1 files changed, 95 insertions, 0 deletions
diff --git a/src/openvpn/occ.h b/src/openvpn/occ.h
new file mode 100644
index 0000000..5d88cc9
--- /dev/null
+++ b/src/openvpn/occ.h
@@ -0,0 +1,95 @@
+/*
+ *  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) 2002-2010 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
+ */
+
+#ifndef OCC_H
+#define OCC_H
+
+#ifdef ENABLE_OCC
+
+#include "forward.h"
+
+/* OCC_STRING_SIZE must be set to sizeof (occ_magic) */
+#define OCC_STRING_SIZE 16
+
+/*
+ * OCC (OpenVPN Configuration Control) protocol opcodes.
+ */
+
+#define OCC_REQUEST   0		/* request options string from peer */
+#define OCC_REPLY     1		/* deliver options string to peer */
+
+/*
+ * Send an OCC_REQUEST once every OCC_INTERVAL
+ * seconds until a reply is received.
+ *
+ * If we haven't received a reply after
+ * OCC_N_TRIES, give up.
+ */
+#define OCC_INTERVAL_SECONDS 10
+#define OCC_N_TRIES          12
+
+/*
+ * Other OCC protocol opcodes used to estimate the MTU empirically.
+ */
+#define OCC_MTU_LOAD_REQUEST   2	/* Ask peer to send a big packet to us */
+#define OCC_MTU_LOAD           3	/* Send a big packet to peer */
+#define OCC_MTU_REQUEST        4	/* Ask peer to tell us the largest
+					   packet it has received from us so far */
+#define OCC_MTU_REPLY          5	/* Send largest packet size to peer */
+
+/*
+ * Process one command from mtu_load_test_sequence
+ * once every n seconds, if --mtu-test is specified.
+ */
+#define OCC_MTU_LOAD_INTERVAL_SECONDS 3
+
+/*
+ * Send an exit message to remote.
+ */
+#define OCC_EXIT               6
+
+/*
+ * Used to conduct a load test command sequence
+ * of UDP connection for empirical MTU measurement.
+ */
+struct mtu_load_test
+{
+  int op;			/* OCC opcode to send to peer */
+  int delta;			/* determine packet size to send by using
+				   this delta against currently
+				   configured MTU */
+};
+
+extern const uint8_t occ_magic[];
+
+static inline bool
+is_occ_msg (const struct buffer* buf)
+{
+  return buf_string_match_head (buf, occ_magic, OCC_STRING_SIZE);
+}
+
+void process_received_occ_msg (struct context *c);
+
+#endif
+#endif