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, 115 insertions, 0 deletions

diff --git a/target/linux/generic/backport-5.4/080-wireguard-0012-crypto-chacha-unexport-chacha_generic-routines.patch b/target/linux/generic/backport-5.4/080-wireguard-0012-crypto-chacha-unexport-chacha_generic-routines.patch
new file mode 100644
index 0000000000..23a1e41529
--- /dev/null
+++ b/target/linux/generic/backport-5.4/080-wireguard-0012-crypto-chacha-unexport-chacha_generic-routines.patch
@@ -0,0 +1,115 @@
+From 53b97caa431974880c3ea592be870a62e9ef444a Mon Sep 17 00:00:00 2001
+From: Ard Biesheuvel <ardb@kernel.org>
+Date: Fri, 8 Nov 2019 13:22:18 +0100
+Subject: [PATCH 012/124] crypto: chacha - unexport chacha_generic routines
+
+commit 22cf705360707ced15f9fe5423938f313c7df536 upstream.
+
+Now that all users of generic ChaCha code have moved to the core library,
+there is no longer a need for the generic ChaCha skcpiher driver to
+export parts of it implementation for reuse by other drivers. So drop
+the exports, and make the symbols static.
+
+Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
+Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+---
+ crypto/chacha_generic.c          | 26 ++++++++------------------
+ include/crypto/internal/chacha.h | 10 ----------
+ 2 files changed, 8 insertions(+), 28 deletions(-)
+
+--- a/crypto/chacha_generic.c
++++ b/crypto/chacha_generic.c
+@@ -21,7 +21,7 @@ static int chacha_stream_xor(struct skci
+ 
+ 	err = skcipher_walk_virt(&walk, req, false);
+ 
+-	crypto_chacha_init(state, ctx, iv);
++	chacha_init_generic(state, ctx->key, iv);
+ 
+ 	while (walk.nbytes > 0) {
+ 		unsigned int nbytes = walk.nbytes;
+@@ -37,36 +37,27 @@ static int chacha_stream_xor(struct skci
+ 	return err;
+ }
+ 
+-void crypto_chacha_init(u32 *state, const struct chacha_ctx *ctx, const u8 *iv)
+-{
+-	chacha_init_generic(state, ctx->key, iv);
+-}
+-EXPORT_SYMBOL_GPL(crypto_chacha_init);
+-
+-int crypto_chacha20_setkey(struct crypto_skcipher *tfm, const u8 *key,
+-			   unsigned int keysize)
++static int crypto_chacha20_setkey(struct crypto_skcipher *tfm, const u8 *key,
++				  unsigned int keysize)
+ {
+ 	return chacha_setkey(tfm, key, keysize, 20);
+ }
+-EXPORT_SYMBOL_GPL(crypto_chacha20_setkey);
+ 
+-int crypto_chacha12_setkey(struct crypto_skcipher *tfm, const u8 *key,
+-			   unsigned int keysize)
++static int crypto_chacha12_setkey(struct crypto_skcipher *tfm, const u8 *key,
++				 unsigned int keysize)
+ {
+ 	return chacha_setkey(tfm, key, keysize, 12);
+ }
+-EXPORT_SYMBOL_GPL(crypto_chacha12_setkey);
+ 
+-int crypto_chacha_crypt(struct skcipher_request *req)
++static int crypto_chacha_crypt(struct skcipher_request *req)
+ {
+ 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+ 	struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
+ 
+ 	return chacha_stream_xor(req, ctx, req->iv);
+ }
+-EXPORT_SYMBOL_GPL(crypto_chacha_crypt);
+ 
+-int crypto_xchacha_crypt(struct skcipher_request *req)
++static int crypto_xchacha_crypt(struct skcipher_request *req)
+ {
+ 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+ 	struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
+@@ -75,7 +66,7 @@ int crypto_xchacha_crypt(struct skcipher
+ 	u8 real_iv[16];
+ 
+ 	/* Compute the subkey given the original key and first 128 nonce bits */
+-	crypto_chacha_init(state, ctx, req->iv);
++	chacha_init_generic(state, ctx->key, req->iv);
+ 	hchacha_block_generic(state, subctx.key, ctx->nrounds);
+ 	subctx.nrounds = ctx->nrounds;
+ 
+@@ -86,7 +77,6 @@ int crypto_xchacha_crypt(struct skcipher
+ 	/* Generate the stream and XOR it with the data */
+ 	return chacha_stream_xor(req, &subctx, real_iv);
+ }
+-EXPORT_SYMBOL_GPL(crypto_xchacha_crypt);
+ 
+ static struct skcipher_alg algs[] = {
+ 	{
+--- a/include/crypto/internal/chacha.h
++++ b/include/crypto/internal/chacha.h
+@@ -12,8 +12,6 @@ struct chacha_ctx {
+ 	int nrounds;
+ };
+ 
+-void crypto_chacha_init(u32 *state, const struct chacha_ctx *ctx, const u8 *iv);
+-
+ static inline int chacha_setkey(struct crypto_skcipher *tfm, const u8 *key,
+ 				unsigned int keysize, int nrounds)
+ {
+@@ -42,12 +40,4 @@ static int inline chacha12_setkey(struct
+ 	return chacha_setkey(tfm, key, keysize, 12);
+ }
+ 
+-int crypto_chacha20_setkey(struct crypto_skcipher *tfm, const u8 *key,
+-			   unsigned int keysize);
+-int crypto_chacha12_setkey(struct crypto_skcipher *tfm, const u8 *key,
+-			   unsigned int keysize);
+-
+-int crypto_chacha_crypt(struct skcipher_request *req);
+-int crypto_xchacha_crypt(struct skcipher_request *req);
+-
+ #endif /* _CRYPTO_CHACHA_H */