1TEXT2PCAP(1) The Wireshark Network Analyzer TEXT2PCAP(1)
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6 text2pcap - Generate a capture file from an ASCII hexdump of packets
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9 text2pcap [ -a ] [ -d ] [ -e <l3pid> ] [ -h ] [ -i <proto> ]
10 [ -l <typenum> ] [ -m <max-packet> ] [ -o hex|oct|dec ] [ -q ]
11 [ -s <srcport>,<destport>,<tag> ] [ -S <srcport>,<destport>,<ppi> ]
12 [ -t <timefmt> ] [ -T <srcport>,<destport> ]
13 [ -u <srcport>,<destport> ] <infile>|- <outfile>|-
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16 Text2pcap is a program that reads in an ASCII hex dump and writes the
17 data described into a libpcap capture file. text2pcap can read
18 hexdumps with multiple packets in them, and build a capture file of
19 multiple packets. text2pcap is also capable of generating dummy
20 Ethernet, IP and UDP, TCP, or SCTP headers, in order to build fully
21 processable packet dumps from hexdumps of application-level data only.
22 Text2pcap understands a hexdump of the form generated by od -Ax -tx1
24 -v. In other words, each byte is individually displayed and surrounded
25 with a space. Each line begins with an offset describing the position
26 in the file. The offset is a hex number (can also be octal or decimal -
27 see -o), of more than two hex digits. Here is a sample dump that
28 text2pcap can recognize:
29 000000 00 e0 1e a7 05 6f 00 10 ........
31 000008 5a a0 b9 12 08 00 46 00 ........
32 000010 03 68 00 00 00 00 0a 2e ........
33 000018 ee 33 0f 19 08 7f 0f 19 ........
34 000020 03 80 94 04 00 00 10 01 ........
35 000028 16 a2 0a 00 03 50 00 0c ........
36 000030 01 01 0f 19 03 80 11 01 ........
37 There is no limit on the width or number of bytes per line. Also the
39 text dump at the end of the line is ignored. Bytes/hex numbers can be
40 uppercase or lowercase. Any text before the offset is ignored,
41 including email forwarding characters '>'. Any lines of text between
42 the bytestring lines is ignored. The offsets are used to track the
43 bytes, so offsets must be correct. Any line which has only bytes
44 without a leading offset is ignored. An offset is recognized as being a
45 hex number longer than two characters. Any text after the bytes is
46 ignored (e.g. the character dump). Any hex numbers in this text are
47 also ignored. An offset of zero is indicative of starting a new packet,
48 so a single text file with a series of hexdumps can be converted into a
49 packet capture with multiple packets. Packets may be preceded by a
50 timestamp. These are interpreted according to the format given on the
51 command line (see -t). If not, the first packet is timestamped with the
52 current time the conversion takes place. Multiple packets are written
53 with timestamps differing by one microsecond each. In general, short
54 of these restrictions, text2pcap is pretty liberal about reading in
55 hexdumps and has been tested with a variety of mangled outputs
56 (including being forwarded through email multiple times, with limited
57 line wrap etc.)
58 There are a couple of other special features to note. Any line where
60 the first non-whitespace character is '#' will be ignored as a comment.
61 Any line beginning with #TEXT2PCAP is a directive and options can be
62 inserted after this command to be processed by text2pcap. Currently
63 there are no directives implemented; in the future, these may be used
64 to give more fine grained control on the dump and the way it should be
65 processed e.g. timestamps, encapsulation type etc.
66 Text2pcap also allows the user to read in dumps of application-level
68 data, by inserting dummy L2, L3 and L4 headers before each packet. The
69 user can elect to insert Ethernet headers, Ethernet and IP, or
70 Ethernet, IP and UDP/TCP/SCTP headers before each packet. This allows
71 Wireshark or any other full-packet decoder to handle these dumps.
72
74 -a Enables ASCII text dump identification. It allows to identify the
75 start of the ASCII text dump and not include it in the packet even
76 if it looks like HEX.
77 NOTE: Do not enable it if the input file does not contain the ASCII
79 text dump.
80 -d Displays debugging information during the process. Can be used
82 multiple times to generate more debugging information.
83 -e <l3pid>
85 Include a dummy Ethernet header before each packet. Specify the
86 L3PID for the Ethernet header in hex. Use this option if your dump
87 has Layer 3 header and payload (e.g. IP header), but no Layer 2
88 encapsulation. Example: -e 0x806 to specify an ARP packet.
