xref: /linux/net/tls/tls_device.c (revision 7895d662bab8827176d44326d0a7423221287ca9)
1 /* Copyright (c) 2018, Mellanox Technologies All rights reserved.
2  *
3  * This software is available to you under a choice of one of two
4  * licenses.  You may choose to be licensed under the terms of the GNU
5  * General Public License (GPL) Version 2, available from the file
6  * COPYING in the main directory of this source tree, or the
7  * OpenIB.org BSD license below:
8  *
9  *     Redistribution and use in source and binary forms, with or
10  *     without modification, are permitted provided that the following
11  *     conditions are met:
12  *
13  *      - Redistributions of source code must retain the above
14  *        copyright notice, this list of conditions and the following
15  *        disclaimer.
16  *
17  *      - Redistributions in binary form must reproduce the above
18  *        copyright notice, this list of conditions and the following
19  *        disclaimer in the documentation and/or other materials
20  *        provided with the distribution.
21  *
22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
23  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
24  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
25  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
26  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
27  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
28  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
29  * SOFTWARE.
30  */
31 
32 #include <crypto/aead.h>
33 #include <linux/highmem.h>
34 #include <linux/module.h>
35 #include <linux/netdevice.h>
36 #include <net/dst.h>
37 #include <net/inet_connection_sock.h>
38 #include <net/tcp.h>
39 #include <net/tls.h>
40 
41 #include "trace.h"
42 
43 /* device_offload_lock is used to synchronize tls_dev_add
44  * against NETDEV_DOWN notifications.
45  */
46 static DECLARE_RWSEM(device_offload_lock);
47 
48 static void tls_device_gc_task(struct work_struct *work);
49 
50 static DECLARE_WORK(tls_device_gc_work, tls_device_gc_task);
51 static LIST_HEAD(tls_device_gc_list);
52 static LIST_HEAD(tls_device_list);
53 static DEFINE_SPINLOCK(tls_device_lock);
54 
55 static void tls_device_free_ctx(struct tls_context *ctx)
56 {
57 	if (ctx->tx_conf == TLS_HW) {
58 		kfree(tls_offload_ctx_tx(ctx));
59 		kfree(ctx->tx.rec_seq);
60 		kfree(ctx->tx.iv);
61 	}
62 
63 	if (ctx->rx_conf == TLS_HW)
64 		kfree(tls_offload_ctx_rx(ctx));
65 
66 	tls_ctx_free(NULL, ctx);
67 }
68 
69 static void tls_device_gc_task(struct work_struct *work)
70 {
71 	struct tls_context *ctx, *tmp;
72 	unsigned long flags;
73 	LIST_HEAD(gc_list);
74 
75 	spin_lock_irqsave(&tls_device_lock, flags);
76 	list_splice_init(&tls_device_gc_list, &gc_list);
77 	spin_unlock_irqrestore(&tls_device_lock, flags);
78 
79 	list_for_each_entry_safe(ctx, tmp, &gc_list, list) {
80 		struct net_device *netdev = ctx->netdev;
81 
82 		if (netdev && ctx->tx_conf == TLS_HW) {
83 			netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
84 							TLS_OFFLOAD_CTX_DIR_TX);
85 			dev_put(netdev);
86 			ctx->netdev = NULL;
87 		}
88 
89 		list_del(&ctx->list);
90 		tls_device_free_ctx(ctx);
91 	}
92 }
93 
94 static void tls_device_queue_ctx_destruction(struct tls_context *ctx)
95 {
96 	unsigned long flags;
97 
98 	spin_lock_irqsave(&tls_device_lock, flags);
99 	list_move_tail(&ctx->list, &tls_device_gc_list);
100 
101 	/* schedule_work inside the spinlock
102 	 * to make sure tls_device_down waits for that work.
103 	 */
104 	schedule_work(&tls_device_gc_work);
105 
106 	spin_unlock_irqrestore(&tls_device_lock, flags);
107 }
108 
109 /* We assume that the socket is already connected */
110 static struct net_device *get_netdev_for_sock(struct sock *sk)
111 {
112 	struct dst_entry *dst = sk_dst_get(sk);
113 	struct net_device *netdev = NULL;
114 
115 	if (likely(dst)) {
116 		netdev = dst->dev;
117 		dev_hold(netdev);
118 	}
119 
120 	dst_release(dst);
121 
122 	return netdev;
123 }
124 
125 static void destroy_record(struct tls_record_info *record)
126 {
127 	int i;
128 
129 	for (i = 0; i < record->num_frags; i++)
130 		__skb_frag_unref(&record->frags[i]);
131 	kfree(record);
132 }
133 
134 static void delete_all_records(struct tls_offload_context_tx *offload_ctx)
135 {
136 	struct tls_record_info *info, *temp;
137 
138 	list_for_each_entry_safe(info, temp, &offload_ctx->records_list, list) {
139 		list_del(&info->list);
140 		destroy_record(info);
141 	}
142 
143 	offload_ctx->retransmit_hint = NULL;
144 }
145 
146 static void tls_icsk_clean_acked(struct sock *sk, u32 acked_seq)
147 {
148 	struct tls_context *tls_ctx = tls_get_ctx(sk);
149 	struct tls_record_info *info, *temp;
150 	struct tls_offload_context_tx *ctx;
151 	u64 deleted_records = 0;
152 	unsigned long flags;
153 
154 	if (!tls_ctx)
155 		return;
156 
157 	ctx = tls_offload_ctx_tx(tls_ctx);
158 
159 	spin_lock_irqsave(&ctx->lock, flags);
160 	info = ctx->retransmit_hint;
161 	if (info && !before(acked_seq, info->end_seq))
162 		ctx->retransmit_hint = NULL;
163 
164 	list_for_each_entry_safe(info, temp, &ctx->records_list, list) {
165 		if (before(acked_seq, info->end_seq))
166 			break;
167 		list_del(&info->list);
168 
169 		destroy_record(info);
170 		deleted_records++;
171 	}
172 
173 	ctx->unacked_record_sn += deleted_records;
174 	spin_unlock_irqrestore(&ctx->lock, flags);
175 }
176 
177 /* At this point, there should be no references on this
178  * socket and no in-flight SKBs associated with this
179  * socket, so it is safe to free all the resources.
