net/tls/tls_sw.c

   1 /*
   2  * Copyright (c) 2016-2017, Mellanox Technologies. All rights reserved.
   3  * Copyright (c) 2016-2017, Dave Watson <davejwatson@fb.com>. All rights reserved.
   4  * Copyright (c) 2016-2017, Lance Chao <lancerchao@fb.com>. All rights reserved.
   5  * Copyright (c) 2016, Fridolin Pokorny <fridolin.pokorny@gmail.com>. All rights reserved.
   6  * Copyright (c) 2016, Nikos Mavrogiannopoulos <nmav@gnutls.org>. All rights reserved.
   7  *
   8  * This software is available to you under a choice of one of two
   9  * licenses.  You may choose to be licensed under the terms of the GNU
  10  * General Public License (GPL) Version 2, available from the file
  11  * COPYING in the main directory of this source tree, or the
  12  * OpenIB.org BSD license below:
  13  *
  14  *     Redistribution and use in source and binary forms, with or
  15  *     without modification, are permitted provided that the following
  16  *     conditions are met:
  17  *
  18  *      - Redistributions of source code must retain the above
  19  *        copyright notice, this list of conditions and the following
  20  *        disclaimer.
  21  *
  22  *      - Redistributions in binary form must reproduce the above
  23  *        copyright notice, this list of conditions and the following
  24  *        disclaimer in the documentation and/or other materials
  25  *        provided with the distribution.
  26  *
  27  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  28  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  29  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  30  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  31  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  32  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  33  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  34  * SOFTWARE.
  35  */
  36
  37 #include <linux/module.h>
  38 #include <crypto/aead.h>
  39
  40 #include <net/tls.h>
  41
  42 static inline void tls_make_aad(int recv,
  43                                 char *buf,
  44                                 size_t size,
  45                                 char *record_sequence,
  46                                 int record_sequence_size,
  47                                 unsigned char record_type)
  48 {
  49         memcpy(buf, record_sequence, record_sequence_size);
  50
  51         buf[8] = record_type;
  52         buf[9] = TLS_1_2_VERSION_MAJOR;
  53         buf[10] = TLS_1_2_VERSION_MINOR;
  54         buf[11] = size >> 8;
  55         buf[12] = size & 0xFF;
  56 }
  57
  58 static void trim_sg(struct sock *sk, struct scatterlist *sg,
  59                     int *sg_num_elem, unsigned int *sg_size, int target_size)
  60 {
  61         int i = *sg_num_elem - 1;
  62         int trim = *sg_size - target_size;
  63
  64         if (trim <= 0) {
  65                 WARN_ON(trim < 0);
  66                 return;
  67         }
  68
  69         *sg_size = target_size;
  70         while (trim >= sg[i].length) {
  71                 trim -= sg[i].length;
  72                 sk_mem_uncharge(sk, sg[i].length);
  73                 put_page(sg_page(&sg[i]));
  74                 i--;
  75
  76                 if (i < 0)
  77                         goto out;
  78         }
  79
  80         sg[i].length -= trim;
  81         sk_mem_uncharge(sk, trim);
  82
  83 out:
  84         *sg_num_elem = i + 1;
  85 }
  86
  87 static void trim_both_sgl(struct sock *sk, int target_size)
  88 {
  89         struct tls_context *tls_ctx = tls_get_ctx(sk);
  90         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
  91
  92         trim_sg(sk, ctx->sg_plaintext_data,
  93                 &ctx->sg_plaintext_num_elem,
  94                 &ctx->sg_plaintext_size,
  95                 target_size);
  96
  97         if (target_size > 0)
  98                 target_size += tls_ctx->overhead_size;
  99
 100         trim_sg(sk, ctx->sg_encrypted_data,
 101                 &ctx->sg_encrypted_num_elem,
 102                 &ctx->sg_encrypted_size,
 103                 target_size);
 104 }
 105
 106 static int alloc_sg(struct sock *sk, int len, struct scatterlist *sg,
 107                     int *sg_num_elem, unsigned int *sg_size,
 108                     int first_coalesce)
 109 {
