Provided by: libnet-pcap-perl_0.21-1_amd64 bug

NAME

       Net::Pcap - Interface to the pcap(3) LBL packet capture library

VERSION

       Version 0.21

SYNOPSIS

           use Net::Pcap;

           my $err = '';
           my $dev = pcap_lookupdev(\$err);  # find a device

           # open the device for live listening
           my $pcap = pcap_open_live($dev, 1024, 1, 0, \$err);

           # loop over next 10 packets
           pcap_loop($pcap, 10, \&process_packet, "just for the demo");

           # close the device
           pcap_close($pcap);

           sub process_packet {
               my ($user_data, $header, $packet) = @_;
               # do something ...
           }

DESCRIPTION

       "Net::Pcap" is a Perl binding to the LBL pcap(3) library and its Win32 counterpart, the
       WinPcap library. Pcap (packet capture) is a portable API to capture network packet: it
       allows applications to capture packets at link-layer, bypassing the normal protocol stack.
       It also provides features like kernel-level packet filtering and access to internal
       statistics.

       Common applications include network statistics collection, security monitoring, network
       debugging, etc.

NOTES

   Signals handling
       Since version 5.7.3, Perl uses a mechanism called "deferred signals" to delay signals
       delivery until "safe" points in the interpreter.  See "Deferred Signals (Safe Signals)" in
       perlipc for a detailed explanation.

       Since "Net::Pcap" version 0.08, released in October 2005, the module modified the internal
       variable "PL_signals" to re-enable immediate signals delivery in Perl 5.8 and later within
       some XS functions (CPAN-RT #6320). However, it can create situations where the Perl
       interpreter is less stable and can crash (CPAN-RT #43308). Therefore, as of version 0.17,
       "Net::Pcap" no longer modifies "PL_signals" by itself, but provides facilities so the user
       has full control of how signals are delivered.

       First, the "pcap_perl_settings()" function allows one to select how signals are handled:

           pcap_perl_settings(PERL_SIGNALS_UNSAFE);
           pcap_loop($pcap, 10, \&process_packet, "");
           pcap_perl_settings(PERL_SIGNALS_SAFE);

       Then, to easily make code interruptable, "Net::Pcap" provides the "UNSAFE_SIGNALS" pseudo-
       bloc:

           UNSAFE_SIGNALS {
               pcap_loop($pcap, 10, \&process_packet, "");
           };

       (Stolen from Rafael Garcia-Suarez's "Perl::Unsafe::Signals")

EXPORTS

       "Net::Pcap" supports the following "Exporter" tags:

       •   ":bpf" exports a few BPF related constants:

               BPF_ALIGNMENT  BPF_MAJOR_VERSION  BPF_MAXBUFSIZE  BPF_MAXINSNS
               BPF_MEMWORDS  BPF_MINBUFSIZE  BPF_MINOR_VERSION  BPF_RELEASE

       •   ":datalink" exports the data link types macros:

