xref: /openbmc/linux/net/tls/tls_main.c (revision 15e3ae36)
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 #include <linux/inet_diag.h>
43 
44 #include <net/snmp.h>
45 #include <net/tls.h>
46 #include <net/tls_toe.h>
47 
48 MODULE_AUTHOR("Mellanox Technologies");
49 MODULE_DESCRIPTION("Transport Layer Security Support");
50 MODULE_LICENSE("Dual BSD/GPL");
51 MODULE_ALIAS_TCP_ULP("tls");
52 
53 enum {
54 	TLSV4,
55 	TLSV6,
56 	TLS_NUM_PROTS,
57 };
58 
59 static struct proto *saved_tcpv6_prot;
60 static DEFINE_MUTEX(tcpv6_prot_mutex);
61 static struct proto *saved_tcpv4_prot;
62 static DEFINE_MUTEX(tcpv4_prot_mutex);
63 static struct proto tls_prots[TLS_NUM_PROTS][TLS_NUM_CONFIG][TLS_NUM_CONFIG];
64 static struct proto_ops tls_sw_proto_ops;
65 static void build_protos(struct proto prot[TLS_NUM_CONFIG][TLS_NUM_CONFIG],
66 			 const struct proto *base);
67 
68 void update_sk_prot(struct sock *sk, struct tls_context *ctx)
69 {
70 	int ip_ver = sk->sk_family == AF_INET6 ? TLSV6 : TLSV4;
71 
72 	WRITE_ONCE(sk->sk_prot,
73 		   &tls_prots[ip_ver][ctx->tx_conf][ctx->rx_conf]);
74 }
75 
76 int wait_on_pending_writer(struct sock *sk, long *timeo)
77 {
78 	int rc = 0;
79 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
80 
81 	add_wait_queue(sk_sleep(sk), &wait);
82 	while (1) {
83 		if (!*timeo) {
84 			rc = -EAGAIN;
85 			break;
86 		}
87 
88 		if (signal_pending(current)) {
89 			rc = sock_intr_errno(*timeo);
90 			break;
91 		}
92 
93 		if (sk_wait_event(sk, timeo, !sk->sk_write_pending, &wait))
94 			break;
95 	}
96 	remove_wait_queue(sk_sleep(sk), &wait);
97 	return rc;
98 }
99 
100 int tls_push_sg(struct sock *sk,
101 		struct tls_context *ctx,
102 		struct scatterlist *sg,
103 		u16 first_offset,
104 		int flags)
105 {
106 	int sendpage_flags = flags | MSG_SENDPAGE_NOTLAST;
107 	int ret = 0;
108 	struct page *p;
109 	size_t size;
110 	int offset = first_offset;
111 
112 	size = sg->length - offset;
113 	offset += sg->offset;
114 
115 	ctx->in_tcp_sendpages = true;
116 	while (1) {
117 		if (sg_is_last(sg))
118 			sendpage_flags = flags;
119 
120 		/* is sending application-limited? */
121 		tcp_rate_check_app_limited(sk);
122 		p = sg_page(sg);
123 retry:
124 		ret = do_tcp_sendpages(sk, p, offset, size, sendpage_flags);
125 
126 		if (ret != size) {
127 			if (ret > 0) {
128 				offset += ret;
129 				size -= ret;
130 				goto retry;
131 			}
132 
133 			offset -= sg->offset;
134 			ctx->partially_sent_offset = offset;
135 			ctx->partially_sent_record = (void *)sg;
136 			ctx->in_tcp_sendpages = false;
137 			return ret;
138 		}
139 
140 		put_page(p);
141 		sk_mem_uncharge(sk, sg->length);
142 		sg = sg_next(sg);
143 		if (!sg)
144 			break;
145 
