2 This file is part of systemd.
4 Copyright 2010 Lennart Poettering
6 systemd is free software; you can redistribute it and/or modify it
7 under the terms of the GNU Lesser General Public License as published by
8 the Free Software Foundation; either version 2.1 of the License, or
9 (at your option) any later version.
11 systemd is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public License
17 along with systemd; If not, see <http://www.gnu.org/licenses/>.
20 #include <sys/ioctl.h>
21 #include <sys/types.h>
31 #include <linux/tiocl.h>
34 #include "terminal-util.h"
35 #include "time-util.h"
36 #include "process-util.h"
39 #include "path-util.h"
41 static volatile unsigned cached_columns = 0;
42 static volatile unsigned cached_lines = 0;
45 _cleanup_close_ int fd;
47 fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY|O_CLOEXEC);
53 TIOCL_GETKMSGREDIRECT,
57 if (ioctl(fd, TIOCLINUX, tiocl) < 0)
60 vt = tiocl[0] <= 0 ? 1 : tiocl[0];
63 if (ioctl(fd, VT_ACTIVATE, vt) < 0)
69 int read_one_char(FILE *f, char *ret, usec_t t, bool *need_nl) {
70 struct termios old_termios, new_termios;
71 char c, line[LINE_MAX];
76 if (tcgetattr(fileno(f), &old_termios) >= 0) {
77 new_termios = old_termios;
79 new_termios.c_lflag &= ~ICANON;
80 new_termios.c_cc[VMIN] = 1;
81 new_termios.c_cc[VTIME] = 0;
83 if (tcsetattr(fileno(f), TCSADRAIN, &new_termios) >= 0) {
86 if (t != USEC_INFINITY) {
87 if (fd_wait_for_event(fileno(f), POLLIN, t) <= 0) {
88 tcsetattr(fileno(f), TCSADRAIN, &old_termios);
93 k = fread(&c, 1, 1, f);
95 tcsetattr(fileno(f), TCSADRAIN, &old_termios);
101 *need_nl = c != '\n';
108 if (t != USEC_INFINITY) {
109 if (fd_wait_for_event(fileno(f), POLLIN, t) <= 0)
114 if (!fgets(line, sizeof(line), f))
115 return errno ? -errno : -EIO;
119 if (strlen(line) != 1)
129 int ask_char(char *ret, const char *replies, const char *text, ...) {
142 fputs(ANSI_HIGHLIGHT_ON, stdout);
149 fputs(ANSI_HIGHLIGHT_OFF, stdout);
153 r = read_one_char(stdin, &c, USEC_INFINITY, &need_nl);
157 puts("Bad input, please try again.");
168 if (strchr(replies, c)) {
173 puts("Read unexpected character, please try again.");
177 int ask_string(char **ret, const char *text, ...) {
186 fputs(ANSI_HIGHLIGHT_ON, stdout);
193 fputs(ANSI_HIGHLIGHT_OFF, stdout);
198 if (!fgets(line, sizeof(line), stdin))
199 return errno ? -errno : -EIO;
201 if (!endswith(line, "\n"))
220 int reset_terminal_fd(int fd, bool switch_to_text) {
221 struct termios termios;
224 /* Set terminal to some sane defaults */
228 /* We leave locked terminal attributes untouched, so that
229 * Plymouth may set whatever it wants to set, and we don't
230 * interfere with that. */
232 /* Disable exclusive mode, just in case */
235 /* Switch to text mode */
237 ioctl(fd, KDSETMODE, KD_TEXT);
239 /* Enable console unicode mode */
240 ioctl(fd, KDSKBMODE, K_UNICODE);
242 if (tcgetattr(fd, &termios) < 0) {
247 /* We only reset the stuff that matters to the software. How
248 * hardware is set up we don't touch assuming that somebody
249 * else will do that for us */
251 termios.c_iflag &= ~(IGNBRK | BRKINT | ISTRIP | INLCR | IGNCR | IUCLC);
252 termios.c_iflag |= ICRNL | IMAXBEL | IUTF8;
253 termios.c_oflag |= ONLCR;
254 termios.c_cflag |= CREAD;
255 termios.c_lflag = ISIG | ICANON | IEXTEN | ECHO | ECHOE | ECHOK | ECHOCTL | ECHOPRT | ECHOKE;
257 termios.c_cc[VINTR] = 03; /* ^C */
258 termios.c_cc[VQUIT] = 034; /* ^\ */
259 termios.c_cc[VERASE] = 0177;
260 termios.c_cc[VKILL] = 025; /* ^X */
261 termios.c_cc[VEOF] = 04; /* ^D */
262 termios.c_cc[VSTART] = 021; /* ^Q */
263 termios.c_cc[VSTOP] = 023; /* ^S */
264 termios.c_cc[VSUSP] = 032; /* ^Z */
265 termios.c_cc[VLNEXT] = 026; /* ^V */
266 termios.c_cc[VWERASE] = 027; /* ^W */
267 termios.c_cc[VREPRINT] = 022; /* ^R */
268 termios.c_cc[VEOL] = 0;
269 termios.c_cc[VEOL2] = 0;
271 termios.c_cc[VTIME] = 0;
272 termios.c_cc[VMIN] = 1;
274 if (tcsetattr(fd, TCSANOW, &termios) < 0)
278 /* Just in case, flush all crap out */
279 tcflush(fd, TCIOFLUSH);
284 int reset_terminal(const char *name) {
285 _cleanup_close_ int fd = -1;
287 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
291 return reset_terminal_fd(fd, true);
294 int open_terminal(const char *name, int mode) {
299 * If a TTY is in the process of being closed opening it might
300 * cause EIO. This is horribly awful, but unlikely to be
301 * changed in the kernel. Hence we work around this problem by
302 * retrying a couple of times.
304 * https://bugs.launchpad.net/ubuntu/+source/linux/+bug/554172/comments/245
307 assert(!(mode & O_CREAT));
310 fd = open(name, mode, 0);
317 /* Max 1s in total */
321 usleep(50 * USEC_PER_MSEC);
339 int acquire_terminal(
343 bool ignore_tiocstty_eperm,
346 int fd = -1, notify = -1, r = 0, wd = -1;
351 /* We use inotify to be notified when the tty is closed. We
352 * create the watch before checking if we can actually acquire
353 * it, so that we don't lose any event.
355 * Note: strictly speaking this actually watches for the
356 * device being closed, it does *not* really watch whether a
357 * tty loses its controlling process. However, unless some
358 * rogue process uses TIOCNOTTY on /dev/tty *after* closing
359 * its tty otherwise this will not become a problem. As long
360 * as the administrator makes sure not configure any service
361 * on the same tty as an untrusted user this should not be a
362 * problem. (Which he probably should not do anyway.) */
364 if (timeout != USEC_INFINITY)
365 ts = now(CLOCK_MONOTONIC);
367 if (!fail && !force) {
368 notify = inotify_init1(IN_CLOEXEC | (timeout != USEC_INFINITY ? IN_NONBLOCK : 0));
374 wd = inotify_add_watch(notify, name, IN_CLOSE);
382 struct sigaction sa_old, sa_new = {
383 .sa_handler = SIG_IGN,
384 .sa_flags = SA_RESTART,
388 r = flush_fd(notify);
393 /* We pass here O_NOCTTY only so that we can check the return
394 * value TIOCSCTTY and have a reliable way to figure out if we
395 * successfully became the controlling process of the tty */
396 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
400 /* Temporarily ignore SIGHUP, so that we don't get SIGHUP'ed
401 * if we already own the tty. */
402 assert_se(sigaction(SIGHUP, &sa_new, &sa_old) == 0);
404 /* First, try to get the tty */
405 if (ioctl(fd, TIOCSCTTY, force) < 0)
408 assert_se(sigaction(SIGHUP, &sa_old, NULL) == 0);
410 /* Sometimes it makes sense to ignore TIOCSCTTY
411 * returning EPERM, i.e. when very likely we already
412 * are have this controlling terminal. */
413 if (r < 0 && r == -EPERM && ignore_tiocstty_eperm)
416 if (r < 0 && (force || fail || r != -EPERM)) {
428 union inotify_event_buffer buffer;
429 struct inotify_event *e;
432 if (timeout != USEC_INFINITY) {
435 n = now(CLOCK_MONOTONIC);
436 if (ts + timeout < n) {
441 r = fd_wait_for_event(fd, POLLIN, ts + timeout - n);
451 l = read(notify, &buffer, sizeof(buffer));
453 if (errno == EINTR || errno == EAGAIN)
460 FOREACH_INOTIFY_EVENT(e, buffer, l) {
461 if (e->wd != wd || !(e->mask & IN_CLOSE)) {
470 /* We close the tty fd here since if the old session
471 * ended our handle will be dead. It's important that
472 * we do this after sleeping, so that we don't enter
473 * an endless loop. */
479 r = reset_terminal_fd(fd, true);
481 log_warning_errno(r, "Failed to reset terminal: %m");
492 int release_terminal(void) {
493 static const struct sigaction sa_new = {
494 .sa_handler = SIG_IGN,
495 .sa_flags = SA_RESTART,
498 _cleanup_close_ int fd = -1;
499 struct sigaction sa_old;
502 fd = open("/dev/tty", O_RDWR|O_NOCTTY|O_NDELAY|O_CLOEXEC);
506 /* Temporarily ignore SIGHUP, so that we don't get SIGHUP'ed
507 * by our own TIOCNOTTY */
508 assert_se(sigaction(SIGHUP, &sa_new, &sa_old) == 0);
510 if (ioctl(fd, TIOCNOTTY) < 0)
513 assert_se(sigaction(SIGHUP, &sa_old, NULL) == 0);
518 int terminal_vhangup_fd(int fd) {
521 if (ioctl(fd, TIOCVHANGUP) < 0)
527 int terminal_vhangup(const char *name) {
528 _cleanup_close_ int fd;
530 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
534 return terminal_vhangup_fd(fd);
537 int vt_disallocate(const char *name) {
541 /* Deallocate the VT if possible. If not possible
542 * (i.e. because it is the active one), at least clear it
543 * entirely (including the scrollback buffer) */
545 if (!startswith(name, "/dev/"))
548 if (!tty_is_vc(name)) {
549 /* So this is not a VT. I guess we cannot deallocate
550 * it then. But let's at least clear the screen */
552 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
557 "\033[r" /* clear scrolling region */
558 "\033[H" /* move home */
559 "\033[2J", /* clear screen */
566 if (!startswith(name, "/dev/tty"))
569 r = safe_atou(name+8, &u);
576 /* Try to deallocate */
577 fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY|O_CLOEXEC);
581 r = ioctl(fd, VT_DISALLOCATE, u);
590 /* Couldn't deallocate, so let's clear it fully with
592 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
597 "\033[r" /* clear scrolling region */
598 "\033[H" /* move home */
599 "\033[3J", /* clear screen including scrollback, requires Linux 2.6.40 */
606 void warn_melody(void) {
607 _cleanup_close_ int fd = -1;
609 fd = open("/dev/console", O_WRONLY|O_CLOEXEC|O_NOCTTY);
613 /* Yeah, this is synchronous. Kinda sucks. But well... */
615 ioctl(fd, KIOCSOUND, (int)(1193180/440));
616 usleep(125*USEC_PER_MSEC);
618 ioctl(fd, KIOCSOUND, (int)(1193180/220));
619 usleep(125*USEC_PER_MSEC);
621 ioctl(fd, KIOCSOUND, (int)(1193180/220));
622 usleep(125*USEC_PER_MSEC);
624 ioctl(fd, KIOCSOUND, 0);
627 int make_console_stdio(void) {
630 /* Make /dev/console the controlling terminal and stdin/stdout/stderr */
632 fd = acquire_terminal("/dev/console", false, true, true, USEC_INFINITY);
634 return log_error_errno(fd, "Failed to acquire terminal: %m");
638 return log_error_errno(r, "Failed to duplicate terminal fd: %m");
643 int status_vprintf(const char *status, bool ellipse, bool ephemeral, const char *format, va_list ap) {
644 static const char status_indent[] = " "; /* "[" STATUS "] " */
645 _cleanup_free_ char *s = NULL;
646 _cleanup_close_ int fd = -1;
647 struct iovec iovec[6] = {};
649 static bool prev_ephemeral;
653 /* This is independent of logging, as status messages are
654 * optional and go exclusively to the console. */
656 if (vasprintf(&s, format, ap) < 0)
659 fd = open_terminal("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC);
672 sl = status ? sizeof(status_indent)-1 : 0;
678 e = ellipsize(s, emax, 50);
686 IOVEC_SET_STRING(iovec[n++], "\r" ANSI_ERASE_TO_END_OF_LINE);
687 prev_ephemeral = ephemeral;
690 if (!isempty(status)) {
691 IOVEC_SET_STRING(iovec[n++], "[");
692 IOVEC_SET_STRING(iovec[n++], status);
693 IOVEC_SET_STRING(iovec[n++], "] ");
695 IOVEC_SET_STRING(iovec[n++], status_indent);
698 IOVEC_SET_STRING(iovec[n++], s);
700 IOVEC_SET_STRING(iovec[n++], "\n");
702 if (writev(fd, iovec, n) < 0)
708 int status_printf(const char *status, bool ellipse, bool ephemeral, const char *format, ...) {
714 va_start(ap, format);
715 r = status_vprintf(status, ellipse, ephemeral, format, ap);
721 bool tty_is_vc(const char *tty) {
724 return vtnr_from_tty(tty) >= 0;
727 bool tty_is_console(const char *tty) {
730 if (startswith(tty, "/dev/"))
733 return streq(tty, "console");
736 int vtnr_from_tty(const char *tty) {
741 if (startswith(tty, "/dev/"))
744 if (!startswith(tty, "tty") )
747 if (tty[3] < '0' || tty[3] > '9')
750 r = safe_atoi(tty+3, &i);
760 char *resolve_dev_console(char **active) {
763 /* Resolve where /dev/console is pointing to, if /sys is actually ours
764 * (i.e. not read-only-mounted which is a sign for container setups) */
766 if (path_is_read_only_fs("/sys") > 0)
769 if (read_one_line_file("/sys/class/tty/console/active", active) < 0)
772 /* If multiple log outputs are configured the last one is what
773 * /dev/console points to */
774 tty = strrchr(*active, ' ');
780 if (streq(tty, "tty0")) {
783 /* Get the active VC (e.g. tty1) */
784 if (read_one_line_file("/sys/class/tty/tty0/active", &tmp) >= 0) {
793 bool tty_is_vc_resolve(const char *tty) {
794 _cleanup_free_ char *active = NULL;
798 if (startswith(tty, "/dev/"))
801 if (streq(tty, "console")) {
802 tty = resolve_dev_console(&active);
807 return tty_is_vc(tty);
810 const char *default_term_for_tty(const char *tty) {
813 return tty_is_vc_resolve(tty) ? "TERM=linux" : "TERM=vt220";
816 int fd_columns(int fd) {
817 struct winsize ws = {};
819 if (ioctl(fd, TIOCGWINSZ, &ws) < 0)
828 unsigned columns(void) {
832 if (_likely_(cached_columns > 0))
833 return cached_columns;
836 e = getenv("COLUMNS");
838 (void) safe_atoi(e, &c);
841 c = fd_columns(STDOUT_FILENO);
847 return cached_columns;
850 int fd_lines(int fd) {
851 struct winsize ws = {};
853 if (ioctl(fd, TIOCGWINSZ, &ws) < 0)
862 unsigned lines(void) {
866 if (_likely_(cached_lines > 0))
872 (void) safe_atoi(e, &l);
875 l = fd_lines(STDOUT_FILENO);
884 /* intended to be used as a SIGWINCH sighandler */
885 void columns_lines_cache_reset(int signum) {
891 static int cached_on_tty = -1;
893 if (_unlikely_(cached_on_tty < 0))
894 cached_on_tty = isatty(STDOUT_FILENO) > 0;
896 return cached_on_tty;
899 int make_stdio(int fd) {
904 r = dup2(fd, STDIN_FILENO);
905 s = dup2(fd, STDOUT_FILENO);
906 t = dup2(fd, STDERR_FILENO);
911 if (r < 0 || s < 0 || t < 0)
914 /* Explicitly unset O_CLOEXEC, since if fd was < 3, then
915 * dup2() was a NOP and the bit hence possibly set. */
916 fd_cloexec(STDIN_FILENO, false);
917 fd_cloexec(STDOUT_FILENO, false);
918 fd_cloexec(STDERR_FILENO, false);
923 int make_null_stdio(void) {
926 null_fd = open("/dev/null", O_RDWR|O_NOCTTY);
930 return make_stdio(null_fd);
933 int getttyname_malloc(int fd, char **ret) {
943 r = ttyname_r(fd, path, sizeof(path));
948 p = startswith(path, "/dev/");
949 c = strdup(p ?: path);
966 int getttyname_harder(int fd, char **r) {
970 k = getttyname_malloc(fd, &s);
974 if (streq(s, "tty")) {
976 return get_ctty(0, NULL, r);
983 int get_ctty_devnr(pid_t pid, dev_t *d) {
985 _cleanup_free_ char *line = NULL;
991 p = procfs_file_alloca(pid, "stat");
992 r = read_one_line_file(p, &line);
996 p = strrchr(line, ')');
1006 "%*d " /* session */
1011 if (major(ttynr) == 0 && minor(ttynr) == 0)
1020 int get_ctty(pid_t pid, dev_t *_devnr, char **r) {
1021 char fn[sizeof("/dev/char/")-1 + 2*DECIMAL_STR_MAX(unsigned) + 1 + 1], *b = NULL;
1022 _cleanup_free_ char *s = NULL;
1029 k = get_ctty_devnr(pid, &devnr);
1033 sprintf(fn, "/dev/char/%u:%u", major(devnr), minor(devnr));
1035 k = readlink_malloc(fn, &s);
1041 /* This is an ugly hack */
1042 if (major(devnr) == 136) {
1043 if (asprintf(&b, "pts/%u", minor(devnr)) < 0)
1046 /* Probably something like the ptys which have no
1047 * symlink in /dev/char. Let's return something
1048 * vaguely useful. */
1055 if (startswith(s, "/dev/"))
1057 else if (startswith(s, "../"))