This is the start of the BETA21 branch.

It includes the --topology feature, and
TAP-Win32 driver changes to allow
non-admin access.



git-svn-id: http://svn.openvpn.net/projects/openvpn/branches/BETA21/openvpn@580 e7ae566f-a301-0410-adde-c780ea21d3b5

1 files changed, 188 insertions, 0 deletions

diff --git a/fragment.h b/fragment.h
new file mode 100644
index 0000000..f5b8948
--- /dev/null
+++ b/fragment.h
@@ -0,0 +1,188 @@
+/*
+ *  OpenVPN -- An application to securely tunnel IP networks
+ *             over a single UDP port, with support for SSL/TLS-based
+ *             session authentication and key exchange,
+ *             packet encryption, packet authentication, and
+ *             packet compression.
+ *
+ *  Copyright (C) 2002-2005 OpenVPN Solutions LLC <info@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 FRAGMENT_H
+#define FRAGMENT_H
+
+#ifdef ENABLE_FRAGMENT
+
+#include "common.h"
+#include "buffer.h"
+#include "interval.h"
+#include "mtu.h"
+#include "shaper.h"
+#include "error.h"
+
+#define N_FRAG_BUF                   25      /* number of packet buffers */
+#define FRAG_TTL_SEC                 10      /* number of seconds time-to-live for a fragment */
+#define FRAG_WAKEUP_INTERVAL         5       /* wakeup code called once per n seconds */
+
+struct fragment {
+  bool defined;
+
+  int max_frag_size;               /* maximum size of each fragment */
+
+  /*
+   * 32 bit array corresponding to each fragment.  A 1 bit in element n means that
+   * the fragment n has been received.  Needs to have at least MAX_FRAGS bits.
+   */
+# define FRAG_MAP_MASK 0xFFFFFFFF
+# define MAX_FRAGS             32  /* maximum number of fragments per packet */
+  unsigned int map;
+
+  time_t timestamp;                /* timestamp for time-to-live purposes */
+
+  struct buffer buf;               /* fragment assembly buffer for received datagrams */
+};
+
+struct fragment_list {
+  int seq_id;
+  int index;
+  struct fragment fragments[N_FRAG_BUF];
+};
+
+struct fragment_master {
+  struct event_timeout wakeup;     /* when should main openvpn event loop wake us up */
+
+  /* true if the OS has explicitly recommended an MTU value */
+  bool received_os_mtu_hint;
+
+  /* a sequence ID describes a set of fragments that make up one datagram */
+# define N_SEQ_ID            256   /* sequence number wraps to 0 at this value (should be a power of 2) */
+  int outgoing_seq_id;             /* sent as FRAG_SEQ_ID below */
+
+  /* outgoing packet is possibly sent as a series of fragments */
+
+# define MAX_FRAG_PKT_SIZE 65536   /* maximum packet size */
+  int outgoing_frag_size;          /* sent to peer via FRAG_SIZE when FRAG_YES_LAST set */
+
+  int outgoing_frag_id;            /* each fragment in a datagram is numbered 0 to MAX_FRAGS-1 */ 
+
+  struct buffer outgoing;          /* outgoing datagram, free if current_frag_id == 0 */
+  struct buffer outgoing_return;   /* buffer to return outgoing fragment */
+
+  /* incoming fragments from remote */
+  struct fragment_list incoming;
+};
+
+/*
+ * Fragment header sent over the wire.
+ */
+
+typedef uint32_t fragment_header_type;
+
+/* convert a fragment_header_type from host to network order */
+#define hton_fragment_header_type(x) htonl(x)
+
+/* convert a fragment_header_type from network to host order */
+#define ntoh_fragment_header_type(x) ntohl(x)
+
+/* FRAG_TYPE 2 bits */
+#define FRAG_TYPE_MASK        0x00000003
+#define FRAG_TYPE_SHIFT       0
+
+#define FRAG_WHOLE            0    /* packet is whole, FRAG_N_PACKETS_RECEIVED echoed back to peer */
+#define FRAG_YES_NOTLAST      1    /* packet is a fragment, but is not the last fragment,
+				      FRAG_N_PACKETS_RECEIVED set as above */
+#define FRAG_YES_LAST         2    /* packet is the last fragment, FRAG_SIZE = size of non-last frags */
+#define FRAG_TEST             3    /* control packet for establishing MTU size (not implemented yet) */
+
+/* FRAG_SEQ_ID 8 bits */
+#define FRAG_SEQ_ID_MASK      0x000000ff
+#define FRAG_SEQ_ID_SHIFT     2
+
+/* FRAG_ID 5 bits */
+#define FRAG_ID_MASK          0x0000001f
+#define FRAG_ID_SHIFT         10
+
+/*
+ * FRAG_SIZE  14 bits
+ *
+ * IF FRAG_YES_LAST (FRAG_SIZE):
+ *   The max size of a fragment.  If a fragment is not the last fragment in the packet,
+ *   then the fragment size is guaranteed to be equal to the max fragment size.  Therefore,
+ *   max_frag_size is only sent over the wire if FRAG_LAST is set.  Otherwise it is assumed
+ *   to be the actual fragment size received.
+ */
+
+/* FRAG_SIZE 14 bits */
+#define FRAG_SIZE_MASK        0x00003fff
+#define FRAG_SIZE_SHIFT       15
+#define FRAG_SIZE_ROUND_SHIFT 2  /* fragment/datagram sizes represented as multiple of 4 */
+
+#define FRAG_SIZE_ROUND_MASK ((1 << FRAG_SIZE_ROUND_SHIFT) - 1)
+
+/*
+ * FRAG_EXTRA 16 bits
+ *
+ * IF FRAG_WHOLE or FRAG_YES_NOTLAST, these 16 bits are available (not currently used)
+ */
+
+/* FRAG_EXTRA 16 bits */
+#define FRAG_EXTRA_MASK         0x0000ffff
+#define FRAG_EXTRA_SHIFT        15
+
+/*
+ * Public functions
+ */
+
+struct fragment_master *fragment_init (struct frame *frame);
+
+void fragment_frame_init (struct fragment_master *f, const struct frame *frame);
+
+void fragment_free (struct fragment_master *f);
+
+void fragment_incoming (struct fragment_master *f, struct buffer *buf,
+			const struct frame* frame);
+
+void fragment_outgoing (struct fragment_master *f, struct buffer *buf,
+			const struct frame* frame);
+
+bool fragment_ready_to_send (struct fragment_master *f, struct buffer *buf,
+			     const struct frame* frame);
+
+/*
+ * Private functions.
+ */
+void fragment_wakeup (struct fragment_master *f, struct frame *frame);
+
+/*
+ * Inline functions
+ */
+
+static inline void
+fragment_housekeeping (struct fragment_master *f, struct frame *frame, struct timeval *tv)
+{
+  if (event_timeout_trigger (&f->wakeup, tv, ETT_DEFAULT))
+    fragment_wakeup (f, frame);
+}
+
+static inline bool
+fragment_outgoing_defined (struct fragment_master *f)
+{
+  return f->outgoing.len > 0;
+}
+
+#endif
+#endif