net/tls/tls_device.c

   1 /* Copyright (c) 2018, Mellanox Technologies All rights reserved.
   2  *
   3  * This software is available to you under a choice of one of two
   4  * licenses.  You may choose to be licensed under the terms of the GNU
   5  * General Public License (GPL) Version 2, available from the file
   6  * COPYING in the main directory of this source tree, or the
   7  * OpenIB.org BSD license below:
   8  *
   9  *     Redistribution and use in source and binary forms, with or
  10  *     without modification, are permitted provided that the following
  11  *     conditions are met:
  12  *
  13  *      - Redistributions of source code must retain the above
  14  *        copyright notice, this list of conditions and the following
  15  *        disclaimer.
  16  *
  17  *      - Redistributions in binary form must reproduce the above
  18  *        copyright notice, this list of conditions and the following
  19  *        disclaimer in the documentation and/or other materials
  20  *        provided with the distribution.
  21  *
  22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  26  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  27  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  28  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  29  * SOFTWARE.
  30  */
  31
  32 #include <crypto/aead.h>
  33 #include <linux/highmem.h>
  34 #include <linux/module.h>
  35 #include <linux/netdevice.h>
  36 #include <net/dst.h>
  37 #include <net/inet_connection_sock.h>
  38 #include <net/tcp.h>
  39 #include <net/tls.h>
  40
  41 /* device_offload_lock is used to synchronize tls_dev_add
  42  * against NETDEV_DOWN notifications.
  43  */
  44 static DECLARE_RWSEM(device_offload_lock);
  45
  46 static void tls_device_gc_task(struct work_struct *work);
  47
  48 static DECLARE_WORK(tls_device_gc_work, tls_device_gc_task);
  49 static LIST_HEAD(tls_device_gc_list);
  50 static LIST_HEAD(tls_device_list);
  51 static DEFINE_SPINLOCK(tls_device_lock);
  52
  53 static void tls_device_free_ctx(struct tls_context *ctx)
  54 {
  55         if (ctx->tx_conf == TLS_HW) {
  56                 kfree(tls_offload_ctx_tx(ctx));
  57                 kfree(ctx->tx.rec_seq);
  58                 kfree(ctx->tx.iv);
  59         }
  60
  61         if (ctx->rx_conf == TLS_HW)
  62                 kfree(tls_offload_ctx_rx(ctx));
  63
  64         kfree(ctx);
  65 }
  66
  67 static void tls_device_gc_task(struct work_struct *work)
  68 {
  69         struct tls_context *ctx, *tmp;
  70         unsigned long flags;
  71         LIST_HEAD(gc_list);
  72
  73         spin_lock_irqsave(&tls_device_lock, flags);
  74         list_splice_init(&tls_device_gc_list, &gc_list);
  75         spin_unlock_irqrestore(&tls_device_lock, flags);
  76
  77         list_for_each_entry_safe(ctx, tmp, &gc_list, list) {
  78                 struct net_device *netdev = ctx->netdev;
  79
  80                 if (netdev && ctx->tx_conf == TLS_HW) {
  81                         netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
  82                                                         TLS_OFFLOAD_CTX_DIR_TX);
  83                         dev_put(netdev);
  84                         ctx->netdev = NULL;
  85                 }
  86
  87                 list_del(&ctx->list);
  88                 tls_device_free_ctx(ctx);
  89         }
  90 }
  91
  92 static void tls_device_attach(struct tls_context *ctx, struct sock *sk,
  93                               struct net_device *netdev)
  94 {
  95         if (sk->sk_destruct != tls_device_sk_destruct) {
  96                 refcount_set(&ctx->refcount, 1);
  97                 dev_hold(netdev);
  98                 ctx->netdev = netdev;
  99                 spin_lock_irq(&tls_device_lock);
 100                 list_add_tail(&ctx->list, &tls_device_list);
 101                 spin_unlock_irq(&tls_device_lock);
 102
 103                 ctx->sk_destruct = sk->sk_destruct;
 104                 sk->sk_destruct = tls_device_sk_destruct;
 105         }
 106 }
 107
 108 static void tls_device_queue_ctx_destruction(struct tls_context *ctx)
 109 {
 110         unsigned long flags;
 111
 112         spin_lock_irqsave(&tls_device_lock, flags);
 113         list_move_tail(&ctx->list, &tls_device_gc_list);
 114
 115         /* schedule_work inside the spinlock
 116          * to make sure tls_device_down waits for that work.
