xref: /linux/net/tls/tls_sw.c (revision 6439a0e64c355d2e375bd094f365d56ce81faba3)
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  * Copyright (c) 2016-2017, Lance Chao <lancerchao@fb.com>. All rights reserved.
5  * Copyright (c) 2016, Fridolin Pokorny <fridolin.pokorny@gmail.com>. All rights reserved.
6  * Copyright (c) 2016, Nikos Mavrogiannopoulos <nmav@gnutls.org>. All rights reserved.
7  * Copyright (c) 2018, Covalent IO, Inc. http://covalent.io
8  *
9  * This software is available to you under a choice of one of two
10  * licenses.  You may choose to be licensed under the terms of the GNU
11  * General Public License (GPL) Version 2, available from the file
12  * COPYING in the main directory of this source tree, or the
13  * OpenIB.org BSD license below:
14  *
15  *     Redistribution and use in source and binary forms, with or
16  *     without modification, are permitted provided that the following
17  *     conditions are met:
18  *
19  *      - Redistributions of source code must retain the above
20  *        copyright notice, this list of conditions and the following
21  *        disclaimer.
22  *
23  *      - Redistributions in binary form must reproduce the above
24  *        copyright notice, this list of conditions and the following
25  *        disclaimer in the documentation and/or other materials
26  *        provided with the distribution.
27  *
28  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
29  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
30  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
31  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
32  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
33  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
34  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
35  * SOFTWARE.
36  */
37 
38 #include <linux/bug.h>
39 #include <linux/sched/signal.h>
40 #include <linux/module.h>
41 #include <linux/kernel.h>
42 #include <linux/splice.h>
43 #include <crypto/aead.h>
44 
45 #include <net/strparser.h>
46 #include <net/tls.h>
47 #include <trace/events/sock.h>
48 
49 #include "tls.h"
50 
51 struct tls_decrypt_arg {
52 	struct_group(inargs,
53 	bool zc;
54 	bool async;
55 	bool async_done;
56 	u8 tail;
57 	);
58 
59 	struct sk_buff *skb;
60 };
61 
62 struct tls_decrypt_ctx {
63 	struct sock *sk;
64 	u8 iv[TLS_MAX_IV_SIZE];
65 	u8 aad[TLS_MAX_AAD_SIZE];
66 	u8 tail;
67 	bool free_sgout;
68 	struct scatterlist sg[];
69 };
70 
tls_err_abort(struct sock * sk,int err)71 noinline void tls_err_abort(struct sock *sk, int err)
72 {
73 	WARN_ON_ONCE(err >= 0);
74 	/* sk->sk_err should contain a positive error code. */
75 	WRITE_ONCE(sk->sk_err, -err);
76 	/* Paired with smp_rmb() in tcp_poll() */
77 	smp_wmb();
78 	sk_error_report(sk);
79 }
80 
__skb_nsg(struct sk_buff * skb,int offset,int len,unsigned int recursion_level)81 static int __skb_nsg(struct sk_buff *skb, int offset, int len,
82                      unsigned int recursion_level)
83 {
84         int start = skb_headlen(skb);
85         int i, chunk = start - offset;
86         struct sk_buff *frag_iter;
87         int elt = 0;
88 
89         if (unlikely(recursion_level >= 24))
90                 return -EMSGSIZE;
91 
92         if (chunk > 0) {
93                 if (chunk > len)
94                         chunk = len;
95                 elt++;
96                 len -= chunk;
97                 if (len == 0)
98                         return elt;
99                 offset += chunk;
100         }
101 
102         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
103                 int end;
104 
105                 WARN_ON(start > offset + len);
106 
107                 end = start + skb_frag_size(&skb_shinfo(skb)->frags[i]);
108                 chunk = end - offset;
109                 if (chunk > 0) {
110                         if (chunk > len)
111                                 chunk = len;
112                         elt++;
113                         len -= chunk;
114                         if (len == 0)
115                                 return elt;
116                         offset += chunk;
117                 }
118                 start = end;
119         }
120 
121         if (unlikely(skb_has_frag_list(skb))) {
122                 skb_walk_frags(skb, frag_iter) {
123                         int end, ret;
124 
125                         WARN_ON(start > offset + len);
126 
127                         end = start + frag_iter->len;
128                         chunk = end - offset;
129                         if (chunk > 0) {
130                                 if (chunk > len)
131                                         chunk = len;
132                                 ret = __skb_nsg(frag_iter, offset - start, chunk,
133                                                 recursion_level + 1);
134                                 if (unlikely(ret < 0))
135                                         return ret;
136                                 elt += ret;
137                                 len -= chunk;
138                                 if (len == 0)
139                                         return elt;
140                                 offset += chunk;
141                         }
142                         start = end;
143                 }
144         }
145         BUG_ON(len);
146         return elt;
147 }
148 
149 /* Return the number of scatterlist elements required to completely map the
150  * skb, or -EMSGSIZE if the recursion depth is exceeded.
151  */
skb_nsg(struct sk_buff * skb,int offset,int len)152 static int skb_nsg(struct sk_buff *skb, int offset, int len)
153 {
154         return __skb_nsg(skb, offset, len, 0);
155 }
156 
tls_padding_length(struct tls_prot_info * prot,struct sk_buff * skb,struct tls_decrypt_arg * darg)157 static int tls_padding_length(struct tls_prot_info *prot, struct sk_buff *skb,
158 			      struct tls_decrypt_arg *darg)
159 {
160 	struct strp_msg *rxm = strp_msg(skb);
161 	struct tls_msg *tlm = tls_msg(skb);
162 	int sub = 0;
163 
164 	/* Determine zero-padding length */
165 	if (prot->version == TLS_1_3_VERSION) {
166 		int offset = rxm->full_len - TLS_TAG_SIZE - 1;
167 		char content_type = darg->zc ? darg->tail : 0;
168 		int err;
169 
170 		while (content_type == 0) {
171 			if (offset < prot->prepend_size)
172 				return -EBADMSG;
173 			err = skb_copy_bits(skb, rxm->offset + offset,
174 					    &content_type, 1);
175 			if (err)
176 				return err;
177 			if (content_type)
178 				break;
179 			sub++;
180 			offset--;
181 		}
182 		tlm->control = content_type;
183 	}
184 	return sub;
185 }
186 
tls_decrypt_done(void * data,int err)187 static void tls_decrypt_done(void *data, int err)
188 {
189 	struct aead_request *aead_req = data;
190 	struct crypto_aead *aead = crypto_aead_reqtfm(aead_req);
191 	struct scatterlist *sgout = aead_req->dst;
192 	struct tls_sw_context_rx *ctx;
193 	struct tls_decrypt_ctx *dctx;
194 	struct tls_context *tls_ctx;
195 	struct scatterlist *sg;
196 	unsigned int pages;
197 	struct sock *sk;
198 	int aead_size;
199 
200 	/* If requests get too backlogged crypto API returns -EBUSY and calls
201 	 * ->complete(-EINPROGRESS) immediately followed by ->complete(0)
202 	 * to make waiting for backlog to flush with crypto_wait_req() easier.
203 	 * First wait converts -EBUSY -> -EINPROGRESS, and the second one
204 	 * -EINPROGRESS -> 0.
205 	 * We have a single struct crypto_async_request per direction, this
206 	 * scheme doesn't help us, so just ignore the first ->complete().
207 	 */
208 	if (err == -EINPROGRESS)
209 		return;
210 
211 	aead_size = sizeof(*aead_req) + crypto_aead_reqsize(aead);
212 	aead_size = ALIGN(aead_size, __alignof__(*dctx));
213 	dctx = (void *)((u8 *)aead_req + aead_size);
214 
215 	sk = dctx->sk;
216 	tls_ctx = tls_get_ctx(sk);
217 	ctx = tls_sw_ctx_rx(tls_ctx);
218 
219 	/* Propagate if there was an err */
220 	if (err) {
221 		if (err == -EBADMSG)
222 			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSDECRYPTERROR);
223 		ctx->async_wait.err = err;
224 		tls_err_abort(sk, err);
225 	}
226 
227 	/* Free the destination pages if skb was not decrypted inplace */
228 	if (dctx->free_sgout) {
229 		/* Skip the first S/G entry as it points to AAD */
230 		for_each_sg(sg_next(sgout), sg, UINT_MAX, pages) {
231 			if (!sg)
232 				break;
233 			put_page(sg_page(sg));
234 		}
235 	}
236 
237 	kfree(aead_req);
238 
239 	if (atomic_dec_and_test(&ctx->decrypt_pending))
240 		complete(&ctx->async_wait.completion);
241 }
242 
tls_decrypt_async_wait(struct tls_sw_context_rx * ctx)243 static int tls_decrypt_async_wait(struct tls_sw_context_rx *ctx)
244 {
245 	if (!atomic_dec_and_test(&ctx->decrypt_pending))
246 		crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
247 	atomic_inc(&ctx->decrypt_pending);
248 
249 	return ctx->async_wait.err;
250 }
251 
tls_do_decryption(struct sock * sk,struct scatterlist * sgin,struct scatterlist * sgout,char * iv_recv,size_t data_len,struct aead_request * aead_req,struct tls_decrypt_arg * darg)252 static int tls_do_decryption(struct sock *sk,
253 			     struct scatterlist *sgin,
254 			     struct scatterlist *sgout,
255 			     char *iv_recv,
256 			     size_t data_len,
257 			     struct aead_request *aead_req,
258 			     struct tls_decrypt_arg *darg)
259 {
260 	struct tls_context *tls_ctx = tls_get_ctx(sk);
261 	struct tls_prot_info *prot = &tls_ctx->prot_info;
262 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
263 	int ret;
264 
265 	aead_request_set_tfm(aead_req, ctx->aead_recv);
266 	aead_request_set_ad(aead_req, prot->aad_size);
267 	aead_request_set_crypt(aead_req, sgin, sgout,
268 			       data_len + prot->tag_size,
269 			       (u8 *)iv_recv);
270 
271 	if (darg->async) {
272 		aead_request_set_callback(aead_req,
273 					  CRYPTO_TFM_REQ_MAY_BACKLOG,
274 					  tls_decrypt_done, aead_req);
275 		DEBUG_NET_WARN_ON_ONCE(atomic_read(&ctx->decrypt_pending) < 1);
276 		atomic_inc(&ctx->decrypt_pending);
277 	} else {
278 		DECLARE_CRYPTO_WAIT(wait);
279 
280 		aead_request_set_callback(aead_req,
281 					  CRYPTO_TFM_REQ_MAY_BACKLOG,
282 					  crypto_req_done, &wait);
283 		ret = crypto_aead_decrypt(aead_req);
284 		if (ret == -EINPROGRESS || ret == -EBUSY)
285 			ret = crypto_wait_req(ret, &wait);
286 		return ret;
287 	}
288 
289 	ret = crypto_aead_decrypt(aead_req);
290 	if (ret == -EINPROGRESS)
291 		return 0;
292 
293 	if (ret == -EBUSY) {
294 		ret = tls_decrypt_async_wait(ctx);
295 		darg->async_done = true;
296 		/* all completions have run, we're not doing async anymore */
297 		darg->async = false;
298 		return ret;
299 	}
300 
301 	atomic_dec(&ctx->decrypt_pending);
302 	darg->async = false;
303 
304 	return ret;
305 }
306 
tls_trim_both_msgs(struct sock * sk,int target_size)307 static void tls_trim_both_msgs(struct sock *sk, int target_size)
308 {
309 	struct tls_context *tls_ctx = tls_get_ctx(sk);
310 	struct tls_prot_info *prot = &tls_ctx->prot_info;
311 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
312 	struct tls_rec *rec = ctx->open_rec;
313 
314 	sk_msg_trim(sk, &rec->msg_plaintext, target_size);
315 	if (target_size > 0)
316 		target_size += prot->overhead_size;
317 	sk_msg_trim(sk, &rec->msg_encrypted, target_size);
318 }
319 
tls_alloc_encrypted_msg(struct sock * sk,int len)320 static int tls_alloc_encrypted_msg(struct sock *sk, int len)
321 {
322 	struct tls_context *tls_ctx = tls_get_ctx(sk);
323 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
324 	struct tls_rec *rec = ctx->open_rec;
325 	struct sk_msg *msg_en = &rec->msg_encrypted;
326 
327 	return sk_msg_alloc(sk, msg_en, len, 0);
328 }
329 
tls_clone_plaintext_msg(struct sock * sk,int required)330 static int tls_clone_plaintext_msg(struct sock *sk, int required)
331 {
332 	struct tls_context *tls_ctx = tls_get_ctx(sk);
333 	struct tls_prot_info *prot = &tls_ctx->prot_info;
334 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
335 	struct tls_rec *rec = ctx->open_rec;
336 	struct sk_msg *msg_pl = &rec->msg_plaintext;
337 	struct sk_msg *msg_en = &rec->msg_encrypted;
338 	int skip, len;
339 
340 	/* We add page references worth len bytes from encrypted sg
341 	 * at the end of plaintext sg. It is guaranteed that msg_en
342 	 * has enough required room (ensured by caller).
343 	 */
344 	len = required - msg_pl->sg.size;
345 
346 	/* Skip initial bytes in msg_en's data to be able to use
347 	 * same offset of both plain and encrypted data.
