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/sched/signal.h>
  38 #include <linux/module.h>
  39 #include <crypto/aead.h>
  40
  41 #include <net/strparser.h>
  42 #include <net/tls.h>
  43
  44 #define MAX_IV_SIZE     TLS_CIPHER_AES_GCM_128_IV_SIZE
  45
  46 static int tls_do_decryption(struct sock *sk,
  47                              struct scatterlist *sgin,
  48                              struct scatterlist *sgout,
  49                              char *iv_recv,
  50                              size_t data_len,
  51                              struct sk_buff *skb,
  52                              gfp_t flags)
  53 {
  54         struct tls_context *tls_ctx = tls_get_ctx(sk);
  55         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
  56         struct strp_msg *rxm = strp_msg(skb);
  57         struct aead_request *aead_req;
  58
  59         int ret;
  60         unsigned int req_size = sizeof(struct aead_request) +
  61                 crypto_aead_reqsize(ctx->aead_recv);
  62
  63         aead_req = kzalloc(req_size, flags);
  64         if (!aead_req)
  65                 return -ENOMEM;
  66
  67         aead_request_set_tfm(aead_req, ctx->aead_recv);
  68         aead_request_set_ad(aead_req, TLS_AAD_SPACE_SIZE);
  69         aead_request_set_crypt(aead_req, sgin, sgout,
  70                                data_len + tls_ctx->rx.tag_size,
  71                                (u8 *)iv_recv);
  72         aead_request_set_callback(aead_req, CRYPTO_TFM_REQ_MAY_BACKLOG,
  73                                   crypto_req_done, &ctx->async_wait);
  74
  75         ret = crypto_wait_req(crypto_aead_decrypt(aead_req), &ctx->async_wait);
  76
  77         if (ret < 0)
  78                 goto out;
  79
  80         rxm->offset += tls_ctx->rx.prepend_size;
  81         rxm->full_len -= tls_ctx->rx.overhead_size;
  82         tls_advance_record_sn(sk, &tls_ctx->rx);
  83
  84         ctx->decrypted = true;
  85
  86         ctx->saved_data_ready(sk);
  87
  88 out:
  89         kfree(aead_req);
  90         return ret;
  91 }
  92
  93 static void trim_sg(struct sock *sk, struct scatterlist *sg,
  94                     int *sg_num_elem, unsigned int *sg_size, int target_size)
  95 {
  96         int i = *sg_num_elem - 1;
  97         int trim = *sg_size - target_size;
  98
  99         if (trim <= 0) {
 100                 WARN_ON(trim < 0);
 101                 return;
 102         }
 103
 104         *sg_size = target_size;
 105         while (trim >= sg[i].length) {
 106                 trim -= sg[i].length;
 107                 sk_mem_uncharge(sk, sg[i].length);
 108                 put_page(sg_page(&sg[i]));
 109                 i--;
 110
 111                 if (i < 0)
 112                         goto out;
 113         }
 114
 115         sg[i].length -= trim;
 116         sk_mem_uncharge(sk, trim);
 117
 118 out:
 119         *sg_num_elem = i + 1;
 120 }
 121
 122 static void trim_both_sgl(struct sock *sk, int target_size)
 123 {
 124         struct tls_context *tls_ctx = tls_get_ctx(sk);
 125         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
 126
 127         trim_sg(sk, ctx->sg_plaintext_data,
 128                 &ctx->sg_plaintext_num_elem,
 129                 &ctx->sg_plaintext_size,
 130                 target_size);
 131
 132         if (target_size > 0)
 133                 target_size += tls_ctx->tx.overhead_size;
 134
 135         trim_sg(sk, ctx->sg_encrypted_data,
 136                 &ctx->sg_encrypted_num_elem,
 137                 &ctx->sg_encrypted_size,
 138                 target_size);
 139 }
 140
 141 static int alloc_encrypted_sg(struct sock *sk, int len)
 142 {
 143         struct tls_context *tls_ctx = tls_get_ctx(sk);
 144         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
 145         int rc = 0;
 146
 147         rc = sk_alloc_sg(sk, len,
 148                          ctx->sg_encrypted_data, 0,
 149                          &ctx->sg_encrypted_num_elem,
 150                          &ctx->sg_encrypted_size, 0);
 151
 152         return rc;
 153 }
 154
 155 static int alloc_plaintext_sg(struct sock *sk, int len)
 156 {
 157         struct tls_context *tls_ctx = tls_get_ctx(sk);
 158         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
 159         int rc = 0;
 160
 161         rc = sk_alloc_sg(sk, len, ctx->sg_plaintext_data, 0,
 162                          &ctx->sg_plaintext_num_elem, &ctx->sg_plaintext_size,
 163                          tls_ctx->pending_open_record_frags);
 164
 165         return rc;
 166 }
 167
 168 static void free_sg(struct sock *sk, struct scatterlist *sg,
 169                     int *sg_num_elem, unsigned int *sg_size)
 170 {
 171         int i, n = *sg_num_elem;
 172
 173         for (i = 0; i < n; ++i) {
 174                 sk_mem_uncharge(sk, sg[i].length);
 175                 put_page(sg_page(&sg[i]));
 176         }
 177         *sg_num_elem = 0;
 178         *sg_size = 0;
 179 }
 180
 181 static void tls_free_both_sg(struct sock *sk)
 182 {
 183         struct tls_context *tls_ctx = tls_get_ctx(sk);
 184         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
 185
 186         free_sg(sk, ctx->sg_encrypted_data, &ctx->sg_encrypted_num_elem,
 187                 &ctx->sg_encrypted_size);
 188
 189         free_sg(sk, ctx->sg_plaintext_data, &ctx->sg_plaintext_num_elem,
