net/tls/tls_device.c

   1 /* Copyright (c) 2018, Mellanox Technologies All rights reserved.
   2  *
   3  * This software is available to you under a choice of one of two
   4  * licenses.  You may choose to be licensed under the terms of the GNU
   5  * General Public License (GPL) Version 2, available from the file
   6  * COPYING in the main directory of this source tree, or the
   7  * OpenIB.org BSD license below:
   8  *
   9  *     Redistribution and use in source and binary forms, with or
  10  *     without modification, are permitted provided that the following
  11  *     conditions are met:
  12  *
  13  *      - Redistributions of source code must retain the above
  14  *        copyright notice, this list of conditions and the following
  15  *        disclaimer.
  16  *
  17  *      - Redistributions in binary form must reproduce the above
  18  *        copyright notice, this list of conditions and the following
  19  *        disclaimer in the documentation and/or other materials
  20  *        provided with the distribution.
  21  *
  22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  26  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  27  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  28  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  29  * SOFTWARE.
  30  */
  31
  32 #include <crypto/aead.h>
  33 #include <linux/highmem.h>
  34 #include <linux/module.h>
  35 #include <linux/netdevice.h>
  36 #include <net/dst.h>
  37 #include <net/inet_connection_sock.h>
  38 #include <net/tcp.h>
  39 #include <net/tls.h>
  40
  41 /* device_offload_lock is used to synchronize tls_dev_add
  42  * against NETDEV_DOWN notifications.
  43  */
  44 static DECLARE_RWSEM(device_offload_lock);
  45
  46 static void tls_device_gc_task(struct work_struct *work);
  47
  48 static DECLARE_WORK(tls_device_gc_work, tls_device_gc_task);
  49 static LIST_HEAD(tls_device_gc_list);
  50 static LIST_HEAD(tls_device_list);
  51 static DEFINE_SPINLOCK(tls_device_lock);
  52
  53 static void tls_device_free_ctx(struct tls_context *ctx)
  54 {
  55         if (ctx->tx_conf == TLS_HW) {
  56                 kfree(tls_offload_ctx_tx(ctx));
  57                 kfree(ctx->tx.rec_seq);
  58                 kfree(ctx->tx.iv);
  59         }
  60
  61         if (ctx->rx_conf == TLS_HW)
  62                 kfree(tls_offload_ctx_rx(ctx));
  63
  64         tls_ctx_free(NULL, ctx);
  65 }
  66
  67 static void tls_device_gc_task(struct work_struct *work)
  68 {
  69         struct tls_context *ctx, *tmp;
  70         unsigned long flags;
  71         LIST_HEAD(gc_list);
  72
  73         spin_lock_irqsave(&tls_device_lock, flags);
  74         list_splice_init(&tls_device_gc_list, &gc_list);
  75         spin_unlock_irqrestore(&tls_device_lock, flags);
  76
  77         list_for_each_entry_safe(ctx, tmp, &gc_list, list) {
  78                 struct net_device *netdev = ctx->netdev;
  79
  80                 if (netdev && ctx->tx_conf == TLS_HW) {
  81                         netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
  82                                                         TLS_OFFLOAD_CTX_DIR_TX);
  83                         dev_put(netdev);
  84                         ctx->netdev = NULL;
  85                 }
  86
  87                 list_del(&ctx->list);
  88                 tls_device_free_ctx(ctx);
  89         }
  90 }
  91
  92 static void tls_device_queue_ctx_destruction(struct tls_context *ctx)
  93 {
  94         unsigned long flags;
  95
  96         spin_lock_irqsave(&tls_device_lock, flags);
  97         list_move_tail(&ctx->list, &tls_device_gc_list);
  98
  99         /* schedule_work inside the spinlock
 100          * to make sure tls_device_down waits for that work.
 101          */
 102         schedule_work(&tls_device_gc_work);
 103
 104         spin_unlock_irqrestore(&tls_device_lock, flags);
 105 }
 106
 107 /* We assume that the socket is already connected */
 108 static struct net_device *get_netdev_for_sock(struct sock *sk)
 109 {
 110         struct dst_entry *dst = sk_dst_get(sk);
 111         struct net_device *netdev = NULL;
 112
 113         if (likely(dst)) {
 114                 netdev = dst->dev;
 115                 dev_hold(netdev);
 116         }
 117
 118         dst_release(dst);
 119
 120         return netdev;
 121 }
 122
 123 static void destroy_record(struct tls_record_info *record)
 124 {
 125         int i;
 126
 127         for (i = 0; i < record->num_frags; i++)
 128                 __skb_frag_unref(&record->frags[i]);
 129         kfree(record);
 130 }
 131
 132 static void delete_all_records(struct tls_offload_context_tx *offload_ctx)
 133 {
 134         struct tls_record_info *info, *temp;
 135
 136         list_for_each_entry_safe(info, temp, &offload_ctx->records_list, list) {
 137                 list_del(&info->list);
 138                 destroy_record(info);
 139         }
 140
 141         offload_ctx->retransmit_hint = NULL;
 142 }
 143
 144 static void tls_icsk_clean_acked(struct sock *sk, u32 acked_seq)
 145 {
 146         struct tls_context *tls_ctx = tls_get_ctx(sk);
 147         struct tls_record_info *info, *temp;
 148         struct tls_offload_context_tx *ctx;
 149         u64 deleted_records = 0;
 150         unsigned long flags;
 151
 152         if (!tls_ctx)
 153                 return;
 154
 155         ctx = tls_offload_ctx_tx(tls_ctx);
 156
 157         spin_lock_irqsave(&ctx->lock, flags);
 158         info = ctx->retransmit_hint;
 159         if (info && !before(acked_seq, info->end_seq))
 160                 ctx->retransmit_hint = NULL;
 161
 162         list_for_each_entry_safe(info, temp, &ctx->records_list, list) {
 163                 if (before(acked_seq, info->end_seq))
 164                         break;
 165                 list_del(&info->list);
 166
 167                 destroy_record(info);
 168                 deleted_records++;
 169         }
 170
 171         ctx->unacked_record_sn += deleted_records;
 172         spin_unlock_irqrestore(&ctx->lock, flags);
 173 }
 174
 175 /* At this point, there should be no references on this
 176  * socket and no in-flight SKBs associated with this
 177  * socket, so it is safe to free all the resources.
