xref: /openbmc/linux/net/tls/tls_device.c (revision 3557b3fd)
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 /* device_offload_lock is used to synchronize tls_dev_add
42  * against NETDEV_DOWN notifications.
43  */
44 static DECLARE_RWSEM(device_offload_lock);
45 
46 static void tls_device_gc_task(struct work_struct *work);
47 
48 static DECLARE_WORK(tls_device_gc_work, tls_device_gc_task);
49 static LIST_HEAD(tls_device_gc_list);
50 static LIST_HEAD(tls_device_list);
51 static DEFINE_SPINLOCK(tls_device_lock);
52 
53 static void tls_device_free_ctx(struct tls_context *ctx)
54 {
55 	if (ctx->tx_conf == TLS_HW) {
56 		kfree(tls_offload_ctx_tx(ctx));
57 		kfree(ctx->tx.rec_seq);
58 		kfree(ctx->tx.iv);
59 	}
60 
61 	if (ctx->rx_conf == TLS_HW)
62 		kfree(tls_offload_ctx_rx(ctx));
63 
64 	kfree(ctx);
65 }
66 
67 static void tls_device_gc_task(struct work_struct *work)
68 {
69 	struct tls_context *ctx, *tmp;
70 	unsigned long flags;
71 	LIST_HEAD(gc_list);
72 
73 	spin_lock_irqsave(&tls_device_lock, flags);
74 	list_splice_init(&tls_device_gc_list, &gc_list);
75 	spin_unlock_irqrestore(&tls_device_lock, flags);
76 
77 	list_for_each_entry_safe(ctx, tmp, &gc_list, list) {
78 		struct net_device *netdev = ctx->netdev;
79 
80 		if (netdev && ctx->tx_conf == TLS_HW) {
81 			netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
82 							TLS_OFFLOAD_CTX_DIR_TX);
83 			dev_put(netdev);
84 			ctx->netdev = NULL;
85 		}
86 
87 		list_del(&ctx->list);
88 		tls_device_free_ctx(ctx);
89 	}
90 }
91 
92 static void tls_device_attach(struct tls_context *ctx, struct sock *sk,
93 			      struct net_device *netdev)
94 {
95 	if (sk->sk_destruct != tls_device_sk_destruct) {
96 		refcount_set(&ctx->refcount, 1);
97 		dev_hold(netdev);
98 		ctx->netdev = netdev;
99 		spin_lock_irq(&tls_device_lock);
100 		list_add_tail(&ctx->list, &tls_device_list);
101 		spin_unlock_irq(&tls_device_lock);
102 
103 		ctx->sk_destruct = sk->sk_destruct;
104 		sk->sk_destruct = tls_device_sk_destruct;
105 	}
106 }
107 
108 static void tls_device_queue_ctx_destruction(struct tls_context *ctx)
109 {
110 	unsigned long flags;
111 
112 	spin_lock_irqsave(&tls_device_lock, flags);
113 	list_move_tail(&ctx->list, &tls_device_gc_list);
114 
115 	/* schedule_work inside the spinlock
116 	 * to make sure tls_device_down waits for that work.
117 	 */
118 	schedule_work(&tls_device_gc_work);
119 
120 	spin_unlock_irqrestore(&tls_device_lock, flags);
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 = dst->dev;
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 nr_frags = record->num_frags;
142 	skb_frag_t *frag;
143 
144 	while (nr_frags-- > 0) {
145 		frag = &record->frags[nr_frags];
146 		__skb_frag_unref(frag);
147 	}
148 	kfree(record);
149 }
150 
151 static void delete_all_records(struct tls_offload_context_tx *offload_ctx)
152 {
153 	struct tls_record_info *info, *temp;
154 
155 	list_for_each_entry_safe(info, temp, &offload_ctx->records_list, list) {
156 		list_del(&info->list);
157 		destroy_record(info);
158 	}
159 
160 	offload_ctx->retransmit_hint = NULL;
161 }
162 
163 static void tls_icsk_clean_acked(struct sock *sk, u32 acked_seq)
164 {
165 	struct tls_context *tls_ctx = tls_get_ctx(sk);
166 	struct tls_record_info *info, *temp;
167 	struct tls_offload_context_tx *ctx;
168 	u64 deleted_records = 0;
169 	unsigned long flags;
170 
171 	if (!tls_ctx)
172 		return;
173 
174 	ctx = tls_offload_ctx_tx(tls_ctx);
175 
176 	spin_lock_irqsave(&ctx->lock, flags);
177 	info = ctx->retransmit_hint;
178 	if (info && !before(acked_seq, info->end_seq)) {
179 		ctx->retransmit_hint = NULL;
180 		list_del(&info->list);
181 		destroy_record(info);
182 		deleted_records++;
183 	}
184 
185 	list_for_each_entry_safe(info, temp, &ctx->records_list, list) {
186 		if (before(acked_seq, info->end_seq))
187 			break;
188 		list_del(&info->list);
189 
190 		destroy_record(info);
191 		deleted_records++;
192 	}
193 
194 	ctx->unacked_record_sn += deleted_records;
195 	spin_unlock_irqrestore(&ctx->lock, flags);
196 }
197 
198 /* At this point, there should be no references on this
199  * socket and no in-flight SKBs associated with this
200  * socket, so it is safe to free all the resources.
