kernel: 5.4: import wireguard backport

Rather than using the clunky, old, slower wireguard-linux-compat out of
tree module, this commit does a patch-by-patch backport of upstream's
wireguard to 5.4. This specific backport is in widespread use, being
part of SUSE's enterprise kernel, Oracle's enterprise kernel, Google's
Android kernel, Gentoo's distro kernel, and probably more I've forgotten
about. It's definately the "more proper" way of adding wireguard to a
kernel than the ugly compat.h hell of the wireguard-linux-compat repo.
And most importantly for OpenWRT, it allows using the same module
configuration code for 5.10 as for 5.4, with no need for bifurcation.

These patches are from the backport tree which is maintained in the
open here: https://git.zx2c4.com/wireguard-linux/log/?h=backport-5.4.y
I'll be sending PRs to update this as needed.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 66 insertions, 0 deletions

diff --git a/target/linux/generic/backport-5.4/080-wireguard-0076-wireguard-global-fix-spelling-mistakes-in-comments.patch b/target/linux/generic/backport-5.4/080-wireguard-0076-wireguard-global-fix-spelling-mistakes-in-comments.patch
new file mode 100644
index 0000000000..da9fd72bac
--- /dev/null
+++ b/target/linux/generic/backport-5.4/080-wireguard-0076-wireguard-global-fix-spelling-mistakes-in-comments.patch
@@ -0,0 +1,66 @@
+From 163383e1867a8eb7026d436627bbcd39ecdbd509 Mon Sep 17 00:00:00 2001
+From: Josh Soref <jsoref@gmail.com>
+Date: Sun, 15 Dec 2019 22:08:02 +0100
+Subject: [PATCH 076/124] wireguard: global: fix spelling mistakes in comments
+
+commit a2ec8b5706944d228181c8b91d815f41d6dd8e7b upstream.
+
+This fixes two spelling errors in source code comments.
+
+Signed-off-by: Josh Soref <jsoref@gmail.com>
+[Jason: rewrote commit message]
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+---
+ drivers/net/wireguard/receive.c | 2 +-
+ include/uapi/linux/wireguard.h  | 8 ++++----
+ 2 files changed, 5 insertions(+), 5 deletions(-)
+
+--- a/drivers/net/wireguard/receive.c
++++ b/drivers/net/wireguard/receive.c
+@@ -380,7 +380,7 @@ static void wg_packet_consume_data_done(
+ 	/* We've already verified the Poly1305 auth tag, which means this packet
+ 	 * was not modified in transit. We can therefore tell the networking
+ 	 * stack that all checksums of every layer of encapsulation have already
+-	 * been checked "by the hardware" and therefore is unneccessary to check
++	 * been checked "by the hardware" and therefore is unnecessary to check
+ 	 * again in software.
+ 	 */
+ 	skb->ip_summed = CHECKSUM_UNNECESSARY;
+--- a/include/uapi/linux/wireguard.h
++++ b/include/uapi/linux/wireguard.h
+@@ -18,13 +18,13 @@
+  * one but not both of:
+  *
+  *    WGDEVICE_A_IFINDEX: NLA_U32
+- *    WGDEVICE_A_IFNAME: NLA_NUL_STRING, maxlen IFNAMESIZ - 1
++ *    WGDEVICE_A_IFNAME: NLA_NUL_STRING, maxlen IFNAMSIZ - 1
+  *
+  * The kernel will then return several messages (NLM_F_MULTI) containing the
+  * following tree of nested items:
+  *
+  *    WGDEVICE_A_IFINDEX: NLA_U32
+- *    WGDEVICE_A_IFNAME: NLA_NUL_STRING, maxlen IFNAMESIZ - 1
++ *    WGDEVICE_A_IFNAME: NLA_NUL_STRING, maxlen IFNAMSIZ - 1
+  *    WGDEVICE_A_PRIVATE_KEY: NLA_EXACT_LEN, len WG_KEY_LEN
+  *    WGDEVICE_A_PUBLIC_KEY: NLA_EXACT_LEN, len WG_KEY_LEN
+  *    WGDEVICE_A_LISTEN_PORT: NLA_U16
+@@ -77,7 +77,7 @@
+  * WGDEVICE_A_IFINDEX and WGDEVICE_A_IFNAME:
+  *
+  *    WGDEVICE_A_IFINDEX: NLA_U32
+- *    WGDEVICE_A_IFNAME: NLA_NUL_STRING, maxlen IFNAMESIZ - 1
++ *    WGDEVICE_A_IFNAME: NLA_NUL_STRING, maxlen IFNAMSIZ - 1
+  *    WGDEVICE_A_FLAGS: NLA_U32, 0 or WGDEVICE_F_REPLACE_PEERS if all current
+  *                      peers should be removed prior to adding the list below.
+  *    WGDEVICE_A_PRIVATE_KEY: len WG_KEY_LEN, all zeros to remove
+@@ -121,7 +121,7 @@
+  * filling in information not contained in the prior. Note that if
+  * WGDEVICE_F_REPLACE_PEERS is specified in the first message, it probably
+  * should not be specified in fragments that come after, so that the list
+- * of peers is only cleared the first time but appened after. Likewise for
++ * of peers is only cleared the first time but appended after. Likewise for
+  * peers, if WGPEER_F_REPLACE_ALLOWEDIPS is specified in the first message
+  * of a peer, it likely should not be specified in subsequent fragments.
+  *