crypto/algif_skcipher.c

   1 /*
   2  * algif_skcipher: User-space interface for skcipher algorithms
   3  *
   4  * This file provides the user-space API for symmetric key ciphers.
   5  *
   6  * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License as published by the Free
  10  * Software Foundation; either version 2 of the License, or (at your option)
  11  * any later version.
  12  *
  13  */
  14
  15 #include <crypto/scatterwalk.h>
  16 #include <crypto/skcipher.h>
  17 #include <crypto/if_alg.h>
  18 #include <linux/init.h>
  19 #include <linux/list.h>
  20 #include <linux/kernel.h>
  21 #include <linux/mm.h>
  22 #include <linux/module.h>
  23 #include <linux/net.h>
  24 #include <net/sock.h>
  25
  26 struct skcipher_sg_list {
  27         struct list_head list;
  28
  29         int cur;
  30
  31         struct scatterlist sg[0];
  32 };
  33
  34 struct skcipher_tfm {
  35         struct crypto_ablkcipher *skcipher;
  36         bool has_key;
  37 };
  38
  39 struct skcipher_ctx {
  40         struct list_head tsgl;
  41         struct af_alg_sgl rsgl;
  42
  43         void *iv;
  44
  45         struct af_alg_completion completion;
  46
  47         unsigned used;
  48
  49         unsigned int len;
  50         bool more;
  51         bool merge;
  52         bool enc;
  53
  54         struct ablkcipher_request req;
  55 };
  56
  57 #define MAX_SGL_ENTS ((4096 - sizeof(struct skcipher_sg_list)) / \
  58                       sizeof(struct scatterlist) - 1)
  59
  60 static inline int skcipher_sndbuf(struct sock *sk)
  61 {
  62         struct alg_sock *ask = alg_sk(sk);
  63         struct skcipher_ctx *ctx = ask->private;
  64
  65         return max_t(int, max_t(int, sk->sk_sndbuf & PAGE_MASK, PAGE_SIZE) -
  66                           ctx->used, 0);
  67 }
  68
  69 static inline bool skcipher_writable(struct sock *sk)
  70 {
  71         return PAGE_SIZE <= skcipher_sndbuf(sk);
  72 }
  73
  74 static int skcipher_alloc_sgl(struct sock *sk)
  75 {
  76         struct alg_sock *ask = alg_sk(sk);
  77         struct skcipher_ctx *ctx = ask->private;
  78         struct skcipher_sg_list *sgl;
  79         struct scatterlist *sg = NULL;
  80
  81         sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
  82         if (!list_empty(&ctx->tsgl))
  83                 sg = sgl->sg;
  84
  85         if (!sg || sgl->cur >= MAX_SGL_ENTS) {
  86                 sgl = sock_kmalloc(sk, sizeof(*sgl) +
  87                                        sizeof(sgl->sg[0]) * (MAX_SGL_ENTS + 1),
  88                                    GFP_KERNEL);
  89                 if (!sgl)
  90                         return -ENOMEM;
  91
  92                 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
  93                 sgl->cur = 0;
  94
  95                 if (sg)
  96                         scatterwalk_sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
  97
  98                 list_add_tail(&sgl->list, &ctx->tsgl);
  99         }
 100
 101         return 0;
 102 }
 103
 104 static void skcipher_pull_sgl(struct sock *sk, int used)
 105 {
 106         struct alg_sock *ask = alg_sk(sk);
 107         struct skcipher_ctx *ctx = ask->private;
 108         struct skcipher_sg_list *sgl;
 109         struct scatterlist *sg;
 110         int i;
 111
 112         while (!list_empty(&ctx->tsgl)) {
 113                 sgl = list_first_entry(&ctx->tsgl, struct skcipher_sg_list,
 114                                        list);
 115                 sg = sgl->sg;
 116
 117                 for (i = 0; i < sgl->cur; i++) {
 118                         int plen = min_t(int, used, sg[i].length);
 119
 120                         if (!sg_page(sg + i))
 121                                 continue;
 122
 123                         sg[i].length -= plen;
 124                         sg[i].offset += plen;
 125
 126                         used -= plen;
 127                         ctx->used -= plen;
 128
 129                         if (sg[i].length)
 130                                 return;
 131
 132                         put_page(sg_page(sg + i));
 133                         sg_assign_page(sg + i, NULL);
 134                 }
 135
 136                 list_del(&sgl->list);
 137                 sock_kfree_s(sk, sgl,
 138                              sizeof(*sgl) + sizeof(sgl->sg[0]) *
 139                                             (MAX_SGL_ENTS + 1));
 140         }
 141
 142         if (!ctx->used)
 143                 ctx->merge = 0;
 144 }
 145
 146 static void skcipher_free_sgl(struct sock *sk)
 147 {
 148         struct alg_sock *ask = alg_sk(sk);
 149         struct skcipher_ctx *ctx = ask->private;
 150
 151         skcipher_pull_sgl(sk, ctx->used);
 152 }
 153