201  */
202 void tls_device_sk_destruct(struct sock *sk)
203 {
204 	struct tls_context *tls_ctx = tls_get_ctx(sk);
205 	struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
206 
207 	tls_ctx->sk_destruct(sk);
208 
209 	if (tls_ctx->tx_conf == TLS_HW) {
210 		if (ctx->open_record)
211 			destroy_record(ctx->open_record);
212 		delete_all_records(ctx);
213 		crypto_free_aead(ctx->aead_send);
214 		clean_acked_data_disable(inet_csk(sk));
215 	}
216 
217 	if (refcount_dec_and_test(&tls_ctx->refcount))
218 		tls_device_queue_ctx_destruction(tls_ctx);
219 }
220 EXPORT_SYMBOL(tls_device_sk_destruct);
221 
222 void tls_device_free_resources_tx(struct sock *sk)
223 {
224 	struct tls_context *tls_ctx = tls_get_ctx(sk);
225 
226 	tls_free_partial_record(sk, tls_ctx);
227 }
228 
229 static void tls_append_frag(struct tls_record_info *record,
230 			    struct page_frag *pfrag,
231 			    int size)
232 {
233 	skb_frag_t *frag;
234 
235 	frag = &record->frags[record->num_frags - 1];
236 	if (frag->page.p == pfrag->page &&
237 	    frag->page_offset + frag->size == pfrag->offset) {
238 		frag->size += size;
239 	} else {
240 		++frag;
241 		frag->page.p = pfrag->page;
242 		frag->page_offset = pfrag->offset;
243 		frag->size = size;
244 		++record->num_frags;
245 		get_page(pfrag->page);
246 	}
247 
248 	pfrag->offset += size;
249 	record->len += size;
250 }
251 
252 static int tls_push_record(struct sock *sk,
253 			   struct tls_context *ctx,
254 			   struct tls_offload_context_tx *offload_ctx,
255 			   struct tls_record_info *record,
256 			   struct page_frag *pfrag,
257 			   int flags,
258 			   unsigned char record_type)
259 {
260 	struct tls_prot_info *prot = &ctx->prot_info;
261 	struct tcp_sock *tp = tcp_sk(sk);
262 	struct page_frag dummy_tag_frag;
263 	skb_frag_t *frag;
264 	int i;
265 
266 	/* fill prepend */
267 	frag = &record->frags[0];
268 	tls_fill_prepend(ctx,
269 			 skb_frag_address(frag),
270 			 record->len - prot->prepend_size,
271 			 record_type,
272 			 ctx->crypto_send.info.version);
273 
274 	/* HW doesn't care about the data in the tag, because it fills it. */
275 	dummy_tag_frag.page = skb_frag_page(frag);
276 	dummy_tag_frag.offset = 0;
277 
278 	tls_append_frag(record, &dummy_tag_frag, prot->tag_size);
279 	record->end_seq = tp->write_seq + record->len;
280 	spin_lock_irq(&offload_ctx->lock);
281 	list_add_tail(&record->list, &offload_ctx->records_list);
282 	spin_unlock_irq(&offload_ctx->lock);
283 	offload_ctx->open_record = NULL;
284 	tls_advance_record_sn(sk, &ctx->tx, ctx->crypto_send.info.version);
285 
286 	for (i = 0; i < record->num_frags; i++) {
287 		frag = &record->frags[i];
288 		sg_unmark_end(&offload_ctx->sg_tx_data[i]);
289 		sg_set_page(&offload_ctx->sg_tx_data[i], skb_frag_page(frag),
290 			    frag->size, frag->page_offset);
291 		sk_mem_charge(sk, frag->size);
