Linux Audio

Check our new training course

Loading...
Note: File does not exist in v3.15.
   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#include <linux/skbuff_ref.h>
  41
  42#include "tls.h"
  43#include "trace.h"
  44
  45/* device_offload_lock is used to synchronize tls_dev_add
  46 * against NETDEV_DOWN notifications.
  47 */
  48static DECLARE_RWSEM(device_offload_lock);
  49
  50static struct workqueue_struct *destruct_wq __read_mostly;
  51
  52static LIST_HEAD(tls_device_list);
  53static LIST_HEAD(tls_device_down_list);
  54static DEFINE_SPINLOCK(tls_device_lock);
  55
  56static struct page *dummy_page;
  57
  58static void tls_device_free_ctx(struct tls_context *ctx)
  59{
  60	if (ctx->tx_conf == TLS_HW)
  61		kfree(tls_offload_ctx_tx(ctx));
  62
  63	if (ctx->rx_conf == TLS_HW)
  64		kfree(tls_offload_ctx_rx(ctx));
  65
  66	tls_ctx_free(NULL, ctx);
  67}
  68
  69static 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
  88static 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 */
 124static 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
 139static 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
 148static 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
 160static 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 */
 195void 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}
 212EXPORT_SYMBOL_GPL(tls_device_sk_destruct);
 213
 214void 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
 221void 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}
 228EXPORT_SYMBOL_GPL(tls_offload_tx_resync_request);
 229
 230static void tls_device_resync_tx(struct sock *sk, struct tls_context *tls_ctx,
 231				 u32 seq)
 232{
 233	struct net_device *netdev;
 234	int err = 0;
 235	u8 *rcd_sn;
 236
 237	tcp_write_collapse_fence(sk);
 238	rcd_sn = tls_ctx->tx.rec_seq;
 239
 240	trace_tls_device_tx_resync_send(sk, seq, rcd_sn);
 241	down_read(&device_offload_lock);
 242	netdev = rcu_dereference_protected(tls_ctx->netdev,
 243					   lockdep_is_held(&device_offload_lock));
 244	if (netdev)
 245		err = netdev->tlsdev_ops->tls_dev_resync(netdev, sk, seq,
 246							 rcd_sn,
 247							 TLS_OFFLOAD_CTX_DIR_TX);
 248	up_read(&device_offload_lock);
 249	if (err)
 250		return;
 251
 252	clear_bit_unlock(TLS_TX_SYNC_SCHED, &tls_ctx->flags);
 253}
 254
 255static void tls_append_frag(struct tls_record_info *record,
 256			    struct page_frag *pfrag,
 257			    int size)
 258{
 259	skb_frag_t *frag;
 260
 261	frag = &record->frags[record->num_frags - 1];
 262	if (skb_frag_page(frag) == pfrag->page &&
 263	    skb_frag_off(frag) + skb_frag_size(frag) == pfrag->offset) {
 264		skb_frag_size_add(frag, size);
 265	} else {
 266		++frag;
 267		skb_frag_fill_page_desc(frag, pfrag->page, pfrag->offset,
 268					size);
 269		++record->num_frags;
 270		get_page(pfrag->page);
 271	}
 272
 273	pfrag->offset += size;
 274	record->len += size;
 275}
 276
 277static int tls_push_record(struct sock *sk,
 278			   struct tls_context *ctx,
 279			   struct tls_offload_context_tx *offload_ctx,
 280			   struct tls_record_info *record,
 281			   int flags)
 282{
 283	struct tls_prot_info *prot = &ctx->prot_info;
 284	struct tcp_sock *tp = tcp_sk(sk);
 285	skb_frag_t *frag;
 286	int i;
 287
 288	record->end_seq = tp->write_seq + record->len;
 289	list_add_tail_rcu(&record->list, &offload_ctx->records_list);
 290	offload_ctx->open_record = NULL;
 291
 292	if (test_bit(TLS_TX_SYNC_SCHED, &ctx->flags))
 293		tls_device_resync_tx(sk, ctx, tp->write_seq);
 294
 295	tls_advance_record_sn(sk, prot, &ctx->tx);
 296
 297	for (i = 0; i < record->num_frags; i++) {
 298		frag = &record->frags[i];
 299		sg_unmark_end(&offload_ctx->sg_tx_data[i]);
 300		sg_set_page(&offload_ctx->sg_tx_data[i], skb_frag_page(frag),
 301			    skb_frag_size(frag), skb_frag_off(frag));
 302		sk_mem_charge(sk, skb_frag_size(frag));
 303		get_page(skb_frag_page(frag));
 304	}
 305	sg_mark_end(&offload_ctx->sg_tx_data[record->num_frags - 1]);
 306
 307	/* all ready, send */
 308	return tls_push_sg(sk, ctx, offload_ctx->sg_tx_data, 0, flags);
 309}
 310
 311static void tls_device_record_close(struct sock *sk,
 312				    struct tls_context *ctx,
 313				    struct tls_record_info *record,
 314				    struct page_frag *pfrag,
