Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from David Miller:

 1) Add WireGuard

 2) Add HE and TWT support to ath11k driver, from John Crispin.

 3) Add ESP in TCP encapsulation support, from Sabrina Dubroca.

 4) Add variable window congestion control to TIPC, from Jon Maloy.

 5) Add BCM84881 PHY driver, from Russell King.

 6) Start adding netlink support for ethtool operations, from Michal
    Kubecek.

 7) Add XDP drop and TX action support to ena driver, from Sameeh
    Jubran.

 8) Add new ipv4 route notifications so that mlxsw driver does not have
    to handle identical routes itself. From Ido Schimmel.

 9) Add BPF dynamic program extensions, from Alexei Starovoitov.

10) Support RX and TX timestamping in igc, from Vinicius Costa Gomes.

11) Add support for macsec HW offloading, from Antoine Tenart.

12) Add initial support for MPTCP protocol, from Christoph Paasch,
    Matthieu Baerts, Florian Westphal, Peter Krystad, and many others.

13) Add Octeontx2 PF support, from Sunil Goutham, Geetha sowjanya, Linu
    Cherian, and others.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1469 commits)
  net: phy: add default ARCH_BCM_IPROC for MDIO_BCM_IPROC
  udp: segment looped gso packets correctly
  netem: change mailing list
  qed: FW 8.42.2.0 debug features
  qed: rt init valid initialization changed
  qed: Debug feature: ilt and mdump
  qed: FW 8.42.2.0 Add fw overlay feature
  qed: FW 8.42.2.0 HSI changes
  qed: FW 8.42.2.0 iscsi/fcoe changes
  qed: Add abstraction for different hsi values per chip
  qed: FW 8.42.2.0 Additional ll2 type
  qed: Use dmae to write to widebus registers in fw_funcs
  qed: FW 8.42.2.0 Parser offsets modified
  qed: FW 8.42.2.0 Queue Manager changes
  qed: FW 8.42.2.0 Expose new registers and change windows
  qed: FW 8.42.2.0 Internal ram offsets modifications
  MAINTAINERS: Add entry for Marvell OcteonTX2 Physical Function driver
  Documentation: net: octeontx2: Add RVU HW and drivers overview
  octeontx2-pf: ethtool RSS config support
  octeontx2-pf: Add basic ethtool support
  ...

