todump.hh

COPE the first practical network coding scheme which is developped on click

// -*- mode: c++; c-basic-offset: 4 -*-
#ifndef CLICK_TODUMP_HH
#define CLICK_TODUMP_HH
#include <click/timer.hh>
#include <click/element.hh>
#include <click/task.hh>
#include <click/notifier.hh>
#include <stdio.h>
CLICK_DECLS

/*
=c

ToDump(FILENAME [, I<keywords> SNAPLEN, ENCAP, USE_ENCAP_FROM, EXTRA_LENGTH])

=s analysis

writes packets to a tcpdump(1) file

=d

Writes incoming packets to FILENAME in `tcpdump -w' format. This file can be
read by `tcpdump -r', or by FromDump on a later run. FILENAME can be `-', in
which case ToDump writes to the standard output.

Writes at most SNAPLEN bytes of each packet to the file. The default SNAPLEN
is 2000. If SNAPLEN is 0, the whole packet will be written to the file.  ENCAP
specifies the first header each packet is expected to have.  This information
is stored in the file header, and must be correct or tcpdump won't be able to
read the file correctly. It can be C<ETHER> (Ethernet encapsulation),
C<IP> (raw IP packets), C<FDDI>, C<ATM>, C<802_11>, C<SLL>, C<AIRONET>, C<HDLC>,
C<PPP_HDLC>, C<PPP>, C<SUNATM>, C<PRISM>, or C<NULL>; the default is C<ETHER>.

ToDump may have zero or one output. If it has an output, then it emits all
received packets on that output. ToDump will schedule itself on the task list
if it is used as a pull element with no outputs.

Keyword arguments are:

=over 8

=item SNAPLEN

Integer.  See above.

=item ENCAP

The encapsulation type to store in the dump.  See above.

=item USE_ENCAP_FROM

Argument is a space-separated list of element names. At initialization time,
ToDump will check these elements' `encap' handlers, and parse them as ENCAP
arguments. If all the handlers agree, ToDump will use that encapsulation type;
otherwise, it will report an error. You can specify at most one of ENCAP and
USE_ENCAP_FROM. FromDump and FromDevice.u have `encap' handlers.

=item EXTRA_LENGTH

Boolean. Set to true if you want ToDump to store any extra length as recorded
in packets' extra length annotations. Default is true.

=back

This element is only available at user level.

=n

ToDump stores packets' true length annotations when available.

=h filename read-only

Returns the filename.

=a

FromDump, FromDevice.u, ToDevice.u, tcpdump(1) */

class ToDump : public Element { public:
  
    ToDump();
    ~ToDump();

    const char *class_name() const	{ return "ToDump"; }
    const char *processing() const	{ return AGNOSTIC; }
    const char *flags() const		{ return "S2"; }

    // configure after FromDevice and FromDump
    void notify_noutputs(int);
    int configure_phase() const		{ return CONFIGURE_PHASE_DEFAULT+100; }
    int configure(Vector<String> &, ErrorHandler *);
    int initialize(ErrorHandler *);
    void cleanup(CleanupStage);
    void add_handlers();
    ToDump *hotswap_element() const;
    void take_state(Element *, ErrorHandler *);

    void push(int, Packet *);
    Packet *pull(int);
    bool run_task();

  private:

    String _filename;
    FILE *_fp;
    unsigned _snaplen;
    int _linktype;
    bool _active;
    bool _extra_length;
    Task _task;
    NotifierSignal _signal;
    Element **_use_encap_from;

    static String read_handler(Element *, void *);
    void write_packet(Packet *);

};

CLICK_ENDDECLS
#endif