Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1487 insertions, 0 deletions

diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
new file mode 100644
index 000000000..184982788
--- /dev/null
+++ b/net/tls/tls_device.c
@@ -0,0 +1,1487 @@
+/* Copyright (c) 2018, Mellanox Technologies All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <crypto/aead.h>
+#include <linux/highmem.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <net/dst.h>
+#include <net/inet_connection_sock.h>
+#include <net/tcp.h>
+#include <net/tls.h>
+
+#include "tls.h"
+#include "trace.h"
+
+/* device_offload_lock is used to synchronize tls_dev_add
+ * against NETDEV_DOWN notifications.
+ */
+static DECLARE_RWSEM(device_offload_lock);
+
+static struct workqueue_struct *destruct_wq __read_mostly;
+
+static LIST_HEAD(tls_device_list);
+static LIST_HEAD(tls_device_down_list);
+static DEFINE_SPINLOCK(tls_device_lock);
+
+static struct page *dummy_page;
+
+static void tls_device_free_ctx(struct tls_context *ctx)
+{
+	if (ctx->tx_conf == TLS_HW) {
+		kfree(tls_offload_ctx_tx(ctx));
+		kfree(ctx->tx.rec_seq);
+		kfree(ctx->tx.iv);
+	}
+
+	if (ctx->rx_conf == TLS_HW)
+		kfree(tls_offload_ctx_rx(ctx));
+
+	tls_ctx_free(NULL, ctx);
+}
+
+static void tls_device_tx_del_task(struct work_struct *work)
+{
+	struct tls_offload_context_tx *offload_ctx =
+		container_of(work, struct tls_offload_context_tx, destruct_work);
+	struct tls_context *ctx = offload_ctx->ctx;
+	struct net_device *netdev;
+
+	/* Safe, because this is the destroy flow, refcount is 0, so
+	 * tls_device_down can't store this field in parallel.
+	 */
+	netdev = rcu_dereference_protected(ctx->netdev,
+					   !refcount_read(&ctx->refcount));
+
+	netdev->tlsdev_ops->tls_dev_del(netdev, ctx, TLS_OFFLOAD_CTX_DIR_TX);
+	dev_put(netdev);
+	ctx->netdev = NULL;
+	tls_device_free_ctx(ctx);
+}
+
+static void tls_device_queue_ctx_destruction(struct tls_context *ctx)
+{
+	struct net_device *netdev;
+	unsigned long flags;
+	bool async_cleanup;
+
+	spin_lock_irqsave(&tls_device_lock, flags);
+	if (unlikely(!refcount_dec_and_test(&ctx->refcount))) {
+		spin_unlock_irqrestore(&tls_device_lock, flags);
+		return;
+	}
+
+	list_del(&ctx->list); /* Remove from tls_device_list / tls_device_down_list */
+
+	/* Safe, because this is the destroy flow, refcount is 0, so
+	 * tls_device_down can't store this field in parallel.
+	 */
+	netdev = rcu_dereference_protected(ctx->netdev,
+					   !refcount_read(&ctx->refcount));
+
+	async_cleanup = netdev && ctx->tx_conf == TLS_HW;
+	if (async_cleanup) {
+		struct tls_offload_context_tx *offload_ctx = tls_offload_ctx_tx(ctx);
+
+		/* queue_work inside the spinlock
+		 * to make sure tls_device_down waits for that work.
+		 */
+		queue_work(destruct_wq, &offload_ctx->destruct_work);
+	}
+	spin_unlock_irqrestore(&tls_device_lock, flags);
+
+	if (!async_cleanup)
+		tls_device_free_ctx(ctx);
+}
+
+/* We assume that the socket is already connected */
+static struct net_device *get_netdev_for_sock(struct sock *sk)
+{
+	struct dst_entry *dst = sk_dst_get(sk);
+	struct net_device *netdev = NULL;
+
+	if (likely(dst)) {
+		netdev = netdev_sk_get_lowest_dev(dst->dev, sk);
+		dev_hold(netdev);
+	}
+
+	dst_release(dst);
+
+	return netdev;
+}
+
+static void destroy_record(struct tls_record_info *record)
+{
+	int i;
+
+	for (i = 0; i < record->num_frags; i++)
+		__skb_frag_unref(&record->frags[i], false);
+	kfree(record);
+}
+
+static void delete_all_records(struct tls_offload_context_tx *offload_ctx)
+{
+	struct tls_record_info *info, *temp;
+
+	list_for_each_entry_safe(info, temp, &offload_ctx->records_list, list) {
+		list_del(&info->list);
+		destroy_record(info);
+	}
+
+	offload_ctx->retransmit_hint = NULL;
+}
+
+static void tls_icsk_clean_acked(struct sock *sk, u32 acked_seq)
+{
+	struct tls_context *tls_ctx = tls_get_ctx(sk);
+	struct tls_record_info *info, *temp;
+	struct tls_offload_context_tx *ctx;
+	u64 deleted_records = 0;
+	unsigned long flags;
+
+	if (!tls_ctx)
+		return;
+
+	ctx = tls_offload_ctx_tx(tls_ctx);
+
+	spin_lock_irqsave(&ctx->lock, flags);
+	info = ctx->retransmit_hint;
+	if (info && !before(acked_seq, info->end_seq))
+		ctx->retransmit_hint = NULL;
+
+	list_for_each_entry_safe(info, temp, &ctx->records_list, list) {
+		if (before(acked_seq, info->end_seq))
+			break;
+		list_del(&info->list);
+
+		destroy_record(info);
+		deleted_records++;
+	}
+
+	ctx->unacked_record_sn += deleted_records;
+	spin_unlock_irqrestore(&ctx->lock, flags);
+}
+
+/* At this point, there should be no references on this
+ * socket and no in-flight SKBs associated with this
+ * socket, so it is safe to free all the resources.
