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 /// 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 */
238 /* Switch to text mode */
240 ioctl(fd, KDSETMODE, KD_TEXT);
242 /* Enable console unicode mode */
243 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 tcflush(fd, TCIOFLUSH);
287 int reset_terminal(const char *name) {
288 _cleanup_close_ int fd = -1;
290 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
294 return reset_terminal_fd(fd, true);
297 int open_terminal(const char *name, int mode) {
302 * If a TTY is in the process of being closed opening it might
303 * cause EIO. This is horribly awful, but unlikely to be
304 * changed in the kernel. Hence we work around this problem by
305 * retrying a couple of times.
307 * https://bugs.launchpad.net/ubuntu/+source/linux/+bug/554172/comments/245
310 assert(!(mode & O_CREAT));
313 fd = open(name, mode, 0);
320 /* Max 1s in total */
324 usleep(50 * USEC_PER_MSEC);
342 int acquire_terminal(
346 bool ignore_tiocstty_eperm,
349 int fd = -1, notify = -1, r = 0, wd = -1;
354 /* We use inotify to be notified when the tty is closed. We
355 * create the watch before checking if we can actually acquire
356 * it, so that we don't lose any event.
358 * Note: strictly speaking this actually watches for the
359 * device being closed, it does *not* really watch whether a
360 * tty loses its controlling process. However, unless some
361 * rogue process uses TIOCNOTTY on /dev/tty *after* closing
362 * its tty otherwise this will not become a problem. As long
363 * as the administrator makes sure not configure any service
364 * on the same tty as an untrusted user this should not be a
365 * problem. (Which he probably should not do anyway.) */
367 if (timeout != USEC_INFINITY)
368 ts = now(CLOCK_MONOTONIC);
370 if (!fail && !force) {
371 notify = inotify_init1(IN_CLOEXEC | (timeout != USEC_INFINITY ? IN_NONBLOCK : 0));
377 wd = inotify_add_watch(notify, name, IN_CLOSE);
385 struct sigaction sa_old, sa_new = {
386 .sa_handler = SIG_IGN,
387 .sa_flags = SA_RESTART,
391 r = flush_fd(notify);
396 /* We pass here O_NOCTTY only so that we can check the return
397 * value TIOCSCTTY and have a reliable way to figure out if we
398 * successfully became the controlling process of the tty */
399 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
403 /* Temporarily ignore SIGHUP, so that we don't get SIGHUP'ed
404 * if we already own the tty. */
405 assert_se(sigaction(SIGHUP, &sa_new, &sa_old) == 0);
407 /* First, try to get the tty */
408 if (ioctl(fd, TIOCSCTTY, force) < 0)
411 assert_se(sigaction(SIGHUP, &sa_old, NULL) == 0);
413 /* Sometimes it makes sense to ignore TIOCSCTTY
414 * returning EPERM, i.e. when very likely we already
415 * are have this controlling terminal. */
416 if (r < 0 && r == -EPERM && ignore_tiocstty_eperm)
419 if (r < 0 && (force || fail || r != -EPERM)) {
431 union inotify_event_buffer buffer;
432 struct inotify_event *e;
435 if (timeout != USEC_INFINITY) {
438 n = now(CLOCK_MONOTONIC);
439 if (ts + timeout < n) {
444 r = fd_wait_for_event(fd, POLLIN, ts + timeout - n);
454 l = read(notify, &buffer, sizeof(buffer));
456 if (errno == EINTR || errno == EAGAIN)
463 FOREACH_INOTIFY_EVENT(e, buffer, l) {
464 if (e->wd != wd || !(e->mask & IN_CLOSE)) {
473 /* We close the tty fd here since if the old session
474 * ended our handle will be dead. It's important that
475 * we do this after sleeping, so that we don't enter
476 * an endless loop. */
482 r = reset_terminal_fd(fd, true);
484 log_warning_errno(r, "Failed to reset terminal: %m");
495 /// UNNEEDED by elogind
497 int release_terminal(void) {
498 static const struct sigaction sa_new = {
499 .sa_handler = SIG_IGN,
500 .sa_flags = SA_RESTART,
503 _cleanup_close_ int fd = -1;