 110         struct page_frag *pfrag;
 111         unsigned int size = *sg_size;
 112         int num_elem = *sg_num_elem, use = 0, rc = 0;
 113         struct scatterlist *sge;
 114         unsigned int orig_offset;
 115
 116         len -= size;
 117         pfrag = sk_page_frag(sk);
 118
 119         while (len > 0) {
 120                 if (!sk_page_frag_refill(sk, pfrag)) {
 121                         rc = -ENOMEM;
 122                         goto out;
 123                 }
 124
 125                 use = min_t(int, len, pfrag->size - pfrag->offset);
 126
 127                 if (!sk_wmem_schedule(sk, use)) {
 128                         rc = -ENOMEM;
 129                         goto out;
 130                 }
 131
 132                 sk_mem_charge(sk, use);
 133                 size += use;
 134                 orig_offset = pfrag->offset;
 135                 pfrag->offset += use;
 136
 137                 sge = sg + num_elem - 1;
 138                 if (num_elem > first_coalesce && sg_page(sg) == pfrag->page &&
 139                     sg->offset + sg->length == orig_offset) {
 140                         sg->length += use;
 141                 } else {
 142                         sge++;
 143                         sg_unmark_end(sge);
 144                         sg_set_page(sge, pfrag->page, use, orig_offset);
 145                         get_page(pfrag->page);
 146                         ++num_elem;
 147                         if (num_elem == MAX_SKB_FRAGS) {
 148                                 rc = -ENOSPC;
 149                                 break;
 150                         }
 151                 }
 152
 153                 len -= use;
 154         }
 155         goto out;
 156
 157 out:
 158         *sg_size = size;
 159         *sg_num_elem = num_elem;
 160         return rc;
 161 }
 162
 163 static int alloc_encrypted_sg(struct sock *sk, int len)
 164 {
 165         struct tls_context *tls_ctx = tls_get_ctx(sk);
 166         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
 167         int rc = 0;
 168
 169         rc = alloc_sg(sk, len, ctx->sg_encrypted_data,
 170                       &ctx->sg_encrypted_num_elem, &ctx->sg_encrypted_size, 0);
 171
 172         return rc;
 173 }
 174
 175 static int alloc_plaintext_sg(struct sock *sk, int len)
 176 {
 177         struct tls_context *tls_ctx = tls_get_ctx(sk);
 178         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
 179         int rc = 0;
 180
 181         rc = alloc_sg(sk, len, ctx->sg_plaintext_data,
 182                       &ctx->sg_plaintext_num_elem, &ctx->sg_plaintext_size,
 183                       tls_ctx->pending_open_record_frags);
 184
 185         return rc;
 186 }
 187
 188 static void free_sg(struct sock *sk, struct scatterlist *sg,
 189                     int *sg_num_elem, unsigned int *sg_size)
 190 {
 191         int i, n = *sg_num_elem;
 192
 193         for (i = 0; i < n; ++i) {
 194                 sk_mem_uncharge(sk, sg[i].length);
 195                 put_page(sg_page(&sg[i]));
 196         }
 197         *sg_num_elem = 0;
 198         *sg_size = 0;
 199 }
 200
 201 static void tls_free_both_sg(struct sock *sk)
 202 {
 203         struct tls_context *tls_ctx = tls_get_ctx(sk);
 204         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
 205
 206         free_sg(sk, ctx->sg_encrypted_data, &ctx->sg_encrypted_num_elem,
 207                 &ctx->sg_encrypted_size);
 208
 209         free_sg(sk, ctx->sg_plaintext_data, &ctx->sg_plaintext_num_elem,
 210                 &ctx->sg_plaintext_size);
 211 }
 212
 213 static int tls_do_encryption(struct tls_context *tls_ctx,
 214                              struct tls_sw_context *ctx, size_t data_len,
 215                              gfp_t flags)
 216 {
 217         unsigned int req_size = sizeof(struct aead_request) +
 218                 crypto_aead_reqsize(ctx->aead_send);
 219         struct aead_request *aead_req;
 220         int rc;
 221
 222         aead_req = kmalloc(req_size, flags);
 223         if (!aead_req)
 224                 return -ENOMEM;
 225
 226         ctx->sg_encrypted_data[0].offset += tls_ctx->prepend_size;
 227         ctx->sg_encrypted_data[0].length -= tls_ctx->prepend_size;
 228
 229         aead_request_set_tfm(aead_req, ctx->aead_send);
