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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/tls.h>
45 
46 MODULE_AUTHOR("Mellanox Technologies");
47 MODULE_DESCRIPTION("Transport Layer Security Support");
48 MODULE_LICENSE("Dual BSD/GPL");
49 MODULE_ALIAS_TCP_ULP("tls");
50 
51 enum {
52 	TLSV4,
53 	TLSV6,
54 	TLS_NUM_PROTS,
55 };
56 
57 static struct proto *saved_tcpv6_prot;
58 static DEFINE_MUTEX(tcpv6_prot_mutex);
59 static struct proto *saved_tcpv4_prot;
60 static DEFINE_MUTEX(tcpv4_prot_mutex);
61 static LIST_HEAD(device_list);
62 static DEFINE_SPINLOCK(device_spinlock);
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 			 struct proto *base);
67 
update_sk_prot(struct sock * sk,struct tls_context * ctx)68 static 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 	sk->sk_prot = &tls_prots[ip_ver][ctx->tx_conf][ctx->rx_conf];
73 }
74 
wait_on_pending_writer(struct sock * sk,long * timeo)75 int wait_on_pending_writer(struct sock *sk, long *timeo)
76 {
77 	int rc = 0;
78 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
79 
80 	add_wait_queue(sk_sleep(sk), &wait);
81 	while (1) {
82 		if (!*timeo) {
83 			rc = -EAGAIN;
84 			break;
85 		}
86 
87 		if (signal_pending(current)) {
88 			rc = sock_intr_errno(*timeo);
89 			break;
90 		}
91 
92 		if (sk_wait_event(sk, timeo, !sk->sk_write_pending, &wait))
93 			break;
94 	}
95 	remove_wait_queue(sk_sleep(sk), &wait);
96 	return rc;
97 }
98 
tls_push_sg(struct sock * sk,struct tls_context * ctx,struct scatterlist * sg,u16 first_offset,int flags)99 int tls_push_sg(struct sock *sk,
100 		struct tls_context *ctx,
101 		struct scatterlist *sg,
102 		u16 first_offset,
103 		int flags)
104 {
105 	int sendpage_flags = flags | MSG_SENDPAGE_NOTLAST;
106 	int ret = 0;
107 	struct page *p;
108 	size_t size;
109 	int offset = first_offset;
110 
111 	size = sg->length - offset;
112 	offset += sg->offset;
113 
114 	ctx->in_tcp_sendpages = true;
115 	while (1) {
116 		if (sg_is_last(sg))
117 			sendpage_flags = flags;
118 
119 		/* is sending application-limited? */
120 		tcp_rate_check_app_limited(sk);
121 		p = sg_page(sg);
122 retry:
123 		ret = do_tcp_sendpages(sk, p, offset, size, sendpage_flags);
124 
125 		if (ret != size) {
126 			if (ret > 0) {
127 				offset += ret;
128 				size -= ret;
129 				goto retry;
130 			}
131 
132 			offset -= sg->offset;
133 			ctx->partially_sent_offset = offset;
134 			ctx->partially_sent_record = (void *)sg;
135 			ctx->in_tcp_sendpages = false;
136 			return ret;
137 		}
138 
139 		put_page(p);
140 		sk_mem_uncharge(sk, sg->length);
141 		sg = sg_next(sg);
142 		if (!sg)
143 			break;
144 
145 		offset = sg->offset;
146 		size = sg->length;
147 	}
148 
149 	ctx->in_tcp_sendpages = false;
150 
151 	return 0;
152 }
153 
tls_handle_open_record(struct sock * sk,int flags)154 static int tls_handle_open_record(struct sock *sk, int flags)
155 {
156 	struct tls_context *ctx = tls_get_ctx(sk);
157 
158 	if (tls_is_pending_open_record(ctx))
159 		return ctx->push_pending_record(sk, flags);
160 
161 	return 0;
162 }
163 
