libtins/src/dot11/dot11_data.cpp

/*
 * Copyright (c) 2014, Matias Fontanini
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * 
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * * 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.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
 * OWNER 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 "dot11/dot11_data.h"
#ifdef HAVE_DOT11

#include <cstring>
#include <cassert>
#include "rawpdu.h"
#include "snap.h"

namespace Tins {
/* Dot11Data */

Dot11Data::Dot11Data(const uint8_t *buffer, uint32_t total_sz) 
: Dot11(buffer, total_sz)
{
    const uint32_t offset = init(buffer, total_sz);
    buffer += offset;
    total_sz -= offset;
    if(total_sz) {
        // If the wep bit is on, then just use a RawPDU
        if(wep())
            inner_pdu(new Tins::RawPDU(buffer, total_sz));
        else
            inner_pdu(new Tins::SNAP(buffer, total_sz));
    }
}

Dot11Data::Dot11Data(const uint8_t *buffer, uint32_t total_sz, no_inner_pdu) 
: Dot11(buffer, total_sz)
{
    init(buffer, total_sz);
}

uint32_t Dot11Data::init(const uint8_t *buffer, uint32_t total_sz) {
    const uint8_t *start_ptr = buffer;
    uint32_t sz = Dot11::header_size();
    buffer += sz;
    total_sz -= sz;
    if(total_sz < sizeof(_ext_header))
        throw malformed_packet();
    std::memcpy(&_ext_header, buffer, sizeof(_ext_header));
    buffer += sizeof(_ext_header);
    total_sz -= sizeof(_ext_header);
    if(from_ds() && to_ds()) {
        if(total_sz < _addr4.size())
            throw malformed_packet();
        _addr4 = buffer;
        buffer += _addr4.size();
        total_sz -= _addr4.size();
    }
    return buffer - start_ptr;
}

Dot11Data::Dot11Data(const address_type &dst_hw_addr, 
  const address_type &src_hw_addr) 
: Dot11(dst_hw_addr) 
{
    type(Dot11::DATA);
    memset(&_ext_header, 0, sizeof(_ext_header));
    addr2(src_hw_addr);
}

uint32_t Dot11Data::header_size() const {
    uint32_t sz = Dot11::header_size() + sizeof(_ext_header);
    if (this->from_ds() && this->to_ds())
        sz += 6;
    return sz;
}

void Dot11Data::addr2(const address_type &new_addr2) {
    std::copy(new_addr2.begin(), new_addr2.end(), _ext_header.addr2);
}

void Dot11Data::addr3(const address_type &new_addr3) {
    std::copy(new_addr3.begin(), new_addr3.end(), _ext_header.addr3);
}

void Dot11Data::frag_num(small_uint<4> new_frag_num) {
    #if TINS_IS_LITTLE_ENDIAN
    _ext_header.frag_seq = new_frag_num | (_ext_header.frag_seq & 0xfff0);
    #else
    _ext_header.frag_seq = (new_frag_num << 8) | (_ext_header.frag_seq & 0xf0ff);
    #endif
}

void Dot11Data::seq_num(small_uint<12> new_seq_num) {
    #if TINS_IS_LITTLE_ENDIAN
    _ext_header.frag_seq = (new_seq_num << 4) | (_ext_header.frag_seq & 0xf);
    #else
    _ext_header.frag_seq = Endian::host_to_le<uint16_t>(new_seq_num << 4) | (_ext_header.frag_seq & 0xf00);
    #endif
}

void Dot11Data::addr4(const address_type &new_addr4) {
    _addr4 = new_addr4;
}

uint32_t Dot11Data::write_ext_header(uint8_t *buffer, uint32_t total_sz) {
    uint32_t written = sizeof(_ext_header);
    memcpy(buffer, &_ext_header, sizeof(_ext_header));
    buffer += sizeof(_ext_header);
    if (from_ds() && to_ds()) {
        written += _addr4.size();
        _addr4.copy(buffer);
    }
    return written;

}

/* QoS data. */

Dot11QoSData::Dot11QoSData(const address_type &dst_hw_addr, 
  const address_type &src_hw_addr) 
: Dot11Data(dst_hw_addr, src_hw_addr) 
{
    subtype(Dot11::QOS_DATA_DATA);
    _qos_control = 0;
}

Dot11QoSData::Dot11QoSData(const uint8_t *buffer, uint32_t total_sz) 
// Am I breaking something? :S
: Dot11Data(buffer, total_sz, no_inner_pdu()) {
    uint32_t sz = data_frame_size();
    buffer += sz;
    total_sz -= sz;
    if(total_sz < sizeof(_qos_control))
        throw malformed_packet();
    _qos_control = *(uint16_t*)buffer;
    total_sz -= sizeof(uint16_t);
    buffer += sizeof(uint16_t);
    if(total_sz) {
        // If the wep bit is on, then just use a RawPDU
        if(wep())
            inner_pdu(new Tins::RawPDU(buffer, total_sz));
        else
            inner_pdu(new Tins::SNAP(buffer, total_sz));
    }
}

void Dot11QoSData::qos_control(uint16_t new_qos_control) {
    this->_qos_control = Endian::host_to_le(new_qos_control);
}

uint32_t Dot11QoSData::header_size() const {
    return Dot11Data::header_size() + sizeof(this->_qos_control);
}

uint32_t Dot11QoSData::write_fixed_parameters(uint8_t *buffer, uint32_t total_sz) {
    uint32_t sz = sizeof(this->_qos_control);
    #ifdef TINS_DEBUG
    assert(sz <= total_sz);
    #endif
    *(uint16_t*)buffer = this->_qos_control;
    return sz;
}
} // namespace Tins

#endif // HAVE_DOT11