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/>.
23 #include <linux/tiocl.h>
27 #include <sys/ioctl.h>
29 #include <sys/types.h>
34 #include "alloc-util.h"
39 #include "parse-util.h"
40 #include "path-util.h"
41 #include "process-util.h"
42 #include "socket-util.h"
43 #include "stat-util.h"
44 #include "string-util.h"
45 #include "terminal-util.h"
46 #include "time-util.h"
49 static volatile unsigned cached_columns = 0;
50 static volatile unsigned cached_lines = 0;
53 _cleanup_close_ int fd;
55 fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
61 TIOCL_GETKMSGREDIRECT,
65 if (ioctl(fd, TIOCLINUX, tiocl) < 0)
68 vt = tiocl[0] <= 0 ? 1 : tiocl[0];
71 if (ioctl(fd, VT_ACTIVATE, vt) < 0)
77 #if 0 /// UNNEEDED by elogind
78 int read_one_char(FILE *f, char *ret, usec_t t, bool *need_nl) {
79 struct termios old_termios, new_termios;
80 char c, line[LINE_MAX];
85 if (tcgetattr(fileno(f), &old_termios) >= 0) {
86 new_termios = old_termios;
88 new_termios.c_lflag &= ~ICANON;
89 new_termios.c_cc[VMIN] = 1;
90 new_termios.c_cc[VTIME] = 0;
92 if (tcsetattr(fileno(f), TCSADRAIN, &new_termios) >= 0) {
95 if (t != USEC_INFINITY) {
96 if (fd_wait_for_event(fileno(f), POLLIN, t) <= 0) {
97 tcsetattr(fileno(f), TCSADRAIN, &old_termios);
102 k = fread(&c, 1, 1, f);
104 tcsetattr(fileno(f), TCSADRAIN, &old_termios);
110 *need_nl = c != '\n';
117 if (t != USEC_INFINITY) {
118 if (fd_wait_for_event(fileno(f), POLLIN, t) <= 0)
123 if (!fgets(line, sizeof(line), f))
124 return errno ? -errno : -EIO;
128 if (strlen(line) != 1)
138 int ask_char(char *ret, const char *replies, const char *text, ...) {
151 fputs(ANSI_HIGHLIGHT, stdout);
158 fputs(ANSI_NORMAL, stdout);
162 r = read_one_char(stdin, &c, USEC_INFINITY, &need_nl);
166 puts("Bad input, please try again.");
177 if (strchr(replies, c)) {
182 puts("Read unexpected character, please try again.");
186 int ask_string(char **ret, const char *text, ...) {
195 fputs(ANSI_HIGHLIGHT, stdout);
202 fputs(ANSI_NORMAL, stdout);
207 if (!fgets(line, sizeof(line), stdin))
208 return errno ? -errno : -EIO;
210 if (!endswith(line, "\n"))
229 int reset_terminal_fd(int fd, bool switch_to_text) {
230 struct termios termios;
233 /* Set terminal to some sane defaults */
237 /* We leave locked terminal attributes untouched, so that
238 * Plymouth may set whatever it wants to set, and we don't
239 * interfere with that. */
241 /* Disable exclusive mode, just in case */
242 (void) ioctl(fd, TIOCNXCL);
244 /* Switch to text mode */
246 (void) ioctl(fd, KDSETMODE, KD_TEXT);
248 /* Enable console unicode mode */
249 (void) ioctl(fd, KDSKBMODE, K_UNICODE);
251 if (tcgetattr(fd, &termios) < 0) {
256 /* We only reset the stuff that matters to the software. How
257 * hardware is set up we don't touch assuming that somebody
258 * else will do that for us */
260 termios.c_iflag &= ~(IGNBRK | BRKINT | ISTRIP | INLCR | IGNCR | IUCLC);
261 termios.c_iflag |= ICRNL | IMAXBEL | IUTF8;
262 termios.c_oflag |= ONLCR;
263 termios.c_cflag |= CREAD;
264 termios.c_lflag = ISIG | ICANON | IEXTEN | ECHO | ECHOE | ECHOK | ECHOCTL | ECHOPRT | ECHOKE;
266 termios.c_cc[VINTR] = 03; /* ^C */
267 termios.c_cc[VQUIT] = 034; /* ^\ */
268 termios.c_cc[VERASE] = 0177;
269 termios.c_cc[VKILL] = 025; /* ^X */
270 termios.c_cc[VEOF] = 04; /* ^D */
271 termios.c_cc[VSTART] = 021; /* ^Q */
272 termios.c_cc[VSTOP] = 023; /* ^S */
273 termios.c_cc[VSUSP] = 032; /* ^Z */
274 termios.c_cc[VLNEXT] = 026; /* ^V */
275 termios.c_cc[VWERASE] = 027; /* ^W */
276 termios.c_cc[VREPRINT] = 022; /* ^R */
277 termios.c_cc[VEOL] = 0;
278 termios.c_cc[VEOL2] = 0;
280 termios.c_cc[VTIME] = 0;
281 termios.c_cc[VMIN] = 1;
283 if (tcsetattr(fd, TCSANOW, &termios) < 0)
287 /* Just in case, flush all crap out */
288 (void) tcflush(fd, TCIOFLUSH);
293 int reset_terminal(const char *name) {
294 _cleanup_close_ int fd = -1;
296 /* We open the terminal with O_NONBLOCK here, to ensure we
297 * don't block on carrier if this is a terminal with carrier
300 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
304 return reset_terminal_fd(fd, true);
308 int open_terminal(const char *name, int mode) {
313 * If a TTY is in the process of being closed opening it might
314 * cause EIO. This is horribly awful, but unlikely to be
315 * changed in the kernel. Hence we work around this problem by
316 * retrying a couple of times.
318 * https://bugs.launchpad.net/ubuntu/+source/linux/+bug/554172/comments/245
325 fd = open(name, mode, 0);
332 /* Max 1s in total */
336 usleep(50 * USEC_PER_MSEC);
354 #if 0 /// UNNEEDED by elogind
355 int acquire_terminal(
359 bool ignore_tiocstty_eperm,
362 int fd = -1, notify = -1, r = 0, wd = -1;
367 /* We use inotify to be notified when the tty is closed. We
368 * create the watch before checking if we can actually acquire
369 * it, so that we don't lose any event.
371 * Note: strictly speaking this actually watches for the
372 * device being closed, it does *not* really watch whether a
373 * tty loses its controlling process. However, unless some
374 * rogue process uses TIOCNOTTY on /dev/tty *after* closing
375 * its tty otherwise this will not become a problem. As long
376 * as the administrator makes sure not configure any service
377 * on the same tty as an untrusted user this should not be a
378 * problem. (Which he probably should not do anyway.) */
380 if (timeout != USEC_INFINITY)
381 ts = now(CLOCK_MONOTONIC);
383 if (!fail && !force) {
384 notify = inotify_init1(IN_CLOEXEC | (timeout != USEC_INFINITY ? IN_NONBLOCK : 0));
390 wd = inotify_add_watch(notify, name, IN_CLOSE);
398 struct sigaction sa_old, sa_new = {
399 .sa_handler = SIG_IGN,
400 .sa_flags = SA_RESTART,
404 r = flush_fd(notify);
409 /* We pass here O_NOCTTY only so that we can check the return
410 * value TIOCSCTTY and have a reliable way to figure out if we
411 * successfully became the controlling process of the tty */
412 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
416 /* Temporarily ignore SIGHUP, so that we don't get SIGHUP'ed
417 * if we already own the tty. */
418 assert_se(sigaction(SIGHUP, &sa_new, &sa_old) == 0);
420 /* First, try to get the tty */
421 if (ioctl(fd, TIOCSCTTY, force) < 0)
424 assert_se(sigaction(SIGHUP, &sa_old, NULL) == 0);
426 /* Sometimes, it makes sense to ignore TIOCSCTTY
427 * returning EPERM, i.e. when very likely we already
428 * are have this controlling terminal. */
429 if (r < 0 && r == -EPERM && ignore_tiocstty_eperm)
432 if (r < 0 && (force || fail || r != -EPERM))
443 union inotify_event_buffer buffer;
444 struct inotify_event *e;
447 if (timeout != USEC_INFINITY) {
450 n = now(CLOCK_MONOTONIC);
451 if (ts + timeout < n) {
456 r = fd_wait_for_event(fd, POLLIN, ts + timeout - n);
466 l = read(notify, &buffer, sizeof(buffer));
468 if (errno == EINTR || errno == EAGAIN)
475 FOREACH_INOTIFY_EVENT(e, buffer, l) {
476 if (e->wd != wd || !(e->mask & IN_CLOSE)) {
485 /* We close the tty fd here since if the old session
486 * ended our handle will be dead. It's important that
487 * we do this after sleeping, so that we don't enter
488 * an endless loop. */
504 #if 0 /// UNNEEDED by elogind
505 int release_terminal(void) {
506 static const struct sigaction sa_new = {
507 .sa_handler = SIG_IGN,
508 .sa_flags = SA_RESTART,
511 _cleanup_close_ int fd = -1;
512 struct sigaction sa_old;
515 fd = open("/dev/tty", O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
519 /* Temporarily ignore SIGHUP, so that we don't get SIGHUP'ed
520 * by our own TIOCNOTTY */
521 assert_se(sigaction(SIGHUP, &sa_new, &sa_old) == 0);
523 if (ioctl(fd, TIOCNOTTY) < 0)
526 assert_se(sigaction(SIGHUP, &sa_old, NULL) == 0);
531 int terminal_vhangup_fd(int fd) {
534 if (ioctl(fd, TIOCVHANGUP) < 0)
540 int terminal_vhangup(const char *name) {
541 _cleanup_close_ int fd;
543 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
547 return terminal_vhangup_fd(fd);
550 int vt_disallocate(const char *name) {
551 _cleanup_close_ int fd = -1;
555 /* Deallocate the VT if possible. If not possible
556 * (i.e. because it is the active one), at least clear it
557 * entirely (including the scrollback buffer) */
559 if (!startswith(name, "/dev/"))
562 if (!tty_is_vc(name)) {
563 /* So this is not a VT. I guess we cannot deallocate
564 * it then. But let's at least clear the screen */
566 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
571 "\033[r" /* clear scrolling region */
572 "\033[H" /* move home */
573 "\033[2J", /* clear screen */
578 if (!startswith(name, "/dev/tty"))
581 r = safe_atou(name+8, &u);
588 /* Try to deallocate */
589 fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
593 r = ioctl(fd, VT_DISALLOCATE, u);
602 /* Couldn't deallocate, so let's clear it fully with
604 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
609 "\033[r" /* clear scrolling region */
610 "\033[H" /* move home */
611 "\033[3J", /* clear screen including scrollback, requires Linux 2.6.40 */
616 int make_console_stdio(void) {
619 /* Make /dev/console the controlling terminal and stdin/stdout/stderr */
621 fd = acquire_terminal("/dev/console", false, true, true, USEC_INFINITY);
623 return log_error_errno(fd, "Failed to acquire terminal: %m");