tls_proccess_cmsg(struct sock * sk,struct msghdr * msg,unsigned char * record_type)164 int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
165 		      unsigned char *record_type)
166 {
167 	struct cmsghdr *cmsg;
168 	int rc = -EINVAL;
169 
170 	for_each_cmsghdr(cmsg, msg) {
171 		if (!CMSG_OK(msg, cmsg))
172 			return -EINVAL;
173 		if (cmsg->cmsg_level != SOL_TLS)
174 			continue;
175 
176 		switch (cmsg->cmsg_type) {
177 		case TLS_SET_RECORD_TYPE:
178 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(*record_type)))
179 				return -EINVAL;
180 
181 			if (msg->msg_flags & MSG_MORE)
182 				return -EINVAL;
183 
184 			rc = tls_handle_open_record(sk, msg->msg_flags);
185 			if (rc)
186 				return rc;
187 
188 			*record_type = *(unsigned char *)CMSG_DATA(cmsg);
189 			rc = 0;
190 			break;
191 		default:
192 			return -EINVAL;
193 		}
194 	}
195 
196 	return rc;
197 }
198 
tls_push_partial_record(struct sock * sk,struct tls_context * ctx,int flags)199 int tls_push_partial_record(struct sock *sk, struct tls_context *ctx,
200 			    int flags)
201 {
202 	struct scatterlist *sg;
203 	u16 offset;
204 
205 	sg = ctx->partially_sent_record;
206 	offset = ctx->partially_sent_offset;
207 
208 	ctx->partially_sent_record = NULL;
209 	return tls_push_sg(sk, ctx, sg, offset, flags);
210 }
211 
tls_free_partial_record(struct sock * sk,struct tls_context * ctx)212 void tls_free_partial_record(struct sock *sk, struct tls_context *ctx)
213 {
214 	struct scatterlist *sg;
215 
216 	for (sg = ctx->partially_sent_record; sg; sg = sg_next(sg)) {
217 		put_page(sg_page(sg));
218 		sk_mem_uncharge(sk, sg->length);
219 	}
220 	ctx->partially_sent_record = NULL;
221 }
222 
tls_write_space(struct sock * sk)223 static void tls_write_space(struct sock *sk)
224 {
225 	struct tls_context *ctx = tls_get_ctx(sk);
226 
227 	/* If in_tcp_sendpages call lower protocol write space handler
228 	 * to ensure we wake up any waiting operations there. For example
229 	 * if do_tcp_sendpages where to call sk_wait_event.
230 	 */
231 	if (ctx->in_tcp_sendpages) {
232 		ctx->sk_write_space(sk);
233 		return;
234 	}
235 
236 #ifdef CONFIG_TLS_DEVICE
237 	if (ctx->tx_conf == TLS_HW)
238 		tls_device_write_space(sk, ctx);
239 	else
240 #endif
241 		tls_sw_write_space(sk, ctx);
242 
243 	ctx->sk_write_space(sk);
244 }
245 
246 /**
247  * tls_ctx_free() - free TLS ULP context
248  * @sk:  socket to with @ctx is attached
249  * @ctx: TLS context structure
250  *
251  * Free TLS context. If @sk is %NULL caller guarantees that the socket
252  * to which @ctx was attached has no outstanding references.
253  */
tls_ctx_free(struct sock * sk,struct tls_context * ctx)254 void tls_ctx_free(struct sock *sk, 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 	mutex_destroy(&ctx->tx_lock);
262 
263 	if (sk)
264 		kfree_rcu(ctx, rcu);
265 	else
266 		kfree(ctx);
267 }
268 
tls_sk_proto_cleanup(struct sock * sk,struct tls_context * ctx,long timeo)269 static void tls_sk_proto_cleanup(struct sock *sk,
270 				 struct tls_context *ctx, long timeo)
271 {