 190                 &ctx->sg_plaintext_size);
 191 }
 192
 193 static int tls_do_encryption(struct tls_context *tls_ctx,
 194                              struct tls_sw_context *ctx, size_t data_len,
 195                              gfp_t flags)
 196 {
 197         unsigned int req_size = sizeof(struct aead_request) +
 198                 crypto_aead_reqsize(ctx->aead_send);
 199         struct aead_request *aead_req;
 200         int rc;
 201
 202         aead_req = kzalloc(req_size, flags);
 203         if (!aead_req)
 204                 return -ENOMEM;
 205
 206         ctx->sg_encrypted_data[0].offset += tls_ctx->tx.prepend_size;
 207         ctx->sg_encrypted_data[0].length -= tls_ctx->tx.prepend_size;
 208
 209         aead_request_set_tfm(aead_req, ctx->aead_send);
 210         aead_request_set_ad(aead_req, TLS_AAD_SPACE_SIZE);
 211         aead_request_set_crypt(aead_req, ctx->sg_aead_in, ctx->sg_aead_out,
 212                                data_len, tls_ctx->tx.iv);
 213
 214         aead_request_set_callback(aead_req, CRYPTO_TFM_REQ_MAY_BACKLOG,
 215                                   crypto_req_done, &ctx->async_wait);
 216
 217         rc = crypto_wait_req(crypto_aead_encrypt(aead_req), &ctx->async_wait);
 218
 219         ctx->sg_encrypted_data[0].offset -= tls_ctx->tx.prepend_size;
 220         ctx->sg_encrypted_data[0].length += tls_ctx->tx.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->tx.rec_seq, tls_ctx->tx.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, EBADMSG);
 269
 270         tls_advance_record_sn(sk, &tls_ctx->tx);
 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, int *pages_used,
 281                               unsigned int *size_used,
 282                               struct scatterlist *to, int to_max_pages,
 283                               bool charge)
 284 {
 285         struct page *pages[MAX_SKB_FRAGS];
 286
 287         size_t offset;
 288         ssize_t copied, use;
 289         int i = 0;
 290         unsigned int size = *size_used;
 291         int num_elem = *pages_used;
 292         int rc = 0;
 293         int maxpages;
 294
 295         while (length > 0) {
 296                 i = 0;
 297                 maxpages = to_max_pages - num_elem;
 298                 if (maxpages == 0) {
 299                         rc = -EFAULT;
 300                         goto out;
 301                 }
 302                 copied = iov_iter_get_pages(from, pages,
 303                                             length,
 304                                             maxpages, &offset);
 305                 if (copied <= 0) {
 306                         rc = -EFAULT;
 307                         goto out;
 308                 }
 309
 310                 iov_iter_advance(from, copied);
 311
 312                 length -= copied;
 313                 size += copied;
 314                 while (copied) {
 315                         use = min_t(int, copied, PAGE_SIZE - offset);
 316
 317                         sg_set_page(&to[num_elem],
 318                                     pages[i], use, offset);
 319                         sg_unmark_end(&to[num_elem]);
 320                         if (charge)
 321                                 sk_mem_charge(sk, use);
 322
 323                         offset = 0;
 324                         copied -= use;
 325
 326                         ++i;
 327                         ++num_elem;
 328                 }
 329         }
 330
 331 out:
 332         *size_used = size;
 333         *pages_used = num_elem;
 334
 335         return rc;
 336 }
 337
 338 static int memcopy_from_iter(struct sock *sk, struct iov_iter *from,
 339                              int bytes)
 340 {
 341         struct tls_context *tls_ctx = tls_get_ctx(sk);
 342         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
 343         struct scatterlist *sg = ctx->sg_plaintext_data;
 344         int copy, i, rc = 0;
 345
 346         for (i = tls_ctx->pending_open_record_frags;
 347              i < ctx->sg_plaintext_num_elem; ++i) {
 348                 copy = sg[i].length;
 349                 if (copy_from_iter(
 350                                 page_address(sg_page(&sg[i])) + sg[i].offset,
 351                                 copy, from) != copy) {
 352                         rc = -EFAULT;
 353                         goto out;
 354                 }
 355                 bytes -= copy;
 356
 357                 ++tls_ctx->pending_open_record_frags;
 358
 359                 if (!bytes)
 360                         break;
 361         }
 362
 363 out:
 364         return rc;
 365 }
 366
 367 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
 368 {
 369         struct tls_context *tls_ctx = tls_get_ctx(sk);
 370         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
 371         int ret = 0;
 372         int required_size;
 373         long timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
 374         bool eor = !(msg->msg_flags & MSG_MORE);
 375         size_t try_to_copy, copied = 0;
 376         unsigned char record_type = TLS_RECORD_TYPE_DATA;
 377         int record_room;
 378         bool full_record;
 379         int orig_size;
 380
 381         if (msg->msg_flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL))
 382                 return -ENOTSUPP;
 383
 384         lock_sock(sk);
 385
