Imported Upstream version 2.3_rc1

1 files changed, 399 insertions, 0 deletions

diff --git a/src/openvpn/occ.c b/src/openvpn/occ.c
new file mode 100644
index 0000000..ff48706
--- /dev/null
+++ b/src/openvpn/occ.c
@@ -0,0 +1,399 @@
+/*
+ *  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
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#elif defined(_MSC_VER)
+#include "config-msvc.h"
+#endif
+
+#include "syshead.h"
+
+#ifdef ENABLE_OCC
+
+#include "occ.h"
+
+#include "memdbg.h"
+
+#include "forward-inline.h"
+#include "occ-inline.h"
+
+/*
+ * This random string identifies an OpenVPN
+ * Configuration Control packet.
+ * It should be of sufficient length and randomness
+ * so as not to collide with other tunnel data.
+ *
+ * The OCC protocol is as follows:
+ *
+ * occ_magic -- (16 octets)
+ *
+ * type [OCC_REQUEST | OCC_REPLY] (1 octet)
+ * null terminated options string if OCC_REPLY (variable)
+ *
+ * When encryption is used, the OCC packet
+ * is encapsulated within the encrypted
+ * envelope.
+ *
+ * OCC_STRING_SIZE must be set to sizeof (occ_magic)
+ */
+
+const uint8_t occ_magic[] = {
+  0x28, 0x7f, 0x34, 0x6b, 0xd4, 0xef, 0x7a, 0x81,
+  0x2d, 0x56, 0xb8, 0xd3, 0xaf, 0xc5, 0x45, 0x9c
+};
+
+static const struct mtu_load_test mtu_load_test_sequence[] = {
+
+  {OCC_MTU_LOAD_REQUEST, -1000},
+  {OCC_MTU_LOAD, -1000},
+  {OCC_MTU_LOAD_REQUEST, -1000},
+  {OCC_MTU_LOAD, -1000},
+  {OCC_MTU_LOAD_REQUEST, -1000},
+  {OCC_MTU_LOAD, -1000},
+
+  {OCC_MTU_LOAD_REQUEST, -750},
+  {OCC_MTU_LOAD, -750},
+  {OCC_MTU_LOAD_REQUEST, -750},
+  {OCC_MTU_LOAD, -750},
+  {OCC_MTU_LOAD_REQUEST, -750},
+  {OCC_MTU_LOAD, -750},
+
+  {OCC_MTU_LOAD_REQUEST, -500},
+  {OCC_MTU_LOAD, -500},
+  {OCC_MTU_LOAD_REQUEST, -500},
+  {OCC_MTU_LOAD, -500},
+  {OCC_MTU_LOAD_REQUEST, -500},
+  {OCC_MTU_LOAD, -500},
+
+  {OCC_MTU_LOAD_REQUEST, -400},
+  {OCC_MTU_LOAD, -400},
+  {OCC_MTU_LOAD_REQUEST, -400},
+  {OCC_MTU_LOAD, -400},
+  {OCC_MTU_LOAD_REQUEST, -400},
+  {OCC_MTU_LOAD, -400},
+
+  {OCC_MTU_LOAD_REQUEST, -300},
+  {OCC_MTU_LOAD, -300},
+  {OCC_MTU_LOAD_REQUEST, -300},
+  {OCC_MTU_LOAD, -300},
+  {OCC_MTU_LOAD_REQUEST, -300},
+  {OCC_MTU_LOAD, -300},
+
