text2pcap
(1)
Name
text2pcap - Generate a capture file from an ASCII hexdump of
packets
Synopsis
text2pcap [ -a ] [ -d ] [ -D ] [ -e <l3pid> ] [ -h ]
[ -i <proto> ] [ -l <typenum> ] [ -n ] [ -m <max-packet> ]
[ -o hex|oct|dec ] [ -q ] [ -s <srcport>,<destport>,<tag> ]
[ -S <srcport>,<destport>,<ppi> ] [ -t <timefmt> ]
[ -T <srcport>,<destport> ] [ -u <srcport>,<destport> ]
<infile>|- <outfile>|-
Description
The Wireshark Network Analyzer TEXT2PCAP(1)
NAME
text2pcap - Generate a capture file from an ASCII hexdump of
packets
SYNOPSIS
text2pcap [ -a ] [ -d ] [ -D ] [ -e <l3pid> ] [ -h ]
[ -i <proto> ] [ -l <typenum> ] [ -n ] [ -m <max-packet> ]
[ -o hex|oct|dec ] [ -q ] [ -s <srcport>,<destport>,<tag> ]
[ -S <srcport>,<destport>,<ppi> ] [ -t <timefmt> ]
[ -T <srcport>,<destport> ] [ -u <srcport>,<destport> ]
<infile>|- <outfile>|-
DESCRIPTION
Text2pcap is a program that reads in an ASCII hex dump and
writes the data described into a pcap capture file.
text2pcap can read hexdumps with multiple packets in them,
and build a capture file of multiple packets. text2pcap is
also capable of generating dummy Ethernet, IP and UDP, TCP,
or SCTP headers, in order to build fully processable packet
dumps from hexdumps of application-level data only.
Text2pcap understands a hexdump of the form generated by od
-Ax -tx1 -v. In other words, each byte is individually
displayed and surrounded with a space. Each line begins with
an offset describing the position in the file. The offset is
a hex number (can also be octal or decimal - see -o), of
more than two hex digits. Here is a sample dump that
text2pcap can recognize:
000000 00 e0 1e a7 05 6f 00 10 ........
000008 5a a0 b9 12 08 00 46 00 ........
000010 03 68 00 00 00 00 0a 2e ........
000018 ee 33 0f 19 08 7f 0f 19 ........
000020 03 80 94 04 00 00 10 01 ........
000028 16 a2 0a 00 03 50 00 0c ........
000030 01 01 0f 19 03 80 11 01 ........
There is no limit on the width or number of bytes per line.
Also the text dump at the end of the line is ignored.
Bytes/hex numbers can be uppercase or lowercase. Any text
before the offset is ignored, including email forwarding
characters '>'. Any lines of text between the bytestring
lines is ignored. The offsets are used to track the bytes,
so offsets must be correct. Any line which has only bytes
without a leading offset is ignored. An offset is recognized
as being a hex number longer than two characters. Any text
after the bytes is ignored (e.g. the character dump). Any
hex numbers in this text are also ignored. An offset of zero
is indicative of starting a new packet, so a single text
file with a series of hexdumps can be converted into a
packet capture with multiple packets. Packets may be
preceded by a timestamp. These are interpreted according to
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The Wireshark Network Analyzer TEXT2PCAP(1)
the format given on the command line (see -t). If not, the
first packet is timestamped with the current time the
conversion takes place. Multiple packets are written with
timestamps differing by one microsecond each. In general,
short of these restrictions, text2pcap is pretty liberal
about reading in hexdumps and has been tested with a variety
of mangled outputs (including being forwarded through email
multiple times, with limited line wrap etc.)
There are a couple of other special features to note. Any
line where the first non-whitespace character is '#' will be
ignored as a comment. Any line beginning with #TEXT2PCAP is
a directive and options can be inserted after this command
to be processed by text2pcap. Currently there are no
directives implemented; in the future, these may be used to
give more fine grained control on the dump and the way it
should be processed e.g. timestamps, encapsulation type etc.
Text2pcap also allows the user to read in dumps of
application-level data, by inserting dummy L2, L3 and L4
headers before each packet. The user can elect to insert
Ethernet headers, Ethernet and IP, or Ethernet, IP and
UDP/TCP/SCTP headers before each packet. This allows
Wireshark or any other full-packet decoder to handle these
dumps.
OPTIONS
-a Enables ASCII text dump identification. It allows to
identify the start of the ASCII text dump and not
include it in the packet even if it looks like HEX.
NOTE: Do not enable it if the input file does not
contain the ASCII text dump.
-d Displays debugging information during the process. Can
be used multiple times to generate more debugging
information.
-D The text before the packet starts either with an I or O
indicating that the packet is inbound or outbound. This
is only stored if the output format is PCAP-NG.
-e <l3pid>
Include a dummy Ethernet header before each packet.
Specify the L3PID for the Ethernet header in hex. Use
this option if your dump has Layer 3 header and payload
(e.g. IP header), but no Layer 2 encapsulation. Example:
-e 0x806 to specify an ARP packet.