1 files changed, 828 insertions, 0 deletions

diff --git a/drivers/net/wireguard/noise.c b/drivers/net/wireguard/noise.c
new file mode 100644
index 000000000000..d71c8db68a8c
--- /dev/null
+++ b/drivers/net/wireguard/noise.c
@@ -0,0 +1,828 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ */
+
+#include "noise.h"
+#include "device.h"
+#include "peer.h"
+#include "messages.h"
+#include "queueing.h"
+#include "peerlookup.h"
+
+#include <linux/rcupdate.h>
+#include <linux/slab.h>
+#include <linux/bitmap.h>
+#include <linux/scatterlist.h>
+#include <linux/highmem.h>
+#include <crypto/algapi.h>
+
+/* This implements Noise_IKpsk2:
+ *
+ * <- s
+ * ******
+ * -> e, es, s, ss, {t}
+ * <- e, ee, se, psk, {}
+ */
+
+static const u8 handshake_name[37] = "Noise_IKpsk2_25519_ChaChaPoly_BLAKE2s";
+static const u8 identifier_name[34] = "WireGuard v1 zx2c4 Jason@zx2c4.com";
+static u8 handshake_init_hash[NOISE_HASH_LEN] __ro_after_init;
+static u8 handshake_init_chaining_key[NOISE_HASH_LEN] __ro_after_init;
+static atomic64_t keypair_counter = ATOMIC64_INIT(0);
+
+void __init wg_noise_init(void)
+{
+	struct blake2s_state blake;
+
+	blake2s(handshake_init_chaining_key, handshake_name, NULL,
+		NOISE_HASH_LEN, sizeof(handshake_name), 0);
+	blake2s_init(&blake, NOISE_HASH_LEN);
+	blake2s_update(&blake, handshake_init_chaining_key, NOISE_HASH_LEN);
+	blake2s_update(&blake, identifier_name, sizeof(identifier_name));
+	blake2s_final(&blake, handshake_init_hash);
+}
+
+/* Must hold peer->handshake.static_identity->lock */
+bool wg_noise_precompute_static_static(struct wg_peer *peer)
+{
+	bool ret = true;
+
+	down_write(&peer->handshake.lock);
+	if (peer->handshake.static_identity->has_identity)
+		ret = curve25519(
+			peer->handshake.precomputed_static_static,
+			peer->handshake.static_identity->static_private,
+			peer->handshake.remote_static);
+	else
+		memset(peer->handshake.precomputed_static_static, 0,
+		       NOISE_PUBLIC_KEY_LEN);
+	up_write(&peer->handshake.lock);
+	return ret;
+}
+
+bool wg_noise_handshake_init(struct noise_handshake *handshake,
+			   struct noise_static_identity *static_identity,
+			   const u8 peer_public_key[NOISE_PUBLIC_KEY_LEN],
+			   const u8 peer_preshared_key[NOISE_SYMMETRIC_KEY_LEN],
+			   struct wg_peer *peer)
+{
+	memset(handshake, 0, sizeof(*handshake));
+	init_rwsem(&handshake->lock);
+	handshake->entry.type = INDEX_HASHTABLE_HANDSHAKE;
+	handshake->entry.peer = peer;
+	memcpy(handshake->remote_static, peer_public_key, NOISE_PUBLIC_KEY_LEN);
+	if (peer_preshared_key)
+		memcpy(handshake->preshared_key, peer_preshared_key,
+		       NOISE_SYMMETRIC_KEY_LEN);
+	handshake->static_identity = static_identity;
+	handshake->state = HANDSHAKE_ZEROED;
+	return wg_noise_precompute_static_static(peer);
+}
+
+static void handshake_zero(struct noise_handshake *handshake)
+{
+	memset(&handshake->ephemeral_private, 0, NOISE_PUBLIC_KEY_LEN);
+	memset(&handshake->remote_ephemeral, 0, NOISE_PUBLIC_KEY_LEN);
+	memset(&handshake->hash, 0, NOISE_HASH_LEN);
+	memset(&handshake->chaining_key, 0, NOISE_HASH_LEN);
+	handshake->remote_index = 0;
+	handshake->state = HANDSHAKE_ZEROED;
+}
+
+void wg_noise_handshake_clear(struct noise_handshake *handshake)
+{
+	wg_index_hashtable_remove(
+			handshake->entry.peer->device->index_hashtable,
+			&handshake->entry);
+	down_write(&handshake->lock);
+	handshake_zero(handshake);
+	up_write(&handshake->lock);
+	wg_index_hashtable_remove(
+			handshake->entry.peer->device->index_hashtable,
+			&handshake->entry);
+}
+
+static struct noise_keypair *keypair_create(struct wg_peer *peer)
+{
+	struct noise_keypair *keypair = kzalloc(sizeof(*keypair), GFP_KERNEL);
+
+	if (unlikely(!keypair))
+		return NULL;
+	keypair->internal_id = atomic64_inc_return(&keypair_counter);
+	keypair->entry.type = INDEX_HASHTABLE_KEYPAIR;
+	keypair->entry.peer = peer;
+	kref_init(&keypair->refcount);
+	return keypair;
+}
+
