xref: /openbmc/linux/net/tls/tls_main.c (revision dbf563ee)
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 const struct proto *saved_tcpv6_prot;
60 static DEFINE_MUTEX(tcpv6_prot_mutex);
61 static const 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, sockptr_t 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 (sockptr_is_null(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_sockptr(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_sockptr_offset(crypto_info + 1, optval,
526 				      sizeof(*crypto_info),
527 				      optlen - sizeof(*crypto_info));
528 	if (rc) {
529 		rc = -EFAULT;
530 		goto err_crypto_info;
531 	}
532 
533 	if (tx) {
534 		rc = tls_set_device_offload(sk, ctx);
535 		conf = TLS_HW;
536 		if (!rc) {
537 			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSTXDEVICE);
538 			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSCURRTXDEVICE);
539 		} else {
540 			rc = tls_set_sw_offload(sk, ctx, 1);
541 			if (rc)
542 				goto err_crypto_info;
543 			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSTXSW);
544 			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSCURRTXSW);
545 			conf = TLS_SW;
546 		}
547 	} else {
548 		rc = tls_set_device_offload_rx(sk, ctx);
549 		conf = TLS_HW;
550 		if (!rc) {
551 			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSRXDEVICE);
552 			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSCURRRXDEVICE);
553 		} else {
554 			rc = tls_set_sw_offload(sk, ctx, 0);
555 			if (rc)
556 				goto err_crypto_info;
557 			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSRXSW);
558 			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSCURRRXSW);
559 			conf = TLS_SW;
560 		}
561 		tls_sw_strparser_arm(sk, ctx);
562 	}
563 
564 	if (tx)
565 		ctx->tx_conf = conf;
566 	else
567 		ctx->rx_conf = conf;
568 	update_sk_prot(sk, ctx);
569 	if (tx) {
570 		ctx->sk_write_space = sk->sk_write_space;
571 		sk->sk_write_space = tls_write_space;
572 	} else {
573 		sk->sk_socket->ops = &tls_sw_proto_ops;
574 	}
575 	goto out;
576 
577 err_crypto_info:
578 	memzero_explicit(crypto_info, sizeof(union tls_crypto_context));
579 out:
580 	return rc;
581 }
582 
583 static int do_tls_setsockopt(struct sock *sk, int optname, sockptr_t optval,
584 			     unsigned int optlen)
585 {
586 	int rc = 0;
587 
588 	switch (optname) {
589 	case TLS_TX:
590 	case TLS_RX:
591 		lock_sock(sk);
592 		rc = do_tls_setsockopt_conf(sk, optval, optlen,
593 					    optname == TLS_TX);
594 		release_sock(sk);
595 		break;
596 	default:
597 		rc = -ENOPROTOOPT;
598 		break;
599 	}
600 	return rc;
601 }
602 
603 static int tls_setsockopt(struct sock *sk, int level, int optname,
604 			  sockptr_t optval, unsigned int optlen)
605 {
606 	struct tls_context *ctx = tls_get_ctx(sk);
607 
608 	if (level != SOL_TLS)
609 		return ctx->sk_proto->setsockopt(sk, level, optname, optval,
610 						 optlen);
611 
612 	return do_tls_setsockopt(sk, optname, optval, optlen);
613 }
614 
615 struct tls_context *tls_ctx_create(struct sock *sk)
616 {
617 	struct inet_connection_sock *icsk = inet_csk(sk);
618 	struct tls_context *ctx;
619 
620 	ctx = kzalloc(sizeof(*ctx), GFP_ATOMIC);
621 	if (!ctx)
622 		return NULL;
623 
624 	mutex_init(&ctx->tx_lock);
