Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Make ppp WARNS=5 clean

Reduce MAXMSS limit by 12 bytes to allow for rfc 1323.

PR: 32717
Submitted by: MORI Kouji <moriko@hh.iij4u.or.jp>
MFC after: 2 weeks

Remove whitespace at the end of lines.

o Clean up some #includes
o Bump version number to 3.0.4
o When talking to a RADIUS server, provide a NAS-Port-Type.

When the NAS-Port-Type is Ethernet, provide a NAS-Port value equal
to the SESSIONID from the environment in direct mode or the
NGM_PPPOE_SESSIONID message in other modes. If no SESSIONID is found,
default to the interface index in client mode or zero in server mode.

When the NAS-Port-Type is ISDN, set the NAS-Port to the minor number
of the physical device (ie, the N in /dev/i4brbchN).

This makes it easier for the RADIUS server to identify the client
WRT accounting data etc.

Prompted by: lsz8425 <lsz8425@mail.cd.hn.cn>

o Add ipv6 support, abstracting most NCP addresses into opaque
structures (well, they're treated as opaque).

It's now possible to manage IPv6 interface addresses and routing
table entries and to filter IPV6 traffic whether encapsulated or
not.

IPV6CP support is crude for now, and hasn't been tested against
any other implementations.

RADIUS and IPv6 are independent of eachother for now.

ppp.linkup/ppp.linkdown aren't currently used by IPV6CP

o Understand all protocols(5) in filter rules rather than only a select
few.

o Allow a mask specification for the ``delete'' command. It's now
possible to specifically delete one of two conflicting routes.

o When creating and deleting proxy arp entries, do it for all IPv4
interface addresses rather than doing it just for the ``current''
peer address.

o When iface-alias isn't in effect, don't blow away manually (via ``iface
add'') added interface addresses.

o When listening on a tcp server (diagnostic) socket, bind so that a
tcp46 socket is created -- allowing both IPv4 and IPv6 connections.

o When displaying ICMP traffic, don't display the icmp type twice.
When display traffic, display at least some information about unrecognised
traffic.

o Bump version

Inspired after filtering work by: Makoto MATSUSHITA <matusita@jp.FreeBSD.org>

Perform MSS fixups on incoming packets as well as outgoing.

MFC after: 1 week

Handle hardware-imposed MTU/MRU limitations. PPPoE will no longer
allow MRU/MTU negotiations to exceed 1492.

Add an optional ``max'' specifier to ``set m[rt]u'', ie.

set mtu max 1480

Bump the ppp version number.

Sponsored by: Monzoon Networks AG and FreeBSD Services Limited

Add ``enable/disable tcpmssfixup'', defaulting to enabled.

Suggested by: julian
Hijacked from: ru (ports/net/tcpmssd)