272 	if (unlikely(sk->sk_write_pending) &&
273 	    !wait_on_pending_writer(sk, &timeo))
274 		tls_handle_open_record(sk, 0);
275 
276 	/* We need these for tls_sw_fallback handling of other packets */
277 	if (ctx->tx_conf == TLS_SW) {
278 		kfree(ctx->tx.rec_seq);
279 		kfree(ctx->tx.iv);
280 		tls_sw_release_resources_tx(sk);
281 	} else if (ctx->tx_conf == TLS_HW) {
282 		tls_device_free_resources_tx(sk);
283 	}
284 
285 	if (ctx->rx_conf == TLS_SW)
286 		tls_sw_release_resources_rx(sk);
287 	else if (ctx->rx_conf == TLS_HW)
288 		tls_device_offload_cleanup_rx(sk);
289 }
290 
tls_sk_proto_close(struct sock * sk,long timeout)291 static void tls_sk_proto_close(struct sock *sk, long timeout)
292 {
293 	struct inet_connection_sock *icsk = inet_csk(sk);
294 	struct tls_context *ctx = tls_get_ctx(sk);
295 	long timeo = sock_sndtimeo(sk, 0);
296 	bool free_ctx;
297 
298 	if (ctx->tx_conf == TLS_SW)
299 		tls_sw_cancel_work_tx(ctx);
300 
301 	lock_sock(sk);
302 	free_ctx = ctx->tx_conf != TLS_HW && ctx->rx_conf != TLS_HW;
303 
304 	if (ctx->tx_conf != TLS_BASE || ctx->rx_conf != TLS_BASE)
305 		tls_sk_proto_cleanup(sk, ctx, timeo);
306 
307 	write_lock_bh(&sk->sk_callback_lock);
308 	if (free_ctx)
309 		rcu_assign_pointer(icsk->icsk_ulp_data, NULL);
310 	sk->sk_prot = ctx->sk_proto;
311 	if (sk->sk_write_space == tls_write_space)
312 		sk->sk_write_space = ctx->sk_write_space;
313 	write_unlock_bh(&sk->sk_callback_lock);
314 	release_sock(sk);
315 	if (ctx->tx_conf == TLS_SW)
316 		tls_sw_free_ctx_tx(ctx);
317 	if (ctx->rx_conf == TLS_SW || ctx->rx_conf == TLS_HW)
318 		tls_sw_strparser_done(ctx);
319 	if (ctx->rx_conf == TLS_SW)
320 		tls_sw_free_ctx_rx(ctx);
321 	ctx->sk_proto->close(sk, timeout);
322 
323 	if (free_ctx)
324 		tls_ctx_free(sk, ctx);
325 }
326 
do_tls_getsockopt_tx(struct sock * sk,char __user * optval,int __user * optlen)327 static int do_tls_getsockopt_tx(struct sock *sk, char __user *optval,
328 				int __user *optlen)
329 {
330 	int rc = 0;
331 	struct tls_context *ctx = tls_get_ctx(sk);
332 	struct tls_crypto_info *crypto_info;
333 	int len;
334 
335 	if (get_user(len, optlen))
336 		return -EFAULT;
337 
338 	if (!optval || (len < sizeof(*crypto_info))) {
339 		rc = -EINVAL;
340 		goto out;
341 	}
342 
343 	if (!ctx) {
344 		rc = -EBUSY;
345 		goto out;
346 	}
347 
348 	/* get user crypto info */
349 	crypto_info = &ctx->crypto_send.info;
350 
351 	if (!TLS_CRYPTO_INFO_READY(crypto_info)) {
352 		rc = -EBUSY;
353 		goto out;
354 	}
355 
356 	if (len == sizeof(*crypto_info)) {
357 		if (copy_to_user(optval, crypto_info, sizeof(*crypto_info)))
358 			rc = -EFAULT;
359 		goto out;
360 	}
361 
362 	switch (crypto_info->cipher_type) {
363 	case TLS_CIPHER_AES_GCM_128: {
364 		struct tls12_crypto_info_aes_gcm_128 *
365 		  crypto_info_aes_gcm_128 =
366 		  container_of(crypto_info,
367 			       struct tls12_crypto_info_aes_gcm_128,
368 			       info);
369 
370 		if (len != sizeof(*crypto_info_aes_gcm_128)) {
371 			rc = -EINVAL;
372 			goto out;
373 		}
374 		memcpy(crypto_info_aes_gcm_128->iv,
