MFC r329754:

dhclient: raise WARNS to 4

Mostly const-correctness fixes. There were also some variable-shadowing,
unused variable, and a couple of sockaddr type-correctness changes. I also had
trouble with cast-align warnings. I was able to prove that one of them was a
false positive. But ultimately I had to disable the warning program-wide to
deal with the others.

Reviewed by: cem
Sponsored by: Spectra Logic Corp
Differential Revision: https://reviews.freebsd.org/D14460

Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

MFC r305306:

dhclient: add support for interface-mtu (26)

Make dhclient set interface MTU if it was provided.

This version implements MTU setting in dhclient itself before it runs
dhclient-script.

PR: 206721

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

MFC r326834, r326853

r326834:
dhclient(8): Don't shift through the sign bit of a signed int

PR: 208007
Submitted by: Michael McConville <mmcco@mykolab.com>

r326853:
dhclient(8): raise WARNS to 3

Mostly had to fix a lot of signed/unsigned comparison warnings

Sponsored by: Spectra Logic Corp

MFC r315199,r315200,r315203:

r315199:

sbin/dhclient: fix a memory leak in parse_client_lease_statement(..)

The memory stored by `lease` would have previously been leaked if an
unterminated lease declaration was found in an early-return code path.

CID: 1007114

r315200:

Fix -Wunused-but-set-warning with `ret`

While here, resolve Coverity warnings by demonstrating that vfprintf's
return value is being explicitly ignored.

Tested with: clang, gcc 4.2.1, gcc 6.3.0

r315203:

sbin/dhclient: fix `vendor` storage leak in parse_option_decl(..)

This ensures the storage isn't leaked when non-NULL and the function
returns early, prior to the `free(vendor)` later on in the function.

CID: 1007111-1007113

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

When acquiring a lease, record the value of the BOOTP siaddr field
contained in the DHCP offer, and write it out to the lease file
as an unquoted value of the "next-server" keyword. The value is ignored
when the lease is read back by dhclient, however other applications
are free to parse it.

The intent behind this change is to allow easier interoperability
with automated installation systems e.g. Cobbler, Foreman, Razor;
FreeBSD installation kernels can automatically probe the network
to discover deployment servers. There are no plans to MFC this
change unless a backport is specifically requested.

The syntax of the "next-server <ip>" lease keyword is intended to be
identical to that used by the ISC DHCPD server in its configuration files.
The required defines are already present in dhclient but were unused before
this change. (Note: This is NOT the same as Option 66, tftp-server-name).

It has been exercised in a university protocol testbed environment, with
Cobbler and an mfsBSD image containing pc-sysinstall (driven by Cobbler
Cheetah templates). The SYSLINUX memdisk driver is used to boot mfsBSD.
Currently this approach requires that a dedicated system profile has
been created for the node where FreeBSD is to be deployed. If this
is not present, the pc-sysinstall wrapper will be unable to obtain
a node configuration. There is code in progress to allow mfsBSD images
to obtain the required hints from the memdisk environment by parsing
the MBFT ACPI chunk. This is non-standard as it is not linked into
the platform's ACPI RSDT.

Reviewed by: des

In sbin/dhclient, since we know the size of the source strings anyway,
we might as well use memcpy; strlcpy is really unnecessary here.

MFC after: 1 week

In sbin/dhclient, work around warnings about the size argument to
strlcpy appearing to be the size of the source buffer, instead of the
destination.

MFC after: 1 week

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)

Implement RFC3442, the Classless Static Route option.

The original DHCP specification includes a route option but it supports
only class-based routes. RFC3442 adds support for specifying the netmask
width for each static route. A variable length encoding is used to minimize
the size of this option.

PR: bin/99534
Submitted by: Andrey V. Elsukov <bu7cher@yandex.ru>
Reviewed by: brooks

Add __FBSDID to all .c files in dhclient to aid in determining file
versions when dealing with user problems.

This commit was generated by cvs2svn to compensate for changes in r147072,
which included commits to RCS files with non-trunk default branches.

Import the OpenBSD dhclient as shipped with OpenBSD-3.7 (the tag
OPENBSD_3_7).