From 55944e5e40b1be2afc4855d8d2baf4b73d1876b5 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 10 Apr 2024 22:49:52 +0200 Subject: Adding upstream version 255.4. Signed-off-by: Daniel Baumann --- src/basic/terminal-util.c | 1553 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1553 insertions(+) create mode 100644 src/basic/terminal-util.c (limited to 'src/basic/terminal-util.c') diff --git a/src/basic/terminal-util.c b/src/basic/terminal-util.c new file mode 100644 index 0000000..3355b74 --- /dev/null +++ b/src/basic/terminal-util.c @@ -0,0 +1,1553 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "alloc-util.h" +#include "constants.h" +#include "devnum-util.h" +#include "env-util.h" +#include "fd-util.h" +#include "fileio.h" +#include "fs-util.h" +#include "inotify-util.h" +#include "io-util.h" +#include "log.h" +#include "macro.h" +#include "namespace-util.h" +#include "parse-util.h" +#include "path-util.h" +#include "proc-cmdline.h" +#include "process-util.h" +#include "socket-util.h" +#include "stat-util.h" +#include "stdio-util.h" +#include "string-util.h" +#include "strv.h" +#include "terminal-util.h" +#include "time-util.h" +#include "user-util.h" + +static volatile unsigned cached_columns = 0; +static volatile unsigned cached_lines = 0; + +static volatile int cached_on_tty = -1; +static volatile int cached_on_dev_null = -1; +static volatile int cached_color_mode = _COLOR_INVALID; +static volatile int cached_underline_enabled = -1; + +int chvt(int vt) { + _cleanup_close_ int fd = -EBADF; + + /* Switch to the specified vt number. If the VT is specified <= 0 switch to the VT the kernel log messages go, + * if that's configured. */ + + fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK); + if (fd < 0) + return -errno; + + if (vt <= 0) { + int tiocl[2] = { + TIOCL_GETKMSGREDIRECT, + 0 + }; + + if (ioctl(fd, TIOCLINUX, tiocl) < 0) + return -errno; + + vt = tiocl[0] <= 0 ? 1 : tiocl[0]; + } + + return RET_NERRNO(ioctl(fd, VT_ACTIVATE, vt)); +} + +int read_one_char(FILE *f, char *ret, usec_t t, bool *need_nl) { + _cleanup_free_ char *line = NULL; + struct termios old_termios; + int r, fd; + + assert(f); + assert(ret); + + /* If this is a terminal, then switch canonical mode off, so that we can read a single + * character. (Note that fmemopen() streams do not have an fd associated with them, let's handle that + * nicely.) */ + fd = fileno(f); + if (fd >= 0 && tcgetattr(fd, &old_termios) >= 0) { + struct termios new_termios = old_termios; + + new_termios.c_lflag &= ~ICANON; + new_termios.c_cc[VMIN] = 1; + new_termios.c_cc[VTIME] = 0; + + if (tcsetattr(fd, TCSADRAIN, &new_termios) >= 0) { + char c; + + if (t != USEC_INFINITY) { + if (fd_wait_for_event(fd, POLLIN, t) <= 0) { + (void) tcsetattr(fd, TCSADRAIN, &old_termios); + return -ETIMEDOUT; + } + } + + r = safe_fgetc(f, &c); + (void) tcsetattr(fd, TCSADRAIN, &old_termios); + if (r < 0) + return r; + if (r == 0) + return -EIO; + + if (need_nl) + *need_nl = c != '\n'; + + *ret = c; + return 0; + } + } + + if (t != USEC_INFINITY && fd > 0) { + /* Let's wait the specified amount of time for input. When we have no fd we skip this, under + * the assumption that this is an fmemopen() stream or so where waiting doesn't make sense + * anyway, as the data is either already in the stream or cannot possible be placed there + * while we access the stream */ + + if (fd_wait_for_event(fd, POLLIN, t) <= 0) + return -ETIMEDOUT; + } + + /* If this is not a terminal, then read a full line instead */ + + r = read_line(f, 16, &line); /* longer than necessary, to eat up UTF-8 chars/vt100 key sequences */ + if (r < 0) + return r; + if (r == 0) + return -EIO; + + if (strlen(line) != 1) + return -EBADMSG; + + if (need_nl) + *need_nl = false; + + *ret = line[0]; + return 0; +} + +#define DEFAULT_ASK_REFRESH_USEC (2*USEC_PER_SEC) + +int ask_char(char *ret, const char *replies, const char *fmt, ...) { + int r; + + assert(ret); + assert(replies); + assert(fmt); + + for (;;) { + va_list ap; + char c; + bool need_nl = true; + + fputs(ansi_highlight(), stdout); + + putchar('\r'); + + va_start(ap, fmt); + vprintf(fmt, ap); + va_end(ap); + + fputs(ansi_normal(), stdout); + + fflush(stdout); + + r = read_one_char(stdin, &c, DEFAULT_ASK_REFRESH_USEC, &need_nl); + if (r < 0) { + + if (r == -ETIMEDOUT) + continue; + + if (r == -EBADMSG) { + puts("Bad input, please try again."); + continue; + } + + putchar('\n'); + return r; + } + + if (need_nl) + putchar('\n'); + + if (strchr(replies, c)) { + *ret = c; + return 0; + } + + puts("Read unexpected