2 * Pseudo-tty backend for pterm.
19 #include <sys/types.h>
22 #include <sys/ioctl.h>
39 /* updwtmpx() needs the name of the wtmp file. Try to find it. */
42 #define WTMPX_FILE _PATH_WTMPX
44 #define WTMPX_FILE "/var/log/wtmpx"
50 #define LASTLOG_FILE _PATH_LASTLOG
52 #define LASTLOG_FILE "/var/log/lastlog"
57 * Set up a default for vaguely sane systems. The idea is that if
58 * OMIT_UTMP is not defined, then at least one of the symbols which
59 * enable particular forms of utmp processing should be, if only so
60 * that a link error can warn you that you should have defined
61 * OMIT_UTMP if you didn't want any. Currently HAVE_PUTUTLINE is
62 * the only such symbol.
65 #if !defined HAVE_PUTUTLINE
66 #define HAVE_PUTUTLINE
70 typedef struct pty_tag *Pty;
73 * The pty_signal_pipe, along with the SIGCHLD handler, must be
74 * process-global rather than session-specific.
76 static int pty_signal_pipe[2] = { -1, -1 }; /* obviously bogus initial val */
80 int master_fd, slave_fd;
82 char name[FILENAME_MAX];
84 int term_width, term_height;
85 int child_dead, finished;
91 * We store our pty backends in a tree sorted by master fd, so that
92 * when we get an uxsel notification we know which backend instance
93 * is the owner of the pty that caused it.
95 static int pty_compare_by_fd(void *av, void *bv)
100 if (a->master_fd < b->master_fd)
102 else if (a->master_fd > b->master_fd)
107 static int pty_find_by_fd(void *av, void *bv)
112 if (a < b->master_fd)
114 else if (a > b->master_fd)
119 static tree234 *ptys_by_fd = NULL;
122 * We also have a tree sorted by child pid, so that when we wait()
123 * in response to the signal we know which backend instance is the
124 * owner of the process that caused the signal.
126 static int pty_compare_by_pid(void *av, void *bv)
131 if (a->child_pid < b->child_pid)
133 else if (a->child_pid > b->child_pid)
138 static int pty_find_by_pid(void *av, void *bv)
140 pid_t a = *(pid_t *)av;
143 if (a < b->child_pid)
145 else if (a > b->child_pid)
150 static tree234 *ptys_by_pid = NULL;
153 * If we are using pty_pre_init(), it will need to have already
154 * allocated a pty structure, which we must then return from
155 * pty_init() rather than allocating a new one. Here we store that
156 * structure between allocation and use.
158 * Note that although most of this module is entirely capable of
159 * handling multiple ptys in a single process, pty_pre_init() is
160 * fundamentally _dependent_ on there being at most one pty per
161 * process, so the normal static-data constraints don't apply.
163 * Likewise, since utmp is only used via pty_pre_init, it too must
164 * be single-instance, so we can declare utmp-related variables
167 static Pty single_pty = NULL;
170 static pid_t pty_utmp_helper_pid = -1;
171 static int pty_utmp_helper_pipe = -1;
172 static int pty_stamped_utmp;
173 static struct utmpx utmp_entry;
177 * pty_argv is a grievous hack to allow a proper argv to be passed
178 * through from the Unix command line. Again, it doesn't really
179 * make sense outside a one-pty-per-process setup.
183 static void pty_close(Pty pty);
184 static void pty_try_write(Pty pty);
187 static void setup_utmp(char *ttyname, char *location)
190 struct lastlog lastlog_entry;
196 pw = getpwuid(getuid());
197 memset(&utmp_entry, 0, sizeof(utmp_entry));
198 utmp_entry.ut_type = USER_PROCESS;
199 utmp_entry.ut_pid = getpid();
200 strncpy(utmp_entry.ut_line, ttyname+5, lenof(utmp_entry.ut_line));
201 strncpy(utmp_entry.ut_id, ttyname+8, lenof(utmp_entry.ut_id));
202 strncpy(utmp_entry.ut_user, pw->pw_name, lenof(utmp_entry.ut_user));
203 strncpy(utmp_entry.ut_host, location, lenof(utmp_entry.ut_host));
205 * Apparently there are some architectures where (struct
206 * utmpx).ut_tv is not essentially struct timeval (e.g. Linux
207 * amd64). Hence the temporary.
