class Poco::Net::ICMPPacketImpl

Overview

This is the abstract class for ICMP packet implementations. More…

#include <ICMPPacketImpl.h>

class ICMPPacketImpl
{
public:
    // fields

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

    // construction

    ICMPPacketImpl(int dataSize = 48);

    // 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
        );
};

// direct descendants

class ICMPv4PacketImpl;

Detailed Documentation

This is the abstract class for ICMP packet implementations.

Construction

ICMPPacketImpl(int dataSize = 48)

Constructor. Creates an ICMPPacketImpl.

Methods

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

Returns raw ICMP packet.

ICMP header and data are included in the packet. If init is true, initPacket() is called.

virtual
int
packetSize() const = 0

Returns the total size of packet (ICMP header + data) in number of octets.

Must be overriden.

virtual
int
maxPacketSize() const

Returns the maximum permitted size of packet in number of octets.

Poco::UInt16
sequence() const

Returns the most recent sequence number generated.

void
setDataSize(int dataSize)

Sets data size.

int
getDataSize() const

Returns data size.

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

Returns current epoch time if either argument is equal to zero.

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

Supplied buffer includes IP header, ICMP header and data. Must be overriden.

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

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

equals the process id).

Supplied buffer includes IP header, ICMP header and data. Must be overriden.

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

Returns error description string.

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

Supplied buffer includes IP header, ICMP header and data. Must be overriden.

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

Returns the description of the packet type.

Must be overriden.

Poco::UInt16
nextSequence()

Increments sequence number and returns the new value.

void
resetSequence()

Resets the sequence to zero.

virtual
void
initPacket() = 0

(Re)assembles the packet.

Must be overriden.

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

Calculates the checksum for supplied buffer.