 386         if (tls_complete_pending_work(sk, tls_ctx, msg->msg_flags, &timeo))
 387                 goto send_end;
 388
 389         if (unlikely(msg->msg_controllen)) {
 390                 ret = tls_proccess_cmsg(sk, msg, &record_type);
 391                 if (ret)
 392                         goto send_end;
 393         }
 394
 395         while (msg_data_left(msg)) {
 396                 if (sk->sk_err) {
 397                         ret = -sk->sk_err;
 398                         goto send_end;
 399                 }
 400
 401                 orig_size = ctx->sg_plaintext_size;
 402                 full_record = false;
 403                 try_to_copy = msg_data_left(msg);
 404                 record_room = TLS_MAX_PAYLOAD_SIZE - ctx->sg_plaintext_size;
 405                 if (try_to_copy >= record_room) {
 406                         try_to_copy = record_room;
 407                         full_record = true;
 408                 }
 409
 410                 required_size = ctx->sg_plaintext_size + try_to_copy +
 411                                 tls_ctx->tx.overhead_size;
 412
 413                 if (!sk_stream_memory_free(sk))
 414                         goto wait_for_sndbuf;
 415 alloc_encrypted:
 416                 ret = alloc_encrypted_sg(sk, required_size);
 417                 if (ret) {
 418                         if (ret != -ENOSPC)
 419                                 goto wait_for_memory;
 420
 421                         /* Adjust try_to_copy according to the amount that was
 422                          * actually allocated. The difference is due
 423                          * to max sg elements limit
 424                          */
 425                         try_to_copy -= required_size - ctx->sg_encrypted_size;
 426                         full_record = true;
 427                 }
 428
 429                 if (full_record || eor) {
 430                         ret = zerocopy_from_iter(sk, &msg->msg_iter,
 431                                 try_to_copy, &ctx->sg_plaintext_num_elem,
 432                                 &ctx->sg_plaintext_size,
 433                                 ctx->sg_plaintext_data,
 434                                 ARRAY_SIZE(ctx->sg_plaintext_data),
 435                                 true);
 436                         if (ret)
 437                                 goto fallback_to_reg_send;
 438
 439                         copied += try_to_copy;
 440                         ret = tls_push_record(sk, msg->msg_flags, record_type);
 441                         if (!ret)
 442                                 continue;
 443                         if (ret == -EAGAIN)
 444                                 goto send_end;
 445
 446                         copied -= try_to_copy;
 447 fallback_to_reg_send:
 448                         iov_iter_revert(&msg->msg_iter,
 449                                         ctx->sg_plaintext_size - orig_size);
 450                         trim_sg(sk, ctx->sg_plaintext_data,
 451                                 &ctx->sg_plaintext_num_elem,
 452                                 &ctx->sg_plaintext_size,
 453                                 orig_size);
 454                 }
 455
 456                 required_size = ctx->sg_plaintext_size + try_to_copy;
 457 alloc_plaintext:
 458                 ret = alloc_plaintext_sg(sk, required_size);
 459                 if (ret) {
 460                         if (ret != -ENOSPC)
 461                                 goto wait_for_memory;
 462
 463                         /* Adjust try_to_copy according to the amount that was
 464                          * actually allocated. The difference is due
 465                          * to max sg elements limit
 466                          */
 467                         try_to_copy -= required_size - ctx->sg_plaintext_size;
 468                         full_record = true;
 469
 470                         trim_sg(sk, ctx->sg_encrypted_data,
 471                                 &ctx->sg_encrypted_num_elem,
 472                                 &ctx->sg_encrypted_size,
 473                                 ctx->sg_plaintext_size +
 474                                 tls_ctx->tx.overhead_size);
 475                 }
 476
 477                 ret = memcopy_from_iter(sk, &msg->msg_iter, try_to_copy);
 478                 if (ret)
 479                         goto trim_sgl;
 480
 481                 copied += try_to_copy;
 482                 if (full_record || eor) {
 483 push_record:
 484                         ret = tls_push_record(sk, msg->msg_flags, record_type);
 485                         if (ret) {
 486                                 if (ret == -ENOMEM)
 487                                         goto wait_for_memory;
 488
 489                                 goto send_end;
 490                         }
 491                 }
 492
 493                 continue;
 494
 495 wait_for_sndbuf:
 496                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
 497 wait_for_memory:
 498                 ret = sk_stream_wait_memory(sk, &timeo);
 499                 if (ret) {
 500 trim_sgl:
 501                         trim_both_sgl(sk, orig_size);
 502                         goto send_end;
 503                 }
 504
 505                 if (tls_is_pending_closed_record(tls_ctx))
 506                         goto push_record;
