xref: /linux/net/tls/tls_device.c (revision 409c188c57cdb5cb1dfcac79e72b5169f0463fe4)
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 "tls.h"
42 #include "trace.h"
43 
44 /* device_offload_lock is used to synchronize tls_dev_add
45  * against NETDEV_DOWN notifications.
46  */
47 static DECLARE_RWSEM(device_offload_lock);
48 
49 static void tls_device_gc_task(struct work_struct *work);
50 
51 static DECLARE_WORK(tls_device_gc_work, tls_device_gc_task);
52 static LIST_HEAD(tls_device_gc_list);
53 static LIST_HEAD(tls_device_list);
54 static LIST_HEAD(tls_device_down_list);
55 static DEFINE_SPINLOCK(tls_device_lock);
56 
57 static void tls_device_free_ctx(struct tls_context *ctx)
58 {
59 	if (ctx->tx_conf == TLS_HW) {
60 		kfree(tls_offload_ctx_tx(ctx));
61 		kfree(ctx->tx.rec_seq);
62 		kfree(ctx->tx.iv);
63 	}
64 
65 	if (ctx->rx_conf == TLS_HW)
66 		kfree(tls_offload_ctx_rx(ctx));
67 
68 	tls_ctx_free(NULL, ctx);
69 }
70 
71 static void tls_device_gc_task(struct work_struct *work)
72 {
73 	struct tls_context *ctx, *tmp;
74 	unsigned long flags;
75 	LIST_HEAD(gc_list);
76 
77 	spin_lock_irqsave(&tls_device_lock, flags);
78 	list_splice_init(&tls_device_gc_list, &gc_list);
79 	spin_unlock_irqrestore(&tls_device_lock, flags);
80 
81 	list_for_each_entry_safe(ctx, tmp, &gc_list, list) {
82 		struct net_device *netdev = ctx->netdev;
83 
84 		if (netdev && ctx->tx_conf == TLS_HW) {
85 			netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
86 							TLS_OFFLOAD_CTX_DIR_TX);
87 			dev_put(netdev);
88 			ctx->netdev = NULL;
89 		}
90 
91 		list_del(&ctx->list);
92 		tls_device_free_ctx(ctx);
93 	}
94 }
95 
96 static void tls_device_queue_ctx_destruction(struct tls_context *ctx)
97 {
98 	unsigned long flags;
99 
100 	spin_lock_irqsave(&tls_device_lock, flags);
101 	if (unlikely(!refcount_dec_and_test(&ctx->refcount)))
102 		goto unlock;
103 
104 	list_move_tail(&ctx->list, &tls_device_gc_list);
105 
106 	/* schedule_work inside the spinlock
107 	 * to make sure tls_device_down waits for that work.
108 	 */
109 	schedule_work(&tls_device_gc_work);
110 unlock:
111 	spin_unlock_irqrestore(&tls_device_lock, flags);
112 }
113 
114 /* We assume that the socket is already connected */
115 static struct net_device *get_netdev_for_sock(struct sock *sk)
116 {
117 	struct dst_entry *dst = sk_dst_get(sk);
118 	struct net_device *netdev = NULL;
119 
120 	if (likely(dst)) {
121 		netdev = netdev_sk_get_lowest_dev(dst->dev, sk);
122 		dev_hold(netdev);
123 	}
124 
125 	dst_release(dst);
126 
127 	return netdev;
128 }
129 
130 static void destroy_record(struct tls_record_info *record)
131 {
132 	int i;
133 
134 	for (i = 0; i < record->num_frags; i++)
135 		__skb_frag_unref(&record->frags[i], false);
136 	kfree(record);
137 }
138 
139 static void delete_all_records(struct tls_offload_context_tx *offload_ctx)
140 {
141 	struct tls_record_info *info, *temp;
142 
143 	list_for_each_entry_safe(info, temp, &offload_ctx->records_list, list) {
144 		list_del(&info->list);
145 		destroy_record(info);
146 	}
147 
148 	offload_ctx->retransmit_hint = NULL;
149 }
150 
151 static void tls_icsk_clean_acked(struct sock *sk, u32 acked_seq)
152 {
153 	struct tls_context *tls_ctx = tls_get_ctx(sk);
154 	struct tls_record_info *info, *temp;
155 	struct tls_offload_context_tx *ctx;
156 	u64 deleted_records = 0;
157 	unsigned long flags;
158 
159 	if (!tls_ctx)
160 		return;
161 
162 	ctx = tls_offload_ctx_tx(tls_ctx);
163 
164 	spin_lock_irqsave(&ctx->lock, flags);
165 	info = ctx->retransmit_hint;
166 	if (info && !before(acked_seq, info->end_seq))
167 		ctx->retransmit_hint = NULL;
168 
169 	list_for_each_entry_safe(info, temp, &ctx->records_list, list) {
170 		if (before(acked_seq, info->end_seq))
171 			break;
172 		list_del(&info->list);
173 
174 		destroy_record(info);
175 		deleted_records++;
176 	}
177 
178 	ctx->unacked_record_sn += deleted_records;
179 	spin_unlock_irqrestore(&ctx->lock, flags);
180 }
181 
182 /* At this point, there should be no references on this
183  * socket and no in-flight SKBs associated with this
184  * socket, so it is safe to free all the resources.