209 gettimeofday(&tv, NULL);
210 utmp_entry.ut_tv.tv_sec = tv.tv_sec;
211 utmp_entry.ut_tv.tv_usec = tv.tv_usec;
214 pututxline(&utmp_entry);
217 updwtmpx(WTMPX_FILE, &utmp_entry);
220 memset(&lastlog_entry, 0, sizeof(lastlog_entry));
221 strncpy(lastlog_entry.ll_line, ttyname+5, lenof(lastlog_entry.ll_line));
222 strncpy(lastlog_entry.ll_host, location, lenof(lastlog_entry.ll_host));
223 time(&lastlog_entry.ll_time);
224 if ((lastlog = fopen(LASTLOG_FILE, "r+")) != NULL) {
225 fseek(lastlog, sizeof(lastlog_entry) * getuid(), SEEK_SET);
226 fwrite(&lastlog_entry, 1, sizeof(lastlog_entry), lastlog);
231 pty_stamped_utmp = 1;
235 static void cleanup_utmp(void)
239 if (!pty_stamped_utmp)
242 utmp_entry.ut_type = DEAD_PROCESS;
243 memset(utmp_entry.ut_user, 0, lenof(utmp_entry.ut_user));
244 gettimeofday(&tv, NULL);
245 utmp_entry.ut_tv.tv_sec = tv.tv_sec;
246 utmp_entry.ut_tv.tv_usec = tv.tv_usec;
248 updwtmpx(WTMPX_FILE, &utmp_entry);
250 memset(utmp_entry.ut_line, 0, lenof(utmp_entry.ut_line));
251 utmp_entry.ut_tv.tv_sec = 0;
252 utmp_entry.ut_tv.tv_usec = 0;
255 pututxline(&utmp_entry);
258 pty_stamped_utmp = 0; /* ensure we never double-cleanup */
262 #ifndef NO_PTY_PRE_INIT
263 static void sigchld_handler(int signum)
265 if (write(pty_signal_pipe[1], "x", 1) <= 0)
266 /* not much we can do about it */;
271 static void fatal_sig_handler(int signum)
273 putty_signal(signum, SIG_DFL);
279 static int pty_open_slave(Pty pty)
281 if (pty->slave_fd < 0) {
282 pty->slave_fd = open(pty->name, O_RDWR);
283 cloexec(pty->slave_fd);
286 return pty->slave_fd;
289 static void pty_open_master(Pty pty)
292 const char chars1[] = "pqrstuvwxyz";
293 const char chars2[] = "0123456789abcdef";
295 char master_name[20];
298 for (p1 = chars1; *p1; p1++)
299 for (p2 = chars2; *p2; p2++) {
300 sprintf(master_name, "/dev/pty%c%c", *p1, *p2);
301 pty->master_fd = open(master_name, O_RDWR);
302 if (pty->master_fd >= 0) {
303 if (geteuid() == 0 ||
304 access(master_name, R_OK | W_OK) == 0) {
306 * We must also check at this point that we are
307 * able to open the slave side of the pty. We
308 * wouldn't want to allocate the wrong master,
309 * get all the way down to forking, and _then_
310 * find we're unable to open the slave.
312 strcpy(pty->name, master_name);
313 pty->name[5] = 't'; /* /dev/ptyXX -> /dev/ttyXX */
315 cloexec(pty->master_fd);
317 if (pty_open_slave(pty) >= 0 &&
318 access(pty->name, R_OK | W_OK) == 0)
320 if (pty->slave_fd > 0)
321 close(pty->slave_fd);
324 close(pty->master_fd);
328 /* If we get here, we couldn't get a tty at all. */
329 fprintf(stderr, "pterm: unable to open a pseudo-terminal device\n");
334 /* We need to chown/chmod the /dev/ttyXX device. */
335 gp = getgrnam("tty");
336 chown(pty->name, getuid(), gp ? gp->gr_gid : -1);
337 chmod(pty->name, 0600);
340 const int flags = O_RDWR
346 #ifdef HAVE_POSIX_OPENPT
347 #ifdef SET_NONBLOCK_VIA_OPENPT
349 * OS X, as of 10.10 at least, doesn't permit me to set O_NONBLOCK
350 * on pty master fds via the usual fcntl mechanism. Fortunately,
351 * it does let me work around this by adding O_NONBLOCK to the
352 * posix_openpt flags parameter, which isn't a documented use of
353 * the API but seems to work. So we'll do that for now.
