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"
54 #include "terminal-util.h"
55 #include "time-util.h"
58 static volatile unsigned cached_columns = 0;
59 static volatile unsigned cached_lines = 0;
62 _cleanup_close_ int fd;
64 fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
70 TIOCL_GETKMSGREDIRECT,
74 if (ioctl(fd, TIOCLINUX, tiocl) < 0)
77 vt = tiocl[0] <= 0 ? 1 : tiocl[0];
80 if (ioctl(fd, VT_ACTIVATE, vt) < 0)
86 #if 0 /// UNNEEDED by elogind
87 int read_one_char(FILE *f, char *ret, usec_t t, bool *need_nl) {
88 struct termios old_termios, new_termios;
89 char c, line[LINE_MAX];
94 if (tcgetattr(fileno(f), &old_termios) >= 0) {
95 new_termios = old_termios;
97 new_termios.c_lflag &= ~ICANON;
98 new_termios.c_cc[VMIN] = 1;
99 new_termios.c_cc[VTIME] = 0;
101 if (tcsetattr(fileno(f), TCSADRAIN, &new_termios) >= 0) {
104 if (t != USEC_INFINITY) {
105 if (fd_wait_for_event(fileno(f), POLLIN, t) <= 0) {
106 tcsetattr(fileno(f), TCSADRAIN, &old_termios);
111 k = fread(&c, 1, 1, f);
113 tcsetattr(fileno(f), TCSADRAIN, &old_termios);
119 *need_nl = c != '\n';
126 if (t != USEC_INFINITY) {
127 if (fd_wait_for_event(fileno(f), POLLIN, t) <= 0)
132 if (!fgets(line, sizeof(line), f))
133 return errno > 0 ? -errno : -EIO;
137 if (strlen(line) != 1)
147 #define DEFAULT_ASK_REFRESH_USEC (2*USEC_PER_SEC)
149 int ask_char(char *ret, const char *replies, const char *fmt, ...) {
161 if (colors_enabled())
162 fputs(ANSI_HIGHLIGHT, stdout);
170 if (colors_enabled())
171 fputs(ANSI_NORMAL, stdout);
175 r = read_one_char(stdin, &c, DEFAULT_ASK_REFRESH_USEC, &need_nl);
182 puts("Bad input, please try again.");
193 if (strchr(replies, c)) {
198 puts("Read unexpected character, please try again.");
202 int ask_string(char **ret, const char *text, ...) {
210 if (colors_enabled())
211 fputs(ANSI_HIGHLIGHT, stdout);
217 if (colors_enabled())
218 fputs(ANSI_NORMAL, stdout);
223 if (!fgets(line, sizeof(line), stdin))
224 return errno > 0 ? -errno : -EIO;
226 if (!endswith(line, "\n"))
245 int reset_terminal_fd(int fd, bool switch_to_text) {
246 struct termios termios;
249 /* Set terminal to some sane defaults */
253 /* We leave locked terminal attributes untouched, so that
254 * Plymouth may set whatever it wants to set, and we don't
255 * interfere with that. */
257 /* Disable exclusive mode, just in case */
258 (void) ioctl(fd, TIOCNXCL);
260 /* Switch to text mode */
262 (void) ioctl(fd, KDSETMODE, KD_TEXT);
264 /* Enable console unicode mode */
265 (void) ioctl(fd, KDSKBMODE, K_UNICODE);
267 if (tcgetattr(fd, &termios) < 0) {
272 /* We only reset the stuff that matters to the software. How
273 * hardware is set up we don't touch assuming that somebody
274 * else will do that for us */
276 termios.c_iflag &= ~(IGNBRK | BRKINT | ISTRIP | INLCR | IGNCR | IUCLC);
277 termios.c_iflag |= ICRNL | IMAXBEL | IUTF8;
278 termios.c_oflag |= ONLCR;
279 termios.c_cflag |= CREAD;
280 termios.c_lflag = ISIG | ICANON | IEXTEN | ECHO | ECHOE | ECHOK | ECHOCTL | ECHOPRT | ECHOKE;
282 termios.c_cc[VINTR] = 03; /* ^C */
283 termios.c_cc[VQUIT] = 034; /* ^\ */
284 termios.c_cc[VERASE] = 0177;
285 termios.c_cc[VKILL] = 025; /* ^X */
286 termios.c_cc[VEOF] = 04; /* ^D */
287 termios.c_cc[VSTART] = 021; /* ^Q */
288 termios.c_cc[VSTOP] = 023; /* ^S */
