editcap - Edit and/or translate the format of capture files
-=head1 SYNOPSYS
+=head1 SYNOPSIS
B<editcap>
-S<[ B<-F> file format ]>
-S<[ B<-T> encapsulation type ]>
+S<[ B<-c> E<lt>packets per fileE<gt> ]>
+S<[ B<-C> E<lt>choplenE<gt> ]>
+S<[ B<-E> E<lt>error probabilityE<gt> ]>
+S<[ B<-F> E<lt>file formatE<gt> ]>
+S<[ B<-A> E<lt>start timeE<gt> ]>
+S<[ B<-B> E<lt>stop timeE<gt> ]>
+S<[ B<-h> ]>
+S<[ B<-i> E<lt>seconds per fileE<gt> ]>
S<[ B<-r> ]>
+S<[ B<-s> E<lt>snaplenE<gt> ]>
+S<[ B<-t> E<lt>time adjustmentE<gt> ]>
+S<[ B<-S> E<lt>strict time adjustmentE<gt> ]>
+S<[ B<-T> E<lt>encapsulation typeE<gt> ]>
+S<[ B<-v> ]>
+I<infile>
+I<outfile>
+S<[ I<packet#>[-I<packet#>] ... ]>
+
+B<editcap>
+S< B<-d> > |
+S< B<-D> E<lt>dup windowE<gt> > |
+S< B<-w> E<lt>dup time windowE<gt> >
S<[ B<-v> ]>
-S<[ B<-s> snaplen ]>
-S<[ B<-t> time adjustment ]>
-S<[ B<-h> ]>
I<infile>
I<outfile>
-S<[ I<record#> ... ]>
=head1 DESCRIPTION
-B<Editcap> is a program that reads a saved capture file and writes some
-or all of the packets in that capture file to another capture file.
-B<Editcap> knows how to read B<libpcap> capture files, including those
-of B<tcpdump>, B<Ethereal>, and other tools that write captures in that
-format. In addition, B<Editcap> can read capture files from B<snoop>
-and B<atmsnoop>, Shomiti/Finisar B<Surveyor>, Novell B<LANalyzer>,
-Network General/Network Associates DOS-based B<Sniffer> (compressed or
-uncompressed), Microsoft B<Network Monitor>, AIX's B<iptrace>, Cinco
-Networks B<NetXRay>, Network Associates Windows-based B<Sniffer>, AG
-Group/WildPackets B<EtherPeek>/B<TokenPeek>/B<AiroPeek>, B<RADCOM>'s
-WAN/LAN analyzer, B<Lucent/Ascend> router debug output, HP-UX's
-B<nettl>, the dump output from B<Toshiba's> ISDN routers, the output
-from B<i4btrace> from the ISDN4BSD project, the output in B<IPLog>
-format from the Cisco Secure Intrusion Detection System, B<pppd logs>
-(pppdump format), the output from VMS's B<TCPIPtrace> utility, the text
-output from the B<DBS Etherwatch> VMS utility, and traffic capture files
-from Visual Networks' Visual UpTime. There is no need to tell
-B<Editcap> what type of file you are reading; it will determine the file
-type by itself. B<Editcap> is also capable of reading any of these file
-formats if they are compressed using gzip. B<Editcap> recognizes this
-directly from the file; the '.gz' extension is not required for this
-purpose.
-
-By default, it writes the capture file in B<libpcap> format, and writes
-all of the packets in the capture file to the output file. The B<-F>
+B<Editcap> is a program that reads some or all of the captured packets from the
+I<infile>, optionally converts them in various ways and writes the
+resulting packets to the capture I<outfile> (or outfiles).
+
+By default, it reads all packets from the I<infile> and writes them to the
+I<outfile> in libpcap file format.
+
+An optional list of packet numbers can be specified on the command tail;
+individual packet numbers separated by whitespace and/or ranges of packet
+numbers can be specified as I<start>-I<end>, referring to all packets from
+I<start> to I<end>. By default the selected packets with those numbers will
+I<not> be written to the capture file. If the B<-r> flag is specified, the
+whole packet selection is reversed; in that case I<only> the selected packets
+will be written to the capture file.
+
+B<Editcap> can also be used to remove duplicate packets. Several different
+options (B<-d>, B<-D> and B<-w>) are used to control the packet window
+or relative time window to be used for duplicate comparison.
+
+B<Editcap> is able to detect, read and write the same capture files that
+are supported by B<Wireshark>.
