1 files changed, 103 insertions, 0 deletions
diff --git a/contrib/opie/libopie/unlock.c b/contrib/opie/libopie/unlock.c
new file mode 100644
index 0000000..35c266d
--- /dev/null
+++ b/contrib/opie/libopie/unlock.c
@@ -0,0 +1,103 @@
+/* unlock.c: The opieunlock() library function.
+
+%%% portions-copyright-cmetz
+Portions of this software are Copyright 1996 by Craig Metz, All Rights
+Reserved. The Inner Net License Version 2 applies to these portions of
+the software.
+You should have received a copy of the license with this software. If
+you didn't get a copy, you may request one from <license@inner.net>.
+
+Portions of this software are Copyright 1995 by Randall Atkinson and Dan
+McDonald, All Rights Reserved. All Rights under this copyright are assigned
+to the U.S. Naval Research Laboratory (NRL). The NRL Copyright Notice and
+License Agreement applies to this software.
+
+        History:
+
+	Modified by cmetz for OPIE 2.3. Do refcounts whether or not
+            we actually lock. Fixed USER_LOCKING=0 case.
+	Modified by cmetz for OPIE 2.22. Added reference count support.
+	    Changed lock filename/refcount symbol names to better indicate
+	    that they're not user serviceable.
+	Modified by cmetz for OPIE 2.2. Use FUNCTION declaration.
+            Check for read() == -1. ifdef around unistd.h.
+        Created at NRL for OPIE 2.2 from opiesubr2.c
+*/
+#include "opie_cfg.h"
+#include <string.h>
+#if HAVE_UNISTD_H
+#include <unistd.h>
+#endif /* HAVE_UNISTD_H */
+#include <fcntl.h>
+#include "opie.h"
+
+extern int __opie_lockrefcount;
+#if USER_LOCKING
+extern char *__opie_lockfilename;
+#endif /* USER_LOCKING */
+
+/* 
+  Just remove the lock, right?
+  Well, not exactly -- we need to make sure it's ours. 
+*/
+int opieunlock FUNCTION_NOARGS
+{
+#if USER_LOCKING
+  int fh, rval = -1, pid, t, i;
+  char buffer[128], *c, *c2;
+
+  if (--__opie_lockrefcount > 0)
+    return 0;
+
+  if (!__opie_lockfilename)
+    return -1;
+
+  if (!(fh = open(__opie_lockfilename, O_RDWR, 0600)))
+    goto unlockret;
+
+  if ((i = read(fh, buffer, sizeof(buffer))) < 0)
+    goto unlockret;
+
+  buffer[sizeof(buffer) - 1] = 0;
+  buffer[i - 1] = 0;
+
+  if (!(c = strchr(buffer, '\n')))
+    goto unlockret;
+
+  *(c++) = 0;
+
+  if (!(c2 = strchr(c, '\n')))
+    goto unlockret;
+
+  *(c2++) = 0;
+
+  if (!(pid = atoi(buffer)))
+    goto unlockret;
+
+  if (!(t = atoi(c)))
+    goto unlockret;
+
+  if ((pid != getpid()) && (time(NULL) + OPIE_LOCK_TIMEOUT <= t) && 
+    (!kill(pid, 0))) { 
+    rval = 1;
+    goto unlockret1;
+  }
+
+  rval = 0;
+
+unlockret:
+  unlink(__opie_lockfilename);
+
+unlockret1:
+  if (fh)
+    close(fh);
+  free(__opie_lockfilename);
+  __opie_lockfilename = NULL;
+  return rval;
+#else /* USER_LOCKING */
+  if (__opie_lockrefcount-- > 0)
+    return 0;
+
+  return -1;
+#endif /* USER_LOCKING */
+}