+static void keypair_free_rcu(struct rcu_head *rcu)
+{
+	kzfree(container_of(rcu, struct noise_keypair, rcu));
+}
+
+static void keypair_free_kref(struct kref *kref)
+{
+	struct noise_keypair *keypair =
+		container_of(kref, struct noise_keypair, refcount);
+
+	net_dbg_ratelimited("%s: Keypair %llu destroyed for peer %llu\n",
+			    keypair->entry.peer->device->dev->name,
+			    keypair->internal_id,
+			    keypair->entry.peer->internal_id);
+	wg_index_hashtable_remove(keypair->entry.peer->device->index_hashtable,
+				  &keypair->entry);
+	call_rcu(&keypair->rcu, keypair_free_rcu);
+}
+
+void wg_noise_keypair_put(struct noise_keypair *keypair, bool unreference_now)
+{
+	if (unlikely(!keypair))
+		return;
+	if (unlikely(unreference_now))
+		wg_index_hashtable_remove(
+			keypair->entry.peer->device->index_hashtable,
+			&keypair->entry);
+	kref_put(&keypair->refcount, keypair_free_kref);
+}
+
+struct noise_keypair *wg_noise_keypair_get(struct noise_keypair *keypair)
+{
+	RCU_LOCKDEP_WARN(!rcu_read_lock_bh_held(),
+		"Taking noise keypair reference without holding the RCU BH read lock");
+	if (unlikely(!keypair || !kref_get_unless_zero(&keypair->refcount)))
+		return NULL;
+	return keypair;
+}
+
+void wg_noise_keypairs_clear(struct noise_keypairs *keypairs)
+{
+	struct noise_keypair *old;
+
+	spin_lock_bh(&keypairs->keypair_update_lock);
+
+	/* We zero the next_keypair before zeroing the others, so that
+	 * wg_noise_received_with_keypair returns early before subsequent ones
+	 * are zeroed.
+	 */
+	old = rcu_dereference_protected(keypairs->next_keypair,
+		lockdep_is_held(&keypairs->keypair_update_lock));
+	RCU_INIT_POINTER(keypairs->next_keypair, NULL);
+	wg_noise_keypair_put(old, true);
+
+	old = rcu_dereference_protected(keypairs->previous_keypair,
+		lockdep_is_held(&keypairs->keypair_update_lock));
+	RCU_INIT_POINTER(keypairs->previous_keypair, NULL);
+	wg_noise_keypair_put(old, true);
+
+	old = rcu_dereference_protected(keypairs->current_keypair,
+		lockdep_is_held(&keypairs->keypair_update_lock));
+	RCU_INIT_POINTER(keypairs->current_keypair, NULL);
+	wg_noise_keypair_put(old, true);
+
+	spin_unlock_bh(&keypairs->keypair_update_lock);
+}
+
+void wg_noise_expire_current_peer_keypairs(struct wg_peer *peer)
+{
+	struct noise_keypair *keypair;
+
+	wg_noise_handshake_clear(&peer->handshake);
+	wg_noise_reset_last_sent_handshake(&peer->last_sent_handshake);
+
+	spin_lock_bh(&peer->keypairs.keypair_update_lock);
+	keypair = rcu_dereference_protected(peer->keypairs.next_keypair,
+			lockdep_is_held(&peer->keypairs.keypair_update_lock));
+	if (keypair)
+		keypair->sending.is_valid = false;
+	keypair = rcu_dereference_protected(peer->keypairs.current_keypair,
+			lockdep_is_held(&peer->keypairs.keypair_update_lock));
+	if (keypair)
+		keypair->sending.is_valid = false;
+	spin_unlock_bh(&peer->keypairs.keypair_update_lock);
+}
+
+static void add_new_keypair(struct noise_keypairs *keypairs,
+			    struct noise_keypair *new_keypair)
+{
+	struct noise_keypair *previous_keypair, *next_keypair, *current_keypair;
+
+	spin_lock_bh(&keypairs->keypair_update_lock);
+	previous_keypair = rcu_dereference_protected(keypairs->previous_keypair,
+		lockdep_is_held(&keypairs->keypair_update_lock));
+	next_keypair = rcu_dereference_protected(keypairs->next_keypair,
+		lockdep_is_held(&keypairs->keypair_update_lock));
+	current_keypair = rcu_dereference_protected(keypairs->current_keypair,
+		lockdep_is_held(&keypairs->keypair_update_lock));
+	if (new_keypair->i_am_the_initiator) {
+		/* If we're the initiator, it means we've sent a handshake, and
+		 * received a confirmation response, which means this new
+		 * keypair can now be used.
+		 */
+		if (next_keypair) {
+			/* If there already was a next keypair pending, we
+			 * demote it to be the previous keypair, and free the
+			 * existing current. Note that this means KCI can result
+			 * in this transition. It would perhaps be more sound to
