xref: /linux/net/tls/tls_device.c (revision 2dc73b48665411a08c4e5f0f823dea8510761603)
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 struct workqueue_struct *destruct_wq __read_mostly;
50 
51 static LIST_HEAD(tls_device_list);
52 static LIST_HEAD(tls_device_down_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_tx_del_task(struct work_struct *work)
70 {
71 	struct tls_offload_context_tx *offload_ctx =
72 		container_of(work, struct tls_offload_context_tx, destruct_work);
73 	struct tls_context *ctx = offload_ctx->ctx;
74 	struct net_device *netdev;
75 
76 	/* Safe, because this is the destroy flow, refcount is 0, so
77 	 * tls_device_down can't store this field in parallel.
78 	 */
79 	netdev = rcu_dereference_protected(ctx->netdev,
80 					   !refcount_read(&ctx->refcount));
81 
82 	netdev->tlsdev_ops->tls_dev_del(netdev, ctx, TLS_OFFLOAD_CTX_DIR_TX);
83 	dev_put(netdev);
84 	ctx->netdev = NULL;
85 	tls_device_free_ctx(ctx);
86 }
87 
88 static void tls_device_queue_ctx_destruction(struct tls_context *ctx)
89 {
90 	struct net_device *netdev;
91 	unsigned long flags;
92 	bool async_cleanup;
93 
94 	spin_lock_irqsave(&tls_device_lock, flags);
95 	if (unlikely(!refcount_dec_and_test(&ctx->refcount))) {
96 		spin_unlock_irqrestore(&tls_device_lock, flags);
97 		return;
98 	}
99 
100 	list_del(&ctx->list); /* Remove from tls_device_list / tls_device_down_list */
101 
102 	/* Safe, because this is the destroy flow, refcount is 0, so
103 	 * tls_device_down can't store this field in parallel.
104 	 */
105 	netdev = rcu_dereference_protected(ctx->netdev,
106 					   !refcount_read(&ctx->refcount));
107 
108 	async_cleanup = netdev && ctx->tx_conf == TLS_HW;
109 	if (async_cleanup) {
110 		struct tls_offload_context_tx *offload_ctx = tls_offload_ctx_tx(ctx);
111 
112 		/* queue_work inside the spinlock
113 		 * to make sure tls_device_down waits for that work.
114 		 */
115 		queue_work(destruct_wq, &offload_ctx->destruct_work);
116 	}
117 	spin_unlock_irqrestore(&tls_device_lock, flags);
118 
119 	if (!async_cleanup)
120 		tls_device_free_ctx(ctx);
121 }
122 
123 /* We assume that the socket is already connected */
124 static struct net_device *get_netdev_for_sock(struct sock *sk)
125 {
126 	struct dst_entry *dst = sk_dst_get(sk);
127 	struct net_device *netdev = NULL;
128 
129 	if (likely(dst)) {
130 		netdev = netdev_sk_get_lowest_dev(dst->dev, sk);
131 		dev_hold(netdev);
132 	}
133 
134 	dst_release(dst);
135 
136 	return netdev;
137 }
138 
139 static void destroy_record(struct tls_record_info *record)
140 {
141 	int i;
142 
143 	for (i = 0; i < record->num_frags; i++)
144 		__skb_frag_unref(&record->frags[i], false);
145 	kfree(record);
146 }
147 
148 static void delete_all_records(struct tls_offload_context_tx *offload_ctx)
149 {
150 	struct tls_record_info *info, *temp;
151 
152 	list_for_each_entry_safe(info, temp, &offload_ctx->records_list, list) {
153 		list_del(&info->list);
154 		destroy_record(info);
155 	}
156 
157 	offload_ctx->retransmit_hint = NULL;
158 }
159 
160 static void tls_icsk_clean_acked(struct sock *sk, u32 acked_seq)
161 {
162 	struct tls_context *tls_ctx = tls_get_ctx(sk);
163 	struct tls_record_info *info, *temp;
164 	struct tls_offload_context_tx *ctx;
165 	u64 deleted_records = 0;
166 	unsigned long flags;
167 
168 	if (!tls_ctx)
169 		return;
170 
171 	ctx = tls_offload_ctx_tx(tls_ctx);
172 
173 	spin_lock_irqsave(&ctx->lock, flags);
174 	info = ctx->retransmit_hint;
175 	if (info && !before(acked_seq, info->end_seq))
176 		ctx->retransmit_hint = NULL;
177 
178 	list_for_each_entry_safe(info, temp, &ctx->records_list, list) {
179 		if (before(acked_seq, info->end_seq))
180 			break;
181 		list_del(&info->list);
182 
183 		destroy_record(info);
184 		deleted_records++;
185 	}
186 
187 	ctx->unacked_record_sn += deleted_records;
188 	spin_unlock_irqrestore(&ctx->lock, flags);
189 }
190 
191 /* At this point, there should be no references on this
192  * socket and no in-flight SKBs associated with this
193  * socket, so it is safe to free all the resources.
