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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 		lock_sock(sk);
375 		memcpy(crypto_info_aes_gcm_128->iv,
376 		       ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
377 		       TLS_CIPHER_AES_GCM_128_IV_SIZE);
378 		memcpy(crypto_info_aes_gcm_128->rec_seq, ctx->tx.rec_seq,
379 		       TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE);
380 		release_sock(sk);
381 		if (copy_to_user(optval,
382 				 crypto_info_aes_gcm_128,
383 				 sizeof(*crypto_info_aes_gcm_128)))
384 			rc = -EFAULT;
385 		break;
386 	}
387 	case TLS_CIPHER_AES_GCM_256: {
388 		struct tls12_crypto_info_aes_gcm_256 *
389 		  crypto_info_aes_gcm_256 =
390 		  container_of(crypto_info,
391 			       struct tls12_crypto_info_aes_gcm_256,
392 			       info);
393 
394 		if (len != sizeof(*crypto_info_aes_gcm_256)) {
395 			rc = -EINVAL;
396 			goto out;
397 		}
398 		lock_sock(sk);
399 		memcpy(crypto_info_aes_gcm_256->iv,
400 		       ctx->tx.iv + TLS_CIPHER_AES_GCM_256_SALT_SIZE,
401 		       TLS_CIPHER_AES_GCM_256_IV_SIZE);
402 		memcpy(crypto_info_aes_gcm_256->rec_seq, ctx->tx.rec_seq,
403 		       TLS_CIPHER_AES_GCM_256_REC_SEQ_SIZE);
404 		release_sock(sk);
405 		if (copy_to_user(optval,
406 				 crypto_info_aes_gcm_256,
407 				 sizeof(*crypto_info_aes_gcm_256)))
408 			rc = -EFAULT;
409 		break;
410 	}
411 	default:
412 		rc = -EINVAL;
413 	}
414 
415 out:
416 	return rc;
417 }
418 
do_tls_getsockopt(struct sock * sk,int optname,char __user * optval,int __user * optlen)419 static int do_tls_getsockopt(struct sock *sk, int optname,
420 			     char __user *optval, int __user *optlen)
421 {
422 	int rc = 0;
423 
424 	switch (optname) {
425 	case TLS_TX:
426 		rc = do_tls_getsockopt_tx(sk, optval, optlen);
427 		break;
428 	default:
429 		rc = -ENOPROTOOPT;
430 		break;
431 	}
432 	return rc;
433 }
434 
tls_getsockopt(struct sock * sk,int level,int optname,char __user * optval,int __user * optlen)435 static int tls_getsockopt(struct sock *sk, int level, int optname,
436 			  char __user *optval, int __user *optlen)
437 {
438 	struct tls_context *ctx = tls_get_ctx(sk);
439 
440 	if (level != SOL_TLS)
441 		return ctx->sk_proto->getsockopt(sk, level,
442 						 optname, optval, optlen);
443 
444 	return do_tls_getsockopt(sk, optname, optval, optlen);
445 }
446 
do_tls_setsockopt_conf(struct sock * sk,char __user * optval,unsigned int optlen,int tx)447 static int do_tls_setsockopt_conf(struct sock *sk, char __user *optval,
448 				  unsigned int optlen, int tx)
449 {
450 	struct tls_crypto_info *crypto_info;
451 	struct tls_crypto_info *alt_crypto_info;
452 	struct tls_context *ctx = tls_get_ctx(sk);
453 	size_t optsize;
454 	int rc = 0;
455 	int conf;
456 
457 	if (!optval || (optlen < sizeof(*crypto_info))) {
458 		rc = -EINVAL;
459 		goto out;
460 	}
461 
462 	if (tx) {
463 		crypto_info = &ctx->crypto_send.info;
464 		alt_crypto_info = &ctx->crypto_recv.info;
465 	} else {
466 		crypto_info = &ctx->crypto_recv.info;
467 		alt_crypto_info = &ctx->crypto_send.info;
468 	}
469 
470 	/* Currently we don't support set crypto info more than one time */
471 	if (TLS_CRYPTO_INFO_READY(crypto_info)) {
472 		rc = -EBUSY;
473 		goto out;
474 	}
475 
476 	rc = copy_from_user(crypto_info, optval, sizeof(*crypto_info));
477 	if (rc) {
478 		rc = -EFAULT;
479 		goto err_crypto_info;
480 	}
