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 tls_offload_context_rx *rx_ctx;
 557         struct net_device *netdev;
 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                 seq += TLS_HEADER_SIZE - 1;
 573                 down_read(&device_offload_lock);
 574                 netdev = tls_ctx->netdev;
 575                 if (netdev)
 576                         netdev->tlsdev_ops->tls_dev_resync_rx(netdev, sk, seq,
 577                                                               rcd_sn);
 578                 up_read(&device_offload_lock);
 579         }
 580 }
 581
 582 static int tls_device_reencrypt(struct sock *sk, struct sk_buff *skb)
 583 {
 584         struct strp_msg *rxm = strp_msg(skb);
 585         int err = 0, offset = rxm->offset, copy, nsg, data_len, pos;
 586         struct sk_buff *skb_iter, *unused;
 587         struct scatterlist sg[1];
 588         char *orig_buf, *buf;
 589
 590         orig_buf = kmalloc(rxm->full_len + TLS_HEADER_SIZE +
 591                            TLS_CIPHER_AES_GCM_128_IV_SIZE, sk->sk_allocation);
 592         if (!orig_buf)
 593                 return -ENOMEM;
 594         buf = orig_buf;
 595
 596         nsg = skb_cow_data(skb, 0, &unused);
 597         if (unlikely(nsg < 0)) {
 598                 err = nsg;
 599                 goto free_buf;
 600         }
 601
 602         sg_init_table(sg, 1);
 603         sg_set_buf(&sg[0], buf,
 604                    rxm->full_len + TLS_HEADER_SIZE +
 605                    TLS_CIPHER_AES_GCM_128_IV_SIZE);
 606         skb_copy_bits(skb, offset, buf,
 607                       TLS_HEADER_SIZE + TLS_CIPHER_AES_GCM_128_IV_SIZE);
 608
 609         /* We are interested only in the decrypted data not the auth */
 610         err = decrypt_skb(sk, skb, sg);
 611         if (err != -EBADMSG)
 612                 goto free_buf;
 613         else
 614                 err = 0;
 615
 616         data_len = rxm->full_len - TLS_CIPHER_AES_GCM_128_TAG_SIZE;
 617
 618         if (skb_pagelen(skb) > offset) {
 619                 copy = min_t(int, skb_pagelen(skb) - offset, data_len);
 620
 621                 if (skb->decrypted)
 622                         skb_store_bits(skb, offset, buf, copy);
 623
 624                 offset += copy;
 625                 buf += copy;
 626         }
 627
 628         pos = skb_pagelen(skb);
 629         skb_walk_frags(skb, skb_iter) {
 630                 int frag_pos;
 631
 632                 /* Practically all frags must belong to msg if reencrypt
 633                  * is needed with current strparser and coalescing logic,
 634                  * but strparser may "get optimized", so let's be safe.
 635                  */
 636                 if (pos + skb_iter->len <= offset)
 637                         goto done_with_frag;
 638                 if (pos >= data_len + rxm->offset)
 639                         break;
 640
 641                 frag_pos = offset - pos;
 642                 copy = min_t(int, skb_iter->len - frag_pos,
 643                              data_len + rxm->offset - offset);
 644
 645                 if (skb_iter->decrypted)
 646                         skb_store_bits(skb_iter, frag_pos, buf, copy);
 647
 648                 offset += copy;
 649                 buf += copy;
 650 done_with_frag:
 651                 pos += skb_iter->len;
 652         }
 653
 654 free_buf:
 655         kfree(orig_buf);
 656         return err;
 657 }
 658
 659 int tls_device_decrypted(struct sock *sk, struct sk_buff *skb)
 660 {
 661         struct tls_context *tls_ctx = tls_get_ctx(sk);
 662         struct tls_offload_context_rx *ctx = tls_offload_ctx_rx(tls_ctx);
 663         int is_decrypted = skb->decrypted;
 664         int is_encrypted = !is_decrypted;
 665         struct sk_buff *skb_iter;
 666
 667         /* Skip if it is already decrypted */
 668         if (ctx->sw.decrypted)
 669                 return 0;
 670
 671         /* Check if all the data is decrypted already */
 672         skb_walk_frags(skb, skb_iter) {
 673                 is_decrypted &= skb_iter->decrypted;
 674                 is_encrypted &= !skb_iter->decrypted;
 675         }
 676
 677         ctx->sw.decrypted |= is_decrypted;
 678
 679         /* Return immedeatly if the record is either entirely plaintext or
 680          * entirely ciphertext. Otherwise handle reencrypt partially decrypted
 681          * record.