194  */
195 void tls_device_sk_destruct(struct sock *sk)
196 {
197 	struct tls_context *tls_ctx = tls_get_ctx(sk);
198 	struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
199 
200 	tls_ctx->sk_destruct(sk);
201 
202 	if (tls_ctx->tx_conf == TLS_HW) {
203 		if (ctx->open_record)
204 			destroy_record(ctx->open_record);
205 		delete_all_records(ctx);
206 		crypto_free_aead(ctx->aead_send);
207 		clean_acked_data_disable(inet_csk(sk));
208 	}
209 
210 	tls_device_queue_ctx_destruction(tls_ctx);
211 }
212 EXPORT_SYMBOL_GPL(tls_device_sk_destruct);
213 
214 void tls_device_free_resources_tx(struct sock *sk)
215 {
216 	struct tls_context *tls_ctx = tls_get_ctx(sk);
217 
218 	tls_free_partial_record(sk, tls_ctx);
219 }
220 
221 void tls_offload_tx_resync_request(struct sock *sk, u32 got_seq, u32 exp_seq)
222 {
223 	struct tls_context *tls_ctx = tls_get_ctx(sk);
224 
225 	trace_tls_device_tx_resync_req(sk, got_seq, exp_seq);
226 	WARN_ON(test_and_set_bit(TLS_TX_SYNC_SCHED, &tls_ctx->flags));
227 }
228 EXPORT_SYMBOL_GPL(tls_offload_tx_resync_request);
229 
230 static void tls_device_resync_tx(struct sock *sk, struct tls_context *tls_ctx,
231 				 u32 seq)
232 {
233 	struct net_device *netdev;
234 	struct sk_buff *skb;
235 	int err = 0;
236 	u8 *rcd_sn;
237 
238 	skb = tcp_write_queue_tail(sk);
239 	if (skb)
240 		TCP_SKB_CB(skb)->eor = 1;
241 
242 	rcd_sn = tls_ctx->tx.rec_seq;
243 
244 	trace_tls_device_tx_resync_send(sk, seq, rcd_sn);
245 	down_read(&device_offload_lock);
246 	netdev = rcu_dereference_protected(tls_ctx->netdev,
247 					   lockdep_is_held(&device_offload_lock));
248 	if (netdev)
249 		err = netdev->tlsdev_ops->tls_dev_resync(netdev, sk, seq,
250 							 rcd_sn,
251 							 TLS_OFFLOAD_CTX_DIR_TX);
252 	up_read(&device_offload_lock);
253 	if (err)
254 		return;
255 
256 	clear_bit_unlock(TLS_TX_SYNC_SCHED, &tls_ctx->flags);
257 }
258 
259 static void tls_append_frag(struct tls_record_info *record,
260 			    struct page_frag *pfrag,
261 			    int size)
262 {
263 	skb_frag_t *frag;
264 
265 	frag = &record->frags[record->num_frags - 1];
266 	if (skb_frag_page(frag) == pfrag->page &&
267 	    skb_frag_off(frag) + skb_frag_size(frag) == pfrag->offset) {
268 		skb_frag_size_add(frag, size);
269 	} else {
270 		++frag;
271 		__skb_frag_set_page(frag, pfrag->page);
272 		skb_frag_off_set(frag, pfrag->offset);
273 		skb_frag_size_set(frag, size);
274 		++record->num_frags;
275 		get_page(pfrag->page);
276 	}
277 
278 	pfrag->offset += size;
279 	record->len += size;
280 }
281 
282 static int tls_push_record(struct sock *sk,
283 			   struct tls_context *ctx,
284 			   struct tls_offload_context_tx *offload_ctx,
285 			   struct tls_record_info *record,
286 			   int flags)
287 {
288 	struct tls_prot_info *prot = &ctx->prot_info;
289 	struct tcp_sock *tp = tcp_sk(sk);
290 	skb_frag_t *frag;
291 	int i;
292 
293 	record->end_seq = tp->write_seq + record->len;
294 	list_add_tail_rcu(&record->list, &offload_ctx->records_list);
295 	offload_ctx->open_record = NULL;
296 
297 	if (test_bit(TLS_TX_SYNC_SCHED, &ctx->flags))
298 		tls_device_resync_tx(sk, ctx, tp->write_seq);
299 
300 	tls_advance_record_sn(sk, prot, &ctx->tx);
301 
302 	for (i = 0; i < record->num_frags; i++) {
303 		frag = &record->frags[i];
304 		sg_unmark_end(&offload_ctx->sg_tx_data[i]);
305 		sg_set_page(&offload_ctx->sg_tx_data[i], skb_frag_page(frag),
306 			    skb_frag_size(frag), skb_frag_off(frag));
307 		sk_mem_charge(sk, skb_frag_size(frag));
308 		get_page(skb_frag_page(frag));
309 	}
310 	sg_mark_end(&offload_ctx->sg_tx_data[record->num_frags - 1]);
311 
312 	/* all ready, send */
313 	return tls_push_sg(sk, ctx, offload_ctx->sg_tx_data, 0, flags);
314 }
315 
316 static int tls_device_record_close(struct sock *sk,
317 				   struct tls_context *ctx,
318 				   struct tls_record_info *record,
319 				   struct page_frag *pfrag,
320 				   unsigned char record_type)
321 {
322 	struct tls_prot_info *prot = &ctx->prot_info;
323 	int ret;
324 
325 	/* append tag
326 	 * device will fill in the tag, we just need to append a placeholder
327 	 * use socket memory to improve coalescing (re-using a single buffer
328 	 * increases frag count)
329 	 * if we can't allocate memory now, steal some back from data
330 	 */
331 	if (likely(skb_page_frag_refill(prot->tag_size, pfrag,
332 					sk->sk_allocation))) {
333 		ret = 0;
334 		tls_append_frag(record, pfrag, prot->tag_size);
335 	} else {
336 		ret = prot->tag_size;
337 		if (record->len <= prot->overhead_size)
338 			return -ENOMEM;
339 	}
340 
341 	/* fill prepend */
342 	tls_fill_prepend(ctx, skb_frag_address(&record->frags[0]),
343 			 record->len - prot->overhead_size,
344 			 record_type);
345 	return ret;
346 }
347 
348 static int tls_create_new_record(struct tls_offload_context_tx *offload_ctx,
349 				 struct page_frag *pfrag,
350 				 size_t prepend_size)
351 {
352 	struct tls_record_info *record;
353 	skb_frag_t *frag;
354 
355 	record = kmalloc(sizeof(*record), GFP_KERNEL);
356 	if (!record)
357 		return -ENOMEM;
358 
359 	frag = &record->frags[0];
360 	__skb_frag_set_page(frag, pfrag->page);
361 	skb_frag_off_set(frag, pfrag->offset);
362 	skb_frag_size_set(frag, prepend_size);
363 
364 	get_page(pfrag->page);
365 	pfrag->offset += prepend_size;
366 
367 	record->num_frags = 1;
368 	record->len = prepend_size;
369 	offload_ctx->open_record = record;
370 	return 0;
371 }
372 
373 static int tls_do_allocation(struct sock *sk,
374 			     struct tls_offload_context_tx *offload_ctx,
375 			     struct page_frag *pfrag,
376 			     size_t prepend_size)
377 {
378 	int ret;
379 
380 	if (!offload_ctx->open_record) {
381 		if (unlikely(!skb_page_frag_refill(prepend_size, pfrag,
382 						   sk->sk_allocation))) {
383 			READ_ONCE(sk->sk_prot)->enter_memory_pressure(sk);
384 			sk_stream_moderate_sndbuf(sk);
385 			return -ENOMEM;
386 		}
387 
388 		ret = tls_create_new_record(offload_ctx, pfrag, prepend_size);
389 		if (ret)
390 			return ret;
391 
392 		if (pfrag->size > pfrag->offset)
393 			return 0;
394 	}
395 
396 	if (!sk_page_frag_refill(sk, pfrag))
397 		return -ENOMEM;
398 
399 	return 0;
400 }
401 
402 static int tls_device_copy_data(void *addr, size_t bytes, struct iov_iter *i)
403 {
404 	size_t pre_copy, nocache;
405 
406 	pre_copy = ~((unsigned long)addr - 1) & (SMP_CACHE_BYTES - 1);
407 	if (pre_copy) {
408 		pre_copy = min(pre_copy, bytes);
409 		if (copy_from_iter(addr, pre_copy, i) != pre_copy)
410 			return -EFAULT;
411 		bytes -= pre_copy;
412 		addr += pre_copy;
413 	}
414 
415 	nocache = round_down(bytes, SMP_CACHE_BYTES);
416 	if (copy_from_iter_nocache(addr, nocache, i) != nocache)
417 		return -EFAULT;
418 	bytes -= nocache;
419 	addr += nocache;
420 
421 	if (bytes && copy_from_iter(addr, bytes, i) != bytes)
422 		return -EFAULT;
423 
424 	return 0;
425 }
426 
427 union tls_iter_offset {
428 	struct iov_iter *msg_iter;
429 	int offset;
430 };
431 
432 static int tls_push_data(struct sock *sk,
433 			 union tls_iter_offset iter_offset,
434 			 size_t size, int flags,
435 			 unsigned char record_type,
436 			 struct page *zc_page)
437 {
438 	struct tls_context *tls_ctx = tls_get_ctx(sk);
439 	struct tls_prot_info *prot = &tls_ctx->prot_info;
440 	struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
441 	struct tls_record_info *record;
442 	int tls_push_record_flags;
443 	struct page_frag *pfrag;
444 	size_t orig_size = size;
445 	u32 max_open_record_len;
446 	bool more = false;
447 	bool done = false;
448 	int copy, rc = 0;
449 	long timeo;
450 
451 	if (flags &
452 	    ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL | MSG_SENDPAGE_NOTLAST))
453 		return -EOPNOTSUPP;
454 
455 	if (unlikely(sk->sk_err))
456 		return -sk->sk_err;
457 
458 	flags |= MSG_SENDPAGE_DECRYPTED;
459 	tls_push_record_flags = flags | MSG_SENDPAGE_NOTLAST;
460 
461 	timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
462 	if (tls_is_partially_sent_record(tls_ctx)) {
463 		rc = tls_push_partial_record(sk, tls_ctx, flags);
464 		if (rc < 0)
465 			return rc;
466 	}
467 
468 	pfrag = sk_page_frag(sk);
469 
470 	/* TLS_HEADER_SIZE is not counted as part of the TLS record, and
471 	 * we need to leave room for an authentication tag.