625 	rcu_assign_pointer(icsk->icsk_ulp_data, ctx);
626 	ctx->sk_proto = READ_ONCE(sk->sk_prot);
627 	return ctx;
628 }
629 
630 static void tls_build_proto(struct sock *sk)
631 {
632 	int ip_ver = sk->sk_family == AF_INET6 ? TLSV6 : TLSV4;
633 	struct proto *prot = READ_ONCE(sk->sk_prot);
634 
635 	/* Build IPv6 TLS whenever the address of tcpv6 _prot changes */
636 	if (ip_ver == TLSV6 &&
637 	    unlikely(prot != smp_load_acquire(&saved_tcpv6_prot))) {
638 		mutex_lock(&tcpv6_prot_mutex);
639 		if (likely(prot != saved_tcpv6_prot)) {
640 			build_protos(tls_prots[TLSV6], prot);
641 			smp_store_release(&saved_tcpv6_prot, prot);
642 		}
643 		mutex_unlock(&tcpv6_prot_mutex);
644 	}
645 
646 	if (ip_ver == TLSV4 &&
647 	    unlikely(prot != smp_load_acquire(&saved_tcpv4_prot))) {
648 		mutex_lock(&tcpv4_prot_mutex);
649 		if (likely(prot != saved_tcpv4_prot)) {
650 			build_protos(tls_prots[TLSV4], prot);
651 			smp_store_release(&saved_tcpv4_prot, prot);
652 		}
653 		mutex_unlock(&tcpv4_prot_mutex);
654 	}
655 }
656 
657 static void build_protos(struct proto prot[TLS_NUM_CONFIG][TLS_NUM_CONFIG],
658 			 const struct proto *base)
659 {
660 	prot[TLS_BASE][TLS_BASE] = *base;
661 	prot[TLS_BASE][TLS_BASE].setsockopt	= tls_setsockopt;
662 	prot[TLS_BASE][TLS_BASE].getsockopt	= tls_getsockopt;
663 	prot[TLS_BASE][TLS_BASE].close		= tls_sk_proto_close;
664 
665 	prot[TLS_SW][TLS_BASE] = prot[TLS_BASE][TLS_BASE];
666 	prot[TLS_SW][TLS_BASE].sendmsg		= tls_sw_sendmsg;
667 	prot[TLS_SW][TLS_BASE].sendpage		= tls_sw_sendpage;
668 
669 	prot[TLS_BASE][TLS_SW] = prot[TLS_BASE][TLS_BASE];
670 	prot[TLS_BASE][TLS_SW].recvmsg		  = tls_sw_recvmsg;
671 	prot[TLS_BASE][TLS_SW].stream_memory_read = tls_sw_stream_read;
672 	prot[TLS_BASE][TLS_SW].close		  = tls_sk_proto_close;
673 
674 	prot[TLS_SW][TLS_SW] = prot[TLS_SW][TLS_BASE];
675 	prot[TLS_SW][TLS_SW].recvmsg		= tls_sw_recvmsg;
676 	prot[TLS_SW][TLS_SW].stream_memory_read	= tls_sw_stream_read;
677 	prot[TLS_SW][TLS_SW].close		= tls_sk_proto_close;
678 
679 #ifdef CONFIG_TLS_DEVICE
680 	prot[TLS_HW][TLS_BASE] = prot[TLS_BASE][TLS_BASE];
681 	prot[TLS_HW][TLS_BASE].sendmsg		= tls_device_sendmsg;
682 	prot[TLS_HW][TLS_BASE].sendpage		= tls_device_sendpage;
683 
684 	prot[TLS_HW][TLS_SW] = prot[TLS_BASE][TLS_SW];
685 	prot[TLS_HW][TLS_SW].sendmsg		= tls_device_sendmsg;
686 	prot[TLS_HW][TLS_SW].sendpage		= tls_device_sendpage;
687 
688 	prot[TLS_BASE][TLS_HW] = prot[TLS_BASE][TLS_SW];
689 
690 	prot[TLS_SW][TLS_HW] = prot[TLS_SW][TLS_SW];
691 
692 	prot[TLS_HW][TLS_HW] = prot[TLS_HW][TLS_SW];
693 #endif
694 #ifdef CONFIG_TLS_TOE
695 	prot[TLS_HW_RECORD][TLS_HW_RECORD] = *base;
696 	prot[TLS_HW_RECORD][TLS_HW_RECORD].hash		= tls_toe_hash;
697 	prot[TLS_HW_RECORD][TLS_HW_RECORD].unhash	= tls_toe_unhash;
698 #endif
699 }
700 
701 static int tls_init(struct sock *sk)
702 {
703 	struct tls_context *ctx;
704 	int rc = 0;
705 
706 	tls_build_proto(sk);
707 
708 #ifdef CONFIG_TLS_TOE
709 	if (tls_toe_bypass(sk))
710 		return 0;
711 #endif
712 
713 	/* The TLS ulp is currently supported only for TCP sockets
714 	 * in ESTABLISHED state.
715 	 * Supporting sockets in LISTEN state will require us
716 	 * to modify the accept implementation to clone rather then
717 	 * share the ulp context.