+The input file doesn't need a specific filename extension; the file
+format and an optional gzip compression will be automatically detected.
+Near the beginning of the DESCRIPTION section of wireshark(1) or
+L<http://www.wireshark.org/docs/man-pages/wireshark.html>
+is a detailed description of the way B<Wireshark> handles this, which is
+the same way B<Editcap> handles this.
+
+B<Editcap> can write the file in several output formats. The B<-F>
flag can be used to specify the format in which to write the capture
-file; it can write the file in B<libpcap> format (standard B<libpcap>
-format, a modified format used by some patched versions of B<libpcap>,
-the format used by Red Hat Linux 6.1, or the format used by SuSE Linux
-6.3), B<snoop> format, uncompressed B<Sniffer> format, Microsoft
-B<Network Monitor> 1.x format, the format used by Windows-based versions
-of the B<Sniffer> software, and the format used by Visual Networks'
-software.
-
-A list of packet numbers can be specified on the command line; the
-packets with those numbers will I<not> be written to the capture file,
-unless the B<-r> flag is specified, in which case I<only> those packets
-will be written to the capture file. Ranges of packet numbers can be
-specified as I<start>-I<end>, referring to all packets from I<start> to
-I<end> (removing them all if B<-r> isn't specified, including them all
-if B<-r> is specified).
-
-If the B<-s> flag is used to specify a snapshot length, frames in the
+file; B<editcap -F> provides a list of the available output formats.
+
+=head1 OPTIONS
+
+=over 4
+
+=item -c E<lt>packets per fileE<gt>
+
+Splits the packet output to different files based on uniform packet counts
+with a maximum of <packets per file> each. Each output file will
+be created with a suffix -nnnnn, starting with 00000. If the specified
+number of packets is written to the output file, the next output file is
+opened. The default is to use a single output file.
+
+=item -C E<lt>choplenE<gt>
+
+Sets the chop length to use when writing the packet data.
+Each packet is chopped at the packet end by a few <choplen> bytes of data.
+
+This is useful in the rare case that the conversion between two file
+formats leaves some random bytes at the end of each packet.
+
+=item -d
+
+Attempts to remove duplicate packets. The length and MD5 hash of the
+current packet are compared to the previous four (4) packets. If a
+match is found, the current packet is skipped. This option is equivalent
+to using the option B<-D 5>.
+
+=item -D E<lt>dup windowE<gt>
+
+Attempts to remove duplicate packets. The length and MD5 hash of the
+current packet are compared to the previous <dup window> - 1 packets.
+If a match is found, the current packet is skipped.
+
+The use of the option B<-D 0> combined with the B<-v> option is useful
+in that each packet's Packet number, Len and MD5 Hash will be printed
+to standard out. This verbose output (specifically the MD5 hash strings)
+can be useful in scripts to identify duplicate packets across trace
+files.
+
+The <dup window> is specified as an integer value between 0 and 1000000 (inclusive).
+
+NOTE: Specifying large <dup window> values with large tracefiles can
+result in very long processing times for B<editcap>.
+
+=item -w E<lt>dup time windowE<gt>
+
+Attempts to remove duplicate packets. The current packet's arrival time
+is compared with up to 1000000 previous packets. If the packet's relative
+arrival time is I<less than or equal to> the <dup time window> of a previous packet
+and the packet length and MD5 hash of the current packet are the same then
+the packet to skipped. The duplicate comparison test stops when
+the current packet's relative arrival time is greater than <dup time window>.
+
+The <dup time window> is specified as I<seconds>[I<.fractional seconds>].
+
+The [.fractional seconds] component can be specified to nine (9) decimal
+places (billionths of a second) but most typical trace files have resolution
+to six (6) decimal places (millionths of a second).
+
+NOTE: Specifying large <dup time window> values with large tracefiles can
+result in very long processing times for B<editcap>.
+
+NOTE: The B<-w> option assumes that the packets are in chronological order.
+If the packets are NOT in chronological order then the B<-w> duplication
+removal option may not identify some duplicates.
+
+=item -E E<lt>error probabilityE<gt>
+
+Sets the probability that bytes in the output file are randomly changed.
+B<Editcap> uses that probability (between 0.0 and 1.0 inclusive)
+to apply errors to each data byte in the file. For instance, a
+probability of 0.02 means that each byte has a 2% chance of having an error.
+
+This option is meant to be used for fuzz-testing protocol dissectors.
+
+=item -F E<lt>file formatE<gt>
+
+Sets the file format of the output capture file.
