GNU Linux-libre 6.1.24-gnu
[releases.git] / net / tls / tls_device.c
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  */
47 static DECLARE_RWSEM(device_offload_lock);
48
49 static struct workqueue_struct *destruct_wq __read_mostly;
50
51 static LIST_HEAD(tls_device_list);
52 static LIST_HEAD(tls_device_down_list);
53 static DEFINE_SPINLOCK(tls_device_lock);
54
55 static void tls_device_free_ctx(struct tls_context *ctx)
56 {
57         if (ctx->tx_conf == TLS_HW) {
58                 kfree(tls_offload_ctx_tx(ctx));
59                 kfree(ctx->tx.rec_seq);
60                 kfree(ctx->tx.iv);
61         }
62
63         if (ctx->rx_conf == TLS_HW)
64                 kfree(tls_offload_ctx_rx(ctx));
65
66         tls_ctx_free(NULL, ctx);
67 }
68
69 static void tls_device_tx_del_task(struct work_struct *work)
70 {
71         struct tls_offload_context_tx *offload_ctx =
72                 container_of(work, struct tls_offload_context_tx, destruct_work);
73         struct tls_context *ctx = offload_ctx->ctx;
74         struct net_device *netdev;
75
76         /* Safe, because this is the destroy flow, refcount is 0, so
77          * tls_device_down can't store this field in parallel.
78          */
79         netdev = rcu_dereference_protected(ctx->netdev,
80                                            !refcount_read(&ctx->refcount));
81
82         netdev->tlsdev_ops->tls_dev_del(netdev, ctx, TLS_OFFLOAD_CTX_DIR_TX);
83         dev_put(netdev);
84         ctx->netdev = NULL;
85         tls_device_free_ctx(ctx);
86 }
87
88 static void tls_device_queue_ctx_destruction(struct tls_context *ctx)
89 {
90         struct net_device *netdev;
91         unsigned long flags;
92         bool async_cleanup;
93
94         spin_lock_irqsave(&tls_device_lock, flags);
95         if (unlikely(!refcount_dec_and_test(&ctx->refcount))) {
96                 spin_unlock_irqrestore(&tls_device_lock, flags);
97                 return;
98         }
99
100         list_del(&ctx->list); /* Remove from tls_device_list / tls_device_down_list */
101
102         /* Safe, because this is the destroy flow, refcount is 0, so
103          * tls_device_down can't store this field in parallel.
104          */
105         netdev = rcu_dereference_protected(ctx->netdev,
106                                            !refcount_read(&ctx->refcount));
107
108         async_cleanup = netdev && ctx->tx_conf == TLS_HW;
109         if (async_cleanup) {
110                 struct tls_offload_context_tx *offload_ctx = tls_offload_ctx_tx(ctx);
111
112                 /* queue_work inside the spinlock
113                  * to make sure tls_device_down waits for that work.
114                  */
115                 queue_work(destruct_wq, &offload_ctx->destruct_work);
116         }
117         spin_unlock_irqrestore(&tls_device_lock, flags);
118
119         if (!async_cleanup)
120                 tls_device_free_ctx(ctx);
121 }
122
123 /* We assume that the socket is already connected */
124 static struct net_device *get_netdev_for_sock(struct sock *sk)
125 {
126         struct dst_entry *dst = sk_dst_get(sk);
127         struct net_device *netdev = NULL;
128
129         if (likely(dst)) {
130                 netdev = netdev_sk_get_lowest_dev(dst->dev, sk);
131                 dev_hold(netdev);
132         }
133
134         dst_release(dst);
135
136         return netdev;
137 }
138
139 static void destroy_record(struct tls_record_info *record)
140 {
141         int i;
142
143         for (i = 0; i < record->num_frags; i++)
144                 __skb_frag_unref(&record->frags[i], false);
145         kfree(record);
146 }
147
148 static void delete_all_records(struct tls_offload_context_tx *offload_ctx)
149 {
150         struct tls_record_info *info, *temp;
151
152         list_for_each_entry_safe(info, temp, &offload_ctx->records_list, list) {
153                 list_del(&info->list);
154                 destroy_record(info);
155         }
156
157         offload_ctx->retransmit_hint = NULL;
158 }
159
160 static void tls_icsk_clean_acked(struct sock *sk, u32 acked_seq)
161 {
162         struct tls_context *tls_ctx = tls_get_ctx(sk);
163         struct tls_record_info *info, *temp;
164         struct tls_offload_context_tx *ctx;
165         u64 deleted_records = 0;
166         unsigned long flags;
167
168         if (!tls_ctx)
169                 return;
170
171         ctx = tls_offload_ctx_tx(tls_ctx);
172
173         spin_lock_irqsave(&ctx->lock, flags);
174         info = ctx->retransmit_hint;
175         if (info && !before(acked_seq, info->end_seq))
176                 ctx->retransmit_hint = NULL;
177
178         list_for_each_entry_safe(info, temp, &ctx->records_list, list) {
179                 if (before(acked_seq, info->end_seq))
180                         break;
181                 list_del(&info->list);
182
183                 destroy_record(info);
184                 deleted_records++;
185         }
186
187         ctx->unacked_record_sn += deleted_records;
188         spin_unlock_irqrestore(&ctx->lock, flags);
189 }
190
191 /* At this point, there should be no references on this
192  * socket and no in-flight SKBs associated with this
193  * socket, so it is safe to free all the resources.