718 	 */
719 	if (sk->sk_state != TCP_ESTABLISHED)
720 		return -ENOTCONN;
721 
722 	/* allocate tls context */
723 	write_lock_bh(&sk->sk_callback_lock);
724 	ctx = tls_ctx_create(sk);
725 	if (!ctx) {
726 		rc = -ENOMEM;
727 		goto out;
728 	}
729 
730 	ctx->tx_conf = TLS_BASE;
731 	ctx->rx_conf = TLS_BASE;
732 	update_sk_prot(sk, ctx);
733 out:
734 	write_unlock_bh(&sk->sk_callback_lock);
735 	return rc;
736 }
737 
738 static void tls_update(struct sock *sk, struct proto *p,
739 		       void (*write_space)(struct sock *sk))
740 {
741 	struct tls_context *ctx;
742 
743 	ctx = tls_get_ctx(sk);
744 	if (likely(ctx)) {
745 		ctx->sk_write_space = write_space;
746 		ctx->sk_proto = p;
747 	} else {
748 		/* Pairs with lockless read in sk_clone_lock(). */
749 		WRITE_ONCE(sk->sk_prot, p);
750 		sk->sk_write_space = write_space;
751 	}
752 }
753 
754 static int tls_get_info(const struct sock *sk, struct sk_buff *skb)
755 {
756 	u16 version, cipher_type;
757 	struct tls_context *ctx;
758 	struct nlattr *start;
759 	int err;
760 
761 	start = nla_nest_start_noflag(skb, INET_ULP_INFO_TLS);
762 	if (!start)
763 		return -EMSGSIZE;
764 
765 	rcu_read_lock();
766 	ctx = rcu_dereference(inet_csk(sk)->icsk_ulp_data);
767 	if (!ctx) {
768 		err = 0;
769 		goto nla_failure;
770 	}
771 	version = ctx->prot_info.version;
772 	if (version) {
773 		err = nla_put_u16(skb, TLS_INFO_VERSION, version);
774 		if (err)
775 			goto nla_failure;
776 	}
777 	cipher_type = ctx->prot_info.cipher_type;
778 	if (cipher_type) {
779 		err = nla_put_u16(skb, TLS_INFO_CIPHER, cipher_type);
780 		if (err)
781 			goto nla_failure;
782 	}
783 	err = nla_put_u16(skb, TLS_INFO_TXCONF, tls_user_config(ctx, true));
784 	if (err)
785 		goto nla_failure;
786 
787 	err = nla_put_u16(skb, TLS_INFO_RXCONF, tls_user_config(ctx, false));
788 	if (err)
789 		goto nla_failure;
790 
791 	rcu_read_unlock();
792 	nla_nest_end(skb, start);
793 	return 0;
794 
795 nla_failure:
796 	rcu_read_unlock();
797 	nla_nest_cancel(skb, start);
798 	return err;
799 }
800 
801 static size_t tls_get_info_size(const struct sock *sk)
802 {
803 	size_t size = 0;
804 
805 	size += nla_total_size(0) +		/* INET_ULP_INFO_TLS */
806 		nla_total_size(sizeof(u16)) +	/* TLS_INFO_VERSION */
807 		nla_total_size(sizeof(u16)) +	/* TLS_INFO_CIPHER */
808 		nla_total_size(sizeof(u16)) +	/* TLS_INFO_RXCONF */
809 		nla_total_size(sizeof(u16)) +	/* TLS_INFO_TXCONF */
810 		0;
811 
812 	return size;
813 }
814 
815 static int __net_init tls_init_net(struct net *net)
816 {
817 	int err;
818 
819 	net->mib.tls_statistics = alloc_percpu(struct linux_tls_mib);
820 	if (!net->mib.tls_statistics)
821 		return -ENOMEM;
822 
823 	err = tls_proc_init(net);
824 	if (err)
825 		goto err_free_stats;
826 
827 	return 0;
828 err_free_stats:
829 	free_percpu(net->mib.tls_statistics);
830 	return err;
831 }
832 
833 static void __net_exit tls_exit_net(struct net *net)
834 {
835 	tls_proc_fini(net);
836 	free_percpu(net->mib.tls_statistics);
837 }
838 
839 static struct pernet_operations tls_proc_ops = {
840 	.init = tls_init_net,
841 	.exit = tls_exit_net,
842 };
843 
844 static struct tcp_ulp_ops tcp_tls_ulp_ops __read_mostly = {
845 	.name			= "tls",
846 	.owner			= THIS_MODULE,
847 	.init			= tls_init,
848 	.update			= tls_update,
849 	.get_info		= tls_get_info,
850 	.get_info_size		= tls_get_info_size,
851 };
852 
853 static int __init tls_register(void)
854 {
855 	int err;
856 
857 	err = register_pernet_subsys(&tls_proc_ops);
858 	if (err)
859 		return err;
860 
861 	tls_sw_proto_ops = inet_stream_ops;
862 	tls_sw_proto_ops.splice_read = tls_sw_splice_read;
863 	tls_sw_proto_ops.sendpage_locked   = tls_sw_sendpage_locked,
864 
865 	tls_device_init();
866 	tcp_register_ulp(&tcp_tls_ulp_ops);
867 
868 	return 0;
869 }
870 
871 static void __exit tls_unregister(void)
872 {
873 	tcp_unregister_ulp(&tcp_tls_ulp_ops);
874 	tls_device_cleanup();
875 	unregister_pernet_subsys(&tls_proc_ops);
876 }
877 
878 module_init(tls_register);
879 module_exit(tls_unregister);
880