+B<Editcap> can write the file in several formats, B<editcap -F>
+provides a list of the available output formats. The default
+is the B<libpcap> format.
+
+=item -A E<lt>start timeE<gt>
+
+Saves only the packets whose timestamp is on or after start time.
+The time is given in the following format YYYY-MM-DD HH:MM:SS
+
+=item -B E<lt>stop timeE<gt>
+
+Saves only the packets whose timestamp is before stop time.
+The time is given in the following format YYYY-MM-DD HH:MM:SS
+
+=item -h
+
+Prints the version and options and exits.
+
+=item -i E<lt>seconds per fileE<gt>
+
+Splits the packet output to different files based on uniform time intervals
+using a maximum interval of <seconds per file> each. Each output file will
+be created with a suffix -nnnnn, starting with 00000. If packets for the specified
+time interval are written to the output file, the next output file is
+opened. The default is to use a single output file.
+
+=item -r
+
+Reverse the packet selection.
+Causes the packets whose packet numbers are specified on the command
+line to be written to the output capture file, instead of discarding them.
+
+=item -s E<lt>snaplenE<gt>
+
+Sets the snapshot length to use when writing the data.
+If the B<-s> flag is used to specify a snapshot length, packets in the
input file with more captured data than the specified snapshot length
will have only the amount of data specified by the snapshot length
-written to the output file. This may be useful if the program that is
+written to the output file.
+
+This may be useful if the program that is
to read the output file cannot handle packets larger than a certain size
(for example, the versions of snoop in Solaris 2.5.1 and Solaris 2.6
-appear to reject Ethernet frames larger than the standard Ethernet MTU,
+appear to reject Ethernet packets larger than the standard Ethernet MTU,
making them incapable of handling gigabit Ethernet captures if jumbo
-frames were used).
+packets were used).
+=item -t E<lt>time adjustmentE<gt>
+
+Sets the time adjustment to use on selected packets.
If the B<-t> flag is used to specify a time adjustment, the specified
-adjustment will be applied to all selected frames in the capture file.
+adjustment will be applied to all selected packets in the capture file.
The adjustment is specified as [-]I<seconds>[I<.fractional seconds>].
-For example, B<-t> 3600 advances the timestamp on selected frames by one
-hour while B<-t> -0.5 reduces the timestamp on selected frames by
-one-half second. This feature is useful when synchronizing dumps
+For example, B<-t> 3600 advances the timestamp on selected packets by one
+hour while B<-t> -0.5 reduces the timestamp on selected packets by
+one-half second.
+
+This feature is useful when synchronizing dumps
collected on different machines where the time difference between the
two machines is known or can be estimated.
+=item -S E<lt>strict time adjustmentE<gt>
+
+Time adjust selected packets to insure strict chronological order.
+
+The <strict time adjustment> value represents relative seconds
+specified as [-]I<seconds>[I<.fractional seconds>].
+
+As the capture file is processed each packet's absolute time is
+I<possibly> adjusted to be equal to or greater than the previous
+packet's absolute timestamp depending on the <strict time
+adjustment> value.
+
+If <strict time adjustment> value is 0 or greater (e.g. 0.000001)
+then B<only> packets with a timestamp less than the previous packet
+will adjusted. The adjusted timestamp value will be set to be
+equal to the timestamp value of the previous packet plus the value
+of the <strict time adjustment> value. A <strict time adjustment>
+value of 0 will adjust the minimum number of timestamp values
+necessary to insure that the resulting capture file is in
+strict chronological order.
+
+If <strict time adjustment> value is specified as a
+negative value, then the timestamp values of B<all>
+packets will be adjusted to be equal to the timestamp value
+of the previous packet plus the absolute value of the
+<lt>strict time adjustment<gt> value. A <strict time
+adjustment> value of -0 will result in all packets
+having the timestamp value of the first packet.
+
+This feature is useful when the trace file has an occasional
+packet with a negative delta time relative to the previous
+packet.
+
+=item -T E<lt>encapsulation typeE<gt>
+
+Sets the packet encapsulation type of the output capture file.
If the B<-T> flag is used to specify an encapsulation type, the
encapsulation type of the output capture file will be forced to the
-specified type, rather than being the type appropriate to the
-encapsulation type of the input capture file. Note that this merely
+specified type.
+B<editcap -T> provides a list of the available types. The default
+type is the one appropriate to the encapsulation type of the input
+capture file.
