Imported Upstream version 2.3_rc1

1 files changed, 242 insertions, 0 deletions

diff --git a/src/openvpn/forward.h b/src/openvpn/forward.h
new file mode 100644
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--- /dev/null
+++ b/src/openvpn/forward.h
@@ -0,0 +1,242 @@
+/*
+ *  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
+ */
+
+
+/**
+ * @file
+ * Interface functions to the internal and external multiplexers.
+ */
+
+
+#ifndef FORWARD_H
+#define FORWARD_H
+
+#include "openvpn.h"
+#include "occ.h"
+#include "ping.h"
+
+#define TUN_OUT(c)      (BLEN(&(c)->c2.to_tun) > 0)
+#define LINK_OUT(c)     (BLEN(&(c)->c2.to_link) > 0)
+#define ANY_OUT(c)      (TUN_OUT(c) || LINK_OUT(c))
+
+#ifdef ENABLE_FRAGMENT
+#define TO_LINK_FRAG(c) ((c)->c2.fragment && fragment_outgoing_defined ((c)->c2.fragment))
+#else
+#define TO_LINK_FRAG(c) (false)
+#endif
+
+#define TO_LINK_DEF(c)  (LINK_OUT(c) || TO_LINK_FRAG(c))
+
+#define IOW_TO_TUN          (1<<0)
+#define IOW_TO_LINK         (1<<1)
+#define IOW_READ_TUN        (1<<2)
+#define IOW_READ_LINK       (1<<3)
+#define IOW_SHAPER          (1<<4)
+#define IOW_CHECK_RESIDUAL  (1<<5)
+#define IOW_FRAG            (1<<6)
+#define IOW_MBUF            (1<<7)
+#define IOW_READ_TUN_FORCE  (1<<8)
+#define IOW_WAIT_SIGNAL     (1<<9)
+
+#define IOW_READ            (IOW_READ_TUN|IOW_READ_LINK)
+
+
+void pre_select (struct context *c);
+void process_io (struct context *c);
+
+const char *wait_status_string (struct context *c, struct gc_arena *gc);
+void show_wait_status (struct context *c);
+
+
+/**********************************************************************/
+/**
+ * Process a data channel packet that will be sent through a VPN tunnel.
+ * @ingroup data_control
+ *
+ * This function controls the processing of a data channel packet which
+ * will be sent through a VPN tunnel to a remote OpenVPN peer.  It's
+ * general structure is as follows:
+ * - Check that the client authentication has succeeded; if not, drop the
+ *   packet.
+ * - If the \a comp_frag argument is true:
+ *   - Call \c lzo_compress() of the \link Data Channel Compression
+ *     module\endlink to (possibly) compress the packet.
+ *   - Call \c fragment_outgoing() of the \link Data Channel Fragmentation
+ *     module\endlink to (possibly) fragment the packet.
+ * - Activate the \link Data Channel Crypto module\endlink to perform
+ *   security operations on the packet.
+ *   - Call \c tls_pre_encrypt() to choose the appropriate security
+ *     parameters for this packet.
+ *   - Call \c openvpn_encrypt() to encrypt and HMAC signed the packet.
+ *   - Call \c tls_post_encrypt() to prepend the one-byte OpenVPN header
+ *     and do some TLS accounting.
+ * - Place the resulting packet in \c c->c2.to_link so that it can be sent
+ *   over the external network interface to its remote destination by the
+ *   \link external_multiplexer External Multiplexer\endlink.
+ *
+ * @param c - The context structure of the VPN tunnel associated with this
+ *     packet.
+ * @param comp_frag - Whether to do packet compression and fragmentation.
+ *     This flag is set to true the first time a packet is processed.  If
+ *     the packet then gets fragmented, this function will be called again
+ *     once for each remaining fragment with this parameter set to false.
+ */
+void encrypt_sign (struct context *c, bool comp_frag);
+
+
+/**********************************************************************/
+/**
+ * Read a packet from the external network interface.
+ * @ingroup external_multiplexer
+ *
+ * The packet read from the external network interface is stored in \c
+ * c->c2.buf and its source address in \c c->c2.from.  If an error
+ * occurred, the length of \c c->c2.buf will be 0.
+ *
+ * OpenVPN running as client or as UDP server only has a single external
+ * network socket, so this function can be called with the single (client
+ * mode) or top level (UDP server) context as its argument. OpenVPN
+ * running as TCP server, on the other hand, has a network socket for each
+ * active VPN tunnel.  In that case this function must be called with the
+ * context associated with the appropriate VPN tunnel for which data is
+ * available to be read.
