From b77ac3951932d2ea8bdba2b800380b3e70f8eca2 Mon Sep 17 00:00:00 2001

From: tamz <totemz@protonmail.com>

Date: Thu, 6 Jan 2022 11:56:58 +0100

Subject: agetty: resolve tty name even if stdin is specified

[kzak@redhat.com: - use "const" for options->tty (and friends)

                    as expected by get_terminal_name()]

Addresses: https://github.com/util-linux/util-linux/issues/1546

Signed-off-by: tamz <totemz@protonmail.com>

Signed-off-by: Karel Zak <kzak@redhat.com>

Addresses: https://bugzilla.redhat.com/show_bug.cgi?id=2156946

Upstream: http://github.com/util-linux/util-linux/commit/47831cc02ac0d71c335caecef1753f4c8861277c

---

 term-utils/agetty.c | 26 ++++++++++++++++++--------

 1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/term-utils/agetty.c b/term-utils/agetty.c

index 3b3d5101a..e65cbdeaf 100644

--- a/term-utils/agetty.c

+++ b/term-utils/agetty.c

@@ -186,8 +186,8 @@ struct options {

 	char *chroot;			/* Chroot before the login */

 	char *login;			/* login program */

 	char *logopt;			/* options for login program */

-	char *tty;			/* name of tty */

-	char *vcline;			/* line of virtual console */

+	const char *tty;		/* name of tty */

+	const char *vcline;		/* line of virtual console */

 	char *term;			/* terminal type */

 	char *initstring;		/* modem init string */

 	char *issue;			/* alternative issue file or directory */

@@ -199,6 +199,7 @@ struct options {

 	int numspeed;			/* number of baud rates to try */

 	int clocal;			/* CLOCAL_MODE_* */

 	int kbmode;			/* Keyboard mode if virtual console */

+	int tty_is_stdin;		/* is the tty the standard input stream */

 	speed_t speeds[MAX_SPEED];	/* baud rates to be tried */

 };

@@ -315,7 +316,7 @@ static void init_special_char(char* arg, struct options *op);

 static void parse_args(int argc, char **argv, struct options *op);

 static void parse_speeds(struct options *op, char *arg);

 static void update_utmp(struct options *op);

-static void open_tty(char *tty, struct termios *tp, struct options *op);

+static void open_tty(const char *tty, struct termios *tp, struct options *op);

 static void termio_init(struct options *op, struct termios *tp);

 static void reset_vc(const struct options *op, struct termios *tp, int canon);

 static void auto_baud(struct termios *tp);

@@ -918,6 +919,15 @@ static void parse_args(int argc, char **argv, struct options *op)

 		}

 	}

+	/* resolve the tty path in case it was provided as stdin */

+	if (strcmp(op->tty, "-") == 0) {

+		op->tty_is_stdin = 1;

+		int fd = get_terminal_name(NULL, &op->tty, NULL);

+		if (fd < 0) {

+			log_warn(_("could not get terminal name: %d"), fd);

+		}

+	}

+

 	/* On virtual console remember the line which is used for */

 	if (strncmp(op->tty, "tty", 3) == 0 &&

 	    strspn(op->tty + 3, "0123456789") == strlen(op->tty+3))

@@ -958,8 +968,8 @@ static void update_utmp(struct options *op)

 	time_t t;

 	pid_t pid = getpid();

 	pid_t sid = getsid(0);

-	char *vcline = op->vcline;

-	char *line   = op->tty;

+	const char *vcline = op->vcline;

+	const char *line = op->tty;

 	struct utmpx *utp;

 	/*

@@ -998,7 +1008,7 @@ static void update_utmp(struct options *op)

 			str2memcpy(ut.ut_id, vcline, sizeof(ut.ut_id));

 		else {

 			size_t len = strlen(line);

-			char * ptr;

+			const char * ptr;

 			if (len >= sizeof(ut.ut_id))

 				ptr = line + len - sizeof(ut.ut_id);

 			else

@@ -1026,7 +1036,7 @@ static void update_utmp(struct options *op)

 #endif				/* SYSV_STYLE */

 /* Set up tty as stdin, stdout & stderr. */

-static void open_tty(char *tty, struct termios *tp, struct options *op)

+static void open_tty(const char *tty, struct termios *tp, struct options *op)

 {

 	const pid_t pid = getpid();

 	int closed = 0;

@@ -1036,7 +1046,7 @@ static void open_tty(char *tty, struct termios *tp, struct options *op)

 	/* Set up new standard input, unless we are given an already opened port. */

-	if (strcmp(tty, "-") != 0) {

+	if (!op->tty_is_stdin) {

 		char buf[PATH_MAX+1];

 		struct group *gr = NULL;

 		struct stat st;

-- 

2.39.1