1/* Copyright (c) 2018, Mellanox Technologies All rights reserved.
2 *
3 * This software is available to you under a choice of one of two
4 * licenses. You may choose to be licensed under the terms of the GNU
5 * General Public License (GPL) Version 2, available from the file
6 * COPYING in the main directory of this source tree, or the
7 * OpenIB.org BSD license below:
8 *
9 * Redistribution and use in source and binary forms, with or
10 * without modification, are permitted provided that the following
11 * conditions are met:
12 *
13 * - Redistributions of source code must retain the above
14 * copyright notice, this list of conditions and the following
15 * disclaimer.
16 *
17 * - Redistributions in binary form must reproduce the above
18 * copyright notice, this list of conditions and the following
19 * disclaimer in the documentation and/or other materials
20 * provided with the distribution.
21 *
22 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
23 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
24 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
25 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
26 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
27 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
28 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
29 * SOFTWARE.
30 */
31
32#include <crypto/aead.h>
33#include <linux/highmem.h>
34#include <linux/module.h>
35#include <linux/netdevice.h>
36#include <net/dst.h>
37#include <net/inet_connection_sock.h>
38#include <net/tcp.h>
39#include <net/tls.h>
40
41#include "tls.h"
42#include "trace.h"
43
44/* device_offload_lock is used to synchronize tls_dev_add
45 * against NETDEV_DOWN notifications.
46 */
47static DECLARE_RWSEM(device_offload_lock);
48
49static struct workqueue_struct *destruct_wq __read_mostly;
50
51static LIST_HEAD(tls_device_list);
52static LIST_HEAD(tls_device_down_list);
53static DEFINE_SPINLOCK(tls_device_lock);
54
55static struct page *dummy_page;
56
57static void tls_device_free_ctx(struct tls_context *ctx)
58{
59 if (ctx->tx_conf == TLS_HW)
60 kfree(objp: tls_offload_ctx_tx(tls_ctx: ctx));
61
62 if (ctx->rx_conf == TLS_HW)
63 kfree(objp: tls_offload_ctx_rx(tls_ctx: ctx));
64
65 tls_ctx_free(NULL, ctx);
66}
67
68static void tls_device_tx_del_task(struct work_struct *work)
69{
70 struct tls_offload_context_tx *offload_ctx =
71 container_of(work, struct tls_offload_context_tx, destruct_work);
72 struct tls_context *ctx = offload_ctx->ctx;
73 struct net_device *netdev;
74
75 /* Safe, because this is the destroy flow, refcount is 0, so
76 * tls_device_down can't store this field in parallel.
77 */
78 netdev = rcu_dereference_protected(ctx->netdev,
79 !refcount_read(&ctx->refcount));
80
81 netdev->tlsdev_ops->tls_dev_del(netdev, ctx, TLS_OFFLOAD_CTX_DIR_TX);
82 dev_put(dev: netdev);
83 ctx->netdev = NULL;
84 tls_device_free_ctx(ctx);
85}
86
87static void tls_device_queue_ctx_destruction(struct tls_context *ctx)
88{
89 struct net_device *netdev;
90 unsigned long flags;
91 bool async_cleanup;
92
93 spin_lock_irqsave(&tls_device_lock, flags);
94 if (unlikely(!refcount_dec_and_test(&ctx->refcount))) {
95 spin_unlock_irqrestore(lock: &tls_device_lock, flags);
96 return;
97 }
98
99 list_del(entry: &ctx->list); /* Remove from tls_device_list / tls_device_down_list */
100
101 /* Safe, because this is the destroy flow, refcount is 0, so
102 * tls_device_down can't store this field in parallel.
103 */
104 netdev = rcu_dereference_protected(ctx->netdev,
105 !refcount_read(&ctx->refcount));
106
107 async_cleanup = netdev && ctx->tx_conf == TLS_HW;
108 if (async_cleanup) {
109 struct tls_offload_context_tx *offload_ctx = tls_offload_ctx_tx(tls_ctx: ctx);
110
111 /* queue_work inside the spinlock
112 * to make sure tls_device_down waits for that work.
113 */
114 queue_work(wq: destruct_wq, work: &offload_ctx->destruct_work);
115 }
116 spin_unlock_irqrestore(lock: &tls_device_lock, flags);
117
118 if (!async_cleanup)
119 tls_device_free_ctx(ctx);
120}
121
122/* We assume that the socket is already connected */
123static struct net_device *get_netdev_for_sock(struct sock *sk)
124{
125 struct dst_entry *dst = sk_dst_get(sk);
126 struct net_device *netdev = NULL;
127
128 if (likely(dst)) {
129 netdev = netdev_sk_get_lowest_dev(dev: dst->dev, sk);
130 dev_hold(dev: netdev);
131 }
132
133 dst_release(dst);
134
135 return netdev;
136}
137
138static void destroy_record(struct tls_record_info *record)
139{
140 int i;
141
142 for (i = 0; i < record->num_frags; i++)
143 __skb_frag_unref(frag: &record->frags[i], recycle: false);
144 kfree(objp: record);
145}
146
147static void delete_all_records(struct tls_offload_context_tx *offload_ctx)
148{
149 struct tls_record_info *info, *temp;
150
151 list_for_each_entry_safe(info, temp, &offload_ctx->records_list, list) {
152 list_del(entry: &info->list);
153 destroy_record(record: info);
154 }
155
156 offload_ctx->retransmit_hint = NULL;
157}
158
159static void tls_icsk_clean_acked(struct sock *sk, u32 acked_seq)
160{
161 struct tls_context *tls_ctx = tls_get_ctx(sk);
162 struct tls_record_info *info, *temp;
163 struct tls_offload_context_tx *ctx;
164 u64 deleted_records = 0;
165 unsigned long flags;
166
167 if (!tls_ctx)
168 return;
169
170 ctx = tls_offload_ctx_tx(tls_ctx);
171
172 spin_lock_irqsave(&ctx->lock, flags);
173 info = ctx->retransmit_hint;
174 if (info && !before(seq1: acked_seq, seq2: info->end_seq))
175 ctx->retransmit_hint = NULL;
176
177 list_for_each_entry_safe(info, temp, &ctx->records_list, list) {
178 if (before(seq1: acked_seq, seq2: info->end_seq))
179 break;
180 list_del(entry: &info->list);
181
182 destroy_record(record: info);
183 deleted_records++;
184 }
185
186 ctx->unacked_record_sn += deleted_records;
187 spin_unlock_irqrestore(lock: &ctx->lock, flags);
188}
189
190/* At this point, there should be no references on this
191 * socket and no in-flight SKBs associated with this
192 * socket, so it is safe to free all the resources.