348 	 */
349 	skip = prot->prepend_size + msg_pl->sg.size;
350 
351 	return sk_msg_clone(sk, msg_pl, msg_en, skip, len);
352 }
353 
tls_get_rec(struct sock * sk)354 static struct tls_rec *tls_get_rec(struct sock *sk)
355 {
356 	struct tls_context *tls_ctx = tls_get_ctx(sk);
357 	struct tls_prot_info *prot = &tls_ctx->prot_info;
358 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
359 	struct sk_msg *msg_pl, *msg_en;
360 	struct tls_rec *rec;
361 	int mem_size;
362 
363 	mem_size = sizeof(struct tls_rec) + crypto_aead_reqsize(ctx->aead_send);
364 
365 	rec = kzalloc(mem_size, sk->sk_allocation);
366 	if (!rec)
367 		return NULL;
368 
369 	msg_pl = &rec->msg_plaintext;
370 	msg_en = &rec->msg_encrypted;
371 
372 	sk_msg_init(msg_pl);
373 	sk_msg_init(msg_en);
374 
375 	sg_init_table(rec->sg_aead_in, 2);
376 	sg_set_buf(&rec->sg_aead_in[0], rec->aad_space, prot->aad_size);
377 	sg_unmark_end(&rec->sg_aead_in[1]);
378 
379 	sg_init_table(rec->sg_aead_out, 2);
380 	sg_set_buf(&rec->sg_aead_out[0], rec->aad_space, prot->aad_size);
381 	sg_unmark_end(&rec->sg_aead_out[1]);
382 
383 	rec->sk = sk;
384 
385 	return rec;
386 }
387 
tls_free_rec(struct sock * sk,struct tls_rec * rec)388 static void tls_free_rec(struct sock *sk, struct tls_rec *rec)
389 {
390 	sk_msg_free(sk, &rec->msg_encrypted);
391 	sk_msg_free(sk, &rec->msg_plaintext);
392 	kfree(rec);
393 }
394 
tls_free_open_rec(struct sock * sk)395 static void tls_free_open_rec(struct sock *sk)
396 {
397 	struct tls_context *tls_ctx = tls_get_ctx(sk);
398 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
399 	struct tls_rec *rec = ctx->open_rec;
400 
401 	if (rec) {
402 		tls_free_rec(sk, rec);
403 		ctx->open_rec = NULL;
404 	}
405 }
406 
tls_tx_records(struct sock * sk,int flags)407 int tls_tx_records(struct sock *sk, int flags)
408 {
409 	struct tls_context *tls_ctx = tls_get_ctx(sk);
410 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
411 	struct tls_rec *rec, *tmp;
412 	struct sk_msg *msg_en;
413 	int tx_flags, rc = 0;
414 
415 	if (tls_is_partially_sent_record(tls_ctx)) {
416 		rec = list_first_entry(&ctx->tx_list,
417 				       struct tls_rec, list);
418 
419 		if (flags == -1)
420 			tx_flags = rec->tx_flags;
421 		else
422 			tx_flags = flags;
423 
424 		rc = tls_push_partial_record(sk, tls_ctx, tx_flags);
425 		if (rc)
426 			goto tx_err;
427 
428 		/* Full record has been transmitted.
429 		 * Remove the head of tx_list
430 		 */
431 		list_del(&rec->list);
432 		sk_msg_free(sk, &rec->msg_plaintext);
433 		kfree(rec);
434 	}
435 
436 	/* Tx all ready records */
437 	list_for_each_entry_safe(rec, tmp, &ctx->tx_list, list) {
438 		if (READ_ONCE(rec->tx_ready)) {
439 			if (flags == -1)
440 				tx_flags = rec->tx_flags;
441 			else
442 				tx_flags = flags;
443 
444 			msg_en = &rec->msg_encrypted;
445 			rc = tls_push_sg(sk, tls_ctx,
446 					 &msg_en->sg.data[msg_en->sg.curr],
447 					 0, tx_flags);
448 			if (rc)
449 				goto tx_err;
450 
451 			list_del(&rec->list);
452 			sk_msg_free(sk, &rec->msg_plaintext);
453 			kfree(rec);
454 		} else {
455 			break;
456 		}
457 	}
458 
459 tx_err:
460 	if (rc < 0 && rc != -EAGAIN)
461 		tls_err_abort(sk, rc);
462 
463 	return rc;
464 }
465 
tls_encrypt_done(void * data,int err)466 static void tls_encrypt_done(void *data, int err)
467 {
468 	struct tls_sw_context_tx *ctx;
469 	struct tls_context *tls_ctx;
470 	struct tls_prot_info *prot;
471 	struct tls_rec *rec = data;
472 	struct scatterlist *sge;
473 	struct sk_msg *msg_en;
474 	struct sock *sk;
475 
476 	if (err == -EINPROGRESS) /* see the comment in tls_decrypt_done() */
477 		return;
478 
479 	msg_en = &rec->msg_encrypted;
480 
481 	sk = rec->sk;
482 	tls_ctx = tls_get_ctx(sk);
483 	prot = &tls_ctx->prot_info;
484 	ctx = tls_sw_ctx_tx(tls_ctx);
485 
486 	sge = sk_msg_elem(msg_en, msg_en->sg.curr);
487 	sge->offset -= prot->prepend_size;
488 	sge->length += prot->prepend_size;
489 
490 	/* Check if error is previously set on socket */
491 	if (err || sk->sk_err) {
492 		rec = NULL;
493 
494 		/* If err is already set on socket, return the same code */
495 		if (sk->sk_err) {
496 			ctx->async_wait.err = -sk->sk_err;
497 		} else {
498 			ctx->async_wait.err = err;
499 			tls_err_abort(sk, err);
500 		}
501 	}
502 
503 	if (rec) {
504 		struct tls_rec *first_rec;
505 
506 		/* Mark the record as ready for transmission */
507 		smp_store_mb(rec->tx_ready, true);
508 
509 		/* If received record is at head of tx_list, schedule tx */
510 		first_rec = list_first_entry(&ctx->tx_list,
511 					     struct tls_rec, list);
512 		if (rec == first_rec) {
513 			/* Schedule the transmission */
514 			if (!test_and_set_bit(BIT_TX_SCHEDULED,
515 					      &ctx->tx_bitmask))
516 				schedule_delayed_work(&ctx->tx_work.work, 1);
517 		}
518 	}
519 
520 	if (atomic_dec_and_test(&ctx->encrypt_pending))
521 		complete(&ctx->async_wait.completion);
522 }
523 
tls_encrypt_async_wait(struct tls_sw_context_tx * ctx)524 static int tls_encrypt_async_wait(struct tls_sw_context_tx *ctx)
525 {
526 	if (!atomic_dec_and_test(&ctx->encrypt_pending))
527 		crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
528 	atomic_inc(&ctx->encrypt_pending);
529 
530 	return ctx->async_wait.err;
531 }
532 
tls_do_encryption(struct sock * sk,struct tls_context * tls_ctx,struct tls_sw_context_tx * ctx,struct aead_request * aead_req,size_t data_len,u32 start)533 static int tls_do_encryption(struct sock *sk,
534 			     struct tls_context *tls_ctx,
535 			     struct tls_sw_context_tx *ctx,
536 			     struct aead_request *aead_req,
537 			     size_t data_len, u32 start)
538 {
539 	struct tls_prot_info *prot = &tls_ctx->prot_info;
540 	struct tls_rec *rec = ctx->open_rec;
541 	struct sk_msg *msg_en = &rec->msg_encrypted;
542 	struct scatterlist *sge = sk_msg_elem(msg_en, start);
543 	int rc, iv_offset = 0;
544 
545 	/* For CCM based ciphers, first byte of IV is a constant */
546 	switch (prot->cipher_type) {
547 	case TLS_CIPHER_AES_CCM_128:
548 		rec->iv_data[0] = TLS_AES_CCM_IV_B0_BYTE;
549 		iv_offset = 1;
550 		break;
551 	case TLS_CIPHER_SM4_CCM:
552 		rec->iv_data[0] = TLS_SM4_CCM_IV_B0_BYTE;
553 		iv_offset = 1;
554 		break;
555 	}
556 
557 	memcpy(&rec->iv_data[iv_offset], tls_ctx->tx.iv,
558 	       prot->iv_size + prot->salt_size);
559 
560 	tls_xor_iv_with_seq(prot, rec->iv_data + iv_offset,
561 			    tls_ctx->tx.rec_seq);
562 
563 	sge->offset += prot->prepend_size;
564 	sge->length -= prot->prepend_size;
565 
566 	msg_en->sg.curr = start;
567 
568 	aead_request_set_tfm(aead_req, ctx->aead_send);
569 	aead_request_set_ad(aead_req, prot->aad_size);
570 	aead_request_set_crypt(aead_req, rec->sg_aead_in,
571 			       rec->sg_aead_out,
572 			       data_len, rec->iv_data);
573 
574 	aead_request_set_callback(aead_req, CRYPTO_TFM_REQ_MAY_BACKLOG,
575 				  tls_encrypt_done, rec);
576 
577 	/* Add the record in tx_list */
578 	list_add_tail((struct list_head *)&rec->list, &ctx->tx_list);
579 	DEBUG_NET_WARN_ON_ONCE(atomic_read(&ctx->encrypt_pending) < 1);
580 	atomic_inc(&ctx->encrypt_pending);
581 
582 	rc = crypto_aead_encrypt(aead_req);
583 	if (rc == -EBUSY) {
584 		rc = tls_encrypt_async_wait(ctx);
585 		rc = rc ?: -EINPROGRESS;
586 	}
587 	if (!rc || rc != -EINPROGRESS) {
588 		atomic_dec(&ctx->encrypt_pending);
589 		sge->offset -= prot->prepend_size;
590 		sge->length += prot->prepend_size;
591 	}
592 
593 	if (!rc) {
594 		WRITE_ONCE(rec->tx_ready, true);
595 	} else if (rc != -EINPROGRESS) {
596 		list_del(&rec->list);
597 		return rc;
598 	}
599 
600 	/* Unhook the record from context if encryption is not failure */
601 	ctx->open_rec = NULL;
602 	tls_advance_record_sn(sk, prot, &tls_ctx->tx);
603 	return rc;
604 }
605 
tls_split_open_record(struct sock * sk,struct tls_rec * from,struct tls_rec ** to,struct sk_msg * msg_opl,struct sk_msg * msg_oen,u32 split_point,u32 tx_overhead_size,u32 * orig_end)606 static int tls_split_open_record(struct sock *sk, struct tls_rec *from,
607 				 struct tls_rec **to, struct sk_msg *msg_opl,
608 				 struct sk_msg *msg_oen, u32 split_point,
609 				 u32 tx_overhead_size, u32 *orig_end)
610 {
611 	u32 i, j, bytes = 0, apply = msg_opl->apply_bytes;
612 	struct scatterlist *sge, *osge, *nsge;
613 	u32 orig_size = msg_opl->sg.size;
614 	struct scatterlist tmp = { };
615 	struct sk_msg *msg_npl;
616 	struct tls_rec *new;
617 	int ret;
618 
619 	new = tls_get_rec(sk);
620 	if (!new)
621 		return -ENOMEM;
622 	ret = sk_msg_alloc(sk, &new->msg_encrypted, msg_opl->sg.size +
623 			   tx_overhead_size, 0);
624 	if (ret < 0) {
625 		tls_free_rec(sk, new);
626 		return ret;
627 	}
628 
629 	*orig_end = msg_opl->sg.end;
630 	i = msg_opl->sg.start;
631 	sge = sk_msg_elem(msg_opl, i);
632 	while (apply && sge->length) {
633 		if (sge->length > apply) {
634 			u32 len = sge->length - apply;
635 
636 			get_page(sg_page(sge));
637 			sg_set_page(&tmp, sg_page(sge), len,
638 				    sge->offset + apply);
639 			sge->length = apply;
640 			bytes += apply;
641 			apply = 0;
642 		} else {
643 			apply -= sge->length;
644 			bytes += sge->length;
645 		}
646 
647 		sk_msg_iter_var_next(i);
648 		if (i == msg_opl->sg.end)
649 			break;
650 		sge = sk_msg_elem(msg_opl, i);
651 	}
652 
653 	msg_opl->sg.end = i;
654 	msg_opl->sg.curr = i;
655 	msg_opl->sg.copybreak = 0;
656 	msg_opl->apply_bytes = 0;
657 	msg_opl->sg.size = bytes;
658 
659 	msg_npl = &new->msg_plaintext;
660 	msg_npl->apply_bytes = apply;
661 	msg_npl->sg.size = orig_size - bytes;
662 
663 	j = msg_npl->sg.start;
664 	nsge = sk_msg_elem(msg_npl, j);
665 	if (tmp.length) {
666 		memcpy(nsge, &tmp, sizeof(*nsge));
667 		sk_msg_iter_var_next(j);
668 		nsge = sk_msg_elem(msg_npl, j);
669 	}
670 
671 	osge = sk_msg_elem(msg_opl, i);
672 	while (osge->length) {
673 		memcpy(nsge, osge, sizeof(*nsge));
674 		sg_unmark_end(nsge);
675 		sk_msg_iter_var_next(i);
676 		sk_msg_iter_var_next(j);
677 		if (i == *orig_end)
678 			break;
679 		osge = sk_msg_elem(msg_opl, i);
680 		nsge = sk_msg_elem(msg_npl, j);
681 	}
682 
683 	msg_npl->sg.end = j;
684 	msg_npl->sg.curr = j;
685 	msg_npl->sg.copybreak = 0;
686 
687 	*to = new;
688 	return 0;
689 }
690 
tls_merge_open_record(struct sock * sk,struct tls_rec * to,struct tls_rec * from,u32 orig_end)691 static void tls_merge_open_record(struct sock *sk, struct tls_rec *to,
692 				  struct tls_rec *from, u32 orig_end)
693 {
694 	struct sk_msg *msg_npl = &from->msg_plaintext;
695 	struct sk_msg *msg_opl = &to->msg_plaintext;
696 	struct scatterlist *osge, *nsge;
697 	u32 i, j;
698 
699 	i = msg_opl->sg.end;
700 	sk_msg_iter_var_prev(i);
701 	j = msg_npl->sg.start;
702 
703 	osge = sk_msg_elem(msg_opl, i);
704 	nsge = sk_msg_elem(msg_npl, j);
705 
706 	if (sg_page(osge) == sg_page(nsge) &&
707 	    osge->offset + osge->length == nsge->offset) {
708 		osge->length += nsge->length;
709 		put_page(sg_page(nsge));
710 	}
711 
712 	msg_opl->sg.end = orig_end;
713 	msg_opl->sg.curr = orig_end;
714 	msg_opl->sg.copybreak = 0;
715 	msg_opl->apply_bytes = msg_opl->sg.size + msg_npl->sg.size;
716 	msg_opl->sg.size += msg_npl->sg.size;
717 
718 	sk_msg_free(sk, &to->msg_encrypted);
719 	sk_msg_xfer_full(&to->msg_encrypted, &from->msg_encrypted);
720 
721 	kfree(from);
722 }
723 
tls_push_record(struct sock * sk,int flags,unsigned char record_type)724 static int tls_push_record(struct sock *sk, int flags,
725 			   unsigned char record_type)
726 {
727 	struct tls_context *tls_ctx = tls_get_ctx(sk);
728 	struct tls_prot_info *prot = &tls_ctx->prot_info;
729 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
730 	struct tls_rec *rec = ctx->open_rec, *tmp = NULL;
731 	u32 i, split_point, orig_end;
732 	struct sk_msg *msg_pl, *msg_en;
733 	struct aead_request *req;
734 	bool split;
735 	int rc;
736 
737 	if (!rec)
738 		return 0;
739 
740 	msg_pl = &rec->msg_plaintext;
741 	msg_en = &rec->msg_encrypted;
742 
743 	split_point = msg_pl->apply_bytes;
744 	split = split_point && split_point < msg_pl->sg.size;
745 	if (unlikely((!split &&
746 		      msg_pl->sg.size +
747 		      prot->overhead_size > msg_en->sg.size) ||
748 		     (split &&
749 		      split_point +
750 		      prot->overhead_size > msg_en->sg.size))) {
751 		split = true;
752 		split_point = msg_en->sg.size;
753 	}
754 	if (split) {
755 		rc = tls_split_open_record(sk, rec, &tmp, msg_pl, msg_en,
756 					   split_point, prot->overhead_size,
757 					   &orig_end);
758 		if (rc < 0)
759 			return rc;
760 		/* This can happen if above tls_split_open_record allocates
761 		 * a single large encryption buffer instead of two smaller
762 		 * ones. In this case adjust pointers and continue without
763 		 * split.
