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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
 43#include <net/tls.h>
 44
 45MODULE_AUTHOR("Mellanox Technologies");
 46MODULE_DESCRIPTION("Transport Layer Security Support");
 47MODULE_LICENSE("Dual BSD/GPL");
 48
 49enum {
 50	TLSV4,
 51	TLSV6,
 52	TLS_NUM_PROTS,
 53};
 54
 55enum {
 56	TLS_BASE,
 57	TLS_SW_TX,
 58	TLS_SW_RX,
 59	TLS_SW_RXTX,
 60	TLS_HW_RECORD,
 61	TLS_NUM_CONFIG,
 62};
 63
 64static struct proto *saved_tcpv6_prot;
 65static DEFINE_MUTEX(tcpv6_prot_mutex);
 66static LIST_HEAD(device_list);
 67static DEFINE_MUTEX(device_mutex);
 68static struct proto tls_prots[TLS_NUM_PROTS][TLS_NUM_CONFIG];
 69static struct proto_ops tls_sw_proto_ops;
 70
 71static inline void update_sk_prot(struct sock *sk, struct tls_context *ctx)
 72{
 73	int ip_ver = sk->sk_family == AF_INET6 ? TLSV6 : TLSV4;
 74
 75	sk->sk_prot = &tls_prots[ip_ver][ctx->conf];
 76}
 77
 78int 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, !sk->sk_write_pending, &wait))
 96			break;
 97	}
 98	remove_wait_queue(sk_sleep(sk), &wait);
 99	return rc;
100}
101
102int tls_push_sg(struct sock *sk,
103		struct tls_context *ctx,
104		struct scatterlist *sg,
105		u16 first_offset,
106		int flags)
107{
108	int sendpage_flags = flags | MSG_SENDPAGE_NOTLAST;
109	int ret = 0;
110	struct page *p;
111	size_t size;
112	int offset = first_offset;
113
114	size = sg->length - offset;
115	offset += sg->offset;
116
117	ctx->in_tcp_sendpages = true;
118	while (1) {
119		if (sg_is_last(sg))
120			sendpage_flags = flags;
121
122		/* is sending application-limited? */
123		tcp_rate_check_app_limited(sk);
124		p = sg_page(sg);
125retry:
126		ret = do_tcp_sendpages(sk, p, offset, size, sendpage_flags);
127
128		if (ret != size) {
129			if (ret > 0) {
130				offset += ret;
131				size -= ret;
132				goto retry;
133			}
134
135			offset -= sg->offset;
136			ctx->partially_sent_offset = offset;
137			ctx->partially_sent_record = (void *)sg;
138			ctx->in_tcp_sendpages = false;
139			return ret;
140		}
141
142		put_page(p);
143		sk_mem_uncharge(sk, sg->length);
144		sg = sg_next(sg);
145		if (!sg)
146			break;
147
148		offset = sg->offset;
149		size = sg->length;
150	}
151
152	clear_bit(TLS_PENDING_CLOSED_RECORD, &ctx->flags);
153	ctx->in_tcp_sendpages = false;
154	ctx->sk_write_space(sk);
155
156	return 0;
157}
158
159static int tls_handle_open_record(struct sock *sk, int flags)
160{
161	struct tls_context *ctx = tls_get_ctx(sk);
162
163	if (tls_is_pending_open_record(ctx))
164		return ctx->push_pending_record(sk, flags);
165
166	return 0;
167}
168
169int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
170		      unsigned char *record_type)
171{
172	struct cmsghdr *cmsg;
173	int rc = -EINVAL;
174
175	for_each_cmsghdr(cmsg, msg) {
176		if (!CMSG_OK(msg, cmsg))
177			return -EINVAL;
178		if (cmsg->cmsg_level != SOL_TLS)
179			continue;
180
181		switch (cmsg->cmsg_type) {
182		case TLS_SET_RECORD_TYPE:
183			if (cmsg->cmsg_len < CMSG_LEN(sizeof(*record_type)))
184				return -EINVAL;
185
186			if (msg->msg_flags & MSG_MORE)
187				return -EINVAL;
188
189			rc = tls_handle_open_record(sk, msg->msg_flags);
