xref: /linux/net/tls/tls_sw.c (revision 4d66c56f7efe122d09d06cd3ebfa52a43d51a9cb)
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/sched/signal.h>
39 #include <linux/module.h>
40 #include <crypto/aead.h>
41 
42 #include <net/strparser.h>
43 #include <net/tls.h>
44 
45 static int __skb_nsg(struct sk_buff *skb, int offset, int len,
46                      unsigned int recursion_level)
47 {
48         int start = skb_headlen(skb);
49         int i, chunk = start - offset;
50         struct sk_buff *frag_iter;
51         int elt = 0;
52 
53         if (unlikely(recursion_level >= 24))
54                 return -EMSGSIZE;
55 
56         if (chunk > 0) {
57                 if (chunk > len)
58                         chunk = len;
59                 elt++;
60                 len -= chunk;
61                 if (len == 0)
62                         return elt;
63                 offset += chunk;
64         }
65 
66         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
67                 int end;
68 
69                 WARN_ON(start > offset + len);
70 
71                 end = start + skb_frag_size(&skb_shinfo(skb)->frags[i]);
72                 chunk = end - offset;
73                 if (chunk > 0) {
74                         if (chunk > len)
75                                 chunk = len;
76                         elt++;
77                         len -= chunk;
78                         if (len == 0)
79                                 return elt;
80                         offset += chunk;
81                 }
82                 start = end;
83         }
84 
85         if (unlikely(skb_has_frag_list(skb))) {
86                 skb_walk_frags(skb, frag_iter) {
87                         int end, ret;
88 
89                         WARN_ON(start > offset + len);
90 
91                         end = start + frag_iter->len;
92                         chunk = end - offset;
93                         if (chunk > 0) {
94                                 if (chunk > len)
95                                         chunk = len;
96                                 ret = __skb_nsg(frag_iter, offset - start, chunk,
97                                                 recursion_level + 1);
98                                 if (unlikely(ret < 0))
99                                         return ret;
100                                 elt += ret;
101                                 len -= chunk;
102                                 if (len == 0)
103                                         return elt;
104                                 offset += chunk;
105                         }
106                         start = end;
107                 }
108         }
109         BUG_ON(len);
110         return elt;
111 }
112 
113 /* Return the number of scatterlist elements required to completely map the
114  * skb, or -EMSGSIZE if the recursion depth is exceeded.
115  */
116 static int skb_nsg(struct sk_buff *skb, int offset, int len)
117 {
118         return __skb_nsg(skb, offset, len, 0);
119 }
120 
121 static int padding_length(struct tls_sw_context_rx *ctx,
122 			  struct tls_prot_info *prot, struct sk_buff *skb)
123 {
124 	struct strp_msg *rxm = strp_msg(skb);
125 	int sub = 0;
126 
127 	/* Determine zero-padding length */
128 	if (prot->version == TLS_1_3_VERSION) {
129 		char content_type = 0;
130 		int err;
131 		int back = 17;
132 
133 		while (content_type == 0) {
134 			if (back > rxm->full_len - prot->prepend_size)
135 				return -EBADMSG;
136 			err = skb_copy_bits(skb,
137 					    rxm->offset + rxm->full_len - back,
138 					    &content_type, 1);
139 			if (err)
140 				return err;
141 			if (content_type)
142 				break;
143 			sub++;
144 			back++;
145 		}
146 		ctx->control = content_type;
147 	}
148 	return sub;
149 }
150 
151 static void tls_decrypt_done(struct crypto_async_request *req, int err)
152 {
153 	struct aead_request *aead_req = (struct aead_request *)req;
154 	struct scatterlist *sgout = aead_req->dst;
155 	struct scatterlist *sgin = aead_req->src;
156 	struct tls_sw_context_rx *ctx;
157 	struct tls_context *tls_ctx;
158 	struct tls_prot_info *prot;
159 	struct scatterlist *sg;
160 	struct sk_buff *skb;
161 	unsigned int pages;
162 	int pending;
163 
164 	skb = (struct sk_buff *)req->data;
165 	tls_ctx = tls_get_ctx(skb->sk);
166 	ctx = tls_sw_ctx_rx(tls_ctx);
167 	prot = &tls_ctx->prot_info;
168 
169 	/* Propagate if there was an err */
170 	if (err) {
171 		if (err == -EBADMSG)
172 			TLS_INC_STATS(sock_net(skb->sk),
173 				      LINUX_MIB_TLSDECRYPTERROR);
174 		ctx->async_wait.err = err;
175 		tls_err_abort(skb->sk, err);
176 	} else {
177 		struct strp_msg *rxm = strp_msg(skb);
178 		int pad;
179 
180 		pad = padding_length(ctx, prot, skb);
181 		if (pad < 0) {
182 			ctx->async_wait.err = pad;
183 			tls_err_abort(skb->sk, pad);
184 		} else {
185 			rxm->full_len -= pad;
186 			rxm->offset += prot->prepend_size;
187 			rxm->full_len -= prot->overhead_size;
188 		}
189 	}
190 
191 	/* After using skb->sk to propagate sk through crypto async callback
192 	 * we need to NULL it again.
193 	 */
194 	skb->sk = NULL;
195 
196 
197 	/* Free the destination pages if skb was not decrypted inplace */
198 	if (sgout != sgin) {
199 		/* Skip the first S/G entry as it points to AAD */
200 		for_each_sg(sg_next(sgout), sg, UINT_MAX, pages) {
201 			if (!sg)
202 				break;
203 			put_page(sg_page(sg));
204 		}
205 	}
206 
207 	kfree(aead_req);
208 
209 	pending = atomic_dec_return(&ctx->decrypt_pending);
210 
211 	if (!pending && READ_ONCE(ctx->async_notify))
212 		complete(&ctx->async_wait.completion);
213 }
214 
215 static int tls_do_decryption(struct sock *sk,
216 			     struct sk_buff *skb,
217 			     struct scatterlist *sgin,
218 			     struct scatterlist *sgout,
219 			     char *iv_recv,
220 			     size_t data_len,
221 			     struct aead_request *aead_req,
222 			     bool async)
223 {
224 	struct tls_context *tls_ctx = tls_get_ctx(sk);
225 	struct tls_prot_info *prot = &tls_ctx->prot_info;
226 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
227 	int ret;
228 
229 	aead_request_set_tfm(aead_req, ctx->aead_recv);
230 	aead_request_set_ad(aead_req, prot->aad_size);
231 	aead_request_set_crypt(aead_req, sgin, sgout,
232 			       data_len + prot->tag_size,
233 			       (u8 *)iv_recv);
234 
235 	if (async) {
236 		/* Using skb->sk to push sk through to crypto async callback
237 		 * handler. This allows propagating errors up to the socket
238 		 * if needed. It _must_ be cleared in the async handler
239 		 * before consume_skb is called. We _know_ skb->sk is NULL
240 		 * because it is a clone from strparser.
241 		 */
242 		skb->sk = sk;
243 		aead_request_set_callback(aead_req,
244 					  CRYPTO_TFM_REQ_MAY_BACKLOG,
245 					  tls_decrypt_done, skb);
246 		atomic_inc(&ctx->decrypt_pending);
247 	} else {
248 		aead_request_set_callback(aead_req,
249 					  CRYPTO_TFM_REQ_MAY_BACKLOG,
250 					  crypto_req_done, &ctx->async_wait);
251 	}
252 
253 	ret = crypto_aead_decrypt(aead_req);
254 	if (ret == -EINPROGRESS) {
255 		if (async)
256 			return ret;
257 
258 		ret = crypto_wait_req(ret, &ctx->async_wait);
259 	} else if (ret == -EBADMSG) {
260 		TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSDECRYPTERROR);
261 	}
262 
263 	if (async)
264 		atomic_dec(&ctx->decrypt_pending);
265 
266 	return ret;
267 }
268 
269 static void tls_trim_both_msgs(struct sock *sk, int target_size)
270 {
271 	struct tls_context *tls_ctx = tls_get_ctx(sk);
272 	struct tls_prot_info *prot = &tls_ctx->prot_info;
273 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
274 	struct tls_rec *rec = ctx->open_rec;
275 
276 	sk_msg_trim(sk, &rec->msg_plaintext, target_size);
277 	if (target_size > 0)
278 		target_size += prot->overhead_size;
279 	sk_msg_trim(sk, &rec->msg_encrypted, target_size);
280 }
281 
282 static int tls_alloc_encrypted_msg(struct sock *sk, int len)
283 {
284 	struct tls_context *tls_ctx = tls_get_ctx(sk);
285 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
286 	struct tls_rec *rec = ctx->open_rec;
287 	struct sk_msg *msg_en = &rec->msg_encrypted;
288 
289 	return sk_msg_alloc(sk, msg_en, len, 0);
290 }
291 
292 static int tls_clone_plaintext_msg(struct sock *sk, int required)
293 {
294 	struct tls_context *tls_ctx = tls_get_ctx(sk);
295 	struct tls_prot_info *prot = &tls_ctx->prot_info;
296 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
297 	struct tls_rec *rec = ctx->open_rec;
298 	struct sk_msg *msg_pl = &rec->msg_plaintext;
299 	struct sk_msg *msg_en = &rec->msg_encrypted;
300 	int skip, len;
301 
302 	/* We add page references worth len bytes from encrypted sg
303 	 * at the end of plaintext sg. It is guaranteed that msg_en
304 	 * has enough required room (ensured by caller).
305 	 */
306 	len = required - msg_pl->sg.size;
307 
308 	/* Skip initial bytes in msg_en's data to be able to use
309 	 * same offset of both plain and encrypted data.
310 	 */
311 	skip = prot->prepend_size + msg_pl->sg.size;
312 
313 	return sk_msg_clone(sk, msg_pl, msg_en, skip, len);
314 }
315 
316 static struct tls_rec *tls_get_rec(struct sock *sk)
317 {
318 	struct tls_context *tls_ctx = tls_get_ctx(sk);
319 	struct tls_prot_info *prot = &tls_ctx->prot_info;
320 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
321 	struct sk_msg *msg_pl, *msg_en;
322 	struct tls_rec *rec;
323 	int mem_size;
324 
325 	mem_size = sizeof(struct tls_rec) + crypto_aead_reqsize(ctx->aead_send);
326 
327 	rec = kzalloc(mem_size, sk->sk_allocation);
328 	if (!rec)
329 		return NULL;
330 
331 	msg_pl = &rec->msg_plaintext;
332 	msg_en = &rec->msg_encrypted;
333 
334 	sk_msg_init(msg_pl);
335 	sk_msg_init(msg_en);
336 
337 	sg_init_table(rec->sg_aead_in, 2);
338 	sg_set_buf(&rec->sg_aead_in[0], rec->aad_space, prot->aad_size);
339 	sg_unmark_end(&rec->sg_aead_in[1]);
340 
341 	sg_init_table(rec->sg_aead_out, 2);
342 	sg_set_buf(&rec->sg_aead_out[0], rec->aad_space, prot->aad_size);
343 	sg_unmark_end(&rec->sg_aead_out[1]);
344 
345 	return rec;
346 }
347 
348 static void tls_free_rec(struct sock *sk, struct tls_rec *rec)
349 {
350 	sk_msg_free(sk, &rec->msg_encrypted);
351 	sk_msg_free(sk, &rec->msg_plaintext);
352 	kfree(rec);
353 }
354 
355 static void tls_free_open_rec(struct sock *sk)
356 {
357 	struct tls_context *tls_ctx = tls_get_ctx(sk);
358 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
359 	struct tls_rec *rec = ctx->open_rec;
360 
361 	if (rec) {
362 		tls_free_rec(sk, rec);
363 		ctx->open_rec = NULL;
364 	}
365 }
366 
367 int tls_tx_records(struct sock *sk, int flags)
368 {
369 	struct tls_context *tls_ctx = tls_get_ctx(sk);
370 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
371 	struct tls_rec *rec, *tmp;
372 	struct sk_msg *msg_en;
373 	int tx_flags, rc = 0;
374 
375 	if (tls_is_partially_sent_record(tls_ctx)) {
376 		rec = list_first_entry(&ctx->tx_list,
377 				       struct tls_rec, list);
378 
379 		if (flags == -1)
380 			tx_flags = rec->tx_flags;
381 		else
382 			tx_flags = flags;
383 
384 		rc = tls_push_partial_record(sk, tls_ctx, tx_flags);
385 		if (rc)
386 			goto tx_err;
387 
388 		/* Full record has been transmitted.