194  */
195 void tls_device_sk_destruct(struct sock *sk)
196 {
197         struct tls_context *tls_ctx = tls_get_ctx(sk);
198         struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
199
200         tls_ctx->sk_destruct(sk);
201
202         if (tls_ctx->tx_conf == TLS_HW) {
203                 if (ctx->open_record)
204                         destroy_record(ctx->open_record);
205                 delete_all_records(ctx);
206                 crypto_free_aead(ctx->aead_send);
207                 clean_acked_data_disable(inet_csk(sk));
208         }
209
210         tls_device_queue_ctx_destruction(tls_ctx);
211 }
212 EXPORT_SYMBOL_GPL(tls_device_sk_destruct);
213
214 void tls_device_free_resources_tx(struct sock *sk)
215 {
216         struct tls_context *tls_ctx = tls_get_ctx(sk);
217
218         tls_free_partial_record(sk, tls_ctx);
219 }
220
221 void tls_offload_tx_resync_request(struct sock *sk, u32 got_seq, u32 exp_seq)
222 {
223         struct tls_context *tls_ctx = tls_get_ctx(sk);
224
225         trace_tls_device_tx_resync_req(sk, got_seq, exp_seq);
226         WARN_ON(test_and_set_bit(TLS_TX_SYNC_SCHED, &tls_ctx->flags));
227 }
228 EXPORT_SYMBOL_GPL(tls_offload_tx_resync_request);
229
230 static void tls_device_resync_tx(struct sock *sk, struct tls_context *tls_ctx,
231                                  u32 seq)
232 {
233         struct net_device *netdev;
234         struct sk_buff *skb;
235         int err = 0;
236         u8 *rcd_sn;
237
238         skb = tcp_write_queue_tail(sk);
239         if (skb)
240                 TCP_SKB_CB(skb)->eor = 1;
241
242         rcd_sn = tls_ctx->tx.rec_seq;
243
244         trace_tls_device_tx_resync_send(sk, seq, rcd_sn);
245         down_read(&device_offload_lock);
246         netdev = rcu_dereference_protected(tls_ctx->netdev,
247                                            lockdep_is_held(&device_offload_lock));
248         if (netdev)
249                 err = netdev->tlsdev_ops->tls_dev_resync(netdev, sk, seq,
250                                                          rcd_sn,
251                                                          TLS_OFFLOAD_CTX_DIR_TX);
252         up_read(&device_offload_lock);
253         if (err)
254                 return;
255
256         clear_bit_unlock(TLS_TX_SYNC_SCHED, &tls_ctx->flags);
257 }
258
259 static void tls_append_frag(struct tls_record_info *record,
260                             struct page_frag *pfrag,
261                             int size)
262 {
263         skb_frag_t *frag;
264
265         frag = &record->frags[record->num_frags - 1];
266         if (skb_frag_page(frag) == pfrag->page &&
267             skb_frag_off(frag) + skb_frag_size(frag) == pfrag->offset) {
268                 skb_frag_size_add(frag, size);
269         } else {
270                 ++frag;
271                 __skb_frag_set_page(frag, pfrag->page);
272                 skb_frag_off_set(frag, pfrag->offset);
273                 skb_frag_size_set(frag, size);
274                 ++record->num_frags;
275                 get_page(pfrag->page);
276         }
277
278         pfrag->offset += size;
279         record->len += size;
280 }
281
282 static int tls_push_record(struct sock *sk,
283                            struct tls_context *ctx,
284                            struct tls_offload_context_tx *offload_ctx,
285                            struct tls_record_info *record,
286                            int flags)
287 {
288         struct tls_prot_info *prot = &ctx->prot_info;
289         struct tcp_sock *tp = tcp_sk(sk);
290         skb_frag_t *frag;
291         int i;
292
293         record->end_seq = tp->write_seq + record->len;
294         list_add_tail_rcu(&record->list, &offload_ctx->records_list);
295         offload_ctx->open_record = NULL;
296
297         if (test_bit(TLS_TX_SYNC_SCHED, &ctx->flags))
298                 tls_device_resync_tx(sk, ctx, tp->write_seq);
299
300         tls_advance_record_sn(sk, prot, &ctx->tx);
301
302         for (i = 0; i < record->num_frags; i++) {
303                 frag = &record->frags[i];
304                 sg_unmark_end(&offload_ctx->sg_tx_data[i]);
305                 sg_set_page(&offload_ctx->sg_tx_data[i], skb_frag_page(frag),
306                             skb_frag_size(frag), skb_frag_off(frag));
307                 sk_mem_charge(sk, skb_frag_size(frag));
308                 get_page(skb_frag_page(frag));
309         }
310         sg_mark_end(&offload_ctx->sg_tx_data[record->num_frags - 1]);
311
312         /* all ready, send */
313         return tls_push_sg(sk, ctx, offload_ctx->sg_tx_data, 0, flags);
314 }
315
316 static int tls_device_record_close(struct sock *sk,
317                                    struct tls_context *ctx,
318                                    struct tls_record_info *record,
319                                    struct page_frag *pfrag,
320                                    unsigned char record_type)
321 {
322         struct tls_prot_info *prot = &ctx->prot_info;
323         int ret;
324
325         /* append tag
326          * device will fill in the tag, we just need to append a placeholder
327          * use socket memory to improve coalescing (re-using a single buffer
328          * increases frag count)
329          * if we can't allocate memory now, steal some back from data
330          */
331         if (likely(skb_page_frag_refill(prot->tag_size, pfrag,
332                                         sk->sk_allocation))) {
333                 ret = 0;
334                 tls_append_frag(record, pfrag, prot->tag_size);
335         } else {
336                 ret = prot->tag_size;
337                 if (record->len <= prot->overhead_size)
338                         return -ENOMEM;
339         }
340
341         /* fill prepend */
342         tls_fill_prepend(ctx, skb_frag_address(&record->frags[0]),
343                          record->len - prot->overhead_size,
344                          record_type);
345         return ret;
346 }
347
348 static int tls_create_new_record(struct tls_offload_context_tx *offload_ctx,
349                                  struct page_frag *pfrag,
350                                  size_t prepend_size)
351 {
352         struct tls_record_info *record;
353         skb_frag_t *frag;
354
355         record = kmalloc(sizeof(*record), GFP_KERNEL);
356         if (!record)
357                 return -ENOMEM;
358
359         frag = &record->frags[0];
360         __skb_frag_set_page(frag, pfrag->page);
361         skb_frag_off_set(frag, pfrag->offset);
362         skb_frag_size_set(frag, prepend_size);
363
364         get_page(pfrag->page);
365         pfrag->offset += prepend_size;
366
367         record->num_frags = 1;
368         record->len = prepend_size;
369         offload_ctx->open_record = record;
370         return 0;
371 }
372
373 static int tls_do_allocation(struct sock *sk,
374                              struct tls_offload_context_tx *offload_ctx,
375                              struct page_frag *pfrag,
376                              size_t prepend_size)
377 {
378         int ret;
379
380         if (!offload_ctx->open_record) {
381                 if (unlikely(!skb_page_frag_refill(prepend_size, pfrag,
382                                                    sk->sk_allocation))) {
383                         READ_ONCE(sk->sk_prot)->enter_memory_pressure(sk);
384                         sk_stream_moderate_sndbuf(sk);
385                         return -ENOMEM;
386                 }
387
388                 ret = tls_create_new_record(offload_ctx, pfrag, prepend_size);
389                 if (ret)
390                         return ret;
391
392                 if (pfrag->size > pfrag->offset)
393                         return 0;
394         }
395
396         if (!sk_page_frag_refill(sk, pfrag))
397                 return -ENOMEM;
398
399         return 0;
400 }
401
402 static int tls_device_copy_data(void *addr, size_t bytes, struct iov_iter *i)
403 {
404         size_t pre_copy, nocache;
405
406         pre_copy = ~((unsigned long)addr - 1) & (SMP_CACHE_BYTES - 1);
407         if (pre_copy) {
408                 pre_copy = min(pre_copy, bytes);
409                 if (copy_from_iter(addr, pre_copy, i) != pre_copy)
410                         return -EFAULT;
411                 bytes -= pre_copy;
412                 addr += pre_copy;
413         }
414
415         nocache = round_down(bytes, SMP_CACHE_BYTES);
416         if (copy_from_iter_nocache(addr, nocache, i) != nocache)
417                 return -EFAULT;
418         bytes -= nocache;
419         addr += nocache;
420
421         if (bytes && copy_from_iter(addr, bytes, i) != bytes)
422                 return -EFAULT;
423
424         return 0;
425 }
426
427 union tls_iter_offset {
428         struct iov_iter *msg_iter;
429         int offset;
430 };
431
432 static int tls_push_data(struct sock *sk,
433                          union tls_iter_offset iter_offset,
434                          size_t size, int flags,
435                          unsigned char record_type,
436                          struct page *zc_page)
437 {
438         struct tls_context *tls_ctx = tls_get_ctx(sk);
439         struct tls_prot_info *prot = &tls_ctx->prot_info;
440         struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
441         struct tls_record_info *record;
442         int tls_push_record_flags;
443         struct page_frag *pfrag;
444         size_t orig_size = size;
445         u32 max_open_record_len;
446         bool more = false;
447         bool done = false;
448         int copy, rc = 0;
449         long timeo;
450
451         if (flags &
452             ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL | MSG_SENDPAGE_NOTLAST))
453                 return -EOPNOTSUPP;
454
455         if (unlikely(sk->sk_err))
456                 return -sk->sk_err;
457
458         flags |= MSG_SENDPAGE_DECRYPTED;
459         tls_push_record_flags = flags | MSG_SENDPAGE_NOTLAST;
460
461         timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
462         if (tls_is_partially_sent_record(tls_ctx)) {
463                 rc = tls_push_partial_record(sk, tls_ctx, flags);
464                 if (rc < 0)
465                         return rc;
466         }
467
468         pfrag = sk_page_frag(sk);
469
470         /* TLS_HEADER_SIZE is not counted as part of the TLS record, and
471          * we need to leave room for an authentication tag.
