d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Resolve conflicts :

Browse Source 
* $FreeBSD$ line.
  * Remove dhcpd and dhcprelay from the SEE ALSO section, since these
    are not in the base system.
This commit is contained in:
Murray Stokely 2002-02-19 11:57:47 +00:00
parent c31fe933fc
commit 92c4d51b6d
1 changed files with 34 additions and 34 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

68
contrib/isc-dhcp/client/dhclient-script.8
View File

@ -1,8 +1,6 @@
.\" dhclient-script.8
.\"
.\" Copyright (c) 1997 The Internet Software Consortium.
.\" All rights reserved.
.\"
.\" Copyright (c) 1996-2001 Internet Software Consortium.
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
@ -31,10 +29,11 @@
.\" SUCH DAMAGE.
.\"
.\" This software has been written for the Internet Software Consortium
.\" by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
.\" Enterprises. To learn more about the Internet Software Consortium,
.\" see ``http://www.isc.org/isc''. To learn more about Vixie
.\" Enterprises, see ``http://www.vix.com''.
.\" by Ted Lemon in cooperation with Vixie Enterprises and Nominum, Inc.
.\" To learn more about the Internet Software Consortium, see
.\" ``http://www.isc.org/''. To learn more about Vixie Enterprises,
.\" see ``http://www.vix.com''. To learn more about Nominum, Inc., see
.\" ``http://www.nominum.com''.
.\"
.\" $FreeBSD$
.\"
@ -61,10 +60,10 @@ No standard client script exists for some operating systems, even though
the actual client may work, so a pioneering user may well need to create
a new script or modify an existing one. In general, customizations specific
to a particular computer should be done in the
.B /etc/dhclient.conf
.B ETCDIR/dhclient.conf
file. If you find that you can't make such a customization without
customizing
.B /etc/dhclient.conf
.B ETCDIR/dhclient.conf
or using the enter and exit hooks, please submit a bug report.
.SH HOOKS
When it starts, the client script first defines a shell function,
@ -76,30 +75,36 @@ the enter hook script.
.PP
On after defining the make_resolv_conf function, the client script checks
for the presence of an executable
.B /etc/dhclient-enter-hooks
.B ETCDIR/dhclient-enter-hooks
script, and if present, it invokes the script inline, using the Bourne
shell '.' command. The entire environment documented under OPERATION
is available to this script, which may modify the environment if needed
to change the behaviour of the script. If an error occurs during the
execution of the script, it can set the exit_status variable to a nonzero
value, and
.B /sbin/dhclient-script
.B CLIENTBINDIR/dhclient-script
will exit with that error code immediately after the client script exits.
.PP
After all processing has completed,
.B /sbin/dhclient-script
.B CLIENTBINDIR/dhclient-script
checks for the presence of an executable
.B /etc/dhclient-exit-hooks
script, which if present is invoked using the '.' command. The exit status
is passed in the exit_status shell variable, and will always be zero if the
script succeeded at the task for which it was invoked.
.B ETCDIR/dhclient-exit-hooks
script, which if present is invoked using the '.' command. The exit
status of dhclient-script will be passed to dhclient-exit-hooks in the
exit_status shell variable, and will always be zero if the script
succeeded at the task for which it was invoked. The rest of the
environment as described previously for dhclient-enter-hooks is also
present. The
.B ETCDIR/dhclient-exit-hooks
script can modify the valid of exit_status to change the exit status
of dhclient-script.
.SH OPERATION
When dhclient needs to invoke the client configuration script, it
writes a shell script into /tmp which defines a variety of variables.
defines a set of variables in the environment, and then invokes
.B CLIENTBINDIR/dhclient-script.
In all cases, $reason is set to the name of the reason why the script
has been invoked. The following reasons are currently defined:
MEDIUM, PREINIT, ARPCHECK, ARPSEND, BOUND, RENEW, REBIND, REBOOT,
EXPIRE, FAIL and TIMEOUT.
MEDIUM, PREINIT, BOUND, RENEW, REBIND, REBOOT, EXPIRE, FAIL and TIMEOUT.
.PP
.SH MEDIUM
The DHCP client is requesting that an interface's media type
@ -118,18 +123,6 @@ and the media type in $medium.
If an IP alias has been declared in dhclient.conf, its address will be
passed in $alias_ip_address, and that ip alias should be deleted from
the interface, along with any routes to it.
.SH ARPSEND
The DHCP client is requesting that an address that has been offered to
it be checked to see if somebody else is using it, by sending an ARP
request for that address. It's not clear how to implement this, so
no examples exist yet. The IP address to check is passed in
$new_ip_address, and the interface name is passed in $interface.
.SH ARPCHECK
The DHCP client wants to know if a response to the ARP request send
using ARPSEND has been received. If one has, the script should exit
with a nonzero status, indicating that the offered address has already
been requested and should be declined. $new_ip_address and
$interface are set as with ARPSEND.
.SH BOUND
The DHCP client has done an initial binding to a new address. The
new ip address is passed in $new_ip_address, and the interface name is
@ -140,6 +133,13 @@ by underscores ('_') in order to make valid shell variables, and the
variable names start with new_. So for example, the new subnet mask
would be passed in $new_subnet_mask.
.PP
Before actually configuring the address, dhclient-script should
somehow ARP for it and exit with a nonzero status if it receives a
reply. In this case, the client will send a DHCPDECLINE message to
the server and acquire a different address. This may also be done in
the RENEW, REBIND, or REBOOT states, but is not required, and indeed
may not be desirable.
.PP
When a binding has been completed, a lot of network parameters are
likely to need to be set up. A new /etc/resolv.conf needs to be
created, using the values of $new_domain_name and
@ -214,14 +214,14 @@ the other. Assuming the information provided by both servers is
valid, this shouldn't cause any real problems, but it could be
confusing.
.SH SEE ALSO
dhclient.conf(5), dhclient.leases(5), dhclient(8), dhcpd(8), and dhcrelay(8).
dhclient.conf(5), dhclient.leases(5), dhclient(8).
.SH AUTHOR
.B dhclient-script(8)
has been written for the Internet Software Consortium
by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
by Ted Lemon in cooperation with Vixie
Enterprises. To learn more about the Internet Software Consortium,
see
.B http://www.vix.com/isc.
.B http://www.isc.org.
To learn more about Vixie
Enterprises, see
.B http://www.vix.com.