481 
482 	/* check version */
483 	if (crypto_info->version != TLS_1_2_VERSION &&
484 	    crypto_info->version != TLS_1_3_VERSION) {
485 		rc = -EINVAL;
486 		goto err_crypto_info;
487 	}
488 
489 	/* Ensure that TLS version and ciphers are same in both directions */
490 	if (TLS_CRYPTO_INFO_READY(alt_crypto_info)) {
491 		if (alt_crypto_info->version != crypto_info->version ||
492 		    alt_crypto_info->cipher_type != crypto_info->cipher_type) {
493 			rc = -EINVAL;
494 			goto err_crypto_info;
495 		}
496 	}
497 
498 	switch (crypto_info->cipher_type) {
499 	case TLS_CIPHER_AES_GCM_128:
500 		optsize = sizeof(struct tls12_crypto_info_aes_gcm_128);
501 		break;
502 	case TLS_CIPHER_AES_GCM_256: {
503 		optsize = sizeof(struct tls12_crypto_info_aes_gcm_256);
504 		break;
505 	}
506 	case TLS_CIPHER_AES_CCM_128:
507 		optsize = sizeof(struct tls12_crypto_info_aes_ccm_128);
508 		break;
509 	default:
510 		rc = -EINVAL;
511 		goto err_crypto_info;
512 	}
513 
514 	if (optlen != optsize) {
515 		rc = -EINVAL;
516 		goto err_crypto_info;
517 	}
518 
519 	rc = copy_from_user(crypto_info + 1, optval + sizeof(*crypto_info),
520 			    optlen - sizeof(*crypto_info));
521 	if (rc) {
522 		rc = -EFAULT;
523 		goto err_crypto_info;
524 	}
525 
526 	if (tx) {
527 		rc = tls_set_device_offload(sk, ctx);
528 		conf = TLS_HW;
529 		if (rc) {
530 			rc = tls_set_sw_offload(sk, ctx, 1);
531 			if (rc)
532 				goto err_crypto_info;
533 			conf = TLS_SW;
534 		}
535 	} else {
536 		rc = tls_set_device_offload_rx(sk, ctx);
537 		conf = TLS_HW;
538 		if (rc) {
539 			rc = tls_set_sw_offload(sk, ctx, 0);
540 			if (rc)
541 				goto err_crypto_info;
542 			conf = TLS_SW;
543 		}
544 		tls_sw_strparser_arm(sk, ctx);
545 	}
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 
do_tls_setsockopt(struct sock * sk,int optname,char __user * optval,unsigned int optlen)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 
tls_setsockopt(struct sock * sk,int level,int optname,char __user * optval,unsigned int optlen)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->sk_proto->setsockopt(sk, level, optname, optval,
593 						 optlen);
594 
595 	return do_tls_setsockopt(sk, optname, optval, optlen);
596 }
597 
create_ctx(struct sock * sk)598 static struct tls_context *create_ctx(struct sock *sk)
599 {
600 	struct inet_connection_sock *icsk = inet_csk(sk);
601 	struct tls_context *ctx;
602 
603 	ctx = kzalloc(sizeof(*ctx), GFP_ATOMIC);
604 	if (!ctx)
605 		return NULL;
606 
607 	mutex_init(&ctx->tx_lock);
608 	rcu_assign_pointer(icsk->icsk_ulp_data, ctx);
609 	ctx->sk_proto = sk->sk_prot;
610 	return ctx;
611 }
612 
tls_build_proto(struct sock * sk)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 
tls_hw_sk_destruct(struct sock * sk)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 	rcu_assign_pointer(icsk->icsk_ulp_data, NULL);
647 	tls_ctx_free(sk, ctx);
648 }
649 
tls_hw_prot(struct sock * sk)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->sk_destruct = sk->sk_destruct;
666 			sk->sk_destruct = tls_hw_sk_destruct;
667 			ctx->rx_conf = TLS_HW_RECORD;
668 			ctx->tx_conf = TLS_HW_RECORD;
669 			update_sk_prot(sk, ctx);
670 			spin_lock_bh(&device_spinlock);
671 			rc = 1;
672 			break;
673 		}
674 	}
675 out:
676 	spin_unlock_bh(&device_spinlock);
677 	return rc;
678 }
679 
tls_hw_unhash(struct sock * sk)680 static void tls_hw_unhash(struct sock *sk)