+ */
+void tls_device_sk_destruct(struct sock *sk)
+{
+	struct tls_context *tls_ctx = tls_get_ctx(sk);
+	struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
+
+	tls_ctx->sk_destruct(sk);
+
+	if (tls_ctx->tx_conf == TLS_HW) {
+		if (ctx->open_record)
+			destroy_record(ctx->open_record);
+		delete_all_records(ctx);
+		crypto_free_aead(ctx->aead_send);
+		clean_acked_data_disable(inet_csk(sk));
+	}
+
+	tls_device_queue_ctx_destruction(tls_ctx);
+}
+EXPORT_SYMBOL_GPL(tls_device_sk_destruct);
+
+void tls_device_free_resources_tx(struct sock *sk)
+{
+	struct tls_context *tls_ctx = tls_get_ctx(sk);
+
+	tls_free_partial_record(sk, tls_ctx);
+}
+
+void tls_offload_tx_resync_request(struct sock *sk, u32 got_seq, u32 exp_seq)
+{
+	struct tls_context *tls_ctx = tls_get_ctx(sk);
+
+	trace_tls_device_tx_resync_req(sk, got_seq, exp_seq);
+	WARN_ON(test_and_set_bit(TLS_TX_SYNC_SCHED, &tls_ctx->flags));
+}
+EXPORT_SYMBOL_GPL(tls_offload_tx_resync_request);
+
+static void tls_device_resync_tx(struct sock *sk, struct tls_context *tls_ctx,
+				 u32 seq)
+{
+	struct net_device *netdev;
+	struct sk_buff *skb;
+	int err = 0;
+	u8 *rcd_sn;
+
+	skb = tcp_write_queue_tail(sk);
+	if (skb)
+		TCP_SKB_CB(skb)->eor = 1;
+
+	rcd_sn = tls_ctx->tx.rec_seq;
+
+	trace_tls_device_tx_resync_send(sk, seq, rcd_sn);
+	down_read(&device_offload_lock);
+	netdev = rcu_dereference_protected(tls_ctx->netdev,
+					   lockdep_is_held(&device_offload_lock));
+	if (netdev)
+		err = netdev->tlsdev_ops->tls_dev_resync(netdev, sk, seq,
+							 rcd_sn,
+							 TLS_OFFLOAD_CTX_DIR_TX);
+	up_read(&device_offload_lock);
+	if (err)
+		return;
+
+	clear_bit_unlock(TLS_TX_SYNC_SCHED, &tls_ctx->flags);
+}
+
+static void tls_append_frag(struct tls_record_info *record,
+			    struct page_frag *pfrag,
+			    int size)
+{
+	skb_frag_t *frag;
+
+	frag = &record->frags[record->num_frags - 1];
+	if (skb_frag_page(frag) == pfrag->page &&
+	    skb_frag_off(frag) + skb_frag_size(frag) == pfrag->offset) {
+		skb_frag_size_add(frag, size);
+	} else {
+		++frag;
+		__skb_frag_set_page(frag, pfrag->page);
+		skb_frag_off_set(frag, pfrag->offset);
+		skb_frag_size_set(frag, size);
+		++record->num_frags;
+		get_page(pfrag->page);
+	}
+
+	pfrag->offset += size;
+	record->len += size;
+}
+
+static int tls_push_record(struct sock *sk,
+			   struct tls_context *ctx,
+			   struct tls_offload_context_tx *offload_ctx,
+			   struct tls_record_info *record,
+			   int flags)
+{
+	struct tls_prot_info *prot = &ctx->prot_info;
+	struct tcp_sock *tp = tcp_sk(sk);
+	skb_frag_t *frag;
+	int i;
+
+	record->end_seq = tp->write_seq + record->len;
+	list_add_tail_rcu(&record->list, &offload_ctx->records_list);
+	offload_ctx->open_record = NULL;
+
+	if (test_bit(TLS_TX_SYNC_SCHED, &ctx->flags))
+		tls_device_resync_tx(sk, ctx, tp->write_seq);
+
+	tls_advance_record_sn(sk, prot, &ctx->tx);
+
+	for (i = 0; i < record->num_frags; i++) {
+		frag = &record->frags[i];
+		sg_unmark_end(&offload_ctx->sg_tx_data[i]);
+		sg_set_page(&offload_ctx->sg_tx_data[i], skb_frag_page(frag),
+			    skb_frag_size(frag), skb_frag_off(frag));
+		sk_mem_charge(sk, skb_frag_size(frag));
+		get_page(skb_frag_page(frag));
+	}
+	sg_mark_end(&offload_ctx->sg_tx_data[record->num_frags - 1]);
+
+	/* all ready, send */
+	return tls_push_sg(sk, ctx, offload_ctx->sg_tx_data, 0, flags);
+}
+
+static void tls_device_record_close(struct sock *sk,
+				    struct tls_context *ctx,
+				    struct tls_record_info *record,
+				    struct page_frag *pfrag,
+				    unsigned char record_type)
+{
+	struct tls_prot_info *prot = &ctx->prot_info;
+	struct page_frag dummy_tag_frag;
+
+	/* append tag
+	 * device will fill in the tag, we just need to append a placeholder
+	 * use socket memory to improve coalescing (re-using a single buffer
+	 * increases frag count)
+	 * if we can't allocate memory now use the dummy page
+	 */
+	if (unlikely(pfrag->size - pfrag->offset < prot->tag_size) &&
+	    !skb_page_frag_refill(prot->tag_size, pfrag, sk->sk_allocation)) {
+		dummy_tag_frag.page = dummy_page;
+		dummy_tag_frag.offset = 0;
+		pfrag = &dummy_tag_frag;
+	}
+	tls_append_frag(record, pfrag, prot->tag_size);
+
+	/* fill prepend */
+	tls_fill_prepend(ctx, skb_frag_address(&record->frags[0]),
+			 record->len - prot->overhead_size,
+			 record_type);
+}
+
+static int tls_create_new_record(struct tls_offload_context_tx *offload_ctx,
+				 struct page_frag *pfrag,
+				 size_t prepend_size)
+{
+	struct tls_record_info *record;
+	skb_frag_t *frag;
+
+	record = kmalloc(sizeof(*record), GFP_KERNEL);
+	if (!record)
+		return -ENOMEM;
+
+	frag = &record->frags[0];
+	__skb_frag_set_page(frag, pfrag->page);
+	skb_frag_off_set(frag, pfrag->offset);
+	skb_frag_size_set(frag, prepend_size);
+
+	get_page(pfrag->page);
+	pfrag->offset += prepend_size;
+
+	record->num_frags = 1;
+	record->len = prepend_size;
+	offload_ctx->open_record = record;
+	return 0;
+}
+
+static int tls_do_allocation(struct sock *sk,
+			     struct tls_offload_context_tx *offload_ctx,
+			     struct page_frag *pfrag,
+			     size_t prepend_size)
+{
+	int ret;
+
+	if (!offload_ctx->open_record) {
+		if (unlikely(!skb_page_frag_refill(prepend_size, pfrag,
+						   sk->sk_allocation))) {
+			READ_ONCE(sk->sk_prot)->enter_memory_pressure(sk);
+			sk_stream_moderate_sndbuf(sk);
+			return -ENOMEM;
+		}
+
+		ret = tls_create_new_record(offload_ctx, pfrag, prepend_size);
+		if (ret)
+			return ret;
+
+		if (pfrag->size > pfrag->offset)
+			return 0;
+	}
+
+	if (!sk_page_frag_refill(sk, pfrag))
+		return -ENOMEM;
+
+	return 0;
+}
+
+static int tls_device_copy_data(void *addr, size_t bytes, struct iov_iter *i)
+{
+	size_t pre_copy, nocache;
+
+	pre_copy = ~((unsigned long)addr - 1) & (SMP_CACHE_BYTES - 1);
+	if (pre_copy) {
+		pre_copy = min(pre_copy, bytes);