               DLT_AIRONET_HEADER  DLT_APPLE_IP_OVER_IEEE1394  DLT_ARCNET
               DLT_ARCNET_LINUX  DLT_ATM_CLIP  DLT_ATM_RFC1483  DLT_AURORA
               DLT_AX25  DLT_CHAOS  DLT_CHDLC  DLT_CISCO_IOS  DLT_C_HDLC
               DLT_DOCSIS  DLT_ECONET  DLT_EN10MB  DLT_EN3MB  DLT_ENC  DLT_FDDI
               DLT_FRELAY  DLT_HHDLC  DLT_IBM_SN  DLT_IBM_SP  DLT_IEEE802
               DLT_IEEE802_11  DLT_IEEE802_11_RADIO DLT_IEEE802_11_RADIO_AVS
               DLT_IPFILTER  DLT_IP_OVER_FC  DLT_JUNIPER_ATM1 DLT_JUNIPER_ATM2
               DLT_JUNIPER_ES  DLT_JUNIPER_GGSN  DLT_JUNIPER_MFR DLT_JUNIPER_MLFR
               DLT_JUNIPER_MLPPP  DLT_JUNIPER_MONITOR  DLT_JUNIPER_SERVICES
               DLT_LINUX_IRDA  DLT_LINUX_SLL  DLT_LOOP  DLT_LTALK  DLT_NULL
               DLT_OLD_PFLOG  DLT_PCI_EXP  DLT_PFLOG  DLT_PFSYNC  DLT_PPP
               DLT_PPP_BSDOS  DLT_PPP_ETHER  DLT_PPP_SERIAL  DLT_PRISM_HEADER
               DLT_PRONET  DLT_RAW  DLT_RIO  DLT_SLIP  DLT_SLIP_BSDOS  DLT_SUNATM
               DLT_SYMANTEC_FIREWALL  DLT_TZSP  DLT_USER0  DLT_USER1  DLT_USER2
               DLT_USER3  DLT_USER4  DLT_USER5  DLT_USER6  DLT_USER7  DLT_USER8
               DLT_USER9  DLT_USER10  DLT_USER11  DLT_USER12  DLT_USER13
               DLT_USER14  DLT_USER15

       •   ":pcap" exports the following "pcap" constants:

               PCAP_ERRBUF_SIZE    PCAP_IF_LOOPBACK
               PCAP_VERSION_MAJOR  PCAP_VERSION_MINOR

       •   ":mode" exports the following constants:

               MODE_CAPT  MODE_MON  MODE_STAT

       •   ":openflag" exports the following constants:

               OPENFLAG_PROMISCUOUS  OPENFLAG_DATATX_UDP  OPENFLAG_NOCAPTURE_RPCAP

       •   ":source" exports the following constants:

               PCAP_SRC_FILE  PCAP_SRC_IFLOCAL  PCAP_SRC_IFREMOTE

       •   ":sample" exports the following constants:

               PCAP_SAMP_NOSAMP  PCAP_SAMP_1_EVERY_N  PCAP_SAMP_FIRST_AFTER_N_MS

       •   ":rpcap" exports the following constants:

               RMTAUTH_NULL  RMTAUTH_PWD

       •   ":functions" short names of the functions (without the "pcap_" prefix) for those which
           would not cause a clash with an already defined name.  Namely, the following functions
           are not available in short form: "open()", "close()", "next()", "dump()", "file()",
           "fileno()".  Using these short names is now discouraged, and may be removed in the
           future.

       By default, this module exports the symbols from the ":datalink" and ":pcap" tags, and all
       the functions, with the same names as the C library.

FUNCTIONS

       All functions defined by "Net::Pcap" are direct mappings to the libpcap functions.
       Consult the pcap(3) documentation and source code for more information.

       Arguments that change a parameter, for example "pcap_lookupdev()", are passed that
       parameter as a reference.  This is to retain compatibility with previous versions of
       "Net::Pcap".

   Lookup functions
       pcap_lookupdev(\$err)
           Returns the name of a network device that can be used with "pcap_open_live()"
           function.  On error, the $err parameter is filled with an appropriate error message
           else it is undefined.

           Example

               $dev = pcap_lookupdev();

       pcap_findalldevs(\%devinfo, \$err)
           Returns a list of all network device names that can be used with "pcap_open_live()"
           function.  On error, the $err parameter is filled with an appropriate error message
           else it is undefined.

           Example

               @devs = pcap_findalldevs(\%devinfo, \$err);
               for my $dev (@devs) {
                   print "$dev : $devinfo{$dev}\n"
               }

           Note
               For backward compatibility reasons, this function can also be called using the
               following signatures:

                   @devs = pcap_findalldevs(\$err);

                   @devs = pcap_findalldevs(\$err, \%devinfo);

               The first form was introduced by Marco Carnut in "Net::Pcap" version 0.05 and kept
               intact in versions 0.06 and 0.07.  The second form was introduced by Jean-Louis
               Morel for the Windows only, ActivePerl port of "Net::Pcap", in versions 0.04.01
               and 0.04.02.