764 		 */
765 		if (!msg_pl->sg.size) {
766 			tls_merge_open_record(sk, rec, tmp, orig_end);
767 			msg_pl = &rec->msg_plaintext;
768 			msg_en = &rec->msg_encrypted;
769 			split = false;
770 		}
771 		sk_msg_trim(sk, msg_en, msg_pl->sg.size +
772 			    prot->overhead_size);
773 	}
774 
775 	rec->tx_flags = flags;
776 	req = &rec->aead_req;
777 
778 	i = msg_pl->sg.end;
779 	sk_msg_iter_var_prev(i);
780 
781 	rec->content_type = record_type;
782 	if (prot->version == TLS_1_3_VERSION) {
783 		/* Add content type to end of message.  No padding added */
784 		sg_set_buf(&rec->sg_content_type, &rec->content_type, 1);
785 		sg_mark_end(&rec->sg_content_type);
786 		sg_chain(msg_pl->sg.data, msg_pl->sg.end + 1,
787 			 &rec->sg_content_type);
788 	} else {
789 		sg_mark_end(sk_msg_elem(msg_pl, i));
790 	}
791 
792 	if (msg_pl->sg.end < msg_pl->sg.start) {
793 		sg_chain(&msg_pl->sg.data[msg_pl->sg.start],
794 			 MAX_SKB_FRAGS - msg_pl->sg.start + 1,
795 			 msg_pl->sg.data);
796 	}
797 
798 	i = msg_pl->sg.start;
799 	sg_chain(rec->sg_aead_in, 2, &msg_pl->sg.data[i]);
800 
801 	i = msg_en->sg.end;
802 	sk_msg_iter_var_prev(i);
803 	sg_mark_end(sk_msg_elem(msg_en, i));
804 
805 	i = msg_en->sg.start;
806 	sg_chain(rec->sg_aead_out, 2, &msg_en->sg.data[i]);
807 
808 	tls_make_aad(rec->aad_space, msg_pl->sg.size + prot->tail_size,
809 		     tls_ctx->tx.rec_seq, record_type, prot);
810 
811 	tls_fill_prepend(tls_ctx,
812 			 page_address(sg_page(&msg_en->sg.data[i])) +
813 			 msg_en->sg.data[i].offset,
814 			 msg_pl->sg.size + prot->tail_size,
815 			 record_type);
816 
817 	tls_ctx->pending_open_record_frags = false;
818 
819 	rc = tls_do_encryption(sk, tls_ctx, ctx, req,
820 			       msg_pl->sg.size + prot->tail_size, i);
821 	if (rc < 0) {
822 		if (rc != -EINPROGRESS) {
823 			tls_err_abort(sk, -EBADMSG);
824 			if (split) {
825 				tls_ctx->pending_open_record_frags = true;
826 				tls_merge_open_record(sk, rec, tmp, orig_end);
827 			}
828 		}
829 		ctx->async_capable = 1;
830 		return rc;
831 	} else if (split) {
832 		msg_pl = &tmp->msg_plaintext;
833 		msg_en = &tmp->msg_encrypted;
834 		sk_msg_trim(sk, msg_en, msg_pl->sg.size + prot->overhead_size);
835 		tls_ctx->pending_open_record_frags = true;
836 		ctx->open_rec = tmp;
837 	}
838 
839 	return tls_tx_records(sk, flags);
840 }
841 
bpf_exec_tx_verdict(struct sk_msg * msg,struct sock * sk,bool full_record,u8 record_type,ssize_t * copied,int flags)842 static int bpf_exec_tx_verdict(struct sk_msg *msg, struct sock *sk,
843 			       bool full_record, u8 record_type,
844 			       ssize_t *copied, int flags)
845 {
846 	struct tls_context *tls_ctx = tls_get_ctx(sk);
847 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
848 	struct sk_msg msg_redir = { };
849 	struct sk_psock *psock;
850 	struct sock *sk_redir;
851 	struct tls_rec *rec;
852 	bool enospc, policy, redir_ingress;
853 	int err = 0, send;
854 	u32 delta = 0;
855 
856 	policy = !(flags & MSG_SENDPAGE_NOPOLICY);
857 	psock = sk_psock_get(sk);
858 	if (!psock || !policy) {
859 		err = tls_push_record(sk, flags, record_type);
860 		if (err && err != -EINPROGRESS && sk->sk_err == EBADMSG) {
861 			*copied -= sk_msg_free(sk, msg);
862 			tls_free_open_rec(sk);
863 			err = -sk->sk_err;
864 		}
865 		if (psock)
866 			sk_psock_put(sk, psock);
867 		return err;
868 	}
869 more_data:
870 	enospc = sk_msg_full(msg);
871 	if (psock->eval == __SK_NONE) {
872 		delta = msg->sg.size;
873 		psock->eval = sk_psock_msg_verdict(sk, psock, msg);
874 		delta -= msg->sg.size;
875 
876 		if ((s32)delta > 0) {
877 			/* It indicates that we executed bpf_msg_pop_data(),
878 			 * causing the plaintext data size to decrease.
879 			 * Therefore the encrypted data size also needs to
880 			 * correspondingly decrease. We only need to subtract
881 			 * delta to calculate the new ciphertext length since
882 			 * ktls does not support block encryption.
883 			 */
884 			struct sk_msg *enc = &ctx->open_rec->msg_encrypted;
885 
886 			sk_msg_trim(sk, enc, enc->sg.size - delta);
887 		}
888 	}
889 	if (msg->cork_bytes && msg->cork_bytes > msg->sg.size &&
890 	    !enospc && !full_record) {
891 		err = -ENOSPC;
892 		goto out_err;
893 	}
894 	msg->cork_bytes = 0;
895 	send = msg->sg.size;
896 	if (msg->apply_bytes && msg->apply_bytes < send)
897 		send = msg->apply_bytes;
898 
899 	switch (psock->eval) {
900 	case __SK_PASS:
901 		err = tls_push_record(sk, flags, record_type);
902 		if (err && err != -EINPROGRESS && sk->sk_err == EBADMSG) {
903 			*copied -= sk_msg_free(sk, msg);
904 			tls_free_open_rec(sk);
905 			err = -sk->sk_err;
906 			goto out_err;
907 		}
908 		break;
909 	case __SK_REDIRECT:
910 		redir_ingress = psock->redir_ingress;
911 		sk_redir = psock->sk_redir;
912 		memcpy(&msg_redir, msg, sizeof(*msg));
913 		if (msg->apply_bytes < send)
914 			msg->apply_bytes = 0;
915 		else
916 			msg->apply_bytes -= send;
917 		sk_msg_return_zero(sk, msg, send);
918 		msg->sg.size -= send;
919 		release_sock(sk);
920 		err = tcp_bpf_sendmsg_redir(sk_redir, redir_ingress,
921 					    &msg_redir, send, flags);
922 		lock_sock(sk);
923 		if (err < 0) {
924 			/* Regardless of whether the data represented by
925 			 * msg_redir is sent successfully, we have already
926 			 * uncharged it via sk_msg_return_zero(). The
927 			 * msg->sg.size represents the remaining unprocessed
928 			 * data, which needs to be uncharged here.
929 			 */
930 			sk_mem_uncharge(sk, msg->sg.size);
931 			*copied -= sk_msg_free_nocharge(sk, &msg_redir);
932 			msg->sg.size = 0;
933 		}
934 		if (msg->sg.size == 0)
935 			tls_free_open_rec(sk);
936 		break;
937 	case __SK_DROP:
938 	default:
939 		sk_msg_free_partial(sk, msg, send);
940 		if (msg->apply_bytes < send)
941 			msg->apply_bytes = 0;
942 		else
943 			msg->apply_bytes -= send;
944 		if (msg->sg.size == 0)
945 			tls_free_open_rec(sk);
946 		*copied -= (send + delta);
947 		err = -EACCES;
948 	}
949 
950 	if (likely(!err)) {
951 		bool reset_eval = !ctx->open_rec;
952 
953 		rec = ctx->open_rec;
954 		if (rec) {
955 			msg = &rec->msg_plaintext;
956 			if (!msg->apply_bytes)
957 				reset_eval = true;
958 		}
959 		if (reset_eval) {
960 			psock->eval = __SK_NONE;
961 			if (psock->sk_redir) {
962 				sock_put(psock->sk_redir);
963 				psock->sk_redir = NULL;
964 			}
965 		}
966 		if (rec)
967 			goto more_data;
968 	}
969  out_err:
970 	sk_psock_put(sk, psock);
971 	return err;
972 }
973 
tls_sw_push_pending_record(struct sock * sk,int flags)974 static int tls_sw_push_pending_record(struct sock *sk, int flags)
975 {
976 	struct tls_context *tls_ctx = tls_get_ctx(sk);
977 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
978 	struct tls_rec *rec = ctx->open_rec;
979 	struct sk_msg *msg_pl;
980 	size_t copied;
981 
982 	if (!rec)
983 		return 0;
984 
985 	msg_pl = &rec->msg_plaintext;
986 	copied = msg_pl->sg.size;
987 	if (!copied)
988 		return 0;
989 
990 	return bpf_exec_tx_verdict(msg_pl, sk, true, TLS_RECORD_TYPE_DATA,
991 				   &copied, flags);
992 }
993 
tls_sw_sendmsg_splice(struct sock * sk,struct msghdr * msg,struct sk_msg * msg_pl,size_t try_to_copy,ssize_t * copied)994 static int tls_sw_sendmsg_splice(struct sock *sk, struct msghdr *msg,
995 				 struct sk_msg *msg_pl, size_t try_to_copy,
996 				 ssize_t *copied)
997 {
998 	struct page *page = NULL, **pages = &page;
999 
1000 	do {
1001 		ssize_t part;
1002 		size_t off;
1003 
1004 		part = iov_iter_extract_pages(&msg->msg_iter, &pages,
1005 					      try_to_copy, 1, 0, &off);
1006 		if (part <= 0)
1007 			return part ?: -EIO;
1008 
1009 		if (WARN_ON_ONCE(!sendpage_ok(page))) {
1010 			iov_iter_revert(&msg->msg_iter, part);
1011 			return -EIO;
1012 		}
1013 
1014 		sk_msg_page_add(msg_pl, page, part, off);
1015 		msg_pl->sg.copybreak = 0;
1016 		msg_pl->sg.curr = msg_pl->sg.end;
1017 		sk_mem_charge(sk, part);
1018 		*copied += part;
1019 		try_to_copy -= part;
1020 	} while (try_to_copy && !sk_msg_full(msg_pl));
1021 
1022 	return 0;
1023 }
1024 
tls_sw_sendmsg_locked(struct sock * sk,struct msghdr * msg,size_t size)1025 static int tls_sw_sendmsg_locked(struct sock *sk, struct msghdr *msg,
1026 				 size_t size)
1027 {
1028 	long timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1029 	struct tls_context *tls_ctx = tls_get_ctx(sk);
1030 	struct tls_prot_info *prot = &tls_ctx->prot_info;
1031 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
1032 	bool async_capable = ctx->async_capable;
1033 	unsigned char record_type = TLS_RECORD_TYPE_DATA;
1034 	bool is_kvec = iov_iter_is_kvec(&msg->msg_iter);
1035 	bool eor = !(msg->msg_flags & MSG_MORE);
1036 	size_t try_to_copy;
1037 	ssize_t copied = 0;
1038 	struct sk_msg *msg_pl, *msg_en;
1039 	struct tls_rec *rec;
1040 	int required_size;
1041 	int num_async = 0;
1042 	bool full_record;
1043 	int record_room;
1044 	int num_zc = 0;
1045 	int orig_size;
1046 	int ret = 0;
1047 
1048 	if (!eor && (msg->msg_flags & MSG_EOR))
1049 		return -EINVAL;
1050 
1051 	if (unlikely(msg->msg_controllen)) {
1052 		ret = tls_process_cmsg(sk, msg, &record_type);
1053 		if (ret) {
1054 			if (ret == -EINPROGRESS)
1055 				num_async++;
1056 			else if (ret != -EAGAIN)
1057 				goto send_end;
1058 		}
1059 	}
1060 
1061 	while (msg_data_left(msg)) {
1062 		if (sk->sk_err) {
1063 			ret = -sk->sk_err;
1064 			goto send_end;
1065 		}
1066 
1067 		if (ctx->open_rec)
1068 			rec = ctx->open_rec;
1069 		else
1070 			rec = ctx->open_rec = tls_get_rec(sk);
1071 		if (!rec) {
1072 			ret = -ENOMEM;
1073 			goto send_end;
1074 		}
1075 
1076 		msg_pl = &rec->msg_plaintext;
1077 		msg_en = &rec->msg_encrypted;
1078 
1079 		orig_size = msg_pl->sg.size;
1080 		full_record = false;
1081 		try_to_copy = msg_data_left(msg);
1082 		record_room = TLS_MAX_PAYLOAD_SIZE - msg_pl->sg.size;
1083 		if (try_to_copy >= record_room) {
1084 			try_to_copy = record_room;
1085 			full_record = true;
1086 		}
1087 
1088 		required_size = msg_pl->sg.size + try_to_copy +
1089 				prot->overhead_size;
1090 
1091 		if (!sk_stream_memory_free(sk))
1092 			goto wait_for_sndbuf;
1093 
1094 alloc_encrypted:
1095 		ret = tls_alloc_encrypted_msg(sk, required_size);
1096 		if (ret) {
1097 			if (ret != -ENOSPC)
1098 				goto wait_for_memory;
1099 
1100 			/* Adjust try_to_copy according to the amount that was
1101 			 * actually allocated. The difference is due
1102 			 * to max sg elements limit
1103 			 */
1104 			try_to_copy -= required_size - msg_en->sg.size;
1105 			full_record = true;
1106 		}
1107 
1108 		if (try_to_copy && (msg->msg_flags & MSG_SPLICE_PAGES)) {
1109 			ret = tls_sw_sendmsg_splice(sk, msg, msg_pl,
1110 						    try_to_copy, &copied);
1111 			if (ret < 0)
1112 				goto send_end;
1113 			tls_ctx->pending_open_record_frags = true;
1114 
1115 			if (sk_msg_full(msg_pl))
1116 				full_record = true;
1117 
1118 			if (full_record || eor)
1119 				goto copied;
1120 			continue;
1121 		}
1122 
1123 		if (!is_kvec && (full_record || eor) && !async_capable) {
1124 			u32 first = msg_pl->sg.end;
1125 
1126 			ret = sk_msg_zerocopy_from_iter(sk, &msg->msg_iter,
1127 							msg_pl, try_to_copy);
1128 			if (ret)
1129 				goto fallback_to_reg_send;
1130 
1131 			num_zc++;
1132 			copied += try_to_copy;
1133 
1134 			sk_msg_sg_copy_set(msg_pl, first);
1135 			ret = bpf_exec_tx_verdict(msg_pl, sk, full_record,
1136 						  record_type, &copied,
1137 						  msg->msg_flags);
1138 			if (ret) {
1139 				if (ret == -EINPROGRESS)
1140 					num_async++;
1141 				else if (ret == -ENOMEM)
1142 					goto wait_for_memory;
1143 				else if (ctx->open_rec && ret == -ENOSPC) {
1144 					if (msg_pl->cork_bytes) {
1145 						ret = 0;
1146 						goto send_end;
1147 					}
1148 					goto rollback_iter;
1149 				} else if (ret != -EAGAIN)
1150 					goto send_end;
1151 			}
1152 			continue;
1153 rollback_iter:
1154 			copied -= try_to_copy;
1155 			sk_msg_sg_copy_clear(msg_pl, first);
1156 			iov_iter_revert(&msg->msg_iter,
1157 					msg_pl->sg.size - orig_size);
1158 fallback_to_reg_send:
1159 			sk_msg_trim(sk, msg_pl, orig_size);
1160 		}
1161 
1162 		required_size = msg_pl->sg.size + try_to_copy;
1163 
1164 		ret = tls_clone_plaintext_msg(sk, required_size);
1165 		if (ret) {
1166 			if (ret != -ENOSPC)
1167 				goto send_end;
1168 
1169 			/* Adjust try_to_copy according to the amount that was
1170 			 * actually allocated. The difference is due
1171 			 * to max sg elements limit
1172 			 */
1173 			try_to_copy -= required_size - msg_pl->sg.size;
1174 			full_record = true;
1175 			sk_msg_trim(sk, msg_en,
1176 				    msg_pl->sg.size + prot->overhead_size);
1177 		}
1178 
1179 		if (try_to_copy) {
1180 			ret = sk_msg_memcopy_from_iter(sk, &msg->msg_iter,
1181 						       msg_pl, try_to_copy);
1182 			if (ret < 0)
1183 				goto trim_sgl;
1184 		}
1185 
1186 		/* Open records defined only if successfully copied, otherwise
1187 		 * we would trim the sg but not reset the open record frags.