292 		get_page(skb_frag_page(frag));
293 	}
294 	sg_mark_end(&offload_ctx->sg_tx_data[record->num_frags - 1]);
295 
296 	/* all ready, send */
297 	return tls_push_sg(sk, ctx, offload_ctx->sg_tx_data, 0, flags);
298 }
299 
300 static int tls_create_new_record(struct tls_offload_context_tx *offload_ctx,
301 				 struct page_frag *pfrag,
302 				 size_t prepend_size)
303 {
304 	struct tls_record_info *record;
305 	skb_frag_t *frag;
306 
307 	record = kmalloc(sizeof(*record), GFP_KERNEL);
308 	if (!record)
309 		return -ENOMEM;
310 
311 	frag = &record->frags[0];
312 	__skb_frag_set_page(frag, pfrag->page);
313 	frag->page_offset = pfrag->offset;
314 	skb_frag_size_set(frag, prepend_size);
315 
316 	get_page(pfrag->page);
317 	pfrag->offset += prepend_size;
318 
319 	record->num_frags = 1;
320 	record->len = prepend_size;
321 	offload_ctx->open_record = record;
322 	return 0;
323 }
324 
325 static int tls_do_allocation(struct sock *sk,
326 			     struct tls_offload_context_tx *offload_ctx,
327 			     struct page_frag *pfrag,
328 			     size_t prepend_size)
329 {
330 	int ret;
331 
332 	if (!offload_ctx->open_record) {
333 		if (unlikely(!skb_page_frag_refill(prepend_size, pfrag,
334 						   sk->sk_allocation))) {
335 			sk->sk_prot->enter_memory_pressure(sk);
336 			sk_stream_moderate_sndbuf(sk);
337 			return -ENOMEM;
338 		}
339 
340 		ret = tls_create_new_record(offload_ctx, pfrag, prepend_size);
341 		if (ret)
342 			return ret;
343 
344 		if (pfrag->size > pfrag->offset)
345 			return 0;
346 	}
347 
348 	if (!sk_page_frag_refill(sk, pfrag))
349 		return -ENOMEM;
350 
351 	return 0;
352 }
353 
354 static int tls_push_data(struct sock *sk,
355 			 struct iov_iter *msg_iter,
356 			 size_t size, int flags,
357 			 unsigned char record_type)
358 {
359 	struct tls_context *tls_ctx = tls_get_ctx(sk);
360 	struct tls_prot_info *prot = &tls_ctx->prot_info;
361 	struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
362 	int tls_push_record_flags = flags | MSG_SENDPAGE_NOTLAST;
363 	int more = flags & (MSG_SENDPAGE_NOTLAST | MSG_MORE);
364 	struct tls_record_info *record = ctx->open_record;
365 	struct page_frag *pfrag;
366 	size_t orig_size = size;
367 	u32 max_open_record_len;
368 	int copy, rc = 0;
369 	bool done = false;
370 	long timeo;
371 
372 	if (flags &
373 	    ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL | MSG_SENDPAGE_NOTLAST))
374 		return -ENOTSUPP;
375 
376 	if (sk->sk_err)
377 		return -sk->sk_err;
378 
379 	timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
380 	if (tls_is_partially_sent_record(tls_ctx)) {
381 		rc = tls_push_partial_record(sk, tls_ctx, flags);
382 		if (rc < 0)
383 			return rc;
384 	}
385 
386 	pfrag = sk_page_frag(sk);
387 
388 	/* TLS_HEADER_SIZE is not counted as part of the TLS record, and
389 	 * we need to leave room for an authentication tag.