389 		 * Remove the head of tx_list
390 		 */
391 		list_del(&rec->list);
392 		sk_msg_free(sk, &rec->msg_plaintext);
393 		kfree(rec);
394 	}
395 
396 	/* Tx all ready records */
397 	list_for_each_entry_safe(rec, tmp, &ctx->tx_list, list) {
398 		if (READ_ONCE(rec->tx_ready)) {
399 			if (flags == -1)
400 				tx_flags = rec->tx_flags;
401 			else
402 				tx_flags = flags;
403 
404 			msg_en = &rec->msg_encrypted;
405 			rc = tls_push_sg(sk, tls_ctx,
406 					 &msg_en->sg.data[msg_en->sg.curr],
407 					 0, tx_flags);
408 			if (rc)
409 				goto tx_err;
410 
411 			list_del(&rec->list);
412 			sk_msg_free(sk, &rec->msg_plaintext);
413 			kfree(rec);
414 		} else {
415 			break;
416 		}
417 	}
418 
419 tx_err:
420 	if (rc < 0 && rc != -EAGAIN)
421 		tls_err_abort(sk, EBADMSG);
422 
423 	return rc;
424 }
425 
426 static void tls_encrypt_done(struct crypto_async_request *req, int err)
427 {
428 	struct aead_request *aead_req = (struct aead_request *)req;
429 	struct sock *sk = req->data;
430 	struct tls_context *tls_ctx = tls_get_ctx(sk);
431 	struct tls_prot_info *prot = &tls_ctx->prot_info;
432 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
433 	struct scatterlist *sge;
434 	struct sk_msg *msg_en;
435 	struct tls_rec *rec;
436 	bool ready = false;
437 	int pending;
438 
439 	rec = container_of(aead_req, struct tls_rec, aead_req);
440 	msg_en = &rec->msg_encrypted;
441 
442 	sge = sk_msg_elem(msg_en, msg_en->sg.curr);
443 	sge->offset -= prot->prepend_size;
444 	sge->length += prot->prepend_size;
445 
446 	/* Check if error is previously set on socket */
447 	if (err || sk->sk_err) {
448 		rec = NULL;
449 
450 		/* If err is already set on socket, return the same code */
451 		if (sk->sk_err) {
452 			ctx->async_wait.err = sk->sk_err;
453 		} else {
454 			ctx->async_wait.err = err;
455 			tls_err_abort(sk, err);
456 		}
457 	}
458 
459 	if (rec) {
460 		struct tls_rec *first_rec;
461 
462 		/* Mark the record as ready for transmission */
463 		smp_store_mb(rec->tx_ready, true);
464 
465 		/* If received record is at head of tx_list, schedule tx */
466 		first_rec = list_first_entry(&ctx->tx_list,
467 					     struct tls_rec, list);
468 		if (rec == first_rec)
469 			ready = true;
470 	}
471 
472 	pending = atomic_dec_return(&ctx->encrypt_pending);
473 
474 	if (!pending && READ_ONCE(ctx->async_notify))
475 		complete(&ctx->async_wait.completion);
476 
477 	if (!ready)
478 		return;
479 
480 	/* Schedule the transmission */
481 	if (!test_and_set_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask))
482 		schedule_delayed_work(&ctx->tx_work.work, 1);
483 }
484 
485 static int tls_do_encryption(struct sock *sk,
486 			     struct tls_context *tls_ctx,
487 			     struct tls_sw_context_tx *ctx,
488 			     struct aead_request *aead_req,
489 			     size_t data_len, u32 start)
490 {
491 	struct tls_prot_info *prot = &tls_ctx->prot_info;
492 	struct tls_rec *rec = ctx->open_rec;
493 	struct sk_msg *msg_en = &rec->msg_encrypted;
494 	struct scatterlist *sge = sk_msg_elem(msg_en, start);
495 	int rc, iv_offset = 0;
496 
497 	/* For CCM based ciphers, first byte of IV is a constant */
498 	if (prot->cipher_type == TLS_CIPHER_AES_CCM_128) {
499 		rec->iv_data[0] = TLS_AES_CCM_IV_B0_BYTE;
500 		iv_offset = 1;
501 	}
502 
503 	memcpy(&rec->iv_data[iv_offset], tls_ctx->tx.iv,
504 	       prot->iv_size + prot->salt_size);
505 
506 	xor_iv_with_seq(prot->version, rec->iv_data, tls_ctx->tx.rec_seq);
507 
508 	sge->offset += prot->prepend_size;
509 	sge->length -= prot->prepend_size;
510 
511 	msg_en->sg.curr = start;
512 
513 	aead_request_set_tfm(aead_req, ctx->aead_send);
514 	aead_request_set_ad(aead_req, prot->aad_size);
515 	aead_request_set_crypt(aead_req, rec->sg_aead_in,
516 			       rec->sg_aead_out,
517 			       data_len, rec->iv_data);
518 
519 	aead_request_set_callback(aead_req, CRYPTO_TFM_REQ_MAY_BACKLOG,
520 				  tls_encrypt_done, sk);
521 
522 	/* Add the record in tx_list */
523 	list_add_tail((struct list_head *)&rec->list, &ctx->tx_list);
524 	atomic_inc(&ctx->encrypt_pending);
525 
526 	rc = crypto_aead_encrypt(aead_req);
527 	if (!rc || rc != -EINPROGRESS) {
528 		atomic_dec(&ctx->encrypt_pending);
529 		sge->offset -= prot->prepend_size;
530 		sge->length += prot->prepend_size;
531 	}
532 
533 	if (!rc) {
534 		WRITE_ONCE(rec->tx_ready, true);
535 	} else if (rc != -EINPROGRESS) {
536 		list_del(&rec->list);
537 		return rc;
538 	}
539 
540 	/* Unhook the record from context if encryption is not failure */
541 	ctx->open_rec = NULL;
542 	tls_advance_record_sn(sk, prot, &tls_ctx->tx);
543 	return rc;
544 }
545 
546 static int tls_split_open_record(struct sock *sk, struct tls_rec *from,
547 				 struct tls_rec **to, struct sk_msg *msg_opl,
548 				 struct sk_msg *msg_oen, u32 split_point,
549 				 u32 tx_overhead_size, u32 *orig_end)
550 {
551 	u32 i, j, bytes = 0, apply = msg_opl->apply_bytes;
552 	struct scatterlist *sge, *osge, *nsge;
553 	u32 orig_size = msg_opl->sg.size;
554 	struct scatterlist tmp = { };
555 	struct sk_msg *msg_npl;
556 	struct tls_rec *new;
557 	int ret;
558 
559 	new = tls_get_rec(sk);
560 	if (!new)
561 		return -ENOMEM;
562 	ret = sk_msg_alloc(sk, &new->msg_encrypted, msg_opl->sg.size +
563 			   tx_overhead_size, 0);
564 	if (ret < 0) {
565 		tls_free_rec(sk, new);
566 		return ret;
567 	}
568 
569 	*orig_end = msg_opl->sg.end;
570 	i = msg_opl->sg.start;
571 	sge = sk_msg_elem(msg_opl, i);
572 	while (apply && sge->length) {
573 		if (sge->length > apply) {
574 			u32 len = sge->length - apply;
575 
576 			get_page(sg_page(sge));
577 			sg_set_page(&tmp, sg_page(sge), len,
578 				    sge->offset + apply);
579 			sge->length = apply;
580 			bytes += apply;
581 			apply = 0;
582 		} else {
583 			apply -= sge->length;
584 			bytes += sge->length;
585 		}
586 
587 		sk_msg_iter_var_next(i);
588 		if (i == msg_opl->sg.end)
589 			break;
590 		sge = sk_msg_elem(msg_opl, i);
591 	}
592 
593 	msg_opl->sg.end = i;
594 	msg_opl->sg.curr = i;
595 	msg_opl->sg.copybreak = 0;
596 	msg_opl->apply_bytes = 0;
597 	msg_opl->sg.size = bytes;
598 
599 	msg_npl = &new->msg_plaintext;
600 	msg_npl->apply_bytes = apply;
601 	msg_npl->sg.size = orig_size - bytes;
602 
603 	j = msg_npl->sg.start;
604 	nsge = sk_msg_elem(msg_npl, j);
605 	if (tmp.length) {
606 		memcpy(nsge, &tmp, sizeof(*nsge));
607 		sk_msg_iter_var_next(j);
608 		nsge = sk_msg_elem(msg_npl, j);
609 	}
610 
611 	osge = sk_msg_elem(msg_opl, i);
612 	while (osge->length) {
613 		memcpy(nsge, osge, sizeof(*nsge));
614 		sg_unmark_end(nsge);
615 		sk_msg_iter_var_next(i);
616 		sk_msg_iter_var_next(j);
617 		if (i == *orig_end)
618 			break;
619 		osge = sk_msg_elem(msg_opl, i);
620 		nsge = sk_msg_elem(msg_npl, j);
621 	}
622 
623 	msg_npl->sg.end = j;
624 	msg_npl->sg.curr = j;
625 	msg_npl->sg.copybreak = 0;
626 
627 	*to = new;
628 	return 0;
629 }
630 
631 static void tls_merge_open_record(struct sock *sk, struct tls_rec *to,
632 				  struct tls_rec *from, u32 orig_end)
633 {
634 	struct sk_msg *msg_npl = &from->msg_plaintext;
635 	struct sk_msg *msg_opl = &to->msg_plaintext;
636 	struct scatterlist *osge, *nsge;
637 	u32 i, j;
638 
639 	i = msg_opl->sg.end;
640 	sk_msg_iter_var_prev(i);
641 	j = msg_npl->sg.start;
642 
643 	osge = sk_msg_elem(msg_opl, i);
644 	nsge = sk_msg_elem(msg_npl, j);
645 
646 	if (sg_page(osge) == sg_page(nsge) &&
647 	    osge->offset + osge->length == nsge->offset) {
648 		osge->length += nsge->length;
649 		put_page(sg_page(nsge));
650 	}
651 
652 	msg_opl->sg.end = orig_end;
653 	msg_opl->sg.curr = orig_end;
654 	msg_opl->sg.copybreak = 0;
655 	msg_opl->apply_bytes = msg_opl->sg.size + msg_npl->sg.size;
656 	msg_opl->sg.size += msg_npl->sg.size;
657 
658 	sk_msg_free(sk, &to->msg_encrypted);
659 	sk_msg_xfer_full(&to->msg_encrypted, &from->msg_encrypted);
660 
661 	kfree(from);
662 }
663 
664 static int tls_push_record(struct sock *sk, int flags,
665 			   unsigned char record_type)
666 {
667 	struct tls_context *tls_ctx = tls_get_ctx(sk);
668 	struct tls_prot_info *prot = &tls_ctx->prot_info;
669 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
670 	struct tls_rec *rec = ctx->open_rec, *tmp = NULL;
671 	u32 i, split_point, uninitialized_var(orig_end);
672 	struct sk_msg *msg_pl, *msg_en;
673 	struct aead_request *req;
674 	bool split;
675 	int rc;
676 
677 	if (!rec)
678 		return 0;
679 
680 	msg_pl = &rec->msg_plaintext;
681 	msg_en = &rec->msg_encrypted;
682 
683 	split_point = msg_pl->apply_bytes;
684 	split = split_point && split_point < msg_pl->sg.size;
685 	if (split) {
686 		rc = tls_split_open_record(sk, rec, &tmp, msg_pl, msg_en,
687 					   split_point, prot->overhead_size,
688 					   &orig_end);
689 		if (rc < 0)
690 			return rc;
691 		sk_msg_trim(sk, msg_en, msg_pl->sg.size +
692 			    prot->overhead_size);
693 	}
694 
695 	rec->tx_flags = flags;
696 	req = &rec->aead_req;
697 
698 	i = msg_pl->sg.end;
699 	sk_msg_iter_var_prev(i);
700 
701 	rec->content_type = record_type;
702 	if (prot->version == TLS_1_3_VERSION) {
703 		/* Add content type to end of message.  No padding added */
704 		sg_set_buf(&rec->sg_content_type, &rec->content_type, 1);
705 		sg_mark_end(&rec->sg_content_type);
706 		sg_chain(msg_pl->sg.data, msg_pl->sg.end + 1,
707 			 &rec->sg_content_type);
708 	} else {
709 		sg_mark_end(sk_msg_elem(msg_pl, i));
710 	}
711 
712 	i = msg_pl->sg.start;
713 	sg_chain(rec->sg_aead_in, 2, rec->inplace_crypto ?
