xref: /linux/net/tls/tls_main.c (revision 6389a62ff798e781567645c0b0ca3dd7b8a4289d)
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 struct proto *saved_tcpv4_prot;
59 static DEFINE_MUTEX(tcpv4_prot_mutex);
60 static LIST_HEAD(device_list);
61 static DEFINE_SPINLOCK(device_spinlock);
62 static struct proto tls_prots[TLS_NUM_PROTS][TLS_NUM_CONFIG][TLS_NUM_CONFIG];
63 static struct proto_ops tls_sw_proto_ops;
64 static void build_protos(struct proto prot[TLS_NUM_CONFIG][TLS_NUM_CONFIG],
65 			 struct proto *base);
66 
67 static void update_sk_prot(struct sock *sk, struct tls_context *ctx)
68 {
69 	int ip_ver = sk->sk_family == AF_INET6 ? TLSV6 : TLSV4;
70 
71 	sk->sk_prot = &tls_prots[ip_ver][ctx->tx_conf][ctx->rx_conf];
72 }
73 
74 int wait_on_pending_writer(struct sock *sk, long *timeo)
75 {
76 	int rc = 0;
77 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
78 
79 	add_wait_queue(sk_sleep(sk), &wait);
80 	while (1) {
81 		if (!*timeo) {
82 			rc = -EAGAIN;
83 			break;
84 		}
85 
86 		if (signal_pending(current)) {
87 			rc = sock_intr_errno(*timeo);
88 			break;
89 		}
90 
91 		if (sk_wait_event(sk, timeo, !sk->sk_write_pending, &wait))
92 			break;
93 	}
94 	remove_wait_queue(sk_sleep(sk), &wait);
95 	return rc;
96 }
97 
98 int tls_push_sg(struct sock *sk,
99 		struct tls_context *ctx,
100 		struct scatterlist *sg,
101 		u16 first_offset,
102 		int flags)
103 {
104 	int sendpage_flags = flags | MSG_SENDPAGE_NOTLAST;
105 	int ret = 0;
106 	struct page *p;
107 	size_t size;
108 	int offset = first_offset;
109 
110 	size = sg->length - offset;
111 	offset += sg->offset;
112 
113 	ctx->in_tcp_sendpages = true;
114 	while (1) {
115 		if (sg_is_last(sg))
116 			sendpage_flags = flags;
117 
118 		/* is sending application-limited? */
119 		tcp_rate_check_app_limited(sk);
120 		p = sg_page(sg);
121 retry:
122 		ret = do_tcp_sendpages(sk, p, offset, size, sendpage_flags);
123 
124 		if (ret != size) {
125 			if (ret > 0) {
126 				offset += ret;
127 				size -= ret;
128 				goto retry;
129 			}
130 
131 			offset -= sg->offset;
132 			ctx->partially_sent_offset = offset;
133 			ctx->partially_sent_record = (void *)sg;
134 			ctx->in_tcp_sendpages = false;
135 			return ret;
136 		}
137 
138 		put_page(p);
139 		sk_mem_uncharge(sk, sg->length);
140 		sg = sg_next(sg);
141 		if (!sg)
142 			break;
143 
144 		offset = sg->offset;
145 		size = sg->length;
146 	}
147 
148 	ctx->in_tcp_sendpages = false;
149 
150 	return 0;
151 }
152 
153 static int tls_handle_open_record(struct sock *sk, int flags)
154 {
155 	struct tls_context *ctx = tls_get_ctx(sk);
156 
157 	if (tls_is_pending_open_record(ctx))
158 		return ctx->push_pending_record(sk, flags);
159 
160 	return 0;
161 }
162 
163 int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
164 		      unsigned char *record_type)
165 {
166 	struct cmsghdr *cmsg;
167 	int rc = -EINVAL;
168 
169 	for_each_cmsghdr(cmsg, msg) {
170 		if (!CMSG_OK(msg, cmsg))
171 			return -EINVAL;
172 		if (cmsg->cmsg_level != SOL_TLS)
173 			continue;