 682          */
 683         return (is_encrypted || is_decrypted) ? 0 :
 684                 tls_device_reencrypt(sk, skb);
 685 }
 686
 687 static void tls_device_attach(struct tls_context *ctx, struct sock *sk,
 688                               struct net_device *netdev)
 689 {
 690         if (sk->sk_destruct != tls_device_sk_destruct) {
 691                 refcount_set(&ctx->refcount, 1);
 692                 dev_hold(netdev);
 693                 ctx->netdev = netdev;
 694                 spin_lock_irq(&tls_device_lock);
 695                 list_add_tail(&ctx->list, &tls_device_list);
 696                 spin_unlock_irq(&tls_device_lock);
 697
 698                 ctx->sk_destruct = sk->sk_destruct;
 699                 sk->sk_destruct = tls_device_sk_destruct;
 700         }
 701 }
 702
 703 int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
 704 {
 705         u16 nonce_size, tag_size, iv_size, rec_seq_size;
 706         struct tls_context *tls_ctx = tls_get_ctx(sk);
 707         struct tls_prot_info *prot = &tls_ctx->prot_info;
 708         struct tls_record_info *start_marker_record;
 709         struct tls_offload_context_tx *offload_ctx;
 710         struct tls_crypto_info *crypto_info;
 711         struct net_device *netdev;
 712         char *iv, *rec_seq;
 713         struct sk_buff *skb;
 714         int rc = -EINVAL;
 715         __be64 rcd_sn;
 716
 717         if (!ctx)
 718                 goto out;
 719
 720         if (ctx->priv_ctx_tx) {
 721                 rc = -EEXIST;
 722                 goto out;
 723         }
 724
 725         start_marker_record = kmalloc(sizeof(*start_marker_record), GFP_KERNEL);
 726         if (!start_marker_record) {
 727                 rc = -ENOMEM;
 728                 goto out;
 729         }
 730
 731         offload_ctx = kzalloc(TLS_OFFLOAD_CONTEXT_SIZE_TX, GFP_KERNEL);
 732         if (!offload_ctx) {
 733                 rc = -ENOMEM;
 734                 goto free_marker_record;
 735         }
 736
 737         crypto_info = &ctx->crypto_send.info;
 738         switch (crypto_info->cipher_type) {
 739         case TLS_CIPHER_AES_GCM_128:
 740                 nonce_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
 741                 tag_size = TLS_CIPHER_AES_GCM_128_TAG_SIZE;
 742                 iv_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
 743                 iv = ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->iv;
 744                 rec_seq_size = TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE;
 745                 rec_seq =
 746                  ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->rec_seq;
 747                 break;
 748         default:
 749                 rc = -EINVAL;
 750                 goto free_offload_ctx;
 751         }
 752
 753         prot->prepend_size = TLS_HEADER_SIZE + nonce_size;
 754         prot->tag_size = tag_size;
 755         prot->overhead_size = prot->prepend_size + prot->tag_size;
 756         prot->iv_size = iv_size;
 757         ctx->tx.iv = kmalloc(iv_size + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
 758                              GFP_KERNEL);
 759         if (!ctx->tx.iv) {
 760                 rc = -ENOMEM;
 761                 goto free_offload_ctx;
 762         }
 763
 764         memcpy(ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv, iv_size);
 765
 766         prot->rec_seq_size = rec_seq_size;
 767         ctx->tx.rec_seq = kmemdup(rec_seq, rec_seq_size, GFP_KERNEL);
 768         if (!ctx->tx.rec_seq) {
 769                 rc = -ENOMEM;
 770                 goto free_iv;
 771         }
 772
 773         rc = tls_sw_fallback_init(sk, offload_ctx, crypto_info);
 774         if (rc)
 775                 goto free_rec_seq;
 776
 777         /* start at rec_seq - 1 to account for the start marker record */
 778         memcpy(&rcd_sn, ctx->tx.rec_seq, sizeof(rcd_sn));
 779         offload_ctx->unacked_record_sn = be64_to_cpu(rcd_sn) - 1;
 780
 781         start_marker_record->end_seq = tcp_sk(sk)->write_seq;
 782         start_marker_record->len = 0;
 783         start_marker_record->num_frags = 0;
 784
 785         INIT_LIST_HEAD(&offload_ctx->records_list);
 786         list_add_tail(&start_marker_record->list, &offload_ctx->records_list);
 787         spin_lock_init(&offload_ctx->lock);
 788         sg_init_table(offload_ctx->sg_tx_data,
 789                       ARRAY_SIZE(offload_ctx->sg_tx_data));
 790
 791         clean_acked_data_enable(inet_csk(sk), &tls_icsk_clean_acked);
 792         ctx->push_pending_record = tls_device_push_pending_record;
 793
 794         /* TLS offload is greatly simplified if we don't send
 795          * SKBs where only part of the payload needs to be encrypted.