180  */
181 void tls_device_sk_destruct(struct sock *sk)
182 {
183 	struct tls_context *tls_ctx = tls_get_ctx(sk);
184 	struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
185 
186 	tls_ctx->sk_destruct(sk);
187 
188 	if (tls_ctx->tx_conf == TLS_HW) {
189 		if (ctx->open_record)
190 			destroy_record(ctx->open_record);
191 		delete_all_records(ctx);
192 		crypto_free_aead(ctx->aead_send);
193 		clean_acked_data_disable(inet_csk(sk));
194 	}
195 
196 	if (refcount_dec_and_test(&tls_ctx->refcount))
197 		tls_device_queue_ctx_destruction(tls_ctx);
198 }
199 EXPORT_SYMBOL_GPL(tls_device_sk_destruct);
200 
201 void tls_device_free_resources_tx(struct sock *sk)
202 {
203 	struct tls_context *tls_ctx = tls_get_ctx(sk);
204 
205 	tls_free_partial_record(sk, tls_ctx);
206 }
207 
208 void tls_offload_tx_resync_request(struct sock *sk, u32 got_seq, u32 exp_seq)
209 {
210 	struct tls_context *tls_ctx = tls_get_ctx(sk);
211 
212 	trace_tls_device_tx_resync_req(sk, got_seq, exp_seq);
213 	WARN_ON(test_and_set_bit(TLS_TX_SYNC_SCHED, &tls_ctx->flags));
214 }
215 EXPORT_SYMBOL_GPL(tls_offload_tx_resync_request);
216 
217 static void tls_device_resync_tx(struct sock *sk, struct tls_context *tls_ctx,
218 				 u32 seq)
219 {
220 	struct net_device *netdev;
221 	struct sk_buff *skb;
222 	int err = 0;
223 	u8 *rcd_sn;
224 
225 	skb = tcp_write_queue_tail(sk);
226 	if (skb)
227 		TCP_SKB_CB(skb)->eor = 1;
228 
229 	rcd_sn = tls_ctx->tx.rec_seq;
230 
231 	trace_tls_device_tx_resync_send(sk, seq, rcd_sn);
232 	down_read(&device_offload_lock);
233 	netdev = tls_ctx->netdev;
234 	if (netdev)
235 		err = netdev->tlsdev_ops->tls_dev_resync(netdev, sk, seq,
236 							 rcd_sn,
237 							 TLS_OFFLOAD_CTX_DIR_TX);
238 	up_read(&device_offload_lock);
239 	if (err)
240 		return;
241 
242 	clear_bit_unlock(TLS_TX_SYNC_SCHED, &tls_ctx->flags);
243 }
244 
245 static void tls_append_frag(struct tls_record_info *record,
246 			    struct page_frag *pfrag,
247 			    int size)
248 {
249 	skb_frag_t *frag;
250 
251 	frag = &record->frags[record->num_frags - 1];
252 	if (skb_frag_page(frag) == pfrag->page &&
253 	    skb_frag_off(frag) + skb_frag_size(frag) == pfrag->offset) {
254 		skb_frag_size_add(frag, size);
255 	} else {
256 		++frag;
257 		__skb_frag_set_page(frag, pfrag->page);
258 		skb_frag_off_set(frag, pfrag->offset);
259 		skb_frag_size_set(frag, size);
260 		++record->num_frags;
261 		get_page(pfrag->page);
262 	}
263 
264 	pfrag->offset += size;
265 	record->len += size;
266 }
267 
268 static int tls_push_record(struct sock *sk,
269 			   struct tls_context *ctx,
270 			   struct tls_offload_context_tx *offload_ctx,
271 			   struct tls_record_info *record,
272 			   int flags)
273 {
274 	struct tls_prot_info *prot = &ctx->prot_info;
275 	struct tcp_sock *tp = tcp_sk(sk);
276 	skb_frag_t *frag;
277 	int i;
278 
279 	record->end_seq = tp->write_seq + record->len;
280 	list_add_tail_rcu(&record->list, &offload_ctx->records_list);
281 	offload_ctx->open_record = NULL;
282 
283 	if (test_bit(TLS_TX_SYNC_SCHED, &ctx->flags))
284 		tls_device_resync_tx(sk, ctx, tp->write_seq);
285 
286 	tls_advance_record_sn(sk, prot, &ctx->tx);
287 
288 	for (i = 0; i < record->num_frags; i++) {
289 		frag = &record->frags[i];
290 		sg_unmark_end(&offload_ctx->sg_tx_data[i]);
291 		sg_set_page(&offload_ctx->sg_tx_data[i], skb_frag_page(frag),
292 			    skb_frag_size(frag), skb_frag_off(frag));
293 		sk_mem_charge(sk, skb_frag_size(frag));
294 		get_page(skb_frag_page(frag));
295 	}
296 	sg_mark_end(&offload_ctx->sg_tx_data[record->num_frags - 1]);
297 
298 	/* all ready, send */
299 	return tls_push_sg(sk, ctx, offload_ctx->sg_tx_data, 0, flags);
300 }
301 
302 static int tls_device_record_close(struct sock *sk,
303 				   struct tls_context *ctx,
304 				   struct tls_record_info *record,
305 				   struct page_frag *pfrag,
306 				   unsigned char record_type)
307 {
308 	struct tls_prot_info *prot = &ctx->prot_info;
309 	int ret;
310 
311 	/* append tag
312 	 * device will fill in the tag, we just need to append a placeholder
313 	 * use socket memory to improve coalescing (re-using a single buffer
314 	 * increases frag count)
315 	 * if we can't allocate memory now, steal some back from data
316 	 */
317 	if (likely(skb_page_frag_refill(prot->tag_size, pfrag,
318 					sk->sk_allocation))) {
319 		ret = 0;
320 		tls_append_frag(record, pfrag, prot->tag_size);
321 	} else {
322 		ret = prot->tag_size;
323 		if (record->len <= prot->overhead_size)
324 			return -ENOMEM;
325 	}
326 
327 	/* fill prepend */
328 	tls_fill_prepend(ctx, skb_frag_address(&record->frags[0]),
329 			 record->len - prot->overhead_size,
330 			 record_type, prot->version);
331 	return ret;
332 }
333 
334 static int tls_create_new_record(struct tls_offload_context_tx *offload_ctx,
335 				 struct page_frag *pfrag,
336 				 size_t prepend_size)
337 {
338 	struct tls_record_info *record;
339 	skb_frag_t *frag;
340 
341 	record = kmalloc(sizeof(*record), GFP_KERNEL);
342 	if (!record)
343 		return -ENOMEM;
344 
345 	frag = &record->frags[0];
346 	__skb_frag_set_page(frag, pfrag->page);
347 	skb_frag_off_set(frag, pfrag->offset);
348 	skb_frag_size_set(frag, prepend_size);
349 
350 	get_page(pfrag->page);
351 	pfrag->offset += prepend_size;
352 
353 	record->num_frags = 1;
354 	record->len = prepend_size;
355 	offload_ctx->open_record = record;