714 		 &msg_en->sg.data[i] : &msg_pl->sg.data[i]);
715 
716 	i = msg_en->sg.end;
717 	sk_msg_iter_var_prev(i);
718 	sg_mark_end(sk_msg_elem(msg_en, i));
719 
720 	i = msg_en->sg.start;
721 	sg_chain(rec->sg_aead_out, 2, &msg_en->sg.data[i]);
722 
723 	tls_make_aad(rec->aad_space, msg_pl->sg.size + prot->tail_size,
724 		     tls_ctx->tx.rec_seq, prot->rec_seq_size,
725 		     record_type, prot->version);
726 
727 	tls_fill_prepend(tls_ctx,
728 			 page_address(sg_page(&msg_en->sg.data[i])) +
729 			 msg_en->sg.data[i].offset,
730 			 msg_pl->sg.size + prot->tail_size,
731 			 record_type, prot->version);
732 
733 	tls_ctx->pending_open_record_frags = false;
734 
735 	rc = tls_do_encryption(sk, tls_ctx, ctx, req,
736 			       msg_pl->sg.size + prot->tail_size, i);
737 	if (rc < 0) {
738 		if (rc != -EINPROGRESS) {
739 			tls_err_abort(sk, EBADMSG);
740 			if (split) {
741 				tls_ctx->pending_open_record_frags = true;
742 				tls_merge_open_record(sk, rec, tmp, orig_end);
743 			}
744 		}
745 		ctx->async_capable = 1;
746 		return rc;
747 	} else if (split) {
748 		msg_pl = &tmp->msg_plaintext;
749 		msg_en = &tmp->msg_encrypted;
750 		sk_msg_trim(sk, msg_en, msg_pl->sg.size + prot->overhead_size);
751 		tls_ctx->pending_open_record_frags = true;
752 		ctx->open_rec = tmp;
753 	}
754 
755 	return tls_tx_records(sk, flags);
756 }
757 
758 static int bpf_exec_tx_verdict(struct sk_msg *msg, struct sock *sk,
759 			       bool full_record, u8 record_type,
760 			       size_t *copied, int flags)
761 {
762 	struct tls_context *tls_ctx = tls_get_ctx(sk);
763 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
764 	struct sk_msg msg_redir = { };
765 	struct sk_psock *psock;
766 	struct sock *sk_redir;
767 	struct tls_rec *rec;
768 	bool enospc, policy;
769 	int err = 0, send;
770 	u32 delta = 0;
771 
772 	policy = !(flags & MSG_SENDPAGE_NOPOLICY);
773 	psock = sk_psock_get(sk);
774 	if (!psock || !policy)
775 		return tls_push_record(sk, flags, record_type);
776 more_data:
777 	enospc = sk_msg_full(msg);
778 	if (psock->eval == __SK_NONE) {
779 		delta = msg->sg.size;
780 		psock->eval = sk_psock_msg_verdict(sk, psock, msg);
781 		if (delta < msg->sg.size)
782 			delta -= msg->sg.size;
783 		else
784 			delta = 0;
785 	}
786 	if (msg->cork_bytes && msg->cork_bytes > msg->sg.size &&
787 	    !enospc && !full_record) {
788 		err = -ENOSPC;
789 		goto out_err;
790 	}
791 	msg->cork_bytes = 0;
792 	send = msg->sg.size;
793 	if (msg->apply_bytes && msg->apply_bytes < send)
794 		send = msg->apply_bytes;
795 
796 	switch (psock->eval) {
797 	case __SK_PASS:
798 		err = tls_push_record(sk, flags, record_type);
799 		if (err < 0) {
800 			*copied -= sk_msg_free(sk, msg);
801 			tls_free_open_rec(sk);
802 			goto out_err;
803 		}
804 		break;
805 	case __SK_REDIRECT:
806 		sk_redir = psock->sk_redir;
807 		memcpy(&msg_redir, msg, sizeof(*msg));
808 		if (msg->apply_bytes < send)
809 			msg->apply_bytes = 0;
810 		else
811 			msg->apply_bytes -= send;
812 		sk_msg_return_zero(sk, msg, send);
813 		msg->sg.size -= send;
814 		release_sock(sk);
815 		err = tcp_bpf_sendmsg_redir(sk_redir, &msg_redir, send, flags);
816 		lock_sock(sk);
817 		if (err < 0) {
818 			*copied -= sk_msg_free_nocharge(sk, &msg_redir);
819 			msg->sg.size = 0;
820 		}
821 		if (msg->sg.size == 0)
822 			tls_free_open_rec(sk);
823 		break;
824 	case __SK_DROP:
825 	default:
826 		sk_msg_free_partial(sk, msg, send);
827 		if (msg->apply_bytes < send)
828 			msg->apply_bytes = 0;
829 		else
830 			msg->apply_bytes -= send;
831 		if (msg->sg.size == 0)
832 			tls_free_open_rec(sk);
833 		*copied -= (send + delta);
834 		err = -EACCES;
835 	}
836 
837 	if (likely(!err)) {
838 		bool reset_eval = !ctx->open_rec;
839 
840 		rec = ctx->open_rec;
841 		if (rec) {
842 			msg = &rec->msg_plaintext;
843 			if (!msg->apply_bytes)
844 				reset_eval = true;
845 		}
846 		if (reset_eval) {
847 			psock->eval = __SK_NONE;
848 			if (psock->sk_redir) {
849 				sock_put(psock->sk_redir);
850 				psock->sk_redir = NULL;
851 			}
852 		}
853 		if (rec)
854 			goto more_data;
855 	}
856  out_err:
857 	sk_psock_put(sk, psock);
858 	return err;
859 }
860 
861 static int tls_sw_push_pending_record(struct sock *sk, int flags)
862 {
863 	struct tls_context *tls_ctx = tls_get_ctx(sk);
864 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
865 	struct tls_rec *rec = ctx->open_rec;
866 	struct sk_msg *msg_pl;
867 	size_t copied;
868 
869 	if (!rec)
870 		return 0;
871 
872 	msg_pl = &rec->msg_plaintext;
873 	copied = msg_pl->sg.size;
874 	if (!copied)
875 		return 0;
876 
877 	return bpf_exec_tx_verdict(msg_pl, sk, true, TLS_RECORD_TYPE_DATA,
878 				   &copied, flags);
879 }
880 
881 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
882 {
883 	long timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
884 	struct tls_context *tls_ctx = tls_get_ctx(sk);
885 	struct tls_prot_info *prot = &tls_ctx->prot_info;
886 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
887 	bool async_capable = ctx->async_capable;
888 	unsigned char record_type = TLS_RECORD_TYPE_DATA;
889 	bool is_kvec = iov_iter_is_kvec(&msg->msg_iter);
890 	bool eor = !(msg->msg_flags & MSG_MORE);
891 	size_t try_to_copy, copied = 0;
892 	struct sk_msg *msg_pl, *msg_en;
893 	struct tls_rec *rec;
894 	int required_size;
895 	int num_async = 0;
896 	bool full_record;
897 	int record_room;
898 	int num_zc = 0;
899 	int orig_size;
900 	int ret = 0;
901 
902 	if (msg->msg_flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL))
903 		return -ENOTSUPP;
904 
905 	mutex_lock(&tls_ctx->tx_lock);
906 	lock_sock(sk);
907 
908 	if (unlikely(msg->msg_controllen)) {
909 		ret = tls_proccess_cmsg(sk, msg, &record_type);
910 		if (ret) {
911 			if (ret == -EINPROGRESS)
912 				num_async++;
913 			else if (ret != -EAGAIN)
914 				goto send_end;
915 		}
916 	}
917 
918 	while (msg_data_left(msg)) {
919 		if (sk->sk_err) {
920 			ret = -sk->sk_err;
921 			goto send_end;
922 		}
923 
924 		if (ctx->open_rec)
925 			rec = ctx->open_rec;
926 		else
927 			rec = ctx->open_rec = tls_get_rec(sk);
928 		if (!rec) {
929 			ret = -ENOMEM;
930 			goto send_end;
931 		}
932 
933 		msg_pl = &rec->msg_plaintext;
934 		msg_en = &rec->msg_encrypted;
935 
936 		orig_size = msg_pl->sg.size;
937 		full_record = false;
938 		try_to_copy = msg_data_left(msg);
939 		record_room = TLS_MAX_PAYLOAD_SIZE - msg_pl->sg.size;
940 		if (try_to_copy >= record_room) {
941 			try_to_copy = record_room;
942 			full_record = true;
943 		}
944 
945 		required_size = msg_pl->sg.size + try_to_copy +
946 				prot->overhead_size;
947 
948 		if (!sk_stream_memory_free(sk))
949 			goto wait_for_sndbuf;
950 
951 alloc_encrypted:
952 		ret = tls_alloc_encrypted_msg(sk, required_size);
953 		if (ret) {
954 			if (ret != -ENOSPC)
955 				goto wait_for_memory;
956 
957 			/* Adjust try_to_copy according to the amount that was
958 			 * actually allocated. The difference is due
959 			 * to max sg elements limit
960 			 */
961 			try_to_copy -= required_size - msg_en->sg.size;
962 			full_record = true;
963 		}
964 
965 		if (!is_kvec && (full_record || eor) && !async_capable) {
966 			u32 first = msg_pl->sg.end;
967 
968 			ret = sk_msg_zerocopy_from_iter(sk, &msg->msg_iter,
969 							msg_pl, try_to_copy);
970 			if (ret)
971 				goto fallback_to_reg_send;
972 
973 			rec->inplace_crypto = 0;
974 
975 			num_zc++;
976 			copied += try_to_copy;
977 
978 			sk_msg_sg_copy_set(msg_pl, first);
979 			ret = bpf_exec_tx_verdict(msg_pl, sk, full_record,
980 						  record_type, &copied,
981 						  msg->msg_flags);
982 			if (ret) {
983 				if (ret == -EINPROGRESS)
984 					num_async++;
985 				else if (ret == -ENOMEM)
986 					goto wait_for_memory;
987 				else if (ret == -ENOSPC)
988 					goto rollback_iter;
989 				else if (ret != -EAGAIN)
990 					goto send_end;
991 			}
992 			continue;
993 rollback_iter:
994 			copied -= try_to_copy;
995 			sk_msg_sg_copy_clear(msg_pl, first);
996 			iov_iter_revert(&msg->msg_iter,
997 					msg_pl->sg.size - orig_size);
998 fallback_to_reg_send:
999 			sk_msg_trim(sk, msg_pl, orig_size);
1000 		}
1001 
1002 		required_size = msg_pl->sg.size + try_to_copy;
1003 
1004 		ret = tls_clone_plaintext_msg(sk, required_size);
1005 		if (ret) {
1006 			if (ret != -ENOSPC)
1007 				goto send_end;
1008 
1009 			/* Adjust try_to_copy according to the amount that was
1010 			 * actually allocated. The difference is due
1011 			 * to max sg elements limit
1012 			 */
1013 			try_to_copy -= required_size - msg_pl->sg.size;
1014 			full_record = true;
1015 			sk_msg_trim(sk, msg_en,
1016 				    msg_pl->sg.size + prot->overhead_size);
1017 		}
1018 
1019 		if (try_to_copy) {
1020 			ret = sk_msg_memcopy_from_iter(sk, &msg->msg_iter,
1021 						       msg_pl, try_to_copy);
1022 			if (ret < 0)
1023 				goto trim_sgl;
1024 		}
1025 
1026 		/* Open records defined only if successfully copied, otherwise
1027 		 * we would trim the sg but not reset the open record frags.