 230         aead_request_set_ad(aead_req, TLS_AAD_SPACE_SIZE);
 231         aead_request_set_crypt(aead_req, ctx->sg_aead_in, ctx->sg_aead_out,
 232                                data_len, tls_ctx->iv);
 233         rc = crypto_aead_encrypt(aead_req);
 234
 235         ctx->sg_encrypted_data[0].offset -= tls_ctx->prepend_size;
 236         ctx->sg_encrypted_data[0].length += tls_ctx->prepend_size;
 237
 238         kfree(aead_req);
 239         return rc;
 240 }
 241
 242 static int tls_push_record(struct sock *sk, int flags,
 243                            unsigned char record_type)
 244 {
 245         struct tls_context *tls_ctx = tls_get_ctx(sk);
 246         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
 247         int rc;
 248
 249         sg_mark_end(ctx->sg_plaintext_data + ctx->sg_plaintext_num_elem - 1);
 250         sg_mark_end(ctx->sg_encrypted_data + ctx->sg_encrypted_num_elem - 1);
 251
 252         tls_make_aad(0, ctx->aad_space, ctx->sg_plaintext_size,
 253                      tls_ctx->rec_seq, tls_ctx->rec_seq_size,
 254                      record_type);
 255
 256         tls_fill_prepend(tls_ctx,
 257                          page_address(sg_page(&ctx->sg_encrypted_data[0])) +
 258                          ctx->sg_encrypted_data[0].offset,
 259                          ctx->sg_plaintext_size, record_type);
 260
 261         tls_ctx->pending_open_record_frags = 0;
 262         set_bit(TLS_PENDING_CLOSED_RECORD, &tls_ctx->flags);
 263
 264         rc = tls_do_encryption(tls_ctx, ctx, ctx->sg_plaintext_size,
 265                                sk->sk_allocation);
 266         if (rc < 0) {
 267                 /* If we are called from write_space and
 268                  * we fail, we need to set this SOCK_NOSPACE
 269                  * to trigger another write_space in the future.
 270                  */
 271                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
 272                 return rc;
 273         }
 274
 275         free_sg(sk, ctx->sg_plaintext_data, &ctx->sg_plaintext_num_elem,
 276                 &ctx->sg_plaintext_size);
 277
 278         ctx->sg_encrypted_num_elem = 0;
 279         ctx->sg_encrypted_size = 0;
 280
 281         /* Only pass through MSG_DONTWAIT and MSG_NOSIGNAL flags */
 282         rc = tls_push_sg(sk, tls_ctx, ctx->sg_encrypted_data, 0, flags);
 283         if (rc < 0 && rc != -EAGAIN)
 284                 tls_err_abort(sk);
 285
 286         tls_advance_record_sn(sk, tls_ctx);
 287         return rc;
 288 }
 289
 290 static int tls_sw_push_pending_record(struct sock *sk, int flags)
 291 {
 292         return tls_push_record(sk, flags, TLS_RECORD_TYPE_DATA);
 293 }
 294
 295 static int zerocopy_from_iter(struct sock *sk, struct iov_iter *from,
 296                               int length)
 297 {
 298         struct tls_context *tls_ctx = tls_get_ctx(sk);
 299         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
 300         struct page *pages[MAX_SKB_FRAGS];
 301
 302         size_t offset;
 303         ssize_t copied, use;
 304         int i = 0;
 305         unsigned int size = ctx->sg_plaintext_size;
 306         int num_elem = ctx->sg_plaintext_num_elem;
 307         int rc = 0;
 308         int maxpages;
 309
 310         while (length > 0) {
 311                 i = 0;
 312                 maxpages = ARRAY_SIZE(ctx->sg_plaintext_data) - num_elem;
 313                 if (maxpages == 0) {
 314                         rc = -EFAULT;
 315                         goto out;
 316                 }
 317                 copied = iov_iter_get_pages(from, pages,
 318                                             length,
 319                                             maxpages, &offset);
 320                 if (copied <= 0) {
 321                         rc = -EFAULT;
 322                         goto out;
 323                 }
 324
 325                 iov_iter_advance(from, copied);
 326
 327                 length -= copied;
 328                 size += copied;
 329                 while (copied) {
 330                         use = min_t(int, copied, PAGE_SIZE - offset);
 331
 332                         sg_set_page(&ctx->sg_plaintext_data[num_elem],
 333                                     pages[i], use, offset);
 334                         sg_unmark_end(&ctx->sg_plaintext_data[num_elem]);
