Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD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

Fix the following -Werror warning from clang 10.0.0 in bsnmpd:

usr.sbin/bsnmpd/modules/snmp_bridge/bridge_port.c:1235:43: error: overlapping comparisons always evaluate to true [-Werror,-Wtautological-overlap-compare]
begemotBridgeStpPortEnable_enabled ||
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~

Work around it by casting the enum values to the type of val->v.integer.

MFC after: 3 days

Update bsnmp to version 1.13. This does not bring user-visible changes.
For developers gensnmptree can now generate functions for enums to convert
between enums and strings and to check the validity of a value.
The sources in FreeBSD are now in sync with the upstream which allows to
bring in IPv6 modifications.

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.

style(9): clean up trailing whitespace

MFC after: 3 weeks

Spelling fixes for usr.sbin/

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.

- Import the HEAD csup code which is the basis for the cvsmode work.

Keep the snmp_bridge(3) module up to date with if_bridge(4) and add an
object to control the value of the new 'PRIVATE' bridge members' flag.
While here, remove stale '__unused' compiler directives.

Reviewed by: bz
Approved by: re (bmah), bz (mentor)

Keep in sync with the if_bridge(4) module (rev. 1.20 if_bridgevar.h,
1.12 bridgestp.h) and rename all PointToPoint related variables
from P2P to PTP (s/P2P/PTP/g s/p2p/ptp/g).

Approved by: bz (mentor)

Do not add 'default:' cases inside a switch() on an enum like the
SNMP option argument. That way the compiler will give a warning in
case of a missing or an extra but unknown 'case:'.
Do the same for SNMP LEAF objects to be prepared once gensnmptree will
auto-generate enums for those too.
Add an abort() after the switch() instead of the 'default:' to catch
any errors. The nice side effect is that the compiler will correctly
track supposed to be 'uninitialized' variables with that.

When trying to set a value sanity check it before calling the OS
dependent API of snmp_bridge to tell whether it is an attempt to
set a bad value or a general error.

Suggested by: harti (first part)
Approved by: bz (mentor)

Instead of explicitly initializing variables to avoid compiler warnings,
add a default case to handle the situation when the variables are not
initialized.
Furthermore, abort() if the snmp agent passes an invalid option to the
bridge module. As the option (SET, GET, GETNEXT, COMMIT, ROLLBACK) is
determined by the snmp agent based on the operation requested by user,
this behaviour is unlikely to be abused as a source for a DoS, but if
ever hit will likely reveal a problem in the snmp agent or bridge
module.

Approved by: bz (mentor)

Add support for RSTP (RFC4318) to the SNMP bridge monitoring module.

Approved by: bz (mentor)

Bring in a SNMP module to support monitoring if_bridge(4) interfaces
via bsnmpd(1). The module implements IETF BRIDGE-MIB as defined in
RFC4188 and a private BEGEMOT-BRIDGE-MIB.

Sponsored by: Google Summer of Code 2006
Reviewed by: bz
Approved by: bz (mentor)