Remove workaround for ancient HTML generation code.

branches: 1.44.18;
Merge riastradh-drm2 to HEAD.

Use Mt for email addresses.

branches: 1.42.10; 1.42.16; 1.42.20;
Get rid of an extranous .Ed request, and the warning about
unknown NetBSD version `A'.

Drop trailing whitespace. Remove unneeded Pp before Ss.

* in diagrams, name routers as such
* enhance formatting
* add section headers for examples

normalize license (cosmetics only)

branches: 1.38.2;
Convert TNF licenses to new 2 clause variant

branches: 1.37.10; 1.37.12;
Remove remarks that insinuate that gre(4) still supports the hack
that let us set a route over the tunnel to the tunnel's decapsulating
host. Thanks, Andreas Wrede, for pointing it out.

Remove superfluous Pp; use Nm instead of Xr to ourselves; bump date for v1.32.

Drop trailing whitespace.

Change date to reflect today's change.

Try to get groff -mdoc to stop inserting extraneous linebreaks---no
luck!

Per discussion on tech-net@, discard the address-munging hack that
let one create a tunnel with equal inner and outer destination IP
numbers. Update gre(4) documentation for this change.

Extract subroutine gre_update_route() from gre_compute_route(),
and always call it in gre_output() to freshen the route for
tunnel-encapsulated packets.

Add a mode to gre(4) that sends GRE tunnel packets in UDP datagrams.
Fix MOBILE encapsulation. Add many debugging printfs (mainly
concerning UDP mode). Clean up the gre(4) code a bit. Add the
capability to setup UDP tunnels to ifconfig. Update documentation.

In UDP mode, gre(4) puts a GRE header onto transmitted packets,
and hands them to a UDP socket for transmission. That is, the
encapsulation looks like this: IP+UDP+GRE+encapsulated packet.

There are two ways to set up a UDP tunnel. One way is to tell the
source and destination IP+port to gre(4), and let gre(4) create
the socket. The other way to create a UDP tunnel is for userland
to "delegate" a UDP socket to the kernel.

Bump date for previous. Remove trailing whitespace.
New sentence, new line. Fix some macro usage.

Extend EXAMPLES section for IPv6 over GRE. Contributed by Gert Doering.

branches: 1.29.6;
Remove duplicate word in license.
Noted by jmc@openbsd, and approved by Heiko W. Rupp and board@.

SIOCSIFADDR/IFDSTADDR destroys outer address settings, therefore, we need to
do "ifconfig tunnel C D" after "ifconfig A B". i believe the behavir is weird
and non-intuitive, and should be fixex.

While we're rototilling the man page: Use more markup; grammar fixes;
remove another reference to unsupported AppleTalk; update .Dd.

gre(4) supports IPv4/AppleTalk/NS over IPv4, not just IPv4 over IPv4.

deprecate IFF_LINK2, !IFF_LINK0 is enough.
no need to manipulate IFF_LINK1 with IFF_LINK0.
remove reference to greconfig(8).

Oops, typos in the new example.
Also note that the new example is a good example for LINK1 useage, so add
that as well.

Improve a bit, add another example, remove a bogus BUGS entry, add a note
for MTU adjustment.

Whitespace nit.

More ipip references

Traceroute works now.

Generate <>& symbolically. I'm avoiding .../dist/... directories for now.

English

update man page to mention that you need to do "ifconfig greN create" before
using greN even if config'd into the kernel.

Sort SEE ALSO, sort sections, drop some .Pp, improve markup.

Use standard section headers; uppercase .Sh argument; remove quotes in
.Sh arguments.

Fix date and punctuation.

Improve markup slightly (still enough to do here); sort SEE ALSO.
Whitespace fixes.

Upate for the cloning nature of gre(4).

branches: 1.11.4;
GC spurious blank lines.

Use a fixed-width font for network topology illustrations.

Misc small fixes to try to standardise the format to make it easier
to parse by an automated script (say one that just might want to
generate webpage summaries of available drivers :)

s/ the the / the /

branches: 1.7.2;
document link1

branches: 1.6.2;
More and more of .Os cleanups. .Os is defined in the tmac.doc-common file,
so we shouldn't override it with versions in the manpages. Many more to
come.

The gre pseudo-interface no longer suppports IPIP, this is done by the ipip
driver now.

Fix some Typos.

Add for IPPROTO_MOBILE.

s/tun/gre/

Manpage for gre network interface.