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