xref: /openbmc/linux/net/tls/tls_main.c (revision 0c874100)
1 /*
2  * Copyright (c) 2016-2017, Mellanox Technologies. All rights reserved.
3  * Copyright (c) 2016-2017, Dave Watson <davejwatson@fb.com>. All rights reserved.
4  *
5  * This software is available to you under a choice of one of two
6  * licenses.  You may choose to be licensed under the terms of the GNU
7  * General Public License (GPL) Version 2, available from the file
8  * COPYING in the main directory of this source tree, or the
9  * OpenIB.org BSD license below:
10  *
11  *     Redistribution and use in source and binary forms, with or
12  *     without modification, are permitted provided that the following
13  *     conditions are met:
14  *
15  *      - Redistributions of source code must retain the above
16  *        copyright notice, this list of conditions and the following
17  *        disclaimer.
18  *
19  *      - Redistributions in binary form must reproduce the above
20  *        copyright notice, this list of conditions and the following
21  *        disclaimer in the documentation and/or other materials
22  *        provided with the distribution.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31  * SOFTWARE.
32  */
33 
34 #include <linux/module.h>
35 
36 #include <net/tcp.h>
37 #include <net/inet_common.h>
38 #include <linux/highmem.h>
39 #include <linux/netdevice.h>
40 #include <linux/sched/signal.h>
41 #include <linux/inetdevice.h>
42 
43 #include <net/tls.h>
44 
45 MODULE_AUTHOR("Mellanox Technologies");
46 MODULE_DESCRIPTION("Transport Layer Security Support");
47 MODULE_LICENSE("Dual BSD/GPL");
48 MODULE_ALIAS_TCP_ULP("tls");
49 
50 enum {
51 	TLSV4,
52 	TLSV6,
53 	TLS_NUM_PROTS,
54 };
55 
56 static struct proto *saved_tcpv6_prot;
57 static DEFINE_MUTEX(tcpv6_prot_mutex);
58 static LIST_HEAD(device_list);
59 static DEFINE_MUTEX(device_mutex);
60 static struct proto tls_prots[TLS_NUM_PROTS][TLS_NUM_CONFIG][TLS_NUM_CONFIG];
61 static struct proto_ops tls_sw_proto_ops;
62 
63 static void update_sk_prot(struct sock *sk, struct tls_context *ctx)
64 {
65 	int ip_ver = sk->sk_family == AF_INET6 ? TLSV6 : TLSV4;
66 
67 	sk->sk_prot = &tls_prots[ip_ver][ctx->tx_conf][ctx->rx_conf];
68 }
69 
70 int wait_on_pending_writer(struct sock *sk, long *timeo)
71 {
72 	int rc = 0;
73 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
74 
75 	add_wait_queue(sk_sleep(sk), &wait);
76 	while (1) {
77 		if (!*timeo) {
78 			rc = -EAGAIN;
79 			break;
80 		}
81 
82 		if (signal_pending(current)) {
83 			rc = sock_intr_errno(*timeo);
84 			break;
85 		}
86 
87 		if (sk_wait_event(sk, timeo, !sk->sk_write_pending, &wait))
88 			break;
89 	}
90 	remove_wait_queue(sk_sleep(sk), &wait);
91 	return rc;
92 }
93 
94 int tls_push_sg(struct sock *sk,
95 		struct tls_context *ctx,
96 		struct scatterlist *sg,
97 		u16 first_offset,
98 		int flags)
99 {
100 	int sendpage_flags = flags | MSG_SENDPAGE_NOTLAST;
101 	int ret = 0;
102 	struct page *p;
103 	size_t size;
104 	int offset = first_offset;
105 
106 	size = sg->length - offset;
107 	offset += sg->offset;