1188 		 */
1189 		tls_ctx->pending_open_record_frags = true;
1190 		copied += try_to_copy;
1191 copied:
1192 		if (full_record || eor) {
1193 			ret = bpf_exec_tx_verdict(msg_pl, sk, full_record,
1194 						  record_type, &copied,
1195 						  msg->msg_flags);
1196 			if (ret) {
1197 				if (ret == -EINPROGRESS)
1198 					num_async++;
1199 				else if (ret == -ENOMEM)
1200 					goto wait_for_memory;
1201 				else if (ret != -EAGAIN) {
1202 					if (ret == -ENOSPC)
1203 						ret = 0;
1204 					goto send_end;
1205 				}
1206 			}
1207 		}
1208 
1209 		continue;
1210 
1211 wait_for_sndbuf:
1212 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1213 wait_for_memory:
1214 		ret = sk_stream_wait_memory(sk, &timeo);
1215 		if (ret) {
1216 trim_sgl:
1217 			if (ctx->open_rec)
1218 				tls_trim_both_msgs(sk, orig_size);
1219 			goto send_end;
1220 		}
1221 
1222 		if (ctx->open_rec && msg_en->sg.size < required_size)
1223 			goto alloc_encrypted;
1224 	}
1225 
1226 	if (!num_async) {
1227 		goto send_end;
1228 	} else if (num_zc || eor) {
1229 		int err;
1230 
1231 		/* Wait for pending encryptions to get completed */
1232 		err = tls_encrypt_async_wait(ctx);
1233 		if (err) {
1234 			ret = err;
1235 			copied = 0;
1236 		}
1237 	}
1238 
1239 	/* Transmit if any encryptions have completed */
1240 	if (test_and_clear_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask)) {
1241 		cancel_delayed_work(&ctx->tx_work.work);
1242 		tls_tx_records(sk, msg->msg_flags);
1243 	}
1244 
1245 send_end:
1246 	ret = sk_stream_error(sk, msg->msg_flags, ret);
1247 	return copied > 0 ? copied : ret;
1248 }
1249 
tls_sw_sendmsg(struct sock * sk,struct msghdr * msg,size_t size)1250 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
1251 {
1252 	struct tls_context *tls_ctx = tls_get_ctx(sk);
1253 	int ret;
1254 
1255 	if (msg->msg_flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL |
1256 			       MSG_CMSG_COMPAT | MSG_SPLICE_PAGES | MSG_EOR |
1257 			       MSG_SENDPAGE_NOPOLICY))
1258 		return -EOPNOTSUPP;
1259 
1260 	ret = mutex_lock_interruptible(&tls_ctx->tx_lock);
1261 	if (ret)
1262 		return ret;
1263 	lock_sock(sk);
1264 	ret = tls_sw_sendmsg_locked(sk, msg, size);
1265 	release_sock(sk);
1266 	mutex_unlock(&tls_ctx->tx_lock);
1267 	return ret;
1268 }
1269 
1270 /*
1271  * Handle unexpected EOF during splice without SPLICE_F_MORE set.
1272  */
tls_sw_splice_eof(struct socket * sock)1273 void tls_sw_splice_eof(struct socket *sock)
1274 {
1275 	struct sock *sk = sock->sk;
1276 	struct tls_context *tls_ctx = tls_get_ctx(sk);
1277 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
1278 	struct tls_rec *rec;
1279 	struct sk_msg *msg_pl;
1280 	ssize_t copied = 0;
1281 	bool retrying = false;
1282 	int ret = 0;
1283 
1284 	if (!ctx->open_rec)
1285 		return;
1286 
1287 	mutex_lock(&tls_ctx->tx_lock);
1288 	lock_sock(sk);
1289 
1290 retry:
1291 	/* same checks as in tls_sw_push_pending_record() */
1292 	rec = ctx->open_rec;
1293 	if (!rec)
1294 		goto unlock;
1295 
1296 	msg_pl = &rec->msg_plaintext;
1297 	if (msg_pl->sg.size == 0)
1298 		goto unlock;
1299 
1300 	/* Check the BPF advisor and perform transmission. */
1301 	ret = bpf_exec_tx_verdict(msg_pl, sk, false, TLS_RECORD_TYPE_DATA,
1302 				  &copied, 0);
1303 	switch (ret) {
1304 	case 0:
1305 	case -EAGAIN:
1306 		if (retrying)
1307 			goto unlock;
1308 		retrying = true;
1309 		goto retry;
1310 	case -EINPROGRESS:
1311 		break;
1312 	default:
1313 		goto unlock;
1314 	}
1315 
1316 	/* Wait for pending encryptions to get completed */
1317 	if (tls_encrypt_async_wait(ctx))
1318 		goto unlock;
1319 
1320 	/* Transmit if any encryptions have completed */
1321 	if (test_and_clear_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask)) {
1322 		cancel_delayed_work(&ctx->tx_work.work);
1323 		tls_tx_records(sk, 0);
1324 	}
1325 
1326 unlock:
1327 	release_sock(sk);
1328 	mutex_unlock(&tls_ctx->tx_lock);
1329 }
1330 
1331 static int
tls_rx_rec_wait(struct sock * sk,struct sk_psock * psock,bool nonblock,bool released)1332 tls_rx_rec_wait(struct sock *sk, struct sk_psock *psock, bool nonblock,
1333 		bool released)
1334 {
1335 	struct tls_context *tls_ctx = tls_get_ctx(sk);
1336 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
1337 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
1338 	int ret = 0;
1339 	long timeo;
1340 
1341 	/* a rekey is pending, let userspace deal with it */
1342 	if (unlikely(ctx->key_update_pending))
1343 		return -EKEYEXPIRED;
1344 
1345 	timeo = sock_rcvtimeo(sk, nonblock);
1346 
1347 	while (!tls_strp_msg_ready(ctx)) {
1348 		if (!sk_psock_queue_empty(psock))
1349 			return 0;
1350 
1351 		if (sk->sk_err)
1352 			return sock_error(sk);
1353 
1354 		if (ret < 0)
1355 			return ret;
1356 
1357 		if (!skb_queue_empty(&sk->sk_receive_queue)) {
1358 			tls_strp_check_rcv(&ctx->strp);
1359 			if (tls_strp_msg_ready(ctx))
1360 				break;
1361 		}
1362 
1363 		if (sk->sk_shutdown & RCV_SHUTDOWN)
1364 			return 0;
1365 
1366 		if (sock_flag(sk, SOCK_DONE))
1367 			return 0;
1368 
1369 		if (!timeo)
1370 			return -EAGAIN;
1371 
1372 		released = true;
1373 		add_wait_queue(sk_sleep(sk), &wait);
1374 		sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
1375 		ret = sk_wait_event(sk, &timeo,
1376 				    tls_strp_msg_ready(ctx) ||
1377 				    !sk_psock_queue_empty(psock),
1378 				    &wait);
1379 		sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
1380 		remove_wait_queue(sk_sleep(sk), &wait);
1381 
1382 		/* Handle signals */
1383 		if (signal_pending(current))
1384 			return sock_intr_errno(timeo);
1385 	}
1386 
1387 	if (unlikely(!tls_strp_msg_load(&ctx->strp, released)))
1388 		return tls_rx_rec_wait(sk, psock, nonblock, false);
1389 
1390 	return 1;
1391 }
1392 
tls_setup_from_iter(struct iov_iter * from,int length,int * pages_used,struct scatterlist * to,int to_max_pages)1393 static int tls_setup_from_iter(struct iov_iter *from,
1394 			       int length, int *pages_used,
1395 			       struct scatterlist *to,
1396 			       int to_max_pages)
1397 {
1398 	int rc = 0, i = 0, num_elem = *pages_used, maxpages;
1399 	struct page *pages[MAX_SKB_FRAGS];
1400 	unsigned int size = 0;
1401 	ssize_t copied, use;
1402 	size_t offset;
1403 
1404 	while (length > 0) {
1405 		i = 0;
1406 		maxpages = to_max_pages - num_elem;
1407 		if (maxpages == 0) {
1408 			rc = -EFAULT;
1409 			goto out;
1410 		}
1411 		copied = iov_iter_get_pages2(from, pages,
1412 					    length,
1413 					    maxpages, &offset);
1414 		if (copied <= 0) {
1415 			rc = -EFAULT;
1416 			goto out;
1417 		}
1418 
1419 		length -= copied;
1420 		size += copied;
1421 		while (copied) {
1422 			use = min_t(int, copied, PAGE_SIZE - offset);
1423 
1424 			sg_set_page(&to[num_elem],
1425 				    pages[i], use, offset);
1426 			sg_unmark_end(&to[num_elem]);
1427 			/* We do not uncharge memory from this API */
1428 
1429 			offset = 0;
1430 			copied -= use;
1431 
1432 			i++;
1433 			num_elem++;
1434 		}
1435 	}
1436 	/* Mark the end in the last sg entry if newly added */
1437 	if (num_elem > *pages_used)
1438 		sg_mark_end(&to[num_elem - 1]);
1439 out:
1440 	if (rc)
1441 		iov_iter_revert(from, size);
1442 	*pages_used = num_elem;
1443 
1444 	return rc;
1445 }
1446 
1447 static struct sk_buff *
tls_alloc_clrtxt_skb(struct sock * sk,struct sk_buff * skb,unsigned int full_len)1448 tls_alloc_clrtxt_skb(struct sock *sk, struct sk_buff *skb,
1449 		     unsigned int full_len)
1450 {
1451 	struct strp_msg *clr_rxm;
1452 	struct sk_buff *clr_skb;
1453 	int err;
1454 
1455 	clr_skb = alloc_skb_with_frags(0, full_len, TLS_PAGE_ORDER,
1456 				       &err, sk->sk_allocation);
1457 	if (!clr_skb)
1458 		return NULL;
1459 
1460 	skb_copy_header(clr_skb, skb);
1461 	clr_skb->len = full_len;
1462 	clr_skb->data_len = full_len;
1463 
1464 	clr_rxm = strp_msg(clr_skb);
1465 	clr_rxm->offset = 0;
1466 
1467 	return clr_skb;
1468 }
1469 
1470 /* Decrypt handlers
1471  *
1472  * tls_decrypt_sw() and tls_decrypt_device() are decrypt handlers.
1473  * They must transform the darg in/out argument are as follows:
1474  *       |          Input            |         Output
1475  * -------------------------------------------------------------------
1476  *    zc | Zero-copy decrypt allowed | Zero-copy performed
1477  * async | Async decrypt allowed     | Async crypto used / in progress
1478  *   skb |            *              | Output skb
1479  *
1480  * If ZC decryption was performed darg.skb will point to the input skb.
1481  */
1482 
1483 /* This function decrypts the input skb into either out_iov or in out_sg
1484  * or in skb buffers itself. The input parameter 'darg->zc' indicates if
1485  * zero-copy mode needs to be tried or not. With zero-copy mode, either
1486  * out_iov or out_sg must be non-NULL. In case both out_iov and out_sg are
1487  * NULL, then the decryption happens inside skb buffers itself, i.e.
1488  * zero-copy gets disabled and 'darg->zc' is updated.