 335                         sk_mem_charge(sk, use);
 336
 337                         offset = 0;
 338                         copied -= use;
 339
 340                         ++i;
 341                         ++num_elem;
 342                 }
 343         }
 344
 345 out:
 346         ctx->sg_plaintext_size = size;
 347         ctx->sg_plaintext_num_elem = num_elem;
 348         return rc;
 349 }
 350
 351 static int memcopy_from_iter(struct sock *sk, struct iov_iter *from,
 352                              int bytes)
 353 {
 354         struct tls_context *tls_ctx = tls_get_ctx(sk);
 355         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
 356         struct scatterlist *sg = ctx->sg_plaintext_data;
 357         int copy, i, rc = 0;
 358
 359         for (i = tls_ctx->pending_open_record_frags;
 360              i < ctx->sg_plaintext_num_elem; ++i) {
 361                 copy = sg[i].length;
 362                 if (copy_from_iter(
 363                                 page_address(sg_page(&sg[i])) + sg[i].offset,
 364                                 copy, from) != copy) {
 365                         rc = -EFAULT;
 366                         goto out;
 367                 }
 368                 bytes -= copy;
 369
 370                 ++tls_ctx->pending_open_record_frags;
 371
 372                 if (!bytes)
 373                         break;
 374         }
 375
 376 out:
 377         return rc;
 378 }
 379
 380 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
 381 {
 382         struct tls_context *tls_ctx = tls_get_ctx(sk);
 383         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
 384         int ret = 0;
 385         int required_size;
 386         long timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
 387         bool eor = !(msg->msg_flags & MSG_MORE);
 388         size_t try_to_copy, copied = 0;
 389         unsigned char record_type = TLS_RECORD_TYPE_DATA;
 390         int record_room;
 391         bool full_record;
 392         int orig_size;
 393
 394         if (msg->msg_flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL))
 395                 return -ENOTSUPP;
 396
 397         lock_sock(sk);
 398
 399         if (tls_complete_pending_work(sk, tls_ctx, msg->msg_flags, &timeo))
 400                 goto send_end;
 401
 402         if (unlikely(msg->msg_controllen)) {
 403                 ret = tls_proccess_cmsg(sk, msg, &record_type);
 404                 if (ret)
 405                         goto send_end;
 406         }
 407
 408         while (msg_data_left(msg)) {
 409                 if (sk->sk_err) {
 410                         ret = sk->sk_err;
 411                         goto send_end;
 412                 }
 413
 414                 orig_size = ctx->sg_plaintext_size;
 415                 full_record = false;
 416                 try_to_copy = msg_data_left(msg);
 417                 record_room = TLS_MAX_PAYLOAD_SIZE - ctx->sg_plaintext_size;
 418                 if (try_to_copy >= record_room) {
 419                         try_to_copy = record_room;
 420                         full_record = true;
 421                 }
 422
 423                 required_size = ctx->sg_plaintext_size + try_to_copy +
 424                                 tls_ctx->overhead_size;
 425
 426                 if (!sk_stream_memory_free(sk))
 427                         goto wait_for_sndbuf;
 428 alloc_encrypted:
 429                 ret = alloc_encrypted_sg(sk, required_size);
 430                 if (ret) {
 431                         if (ret != -ENOSPC)
 432                                 goto wait_for_memory;
 433
 434                         /* Adjust try_to_copy according to the amount that was
 435                          * actually allocated. The difference is due
 436                          * to max sg elements limit
 437                          */
 438                         try_to_copy -= required_size - ctx->sg_encrypted_size;
 439                         full_record = true;
 440                 }
 441
 442                 if (full_record || eor) {
 443                         ret = zerocopy_from_iter(sk, &msg->msg_iter,
 444                                                  try_to_copy);
 445                         if (ret)
 446                                 goto fallback_to_reg_send;
