libtins/src/dot3.cpp

/*
 * Copyright (c) 2017, 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 <cstring>
#include "macros.h"
#ifndef _WIN32
    #if defined(BSD) || defined(__FreeBSD_kernel__)
        #include <net/if_dl.h>
    #else
        #include <netpacket/packet.h>
    #endif
    #include <net/ethernet.h>
    #include <netinet/in.h>
#endif
#include "dot3.h"
#include "packet_sender.h"
#include "llc.h"
#include "exceptions.h"
#include "memory_helpers.h"

using std::copy;
using std::equal;

using Tins::Memory::InputMemoryStream;
using Tins::Memory::OutputMemoryStream;

namespace Tins {

const Dot3::address_type Dot3::BROADCAST("ff:ff:ff:ff:ff:ff");

PDU::metadata Dot3::extract_metadata(const uint8_t* /*buffer*/, uint32_t total_sz) {
    if (TINS_UNLIKELY(total_sz < sizeof(dot3_header))) {
        throw malformed_packet();
    }
    return metadata(sizeof(dot3_header), pdu_flag, PDU::UNKNOWN);
}

Dot3::Dot3(const address_type& dst_hw_addr, const address_type& src_hw_addr)
: header_() {
    this->dst_addr(dst_hw_addr);
    this->src_addr(src_hw_addr);
}

Dot3::Dot3(const uint8_t* buffer, uint32_t total_sz) {
    InputMemoryStream stream(buffer, total_sz);
    stream.read(header_);
    if (stream) {
        inner_pdu(new Tins::LLC(stream.pointer(), stream.size()));
    }
}

void Dot3::dst_addr(const address_type& address) {
    address.copy(header_.dst_mac);
}

void Dot3::src_addr(const address_type& address) {
    address.copy(header_.src_mac);
}

void Dot3::length(uint16_t value) {
    header_.length = Endian::host_to_be(value);
}

uint32_t Dot3::header_size() const {
    return sizeof(header_);
}

#if !defined(_WIN32) || defined(TINS_HAVE_PACKET_SENDER_PCAP_SENDPACKET)
void Dot3::send(PacketSender& sender, const NetworkInterface& iface) {
    if (!iface) {
        throw invalid_interface();
    }
        
    #if defined(BSD) || defined(__FreeBSD_kernel__) || defined(TINS_HAVE_PACKET_SENDER_PCAP_SENDPACKET)
        sender.send_l2(*this, 0, 0, iface);
    #else
        struct sockaddr_ll addr;

        memset(&addr, 0, sizeof(struct sockaddr_ll));

        addr.sll_family = Endian::host_to_be<uint16_t>(PF_PACKET);
        addr.sll_protocol = Endian::host_to_be<uint16_t>(ETH_P_ALL);
        addr.sll_halen = address_type::address_size;
        addr.sll_ifindex = iface.id();
        memcpy(&(addr.sll_addr), header_.dst_mac, sizeof(header_.dst_mac));

        sender.send_l2(*this, (struct sockaddr*)&addr, (uint32_t)sizeof(addr), iface);
    #endif
}
#endif // !_WIN32 || TINS_HAVE_PACKET_SENDER_PCAP_SENDPACKET

bool Dot3::matches_response(const uint8_t* ptr, uint32_t total_sz) const {
    if (total_sz < sizeof(header_)) {
        return false;
    }
    const dot3_header* eth_ptr = (const dot3_header*)ptr;
    if (address_type(header_.src_mac) == address_type(eth_ptr->dst_mac)) {
        if (address_type(header_.src_mac) == address_type(eth_ptr->dst_mac) || 
            dst_addr() == BROADCAST) {
            ptr += sizeof(dot3_header);
            total_sz -= sizeof(dot3_header);
            return inner_pdu() ? inner_pdu()->matches_response(ptr, total_sz) : true;
        }
    }
    return false;
}

void Dot3::write_serialization(uint8_t* buffer, uint32_t total_sz) {
    OutputMemoryStream stream(buffer, total_sz);
    header_.length = Endian::host_to_be<uint16_t>(size() - sizeof(header_));
    stream.write(header_);
}

#ifndef _WIN32
PDU* Dot3::recv_response(PacketSender& sender, const NetworkInterface& iface) {
    if (!iface) {
        throw invalid_interface();
    }
    #if !defined(BSD) && !defined(__FreeBSD_kernel__)
        struct sockaddr_ll addr;
        memset(&addr, 0, sizeof(struct sockaddr_ll));

        addr.sll_family = Endian::host_to_be<uint16_t>(PF_PACKET);
        addr.sll_protocol = Endian::host_to_be<uint16_t>(ETH_P_802_3);
        addr.sll_halen = address_type::address_size;
        addr.sll_ifindex = iface.id();
        memcpy(&(addr.sll_addr), header_.dst_mac, sizeof(header_.dst_mac));

        return sender.recv_l2(*this, (struct sockaddr*)&addr, (uint32_t)sizeof(addr));
    #else
        return sender.recv_l2(*this, 0, 0, iface);
    #endif
}

#endif // _WIN32

} // Tins