472          */
473         max_open_record_len = TLS_MAX_PAYLOAD_SIZE +
474                               prot->prepend_size;
475         do {
476                 rc = tls_do_allocation(sk, ctx, pfrag, prot->prepend_size);
477                 if (unlikely(rc)) {
478                         rc = sk_stream_wait_memory(sk, &timeo);
479                         if (!rc)
480                                 continue;
481
482                         record = ctx->open_record;
483                         if (!record)
484                                 break;
485 handle_error:
486                         if (record_type != TLS_RECORD_TYPE_DATA) {
487                                 /* avoid sending partial
488                                  * record with type !=
489                                  * application_data
490                                  */
491                                 size = orig_size;
492                                 destroy_record(record);
493                                 ctx->open_record = NULL;
494                         } else if (record->len > prot->prepend_size) {
495                                 goto last_record;
496                         }
497
498                         break;
499                 }
500
501                 record = ctx->open_record;
502
503                 copy = min_t(size_t, size, max_open_record_len - record->len);
504                 if (copy && zc_page) {
505                         struct page_frag zc_pfrag;
506
507                         zc_pfrag.page = zc_page;
508                         zc_pfrag.offset = iter_offset.offset;
509                         zc_pfrag.size = copy;
510                         tls_append_frag(record, &zc_pfrag, copy);
511
512                         iter_offset.offset += copy;
513                 } else if (copy) {
514                         copy = min_t(size_t, copy, pfrag->size - pfrag->offset);
515
516                         rc = tls_device_copy_data(page_address(pfrag->page) +
517                                                   pfrag->offset, copy,
518                                                   iter_offset.msg_iter);
519                         if (rc)
520                                 goto handle_error;
521                         tls_append_frag(record, pfrag, copy);
522                 }
523
524                 size -= copy;
525                 if (!size) {
526 last_record:
527                         tls_push_record_flags = flags;
528                         if (flags & (MSG_SENDPAGE_NOTLAST | MSG_MORE)) {
529                                 more = true;
530                                 break;
531                         }
532
533                         done = true;
534                 }
535
536                 if (done || record->len >= max_open_record_len ||
537                     (record->num_frags >= MAX_SKB_FRAGS - 1)) {
538                         rc = tls_device_record_close(sk, tls_ctx, record,
539                                                      pfrag, record_type);
540                         if (rc) {
541                                 if (rc > 0) {
542                                         size += rc;
543                                 } else {
544                                         size = orig_size;
545                                         destroy_record(record);
546                                         ctx->open_record = NULL;
547                                         break;
548                                 }
549                         }
550
551                         rc = tls_push_record(sk,
552                                              tls_ctx,
553                                              ctx,
554                                              record,
555                                              tls_push_record_flags);
556                         if (rc < 0)
557                                 break;
558                 }
559         } while (!done);
560
561         tls_ctx->pending_open_record_frags = more;
562
563         if (orig_size - size > 0)
564                 rc = orig_size - size;
565
566         return rc;
567 }
568
569 int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
570 {
571         unsigned char record_type = TLS_RECORD_TYPE_DATA;
572         struct tls_context *tls_ctx = tls_get_ctx(sk);
573         union tls_iter_offset iter;
574         int rc;
575
576         mutex_lock(&tls_ctx->tx_lock);
577         lock_sock(sk);
578
579         if (unlikely(msg->msg_controllen)) {
580                 rc = tls_process_cmsg(sk, msg, &record_type);
581                 if (rc)
582                         goto out;
583         }
584
585         iter.msg_iter = &msg->msg_iter;
586         rc = tls_push_data(sk, iter, size, msg->msg_flags, record_type, NULL);
587
588 out:
589         release_sock(sk);
590         mutex_unlock(&tls_ctx->tx_lock);
591         return rc;
592 }
593
594 int tls_device_sendpage(struct sock *sk, struct page *page,
595                         int offset, size_t size, int flags)
596 {
597         struct tls_context *tls_ctx = tls_get_ctx(sk);
598         union tls_iter_offset iter_offset;
599         struct iov_iter msg_iter;
600         char *kaddr;
601         struct kvec iov;
602         int rc;
603
604         if (flags & MSG_SENDPAGE_NOTLAST)
605                 flags |= MSG_MORE;
606
607         mutex_lock(&tls_ctx->tx_lock);
608         lock_sock(sk);
609
610         if (flags & MSG_OOB) {
611                 rc = -EOPNOTSUPP;
612                 goto out;
613         }
614
615         if (tls_ctx->zerocopy_sendfile) {
616                 iter_offset.offset = offset;
617                 rc = tls_push_data(sk, iter_offset, size,
618                                    flags, TLS_RECORD_TYPE_DATA, page);
619                 goto out;
620         }
621
622         kaddr = kmap(page);
623         iov.iov_base = kaddr + offset;
624         iov.iov_len = size;
625         iov_iter_kvec(&msg_iter, ITER_SOURCE, &iov, 1, size);
626         iter_offset.msg_iter = &msg_iter;
627         rc = tls_push_data(sk, iter_offset, size, flags, TLS_RECORD_TYPE_DATA,
628                            NULL);
629         kunmap(page);
630
631 out:
632         release_sock(sk);
633         mutex_unlock(&tls_ctx->tx_lock);
634         return rc;
635 }
636
637 struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context,
638                                        u32 seq, u64 *p_record_sn)
639 {
640         u64 record_sn = context->hint_record_sn;
641         struct tls_record_info *info, *last;
642
643         info = context->retransmit_hint;
644         if (!info ||
645             before(seq, info->end_seq - info->len)) {
646                 /* if retransmit_hint is irrelevant start
647                  * from the beginning of the list
648                  */
649                 info = list_first_entry_or_null(&context->records_list,
650                                                 struct tls_record_info, list);
651                 if (!info)
652                         return NULL;
653                 /* send the start_marker record if seq number is before the
654                  * tls offload start marker sequence number. This record is
655                  * required to handle TCP packets which are before TLS offload
656                  * started.
