release/src/router/openvpn/session_id.h

   1 /*
   2  *  OpenVPN -- An application to securely tunnel IP networks
   3  *             over a single UDP port, with support for SSL/TLS-based
   4  *             session authentication and key exchange,
   5  *             packet encryption, packet authentication, and
   6  *             packet compression.
   7  *
   8  *  Copyright (C) 2002-2009 OpenVPN Technologies, Inc. <sales@openvpn.net>
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License version 2
  12  *  as published by the Free Software Foundation.
  13  *
  14  *  This program is distributed in the hope that it will be useful,
  15  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *  GNU General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License
  20  *  along with this program (see the file COPYING included with this
  21  *  distribution); if not, write to the Free Software Foundation, Inc.,
  22  *  59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  23  */
  24
  25 /*
  26  * Each session is identified by a random 8-byte session identifier.
  27  *
  28  * For efficiency, the session id is only transmitted over the control
  29  * channel (which only sees traffic occasionally when keys are being
  30  * negotiated).
  31  */
  32
  33 #if defined(USE_CRYPTO) && defined(USE_SSL)
  34
  35 #ifndef SESSION_ID_H
  36 #define SESSION_ID_H
  37
  38 #include "basic.h"
  39 #include "buffer.h"
  40
  41 struct session_id
  42 {
  43   uint8_t id[8];
  44 };
  45
  46 extern const struct session_id x_session_id_zero;
  47
  48 #define SID_SIZE (sizeof (x_session_id_zero.id))
  49
  50 static inline bool
  51 session_id_equal (const struct session_id *sid1,
  52                   const struct session_id *sid2)
  53 {
  54   return !memcmp (sid1->id, sid2->id, SID_SIZE);
  55 }
  56
  57 static inline bool
  58 session_id_defined (const struct session_id *sid1)
  59 {
  60   return memcmp (sid1->id, &x_session_id_zero.id, SID_SIZE) != 0;
  61 }
  62
  63 static inline bool
  64 session_id_read (struct session_id *sid, struct buffer *buf)
  65 {
  66   return buf_read (buf, sid->id, SID_SIZE);
  67 }
  68
  69 static inline bool
  70 session_id_write_prepend (const struct session_id *sid, struct buffer *buf)
  71 {
  72   return buf_write_prepend (buf, sid->id, SID_SIZE);
  73 }
  74
  75 static inline bool
  76 session_id_write (const struct session_id *sid, struct buffer *buf)
  77 {
  78   return buf_write (buf, sid->id, SID_SIZE);
  79 }
  80
  81 void session_id_random (struct session_id *sid);
  82
  83 const char *session_id_print (const struct session_id *sid, struct gc_arena *gc);
  84
  85 #endif /* SESSION_ID_H */
  86 #endif /* USE_CRYPTO && USE_SSL */