193 */
194void tls_device_sk_destruct(struct sock *sk)
195{
196 struct tls_context *tls_ctx = tls_get_ctx(sk);
197 struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
198
199 tls_ctx->sk_destruct(sk);
200
201 if (tls_ctx->tx_conf == TLS_HW) {
202 if (ctx->open_record)
203 destroy_record(record: ctx->open_record);
204 delete_all_records(offload_ctx: ctx);
205 crypto_free_aead(tfm: ctx->aead_send);
206 clean_acked_data_disable(icsk: inet_csk(sk));
207 }
208
209 tls_device_queue_ctx_destruction(ctx: tls_ctx);
210}
211EXPORT_SYMBOL_GPL(tls_device_sk_destruct);
212
213void tls_device_free_resources_tx(struct sock *sk)
214{
215 struct tls_context *tls_ctx = tls_get_ctx(sk);
216
217 tls_free_partial_record(sk, ctx: tls_ctx);
218}
219
220void tls_offload_tx_resync_request(struct sock *sk, u32 got_seq, u32 exp_seq)
221{
222 struct tls_context *tls_ctx = tls_get_ctx(sk);
223
224 trace_tls_device_tx_resync_req(sk, tcp_seq: got_seq, exp_tcp_seq: exp_seq);
225 WARN_ON(test_and_set_bit(TLS_TX_SYNC_SCHED, &tls_ctx->flags));
226}
227EXPORT_SYMBOL_GPL(tls_offload_tx_resync_request);
228
229static void tls_device_resync_tx(struct sock *sk, struct tls_context *tls_ctx,
230 u32 seq)
231{
232 struct net_device *netdev;
233 struct sk_buff *skb;
234 int err = 0;
235 u8 *rcd_sn;
236
237 skb = tcp_write_queue_tail(sk);
238 if (skb)
239 TCP_SKB_CB(skb)->eor = 1;
240
241 rcd_sn = tls_ctx->tx.rec_seq;
242
243 trace_tls_device_tx_resync_send(sk, tcp_seq: seq, rec_no: rcd_sn);
244 down_read(sem: &device_offload_lock);
245 netdev = rcu_dereference_protected(tls_ctx->netdev,
246 lockdep_is_held(&device_offload_lock));
247 if (netdev)
248 err = netdev->tlsdev_ops->tls_dev_resync(netdev, sk, seq,
249 rcd_sn,
250 TLS_OFFLOAD_CTX_DIR_TX);
251 up_read(sem: &device_offload_lock);
252 if (err)
253 return;
254
255 clear_bit_unlock(nr: TLS_TX_SYNC_SCHED, addr: &tls_ctx->flags);
256}
257
258static void tls_append_frag(struct tls_record_info *record,
259 struct page_frag *pfrag,
260 int size)
261{
262 skb_frag_t *frag;
263
264 frag = &record->frags[record->num_frags - 1];
265 if (skb_frag_page(frag) == pfrag->page &&
266 skb_frag_off(frag) + skb_frag_size(frag) == pfrag->offset) {
267 skb_frag_size_add(frag, delta: size);
268 } else {
269 ++frag;
270 skb_frag_fill_page_desc(frag, page: pfrag->page, off: pfrag->offset,
271 size);
272 ++record->num_frags;
273 get_page(page: pfrag->page);
274 }
275
276 pfrag->offset += size;
277 record->len += size;
278}
279
280static int tls_push_record(struct sock *sk,
281 struct tls_context *ctx,
282 struct tls_offload_context_tx *offload_ctx,
283 struct tls_record_info *record,
284 int flags)
285{
286 struct tls_prot_info *prot = &ctx->prot_info;
287 struct tcp_sock *tp = tcp_sk(sk);
288 skb_frag_t *frag;
289 int i;
290
291 record->end_seq = tp->write_seq + record->len;
292 list_add_tail_rcu(new: &record->list, head: &offload_ctx->records_list);
293 offload_ctx->open_record = NULL;
294
295 if (test_bit(TLS_TX_SYNC_SCHED, &ctx->flags))
296 tls_device_resync_tx(sk, tls_ctx: ctx, seq: tp->write_seq);
297
298 tls_advance_record_sn(sk, prot, ctx: &ctx->tx);
299
300 for (i = 0; i < record->num_frags; i++) {
301 frag = &record->frags[i];
302 sg_unmark_end(sg: &offload_ctx->sg_tx_data[i]);
303 sg_set_page(sg: &offload_ctx->sg_tx_data[i], page: skb_frag_page(frag),
304 len: skb_frag_size(frag), offset: skb_frag_off(frag));
305 sk_mem_charge(sk, size: skb_frag_size(frag));
306 get_page(page: skb_frag_page(frag));
307 }
308 sg_mark_end(sg: &offload_ctx->sg_tx_data[record->num_frags - 1]);
309
310 /* all ready, send */
311 return tls_push_sg(sk, ctx, sg: offload_ctx->sg_tx_data, first_offset: 0, flags);
312}
313
314static void tls_device_record_close(struct sock *sk,
315 struct tls_context *ctx,
316 struct tls_record_info *record,
317 struct page_frag *pfrag,
318 unsigned char record_type)
319{
320 struct tls_prot_info *prot = &ctx->prot_info;
321 struct page_frag dummy_tag_frag;
322
323 /* append tag
324 * device will fill in the tag, we just need to append a placeholder
325 * use socket memory to improve coalescing (re-using a single buffer
326 * increases frag count)
327 * if we can't allocate memory now use the dummy page
328 */
329 if (unlikely(pfrag->size - pfrag->offset < prot->tag_size) &&
330 !skb_page_frag_refill(sz: prot->tag_size, pfrag, prio: sk->sk_allocation)) {
331 dummy_tag_frag.page = dummy_page;
332 dummy_tag_frag.offset = 0;
333 pfrag = &dummy_tag_frag;
334 }
335 tls_append_frag(record, pfrag, size: prot->tag_size);
336
337 /* fill prepend */
338 tls_fill_prepend(ctx, buf: skb_frag_address(frag: &record->frags[0]),
339 plaintext_len: record->len - prot->overhead_size,
340 record_type);
341}
342
343static int tls_create_new_record(struct tls_offload_context_tx *offload_ctx,
344 struct page_frag *pfrag,
345 size_t prepend_size)
346{
347 struct tls_record_info *record;
348 skb_frag_t *frag;
349
350 record = kmalloc(size: sizeof(*record), GFP_KERNEL);
351 if (!record)
352 return -ENOMEM;
353
354 frag = &record->frags[0];
355 skb_frag_fill_page_desc(frag, page: pfrag->page, off: pfrag->offset,
356 size: prepend_size);
357
358 get_page(page: pfrag->page);
359 pfrag->offset += prepend_size;
360
361 record->num_frags = 1;
362 record->len = prepend_size;
363 offload_ctx->open_record = record;
364 return 0;
365}
366
367static int tls_do_allocation(struct sock *sk,
368 struct tls_offload_context_tx *offload_ctx,
369 struct page_frag *pfrag,
370 size_t prepend_size)
371{
372 int ret;
373
374 if (!offload_ctx->open_record) {
375 if (unlikely(!skb_page_frag_refill(prepend_size, pfrag,
376 sk->sk_allocation))) {
377 READ_ONCE(sk->sk_prot)->enter_memory_pressure(sk);
378 sk_stream_moderate_sndbuf(sk);
379 return -ENOMEM;
380 }
381
382 ret = tls_create_new_record(offload_ctx, pfrag, prepend_size);
383 if (ret)
384 return ret;
385
386 if (pfrag->size > pfrag->offset)
387 return 0;
388 }
389
390 if (!sk_page_frag_refill(sk, pfrag))
391 return -ENOMEM;
392
393 return 0;
394}
395
396static int tls_device_copy_data(void *addr, size_t bytes, struct iov_iter *i)
397{
398 size_t pre_copy, nocache;
399
400 pre_copy = ~((unsigned long)addr - 1) & (SMP_CACHE_BYTES - 1);
