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