Provided by: dhcpcd5_7.1.0-2build1_amd64
dhcpcd-run-hooks — DHCP client configuration script
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.
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.
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
Roy Marples <firstname.lastname@example.org>
Please report them to http://roy.marples.name/projects/dhcpcd
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.