390 	 */
391 	max_open_record_len = TLS_MAX_PAYLOAD_SIZE +
392 			      prot->prepend_size;
393 	do {
394 		rc = tls_do_allocation(sk, ctx, pfrag,
395 				       prot->prepend_size);
396 		if (rc) {
397 			rc = sk_stream_wait_memory(sk, &timeo);
398 			if (!rc)
399 				continue;
400 
401 			record = ctx->open_record;
402 			if (!record)
403 				break;
404 handle_error:
405 			if (record_type != TLS_RECORD_TYPE_DATA) {
406 				/* avoid sending partial
407 				 * record with type !=
408 				 * application_data
409 				 */
410 				size = orig_size;
411 				destroy_record(record);
412 				ctx->open_record = NULL;
413 			} else if (record->len > prot->prepend_size) {
414 				goto last_record;
415 			}
416 
417 			break;
418 		}
419 
420 		record = ctx->open_record;
421 		copy = min_t(size_t, size, (pfrag->size - pfrag->offset));
422 		copy = min_t(size_t, copy, (max_open_record_len - record->len));
423 
424 		if (copy_from_iter_nocache(page_address(pfrag->page) +
425 					       pfrag->offset,
426 					   copy, msg_iter) != copy) {
427 			rc = -EFAULT;
428 			goto handle_error;
429 		}
430 		tls_append_frag(record, pfrag, copy);
431 
432 		size -= copy;
433 		if (!size) {
434 last_record:
435 			tls_push_record_flags = flags;
436 			if (more) {
437 				tls_ctx->pending_open_record_frags =
438 						!!record->num_frags;
439 				break;
440 			}
441 
442 			done = true;
443 		}
444 
445 		if (done || record->len >= max_open_record_len ||
446 		    (record->num_frags >= MAX_SKB_FRAGS - 1)) {
447 			rc = tls_push_record(sk,
448 					     tls_ctx,
449 					     ctx,
450 					     record,
451 					     pfrag,
452 					     tls_push_record_flags,
453 					     record_type);
454 			if (rc < 0)
455 				break;
456 		}
457 	} while (!done);
458 
459 	if (orig_size - size > 0)
460 		rc = orig_size - size;
461 
462 	return rc;
463 }
464 
465 int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
466 {
467 	unsigned char record_type = TLS_RECORD_TYPE_DATA;
468 	int rc;
469 
470 	lock_sock(sk);
471 
472 	if (unlikely(msg->msg_controllen)) {
473 		rc = tls_proccess_cmsg(sk, msg, &record_type);
474 		if (rc)
475 			goto out;
476 	}
477 
478 	rc = tls_push_data(sk, &msg->msg_iter, size,
479 			   msg->msg_flags, record_type);
480 
481 out:
482 	release_sock(sk);
483 	return rc;
484 }
485 
486 int tls_device_sendpage(struct sock *sk, struct page *page,
487 			int offset, size_t size, int flags)
488 {
489 	struct iov_iter	msg_iter;
490 	char *kaddr = kmap(page);
491 	struct kvec iov;
492 	int rc;
493 
494 	if (flags & MSG_SENDPAGE_NOTLAST)
495 		flags |= MSG_MORE;
496 
497 	lock_sock(sk);
498 
499 	if (flags & MSG_OOB) {
500 		rc = -ENOTSUPP;
501 		goto out;
502 	}
503 
504 	iov.iov_base = kaddr + offset;
505 	iov.iov_len = size;
506 	iov_iter_kvec(&msg_iter, WRITE, &iov, 1, size);
507 	rc = tls_push_data(sk, &msg_iter, size,
508 			   flags, TLS_RECORD_TYPE_DATA);
509 	kunmap(page);
510 
511 out:
512 	release_sock(sk);
513 	return rc;
514 }
515 
516 struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context,
517 				       u32 seq, u64 *p_record_sn)
518 {
519 	u64 record_sn = context->hint_record_sn;
520 	struct tls_record_info *info;
521 
522 	info = context->retransmit_hint;
523 	if (!info ||
524 	    before(seq, info->end_seq - info->len)) {
525 		/* if retransmit_hint is irrelevant start
526 		 * from the beggining of the list
527 		 */
528 		info = list_first_entry(&context->records_list,
529 					struct tls_record_info, list);
530 		record_sn = context->unacked_record_sn;
531 	}
532 
533 	list_for_each_entry_from(info, &context->records_list, list) {
534 		if (before(seq, info->end_seq)) {
535 			if (!context->retransmit_hint ||
536 			    after(info->end_seq,
537 				  context->retransmit_hint->end_seq)) {
538 				context->hint_record_sn = record_sn;
539 				context->retransmit_hint = info;
540 			}
541 			*p_record_sn = record_sn;
542 			return info;
543 		}
544 		record_sn++;
545 	}
546 