681 {
682 	struct tls_context *ctx = tls_get_ctx(sk);
683 	struct tls_device *dev;
684 
685 	spin_lock_bh(&device_spinlock);
686 	list_for_each_entry(dev, &device_list, dev_list) {
687 		if (dev->unhash) {
688 			kref_get(&dev->kref);
689 			spin_unlock_bh(&device_spinlock);
690 			dev->unhash(dev, sk);
691 			kref_put(&dev->kref, dev->release);
692 			spin_lock_bh(&device_spinlock);
693 		}
694 	}
695 	spin_unlock_bh(&device_spinlock);
696 	ctx->sk_proto->unhash(sk);
697 }
698 
tls_hw_hash(struct sock * sk)699 static int tls_hw_hash(struct sock *sk)
700 {
701 	struct tls_context *ctx = tls_get_ctx(sk);
702 	struct tls_device *dev;
703 	int err;
704 
705 	err = ctx->sk_proto->hash(sk);
706 	spin_lock_bh(&device_spinlock);
707 	list_for_each_entry(dev, &device_list, dev_list) {
708 		if (dev->hash) {
709 			kref_get(&dev->kref);
710 			spin_unlock_bh(&device_spinlock);
711 			err |= dev->hash(dev, sk);
712 			kref_put(&dev->kref, dev->release);
713 			spin_lock_bh(&device_spinlock);
714 		}
715 	}
716 	spin_unlock_bh(&device_spinlock);
717 
718 	if (err)
719 		tls_hw_unhash(sk);
720 	return err;
721 }
722 
build_protos(struct proto prot[TLS_NUM_CONFIG][TLS_NUM_CONFIG],struct proto * base)723 static void build_protos(struct proto prot[TLS_NUM_CONFIG][TLS_NUM_CONFIG],
724 			 struct proto *base)
725 {
726 	prot[TLS_BASE][TLS_BASE] = *base;
727 	prot[TLS_BASE][TLS_BASE].setsockopt	= tls_setsockopt;
728 	prot[TLS_BASE][TLS_BASE].getsockopt	= tls_getsockopt;
729 	prot[TLS_BASE][TLS_BASE].close		= tls_sk_proto_close;
730 
731 	prot[TLS_SW][TLS_BASE] = prot[TLS_BASE][TLS_BASE];
732 	prot[TLS_SW][TLS_BASE].sendmsg		= tls_sw_sendmsg;
733 	prot[TLS_SW][TLS_BASE].sendpage		= tls_sw_sendpage;
734 
735 	prot[TLS_BASE][TLS_SW] = prot[TLS_BASE][TLS_BASE];
736 	prot[TLS_BASE][TLS_SW].recvmsg		  = tls_sw_recvmsg;
737 	prot[TLS_BASE][TLS_SW].stream_memory_read = tls_sw_stream_read;
738 	prot[TLS_BASE][TLS_SW].close		  = tls_sk_proto_close;
739 
740 	prot[TLS_SW][TLS_SW] = prot[TLS_SW][TLS_BASE];
741 	prot[TLS_SW][TLS_SW].recvmsg		= tls_sw_recvmsg;
742 	prot[TLS_SW][TLS_SW].stream_memory_read	= tls_sw_stream_read;
743 	prot[TLS_SW][TLS_SW].close		= tls_sk_proto_close;
744 
745 #ifdef CONFIG_TLS_DEVICE
746 	prot[TLS_HW][TLS_BASE] = prot[TLS_BASE][TLS_BASE];
747 	prot[TLS_HW][TLS_BASE].sendmsg		= tls_device_sendmsg;
748 	prot[TLS_HW][TLS_BASE].sendpage		= tls_device_sendpage;
749 
750 	prot[TLS_HW][TLS_SW] = prot[TLS_BASE][TLS_SW];
751 	prot[TLS_HW][TLS_SW].sendmsg		= tls_device_sendmsg;
752 	prot[TLS_HW][TLS_SW].sendpage		= tls_device_sendpage;
753 
754 	prot[TLS_BASE][TLS_HW] = prot[TLS_BASE][TLS_SW];
755 
756 	prot[TLS_SW][TLS_HW] = prot[TLS_SW][TLS_SW];
757 
758 	prot[TLS_HW][TLS_HW] = prot[TLS_HW][TLS_SW];
759 #endif
760 
761 	prot[TLS_HW_RECORD][TLS_HW_RECORD] = *base;
762 	prot[TLS_HW_RECORD][TLS_HW_RECORD].hash		= tls_hw_hash;
763 	prot[TLS_HW_RECORD][TLS_HW_RECORD].unhash	= tls_hw_unhash;
764 }
765 
tls_init(struct sock * sk)766 static int tls_init(struct sock *sk)
767 {
768 	struct tls_context *ctx;
769 	int rc = 0;
770 
771 	if (tls_hw_prot(sk))
772 		return 0;
773 
774 	/* The TLS ulp is currently supported only for TCP sockets
775 	 * in ESTABLISHED state.
776 	 * Supporting sockets in LISTEN state will require us
777 	 * to modify the accept implementation to clone rather then
778 	 * share the ulp context.
