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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/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_proto_ops[TLS_NUM_PROTS][TLS_NUM_CONFIG][TLS_NUM_CONFIG];
65 static void build_protos(struct proto prot[TLS_NUM_CONFIG][TLS_NUM_CONFIG],
66 			 const struct proto *base);
67 
update_sk_prot(struct sock * sk,struct tls_context * ctx)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 	WRITE_ONCE(sk->sk_socket->ops,
75 		   &tls_proto_ops[ip_ver][ctx->tx_conf][ctx->rx_conf]);
76 }
77 
wait_on_pending_writer(struct sock * sk,long * timeo)78 int wait_on_pending_writer(struct sock *sk, long *timeo)
79 {
80 	int rc = 0;
81 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
82 
83 	add_wait_queue(sk_sleep(sk), &wait);
84 	while (1) {
85 		if (!*timeo) {
86 			rc = -EAGAIN;
87 			break;
88 		}
89 
90 		if (signal_pending(current)) {
91 			rc = sock_intr_errno(*timeo);
92 			break;
93 		}
94 
95 		if (sk_wait_event(sk, timeo,
96 				  !READ_ONCE(sk->sk_write_pending), &wait))
97 			break;
98 	}
99 	remove_wait_queue(sk_sleep(sk), &wait);
100 	return rc;
101 }
102 
tls_push_sg(struct sock * sk,struct tls_context * ctx,struct scatterlist * sg,u16 first_offset,int flags)103 int tls_push_sg(struct sock *sk,
104 		struct tls_context *ctx,
105 		struct scatterlist *sg,
106 		u16 first_offset,
107 		int flags)
108 {
109 	int sendpage_flags = flags | MSG_SENDPAGE_NOTLAST;
110 	int ret = 0;
111 	struct page *p;
112 	size_t size;
113 	int offset = first_offset;
114 
115 	size = sg->length - offset;
116 	offset += sg->offset;
117 
118 	ctx->in_tcp_sendpages = true;
119 	while (1) {
120 		if (sg_is_last(sg))
121 			sendpage_flags = flags;
122 
123 		/* is sending application-limited? */
124 		tcp_rate_check_app_limited(sk);
125 		p = sg_page(sg);
126 retry:
127 		ret = do_tcp_sendpages(sk, p, offset, size, sendpage_flags);
128 
129 		if (ret != size) {
130 			if (ret > 0) {
131 				offset += ret;
132 				size -= ret;
133 				goto retry;
134 			}
135 
136 			offset -= sg->offset;
137 			ctx->partially_sent_offset = offset;
138 			ctx->partially_sent_record = (void *)sg;
139 			ctx->in_tcp_sendpages = false;
140 			return ret;
141 		}
142 
143 		put_page(p);
144 		sk_mem_uncharge(sk, sg->length);
145 		sg = sg_next(sg);
146 		if (!sg)
147 			break;
148 
149 		offset = sg->offset;
150 		size = sg->length;
151 	}
152 
153 	ctx->in_tcp_sendpages = false;
154 
155 	return 0;
156 }
157 
tls_handle_open_record(struct sock * sk,int flags)158 static int tls_handle_open_record(struct sock *sk, int flags)
159 {
160 	struct tls_context *ctx = tls_get_ctx(sk);
161 
162 	if (tls_is_pending_open_record(ctx))
163 		return ctx->push_pending_record(sk, flags);
164 
165 	return 0;
166 }
167 
tls_proccess_cmsg(struct sock * sk,struct msghdr * msg,unsigned char * record_type)168 int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
169 		      unsigned char *record_type)
170 {
171 	struct cmsghdr *cmsg;
172 	int rc = -EINVAL;
173 
174 	for_each_cmsghdr(cmsg, msg) {
175 		if (!CMSG_OK(msg, cmsg))
176 			return -EINVAL;
177 		if (cmsg->cmsg_level != SOL_TLS)
178 			continue;
179 
180 		switch (cmsg->cmsg_type) {
181 		case TLS_SET_RECORD_TYPE:
