Remove $FreeBSD$: one-line sh pattern

Remove /^\s*#[#!]?\s*\$FreeBSD\$.*$\n/

ndp: Prepare for pending tcpdump update

ndp makes use of gmt2local, however that library has been removed from
tcpdump. Add utc_offset() as a substitute.

Reviewed by: emaste, jhb, melifaro
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D40445

ndp: convert ndp(8) to netlink.

The change is intended to be fully transparent to the users.
Similarly to route(8) and netstat(8), ndp can be build without
netlink by defining WITHOUT_NETLINK in make.conf.

Differential Revision: https://reviews.freebsd.org/D39720

ndp(8): add structured output formatting via libxo

Differential Revision: https://reviews.freebsd.org/D35677
MFC after: 2 weeks

Initial implementation of draft-ietf-6man-ipv6only-flag.

This change defines the RA "6" (IPv6-Only) flag which routers
may advertise, kernel logic to check if all routers on a link
have the flag set and accordingly update a per-interface flag.

If all routers agree that it is an IPv6-only link, ether_output_frame(),
based on the interface flag, will filter out all ETHERTYPE_IP/ARP
frames, drop them, and return EAFNOSUPPORT to upper layers.

The change also updates ndp to show the "6" flag, ifconfig to
display the IPV6_ONLY nd6 flag if set, and rtadvd to allow
announcing the flag.

Further changes to tcpdump (contrib code) are availble and will
be upstreamed.

Tested the code (slightly earlier version) with 2 FreeBSD
IPv6 routers, a FreeBSD laptop on ethernet as well as wifi,
and with Win10 and OSX clients (which did not fall over with
the "6" flag set but not understood).

We may also want to (a) implement and RX filter, and (b) over
time enahnce user space to, say, stop dhclient from running
when the interface flag is set. Also we might want to start
IPv6 before IPv4 in the future.

All the code is hidden under the EXPERIMENTAL option and not
compiled by default as the draft is a work-in-progress and
we cannot rely on the fact that IANA will assign the bits
as requested by the draft and hence they may change.

Dear 6man, you have running code.

Discussed with: Bob Hinden, Brian E Carpenter

usr.sbin/ndp: Cleanup in preparation to add libxo support

* Constify rtpref_str declaration
* Remove unused h_errno declaration
* Use time_t type for expire
* Use strlcpy to set static "?" value to ifname
* Rename local variable 's' to stop shadowing global definition
* Close socket used in pfx_flush()
* Use local variables for sock() in setdefif() and getdefif()
* Increase WARNS to 3

Reviewed by: allanjude, kevans
Approved by: allanjude
Sponsored by: Rubicon Communications, LLC (Netgate)
Differential Revision: https://reviews.freebsd.org/D11118

usr.sbin: normalize paths using SRCTOP-relative paths or :H when possible

This simplifies make logic/output

MFC after: 1 month
Sponsored by: Dell EMC Isilon

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.

The last big commit: let usr.sbin/ use WARNS=6 by default.

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

These IPv6-only tools have no explicit dependency on the INET6 macro.

Tested with: cmp(1)

Unbreak the build by dealing with an unexpected dependency on tcpdump source
present in ndp(8).

The vendor branch import uses a _U_ macro to apply the GCC 'unused' attribute
to the rcs ids embedded in each source file. Teach ndp about this.

Perform a major cleanup of the usr.sbin Makefiles.
These are not perfectly in agreement with each other style-wise, but they
are orders of orders of magnitude more consistent style-wise than before.

- Backout botched attempt to introduce MANSECT feature.
- MAN[1-9] -> MAN.

Set the default manual section for usr.sbin/ to 8.

libipsec and IPsec related apps. (and some KAME related man pages)

Reviewed by: freebsd-arch, cvs-committers
Obtained from: KAME project