 315				    unsigned char record_type)
 316{
 317	struct tls_prot_info *prot = &ctx->prot_info;
 318	struct page_frag dummy_tag_frag;
 319
 320	/* append tag
 321	 * device will fill in the tag, we just need to append a placeholder
 322	 * use socket memory to improve coalescing (re-using a single buffer
 323	 * increases frag count)
 324	 * if we can't allocate memory now use the dummy page
 325	 */
 326	if (unlikely(pfrag->size - pfrag->offset < prot->tag_size) &&
 327	    !skb_page_frag_refill(prot->tag_size, pfrag, sk->sk_allocation)) {
 328		dummy_tag_frag.page = dummy_page;
 329		dummy_tag_frag.offset = 0;
 330		pfrag = &dummy_tag_frag;
 331	}
 332	tls_append_frag(record, pfrag, prot->tag_size);
 333
 334	/* fill prepend */
 335	tls_fill_prepend(ctx, skb_frag_address(&record->frags[0]),
 336			 record->len - prot->overhead_size,
 337			 record_type);
 338}
 339
 340static int tls_create_new_record(struct tls_offload_context_tx *offload_ctx,
 341				 struct page_frag *pfrag,
 342				 size_t prepend_size)
 343{
 344	struct tls_record_info *record;
 345	skb_frag_t *frag;
 346
 347	record = kmalloc(sizeof(*record), GFP_KERNEL);
 348	if (!record)
 349		return -ENOMEM;
 350
 351	frag = &record->frags[0];
 352	skb_frag_fill_page_desc(frag, pfrag->page, pfrag->offset,
 353				prepend_size);
 354
 355	get_page(pfrag->page);
 356	pfrag->offset += prepend_size;
 357
 358	record->num_frags = 1;
 359	record->len = prepend_size;
 360	offload_ctx->open_record = record;
 361	return 0;
 362}
 363
 364static int tls_do_allocation(struct sock *sk,
 365			     struct tls_offload_context_tx *offload_ctx,
 366			     struct page_frag *pfrag,
 367			     size_t prepend_size)
 368{
 369	int ret;
 370
 371	if (!offload_ctx->open_record) {
 372		if (unlikely(!skb_page_frag_refill(prepend_size, pfrag,
 373						   sk->sk_allocation))) {
 374			READ_ONCE(sk->sk_prot)->enter_memory_pressure(sk);
 375			sk_stream_moderate_sndbuf(sk);
 376			return -ENOMEM;
 377		}
 378
 379		ret = tls_create_new_record(offload_ctx, pfrag, prepend_size);
 380		if (ret)
 381			return ret;
 382
 383		if (pfrag->size > pfrag->offset)
 384			return 0;
 385	}
 386
 387	if (!sk_page_frag_refill(sk, pfrag))
 388		return -ENOMEM;
 389
 390	return 0;
 391}
 392
 393static int tls_device_copy_data(void *addr, size_t bytes, struct iov_iter *i)
 394{
 395	size_t pre_copy, nocache;
 396
 397	pre_copy = ~((unsigned long)addr - 1) & (SMP_CACHE_BYTES - 1);
 398	if (pre_copy) {
 399		pre_copy = min(pre_copy, bytes);
 400		if (copy_from_iter(addr, pre_copy, i) != pre_copy)
 401			return -EFAULT;
 402		bytes -= pre_copy;
 403		addr += pre_copy;
 404	}
 405
 406	nocache = round_down(bytes, SMP_CACHE_BYTES);
 407	if (copy_from_iter_nocache(addr, nocache, i) != nocache)
 408		return -EFAULT;
 409	bytes -= nocache;
 410	addr += nocache;
 411
 412	if (bytes && copy_from_iter(addr, bytes, i) != bytes)
 413		return -EFAULT;
 414
 415	return 0;
 416}
 417
 418static int tls_push_data(struct sock *sk,
 419			 struct iov_iter *iter,
 420			 size_t size, int flags,
 421			 unsigned char record_type)
 422{
 423	struct tls_context *tls_ctx = tls_get_ctx(sk);
 424	struct tls_prot_info *prot = &tls_ctx->prot_info;
 425	struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
 426	struct tls_record_info *record;
 427	int tls_push_record_flags;
 428	struct page_frag *pfrag;
 429	size_t orig_size = size;
 430	u32 max_open_record_len;
 431	bool more = false;
 432	bool done = false;
 433	int copy, rc = 0;
 434	long timeo;
 435
 436	if (flags &
 437	    ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL |
 438	      MSG_SPLICE_PAGES | MSG_EOR))
 439		return -EOPNOTSUPP;
 440
 441	if ((flags & (MSG_MORE | MSG_EOR)) == (MSG_MORE | MSG_EOR))
 442		return -EINVAL;
 443
 444	if (unlikely(sk->sk_err))
 445		return -sk->sk_err;
 446
 447	flags |= MSG_SENDPAGE_DECRYPTED;
 448	tls_push_record_flags = flags | MSG_MORE;
 449
 450	timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
 451	if (tls_is_partially_sent_record(tls_ctx)) {
 452		rc = tls_push_partial_record(sk, tls_ctx, flags);
 453		if (rc < 0)
 454			return rc;
 455	}
 456
 457	pfrag = sk_page_frag(sk);
 458
 459	/* TLS_HEADER_SIZE is not counted as part of the TLS record, and
 460	 * we need to leave room for an authentication tag.