182 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(*record_type)))
183 				return -EINVAL;
184 
185 			if (msg->msg_flags & MSG_MORE)
186 				return -EINVAL;
187 
188 			rc = tls_handle_open_record(sk, msg->msg_flags);
189 			if (rc)
190 				return rc;
191 
192 			*record_type = *(unsigned char *)CMSG_DATA(cmsg);
193 			rc = 0;
194 			break;
195 		default:
196 			return -EINVAL;
197 		}
198 	}
199 
200 	return rc;
201 }
202 
tls_push_partial_record(struct sock * sk,struct tls_context * ctx,int flags)203 int tls_push_partial_record(struct sock *sk, struct tls_context *ctx,
204 			    int flags)
205 {
206 	struct scatterlist *sg;
207 	u16 offset;
208 
209 	sg = ctx->partially_sent_record;
210 	offset = ctx->partially_sent_offset;
211 
212 	ctx->partially_sent_record = NULL;
213 	return tls_push_sg(sk, ctx, sg, offset, flags);
214 }
215 
tls_free_partial_record(struct sock * sk,struct tls_context * ctx)216 void tls_free_partial_record(struct sock *sk, struct tls_context *ctx)
217 {
218 	struct scatterlist *sg;
219 
220 	for (sg = ctx->partially_sent_record; sg; sg = sg_next(sg)) {
221 		put_page(sg_page(sg));
222 		sk_mem_uncharge(sk, sg->length);
223 	}
224 	ctx->partially_sent_record = NULL;
225 }
226 
tls_write_space(struct sock * sk)227 static void tls_write_space(struct sock *sk)
228 {
229 	struct tls_context *ctx = tls_get_ctx(sk);
230 
231 	/* If in_tcp_sendpages call lower protocol write space handler
232 	 * to ensure we wake up any waiting operations there. For example
233 	 * if do_tcp_sendpages where to call sk_wait_event.
234 	 */
235 	if (ctx->in_tcp_sendpages) {
236 		ctx->sk_write_space(sk);
237 		return;
238 	}
239 
240 #ifdef CONFIG_TLS_DEVICE
241 	if (ctx->tx_conf == TLS_HW)
242 		tls_device_write_space(sk, ctx);
243 	else
244 #endif
245 		tls_sw_write_space(sk, ctx);
246 
247 	ctx->sk_write_space(sk);
248 }
249 
250 /**
251  * tls_ctx_free() - free TLS ULP context
252  * @sk:  socket to with @ctx is attached
253  * @ctx: TLS context structure
254  *
255  * Free TLS context. If @sk is %NULL caller guarantees that the socket
256  * to which @ctx was attached has no outstanding references.
257  */
tls_ctx_free(struct sock * sk,struct tls_context * ctx)258 void tls_ctx_free(struct sock *sk, struct tls_context *ctx)
259 {
260 	if (!ctx)
261 		return;
262 
263 	memzero_explicit(&ctx->crypto_send, sizeof(ctx->crypto_send));
264 	memzero_explicit(&ctx->crypto_recv, sizeof(ctx->crypto_recv));
265 	mutex_destroy(&ctx->tx_lock);
266 
267 	if (sk)
268 		kfree_rcu(ctx, rcu);
269 	else
270 		kfree(ctx);
271 }
272 
tls_sk_proto_cleanup(struct sock * sk,struct tls_context * ctx,long timeo)273 static void tls_sk_proto_cleanup(struct sock *sk,
274 				 struct tls_context *ctx, long timeo)
275 {
276 	if (unlikely(sk->sk_write_pending) &&
277 	    !wait_on_pending_writer(sk, &timeo))
278 		tls_handle_open_record(sk, 0);
279 
280 	/* We need these for tls_sw_fallback handling of other packets */
281 	if (ctx->tx_conf == TLS_SW) {
282 		kfree(ctx->tx.rec_seq);
283 		kfree(ctx->tx.iv);
284 		tls_sw_release_resources_tx(sk);
285 		TLS_DEC_STATS(sock_net(sk), LINUX_MIB_TLSCURRTXSW);
286 	} else if (ctx->tx_conf == TLS_HW) {
287 		tls_device_free_resources_tx(sk);
288 		TLS_DEC_STATS(sock_net(sk), LINUX_MIB_TLSCURRTXDEVICE);