174 
175 		switch (cmsg->cmsg_type) {
176 		case TLS_SET_RECORD_TYPE:
177 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(*record_type)))
178 				return -EINVAL;
179 
180 			if (msg->msg_flags & MSG_MORE)
181 				return -EINVAL;
182 
183 			rc = tls_handle_open_record(sk, msg->msg_flags);
184 			if (rc)
185 				return rc;
186 
187 			*record_type = *(unsigned char *)CMSG_DATA(cmsg);
188 			rc = 0;
189 			break;
190 		default:
191 			return -EINVAL;
192 		}
193 	}
194 
195 	return rc;
196 }
197 
198 int tls_push_partial_record(struct sock *sk, struct tls_context *ctx,
199 			    int flags)
200 {
201 	struct scatterlist *sg;
202 	u16 offset;
203 
204 	sg = ctx->partially_sent_record;
205 	offset = ctx->partially_sent_offset;
206 
207 	ctx->partially_sent_record = NULL;
208 	return tls_push_sg(sk, ctx, sg, offset, flags);
209 }
210 
211 bool tls_free_partial_record(struct sock *sk, struct tls_context *ctx)
212 {
213 	struct scatterlist *sg;
214 
215 	sg = ctx->partially_sent_record;
216 	if (!sg)
217 		return false;
218 
219 	while (1) {
220 		put_page(sg_page(sg));
221 		sk_mem_uncharge(sk, sg->length);
222 
223 		if (sg_is_last(sg))
224 			break;
225 		sg++;
226 	}
227 	ctx->partially_sent_record = NULL;
228 	return true;
229 }
230 
231 static void tls_write_space(struct sock *sk)
232 {
233 	struct tls_context *ctx = tls_get_ctx(sk);
234 
235 	/* If in_tcp_sendpages call lower protocol write space handler
236 	 * to ensure we wake up any waiting operations there. For example
237 	 * if do_tcp_sendpages where to call sk_wait_event.
238 	 */
239 	if (ctx->in_tcp_sendpages) {
240 		ctx->sk_write_space(sk);
241 		return;
242 	}
243 
244 #ifdef CONFIG_TLS_DEVICE
245 	if (ctx->tx_conf == TLS_HW)
246 		tls_device_write_space(sk, ctx);
247 	else
248 #endif
249 		tls_sw_write_space(sk, ctx);
250 
251 	ctx->sk_write_space(sk);
252 }
253 
254 void tls_ctx_free(struct tls_context *ctx)
255 {
256 	if (!ctx)
257 		return;
258 
259 	memzero_explicit(&ctx->crypto_send, sizeof(ctx->crypto_send));
260 	memzero_explicit(&ctx->crypto_recv, sizeof(ctx->crypto_recv));
261 	kfree(ctx);
262 }
263 
264 static void tls_sk_proto_close(struct sock *sk, long timeout)
265 {
266 	struct tls_context *ctx = tls_get_ctx(sk);
267 	long timeo = sock_sndtimeo(sk, 0);
268 	void (*sk_proto_close)(struct sock *sk, long timeout);
269 	bool free_ctx = false;
270 
271 	lock_sock(sk);
272 	sk_proto_close = ctx->sk_proto_close;
273 
274 	if (ctx->tx_conf == TLS_HW_RECORD && ctx->rx_conf == TLS_HW_RECORD)
275 		goto skip_tx_cleanup;
276 
277 	if (ctx->tx_conf == TLS_BASE && ctx->rx_conf == TLS_BASE) {
278 		free_ctx = true;
279 		goto skip_tx_cleanup;
280 	}
281 
282 	if (unlikely(sk->sk_write_pending) &&
283 	    !wait_on_pending_writer(sk, &timeo))
284 		tls_handle_open_record(sk, 0);
285 
286 	/* We need these for tls_sw_fallback handling of other packets */
287 	if (ctx->tx_conf == TLS_SW) {
288 		kfree(ctx->tx.rec_seq);
289 		kfree(ctx->tx.iv);
290 		tls_sw_free_resources_tx(sk);
291 #ifdef CONFIG_TLS_DEVICE