108 
109 	ctx->in_tcp_sendpages = true;
110 	while (1) {
111 		if (sg_is_last(sg))
112 			sendpage_flags = flags;
113 
114 		/* is sending application-limited? */
115 		tcp_rate_check_app_limited(sk);
116 		p = sg_page(sg);
117 retry:
118 		ret = do_tcp_sendpages(sk, p, offset, size, sendpage_flags);
119 
120 		if (ret != size) {
121 			if (ret > 0) {
122 				offset += ret;
123 				size -= ret;
124 				goto retry;
125 			}
126 
127 			offset -= sg->offset;
128 			ctx->partially_sent_offset = offset;
129 			ctx->partially_sent_record = (void *)sg;
130 			ctx->in_tcp_sendpages = false;
131 			return ret;
132 		}
133 
134 		put_page(p);
135 		sk_mem_uncharge(sk, sg->length);
136 		sg = sg_next(sg);
137 		if (!sg)
138 			break;
139 
140 		offset = sg->offset;
141 		size = sg->length;
142 	}
143 
144 	ctx->in_tcp_sendpages = false;
145 	ctx->sk_write_space(sk);
146 
147 	return 0;
148 }
149 
150 static int tls_handle_open_record(struct sock *sk, int flags)
151 {
152 	struct tls_context *ctx = tls_get_ctx(sk);
153 
154 	if (tls_is_pending_open_record(ctx))
155 		return ctx->push_pending_record(sk, flags);
156 
157 	return 0;
158 }
159 
160 int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
161 		      unsigned char *record_type)
162 {
163 	struct cmsghdr *cmsg;
164 	int rc = -EINVAL;
165 
166 	for_each_cmsghdr(cmsg, msg) {
167 		if (!CMSG_OK(msg, cmsg))
168 			return -EINVAL;
169 		if (cmsg->cmsg_level != SOL_TLS)
170 			continue;
171 
172 		switch (cmsg->cmsg_type) {
173 		case TLS_SET_RECORD_TYPE:
174 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(*record_type)))
175 				return -EINVAL;
176 
177 			if (msg->msg_flags & MSG_MORE)
178 				return -EINVAL;
179 
180 			rc = tls_handle_open_record(sk, msg->msg_flags);
181 			if (rc)
182 				return rc;
183 
184 			*record_type = *(unsigned char *)CMSG_DATA(cmsg);
185 			rc = 0;
186 			break;
187 		default:
188 			return -EINVAL;
189 		}
190 	}
191 
192 	return rc;
193 }
194 
195 int tls_push_partial_record(struct sock *sk, struct tls_context *ctx,
196 			    int flags)
197 {
198 	struct scatterlist *sg;
199 	u16 offset;
200 
201 	sg = ctx->partially_sent_record;
202 	offset = ctx->partially_sent_offset;
203 
204 	ctx->partially_sent_record = NULL;
205 	return tls_push_sg(sk, ctx, sg, offset, flags);
206 }
207 
208 int tls_push_pending_closed_record(struct sock *sk,
209 				   struct tls_context *tls_ctx,
210 				   int flags, long *timeo)
211 {
212 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
213 
214 	if (tls_is_partially_sent_record(tls_ctx) ||
215 	    !list_empty(&ctx->tx_list))
216 		return tls_tx_records(sk, flags);
217 	else
218 		return tls_ctx->push_pending_record(sk, flags);
219 }
220 
221 static void tls_write_space(struct sock *sk)
222 {
223 	struct tls_context *ctx = tls_get_ctx(sk);
224 	struct tls_sw_context_tx *tx_ctx = tls_sw_ctx_tx(ctx);
225 
226 	/* If in_tcp_sendpages call lower protocol write space handler
227 	 * to ensure we wake up any waiting operations there. For example
228 	 * if do_tcp_sendpages where to call sk_wait_event.