For IP packets, instead of generating a fake Ethernet
header you can also use -l 101 to indicate a raw IP
packet to Wireshark. Note that -l 101 does not work for
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The Wireshark Network Analyzer TEXT2PCAP(1)
any non-IP Layer 3 packet (e.g. ARP), whereas generating
a dummy Ethernet header with -e works for any sort of L3
packet.
-h Displays a help message.
-i <proto>
Include dummy IP headers before each packet. Specify the
IP protocol for the packet in decimal. Use this option
if your dump is the payload of an IP packet (i.e. has
complete L4 information) but does not have an IP header
with each packet. Note that an appropriate Ethernet
header is automatically included with each packet as
well. Example: -i 46 to specify an RSVP packet (IP
protocol 46).
-l Specify the link-layer header type of this packet.
Default is Ethernet (1). See
<http://www.tcpdump.org/linktypes.html> for the complete
list of possible encapsulations. Note that this option
should be used if your dump is a complete hex dump of an
encapsulated packet and you wish to specify the exact
type of encapsulation. Example: -l 7 for ARCNet packets
encapsulated BSD-style.
-m <max-packet>
Set the maximum packet length, default is 65535. Useful
for testing various packet boundaries when only an
application level datastream is available. Example:
od -Ax -tx1 -v stream | text2pcap -m1460 -T1234,1234 -
stream.pcap
will convert from plain datastream format to a sequence
of Ethernet TCP packets.
-n Write PCAP-NG file instead of a PCAP.
-o hex|oct|dec
Specify the radix for the offsets (hex, octal or
decimal). Defaults to hex. This corresponds to the "-A"
option for od.
-q Be completely quiet during the process.
-s <srcport>,<destport>,<tag>
Include dummy SCTP headers before each packet. Specify,
in decimal, the source and destination SCTP ports, and
verification tag, for the packet. Use this option if
your dump is the SCTP payload of a packet but does not
include any SCTP, IP or Ethernet headers. Note that
appropriate Ethernet and IP headers are automatically
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The Wireshark Network Analyzer TEXT2PCAP(1)
also included with each packet. A CRC32C checksum will
be put into the SCTP header.
-S <srcport>,<destport>,<ppi>
Include dummy SCTP headers before each packet. Specify,
in decimal, the source and destination SCTP ports, and a
verification tag of 0, for the packet, and prepend a
dummy SCTP DATA chunk header with a payload protocol
identifier if ppi. Use this option if your dump is the
SCTP payload of a packet but does not include any SCTP,
IP or Ethernet headers. Note that appropriate Ethernet
and IP headers are automatically included with each
packet. A CRC32C checksum will be put into the SCTP
header.
-t <timefmt>
Treats the text before the packet as a date/time code;
timefmt is a format string of the sort supported by
strptime(3). Example: The time "10:15:14.5476" has the
format code "%H:%M:%S."
NOTE: The subsecond component delimiter must be
specified (.) but no pattern is required; the remaining
number is assumed to be fractions of a second.
NOTE: Date/time fields from the current date/time are
used as the default for unspecified fields.
-T <srcport>,<destport>
Include dummy TCP headers before each packet. Specify
the source and destination TCP ports for the packet in
decimal. Use this option if your dump is the TCP payload
of a packet but does not include any TCP, IP or Ethernet
headers. Note that appropriate Ethernet and IP headers
are automatically also included with each packet.
Sequence numbers will start at 0.
-u <srcport>,<destport>
Include dummy UDP headers before each packet. Specify
the source and destination UDP ports for the packet in
decimal. Use this option if your dump is the UDP payload
of a packet but does not include any UDP, IP or Ethernet
headers. Note that appropriate Ethernet and IP headers
are automatically also included with each packet.
Example: -u1000,69 to make the packets look like
TFTP/UDP packets.
ATTRIBUTES
See attributes(5) for descriptions of the following
attributes:
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The Wireshark Network Analyzer TEXT2PCAP(1)
+---------------+---------------------------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+---------------------------------------+
|Availability | diagnostic/wireshark/wireshark-common |
+---------------+---------------------------------------+
|Stability | Uncommitted |
+---------------+---------------------------------------+
SEE ALSO
od(1), pcap(3), wireshark(1), tshark(1), dumpcap(1),
mergecap(1), editcap(1), strptime(3), pcap-filter(5) or
tcpdump(1)
NOTES
Text2pcap is part of the Wireshark distribution. The latest
version of Wireshark can be found at
<http://www.wireshark.org>.
AUTHORS
Ashok Narayanan <ashokn[AT]cisco.com>
This software was built from source available at
https://java.net/projects/solaris-userland. The original
community source was downloaded from
http://www.wireshark.org/download/src/all-
versions/wireshark-1.10.7.tar.bz2
Further information about this software can be found on the
open source community website at http://www.wireshark.org/.
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