+			 * always just get rid of the unused next keypair
+			 * instead of putting it in the previous slot, but this
+			 * might be a bit less robust. Something to think about
+			 * for the future.
+			 */
+			RCU_INIT_POINTER(keypairs->next_keypair, NULL);
+			rcu_assign_pointer(keypairs->previous_keypair,
+					   next_keypair);
+			wg_noise_keypair_put(current_keypair, true);
+		} else /* If there wasn't an existing next keypair, we replace
+			* the previous with the current one.
+			*/
+			rcu_assign_pointer(keypairs->previous_keypair,
+					   current_keypair);
+		/* At this point we can get rid of the old previous keypair, and
+		 * set up the new keypair.
+		 */
+		wg_noise_keypair_put(previous_keypair, true);
+		rcu_assign_pointer(keypairs->current_keypair, new_keypair);
+	} else {
+		/* If we're the responder, it means we can't use the new keypair
+		 * until we receive confirmation via the first data packet, so
+		 * we get rid of the existing previous one, the possibly
+		 * existing next one, and slide in the new next one.
+		 */
+		rcu_assign_pointer(keypairs->next_keypair, new_keypair);
+		wg_noise_keypair_put(next_keypair, true);
+		RCU_INIT_POINTER(keypairs->previous_keypair, NULL);
+		wg_noise_keypair_put(previous_keypair, true);
+	}
+	spin_unlock_bh(&keypairs->keypair_update_lock);
+}
+
+bool wg_noise_received_with_keypair(struct noise_keypairs *keypairs,
+				    struct noise_keypair *received_keypair)
+{
+	struct noise_keypair *old_keypair;
+	bool key_is_new;
+
+	/* We first check without taking the spinlock. */
+	key_is_new = received_keypair ==
+		     rcu_access_pointer(keypairs->next_keypair);
+	if (likely(!key_is_new))
+		return false;
+
+	spin_lock_bh(&keypairs->keypair_update_lock);
+	/* After locking, we double check that things didn't change from
+	 * beneath us.
+	 */
+	if (unlikely(received_keypair !=
+		    rcu_dereference_protected(keypairs->next_keypair,
+			    lockdep_is_held(&keypairs->keypair_update_lock)))) {
+		spin_unlock_bh(&keypairs->keypair_update_lock);
+		return false;
+	}
+
+	/* When we've finally received the confirmation, we slide the next
+	 * into the current, the current into the previous, and get rid of
+	 * the old previous.
+	 */
+	old_keypair = rcu_dereference_protected(keypairs->previous_keypair,
+		lockdep_is_held(&keypairs->keypair_update_lock));
+	rcu_assign_pointer(keypairs->previous_keypair,
+		rcu_dereference_protected(keypairs->current_keypair,
+			lockdep_is_held(&keypairs->keypair_update_lock)));
+	wg_noise_keypair_put(old_keypair, true);
+	rcu_assign_pointer(keypairs->current_keypair, received_keypair);
+	RCU_INIT_POINTER(keypairs->next_keypair, NULL);
+
+	spin_unlock_bh(&keypairs->keypair_update_lock);
+	return true;
+}
+
+/* Must hold static_identity->lock */
+void wg_noise_set_static_identity_private_key(
+	struct noise_static_identity *static_identity,
+	const u8 private_key[NOISE_PUBLIC_KEY_LEN])
+{
+	memcpy(static_identity->static_private, private_key,
+	       NOISE_PUBLIC_KEY_LEN);
+	curve25519_clamp_secret(static_identity->static_private);
+	static_identity->has_identity = curve25519_generate_public(
+		static_identity->static_public, private_key);
+}
+
+/* This is Hugo Krawczyk's HKDF:
+ *  - https://eprint.iacr.org/2010/264.pdf
+ *  - https://tools.ietf.org/html/rfc5869
+ */
+static void kdf(u8 *first_dst, u8 *second_dst, u8 *third_dst, const u8 *data,
+		size_t first_len, size_t second_len, size_t third_len,
+		size_t data_len, const u8 chaining_key[NOISE_HASH_LEN])
+{
+	u8 output[BLAKE2S_HASH_SIZE + 1];
+	u8 secret[BLAKE2S_HASH_SIZE];
+
+	WARN_ON(IS_ENABLED(DEBUG) &&
+		(first_len > BLAKE2S_HASH_SIZE ||
+		 second_len > BLAKE2S_HASH_SIZE ||
+		 third_len > BLAKE2S_HASH_SIZE ||
+		 ((second_len || second_dst || third_len || third_dst) &&
+		  (!first_len || !first_dst)) ||
+		 ((third_len || third_dst) && (!second_len || !second_dst))));
+
+	/* Extract entropy from data into secret */