355 pty->master_fd = posix_openpt(flags | O_NONBLOCK);
357 pty->master_fd = posix_openpt(flags);
360 if (pty->master_fd < 0) {
361 perror("posix_openpt");
365 pty->master_fd = open("/dev/ptmx", flags);
367 if (pty->master_fd < 0) {
368 perror("/dev/ptmx: open");
373 if (grantpt(pty->master_fd) < 0) {
378 if (unlockpt(pty->master_fd) < 0) {
383 cloexec(pty->master_fd);
385 pty->name[FILENAME_MAX-1] = '\0';
386 strncpy(pty->name, ptsname(pty->master_fd), FILENAME_MAX-1);
389 #ifndef SET_NONBLOCK_VIA_OPENPT
390 nonblock(pty->master_fd);
394 ptys_by_fd = newtree234(pty_compare_by_fd);
395 add234(ptys_by_fd, pty);
399 * Pre-initialisation. This is here to get around the fact that GTK
400 * doesn't like being run in setuid/setgid programs (probably
401 * sensibly). So before we initialise GTK - and therefore before we
402 * even process the command line - we check to see if we're running
403 * set[ug]id. If so, we open our pty master _now_, chown it as
404 * necessary, and drop privileges. We can always close it again
405 * later. If we're potentially going to be doing utmp as well, we
406 * also fork off a utmp helper process and communicate with it by
407 * means of a pipe; the utmp helper will keep privileges in order
408 * to clean up utmp when we exit (i.e. when its end of our pipe
411 void pty_pre_init(void)
413 #ifndef NO_PTY_PRE_INIT
422 pty = single_pty = snew(struct pty_tag);
424 bufchain_init(&pty->output_data);
426 /* set the child signal handler straight away; it needs to be set
427 * before we ever fork. */
428 putty_signal(SIGCHLD, sigchld_handler);
429 pty->master_fd = pty->slave_fd = -1;
431 pty_stamped_utmp = FALSE;
434 if (geteuid() != getuid() || getegid() != getgid()) {
435 pty_open_master(pty);
439 * Fork off the utmp helper.
441 if (pipe(pipefd) < 0) {
442 perror("pterm: pipe");
449 perror("pterm: fork");
451 } else if (pid == 0) {
452 char display[128], buffer[128];
457 * Now sit here until we receive a display name from the
458 * other end of the pipe, and then stamp utmp. Unstamp utmp
459 * again, and exit, when the pipe closes.
465 ret = read(pipefd[0], buffer, lenof(buffer));
469 } else if (!pty_stamped_utmp) {
470 if (dlen < lenof(display))
471 memcpy(display+dlen, buffer,
472 min(ret, lenof(display)-dlen));
473 if (buffer[ret-1] == '\0') {
475 * Now we have a display name. NUL-terminate
476 * it, and stamp utmp.