146 		offset = sg->offset;
147 		size = sg->length;
148 	}
149 
150 	ctx->in_tcp_sendpages = false;
151 
152 	return 0;
153 }
154 
155 static int tls_handle_open_record(struct sock *sk, int flags)
156 {
157 	struct tls_context *ctx = tls_get_ctx(sk);
158 
159 	if (tls_is_pending_open_record(ctx))
160 		return ctx->push_pending_record(sk, flags);
161 
162 	return 0;
163 }
164 
165 int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
166 		      unsigned char *record_type)
167 {
168 	struct cmsghdr *cmsg;
169 	int rc = -EINVAL;
170 
171 	for_each_cmsghdr(cmsg, msg) {
172 		if (!CMSG_OK(msg, cmsg))
173 			return -EINVAL;
174 		if (cmsg->cmsg_level != SOL_TLS)
175 			continue;
176 
177 		switch (cmsg->cmsg_type) {
178 		case TLS_SET_RECORD_TYPE:
179 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(*record_type)))
180 				return -EINVAL;
181 
182 			if (msg->msg_flags & MSG_MORE)
183 				return -EINVAL;
184 
185 			rc = tls_handle_open_record(sk, msg->msg_flags);
186 			if (rc)
187 				return rc;
188 
189 			*record_type = *(unsigned char *)CMSG_DATA(cmsg);
190 			rc = 0;
191 			break;
192 		default:
193 			return -EINVAL;
194 		}
195 	}
196 
197 	return rc;
198 }
199 
200 int tls_push_partial_record(struct sock *sk, struct tls_context *ctx,
201 			    int flags)
202 {
203 	struct scatterlist *sg;
204 	u16 offset;
205 
206 	sg = ctx->partially_sent_record;
207 	offset = ctx->partially_sent_offset;
208 
209 	ctx->partially_sent_record = NULL;
210 	return tls_push_sg(sk, ctx, sg, offset, flags);
211 }
212 
213 void tls_free_partial_record(struct sock *sk, struct tls_context *ctx)
214 {
215 	struct scatterlist *sg;
216 
217 	for (sg = ctx->partially_sent_record; sg; sg = sg_next(sg)) {
218 		put_page(sg_page(sg));
219 		sk_mem_uncharge(sk, sg->length);
220 	}
221 	ctx->partially_sent_record = NULL;
222 }
223 
224 static void tls_write_space(struct sock *sk)
225 {
226 	struct tls_context *ctx = tls_get_ctx(sk);
227 
228 	/* If in_tcp_sendpages call lower protocol write space handler
229 	 * to ensure we wake up any waiting operations there. For example
230 	 * if do_tcp_sendpages where to call sk_wait_event.
231 	 */
232 	if (ctx->in_tcp_sendpages) {
233 		ctx->sk_write_space(sk);
234 		return;
235 	}
236 
237 #ifdef CONFIG_TLS_DEVICE
238 	if (ctx->tx_conf == TLS_HW)
239 		tls_device_write_space(sk, ctx);
240 	else
241 #endif
242 		tls_sw_write_space(sk, ctx);
243 
244 	ctx->sk_write_space(sk);
245 }
246 
247 /**
248  * tls_ctx_free() - free TLS ULP context
249  * @sk:  socket to with @ctx is attached
250  * @ctx: TLS context structure
251  *
252  * Free TLS context. If @sk is %NULL caller guarantees that the socket
253  * to which @ctx was attached has no outstanding references.
