dhcpcd-run-hooks man page

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 /usr/libexec/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.
NOCARRIER
dhcpcd lost the carrier. The cable may have been unplugged or association to the wireless point lost.
INFORM | INFORM6
dhcpcd informed a DHCP server about it's address and obtained other configuration details.
BOUND | BOUND6
dhcpcd obtained a new lease from a DHCP server.
RENEW | RENEW6
dhcpcd renewed it's lease.
REBIND | REBIND6
dhcpcd has rebound to a new DHCP server.
REBOOT | REBOOT6
dhcpcd successfully requested a lease from a DHCP server.
DELEGATED6
dhcpcd assigned a delegated prefix to the interface.
IPV4LL
dhcpcd obtaind an IPV4LL address, or one was removed.
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 | EXPIRE6
dhcpcd's lease or state expired and it failed to obtain a new one.
NAK
dhcpcd received a NAK from the DHCP server. This should be treated as EXPIRE.
RECONFIGURE
dhcpcd has been instructed to reconfigure an interface.
ROUTERADVERT
dhcpcd has received an IPv6 Router Advertisement, or one has expired.
STOP | STOP6
dhcpcd stopped running on the interface.
STOPPED
dhcpcd has stopped entirely.
DEPARTED
The interface has been removed.
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.
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.

Environment

dhcpcd will clear the environment variables aside from $PATH and $RC_SVCNAME. The following variables will then be set, along with any protocol supplied ones.

$interface
the name of the interface.
$reason
as described above.
$pid
the pid of dhcpcd.
$ifcarrier
the link status of $interface: unknown, up or down.
$ifmetric
$interface preference, lower is better.
$ifwireless
1 if $interface is wireless, otherwise 0.
$ifflags
$interface flags.
$ifmtu
$interface MTU.
$ifssid
the name of the SSID the interface is connected to.
$interface_order
A list of interfaces, in order of preference.
$if_up
true if the interface is up, otherwise false.
$if_down
true if the interface is down, otherwise false.
$af_waiting
Address family waiting for, as defined in dhcpcd.conf(5).
$profile
the name of the profile selected from dhcpcd.conf(5).
$new_delegated_dhcp6_prefix
space separated list of delegated prefixes.

Files

When dhcpcd-run-hooks runs, it loads /etc/dhcpcd.enter-hook and any scripts found in /usr/libexec/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

dhcpcd will validate the content of each option against its encoding. For string, ascii, raw or binhex encoding it's up to the user to validate it for the intended purpose.

When used in a shell script, each variable must be quoted correctly.

Referenced By

dhcpcd(8), dhcpcd.conf(5).

June 27, 2016