 796          * So mark the last skb in the write queue as end of record.
 797          */
 798         skb = tcp_write_queue_tail(sk);
 799         if (skb)
 800                 TCP_SKB_CB(skb)->eor = 1;
 801
 802         /* We support starting offload on multiple sockets
 803          * concurrently, so we only need a read lock here.
 804          * This lock must precede get_netdev_for_sock to prevent races between
 805          * NETDEV_DOWN and setsockopt.
 806          */
 807         down_read(&device_offload_lock);
 808         netdev = get_netdev_for_sock(sk);
 809         if (!netdev) {
 810                 pr_err_ratelimited("%s: netdev not found\n", __func__);
 811                 rc = -EINVAL;
 812                 goto release_lock;
 813         }
 814
 815         if (!(netdev->features & NETIF_F_HW_TLS_TX)) {
 816                 rc = -ENOTSUPP;
 817                 goto release_netdev;
 818         }
 819
 820         /* Avoid offloading if the device is down
 821          * We don't want to offload new flows after
 822          * the NETDEV_DOWN event
 823          */
 824         if (!(netdev->flags & IFF_UP)) {
 825                 rc = -EINVAL;
 826                 goto release_netdev;
 827         }
 828
 829         ctx->priv_ctx_tx = offload_ctx;
 830         rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_TX,
 831                                              &ctx->crypto_send.info,
 832                                              tcp_sk(sk)->write_seq);
 833         if (rc)
 834                 goto release_netdev;
 835
 836         tls_device_attach(ctx, sk, netdev);
 837
 838         /* following this assignment tls_is_sk_tx_device_offloaded
 839          * will return true and the context might be accessed
 840          * by the netdev's xmit function.
 841          */
 842         smp_store_release(&sk->sk_validate_xmit_skb, tls_validate_xmit_skb);
 843         dev_put(netdev);
 844         up_read(&device_offload_lock);
 845         goto out;
 846
 847 release_netdev:
 848         dev_put(netdev);
 849 release_lock:
 850         up_read(&device_offload_lock);
 851         clean_acked_data_disable(inet_csk(sk));
 852         crypto_free_aead(offload_ctx->aead_send);
 853 free_rec_seq:
 854         kfree(ctx->tx.rec_seq);
 855 free_iv:
 856         kfree(ctx->tx.iv);
 857 free_offload_ctx:
 858         kfree(offload_ctx);
 859         ctx->priv_ctx_tx = NULL;
 860 free_marker_record:
 861         kfree(start_marker_record);
 862 out:
 863         return rc;
 864 }
 865
 866 int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
 867 {
 868         struct tls_offload_context_rx *context;
 869         struct net_device *netdev;
 870         int rc = 0;
 871
 872         /* We support starting offload on multiple sockets
 873          * concurrently, so we only need a read lock here.
 874          * This lock must precede get_netdev_for_sock to prevent races between
 875          * NETDEV_DOWN and setsockopt.
 876          */
 877         down_read(&device_offload_lock);
 878         netdev = get_netdev_for_sock(sk);
 879         if (!netdev) {
 880                 pr_err_ratelimited("%s: netdev not found\n", __func__);
 881                 rc = -EINVAL;
 882                 goto release_lock;
 883         }
 884
 885         if (!(netdev->features & NETIF_F_HW_TLS_RX)) {
 886                 rc = -ENOTSUPP;
 887                 goto release_netdev;
 888         }
 889
 890         /* Avoid offloading if the device is down
 891          * We don't want to offload new flows after
 892          * the NETDEV_DOWN event
 893          */
 894         if (!(netdev->flags & IFF_UP)) {
 895                 rc = -EINVAL;
 896                 goto release_netdev;
 897         }
 898
 899         context = kzalloc(TLS_OFFLOAD_CONTEXT_SIZE_RX, GFP_KERNEL);
 900         if (!context) {
 901                 rc = -ENOMEM;
 902                 goto release_netdev;
 903         }
 904
 905         ctx->priv_ctx_rx = context;
 906         rc = tls_set_sw_offload(sk, ctx, 0);
 907         if (rc)
 908                 goto release_ctx;
 909
 910         rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_RX,
 911                                              &ctx->crypto_recv.info,
 912                                              tcp_sk(sk)->copied_seq);
 913         if (rc)
 914                 goto free_sw_resources;
 915
 916         tls_device_attach(ctx, sk, netdev);