289 termios.c_cc[VSUSP] = 032; /* ^Z */
290 termios.c_cc[VLNEXT] = 026; /* ^V */
291 termios.c_cc[VWERASE] = 027; /* ^W */
292 termios.c_cc[VREPRINT] = 022; /* ^R */
293 termios.c_cc[VEOL] = 0;
294 termios.c_cc[VEOL2] = 0;
296 termios.c_cc[VTIME] = 0;
297 termios.c_cc[VMIN] = 1;
299 if (tcsetattr(fd, TCSANOW, &termios) < 0)
303 /* Just in case, flush all crap out */
304 (void) tcflush(fd, TCIOFLUSH);
309 int reset_terminal(const char *name) {
310 _cleanup_close_ int fd = -1;
312 /* We open the terminal with O_NONBLOCK here, to ensure we
313 * don't block on carrier if this is a terminal with carrier
316 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
320 return reset_terminal_fd(fd, true);
324 int open_terminal(const char *name, int mode) {
329 * If a TTY is in the process of being closed opening it might
330 * cause EIO. This is horribly awful, but unlikely to be
331 * changed in the kernel. Hence we work around this problem by
332 * retrying a couple of times.
334 * https://bugs.launchpad.net/ubuntu/+source/linux/+bug/554172/comments/245
341 fd = open(name, mode, 0);
348 /* Max 1s in total */
352 usleep(50 * USEC_PER_MSEC);
365 #if 0 /// UNNEEDED by elogind
366 int acquire_terminal(
370 bool ignore_tiocstty_eperm,
373 int fd = -1, notify = -1, r = 0, wd = -1;
378 /* We use inotify to be notified when the tty is closed. We
379 * create the watch before checking if we can actually acquire
380 * it, so that we don't lose any event.
382 * Note: strictly speaking this actually watches for the
383 * device being closed, it does *not* really watch whether a
384 * tty loses its controlling process. However, unless some
385 * rogue process uses TIOCNOTTY on /dev/tty *after* closing
386 * its tty otherwise this will not become a problem. As long
387 * as the administrator makes sure not configure any service
388 * on the same tty as an untrusted user this should not be a
389 * problem. (Which he probably should not do anyway.) */
391 if (timeout != USEC_INFINITY)
392 ts = now(CLOCK_MONOTONIC);
394 if (!fail && !force) {
395 notify = inotify_init1(IN_CLOEXEC | (timeout != USEC_INFINITY ? IN_NONBLOCK : 0));
401 wd = inotify_add_watch(notify, name, IN_CLOSE);
409 struct sigaction sa_old, sa_new = {
410 .sa_handler = SIG_IGN,
411 .sa_flags = SA_RESTART,
415 r = flush_fd(notify);
420 /* We pass here O_NOCTTY only so that we can check the return
421 * value TIOCSCTTY and have a reliable way to figure out if we
422 * successfully became the controlling process of the tty */
423 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
427 /* Temporarily ignore SIGHUP, so that we don't get SIGHUP'ed
428 * if we already own the tty. */
429 assert_se(sigaction(SIGHUP, &sa_new, &sa_old) == 0);
431 /* First, try to get the tty */
432 if (ioctl(fd, TIOCSCTTY, force) < 0)
435 assert_se(sigaction(SIGHUP, &sa_old, NULL) == 0);
437 /* Sometimes, it makes sense to ignore TIOCSCTTY
438 * returning EPERM, i.e. when very likely we already
439 * are have this controlling terminal. */
440 if (r < 0 && r == -EPERM && ignore_tiocstty_eperm)
443 if (r < 0 && (force || fail || r != -EPERM))
454 union inotify_event_buffer buffer;
455 struct inotify_event *e;
458 if (timeout != USEC_INFINITY) {
461 n = now(CLOCK_MONOTONIC);