+		if (copy_from_iter(addr, pre_copy, i) != pre_copy)
+			return -EFAULT;
+		bytes -= pre_copy;
+		addr += pre_copy;
+	}
+
+	nocache = round_down(bytes, SMP_CACHE_BYTES);
+	if (copy_from_iter_nocache(addr, nocache, i) != nocache)
+		return -EFAULT;
+	bytes -= nocache;
+	addr += nocache;
+
+	if (bytes && copy_from_iter(addr, bytes, i) != bytes)
+		return -EFAULT;
+
+	return 0;
+}
+
+union tls_iter_offset {
+	struct iov_iter *msg_iter;
+	int offset;
+};
+
+static int tls_push_data(struct sock *sk,
+			 union tls_iter_offset iter_offset,
+			 size_t size, int flags,
+			 unsigned char record_type,
+			 struct page *zc_page)
+{
+	struct tls_context *tls_ctx = tls_get_ctx(sk);
+	struct tls_prot_info *prot = &tls_ctx->prot_info;
+	struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
+	struct tls_record_info *record;
+	int tls_push_record_flags;
+	struct page_frag *pfrag;
+	size_t orig_size = size;
+	u32 max_open_record_len;
+	bool more = false;
+	bool done = false;
+	int copy, rc = 0;
+	long timeo;
+
+	if (flags &
+	    ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL | MSG_SENDPAGE_NOTLAST))
+		return -EOPNOTSUPP;
+
+	if (unlikely(sk->sk_err))
+		return -sk->sk_err;
+
+	flags |= MSG_SENDPAGE_DECRYPTED;
+	tls_push_record_flags = flags | MSG_SENDPAGE_NOTLAST;
+
+	timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
+	if (tls_is_partially_sent_record(tls_ctx)) {
+		rc = tls_push_partial_record(sk, tls_ctx, flags);
+		if (rc < 0)
+			return rc;
+	}
+
+	pfrag = sk_page_frag(sk);
+
+	/* TLS_HEADER_SIZE is not counted as part of the TLS record, and
+	 * we need to leave room for an authentication tag.
+	 */
+	max_open_record_len = TLS_MAX_PAYLOAD_SIZE +
+			      prot->prepend_size;
+	do {
+		rc = tls_do_allocation(sk, ctx, pfrag, prot->prepend_size);
+		if (unlikely(rc)) {
+			rc = sk_stream_wait_memory(sk, &timeo);
+			if (!rc)
+				continue;
+
+			record = ctx->open_record;
+			if (!record)
+				break;
+handle_error:
+			if (record_type != TLS_RECORD_TYPE_DATA) {
+				/* avoid sending partial
+				 * record with type !=
+				 * application_data
+				 */
+				size = orig_size;
+				destroy_record(record);
+				ctx->open_record = NULL;
+			} else if (record->len > prot->prepend_size) {
+				goto last_record;
+			}
+
+			break;
+		}
+
+		record = ctx->open_record;
+
+		copy = min_t(size_t, size, max_open_record_len - record->len);
+		if (copy && zc_page) {
+			struct page_frag zc_pfrag;
+
+			zc_pfrag.page = zc_page;
+			zc_pfrag.offset = iter_offset.offset;
+			zc_pfrag.size = copy;
+			tls_append_frag(record, &zc_pfrag, copy);
+
+			iter_offset.offset += copy;
+		} else if (copy) {
+			copy = min_t(size_t, copy, pfrag->size - pfrag->offset);
+
+			rc = tls_device_copy_data(page_address(pfrag->page) +
+						  pfrag->offset, copy,
+						  iter_offset.msg_iter);
+			if (rc)
+				goto handle_error;
+			tls_append_frag(record, pfrag, copy);
+		}
+
+		size -= copy;
+		if (!size) {
+last_record:
+			tls_push_record_flags = flags;
+			if (flags & (MSG_SENDPAGE_NOTLAST | MSG_MORE)) {
+				more = true;
+				break;
+			}
+
+			done = true;
+		}
+
+		if (done || record->len >= max_open_record_len ||
+		    (record->num_frags >= MAX_SKB_FRAGS - 1)) {
+			tls_device_record_close(sk, tls_ctx, record,
+						pfrag, record_type);
+
+			rc = tls_push_record(sk,
+					     tls_ctx,
+					     ctx,
+					     record,
+					     tls_push_record_flags);
+			if (rc < 0)
+				break;
+		}
+	} while (!done);
+
+	tls_ctx->pending_open_record_frags = more;
+
+	if (orig_size - size > 0)
+		rc = orig_size - size;
+
+	return rc;
+}
+
+int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
+{
+	unsigned char record_type = TLS_RECORD_TYPE_DATA;
+	struct tls_context *tls_ctx = tls_get_ctx(sk);
+	union tls_iter_offset iter;
+	int rc;
+
+	mutex_lock(&tls_ctx->tx_lock);
+	lock_sock(sk);
+
+	if (unlikely(msg->msg_controllen)) {
+		rc = tls_process_cmsg(sk, msg, &record_type);
+		if (rc)
+			goto out;
+	}
+
+	iter.msg_iter = &msg->msg_iter;
+	rc = tls_push_data(sk, iter, size, msg->msg_flags, record_type, NULL);
+
+out:
+	release_sock(sk);
+	mutex_unlock(&tls_ctx->tx_lock);
+	return rc;
+}
+
+int tls_device_sendpage(struct sock *sk, struct page *page,
+			int offset, size_t size, int flags)
+{
+	struct tls_context *tls_ctx = tls_get_ctx(sk);
+	union tls_iter_offset iter_offset;
+	struct iov_iter msg_iter;
+	char *kaddr;
+	struct kvec iov;
+	int rc;
+
+	if (flags & MSG_SENDPAGE_NOTLAST)
+		flags |= MSG_MORE;
+
+	mutex_lock(&tls_ctx->tx_lock);
+	lock_sock(sk);
+
+	if (flags & MSG_OOB) {
+		rc = -EOPNOTSUPP;
+		goto out;
+	}
+
+	if (tls_ctx->zerocopy_sendfile) {
+		iter_offset.offset = offset;
+		rc = tls_push_data(sk, iter_offset, size,
+				   flags, TLS_RECORD_TYPE_DATA, page);
+		goto out;
+	}
+
+	kaddr = kmap(page);
+	iov.iov_base = kaddr + offset;
+	iov.iov_len = size;
+	iov_iter_kvec(&msg_iter, ITER_SOURCE, &iov, 1, size);
+	iter_offset.msg_iter = &msg_iter;
+	rc = tls_push_data(sk, iter_offset, size, flags, TLS_RECORD_TYPE_DATA,
+			   NULL);
+	kunmap(page);
+
+out:
+	release_sock(sk);
+	mutex_unlock(&tls_ctx->tx_lock);
+	return rc;
+}
+
+struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context,
+				       u32 seq, u64 *p_record_sn)
+{
+	u64 record_sn = context->hint_record_sn;
+	struct tls_record_info *info, *last;
+
+	info = context->retransmit_hint;
+	if (!info ||
+	    before(seq, info->end_seq - info->len)) {
+		/* if retransmit_hint is irrelevant start
+		 * from the beginning of the list
+		 */
+		info = list_first_entry_or_null(&context->records_list,
+						struct tls_record_info, list);
+		if (!info)
+			return NULL;
+		/* send the start_marker record if seq number is before the
+		 * tls offload start marker sequence number. This record is
+		 * required to handle TCP packets which are before TLS offload
+		 * started.
