IMPORT(4) IMPORT(4)
NAME
import - import a name space from a remote system
SYNOPSIS
import [ options ] system file [ mountpoint ]
import -B [ options ] mountpoint [ cmd [ args ... ] ]
DESCRIPTION
This tool is deprecated and has been replaced by rimport
(see rcpu(1)).
Import allows an arbitrary file on a remote system to be
imported into the local name space. Usually file is a
directory, so the complete file tree under the directory is
made available.
A process is started on the remote machine, with authority
of the user of import, to perform work for the local machine
using the exportfs(4) service. The default port used is TCP
17007. If mountpoint is omitted import uses the name of the
remote file as the local mount point.
The options are:
-a -b -c -C Control the construction of union directories,
as in mount and bind(1). Only valid when file is
a directory.
-A Skip the authentication protocol. This is use-
ful for connecting to foreign systems like
Inferno.
-z Bypass the initial protocol request for which
remote tree to serve. This is necessary when
the remote exportfs(4) is running with the -r or
-S options which pre-select a file tree to
serve. The exception is if both sides are oper-
ating in the -B backwards mode.
-B Run in ``backwards'' mode, described below.
-E enc Push an encryption protocol on its network con-
nection. The supported protocols are clear (the
default, no protocol) and ssl. There are plans
to make tls available.
-e 'enc hash'
Specify the encryption and hash algorithms to
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IMPORT(4) IMPORT(4)
use for encrypting and authenticating the wire
traffic (see ssl(3)). The defaults are rc4_256
and sha1.
-k keypattern
Use keypattern to select a key to authenticate
to the remote side (see auth(2)).
-p Push the aan(8) filter onto the connection to
protect against temporary network outages.
-n Specify announce string for aan(8) filter when
run in ``backwards'' mode.
-s name Post the connection's mountable file descriptor
as /srv/name.
The -B option runs import in ``backwards'' mode. In this
mode, import runs a p9any authentication (as server) over
its file descriptor 0 (expected to be an incoming network
connection from exportfs -B), mounts the connection onto
mntpt, and optionally runs cmd args.
EXAMPLES
Assume a machine kremvax that has IP interfaces for the com-
pany intranet and the global internet mounted on /net and
/net.alt respectively. Any machine inside the company can
get telnet out to the global internet using:
import -a kremvax /net.alt
telnet /net.alt/tcp!ucbvax
Suppose that the machine moscvax has access to a private
file server containing public web pages that need to be
served by the less-trusted server webvax. Webvax runs the
following listener (see listen(8)) on TCP port 999:
#!/bin/rc
import -B -s rowebfs /usr/web /bin/restarthttpd
When moscvax boots, it runs
exportfs -R -r /usr/web -B tcp!webvax!999
to serve a read-only copy of /usr/web to webvax. When
webvax gets the call, import mounts the served tree onto its
own /usr/web and then runs /bin/restarthttpd to restart
httpd(8).
SOURCE
/sys/src/cmd/import.c
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SEE ALSO
rcpu(1), bind(1), ssl(3), exportfs(4), srv(4), aan(8),
listen(8), cs in ndb(8)
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