+
+Note: this merely
forces the encapsulation type of the output file to be the specified
type; the packet headers of the packets will not be translated from the
encapsulation type of the input capture file to the specified
encapsulation type (for example, it will not translate an Ethernet
capture to an FDDI capture if an Ethernet capture is read and 'B<-T
-fddi>' is specified).
+fddi>' is specified). If you need to remove/add headers from/to a
+packet, you will need od(1)/text2pcap(1).
-=head1 OPTIONS
+=item -v
-=over 4
+Causes B<editcap> to print verbose messages while it's working.
-=item -F
+Use of B<-v> with the de-duplication switches of B<-d>, B<-D> or B<-w>
+will cause all MD5 hashes to be printed whether the packet is skipped
+or not.
-Sets the file format of the output capture file.
+=back
-=item -T
+=head1 EXAMPLES
-Sets the packet encapsulation type of the output capture file.
+To see more detailed description of the options use:
-=item -r
+ editcap -h
-Causes the packets whose packet numbers are specified on the command
-line to be written to the output capture file, and no other packets to
-be written to the output capture file.
+To shrink the capture file by truncating the packets at 64 bytes and writing it as Sun snoop file use:
-=item -v
+ editcap -s 64 -F snoop capture.pcap shortcapture.snoop
-Causes B<editcap> to print a number of messages while it's working.
+To delete packet 1000 from the capture file use:
-=item -s
+ editcap capture.pcap sans1000.pcap 1000
-Sets the snapshot length to use when writing the data.
+To limit a capture file to packets from number 200 to 750 (inclusive) use:
-=item -t
+ editcap -r capture.pcap small.pcap 200-750
-Sets the time adjustment to use on selected frames.
+To get all packets from number 1-500 (inclusive) use:
-=item -h
+ editcap -r capture.pcap first500.pcap 1-500
-Prints the version and options and exits.
+or
+
+ editcap capture.pcap first500.pcap 501-9999999
+
+To exclude packets 1, 5, 10 to 20 and 30 to 40 from the new file use:
+
+ editcap capture.pcap exclude.pcap 1 5 10-20 30-40
+
+To select just packets 1, 5, 10 to 20 and 30 to 40 for the new file use:
+
+ editcap -r capture.pcap select.pcap 1 5 10-20 30-40
+
+To remove duplicate packets seen within the prior four frames use:
+
+ editcap -d capture.pcap dedup.pcap
+
+To remove duplicate packets seen within the prior 100 frames use:
+
+ editcap -D 101 capture.pcap dedup.pcap
+
+To remove duplicate packets seen I<equal to or less than> 1/10th of a second:
+
+ editcap -w 0.1 capture.pcap dedup.pcap
+
+To display the MD5 hash for all of the packets (and NOT generate any
+real output file):
+
+ editcap -v -D 0 capture.pcap /dev/null
+
+or on Windows systems
+
+ editcap -v -D 0 capture.pcap NUL
+
+To advance the timestamps of each packet forward by 3.0827 seconds:
+
+ editcap -t 3.0827 capture.pcap adjusted.pcap
+
+To insure all timestamps are in strict chronological order:
+
+ editcap -S 0 capture.pcap adjusted.pcap
+
+To introduce 5% random errors in a capture file use:
+
+=over 4
+
+ editcap -E 0.05 capture.pcap capture_error.pcap
+
+=back
=head1 SEE ALSO
-L<tcpdump(8)>, L<pcap(3)>, L<ethereal(1)>, L<mergecap(1)>
+tcpdump(8), pcap(3), wireshark(1), tshark(1), mergecap(1), dumpcap(1),
+capinfos(1), text2pcap(1), od(1)
=head1 NOTES
-B<Editcap> is part of the B<Ethereal> distribution. The latest version
-of B<Ethereal> can be found at B<http://www.ethereal.com>.
+B<Editcap> is part of the B<Wireshark> distribution. The latest version
+of B<Wireshark> can be found at L<http://www.wireshark.org>.
+
+HTML versions of the Wireshark project man pages are available at:
+L<http://www.wireshark.org/docs/man-pages>.
=head1 AUTHORS
Original Author
-------- ------
- Richard Sharpe <sharpe@ns.aus.com>
+ Richard Sharpe <sharpe[AT]ns.aus.com>
Contributors
------------
- Guy Harris <guy@alum.mit.edu>
+ Guy Harris <guy[AT]alum.mit.edu>
+ Ulf Lamping <ulf.lamping[AT]web.de>
git.samba.org / obnox / wireshark / wip.git / blobdiff