coturn/src/client/ns_turn_msg_addr.c

/*
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * https://opensource.org/license/bsd-3-clause
 *
 * Copyright (C) 2011, 2012, 2013 Citrix Systems
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "ns_turn_msg_addr.h"
#include "ns_turn_defs.h" // for nswap16, nswap32

#include <string.h> // for memcpy

//////////////////////////////////////////////////////////////////////////////

int stun_addr_encode(const ioa_addr *ca, uint8_t *cfield, int *clen, int xor_ed, uint32_t mc, const uint8_t *tsx_id) {

  if (!cfield || !clen || !ca || !tsx_id) {
    return -1;
  }

  if (ca->ss.sa_family == AF_INET || ca->ss.sa_family == 0) {

    /* IPv4 address */

    *clen = 8;

    cfield[0] = 0;
    cfield[1] = 1; // IPv4 family

    if (xor_ed) {

      /* Port */
      ((uint16_t *)cfield)[1] = (ca->s4.sin_port) ^ nswap16(mc >> 16);

      /* Address */
      ((uint32_t *)cfield)[1] = (ca->s4.sin_addr.s_addr) ^ nswap32(mc);

    } else {

      /* Port */
      ((uint16_t *)cfield)[1] = ca->s4.sin_port;

      /* Address */
      ((uint32_t *)cfield)[1] = ca->s4.sin_addr.s_addr;
    }

  } else if (ca->ss.sa_family == AF_INET6) {

    /* IPv6 address */

    *clen = 20;

    cfield[0] = 0;
    cfield[1] = 2; // IPv6 family

    if (xor_ed) {

      unsigned int i;
      uint8_t *dst = ((uint8_t *)cfield) + 4;
      const uint8_t *src = (const uint8_t *)&(ca->s6.sin6_addr);
      uint32_t magic = nswap32(mc);

      /* Port */
      ((uint16_t *)cfield)[1] = ca->s6.sin6_port ^ nswap16(mc >> 16);

      /* Address */

      for (i = 0; i < 4; ++i) {
        dst[i] = (uint8_t)(src[i] ^ ((const uint8_t *)&magic)[i]);
      }
      for (i = 0; i < 12; ++i) {
        dst[i + 4] = (uint8_t)(src[i + 4] ^ tsx_id[i]);
      }

    } else {

      /* Port */
      ((uint16_t *)cfield)[1] = ca->s6.sin6_port;

      /* Address */
      memcpy(((uint8_t *)cfield) + 4, &ca->s6.sin6_addr, 16);
    }

  } else {
    return -1;
  }

  return 0;
}

int stun_addr_decode(ioa_addr *ca, const uint8_t *cfield, int len, int xor_ed, uint32_t mc, const uint8_t *tsx_id) {

  if (!cfield || !len || !ca || !tsx_id || (len < 8)) {
    return -1;
  }

  if (cfield[0] != 0) {
    return -1;
  }

  int sa_family;

  if (cfield[1] == 1) {
    sa_family = AF_INET;
  } else if (cfield[1] == 2) {
    sa_family = AF_INET6;
  } else {
    return -1;
  }

  ca->ss.sa_family = sa_family;

  if (sa_family == AF_INET) {

    if (len != 8) {
      return -1;
    }

    /* IPv4 address */

    /* Port */
    ca->s4.sin_port = ((const uint16_t *)cfield)[1];

    /* Address */
    ca->s4.sin_addr.s_addr = ((const uint32_t *)cfield)[1];

    if (xor_ed) {
      ca->s4.sin_port ^= nswap16(mc >> 16);
      ca->s4.sin_addr.s_addr ^= nswap32(mc);
    }

  } else if (sa_family == AF_INET6) {

    /* IPv6 address */

    if (len != 20) {
      return -1;
    }

    /* Port */
    ca->s6.sin6_port = ((const uint16_t *)cfield)[1];

    /* Address */
    memcpy(&ca->s6.sin6_addr, ((const uint8_t *)cfield) + 4, 16);

    if (xor_ed) {

      unsigned int i;
      uint8_t *dst;
      const uint8_t *src;
      uint32_t magic = nswap32(mc);

      /* Port */
      ca->s6.sin6_port ^= nswap16(mc >> 16);

      /* Address */
      src = ((const uint8_t *)cfield) + 4;
      dst = (uint8_t *)&ca->s6.sin6_addr;
      for (i = 0; i < 4; ++i) {
        dst[i] = (uint8_t)(src[i] ^ ((const uint8_t *)&magic)[i]);
      }
      for (i = 0; i < 12; ++i) {
        dst[i + 4] = (uint8_t)(src[i + 4] ^ tsx_id[i]);
      }
    }

  } else {
    return -1;
  }

  return 0;
}

//////////////////////////////////////////////////////////////////////////////