MFC r228259:

MFC r228259:
Support domain-search in dhclient(8)

The "domain-search" option (option 119) allows a DHCP server to publish
a list of implicit domain suffixes used during name lookup. This option
is described in RFC 3397.

For instance, if the domain-search option says:
    ".example.org .example.com"
and one wants to resolve "foobar", the resolver will try:
    1. "foobar.example.org"
    2. "foobar.example.com"

The file /etc/resolv.conf is updated with a "search" directive if the
DHCP server provides "domain-search".

A regression test suite is included in this patch under
tools/regression/sbin/dhclient.

PR:		bin/151940
Sponsored by:	Yakaz (http://www.yakaz.com)

MFC r229000:
Invalid Domain Search option isn't considered as a fatal error

In the original Domain Search option patch, an invalid option value
would cause the whole lease to be rejected. However, DHCP servers who
emit such an invalid value are more common than I thought. With this new
patch, just the option is rejected, not the entire lease.

PR:		bin/163431
Submitted by:	Fabian Keil <fk@fabiankeil.de> (earlier version)
Reviewed by:	Fabian Keil <fk@fabiankeil.de>
Sponsored by:	Yakaz (http://www.yakaz.com)

MFC r229001:
Adapt testsuite following change in Domain Search error handling

In this testsuite, warning() and error() have the same behaviour.

PR:		bin/163431
Sponsored by:	Yakaz (http://www.yakaz.com)

git-svn-id: svn://svn.freebsd.org/base/stable/9@230597 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f