289 	}
290 
291 	if (ctx->rx_conf == TLS_SW) {
292 		tls_sw_release_resources_rx(sk);
293 		TLS_DEC_STATS(sock_net(sk), LINUX_MIB_TLSCURRRXSW);
294 	} else if (ctx->rx_conf == TLS_HW) {
295 		tls_device_offload_cleanup_rx(sk);
296 		TLS_DEC_STATS(sock_net(sk), LINUX_MIB_TLSCURRRXDEVICE);
297 	}
298 }
299 
tls_sk_proto_close(struct sock * sk,long timeout)300 static void tls_sk_proto_close(struct sock *sk, long timeout)
301 {
302 	struct inet_connection_sock *icsk = inet_csk(sk);
303 	struct tls_context *ctx = tls_get_ctx(sk);
304 	long timeo = sock_sndtimeo(sk, 0);
305 	bool free_ctx;
306 
307 	if (ctx->tx_conf == TLS_SW)
308 		tls_sw_cancel_work_tx(ctx);
309 
310 	lock_sock(sk);
311 	free_ctx = ctx->tx_conf != TLS_HW && ctx->rx_conf != TLS_HW;
312 
313 	if (ctx->tx_conf != TLS_BASE || ctx->rx_conf != TLS_BASE)
314 		tls_sk_proto_cleanup(sk, ctx, timeo);
315 
316 	write_lock_bh(&sk->sk_callback_lock);
317 	if (free_ctx)
318 		rcu_assign_pointer(icsk->icsk_ulp_data, NULL);
319 	WRITE_ONCE(sk->sk_prot, ctx->sk_proto);
320 	if (sk->sk_write_space == tls_write_space)
321 		sk->sk_write_space = ctx->sk_write_space;
322 	write_unlock_bh(&sk->sk_callback_lock);
323 	release_sock(sk);
324 	if (ctx->tx_conf == TLS_SW)
325 		tls_sw_free_ctx_tx(ctx);
326 	if (ctx->rx_conf == TLS_SW || ctx->rx_conf == TLS_HW)
327 		tls_sw_strparser_done(ctx);
328 	if (ctx->rx_conf == TLS_SW)
329 		tls_sw_free_ctx_rx(ctx);
330 	ctx->sk_proto->close(sk, timeout);
331 
332 	if (free_ctx)
333 		tls_ctx_free(sk, ctx);
334 }
335 
do_tls_getsockopt_conf(struct sock * sk,char __user * optval,int __user * optlen,int tx)336 static int do_tls_getsockopt_conf(struct sock *sk, char __user *optval,
337 				  int __user *optlen, int tx)
338 {
339 	int rc = 0;
340 	struct tls_context *ctx = tls_get_ctx(sk);
341 	struct tls_crypto_info *crypto_info;
342 	struct cipher_context *cctx;
343 	int len;
344 
345 	if (get_user(len, optlen))
346 		return -EFAULT;
347 
348 	if (!optval || (len < sizeof(*crypto_info))) {
349 		rc = -EINVAL;
350 		goto out;
351 	}
352 
353 	if (!ctx) {
354 		rc = -EBUSY;
355 		goto out;
356 	}
357 
358 	/* get user crypto info */
359 	if (tx) {
360 		crypto_info = &ctx->crypto_send.info;
361 		cctx = &ctx->tx;
362 	} else {
363 		crypto_info = &ctx->crypto_recv.info;
364 		cctx = &ctx->rx;
365 	}
366 
367 	if (!TLS_CRYPTO_INFO_READY(crypto_info)) {
368 		rc = -EBUSY;
369 		goto out;
370 	}
371 
372 	if (len == sizeof(*crypto_info)) {
373 		if (copy_to_user(optval, crypto_info, sizeof(*crypto_info)))
374 			rc = -EFAULT;
375 		goto out;
376 	}
377 
378 	switch (crypto_info->cipher_type) {
379 	case TLS_CIPHER_AES_GCM_128: {
380 		struct tls12_crypto_info_aes_gcm_128 *
381 		  crypto_info_aes_gcm_128 =
382 		  container_of(crypto_info,
383 			       struct tls12_crypto_info_aes_gcm_128,
384 			       info);
385 
386 		if (len != sizeof(*crypto_info_aes_gcm_128)) {
387 			rc = -EINVAL;
388 			goto out;
389 		}
390 		memcpy(crypto_info_aes_gcm_128->iv,
391 		       cctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
392 		       TLS_CIPHER_AES_GCM_128_IV_SIZE);
393 		memcpy(crypto_info_aes_gcm_128->rec_seq, cctx->rec_seq,
394 		       TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE);
395 		if (copy_to_user(optval,