356 	return 0;
357 }
358 
359 static int tls_do_allocation(struct sock *sk,
360 			     struct tls_offload_context_tx *offload_ctx,
361 			     struct page_frag *pfrag,
362 			     size_t prepend_size)
363 {
364 	int ret;
365 
366 	if (!offload_ctx->open_record) {
367 		if (unlikely(!skb_page_frag_refill(prepend_size, pfrag,
368 						   sk->sk_allocation))) {
369 			READ_ONCE(sk->sk_prot)->enter_memory_pressure(sk);
370 			sk_stream_moderate_sndbuf(sk);
371 			return -ENOMEM;
372 		}
373 
374 		ret = tls_create_new_record(offload_ctx, pfrag, prepend_size);
375 		if (ret)
376 			return ret;
377 
378 		if (pfrag->size > pfrag->offset)
379 			return 0;
380 	}
381 
382 	if (!sk_page_frag_refill(sk, pfrag))
383 		return -ENOMEM;
384 
385 	return 0;
386 }
387 
388 static int tls_device_copy_data(void *addr, size_t bytes, struct iov_iter *i)
389 {
390 	size_t pre_copy, nocache;
391 
392 	pre_copy = ~((unsigned long)addr - 1) & (SMP_CACHE_BYTES - 1);
393 	if (pre_copy) {
394 		pre_copy = min(pre_copy, bytes);
395 		if (copy_from_iter(addr, pre_copy, i) != pre_copy)
396 			return -EFAULT;
397 		bytes -= pre_copy;
398 		addr += pre_copy;
399 	}
400 
401 	nocache = round_down(bytes, SMP_CACHE_BYTES);
402 	if (copy_from_iter_nocache(addr, nocache, i) != nocache)
403 		return -EFAULT;
404 	bytes -= nocache;
405 	addr += nocache;
406 
407 	if (bytes && copy_from_iter(addr, bytes, i) != bytes)
408 		return -EFAULT;
409 
410 	return 0;
411 }
412 
413 static int tls_push_data(struct sock *sk,
414 			 struct iov_iter *msg_iter,
415 			 size_t size, int flags,
416 			 unsigned char record_type)
417 {
418 	struct tls_context *tls_ctx = tls_get_ctx(sk);
419 	struct tls_prot_info *prot = &tls_ctx->prot_info;
420 	struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
421 	int more = flags & (MSG_SENDPAGE_NOTLAST | MSG_MORE);
422 	struct tls_record_info *record = ctx->open_record;
423 	int tls_push_record_flags;
424 	struct page_frag *pfrag;
425 	size_t orig_size = size;
426 	u32 max_open_record_len;
427 	int copy, rc = 0;
428 	bool done = false;
429 	long timeo;
430 
431 	if (flags &
432 	    ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL | MSG_SENDPAGE_NOTLAST))
433 		return -EOPNOTSUPP;
434 
435 	if (unlikely(sk->sk_err))
436 		return -sk->sk_err;
437 
438 	flags |= MSG_SENDPAGE_DECRYPTED;
439 	tls_push_record_flags = flags | MSG_SENDPAGE_NOTLAST;
440 
441 	timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
442 	if (tls_is_partially_sent_record(tls_ctx)) {
443 		rc = tls_push_partial_record(sk, tls_ctx, flags);
444 		if (rc < 0)
445 			return rc;
446 	}
447 
448 	pfrag = sk_page_frag(sk);
449 
450 	/* TLS_HEADER_SIZE is not counted as part of the TLS record, and
451 	 * we need to leave room for an authentication tag.
452 	 */
453 	max_open_record_len = TLS_MAX_PAYLOAD_SIZE +
454 			      prot->prepend_size;
455 	do {
456 		rc = tls_do_allocation(sk, ctx, pfrag, prot->prepend_size);
457 		if (unlikely(rc)) {
458 			rc = sk_stream_wait_memory(sk, &timeo);
459 			if (!rc)
460 				continue;
461 
462 			record = ctx->open_record;
463 			if (!record)
464 				break;
465 handle_error:
466 			if (record_type != TLS_RECORD_TYPE_DATA) {
467 				/* avoid sending partial
468 				 * record with type !=
469 				 * application_data
470 				 */
471 				size = orig_size;
472 				destroy_record(record);
473 				ctx->open_record = NULL;
474 			} else if (record->len > prot->prepend_size) {
475 				goto last_record;
476 			}
477 
478 			break;
479 		}
480 
481 		record = ctx->open_record;
482 		copy = min_t(size_t, size, (pfrag->size - pfrag->offset));
483 		copy = min_t(size_t, copy, (max_open_record_len - record->len));
484 
485 		rc = tls_device_copy_data(page_address(pfrag->page) +
486 					  pfrag->offset, copy, msg_iter);
487 		if (rc)
488 			goto handle_error;
489 		tls_append_frag(record, pfrag, copy);
490 
491 		size -= copy;
492 		if (!size) {
493 last_record:
494 			tls_push_record_flags = flags;
495 			if (more) {
496 				tls_ctx->pending_open_record_frags =
497 						!!record->num_frags;
498 				break;
499 			}
500 
501 			done = true;
502 		}
503 
504 		if (done || record->len >= max_open_record_len ||
505 		    (record->num_frags >= MAX_SKB_FRAGS - 1)) {
506 			rc = tls_device_record_close(sk, tls_ctx, record,
507 						     pfrag, record_type);
508 			if (rc) {
509 				if (rc > 0) {
510 					size += rc;
511 				} else {
512 					size = orig_size;
513 					destroy_record(record);
514 					ctx->open_record = NULL;
515 					break;
516 				}
517 			}
518 
519 			rc = tls_push_record(sk,
520 					     tls_ctx,
521 					     ctx,
522 					     record,
523 					     tls_push_record_flags);
524 			if (rc < 0)
525 				break;
526 		}
527 	} while (!done);
528 
529 	if (orig_size - size > 0)
530 		rc = orig_size - size;
531 
532 	return rc;
533 }
534 
535 int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
536 {
537 	unsigned char record_type = TLS_RECORD_TYPE_DATA;
538 	struct tls_context *tls_ctx = tls_get_ctx(sk);
539 	int rc;
540 
541 	mutex_lock(&tls_ctx->tx_lock);
542 	lock_sock(sk);
543 
544 	if (unlikely(msg->msg_controllen)) {
545 		rc = tls_proccess_cmsg(sk, msg, &record_type);
546 		if (rc)
547 			goto out;
548 	}
549 
550 	rc = tls_push_data(sk, &msg->msg_iter, size,
551 			   msg->msg_flags, record_type);
552 
553 out:
554 	release_sock(sk);
555 	mutex_unlock(&tls_ctx->tx_lock);