462 if (ts + timeout < n) {
467 r = fd_wait_for_event(notify, POLLIN, ts + timeout - n);
477 l = read(notify, &buffer, sizeof(buffer));
479 if (errno == EINTR || errno == EAGAIN)
486 FOREACH_INOTIFY_EVENT(e, buffer, l) {
487 if (e->wd != wd || !(e->mask & IN_CLOSE)) {
496 /* We close the tty fd here since if the old session
497 * ended our handle will be dead. It's important that
498 * we do this after sleeping, so that we don't enter
499 * an endless loop. */
515 #if 0 /// UNNEEDED by elogind
516 int release_terminal(void) {
517 static const struct sigaction sa_new = {
518 .sa_handler = SIG_IGN,
519 .sa_flags = SA_RESTART,
522 _cleanup_close_ int fd = -1;
523 struct sigaction sa_old;
526 fd = open("/dev/tty", O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
530 /* Temporarily ignore SIGHUP, so that we don't get SIGHUP'ed
531 * by our own TIOCNOTTY */
532 assert_se(sigaction(SIGHUP, &sa_new, &sa_old) == 0);
534 if (ioctl(fd, TIOCNOTTY) < 0)
537 assert_se(sigaction(SIGHUP, &sa_old, NULL) == 0);
542 int terminal_vhangup_fd(int fd) {
545 if (ioctl(fd, TIOCVHANGUP) < 0)
551 int terminal_vhangup(const char *name) {
552 _cleanup_close_ int fd;
554 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
558 return terminal_vhangup_fd(fd);
561 int vt_disallocate(const char *name) {
562 _cleanup_close_ int fd = -1;
566 /* Deallocate the VT if possible. If not possible
567 * (i.e. because it is the active one), at least clear it
568 * entirely (including the scrollback buffer) */
570 if (!startswith(name, "/dev/"))
573 if (!tty_is_vc(name)) {
574 /* So this is not a VT. I guess we cannot deallocate
575 * it then. But let's at least clear the screen */
577 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
582 "\033[r" /* clear scrolling region */
583 "\033[H" /* move home */
584 "\033[2J", /* clear screen */
589 if (!startswith(name, "/dev/tty"))
592 r = safe_atou(name+8, &u);
599 /* Try to deallocate */
600 fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
604 r = ioctl(fd, VT_DISALLOCATE, u);
613 /* Couldn't deallocate, so let's clear it fully with
615 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
620 "\033[r" /* clear scrolling region */
621 "\033[H" /* move home */
622 "\033[3J", /* clear screen including scrollback, requires Linux 2.6.40 */
627 int make_console_stdio(void) {
630 /* Make /dev/console the controlling terminal and stdin/stdout/stderr */
632 fd = acquire_terminal("/dev/console", false, true, true, USEC_INFINITY);
634 return log_error_errno(fd, "Failed to acquire terminal: %m");
636 r = reset_terminal_fd(fd, true);
638 log_warning_errno(r, "Failed to reset terminal, ignoring: %m");
642 return log_error_errno(r, "Failed to duplicate terminal fd: %m");
648 bool tty_is_vc(const char *tty) {
651 return vtnr_from_tty(tty) >= 0;
654 bool tty_is_console(const char *tty) {
657 if (startswith(tty, "/dev/"))
660 return streq(tty, "console");
663 int vtnr_from_tty(const char *tty) {
668 if (startswith(tty, "/dev/"))
671 if (!startswith(tty, "tty") )
674 if (tty[3] < '0' || tty[3] > '9')
677 r = safe_atoi(tty+3, &i);
687 #if 0 /// UNNEEDED by elogind
688 char *resolve_dev_console(char **active) {
691 /* Resolve where /dev/console is pointing to, if /sys is actually ours