229 	 */
230 	if (ctx->in_tcp_sendpages) {
231 		ctx->sk_write_space(sk);
232 		return;
233 	}
234 
235 	/* Schedule the transmission if tx list is ready */
236 	if (is_tx_ready(tx_ctx) && !sk->sk_write_pending) {
237 		/* Schedule the transmission */
238 		if (!test_and_set_bit(BIT_TX_SCHEDULED, &tx_ctx->tx_bitmask))
239 			schedule_delayed_work(&tx_ctx->tx_work.work, 0);
240 	}
241 
242 	ctx->sk_write_space(sk);
243 }
244 
245 static void tls_ctx_free(struct tls_context *ctx)
246 {
247 	if (!ctx)
248 		return;
249 
250 	memzero_explicit(&ctx->crypto_send, sizeof(ctx->crypto_send));
251 	memzero_explicit(&ctx->crypto_recv, sizeof(ctx->crypto_recv));
252 	kfree(ctx);
253 }
254 
255 static void tls_sk_proto_close(struct sock *sk, long timeout)
256 {
257 	struct tls_context *ctx = tls_get_ctx(sk);
258 	long timeo = sock_sndtimeo(sk, 0);
259 	void (*sk_proto_close)(struct sock *sk, long timeout);
260 	bool free_ctx = false;
261 
262 	lock_sock(sk);
263 	sk_proto_close = ctx->sk_proto_close;
264 
265 	if ((ctx->tx_conf == TLS_HW_RECORD && ctx->rx_conf == TLS_HW_RECORD) ||
266 	    (ctx->tx_conf == TLS_BASE && ctx->rx_conf == TLS_BASE)) {
267 		free_ctx = true;
268 		goto skip_tx_cleanup;
269 	}
270 
271 	if (!tls_complete_pending_work(sk, ctx, 0, &timeo))
272 		tls_handle_open_record(sk, 0);
273 
274 	/* We need these for tls_sw_fallback handling of other packets */
275 	if (ctx->tx_conf == TLS_SW) {
276 		kfree(ctx->tx.rec_seq);
277 		kfree(ctx->tx.iv);
278 		tls_sw_free_resources_tx(sk);
279 	}
280 
281 	if (ctx->rx_conf == TLS_SW) {
282 		kfree(ctx->rx.rec_seq);
283 		kfree(ctx->rx.iv);
284 		tls_sw_free_resources_rx(sk);
285 	}
286 
287 #ifdef CONFIG_TLS_DEVICE
288 	if (ctx->rx_conf == TLS_HW)
289 		tls_device_offload_cleanup_rx(sk);
290 
291 	if (ctx->tx_conf != TLS_HW && ctx->rx_conf != TLS_HW) {
292 #else
293 	{
294 #endif
295 		tls_ctx_free(ctx);
296 		ctx = NULL;
297 	}
298 
299 skip_tx_cleanup:
300 	release_sock(sk);
301 	sk_proto_close(sk, timeout);
302 	/* free ctx for TLS_HW_RECORD, used by tcp_set_state
303 	 * for sk->sk_prot->unhash [tls_hw_unhash]
304 	 */
305 	if (free_ctx)
306 		tls_ctx_free(ctx);
307 }
308 
309 static int do_tls_getsockopt_tx(struct sock *sk, char __user *optval,
310 				int __user *optlen)
311 {
312 	int rc = 0;
313 	struct tls_context *ctx = tls_get_ctx(sk);
314 	struct tls_crypto_info *crypto_info;
315 	int len;
316 
317 	if (get_user(len, optlen))
318 		return -EFAULT;
319 
320 	if (!optval || (len < sizeof(*crypto_info))) {
321 		rc = -EINVAL;
322 		goto out;
323 	}
324 
325 	if (!ctx) {
326 		rc = -EBUSY;
327 		goto out;
328 	}
329 
330 	/* get user crypto info */
331 	crypto_info = &ctx->crypto_send.info;
332 
333 	if (!TLS_CRYPTO_INFO_READY(crypto_info)) {
334 		rc = -EBUSY;
335 		goto out;
336 	}
337 
338 	if (len == sizeof(*crypto_info)) {
339 		if (copy_to_user(optval, crypto_info, sizeof(*crypto_info)))