 507
 508                 if (ctx->sg_encrypted_size < required_size)
 509                         goto alloc_encrypted;
 510
 511                 goto alloc_plaintext;
 512         }
 513
 514 send_end:
 515         ret = sk_stream_error(sk, msg->msg_flags, ret);
 516
 517         release_sock(sk);
 518         return copied ? copied : ret;
 519 }
 520
 521 int tls_sw_sendpage(struct sock *sk, struct page *page,
 522                     int offset, size_t size, int flags)
 523 {
 524         struct tls_context *tls_ctx = tls_get_ctx(sk);
 525         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
 526         int ret = 0;
 527         long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
 528         bool eor;
 529         size_t orig_size = size;
 530         unsigned char record_type = TLS_RECORD_TYPE_DATA;
 531         struct scatterlist *sg;
 532         bool full_record;
 533         int record_room;
 534
 535         if (flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL |
 536                       MSG_SENDPAGE_NOTLAST))
 537                 return -ENOTSUPP;
 538
 539         /* No MSG_EOR from splice, only look at MSG_MORE */
 540         eor = !(flags & (MSG_MORE | MSG_SENDPAGE_NOTLAST));
 541
 542         lock_sock(sk);
 543
 544         sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 545
 546         if (tls_complete_pending_work(sk, tls_ctx, flags, &timeo))
 547                 goto sendpage_end;
 548
 549         /* Call the sk_stream functions to manage the sndbuf mem. */
 550         while (size > 0) {
 551                 size_t copy, required_size;
 552
 553                 if (sk->sk_err) {
 554                         ret = -sk->sk_err;
 555                         goto sendpage_end;
 556                 }
 557
 558                 full_record = false;
 559                 record_room = TLS_MAX_PAYLOAD_SIZE - ctx->sg_plaintext_size;
 560                 copy = size;
 561                 if (copy >= record_room) {
 562                         copy = record_room;
 563                         full_record = true;
 564                 }
 565                 required_size = ctx->sg_plaintext_size + copy +
 566                               tls_ctx->tx.overhead_size;
 567
 568                 if (!sk_stream_memory_free(sk))
 569                         goto wait_for_sndbuf;
 570 alloc_payload:
 571                 ret = alloc_encrypted_sg(sk, required_size);
 572                 if (ret) {
 573                         if (ret != -ENOSPC)
 574                                 goto wait_for_memory;
 575
 576                         /* Adjust copy according to the amount that was
 577                          * actually allocated. The difference is due
 578                          * to max sg elements limit
 579                          */
 580                         copy -= required_size - ctx->sg_plaintext_size;
 581                         full_record = true;
 582                 }
 583
 584                 get_page(page);
 585                 sg = ctx->sg_plaintext_data + ctx->sg_plaintext_num_elem;
 586                 sg_set_page(sg, page, copy, offset);
 587                 sg_unmark_end(sg);
 588
 589                 ctx->sg_plaintext_num_elem++;
 590
 591                 sk_mem_charge(sk, copy);
 592                 offset += copy;
 593                 size -= copy;
 594                 ctx->sg_plaintext_size += copy;
 595                 tls_ctx->pending_open_record_frags = ctx->sg_plaintext_num_elem;
 596
 597                 if (full_record || eor ||
 598                     ctx->sg_plaintext_num_elem ==
 599                     ARRAY_SIZE(ctx->sg_plaintext_data)) {
 600 push_record:
 601                         ret = tls_push_record(sk, flags, record_type);
 602                         if (ret) {
 603                                 if (ret == -ENOMEM)
 604                                         goto wait_for_memory;
 605
 606                                 goto sendpage_end;
 607                         }
 608                 }
 609                 continue;
 610 wait_for_sndbuf:
 611                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
 612 wait_for_memory:
 613                 ret = sk_stream_wait_memory(sk, &timeo);
 614                 if (ret) {
 615                         trim_both_sgl(sk, ctx->sg_plaintext_size);
 616                         goto sendpage_end;
 617                 }
 618
 619                 if (tls_is_pending_closed_record(tls_ctx))
 620                         goto push_record;
 621
 622                 goto alloc_payload;
 623         }
 624
 625 sendpage_end:
 626         if (orig_size > size)
 627                 ret = orig_size - size;
 628         else
 629                 ret = sk_stream_error(sk, flags, ret);
 630
 631         release_sock(sk);
 632         return ret;
 633 }
 634
 635 static struct sk_buff *tls_wait_data(struct sock *sk, int flags,
 636                                      long timeo, int *err)
 637 {
 638         struct tls_context *tls_ctx = tls_get_ctx(sk);
 639         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
 640         struct sk_buff *skb;
 641         DEFINE_WAIT_FUNC(wait, woken_wake_function);
 642
 643         while (!(skb = ctx->recv_pkt)) {
 644                 if (sk->sk_err) {
 645                         *err = sock_error(sk);
