linux/net/tls/tls_device.c
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   1/* Copyright (c) 2018, Mellanox Technologies All rights reserved.
   2 *
   3 * This software is available to you under a choice of one of two
   4 * licenses.  You may choose to be licensed under the terms of the GNU
   5 * General Public License (GPL) Version 2, available from the file
   6 * COPYING in the main directory of this source tree, or the
   7 * OpenIB.org BSD license below:
   8 *
   9 *     Redistribution and use in source and binary forms, with or
  10 *     without modification, are permitted provided that the following
  11 *     conditions are met:
  12 *
  13 *      - Redistributions of source code must retain the above
  14 *        copyright notice, this list of conditions and the following
  15 *        disclaimer.
  16 *
  17 *      - Redistributions in binary form must reproduce the above
  18 *        copyright notice, this list of conditions and the following
  19 *        disclaimer in the documentation and/or other materials
  20 *        provided with the distribution.
  21 *
  22 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  26 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  27 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  28 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  29 * SOFTWARE.
  30 */
  31
  32#include <crypto/aead.h>
  33#include <linux/highmem.h>
  34#include <linux/module.h>
  35#include <linux/netdevice.h>
  36#include <net/dst.h>
  37#include <net/inet_connection_sock.h>
  38#include <net/tcp.h>
  39#include <net/tls.h>
  40
  41#include "trace.h"
  42
  43/* device_offload_lock is used to synchronize tls_dev_add
  44 * against NETDEV_DOWN notifications.
  45 */
  46static DECLARE_RWSEM(device_offload_lock);
  47
  48static void tls_device_gc_task(struct work_struct *work);
  49
  50static DECLARE_WORK(tls_device_gc_work, tls_device_gc_task);
  51static LIST_HEAD(tls_device_gc_list);
  52static LIST_HEAD(tls_device_list);
  53static LIST_HEAD(tls_device_down_list);
  54static DEFINE_SPINLOCK(tls_device_lock);
  55
  56static void tls_device_free_ctx(struct tls_context *ctx)
  57{
  58        if (ctx->tx_conf == TLS_HW) {
  59                kfree(tls_offload_ctx_tx(ctx));
  60                kfree(ctx->tx.rec_seq);
  61                kfree(ctx->tx.iv);
  62        }
  63
  64        if (ctx->rx_conf == TLS_HW)
  65                kfree(tls_offload_ctx_rx(ctx));
  66
  67        tls_ctx_free(NULL, ctx);
  68}
  69
  70static void tls_device_gc_task(struct work_struct *work)
  71{
  72        struct tls_context *ctx, *tmp;
  73        unsigned long flags;
  74        LIST_HEAD(gc_list);
  75
  76        spin_lock_irqsave(&tls_device_lock, flags);
  77        list_splice_init(&tls_device_gc_list, &gc_list);
  78        spin_unlock_irqrestore(&tls_device_lock, flags);
  79
  80        list_for_each_entry_safe(ctx, tmp, &gc_list, list) {
  81                struct net_device *netdev = ctx->netdev;
  82
  83                if (netdev && ctx->tx_conf == TLS_HW) {
  84                        netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
  85                                                        TLS_OFFLOAD_CTX_DIR_TX);
  86                        dev_put(netdev);
  87                        ctx->netdev = NULL;
  88                }
  89
  90                list_del(&ctx->list);
  91                tls_device_free_ctx(ctx);
  92        }
  93}
  94
  95static void tls_device_queue_ctx_destruction(struct tls_context *ctx)
  96{
  97        unsigned long flags;
  98
  99        spin_lock_irqsave(&tls_device_lock, flags);
 100        list_move_tail(&ctx->list, &tls_device_gc_list);
 101
 102        /* schedule_work inside the spinlock
 103         * to make sure tls_device_down waits for that work.
 104         */
 105        schedule_work(&tls_device_gc_work);
 106
 107        spin_unlock_irqrestore(&tls_device_lock, flags);
 108}
 109
 110/* We assume that the socket is already connected */
 111static struct net_device *get_netdev_for_sock(struct sock *sk)
 112{
 113        struct dst_entry *dst = sk_dst_get(sk);
 114        struct net_device *netdev = NULL;
 115
 116        if (likely(dst)) {
 117                netdev = netdev_sk_get_lowest_dev(dst->dev, sk);
 118                dev_hold(netdev);
 119        }
 120
 121        dst_release(dst);
 122
 123        return netdev;
 124}
 125
 126static void destroy_record(struct tls_record_info *record)
 127{
 128        int i;
 129
 130        for (i = 0; i < record->num_frags; i++)
 131                __skb_frag_unref(&record->frags[i], false);
 132        kfree(record);
 133}
 134
 135static 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
 147static 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
 165        list_for_each_entry_safe(info, temp, &ctx->records_list, list) {
 166                if (before(acked_seq, info->end_seq))
 167                        break;
 168                list_del(&info->list);
 169
 170                destroy_record(info);
 171                deleted_records++;
 172        }
 173
 174        ctx->unacked_record_sn += deleted_records;
 175        spin_unlock_irqrestore(&ctx->lock, flags);
 176}
 177
 178/* At this point, there should be no references on this
 179 * socket and no in-flight SKBs associated with this
 180 * socket, so it is safe to free all the resources.