478 display[lenof(display)-1] = '\0';
480 * Trap as many fatal signals as we can in the
481 * hope of having the best possible chance to
482 * clean up utmp before termination. We are
483 * unfortunately unprotected against SIGKILL,
486 putty_signal(SIGHUP, fatal_sig_handler);
487 putty_signal(SIGINT, fatal_sig_handler);
488 putty_signal(SIGQUIT, fatal_sig_handler);
489 putty_signal(SIGILL, fatal_sig_handler);
490 putty_signal(SIGABRT, fatal_sig_handler);
491 putty_signal(SIGFPE, fatal_sig_handler);
492 putty_signal(SIGPIPE, fatal_sig_handler);
493 putty_signal(SIGALRM, fatal_sig_handler);
494 putty_signal(SIGTERM, fatal_sig_handler);
495 putty_signal(SIGSEGV, fatal_sig_handler);
496 putty_signal(SIGUSR1, fatal_sig_handler);
497 putty_signal(SIGUSR2, fatal_sig_handler);
499 putty_signal(SIGBUS, fatal_sig_handler);
502 putty_signal(SIGPOLL, fatal_sig_handler);
505 putty_signal(SIGPROF, fatal_sig_handler);
508 putty_signal(SIGSYS, fatal_sig_handler);
511 putty_signal(SIGTRAP, fatal_sig_handler);
514 putty_signal(SIGVTALRM, fatal_sig_handler);
517 putty_signal(SIGXCPU, fatal_sig_handler);
520 putty_signal(SIGXFSZ, fatal_sig_handler);
523 putty_signal(SIGIO, fatal_sig_handler);
525 setup_utmp(pty->name, display);
531 pty_utmp_helper_pid = pid;
532 pty_utmp_helper_pipe = pipefd[1];
539 #ifndef HAVE_NO_SETRESUID
540 int gid = getgid(), uid = getuid();
541 int setresgid(gid_t, gid_t, gid_t);
542 int setresuid(uid_t, uid_t, uid_t);
543 if (setresgid(gid, gid, gid) < 0) {
547 if (setresuid(uid, uid, uid) < 0) {
552 if (setgid(getgid()) < 0) {
556 if (setuid(getuid()) < 0) {
563 #endif /* NO_PTY_PRE_INIT */
567 int pty_real_select_result(Pty pty, int event, int status)
571 int finished = FALSE;
575 * We've been called because our child process did
576 * something. `status' tells us what.
578 if ((WIFEXITED(status) || WIFSIGNALED(status))) {
580 * The primary child process died. We could keep
581 * the terminal open for remaining subprocesses to
582 * output to, but conventional wisdom seems to feel
583 * that that's the Wrong Thing for an xterm-alike,
584 * so we bail out now (though we don't necessarily
585 * _close_ the window, depending on the state of
586 * Close On Exit). This would be easy enough to
587 * change or make configurable if necessary.
589 pty->exit_code = status;
590 pty->child_dead = TRUE;
591 del234(ptys_by_pid, pty);
597 ret = read(pty->master_fd, buf, sizeof(buf));
600 * Clean termination condition is that either ret == 0, or ret
601 * < 0 and errno == EIO. Not sure why the latter, but it seems
604 if (ret == 0 || (ret < 0 && errno == EIO)) {
606 * We assume a clean exit if the pty has closed but the
607 * actual child process hasn't. The only way I can
608 * imagine this happening is if it detaches itself from
609 * the pty and goes daemonic - in which case the
610 * expected usage model would precisely _not_ be for
611 * the pterm window to hang around!
614 if (!pty->child_dead)
616 } else if (ret < 0) {
617 perror("read pty master");
619 } else if (ret > 0) {
620 from_backend(pty->frontend, 0, buf, ret);
622 } else if (event == 2) {
624 * Attempt to send data down the pty.
630 if (finished && !pty->finished) {
633 uxsel_del(pty->master_fd);
637 pty->finished = TRUE;
640 * This is a slight layering-violation sort of hack: only
641 * if we're not closing on exit (COE is set to Never, or to
642 * Only On Clean and it wasn't a clean exit) do we output a
643 * `terminated' message.