401 if (pre_copy) {
402 pre_copy = min(pre_copy, bytes);
403 if (copy_from_iter(addr, bytes: pre_copy, i) != pre_copy)
404 return -EFAULT;
405 bytes -= pre_copy;
406 addr += pre_copy;
407 }
408
409 nocache = round_down(bytes, SMP_CACHE_BYTES);
410 if (copy_from_iter_nocache(addr, bytes: nocache, i) != nocache)
411 return -EFAULT;
412 bytes -= nocache;
413 addr += nocache;
414
415 if (bytes && copy_from_iter(addr, bytes, i) != bytes)
416 return -EFAULT;
417
418 return 0;
419}
420
421static int tls_push_data(struct sock *sk,
422 struct iov_iter *iter,
423 size_t size, int flags,
424 unsigned char record_type)
425{
426 struct tls_context *tls_ctx = tls_get_ctx(sk);
427 struct tls_prot_info *prot = &tls_ctx->prot_info;
428 struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
429 struct tls_record_info *record;
430 int tls_push_record_flags;
431 struct page_frag *pfrag;
432 size_t orig_size = size;
433 u32 max_open_record_len;
434 bool more = false;
435 bool done = false;
436 int copy, rc = 0;
437 long timeo;
438
439 if (flags &
440 ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL |
441 MSG_SPLICE_PAGES | MSG_EOR))
442 return -EOPNOTSUPP;
443
444 if ((flags & (MSG_MORE | MSG_EOR)) == (MSG_MORE | MSG_EOR))
445 return -EINVAL;
446
447 if (unlikely(sk->sk_err))
448 return -sk->sk_err;
449
450 flags |= MSG_SENDPAGE_DECRYPTED;
451 tls_push_record_flags = flags | MSG_MORE;
452
453 timeo = sock_sndtimeo(sk, noblock: flags & MSG_DONTWAIT);
454 if (tls_is_partially_sent_record(ctx: tls_ctx)) {
455 rc = tls_push_partial_record(sk, ctx: tls_ctx, flags);
456 if (rc < 0)
457 return rc;
458 }
459
460 pfrag = sk_page_frag(sk);
461
462 /* TLS_HEADER_SIZE is not counted as part of the TLS record, and
463 * we need to leave room for an authentication tag.
464 */
465 max_open_record_len = TLS_MAX_PAYLOAD_SIZE +
466 prot->prepend_size;
467 do {
468 rc = tls_do_allocation(sk, offload_ctx: ctx, pfrag, prepend_size: prot->prepend_size);
469 if (unlikely(rc)) {
470 rc = sk_stream_wait_memory(sk, timeo_p: &timeo);
471 if (!rc)
472 continue;
473
474 record = ctx->open_record;
475 if (!record)
476 break;
477handle_error:
478 if (record_type != TLS_RECORD_TYPE_DATA) {
479 /* avoid sending partial
480 * record with type !=
481 * application_data
482 */
483 size = orig_size;
484 destroy_record(record);
485 ctx->open_record = NULL;
486 } else if (record->len > prot->prepend_size) {
487 goto last_record;
488 }
489
490 break;
491 }
492
493 record = ctx->open_record;
494
495 copy = min_t(size_t, size, max_open_record_len - record->len);
496 if (copy && (flags & MSG_SPLICE_PAGES)) {
497 struct page_frag zc_pfrag;
498 struct page **pages = &zc_pfrag.page;
499 size_t off;
500
501 rc = iov_iter_extract_pages(i: iter, pages: &pages,
502 maxsize: copy, maxpages: 1, extraction_flags: 0, offset0: &off);
503 if (rc <= 0) {
504 if (rc == 0)
505 rc = -EIO;
506 goto handle_error;
507 }
508 copy = rc;
509
510 if (WARN_ON_ONCE(!sendpage_ok(zc_pfrag.page))) {
511 iov_iter_revert(i: iter, bytes: copy);
512 rc = -EIO;
513 goto handle_error;
514 }
515
516 zc_pfrag.offset = off;
517 zc_pfrag.size = copy;
518 tls_append_frag(record, pfrag: &zc_pfrag, size: copy);
519 } else if (copy) {
520 copy = min_t(size_t, copy, pfrag->size - pfrag->offset);
521
522 rc = tls_device_copy_data(page_address(pfrag->page) +
523 pfrag->offset, bytes: copy,
524 i: iter);
525 if (rc)
526 goto handle_error;
527 tls_append_frag(record, pfrag, size: copy);
528 }
529
530 size -= copy;
531 if (!size) {
532last_record:
533 tls_push_record_flags = flags;
534 if (flags & MSG_MORE) {
535 more = true;
536 break;
537 }
538
539 done = true;
540 }
541
542 if (done || record->len >= max_open_record_len ||
543 (record->num_frags >= MAX_SKB_FRAGS - 1)) {
544 tls_device_record_close(sk, ctx: tls_ctx, record,
545 pfrag, record_type);
546
547 rc = tls_push_record(sk,
548 ctx: tls_ctx,
549 offload_ctx: ctx,
550 record,
551 flags: tls_push_record_flags);
552 if (rc < 0)
553 break;
554 }
555 } while (!done);
556
557 tls_ctx->pending_open_record_frags = more;
558
559 if (orig_size - size > 0)
560 rc = orig_size - size;
561
562 return rc;
563}
564
565int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
566{
567 unsigned char record_type = TLS_RECORD_TYPE_DATA;
568 struct tls_context *tls_ctx = tls_get_ctx(sk);
569 int rc;
570
571 if (!tls_ctx->zerocopy_sendfile)
572 msg->msg_flags &= ~MSG_SPLICE_PAGES;
573
574 mutex_lock(&tls_ctx->tx_lock);
575 lock_sock(sk);
576
577 if (unlikely(msg->msg_controllen)) {
578 rc = tls_process_cmsg(sk, msg, record_type: &record_type);
579 if (rc)
580 goto out;
581 }
582
583 rc = tls_push_data(sk, iter: &msg->msg_iter, size, flags: msg->msg_flags,
584 record_type);
585
586out:
587 release_sock(sk);
588 mutex_unlock(lock: &tls_ctx->tx_lock);
589 return rc;
590}
591
592void tls_device_splice_eof(struct socket *sock)
593{
594 struct sock *sk = sock->sk;
595 struct tls_context *tls_ctx = tls_get_ctx(sk);
596 struct iov_iter iter = {};
597
598 if (!tls_is_partially_sent_record(ctx: tls_ctx))
599 return;
600
601 mutex_lock(&tls_ctx->tx_lock);
602 lock_sock(sk);
603
604 if (tls_is_partially_sent_record(ctx: tls_ctx)) {
605 iov_iter_bvec(i: &iter, ITER_SOURCE, NULL, nr_segs: 0, count: 0);
606 tls_push_data(sk, iter: &iter, size: 0, flags: 0, record_type: TLS_RECORD_TYPE_DATA);
607 }
608
609 release_sock(sk);
610 mutex_unlock(lock: &tls_ctx->tx_lock);
611}
612
613struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context,
614 u32 seq, u64 *p_record_sn)
615{
616 u64 record_sn = context->hint_record_sn;
617 struct tls_record_info *info, *last;
618
619 info = context->retransmit_hint;
620 if (!info ||
621 before(seq1: seq, seq2: info->end_seq - info->len)) {
622 /* if retransmit_hint is irrelevant start
623 * from the beginning of the list
624 */
625 info = list_first_entry_or_null(&context->records_list,
626 struct tls_record_info, list);
627 if (!info)
628 return NULL;
629 /* send the start_marker record if seq number is before the
630 * tls offload start marker sequence number. This record is
631 * required to handle TCP packets which are before TLS offload
632 * started.