472 	 */
473 	max_open_record_len = TLS_MAX_PAYLOAD_SIZE +
474 			      prot->prepend_size;
475 	do {
476 		rc = tls_do_allocation(sk, ctx, pfrag, prot->prepend_size);
477 		if (unlikely(rc)) {
478 			rc = sk_stream_wait_memory(sk, &timeo);
479 			if (!rc)
480 				continue;
481 
482 			record = ctx->open_record;
483 			if (!record)
484 				break;
485 handle_error:
486 			if (record_type != TLS_RECORD_TYPE_DATA) {
487 				/* avoid sending partial
488 				 * record with type !=
489 				 * application_data
490 				 */
491 				size = orig_size;
492 				destroy_record(record);
493 				ctx->open_record = NULL;
494 			} else if (record->len > prot->prepend_size) {
495 				goto last_record;
496 			}
497 
498 			break;
499 		}
500 
501 		record = ctx->open_record;
502 
503 		copy = min_t(size_t, size, max_open_record_len - record->len);
504 		if (copy && zc_page) {
505 			struct page_frag zc_pfrag;
506 
507 			zc_pfrag.page = zc_page;
508 			zc_pfrag.offset = iter_offset.offset;
509 			zc_pfrag.size = copy;
510 			tls_append_frag(record, &zc_pfrag, copy);
511 		} else if (copy) {
512 			copy = min_t(size_t, copy, pfrag->size - pfrag->offset);
513 
514 			rc = tls_device_copy_data(page_address(pfrag->page) +
515 						  pfrag->offset, copy,
516 						  iter_offset.msg_iter);
517 			if (rc)
518 				goto handle_error;
519 			tls_append_frag(record, pfrag, copy);
520 		}
521 
522 		size -= copy;
523 		if (!size) {
524 last_record:
525 			tls_push_record_flags = flags;
526 			if (flags & (MSG_SENDPAGE_NOTLAST | MSG_MORE)) {
527 				more = true;
528 				break;
529 			}
530 
531 			done = true;
532 		}
533 
534 		if (done || record->len >= max_open_record_len ||
535 		    (record->num_frags >= MAX_SKB_FRAGS - 1)) {
536 			rc = tls_device_record_close(sk, tls_ctx, record,
537 						     pfrag, record_type);
538 			if (rc) {
539 				if (rc > 0) {
540 					size += rc;
541 				} else {
542 					size = orig_size;
543 					destroy_record(record);
544 					ctx->open_record = NULL;
545 					break;
546 				}
547 			}
548 
549 			rc = tls_push_record(sk,
550 					     tls_ctx,
551 					     ctx,
552 					     record,
553 					     tls_push_record_flags);
554 			if (rc < 0)
555 				break;
556 		}
557 	} while (!done);
558 
559 	tls_ctx->pending_open_record_frags = more;
560 
561 	if (orig_size - size > 0)
562 		rc = orig_size - size;
563 
564 	return rc;
565 }
566 
567 int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
568 {
569 	unsigned char record_type = TLS_RECORD_TYPE_DATA;
570 	struct tls_context *tls_ctx = tls_get_ctx(sk);
571 	union tls_iter_offset iter;
572 	int rc;
573 
574 	mutex_lock(&tls_ctx->tx_lock);
575 	lock_sock(sk);
576 
577 	if (unlikely(msg->msg_controllen)) {
578 		rc = tls_process_cmsg(sk, msg, &record_type);
579 		if (rc)
580 			goto out;
581 	}
582 
583 	iter.msg_iter = &msg->msg_iter;
584 	rc = tls_push_data(sk, iter, size, msg->msg_flags, record_type, NULL);
585 
586 out:
587 	release_sock(sk);
588 	mutex_unlock(&tls_ctx->tx_lock);
589 	return rc;
590 }
591 
592 int tls_device_sendpage(struct sock *sk, struct page *page,
593 			int offset, size_t size, int flags)
594 {
595 	struct tls_context *tls_ctx = tls_get_ctx(sk);
596 	union tls_iter_offset iter_offset;
597 	struct iov_iter msg_iter;
598 	char *kaddr;
599 	struct kvec iov;
600 	int rc;
601 
602 	if (flags & MSG_SENDPAGE_NOTLAST)
603 		flags |= MSG_MORE;
604 
605 	mutex_lock(&tls_ctx->tx_lock);
606 	lock_sock(sk);
607 
608 	if (flags & MSG_OOB) {
609 		rc = -EOPNOTSUPP;
610 		goto out;
611 	}
612 
613 	if (tls_ctx->zerocopy_sendfile) {
614 		iter_offset.offset = offset;
615 		rc = tls_push_data(sk, iter_offset, size,
616 				   flags, TLS_RECORD_TYPE_DATA, page);
617 		goto out;
618 	}
619 
620 	kaddr = kmap(page);
621 	iov.iov_base = kaddr + offset;
622 	iov.iov_len = size;
623 	iov_iter_kvec(&msg_iter, WRITE, &iov, 1, size);
624 	iter_offset.msg_iter = &msg_iter;
625 	rc = tls_push_data(sk, iter_offset, size, flags, TLS_RECORD_TYPE_DATA,
626 			   NULL);
627 	kunmap(page);
628 
629 out:
630 	release_sock(sk);
631 	mutex_unlock(&tls_ctx->tx_lock);
632 	return rc;
633 }
634 
635 struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context,
636 				       u32 seq, u64 *p_record_sn)
637 {
638 	u64 record_sn = context->hint_record_sn;
639 	struct tls_record_info *info, *last;
640 
641 	info = context->retransmit_hint;
642 	if (!info ||
643 	    before(seq, info->end_seq - info->len)) {
644 		/* if retransmit_hint is irrelevant start
645 		 * from the beginning of the list
646 		 */
647 		info = list_first_entry_or_null(&context->records_list,
648 						struct tls_record_info, list);
649 		if (!info)
650 			return NULL;
651 		/* send the start_marker record if seq number is before the
652 		 * tls offload start marker sequence number. This record is
653 		 * required to handle TCP packets which are before TLS offload
654 		 * started.