 646                         return NULL;
 647                 }
 648
 649                 if (sock_flag(sk, SOCK_DONE))
 650                         return NULL;
 651
 652                 if ((flags & MSG_DONTWAIT) || !timeo) {
 653                         *err = -EAGAIN;
 654                         return NULL;
 655                 }
 656
 657                 add_wait_queue(sk_sleep(sk), &wait);
 658                 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
 659                 sk_wait_event(sk, &timeo, ctx->recv_pkt != skb, &wait);
 660                 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
 661                 remove_wait_queue(sk_sleep(sk), &wait);
 662
 663                 /* Handle signals */
 664                 if (signal_pending(current)) {
 665                         *err = sock_intr_errno(timeo);
 666                         return NULL;
 667                 }
 668         }
 669
 670         return skb;
 671 }
 672
 673 static int decrypt_skb(struct sock *sk, struct sk_buff *skb,
 674                        struct scatterlist *sgout)
 675 {
 676         struct tls_context *tls_ctx = tls_get_ctx(sk);
 677         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
 678         char iv[TLS_CIPHER_AES_GCM_128_SALT_SIZE + MAX_IV_SIZE];
 679         struct scatterlist sgin_arr[MAX_SKB_FRAGS + 2];
 680         struct scatterlist *sgin = &sgin_arr[0];
 681         struct strp_msg *rxm = strp_msg(skb);
 682         int ret, nsg = ARRAY_SIZE(sgin_arr);
 683         struct sk_buff *unused;
 684
 685         ret = skb_copy_bits(skb, rxm->offset + TLS_HEADER_SIZE,
 686                             iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
 687                             tls_ctx->rx.iv_size);
 688         if (ret < 0)
 689                 return ret;
 690
 691         memcpy(iv, tls_ctx->rx.iv, TLS_CIPHER_AES_GCM_128_SALT_SIZE);
 692         if (!sgout) {
 693                 nsg = skb_cow_data(skb, 0, &unused) + 1;
 694                 sgin = kmalloc_array(nsg, sizeof(*sgin), sk->sk_allocation);
 695                 if (!sgout)
 696                         sgout = sgin;
 697         }
 698
 699         sg_init_table(sgin, nsg);
 700         sg_set_buf(&sgin[0], ctx->rx_aad_ciphertext, TLS_AAD_SPACE_SIZE);
 701
 702         nsg = skb_to_sgvec(skb, &sgin[1],
 703                            rxm->offset + tls_ctx->rx.prepend_size,
 704                            rxm->full_len - tls_ctx->rx.prepend_size);
 705
 706         tls_make_aad(ctx->rx_aad_ciphertext,
 707                      rxm->full_len - tls_ctx->rx.overhead_size,
 708                      tls_ctx->rx.rec_seq,
 709                      tls_ctx->rx.rec_seq_size,
 710                      ctx->control);
 711
 712         ret = tls_do_decryption(sk, sgin, sgout, iv,
 713                                 rxm->full_len - tls_ctx->rx.overhead_size,
 714                                 skb, sk->sk_allocation);
 715
 716         if (sgin != &sgin_arr[0])
 717                 kfree(sgin);
 718
 719         return ret;
 720 }
 721
 722 static bool tls_sw_advance_skb(struct sock *sk, struct sk_buff *skb,
 723                                unsigned int len)
 724 {
 725         struct tls_context *tls_ctx = tls_get_ctx(sk);
 726         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
 727         struct strp_msg *rxm = strp_msg(skb);
 728
 729         if (len < rxm->full_len) {
 730                 rxm->offset += len;
 731                 rxm->full_len -= len;
 732
 733                 return false;
 734         }
 735
 736         /* Finished with message */
 737         ctx->recv_pkt = NULL;
 738         kfree_skb(skb);
 739         strp_unpause(&ctx->strp);
 740
 741         return true;
 742 }
 743
 744 int tls_sw_recvmsg(struct sock *sk,
 745                    struct msghdr *msg,
 746                    size_t len,
 747                    int nonblock,
 748                    int flags,
 749                    int *addr_len)
 750 {
 751         struct tls_context *tls_ctx = tls_get_ctx(sk);
 752         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
 753         unsigned char control;
 754         struct strp_msg *rxm;
 755         struct sk_buff *skb;
 756         ssize_t copied = 0;
 757         bool cmsg = false;
 758         int err = 0;
 759         long timeo;
 760
 761         flags |= nonblock;
 762
 763         if (unlikely(flags & MSG_ERRQUEUE))
 764                 return sock_recv_errqueue(sk, msg, len, SOL_IP, IP_RECVERR);
 765
 766         lock_sock(sk);
 767
 768         timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
 769         do {
 770                 bool zc = false;
 771                 int chunk = 0;
 772
 773                 skb = tls_wait_data(sk, flags, timeo, &err);
 774                 if (!skb)
 775                         goto recv_end;
 776
 777                 rxm = strp_msg(skb);
 778                 if (!cmsg) {
 779                         int cerr;
 780
 781                         cerr = put_cmsg(msg, SOL_TLS, TLS_GET_RECORD_TYPE,
 782                                         sizeof(ctx->control), &ctx->control);
 783                         cmsg = true;
 784                         control = ctx->control;
 785                         if (ctx->control != TLS_RECORD_TYPE_DATA) {
 786                                 if (cerr || msg->msg_flags & MSG_CTRUNC) {
