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-rw-r--r--libc/pwd_grp/lckpwdf.c284
1 files changed, 148 insertions, 136 deletions
diff --git a/libc/pwd_grp/lckpwdf.c b/libc/pwd_grp/lckpwdf.c
index 69d2c6718..3509f44bd 100644
--- a/libc/pwd_grp/lckpwdf.c
+++ b/libc/pwd_grp/lckpwdf.c
@@ -1,23 +1,23 @@
/* vi: set sw=4 ts=4: */
/* Handle locking of password file.
- Copyright (C) 1996, 1998 Free Software Foundation, Inc.
+ Copyright (C) 1996,98,2000,02 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.
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 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.
+ Lesser 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. */
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
#include <features.h>
#include <fcntl.h>
@@ -39,6 +39,15 @@ libc_hidden_proto(sigaddset)
libc_hidden_proto(sigemptyset)
libc_hidden_proto(alarm)
+/* 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;
+
+/* Prevent problems in multithreaded program by using mutex. */
#ifdef __UCLIBC_HAS_THREADS__
# include <pthread.h>
static pthread_mutex_t mylock = PTHREAD_MUTEX_INITIALIZER;
@@ -46,145 +55,148 @@ static pthread_mutex_t mylock = PTHREAD_MUTEX_INITIALIZER;
#define LOCK __pthread_mutex_lock(&mylock)
#define UNLOCK __pthread_mutex_unlock(&mylock)
-/* 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 (int __sig);
-int lckpwdf (void)
+int
+__lckpwdf (void)
{
- 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;
-
- lock_fd = open (_PATH_PASSWD, O_WRONLY);
- if (lock_fd == -1) {
- /* Cannot create lock file. */
- UNLOCK;
- 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;
- UNLOCK;
- 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;
- UNLOCK;
- 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;
- UNLOCK;
- 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;
- UNLOCK;
- 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;
- UNLOCK;
- return -1;
- }
-
- UNLOCK;
- return 0;
+ 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;
+
+ /* Prevent problems caused by multiple threads. */
+ LOCK;
+
+ lock_fd = open (_PATH_PASSWD, O_WRONLY);
+ if (lock_fd == -1) {
+ /* Cannot create lock file. */
+ UNLOCK;
+ 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;
+ UNLOCK;
+ 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;
+ UNLOCK;
+ 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;
+ UNLOCK;
+ 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;
+ UNLOCK;
+ 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;
+ UNLOCK;
+ return -1;
+ }
+
+ UNLOCK;
+ return 0;
}
-int ulckpwdf (void)
+int
+__ulckpwdf (void)
{
- int result;
-
- if (lock_fd == -1) {
- /* There is no lock set. */
- result = -1;
- }
- else {
- LOCK;
- result = close (lock_fd);
- /* Mark descriptor as unused. */
- lock_fd = -1;
- UNLOCK;
- }
-
- return result;
+ int result;
+
+ if (lock_fd == -1)
+ /* There is no lock set. */
+ result = -1;
+ else
+ {
+ /* Prevent problems caused by multiple threads. */
+ LOCK;
+
+ result = close (lock_fd);
+
+ /* Mark descriptor as unused. */
+ lock_fd = -1;
+
+ /* Clear mutex. */
+ UNLOCK;
+ }
+
+ return result;
}
-static void noop_handler (attribute_unused int sig)
+static void
+noop_handler (int sig)
{
- /* We simply return which makes the `fcntl' call return with an error. */
+ /* We simply return which makes the `fcntl' call return with an error. */
}