657                  *  And if it's not start marker, look if this seq number
658                  * belongs to the list.
659                  */
660                 if (likely(!tls_record_is_start_marker(info))) {
661                         /* we have the first record, get the last record to see
662                          * if this seq number belongs to the list.
663                          */
664                         last = list_last_entry(&context->records_list,
665                                                struct tls_record_info, list);
666
667                         if (!between(seq, tls_record_start_seq(info),
668                                      last->end_seq))
669                                 return NULL;
670                 }
671                 record_sn = context->unacked_record_sn;
672         }
673
674         /* We just need the _rcu for the READ_ONCE() */
675         rcu_read_lock();
676         list_for_each_entry_from_rcu(info, &context->records_list, list) {
677                 if (before(seq, info->end_seq)) {
678                         if (!context->retransmit_hint ||
679                             after(info->end_seq,
680                                   context->retransmit_hint->end_seq)) {
681                                 context->hint_record_sn = record_sn;
682                                 context->retransmit_hint = info;
683                         }
684                         *p_record_sn = record_sn;
685                         goto exit_rcu_unlock;
686                 }
687                 record_sn++;
688         }
689         info = NULL;
690
691 exit_rcu_unlock:
692         rcu_read_unlock();
693         return info;
694 }
695 EXPORT_SYMBOL(tls_get_record);
696
697 static int tls_device_push_pending_record(struct sock *sk, int flags)
698 {
699         union tls_iter_offset iter;
700         struct iov_iter msg_iter;
701
702         iov_iter_kvec(&msg_iter, ITER_SOURCE, NULL, 0, 0);
703         iter.msg_iter = &msg_iter;
704         return tls_push_data(sk, iter, 0, flags, TLS_RECORD_TYPE_DATA, NULL);
705 }
706
707 void tls_device_write_space(struct sock *sk, struct tls_context *ctx)
708 {
709         if (tls_is_partially_sent_record(ctx)) {
710                 gfp_t sk_allocation = sk->sk_allocation;
711
712                 WARN_ON_ONCE(sk->sk_write_pending);
713
714                 sk->sk_allocation = GFP_ATOMIC;
715                 tls_push_partial_record(sk, ctx,
716                                         MSG_DONTWAIT | MSG_NOSIGNAL |
717                                         MSG_SENDPAGE_DECRYPTED);
718                 sk->sk_allocation = sk_allocation;
719         }
720 }
721
722 static void tls_device_resync_rx(struct tls_context *tls_ctx,
723                                  struct sock *sk, u32 seq, u8 *rcd_sn)
724 {
725         struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
726         struct net_device *netdev;
727
728         trace_tls_device_rx_resync_send(sk, seq, rcd_sn, rx_ctx->resync_type);
729         rcu_read_lock();
730         netdev = rcu_dereference(tls_ctx->netdev);
731         if (netdev)
732                 netdev->tlsdev_ops->tls_dev_resync(netdev, sk, seq, rcd_sn,
733                                                    TLS_OFFLOAD_CTX_DIR_RX);
734         rcu_read_unlock();
735         TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSRXDEVICERESYNC);
736 }
737
738 static bool
739 tls_device_rx_resync_async(struct tls_offload_resync_async *resync_async,
740                            s64 resync_req, u32 *seq, u16 *rcd_delta)
741 {
742         u32 is_async = resync_req & RESYNC_REQ_ASYNC;
743         u32 req_seq = resync_req >> 32;
744         u32 req_end = req_seq + ((resync_req >> 16) & 0xffff);
745         u16 i;
746
747         *rcd_delta = 0;
748
749         if (is_async) {
750                 /* shouldn't get to wraparound:
751                  * too long in async stage, something bad happened
752                  */
753                 if (WARN_ON_ONCE(resync_async->rcd_delta == USHRT_MAX))
754                         return false;
755
756                 /* asynchronous stage: log all headers seq such that
757                  * req_seq <= seq <= end_seq, and wait for real resync request
758                  */
759                 if (before(*seq, req_seq))
760                         return false;
761                 if (!after(*seq, req_end) &&
762                     resync_async->loglen < TLS_DEVICE_RESYNC_ASYNC_LOGMAX)
763                         resync_async->log[resync_async->loglen++] = *seq;
764
765                 resync_async->rcd_delta++;
766
767                 return false;
768         }
769
770         /* synchronous stage: check against the logged entries and
771          * proceed to check the next entries if no match was found
772          */
773         for (i = 0; i < resync_async->loglen; i++)
774                 if (req_seq == resync_async->log[i] &&
775                     atomic64_try_cmpxchg(&resync_async->req, &resync_req, 0)) {
776                         *rcd_delta = resync_async->rcd_delta - i;
777                         *seq = req_seq;
778                         resync_async->loglen = 0;
779                         resync_async->rcd_delta = 0;
780                         return true;
781                 }
782
783         resync_async->loglen = 0;
784         resync_async->rcd_delta = 0;
785
786         if (req_seq == *seq &&
787             atomic64_try_cmpxchg(&resync_async->req,
788                                  &resync_req, 0))
789                 return true;
790
791         return false;
792 }
793
794 void tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq)
795 {
796         struct tls_context *tls_ctx = tls_get_ctx(sk);
797         struct tls_offload_context_rx *rx_ctx;
798         u8 rcd_sn[TLS_MAX_REC_SEQ_SIZE];
799         u32 sock_data, is_req_pending;
800         struct tls_prot_info *prot;
801         s64 resync_req;
802         u16 rcd_delta;
803         u32 req_seq;
804
805         if (tls_ctx->rx_conf != TLS_HW)
806                 return;
807         if (unlikely(test_bit(TLS_RX_DEV_DEGRADED, &tls_ctx->flags)))
808                 return;
809
810         prot = &tls_ctx->prot_info;
811         rx_ctx = tls_offload_ctx_rx(tls_ctx);
812         memcpy(rcd_sn, tls_ctx->rx.rec_seq, prot->rec_seq_size);
813
814         switch (rx_ctx->resync_type) {
815         case TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ:
816                 resync_req = atomic64_read(&rx_ctx->resync_req);