645 close_on_exit = conf_get_int(pty->conf, CONF_close_on_exit);
646 if (close_on_exit == FORCE_OFF ||
647 (close_on_exit == AUTO && pty->exit_code != 0)) {
650 if (WIFEXITED(pty->exit_code))
651 sprintf(message, "\r\n[pterm: process terminated with exit"
652 " code %d]\r\n", WEXITSTATUS(pty->exit_code));
653 else if (WIFSIGNALED(pty->exit_code))
654 #ifdef HAVE_NO_STRSIGNAL
655 sprintf(message, "\r\n[pterm: process terminated on signal"
656 " %d]\r\n", WTERMSIG(pty->exit_code));
658 sprintf(message, "\r\n[pterm: process terminated on signal"
659 " %d (%.400s)]\r\n", WTERMSIG(pty->exit_code),
660 strsignal(WTERMSIG(pty->exit_code)));
662 from_backend(pty->frontend, 0, message, strlen(message));
665 notify_remote_exit(pty->frontend);
671 int pty_select_result(int fd, int event)
676 if (fd == pty_signal_pipe[0]) {
681 if (read(pty_signal_pipe[0], c, 1) <= 0)
683 /* ignore its value; it'll be `x' */
686 pid = waitpid(-1, &status, WNOHANG);
688 pty = find234(ptys_by_pid, &pid, pty_find_by_pid);
691 ret = ret && pty_real_select_result(pty, -1, status);
694 pty = find234(ptys_by_fd, &fd, pty_find_by_fd);
697 ret = ret && pty_real_select_result(pty, event, 0);
703 static void pty_uxsel_setup(Pty pty)
707 rwx = 1; /* always want to read from pty */
708 if (bufchain_size(&pty->output_data))
709 rwx |= 2; /* might also want to write to it */
710 uxsel_set(pty->master_fd, rwx, pty_select_result);
713 * In principle this only needs calling once for all pty
714 * backend instances, but it's simplest just to call it every
715 * time; uxsel won't mind.
717 uxsel_set(pty_signal_pipe[0], 1, pty_select_result);
721 * Called to set up the pty.
723 * Returns an error message, or NULL on success.
725 * Also places the canonical host name into `realhost'. It must be
726 * freed by the caller.
728 static const char *pty_init(void *frontend, void **backend_handle, Conf *conf,
729 const char *host, int port, char **realhost,
730 int nodelay, int keepalive)
734 #ifndef NOT_X_WINDOWS /* for Mac OS X native compilation */
741 assert(pty->conf == NULL);
743 pty = snew(struct pty_tag);
744 pty->master_fd = pty->slave_fd = -1;
746 pty_stamped_utmp = FALSE;
750 pty->frontend = frontend;
751 *backend_handle = NULL; /* we can't sensibly use this, sadly */
753 pty->conf = conf_copy(conf);
754 pty->term_width = conf_get_int(conf, CONF_width);
755 pty->term_height = conf_get_int(conf, CONF_height);
757 if (pty->master_fd < 0)
758 pty_open_master(pty);
761 * Set the backspace character to be whichever of ^H and ^? is
762 * specified by bksp_is_delete.
765 struct termios attrs;
766 tcgetattr(pty->master_fd, &attrs);
767 attrs.c_cc[VERASE] = conf_get_int(conf, CONF_bksp_is_delete)
769 tcsetattr(pty->master_fd, TCSANOW, &attrs);
774 * Stamp utmp (that is, tell the utmp helper process to do so),
777 if (pty_utmp_helper_pipe >= 0) { /* if it's < 0, we can't anyway */
778 if (!conf_get_int(conf, CONF_stamp_utmp)) {
779 close(pty_utmp_helper_pipe); /* just let the child process die */
780 pty_utmp_helper_pipe = -1;
782 const char *location = get_x_display(pty->frontend);
783 int len = strlen(location)+1, pos = 0; /* +1 to include NUL */
785 int ret = write(pty_utmp_helper_pipe, location+pos, len - pos);
787 perror("pterm: writing to utmp helper process");
788 close(pty_utmp_helper_pipe); /* arrgh, just give up */
789 pty_utmp_helper_pipe = -1;
798 #ifndef NOT_X_WINDOWS /* for Mac OS X native compilation */
799 windowid = get_windowid(pty->frontend);
803 * Fork and execute the command.
816 slavefd = pty_open_slave(pty);
818 perror("slave pty: open");
822 close(pty->master_fd);
830 ioctl(0, TIOCSCTTY, 1);
836 int ptyfd = open(pty->name, O_WRONLY, 0);
842 char *term_env_var = dupprintf("TERM=%s",
843 conf_get_str(conf, CONF_termtype));
844 putenv(term_env_var);
845 /* We mustn't free term_env_var, as putenv links it into the
846 * environment in place.
