Provided by: plc-utils-extra_0.0.6+git20211210.358dfcf-2_amd64 
NAME
efsu - Ethernet Frame Send Utility
SYNOPSIS
efsu [options] file [file] [...]
efsu [options] [<stdin]
DESCRIPTION
Sends custom Ethernet frames over a specific host Ethernet interface.
A frame is specified as a text stream of hexadecimal octets read from one or more frame
description files or from stdin. Each octet is converted to a binary byte, buffered and
transmitted over the network on the specified host interface. The program assumes that
frames are valid and will transmit whatever you specify, right or wrong. The program only
checks minimum and maximum frame length.
Frame descriptions are stored as plain text files. Multiple frames may be specified in
one file by separating them with a semicolon. All descriptions in a file are read and
sent immediately but multiple files may be specified on the command line and options allow
pauses between files, command line repetition and pauses between command line iterations.
A frame descriptions is a continuous stream of hexadecimal digits. Intervening text,
punctuation, white space and comments are discarded. Hex characters inside script-style,
C-style or C++-style comments are ignored. Script-style comments include all characters
between a hash ('#') and the next newline or EOF. C-style and C++-style comments follow
normal language rules. Comments may be used to document frame descriptions or hide frame
segments. In the end, there must be an even number of hex digits that represent 60 to
1518 octets;
OPTIONS
-d address
Replace the destination Ethernet address of each transmitted frame with the option
argument. The destination address consists of 12 hex digits in upper, lower or
mixed case. Octets may be seperated with colons for clarity but colons are not
required.
-e ethertype
Echo received frames having ethertype. This effectively filters received frames
but does not filter transmitted frames. The ethertype is expressed in hexadecimal
without the "0x" prefix. The keyword "hp10" can be used for 887B and keyword
"hpav" can be used for 88E1.
-h Replace the source address of each transmitted frame with the Ethernet address of
the host interface used to send the frame. This allows frames to be sent correctly
from any host interface. Use option -i to specify an interface.
-i interface
The host interface used to send frames. The default is "eth1" because most people
use "eth0" as their principle network connection; however, if the string "PLC" is
defined in the environment then it will over-ride the program default. Any
interface specified on the command line will over-ride the default.
-l count
Repeat command line count times by re-sending all files each time. The default is
1.
-p seconds
Pause between each file on the command line. The default is 0 seconds.
-t timer
Read timeout in milliseconds. Values range from 0 through UINT_MAX. This is the
maximum time allowed for a response. The default is 50 milliseconds.
-v Dumps transmitted frames on stdout as they are sent. If an Ethertype was specified
using option -e the received frames having that Ethertype will also be dumped.
-w seconds
Wait between command line iterations. The default is 0 seconds.
ARGUMENTS
file The name of a file containing one or more frame specifications. When more than one
file is specified, efsu behaves like the cat utility by reading and sending each
file in turn. The program makes no assumptions based on filename or extension and
enforces no filename conventions; however, giving frame description files the *.hex
extension is a good convention. Some toolkit distributions include example .hex
files in the source folder. These files are not needed for proper execution and
may be deleted.
NOTES
One way to create a frame description file is to cut-and-paste output from a packet
sniffer program and discard the line numbers and ASCII text columns. You can then break
out selected frame segments onto new lines and insert comments.
EXAMPLES
For example, a simple file might look like:
#!/usr/local/bin/efsu -ieth0
# file: abc.hex
# =====================================
# this is an example frame description;
# -------------------------------------
00 B0 52 00 00 01
// 00 B0 52 BE DE 73
00 E0 45 DA DA 07
88 E1
/* content */
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00000000 0000 00 /* control byte */ 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
The bang path permits direct execution of the file if 1) efsu is installed in the bang
path directory, 2) the description file has execute permissions and 3) the user has
execute privileges for that file. The script-style, C++-style and C-style comments are
ignored along with any white space. Only the hexadecimal octets are read and sent. Since
the number of octets exceeds 60 and the number of digits is even, efsu will report no
errors and send the packet. There is no guarantee that this packet is valid.
Assuming the above file is named abc.hex, we can transmit the file over the network as an
Ethernet frame with the next command. A hexadecimal dump of the transmitted frame appears
on the console because option -v is present.
# efsu abc.hex -v
00000000 00 B0 52 00 00 01 00 E0 45 DA DA 07 88 E1 00 00 ..R.....E.......
00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000020 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000030 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000040 00 00 00 00 00 00 ......
Since every host interface has a different hardware address, one can replace the source
address of transmitted frames with the actual host interface address using option -h.
Observe that the source address above has been replaced with that of the local host
interface used to transmit the frame.
# efsu abc.hex -vh
00000000 00 B0 52 00 00 01 00 0F EA 10 D5 1C 88 E1 00 00 ..R.............
00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000020 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000030 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000040 00 00 00 00 00 00 ......
You can also direct the frame to another device using option -d. Observe that the
destination address above has been replaced with the one specified on the command line.
# efsu abc.hex -vhd 00b052beef01
00000000 00 B0 52 BE EF 01 00 0F EA 10 D5 1C 88 E1 00 00 ..R.............
00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000020 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000030 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000040 00 00 00 00 00 00 ......
SEE ALSO
amp(1), hpav(1)
CREDITS
Charles Maier