               The new syntax has been introduced for consistency with the rest of the Perl API
               and the C API of libpcap(3), where $err is always the last argument.

       pcap_lookupnet($dev, \$net, \$mask, \$err)
           Determine the network number and netmask for the device specified in $dev.  The
           function returns 0 on success and sets the $net and $mask parameters with values.  On
           failure it returns -1 and the $err parameter is filled with an appropriate error
           message.

   Packet capture functions
       pcap_open_live($dev, $snaplen, $promisc, $to_ms, \$err)
           Returns a packet capture descriptor for looking at packets on the network.  The $dev
           parameter specifies which network interface to capture packets from.  The $snaplen and
           $promisc parameters specify the maximum number of bytes to capture from each packet,
           and whether to put the interface into promiscuous mode, respectively.  The $to_ms
           parameter specifies a read timeout in milliseconds.  The packet descriptor will be
           undefined if an error occurs, and the $err parameter will be set with an appropriate
           error message.

           Example

               $dev = pcap_lookupdev();
               $pcap = pcap_open_live($dev, 1024, 1, 0, \$err)
                   or die "Can't open device $dev: $err\n";

       pcap_open_dead($linktype, $snaplen)
           Creates and returns a new packet descriptor to use when calling the other functions in
           "libpcap". It is typically used when just using "libpcap" for compiling BPF code.

           Example

               $pcap = pcap_open_dead(0, 1024);

       pcap_open_offline($filename, \$err)
           Return a packet capture descriptor to read from a previously created "savefile".  The
           returned descriptor is undefined if there was an error and in this case the $err
           parameter will be filled.  Savefiles are created using the "pcap_dump_*" commands.

           Example

               $pcap = pcap_open_offline($dump, \$err)
                   or die "Can't read '$dump': $err\n";

       pcap_loop($pcap, $count, \&callback, $user_data)
           Read $count packets from the packet capture descriptor $pcap and call the perl
           function &callback with an argument of $user_data.  If $count is negative, then the
           function loops forever or until an error occurs. Returns 0 if $count is exhausted, -1
           on error, and -2 if the loop terminated due to a call to pcap_breakloop() before any
           packets were processed.

           The callback function is also passed packet header information and packet data like
           so:

               sub process_packet {
                   my ($user_data, $header, $packet) = @_;

                   ...
               }

           The header information is a reference to a hash containing the following fields.

           •   "len" - the total length of the packet.

           •   "caplen" - the actual captured length of the packet data.  This corresponds to the
               snapshot length parameter passed to "open_live()".

           •   "tv_sec" - seconds value of the packet timestamp.

           •   "tv_usec" - microseconds value of the packet timestamp.

           Example

               pcap_loop($pcap, 10, \&process_packet, "user data");

               sub process_packet {
                   my ($user_data, $header, $packet) = @_;
                   # ...
               }

       pcap_breakloop($pcap)
           Sets a flag  that will force "pcap_dispatch()" or "pcap_loop()" to return rather than
           looping; they will return the number of packets that have been processed so far, or -2
           if no packets have been processed so far.

           This routine is safe to use inside a signal handler on UNIX or a console control
           handler on Windows, as it merely sets a flag that is checked within the loop.

