NAME¶
dhcpcd-run-hooks —
DHCP client
configuration script
DESCRIPTION¶
dhcpcd-run-hooks is used by
dhcpcd(8) to run
any system and user defined hook scripts. System hook scripts are found in
/lib/dhcpcd/dhcpcd-hooks and the user defined hooks are
/etc/dhcpcd.enter-hook. and
/etc/dhcpcd.exit-hook. The default install supplies hook
scripts for configuring
/etc/resolv.conf and the hostname.
Your distribution may have included other hook scripts to say configure ntp or
ypbind. A test hook is also supplied that simply echos the dhcp variables to
the console from DISCOVER message.
Each time
dhcpcd-run-hooks is invoked,
$interface
is set to the interface that
dhcpcd is run on and
$reason
is to
the reason why
dhcpcd-run-hooks was invoked. DHCP
information to be configured is held in variables starting with the word new_
and old DHCP information to be removed is held in variables starting with the
word old_.
dhcpcd can display the full list of variables it
knows how about by using the
-V,
--variables argument.
Here's a list of reasons why
dhcpcd-run-hooks could be
invoked:
PREINIT
- dhcpcd is starting up and any pre-initialisation should be
done.
CARRIER
- dhcpcd has detected the carrier is up. This is generally
just a notification and no action need be taken.
INFORM
- dhcpcd informed a DHCP server about it's address and
obtained other configuration details.
BOUND
- dhcpcd obtained a new lease from a DHCP server.
RENEW
- dhcpcd renewed it's lease.
REBIND
- dhcpcd has rebound to a new DHCP server.
REBOOT
- dhcpcd successfully requested a lease from a DHCP
server.
IPV4LL
- dhcpcd failed to contact any DHCP servers but did obtain an
IPV4LL address.
STATIC
- dhcpcd has been configured with a static configuration
which has not been obtained from a DHCP server.
3RDPARTY
- dhcpcd is monitoring the interface for a 3rd party to give
it an IP address.
TIMEOUT
- dhcpcd failed to contact any DHCP servers but was able to
use an old lease.
EXPIRE
- dhcpcd's lease or state expired and it failed to obtain a
new one.
RELEASE
- dhcpcd's lease was released back to the DHCP server for
re-use.
NAK
- dhcpcd received a NAK from the DHCP server. This should be
treated as EXPIRE.
NOCARRIER
- dhcpcd lost the carrier. The cable may have been unplugged
or association to the wireless point lost.
FAIL
- dhcpcd failed to operate on the interface. This normally
happens when dhcpcd does not support the raw interface, which means it
cannot work as a DHCP or ZeroConf client. Static configuration and DHCP
INFORM is still allowed.
STOP
- dhcpcd stopped running on the interface.
DUMP
- dhcpcd has been asked to dump the last lease for the
interface.
TEST
- dhcpcd received an OFFER from a DHCP server but will not
configure the interface. This is primarily used to test the variables are
filled correctly for the script to process them.
ROUTERADVERT
- dhcpcd has received an IPv6 Router Advertisment, or one has
expired.
FILES¶
When
dhcpcd-run-hooks runs, it loads
/etc/dhcpcd.enter-hook and any scripts found in
/lib/dhcpcd/dhcpcd-hooks in a lexical order and then finally
/etc/dhcpcd.exit-hook
SEE ALSO¶
dhcpcd(8)
AUTHORS¶
Roy Marples ⟨roy@marples.name⟩
BUGS¶
Please report them to
http://roy.marples.name/projects/dhcpcd
SECURITY CONSIDERATIONS¶
Little validation of DHCP options is done in dhcpcd itself. Instead, it is up to
the hooks to handle any validation needed. To this end, some helper functions
are provided, such as valid_domainname as used by the
20-resolv.conf hook to ensure that the hostname is not set
to an invalid value. valid_path is also provided, but is currently unused by a
stock hook script.