633 * And if it's not start marker, look if this seq number
634 * belongs to the list.
635 */
636 if (likely(!tls_record_is_start_marker(info))) {
637 /* we have the first record, get the last record to see
638 * if this seq number belongs to the list.
639 */
640 last = list_last_entry(&context->records_list,
641 struct tls_record_info, list);
642
643 if (!between(seq1: seq, seq2: tls_record_start_seq(rec: info),
644 seq3: last->end_seq))
645 return NULL;
646 }
647 record_sn = context->unacked_record_sn;
648 }
649
650 /* We just need the _rcu for the READ_ONCE() */
651 rcu_read_lock();
652 list_for_each_entry_from_rcu(info, &context->records_list, list) {
653 if (before(seq1: seq, seq2: info->end_seq)) {
654 if (!context->retransmit_hint ||
655 after(info->end_seq,
656 context->retransmit_hint->end_seq)) {
657 context->hint_record_sn = record_sn;
658 context->retransmit_hint = info;
659 }
660 *p_record_sn = record_sn;
661 goto exit_rcu_unlock;
662 }
663 record_sn++;
664 }
665 info = NULL;
666
667exit_rcu_unlock:
668 rcu_read_unlock();
669 return info;
670}
671EXPORT_SYMBOL(tls_get_record);
672
673static int tls_device_push_pending_record(struct sock *sk, int flags)
674{
675 struct iov_iter iter;
676
677 iov_iter_kvec(i: &iter, ITER_SOURCE, NULL, nr_segs: 0, count: 0);
678 return tls_push_data(sk, iter: &iter, size: 0, flags, record_type: TLS_RECORD_TYPE_DATA);
679}
680
681void tls_device_write_space(struct sock *sk, struct tls_context *ctx)
682{
683 if (tls_is_partially_sent_record(ctx)) {
684 gfp_t sk_allocation = sk->sk_allocation;
685
686 WARN_ON_ONCE(sk->sk_write_pending);
687
688 sk->sk_allocation = GFP_ATOMIC;
689 tls_push_partial_record(sk, ctx,
690 MSG_DONTWAIT | MSG_NOSIGNAL |
691 MSG_SENDPAGE_DECRYPTED);
692 sk->sk_allocation = sk_allocation;
693 }
694}
695
696static void tls_device_resync_rx(struct tls_context *tls_ctx,
697 struct sock *sk, u32 seq, u8 *rcd_sn)
698{
699 struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
700 struct net_device *netdev;
701
702 trace_tls_device_rx_resync_send(sk, tcp_seq: seq, rec_no: rcd_sn, sync_type: rx_ctx->resync_type);
703 rcu_read_lock();
704 netdev = rcu_dereference(tls_ctx->netdev);
705 if (netdev)
706 netdev->tlsdev_ops->tls_dev_resync(netdev, sk, seq, rcd_sn,
707 TLS_OFFLOAD_CTX_DIR_RX);
708 rcu_read_unlock();
709 TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSRXDEVICERESYNC);
710}
711
712static bool
713tls_device_rx_resync_async(struct tls_offload_resync_async *resync_async,
714 s64 resync_req, u32 *seq, u16 *rcd_delta)
715{
716 u32 is_async = resync_req & RESYNC_REQ_ASYNC;
717 u32 req_seq = resync_req >> 32;
718 u32 req_end = req_seq + ((resync_req >> 16) & 0xffff);
719 u16 i;
720
721 *rcd_delta = 0;
722
723 if (is_async) {
724 /* shouldn't get to wraparound:
725 * too long in async stage, something bad happened
726 */
727 if (WARN_ON_ONCE(resync_async->rcd_delta == USHRT_MAX))
728 return false;
729
730 /* asynchronous stage: log all headers seq such that
731 * req_seq <= seq <= end_seq, and wait for real resync request
732 */
733 if (before(seq1: *seq, seq2: req_seq))
734 return false;
735 if (!after(*seq, req_end) &&
736 resync_async->loglen < TLS_DEVICE_RESYNC_ASYNC_LOGMAX)
737 resync_async->log[resync_async->loglen++] = *seq;
738
739 resync_async->rcd_delta++;
740
741 return false;
742 }
743
744 /* synchronous stage: check against the logged entries and
745 * proceed to check the next entries if no match was found
746 */
747 for (i = 0; i < resync_async->loglen; i++)
748 if (req_seq == resync_async->log[i] &&
749 atomic64_try_cmpxchg(v: &resync_async->req, old: &resync_req, new: 0)) {
750 *rcd_delta = resync_async->rcd_delta - i;
751 *seq = req_seq;
752 resync_async->loglen = 0;
753 resync_async->rcd_delta = 0;
754 return true;
755 }
756
757 resync_async->loglen = 0;
758 resync_async->rcd_delta = 0;
759
760 if (req_seq == *seq &&
761 atomic64_try_cmpxchg(v: &resync_async->req,
762 old: &resync_req, new: 0))
763 return true;
764
765 return false;
766}
767
768void tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq)
769{
770 struct tls_context *tls_ctx = tls_get_ctx(sk);
771 struct tls_offload_context_rx *rx_ctx;
772 u8 rcd_sn[TLS_MAX_REC_SEQ_SIZE];
773 u32 sock_data, is_req_pending;
774 struct tls_prot_info *prot;
775 s64 resync_req;
776 u16 rcd_delta;
777 u32 req_seq;
778
779 if (tls_ctx->rx_conf != TLS_HW)
780 return;
781 if (unlikely(test_bit(TLS_RX_DEV_DEGRADED, &tls_ctx->flags)))
782 return;
783
784 prot = &tls_ctx->prot_info;
785 rx_ctx = tls_offload_ctx_rx(tls_ctx);
786 memcpy(rcd_sn, tls_ctx->rx.rec_seq, prot->rec_seq_size);
787
788 switch (rx_ctx->resync_type) {
789 case TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ:
790 resync_req = atomic64_read(v: &rx_ctx->resync_req);
791 req_seq = resync_req >> 32;
