MFC r326276:

various: 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.

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

Conditionally add the interface name and address if available
so that a ppp running in `receiver' (server) mode can properly
update routes, for example to update the MTU.

Submitted by: loos.br gmail.com (Luiz Otavio O Souza)
PR: bin/130159
PR: kern/125079, kern/122068, bin/126892
MFC after: 3 days

Specify the gateway address when updating the MTU and send/recv pipe
sizes on a route.

IMHO this shouldn't be necessary (the destination & mask/prefixlen
should be enough), but without it, the default route update under
OpenBSD will fail.

Thanks to: Russell T Hunt <alaric@MIT.EDU>

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>

Convert IIJ copyrights to BSD copyrights.

Approved by: Toshiharu OHNO <tohno@sirius.ocn.ne.jp>

When we change the interface MTU, run through the routing table and tweak
all route MTUs too.

Add the ``resolv'' command for telling ppp how to deal with resolv.conf.
You can now ``resolv restore'' in ppp.linkdown !
Add DNS0 and DNS1 macros.

The interface list that comes back from the PF_ROUTE/NET_RT_IFLIST mib
is aligned. Teach this to ``show route''.

Clean up some of the sockaddr parsing routines.

$Id$ -> $FreeBSD$

Initial RADIUS support (using libradius). See the man page for
details. Compiling with -DNORADIUS (the default for `release')
removes support.

TODO: The functionality in libradius::rad_send_request() needs
to be supplied as a set of routines so that ppp doesn't
have to wait indefinitely for the radius server(s). Instead,
we need to get a descriptor back, select() on the descriptor,
and ask libradius to service it when necessary.
For now, ppp blocks SIGALRM while in rad_send_request(), so
it misses PAP/CHAP retries & timeouts if they occur.

Only PAP is functional. When CHAP is attempted, libradius
complains that no User-Password has been specified... rfc2138
says that it *mustn't* be used for CHAP :-(

Sponsored by: Internet Business Solutions Ltd., Switzerland

MFMP: Make ppp multilink capable.
See the file README.changes, and re-read the man page.

Reimplement proxy-arp address stuff using sysctl().

Allow "add! dst mask gw" (note the ``!'') to do an
RTM_CHANGE if the RTM_ADD fails with an EEXIST.
Allow "delete! dst" (note the ``!'') to silently
fail if the RTM_DELETE fails with an ESRCH.
Also, make the ESRCH and EEXIST error conditions
more understandable to the casual observer.

Allow random IP number allocation to peer.
Validate the peers suggested IP by attempting to make a routing table
entry.
Give up IPCP negotiation if the peer NAKs us with an unusable IP.
Always SIOCDIFADDR then SIOCAIFADDR when configuring the tun device.
Using SIOCSIFDSTADDR allows duplicate dst addresses (which we don't
want)!!!
Allow up to 200 interface names (was 50) (now that ppp can play server
properly).
Up the version number (1.5 -> 1.6).

Cosmetic:
Log unexpected CCP packets in the CCP log rather than the ERROR log.
Log unexpected Config Reqs in the appropriate LCP/IPCP/CCP log rather
than the ERROR log.
Log failed route additions and deletions with WARN, not TCPIP.
Log the option id and length for unrecognised IPCP options.
Change some .Sq to .Ar in the man page.

Fix prototypes.
Remove extraneous decls.
Add ``const'' to several places.
Allow ``make NOALIAS=1'' to remove IP aliasing.
Merge with OpenBSD - only the Makefiles vary.

We can now survive a compile with
-Wall -Wbad-function-cast -Wcast-align -Wcast-qual
-Winline -Wmissing-declarations -Wmissing-prototypes
-Wnested-externs -Wpointer-arith -Wredundant-decls
-Wshadow -Wstrict-prototypes -Wwrite-strings -Wchar-subscripts
(although the Makefile just contains -Wall).

Cosmetic (no functional changes):
o Add missing $Id$s
o Move extern decls from .c -> .h files
o Staticize
o Remove #includes from .h files
o style(9)ify includes
o bcopy -> memcpy
bzero -> memset
bcmp -> memcmp
index -> strchr
rindex -> strrchr
o Move timeout.h -> timer.h (making it consistent w/ timer.c)
o Add -Wmissing-prototypes

Make the code format more in line with style(9).
Update loadalias to use the new libalias api.
Update to version 1.1.

Overhaul ppp:
o Use syslog
o Remove references to stdout/stderr (incl perror())
o Introduce VarTerm - the interactive terminal or zero
o Allow "set timeout" to affect current session
o Change "set debug" to "set log"
o Allow "set log [+|-]flag"
o Make MSEXT and PASSWDAUTH stuff the default
o Move all #ifdef DEBUG stuff into the code - this
shouldn't be too much overhead. It's now controlled
with "set log +debug"
o Add "set log command, debug, tun, warn, error, alert"
o Remove cdefs.h, and assume an ansi compiler.
o Improve all diagnostic output
o Don't trap SIGSEGV
o SIGHUP now terminates again (log files are controlled
by syslog)
o Call CloseModem() when changing devices
o Fix parsing of third arg of "delete"

I think this fixes the "magic is same" problems that some
people have been experiencing.
The man page is being rewritten. It'll follow soon.

Revert $FreeBSD$ to $Id$

Make the long-awaited change from $Id$ to $FreeBSD$

This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.

Final cleanup for now. -Wall is now silent. A couple of bogons found.