 117          */
 118         schedule_work(&tls_device_gc_work);
 119
 120         spin_unlock_irqrestore(&tls_device_lock, flags);
 121 }
 122
 123 /* We assume that the socket is already connected */
 124 static struct net_device *get_netdev_for_sock(struct sock *sk)
 125 {
 126         struct dst_entry *dst = sk_dst_get(sk);
 127         struct net_device *netdev = NULL;
 128
 129         if (likely(dst)) {
 130                 netdev = dst->dev;
 131                 dev_hold(netdev);
 132         }
 133
 134         dst_release(dst);
 135
 136         return netdev;
 137 }
 138
 139 static void destroy_record(struct tls_record_info *record)
 140 {
 141         int nr_frags = record->num_frags;
 142         skb_frag_t *frag;
 143
 144         while (nr_frags-- > 0) {
 145                 frag = &record->frags[nr_frags];
 146                 __skb_frag_unref(frag);
 147         }
 148         kfree(record);
 149 }
 150
 151 static void delete_all_records(struct tls_offload_context_tx *offload_ctx)
 152 {
 153         struct tls_record_info *info, *temp;
 154
 155         list_for_each_entry_safe(info, temp, &offload_ctx->records_list, list) {
 156                 list_del(&info->list);
 157                 destroy_record(info);
 158         }
 159
 160         offload_ctx->retransmit_hint = NULL;
 161 }
 162
 163 static void tls_icsk_clean_acked(struct sock *sk, u32 acked_seq)
 164 {
 165         struct tls_context *tls_ctx = tls_get_ctx(sk);
 166         struct tls_record_info *info, *temp;
 167         struct tls_offload_context_tx *ctx;
 168         u64 deleted_records = 0;
 169         unsigned long flags;
 170
 171         if (!tls_ctx)
 172                 return;
 173
 174         ctx = tls_offload_ctx_tx(tls_ctx);
 175
 176         spin_lock_irqsave(&ctx->lock, flags);
 177         info = ctx->retransmit_hint;
 178         if (info && !before(acked_seq, info->end_seq)) {
 179                 ctx->retransmit_hint = NULL;
 180                 list_del(&info->list);
 181                 destroy_record(info);
 182                 deleted_records++;
 183         }
 184
 185         list_for_each_entry_safe(info, temp, &ctx->records_list, list) {
 186                 if (before(acked_seq, info->end_seq))
 187                         break;
 188                 list_del(&info->list);
 189
 190                 destroy_record(info);
 191                 deleted_records++;
 192         }
 193
 194         ctx->unacked_record_sn += deleted_records;
 195         spin_unlock_irqrestore(&ctx->lock, flags);
 196 }
 197
 198 /* At this point, there should be no references on this
 199  * socket and no in-flight SKBs associated with this
 200  * socket, so it is safe to free all the resources.
 201  */
 202 void tls_device_sk_destruct(struct sock *sk)
 203 {
 204         struct tls_context *tls_ctx = tls_get_ctx(sk);
 205         struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
 206
 207         tls_ctx->sk_destruct(sk);
 208
 209         if (tls_ctx->tx_conf == TLS_HW) {
 210                 if (ctx->open_record)
 211                         destroy_record(ctx->open_record);
 212                 delete_all_records(ctx);
 213                 crypto_free_aead(ctx->aead_send);
 214                 clean_acked_data_disable(inet_csk(sk));
 215         }
 216
 217         if (refcount_dec_and_test(&tls_ctx->refcount))
 218                 tls_device_queue_ctx_destruction(tls_ctx);
 219 }
 220 EXPORT_SYMBOL(tls_device_sk_destruct);
 221
 222 void tls_device_free_resources_tx(struct sock *sk)
 223 {
 224         struct tls_context *tls_ctx = tls_get_ctx(sk);
 225
 226         tls_free_partial_record(sk, tls_ctx);
 227 }
 228
 229 static void tls_append_frag(struct tls_record_info *record,
 230                             struct page_frag *pfrag,
 231                             int size)
 232 {
 233         skb_frag_t *frag;
 234
 235         frag = &record->frags[record->num_frags - 1];
 236         if (frag->page.p == pfrag->page &&
 237             frag->page_offset + frag->size == pfrag->offset) {
 238                 frag->size += size;
 239         } else {
 240                 ++frag;
 241                 frag->page.p = pfrag->page;
 242                 frag->page_offset = pfrag->offset;
 243                 frag->size = size;
 244                 ++record->num_frags;
 245                 get_page(pfrag->page);
 246         }
 247
 248         pfrag->offset += size;
 249         record->len += size;
 250 }
 251
 252 static int tls_push_record(struct sock *sk,
 253                            struct tls_context *ctx,
 254                            struct tls_offload_context_tx *offload_ctx,
 255                            struct tls_record_info *record,
 256                            struct page_frag *pfrag,
 257                            int flags,
 258                            unsigned char record_type)
 259 {
 260         struct tls_prot_info *prot = &ctx->prot_info;
 261         struct tcp_sock *tp = tcp_sk(sk);
 262         struct page_frag dummy_tag_frag;
 263         skb_frag_t *frag;