792 seq += TLS_HEADER_SIZE - 1;
793 is_req_pending = resync_req;
794
795 if (likely(!is_req_pending) || req_seq != seq ||
796 !atomic64_try_cmpxchg(v: &rx_ctx->resync_req, old: &resync_req, new: 0))
797 return;
798 break;
799 case TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT:
800 if (likely(!rx_ctx->resync_nh_do_now))
801 return;
802
803 /* head of next rec is already in, note that the sock_inq will
804 * include the currently parsed message when called from parser
805 */
806 sock_data = tcp_inq(sk);
807 if (sock_data > rcd_len) {
808 trace_tls_device_rx_resync_nh_delay(sk, sock_data,
809 rec_len: rcd_len);
810 return;
811 }
812
813 rx_ctx->resync_nh_do_now = 0;
814 seq += rcd_len;
815 tls_bigint_increment(seq: rcd_sn, len: prot->rec_seq_size);
816 break;
817 case TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ_ASYNC:
818 resync_req = atomic64_read(v: &rx_ctx->resync_async->req);
819 is_req_pending = resync_req;
820 if (likely(!is_req_pending))
821 return;
822
823 if (!tls_device_rx_resync_async(resync_async: rx_ctx->resync_async,
824 resync_req, seq: &seq, rcd_delta: &rcd_delta))
825 return;
826 tls_bigint_subtract(seq: rcd_sn, n: rcd_delta);
827 break;
828 }
829
830 tls_device_resync_rx(tls_ctx, sk, seq, rcd_sn);
831}
832
833static void tls_device_core_ctrl_rx_resync(struct tls_context *tls_ctx,
834 struct tls_offload_context_rx *ctx,
835 struct sock *sk, struct sk_buff *skb)
836{
837 struct strp_msg *rxm;
838
839 /* device will request resyncs by itself based on stream scan */
840 if (ctx->resync_type != TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT)
841 return;
842 /* already scheduled */
843 if (ctx->resync_nh_do_now)
844 return;
845 /* seen decrypted fragments since last fully-failed record */
846 if (ctx->resync_nh_reset) {
847 ctx->resync_nh_reset = 0;
848 ctx->resync_nh.decrypted_failed = 1;
849 ctx->resync_nh.decrypted_tgt = TLS_DEVICE_RESYNC_NH_START_IVAL;
850 return;
851 }
852
853 if (++ctx->resync_nh.decrypted_failed <= ctx->resync_nh.decrypted_tgt)
854 return;
855
856 /* doing resync, bump the next target in case it fails */
857 if (ctx->resync_nh.decrypted_tgt < TLS_DEVICE_RESYNC_NH_MAX_IVAL)
858 ctx->resync_nh.decrypted_tgt *= 2;
859 else
860 ctx->resync_nh.decrypted_tgt += TLS_DEVICE_RESYNC_NH_MAX_IVAL;
861
862 rxm = strp_msg(skb);
863
864 /* head of next rec is already in, parser will sync for us */
865 if (tcp_inq(sk) > rxm->full_len) {
866 trace_tls_device_rx_resync_nh_schedule(sk);
867 ctx->resync_nh_do_now = 1;
868 } else {
869 struct tls_prot_info *prot = &tls_ctx->prot_info;
870 u8 rcd_sn[TLS_MAX_REC_SEQ_SIZE];
871
872 memcpy(rcd_sn, tls_ctx->rx.rec_seq, prot->rec_seq_size);
873 tls_bigint_increment(seq: rcd_sn, len: prot->rec_seq_size);
874
875 tls_device_resync_rx(tls_ctx, sk, tcp_sk(sk)->copied_seq,
876 rcd_sn);
877 }
878}
879
880static int
881tls_device_reencrypt(struct sock *sk, struct tls_context *tls_ctx)
882{
883 struct tls_sw_context_rx *sw_ctx = tls_sw_ctx_rx(tls_ctx);
884 const struct tls_cipher_desc *cipher_desc;
885 int err, offset, copy, data_len, pos;
886 struct sk_buff *skb, *skb_iter;
887 struct scatterlist sg[1];
888 struct strp_msg *rxm;
889 char *orig_buf, *buf;
890
891 cipher_desc = get_cipher_desc(cipher_type: tls_ctx->crypto_recv.info.cipher_type);
892 DEBUG_NET_WARN_ON_ONCE(!cipher_desc || !cipher_desc->offloadable);
893
894 rxm = strp_msg(skb: tls_strp_msg(ctx: sw_ctx));
895 orig_buf = kmalloc(size: rxm->full_len + TLS_HEADER_SIZE + cipher_desc->iv,
896 flags: sk->sk_allocation);
897 if (!orig_buf)
898 return -ENOMEM;
899 buf = orig_buf;
900
901 err = tls_strp_msg_cow(ctx: sw_ctx);
902 if (unlikely(err))
903 goto free_buf;
904
905 skb = tls_strp_msg(ctx: sw_ctx);
906 rxm = strp_msg(skb);
907 offset = rxm->offset;
908
909 sg_init_table(sg, 1);
910 sg_set_buf(sg: &sg[0], buf,
911 buflen: rxm->full_len + TLS_HEADER_SIZE + cipher_desc->iv);
912 err = skb_copy_bits(skb, offset, to: buf, TLS_HEADER_SIZE + cipher_desc->iv);
913 if (err)
914 goto free_buf;
915
916 /* We are interested only in the decrypted data not the auth */
917 err = decrypt_skb(sk, sgout: sg);
918 if (err != -EBADMSG)
919 goto free_buf;
920 else
921 err = 0;
922
923 data_len = rxm->full_len - cipher_desc->tag;
924
925 if (skb_pagelen(skb) > offset) {
926 copy = min_t(int, skb_pagelen(skb) - offset, data_len);
927
928 if (skb->decrypted) {
929 err = skb_store_bits(skb, offset, from: buf, len: copy);
930 if (err)
931 goto free_buf;
932 }
933
934 offset += copy;
935 buf += copy;
936 }
937
938 pos = skb_pagelen(skb);
939 skb_walk_frags(skb, skb_iter) {
940 int frag_pos;
941
942 /* Practically all frags must belong to msg if reencrypt
943 * is needed with current strparser and coalescing logic,
944 * but strparser may "get optimized", so let's be safe.