817                 req_seq = resync_req >> 32;
818                 seq += TLS_HEADER_SIZE - 1;
819                 is_req_pending = resync_req;
820
821                 if (likely(!is_req_pending) || req_seq != seq ||
822                     !atomic64_try_cmpxchg(&rx_ctx->resync_req, &resync_req, 0))
823                         return;
824                 break;
825         case TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT:
826                 if (likely(!rx_ctx->resync_nh_do_now))
827                         return;
828
829                 /* head of next rec is already in, note that the sock_inq will
830                  * include the currently parsed message when called from parser
831                  */
832                 sock_data = tcp_inq(sk);
833                 if (sock_data > rcd_len) {
834                         trace_tls_device_rx_resync_nh_delay(sk, sock_data,
835                                                             rcd_len);
836                         return;
837                 }
838
839                 rx_ctx->resync_nh_do_now = 0;
840                 seq += rcd_len;
841                 tls_bigint_increment(rcd_sn, prot->rec_seq_size);
842                 break;
843         case TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ_ASYNC:
844                 resync_req = atomic64_read(&rx_ctx->resync_async->req);
845                 is_req_pending = resync_req;
846                 if (likely(!is_req_pending))
847                         return;
848
849                 if (!tls_device_rx_resync_async(rx_ctx->resync_async,
850                                                 resync_req, &seq, &rcd_delta))
851                         return;
852                 tls_bigint_subtract(rcd_sn, rcd_delta);
853                 break;
854         }
855
856         tls_device_resync_rx(tls_ctx, sk, seq, rcd_sn);
857 }
858
859 static void tls_device_core_ctrl_rx_resync(struct tls_context *tls_ctx,
860                                            struct tls_offload_context_rx *ctx,
861                                            struct sock *sk, struct sk_buff *skb)
862 {
863         struct strp_msg *rxm;
864
865         /* device will request resyncs by itself based on stream scan */
866         if (ctx->resync_type != TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT)
867                 return;
868         /* already scheduled */
869         if (ctx->resync_nh_do_now)
870                 return;
871         /* seen decrypted fragments since last fully-failed record */
872         if (ctx->resync_nh_reset) {
873                 ctx->resync_nh_reset = 0;
874                 ctx->resync_nh.decrypted_failed = 1;
875                 ctx->resync_nh.decrypted_tgt = TLS_DEVICE_RESYNC_NH_START_IVAL;
876                 return;
877         }
878
879         if (++ctx->resync_nh.decrypted_failed <= ctx->resync_nh.decrypted_tgt)
880                 return;
881
882         /* doing resync, bump the next target in case it fails */
883         if (ctx->resync_nh.decrypted_tgt < TLS_DEVICE_RESYNC_NH_MAX_IVAL)
884                 ctx->resync_nh.decrypted_tgt *= 2;
885         else
886                 ctx->resync_nh.decrypted_tgt += TLS_DEVICE_RESYNC_NH_MAX_IVAL;
887
888         rxm = strp_msg(skb);
889
890         /* head of next rec is already in, parser will sync for us */
891         if (tcp_inq(sk) > rxm->full_len) {
892                 trace_tls_device_rx_resync_nh_schedule(sk);
893                 ctx->resync_nh_do_now = 1;
894         } else {
895                 struct tls_prot_info *prot = &tls_ctx->prot_info;
896                 u8 rcd_sn[TLS_MAX_REC_SEQ_SIZE];
897
898                 memcpy(rcd_sn, tls_ctx->rx.rec_seq, prot->rec_seq_size);
899                 tls_bigint_increment(rcd_sn, prot->rec_seq_size);
900
901                 tls_device_resync_rx(tls_ctx, sk, tcp_sk(sk)->copied_seq,
902                                      rcd_sn);
903         }
904 }
905
906 static int
907 tls_device_reencrypt(struct sock *sk, struct tls_context *tls_ctx)
908 {
909         struct tls_sw_context_rx *sw_ctx = tls_sw_ctx_rx(tls_ctx);
910         const struct tls_cipher_size_desc *cipher_sz;
911         int err, offset, copy, data_len, pos;
912         struct sk_buff *skb, *skb_iter;
913         struct scatterlist sg[1];
914         struct strp_msg *rxm;
915         char *orig_buf, *buf;
916
917         switch (tls_ctx->crypto_recv.info.cipher_type) {
918         case TLS_CIPHER_AES_GCM_128:
919         case TLS_CIPHER_AES_GCM_256:
920                 break;
921         default:
922                 return -EINVAL;
923         }
924         cipher_sz = &tls_cipher_size_desc[tls_ctx->crypto_recv.info.cipher_type];
925
926         rxm = strp_msg(tls_strp_msg(sw_ctx));
927         orig_buf = kmalloc(rxm->full_len + TLS_HEADER_SIZE + cipher_sz->iv,
928                            sk->sk_allocation);
929         if (!orig_buf)
930                 return -ENOMEM;
931         buf = orig_buf;
932
933         err = tls_strp_msg_cow(sw_ctx);
934         if (unlikely(err))
935                 goto free_buf;
936
937         skb = tls_strp_msg(sw_ctx);
938         rxm = strp_msg(skb);
939         offset = rxm->offset;
940
941         sg_init_table(sg, 1);
942         sg_set_buf(&sg[0], buf,
943                    rxm->full_len + TLS_HEADER_SIZE + cipher_sz->iv);
944         err = skb_copy_bits(skb, offset, buf, TLS_HEADER_SIZE + cipher_sz->iv);
945         if (err)
946                 goto free_buf;
947
948         /* We are interested only in the decrypted data not the auth */
949         err = decrypt_skb(sk, sg);
950         if (err != -EBADMSG)
951                 goto free_buf;
952         else
953                 err = 0;
954
955         data_len = rxm->full_len - cipher_sz->tag;
956
957         if (skb_pagelen(skb) > offset) {
958                 copy = min_t(int, skb_pagelen(skb) - offset, data_len);
959
960                 if (skb->decrypted) {
961                         err = skb_store_bits(skb, offset, buf, copy);
962                         if (err)
963                                 goto free_buf;
964                 }
965
966                 offset += copy;
967                 buf += copy;
968         }
969
970         pos = skb_pagelen(skb);
971         skb_walk_frags(skb, skb_iter) {
972                 int frag_pos;
973
974                 /* Practically all frags must belong to msg if reencrypt
975                  * is needed with current strparser and coalescing logic,
976                  * but strparser may "get optimized", so let's be safe.