           Please see the section on "pcap_breakloop()" in pcap(3) for more information.

       pcap_close($pcap)
           Close the packet capture device associated with the descriptor $pcap.

       pcap_dispatch($pcap, $count, \&callback, $user_data)
           Collect $count packets and process them with callback function &callback.  if $count
           is -1, all packets currently buffered are processed.  If $count is 0, process all
           packets until an error occurs.

       pcap_next($pcap, \%header)
           Return the next available packet on the interface associated with packet descriptor
           $pcap.  Into the %header hash is stored the received packet header.  If not packet is
           available, the return value and header is undefined.

       pcap_next_ex($pcap, \%header, \$packet)
           Reads the next available packet on the interface associated with packet descriptor
           $pcap, stores its header in "\%header" and its data in "\$packet" and returns a
           success/failure indication:

           •   1 means that the packet was read without problems;

           •   0 means that packets are being read from a live capture, and the timeout expired;

           •   "-1" means that an error occurred while reading the packet;

           •   "-2" packets are being read from a dump file, and there are no more packets to
               read from the savefile.

       pcap_compile($pcap, \$filter, $filter_str, $optimize, $netmask)
           Compile the filter string contained in $filter_str and store it in $filter.  A
           description of the filter language can be found in the libpcap source code, or the
           manual page for tcpdump(8) .  The filter is optimized if the $optimize variable is
           true.  The netmask of the network device must be specified in the $netmask parameter.
           The function returns 0 if the compilation was successful, or -1 if there was a
           problem.

       pcap_compile_nopcap($snaplen, $linktype, \$filter, $filter_str, $optimize, $netmask)
           Similar to "compile()" except that instead of passing a $pcap descriptor, one passes
           $snaplen and $linktype directly. Returns -1 if there was an error, but the error
           message is not available.

       pcap_setfilter($pcap, $filter)
           Associate the compiled filter stored in $filter with the packet capture descriptor
           $pcap.

       pcap_freecode($filter)
           Used to free the allocated memory used by a compiled filter, as created by
           "pcap_compile()".

       pcap_offline_filter($filter, \%header, $packet)
           Check whether $filter matches the packet described by header %header and packet data
           $packet. Returns true if the packet matches.

       pcap_setnonblock($pcap, $mode, \$err)
           Set the non-blocking mode of a live capture descriptor, depending on the value of
           $mode (zero to activate and non-zero to deactivate). It has no effect on offline
           descriptors. If there is an error, it returns -1 and sets $err.

           In non-blocking mode, an attempt to read from the capture descriptor with
           "pcap_dispatch()" will, if no packets are currently available to be read, return 0
           immediately rather than blocking waiting for packets to arrive.  "pcap_loop()" and
           "pcap_next()" will not work in non-blocking mode.

       pcap_getnonblock($pcap, \$err)
           Returns the non-blocking state of the capture descriptor $pcap.  Always returns 0 on
           savefiles. If there is an error, it returns -1 and sets $err.

   Savefile commands
       pcap_dump_open($pcap, $filename)
           Open a savefile for writing and return a descriptor for doing so.  If $filename is "-"
           data is written to standard output.  On error, the return value is undefined and
           "pcap_geterr()" can be used to retrieve the error text.

       pcap_dump($dumper, \%header, $packet)
           Dump the packet described by header %header and packet data $packet to the savefile
           associated with $dumper.  The packet header has the same format as that passed to the
           "pcap_loop()" callback.

           Example

               my $dump_file = 'network.dmp';
               my $dev = pcap_lookupdev();
               my $pcap = pcap_open_live($dev, 1024, 1, 0, \$err);

               my $dumper = pcap_dump_open($pcap, $dump_file);
               pcap_loop($pcap, 10, \&process_packet, '');
               pcap_dump_close($dumper);

               sub process_packet {
                   my ($user_data, $header, $packet) = @_;
                   pcap_dump($dumper, $header, $packet);
               }

       pcap_dump_file($dumper)
           Returns the filehandle associated with a savefile opened with "pcap_dump_open()".

       pcap_dump_flush($dumper)
           Flushes the output buffer to the corresponding save file, so that any packets written
           with "pcap_dump()" but not yet written to the save file will be written. Returns -1 on
           error, 0 on success.

       pcap_dump_close($dumper)
           Close the savefile associated with the descriptor $dumper.

   Status functions
       pcap_datalink($pcap)
           Returns the link layer type associated with the given pcap descriptor.