292 	} else if (ctx->tx_conf == TLS_HW) {
293 		tls_device_free_resources_tx(sk);
294 #endif
295 	}
296 
297 	if (ctx->rx_conf == TLS_SW)
298 		tls_sw_free_resources_rx(sk);
299 
300 #ifdef CONFIG_TLS_DEVICE
301 	if (ctx->rx_conf == TLS_HW)
302 		tls_device_offload_cleanup_rx(sk);
303 
304 	if (ctx->tx_conf != TLS_HW && ctx->rx_conf != TLS_HW) {
305 #else
306 	{
307 #endif
308 		tls_ctx_free(ctx);
309 		ctx = NULL;
310 	}
311 
312 skip_tx_cleanup:
313 	release_sock(sk);
314 	sk_proto_close(sk, timeout);
315 	/* free ctx for TLS_HW_RECORD, used by tcp_set_state
316 	 * for sk->sk_prot->unhash [tls_hw_unhash]
317 	 */
318 	if (free_ctx)
319 		tls_ctx_free(ctx);
320 }
321 
322 static int do_tls_getsockopt_tx(struct sock *sk, char __user *optval,
323 				int __user *optlen)
324 {
325 	int rc = 0;
326 	struct tls_context *ctx = tls_get_ctx(sk);
327 	struct tls_crypto_info *crypto_info;
328 	int len;
329 
330 	if (get_user(len, optlen))
331 		return -EFAULT;
332 
333 	if (!optval || (len < sizeof(*crypto_info))) {
334 		rc = -EINVAL;
335 		goto out;
336 	}
337 
338 	if (!ctx) {
339 		rc = -EBUSY;
340 		goto out;
341 	}
342 
343 	/* get user crypto info */
344 	crypto_info = &ctx->crypto_send.info;
345 
346 	if (!TLS_CRYPTO_INFO_READY(crypto_info)) {
347 		rc = -EBUSY;
348 		goto out;
349 	}
350 
351 	if (len == sizeof(*crypto_info)) {
352 		if (copy_to_user(optval, crypto_info, sizeof(*crypto_info)))
353 			rc = -EFAULT;
354 		goto out;
355 	}
356 
357 	switch (crypto_info->cipher_type) {
358 	case TLS_CIPHER_AES_GCM_128: {
359 		struct tls12_crypto_info_aes_gcm_128 *
360 		  crypto_info_aes_gcm_128 =
361 		  container_of(crypto_info,
362 			       struct tls12_crypto_info_aes_gcm_128,
363 			       info);
364 
365 		if (len != sizeof(*crypto_info_aes_gcm_128)) {
366 			rc = -EINVAL;
367 			goto out;
368 		}
369 		lock_sock(sk);
370 		memcpy(crypto_info_aes_gcm_128->iv,
371 		       ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
372 		       TLS_CIPHER_AES_GCM_128_IV_SIZE);
373 		memcpy(crypto_info_aes_gcm_128->rec_seq, ctx->tx.rec_seq,
374 		       TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE);
375 		release_sock(sk);
376 		if (copy_to_user(optval,
377 				 crypto_info_aes_gcm_128,
378 				 sizeof(*crypto_info_aes_gcm_128)))
379 			rc = -EFAULT;
380 		break;
381 	}
382 	case TLS_CIPHER_AES_GCM_256: {
383 		struct tls12_crypto_info_aes_gcm_256 *
384 		  crypto_info_aes_gcm_256 =
385 		  container_of(crypto_info,
386 			       struct tls12_crypto_info_aes_gcm_256,
387 			       info);
388 
389 		if (len != sizeof(*crypto_info_aes_gcm_256)) {
390 			rc = -EINVAL;
391 			goto out;
392 		}
393 		lock_sock(sk);
394 		memcpy(crypto_info_aes_gcm_256->iv,
395 		       ctx->tx.iv + TLS_CIPHER_AES_GCM_256_SALT_SIZE,
396 		       TLS_CIPHER_AES_GCM_256_IV_SIZE);
397 		memcpy(crypto_info_aes_gcm_256->rec_seq, ctx->tx.rec_seq,
398 		       TLS_CIPHER_AES_GCM_256_REC_SEQ_SIZE);
399 		release_sock(sk);
400 		if (copy_to_user(optval,
401 				 crypto_info_aes_gcm_256,