 264         int i;
 265
 266         /* fill prepend */
 267         frag = &record->frags[0];
 268         tls_fill_prepend(ctx,
 269                          skb_frag_address(frag),
 270                          record->len - prot->prepend_size,
 271                          record_type,
 272                          ctx->crypto_send.info.version);
 273
 274         /* HW doesn't care about the data in the tag, because it fills it. */
 275         dummy_tag_frag.page = skb_frag_page(frag);
 276         dummy_tag_frag.offset = 0;
 277
 278         tls_append_frag(record, &dummy_tag_frag, prot->tag_size);
 279         record->end_seq = tp->write_seq + record->len;
 280         spin_lock_irq(&offload_ctx->lock);
 281         list_add_tail(&record->list, &offload_ctx->records_list);
 282         spin_unlock_irq(&offload_ctx->lock);
 283         offload_ctx->open_record = NULL;
 284         tls_advance_record_sn(sk, &ctx->tx, ctx->crypto_send.info.version);
 285
 286         for (i = 0; i < record->num_frags; i++) {
 287                 frag = &record->frags[i];
 288                 sg_unmark_end(&offload_ctx->sg_tx_data[i]);
 289                 sg_set_page(&offload_ctx->sg_tx_data[i], skb_frag_page(frag),
 290                             frag->size, frag->page_offset);
 291                 sk_mem_charge(sk, frag->size);
 292                 get_page(skb_frag_page(frag));
 293         }
 294         sg_mark_end(&offload_ctx->sg_tx_data[record->num_frags - 1]);
 295
 296         /* all ready, send */
 297         return tls_push_sg(sk, ctx, offload_ctx->sg_tx_data, 0, flags);
 298 }
 299
 300 static int tls_create_new_record(struct tls_offload_context_tx *offload_ctx,
 301                                  struct page_frag *pfrag,
 302                                  size_t prepend_size)
 303 {
 304         struct tls_record_info *record;
 305         skb_frag_t *frag;
 306
 307         record = kmalloc(sizeof(*record), GFP_KERNEL);
 308         if (!record)
 309                 return -ENOMEM;
 310
 311         frag = &record->frags[0];
 312         __skb_frag_set_page(frag, pfrag->page);
 313         frag->page_offset = pfrag->offset;
 314         skb_frag_size_set(frag, prepend_size);
 315
 316         get_page(pfrag->page);
 317         pfrag->offset += prepend_size;
 318
 319         record->num_frags = 1;
 320         record->len = prepend_size;
 321         offload_ctx->open_record = record;
 322         return 0;
 323 }
 324
 325 static int tls_do_allocation(struct sock *sk,
 326                              struct tls_offload_context_tx *offload_ctx,
 327                              struct page_frag *pfrag,
 328                              size_t prepend_size)
 329 {
 330         int ret;
 331
 332         if (!offload_ctx->open_record) {
 333                 if (unlikely(!skb_page_frag_refill(prepend_size, pfrag,
 334                                                    sk->sk_allocation))) {
 335                         sk->sk_prot->enter_memory_pressure(sk);
 336                         sk_stream_moderate_sndbuf(sk);
 337                         return -ENOMEM;
 338                 }
 339
 340                 ret = tls_create_new_record(offload_ctx, pfrag, prepend_size);
 341                 if (ret)
 342                         return ret;
 343
 344                 if (pfrag->size > pfrag->offset)
 345                         return 0;
 346         }
 347
 348         if (!sk_page_frag_refill(sk, pfrag))
 349                 return -ENOMEM;
 350
 351         return 0;
 352 }
 353
 354 static int tls_push_data(struct sock *sk,
 355                          struct iov_iter *msg_iter,
 356                          size_t size, int flags,
 357                          unsigned char record_type)
 358 {
 359         struct tls_context *tls_ctx = tls_get_ctx(sk);
 360         struct tls_prot_info *prot = &tls_ctx->prot_info;
 361         struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
 362         int tls_push_record_flags = flags | MSG_SENDPAGE_NOTLAST;
 363         int more = flags & (MSG_SENDPAGE_NOTLAST | MSG_MORE);
 364         struct tls_record_info *record = ctx->open_record;
 365         struct page_frag *pfrag;
 366         size_t orig_size = size;
 367         u32 max_open_record_len;
 368         int copy, rc = 0;
 369         bool done = false;
 370         long timeo;
 371
 372         if (flags &
 373             ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL | MSG_SENDPAGE_NOTLAST))
 374                 return -ENOTSUPP;
 375
 376         if (sk->sk_err)
 377                 return -sk->sk_err;
 378
 379         timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
 380         if (tls_is_partially_sent_record(tls_ctx)) {
 381                 rc = tls_push_partial_record(sk, tls_ctx, flags);
 382                 if (rc < 0)
 383                         return rc;
 384         }
 385
 386         pfrag = sk_page_frag(sk);
 387
 388         /* TLS_HEADER_SIZE is not counted as part of the TLS record, and
 389          * we need to leave room for an authentication tag.