977                  */
978                 if (pos + skb_iter->len <= offset)
979                         goto done_with_frag;
980                 if (pos >= data_len + rxm->offset)
981                         break;
982
983                 frag_pos = offset - pos;
984                 copy = min_t(int, skb_iter->len - frag_pos,
985                              data_len + rxm->offset - offset);
986
987                 if (skb_iter->decrypted) {
988                         err = skb_store_bits(skb_iter, frag_pos, buf, copy);
989                         if (err)
990                                 goto free_buf;
991                 }
992
993                 offset += copy;
994                 buf += copy;
995 done_with_frag:
996                 pos += skb_iter->len;
997         }
998
999 free_buf:
1000         kfree(orig_buf);
1001         return err;
1002 }
1003
1004 int tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx)
1005 {
1006         struct tls_offload_context_rx *ctx = tls_offload_ctx_rx(tls_ctx);
1007         struct tls_sw_context_rx *sw_ctx = tls_sw_ctx_rx(tls_ctx);
1008         struct sk_buff *skb = tls_strp_msg(sw_ctx);
1009         struct strp_msg *rxm = strp_msg(skb);
1010         int is_decrypted = skb->decrypted;
1011         int is_encrypted = !is_decrypted;
1012         struct sk_buff *skb_iter;
1013         int left;
1014
1015         left = rxm->full_len - skb->len;
1016         /* Check if all the data is decrypted already */
1017         skb_iter = skb_shinfo(skb)->frag_list;
1018         while (skb_iter && left > 0) {
1019                 is_decrypted &= skb_iter->decrypted;
1020                 is_encrypted &= !skb_iter->decrypted;
1021
1022                 left -= skb_iter->len;
1023                 skb_iter = skb_iter->next;
1024         }
1025
1026         trace_tls_device_decrypted(sk, tcp_sk(sk)->copied_seq - rxm->full_len,
1027                                    tls_ctx->rx.rec_seq, rxm->full_len,
1028                                    is_encrypted, is_decrypted);
1029
1030         if (unlikely(test_bit(TLS_RX_DEV_DEGRADED, &tls_ctx->flags))) {
1031                 if (likely(is_encrypted || is_decrypted))
1032                         return is_decrypted;
1033
1034                 /* After tls_device_down disables the offload, the next SKB will
1035                  * likely have initial fragments decrypted, and final ones not
1036                  * decrypted. We need to reencrypt that single SKB.
1037                  */
1038                 return tls_device_reencrypt(sk, tls_ctx);
1039         }
1040
1041         /* Return immediately if the record is either entirely plaintext or
1042          * entirely ciphertext. Otherwise handle reencrypt partially decrypted
1043          * record.
1044          */
1045         if (is_decrypted) {
1046                 ctx->resync_nh_reset = 1;
1047                 return is_decrypted;
1048         }
1049         if (is_encrypted) {
1050                 tls_device_core_ctrl_rx_resync(tls_ctx, ctx, sk, skb);
1051                 return 0;
1052         }
1053
1054         ctx->resync_nh_reset = 1;
1055         return tls_device_reencrypt(sk, tls_ctx);
1056 }
1057
1058 static void tls_device_attach(struct tls_context *ctx, struct sock *sk,
1059                               struct net_device *netdev)
1060 {
1061         if (sk->sk_destruct != tls_device_sk_destruct) {
1062                 refcount_set(&ctx->refcount, 1);
1063                 dev_hold(netdev);
1064                 RCU_INIT_POINTER(ctx->netdev, netdev);
1065                 spin_lock_irq(&tls_device_lock);
1066                 list_add_tail(&ctx->list, &tls_device_list);
1067                 spin_unlock_irq(&tls_device_lock);
1068
1069                 ctx->sk_destruct = sk->sk_destruct;
1070                 smp_store_release(&sk->sk_destruct, tls_device_sk_destruct);
1071         }
1072 }
1073
1074 int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
1075 {
1076         struct tls_context *tls_ctx = tls_get_ctx(sk);
1077         struct tls_prot_info *prot = &tls_ctx->prot_info;
1078         const struct tls_cipher_size_desc *cipher_sz;
1079         struct tls_record_info *start_marker_record;
1080         struct tls_offload_context_tx *offload_ctx;
1081         struct tls_crypto_info *crypto_info;
1082         struct net_device *netdev;
1083         char *iv, *rec_seq;
1084         struct sk_buff *skb;
1085         __be64 rcd_sn;
1086         int rc;
1087
1088         if (!ctx)
1089                 return -EINVAL;
1090
1091         if (ctx->priv_ctx_tx)
1092                 return -EEXIST;
1093
1094         netdev = get_netdev_for_sock(sk);
1095         if (!netdev) {
1096                 pr_err_ratelimited("%s: netdev not found\n", __func__);
1097                 return -EINVAL;
1098         }
1099
1100         if (!(netdev->features & NETIF_F_HW_TLS_TX)) {
1101                 rc = -EOPNOTSUPP;
1102                 goto release_netdev;
1103         }
1104
1105         crypto_info = &ctx->crypto_send.info;
1106         if (crypto_info->version != TLS_1_2_VERSION) {
1107                 rc = -EOPNOTSUPP;
1108                 goto release_netdev;
1109         }
1110
1111         switch (crypto_info->cipher_type) {
1112         case TLS_CIPHER_AES_GCM_128:
1113                 iv = ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->iv;
1114                 rec_seq =
1115                  ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->rec_seq;
1116                 break;
1117         case TLS_CIPHER_AES_GCM_256:
1118                 iv = ((struct tls12_crypto_info_aes_gcm_256 *)crypto_info)->iv;
1119                 rec_seq =
1120                  ((struct tls12_crypto_info_aes_gcm_256 *)crypto_info)->rec_seq;
1121                 break;
1122         default:
1123                 rc = -EINVAL;
1124                 goto release_netdev;
1125         }
1126         cipher_sz = &tls_cipher_size_desc[crypto_info->cipher_type];
1127
1128         /* Sanity-check the rec_seq_size for stack allocations */