375 		       ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
376 		       TLS_CIPHER_AES_GCM_128_IV_SIZE);
377 		memcpy(crypto_info_aes_gcm_128->rec_seq, ctx->tx.rec_seq,
378 		       TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE);
379 		if (copy_to_user(optval,
380 				 crypto_info_aes_gcm_128,
381 				 sizeof(*crypto_info_aes_gcm_128)))
382 			rc = -EFAULT;
383 		break;
384 	}
385 	case TLS_CIPHER_AES_GCM_256: {
386 		struct tls12_crypto_info_aes_gcm_256 *
387 		  crypto_info_aes_gcm_256 =
388 		  container_of(crypto_info,
389 			       struct tls12_crypto_info_aes_gcm_256,
390 			       info);
391 
392 		if (len != sizeof(*crypto_info_aes_gcm_256)) {
393 			rc = -EINVAL;
394 			goto out;
395 		}
396 		memcpy(crypto_info_aes_gcm_256->iv,
397 		       ctx->tx.iv + TLS_CIPHER_AES_GCM_256_SALT_SIZE,
398 		       TLS_CIPHER_AES_GCM_256_IV_SIZE);
399 		memcpy(crypto_info_aes_gcm_256->rec_seq, ctx->tx.rec_seq,
400 		       TLS_CIPHER_AES_GCM_256_REC_SEQ_SIZE);
401 		if (copy_to_user(optval,
402 				 crypto_info_aes_gcm_256,
403 				 sizeof(*crypto_info_aes_gcm_256)))
404 			rc = -EFAULT;
405 		break;
406 	}
407 	default:
408 		rc = -EINVAL;
409 	}
410 
411 out:
412 	return rc;
413 }
414 
do_tls_getsockopt(struct sock * sk,int optname,char __user * optval,int __user * optlen)415 static int do_tls_getsockopt(struct sock *sk, int optname,
416 			     char __user *optval, int __user *optlen)
417 {
418 	int rc = 0;
419 
420 	lock_sock(sk);
421 
422 	switch (optname) {
423 	case TLS_TX:
424 		rc = do_tls_getsockopt_tx(sk, optval, optlen);
425 		break;
426 	default:
427 		rc = -ENOPROTOOPT;
428 		break;
429 	}
430 
431 	release_sock(sk);
432 
433 	return rc;
434 }
435 
tls_getsockopt(struct sock * sk,int level,int optname,char __user * optval,int __user * optlen)436 static int tls_getsockopt(struct sock *sk, int level, int optname,
437 			  char __user *optval, int __user *optlen)
438 {
439 	struct tls_context *ctx = tls_get_ctx(sk);
440 
441 	if (level != SOL_TLS)
442 		return ctx->sk_proto->getsockopt(sk, level,
443 						 optname, optval, optlen);
444 
445 	return do_tls_getsockopt(sk, optname, optval, optlen);
446 }
447 
do_tls_setsockopt_conf(struct sock * sk,char __user * optval,unsigned int optlen,int tx)448 static int do_tls_setsockopt_conf(struct sock *sk, char __user *optval,
449 				  unsigned int optlen, int tx)
450 {
451 	struct tls_crypto_info *crypto_info;
452 	struct tls_crypto_info *alt_crypto_info;
453 	struct tls_context *ctx = tls_get_ctx(sk);
454 	size_t optsize;
455 	int rc = 0;
456 	int conf;
457 
458 	if (!optval || (optlen < sizeof(*crypto_info))) {
459 		rc = -EINVAL;
460 		goto out;
461 	}
462 
463 	if (tx) {
464 		crypto_info = &ctx->crypto_send.info;
465 		alt_crypto_info = &ctx->crypto_recv.info;
466 	} else {
467 		crypto_info = &ctx->crypto_recv.info;
468 		alt_crypto_info = &ctx->crypto_send.info;
469 	}
470 
471 	/* Currently we don't support set crypto info more than one time */
472 	if (TLS_CRYPTO_INFO_READY(crypto_info)) {
473 		rc = -EBUSY;
474 		goto out;
475 	}
476 
