Интерактивная система просмотра системных руководств (man-ов)
>> sliplogin (8) ( FreeBSD man: Команды системного администрирования )
sliplogin (8) ( Linux man: Команды системного администрирования )
- attach a serial line network interface
utility is used to turn the terminal line on standard input (or
into a Serial Line IP
link to a remote host.
To do this, the program
searches the file
for an entry matching
(which defaults to the current login name if omitted).
If a matching entry is found, the line is configured appropriately
for slip (8-bit transparent i/o) and converted to
line discipline using the optional line discipline parameters.
The optional line discipline parameters consist of one or more of
which correspond respectively to
`use normal line discipline'
(no header compression),
`enable VJ header compression'
`throw away ICMP packets'
`auto enable VJ header compression'
(only if the remote end of the link also supports it).
Then a shell script is invoked to initialize the slip
interface with the appropriate local and remote
The usual initialization script is
but, if particular hosts need special initialization, the file
will be executed instead if it exists.
The script is invoked with the parameters
The unit number of the slip interface assigned to this line.
The speed of the line.
The arguments from the
entry, in order starting with
Only the super-user may attach a network interface.
The interface is
automatically detached when the other end hangs up or the
If the kernel slip
module has been configured for it, all routes through that interface will
also disappear at the same time.
If there is other processing a site
would like done on hangup, the file
is executed if it exists.
It is given the same arguments as the login script.
Format of /etc/sliphome/slip.hosts
Comments (lines starting with a `#') and blank lines (or started
with space) are ignored.
Other lines must start with a
but the remaining arguments can be whatever is appropriate for the
file that will be executed for that name.
Arguments are separated by white space and follow normal
quoting conventions (however,
cannot be quoted).
Usually, lines have the form
are the IP host names or addresses of the local and remote ends of the
slip line and
is the appropriate IP netmask.
These arguments are passed
are optional arguments used to configure the line.
An additional SLIP configuration file (if present) is
If particular hosts need different configurations, the file
will be parsed instead if it exists.
Format of /etc/sliphome/slip.slparms*
Comments (lines starting with a `#') and blank lines (or started with
space) are ignored.
This file contains from one to three numeric parameters separated with spaces,
Set SLIP "keep alive" timeout in seconds.
If FRAME_END is not received in
this amount of time,
closes the line and exits.
The default value is no timeout (zero).
Set SLIP "out fill" timeout in seconds.
It forces at least one FRAME_END
to be sent during this time period, which is necessary for the "keep alive"
timeout on the remote side.
The default value is no timeout (zero).
Set the SLIP unit number directly.
Use with caution, because no check is made
for two interfaces with same number.
By default sliplogin dynamically assigns the unit number.
If latter two parameters are omitted, they will not affect the
corresponding SLIP configuration.
If any of first two parameters is equal to zero, it will not affect
the corresponding SLIP configuration.
list of host login names and parameters.
script executed when a connection is made.
script executed when a connection is made by
script executed when a connection is lost.
script executed when a connection is lost by
extra parameters file.
extra parameters file for
/var/run/ ttyXn .if
contains the name of the network interface used by the sliplogin process on
/var/run/ slX .pid
contains the PID of the sliplogin process which is using interface
The normal use of
is to create a
entry for each legal, remote slip site with
as the shell for that entry.
Sfoo:ikhuy6:2010:1:slip line to foo:/tmp:/usr/sbin/sliplogin
(Our convention is to name the account used by remote host
Then an entry is added to
that looks like:
Sfoo `hostname` foo netmask
will be evaluated by
to the local host name and
is the local host IP netmask.
must be setuid to root and, while not a security hole, moral defectives
can use it to place terminal lines in an unusable state and/or deny
access to legitimate users of a remote slip line.
To prevent this,
is installed as user
and mode 4550 so that only members of group
The system administrator should make sure that all legitimate users
are a member of the correct group.
utility logs various information to the system log daemon,
with a facility code of
The messages are listed here, grouped by severity level.
ioctl (TCGETS): reason
to get the line parameters failed.
ioctl (TCSETS): reason
to set the line parameters failed.
file could not be opened.
access denied for user
No entry for
was found in