1028 		 */
1029 		tls_ctx->pending_open_record_frags = true;
1030 		copied += try_to_copy;
1031 		if (full_record || eor) {
1032 			ret = bpf_exec_tx_verdict(msg_pl, sk, full_record,
1033 						  record_type, &copied,
1034 						  msg->msg_flags);
1035 			if (ret) {
1036 				if (ret == -EINPROGRESS)
1037 					num_async++;
1038 				else if (ret == -ENOMEM)
1039 					goto wait_for_memory;
1040 				else if (ret != -EAGAIN) {
1041 					if (ret == -ENOSPC)
1042 						ret = 0;
1043 					goto send_end;
1044 				}
1045 			}
1046 		}
1047 
1048 		continue;
1049 
1050 wait_for_sndbuf:
1051 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1052 wait_for_memory:
1053 		ret = sk_stream_wait_memory(sk, &timeo);
1054 		if (ret) {
1055 trim_sgl:
1056 			tls_trim_both_msgs(sk, orig_size);
1057 			goto send_end;
1058 		}
1059 
1060 		if (msg_en->sg.size < required_size)
1061 			goto alloc_encrypted;
1062 	}
1063 
1064 	if (!num_async) {
1065 		goto send_end;
1066 	} else if (num_zc) {
1067 		/* Wait for pending encryptions to get completed */
1068 		smp_store_mb(ctx->async_notify, true);
1069 
1070 		if (atomic_read(&ctx->encrypt_pending))
1071 			crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
1072 		else
1073 			reinit_completion(&ctx->async_wait.completion);
1074 
1075 		WRITE_ONCE(ctx->async_notify, false);
1076 
1077 		if (ctx->async_wait.err) {
1078 			ret = ctx->async_wait.err;
1079 			copied = 0;
1080 		}
1081 	}
1082 
1083 	/* Transmit if any encryptions have completed */
1084 	if (test_and_clear_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask)) {
1085 		cancel_delayed_work(&ctx->tx_work.work);
1086 		tls_tx_records(sk, msg->msg_flags);
1087 	}
1088 
1089 send_end:
1090 	ret = sk_stream_error(sk, msg->msg_flags, ret);
1091 
1092 	release_sock(sk);
1093 	mutex_unlock(&tls_ctx->tx_lock);
1094 	return copied ? copied : ret;
1095 }
1096 
1097 static int tls_sw_do_sendpage(struct sock *sk, struct page *page,
1098 			      int offset, size_t size, int flags)
1099 {
1100 	long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
1101 	struct tls_context *tls_ctx = tls_get_ctx(sk);
1102 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
1103 	struct tls_prot_info *prot = &tls_ctx->prot_info;
1104 	unsigned char record_type = TLS_RECORD_TYPE_DATA;
1105 	struct sk_msg *msg_pl;
1106 	struct tls_rec *rec;
1107 	int num_async = 0;
1108 	size_t copied = 0;
1109 	bool full_record;
1110 	int record_room;
1111 	int ret = 0;
1112 	bool eor;
1113 
1114 	eor = !(flags & (MSG_MORE | MSG_SENDPAGE_NOTLAST));
1115 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1116 
1117 	/* Call the sk_stream functions to manage the sndbuf mem. */
1118 	while (size > 0) {
1119 		size_t copy, required_size;
1120 
1121 		if (sk->sk_err) {
1122 			ret = -sk->sk_err;
1123 			goto sendpage_end;
1124 		}
1125 
1126 		if (ctx->open_rec)
1127 			rec = ctx->open_rec;
1128 		else
1129 			rec = ctx->open_rec = tls_get_rec(sk);
1130 		if (!rec) {
1131 			ret = -ENOMEM;
1132 			goto sendpage_end;
1133 		}
1134 
1135 		msg_pl = &rec->msg_plaintext;
1136 
1137 		full_record = false;
1138 		record_room = TLS_MAX_PAYLOAD_SIZE - msg_pl->sg.size;
1139 		copy = size;
1140 		if (copy >= record_room) {
1141 			copy = record_room;
1142 			full_record = true;
1143 		}
1144 
1145 		required_size = msg_pl->sg.size + copy + prot->overhead_size;
1146 
1147 		if (!sk_stream_memory_free(sk))
1148 			goto wait_for_sndbuf;
1149 alloc_payload:
1150 		ret = tls_alloc_encrypted_msg(sk, required_size);
1151 		if (ret) {
1152 			if (ret != -ENOSPC)
1153 				goto wait_for_memory;
1154 
1155 			/* Adjust copy according to the amount that was
1156 			 * actually allocated. The difference is due
1157 			 * to max sg elements limit
1158 			 */
1159 			copy -= required_size - msg_pl->sg.size;
1160 			full_record = true;
1161 		}
1162 
1163 		sk_msg_page_add(msg_pl, page, copy, offset);
1164 		sk_mem_charge(sk, copy);
1165 
1166 		offset += copy;
1167 		size -= copy;
1168 		copied += copy;
1169 
1170 		tls_ctx->pending_open_record_frags = true;
1171 		if (full_record || eor || sk_msg_full(msg_pl)) {
1172 			rec->inplace_crypto = 0;
1173 			ret = bpf_exec_tx_verdict(msg_pl, sk, full_record,
1174 						  record_type, &copied, flags);
1175 			if (ret) {
1176 				if (ret == -EINPROGRESS)
1177 					num_async++;
1178 				else if (ret == -ENOMEM)
1179 					goto wait_for_memory;
1180 				else if (ret != -EAGAIN) {
1181 					if (ret == -ENOSPC)
1182 						ret = 0;
1183 					goto sendpage_end;
1184 				}
1185 			}
1186 		}
1187 		continue;
1188 wait_for_sndbuf:
1189 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1190 wait_for_memory:
1191 		ret = sk_stream_wait_memory(sk, &timeo);
1192 		if (ret) {
1193 			tls_trim_both_msgs(sk, msg_pl->sg.size);
1194 			goto sendpage_end;
1195 		}
1196 
1197 		goto alloc_payload;
1198 	}
1199 
1200 	if (num_async) {
1201 		/* Transmit if any encryptions have completed */
1202 		if (test_and_clear_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask)) {
1203 			cancel_delayed_work(&ctx->tx_work.work);
1204 			tls_tx_records(sk, flags);
1205 		}
1206 	}
1207 sendpage_end:
1208 	ret = sk_stream_error(sk, flags, ret);
1209 	return copied ? copied : ret;
1210 }
1211 
1212 int tls_sw_sendpage(struct sock *sk, struct page *page,
1213 		    int offset, size_t size, int flags)
1214 {
1215 	struct tls_context *tls_ctx = tls_get_ctx(sk);
1216 	int ret;
1217 
1218 	if (flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL |
1219 		      MSG_SENDPAGE_NOTLAST | MSG_SENDPAGE_NOPOLICY))
1220 		return -ENOTSUPP;
1221 
1222 	mutex_lock(&tls_ctx->tx_lock);
1223 	lock_sock(sk);
1224 	ret = tls_sw_do_sendpage(sk, page, offset, size, flags);
1225 	release_sock(sk);
1226 	mutex_unlock(&tls_ctx->tx_lock);
1227 	return ret;
1228 }
1229 
1230 static struct sk_buff *tls_wait_data(struct sock *sk, struct sk_psock *psock,
1231 				     int flags, long timeo, int *err)
1232 {
1233 	struct tls_context *tls_ctx = tls_get_ctx(sk);
1234 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
1235 	struct sk_buff *skb;
1236 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
1237 
1238 	while (!(skb = ctx->recv_pkt) && sk_psock_queue_empty(psock)) {
1239 		if (sk->sk_err) {
1240 			*err = sock_error(sk);
1241 			return NULL;
1242 		}
1243 
1244 		if (sk->sk_shutdown & RCV_SHUTDOWN)
1245 			return NULL;
1246 
1247 		if (sock_flag(sk, SOCK_DONE))
1248 			return NULL;
1249 
1250 		if ((flags & MSG_DONTWAIT) || !timeo) {
1251 			*err = -EAGAIN;
1252 			return NULL;
1253 		}
1254 
1255 		add_wait_queue(sk_sleep(sk), &wait);
1256 		sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
1257 		sk_wait_event(sk, &timeo,
1258 			      ctx->recv_pkt != skb ||
1259 			      !sk_psock_queue_empty(psock),
1260 			      &wait);
1261 		sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
1262 		remove_wait_queue(sk_sleep(sk), &wait);
1263 
1264 		/* Handle signals */
1265 		if (signal_pending(current)) {
1266 			*err = sock_intr_errno(timeo);
1267 			return NULL;
1268 		}
1269 	}
1270 
1271 	return skb;
1272 }
1273 
1274 static int tls_setup_from_iter(struct sock *sk, struct iov_iter *from,
1275 			       int length, int *pages_used,
1276 			       unsigned int *size_used,
1277 			       struct scatterlist *to,
1278 			       int to_max_pages)
1279 {
1280 	int rc = 0, i = 0, num_elem = *pages_used, maxpages;
1281 	struct page *pages[MAX_SKB_FRAGS];
1282 	unsigned int size = *size_used;
1283 	ssize_t copied, use;
1284 	size_t offset;
1285 
1286 	while (length > 0) {
1287 		i = 0;
1288 		maxpages = to_max_pages - num_elem;
1289 		if (maxpages == 0) {
1290 			rc = -EFAULT;
1291 			goto out;
1292 		}
1293 		copied = iov_iter_get_pages(from, pages,
1294 					    length,
1295 					    maxpages, &offset);
1296 		if (copied <= 0) {
1297 			rc = -EFAULT;
1298 			goto out;
1299 		}
1300 
1301 		iov_iter_advance(from, copied);
1302 
1303 		length -= copied;
1304 		size += copied;
1305 		while (copied) {
1306 			use = min_t(int, copied, PAGE_SIZE - offset);
1307 
1308 			sg_set_page(&to[num_elem],
1309 				    pages[i], use, offset);
1310 			sg_unmark_end(&to[num_elem]);
1311 			/* We do not uncharge memory from this API */
1312 
1313 			offset = 0;
1314 			copied -= use;
1315 
1316 			i++;
1317 			num_elem++;
1318 		}
1319 	}
1320 	/* Mark the end in the last sg entry if newly added */
1321 	if (num_elem > *pages_used)
1322 		sg_mark_end(&to[num_elem - 1]);
1323 out:
1324 	if (rc)
1325 		iov_iter_revert(from, size - *size_used);
1326 	*size_used = size;
1327 	*pages_used = num_elem;
1328 
1329 	return rc;
1330 }
1331 
1332 /* This function decrypts the input skb into either out_iov or in out_sg
1333  * or in skb buffers itself. The input parameter 'zc' indicates if
1334  * zero-copy mode needs to be tried or not. With zero-copy mode, either
1335  * out_iov or out_sg must be non-NULL. In case both out_iov and out_sg are
1336  * NULL, then the decryption happens inside skb buffers itself, i.e.