190			if (rc)
191				return rc;
192
193			*record_type = *(unsigned char *)CMSG_DATA(cmsg);
194			rc = 0;
195			break;
196		default:
197			return -EINVAL;
198		}
199	}
200
201	return rc;
202}
203
204int tls_push_pending_closed_record(struct sock *sk, struct tls_context *ctx,
205				   int flags, long *timeo)
206{
207	struct scatterlist *sg;
208	u16 offset;
209
210	if (!tls_is_partially_sent_record(ctx))
211		return ctx->push_pending_record(sk, flags);
212
213	sg = ctx->partially_sent_record;
214	offset = ctx->partially_sent_offset;
215
216	ctx->partially_sent_record = NULL;
217	return tls_push_sg(sk, ctx, sg, offset, flags);
218}
219
220static void tls_write_space(struct sock *sk)
221{
222	struct tls_context *ctx = tls_get_ctx(sk);
223
224	/* We are already sending pages, ignore notification */
225	if (ctx->in_tcp_sendpages)
226		return;
227
228	if (!sk->sk_write_pending && tls_is_pending_closed_record(ctx)) {
229		gfp_t sk_allocation = sk->sk_allocation;
230		int rc;
231		long timeo = 0;
232
233		sk->sk_allocation = GFP_ATOMIC;
234		rc = tls_push_pending_closed_record(sk, ctx,
235						    MSG_DONTWAIT |
236						    MSG_NOSIGNAL,
237						    &timeo);
238		sk->sk_allocation = sk_allocation;
239
240		if (rc < 0)
241			return;
242	}
243
244	ctx->sk_write_space(sk);
245}
246
247static void tls_sk_proto_close(struct sock *sk, long timeout)
248{
249	struct tls_context *ctx = tls_get_ctx(sk);
250	long timeo = sock_sndtimeo(sk, 0);
251	void (*sk_proto_close)(struct sock *sk, long timeout);
252	bool free_ctx = false;
253
254	lock_sock(sk);
255	sk_proto_close = ctx->sk_proto_close;
256
257	if (ctx->conf == TLS_BASE || ctx->conf == TLS_HW_RECORD) {
258		free_ctx = true;
259		goto skip_tx_cleanup;
260	}
261
262	if (!tls_complete_pending_work(sk, ctx, 0, &timeo))
263		tls_handle_open_record(sk, 0);
264
265	if (ctx->partially_sent_record) {
266		struct scatterlist *sg = ctx->partially_sent_record;
267
268		while (1) {
269			put_page(sg_page(sg));
270			sk_mem_uncharge(sk, sg->length);
271
272			if (sg_is_last(sg))
273				break;
274			sg++;
275		}
276	}
277
278	kfree(ctx->tx.rec_seq);
279	kfree(ctx->tx.iv);
280	kfree(ctx->rx.rec_seq);
281	kfree(ctx->rx.iv);
282
283	if (ctx->conf == TLS_SW_TX ||
284	    ctx->conf == TLS_SW_RX ||
285	    ctx->conf == TLS_SW_RXTX) {
286		tls_sw_free_resources(sk);
287	}
288
289skip_tx_cleanup:
290	release_sock(sk);
291	sk_proto_close(sk, timeout);
292	/* free ctx for TLS_HW_RECORD, used by tcp_set_state
293	 * for sk->sk_prot->unhash [tls_hw_unhash]
294	 */
295	if (free_ctx)
296		kfree(ctx);
297}
298
299static int do_tls_getsockopt_tx(struct sock *sk, char __user *optval,
300				int __user *optlen)
301{
302	int rc = 0;
303	struct tls_context *ctx = tls_get_ctx(sk);
304	struct tls_crypto_info *crypto_info;
305	int len;
306
307	if (get_user(len, optlen))
308		return -EFAULT;
309
310	if (!optval || (len < sizeof(*crypto_info))) {
311		rc = -EINVAL;
312		goto out;
313	}
314
315	if (!ctx) {
316		rc = -EBUSY;
317		goto out;
318	}
319
320	/* get user crypto info */
321	crypto_info = &ctx->crypto_send;
322
323	if (!TLS_CRYPTO_INFO_READY(crypto_info)) {
324		rc = -EBUSY;
