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// Copyright (C) 2012-2014 Internet Systems Consortium, Inc. ("ISC")
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
// AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
// PERFORMANCE OF THIS SOFTWARE.
#ifndef PERF_PKT4_H
#define PERF_PKT4_H
#include <time.h>
#include <boost/shared_ptr.hpp>
#include <dhcp/pkt4.h>
#include "localized_option.h"
#include "pkt_transform.h"
namespace isc {
namespace perfdhcp {
/// \brief PerfPkt4 (DHCPv4 packet)
///
/// This class extends the functionality of \ref isc::dhcp::Pkt4 by adding the
/// ability to specify an options offset in the DHCP message and to override
/// options' contents. This is particularly useful when we create a packet
/// object using a template file (i.e. do not build it dynamically). The client
/// class should read data from the template file and pass it to this class in
/// a buffer.
///
/// The contents of such a packet can be later partially replaced, notably the
/// selected options and the transaction ID. (The transaction ID and its
/// offset in the template file are passed via the constructor.)
///
/// In order to replace contents of the options, the client class has to
/// create a collection of \ref LocalizedOption, adding them using
/// \ref dhcp::Pkt4::addOption.
///
/// \note If you don't use template files simply use constructors
/// inherited from parent class and isc::dhcp::Option type instead
class PerfPkt4 : public dhcp::Pkt4 {
public:
/// Localized option pointer type.
typedef boost::shared_ptr<LocalizedOption> LocalizedOptionPtr;
/// \brief Constructor, used to create messages from packet
/// template files.
///
/// Creates a new DHCPv4 message using the provided buffer.
/// The transaction ID and its offset are specified via this
/// constructor. The transaction ID is stored in outgoing message
/// when client class calls \ref PerfPkt4::rawPack. Transaction id
/// offset value is used for incoming and outgoing messages to
/// identify transaction ID field's position in incoming and outgoing
/// messages.
///
/// \param buf buffer holding contents of the message (this can
/// be directly read from template file).
/// \param len length of the data in the buffer.
/// \param transid_offset transaction id offset in a message.
/// \param transid transaction id to be stored in outgoing message.
PerfPkt4(const uint8_t* buf,
size_t len,
size_t transid_offset = 1,
uint32_t transid = 0);
/// \brief Returns transaction id offset in packet buffer
///
/// \return Transaction ID offset in packet buffer
size_t getTransidOffset() const { return transid_offset_; };
/// \brief Prepares on-wire format from raw buffer.
///
/// The method copies the buffer provided in the constructor to the
/// output buffer and replaces the transaction ID and selected
/// options with new data.
///
/// \note Use this method to prepare an on-wire DHCPv4 message
/// when you use template packets that require replacement
/// of selected options' contents before sending.
///
/// \return false ID pack operation failed.
bool rawPack();
/// \brief Handles limited binary packet parsing for packets with
/// custom offsets of options and transaction ID
///
/// This method handles the parsing of packets that have custom offsets
/// of options or transaction ID. Use
/// \ref isc::dhcp::Pkt4::addOption to specify which options to parse.
/// Options should be of the \ref isc::perfdhcp::LocalizedOption
/// type with offset values provided. Each added option will
/// be updated with actual data read from the binary packet buffer.
///
/// \return false If unpack operation failed.
bool rawUnpack();
/// \brief Replace contents of buffer with data.
///
/// Function replaces part of the buffer with data from vector.
///
/// \param dest_pos position in buffer where data is replaced.
/// \param first beginning of data range in source vector.
/// \param last end of data range in source vector.
void writeAt(size_t dest_pos,
std::vector<uint8_t>::iterator first,
std::vector<uint8_t>::iterator last);
/// \brief Replace contents of buffer with value.
///
/// Function replaces part of buffer with value.
///
/// \param dest_pos position in buffer where value is
/// to be written.
/// \param val value to be written.
template<typename T>
void writeValueAt(size_t dest_pos, T val) {
PktTransform::writeValueAt<T>(data_, dest_pos, val);
}
private:
size_t transid_offset_; ///< transaction id offset
};
typedef boost::shared_ptr<PerfPkt4> PerfPkt4Ptr;
} // namespace perfdhcp
} // namespace isc
#endif // PERF_PKT4_H
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