945 */
946 if (pos + skb_iter->len <= offset)
947 goto done_with_frag;
948 if (pos >= data_len + rxm->offset)
949 break;
950
951 frag_pos = offset - pos;
952 copy = min_t(int, skb_iter->len - frag_pos,
953 data_len + rxm->offset - offset);
954
955 if (skb_iter->decrypted) {
956 err = skb_store_bits(skb: skb_iter, offset: frag_pos, from: buf, len: copy);
957 if (err)
958 goto free_buf;
959 }
960
961 offset += copy;
962 buf += copy;
963done_with_frag:
964 pos += skb_iter->len;
965 }
966
967free_buf:
968 kfree(objp: orig_buf);
969 return err;
970}
971
972int tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx)
973{
974 struct tls_offload_context_rx *ctx = tls_offload_ctx_rx(tls_ctx);
975 struct tls_sw_context_rx *sw_ctx = tls_sw_ctx_rx(tls_ctx);
976 struct sk_buff *skb = tls_strp_msg(ctx: sw_ctx);
977 struct strp_msg *rxm = strp_msg(skb);
978 int is_decrypted, is_encrypted;
979
980 if (!tls_strp_msg_mixed_decrypted(ctx: sw_ctx)) {
981 is_decrypted = skb->decrypted;
982 is_encrypted = !is_decrypted;
983 } else {
984 is_decrypted = 0;
985 is_encrypted = 0;
986 }
987
988 trace_tls_device_decrypted(sk, tcp_sk(sk)->copied_seq - rxm->full_len,
989 rec_no: tls_ctx->rx.rec_seq, rec_len: rxm->full_len,
990 encrypted: is_encrypted, decrypted: is_decrypted);
991
992 if (unlikely(test_bit(TLS_RX_DEV_DEGRADED, &tls_ctx->flags))) {
993 if (likely(is_encrypted || is_decrypted))
994 return is_decrypted;
995
996 /* After tls_device_down disables the offload, the next SKB will
997 * likely have initial fragments decrypted, and final ones not
998 * decrypted. We need to reencrypt that single SKB.
999 */
1000 return tls_device_reencrypt(sk, tls_ctx);
1001 }
1002
1003 /* Return immediately if the record is either entirely plaintext or
1004 * entirely ciphertext. Otherwise handle reencrypt partially decrypted
1005 * record.
1006 */
1007 if (is_decrypted) {
1008 ctx->resync_nh_reset = 1;
1009 return is_decrypted;
1010 }
1011 if (is_encrypted) {
1012 tls_device_core_ctrl_rx_resync(tls_ctx, ctx, sk, skb);
1013 return 0;
1014 }
1015
1016 ctx->resync_nh_reset = 1;
1017 return tls_device_reencrypt(sk, tls_ctx);
1018}
1019
1020static void tls_device_attach(struct tls_context *ctx, struct sock *sk,
1021 struct net_device *netdev)
1022{
1023 if (sk->sk_destruct != tls_device_sk_destruct) {
1024 refcount_set(r: &ctx->refcount, n: 1);
1025 dev_hold(dev: netdev);
1026 RCU_INIT_POINTER(ctx->netdev, netdev);
1027 spin_lock_irq(lock: &tls_device_lock);
1028 list_add_tail(new: &ctx->list, head: &tls_device_list);
1029 spin_unlock_irq(lock: &tls_device_lock);
1030
1031 ctx->sk_destruct = sk->sk_destruct;
1032 smp_store_release(&sk->sk_destruct, tls_device_sk_destruct);
1033 }
1034}
1035
1036static struct tls_offload_context_tx *alloc_offload_ctx_tx(struct tls_context *ctx)
1037{
1038 struct tls_offload_context_tx *offload_ctx;
1039 __be64 rcd_sn;
1040
1041 offload_ctx = kzalloc(size: sizeof(*offload_ctx), GFP_KERNEL);
1042 if (!offload_ctx)
1043 return NULL;
1044
1045 INIT_WORK(&offload_ctx->destruct_work, tls_device_tx_del_task);
1046 INIT_LIST_HEAD(list: &offload_ctx->records_list);
1047 spin_lock_init(&offload_ctx->lock);
1048 sg_init_table(offload_ctx->sg_tx_data,
1049 ARRAY_SIZE(offload_ctx->sg_tx_data));
1050
1051 /* start at rec_seq - 1 to account for the start marker record */
1052 memcpy(&rcd_sn, ctx->tx.rec_seq, sizeof(rcd_sn));
1053 offload_ctx->unacked_record_sn = be64_to_cpu(rcd_sn) - 1;
1054
1055 offload_ctx->ctx = ctx;
1056
1057 return offload_ctx;
1058}
1059
1060int tls_set_device_offload(struct sock *sk)
1061{
1062 struct tls_record_info *start_marker_record;
1063 struct tls_offload_context_tx *offload_ctx;
1064 const struct tls_cipher_desc *cipher_desc;
1065 struct tls_crypto_info *crypto_info;
1066 struct tls_prot_info *prot;
1067 struct net_device *netdev;
1068 struct tls_context *ctx;
1069 struct sk_buff *skb;
1070 char *iv, *rec_seq;
1071 int rc;
1072
1073 ctx = tls_get_ctx(sk);
1074 prot = &ctx->prot_info;
1075
1076 if (ctx->priv_ctx_tx)
1077 return -EEXIST;
1078
1079 netdev = get_netdev_for_sock(sk);
1080 if (!netdev) {
1081 pr_err_ratelimited("%s: netdev not found\n", __func__);
1082 return -EINVAL;
1083 }
1084
1085 if (!(netdev->features & NETIF_F_HW_TLS_TX)) {
1086 rc = -EOPNOTSUPP;
1087 goto release_netdev;
1088 }
1089
1090 crypto_info = &ctx->crypto_send.info;
1091 if (crypto_info->version != TLS_1_2_VERSION) {
1092 rc = -EOPNOTSUPP;
1093 goto release_netdev;
1094 }
1095
1096 cipher_desc = get_cipher_desc(cipher_type: crypto_info->cipher_type);
1097 if (!cipher_desc || !cipher_desc->offloadable) {
1098 rc = -EINVAL;
1099 goto release_netdev;
1100 }
1101
1102 rc = init_prot_info(prot, crypto_info, cipher_desc);
1103 if (rc)
1104 goto release_netdev;
1105
1106 iv = crypto_info_iv(crypto_info, cipher_desc);
1107 rec_seq = crypto_info_rec_seq(crypto_info, cipher_desc);
1108
1109 memcpy(ctx->tx.iv + cipher_desc->salt, iv, cipher_desc->iv);
1110 memcpy(ctx->tx.rec_seq, rec_seq, cipher_desc->rec_seq);
1111
1112 start_marker_record = kmalloc(size: sizeof(*start_marker_record), GFP_KERNEL);
1113 if (!start_marker_record) {
1114 rc = -ENOMEM;
1115 goto release_netdev;
1116 }
1117
1118 offload_ctx = alloc_offload_ctx_tx(ctx);
1119 if (!offload_ctx) {
1120 rc = -ENOMEM;
1121 goto free_marker_record;
1122 }
1123
1124 rc = tls_sw_fallback_init(sk, offload_ctx, crypto_info);
1125 if (rc)
1126 goto free_offload_ctx;
1127
1128 start_marker_record->end_seq = tcp_sk(sk)->write_seq;
1129 start_marker_record->len = 0;
1130 start_marker_record->num_frags = 0;
1131 list_add_tail(new: &start_marker_record->list, head: &offload_ctx->records_list);
1132
1133 clean_acked_data_enable(icsk: inet_csk(sk), cad: &tls_icsk_clean_acked);
1134 ctx->push_pending_record = tls_device_push_pending_record;
1135
1136 /* TLS offload is greatly simplified if we don't send
1137 * SKBs where only part of the payload needs to be encrypted.