1489  */
tls_decrypt_sg(struct sock * sk,struct iov_iter * out_iov,struct scatterlist * out_sg,struct tls_decrypt_arg * darg)1490 static int tls_decrypt_sg(struct sock *sk, struct iov_iter *out_iov,
1491 			  struct scatterlist *out_sg,
1492 			  struct tls_decrypt_arg *darg)
1493 {
1494 	struct tls_context *tls_ctx = tls_get_ctx(sk);
1495 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
1496 	struct tls_prot_info *prot = &tls_ctx->prot_info;
1497 	int n_sgin, n_sgout, aead_size, err, pages = 0;
1498 	struct sk_buff *skb = tls_strp_msg(ctx);
1499 	const struct strp_msg *rxm = strp_msg(skb);
1500 	const struct tls_msg *tlm = tls_msg(skb);
1501 	struct aead_request *aead_req;
1502 	struct scatterlist *sgin = NULL;
1503 	struct scatterlist *sgout = NULL;
1504 	const int data_len = rxm->full_len - prot->overhead_size;
1505 	int tail_pages = !!prot->tail_size;
1506 	struct tls_decrypt_ctx *dctx;
1507 	struct sk_buff *clear_skb;
1508 	int iv_offset = 0;
1509 	u8 *mem;
1510 
1511 	n_sgin = skb_nsg(skb, rxm->offset + prot->prepend_size,
1512 			 rxm->full_len - prot->prepend_size);
1513 	if (n_sgin < 1)
1514 		return n_sgin ?: -EBADMSG;
1515 
1516 	if (darg->zc && (out_iov || out_sg)) {
1517 		clear_skb = NULL;
1518 
1519 		if (out_iov)
1520 			n_sgout = 1 + tail_pages +
1521 				iov_iter_npages_cap(out_iov, INT_MAX, data_len);
1522 		else
1523 			n_sgout = sg_nents(out_sg);
1524 	} else {
1525 		darg->zc = false;
1526 
1527 		clear_skb = tls_alloc_clrtxt_skb(sk, skb, rxm->full_len);
1528 		if (!clear_skb)
1529 			return -ENOMEM;
1530 
1531 		n_sgout = 1 + skb_shinfo(clear_skb)->nr_frags;
1532 	}
1533 
1534 	/* Increment to accommodate AAD */
1535 	n_sgin = n_sgin + 1;
1536 
1537 	/* Allocate a single block of memory which contains
1538 	 *   aead_req || tls_decrypt_ctx.
1539 	 * Both structs are variable length.
1540 	 */
1541 	aead_size = sizeof(*aead_req) + crypto_aead_reqsize(ctx->aead_recv);
1542 	aead_size = ALIGN(aead_size, __alignof__(*dctx));
1543 	mem = kmalloc(aead_size + struct_size(dctx, sg, size_add(n_sgin, n_sgout)),
1544 		      sk->sk_allocation);
1545 	if (!mem) {
1546 		err = -ENOMEM;
1547 		goto exit_free_skb;
1548 	}
1549 
1550 	/* Segment the allocated memory */
1551 	aead_req = (struct aead_request *)mem;
1552 	dctx = (struct tls_decrypt_ctx *)(mem + aead_size);
1553 	dctx->sk = sk;
1554 	sgin = &dctx->sg[0];
1555 	sgout = &dctx->sg[n_sgin];
1556 
1557 	/* For CCM based ciphers, first byte of nonce+iv is a constant */
1558 	switch (prot->cipher_type) {
1559 	case TLS_CIPHER_AES_CCM_128:
1560 		dctx->iv[0] = TLS_AES_CCM_IV_B0_BYTE;
1561 		iv_offset = 1;
1562 		break;
1563 	case TLS_CIPHER_SM4_CCM:
1564 		dctx->iv[0] = TLS_SM4_CCM_IV_B0_BYTE;
1565 		iv_offset = 1;
1566 		break;
1567 	}
1568 
1569 	/* Prepare IV */
1570 	if (prot->version == TLS_1_3_VERSION ||
1571 	    prot->cipher_type == TLS_CIPHER_CHACHA20_POLY1305) {
1572 		memcpy(&dctx->iv[iv_offset], tls_ctx->rx.iv,
1573 		       prot->iv_size + prot->salt_size);
1574 	} else {
1575 		err = skb_copy_bits(skb, rxm->offset + TLS_HEADER_SIZE,
1576 				    &dctx->iv[iv_offset] + prot->salt_size,
1577 				    prot->iv_size);
1578 		if (err < 0)
1579 			goto exit_free;
1580 		memcpy(&dctx->iv[iv_offset], tls_ctx->rx.iv, prot->salt_size);
1581 	}
1582 	tls_xor_iv_with_seq(prot, &dctx->iv[iv_offset], tls_ctx->rx.rec_seq);
1583 
1584 	/* Prepare AAD */
1585 	tls_make_aad(dctx->aad, rxm->full_len - prot->overhead_size +
1586 		     prot->tail_size,
1587 		     tls_ctx->rx.rec_seq, tlm->control, prot);
1588 
1589 	/* Prepare sgin */
1590 	sg_init_table(sgin, n_sgin);
1591 	sg_set_buf(&sgin[0], dctx->aad, prot->aad_size);
1592 	err = skb_to_sgvec(skb, &sgin[1],
1593 			   rxm->offset + prot->prepend_size,
1594 			   rxm->full_len - prot->prepend_size);
1595 	if (err < 0)
1596 		goto exit_free;
1597 
1598 	if (clear_skb) {
1599 		sg_init_table(sgout, n_sgout);
1600 		sg_set_buf(&sgout[0], dctx->aad, prot->aad_size);
1601 
1602 		err = skb_to_sgvec(clear_skb, &sgout[1], prot->prepend_size,
1603 				   data_len + prot->tail_size);
1604 		if (err < 0)
1605 			goto exit_free;
1606 	} else if (out_iov) {
1607 		sg_init_table(sgout, n_sgout);
1608 		sg_set_buf(&sgout[0], dctx->aad, prot->aad_size);
1609 
1610 		err = tls_setup_from_iter(out_iov, data_len, &pages, &sgout[1],
1611 					  (n_sgout - 1 - tail_pages));
1612 		if (err < 0)
1613 			goto exit_free_pages;
1614 
1615 		if (prot->tail_size) {
1616 			sg_unmark_end(&sgout[pages]);
1617 			sg_set_buf(&sgout[pages + 1], &dctx->tail,
1618 				   prot->tail_size);
1619 			sg_mark_end(&sgout[pages + 1]);
1620 		}
1621 	} else if (out_sg) {
1622 		memcpy(sgout, out_sg, n_sgout * sizeof(*sgout));
1623 	}
1624 	dctx->free_sgout = !!pages;
1625 
1626 	/* Prepare and submit AEAD request */
1627 	err = tls_do_decryption(sk, sgin, sgout, dctx->iv,
1628 				data_len + prot->tail_size, aead_req, darg);
1629 	if (err) {
1630 		if (darg->async_done)
1631 			goto exit_free_skb;
1632 		goto exit_free_pages;
1633 	}
1634 
1635 	darg->skb = clear_skb ?: tls_strp_msg(ctx);
1636 	clear_skb = NULL;
1637 
1638 	if (unlikely(darg->async)) {
1639 		err = tls_strp_msg_hold(&ctx->strp, &ctx->async_hold);
1640 		if (err)
1641 			__skb_queue_tail(&ctx->async_hold, darg->skb);
1642 		return err;
1643 	}
1644 
1645 	if (unlikely(darg->async_done))
1646 		return 0;
1647 
1648 	if (prot->tail_size)
1649 		darg->tail = dctx->tail;
1650 
1651 exit_free_pages:
1652 	/* Release the pages in case iov was mapped to pages */
1653 	for (; pages > 0; pages--)
1654 		put_page(sg_page(&sgout[pages]));
1655 exit_free:
1656 	kfree(mem);
1657 exit_free_skb:
1658 	consume_skb(clear_skb);
1659 	return err;
1660 }
1661 
1662 static int
tls_decrypt_sw(struct sock * sk,struct tls_context * tls_ctx,struct msghdr * msg,struct tls_decrypt_arg * darg)1663 tls_decrypt_sw(struct sock *sk, struct tls_context *tls_ctx,
1664 	       struct msghdr *msg, struct tls_decrypt_arg *darg)
1665 {
1666 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
1667 	struct tls_prot_info *prot = &tls_ctx->prot_info;
1668 	struct strp_msg *rxm;
1669 	int pad, err;
1670 
1671 	err = tls_decrypt_sg(sk, &msg->msg_iter, NULL, darg);
1672 	if (err < 0) {
1673 		if (err == -EBADMSG)
1674 			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSDECRYPTERROR);
1675 		return err;
1676 	}
1677 	/* keep going even for ->async, the code below is TLS 1.3 */
1678 
1679 	/* If opportunistic TLS 1.3 ZC failed retry without ZC */
1680 	if (unlikely(darg->zc && prot->version == TLS_1_3_VERSION &&
1681 		     darg->tail != TLS_RECORD_TYPE_DATA)) {
1682 		darg->zc = false;
1683 		if (!darg->tail)
1684 			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSRXNOPADVIOL);
1685 		TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSDECRYPTRETRY);
1686 		return tls_decrypt_sw(sk, tls_ctx, msg, darg);
1687 	}
1688 
1689 	pad = tls_padding_length(prot, darg->skb, darg);
1690 	if (pad < 0) {
1691 		if (darg->skb != tls_strp_msg(ctx))
1692 			consume_skb(darg->skb);
1693 		return pad;
1694 	}
1695 
1696 	rxm = strp_msg(darg->skb);
1697 	rxm->full_len -= pad;
1698 
1699 	return 0;
1700 }
1701 
1702 static int
tls_decrypt_device(struct sock * sk,struct msghdr * msg,struct tls_context * tls_ctx,struct tls_decrypt_arg * darg)1703 tls_decrypt_device(struct sock *sk, struct msghdr *msg,
1704 		   struct tls_context *tls_ctx, struct tls_decrypt_arg *darg)
1705 {
1706 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
1707 	struct tls_prot_info *prot = &tls_ctx->prot_info;
1708 	struct strp_msg *rxm;
1709 	int pad, err;
1710 
1711 	if (tls_ctx->rx_conf != TLS_HW)
1712 		return 0;
1713 
1714 	err = tls_device_decrypted(sk, tls_ctx);
1715 	if (err <= 0)
1716 		return err;
1717 
1718 	pad = tls_padding_length(prot, tls_strp_msg(ctx), darg);
1719 	if (pad < 0)
1720 		return pad;
1721 
1722 	darg->async = false;
1723 	darg->skb = tls_strp_msg(ctx);
1724 	/* ->zc downgrade check, in case TLS 1.3 gets here */
1725 	darg->zc &= !(prot->version == TLS_1_3_VERSION &&
1726 		      tls_msg(darg->skb)->control != TLS_RECORD_TYPE_DATA);
1727 
1728 	rxm = strp_msg(darg->skb);
1729 	rxm->full_len -= pad;
1730 
1731 	if (!darg->zc) {
1732 		/* Non-ZC case needs a real skb */
1733 		darg->skb = tls_strp_msg_detach(ctx);
1734 		if (!darg->skb)
1735 			return -ENOMEM;
1736 	} else {
1737 		unsigned int off, len;
1738 
1739 		/* In ZC case nobody cares about the output skb.
1740 		 * Just copy the data here. Note the skb is not fully trimmed.
1741 		 */
1742 		off = rxm->offset + prot->prepend_size;
1743 		len = rxm->full_len - prot->overhead_size;
1744 
1745 		err = skb_copy_datagram_msg(darg->skb, off, msg, len);
1746 		if (err)
1747 			return err;
1748 	}
1749 	return 1;
1750 }
1751 
tls_check_pending_rekey(struct sock * sk,struct tls_context * ctx,struct sk_buff * skb)1752 static int tls_check_pending_rekey(struct sock *sk, struct tls_context *ctx,
1753 				   struct sk_buff *skb)
1754 {
1755 	const struct strp_msg *rxm = strp_msg(skb);
1756 	const struct tls_msg *tlm = tls_msg(skb);
1757 	char hs_type;
1758 	int err;
1759 
1760 	if (likely(tlm->control != TLS_RECORD_TYPE_HANDSHAKE))
1761 		return 0;
1762 
1763 	if (rxm->full_len < 1)
1764 		return 0;
1765 
1766 	err = skb_copy_bits(skb, rxm->offset, &hs_type, 1);
1767 	if (err < 0) {
1768 		DEBUG_NET_WARN_ON_ONCE(1);
1769 		return err;
1770 	}
1771 
1772 	if (hs_type == TLS_HANDSHAKE_KEYUPDATE) {
1773 		struct tls_sw_context_rx *rx_ctx = ctx->priv_ctx_rx;
1774 
1775 		WRITE_ONCE(rx_ctx->key_update_pending, true);
1776 		TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSRXREKEYRECEIVED);
1777 	}
1778 
1779 	return 0;
1780 }
1781 
tls_rx_one_record(struct sock * sk,struct msghdr * msg,struct tls_decrypt_arg * darg)1782 static int tls_rx_one_record(struct sock *sk, struct msghdr *msg,
1783 			     struct tls_decrypt_arg *darg)
1784 {
1785 	struct tls_context *tls_ctx = tls_get_ctx(sk);
1786 	struct tls_prot_info *prot = &tls_ctx->prot_info;
1787 	struct strp_msg *rxm;
1788 	int err;
1789 
1790 	err = tls_decrypt_device(sk, msg, tls_ctx, darg);
1791 	if (!err)
1792 		err = tls_decrypt_sw(sk, tls_ctx, msg, darg);
1793 	if (err < 0)
1794 		return err;
1795 
1796 	rxm = strp_msg(darg->skb);
1797 	rxm->offset += prot->prepend_size;
1798 	rxm->full_len -= prot->overhead_size;
1799 	tls_advance_record_sn(sk, prot, &tls_ctx->rx);
1800 
1801 	return tls_check_pending_rekey(sk, tls_ctx, darg->skb);
1802 }
1803 
decrypt_skb(struct sock * sk,struct scatterlist * sgout)1804 int decrypt_skb(struct sock *sk, struct scatterlist *sgout)
1805 {
1806 	struct tls_decrypt_arg darg = { .zc = true, };
1807 
1808 	return tls_decrypt_sg(sk, NULL, sgout, &darg);
1809 }
1810 
1811 /* All records returned from a recvmsg() call must have the same type.
1812  * 0 is not a valid content type. Use it as "no type reported, yet".
1813  */
tls_record_content_type(struct msghdr * msg,struct tls_msg * tlm,u8 * control)1814 static int tls_record_content_type(struct msghdr *msg, struct tls_msg *tlm,
1815 				   u8 *control)
1816 {
1817 	int err;
1818 
1819 	if (!*control) {
1820 		*control = tlm->control;
1821 		if (!*control)
1822 			return -EBADMSG;
1823 
1824 		err = put_cmsg(msg, SOL_TLS, TLS_GET_RECORD_TYPE,
1825 			       sizeof(*control), control);
1826 		if (*control != TLS_RECORD_TYPE_DATA) {
1827 			if (err || msg->msg_flags & MSG_CTRUNC)
1828 				return -EIO;
1829 		}
1830 	} else if (*control != tlm->control) {
1831 		return 0;
1832 	}
1833 
1834 	return 1;
1835 }
1836 
tls_rx_rec_done(struct tls_sw_context_rx * ctx)1837 static void tls_rx_rec_done(struct tls_sw_context_rx *ctx)
1838 {
1839 	tls_strp_msg_done(&ctx->strp);
1840 }
1841 
1842 /* This function traverses the rx_list in tls receive context to copies the
1843  * decrypted records into the buffer provided by caller zero copy is not
1844  * true. Further, the records are removed from the rx_list if it is not a peek
1845  * case and the record has been consumed completely.