 178  */
 179 static void tls_device_sk_destruct(struct sock *sk)
 180 {
 181         struct tls_context *tls_ctx = tls_get_ctx(sk);
 182         struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
 183
 184         tls_ctx->sk_destruct(sk);
 185
 186         if (tls_ctx->tx_conf == TLS_HW) {
 187                 if (ctx->open_record)
 188                         destroy_record(ctx->open_record);
 189                 delete_all_records(ctx);
 190                 crypto_free_aead(ctx->aead_send);
 191                 clean_acked_data_disable(inet_csk(sk));
 192         }
 193
 194         if (refcount_dec_and_test(&tls_ctx->refcount))
 195                 tls_device_queue_ctx_destruction(tls_ctx);
 196 }
 197
 198 void tls_device_free_resources_tx(struct sock *sk)
 199 {
 200         struct tls_context *tls_ctx = tls_get_ctx(sk);
 201
 202         tls_free_partial_record(sk, tls_ctx);
 203 }
 204
 205 static void tls_device_resync_tx(struct sock *sk, struct tls_context *tls_ctx,
 206                                  u32 seq)
 207 {
 208         struct net_device *netdev;
 209         struct sk_buff *skb;
 210         int err = 0;
 211         u8 *rcd_sn;
 212
 213         skb = tcp_write_queue_tail(sk);
 214         if (skb)
 215                 TCP_SKB_CB(skb)->eor = 1;
 216
 217         rcd_sn = tls_ctx->tx.rec_seq;
 218
 219         down_read(&device_offload_lock);
 220         netdev = tls_ctx->netdev;
 221         if (netdev)
 222                 err = netdev->tlsdev_ops->tls_dev_resync(netdev, sk, seq,
 223                                                          rcd_sn,
 224                                                          TLS_OFFLOAD_CTX_DIR_TX);
 225         up_read(&device_offload_lock);
 226         if (err)
 227                 return;
 228
 229         clear_bit_unlock(TLS_TX_SYNC_SCHED, &tls_ctx->flags);
 230 }
 231
 232 static void tls_append_frag(struct tls_record_info *record,
 233                             struct page_frag *pfrag,
 234                             int size)
 235 {
 236         skb_frag_t *frag;
 237
 238         frag = &record->frags[record->num_frags - 1];
 239         if (skb_frag_page(frag) == pfrag->page &&
 240             skb_frag_off(frag) + skb_frag_size(frag) == pfrag->offset) {
 241                 skb_frag_size_add(frag, size);
 242         } else {
 243                 ++frag;
 244                 __skb_frag_set_page(frag, pfrag->page);
 245                 skb_frag_off_set(frag, pfrag->offset);
 246                 skb_frag_size_set(frag, size);
 247                 ++record->num_frags;
 248                 get_page(pfrag->page);
 249         }
 250
 251         pfrag->offset += size;
 252         record->len += size;
 253 }
 254
 255 static int tls_push_record(struct sock *sk,
 256                            struct tls_context *ctx,
 257                            struct tls_offload_context_tx *offload_ctx,
 258                            struct tls_record_info *record,
 259                            int flags)
 260 {
 261         struct tls_prot_info *prot = &ctx->prot_info;
 262         struct tcp_sock *tp = tcp_sk(sk);
 263         skb_frag_t *frag;
 264         int i;
 265
 266         record->end_seq = tp->write_seq + record->len;
 267         list_add_tail_rcu(&record->list, &offload_ctx->records_list);
 268         offload_ctx->open_record = NULL;
 269
 270         if (test_bit(TLS_TX_SYNC_SCHED, &ctx->flags))
 271                 tls_device_resync_tx(sk, ctx, tp->write_seq);
 272
 273         tls_advance_record_sn(sk, prot, &ctx->tx);
 274
 275         for (i = 0; i < record->num_frags; i++) {
 276                 frag = &record->frags[i];
 277                 sg_unmark_end(&offload_ctx->sg_tx_data[i]);
 278                 sg_set_page(&offload_ctx->sg_tx_data[i], skb_frag_page(frag),
 279                             skb_frag_size(frag), skb_frag_off(frag));
 280                 sk_mem_charge(sk, skb_frag_size(frag));
 281                 get_page(skb_frag_page(frag));
 282         }
 283         sg_mark_end(&offload_ctx->sg_tx_data[record->num_frags - 1]);
 284
 285         /* all ready, send */
 286         return tls_push_sg(sk, ctx, offload_ctx->sg_tx_data, 0, flags);
 287 }
 288
 289 static int tls_device_record_close(struct sock *sk,
 290                                    struct tls_context *ctx,
 291                                    struct tls_record_info *record,
 292                                    struct page_frag *pfrag,
 293                                    unsigned char record_type)
 294 {
 295         struct tls_prot_info *prot = &ctx->prot_info;
 296         int ret;
 297
 298         /* append tag
 299          * device will fill in the tag, we just need to append a placeholder
 300          * use socket memory to improve coalescing (re-using a single buffer
 301          * increases frag count)
 302          * if we can't allocate memory now, steal some back from data
 303          */
 304         if (likely(skb_page_frag_refill(prot->tag_size, pfrag,