504 struct sigaction sa_old;
507 fd = open("/dev/tty", O_RDWR|O_NOCTTY|O_NDELAY|O_CLOEXEC);
511 /* Temporarily ignore SIGHUP, so that we don't get SIGHUP'ed
512 * by our own TIOCNOTTY */
513 assert_se(sigaction(SIGHUP, &sa_new, &sa_old) == 0);
515 if (ioctl(fd, TIOCNOTTY) < 0)
518 assert_se(sigaction(SIGHUP, &sa_old, NULL) == 0);
524 int terminal_vhangup_fd(int fd) {
527 if (ioctl(fd, TIOCVHANGUP) < 0)
533 int terminal_vhangup(const char *name) {
534 _cleanup_close_ int fd;
536 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
540 return terminal_vhangup_fd(fd);
543 int vt_disallocate(const char *name) {
547 /* Deallocate the VT if possible. If not possible
548 * (i.e. because it is the active one), at least clear it
549 * entirely (including the scrollback buffer) */
551 if (!startswith(name, "/dev/"))
554 if (!tty_is_vc(name)) {
555 /* So this is not a VT. I guess we cannot deallocate
556 * it then. But let's at least clear the screen */
558 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
563 "\033[r" /* clear scrolling region */
564 "\033[H" /* move home */
565 "\033[2J", /* clear screen */
572 if (!startswith(name, "/dev/tty"))
575 r = safe_atou(name+8, &u);
582 /* Try to deallocate */
583 fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY|O_CLOEXEC);
587 r = ioctl(fd, VT_DISALLOCATE, u);
596 /* Couldn't deallocate, so let's clear it fully with
598 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
603 "\033[r" /* clear scrolling region */
604 "\033[H" /* move home */
605 "\033[3J", /* clear screen including scrollback, requires Linux 2.6.40 */
612 void warn_melody(void) {
613 _cleanup_close_ int fd = -1;
615 fd = open("/dev/console", O_WRONLY|O_CLOEXEC|O_NOCTTY);
619 /* Yeah, this is synchronous. Kinda sucks. But well... */
621 ioctl(fd, KIOCSOUND, (int)(1193180/440));
622 usleep(125*USEC_PER_MSEC);
624 ioctl(fd, KIOCSOUND, (int)(1193180/220));
625 usleep(125*USEC_PER_MSEC);
627 ioctl(fd, KIOCSOUND, (int)(1193180/220));
628 usleep(125*USEC_PER_MSEC);
630 ioctl(fd, KIOCSOUND, 0);
633 /// UNNEEDED by elogind
635 int make_console_stdio(void) {
638 /* Make /dev/console the controlling terminal and stdin/stdout/stderr */
640 fd = acquire_terminal("/dev/console", false, true, true, USEC_INFINITY);
642 return log_error_errno(fd, "Failed to acquire terminal: %m");
646 return log_error_errno(r, "Failed to duplicate terminal fd: %m");
652 int status_vprintf(const char *status, bool ellipse, bool ephemeral, const char *format, va_list ap) {
653 static const char status_indent[] = " "; /* "[" STATUS "] " */
654 _cleanup_free_ char *s = NULL;
655 _cleanup_close_ int fd = -1;
656 struct iovec iovec[6] = {};
658 static bool prev_ephemeral;
662 /* This is independent of logging, as status messages are
663 * optional and go exclusively to the console. */
665 if (vasprintf(&s, format, ap) < 0)
668 fd = open_terminal("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC);
681 sl = status ? sizeof(status_indent)-1 : 0;
687 e = ellipsize(s, emax, 50);
695 IOVEC_SET_STRING(iovec[n++], "\r" ANSI_ERASE_TO_END_OF_LINE);
696 prev_ephemeral = ephemeral;
699 if (!isempty(status)) {
700 IOVEC_SET_STRING(iovec[n++], "[");
701 IOVEC_SET_STRING(iovec[n++], status);
702 IOVEC_SET_STRING(iovec[n++], "] ");
704 IOVEC_SET_STRING(iovec[n++], status_indent);
707 IOVEC_SET_STRING(iovec[n++], s);
709 IOVEC_SET_STRING(iovec[n++], "\n");
711 if (writev(fd, iovec, n) < 0)
717 int status_printf(const char *status, bool ellipse, bool ephemeral, const char *format, ...) {
723 va_start(ap, format);
724 r = status_vprintf(status, ellipse, ephemeral, format, ap);
730 bool tty_is_vc(const char *tty) {
733 return vtnr_from_tty(tty) >= 0;
736 bool tty_is_console(const char *tty) {