 181 */
 182void tls_device_sk_destruct(struct sock *sk)
 183{
 184        struct tls_context *tls_ctx = tls_get_ctx(sk);
 185        struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
 186
 187        tls_ctx->sk_destruct(sk);
 188
 189        if (tls_ctx->tx_conf == TLS_HW) {
 190                if (ctx->open_record)
 191                        destroy_record(ctx->open_record);
 192                delete_all_records(ctx);
 193                crypto_free_aead(ctx->aead_send);
 194                clean_acked_data_disable(inet_csk(sk));
 195        }
 196
 197        if (refcount_dec_and_test(&tls_ctx->refcount))
 198                tls_device_queue_ctx_destruction(tls_ctx);
 199}
 200EXPORT_SYMBOL_GPL(tls_device_sk_destruct);
 201
 202void tls_device_free_resources_tx(struct sock *sk)
 203{
 204        struct tls_context *tls_ctx = tls_get_ctx(sk);
 205
 206        tls_free_partial_record(sk, tls_ctx);
 207}
 208
 209void tls_offload_tx_resync_request(struct sock *sk, u32 got_seq, u32 exp_seq)
 210{
 211        struct tls_context *tls_ctx = tls_get_ctx(sk);
 212
 213        trace_tls_device_tx_resync_req(sk, got_seq, exp_seq);
 214        WARN_ON(test_and_set_bit(TLS_TX_SYNC_SCHED, &tls_ctx->flags));
 215}
 216EXPORT_SYMBOL_GPL(tls_offload_tx_resync_request);
 217
 218static void tls_device_resync_tx(struct sock *sk, struct tls_context *tls_ctx,
 219                                 u32 seq)
 220{
 221        struct net_device *netdev;
 222        struct sk_buff *skb;
 223        int err = 0;
 224        u8 *rcd_sn;
 225
 226        skb = tcp_write_queue_tail(sk);
 227        if (skb)
 228                TCP_SKB_CB(skb)->eor = 1;
 229
 230        rcd_sn = tls_ctx->tx.rec_seq;
 231
 232        trace_tls_device_tx_resync_send(sk, seq, rcd_sn);
 233        down_read(&device_offload_lock);
 234        netdev = tls_ctx->netdev;
 235        if (netdev)
 236                err = netdev->tlsdev_ops->tls_dev_resync(netdev, sk, seq,
 237                                                         rcd_sn,
 238                                                         TLS_OFFLOAD_CTX_DIR_TX);
 239        up_read(&device_offload_lock);
 240        if (err)
 241                return;
 242
 243        clear_bit_unlock(TLS_TX_SYNC_SCHED, &tls_ctx->flags);
 244}
 245
 246static void tls_append_frag(struct tls_record_info *record,
 247                            struct page_frag *pfrag,
 248                            int size)
 249{
 250        skb_frag_t *frag;
 251
 252        frag = &record->frags[record->num_frags - 1];
 253        if (skb_frag_page(frag) == pfrag->page &&
 254            skb_frag_off(frag) + skb_frag_size(frag) == pfrag->offset) {
 255                skb_frag_size_add(frag, size);
 256        } else {
 257                ++frag;
 258                __skb_frag_set_page(frag, pfrag->page);
 259                skb_frag_off_set(frag, pfrag->offset);
 260                skb_frag_size_set(frag, size);
 261                ++record->num_frags;
 262                get_page(pfrag->page);
 263        }
 264
 265        pfrag->offset += size;
 266        record->len += size;
 267}
 268
 269static int tls_push_record(struct sock *sk,
 270                           struct tls_context *ctx,
 271                           struct tls_offload_context_tx *offload_ctx,
 272                           struct tls_record_info *record,
 273                           int flags)
 274{
 275        struct tls_prot_info *prot = &ctx->prot_info;
 276        struct tcp_sock *tp = tcp_sk(sk);
 277        skb_frag_t *frag;
 278        int i;
 279
 280        record->end_seq = tp->write_seq + record->len;
 281        list_add_tail_rcu(&record->list, &offload_ctx->records_list);
 282        offload_ctx->open_record = NULL;
 283
 284        if (test_bit(TLS_TX_SYNC_SCHED, &ctx->flags))
 285                tls_device_resync_tx(sk, ctx, tp->write_seq);
 286
 287        tls_advance_record_sn(sk, prot, &ctx->tx);
 288
 289        for (i = 0; i < record->num_frags; i++) {
 290                frag = &record->frags[i];
 291                sg_unmark_end(&offload_ctx->sg_tx_data[i]);
 292                sg_set_page(&offload_ctx->sg_tx_data[i], skb_frag_page(frag),
 293                            skb_frag_size(frag), skb_frag_off(frag));
 294                sk_mem_charge(sk, skb_frag_size(frag));
 295                get_page(skb_frag_page(frag));
 296        }
 297        sg_mark_end(&offload_ctx->sg_tx_data[record->num_frags - 1]);
 298
 299        /* all ready, send */
 300        return tls_push_sg(sk, ctx, offload_ctx->sg_tx_data, 0, flags);
 301}
 302
 303static int tls_device_record_close(struct sock *sk,
 304                                   struct tls_context *ctx,
 305                                   struct tls_record_info *record,
 306                                   struct page_frag *pfrag,
 307                                   unsigned char record_type)
 308{
 309        struct tls_prot_info *prot = &ctx->prot_info;
 310        int ret;
 311
 312        /* append tag
 313         * device will fill in the tag, we just need to append a placeholder
 314         * use socket memory to improve coalescing (re-using a single buffer
 315         * increases frag count)
 316         * if we can't allocate memory now, steal some back from data
 317         */
 318        if (likely(skb_page_frag_refill(prot->tag_size, pfrag,
 319                                        sk->sk_allocation))) {
 320                ret = 0;
 321                tls_append_frag(record, pfrag, prot->tag_size);
 322        } else {
 323                ret = prot->tag_size;
 324                if (record->len <= prot->overhead_size)
 325                        return -ENOMEM;
 326        }
 327
 328        /* fill prepend */
 329        tls_fill_prepend(ctx, skb_frag_address(&record->frags[0]),
 330                         record->len - prot->overhead_size,
 331                         record_type);
 332        return ret;
 333}
 334
 335static int tls_create_new_record(struct tls_offload_context_tx *offload_ctx,
 336                                 struct page_frag *pfrag,
 337                                 size_t prepend_size)
 338{
 339        struct tls_record_info *record;
 340        skb_frag_t *frag;
 341
 342        record = kmalloc(sizeof(*record), GFP_KERNEL);
 343        if (!record)
 344                return -ENOMEM;
 345
 346        frag = &record->frags[0];
 347        __skb_frag_set_page(frag, pfrag->page);
 348        skb_frag_off_set(frag, pfrag->offset);
 349        skb_frag_size_set(frag, prepend_size);
 350
 351        get_page(pfrag->page);
 352        pfrag->offset += prepend_size;
 353
 354        record->num_frags = 1;
 355        record->len = prepend_size;
 356        offload_ctx->open_record = record;
 357        return 0;
 358}
 359
 360static int tls_do_allocation(struct sock *sk,
 361                             struct tls_offload_context_tx *offload_ctx,
 362                             struct page_frag *pfrag,
 363                             size_t prepend_size)
 364{
 365        int ret;
 366
 367        if (!offload_ctx->open_record) {
 368                if (unlikely(!skb_page_frag_refill(prepend_size, pfrag,
 369                                                   sk->sk_allocation))) {
 370                        READ_ONCE(sk->sk_prot)->enter_memory_pressure(sk);
 371                        sk_stream_moderate_sndbuf(sk);
 372                        return -ENOMEM;
 373                }
 374
 375                ret = tls_create_new_record(offload_ctx, pfrag, prepend_size);
 376                if (ret)
 377                        return ret;
 378
 379                if (pfrag->size > pfrag->offset)
 380                        return 0;
 381        }
 382
 383        if (!sk_page_frag_refill(sk, pfrag))
 384                return -ENOMEM;
 385
 386        return 0;
 387}
 388
 389static int tls_device_copy_data(void *addr, size_t bytes, struct iov_iter *i)
 390{
 391        size_t pre_copy, nocache;
 392
 393        pre_copy = ~((unsigned long)addr - 1) & (SMP_CACHE_BYTES - 1);
 394        if (pre_copy) {
 395                pre_copy = min(pre_copy, bytes);
 396                if (copy_from_iter(addr, pre_copy, i) != pre_copy)
 397                        return -EFAULT;
 398                bytes -= pre_copy;