402 				 sizeof(*crypto_info_aes_gcm_256)))
403 			rc = -EFAULT;
404 		break;
405 	}
406 	default:
407 		rc = -EINVAL;
408 	}
409 
410 out:
411 	return rc;
412 }
413 
414 static int do_tls_getsockopt(struct sock *sk, int optname,
415 			     char __user *optval, int __user *optlen)
416 {
417 	int rc = 0;
418 
419 	switch (optname) {
420 	case TLS_TX:
421 		rc = do_tls_getsockopt_tx(sk, optval, optlen);
422 		break;
423 	default:
424 		rc = -ENOPROTOOPT;
425 		break;
426 	}
427 	return rc;
428 }
429 
430 static int tls_getsockopt(struct sock *sk, int level, int optname,
431 			  char __user *optval, int __user *optlen)
432 {
433 	struct tls_context *ctx = tls_get_ctx(sk);
434 
435 	if (level != SOL_TLS)
436 		return ctx->getsockopt(sk, level, optname, optval, optlen);
437 
438 	return do_tls_getsockopt(sk, optname, optval, optlen);
439 }
440 
441 static int do_tls_setsockopt_conf(struct sock *sk, char __user *optval,
442 				  unsigned int optlen, int tx)
443 {
444 	struct tls_crypto_info *crypto_info;
445 	struct tls_crypto_info *alt_crypto_info;
446 	struct tls_context *ctx = tls_get_ctx(sk);
447 	size_t optsize;
448 	int rc = 0;
449 	int conf;
450 
451 	if (!optval || (optlen < sizeof(*crypto_info))) {
452 		rc = -EINVAL;
453 		goto out;
454 	}
455 
456 	if (tx) {
457 		crypto_info = &ctx->crypto_send.info;
458 		alt_crypto_info = &ctx->crypto_recv.info;
459 	} else {
460 		crypto_info = &ctx->crypto_recv.info;
461 		alt_crypto_info = &ctx->crypto_send.info;
462 	}
463 
464 	/* Currently we don't support set crypto info more than one time */
465 	if (TLS_CRYPTO_INFO_READY(crypto_info)) {
466 		rc = -EBUSY;
467 		goto out;
468 	}
469 
470 	rc = copy_from_user(crypto_info, optval, sizeof(*crypto_info));
471 	if (rc) {
472 		rc = -EFAULT;
473 		goto err_crypto_info;
474 	}
475 
476 	/* check version */
477 	if (crypto_info->version != TLS_1_2_VERSION &&
478 	    crypto_info->version != TLS_1_3_VERSION) {
479 		rc = -ENOTSUPP;
480 		goto err_crypto_info;
481 	}
482 
483 	/* Ensure that TLS version and ciphers are same in both directions */
484 	if (TLS_CRYPTO_INFO_READY(alt_crypto_info)) {
485 		if (alt_crypto_info->version != crypto_info->version ||
486 		    alt_crypto_info->cipher_type != crypto_info->cipher_type) {
487 			rc = -EINVAL;
488 			goto err_crypto_info;
489 		}
490 	}
491 
492 	switch (crypto_info->cipher_type) {
493 	case TLS_CIPHER_AES_GCM_128:
494 		optsize = sizeof(struct tls12_crypto_info_aes_gcm_128);
495 		break;
496 	case TLS_CIPHER_AES_GCM_256: {
497 		optsize = sizeof(struct tls12_crypto_info_aes_gcm_256);
498 		break;
499 	}
500 	case TLS_CIPHER_AES_CCM_128:
501 		optsize = sizeof(struct tls12_crypto_info_aes_ccm_128);
502 		break;
503 	default:
504 		rc = -EINVAL;
505 		goto err_crypto_info;
506 	}
507 
508 	if (optlen != optsize) {
509 		rc = -EINVAL;
510 		goto err_crypto_info;
511 	}
512 
513 	rc = copy_from_user(crypto_info + 1, optval + sizeof(*crypto_info),
514 			    optlen - sizeof(*crypto_info));
515 	if (rc) {
516 		rc = -EFAULT;
517 		goto err_crypto_info;