1129         if (cipher_sz->rec_seq > TLS_MAX_REC_SEQ_SIZE) {
1130                 rc = -EINVAL;
1131                 goto release_netdev;
1132         }
1133
1134         prot->version = crypto_info->version;
1135         prot->cipher_type = crypto_info->cipher_type;
1136         prot->prepend_size = TLS_HEADER_SIZE + cipher_sz->iv;
1137         prot->tag_size = cipher_sz->tag;
1138         prot->overhead_size = prot->prepend_size + prot->tag_size;
1139         prot->iv_size = cipher_sz->iv;
1140         prot->salt_size = cipher_sz->salt;
1141         ctx->tx.iv = kmalloc(cipher_sz->iv + cipher_sz->salt, GFP_KERNEL);
1142         if (!ctx->tx.iv) {
1143                 rc = -ENOMEM;
1144                 goto release_netdev;
1145         }
1146
1147         memcpy(ctx->tx.iv + cipher_sz->salt, iv, cipher_sz->iv);
1148
1149         prot->rec_seq_size = cipher_sz->rec_seq;
1150         ctx->tx.rec_seq = kmemdup(rec_seq, cipher_sz->rec_seq, GFP_KERNEL);
1151         if (!ctx->tx.rec_seq) {
1152                 rc = -ENOMEM;
1153                 goto free_iv;
1154         }
1155
1156         start_marker_record = kmalloc(sizeof(*start_marker_record), GFP_KERNEL);
1157         if (!start_marker_record) {
1158                 rc = -ENOMEM;
1159                 goto free_rec_seq;
1160         }
1161
1162         offload_ctx = kzalloc(TLS_OFFLOAD_CONTEXT_SIZE_TX, GFP_KERNEL);
1163         if (!offload_ctx) {
1164                 rc = -ENOMEM;
1165                 goto free_marker_record;
1166         }
1167
1168         rc = tls_sw_fallback_init(sk, offload_ctx, crypto_info);
1169         if (rc)
1170                 goto free_offload_ctx;
1171
1172         /* start at rec_seq - 1 to account for the start marker record */
1173         memcpy(&rcd_sn, ctx->tx.rec_seq, sizeof(rcd_sn));
1174         offload_ctx->unacked_record_sn = be64_to_cpu(rcd_sn) - 1;
1175
1176         start_marker_record->end_seq = tcp_sk(sk)->write_seq;
1177         start_marker_record->len = 0;
1178         start_marker_record->num_frags = 0;
1179
1180         INIT_WORK(&offload_ctx->destruct_work, tls_device_tx_del_task);
1181         offload_ctx->ctx = ctx;
1182
1183         INIT_LIST_HEAD(&offload_ctx->records_list);
1184         list_add_tail(&start_marker_record->list, &offload_ctx->records_list);
1185         spin_lock_init(&offload_ctx->lock);
1186         sg_init_table(offload_ctx->sg_tx_data,
1187                       ARRAY_SIZE(offload_ctx->sg_tx_data));
1188
1189         clean_acked_data_enable(inet_csk(sk), &tls_icsk_clean_acked);
1190         ctx->push_pending_record = tls_device_push_pending_record;
1191
1192         /* TLS offload is greatly simplified if we don't send
1193          * SKBs where only part of the payload needs to be encrypted.
1194          * So mark the last skb in the write queue as end of record.
1195          */
1196         skb = tcp_write_queue_tail(sk);
1197         if (skb)
1198                 TCP_SKB_CB(skb)->eor = 1;
1199
1200         /* Avoid offloading if the device is down
1201          * We don't want to offload new flows after
1202          * the NETDEV_DOWN event
1203          *
1204          * device_offload_lock is taken in tls_devices's NETDEV_DOWN
1205          * handler thus protecting from the device going down before
1206          * ctx was added to tls_device_list.
1207          */
1208         down_read(&device_offload_lock);
1209         if (!(netdev->flags & IFF_UP)) {
1210                 rc = -EINVAL;
1211                 goto release_lock;
1212         }
1213
1214         ctx->priv_ctx_tx = offload_ctx;
1215         rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_TX,
1216                                              &ctx->crypto_send.info,
1217                                              tcp_sk(sk)->write_seq);
1218         trace_tls_device_offload_set(sk, TLS_OFFLOAD_CTX_DIR_TX,
1219                                      tcp_sk(sk)->write_seq, rec_seq, rc);
1220         if (rc)
1221                 goto release_lock;
1222
1223         tls_device_attach(ctx, sk, netdev);
1224         up_read(&device_offload_lock);
1225
1226         /* following this assignment tls_is_sk_tx_device_offloaded
1227          * will return true and the context might be accessed
1228          * by the netdev's xmit function.
1229          */
1230         smp_store_release(&sk->sk_validate_xmit_skb, tls_validate_xmit_skb);
1231         dev_put(netdev);
1232
1233         return 0;
1234
1235 release_lock:
1236         up_read(&device_offload_lock);
1237         clean_acked_data_disable(inet_csk(sk));
1238         crypto_free_aead(offload_ctx->aead_send);
1239 free_offload_ctx:
1240         kfree(offload_ctx);
1241         ctx->priv_ctx_tx = NULL;
1242 free_marker_record:
1243         kfree(start_marker_record);
1244 free_rec_seq:
1245         kfree(ctx->tx.rec_seq);
1246 free_iv:
1247         kfree(ctx->tx.iv);
1248 release_netdev:
1249         dev_put(netdev);
1250         return rc;
1251 }
1252
1253 int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
1254 {
1255         struct tls12_crypto_info_aes_gcm_128 *info;
1256         struct tls_offload_context_rx *context;
1257         struct net_device *netdev;
1258         int rc = 0;
1259
1260         if (ctx->crypto_recv.info.version != TLS_1_2_VERSION)
1261                 return -EOPNOTSUPP;
1262
1263         netdev = get_netdev_for_sock(sk);
1264         if (!netdev) {
1265                 pr_err_ratelimited("%s: netdev not found\n", __func__);
1266                 return -EINVAL;
1267         }
1268
1269         if (!(netdev->features & NETIF_F_HW_TLS_RX)) {
1270                 rc = -EOPNOTSUPP;
1271                 goto release_netdev;
1272         }
1273
1274         /* Avoid offloading if the device is down
1275          * We don't want to offload new flows after
1276          * the NETDEV_DOWN event
1277          *
1278          * device_offload_lock is taken in tls_devices's NETDEV_DOWN
1279          * handler thus protecting from the device going down before
1280          * ctx was added to tls_device_list.