692 * (i.e. not read-only-mounted which is a sign for container setups) */
694 if (path_is_read_only_fs("/sys") > 0)
697 if (read_one_line_file("/sys/class/tty/console/active", active) < 0)
700 /* If multiple log outputs are configured the last one is what
701 * /dev/console points to */
702 tty = strrchr(*active, ' ');
708 if (streq(tty, "tty0")) {
711 /* Get the active VC (e.g. tty1) */
712 if (read_one_line_file("/sys/class/tty/tty0/active", &tmp) >= 0) {
721 int get_kernel_consoles(char ***consoles) {
722 _cleanup_strv_free_ char **con = NULL;
723 _cleanup_free_ char *line = NULL;
729 r = read_one_line_file("/sys/class/tty/console/active", &line);
735 _cleanup_free_ char *tty = NULL;
738 r = extract_first_word(&active, &tty, NULL, 0);
744 if (streq(tty, "tty0")) {
746 r = read_one_line_file("/sys/class/tty/tty0/active", &tty);
751 path = strappend("/dev/", tty);
755 if (access(path, F_OK) < 0) {
756 log_debug_errno(errno, "Console device %s is not accessible, skipping: %m", path);
761 r = strv_consume(&con, path);
766 if (strv_isempty(con)) {
767 log_debug("No devices found for system console");
769 r = strv_extend(&con, "/dev/console");
779 bool tty_is_vc_resolve(const char *tty) {
780 _cleanup_free_ char *active = NULL;
784 if (startswith(tty, "/dev/"))
787 if (streq(tty, "console")) {
788 tty = resolve_dev_console(&active);
793 return tty_is_vc(tty);
796 const char *default_term_for_tty(const char *tty) {
797 return tty && tty_is_vc_resolve(tty) ? "linux" : "vt220";
801 int fd_columns(int fd) {
802 struct winsize ws = {};
804 if (ioctl(fd, TIOCGWINSZ, &ws) < 0)
813 unsigned columns(void) {
817 if (_likely_(cached_columns > 0))
818 return cached_columns;
821 e = getenv("COLUMNS");
823 (void) safe_atoi(e, &c);
826 c = fd_columns(STDOUT_FILENO);
832 return cached_columns;
835 int fd_lines(int fd) {
836 struct winsize ws = {};
838 if (ioctl(fd, TIOCGWINSZ, &ws) < 0)
847 unsigned lines(void) {
851 if (_likely_(cached_lines > 0))
857 (void) safe_atoi(e, &l);
860 l = fd_lines(STDOUT_FILENO);
869 /* intended to be used as a SIGWINCH sighandler */
870 #if 0 /// UNNEEDED by elogind
871 void columns_lines_cache_reset(int signum) {
878 static int cached_on_tty = -1;
880 if (_unlikely_(cached_on_tty < 0))
881 cached_on_tty = isatty(STDOUT_FILENO) > 0;
883 return cached_on_tty;
886 int make_stdio(int fd) {
891 r = dup2(fd, STDIN_FILENO);
892 s = dup2(fd, STDOUT_FILENO);
893 t = dup2(fd, STDERR_FILENO);
898 if (r < 0 || s < 0 || t < 0)
901 /* Explicitly unset O_CLOEXEC, since if fd was < 3, then
902 * dup2() was a NOP and the bit hence possibly set. */
903 stdio_unset_cloexec();
908 int make_null_stdio(void) {
911 null_fd = open("/dev/null", O_RDWR|O_NOCTTY);
915 return make_stdio(null_fd);
918 int getttyname_malloc(int fd, char **ret) {
928 r = ttyname_r(fd, path, sizeof(path));
933 p = startswith(path, "/dev/");
934 c = strdup(p ?: path);
951 int getttyname_harder(int fd, char **r) {
955 k = getttyname_malloc(fd, &s);
959 if (streq(s, "tty")) {
961 return get_ctty(0, NULL, r);
968 int get_ctty_devnr(pid_t pid, dev_t *d) {
970 _cleanup_free_ char *line = NULL;
976 p = procfs_file_alloca(pid, "stat");
977 r = read_one_line_file(p, &line);
981 p = strrchr(line, ')');
996 if (major(ttynr) == 0 && minor(ttynr) == 0)