 399                addr += pre_copy;
 400        }
 401
 402        nocache = round_down(bytes, SMP_CACHE_BYTES);
 403        if (copy_from_iter_nocache(addr, nocache, i) != nocache)
 404                return -EFAULT;
 405        bytes -= nocache;
 406        addr += nocache;
 407
 408        if (bytes && copy_from_iter(addr, bytes, i) != bytes)
 409                return -EFAULT;
 410
 411        return 0;
 412}
 413
 414static int tls_push_data(struct sock *sk,
 415                         struct iov_iter *msg_iter,
 416                         size_t size, int flags,
 417                         unsigned char record_type)
 418{
 419        struct tls_context *tls_ctx = tls_get_ctx(sk);
 420        struct tls_prot_info *prot = &tls_ctx->prot_info;
 421        struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
 422        struct tls_record_info *record;
 423        int tls_push_record_flags;
 424        struct page_frag *pfrag;
 425        size_t orig_size = size;
 426        u32 max_open_record_len;
 427        bool more = false;
 428        bool done = false;
 429        int copy, rc = 0;
 430        long timeo;
 431
 432        if (flags &
 433            ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL | MSG_SENDPAGE_NOTLAST))
 434                return -EOPNOTSUPP;
 435
 436        if (unlikely(sk->sk_err))
 437                return -sk->sk_err;
 438
 439        flags |= MSG_SENDPAGE_DECRYPTED;
 440        tls_push_record_flags = flags | MSG_SENDPAGE_NOTLAST;
 441
 442        timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
 443        if (tls_is_partially_sent_record(tls_ctx)) {
 444                rc = tls_push_partial_record(sk, tls_ctx, flags);
 445                if (rc < 0)
 446                        return rc;
 447        }
 448
 449        pfrag = sk_page_frag(sk);
 450
 451        /* TLS_HEADER_SIZE is not counted as part of the TLS record, and
 452         * we need to leave room for an authentication tag.
 453         */
 454        max_open_record_len = TLS_MAX_PAYLOAD_SIZE +
 455                              prot->prepend_size;
 456        do {
 457                rc = tls_do_allocation(sk, ctx, pfrag, prot->prepend_size);
 458                if (unlikely(rc)) {
 459                        rc = sk_stream_wait_memory(sk, &timeo);
 460                        if (!rc)
 461                                continue;
 462
 463                        record = ctx->open_record;
 464                        if (!record)
 465                                break;
 466handle_error:
 467                        if (record_type != TLS_RECORD_TYPE_DATA) {
 468                                /* avoid sending partial
 469                                 * record with type !=
 470                                 * application_data
 471                                 */
 472                                size = orig_size;
 473                                destroy_record(record);
 474                                ctx->open_record = NULL;
 475                        } else if (record->len > prot->prepend_size) {
 476                                goto last_record;
 477                        }
 478
 479                        break;
 480                }
 481
 482                record = ctx->open_record;
 483                copy = min_t(size_t, size, (pfrag->size - pfrag->offset));
 484                copy = min_t(size_t, copy, (max_open_record_len - record->len));
 485
 486                rc = tls_device_copy_data(page_address(pfrag->page) +
 487                                          pfrag->offset, copy, msg_iter);
 488                if (rc)
 489                        goto handle_error;
 490                tls_append_frag(record, pfrag, copy);
 491
 492                size -= copy;
 493                if (!size) {
 494last_record:
 495                        tls_push_record_flags = flags;
 496                        if (flags & (MSG_SENDPAGE_NOTLAST | MSG_MORE)) {
 497                                more = true;
 498                                break;
 499                        }
 500
 501                        done = true;
 502                }
 503
 504                if (done || record->len >= max_open_record_len ||
 505                    (record->num_frags >= MAX_SKB_FRAGS - 1)) {
 506                        rc = tls_device_record_close(sk, tls_ctx, record,
 507                                                     pfrag, record_type);
 508                        if (rc) {
 509                                if (rc > 0) {
 510                                        size += rc;
 511                                } else {
 512                                        size = orig_size;
 513                                        destroy_record(record);
 514                                        ctx->open_record = NULL;
 515                                        break;
 516                                }
 517                        }
 518
 519                        rc = tls_push_record(sk,
 520                                             tls_ctx,
 521                                             ctx,
 522                                             record,
 523                                             tls_push_record_flags);
 524                        if (rc < 0)
 525                                break;
 526                }
 527        } while (!done);
 528
 529        tls_ctx->pending_open_record_frags = more;
 530
 531        if (orig_size - size > 0)
 532                rc = orig_size - size;
 533
 534        return rc;
 535}
 536
 537int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
 538{
 539        unsigned char record_type = TLS_RECORD_TYPE_DATA;
 540        struct tls_context *tls_ctx = tls_get_ctx(sk);
 541        int rc;
 542
 543        mutex_lock(&tls_ctx->tx_lock);
 544        lock_sock(sk);
 545
 546        if (unlikely(msg->msg_controllen)) {
 547                rc = tls_proccess_cmsg(sk, msg, &record_type);
 548                if (rc)
 549                        goto out;
 550        }
 551
 552        rc = tls_push_data(sk, &msg->msg_iter, size,
 553                           msg->msg_flags, record_type);
 554
 555out:
 556        release_sock(sk);
 557        mutex_unlock(&tls_ctx->tx_lock);
 558        return rc;
 559}
 560
 561int tls_device_sendpage(struct sock *sk, struct page *page,
 562                        int offset, size_t size, int flags)
 563{
 564        struct tls_context *tls_ctx = tls_get_ctx(sk);
 565        struct iov_iter msg_iter;
 566        char *kaddr;
 567        struct kvec iov;
 568        int rc;
 569
 570        if (flags & MSG_SENDPAGE_NOTLAST)
 571                flags |= MSG_MORE;
 572
 573        mutex_lock(&tls_ctx->tx_lock);
 574        lock_sock(sk);
 575
 576        if (flags & MSG_OOB) {
 577                rc = -EOPNOTSUPP;
 578                goto out;
 579        }
 580
 581        kaddr = kmap(page);
 582        iov.iov_base = kaddr + offset;
 583        iov.iov_len = size;
 584        iov_iter_kvec(&msg_iter, WRITE, &iov, 1, size);
 585        rc = tls_push_data(sk, &msg_iter, size,
 586                           flags, TLS_RECORD_TYPE_DATA);
 587        kunmap(page);
 588
 589out:
 590        release_sock(sk);
 591        mutex_unlock(&tls_ctx->tx_lock);
 592        return rc;
 593}
 594
 595struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context,
 596                                       u32 seq, u64 *p_record_sn)
 597{
 598        u64 record_sn = context->hint_record_sn;
 599        struct tls_record_info *info, *last;
 600
 601        info = context->retransmit_hint;
 602        if (!info ||
 603            before(seq, info->end_seq - info->len)) {
 604                /* if retransmit_hint is irrelevant start
 605                 * from the beginning of the list
 606                 */
 607                info = list_first_entry_or_null(&context->records_list,
 608                                                struct tls_record_info, list);
 609                if (!info)
 610                        return NULL;
 611                /* send the start_marker record if seq number is before the
 612                 * tls offload start marker sequence number. This record is
 613                 * required to handle TCP packets which are before TLS offload
 614                 * started.