+		 *  And if it's not start marker, look if this seq number
+		 * belongs to the list.
+		 */
+		if (likely(!tls_record_is_start_marker(info))) {
+			/* we have the first record, get the last record to see
+			 * if this seq number belongs to the list.
+			 */
+			last = list_last_entry(&context->records_list,
+					       struct tls_record_info, list);
+
+			if (!between(seq, tls_record_start_seq(info),
+				     last->end_seq))
+				return NULL;
+		}
+		record_sn = context->unacked_record_sn;
+	}
+
+	/* We just need the _rcu for the READ_ONCE() */
+	rcu_read_lock();
+	list_for_each_entry_from_rcu(info, &context->records_list, list) {
+		if (before(seq, info->end_seq)) {
+			if (!context->retransmit_hint ||
+			    after(info->end_seq,
+				  context->retransmit_hint->end_seq)) {
+				context->hint_record_sn = record_sn;
+				context->retransmit_hint = info;
+			}
+			*p_record_sn = record_sn;
+			goto exit_rcu_unlock;
+		}
+		record_sn++;
+	}
+	info = NULL;
+
+exit_rcu_unlock:
+	rcu_read_unlock();
+	return info;
+}
+EXPORT_SYMBOL(tls_get_record);
+
+static int tls_device_push_pending_record(struct sock *sk, int flags)
+{
+	union tls_iter_offset iter;
+	struct iov_iter msg_iter;
+
+	iov_iter_kvec(&msg_iter, ITER_SOURCE, NULL, 0, 0);
+	iter.msg_iter = &msg_iter;
+	return tls_push_data(sk, iter, 0, flags, TLS_RECORD_TYPE_DATA, NULL);
+}
+
+void tls_device_write_space(struct sock *sk, struct tls_context *ctx)
+{
+	if (tls_is_partially_sent_record(ctx)) {
+		gfp_t sk_allocation = sk->sk_allocation;
+
+		WARN_ON_ONCE(sk->sk_write_pending);
+
+		sk->sk_allocation = GFP_ATOMIC;
+		tls_push_partial_record(sk, ctx,
+					MSG_DONTWAIT | MSG_NOSIGNAL |
+					MSG_SENDPAGE_DECRYPTED);
+		sk->sk_allocation = sk_allocation;
+	}
+}
+
+static void tls_device_resync_rx(struct tls_context *tls_ctx,
+				 struct sock *sk, u32 seq, u8 *rcd_sn)
+{
+	struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
+	struct net_device *netdev;
+
+	trace_tls_device_rx_resync_send(sk, seq, rcd_sn, rx_ctx->resync_type);
+	rcu_read_lock();
+	netdev = rcu_dereference(tls_ctx->netdev);
+	if (netdev)
+		netdev->tlsdev_ops->tls_dev_resync(netdev, sk, seq, rcd_sn,
+						   TLS_OFFLOAD_CTX_DIR_RX);
+	rcu_read_unlock();
+	TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSRXDEVICERESYNC);
+}
+
+static bool
+tls_device_rx_resync_async(struct tls_offload_resync_async *resync_async,
+			   s64 resync_req, u32 *seq, u16 *rcd_delta)
+{
+	u32 is_async = resync_req & RESYNC_REQ_ASYNC;
+	u32 req_seq = resync_req >> 32;
+	u32 req_end = req_seq + ((resync_req >> 16) & 0xffff);
+	u16 i;
+
+	*rcd_delta = 0;
+
+	if (is_async) {
+		/* shouldn't get to wraparound:
+		 * too long in async stage, something bad happened
+		 */
+		if (WARN_ON_ONCE(resync_async->rcd_delta == USHRT_MAX))
+			return false;
+
+		/* asynchronous stage: log all headers seq such that
+		 * req_seq <= seq <= end_seq, and wait for real resync request
+		 */
+		if (before(*seq, req_seq))
+			return false;
+		if (!after(*seq, req_end) &&
+		    resync_async->loglen < TLS_DEVICE_RESYNC_ASYNC_LOGMAX)
+			resync_async->log[resync_async->loglen++] = *seq;
+
+		resync_async->rcd_delta++;
+
+		return false;
+	}
+
+	/* synchronous stage: check against the logged entries and
+	 * proceed to check the next entries if no match was found
+	 */
+	for (i = 0; i < resync_async->loglen; i++)
+		if (req_seq == resync_async->log[i] &&
+		    atomic64_try_cmpxchg(&resync_async->req, &resync_req, 0)) {
+			*rcd_delta = resync_async->rcd_delta - i;
+			*seq = req_seq;
+			resync_async->loglen = 0;
+			resync_async->rcd_delta = 0;
+			return true;
+		}
+
+	resync_async->loglen = 0;
+	resync_async->rcd_delta = 0;
+
+	if (req_seq == *seq &&
+	    atomic64_try_cmpxchg(&resync_async->req,
+				 &resync_req, 0))
+		return true;
+
+	return false;
+}
+
+void tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq)
+{
+	struct tls_context *tls_ctx = tls_get_ctx(sk);
+	struct tls_offload_context_rx *rx_ctx;
+	u8 rcd_sn[TLS_MAX_REC_SEQ_SIZE];
+	u32 sock_data, is_req_pending;
+	struct tls_prot_info *prot;
+	s64 resync_req;
+	u16 rcd_delta;
+	u32 req_seq;
+
+	if (tls_ctx->rx_conf != TLS_HW)
+		return;
+	if (unlikely(test_bit(TLS_RX_DEV_DEGRADED, &tls_ctx->flags)))
+		return;
+
+	prot = &tls_ctx->prot_info;
+	rx_ctx = tls_offload_ctx_rx(tls_ctx);
+	memcpy(rcd_sn, tls_ctx->rx.rec_seq, prot->rec_seq_size);
+
+	switch (rx_ctx->resync_type) {
+	case TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ:
+		resync_req = atomic64_read(&rx_ctx->resync_req);