 787                                         err = -EIO;
 788                                         goto recv_end;
 789                                 }
 790                         }
 791                 } else if (control != ctx->control) {
 792                         goto recv_end;
 793                 }
 794
 795                 if (!ctx->decrypted) {
 796                         int page_count;
 797                         int to_copy;
 798
 799                         page_count = iov_iter_npages(&msg->msg_iter,
 800                                                      MAX_SKB_FRAGS);
 801                         to_copy = rxm->full_len - tls_ctx->rx.overhead_size;
 802                         if (to_copy <= len && page_count < MAX_SKB_FRAGS &&
 803                             likely(!(flags & MSG_PEEK)))  {
 804                                 struct scatterlist sgin[MAX_SKB_FRAGS + 1];
 805                                 int pages = 0;
 806
 807                                 zc = true;
 808                                 sg_init_table(sgin, MAX_SKB_FRAGS + 1);
 809                                 sg_set_buf(&sgin[0], ctx->rx_aad_plaintext,
 810                                            TLS_AAD_SPACE_SIZE);
 811
 812                                 err = zerocopy_from_iter(sk, &msg->msg_iter,
 813                                                          to_copy, &pages,
 814                                                          &chunk, &sgin[1],
 815                                                          MAX_SKB_FRAGS, false);
 816                                 if (err < 0)
 817                                         goto fallback_to_reg_recv;
 818
 819                                 err = decrypt_skb(sk, skb, sgin);
 820                                 for (; pages > 0; pages--)
 821                                         put_page(sg_page(&sgin[pages]));
 822                                 if (err < 0) {
 823                                         tls_err_abort(sk, EBADMSG);
 824                                         goto recv_end;
 825                                 }
 826                         } else {
 827 fallback_to_reg_recv:
 828                                 err = decrypt_skb(sk, skb, NULL);
 829                                 if (err < 0) {
 830                                         tls_err_abort(sk, EBADMSG);
 831                                         goto recv_end;
 832                                 }
 833                         }
 834                         ctx->decrypted = true;
 835                 }
 836
 837                 if (!zc) {
 838                         chunk = min_t(unsigned int, rxm->full_len, len);
 839                         err = skb_copy_datagram_msg(skb, rxm->offset, msg,
 840                                                     chunk);
 841                         if (err < 0)
 842                                 goto recv_end;
 843                 }
 844
 845                 copied += chunk;
 846                 len -= chunk;
 847                 if (likely(!(flags & MSG_PEEK))) {
 848                         u8 control = ctx->control;
 849
 850                         if (tls_sw_advance_skb(sk, skb, chunk)) {
 851                                 /* Return full control message to
 852                                  * userspace before trying to parse
 853                                  * another message type
 854                                  */
 855                                 msg->msg_flags |= MSG_EOR;
 856                                 if (control != TLS_RECORD_TYPE_DATA)
 857                                         goto recv_end;
 858                         }
 859                 }
 860         } while (len);
 861
 862 recv_end:
 863         release_sock(sk);
 864         return copied ? : err;
 865 }
 866
 867 ssize_t tls_sw_splice_read(struct socket *sock,  loff_t *ppos,
 868                            struct pipe_inode_info *pipe,
 869                            size_t len, unsigned int flags)
 870 {
 871         struct tls_context *tls_ctx = tls_get_ctx(sock->sk);
 872         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
 873         struct strp_msg *rxm = NULL;
 874         struct sock *sk = sock->sk;
 875         struct sk_buff *skb;
 876         ssize_t copied = 0;
 877         int err = 0;
 878         long timeo;
 879         int chunk;
 880
 881         lock_sock(sk);
 882
 883         timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
 884
 885         skb = tls_wait_data(sk, flags, timeo, &err);
 886         if (!skb)
 887                 goto splice_read_end;
 888
 889         /* splice does not support reading control messages */
 890         if (ctx->control != TLS_RECORD_TYPE_DATA) {
 891                 err = -ENOTSUPP;
 892                 goto splice_read_end;
 893         }
 894
 895         if (!ctx->decrypted) {
 896                 err = decrypt_skb(sk, skb, NULL);
 897
 898                 if (err < 0) {
 899                         tls_err_abort(sk, EBADMSG);
 900                         goto splice_read_end;
 901                 }
 902                 ctx->decrypted = true;
 903         }
 904         rxm = strp_msg(skb);
 905
 906         chunk = min_t(unsigned int, rxm->full_len, len);
 907         copied = skb_splice_bits(skb, sk, rxm->offset, pipe, chunk, flags);