 615                 *  And if it's not start marker, look if this seq number
 616                 * belongs to the list.
 617                 */
 618                if (likely(!tls_record_is_start_marker(info))) {
 619                        /* we have the first record, get the last record to see
 620                         * if this seq number belongs to the list.
 621                         */
 622                        last = list_last_entry(&context->records_list,
 623                                               struct tls_record_info, list);
 624
 625                        if (!between(seq, tls_record_start_seq(info),
 626                                     last->end_seq))
 627                                return NULL;
 628                }
 629                record_sn = context->unacked_record_sn;
 630        }
 631
 632        /* We just need the _rcu for the READ_ONCE() */
 633        rcu_read_lock();
 634        list_for_each_entry_from_rcu(info, &context->records_list, list) {
 635                if (before(seq, info->end_seq)) {
 636                        if (!context->retransmit_hint ||
 637                            after(info->end_seq,
 638                                  context->retransmit_hint->end_seq)) {
 639                                context->hint_record_sn = record_sn;
 640                                context->retransmit_hint = info;
 641                        }
 642                        *p_record_sn = record_sn;
 643                        goto exit_rcu_unlock;
 644                }
 645                record_sn++;
 646        }
 647        info = NULL;
 648
 649exit_rcu_unlock:
 650        rcu_read_unlock();
 651        return info;
 652}
 653EXPORT_SYMBOL(tls_get_record);
 654
 655static int tls_device_push_pending_record(struct sock *sk, int flags)
 656{
 657        struct iov_iter msg_iter;
 658
 659        iov_iter_kvec(&msg_iter, WRITE, NULL, 0, 0);
 660        return tls_push_data(sk, &msg_iter, 0, flags, TLS_RECORD_TYPE_DATA);
 661}
 662
 663void tls_device_write_space(struct sock *sk, struct tls_context *ctx)
 664{
 665        if (tls_is_partially_sent_record(ctx)) {
 666                gfp_t sk_allocation = sk->sk_allocation;
 667
 668                WARN_ON_ONCE(sk->sk_write_pending);
 669
 670                sk->sk_allocation = GFP_ATOMIC;
 671                tls_push_partial_record(sk, ctx,
 672                                        MSG_DONTWAIT | MSG_NOSIGNAL |
 673                                        MSG_SENDPAGE_DECRYPTED);
 674                sk->sk_allocation = sk_allocation;
 675        }
 676}
 677
 678static void tls_device_resync_rx(struct tls_context *tls_ctx,
 679                                 struct sock *sk, u32 seq, u8 *rcd_sn)
 680{
 681        struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
 682        struct net_device *netdev;
 683
 684        trace_tls_device_rx_resync_send(sk, seq, rcd_sn, rx_ctx->resync_type);
 685        rcu_read_lock();
 686        netdev = READ_ONCE(tls_ctx->netdev);
 687        if (netdev)
 688                netdev->tlsdev_ops->tls_dev_resync(netdev, sk, seq, rcd_sn,
 689                                                   TLS_OFFLOAD_CTX_DIR_RX);
 690        rcu_read_unlock();
 691        TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSRXDEVICERESYNC);
 692}
 693
 694static bool
 695tls_device_rx_resync_async(struct tls_offload_resync_async *resync_async,
 696                           s64 resync_req, u32 *seq, u16 *rcd_delta)
 697{
 698        u32 is_async = resync_req & RESYNC_REQ_ASYNC;
 699        u32 req_seq = resync_req >> 32;
 700        u32 req_end = req_seq + ((resync_req >> 16) & 0xffff);
 701        u16 i;
 702
 703        *rcd_delta = 0;
 704
 705        if (is_async) {
 706                /* shouldn't get to wraparound:
 707                 * too long in async stage, something bad happened
 708                 */
 709                if (WARN_ON_ONCE(resync_async->rcd_delta == USHRT_MAX))
 710                        return false;
 711
 712                /* asynchronous stage: log all headers seq such that
 713                 * req_seq <= seq <= end_seq, and wait for real resync request
 714                 */
 715                if (before(*seq, req_seq))
 716                        return false;
 717                if (!after(*seq, req_end) &&
 718                    resync_async->loglen < TLS_DEVICE_RESYNC_ASYNC_LOGMAX)
 719                        resync_async->log[resync_async->loglen++] = *seq;
 720
 721                resync_async->rcd_delta++;
 722
 723                return false;
 724        }
 725
 726        /* synchronous stage: check against the logged entries and
 727         * proceed to check the next entries if no match was found
 728         */
 729        for (i = 0; i < resync_async->loglen; i++)
 730                if (req_seq == resync_async->log[i] &&
 731                    atomic64_try_cmpxchg(&resync_async->req, &resync_req, 0)) {
 732                        *rcd_delta = resync_async->rcd_delta - i;
 733                        *seq = req_seq;
 734                        resync_async->loglen = 0;
 735                        resync_async->rcd_delta = 0;
 736                        return true;
 737                }
 738
 739        resync_async->loglen = 0;
 740        resync_async->rcd_delta = 0;
 741
 742        if (req_seq == *seq &&
 743            atomic64_try_cmpxchg(&resync_async->req,
 744                                 &resync_req, 0))
 745                return true;
 746
 747        return false;
 748}
 749
 750void tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq)
 751{
 752        struct tls_context *tls_ctx = tls_get_ctx(sk);
 753        struct tls_offload_context_rx *rx_ctx;
 754        u8 rcd_sn[TLS_MAX_REC_SEQ_SIZE];
 755        u32 sock_data, is_req_pending;
 756        struct tls_prot_info *prot;
 757        s64 resync_req;
 758        u16 rcd_delta;
 759        u32 req_seq;
 760
 761        if (tls_ctx->rx_conf != TLS_HW)
 762                return;
 763        if (unlikely(test_bit(TLS_RX_DEV_DEGRADED, &tls_ctx->flags)))
 764                return;
 765
 766        prot = &tls_ctx->prot_info;
 767        rx_ctx = tls_offload_ctx_rx(tls_ctx);
 768        memcpy(rcd_sn, tls_ctx->rx.rec_seq, prot->rec_seq_size);
 769
 770        switch (rx_ctx->resync_type) {