 447
 448                         copied += try_to_copy;
 449                         ret = tls_push_record(sk, msg->msg_flags, record_type);
 450                         if (!ret)
 451                                 continue;
 452                         if (ret == -EAGAIN)
 453                                 goto send_end;
 454
 455                         copied -= try_to_copy;
 456 fallback_to_reg_send:
 457                         iov_iter_revert(&msg->msg_iter,
 458                                         ctx->sg_plaintext_size - orig_size);
 459                         trim_sg(sk, ctx->sg_plaintext_data,
 460                                 &ctx->sg_plaintext_num_elem,
 461                                 &ctx->sg_plaintext_size,
 462                                 orig_size);
 463                 }
 464
 465                 required_size = ctx->sg_plaintext_size + try_to_copy;
 466 alloc_plaintext:
 467                 ret = alloc_plaintext_sg(sk, required_size);
 468                 if (ret) {
 469                         if (ret != -ENOSPC)
 470                                 goto wait_for_memory;
 471
 472                         /* Adjust try_to_copy according to the amount that was
 473                          * actually allocated. The difference is due
 474                          * to max sg elements limit
 475                          */
 476                         try_to_copy -= required_size - ctx->sg_plaintext_size;
 477                         full_record = true;
 478
 479                         trim_sg(sk, ctx->sg_encrypted_data,
 480                                 &ctx->sg_encrypted_num_elem,
 481                                 &ctx->sg_encrypted_size,
 482                                 ctx->sg_plaintext_size +
 483                                 tls_ctx->overhead_size);
 484                 }
 485
 486                 ret = memcopy_from_iter(sk, &msg->msg_iter, try_to_copy);
 487                 if (ret)
 488                         goto trim_sgl;
 489
 490                 copied += try_to_copy;
 491                 if (full_record || eor) {
 492 push_record:
 493                         ret = tls_push_record(sk, msg->msg_flags, record_type);
 494                         if (ret) {
 495                                 if (ret == -ENOMEM)
 496                                         goto wait_for_memory;
 497
 498                                 goto send_end;
 499                         }
 500                 }
 501
 502                 continue;
 503
 504 wait_for_sndbuf:
 505                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
 506 wait_for_memory:
 507                 ret = sk_stream_wait_memory(sk, &timeo);
 508                 if (ret) {
 509 trim_sgl:
 510                         trim_both_sgl(sk, orig_size);
 511                         goto send_end;
 512                 }
 513
 514                 if (tls_is_pending_closed_record(tls_ctx))
 515                         goto push_record;
 516
 517                 if (ctx->sg_encrypted_size < required_size)
 518                         goto alloc_encrypted;
 519
 520                 goto alloc_plaintext;
 521         }
 522
 523 send_end:
 524         ret = sk_stream_error(sk, msg->msg_flags, ret);
 525
 526         release_sock(sk);
 527         return copied ? copied : ret;
 528 }
 529
 530 int tls_sw_sendpage(struct sock *sk, struct page *page,
 531                     int offset, size_t size, int flags)
 532 {
 533         struct tls_context *tls_ctx = tls_get_ctx(sk);
 534         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
 535         int ret = 0;
 536         long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
 537         bool eor;
 538         size_t orig_size = size;
 539         unsigned char record_type = TLS_RECORD_TYPE_DATA;
 540         struct scatterlist *sg;
 541         bool full_record;
 542         int record_room;
 543
 544         if (flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL |
 545                       MSG_SENDPAGE_NOTLAST))
 546                 return -ENOTSUPP;
 547
 548         /* No MSG_EOR from splice, only look at MSG_MORE */
 549         eor = !(flags & (MSG_MORE | MSG_SENDPAGE_NOTLAST));
 550
 551         lock_sock(sk);
 552
 553         sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 554