518 	}
519 
520 	if (tx) {
521 #ifdef CONFIG_TLS_DEVICE
522 		rc = tls_set_device_offload(sk, ctx);
523 		conf = TLS_HW;
524 		if (rc) {
525 #else
526 		{
527 #endif
528 			rc = tls_set_sw_offload(sk, ctx, 1);
529 			conf = TLS_SW;
530 		}
531 	} else {
532 #ifdef CONFIG_TLS_DEVICE
533 		rc = tls_set_device_offload_rx(sk, ctx);
534 		conf = TLS_HW;
535 		if (rc) {
536 #else
537 		{
538 #endif
539 			rc = tls_set_sw_offload(sk, ctx, 0);
540 			conf = TLS_SW;
541 		}
542 	}
543 
544 	if (rc)
545 		goto err_crypto_info;
546 
547 	if (tx)
548 		ctx->tx_conf = conf;
549 	else
550 		ctx->rx_conf = conf;
551 	update_sk_prot(sk, ctx);
552 	if (tx) {
553 		ctx->sk_write_space = sk->sk_write_space;
554 		sk->sk_write_space = tls_write_space;
555 	} else {
556 		sk->sk_socket->ops = &tls_sw_proto_ops;
557 	}
558 	goto out;
559 
560 err_crypto_info:
561 	memzero_explicit(crypto_info, sizeof(union tls_crypto_context));
562 out:
563 	return rc;
564 }
565 
566 static int do_tls_setsockopt(struct sock *sk, int optname,
567 			     char __user *optval, unsigned int optlen)
568 {
569 	int rc = 0;
570 
571 	switch (optname) {
572 	case TLS_TX:
573 	case TLS_RX:
574 		lock_sock(sk);
575 		rc = do_tls_setsockopt_conf(sk, optval, optlen,
576 					    optname == TLS_TX);
577 		release_sock(sk);
578 		break;
579 	default:
580 		rc = -ENOPROTOOPT;
581 		break;
582 	}
583 	return rc;
584 }
585 
586 static int tls_setsockopt(struct sock *sk, int level, int optname,
587 			  char __user *optval, unsigned int optlen)
588 {
589 	struct tls_context *ctx = tls_get_ctx(sk);
590 
591 	if (level != SOL_TLS)
592 		return ctx->setsockopt(sk, level, optname, optval, optlen);
593 
594 	return do_tls_setsockopt(sk, optname, optval, optlen);
595 }
596 
597 static struct tls_context *create_ctx(struct sock *sk)
598 {
599 	struct inet_connection_sock *icsk = inet_csk(sk);
600 	struct tls_context *ctx;
601 
602 	ctx = kzalloc(sizeof(*ctx), GFP_ATOMIC);
603 	if (!ctx)
604 		return NULL;
605 
606 	icsk->icsk_ulp_data = ctx;
607 	ctx->setsockopt = sk->sk_prot->setsockopt;
608 	ctx->getsockopt = sk->sk_prot->getsockopt;
609 	ctx->sk_proto_close = sk->sk_prot->close;
610 	return ctx;
611 }
612 
613 static void tls_build_proto(struct sock *sk)
614 {
615 	int ip_ver = sk->sk_family == AF_INET6 ? TLSV6 : TLSV4;
616 
617 	/* Build IPv6 TLS whenever the address of tcpv6 _prot changes */
618 	if (ip_ver == TLSV6 &&
619 	    unlikely(sk->sk_prot != smp_load_acquire(&saved_tcpv6_prot))) {
620 		mutex_lock(&tcpv6_prot_mutex);
621 		if (likely(sk->sk_prot != saved_tcpv6_prot)) {
622 			build_protos(tls_prots[TLSV6], sk->sk_prot);
623 			smp_store_release(&saved_tcpv6_prot, sk->sk_prot);
624 		}
625 		mutex_unlock(&tcpv6_prot_mutex);
626 	}
627 
628 	if (ip_ver == TLSV4 &&
629 	    unlikely(sk->sk_prot != smp_load_acquire(&saved_tcpv4_prot))) {
630 		mutex_lock(&tcpv4_prot_mutex);
631 		if (likely(sk->sk_prot != saved_tcpv4_prot)) {
632 			build_protos(tls_prots[TLSV4], sk->sk_prot);
633 			smp_store_release(&saved_tcpv4_prot, sk->sk_prot);