+  {OCC_MTU_LOAD_REQUEST, -200},
+  {OCC_MTU_LOAD, -200},
+  {OCC_MTU_LOAD_REQUEST, -200},
+  {OCC_MTU_LOAD, -200},
+  {OCC_MTU_LOAD_REQUEST, -200},
+  {OCC_MTU_LOAD, -200},
+
+  {OCC_MTU_LOAD_REQUEST, -150},
+  {OCC_MTU_LOAD, -150},
+  {OCC_MTU_LOAD_REQUEST, -150},
+  {OCC_MTU_LOAD, -150},
+  {OCC_MTU_LOAD_REQUEST, -150},
+  {OCC_MTU_LOAD, -150},
+
+  {OCC_MTU_LOAD_REQUEST, -100},
+  {OCC_MTU_LOAD, -100},
+  {OCC_MTU_LOAD_REQUEST, -100},
+  {OCC_MTU_LOAD, -100},
+  {OCC_MTU_LOAD_REQUEST, -100},
+  {OCC_MTU_LOAD, -100},
+
+  {OCC_MTU_LOAD_REQUEST, -50},
+  {OCC_MTU_LOAD, -50},
+  {OCC_MTU_LOAD_REQUEST, -50},
+  {OCC_MTU_LOAD, -50},
+  {OCC_MTU_LOAD_REQUEST, -50},
+  {OCC_MTU_LOAD, -50},
+
+  {OCC_MTU_LOAD_REQUEST, 0},
+  {OCC_MTU_LOAD, 0},
+  {OCC_MTU_LOAD_REQUEST, 0},
+  {OCC_MTU_LOAD, 0},
+  {OCC_MTU_LOAD_REQUEST, 0},
+  {OCC_MTU_LOAD, 0},
+
+  {OCC_MTU_REQUEST, 0},
+  {OCC_MTU_REQUEST, 0},
+  {OCC_MTU_REQUEST, 0},
+  {OCC_MTU_REQUEST, 0},
+  {OCC_MTU_REQUEST, 0},
+  {OCC_MTU_REQUEST, 0},
+  {OCC_MTU_REQUEST, 0},
+  {OCC_MTU_REQUEST, 0},
+  {OCC_MTU_REQUEST, 0},
+  {OCC_MTU_REQUEST, 0},
+
+  {-1, 0}
+};
+
+void
+check_send_occ_req_dowork (struct context *c)
+{
+  if (++c->c2.occ_n_tries >= OCC_N_TRIES)
+    {
+      if (c->options.ce.remote)
+	/*
+	 * No OCC_REPLY from peer after repeated attempts.
+	 * Give up.
+	 */
+	msg (D_SHOW_OCC,
+	     "NOTE: failed to obtain options consistency info from peer -- "
+	     "this could occur if the remote peer is running a version of "
+	     PACKAGE_NAME
+	     " before 1.5-beta8 or if there is a network connectivity problem, and will not necessarily prevent "
+	     PACKAGE_NAME
+             " from running (" counter_format " bytes received from peer, " counter_format
+	     " bytes authenticated data channel traffic) -- you can disable the options consistency "
+	     "check with --disable-occ.",
+             c->c2.link_read_bytes,
+             c->c2.link_read_bytes_auth);
+      event_timeout_clear (&c->c2.occ_interval);
+    }
+  else
+    {
+      c->c2.occ_op = OCC_REQUEST;
+
+      /*
+       * If we don't hear back from peer, send another
+       * OCC_REQUEST in OCC_INTERVAL_SECONDS.
