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 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 */
233 (void) ioctl(fd
, TIOCNXCL
);
235 /* Switch to text mode */
237 (void) ioctl(fd
, KDSETMODE
, KD_TEXT
);
239 /* Enable console unicode mode */
240 (void) 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 (void) tcflush(fd
, TCIOFLUSH
);
284 int reset_terminal(const char *name
) {
285 _cleanup_close_
int fd
= -1;
287 /* We open the terminal with O_NONBLOCK here, to ensure we
288 * don't block on carrier if this is a terminal with carrier
291 fd
= open_terminal(name
, O_RDWR
|O_NOCTTY
|O_CLOEXEC
|O_NONBLOCK
);
295 return reset_terminal_fd(fd
, true);
298 int open_terminal(const char *name
, int mode
) {
303 * If a TTY is in the process of being closed opening it might
304 * cause EIO. This is horribly awful, but unlikely to be
305 * changed in the kernel. Hence we work around this problem by
306 * retrying a couple of times.
308 * https://bugs.launchpad.net/ubuntu/+source/linux/+bug/554172/comments/245
315 fd
= open(name
, mode
, 0);
322 /* Max 1s in total */
326 usleep(50 * USEC_PER_MSEC
);
344 int acquire_terminal(
348 bool ignore_tiocstty_eperm
,
351 int fd
= -1, notify
= -1, r
= 0, wd
= -1;
356 /* We use inotify to be notified when the tty is closed. We
357 * create the watch before checking if we can actually acquire
358 * it, so that we don't lose any event.
360 * Note: strictly speaking this actually watches for the
361 * device being closed, it does *not* really watch whether a
362 * tty loses its controlling process. However, unless some
363 * rogue process uses TIOCNOTTY on /dev/tty *after* closing
364 * its tty otherwise this will not become a problem. As long
365 * as the administrator makes sure not configure any service
366 * on the same tty as an untrusted user this should not be a
367 * problem. (Which he probably should not do anyway.) */
369 if (timeout
!= USEC_INFINITY
)
370 ts
= now(CLOCK_MONOTONIC
);
372 if (!fail
&& !force
) {
373 notify
= inotify_init1(IN_CLOEXEC
| (timeout
!= USEC_INFINITY
? IN_NONBLOCK
: 0));
379 wd
= inotify_add_watch(notify
, name
, IN_CLOSE
);
387 struct sigaction sa_old
, sa_new
= {
388 .sa_handler
= SIG_IGN
,
389 .sa_flags
= SA_RESTART
,
393 r
= flush_fd(notify
);
398 /* We pass here O_NOCTTY only so that we can check the return
399 * value TIOCSCTTY and have a reliable way to figure out if we
400 * successfully became the controlling process of the tty */
401 fd
= open_terminal(name
, O_RDWR
|O_NOCTTY
|O_CLOEXEC
);
405 /* Temporarily ignore SIGHUP, so that we don't get SIGHUP'ed
406 * if we already own the tty. */
407 assert_se(sigaction(SIGHUP
, &sa_new
, &sa_old
) == 0);
409 /* First, try to get the tty */
410 if (ioctl(fd
, TIOCSCTTY
, force
) < 0)
413 assert_se(sigaction(SIGHUP
, &sa_old
, NULL
) == 0);
415 /* Sometimes it makes sense to ignore TIOCSCTTY
416 * returning EPERM, i.e. when very likely we already