556 	return rc;
557 }
558 
559 int tls_device_sendpage(struct sock *sk, struct page *page,
560 			int offset, size_t size, int flags)
561 {
562 	struct tls_context *tls_ctx = tls_get_ctx(sk);
563 	struct iov_iter	msg_iter;
564 	char *kaddr;
565 	struct kvec iov;
566 	int rc;
567 
568 	if (flags & MSG_SENDPAGE_NOTLAST)
569 		flags |= MSG_MORE;
570 
571 	mutex_lock(&tls_ctx->tx_lock);
572 	lock_sock(sk);
573 
574 	if (flags & MSG_OOB) {
575 		rc = -EOPNOTSUPP;
576 		goto out;
577 	}
578 
579 	kaddr = kmap(page);
580 	iov.iov_base = kaddr + offset;
581 	iov.iov_len = size;
582 	iov_iter_kvec(&msg_iter, WRITE, &iov, 1, size);
583 	rc = tls_push_data(sk, &msg_iter, size,
584 			   flags, TLS_RECORD_TYPE_DATA);
585 	kunmap(page);
586 
587 out:
588 	release_sock(sk);
589 	mutex_unlock(&tls_ctx->tx_lock);
590 	return rc;
591 }
592 
593 struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context,
594 				       u32 seq, u64 *p_record_sn)
595 {
596 	u64 record_sn = context->hint_record_sn;
597 	struct tls_record_info *info, *last;
598 
599 	info = context->retransmit_hint;
600 	if (!info ||
601 	    before(seq, info->end_seq - info->len)) {
602 		/* if retransmit_hint is irrelevant start
603 		 * from the beggining of the list
604 		 */
605 		info = list_first_entry_or_null(&context->records_list,
606 						struct tls_record_info, list);
607 		if (!info)
608 			return NULL;
609 		/* send the start_marker record if seq number is before the
610 		 * tls offload start marker sequence number. This record is
611 		 * required to handle TCP packets which are before TLS offload
612 		 * started.
613 		 *  And if it's not start marker, look if this seq number
614 		 * belongs to the list.
615 		 */
616 		if (likely(!tls_record_is_start_marker(info))) {
617 			/* we have the first record, get the last record to see
618 			 * if this seq number belongs to the list.
619 			 */
620 			last = list_last_entry(&context->records_list,
621 					       struct tls_record_info, list);
622 
623 			if (!between(seq, tls_record_start_seq(info),
624 				     last->end_seq))
625 				return NULL;
626 		}
627 		record_sn = context->unacked_record_sn;
628 	}
629 
630 	/* We just need the _rcu for the READ_ONCE() */
631 	rcu_read_lock();
632 	list_for_each_entry_from_rcu(info, &context->records_list, list) {
633 		if (before(seq, info->end_seq)) {
634 			if (!context->retransmit_hint ||
635 			    after(info->end_seq,
636 				  context->retransmit_hint->end_seq)) {
637 				context->hint_record_sn = record_sn;
638 				context->retransmit_hint = info;
639 			}
640 			*p_record_sn = record_sn;
641 			goto exit_rcu_unlock;
642 		}
643 		record_sn++;
644 	}
645 	info = NULL;
646 
647 exit_rcu_unlock:
648 	rcu_read_unlock();
649 	return info;
650 }
651 EXPORT_SYMBOL(tls_get_record);
652 
653 static int tls_device_push_pending_record(struct sock *sk, int flags)
654 {
655 	struct iov_iter	msg_iter;
656 
657 	iov_iter_kvec(&msg_iter, WRITE, NULL, 0, 0);
658 	return tls_push_data(sk, &msg_iter, 0, flags, TLS_RECORD_TYPE_DATA);
659 }
660 
661 void tls_device_write_space(struct sock *sk, struct tls_context *ctx)
662 {
663 	if (tls_is_partially_sent_record(ctx)) {
664 		gfp_t sk_allocation = sk->sk_allocation;
665 
666 		WARN_ON_ONCE(sk->sk_write_pending);
667 
668 		sk->sk_allocation = GFP_ATOMIC;
669 		tls_push_partial_record(sk, ctx,
670 					MSG_DONTWAIT | MSG_NOSIGNAL |
671 					MSG_SENDPAGE_DECRYPTED);
672 		sk->sk_allocation = sk_allocation;
673 	}
674 }
675 
676 static void tls_device_resync_rx(struct tls_context *tls_ctx,
677 				 struct sock *sk, u32 seq, u8 *rcd_sn)
678 {
679 	struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
680 	struct net_device *netdev;
681 
682 	if (WARN_ON(test_and_set_bit(TLS_RX_SYNC_RUNNING, &tls_ctx->flags)))
683 		return;
684 
685 	trace_tls_device_rx_resync_send(sk, seq, rcd_sn, rx_ctx->resync_type);
686 	netdev = READ_ONCE(tls_ctx->netdev);
687 	if (netdev)
688 		netdev->tlsdev_ops->tls_dev_resync(netdev, sk, seq, rcd_sn,
689 						   TLS_OFFLOAD_CTX_DIR_RX);
690 	clear_bit_unlock(TLS_RX_SYNC_RUNNING, &tls_ctx->flags);
691 	TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSRXDEVICERESYNC);
692 }
693 
694 static bool
695 tls_device_rx_resync_async(struct tls_offload_resync_async *resync_async,
696 			   s64 resync_req, u32 *seq)
697 {
698 	u32 is_async = resync_req & RESYNC_REQ_ASYNC;
699 	u32 req_seq = resync_req >> 32;
700 	u32 req_end = req_seq + ((resync_req >> 16) & 0xffff);
701 
702 	if (is_async) {
703 		/* asynchronous stage: log all headers seq such that
704 		 * req_seq <= seq <= end_seq, and wait for real resync request
705 		 */
706 		if (between(*seq, req_seq, req_end) &&
707 		    resync_async->loglen < TLS_DEVICE_RESYNC_ASYNC_LOGMAX)
708 			resync_async->log[resync_async->loglen++] = *seq;
709 
710 		return false;
711 	}
712 
713 	/* synchronous stage: check against the logged entries and
714 	 * proceed to check the next entries if no match was found
715 	 */
716 	while (resync_async->loglen) {
717 		if (req_seq == resync_async->log[resync_async->loglen - 1] &&
718 		    atomic64_try_cmpxchg(&resync_async->req,
719 					 &resync_req, 0)) {
720 			resync_async->loglen = 0;
721 			*seq = req_seq;
722 			return true;
723 		}
724 		resync_async->loglen--;
725 	}
726 
727 	if (req_seq == *seq &&
728 	    atomic64_try_cmpxchg(&resync_async->req,