 461	 */
 462	max_open_record_len = TLS_MAX_PAYLOAD_SIZE +
 463			      prot->prepend_size;
 464	do {
 465		rc = tls_do_allocation(sk, ctx, pfrag, prot->prepend_size);
 466		if (unlikely(rc)) {
 467			rc = sk_stream_wait_memory(sk, &timeo);
 468			if (!rc)
 469				continue;
 470
 471			record = ctx->open_record;
 472			if (!record)
 473				break;
 474handle_error:
 475			if (record_type != TLS_RECORD_TYPE_DATA) {
 476				/* avoid sending partial
 477				 * record with type !=
 478				 * application_data
 479				 */
 480				size = orig_size;
 481				destroy_record(record);
 482				ctx->open_record = NULL;
 483			} else if (record->len > prot->prepend_size) {
 484				goto last_record;
 485			}
 486
 487			break;
 488		}
 489
 490		record = ctx->open_record;
 491
 492		copy = min_t(size_t, size, max_open_record_len - record->len);
 493		if (copy && (flags & MSG_SPLICE_PAGES)) {
 494			struct page_frag zc_pfrag;
 495			struct page **pages = &zc_pfrag.page;
 496			size_t off;
 497
 498			rc = iov_iter_extract_pages(iter, &pages,
 499						    copy, 1, 0, &off);
 500			if (rc <= 0) {
 501				if (rc == 0)
 502					rc = -EIO;
 503				goto handle_error;
 504			}
 505			copy = rc;
 506
 507			if (WARN_ON_ONCE(!sendpage_ok(zc_pfrag.page))) {
 508				iov_iter_revert(iter, copy);
 509				rc = -EIO;
 510				goto handle_error;
 511			}
 512
 513			zc_pfrag.offset = off;
 514			zc_pfrag.size = copy;
 515			tls_append_frag(record, &zc_pfrag, copy);
 516		} else if (copy) {
 517			copy = min_t(size_t, copy, pfrag->size - pfrag->offset);
 518
 519			rc = tls_device_copy_data(page_address(pfrag->page) +
 520						  pfrag->offset, copy,
 521						  iter);
 522			if (rc)
 523				goto handle_error;
 524			tls_append_frag(record, pfrag, copy);
 525		}
 526
 527		size -= copy;
 528		if (!size) {
 529last_record:
 530			tls_push_record_flags = flags;
 531			if (flags & MSG_MORE) {
 532				more = true;
 533				break;
 534			}
 535
 536			done = true;
 537		}
 538
 539		if (done || record->len >= max_open_record_len ||
 540		    (record->num_frags >= MAX_SKB_FRAGS - 1)) {
 541			tls_device_record_close(sk, tls_ctx, record,
 542						pfrag, record_type);
 543
 544			rc = tls_push_record(sk,
 545					     tls_ctx,
 546					     ctx,
 547					     record,
 548					     tls_push_record_flags);
 549			if (rc < 0)
 550				break;
 551		}
 552	} while (!done);
 553
 554	tls_ctx->pending_open_record_frags = more;
 555
 556	if (orig_size - size > 0)
 557		rc = orig_size - size;
 558
 559	return rc;
 560}
 561
 562int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
 563{
 564	unsigned char record_type = TLS_RECORD_TYPE_DATA;
 565	struct tls_context *tls_ctx = tls_get_ctx(sk);
 566	int rc;
 567
 568	if (!tls_ctx->zerocopy_sendfile)
 569		msg->msg_flags &= ~MSG_SPLICE_PAGES;
 570
 571	mutex_lock(&tls_ctx->tx_lock);
 572	lock_sock(sk);
 573
 574	if (unlikely(msg->msg_controllen)) {
 575		rc = tls_process_cmsg(sk, msg, &record_type);
 576		if (rc)
 577			goto out;
 578	}
 579
 580	rc = tls_push_data(sk, &msg->msg_iter, size, msg->msg_flags,
 581			   record_type);
 582
 583out:
 584	release_sock(sk);
 585	mutex_unlock(&tls_ctx->tx_lock);
 586	return rc;
 587}
 588
 589void tls_device_splice_eof(struct socket *sock)
 590{
 591	struct sock *sk = sock->sk;
 592	struct tls_context *tls_ctx = tls_get_ctx(sk);
 593	struct iov_iter iter = {};
 594
 595	if (!tls_is_partially_sent_record(tls_ctx))
 596		return;
 597
 598	mutex_lock(&tls_ctx->tx_lock);
 599	lock_sock(sk);
 600
 601	if (tls_is_partially_sent_record(tls_ctx)) {
 602		iov_iter_bvec(&iter, ITER_SOURCE, NULL, 0, 0);
 603		tls_push_data(sk, &iter, 0, 0, TLS_RECORD_TYPE_DATA);
 604	}
 605
 606	release_sock(sk);
 607	mutex_unlock(&tls_ctx->tx_lock);
 608}
 609
 610struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context,
 611				       u32 seq, u64 *p_record_sn)
 612{
 613	u64 record_sn = context->hint_record_sn;
 614	struct tls_record_info *info, *last;
 615
 616	info = context->retransmit_hint;
 617	if (!info ||
 618	    before(seq, info->end_seq - info->len)) {
 619		/* if retransmit_hint is irrelevant start
 620		 * from the beginning of the list
 621		 */
 622		info = list_first_entry_or_null(&context->records_list,
 623						struct tls_record_info, list);
 624		if (!info)
 625			return NULL;
 626		/* send the start_marker record if seq number is before the
 627		 * tls offload start marker sequence number. This record is
 628		 * required to handle TCP packets which are before TLS offload
 629		 * started.
 630		 *  And if it's not start marker, look if this seq number
 631		 * belongs to the list.
 632		 */
 633		if (likely(!tls_record_is_start_marker(info))) {
 634			/* we have the first record, get the last record to see
 635			 * if this seq number belongs to the list.