254  */
255 void tls_ctx_free(struct sock *sk, struct tls_context *ctx)
256 {
257 	if (!ctx)
258 		return;
259 
260 	memzero_explicit(&ctx->crypto_send, sizeof(ctx->crypto_send));
261 	memzero_explicit(&ctx->crypto_recv, sizeof(ctx->crypto_recv));
262 	mutex_destroy(&ctx->tx_lock);
263 
264 	if (sk)
265 		kfree_rcu(ctx, rcu);
266 	else
267 		kfree(ctx);
268 }
269 
270 static void tls_sk_proto_cleanup(struct sock *sk,
271 				 struct tls_context *ctx, long timeo)
272 {
273 	if (unlikely(sk->sk_write_pending) &&
274 	    !wait_on_pending_writer(sk, &timeo))
275 		tls_handle_open_record(sk, 0);
276 
277 	/* We need these for tls_sw_fallback handling of other packets */
278 	if (ctx->tx_conf == TLS_SW) {
279 		kfree(ctx->tx.rec_seq);
280 		kfree(ctx->tx.iv);
281 		tls_sw_release_resources_tx(sk);
282 		TLS_DEC_STATS(sock_net(sk), LINUX_MIB_TLSCURRTXSW);
283 	} else if (ctx->tx_conf == TLS_HW) {
284 		tls_device_free_resources_tx(sk);
285 		TLS_DEC_STATS(sock_net(sk), LINUX_MIB_TLSCURRTXDEVICE);
286 	}
287 
288 	if (ctx->rx_conf == TLS_SW) {
289 		tls_sw_release_resources_rx(sk);
290 		TLS_DEC_STATS(sock_net(sk), LINUX_MIB_TLSCURRRXSW);
291 	} else if (ctx->rx_conf == TLS_HW) {
292 		tls_device_offload_cleanup_rx(sk);
293 		TLS_DEC_STATS(sock_net(sk), LINUX_MIB_TLSCURRRXDEVICE);
294 	}
295 }
296 
297 static void tls_sk_proto_close(struct sock *sk, long timeout)
298 {
299 	struct inet_connection_sock *icsk = inet_csk(sk);
300 	struct tls_context *ctx = tls_get_ctx(sk);
301 	long timeo = sock_sndtimeo(sk, 0);
302 	bool free_ctx;
303 
304 	if (ctx->tx_conf == TLS_SW)
305 		tls_sw_cancel_work_tx(ctx);
306 
307 	lock_sock(sk);
308 	free_ctx = ctx->tx_conf != TLS_HW && ctx->rx_conf != TLS_HW;
309 
310 	if (ctx->tx_conf != TLS_BASE || ctx->rx_conf != TLS_BASE)
311 		tls_sk_proto_cleanup(sk, ctx, timeo);
312 
313 	write_lock_bh(&sk->sk_callback_lock);
314 	if (free_ctx)
315 		rcu_assign_pointer(icsk->icsk_ulp_data, NULL);
316 	WRITE_ONCE(sk->sk_prot, ctx->sk_proto);
317 	if (sk->sk_write_space == tls_write_space)
318 		sk->sk_write_space = ctx->sk_write_space;
319 	write_unlock_bh(&sk->sk_callback_lock);
320 	release_sock(sk);
321 	if (ctx->tx_conf == TLS_SW)
322 		tls_sw_free_ctx_tx(ctx);
323 	if (ctx->rx_conf == TLS_SW || ctx->rx_conf == TLS_HW)
324 		tls_sw_strparser_done(ctx);
325 	if (ctx->rx_conf == TLS_SW)
326 		tls_sw_free_ctx_rx(ctx);
327 	ctx->sk_proto->close(sk, timeout);
328 
329 	if (free_ctx)
330 		tls_ctx_free(sk, ctx);
331 }
332 
333 static int do_tls_getsockopt_tx(struct sock *sk, char __user *optval,
334 				int __user *optlen)
335 {
336 	int rc = 0;
337 	struct tls_context *ctx = tls_get_ctx(sk);
338 	struct tls_crypto_info *crypto_info;
339 	int len;
340 
341 	if (get_user(len, optlen))
342 		return -EFAULT;
343 
344 	if (!optval || (len < sizeof(*crypto_info))) {
345 		rc = -EINVAL;
346 		goto out;
347 	}
348 
349 	if (!ctx) {
350 		rc = -EBUSY;
351 		goto out;
352 	}
353 
354 	/* get user crypto info */