1337  * zero-copy gets disabled and 'zc' is updated.
1338  */
1339 
1340 static int decrypt_internal(struct sock *sk, struct sk_buff *skb,
1341 			    struct iov_iter *out_iov,
1342 			    struct scatterlist *out_sg,
1343 			    int *chunk, bool *zc, bool async)
1344 {
1345 	struct tls_context *tls_ctx = tls_get_ctx(sk);
1346 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
1347 	struct tls_prot_info *prot = &tls_ctx->prot_info;
1348 	struct strp_msg *rxm = strp_msg(skb);
1349 	int n_sgin, n_sgout, nsg, mem_size, aead_size, err, pages = 0;
1350 	struct aead_request *aead_req;
1351 	struct sk_buff *unused;
1352 	u8 *aad, *iv, *mem = NULL;
1353 	struct scatterlist *sgin = NULL;
1354 	struct scatterlist *sgout = NULL;
1355 	const int data_len = rxm->full_len - prot->overhead_size +
1356 			     prot->tail_size;
1357 	int iv_offset = 0;
1358 
1359 	if (*zc && (out_iov || out_sg)) {
1360 		if (out_iov)
1361 			n_sgout = iov_iter_npages(out_iov, INT_MAX) + 1;
1362 		else
1363 			n_sgout = sg_nents(out_sg);
1364 		n_sgin = skb_nsg(skb, rxm->offset + prot->prepend_size,
1365 				 rxm->full_len - prot->prepend_size);
1366 	} else {
1367 		n_sgout = 0;
1368 		*zc = false;
1369 		n_sgin = skb_cow_data(skb, 0, &unused);
1370 	}
1371 
1372 	if (n_sgin < 1)
1373 		return -EBADMSG;
1374 
1375 	/* Increment to accommodate AAD */
1376 	n_sgin = n_sgin + 1;
1377 
1378 	nsg = n_sgin + n_sgout;
1379 
1380 	aead_size = sizeof(*aead_req) + crypto_aead_reqsize(ctx->aead_recv);
1381 	mem_size = aead_size + (nsg * sizeof(struct scatterlist));
1382 	mem_size = mem_size + prot->aad_size;
1383 	mem_size = mem_size + crypto_aead_ivsize(ctx->aead_recv);
1384 
1385 	/* Allocate a single block of memory which contains
1386 	 * aead_req || sgin[] || sgout[] || aad || iv.
1387 	 * This order achieves correct alignment for aead_req, sgin, sgout.
1388 	 */
1389 	mem = kmalloc(mem_size, sk->sk_allocation);
1390 	if (!mem)
1391 		return -ENOMEM;
1392 
1393 	/* Segment the allocated memory */
1394 	aead_req = (struct aead_request *)mem;
1395 	sgin = (struct scatterlist *)(mem + aead_size);
1396 	sgout = sgin + n_sgin;
1397 	aad = (u8 *)(sgout + n_sgout);
1398 	iv = aad + prot->aad_size;
1399 
1400 	/* For CCM based ciphers, first byte of nonce+iv is always '2' */
1401 	if (prot->cipher_type == TLS_CIPHER_AES_CCM_128) {
1402 		iv[0] = 2;
1403 		iv_offset = 1;
1404 	}
1405 
1406 	/* Prepare IV */
1407 	err = skb_copy_bits(skb, rxm->offset + TLS_HEADER_SIZE,
1408 			    iv + iv_offset + prot->salt_size,
1409 			    prot->iv_size);
1410 	if (err < 0) {
1411 		kfree(mem);
1412 		return err;
1413 	}
1414 	if (prot->version == TLS_1_3_VERSION)
1415 		memcpy(iv + iv_offset, tls_ctx->rx.iv,
1416 		       crypto_aead_ivsize(ctx->aead_recv));
1417 	else
1418 		memcpy(iv + iv_offset, tls_ctx->rx.iv, prot->salt_size);
1419 
1420 	xor_iv_with_seq(prot->version, iv, tls_ctx->rx.rec_seq);
1421 
1422 	/* Prepare AAD */
1423 	tls_make_aad(aad, rxm->full_len - prot->overhead_size +
1424 		     prot->tail_size,
1425 		     tls_ctx->rx.rec_seq, prot->rec_seq_size,
1426 		     ctx->control, prot->version);
1427 
1428 	/* Prepare sgin */
1429 	sg_init_table(sgin, n_sgin);
1430 	sg_set_buf(&sgin[0], aad, prot->aad_size);
1431 	err = skb_to_sgvec(skb, &sgin[1],
1432 			   rxm->offset + prot->prepend_size,
1433 			   rxm->full_len - prot->prepend_size);
1434 	if (err < 0) {
1435 		kfree(mem);
1436 		return err;
1437 	}
1438 
1439 	if (n_sgout) {
1440 		if (out_iov) {
1441 			sg_init_table(sgout, n_sgout);
1442 			sg_set_buf(&sgout[0], aad, prot->aad_size);
1443 
1444 			*chunk = 0;
1445 			err = tls_setup_from_iter(sk, out_iov, data_len,
1446 						  &pages, chunk, &sgout[1],
1447 						  (n_sgout - 1));
1448 			if (err < 0)
1449 				goto fallback_to_reg_recv;
1450 		} else if (out_sg) {
1451 			memcpy(sgout, out_sg, n_sgout * sizeof(*sgout));
1452 		} else {
1453 			goto fallback_to_reg_recv;
1454 		}
1455 	} else {
1456 fallback_to_reg_recv:
1457 		sgout = sgin;
1458 		pages = 0;
1459 		*chunk = data_len;
1460 		*zc = false;
1461 	}
1462 
1463 	/* Prepare and submit AEAD request */
1464 	err = tls_do_decryption(sk, skb, sgin, sgout, iv,
1465 				data_len, aead_req, async);
1466 	if (err == -EINPROGRESS)
1467 		return err;
1468 
1469 	/* Release the pages in case iov was mapped to pages */
1470 	for (; pages > 0; pages--)
1471 		put_page(sg_page(&sgout[pages]));
1472 
1473 	kfree(mem);
1474 	return err;
1475 }
1476 
1477 static int decrypt_skb_update(struct sock *sk, struct sk_buff *skb,
1478 			      struct iov_iter *dest, int *chunk, bool *zc,
1479 			      bool async)
1480 {
1481 	struct tls_context *tls_ctx = tls_get_ctx(sk);
1482 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
1483 	struct tls_prot_info *prot = &tls_ctx->prot_info;
1484 	struct strp_msg *rxm = strp_msg(skb);
1485 	int pad, err = 0;
1486 
1487 	if (!ctx->decrypted) {
1488 		if (tls_ctx->rx_conf == TLS_HW) {
1489 			err = tls_device_decrypted(sk, tls_ctx, skb, rxm);
1490 			if (err < 0)
1491 				return err;
1492 		}
1493 
1494 		/* Still not decrypted after tls_device */
1495 		if (!ctx->decrypted) {
1496 			err = decrypt_internal(sk, skb, dest, NULL, chunk, zc,
1497 					       async);
1498 			if (err < 0) {
1499 				if (err == -EINPROGRESS)
1500 					tls_advance_record_sn(sk, prot,
1501 							      &tls_ctx->rx);
1502 
1503 				return err;
1504 			}
1505 		} else {
1506 			*zc = false;
1507 		}
1508 
1509 		pad = padding_length(ctx, prot, skb);
1510 		if (pad < 0)
1511 			return pad;
1512 
1513 		rxm->full_len -= pad;
1514 		rxm->offset += prot->prepend_size;
1515 		rxm->full_len -= prot->overhead_size;
1516 		tls_advance_record_sn(sk, prot, &tls_ctx->rx);
1517 		ctx->decrypted = 1;
1518 		ctx->saved_data_ready(sk);
1519 	} else {
1520 		*zc = false;
1521 	}
1522 
1523 	return err;
1524 }
1525 
1526 int decrypt_skb(struct sock *sk, struct sk_buff *skb,
1527 		struct scatterlist *sgout)
1528 {
1529 	bool zc = true;
1530 	int chunk;
1531 
1532 	return decrypt_internal(sk, skb, NULL, sgout, &chunk, &zc, false);
1533 }
1534 
1535 static bool tls_sw_advance_skb(struct sock *sk, struct sk_buff *skb,
1536 			       unsigned int len)
1537 {
1538 	struct tls_context *tls_ctx = tls_get_ctx(sk);
1539 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
1540 
1541 	if (skb) {
1542 		struct strp_msg *rxm = strp_msg(skb);
1543 
1544 		if (len < rxm->full_len) {
1545 			rxm->offset += len;
1546 			rxm->full_len -= len;
1547 			return false;
1548 		}
1549 		consume_skb(skb);
1550 	}
1551 
1552 	/* Finished with message */
1553 	ctx->recv_pkt = NULL;
1554 	__strp_unpause(&ctx->strp);
1555 
1556 	return true;
1557 }
1558 
1559 /* This function traverses the rx_list in tls receive context to copies the
1560  * decrypted records into the buffer provided by caller zero copy is not
1561  * true. Further, the records are removed from the rx_list if it is not a peek
1562  * case and the record has been consumed completely.