739 if (startswith(tty, "/dev/"))
742 return streq(tty, "console");
745 int vtnr_from_tty(const char *tty) {
750 if (startswith(tty, "/dev/"))
753 if (!startswith(tty, "tty") )
756 if (tty[3] < '0' || tty[3] > '9')
759 r = safe_atoi(tty+3, &i);
769 char *resolve_dev_console(char **active) {
772 /* Resolve where /dev/console is pointing to, if /sys is actually ours
773 * (i.e. not read-only-mounted which is a sign for container setups) */
775 if (path_is_read_only_fs("/sys") > 0)
778 if (read_one_line_file("/sys/class/tty/console/active", active) < 0)
781 /* If multiple log outputs are configured the last one is what
782 * /dev/console points to */
783 tty = strrchr(*active, ' ');
789 if (streq(tty, "tty0")) {
792 /* Get the active VC (e.g. tty1) */
793 if (read_one_line_file("/sys/class/tty/tty0/active", &tmp) >= 0) {
802 bool tty_is_vc_resolve(const char *tty) {
803 _cleanup_free_ char *active = NULL;
807 if (startswith(tty, "/dev/"))
810 if (streq(tty, "console")) {
811 tty = resolve_dev_console(&active);
816 return tty_is_vc(tty);
819 /// UNNEEDED by elogind
821 const char *default_term_for_tty(const char *tty) {
824 return tty_is_vc_resolve(tty) ? "TERM=linux" : "TERM=vt220";
828 int fd_columns(int fd) {
829 struct winsize ws = {};
831 if (ioctl(fd, TIOCGWINSZ, &ws) < 0)
840 unsigned columns(void) {
844 if (_likely_(cached_columns > 0))
845 return cached_columns;
848 e = getenv("COLUMNS");
850 (void) safe_atoi(e, &c);
853 c = fd_columns(STDOUT_FILENO);
859 return cached_columns;
862 int fd_lines(int fd) {
863 struct winsize ws = {};
865 if (ioctl(fd, TIOCGWINSZ, &ws) < 0)
874 unsigned lines(void) {
878 if (_likely_(cached_lines > 0))
884 (void) safe_atoi(e, &l);
887 l = fd_lines(STDOUT_FILENO);
896 /* intended to be used as a SIGWINCH sighandler */
897 /// UNNEEDED by elogind
899 void columns_lines_cache_reset(int signum) {
906 static int cached_on_tty = -1;
908 if (_unlikely_(cached_on_tty < 0))
909 cached_on_tty = isatty(STDOUT_FILENO) > 0;
911 return cached_on_tty;
914 int make_stdio(int fd) {
919 r = dup2(fd, STDIN_FILENO);
920 s = dup2(fd, STDOUT_FILENO);
921 t = dup2(fd, STDERR_FILENO);
926 if (r < 0 || s < 0 || t < 0)
929 /* Explicitly unset O_CLOEXEC, since if fd was < 3, then
930 * dup2() was a NOP and the bit hence possibly set. */
931 fd_cloexec(STDIN_FILENO, false);
932 fd_cloexec(STDOUT_FILENO, false);
933 fd_cloexec(STDERR_FILENO, false);
938 int make_null_stdio(void) {
941 null_fd = open("/dev/null", O_RDWR|O_NOCTTY);
945 return make_stdio(null_fd);
948 int getttyname_malloc(int fd, char **ret) {
958 r = ttyname_r(fd, path, sizeof(path));
963 p = startswith(path, "/dev/");
964 c = strdup(p ?: path);
981 /// UNNEEDED by elogind
983 int getttyname_harder(int fd, char **r) {
987 k = getttyname_malloc(fd, &s);
991 if (streq(s, "tty")) {
993 return get_ctty(0, NULL, r);
1001 int get_ctty_devnr(pid_t pid, dev_t *d) {
1003 _cleanup_free_ char *line = NULL;
1005 unsigned long ttynr;
1009 p = procfs_file_alloca(pid, "stat");
1010 r = read_one_line_file(p, &line);
1014 p = strrchr(line, ')');
1024 "%*d " /* session */
1029 if (major(ttynr) == 0 && minor(ttynr) == 0)
1038 int get_ctty(pid_t pid, dev_t *_devnr, char **r) {
1039 char fn[sizeof("/dev/char/")-1 + 2*DECIMAL_STR_MAX(unsigned) + 1 + 1], *b = NULL;
1040 _cleanup_free_ char *s = NULL;
1047 k = get_ctty_devnr(pid, &devnr);
1051 sprintf(fn, "/dev/char/%u:%u", major(devnr), minor(devnr));
1053 k = readlink_malloc(fn, &s);
1059 /* This is an ugly hack */
1060 if (major(devnr) == 136) {
1061 if (asprintf(&b, "pts/%u", minor(devnr)) < 0)
1064 /* Probably something like the ptys which have no
1065 * symlink in /dev/char. Let's return something
1066 * vaguely useful. */
1073 if (startswith(s, "/dev/"))
1075 else if (startswith(s, "../"))