547 	return NULL;
548 }
549 EXPORT_SYMBOL(tls_get_record);
550 
551 static int tls_device_push_pending_record(struct sock *sk, int flags)
552 {
553 	struct iov_iter	msg_iter;
554 
555 	iov_iter_kvec(&msg_iter, WRITE, NULL, 0, 0);
556 	return tls_push_data(sk, &msg_iter, 0, flags, TLS_RECORD_TYPE_DATA);
557 }
558 
559 void tls_device_write_space(struct sock *sk, struct tls_context *ctx)
560 {
561 	int rc = 0;
562 
563 	if (!sk->sk_write_pending && tls_is_partially_sent_record(ctx)) {
564 		gfp_t sk_allocation = sk->sk_allocation;
565 
566 		sk->sk_allocation = GFP_ATOMIC;
567 		rc = tls_push_partial_record(sk, ctx,
568 					     MSG_DONTWAIT | MSG_NOSIGNAL);
569 		sk->sk_allocation = sk_allocation;
570 	}
571 }
572 
573 void handle_device_resync(struct sock *sk, u32 seq, u64 rcd_sn)
574 {
575 	struct tls_context *tls_ctx = tls_get_ctx(sk);
576 	struct net_device *netdev = tls_ctx->netdev;
577 	struct tls_offload_context_rx *rx_ctx;
578 	u32 is_req_pending;
579 	s64 resync_req;
580 	u32 req_seq;
581 
582 	if (tls_ctx->rx_conf != TLS_HW)
583 		return;
584 
585 	rx_ctx = tls_offload_ctx_rx(tls_ctx);
586 	resync_req = atomic64_read(&rx_ctx->resync_req);
587 	req_seq = ntohl(resync_req >> 32) - ((u32)TLS_HEADER_SIZE - 1);
588 	is_req_pending = resync_req;
589 
590 	if (unlikely(is_req_pending) && req_seq == seq &&
591 	    atomic64_try_cmpxchg(&rx_ctx->resync_req, &resync_req, 0))
592 		netdev->tlsdev_ops->tls_dev_resync_rx(netdev, sk,
593 						      seq + TLS_HEADER_SIZE - 1,
594 						      rcd_sn);
595 }
596 
597 static int tls_device_reencrypt(struct sock *sk, struct sk_buff *skb)
598 {
599 	struct strp_msg *rxm = strp_msg(skb);
600 	int err = 0, offset = rxm->offset, copy, nsg;
601 	struct sk_buff *skb_iter, *unused;
602 	struct scatterlist sg[1];
603 	char *orig_buf, *buf;
604 
605 	orig_buf = kmalloc(rxm->full_len + TLS_HEADER_SIZE +
606 			   TLS_CIPHER_AES_GCM_128_IV_SIZE, sk->sk_allocation);
607 	if (!orig_buf)
608 		return -ENOMEM;
609 	buf = orig_buf;
610 
611 	nsg = skb_cow_data(skb, 0, &unused);
612 	if (unlikely(nsg < 0)) {
613 		err = nsg;
614 		goto free_buf;
615 	}
616 
617 	sg_init_table(sg, 1);
618 	sg_set_buf(&sg[0], buf,
619 		   rxm->full_len + TLS_HEADER_SIZE +
620 		   TLS_CIPHER_AES_GCM_128_IV_SIZE);
621 	skb_copy_bits(skb, offset, buf,
622 		      TLS_HEADER_SIZE + TLS_CIPHER_AES_GCM_128_IV_SIZE);
623 
624 	/* We are interested only in the decrypted data not the auth */
625 	err = decrypt_skb(sk, skb, sg);
626 	if (err != -EBADMSG)
627 		goto free_buf;
628 	else
629 		err = 0;
630 
631 	copy = min_t(int, skb_pagelen(skb) - offset,
632 		     rxm->full_len - TLS_CIPHER_AES_GCM_128_TAG_SIZE);
633 
634 	if (skb->decrypted)
635 		skb_store_bits(skb, offset, buf, copy);
636 
637 	offset += copy;
638 	buf += copy;
639 
640 	skb_walk_frags(skb, skb_iter) {
641 		copy = min_t(int, skb_iter->len,
642 			     rxm->full_len - offset + rxm->offset -
643 			     TLS_CIPHER_AES_GCM_128_TAG_SIZE);
644 
645 		if (skb_iter->decrypted)
646 			skb_store_bits(skb_iter, offset, buf, copy);
647 
648 		offset += copy;
649 		buf += copy;
650 	}
651 
652 free_buf:
653 	kfree(orig_buf);
654 	return err;
655 }
656 
657 int tls_device_decrypted(struct sock *sk, struct sk_buff *skb)
658 {
659 	struct tls_context *tls_ctx = tls_get_ctx(sk);
660 	struct tls_offload_context_rx *ctx = tls_offload_ctx_rx(tls_ctx);
661 	int is_decrypted = skb->decrypted;
662 	int is_encrypted = !is_decrypted;
663 	struct sk_buff *skb_iter;
664 
665 	/* Skip if it is already decrypted */
666 	if (ctx->sw.decrypted)
667 		return 0;
668 
669 	/* Check if all the data is decrypted already */
670 	skb_walk_frags(skb, skb_iter) {
671 		is_decrypted &= skb_iter->decrypted;
672 		is_encrypted &= !skb_iter->decrypted;
673 	}
674 
675 	ctx->sw.decrypted |= is_decrypted;
676 
677 	/* Return immedeatly if the record is either entirely plaintext or
678 	 * entirely ciphertext. Otherwise handle reencrypt partially decrypted
679 	 * record.