1846  */
process_rx_list(struct tls_sw_context_rx * ctx,struct msghdr * msg,u8 * control,size_t skip,size_t len,bool is_peek,bool * more)1847 static int process_rx_list(struct tls_sw_context_rx *ctx,
1848 			   struct msghdr *msg,
1849 			   u8 *control,
1850 			   size_t skip,
1851 			   size_t len,
1852 			   bool is_peek,
1853 			   bool *more)
1854 {
1855 	struct sk_buff *skb = skb_peek(&ctx->rx_list);
1856 	struct tls_msg *tlm;
1857 	ssize_t copied = 0;
1858 	int err;
1859 
1860 	while (skip && skb) {
1861 		struct strp_msg *rxm = strp_msg(skb);
1862 		tlm = tls_msg(skb);
1863 
1864 		err = tls_record_content_type(msg, tlm, control);
1865 		if (err <= 0)
1866 			goto more;
1867 
1868 		if (skip < rxm->full_len)
1869 			break;
1870 
1871 		skip = skip - rxm->full_len;
1872 		skb = skb_peek_next(skb, &ctx->rx_list);
1873 	}
1874 
1875 	while (len && skb) {
1876 		struct sk_buff *next_skb;
1877 		struct strp_msg *rxm = strp_msg(skb);
1878 		int chunk = min_t(unsigned int, rxm->full_len - skip, len);
1879 
1880 		tlm = tls_msg(skb);
1881 
1882 		err = tls_record_content_type(msg, tlm, control);
1883 		if (err <= 0)
1884 			goto more;
1885 
1886 		err = skb_copy_datagram_msg(skb, rxm->offset + skip,
1887 					    msg, chunk);
1888 		if (err < 0)
1889 			goto more;
1890 
1891 		len = len - chunk;
1892 		copied = copied + chunk;
1893 
1894 		/* Consume the data from record if it is non-peek case*/
1895 		if (!is_peek) {
1896 			rxm->offset = rxm->offset + chunk;
1897 			rxm->full_len = rxm->full_len - chunk;
1898 
1899 			/* Return if there is unconsumed data in the record */
1900 			if (rxm->full_len - skip)
1901 				break;
1902 		}
1903 
1904 		/* The remaining skip-bytes must lie in 1st record in rx_list.
1905 		 * So from the 2nd record, 'skip' should be 0.
1906 		 */
1907 		skip = 0;
1908 
1909 		if (msg)
1910 			msg->msg_flags |= MSG_EOR;
1911 
1912 		next_skb = skb_peek_next(skb, &ctx->rx_list);
1913 
1914 		if (!is_peek) {
1915 			__skb_unlink(skb, &ctx->rx_list);
1916 			consume_skb(skb);
1917 		}
1918 
1919 		skb = next_skb;
1920 	}
1921 	err = 0;
1922 
1923 out:
1924 	return copied ? : err;
1925 more:
1926 	if (more)
1927 		*more = true;
1928 	goto out;
1929 }
1930 
1931 static bool
tls_read_flush_backlog(struct sock * sk,struct tls_prot_info * prot,size_t len_left,size_t decrypted,ssize_t done,size_t * flushed_at)1932 tls_read_flush_backlog(struct sock *sk, struct tls_prot_info *prot,
1933 		       size_t len_left, size_t decrypted, ssize_t done,
1934 		       size_t *flushed_at)
1935 {
1936 	size_t max_rec;
1937 
1938 	if (len_left <= decrypted)
1939 		return false;
1940 
1941 	max_rec = prot->overhead_size - prot->tail_size + TLS_MAX_PAYLOAD_SIZE;
1942 	if (done - *flushed_at < SZ_128K && tcp_inq(sk) > max_rec)
1943 		return false;
1944 
1945 	*flushed_at = done;
1946 	return sk_flush_backlog(sk);
1947 }
1948 
tls_rx_reader_acquire(struct sock * sk,struct tls_sw_context_rx * ctx,bool nonblock)1949 static int tls_rx_reader_acquire(struct sock *sk, struct tls_sw_context_rx *ctx,
1950 				 bool nonblock)
1951 {
1952 	long timeo;
1953 	int ret;
1954 
1955 	timeo = sock_rcvtimeo(sk, nonblock);
1956 
1957 	while (unlikely(ctx->reader_present)) {
1958 		DEFINE_WAIT_FUNC(wait, woken_wake_function);
1959 
1960 		ctx->reader_contended = 1;
1961 
1962 		add_wait_queue(&ctx->wq, &wait);
1963 		ret = sk_wait_event(sk, &timeo,
1964 				    !READ_ONCE(ctx->reader_present), &wait);
1965 		remove_wait_queue(&ctx->wq, &wait);
1966 
1967 		if (timeo <= 0)
1968 			return -EAGAIN;
1969 		if (signal_pending(current))
1970 			return sock_intr_errno(timeo);
1971 		if (ret < 0)
1972 			return ret;
1973 	}
1974 
1975 	WRITE_ONCE(ctx->reader_present, 1);
1976 
1977 	return 0;
1978 }
1979 
tls_rx_reader_lock(struct sock * sk,struct tls_sw_context_rx * ctx,bool nonblock)1980 static int tls_rx_reader_lock(struct sock *sk, struct tls_sw_context_rx *ctx,
1981 			      bool nonblock)
1982 {
1983 	int err;
1984 
1985 	lock_sock(sk);
1986 	err = tls_rx_reader_acquire(sk, ctx, nonblock);
1987 	if (err)
1988 		release_sock(sk);
1989 	return err;
1990 }
1991 
tls_rx_reader_release(struct sock * sk,struct tls_sw_context_rx * ctx)1992 static void tls_rx_reader_release(struct sock *sk, struct tls_sw_context_rx *ctx)
1993 {
1994 	if (unlikely(ctx->reader_contended)) {
1995 		if (wq_has_sleeper(&ctx->wq))
1996 			wake_up(&ctx->wq);
1997 		else
1998 			ctx->reader_contended = 0;
1999 
2000 		WARN_ON_ONCE(!ctx->reader_present);
2001 	}
2002 
2003 	WRITE_ONCE(ctx->reader_present, 0);
2004 }
2005 
tls_rx_reader_unlock(struct sock * sk,struct tls_sw_context_rx * ctx)2006 static void tls_rx_reader_unlock(struct sock *sk, struct tls_sw_context_rx *ctx)
2007 {
2008 	tls_rx_reader_release(sk, ctx);
2009 	release_sock(sk);
2010 }
2011 
tls_sw_recvmsg(struct sock * sk,struct msghdr * msg,size_t len,int flags,int * addr_len)2012 int tls_sw_recvmsg(struct sock *sk,
2013 		   struct msghdr *msg,
2014 		   size_t len,
2015 		   int flags,
2016 		   int *addr_len)
2017 {
2018 	struct tls_context *tls_ctx = tls_get_ctx(sk);
2019 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
2020 	struct tls_prot_info *prot = &tls_ctx->prot_info;
2021 	ssize_t decrypted = 0, async_copy_bytes = 0;
2022 	struct sk_psock *psock;
2023 	unsigned char control = 0;
2024 	size_t flushed_at = 0;
2025 	struct strp_msg *rxm;
2026 	struct tls_msg *tlm;
2027 	ssize_t copied = 0;
2028 	ssize_t peeked = 0;
2029 	bool async = false;
2030 	int target, err;
2031 	bool is_kvec = iov_iter_is_kvec(&msg->msg_iter);
2032 	bool is_peek = flags & MSG_PEEK;
2033 	bool rx_more = false;
2034 	bool released = true;
2035 	bool bpf_strp_enabled;
2036 	bool zc_capable;
2037 
2038 	if (unlikely(flags & MSG_ERRQUEUE))
2039 		return sock_recv_errqueue(sk, msg, len, SOL_IP, IP_RECVERR);
2040 
2041 	err = tls_rx_reader_lock(sk, ctx, flags & MSG_DONTWAIT);
2042 	if (err < 0)
2043 		return err;
2044 	psock = sk_psock_get(sk);
2045 	bpf_strp_enabled = sk_psock_strp_enabled(psock);
2046 
2047 	/* If crypto failed the connection is broken */
2048 	err = ctx->async_wait.err;
2049 	if (err)
2050 		goto end;
2051 
2052 	/* Process pending decrypted records. It must be non-zero-copy */
2053 	err = process_rx_list(ctx, msg, &control, 0, len, is_peek, &rx_more);
2054 	if (err < 0)
2055 		goto end;
2056 
2057 	/* process_rx_list() will set @control if it processed any records */
2058 	copied = err;
2059 	if (len <= copied || rx_more ||
2060 	    (control && control != TLS_RECORD_TYPE_DATA))
2061 		goto end;
2062 
2063 	target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
2064 	len = len - copied;
2065 
2066 	zc_capable = !bpf_strp_enabled && !is_kvec && !is_peek &&
2067 		ctx->zc_capable;
2068 	decrypted = 0;
2069 	while (len && (decrypted + copied < target || tls_strp_msg_ready(ctx))) {
2070 		struct tls_decrypt_arg darg;
2071 		int to_decrypt, chunk;
2072 
2073 		err = tls_rx_rec_wait(sk, psock, flags & MSG_DONTWAIT,
2074 				      released);
2075 		if (err <= 0) {
2076 			if (psock) {
2077 				chunk = sk_msg_recvmsg(sk, psock, msg, len,
2078 						       flags);
2079 				if (chunk > 0) {
2080 					decrypted += chunk;
2081 					len -= chunk;
2082 					continue;
2083 				}
2084 			}
2085 			goto recv_end;
2086 		}
2087 
2088 		memset(&darg.inargs, 0, sizeof(darg.inargs));
2089 
2090 		rxm = strp_msg(tls_strp_msg(ctx));
2091 		tlm = tls_msg(tls_strp_msg(ctx));
2092 
2093 		to_decrypt = rxm->full_len - prot->overhead_size;
2094 
2095 		if (zc_capable && to_decrypt <= len &&
2096 		    tlm->control == TLS_RECORD_TYPE_DATA)
2097 			darg.zc = true;
2098 
2099 		/* Do not use async mode if record is non-data */
2100 		if (tlm->control == TLS_RECORD_TYPE_DATA && !bpf_strp_enabled)
2101 			darg.async = ctx->async_capable;
2102 		else
2103 			darg.async = false;
2104 
2105 		err = tls_rx_one_record(sk, msg, &darg);
2106 		if (err < 0) {
2107 			tls_err_abort(sk, -EBADMSG);
2108 			goto recv_end;
2109 		}
2110 
2111 		async |= darg.async;
2112 
2113 		/* If the type of records being processed is not known yet,
2114 		 * set it to record type just dequeued. If it is already known,
2115 		 * but does not match the record type just dequeued, go to end.
2116 		 * We always get record type here since for tls1.2, record type
2117 		 * is known just after record is dequeued from stream parser.
2118 		 * For tls1.3, we disable async.