655 		 *  And if it's not start marker, look if this seq number
656 		 * belongs to the list.
657 		 */
658 		if (likely(!tls_record_is_start_marker(info))) {
659 			/* we have the first record, get the last record to see
660 			 * if this seq number belongs to the list.
661 			 */
662 			last = list_last_entry(&context->records_list,
663 					       struct tls_record_info, list);
664 
665 			if (!between(seq, tls_record_start_seq(info),
666 				     last->end_seq))
667 				return NULL;
668 		}
669 		record_sn = context->unacked_record_sn;
670 	}
671 
672 	/* We just need the _rcu for the READ_ONCE() */
673 	rcu_read_lock();
674 	list_for_each_entry_from_rcu(info, &context->records_list, list) {
675 		if (before(seq, info->end_seq)) {
676 			if (!context->retransmit_hint ||
677 			    after(info->end_seq,
678 				  context->retransmit_hint->end_seq)) {
679 				context->hint_record_sn = record_sn;
680 				context->retransmit_hint = info;
681 			}
682 			*p_record_sn = record_sn;
683 			goto exit_rcu_unlock;
684 		}
685 		record_sn++;
686 	}
687 	info = NULL;
688 
689 exit_rcu_unlock:
690 	rcu_read_unlock();
691 	return info;
692 }
693 EXPORT_SYMBOL(tls_get_record);
694 
695 static int tls_device_push_pending_record(struct sock *sk, int flags)
696 {
697 	union tls_iter_offset iter;
698 	struct iov_iter msg_iter;
699 
700 	iov_iter_kvec(&msg_iter, WRITE, NULL, 0, 0);
701 	iter.msg_iter = &msg_iter;
702 	return tls_push_data(sk, iter, 0, flags, TLS_RECORD_TYPE_DATA, NULL);
703 }
704 
705 void tls_device_write_space(struct sock *sk, struct tls_context *ctx)
706 {
707 	if (tls_is_partially_sent_record(ctx)) {
708 		gfp_t sk_allocation = sk->sk_allocation;
709 
710 		WARN_ON_ONCE(sk->sk_write_pending);
711 
712 		sk->sk_allocation = GFP_ATOMIC;
713 		tls_push_partial_record(sk, ctx,
714 					MSG_DONTWAIT | MSG_NOSIGNAL |
715 					MSG_SENDPAGE_DECRYPTED);
716 		sk->sk_allocation = sk_allocation;
717 	}
718 }
719 
720 static void tls_device_resync_rx(struct tls_context *tls_ctx,
721 				 struct sock *sk, u32 seq, u8 *rcd_sn)
722 {
723 	struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
724 	struct net_device *netdev;
725 
726 	trace_tls_device_rx_resync_send(sk, seq, rcd_sn, rx_ctx->resync_type);
727 	rcu_read_lock();
728 	netdev = rcu_dereference(tls_ctx->netdev);
729 	if (netdev)
730 		netdev->tlsdev_ops->tls_dev_resync(netdev, sk, seq, rcd_sn,
731 						   TLS_OFFLOAD_CTX_DIR_RX);
732 	rcu_read_unlock();
733 	TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSRXDEVICERESYNC);
734 }
735 
736 static bool
737 tls_device_rx_resync_async(struct tls_offload_resync_async *resync_async,
738 			   s64 resync_req, u32 *seq, u16 *rcd_delta)
739 {
740 	u32 is_async = resync_req & RESYNC_REQ_ASYNC;
741 	u32 req_seq = resync_req >> 32;
742 	u32 req_end = req_seq + ((resync_req >> 16) & 0xffff);
743 	u16 i;
744 
745 	*rcd_delta = 0;
746 
747 	if (is_async) {
748 		/* shouldn't get to wraparound:
749 		 * too long in async stage, something bad happened
750 		 */
751 		if (WARN_ON_ONCE(resync_async->rcd_delta == USHRT_MAX))
752 			return false;
753 
754 		/* asynchronous stage: log all headers seq such that
755 		 * req_seq <= seq <= end_seq, and wait for real resync request
756 		 */
757 		if (before(*seq, req_seq))
758 			return false;
759 		if (!after(*seq, req_end) &&
760 		    resync_async->loglen < TLS_DEVICE_RESYNC_ASYNC_LOGMAX)
761 			resync_async->log[resync_async->loglen++] = *seq;
762 
763 		resync_async->rcd_delta++;
764 
765 		return false;
766 	}
767 
768 	/* synchronous stage: check against the logged entries and
769 	 * proceed to check the next entries if no match was found
770 	 */
771 	for (i = 0; i < resync_async->loglen; i++)
772 		if (req_seq == resync_async->log[i] &&
773 		    atomic64_try_cmpxchg(&resync_async->req, &resync_req, 0)) {
774 			*rcd_delta = resync_async->rcd_delta - i;
775 			*seq = req_seq;
776 			resync_async->loglen = 0;
777 			resync_async->rcd_delta = 0;
778 			return true;
779 		}
780 
781 	resync_async->loglen = 0;
782 	resync_async->rcd_delta = 0;
783 
784 	if (req_seq == *seq &&
785 	    atomic64_try_cmpxchg(&resync_async->req,
786 				 &resync_req, 0))
787 		return true;
788 
789 	return false;
790 }
791 
792 void tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq)
793 {
794 	struct tls_context *tls_ctx = tls_get_ctx(sk);
795 	struct tls_offload_context_rx *rx_ctx;
796 	u8 rcd_sn[TLS_MAX_REC_SEQ_SIZE];
797 	u32 sock_data, is_req_pending;
798 	struct tls_prot_info *prot;
799 	s64 resync_req;
800 	u16 rcd_delta;
801 	u32 req_seq;
802 
803 	if (tls_ctx->rx_conf != TLS_HW)
804 		return;
805 	if (unlikely(test_bit(TLS_RX_DEV_DEGRADED, &tls_ctx->flags)))
806 		return;
807 
808 	prot = &tls_ctx->prot_info;
809 	rx_ctx = tls_offload_ctx_rx(tls_ctx);
810 	memcpy(rcd_sn, tls_ctx->rx.rec_seq, prot->rec_seq_size);
811 
812 	switch (rx_ctx->resync_type) {