729 				 &resync_req, 0))
730 		return true;
731 
732 	return false;
733 }
734 
735 void tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq)
736 {
737 	struct tls_context *tls_ctx = tls_get_ctx(sk);
738 	struct tls_offload_context_rx *rx_ctx;
739 	u8 rcd_sn[TLS_MAX_REC_SEQ_SIZE];
740 	u32 sock_data, is_req_pending;
741 	struct tls_prot_info *prot;
742 	s64 resync_req;
743 	u32 req_seq;
744 
745 	if (tls_ctx->rx_conf != TLS_HW)
746 		return;
747 
748 	prot = &tls_ctx->prot_info;
749 	rx_ctx = tls_offload_ctx_rx(tls_ctx);
750 	memcpy(rcd_sn, tls_ctx->rx.rec_seq, prot->rec_seq_size);
751 
752 	switch (rx_ctx->resync_type) {
753 	case TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ:
754 		resync_req = atomic64_read(&rx_ctx->resync_req);
755 		req_seq = resync_req >> 32;
756 		seq += TLS_HEADER_SIZE - 1;
757 		is_req_pending = resync_req;
758 
759 		if (likely(!is_req_pending) || req_seq != seq ||
760 		    !atomic64_try_cmpxchg(&rx_ctx->resync_req, &resync_req, 0))
761 			return;
762 		break;
763 	case TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT:
764 		if (likely(!rx_ctx->resync_nh_do_now))
765 			return;
766 
767 		/* head of next rec is already in, note that the sock_inq will
768 		 * include the currently parsed message when called from parser
769 		 */
770 		sock_data = tcp_inq(sk);
771 		if (sock_data > rcd_len) {
772 			trace_tls_device_rx_resync_nh_delay(sk, sock_data,
773 							    rcd_len);
774 			return;
775 		}
776 
777 		rx_ctx->resync_nh_do_now = 0;
778 		seq += rcd_len;
779 		tls_bigint_increment(rcd_sn, prot->rec_seq_size);
780 		break;
781 	case TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ_ASYNC:
782 		resync_req = atomic64_read(&rx_ctx->resync_async->req);
783 		is_req_pending = resync_req;
784 		if (likely(!is_req_pending))
785 			return;
786 
787 		if (!tls_device_rx_resync_async(rx_ctx->resync_async,
788 						resync_req, &seq))
789 			return;
790 		break;
791 	}
792 
793 	tls_device_resync_rx(tls_ctx, sk, seq, rcd_sn);
794 }
795 
796 static void tls_device_core_ctrl_rx_resync(struct tls_context *tls_ctx,
797 					   struct tls_offload_context_rx *ctx,
798 					   struct sock *sk, struct sk_buff *skb)
799 {
800 	struct strp_msg *rxm;
801 
802 	/* device will request resyncs by itself based on stream scan */
803 	if (ctx->resync_type != TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT)
804 		return;
805 	/* already scheduled */
806 	if (ctx->resync_nh_do_now)
807 		return;
808 	/* seen decrypted fragments since last fully-failed record */
809 	if (ctx->resync_nh_reset) {
810 		ctx->resync_nh_reset = 0;
811 		ctx->resync_nh.decrypted_failed = 1;
812 		ctx->resync_nh.decrypted_tgt = TLS_DEVICE_RESYNC_NH_START_IVAL;
813 		return;
814 	}
815 
816 	if (++ctx->resync_nh.decrypted_failed <= ctx->resync_nh.decrypted_tgt)
817 		return;
818 
819 	/* doing resync, bump the next target in case it fails */
820 	if (ctx->resync_nh.decrypted_tgt < TLS_DEVICE_RESYNC_NH_MAX_IVAL)
821 		ctx->resync_nh.decrypted_tgt *= 2;
822 	else
823 		ctx->resync_nh.decrypted_tgt += TLS_DEVICE_RESYNC_NH_MAX_IVAL;
824 
825 	rxm = strp_msg(skb);
826 
827 	/* head of next rec is already in, parser will sync for us */
828 	if (tcp_inq(sk) > rxm->full_len) {
829 		trace_tls_device_rx_resync_nh_schedule(sk);
830 		ctx->resync_nh_do_now = 1;
831 	} else {
832 		struct tls_prot_info *prot = &tls_ctx->prot_info;
833 		u8 rcd_sn[TLS_MAX_REC_SEQ_SIZE];
834 
835 		memcpy(rcd_sn, tls_ctx->rx.rec_seq, prot->rec_seq_size);
836 		tls_bigint_increment(rcd_sn, prot->rec_seq_size);
837 
838 		tls_device_resync_rx(tls_ctx, sk, tcp_sk(sk)->copied_seq,
839 				     rcd_sn);
840 	}
841 }
842 
843 static int tls_device_reencrypt(struct sock *sk, struct sk_buff *skb)
844 {
845 	struct strp_msg *rxm = strp_msg(skb);
846 	int err = 0, offset = rxm->offset, copy, nsg, data_len, pos;
847 	struct sk_buff *skb_iter, *unused;
848 	struct scatterlist sg[1];
849 	char *orig_buf, *buf;
850 
851 	orig_buf = kmalloc(rxm->full_len + TLS_HEADER_SIZE +
852 			   TLS_CIPHER_AES_GCM_128_IV_SIZE, sk->sk_allocation);
853 	if (!orig_buf)
854 		return -ENOMEM;
855 	buf = orig_buf;
856 
857 	nsg = skb_cow_data(skb, 0, &unused);
858 	if (unlikely(nsg < 0)) {
859 		err = nsg;
860 		goto free_buf;
861 	}
862 
863 	sg_init_table(sg, 1);
864 	sg_set_buf(&sg[0], buf,
865 		   rxm->full_len + TLS_HEADER_SIZE +
866 		   TLS_CIPHER_AES_GCM_128_IV_SIZE);
867 	err = skb_copy_bits(skb, offset, buf,
868 			    TLS_HEADER_SIZE + TLS_CIPHER_AES_GCM_128_IV_SIZE);
869 	if (err)
870 		goto free_buf;
871 
872 	/* We are interested only in the decrypted data not the auth */
873 	err = decrypt_skb(sk, skb, sg);
874 	if (err != -EBADMSG)
875 		goto free_buf;
876 	else
877 		err = 0;
878 
879 	data_len = rxm->full_len - TLS_CIPHER_AES_GCM_128_TAG_SIZE;
880 
881 	if (skb_pagelen(skb) > offset) {
882 		copy = min_t(int, skb_pagelen(skb) - offset, data_len);
883 
884 		if (skb->decrypted) {
885 			err = skb_store_bits(skb, offset, buf, copy);
886 			if (err)
887 				goto free_buf;
888 		}
889 
890 		offset += copy;
891 		buf += copy;
892 	}
893 
894 	pos = skb_pagelen(skb);
895 	skb_walk_frags(skb, skb_iter) {
896 		int frag_pos;
897 
898 		/* Practically all frags must belong to msg if reencrypt
899 		 * is needed with current strparser and coalescing logic,
900 		 * but strparser may "get optimized", so let's be safe.