           Example

               $linktype = pcap_datalink($pcap);

       pcap_set_datalink($pcap, $linktype)
           Sets the data link type of the given pcap descriptor to the type specified by
           $linktype. Returns -1 on failure.

       pcap_datalink_name_to_val($name)
           Translates a data link type name, which is a "DLT_" name with the "DLT_" part removed,
           to the corresponding data link type value. The translation is case-insensitive.
           Returns -1 on failure.

           Example

               $linktype = pcap_datalink_name_to_val('LTalk');  # returns DLT_LTALK

       pcap_datalink_val_to_name($linktype)
           Translates a data link type value to the corresponding data link type name.

           Example

               $name = pcap_datalink_val_to_name(DLT_LTALK);  # returns 'LTALK'

       pcap_datalink_val_to_description($linktype)
           Translates a data link type value to a short description of that data link type.

           Example

               $descr = pcap_datalink_val_to_description(DLT_LTALK);  # returns 'Localtalk'

       pcap_snapshot($pcap)
           Returns the snapshot length (snaplen) specified in the call to "pcap_open_live()".

       pcap_is_swapped($pcap)
           This function returns true if the endianness of the currently open savefile is
           different from the endianness of the machine.

       pcap_major_version($pcap)
           Return the major version number of the pcap library used to write the currently open
           savefile.

       pcap_minor_version($pcap)
           Return the minor version of the pcap library used to write the currently open
           savefile.

       pcap_stats($pcap, \%stats)
           Returns a hash containing information about the status of packet capture device $pcap.
           The hash contains the following fields.

           This function is supported only on live captures, not on savefiles; no statistics are
           stored in savefiles, so no statistics are available when reading from a savefile.

           •   "ps_recv" - the number of packets received by the packet capture software.

           •   "ps_drop" - the number of packets dropped by the packet capture software.

           •   "ps_ifdrop" - the number of packets dropped by the network interface.

       pcap_file($pcap)
           Returns the filehandle associated with a savefile opened with "pcap_open_offline()" or
           "undef" if the device was opened with "pcap_open_live()".

       pcap_fileno($pcap)
           Returns the file number of the network device opened with "pcap_open_live()".

       pcap_get_selectable_fd($pcap)
           Returns, on Unix, a file descriptor number for a file descriptor on which one can do a
           "select()" or "poll()" to wait for it to be possible to read packets without blocking,
           if such a descriptor exists, or -1, if no such descriptor exists. Some network devices
           opened with "pcap_open_live()" do not support "select()" or "poll()", so -1 is
           returned for those devices.  See pcap(3) for more details.

   Error handling
       pcap_geterr($pcap)
           Returns an error message for the last error associated with the packet capture device
           $pcap.

       pcap_strerror($errno)
           Returns a string describing error number $errno.

       pcap_perror($pcap, $prefix)
           Prints the text of the last error associated with descriptor $pcap on standard error,
           prefixed by $prefix.

   Information
       pcap_lib_version()
           Returns the name and version of the "pcap" library the module was linked against.

   Perl specific functions
       The following functions are specific to the Perl binding of libpcap.

       pcap_perl_settings($setting)
           Modify internal behaviour of the Perl interpreter.

           •   "PERL_SIGNALS_SAFE", "PERL_SIGNALS_UNSAFE" respectively enable safe or unsafe
               signals delivery. Returns the previous value of "PL_signals".  See "Signals
               handling".

               Example:

                   local $SIG{ALRM} = sub { pcap_breakloop() };
                   alarm 60;

                   pcap_perl_settings(PERL_SIGNALS_UNSAFE);
                   pcap_loop($pcap, 10, \&process_packet, "");
                   pcap_perl_settings(PERL_SIGNALS_SAFE);

   WinPcap specific functions
       The following functions are only available with WinPcap, the Win32 port of the Pcap
       library.  If a called function is not available, it will cleanly "croak()".

       pcap_createsrcstr(\$source, $type, $host, $port, $name, \$err)
           Accepts a set of strings (host name, port, ...), and stores the complete source string
           according to the new format (e.g. "rpcap://1.2.3.4/eth0") in $source.