 636			 */
 637			last = list_last_entry(&context->records_list,
 638					       struct tls_record_info, list);
 639
 640			if (!between(seq, tls_record_start_seq(info),
 641				     last->end_seq))
 642				return NULL;
 643		}
 644		record_sn = context->unacked_record_sn;
 645	}
 646
 647	/* We just need the _rcu for the READ_ONCE() */
 648	rcu_read_lock();
 649	list_for_each_entry_from_rcu(info, &context->records_list, list) {
 650		if (before(seq, info->end_seq)) {
 651			if (!context->retransmit_hint ||
 652			    after(info->end_seq,
 653				  context->retransmit_hint->end_seq)) {
 654				context->hint_record_sn = record_sn;
 655				context->retransmit_hint = info;
 656			}
 657			*p_record_sn = record_sn;
 658			goto exit_rcu_unlock;
 659		}
 660		record_sn++;
 661	}
 662	info = NULL;
 663
 664exit_rcu_unlock:
 665	rcu_read_unlock();
 666	return info;
 667}
 668EXPORT_SYMBOL(tls_get_record);
 669
 670static int tls_device_push_pending_record(struct sock *sk, int flags)
 671{
 672	struct iov_iter iter;
 673
 674	iov_iter_kvec(&iter, ITER_SOURCE, NULL, 0, 0);
 675	return tls_push_data(sk, &iter, 0, flags, TLS_RECORD_TYPE_DATA);
 676}
 677
 678void tls_device_write_space(struct sock *sk, struct tls_context *ctx)
 679{
 680	if (tls_is_partially_sent_record(ctx)) {
 681		gfp_t sk_allocation = sk->sk_allocation;
 682
 683		WARN_ON_ONCE(sk->sk_write_pending);
 684
 685		sk->sk_allocation = GFP_ATOMIC;
 686		tls_push_partial_record(sk, ctx,
 687					MSG_DONTWAIT | MSG_NOSIGNAL |
 688					MSG_SENDPAGE_DECRYPTED);
 689		sk->sk_allocation = sk_allocation;
 690	}
 691}
 692
 693static void tls_device_resync_rx(struct tls_context *tls_ctx,
 694				 struct sock *sk, u32 seq, u8 *rcd_sn)
 695{
 696	struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
 697	struct net_device *netdev;
 698
 699	trace_tls_device_rx_resync_send(sk, seq, rcd_sn, rx_ctx->resync_type);
 700	rcu_read_lock();
 701	netdev = rcu_dereference(tls_ctx->netdev);
 702	if (netdev)
 703		netdev->tlsdev_ops->tls_dev_resync(netdev, sk, seq, rcd_sn,
 704						   TLS_OFFLOAD_CTX_DIR_RX);
 705	rcu_read_unlock();
 706	TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSRXDEVICERESYNC);
 707}
 708
 709static bool
 710tls_device_rx_resync_async(struct tls_offload_resync_async *resync_async,
 711			   s64 resync_req, u32 *seq, u16 *rcd_delta)
 712{
 713	u32 is_async = resync_req & RESYNC_REQ_ASYNC;
 714	u32 req_seq = resync_req >> 32;
 715	u32 req_end = req_seq + ((resync_req >> 16) & 0xffff);
 716	u16 i;
 717
 718	*rcd_delta = 0;
 719
 720	if (is_async) {
 721		/* shouldn't get to wraparound:
 722		 * too long in async stage, something bad happened
 723		 */
 724		if (WARN_ON_ONCE(resync_async->rcd_delta == USHRT_MAX))
 725			return false;
 726
 727		/* asynchronous stage: log all headers seq such that
 728		 * req_seq <= seq <= end_seq, and wait for real resync request
 729		 */
 730		if (before(*seq, req_seq))
 731			return false;
 732		if (!after(*seq, req_end) &&
 733		    resync_async->loglen < TLS_DEVICE_RESYNC_ASYNC_LOGMAX)
 734			resync_async->log[resync_async->loglen++] = *seq;
 735
 736		resync_async->rcd_delta++;
 737
 738		return false;
 739	}
 740
 741	/* synchronous stage: check against the logged entries and
 742	 * proceed to check the next entries if no match was found
 743	 */
 744	for (i = 0; i < resync_async->loglen; i++)
 745		if (req_seq == resync_async->log[i] &&
 746		    atomic64_try_cmpxchg(&resync_async->req, &resync_req, 0)) {
 747			*rcd_delta = resync_async->rcd_delta - i;
 748			*seq = req_seq;
 749			resync_async->loglen = 0;
 750			resync_async->rcd_delta = 0;
 751			return true;
 752		}
 753
 754	resync_async->loglen = 0;
 755	resync_async->rcd_delta = 0;
 756
 757	if (req_seq == *seq &&
 758	    atomic64_try_cmpxchg(&resync_async->req,
 759				 &resync_req, 0))
 760		return true;
 761
 762	return false;
 763}
 764
 765void tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq)
 766{
 767	struct tls_context *tls_ctx = tls_get_ctx(sk);
 768	struct tls_offload_context_rx *rx_ctx;
 769	u8 rcd_sn[TLS_MAX_REC_SEQ_SIZE];
 770	u32 sock_data, is_req_pending;
 771	struct tls_prot_info *prot;
 772	s64 resync_req;
 773	u16 rcd_delta;
 774	u32 req_seq;
 775
 776	if (tls_ctx->rx_conf != TLS_HW)
 777		return;
 778	if (unlikely(test_bit(TLS_RX_DEV_DEGRADED, &tls_ctx->flags)))
 779		return;
 780
 781	prot = &tls_ctx->prot_info;
 782	rx_ctx = tls_offload_ctx_rx(tls_ctx);
 783	memcpy(rcd_sn, tls_ctx->rx.rec_seq, prot->rec_seq_size);
 784
 785	switch (rx_ctx->resync_type) {
 786	case TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ:
 787		resync_req = atomic64_read(&rx_ctx->resync_req);
 788		req_seq = resync_req >> 32;
 789		seq += TLS_HEADER_SIZE - 1;
 790		is_req_pending = resync_req;
 791
 792		if (likely(!is_req_pending) || req_seq != seq ||
 793		    !atomic64_try_cmpxchg(&rx_ctx->resync_req, &resync_req, 0))
 794			return;
 795		break;
 796	case TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT:
 797		if (likely(!rx_ctx->resync_nh_do_now))
 798			return;
 799
 800		/* head of next rec is already in, note that the sock_inq will
 801		 * include the currently parsed message when called from parser
 802		 */
 803		sock_data = tcp_inq(sk);
 804		if (sock_data > rcd_len) {
 805			trace_tls_device_rx_resync_nh_delay(sk, sock_data,
 806							    rcd_len);
 807			return;
 808		}
 809
 810		rx_ctx->resync_nh_do_now = 0;
 811		seq += rcd_len;
 812		tls_bigint_increment(rcd_sn, prot->rec_seq_size);
 813		break;
 814	case TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ_ASYNC:
 815		resync_req = atomic64_read(&rx_ctx->resync_async->req);
