guessnet - guess which LAN a network interface is connected to
# Empty lines and lines starting with '#' are ignored. # Other lines contain: # <profile-name> <test-method> <parameters> # At home, look for a host with the given IP and MAC address home peer 192.168.1.1 00:01:02:03:04:05 # At the university, check for the presence of at least one # of the following hosts university peer 130.136.1.1 05:06:03:02:01:0A university peer 130.136.1.2 15:13:B3:A2:2F:CD # If the peer doesn't reply to ARP packets coming from 0.0.0.0 # then you can additionally specify a source address to use university peer 130.136.1.2 15:13:B3:A2:2F:CD 130.136.1.250 # For the work network use a custom script work command /usr/local/bin/check_work # Commands are executed by "sh -c" so shell syntax can be used john-irda command grep -q `cat ~enrico/john-irda-id` /proc/net/irda/discovery # Location name and interface name are exported in NAME and IFACE weirdnet command /usr/local/bin/weirddetect "$NAME" "$IFACE" # Profile "none" is selected if no network signal is detected # (i.e. there is no cable plugged into the socket) no-net missing-cable
Every non-comment line represents a test to perform. The first word in the line is the name that will be printed if the test succeeds. The second word is the test type. The remainder of the line contains parameters for the selected test; these vary depending on the test type.
ifupdown, Debian's standard network configuration system, permits one to define different "logical interfaces" (ifupdown's name for configuration profiles) and to choose among them when one configures a network interface. The choice can be delegated to an external "mapping" program. guessnet can be used as such a program if it is run in "ifupdown mode". guessnet runs in ifupdown mode if it is invoked as guessnet-ifupdown or if it is given the --ifupdown-mode option. In ifupdown mode guessnet reads test data directly from the logical interface definitions in /etc/network/interfaces rather than from a separate test description file. In ifupdown mode if names are passed to guessnet on its standard input then guessnet considers only those logical interface definitions; otherwise it considers them all. You can have ifupdown deliver data to guessnet's standard input using the map directive. See interfaces(5) for more information. In ifupdown mode options are selected by passing "<long-option-name>: <value>" on guessnet's standard input. This feature is provided because ifupdown cannot pass command line arguments to mapping scripts. If you prefer you can precede the test keyword in /etc/network/interfaces with the word guessnet. ifupdown does not allow two option lines in /etc/network/interfaces to start with the same word. To work around this limitation, multiple test (or guessnet) lines can have different numerals suffixed to their initial keywords (test1, test2, or guessnet1, guessnet2, and so on). Here's an example of an /etc/network/interfaces file that has been set up for guessnet:
auto lo eth0 iface lo inet loopback mapping eth0 script guessnet-ifupdown # Scan all logical interfaces # More options can be given here, such as: # map timeout: 10 # map verbose: true # map debug: true map default: none iface home inet static address 192.168.1.2 netmask 255.255.255.0 broadcast 192.168.1.255 gateway 192.168.1.1 # Lines for resolvconf (if you use it: see apt-cache show resolvconf) # dns-search casa # dns-nameservers 192.168.1.1 192.168.2.1 # Two tests, in case one of the two machines is down when we test test1 peer address 192.168.1.1 mac 00:01:02:03:04:05 test2 peer address 192.168.1.3 mac 00:01:02:03:04:06 iface work inet static address 10.1.1.42 netmask 255.255.255.0 broadcast 10.1.1.255 gateway 10.1.1.1 test command /usr/local/bin/check_work iface work2 inet static address 192.168.2.23 netmask 255.255.255.0 broadcast 192.168.2.255 gateway 192.168.2.1 # A source address has to be specified in case the peer # doesn't reply to ARP packets coming from 0.0.0.0 test peer address 192.168.2.1 mac 00:01:02:03:04:05 source 192.168.2.23 # If nothing else is found, try DHCP iface none inet dhcp
One can omit the MAC address, in which case guessnet only tests for the presence of a host with the specified IP address.
If the peer whose presence you want to test for refuses to reply to ARP packets coming from 0.0.0.0 then specify some source IP address from which the peer will accept requests.
Multiple peers can be specified (on multiple lines) but each peer must have a different IP address. This restriction may be eliminated in the future.
You can also omit the IP address and only use the MAC: that is useful to test for the existance of physical interfaces with changing IP addresses. This kind of scan uses an ICMP ping packet requires a source address in most cases, as hosts tend not to reply to pings coming from nowhere.
This feature allows guessnet to detect the case where there is no cable plugged into a network socket; in this case it makes no sense to go through other detection phases.
This test can be used in ifupdown mode too if a dummy logical interface is defined that includes the test missing-cable option. Bear in mind that when the cable is unplugged, ifupdown will consider the interface to be configured as this dummy logical interface. That is somewhat counterintuitive; one might prefer the interface to be deconfigured in that case. Unfortunately, guessnet is not currently able to tell ifup to refrain from configuring an interface. The problem can be solved, however, by means of the ifplugd(8) program.
Link beat detection is not supported on all network hardware. If the interface or its driver does not support link beat detection then this test does not succeed.
Location name and interface name are exported to the script via the NAME and IFACE environment variables.
For backward compatibility, script can be used instead of command.
Using this test requires that pppoe be installed on the system.
Blanks may be included in the ESSID. For example,
prof1 wireless essid My LANtests for an ESSID of "My LAN".
Note that the wireless test does not attempt to change these properties; it only examines them. This test is designed to work with programs such as waproamd which independently and dynamically manage the wireless network adapter to keep it associated to an access point.
Note that the wireless test is not yet implemented cleanly.
Note that if one of several tests terminates successfully then any other tests still running will be terminated with the KILL signal. Therefore, test programs should not need to do any special cleanup on exit.
Закладки на сайте Проследить за страницей |
Created 1996-2024 by Maxim Chirkov Добавить, Поддержать, Вебмастеру |