813 	case TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ:
814 		resync_req = atomic64_read(&rx_ctx->resync_req);
815 		req_seq = resync_req >> 32;
816 		seq += TLS_HEADER_SIZE - 1;
817 		is_req_pending = resync_req;
818 
819 		if (likely(!is_req_pending) || req_seq != seq ||
820 		    !atomic64_try_cmpxchg(&rx_ctx->resync_req, &resync_req, 0))
821 			return;
822 		break;
823 	case TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT:
824 		if (likely(!rx_ctx->resync_nh_do_now))
825 			return;
826 
827 		/* head of next rec is already in, note that the sock_inq will
828 		 * include the currently parsed message when called from parser
829 		 */
830 		sock_data = tcp_inq(sk);
831 		if (sock_data > rcd_len) {
832 			trace_tls_device_rx_resync_nh_delay(sk, sock_data,
833 							    rcd_len);
834 			return;
835 		}
836 
837 		rx_ctx->resync_nh_do_now = 0;
838 		seq += rcd_len;
839 		tls_bigint_increment(rcd_sn, prot->rec_seq_size);
840 		break;
841 	case TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ_ASYNC:
842 		resync_req = atomic64_read(&rx_ctx->resync_async->req);
843 		is_req_pending = resync_req;
844 		if (likely(!is_req_pending))
845 			return;
846 
847 		if (!tls_device_rx_resync_async(rx_ctx->resync_async,
848 						resync_req, &seq, &rcd_delta))
849 			return;
850 		tls_bigint_subtract(rcd_sn, rcd_delta);
851 		break;
852 	}
853 
854 	tls_device_resync_rx(tls_ctx, sk, seq, rcd_sn);
855 }
856 
857 static void tls_device_core_ctrl_rx_resync(struct tls_context *tls_ctx,
858 					   struct tls_offload_context_rx *ctx,
859 					   struct sock *sk, struct sk_buff *skb)
860 {
861 	struct strp_msg *rxm;
862 
863 	/* device will request resyncs by itself based on stream scan */
864 	if (ctx->resync_type != TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT)
865 		return;
866 	/* already scheduled */
867 	if (ctx->resync_nh_do_now)
868 		return;
869 	/* seen decrypted fragments since last fully-failed record */
870 	if (ctx->resync_nh_reset) {
871 		ctx->resync_nh_reset = 0;
872 		ctx->resync_nh.decrypted_failed = 1;
873 		ctx->resync_nh.decrypted_tgt = TLS_DEVICE_RESYNC_NH_START_IVAL;
874 		return;
875 	}
876 
877 	if (++ctx->resync_nh.decrypted_failed <= ctx->resync_nh.decrypted_tgt)
878 		return;
879 
880 	/* doing resync, bump the next target in case it fails */
881 	if (ctx->resync_nh.decrypted_tgt < TLS_DEVICE_RESYNC_NH_MAX_IVAL)
882 		ctx->resync_nh.decrypted_tgt *= 2;
883 	else
884 		ctx->resync_nh.decrypted_tgt += TLS_DEVICE_RESYNC_NH_MAX_IVAL;
885 
886 	rxm = strp_msg(skb);
887 
888 	/* head of next rec is already in, parser will sync for us */
889 	if (tcp_inq(sk) > rxm->full_len) {
890 		trace_tls_device_rx_resync_nh_schedule(sk);
891 		ctx->resync_nh_do_now = 1;
892 	} else {
893 		struct tls_prot_info *prot = &tls_ctx->prot_info;
894 		u8 rcd_sn[TLS_MAX_REC_SEQ_SIZE];
895 
896 		memcpy(rcd_sn, tls_ctx->rx.rec_seq, prot->rec_seq_size);
897 		tls_bigint_increment(rcd_sn, prot->rec_seq_size);
898 
899 		tls_device_resync_rx(tls_ctx, sk, tcp_sk(sk)->copied_seq,
900 				     rcd_sn);
901 	}
902 }
903 
904 static int
905 tls_device_reencrypt(struct sock *sk, struct tls_sw_context_rx *sw_ctx)
906 {
907 	int err, offset, copy, data_len, pos;
908 	struct sk_buff *skb, *skb_iter;
909 	struct scatterlist sg[1];
910 	struct strp_msg *rxm;
911 	char *orig_buf, *buf;
912 
913 	rxm = strp_msg(tls_strp_msg(sw_ctx));
914 	orig_buf = kmalloc(rxm->full_len + TLS_HEADER_SIZE +
915 			   TLS_CIPHER_AES_GCM_128_IV_SIZE, sk->sk_allocation);
916 	if (!orig_buf)
917 		return -ENOMEM;
918 	buf = orig_buf;
919 
920 	err = tls_strp_msg_cow(sw_ctx);
921 	if (unlikely(err))
922 		goto free_buf;
923 
924 	skb = tls_strp_msg(sw_ctx);
925 	rxm = strp_msg(skb);
926 	offset = rxm->offset;
927 
928 	sg_init_table(sg, 1);
929 	sg_set_buf(&sg[0], buf,
930 		   rxm->full_len + TLS_HEADER_SIZE +
931 		   TLS_CIPHER_AES_GCM_128_IV_SIZE);
932 	err = skb_copy_bits(skb, offset, buf,
933 			    TLS_HEADER_SIZE + TLS_CIPHER_AES_GCM_128_IV_SIZE);
934 	if (err)
935 		goto free_buf;
936 
937 	/* We are interested only in the decrypted data not the auth */
938 	err = decrypt_skb(sk, sg);
939 	if (err != -EBADMSG)
940 		goto free_buf;
941 	else
942 		err = 0;
943 
944 	data_len = rxm->full_len - TLS_CIPHER_AES_GCM_128_TAG_SIZE;
945 
946 	if (skb_pagelen(skb) > offset) {
947 		copy = min_t(int, skb_pagelen(skb) - offset, data_len);
948 
949 		if (skb->decrypted) {
950 			err = skb_store_bits(skb, offset, buf, copy);
951 			if (err)
952 				goto free_buf;
953 		}
954 
955 		offset += copy;
956 		buf += copy;
957 	}
958 
959 	pos = skb_pagelen(skb);
960 	skb_walk_frags(skb, skb_iter) {
961 		int frag_pos;
962 
963 		/* Practically all frags must belong to msg if reencrypt
964 		 * is needed with current strparser and coalescing logic,
965 		 * but strparser may "get optimized", so let's be safe.