 154 static int skcipher_wait_for_wmem(struct sock *sk, unsigned flags)
 155 {
 156         long timeout;
 157         DEFINE_WAIT(wait);
 158         int err = -ERESTARTSYS;
 159
 160         if (flags & MSG_DONTWAIT)
 161                 return -EAGAIN;
 162
 163         set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
 164
 165         for (;;) {
 166                 if (signal_pending(current))
 167                         break;
 168                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 169                 timeout = MAX_SCHEDULE_TIMEOUT;
 170                 if (sk_wait_event(sk, &timeout, skcipher_writable(sk))) {
 171                         err = 0;
 172                         break;
 173                 }
 174         }
 175         finish_wait(sk_sleep(sk), &wait);
 176
 177         return err;
 178 }
 179
 180 static void skcipher_wmem_wakeup(struct sock *sk)
 181 {
 182         struct socket_wq *wq;
 183
 184         if (!skcipher_writable(sk))
 185                 return;
 186
 187         rcu_read_lock();
 188         wq = rcu_dereference(sk->sk_wq);
 189         if (wq_has_sleeper(wq))
 190                 wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
 191                                                            POLLRDNORM |
 192                                                            POLLRDBAND);
 193         sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
 194         rcu_read_unlock();
 195 }
 196
 197 static int skcipher_wait_for_data(struct sock *sk, unsigned flags)
 198 {
 199         struct alg_sock *ask = alg_sk(sk);
 200         struct skcipher_ctx *ctx = ask->private;
 201         long timeout;
 202         DEFINE_WAIT(wait);
 203         int err = -ERESTARTSYS;
 204
 205         if (flags & MSG_DONTWAIT) {
 206                 return -EAGAIN;
 207         }
 208
 209         set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
 210
 211         for (;;) {
 212                 if (signal_pending(current))
 213                         break;
 214                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 215                 timeout = MAX_SCHEDULE_TIMEOUT;
 216                 if (sk_wait_event(sk, &timeout, ctx->used)) {
 217                         err = 0;
 218                         break;
 219                 }
 220         }
 221         finish_wait(sk_sleep(sk), &wait);
 222
 223         clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
 224
 225         return err;
 226 }
 227
 228 static void skcipher_data_wakeup(struct sock *sk)
 229 {
 230         struct alg_sock *ask = alg_sk(sk);
 231         struct skcipher_ctx *ctx = ask->private;
 232         struct socket_wq *wq;
 233
 234         if (!ctx->used)
 235                 return;
 236
 237         rcu_read_lock();
 238         wq = rcu_dereference(sk->sk_wq);
 239         if (wq_has_sleeper(wq))
 240                 wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
 241                                                            POLLRDNORM |
 242                                                            POLLRDBAND);
 243         sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
 244         rcu_read_unlock();
 245 }
 246
 247 static int skcipher_sendmsg(struct kiocb *unused, struct socket *sock,
 248                             struct msghdr *msg, size_t size)
 249 {
 250         struct sock *sk = sock->sk;
 251         struct alg_sock *ask = alg_sk(sk);
 252         struct skcipher_ctx *ctx = ask->private;
 253         struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(&ctx->req);
 254         unsigned ivsize = crypto_ablkcipher_ivsize(tfm);
 255         struct skcipher_sg_list *sgl;
 256         struct af_alg_control con = {};
 257         long copied = 0;
 258         bool enc = 0;
 259         int err;
 260         int i;
 261
 262         if (msg->msg_controllen) {
 263                 err = af_alg_cmsg_send(msg, &con);
 264                 if (err)
 265                         return err;
 266
 267                 switch (con.op) {
 268                 case ALG_OP_ENCRYPT:
 269                         enc = 1;
 270                         break;
 271                 case ALG_OP_DECRYPT:
 272                         enc = 0;
 273                         break;
 274                 default:
 275                         return -EINVAL;
 276                 }
 277
 278                 if (con.iv && con.iv->ivlen != ivsize)
 279                         return -EINVAL;
 280         }
 281
 282         err = -EINVAL;
 283
 284         lock_sock(sk);
 285         if (!ctx->more && ctx->used)
 286                 goto unlock;
 287
 288         if (!ctx->used) {
 289                 ctx->enc = enc;
 290                 if (con.iv)
