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stun.c
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/*
* This file is part of the Nice GLib ICE library.
*
* (C) 2006-2009 Collabora Ltd.
* Contact: Youness Alaoui
* (C) 2006-2009 Nokia Corporation. All rights reserved.
* Contact: Kai Vehmanen
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is the Nice GLib ICE library.
*
* The Initial Developers of the Original Code are Collabora Ltd and Nokia
* Corporation. All Rights Reserved.
*
* Contributors:
* Dafydd Harries, Collabora Ltd.
* Youness Alaoui, Collabora Ltd.
* Kai Vehmanen, Nokia
*
* Alternatively, the contents of this file may be used under the terms of the
* the GNU Lesser General Public License Version 2.1 (the "LGPL"), in which
* case the provisions of LGPL are applicable instead of those above. If you
* wish to allow use of your version of this file only under the terms of the
* LGPL and not to allow others to use your version of this file under the
* MPL, indicate your decision by deleting the provisions above and replace
* them with the notice and other provisions required by the LGPL. If you do
* not delete the provisions above, a recipient may use your version of this
* file under either the MPL or the LGPL.
*/
/*
* Porting to C library using libevent.
* Jackie Dinh - 2016
*/
#include "cice/stun.h"
#include "cice/stun/constants.h"
#include "cice/stun/stunmessage.h"
#include "cice/stun/utils.h"
size_t
is_stun_message(uint8_t *buffer, int len, int has_padding) {
int mlen;
//ICE_DEBUG("STUN info, has_padding=%u",has_padding);
if (len < 1 || buffer == NULL) {
ICE_ERROR("STUN error: No data!");
return STUN_MESSAGE_BUFFER_INVALID;
}
if (buffer[0] >> 6) {
ICE_DEBUG("STUN error: RTP or other non-protocol packet!");
return STUN_MESSAGE_BUFFER_INVALID; // RTP or other non-STUN packet
}
if (len < STUN_MESSAGE_LENGTH_POS + STUN_MESSAGE_LENGTH_LEN) {
ICE_DEBUG("STUN error: Incomplete STUN message header!");
return STUN_MESSAGE_BUFFER_INCOMPLETE;
}
mlen = stun_getw((uint8_t*)buffer + STUN_MESSAGE_LENGTH_POS);
mlen += STUN_MESSAGE_HEADER_LENGTH;
if (has_padding && stun_padding (mlen)) {
ICE_DEBUG("STUN error: Invalid message length: %u!", (unsigned)mlen);
return STUN_MESSAGE_BUFFER_INVALID; // wrong padding
}
if (len < mlen) {
ICE_DEBUG("STUN error: Incomplete message: %u of %u bytes!",
(unsigned) len, (unsigned) mlen);
return STUN_MESSAGE_BUFFER_INCOMPLETE; // partial message
}
return mlen;
}
int
is_validated_stun_message(uint8_t *msg, int length, int has_padding) {
ssize_t fast_retval;
size_t mlen;
size_t len;
//FIXME: pre-check is really needed?
fast_retval = is_stun_message(msg,length,has_padding);
if ( fast_retval <= 0 )
return fast_retval;
mlen = fast_retval;
/* Skip past the header (validated above). */
msg += 20;
len = mlen - 20;
/* from then on, we know we have the entire packet in buffer */
while (len > 0)
{
size_t alen;
if (len < 4)
{
ICE_DEBUG("STUN error: Incomplete STUN attribute header of length "
"%u bytes!", (unsigned)len);
return STUN_MESSAGE_BUFFER_INVALID;
}
alen = stun_getw (msg + STUN_ATTRIBUTE_TYPE_LEN);
if (has_padding)
alen = stun_align (alen);
/* thanks to padding check, if (end > msg) then there is not only one
* but at least 4 bytes left */
len -= 4;
if (len < alen)
{
ICE_DEBUG("STUN error: %u instead of %u bytes for attribute!",
(unsigned)len, (unsigned)alen);
return STUN_MESSAGE_BUFFER_INVALID; // no room for attribute value + padding
}
len -= alen;
msg += 4 + alen;
}
ICE_DEBUG("stun msg, mlen=%lu",mlen);
return mlen;
}