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.

       The hooks scripts are loaded into the current shell rather than executed  in  their  own  process.   This
       allows  each  hook  script,  such as /etc/dhcpcd.enter-hook to customise environment variables or provide
       alternative functions to hooks further down the chain.  As such, using the shell builtins exit,  exec  or
       similar will cause dhcpcd-run-hooks to exit at that point.

       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 obtained 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.

       $protocol                    the protocol that triggered the event.

       $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
       /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

       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.

Debian                                          February 20, 2018                            DHCPCD-RUN-HOOKS(8)