Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

Since size of struct in_aliasreq has just been changed in r228571,
and thus ifconfig(8) needs recompile, it is a good chance to make
parameter checks on SIOCAIFADDR arguments more strict.

A major overhaul of the CARP implementation. The ip_carp.c was started
from scratch, copying needed functionality from the old implemenation
on demand, with a thorough review of all code. The main change is that
interface layer has been removed from the CARP. Now redundant addresses
are configured exactly on the interfaces, they run on.

The CARP configuration itself is, as before, configured and read via
SIOCSVH/SIOCGVH ioctls. A new prefix created with SIOCAIFADDR or
SIOCAIFADDR_IN6 may now be configured to a particular virtual host id,
which makes the prefix redundant.

ifconfig(8) semantics has been changed too: now one doesn't need
to clone carpXX interface, he/she should directly configure a vhid
on a Ethernet interface.

To supply vhid data from the kernel to an application the getifaddrs(8)
function had been changed to pass ifam_data with each address. [1]

The new implementation definitely closes all PRs related to carp(4)
being an interface, and may close several others. It also allows
to run a single redundant IP per interface.

Big thanks to Bjoern Zeeb for his help with inet6 part of patch, for
idea on using ifam_data and for several rounds of reviewing!

PR: kern/117000, kern/126945, kern/126714, kern/120130, kern/117448
Reviewed by: bz
Submitted by: bz [1]

For unknown reason, since rev 1.1 of ifconfig.c, sin_family isn't
set properly for the mask argument.

Since I'd like to improve argument sanity checking in kernel
side, in in_control(), fix this.

If compiling RESCUE always ignore feature_present(3) calls so that
a /rescue/ifconfig more modern than the kernel could still configure
IPv4 or IPv6 addresses.

Reported by: Andrzej Tobola (ato iem.pw.edu.pl)
Reported by: gcooper
MFC after: 1 day
X-MFC: will not MFC any time soon, just reminder for r222527

Conditionally compile in the af_inet and af_inet6, af_nd6 modules.
If compiled in for dual-stack use, test with feature_present(3)
to see if we should register the IPv4/IPv6 address family related
options.

In case there is no "inet" support we would love to go with the
usage() and make the address family mandatory (as it is for anything
but inet in theory). Unfortunately people are used to
ifconfig IF up/down
etc. as well, so use a fallback of "link". Adjust the man page
to reflect these minor details.

Improve error handling printing a warning in addition to the usage
telling that we do not know the given address family in two places.

Reviewed by: hrs, rwatson
Sponsored by: The FreeBSD Foundation
Sponsored by: iXsystems
MFC after: 2 weeks

Reject invalid CIDR widths rather than silently stopping at the first
non-digit character.

Due to an issue with rc(8) in a test configuration, ifconfig was being
invoked with the address used again as the width - for example,

ifconfig vlan0 10.0.0.1/10.0.0.1

Prior to this change, that address/width would be interpreted as
10.0.0.1/10.

- Use size_t instead of int when appropriate;
- Use C99 sparse initialization.

With these changes ifconfig(8) is WARNS=2 clean.

The structs ifaliasreq and in_aliasreq have exactly the same layout and
member names, but we really do mean to use in_aliasreq here.

MFC after: 1 week

use getifaddrs from libc instead of private code

Reviewed by: bms
MFC after: 1 month

only show a tunnel information of an adequate address family.

Approved by: re (dwhite)

Overhaul to cleanup some of the tangled logic that's grown over the years.

o break per-address family support out into separate files
o modularize per-address family and functional operations using
a registration mechanism; this permits configuration according
to which files you include (but beware that order of the files
is important to insure backwards compatibility)
o many cleanups to eliminate incestuous behaviour, global variables,
and poor coding practices (still much more to fix)

The original motivation of this work was to support dynamic addition
of functionality based on the interface so we can eliminate the various
little control programs and so that vendors can distribute ifconfig
plugins that support their in-kernel code. That work is still to be
completed.

o Update 802.11 support for all the new net80211 functionality; some
of these operations (e.g. list *) may be better suited in a different
program