 816		is_req_pending = resync_req;
 817		if (likely(!is_req_pending))
 818			return;
 819
 820		if (!tls_device_rx_resync_async(rx_ctx->resync_async,
 821						resync_req, &seq, &rcd_delta))
 822			return;
 823		tls_bigint_subtract(rcd_sn, rcd_delta);
 824		break;
 825	}
 826
 827	tls_device_resync_rx(tls_ctx, sk, seq, rcd_sn);
 828}
 829
 830static void tls_device_core_ctrl_rx_resync(struct tls_context *tls_ctx,
 831					   struct tls_offload_context_rx *ctx,
 832					   struct sock *sk, struct sk_buff *skb)
 833{
 834	struct strp_msg *rxm;
 835
 836	/* device will request resyncs by itself based on stream scan */
 837	if (ctx->resync_type != TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT)
 838		return;
 839	/* already scheduled */
 840	if (ctx->resync_nh_do_now)
 841		return;
 842	/* seen decrypted fragments since last fully-failed record */
 843	if (ctx->resync_nh_reset) {
 844		ctx->resync_nh_reset = 0;
 845		ctx->resync_nh.decrypted_failed = 1;
 846		ctx->resync_nh.decrypted_tgt = TLS_DEVICE_RESYNC_NH_START_IVAL;
 847		return;
 848	}
 849
 850	if (++ctx->resync_nh.decrypted_failed <= ctx->resync_nh.decrypted_tgt)
 851		return;
 852
 853	/* doing resync, bump the next target in case it fails */
 854	if (ctx->resync_nh.decrypted_tgt < TLS_DEVICE_RESYNC_NH_MAX_IVAL)
 855		ctx->resync_nh.decrypted_tgt *= 2;
 856	else
 857		ctx->resync_nh.decrypted_tgt += TLS_DEVICE_RESYNC_NH_MAX_IVAL;
 858
 859	rxm = strp_msg(skb);
 860
 861	/* head of next rec is already in, parser will sync for us */
 862	if (tcp_inq(sk) > rxm->full_len) {
 863		trace_tls_device_rx_resync_nh_schedule(sk);
 864		ctx->resync_nh_do_now = 1;
 865	} else {
 866		struct tls_prot_info *prot = &tls_ctx->prot_info;
 867		u8 rcd_sn[TLS_MAX_REC_SEQ_SIZE];
 868
 869		memcpy(rcd_sn, tls_ctx->rx.rec_seq, prot->rec_seq_size);
 870		tls_bigint_increment(rcd_sn, prot->rec_seq_size);
 871
 872		tls_device_resync_rx(tls_ctx, sk, tcp_sk(sk)->copied_seq,
 873				     rcd_sn);
 874	}
 875}
 876
 877static int
 878tls_device_reencrypt(struct sock *sk, struct tls_context *tls_ctx)
 879{
 880	struct tls_sw_context_rx *sw_ctx = tls_sw_ctx_rx(tls_ctx);
 881	const struct tls_cipher_desc *cipher_desc;
 882	int err, offset, copy, data_len, pos;
 883	struct sk_buff *skb, *skb_iter;
 884	struct scatterlist sg[1];
 885	struct strp_msg *rxm;
 886	char *orig_buf, *buf;
 887
 888	cipher_desc = get_cipher_desc(tls_ctx->crypto_recv.info.cipher_type);
 889	DEBUG_NET_WARN_ON_ONCE(!cipher_desc || !cipher_desc->offloadable);
 890
 891	rxm = strp_msg(tls_strp_msg(sw_ctx));
 892	orig_buf = kmalloc(rxm->full_len + TLS_HEADER_SIZE + cipher_desc->iv,
 893			   sk->sk_allocation);
 894	if (!orig_buf)
 895		return -ENOMEM;
 896	buf = orig_buf;
 897
 898	err = tls_strp_msg_cow(sw_ctx);
 899	if (unlikely(err))
 900		goto free_buf;
 901
 902	skb = tls_strp_msg(sw_ctx);
 903	rxm = strp_msg(skb);
 904	offset = rxm->offset;
 905
 906	sg_init_table(sg, 1);
 907	sg_set_buf(&sg[0], buf,
 908		   rxm->full_len + TLS_HEADER_SIZE + cipher_desc->iv);
 909	err = skb_copy_bits(skb, offset, buf, TLS_HEADER_SIZE + cipher_desc->iv);
 910	if (err)
 911		goto free_buf;
 912
 913	/* We are interested only in the decrypted data not the auth */
 914	err = decrypt_skb(sk, sg);
 915	if (err != -EBADMSG)
 916		goto free_buf;
 917	else
 918		err = 0;
 919
 920	data_len = rxm->full_len - cipher_desc->tag;
 921
 922	if (skb_pagelen(skb) > offset) {
 923		copy = min_t(int, skb_pagelen(skb) - offset, data_len);
 924
 925		if (skb->decrypted) {
 926			err = skb_store_bits(skb, offset, buf, copy);
 927			if (err)
 928				goto free_buf;
 929		}
 930
 931		offset += copy;
 932		buf += copy;
 933	}
 934
 935	pos = skb_pagelen(skb);
 936	skb_walk_frags(skb, skb_iter) {
 937		int frag_pos;
 938
 939		/* Practically all frags must belong to msg if reencrypt
 940		 * is needed with current strparser and coalescing logic,
 941		 * but strparser may "get optimized", so let's be safe.
 942		 */
 943		if (pos + skb_iter->len <= offset)
 944			goto done_with_frag;
 945		if (pos >= data_len + rxm->offset)
 946			break;
 947
 948		frag_pos = offset - pos;
 949		copy = min_t(int, skb_iter->len - frag_pos,
 950			     data_len + rxm->offset - offset);
 951
 952		if (skb_iter->decrypted) {
 953			err = skb_store_bits(skb_iter, frag_pos, buf, copy);
 954			if (err)
 955				goto free_buf;
 956		}
 957
 958		offset += copy;
 959		buf += copy;
 960done_with_frag:
 961		pos += skb_iter->len;
 962	}
 963
 964free_buf:
 965	kfree(orig_buf);
 966	return err;
 967}
 968
 969int tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx)
 970{
 971	struct tls_offload_context_rx *ctx = tls_offload_ctx_rx(tls_ctx);
 972	struct tls_sw_context_rx *sw_ctx = tls_sw_ctx_rx(tls_ctx);
 973	struct sk_buff *skb = tls_strp_msg(sw_ctx);
 974	struct strp_msg *rxm = strp_msg(skb);
 975	int is_decrypted, is_encrypted;
 976
 977	if (!tls_strp_msg_mixed_decrypted(sw_ctx)) {
 978		is_decrypted = skb->decrypted;
 979		is_encrypted = !is_decrypted;
 980	} else {
 981		is_decrypted = 0;
 982		is_encrypted = 0;
 983	}
 984
 985	trace_tls_device_decrypted(sk, tcp_sk(sk)->copied_seq - rxm->full_len,
 986				   tls_ctx->rx.rec_seq, rxm->full_len,
 987				   is_encrypted, is_decrypted);
 988
 989	if (unlikely(test_bit(TLS_RX_DEV_DEGRADED, &tls_ctx->flags))) {
 990		if (likely(is_encrypted || is_decrypted))
 991			return is_decrypted;
 992
 993		/* After tls_device_down disables the offload, the next SKB will
 994		 * likely have initial fragments decrypted, and final ones not
 995		 * decrypted. We need to reencrypt that single SKB.
