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