325		goto out;
326	}
327
328	if (len == sizeof(*crypto_info)) {
329		if (copy_to_user(optval, crypto_info, sizeof(*crypto_info)))
330			rc = -EFAULT;
331		goto out;
332	}
333
334	switch (crypto_info->cipher_type) {
335	case TLS_CIPHER_AES_GCM_128: {
336		struct tls12_crypto_info_aes_gcm_128 *
337		  crypto_info_aes_gcm_128 =
338		  container_of(crypto_info,
339			       struct tls12_crypto_info_aes_gcm_128,
340			       info);
341
342		if (len != sizeof(*crypto_info_aes_gcm_128)) {
343			rc = -EINVAL;
344			goto out;
345		}
346		lock_sock(sk);
347		memcpy(crypto_info_aes_gcm_128->iv,
348		       ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
349		       TLS_CIPHER_AES_GCM_128_IV_SIZE);
350		memcpy(crypto_info_aes_gcm_128->rec_seq, ctx->tx.rec_seq,
351		       TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE);
352		release_sock(sk);
353		if (copy_to_user(optval,
354				 crypto_info_aes_gcm_128,
355				 sizeof(*crypto_info_aes_gcm_128)))
356			rc = -EFAULT;
357		break;
358	}
359	default:
360		rc = -EINVAL;
361	}
362
363out:
364	return rc;
365}
366
367static int do_tls_getsockopt(struct sock *sk, int optname,
368			     char __user *optval, int __user *optlen)
369{
370	int rc = 0;
371
372	switch (optname) {
373	case TLS_TX:
374		rc = do_tls_getsockopt_tx(sk, optval, optlen);
375		break;
376	default:
377		rc = -ENOPROTOOPT;
378		break;
379	}
380	return rc;
381}
382
383static int tls_getsockopt(struct sock *sk, int level, int optname,
384			  char __user *optval, int __user *optlen)
385{
386	struct tls_context *ctx = tls_get_ctx(sk);
387
388	if (level != SOL_TLS)
389		return ctx->getsockopt(sk, level, optname, optval, optlen);
390
391	return do_tls_getsockopt(sk, optname, optval, optlen);
392}
393
394static int do_tls_setsockopt_conf(struct sock *sk, char __user *optval,
395				  unsigned int optlen, int tx)
396{
397	struct tls_crypto_info *crypto_info;
398	struct tls_context *ctx = tls_get_ctx(sk);
399	int rc = 0;
400	int conf;
401
402	if (!optval || (optlen < sizeof(*crypto_info))) {
403		rc = -EINVAL;
404		goto out;
405	}
406
407	if (tx)
408		crypto_info = &ctx->crypto_send;
409	else
410		crypto_info = &ctx->crypto_recv;
411
412	/* Currently we don't support set crypto info more than one time */
413	if (TLS_CRYPTO_INFO_READY(crypto_info)) {
414		rc = -EBUSY;
415		goto out;
416	}
417
418	rc = copy_from_user(crypto_info, optval, sizeof(*crypto_info));
419	if (rc) {
420		rc = -EFAULT;
421		goto err_crypto_info;
422	}
423
424	/* check version */
425	if (crypto_info->version != TLS_1_2_VERSION) {
426		rc = -ENOTSUPP;
427		goto err_crypto_info;
428	}
429
430	switch (crypto_info->cipher_type) {
431	case TLS_CIPHER_AES_GCM_128: {
432		if (optlen != sizeof(struct tls12_crypto_info_aes_gcm_128)) {
433			rc = -EINVAL;
434			goto err_crypto_info;
435		}
436		rc = copy_from_user(crypto_info + 1, optval + sizeof(*crypto_info),
437				    optlen - sizeof(*crypto_info));
438		if (rc) {
439			rc = -EFAULT;
440			goto err_crypto_info;
441		}
442		break;
443	}
444	default:
445		rc = -EINVAL;
446		goto err_crypto_info;
447	}
448
449	/* currently SW is default, we will have ethtool in future */
450	if (tx) {