1563  */
1564 static int process_rx_list(struct tls_sw_context_rx *ctx,
1565 			   struct msghdr *msg,
1566 			   u8 *control,
1567 			   bool *cmsg,
1568 			   size_t skip,
1569 			   size_t len,
1570 			   bool zc,
1571 			   bool is_peek)
1572 {
1573 	struct sk_buff *skb = skb_peek(&ctx->rx_list);
1574 	u8 ctrl = *control;
1575 	u8 msgc = *cmsg;
1576 	struct tls_msg *tlm;
1577 	ssize_t copied = 0;
1578 
1579 	/* Set the record type in 'control' if caller didn't pass it */
1580 	if (!ctrl && skb) {
1581 		tlm = tls_msg(skb);
1582 		ctrl = tlm->control;
1583 	}
1584 
1585 	while (skip && skb) {
1586 		struct strp_msg *rxm = strp_msg(skb);
1587 		tlm = tls_msg(skb);
1588 
1589 		/* Cannot process a record of different type */
1590 		if (ctrl != tlm->control)
1591 			return 0;
1592 
1593 		if (skip < rxm->full_len)
1594 			break;
1595 
1596 		skip = skip - rxm->full_len;
1597 		skb = skb_peek_next(skb, &ctx->rx_list);
1598 	}
1599 
1600 	while (len && skb) {
1601 		struct sk_buff *next_skb;
1602 		struct strp_msg *rxm = strp_msg(skb);
1603 		int chunk = min_t(unsigned int, rxm->full_len - skip, len);
1604 
1605 		tlm = tls_msg(skb);
1606 
1607 		/* Cannot process a record of different type */
1608 		if (ctrl != tlm->control)
1609 			return 0;
1610 
1611 		/* Set record type if not already done. For a non-data record,
1612 		 * do not proceed if record type could not be copied.
1613 		 */
1614 		if (!msgc) {
1615 			int cerr = put_cmsg(msg, SOL_TLS, TLS_GET_RECORD_TYPE,
1616 					    sizeof(ctrl), &ctrl);
1617 			msgc = true;
1618 			if (ctrl != TLS_RECORD_TYPE_DATA) {
1619 				if (cerr || msg->msg_flags & MSG_CTRUNC)
1620 					return -EIO;
1621 
1622 				*cmsg = msgc;
1623 			}
1624 		}
1625 
1626 		if (!zc || (rxm->full_len - skip) > len) {
1627 			int err = skb_copy_datagram_msg(skb, rxm->offset + skip,
1628 						    msg, chunk);
1629 			if (err < 0)
1630 				return err;
1631 		}
1632 
1633 		len = len - chunk;
1634 		copied = copied + chunk;
1635 
1636 		/* Consume the data from record if it is non-peek case*/
1637 		if (!is_peek) {
1638 			rxm->offset = rxm->offset + chunk;
1639 			rxm->full_len = rxm->full_len - chunk;
1640 
1641 			/* Return if there is unconsumed data in the record */
1642 			if (rxm->full_len - skip)
1643 				break;
1644 		}
1645 
1646 		/* The remaining skip-bytes must lie in 1st record in rx_list.
1647 		 * So from the 2nd record, 'skip' should be 0.
1648 		 */
1649 		skip = 0;
1650 
1651 		if (msg)
1652 			msg->msg_flags |= MSG_EOR;
1653 
1654 		next_skb = skb_peek_next(skb, &ctx->rx_list);
1655 
1656 		if (!is_peek) {
1657 			skb_unlink(skb, &ctx->rx_list);
1658 			consume_skb(skb);
1659 		}
1660 
1661 		skb = next_skb;
1662 	}
1663 
1664 	*control = ctrl;
1665 	return copied;
1666 }
1667 
1668 int tls_sw_recvmsg(struct sock *sk,
1669 		   struct msghdr *msg,
1670 		   size_t len,
1671 		   int nonblock,
1672 		   int flags,
1673 		   int *addr_len)
1674 {
1675 	struct tls_context *tls_ctx = tls_get_ctx(sk);
1676 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
1677 	struct tls_prot_info *prot = &tls_ctx->prot_info;
1678 	struct sk_psock *psock;
1679 	unsigned char control = 0;
1680 	ssize_t decrypted = 0;
1681 	struct strp_msg *rxm;
1682 	struct tls_msg *tlm;
1683 	struct sk_buff *skb;
1684 	ssize_t copied = 0;
1685 	bool cmsg = false;
1686 	int target, err = 0;
1687 	long timeo;
1688 	bool is_kvec = iov_iter_is_kvec(&msg->msg_iter);
1689 	bool is_peek = flags & MSG_PEEK;
1690 	int num_async = 0;
1691 
1692 	flags |= nonblock;
1693 
1694 	if (unlikely(flags & MSG_ERRQUEUE))
1695 		return sock_recv_errqueue(sk, msg, len, SOL_IP, IP_RECVERR);
1696 
1697 	psock = sk_psock_get(sk);
1698 	lock_sock(sk);
1699 
1700 	/* Process pending decrypted records. It must be non-zero-copy */
1701 	err = process_rx_list(ctx, msg, &control, &cmsg, 0, len, false,
1702 			      is_peek);
1703 	if (err < 0) {
1704 		tls_err_abort(sk, err);
1705 		goto end;
1706 	} else {
1707 		copied = err;
1708 	}
1709 
1710 	if (len <= copied)
1711 		goto recv_end;
1712 
1713 	target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
1714 	len = len - copied;
1715 	timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
1716 
1717 	while (len && (decrypted + copied < target || ctx->recv_pkt)) {
1718 		bool retain_skb = false;
1719 		bool zc = false;
1720 		int to_decrypt;
1721 		int chunk = 0;
1722 		bool async_capable;
1723 		bool async = false;
1724 
1725 		skb = tls_wait_data(sk, psock, flags, timeo, &err);
1726 		if (!skb) {
1727 			if (psock) {
1728 				int ret = __tcp_bpf_recvmsg(sk, psock,
1729 							    msg, len, flags);
1730 
1731 				if (ret > 0) {
1732 					decrypted += ret;
1733 					len -= ret;
1734 					continue;
1735 				}
1736 			}
1737 			goto recv_end;
1738 		} else {
1739 			tlm = tls_msg(skb);
1740 			if (prot->version == TLS_1_3_VERSION)
1741 				tlm->control = 0;
1742 			else
1743 				tlm->control = ctx->control;
1744 		}
1745 
1746 		rxm = strp_msg(skb);
1747 
1748 		to_decrypt = rxm->full_len - prot->overhead_size;
1749 
1750 		if (to_decrypt <= len && !is_kvec && !is_peek &&
1751 		    ctx->control == TLS_RECORD_TYPE_DATA &&
1752 		    prot->version != TLS_1_3_VERSION)
1753 			zc = true;
1754 
1755 		/* Do not use async mode if record is non-data */
1756 		if (ctx->control == TLS_RECORD_TYPE_DATA)
1757 			async_capable = ctx->async_capable;
1758 		else
1759 			async_capable = false;
1760 
1761 		err = decrypt_skb_update(sk, skb, &msg->msg_iter,
1762 					 &chunk, &zc, async_capable);
1763 		if (err < 0 && err != -EINPROGRESS) {
1764 			tls_err_abort(sk, EBADMSG);
1765 			goto recv_end;
1766 		}
1767 
1768 		if (err == -EINPROGRESS) {
1769 			async = true;
1770 			num_async++;
1771 		} else if (prot->version == TLS_1_3_VERSION) {
1772 			tlm->control = ctx->control;
1773 		}
1774 
1775 		/* If the type of records being processed is not known yet,
1776 		 * set it to record type just dequeued. If it is already known,
1777 		 * but does not match the record type just dequeued, go to end.
1778 		 * We always get record type here since for tls1.2, record type
1779 		 * is known just after record is dequeued from stream parser.
1780 		 * For tls1.3, we disable async.
1781 		 */
1782 
1783 		if (!control)
1784 			control = tlm->control;
1785 		else if (control != tlm->control)
1786 			goto recv_end;
1787 
1788 		if (!cmsg) {
1789 			int cerr;
1790 
1791 			cerr = put_cmsg(msg, SOL_TLS, TLS_GET_RECORD_TYPE,
1792 					sizeof(control), &control);
1793 			cmsg = true;
1794 			if (control != TLS_RECORD_TYPE_DATA) {
1795 				if (cerr || msg->msg_flags & MSG_CTRUNC) {
1796 					err = -EIO;
1797 					goto recv_end;
1798 				}
1799 			}
1800 		}
1801 
1802 		if (async)
1803 			goto pick_next_record;
1804 
1805 		if (!zc) {
1806 			if (rxm->full_len > len) {
1807 				retain_skb = true;
1808 				chunk = len;
1809 			} else {
1810 				chunk = rxm->full_len;
1811 			}
1812 
1813 			err = skb_copy_datagram_msg(skb, rxm->offset,
1814 						    msg, chunk);
1815 			if (err < 0)
1816 				goto recv_end;
1817 
1818 			if (!is_peek) {
1819 				rxm->offset = rxm->offset + chunk;
1820 				rxm->full_len = rxm->full_len - chunk;
1821 			}
1822 		}
1823 
1824 pick_next_record:
1825 		if (chunk > len)
1826 			chunk = len;
1827 
1828 		decrypted += chunk;
1829 		len -= chunk;
1830 
1831 		/* For async or peek case, queue the current skb */
1832 		if (async || is_peek || retain_skb) {
1833 			skb_queue_tail(&ctx->rx_list, skb);
1834 			skb = NULL;
1835 		}
1836 
1837 		if (tls_sw_advance_skb(sk, skb, chunk)) {
1838 			/* Return full control message to
1839 			 * userspace before trying to parse
1840 			 * another message type
1841 			 */
1842 			msg->msg_flags |= MSG_EOR;
1843 			if (ctx->control != TLS_RECORD_TYPE_DATA)
1844 				goto recv_end;
1845 		} else {
1846 			break;
1847 		}
1848 	}
1849 
1850 recv_end:
1851 	if (num_async) {
1852 		/* Wait for all previously submitted records to be decrypted */