185  */
186 void tls_device_sk_destruct(struct sock *sk)
187 {
188 	struct tls_context *tls_ctx = tls_get_ctx(sk);
189 	struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
190 
191 	tls_ctx->sk_destruct(sk);
192 
193 	if (tls_ctx->tx_conf == TLS_HW) {
194 		if (ctx->open_record)
195 			destroy_record(ctx->open_record);
196 		delete_all_records(ctx);
197 		crypto_free_aead(ctx->aead_send);
198 		clean_acked_data_disable(inet_csk(sk));
199 	}
200 
201 	tls_device_queue_ctx_destruction(tls_ctx);
202 }
203 EXPORT_SYMBOL_GPL(tls_device_sk_destruct);
204 
205 void tls_device_free_resources_tx(struct sock *sk)
206 {
207 	struct tls_context *tls_ctx = tls_get_ctx(sk);
208 
209 	tls_free_partial_record(sk, tls_ctx);
210 }
211 
212 void tls_offload_tx_resync_request(struct sock *sk, u32 got_seq, u32 exp_seq)
213 {
214 	struct tls_context *tls_ctx = tls_get_ctx(sk);
215 
216 	trace_tls_device_tx_resync_req(sk, got_seq, exp_seq);
217 	WARN_ON(test_and_set_bit(TLS_TX_SYNC_SCHED, &tls_ctx->flags));
218 }
219 EXPORT_SYMBOL_GPL(tls_offload_tx_resync_request);
220 
221 static void tls_device_resync_tx(struct sock *sk, struct tls_context *tls_ctx,
222 				 u32 seq)
223 {
224 	struct net_device *netdev;
225 	struct sk_buff *skb;
226 	int err = 0;
227 	u8 *rcd_sn;
228 
229 	skb = tcp_write_queue_tail(sk);
230 	if (skb)
231 		TCP_SKB_CB(skb)->eor = 1;
232 
233 	rcd_sn = tls_ctx->tx.rec_seq;
234 
235 	trace_tls_device_tx_resync_send(sk, seq, rcd_sn);
236 	down_read(&device_offload_lock);
237 	netdev = tls_ctx->netdev;
238 	if (netdev)
239 		err = netdev->tlsdev_ops->tls_dev_resync(netdev, sk, seq,
240 							 rcd_sn,
241 							 TLS_OFFLOAD_CTX_DIR_TX);
242 	up_read(&device_offload_lock);
243 	if (err)
244 		return;
245 
246 	clear_bit_unlock(TLS_TX_SYNC_SCHED, &tls_ctx->flags);
247 }
248 
249 static void tls_append_frag(struct tls_record_info *record,
250 			    struct page_frag *pfrag,
251 			    int size)
252 {
253 	skb_frag_t *frag;
254 
255 	frag = &record->frags[record->num_frags - 1];
256 	if (skb_frag_page(frag) == pfrag->page &&
257 	    skb_frag_off(frag) + skb_frag_size(frag) == pfrag->offset) {
258 		skb_frag_size_add(frag, size);
259 	} else {
260 		++frag;
261 		__skb_frag_set_page(frag, pfrag->page);
262 		skb_frag_off_set(frag, pfrag->offset);
263 		skb_frag_size_set(frag, size);
264 		++record->num_frags;
265 		get_page(pfrag->page);
266 	}
267 
268 	pfrag->offset += size;
269 	record->len += size;
270 }
271 
272 static int tls_push_record(struct sock *sk,
273 			   struct tls_context *ctx,
274 			   struct tls_offload_context_tx *offload_ctx,
275 			   struct tls_record_info *record,
276 			   int flags)
277 {
278 	struct tls_prot_info *prot = &ctx->prot_info;
279 	struct tcp_sock *tp = tcp_sk(sk);
280 	skb_frag_t *frag;
281 	int i;
282 
283 	record->end_seq = tp->write_seq + record->len;
284 	list_add_tail_rcu(&record->list, &offload_ctx->records_list);
285 	offload_ctx->open_record = NULL;
286 
287 	if (test_bit(TLS_TX_SYNC_SCHED, &ctx->flags))
288 		tls_device_resync_tx(sk, ctx, tp->write_seq);
289 
290 	tls_advance_record_sn(sk, prot, &ctx->tx);
291 
292 	for (i = 0; i < record->num_frags; i++) {
293 		frag = &record->frags[i];
294 		sg_unmark_end(&offload_ctx->sg_tx_data[i]);
295 		sg_set_page(&offload_ctx->sg_tx_data[i], skb_frag_page(frag),
296 			    skb_frag_size(frag), skb_frag_off(frag));
297 		sk_mem_charge(sk, skb_frag_size(frag));
298 		get_page(skb_frag_page(frag));
299 	}
300 	sg_mark_end(&offload_ctx->sg_tx_data[record->num_frags - 1]);
301 
302 	/* all ready, send */
303 	return tls_push_sg(sk, ctx, offload_ctx->sg_tx_data, 0, flags);
304 }
305 
306 static int tls_device_record_close(struct sock *sk,
307 				   struct tls_context *ctx,
308 				   struct tls_record_info *record,
309 				   struct page_frag *pfrag,
310 				   unsigned char record_type)
311 {
312 	struct tls_prot_info *prot = &ctx->prot_info;
313 	int ret;
314 
315 	/* append tag
316 	 * device will fill in the tag, we just need to append a placeholder
317 	 * use socket memory to improve coalescing (re-using a single buffer
318 	 * increases frag count)
319 	 * if we can't allocate memory now, steal some back from data
320 	 */
321 	if (likely(skb_page_frag_refill(prot->tag_size, pfrag,
322 					sk->sk_allocation))) {
323 		ret = 0;
324 		tls_append_frag(record, pfrag, prot->tag_size);
325 	} else {
326 		ret = prot->tag_size;
327 		if (record->len <= prot->overhead_size)
328 			return -ENOMEM;
329 	}
330 
331 	/* fill prepend */
332 	tls_fill_prepend(ctx, skb_frag_address(&record->frags[0]),
333 			 record->len - prot->overhead_size,
334 			 record_type);
335 	return ret;
336 }
337 
338 static int tls_create_new_record(struct tls_offload_context_tx *offload_ctx,
339 				 struct page_frag *pfrag,
340 				 size_t prepend_size)
341 {
342 	struct tls_record_info *record;
343 	skb_frag_t *frag;
344 
345 	record = kmalloc(sizeof(*record), GFP_KERNEL);
346 	if (!record)
347 		return -ENOMEM;
348 
349 	frag = &record->frags[0];
350 	__skb_frag_set_page(frag, pfrag->page);
351 	skb_frag_off_set(frag, pfrag->offset);
352 	skb_frag_size_set(frag, prepend_size);
353 
354 	get_page(pfrag->page);
355 	pfrag->offset += prepend_size;
356 
357 	record->num_frags = 1;
358 	record->len = prepend_size;
359 	offload_ctx->open_record = record;
360 	return 0;
361 }
362 
363 static int tls_do_allocation(struct sock *sk,
364 			     struct tls_offload_context_tx *offload_ctx,
365 			     struct page_frag *pfrag,
366 			     size_t prepend_size)
367 {
368 	int ret;
369 
370 	if (!offload_ctx->open_record) {
371 		if (unlikely(!skb_page_frag_refill(prepend_size, pfrag,
372 						   sk->sk_allocation))) {
373 			READ_ONCE(sk->sk_prot)->enter_memory_pressure(sk);
374 			sk_stream_moderate_sndbuf(sk);
375 			return -ENOMEM;
376 		}
377 
378 		ret = tls_create_new_record(offload_ctx, pfrag, prepend_size);
379 		if (ret)
380 			return ret;
381 
382 		if (pfrag->size > pfrag->offset)
383 			return 0;
384 	}
385 
386 	if (!sk_page_frag_refill(sk, pfrag))
387 		return -ENOMEM;
388 
389 	return 0;
390 }
391 
392 static int tls_device_copy_data(void *addr, size_t bytes, struct iov_iter *i)
393 {
394 	size_t pre_copy, nocache;
395 
396 	pre_copy = ~((unsigned long)addr - 1) & (SMP_CACHE_BYTES - 1);
397 	if (pre_copy) {
398 		pre_copy = min(pre_copy, bytes);
399 		if (copy_from_iter(addr, pre_copy, i) != pre_copy)
400 			return -EFAULT;
401 		bytes -= pre_copy;
402 		addr += pre_copy;
403 	}
404 
405 	nocache = round_down(bytes, SMP_CACHE_BYTES);
