net: wireguard: Add support for wireguard in-tree

net/Kconfig

@@ -83,6 +83,7 @@ config INET
 	  Short answer: say Y.
 
 if INET
+source "net/wireguard/Kconfig"
 source "net/ipv4/Kconfig"
 source "net/ipv6/Kconfig"
 source "net/netlabel/Kconfig"

net/Makefile

@@ -14,6 +14,7 @@ obj-$(CONFIG_NET)		+= $(tmp-y)
 obj-$(CONFIG_LLC)		+= llc/
 obj-$(CONFIG_NET)		+= ethernet/ 802/ sched/ netlink/
 obj-$(CONFIG_NETFILTER)		+= netfilter/
+obj-$(CONFIG_WIREGUARD)		+= wireguard/
 obj-$(CONFIG_INET)		+= ipv4/
 obj-$(CONFIG_XFRM)		+= xfrm/
 obj-$(CONFIG_UNIX)		+= unix/

net/wireguard/Kconfig

@@ -0,0 +1,33 @@
+config WIREGUARD
+	tristate "IP: WireGuard secure network tunnel"
+	depends on NET && INET
+	depends on IPV6 || !IPV6
+	select NET_UDP_TUNNEL
+	select DST_CACHE
+	select CRYPTO
+	select CRYPTO_ALGAPI
+	select VFP
+	select VFPv3 if CPU_V7
+	select NEON if CPU_V7
+	select KERNEL_MODE_NEON if CPU_V7
+	default m
+	help
+	  WireGuard is a secure, fast, and easy to use replacement for IPsec
+	  that uses modern cryptography and clever networking tricks. It's
+	  designed to be fairly general purpose and abstract enough to fit most
+	  use cases, while at the same time remaining extremely simple to
+	  configure. See www.wireguard.com for more info.
+
+	  It's safe to say Y or M here, as the driver is very lightweight and
+	  is only in use when an administrator chooses to add an interface.
+
+config WIREGUARD_DEBUG
+	bool "Debugging checks and verbose messages"
+	depends on WIREGUARD
+	help
+	  This will write log messages for handshake and other events
+	  that occur for a WireGuard interface. It will also perform some
+	  extra validation checks and unit tests at various points. This is
+	  only useful for debugging.
+
+	  Say N here unless you know what you're doing.

net/wireguard/Makefile

@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+
+ccflags-y := -D'pr_fmt(fmt)=KBUILD_MODNAME ": " fmt'
+ccflags-y += -Wframe-larger-than=2048
+ccflags-$(CONFIG_WIREGUARD_DEBUG) += -DDEBUG -g
+ccflags-$(if $(WIREGUARD_VERSION),y,) += -D'WIREGUARD_VERSION="$(WIREGUARD_VERSION)"'
+
+wireguard-y := main.o noise.o device.o peer.o timers.o queueing.o send.o receive.o socket.o peerlookup.o allowedips.o ratelimiter.o cookie.o netlink.o
+
+include $(src)/crypto/Makefile.include
+include $(src)/compat/Makefile.include
+
+obj-$(if $(KBUILD_EXTMOD),m,$(CONFIG_WIREGUARD)) := wireguard.o