 390          */
 391         max_open_record_len = TLS_MAX_PAYLOAD_SIZE +
 392                               prot->prepend_size;
 393         do {
 394                 rc = tls_do_allocation(sk, ctx, pfrag,
 395                                        prot->prepend_size);
 396                 if (rc) {
 397                         rc = sk_stream_wait_memory(sk, &timeo);
 398                         if (!rc)
 399                                 continue;
 400
 401                         record = ctx->open_record;
 402                         if (!record)
 403                                 break;
 404 handle_error:
 405                         if (record_type != TLS_RECORD_TYPE_DATA) {
 406                                 /* avoid sending partial
 407                                  * record with type !=
 408                                  * application_data
 409                                  */
 410                                 size = orig_size;
 411                                 destroy_record(record);
 412                                 ctx->open_record = NULL;
 413                         } else if (record->len > prot->prepend_size) {
 414                                 goto last_record;
 415                         }
 416
 417                         break;
 418                 }
 419
 420                 record = ctx->open_record;
 421                 copy = min_t(size_t, size, (pfrag->size - pfrag->offset));
 422                 copy = min_t(size_t, copy, (max_open_record_len - record->len));
 423
 424                 if (copy_from_iter_nocache(page_address(pfrag->page) +
 425                                                pfrag->offset,
 426                                            copy, msg_iter) != copy) {
 427                         rc = -EFAULT;
 428                         goto handle_error;
 429                 }
 430                 tls_append_frag(record, pfrag, copy);
 431
 432                 size -= copy;
 433                 if (!size) {
 434 last_record:
 435                         tls_push_record_flags = flags;
 436                         if (more) {
 437                                 tls_ctx->pending_open_record_frags =
 438                                                 !!record->num_frags;
 439                                 break;
 440                         }
 441
 442                         done = true;
 443                 }
 444
 445                 if (done || record->len >= max_open_record_len ||
 446                     (record->num_frags >= MAX_SKB_FRAGS - 1)) {
 447                         rc = tls_push_record(sk,
 448                                              tls_ctx,
 449                                              ctx,
 450                                              record,
 451                                              pfrag,
 452                                              tls_push_record_flags,
 453                                              record_type);
 454                         if (rc < 0)
 455                                 break;
 456                 }
 457         } while (!done);
 458
 459         if (orig_size - size > 0)
 460                 rc = orig_size - size;
 461
 462         return rc;
 463 }
 464
 465 int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
 466 {
 467         unsigned char record_type = TLS_RECORD_TYPE_DATA;
 468         int rc;
 469
 470         lock_sock(sk);
 471
 472         if (unlikely(msg->msg_controllen)) {
 473                 rc = tls_proccess_cmsg(sk, msg, &record_type);
 474                 if (rc)
 475                         goto out;
 476         }
 477
 478         rc = tls_push_data(sk, &msg->msg_iter, size,
 479                            msg->msg_flags, record_type);
 480
 481 out:
 482         release_sock(sk);
 483         return rc;
 484 }
 485
 486 int tls_device_sendpage(struct sock *sk, struct page *page,
 487                         int offset, size_t size, int flags)
 488 {
 489         struct iov_iter msg_iter;
 490         char *kaddr = kmap(page);
 491         struct kvec iov;
 492         int rc;
 493
 494         if (flags & MSG_SENDPAGE_NOTLAST)
 495                 flags |= MSG_MORE;
 496
 497         lock_sock(sk);
 498
 499         if (flags & MSG_OOB) {
 500                 rc = -ENOTSUPP;
 501                 goto out;
 502         }
 503
 504         iov.iov_base = kaddr + offset;
 505         iov.iov_len = size;
 506         iov_iter_kvec(&msg_iter, WRITE, &iov, 1, size);
 507         rc = tls_push_data(sk, &msg_iter, size,
 508                            flags, TLS_RECORD_TYPE_DATA);
 509         kunmap(page);
 510
 511 out:
 512         release_sock(sk);
 513         return rc;
 514 }
 515
 516 struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context,
 517                                        u32 seq, u64 *p_record_sn)
 518 {
 519         u64 record_sn = context->hint_record_sn;
 520         struct tls_record_info *info;
 521
 522         info = context->retransmit_hint;
 523         if (!info ||
 524             before(seq, info->end_seq - info->len)) {
 525                 /* if retransmit_hint is irrelevant start
 526                  * from the beggining of the list
 527                  */
 528                 info = list_first_entry(&context->records_list,
 529                                         struct tls_record_info, list);
 530                 record_sn = context->unacked_record_sn;
 531         }
 532
 533         list_for_each_entry_from(info, &context->records_list, list) {
 534                 if (before(seq, info->end_seq)) {