340 			rc = -EFAULT;
341 		goto out;
342 	}
343 
344 	switch (crypto_info->cipher_type) {
345 	case TLS_CIPHER_AES_GCM_128: {
346 		struct tls12_crypto_info_aes_gcm_128 *
347 		  crypto_info_aes_gcm_128 =
348 		  container_of(crypto_info,
349 			       struct tls12_crypto_info_aes_gcm_128,
350 			       info);
351 
352 		if (len != sizeof(*crypto_info_aes_gcm_128)) {
353 			rc = -EINVAL;
354 			goto out;
355 		}
356 		lock_sock(sk);
357 		memcpy(crypto_info_aes_gcm_128->iv,
358 		       ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
359 		       TLS_CIPHER_AES_GCM_128_IV_SIZE);
360 		memcpy(crypto_info_aes_gcm_128->rec_seq, ctx->tx.rec_seq,
361 		       TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE);
362 		release_sock(sk);
363 		if (copy_to_user(optval,
364 				 crypto_info_aes_gcm_128,
365 				 sizeof(*crypto_info_aes_gcm_128)))
366 			rc = -EFAULT;
367 		break;
368 	}
369 	default:
370 		rc = -EINVAL;
371 	}
372 
373 out:
374 	return rc;
375 }
376 
377 static int do_tls_getsockopt(struct sock *sk, int optname,
378 			     char __user *optval, int __user *optlen)
379 {
380 	int rc = 0;
381 
382 	switch (optname) {
383 	case TLS_TX:
384 		rc = do_tls_getsockopt_tx(sk, optval, optlen);
385 		break;
386 	default:
387 		rc = -ENOPROTOOPT;
388 		break;
389 	}
390 	return rc;
391 }
392 
393 static int tls_getsockopt(struct sock *sk, int level, int optname,
394 			  char __user *optval, int __user *optlen)
395 {
396 	struct tls_context *ctx = tls_get_ctx(sk);
397 
398 	if (level != SOL_TLS)
399 		return ctx->getsockopt(sk, level, optname, optval, optlen);
400 
401 	return do_tls_getsockopt(sk, optname, optval, optlen);
402 }
403 
404 static int do_tls_setsockopt_conf(struct sock *sk, char __user *optval,
405 				  unsigned int optlen, int tx)
406 {
407 	struct tls_crypto_info *crypto_info;
408 	struct tls_context *ctx = tls_get_ctx(sk);
409 	int rc = 0;
410 	int conf;
411 
412 	if (!optval || (optlen < sizeof(*crypto_info))) {
413 		rc = -EINVAL;
414 		goto out;
415 	}
416 
417 	if (tx)
418 		crypto_info = &ctx->crypto_send.info;
419 	else
420 		crypto_info = &ctx->crypto_recv.info;
421 
422 	/* Currently we don't support set crypto info more than one time */
423 	if (TLS_CRYPTO_INFO_READY(crypto_info)) {
424 		rc = -EBUSY;
425 		goto out;
426 	}
427 
428 	rc = copy_from_user(crypto_info, optval, sizeof(*crypto_info));
429 	if (rc) {
430 		rc = -EFAULT;
431 		goto err_crypto_info;
432 	}
433 
434 	/* check version */
435 	if (crypto_info->version != TLS_1_2_VERSION) {
436 		rc = -ENOTSUPP;
437 		goto err_crypto_info;
438 	}
439 
440 	switch (crypto_info->cipher_type) {
441 	case TLS_CIPHER_AES_GCM_128: {
442 		if (optlen != sizeof(struct tls12_crypto_info_aes_gcm_128)) {
443 			rc = -EINVAL;
444 			goto err_crypto_info;
445 		}
446 		rc = copy_from_user(crypto_info + 1, optval + sizeof(*crypto_info),
447 				    optlen - sizeof(*crypto_info));
