Adding upstream version 3.4.23.upstream/3.4.23upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 173 insertions, 0 deletions

diff --git a/src/global/dot_lockfile.c b/src/global/dot_lockfile.c
new file mode 100644
index 0000000..89a977a
--- /dev/null
+++ b/src/global/dot_lockfile.c
@@ -0,0 +1,173 @@
+/*++
+/* NAME
+/*	dot_lockfile 3
+/* SUMMARY
+/*	dotlock file management
+/* SYNOPSIS
+/*	#include <dot_lockfile.h>
+/*
+/*	int	dot_lockfile(path, why)
+/*	const char *path;
+/*	VSTRING	*why;
+/*
+/*	void	dot_unlockfile(path)
+/*	const char *path;
+/* DESCRIPTION
+/*	dot_lockfile() constructs a lock file name by appending ".lock" to
+/*	\fIpath\fR and creates the named file exclusively. It tries several
+/*	times and attempts to break stale locks. A negative result value
+/*	means no lock file could be created.
+/*
+/*	dot_unlockfile() attempts to remove the lock file created by
+/*	dot_lockfile(). The operation always succeeds, and therefore
+/*	it preserves the errno value.
+/*
+/*	Arguments:
+/* .IP path
+/*	Name of the file to be locked or unlocked.
+/* .IP why
+/*	A null pointer, or storage for the reason why a lock file could
+/*	not be created.
+/* DIAGNOSTICS
+/*	dot_lockfile() returns 0 upon success. In case of failure, the
+/*	result is -1, and the errno variable is set appropriately:
+/*	EEXIST when a "fresh" lock file already exists; other values as
+/*	appropriate.
+/* CONFIGURATION PARAMETERS
+/*	deliver_lock_attempts, how many times to try to create a lock
+/*	deliver_lock_delay, how long to wait between attempts
+/*	stale_lock_time, when to break a stale lock
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/*	Wietse Venema
+/*	IBM T.J. Watson Research
+/*	P.O. Box 704
+/*	Yorktown Heights, NY 10598, USA
+/*--*/
+
+/* System library. */
+
+#include "sys_defs.h"
+#include <sys/stat.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <time.h>
+
+/* Utility library. */
+
+#include <vstring.h>
+#include <stringops.h>
+#include <mymalloc.h>
+#include <iostuff.h>
+#include <warn_stat.h>
+
+/* Global library. */
+
+#include "mail_params.h"
+#include "dot_lockfile.h"
+
+/* Application-specific. */
+
+#define MILLION	1000000
+
+/* dot_lockfile - create user.lock file */
+
+int     dot_lockfile(const char *path, VSTRING *why)
+{
+    char   *lock_file;
+    int     count;
+    struct stat st;
+    int     fd;
+    int     status = -1;
+
+    lock_file = concatenate(path, ".lock", (char *) 0);
+
+    for (count = 1; /* void */ ; count++) {
+
+	/*
+	 * Attempt to create the lock. This code relies on O_EXCL | O_CREAT
+	 * to not follow symlinks. With NFS file systems this operation can
+	 * at the same time succeed and fail with errno of EEXIST.
+	 */
+	if ((fd = open(lock_file, O_WRONLY | O_EXCL | O_CREAT, 0)) >= 0) {
+	    close(fd);
+	    status = 0;
+	    break;
+	}
+	if (count >= var_flock_tries)
+	    break;
+
+	/*
+	 * We can deal only with "file exists" errors. Any other error means
+	 * we better give up trying.
+	 */
+	if (errno != EEXIST)
+	    break;
+
+	/*
+	 * Break the lock when it is too old. Give up when we are unable to
+	 * remove a stale lock.
+	 */
+	if (stat(lock_file, &st) == 0)
+	    if (time((time_t *) 0) > st.st_ctime + var_flock_stale)
+		if (unlink(lock_file) < 0)
+		    if (errno != ENOENT)
+			break;
+
+	rand_sleep(var_flock_delay * MILLION, var_flock_delay * MILLION / 2);
+    }
+    if (status && why)
+	vstring_sprintf(why, "unable to create lock file %s: %m", lock_file);
+
+    myfree(lock_file);
+    return (status);
+}
+
+/* dot_unlockfile - remove .lock file */
+
+void    dot_unlockfile(const char *path)
+{
+    char   *lock_file;
+    int     saved_errno = errno;
+
+    lock_file = concatenate(path, ".lock", (char *) 0);
+    (void) unlink(lock_file);
+    myfree(lock_file);
+    errno = saved_errno;
+}
+
+#ifdef TEST
+
+ /*
+  * Test program for setting a .lock file.
+  * 
+  * Usage: dot_lockfile filename
+  * 
+  * Creates filename.lock and removes it.
+  */
+#include <msg.h>
+#include <vstream.h>
+#include <msg_vstream.h>
+#include <mail_conf.h>
+
+int     main(int argc, char **argv)
+{
+    VSTRING *why = vstring_alloc(100);
+
+    msg_vstream_init(argv[0], VSTREAM_ERR);
+    if (argc != 2)
+	msg_fatal("usage: %s file-to-be-locked", argv[0]);
+    mail_conf_read();
+    if (dot_lockfile(argv[1], why) < 0)
+	msg_fatal("%s", vstring_str(why));
+    dot_unlockfile(argv[1]);
+    vstring_free(why);
+    return (0);
+}
+
+#endif