901 		 */
902 		if (pos + skb_iter->len <= offset)
903 			goto done_with_frag;
904 		if (pos >= data_len + rxm->offset)
905 			break;
906 
907 		frag_pos = offset - pos;
908 		copy = min_t(int, skb_iter->len - frag_pos,
909 			     data_len + rxm->offset - offset);
910 
911 		if (skb_iter->decrypted) {
912 			err = skb_store_bits(skb_iter, frag_pos, buf, copy);
913 			if (err)
914 				goto free_buf;
915 		}
916 
917 		offset += copy;
918 		buf += copy;
919 done_with_frag:
920 		pos += skb_iter->len;
921 	}
922 
923 free_buf:
924 	kfree(orig_buf);
925 	return err;
926 }
927 
928 int tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx,
929 			 struct sk_buff *skb, struct strp_msg *rxm)
930 {
931 	struct tls_offload_context_rx *ctx = tls_offload_ctx_rx(tls_ctx);
932 	int is_decrypted = skb->decrypted;
933 	int is_encrypted = !is_decrypted;
934 	struct sk_buff *skb_iter;
935 
936 	/* Check if all the data is decrypted already */
937 	skb_walk_frags(skb, skb_iter) {
938 		is_decrypted &= skb_iter->decrypted;
939 		is_encrypted &= !skb_iter->decrypted;
940 	}
941 
942 	trace_tls_device_decrypted(sk, tcp_sk(sk)->copied_seq - rxm->full_len,
943 				   tls_ctx->rx.rec_seq, rxm->full_len,
944 				   is_encrypted, is_decrypted);
945 
946 	ctx->sw.decrypted |= is_decrypted;
947 
948 	/* Return immediately if the record is either entirely plaintext or
949 	 * entirely ciphertext. Otherwise handle reencrypt partially decrypted
950 	 * record.
951 	 */
952 	if (is_decrypted) {
953 		ctx->resync_nh_reset = 1;
954 		return 0;
955 	}
956 	if (is_encrypted) {
957 		tls_device_core_ctrl_rx_resync(tls_ctx, ctx, sk, skb);
958 		return 0;
959 	}
960 
961 	ctx->resync_nh_reset = 1;
962 	return tls_device_reencrypt(sk, skb);
963 }
964 
965 static void tls_device_attach(struct tls_context *ctx, struct sock *sk,
966 			      struct net_device *netdev)
967 {
968 	if (sk->sk_destruct != tls_device_sk_destruct) {
969 		refcount_set(&ctx->refcount, 1);
970 		dev_hold(netdev);
971 		ctx->netdev = netdev;
972 		spin_lock_irq(&tls_device_lock);
973 		list_add_tail(&ctx->list, &tls_device_list);
974 		spin_unlock_irq(&tls_device_lock);
975 
976 		ctx->sk_destruct = sk->sk_destruct;
977 		smp_store_release(&sk->sk_destruct, tls_device_sk_destruct);
978 	}
979 }
980 
981 int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
982 {
983 	u16 nonce_size, tag_size, iv_size, rec_seq_size;
984 	struct tls_context *tls_ctx = tls_get_ctx(sk);
985 	struct tls_prot_info *prot = &tls_ctx->prot_info;
986 	struct tls_record_info *start_marker_record;
987 	struct tls_offload_context_tx *offload_ctx;
988 	struct tls_crypto_info *crypto_info;
989 	struct net_device *netdev;
990 	char *iv, *rec_seq;
991 	struct sk_buff *skb;
992 	__be64 rcd_sn;
993 	int rc;
994 
995 	if (!ctx)
996 		return -EINVAL;
997 
998 	if (ctx->priv_ctx_tx)
999 		return -EEXIST;
1000 
1001 	start_marker_record = kmalloc(sizeof(*start_marker_record), GFP_KERNEL);
1002 	if (!start_marker_record)
1003 		return -ENOMEM;
1004 
1005 	offload_ctx = kzalloc(TLS_OFFLOAD_CONTEXT_SIZE_TX, GFP_KERNEL);
1006 	if (!offload_ctx) {
1007 		rc = -ENOMEM;
1008 		goto free_marker_record;
1009 	}
1010 
1011 	crypto_info = &ctx->crypto_send.info;
1012 	if (crypto_info->version != TLS_1_2_VERSION) {
1013 		rc = -EOPNOTSUPP;
1014 		goto free_offload_ctx;
1015 	}
1016 
1017 	switch (crypto_info->cipher_type) {
1018 	case TLS_CIPHER_AES_GCM_128:
1019 		nonce_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
1020 		tag_size = TLS_CIPHER_AES_GCM_128_TAG_SIZE;
1021 		iv_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
1022 		iv = ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->iv;
1023 		rec_seq_size = TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE;
1024 		rec_seq =
1025 		 ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->rec_seq;
1026 		break;
1027 	default:
1028 		rc = -EINVAL;
1029 		goto free_offload_ctx;
1030 	}
1031 
1032 	/* Sanity-check the rec_seq_size for stack allocations */
1033 	if (rec_seq_size > TLS_MAX_REC_SEQ_SIZE) {
1034 		rc = -EINVAL;
1035 		goto free_offload_ctx;
1036 	}
1037 
1038 	prot->version = crypto_info->version;
1039 	prot->cipher_type = crypto_info->cipher_type;
1040 	prot->prepend_size = TLS_HEADER_SIZE + nonce_size;
1041 	prot->tag_size = tag_size;
1042 	prot->overhead_size = prot->prepend_size + prot->tag_size;
1043 	prot->iv_size = iv_size;
1044 	ctx->tx.iv = kmalloc(iv_size + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
