* Added /etc/shadow support (Config selectable)

* Moved some file paths from code into <paths.h>

1 files changed, 163 insertions, 0 deletions

diff --git a/libc/pwd_grp/lckpwdf.c b/libc/pwd_grp/lckpwdf.c
new file mode 100644
index 000000000..2f55ff65a
--- /dev/null
+++ b/libc/pwd_grp/lckpwdf.c
@@ -0,0 +1,163 @@
+/* Handle locking of password file.
+   Copyright (C) 1996, 1998 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <fcntl.h>
+#include <shadow.h>
+#include <signal.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/file.h>
+#include <paths.h>
+
+/* How long to wait for getting the lock before returning with an
+   error.  */
+#define TIMEOUT 15 /* sec */
+
+/* File descriptor for lock file.  */
+static int lock_fd = -1;
+
+/* Prototypes for local functions.  */
+static void noop_handler __P ((int __sig));
+
+
+int
+lckpwdf ()
+{
+	int flags;
+	sigset_t saved_set;         /* Saved set of caught signals.  */
+	struct sigaction saved_act; /* Saved signal action.  */
+	sigset_t new_set;           /* New set of caught signals.  */
+	struct sigaction new_act;   /* New signal action.  */
+	struct flock fl;            /* Information struct for locking.  */
+	int result;
+
+	if (lock_fd != -1)
+		/* Still locked by own process.  */
+		return -1;
+
+	lock_fd = open (_PATH_PASSWD, O_WRONLY);
+	if (lock_fd == -1)
+		/* Cannot create lock file.  */
+		return -1;
+
+	/* Make sure file gets correctly closed when process finished.  */
+	flags = fcntl (lock_fd, F_GETFD, 0);
+	if (flags == -1) {
+		/* Cannot get file flags.  */
+		close(lock_fd);
+		lock_fd = -1;
+		return -1;
+	}
+	flags |= FD_CLOEXEC;		/* Close on exit.  */
+	if (fcntl (lock_fd, F_SETFD, flags) < 0) {
+		/* Cannot set new flags.  */
+		close(lock_fd);
+		lock_fd = -1;
+		return -1;
+	}
+
+	/* Now we have to get exclusive write access.  Since multiple
+	   process could try this we won't stop when it first fails.
+	   Instead we set a timeout for the system call.  Once the timer
+	   expires it is likely that there are some problems which cannot be
+	   resolved by waiting.
+	   
+	   It is important that we don't change the signal state.  We must
+	   restore the old signal behaviour.  */
+	memset (&new_act, '\0', sizeof (struct sigaction));
+	new_act.sa_handler = noop_handler;
+	sigfillset (&new_act.sa_mask);
+	new_act.sa_flags = 0ul;
+
+	/* Install new action handler for alarm and save old.  */
+	if (sigaction (SIGALRM, &new_act, &saved_act) < 0) {
+		/* Cannot install signal handler.  */
+		close(lock_fd);
+		lock_fd = -1;
+		return -1;
+	}
+
+	/* Now make sure the alarm signal is not blocked.  */
+	sigemptyset (&new_set);
+	sigaddset (&new_set, SIGALRM);
+	if (sigprocmask (SIG_UNBLOCK, &new_set, &saved_set) < 0) {
+		sigaction (SIGALRM, &saved_act, NULL);
+		close(lock_fd);
+		lock_fd = -1;
+		return -1;
+	}
+
+	/* Start timer.  If we cannot get the lock in the specified time we
+	   get a signal.  */
+	alarm (TIMEOUT);
+
+	/* Try to get the lock.  */
+	memset (&fl, '\0', sizeof (struct flock));
+	fl.l_type = F_WRLCK;
+	fl.l_whence = SEEK_SET;
+	result = fcntl (lock_fd, F_SETLKW, &fl);
+
+	/* Clear alarm.  */
+	alarm (0);
+
+	/* Restore old set of handled signals.  We don't need to know
+	   about the current one.*/
+	sigprocmask (SIG_SETMASK, &saved_set, NULL);
+
+	/* Restore old action handler for alarm.  We don't need to know
+	   about the current one.  */
+	sigaction (SIGALRM, &saved_act, NULL);
+
+	if (result < 0) {
+		close(lock_fd);
+		lock_fd = -1;
+		return -1;
+	}
+
+	return 0;
+}
+
+
+int
+ulckpwdf ()
+{
+	int result;
+	
+	if (lock_fd == -1) {
+		/* There is no lock set.  */
+		result = -1;
+	}
+	else {
+		result = close (lock_fd);
+		
+		/* Mark descriptor as unused.  */
+		lock_fd = -1;
+	}
+
+	return result;
+}
+
+
+static void
+noop_handler (sig)
+	int sig;
+{
+	/* We simply return which makes the `fcntl' call return with an error.  */
+}