89 For IP packets, instead of generating a fake Ethernet header you
91 can also use -l 101 to indicate a raw IP packet to Wireshark. Note
92 that -l 101 does not work for any non-IP Layer 3 packet (e.g. ARP),
93 whereas generating a dummy Ethernet header with -e works for any
94 sort of L3 packet.
95 -h Displays a help message.
97 -i <proto>
99 Include dummy IP headers before each packet. Specify the IP
100 protocol for the packet in decimal. Use this option if your dump is
101 the payload of an IP packet (i.e. has complete L4 information) but
102 does not have an IP header with each packet. Note that an
103 appropriate Ethernet header is automatically included with each
104 packet as well. Example: -i 46 to specify an RSVP packet (IP
105 protocol 46).
106 -l Specify the link-layer header type of this packet. Default is
108 Ethernet (1). See <http://www.tcpdump.org/linktypes.html> for the
109 complete list of possible encapsulations. Note that this option
110 should be used if your dump is a complete hex dump of an
111 encapsulated packet and you wish to specify the exact type of
112 encapsulation. Example: -l 7 for ARCNet packets encapsulated BSD-
113 style.
114 -m <max-packet>
116 Set the maximum packet length, default is 64000. Useful for
117 testing various packet boundaries when only an application level
118 datastream is available. Example:
119 od -Ax -tx1 stream | text2pcap -m1460 -T1234,1234 - stream.pcap
121 will convert from plain datastream format to a sequence of Ethernet
123 TCP packets.
124 -o hex|oct|dec
126 Specify the radix for the offsets (hex, octal or decimal). Defaults
127 to hex. This corresponds to the "-A" option for od.
128 -q Be completely quiet during the process.
130 -s <srcport>,<destport>,<tag>
132 Include dummy SCTP headers before each packet. Specify, in
133 decimal, the source and destination SCTP ports, and verification
134 tag, for the packet. Use this option if your dump is the SCTP
135 payload of a packet but does not include any SCTP, IP or Ethernet
136 headers. Note that appropriate Ethernet and IP headers are
137 automatically also included with each packet. A CRC32C checksum
138 will be put into the SCTP header.
139 -S <srcport>,<destport>,<ppi>
141 Include dummy SCTP headers before each packet. Specify, in
142 decimal, the source and destination SCTP ports, and a verification
143 tag of 0, for the packet, and prepend a dummy SCTP DATA chunk
144 header with a payload protocol identifier if ppi. Use this option
145 if your dump is the SCTP payload of a packet but does not include
146 any SCTP, IP or Ethernet headers. Note that appropriate Ethernet
147 and IP headers are automatically included with each packet. A
148 CRC32C checksum will be put into the SCTP header.
149 -t <timefmt>
151 Treats the text before the packet as a date/time code; timefmt is a
152 format string of the sort supported by strptime(3). Example: The
153 time "10:15:14.5476" has the format code "%H:%M:%S."
154 NOTE: The subsecond component delimiter must be specified (.) but
156 no pattern is required; the remaining number is assumed to be
157 fractions of a second.
158 NOTE: Date/time fields from the current date/time are used as the
160 default for unspecified fields.
161 -T <srcport>,<destport>
163 Include dummy TCP headers before each packet. Specify the source
164 and destination TCP ports for the packet in decimal. Use this
165 option if your dump is the TCP payload of a packet but does not
166 include any TCP, IP or Ethernet headers. Note that appropriate
167 Ethernet and IP headers are automatically also included with each
168 packet. Sequence numbers will start at 0.
169 -u <srcport>,<destport>
171 Include dummy UDP headers before each packet. Specify the source
172 and destination UDP ports for the packet in decimal. Use this
173 option if your dump is the UDP payload of a packet but does not
174 include any UDP, IP or Ethernet headers. Note that appropriate
175 Ethernet and IP headers are automatically also included with each
176 packet. Example: -u1000,69 to make the packets look like TFTP/UDP
177 packets.
178
180 od(1), pcap(3), wireshark(1), tshark(1), dumpcap(1), mergecap(1),
181 editcap(1), strptime(3), pcap-filter(7) or tcpdump(8) if it doesn't
182 exist.
183
185 Text2pcap is part of the Wireshark distribution. The latest version of
186 Wireshark can be found at <http://www.wireshark.org>.
187
189 Ashok Narayanan <ashokn[AT]cisco.com>
1901.8.10 2013-07-29 TEXT2PCAP(1)