396 				 crypto_info_aes_gcm_128,
397 				 sizeof(*crypto_info_aes_gcm_128)))
398 			rc = -EFAULT;
399 		break;
400 	}
401 	case TLS_CIPHER_AES_GCM_256: {
402 		struct tls12_crypto_info_aes_gcm_256 *
403 		  crypto_info_aes_gcm_256 =
404 		  container_of(crypto_info,
405 			       struct tls12_crypto_info_aes_gcm_256,
406 			       info);
407 
408 		if (len != sizeof(*crypto_info_aes_gcm_256)) {
409 			rc = -EINVAL;
410 			goto out;
411 		}
412 		memcpy(crypto_info_aes_gcm_256->iv,
413 		       cctx->iv + TLS_CIPHER_AES_GCM_256_SALT_SIZE,
414 		       TLS_CIPHER_AES_GCM_256_IV_SIZE);
415 		memcpy(crypto_info_aes_gcm_256->rec_seq, cctx->rec_seq,
416 		       TLS_CIPHER_AES_GCM_256_REC_SEQ_SIZE);
417 		if (copy_to_user(optval,
418 				 crypto_info_aes_gcm_256,
419 				 sizeof(*crypto_info_aes_gcm_256)))
420 			rc = -EFAULT;
421 		break;
422 	}
423 	default:
424 		rc = -EINVAL;
425 	}
426 
427 out:
428 	return rc;
429 }
430 
do_tls_getsockopt(struct sock * sk,int optname,char __user * optval,int __user * optlen)431 static int do_tls_getsockopt(struct sock *sk, int optname,
432 			     char __user *optval, int __user *optlen)
433 {
434 	int rc = 0;
435 
436 	lock_sock(sk);
437 
438 	switch (optname) {
439 	case TLS_TX:
440 	case TLS_RX:
441 		rc = do_tls_getsockopt_conf(sk, optval, optlen,
442 					    optname == TLS_TX);
443 		break;
444 	default:
445 		rc = -ENOPROTOOPT;
446 		break;
447 	}
448 
449 	release_sock(sk);
450 
451 	return rc;
452 }
453 
tls_getsockopt(struct sock * sk,int level,int optname,char __user * optval,int __user * optlen)454 static int tls_getsockopt(struct sock *sk, int level, int optname,
455 			  char __user *optval, int __user *optlen)
456 {
457 	struct tls_context *ctx = tls_get_ctx(sk);
458 
459 	if (level != SOL_TLS)
460 		return ctx->sk_proto->getsockopt(sk, level,
461 						 optname, optval, optlen);
462 
463 	return do_tls_getsockopt(sk, optname, optval, optlen);
464 }
465 
do_tls_setsockopt_conf(struct sock * sk,sockptr_t optval,unsigned int optlen,int tx)466 static int do_tls_setsockopt_conf(struct sock *sk, sockptr_t optval,
467 				  unsigned int optlen, int tx)
468 {
469 	struct tls_crypto_info *crypto_info;
470 	struct tls_crypto_info *alt_crypto_info;
471 	struct tls_context *ctx = tls_get_ctx(sk);
472 	size_t optsize;
473 	int rc = 0;
474 	int conf;
475 
476 	if (sockptr_is_null(optval) || (optlen < sizeof(*crypto_info))) {
477 		rc = -EINVAL;
478 		goto out;
479 	}
480 
481 	if (tx) {
482 		crypto_info = &ctx->crypto_send.info;
483 		alt_crypto_info = &ctx->crypto_recv.info;
484 	} else {
485 		crypto_info = &ctx->crypto_recv.info;
486 		alt_crypto_info = &ctx->crypto_send.info;
487 	}
488 
489 	/* Currently we don't support set crypto info more than one time */
490 	if (TLS_CRYPTO_INFO_READY(crypto_info)) {
491 		rc = -EBUSY;
492 		goto out;
493 	}
494 
495 	rc = copy_from_sockptr(crypto_info, optval, sizeof(*crypto_info));
496 	if (rc) {
497 		rc = -EFAULT;
498 		goto err_crypto_info;
499 	}
500 
501 	/* check version */
502 	if (crypto_info->version != TLS_1_2_VERSION &&
503 	    crypto_info->version != TLS_1_3_VERSION) {
504 		rc = -EINVAL;
505 		goto err_crypto_info;
506 	}
507 
508 	/* Ensure that TLS version and ciphers are same in both directions */