1281          */
1282         down_read(&device_offload_lock);
1283         if (!(netdev->flags & IFF_UP)) {
1284                 rc = -EINVAL;
1285                 goto release_lock;
1286         }
1287
1288         context = kzalloc(TLS_OFFLOAD_CONTEXT_SIZE_RX, GFP_KERNEL);
1289         if (!context) {
1290                 rc = -ENOMEM;
1291                 goto release_lock;
1292         }
1293         context->resync_nh_reset = 1;
1294
1295         ctx->priv_ctx_rx = context;
1296         rc = tls_set_sw_offload(sk, ctx, 0);
1297         if (rc)
1298                 goto release_ctx;
1299
1300         rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_RX,
1301                                              &ctx->crypto_recv.info,
1302                                              tcp_sk(sk)->copied_seq);
1303         info = (void *)&ctx->crypto_recv.info;
1304         trace_tls_device_offload_set(sk, TLS_OFFLOAD_CTX_DIR_RX,
1305                                      tcp_sk(sk)->copied_seq, info->rec_seq, rc);
1306         if (rc)
1307                 goto free_sw_resources;
1308
1309         tls_device_attach(ctx, sk, netdev);
1310         up_read(&device_offload_lock);
1311
1312         dev_put(netdev);
1313
1314         return 0;
1315
1316 free_sw_resources:
1317         up_read(&device_offload_lock);
1318         tls_sw_free_resources_rx(sk);
1319         down_read(&device_offload_lock);
1320 release_ctx:
1321         ctx->priv_ctx_rx = NULL;
1322 release_lock:
1323         up_read(&device_offload_lock);
1324 release_netdev:
1325         dev_put(netdev);
1326         return rc;
1327 }
1328
1329 void tls_device_offload_cleanup_rx(struct sock *sk)
1330 {
1331         struct tls_context *tls_ctx = tls_get_ctx(sk);
1332         struct net_device *netdev;
1333
1334         down_read(&device_offload_lock);
1335         netdev = rcu_dereference_protected(tls_ctx->netdev,
1336                                            lockdep_is_held(&device_offload_lock));
1337         if (!netdev)
1338                 goto out;
1339
1340         netdev->tlsdev_ops->tls_dev_del(netdev, tls_ctx,
1341                                         TLS_OFFLOAD_CTX_DIR_RX);
1342
1343         if (tls_ctx->tx_conf != TLS_HW) {
1344                 dev_put(netdev);
1345                 rcu_assign_pointer(tls_ctx->netdev, NULL);
1346         } else {
1347                 set_bit(TLS_RX_DEV_CLOSED, &tls_ctx->flags);
1348         }
1349 out:
1350         up_read(&device_offload_lock);
1351         tls_sw_release_resources_rx(sk);
1352 }
1353
1354 static int tls_device_down(struct net_device *netdev)
1355 {
1356         struct tls_context *ctx, *tmp;
1357         unsigned long flags;
1358         LIST_HEAD(list);
1359
1360         /* Request a write lock to block new offload attempts */
1361         down_write(&device_offload_lock);
1362
1363         spin_lock_irqsave(&tls_device_lock, flags);
1364         list_for_each_entry_safe(ctx, tmp, &tls_device_list, list) {
1365                 struct net_device *ctx_netdev =
1366                         rcu_dereference_protected(ctx->netdev,
1367                                                   lockdep_is_held(&device_offload_lock));
1368
1369                 if (ctx_netdev != netdev ||
1370                     !refcount_inc_not_zero(&ctx->refcount))
1371                         continue;
1372
1373                 list_move(&ctx->list, &list);
1374         }
1375         spin_unlock_irqrestore(&tls_device_lock, flags);
1376
1377         list_for_each_entry_safe(ctx, tmp, &list, list) {
1378                 /* Stop offloaded TX and switch to the fallback.
1379                  * tls_is_sk_tx_device_offloaded will return false.
1380                  */
1381                 WRITE_ONCE(ctx->sk->sk_validate_xmit_skb, tls_validate_xmit_skb_sw);
1382
1383                 /* Stop the RX and TX resync.
1384                  * tls_dev_resync must not be called after tls_dev_del.
1385                  */
1386                 rcu_assign_pointer(ctx->netdev, NULL);
1387
1388                 /* Start skipping the RX resync logic completely. */
1389                 set_bit(TLS_RX_DEV_DEGRADED, &ctx->flags);
1390
1391                 /* Sync with inflight packets. After this point:
1392                  * TX: no non-encrypted packets will be passed to the driver.
1393                  * RX: resync requests from the driver will be ignored.
1394                  */
1395                 synchronize_net();
1396
1397                 /* Release the offload context on the driver side. */
1398                 if (ctx->tx_conf == TLS_HW)
1399                         netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
1400                                                         TLS_OFFLOAD_CTX_DIR_TX);
1401                 if (ctx->rx_conf == TLS_HW &&
1402                     !test_bit(TLS_RX_DEV_CLOSED, &ctx->flags))
1403                         netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
1404                                                         TLS_OFFLOAD_CTX_DIR_RX);
1405
1406                 dev_put(netdev);
1407
1408                 /* Move the context to a separate list for two reasons:
1409                  * 1. When the context is deallocated, list_del is called.
1410                  * 2. It's no longer an offloaded context, so we don't want to
1411                  *    run offload-specific code on this context.
1412                  */
1413                 spin_lock_irqsave(&tls_device_lock, flags);
1414                 list_move_tail(&ctx->list, &tls_device_down_list);
1415                 spin_unlock_irqrestore(&tls_device_lock, flags);
1416
1417                 /* Device contexts for RX and TX will be freed in on sk_destruct
1418                  * by tls_device_free_ctx. rx_conf and tx_conf stay in TLS_HW.
1419                  * Now release the ref taken above.
1420                  */
1421                 if (refcount_dec_and_test(&ctx->refcount)) {
1422                         /* sk_destruct ran after tls_device_down took a ref, and
1423                          * it returned early. Complete the destruction here.
1424                          */
1425                         list_del(&ctx->list);
1426                         tls_device_free_ctx(ctx);
1427                 }
1428         }
1429
1430         up_write(&device_offload_lock);
1431
1432         flush_workqueue(destruct_wq);
1433
1434         return NOTIFY_DONE;
1435 }
1436
1437 static int tls_dev_event(struct notifier_block *this, unsigned long event,
1438                          void *ptr)
1439 {
1440         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1441
1442         if (!dev->tlsdev_ops &&
1443             !(dev->features & (NETIF_F_HW_TLS_RX | NETIF_F_HW_TLS_TX)))
1444                 return NOTIFY_DONE;
1445
1446         switch (event) {
1447         case NETDEV_REGISTER:
1448         case NETDEV_FEAT_CHANGE:
1449                 if (netif_is_bond_master(dev))
1450                         return NOTIFY_DONE;
1451                 if ((dev->features & NETIF_F_HW_TLS_RX) &&
1452                     !dev->tlsdev_ops->tls_dev_resync)
1453                         return NOTIFY_BAD;
1454
1455                 if  (dev->tlsdev_ops &&
1456                      dev->tlsdev_ops->tls_dev_add &&
1457                      dev->tlsdev_ops->tls_dev_del)
1458                         return NOTIFY_DONE;
1459                 else
1460                         return NOTIFY_BAD;
1461         case NETDEV_DOWN:
1462                 return tls_device_down(dev);
1463         }
1464         return NOTIFY_DONE;
1465 }
1466
1467 static struct notifier_block tls_dev_notifier = {
1468         .notifier_call  = tls_dev_event,
1469 };
1470
1471 int __init tls_device_init(void)
1472 {
1473         int err;
1474
1475         destruct_wq = alloc_workqueue("ktls_device_destruct", 0, 0);
1476         if (!destruct_wq)
1477                 return -ENOMEM;
1478
1479         err = register_netdevice_notifier(&tls_dev_notifier);
1480         if (err)
1481                 destroy_workqueue(destruct_wq);
1482
1483         return err;
1484 }
1485
1486 void __exit tls_device_cleanup(void)
1487 {
1488         unregister_netdevice_notifier(&tls_dev_notifier);
1489         destroy_workqueue(destruct_wq);
1490         clean_acked_data_flush();
1491 }