stun/utils.c

   1 /*
   2  * This file is part of the Nice GLib ICE library.
   3  *
   4  * (C) 2008-2009 Collabora Ltd.
   5  *  Contact: Youness Alaoui
   6  * (C) 2007-2009 Nokia Corporation. All rights reserved.
   7  *  Contact: Rémi Denis-Courmont
   8  *
   9  * The contents of this file are subject to the Mozilla Public License Version
  10  * 1.1 (the "License"); you may not use this file except in compliance with
  11  * the License. You may obtain a copy of the License at
  12  * http://www.mozilla.org/MPL/
  13  *
  14  * Software distributed under the License is distributed on an "AS IS" basis,
  15  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  16  * for the specific language governing rights and limitations under the
  17  * License.
  18  *
  19  * The Original Code is the Nice GLib ICE library.
  20  *
  21  * The Initial Developers of the Original Code are Collabora Ltd and Nokia
  22  * Corporation. All Rights Reserved.
  23  *
  24  * Contributors:
  25  *   Youness Alaoui, Collabora Ltd.
  26  *   Olivier Crete, Collabora Ltd.
  27  *   Kai Vehmanen, Nokia
  28  *
  29  * Alternatively, the contents of this file may be used under the terms of the
  30  * the GNU Lesser General Public License Version 2.1 (the "LGPL"), in which
  31  * case the provisions of LGPL are applicable instead of those above. If you
  32  * wish to allow use of your version of this file only under the terms of the
  33  * LGPL and not to allow others to use your version of this file under the
  34  * MPL, indicate your decision by deleting the provisions above and replace
  35  * them with the notice and other provisions required by the LGPL. If you do
  36  * not delete the provisions above, a recipient may use your version of this
  37  * file under either the MPL or the LGPL.
  38  */
  39
  40 #ifdef HAVE_CONFIG_H
  41 # include <config.h>
  42 #endif
  43
  44 #include <string.h>
  45 #include <stdlib.h>
  46 #include <stdio.h>
  47 #include <stdarg.h>
  48
  49 #include "utils.h"
  50
  51 size_t stun_padding (size_t l)
  52 {
  53   return (4 - (l & 3)) & 3;
  54 }
  55
  56 size_t stun_align (size_t l)
  57 {
  58   return (l + 3) & ~3;
  59 }
  60
  61
  62 uint16_t stun_getw (const uint8_t *ptr)
  63 {
  64   return ((ptr)[0] << 8) | ptr[1];
  65 }
  66
  67
  68 void *stun_setw (uint8_t *ptr, uint16_t value)
  69 {
  70   *ptr++ = value >> 8;
  71   *ptr++ = value & 0xff;
  72   return ptr;
  73 }
  74
  75
  76 void stun_set_type (uint8_t *h, StunClass c, StunMethod m)
  77 {
  78 /*   assert (c < 4); */
  79 /*   assert (m < (1 << 12)); */
  80
  81   h[0] = (c >> 1) | ((m >> 6) & 0x3e);
  82   h[1] = ((c << 4) & 0x10) | ((m << 1) & 0xe0) | (m & 0x0f);
  83
  84 /*   assert (stun_getw (h) < (1 << 14)); */
  85 /*   assert (stun_get_class (h) == c); */
  86 /*   assert (stun_get_method (h) == m); */
  87 }
  88
  89
  90 StunMessageReturn stun_xor_address (const StunMessage *msg,
  91     struct sockaddr *addr, socklen_t addrlen,
  92     uint32_t magic_cookie)
  93 {
  94   switch (addr->sa_family)
  95   {
  96     case AF_INET:
  97     {
  98       struct sockaddr_in *ip4 = (struct sockaddr_in *)addr;
  99       if ((size_t) addrlen < sizeof (*ip4))
 100         return STUN_MESSAGE_RETURN_INVALID;
 101
 102       ip4->sin_port ^= htons (magic_cookie >> 16);
 103       ip4->sin_addr.s_addr ^= htonl (magic_cookie);
 104       return STUN_MESSAGE_RETURN_SUCCESS;
 105     }
 106
 107     case AF_INET6:
 108     {
 109       struct sockaddr_in6 *ip6 = (struct sockaddr_in6 *)addr;
 110       unsigned short i;
 111
 112       if ((size_t) addrlen < sizeof (*ip6))
 113         return STUN_MESSAGE_RETURN_INVALID;
 114
 115       ip6->sin6_port ^= htons (magic_cookie >> 16);
 116       for (i = 0; i < 16; i++)
 117         ip6->sin6_addr.s6_addr[i] ^= msg->buffer[4 + i];
 118       return STUN_MESSAGE_RETURN_SUCCESS;
 119     }
 120   }
 121   return STUN_MESSAGE_RETURN_UNSUPPORTED_ADDRESS;
 122 }