+	blake2s256_hmac(secret, data, chaining_key, data_len, NOISE_HASH_LEN);
+
+	if (!first_dst || !first_len)
+		goto out;
+
+	/* Expand first key: key = secret, data = 0x1 */
+	output[0] = 1;
+	blake2s256_hmac(output, output, secret, 1, BLAKE2S_HASH_SIZE);
+	memcpy(first_dst, output, first_len);
+
+	if (!second_dst || !second_len)
+		goto out;
+
+	/* Expand second key: key = secret, data = first-key || 0x2 */
+	output[BLAKE2S_HASH_SIZE] = 2;
+	blake2s256_hmac(output, output, secret, BLAKE2S_HASH_SIZE + 1,
+			BLAKE2S_HASH_SIZE);
+	memcpy(second_dst, output, second_len);
+
+	if (!third_dst || !third_len)
+		goto out;
+
+	/* Expand third key: key = secret, data = second-key || 0x3 */
+	output[BLAKE2S_HASH_SIZE] = 3;
+	blake2s256_hmac(output, output, secret, BLAKE2S_HASH_SIZE + 1,
+			BLAKE2S_HASH_SIZE);
+	memcpy(third_dst, output, third_len);
+
+out:
+	/* Clear sensitive data from stack */
+	memzero_explicit(secret, BLAKE2S_HASH_SIZE);
+	memzero_explicit(output, BLAKE2S_HASH_SIZE + 1);
+}
+
+static void symmetric_key_init(struct noise_symmetric_key *key)
+{
+	spin_lock_init(&key->counter.receive.lock);
+	atomic64_set(&key->counter.counter, 0);
+	memset(key->counter.receive.backtrack, 0,
+	       sizeof(key->counter.receive.backtrack));
+	key->birthdate = ktime_get_coarse_boottime_ns();
+	key->is_valid = true;
+}
+
+static void derive_keys(struct noise_symmetric_key *first_dst,
+			struct noise_symmetric_key *second_dst,
+			const u8 chaining_key[NOISE_HASH_LEN])
+{
+	kdf(first_dst->key, second_dst->key, NULL, NULL,
+	    NOISE_SYMMETRIC_KEY_LEN, NOISE_SYMMETRIC_KEY_LEN, 0, 0,
+	    chaining_key);
+	symmetric_key_init(first_dst);
+	symmetric_key_init(second_dst);
+}
+
+static bool __must_check mix_dh(u8 chaining_key[NOISE_HASH_LEN],
+				u8 key[NOISE_SYMMETRIC_KEY_LEN],
+				const u8 private[NOISE_PUBLIC_KEY_LEN],
+				const u8 public[NOISE_PUBLIC_KEY_LEN])
+{
+	u8 dh_calculation[NOISE_PUBLIC_KEY_LEN];
+
+	if (unlikely(!curve25519(dh_calculation, private, public)))
+		return false;
+	kdf(chaining_key, key, NULL, dh_calculation, NOISE_HASH_LEN,
+	    NOISE_SYMMETRIC_KEY_LEN, 0, NOISE_PUBLIC_KEY_LEN, chaining_key);
+	memzero_explicit(dh_calculation, NOISE_PUBLIC_KEY_LEN);
+	return true;
+}
+
+static void mix_hash(u8 hash[NOISE_HASH_LEN], const u8 *src, size_t src_len)
+{
+	struct blake2s_state blake;
+
+	blake2s_init(&blake, NOISE_HASH_LEN);
+	blake2s_update(&blake, hash, NOISE_HASH_LEN);
+	blake2s_update(&blake, src, src_len);
+	blake2s_final(&blake, hash);
+}
+
+static void mix_psk(u8 chaining_key[NOISE_HASH_LEN], u8 hash[NOISE_HASH_LEN],
+		    u8 key[NOISE_SYMMETRIC_KEY_LEN],
+		    const u8 psk[NOISE_SYMMETRIC_KEY_LEN])
+{
+	u8 temp_hash[NOISE_HASH_LEN];
+
+	kdf(chaining_key, temp_hash, key, psk, NOISE_HASH_LEN, NOISE_HASH_LEN,
+	    NOISE_SYMMETRIC_KEY_LEN, NOISE_SYMMETRIC_KEY_LEN, chaining_key);
+	mix_hash(hash, temp_hash, NOISE_HASH_LEN);
+	memzero_explicit(temp_hash, NOISE_HASH_LEN);
+}
+
+static void handshake_init(u8 chaining_key[NOISE_HASH_LEN],
+			   u8 hash[NOISE_HASH_LEN],
+			   const u8 remote_static[NOISE_PUBLIC_KEY_LEN])
+{
+	memcpy(hash, handshake_init_hash, NOISE_HASH_LEN);
+	memcpy(chaining_key, handshake_init_chaining_key, NOISE_HASH_LEN);
+	mix_hash(hash, remote_static, NOISE_PUBLIC_KEY_LEN);
+}
+
+static void message_encrypt(u8 *dst_ciphertext, const u8 *src_plaintext,
+			    size_t src_len, u8 key[NOISE_SYMMETRIC_KEY_LEN],
+			    u8 hash[NOISE_HASH_LEN])
+{
+	chacha20poly1305_encrypt(dst_ciphertext, src_plaintext, src_len, hash,
+				 NOISE_HASH_LEN,
+				 0 /* Always zero for Noise_IK */, key);
+	mix_hash(hash, dst_ciphertext, noise_encrypted_len(src_len));
+}
+
+static bool message_decrypt(u8 *dst_plaintext, const u8 *src_ciphertext,
+			    size_t src_len, u8 key[NOISE_SYMMETRIC_KEY_LEN],
+			    u8 hash[NOISE_HASH_LEN])
+{
+	if (!chacha20poly1305_decrypt(dst_plaintext, src_ciphertext, src_len,
+				      hash, NOISE_HASH_LEN,
