agetty: close tty before vhangup()

Let's close all tty file descriptors if called with --hangup option.

References: https://lkml.org/lkml/2012/6/5/145
Signed-off-by: Karel Zak <kzak@redhat.com>

1 files changed, 27 insertions, 17 deletions

diff --git a/term-utils/agetty.c b/term-utils/agetty.c
index b2cc24cca..fab83b8ff 100644
--- a/term-utils/agetty.c
+++ b/term-utils/agetty.c
@@ -264,7 +264,7 @@ static void login_options_to_argv(char *argv[], int *argc, char *str, char *user
 static char *fakehost;
 
 #ifdef DEBUGGING
-#define debug(s) do { fprintf(dbf,s); fflush(dbf); while (0)
+#define debug(s) do { fprintf(dbf,s); fflush(dbf); } while (0)
 FILE *dbf;
 #else
 #define debug(s) do { ; } while (0)
@@ -869,10 +869,12 @@ static void update_utmp(struct options *op)
 static void open_tty(char *tty, struct termios *tp, struct options *op)
 {
 	const pid_t pid = getpid();
-	int serial;
+	int serial, closed = 0;
 
 	/* Set up new standard input, unless we are given an already opened port. */
 
+sleep(10);
+
 	if (strcmp(tty, "-") != 0) {
 		char buf[PATH_MAX+1];
 		struct group *gr = NULL;
@@ -919,27 +921,33 @@ static void open_tty(char *tty, struct termios *tp, struct options *op)
 				log_warn("/dev/%s: cannot get controlling tty: %m", tty);
 		}
 
+		close(STDIN_FILENO);
+		errno = 0;
+
 		if (op->flags & F_HANGUP) {
+
+			if (ioctl(fd, TIOCNOTTY))
+				debug("TIOCNOTTY ioctl failed\n");
+
 			/*
-			 * vhangup() will replace all open file descriptors in the kernel
-			 * that point to our controlling tty by a dummy that will deny
-			 * further reading/writing to our device. It will also reset the
-			 * tty to sane defaults, so we don't have to modify the tty device
-			 * for sane settings. We also get a SIGHUP/SIGCONT.
+			 * Let's close all file decriptors before vhangup
+			 * https://lkml.org/lkml/2012/6/5/145
 			 */
+			close(fd);
+			close(STDOUT_FILENO);
+			close(STDERR_FILENO);
+			errno = 0;
+			closed = 1;
+
 			if (vhangup())
 				log_err("/dev/%s: vhangup() failed: %m", tty);
-			if (ioctl(fd, TIOCNOTTY))
-				debug("TIOCNOTTY ioctl failed\n");
-		}
-
-		close(fd);
-		close(STDIN_FILENO);
-		errno = 0;
+		} else
+			close(fd);
 
 		debug("open(2)\n");
 		if (open(buf, O_RDWR|O_NOCTTY|O_NONBLOCK, 0) != 0)
 			log_err(_("/dev/%s: cannot open as standard input: %m"), tty);
+
 		if (((tid = tcgetsid(STDIN_FILENO)) < 0) || (pid != tid)) {
 			if (ioctl(STDIN_FILENO, TIOCSCTTY, 1) == -1)
 				log_warn("/dev/%s: cannot get controlling tty: %m", tty);
@@ -961,9 +969,11 @@ static void open_tty(char *tty, struct termios *tp, struct options *op)
 		log_warn("/dev/%s: cannot set process group: %m", tty);
 
 	/* Get rid of the present outputs. */
-	close(STDOUT_FILENO);
-	close(STDERR_FILENO);
-	errno = 0;
+	if (!closed) {
+		close(STDOUT_FILENO);
+		close(STDERR_FILENO);
+		errno = 0;
+	}
 
 	/* Set up standard output and standard error file descriptors. */
 	debug("duping\n");