406 	if (copy_from_iter_nocache(addr, nocache, i) != nocache)
407 		return -EFAULT;
408 	bytes -= nocache;
409 	addr += nocache;
410 
411 	if (bytes && copy_from_iter(addr, bytes, i) != bytes)
412 		return -EFAULT;
413 
414 	return 0;
415 }
416 
417 union tls_iter_offset {
418 	struct iov_iter *msg_iter;
419 	int offset;
420 };
421 
422 static int tls_push_data(struct sock *sk,
423 			 union tls_iter_offset iter_offset,
424 			 size_t size, int flags,
425 			 unsigned char record_type,
426 			 struct page *zc_page)
427 {
428 	struct tls_context *tls_ctx = tls_get_ctx(sk);
429 	struct tls_prot_info *prot = &tls_ctx->prot_info;
430 	struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
431 	struct tls_record_info *record;
432 	int tls_push_record_flags;
433 	struct page_frag *pfrag;
434 	size_t orig_size = size;
435 	u32 max_open_record_len;
436 	bool more = false;
437 	bool done = false;
438 	int copy, rc = 0;
439 	long timeo;
440 
441 	if (flags &
442 	    ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL | MSG_SENDPAGE_NOTLAST))
443 		return -EOPNOTSUPP;
444 
445 	if (unlikely(sk->sk_err))
446 		return -sk->sk_err;
447 
448 	flags |= MSG_SENDPAGE_DECRYPTED;
449 	tls_push_record_flags = flags | MSG_SENDPAGE_NOTLAST;
450 
451 	timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
452 	if (tls_is_partially_sent_record(tls_ctx)) {
453 		rc = tls_push_partial_record(sk, tls_ctx, flags);
454 		if (rc < 0)
455 			return rc;
456 	}
457 
458 	pfrag = sk_page_frag(sk);
459 
460 	/* TLS_HEADER_SIZE is not counted as part of the TLS record, and
461 	 * we need to leave room for an authentication tag.
462 	 */
463 	max_open_record_len = TLS_MAX_PAYLOAD_SIZE +
464 			      prot->prepend_size;
465 	do {
466 		rc = tls_do_allocation(sk, ctx, pfrag, prot->prepend_size);
467 		if (unlikely(rc)) {
468 			rc = sk_stream_wait_memory(sk, &timeo);
469 			if (!rc)
470 				continue;
471 
472 			record = ctx->open_record;
473 			if (!record)
474 				break;
475 handle_error:
476 			if (record_type != TLS_RECORD_TYPE_DATA) {
477 				/* avoid sending partial
478 				 * record with type !=
479 				 * application_data
480 				 */
481 				size = orig_size;
482 				destroy_record(record);
483 				ctx->open_record = NULL;
484 			} else if (record->len > prot->prepend_size) {
485 				goto last_record;
486 			}
487 
488 			break;
489 		}
490 
491 		record = ctx->open_record;
492 
493 		copy = min_t(size_t, size, max_open_record_len - record->len);
494 		if (copy && zc_page) {
495 			struct page_frag zc_pfrag;
496 
497 			zc_pfrag.page = zc_page;
498 			zc_pfrag.offset = iter_offset.offset;
499 			zc_pfrag.size = copy;
500 			tls_append_frag(record, &zc_pfrag, copy);
501 		} else if (copy) {
502 			copy = min_t(size_t, copy, pfrag->size - pfrag->offset);
503 
504 			rc = tls_device_copy_data(page_address(pfrag->page) +
505 						  pfrag->offset, copy,
506 						  iter_offset.msg_iter);
507 			if (rc)
508 				goto handle_error;
509 			tls_append_frag(record, pfrag, copy);
510 		}
511 
512 		size -= copy;
513 		if (!size) {
514 last_record:
515 			tls_push_record_flags = flags;
516 			if (flags & (MSG_SENDPAGE_NOTLAST | MSG_MORE)) {
517 				more = true;
518 				break;
519 			}
520 
521 			done = true;
522 		}
523 
524 		if (done || record->len >= max_open_record_len ||
525 		    (record->num_frags >= MAX_SKB_FRAGS - 1)) {
526 			rc = tls_device_record_close(sk, tls_ctx, record,
527 						     pfrag, record_type);
528 			if (rc) {
529 				if (rc > 0) {
530 					size += rc;
531 				} else {
532 					size = orig_size;
533 					destroy_record(record);
534 					ctx->open_record = NULL;
535 					break;
536 				}
537 			}
538 
539 			rc = tls_push_record(sk,
540 					     tls_ctx,
541 					     ctx,
542 					     record,
543 					     tls_push_record_flags);
544 			if (rc < 0)
545 				break;
546 		}
547 	} while (!done);
548 
549 	tls_ctx->pending_open_record_frags = more;
550 
551 	if (orig_size - size > 0)
552 		rc = orig_size - size;
553 
554 	return rc;
555 }
556 
557 int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
558 {
559 	unsigned char record_type = TLS_RECORD_TYPE_DATA;
560 	struct tls_context *tls_ctx = tls_get_ctx(sk);
561 	union tls_iter_offset iter;
562 	int rc;
563 
564 	mutex_lock(&tls_ctx->tx_lock);
565 	lock_sock(sk);
566 
567 	if (unlikely(msg->msg_controllen)) {
568 		rc = tls_process_cmsg(sk, msg, &record_type);
569 		if (rc)
570 			goto out;
571 	}
572 
573 	iter.msg_iter = &msg->msg_iter;
574 	rc = tls_push_data(sk, iter, size, msg->msg_flags, record_type, NULL);
575 
576 out:
577 	release_sock(sk);
578 	mutex_unlock(&tls_ctx->tx_lock);
579 	return rc;
580 }
581 
582 int tls_device_sendpage(struct sock *sk, struct page *page,
583 			int offset, size_t size, int flags)
584 {
585 	struct tls_context *tls_ctx = tls_get_ctx(sk);
586 	union tls_iter_offset iter_offset;
587 	struct iov_iter msg_iter;
588 	char *kaddr;
589 	struct kvec iov;
590 	int rc;
591 
592 	if (flags & MSG_SENDPAGE_NOTLAST)
593 		flags |= MSG_MORE;
594 
595 	mutex_lock(&tls_ctx->tx_lock);
596 	lock_sock(sk);
597 
598 	if (flags & MSG_OOB) {
599 		rc = -EOPNOTSUPP;
600 		goto out;
601 	}
602 
603 	if (tls_ctx->zerocopy_sendfile) {
604 		iter_offset.offset = offset;
605 		rc = tls_push_data(sk, iter_offset, size,
606 				   flags, TLS_RECORD_TYPE_DATA, page);
607 		goto out;
608 	}
609 
610 	kaddr = kmap(page);
611 	iov.iov_base = kaddr + offset;
612 	iov.iov_len = size;
613 	iov_iter_kvec(&msg_iter, WRITE, &iov, 1, size);
614 	iter_offset.msg_iter = &msg_iter;
615 	rc = tls_push_data(sk, iter_offset, size, flags, TLS_RECORD_TYPE_DATA,
616 			   NULL);
617 	kunmap(page);
618 
619 out:
620 	release_sock(sk);
621 	mutex_unlock(&tls_ctx->tx_lock);
622 	return rc;
623 }
624 
625 struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context,
626 				       u32 seq, u64 *p_record_sn)
627 {
628 	u64 record_sn = context->hint_record_sn;
629 	struct tls_record_info *info, *last;
630 
631 	info = context->retransmit_hint;
632 	if (!info ||
633 	    before(seq, info->end_seq - info->len)) {
634 		/* if retransmit_hint is irrelevant start
635 		 * from the beginning of the list
636 		 */
637 		info = list_first_entry_or_null(&context->records_list,
638 						struct tls_record_info, list);
639 		if (!info)
640 			return NULL;
641 		/* send the start_marker record if seq number is before the
642 		 * tls offload start marker sequence number. This record is
643 		 * required to handle TCP packets which are before TLS offload
644 		 * started.