451		rc = tls_set_sw_offload(sk, ctx, 1);
452		if (ctx->conf == TLS_SW_RX)
453			conf = TLS_SW_RXTX;
454		else
455			conf = TLS_SW_TX;
456	} else {
457		rc = tls_set_sw_offload(sk, ctx, 0);
458		if (ctx->conf == TLS_SW_TX)
459			conf = TLS_SW_RXTX;
460		else
461			conf = TLS_SW_RX;
462	}
463
464	if (rc)
465		goto err_crypto_info;
466
467	ctx->conf = conf;
468	update_sk_prot(sk, ctx);
469	if (tx) {
470		ctx->sk_write_space = sk->sk_write_space;
471		sk->sk_write_space = tls_write_space;
472	} else {
473		sk->sk_socket->ops = &tls_sw_proto_ops;
474	}
475	goto out;
476
477err_crypto_info:
478	memset(crypto_info, 0, sizeof(*crypto_info));
479out:
480	return rc;
481}
482
483static int do_tls_setsockopt(struct sock *sk, int optname,
484			     char __user *optval, unsigned int optlen)
485{
486	int rc = 0;
487
488	switch (optname) {
489	case TLS_TX:
490	case TLS_RX:
491		lock_sock(sk);
492		rc = do_tls_setsockopt_conf(sk, optval, optlen,
493					    optname == TLS_TX);
494		release_sock(sk);
495		break;
496	default:
497		rc = -ENOPROTOOPT;
498		break;
499	}
500	return rc;
501}
502
503static int tls_setsockopt(struct sock *sk, int level, int optname,
504			  char __user *optval, unsigned int optlen)
505{
506	struct tls_context *ctx = tls_get_ctx(sk);
507
508	if (level != SOL_TLS)
509		return ctx->setsockopt(sk, level, optname, optval, optlen);
510
511	return do_tls_setsockopt(sk, optname, optval, optlen);
512}
513
514static struct tls_context *create_ctx(struct sock *sk)
515{
516	struct inet_connection_sock *icsk = inet_csk(sk);
517	struct tls_context *ctx;
518
519	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
520	if (!ctx)
521		return NULL;
522
523	icsk->icsk_ulp_data = ctx;
524	return ctx;
525}
526
527static int tls_hw_prot(struct sock *sk)
528{
529	struct tls_context *ctx;
530	struct tls_device *dev;
531	int rc = 0;
532
533	mutex_lock(&device_mutex);
534	list_for_each_entry(dev, &device_list, dev_list) {
535		if (dev->feature && dev->feature(dev)) {
536			ctx = create_ctx(sk);
537			if (!ctx)
538				goto out;
539
540			ctx->hash = sk->sk_prot->hash;
541			ctx->unhash = sk->sk_prot->unhash;
542			ctx->sk_proto_close = sk->sk_prot->close;
543			ctx->conf = TLS_HW_RECORD;
544			update_sk_prot(sk, ctx);
545			rc = 1;
546			break;
547		}
548	}
549out:
550	mutex_unlock(&device_mutex);
551	return rc;
552}
553
554static void tls_hw_unhash(struct sock *sk)
555{
556	struct tls_context *ctx = tls_get_ctx(sk);
557	struct tls_device *dev;
558
559	mutex_lock(&device_mutex);
560	list_for_each_entry(dev, &device_list, dev_list) {
561		if (dev->unhash)
562			dev->unhash(dev, sk);
563	}
564	mutex_unlock(&device_mutex);
565	ctx->unhash(sk);
566}
567
568static int tls_hw_hash(struct sock *sk)
569{
570	struct tls_context *ctx = tls_get_ctx(sk);
571	struct tls_device *dev;
572	int err;
573
574	err = ctx->hash(sk);
575	mutex_lock(&device_mutex);
576	list_for_each_entry(dev, &device_list, dev_list) {
577		if (dev->hash)
578			err |= dev->hash(dev, sk);
579	}
580	mutex_unlock(&device_mutex);
581
582	if (err)
583		tls_hw_unhash(sk);
584	return err;
585}
586
587static void build_protos(struct proto *prot, struct proto *base)
588{