 996		 */
 997		return tls_device_reencrypt(sk, tls_ctx);
 998	}
 999
1000	/* Return immediately if the record is either entirely plaintext or
1001	 * entirely ciphertext. Otherwise handle reencrypt partially decrypted
1002	 * record.
1003	 */
1004	if (is_decrypted) {
1005		ctx->resync_nh_reset = 1;
1006		return is_decrypted;
1007	}
1008	if (is_encrypted) {
1009		tls_device_core_ctrl_rx_resync(tls_ctx, ctx, sk, skb);
1010		return 0;
1011	}
1012
1013	ctx->resync_nh_reset = 1;
1014	return tls_device_reencrypt(sk, tls_ctx);
1015}
1016
1017static void tls_device_attach(struct tls_context *ctx, struct sock *sk,
1018			      struct net_device *netdev)
1019{
1020	if (sk->sk_destruct != tls_device_sk_destruct) {
1021		refcount_set(&ctx->refcount, 1);
1022		dev_hold(netdev);
1023		RCU_INIT_POINTER(ctx->netdev, netdev);
1024		spin_lock_irq(&tls_device_lock);
1025		list_add_tail(&ctx->list, &tls_device_list);
1026		spin_unlock_irq(&tls_device_lock);
1027
1028		ctx->sk_destruct = sk->sk_destruct;
1029		smp_store_release(&sk->sk_destruct, tls_device_sk_destruct);
1030	}
1031}
1032
1033static struct tls_offload_context_tx *alloc_offload_ctx_tx(struct tls_context *ctx)
1034{
1035	struct tls_offload_context_tx *offload_ctx;
1036	__be64 rcd_sn;
1037
1038	offload_ctx = kzalloc(sizeof(*offload_ctx), GFP_KERNEL);
1039	if (!offload_ctx)
1040		return NULL;
1041
1042	INIT_WORK(&offload_ctx->destruct_work, tls_device_tx_del_task);
1043	INIT_LIST_HEAD(&offload_ctx->records_list);
1044	spin_lock_init(&offload_ctx->lock);
1045	sg_init_table(offload_ctx->sg_tx_data,
1046		      ARRAY_SIZE(offload_ctx->sg_tx_data));
1047
1048	/* start at rec_seq - 1 to account for the start marker record */
1049	memcpy(&rcd_sn, ctx->tx.rec_seq, sizeof(rcd_sn));
1050	offload_ctx->unacked_record_sn = be64_to_cpu(rcd_sn) - 1;
1051
1052	offload_ctx->ctx = ctx;
1053
1054	return offload_ctx;
1055}
1056
1057int tls_set_device_offload(struct sock *sk)
1058{
1059	struct tls_record_info *start_marker_record;
1060	struct tls_offload_context_tx *offload_ctx;
1061	const struct tls_cipher_desc *cipher_desc;
1062	struct tls_crypto_info *crypto_info;
1063	struct tls_prot_info *prot;
1064	struct net_device *netdev;
1065	struct tls_context *ctx;
1066	char *iv, *rec_seq;
1067	int rc;
1068
1069	ctx = tls_get_ctx(sk);
1070	prot = &ctx->prot_info;
1071
1072	if (ctx->priv_ctx_tx)
1073		return -EEXIST;
1074
1075	netdev = get_netdev_for_sock(sk);
1076	if (!netdev) {
1077		pr_err_ratelimited("%s: netdev not found\n", __func__);
1078		return -EINVAL;
1079	}
1080
1081	if (!(netdev->features & NETIF_F_HW_TLS_TX)) {
1082		rc = -EOPNOTSUPP;
1083		goto release_netdev;
1084	}
1085
1086	crypto_info = &ctx->crypto_send.info;
1087	if (crypto_info->version != TLS_1_2_VERSION) {
1088		rc = -EOPNOTSUPP;
1089		goto release_netdev;
1090	}
1091
1092	cipher_desc = get_cipher_desc(crypto_info->cipher_type);
1093	if (!cipher_desc || !cipher_desc->offloadable) {
1094		rc = -EINVAL;
1095		goto release_netdev;
1096	}
1097
1098	rc = init_prot_info(prot, crypto_info, cipher_desc);
1099	if (rc)
1100		goto release_netdev;
1101
1102	iv = crypto_info_iv(crypto_info, cipher_desc);
1103	rec_seq = crypto_info_rec_seq(crypto_info, cipher_desc);
1104
1105	memcpy(ctx->tx.iv + cipher_desc->salt, iv, cipher_desc->iv);
1106	memcpy(ctx->tx.rec_seq, rec_seq, cipher_desc->rec_seq);
1107
1108	start_marker_record = kmalloc(sizeof(*start_marker_record), GFP_KERNEL);
1109	if (!start_marker_record) {
1110		rc = -ENOMEM;
1111		goto release_netdev;
1112	}
1113
1114	offload_ctx = alloc_offload_ctx_tx(ctx);
1115	if (!offload_ctx) {
1116		rc = -ENOMEM;
1117		goto free_marker_record;
1118	}
1119
1120	rc = tls_sw_fallback_init(sk, offload_ctx, crypto_info);
1121	if (rc)
1122		goto free_offload_ctx;
1123
1124	start_marker_record->end_seq = tcp_sk(sk)->write_seq;
1125	start_marker_record->len = 0;
1126	start_marker_record->num_frags = 0;
1127	list_add_tail(&start_marker_record->list, &offload_ctx->records_list);
1128
1129	clean_acked_data_enable(inet_csk(sk), &tls_icsk_clean_acked);
1130	ctx->push_pending_record = tls_device_push_pending_record;
1131
1132	/* TLS offload is greatly simplified if we don't send
1133	 * SKBs where only part of the payload needs to be encrypted.