 291                         memcpy(ctx->iv, con.iv->iv, ivsize);
 292         }
 293
 294         while (size) {
 295                 struct scatterlist *sg;
 296                 unsigned long len = size;
 297                 int plen;
 298
 299                 if (ctx->merge) {
 300                         sgl = list_entry(ctx->tsgl.prev,
 301                                          struct skcipher_sg_list, list);
 302                         sg = sgl->sg + sgl->cur - 1;
 303                         len = min_t(unsigned long, len,
 304                                     PAGE_SIZE - sg->offset - sg->length);
 305
 306                         err = memcpy_fromiovec(page_address(sg_page(sg)) +
 307                                                sg->offset + sg->length,
 308                                                msg->msg_iov, len);
 309                         if (err)
 310                                 goto unlock;
 311
 312                         sg->length += len;
 313                         ctx->merge = (sg->offset + sg->length) &
 314                                      (PAGE_SIZE - 1);
 315
 316                         ctx->used += len;
 317                         copied += len;
 318                         size -= len;
 319                         continue;
 320                 }
 321
 322                 if (!skcipher_writable(sk)) {
 323                         err = skcipher_wait_for_wmem(sk, msg->msg_flags);
 324                         if (err)
 325                                 goto unlock;
 326                 }
 327
 328                 len = min_t(unsigned long, len, skcipher_sndbuf(sk));
 329
 330                 err = skcipher_alloc_sgl(sk);
 331                 if (err)
 332                         goto unlock;
 333
 334                 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
 335                 sg = sgl->sg;
 336                 do {
 337                         i = sgl->cur;
 338                         plen = min_t(int, len, PAGE_SIZE);
 339
 340                         sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
 341                         err = -ENOMEM;
 342                         if (!sg_page(sg + i))
 343                                 goto unlock;
 344
 345                         err = memcpy_fromiovec(page_address(sg_page(sg + i)),
 346                                                msg->msg_iov, plen);
 347                         if (err) {
 348                                 __free_page(sg_page(sg + i));
 349                                 sg_assign_page(sg + i, NULL);
 350                                 goto unlock;
 351                         }
 352
 353                         sg[i].length = plen;
 354                         len -= plen;
 355                         ctx->used += plen;
 356                         copied += plen;
 357                         size -= plen;
 358                         sgl->cur++;
 359                 } while (len && sgl->cur < MAX_SGL_ENTS);
 360
 361                 ctx->merge = plen & (PAGE_SIZE - 1);
 362         }
 363
 364         err = 0;
 365
 366         ctx->more = msg->msg_flags & MSG_MORE;
 367         if (!ctx->more && !list_empty(&ctx->tsgl))
 368                 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
 369
 370 unlock:
 371         skcipher_data_wakeup(sk);
 372         release_sock(sk);
 373
 374         return copied ?: err;
 375 }
 376
 377 static ssize_t skcipher_sendpage(struct socket *sock, struct page *page,
 378                                  int offset, size_t size, int flags)
 379 {
 380         struct sock *sk = sock->sk;
 381         struct alg_sock *ask = alg_sk(sk);
 382         struct skcipher_ctx *ctx = ask->private;
 383         struct skcipher_sg_list *sgl;
 384         int err = -EINVAL;
 385
 386         if (flags & MSG_SENDPAGE_NOTLAST)
 387                 flags |= MSG_MORE;
 388
 389         lock_sock(sk);
 390         if (!ctx->more && ctx->used)
 391                 goto unlock;
 392
 393         if (!size)
 394                 goto done;
 395
 396         if (!skcipher_writable(sk)) {
 397                 err = skcipher_wait_for_wmem(sk, flags);
 398                 if (err)
 399                         goto unlock;
 400         }
 401
 402         err = skcipher_alloc_sgl(sk);
 403         if (err)
 404                 goto unlock;
 405
 406         ctx->merge = 0;
 407         sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
 408
 409         get_page(page);
 410         sg_set_page(sgl->sg + sgl->cur, page, size, offset);
 411         sgl->cur++;
 412         ctx->used += size;
 413
 414 done:
 415         ctx->more = flags & MSG_MORE;
 416         if (!ctx->more && !list_empty(&ctx->tsgl))
 417                 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