 305                                         sk->sk_allocation))) {
 306                 ret = 0;
 307                 tls_append_frag(record, pfrag, prot->tag_size);
 308         } else {
 309                 ret = prot->tag_size;
 310                 if (record->len <= prot->overhead_size)
 311                         return -ENOMEM;
 312         }
 313
 314         /* fill prepend */
 315         tls_fill_prepend(ctx, skb_frag_address(&record->frags[0]),
 316                          record->len - prot->overhead_size,
 317                          record_type, prot->version);
 318         return ret;
 319 }
 320
 321 static int tls_create_new_record(struct tls_offload_context_tx *offload_ctx,
 322                                  struct page_frag *pfrag,
 323                                  size_t prepend_size)
 324 {
 325         struct tls_record_info *record;
 326         skb_frag_t *frag;
 327
 328         record = kmalloc(sizeof(*record), GFP_KERNEL);
 329         if (!record)
 330                 return -ENOMEM;
 331
 332         frag = &record->frags[0];
 333         __skb_frag_set_page(frag, pfrag->page);
 334         skb_frag_off_set(frag, pfrag->offset);
 335         skb_frag_size_set(frag, prepend_size);
 336
 337         get_page(pfrag->page);
 338         pfrag->offset += prepend_size;
 339
 340         record->num_frags = 1;
 341         record->len = prepend_size;
 342         offload_ctx->open_record = record;
 343         return 0;
 344 }
 345
 346 static int tls_do_allocation(struct sock *sk,
 347                              struct tls_offload_context_tx *offload_ctx,
 348                              struct page_frag *pfrag,
 349                              size_t prepend_size)
 350 {
 351         int ret;
 352
 353         if (!offload_ctx->open_record) {
 354                 if (unlikely(!skb_page_frag_refill(prepend_size, pfrag,
 355                                                    sk->sk_allocation))) {
 356                         sk->sk_prot->enter_memory_pressure(sk);
 357                         sk_stream_moderate_sndbuf(sk);
 358                         return -ENOMEM;
 359                 }
 360
 361                 ret = tls_create_new_record(offload_ctx, pfrag, prepend_size);
 362                 if (ret)
 363                         return ret;
 364
 365                 if (pfrag->size > pfrag->offset)
 366                         return 0;
 367         }
 368
 369         if (!sk_page_frag_refill(sk, pfrag))
 370                 return -ENOMEM;
 371
 372         return 0;
 373 }
 374
 375 static int tls_device_copy_data(void *addr, size_t bytes, struct iov_iter *i)
 376 {
 377         size_t pre_copy, nocache;
 378
 379         pre_copy = ~((unsigned long)addr - 1) & (SMP_CACHE_BYTES - 1);
 380         if (pre_copy) {
 381                 pre_copy = min(pre_copy, bytes);
 382                 if (copy_from_iter(addr, pre_copy, i) != pre_copy)
 383                         return -EFAULT;
 384                 bytes -= pre_copy;
 385                 addr += pre_copy;
 386         }
 387
 388         nocache = round_down(bytes, SMP_CACHE_BYTES);
 389         if (copy_from_iter_nocache(addr, nocache, i) != nocache)
 390                 return -EFAULT;
 391         bytes -= nocache;
 392         addr += nocache;
 393
 394         if (bytes && copy_from_iter(addr, bytes, i) != bytes)
 395                 return -EFAULT;
 396
 397         return 0;
 398 }
 399
 400 static int tls_push_data(struct sock *sk,
 401                          struct iov_iter *msg_iter,
 402                          size_t size, int flags,
 403                          unsigned char record_type)
 404 {
 405         struct tls_context *tls_ctx = tls_get_ctx(sk);
 406         struct tls_prot_info *prot = &tls_ctx->prot_info;
 407         struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
 408         int more = flags & (MSG_SENDPAGE_NOTLAST | MSG_MORE);
 409         struct tls_record_info *record = ctx->open_record;
 410         int tls_push_record_flags;
 411         struct page_frag *pfrag;
 412         size_t orig_size = size;
 413         u32 max_open_record_len;
 414         int copy, rc = 0;
 415         bool done = false;
 416         long timeo;
 417
 418         if (flags &
 419             ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL | MSG_SENDPAGE_NOTLAST))
 420                 return -ENOTSUPP;
 421
 422         if (sk->sk_err)
 423                 return -sk->sk_err;
 424
 425         flags |= MSG_SENDPAGE_DECRYPTED;
 426         tls_push_record_flags = flags | MSG_SENDPAGE_NOTLAST;
 427
 428         timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
 429         if (tls_is_partially_sent_record(tls_ctx)) {
 430                 rc = tls_push_partial_record(sk, tls_ctx, flags);
 431                 if (rc < 0)
 432                         return rc;
 433         }
 434
 435         pfrag = sk_page_frag(sk);
 436
 437         /* TLS_HEADER_SIZE is not counted as part of the TLS record, and
 438          * we need to leave room for an authentication tag.