 535                         if (!context->retransmit_hint ||
 536                             after(info->end_seq,
 537                                   context->retransmit_hint->end_seq)) {
 538                                 context->hint_record_sn = record_sn;
 539                                 context->retransmit_hint = info;
 540                         }
 541                         *p_record_sn = record_sn;
 542                         return info;
 543                 }
 544                 record_sn++;
 545         }
 546
 547         return NULL;
 548 }
 549 EXPORT_SYMBOL(tls_get_record);
 550
 551 static int tls_device_push_pending_record(struct sock *sk, int flags)
 552 {
 553         struct iov_iter msg_iter;
 554
 555         iov_iter_kvec(&msg_iter, WRITE, NULL, 0, 0);
 556         return tls_push_data(sk, &msg_iter, 0, flags, TLS_RECORD_TYPE_DATA);
 557 }
 558
 559 void tls_device_write_space(struct sock *sk, struct tls_context *ctx)
 560 {
 561         int rc = 0;
 562
 563         if (!sk->sk_write_pending && tls_is_partially_sent_record(ctx)) {
 564                 gfp_t sk_allocation = sk->sk_allocation;
 565
 566                 sk->sk_allocation = GFP_ATOMIC;
 567                 rc = tls_push_partial_record(sk, ctx,
 568                                              MSG_DONTWAIT | MSG_NOSIGNAL);
 569                 sk->sk_allocation = sk_allocation;
 570         }
 571 }
 572
 573 void handle_device_resync(struct sock *sk, u32 seq, u64 rcd_sn)
 574 {
 575         struct tls_context *tls_ctx = tls_get_ctx(sk);
 576         struct net_device *netdev = tls_ctx->netdev;
 577         struct tls_offload_context_rx *rx_ctx;
 578         u32 is_req_pending;
 579         s64 resync_req;
 580         u32 req_seq;
 581
 582         if (tls_ctx->rx_conf != TLS_HW)
 583                 return;
 584
 585         rx_ctx = tls_offload_ctx_rx(tls_ctx);
 586         resync_req = atomic64_read(&rx_ctx->resync_req);
 587         req_seq = ntohl(resync_req >> 32) - ((u32)TLS_HEADER_SIZE - 1);
 588         is_req_pending = resync_req;
 589
 590         if (unlikely(is_req_pending) && req_seq == seq &&
 591             atomic64_try_cmpxchg(&rx_ctx->resync_req, &resync_req, 0))
 592                 netdev->tlsdev_ops->tls_dev_resync_rx(netdev, sk,
 593                                                       seq + TLS_HEADER_SIZE - 1,
 594                                                       rcd_sn);
 595 }
 596
 597 static int tls_device_reencrypt(struct sock *sk, struct sk_buff *skb)
 598 {
 599         struct strp_msg *rxm = strp_msg(skb);
 600         int err = 0, offset = rxm->offset, copy, nsg;
 601         struct sk_buff *skb_iter, *unused;
 602         struct scatterlist sg[1];
 603         char *orig_buf, *buf;
 604
 605         orig_buf = kmalloc(rxm->full_len + TLS_HEADER_SIZE +
 606                            TLS_CIPHER_AES_GCM_128_IV_SIZE, sk->sk_allocation);
 607         if (!orig_buf)
 608                 return -ENOMEM;
 609         buf = orig_buf;
 610
 611         nsg = skb_cow_data(skb, 0, &unused);
 612         if (unlikely(nsg < 0)) {
 613                 err = nsg;
 614                 goto free_buf;
 615         }
 616
 617         sg_init_table(sg, 1);
 618         sg_set_buf(&sg[0], buf,
 619                    rxm->full_len + TLS_HEADER_SIZE +
 620                    TLS_CIPHER_AES_GCM_128_IV_SIZE);
 621         skb_copy_bits(skb, offset, buf,
 622                       TLS_HEADER_SIZE + TLS_CIPHER_AES_GCM_128_IV_SIZE);
 623
 624         /* We are interested only in the decrypted data not the auth */
 625         err = decrypt_skb(sk, skb, sg);
 626         if (err != -EBADMSG)
 627                 goto free_buf;
 628         else
 629                 err = 0;
 630
 631         copy = min_t(int, skb_pagelen(skb) - offset,
 632                      rxm->full_len - TLS_CIPHER_AES_GCM_128_TAG_SIZE);
 633
 634         if (skb->decrypted)
 635                 skb_store_bits(skb, offset, buf, copy);
 636
 637         offset += copy;
 638         buf += copy;
 639
 640         skb_walk_frags(skb, skb_iter) {
 641                 copy = min_t(int, skb_iter->len,
 642                              rxm->full_len - offset + rxm->offset -
 643                              TLS_CIPHER_AES_GCM_128_TAG_SIZE);
 644
 645                 if (skb_iter->decrypted)
 646                         skb_store_bits(skb_iter, offset, buf, copy);
 647
 648                 offset += copy;
 649                 buf += copy;
 650         }
 651
 652 free_buf:
 653         kfree(orig_buf);
 654         return err;
 655 }
 656
 657 int tls_device_decrypted(struct sock *sk, struct sk_buff *skb)
 658 {
 659         struct tls_context *tls_ctx = tls_get_ctx(sk);
 660         struct tls_offload_context_rx *ctx = tls_offload_ctx_rx(tls_ctx);
 661         int is_decrypted = skb->decrypted;
 662         int is_encrypted = !is_decrypted;
 663         struct sk_buff *skb_iter;
 664
 665         /* Skip if it is already decrypted */
 666         if (ctx->sw.decrypted)
 667                 return 0;
 668
 669         /* Check if all the data is decrypted already */
 670         skb_walk_frags(skb, skb_iter) {
 671                 is_decrypted &= skb_iter->decrypted;
 672                 is_encrypted &= !skb_iter->decrypted;
 673         }
 674
 675         ctx->sw.decrypted |= is_decrypted;
 676
 677         /* Return immedeatly if the record is either entirely plaintext or
 678          * entirely ciphertext. Otherwise handle reencrypt partially decrypted
 679          * record.