448 		if (rc) {
449 			rc = -EFAULT;
450 			goto err_crypto_info;
451 		}
452 		break;
453 	}
454 	default:
455 		rc = -EINVAL;
456 		goto err_crypto_info;
457 	}
458 
459 	if (tx) {
460 #ifdef CONFIG_TLS_DEVICE
461 		rc = tls_set_device_offload(sk, ctx);
462 		conf = TLS_HW;
463 		if (rc) {
464 #else
465 		{
466 #endif
467 			rc = tls_set_sw_offload(sk, ctx, 1);
468 			conf = TLS_SW;
469 		}
470 	} else {
471 #ifdef CONFIG_TLS_DEVICE
472 		rc = tls_set_device_offload_rx(sk, ctx);
473 		conf = TLS_HW;
474 		if (rc) {
475 #else
476 		{
477 #endif
478 			rc = tls_set_sw_offload(sk, ctx, 0);
479 			conf = TLS_SW;
480 		}
481 	}
482 
483 	if (rc)
484 		goto err_crypto_info;
485 
486 	if (tx)
487 		ctx->tx_conf = conf;
488 	else
489 		ctx->rx_conf = conf;
490 	update_sk_prot(sk, ctx);
491 	if (tx) {
492 		ctx->sk_write_space = sk->sk_write_space;
493 		sk->sk_write_space = tls_write_space;
494 	} else {
495 		sk->sk_socket->ops = &tls_sw_proto_ops;
496 	}
497 	goto out;
498 
499 err_crypto_info:
500 	memzero_explicit(crypto_info, sizeof(union tls_crypto_context));
501 out:
502 	return rc;
503 }
504 
505 static int do_tls_setsockopt(struct sock *sk, int optname,
506 			     char __user *optval, unsigned int optlen)
507 {
508 	int rc = 0;
509 
510 	switch (optname) {
511 	case TLS_TX:
512 	case TLS_RX:
513 		lock_sock(sk);
514 		rc = do_tls_setsockopt_conf(sk, optval, optlen,
515 					    optname == TLS_TX);
516 		release_sock(sk);
517 		break;
518 	default:
519 		rc = -ENOPROTOOPT;
520 		break;
521 	}
522 	return rc;
523 }
524 
525 static int tls_setsockopt(struct sock *sk, int level, int optname,
526 			  char __user *optval, unsigned int optlen)
527 {
528 	struct tls_context *ctx = tls_get_ctx(sk);
529 
530 	if (level != SOL_TLS)
531 		return ctx->setsockopt(sk, level, optname, optval, optlen);
532 
533 	return do_tls_setsockopt(sk, optname, optval, optlen);
534 }
535 
536 static struct tls_context *create_ctx(struct sock *sk)
537 {
538 	struct inet_connection_sock *icsk = inet_csk(sk);
539 	struct tls_context *ctx;
540 
541 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
542 	if (!ctx)
543 		return NULL;
544 
545 	icsk->icsk_ulp_data = ctx;
546 	return ctx;
547 }
548 
549 static int tls_hw_prot(struct sock *sk)
550 {
551 	struct tls_context *ctx;
552 	struct tls_device *dev;
553 	int rc = 0;
554 
555 	mutex_lock(&device_mutex);
556 	list_for_each_entry(dev, &device_list, dev_list) {
557 		if (dev->feature && dev->feature(dev)) {
558 			ctx = create_ctx(sk);
559 			if (!ctx)
560 				goto out;
561 
562 			ctx->hash = sk->sk_prot->hash;
563 			ctx->unhash = sk->sk_prot->unhash;
564 			ctx->sk_proto_close = sk->sk_prot->close;
565 			ctx->rx_conf = TLS_HW_RECORD;
566 			ctx->tx_conf = TLS_HW_RECORD;
567 			update_sk_prot(sk, ctx);
568 			rc = 1;
569 			break;
570 		}
571 	}
572 out:
573 	mutex_unlock(&device_mutex);
574 	return rc;