 555         if (tls_complete_pending_work(sk, tls_ctx, flags, &timeo))
 556                 goto sendpage_end;
 557
 558         /* Call the sk_stream functions to manage the sndbuf mem. */
 559         while (size > 0) {
 560                 size_t copy, required_size;
 561
 562                 if (sk->sk_err) {
 563                         ret = sk->sk_err;
 564                         goto sendpage_end;
 565                 }
 566
 567                 full_record = false;
 568                 record_room = TLS_MAX_PAYLOAD_SIZE - ctx->sg_plaintext_size;
 569                 copy = size;
 570                 if (copy >= record_room) {
 571                         copy = record_room;
 572                         full_record = true;
 573                 }
 574                 required_size = ctx->sg_plaintext_size + copy +
 575                               tls_ctx->overhead_size;
 576
 577                 if (!sk_stream_memory_free(sk))
 578                         goto wait_for_sndbuf;
 579 alloc_payload:
 580                 ret = alloc_encrypted_sg(sk, required_size);
 581                 if (ret) {
 582                         if (ret != -ENOSPC)
 583                                 goto wait_for_memory;
 584
 585                         /* Adjust copy according to the amount that was
 586                          * actually allocated. The difference is due
 587                          * to max sg elements limit
 588                          */
 589                         copy -= required_size - ctx->sg_plaintext_size;
 590                         full_record = true;
 591                 }
 592
 593                 get_page(page);
 594                 sg = ctx->sg_plaintext_data + ctx->sg_plaintext_num_elem;
 595                 sg_set_page(sg, page, copy, offset);
 596                 ctx->sg_plaintext_num_elem++;
 597
 598                 sk_mem_charge(sk, copy);
 599                 offset += copy;
 600                 size -= copy;
 601                 ctx->sg_plaintext_size += copy;
 602                 tls_ctx->pending_open_record_frags = ctx->sg_plaintext_num_elem;
 603
 604                 if (full_record || eor ||
 605                     ctx->sg_plaintext_num_elem ==
 606                     ARRAY_SIZE(ctx->sg_plaintext_data)) {
 607 push_record:
 608                         ret = tls_push_record(sk, flags, record_type);
 609                         if (ret) {
 610                                 if (ret == -ENOMEM)
 611                                         goto wait_for_memory;
 612
 613                                 goto sendpage_end;
 614                         }
 615                 }
 616                 continue;
 617 wait_for_sndbuf:
 618                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
 619 wait_for_memory:
 620                 ret = sk_stream_wait_memory(sk, &timeo);
 621                 if (ret) {
 622                         trim_both_sgl(sk, ctx->sg_plaintext_size);
 623                         goto sendpage_end;
 624                 }
 625
 626                 if (tls_is_pending_closed_record(tls_ctx))
 627                         goto push_record;
 628
 629                 goto alloc_payload;
 630         }
 631
 632 sendpage_end:
 633         if (orig_size > size)
 634                 ret = orig_size - size;
 635         else
 636                 ret = sk_stream_error(sk, flags, ret);
 637
 638         release_sock(sk);
 639         return ret;
 640 }
 641
 642 static void tls_sw_free_resources(struct sock *sk)
 643 {
 644         struct tls_context *tls_ctx = tls_get_ctx(sk);
 645         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
 646
 647         if (ctx->aead_send)
 648                 crypto_free_aead(ctx->aead_send);
 649
 650         tls_free_both_sg(sk);
 651
 652         kfree(ctx);
 653 }
 654
 655 int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx)
 656 {
 657         char keyval[TLS_CIPHER_AES_GCM_128_KEY_SIZE];
 658         struct tls_crypto_info *crypto_info;
 659         struct tls12_crypto_info_aes_gcm_128 *gcm_128_info;
 660         struct tls_sw_context *sw_ctx;
 661         u16 nonce_size, tag_size, iv_size, rec_seq_size;
 662         char *iv, *rec_seq;
 663         int rc = 0;
 664
 665         if (!ctx) {
 666                 rc = -EINVAL;
