1 files changed, 764 insertions, 0 deletions

diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
new file mode 100644
index 000000000000..ac45d6224e41
--- /dev/null
+++ b/net/tls/tls_device.c
@@ -0,0 +1,764 @@
+/* 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>
+
+/* device_offload_lock is used to synchronize tls_dev_add
+ * against NETDEV_DOWN notifications.
+ */
+static DECLARE_RWSEM(device_offload_lock);
+
+static void tls_device_gc_task(struct work_struct *work);
+
+static DECLARE_WORK(tls_device_gc_work, tls_device_gc_task);
+static LIST_HEAD(tls_device_gc_list);
+static LIST_HEAD(tls_device_list);
+static DEFINE_SPINLOCK(tls_device_lock);
+
+static void tls_device_free_ctx(struct tls_context *ctx)
+{
+        struct tls_offload_context *offload_ctx = tls_offload_ctx(ctx);
+
+        kfree(offload_ctx);
+        kfree(ctx);
+}
+
+static void tls_device_gc_task(struct work_struct *work)
+{
+        struct tls_context *ctx, *tmp;
+        unsigned long flags;
+        LIST_HEAD(gc_list);
+
+        spin_lock_irqsave(&tls_device_lock, flags);
+        list_splice_init(&tls_device_gc_list, &gc_list);
+        spin_unlock_irqrestore(&tls_device_lock, flags);
+
+        list_for_each_entry_safe(ctx, tmp, &gc_list, list) {
+                struct net_device *netdev = ctx->netdev;
+
+                if (netdev) {
+                        netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
+                                                        TLS_OFFLOAD_CTX_DIR_TX);
+                        dev_put(netdev);
+                }
+
+                list_del(&ctx->list);
+                tls_device_free_ctx(ctx);
+        }
+}
+
+static void tls_device_queue_ctx_destruction(struct tls_context *ctx)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&tls_device_lock, flags);
+        list_move_tail(&ctx->list, &tls_device_gc_list);
+
+        /* schedule_work inside the spinlock
+         * to make sure tls_device_down waits for that work.
+         */
+        schedule_work(&tls_device_gc_work);
+
+        spin_unlock_irqrestore(&tls_device_lock, flags);
+}
+
+/* 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 = dst->dev;
+                dev_hold(netdev);
+        }
+
+        dst_release(dst);
+
+        return netdev;
+}
+
+static void destroy_record(struct tls_record_info *record)
+{
+        int nr_frags = record->num_frags;
+        skb_frag_t *frag;
+
+        while (nr_frags-- > 0) {
+                frag = &record->frags[nr_frags];
+                __skb_frag_unref(frag);
+        }
+        kfree(record);
+}
+
+static void delete_all_records(struct tls_offload_context *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 *ctx;
+        u64 deleted_records = 0;
+        unsigned long flags;
+
+        if (!tls_ctx)
+                return;
+
+        ctx = tls_offload_ctx(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_del(&info->list);
+                destroy_record(info);
+                deleted_records++;
+        }
+
+        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 *ctx = tls_offload_ctx(tls_ctx);
+
+        if (ctx->open_record)
+                destroy_record(ctx->open_record);
+
+        delete_all_records(ctx);
+        crypto_free_aead(ctx->aead_send);
+        ctx->sk_destruct(sk);
+        clean_acked_data_disable(inet_csk(sk));
+
+        if (refcount_dec_and_test(&tls_ctx->refcount))
+                tls_device_queue_ctx_destruction(tls_ctx);
+}
+EXPORT_SYMBOL(tls_device_sk_destruct);
+
+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 (frag->page.p == pfrag->page &&
+            frag->page_offset + frag->size == pfrag->offset) {
+                frag->size += size;
+        } else {
+                ++frag;
+                frag->page.p = pfrag->page;
+                frag->page_offset = pfrag->offset;
+                frag->size = 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 *offload_ctx,
+                           struct tls_record_info *record,
+                           struct page_frag *pfrag,
+                           int flags,
+                           unsigned char record_type)
+{
+        struct tcp_sock *tp = tcp_sk(sk);
+        struct page_frag dummy_tag_frag;
+        skb_frag_t *frag;
+        int i;
+
+        /* fill prepend */
+        frag = &record->frags[0];
+        tls_fill_prepend(ctx,
+                         skb_frag_address(frag),
+                         record->len - ctx->tx.prepend_size,
+                         record_type);
+
+        /* HW doesn't care about the data in the tag, because it fills it. */
+        dummy_tag_frag.page = skb_frag_page(frag);
+        dummy_tag_frag.offset = 0;
+
+        tls_append_frag(record, &dummy_tag_frag, ctx->tx.tag_size);
+        record->end_seq = tp->write_seq + record->len;
+        spin_lock_irq(&offload_ctx->lock);