character, please try again."); + } +} + +int ask_string(char **ret, const char *text, ...) { + _cleanup_free_ char *line = NULL; + va_list ap; + int r; + + assert(ret); + assert(text); + + fputs(ansi_highlight(), stdout); + + va_start(ap, text); + vprintf(text, ap); + va_end(ap); + + fputs(ansi_normal(), stdout); + + fflush(stdout); + + r = read_line(stdin, LONG_LINE_MAX, &line); + if (r < 0) + return r; + if (r == 0) + return -EIO; + + *ret = TAKE_PTR(line); + return 0; +} + +int reset_terminal_fd(int fd, bool switch_to_text) { + struct termios termios; + int r; + + /* Set terminal to some sane defaults */ + + assert(fd >= 0); + + if (isatty(fd) < 1) + return log_debug_errno(errno, "Asked to reset a terminal that actually isn't a terminal: %m"); + + /* We leave locked terminal attributes untouched, so that Plymouth may set whatever it wants to set, + * and we don't interfere with that. */ + + /* Disable exclusive mode, just in case */ + if (ioctl(fd, TIOCNXCL) < 0) + log_debug_errno(errno, "TIOCNXCL ioctl failed on TTY, ignoring: %m"); + + /* Switch to text mode */ + if (switch_to_text) + if (ioctl(fd, KDSETMODE, KD_TEXT) < 0) + log_debug_errno(errno, "KDSETMODE ioctl for switching to text mode failed on TTY, ignoring: %m"); + + + /* Set default keyboard mode */ + r = vt_reset_keyboard(fd); + if (r < 0) + log_debug_errno(r, "Failed to reset VT keyboard, ignoring: %m"); + + if (tcgetattr(fd, &termios) < 0) { + r = log_debug_errno(errno, "Failed to get terminal parameters: %m"); + goto finish; + } + + /* We only reset the stuff that matters to the software. How + * hardware is set up we don't touch assuming that somebody + * else will do that for us */ + + termios.c_iflag &= ~(IGNBRK | BRKINT | ISTRIP | INLCR | IGNCR | IUCLC); + termios.c_iflag |= ICRNL | IMAXBEL | IUTF8; + termios.c_oflag |= ONLCR | OPOST; + termios.c_cflag |= CREAD; + termios.c_lflag = ISIG | ICANON | IEXTEN | ECHO | ECHOE | ECHOK | ECHOCTL | ECHOKE; + + termios.c_cc[VINTR] = 03; /* ^C */ + termios.c_cc[VQUIT] = 034; /* ^\ */ + termios.c_cc[VERASE] = 0177; + termios.c_cc[VKILL] = 025; /* ^X */ + termios.c_cc[VEOF] = 04; /* ^D */ + termios.c_cc[VSTART] = 021; /* ^Q */ + termios.c_cc[VSTOP] = 023; /* ^S */ + termios.c_cc[VSUSP] = 032; /* ^Z */ + termios.c_cc[VLNEXT] = 026; /* ^V */ + termios.c_cc[VWERASE] = 027; /* ^W */ + termios.c_cc[VREPRINT] = 022; /* ^R */ + termios.c_cc[VEOL] = 0; + termios.c_cc[VEOL2] = 0; + + termios.c_cc[VTIME] = 0; + termios.c_cc[VMIN] = 1; + + r = RET_NERRNO(tcsetattr(fd, TCSANOW, &termios)); + +finish: + /* Just in case, flush all crap out */ + (void) tcflush(fd, TCIOFLUSH); + + return r; +} + +int reset_terminal(const char *name) { + _cleanup_close_ int fd = -EBADF; + + /* We open the terminal with O_NONBLOCK here, to ensure we + * don't block on carrier if this is a terminal with carrier + * configured. */ + + fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK); + if (fd < 0) + return fd; + + return reset_terminal_fd(fd, true); +} + +int open_terminal(const char *name, int mode) { + _cleanup_close_ int fd = -EBADF; + unsigned c = 0; + + /* + * If a TTY is in the process of being closed opening it might cause EIO. This is horribly awful, but + * unlikely to be changed in the kernel. Hence we work around this problem by retrying a couple of + * times. + * + * https://bugs.launchpad.net/ubuntu/+source/linux/+bug/554172/comments/245 + */ + + if (mode & O_CREAT) + return -EINVAL; + + for (;;) { + fd = open(name, mode, 0); + if (fd >= 0) + break; + + if (errno != EIO) + return -errno; + + /* Max 1s in total */ + if (c >= 20) + return -errno; + + (void) usleep_safe(50 * USEC_PER_MSEC); + c++; + } + + if (isatty(fd) < 1) + return negative_errno(); + + return TAKE_FD(fd); +} + +int acquire_terminal( + const char *name, + AcquireTerminalFlags flags, + usec_t timeout) { + + _cleanup_close_ int notify = -EBADF, fd = -EBADF; + usec_t ts = USEC_INFINITY; + int r, wd = -1; + + assert(name); + assert(IN_SET(flags & ~ACQUIRE_TERMINAL_PERMISSIVE, ACQUIRE_TERMINAL_TRY, ACQUIRE_TERMINAL_FORCE, ACQUIRE_TERMINAL_WAIT)); + + /* We use inotify to be notified when the tty is closed. We create the watch before checking if we can actually + * acquire it, so that we don't lose any event. + * + * Note: strictly speaking this actually watches for the device being closed, it does *not* really watch + * whether a tty loses its controlling process. However, unless some rogue process uses TIOCNOTTY on /dev/tty + * *after* closing its tty otherwise this will not become a problem. As long as the administrator