+				      0 /* Always zero for Noise_IK */, key))
+		return false;
+	mix_hash(hash, src_ciphertext, src_len);
+	return true;
+}
+
+static void message_ephemeral(u8 ephemeral_dst[NOISE_PUBLIC_KEY_LEN],
+			      const u8 ephemeral_src[NOISE_PUBLIC_KEY_LEN],
+			      u8 chaining_key[NOISE_HASH_LEN],
+			      u8 hash[NOISE_HASH_LEN])
+{
+	if (ephemeral_dst != ephemeral_src)
+		memcpy(ephemeral_dst, ephemeral_src, NOISE_PUBLIC_KEY_LEN);
+	mix_hash(hash, ephemeral_src, NOISE_PUBLIC_KEY_LEN);
+	kdf(chaining_key, NULL, NULL, ephemeral_src, NOISE_HASH_LEN, 0, 0,
+	    NOISE_PUBLIC_KEY_LEN, chaining_key);
+}
+
+static void tai64n_now(u8 output[NOISE_TIMESTAMP_LEN])
+{
+	struct timespec64 now;
+
+	ktime_get_real_ts64(&now);
+
+	/* In order to prevent some sort of infoleak from precise timers, we
+	 * round down the nanoseconds part to the closest rounded-down power of
+	 * two to the maximum initiations per second allowed anyway by the
+	 * implementation.
+	 */
+	now.tv_nsec = ALIGN_DOWN(now.tv_nsec,
+		rounddown_pow_of_two(NSEC_PER_SEC / INITIATIONS_PER_SECOND));
+
+	/* https://cr.yp.to/libtai/tai64.html */
+	*(__be64 *)output = cpu_to_be64(0x400000000000000aULL + now.tv_sec);
+	*(__be32 *)(output + sizeof(__be64)) = cpu_to_be32(now.tv_nsec);
+}
+
+bool
+wg_noise_handshake_create_initiation(struct message_handshake_initiation *dst,
+				     struct noise_handshake *handshake)
+{
+	u8 timestamp[NOISE_TIMESTAMP_LEN];
+	u8 key[NOISE_SYMMETRIC_KEY_LEN];
+	bool ret = false;
+
+	/* We need to wait for crng _before_ taking any locks, since
+	 * curve25519_generate_secret uses get_random_bytes_wait.
+	 */
+	wait_for_random_bytes();
+
+	down_read(&handshake->static_identity->lock);
+	down_write(&handshake->lock);
+
+	if (unlikely(!handshake->static_identity->has_identity))
+		goto out;
+
+	dst->header.type = cpu_to_le32(MESSAGE_HANDSHAKE_INITIATION);
+
+	handshake_init(handshake->chaining_key, handshake->hash,
+		       handshake->remote_static);
+
+	/* e */
+	curve25519_generate_secret(handshake->ephemeral_private);
+	if (!curve25519_generate_public(dst->unencrypted_ephemeral,
+					handshake->ephemeral_private))
+		goto out;
+	message_ephemeral(dst->unencrypted_ephemeral,
+			  dst->unencrypted_ephemeral, handshake->chaining_key,
+			  handshake->hash);
+
+	/* es */
+	if (!mix_dh(handshake->chaining_key, key, handshake->ephemeral_private,
+		    handshake->remote_static))
+		goto out;
+
+	/* s */
+	message_encrypt(dst->encrypted_static,
+			handshake->static_identity->static_public,
+			NOISE_PUBLIC_KEY_LEN, key, handshake->hash);
+
+	/* ss */
+	kdf(handshake->chaining_key, key, NULL,
+	    handshake->precomputed_static_static, NOISE_HASH_LEN,
+	    NOISE_SYMMETRIC_KEY_LEN, 0, NOISE_PUBLIC_KEY_LEN,
+	    handshake->chaining_key);
+
+	/* {t} */
+	tai64n_now(timestamp);
+	message_encrypt(dst->encrypted_timestamp, timestamp,
+			NOISE_TIMESTAMP_LEN, key, handshake->hash);
+
+	dst->sender_index = wg_index_hashtable_insert(
+		handshake->entry.peer->device->index_hashtable,
+		&handshake->entry);
+
+	handshake->state = HANDSHAKE_CREATED_INITIATION;
+	ret = true;
+
+out:
+	up_write(&handshake->lock);
+	up_read(&handshake->static_identity->lock);
+	memzero_explicit(key, NOISE_SYMMETRIC_KEY_LEN);
+	return ret;
+}
+
+struct wg_peer *
+wg_noise_handshake_consume_initiation(struct message_handshake_initiation *src,
+				      struct wg_device *wg)
+{
+	struct wg_peer *peer = NULL, *ret_peer = NULL;
+	struct noise_handshake *handshake;
+	bool replay_attack, flood_attack;
+	u8 key[NOISE_SYMMETRIC_KEY_LEN];
+	u8 chaining_key[NOISE_HASH_LEN];
+	u8 hash[NOISE_HASH_LEN];
+	u8 s[NOISE_PUBLIC_KEY_LEN];
+	u8 e[NOISE_PUBLIC_KEY_LEN];
+	u8 t[NOISE_TIMESTAMP_LEN];
+	u64 initiation_consumption;
+
+	down_read(&wg->static_identity.lock);
+	if (unlikely(!wg->static_identity.has_identity))
+		goto out;
+
+	handshake_init(chaining_key, hash, wg->static_identity.static_public);
+
+	/* e */