+        list_add_tail(&record->list, &offload_ctx->records_list);
+        spin_unlock_irq(&offload_ctx->lock);
+        offload_ctx->open_record = NULL;
+        set_bit(TLS_PENDING_CLOSED_RECORD, &ctx->flags);
+        tls_advance_record_sn(sk, &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),
+                            frag->size, frag->page_offset);
+                sk_mem_charge(sk, frag->size);
+                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 int tls_create_new_record(struct tls_offload_context *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);
+        frag->page_offset = 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 *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))) {
+                        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_push_data(struct sock *sk,
+                         struct iov_iter *msg_iter,
+                         size_t size, int flags,
+                         unsigned char record_type)
+{
+        struct tls_context *tls_ctx = tls_get_ctx(sk);
+        struct tls_offload_context *ctx = tls_offload_ctx(tls_ctx);
+        int tls_push_record_flags = flags | MSG_SENDPAGE_NOTLAST;
+        int more = flags & (MSG_SENDPAGE_NOTLAST | MSG_MORE);
+        struct tls_record_info *record = ctx->open_record;
+        struct page_frag *pfrag;
+        size_t orig_size = size;
+        u32 max_open_record_len;
+        int copy, rc = 0;
+        bool done = false;
+        long timeo;
+
+        if (flags &
+            ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL | MSG_SENDPAGE_NOTLAST))
+                return -ENOTSUPP;
+
+        if (sk->sk_err)
+                return -sk->sk_err;
+
+        timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
+        rc = tls_complete_pending_work(sk, tls_ctx, flags, &timeo);
+        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 +
+                              tls_ctx->tx.prepend_size;
+        do {
+                rc = tls_do_allocation(sk, ctx, pfrag,
+                                       tls_ctx->tx.prepend_size);
+                if (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 > tls_ctx->tx.prepend_size) {
+                                goto last_record;
+                        }
+
+                        break;
+                }
+
+                record = ctx->open_record;
+                copy = min_t(size_t, size, (pfrag->size - pfrag->offset));
+                copy = min_t(size_t, copy, (max_open_record_len - record->len));
+
+                if (copy_from_iter_nocache(page_address(pfrag->page) +
+                                               pfrag->offset,
+                                           copy, msg_iter) != copy) {
+                        rc = -EFAULT;
+                        goto handle_error;
+                }
+                tls_append_frag(record, pfrag, copy);
+
+                size -= copy;
+                if (!size) {
+last_record:
+                        tls_push_record_flags = flags;
+                        if (more) {
+                                tls_ctx->pending_open_record_frags =
+                                                record->num_frags;
+                                break;
+                        }
+
+                        done = true;
+                }
+
+                if (done || record->len >= max_open_record_len ||
+                    (record->num_frags >= MAX_SKB_FRAGS - 1)) {
+                        rc = tls_push_record(sk,
+                                             tls_ctx,
+                                             ctx,
+                                             record,
+                                             pfrag,
+                                             tls_push_record_flags,
+                                             record_type);
+                        if (rc < 0)
+                                break;
+                }
+        } while (!done);
+
+        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;
+        int rc;
+
+        lock_sock(sk);
+
+        if (unlikely(msg->msg_controllen)) {
+                rc = tls_proccess_cmsg(sk, msg, &record_type);
+                if (rc)
+                        goto out;
+        }
+
+        rc = tls_push_data(sk, &msg->msg_iter, size,
+                           msg->msg_flags, record_type);
+
+out:
+        release_sock(sk);
+        return rc;
+}
+
+int tls_device_sendpage(struct sock *sk, struct page *page,
+                        int offset, size_t size, int flags)
+{
+        struct iov_iter msg_iter;
+        char *kaddr = kmap(page);
+        struct kvec iov;
+        int rc;
+
+        if (flags & MSG_SENDPAGE_NOTLAST)
+                flags |= MSG_MORE;
+
+        lock_sock(sk);
+
+        if (flags & MSG_OOB) {
+                rc = -ENOTSUPP;
