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## 13. Uugetty for Dial-In (from the old Serial-HOWTO)

Be aware that you could use mgetty as a (better?) alternative to `uugetty`. `mgetty` is newer and more popular than uugetty. See Getty for a brief comparison of these 2 gettys.

## 13.1 Installing getty_ps

Since uugetty is part of getty_ps you'll first have to install getty_ps. If you don't have it, get the latest version from `metalab.unc.edu:/pub/Linux/system/serial`. In particular, if you want to use high speeds (57600 and 115200 bps), you must get version 2.0.7j or later. You must also have libc 5.x or greater.

By default, `getty_ps` will be configured to be Linux FSSTND (File System Standard) compliant, which means that the binaries will be in `/sbin`, and the config files will be named `/etc/conf.{uu}getty.ttyS` N. This is not apparent from the documentation! It will also expect lock files to go in `/var/lock`. Make sure you have the `/var/lock` directory.

If you don't want FSSTND compliance, binaries will go in `/etc`, config files will go in `/etc/default/{uu}getty.ttyS` N, and lock files will go in `/usr/spool/uucp`. I recommend doing things this way if you are using UUCP, because UUCP will have problems if you move the lock files to where it isn't looking for them.

`getty_ps` can also use `syslogd` to log messages. See the man pages for `syslogd(1)` and `syslog.conf(5)` for setting up `syslogd`, if you don't have it running already. Messages are logged with priority LOG_AUTH, errors use LOG_ERR, and debugging uses LOG_DEBUG. If you don't want to use `syslogd` you can edit `tune.h` in the `getty_ps` source files to use a log file for messages instead, namely `/var/adm/getty.log` by default.

Decide on if you want FSSTND compliance and syslog capability. You can also choose a combination of the two. Edit the `Makefile`, `tune.h` and `config.h` to reflect your decisions. Then compile and install according to the instructions included with the package.

## 13.2 Setting up uugetty

With `uugetty` you may dial out with your modem while `uugetty` is watching the port for logins. `uugetty` does important lock file checking. Update `/etc/gettydefs` to include an entry for your modem. For help with the meaning of the entries that you put into `/etc/gettydefs`, see the "serial_suite" collected by Vern Hoxie. How to get it is in section See About getty_em. When you are done editing `/etc/gettydefs`, you can verify that the syntax is correct by doing:

> `

>     linux# getty -c /etc/gettydefs

> `

### Modern Modems

If you have a 9600 bps or faster modem with data compression, you can lock your serial port to one speed. For example:

> `

>     # 115200 fixed speed
>     F115200# B115200 CS8 # B115200 SANE -ISTRIP HUPCL #@S @L @B login: #F115200

> `

If you have your modem set up to do RTS/CTS hardware flow control, you can add `CRTSCTS` to the entries:

> `

>     # 115200 fixed speed with hardware flow control
>     F115200# B115200 CS8 CRTSCTS # B115200 SANE -ISTRIP HUPCL CRTSCTS #@S @L @B login: #F115200

> `

### Old slow modems

If you have a slow modem (under 9600 bps) Then, instead of one line for a single speed, your need several lines to try a number of speeds. Note that these lines are linked to each other by the last "word" in the line such as #4800. Blank lines are needed between each entry. Are the higher modem-to-serial_port speeds in this example really needed for a slow modem ?? The uugetty documentation shows them so I'm not yet deleting them.

> `

>     # Modem entries
>     115200# B115200 CS8 # B115200 SANE -ISTRIP HUPCL #@S @L @B login: #57600

>     57600# B57600 CS8 # B57600 SANE -ISTRIP HUPCL #@S @L @B login: #38400

>     38400# B38400 CS8 # B38400 SANE -ISTRIP HUPCL #@S @L @B login: #19200

>     19200# B19200 CS8 # B19200 SANE -ISTRIP HUPCL #@S @L @B login: #9600

>     9600# B9600 CS8 # B9600 SANE -ISTRIP HUPCL #@S @L @B login: #4800

>     4800# B4800 CS8 # B4800 SANE -ISTRIP HUPCL #@S @L @B login: #2400

>     2400# B2400 CS8 # B2400 SANE -ISTRIP HUPCL #@S @L @B login: #1200

>     1200# B1200 CS8 # B1200 SANE -ISTRIP HUPCL #@S @L @B login: #115200

> `

### Login Banner

If you want, you can make `uugetty` print interesting things in the login banner. In Greg's examples, he has the system name, the serial line, and the current bps rate. You can add other things:

> `

>            @B    The current (evaluated at the time the @B is seen) bps rate.
>            @D    The current date, in MM/DD/YY.
>            @L    The serial line to which uugetty is attached.
>            @S    The system name.
>            @T    The current time, in HH:MM:SS (24-hour).
>            @U    The number of currently signed-on users.  This is  a
>                  count of the number of entries in the /etc/utmp file
>                  that have a non-null ut_name field.
>            @V    The value of VERSION, as given in the defaults file.
>            To display a single '@' character, use either '\@' or '@@'.

> `

## 13.3 Customizing uugetty

There are lots of parameters you can tweak for each port you have. These are implemented in separate config files for each port. The file `/etc/conf.uugetty` will be used by all instances of `uugetty`, and `/etc/conf.uugetty.ttyS` N will only be used by that one port. Sample default config files can be found with the `getty_ps` source files, which come with most Linux distributions. Due to space concerns, they are not listed here. Note that if you are using older versions of `uugetty` (older than 2.0.7e), or aren't using FSSTND, then the default file will be `/etc/default/uugetty.ttyS` N. Greg's `/etc/conf.uugetty.ttyS3` looked like this:

> `

>     # sample uugetty configuration file for a Hayes compatible modem to allow
>     # incoming modem connections
>     #
>     # line to initialize
>     INITLINE=ttyS3
>     # timeout to disconnect if idle...
>     TIMEOUT=60
>     # modem initialization string...
>     # format: <expect> <send> ... (chat sequence)
>     INIT="" AT\r OK\r\n
>     WAITFOR=RING
>     CONNECT="" ATA\r CONNECT\s\A
>     # this line sets the time to delay before sending the login banner
>     DELAY=1
>     #DEBUG=010

> `

Add the following line to your `/etc/inittab`, so that `uugetty` is run on your serial port, substituting in the correct information for your environment - run-levels (2345 or 345, etc.) config file location, port, speed, and default terminal type:

> `

>     S3:2345:respawn:/sbin/uugetty -d /etc/default/uugetty.ttyS3 ttyS3 F115200 vt100

> `

Restart `init`:

> `

>     linux# init q

> `

For the speed parameter in your `/etc/inittab`, you want to use the highest bps rate that your modem supports.

Now Linux will be watching your serial port for connections. Dial in from another machine and login to you Linux system.

`uugetty` has a lot more options, see the man page for `uugetty)` (often just called `getty`) for a full description. Among other things there is a scheduling feature, and a ringback feature.

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