2119 		 */
2120 		err = tls_record_content_type(msg, tls_msg(darg.skb), &control);
2121 		if (err <= 0) {
2122 			DEBUG_NET_WARN_ON_ONCE(darg.zc);
2123 			tls_rx_rec_done(ctx);
2124 put_on_rx_list_err:
2125 			__skb_queue_tail(&ctx->rx_list, darg.skb);
2126 			goto recv_end;
2127 		}
2128 
2129 		/* periodically flush backlog, and feed strparser */
2130 		released = tls_read_flush_backlog(sk, prot, len, to_decrypt,
2131 						  decrypted + copied,
2132 						  &flushed_at);
2133 
2134 		/* TLS 1.3 may have updated the length by more than overhead */
2135 		rxm = strp_msg(darg.skb);
2136 		chunk = rxm->full_len;
2137 		tls_rx_rec_done(ctx);
2138 
2139 		if (!darg.zc) {
2140 			bool partially_consumed = chunk > len;
2141 			struct sk_buff *skb = darg.skb;
2142 
2143 			DEBUG_NET_WARN_ON_ONCE(darg.skb == ctx->strp.anchor);
2144 
2145 			if (async) {
2146 				/* TLS 1.2-only, to_decrypt must be text len */
2147 				chunk = min_t(int, to_decrypt, len);
2148 				async_copy_bytes += chunk;
2149 put_on_rx_list:
2150 				decrypted += chunk;
2151 				len -= chunk;
2152 				__skb_queue_tail(&ctx->rx_list, skb);
2153 				if (unlikely(control != TLS_RECORD_TYPE_DATA))
2154 					break;
2155 				continue;
2156 			}
2157 
2158 			if (bpf_strp_enabled) {
2159 				released = true;
2160 				err = sk_psock_tls_strp_read(psock, skb);
2161 				if (err != __SK_PASS) {
2162 					rxm->offset = rxm->offset + rxm->full_len;
2163 					rxm->full_len = 0;
2164 					if (err == __SK_DROP)
2165 						consume_skb(skb);
2166 					continue;
2167 				}
2168 			}
2169 
2170 			if (partially_consumed)
2171 				chunk = len;
2172 
2173 			err = skb_copy_datagram_msg(skb, rxm->offset,
2174 						    msg, chunk);
2175 			if (err < 0)
2176 				goto put_on_rx_list_err;
2177 
2178 			if (is_peek) {
2179 				peeked += chunk;
2180 				goto put_on_rx_list;
2181 			}
2182 
2183 			if (partially_consumed) {
2184 				rxm->offset += chunk;
2185 				rxm->full_len -= chunk;
2186 				goto put_on_rx_list;
2187 			}
2188 
2189 			consume_skb(skb);
2190 		}
2191 
2192 		decrypted += chunk;
2193 		len -= chunk;
2194 
2195 		/* Return full control message to userspace before trying
2196 		 * to parse another message type
2197 		 */
2198 		msg->msg_flags |= MSG_EOR;
2199 		if (control != TLS_RECORD_TYPE_DATA)
2200 			break;
2201 	}
2202 
2203 recv_end:
2204 	if (async) {
2205 		int ret;
2206 
2207 		/* Wait for all previously submitted records to be decrypted */
2208 		ret = tls_decrypt_async_wait(ctx);
2209 		__skb_queue_purge(&ctx->async_hold);
2210 
2211 		if (ret) {
2212 			if (err >= 0 || err == -EINPROGRESS)
2213 				err = ret;
2214 			goto end;
2215 		}
2216 
2217 		/* Drain records from the rx_list & copy if required */
2218 		if (is_peek)
2219 			err = process_rx_list(ctx, msg, &control, copied + peeked,
2220 					      decrypted - peeked, is_peek, NULL);
2221 		else
2222 			err = process_rx_list(ctx, msg, &control, 0,
2223 					      async_copy_bytes, is_peek, NULL);
2224 
2225 		/* we could have copied less than we wanted, and possibly nothing */
2226 		decrypted += max(err, 0) - async_copy_bytes;
2227 	}
2228 
2229 	copied += decrypted;
2230 
2231 end:
2232 	tls_rx_reader_unlock(sk, ctx);
2233 	if (psock)
2234 		sk_psock_put(sk, psock);
2235 	return copied ? : err;
2236 }
2237 
tls_sw_splice_read(struct socket * sock,loff_t * ppos,struct pipe_inode_info * pipe,size_t len,unsigned int flags)2238 ssize_t tls_sw_splice_read(struct socket *sock,  loff_t *ppos,
2239 			   struct pipe_inode_info *pipe,
2240 			   size_t len, unsigned int flags)
2241 {
2242 	struct tls_context *tls_ctx = tls_get_ctx(sock->sk);
2243 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
2244 	struct strp_msg *rxm = NULL;
2245 	struct sock *sk = sock->sk;
2246 	struct tls_msg *tlm;
2247 	struct sk_buff *skb;
2248 	ssize_t copied = 0;
2249 	int chunk;
2250 	int err;
2251 
2252 	err = tls_rx_reader_lock(sk, ctx, flags & SPLICE_F_NONBLOCK);
2253 	if (err < 0)
2254 		return err;
2255 
2256 	if (!skb_queue_empty(&ctx->rx_list)) {
2257 		skb = __skb_dequeue(&ctx->rx_list);
2258 	} else {
2259 		struct tls_decrypt_arg darg;
2260 
2261 		err = tls_rx_rec_wait(sk, NULL, flags & SPLICE_F_NONBLOCK,
2262 				      true);
2263 		if (err <= 0)
2264 			goto splice_read_end;
2265 
2266 		memset(&darg.inargs, 0, sizeof(darg.inargs));
2267 
2268 		err = tls_rx_one_record(sk, NULL, &darg);
2269 		if (err < 0) {
2270 			tls_err_abort(sk, -EBADMSG);
2271 			goto splice_read_end;
2272 		}
2273 
2274 		tls_rx_rec_done(ctx);
2275 		skb = darg.skb;
2276 	}
2277 
2278 	rxm = strp_msg(skb);
2279 	tlm = tls_msg(skb);
2280 
2281 	/* splice does not support reading control messages */
2282 	if (tlm->control != TLS_RECORD_TYPE_DATA) {
2283 		err = -EINVAL;
2284 		goto splice_requeue;
2285 	}
2286 
2287 	chunk = min_t(unsigned int, rxm->full_len, len);
2288 	copied = skb_splice_bits(skb, sk, rxm->offset, pipe, chunk, flags);
2289 	if (copied < 0)
2290 		goto splice_requeue;
2291 
2292 	if (chunk < rxm->full_len) {
2293 		rxm->offset += len;
2294 		rxm->full_len -= len;
2295 		goto splice_requeue;
2296 	}
2297 
2298 	consume_skb(skb);
2299 
2300 splice_read_end:
2301 	tls_rx_reader_unlock(sk, ctx);
2302 	return copied ? : err;
2303 
2304 splice_requeue:
2305 	__skb_queue_head(&ctx->rx_list, skb);
2306 	goto splice_read_end;
2307 }
2308 
tls_sw_read_sock(struct sock * sk,read_descriptor_t * desc,sk_read_actor_t read_actor)2309 int tls_sw_read_sock(struct sock *sk, read_descriptor_t *desc,
2310 		     sk_read_actor_t read_actor)
2311 {
2312 	struct tls_context *tls_ctx = tls_get_ctx(sk);
2313 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
2314 	struct tls_prot_info *prot = &tls_ctx->prot_info;
2315 	struct strp_msg *rxm = NULL;
2316 	struct sk_buff *skb = NULL;
2317 	struct sk_psock *psock;
2318 	size_t flushed_at = 0;
2319 	bool released = true;
2320 	struct tls_msg *tlm;
2321 	ssize_t copied = 0;
2322 	ssize_t decrypted;
2323 	int err, used;
2324 
2325 	psock = sk_psock_get(sk);
2326 	if (psock) {
2327 		sk_psock_put(sk, psock);
2328 		return -EINVAL;
2329 	}
2330 	err = tls_rx_reader_acquire(sk, ctx, true);
2331 	if (err < 0)
2332 		return err;
2333 
2334 	/* If crypto failed the connection is broken */
2335 	err = ctx->async_wait.err;
2336 	if (err)
2337 		goto read_sock_end;
2338 
2339 	decrypted = 0;
2340 	do {
2341 		if (!skb_queue_empty(&ctx->rx_list)) {
2342 			skb = __skb_dequeue(&ctx->rx_list);
2343 			rxm = strp_msg(skb);
2344 			tlm = tls_msg(skb);
2345 		} else {
2346 			struct tls_decrypt_arg darg;
2347 
2348 			err = tls_rx_rec_wait(sk, NULL, true, released);
2349 			if (err <= 0)
2350 				goto read_sock_end;
2351 
2352 			memset(&darg.inargs, 0, sizeof(darg.inargs));
2353 
2354 			err = tls_rx_one_record(sk, NULL, &darg);
2355 			if (err < 0) {
2356 				tls_err_abort(sk, -EBADMSG);
2357 				goto read_sock_end;
2358 			}
2359 
2360 			released = tls_read_flush_backlog(sk, prot, INT_MAX,
2361 							  0, decrypted,
2362 							  &flushed_at);
2363 			skb = darg.skb;
2364 			rxm = strp_msg(skb);
2365 			tlm = tls_msg(skb);
2366 			decrypted += rxm->full_len;
2367 
2368 			tls_rx_rec_done(ctx);
2369 		}
2370 
2371 		/* read_sock does not support reading control messages */
2372 		if (tlm->control != TLS_RECORD_TYPE_DATA) {
2373 			err = -EINVAL;
2374 			goto read_sock_requeue;
2375 		}
2376 
2377 		used = read_actor(desc, skb, rxm->offset, rxm->full_len);
2378 		if (used <= 0) {
2379 			if (!copied)
2380 				err = used;
2381 			goto read_sock_requeue;
2382 		}
2383 		copied += used;
2384 		if (used < rxm->full_len) {
2385 			rxm->offset += used;
2386 			rxm->full_len -= used;
2387 			if (!desc->count)
2388 				goto read_sock_requeue;
2389 		} else {
2390 			consume_skb(skb);
2391 			if (!desc->count)
2392 				skb = NULL;
2393 		}
2394 	} while (skb);
2395 
2396 read_sock_end:
2397 	tls_rx_reader_release(sk, ctx);
2398 	return copied ? : err;
2399 
2400 read_sock_requeue:
2401 	__skb_queue_head(&ctx->rx_list, skb);
2402 	goto read_sock_end;
2403 }
2404 
tls_sw_sock_is_readable(struct sock * sk)2405 bool tls_sw_sock_is_readable(struct sock *sk)
2406 {
2407 	struct tls_context *tls_ctx = tls_get_ctx(sk);
2408 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
2409 	bool ingress_empty = true;
2410 	struct sk_psock *psock;
2411 
2412 	rcu_read_lock();
2413 	psock = sk_psock(sk);
2414 	if (psock)
2415 		ingress_empty = list_empty(&psock->ingress_msg);
2416 	rcu_read_unlock();
2417 
2418 	return !ingress_empty || tls_strp_msg_ready(ctx) ||
2419 		!skb_queue_empty(&ctx->rx_list);
2420 }
2421 
tls_rx_msg_size(struct tls_strparser * strp,struct sk_buff * skb)2422 int tls_rx_msg_size(struct tls_strparser *strp, struct sk_buff *skb)
2423 {
2424 	struct tls_context *tls_ctx = tls_get_ctx(strp->sk);
2425 	struct tls_prot_info *prot = &tls_ctx->prot_info;
2426 	char header[TLS_HEADER_SIZE + TLS_MAX_IV_SIZE];
2427 	size_t cipher_overhead;
2428 	size_t data_len = 0;
2429 	int ret;
2430 
2431 	/* Verify that we have a full TLS header, or wait for more data */
2432 	if (strp->stm.offset + prot->prepend_size > skb->len)
2433 		return 0;
2434 
2435 	/* Sanity-check size of on-stack buffer. */
2436 	if (WARN_ON(prot->prepend_size > sizeof(header))) {
2437 		ret = -EINVAL;
2438 		goto read_failure;
2439 	}
2440 
2441 	/* Linearize header to local buffer */
2442 	ret = skb_copy_bits(skb, strp->stm.offset, header, prot->prepend_size);
2443 	if (ret < 0)
2444 		goto read_failure;
2445 
2446 	strp->mark = header[0];
2447 
2448 	data_len = ((header[4] & 0xFF) | (header[3] << 8));
2449 
2450 	cipher_overhead = prot->tag_size;
2451 	if (prot->version != TLS_1_3_VERSION &&
2452 	    prot->cipher_type != TLS_CIPHER_CHACHA20_POLY1305)
2453 		cipher_overhead += prot->iv_size;
2454 
2455 	if (data_len > TLS_MAX_PAYLOAD_SIZE + cipher_overhead +
2456 	    prot->tail_size) {
2457 		ret = -EMSGSIZE;
2458 		goto read_failure;
2459 	}
2460 	if (data_len < cipher_overhead) {
2461 		ret = -EBADMSG;
2462 		goto read_failure;
2463 	}
2464 
2465 	/* Note that both TLS1.3 and TLS1.2 use TLS_1_2 version here */
2466 	if (header[1] != TLS_1_2_VERSION_MINOR ||
2467 	    header[2] != TLS_1_2_VERSION_MAJOR) {
2468 		ret = -EINVAL;
2469 		goto read_failure;
2470 	}
2471 
2472 	tls_device_rx_resync_new_rec(strp->sk, data_len + TLS_HEADER_SIZE,
2473 				     TCP_SKB_CB(skb)->seq + strp->stm.offset);
2474 	return data_len + TLS_HEADER_SIZE;
2475 
2476 read_failure:
2477 	tls_err_abort(strp->sk, ret);
2478 
2479 	return ret;
2480 }
2481 
tls_rx_msg_ready(struct tls_strparser * strp)2482 void tls_rx_msg_ready(struct tls_strparser *strp)
2483 {
2484 	struct tls_sw_context_rx *ctx;
2485 
2486 	ctx = container_of(strp, struct tls_sw_context_rx, strp);
2487 	ctx->saved_data_ready(strp->sk);
2488 }
2489 
tls_data_ready(struct sock * sk)2490 static void tls_data_ready(struct sock *sk)
2491 {
2492 	struct tls_context *tls_ctx = tls_get_ctx(sk);
2493 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
2494 	struct sk_psock *psock;
2495 	gfp_t alloc_save;
2496 
2497 	trace_sk_data_ready(sk);
2498 
2499 	alloc_save = sk->sk_allocation;
2500 	sk->sk_allocation = GFP_ATOMIC;
2501 	tls_strp_data_ready(&ctx->strp);
2502 	sk->sk_allocation = alloc_save;
2503 
2504 	psock = sk_psock_get(sk);
2505 	if (psock) {
2506 		if (!list_empty(&psock->ingress_msg))
2507 			ctx->saved_data_ready(sk);
2508 		sk_psock_put(sk, psock);
2509 	}
2510 }
2511 
tls_sw_cancel_work_tx(struct tls_context * tls_ctx)2512 void tls_sw_cancel_work_tx(struct tls_context *tls_ctx)
2513 {
2514 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
2515 
2516 	set_bit(BIT_TX_CLOSING, &ctx->tx_bitmask);
2517 	set_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask);
2518 	cancel_delayed_work_sync(&ctx->tx_work.work);
2519 }
2520 
tls_sw_release_resources_tx(struct sock * sk)2521 void tls_sw_release_resources_tx(struct sock *sk)
2522 {
2523 	struct tls_context *tls_ctx = tls_get_ctx(sk);
2524 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
2525 	struct tls_rec *rec, *tmp;
2526 
2527 	/* Wait for any pending async encryptions to complete */
2528 	tls_encrypt_async_wait(ctx);
2529 
2530 	tls_tx_records(sk, -1);
2531 
2532 	/* Free up un-sent records in tx_list. First, free
2533 	 * the partially sent record if any at head of tx_list.
2534 	 */
2535 	if (tls_ctx->partially_sent_record) {
2536 		tls_free_partial_record(sk, tls_ctx);
2537 		rec = list_first_entry(&ctx->tx_list,
2538 				       struct tls_rec, list);
2539 		list_del(&rec->list);
2540 		sk_msg_free(sk, &rec->msg_plaintext);
2541 		kfree(rec);
2542 	}
2543 
2544 	list_for_each_entry_safe(rec, tmp, &ctx->tx_list, list) {
2545 		list_del(&rec->list);
2546 		sk_msg_free(sk, &rec->msg_encrypted);
2547 		sk_msg_free(sk, &rec->msg_plaintext);
2548 		kfree(rec);
2549 	}
2550 
2551 	crypto_free_aead(ctx->aead_send);
2552 	tls_free_open_rec(sk);
2553 }
2554 
tls_sw_free_ctx_tx(struct tls_context * tls_ctx)2555 void tls_sw_free_ctx_tx(struct tls_context *tls_ctx)
2556 {
2557 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
2558 
2559 	kfree(ctx);
2560 }
2561 
tls_sw_release_resources_rx(struct sock * sk)2562 void tls_sw_release_resources_rx(struct sock *sk)
2563 {
2564 	struct tls_context *tls_ctx = tls_get_ctx(sk);
2565 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
2566 
2567 	if (ctx->aead_recv) {
2568 		__skb_queue_purge(&ctx->rx_list);
2569 		crypto_free_aead(ctx->aead_recv);
2570 		tls_strp_stop(&ctx->strp);
2571 		/* If tls_sw_strparser_arm() was not called (cleanup paths)
2572 		 * we still want to tls_strp_stop(), but sk->sk_data_ready was
2573 		 * never swapped.