509 	if (TLS_CRYPTO_INFO_READY(alt_crypto_info)) {
510 		if (alt_crypto_info->version != crypto_info->version ||
511 		    alt_crypto_info->cipher_type != crypto_info->cipher_type) {
512 			rc = -EINVAL;
513 			goto err_crypto_info;
514 		}
515 	}
516 
517 	switch (crypto_info->cipher_type) {
518 	case TLS_CIPHER_AES_GCM_128:
519 		optsize = sizeof(struct tls12_crypto_info_aes_gcm_128);
520 		break;
521 	case TLS_CIPHER_AES_GCM_256: {
522 		optsize = sizeof(struct tls12_crypto_info_aes_gcm_256);
523 		break;
524 	}
525 	case TLS_CIPHER_AES_CCM_128:
526 		optsize = sizeof(struct tls12_crypto_info_aes_ccm_128);
527 		break;
528 	case TLS_CIPHER_CHACHA20_POLY1305:
529 		optsize = sizeof(struct tls12_crypto_info_chacha20_poly1305);
530 		break;
531 	default:
532 		rc = -EINVAL;
533 		goto err_crypto_info;
534 	}
535 
536 	if (optlen != optsize) {
537 		rc = -EINVAL;
538 		goto err_crypto_info;
539 	}
540 
541 	rc = copy_from_sockptr_offset(crypto_info + 1, optval,
542 				      sizeof(*crypto_info),
543 				      optlen - sizeof(*crypto_info));
544 	if (rc) {
545 		rc = -EFAULT;
546 		goto err_crypto_info;
547 	}
548 
549 	if (tx) {
550 		rc = tls_set_device_offload(sk, ctx);
551 		conf = TLS_HW;
552 		if (!rc) {
553 			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSTXDEVICE);
554 			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSCURRTXDEVICE);
555 		} else {
556 			rc = tls_set_sw_offload(sk, ctx, 1);
557 			if (rc)
558 				goto err_crypto_info;
559 			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSTXSW);
560 			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSCURRTXSW);
561 			conf = TLS_SW;
562 		}
563 	} else {
564 		rc = tls_set_device_offload_rx(sk, ctx);
565 		conf = TLS_HW;
566 		if (!rc) {
567 			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSRXDEVICE);
568 			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSCURRRXDEVICE);
569 		} else {
570 			rc = tls_set_sw_offload(sk, ctx, 0);
571 			if (rc)
572 				goto err_crypto_info;
573 			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSRXSW);
574 			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSCURRRXSW);
575 			conf = TLS_SW;
576 		}
577 		tls_sw_strparser_arm(sk, ctx);
578 	}
579 
580 	if (tx)
581 		ctx->tx_conf = conf;
582 	else
583 		ctx->rx_conf = conf;
584 	update_sk_prot(sk, ctx);
585 	if (tx) {
586 		ctx->sk_write_space = sk->sk_write_space;
587 		sk->sk_write_space = tls_write_space;
588 	}
589 	goto out;
590 
591 err_crypto_info:
592 	memzero_explicit(crypto_info, sizeof(union tls_crypto_context));
593 out:
594 	return rc;
595 }
596 
do_tls_setsockopt(struct sock * sk,int optname,sockptr_t optval,unsigned int optlen)597 static int do_tls_setsockopt(struct sock *sk, int optname, sockptr_t optval,
598 			     unsigned int optlen)
599 {
600 	int rc = 0;
601 
602 	switch (optname) {
603 	case TLS_TX:
604 	case TLS_RX:
605 		lock_sock(sk);
606 		rc = do_tls_setsockopt_conf(sk, optval, optlen,
607 					    optname == TLS_TX);
608 		release_sock(sk);
609 		break;
610 	default:
611 		rc = -ENOPROTOOPT;
612 		break;
613 	}
614 	return rc;
615 }
616 
tls_setsockopt(struct sock * sk,int level,int optname,sockptr_t optval,unsigned int optlen)617 static int tls_setsockopt(struct sock *sk, int level, int optname,