966 		 */
967 		if (pos + skb_iter->len <= offset)
968 			goto done_with_frag;
969 		if (pos >= data_len + rxm->offset)
970 			break;
971 
972 		frag_pos = offset - pos;
973 		copy = min_t(int, skb_iter->len - frag_pos,
974 			     data_len + rxm->offset - offset);
975 
976 		if (skb_iter->decrypted) {
977 			err = skb_store_bits(skb_iter, frag_pos, buf, copy);
978 			if (err)
979 				goto free_buf;
980 		}
981 
982 		offset += copy;
983 		buf += copy;
984 done_with_frag:
985 		pos += skb_iter->len;
986 	}
987 
988 free_buf:
989 	kfree(orig_buf);
990 	return err;
991 }
992 
993 int tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx)
994 {
995 	struct tls_offload_context_rx *ctx = tls_offload_ctx_rx(tls_ctx);
996 	struct tls_sw_context_rx *sw_ctx = tls_sw_ctx_rx(tls_ctx);
997 	struct sk_buff *skb = tls_strp_msg(sw_ctx);
998 	struct strp_msg *rxm = strp_msg(skb);
999 	int is_decrypted = skb->decrypted;
1000 	int is_encrypted = !is_decrypted;
1001 	struct sk_buff *skb_iter;
1002 	int left;
1003 
1004 	left = rxm->full_len - skb->len;
1005 	/* Check if all the data is decrypted already */
1006 	skb_iter = skb_shinfo(skb)->frag_list;
1007 	while (skb_iter && left > 0) {
1008 		is_decrypted &= skb_iter->decrypted;
1009 		is_encrypted &= !skb_iter->decrypted;
1010 
1011 		left -= skb_iter->len;
1012 		skb_iter = skb_iter->next;
1013 	}
1014 
1015 	trace_tls_device_decrypted(sk, tcp_sk(sk)->copied_seq - rxm->full_len,
1016 				   tls_ctx->rx.rec_seq, rxm->full_len,
1017 				   is_encrypted, is_decrypted);
1018 
1019 	if (unlikely(test_bit(TLS_RX_DEV_DEGRADED, &tls_ctx->flags))) {
1020 		if (likely(is_encrypted || is_decrypted))
1021 			return is_decrypted;
1022 
1023 		/* After tls_device_down disables the offload, the next SKB will
1024 		 * likely have initial fragments decrypted, and final ones not
1025 		 * decrypted. We need to reencrypt that single SKB.
1026 		 */
1027 		return tls_device_reencrypt(sk, sw_ctx);
1028 	}
1029 
1030 	/* Return immediately if the record is either entirely plaintext or
1031 	 * entirely ciphertext. Otherwise handle reencrypt partially decrypted
1032 	 * record.
1033 	 */
1034 	if (is_decrypted) {
1035 		ctx->resync_nh_reset = 1;
1036 		return is_decrypted;
1037 	}
1038 	if (is_encrypted) {
1039 		tls_device_core_ctrl_rx_resync(tls_ctx, ctx, sk, skb);
1040 		return 0;
1041 	}
1042 
1043 	ctx->resync_nh_reset = 1;
1044 	return tls_device_reencrypt(sk, sw_ctx);
1045 }
1046 
1047 static void tls_device_attach(struct tls_context *ctx, struct sock *sk,
1048 			      struct net_device *netdev)
1049 {
1050 	if (sk->sk_destruct != tls_device_sk_destruct) {
1051 		refcount_set(&ctx->refcount, 1);
1052 		dev_hold(netdev);
1053 		RCU_INIT_POINTER(ctx->netdev, netdev);
1054 		spin_lock_irq(&tls_device_lock);
1055 		list_add_tail(&ctx->list, &tls_device_list);
1056 		spin_unlock_irq(&tls_device_lock);
1057 
1058 		ctx->sk_destruct = sk->sk_destruct;
1059 		smp_store_release(&sk->sk_destruct, tls_device_sk_destruct);
1060 	}
1061 }
1062 
1063 int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
1064 {
1065 	u16 nonce_size, tag_size, iv_size, rec_seq_size, salt_size;
1066 	struct tls_context *tls_ctx = tls_get_ctx(sk);
1067 	struct tls_prot_info *prot = &tls_ctx->prot_info;
1068 	struct tls_record_info *start_marker_record;
1069 	struct tls_offload_context_tx *offload_ctx;
1070 	struct tls_crypto_info *crypto_info;
1071 	struct net_device *netdev;
1072 	char *iv, *rec_seq;
1073 	struct sk_buff *skb;
1074 	__be64 rcd_sn;
1075 	int rc;
1076 
1077 	if (!ctx)
1078 		return -EINVAL;
1079 
1080 	if (ctx->priv_ctx_tx)
1081 		return -EEXIST;
1082 
1083 	netdev = get_netdev_for_sock(sk);
1084 	if (!netdev) {
1085 		pr_err_ratelimited("%s: netdev not found\n", __func__);
1086 		return -EINVAL;
1087 	}
1088 
1089 	if (!(netdev->features & NETIF_F_HW_TLS_TX)) {
1090 		rc = -EOPNOTSUPP;
1091 		goto release_netdev;
1092 	}
1093 
1094 	crypto_info = &ctx->crypto_send.info;
1095 	if (crypto_info->version != TLS_1_2_VERSION) {
1096 		rc = -EOPNOTSUPP;
1097 		goto release_netdev;
1098 	}
1099 
1100 	switch (crypto_info->cipher_type) {
1101 	case TLS_CIPHER_AES_GCM_128:
1102 		nonce_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
1103 		tag_size = TLS_CIPHER_AES_GCM_128_TAG_SIZE;
1104 		iv_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
1105 		iv = ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->iv;
1106 		rec_seq_size = TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE;
1107 		salt_size = TLS_CIPHER_AES_GCM_128_SALT_SIZE;
1108 		rec_seq =
1109 		 ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->rec_seq;
1110 		break;
1111 	default:
1112 		rc = -EINVAL;
1113 		goto release_netdev;
1114 	}
1115 
1116 	/* Sanity-check the rec_seq_size for stack allocations */
1117 	if (rec_seq_size > TLS_MAX_REC_SEQ_SIZE) {
1118 		rc = -EINVAL;
1119 		goto release_netdev;
1120 	}
1121 
1122 	prot->version = crypto_info->version;
1123 	prot->cipher_type = crypto_info->cipher_type;
1124 	prot->prepend_size = TLS_HEADER_SIZE + nonce_size;
1125 	prot->tag_size = tag_size;
1126 	prot->overhead_size = prot->prepend_size + prot->tag_size;
1127 	prot->iv_size = iv_size;
1128 	prot->salt_size = salt_size;
1129 	ctx->tx.iv = kmalloc(iv_size + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
1130 			     GFP_KERNEL);
1131 	if (!ctx->tx.iv) {
1132 		rc = -ENOMEM;
1133 		goto release_netdev;
1134 	}
1135 
1136 	memcpy(ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv, iv_size);
1137 
1138 	prot->rec_seq_size = rec_seq_size;
1139 	ctx->tx.rec_seq = kmemdup(rec_seq, rec_seq_size, GFP_KERNEL);
1140 	if (!ctx->tx.rec_seq) {
1141 		rc = -ENOMEM;
1142 		goto free_iv;
1143 	}
1144 
1145 	start_marker_record = kmalloc(sizeof(*start_marker_record), GFP_KERNEL);
1146 	if (!start_marker_record) {
1147 		rc = -ENOMEM;
1148 		goto free_rec_seq;
1149 	}
1150 
1151 	offload_ctx = kzalloc(TLS_OFFLOAD_CONTEXT_SIZE_TX, GFP_KERNEL);
1152 	if (!offload_ctx) {
1153 		rc = -ENOMEM;
1154 		goto free_marker_record;
1155 	}
1156 
1157 	rc = tls_sw_fallback_init(sk, offload_ctx, crypto_info);
1158 	if (rc)
1159 		goto free_offload_ctx;
1160 
1161 	/* start at rec_seq - 1 to account for the start marker record */
1162 	memcpy(&rcd_sn, ctx->tx.rec_seq, sizeof(rcd_sn));
1163 	offload_ctx->unacked_record_sn = be64_to_cpu(rcd_sn) - 1;
1164 
1165 	start_marker_record->end_seq = tcp_sk(sk)->write_seq;
1166 	start_marker_record->len = 0;
1167 	start_marker_record->num_frags = 0;
1168 
1169 	INIT_WORK(&offload_ctx->destruct_work, tls_device_tx_del_task);
1170 	offload_ctx->ctx = ctx;
1171 
1172 	INIT_LIST_HEAD(&offload_ctx->records_list);
1173 	list_add_tail(&start_marker_record->list, &offload_ctx->records_list);
1174 	spin_lock_init(&offload_ctx->lock);
1175 	sg_init_table(offload_ctx->sg_tx_data,
1176 		      ARRAY_SIZE(offload_ctx->sg_tx_data));
1177 
1178 	clean_acked_data_enable(inet_csk(sk), &tls_icsk_clean_acked);
1179 	ctx->push_pending_record = tls_device_push_pending_record;
1180 
1181 	/* TLS offload is greatly simplified if we don't send
1182 	 * SKBs where only part of the payload needs to be encrypted.
