 int nodelay = cfg.tcp_nodelay && isatty(0);
746
747 error = back->init(NULL, &backhandle, &cfg, cfg.host, cfg.port,
748 &realhost, nodelay, cfg.tcp_keepalives);
749 if (error) {
750 fprintf(stderr, "Unable to open connection:\n%s\n", error);
751 return 1;
752 }
753 back->provide_logctx(backhandle, logctx);
754 ldisc = ldisc_create(&cfg, NULL, back, backhandle, NULL);
755 sfree(realhost);
756 }
757 connopen = 1;
758
759 /*
760 * Set up the initial console mode. We don't care if this call
761 * fails, because we know we aren't necessarily running in a
762 * console.
763 */
764 local_tty = (tcgetattr(0, &orig_termios) == 0);
765 atexit(cleanup_termios);
766 ldisc_update(NULL, 1, 1);
767 sending = FALSE;
768 now = GETTICKCOUNT();
769
770 while (1) {
771 fd_set rset, wset, xset;
772 int maxfd;
773 int rwx;
774 int ret;
775
776 FD_ZERO(&rset);
777 FD_ZERO(&wset);
778 FD_ZERO(&xset);
779 maxfd = 0;
780
781 FD_SET_MAX(signalpipe[0], maxfd, rset);
782
783 if (connopen && !sending &&
784 back->socket(backhandle) != NULL &&
785 back->sendok(backhandle) &&
786 back->sendbuffer(backhandle) < MAX_STDIN_BACKLOG) {
787 /* If we're OK to send, then try to read from stdin. */
788 FD_SET_MAX(0, maxfd, rset);
789 }
790
791 if (bufchain_size(&stdout_data) > 0) {
792 /* If we have data for stdout, try to write to stdout. */
793 FD_SET_MAX(1, maxfd, wset);
794 }
795
796 if (bufchain_size(&stderr_data) > 0) {
797 /* If we have data for stderr, try to write to stderr. */
798 FD_SET_MAX(2, maxfd, wset);
799 }
800
801 /* Count the currently active fds. */
802 i = 0;
803 for (fd = first_fd(&fdstate, &rwx); fd >= 0;
804 fd = next_fd(&fdstate, &rwx)) i++;
805
806 /* Expand the fdlist buffer if necessary. */
807 if (i > fdsize) {
808 fdsize = i + 16;
809 fdlist = sresize(fdlist, fdsize, int);
810 }
811
812 /*
813 * Add all currently open fds to the select sets, and store
814 * them in fdlist as well.
815 */
816 fdcount = 0;
817 for (fd = first_fd(&fdstate, &rwx); fd >= 0;
818 fd = next_fd(&fdstate, &rwx)) {
819 fdlist[fdcount++] = fd;
820 if (rwx & 1)
821 FD_SET_MAX(fd, maxfd, rset);
822 if (rwx & 2)
823 FD_SET_MAX(fd, maxfd, wset);
824 if (rwx & 4)
825 FD_SET_MAX(fd, maxfd, xset);
826 }
827
828 do {
829 long next, ticks;
830 struct timeval tv, *ptv;
831
832 if (run_timers(now, &next)) {
833 ticks = next - GETTICKCOUNT();
834 if (ticks < 0) ticks = 0; /* just in case */
835 tv.tv_sec = ticks / 1000;
836 tv.tv_usec = ticks % 1000 * 1000;
837 ptv = &tv;
838 } else {
839 ptv = NULL;
840 }
841 ret = select(maxfd, &rset, &wset, &xset, ptv);
842 if (ret == 0)
843 now = next;
844 else {
845 long newnow = GETTICKCOUNT();
846 /*
847 * Check to see whether the system clock has
848 * changed massively during the select.
849 */
850 if (newnow - now < 0 || newnow - now > next - now) {
851 /*
852 * If so, look at the elapsed time in the
853 * select and use it to compute a new
854 * tickcount_offset.
855 */
856 long othernow = now + tv.tv_sec * 1000 + tv.tv_usec / 1000;
857 /* So we'd like GETTICKCOUNT to have returned othernow,
858 * but instead it return newnow. Hence ... */
859 tickcount_offset += othernow - newnow;
860 now = othernow;
861 } else {
862 now = newnow;
863 }
864 }
865 } while (ret < 0 && errno == EINTR);
866
867 if (ret < 0) {
868 perror("select");
869 exit(1);
870 }
871
872 for (i = 0; i < fdcount; i++) {
873 fd = fdlist[i];
874 /*
875 * We must process exceptional notifications before
876 * ordinary readability ones, or we may go straight
877 * past the urgent marker.
878 */
879 if (FD_ISSET(fd, &xset))
880 select_result(fd, 4);
881 if (FD_ISSET(fd, &rset))
882 select_result(fd, 1);
883 if (FD_ISSET(fd, &wset))
884 select_result(fd, 2);
885 }
886
887 if (FD_ISSET(signalpipe[0], &rset)) {
888 char c[1];
889 struct winsize size;
890 read(signalpipe[0], c, 1); /* ignore its value; it'll be `x' */
891 if (ioctl(0, TIOCGWINSZ, (void *)&size) >= 0)
892 back->size(backhandle, size.ws_col, size.ws_row);
893 }
894
895 if (FD_ISSET(0, &rset)) {
896 char buf[4096];
897 int ret;
898
899 if (connopen && back->socket(backhandle) != NULL) {
900 ret = read(0, buf, sizeof(buf));
901 if (ret < 0) {
902 perror("stdin: read");
903 exit(1);
904 } else if (ret == 0) {
905 back->special(backhandle, TS_EOF);
906 sending = FALSE; /* send nothing further after this */
907 } else {
908 back->send(backhandle, buf, ret);
909 }
910 }
911 }
912
913 if (FD_ISSET(1, &wset)) {
914 try_output(0);
915 }
916
917 if (FD_ISSET(2, &wset)) {
918 try_output(1);
919 }
920
921 if ((!connopen || back->socket(backhandle) == NULL) &&
922 bufchain_size(&stdout_data) == 0 &&
923 bufchain_size(&stderr_data) == 0)
924 break; /* we closed the connection */
925 }
926 exitcode = back->exitcode(backhandle);
927 if (exitcode < 0) {
928 fprintf(stderr, "Remote process exit code unavailable\n");
929 exitcode = 1; /* this is an error condition */
930 }
931 cleanup_exit(exitcode);
932 return exitcode; /* shouldn't happen, but placates gcc */
933 }
Simon Tatham's PuTTY GUI SSH client; import of svn://svn.tartarus.org/sgt/putty