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NAME

       text2pcap - Generate a capture file from an ASCII hexdump of packets

SYNOPSIS

       text2pcap [ -h ] [ -d ] [ -q ] [ -o hex|oct|dec ] [ -l <typenum> ]
       [ -e <l3pid> ] [ -i <proto> ] [ -m <max-packet> ]
       [ -u <srcport>,<destport> ] [ -T <srcport>,<destport> ]
       [ -s <srcport>,<destport>,<tag> ] [ -S <srcport>,<destport>,<ppi> ]
       [ -t <timefmt> ] <infile>|- <outfile>|-

DESCRIPTION

       Text2pcap is a program that reads in an ASCII hex dump and writes the
       data described into a libpcap 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. Multiple packets are read in with
       timestamps differing by one second 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 headers before each packet. This allows
       Wireshark or any other full-packet decoder to handle these dumps.

OPTIONS

       -h  Displays a help message.

       -d  Displays debugging information during the process. Can be used
           multiple times to generate more debugging information.

       -q  Be completely quiet during the process.

       -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.

       -l  Specify the link-layer type of this packet. Default is Ethernet
           (1). See net/bpf.h 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.

       -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 12 to indicate a raw IP packet to Wireshark. Note
           that -l 12 does not work for any non-IP Layer 3 packet (e.g. ARP),
           whereas generating a dummy Ethernet header with -e works for any
           sort of L3 packet.

       -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).

       -m <max-packet>
           Set the maximum packet length, default is 64000.  Useful for
           testing various packet boundaries when only an application level
           datastream is available.  Example:

           od -Ax -tx1 stream | text2pcap -m1460 -T1234,1234 - stream.pcap

           will convert from plain datastream format to a sequence of Ethernet
           TCP packets.

       -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.

       -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.

       -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 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 automatcally 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.

SEE ALSO

       od(1), tcpdump(8), pcap(3), wireshark(1), tshark(1), dumpcap(1),
       mergecap(1), editcap(1), strptime(3).

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>