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|O_NONBLOCK);
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 /// UNNEEDED by elogind
131 int ask_char(char *ret, const char *replies, const char *text, ...) {
144 fputs(ANSI_HIGHLIGHT_ON, stdout);
151 fputs(ANSI_HIGHLIGHT_OFF, stdout);
155 r = read_one_char(stdin, &c, USEC_INFINITY, &need_nl);
159 puts("Bad input, please try again.");
170 if (strchr(replies, c)) {
175 puts("Read unexpected character, please try again.");
179 int ask_string(char **ret, const char *text, ...) {
188 fputs(ANSI_HIGHLIGHT_ON, stdout);
195 fputs(ANSI_HIGHLIGHT_OFF, stdout);
200 if (!fgets(line, sizeof(line), stdin))
201 return errno ? -errno : -EIO;
203 if (!endswith(line, "\n"))
223 int reset_terminal_fd(int fd, bool switch_to_text) {
224 struct termios termios;
227 /* Set terminal to some sane defaults */
231 /* We leave locked terminal attributes untouched, so that
232 * Plymouth may set whatever it wants to set, and we don't
233 * interfere with that. */
235 /* Disable exclusive mode, just in case */
236 (void) ioctl(fd, TIOCNXCL);
238 /* Switch to text mode */
240 (void) ioctl(fd, KDSETMODE, KD_TEXT);
242 /* Enable console unicode mode */
243 (void) ioctl(fd, KDSKBMODE, K_UNICODE);
245 if (tcgetattr(fd, &termios) < 0) {
250 /* We only reset the stuff that matters to the software. How
251 * hardware is set up we don't touch assuming that somebody
252 * else will do that for us */
254 termios.c_iflag &= ~(IGNBRK | BRKINT | ISTRIP | INLCR | IGNCR | IUCLC);
255 termios.c_iflag |= ICRNL | IMAXBEL | IUTF8;
256 termios.c_oflag |= ONLCR;
257 termios.c_cflag |= CREAD;
258 termios.c_lflag = ISIG | ICANON | IEXTEN | ECHO | ECHOE | ECHOK | ECHOCTL | ECHOPRT | ECHOKE;
260 termios.c_cc[VINTR] = 03; /* ^C */
261 termios.c_cc[VQUIT] = 034; /* ^\ */
262 termios.c_cc[VERASE] = 0177;
263 termios.c_cc[VKILL] = 025; /* ^X */
264 termios.c_cc[VEOF] = 04; /* ^D */
265 termios.c_cc[VSTART] = 021; /* ^Q */
266 termios.c_cc[VSTOP] = 023; /* ^S */
267 termios.c_cc[VSUSP] = 032; /* ^Z */
268 termios.c_cc[VLNEXT] = 026; /* ^V */
269 termios.c_cc[VWERASE] = 027; /* ^W */
270 termios.c_cc[VREPRINT] = 022; /* ^R */
271 termios.c_cc[VEOL] = 0;
272 termios.c_cc[VEOL2] = 0;
274 termios.c_cc[VTIME] = 0;
275 termios.c_cc[VMIN] = 1;
277 if (tcsetattr(fd, TCSANOW, &termios) < 0)
281 /* Just in case, flush all crap out */
282 (void) tcflush(fd, TCIOFLUSH);
287 int reset_terminal(const char *name) {
288 _cleanup_close_ int fd = -1;
290 /* We open the terminal with O_NONBLOCK here, to ensure we
291 * don't block on carrier if this is a terminal with carrier
294 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
298 return reset_terminal_fd(fd, true);
301 int open_terminal(const char *name, int mode) {
306 * If a TTY is in the process of being closed opening it might
307 * cause EIO. This is horribly awful, but unlikely to be
308 * changed in the kernel. Hence we work around this problem by
309 * retrying a couple of times.
311 * https://bugs.launchpad.net/ubuntu/+source/linux/+bug/554172/comments/245
318 fd = open(name, mode, 0);
325 /* Max 1s in total */
329 usleep(50 * USEC_PER_MSEC);
347 int acquire_terminal(
351 bool ignore_tiocstty_eperm,
354 int fd = -1, notify = -1, r = 0, wd = -1;
359 /* We use inotify to be notified when the tty is closed. We
360 * create the watch before checking if we can actually acquire
361 * it, so that we don't lose any event.
363 * Note: strictly speaking this actually watches for the
364 * device being closed, it does *not* really watch whether a
365 * tty loses its controlling process. However, unless some
366 * rogue process uses TIOCNOTTY on /dev/tty *after* closing
367 * its tty otherwise this will not become a problem. As long
368 * as the administrator makes sure not configure any service
369 * on the same tty as an untrusted user this should not be a
370 * problem. (Which he probably should not do anyway.) */
372 if (timeout != USEC_INFINITY)
373 ts = now(CLOCK_MONOTONIC);
375 if (!fail && !force) {
376 notify = inotify_init1(IN_CLOEXEC | (timeout != USEC_INFINITY ? IN_NONBLOCK : 0));
382 wd = inotify_add_watch(notify, name, IN_CLOSE);
390 struct sigaction sa_old, sa_new = {
391 .sa_handler = SIG_IGN,
392 .sa_flags = SA_RESTART,
396 r = flush_fd(notify);
401 /* We pass here O_NOCTTY only so that we can check the return
402 * value TIOCSCTTY and have a reliable way to figure out if we
403 * successfully became the controlling process of the tty */
404 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
408 /* Temporarily ignore SIGHUP, so that we don't get SIGHUP'ed
409 * if we already own the tty. */
410 assert_se(sigaction(SIGHUP, &sa_new, &sa_old) == 0);
412 /* First, try to get the tty */
413 if (ioctl(fd, TIOCSCTTY, force) < 0)
416 assert_se(sigaction(SIGHUP, &sa_old, NULL) == 0);
418 /* Sometimes it makes sense to ignore TIOCSCTTY
419 * returning EPERM, i.e. when very likely we already
420 * are have this controlling terminal. */
421 if (r < 0 && r == -EPERM && ignore_tiocstty_eperm)
424 if (r < 0 && (force || fail || r != -EPERM))
435 union inotify_event_buffer buffer;
436 struct inotify_event *e;
439 if (timeout != USEC_INFINITY) {
442 n = now(CLOCK_MONOTONIC);
443 if (ts + timeout < n) {
448 r = fd_wait_for_event(fd, POLLIN, ts + timeout - n);
458 l = read(notify, &buffer, sizeof(buffer));
460 if (errno == EINTR || errno == EAGAIN)
467 FOREACH_INOTIFY_EVENT(e, buffer, l) {
468 if (e->wd != wd || !(e->mask & IN_CLOSE)) {
477 /* We close the tty fd here since if the old session
478 * ended our handle will be dead. It's important that
479 * we do this after sleeping, so that we don't enter
480 * an endless loop. */
486 r = reset_terminal_fd(fd, true);
488 log_warning_errno(r, "Failed to reset terminal: %m");
499 /// UNNEEDED by elogind
501 int release_terminal(void) {
502 static const struct sigaction sa_new = {
503 .sa_handler = SIG_IGN,
504 .sa_flags = SA_RESTART,
507 _cleanup_close_ int fd = -1;
508 struct sigaction sa_old;
511 fd = open("/dev/tty", O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
515 /* Temporarily ignore SIGHUP, so that we don't get SIGHUP'ed
516 * by our own TIOCNOTTY */
517 assert_se(sigaction(SIGHUP, &sa_new, &sa_old) == 0);
519 if (ioctl(fd, TIOCNOTTY) < 0)
522 assert_se(sigaction(SIGHUP, &sa_old, NULL) == 0);
528 int terminal_vhangup_fd(int fd) {
531 if (ioctl(fd, TIOCVHANGUP) < 0)
537 int terminal_vhangup(const char *name) {
538 _cleanup_close_ int fd;
540 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
544 return terminal_vhangup_fd(fd);
547 int vt_disallocate(const char *name) {
551 /* Deallocate the VT if possible. If not possible
552 * (i.e. because it is the active one), at least clear it
553 * entirely (including the scrollback buffer) */