+                goto out;
+        }
+
+        iov.iov_base = kaddr + offset;
+        iov.iov_len = size;
+        iov_iter_kvec(&msg_iter, WRITE | ITER_KVEC, &iov, 1, size);
+        rc = tls_push_data(sk, &msg_iter, size,
+                           flags, TLS_RECORD_TYPE_DATA);
+        kunmap(page);
+
+out:
+        release_sock(sk);
+        return rc;
+}
+
+struct tls_record_info *tls_get_record(struct tls_offload_context *context,
+                                       u32 seq, u64 *p_record_sn)
+{
+        u64 record_sn = context->hint_record_sn;
+        struct tls_record_info *info;
+
+        info = context->retransmit_hint;
+        if (!info ||
+            before(seq, info->end_seq - info->len)) {
+                /* if retransmit_hint is irrelevant start
+                 * from the beggining of the list
+                 */
+                info = list_first_entry(&context->records_list,
+                                        struct tls_record_info, list);
+                record_sn = context->unacked_record_sn;
+        }
+
+        list_for_each_entry_from(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;
+                        return info;
+                }
+                record_sn++;
+        }
+
+        return NULL;
+}
+EXPORT_SYMBOL(tls_get_record);
+
+static int tls_device_push_pending_record(struct sock *sk, int flags)
+{
+        struct iov_iter msg_iter;
+
+        iov_iter_kvec(&msg_iter, WRITE | ITER_KVEC, NULL, 0, 0);
+        return tls_push_data(sk, &msg_iter, 0, flags, TLS_RECORD_TYPE_DATA);
+}
+
+int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
+{
+        u16 nonce_size, tag_size, iv_size, rec_seq_size;
+        struct tls_record_info *start_marker_record;
+        struct tls_offload_context *offload_ctx;
+        struct tls_crypto_info *crypto_info;
+        struct net_device *netdev;
+        char *iv, *rec_seq;
+        struct sk_buff *skb;
+        int rc = -EINVAL;
+        __be64 rcd_sn;
+
+        if (!ctx)
+                goto out;
+
+        if (ctx->priv_ctx_tx) {
+                rc = -EEXIST;
+                goto out;
+        }
+
+        start_marker_record = kmalloc(sizeof(*start_marker_record), GFP_KERNEL);
+        if (!start_marker_record) {
+                rc = -ENOMEM;
+                goto out;
+        }
+
+        offload_ctx = kzalloc(TLS_OFFLOAD_CONTEXT_SIZE, GFP_KERNEL);
+        if (!offload_ctx) {
+                rc = -ENOMEM;
+                goto free_marker_record;
+        }
+
+        crypto_info = &ctx->crypto_send;
+        switch (crypto_info->cipher_type) {
+        case TLS_CIPHER_AES_GCM_128:
+                nonce_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
+                tag_size = TLS_CIPHER_AES_GCM_128_TAG_SIZE;
+                iv_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
+                iv = ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->iv;
+                rec_seq_size = TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE;
+                rec_seq =
+                 ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->rec_seq;
+                break;
+        default:
+                rc = -EINVAL;
+                goto free_offload_ctx;
+        }
+
+        ctx->tx.prepend_size = TLS_HEADER_SIZE + nonce_size;
+        ctx->tx.tag_size = tag_size;
+        ctx->tx.overhead_size = ctx->tx.prepend_size + ctx->tx.tag_size;
+        ctx->tx.iv_size = iv_size;
+        ctx->tx.iv = kmalloc(iv_size + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
+                             GFP_KERNEL);
+        if (!ctx->tx.iv) {
+                rc = -ENOMEM;
+                goto free_offload_ctx;
+        }
+
+        memcpy(ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv, iv_size);
+
+        ctx->tx.rec_seq_size = rec_seq_size;
+        ctx->tx.rec_seq = kmalloc(rec_seq_size, GFP_KERNEL);
+        if (!ctx->tx.rec_seq) {
+                rc = -ENOMEM;
+                goto free_iv;
+        }
+        memcpy(ctx->tx.rec_seq, rec_seq, rec_seq_size);
+
+        rc = tls_sw_fallback_init(sk, offload_ctx, crypto_info);
+        if (rc)
+                goto free_rec_seq;
+
+        /* 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_LIST_HEAD(&offload_ctx->records_list);
+        list_add_tail(&start_marker_record->list, &offload_ctx->records_list);
+        spin_lock_init(&offload_ctx->lock);
+
+        clean_acked_data_enable(inet_csk(sk), &tls_icsk_clean_acked);
+        ctx->push_pending_record = tls_device_push_pending_record;
+        offload_ctx->sk_destruct = sk->sk_destruct;
+
+        /* 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;
+
+        refcount_set(&ctx->refcount, 1);
+
+        /* We support starting offload on multiple sockets
+         * concurrently, so we only need a read lock here.