645 		 *  And if it's not start marker, look if this seq number
646 		 * belongs to the list.
647 		 */
648 		if (likely(!tls_record_is_start_marker(info))) {
649 			/* we have the first record, get the last record to see
650 			 * if this seq number belongs to the list.
651 			 */
652 			last = list_last_entry(&context->records_list,
653 					       struct tls_record_info, list);
654 
655 			if (!between(seq, tls_record_start_seq(info),
656 				     last->end_seq))
657 				return NULL;
658 		}
659 		record_sn = context->unacked_record_sn;
660 	}
661 
662 	/* We just need the _rcu for the READ_ONCE() */
663 	rcu_read_lock();
664 	list_for_each_entry_from_rcu(info, &context->records_list, list) {
665 		if (before(seq, info->end_seq)) {
666 			if (!context->retransmit_hint ||
667 			    after(info->end_seq,
668 				  context->retransmit_hint->end_seq)) {
669 				context->hint_record_sn = record_sn;
670 				context->retransmit_hint = info;
671 			}
672 			*p_record_sn = record_sn;
673 			goto exit_rcu_unlock;
674 		}
675 		record_sn++;
676 	}
677 	info = NULL;
678 
679 exit_rcu_unlock:
680 	rcu_read_unlock();
681 	return info;
682 }
683 EXPORT_SYMBOL(tls_get_record);
684 
685 static int tls_device_push_pending_record(struct sock *sk, int flags)
686 {
687 	union tls_iter_offset iter;
688 	struct iov_iter msg_iter;
689 
690 	iov_iter_kvec(&msg_iter, WRITE, NULL, 0, 0);
691 	iter.msg_iter = &msg_iter;
692 	return tls_push_data(sk, iter, 0, flags, TLS_RECORD_TYPE_DATA, NULL);
693 }
694 
695 void tls_device_write_space(struct sock *sk, struct tls_context *ctx)
696 {
697 	if (tls_is_partially_sent_record(ctx)) {
698 		gfp_t sk_allocation = sk->sk_allocation;
699 
700 		WARN_ON_ONCE(sk->sk_write_pending);
701 
702 		sk->sk_allocation = GFP_ATOMIC;
703 		tls_push_partial_record(sk, ctx,
704 					MSG_DONTWAIT | MSG_NOSIGNAL |
705 					MSG_SENDPAGE_DECRYPTED);
706 		sk->sk_allocation = sk_allocation;
707 	}
708 }
709 
710 static void tls_device_resync_rx(struct tls_context *tls_ctx,
711 				 struct sock *sk, u32 seq, u8 *rcd_sn)
712 {
713 	struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
714 	struct net_device *netdev;
715 
716 	trace_tls_device_rx_resync_send(sk, seq, rcd_sn, rx_ctx->resync_type);
717 	rcu_read_lock();
718 	netdev = READ_ONCE(tls_ctx->netdev);
719 	if (netdev)
720 		netdev->tlsdev_ops->tls_dev_resync(netdev, sk, seq, rcd_sn,
721 						   TLS_OFFLOAD_CTX_DIR_RX);
722 	rcu_read_unlock();
723 	TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSRXDEVICERESYNC);
724 }
725 
726 static bool
727 tls_device_rx_resync_async(struct tls_offload_resync_async *resync_async,
728 			   s64 resync_req, u32 *seq, u16 *rcd_delta)
729 {
730 	u32 is_async = resync_req & RESYNC_REQ_ASYNC;
731 	u32 req_seq = resync_req >> 32;
732 	u32 req_end = req_seq + ((resync_req >> 16) & 0xffff);
733 	u16 i;
734 
735 	*rcd_delta = 0;
736 
737 	if (is_async) {
738 		/* shouldn't get to wraparound:
739 		 * too long in async stage, something bad happened
740 		 */
741 		if (WARN_ON_ONCE(resync_async->rcd_delta == USHRT_MAX))
742 			return false;
743 
744 		/* asynchronous stage: log all headers seq such that
745 		 * req_seq <= seq <= end_seq, and wait for real resync request
746 		 */
747 		if (before(*seq, req_seq))
748 			return false;
749 		if (!after(*seq, req_end) &&
750 		    resync_async->loglen < TLS_DEVICE_RESYNC_ASYNC_LOGMAX)
751 			resync_async->log[resync_async->loglen++] = *seq;
752 
753 		resync_async->rcd_delta++;
754 
755 		return false;
756 	}
757 
758 	/* synchronous stage: check against the logged entries and
759 	 * proceed to check the next entries if no match was found
760 	 */
761 	for (i = 0; i < resync_async->loglen; i++)
762 		if (req_seq == resync_async->log[i] &&
763 		    atomic64_try_cmpxchg(&resync_async->req, &resync_req, 0)) {
764 			*rcd_delta = resync_async->rcd_delta - i;
765 			*seq = req_seq;
766 			resync_async->loglen = 0;
767 			resync_async->rcd_delta = 0;
768 			return true;
769 		}
770 
771 	resync_async->loglen = 0;
772 	resync_async->rcd_delta = 0;
773 
774 	if (req_seq == *seq &&
775 	    atomic64_try_cmpxchg(&resync_async->req,
776 				 &resync_req, 0))
777 		return true;
778 
779 	return false;
780 }
781 
782 void tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq)
783 {
784 	struct tls_context *tls_ctx = tls_get_ctx(sk);
785 	struct tls_offload_context_rx *rx_ctx;
786 	u8 rcd_sn[TLS_MAX_REC_SEQ_SIZE];
787 	u32 sock_data, is_req_pending;
788 	struct tls_prot_info *prot;
789 	s64 resync_req;
790 	u16 rcd_delta;
791 	u32 req_seq;
792 
793 	if (tls_ctx->rx_conf != TLS_HW)
794 		return;
795 	if (unlikely(test_bit(TLS_RX_DEV_DEGRADED, &tls_ctx->flags)))
796 		return;
797 
798 	prot = &tls_ctx->prot_info;
799 	rx_ctx = tls_offload_ctx_rx(tls_ctx);
800 	memcpy(rcd_sn, tls_ctx->rx.rec_seq, prot->rec_seq_size);
801 
802 	switch (rx_ctx->resync_type) {