 908         if (copied < 0)
 909                 goto splice_read_end;
 910
 911         if (likely(!(flags & MSG_PEEK)))
 912                 tls_sw_advance_skb(sk, skb, copied);
 913
 914 splice_read_end:
 915         release_sock(sk);
 916         return copied ? : err;
 917 }
 918
 919 unsigned int tls_sw_poll(struct file *file, struct socket *sock,
 920                          struct poll_table_struct *wait)
 921 {
 922         unsigned int ret;
 923         struct sock *sk = sock->sk;
 924         struct tls_context *tls_ctx = tls_get_ctx(sk);
 925         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
 926
 927         /* Grab POLLOUT and POLLHUP from the underlying socket */
 928         ret = ctx->sk_poll(file, sock, wait);
 929
 930         /* Clear POLLIN bits, and set based on recv_pkt */
 931         ret &= ~(POLLIN | POLLRDNORM);
 932         if (ctx->recv_pkt)
 933                 ret |= POLLIN | POLLRDNORM;
 934
 935         return ret;
 936 }
 937
 938 static int tls_read_size(struct strparser *strp, struct sk_buff *skb)
 939 {
 940         struct tls_context *tls_ctx = tls_get_ctx(strp->sk);
 941         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
 942         char header[tls_ctx->rx.prepend_size];
 943         struct strp_msg *rxm = strp_msg(skb);
 944         size_t cipher_overhead;
 945         size_t data_len = 0;
 946         int ret;
 947
 948         /* Verify that we have a full TLS header, or wait for more data */
 949         if (rxm->offset + tls_ctx->rx.prepend_size > skb->len)
 950                 return 0;
 951
 952         /* Linearize header to local buffer */
 953         ret = skb_copy_bits(skb, rxm->offset, header, tls_ctx->rx.prepend_size);
 954
 955         if (ret < 0)
 956                 goto read_failure;
 957
 958         ctx->control = header[0];
 959
 960         data_len = ((header[4] & 0xFF) | (header[3] << 8));
 961
 962         cipher_overhead = tls_ctx->rx.tag_size + tls_ctx->rx.iv_size;
 963
 964         if (data_len > TLS_MAX_PAYLOAD_SIZE + cipher_overhead) {
 965                 ret = -EMSGSIZE;
 966                 goto read_failure;
 967         }
 968         if (data_len < cipher_overhead) {
 969                 ret = -EBADMSG;
 970                 goto read_failure;
 971         }
 972
 973         if (header[1] != TLS_VERSION_MINOR(tls_ctx->crypto_recv.version) ||
 974             header[2] != TLS_VERSION_MAJOR(tls_ctx->crypto_recv.version)) {
 975                 ret = -EINVAL;
 976                 goto read_failure;
 977         }
 978
 979         return data_len + TLS_HEADER_SIZE;
 980
 981 read_failure:
 982         tls_err_abort(strp->sk, ret);
 983
 984         return ret;
 985 }
 986
 987 static void tls_queue(struct strparser *strp, struct sk_buff *skb)
 988 {
 989         struct tls_context *tls_ctx = tls_get_ctx(strp->sk);
 990         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
 991         struct strp_msg *rxm;
 992
 993         rxm = strp_msg(skb);
 994
 995         ctx->decrypted = false;
 996
 997         ctx->recv_pkt = skb;
 998         strp_pause(strp);
 999
1000         strp->sk->sk_state_change(strp->sk);
1001 }
1002
1003 static void tls_data_ready(struct sock *sk)
1004 {
1005         struct tls_context *tls_ctx = tls_get_ctx(sk);
1006         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
1007
1008         strp_data_ready(&ctx->strp);
1009 }
1010
1011 void tls_sw_free_resources(struct sock *sk)
1012 {
1013         struct tls_context *tls_ctx = tls_get_ctx(sk);
1014         struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
1015
1016         if (ctx->aead_send)
1017                 crypto_free_aead(ctx->aead_send);
1018         if (ctx->aead_recv) {
1019                 if (ctx->recv_pkt) {
1020                         kfree_skb(ctx->recv_pkt);
1021                         ctx->recv_pkt = NULL;
1022                 }
1023                 crypto_free_aead(ctx->aead_recv);
1024                 strp_stop(&ctx->strp);
1025                 write_lock_bh(&sk->sk_callback_lock);
1026                 sk->sk_data_ready = ctx->saved_data_ready;
1027                 write_unlock_bh(&sk->sk_callback_lock);
1028                 release_sock(sk);
1029                 strp_done(&ctx->strp);
1030                 lock_sock(sk);
1031         }
1032
1033         tls_free_both_sg(sk);
1034
1035         kfree(ctx);
1036         kfree(tls_ctx);
1037 }
1038
1039 int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx)
1040 {
1041         char keyval[TLS_CIPHER_AES_GCM_128_KEY_SIZE];
1042         struct tls_crypto_info *crypto_info;
1043         struct tls12_crypto_info_aes_gcm_128 *gcm_128_info;
1044         struct tls_sw_context *sw_ctx;
1045         struct cipher_context *cctx;
1046         struct crypto_aead **aead;
1047         struct strp_callbacks cb;
1048         u16 nonce_size, tag_size, iv_size, rec_seq_size;
1049         char *iv, *rec_seq;
1050         int rc = 0;
1051
1052         if (!ctx) {
1053                 rc = -EINVAL;
1054                 goto out;
1055         }
1056
1057         if (!ctx->priv_ctx) {
1058                 sw_ctx = kzalloc(sizeof(*sw_ctx), GFP_KERNEL);
1059                 if (!sw_ctx) {
1060                         rc = -ENOMEM;
1061                         goto out;
1062                 }
1063                 crypto_init_wait(&sw_ctx->async_wait);
