OWTAP(1)

🎀 OWTAP 🎀

okay bestie, gather round, because we're talking about owtap — the packet sniffer for the owserver protocol, living in the One-Wire File System universe. it's a (1) manual page, section 1, programs, you know the vibe. let's get into it 💅

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✨ SYNOPSIS ✨

owtap -p owtap-tcp-port -s owserver-tcp-port

that's it. two ports, one sniffer, infinite slay 🫶

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💖 DESCRIPTION 💖

🌈 1-Wire 🌈

so, 1-wire is a wiring protocol AND a whole series of devices, designed and manufactured by Dallas Semiconductor, Inc. ✨ it's a low-power, low-speed, low-connector scheme, and here's the iconic part: the data line can also provide power. one wire doing the absolute most, we love a multitasker.

every single device gets a unique and unalterable number during manufacture — like a government name but permanent fr fr. there are a WIDE variety of devices out there:

• memory
• sensors (humidity, temperature, voltage, contact, current)
• switches
• timers
• data loggers

and more complex devices (like thermocouple sensors) can be built out of these basic ones. there are even 1-wire devices that have encryption included 👑

the 1-wire scheme uses a single bus master and multiple slaves on the same wire. the bus master initiates ALL communication — main character energy, obviously. the slaves can be individually discovered and addressed using their unique ID.

bus masters come in a variety of configurations, including serial, parallel, i2c, network or USB adapters.

🦋 OWFS design 🦋

OWFS is a suite of programs designed to make the 1-wire bus and its devices easily accessible. the underlying principle? create a virtual filesystem, where the unique ID is the directory, and the individual properties of the device are represented as simple files you can read and write. it's giving "everything is a file" but make it 1-wire.

details of the individual slave or master design are hidden behind a consistent interface. the goal is to provide an easy set of tools for a software designer to create monitoring or control applications. there are some performance enhancements in the implementation too, including:

• data caching
• parallel access to bus masters
• aggregation of device communication

but still, the fundamental goal has been ease of use, flexibility and correctness — not speed. periodt.

🫶 owserver 🫶

owserver (1) is the backend component of the OWFS 1-wire bus control system. owserver (1) arbitrates access to the bus from multiple client processes. the physical bus is usually connected to a serial or USB port, and other processes connect to owserver (1) over network sockets (tcp port).

frontend clients include:

• a filesystem representation: owfs (1)
• a webserver: owhttpd (1)

direct language bindings are also available, e.g: owperl (3).

there are also many light-weight clients that can only talk to owserver (1) and not to the 1-Wire bus directly. they include shell and multiple language modules (perl, Visual Basic, python, ...).

💅 owserver protocol 💅

all the owserver (1) clients use the owserver protocol for communication. the owserver protocol is a well documented tcp/ip client/server protocol. it's been assigned the "well known port" default of 4304. iconic number, no notes.

👑 owtap 👑

owtap (1) is interposed between owserver (1) and clients, to display and help resolve communication problems. network communication is forwarded in both directions, but a visual display is also created, with statistics and "drill-down" of individual packets. it's literally a little spy sitting in the middle of your traffic, but in a helpful way 🕵️♀️✨

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🔥 SPECIFIC OPTIONS 🔥

-p

• -p — TCP port or IPaddress:port for owtap. other OWFS programs will access owtap via this address. (e.g. owdir -s IP:port /)

-s

• -s — TCP port or IPaddress:port for owserver. this is the tcp port (IP:port) for the "upstream" owserver.

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🌸 EXAMPLE 🌸

if owserver (1) is started:

owserver -p 4304 -d /dev/ttyS0

that's owserver on tcp port 4304, and it connects to a physical 1-wire bus on a serial port.

you can directly query owserver (1) with:

owdir -s 4304 /

to see the protocol in action:

owtap -s 4304 -p 3000
owdir -p 3000 /

in this case owtap (1) is connecting to owserver (1) on the original port (4304) and offering a new port (3000) for clients. so owtap is like the mutual friend introducing everybody at the party 💖

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🧚 PLATFOMS 🧚

(yes bestie, that's how the heading is spelled here, we're keeping it exactly as it is 💅)

owtap (1) is a pure Tcl/TK program and will run wherever Tcl/TK is available — Windows, Macintosh, Linux, Unix. cross-platform queen 👑

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🍓 LINKS 🍓

owserver protocol

http://www.owfs.org/index.php?page=owserver-protocol

Tcl/TK

http://www.tcl.tk

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⭐ SEE ALSO ⭐

Programs

owfs (1) owhttpd (1) owftpd (1) owserver (1) owdir (1) owread (1) owwrite (1) owpresent (1) owtap (1)

Configuration and testing

owfs (5) owtap (1) owmon (1)

Language bindings

owtcl (3) owperl (3) owcapi (3)

Clocks

DS1427 (3) DS1904(3) DS1994 (3) DS2404 (3) DS2404S (3) DS2415 (3) DS2417 (3)

ID

DS2401 (3) DS2411 (3) DS1990A (3)

Memory

DS1982 (3) DS1985 (3) DS1986 (3) DS1991 (3) DS1992 (3) DS1993 (3) DS1995 (3) DS1996 (3) DS2430A (3) DS2431 (3) DS2433 (3) DS2502 (3) DS2506 (3) DS28E04 (3) DS28EC20 (3)

Switches

DS2405 (3) DS2406 (3) DS2408 (3) DS2409 (3) DS2413 (3) DS28EA00 (3)

Temperature

DS1822 (3) DS1825 (3) DS1820 (3) DS18B20 (3) DS18S20 (3) DS1920 (3) DS1921 (3) DS1821 (3) DS28EA00 (3) DS28E04 (3)

Humidity

DS1922 (3)

Voltage

DS2450 (3)

Resistance

DS2890 (3)

Multifunction (current, voltage, temperature)

DS2436 (3) DS2437 (3) DS2438 (3) DS2751 (3) DS2755 (3) DS2756 (3) DS2760 (3) DS2770 (3) DS2780 (3) DS2781 (3) DS2788 (3) DS2784 (3)

Counter

DS2423 (3)

LCD Screen

LCD (3) DS2408 (3)

Crypto

DS1977 (3)

Pressure

DS2406 (3) -- TAI8570

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💜 AVAILABILITY 💜

http://www.owfs.org

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💖 AUTHOR 💖

Paul Alfille (paul.alfille@gmail.com)

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and that's the whole page bestie, no cap. go sniff some packets responsibly 🫶✨

OWTAP Manpage — 2007 — OWTAP(1). that's the source, the version-vibe and the date, all wrapped up in a little bow for you 🎀 bye ily 💖