BBS24x7

A BBS on-hook tool

Usage

See user guide

Design

1. Unattended login and user information

Use Tcl Expect script to login and rest on a specific discussion board. An user information file needs to provide as input. The format is quadruple strings for each line, which defines a user login:

<user>      <password>      <loginstr>      <default_board>

where each field is optional.

If is set, it will be used as the SSH connection(ssh <loginstr>). It can be normal user@host format like

foo@bbs.bar.net

or

host alias set for the Host field in ~/.ssh/config like bar.foo in the below example

Host bar.foo                 <-----
    Hostname bbs.bar.net
    User foo

This SSH configuration way can provide more control of login. For example, if you want to connect behind a forwar proxy

Host bar.foo
    Hostname bbs.bar.net
    User foo
    ProxyCommand `which ncat` --proxy-type socks5 --proxy 127.0.0.1:1080 %h %p

<board_name> specifies which BBS board the cursor will rest in after login. This field is optional and the default board set in the corresponding *.tcl file will be used if omitted.

2. Keep alive when idle

The Tcl Expect script will send \0 to BBS at regular intervals of every 2 minutes to avoid connection drop by the server.

3. Give control back to user

When a series of commands are done after login, the script process will be left in the interactive mode, users can visit the BBS as usual.

4. Managed by Tmux

Each user session is created in a single pane window of a Tmux session for a BBS. So n different user logins, n Tmux windows in 1 Tmux session. Users can freely attach or detach the Tmux session anytime, from one virtual console or another, from local or remote, which is very flexible.

e.g. To attach to a Tmux session called smth on remote server rpi-lan

ssh rpi-lan -t tmux a -t smth

5. Multiple session support

6. Cron and watchdog

Put the tmux launch script in cron table, and schedule it to run periodically like every hour. Every time when the script starts, it will examine whether the BBS session exists and all login connections are alive. If not, it will recover the broken Tmux session. If userinfo file is updated and newer than the timestamp when the session was created, the session will get killed and recreated.

Docker support

See docker guide and arg6/bbs24x7 on dockerhub.

Requirements

• SSH/Telnet client
• Tcl/Expect and Tcllib
• Luit (2.0+)
• Tmux

NOTE: Luit is used to translate character set and solve the "garbled text" problem met when visit east Asian BBS. On Debian 11, the default luit(1.1.1) installed as a part of x11-utils is too old, may cause unexpected issues like segmentation fault. Build and install from luit 2.0 source. On Debian 12, the default luit installed is v2.0, so no need to build from source.