 439          */
 440         max_open_record_len = TLS_MAX_PAYLOAD_SIZE +
 441                               prot->prepend_size;
 442         do {
 443                 rc = tls_do_allocation(sk, ctx, pfrag,
 444                                        prot->prepend_size);
 445                 if (rc) {
 446                         rc = sk_stream_wait_memory(sk, &timeo);
 447                         if (!rc)
 448                                 continue;
 449
 450                         record = ctx->open_record;
 451                         if (!record)
 452                                 break;
 453 handle_error:
 454                         if (record_type != TLS_RECORD_TYPE_DATA) {
 455                                 /* avoid sending partial
 456                                  * record with type !=
 457                                  * application_data
 458                                  */
 459                                 size = orig_size;
 460                                 destroy_record(record);
 461                                 ctx->open_record = NULL;
 462                         } else if (record->len > prot->prepend_size) {
 463                                 goto last_record;
 464                         }
 465
 466                         break;
 467                 }
 468
 469                 record = ctx->open_record;
 470                 copy = min_t(size_t, size, (pfrag->size - pfrag->offset));
 471                 copy = min_t(size_t, copy, (max_open_record_len - record->len));
 472
 473                 rc = tls_device_copy_data(page_address(pfrag->page) +
 474                                           pfrag->offset, copy, msg_iter);
 475                 if (rc)
 476                         goto handle_error;
 477                 tls_append_frag(record, pfrag, copy);
 478
 479                 size -= copy;
 480                 if (!size) {
 481 last_record:
 482                         tls_push_record_flags = flags;
 483                         if (more) {
 484                                 tls_ctx->pending_open_record_frags =
 485                                                 !!record->num_frags;
 486                                 break;
 487                         }
 488
 489                         done = true;
 490                 }
 491
 492                 if (done || record->len >= max_open_record_len ||
 493                     (record->num_frags >= MAX_SKB_FRAGS - 1)) {
 494                         rc = tls_device_record_close(sk, tls_ctx, record,
 495                                                      pfrag, record_type);
 496                         if (rc) {
 497                                 if (rc > 0) {
 498                                         size += rc;
 499                                 } else {
 500                                         size = orig_size;
 501                                         destroy_record(record);
 502                                         ctx->open_record = NULL;
 503                                         break;
 504                                 }
 505                         }
 506
 507                         rc = tls_push_record(sk,
 508                                              tls_ctx,
 509                                              ctx,
 510                                              record,
 511                                              tls_push_record_flags);
 512                         if (rc < 0)
 513                                 break;
 514                 }
 515         } while (!done);
 516
 517         if (orig_size - size > 0)
 518                 rc = orig_size - size;
 519
 520         return rc;
 521 }
 522
 523 int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
 524 {
 525         unsigned char record_type = TLS_RECORD_TYPE_DATA;
 526         int rc;
 527
 528         lock_sock(sk);
 529
 530         if (unlikely(msg->msg_controllen)) {
 531                 rc = tls_proccess_cmsg(sk, msg, &record_type);
 532                 if (rc)
 533                         goto out;
 534         }
 535
 536         rc = tls_push_data(sk, &msg->msg_iter, size,
 537                            msg->msg_flags, record_type);
 538
 539 out:
 540         release_sock(sk);
 541         return rc;
 542 }
 543
 544 int tls_device_sendpage(struct sock *sk, struct page *page,
 545                         int offset, size_t size, int flags)
 546 {
 547         struct iov_iter msg_iter;
 548         char *kaddr = kmap(page);
 549         struct kvec iov;
 550         int rc;
 551
 552         if (flags & MSG_SENDPAGE_NOTLAST)
 553                 flags |= MSG_MORE;
 554
 555         lock_sock(sk);
 556
 557         if (flags & MSG_OOB) {
 558                 rc = -ENOTSUPP;
 559                 goto out;
 560         }
 561
 562         iov.iov_base = kaddr + offset;
 563         iov.iov_len = size;
 564         iov_iter_kvec(&msg_iter, WRITE, &iov, 1, size);
 565         rc = tls_push_data(sk, &msg_iter, size,
 566                            flags, TLS_RECORD_TYPE_DATA);
 567         kunmap(page);
 568
 569 out:
 570         release_sock(sk);
 571         return rc;
 572 }
 573
 574 struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context,
 575                                        u32 seq, u64 *p_record_sn)
 576 {
 577         u64 record_sn = context->hint_record_sn;
 578         struct tls_record_info *info;
 579
 580         info = context->retransmit_hint;
 581         if (!info ||
 582             before(seq, info->end_seq - info->len)) {
 583                 /* if retransmit_hint is irrelevant start
 584                  * from the beggining of the list
 585                  */
 586                 info = list_first_entry_or_null(&context->records_list,
 587                                                 struct tls_record_info, list);
 588                 if (!info)
 589                         return NULL;
 590                 record_sn = context->unacked_record_sn;
 591         }
 592
 593         /* We just need the _rcu for the READ_ONCE() */
 594         rcu_read_lock();
 595         list_for_each_entry_from_rcu(info, &context->records_list, list) {
 596                 if (before(seq, info->end_seq)) {
 597                         if (!context->retransmit_hint ||
 598                             after(info->end_seq,
 599                                   context->retransmit_hint->end_seq)) {
 600                                 context->hint_record_sn = record_sn;
 601                                 context->retransmit_hint = info;
 602                         }
 603                         *p_record_sn = record_sn;
 604                         goto exit_rcu_unlock;
 605                 }
 606                 record_sn++;
 607         }
 608         info = NULL;
 609
 610 exit_rcu_unlock:
 611         rcu_read_unlock();
 612         return info;
 613 }
 614 EXPORT_SYMBOL(tls_get_record);
 615
 616 static int tls_device_push_pending_record(struct sock *sk, int flags)
 617 {
 618         struct iov_iter msg_iter;
 619
 620         iov_iter_kvec(&msg_iter, WRITE, NULL, 0, 0);
 621         return tls_push_data(sk, &msg_iter, 0, flags, TLS_RECORD_TYPE_DATA);
 622 }
 623
 624 void tls_device_write_space(struct sock *sk, struct tls_context *ctx)
 625 {