           This function is provided in order to help the user creating the source string
           according to the new format. An unique source string is used in order to make easy for
           old applications to use the remote facilities.  Think about tcpdump(1), for example,
           which has only one way to specify the interface on which the capture has to be
           started. However, GUI-based programs can find more useful to specify hostname, port
           and interface name separately. In that case, they can use this function to create the
           source string before passing it to the "pcap_open()" function.

           Returns 0 if everything is fine, -1 if some errors occurred. The string containing the
           complete source is returned in the $source variable.

       pcap_parsesrcstr($source, \$type, \$host, \$port, \$name, \$err)
           Parse the source string and stores the pieces in which the source can be split in the
           corresponding variables.

           This call is the other way round of "pcap_createsrcstr()". It accepts a null-
           terminated string and it returns the parameters related to the source.  This includes:

           •   the type of the source (file, WinPcap on a remote adapter, WinPcap on local
               adapter), which is determined by the source prefix ("PCAP_SRC_IF_STRING" and so
               on);

           •   the host on which the capture has to be started (only for remote captures);

           •   the raw name of the source (file name, name of the remote adapter, name of the
               local adapter), without the source prefix. The string returned does not include
               the type of the source itself (i.e. the string returned does not include "file://"
               or "rpcap://" or such).

           The user can omit some parameters in case it is not interested in them.

           Returns 0 if everything is fine, -1 if some errors occurred. The requested values
           (host name, network port, type of the source) are returned into the proper variables
           passed by reference.

       pcap_open($source, $snaplen, $flags, $read_timeout, \$auth, \$err)
           Open a generic source in order to capture / send (WinPcap only) traffic.

           The "pcap_open()" replaces all the "pcap_open_xxx()" functions with a single call.

           This function hides the differences between the different "pcap_open_xxx()" functions
           so that the programmer does not have to manage different opening function. In this
           way, the true "open()" function is decided according to the source type, which is
           included into the source string (in the form of source prefix).

           Returns a pointer to a pcap descriptor which can be used as a parameter to the
           following calls ("compile()" and so on) and that specifies an opened WinPcap session.
           In case of problems, it returns "undef" and the $err variable keeps the error message.

       pcap_setbuff($pcap, $dim)
           Sets the size of the kernel buffer associated with an adapter.  $dim specifies the
           size of the buffer in bytes.  The return value is 0 when the call succeeds, -1
           otherwise.

           If an old buffer was already created with a previous call to "setbuff()", it is
           deleted and its content is discarded.  "open_live()" creates a 1 MB buffer by default.

       pcap_setmode($pcap, $mode)
           Sets the working mode of the interface $pcap to $mode.  Valid values for $mode are
           "MODE_CAPT" (default capture mode) and "MODE_STAT" (statistical mode).

       pcap_setmintocopy($pcap_t, $size)
           Changes the minimum amount of data in the kernel buffer that causes a read from the
           application to return (unless the timeout expires).

       pcap_getevent($pcap)
           Returns the "Win32::Event" object associated with the interface $pcap. Can be used to
           wait until the driver's buffer contains some data without performing a read. See
           Win32::Event.

       pcap_sendpacket($pcap, $packet)
           Send a raw packet to the network. $pcap is the interface that will be used to send the
           packet, $packet contains the data of the packet to send (including the various
           protocol headers). The MAC CRC doesn't need to be included, because it is
           transparently calculated and added by the network interface driver. The return value
           is 0 if the packet is successfully sent, -1 otherwise.

       pcap_sendqueue_alloc($memsize)
           This function allocates and returns a send queue, i.e. a buffer containing a set of
           raw packets that will be transmitted on the network with "sendqueue_transmit()".