849 #ifndef NOT_X_WINDOWS /* for Mac OS X native compilation */
851 char *windowid_env_var = dupprintf("WINDOWID=%ld", windowid);
852 putenv(windowid_env_var);
853 /* We mustn't free windowid_env_var, as putenv links it into the
854 * environment in place.
859 * In case we were invoked with a --display argument that
860 * doesn't match DISPLAY in our actual environment, we
861 * should set DISPLAY for processes running inside the
862 * terminal to match the display the terminal itself is
865 const char *x_display = get_x_display(pty->frontend);
866 char *x_display_env_var = dupprintf("DISPLAY=%s", x_display);
867 putenv(x_display_env_var);
868 /* As above, we don't free this. */
874 for (val = conf_get_str_strs(conf, CONF_environmt, NULL, &key);
876 val = conf_get_str_strs(conf, CONF_environmt, key, &key)) {
877 char *varval = dupcat(key, "=", val, NULL);
880 * We must not free varval, since putenv links it
881 * into the environment _in place_. Weird, but
882 * there we go. Memory usage will be rationalised
883 * as soon as we exec anyway.
889 * SIGINT, SIGQUIT and SIGPIPE may have been set to ignored by
890 * our parent, particularly by things like sh -c 'pterm &' and
891 * some window or session managers. SIGCHLD, meanwhile, was
892 * blocked during pt_main() startup. Reverse all this for our
895 putty_signal(SIGINT, SIG_DFL);
896 putty_signal(SIGQUIT, SIG_DFL);
897 putty_signal(SIGPIPE, SIG_DFL);
898 block_signal(SIGCHLD, 0);
901 * Exec the exact argument list we were given.
903 execvp(pty_argv[0], pty_argv);
905 * If that fails, and if we had exactly one argument, pass
906 * that argument to $SHELL -c.
908 * This arranges that we can _either_ follow 'pterm -e'
909 * with a list of argv elements to be fed directly to
910 * exec, _or_ with a single argument containing a command
911 * to be parsed by a shell (but, in cases of doubt, the
912 * former is more reliable).
914 * A quick survey of other terminal emulators' -e options
915 * (as of Debian squeeze) suggests that:
917 * - xterm supports both modes, more or less like this
918 * - gnome-terminal will only accept a one-string shell command
919 * - Eterm, kterm and rxvt will only accept a list of
920 * argv elements (as did older versions of pterm).
922 * It therefore seems important to support both usage
923 * modes in order to be a drop-in replacement for either
924 * xterm or gnome-terminal, and hence for anyone's
925 * plausible uses of the Debian-style alias
926 * 'x-terminal-emulator'...
928 if (pty_argv[1] == NULL) {
929 char *shell = getenv("SHELL");
931 execl(shell, shell, "-c", pty_argv[0], (void *)NULL);
934 char *shell = getenv("SHELL");
936 if (conf_get_int(conf, CONF_login_shell)) {
937 char *p = strrchr(shell, '/');
938 shellname = snewn(2+strlen(shell), char);
940 sprintf(shellname, "-%s", p);
943 execl(getenv("SHELL"), shellname, (void *)NULL);
947 * If we're here, exec has gone badly foom.
952 pty->child_pid = pid;
953 pty->child_dead = FALSE;
954 pty->finished = FALSE;
955 if (pty->slave_fd > 0)
956 close(pty->slave_fd);
958 ptys_by_pid = newtree234(pty_compare_by_pid);
959 add234(ptys_by_pid, pty);
962 if (pty_signal_pipe[0] < 0) {
963 if (pipe(pty_signal_pipe) < 0) {
967 cloexec(pty_signal_pipe[0]);
968 cloexec(pty_signal_pipe[1]);
970 pty_uxsel_setup(pty);
972 *backend_handle = pty;
974 *realhost = dupstr("");
979 static void pty_reconfig(void *handle, Conf *conf)
981 Pty pty = (Pty)handle;
983 * We don't have much need to reconfigure this backend, but
984 * unfortunately we do need to pick up the setting of Close On
985 * Exit so we know whether to give a `terminated' message.