+		req_seq = resync_req >> 32;
+		seq += TLS_HEADER_SIZE - 1;
+		is_req_pending = resync_req;
+
+		if (likely(!is_req_pending) || req_seq != seq ||
+		    !atomic64_try_cmpxchg(&rx_ctx->resync_req, &resync_req, 0))
+			return;
+		break;
+	case TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT:
+		if (likely(!rx_ctx->resync_nh_do_now))
+			return;
+
+		/* head of next rec is already in, note that the sock_inq will
+		 * include the currently parsed message when called from parser
+		 */
+		sock_data = tcp_inq(sk);
+		if (sock_data > rcd_len) {
+			trace_tls_device_rx_resync_nh_delay(sk, sock_data,
+							    rcd_len);
+			return;
+		}
+
+		rx_ctx->resync_nh_do_now = 0;
+		seq += rcd_len;
+		tls_bigint_increment(rcd_sn, prot->rec_seq_size);
+		break;
+	case TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ_ASYNC:
+		resync_req = atomic64_read(&rx_ctx->resync_async->req);
+		is_req_pending = resync_req;
+		if (likely(!is_req_pending))
+			return;
+
+		if (!tls_device_rx_resync_async(rx_ctx->resync_async,
+						resync_req, &seq, &rcd_delta))
+			return;
+		tls_bigint_subtract(rcd_sn, rcd_delta);
+		break;
+	}
+
+	tls_device_resync_rx(tls_ctx, sk, seq, rcd_sn);
+}
+
+static void tls_device_core_ctrl_rx_resync(struct tls_context *tls_ctx,
+					   struct tls_offload_context_rx *ctx,
+					   struct sock *sk, struct sk_buff *skb)
+{
+	struct strp_msg *rxm;
+
+	/* device will request resyncs by itself based on stream scan */
+	if (ctx->resync_type != TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT)
+		return;
+	/* already scheduled */
+	if (ctx->resync_nh_do_now)
+		return;
+	/* seen decrypted fragments since last fully-failed record */
+	if (ctx->resync_nh_reset) {
+		ctx->resync_nh_reset = 0;
+		ctx->resync_nh.decrypted_failed = 1;
+		ctx->resync_nh.decrypted_tgt = TLS_DEVICE_RESYNC_NH_START_IVAL;
+		return;
+	}
+
+	if (++ctx->resync_nh.decrypted_failed <= ctx->resync_nh.decrypted_tgt)
+		return;
+
+	/* doing resync, bump the next target in case it fails */
+	if (ctx->resync_nh.decrypted_tgt < TLS_DEVICE_RESYNC_NH_MAX_IVAL)
+		ctx->resync_nh.decrypted_tgt *= 2;
+	else
+		ctx->resync_nh.decrypted_tgt += TLS_DEVICE_RESYNC_NH_MAX_IVAL;
+
+	rxm = strp_msg(skb);
+
+	/* head of next rec is already in, parser will sync for us */
+	if (tcp_inq(sk) > rxm->full_len) {
+		trace_tls_device_rx_resync_nh_schedule(sk);
+		ctx->resync_nh_do_now = 1;
+	} else {
+		struct tls_prot_info *prot = &tls_ctx->prot_info;
+		u8 rcd_sn[TLS_MAX_REC_SEQ_SIZE];
+
+		memcpy(rcd_sn, tls_ctx->rx.rec_seq, prot->rec_seq_size);
+		tls_bigint_increment(rcd_sn, prot->rec_seq_size);
+
+		tls_device_resync_rx(tls_ctx, sk, tcp_sk(sk)->copied_seq,
+				     rcd_sn);
+	}
+}
+
+static int
+tls_device_reencrypt(struct sock *sk, struct tls_context *tls_ctx)
+{
+	struct tls_sw_context_rx *sw_ctx = tls_sw_ctx_rx(tls_ctx);
+	const struct tls_cipher_size_desc *cipher_sz;
+	int err, offset, copy, data_len, pos;
+	struct sk_buff *skb, *skb_iter;
+	struct scatterlist sg[1];
+	struct strp_msg *rxm;
+	char *orig_buf, *buf;
+
+	switch (tls_ctx->crypto_recv.info.cipher_type) {
+	case TLS_CIPHER_AES_GCM_128:
+	case TLS_CIPHER_AES_GCM_256:
+		break;
+	default:
+		return -EINVAL;
+	}
+	cipher_sz = &tls_cipher_size_desc[tls_ctx->crypto_recv.info.cipher_type];
+
+	rxm = strp_msg(tls_strp_msg(sw_ctx));
+	orig_buf = kmalloc(rxm->full_len + TLS_HEADER_SIZE + cipher_sz->iv,
+			   sk->sk_allocation);
+	if (!orig_buf)
+		return -ENOMEM;
+	buf = orig_buf;
+
+	err = tls_strp_msg_cow(sw_ctx);
+	if (unlikely(err))
+		goto free_buf;
+
+	skb = tls_strp_msg(sw_ctx);
+	rxm = strp_msg(skb);
+	offset = rxm->offset;
+
+	sg_init_table(sg, 1);
+	sg_set_buf(&sg[0], buf,
+		   rxm->full_len + TLS_HEADER_SIZE + cipher_sz->iv);
+	err = skb_copy_bits(skb, offset, buf, TLS_HEADER_SIZE + cipher_sz->iv);
+	if (err)
+		goto free_buf;
+
+	/* We are interested only in the decrypted data not the auth */
+	err = decrypt_skb(sk, sg);
+	if (err != -EBADMSG)
+		goto free_buf;
+	else
+		err = 0;
+
+	data_len = rxm->full_len - cipher_sz->tag;
+
+	if (skb_pagelen(skb) > offset) {
+		copy = min_t(int, skb_pagelen(skb) - offset, data_len);
+
+		if (skb->decrypted) {
+			err = skb_store_bits(skb, offset, buf, copy);
+			if (err)
+				goto free_buf;
+		}
+
+		offset += copy;
+		buf += copy;
+	}
+
+	pos = skb_pagelen(skb);
+	skb_walk_frags(skb, skb_iter) {
+		int frag_pos;
+
+		/* Practically all frags must belong to msg if reencrypt
+		 * is needed with current strparser and coalescing logic,
+		 * but strparser may "get optimized", so let's be safe.