618 			  sockptr_t optval, unsigned int optlen)
619 {
620 	struct tls_context *ctx = tls_get_ctx(sk);
621 
622 	if (level != SOL_TLS)
623 		return ctx->sk_proto->setsockopt(sk, level, optname, optval,
624 						 optlen);
625 
626 	return do_tls_setsockopt(sk, optname, optval, optlen);
627 }
628 
tls_ctx_create(struct sock * sk)629 struct tls_context *tls_ctx_create(struct sock *sk)
630 {
631 	struct inet_connection_sock *icsk = inet_csk(sk);
632 	struct tls_context *ctx;
633 
634 	ctx = kzalloc(sizeof(*ctx), GFP_ATOMIC);
635 	if (!ctx)
636 		return NULL;
637 
638 	mutex_init(&ctx->tx_lock);
639 	rcu_assign_pointer(icsk->icsk_ulp_data, ctx);
640 	ctx->sk_proto = READ_ONCE(sk->sk_prot);
641 	ctx->sk = sk;
642 	return ctx;
643 }
644 
build_proto_ops(struct proto_ops ops[TLS_NUM_CONFIG][TLS_NUM_CONFIG],const struct proto_ops * base)645 static void build_proto_ops(struct proto_ops ops[TLS_NUM_CONFIG][TLS_NUM_CONFIG],
646 			    const struct proto_ops *base)
647 {
648 	ops[TLS_BASE][TLS_BASE] = *base;
649 
650 	ops[TLS_SW  ][TLS_BASE] = ops[TLS_BASE][TLS_BASE];
651 	ops[TLS_SW  ][TLS_BASE].sendpage_locked	= tls_sw_sendpage_locked;
652 
653 	ops[TLS_BASE][TLS_SW  ] = ops[TLS_BASE][TLS_BASE];
654 	ops[TLS_BASE][TLS_SW  ].splice_read	= tls_sw_splice_read;
655 
656 	ops[TLS_SW  ][TLS_SW  ] = ops[TLS_SW  ][TLS_BASE];
657 	ops[TLS_SW  ][TLS_SW  ].splice_read	= tls_sw_splice_read;
658 
659 #ifdef CONFIG_TLS_DEVICE
660 	ops[TLS_HW  ][TLS_BASE] = ops[TLS_BASE][TLS_BASE];
661 	ops[TLS_HW  ][TLS_BASE].sendpage_locked	= NULL;
662 
663 	ops[TLS_HW  ][TLS_SW  ] = ops[TLS_BASE][TLS_SW  ];
664 	ops[TLS_HW  ][TLS_SW  ].sendpage_locked	= NULL;
665 
666 	ops[TLS_BASE][TLS_HW  ] = ops[TLS_BASE][TLS_SW  ];
667 
668 	ops[TLS_SW  ][TLS_HW  ] = ops[TLS_SW  ][TLS_SW  ];
669 
670 	ops[TLS_HW  ][TLS_HW  ] = ops[TLS_HW  ][TLS_SW  ];
671 	ops[TLS_HW  ][TLS_HW  ].sendpage_locked	= NULL;
672 #endif
673 #ifdef CONFIG_TLS_TOE
674 	ops[TLS_HW_RECORD][TLS_HW_RECORD] = *base;
675 #endif
676 }
677 
tls_build_proto(struct sock * sk)678 static void tls_build_proto(struct sock *sk)
679 {
680 	int ip_ver = sk->sk_family == AF_INET6 ? TLSV6 : TLSV4;
681 	struct proto *prot = READ_ONCE(sk->sk_prot);
682 
683 	/* Build IPv6 TLS whenever the address of tcpv6 _prot changes */
684 	if (ip_ver == TLSV6 &&
685 	    unlikely(prot != smp_load_acquire(&saved_tcpv6_prot))) {
686 		mutex_lock(&tcpv6_prot_mutex);
687 		if (likely(prot != saved_tcpv6_prot)) {
688 			build_protos(tls_prots[TLSV6], prot);
689 			build_proto_ops(tls_proto_ops[TLSV6],
690 					sk->sk_socket->ops);
691 			smp_store_release(&saved_tcpv6_prot, prot);
692 		}
693 		mutex_unlock(&tcpv6_prot_mutex);
694 	}
695 
696 	if (ip_ver == TLSV4 &&
697 	    unlikely(prot != smp_load_acquire(&saved_tcpv4_prot))) {
698 		mutex_lock(&tcpv4_prot_mutex);
699 		if (likely(prot != saved_tcpv4_prot)) {
700 			build_protos(tls_prots[TLSV4], prot);
701 			build_proto_ops(tls_proto_ops[TLSV4],
702 					sk->sk_socket->ops);
703 			smp_store_release(&saved_tcpv4_prot, prot);
704 		}
705 		mutex_unlock(&tcpv4_prot_mutex);
706 	}
707 }
708 
build_protos(struct proto prot[TLS_NUM_CONFIG][TLS_NUM_CONFIG],const struct proto * base)709 static void build_protos(struct proto prot[TLS_NUM_CONFIG][TLS_NUM_CONFIG],