1853 		smp_store_mb(ctx->async_notify, true);
1854 		if (atomic_read(&ctx->decrypt_pending)) {
1855 			err = crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
1856 			if (err) {
1857 				/* one of async decrypt failed */
1858 				tls_err_abort(sk, err);
1859 				copied = 0;
1860 				decrypted = 0;
1861 				goto end;
1862 			}
1863 		} else {
1864 			reinit_completion(&ctx->async_wait.completion);
1865 		}
1866 		WRITE_ONCE(ctx->async_notify, false);
1867 
1868 		/* Drain records from the rx_list & copy if required */
1869 		if (is_peek || is_kvec)
1870 			err = process_rx_list(ctx, msg, &control, &cmsg, copied,
1871 					      decrypted, false, is_peek);
1872 		else
1873 			err = process_rx_list(ctx, msg, &control, &cmsg, 0,
1874 					      decrypted, true, is_peek);
1875 		if (err < 0) {
1876 			tls_err_abort(sk, err);
1877 			copied = 0;
1878 			goto end;
1879 		}
1880 	}
1881 
1882 	copied += decrypted;
1883 
1884 end:
1885 	release_sock(sk);
1886 	if (psock)
1887 		sk_psock_put(sk, psock);
1888 	return copied ? : err;
1889 }
1890 
1891 ssize_t tls_sw_splice_read(struct socket *sock,  loff_t *ppos,
1892 			   struct pipe_inode_info *pipe,
1893 			   size_t len, unsigned int flags)
1894 {
1895 	struct tls_context *tls_ctx = tls_get_ctx(sock->sk);
1896 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
1897 	struct strp_msg *rxm = NULL;
1898 	struct sock *sk = sock->sk;
1899 	struct sk_buff *skb;
1900 	ssize_t copied = 0;
1901 	int err = 0;
1902 	long timeo;
1903 	int chunk;
1904 	bool zc = false;
1905 
1906 	lock_sock(sk);
1907 
1908 	timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
1909 
1910 	skb = tls_wait_data(sk, NULL, flags, timeo, &err);
1911 	if (!skb)
1912 		goto splice_read_end;
1913 
1914 	if (!ctx->decrypted) {
1915 		err = decrypt_skb_update(sk, skb, NULL, &chunk, &zc, false);
1916 
1917 		/* splice does not support reading control messages */
1918 		if (ctx->control != TLS_RECORD_TYPE_DATA) {
1919 			err = -ENOTSUPP;
1920 			goto splice_read_end;
1921 		}
1922 
1923 		if (err < 0) {
1924 			tls_err_abort(sk, EBADMSG);
1925 			goto splice_read_end;
1926 		}
1927 		ctx->decrypted = 1;
1928 	}
1929 	rxm = strp_msg(skb);
1930 
1931 	chunk = min_t(unsigned int, rxm->full_len, len);
1932 	copied = skb_splice_bits(skb, sk, rxm->offset, pipe, chunk, flags);
1933 	if (copied < 0)
1934 		goto splice_read_end;
1935 
1936 	if (likely(!(flags & MSG_PEEK)))
1937 		tls_sw_advance_skb(sk, skb, copied);
1938 
1939 splice_read_end:
1940 	release_sock(sk);
1941 	return copied ? : err;
1942 }
1943 
1944 bool tls_sw_stream_read(const struct sock *sk)
1945 {
1946 	struct tls_context *tls_ctx = tls_get_ctx(sk);
1947 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
1948 	bool ingress_empty = true;
1949 	struct sk_psock *psock;
1950 
1951 	rcu_read_lock();
1952 	psock = sk_psock(sk);
1953 	if (psock)
1954 		ingress_empty = list_empty(&psock->ingress_msg);
1955 	rcu_read_unlock();
1956 
1957 	return !ingress_empty || ctx->recv_pkt ||
1958 		!skb_queue_empty(&ctx->rx_list);
1959 }
1960 
1961 static int tls_read_size(struct strparser *strp, struct sk_buff *skb)
1962 {
1963 	struct tls_context *tls_ctx = tls_get_ctx(strp->sk);
1964 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
1965 	struct tls_prot_info *prot = &tls_ctx->prot_info;
1966 	char header[TLS_HEADER_SIZE + MAX_IV_SIZE];
1967 	struct strp_msg *rxm = strp_msg(skb);
1968 	size_t cipher_overhead;
1969 	size_t data_len = 0;
1970 	int ret;
1971 
1972 	/* Verify that we have a full TLS header, or wait for more data */
1973 	if (rxm->offset + prot->prepend_size > skb->len)
1974 		return 0;
1975 
1976 	/* Sanity-check size of on-stack buffer. */
1977 	if (WARN_ON(prot->prepend_size > sizeof(header))) {
1978 		ret = -EINVAL;
1979 		goto read_failure;
1980 	}
1981 
1982 	/* Linearize header to local buffer */
1983 	ret = skb_copy_bits(skb, rxm->offset, header, prot->prepend_size);
1984 
1985 	if (ret < 0)
1986 		goto read_failure;
1987 
1988 	ctx->control = header[0];
1989 
1990 	data_len = ((header[4] & 0xFF) | (header[3] << 8));
1991 
1992 	cipher_overhead = prot->tag_size;
1993 	if (prot->version != TLS_1_3_VERSION)
1994 		cipher_overhead += prot->iv_size;
1995 
1996 	if (data_len > TLS_MAX_PAYLOAD_SIZE + cipher_overhead +
1997 	    prot->tail_size) {
1998 		ret = -EMSGSIZE;
1999 		goto read_failure;
2000 	}
2001 	if (data_len < cipher_overhead) {
2002 		ret = -EBADMSG;
2003 		goto read_failure;
2004 	}
2005 
2006 	/* Note that both TLS1.3 and TLS1.2 use TLS_1_2 version here */
2007 	if (header[1] != TLS_1_2_VERSION_MINOR ||
2008 	    header[2] != TLS_1_2_VERSION_MAJOR) {
2009 		ret = -EINVAL;
2010 		goto read_failure;
2011 	}
2012 
2013 	tls_device_rx_resync_new_rec(strp->sk, data_len + TLS_HEADER_SIZE,
2014 				     TCP_SKB_CB(skb)->seq + rxm->offset);
2015 	return data_len + TLS_HEADER_SIZE;
2016 
2017 read_failure:
2018 	tls_err_abort(strp->sk, ret);
2019 
2020 	return ret;
2021 }
2022 
2023 static void tls_queue(struct strparser *strp, struct sk_buff *skb)
2024 {
2025 	struct tls_context *tls_ctx = tls_get_ctx(strp->sk);
2026 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
2027 
2028 	ctx->decrypted = 0;
2029 
2030 	ctx->recv_pkt = skb;
2031 	strp_pause(strp);
2032 
2033 	ctx->saved_data_ready(strp->sk);
2034 }
2035 
2036 static void tls_data_ready(struct sock *sk)
2037 {
2038 	struct tls_context *tls_ctx = tls_get_ctx(sk);
2039 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
2040 	struct sk_psock *psock;
2041 
2042 	strp_data_ready(&ctx->strp);
2043 
2044 	psock = sk_psock_get(sk);
2045 	if (psock && !list_empty(&psock->ingress_msg)) {
2046 		ctx->saved_data_ready(sk);
2047 		sk_psock_put(sk, psock);
2048 	}
2049 }
2050 
2051 void tls_sw_cancel_work_tx(struct tls_context *tls_ctx)
2052 {
2053 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
2054 
2055 	set_bit(BIT_TX_CLOSING, &ctx->tx_bitmask);
2056 	set_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask);
2057 	cancel_delayed_work_sync(&ctx->tx_work.work);
2058 }
2059 
2060 void tls_sw_release_resources_tx(struct sock *sk)
2061 {
2062 	struct tls_context *tls_ctx = tls_get_ctx(sk);
2063 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
2064 	struct tls_rec *rec, *tmp;
2065 
2066 	/* Wait for any pending async encryptions to complete */
2067 	smp_store_mb(ctx->async_notify, true);
2068 	if (atomic_read(&ctx->encrypt_pending))
2069 		crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
2070 
2071 	tls_tx_records(sk, -1);
2072 
2073 	/* Free up un-sent records in tx_list. First, free
2074 	 * the partially sent record if any at head of tx_list.
2075 	 */
2076 	if (tls_free_partial_record(sk, tls_ctx)) {
2077 		rec = list_first_entry(&ctx->tx_list,
2078 				       struct tls_rec, list);
2079 		list_del(&rec->list);
2080 		sk_msg_free(sk, &rec->msg_plaintext);
2081 		kfree(rec);
2082 	}
2083 
2084 	list_for_each_entry_safe(rec, tmp, &ctx->tx_list, list) {
2085 		list_del(&rec->list);
2086 		sk_msg_free(sk, &rec->msg_encrypted);
2087 		sk_msg_free(sk, &rec->msg_plaintext);
2088 		kfree(rec);
2089 	}
2090 
2091 	crypto_free_aead(ctx->aead_send);
2092 	tls_free_open_rec(sk);
2093 }
2094 
2095 void tls_sw_free_ctx_tx(struct tls_context *tls_ctx)
2096 {
2097 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
2098 
2099 	kfree(ctx);
2100 }
2101 
2102 void tls_sw_release_resources_rx(struct sock *sk)
2103 {
2104 	struct tls_context *tls_ctx = tls_get_ctx(sk);
2105 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
2106 
2107 	kfree(tls_ctx->rx.rec_seq);
2108 	kfree(tls_ctx->rx.iv);
2109 
2110 	if (ctx->aead_recv) {
2111 		kfree_skb(ctx->recv_pkt);
2112 		ctx->recv_pkt = NULL;
2113 		skb_queue_purge(&ctx->rx_list);
2114 		crypto_free_aead(ctx->aead_recv);
2115 		strp_stop(&ctx->strp);
2116 		/* If tls_sw_strparser_arm() was not called (cleanup paths)
2117 		 * we still want to strp_stop(), but sk->sk_data_ready was
2118 		 * never swapped.