555 if (!startswith(name, "/dev/"))
558 if (!tty_is_vc(name)) {
559 /* So this is not a VT. I guess we cannot deallocate
560 * it then. But let's at least clear the screen */
562 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
567 "\033[r" /* clear scrolling region */
568 "\033[H" /* move home */
569 "\033[2J", /* clear screen */
576 if (!startswith(name, "/dev/tty"))
579 r = safe_atou(name+8, &u);
586 /* Try to deallocate */
587 fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
591 r = ioctl(fd, VT_DISALLOCATE, u);
600 /* Couldn't deallocate, so let's clear it fully with
602 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
607 "\033[r" /* clear scrolling region */
608 "\033[H" /* move home */
609 "\033[3J", /* clear screen including scrollback, requires Linux 2.6.40 */
616 void warn_melody(void) {
617 _cleanup_close_ int fd = -1;
619 fd = open("/dev/console", O_WRONLY|O_CLOEXEC|O_NOCTTY);
623 /* Yeah, this is synchronous. Kinda sucks. But well... */
625 (void) ioctl(fd, KIOCSOUND, (int)(1193180/440));
626 usleep(125*USEC_PER_MSEC);
628 (void) ioctl(fd, KIOCSOUND, (int)(1193180/220));
629 usleep(125*USEC_PER_MSEC);
631 (void) ioctl(fd, KIOCSOUND, (int)(1193180/220));
632 usleep(125*USEC_PER_MSEC);
634 (void) ioctl(fd, KIOCSOUND, 0);
637 /// UNNEEDED by elogind
639 int make_console_stdio(void) {
642 /* Make /dev/console the controlling terminal and stdin/stdout/stderr */
644 fd = acquire_terminal("/dev/console", false, true, true, USEC_INFINITY);
646 return log_error_errno(fd, "Failed to acquire terminal: %m");
650 return log_error_errno(r, "Failed to duplicate terminal fd: %m");
656 int status_vprintf(const char *status, bool ellipse, bool ephemeral, const char *format, va_list ap) {
657 static const char status_indent[] = " "; /* "[" STATUS "] " */
658 _cleanup_free_ char *s = NULL;
659 _cleanup_close_ int fd = -1;
660 struct iovec iovec[6] = {};
662 static bool prev_ephemeral;
666 /* This is independent of logging, as status messages are
667 * optional and go exclusively to the console. */
669 if (vasprintf(&s, format, ap) < 0)
672 fd = open_terminal("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC);
685 sl = status ? sizeof(status_indent)-1 : 0;
691 e = ellipsize(s, emax, 50);
699 IOVEC_SET_STRING(iovec[n++], "\r" ANSI_ERASE_TO_END_OF_LINE);
700 prev_ephemeral = ephemeral;
703 if (!isempty(status)) {
704 IOVEC_SET_STRING(iovec[n++], "[");
705 IOVEC_SET_STRING(iovec[n++], status);
706 IOVEC_SET_STRING(iovec[n++], "] ");
708 IOVEC_SET_STRING(iovec[n++], status_indent);
711 IOVEC_SET_STRING(iovec[n++], s);
713 IOVEC_SET_STRING(iovec[n++], "\n");
715 if (writev(fd, iovec, n) < 0)
721 int status_printf(const char *status, bool ellipse, bool ephemeral, const char *format, ...) {
727 va_start(ap, format);
728 r = status_vprintf(status, ellipse, ephemeral, format, ap);
734 bool tty_is_vc(const char *tty) {
737 return vtnr_from_tty(tty) >= 0;
740 bool tty_is_console(const char *tty) {
743 if (startswith(tty, "/dev/"))
746 return streq(tty, "console");
749 int vtnr_from_tty(const char *tty) {
754 if (startswith(tty, "/dev/"))
757 if (!startswith(tty, "tty") )
760 if (tty[3] < '0' || tty[3] > '9')
763 r = safe_atoi(tty+3, &i);
773 char *resolve_dev_console(char **active) {
776 /* Resolve where /dev/console is pointing to, if /sys is actually ours
777 * (i.e. not read-only-mounted which is a sign for container setups) */