+         * This lock must precede get_netdev_for_sock to prevent races between
+         * NETDEV_DOWN and setsockopt.
+         */
+        down_read(&device_offload_lock);
+        netdev = get_netdev_for_sock(sk);
+        if (!netdev) {
+                pr_err_ratelimited("%s: netdev not found\n", __func__);
+                rc = -EINVAL;
+                goto release_lock;
+        }
+
+        if (!(netdev->features & NETIF_F_HW_TLS_TX)) {
+                rc = -ENOTSUPP;
+                goto release_netdev;
+        }
+
+        /* Avoid offloading if the device is down
+         * We don't want to offload new flows after
+         * the NETDEV_DOWN event
+         */
+        if (!(netdev->flags & IFF_UP)) {
+                rc = -EINVAL;
+                goto release_netdev;
+        }
+
+        ctx->priv_ctx_tx = offload_ctx;
+        rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_TX,
+                                             &ctx->crypto_send,
+                                             tcp_sk(sk)->write_seq);
+        if (rc)
+                goto release_netdev;
+
+        ctx->netdev = netdev;
+
+        spin_lock_irq(&tls_device_lock);
+        list_add_tail(&ctx->list, &tls_device_list);
+        spin_unlock_irq(&tls_device_lock);
+
+        sk->sk_validate_xmit_skb = tls_validate_xmit_skb;
+        /* 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_destruct,
+                          &tls_device_sk_destruct);
+        up_read(&device_offload_lock);
+        goto out;
+
+release_netdev:
+        dev_put(netdev);
+release_lock:
+        up_read(&device_offload_lock);
+        clean_acked_data_disable(inet_csk(sk));
+        crypto_free_aead(offload_ctx->aead_send);
+free_rec_seq:
+        kfree(ctx->tx.rec_seq);
+free_iv:
+        kfree(ctx->tx.iv);
+free_offload_ctx:
+        kfree(offload_ctx);
+        ctx->priv_ctx_tx = NULL;
+free_marker_record:
+        kfree(start_marker_record);
+out:
+        return rc;
+}
+
+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) {
+                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) {
+                netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
+                                                TLS_OFFLOAD_CTX_DIR_TX);
+                ctx->netdev = NULL;
+                dev_put(netdev);
+                list_del_init(&ctx->list);
+
+                if (refcount_dec_and_test(&ctx->refcount))
+                        tls_device_free_ctx(ctx);
+        }
+
+        up_write(&device_offload_lock);
+
+        flush_work(&tls_device_gc_work);
+
+        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->features & NETIF_F_HW_TLS_TX))
+                return NOTIFY_DONE;
+
+        switch (event) {
+        case NETDEV_REGISTER:
+        case NETDEV_FEAT_CHANGE:
+                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,
+};
+
+void __init tls_device_init(void)
+{
+        register_netdevice_notifier(&tls_dev_notifier);
+}
+
+void __exit tls_device_cleanup(void)
+{
+        unregister_netdevice_notifier(&tls_dev_notifier);
+        flush_work(&tls_device_gc_work);
+}