+		 */
+		if (pos + skb_iter->len <= offset)
+			goto done_with_frag;
+		if (pos >= data_len + rxm->offset)
+			break;
+
+		frag_pos = offset - pos;
+		copy = min_t(int, skb_iter->len - frag_pos,
+			     data_len + rxm->offset - offset);
+
+		if (skb_iter->decrypted) {
+			err = skb_store_bits(skb_iter, frag_pos, buf, copy);
+			if (err)
+				goto free_buf;
+		}
+
+		offset += copy;
+		buf += copy;
+done_with_frag:
+		pos += skb_iter->len;
+	}
+
+free_buf:
+	kfree(orig_buf);
+	return err;
+}
+
+int tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx)
+{
+	struct tls_offload_context_rx *ctx = tls_offload_ctx_rx(tls_ctx);
+	struct tls_sw_context_rx *sw_ctx = tls_sw_ctx_rx(tls_ctx);
+	struct sk_buff *skb = tls_strp_msg(sw_ctx);
+	struct strp_msg *rxm = strp_msg(skb);
+	int is_decrypted, is_encrypted;
+
+	if (!tls_strp_msg_mixed_decrypted(sw_ctx)) {
+		is_decrypted = skb->decrypted;
+		is_encrypted = !is_decrypted;
+	} else {
+		is_decrypted = 0;
+		is_encrypted = 0;
+	}
+
+	trace_tls_device_decrypted(sk, tcp_sk(sk)->copied_seq - rxm->full_len,
+				   tls_ctx->rx.rec_seq, rxm->full_len,
+				   is_encrypted, is_decrypted);
+
+	if (unlikely(test_bit(TLS_RX_DEV_DEGRADED, &tls_ctx->flags))) {
+		if (likely(is_encrypted || is_decrypted))
+			return is_decrypted;
+
+		/* After tls_device_down disables the offload, the next SKB will
+		 * likely have initial fragments decrypted, and final ones not
+		 * decrypted. We need to reencrypt that single SKB.
+		 */
+		return tls_device_reencrypt(sk, tls_ctx);
+	}
+
+	/* Return immediately if the record is either entirely plaintext or
+	 * entirely ciphertext. Otherwise handle reencrypt partially decrypted
+	 * record.
+	 */
+	if (is_decrypted) {
+		ctx->resync_nh_reset = 1;
+		return is_decrypted;
+	}
+	if (is_encrypted) {
+		tls_device_core_ctrl_rx_resync(tls_ctx, ctx, sk, skb);
+		return 0;
+	}
+
+	ctx->resync_nh_reset = 1;
+	return tls_device_reencrypt(sk, tls_ctx);
+}
+
+static void tls_device_attach(struct tls_context *ctx, struct sock *sk,
+			      struct net_device *netdev)
+{
+	if (sk->sk_destruct != tls_device_sk_destruct) {
+		refcount_set(&ctx->refcount, 1);
+		dev_hold(netdev);
+		RCU_INIT_POINTER(ctx->netdev, netdev);
+		spin_lock_irq(&tls_device_lock);
+		list_add_tail(&ctx->list, &tls_device_list);
+		spin_unlock_irq(&tls_device_lock);
+
+		ctx->sk_destruct = sk->sk_destruct;
+		smp_store_release(&sk->sk_destruct, tls_device_sk_destruct);
+	}
+}
+
+int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
+{
+	struct tls_context *tls_ctx = tls_get_ctx(sk);
+	struct tls_prot_info *prot = &tls_ctx->prot_info;
+	const struct tls_cipher_size_desc *cipher_sz;
+	struct tls_record_info *start_marker_record;
+	struct tls_offload_context_tx *offload_ctx;
+	struct tls_crypto_info *crypto_info;
+	struct net_device *netdev;
+	char *iv, *rec_seq;
+	struct sk_buff *skb;
+	__be64 rcd_sn;
+	int rc;
+
+	if (!ctx)
+		return -EINVAL;
+
+	if (ctx->priv_ctx_tx)
+		return -EEXIST;
+
+	netdev = get_netdev_for_sock(sk);
+	if (!netdev) {
+		pr_err_ratelimited("%s: netdev not found\n", __func__);
+		return -EINVAL;
+	}
+
+	if (!(netdev->features & NETIF_F_HW_TLS_TX)) {
+		rc = -EOPNOTSUPP;
+		goto release_netdev;
+	}
+
+	crypto_info = &ctx->crypto_send.info;
+	if (crypto_info->version != TLS_1_2_VERSION) {
+		rc = -EOPNOTSUPP;
+		goto release_netdev;
+	}
+
+	switch (crypto_info->cipher_type) {
+	case TLS_CIPHER_AES_GCM_128:
+		iv = ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->iv;
+		rec_seq =
+		 ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->rec_seq;
+		break;
+	case TLS_CIPHER_AES_GCM_256:
+		iv = ((struct tls12_crypto_info_aes_gcm_256 *)crypto_info)->iv;
+		rec_seq =
+		 ((struct tls12_crypto_info_aes_gcm_256 *)crypto_info)->rec_seq;
+		break;
+	default:
+		rc = -EINVAL;
+		goto release_netdev;
+	}
+	cipher_sz = &tls_cipher_size_desc[crypto_info->cipher_type];
+
+	/* Sanity-check the rec_seq_size for stack allocations */
+	if (cipher_sz->rec_seq > TLS_MAX_REC_SEQ_SIZE) {
+		rc = -EINVAL;
+		goto release_netdev;
+	}
+
+	prot->version = crypto_info->version;
+	prot->cipher_type = crypto_info->cipher_type;
+	prot->prepend_size = TLS_HEADER_SIZE + cipher_sz->iv;
