Add uu_lock_txfr() to transfer ownership of a successful

uu_lock() to another process.

4 files changed, 62 insertions, 10 deletions

diff --git a/lib/libutil/Makefile b/lib/libutil/Makefile
index aa8ad95..001faf0 100644
--- a/lib/libutil/Makefile
+++ b/lib/libutil/Makefile
@@ -26,7 +26,8 @@ MLINKS+=login_times.3 parse_lt.3 login_times.3 in_ltm.3 \
 	login_times.3 in_lts.3
 MLINKS+=login_ok.3 auth_ttyok.3 login_ok.3 auth_hostok.3 \
 	login_ok.3 auth_timeok.3
-MLINKS+=uucplock.3 uu_lock.3 uucplock.3 uu_unlock.3 uucplock.3 uu_lockerr.3
+MLINKS+=uucplock.3 uu_lock.3 uucplock.3 uu_lock_txfr.3 \
+	uucplock.3 uu_unlock.3 uucplock.3 uu_lockerr.3
 
 beforeinstall:
 	${INSTALL} -C -o ${BINOWN} -g ${BINGRP} -m 444 ${.CURDIR}/libutil.h \
diff --git a/lib/libutil/libutil.h b/lib/libutil/libutil.h
index 8a96284..513acee 100644
--- a/lib/libutil/libutil.h
+++ b/lib/libutil/libutil.h
@@ -18,7 +18,7 @@
  * 5. Modifications may be freely made to this file providing the above
  *    conditions are met.
  *
- * $Id: libutil.h,v 1.12 1997/08/31 20:09:38 brian Exp $
+ * $Id: libutil.h,v 1.13 1997/09/04 22:38:58 pst Exp $
  */
 
 #ifndef _LIBUTIL_H_
@@ -43,6 +43,7 @@ int	forkpty __P((int *_amaster, char *_name,
 		     struct termios *_termp, struct winsize *_winp));
 const char *uu_lockerr __P((int _uu_lockresult));
 int	uu_lock __P((const char *_ttyname));
+int	uu_lock_txfr __P((const char *_ttyname, pid_t _pid));
 int	uu_unlock __P((const char *_ttyname));
 int	_secure_path __P((const char *_path, uid_t _uid, gid_t _gid));
 __END_DECLS
@@ -55,5 +56,6 @@ __END_DECLS
 #define UU_LOCK_WRITE_ERR (-4)
 #define UU_LOCK_LINK_ERR (-5)
 #define UU_LOCK_TRY_ERR (-6)
+#define UU_LOCK_OWNER_ERR (-7)
 
 #endif /* !_LIBUTIL_H_ */
diff --git a/lib/libutil/uucplock.3 b/lib/libutil/uucplock.3
index c920e4a..563323c 100644
--- a/lib/libutil/uucplock.3
+++ b/lib/libutil/uucplock.3
@@ -23,7 +23,7 @@
 .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\" 
-.\" $Id: uucplock.3,v 1.9 1997/09/29 19:11:25 wosch Exp $
+.\" $Id: uucplock.3,v 1.10 1997/10/07 07:24:50 joerg Exp $
 .\" "
 .Dd March 30, 1997
 .Os
@@ -39,6 +39,8 @@
 .Ft int
 .Fn uu_lock "const char *ttyname"
 .Ft int
+.Fn uu_lock_txfr "const char *ttyname" "pid_t pid"
+.Ft int
 .Fn uu_unlock "const char *ttyname"
 .Ft const char *
 .Fn uu_lockerr "int uu_lockresult"
@@ -63,6 +65,11 @@ the process id found in the lock file is no longer running,
 .Fn uu_lock
 will write its own process id into the file and return success.
 .Pp
+.Fn uu_lock_txfr
+transfers lock ownership to another process.
+.Fn uu_lock
+must have previously been successful.
+.Pp
 .Fn uu_unlock
 removes the lockfile created by
 .Fn uu_lock
@@ -130,10 +137,24 @@ to be changed between calls to
 .Fn uu_lock
 and
 .Fn uu_lockerr .
+.Pp
+.Fn uu_lock_txfr
+may return any of the following values:
+.Pp
+.Dv UU_LOCK_OK:
+The transfer was successful.  The specified process now holds the device
+lock.
+.Pp
+.Dv UU_LOCK_OWNER_ERR:
+The current process does not already own a lock on the specified device.
+.Pp
+.Dv UU_LOCK_WRITE_ERR:
+The new process id could not be written to the lock file via a call to
+.Xr write 2 .
 .Sh ERRORS
 If
 .Fn uu_lock
-returns one of the four error values above, the global value
+returns one of the error values above, the global value
 .Va errno
 can be used to determine the cause.  Refer to the respective manual pages
 for further details.
diff --git a/lib/libutil/uucplock.c b/lib/libutil/uucplock.c
index 8e037e4..9f33524 100644
--- a/lib/libutil/uucplock.c
+++ b/lib/libutil/uucplock.c
@@ -30,7 +30,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $Id: uucplock.c,v 1.7 1997/08/05 12:58:02 ache Exp $
+ * $Id: uucplock.c,v 1.8 1997/08/10 18:42:39 ache Exp $
  *
  */
 