1183 	 * So mark the last skb in the write queue as end of record.
1184 	 */
1185 	skb = tcp_write_queue_tail(sk);
1186 	if (skb)
1187 		TCP_SKB_CB(skb)->eor = 1;
1188 
1189 	/* Avoid offloading if the device is down
1190 	 * We don't want to offload new flows after
1191 	 * the NETDEV_DOWN event
1192 	 *
1193 	 * device_offload_lock is taken in tls_devices's NETDEV_DOWN
1194 	 * handler thus protecting from the device going down before
1195 	 * ctx was added to tls_device_list.
1196 	 */
1197 	down_read(&device_offload_lock);
1198 	if (!(netdev->flags & IFF_UP)) {
1199 		rc = -EINVAL;
1200 		goto release_lock;
1201 	}
1202 
1203 	ctx->priv_ctx_tx = offload_ctx;
1204 	rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_TX,
1205 					     &ctx->crypto_send.info,
1206 					     tcp_sk(sk)->write_seq);
1207 	trace_tls_device_offload_set(sk, TLS_OFFLOAD_CTX_DIR_TX,
1208 				     tcp_sk(sk)->write_seq, rec_seq, rc);
1209 	if (rc)
1210 		goto release_lock;
1211 
1212 	tls_device_attach(ctx, sk, netdev);
1213 	up_read(&device_offload_lock);
1214 
1215 	/* following this assignment tls_is_sk_tx_device_offloaded
1216 	 * will return true and the context might be accessed
1217 	 * by the netdev's xmit function.
1218 	 */
1219 	smp_store_release(&sk->sk_validate_xmit_skb, tls_validate_xmit_skb);
1220 	dev_put(netdev);
1221 
1222 	return 0;
1223 
1224 release_lock:
1225 	up_read(&device_offload_lock);
1226 	clean_acked_data_disable(inet_csk(sk));
1227 	crypto_free_aead(offload_ctx->aead_send);
1228 free_offload_ctx:
1229 	kfree(offload_ctx);
1230 	ctx->priv_ctx_tx = NULL;
1231 free_marker_record:
1232 	kfree(start_marker_record);
1233 free_rec_seq:
1234 	kfree(ctx->tx.rec_seq);
1235 free_iv:
1236 	kfree(ctx->tx.iv);
1237 release_netdev:
1238 	dev_put(netdev);
1239 	return rc;
1240 }
1241 
1242 int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
1243 {
1244 	struct tls12_crypto_info_aes_gcm_128 *info;
1245 	struct tls_offload_context_rx *context;
1246 	struct net_device *netdev;
1247 	int rc = 0;
1248 
1249 	if (ctx->crypto_recv.info.version != TLS_1_2_VERSION)
1250 		return -EOPNOTSUPP;
1251 
1252 	netdev = get_netdev_for_sock(sk);
1253 	if (!netdev) {
1254 		pr_err_ratelimited("%s: netdev not found\n", __func__);
1255 		return -EINVAL;
1256 	}
1257 
1258 	if (!(netdev->features & NETIF_F_HW_TLS_RX)) {
1259 		rc = -EOPNOTSUPP;
1260 		goto release_netdev;
1261 	}
1262 
1263 	/* Avoid offloading if the device is down
1264 	 * We don't want to offload new flows after
1265 	 * the NETDEV_DOWN event
1266 	 *
1267 	 * device_offload_lock is taken in tls_devices's NETDEV_DOWN
1268 	 * handler thus protecting from the device going down before
1269 	 * ctx was added to tls_device_list.