355 	crypto_info = &ctx->crypto_send.info;
356 
357 	if (!TLS_CRYPTO_INFO_READY(crypto_info)) {
358 		rc = -EBUSY;
359 		goto out;
360 	}
361 
362 	if (len == sizeof(*crypto_info)) {
363 		if (copy_to_user(optval, crypto_info, sizeof(*crypto_info)))
364 			rc = -EFAULT;
365 		goto out;
366 	}
367 
368 	switch (crypto_info->cipher_type) {
369 	case TLS_CIPHER_AES_GCM_128: {
370 		struct tls12_crypto_info_aes_gcm_128 *
371 		  crypto_info_aes_gcm_128 =
372 		  container_of(crypto_info,
373 			       struct tls12_crypto_info_aes_gcm_128,
374 			       info);
375 
376 		if (len != sizeof(*crypto_info_aes_gcm_128)) {
377 			rc = -EINVAL;
378 			goto out;
379 		}
380 		lock_sock(sk);
381 		memcpy(crypto_info_aes_gcm_128->iv,
382 		       ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
383 		       TLS_CIPHER_AES_GCM_128_IV_SIZE);
384 		memcpy(crypto_info_aes_gcm_128->rec_seq, ctx->tx.rec_seq,
385 		       TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE);
386 		release_sock(sk);
387 		if (copy_to_user(optval,
388 				 crypto_info_aes_gcm_128,
389 				 sizeof(*crypto_info_aes_gcm_128)))
390 			rc = -EFAULT;
391 		break;
392 	}
393 	case TLS_CIPHER_AES_GCM_256: {
394 		struct tls12_crypto_info_aes_gcm_256 *
395 		  crypto_info_aes_gcm_256 =
396 		  container_of(crypto_info,
397 			       struct tls12_crypto_info_aes_gcm_256,
398 			       info);
399 
400 		if (len != sizeof(*crypto_info_aes_gcm_256)) {
401 			rc = -EINVAL;
402 			goto out;
403 		}
404 		lock_sock(sk);
405 		memcpy(crypto_info_aes_gcm_256->iv,
406 		       ctx->tx.iv + TLS_CIPHER_AES_GCM_256_SALT_SIZE,
407 		       TLS_CIPHER_AES_GCM_256_IV_SIZE);
408 		memcpy(crypto_info_aes_gcm_256->rec_seq, ctx->tx.rec_seq,
409 		       TLS_CIPHER_AES_GCM_256_REC_SEQ_SIZE);
410 		release_sock(sk);
411 		if (copy_to_user(optval,
412 				 crypto_info_aes_gcm_256,
413 				 sizeof(*crypto_info_aes_gcm_256)))
414 			rc = -EFAULT;
415 		break;
416 	}
417 	default:
418 		rc = -EINVAL;
419 	}
420 
421 out:
422 	return rc;
423 }
424 
425 static int do_tls_getsockopt(struct sock *sk, int optname,
426 			     char __user *optval, int __user *optlen)
427 {
428 	int rc = 0;
429 
430 	switch (optname) {
431 	case TLS_TX:
432 		rc = do_tls_getsockopt_tx(sk, optval, optlen);
433 		break;
434 	default:
435 		rc = -ENOPROTOOPT;
436 		break;
437 	}
438 	return rc;
439 }
440 
441 static int tls_getsockopt(struct sock *sk, int level, int optname,
442 			  char __user *optval, int __user *optlen)
443 {
444 	struct tls_context *ctx = tls_get_ctx(sk);
445 
446 	if (level != SOL_TLS)
447 		return ctx->sk_proto->getsockopt(sk, level,
448 						 optname, optval, optlen);
449 
450 	return do_tls_getsockopt(sk, optname, optval, optlen);
451 }
452 
453 static int do_tls_setsockopt_conf(struct sock *sk, char __user *optval,
454 				  unsigned int optlen, int tx)
455 {
456 	struct tls_crypto_info *crypto_info;
457 	struct tls_crypto_info *alt_crypto_info;
458 	struct tls_context *ctx = tls_get_ctx(sk);
