sys: 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spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD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 packet cbs/ebs conversion.

Each packet is counted as 128 bytes by the code, not 125. Not sure
what I was thinking about here 14 years ago. May be just a typo.

Reported by: Dmitry Luhtionov <dmitryluhtionov@gmail.com>
MFC after: 2 weeks

netgraph/ng_car: Add color marking code

Chained policing should be able to reuse the classification of
traffic. A new mbuf_tag type is defined to handle gereral QoS
marking. A new subtype is defined to track the color marking.

Reviewed by: manpages (bcr), melifaro, kp
Approved by: kp (mentor)
Sponsored by: IKS Service GmbH
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D22110

net: clean up empty lines in .c and .h files

Fix spelling of "dropped".

Submitted by: Lutz Donnerhacke
Differential Revision: https://reviews.freebsd.org/D23954

sys: 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.

sys/netgraph: spelling fixes in comments.

No functional change.

Node constructor methods are supposed to be called in syscall
context always. Convert nodes to consistently use M_WAITOK flag
for memory allocation.

Reviewed by: julian

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

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

- Account all node stats at the shape mode.
- Do not check destination hook presence, it will be done by netgraph.
- Use u_int instead of int in some places to simplify type conversions.
- Use NG_SEND_DATA_ONLY() macro instead of selfmade equivalent.

Switch from timeval to bintime, to use 1/(2^20) of seconds instead of
microseconds. It allows to use bit shifts instead of some heavy 64bit
mul/div math operations.

Add option to set packets per second limits instead of default
bits per second ones.

Add missing ng_uncallout() on node shutdown.

Approved by: glebius (mentor)

Fix small copy/paste mistake.

Style cleanup.

Approved by: glebius (mentor)

A node that implements various traffic shaping and rate limiting algorithms.

Approved by: glebius (mentor)