803 	case TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ:
804 		resync_req = atomic64_read(&rx_ctx->resync_req);
805 		req_seq = resync_req >> 32;
806 		seq += TLS_HEADER_SIZE - 1;
807 		is_req_pending = resync_req;
808 
809 		if (likely(!is_req_pending) || req_seq != seq ||
810 		    !atomic64_try_cmpxchg(&rx_ctx->resync_req, &resync_req, 0))
811 			return;
812 		break;
813 	case TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT:
814 		if (likely(!rx_ctx->resync_nh_do_now))
815 			return;
816 
817 		/* head of next rec is already in, note that the sock_inq will
818 		 * include the currently parsed message when called from parser
819 		 */
820 		sock_data = tcp_inq(sk);
821 		if (sock_data > rcd_len) {
822 			trace_tls_device_rx_resync_nh_delay(sk, sock_data,
823 							    rcd_len);
824 			return;
825 		}
826 
827 		rx_ctx->resync_nh_do_now = 0;
828 		seq += rcd_len;
829 		tls_bigint_increment(rcd_sn, prot->rec_seq_size);
830 		break;
831 	case TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ_ASYNC:
832 		resync_req = atomic64_read(&rx_ctx->resync_async->req);
833 		is_req_pending = resync_req;
834 		if (likely(!is_req_pending))
835 			return;
836 
837 		if (!tls_device_rx_resync_async(rx_ctx->resync_async,
838 						resync_req, &seq, &rcd_delta))
839 			return;
840 		tls_bigint_subtract(rcd_sn, rcd_delta);
841 		break;
842 	}
843 
844 	tls_device_resync_rx(tls_ctx, sk, seq, rcd_sn);
845 }
846 
847 static void tls_device_core_ctrl_rx_resync(struct tls_context *tls_ctx,
848 					   struct tls_offload_context_rx *ctx,
849 					   struct sock *sk, struct sk_buff *skb)
850 {
851 	struct strp_msg *rxm;
852 
853 	/* device will request resyncs by itself based on stream scan */
854 	if (ctx->resync_type != TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT)
855 		return;
856 	/* already scheduled */
857 	if (ctx->resync_nh_do_now)
858 		return;
859 	/* seen decrypted fragments since last fully-failed record */
860 	if (ctx->resync_nh_reset) {
861 		ctx->resync_nh_reset = 0;
862 		ctx->resync_nh.decrypted_failed = 1;
863 		ctx->resync_nh.decrypted_tgt = TLS_DEVICE_RESYNC_NH_START_IVAL;
864 		return;
865 	}
866 
867 	if (++ctx->resync_nh.decrypted_failed <= ctx->resync_nh.decrypted_tgt)
868 		return;
869 
870 	/* doing resync, bump the next target in case it fails */
871 	if (ctx->resync_nh.decrypted_tgt < TLS_DEVICE_RESYNC_NH_MAX_IVAL)
872 		ctx->resync_nh.decrypted_tgt *= 2;
873 	else
874 		ctx->resync_nh.decrypted_tgt += TLS_DEVICE_RESYNC_NH_MAX_IVAL;
875 
876 	rxm = strp_msg(skb);
877 
878 	/* head of next rec is already in, parser will sync for us */
879 	if (tcp_inq(sk) > rxm->full_len) {
880 		trace_tls_device_rx_resync_nh_schedule(sk);
881 		ctx->resync_nh_do_now = 1;
882 	} else {
883 		struct tls_prot_info *prot = &tls_ctx->prot_info;
884 		u8 rcd_sn[TLS_MAX_REC_SEQ_SIZE];
885 
886 		memcpy(rcd_sn, tls_ctx->rx.rec_seq, prot->rec_seq_size);
887 		tls_bigint_increment(rcd_sn, prot->rec_seq_size);
888 
889 		tls_device_resync_rx(tls_ctx, sk, tcp_sk(sk)->copied_seq,
890 				     rcd_sn);
891 	}
892 }
893 
894 static int
895 tls_device_reencrypt(struct sock *sk, struct tls_sw_context_rx *sw_ctx)
896 {
897 	int err = 0, offset, copy, nsg, data_len, pos;
898 	struct sk_buff *skb, *skb_iter, *unused;
899 	struct scatterlist sg[1];
900 	struct strp_msg *rxm;
901 	char *orig_buf, *buf;
902 
903 	skb = tls_strp_msg(sw_ctx);
904 	rxm = strp_msg(skb);
905 	offset = rxm->offset;
906 
907 	orig_buf = kmalloc(rxm->full_len + TLS_HEADER_SIZE +
908 			   TLS_CIPHER_AES_GCM_128_IV_SIZE, sk->sk_allocation);
909 	if (!orig_buf)
910 		return -ENOMEM;
911 	buf = orig_buf;
912 
913 	nsg = skb_cow_data(skb, 0, &unused);
914 	if (unlikely(nsg < 0)) {
915 		err = nsg;
916 		goto free_buf;
917 	}
918 
919 	sg_init_table(sg, 1);
920 	sg_set_buf(&sg[0], buf,
921 		   rxm->full_len + TLS_HEADER_SIZE +
922 		   TLS_CIPHER_AES_GCM_128_IV_SIZE);
923 	err = skb_copy_bits(skb, offset, buf,
924 			    TLS_HEADER_SIZE + TLS_CIPHER_AES_GCM_128_IV_SIZE);
925 	if (err)
926 		goto free_buf;
927 
928 	/* We are interested only in the decrypted data not the auth */
929 	err = decrypt_skb(sk, sg);
930 	if (err != -EBADMSG)
931 		goto free_buf;
932 	else
933 		err = 0;
934 
935 	data_len = rxm->full_len - TLS_CIPHER_AES_GCM_128_TAG_SIZE;
936 
937 	if (skb_pagelen(skb) > offset) {
938 		copy = min_t(int, skb_pagelen(skb) - offset, data_len);
939 
940 		if (skb->decrypted) {
941 			err = skb_store_bits(skb, offset, buf, copy);
942 			if (err)
943 				goto free_buf;
944 		}
945 
946 		offset += copy;
947 		buf += copy;
948 	}
949 
950 	pos = skb_pagelen(skb);
951 	skb_walk_frags(skb, skb_iter) {
952 		int frag_pos;
953 
954 		/* Practically all frags must belong to msg if reencrypt
955 		 * is needed with current strparser and coalescing logic,
956 		 * but strparser may "get optimized", so let's be safe.