1138 * So mark the last skb in the write queue as end of record.
1139 */
1140 skb = tcp_write_queue_tail(sk);
1141 if (skb)
1142 TCP_SKB_CB(skb)->eor = 1;
1143
1144 /* Avoid offloading if the device is down
1145 * We don't want to offload new flows after
1146 * the NETDEV_DOWN event
1147 *
1148 * device_offload_lock is taken in tls_devices's NETDEV_DOWN
1149 * handler thus protecting from the device going down before
1150 * ctx was added to tls_device_list.
1151 */
1152 down_read(sem: &device_offload_lock);
1153 if (!(netdev->flags & IFF_UP)) {
1154 rc = -EINVAL;
1155 goto release_lock;
1156 }
1157
1158 ctx->priv_ctx_tx = offload_ctx;
1159 rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_TX,
1160 &ctx->crypto_send.info,
1161 tcp_sk(sk)->write_seq);
1162 trace_tls_device_offload_set(sk, dir: TLS_OFFLOAD_CTX_DIR_TX,
1163 tcp_sk(sk)->write_seq, rec_no: rec_seq, ret: rc);
1164 if (rc)
1165 goto release_lock;
1166
1167 tls_device_attach(ctx, sk, netdev);
1168 up_read(sem: &device_offload_lock);
1169
1170 /* following this assignment tls_is_skb_tx_device_offloaded
1171 * will return true and the context might be accessed
1172 * by the netdev's xmit function.
1173 */
1174 smp_store_release(&sk->sk_validate_xmit_skb, tls_validate_xmit_skb);
1175 dev_put(dev: netdev);
1176
1177 return 0;
1178
1179release_lock:
1180 up_read(sem: &device_offload_lock);
1181 clean_acked_data_disable(icsk: inet_csk(sk));
1182 crypto_free_aead(tfm: offload_ctx->aead_send);
1183free_offload_ctx:
1184 kfree(objp: offload_ctx);
1185 ctx->priv_ctx_tx = NULL;
1186free_marker_record:
1187 kfree(objp: start_marker_record);
1188release_netdev:
1189 dev_put(dev: netdev);
1190 return rc;
1191}
1192
1193int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
1194{
1195 struct tls12_crypto_info_aes_gcm_128 *info;
1196 struct tls_offload_context_rx *context;
1197 struct net_device *netdev;
1198 int rc = 0;
1199
1200 if (ctx->crypto_recv.info.version != TLS_1_2_VERSION)
1201 return -EOPNOTSUPP;
1202
1203 netdev = get_netdev_for_sock(sk);
1204 if (!netdev) {
1205 pr_err_ratelimited("%s: netdev not found\n", __func__);
1206 return -EINVAL;
1207 }
1208
1209 if (!(netdev->features & NETIF_F_HW_TLS_RX)) {
1210 rc = -EOPNOTSUPP;
1211 goto release_netdev;
1212 }
1213
1214 /* Avoid offloading if the device is down
1215 * We don't want to offload new flows after
1216 * the NETDEV_DOWN event
1217 *
1218 * device_offload_lock is taken in tls_devices's NETDEV_DOWN
1219 * handler thus protecting from the device going down before
1220 * ctx was added to tls_device_list.
1221 */
1222 down_read(sem: &device_offload_lock);
1223 if (!(netdev->flags & IFF_UP)) {
1224 rc = -EINVAL;
1225 goto release_lock;
1226 }
1227
1228 context = kzalloc(size: sizeof(*context), GFP_KERNEL);
1229 if (!context) {
1230 rc = -ENOMEM;
1231 goto release_lock;
1232 }
1233 context->resync_nh_reset = 1;
1234
1235 ctx->priv_ctx_rx = context;
1236 rc = tls_set_sw_offload(sk, tx: 0);
1237 if (rc)
1238 goto release_ctx;
1239
1240 rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_RX,
1241 &ctx->crypto_recv.info,
1242 tcp_sk(sk)->copied_seq);
1243 info = (void *)&ctx->crypto_recv.info;
1244 trace_tls_device_offload_set(sk, dir: TLS_OFFLOAD_CTX_DIR_RX,
1245 tcp_sk(sk)->copied_seq, rec_no: info->rec_seq, ret: rc);
1246 if (rc)
1247 goto free_sw_resources;
1248
1249 tls_device_attach(ctx, sk, netdev);
1250 up_read(sem: &device_offload_lock);
1251
1252 dev_put(dev: netdev);
1253
1254 return 0;
1255
1256free_sw_resources:
1257 up_read(sem: &device_offload_lock);
1258 tls_sw_free_resources_rx(sk);
1259 down_read(sem: &device_offload_lock);
1260release_ctx:
1261 ctx->priv_ctx_rx = NULL;
1262release_lock:
1263 up_read(sem: &device_offload_lock);
1264release_netdev:
1265 dev_put(dev: netdev);
1266 return rc;
1267}
1268
1269void tls_device_offload_cleanup_rx(struct sock *sk)
1270{
1271 struct tls_context *tls_ctx = tls_get_ctx(sk);
1272 struct net_device *netdev;
1273
1274 down_read(sem: &device_offload_lock);
1275 netdev = rcu_dereference_protected(tls_ctx->netdev,
1276 lockdep_is_held(&device_offload_lock));
1277 if (!netdev)
1278 goto out;
1279
1280 netdev->tlsdev_ops->tls_dev_del(netdev, tls_ctx,
1281 TLS_OFFLOAD_CTX_DIR_RX);
1282
1283 if (tls_ctx->tx_conf != TLS_HW) {
1284 dev_put(dev: netdev);
1285 rcu_assign_pointer(tls_ctx->netdev, NULL);
1286 } else {
1287 set_bit(nr: TLS_RX_DEV_CLOSED, addr: &tls_ctx->flags);
1288 }
1289out:
1290 up_read(sem: &device_offload_lock);
1291 tls_sw_release_resources_rx(sk);
1292}
1293
1294static int tls_device_down(struct net_device *netdev)
1295{
1296 struct tls_context *ctx, *tmp;
1297 unsigned long flags;
1298 LIST_HEAD(list);
1299
1300 /* Request a write lock to block new offload attempts */
1301 down_write(sem: &device_offload_lock);
1302
1303 spin_lock_irqsave(&tls_device_lock, flags);
1304 list_for_each_entry_safe(ctx, tmp, &tls_device_list, list) {
1305 struct net_device *ctx_netdev =
1306 rcu_dereference_protected(ctx->netdev,
1307 lockdep_is_held(&device_offload_lock));
1308
1309 if (ctx_netdev != netdev ||
1310 !refcount_inc_not_zero(r: &ctx->refcount))
1311 continue;
1312
1313 list_move(list: &ctx->list, head: &list);
1314 }
1315 spin_unlock_irqrestore(lock: &tls_device_lock, flags);
1316
1317 list_for_each_entry_safe(ctx, tmp, &list, list) {
1318 /* Stop offloaded TX and switch to the fallback.