575 }
576 
577 static void tls_hw_unhash(struct sock *sk)
578 {
579 	struct tls_context *ctx = tls_get_ctx(sk);
580 	struct tls_device *dev;
581 
582 	mutex_lock(&device_mutex);
583 	list_for_each_entry(dev, &device_list, dev_list) {
584 		if (dev->unhash)
585 			dev->unhash(dev, sk);
586 	}
587 	mutex_unlock(&device_mutex);
588 	ctx->unhash(sk);
589 }
590 
591 static int tls_hw_hash(struct sock *sk)
592 {
593 	struct tls_context *ctx = tls_get_ctx(sk);
594 	struct tls_device *dev;
595 	int err;
596 
597 	err = ctx->hash(sk);
598 	mutex_lock(&device_mutex);
599 	list_for_each_entry(dev, &device_list, dev_list) {
600 		if (dev->hash)
601 			err |= dev->hash(dev, sk);
602 	}
603 	mutex_unlock(&device_mutex);
604 
605 	if (err)
606 		tls_hw_unhash(sk);
607 	return err;
608 }
609 
610 static void build_protos(struct proto prot[TLS_NUM_CONFIG][TLS_NUM_CONFIG],
611 			 struct proto *base)
612 {
613 	prot[TLS_BASE][TLS_BASE] = *base;
614 	prot[TLS_BASE][TLS_BASE].setsockopt	= tls_setsockopt;
615 	prot[TLS_BASE][TLS_BASE].getsockopt	= tls_getsockopt;
616 	prot[TLS_BASE][TLS_BASE].close		= tls_sk_proto_close;
617 
618 	prot[TLS_SW][TLS_BASE] = prot[TLS_BASE][TLS_BASE];
619 	prot[TLS_SW][TLS_BASE].sendmsg		= tls_sw_sendmsg;
620 	prot[TLS_SW][TLS_BASE].sendpage		= tls_sw_sendpage;
621 
622 	prot[TLS_BASE][TLS_SW] = prot[TLS_BASE][TLS_BASE];
623 	prot[TLS_BASE][TLS_SW].recvmsg		  = tls_sw_recvmsg;
624 	prot[TLS_BASE][TLS_SW].stream_memory_read = tls_sw_stream_read;
625 	prot[TLS_BASE][TLS_SW].close		  = tls_sk_proto_close;
626 
627 	prot[TLS_SW][TLS_SW] = prot[TLS_SW][TLS_BASE];
628 	prot[TLS_SW][TLS_SW].recvmsg		= tls_sw_recvmsg;
629 	prot[TLS_SW][TLS_SW].stream_memory_read	= tls_sw_stream_read;
630 	prot[TLS_SW][TLS_SW].close		= tls_sk_proto_close;
631 
632 #ifdef CONFIG_TLS_DEVICE
633 	prot[TLS_HW][TLS_BASE] = prot[TLS_BASE][TLS_BASE];
634 	prot[TLS_HW][TLS_BASE].sendmsg		= tls_device_sendmsg;
635 	prot[TLS_HW][TLS_BASE].sendpage		= tls_device_sendpage;
636 
637 	prot[TLS_HW][TLS_SW] = prot[TLS_BASE][TLS_SW];
638 	prot[TLS_HW][TLS_SW].sendmsg		= tls_device_sendmsg;
639 	prot[TLS_HW][TLS_SW].sendpage		= tls_device_sendpage;
640 
641 	prot[TLS_BASE][TLS_HW] = prot[TLS_BASE][TLS_SW];
642 
643 	prot[TLS_SW][TLS_HW] = prot[TLS_SW][TLS_SW];
644 
645 	prot[TLS_HW][TLS_HW] = prot[TLS_HW][TLS_SW];
646 #endif
647 
648 	prot[TLS_HW_RECORD][TLS_HW_RECORD] = *base;
649 	prot[TLS_HW_RECORD][TLS_HW_RECORD].hash		= tls_hw_hash;
650 	prot[TLS_HW_RECORD][TLS_HW_RECORD].unhash	= tls_hw_unhash;
651 	prot[TLS_HW_RECORD][TLS_HW_RECORD].close	= tls_sk_proto_close;
652 }
653 
654 static int tls_init(struct sock *sk)
655 {
656 	int ip_ver = sk->sk_family == AF_INET6 ? TLSV6 : TLSV4;
657 	struct tls_context *ctx;
658 	int rc = 0;
659 
660 	if (tls_hw_prot(sk))
661 		goto out;
662 
663 	/* The TLS ulp is currently supported only for TCP sockets
664 	 * in ESTABLISHED state.