779 if (path_is_read_only_fs("/sys") > 0)
782 if (read_one_line_file("/sys/class/tty/console/active", active) < 0)
785 /* If multiple log outputs are configured the last one is what
786 * /dev/console points to */
787 tty = strrchr(*active, ' ');
793 if (streq(tty, "tty0")) {
796 /* Get the active VC (e.g. tty1) */
797 if (read_one_line_file("/sys/class/tty/tty0/active", &tmp) >= 0) {
806 bool tty_is_vc_resolve(const char *tty) {
807 _cleanup_free_ char *active = NULL;
811 if (startswith(tty, "/dev/"))
814 if (streq(tty, "console")) {
815 tty = resolve_dev_console(&active);
820 return tty_is_vc(tty);
823 /// UNNEEDED by elogind
825 const char *default_term_for_tty(const char *tty) {
828 return tty_is_vc_resolve(tty) ? "TERM=linux" : "TERM=vt220";
832 int fd_columns(int fd) {
833 struct winsize ws = {};
835 if (ioctl(fd, TIOCGWINSZ, &ws) < 0)
844 unsigned columns(void) {
848 if (_likely_(cached_columns > 0))
849 return cached_columns;
852 e = getenv("COLUMNS");
854 (void) safe_atoi(e, &c);
857 c = fd_columns(STDOUT_FILENO);
863 return cached_columns;
866 int fd_lines(int fd) {
867 struct winsize ws = {};
869 if (ioctl(fd, TIOCGWINSZ, &ws) < 0)
878 unsigned lines(void) {
882 if (_likely_(cached_lines > 0))
888 (void) safe_atoi(e, &l);
891 l = fd_lines(STDOUT_FILENO);
900 /* intended to be used as a SIGWINCH sighandler */
901 /// UNNEEDED by elogind
903 void columns_lines_cache_reset(int signum) {
910 static int cached_on_tty = -1;
912 if (_unlikely_(cached_on_tty < 0))
913 cached_on_tty = isatty(STDOUT_FILENO) > 0;
915 return cached_on_tty;
918 int make_stdio(int fd) {
923 r = dup2(fd, STDIN_FILENO);
924 s = dup2(fd, STDOUT_FILENO);
925 t = dup2(fd, STDERR_FILENO);
930 if (r < 0 || s < 0 || t < 0)
933 /* Explicitly unset O_CLOEXEC, since if fd was < 3, then
934 * dup2() was a NOP and the bit hence possibly set. */
935 fd_cloexec(STDIN_FILENO, false);
936 fd_cloexec(STDOUT_FILENO, false);
937 fd_cloexec(STDERR_FILENO, false);
942 int make_null_stdio(void) {
945 null_fd = open("/dev/null", O_RDWR|O_NOCTTY);
949 return make_stdio(null_fd);
952 int getttyname_malloc(int fd, char **ret) {
962 r = ttyname_r(fd, path, sizeof(path));
967 p = startswith(path, "/dev/");
968 c = strdup(p ?: path);
985 /// UNNEEDED by elogind
987 int getttyname_harder(int fd, char **r) {
991 k = getttyname_malloc(fd, &s);
995 if (streq(s, "tty")) {
997 return get_ctty(0, NULL, r);
1005 int get_ctty_devnr(pid_t pid, dev_t *d) {
1007 _cleanup_free_ char *line = NULL;
1009 unsigned long ttynr;
1013 p = procfs_file_alloca(pid, "stat");
1014 r = read_one_line_file(p, &line);
1018 p = strrchr(line, ')');
1028 "%*d " /* session */
1033 if (major(ttynr) == 0 && minor(ttynr) == 0)
1042 int get_ctty(pid_t pid, dev_t *_devnr, char **r) {
1043 char fn[sizeof("/dev/char/")-1 + 2*DECIMAL_STR_MAX(unsigned) + 1 + 1], *b = NULL;
1044 _cleanup_free_ char *s = NULL;
1051 k = get_ctty_devnr(pid, &devnr);
1055 sprintf(fn, "/dev/char/%u:%u", major(devnr), minor(devnr));
1057 k = readlink_malloc(fn, &s);
1063 /* This is an ugly hack */
1064 if (major(devnr) == 136) {
1065 if (asprintf(&b, "pts/%u", minor(devnr)) < 0)
1068 /* Probably something like the ptys which have no
1069 * symlink in /dev/char. Let's return something
1070 * vaguely useful. */
1077 if (startswith(s, "/dev/"))
1079 else if (startswith(s, "../"))