+       */
+      event_timeout_reset (&c->c2.occ_interval);
+    }
+}
+
+void
+check_send_occ_load_test_dowork (struct context *c)
+{
+  if (CONNECTION_ESTABLISHED (c))
+    {
+      const struct mtu_load_test *entry;
+
+      if (!c->c2.occ_mtu_load_n_tries)
+	msg (M_INFO,
+	     "NOTE: Beginning empirical MTU test -- results should be available in 3 to 4 minutes.");
+
+      entry = &mtu_load_test_sequence[c->c2.occ_mtu_load_n_tries++];
+      if (entry->op >= 0)
+	{
+	  c->c2.occ_op = entry->op;
+	  c->c2.occ_mtu_load_size =
+	    EXPANDED_SIZE (&c->c2.frame) + entry->delta;
+	}
+      else
+	{
+	  msg (M_INFO,
+	       "NOTE: failed to empirically measure MTU (requires " PACKAGE_NAME " 1.5 or higher at other end of connection).");
+	  event_timeout_clear (&c->c2.occ_mtu_load_test_interval);
+	  c->c2.occ_mtu_load_n_tries = 0;
+	}
+    }
+}
+
+void
+check_send_occ_msg_dowork (struct context *c)
+{
+  bool doit = false;
+
+  c->c2.buf = c->c2.buffers->aux_buf;
+  ASSERT (buf_init (&c->c2.buf, FRAME_HEADROOM (&c->c2.frame)));
+  ASSERT (buf_safe (&c->c2.buf, MAX_RW_SIZE_TUN (&c->c2.frame)));
+  ASSERT (buf_write (&c->c2.buf, occ_magic, OCC_STRING_SIZE));
+
+  switch (c->c2.occ_op)
+    {
+    case OCC_REQUEST:
+      if (!buf_write_u8 (&c->c2.buf, OCC_REQUEST))
+	break;
+      dmsg (D_PACKET_CONTENT, "SENT OCC_REQUEST");
+      doit = true;
+      break;
+
+    case OCC_REPLY:
+      if (!c->c2.options_string_local)
+	break;
+      if (!buf_write_u8 (&c->c2.buf, OCC_REPLY))
+	break;
+      if (!buf_write (&c->c2.buf, c->c2.options_string_local,
+		      strlen (c->c2.options_string_local) + 1))
+	break;
+      dmsg (D_PACKET_CONTENT, "SENT OCC_REPLY");
+      doit = true;
+      break;
+
+    case OCC_MTU_REQUEST:
+      if (!buf_write_u8 (&c->c2.buf, OCC_MTU_REQUEST))
+	break;
+      dmsg (D_PACKET_CONTENT, "SENT OCC_MTU_REQUEST");
+      doit = true;
+      break;
+
+    case OCC_MTU_REPLY:
+      if (!buf_write_u8 (&c->c2.buf, OCC_MTU_REPLY))
+	break;
+      if (!buf_write_u16 (&c->c2.buf, c->c2.max_recv_size_local))
+	break;
+      if (!buf_write_u16 (&c->c2.buf, c->c2.max_send_size_local))
+	break;
+      dmsg (D_PACKET_CONTENT, "SENT OCC_MTU_REPLY");
+      doit = true;
+      break;
+
+    case OCC_MTU_LOAD_REQUEST:
+      if (!buf_write_u8 (&c->c2.buf, OCC_MTU_LOAD_REQUEST))
+	break;
+      if (!buf_write_u16 (&c->c2.buf, c->c2.occ_mtu_load_size))
+	break;
+      dmsg (D_PACKET_CONTENT, "SENT OCC_MTU_LOAD_REQUEST");
+      doit = true;
+      break;
+
+    case OCC_MTU_LOAD:
+      {
+	int need_to_add;
+
+	if (!buf_write_u8 (&c->c2.buf, OCC_MTU_LOAD))
+	  break;
+	need_to_add = min_int (c->c2.occ_mtu_load_size, EXPANDED_SIZE (&c->c2.frame))
+			       - OCC_STRING_SIZE
+			       - sizeof (uint8_t)
+	                       - EXTRA_FRAME (&c->c2.frame);
+
+	while (need_to_add > 0)
+	  {
+	    /*
+	     * Fill the load test packet with pseudo-random bytes.
+	     */
+	    if (!buf_write_u8 (&c->c2.buf, get_random () & 0xFF))
+	      break;
+	    --need_to_add;
+	  }
+	dmsg (D_PACKET_CONTENT, "SENT OCC_MTU_LOAD min_int(%d-%d-%d-%d,%d) size=%d",
+	     c->c2.occ_mtu_load_size,
+	     OCC_STRING_SIZE,
+	      (int) sizeof (uint8_t),
+	     EXTRA_FRAME (&c->c2.frame),
+	     MAX_RW_SIZE_TUN (&c->c2.frame),
+	     BLEN (&c->c2.buf));
+	doit = true;
+      }
+      break;
+
+    case OCC_EXIT:
+      if (!buf_write_u8 (&c->c2.buf, OCC_EXIT))
+	break;
+      dmsg (D_PACKET_CONTENT, "SENT OCC_EXIT");
+      doit = true;
+      break;
+    }
+
+  if (doit)
+    {
+      /*
+       * We will treat the packet like any other outgoing packet,
+       * compress, encrypt, sign, etc.