 771        case TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ:
 772                resync_req = atomic64_read(&rx_ctx->resync_req);
 773                req_seq = resync_req >> 32;
 774                seq += TLS_HEADER_SIZE - 1;
 775                is_req_pending = resync_req;
 776
 777                if (likely(!is_req_pending) || req_seq != seq ||
 778                    !atomic64_try_cmpxchg(&rx_ctx->resync_req, &resync_req, 0))
 779                        return;
 780                break;
 781        case TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT:
 782                if (likely(!rx_ctx->resync_nh_do_now))
 783                        return;
 784
 785                /* head of next rec is already in, note that the sock_inq will
 786                 * include the currently parsed message when called from parser
 787                 */
 788                sock_data = tcp_inq(sk);
 789                if (sock_data > rcd_len) {
 790                        trace_tls_device_rx_resync_nh_delay(sk, sock_data,
 791                                                            rcd_len);
 792                        return;
 793                }
 794
 795                rx_ctx->resync_nh_do_now = 0;
 796                seq += rcd_len;
 797                tls_bigint_increment(rcd_sn, prot->rec_seq_size);
 798                break;
 799        case TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ_ASYNC:
 800                resync_req = atomic64_read(&rx_ctx->resync_async->req);
 801                is_req_pending = resync_req;
 802                if (likely(!is_req_pending))
 803                        return;
 804
 805                if (!tls_device_rx_resync_async(rx_ctx->resync_async,
 806                                                resync_req, &seq, &rcd_delta))
 807                        return;
 808                tls_bigint_subtract(rcd_sn, rcd_delta);
 809                break;
 810        }
 811
 812        tls_device_resync_rx(tls_ctx, sk, seq, rcd_sn);
 813}
 814
 815static void tls_device_core_ctrl_rx_resync(struct tls_context *tls_ctx,
 816                                           struct tls_offload_context_rx *ctx,
 817                                           struct sock *sk, struct sk_buff *skb)
 818{
 819        struct strp_msg *rxm;
 820
 821        /* device will request resyncs by itself based on stream scan */
 822        if (ctx->resync_type != TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT)
 823                return;
 824        /* already scheduled */
 825        if (ctx->resync_nh_do_now)
 826                return;
 827        /* seen decrypted fragments since last fully-failed record */
 828        if (ctx->resync_nh_reset) {
 829                ctx->resync_nh_reset = 0;
 830                ctx->resync_nh.decrypted_failed = 1;
 831                ctx->resync_nh.decrypted_tgt = TLS_DEVICE_RESYNC_NH_START_IVAL;
 832                return;
 833        }
 834
 835        if (++ctx->resync_nh.decrypted_failed <= ctx->resync_nh.decrypted_tgt)
 836                return;
 837
 838        /* doing resync, bump the next target in case it fails */
 839        if (ctx->resync_nh.decrypted_tgt < TLS_DEVICE_RESYNC_NH_MAX_IVAL)
 840                ctx->resync_nh.decrypted_tgt *= 2;
 841        else
 842                ctx->resync_nh.decrypted_tgt += TLS_DEVICE_RESYNC_NH_MAX_IVAL;
 843
 844        rxm = strp_msg(skb);
 845
 846        /* head of next rec is already in, parser will sync for us */
 847        if (tcp_inq(sk) > rxm->full_len) {
 848                trace_tls_device_rx_resync_nh_schedule(sk);
 849                ctx->resync_nh_do_now = 1;
 850        } else {
 851                struct tls_prot_info *prot = &tls_ctx->prot_info;
 852                u8 rcd_sn[TLS_MAX_REC_SEQ_SIZE];
 853
 854                memcpy(rcd_sn, tls_ctx->rx.rec_seq, prot->rec_seq_size);
 855                tls_bigint_increment(rcd_sn, prot->rec_seq_size);
 856
 857                tls_device_resync_rx(tls_ctx, sk, tcp_sk(sk)->copied_seq,
 858                                     rcd_sn);
 859        }
 860}
 861
 862static int tls_device_reencrypt(struct sock *sk, struct sk_buff *skb)
 863{
 864        struct strp_msg *rxm = strp_msg(skb);
 865        int err = 0, offset = rxm->offset, copy, nsg, data_len, pos;
 866        struct sk_buff *skb_iter, *unused;
 867        struct scatterlist sg[1];
 868        char *orig_buf, *buf;
 869
 870        orig_buf = kmalloc(rxm->full_len + TLS_HEADER_SIZE +
 871                           TLS_CIPHER_AES_GCM_128_IV_SIZE, sk->sk_allocation);
 872        if (!orig_buf)
 873                return -ENOMEM;
 874        buf = orig_buf;
 875
 876        nsg = skb_cow_data(skb, 0, &unused);
 877        if (unlikely(nsg < 0)) {
 878                err = nsg;
 879                goto free_buf;
 880        }
 881
 882        sg_init_table(sg, 1);
 883        sg_set_buf(&sg[0], buf,
 884                   rxm->full_len + TLS_HEADER_SIZE +
 885                   TLS_CIPHER_AES_GCM_128_IV_SIZE);
 886        err = skb_copy_bits(skb, offset, buf,
 887                            TLS_HEADER_SIZE + TLS_CIPHER_AES_GCM_128_IV_SIZE);
 888        if (err)
 889                goto free_buf;
 890
 891        /* We are interested only in the decrypted data not the auth */
 892        err = decrypt_skb(sk, skb, sg);
 893        if (err != -EBADMSG)
 894                goto free_buf;
 895        else
 896                err = 0;
 897
 898        data_len = rxm->full_len - TLS_CIPHER_AES_GCM_128_TAG_SIZE;
 899
 900        if (skb_pagelen(skb) > offset) {
 901                copy = min_t(int, skb_pagelen(skb) - offset, data_len);
 902
 903                if (skb->decrypted) {
 904                        err = skb_store_bits(skb, offset, buf, copy);
 905                        if (err)
 906                                goto free_buf;
 907                }
 908
 909                offset += copy;
 910                buf += copy;
 911        }
 912
 913        pos = skb_pagelen(skb);
 914        skb_walk_frags(skb, skb_iter) {
 915                int frag_pos;
 916
 917                /* Practically all frags must belong to msg if reencrypt
 918                 * is needed with current strparser and coalescing logic,
 919                 * but strparser may "get optimized", so let's be safe.