 626         if (!sk->sk_write_pending && tls_is_partially_sent_record(ctx)) {
 627                 gfp_t sk_allocation = sk->sk_allocation;
 628
 629                 sk->sk_allocation = GFP_ATOMIC;
 630                 tls_push_partial_record(sk, ctx,
 631                                         MSG_DONTWAIT | MSG_NOSIGNAL |
 632                                         MSG_SENDPAGE_DECRYPTED);
 633                 sk->sk_allocation = sk_allocation;
 634         }
 635 }
 636
 637 static void tls_device_resync_rx(struct tls_context *tls_ctx,
 638                                  struct sock *sk, u32 seq, u8 *rcd_sn)
 639 {
 640         struct net_device *netdev;
 641
 642         if (WARN_ON(test_and_set_bit(TLS_RX_SYNC_RUNNING, &tls_ctx->flags)))
 643                 return;
 644         netdev = READ_ONCE(tls_ctx->netdev);
 645         if (netdev)
 646                 netdev->tlsdev_ops->tls_dev_resync(netdev, sk, seq, rcd_sn,
 647                                                    TLS_OFFLOAD_CTX_DIR_RX);
 648         clear_bit_unlock(TLS_RX_SYNC_RUNNING, &tls_ctx->flags);
 649 }
 650
 651 void tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq)
 652 {
 653         struct tls_context *tls_ctx = tls_get_ctx(sk);
 654         struct tls_offload_context_rx *rx_ctx;
 655         u8 rcd_sn[TLS_MAX_REC_SEQ_SIZE];
 656         struct tls_prot_info *prot;
 657         u32 is_req_pending;
 658         s64 resync_req;
 659         u32 req_seq;
 660
 661         if (tls_ctx->rx_conf != TLS_HW)
 662                 return;
 663
 664         prot = &tls_ctx->prot_info;
 665         rx_ctx = tls_offload_ctx_rx(tls_ctx);
 666         memcpy(rcd_sn, tls_ctx->rx.rec_seq, prot->rec_seq_size);
 667
 668         switch (rx_ctx->resync_type) {
 669         case TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ:
 670                 resync_req = atomic64_read(&rx_ctx->resync_req);
 671                 req_seq = resync_req >> 32;
 672                 seq += TLS_HEADER_SIZE - 1;
 673                 is_req_pending = resync_req;
 674
 675                 if (likely(!is_req_pending) || req_seq != seq ||
 676                     !atomic64_try_cmpxchg(&rx_ctx->resync_req, &resync_req, 0))
 677                         return;
 678                 break;
 679         case TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT:
 680                 if (likely(!rx_ctx->resync_nh_do_now))
 681                         return;
 682
 683                 /* head of next rec is already in, note that the sock_inq will
 684                  * include the currently parsed message when called from parser
 685                  */
 686                 if (tcp_inq(sk) > rcd_len)
 687                         return;
 688
 689                 rx_ctx->resync_nh_do_now = 0;
 690                 seq += rcd_len;
 691                 tls_bigint_increment(rcd_sn, prot->rec_seq_size);
 692                 break;
 693         }
 694
 695         tls_device_resync_rx(tls_ctx, sk, seq, rcd_sn);
 696 }
 697
 698 static void tls_device_core_ctrl_rx_resync(struct tls_context *tls_ctx,
 699                                            struct tls_offload_context_rx *ctx,
 700                                            struct sock *sk, struct sk_buff *skb)
 701 {
 702         struct strp_msg *rxm;
 703
 704         /* device will request resyncs by itself based on stream scan */
 705         if (ctx->resync_type != TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT)
 706                 return;
 707         /* already scheduled */
 708         if (ctx->resync_nh_do_now)
 709                 return;
 710         /* seen decrypted fragments since last fully-failed record */
 711         if (ctx->resync_nh_reset) {
 712                 ctx->resync_nh_reset = 0;
 713                 ctx->resync_nh.decrypted_failed = 1;
 714                 ctx->resync_nh.decrypted_tgt = TLS_DEVICE_RESYNC_NH_START_IVAL;
 715                 return;
 716         }
 717
 718         if (++ctx->resync_nh.decrypted_failed <= ctx->resync_nh.decrypted_tgt)
 719                 return;
 720
 721         /* doing resync, bump the next target in case it fails */
 722         if (ctx->resync_nh.decrypted_tgt < TLS_DEVICE_RESYNC_NH_MAX_IVAL)
 723                 ctx->resync_nh.decrypted_tgt *= 2;
 724         else
 725                 ctx->resync_nh.decrypted_tgt += TLS_DEVICE_RESYNC_NH_MAX_IVAL;
 726
 727         rxm = strp_msg(skb);
 728
 729         /* head of next rec is already in, parser will sync for us */
 730         if (tcp_inq(sk) > rxm->full_len) {
 731                 ctx->resync_nh_do_now = 1;
 732         } else {
 733                 struct tls_prot_info *prot = &tls_ctx->prot_info;
 734                 u8 rcd_sn[TLS_MAX_REC_SEQ_SIZE];
 735
 736                 memcpy(rcd_sn, tls_ctx->rx.rec_seq, prot->rec_seq_size);
 737                 tls_bigint_increment(rcd_sn, prot->rec_seq_size);
 738
 739                 tls_device_resync_rx(tls_ctx, sk, tcp_sk(sk)->copied_seq,
 740                                      rcd_sn);
 741         }
 742 }
 743
 744 static int tls_device_reencrypt(struct sock *sk, struct sk_buff *skb)
 745 {
 746         struct strp_msg *rxm = strp_msg(skb);
 747         int err = 0, offset = rxm->offset, copy, nsg, data_len, pos;
 748         struct sk_buff *skb_iter, *unused;
 749         struct scatterlist sg[1];
 750         char *orig_buf, *buf;
 751
 752         orig_buf = kmalloc(rxm->full_len + TLS_HEADER_SIZE +
 753                            TLS_CIPHER_AES_GCM_128_IV_SIZE, sk->sk_allocation);
 754         if (!orig_buf)
 755                 return -ENOMEM;
 756         buf = orig_buf;
 757
 758         nsg = skb_cow_data(skb, 0, &unused);
 759         if (unlikely(nsg < 0)) {
 760                 err = nsg;
 761                 goto free_buf;
 762         }
 763
 764         sg_init_table(sg, 1);
 765         sg_set_buf(&sg[0], buf,
 766                    rxm->full_len + TLS_HEADER_SIZE +
 767                    TLS_CIPHER_AES_GCM_128_IV_SIZE);
 768         err = skb_copy_bits(skb, offset, buf,
 769                             TLS_HEADER_SIZE + TLS_CIPHER_AES_GCM_128_IV_SIZE);
 770         if (err)
 771                 goto free_buf;
 772
 773         /* We are interested only in the decrypted data not the auth */
 774         err = decrypt_skb(sk, skb, sg);
 775         if (err != -EBADMSG)
 776                 goto free_buf;
 777         else
 778                 err = 0;
 779
 780         data_len = rxm->full_len - TLS_CIPHER_AES_GCM_128_TAG_SIZE;
 781
 782         if (skb_pagelen(skb) > offset) {
 783                 copy = min_t(int, skb_pagelen(skb) - offset, data_len);
 784
 785                 if (skb->decrypted) {
 786                         err = skb_store_bits(skb, offset, buf, copy);
 787                         if (err)
 788                                 goto free_buf;
 789                 }
 790
 791                 offset += copy;
 792                 buf += copy;
 793         }
 794
 795         pos = skb_pagelen(skb);
 796         skb_walk_frags(skb, skb_iter) {
 797                 int frag_pos;
 798
 799                 /* Practically all frags must belong to msg if reencrypt
 800                  * is needed with current strparser and coalescing logic,
 801                  * but strparser may "get optimized", so let's be safe.