957 		 */
958 		if (pos + skb_iter->len <= offset)
959 			goto done_with_frag;
960 		if (pos >= data_len + rxm->offset)
961 			break;
962 
963 		frag_pos = offset - pos;
964 		copy = min_t(int, skb_iter->len - frag_pos,
965 			     data_len + rxm->offset - offset);
966 
967 		if (skb_iter->decrypted) {
968 			err = skb_store_bits(skb_iter, frag_pos, buf, copy);
969 			if (err)
970 				goto free_buf;
971 		}
972 
973 		offset += copy;
974 		buf += copy;
975 done_with_frag:
976 		pos += skb_iter->len;
977 	}
978 
979 free_buf:
980 	kfree(orig_buf);
981 	return err;
982 }
983 
984 int tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx)
985 {
986 	struct tls_offload_context_rx *ctx = tls_offload_ctx_rx(tls_ctx);
987 	struct tls_sw_context_rx *sw_ctx = tls_sw_ctx_rx(tls_ctx);
988 	struct sk_buff *skb = tls_strp_msg(sw_ctx);
989 	struct strp_msg *rxm = strp_msg(skb);
990 	int is_decrypted = skb->decrypted;
991 	int is_encrypted = !is_decrypted;
992 	struct sk_buff *skb_iter;
993 
994 	/* Check if all the data is decrypted already */
995 	skb_walk_frags(skb, skb_iter) {
996 		is_decrypted &= skb_iter->decrypted;
997 		is_encrypted &= !skb_iter->decrypted;
998 	}
999 
1000 	trace_tls_device_decrypted(sk, tcp_sk(sk)->copied_seq - rxm->full_len,
1001 				   tls_ctx->rx.rec_seq, rxm->full_len,
1002 				   is_encrypted, is_decrypted);
1003 
1004 	if (unlikely(test_bit(TLS_RX_DEV_DEGRADED, &tls_ctx->flags))) {
1005 		if (likely(is_encrypted || is_decrypted))
1006 			return is_decrypted;
1007 
1008 		/* After tls_device_down disables the offload, the next SKB will
1009 		 * likely have initial fragments decrypted, and final ones not
1010 		 * decrypted. We need to reencrypt that single SKB.
1011 		 */
1012 		return tls_device_reencrypt(sk, sw_ctx);
1013 	}
1014 
1015 	/* Return immediately if the record is either entirely plaintext or
1016 	 * entirely ciphertext. Otherwise handle reencrypt partially decrypted
1017 	 * record.
1018 	 */
1019 	if (is_decrypted) {
1020 		ctx->resync_nh_reset = 1;
1021 		return is_decrypted;
1022 	}
1023 	if (is_encrypted) {
1024 		tls_device_core_ctrl_rx_resync(tls_ctx, ctx, sk, skb);
1025 		return 0;
1026 	}
1027 
1028 	ctx->resync_nh_reset = 1;
1029 	return tls_device_reencrypt(sk, sw_ctx);
1030 }
1031 
1032 static void tls_device_attach(struct tls_context *ctx, struct sock *sk,
1033 			      struct net_device *netdev)
1034 {
1035 	if (sk->sk_destruct != tls_device_sk_destruct) {
1036 		refcount_set(&ctx->refcount, 1);
1037 		dev_hold(netdev);
1038 		ctx->netdev = netdev;
1039 		spin_lock_irq(&tls_device_lock);
1040 		list_add_tail(&ctx->list, &tls_device_list);
1041 		spin_unlock_irq(&tls_device_lock);
1042 
1043 		ctx->sk_destruct = sk->sk_destruct;
1044 		smp_store_release(&sk->sk_destruct, tls_device_sk_destruct);
1045 	}
1046 }
1047 
1048 int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
1049 {
1050 	u16 nonce_size, tag_size, iv_size, rec_seq_size, salt_size;
1051 	struct tls_context *tls_ctx = tls_get_ctx(sk);
1052 	struct tls_prot_info *prot = &tls_ctx->prot_info;
1053 	struct tls_record_info *start_marker_record;
1054 	struct tls_offload_context_tx *offload_ctx;
1055 	struct tls_crypto_info *crypto_info;
1056 	struct net_device *netdev;
1057 	char *iv, *rec_seq;
1058 	struct sk_buff *skb;
1059 	__be64 rcd_sn;
1060 	int rc;
1061 
1062 	if (!ctx)
1063 		return -EINVAL;
1064 
1065 	if (ctx->priv_ctx_tx)
1066 		return -EEXIST;
1067 
1068 	netdev = get_netdev_for_sock(sk);
1069 	if (!netdev) {
1070 		pr_err_ratelimited("%s: netdev not found\n", __func__);
1071 		return -EINVAL;
1072 	}
1073 
1074 	if (!(netdev->features & NETIF_F_HW_TLS_TX)) {
1075 		rc = -EOPNOTSUPP;
1076 		goto release_netdev;
1077 	}
1078 
1079 	crypto_info = &ctx->crypto_send.info;
1080 	if (crypto_info->version != TLS_1_2_VERSION) {
1081 		rc = -EOPNOTSUPP;
1082 		goto release_netdev;
1083 	}
1084 
1085 	switch (crypto_info->cipher_type) {
1086 	case TLS_CIPHER_AES_GCM_128:
1087 		nonce_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
1088 		tag_size = TLS_CIPHER_AES_GCM_128_TAG_SIZE;
1089 		iv_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
1090 		iv = ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->iv;
1091 		rec_seq_size = TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE;
1092 		salt_size = TLS_CIPHER_AES_GCM_128_SALT_SIZE;
1093 		rec_seq =
1094 		 ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->rec_seq;
1095 		break;
1096 	default:
1097 		rc = -EINVAL;
1098 		goto release_netdev;
1099 	}
1100 
1101 	/* Sanity-check the rec_seq_size for stack allocations */
1102 	if (rec_seq_size > TLS_MAX_REC_SEQ_SIZE) {
1103 		rc = -EINVAL;
1104 		goto release_netdev;
1105 	}
1106 
1107 	prot->version = crypto_info->version;
1108 	prot->cipher_type = crypto_info->cipher_type;