477 	rc = copy_from_user(crypto_info, optval, sizeof(*crypto_info));
478 	if (rc) {
479 		rc = -EFAULT;
480 		goto err_crypto_info;
481 	}
482 
483 	/* check version */
484 	if (crypto_info->version != TLS_1_2_VERSION &&
485 	    crypto_info->version != TLS_1_3_VERSION) {
486 		rc = -EINVAL;
487 		goto err_crypto_info;
488 	}
489 
490 	/* Ensure that TLS version and ciphers are same in both directions */
491 	if (TLS_CRYPTO_INFO_READY(alt_crypto_info)) {
492 		if (alt_crypto_info->version != crypto_info->version ||
493 		    alt_crypto_info->cipher_type != crypto_info->cipher_type) {
494 			rc = -EINVAL;
495 			goto err_crypto_info;
496 		}
497 	}
498 
499 	switch (crypto_info->cipher_type) {
500 	case TLS_CIPHER_AES_GCM_128:
501 		optsize = sizeof(struct tls12_crypto_info_aes_gcm_128);
502 		break;
503 	case TLS_CIPHER_AES_GCM_256: {
504 		optsize = sizeof(struct tls12_crypto_info_aes_gcm_256);
505 		break;
506 	}
507 	case TLS_CIPHER_AES_CCM_128:
508 		optsize = sizeof(struct tls12_crypto_info_aes_ccm_128);
509 		break;
510 	default:
511 		rc = -EINVAL;
512 		goto err_crypto_info;
513 	}
514 
515 	if (optlen != optsize) {
516 		rc = -EINVAL;
517 		goto err_crypto_info;
518 	}
519 
520 	rc = copy_from_user(crypto_info + 1, optval + sizeof(*crypto_info),
521 			    optlen - sizeof(*crypto_info));
522 	if (rc) {
523 		rc = -EFAULT;
524 		goto err_crypto_info;
525 	}
526 
527 	if (tx) {
528 		rc = tls_set_device_offload(sk, ctx);
529 		conf = TLS_HW;
530 		if (rc) {
531 			rc = tls_set_sw_offload(sk, ctx, 1);
532 			if (rc)
533 				goto err_crypto_info;
534 			conf = TLS_SW;
535 		}
536 	} else {
537 		rc = tls_set_device_offload_rx(sk, ctx);
538 		conf = TLS_HW;
539 		if (rc) {
540 			rc = tls_set_sw_offload(sk, ctx, 0);
541 			if (rc)
542 				goto err_crypto_info;
543 			conf = TLS_SW;
544 		}
545 		tls_sw_strparser_arm(sk, ctx);
546 	}
547 
548 	if (tx)
549 		ctx->tx_conf = conf;
550 	else
551 		ctx->rx_conf = conf;
552 	update_sk_prot(sk, ctx);
553 	if (tx) {
554 		ctx->sk_write_space = sk->sk_write_space;
555 		sk->sk_write_space = tls_write_space;
556 	} else {
557 		sk->sk_socket->ops = &tls_sw_proto_ops;
558 	}
559 	goto out;
560 
561 err_crypto_info:
562 	memzero_explicit(crypto_info, sizeof(union tls_crypto_context));
563 out:
564 	return rc;
565 }
566 
do_tls_setsockopt(struct sock * sk,int optname,char __user * optval,unsigned int optlen)567 static int do_tls_setsockopt(struct sock *sk, int optname,
568 			     char __user *optval, unsigned int optlen)
569 {
570 	int rc = 0;
571 
572 	switch (optname) {
573 	case TLS_TX:
574 	case TLS_RX:
575 		lock_sock(sk);
576 		rc = do_tls_setsockopt_conf(sk, optval, optlen,
577 					    optname == TLS_TX);
578 		release_sock(sk);
579 		break;
580 	default:
581 		rc = -ENOPROTOOPT;
582 		break;
583 	}
584 	return rc;
585 }
586 
tls_setsockopt(struct sock * sk,int level,int optname,char __user * optval,unsigned int optlen)587 static int tls_setsockopt(struct sock *sk, int level, int optname,
588 			  char __user *optval, unsigned int optlen)
589 {
590 	struct tls_context *ctx = tls_get_ctx(sk);