 667                 goto out;
 668         }
 669
 670         if (ctx->priv_ctx) {
 671                 rc = -EEXIST;
 672                 goto out;
 673         }
 674
 675         sw_ctx = kzalloc(sizeof(*sw_ctx), GFP_KERNEL);
 676         if (!sw_ctx) {
 677                 rc = -ENOMEM;
 678                 goto out;
 679         }
 680
 681         ctx->priv_ctx = (struct tls_offload_context *)sw_ctx;
 682         ctx->free_resources = tls_sw_free_resources;
 683
 684         crypto_info = &ctx->crypto_send;
 685         switch (crypto_info->cipher_type) {
 686         case TLS_CIPHER_AES_GCM_128: {
 687                 nonce_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
 688                 tag_size = TLS_CIPHER_AES_GCM_128_TAG_SIZE;
 689                 iv_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
 690                 iv = ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->iv;
 691                 rec_seq_size = TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE;
 692                 rec_seq =
 693                  ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->rec_seq;
 694                 gcm_128_info =
 695                         (struct tls12_crypto_info_aes_gcm_128 *)crypto_info;
 696                 break;
 697         }
 698         default:
 699                 rc = -EINVAL;
 700                 goto out;
 701         }
 702
 703         ctx->prepend_size = TLS_HEADER_SIZE + nonce_size;
 704         ctx->tag_size = tag_size;
 705         ctx->overhead_size = ctx->prepend_size + ctx->tag_size;
 706         ctx->iv_size = iv_size;
 707         ctx->iv = kmalloc(iv_size + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
 708                           GFP_KERNEL);
 709         if (!ctx->iv) {
 710                 rc = -ENOMEM;
 711                 goto out;
 712         }
 713         memcpy(ctx->iv, gcm_128_info->salt, TLS_CIPHER_AES_GCM_128_SALT_SIZE);
 714         memcpy(ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv, iv_size);
 715         ctx->rec_seq_size = rec_seq_size;
 716         ctx->rec_seq = kmalloc(rec_seq_size, GFP_KERNEL);
 717         if (!ctx->rec_seq) {
 718                 rc = -ENOMEM;
 719                 goto free_iv;
 720         }
 721         memcpy(ctx->rec_seq, rec_seq, rec_seq_size);
 722
 723         sg_init_table(sw_ctx->sg_encrypted_data,
 724                       ARRAY_SIZE(sw_ctx->sg_encrypted_data));
 725         sg_init_table(sw_ctx->sg_plaintext_data,
 726                       ARRAY_SIZE(sw_ctx->sg_plaintext_data));
 727
 728         sg_init_table(sw_ctx->sg_aead_in, 2);
 729         sg_set_buf(&sw_ctx->sg_aead_in[0], sw_ctx->aad_space,
 730                    sizeof(sw_ctx->aad_space));
 731         sg_unmark_end(&sw_ctx->sg_aead_in[1]);
 732         sg_chain(sw_ctx->sg_aead_in, 2, sw_ctx->sg_plaintext_data);
 733         sg_init_table(sw_ctx->sg_aead_out, 2);
 734         sg_set_buf(&sw_ctx->sg_aead_out[0], sw_ctx->aad_space,
 735                    sizeof(sw_ctx->aad_space));
 736         sg_unmark_end(&sw_ctx->sg_aead_out[1]);
 737         sg_chain(sw_ctx->sg_aead_out, 2, sw_ctx->sg_encrypted_data);
 738
 739         if (!sw_ctx->aead_send) {
 740                 sw_ctx->aead_send = crypto_alloc_aead("gcm(aes)", 0, 0);
 741                 if (IS_ERR(sw_ctx->aead_send)) {
 742                         rc = PTR_ERR(sw_ctx->aead_send);
 743                         sw_ctx->aead_send = NULL;
 744                         goto free_rec_seq;
 745                 }
 746         }
 747
 748         ctx->push_pending_record = tls_sw_push_pending_record;
 749
 750         memcpy(keyval, gcm_128_info->key, TLS_CIPHER_AES_GCM_128_KEY_SIZE);
 751
 752         rc = crypto_aead_setkey(sw_ctx->aead_send, keyval,
 753                                 TLS_CIPHER_AES_GCM_128_KEY_SIZE);
 754         if (rc)
 755                 goto free_aead;
 756
 757         rc = crypto_aead_setauthsize(sw_ctx->aead_send, ctx->tag_size);
 758         if (!rc)
 759                 goto out;
 760
 761 free_aead:
 762         crypto_free_aead(sw_ctx->aead_send);
 763         sw_ctx->aead_send = NULL;
 764 free_rec_seq:
 765         kfree(ctx->rec_seq);
 766         ctx->rec_seq = NULL;
 767 free_iv:
 768         kfree(ctx->iv);
 769         ctx->iv = NULL;
 770 out:
 771         return rc;
 772 }