+	prot->tag_size = cipher_sz->tag;
+	prot->overhead_size = prot->prepend_size + prot->tag_size;
+	prot->iv_size = cipher_sz->iv;
+	prot->salt_size = cipher_sz->salt;
+	ctx->tx.iv = kmalloc(cipher_sz->iv + cipher_sz->salt, GFP_KERNEL);
+	if (!ctx->tx.iv) {
+		rc = -ENOMEM;
+		goto release_netdev;
+	}
+
+	memcpy(ctx->tx.iv + cipher_sz->salt, iv, cipher_sz->iv);
+
+	prot->rec_seq_size = cipher_sz->rec_seq;
+	ctx->tx.rec_seq = kmemdup(rec_seq, cipher_sz->rec_seq, GFP_KERNEL);
+	if (!ctx->tx.rec_seq) {
+		rc = -ENOMEM;
+		goto free_iv;
+	}
+
+	start_marker_record = kmalloc(sizeof(*start_marker_record), GFP_KERNEL);
+	if (!start_marker_record) {
+		rc = -ENOMEM;
+		goto free_rec_seq;
+	}
+
+	offload_ctx = kzalloc(TLS_OFFLOAD_CONTEXT_SIZE_TX, GFP_KERNEL);
+	if (!offload_ctx) {
+		rc = -ENOMEM;
+		goto free_marker_record;
+	}
+
+	rc = tls_sw_fallback_init(sk, offload_ctx, crypto_info);
+	if (rc)
+		goto free_offload_ctx;
+
+	/* start at rec_seq - 1 to account for the start marker record */
+	memcpy(&rcd_sn, ctx->tx.rec_seq, sizeof(rcd_sn));
+	offload_ctx->unacked_record_sn = be64_to_cpu(rcd_sn) - 1;
+
+	start_marker_record->end_seq = tcp_sk(sk)->write_seq;
+	start_marker_record->len = 0;
+	start_marker_record->num_frags = 0;
+
+	INIT_WORK(&offload_ctx->destruct_work, tls_device_tx_del_task);
+	offload_ctx->ctx = ctx;
+
+	INIT_LIST_HEAD(&offload_ctx->records_list);
+	list_add_tail(&start_marker_record->list, &offload_ctx->records_list);
+	spin_lock_init(&offload_ctx->lock);
+	sg_init_table(offload_ctx->sg_tx_data,
+		      ARRAY_SIZE(offload_ctx->sg_tx_data));
+
+	clean_acked_data_enable(inet_csk(sk), &tls_icsk_clean_acked);
+	ctx->push_pending_record = tls_device_push_pending_record;
+
+	/* TLS offload is greatly simplified if we don't send
+	 * SKBs where only part of the payload needs to be encrypted.
+	 * So mark the last skb in the write queue as end of record.
+	 */
+	skb = tcp_write_queue_tail(sk);
+	if (skb)
+		TCP_SKB_CB(skb)->eor = 1;
+
+	/* Avoid offloading if the device is down
+	 * We don't want to offload new flows after
+	 * the NETDEV_DOWN event
+	 *
+	 * device_offload_lock is taken in tls_devices's NETDEV_DOWN
+	 * handler thus protecting from the device going down before
+	 * ctx was added to tls_device_list.
+	 */
+	down_read(&device_offload_lock);
+	if (!(netdev->flags & IFF_UP)) {
+		rc = -EINVAL;
+		goto release_lock;
+	}
+
+	ctx->priv_ctx_tx = offload_ctx;
+	rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_TX,
+					     &ctx->crypto_send.info,
+					     tcp_sk(sk)->write_seq);
+	trace_tls_device_offload_set(sk, TLS_OFFLOAD_CTX_DIR_TX,
+				     tcp_sk(sk)->write_seq, rec_seq, rc);
+	if (rc)
+		goto release_lock;
+
+	tls_device_attach(ctx, sk, netdev);
+	up_read(&device_offload_lock);
+
+	/* following this assignment tls_is_sk_tx_device_offloaded
+	 * will return true and the context might be accessed
+	 * by the netdev's xmit function.
+	 */
+	smp_store_release(&sk->sk_validate_xmit_skb, tls_validate_xmit_skb);
+	dev_put(netdev);
+
+	return 0;
+
+release_lock:
+	up_read(&device_offload_lock);
+	clean_acked_data_disable(inet_csk(sk));
+	crypto_free_aead(offload_ctx->aead_send);
+free_offload_ctx:
+	kfree(offload_ctx);
+	ctx->priv_ctx_tx = NULL;
+free_marker_record:
+	kfree(start_marker_record);
+free_rec_seq:
+	kfree(ctx->tx.rec_seq);
+free_iv:
+	kfree(ctx->tx.iv);
+release_netdev:
+	dev_put(netdev);
+	return rc;
+}
+
+int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
+{
+	struct tls12_crypto_info_aes_gcm_128 *info;
+	struct tls_offload_context_rx *context;
+	struct net_device *netdev;
+	int rc = 0;
+
+	if (ctx->crypto_recv.info.version != TLS_1_2_VERSION)
+		return -EOPNOTSUPP;
+
+	netdev = get_netdev_for_sock(sk);
+	if (!netdev) {
+		pr_err_ratelimited("%s: netdev not found\n", __func__);
+		return -EINVAL;
+	}
+
+	if (!(netdev->features & NETIF_F_HW_TLS_RX)) {
+		rc = -EOPNOTSUPP;
+		goto release_netdev;
+	}
+
+	/* Avoid offloading if the device is down
+	 * We don't want to offload new flows after
+	 * the NETDEV_DOWN event
+	 *
+	 * device_offload_lock is taken in tls_devices's NETDEV_DOWN
+	 * handler thus protecting from the device going down before
+	 * ctx was added to tls_device_list.
