sync code with last improvements from OpenBSD

app/xsm/lock.c

@@ -0,0 +1,165 @@
+/* $Xorg: lock.c,v 1.4 2001/02/09 02:05:59 xorgcvs Exp $ */
+/******************************************************************************
+
+Copyright 1994, 1998  The Open Group
+
+Permission to use, copy, modify, distribute, and sell this software and its
+documentation for any purpose is hereby granted without fee, provided that
+the above copyright notice appear in all copies and that both that
+copyright notice and this permission notice appear in supporting
+documentation.
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+Except as contained in this notice, the name of The Open Group shall not be
+used in advertising or otherwise to promote the sale, use or other dealings
+in this Software without prior written authorization from The Open Group.
+******************************************************************************/
+/* $XFree86: xc/programs/xsm/lock.c,v 3.4 2001/12/14 20:02:25 dawes Exp $ */
+
+#include "xsm.h"
+#include "lock.h"
+#include "choose.h"
+#include <sys/types.h>
+
+
+static const char *
+GetPath(void)
+{
+    const char *path = getenv ("SM_SAVE_DIR");
+
+    if (!path)
+    {
+	path = getenv ("HOME");
+	if (!path)
+	    path = ".";
+    }
+
+    return (path);
+}
+
+
+Status
+LockSession(const char *session_name, Bool write_id)
+{
+    const char *path;
+    char lock_file[PATH_MAX];
+    char temp_lock_file[PATH_MAX];
+    Status status;
+    int fd;
+
+    path = GetPath ();
+
+    snprintf (lock_file, sizeof(lock_file), "%s/.XSMlock-%s",
+	      path, session_name);
+    snprintf (temp_lock_file, sizeof(temp_lock_file), "%s/.XSMtlock-%s",
+	      path, session_name);
+
+    if ((fd = creat (temp_lock_file, 0444)) < 0)
+	return (0);
+
+    if ((write_id &&
+        (write (fd, networkIds, strlen (networkIds)) != strlen (networkIds))) ||
+	(write (fd, "\n", 1) != 1))
+    {
+	close (fd);
+	return (0);
+    }
+
+    close (fd);
+
+    status = 1;
+
+    if (link (temp_lock_file, lock_file) < 0)
+	status = 0;
+
+    if (remove (temp_lock_file) < 0)
+	status = 0;
+
+    return (status);
+}
+
+
+void
+UnlockSession(const char *session_name)
+{
+    const char *path;
+    char lock_file[PATH_MAX];
+
+    path = GetPath ();
+
+    snprintf (lock_file, sizeof(lock_file), "%s/.XSMlock-%s",
+	      path, session_name);
+
+    remove (lock_file);
+}
+
+
+char *
+GetLockId(const char *session_name)
+{
+    const char *path;
+    FILE *fp;
+    char lock_file[PATH_MAX];
+    char buf[256];
+    char *ret;
+
+    path = GetPath ();
+
+    snprintf (lock_file, sizeof(lock_file), "%s/.XSMlock-%s",
+	      path, session_name);
+
+    if ((fp = fopen (lock_file, "r")) == NULL)
+    {
+	return (NULL);
+    }
+    fcntl(fileno(fp), F_SETFD, FD_CLOEXEC);
+
+    buf[0] = '\0';
+    fscanf (fp, "%255s\n", buf);
+    ret = XtNewString (buf);
+
+    fclose (fp);
+
+    return (ret);
+}
+
+
+Bool
+CheckSessionLocked(const char *session_name, Bool get_id, char **id_ret)
+{
+    if (get_id)
+	*id_ret = GetLockId (session_name);
+
+    if (!LockSession (session_name, False))
+	return (1);
+
+    UnlockSession (session_name);
+    return (0);
+}
+
+
+void
+UnableToLockSession(const char *session_name)
+{
+    /*
+     * We should popup a dialog here giving error.
+     */
+
+#ifdef XKB
+    XkbStdBell(XtDisplay(topLevel),XtWindow(topLevel),0,XkbBI_Failure);
+#else
+    XBell (XtDisplay (topLevel), 0);
+#endif
+    sleep (2);
+
+    ChooseSession ();
+}