2119 		 */
2120 		if (ctx->saved_data_ready) {
2121 			write_lock_bh(&sk->sk_callback_lock);
2122 			sk->sk_data_ready = ctx->saved_data_ready;
2123 			write_unlock_bh(&sk->sk_callback_lock);
2124 		}
2125 	}
2126 }
2127 
2128 void tls_sw_strparser_done(struct tls_context *tls_ctx)
2129 {
2130 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
2131 
2132 	strp_done(&ctx->strp);
2133 }
2134 
2135 void tls_sw_free_ctx_rx(struct tls_context *tls_ctx)
2136 {
2137 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
2138 
2139 	kfree(ctx);
2140 }
2141 
2142 void tls_sw_free_resources_rx(struct sock *sk)
2143 {
2144 	struct tls_context *tls_ctx = tls_get_ctx(sk);
2145 
2146 	tls_sw_release_resources_rx(sk);
2147 	tls_sw_free_ctx_rx(tls_ctx);
2148 }
2149 
2150 /* The work handler to transmitt the encrypted records in tx_list */
2151 static void tx_work_handler(struct work_struct *work)
2152 {
2153 	struct delayed_work *delayed_work = to_delayed_work(work);
2154 	struct tx_work *tx_work = container_of(delayed_work,
2155 					       struct tx_work, work);
2156 	struct sock *sk = tx_work->sk;
2157 	struct tls_context *tls_ctx = tls_get_ctx(sk);
2158 	struct tls_sw_context_tx *ctx;
2159 
2160 	if (unlikely(!tls_ctx))
2161 		return;
2162 
2163 	ctx = tls_sw_ctx_tx(tls_ctx);
2164 	if (test_bit(BIT_TX_CLOSING, &ctx->tx_bitmask))
2165 		return;
2166 
2167 	if (!test_and_clear_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask))
2168 		return;
2169 	mutex_lock(&tls_ctx->tx_lock);
2170 	lock_sock(sk);
2171 	tls_tx_records(sk, -1);
2172 	release_sock(sk);
2173 	mutex_unlock(&tls_ctx->tx_lock);
2174 }
2175 
2176 void tls_sw_write_space(struct sock *sk, struct tls_context *ctx)
2177 {
2178 	struct tls_sw_context_tx *tx_ctx = tls_sw_ctx_tx(ctx);
2179 
2180 	/* Schedule the transmission if tx list is ready */
2181 	if (is_tx_ready(tx_ctx) &&
2182 	    !test_and_set_bit(BIT_TX_SCHEDULED, &tx_ctx->tx_bitmask))
2183 		schedule_delayed_work(&tx_ctx->tx_work.work, 0);
2184 }
2185 
2186 void tls_sw_strparser_arm(struct sock *sk, struct tls_context *tls_ctx)
2187 {
2188 	struct tls_sw_context_rx *rx_ctx = tls_sw_ctx_rx(tls_ctx);
2189 
2190 	write_lock_bh(&sk->sk_callback_lock);
2191 	rx_ctx->saved_data_ready = sk->sk_data_ready;
2192 	sk->sk_data_ready = tls_data_ready;
2193 	write_unlock_bh(&sk->sk_callback_lock);
2194 
2195 	strp_check_rcv(&rx_ctx->strp);
2196 }
2197 
2198 int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx)
2199 {
2200 	struct tls_context *tls_ctx = tls_get_ctx(sk);
2201 	struct tls_prot_info *prot = &tls_ctx->prot_info;
2202 	struct tls_crypto_info *crypto_info;
2203 	struct tls12_crypto_info_aes_gcm_128 *gcm_128_info;
2204 	struct tls12_crypto_info_aes_gcm_256 *gcm_256_info;
2205 	struct tls12_crypto_info_aes_ccm_128 *ccm_128_info;
2206 	struct tls_sw_context_tx *sw_ctx_tx = NULL;
2207 	struct tls_sw_context_rx *sw_ctx_rx = NULL;
2208 	struct cipher_context *cctx;
2209 	struct crypto_aead **aead;
2210 	struct strp_callbacks cb;
2211 	u16 nonce_size, tag_size, iv_size, rec_seq_size, salt_size;
2212 	struct crypto_tfm *tfm;
2213 	char *iv, *rec_seq, *key, *salt, *cipher_name;
2214 	size_t keysize;
2215 	int rc = 0;
2216 
2217 	if (!ctx) {
2218 		rc = -EINVAL;
2219 		goto out;
2220 	}
2221 
2222 	if (tx) {
2223 		if (!ctx->priv_ctx_tx) {
2224 			sw_ctx_tx = kzalloc(sizeof(*sw_ctx_tx), GFP_KERNEL);
2225 			if (!sw_ctx_tx) {
2226 				rc = -ENOMEM;
2227 				goto out;
2228 			}
2229 			ctx->priv_ctx_tx = sw_ctx_tx;
2230 		} else {
2231 			sw_ctx_tx =
2232 				(struct tls_sw_context_tx *)ctx->priv_ctx_tx;
2233 		}
2234 	} else {
2235 		if (!ctx->priv_ctx_rx) {
2236 			sw_ctx_rx = kzalloc(sizeof(*sw_ctx_rx), GFP_KERNEL);
2237 			if (!sw_ctx_rx) {
2238 				rc = -ENOMEM;
2239 				goto out;
2240 			}
2241 			ctx->priv_ctx_rx = sw_ctx_rx;
2242 		} else {
2243 			sw_ctx_rx =
2244 				(struct tls_sw_context_rx *)ctx->priv_ctx_rx;
2245 		}
2246 	}
2247 
2248 	if (tx) {
2249 		crypto_init_wait(&sw_ctx_tx->async_wait);
2250 		crypto_info = &ctx->crypto_send.info;
2251 		cctx = &ctx->tx;
2252 		aead = &sw_ctx_tx->aead_send;
2253 		INIT_LIST_HEAD(&sw_ctx_tx->tx_list);
2254 		INIT_DELAYED_WORK(&sw_ctx_tx->tx_work.work, tx_work_handler);
2255 		sw_ctx_tx->tx_work.sk = sk;
2256 	} else {
2257 		crypto_init_wait(&sw_ctx_rx->async_wait);
2258 		crypto_info = &ctx->crypto_recv.info;
2259 		cctx = &ctx->rx;
2260 		skb_queue_head_init(&sw_ctx_rx->rx_list);
2261 		aead = &sw_ctx_rx->aead_recv;
2262 	}
2263 
2264 	switch (crypto_info->cipher_type) {
2265 	case TLS_CIPHER_AES_GCM_128: {
2266 		nonce_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
2267 		tag_size = TLS_CIPHER_AES_GCM_128_TAG_SIZE;
2268 		iv_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
2269 		iv = ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->iv;
2270 		rec_seq_size = TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE;
2271 		rec_seq =
2272 		 ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->rec_seq;
2273 		gcm_128_info =
2274 			(struct tls12_crypto_info_aes_gcm_128 *)crypto_info;
2275 		keysize = TLS_CIPHER_AES_GCM_128_KEY_SIZE;
2276 		key = gcm_128_info->key;
2277 		salt = gcm_128_info->salt;
2278 		salt_size = TLS_CIPHER_AES_GCM_128_SALT_SIZE;
2279 		cipher_name = "gcm(aes)";
2280 		break;
2281 	}
2282 	case TLS_CIPHER_AES_GCM_256: {
2283 		nonce_size = TLS_CIPHER_AES_GCM_256_IV_SIZE;
2284 		tag_size = TLS_CIPHER_AES_GCM_256_TAG_SIZE;
2285 		iv_size = TLS_CIPHER_AES_GCM_256_IV_SIZE;
2286 		iv = ((struct tls12_crypto_info_aes_gcm_256 *)crypto_info)->iv;
2287 		rec_seq_size = TLS_CIPHER_AES_GCM_256_REC_SEQ_SIZE;
2288 		rec_seq =
2289 		 ((struct tls12_crypto_info_aes_gcm_256 *)crypto_info)->rec_seq;
2290 		gcm_256_info =
2291 			(struct tls12_crypto_info_aes_gcm_256 *)crypto_info;
2292 		keysize = TLS_CIPHER_AES_GCM_256_KEY_SIZE;
2293 		key = gcm_256_info->key;
2294 		salt = gcm_256_info->salt;
2295 		salt_size = TLS_CIPHER_AES_GCM_256_SALT_SIZE;
2296 		cipher_name = "gcm(aes)";
2297 		break;
2298 	}
2299 	case TLS_CIPHER_AES_CCM_128: {
2300 		nonce_size = TLS_CIPHER_AES_CCM_128_IV_SIZE;
2301 		tag_size = TLS_CIPHER_AES_CCM_128_TAG_SIZE;
2302 		iv_size = TLS_CIPHER_AES_CCM_128_IV_SIZE;
2303 		iv = ((struct tls12_crypto_info_aes_ccm_128 *)crypto_info)->iv;
2304 		rec_seq_size = TLS_CIPHER_AES_CCM_128_REC_SEQ_SIZE;
2305 		rec_seq =
2306 		((struct tls12_crypto_info_aes_ccm_128 *)crypto_info)->rec_seq;
2307 		ccm_128_info =
2308 		(struct tls12_crypto_info_aes_ccm_128 *)crypto_info;
2309 		keysize = TLS_CIPHER_AES_CCM_128_KEY_SIZE;
2310 		key = ccm_128_info->key;
2311 		salt = ccm_128_info->salt;
2312 		salt_size = TLS_CIPHER_AES_CCM_128_SALT_SIZE;
2313 		cipher_name = "ccm(aes)";
2314 		break;
2315 	}
2316 	default:
2317 		rc = -EINVAL;
2318 		goto free_priv;
2319 	}
2320 
2321 	/* Sanity-check the sizes for stack allocations. */
2322 	if (iv_size > MAX_IV_SIZE || nonce_size > MAX_IV_SIZE ||
2323 	    rec_seq_size > TLS_MAX_REC_SEQ_SIZE) {
2324 		rc = -EINVAL;
2325 		goto free_priv;
2326 	}
2327 
2328 	if (crypto_info->version == TLS_1_3_VERSION) {
2329 		nonce_size = 0;
2330 		prot->aad_size = TLS_HEADER_SIZE;
2331 		prot->tail_size = 1;
2332 	} else {
2333 		prot->aad_size = TLS_AAD_SPACE_SIZE;
2334 		prot->tail_size = 0;
2335 	}
2336 
2337 	prot->version = crypto_info->version;
2338 	prot->cipher_type = crypto_info->cipher_type;
2339 	prot->prepend_size = TLS_HEADER_SIZE + nonce_size;
2340 	prot->tag_size = tag_size;
2341 	prot->overhead_size = prot->prepend_size +
2342 			      prot->tag_size + prot->tail_size;
2343 	prot->iv_size = iv_size;
2344 	prot->salt_size = salt_size;
2345 	cctx->iv = kmalloc(iv_size + salt_size, GFP_KERNEL);
2346 	if (!cctx->iv) {
2347 		rc = -ENOMEM;
2348 		goto free_priv;
2349 	}
2350 	/* Note: 128 & 256 bit salt are the same size */
2351 	prot->rec_seq_size = rec_seq_size;
2352 	memcpy(cctx->iv, salt, salt_size);
2353 	memcpy(cctx->iv + salt_size, iv, iv_size);
2354 	cctx->rec_seq = kmemdup(rec_seq, rec_seq_size, GFP_KERNEL);
2355 	if (!cctx->rec_seq) {
2356 		rc = -ENOMEM;
2357 		goto free_iv;
2358 	}
2359 
2360 	if (!*aead) {
2361 		*aead = crypto_alloc_aead(cipher_name, 0, 0);
2362 		if (IS_ERR(*aead)) {
2363 			rc = PTR_ERR(*aead);
2364 			*aead = NULL;
2365 			goto free_rec_seq;
2366 		}
2367 	}
2368 
2369 	ctx->push_pending_record = tls_sw_push_pending_record;
2370 
2371 	rc = crypto_aead_setkey(*aead, key, keysize);
2372 
2373 	if (rc)
2374 		goto free_aead;
2375 
2376 	rc = crypto_aead_setauthsize(*aead, prot->tag_size);
2377 	if (rc)
2378 		goto free_aead;
2379 
2380 	if (sw_ctx_rx) {
2381 		tfm = crypto_aead_tfm(sw_ctx_rx->aead_recv);
2382 
2383 		if (crypto_info->version == TLS_1_3_VERSION)
2384 			sw_ctx_rx->async_capable = 0;
2385 		else
2386 			sw_ctx_rx->async_capable =
2387 				!!(tfm->__crt_alg->cra_flags &
2388 				   CRYPTO_ALG_ASYNC);
2389 
2390 		/* Set up strparser */
2391 		memset(&cb, 0, sizeof(cb));
2392 		cb.rcv_msg = tls_queue;
2393 		cb.parse_msg = tls_read_size;
2394 
2395 		strp_init(&sw_ctx_rx->strp, sk, &cb);
2396 	}
2397 
2398 	goto out;
2399 
2400 free_aead:
2401 	crypto_free_aead(*aead);
2402 	*aead = NULL;
2403 free_rec_seq:
2404 	kfree(cctx->rec_seq);
2405 	cctx->rec_seq = NULL;
2406 free_iv:
2407 	kfree(cctx->iv);
2408 	cctx->iv = NULL;
2409 free_priv:
2410 	if (tx) {
2411 		kfree(ctx->priv_ctx_tx);
2412 		ctx->priv_ctx_tx = NULL;
2413 	} else {
2414 		kfree(ctx->priv_ctx_rx);
2415 		ctx->priv_ctx_rx = NULL;
2416 	}
2417 out:
2418 	return rc;
2419 }
2420