NAME
dp — dedicated ports file used by DDFA software and Telnet port identification feature
DESCRIPTION
The
dp
file has two uses:
- Datacommunications and Terminal Controller Device File Access
The
dp
file is used by the
Datacommunications and Terminal Controller
Device File Access
(DDFA)
software to allow terminal server ports
to be programmatically accessed from
HP-UX
applications in the same way as devices connected directly to the
HP-UX
system.
It contains a one-line entry for each configured
terminal server port.
The
dp
file contains the information the
DDFA
software needs to set up and manage an outbound connection to a specified
terminal server port.
The file is parsed by the Dedicated Port Parser
(dpp)
which spawns an Outbound Connection Daemon
(ocd)
for each outbound connection specified in the file.
- Telnet Port Identification
The
dp
file is used by the
HP-UX
telnet daemon
(telnetd)
to identify the calling port and board
of a telnet connection from an
HP
Datacommunications and Terminal Controller
(DTC).
At connection time,
the host negotiates the telnet environment option and the
DTC
replies with the port and board number of the connecting device.
Telnetd
maps the port and board numbers to the well-known name for the device,
which has previously been configured in the
dp
file.
Datacommunications and Terminal Controller Device File Access
For outbound connections, an entry should have the following format:
dtc_name board/port pseudonym config_file log_level
The exact details of each field are given below.
Telnet Port Identification
To configure the
dp
file for using the Telnet port identification feature,
the default file
/usr/examples/ddfa/dp
should be copied to a new file
and the copy configured with the appropriate values
for the incoming connections.
The recommended procedure is to create a directory
to hold the
dp
file and the modified port configuration files.
An entry for this purpose should have the following format:
dtc_name board/port pseudonym
The exact details of each field are given below.
Configuration Information
There are three ways to specify a
terminal server port:
Explicitly specify its
IP
address.
Specify the node name or the
IP
address of the
DTC
then specify the board and port.
Specify the node name or the
IP
address of the
terminal server and the
TCP
port service address of the port.
Comments in the
dp
file can be appended by starting them with a
#
character.
Everything after the
#
is ignored by the parser.
Fields in the
dp
file are separated by space characters.
See
ddfa(7)
for more information on how to configure the
DDFA
software.
The fields of an entry of the
dp
file are as follows:
- dtc_name
This field is the node name or the
IP
address of the
terminal server being accessed or the
IP
address of the port on the terminal server.
A node name must be defined in a name database.
- board/port
This field contains the terminal server port address with the parts
separated by the
/
character.
It is not necessary to pad the values with leading zeros.
The port address is not checked by
dpp,
but is checked by
ocd.
Valid values are 0 through 7 for
board,
and 0 through 31 for
port
(these restrictions do not apply if the
TCP
port service address is specified instead).
If the
dtc_name
field explicitly defines the node name or the IP address of the terminal server
port, the value in the
board/port
field must be
xx/xx
(use
X
or
x).
If the field is of the form
xx/n
where
n
is a decimal number,
n
is assumed to be the
TCP
port service address and it is used
when the connection is established.
- pseudonym
This field is the absolute path of the device file
known to the system and the end-user application.
The device file name portion of the path name is limited to 14 characters.
- pc_file_path
This field is the path to a port configuration file
which contains the configuration information for the
terminal server port.
This field is mandatory for outbound connections as
dpp
uses the presence of this field
as its flag to spawn a daemon for the entry.
- log_level
This field is the logging level for the particular
ocd
and it determines the severity of messages sent to
/var/adm/syslog.
The logging levels (and how they relate to system logging levels) are as
follows:
- 0
Log only LOG_CRIT messages.
- 1
Log only LOG_CRIT and LOG_ERR messages.
- 2
Log only LOG_CRIT, LOG_ERR, and LOG_WARNING messages.
- 3
Log all messages.
It is optional and may only be specified for outbound connections.
If it is omitted, the logging level is set to 1.
EXAMPLES
The following examples illustrate file entry syntax.
A printer is connected to port 1 of board 3 of a
DTC
with the
IP
address 11.234.87.123.
The device attached to the port can be accessed with the
HP-UX
spooler by using the device file
/dev/telnet/lp1_ocd.
11.234.87.123 03/01 /dev/telnet/lp1_ocd /usr/examples/ddfa/pcf
A printer is connected to a
terminal server port with
IP
address 11.234.87.124.
The
board/port
field contains
xx/xx.
The device attached to the port can be accessed with the
HP-UX
spooler by using the device file
/dev/telnet/lp2_ocd.
11.234.87.124 xx/xx /dev/telnet/lp2_ocd /usr/examples/ddfa/pcf
A printer is connected to a port accessed with
TCP
port service address 5001 of a terminal server
with the
IP
address 11.234.87.215.
The device attached to the port can be accessed with the
HP-UX
spooler by using the device file
/dev/telnet/lp3_ocd.
11.234.87.215 xx/5001 /dev/telnet/lp3_ocd /usr/examples/ddfa/pcf
A terminal is connected to port 1 of board 2 of a DTC
with the
IP
address 11.234.87.215 and wishes to use Telnet port identification.
11.234.87.215 02/01 /dev/telnet/tm02
WARNINGS
In order to ensure that commands (such as
ps)
display the correct device file name (that is, the
pseudonym),
all pseudonyms should be placed into the directory
/dev/telnet.
If pseudonyms are not specified for placement in this directory,
the correct display of device file names with many commands is not guaranteed.
In addition, in order to ensure that commands (such as
w,
passwd,
finger,
and
wall)
work correctly,
each pseudonym must be unique in its first 17 characters
(including the directory prefix
/dev/telnet/).
If pseudonyms are not unique in their first 17 characters,
the correct functioning of many commands is not guaranteed.
FILES
/usr/sbin/dpp
/usr/sbin/ocd
/usr/sbin/ocdebug
/var/adm/dpp_login.bin
/var/adm/utmp.dfa
/usr/examples/ddfa/dp
/usr/examples/ddfa/pcf
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