680 	 */
681 	return (is_encrypted || is_decrypted) ? 0 :
682 		tls_device_reencrypt(sk, skb);
683 }
684 
685 int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
686 {
687 	u16 nonce_size, tag_size, iv_size, rec_seq_size;
688 	struct tls_context *tls_ctx = tls_get_ctx(sk);
689 	struct tls_prot_info *prot = &tls_ctx->prot_info;
690 	struct tls_record_info *start_marker_record;
691 	struct tls_offload_context_tx *offload_ctx;
692 	struct tls_crypto_info *crypto_info;
693 	struct net_device *netdev;
694 	char *iv, *rec_seq;
695 	struct sk_buff *skb;
696 	int rc = -EINVAL;
697 	__be64 rcd_sn;
698 
699 	if (!ctx)
700 		goto out;
701 
702 	if (ctx->priv_ctx_tx) {
703 		rc = -EEXIST;
704 		goto out;
705 	}
706 
707 	start_marker_record = kmalloc(sizeof(*start_marker_record), GFP_KERNEL);
708 	if (!start_marker_record) {
709 		rc = -ENOMEM;
710 		goto out;
711 	}
712 
713 	offload_ctx = kzalloc(TLS_OFFLOAD_CONTEXT_SIZE_TX, GFP_KERNEL);
714 	if (!offload_ctx) {
715 		rc = -ENOMEM;
716 		goto free_marker_record;
717 	}
718 
719 	crypto_info = &ctx->crypto_send.info;
720 	switch (crypto_info->cipher_type) {
721 	case TLS_CIPHER_AES_GCM_128:
722 		nonce_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
723 		tag_size = TLS_CIPHER_AES_GCM_128_TAG_SIZE;
724 		iv_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
725 		iv = ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->iv;
726 		rec_seq_size = TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE;
727 		rec_seq =
728 		 ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->rec_seq;
729 		break;
730 	default:
731 		rc = -EINVAL;
732 		goto free_offload_ctx;
733 	}
734 
735 	prot->prepend_size = TLS_HEADER_SIZE + nonce_size;
736 	prot->tag_size = tag_size;
737 	prot->overhead_size = prot->prepend_size + prot->tag_size;
738 	prot->iv_size = iv_size;
739 	ctx->tx.iv = kmalloc(iv_size + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
740 			     GFP_KERNEL);
741 	if (!ctx->tx.iv) {
742 		rc = -ENOMEM;
743 		goto free_offload_ctx;
744 	}
745 
746 	memcpy(ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv, iv_size);
747 
748 	prot->rec_seq_size = rec_seq_size;
749 	ctx->tx.rec_seq = kmemdup(rec_seq, rec_seq_size, GFP_KERNEL);
750 	if (!ctx->tx.rec_seq) {
751 		rc = -ENOMEM;
752 		goto free_iv;
753 	}
754 
755 	rc = tls_sw_fallback_init(sk, offload_ctx, crypto_info);
756 	if (rc)
757 		goto free_rec_seq;
758 
759 	/* start at rec_seq - 1 to account for the start marker record */
760 	memcpy(&rcd_sn, ctx->tx.rec_seq, sizeof(rcd_sn));
761 	offload_ctx->unacked_record_sn = be64_to_cpu(rcd_sn) - 1;
762 
763 	start_marker_record->end_seq = tcp_sk(sk)->write_seq;
764 	start_marker_record->len = 0;
765 	start_marker_record->num_frags = 0;
766 
767 	INIT_LIST_HEAD(&offload_ctx->records_list);
768 	list_add_tail(&start_marker_record->list, &offload_ctx->records_list);
769 	spin_lock_init(&offload_ctx->lock);
770 	sg_init_table(offload_ctx->sg_tx_data,
771 		      ARRAY_SIZE(offload_ctx->sg_tx_data));
772 
773 	clean_acked_data_enable(inet_csk(sk), &tls_icsk_clean_acked);
774 	ctx->push_pending_record = tls_device_push_pending_record;
775 
776 	/* TLS offload is greatly simplified if we don't send
777 	 * SKBs where only part of the payload needs to be encrypted.
778 	 * So mark the last skb in the write queue as end of record.