591 
592 	if (level != SOL_TLS)
593 		return ctx->sk_proto->setsockopt(sk, level, optname, optval,
594 						 optlen);
595 
596 	return do_tls_setsockopt(sk, optname, optval, optlen);
597 }
598 
create_ctx(struct sock * sk)599 static struct tls_context *create_ctx(struct sock *sk)
600 {
601 	struct inet_connection_sock *icsk = inet_csk(sk);
602 	struct tls_context *ctx;
603 
604 	ctx = kzalloc(sizeof(*ctx), GFP_ATOMIC);
605 	if (!ctx)
606 		return NULL;
607 
608 	mutex_init(&ctx->tx_lock);
609 	rcu_assign_pointer(icsk->icsk_ulp_data, ctx);
610 	ctx->sk_proto = sk->sk_prot;
611 	return ctx;
612 }
613 
tls_build_proto(struct sock * sk)614 static void tls_build_proto(struct sock *sk)
615 {
616 	int ip_ver = sk->sk_family == AF_INET6 ? TLSV6 : TLSV4;
617 
618 	/* Build IPv6 TLS whenever the address of tcpv6 _prot changes */
619 	if (ip_ver == TLSV6 &&
620 	    unlikely(sk->sk_prot != smp_load_acquire(&saved_tcpv6_prot))) {
621 		mutex_lock(&tcpv6_prot_mutex);
622 		if (likely(sk->sk_prot != saved_tcpv6_prot)) {
623 			build_protos(tls_prots[TLSV6], sk->sk_prot);
624 			smp_store_release(&saved_tcpv6_prot, sk->sk_prot);
625 		}
626 		mutex_unlock(&tcpv6_prot_mutex);
627 	}
628 
629 	if (ip_ver == TLSV4 &&
630 	    unlikely(sk->sk_prot != smp_load_acquire(&saved_tcpv4_prot))) {
631 		mutex_lock(&tcpv4_prot_mutex);
632 		if (likely(sk->sk_prot != saved_tcpv4_prot)) {
633 			build_protos(tls_prots[TLSV4], sk->sk_prot);
634 			smp_store_release(&saved_tcpv4_prot, sk->sk_prot);
635 		}
636 		mutex_unlock(&tcpv4_prot_mutex);
637 	}
638 }
639 
tls_hw_sk_destruct(struct sock * sk)640 static void tls_hw_sk_destruct(struct sock *sk)
641 {
642 	struct tls_context *ctx = tls_get_ctx(sk);
643 	struct inet_connection_sock *icsk = inet_csk(sk);
644 
645 	ctx->sk_destruct(sk);
646 	/* Free ctx */
647 	rcu_assign_pointer(icsk->icsk_ulp_data, NULL);
648 	tls_ctx_free(sk, ctx);
649 }
650 
tls_hw_prot(struct sock * sk)651 static int tls_hw_prot(struct sock *sk)
652 {
653 	struct tls_context *ctx;
654 	struct tls_device *dev;
655 	int rc = 0;
656 
657 	spin_lock_bh(&device_spinlock);
658 	list_for_each_entry(dev, &device_list, dev_list) {
659 		if (dev->feature && dev->feature(dev)) {
660 			ctx = create_ctx(sk);
661 			if (!ctx)
662 				goto out;
663 
664 			spin_unlock_bh(&device_spinlock);
665 			tls_build_proto(sk);
666 			ctx->sk_destruct = sk->sk_destruct;
667 			sk->sk_destruct = tls_hw_sk_destruct;
668 			ctx->rx_conf = TLS_HW_RECORD;
669 			ctx->tx_conf = TLS_HW_RECORD;
670 			update_sk_prot(sk, ctx);
671 			spin_lock_bh(&device_spinlock);
672 			rc = 1;
673 			break;
674 		}
675 	}
676 out:
677 	spin_unlock_bh(&device_spinlock);
678 	return rc;
679 }
680 
tls_hw_unhash(struct sock * sk)681 static void tls_hw_unhash(struct sock *sk)
682 {
683 	struct tls_context *ctx = tls_get_ctx(sk);
684 	struct tls_device *dev;
685 
686 	spin_lock_bh(&device_spinlock);
687 	list_for_each_entry(dev, &device_list, dev_list) {
688 		if (dev->unhash) {
689 			kref_get(&dev->kref);
690 			spin_unlock_bh(&device_spinlock);
691 			dev->unhash(dev, sk);