 680          */
 681         return (is_encrypted || is_decrypted) ? 0 :
 682                 tls_device_reencrypt(sk, skb);
 683 }
 684
 685 int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
 686 {
 687         u16 nonce_size, tag_size, iv_size, rec_seq_size;
 688         struct tls_context *tls_ctx = tls_get_ctx(sk);
 689         struct tls_prot_info *prot = &tls_ctx->prot_info;
 690         struct tls_record_info *start_marker_record;
 691         struct tls_offload_context_tx *offload_ctx;
 692         struct tls_crypto_info *crypto_info;
 693         struct net_device *netdev;
 694         char *iv, *rec_seq;
 695         struct sk_buff *skb;
 696         int rc = -EINVAL;
 697         __be64 rcd_sn;
 698
 699         if (!ctx)
 700                 goto out;
 701
 702         if (ctx->priv_ctx_tx) {
 703                 rc = -EEXIST;
 704                 goto out;
 705         }
 706
 707         start_marker_record = kmalloc(sizeof(*start_marker_record), GFP_KERNEL);
 708         if (!start_marker_record) {
 709                 rc = -ENOMEM;
 710                 goto out;
 711         }
 712
 713         offload_ctx = kzalloc(TLS_OFFLOAD_CONTEXT_SIZE_TX, GFP_KERNEL);
 714         if (!offload_ctx) {
 715                 rc = -ENOMEM;
 716                 goto free_marker_record;
 717         }
 718
 719         crypto_info = &ctx->crypto_send.info;
 720         switch (crypto_info->cipher_type) {
 721         case TLS_CIPHER_AES_GCM_128:
 722                 nonce_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
 723                 tag_size = TLS_CIPHER_AES_GCM_128_TAG_SIZE;
 724                 iv_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
 725                 iv = ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->iv;
 726                 rec_seq_size = TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE;
 727                 rec_seq =
 728                  ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->rec_seq;
 729                 break;
 730         default:
 731                 rc = -EINVAL;
 732                 goto free_offload_ctx;
 733         }
 734
 735         prot->prepend_size = TLS_HEADER_SIZE + nonce_size;
 736         prot->tag_size = tag_size;
 737         prot->overhead_size = prot->prepend_size + prot->tag_size;
 738         prot->iv_size = iv_size;
 739         ctx->tx.iv = kmalloc(iv_size + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
 740                              GFP_KERNEL);
 741         if (!ctx->tx.iv) {
 742                 rc = -ENOMEM;
 743                 goto free_offload_ctx;
 744         }
 745
 746         memcpy(ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv, iv_size);
 747
 748         prot->rec_seq_size = rec_seq_size;
 749         ctx->tx.rec_seq = kmemdup(rec_seq, rec_seq_size, GFP_KERNEL);
 750         if (!ctx->tx.rec_seq) {
 751                 rc = -ENOMEM;
 752                 goto free_iv;
 753         }
 754
 755         rc = tls_sw_fallback_init(sk, offload_ctx, crypto_info);
 756         if (rc)
 757                 goto free_rec_seq;
 758
 759         /* start at rec_seq - 1 to account for the start marker record */
 760         memcpy(&rcd_sn, ctx->tx.rec_seq, sizeof(rcd_sn));
 761         offload_ctx->unacked_record_sn = be64_to_cpu(rcd_sn) - 1;
 762
 763         start_marker_record->end_seq = tcp_sk(sk)->write_seq;
 764         start_marker_record->len = 0;
 765         start_marker_record->num_frags = 0;
 766
 767         INIT_LIST_HEAD(&offload_ctx->records_list);
 768         list_add_tail(&start_marker_record->list, &offload_ctx->records_list);
 769         spin_lock_init(&offload_ctx->lock);
 770         sg_init_table(offload_ctx->sg_tx_data,
 771                       ARRAY_SIZE(offload_ctx->sg_tx_data));
 772
 773         clean_acked_data_enable(inet_csk(sk), &tls_icsk_clean_acked);
 774         ctx->push_pending_record = tls_device_push_pending_record;
 775
 776         /* TLS offload is greatly simplified if we don't send
 777          * SKBs where only part of the payload needs to be encrypted.
