inet::PcapDump Class Reference

Dumps packets into a PCAP file; see the "pcap-savefile" man page or http://www.tcpdump.org/ for details on the file format. More...

#include <PcapDump.h>

Public Member Functions
	PcapDump ()
	Constructor. More...
	~PcapDump ()
	Destructor. More...
void	openPcap (const char *filename, unsigned int snaplen)
	Opens a PCAP file with the given file name. More...
bool	isOpen () const
	Returns true if the pcap file is currently open. More...
void	writeFrame (simtime_t time, const IPv4Datagram *ipPacket)
	Records the given packet into the output file if it is open, and throws an exception otherwise. More...
void	writeIPv6Frame (simtime_t stime, const IPv6Datagram *ipPacket)
void	closePcap ()
	Closes the output file if it is open. More...
void	setFlushParameter (bool doFlush)
	Force flushing of pcap dump. More...

Protected Attributes
FILE *	dumpfile = nullptr
unsigned int	snaplen = 0
bool	flush = false

Detailed Description

Dumps packets into a PCAP file; see the "pcap-savefile" man page or http://www.tcpdump.org/ for details on the file format.

Note: The file is currently recorded in the "classic" format, not in the "Next Generation" file format also on tcpdump.org.

Constructor & Destructor Documentation

inet::PcapDump::PcapDump ( )

inline

Constructor.

It does not open the output file.

{}

inet::PcapDump::~PcapDump

(

)

Destructor.

It closes the output file if it is open.

{
    closePcap();
}

Member Function Documentation

void inet::PcapDump::closePcap

(

)

Closes the output file if it is open.

Referenced by inet::TCPDump::finish(), and inet::PcapRecorder::finish().

{
    if (dumpfile) {
        fclose(dumpfile);
        dumpfile = nullptr;
    }
}

bool inet::PcapDump::isOpen ( ) const

inline

Returns true if the pcap file is currently open.

Referenced by inet::TCPDump::handleMessage(), and inet::PcapRecorder::recordPacket().

{ return dumpfile != nullptr; }

void inet::PcapDump::openPcap	(	const char *	filename,
		unsigned int	snaplen
	)

Opens a PCAP file with the given file name.

The snaplen parameter is the length that packets will be truncated to. Throws an exception if the file cannot be opened.

Referenced by inet::TCPDump::initialize(), and inet::PcapRecorder::initialize().

{
    struct pcap_hdr fh;

    if (!filename || !filename[0])
        throw cRuntimeError("Cannot open pcap file: file name is empty");

    dumpfile = fopen(filename, "wb");

    if (!dumpfile)
        throw cRuntimeError("Cannot open pcap file [%s] for writing: %s", filename, strerror(errno));

    snaplen = snaplen_par;

    flush = false;

    fh.magic = PCAP_MAGIC;
    fh.version_major = 2;
    fh.version_minor = 4;
    fh.thiszone = 0;
    fh.sigfigs = 0;
    fh.snaplen = snaplen;
    fh.network = 0;
    fwrite(&fh, sizeof(fh), 1, dumpfile);
}

void inet::PcapDump::setFlushParameter ( bool  doFlush )

inline

Force flushing of pcap dump.

Referenced by inet::PcapRecorder::initialize().

{ flush = doFlush; };

void inet::PcapDump::writeFrame	(	simtime_t	time,
		const IPv4Datagram *	ipPacket
	)

Records the given packet into the output file if it is open, and throws an exception otherwise.

Referenced by inet::TCPDump::handleMessage(), and inet::PcapRecorder::recordPacket().

{
    if (!dumpfile)
        throw cRuntimeError("Cannot write frame: pcap output file is not open");

#ifdef WITH_IPv4
    uint8 buf[MAXBUFLENGTH];
    memset((void *)&buf, 0, sizeof(buf));

    struct pcaprec_hdr ph;
    ph.ts_sec = (int32)stime.inUnit(SIMTIME_S);
    ph.ts_usec = (uint32)(stime.inUnit(SIMTIME_US) - (uint32)1000000 * stime.inUnit(SIMTIME_S));
    // Write Ethernet header
    uint32 hdr = 2;    //AF_INET

    serializer::Buffer b(buf, sizeof(buf));
    serializer::Context c;
    c.throwOnSerializerNotFound = false;
    serializer::IPv4Serializer().serializePacket(ipPacket, b, c);
    int32 serialized_ip = b.getPos();

    ph.orig_len = serialized_ip + sizeof(uint32);

    ph.incl_len = ph.orig_len > snaplen ? snaplen : ph.orig_len;
    fwrite(&ph, sizeof(ph), 1, dumpfile);
    fwrite(&hdr, sizeof(uint32), 1, dumpfile);
    fwrite(buf, ph.incl_len - sizeof(uint32), 1, dumpfile);
    if (flush)
        fflush(dumpfile);
#else // ifdef WITH_IPv4
    throw cRuntimeError("Cannot write frame: INET compiled without IPv4 feature");
#endif // ifdef WITH_IPv4
}

void inet::PcapDump::writeIPv6Frame	(	simtime_t	stime,
		const IPv6Datagram *	ipPacket
	)

Referenced by inet::PcapRecorder::recordPacket().

{
    if (!dumpfile)
        throw cRuntimeError("Cannot write frame: pcap output file is not open");

#ifdef WITH_IPv6
    uint8 buf[MAXBUFLENGTH];
    memset((void *)&buf, 0, sizeof(buf));

    struct pcaprec_hdr ph;
    ph.ts_sec = (int32)stime.inUnit(SIMTIME_S);
    ph.ts_usec = (uint32)(stime.inUnit(SIMTIME_US) - (uint32)1000000 * stime.inUnit(SIMTIME_S));
    // Write Ethernet header
    uint32 hdr = 2;    //AF_INET

    serializer::Buffer b(buf, sizeof(buf));
    serializer::Context c;
    c.throwOnSerializerNotFound = false;
    serializer::IPv6Serializer().serializePacket(ipPacket, b, c);
    int32 serialized_ip = b.getPos();

    if (serialized_ip > 0) {
        ph.orig_len = serialized_ip + sizeof(uint32);

        ph.incl_len = ph.orig_len > snaplen ? snaplen : ph.orig_len;
        fwrite(&ph, sizeof(ph), 1, dumpfile);
        fwrite(&hdr, sizeof(uint32), 1, dumpfile);
        fwrite(buf, ph.incl_len - sizeof(uint32), 1, dumpfile);
        if (flush)
            fflush(dumpfile);
    }
#else // ifdef WITH_IPv6
    throw cRuntimeError("Cannot write frame: INET compiled without IPv6 feature");
#endif // ifdef WITH_IPv6
}

Member Data Documentation

FILE* inet::PcapDump::dumpfile = nullptr

protected

bool inet::PcapDump::flush = false

protected

unsigned int inet::PcapDump::snaplen = 0

protected

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The documentation for this class was generated from the following files:

• PcapDump.h
• PcapDump.cc