692 			kref_put(&dev->kref, dev->release);
693 			spin_lock_bh(&device_spinlock);
694 		}
695 	}
696 	spin_unlock_bh(&device_spinlock);
697 	ctx->sk_proto->unhash(sk);
698 }
699 
tls_hw_hash(struct sock * sk)700 static int tls_hw_hash(struct sock *sk)
701 {
702 	struct tls_context *ctx = tls_get_ctx(sk);
703 	struct tls_device *dev;
704 	int err;
705 
706 	err = ctx->sk_proto->hash(sk);
707 	spin_lock_bh(&device_spinlock);
708 	list_for_each_entry(dev, &device_list, dev_list) {
709 		if (dev->hash) {
710 			kref_get(&dev->kref);
711 			spin_unlock_bh(&device_spinlock);
712 			err |= dev->hash(dev, sk);
713 			kref_put(&dev->kref, dev->release);
714 			spin_lock_bh(&device_spinlock);
715 		}
716 	}
717 	spin_unlock_bh(&device_spinlock);
718 
719 	if (err)
720 		tls_hw_unhash(sk);
721 	return err;
722 }
723 
build_protos(struct proto prot[TLS_NUM_CONFIG][TLS_NUM_CONFIG],struct proto * base)724 static void build_protos(struct proto prot[TLS_NUM_CONFIG][TLS_NUM_CONFIG],
725 			 struct proto *base)
726 {
727 	prot[TLS_BASE][TLS_BASE] = *base;
728 	prot[TLS_BASE][TLS_BASE].setsockopt	= tls_setsockopt;
729 	prot[TLS_BASE][TLS_BASE].getsockopt	= tls_getsockopt;
730 	prot[TLS_BASE][TLS_BASE].close		= tls_sk_proto_close;
731 
732 	prot[TLS_SW][TLS_BASE] = prot[TLS_BASE][TLS_BASE];
733 	prot[TLS_SW][TLS_BASE].sendmsg		= tls_sw_sendmsg;
734 	prot[TLS_SW][TLS_BASE].sendpage		= tls_sw_sendpage;
735 
736 	prot[TLS_BASE][TLS_SW] = prot[TLS_BASE][TLS_BASE];
737 	prot[TLS_BASE][TLS_SW].recvmsg		  = tls_sw_recvmsg;
738 	prot[TLS_BASE][TLS_SW].stream_memory_read = tls_sw_stream_read;
739 	prot[TLS_BASE][TLS_SW].close		  = tls_sk_proto_close;
740 
741 	prot[TLS_SW][TLS_SW] = prot[TLS_SW][TLS_BASE];
742 	prot[TLS_SW][TLS_SW].recvmsg		= tls_sw_recvmsg;
743 	prot[TLS_SW][TLS_SW].stream_memory_read	= tls_sw_stream_read;
744 	prot[TLS_SW][TLS_SW].close		= tls_sk_proto_close;
745 
746 #ifdef CONFIG_TLS_DEVICE
747 	prot[TLS_HW][TLS_BASE] = prot[TLS_BASE][TLS_BASE];
748 	prot[TLS_HW][TLS_BASE].sendmsg		= tls_device_sendmsg;
749 	prot[TLS_HW][TLS_BASE].sendpage		= tls_device_sendpage;
750 
751 	prot[TLS_HW][TLS_SW] = prot[TLS_BASE][TLS_SW];
752 	prot[TLS_HW][TLS_SW].sendmsg		= tls_device_sendmsg;
753 	prot[TLS_HW][TLS_SW].sendpage		= tls_device_sendpage;
754 
755 	prot[TLS_BASE][TLS_HW] = prot[TLS_BASE][TLS_SW];
756 
757 	prot[TLS_SW][TLS_HW] = prot[TLS_SW][TLS_SW];
758 
759 	prot[TLS_HW][TLS_HW] = prot[TLS_HW][TLS_SW];
760 #endif
761 
762 	prot[TLS_HW_RECORD][TLS_HW_RECORD] = *base;
763 	prot[TLS_HW_RECORD][TLS_HW_RECORD].hash		= tls_hw_hash;
764 	prot[TLS_HW_RECORD][TLS_HW_RECORD].unhash	= tls_hw_unhash;
765 }
766 
tls_init(struct sock * sk)767 static int tls_init(struct sock *sk)
768 {
769 	struct tls_context *ctx;
770 	int rc = 0;
771 
772 	if (tls_hw_prot(sk))
773 		return 0;
774 
775 	/* The TLS ulp is currently supported only for TCP sockets
776 	 * in ESTABLISHED state.
777 	 * Supporting sockets in LISTEN state will require us
778 	 * to modify the accept implementation to clone rather then
779 	 * share the ulp context.
