x29server(1M)

Requires Optional LAN/X.25 Software

NAME

x29server − X.29 PAD support server

SYNOPSIS

/etc/x29server [-l loglevel] [-w maxwrap]

DESCRIPTION

x29server provides PAD support for the X.25 /9000 link. The server (a user level process) accesses the X.25 level 3 via BSD sockets (programmatic interface). The server listens for call requests on any X.25 interface. When it receives a request from a PAD, x29server checks the calling address for access security. If valid, the call is accepted.

After call setup, x29server can receive two types of data: Normal terminal traffic, and PAD control messages. Terminal traffic is passed to pseudo-terminal drivers (see pty(7)). PAD control messages are processed by the server.

In the other direction, x29server passes data from pseudo-terminal drivers to X.25 level 3. It also processes requests by applications to alter tty parameters. These requests are mapped to X.3 parameters and sent to the remote PAD terminal.

The server is basically a pipe through which data is passed from X.25 to the pty, and vice versa. Terminal data is not modified.

Options

x29server recognizes the following options:

-l loglevel Set the logging level for log messages from x29server daemon to the logfile /usr/adm/x29/x29server/x29server.log. loglevel can be one of the following values:

0 No logging.

1 Minimum session logging and error logging.

2 PAD and X.25 error and warning logging plus 1.

3 Information and status logging plus 2.

Default is 1.

-w maxwrap Specify maximum size for server daemon logfile. Allowable range for maxwrap is 1-5000. Default is no maxwrap.

Configuration

System access security with x29server is provided by the /etc/x25/x29hosts file. A PAD -support server entry in /etc/x25/x29hosts is identified by the keyword pad_spt followed by information on access security, X.3 configuration, logging level, and reverse charging beginning with { and ending with }.

Incoming calls have their calling X.121 addresses compared to the remote_x121 address in all pad_spt entries in /etc/x25/x29hosts. If there is a match, the call is accepted. The legal character set for remote_x121 includes digits, from 0 through 9, the character F, the question mark ?, and the asterisk *.

Exact-address matching is provided with digits 0 through 9. The special-address FFFFFFFFFF matches to the null calling addresses. Wildcard-address matching is provided with ? (for any single digit) and * (for any address). If none of the remote_x121 addresses match the calling address, the virtual circuit is cleared immediately, not granting system access to the remote PAD user.

A typical PAD support server entry in /etc/x25/x29hosts resembles:

pad_spt{
    remote_x121     408555120801
    x3              hp_padsrvr
    reverse_charge disable
    logging         1
}

/etc/x25/x3config provides the initial X.3 parameters for the incoming connections from the PAD. The example above uses hp_padsrvr to specify the X.3 parameter set in the /etc/x25/x3config file. An typical hp_padsrvr set resembles:

hp_padsrvr {
    1        1        1
    2        1        1
    3       94      127
    4        0        0
    5        1        1
    6        5        5
    7       21       21
    8        0        0
    9        0        0
    10       0        0
    11      14       14
    12       1        1
    13       0        0
    14       0        0
    15       1        0
    16       8        8
    17      24       24
    18       0        0
    19       1        1
    20       0        0
    21       0        0
    22       0        0
}

x29server should be invoked after system access security and initial X.3 configurations are set up in /etc/x25/x29hosts and /etc/x25/x3config.

x29server can be started at system initialization time from /etc/netlinkrc. To ensure proper functionality, the X.25 subsystem should be initialized before invoking x29server. To start x29server, use the following command:

/etc/x29server

This starts the server background daemon which listens for all inbound PAD connections. If a PAD call is accepted, the server forks a child to handle the new connection. The parent continues to listen for incoming calls.

To stop the parent server, use the following command:

kill -9 process_id_of_server_daemon

Incoming calls are no longer accepted. To stop a child x29server, replaces the process ID of the server with the process ID of the child.

Note: A child process normally terminates at the end of a login session as a result of the logout process. The call is cleared and the child process exits. A child can also be terminated by an Invitation-to-Clear command from the remote PAD.

EXTERNAL INFLUENCES

x29server is implemented with native language support. The logging can be in a foreign language by setting the environment variable LANG to correct NLS values and putting corresponding message catalog files in /usr/lib/nls/ (see nlsinfo(1)).

DIAGNOSTICS

Diagnositic messages for x29server are written to logfiles in the directory /usr/adm/x29/x29server/. The x29server daemon writes messages to x29server.log to log incoming call events, as well as events concerning the daemon server process itself.

The child inherits its logging level from the daemon if no logging level is specified in /etc/x25/x29hosts for the incoming call address. Otherwise, the child’s logging level is that specified in /etc/x25/x29hosts. The child log filename is /usr/adm/x29/x29server/x29logxxxxx where xxxxx is the process ID of the child.

WARNINGS

PAD support security is provided by /etc/x25/x29hosts. If /etc/x25/x29hosts does not exist or is not accessible, all inbound calls are rejected.

x29server does not support permenant virtual circuits. x29server can only be used on switched virtual circuits.

x29server binds to all X.25 interfaces on the host system. It does not support binding to only a particular interface.

x29server does not support binary data transfer or block-mode applications.

x29server does not support X.28 local parameters on PAD.

x29server does not support fast-select facility features in X.25.

There must be one available pty configured on the system per desired PAD connection. The number of remote PAD users that x29server supports is determined by the number of available virtual circuits or psuedo-terminals, whichever is lower.

AUTHOR

x29server was developed by HP.

FILES

/etc/x25/x29hosts
/etc/x25/x3config

STANDARDS CONFORMANCE

The implementation of X.29 and X.3 protocols in x29server conforms to the 1984 CCITT standards.

Hewlett-Packard Company — HP-UX Release 9.0: August 1992

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