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spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD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

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

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.

Mechanically substitute flags from historic mbuf allocator with
malloc(9) flags within sys.

Exceptions:

- sys/contrib not touched
- sys/mbuf.h edited manually

Upgrade the netgraph vlan node to support 802.1q, encapsulation type,
PCP and CFI fields.

* Ethernet_type for VLAN encapsulation is tunable, default is 0x8100;
* PCP (Priority code point) and CFI (canonical format indicator) is
tunable per VID;
* Tunable encapsulation to support 802.1q
* Encapsulation/Decapsulation code improvements

New messages have been added for this netgraph node to support the
new features.

However, the legacy "vlan" id is still supported and compiled in by
default. It can be disabled in a future release.

TODO:

* Documentation
* Examples

PR: kern/161908
Submitted by: Ivan <rozhuk.im@gmail.com>

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.

Retire the MALLOC and FREE macros. They are an abomination unto style(9).

MFC after: 3 months

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

Silence a gcc warning in a more canonical way (evl = NULL rather than &evl).
I saw warnings here at one point on the arm build.

Move ethernet VLAN tags from mtags to its own mbuf packet header field
m_pkthdr.ether_vlan. The presence of the M_VLANTAG flag on the mbuf
signifies the presence and validity of its content.

Drivers that support hardware VLAN tag stripping fill in the received
VLAN tag (containing both vlan and priority information) into the
ether_vtag mbuf packet header field:

m->m_pkthdr.ether_vtag = vlan_id; /* ntohs()? */
m->m_flags |= M_VLANTAG;

to mark the packet m with the specified VLAN tag.

On output the driver should check the mbuf for the M_VLANTAG flag to
see if a VLAN tag is present and valid:

if (m->m_flags & M_VLANTAG) {
... = m->m_pkthdr.ether_vtag; /* htons()? */
... pass tag to hardware ...
}

VLAN tags are stored in host byte order. Byte swapping may be necessary.

(Note: This driver conversion was mechanic and did not add or remove any
byte swapping in the drivers.)

Remove zone_mtag_vlan UMA zone and MTAG_VLAN definition. No more tag
memory allocation have to be done.

Reviewed by: thompsa, yar
Sponsored by: TCP/IP Optimization Fundraise 2005

When netgraph flow control message comes from downstream, broadcast
it to all vlans.

Sponsored by: Rambler

Switch to using C99 sparse initialisers for the type methods array.
Should make no binary difference.

Submitted by: Gleb Smirnoff <glebius@cell.sick.ru>
Reviewed by: Harti Brandt <harti@freebsd.org>
MFC after: 1 week

Netgraph node type for IEEE 802.1Q VLAN tagging.