780 	 */
781 	if (sk->sk_state != TCP_ESTABLISHED)
782 		return -ENOTCONN;
783 
784 	tls_build_proto(sk);
785 
786 	/* allocate tls context */
787 	write_lock_bh(&sk->sk_callback_lock);
788 	ctx = create_ctx(sk);
789 	if (!ctx) {
790 		rc = -ENOMEM;
791 		goto out;
792 	}
793 
794 	ctx->tx_conf = TLS_BASE;
795 	ctx->rx_conf = TLS_BASE;
796 	update_sk_prot(sk, ctx);
797 out:
798 	write_unlock_bh(&sk->sk_callback_lock);
799 	return rc;
800 }
801 
tls_update(struct sock * sk,struct proto * p,void (* write_space)(struct sock * sk))802 static void tls_update(struct sock *sk, struct proto *p,
803 		       void (*write_space)(struct sock *sk))
804 {
805 	struct tls_context *ctx;
806 
807 	ctx = tls_get_ctx(sk);
808 	if (likely(ctx)) {
809 		ctx->sk_write_space = write_space;
810 		ctx->sk_proto = p;
811 	} else {
812 		sk->sk_prot = p;
813 		sk->sk_write_space = write_space;
814 	}
815 }
816 
tls_get_info(const struct sock * sk,struct sk_buff * skb)817 static int tls_get_info(const struct sock *sk, struct sk_buff *skb)
818 {
819 	u16 version, cipher_type;
820 	struct tls_context *ctx;
821 	struct nlattr *start;
822 	int err;
823 
824 	start = nla_nest_start_noflag(skb, INET_ULP_INFO_TLS);
825 	if (!start)
826 		return -EMSGSIZE;
827 
828 	rcu_read_lock();
829 	ctx = rcu_dereference(inet_csk(sk)->icsk_ulp_data);
830 	if (!ctx) {
831 		err = 0;
832 		goto nla_failure;
833 	}
834 	version = ctx->prot_info.version;
835 	if (version) {
836 		err = nla_put_u16(skb, TLS_INFO_VERSION, version);
837 		if (err)
838 			goto nla_failure;
839 	}
840 	cipher_type = ctx->prot_info.cipher_type;
841 	if (cipher_type) {
842 		err = nla_put_u16(skb, TLS_INFO_CIPHER, cipher_type);
843 		if (err)
844 			goto nla_failure;
845 	}
846 	err = nla_put_u16(skb, TLS_INFO_TXCONF, tls_user_config(ctx, true));
847 	if (err)
848 		goto nla_failure;
849 
850 	err = nla_put_u16(skb, TLS_INFO_RXCONF, tls_user_config(ctx, false));
851 	if (err)
852 		goto nla_failure;
853 
854 	rcu_read_unlock();
855 	nla_nest_end(skb, start);
856 	return 0;
857 
858 nla_failure:
859 	rcu_read_unlock();
860 	nla_nest_cancel(skb, start);
861 	return err;
862 }
863 
tls_get_info_size(const struct sock * sk)864 static size_t tls_get_info_size(const struct sock *sk)
865 {
866 	size_t size = 0;
867 
868 	size += nla_total_size(0) +		/* INET_ULP_INFO_TLS */
869 		nla_total_size(sizeof(u16)) +	/* TLS_INFO_VERSION */
870 		nla_total_size(sizeof(u16)) +	/* TLS_INFO_CIPHER */
871 		nla_total_size(sizeof(u16)) +	/* TLS_INFO_RXCONF */
872 		nla_total_size(sizeof(u16)) +	/* TLS_INFO_TXCONF */
873 		0;
874 
875 	return size;
876 }
877 
tls_register_device(struct tls_device * device)878 void tls_register_device(struct tls_device *device)
879 {
880 	spin_lock_bh(&device_spinlock);
881 	list_add_tail(&device->dev_list, &device_list);
882 	spin_unlock_bh(&device_spinlock);
883 }
884 EXPORT_SYMBOL(tls_register_device);
885 
tls_unregister_device(struct tls_device * device)886 void tls_unregister_device(struct tls_device *device)
887 {
888 	spin_lock_bh(&device_spinlock);
889 	list_del(&device->dev_list);
890 	spin_unlock_bh(&device_spinlock);
891 }
892 EXPORT_SYMBOL(tls_unregister_device);
893 
894 static struct tcp_ulp_ops tcp_tls_ulp_ops __read_mostly = {
895 	.name			= "tls",
896 	.owner			= THIS_MODULE,
897 	.init			= tls_init,
898 	.update			= tls_update,
899 	.get_info		= tls_get_info,
900 	.get_info_size		= tls_get_info_size,
901 };
902 
tls_register(void)903 static int __init tls_register(void)
904 {
905 	tls_sw_proto_ops = inet_stream_ops;
906 	tls_sw_proto_ops.splice_read = tls_sw_splice_read;
907 	tls_sw_proto_ops.sendpage_locked   = tls_sw_sendpage_locked,
908 
909 	tls_device_init();
910 	tcp_register_ulp(&tcp_tls_ulp_ops);
911 
912 	return 0;
913 }
914 
tls_unregister(void)915 static void __exit tls_unregister(void)
916 {
917 	tcp_unregister_ulp(&tcp_tls_ulp_ops);
918 	tls_device_cleanup();
919 }
920 
921 module_init(tls_register);
922 module_exit(tls_unregister);
923