+	message_ephemeral(e, src->unencrypted_ephemeral, chaining_key, hash);
+
+	/* es */
+	if (!mix_dh(chaining_key, key, wg->static_identity.static_private, e))
+		goto out;
+
+	/* s */
+	if (!message_decrypt(s, src->encrypted_static,
+			     sizeof(src->encrypted_static), key, hash))
+		goto out;
+
+	/* Lookup which peer we're actually talking to */
+	peer = wg_pubkey_hashtable_lookup(wg->peer_hashtable, s);
+	if (!peer)
+		goto out;
+	handshake = &peer->handshake;
+
+	/* ss */
+	kdf(chaining_key, key, NULL, handshake->precomputed_static_static,
+	    NOISE_HASH_LEN, NOISE_SYMMETRIC_KEY_LEN, 0, NOISE_PUBLIC_KEY_LEN,
+	    chaining_key);
+
+	/* {t} */
+	if (!message_decrypt(t, src->encrypted_timestamp,
+			     sizeof(src->encrypted_timestamp), key, hash))
+		goto out;
+
+	down_read(&handshake->lock);
+	replay_attack = memcmp(t, handshake->latest_timestamp,
+			       NOISE_TIMESTAMP_LEN) <= 0;
+	flood_attack = (s64)handshake->last_initiation_consumption +
+			       NSEC_PER_SEC / INITIATIONS_PER_SECOND >
+		       (s64)ktime_get_coarse_boottime_ns();
+	up_read(&handshake->lock);
+	if (replay_attack || flood_attack)
+		goto out;
+
+	/* Success! Copy everything to peer */
+	down_write(&handshake->lock);
+	memcpy(handshake->remote_ephemeral, e, NOISE_PUBLIC_KEY_LEN);
+	if (memcmp(t, handshake->latest_timestamp, NOISE_TIMESTAMP_LEN) > 0)
+		memcpy(handshake->latest_timestamp, t, NOISE_TIMESTAMP_LEN);
+	memcpy(handshake->hash, hash, NOISE_HASH_LEN);
+	memcpy(handshake->chaining_key, chaining_key, NOISE_HASH_LEN);
+	handshake->remote_index = src->sender_index;
+	if ((s64)(handshake->last_initiation_consumption -
+	    (initiation_consumption = ktime_get_coarse_boottime_ns())) < 0)
+		handshake->last_initiation_consumption = initiation_consumption;
+	handshake->state = HANDSHAKE_CONSUMED_INITIATION;
+	up_write(&handshake->lock);
+	ret_peer = peer;
+
+out:
+	memzero_explicit(key, NOISE_SYMMETRIC_KEY_LEN);
+	memzero_explicit(hash, NOISE_HASH_LEN);
+	memzero_explicit(chaining_key, NOISE_HASH_LEN);
+	up_read(&wg->static_identity.lock);
+	if (!ret_peer)
+		wg_peer_put(peer);
+	return ret_peer;
+}
+
+bool wg_noise_handshake_create_response(struct message_handshake_response *dst,
+					struct noise_handshake *handshake)
+{
+	u8 key[NOISE_SYMMETRIC_KEY_LEN];
+	bool ret = false;
+
+	/* We need to wait for crng _before_ taking any locks, since
+	 * curve25519_generate_secret uses get_random_bytes_wait.
+	 */
+	wait_for_random_bytes();
+
+	down_read(&handshake->static_identity->lock);
+	down_write(&handshake->lock);
+
+	if (handshake->state != HANDSHAKE_CONSUMED_INITIATION)
+		goto out;
+
+	dst->header.type = cpu_to_le32(MESSAGE_HANDSHAKE_RESPONSE);
+	dst->receiver_index = handshake->remote_index;
+
+	/* e */
+	curve25519_generate_secret(handshake->ephemeral_private);
+	if (!curve25519_generate_public(dst->unencrypted_ephemeral,
+					handshake->ephemeral_private))
+		goto out;
+	message_ephemeral(dst->unencrypted_ephemeral,
+			  dst->unencrypted_ephemeral, handshake->chaining_key,
+			  handshake->hash);
+
+	/* ee */
+	if (!mix_dh(handshake->chaining_key, NULL, handshake->ephemeral_private,
+		    handshake->remote_ephemeral))
+		goto out;
+
+	/* se */
+	if (!mix_dh(handshake->chaining_key, NULL, handshake->ephemeral_private,
+		    handshake->remote_static))
+		goto out;
+
+	/* psk */
+	mix_psk(handshake->chaining_key, handshake->hash, key,
+		handshake->preshared_key);
+
+	/* {} */
+	message_encrypt(dst->encrypted_nothing, NULL, 0, key, handshake->hash);
+
+	dst->sender_index = wg_index_hashtable_insert(
+		handshake->entry.peer->device->index_hashtable,
+		&handshake->entry);
+
+	handshake->state = HANDSHAKE_CREATED_RESPONSE;
+	ret = true;
+
+out:
+	up_write(&handshake->lock);
+	up_read(&handshake->static_identity->lock);
+	memzero_explicit(key, NOISE_SYMMETRIC_KEY_LEN);
+	return ret;
+}
+
+struct wg_peer *
+wg_noise_handshake_consume_response(struct message_handshake_response *src,