459 	size_t optsize;
460 	int rc = 0;
461 	int conf;
462 
463 	if (!optval || (optlen < sizeof(*crypto_info))) {
464 		rc = -EINVAL;
465 		goto out;
466 	}
467 
468 	if (tx) {
469 		crypto_info = &ctx->crypto_send.info;
470 		alt_crypto_info = &ctx->crypto_recv.info;
471 	} else {
472 		crypto_info = &ctx->crypto_recv.info;
473 		alt_crypto_info = &ctx->crypto_send.info;
474 	}
475 
476 	/* Currently we don't support set crypto info more than one time */
477 	if (TLS_CRYPTO_INFO_READY(crypto_info)) {
478 		rc = -EBUSY;
479 		goto out;
480 	}
481 
482 	rc = copy_from_user(crypto_info, optval, sizeof(*crypto_info));
483 	if (rc) {
484 		rc = -EFAULT;
485 		goto err_crypto_info;
486 	}
487 
488 	/* check version */
489 	if (crypto_info->version != TLS_1_2_VERSION &&
490 	    crypto_info->version != TLS_1_3_VERSION) {
491 		rc = -EINVAL;
492 		goto err_crypto_info;
493 	}
494 
495 	/* Ensure that TLS version and ciphers are same in both directions */
496 	if (TLS_CRYPTO_INFO_READY(alt_crypto_info)) {
497 		if (alt_crypto_info->version != crypto_info->version ||
498 		    alt_crypto_info->cipher_type != crypto_info->cipher_type) {
499 			rc = -EINVAL;
500 			goto err_crypto_info;
501 		}
502 	}
503 
504 	switch (crypto_info->cipher_type) {
505 	case TLS_CIPHER_AES_GCM_128:
506 		optsize = sizeof(struct tls12_crypto_info_aes_gcm_128);
507 		break;
508 	case TLS_CIPHER_AES_GCM_256: {
509 		optsize = sizeof(struct tls12_crypto_info_aes_gcm_256);
510 		break;
511 	}
512 	case TLS_CIPHER_AES_CCM_128:
513 		optsize = sizeof(struct tls12_crypto_info_aes_ccm_128);
514 		break;
515 	default:
516 		rc = -EINVAL;
517 		goto err_crypto_info;
518 	}
519 
520 	if (optlen != optsize) {
521 		rc = -EINVAL;
522 		goto err_crypto_info;
523 	}
524 
525 	rc = copy_from_user(crypto_info + 1, optval + sizeof(*crypto_info),
526 			    optlen - sizeof(*crypto_info));
527 	if (rc) {
528 		rc = -EFAULT;
529 		goto err_crypto_info;
530 	}
531 
532 	if (tx) {
533 		rc = tls_set_device_offload(sk, ctx);
534 		conf = TLS_HW;
535 		if (!rc) {
536 			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSTXDEVICE);
537 			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSCURRTXDEVICE);
538 		} else {
539 			rc = tls_set_sw_offload(sk, ctx, 1);
540 			if (rc)
541 				goto err_crypto_info;
542 			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSTXSW);
543 			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSCURRTXSW);
544 			conf = TLS_SW;
545 		}
546 	} else {
547 		rc = tls_set_device_offload_rx(sk, ctx);
548 		conf = TLS_HW;
549 		if (!rc) {
550 			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSRXDEVICE);
551 			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSCURRRXDEVICE);
552 		} else {
553 			rc = tls_set_sw_offload(sk, ctx, 0);
554 			if (rc)
555 				goto err_crypto_info;
556 			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSRXSW);
557 			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSCURRRXSW);
