Purge more stray embedded $FreeBSD$ strings

These do not use __FBSDID but instead use bare char arrays.

Reviewed by: imp, emaste
Differential Revision: https://reviews.freebsd.org/D41957

ifconfig: remove (most of) the usages of global 'struct ifreq ifr'.

It is hard to reason about the contents of 'ifr' at any given time
as nearly every function sets random fields or pointers in this
structure.
Use local on-stack clean 'struct ifreq' for each function instead.

Reviewed by: kp
Differential Revision: https://reviews.freebsd.org/D40534
MFC after: 2 weeks

ifconfig: fix warnings #2

Fix all -Wparameter-unused and cast alignment

Differential Revision: https://reviews.freebsd.org/D40303
MFC after: 2 weeks

ifconfig: introduce `ifconfig_context` to store current global state.

The structure consists of all current context - arguments,
open sockets, current family and so on.

Pass this structure as a first argument to most of the af_ menthods.
This allows to propagate and update shared data without using
global variables.

The diff is pretty large, but de-facto mechanical. All changes
except the structure setup in ifconfig[_netlink].c are one-line
mechanical changes.

Reviewed by: kp
Differential Revision: https://reviews.freebsd.org/D40239
MFC after: 2 weeks

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

various: general adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

No functional change intended.

- Remove GIF_{SEND,ACCEPT}_REVETHIP.
- Simplify EADDRNOTAVAIL and EAFNOSUPPORT conditions.

MFC after: 3 days

Add an ability accept encapsulated packets from different sources by one
gif(4) interface. Add new option "ignore_source" for gif(4) interface.
When it is enabled, gif's encapcheck function requires match only for
packet's destination address.

Differential Revision: https://reviews.freebsd.org/D2004
Obtained from: Yandex LLC
MFC after: 2 weeks
Sponsored by: Yandex LLC

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Create the altix project branch. The altix project will add support
for the SGI Altix 350 to FreeBSD/ia64. The hardware used for porting
is a two-module system, consisting of a base compute module and a
CPU expansion module. SGI's NUMAFlex architecture can be an excellent
platform to test CPU affinity and NUMA-aware features in FreeBSD.

MFC r196929: Suppress an options line when no bit is on.

Approved by: re (kib)

Use printb() instead of rolling its own routine to display
bits in options=<>.

Pointed out by: ume
MFC after: 3 days

Suppress an options line when no bit is on.

Reviewed by: hrs
MFC after: 3 days

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

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

Fix and add a workaround on an issue of EtherIP packet with reversed
version field sent via gif(4)+if_bridge(4). The EtherIP
implementation found on FreeBSD 6.1, 6.2, 6.3, 7.0, 7.1, and 7.2 had
an interoperability issue because it sent the incorrect EtherIP
packets and discarded the correct ones.

This change introduces the following two flags to gif(4):

accept_rev_ethip_ver: accepts both correct EtherIP packets and ones
with reversed version field, if enabled. If disabled, the gif
accepts the correct packets only. This flag is enabled by
default.

send_rev_ethip_ver: sends EtherIP packets with reversed version field
intentionally, if enabled. If disabled, the gif sends the correct
packets only. This flag is disabled by default.

These flags are stored in struct gif_softc and can be set by
ifconfig(8) on per-interface basis.

Note that this is an incompatible change of EtherIP with the older
FreeBSD releases. If you need to interoperate older FreeBSD boxes and
new versions after this commit, setting "send_rev_ethip_ver" is
needed.

Reviewed by: thompsa and rwatson
Spotted by: Shunsuke SHINOMIYA
PR: kern/125003
MFC after: 2 weeks