987 conf_copy_into(pty->conf, conf);
991 * Stub routine (never called in pterm).
993 static void pty_free(void *handle)
995 Pty pty = (Pty)handle;
997 /* Either of these may fail `not found'. That's fine with us. */
998 del234(ptys_by_pid, pty);
999 del234(ptys_by_fd, pty);
1001 conf_free(pty->conf);
1004 if (pty == single_pty) {
1006 * Leave this structure around in case we need to Restart
1014 static void pty_try_write(Pty pty)
1019 assert(pty->master_fd >= 0);
1021 while (bufchain_size(&pty->output_data) > 0) {
1022 bufchain_prefix(&pty->output_data, &data, &len);
1023 ret = write(pty->master_fd, data, len);
1025 if (ret < 0 && (errno == EWOULDBLOCK)) {
1027 * We've sent all we can for the moment.
1032 perror("write pty master");
1035 bufchain_consume(&pty->output_data, ret);
1038 pty_uxsel_setup(pty);
1042 * Called to send data down the pty.
1044 static int pty_send(void *handle, const char *buf, int len)
1046 Pty pty = (Pty)handle;
1048 if (pty->master_fd < 0)
1049 return 0; /* ignore all writes if fd closed */
1051 bufchain_add(&pty->output_data, buf, len);
1054 return bufchain_size(&pty->output_data);
1057 static void pty_close(Pty pty)
1059 if (pty->master_fd >= 0) {
1060 close(pty->master_fd);
1061 pty->master_fd = -1;
1064 if (pty_utmp_helper_pipe >= 0) {
1065 close(pty_utmp_helper_pipe); /* this causes utmp to be cleaned up */
1066 pty_utmp_helper_pipe = -1;
1072 * Called to query the current socket sendability status.
1074 static int pty_sendbuffer(void *handle)
1076 /* Pty pty = (Pty)handle; */
1081 * Called to set the size of the window
1083 static void pty_size(void *handle, int width, int height)
1085 Pty pty = (Pty)handle;
1086 struct winsize size;
1088 pty->term_width = width;
1089 pty->term_height = height;
1091 size.ws_row = (unsigned short)pty->term_height;
1092 size.ws_col = (unsigned short)pty->term_width;
1093 size.ws_xpixel = (unsigned short) pty->term_width *
1094 font_dimension(pty->frontend, 0);
1095 size.ws_ypixel = (unsigned short) pty->term_height *
1096 font_dimension(pty->frontend, 1);
1097 ioctl(pty->master_fd, TIOCSWINSZ, (void *)&size);
1102 * Send special codes.
1104 static void pty_special(void *handle, Telnet_Special code)
1106 /* Pty pty = (Pty)handle; */
1112 * Return a list of the special codes that make sense in this
1115 static const struct telnet_special *pty_get_specials(void *handle)
1117 /* Pty pty = (Pty)handle; */
1119 * Hmm. When I get round to having this actually usable, it
1120 * might be quite nice to have the ability to deliver a few
1121 * well chosen signals to the child process - SIGINT, SIGTERM,
1127 static int pty_connected(void *handle)
1129 /* Pty pty = (Pty)handle; */
1133 static int pty_sendok(void *handle)
1135 /* Pty pty = (Pty)handle; */
1139 static void pty_unthrottle(void *handle, int backlog)
1141 /* Pty pty = (Pty)handle; */
1145 static int pty_ldisc(void *handle, int option)
1147 /* Pty pty = (Pty)handle; */
1148 return 0; /* neither editing nor echoing */
1151 static void pty_provide_ldisc(void *handle, void *ldisc)
1153 /* Pty pty = (Pty)handle; */
1154 /* This is a stub. */
1157 static void pty_provide_logctx(void *handle, void *logctx)
1159 /* Pty pty = (Pty)handle; */
1160 /* This is a stub. */
1163 static int pty_exitcode(void *handle)
1165 Pty pty = (Pty)handle;
1167 return -1; /* not dead yet */
1169 return pty->exit_code;
1172 static int pty_cfg_info(void *handle)
1174 /* Pty pty = (Pty)handle; */
1178 Backend pty_backend = {