665 	 * Supporting sockets in LISTEN state will require us
666 	 * to modify the accept implementation to clone rather then
667 	 * share the ulp context.
668 	 */
669 	if (sk->sk_state != TCP_ESTABLISHED)
670 		return -ENOTSUPP;
671 
672 	/* allocate tls context */
673 	ctx = create_ctx(sk);
674 	if (!ctx) {
675 		rc = -ENOMEM;
676 		goto out;
677 	}
678 	ctx->setsockopt = sk->sk_prot->setsockopt;
679 	ctx->getsockopt = sk->sk_prot->getsockopt;
680 	ctx->sk_proto_close = sk->sk_prot->close;
681 
682 	/* Build IPv6 TLS whenever the address of tcpv6	_prot changes */
683 	if (ip_ver == TLSV6 &&
684 	    unlikely(sk->sk_prot != smp_load_acquire(&saved_tcpv6_prot))) {
685 		mutex_lock(&tcpv6_prot_mutex);
686 		if (likely(sk->sk_prot != saved_tcpv6_prot)) {
687 			build_protos(tls_prots[TLSV6], sk->sk_prot);
688 			smp_store_release(&saved_tcpv6_prot, sk->sk_prot);
689 		}
690 		mutex_unlock(&tcpv6_prot_mutex);
691 	}
692 
693 	ctx->tx_conf = TLS_BASE;
694 	ctx->rx_conf = TLS_BASE;
695 	update_sk_prot(sk, ctx);
696 out:
697 	return rc;
698 }
699 
700 void tls_register_device(struct tls_device *device)
701 {
702 	mutex_lock(&device_mutex);
703 	list_add_tail(&device->dev_list, &device_list);
704 	mutex_unlock(&device_mutex);
705 }
706 EXPORT_SYMBOL(tls_register_device);
707 
708 void tls_unregister_device(struct tls_device *device)
709 {
710 	mutex_lock(&device_mutex);
711 	list_del(&device->dev_list);
712 	mutex_unlock(&device_mutex);
713 }
714 EXPORT_SYMBOL(tls_unregister_device);
715 
716 static struct tcp_ulp_ops tcp_tls_ulp_ops __read_mostly = {
717 	.name			= "tls",
718 	.owner			= THIS_MODULE,
719 	.init			= tls_init,
720 };
721 
722 static int __init tls_register(void)
723 {
724 	build_protos(tls_prots[TLSV4], &tcp_prot);
725 
726 	tls_sw_proto_ops = inet_stream_ops;
727 	tls_sw_proto_ops.splice_read = tls_sw_splice_read;
728 
729 #ifdef CONFIG_TLS_DEVICE
730 	tls_device_init();
731 #endif
732 	tcp_register_ulp(&tcp_tls_ulp_ops);
733 
734 	return 0;
735 }
736 
737 static void __exit tls_unregister(void)
738 {
739 	tcp_unregister_ulp(&tcp_tls_ulp_ops);
740 #ifdef CONFIG_TLS_DEVICE
741 	tls_device_cleanup();
742 #endif
743 }
744 
745 module_init(tls_register);
746 module_exit(tls_unregister);
747