1109 	prot->prepend_size = TLS_HEADER_SIZE + nonce_size;
1110 	prot->tag_size = tag_size;
1111 	prot->overhead_size = prot->prepend_size + prot->tag_size;
1112 	prot->iv_size = iv_size;
1113 	prot->salt_size = salt_size;
1114 	ctx->tx.iv = kmalloc(iv_size + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
1115 			     GFP_KERNEL);
1116 	if (!ctx->tx.iv) {
1117 		rc = -ENOMEM;
1118 		goto release_netdev;
1119 	}
1120 
1121 	memcpy(ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv, iv_size);
1122 
1123 	prot->rec_seq_size = rec_seq_size;
1124 	ctx->tx.rec_seq = kmemdup(rec_seq, rec_seq_size, GFP_KERNEL);
1125 	if (!ctx->tx.rec_seq) {
1126 		rc = -ENOMEM;
1127 		goto free_iv;
1128 	}
1129 
1130 	start_marker_record = kmalloc(sizeof(*start_marker_record), GFP_KERNEL);
1131 	if (!start_marker_record) {
1132 		rc = -ENOMEM;
1133 		goto free_rec_seq;
1134 	}
1135 
1136 	offload_ctx = kzalloc(TLS_OFFLOAD_CONTEXT_SIZE_TX, GFP_KERNEL);
1137 	if (!offload_ctx) {
1138 		rc = -ENOMEM;
1139 		goto free_marker_record;
1140 	}
1141 
1142 	rc = tls_sw_fallback_init(sk, offload_ctx, crypto_info);
1143 	if (rc)
1144 		goto free_offload_ctx;
1145 
1146 	/* start at rec_seq - 1 to account for the start marker record */
1147 	memcpy(&rcd_sn, ctx->tx.rec_seq, sizeof(rcd_sn));
1148 	offload_ctx->unacked_record_sn = be64_to_cpu(rcd_sn) - 1;
1149 
1150 	start_marker_record->end_seq = tcp_sk(sk)->write_seq;
1151 	start_marker_record->len = 0;
1152 	start_marker_record->num_frags = 0;
1153 
1154 	INIT_LIST_HEAD(&offload_ctx->records_list);
1155 	list_add_tail(&start_marker_record->list, &offload_ctx->records_list);
1156 	spin_lock_init(&offload_ctx->lock);
1157 	sg_init_table(offload_ctx->sg_tx_data,
1158 		      ARRAY_SIZE(offload_ctx->sg_tx_data));
1159 
1160 	clean_acked_data_enable(inet_csk(sk), &tls_icsk_clean_acked);
1161 	ctx->push_pending_record = tls_device_push_pending_record;
1162 
1163 	/* TLS offload is greatly simplified if we don't send
1164 	 * SKBs where only part of the payload needs to be encrypted.
1165 	 * So mark the last skb in the write queue as end of record.
1166 	 */
1167 	skb = tcp_write_queue_tail(sk);
1168 	if (skb)
1169 		TCP_SKB_CB(skb)->eor = 1;
1170 
1171 	/* Avoid offloading if the device is down
1172 	 * We don't want to offload new flows after
1173 	 * the NETDEV_DOWN event
1174 	 *
1175 	 * device_offload_lock is taken in tls_devices's NETDEV_DOWN
1176 	 * handler thus protecting from the device going down before
1177 	 * ctx was added to tls_device_list.
1178 	 */
1179 	down_read(&device_offload_lock);
1180 	if (!(netdev->flags & IFF_UP)) {
1181 		rc = -EINVAL;
1182 		goto release_lock;
1183 	}
1184 
1185 	ctx->priv_ctx_tx = offload_ctx;
1186 	rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_TX,
1187 					     &ctx->crypto_send.info,
1188 					     tcp_sk(sk)->write_seq);
1189 	trace_tls_device_offload_set(sk, TLS_OFFLOAD_CTX_DIR_TX,
1190 				     tcp_sk(sk)->write_seq, rec_seq, rc);
1191 	if (rc)
1192 		goto release_lock;
1193 
1194 	tls_device_attach(ctx, sk, netdev);
1195 	up_read(&device_offload_lock);
1196 
1197 	/* following this assignment tls_is_sk_tx_device_offloaded
1198 	 * will return true and the context might be accessed
1199 	 * by the netdev's xmit function.
1200 	 */
1201 	smp_store_release(&sk->sk_validate_xmit_skb, tls_validate_xmit_skb);
1202 	dev_put(netdev);
1203 
1204 	return 0;
1205 
1206 release_lock:
1207 	up_read(&device_offload_lock);
1208 	clean_acked_data_disable(inet_csk(sk));
1209 	crypto_free_aead(offload_ctx->aead_send);
1210 free_offload_ctx:
1211 	kfree(offload_ctx);
1212 	ctx->priv_ctx_tx = NULL;
1213 free_marker_record:
1214 	kfree(start_marker_record);
1215 free_rec_seq:
1216 	kfree(ctx->tx.rec_seq);
1217 free_iv:
1218 	kfree(ctx->tx.iv);
1219 release_netdev:
1220 	dev_put(netdev);
1221 	return rc;
1222 }
1223 
1224 int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
1225 {
1226 	struct tls12_crypto_info_aes_gcm_128 *info;
1227 	struct tls_offload_context_rx *context;
1228 	struct net_device *netdev;
1229 	int rc = 0;
1230 
1231 	if (ctx->crypto_recv.info.version != TLS_1_2_VERSION)
1232 		return -EOPNOTSUPP;
1233 
1234 	netdev = get_netdev_for_sock(sk);
1235 	if (!netdev) {
1236 		pr_err_ratelimited("%s: netdev not found\n", __func__);
1237 		return -EINVAL;
1238 	}
1239 
1240 	if (!(netdev->features & NETIF_F_HW_TLS_RX)) {
1241 		rc = -EOPNOTSUPP;
1242 		goto release_netdev;
1243 	}
1244 
1245 	/* Avoid offloading if the device is down
1246 	 * We don't want to offload new flows after
1247 	 * the NETDEV_DOWN event
1248 	 *
1249 	 * device_offload_lock is taken in tls_devices's NETDEV_DOWN
1250 	 * handler thus protecting from the device going down before
1251 	 * ctx was added to tls_device_list.