417 * are have this controlling terminal. */
418 if (r
< 0 && r
== -EPERM
&& ignore_tiocstty_eperm
)
421 if (r
< 0 && (force
|| fail
|| r
!= -EPERM
))
432 union inotify_event_buffer buffer
;
433 struct inotify_event
*e
;
436 if (timeout
!= USEC_INFINITY
) {
439 n
= now(CLOCK_MONOTONIC
);
440 if (ts
+ timeout
< n
) {
445 r
= fd_wait_for_event(fd
, POLLIN
, ts
+ timeout
- n
);
455 l
= read(notify
, &buffer
, sizeof(buffer
));
457 if (errno
== EINTR
|| errno
== EAGAIN
)
464 FOREACH_INOTIFY_EVENT(e
, buffer
, l
) {
465 if (e
->wd
!= wd
|| !(e
->mask
& IN_CLOSE
)) {
474 /* We close the tty fd here since if the old session
475 * ended our handle will be dead. It's important that
476 * we do this after sleeping, so that we don't enter
477 * an endless loop. */
483 r
= reset_terminal_fd(fd
, true);
485 log_warning_errno(r
, "Failed to reset terminal: %m");
496 int release_terminal(void) {
497 static const struct sigaction sa_new
= {
498 .sa_handler
= SIG_IGN
,
499 .sa_flags
= SA_RESTART
,
502 _cleanup_close_
int fd
= -1;
503 struct sigaction sa_old
;
506 fd
= open("/dev/tty", O_RDWR
|O_NOCTTY
|O_CLOEXEC
|O_NONBLOCK
);
510 /* Temporarily ignore SIGHUP, so that we don't get SIGHUP'ed
511 * by our own TIOCNOTTY */
512 assert_se(sigaction(SIGHUP
, &sa_new
, &sa_old
) == 0);
514 if (ioctl(fd
, TIOCNOTTY
) < 0)
517 assert_se(sigaction(SIGHUP
, &sa_old
, NULL
) == 0);
522 int terminal_vhangup_fd(int fd
) {
525 if (ioctl(fd
, TIOCVHANGUP
) < 0)
531 int terminal_vhangup(const char *name
) {
532 _cleanup_close_
int fd
;
534 fd
= open_terminal(name
, O_RDWR
|O_NOCTTY
|O_CLOEXEC
|O_NONBLOCK
);
538 return terminal_vhangup_fd(fd
);
541 int vt_disallocate(const char *name
) {
545 /* Deallocate the VT if possible. If not possible
546 * (i.e. because it is the active one), at least clear it
547 * entirely (including the scrollback buffer) */
549 if (!startswith(name
, "/dev/"))
552 if (!tty_is_vc(name
)) {
553 /* So this is not a VT. I guess we cannot deallocate
554 * it then. But let's at least clear the screen */
556 fd
= open_terminal(name
, O_RDWR
|O_NOCTTY
|O_CLOEXEC
);
561 "\033[r" /* clear scrolling region */
562 "\033[H" /* move home */
563 "\033[2J", /* clear screen */
570 if (!startswith(name
, "/dev/tty"))
573 r
= safe_atou(name
+8, &u
);
580 /* Try to deallocate */
581 fd
= open_terminal("/dev/tty0", O_RDWR
|O_NOCTTY
|O_CLOEXEC
|O_NONBLOCK
);
585 r
= ioctl(fd
, VT_DISALLOCATE
, u
);
594 /* Couldn't deallocate, so let's clear it fully with
596 fd
= open_terminal(name
, O_RDWR
|O_NOCTTY
|O_CLOEXEC
);
601 "\033[r" /* clear scrolling region */
602 "\033[H" /* move home */
603 "\033[3J", /* clear screen including scrollback, requires Linux 2.6.40 */
610 void warn_melody(void) {
611 _cleanup_close_
int fd
= -1;
613 fd
= open("/dev/console", O_WRONLY
|O_CLOEXEC
|O_NOCTTY
);
617 /* Yeah, this is synchronous. Kinda sucks. But well... */
619 (void) ioctl(fd
, KIOCSOUND
, (int)(1193180/440));
620 usleep(125*USEC_PER_MSEC
);
622 (void) ioctl(fd