           $memsize is the size, in bytes, of the queue, therefore it determines the maximum
           amount of data that the queue will contain. This memory is automatically deallocated
           when the queue ceases to exist.

       pcap_sendqueue_queue($queue, \%header, $packet)
           Adds a packet at the end of the send queue pointed by $queue. The packet header
           %header has the same format as that passed to the "loop()" callback. $ackekt is a
           buffer with the data of the packet.

           The %headerr header structure is the same used by WinPcap and libpcap to store the
           packets in a file, therefore sending a capture file is straightforward. "Raw packet"
           means that the sending application will have to include the protocol headers, since
           every packet is sent to the network as is. The CRC of the packets needs not to be
           calculated, because it will be transparently added by the network interface.

       pcap_sendqueue_transmit($pcap, $queue, $sync)
           This function transmits the content of a queue to the wire. $pcapt is the interface on
           which the packets will be sent, $queue is to a "send_queue" containing the packets to
           send, $sync determines if the send operation must be synchronized: if it is non-zero,
           the packets are sent respecting the timestamps, otherwise they are sent as fast as
           possible.

           The return value is the amount of bytes actually sent. If it is smaller than the size
           parameter, an error occurred during the send. The error can be caused by a
           driver/adapter problem or by an inconsistent/bogus send queue.

CONSTANTS

       "Net::Pcap" exports by default the names of several constants in order to ease the
       development of programs. See "EXPORTS" for details about which constants are exported.

       Here are the descriptions of a few data link types. See pcap(3) for a more complete
       description and semantics associated with each data link.

       •   "DLT_NULL" - BSD loopback encapsulation

       •   "DLT_EN10MB" - Ethernet (10Mb, 100Mb, 1000Mb, and up)

       •   "DLT_RAW" - raw IP

       •   "DLT_IEEE802" - IEEE 802.5 Token Ring

       •   "DLT_IEEE802_11" - IEEE 802.11 wireless LAN

       •   "DLT_FRELAY" - Frame Relay

       •   "DLT_FDDI" - FDDI

       •   "DLT_SLIP" - Serial Line IP

       •   "DLT_PPP" - PPP (Point-to-point Protocol)

       •   "DLT_PPP_SERIAL" - PPP over serial with HDLC encapsulation

       •   "DLT_PPP_ETHER" - PPP over Ethernet

       •   "DLT_IP_OVER_FC" - RFC  2625  IP-over-Fibre  Channel

       •   "DLT_AX25" - Amateur Radio AX.25

       •   "DLT_LINUX_IRDA" - Linux-IrDA

       •   "DLT_LTALK" - Apple  LocalTalk

       •   "DLT_APPLE_IP_OVER_IEEE1394" - Apple IP-over-IEEE 1394 (a.k.a. Firewire)

DIAGNOSTICS

       "arg%d not a scalar ref"
       "arg%d not a hash ref"
       "arg%d not a reference"
           (F) These errors occur if you forgot to give a reference to a function which expect
           one or more of its arguments to be references.

BUGS

       Please report any bugs or feature requests to "bug-Net-Pcap@rt.cpan.org", or through the
       web interface at <http://rt.cpan.org/Dist/Display.html?Queue=Net-Pcap>.  I will be
       notified, and then you'll automatically be notified of progress on your bug as I make
       changes.

       Currently known bugs:

       •   the "ps_recv" field is not correctly set; see t/07-stats.t

       •   "pcap_file()" seems to always returns "undef" for live connection and causes
           segmentation fault for dump files; see t/10-fileno.t

       •   "pcap_fileno()" is documented to return -1 when called on save file, but seems to
           always return an actual file number.  See t/10-fileno.t

       •   "pcap_dump_file()" seems to corrupt something somewhere, and makes scripts dump core.
           See t/05-dump.t

EXAMPLES

       See the eg/ and t/ directories of the "Net::Pcap" distribution for examples on using this
       module.

