-finish:
- /* Just in case, flush all crap out */
- tcflush(fd, TCIOFLUSH);
-
- return r;
-}
-
-int reset_terminal(const char *name) {
- _cleanup_close_ int fd = -1;
-
- fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
- if (fd < 0)
- return fd;
-
- return reset_terminal_fd(fd, true);
-}
-
-int open_terminal(const char *name, int mode) {
- int fd, r;
- 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
- */
-
- assert(!(mode & O_CREAT));
-
- for (;;) {
- fd = open(name, mode, 0);
- if (fd >= 0)
- break;
-
- if (errno != EIO)
- return -errno;
-
- /* Max 1s in total */
- if (c >= 20)
- return -errno;
-
- usleep(50 * USEC_PER_MSEC);
- c++;
- }
-
- r = isatty(fd);
- if (r < 0) {
- safe_close(fd);
- return -errno;
- }
-
- if (!r) {
- safe_close(fd);
- return -ENOTTY;
- }
-
- return fd;
-}
-
-int flush_fd(int fd) {
- struct pollfd pollfd = {
- .fd = fd,
- .events = POLLIN,
- };
-
- for (;;) {
- char buf[LINE_MAX];
- ssize_t l;
- int r;
-
- r = poll(&pollfd, 1, 0);
- if (r < 0) {
- if (errno == EINTR)
- continue;
-
- return -errno;
-
- } else if (r == 0)
- return 0;
-
- l = read(fd, buf, sizeof(buf));
- if (l < 0) {
-
- if (errno == EINTR)
- continue;
-
- if (errno == EAGAIN)
- return 0;
-
- return -errno;
- } else if (l == 0)
- return 0;
- }
-}
-
-int acquire_terminal(
- const char *name,
- bool fail,
- bool force,
- bool ignore_tiocstty_eperm,
- usec_t timeout) {
-
- int fd = -1, notify = -1, r = 0, wd = -1;
- usec_t ts = 0;
-
- assert(name);
-
- /* 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 not configure any service
- * on the same tty as an untrusted user this should not be a
- * problem. (Which he probably should not do anyway.) */
-
- if (timeout != USEC_INFINITY)
- ts = now(CLOCK_MONOTONIC);
-
- if (!fail && !force) {
- notify = inotify_init1(IN_CLOEXEC | (timeout != USEC_INFINITY ? IN_NONBLOCK : 0));
- if (notify < 0) {
- r = -errno;
- goto fail;
- }
-
- wd = inotify_add_watch(notify, name, IN_CLOSE);
- if (wd < 0) {
- r = -errno;
- goto fail;
- }
- }
-
- 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)
- goto fail;
- }
-
- /* 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 */
- if (ioctl(fd, TIOCSCTTY, force) < 0)
- r = -errno;
-
- assert_se(sigaction(SIGHUP, &sa_old, NULL) == 0);
-
- /* Sometimes it makes sense to ignore TIOCSCTTY
- * returning EPERM, i.e. when very likely we already
- * are have this controlling terminal. */
- if (r < 0 && r == -EPERM && ignore_tiocstty_eperm)
- r = 0;
-
- if (r < 0 && (force || fail || r != -EPERM)) {
- goto fail;
- }
-
- if (r >= 0)
- break;
-
- assert(!fail);
- assert(!force);
- assert(notify >= 0);
-
- for (;;) {
- union inotify_event_buffer buffer;
- struct inotify_event *e;
- ssize_t l;
-
- if (timeout != USEC_INFINITY) {
- usec_t n;
-
- n = now(CLOCK_MONOTONIC);
- if (ts + timeout < n) {
- r = -ETIMEDOUT;
- goto fail;
- }
-
- r = fd_wait_for_event(fd, POLLIN, ts + timeout - n);
- if (r < 0)
- goto fail;
-
- if (r == 0) {
- r = -ETIMEDOUT;
- goto fail;
- }
- }
-
- l = read(notify, &buffer, sizeof(buffer));
- if (l < 0) {
- if (errno == EINTR || errno == EAGAIN)
- continue;
-
- r = -errno;
- goto fail;
- }
-
- FOREACH_INOTIFY_EVENT(e, buffer, l) {
- if (e->wd != wd || !(e->mask & IN_CLOSE)) {
- r = -EIO;
- goto fail;
- }
- }
-
- 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);
- }
-
- safe_close(notify);
-
- r = reset_terminal_fd(fd, true);
- if (r < 0)
- log_warning_errno(r, "Failed to reset terminal: %m");
-
- return fd;
-
-fail:
- safe_close(fd);
- safe_close(notify);
-
- return r;
-}
-
-int release_terminal(void) {
- static const struct sigaction sa_new = {
- .sa_handler = SIG_IGN,
- .sa_flags = SA_RESTART,
- };
-
- _cleanup_close_ int fd = -1;