634 		}
635 		mutex_unlock(&tcpv4_prot_mutex);
636 	}
637 }
638 
639 static void tls_hw_sk_destruct(struct sock *sk)
640 {
641 	struct tls_context *ctx = tls_get_ctx(sk);
642 	struct inet_connection_sock *icsk = inet_csk(sk);
643 
644 	ctx->sk_destruct(sk);
645 	/* Free ctx */
646 	tls_ctx_free(ctx);
647 	icsk->icsk_ulp_data = NULL;
648 }
649 
650 static int tls_hw_prot(struct sock *sk)
651 {
652 	struct tls_context *ctx;
653 	struct tls_device *dev;
654 	int rc = 0;
655 
656 	spin_lock_bh(&device_spinlock);
657 	list_for_each_entry(dev, &device_list, dev_list) {
658 		if (dev->feature && dev->feature(dev)) {
659 			ctx = create_ctx(sk);
660 			if (!ctx)
661 				goto out;
662 
663 			spin_unlock_bh(&device_spinlock);
664 			tls_build_proto(sk);
665 			ctx->hash = sk->sk_prot->hash;
666 			ctx->unhash = sk->sk_prot->unhash;
667 			ctx->sk_proto_close = sk->sk_prot->close;
668 			ctx->sk_destruct = sk->sk_destruct;
669 			sk->sk_destruct = tls_hw_sk_destruct;
670 			ctx->rx_conf = TLS_HW_RECORD;
671 			ctx->tx_conf = TLS_HW_RECORD;
672 			update_sk_prot(sk, ctx);
673 			spin_lock_bh(&device_spinlock);
674 			rc = 1;
675 			break;
676 		}
677 	}
678 out:
679 	spin_unlock_bh(&device_spinlock);
680 	return rc;
681 }
682 
683 static void tls_hw_unhash(struct sock *sk)
684 {
685 	struct tls_context *ctx = tls_get_ctx(sk);
686 	struct tls_device *dev;
687 
688 	spin_lock_bh(&device_spinlock);
689 	list_for_each_entry(dev, &device_list, dev_list) {
690 		if (dev->unhash) {
691 			kref_get(&dev->kref);
692 			spin_unlock_bh(&device_spinlock);
693 			dev->unhash(dev, sk);
694 			kref_put(&dev->kref, dev->release);
695 			spin_lock_bh(&device_spinlock);
696 		}
697 	}
698 	spin_unlock_bh(&device_spinlock);
699 	ctx->unhash(sk);
700 }
701 
702 static int tls_hw_hash(struct sock *sk)
703 {
704 	struct tls_context *ctx = tls_get_ctx(sk);
705 	struct tls_device *dev;
706 	int err;
707 
708 	err = ctx->hash(sk);
709 	spin_lock_bh(&device_spinlock);
710 	list_for_each_entry(dev, &device_list, dev_list) {
711 		if (dev->hash) {
712 			kref_get(&dev->kref);
713 			spin_unlock_bh(&device_spinlock);
714 			err |= dev->hash(dev, sk);
715 			kref_put(&dev->kref, dev->release);
716 			spin_lock_bh(&device_spinlock);
717 		}
718 	}
719 	spin_unlock_bh(&device_spinlock);
720 
721 	if (err)
722 		tls_hw_unhash(sk);
723 	return err;
724 }
725 
726 static void build_protos(struct proto prot[TLS_NUM_CONFIG][TLS_NUM_CONFIG],
727 			 struct proto *base)
728 {
729 	prot[TLS_BASE][TLS_BASE] = *base;
730 	prot[TLS_BASE][TLS_BASE].setsockopt	= tls_setsockopt;
731 	prot[TLS_BASE][TLS_BASE].getsockopt	= tls_getsockopt;
732 	prot[TLS_BASE][TLS_BASE].close		= tls_sk_proto_close;
733 
734 	prot[TLS_SW][TLS_BASE] = prot[TLS_BASE][TLS_BASE];
735 	prot[TLS_SW][TLS_BASE].sendmsg		= tls_sw_sendmsg;
736 	prot[TLS_SW][TLS_BASE].sendpage		= tls_sw_sendpage;
737 
738 	prot[TLS_BASE][TLS_SW] = prot[TLS_BASE][TLS_BASE];
739 	prot[TLS_BASE][TLS_SW].recvmsg		  = tls_sw_recvmsg;
740 	prot[TLS_BASE][TLS_SW].stream_memory_read = tls_sw_stream_read;