 920                 */
 921                if (pos + skb_iter->len <= offset)
 922                        goto done_with_frag;
 923                if (pos >= data_len + rxm->offset)
 924                        break;
 925
 926                frag_pos = offset - pos;
 927                copy = min_t(int, skb_iter->len - frag_pos,
 928                             data_len + rxm->offset - offset);
 929
 930                if (skb_iter->decrypted) {
 931                        err = skb_store_bits(skb_iter, frag_pos, buf, copy);
 932                        if (err)
 933                                goto free_buf;
 934                }
 935
 936                offset += copy;
 937                buf += copy;
 938done_with_frag:
 939                pos += skb_iter->len;
 940        }
 941
 942free_buf:
 943        kfree(orig_buf);
 944        return err;
 945}
 946
 947int tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx,
 948                         struct sk_buff *skb, struct strp_msg *rxm)
 949{
 950        struct tls_offload_context_rx *ctx = tls_offload_ctx_rx(tls_ctx);
 951        int is_decrypted = skb->decrypted;
 952        int is_encrypted = !is_decrypted;
 953        struct sk_buff *skb_iter;
 954
 955        /* Check if all the data is decrypted already */
 956        skb_walk_frags(skb, skb_iter) {
 957                is_decrypted &= skb_iter->decrypted;
 958                is_encrypted &= !skb_iter->decrypted;
 959        }
 960
 961        trace_tls_device_decrypted(sk, tcp_sk(sk)->copied_seq - rxm->full_len,
 962                                   tls_ctx->rx.rec_seq, rxm->full_len,
 963                                   is_encrypted, is_decrypted);
 964
 965        ctx->sw.decrypted |= is_decrypted;
 966
 967        if (unlikely(test_bit(TLS_RX_DEV_DEGRADED, &tls_ctx->flags))) {
 968                if (likely(is_encrypted || is_decrypted))
 969                        return 0;
 970
 971                /* After tls_device_down disables the offload, the next SKB will
 972                 * likely have initial fragments decrypted, and final ones not
 973                 * decrypted. We need to reencrypt that single SKB.
 974                 */
 975                return tls_device_reencrypt(sk, skb);
 976        }
 977
 978        /* Return immediately if the record is either entirely plaintext or
 979         * entirely ciphertext. Otherwise handle reencrypt partially decrypted
 980         * record.
 981         */
 982        if (is_decrypted) {
 983                ctx->resync_nh_reset = 1;
 984                return 0;
 985        }
 986        if (is_encrypted) {
 987                tls_device_core_ctrl_rx_resync(tls_ctx, ctx, sk, skb);
 988                return 0;
 989        }
 990
 991        ctx->resync_nh_reset = 1;
 992        return tls_device_reencrypt(sk, skb);
 993}
 994
 995static void tls_device_attach(struct tls_context *ctx, struct sock *sk,
 996                              struct net_device *netdev)
 997{
 998        if (sk->sk_destruct != tls_device_sk_destruct) {
 999                refcount_set(&ctx->refcount, 1);
1000                dev_hold(netdev);
1001                ctx->netdev = netdev;
1002                spin_lock_irq(&tls_device_lock);
1003                list_add_tail(&ctx->list, &tls_device_list);
1004                spin_unlock_irq(&tls_device_lock);
1005
1006                ctx->sk_destruct = sk->sk_destruct;
1007                smp_store_release(&sk->sk_destruct, tls_device_sk_destruct);
1008        }
1009}
1010
1011int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
1012{
1013        u16 nonce_size, tag_size, iv_size, rec_seq_size, salt_size;
1014        struct tls_context *tls_ctx = tls_get_ctx(sk);
1015        struct tls_prot_info *prot = &tls_ctx->prot_info;
1016        struct tls_record_info *start_marker_record;
1017        struct tls_offload_context_tx *offload_ctx;
1018        struct tls_crypto_info *crypto_info;
1019        struct net_device *netdev;
1020        char *iv, *rec_seq;
1021        struct sk_buff *skb;
1022        __be64 rcd_sn;
1023        int rc;
1024
1025        if (!ctx)
1026                return -EINVAL;
1027
1028        if (ctx->priv_ctx_tx)
1029                return -EEXIST;
1030
1031        start_marker_record = kmalloc(sizeof(*start_marker_record), GFP_KERNEL);
1032        if (!start_marker_record)
1033                return -ENOMEM;
1034
1035        offload_ctx = kzalloc(TLS_OFFLOAD_CONTEXT_SIZE_TX, GFP_KERNEL);
1036        if (!offload_ctx) {
1037                rc = -ENOMEM;
1038                goto free_marker_record;
1039        }
1040
1041        crypto_info = &ctx->crypto_send.info;
1042        if (crypto_info->version != TLS_1_2_VERSION) {
1043                rc = -EOPNOTSUPP;
1044                goto free_offload_ctx;
1045        }
1046
1047        switch (crypto_info->cipher_type) {
1048        case TLS_CIPHER_AES_GCM_128:
1049                nonce_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
1050                tag_size = TLS_CIPHER_AES_GCM_128_TAG_SIZE;
1051                iv_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
1052                iv = ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->iv;
1053                rec_seq_size = TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE;
1054                salt_size = TLS_CIPHER_AES_GCM_128_SALT_SIZE;
1055                rec_seq =
1056                 ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->rec_seq;
1057                break;
1058        default:
1059                rc = -EINVAL;
1060                goto free_offload_ctx;
1061        }
1062
1063        /* Sanity-check the rec_seq_size for stack allocations */
1064        if (rec_seq_size > TLS_MAX_REC_SEQ_SIZE) {
1065                rc = -EINVAL;