558 			conf = TLS_SW;
559 		}
560 		tls_sw_strparser_arm(sk, ctx);
561 	}
562 
563 	if (tx)
564 		ctx->tx_conf = conf;
565 	else
566 		ctx->rx_conf = conf;
567 	update_sk_prot(sk, ctx);
568 	if (tx) {
569 		ctx->sk_write_space = sk->sk_write_space;
570 		sk->sk_write_space = tls_write_space;
571 	} else {
572 		sk->sk_socket->ops = &tls_sw_proto_ops;
573 	}
574 	goto out;
575 
576 err_crypto_info:
577 	memzero_explicit(crypto_info, sizeof(union tls_crypto_context));
578 out:
579 	return rc;
580 }
581 
582 static int do_tls_setsockopt(struct sock *sk, int optname,
583 			     char __user *optval, unsigned int optlen)
584 {
585 	int rc = 0;
586 
587 	switch (optname) {
588 	case TLS_TX:
589 	case TLS_RX:
590 		lock_sock(sk);
591 		rc = do_tls_setsockopt_conf(sk, optval, optlen,
592 					    optname == TLS_TX);
593 		release_sock(sk);
594 		break;
595 	default:
596 		rc = -ENOPROTOOPT;
597 		break;
598 	}
599 	return rc;
600 }
601 
602 static int tls_setsockopt(struct sock *sk, int level, int optname,
603 			  char __user *optval, unsigned int optlen)
604 {
605 	struct tls_context *ctx = tls_get_ctx(sk);
606 
607 	if (level != SOL_TLS)
608 		return ctx->sk_proto->setsockopt(sk, level, optname, optval,
609 						 optlen);
610 
611 	return do_tls_setsockopt(sk, optname, optval, optlen);
612 }
613 
614 struct tls_context *tls_ctx_create(struct sock *sk)
615 {
616 	struct inet_connection_sock *icsk = inet_csk(sk);
617 	struct tls_context *ctx;
618 
619 	ctx = kzalloc(sizeof(*ctx), GFP_ATOMIC);
620 	if (!ctx)
621 		return NULL;
622 
623 	mutex_init(&ctx->tx_lock);
624 	rcu_assign_pointer(icsk->icsk_ulp_data, ctx);
625 	ctx->sk_proto = READ_ONCE(sk->sk_prot);
626 	return ctx;
627 }
628 
629 static void tls_build_proto(struct sock *sk)
630 {
631 	int ip_ver = sk->sk_family == AF_INET6 ? TLSV6 : TLSV4;
632 	const struct proto *prot = READ_ONCE(sk->sk_prot);
633 
634 	/* Build IPv6 TLS whenever the address of tcpv6 _prot changes */
635 	if (ip_ver == TLSV6 &&
636 	    unlikely(prot != smp_load_acquire(&saved_tcpv6_prot))) {
637 		mutex_lock(&tcpv6_prot_mutex);
638 		if (likely(prot != saved_tcpv6_prot)) {
639 			build_protos(tls_prots[TLSV6], prot);
640 			smp_store_release(&saved_tcpv6_prot, prot);
641 		}
642 		mutex_unlock(&tcpv6_prot_mutex);
643 	}
644 
645 	if (ip_ver == TLSV4 &&
646 	    unlikely(prot != smp_load_acquire(&saved_tcpv4_prot))) {
647 		mutex_lock(&tcpv4_prot_mutex);
648 		if (likely(prot != saved_tcpv4_prot)) {
649 			build_protos(tls_prots[TLSV4], prot);
650 			smp_store_release(&saved_tcpv4_prot, prot);
651 		}
652 		mutex_unlock(&tcpv4_prot_mutex);
653 	}
654 }
655 
656 static void build_protos(struct proto prot[TLS_NUM_CONFIG][TLS_NUM_CONFIG],
657 			 const struct proto *base)
658 {
659 	prot[TLS_BASE][TLS_BASE] = *base;
660 	prot[TLS_BASE][TLS_BASE].setsockopt	= tls_setsockopt;
661 	prot[TLS_BASE][TLS_BASE].getsockopt	= tls_getsockopt;
662 	prot[TLS_BASE][TLS_BASE].close		= tls_sk_proto_close;
663 