 917         goto release_netdev;
 918
 919 free_sw_resources:
 920         up_read(&device_offload_lock);
 921         tls_sw_free_resources_rx(sk);
 922         down_read(&device_offload_lock);
 923 release_ctx:
 924         ctx->priv_ctx_rx = NULL;
 925 release_netdev:
 926         dev_put(netdev);
 927 release_lock:
 928         up_read(&device_offload_lock);
 929         return rc;
 930 }
 931
 932 void tls_device_offload_cleanup_rx(struct sock *sk)
 933 {
 934         struct tls_context *tls_ctx = tls_get_ctx(sk);
 935         struct net_device *netdev;
 936
 937         down_read(&device_offload_lock);
 938         netdev = tls_ctx->netdev;
 939         if (!netdev)
 940                 goto out;
 941
 942         if (!(netdev->features & NETIF_F_HW_TLS_RX)) {
 943                 pr_err_ratelimited("%s: device is missing NETIF_F_HW_TLS_RX cap\n",
 944                                    __func__);
 945                 goto out;
 946         }
 947
 948         netdev->tlsdev_ops->tls_dev_del(netdev, tls_ctx,
 949                                         TLS_OFFLOAD_CTX_DIR_RX);
 950
 951         if (tls_ctx->tx_conf != TLS_HW) {
 952                 dev_put(netdev);
 953                 tls_ctx->netdev = NULL;
 954         }
 955 out:
 956         up_read(&device_offload_lock);
 957         tls_sw_release_resources_rx(sk);
 958 }
 959
 960 static int tls_device_down(struct net_device *netdev)
 961 {
 962         struct tls_context *ctx, *tmp;
 963         unsigned long flags;
 964         LIST_HEAD(list);
 965
 966         /* Request a write lock to block new offload attempts */
 967         down_write(&device_offload_lock);
 968
 969         spin_lock_irqsave(&tls_device_lock, flags);
 970         list_for_each_entry_safe(ctx, tmp, &tls_device_list, list) {
 971                 if (ctx->netdev != netdev ||
 972                     !refcount_inc_not_zero(&ctx->refcount))
 973                         continue;
 974
 975                 list_move(&ctx->list, &list);
 976         }
 977         spin_unlock_irqrestore(&tls_device_lock, flags);
 978
 979         list_for_each_entry_safe(ctx, tmp, &list, list) {
 980                 if (ctx->tx_conf == TLS_HW)
 981                         netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
 982                                                         TLS_OFFLOAD_CTX_DIR_TX);
 983                 if (ctx->rx_conf == TLS_HW)
 984                         netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
 985                                                         TLS_OFFLOAD_CTX_DIR_RX);
 986                 ctx->netdev = NULL;
 987                 dev_put(netdev);
 988                 list_del_init(&ctx->list);
 989
 990                 if (refcount_dec_and_test(&ctx->refcount))
 991                         tls_device_free_ctx(ctx);
 992         }
 993
 994         up_write(&device_offload_lock);
 995
 996         flush_work(&tls_device_gc_work);
 997
 998         return NOTIFY_DONE;
 999 }
1000
1001 static int tls_dev_event(struct notifier_block *this, unsigned long event,
1002                          void *ptr)
1003 {
1004         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1005
1006         if (!(dev->features & (NETIF_F_HW_TLS_RX | NETIF_F_HW_TLS_TX)))
1007                 return NOTIFY_DONE;
1008
1009         switch (event) {
1010         case NETDEV_REGISTER:
1011         case NETDEV_FEAT_CHANGE:
1012                 if ((dev->features & NETIF_F_HW_TLS_RX) &&
1013                     !dev->tlsdev_ops->tls_dev_resync_rx)
1014                         return NOTIFY_BAD;
1015
1016                 if  (dev->tlsdev_ops &&
1017                      dev->tlsdev_ops->tls_dev_add &&
1018                      dev->tlsdev_ops->tls_dev_del)
1019                         return NOTIFY_DONE;
1020                 else
1021                         return NOTIFY_BAD;
1022         case NETDEV_DOWN:
1023                 return tls_device_down(dev);
1024         }
1025         return NOTIFY_DONE;
1026 }
1027
1028 static struct notifier_block tls_dev_notifier = {
1029         .notifier_call  = tls_dev_event,
1030 };
1031
1032 void __init tls_device_init(void)
1033 {
1034         register_netdevice_notifier(&tls_dev_notifier);
1035 }
1036
1037 void __exit tls_device_cleanup(void)
1038 {
1039         unregister_netdevice_notifier(&tls_dev_notifier);
1040         flush_work(&tls_device_gc_work);
1041         clean_acked_data_flush();
1042 }