NAME¶
detect.conf — provides the configuration for detection of locations for
whereami.
DESCRIPTION¶
Syntax¶
The
detect.conf file specifies the tests that allow
whereami to
figure out where it is. The environment of such tests can be manipulated using
the 'set' command. Tests can be performed conditionally upon the results of
other tests using "if ... fi" constructs.
Comments are lines starting with the `#' character. Leading whitespace is
ignored on all lines, including comment lines.
Internal Commands¶
The syntax of this file is fairly straightforward. Tests are specified thus:
- testname parameter
locations
- The command testname is run with the single
parameter (which may be split internally). If the return value is
0, the test is considered `successful' and the locations are
considered `discovered'.
-
- locations is a list of comma separated identifiers,
each one matching the regexp `` [[:alnum:]._-]+''.
-
- On success, processing will skip all non-`always'
statements up to the next `if' or `fi' keyword, whichever is earlier.
- if location statements ... [elif
location statements ...]... [else statements ...]
fi
- If the location is in the list of locations
discovered so far, then the statements in the `if' branch will be
processed. Otherwise, if present, the statements in either the `elif' or
the `else' (as appropriate) branch will be processed.
-
- Note that nesting of `if' blocks is not supported at this
time.
- always testname parameter
locations
- A test preceded by the word `always' is not skipped unless
it is within the inactive branch of an `if' clause.
- set variable value
- The environment variable is defined as value
for all subsequent test scripts and in the shell script eventually
constructed by whereami.
- at locations
- The locations will be added to the
"discovered" list.
- notat locations
- The locations will be removed from the
"discovered" list.
- echo quoted text string
- The "quoted text string" will be displayed
to the user on stdout.
The
parameter and
locations may be lists, with a comma
(",") used to separate multiple values.
Tests¶
Any program may be used as a test so long as it accepts a single parameter and
returns zero on success and non-zero on failure.
If a parameter of the test script must contain a space, it parameter will need
to be quoted.
A number of tests are included in the whereami package.
- testdhcp [interface,]pattern
- Tests for the assignment by DHCP of an IP address matching
the specified address pattern. If not specified, the
interface defaults to `eth0'.
-
- Note that the first execution of this test during a
particular run of whereami induces a DHCP request on the specified
interface.
- testmii interface
- Checks for the presence of a link on interface using
the mii-tool utility. If a link is not found then the interface
will be 'down'ed to limit side-effects on other detection later.
- testpppoe interface
- Tries to start a PPPoE connection on the specified
interface. Success is returned if the connection starts.
- testarp
interface,mac_address,ip_address
- Performs an arping (Debian package: iputils-arping)
to look for the specified mac_address and ip_address
combination on the network connected to interface.
- testping
[interface,]ip_to_ping,ip_to_use
- Uses the fping program to perform a fast ping to
look for the presence of a particular host on the local network.
- testpci pattern
- Searches for the pattern in the output of lspci
-v.
-
- This enables checking for specific hardware, such as a
particular type of docking station.
- testmodule pattern
- Searches for the pattern in the output of
lsmod.
-
- This is useful for checking for the presence of a
particular PCMCIA card, or possibly a particular kernel
configuration.
- testap [interface,]scan
- testap pattern[,WEP Key]
- testap [interface,]pattern,WEP
Key
- The pattern is a regexp (egrep regexp) used to match
AP essids: when this regexp matches a detected essid the test is
considered succesfull.
-
- This check does not require encryption to be set up to
work, although it may not find stealthier equipment - use testssid in that
case.
-
- The 'scan' option will cause a new scan, and the first call
should have this option set. Subsequent calls will use the results of that
first scan, reducing the overhead for those busy people who connect to
many WLANs!
-
- If a WEP key is supplied, and a pattern match is found, the
key will be assigned to that interface so that subsequent tests should
work correctly.
-
- When using the WEP key you may in some cases desire
to pass additional parameters to iwconfig. These parameters may be passed
preceding the WEP key and separated with an underscore. For example
"restricted_0123-4567-89" will force the card to be configured
to insist on 'restricted' mode at the same time as the key was set.
- testappassive [interface,]scan
- testappassive pattern
- testap [interface,]pattern
- Checks whether the specified AP is present, passively. This
check does not alter the essid on the interface, or set the WEP key like
the testap test. It just uses iwlist interface scan. This is useful
where you have another external script that sets up all the wifi settings,
and running whereami a second time destroys the running wifi connection,
as can happen on boot where networking is intialised before whereami
starting in run level 2.
-
- The 'scan' option will cause a new scan, and the first call
should have this option set. Subsequent calls will use the results of that
first scan, reducing the overhead for those busy people who connect to
many WLANs!
- testprocsys
proc-or-sys-path,egrep-pattern
- Checks the specified /sys or /proc file to see if it
contains the given egrep expression. Non-existent file results in failure,
as well as a failed match. Useful for those interfaces that require to
hotplug to be configured so that firmware can be loaded. On machine
shutdown, hotplug can be disabled before networking interfaces, and this
enables whereami to function correctly in those circumstances.
- testssid ssid[,key]
- Checks whether the wireless interface is in range of the
specified ssid, using the key if supplied. The key should be
formatted as for iwconfig. What works for me looks like
da18babe100ea4beadb74324bc ("128" bits) or fe3d1b3ed7 (40
bits).
-
- This script will also respond to a TIMEOUT variable which
is set before it is called, but waiting for $TIMEOUT seconds for the
network to settle (default 2).
-
- This is useful for checking which wireless LAN is in
range.
- testreceived [interface]
- Checks whether the interface in question has
received any bytes.
-
- This is useful for checking which network interface is
actually connected to a network.
EXAMPLES¶
The following examples show simple setups, firstly for a wired only
configuration, and secondly for a mixed wireless and wired setup.
A Simple Wired DHCP Configuration
# Simple wired DHCP with two networks
default undocked
testmii eth0 lan
if lan
set INTERFACE eth0
testdhcp restart dhcp
fi
if dhcp
testdhcp '192.168.1.1' home
testdhcp '152.81.*.*' univ
fi
A Wired and Wireless Configuration
# Configuration including both wired and wireless networks
default undocked
testmii eth0 lan
# We prefer a wired network, but if we aren't wired
# we will look for a WLAN.
if lan
set INTERFACE eth0
testdhcp restart dhcp
else
set INTERFACE wlan0
testap scan wlan
fi
# Try WLANs until it we find one that works
if wlan
testap homessid,dead-beef-dead-beef-dead-beef-be wlhome_enc
testap homessid wlhome_open
fi
# If we are at a WLAN we should have the AP setup now
if wlan
# WLAN almost always will be DHCP
testdhcp restart dhcp
fi
# Now identify the actual network
if dhcp
testdhcp '192.168.1.1' home
testdhcp '192.168.1.2' wlhomeip
testdhcp '152.81.*.*' work
fi
SEE ALSO¶
whereami(8),
whereami.conf(5)
Further documentation is available in the /usr/share/doc/whereami directory.
FILES¶
- /etc/whereami/detect.conf
- The file we are talking about in this here manpage.
- /etc/whereami/whereami.conf
- Defines the actions performed as a result of entering,
leaving, or remaining at a particular location.
LIMITATIONS¶
The `if' syntax does not support nesting.
AUTHOR¶
This manual page was written by Andrew McMillan <awm@debian.org> for the
Debian GNU/Linux system (but may be used by others). Permission is
granted to copy, distribute and/or modify this document under the terms of the
GPL version 2.