779 	 */
780 	skb = tcp_write_queue_tail(sk);
781 	if (skb)
782 		TCP_SKB_CB(skb)->eor = 1;
783 
784 	/* We support starting offload on multiple sockets
785 	 * concurrently, so we only need a read lock here.
786 	 * This lock must precede get_netdev_for_sock to prevent races between
787 	 * NETDEV_DOWN and setsockopt.
788 	 */
789 	down_read(&device_offload_lock);
790 	netdev = get_netdev_for_sock(sk);
791 	if (!netdev) {
792 		pr_err_ratelimited("%s: netdev not found\n", __func__);
793 		rc = -EINVAL;
794 		goto release_lock;
795 	}
796 
797 	if (!(netdev->features & NETIF_F_HW_TLS_TX)) {
798 		rc = -ENOTSUPP;
799 		goto release_netdev;
800 	}
801 
802 	/* Avoid offloading if the device is down
803 	 * We don't want to offload new flows after
804 	 * the NETDEV_DOWN event
805 	 */
806 	if (!(netdev->flags & IFF_UP)) {
807 		rc = -EINVAL;
808 		goto release_netdev;
809 	}
810 
811 	ctx->priv_ctx_tx = offload_ctx;
812 	rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_TX,
813 					     &ctx->crypto_send.info,
814 					     tcp_sk(sk)->write_seq);
815 	if (rc)
816 		goto release_netdev;
817 
818 	tls_device_attach(ctx, sk, netdev);
819 
820 	/* following this assignment tls_is_sk_tx_device_offloaded
821 	 * will return true and the context might be accessed
822 	 * by the netdev's xmit function.
823 	 */
824 	smp_store_release(&sk->sk_validate_xmit_skb, tls_validate_xmit_skb);
825 	dev_put(netdev);
826 	up_read(&device_offload_lock);
827 	goto out;
828 
829 release_netdev:
830 	dev_put(netdev);
831 release_lock:
832 	up_read(&device_offload_lock);
833 	clean_acked_data_disable(inet_csk(sk));
834 	crypto_free_aead(offload_ctx->aead_send);
835 free_rec_seq:
836 	kfree(ctx->tx.rec_seq);
837 free_iv:
838 	kfree(ctx->tx.iv);
839 free_offload_ctx:
840 	kfree(offload_ctx);
841 	ctx->priv_ctx_tx = NULL;
842 free_marker_record:
843 	kfree(start_marker_record);
844 out:
845 	return rc;
846 }
847 
848 int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
849 {
850 	struct tls_offload_context_rx *context;
851 	struct net_device *netdev;
852 	int rc = 0;
853 
854 	/* We support starting offload on multiple sockets
855 	 * concurrently, so we only need a read lock here.
856 	 * This lock must precede get_netdev_for_sock to prevent races between
857 	 * NETDEV_DOWN and setsockopt.
858 	 */
859 	down_read(&device_offload_lock);
860 	netdev = get_netdev_for_sock(sk);
861 	if (!netdev) {
862 		pr_err_ratelimited("%s: netdev not found\n", __func__);
863 		rc = -EINVAL;
864 		goto release_lock;
865 	}
866 
867 	if (!(netdev->features & NETIF_F_HW_TLS_RX)) {
868 		pr_err_ratelimited("%s: netdev %s with no TLS offload\n",
869 				   __func__, netdev->name);
870 		rc = -ENOTSUPP;
871 		goto release_netdev;
872 	}
873 
874 	/* Avoid offloading if the device is down
875 	 * We don't want to offload new flows after
876 	 * the NETDEV_DOWN event
877 	 */
878 	if (!(netdev->flags & IFF_UP)) {
879 		rc = -EINVAL;
880 		goto release_netdev;
881 	}
882 
883 	context = kzalloc(TLS_OFFLOAD_CONTEXT_SIZE_RX, GFP_KERNEL);
884 	if (!context) {
885 		rc = -ENOMEM;
886 		goto release_netdev;
887 	}
888 
889 	ctx->priv_ctx_rx = context;
890 	rc = tls_set_sw_offload(sk, ctx, 0);
891 	if (rc)
892 		goto release_ctx;
893 
894 	rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_RX,
895 					     &ctx->crypto_recv.info,
896 					     tcp_sk(sk)->copied_seq);
897 	if (rc) {
898 		pr_err_ratelimited("%s: The netdev has refused to offload this socket\n",