makes sure to + * not configure any service on the same tty as an untrusted user this should not be a problem. (Which they + * probably should not do anyway.) */ + + if ((flags & ~ACQUIRE_TERMINAL_PERMISSIVE) == ACQUIRE_TERMINAL_WAIT) { + notify = inotify_init1(IN_CLOEXEC | (timeout != USEC_INFINITY ? IN_NONBLOCK : 0)); + if (notify < 0) + return -errno; + + wd = inotify_add_watch(notify, name, IN_CLOSE); + if (wd < 0) + return -errno; + + if (timeout != USEC_INFINITY) + ts = now(CLOCK_MONOTONIC); + } + + for (;;) { + struct sigaction sa_old, sa_new = { + .sa_handler = SIG_IGN, + .sa_flags = SA_RESTART, + }; + + if (notify >= 0) { + r = flush_fd(notify); + if (r < 0) + return r; + } + + /* We pass here O_NOCTTY only so that we can check the return value TIOCSCTTY and have a reliable way + * to figure out if we successfully became the controlling process of the tty */ + fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC); + if (fd < 0) + return fd; + + /* Temporarily ignore SIGHUP, so that we don't get SIGHUP'ed if we already own the tty. */ + assert_se(sigaction(SIGHUP, &sa_new, &sa_old) == 0); + + /* First, try to get the tty */ + r = RET_NERRNO(ioctl(fd, TIOCSCTTY, (flags & ~ACQUIRE_TERMINAL_PERMISSIVE) == ACQUIRE_TERMINAL_FORCE)); + + /* Reset signal handler to old value */ + assert_se(sigaction(SIGHUP, &sa_old, NULL) == 0); + + /* Success? Exit the loop now! */ + if (r >= 0) + break; + + /* Any failure besides -EPERM? Fail, regardless of the mode. */ + if (r != -EPERM) + return r; + + if (flags & ACQUIRE_TERMINAL_PERMISSIVE) /* If we are in permissive mode, then EPERM is fine, turn this + * into a success. Note that EPERM is also returned if we + * already are the owner of the TTY. */ + break; + + if (flags != ACQUIRE_TERMINAL_WAIT) /* If we are in TRY or FORCE mode, then propagate EPERM as EPERM */ + return r; + + assert(notify >= 0); + assert(wd >= 0); + + for (;;) { + union inotify_event_buffer buffer; + ssize_t l; + + if (timeout != USEC_INFINITY) { + usec_t n; + + assert(ts != USEC_INFINITY); + + n = usec_sub_unsigned(now(CLOCK_MONOTONIC), ts); + if (n >= timeout) + return -ETIMEDOUT; + + r = fd_wait_for_event(notify, POLLIN, usec_sub_unsigned(timeout, n)); + if (r < 0) + return r; + if (r == 0) + return -ETIMEDOUT; + } + + l = read(notify, &buffer, sizeof(buffer)); + if (l < 0) { + if (ERRNO_IS_TRANSIENT(errno)) + continue; + + return -errno; + } + + FOREACH_INOTIFY_EVENT(e, buffer, l) { + if (e->mask & IN_Q_OVERFLOW) /* If we hit an inotify queue overflow, simply check if the terminal is up for grabs now. */ + break; + + if (e->wd != wd || !(e->mask & IN_CLOSE)) /* Safety checks */ + return -EIO; + } + + break; + } + + /* We close the tty fd here since if the old session ended our handle will be dead. It's important that + * we do this after sleeping, so that we don't enter an endless loop. */ + fd = safe_close(fd); + } + + return TAKE_FD(fd); +} + +int release_terminal(void) { + static const struct sigaction sa_new = { + .sa_handler = SIG_IGN, + .sa_flags = SA_RESTART, + }; + + _cleanup_close_ int fd = -EBADF; + struct sigaction sa_old; + int r; + + fd = open("/dev/tty", O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK); + if (fd < 0) + return -errno; + + /* Temporarily ignore SIGHUP, so that we don't get SIGHUP'ed + * by our own TIOCNOTTY */ + assert_se(sigaction(SIGHUP, &sa_new, &sa_old) == 0); + + r = RET_NERRNO(ioctl(fd, TIOCNOTTY)); + + assert_se(sigaction(SIGHUP, &sa_old, NULL) == 0); + + return r; +} + +int terminal_vhangup_fd(int fd) { + assert(fd >= 0); + return RET_NERRNO(ioctl(fd, TIOCVHANGUP)); +} + +int terminal_vhangup(const char *name) { + _cleanup_close_ int fd = -EBADF; + + fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK); + if (fd < 0) + return fd; + + return terminal_vhangup_fd(fd); +} + +int vt_disallocate(const char *name) { + const char *e; + int r; + + /* Deallocate the VT if possible. If not possible + * (i.e. because it is the active one), at least clear it + * entirely (including the scrollback buffer). */ + + e = path_startswith(name, "/dev/"); + if (!e) + return -EINVAL; + + if (tty_is_vc(name)) { + _cleanup_close_ int fd = -EBADF; + unsigned u; + const char *n; + + n = startswith(e, "tty"); + if (!n) + return -EINVAL; + + r = safe_atou(n, &u); + if (r < 0) + return r; + + if (u <= 0) + return -EINVAL; + + /* Try to deallocate */ + fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK); + if (fd < 0) + return fd; + + r = ioctl(fd, VT_DISALLOCATE, u); + if (r >= 0) + return 0; + if (errno != EBUSY) + return -errno; + } + + /* So this is not a VT (in which case we cannot deallocate it), + * or we failed to deallocate. Let's at least clear the screen. */ + + _cleanup_close_ int fd2 = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC); + if (fd2 < 0) + return fd2; + + (void) loop_write(fd2, + "\033[r" /* clear scrolling region */ + "\033[H" /* move home */ + "\033[3J", /* clear screen including scrollback, requires Linux 2.6.40 */ + 10); + return 0; +} + +int make_console_stdio(void) { + int fd, r; + + /* Make /dev/console the controlling terminal and stdin/stdout/stderr, if we can. If we can't use + * /dev/null instead. This is particularly useful if /dev/console is turned off, e.g. if console=null + * is specified on the kernel command line. */ + + fd = acquire_terminal("/dev/console", ACQUIRE_TERMINAL_FORCE|ACQUIRE_TERMINAL_PERMISSIVE, USEC_INFINITY); + if (fd < 0) { + log_warning_errno(fd, "Failed to acquire terminal, using /dev/null stdin/stdout/stderr instead: %m"); + + r = make_null_stdio(); + if (r < 0) + return log_error_errno(r, "Failed to make /dev/null stdin/stdout/stderr: %m"); + + } else { + unsigned rows, cols; + + r = reset_terminal_fd(fd, /* switch_to_text= */ true); + if (r < 0) + log_warning_errno(r, "Failed to reset terminal, ignoring: %m"); + + r = proc_cmdline_tty_size("/dev/console", &rows, &cols); + if (r < 0) + log_warning_errno(r, "Failed to get terminal size, ignoring: %m"); + else { + r = terminal_set_size_fd(fd, NULL, rows, cols); + if (r < 0) + log_warning_errno(r, "Failed to set terminal size, ignoring: %m"); + } + + r = rearrange_stdio(fd, fd, fd); /* This invalidates 'fd' both on success and on failure. */ + if (r < 0) + return log_error_errno(r, "Failed to make terminal stdin/stdout/stderr: %m"); + } + + reset_terminal_feature_caches(); + return 0; +} + +bool tty_is_vc(const char *tty) { + assert(tty); + + return vtnr_from_tty(tty) >= 0; +} + +bool tty_is_console(const char *tty) { + assert(tty); + + return streq(skip_dev_prefix(tty), "console"); +} + +int vtnr_from_tty(const char *tty) { + int i, r; + + assert(tty); + + tty = skip_dev_prefix(tty); + + if (!startswith(tty, "tty") ) + return -EINVAL; + + if (!ascii_isdigit(tty[3])) + return -EINVAL; + + r = safe_atoi(tty+3, &i); + if (r < 0) + return r; + + if (i < 0 || i > 63) + return -EINVAL; + + return i; +} + + int resolve_dev_console(char **ret) { + _cleanup_free_ char *active = NULL; + char *tty; + int r; + + assert(ret); + + /* Resolve where /dev/console is pointing to, if /sys is actually ours (i.e. not read-only-mounted which is a + * sign for container setups) */ + + if (path_is_read_only_fs("/sys") > 0) + return -ENOMEDIUM; + + r = read_one_line_file("/sys/class/tty/console/active", &active); + if (r < 0) + return r; + + /* If multiple log outputs are configured the last one is what /dev/console points to */ + tty = strrchr(active, ' '); + if (tty) + tty++; + else + tty = active; + + if (streq(tty, "tty0")) { + active = mfree(active); + + /* Get the active VC (e.g. tty1) */ + r = read_one_line_file("/sys/class/tty/tty0/active", &active); + if (r < 0) + return r; + + tty = active; + } + + if (tty == active) + *ret = TAKE_PTR(active); + else { + char *tmp; + + tmp = strdup(tty); + if (!tmp) + return -ENOMEM; + + *ret = tmp; + } + + return 0; +} + +int get_kernel_consoles(char ***ret) { + _cleanup_strv_free_ char **l = NULL; + _cleanup_free_ char *line = NULL; + const char *p; + int r; + + assert(ret); + + /* If /sys is mounted read-only this means we are running in some kind of container environment. In that + * case /sys would reflect the host system, not us, hence ignore the data we can read from it. */ + if (path_is_read_only_fs("/sys") > 0) + goto fallback; + + r = read_one_line_file("/sys/class/tty/console/active", &line); + if (r < 0) + return r; + + p = line; + for (;;) { + _cleanup_free_ char *tty = NULL, *path = NULL; + + r = extract_first_word(&p, &tty, NULL, 0); + if (r < 0) + return r; + if (r == 0) + break; + + if (streq(tty, "tty0")) { + tty = mfree(tty); + r = read_one_line_file("/sys/class/tty/tty0/active", &tty); + if (r < 0) + return r; + } + + path = path_join("/dev", tty); + if (!path) + return -ENOMEM; + + if (access(path, F_OK) < 0) { + log_debug_errno(errno, "Console device %s is not accessible, skipping: %m", path); + continue; + } + + r = strv_consume(&l, TAKE_PTR(path)); + if (r < 0) + return r; + } + + if (strv_isempty(l)) { + log_debug("No devices found for system console"); + goto fallback; + } + + *ret = TAKE_PTR(l); + + return 0; + +fallback: + r = strv_extend(&l, "/dev/console"); + if (r < 0) + return r; + + *ret = TAKE_PTR(l); + + return 0; +} + +bool tty_is_vc_resolve(const char *tty) { + _cleanup_free_ char *resolved = NULL; + + assert(tty); + + tty = skip_dev_prefix(tty); + + if (streq(tty, "console")) { + if (resolve_dev_console(&resolved) < 0) + return false; + + tty = resolved; + } + + return tty_is_vc(tty); +} + +const char *default_term_for_tty(const char *tty) { + return tty && tty_is_vc_resolve(tty) ? "linux" : "vt220"; +} + +int fd_columns(int fd) { + struct winsize ws = {}; + + if (fd < 0) + return -EBADF; + + if (ioctl(fd, TIOCGWINSZ, &ws) < 0) + return -errno; + + if (ws.ws_col <= 0) + return -EIO; + + return ws.ws_col; +} + +unsigned columns(void) { + const char *e; + int c; + + if (cached_columns > 0) + return cached_columns; + + c = 0; + e = getenv("COLUMNS"); + if (e) + (void) safe_atoi(e, &c); + + if (c <= 0 || c > USHRT_MAX) { + c = fd_columns(STDOUT_FILENO); + if (c <= 0) + c = 80; + } + + cached_columns = c; + return cached_columns; +} + +int fd_lines(int fd) { + struct winsize ws = {}; + + if (fd < 0) + return -EBADF; + + if (ioctl(fd, TIOCGWINSZ, &ws) < 0) + return -errno; + + if (ws.ws_row <= 0) + return -EIO; + + return ws.ws_row; +} + +unsigned lines(void) { + const char *e; + int l; + + if (cached_lines > 0) + return cached_lines; + + l = 0; + e = getenv("LINES"); + if (e) + (void) safe_atoi(e, &l); + + if (l <= 0 || l > USHRT_MAX) { + l = fd_lines(STDOUT_FILENO); + if (l <= 0) + l = 24; + } + + cached_lines = l; + return cached_lines; +} + +int terminal_set_size_fd(int fd, const char *ident, unsigned rows, unsigned cols) { + struct winsize ws; + + if (rows == UINT_MAX && cols == UINT_MAX) + return 0; + + if (ioctl(fd, TIOCGWINSZ, &ws) < 0) + return log_debug_errno(errno, + "TIOCGWINSZ ioctl for getting %s size failed, not setting terminal size: %m", + ident ?: "TTY"); + + if (rows == UINT_MAX) + rows = ws.ws_row; + else if (rows > USHRT_MAX) + rows = USHRT_MAX; + + if (cols == UINT_MAX) + cols = ws.ws_col; + else if (cols > USHRT_MAX) + cols = USHRT_MAX; + + if (rows == ws.ws_row && cols == ws.ws_col) + return 0; + + ws.ws_row = rows; + ws.ws_col = cols; + + if (ioctl(fd, TIOCSWINSZ, &ws) < 0) + return log_debug_errno(errno, "TIOCSWINSZ ioctl for setting %s size failed: %m", ident ?: "TTY"); + + return 0; +} + +int proc_cmdline_tty_size(const char *tty, unsigned *ret_rows, unsigned *ret_cols) { + _cleanup_free_ char *rowskey = NULL, *rowsvalue = NULL, *colskey = NULL, *colsvalue = NULL; + unsigned rows = UINT_MAX, cols = UINT_MAX; + int r; + + assert(tty); + + if (!ret_rows && !ret_cols) + return 0; + + tty = skip_dev_prefix(tty); + if (!in_charset(tty, ALPHANUMERICAL)) + return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "%s contains non-alphanumeric characters", tty); + + rowskey = strjoin("systemd.tty.rows.", tty); + if (!rowskey) + return -ENOMEM; + + colskey = strjoin("systemd.tty.columns.", tty); + if (!colskey) + return -ENOMEM; + + r = proc_cmdline_get_key_many(/* flags = */ 0, + rowskey, &rowsvalue, + colskey, &colsvalue); + if (r < 0) + return log_debug_errno(r, "Failed to read TTY size of %s from kernel cmdline: %m", tty); + + if (rowsvalue) { + r = safe_atou(rowsvalue, &rows); + if (r < 0) + return log_debug_errno(r, "Failed to parse %s=%s: %m", rowskey, rowsvalue); + } + + if (colsvalue) { + r = safe_atou(colsvalue, &cols); + if (r < 0) + return log_debug_errno(r, "Failed to parse %s=%s: %m", colskey, colsvalue); + } + + if (ret_rows) + *ret_rows = rows; + if (ret_cols) + *ret_cols = cols; + + return 0; +} + +/* intended to be used as a SIGWINCH sighandler */ +void columns_lines_cache_reset(int signum) { + cached_columns = 0; + cached_lines = 0; +} + +void reset_terminal_feature_caches(void) { + cached_columns = 0; + cached_lines = 0; + + cached_color_mode = _COLOR_INVALID; + cached_underline_enabled = -1; + cached_on_tty = -1; + cached_on_dev_null = -1; +} + +bool on_tty(void) { + + /* We check both stdout and stderr, so that situations where pipes on the shell are used are reliably + * recognized, regardless if only the output or the errors are piped to some place. Since on_tty() is generally + * used to default to a safer, non-interactive, non-color mode of operation it's probably good to be defensive + * here, and check for both. Note that we don't check for STDIN_FILENO, because it should fine to use fancy + * terminal functionality when outputting stuff, even if the input is piped to us. */ + + if (cached_on_tty < 0) + cached_on_tty = + isatty(STDOUT_FILENO) > 0 && + isatty(STDERR_FILENO) > 