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)

2 files changed, 2 insertions, 0 deletions

diff --git a/sys/sys/priv.h b/sys/sys/priv.h
index 7ef54782a60d..9d8a3204add5 100644
--- a/sys/sys/priv.h
+++ b/sys/sys/priv.h
@@ -347,6 +347,7 @@
 #define	PRIV_NET_VXLAN		420	/* Administer vxlan. */
 #define	PRIV_NET_SETLANPCP	421	/* Set LAN priority. */
 #define	PRIV_NET_SETVLANPCP	PRIV_NET_SETLANPCP /* Alias Set VLAN priority */
+#define	PRIV_NET_WG		422	/* Administrate if_wg. */
 
 /*
  * 802.11-related privileges.
diff --git a/sys/sys/socketvar.h b/sys/sys/socketvar.h
index 295a1cf3d37f..a5bb8a2587ea 100644
--- a/sys/sys/socketvar.h
+++ b/sys/sys/socketvar.h
@@ -414,6 +414,7 @@ void	soaio_enqueue(struct task *task);
 void	soaio_rcv(void *context, int pending);
 void	soaio_snd(void *context, int pending);
 int	socheckuid(struct socket *so, uid_t uid);
+int	sogetsockaddr(struct socket *so, struct sockaddr **nam);
 int	sobind(struct socket *so, struct sockaddr *nam, struct thread *td);
 int	sobindat(int fd, struct socket *so, struct sockaddr *nam,
 	    struct thread *td);