SEE ALSO

   Perl Modules
       the NetPacket or Net::Frame modules to assemble and disassemble packets.

       Net::Pcap::Reassemble for reassembly of TCP/IP fragments.

       POE::Component::Pcap for using "Net::Pcap" within POE-based programs.

       AnyEvent::Pcap for using "Net::Pcap" within AnyEvent-based programs.

       Net::Packet or NetPacket for decoding and creating network packets.

       Net::Pcap::Easy is a module which provides an easier, more Perl-ish API than "Net::Pcap"
       and integrates some facilities from Net::Netmask and NetPacket.

   Base Libraries
       pcap(3), tcpdump(8)

       The source code for the pcap(3) library is available from <http://www.tcpdump.org/>

       The source code and binary for the Win32 version of the pcap library, WinPcap, is
       available from <http://www.winpcap.org/>

   Articles
       Hacking Linux Exposed: Sniffing with Net::Pcap to stealthily managing iptables rules
       remotely, <http://www.hackinglinuxexposed.com/articles/20030730.html>

       PerlMonks node about Net::Pcap, <http://perlmonks.org/?node_id=170648>

AUTHORS

       Current maintainer is Sébastien Aperghis-Tramoni (SAPER) with the help of Tim Wilde
       (TWILDE).

       Complete list of authors & contributors:

       •   Bo Adler (BOADLER) <thumper (at) alumni.caltech.edu>

       •   Craig Davison

       •   David Farrell

       •   David N. Blank-Edelman <dnb (at) ccs.neu.edu>

       •   James Rouzier (ROUZIER)

       •   Jean-Louis Morel (JLMOREL) <jl_morel (at) bribes.org>

       •   Marco Carnut (KCARNUT) <kiko (at) tempest.com.br>

       •   Patrice Auffret (GOMOR)

       •   Peter Lister (PLISTER) <p.lister (at) cranfield.ac.uk>

       •   Rafaël Garcia-Suarez (RGARCIA)

       •   Sébastien Aperghis-Tramoni (SAPER) <sebastien (at) aperghis.net>

       •   Tim Potter (TIMPOTTER) <tpot (at) frungy.org>

       •   Tim Wilde (TWILDE)

HISTORY

       The original version of "Net::Pcap", version 0.01, was written by Peter Lister using SWIG.

       Version 0.02 was created by Bo Adler with a few bugfixes but not uploaded to CPAN. It
       could be found at: <http://www.buttsoft.com/~thumper/software/perl/Net-Pcap/>

       Versions 0.03 and 0.04 were created by Tim Potter who entirely rewrote "Net::Pcap" using
       XS and wrote the documentation, with the help of David N. Blank-Edelman for testing and
       general polishing.

       Version 0.05 was released by Marco Carnut with fixes to make it work with Cygwin and
       WinPcap.

       Version 0.04.02 was independently created by Jean-Louis Morel but not uploaded on the
       CPAN. It can be found here: <http://www.bribes.org/perl/wnetpcap.html>

       Based on Tim Potter's version 0.04, it included fixes for WinPcap and added wrappers for
       several new libpcap functions as well as WinPcap specific functions.

ACKNOWLEDGEMENTS

       To Paul Johnson for his module Devel::Cover and his patience for helping me using it with
       XS code, which revealed very useful for writing more tests.

       To the beta-testers: Jean-Louis Morel, Max Maischen, Philippe Bruhat, David Morel, Scott
       Lanning, Rafael Garcia-Suarez, Karl Y. Pradene.

COPYRIGHT & LICENSE

       Copyright (C) 2005-2016 Sébastien Aperghis-Tramoni and contributors.  All rights reserved.

       Copyright (C) 2003 Marco Carnut. All rights reserved.

       Copyright (C) 1999, 2000 Tim Potter. All rights reserved.

       Copyright (C) 1998 Bo Adler. All rights reserved.

       Copyright (C) 1997 Peter Lister. All rights reserved.

       This program is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself.