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/>.
27 #include <sys/inotify.h>
28 #include <sys/socket.h>
29 #include <sys/sysmacros.h>
32 #include <linux/tiocl.h>
36 #include <sys/ioctl.h>
37 #include <sys/types.h>
41 #include "alloc-util.h"
48 #include "parse-util.h"
49 #include "process-util.h"
50 #include "socket-util.h"
51 #include "stat-util.h"
52 #include "string-util.h"
53 #include "terminal-util.h"
54 #include "time-util.h"
57 static volatile unsigned cached_columns = 0;
58 static volatile unsigned cached_lines = 0;
61 _cleanup_close_ int fd;
63 fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
69 TIOCL_GETKMSGREDIRECT,
73 if (ioctl(fd, TIOCLINUX, tiocl) < 0)
76 vt = tiocl[0] <= 0 ? 1 : tiocl[0];
79 if (ioctl(fd, VT_ACTIVATE, vt) < 0)
85 #if 0 /// UNNEEDED by elogind
86 int read_one_char(FILE *f, char *ret, usec_t t, bool *need_nl) {
87 struct termios old_termios, new_termios;
88 char c, line[LINE_MAX];
93 if (tcgetattr(fileno(f), &old_termios) >= 0) {
94 new_termios = old_termios;
96 new_termios.c_lflag &= ~ICANON;
97 new_termios.c_cc[VMIN] = 1;
98 new_termios.c_cc[VTIME] = 0;
100 if (tcsetattr(fileno(f), TCSADRAIN, &new_termios) >= 0) {
103 if (t != USEC_INFINITY) {
104 if (fd_wait_for_event(fileno(f), POLLIN, t) <= 0) {
105 tcsetattr(fileno(f), TCSADRAIN, &old_termios);
110 k = fread(&c, 1, 1, f);
112 tcsetattr(fileno(f), TCSADRAIN, &old_termios);
118 *need_nl = c != '\n';
125 if (t != USEC_INFINITY) {
126 if (fd_wait_for_event(fileno(f), POLLIN, t) <= 0)
131 if (!fgets(line, sizeof(line), f))
132 return errno > 0 ? -errno : -EIO;
136 if (strlen(line) != 1)
146 int ask_char(char *ret, const char *replies, const char *text, ...) {
159 fputs(ANSI_HIGHLIGHT, stdout);
166 fputs(ANSI_NORMAL, stdout);
170 r = read_one_char(stdin, &c, USEC_INFINITY, &need_nl);
174 puts("Bad input, please try again.");
185 if (strchr(replies, c)) {
190 puts("Read unexpected character, please try again.");
194 int ask_string(char **ret, const char *text, ...) {
203 fputs(ANSI_HIGHLIGHT, stdout);
210 fputs(ANSI_NORMAL, stdout);
215 if (!fgets(line, sizeof(line), stdin))
216 return errno > 0 ? -errno : -EIO;
218 if (!endswith(line, "\n"))
237 int reset_terminal_fd(int fd, bool switch_to_text) {
238 struct termios termios;
241 /* Set terminal to some sane defaults */
245 /* We leave locked terminal attributes untouched, so that
246 * Plymouth may set whatever it wants to set, and we don't
247 * interfere with that. */
249 /* Disable exclusive mode, just in case */
250 (void) ioctl(fd, TIOCNXCL);
252 /* Switch to text mode */
254 (void) ioctl(fd, KDSETMODE, KD_TEXT);
256 /* Enable console unicode mode */
257 (void) ioctl(fd, KDSKBMODE, K_UNICODE);
259 if (tcgetattr(fd, &termios) < 0) {
264 /* We only reset the stuff that matters to the software. How
265 * hardware is set up we don't touch assuming that somebody
266 * else will do that for us */
268 termios.c_iflag &= ~(IGNBRK | BRKINT | ISTRIP | INLCR | IGNCR | IUCLC);
269 termios.c_iflag |= ICRNL | IMAXBEL | IUTF8;
270 termios.c_oflag |= ONLCR;
271 termios.c_cflag |= CREAD;
272 termios.c_lflag = ISIG | ICANON | IEXTEN | ECHO | ECHOE | ECHOK | ECHOCTL | ECHOPRT | ECHOKE;
274 termios.c_cc[VINTR] = 03; /* ^C */
275 termios.c_cc[VQUIT] = 034; /* ^\ */
276 termios.c_cc[VERASE] = 0177;
277 termios.c_cc[VKILL] = 025; /* ^X */
278 termios.c_cc[VEOF] = 04; /* ^D */
279 termios.c_cc[VSTART] = 021; /* ^Q */
280 termios.c_cc[VSTOP] = 023; /* ^S */
281 termios.c_cc[VSUSP] = 032; /* ^Z */
282 termios.c_cc[VLNEXT] = 026; /* ^V */
283 termios.c_cc[VWERASE] = 027; /* ^W */
284 termios.c_cc[VREPRINT] = 022; /* ^R */
285 termios.c_cc[VEOL] = 0;
286 termios.c_cc[VEOL2] = 0;
288 termios.c_cc[VTIME] = 0;
289 termios.c_cc[VMIN] = 1;
291 if (tcsetattr(fd, TCSANOW, &termios) < 0)
295 /* Just in case, flush all crap out */
296 (void) tcflush(fd, TCIOFLUSH);
301 int reset_terminal(const char *name) {
302 _cleanup_close_ int fd = -1;
304 /* We open the terminal with O_NONBLOCK here, to ensure we
305 * don't block on carrier if this is a terminal with carrier
308 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
312 return reset_terminal_fd(fd, true);
316 int open_terminal(const char *name, int mode) {
321 * If a TTY is in the process of being closed opening it might
322 * cause EIO. This is horribly awful, but unlikely to be
323 * changed in the kernel. Hence we work around this problem by
324 * retrying a couple of times.
326 * https://bugs.launchpad.net/ubuntu/+source/linux/+bug/554172/comments/245
333 fd = open(name, mode, 0);
340 /* Max 1s in total */
344 usleep(50 * USEC_PER_MSEC);
362 #if 0 /// UNNEEDED by elogind
363 int acquire_terminal(
367 bool ignore_tiocstty_eperm,
370 int fd = -1, notify = -1, r = 0, wd = -1;
375 /* We use inotify to be notified when the tty is closed. We
376 * create the watch before checking if we can actually acquire
377 * it, so that we don't lose any event.
379 * Note: strictly speaking this actually watches for the
380 * device being closed, it does *not* really watch whether a
381 * tty loses its controlling process. However, unless some
382 * rogue process uses TIOCNOTTY on /dev/tty *after* closing
383 * its tty otherwise this will not become a problem. As long
384 * as the administrator makes sure not configure any service
385 * on the same tty as an untrusted user this should not be a
386 * problem. (Which he probably should not do anyway.) */
388 if (timeout != USEC_INFINITY)
389 ts = now(CLOCK_MONOTONIC);
391 if (!fail && !force) {
392 notify = inotify_init1(IN_CLOEXEC | (timeout != USEC_INFINITY ? IN_NONBLOCK : 0));
398 wd = inotify_add_watch(notify, name, IN_CLOSE);
406 struct sigaction sa_old, sa_new = {
407 .sa_handler = SIG_IGN,
408 .sa_flags = SA_RESTART,
412 r = flush_fd(notify);
417 /* We pass here O_NOCTTY only so that we can check the return
418 * value TIOCSCTTY and have a reliable way to figure out if we
419 * successfully became the controlling process of the tty */
420 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
424 /* Temporarily ignore SIGHUP, so that we don't get SIGHUP'ed
425 * if we already own the tty. */
426 assert_se(sigaction(SIGHUP, &sa_new, &sa_old) == 0);
428 /* First, try to get the tty */
429 if (ioctl(fd, TIOCSCTTY, force) < 0)
432 assert_se(sigaction(SIGHUP, &sa_old, NULL) == 0);
434 /* Sometimes, it makes sense to ignore TIOCSCTTY
435 * returning EPERM, i.e. when very likely we already
436 * are have this controlling terminal. */
437 if (r < 0 && r == -EPERM && ignore_tiocstty_eperm)
440 if (r < 0 && (force || fail || r != -EPERM))
451 union inotify_event_buffer buffer;
452 struct inotify_event *e;
455 if (timeout != USEC_INFINITY) {
458 n = now(CLOCK_MONOTONIC);
459 if (ts + timeout < n) {
464 r = fd_wait_for_event(fd, POLLIN, ts + timeout - n);
474 l = read(notify, &buffer, sizeof(buffer));
476 if (errno == EINTR || errno == EAGAIN)
483 FOREACH_INOTIFY_EVENT(e, buffer, l) {
484 if (e->wd != wd || !(e->mask & IN_CLOSE)) {
493 /* We close the tty fd here since if the old session
494 * ended our handle will be dead. It's important that
495 * we do this after sleeping, so that we don't enter
496 * an endless loop. */
512 #if 0 /// UNNEEDED by elogind
513 int release_terminal(void) {
514 static const struct sigaction sa_new = {
515 .sa_handler = SIG_IGN,
516 .sa_flags = SA_RESTART,
519 _cleanup_close_ int fd = -1;
520 struct sigaction sa_old;
523 fd = open("/dev/tty", O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
527 /* Temporarily ignore SIGHUP, so that we don't get SIGHUP'ed
528 * by our own TIOCNOTTY */
529 assert_se(sigaction(SIGHUP, &sa_new, &sa_old) == 0);
531 if (ioctl(fd, TIOCNOTTY) < 0)
534 assert_se(sigaction(SIGHUP, &sa_old, NULL) == 0);
539 int terminal_vhangup_fd(int fd) {
542 if (ioctl(fd, TIOCVHANGUP) < 0)
548 int terminal_vhangup(const char *name) {
549 _cleanup_close_ int fd;
551 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
555 return terminal_vhangup_fd(fd);
558 int vt_disallocate(const char *name) {
559 _cleanup_close_ int fd = -1;
563 /* Deallocate the VT if possible. If not possible
564 * (i.e. because it is the active one), at least clear it
565 * entirely (including the scrollback buffer) */
567 if (!startswith(name, "/dev/"))
570 if (!tty_is_vc(name)) {
571 /* So this is not a VT. I guess we cannot deallocate
572 * it then. But let's at least clear the screen */
574 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
579 "\033[r" /* clear scrolling region */
580 "\033[H" /* move home */
581 "\033[2J", /* clear screen */
586 if (!startswith(name, "/dev/tty"))
589 r = safe_atou(name+8, &u);
596 /* Try to deallocate */
597 fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
601 r = ioctl(fd, VT_DISALLOCATE, u);
610 /* Couldn't deallocate, so let's clear it fully with
612 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
617 "\033[r" /* clear scrolling region */
618 "\033[H" /* move home */
619 "\033[3J", /* clear screen including scrollback, requires Linux 2.6.40 */
624 int make_console_stdio(void) {
627 /* Make /dev/console the controlling terminal and stdin/stdout/stderr */
629 fd = acquire_terminal("/dev/console", false, true, true, USEC_INFINITY);
631 return log_error_errno(fd, "Failed to acquire terminal: %m");
633 r = reset_terminal_fd(fd, true);
635 log_warning_errno(r, "Failed to reset terminal, ignoring: %m");
639 return log_error_errno(r, "Failed to duplicate terminal fd: %m");
645 bool tty_is_vc(const char *tty) {
648 return vtnr_from_tty(tty) >= 0;
651 bool tty_is_console(const char *tty) {
654 if (startswith(tty, "/dev/"))
657 return streq(tty, "console");
660 int vtnr_from_tty(const char *tty) {
665 if (startswith(tty, "/dev/"))
668 if (!startswith(tty, "tty") )
671 if (tty[3] < '0' || tty[3] > '9')
674 r = safe_atoi(tty+3, &i);
684 #if 0 /// UNNEEDED by elogind
685 char *resolve_dev_console(char **active) {
688 /* Resolve where /dev/console is pointing to, if /sys is actually ours
689 * (i.e. not read-only-mounted which is a sign for container setups) */
691 if (path_is_read_only_fs("/sys") > 0)
694 if (read_one_line_file("/sys/class/tty/console/active", active) < 0)
697 /* If multiple log outputs are configured the last one is what
698 * /dev/console points to */
699 tty = strrchr(*active, ' ');
705 if (streq(tty, "tty0")) {
708 /* Get the active VC (e.g. tty1) */
709 if (read_one_line_file("/sys/class/tty/tty0/active", &tmp) >= 0) {
718 bool tty_is_vc_resolve(const char *tty) {
719 _cleanup_free_ char *active = NULL;
723 if (startswith(tty, "/dev/"))
726 if (streq(tty, "console")) {
727 tty = resolve_dev_console(&active);
732 return tty_is_vc(tty);
735 const char *default_term_for_tty(const char *tty) {
736 return tty && tty_is_vc_resolve(tty) ? "TERM=linux" : "TERM=vt220";
740 int fd_columns(int fd) {
741 struct winsize ws = {};
743 if (ioctl(fd, TIOCGWINSZ, &ws) < 0)
752 unsigned columns(void) {
756 if (_likely_(cached_columns > 0))
757 return cached_columns;
760 e = getenv("COLUMNS");
762 (void) safe_atoi(e, &c);
765 c = fd_columns(STDOUT_FILENO);
771 return cached_columns;
774 int fd_lines(int fd) {
775 struct winsize ws = {};
777 if (ioctl(fd, TIOCGWINSZ, &ws) < 0)
786 unsigned lines(void) {
790 if (_likely_(cached_lines > 0))
796 (void) safe_atoi(e, &l);
799 l = fd_lines(STDOUT_FILENO);
808 /* intended to be used as a SIGWINCH sighandler */
809 #if 0 /// UNNEEDED by elogind
810 void columns_lines_cache_reset(int signum) {
817 static int cached_on_tty = -1;
819 if (_unlikely_(cached_on_tty < 0))
820 cached_on_tty = isatty(STDOUT_FILENO) > 0;
822 return cached_on_tty;
825 int make_stdio(int fd) {
830 r = dup2(fd, STDIN_FILENO);
831 s = dup2(fd, STDOUT_FILENO);
832 t = dup2(fd, STDERR_FILENO);
837 if (r < 0 || s < 0 || t < 0)
840 /* Explicitly unset O_CLOEXEC, since if fd was < 3, then
841 * dup2() was a NOP and the bit hence possibly set. */
842 fd_cloexec(STDIN_FILENO, false);
843 fd_cloexec(STDOUT_FILENO, false);
844 fd_cloexec(STDERR_FILENO, false);
849 int make_null_stdio(void) {
852 null_fd = open("/dev/null", O_RDWR|O_NOCTTY);
856 return make_stdio(null_fd);
859 #if 0 /// UNNEEDED by elogind
860 int getttyname_malloc(int fd, char **ret) {
870 r = ttyname_r(fd, path, sizeof(path));
875 p = startswith(path, "/dev/");
876 c = strdup(p ?: path);
893 int getttyname_harder(int fd, char **r) {
897 k = getttyname_malloc(fd, &s);
901 if (streq(s, "tty")) {
903 return get_ctty(0, NULL, r);
911 int get_ctty_devnr(pid_t pid, dev_t *d) {
913 _cleanup_free_ char *line = NULL;
919 p = procfs_file_alloca(pid, "stat");
920 r = read_one_line_file(p, &line);
924 p = strrchr(line, ')');
939 if (major(ttynr) == 0 && minor(ttynr) == 0)
948 int get_ctty(pid_t pid, dev_t *_devnr, char **r) {
949 char fn[sizeof("/dev/char/")-1 + 2*DECIMAL_STR_MAX(unsigned) + 1 + 1], *b = NULL;
950 _cleanup_free_ char *s = NULL;
957 k = get_ctty_devnr(pid, &devnr);
961 sprintf(fn, "/dev/char/%u:%u", major(devnr), minor(devnr));
963 k = readlink_malloc(fn, &s);
969 /* This is an ugly hack */
970 if (major(devnr) == 136) {
971 if (asprintf(&b, "pts/%u", minor(devnr)) < 0)
974 /* Probably something like the ptys which have no
975 * symlink in /dev/char. Let's return something
983 if (startswith(s, "/dev/"))
985 else if (startswith(s, "../"))
1002 #if 0 /// UNNEEDED by elogind
1003 int ptsname_malloc(int fd, char **ret) {
1016 if (ptsname_r(fd, c, l) == 0) {
1020 if (errno != ERANGE) {
1030 int ptsname_namespace(int pty, char **ret) {
1033 /* Like ptsname(), but doesn't assume that the path is
1034 * accessible in the local namespace. */
1036 r = ioctl(pty, TIOCGPTN, &no);
1043 if (asprintf(ret, "/dev/pts/%i", no) < 0)
1049 int openpt_in_namespace(pid_t pid, int flags) {
1050 _cleanup_close_ int pidnsfd = -1, mntnsfd = -1, usernsfd = -1, rootfd = -1;
1051 _cleanup_close_pair_ int pair[2] = { -1, -1 };
1058 r = namespace_open(pid, &pidnsfd, &mntnsfd, NULL, &usernsfd, &rootfd);
1062 if (socketpair(AF_UNIX, SOCK_DGRAM, 0, pair) < 0)
1072 pair[0] = safe_close(pair[0]);
1074 r = namespace_enter(pidnsfd, mntnsfd, -1, usernsfd, rootfd);
1076 _exit(EXIT_FAILURE);
1078 master = posix_openpt(flags|O_NOCTTY|O_CLOEXEC);
1080 _exit(EXIT_FAILURE);
1082 if (unlockpt(master) < 0)
1083 _exit(EXIT_FAILURE);
1085 if (send_one_fd(pair[1], master, 0) < 0)
1086 _exit(EXIT_FAILURE);
1088 _exit(EXIT_SUCCESS);
1091 pair[1] = safe_close(pair[1]);
1093 r = wait_for_terminate(child, &si);
1096 if (si.si_code != CLD_EXITED || si.si_status != EXIT_SUCCESS)
1099 return receive_one_fd(pair[0], 0);
1102 int open_terminal_in_namespace(pid_t pid, const char *name, int mode) {
1103 _cleanup_close_ int pidnsfd = -1, mntnsfd = -1, usernsfd = -1, rootfd = -1;
1104 _cleanup_close_pair_ int pair[2] = { -1, -1 };
1109 r = namespace_open(pid, &pidnsfd, &mntnsfd, NULL, &usernsfd, &rootfd);
1113 if (socketpair(AF_UNIX, SOCK_DGRAM, 0, pair) < 0)
1123 pair[0] = safe_close(pair[0]);
1125 r = namespace_enter(pidnsfd, mntnsfd, -1, usernsfd, rootfd);
1127 _exit(EXIT_FAILURE);
1129 master = open_terminal(name, mode|O_NOCTTY|O_CLOEXEC);
1131 _exit(EXIT_FAILURE);
1133 if (send_one_fd(pair[1], master, 0) < 0)
1134 _exit(EXIT_FAILURE);
1136 _exit(EXIT_SUCCESS);
1139 pair[1] = safe_close(pair[1]);
1141 r = wait_for_terminate(child, &si);
1144 if (si.si_code != CLD_EXITED || si.si_status != EXIT_SUCCESS)
1147 return receive_one_fd(pair[0], 0);
1151 bool colors_enabled(void) {
1154 colors = getenv("SYSTEMD_COLORS");
1156 if (streq_ptr(getenv("TERM"), "dumb"))
1161 return parse_boolean(colors) != 0;