1270 	 */
1271 	down_read(&device_offload_lock);
1272 	if (!(netdev->flags & IFF_UP)) {
1273 		rc = -EINVAL;
1274 		goto release_lock;
1275 	}
1276 
1277 	context = kzalloc(TLS_OFFLOAD_CONTEXT_SIZE_RX, GFP_KERNEL);
1278 	if (!context) {
1279 		rc = -ENOMEM;
1280 		goto release_lock;
1281 	}
1282 	context->resync_nh_reset = 1;
1283 
1284 	ctx->priv_ctx_rx = context;
1285 	rc = tls_set_sw_offload(sk, ctx, 0);
1286 	if (rc)
1287 		goto release_ctx;
1288 
1289 	rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_RX,
1290 					     &ctx->crypto_recv.info,
1291 					     tcp_sk(sk)->copied_seq);
1292 	info = (void *)&ctx->crypto_recv.info;
1293 	trace_tls_device_offload_set(sk, TLS_OFFLOAD_CTX_DIR_RX,
1294 				     tcp_sk(sk)->copied_seq, info->rec_seq, rc);
1295 	if (rc)
1296 		goto free_sw_resources;
1297 
1298 	tls_device_attach(ctx, sk, netdev);
1299 	up_read(&device_offload_lock);
1300 
1301 	dev_put(netdev);
1302 
1303 	return 0;
1304 
1305 free_sw_resources:
1306 	up_read(&device_offload_lock);
1307 	tls_sw_free_resources_rx(sk);
1308 	down_read(&device_offload_lock);
1309 release_ctx:
1310 	ctx->priv_ctx_rx = NULL;
1311 release_lock:
1312 	up_read(&device_offload_lock);
1313 release_netdev:
1314 	dev_put(netdev);
1315 	return rc;
1316 }
1317 
1318 void tls_device_offload_cleanup_rx(struct sock *sk)
1319 {
1320 	struct tls_context *tls_ctx = tls_get_ctx(sk);
1321 	struct net_device *netdev;
1322 
1323 	down_read(&device_offload_lock);
1324 	netdev = rcu_dereference_protected(tls_ctx->netdev,
1325 					   lockdep_is_held(&device_offload_lock));
1326 	if (!netdev)
1327 		goto out;
1328 
1329 	netdev->tlsdev_ops->tls_dev_del(netdev, tls_ctx,
1330 					TLS_OFFLOAD_CTX_DIR_RX);
1331 
1332 	if (tls_ctx->tx_conf != TLS_HW) {
1333 		dev_put(netdev);
1334 		rcu_assign_pointer(tls_ctx->netdev, NULL);
1335 	} else {
1336 		set_bit(TLS_RX_DEV_CLOSED, &tls_ctx->flags);
1337 	}
1338 out:
1339 	up_read(&device_offload_lock);
1340 	tls_sw_release_resources_rx(sk);
1341 }
1342 
1343 static int tls_device_down(struct net_device *netdev)
1344 {
1345 	struct tls_context *ctx, *tmp;
1346 	unsigned long flags;
1347 	LIST_HEAD(list);
1348 
1349 	/* Request a write lock to block new offload attempts */
1350 	down_write(&device_offload_lock);
1351 
1352 	spin_lock_irqsave(&tls_device_lock, flags);
1353 	list_for_each_entry_safe(ctx, tmp, &tls_device_list, list) {
1354 		struct net_device *ctx_netdev =
1355 			rcu_dereference_protected(ctx->netdev,
1356 						  lockdep_is_held(&device_offload_lock));
1357 
1358 		if (ctx_netdev != netdev ||
1359 		    !refcount_inc_not_zero(&ctx->refcount))
1360 			continue;
1361 
1362 		list_move(&ctx->list, &list);
1363 	}
1364 	spin_unlock_irqrestore(&tls_device_lock, flags);
1365 
1366 	list_for_each_entry_safe(ctx, tmp, &list, list)	{
1367 		/* Stop offloaded TX and switch to the fallback.
1368 		 * tls_is_sk_tx_device_offloaded will return false.
1369 		 */
1370 		WRITE_ONCE(ctx->sk->sk_validate_xmit_skb, tls_validate_xmit_skb_sw);
1371 
1372 		/* Stop the RX and TX resync.
1373 		 * tls_dev_resync must not be called after tls_dev_del.
1374 		 */
1375 		rcu_assign_pointer(ctx->netdev, NULL);
1376 
1377 		/* Start skipping the RX resync logic completely. */
1378 		set_bit(TLS_RX_DEV_DEGRADED, &ctx->flags);
1379 
1380 		/* Sync with inflight packets. After this point:
1381 		 * TX: no non-encrypted packets will be passed to the driver.
1382 		 * RX: resync requests from the driver will be ignored.
1383 		 */
1384 		synchronize_net();
1385 
1386 		/* Release the offload context on the driver side. */
1387 		if (ctx->tx_conf == TLS_HW)
1388 			netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
1389 							TLS_OFFLOAD_CTX_DIR_TX);
1390 		if (ctx->rx_conf == TLS_HW &&
1391 		    !test_bit(TLS_RX_DEV_CLOSED, &ctx->flags))
1392 			netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
1393 							TLS_OFFLOAD_CTX_DIR_RX);
1394 
1395 		dev_put(netdev);
1396 
1397 		/* Move the context to a separate list for two reasons:
1398 		 * 1. When the context is deallocated, list_del is called.
1399 		 * 2. It's no longer an offloaded context, so we don't want to
1400 		 *    run offload-specific code on this context.
1401 		 */
1402 		spin_lock_irqsave(&tls_device_lock, flags);
1403 		list_move_tail(&ctx->list, &tls_device_down_list);
1404 		spin_unlock_irqrestore(&tls_device_lock, flags);
1405 
1406 		/* Device contexts for RX and TX will be freed in on sk_destruct
1407 		 * by tls_device_free_ctx. rx_conf and tx_conf stay in TLS_HW.
1408 		 * Now release the ref taken above.
1409 		 */
1410 		if (refcount_dec_and_test(&ctx->refcount)) {
1411 			/* sk_destruct ran after tls_device_down took a ref, and
1412 			 * it returned early. Complete the destruction here.
1413 			 */
1414 			list_del(&ctx->list);
1415 			tls_device_free_ctx(ctx);
1416 		}
1417 	}
1418 
1419 	up_write(&device_offload_lock);
1420 
1421 	flush_workqueue(destruct_wq);
1422 
1423 	return NOTIFY_DONE;
1424 }
1425 
1426 static int tls_dev_event(struct notifier_block *this, unsigned long event,
1427 			 void *ptr)
1428 {
1429 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1430 
1431 	if (!dev->tlsdev_ops &&
1432 	    !(dev->features & (NETIF_F_HW_TLS_RX | NETIF_F_HW_TLS_TX)))
1433 		return NOTIFY_DONE;
1434 
1435 	switch (event) {
1436 	case NETDEV_REGISTER:
1437 	case NETDEV_FEAT_CHANGE:
1438 		if (netif_is_bond_master(dev))
1439 			return NOTIFY_DONE;
1440 		if ((dev->features & NETIF_F_HW_TLS_RX) &&
1441 		    !dev->tlsdev_ops->tls_dev_resync)
1442 			return NOTIFY_BAD;
1443 
1444 		if  (dev->tlsdev_ops &&
1445 		     dev->tlsdev_ops->tls_dev_add &&
1446 		     dev->tlsdev_ops->tls_dev_del)
1447 			return NOTIFY_DONE;
1448 		else
1449 			return NOTIFY_BAD;
1450 	case NETDEV_DOWN:
1451 		return tls_device_down(dev);
1452 	}
1453 	return NOTIFY_DONE;
1454 }
1455 
1456 static struct notifier_block tls_dev_notifier = {
1457 	.notifier_call	= tls_dev_event,
1458 };
1459 
1460 int __init tls_device_init(void)
1461 {
1462 	int err;
1463 
1464 	destruct_wq = alloc_workqueue("ktls_device_destruct", 0, 0);
1465 	if (!destruct_wq)
1466 		return -ENOMEM;
1467 
1468 	err = register_netdevice_notifier(&tls_dev_notifier);
1469 	if (err)
1470 		destroy_workqueue(destruct_wq);
1471 
1472 	return err;
1473 }
1474 
1475 void __exit tls_device_cleanup(void)
1476 {
1477 	unregister_netdevice_notifier(&tls_dev_notifier);
1478 	destroy_workqueue(destruct_wq);
1479 	clean_acked_data_flush();
1480 }
1481