 778          * So mark the last skb in the write queue as end of record.
 779          */
 780         skb = tcp_write_queue_tail(sk);
 781         if (skb)
 782                 TCP_SKB_CB(skb)->eor = 1;
 783
 784         /* We support starting offload on multiple sockets
 785          * concurrently, so we only need a read lock here.
 786          * This lock must precede get_netdev_for_sock to prevent races between
 787          * NETDEV_DOWN and setsockopt.
 788          */
 789         down_read(&device_offload_lock);
 790         netdev = get_netdev_for_sock(sk);
 791         if (!netdev) {
 792                 pr_err_ratelimited("%s: netdev not found\n", __func__);
 793                 rc = -EINVAL;
 794                 goto release_lock;
 795         }
 796
 797         if (!(netdev->features & NETIF_F_HW_TLS_TX)) {
 798                 rc = -ENOTSUPP;
 799                 goto release_netdev;
 800         }
 801
 802         /* Avoid offloading if the device is down
 803          * We don't want to offload new flows after
 804          * the NETDEV_DOWN event
 805          */
 806         if (!(netdev->flags & IFF_UP)) {
 807                 rc = -EINVAL;
 808                 goto release_netdev;
 809         }
 810
 811         ctx->priv_ctx_tx = offload_ctx;
 812         rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_TX,
 813                                              &ctx->crypto_send.info,
 814                                              tcp_sk(sk)->write_seq);
 815         if (rc)
 816                 goto release_netdev;
 817
 818         tls_device_attach(ctx, sk, netdev);
 819
 820         /* following this assignment tls_is_sk_tx_device_offloaded
 821          * will return true and the context might be accessed
 822          * by the netdev's xmit function.
 823          */
 824         smp_store_release(&sk->sk_validate_xmit_skb, tls_validate_xmit_skb);
 825         dev_put(netdev);
 826         up_read(&device_offload_lock);
 827         goto out;
 828
 829 release_netdev:
 830         dev_put(netdev);
 831 release_lock:
 832         up_read(&device_offload_lock);
 833         clean_acked_data_disable(inet_csk(sk));
 834         crypto_free_aead(offload_ctx->aead_send);
 835 free_rec_seq:
 836         kfree(ctx->tx.rec_seq);
 837 free_iv:
 838         kfree(ctx->tx.iv);
 839 free_offload_ctx:
 840         kfree(offload_ctx);
 841         ctx->priv_ctx_tx = NULL;
 842 free_marker_record:
 843         kfree(start_marker_record);
 844 out:
 845         return rc;
 846 }
 847
 848 int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
 849 {
 850         struct tls_offload_context_rx *context;
 851         struct net_device *netdev;
 852         int rc = 0;
 853
 854         /* We support starting offload on multiple sockets
 855          * concurrently, so we only need a read lock here.
 856          * This lock must precede get_netdev_for_sock to prevent races between
 857          * NETDEV_DOWN and setsockopt.
 858          */
 859         down_read(&device_offload_lock);
 860         netdev = get_netdev_for_sock(sk);
 861         if (!netdev) {
 862                 pr_err_ratelimited("%s: netdev not found\n", __func__);
 863                 rc = -EINVAL;
 864                 goto release_lock;
 865         }
 866
 867         if (!(netdev->features & NETIF_F_HW_TLS_RX)) {
 868                 pr_err_ratelimited("%s: netdev %s with no TLS offload\n",
 869                                    __func__, netdev->name);
 870                 rc = -ENOTSUPP;
 871                 goto release_netdev;
 872         }
 873
 874         /* Avoid offloading if the device is down
 875          * We don't want to offload new flows after
 876          * the NETDEV_DOWN event
 877          */
 878         if (!(netdev->flags & IFF_UP)) {
 879                 rc = -EINVAL;
 880                 goto release_netdev;
 881         }
 882
 883         context = kzalloc(TLS_OFFLOAD_CONTEXT_SIZE_RX, GFP_KERNEL);
 884         if (!context) {
 885                 rc = -ENOMEM;
 886                 goto release_netdev;
 887         }
 888
 889         ctx->priv_ctx_rx = context;
 890         rc = tls_set_sw_offload(sk, ctx, 0);
 891         if (rc)
 892                 goto release_ctx;
 893
 894         rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_RX,
 895                                              &ctx->crypto_recv.info,
 896                                              tcp_sk(sk)->copied_seq);
 897         if (rc) {
 898                 pr_err_ratelimited("%s: The netdev has refused to offload this socket\n",