 418
 419 unlock:
 420         skcipher_data_wakeup(sk);
 421         release_sock(sk);
 422
 423         return err ?: size;
 424 }
 425
 426 static int skcipher_recvmsg(struct kiocb *unused, struct socket *sock,
 427                             struct msghdr *msg, size_t ignored, int flags)
 428 {
 429         struct sock *sk = sock->sk;
 430         struct alg_sock *ask = alg_sk(sk);
 431         struct skcipher_ctx *ctx = ask->private;
 432         unsigned bs = crypto_ablkcipher_blocksize(crypto_ablkcipher_reqtfm(
 433                 &ctx->req));
 434         struct skcipher_sg_list *sgl;
 435         struct scatterlist *sg;
 436         unsigned long iovlen;
 437         struct iovec *iov;
 438         int err = -EAGAIN;
 439         int used;
 440         long copied = 0;
 441
 442         lock_sock(sk);
 443         for (iov = msg->msg_iov, iovlen = msg->msg_iovlen; iovlen > 0;
 444              iovlen--, iov++) {
 445                 unsigned long seglen = iov->iov_len;
 446                 char __user *from = iov->iov_base;
 447
 448                 while (seglen) {
 449                         sgl = list_first_entry(&ctx->tsgl,
 450                                                struct skcipher_sg_list, list);
 451                         sg = sgl->sg;
 452
 453                         while (!sg->length)
 454                                 sg++;
 455
 456                         used = ctx->used;
 457                         if (!used) {
 458                                 err = skcipher_wait_for_data(sk, flags);
 459                                 if (err)
 460                                         goto unlock;
 461                         }
 462
 463                         used = min_t(unsigned long, used, seglen);
 464
 465                         used = af_alg_make_sg(&ctx->rsgl, from, used, 1);
 466                         err = used;
 467                         if (err < 0)
 468                                 goto unlock;
 469
 470                         if (ctx->more || used < ctx->used)
 471                                 used -= used % bs;
 472
 473                         err = -EINVAL;
 474                         if (!used)
 475                                 goto free;
 476
 477                         ablkcipher_request_set_crypt(&ctx->req, sg,
 478                                                      ctx->rsgl.sg, used,
 479                                                      ctx->iv);
 480
 481                         err = af_alg_wait_for_completion(
 482                                 ctx->enc ?
 483                                         crypto_ablkcipher_encrypt(&ctx->req) :
 484                                         crypto_ablkcipher_decrypt(&ctx->req),
 485                                 &ctx->completion);
 486
 487 free:
 488                         af_alg_free_sg(&ctx->rsgl);
 489
 490                         if (err)
 491                                 goto unlock;
 492
 493                         copied += used;
 494                         from += used;
 495                         seglen -= used;
 496                         skcipher_pull_sgl(sk, used);
 497                 }
 498         }
 499
 500         err = 0;
 501
 502 unlock:
 503         skcipher_wmem_wakeup(sk);
 504         release_sock(sk);
 505
 506         return copied ?: err;
 507 }
 508
 509
 510 static unsigned int skcipher_poll(struct file *file, struct socket *sock,
 511                                   poll_table *wait)
 512 {
 513         struct sock *sk = sock->sk;
 514         struct alg_sock *ask = alg_sk(sk);
 515         struct skcipher_ctx *ctx = ask->private;
 516         unsigned int mask;
 517
 518         sock_poll_wait(file, sk_sleep(sk), wait);
 519         mask = 0;
 520
 521         if (ctx->used)
 522                 mask |= POLLIN | POLLRDNORM;
 523
 524         if (skcipher_writable(sk))
 525                 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
 526
 527         return mask;
 528 }
 529
 530 static struct proto_ops algif_skcipher_ops = {
 531         .family         =       PF_ALG,
 532
 533         .connect        =       sock_no_connect,
 534         .socketpair     =       sock_no_socketpair,
 535         .getname        =       sock_no_getname,
 536         .ioctl          =       sock_no_ioctl,
 537         .listen         =       sock_no_listen,
 538         .shutdown       =       sock_no_shutdown,
 539         .getsockopt     =       sock_no_getsockopt,
 540         .mmap           =       sock_no_mmap,
 541         .bind           =       sock_no_bind,
 542         .accept         =       sock_no_accept,
 543         .setsockopt     =       sock_no_setsockopt,
 544
 545         .release        =       af_alg_release,