664 	prot[TLS_SW][TLS_BASE] = prot[TLS_BASE][TLS_BASE];
665 	prot[TLS_SW][TLS_BASE].sendmsg		= tls_sw_sendmsg;
666 	prot[TLS_SW][TLS_BASE].sendpage		= tls_sw_sendpage;
667 
668 	prot[TLS_BASE][TLS_SW] = prot[TLS_BASE][TLS_BASE];
669 	prot[TLS_BASE][TLS_SW].recvmsg		  = tls_sw_recvmsg;
670 	prot[TLS_BASE][TLS_SW].stream_memory_read = tls_sw_stream_read;
671 	prot[TLS_BASE][TLS_SW].close		  = tls_sk_proto_close;
672 
673 	prot[TLS_SW][TLS_SW] = prot[TLS_SW][TLS_BASE];
674 	prot[TLS_SW][TLS_SW].recvmsg		= tls_sw_recvmsg;
675 	prot[TLS_SW][TLS_SW].stream_memory_read	= tls_sw_stream_read;
676 	prot[TLS_SW][TLS_SW].close		= tls_sk_proto_close;
677 
678 #ifdef CONFIG_TLS_DEVICE
679 	prot[TLS_HW][TLS_BASE] = prot[TLS_BASE][TLS_BASE];
680 	prot[TLS_HW][TLS_BASE].sendmsg		= tls_device_sendmsg;
681 	prot[TLS_HW][TLS_BASE].sendpage		= tls_device_sendpage;
682 
683 	prot[TLS_HW][TLS_SW] = prot[TLS_BASE][TLS_SW];
684 	prot[TLS_HW][TLS_SW].sendmsg		= tls_device_sendmsg;
685 	prot[TLS_HW][TLS_SW].sendpage		= tls_device_sendpage;
686 
687 	prot[TLS_BASE][TLS_HW] = prot[TLS_BASE][TLS_SW];
688 
689 	prot[TLS_SW][TLS_HW] = prot[TLS_SW][TLS_SW];
690 
691 	prot[TLS_HW][TLS_HW] = prot[TLS_HW][TLS_SW];
692 #endif
693 #ifdef CONFIG_TLS_TOE
694 	prot[TLS_HW_RECORD][TLS_HW_RECORD] = *base;
695 	prot[TLS_HW_RECORD][TLS_HW_RECORD].hash		= tls_toe_hash;
696 	prot[TLS_HW_RECORD][TLS_HW_RECORD].unhash	= tls_toe_unhash;
697 #endif
698 }
699 
700 static int tls_init(struct sock *sk)
701 {
702 	struct tls_context *ctx;
703 	int rc = 0;
704 
705 	tls_build_proto(sk);
706 
707 #ifdef CONFIG_TLS_TOE
708 	if (tls_toe_bypass(sk))
709 		return 0;
710 #endif
711 
712 	/* The TLS ulp is currently supported only for TCP sockets
713 	 * in ESTABLISHED state.
714 	 * Supporting sockets in LISTEN state will require us
715 	 * to modify the accept implementation to clone rather then
716 	 * share the ulp context.
717 	 */
718 	if (sk->sk_state != TCP_ESTABLISHED)
719 		return -ENOTCONN;
720 
721 	/* allocate tls context */
722 	write_lock_bh(&sk->sk_callback_lock);
723 	ctx = tls_ctx_create(sk);
724 	if (!ctx) {
725 		rc = -ENOMEM;
726 		goto out;
727 	}
728 
729 	ctx->tx_conf = TLS_BASE;
730 	ctx->rx_conf = TLS_BASE;
731 	update_sk_prot(sk, ctx);
732 out:
733 	write_unlock_bh(&sk->sk_callback_lock);
734 	return rc;
735 }
736 
737 static void tls_update(struct sock *sk, struct proto *p,
738 		       void (*write_space)(struct sock *sk))
739 {
740 	struct tls_context *ctx;
741 
742 	ctx = tls_get_ctx(sk);
743 	if (likely(ctx)) {
744 		ctx->sk_write_space = write_space;
745 		ctx->sk_proto = p;
746 	} else {
747 		/* Pairs with lockless read in sk_clone_lock(). */
748 		WRITE_ONCE(sk->sk_prot, p);
749 		sk->sk_write_space = write_space;
750 	}
751 }
752 
753 static int tls_get_info(const struct sock *sk, struct sk_buff *skb)
754 {
755 	u16 version, cipher_type;
756 	struct tls_context *ctx;
757 	struct nlattr *start;
758 	int err;
759 
760 	start = nla_nest_start_noflag(skb, INET_ULP_INFO_TLS);