 899                                    __func__);
 900                 goto free_sw_resources;
 901         }
 902
 903         tls_device_attach(ctx, sk, netdev);
 904         goto release_netdev;
 905
 906 free_sw_resources:
 907         tls_sw_free_resources_rx(sk);
 908 release_ctx:
 909         ctx->priv_ctx_rx = NULL;
 910 release_netdev:
 911         dev_put(netdev);
 912 release_lock:
 913         up_read(&device_offload_lock);
 914         return rc;
 915 }
 916
 917 void tls_device_offload_cleanup_rx(struct sock *sk)
 918 {
 919         struct tls_context *tls_ctx = tls_get_ctx(sk);
 920         struct net_device *netdev;
 921
 922         down_read(&device_offload_lock);
 923         netdev = tls_ctx->netdev;
 924         if (!netdev)
 925                 goto out;
 926
 927         if (!(netdev->features & NETIF_F_HW_TLS_RX)) {
 928                 pr_err_ratelimited("%s: device is missing NETIF_F_HW_TLS_RX cap\n",
 929                                    __func__);
 930                 goto out;
 931         }
 932
 933         netdev->tlsdev_ops->tls_dev_del(netdev, tls_ctx,
 934                                         TLS_OFFLOAD_CTX_DIR_RX);
 935
 936         if (tls_ctx->tx_conf != TLS_HW) {
 937                 dev_put(netdev);
 938                 tls_ctx->netdev = NULL;
 939         }
 940 out:
 941         up_read(&device_offload_lock);
 942         kfree(tls_ctx->rx.rec_seq);
 943         kfree(tls_ctx->rx.iv);
 944         tls_sw_release_resources_rx(sk);
 945 }
 946
 947 static int tls_device_down(struct net_device *netdev)
 948 {
 949         struct tls_context *ctx, *tmp;
 950         unsigned long flags;
 951         LIST_HEAD(list);
 952
 953         /* Request a write lock to block new offload attempts */
 954         down_write(&device_offload_lock);
 955
 956         spin_lock_irqsave(&tls_device_lock, flags);
 957         list_for_each_entry_safe(ctx, tmp, &tls_device_list, list) {
 958                 if (ctx->netdev != netdev ||
 959                     !refcount_inc_not_zero(&ctx->refcount))
 960                         continue;
 961
 962                 list_move(&ctx->list, &list);
 963         }
 964         spin_unlock_irqrestore(&tls_device_lock, flags);
 965
 966         list_for_each_entry_safe(ctx, tmp, &list, list) {
 967                 if (ctx->tx_conf == TLS_HW)
 968                         netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
 969                                                         TLS_OFFLOAD_CTX_DIR_TX);
 970                 if (ctx->rx_conf == TLS_HW)
 971                         netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
 972                                                         TLS_OFFLOAD_CTX_DIR_RX);
 973                 ctx->netdev = NULL;
 974                 dev_put(netdev);
 975                 list_del_init(&ctx->list);
 976
 977                 if (refcount_dec_and_test(&ctx->refcount))
 978                         tls_device_free_ctx(ctx);
 979         }
 980
 981         up_write(&device_offload_lock);
 982
 983         flush_work(&tls_device_gc_work);
 984
 985         return NOTIFY_DONE;
 986 }
 987
 988 static int tls_dev_event(struct notifier_block *this, unsigned long event,
 989                          void *ptr)
 990 {
 991         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 992
 993         if (!(dev->features & (NETIF_F_HW_TLS_RX | NETIF_F_HW_TLS_TX)))
 994                 return NOTIFY_DONE;
 995
 996         switch (event) {
 997         case NETDEV_REGISTER:
 998         case NETDEV_FEAT_CHANGE:
 999                 if ((dev->features & NETIF_F_HW_TLS_RX) &&
1000                     !dev->tlsdev_ops->tls_dev_resync_rx)
1001                         return NOTIFY_BAD;
1002
1003                 if  (dev->tlsdev_ops &&
1004                      dev->tlsdev_ops->tls_dev_add &&
1005                      dev->tlsdev_ops->tls_dev_del)
1006                         return NOTIFY_DONE;
1007                 else
1008                         return NOTIFY_BAD;
1009         case NETDEV_DOWN:
1010                 return tls_device_down(dev);
1011         }
1012         return NOTIFY_DONE;
1013 }
1014
1015 static struct notifier_block tls_dev_notifier = {
1016         .notifier_call  = tls_dev_event,
1017 };
1018
1019 void __init tls_device_init(void)
1020 {
1021         register_netdevice_notifier(&tls_dev_notifier);
1022 }
1023
1024 void __exit tls_device_cleanup(void)
1025 {
1026         unregister_netdevice_notifier(&tls_dev_notifier);
1027         flush_work(&tls_device_gc_work);
1028 }