libtins/include/tins/rawpdu.h

/*
 * 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.
 *
 */

#ifndef TINS_RAWPDU_H
#define TINS_RAWPDU_H

#include <vector>
#include <string>
#include "pdu.h"
#include "macros.h"
#include "cxxstd.h"

namespace Tins {

/** 
 * \class PDU
 * \brief Represents a PDU which holds raw data.
 *
 * This class is a wrapper over a byte array. It can be used to hold
 * the payload sent over transport layer protocols (such as TCP or UDP).
 *
 * While sniffing, this class is the one that will hold transport layer
 * protocols' payload. You can simply convert a RawPDU into a specific
 * application layer protocol using the RawPDU::to method:
 *
 * \code
 * // Get a RawPDU from somewhere
 * RawPDU raw = get_raw_pdu();
 *
 * // Parse it as a DHCP PDU.
 * DHCP dhcp = raw.to<DHCP>();
 *
 * // Or parse it as DNS. Of course this will fail if the contents
 * // don't look like DNS
 * DNS dns = raw.to<DNS>();
 * \endcode
 */
class TINS_API RawPDU : public PDU {
public:
    /**
     * The type used to store the payload.
     */
    typedef std::vector<uint8_t> payload_type;
    
    /**
     * This PDU's flag.
     */
    static const PDU::PDUType pdu_flag = PDU::RAW;

    /** 
     * \brief Creates an instance of RawPDU.
     *
     * The payload is copied, therefore the original payload's memory
     * must be freed by the user.
     * \param pload The payload which the RawPDU will contain.
     * \param size The size of the payload.
     */
    RawPDU(const uint8_t* pload, uint32_t size);
    
    /**
     * \brief Constructs a RawPDU from an iterator range.
     *
     * The data in the iterator range is copied into the RawPDU
     * internal buffer.
     *
     * \param start The beginning of the iterator range.
     * \param end The end of the iterator range.
     */
    template<typename ForwardIterator>
    RawPDU(ForwardIterator start, ForwardIterator end) 
    : payload_(start, end) { }

    #if TINS_IS_CXX11
        /** 
         * \brief Creates an instance of RawPDU from a payload_type.
         *
         * The payload is moved into the RawPDU's internal buffer.
         * 
         * \param data The payload to use.
         */
        RawPDU(payload_type&& data)
        : payload_(move(data)) { }
    #endif // TINS_IS_CXX11

    /** 
     * \brief Creates an instance of RawPDU from an input string.
     * 
     * \param data The content of the payload.
     */
    RawPDU(const std::string& data);

    /**
     * \brief Setter for the payload field
     * \param pload The payload to be set.
     */
    void payload(const payload_type& pload);

    /**
     * \brief Setter for the payload field
     * \param start The start of the new payload.
     * \param end The end of the new payload.
     */
    template<typename ForwardIterator>
    void payload(ForwardIterator start, ForwardIterator end) {
        payload_.assign(start, end);
    }

    /** 
     * \brief Const getter for the payload.
     * \return The RawPDU's payload.
     */
    const payload_type& payload() const {
        return payload_;
    }
    
    /** 
     * \brief Non-const getter for the payload.
     * \return The RawPDU's payload.
     */
    payload_type& payload() {
        return payload_;
    }
    
    /** 
     * \brief Returns the header size.
     * 
     * This returns the same as RawPDU::payload_size().
     *
     * This metod overrides PDU::header_size. \sa PDU::header_size
     */
    uint32_t header_size() const;
    
    /** 
     * \brief Returns the payload size.
     *
     * \return uint32_t containing the payload size.
     */
    uint32_t payload_size() const {
        return static_cast<uint32_t>(payload_.size());
    }

    /**
     * \brief Check wether ptr points to a valid response for this PDU.
     *
     * This always returns true, since we don't know what this 
     * RawPDU is holding.
     * 
     * \sa PDU::matches_response
     * \param ptr The pointer to the buffer.
     * \param total_sz The size of the buffer.
     */
    bool matches_response(const uint8_t* ptr, uint32_t total_sz) const;

    /**
     * \brief Getter for the PDU's type.
     * \sa PDU::pdu_type
     */
    PDUType pdu_type() const {
        return pdu_flag;
    }
    
    /**
     * \brief Constructs the given PDU type from the raw data stored
     * in this RawPDU.
     */
    template<typename T>
    T to() const {
        return T(&payload_[0], static_cast<uint32_t>(payload_.size()));
    }
    
    /**
     * \sa PDU::clone
     */
    RawPDU* clone() const {
        return new RawPDU(*this);
    }
private:
    void write_serialization(uint8_t* buffer, uint32_t total_sz, const PDU* parent);

    payload_type payload_;
};

} // Tins

#endif // TINS_RAWPDU_H