589	prot[TLS_BASE] = *base;
590	prot[TLS_BASE].setsockopt	= tls_setsockopt;
591	prot[TLS_BASE].getsockopt	= tls_getsockopt;
592	prot[TLS_BASE].close		= tls_sk_proto_close;
593
594	prot[TLS_SW_TX] = prot[TLS_BASE];
595	prot[TLS_SW_TX].sendmsg		= tls_sw_sendmsg;
596	prot[TLS_SW_TX].sendpage	= tls_sw_sendpage;
597
598	prot[TLS_SW_RX] = prot[TLS_BASE];
599	prot[TLS_SW_RX].recvmsg		= tls_sw_recvmsg;
600	prot[TLS_SW_RX].close		= tls_sk_proto_close;
601
602	prot[TLS_SW_RXTX] = prot[TLS_SW_TX];
603	prot[TLS_SW_RXTX].recvmsg	= tls_sw_recvmsg;
604	prot[TLS_SW_RXTX].close		= tls_sk_proto_close;
605
606	prot[TLS_HW_RECORD] = *base;
607	prot[TLS_HW_RECORD].hash	= tls_hw_hash;
608	prot[TLS_HW_RECORD].unhash	= tls_hw_unhash;
609	prot[TLS_HW_RECORD].close	= tls_sk_proto_close;
610}
611
612static int tls_init(struct sock *sk)
613{
614	int ip_ver = sk->sk_family == AF_INET6 ? TLSV6 : TLSV4;
615	struct tls_context *ctx;
616	int rc = 0;
617
618	if (tls_hw_prot(sk))
619		goto out;
620
621	/* The TLS ulp is currently supported only for TCP sockets
622	 * in ESTABLISHED state.
623	 * Supporting sockets in LISTEN state will require us
624	 * to modify the accept implementation to clone rather then
625	 * share the ulp context.
626	 */
627	if (sk->sk_state != TCP_ESTABLISHED)
628		return -ENOTSUPP;
629
630	/* allocate tls context */
631	ctx = create_ctx(sk);
632	if (!ctx) {
633		rc = -ENOMEM;
634		goto out;
635	}
636	ctx->setsockopt = sk->sk_prot->setsockopt;
637	ctx->getsockopt = sk->sk_prot->getsockopt;
638	ctx->sk_proto_close = sk->sk_prot->close;
639
640	/* Build IPv6 TLS whenever the address of tcpv6_prot changes */
641	if (ip_ver == TLSV6 &&
642	    unlikely(sk->sk_prot != smp_load_acquire(&saved_tcpv6_prot))) {
643		mutex_lock(&tcpv6_prot_mutex);
644		if (likely(sk->sk_prot != saved_tcpv6_prot)) {
645			build_protos(tls_prots[TLSV6], sk->sk_prot);
646			smp_store_release(&saved_tcpv6_prot, sk->sk_prot);
647		}
648		mutex_unlock(&tcpv6_prot_mutex);
649	}
650
651	ctx->conf = TLS_BASE;
652	update_sk_prot(sk, ctx);
653out:
654	return rc;
655}
656
657void tls_register_device(struct tls_device *device)
658{
659	mutex_lock(&device_mutex);
660	list_add_tail(&device->dev_list, &device_list);
661	mutex_unlock(&device_mutex);
662}
663EXPORT_SYMBOL(tls_register_device);
664
665void tls_unregister_device(struct tls_device *device)
666{
667	mutex_lock(&device_mutex);
668	list_del(&device->dev_list);
669	mutex_unlock(&device_mutex);
670}
671EXPORT_SYMBOL(tls_unregister_device);
672
673static struct tcp_ulp_ops tcp_tls_ulp_ops __read_mostly = {
674	.name			= "tls",
675	.uid			= TCP_ULP_TLS,
676	.user_visible		= true,
677	.owner			= THIS_MODULE,
678	.init			= tls_init,
679};
680
681static int __init tls_register(void)
682{
683	build_protos(tls_prots[TLSV4], &tcp_prot);
684
685	tls_sw_proto_ops = inet_stream_ops;
686	tls_sw_proto_ops.poll = tls_sw_poll;
687	tls_sw_proto_ops.splice_read = tls_sw_splice_read;
688
689	tcp_register_ulp(&tcp_tls_ulp_ops);
690
691	return 0;
692}
693
694static void __exit tls_unregister(void)
695{
696	tcp_unregister_ulp(&tcp_tls_ulp_ops);
697}
698
699module_init(tls_register);
700module_exit(tls_unregister);