, KIOCSOUND
, (int)(1193180/220));
623 usleep(125*USEC_PER_MSEC
);
625 (void) ioctl(fd
, KIOCSOUND
, (int)(1193180/220));
626 usleep(125*USEC_PER_MSEC
);
628 (void) ioctl(fd
, KIOCSOUND
, 0);
631 int make_console_stdio(void) {
634 /* Make /dev/console the controlling terminal and stdin/stdout/stderr */
636 fd
= acquire_terminal("/dev/console", false, true, true, USEC_INFINITY
);
638 return log_error_errno(fd
, "Failed to acquire terminal: %m");
642 return log_error_errno(r
, "Failed to duplicate terminal fd: %m");
647 int status_vprintf(const char *status
, bool ellipse
, bool ephemeral
, const char *format
, va_list ap
) {
648 static const char status_indent
[] = " "; /* "[" STATUS "] " */
649 _cleanup_free_
char *s
= NULL
;
650 _cleanup_close_
int fd
= -1;
651 struct iovec iovec
[6] = {};
653 static bool prev_ephemeral
;
657 /* This is independent of logging, as status messages are
658 * optional and go exclusively to the console. */
660 if (vasprintf(&s
, format
, ap
) < 0)
663 fd
= open_terminal("/dev/console", O_WRONLY
|O_NOCTTY
|O_CLOEXEC
);
676 sl
= status
? sizeof(status_indent
)-1 : 0;
682 e
= ellipsize(s
, emax
, 50);
690 IOVEC_SET_STRING(iovec
[n
++], "\r" ANSI_ERASE_TO_END_OF_LINE
);
691 prev_ephemeral
= ephemeral
;
694 if (!isempty(status
)) {
695 IOVEC_SET_STRING(iovec
[n
++], "[");
696 IOVEC_SET_STRING(iovec
[n
++], status
);
697 IOVEC_SET_STRING(iovec
[n
++], "] ");
699 IOVEC_SET_STRING(iovec
[n
++], status_indent
);
702 IOVEC_SET_STRING(iovec
[n
++], s
);
704 IOVEC_SET_STRING(iovec
[n
++], "\n");
706 if (writev(fd
, iovec
, n
) < 0)
712 int status_printf(const char *status
, bool ellipse
, bool ephemeral
, const char *format
, ...) {
718 va_start(ap
, format
);
719 r
= status_vprintf(status
, ellipse
, ephemeral
, format
, ap
);
725 bool tty_is_vc(const char *tty
) {
728 return vtnr_from_tty(tty
) >= 0;
731 bool tty_is_console(const char *tty
) {
734 if (startswith(tty
, "/dev/"))
737 return streq(tty
, "console");
740 int vtnr_from_tty(const char *tty
) {
745 if (startswith(tty
, "/dev/"))
748 if (!startswith(tty
, "tty") )
751 if (tty
[3] < '0' || tty
[3] > '9')
754 r
= safe_atoi(tty
+3, &i
);
764 char *resolve_dev_console(char **active
) {
767 /* Resolve where /dev/console is pointing to, if /sys is actually ours
768 * (i.e. not read-only-mounted which is a sign for container setups) */
770 if (path_is_read_only_fs("/sys") > 0)
773 if (read_one_line_file("/sys/class/tty/console/active", active
) < 0)
776 /* If multiple log outputs are configured the last one is what
777 * /dev/console points to */
778 tty
= strrchr(*active
, ' ');
784 if (streq(tty
, "tty0")) {
787 /* Get the active VC (e.g. tty1) */
788 if (read_one_line_file("/sys/class/tty/tty0/active", &tmp
) >= 0) {
797 bool tty_is_vc_resolve(const char *tty
) {
798 _cleanup_free_
char *active
= NULL
;
802 if (startswith(tty
, "/dev/"))
805 if (streq(tty
, "console")) {
806 tty
= resolve_dev_console(&active
);