1134	 * So mark the last skb in the write queue as end of record.
1135	 */
1136	tcp_write_collapse_fence(sk);
1137
1138	/* Avoid offloading if the device is down
1139	 * We don't want to offload new flows after
1140	 * the NETDEV_DOWN event
1141	 *
1142	 * device_offload_lock is taken in tls_devices's NETDEV_DOWN
1143	 * handler thus protecting from the device going down before
1144	 * ctx was added to tls_device_list.
1145	 */
1146	down_read(&device_offload_lock);
1147	if (!(netdev->flags & IFF_UP)) {
1148		rc = -EINVAL;
1149		goto release_lock;
1150	}
1151
1152	ctx->priv_ctx_tx = offload_ctx;
1153	rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_TX,
1154					     &ctx->crypto_send.info,
1155					     tcp_sk(sk)->write_seq);
1156	trace_tls_device_offload_set(sk, TLS_OFFLOAD_CTX_DIR_TX,
1157				     tcp_sk(sk)->write_seq, rec_seq, rc);
1158	if (rc)
1159		goto release_lock;
1160
1161	tls_device_attach(ctx, sk, netdev);
1162	up_read(&device_offload_lock);
1163
1164	/* following this assignment tls_is_skb_tx_device_offloaded
1165	 * will return true and the context might be accessed
1166	 * by the netdev's xmit function.
1167	 */
1168	smp_store_release(&sk->sk_validate_xmit_skb, tls_validate_xmit_skb);
1169	dev_put(netdev);
1170
1171	return 0;
1172
1173release_lock:
1174	up_read(&device_offload_lock);
1175	clean_acked_data_disable(inet_csk(sk));
1176	crypto_free_aead(offload_ctx->aead_send);
1177free_offload_ctx:
1178	kfree(offload_ctx);
1179	ctx->priv_ctx_tx = NULL;
1180free_marker_record:
1181	kfree(start_marker_record);
1182release_netdev:
1183	dev_put(netdev);
1184	return rc;
1185}
1186
1187int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
1188{
1189	struct tls12_crypto_info_aes_gcm_128 *info;
1190	struct tls_offload_context_rx *context;
1191	struct net_device *netdev;
1192	int rc = 0;
1193
1194	if (ctx->crypto_recv.info.version != TLS_1_2_VERSION)
1195		return -EOPNOTSUPP;
1196
1197	netdev = get_netdev_for_sock(sk);
1198	if (!netdev) {
1199		pr_err_ratelimited("%s: netdev not found\n", __func__);
1200		return -EINVAL;
1201	}
1202
1203	if (!(netdev->features & NETIF_F_HW_TLS_RX)) {
1204		rc = -EOPNOTSUPP;
1205		goto release_netdev;
1206	}
1207
1208	/* Avoid offloading if the device is down
1209	 * We don't want to offload new flows after
1210	 * the NETDEV_DOWN event
1211	 *
1212	 * device_offload_lock is taken in tls_devices's NETDEV_DOWN
1213	 * handler thus protecting from the device going down before
1214	 * ctx was added to tls_device_list.
1215	 */
1216	down_read(&device_offload_lock);
1217	if (!(netdev->flags & IFF_UP)) {
1218		rc = -EINVAL;
1219		goto release_lock;
1220	}
1221
1222	context = kzalloc(sizeof(*context), GFP_KERNEL);
1223	if (!context) {
1224		rc = -ENOMEM;
1225		goto release_lock;
1226	}
1227	context->resync_nh_reset = 1;
1228
1229	ctx->priv_ctx_rx = context;
1230	rc = tls_set_sw_offload(sk, 0);
1231	if (rc)
1232		goto release_ctx;
1233
1234	rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_RX,
1235					     &ctx->crypto_recv.info,
1236					     tcp_sk(sk)->copied_seq);
1237	info = (void *)&ctx->crypto_recv.info;
1238	trace_tls_device_offload_set(sk, TLS_OFFLOAD_CTX_DIR_RX,
1239				     tcp_sk(sk)->copied_seq, info->rec_seq, rc);
1240	if (rc)
1241		goto free_sw_resources;
1242
1243	tls_device_attach(ctx, sk, netdev);
1244	up_read(&device_offload_lock);
1245
1246	dev_put(netdev);
1247
1248	return 0;
1249
1250free_sw_resources:
1251	up_read(&device_offload_lock);
1252	tls_sw_free_resources_rx(sk);
1253	down_read(&device_offload_lock);
1254release_ctx:
1255	ctx->priv_ctx_rx = NULL;
1256release_lock:
1257	up_read(&device_offload_lock);
1258release_netdev:
1259	dev_put(netdev);
1260	return rc;
1261}
1262
1263void tls_device_offload_cleanup_rx(struct sock *sk)
1264{
1265	struct tls_context *tls_ctx = tls_get_ctx(sk);
1266	struct net_device *netdev;
1267
1268	down_read(&device_offload_lock);
1269	netdev = rcu_dereference_protected(tls_ctx->netdev,
1270					   lockdep_is_held(&device_offload_lock));
1271	if (!netdev)
1272		goto out;
1273
1274	netdev->tlsdev_ops->tls_dev_del(netdev, tls_ctx,
1275					TLS_OFFLOAD_CTX_DIR_RX);
1276
1277	if (tls_ctx->tx_conf != TLS_HW) {
1278		dev_put(netdev);
1279		rcu_assign_pointer(tls_ctx->netdev, NULL);
1280	} else {
1281		set_bit(TLS_RX_DEV_CLOSED, &tls_ctx->flags);
1282	}
1283out:
1284	up_read(&device_offload_lock);
1285	tls_sw_release_resources_rx(sk);
1286}
1287
1288static int tls_device_down(struct net_device *netdev)
1289{
1290	struct tls_context *ctx, *tmp;
1291	unsigned long flags;
1292	LIST_HEAD(list);
1293
1294	/* Request a write lock to block new offload attempts */
1295	down_write(&device_offload_lock);
1296
1297	spin_lock_irqsave(&tls_device_lock, flags);
1298	list_for_each_entry_safe(ctx, tmp, &tls_device_list, list) {
1299		struct net_device *ctx_netdev =
1300			rcu_dereference_protected(ctx->netdev,
1301						  lockdep_is_held(&device_offload_lock));
1302
1303		if (ctx_netdev != netdev ||
1304		    !refcount_inc_not_zero(&ctx->refcount))
1305			continue;
1306
1307		list_move(&ctx->list, &list);
1308	}
1309	spin_unlock_irqrestore(&tls_device_lock, flags);
1310
1311	list_for_each_entry_safe(ctx, tmp, &list, list)	{
1312		/* Stop offloaded TX and switch to the fallback.