761 	if (!start)
762 		return -EMSGSIZE;
763 
764 	rcu_read_lock();
765 	ctx = rcu_dereference(inet_csk(sk)->icsk_ulp_data);
766 	if (!ctx) {
767 		err = 0;
768 		goto nla_failure;
769 	}
770 	version = ctx->prot_info.version;
771 	if (version) {
772 		err = nla_put_u16(skb, TLS_INFO_VERSION, version);
773 		if (err)
774 			goto nla_failure;
775 	}
776 	cipher_type = ctx->prot_info.cipher_type;
777 	if (cipher_type) {
778 		err = nla_put_u16(skb, TLS_INFO_CIPHER, cipher_type);
779 		if (err)
780 			goto nla_failure;
781 	}
782 	err = nla_put_u16(skb, TLS_INFO_TXCONF, tls_user_config(ctx, true));
783 	if (err)
784 		goto nla_failure;
785 
786 	err = nla_put_u16(skb, TLS_INFO_RXCONF, tls_user_config(ctx, false));
787 	if (err)
788 		goto nla_failure;
789 
790 	rcu_read_unlock();
791 	nla_nest_end(skb, start);
792 	return 0;
793 
794 nla_failure:
795 	rcu_read_unlock();
796 	nla_nest_cancel(skb, start);
797 	return err;
798 }
799 
800 static size_t tls_get_info_size(const struct sock *sk)
801 {
802 	size_t size = 0;
803 
804 	size += nla_total_size(0) +		/* INET_ULP_INFO_TLS */
805 		nla_total_size(sizeof(u16)) +	/* TLS_INFO_VERSION */
806 		nla_total_size(sizeof(u16)) +	/* TLS_INFO_CIPHER */
807 		nla_total_size(sizeof(u16)) +	/* TLS_INFO_RXCONF */
808 		nla_total_size(sizeof(u16)) +	/* TLS_INFO_TXCONF */
809 		0;
810 
811 	return size;
812 }
813 
814 static int __net_init tls_init_net(struct net *net)
815 {
816 	int err;
817 
818 	net->mib.tls_statistics = alloc_percpu(struct linux_tls_mib);
819 	if (!net->mib.tls_statistics)
820 		return -ENOMEM;
821 
822 	err = tls_proc_init(net);
823 	if (err)
824 		goto err_free_stats;
825 
826 	return 0;
827 err_free_stats:
828 	free_percpu(net->mib.tls_statistics);
829 	return err;
830 }
831 
832 static void __net_exit tls_exit_net(struct net *net)
833 {
834 	tls_proc_fini(net);
835 	free_percpu(net->mib.tls_statistics);
836 }
837 
838 static struct pernet_operations tls_proc_ops = {
839 	.init = tls_init_net,
840 	.exit = tls_exit_net,
841 };
842 
843 static struct tcp_ulp_ops tcp_tls_ulp_ops __read_mostly = {
844 	.name			= "tls",
845 	.owner			= THIS_MODULE,
846 	.init			= tls_init,
847 	.update			= tls_update,
848 	.get_info		= tls_get_info,
849 	.get_info_size		= tls_get_info_size,
850 };
851 
852 static int __init tls_register(void)
853 {
854 	int err;
855 
856 	err = register_pernet_subsys(&tls_proc_ops);
857 	if (err)
858 		return err;
859 
860 	tls_sw_proto_ops = inet_stream_ops;
861 	tls_sw_proto_ops.splice_read = tls_sw_splice_read;
862 	tls_sw_proto_ops.sendpage_locked   = tls_sw_sendpage_locked,
863 
864 	tls_device_init();
865 	tcp_register_ulp(&tcp_tls_ulp_ops);
866 
867 	return 0;
868 }
869 
870 static void __exit tls_unregister(void)
871 {
872 	tcp_unregister_ulp(&tcp_tls_ulp_ops);
873 	tls_device_cleanup();
874 	unregister_pernet_subsys(&tls_proc_ops);
875 }
876 
877 module_init(tls_register);
878 module_exit(tls_unregister);
879