0; + + return cached_on_tty; +} + +int getttyname_malloc(int fd, char **ret) { + char path[PATH_MAX], *c; /* PATH_MAX is counted *with* the trailing NUL byte */ + int r; + + assert(fd >= 0); + assert(ret); + + r = ttyname_r(fd, path, sizeof path); /* positive error */ + assert(r >= 0); + if (r == ERANGE) + return -ENAMETOOLONG; + if (r > 0) + return -r; + + c = strdup(skip_dev_prefix(path)); + if (!c) + return -ENOMEM; + + *ret = c; + return 0; +} + +int getttyname_harder(int fd, char **ret) { + _cleanup_free_ char *s = NULL; + int r; + + r = getttyname_malloc(fd, &s); + if (r < 0) + return r; + + if (streq(s, "tty")) + return get_ctty(0, NULL, ret); + + *ret = TAKE_PTR(s); + return 0; +} + +int get_ctty_devnr(pid_t pid, dev_t *d) { + int r; + _cleanup_free_ char *line = NULL; + const char *p; + unsigned long ttynr; + + assert(pid >= 0); + + p = procfs_file_alloca(pid, "stat"); + r = read_one_line_file(p, &line); + if (r < 0) + return r; + + p = strrchr(line, ')'); + if (!p) + return -EIO; + + p++; + + if (sscanf(p, " " + "%*c " /* state */ + "%*d " /* ppid */ + "%*d " /* pgrp */ + "%*d " /* session */ + "%lu ", /* ttynr */ + &ttynr) != 1) + return -EIO; + + if (devnum_is_zero(ttynr)) + return -ENXIO; + + if (d) + *d = (dev_t) ttynr; + + return 0; +} + +int get_ctty(pid_t pid, dev_t *ret_devnr, char **ret) { + char pty[STRLEN("/dev/pts/") + DECIMAL_STR_MAX(dev_t) + 1]; + _cleanup_free_ char *buf = NULL; + const char *fn = NULL, *w; + dev_t devnr; + int r; + + r = get_ctty_devnr(pid, &devnr); + if (r < 0) + return r; + + r = device_path_make_canonical(S_IFCHR, devnr, &buf); + if (r < 0) { + struct stat st; + + if (r != -ENOENT) /* No symlink for this in /dev/char/? */ + return r; + + /* Maybe this is PTY? PTY devices are not listed in /dev/char/, as they don't follow the + * Linux device model and hence device_path_make_canonical() doesn't work for them. Let's + * assume this is a PTY for a moment, and check if the device node this would then map to in + * /dev/pts/ matches the one we are looking for. This way we don't have to hardcode the major + * number (which is 136 btw), but we still rely on the fact that PTY numbers map directly to + * the minor number of the pty. */ + xsprintf(pty, "/dev/pts/%u", minor(devnr)); + + if (stat(pty, &st) < 0) { + if (errno != ENOENT) + return -errno; + + } else if (S_ISCHR(st.st_mode) && devnr == st.st_rdev) /* Bingo! */ + fn = pty; + + if (!fn) { + /* Doesn't exist, or not a PTY? Probably something similar to the PTYs which have no + * symlink in /dev/char/. Let's return something vaguely useful. */ + r = device_path_make_major_minor(S_IFCHR, devnr, &buf); + if (r < 0) + return r; + + fn = buf; + } + } else + fn = buf; + + w = path_startswith(fn, "/dev/"); + if (!w) + return -EINVAL; + + if (ret) { + _cleanup_free_ char *b = NULL; + + b = strdup(w); + if (!b) + return -ENOMEM; + + *ret = TAKE_PTR(b); + } + + if (ret_devnr) + *ret_devnr = devnr; + + return 0; +} + +int ptsname_malloc(int fd, char **ret) { + size_t l = 100; + + assert(fd >= 0); + assert(ret); + + for (;;) { + char *c; + + c = new(char, l); + if (!c) + return -ENOMEM; + + if (ptsname_r(fd, c, l) == 0) { + *ret = c; + return 0; + } + if (errno != ERANGE) { + free(c); + return -errno; + } + + free(c); + + if (l > SIZE_MAX / 2) + return -ENOMEM; + + l *= 2; + } +} + +int openpt_allocate(int flags, char **ret_slave) { + _cleanup_close_ int fd = -EBADF; + _cleanup_free_ char *p = NULL; + int r; + + fd = posix_openpt(flags|O_NOCTTY|O_CLOEXEC); + if (fd < 0) + return -errno; + + if (ret_slave) { + r = ptsname_malloc(fd, &p); + if (r < 0) + return r; + + if (!path_startswith(p, "/dev/pts/")) + return -EINVAL; + } + + if (unlockpt(fd) < 0) + return -errno; + + if (ret_slave) + *ret_slave = TAKE_PTR(p); + + return TAKE_FD(fd); +} + +static int ptsname_namespace(int pty, char **ret) { + int no = -1, r; + + /* Like ptsname(), but doesn't assume that the path is + * accessible in the local namespace. */ + + r = ioctl(pty, TIOCGPTN, &no); + if (r < 0) + return -errno; + + if (no < 0) + return -EIO; + + if (asprintf(ret, "/dev/pts/%i", no) < 0) + return -ENOMEM; + + return 0; +} + +int openpt_allocate_in_namespace(pid_t pid, int flags, char **ret_slave) { + _cleanup_close_ int pidnsfd = -EBADF, mntnsfd = -EBADF, usernsfd = -EBADF, rootfd = -EBADF, fd = -EBADF; + _cleanup_close_pair_ int pair[2] = EBADF_PAIR; + pid_t child; + int r; + + assert(pid > 0); + + r = namespace_open(pid, &pidnsfd, &mntnsfd, NULL, &usernsfd, &rootfd); + if (r < 0) + return r; + + if (socketpair(AF_UNIX, SOCK_DGRAM, 