1 files changed, 122 insertions, 0 deletions
diff --git a/src/openvpn/mstats.c b/src/openvpn/mstats.c
new file mode 100644
index 0000000..3be493c
--- /dev/null
+++ b/src/openvpn/mstats.c
@@ -0,0 +1,122 @@
+/*
+ *  OpenVPN -- An application to securely tunnel IP networks
+ *             over a single TCP/UDP port, with support for SSL/TLS-based
+ *             session authentication and key exchange,
+ *             packet encryption, packet authentication, and
+ *             packet compression.
+ *
+ *  Copyright (C) 2002-2011 OpenVPN Technologies, Inc. <sales@openvpn.net>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  as published by the Free Software Foundation.
+ *
+ *  This program 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program (see the file COPYING included with this
+ *  distribution); if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+/*
+ * Maintain usage stats in a memory-mapped file
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#elif defined(_MSC_VER)
+#include "config-msvc.h"
+#endif
+
+#include "syshead.h"
+
+#if defined(ENABLE_MEMSTATS)
+
+#include <sys/mman.h>
+
+#include "error.h"
+#include "misc.h"
+#include "mstats.h"
+
+#include "memdbg.h"
+
+volatile struct mmap_stats *mmap_stats = NULL; /* GLOBAL */
+static char mmap_fn[128];
+
+void
+mstats_open(const char *fn)
+{
+  void *data;
+  ssize_t stat;
+  int fd;
+  struct mmap_stats ms;
+
+  if (mmap_stats) /* already called? */
+    return;
+
+  /* verify that filename is not too long */
+  if (strlen(fn) >= sizeof(mmap_fn))
+    msg (M_FATAL, "mstats_open: filename too long");
+
+  /* create file that will be memory mapped */
+  fd = open (fn, O_CREAT | O_TRUNC | O_RDWR, S_IRUSR | S_IWUSR);
+  if (fd < 0)
+    {
+      msg (M_ERR, "mstats_open: cannot open: %s", fn);
+      return;
+    }
+
+  /* set the file to the correct size to contain a
+     struct mmap_stats, and zero it */
+  CLEAR(ms);
+  ms.state = MSTATS_ACTIVE;
+  stat = write(fd, &ms, sizeof(ms));
+  if (stat != sizeof(ms))
+    {
+      msg (M_ERR, "mstats_open: write error: %s", fn);
+      close(fd);
+      return;
+    }
+
+  /* mmap the file */
+  data = mmap(NULL, sizeof(struct mmap_stats), PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
+  if (data == MAP_FAILED)
+    {
+      msg (M_ERR, "mstats_open: write error: %s", fn);
+      close(fd);
+      return;
+    }
+
+  /* close the fd (mmap now controls the file) */
+  if (close(fd))
+    {
+      msg (M_ERR, "mstats_open: close error: %s", fn);
+    }
+
+  /* save filename so we can delete it later */
+  strcpy(mmap_fn, fn);
+
+  /* save a global pointer to memory-mapped region */
+  mmap_stats = (struct mmap_stats *)data;
+
+  msg (M_INFO, "memstats data will be written to %s", fn);
+}
+
+void
+mstats_close(void)
+{
+  if (mmap_stats)
+    {
+      mmap_stats->state = MSTATS_EXPIRED;
+      if (munmap((void *)mmap_stats, sizeof(struct mmap_stats)))
+	msg (M_WARN | M_ERRNO, "mstats_close: munmap error");
+      platform_unlink(mmap_fn);
+      mmap_stats = NULL;
+    }
+}
+
+#endif