arm (anonymizing relay monitor) - Terminal status monitor for Tor relays. Developed by Damian Johnson (www.atagar.com - [email protected]) All code under the GPL v3 (http://www.gnu.org/licenses/gpl.html) Project page: www.atagar.com/arm

Description: Command line application for monitoring Tor, providing real time status information such as the current configuration, bandwidth usage, message log, connections, etc. This uses a curses interface much like 'top' does for system usage. The application is intended for command-line aficionados, ssh connections, and anyone with a tty terminal for checking their relay's status. Releases should be stable so if you manage to make it crash (or have a feature request) then please let me know!

The project was originally proposed in 2008 by Jacob and Karsten: http://archives.seul.org/or/dev/Jan-2008/msg00005.html

An interview by Brenno Winter discussing the project is available at: http://www.atagar.com/arm/HFM_INT_0001.mp3

Requirements: Python 2.5 TorCtl (this is included with arm) Tor is running with an available control port. This means either... ... starting Tor with '--controlport ' ... or including 'ControlPort ' in your torrc

It's also highly suggested for the control port to require authentication. This can be done either with a cookie or password:

• Cookie Authentication - Controllers authenticate to Tor by providing the contents of the control_auth_cookie file. To set this up...

  • add "CookieAuthentication 1" to your torrc
  • either restart Tor or run "pkill -sighup tor"
  • this method of authentication is automatically handled by arm, so you can still start arm as you normally would

• Password Authentication - Attaching to the control port requires a password. To set this up...

  • run "tor --hash-password "
  • add "HashedControlPassword " to your torrc
  • either restart Tor or run "pkill -sighup tor"
  • when starting up arm will prompt you for this password

For full functionality this also needs:

• To be ran with the same user as tor to avoid permission issues with connection resolution and reading the torrc.

• Common *nix commands including:

  • ps
  • a method of connection resolution (any of the following):
    • sockstat
    • netstat
    • ss
    • lsof
    • procstat
  • tail
  • pwdx
  • ulimit
  • pgrep or pidof
  • host (if dns lookups are enabled)

This is started via 'arm' (use the '--help' argument for usage).

FAQ:

Why is it called 'arm'?

Simple - because it makes the command short and memorable. Terminal applications need to be easy to type (like 'top', 'ssh', etc), and anything longer is just begging command-line aficionados to alias it down. I chose the meaning of the acronym ('anonymizing relay monitor') afterward.

If you're listing connections then what about exit nodes? Won't this include people's traffic?

No. Potential client and exit connections are specifically scrubbed of identifying information. Be aware that it's highly discouraged for relay operators to fetch this data, so please don't.

Is it harmful to share the information provided by arm?

Not really, but it's discouraged. The original plan for arm included a special emphasis that it wouldn't log any data. The reason is that if a large number of relay operators published the details of their connections then correlation attacks could break Tor user's anonymity. Just show some moderation in what you share and it should be fine.

Is there any chance that arm will leak data?

No. Arm is a completely passive listener, fetching all information from either Tor or the local system.

When arm starts it gives "Unable to resolve tor pid, abandoning connection listing"... why?

If you're running multiple instances of Tor then arm needs to figure out which pid belongs to the open control port. If it's running as a different user (such as being in a chroot jail) then it's probably failing due to permission issues. Arm still runs, just no connection listing or ps stats.

The bandwidth graph showing up

Some terminals, most notably screen sessions on Gentoo, appear to have a bug where highlighted spaces aren't rendered. A reported workaround is to set: TERM="rxvt-unicode"

When I press enter in the connection panel to get details some of the information is either missing or outdated. Why is this?

There are two sources of information about Tor relays: their consensus and descriptor entries.

The consensus entry is provided on an hourly basis by the Tor directory authorities (special relays that keep track of all the relays in the network). The consensus has information like the nickname, flags, and in newer Tor versions a summarized exit policy.

The descriptor entry, however, is published by the relays themselves and has information like their platform, contact information, family, public keys, exit policy, etc. These are much larger than the consensus entries and don't change unless the relay changes their configuration.

Everyone in the Tor network (both relays and users) need the consensus entries to operate. However, only users (not relays) need the descriptor entries.

Tor will fetch both the consensus and descriptors for all of the currently active relays when it first starts. But to save bandwidth only the consensus entries are updated after this unless... a. 'FetchUselessDescriptors 1' is set in your torrc b. the directory service is provided ('DirPort' defined) c. you use Tor as a client

This means that some of the information on the connection page (like the platform and contact information) might be missing or stale due to missing descriptors. This isn't important to most users, but if you need this information then this is simple to fix with the above.

Layout:

./ arm - startup script install - installation script

arm.1 - man page armrc.sample - example arm configuration file with defaults ChangeLog - revision history LICENSE - copy of the gpl v3 README - um... guess you figured this one out setup.py - distutils installation script for arm

src/ init.py starter.py - parses and validates commandline parameters prereq.py - checks python version and for required packages version.py - version and last modified information test.py - method for starting tests and demos settings.cfg - attributes loaded for parsing tor related data torConfigDesc.txt - fallback descriptions of Tor's configuration options uninstall - removal script

cli/
  graphing/
    __init__.py
    graphPanel.py     - (page 1) presents graphs for data instances
    bandwidthStats.py - tracks tor bandwidth usage
    psStats.py        - tracks system information (such as cpu/memory usage)
    connStats.py      - tracks number of tor connections

  connections/
    __init__.py
    connPanel.py       - (page 2) lists the active tor connections
    circEntry.py       - circuit entries in the connection panel
    connEntry.py       - individual connections to or from the system
    countPopup.py      - displays client locale or exit port counts
    descriptorPopup.py - displays raw descriptor and consensus entries
    entries.py         - common parent for connPanel display entries

  menu/
    __init__.py
    menu.py           - provides an interactive menu
    item.py           - individual items within the menu
    actions.py        - handlers for menu selections

  __init__.py
  controller.py          - main display loop, handling input and layout
  headerPanel.py         - top of all pages, providing general information
  popups.py              - toolkit providing display popups
  wizard.py              - provides the relay setup wizard

  logPanel.py            - (page 1) displays tor, arm, and torctl events
  configPanel.py         - (page 3) editor panel for the tor configuration
  torrcPanel.py          - (page 4) displays torrc and validation
  interpretorPanel.py    - (page 5) interpretor for control port access

util/
  __init__.py
  conf.py        - loading and persistence for user configuration
  connections.py - service providing periodic connection lookups
  enum.py        - enumerations for ordered collections
  hostnames.py   - service providing nonblocking reverse dns lookups
  log.py         - aggregator for application events
  panel.py       - wrapper for safely working with curses subwindows
  procTools.py   - queries process & system information from /proc contents
  procName.py    - renames our process to a friendlier name
  sysTools.py    - helper for system calls, providing client side caching
  textInput.py   - expands the capabilities of text input fields
  torConfig.py   - functions for working with the torrc and config options
  torInterpretor.py - provides a shell around raw control port access
  torTools.py    - TorCtl wrapper, providing caching and derived information
  uiTools.py     - helper functions for presenting the user interface