1005 int get_ctty(pid_t pid, dev_t *_devnr, char **r) {
1006 char fn[sizeof("/dev/char/")-1 + 2*DECIMAL_STR_MAX(unsigned) + 1 + 1], *b = NULL;
1007 _cleanup_free_ char *s = NULL;
1014 k = get_ctty_devnr(pid, &devnr);
1018 sprintf(fn, "/dev/char/%u:%u", major(devnr), minor(devnr));
1020 k = readlink_malloc(fn, &s);
1026 /* This is an ugly hack */
1027 if (major(devnr) == 136) {
1028 if (asprintf(&b, "pts/%u", minor(devnr)) < 0)
1031 /* Probably something like the ptys which have no
1032 * symlink in /dev/char. Let's return something
1033 * vaguely useful. */
1040 if (startswith(s, "/dev/"))
1042 else if (startswith(s, "../"))
1059 #if 0 /// UNNEEDED by elogind
1060 int ptsname_malloc(int fd, char **ret) {
1073 if (ptsname_r(fd, c, l) == 0) {
1077 if (errno != ERANGE) {
1087 int ptsname_namespace(int pty, char **ret) {
1090 /* Like ptsname(), but doesn't assume that the path is
1091 * accessible in the local namespace. */
1093 r = ioctl(pty, TIOCGPTN, &no);
1100 if (asprintf(ret, "/dev/pts/%i", no) < 0)
1106 int openpt_in_namespace(pid_t pid, int flags) {
1107 _cleanup_close_ int pidnsfd = -1, mntnsfd = -1, usernsfd = -1, rootfd = -1;
1108 _cleanup_close_pair_ int pair[2] = { -1, -1 };
1115 r = namespace_open(pid, &pidnsfd, &mntnsfd, NULL, &usernsfd, &rootfd);
1119 if (socketpair(AF_UNIX, SOCK_DGRAM, 0, pair) < 0)
1129 pair[0] = safe_close(pair[0]);
1131 r = namespace_enter(pidnsfd, mntnsfd, -1, usernsfd, rootfd);
1133 _exit(EXIT_FAILURE);
1135 master = posix_openpt(flags|O_NOCTTY|O_CLOEXEC);
1137 _exit(EXIT_FAILURE);
1139 if (unlockpt(master) < 0)
1140 _exit(EXIT_FAILURE);
1142 if (send_one_fd(pair[1], master, 0) < 0)
1143 _exit(EXIT_FAILURE);
1145 _exit(EXIT_SUCCESS);
1148 pair[1] = safe_close(pair[1]);
1150 r = wait_for_terminate(child, &si);
1153 if (si.si_code != CLD_EXITED || si.si_status != EXIT_SUCCESS)
1156 return receive_one_fd(pair[0], 0);
1159 int open_terminal_in_namespace(pid_t pid, const char *name, int mode) {
1160 _cleanup_close_ int pidnsfd = -1, mntnsfd = -1, usernsfd = -1, rootfd = -1;
1161 _cleanup_close_pair_ int pair[2] = { -1, -1 };
1166 r = namespace_open(pid, &pidnsfd, &mntnsfd, NULL, &usernsfd, &rootfd);
1170 if (socketpair(AF_UNIX, SOCK_DGRAM, 0, pair) < 0)
1180 pair[0] = safe_close(pair[0]);
1182 r = namespace_enter(pidnsfd, mntnsfd, -1, usernsfd, rootfd);
1184 _exit(EXIT_FAILURE);
1186 master = open_terminal(name, mode|O_NOCTTY|O_CLOEXEC);
1188 _exit(EXIT_FAILURE);
1190 if (send_one_fd(pair[1], master, 0) < 0)
1191 _exit(EXIT_FAILURE);
1193 _exit(EXIT_SUCCESS);
1196 pair[1] = safe_close(pair[1]);
1198 r = wait_for_terminate(child, &si);
1201 if (si.si_code != CLD_EXITED || si.si_status != EXIT_SUCCESS)
1204 return receive_one_fd(pair[0], 0);
1208 static bool getenv_terminal_is_dumb(void) {
1215 return streq(e, "dumb");
1218 bool terminal_is_dumb(void) {
1222 return getenv_terminal_is_dumb();
1225 bool colors_enabled(void) {
1226 static int enabled = -1;
1228 if (_unlikely_(enabled < 0)) {
1229 #if 0 /// elogind does not allow such forcing, and we are never init!
1232 val = getenv_bool("SYSTEMD_COLORS");
1235 else if (getpid() == 1)
1236 /* PID1 outputs to the console without holding it open all the time */
1237 enabled = !getenv_terminal_is_dumb();
1240 enabled = !terminal_is_dumb();