0, pair) < 0) + return -errno; + + r = namespace_fork("(sd-openptns)", "(sd-openpt)", NULL, 0, FORK_RESET_SIGNALS|FORK_DEATHSIG_SIGKILL, + pidnsfd, mntnsfd, -1, usernsfd, rootfd, &child); + if (r < 0) + return r; + if (r == 0) { + pair[0] = safe_close(pair[0]); + + fd = openpt_allocate(flags, NULL); + if (fd < 0) + _exit(EXIT_FAILURE); + + if (send_one_fd(pair[1], fd, 0) < 0) + _exit(EXIT_FAILURE); + + _exit(EXIT_SUCCESS); + } + + pair[1] = safe_close(pair[1]); + + r = wait_for_terminate_and_check("(sd-openptns)", child, 0); + if (r < 0) + return r; + if (r != EXIT_SUCCESS) + return -EIO; + + fd = receive_one_fd(pair[0], 0); + if (fd < 0) + return fd; + + if (ret_slave) { + r = ptsname_namespace(fd, ret_slave); + if (r < 0) + return r; + } + + return TAKE_FD(fd); +} + +int open_terminal_in_namespace(pid_t pid, const char *name, int mode) { + _cleanup_close_ int pidnsfd = -EBADF, mntnsfd = -EBADF, usernsfd = -EBADF, rootfd = -EBADF; + _cleanup_close_pair_ int pair[2] = EBADF_PAIR; + pid_t child; + int r; + + r = namespace_open(pid, &pidnsfd, &mntnsfd, NULL, &usernsfd, &rootfd); + if (r < 0) + return r; + + if (socketpair(AF_UNIX, SOCK_DGRAM, 0, pair) < 0) + return -errno; + + r = namespace_fork("(sd-terminalns)", "(sd-terminal)", NULL, 0, FORK_RESET_SIGNALS|FORK_DEATHSIG_SIGKILL, + pidnsfd, mntnsfd, -1, usernsfd, rootfd, &child); + if (r < 0) + return r; + if (r == 0) { + int master; + + pair[0] = safe_close(pair[0]); + + master = open_terminal(name, mode|O_NOCTTY|O_CLOEXEC); + if (master < 0) + _exit(EXIT_FAILURE); + + if (send_one_fd(pair[1], master, 0) < 0) + _exit(EXIT_FAILURE); + + _exit(EXIT_SUCCESS); + } + + pair[1] = safe_close(pair[1]); + + r = wait_for_terminate_and_check("(sd-terminalns)", child, 0); + if (r < 0) + return r; + if (r != EXIT_SUCCESS) + return -EIO; + + return receive_one_fd(pair[0], 0); +} + +static bool on_dev_null(void) { + struct stat dst, ost, est; + + if (cached_on_dev_null >= 0) + return cached_on_dev_null; + + if (stat("/dev/null", &dst) < 0 || fstat(STDOUT_FILENO, &ost) < 0 || fstat(STDERR_FILENO, &est) < 0) + cached_on_dev_null = false; + else + cached_on_dev_null = stat_inode_same(&dst, &ost) && stat_inode_same(&dst, &est); + + return cached_on_dev_null; +} + +static bool getenv_terminal_is_dumb(void) { + const char *e; + + e = getenv("TERM"); + if (!e) + return true; + + return streq(e, "dumb"); +} + +bool terminal_is_dumb(void) { + if (!on_tty() && !on_dev_null()) + return true; + + return getenv_terminal_is_dumb(); +} + +static ColorMode parse_systemd_colors(void) { + const char *e; + int r; + + e = getenv("SYSTEMD_COLORS"); + if (!e) + return _COLOR_INVALID; + if (streq(e, "16")) + return COLOR_16; + if (streq(e, "256")) + return COLOR_256; + r = parse_boolean(e); + if (r >= 0) + return r > 0 ? COLOR_ON : COLOR_OFF; + return _COLOR_INVALID; +} + +ColorMode get_color_mode(void) { + + /* Returns the mode used to choose output colors. The possible modes are COLOR_OFF for no colors, + * COLOR_16 for only the base 16 ANSI colors, COLOR_256 for more colors and COLOR_ON for unrestricted + * color output. For that we check $SYSTEMD_COLORS first (which is the explicit way to + * change the mode). If that didn't work we turn colors off unless we are on a TTY. And if we are on a TTY + * we turn it off if $TERM is set to "dumb". There's one special tweak though: if we are PID 1 then we do not + * check whether we are connected to a TTY, because we don't keep /dev/console open continuously due to fear + * of SAK, and hence things are a bit weird. */ + ColorMode m; + + if (cached_color_mode < 0) { + m = parse_systemd_colors(); + if (m >= 0) + cached_color_mode = m; + else if (getenv("NO_COLOR")) + /* We only check for the presence of the variable; value is ignored. */ + cached_color_mode = COLOR_OFF; + + else if (getpid_cached() == 1) { + /* PID1 outputs to the console without holding it open all the time. + * + * Note that the Linux console can only display 16 colors. We still enable 256 color + * mode even for PID1 output though (which typically goes to the Linux console), + * since the Linux console is able to parse the 256 color sequences and automatically + * map them to the closest color in the 16 color palette (since kernel 3.16). Doing + * 256 colors is nice for people who invoke systemd in a container or via a serial + * link or such, and use a true 256 color terminal to do so. */ + if (getenv_terminal_is_dumb()) + cached_color_mode = COLOR_OFF; + } else { + if (terminal_is_dumb()) + cached_color_mode = COLOR_OFF; + } + + if (cached_color_mode < 0) { + /* We failed to figure out any reason to *disable* colors. + * Let's see how many colors we shall use. */ + if (STRPTR_IN_SET(getenv("COLORTERM"), + "truecolor", + "24bit")) + cached_color_mode = COLOR_24BIT; + else + cached_color_mode = COLOR_256; + } + } + + return cached_color_mode; +} + +bool dev_console_colors_enabled(void) { + _cleanup_free_ char *s = NULL; + ColorMode m; + + /* Returns true if we assume that color is supported on /dev/console. + * + * For that we first check if we explicitly got told to use colors or not, by checking $SYSTEMD_COLORS. If that + * isn't set we check whether PID 1 has $TERM set, and if not, whether TERM is set on the kernel command + * line. If we find $TERM set we assume color if it's not set to "dumb", similarly to how regular + * colors_enabled() operates. */ + + m = parse_systemd_colors(); + if (m >= 0) + return m; + + if (getenv("NO_COLOR")) + return false; + + if (getenv_for_pid(1, "TERM", &s) <= 0) + (void) proc_cmdline_get_key("TERM", 0, &s); + + return !streq_ptr(s, "dumb"); +} + +bool underline_enabled(void) { + + if (cached_underline_enabled < 0) { + + /* The Linux console doesn't support underlining, turn it off, but only there. */ + + if (colors_enabled()) + cached_underline_enabled = !streq_ptr(getenv("TERM"), "linux"); + else + cached_underline_enabled = false; + } + + return cached_underline_enabled; +} + +int vt_default_utf8(void) { + _cleanup_free_ char *b = NULL; + int r; + + /* Read the default VT UTF8 setting from the kernel */ + + r = read_one_line_file("/sys/module/vt/parameters/default_utf8", &b); + if (r < 0) + return r; + + return parse_boolean(b); +} + +int vt_reset_keyboard(int fd) { + int kb; + + /* If we can't read the default, then default to unicode. It's 2017 after all. */ + kb = vt_default_utf8() != 0 ? K_UNICODE : K_XLATE; + + return RET_NERRNO(ioctl(fd, KDSKBMODE, kb)); +} + +int vt_restore(int fd) { + static const struct vt_mode mode = { + .mode = VT_AUTO, + }; + int r, q = 0; + + if (isatty(fd) < 1) + return log_debug_errno(errno, "Asked to restore the VT for an fd that does not refer to a terminal: %m"); + + if (ioctl(fd, KDSETMODE, KD_TEXT) < 0) + q = log_debug_errno(errno, "Failed to set VT in text mode, ignoring: %m"); + + r = vt_reset_keyboard(fd); + if (r < 0) { + log_debug_errno(r, "Failed to reset keyboard mode, ignoring: %m"); + if (q >= 0) + q = r; + } + + if (ioctl(fd, VT_SETMODE, &mode) < 0) { + log_debug_errno(errno, "Failed to set VT_AUTO mode, ignoring: %m"); + if (q >= 0) + q = -errno; + } + + r = fchmod_and_chown(fd, TTY_MODE, 0, GID_INVALID); + if (r < 0) { + log_debug_errno(r, "Failed to chmod()/chown() VT, ignoring: %m"); + if (q >= 0) + q = r; + } + + return q; +} + +int vt_release(int fd, bool restore) { + assert(fd >= 0); + + /* This function releases the VT by acknowledging the VT-switch signal + * sent by the kernel and optionally reset the VT in text and auto + * VT-switching modes. */ + + if (isatty(fd) < 1) + return log_debug_errno(errno, "Asked to release the VT for an fd that does not refer to a terminal: %m"); + + if (ioctl(fd, VT_RELDISP, 1) < 0) + return -errno; + + if (restore) + return vt_restore(fd); + + return 0; +} + +void get_log_colors(int priority, const char **on, const char **off, const char **highlight) { + /* Note that this will initialize output variables only when there's something to output. + * The caller must pre-initialize to "" or NULL as appropriate. */ + + if (priority <= LOG_ERR) { + if (on) + *on = ansi_highlight_red(); + if (off) + *off = ansi_normal(); + if (highlight) + *highlight = ansi_highlight(); + + } else if (priority <= LOG_WARNING) { + if (on) + *on = ansi_highlight_yellow(); + if (off) + *off = ansi_normal(); + if (highlight) + *highlight = ansi_highlight(); + + } else if (priority <= LOG_NOTICE) { + if (on) + *on = ansi_highlight(); + if (off) + *off = ansi_normal(); + if (highlight) + *highlight = ansi_highlight_red(); + + } else if (priority >= LOG_DEBUG) { + if (on) + *on = ansi_grey(); + if (off) + *off = ansi_normal(); + if (highlight) + *highlight = ansi_highlight_red(); + } +} + +int set_terminal_cursor_position(int fd, unsigned int row, unsigned int column) { + int r; + char cursor_position[STRLEN("\x1B[") + DECIMAL_STR_MAX(int) * 2 + STRLEN(";H") + 1]; + + assert(fd >= 0); + + xsprintf(cursor_position, "\x1B[%u;%uH", row, column); + + r = loop_write(fd, cursor_position, SIZE_MAX); + if (r < 0) + return log_warning_errno(r, "Failed to set cursor position, ignoring: %m"); + + return 0; +} -- cgit v1.2.3