1045 			     GFP_KERNEL);
1046 	if (!ctx->tx.iv) {
1047 		rc = -ENOMEM;
1048 		goto free_offload_ctx;
1049 	}
1050 
1051 	memcpy(ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv, iv_size);
1052 
1053 	prot->rec_seq_size = rec_seq_size;
1054 	ctx->tx.rec_seq = kmemdup(rec_seq, rec_seq_size, GFP_KERNEL);
1055 	if (!ctx->tx.rec_seq) {
1056 		rc = -ENOMEM;
1057 		goto free_iv;
1058 	}
1059 
1060 	rc = tls_sw_fallback_init(sk, offload_ctx, crypto_info);
1061 	if (rc)
1062 		goto free_rec_seq;
1063 
1064 	/* start at rec_seq - 1 to account for the start marker record */
1065 	memcpy(&rcd_sn, ctx->tx.rec_seq, sizeof(rcd_sn));
1066 	offload_ctx->unacked_record_sn = be64_to_cpu(rcd_sn) - 1;
1067 
1068 	start_marker_record->end_seq = tcp_sk(sk)->write_seq;
1069 	start_marker_record->len = 0;
1070 	start_marker_record->num_frags = 0;
1071 
1072 	INIT_LIST_HEAD(&offload_ctx->records_list);
1073 	list_add_tail(&start_marker_record->list, &offload_ctx->records_list);
1074 	spin_lock_init(&offload_ctx->lock);
1075 	sg_init_table(offload_ctx->sg_tx_data,
1076 		      ARRAY_SIZE(offload_ctx->sg_tx_data));
1077 
1078 	clean_acked_data_enable(inet_csk(sk), &tls_icsk_clean_acked);
1079 	ctx->push_pending_record = tls_device_push_pending_record;
1080 
1081 	/* TLS offload is greatly simplified if we don't send
1082 	 * SKBs where only part of the payload needs to be encrypted.
1083 	 * So mark the last skb in the write queue as end of record.
1084 	 */
1085 	skb = tcp_write_queue_tail(sk);
1086 	if (skb)
1087 		TCP_SKB_CB(skb)->eor = 1;
1088 
1089 	netdev = get_netdev_for_sock(sk);
1090 	if (!netdev) {
1091 		pr_err_ratelimited("%s: netdev not found\n", __func__);
1092 		rc = -EINVAL;
1093 		goto disable_cad;
1094 	}
1095 
1096 	if (!(netdev->features & NETIF_F_HW_TLS_TX)) {
1097 		rc = -EOPNOTSUPP;
1098 		goto release_netdev;
1099 	}
1100 
1101 	/* Avoid offloading if the device is down
1102 	 * We don't want to offload new flows after
1103 	 * the NETDEV_DOWN event
1104 	 *
1105 	 * device_offload_lock is taken in tls_devices's NETDEV_DOWN
1106 	 * handler thus protecting from the device going down before
1107 	 * ctx was added to tls_device_list.
1108 	 */
1109 	down_read(&device_offload_lock);
1110 	if (!(netdev->flags & IFF_UP)) {
1111 		rc = -EINVAL;
1112 		goto release_lock;
1113 	}
1114 
1115 	ctx->priv_ctx_tx = offload_ctx;
1116 	rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_TX,
1117 					     &ctx->crypto_send.info,
1118 					     tcp_sk(sk)->write_seq);
1119 	trace_tls_device_offload_set(sk, TLS_OFFLOAD_CTX_DIR_TX,
1120 				     tcp_sk(sk)->write_seq, rec_seq, rc);
1121 	if (rc)
1122 		goto release_lock;
1123 
1124 	tls_device_attach(ctx, sk, netdev);
1125 	up_read(&device_offload_lock);
1126 
1127 	/* following this assignment tls_is_sk_tx_device_offloaded
1128 	 * will return true and the context might be accessed
1129 	 * by the netdev's xmit function.
1130 	 */
1131 	smp_store_release(&sk->sk_validate_xmit_skb, tls_validate_xmit_skb);
1132 	dev_put(netdev);
1133 
1134 	return 0;
1135 
1136 release_lock:
1137 	up_read(&device_offload_lock);
1138 release_netdev:
1139 	dev_put(netdev);
1140 disable_cad:
1141 	clean_acked_data_disable(inet_csk(sk));
1142 	crypto_free_aead(offload_ctx->aead_send);
1143 free_rec_seq:
1144 	kfree(ctx->tx.rec_seq);
1145 free_iv:
1146 	kfree(ctx->tx.iv);
1147 free_offload_ctx:
1148 	kfree(offload_ctx);
1149 	ctx->priv_ctx_tx = NULL;
1150 free_marker_record:
1151 	kfree(start_marker_record);
1152 	return rc;
1153 }
1154 
1155 int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
1156 {
1157 	struct tls12_crypto_info_aes_gcm_128 *info;
1158 	struct tls_offload_context_rx *context;
1159 	struct net_device *netdev;
1160 	int rc = 0;
1161 
1162 	if (ctx->crypto_recv.info.version != TLS_1_2_VERSION)
1163 		return -EOPNOTSUPP;
1164 
1165 	netdev = get_netdev_for_sock(sk);
1166 	if (!netdev) {
1167 		pr_err_ratelimited("%s: netdev not found\n", __func__);
1168 		return -EINVAL;
1169 	}
1170 
1171 	if (!(netdev->features & NETIF_F_HW_TLS_RX)) {
1172 		rc = -EOPNOTSUPP;
1173 		goto release_netdev;
1174 	}
1175 
1176 	/* Avoid offloading if the device is down
1177 	 * We don't want to offload new flows after
1178 	 * the NETDEV_DOWN event
1179 	 *
1180 	 * device_offload_lock is taken in tls_devices's NETDEV_DOWN
1181 	 * handler thus protecting from the device going down before
1182 	 * ctx was added to tls_device_list.