1252 	 */
1253 	down_read(&device_offload_lock);
1254 	if (!(netdev->flags & IFF_UP)) {
1255 		rc = -EINVAL;
1256 		goto release_lock;
1257 	}
1258 
1259 	context = kzalloc(TLS_OFFLOAD_CONTEXT_SIZE_RX, GFP_KERNEL);
1260 	if (!context) {
1261 		rc = -ENOMEM;
1262 		goto release_lock;
1263 	}
1264 	context->resync_nh_reset = 1;
1265 
1266 	ctx->priv_ctx_rx = context;
1267 	rc = tls_set_sw_offload(sk, ctx, 0);
1268 	if (rc)
1269 		goto release_ctx;
1270 
1271 	rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_RX,
1272 					     &ctx->crypto_recv.info,
1273 					     tcp_sk(sk)->copied_seq);
1274 	info = (void *)&ctx->crypto_recv.info;
1275 	trace_tls_device_offload_set(sk, TLS_OFFLOAD_CTX_DIR_RX,
1276 				     tcp_sk(sk)->copied_seq, info->rec_seq, rc);
1277 	if (rc)
1278 		goto free_sw_resources;
1279 
1280 	tls_device_attach(ctx, sk, netdev);
1281 	up_read(&device_offload_lock);
1282 
1283 	dev_put(netdev);
1284 
1285 	return 0;
1286 
1287 free_sw_resources:
1288 	up_read(&device_offload_lock);
1289 	tls_sw_free_resources_rx(sk);
1290 	down_read(&device_offload_lock);
1291 release_ctx:
1292 	ctx->priv_ctx_rx = NULL;
1293 release_lock:
1294 	up_read(&device_offload_lock);
1295 release_netdev:
1296 	dev_put(netdev);
1297 	return rc;
1298 }
1299 
1300 void tls_device_offload_cleanup_rx(struct sock *sk)
1301 {
1302 	struct tls_context *tls_ctx = tls_get_ctx(sk);
1303 	struct net_device *netdev;
1304 
1305 	down_read(&device_offload_lock);
1306 	netdev = tls_ctx->netdev;
1307 	if (!netdev)
1308 		goto out;
1309 
1310 	netdev->tlsdev_ops->tls_dev_del(netdev, tls_ctx,
1311 					TLS_OFFLOAD_CTX_DIR_RX);
1312 
1313 	if (tls_ctx->tx_conf != TLS_HW) {
1314 		dev_put(netdev);
1315 		tls_ctx->netdev = NULL;
1316 	} else {
1317 		set_bit(TLS_RX_DEV_CLOSED, &tls_ctx->flags);
1318 	}
1319 out:
1320 	up_read(&device_offload_lock);
1321 	tls_sw_release_resources_rx(sk);
1322 }
1323 
1324 static int tls_device_down(struct net_device *netdev)
1325 {
1326 	struct tls_context *ctx, *tmp;
1327 	unsigned long flags;
1328 	LIST_HEAD(list);
1329 
1330 	/* Request a write lock to block new offload attempts */
1331 	down_write(&device_offload_lock);
1332 
1333 	spin_lock_irqsave(&tls_device_lock, flags);
1334 	list_for_each_entry_safe(ctx, tmp, &tls_device_list, list) {
1335 		if (ctx->netdev != netdev ||
1336 		    !refcount_inc_not_zero(&ctx->refcount))
1337 			continue;
1338 
1339 		list_move(&ctx->list, &list);
1340 	}
1341 	spin_unlock_irqrestore(&tls_device_lock, flags);
1342 
1343 	list_for_each_entry_safe(ctx, tmp, &list, list)	{
1344 		/* Stop offloaded TX and switch to the fallback.
1345 		 * tls_is_sk_tx_device_offloaded will return false.
1346 		 */
1347 		WRITE_ONCE(ctx->sk->sk_validate_xmit_skb, tls_validate_xmit_skb_sw);
1348 
1349 		/* Stop the RX and TX resync.
1350 		 * tls_dev_resync must not be called after tls_dev_del.
1351 		 */
1352 		WRITE_ONCE(ctx->netdev, NULL);
1353 
1354 		/* Start skipping the RX resync logic completely. */
1355 		set_bit(TLS_RX_DEV_DEGRADED, &ctx->flags);
1356 
1357 		/* Sync with inflight packets. After this point:
1358 		 * TX: no non-encrypted packets will be passed to the driver.
1359 		 * RX: resync requests from the driver will be ignored.
1360 		 */
1361 		synchronize_net();
1362 
1363 		/* Release the offload context on the driver side. */
1364 		if (ctx->tx_conf == TLS_HW)
1365 			netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
1366 							TLS_OFFLOAD_CTX_DIR_TX);
1367 		if (ctx->rx_conf == TLS_HW &&
1368 		    !test_bit(TLS_RX_DEV_CLOSED, &ctx->flags))
1369 			netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
1370 							TLS_OFFLOAD_CTX_DIR_RX);
1371 
1372 		dev_put(netdev);
1373 
1374 		/* Move the context to a separate list for two reasons:
1375 		 * 1. When the context is deallocated, list_del is called.
1376 		 * 2. It's no longer an offloaded context, so we don't want to
1377 		 *    run offload-specific code on this context.
1378 		 */
1379 		spin_lock_irqsave(&tls_device_lock, flags);
1380 		list_move_tail(&ctx->list, &tls_device_down_list);
1381 		spin_unlock_irqrestore(&tls_device_lock, flags);
1382 
1383 		/* Device contexts for RX and TX will be freed in on sk_destruct
1384 		 * by tls_device_free_ctx. rx_conf and tx_conf stay in TLS_HW.
1385 		 * Now release the ref taken above.
1386 		 */
1387 		if (refcount_dec_and_test(&ctx->refcount))
1388 			tls_device_free_ctx(ctx);
1389 	}
1390 
1391 	up_write(&device_offload_lock);
1392 
1393 	flush_work(&tls_device_gc_work);
1394 
1395 	return NOTIFY_DONE;
1396 }
1397 
1398 static int tls_dev_event(struct notifier_block *this, unsigned long event,
1399 			 void *ptr)
1400 {
1401 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1402 
1403 	if (!dev->tlsdev_ops &&
1404 	    !(dev->features & (NETIF_F_HW_TLS_RX | NETIF_F_HW_TLS_TX)))
1405 		return NOTIFY_DONE;
1406 
1407 	switch (event) {
1408 	case NETDEV_REGISTER:
1409 	case NETDEV_FEAT_CHANGE:
1410 		if (netif_is_bond_master(dev))
1411 			return NOTIFY_DONE;
1412 		if ((dev->features & NETIF_F_HW_TLS_RX) &&
1413 		    !dev->tlsdev_ops->tls_dev_resync)
1414 			return NOTIFY_BAD;
1415 
1416 		if  (dev->tlsdev_ops &&
1417 		     dev->tlsdev_ops->tls_dev_add &&
1418 		     dev->tlsdev_ops->tls_dev_del)
1419 			return NOTIFY_DONE;
1420 		else
1421 			return NOTIFY_BAD;
1422 	case NETDEV_DOWN:
1423 		return tls_device_down(dev);
1424 	}
1425 	return NOTIFY_DONE;
1426 }
1427 
1428 static struct notifier_block tls_dev_notifier = {
1429 	.notifier_call	= tls_dev_event,
1430 };
1431 
1432 int __init tls_device_init(void)
1433 {
1434 	return register_netdevice_notifier(&tls_dev_notifier);
1435 }
1436 
1437 void __exit tls_device_cleanup(void)
1438 {
1439 	unregister_netdevice_notifier(&tls_dev_notifier);
1440 	flush_work(&tls_device_gc_work);
1441 	clean_acked_data_flush();
1442 }
1443