Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

Violators may define _WANT_SOCKET and _WANT_UNPCB respectively and
are not guaranteed for stability of the structures.  The violators
list is the the usual one: libprocstat(3) and netstat(1) internally
and lsof in ports.

In struct xunpcb remove the inclusion of kernel structure and add
a bunch of spare fields.  The xsocket already has socket not included,
but add there spares as well.  Embed xsockbuf into xsocket.

Sort declarations in sys/socketvar.h to separate kernel only from
userland available ones.

PR:		221820 (exp-run)

nl_symbols will eventually be organized into several modules depending
on MK_* variables.

Obtained from:  Phil Shafer <phil@juniper.net>
Ported to -current by: alfred@ (mostly), Kim Shrier
Formatting: marcel@
Sponsored by:   Juniper Networks, Inc.

o Introduce a notion of "not ready" mbufs in socket buffers.  These
mbufs are now being populated by some I/O in background and are
referenced outside.  This forces following implications:
- An mbuf which is "not ready" can't be taken out of the buffer.
- An mbuf that is behind a "not ready" in the queue neither.
- If sockbet buffer is flushed, then "not ready" mbufs shouln't be
  freed.

o In struct sockbuf the sb_cc field is split into sb_ccc and sb_acc.
  The sb_ccc stands for ""claimed character count", or "committed
  character count".  And the sb_acc is "available character count".
  Consumers of socket buffer API shouldn't already access them directly,
  but use sbused() and sbavail() respectively.
o Not ready mbufs are marked with M_NOTREADY, and ready but blocked ones
  with M_BLOCKED.
o New field sb_fnrdy points to the first not ready mbuf, to avoid linear
  search.
o New function sbready() is provided to activate certain amount of mbufs
  in a socket buffer.

A special note on SCTP:
  SCTP has its own sockbufs.  Unfortunately, FreeBSD stack doesn't yet
allow protocol specific sockbufs.  Thus, SCTP does some hacks to make
itself compatible with FreeBSD: it manages sockbufs on its own, but keeps
sb_cc updated to inform the stack of amount of data in them.  The new
notion of "not ready" data isn't supported by SCTP.  Instead, only a
mechanical substitute is done: s/sb_cc/sb_ccc/.
  A proper solution would be to take away struct sockbuf from struct
socket and allow protocols to implement their own socket buffers, like
SCTP already does.  This was discussed with rrs@.

Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.

necessary symbols needed per subsystem. Main kvm(3) init is now delayed
as much as possbile. This finally fixes performance issues reported in
kern/167204.
Some non-working code (ng_socket.ko symbol addresses calculation) removed.
Some global variables eliminated.

PR:		kern/167204
MFC after:	4 weeks

breaks ABI, but makes probability of ABI breakage in future less.

starting from netgraph import in 1999.

netstat(8) used pointer to node as node address, oops. That didn't
work, we need the node ID in brackets to successfully address a node.
We can't look into ng_node, due to inability to include netgraph/netgraph.h
in userland code. So let the node make a hint for a userland, storing
the node ID in its private data.

MFC after:	2 weeks

needed.

Tested with:	make universe