1066                goto free_offload_ctx;
1067        }
1068
1069        prot->version = crypto_info->version;
1070        prot->cipher_type = crypto_info->cipher_type;
1071        prot->prepend_size = TLS_HEADER_SIZE + nonce_size;
1072        prot->tag_size = tag_size;
1073        prot->overhead_size = prot->prepend_size + prot->tag_size;
1074        prot->iv_size = iv_size;
1075        prot->salt_size = salt_size;
1076        ctx->tx.iv = kmalloc(iv_size + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
1077                             GFP_KERNEL);
1078        if (!ctx->tx.iv) {
1079                rc = -ENOMEM;
1080                goto free_offload_ctx;
1081        }
1082
1083        memcpy(ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv, iv_size);
1084
1085        prot->rec_seq_size = rec_seq_size;
1086        ctx->tx.rec_seq = kmemdup(rec_seq, rec_seq_size, GFP_KERNEL);
1087        if (!ctx->tx.rec_seq) {
1088                rc = -ENOMEM;
1089                goto free_iv;
1090        }
1091
1092        rc = tls_sw_fallback_init(sk, offload_ctx, crypto_info);
1093        if (rc)
1094                goto free_rec_seq;
1095
1096        /* start at rec_seq - 1 to account for the start marker record */
1097        memcpy(&rcd_sn, ctx->tx.rec_seq, sizeof(rcd_sn));
1098        offload_ctx->unacked_record_sn = be64_to_cpu(rcd_sn) - 1;
1099
1100        start_marker_record->end_seq = tcp_sk(sk)->write_seq;
1101        start_marker_record->len = 0;
1102        start_marker_record->num_frags = 0;
1103
1104        INIT_LIST_HEAD(&offload_ctx->records_list);
1105        list_add_tail(&start_marker_record->list, &offload_ctx->records_list);
1106        spin_lock_init(&offload_ctx->lock);
1107        sg_init_table(offload_ctx->sg_tx_data,
1108                      ARRAY_SIZE(offload_ctx->sg_tx_data));
1109
1110        clean_acked_data_enable(inet_csk(sk), &tls_icsk_clean_acked);
1111        ctx->push_pending_record = tls_device_push_pending_record;
1112
1113        /* TLS offload is greatly simplified if we don't send
1114         * SKBs where only part of the payload needs to be encrypted.
1115         * So mark the last skb in the write queue as end of record.
1116         */
1117        skb = tcp_write_queue_tail(sk);
1118        if (skb)
1119                TCP_SKB_CB(skb)->eor = 1;
1120
1121        netdev = get_netdev_for_sock(sk);
1122        if (!netdev) {
1123                pr_err_ratelimited("%s: netdev not found\n", __func__);
1124                rc = -EINVAL;
1125                goto disable_cad;
1126        }
1127
1128        if (!(netdev->features & NETIF_F_HW_TLS_TX)) {
1129                rc = -EOPNOTSUPP;
1130                goto release_netdev;
1131        }
1132
1133        /* Avoid offloading if the device is down
1134         * We don't want to offload new flows after
1135         * the NETDEV_DOWN event
1136         *
1137         * device_offload_lock is taken in tls_devices's NETDEV_DOWN
1138         * handler thus protecting from the device going down before
1139         * ctx was added to tls_device_list.
1140         */
1141        down_read(&device_offload_lock);
1142        if (!(netdev->flags & IFF_UP)) {
1143                rc = -EINVAL;
1144                goto release_lock;
1145        }
1146
1147        ctx->priv_ctx_tx = offload_ctx;
1148        rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_TX,
1149                                             &ctx->crypto_send.info,
1150                                             tcp_sk(sk)->write_seq);
1151        trace_tls_device_offload_set(sk, TLS_OFFLOAD_CTX_DIR_TX,
1152                                     tcp_sk(sk)->write_seq, rec_seq, rc);
1153        if (rc)
1154                goto release_lock;
1155
1156        tls_device_attach(ctx, sk, netdev);
1157        up_read(&device_offload_lock);
1158
1159        /* following this assignment tls_is_sk_tx_device_offloaded
1160         * will return true and the context might be accessed
1161         * by the netdev's xmit function.
1162         */
1163        smp_store_release(&sk->sk_validate_xmit_skb, tls_validate_xmit_skb);
1164        dev_put(netdev);
1165
1166        return 0;
1167
1168release_lock:
1169        up_read(&device_offload_lock);
1170release_netdev:
1171        dev_put(netdev);
1172disable_cad:
1173        clean_acked_data_disable(inet_csk(sk));
1174        crypto_free_aead(offload_ctx->aead_send);
1175free_rec_seq:
1176        kfree(ctx->tx.rec_seq);
1177free_iv:
1178        kfree(ctx->tx.iv);
1179free_offload_ctx:
1180        kfree(offload_ctx);
1181        ctx->priv_ctx_tx = NULL;
1182free_marker_record:
1183        kfree(start_marker_record);
1184        return rc;
1185}
1186
1187int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
1188{
1189        struct tls12_crypto_info_aes_gcm_128 *info;
1190        struct tls_offload_context_rx *context;
1191        struct net_device *netdev;
1192        int rc = 0;
1193
1194        if (ctx->crypto_recv.info.version != TLS_1_2_VERSION)
1195                return -EOPNOTSUPP;
1196
1197        netdev = get_netdev_for_sock(sk);
1198        if (!netdev) {
1199                pr_err_ratelimited("%s: netdev not found\n", __func__);
1200                return -EINVAL;
1201        }
1202
1203        if (!(netdev->features & NETIF_F_HW_TLS_RX)) {
1204                rc = -EOPNOTSUPP;
1205                goto release_netdev;
1206        }
1207
1208        /* Avoid offloading if the device is down
1209         * We don't want to offload new flows after
1210         * the NETDEV_DOWN event
1211         *
1212         * device_offload_lock is taken in tls_devices's NETDEV_DOWN
1213         * handler thus protecting from the device going down before
1214         * ctx was added to tls_device_list.