1183 	 */
1184 	down_read(&device_offload_lock);
1185 	if (!(netdev->flags & IFF_UP)) {
1186 		rc = -EINVAL;
1187 		goto release_lock;
1188 	}
1189 
1190 	context = kzalloc(TLS_OFFLOAD_CONTEXT_SIZE_RX, GFP_KERNEL);
1191 	if (!context) {
1192 		rc = -ENOMEM;
1193 		goto release_lock;
1194 	}
1195 	context->resync_nh_reset = 1;
1196 
1197 	ctx->priv_ctx_rx = context;
1198 	rc = tls_set_sw_offload(sk, ctx, 0);
1199 	if (rc)
1200 		goto release_ctx;
1201 
1202 	rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_RX,
1203 					     &ctx->crypto_recv.info,
1204 					     tcp_sk(sk)->copied_seq);
1205 	info = (void *)&ctx->crypto_recv.info;
1206 	trace_tls_device_offload_set(sk, TLS_OFFLOAD_CTX_DIR_RX,
1207 				     tcp_sk(sk)->copied_seq, info->rec_seq, rc);
1208 	if (rc)
1209 		goto free_sw_resources;
1210 
1211 	tls_device_attach(ctx, sk, netdev);
1212 	up_read(&device_offload_lock);
1213 
1214 	dev_put(netdev);
1215 
1216 	return 0;
1217 
1218 free_sw_resources:
1219 	up_read(&device_offload_lock);
1220 	tls_sw_free_resources_rx(sk);
1221 	down_read(&device_offload_lock);
1222 release_ctx:
1223 	ctx->priv_ctx_rx = NULL;
1224 release_lock:
1225 	up_read(&device_offload_lock);
1226 release_netdev:
1227 	dev_put(netdev);
1228 	return rc;
1229 }
1230 
1231 void tls_device_offload_cleanup_rx(struct sock *sk)
1232 {
1233 	struct tls_context *tls_ctx = tls_get_ctx(sk);
1234 	struct net_device *netdev;
1235 
1236 	down_read(&device_offload_lock);
1237 	netdev = tls_ctx->netdev;
1238 	if (!netdev)
1239 		goto out;
1240 
1241 	netdev->tlsdev_ops->tls_dev_del(netdev, tls_ctx,
1242 					TLS_OFFLOAD_CTX_DIR_RX);
1243 
1244 	if (tls_ctx->tx_conf != TLS_HW) {
1245 		dev_put(netdev);
1246 		tls_ctx->netdev = NULL;
1247 	}
1248 out:
1249 	up_read(&device_offload_lock);
1250 	tls_sw_release_resources_rx(sk);
1251 }
1252 
1253 static int tls_device_down(struct net_device *netdev)
1254 {
1255 	struct tls_context *ctx, *tmp;
1256 	unsigned long flags;
1257 	LIST_HEAD(list);
1258 
1259 	/* Request a write lock to block new offload attempts */
1260 	down_write(&device_offload_lock);
1261 
1262 	spin_lock_irqsave(&tls_device_lock, flags);
1263 	list_for_each_entry_safe(ctx, tmp, &tls_device_list, list) {
1264 		if (ctx->netdev != netdev ||
1265 		    !refcount_inc_not_zero(&ctx->refcount))
1266 			continue;
1267 
1268 		list_move(&ctx->list, &list);
1269 	}
1270 	spin_unlock_irqrestore(&tls_device_lock, flags);
1271 
1272 	list_for_each_entry_safe(ctx, tmp, &list, list)	{
1273 		if (ctx->tx_conf == TLS_HW)
1274 			netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
1275 							TLS_OFFLOAD_CTX_DIR_TX);
1276 		if (ctx->rx_conf == TLS_HW)
1277 			netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
1278 							TLS_OFFLOAD_CTX_DIR_RX);
1279 		WRITE_ONCE(ctx->netdev, NULL);
1280 		smp_mb__before_atomic(); /* pairs with test_and_set_bit() */
1281 		while (test_bit(TLS_RX_SYNC_RUNNING, &ctx->flags))
1282 			usleep_range(10, 200);
1283 		dev_put(netdev);
1284 		list_del_init(&ctx->list);
1285 
1286 		if (refcount_dec_and_test(&ctx->refcount))
1287 			tls_device_free_ctx(ctx);
1288 	}
1289 
1290 	up_write(&device_offload_lock);
1291 
1292 	flush_work(&tls_device_gc_work);
1293 
1294 	return NOTIFY_DONE;
1295 }
1296 
1297 static int tls_dev_event(struct notifier_block *this, unsigned long event,
1298 			 void *ptr)
1299 {
1300 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1301 
1302 	if (!dev->tlsdev_ops &&
1303 	    !(dev->features & (NETIF_F_HW_TLS_RX | NETIF_F_HW_TLS_TX)))
1304 		return NOTIFY_DONE;
1305 
1306 	switch (event) {
1307 	case NETDEV_REGISTER:
1308 	case NETDEV_FEAT_CHANGE:
1309 		if ((dev->features & NETIF_F_HW_TLS_RX) &&
1310 		    !dev->tlsdev_ops->tls_dev_resync)
1311 			return NOTIFY_BAD;
1312 
1313 		if  (dev->tlsdev_ops &&
1314 		     dev->tlsdev_ops->tls_dev_add &&
1315 		     dev->tlsdev_ops->tls_dev_del)
1316 			return NOTIFY_DONE;
1317 		else
1318 			return NOTIFY_BAD;
1319 	case NETDEV_DOWN:
1320 		return tls_device_down(dev);
1321 	}
1322 	return NOTIFY_DONE;
1323 }
1324 
1325 static struct notifier_block tls_dev_notifier = {
1326 	.notifier_call	= tls_dev_event,
1327 };
1328 
1329 void __init tls_device_init(void)
1330 {
1331 	register_netdevice_notifier(&tls_dev_notifier);
1332 }
1333 
1334 void __exit tls_device_cleanup(void)
1335 {
1336 	unregister_netdevice_notifier(&tls_dev_notifier);
1337 	flush_work(&tls_device_gc_work);
1338 	clean_acked_data_flush();
1339 }
1340