+				    struct wg_device *wg)
+{
+	enum noise_handshake_state state = HANDSHAKE_ZEROED;
+	struct wg_peer *peer = NULL, *ret_peer = NULL;
+	struct noise_handshake *handshake;
+	u8 key[NOISE_SYMMETRIC_KEY_LEN];
+	u8 hash[NOISE_HASH_LEN];
+	u8 chaining_key[NOISE_HASH_LEN];
+	u8 e[NOISE_PUBLIC_KEY_LEN];
+	u8 ephemeral_private[NOISE_PUBLIC_KEY_LEN];
+	u8 static_private[NOISE_PUBLIC_KEY_LEN];
+
+	down_read(&wg->static_identity.lock);
+
+	if (unlikely(!wg->static_identity.has_identity))
+		goto out;
+
+	handshake = (struct noise_handshake *)wg_index_hashtable_lookup(
+		wg->index_hashtable, INDEX_HASHTABLE_HANDSHAKE,
+		src->receiver_index, &peer);
+	if (unlikely(!handshake))
+		goto out;
+
+	down_read(&handshake->lock);
+	state = handshake->state;
+	memcpy(hash, handshake->hash, NOISE_HASH_LEN);
+	memcpy(chaining_key, handshake->chaining_key, NOISE_HASH_LEN);
+	memcpy(ephemeral_private, handshake->ephemeral_private,
+	       NOISE_PUBLIC_KEY_LEN);
+	up_read(&handshake->lock);
+
+	if (state != HANDSHAKE_CREATED_INITIATION)
+		goto fail;
+
+	/* e */
+	message_ephemeral(e, src->unencrypted_ephemeral, chaining_key, hash);
+
+	/* ee */
+	if (!mix_dh(chaining_key, NULL, ephemeral_private, e))
+		goto fail;
+
+	/* se */
+	if (!mix_dh(chaining_key, NULL, wg->static_identity.static_private, e))
+		goto fail;
+
+	/* psk */
+	mix_psk(chaining_key, hash, key, handshake->preshared_key);
+
+	/* {} */
+	if (!message_decrypt(NULL, src->encrypted_nothing,
+			     sizeof(src->encrypted_nothing), key, hash))
+		goto fail;
+
+	/* Success! Copy everything to peer */
+	down_write(&handshake->lock);
+	/* It's important to check that the state is still the same, while we
+	 * have an exclusive lock.
+	 */
+	if (handshake->state != state) {
+		up_write(&handshake->lock);
+		goto fail;
+	}
+	memcpy(handshake->remote_ephemeral, e, NOISE_PUBLIC_KEY_LEN);
+	memcpy(handshake->hash, hash, NOISE_HASH_LEN);
+	memcpy(handshake->chaining_key, chaining_key, NOISE_HASH_LEN);
+	handshake->remote_index = src->sender_index;
+	handshake->state = HANDSHAKE_CONSUMED_RESPONSE;
+	up_write(&handshake->lock);
+	ret_peer = peer;
+	goto out;
+
+fail:
+	wg_peer_put(peer);
+out:
+	memzero_explicit(key, NOISE_SYMMETRIC_KEY_LEN);
+	memzero_explicit(hash, NOISE_HASH_LEN);
+	memzero_explicit(chaining_key, NOISE_HASH_LEN);
+	memzero_explicit(ephemeral_private, NOISE_PUBLIC_KEY_LEN);
+	memzero_explicit(static_private, NOISE_PUBLIC_KEY_LEN);
+	up_read(&wg->static_identity.lock);
+	return ret_peer;
+}
+
+bool wg_noise_handshake_begin_session(struct noise_handshake *handshake,
+				      struct noise_keypairs *keypairs)
+{
+	struct noise_keypair *new_keypair;
+	bool ret = false;
+
+	down_write(&handshake->lock);
+	if (handshake->state != HANDSHAKE_CREATED_RESPONSE &&
+	    handshake->state != HANDSHAKE_CONSUMED_RESPONSE)
+		goto out;
+
+	new_keypair = keypair_create(handshake->entry.peer);
+	if (!new_keypair)
+		goto out;
+	new_keypair->i_am_the_initiator = handshake->state ==
+					  HANDSHAKE_CONSUMED_RESPONSE;
+	new_keypair->remote_index = handshake->remote_index;
+
+	if (new_keypair->i_am_the_initiator)
+		derive_keys(&new_keypair->sending, &new_keypair->receiving,
+			    handshake->chaining_key);
+	else
+		derive_keys(&new_keypair->receiving, &new_keypair->sending,
+			    handshake->chaining_key);
+
+	handshake_zero(handshake);
+	rcu_read_lock_bh();
+	if (likely(!READ_ONCE(container_of(handshake, struct wg_peer,
+					   handshake)->is_dead))) {
+		add_new_keypair(keypairs, new_keypair);
+		net_dbg_ratelimited("%s: Keypair %llu created for peer %llu\n",
+				    handshake->entry.peer->device->dev->name,
+				    new_keypair->internal_id,
+				    handshake->entry.peer->internal_id);
+		ret = wg_index_hashtable_replace(
+			handshake->entry.peer->device->index_hashtable,
+			&handshake->entry, &new_keypair->entry);
+	} else {
+		kzfree(new_keypair);
+	}
+	rcu_read_unlock_bh();
+
+out:
+	up_write(&handshake->lock);
+	return ret;
+}