+	 */
+	down_read(&device_offload_lock);
+	if (!(netdev->flags & IFF_UP)) {
+		rc = -EINVAL;
+		goto release_lock;
+	}
+
+	context = kzalloc(TLS_OFFLOAD_CONTEXT_SIZE_RX, GFP_KERNEL);
+	if (!context) {
+		rc = -ENOMEM;
+		goto release_lock;
+	}
+	context->resync_nh_reset = 1;
+
+	ctx->priv_ctx_rx = context;
+	rc = tls_set_sw_offload(sk, ctx, 0);
+	if (rc)
+		goto release_ctx;
+
+	rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_RX,
+					     &ctx->crypto_recv.info,
+					     tcp_sk(sk)->copied_seq);
+	info = (void *)&ctx->crypto_recv.info;
+	trace_tls_device_offload_set(sk, TLS_OFFLOAD_CTX_DIR_RX,
+				     tcp_sk(sk)->copied_seq, info->rec_seq, rc);
+	if (rc)
+		goto free_sw_resources;
+
+	tls_device_attach(ctx, sk, netdev);
+	up_read(&device_offload_lock);
+
+	dev_put(netdev);
+
+	return 0;
+
+free_sw_resources:
+	up_read(&device_offload_lock);
+	tls_sw_free_resources_rx(sk);
+	down_read(&device_offload_lock);
+release_ctx:
+	ctx->priv_ctx_rx = NULL;
+release_lock:
+	up_read(&device_offload_lock);
+release_netdev:
+	dev_put(netdev);
+	return rc;
+}
+
+void tls_device_offload_cleanup_rx(struct sock *sk)
+{
+	struct tls_context *tls_ctx = tls_get_ctx(sk);
+	struct net_device *netdev;
+
+	down_read(&device_offload_lock);
+	netdev = rcu_dereference_protected(tls_ctx->netdev,
+					   lockdep_is_held(&device_offload_lock));
+	if (!netdev)
+		goto out;
+
+	netdev->tlsdev_ops->tls_dev_del(netdev, tls_ctx,
+					TLS_OFFLOAD_CTX_DIR_RX);
+
+	if (tls_ctx->tx_conf != TLS_HW) {
+		dev_put(netdev);
+		rcu_assign_pointer(tls_ctx->netdev, NULL);
+	} else {
+		set_bit(TLS_RX_DEV_CLOSED, &tls_ctx->flags);
+	}
+out:
+	up_read(&device_offload_lock);
+	tls_sw_release_resources_rx(sk);
+}
+
+static int tls_device_down(struct net_device *netdev)
+{
+	struct tls_context *ctx, *tmp;
+	unsigned long flags;
+	LIST_HEAD(list);
+
+	/* Request a write lock to block new offload attempts */
+	down_write(&device_offload_lock);
+
+	spin_lock_irqsave(&tls_device_lock, flags);
+	list_for_each_entry_safe(ctx, tmp, &tls_device_list, list) {
+		struct net_device *ctx_netdev =
+			rcu_dereference_protected(ctx->netdev,
+						  lockdep_is_held(&device_offload_lock));
+
+		if (ctx_netdev != netdev ||
+		    !refcount_inc_not_zero(&ctx->refcount))
+			continue;
+
+		list_move(&ctx->list, &list);
+	}
+	spin_unlock_irqrestore(&tls_device_lock, flags);
+
+	list_for_each_entry_safe(ctx, tmp, &list, list)	{
+		/* Stop offloaded TX and switch to the fallback.
+		 * tls_is_sk_tx_device_offloaded will return false.
+		 */
+		WRITE_ONCE(ctx->sk->sk_validate_xmit_skb, tls_validate_xmit_skb_sw);
+
+		/* Stop the RX and TX resync.
+		 * tls_dev_resync must not be called after tls_dev_del.
+		 */
+		rcu_assign_pointer(ctx->netdev, NULL);
+
+		/* Start skipping the RX resync logic completely. */
+		set_bit(TLS_RX_DEV_DEGRADED, &ctx->flags);
+
+		/* Sync with inflight packets. After this point:
+		 * TX: no non-encrypted packets will be passed to the driver.
+		 * RX: resync requests from the driver will be ignored.
+		 */
+		synchronize_net();
+
+		/* Release the offload context on the driver side. */
+		if (ctx->tx_conf == TLS_HW)
+			netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
+							TLS_OFFLOAD_CTX_DIR_TX);
+		if (ctx->rx_conf == TLS_HW &&
+		    !test_bit(TLS_RX_DEV_CLOSED, &ctx->flags))
+			netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
+							TLS_OFFLOAD_CTX_DIR_RX);
+
+		dev_put(netdev);
+
+		/* Move the context to a separate list for two reasons:
+		 * 1. When the context is deallocated, list_del is called.
+		 * 2. It's no longer an offloaded context, so we don't want to
+		 *    run offload-specific code on this context.
+		 */
+		spin_lock_irqsave(&tls_device_lock, flags);
+		list_move_tail(&ctx->list, &tls_device_down_list);
+		spin_unlock_irqrestore(&tls_device_lock, flags);
+
+		/* Device contexts for RX and TX will be freed in on sk_destruct
+		 * by tls_device_free_ctx. rx_conf and tx_conf stay in TLS_HW.
+		 * Now release the ref taken above.
+		 */
+		if (refcount_dec_and_test(&ctx->refcount)) {
+			/* sk_destruct ran after tls_device_down took a ref, and
+			 * it returned early. Complete the destruction here.
+			 */
+			list_del(&ctx->list);
+			tls_device_free_ctx(ctx);
+		}
+	}
+
+	up_write(&device_offload_lock);
+
+	flush_workqueue(destruct_wq);
+
+	return NOTIFY_DONE;
+}
+
+static int tls_dev_event(struct notifier_block *this, unsigned long event,
+			 void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+
+	if (!dev->tlsdev_ops &&
+	    !(dev->features & (NETIF_F_HW_TLS_RX | NETIF_F_HW_TLS_TX)))
+		return NOTIFY_DONE;
+
+	switch (event) {
+	case NETDEV_REGISTER:
+	case NETDEV_FEAT_CHANGE:
+		if (netif_is_bond_master(dev))
+			return NOTIFY_DONE;
+		if ((dev->features & NETIF_F_HW_TLS_RX) &&
+		    !dev->tlsdev_ops->tls_dev_resync)
+			return NOTIFY_BAD;
+
+		if  (dev->tlsdev_ops &&
+		     dev->tlsdev_ops->tls_dev_add &&
+		     dev->tlsdev_ops->tls_dev_del)
+			return NOTIFY_DONE;
+		else
+			return NOTIFY_BAD;
+	case NETDEV_DOWN:
+		return tls_device_down(dev);
+	}
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block tls_dev_notifier = {
+	.notifier_call	= tls_dev_event,
+};
+
+int __init tls_device_init(void)
+{
+	int err;
+
+	dummy_page = alloc_page(GFP_KERNEL);
+	if (!dummy_page)
+		return -ENOMEM;
+
+	destruct_wq = alloc_workqueue("ktls_device_destruct", 0, 0);
+	if (!destruct_wq) {
+		err = -ENOMEM;
+		goto err_free_dummy;
+	}
+
+	err = register_netdevice_notifier(&tls_dev_notifier);
+	if (err)
+		goto err_destroy_wq;
+
+	return 0;
+
+err_destroy_wq:
+	destroy_workqueue(destruct_wq);
+err_free_dummy:
+	put_page(dummy_page);
+	return err;
+}
+
+void __exit tls_device_cleanup(void)
+{
+	unregister_netdevice_notifier(&tls_dev_notifier);
+	destroy_workqueue(destruct_wq);
+	clean_acked_data_flush();
+	put_page(dummy_page);
+}