1319 * tls_is_skb_tx_device_offloaded will return false.
1320 */
1321 WRITE_ONCE(ctx->sk->sk_validate_xmit_skb, tls_validate_xmit_skb_sw);
1322
1323 /* Stop the RX and TX resync.
1324 * tls_dev_resync must not be called after tls_dev_del.
1325 */
1326 rcu_assign_pointer(ctx->netdev, NULL);
1327
1328 /* Start skipping the RX resync logic completely. */
1329 set_bit(nr: TLS_RX_DEV_DEGRADED, addr: &ctx->flags);
1330
1331 /* Sync with inflight packets. After this point:
1332 * TX: no non-encrypted packets will be passed to the driver.
1333 * RX: resync requests from the driver will be ignored.
1334 */
1335 synchronize_net();
1336
1337 /* Release the offload context on the driver side. */
1338 if (ctx->tx_conf == TLS_HW)
1339 netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
1340 TLS_OFFLOAD_CTX_DIR_TX);
1341 if (ctx->rx_conf == TLS_HW &&
1342 !test_bit(TLS_RX_DEV_CLOSED, &ctx->flags))
1343 netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
1344 TLS_OFFLOAD_CTX_DIR_RX);
1345
1346 dev_put(dev: netdev);
1347
1348 /* Move the context to a separate list for two reasons:
1349 * 1. When the context is deallocated, list_del is called.
1350 * 2. It's no longer an offloaded context, so we don't want to
1351 * run offload-specific code on this context.
1352 */
1353 spin_lock_irqsave(&tls_device_lock, flags);
1354 list_move_tail(list: &ctx->list, head: &tls_device_down_list);
1355 spin_unlock_irqrestore(lock: &tls_device_lock, flags);
1356
1357 /* Device contexts for RX and TX will be freed in on sk_destruct
1358 * by tls_device_free_ctx. rx_conf and tx_conf stay in TLS_HW.
1359 * Now release the ref taken above.
1360 */
1361 if (refcount_dec_and_test(r: &ctx->refcount)) {
1362 /* sk_destruct ran after tls_device_down took a ref, and
1363 * it returned early. Complete the destruction here.
1364 */
1365 list_del(entry: &ctx->list);
1366 tls_device_free_ctx(ctx);
1367 }
1368 }
1369
1370 up_write(sem: &device_offload_lock);
1371
1372 flush_workqueue(destruct_wq);
1373
1374 return NOTIFY_DONE;
1375}
1376
1377static int tls_dev_event(struct notifier_block *this, unsigned long event,
1378 void *ptr)
1379{
1380 struct net_device *dev = netdev_notifier_info_to_dev(info: ptr);
1381
1382 if (!dev->tlsdev_ops &&
1383 !(dev->features & (NETIF_F_HW_TLS_RX | NETIF_F_HW_TLS_TX)))
1384 return NOTIFY_DONE;
1385
1386 switch (event) {
1387 case NETDEV_REGISTER:
1388 case NETDEV_FEAT_CHANGE:
1389 if (netif_is_bond_master(dev))
1390 return NOTIFY_DONE;
1391 if ((dev->features & NETIF_F_HW_TLS_RX) &&
1392 !dev->tlsdev_ops->tls_dev_resync)
1393 return NOTIFY_BAD;
1394
1395 if (dev->tlsdev_ops &&
1396 dev->tlsdev_ops->tls_dev_add &&
1397 dev->tlsdev_ops->tls_dev_del)
1398 return NOTIFY_DONE;
1399 else
1400 return NOTIFY_BAD;
1401 case NETDEV_DOWN:
1402 return tls_device_down(netdev: dev);
1403 }
1404 return NOTIFY_DONE;
1405}
1406
1407static struct notifier_block tls_dev_notifier = {
1408 .notifier_call = tls_dev_event,
1409};
1410
1411int __init tls_device_init(void)
1412{
1413 int err;
1414
1415 dummy_page = alloc_page(GFP_KERNEL);
1416 if (!dummy_page)
1417 return -ENOMEM;
1418
1419 destruct_wq = alloc_workqueue(fmt: "ktls_device_destruct", flags: 0, max_active: 0);
1420 if (!destruct_wq) {
1421 err = -ENOMEM;
1422 goto err_free_dummy;
1423 }
1424
1425 err = register_netdevice_notifier(nb: &tls_dev_notifier);
1426 if (err)
1427 goto err_destroy_wq;
1428
1429 return 0;
1430
1431err_destroy_wq:
1432 destroy_workqueue(wq: destruct_wq);
1433err_free_dummy:
1434 put_page(page: dummy_page);
1435 return err;
1436}
1437
1438void __exit tls_device_cleanup(void)
1439{
1440 unregister_netdevice_notifier(nb: &tls_dev_notifier);
1441 destroy_workqueue(wq: destruct_wq);
1442 clean_acked_data_flush();
1443 put_page(page: dummy_page);
1444}
1445

source code of linux/net/tls/tls_device.c