- struct sigaction sa_old;
- int r = 0;
-
- fd = open("/dev/tty", O_RDWR|O_NOCTTY|O_NDELAY|O_CLOEXEC);
- 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);
-
- if (ioctl(fd, TIOCNOTTY) < 0)
- r = -errno;
-
- assert_se(sigaction(SIGHUP, &sa_old, NULL) == 0);
-
- return r;
-}
-
-int sigaction_many(const struct sigaction *sa, ...) {
- va_list ap;
- int r = 0, sig;
-
- va_start(ap, sa);
- while ((sig = va_arg(ap, int)) > 0)
- if (sigaction(sig, sa, NULL) < 0)
- r = -errno;
- va_end(ap);
-
- return r;
-}
-
-int ignore_signals(int sig, ...) {
- struct sigaction sa = {
- .sa_handler = SIG_IGN,
- .sa_flags = SA_RESTART,
- };
- va_list ap;
- int r = 0;
-
- if (sigaction(sig, &sa, NULL) < 0)
- r = -errno;
-
- va_start(ap, sig);
- while ((sig = va_arg(ap, int)) > 0)
- if (sigaction(sig, &sa, NULL) < 0)
- r = -errno;
- va_end(ap);
-
- return r;
-}
-
-int default_signals(int sig, ...) {
- struct sigaction sa = {
- .sa_handler = SIG_DFL,
- .sa_flags = SA_RESTART,
- };
- va_list ap;
- int r = 0;
-
- if (sigaction(sig, &sa, NULL) < 0)
- r = -errno;
-
- va_start(ap, sig);
- while ((sig = va_arg(ap, int)) > 0)
- if (sigaction(sig, &sa, NULL) < 0)
- r = -errno;
- va_end(ap);
-
- return r;
-}
-
-void safe_close_pair(int p[]) {
- assert(p);
-
- if (p[0] == p[1]) {
- /* Special case pairs which use the same fd in both
- * directions... */
- p[0] = p[1] = safe_close(p[0]);
- return;
- }
-
- p[0] = safe_close(p[0]);
- p[1] = safe_close(p[1]);
-}
-
-ssize_t loop_read(int fd, void *buf, size_t nbytes, bool do_poll) {
- uint8_t *p = buf;
- ssize_t n = 0;
-
- assert(fd >= 0);
- assert(buf);
-
- while (nbytes > 0) {
- ssize_t k;
-
- k = read(fd, p, nbytes);
- if (k < 0) {
- if (errno == EINTR)
- continue;
-
- if (errno == EAGAIN && do_poll) {
-
- /* We knowingly ignore any return value here,
- * and expect that any error/EOF is reported
- * via read() */
-
- fd_wait_for_event(fd, POLLIN, USEC_INFINITY);
- continue;
- }
-
- return n > 0 ? n : -errno;
- }
-
- if (k == 0)
- return n;
-
- p += k;
- nbytes -= k;
- n += k;
- }
-
- return n;
-}
-
-int loop_read_exact(int fd, void *buf, size_t nbytes, bool do_poll) {
- ssize_t n;
-
- n = loop_read(fd, buf, nbytes, do_poll);
- if (n < 0)
- return n;
- if ((size_t) n != nbytes)
- return -EIO;
- return 0;
-}
-
-int loop_write(int fd, const void *buf, size_t nbytes, bool do_poll) {
- const uint8_t *p = buf;
-
- assert(fd >= 0);
- assert(buf);
-
- errno = 0;
-
- while (nbytes > 0) {
- ssize_t k;
-
- k = write(fd, p, nbytes);
- if (k < 0) {
- if (errno == EINTR)
- continue;
-
- if (errno == EAGAIN && do_poll) {
- /* We knowingly ignore any return value here,
- * and expect that any error/EOF is reported
- * via write() */
-
- fd_wait_for_event(fd, POLLOUT, USEC_INFINITY);
- continue;
- }
-
- return -errno;
- }
-
- if (k == 0) /* Can't really happen */
- return -EIO;
-
- p += k;
- nbytes -= k;
- }
-
- return 0;
-}
-
-int parse_size(const char *t, off_t base, off_t *size) {
-
- /* Soo, sometimes we want to parse IEC binary suffxies, and
- * sometimes SI decimal suffixes. This function can parse
- * both. Which one is the right way depends on the
- * context. Wikipedia suggests that SI is customary for
- * hardrware metrics and network speeds, while IEC is
- * customary for most data sizes used by software and volatile
- * (RAM) memory. Hence be careful which one you pick!
- *
- * In either case we use just K, M, G as suffix, and not Ki,
- * Mi, Gi or so (as IEC would suggest). That's because that's
- * frickin' ugly. But this means you really need to make sure
- * to document which base you are parsing when you use this
- * call. */
-
- struct table {
- const char *suffix;
- unsigned long long factor;
- };