@@ -66,7 +66,8 @@ static pid_t get_pid (int fd,int *err);
  * uucp style locking routines
  */
 
-int uu_lock (const char *ttyname)
+int
+uu_lock(const char *ttyname)
 {
 	int fd, tmpfd, i;
 	pid_t pid;
@@ -127,7 +128,28 @@ ret0:
 	return uuerr;
 }
 
-int uu_unlock (const char *ttyname)
+int
+uu_lock_txfr(const char *ttyname, pid_t pid)
+{
+	int fd, err;
+	char lckname[sizeof(_PATH_UUCPLOCK) + MAXNAMLEN];
+
+	snprintf(lckname, sizeof(lckname), _PATH_UUCPLOCK LOCKFMT, ttyname);
+
+	if ((fd = open(lckname, O_RDWR)) < 0)
+		return UU_LOCK_OWNER_ERR;
+	if (get_pid(fd, &err) != getpid())
+		return UU_LOCK_OWNER_ERR;
+        lseek(fd, 0, SEEK_SET);
+	if (put_pid(fd, pid))
+		return UU_LOCK_WRITE_ERR;
+	close(fd);
+
+	return UU_LOCK_OK;
+}
+
+int
+uu_unlock(const char *ttyname)
 {
 	char tbuf[sizeof(_PATH_UUCPLOCK) + MAXNAMLEN];
 
@@ -135,7 +157,8 @@ int uu_unlock (const char *ttyname)
 	return unlink(tbuf);
 }
 
-const char *uu_lockerr (int uu_lockresult)
+const char *
+uu_lockerr(int uu_lockresult)
 {
 	static char errbuf[128];
 	char *fmt;
@@ -163,6 +186,9 @@ const char *uu_lockerr (int uu_lockresult)
 		case UU_LOCK_TRY_ERR:
 			fmt = "too many tries: %s";
 			break;
+		case UU_LOCK_OWNER_ERR:
+			fmt = "not locking process: %s";
+			break;
 		default:
 			fmt = "undefined error: %s";
 			break;
@@ -172,7 +198,8 @@ const char *uu_lockerr (int uu_lockresult)
 	return errbuf;
 }
 
-static int put_pid (int fd, pid_t pid)
+static int
+put_pid(int fd, pid_t pid)
 {
 	char buf[32];
 	int len;
@@ -181,7 +208,8 @@ static int put_pid (int fd, pid_t pid)
 	return write (fd, buf, len) == len;
 }
 
-static pid_t get_pid (int fd, int *err)
+static pid_t
+get_pid(int fd, int *err)
 {
 	int bytes_read;
 	char buf[32];