+ *
+ * @param c - The context structure which contains the external
+ *     network socket from which to read incoming packets.
+ */
+void read_incoming_link (struct context *c);
+
+
+/**
+ * Process a packet read from the external network interface.
+ * @ingroup external_multiplexer
+ *
+ * This function controls the processing of a data channel packet which
+ * has come out of a VPN tunnel.  It's high-level structure is as follows:
+ * - Verify that a nonzero length packet has been received from a valid
+ *   source address for the given context \a c.
+ * - Call \c tls_pre_decrypt(), which splits data channel and control
+ *   channel packets:
+ *   - If a data channel packet, the appropriate security parameters are
+ *     loaded.
+ *   - If a control channel packet, this function process is it and
+ *     afterwards sets the packet's buffer length to 0, so that the data
+ *     channel processing steps below will ignore it.
+ * - Call \c openvpn_decrypt() of the \link data_crypto Data Channel
+ *   Crypto module\endlink to authenticate and decrypt the packet using
+ *   the security parameters loaded by \c tls_pre_decrypt() above.
+ * - Call \c fragment_incoming() of the \link fragmentation Data Channel
+ *   Fragmentation module\endlink to reassemble the packet if it's
+ *   fragmented.
+ * - Call \c lzo_decompress() of the \link compression Data Channel
+ *   Compression module\endlink to decompress the packet if it's
+ *   compressed.
+ * - Place the resulting packet in \c c->c2.to_tun so that it can be sent
+ *   over the virtual tun/tap network interface to its local destination
+ *   by the \link internal_multiplexer Internal Multiplexer\endlink.
+ *
+ * @param c - The context structure of the VPN tunnel associated with the
+ *     packet.
+ */
+void process_incoming_link (struct context *c);
+
+
+/**
+ * Write a packet to the external network interface.
+ * @ingroup external_multiplexer
+ *
+ * This function writes the packet stored in \c c->c2.to_link to the
+ * external network device contained within \c c->c1.link_socket.
+ *
+ * If an error occurs, it is logged and the packet is dropped.
+ *
+ * @param c - The context structure of the VPN tunnel associated with the
+ *     packet.
+ */
+void process_outgoing_link (struct context *c);
+
+
+/**************************************************************************/
+/**
+ * Read a packet from the virtual tun/tap network interface.
+ * @ingroup internal_multiplexer
+ *
+ * This function reads a packet from the virtual tun/tap network device \c
+ * c->c1.tuntap and stores it in \c c->c2.buf.
+ *
+ * If an error occurs, it is logged and the packet is dropped.
+ *
+ * @param c - The context structure in which to store the received
+ *     packet.
+ */
+void read_incoming_tun (struct context *c);
+
+
+/**
+ * Process a packet read from the virtual tun/tap network interface.
+ * @ingroup internal_multiplexer
+ *
+ * This function calls \c encrypt_sign() of the \link data_control Data
+ * Channel Control module\endlink to process the packet.
+ *
+ * If an error occurs, it is logged and the packet is dropped.
+ *
+ * @param c - The context structure of the VPN tunnel associated with the
+ *     packet.
+ */
+void process_incoming_tun (struct context *c);
+
+
+/**
+ * Write a packet to the virtual tun/tap network interface.
+ * @ingroup internal_multiplexer
+ *
+ * This function writes the packet stored in \c c->c2.to_tun to the
+ * virtual tun/tap network device \c c->c1.tuntap.
+ *
+ * If an error occurs, it is logged and the packet is dropped.
+ *
+ * @param c - The context structure of the VPN tunnel associated with
+ *     the packet.
+ */
+void process_outgoing_tun (struct context *c);
+
+
+/**************************************************************************/
+
+bool send_control_channel_string (struct context *c, const char *str, int msglevel);
+
+#define PIPV4_PASSTOS         (1<<0)
+#define PIPV4_MSSFIX          (1<<1)
+#define PIPV4_OUTGOING        (1<<2)
+#define PIPV4_EXTRACT_DHCP_ROUTER (1<<3)
+#define PIPV4_CLIENT_NAT      (1<<4)
+
+void process_ipv4_header (struct context *c, unsigned int flags, struct buffer *buf);
+
+#if P2MP
+void schedule_exit (struct context *c, const int n_seconds, const int signal);
+#endif
+
+#endif /* FORWARD_H */