1215         */
1216        down_read(&device_offload_lock);
1217        if (!(netdev->flags & IFF_UP)) {
1218                rc = -EINVAL;
1219                goto release_lock;
1220        }
1221
1222        context = kzalloc(TLS_OFFLOAD_CONTEXT_SIZE_RX, GFP_KERNEL);
1223        if (!context) {
1224                rc = -ENOMEM;
1225                goto release_lock;
1226        }
1227        context->resync_nh_reset = 1;
1228
1229        ctx->priv_ctx_rx = context;
1230        rc = tls_set_sw_offload(sk, ctx, 0);
1231        if (rc)
1232                goto release_ctx;
1233
1234        rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_RX,
1235                                             &ctx->crypto_recv.info,
1236                                             tcp_sk(sk)->copied_seq);
1237        info = (void *)&ctx->crypto_recv.info;
1238        trace_tls_device_offload_set(sk, TLS_OFFLOAD_CTX_DIR_RX,
1239                                     tcp_sk(sk)->copied_seq, info->rec_seq, rc);
1240        if (rc)
1241                goto free_sw_resources;
1242
1243        tls_device_attach(ctx, sk, netdev);
1244        up_read(&device_offload_lock);
1245
1246        dev_put(netdev);
1247
1248        return 0;
1249
1250free_sw_resources:
1251        up_read(&device_offload_lock);
1252        tls_sw_free_resources_rx(sk);
1253        down_read(&device_offload_lock);
1254release_ctx:
1255        ctx->priv_ctx_rx = NULL;
1256release_lock:
1257        up_read(&device_offload_lock);
1258release_netdev:
1259        dev_put(netdev);
1260        return rc;
1261}
1262
1263void tls_device_offload_cleanup_rx(struct sock *sk)
1264{
1265        struct tls_context *tls_ctx = tls_get_ctx(sk);
1266        struct net_device *netdev;
1267
1268        down_read(&device_offload_lock);
1269        netdev = tls_ctx->netdev;
1270        if (!netdev)
1271                goto out;
1272
1273        netdev->tlsdev_ops->tls_dev_del(netdev, tls_ctx,
1274                                        TLS_OFFLOAD_CTX_DIR_RX);
1275
1276        if (tls_ctx->tx_conf != TLS_HW) {
1277                dev_put(netdev);
1278                tls_ctx->netdev = NULL;
1279        } else {
1280                set_bit(TLS_RX_DEV_CLOSED, &tls_ctx->flags);
1281        }
1282out:
1283        up_read(&device_offload_lock);
1284        tls_sw_release_resources_rx(sk);
1285}
1286
1287static int tls_device_down(struct net_device *netdev)
1288{
1289        struct tls_context *ctx, *tmp;
1290        unsigned long flags;
1291        LIST_HEAD(list);
1292
1293        /* Request a write lock to block new offload attempts */
1294        down_write(&device_offload_lock);
1295
1296        spin_lock_irqsave(&tls_device_lock, flags);
1297        list_for_each_entry_safe(ctx, tmp, &tls_device_list, list) {
1298                if (ctx->netdev != netdev ||
1299                    !refcount_inc_not_zero(&ctx->refcount))
1300                        continue;
1301
1302                list_move(&ctx->list, &list);
1303        }
1304        spin_unlock_irqrestore(&tls_device_lock, flags);
1305
1306        list_for_each_entry_safe(ctx, tmp, &list, list) {
1307                /* Stop offloaded TX and switch to the fallback.
1308                 * tls_is_sk_tx_device_offloaded will return false.
1309                 */
1310                WRITE_ONCE(ctx->sk->sk_validate_xmit_skb, tls_validate_xmit_skb_sw);
1311
1312                /* Stop the RX and TX resync.
1313                 * tls_dev_resync must not be called after tls_dev_del.
1314                 */
1315                WRITE_ONCE(ctx->netdev, NULL);
1316
1317                /* Start skipping the RX resync logic completely. */
1318                set_bit(TLS_RX_DEV_DEGRADED, &ctx->flags);
1319
1320                /* Sync with inflight packets. After this point:
1321                 * TX: no non-encrypted packets will be passed to the driver.
1322                 * RX: resync requests from the driver will be ignored.
1323                 */
1324                synchronize_net();
1325
1326                /* Release the offload context on the driver side. */
1327                if (ctx->tx_conf == TLS_HW)
1328                        netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
1329                                                        TLS_OFFLOAD_CTX_DIR_TX);
1330                if (ctx->rx_conf == TLS_HW &&
1331                    !test_bit(TLS_RX_DEV_CLOSED, &ctx->flags))
1332                        netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
1333                                                        TLS_OFFLOAD_CTX_DIR_RX);
1334
1335                dev_put(netdev);
1336
1337                /* Move the context to a separate list for two reasons:
1338                 * 1. When the context is deallocated, list_del is called.
1339                 * 2. It's no longer an offloaded context, so we don't want to
1340                 *    run offload-specific code on this context.
1341                 */
1342                spin_lock_irqsave(&tls_device_lock, flags);
1343                list_move_tail(&ctx->list, &tls_device_down_list);
1344                spin_unlock_irqrestore(&tls_device_lock, flags);
1345
1346                /* Device contexts for RX and TX will be freed in on sk_destruct
1347                 * by tls_device_free_ctx. rx_conf and tx_conf stay in TLS_HW.
1348                 */
1349        }
1350
1351        up_write(&device_offload_lock);
1352
1353        flush_work(&tls_device_gc_work);
1354
1355        return NOTIFY_DONE;
1356}
1357
1358static int tls_dev_event(struct notifier_block *this, unsigned long event,
1359                         void *ptr)
1360{
1361        struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1362
1363        if (!dev->tlsdev_ops &&
1364            !(dev->features & (NETIF_F_HW_TLS_RX | NETIF_F_HW_TLS_TX)))
1365                return NOTIFY_DONE;
1366
1367        switch (event) {
1368        case NETDEV_REGISTER:
1369        case NETDEV_FEAT_CHANGE:
1370                if (netif_is_bond_master(dev))
1371                        return NOTIFY_DONE;
1372                if ((dev->features & NETIF_F_HW_TLS_RX) &&
1373                    !dev->tlsdev_ops->tls_dev_resync)
1374                        return NOTIFY_BAD;
1375
1376                if  (dev->tlsdev_ops &&
1377                     dev->tlsdev_ops->tls_dev_add &&
1378                     dev->tlsdev_ops->tls_dev_del)
1379                        return NOTIFY_DONE;
1380                else
1381                        return NOTIFY_BAD;
1382        case NETDEV_DOWN:
1383                return tls_device_down(dev);
1384        }
1385        return NOTIFY_DONE;
1386}
1387
1388static struct notifier_block tls_dev_notifier = {
1389        .notifier_call  = tls_dev_event,
1390};
1391
1392void __init tls_device_init(void)
1393{
1394        register_netdevice_notifier(&tls_dev_notifier);
1395}
1396
1397void __exit tls_device_cleanup(void)
1398{
1399        unregister_netdevice_notifier(&tls_dev_notifier);
1400        flush_work(&tls_device_gc_work);
1401        clean_acked_data_flush();
1402}
1403
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