diff options
| -rw-r--r-- | src/getty-generator/getty-generator.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/src/getty-generator/getty-generator.c b/src/getty-generator/getty-generator.c index f352a29f99..08b3b1e7df 100644 --- a/src/getty-generator/getty-generator.c +++ b/src/getty-generator/getty-generator.c @@ -22,6 +22,7 @@ #include <string.h> #include <errno.h> #include <unistd.h> +#include <fcntl.h> #include "log.h" #include "util.h" @@ -92,6 +93,30 @@ static int add_container_getty(const char *tty) { return add_symlink("container-getty@.service", n); } +static int verify_tty(const char *name) { + _cleanup_close_ int fd = -1; + const char *p; + + /* Some TTYs are weird and have been enumerated but don't work + * when you try to use them, such as classic ttyS0 and + * friends. Let's check that and open the device and run + * isatty() on it. */ + + p = strappenda("/dev/", name); + + /* O_NONBLOCK is essential here, to make sure we don't wait + * for DCD */ + fd = open(p, O_RDWR|O_NONBLOCK|O_NOCTTY|O_CLOEXEC|O_NOFOLLOW); + if (fd < 0) + return -errno; + + errno = 0; + if (isatty(fd) <= 0) + return errno ? -errno : -EIO; + + return 0; +} + int main(int argc, char *argv[]) { static const char virtualization_consoles[] = @@ -180,6 +205,9 @@ int main(int argc, char *argv[]) { if (isempty(tty) || tty_is_vc(tty)) continue; + if (verify_tty(tty) < 0) + continue; + /* We assume that gettys on virtual terminals are * started via manual configuration and do this magic * only for non-VC terminals. */ |