 802                  */
 803                 if (pos + skb_iter->len <= offset)
 804                         goto done_with_frag;
 805                 if (pos >= data_len + rxm->offset)
 806                         break;
 807
 808                 frag_pos = offset - pos;
 809                 copy = min_t(int, skb_iter->len - frag_pos,
 810                              data_len + rxm->offset - offset);
 811
 812                 if (skb_iter->decrypted) {
 813                         err = skb_store_bits(skb_iter, frag_pos, buf, copy);
 814                         if (err)
 815                                 goto free_buf;
 816                 }
 817
 818                 offset += copy;
 819                 buf += copy;
 820 done_with_frag:
 821                 pos += skb_iter->len;
 822         }
 823
 824 free_buf:
 825         kfree(orig_buf);
 826         return err;
 827 }
 828
 829 int tls_device_decrypted(struct sock *sk, struct sk_buff *skb)
 830 {
 831         struct tls_context *tls_ctx = tls_get_ctx(sk);
 832         struct tls_offload_context_rx *ctx = tls_offload_ctx_rx(tls_ctx);
 833         int is_decrypted = skb->decrypted;
 834         int is_encrypted = !is_decrypted;
 835         struct sk_buff *skb_iter;
 836
 837         /* Check if all the data is decrypted already */
 838         skb_walk_frags(skb, skb_iter) {
 839                 is_decrypted &= skb_iter->decrypted;
 840                 is_encrypted &= !skb_iter->decrypted;
 841         }
 842
 843         ctx->sw.decrypted |= is_decrypted;
 844
 845         /* Return immediately if the record is either entirely plaintext or
 846          * entirely ciphertext. Otherwise handle reencrypt partially decrypted
 847          * record.
 848          */
 849         if (is_decrypted) {
 850                 ctx->resync_nh_reset = 1;
 851                 return 0;
 852         }
 853         if (is_encrypted) {
 854                 tls_device_core_ctrl_rx_resync(tls_ctx, ctx, sk, skb);
 855                 return 0;
 856         }
 857
 858         ctx->resync_nh_reset = 1;
 859         return tls_device_reencrypt(sk, skb);
 860 }
 861
 862 static void tls_device_attach(struct tls_context *ctx, struct sock *sk,
 863                               struct net_device *netdev)
 864 {
 865         if (sk->sk_destruct != tls_device_sk_destruct) {
 866                 refcount_set(&ctx->refcount, 1);
 867                 dev_hold(netdev);
 868                 ctx->netdev = netdev;
 869                 spin_lock_irq(&tls_device_lock);
 870                 list_add_tail(&ctx->list, &tls_device_list);
 871                 spin_unlock_irq(&tls_device_lock);
 872
 873                 ctx->sk_destruct = sk->sk_destruct;
 874                 sk->sk_destruct = tls_device_sk_destruct;
 875         }
 876 }
 877
 878 int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
 879 {
 880         u16 nonce_size, tag_size, iv_size, rec_seq_size;
 881         struct tls_context *tls_ctx = tls_get_ctx(sk);
 882         struct tls_prot_info *prot = &tls_ctx->prot_info;
 883         struct tls_record_info *start_marker_record;
 884         struct tls_offload_context_tx *offload_ctx;
 885         struct tls_crypto_info *crypto_info;
 886         struct net_device *netdev;
 887         char *iv, *rec_seq;
 888         struct sk_buff *skb;
 889         __be64 rcd_sn;
 890         int rc;
 891
 892         if (!ctx)
 893                 return -EINVAL;
 894
 895         if (ctx->priv_ctx_tx)
 896                 return -EEXIST;
 897
 898         start_marker_record = kmalloc(sizeof(*start_marker_record), GFP_KERNEL);
 899         if (!start_marker_record)
 900                 return -ENOMEM;
 901
 902         offload_ctx = kzalloc(TLS_OFFLOAD_CONTEXT_SIZE_TX, GFP_KERNEL);
 903         if (!offload_ctx) {
 904                 rc = -ENOMEM;
 905                 goto free_marker_record;
 906         }
 907
 908         crypto_info = &ctx->crypto_send.info;
 909         if (crypto_info->version != TLS_1_2_VERSION) {
 910                 rc = -EOPNOTSUPP;
 911                 goto free_offload_ctx;
 912         }
 913
 914         switch (crypto_info->cipher_type) {
 915         case TLS_CIPHER_AES_GCM_128:
 916                 nonce_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
 917                 tag_size = TLS_CIPHER_AES_GCM_128_TAG_SIZE;
 918                 iv_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
 919                 iv = ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->iv;
 920                 rec_seq_size = TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE;
 921                 rec_seq =
 922                  ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->rec_seq;
 923                 break;
 924         default:
 925                 rc = -EINVAL;
 926                 goto free_offload_ctx;
 927         }
 928
 929         /* Sanity-check the rec_seq_size for stack allocations */
 930         if (rec_seq_size > TLS_MAX_REC_SEQ_SIZE) {
 931                 rc = -EINVAL;
 932                 goto free_offload_ctx;
 933         }
 934
 935         prot->version = crypto_info->version;
 936         prot->cipher_type = crypto_info->cipher_type;
 937         prot->prepend_size = TLS_HEADER_SIZE + nonce_size;
 938         prot->tag_size = tag_size;