2574 		 */
2575 		if (ctx->saved_data_ready) {
2576 			write_lock_bh(&sk->sk_callback_lock);
2577 			sk->sk_data_ready = ctx->saved_data_ready;
2578 			write_unlock_bh(&sk->sk_callback_lock);
2579 		}
2580 	}
2581 }
2582 
tls_sw_strparser_done(struct tls_context * tls_ctx)2583 void tls_sw_strparser_done(struct tls_context *tls_ctx)
2584 {
2585 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
2586 
2587 	tls_strp_done(&ctx->strp);
2588 }
2589 
tls_sw_free_ctx_rx(struct tls_context * tls_ctx)2590 void tls_sw_free_ctx_rx(struct tls_context *tls_ctx)
2591 {
2592 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
2593 
2594 	kfree(ctx);
2595 }
2596 
tls_sw_free_resources_rx(struct sock * sk)2597 void tls_sw_free_resources_rx(struct sock *sk)
2598 {
2599 	struct tls_context *tls_ctx = tls_get_ctx(sk);
2600 
2601 	tls_sw_release_resources_rx(sk);
2602 	tls_sw_free_ctx_rx(tls_ctx);
2603 }
2604 
2605 /* The work handler to transmitt the encrypted records in tx_list */
tx_work_handler(struct work_struct * work)2606 static void tx_work_handler(struct work_struct *work)
2607 {
2608 	struct delayed_work *delayed_work = to_delayed_work(work);
2609 	struct tx_work *tx_work = container_of(delayed_work,
2610 					       struct tx_work, work);
2611 	struct sock *sk = tx_work->sk;
2612 	struct tls_context *tls_ctx = tls_get_ctx(sk);
2613 	struct tls_sw_context_tx *ctx;
2614 
2615 	if (unlikely(!tls_ctx))
2616 		return;
2617 
2618 	ctx = tls_sw_ctx_tx(tls_ctx);
2619 	if (test_bit(BIT_TX_CLOSING, &ctx->tx_bitmask))
2620 		return;
2621 
2622 	if (!test_and_clear_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask))
2623 		return;
2624 
2625 	if (mutex_trylock(&tls_ctx->tx_lock)) {
2626 		lock_sock(sk);
2627 		tls_tx_records(sk, -1);
2628 		release_sock(sk);
2629 		mutex_unlock(&tls_ctx->tx_lock);
2630 	} else if (!test_and_set_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask)) {
2631 		/* Someone is holding the tx_lock, they will likely run Tx
2632 		 * and cancel the work on their way out of the lock section.
2633 		 * Schedule a long delay just in case.
2634 		 */
2635 		schedule_delayed_work(&ctx->tx_work.work, msecs_to_jiffies(10));
2636 	}
2637 }
2638 
tls_is_tx_ready(struct tls_sw_context_tx * ctx)2639 static bool tls_is_tx_ready(struct tls_sw_context_tx *ctx)
2640 {
2641 	struct tls_rec *rec;
2642 
2643 	rec = list_first_entry_or_null(&ctx->tx_list, struct tls_rec, list);
2644 	if (!rec)
2645 		return false;
2646 
2647 	return READ_ONCE(rec->tx_ready);
2648 }
2649 
tls_sw_write_space(struct sock * sk,struct tls_context * ctx)2650 void tls_sw_write_space(struct sock *sk, struct tls_context *ctx)
2651 {
2652 	struct tls_sw_context_tx *tx_ctx = tls_sw_ctx_tx(ctx);
2653 
2654 	/* Schedule the transmission if tx list is ready */
2655 	if (tls_is_tx_ready(tx_ctx) &&
2656 	    !test_and_set_bit(BIT_TX_SCHEDULED, &tx_ctx->tx_bitmask))
2657 		schedule_delayed_work(&tx_ctx->tx_work.work, 0);
2658 }
2659 
tls_sw_strparser_arm(struct sock * sk,struct tls_context * tls_ctx)2660 void tls_sw_strparser_arm(struct sock *sk, struct tls_context *tls_ctx)
2661 {
2662 	struct tls_sw_context_rx *rx_ctx = tls_sw_ctx_rx(tls_ctx);
2663 
2664 	write_lock_bh(&sk->sk_callback_lock);
2665 	rx_ctx->saved_data_ready = sk->sk_data_ready;
2666 	sk->sk_data_ready = tls_data_ready;
2667 	write_unlock_bh(&sk->sk_callback_lock);
2668 }
2669 
tls_update_rx_zc_capable(struct tls_context * tls_ctx)2670 void tls_update_rx_zc_capable(struct tls_context *tls_ctx)
2671 {
2672 	struct tls_sw_context_rx *rx_ctx = tls_sw_ctx_rx(tls_ctx);
2673 
2674 	rx_ctx->zc_capable = tls_ctx->rx_no_pad ||
2675 		tls_ctx->prot_info.version != TLS_1_3_VERSION;
2676 }
2677 
init_ctx_tx(struct tls_context * ctx,struct sock * sk)2678 static struct tls_sw_context_tx *init_ctx_tx(struct tls_context *ctx, struct sock *sk)
2679 {
2680 	struct tls_sw_context_tx *sw_ctx_tx;
2681 
2682 	if (!ctx->priv_ctx_tx) {
2683 		sw_ctx_tx = kzalloc(sizeof(*sw_ctx_tx), GFP_KERNEL);
2684 		if (!sw_ctx_tx)
2685 			return NULL;
2686 	} else {
2687 		sw_ctx_tx = ctx->priv_ctx_tx;
2688 	}
2689 
2690 	crypto_init_wait(&sw_ctx_tx->async_wait);
2691 	atomic_set(&sw_ctx_tx->encrypt_pending, 1);
2692 	INIT_LIST_HEAD(&sw_ctx_tx->tx_list);
2693 	INIT_DELAYED_WORK(&sw_ctx_tx->tx_work.work, tx_work_handler);
2694 	sw_ctx_tx->tx_work.sk = sk;
2695 
2696 	return sw_ctx_tx;
2697 }
2698 
init_ctx_rx(struct tls_context * ctx)2699 static struct tls_sw_context_rx *init_ctx_rx(struct tls_context *ctx)
2700 {
2701 	struct tls_sw_context_rx *sw_ctx_rx;
2702 
2703 	if (!ctx->priv_ctx_rx) {
2704 		sw_ctx_rx = kzalloc(sizeof(*sw_ctx_rx), GFP_KERNEL);
2705 		if (!sw_ctx_rx)
2706 			return NULL;
2707 	} else {
2708 		sw_ctx_rx = ctx->priv_ctx_rx;
2709 	}
2710 
2711 	crypto_init_wait(&sw_ctx_rx->async_wait);
2712 	atomic_set(&sw_ctx_rx->decrypt_pending, 1);
2713 	init_waitqueue_head(&sw_ctx_rx->wq);
2714 	skb_queue_head_init(&sw_ctx_rx->rx_list);
2715 	skb_queue_head_init(&sw_ctx_rx->async_hold);
2716 
2717 	return sw_ctx_rx;
2718 }
2719 
init_prot_info(struct tls_prot_info * prot,const struct tls_crypto_info * crypto_info,const struct tls_cipher_desc * cipher_desc)2720 int init_prot_info(struct tls_prot_info *prot,
2721 		   const struct tls_crypto_info *crypto_info,
2722 		   const struct tls_cipher_desc *cipher_desc)
2723 {
2724 	u16 nonce_size = cipher_desc->nonce;
2725 
2726 	if (crypto_info->version == TLS_1_3_VERSION) {
2727 		nonce_size = 0;
2728 		prot->aad_size = TLS_HEADER_SIZE;
2729 		prot->tail_size = 1;
2730 	} else {
2731 		prot->aad_size = TLS_AAD_SPACE_SIZE;
2732 		prot->tail_size = 0;
2733 	}
2734 
2735 	/* Sanity-check the sizes for stack allocations. */
2736 	if (nonce_size > TLS_MAX_IV_SIZE || prot->aad_size > TLS_MAX_AAD_SIZE)
2737 		return -EINVAL;
2738 
2739 	prot->version = crypto_info->version;
2740 	prot->cipher_type = crypto_info->cipher_type;
2741 	prot->prepend_size = TLS_HEADER_SIZE + nonce_size;
2742 	prot->tag_size = cipher_desc->tag;
2743 	prot->overhead_size = prot->prepend_size + prot->tag_size + prot->tail_size;
2744 	prot->iv_size = cipher_desc->iv;
2745 	prot->salt_size = cipher_desc->salt;
2746 	prot->rec_seq_size = cipher_desc->rec_seq;
2747 
2748 	return 0;
2749 }
2750 
tls_finish_key_update(struct sock * sk,struct tls_context * tls_ctx)2751 static void tls_finish_key_update(struct sock *sk, struct tls_context *tls_ctx)
2752 {
2753 	struct tls_sw_context_rx *ctx = tls_ctx->priv_ctx_rx;
2754 
2755 	WRITE_ONCE(ctx->key_update_pending, false);
2756 	/* wake-up pre-existing poll() */
2757 	ctx->saved_data_ready(sk);
2758 }
2759 
tls_set_sw_offload(struct sock * sk,int tx,struct tls_crypto_info * new_crypto_info)2760 int tls_set_sw_offload(struct sock *sk, int tx,
2761 		       struct tls_crypto_info *new_crypto_info)
2762 {
2763 	struct tls_crypto_info *crypto_info, *src_crypto_info;
2764 	struct tls_sw_context_tx *sw_ctx_tx = NULL;
2765 	struct tls_sw_context_rx *sw_ctx_rx = NULL;
2766 	const struct tls_cipher_desc *cipher_desc;
2767 	char *iv, *rec_seq, *key, *salt;
2768 	struct cipher_context *cctx;
2769 	struct tls_prot_info *prot;
2770 	struct crypto_aead **aead;
2771 	struct tls_context *ctx;
2772 	struct crypto_tfm *tfm;
2773 	int rc = 0;
2774 
2775 	ctx = tls_get_ctx(sk);
2776 	prot = &ctx->prot_info;
2777 
2778 	/* new_crypto_info != NULL means rekey */
2779 	if (!new_crypto_info) {
2780 		if (tx) {
2781 			ctx->priv_ctx_tx = init_ctx_tx(ctx, sk);
2782 			if (!ctx->priv_ctx_tx)
2783 				return -ENOMEM;
2784 		} else {
2785 			ctx->priv_ctx_rx = init_ctx_rx(ctx);
2786 			if (!ctx->priv_ctx_rx)
2787 				return -ENOMEM;
2788 		}
2789 	}
2790 
2791 	if (tx) {
2792 		sw_ctx_tx = ctx->priv_ctx_tx;
2793 		crypto_info = &ctx->crypto_send.info;
2794 		cctx = &ctx->tx;
2795 		aead = &sw_ctx_tx->aead_send;
2796 	} else {
2797 		sw_ctx_rx = ctx->priv_ctx_rx;
2798 		crypto_info = &ctx->crypto_recv.info;
2799 		cctx = &ctx->rx;
2800 		aead = &sw_ctx_rx->aead_recv;
2801 	}
2802 
2803 	src_crypto_info = new_crypto_info ?: crypto_info;
2804 
2805 	cipher_desc = get_cipher_desc(src_crypto_info->cipher_type);
2806 	if (!cipher_desc) {
2807 		rc = -EINVAL;
2808 		goto free_priv;
2809 	}
2810 
2811 	rc = init_prot_info(prot, src_crypto_info, cipher_desc);
2812 	if (rc)
2813 		goto free_priv;
2814 
2815 	iv = crypto_info_iv(src_crypto_info, cipher_desc);
2816 	key = crypto_info_key(src_crypto_info, cipher_desc);
2817 	salt = crypto_info_salt(src_crypto_info, cipher_desc);
2818 	rec_seq = crypto_info_rec_seq(src_crypto_info, cipher_desc);
2819 
2820 	if (!*aead) {
2821 		*aead = crypto_alloc_aead(cipher_desc->cipher_name, 0, 0);
2822 		if (IS_ERR(*aead)) {
2823 			rc = PTR_ERR(*aead);
2824 			*aead = NULL;
2825 			goto free_priv;
2826 		}
2827 	}
2828 
2829 	ctx->push_pending_record = tls_sw_push_pending_record;
2830 
2831 	/* setkey is the last operation that could fail during a
2832 	 * rekey. if it succeeds, we can start modifying the
2833 	 * context.
2834 	 */
2835 	rc = crypto_aead_setkey(*aead, key, cipher_desc->key);
2836 	if (rc) {
2837 		if (new_crypto_info)
2838 			goto out;
2839 		else
2840 			goto free_aead;
2841 	}
2842 
2843 	if (!new_crypto_info) {
2844 		rc = crypto_aead_setauthsize(*aead, prot->tag_size);
2845 		if (rc)
2846 			goto free_aead;
2847 	}
2848 
2849 	if (!tx && !new_crypto_info) {
2850 		tfm = crypto_aead_tfm(sw_ctx_rx->aead_recv);
2851 
2852 		tls_update_rx_zc_capable(ctx);
2853 		sw_ctx_rx->async_capable =
2854 			src_crypto_info->version != TLS_1_3_VERSION &&
2855 			!!(tfm->__crt_alg->cra_flags & CRYPTO_ALG_ASYNC);
2856 
2857 		rc = tls_strp_init(&sw_ctx_rx->strp, sk);
2858 		if (rc)
2859 			goto free_aead;
2860 	}
2861 
2862 	memcpy(cctx->iv, salt, cipher_desc->salt);
2863 	memcpy(cctx->iv + cipher_desc->salt, iv, cipher_desc->iv);
2864 	memcpy(cctx->rec_seq, rec_seq, cipher_desc->rec_seq);
2865 
2866 	if (new_crypto_info) {
2867 		unsafe_memcpy(crypto_info, new_crypto_info,
2868 			      cipher_desc->crypto_info,
2869 			      /* size was checked in do_tls_setsockopt_conf */);
2870 		memzero_explicit(new_crypto_info, cipher_desc->crypto_info);
2871 		if (!tx)
2872 			tls_finish_key_update(sk, ctx);
2873 	}
2874 
2875 	goto out;
2876 
2877 free_aead:
2878 	crypto_free_aead(*aead);
2879 	*aead = NULL;
2880 free_priv:
2881 	if (!new_crypto_info) {
2882 		if (tx) {
2883 			kfree(ctx->priv_ctx_tx);
2884 			ctx->priv_ctx_tx = NULL;
2885 		} else {
2886 			kfree(ctx->priv_ctx_rx);
2887 			ctx->priv_ctx_rx = NULL;
2888 		}
2889 	}
2890 out:
2891 	return rc;
2892 }
2893