710 			 const struct proto *base)
711 {
712 	prot[TLS_BASE][TLS_BASE] = *base;
713 	prot[TLS_BASE][TLS_BASE].setsockopt	= tls_setsockopt;
714 	prot[TLS_BASE][TLS_BASE].getsockopt	= tls_getsockopt;
715 	prot[TLS_BASE][TLS_BASE].close		= tls_sk_proto_close;
716 
717 	prot[TLS_SW][TLS_BASE] = prot[TLS_BASE][TLS_BASE];
718 	prot[TLS_SW][TLS_BASE].sendmsg		= tls_sw_sendmsg;
719 	prot[TLS_SW][TLS_BASE].sendpage		= tls_sw_sendpage;
720 
721 	prot[TLS_BASE][TLS_SW] = prot[TLS_BASE][TLS_BASE];
722 	prot[TLS_BASE][TLS_SW].recvmsg		  = tls_sw_recvmsg;
723 	prot[TLS_BASE][TLS_SW].sock_is_readable   = tls_sw_sock_is_readable;
724 	prot[TLS_BASE][TLS_SW].close		  = tls_sk_proto_close;
725 
726 	prot[TLS_SW][TLS_SW] = prot[TLS_SW][TLS_BASE];
727 	prot[TLS_SW][TLS_SW].recvmsg		= tls_sw_recvmsg;
728 	prot[TLS_SW][TLS_SW].sock_is_readable   = tls_sw_sock_is_readable;
729 	prot[TLS_SW][TLS_SW].close		= tls_sk_proto_close;
730 
731 #ifdef CONFIG_TLS_DEVICE
732 	prot[TLS_HW][TLS_BASE] = prot[TLS_BASE][TLS_BASE];
733 	prot[TLS_HW][TLS_BASE].sendmsg		= tls_device_sendmsg;
734 	prot[TLS_HW][TLS_BASE].sendpage		= tls_device_sendpage;
735 
736 	prot[TLS_HW][TLS_SW] = prot[TLS_BASE][TLS_SW];
737 	prot[TLS_HW][TLS_SW].sendmsg		= tls_device_sendmsg;
738 	prot[TLS_HW][TLS_SW].sendpage		= tls_device_sendpage;
739 
740 	prot[TLS_BASE][TLS_HW] = prot[TLS_BASE][TLS_SW];
741 
742 	prot[TLS_SW][TLS_HW] = prot[TLS_SW][TLS_SW];
743 
744 	prot[TLS_HW][TLS_HW] = prot[TLS_HW][TLS_SW];
745 #endif
746 #ifdef CONFIG_TLS_TOE
747 	prot[TLS_HW_RECORD][TLS_HW_RECORD] = *base;
748 	prot[TLS_HW_RECORD][TLS_HW_RECORD].hash		= tls_toe_hash;
749 	prot[TLS_HW_RECORD][TLS_HW_RECORD].unhash	= tls_toe_unhash;
750 #endif
751 }
752 
tls_init(struct sock * sk)753 static int tls_init(struct sock *sk)
754 {
755 	struct tls_context *ctx;
756 	int rc = 0;
757 
758 	tls_build_proto(sk);
759 
760 #ifdef CONFIG_TLS_TOE
761 	if (tls_toe_bypass(sk))
762 		return 0;
763 #endif
764 
765 	/* The TLS ulp is currently supported only for TCP sockets
766 	 * in ESTABLISHED state.
767 	 * Supporting sockets in LISTEN state will require us
768 	 * to modify the accept implementation to clone rather then
769 	 * share the ulp context.
770 	 */
771 	if (sk->sk_state != TCP_ESTABLISHED)
772 		return -ENOTCONN;
773 
774 	/* allocate tls context */
775 	write_lock_bh(&sk->sk_callback_lock);
776 	ctx = tls_ctx_create(sk);
777 	if (!ctx) {
778 		rc = -ENOMEM;
779 		goto out;
780 	}
781 
782 	ctx->tx_conf = TLS_BASE;
783 	ctx->rx_conf = TLS_BASE;
784 	update_sk_prot(sk, ctx);
785 out:
786 	write_unlock_bh(&sk->sk_callback_lock);
787 	return rc;
788 }
789 
tls_update(struct sock * sk,struct proto * p,void (* write_space)(struct sock * sk))790 static void tls_update(struct sock *sk, struct proto *p,
791 		       void (*write_space)(struct sock *sk))
792 {
793 	struct tls_context *ctx;
794 
795 	WARN_ON_ONCE(sk->sk_prot == p);
796 
797 	ctx = tls_get_ctx(sk);
798 	if (likely(ctx)) {
799 		ctx->sk_write_space = write_space;
800 		ctx->sk_proto = p;
801 	} else {
802 		/* Pairs with lockless read in sk_clone_lock(). */
803 		WRITE_ONCE(sk->sk_prot, p);
804 		sk->sk_write_space = write_space;
805 	}
806 }
807 
