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