 939         prot->overhead_size = prot->prepend_size + prot->tag_size;
 940         prot->iv_size = iv_size;
 941         ctx->tx.iv = kmalloc(iv_size + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
 942                              GFP_KERNEL);
 943         if (!ctx->tx.iv) {
 944                 rc = -ENOMEM;
 945                 goto free_offload_ctx;
 946         }
 947
 948         memcpy(ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv, iv_size);
 949
 950         prot->rec_seq_size = rec_seq_size;
 951         ctx->tx.rec_seq = kmemdup(rec_seq, rec_seq_size, GFP_KERNEL);
 952         if (!ctx->tx.rec_seq) {
 953                 rc = -ENOMEM;
 954                 goto free_iv;
 955         }
 956
 957         rc = tls_sw_fallback_init(sk, offload_ctx, crypto_info);
 958         if (rc)
 959                 goto free_rec_seq;
 960
 961         /* start at rec_seq - 1 to account for the start marker record */
 962         memcpy(&rcd_sn, ctx->tx.rec_seq, sizeof(rcd_sn));
 963         offload_ctx->unacked_record_sn = be64_to_cpu(rcd_sn) - 1;
 964
 965         start_marker_record->end_seq = tcp_sk(sk)->write_seq;
 966         start_marker_record->len = 0;
 967         start_marker_record->num_frags = 0;
 968
 969         INIT_LIST_HEAD(&offload_ctx->records_list);
 970         list_add_tail(&start_marker_record->list, &offload_ctx->records_list);
 971         spin_lock_init(&offload_ctx->lock);
 972         sg_init_table(offload_ctx->sg_tx_data,
 973                       ARRAY_SIZE(offload_ctx->sg_tx_data));
 974
 975         clean_acked_data_enable(inet_csk(sk), &tls_icsk_clean_acked);
 976         ctx->push_pending_record = tls_device_push_pending_record;
 977
 978         /* TLS offload is greatly simplified if we don't send
 979          * SKBs where only part of the payload needs to be encrypted.
 980          * So mark the last skb in the write queue as end of record.
 981          */
 982         skb = tcp_write_queue_tail(sk);
 983         if (skb)
 984                 TCP_SKB_CB(skb)->eor = 1;
 985
 986         netdev = get_netdev_for_sock(sk);
 987         if (!netdev) {
 988                 pr_err_ratelimited("%s: netdev not found\n", __func__);
 989                 rc = -EINVAL;
 990                 goto disable_cad;
 991         }
 992
 993         if (!(netdev->features & NETIF_F_HW_TLS_TX)) {
 994                 rc = -ENOTSUPP;
 995                 goto release_netdev;
 996         }
 997
 998         /* Avoid offloading if the device is down
 999          * We don't want to offload new flows after
1000          * the NETDEV_DOWN event
1001          *
1002          * device_offload_lock is taken in tls_devices's NETDEV_DOWN
1003          * handler thus protecting from the device going down before
1004          * ctx was added to tls_device_list.
1005          */
1006         down_read(&device_offload_lock);
1007         if (!(netdev->flags & IFF_UP)) {
1008                 rc = -EINVAL;
1009                 goto release_lock;
1010         }
1011
1012         ctx->priv_ctx_tx = offload_ctx;
1013         rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_TX,
1014                                              &ctx->crypto_send.info,
1015                                              tcp_sk(sk)->write_seq);
1016         if (rc)
1017                 goto release_lock;
1018
1019         tls_device_attach(ctx, sk, netdev);
1020         up_read(&device_offload_lock);
1021
1022         /* following this assignment tls_is_sk_tx_device_offloaded
1023          * will return true and the context might be accessed
1024          * by the netdev's xmit function.
1025          */
1026         smp_store_release(&sk->sk_validate_xmit_skb, tls_validate_xmit_skb);
1027         dev_put(netdev);
1028
1029         return 0;
1030
1031 release_lock:
1032         up_read(&device_offload_lock);
1033 release_netdev:
1034         dev_put(netdev);
1035 disable_cad:
1036         clean_acked_data_disable(inet_csk(sk));
1037         crypto_free_aead(offload_ctx->aead_send);
1038 free_rec_seq:
1039         kfree(ctx->tx.rec_seq);
1040 free_iv:
1041         kfree(ctx->tx.iv);
1042 free_offload_ctx:
1043         kfree(offload_ctx);
1044         ctx->priv_ctx_tx = NULL;
1045 free_marker_record:
1046         kfree(start_marker_record);
1047         return rc;
1048 }
1049
1050 int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
1051 {
1052         struct tls_offload_context_rx *context;
1053         struct net_device *netdev;
1054         int rc = 0;
1055
1056         if (ctx->crypto_recv.info.version != TLS_1_2_VERSION)
1057                 return -EOPNOTSUPP;
1058
1059         netdev = get_netdev_for_sock(sk);
1060         if (!netdev) {
1061                 pr_err_ratelimited("%s: netdev not found\n", __func__);
1062                 return -EINVAL;
1063         }
1064
1065         if (!(netdev->features & NETIF_F_HW_TLS_RX)) {
1066                 rc = -ENOTSUPP;
1067                 goto release_netdev;
1068         }
1069
1070         /* Avoid offloading if the device is down
1071          * We don't want to offload new flows after
1072          * the NETDEV_DOWN event
1073          *
1074          * device_offload_lock is taken in tls_devices's NETDEV_DOWN
1075          * handler thus protecting from the device going down before
1076          * ctx was added to tls_device_list.