811 return tty_is_vc(tty
);
814 const char *default_term_for_tty(const char *tty
) {
817 return tty_is_vc_resolve(tty
) ? "TERM=linux" : "TERM=vt220";
820 int fd_columns(int fd
) {
821 struct winsize ws
= {};
823 if (ioctl(fd
, TIOCGWINSZ
, &ws
) < 0)
832 unsigned columns(void) {
836 if (_likely_(cached_columns
> 0))
837 return cached_columns
;
840 e
= getenv("COLUMNS");
842 (void) safe_atoi(e
, &c
);
845 c
= fd_columns(STDOUT_FILENO
);
851 return cached_columns
;
854 int fd_lines(int fd
) {
855 struct winsize ws
= {};
857 if (ioctl(fd
, TIOCGWINSZ
, &ws
) < 0)
866 unsigned lines(void) {
870 if (_likely_(cached_lines
> 0))
876 (void) safe_atoi(e
, &l
);
879 l
= fd_lines(STDOUT_FILENO
);
888 /* intended to be used as a SIGWINCH sighandler */
889 void columns_lines_cache_reset(int signum
) {
895 static int cached_on_tty
= -1;
897 if (_unlikely_(cached_on_tty
< 0))
898 cached_on_tty
= isatty(STDOUT_FILENO
) > 0;
900 return cached_on_tty
;
903 int make_stdio(int fd
) {
908 r
= dup2(fd
, STDIN_FILENO
);
909 s
= dup2(fd
, STDOUT_FILENO
);
910 t
= dup2(fd
, STDERR_FILENO
);
915 if (r
< 0 || s
< 0 || t
< 0)
918 /* Explicitly unset O_CLOEXEC, since if fd was < 3, then
919 * dup2() was a NOP and the bit hence possibly set. */
920 fd_cloexec(STDIN_FILENO
, false);
921 fd_cloexec(STDOUT_FILENO
, false);
922 fd_cloexec(STDERR_FILENO
, false);
927 int make_null_stdio(void) {
930 null_fd
= open("/dev/null", O_RDWR
|O_NOCTTY
);
934 return make_stdio(null_fd
);
937 int getttyname_malloc(int fd
, char **ret
) {
947 r
= ttyname_r(fd
, path
, sizeof(path
));
952 p
= startswith(path
, "/dev/");
953 c
= strdup(p
?: path
);
970 int getttyname_harder(int fd
, char **r
) {
974 k
= getttyname_malloc(fd
, &s
);
978 if (streq(s
, "tty")) {
980 return get_ctty(0, NULL
, r
);
987 int get_ctty_devnr(pid_t pid
, dev_t
*d
) {
989 _cleanup_free_
char *line
= NULL
;
995 p
= procfs_file_alloca(pid
, "stat");
996 r
= read_one_line_file(p
, &line
);
1000 p
= strrchr(line
, ')');
1010 "%*d " /* session */
1015 if (major(ttynr
) == 0 && minor(ttynr
) == 0)
1024 int get_ctty(pid_t pid
, dev_t
*_devnr
, char **r
) {
1025 char fn
[sizeof("/dev/char/")-1 + 2*DECIMAL_STR_MAX(unsigned) + 1 + 1], *b
= NULL
;
1026 _cleanup_free_
char *s
= NULL
;
1033 k
= get_ctty_devnr(pid
, &devnr
);
1037 sprintf(fn
, "/dev/char/%u:%u", major(devnr
), minor(devnr
));
1039 k
= readlink_malloc(fn
, &s
);
1045 /* This is an ugly hack */
1046 if (major(devnr
) == 136) {
1047 if (asprintf(&b
, "pts/%u", minor(devnr
)) < 0)
1050 /* Probably something like the ptys which have no
1051 * symlink in /dev/char. Let's return something
1052 * vaguely useful. */
1059 if (startswith(s
, "/dev/"))
1061 else if (startswith(s
, "../"))
1078 int ptsname_namespace(int pty
, char **ret
) {
1081 /* Like ptsname(), but doesn't assume that the path is
1082 * accessible in the local namespace. */
1084 r
= ioctl(pty
, TIOCGPTN
, &no
);
1091 if (asprintf(ret
, "/dev/pts/%i", no
) < 0)