class Poco::Net::ICMPv4PacketImpl

Overview

This class implements the ICMPv4 packet. More…

#include <ICMPv4PacketImpl.h>

class ICMPv4PacketImpl: public Poco::Net::ICMPPacketImpl
{
public:
    // enums

    enum DestinationUnreachableCode;
    enum MessageType;
    enum ParameterProblemCode;
    enum RedirectMessageCode;
    enum TimeExceededCode;

    // structs

    struct Header;

    // fields

    static const Poco::UInt16 MAX_PACKET_SIZE;
    static const std::string MESSAGE_TYPE[MESSAGE_TYPE_LENGTH];
    static const Poco::UInt8 DESTINATION_UNREACHABLE_TYPE;
    static const Poco::UInt8 SOURCE_QUENCH_TYPE;
    static const Poco::UInt8 REDIRECT_MESSAGE_TYPE;
    static const Poco::UInt8 TIME_EXCEEDED_TYPE;
    static const Poco::UInt8 PARAMETER_PROBLEM_TYPE;

    // construction

    ICMPv4PacketImpl(int dataSize = 48);

    // methods

    poco_static_assert(offsetof(Header, code) = =0x01);
    poco_static_assert(offsetof(Header, checksum) = =0x02);
    poco_static_assert(offsetof(Header, id) = =0x04);
    poco_static_assert(offsetof(Header, seq) = =0x06);

    virtual
    int
    packetSize() const;

    virtual
    struct timeval
    time(
        Poco::UInt8* buffer = 0,
        int length = 0
        ) const;

    bool
    validReplyID(
        Poco::UInt8* buffer,
        int length
        ) const;

    virtual
    std::string
    errorDescription(
        Poco::UInt8* buffer,
        int length
        );

    virtual
    std::string
    typeDescription(int typeId);
};

Inherited Members

public:
    // fields

    static const Poco::UInt16 MAX_PACKET_SIZE;
    static const Poco::UInt16 MAX_SEQ_VALUE;

    // methods

    const Poco::UInt8*
    packet(bool init = true);

    virtual
    int
    packetSize() const = 0;

    virtual
    int
    maxPacketSize() const;

    Poco::UInt16
    sequence() const;

    void
    setDataSize(int dataSize);

    int
    getDataSize() const;

    virtual
    struct timeval
    time(
        Poco::UInt8* buffer = 0,
        int length = 0
        ) const = 0;

    virtual
    bool
    validReplyID(
        unsigned char* buffer,
        int length
        ) const = 0;

    virtual
    std::string
    errorDescription(
        Poco::UInt8* buffer,
        int length
        ) = 0;

    virtual
    std::string
    typeDescription(int typeId) = 0;

protected:
    // methods

    Poco::UInt16
    nextSequence();

    void
    resetSequence();

    virtual
    void
    initPacket() = 0;

    Poco::UInt16
    checksum(
        Poco::UInt16* addr,
        Poco::Int32 len
        );

Detailed Documentation

This class implements the ICMPv4 packet.

Parts are based on original ICMP code by Mike Muuss U. S. Army Ballistic Research Laboratory December, 1983

Construction

ICMPv4PacketImpl(int dataSize = 48)

Constructor. Creates an ICMPv4PacketImpl.

Methods

virtual
int
packetSize() const

Returns the total length of packet (header + data);.

virtual
struct timeval
time(
    Poco::UInt8* buffer = 0,
    int length = 0
    ) const

Returns current epoch time if either buffer or length are equal to zero.

Otherwise, it extracts the time value from the supplied buffer.

Buffer includes IP header, ICMP header and data.

bool
validReplyID(
    Poco::UInt8* buffer,
    int length
    ) const

Returns true if the extracted id is recognized (i.e.

equals the process id).

Buffer includes IP header, ICMP header and data.

virtual
std::string
errorDescription(
    Poco::UInt8* buffer,
    int length
    )

Returns error description string.

If supplied buffer contains ICMPv4 echo reply packet, an empty string is returned indicating the absence of error.

Buffer includes IP header, ICMP header and data.

virtual
std::string
typeDescription(int typeId)

Returns the description of the packet type.