779 	 */
780 	if (sk->sk_state != TCP_ESTABLISHED)
781 		return -ENOTCONN;
782 
783 	tls_build_proto(sk);
784 
785 	/* allocate tls context */
786 	write_lock_bh(&sk->sk_callback_lock);
787 	ctx = create_ctx(sk);
788 	if (!ctx) {
789 		rc = -ENOMEM;
790 		goto out;
791 	}
792 
793 	ctx->tx_conf = TLS_BASE;
794 	ctx->rx_conf = TLS_BASE;
795 	update_sk_prot(sk, ctx);
796 out:
797 	write_unlock_bh(&sk->sk_callback_lock);
798 	return rc;
799 }
800 
tls_update(struct sock * sk,struct proto * p,void (* write_space)(struct sock * sk))801 static void tls_update(struct sock *sk, struct proto *p,
802 		       void (*write_space)(struct sock *sk))
803 {
804 	struct tls_context *ctx;
805 
806 	ctx = tls_get_ctx(sk);
807 	if (likely(ctx)) {
808 		ctx->sk_write_space = write_space;
809 		ctx->sk_proto = p;
810 	} else {
811 		sk->sk_prot = p;
812 		sk->sk_write_space = write_space;
813 	}
814 }
815 
tls_get_info(const struct sock * sk,struct sk_buff * skb)816 static int tls_get_info(const struct sock *sk, struct sk_buff *skb)
817 {
818 	u16 version, cipher_type;
819 	struct tls_context *ctx;
820 	struct nlattr *start;
821 	int err;
822 
823 	start = nla_nest_start_noflag(skb, INET_ULP_INFO_TLS);
824 	if (!start)
825 		return -EMSGSIZE;
826 
827 	rcu_read_lock();
828 	ctx = rcu_dereference(inet_csk(sk)->icsk_ulp_data);
829 	if (!ctx) {
830 		err = 0;
831 		goto nla_failure;
832 	}
833 	version = ctx->prot_info.version;
834 	if (version) {
835 		err = nla_put_u16(skb, TLS_INFO_VERSION, version);
836 		if (err)
837 			goto nla_failure;
838 	}
839 	cipher_type = ctx->prot_info.cipher_type;
840 	if (cipher_type) {
841 		err = nla_put_u16(skb, TLS_INFO_CIPHER, cipher_type);
842 		if (err)
843 			goto nla_failure;
844 	}
845 	err = nla_put_u16(skb, TLS_INFO_TXCONF, tls_user_config(ctx, true));
846 	if (err)
847 		goto nla_failure;
848 
849 	err = nla_put_u16(skb, TLS_INFO_RXCONF, tls_user_config(ctx, false));
850 	if (err)
851 		goto nla_failure;
852 
853 	rcu_read_unlock();
854 	nla_nest_end(skb, start);
855 	return 0;
856 
857 nla_failure:
858 	rcu_read_unlock();
859 	nla_nest_cancel(skb, start);
860 	return err;
861 }
862 
tls_get_info_size(const struct sock * sk)863 static size_t tls_get_info_size(const struct sock *sk)
864 {
865 	size_t size = 0;
866 
867 	size += nla_total_size(0) +		/* INET_ULP_INFO_TLS */
868 		nla_total_size(sizeof(u16)) +	/* TLS_INFO_VERSION */
869 		nla_total_size(sizeof(u16)) +	/* TLS_INFO_CIPHER */
870 		nla_total_size(sizeof(u16)) +	/* TLS_INFO_RXCONF */
871 		nla_total_size(sizeof(u16)) +	/* TLS_INFO_TXCONF */
872 		0;
873 
874 	return size;
875 }
876 
tls_register_device(struct tls_device * device)877 void tls_register_device(struct tls_device *device)
878 {
879 	spin_lock_bh(&device_spinlock);
880 	list_add_tail(&device->dev_list, &device_list);
881 	spin_unlock_bh(&device_spinlock);
882 }
883 EXPORT_SYMBOL(tls_register_device);
884 
tls_unregister_device(struct tls_device * device)885 void tls_unregister_device(struct tls_device *device)
886 {
887 	spin_lock_bh(&device_spinlock);
888 	list_del(&device->dev_list);
889 	spin_unlock_bh(&device_spinlock);
890 }
891 EXPORT_SYMBOL(tls_unregister_device);
892 
893 static struct tcp_ulp_ops tcp_tls_ulp_ops __read_mostly = {
894 	.name			= "tls",
895 	.owner			= THIS_MODULE,
896 	.init			= tls_init,
897 	.update			= tls_update,
898 	.get_info		= tls_get_info,
899 	.get_info_size		= tls_get_info_size,
900 };
901 
tls_register(void)902 static int __init tls_register(void)
903 {
904 	tls_sw_proto_ops = inet_stream_ops;
905 	tls_sw_proto_ops.splice_read = tls_sw_splice_read;
906 	tls_sw_proto_ops.sendpage_locked   = tls_sw_sendpage_locked,
907 
908 	tls_device_init();
909 	tcp_register_ulp(&tcp_tls_ulp_ops);
910 
911 	return 0;
912 }
913 
tls_unregister(void)914 static void __exit tls_unregister(void)
915 {
916 	tcp_unregister_ulp(&tcp_tls_ulp_ops);
917 	tls_device_cleanup();
918 }
919 
920 module_init(tls_register);
921 module_exit(tls_unregister);
922