899 				   __func__);
900 		goto free_sw_resources;
901 	}
902 
903 	tls_device_attach(ctx, sk, netdev);
904 	goto release_netdev;
905 
906 free_sw_resources:
907 	tls_sw_free_resources_rx(sk);
908 release_ctx:
909 	ctx->priv_ctx_rx = NULL;
910 release_netdev:
911 	dev_put(netdev);
912 release_lock:
913 	up_read(&device_offload_lock);
914 	return rc;
915 }
916 
917 void tls_device_offload_cleanup_rx(struct sock *sk)
918 {
919 	struct tls_context *tls_ctx = tls_get_ctx(sk);
920 	struct net_device *netdev;
921 
922 	down_read(&device_offload_lock);
923 	netdev = tls_ctx->netdev;
924 	if (!netdev)
925 		goto out;
926 
927 	if (!(netdev->features & NETIF_F_HW_TLS_RX)) {
928 		pr_err_ratelimited("%s: device is missing NETIF_F_HW_TLS_RX cap\n",
929 				   __func__);
930 		goto out;
931 	}
932 
933 	netdev->tlsdev_ops->tls_dev_del(netdev, tls_ctx,
934 					TLS_OFFLOAD_CTX_DIR_RX);
935 
936 	if (tls_ctx->tx_conf != TLS_HW) {
937 		dev_put(netdev);
938 		tls_ctx->netdev = NULL;
939 	}
940 out:
941 	up_read(&device_offload_lock);
942 	kfree(tls_ctx->rx.rec_seq);
943 	kfree(tls_ctx->rx.iv);
944 	tls_sw_release_resources_rx(sk);
945 }
946 
947 static int tls_device_down(struct net_device *netdev)
948 {
949 	struct tls_context *ctx, *tmp;
950 	unsigned long flags;
951 	LIST_HEAD(list);
952 
953 	/* Request a write lock to block new offload attempts */
954 	down_write(&device_offload_lock);
955 
956 	spin_lock_irqsave(&tls_device_lock, flags);
957 	list_for_each_entry_safe(ctx, tmp, &tls_device_list, list) {
958 		if (ctx->netdev != netdev ||
959 		    !refcount_inc_not_zero(&ctx->refcount))
960 			continue;
961 
962 		list_move(&ctx->list, &list);
963 	}
964 	spin_unlock_irqrestore(&tls_device_lock, flags);
965 
966 	list_for_each_entry_safe(ctx, tmp, &list, list)	{
967 		if (ctx->tx_conf == TLS_HW)
968 			netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
969 							TLS_OFFLOAD_CTX_DIR_TX);
970 		if (ctx->rx_conf == TLS_HW)
971 			netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
972 							TLS_OFFLOAD_CTX_DIR_RX);
973 		ctx->netdev = NULL;
974 		dev_put(netdev);
975 		list_del_init(&ctx->list);
976 
977 		if (refcount_dec_and_test(&ctx->refcount))
978 			tls_device_free_ctx(ctx);
979 	}
980 
981 	up_write(&device_offload_lock);
982 
983 	flush_work(&tls_device_gc_work);
984 
985 	return NOTIFY_DONE;
986 }
987 
988 static int tls_dev_event(struct notifier_block *this, unsigned long event,
989 			 void *ptr)
990 {
991 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
992 
993 	if (!(dev->features & (NETIF_F_HW_TLS_RX | NETIF_F_HW_TLS_TX)))
994 		return NOTIFY_DONE;
995 
996 	switch (event) {
997 	case NETDEV_REGISTER:
998 	case NETDEV_FEAT_CHANGE:
999 		if ((dev->features & NETIF_F_HW_TLS_RX) &&
1000 		    !dev->tlsdev_ops->tls_dev_resync_rx)
1001 			return NOTIFY_BAD;
1002 
1003 		if  (dev->tlsdev_ops &&
1004 		     dev->tlsdev_ops->tls_dev_add &&
1005 		     dev->tlsdev_ops->tls_dev_del)
1006 			return NOTIFY_DONE;
1007 		else
1008 			return NOTIFY_BAD;
1009 	case NETDEV_DOWN:
1010 		return tls_device_down(dev);
1011 	}
1012 	return NOTIFY_DONE;
1013 }
1014 
1015 static struct notifier_block tls_dev_notifier = {
1016 	.notifier_call	= tls_dev_event,
1017 };
1018 
1019 void __init tls_device_init(void)
1020 {
1021 	register_netdevice_notifier(&tls_dev_notifier);
1022 }
1023 
1024 void __exit tls_device_cleanup(void)
1025 {
1026 	unregister_netdevice_notifier(&tls_dev_notifier);
1027 	flush_work(&tls_device_gc_work);
1028 }
1029