625 r = reset_terminal_fd(fd, true);
627 log_warning_errno(r, "Failed to reset terminal, ignoring: %m");
631 return log_error_errno(r, "Failed to duplicate terminal fd: %m");
637 bool tty_is_vc(const char *tty) {
640 return vtnr_from_tty(tty) >= 0;
643 bool tty_is_console(const char *tty) {
646 if (startswith(tty, "/dev/"))
649 return streq(tty, "console");
652 int vtnr_from_tty(const char *tty) {
657 if (startswith(tty, "/dev/"))
660 if (!startswith(tty, "tty") )
663 if (tty[3] < '0' || tty[3] > '9')
666 r = safe_atoi(tty+3, &i);
676 #if 0 /// UNNEEDED by elogind
677 char *resolve_dev_console(char **active) {
680 /* Resolve where /dev/console is pointing to, if /sys is actually ours
681 * (i.e. not read-only-mounted which is a sign for container setups) */
683 if (path_is_read_only_fs("/sys") > 0)
686 if (read_one_line_file("/sys/class/tty/console/active", active) < 0)
689 /* If multiple log outputs are configured the last one is what
690 * /dev/console points to */
691 tty = strrchr(*active, ' ');
697 if (streq(tty, "tty0")) {
700 /* Get the active VC (e.g. tty1) */
701 if (read_one_line_file("/sys/class/tty/tty0/active", &tmp) >= 0) {
710 bool tty_is_vc_resolve(const char *tty) {
711 _cleanup_free_ char *active = NULL;
715 if (startswith(tty, "/dev/"))
718 if (streq(tty, "console")) {
719 tty = resolve_dev_console(&active);
724 return tty_is_vc(tty);
727 const char *default_term_for_tty(const char *tty) {
730 return tty_is_vc_resolve(tty) ? "TERM=linux" : "TERM=vt220";
734 int fd_columns(int fd) {
735 struct winsize ws = {};
737 if (ioctl(fd, TIOCGWINSZ, &ws) < 0)
746 unsigned columns(void) {
750 if (_likely_(cached_columns > 0))
751 return cached_columns;
754 e = getenv("COLUMNS");
756 (void) safe_atoi(e, &c);
759 c = fd_columns(STDOUT_FILENO);
765 return cached_columns;
768 int fd_lines(int fd) {
769 struct winsize ws = {};
771 if (ioctl(fd, TIOCGWINSZ, &ws) < 0)
780 unsigned lines(void) {
784 if (_likely_(cached_lines > 0))
790 (void) safe_atoi(e, &l);
793 l = fd_lines(STDOUT_FILENO);
802 /* intended to be used as a SIGWINCH sighandler */
803 #if 0 /// UNNEEDED by elogind
804 void columns_lines_cache_reset(int signum) {
811 static int cached_on_tty = -1;
813 if (_unlikely_(cached_on_tty < 0))
814 cached_on_tty = isatty(STDOUT_FILENO) > 0;
816 return cached_on_tty;
819 int make_stdio(int fd) {
824 r = dup2(fd, STDIN_FILENO);
825 s = dup2(fd, STDOUT_FILENO);
826 t = dup2(fd, STDERR_FILENO);
831 if (r < 0 || s < 0 || t < 0)
834 /* Explicitly unset O_CLOEXEC, since if fd was < 3, then
835 * dup2() was a NOP and the bit hence possibly set. */
836 fd_cloexec(STDIN_FILENO, false);
837 fd_cloexec(STDOUT_FILENO, false);
838 fd_cloexec(STDERR_FILENO, false);
843 int make_null_stdio(void) {
846 null_fd = open("/dev/null", O_RDWR|O_NOCTTY);
850 return make_stdio(null_fd);
853 #if 0 /// UNNEEDED by elogind
854 int getttyname_malloc(int fd, char **ret) {
864 r = ttyname_r(fd, path, sizeof(path));
869 p = startswith(path, "/dev/");
870 c = strdup(p ?: path);
887 int getttyname_harder(int fd, char **r) {
891 k = getttyname_malloc(fd, &s);
895 if (streq(s, "tty")) {
897 return get_ctty(0, NULL, r);
905 int get_ctty_devnr(pid_t pid, dev_t *d) {
907 _cleanup_free_ char *line = NULL;
913 p = procfs_file_alloca(pid, "stat");
914 r = read_one_line_file(p, &line);
918 p = strrchr(line, ')');
933 if (major(ttynr) == 0 && minor(ttynr) == 0)
942 int get_ctty(pid_t pid, dev_t *_devnr, char **r) {
943 char fn[sizeof("/dev/char/")-1 + 2*DECIMAL_STR_MAX(unsigned) + 1 + 1], *b = NULL;
944 _cleanup_free_ char *s = NULL;
951 k = get_ctty_devnr(pid, &devnr);
955 sprintf(fn, "/dev/char/%u:%u", major(devnr), minor(devnr));
957 k = readlink_malloc(fn, &s);
963 /* This is an ugly hack */
964 if (major(devnr) == 136) {
965 if (asprintf(&b, "pts/%u", minor(devnr)) < 0)
968 /* Probably something like the ptys which have no
969 * symlink in /dev/char. Let's return something
977 if (startswith(s, "/dev/"))
979 else if (startswith(s, "../"))
996 #if 0 /// UNNEEDED by elogind
997 int ptsname_malloc(int fd, char **ret) {
1010 if (ptsname_r(fd, c, l) == 0) {
1014 if (errno != ERANGE) {
1024 int ptsname_namespace(int pty, char **ret) {
1027 /* Like ptsname(), but doesn't assume that the path is
1028 * accessible in the local namespace. */
1030 r = ioctl(pty, TIOCGPTN, &no);
1037 if (asprintf(ret, "/dev/pts/%i", no) < 0)
1043 int openpt_in_namespace(pid_t pid, int flags) {
1044 _cleanup_close_ int pidnsfd = -1, mntnsfd = -1, usernsfd = -1, rootfd = -1;
1045 _cleanup_close_pair_ int pair[2] = { -1, -1 };
1052 r = namespace_open(pid, &pidnsfd, &mntnsfd, NULL, &usernsfd, &rootfd);
1056 if (socketpair(AF_UNIX, SOCK_DGRAM, 0, pair) < 0)
1066 pair[0] = safe_close(pair[0]);
1068 r = namespace_enter(pidnsfd, mntnsfd, -1, usernsfd, rootfd);
1070 _exit(EXIT_FAILURE);
1072 master = posix_openpt(flags|O_NOCTTY|O_CLOEXEC);
1074 _exit(EXIT_FAILURE);
1076 if (unlockpt(master) < 0)
1077 _exit(EXIT_FAILURE);
1079 if (send_one_fd(pair[1], master, 0) < 0)
1080 _exit(EXIT_FAILURE);
1082 _exit(EXIT_SUCCESS);
1085 pair[1] = safe_close(pair[1]);
1087 r = wait_for_terminate(child, &si);
1090 if (si.si_code != CLD_EXITED || si.si_status != EXIT_SUCCESS)
1093 return receive_one_fd(pair[0], 0);
1096 int open_terminal_in_namespace(pid_t pid, const char *name, int mode) {
1097 _cleanup_close_ int pidnsfd = -1, mntnsfd = -1, usernsfd = -1, rootfd = -1;
1098 _cleanup_close_pair_ int pair[2] = { -1, -1 };
1103 r = namespace_open(pid, &pidnsfd, &mntnsfd, NULL, &usernsfd, &rootfd);
1107 if (socketpair(AF_UNIX, SOCK_DGRAM, 0, pair) < 0)
1117 pair[0] = safe_close(pair[0]);
1119 r = namespace_enter(pidnsfd, mntnsfd, -1, usernsfd, rootfd);
1121 _exit(EXIT_FAILURE);
1123 master = open_terminal(name, mode|O_NOCTTY|O_CLOEXEC);
1125 _exit(EXIT_FAILURE);
1127 if (send_one_fd(pair[1], master, 0) < 0)
1128 _exit(EXIT_FAILURE);
1130 _exit(EXIT_SUCCESS);
1133 pair[1] = safe_close(pair[1]);
1135 r = wait_for_terminate(child, &si);
1138 if (si.si_code != CLD_EXITED || si.si_status != EXIT_SUCCESS)
1141 return receive_one_fd(pair[0], 0);