1064         } else {
1065                 sw_ctx = ctx->priv_ctx;
1066         }
1067
1068         ctx->priv_ctx = (struct tls_offload_context *)sw_ctx;
1069
1070         if (tx) {
1071                 crypto_info = &ctx->crypto_send;
1072                 cctx = &ctx->tx;
1073                 aead = &sw_ctx->aead_send;
1074         } else {
1075                 crypto_info = &ctx->crypto_recv;
1076                 cctx = &ctx->rx;
1077                 aead = &sw_ctx->aead_recv;
1078         }
1079
1080         switch (crypto_info->cipher_type) {
1081         case TLS_CIPHER_AES_GCM_128: {
1082                 nonce_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
1083                 tag_size = TLS_CIPHER_AES_GCM_128_TAG_SIZE;
1084                 iv_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
1085                 iv = ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->iv;
1086                 rec_seq_size = TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE;
1087                 rec_seq =
1088                  ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->rec_seq;
1089                 gcm_128_info =
1090                         (struct tls12_crypto_info_aes_gcm_128 *)crypto_info;
1091                 break;
1092         }
1093         default:
1094                 rc = -EINVAL;
1095                 goto free_priv;
1096         }
1097
1098         /* Sanity-check the IV size for stack allocations. */
1099         if (iv_size > MAX_IV_SIZE) {
1100                 rc = -EINVAL;
1101                 goto free_priv;
1102         }
1103
1104         cctx->prepend_size = TLS_HEADER_SIZE + nonce_size;
1105         cctx->tag_size = tag_size;
1106         cctx->overhead_size = cctx->prepend_size + cctx->tag_size;
1107         cctx->iv_size = iv_size;
1108         cctx->iv = kmalloc(iv_size + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
1109                            GFP_KERNEL);
1110         if (!cctx->iv) {
1111                 rc = -ENOMEM;
1112                 goto free_priv;
1113         }
1114         memcpy(cctx->iv, gcm_128_info->salt, TLS_CIPHER_AES_GCM_128_SALT_SIZE);
1115         memcpy(cctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv, iv_size);
1116         cctx->rec_seq_size = rec_seq_size;
1117         cctx->rec_seq = kmalloc(rec_seq_size, GFP_KERNEL);
1118         if (!cctx->rec_seq) {
1119                 rc = -ENOMEM;
1120                 goto free_iv;
1121         }
1122         memcpy(cctx->rec_seq, rec_seq, rec_seq_size);
1123
1124         if (tx) {
1125                 sg_init_table(sw_ctx->sg_encrypted_data,
1126                               ARRAY_SIZE(sw_ctx->sg_encrypted_data));
1127                 sg_init_table(sw_ctx->sg_plaintext_data,
1128                               ARRAY_SIZE(sw_ctx->sg_plaintext_data));
1129
1130                 sg_init_table(sw_ctx->sg_aead_in, 2);
1131                 sg_set_buf(&sw_ctx->sg_aead_in[0], sw_ctx->aad_space,
1132                            sizeof(sw_ctx->aad_space));
1133                 sg_unmark_end(&sw_ctx->sg_aead_in[1]);
1134                 sg_chain(sw_ctx->sg_aead_in, 2, sw_ctx->sg_plaintext_data);
1135                 sg_init_table(sw_ctx->sg_aead_out, 2);
1136                 sg_set_buf(&sw_ctx->sg_aead_out[0], sw_ctx->aad_space,
1137                            sizeof(sw_ctx->aad_space));
1138                 sg_unmark_end(&sw_ctx->sg_aead_out[1]);
1139                 sg_chain(sw_ctx->sg_aead_out, 2, sw_ctx->sg_encrypted_data);
1140         }
1141
1142         if (!*aead) {
1143                 *aead = crypto_alloc_aead("gcm(aes)", 0, 0);
1144                 if (IS_ERR(*aead)) {
1145                         rc = PTR_ERR(*aead);
1146                         *aead = NULL;
1147                         goto free_rec_seq;
1148                 }
1149         }
1150
1151         ctx->push_pending_record = tls_sw_push_pending_record;
1152
1153         memcpy(keyval, gcm_128_info->key, TLS_CIPHER_AES_GCM_128_KEY_SIZE);
1154
1155         rc = crypto_aead_setkey(*aead, keyval,
1156                                 TLS_CIPHER_AES_GCM_128_KEY_SIZE);
1157         if (rc)
1158                 goto free_aead;
1159
1160         rc = crypto_aead_setauthsize(*aead, cctx->tag_size);
1161         if (rc)
1162                 goto free_aead;
1163
1164         if (!tx) {
1165                 /* Set up strparser */
1166                 memset(&cb, 0, sizeof(cb));
1167                 cb.rcv_msg = tls_queue;
1168                 cb.parse_msg = tls_read_size;
1169
1170                 strp_init(&sw_ctx->strp, sk, &cb);
1171
1172                 write_lock_bh(&sk->sk_callback_lock);
1173                 sw_ctx->saved_data_ready = sk->sk_data_ready;
1174                 sk->sk_data_ready = tls_data_ready;
1175                 write_unlock_bh(&sk->sk_callback_lock);
1176
1177                 sw_ctx->sk_poll = sk->sk_socket->ops->poll;
1178
1179                 strp_check_rcv(&sw_ctx->strp);
1180         }
1181
1182         goto out;
1183
1184 free_aead:
1185         crypto_free_aead(*aead);
1186         *aead = NULL;
1187 free_rec_seq:
1188         kfree(cctx->rec_seq);
1189         cctx->rec_seq = NULL;
1190 free_iv:
1191         kfree(ctx->tx.iv);
1192         ctx->tx.iv = NULL;
1193 free_priv:
1194         kfree(ctx->priv_ctx);
1195         ctx->priv_ctx = NULL;
1196 out:
1197         return rc;
1198 }