1313		 * tls_is_skb_tx_device_offloaded will return false.
1314		 */
1315		WRITE_ONCE(ctx->sk->sk_validate_xmit_skb, tls_validate_xmit_skb_sw);
1316
1317		/* Stop the RX and TX resync.
1318		 * tls_dev_resync must not be called after tls_dev_del.
1319		 */
1320		rcu_assign_pointer(ctx->netdev, NULL);
1321
1322		/* Start skipping the RX resync logic completely. */
1323		set_bit(TLS_RX_DEV_DEGRADED, &ctx->flags);
1324
1325		/* Sync with inflight packets. After this point:
1326		 * TX: no non-encrypted packets will be passed to the driver.
1327		 * RX: resync requests from the driver will be ignored.
1328		 */
1329		synchronize_net();
1330
1331		/* Release the offload context on the driver side. */
1332		if (ctx->tx_conf == TLS_HW)
1333			netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
1334							TLS_OFFLOAD_CTX_DIR_TX);
1335		if (ctx->rx_conf == TLS_HW &&
1336		    !test_bit(TLS_RX_DEV_CLOSED, &ctx->flags))
1337			netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
1338							TLS_OFFLOAD_CTX_DIR_RX);
1339
1340		dev_put(netdev);
1341
1342		/* Move the context to a separate list for two reasons:
1343		 * 1. When the context is deallocated, list_del is called.
1344		 * 2. It's no longer an offloaded context, so we don't want to
1345		 *    run offload-specific code on this context.
1346		 */
1347		spin_lock_irqsave(&tls_device_lock, flags);
1348		list_move_tail(&ctx->list, &tls_device_down_list);
1349		spin_unlock_irqrestore(&tls_device_lock, flags);
1350
1351		/* Device contexts for RX and TX will be freed in on sk_destruct
1352		 * by tls_device_free_ctx. rx_conf and tx_conf stay in TLS_HW.
1353		 * Now release the ref taken above.
1354		 */
1355		if (refcount_dec_and_test(&ctx->refcount)) {
1356			/* sk_destruct ran after tls_device_down took a ref, and
1357			 * it returned early. Complete the destruction here.
1358			 */
1359			list_del(&ctx->list);
1360			tls_device_free_ctx(ctx);
1361		}
1362	}
1363
1364	up_write(&device_offload_lock);
1365
1366	flush_workqueue(destruct_wq);
1367
1368	return NOTIFY_DONE;
1369}
1370
1371static int tls_dev_event(struct notifier_block *this, unsigned long event,
1372			 void *ptr)
1373{
1374	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1375
1376	if (!dev->tlsdev_ops &&
1377	    !(dev->features & (NETIF_F_HW_TLS_RX | NETIF_F_HW_TLS_TX)))
1378		return NOTIFY_DONE;
1379
1380	switch (event) {
1381	case NETDEV_REGISTER:
1382	case NETDEV_FEAT_CHANGE:
1383		if (netif_is_bond_master(dev))
1384			return NOTIFY_DONE;
1385		if ((dev->features & NETIF_F_HW_TLS_RX) &&
1386		    !dev->tlsdev_ops->tls_dev_resync)
1387			return NOTIFY_BAD;
1388
1389		if  (dev->tlsdev_ops &&
1390		     dev->tlsdev_ops->tls_dev_add &&
1391		     dev->tlsdev_ops->tls_dev_del)
1392			return NOTIFY_DONE;
1393		else
1394			return NOTIFY_BAD;
1395	case NETDEV_DOWN:
1396		return tls_device_down(dev);
1397	}
1398	return NOTIFY_DONE;
1399}
1400
1401static struct notifier_block tls_dev_notifier = {
1402	.notifier_call	= tls_dev_event,
1403};
1404
1405int __init tls_device_init(void)
1406{
1407	int err;
1408
1409	dummy_page = alloc_page(GFP_KERNEL);
1410	if (!dummy_page)
1411		return -ENOMEM;
1412
1413	destruct_wq = alloc_workqueue("ktls_device_destruct", 0, 0);
1414	if (!destruct_wq) {
1415		err = -ENOMEM;
1416		goto err_free_dummy;
1417	}
1418
1419	err = register_netdevice_notifier(&tls_dev_notifier);
1420	if (err)
1421		goto err_destroy_wq;
1422
1423	return 0;
1424
1425err_destroy_wq:
1426	destroy_workqueue(destruct_wq);
1427err_free_dummy:
1428	put_page(dummy_page);
1429	return err;
1430}
1431
1432void __exit tls_device_cleanup(void)
1433{
1434	unregister_netdevice_notifier(&tls_dev_notifier);
1435	destroy_workqueue(destruct_wq);
1436	clean_acked_data_flush();
1437	put_page(dummy_page);
1438}