+       */
+      encrypt_sign (c, true);
+    }
+
+  c->c2.occ_op = -1;
+}
+
+void
+process_received_occ_msg (struct context *c)
+{
+  ASSERT (buf_advance (&c->c2.buf, OCC_STRING_SIZE));
+  switch (buf_read_u8 (&c->c2.buf))
+    {
+    case OCC_REQUEST:
+      dmsg (D_PACKET_CONTENT, "RECEIVED OCC_REQUEST");
+      c->c2.occ_op = OCC_REPLY;
+      break;
+
+    case OCC_MTU_REQUEST:
+      dmsg (D_PACKET_CONTENT, "RECEIVED OCC_MTU_REQUEST");
+      c->c2.occ_op = OCC_MTU_REPLY;
+      break;
+
+    case OCC_MTU_LOAD_REQUEST:
+      dmsg (D_PACKET_CONTENT, "RECEIVED OCC_MTU_LOAD_REQUEST");
+      c->c2.occ_mtu_load_size = buf_read_u16 (&c->c2.buf);
+      if (c->c2.occ_mtu_load_size >= 0)
+	c->c2.occ_op = OCC_MTU_LOAD;
+      break;
+
+    case OCC_REPLY:
+      dmsg (D_PACKET_CONTENT, "RECEIVED OCC_REPLY");
+      if (c->options.occ && !TLS_MODE (c) && c->c2.options_string_remote)
+	{
+	  if (!options_cmp_equal_safe ((char *) BPTR (&c->c2.buf),
+				       c->c2.options_string_remote,
+				       c->c2.buf.len))
+	    {
+	      options_warning_safe ((char *) BPTR (&c->c2.buf),
+				    c->c2.options_string_remote,
+				    c->c2.buf.len);
+	    }
+	}
+      event_timeout_clear (&c->c2.occ_interval);
+      break;
+
+    case OCC_MTU_REPLY:
+      dmsg (D_PACKET_CONTENT, "RECEIVED OCC_MTU_REPLY");
+      c->c2.max_recv_size_remote = buf_read_u16 (&c->c2.buf);
+      c->c2.max_send_size_remote = buf_read_u16 (&c->c2.buf);
+      if (c->options.mtu_test
+	  && c->c2.max_recv_size_remote > 0
+	  && c->c2.max_send_size_remote > 0)
+	{
+	  msg (M_INFO, "NOTE: Empirical MTU test completed [Tried,Actual] local->remote=[%d,%d] remote->local=[%d,%d]",
+	       c->c2.max_send_size_local,
+	       c->c2.max_recv_size_remote,
+	       c->c2.max_send_size_remote,
+	       c->c2.max_recv_size_local);
+	  if (!c->options.ce.fragment
+	      && (proto_is_dgram(c->options.ce.proto))
+	      && c->c2.max_send_size_local > TUN_MTU_MIN
+	      && (c->c2.max_recv_size_remote < c->c2.max_send_size_local
+		  || c->c2.max_recv_size_local < c->c2.max_send_size_remote))
+	    msg (M_INFO, "NOTE: This connection is unable to accomodate a UDP packet size of %d. Consider using --fragment or --mssfix options as a workaround.",
+		 c->c2.max_send_size_local);
+	}
+      event_timeout_clear (&c->c2.occ_mtu_load_test_interval);
+      break;
+
+    case OCC_EXIT:
+      dmsg (D_PACKET_CONTENT, "RECEIVED OCC_EXIT");
+      c->sig->signal_received = SIGTERM;
+      c->sig->signal_text = "remote-exit";
+      break;
+    }
+  c->c2.buf.len = 0; /* don't pass packet on */
+}
+
+#else
+static void dummy(void) {}
+#endif