lib/gnutls_dtls.h

   1 /*
   2  * Copyright (C) 2009-2012 Free Software Foundation, Inc.
   3  *
   4  * Author: Jonathan Bastien-Filiatrault
   5  *
   6  * This file is part of GNUTLS.
   7  *
   8  * The GNUTLS library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public License
  10  * as published by the Free Software Foundation; either version 3 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public License
  19  * along with this program.  If not, see <http://www.gnu.org/licenses/>
  20  *
  21  */
  22
  23 #ifndef DTLS_H
  24 # define DTLS_H
  25
  26 #include <config.h>
  27 #include <gnutls_int.h>
  28 #include <gnutls_buffers.h>
  29 #include <gnutls_mbuffers.h>
  30 #include <gnutls_constate.h>
  31 #include <timespec.h>
  32
  33 int _dtls_transmit(gnutls_session_t session);
  34 int _dtls_retransmit(gnutls_session_t session);
  35 int _dtls_record_check(struct record_parameters_st *rp, uint64 * _seq);
  36 void _dtls_reset_hsk_state(gnutls_session_t session);
  37
  38 #define MAX_DTLS_TIMEOUT 60000
  39
  40 unsigned int _dtls_timespec_sub_ms (struct timespec *a, struct timespec *b);
  41
  42 #define RETURN_DTLS_EAGAIN_OR_TIMEOUT(session, r) { \
  43   struct timespec now; \
  44   unsigned int diff; \
  45   gettime(&now); \
  46    \
  47   diff = _dtls_timespec_sub_ms(&now, &session->internals.dtls.handshake_start_time); \
  48   if (diff > session->internals.dtls.total_timeout_ms) \
  49     { \
  50       _gnutls_dtls_log("Session timeout: %u ms\n", diff); \
  51       return gnutls_assert_val(GNUTLS_E_TIMEDOUT); \
  52     } \
  53   else \
  54     { \
  55       int rr; \
  56       if (r != GNUTLS_E_INTERRUPTED) rr = GNUTLS_E_AGAIN; \
  57       else rr = r; \
  58       if (session->internals.dtls.blocking != 0) \
  59         millisleep(50); \
  60       return gnutls_assert_val(rr); \
  61     } \
  62   }
  63
  64
  65 int _dtls_wait_and_retransmit(gnutls_session_t session);
  66
  67 /* returns true or false depending on whether we need to
  68  * handle asynchronously handshake data.
  69  */
  70 inline static int _dtls_is_async(gnutls_session_t session)
  71 {
  72   if ((session->security_parameters.entity == GNUTLS_SERVER && session->internals.resumed == RESUME_FALSE) ||
  73          (session->security_parameters.entity == GNUTLS_CLIENT && session->internals.resumed == RESUME_TRUE))
  74     return 1;
  75   else
  76     return 0;
  77 }
  78
  79 inline static void _dtls_async_timer_init(gnutls_session_t session)
  80 {
  81   if (_dtls_is_async(session))
  82     {
  83       _gnutls_dtls_log ("DTLS[%p]: Initializing timer for handshake state.\n", session);
  84       session->internals.dtls.async_term = gnutls_time(0) + MAX_DTLS_TIMEOUT/1000;
  85     }
  86   else
  87     {
  88       _dtls_reset_hsk_state(session);
  89       _gnutls_handshake_io_buffer_clear (session);
  90       _gnutls_epoch_gc(session);
  91       session->internals.dtls.async_term = 0;
  92     }
  93 }
  94
  95 void _dtls_async_timer_delete(gnutls_session_t session);
  96
  97 /* Checks whether it is time to terminate the timer
  98  */
  99 inline static void _dtls_async_timer_check(gnutls_session_t session)
 100 {
 101   if (!IS_DTLS(session))
 102     return;
 103
 104   if (session->internals.dtls.async_term != 0)
 105     {
 106       time_t now = time(0);
 107
 108       /* check if we need to expire the queued handshake data */
 109       if (now > session->internals.dtls.async_term)
 110         {
 111           _dtls_async_timer_delete(session);
 112         }
 113     }
 114 }
 115
 116 /* Returns non-zero if the async timer is active */
 117 inline static int _dtls_async_timer_active(gnutls_session_t session)
 118 {
 119   if (!IS_DTLS(session))
 120     return 0;
 121
 122   return session->internals.dtls.async_term;
 123 }
 124
 125 #endif