1077          */
1078         down_read(&device_offload_lock);
1079         if (!(netdev->flags & IFF_UP)) {
1080                 rc = -EINVAL;
1081                 goto release_lock;
1082         }
1083
1084         context = kzalloc(TLS_OFFLOAD_CONTEXT_SIZE_RX, GFP_KERNEL);
1085         if (!context) {
1086                 rc = -ENOMEM;
1087                 goto release_lock;
1088         }
1089         context->resync_nh_reset = 1;
1090
1091         ctx->priv_ctx_rx = context;
1092         rc = tls_set_sw_offload(sk, ctx, 0);
1093         if (rc)
1094                 goto release_ctx;
1095
1096         rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_RX,
1097                                              &ctx->crypto_recv.info,
1098                                              tcp_sk(sk)->copied_seq);
1099         if (rc)
1100                 goto free_sw_resources;
1101
1102         tls_device_attach(ctx, sk, netdev);
1103         up_read(&device_offload_lock);
1104
1105         dev_put(netdev);
1106
1107         return 0;
1108
1109 free_sw_resources:
1110         up_read(&device_offload_lock);
1111         tls_sw_free_resources_rx(sk);
1112         down_read(&device_offload_lock);
1113 release_ctx:
1114         ctx->priv_ctx_rx = NULL;
1115 release_lock:
1116         up_read(&device_offload_lock);
1117 release_netdev:
1118         dev_put(netdev);
1119         return rc;
1120 }
1121
1122 void tls_device_offload_cleanup_rx(struct sock *sk)
1123 {
1124         struct tls_context *tls_ctx = tls_get_ctx(sk);
1125         struct net_device *netdev;
1126
1127         down_read(&device_offload_lock);
1128         netdev = tls_ctx->netdev;
1129         if (!netdev)
1130                 goto out;
1131
1132         netdev->tlsdev_ops->tls_dev_del(netdev, tls_ctx,
1133                                         TLS_OFFLOAD_CTX_DIR_RX);
1134
1135         if (tls_ctx->tx_conf != TLS_HW) {
1136                 dev_put(netdev);
1137                 tls_ctx->netdev = NULL;
1138         }
1139 out:
1140         up_read(&device_offload_lock);
1141         tls_sw_release_resources_rx(sk);
1142 }
1143
1144 static int tls_device_down(struct net_device *netdev)
1145 {
1146         struct tls_context *ctx, *tmp;
1147         unsigned long flags;
1148         LIST_HEAD(list);
1149
1150         /* Request a write lock to block new offload attempts */
1151         down_write(&device_offload_lock);
1152
1153         spin_lock_irqsave(&tls_device_lock, flags);
1154         list_for_each_entry_safe(ctx, tmp, &tls_device_list, list) {
1155                 if (ctx->netdev != netdev ||
1156                     !refcount_inc_not_zero(&ctx->refcount))
1157                         continue;
1158
1159                 list_move(&ctx->list, &list);
1160         }
1161         spin_unlock_irqrestore(&tls_device_lock, flags);
1162
1163         list_for_each_entry_safe(ctx, tmp, &list, list) {
1164                 if (ctx->tx_conf == TLS_HW)
1165                         netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
1166                                                         TLS_OFFLOAD_CTX_DIR_TX);
1167                 if (ctx->rx_conf == TLS_HW)
1168                         netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
1169                                                         TLS_OFFLOAD_CTX_DIR_RX);
1170                 WRITE_ONCE(ctx->netdev, NULL);
1171                 smp_mb__before_atomic(); /* pairs with test_and_set_bit() */
1172                 while (test_bit(TLS_RX_SYNC_RUNNING, &ctx->flags))
1173                         usleep_range(10, 200);
1174                 dev_put(netdev);
1175                 list_del_init(&ctx->list);
1176
1177                 if (refcount_dec_and_test(&ctx->refcount))
1178                         tls_device_free_ctx(ctx);
1179         }
1180
1181         up_write(&device_offload_lock);
1182
1183         flush_work(&tls_device_gc_work);
1184
1185         return NOTIFY_DONE;
1186 }
1187
1188 static int tls_dev_event(struct notifier_block *this, unsigned long event,
1189                          void *ptr)
1190 {
1191         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1192
1193         if (!dev->tlsdev_ops &&
1194             !(dev->features & (NETIF_F_HW_TLS_RX | NETIF_F_HW_TLS_TX)))
1195                 return NOTIFY_DONE;
1196
1197         switch (event) {
1198         case NETDEV_REGISTER:
1199         case NETDEV_FEAT_CHANGE:
1200                 if ((dev->features & NETIF_F_HW_TLS_RX) &&
1201                     !dev->tlsdev_ops->tls_dev_resync)
1202                         return NOTIFY_BAD;
1203
1204                 if  (dev->tlsdev_ops &&
1205                      dev->tlsdev_ops->tls_dev_add &&
1206                      dev->tlsdev_ops->tls_dev_del)
1207                         return NOTIFY_DONE;
1208                 else
1209                         return NOTIFY_BAD;
1210         case NETDEV_DOWN:
1211                 return tls_device_down(dev);
1212         }
1213         return NOTIFY_DONE;
1214 }
1215
1216 static struct notifier_block tls_dev_notifier = {
1217         .notifier_call  = tls_dev_event,
1218 };
1219
1220 void __init tls_device_init(void)
1221 {
1222         register_netdevice_notifier(&tls_dev_notifier);
1223 }
1224
1225 void __exit tls_device_cleanup(void)
1226 {
1227         unregister_netdevice_notifier(&tls_dev_notifier);
1228         flush_work(&tls_device_gc_work);
1229         clean_acked_data_flush();
1230 }