741 	prot[TLS_BASE][TLS_SW].close		  = tls_sk_proto_close;
742 
743 	prot[TLS_SW][TLS_SW] = prot[TLS_SW][TLS_BASE];
744 	prot[TLS_SW][TLS_SW].recvmsg		= tls_sw_recvmsg;
745 	prot[TLS_SW][TLS_SW].stream_memory_read	= tls_sw_stream_read;
746 	prot[TLS_SW][TLS_SW].close		= tls_sk_proto_close;
747 
748 #ifdef CONFIG_TLS_DEVICE
749 	prot[TLS_HW][TLS_BASE] = prot[TLS_BASE][TLS_BASE];
750 	prot[TLS_HW][TLS_BASE].sendmsg		= tls_device_sendmsg;
751 	prot[TLS_HW][TLS_BASE].sendpage		= tls_device_sendpage;
752 
753 	prot[TLS_HW][TLS_SW] = prot[TLS_BASE][TLS_SW];
754 	prot[TLS_HW][TLS_SW].sendmsg		= tls_device_sendmsg;
755 	prot[TLS_HW][TLS_SW].sendpage		= tls_device_sendpage;
756 
757 	prot[TLS_BASE][TLS_HW] = prot[TLS_BASE][TLS_SW];
758 
759 	prot[TLS_SW][TLS_HW] = prot[TLS_SW][TLS_SW];
760 
761 	prot[TLS_HW][TLS_HW] = prot[TLS_HW][TLS_SW];
762 #endif
763 
764 	prot[TLS_HW_RECORD][TLS_HW_RECORD] = *base;
765 	prot[TLS_HW_RECORD][TLS_HW_RECORD].hash		= tls_hw_hash;
766 	prot[TLS_HW_RECORD][TLS_HW_RECORD].unhash	= tls_hw_unhash;
767 	prot[TLS_HW_RECORD][TLS_HW_RECORD].close	= tls_sk_proto_close;
768 }
769 
770 static int tls_init(struct sock *sk)
771 {
772 	struct tls_context *ctx;
773 	int rc = 0;
774 
775 	if (tls_hw_prot(sk))
776 		goto out;
777 
778 	/* The TLS ulp is currently supported only for TCP sockets
779 	 * in ESTABLISHED state.
780 	 * Supporting sockets in LISTEN state will require us
781 	 * to modify the accept implementation to clone rather then
782 	 * share the ulp context.
783 	 */
784 	if (sk->sk_state != TCP_ESTABLISHED)
785 		return -ENOTSUPP;
786 
787 	/* allocate tls context */
788 	ctx = create_ctx(sk);
789 	if (!ctx) {
790 		rc = -ENOMEM;
791 		goto out;
792 	}
793 
794 	tls_build_proto(sk);
795 	ctx->tx_conf = TLS_BASE;
796 	ctx->rx_conf = TLS_BASE;
797 	update_sk_prot(sk, ctx);
798 out:
799 	return rc;
800 }
801 
802 void tls_register_device(struct tls_device *device)
803 {
804 	spin_lock_bh(&device_spinlock);
805 	list_add_tail(&device->dev_list, &device_list);
806 	spin_unlock_bh(&device_spinlock);
807 }
808 EXPORT_SYMBOL(tls_register_device);
809 
810 void tls_unregister_device(struct tls_device *device)
811 {
812 	spin_lock_bh(&device_spinlock);
813 	list_del(&device->dev_list);
814 	spin_unlock_bh(&device_spinlock);
815 }
816 EXPORT_SYMBOL(tls_unregister_device);
817 
818 static struct tcp_ulp_ops tcp_tls_ulp_ops __read_mostly = {
819 	.name			= "tls",
820 	.owner			= THIS_MODULE,
821 	.init			= tls_init,
822 };
823 
824 static int __init tls_register(void)
825 {
826 	tls_sw_proto_ops = inet_stream_ops;
827 	tls_sw_proto_ops.splice_read = tls_sw_splice_read;
828 
829 #ifdef CONFIG_TLS_DEVICE
830 	tls_device_init();
831 #endif
832 	tcp_register_ulp(&tcp_tls_ulp_ops);
833 
834 	return 0;
835 }
836 
837 static void __exit tls_unregister(void)
838 {
839 	tcp_unregister_ulp(&tcp_tls_ulp_ops);
840 #ifdef CONFIG_TLS_DEVICE
841 	tls_device_cleanup();
842 #endif
843 }
844 
845 module_init(tls_register);
846 module_exit(tls_unregister);
847