if_wg: import latest fixup work from the wireguard-freebsd project

This is the culmination of about a week of work from three developers to
fix a number of functional and security issues.  This patch consists of
work done by the following folks:

- Jason A. Donenfeld <Jason@zx2c4.com>
- Matt Dunwoodie <ncon@noconroy.net>
- Kyle Evans <kevans@FreeBSD.org>

Notable changes include:
- Packets are now correctly staged for processing once the handshake has
  completed, resulting in less packet loss in the interim.
- Various race conditions have been resolved, particularly w.r.t. socket
  and packet lifetime (panics)
- Various tests have been added to assure correct functionality and
  tooling conformance
- Many security issues have been addressed
- if_wg now maintains jail-friendly semantics: sockets are created in
  the interface's home vnet so that it can act as the sole network
  connection for a jail
- if_wg no longer fails to remove peer allowed-ips of 0.0.0.0/0
- if_wg now exports via ioctl a format that is future proof and
  complete.  It is additionally supported by the upstream
  wireguard-tools (which we plan to merge in to base soon)
- if_wg now conforms to the WireGuard protocol and is more closely
  aligned with security auditing guidelines

Note that the driver has been rebased away from using iflib.  iflib
poses a number of challenges for a cloned device trying to operate in a
vnet that are non-trivial to solve and adds complexity to the
implementation for little gain.

The crypto implementation that was previously added to the tree was a
super complex integration of what previously appeared in an old out of
tree Linux module, which has been reduced to crypto.c containing simple
boring reference implementations.  This is part of a near-to-mid term
goal to work with FreeBSD kernel crypto folks and take advantage of or
improve accelerated crypto already offered elsewhere.

There's additional test suite effort underway out-of-tree taking
advantage of the aforementioned jail-friendly semantics to test a number
of real-world topologies, based on netns.sh.

Also note that this is still a work in progress; work going further will
be much smaller in nature.

MFC after:	1 month (maybe)

1 files changed, 2 insertions, 2 deletions

diff --git a/sys/netinet6/nd6.c b/sys/netinet6/nd6.c
index 62f0ac733a23..7937749c1299 100644
--- a/sys/netinet6/nd6.c
+++ b/sys/netinet6/nd6.c
@@ -284,8 +284,8 @@ nd6_ifattach(struct ifnet *ifp)
 	 * default regardless of the V_ip6_auto_linklocal configuration to
 	 * give a reasonable default behavior.
 	 */
-	if ((V_ip6_auto_linklocal && ifp->if_type != IFT_BRIDGE) ||
-	    (ifp->if_flags & IFF_LOOPBACK))
+	if ((V_ip6_auto_linklocal && ifp->if_type != IFT_BRIDGE &&
+	    ifp->if_type != IFT_WIREGUARD) || (ifp->if_flags & IFF_LOOPBACK))
 		nd->flags |= ND6_IFF_AUTO_LINKLOCAL;
 	/*
 	 * A loopback interface does not need to accept RTADV.