tls_get_info(const struct sock * sk,struct sk_buff * skb)808 static int tls_get_info(const struct sock *sk, struct sk_buff *skb)
809 {
810 	u16 version, cipher_type;
811 	struct tls_context *ctx;
812 	struct nlattr *start;
813 	int err;
814 
815 	start = nla_nest_start_noflag(skb, INET_ULP_INFO_TLS);
816 	if (!start)
817 		return -EMSGSIZE;
818 
819 	rcu_read_lock();
820 	ctx = rcu_dereference(inet_csk(sk)->icsk_ulp_data);
821 	if (!ctx) {
822 		err = 0;
823 		goto nla_failure;
824 	}
825 	version = ctx->prot_info.version;
826 	if (version) {
827 		err = nla_put_u16(skb, TLS_INFO_VERSION, version);
828 		if (err)
829 			goto nla_failure;
830 	}
831 	cipher_type = ctx->prot_info.cipher_type;
832 	if (cipher_type) {
833 		err = nla_put_u16(skb, TLS_INFO_CIPHER, cipher_type);
834 		if (err)
835 			goto nla_failure;
836 	}
837 	err = nla_put_u16(skb, TLS_INFO_TXCONF, tls_user_config(ctx, true));
838 	if (err)
839 		goto nla_failure;
840 
841 	err = nla_put_u16(skb, TLS_INFO_RXCONF, tls_user_config(ctx, false));
842 	if (err)
843 		goto nla_failure;
844 
845 	rcu_read_unlock();
846 	nla_nest_end(skb, start);
847 	return 0;
848 
849 nla_failure:
850 	rcu_read_unlock();
851 	nla_nest_cancel(skb, start);
852 	return err;
853 }
854 
tls_get_info_size(const struct sock * sk)855 static size_t tls_get_info_size(const struct sock *sk)
856 {
857 	size_t size = 0;
858 
859 	size += nla_total_size(0) +		/* INET_ULP_INFO_TLS */
860 		nla_total_size(sizeof(u16)) +	/* TLS_INFO_VERSION */
861 		nla_total_size(sizeof(u16)) +	/* TLS_INFO_CIPHER */
862 		nla_total_size(sizeof(u16)) +	/* TLS_INFO_RXCONF */
863 		nla_total_size(sizeof(u16)) +	/* TLS_INFO_TXCONF */
864 		0;
865 
866 	return size;
867 }
868 
tls_init_net(struct net * net)869 static int __net_init tls_init_net(struct net *net)
870 {
871 	int err;
872 
873 	net->mib.tls_statistics = alloc_percpu(struct linux_tls_mib);
874 	if (!net->mib.tls_statistics)
875 		return -ENOMEM;
876 
877 	err = tls_proc_init(net);
878 	if (err)
879 		goto err_free_stats;
880 
881 	return 0;
882 err_free_stats:
883 	free_percpu(net->mib.tls_statistics);
884 	return err;
885 }
886 
tls_exit_net(struct net * net)887 static void __net_exit tls_exit_net(struct net *net)
888 {
889 	tls_proc_fini(net);
890 	free_percpu(net->mib.tls_statistics);
891 }
892 
893 static struct pernet_operations tls_proc_ops = {
894 	.init = tls_init_net,
895 	.exit = tls_exit_net,
896 };
897 
898 static struct tcp_ulp_ops tcp_tls_ulp_ops __read_mostly = {
899 	.name			= "tls",
900 	.owner			= THIS_MODULE,
901 	.init			= tls_init,
902 	.update			= tls_update,
903 	.get_info		= tls_get_info,
904 	.get_info_size		= tls_get_info_size,
905 };
906 
tls_register(void)907 static int __init tls_register(void)
908 {
909 	int err;
910 
911 	err = register_pernet_subsys(&tls_proc_ops);
912 	if (err)
913 		return err;
914 
915 	err = tls_device_init();
916 	if (err) {
917 		unregister_pernet_subsys(&tls_proc_ops);
918 		return err;
919 	}
920 
921 	tcp_register_ulp(&tcp_tls_ulp_ops);
922 
923 	return 0;
924 }
925 
tls_unregister(void)926 static void __exit tls_unregister(void)
927 {
928 	tcp_unregister_ulp(&tcp_tls_ulp_ops);
929 	tls_device_cleanup();
930 	unregister_pernet_subsys(&tls_proc_ops);
931 }
932 
933 module_init(tls_register);
934 module_exit(tls_unregister);
935