 546         .sendmsg        =       skcipher_sendmsg,
 547         .sendpage       =       skcipher_sendpage,
 548         .recvmsg        =       skcipher_recvmsg,
 549         .poll           =       skcipher_poll,
 550 };
 551
 552 static int skcipher_check_key(struct socket *sock)
 553 {
 554         int err;
 555         struct sock *psk;
 556         struct alg_sock *pask;
 557         struct skcipher_tfm *tfm;
 558         struct sock *sk = sock->sk;
 559         struct alg_sock *ask = alg_sk(sk);
 560
 561         if (ask->refcnt)
 562                 return 0;
 563
 564         psk = ask->parent;
 565         pask = alg_sk(ask->parent);
 566         tfm = pask->private;
 567
 568         err = -ENOKEY;
 569         lock_sock(psk);
 570         if (!tfm->has_key)
 571                 goto unlock;
 572
 573         if (!pask->refcnt++)
 574                 sock_hold(psk);
 575
 576         ask->refcnt = 1;
 577         sock_put(psk);
 578
 579         err = 0;
 580
 581 unlock:
 582         release_sock(psk);
 583
 584         return err;
 585 }
 586
 587 static int skcipher_sendmsg_nokey(struct kiocb *unused, struct socket *sock,
 588                                   struct msghdr *msg, size_t size)
 589 {
 590         int err;
 591
 592         err = skcipher_check_key(sock);
 593         if (err)
 594                 return err;
 595
 596         return skcipher_sendmsg(unused, sock, msg, size);
 597 }
 598
 599 static ssize_t skcipher_sendpage_nokey(struct socket *sock, struct page *page,
 600                                        int offset, size_t size, int flags)
 601 {
 602         int err;
 603
 604         err = skcipher_check_key(sock);
 605         if (err)
 606                 return err;
 607
 608         return skcipher_sendpage(sock, page, offset, size, flags);
 609 }
 610
 611 static int skcipher_recvmsg_nokey(struct kiocb *unused, struct socket *sock,
 612                                   struct msghdr *msg, size_t ignored, int flags)
 613 {
 614         int err;
 615
 616         err = skcipher_check_key(sock);
 617         if (err)
 618                 return err;
 619
 620         return skcipher_recvmsg(unused, sock, msg, ignored, flags);
 621 }
 622
 623 static struct proto_ops algif_skcipher_ops_nokey = {
 624         .family         =       PF_ALG,
 625
 626         .connect        =       sock_no_connect,
 627         .socketpair     =       sock_no_socketpair,
 628         .getname        =       sock_no_getname,
 629         .ioctl          =       sock_no_ioctl,
 630         .listen         =       sock_no_listen,
 631         .shutdown       =       sock_no_shutdown,
 632         .getsockopt     =       sock_no_getsockopt,
 633         .mmap           =       sock_no_mmap,
 634         .bind           =       sock_no_bind,
 635         .accept         =       sock_no_accept,
 636         .setsockopt     =       sock_no_setsockopt,
 637
 638         .release        =       af_alg_release,
 639         .sendmsg        =       skcipher_sendmsg_nokey,
 640         .sendpage       =       skcipher_sendpage_nokey,
 641         .recvmsg        =       skcipher_recvmsg_nokey,
 642         .poll           =       skcipher_poll,
 643 };
 644
 645 static void *skcipher_bind(const char *name, u32 type, u32 mask)
 646 {
 647         struct skcipher_tfm *tfm;
 648         struct crypto_ablkcipher *skcipher;
 649
 650         tfm = kzalloc(sizeof(*tfm), GFP_KERNEL);
 651         if (!tfm)
 652                 return ERR_PTR(-ENOMEM);
 653
 654         skcipher = crypto_alloc_ablkcipher(name, type, mask);
 655         if (IS_ERR(skcipher)) {
 656                 kfree(tfm);
 657                 return ERR_CAST(skcipher);
 658         }
 659
 660         tfm->skcipher = skcipher;
 661
 662         return tfm;
 663 }
 664
 665 static void skcipher_release(void *private)
 666 {
 667         struct skcipher_tfm *tfm = private;
 668
 669         crypto_free_ablkcipher(tfm->skcipher);
 670         kfree(tfm);
 671 }
 672
 673 static int skcipher_setkey(void *private, const u8 *key, unsigned int keylen)
 674 {
 675         struct skcipher_tfm *tfm = private;
 676         int err;
 677
 678         err = crypto_ablkcipher_setkey(tfm->skcipher, key, keylen);
 679         tfm->has_key = !err;
 680
 681         return err;
 682 }
 683
 684 static void skcipher_sock_destruct_common(struct sock *sk)
 685 {
 686         struct alg_sock *ask = alg_sk(sk);
 687         struct skcipher_ctx *ctx = ask->private;
 688         struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(&ctx->req);
 689
 690         skcipher_free_sgl(sk);
 691         sock_kfree_s(sk, ctx->iv, crypto_ablkcipher_ivsize(tfm));
 692         sock_kfree_s(sk, ctx, ctx->len);
 693 }
 694
 695 static void skcipher_sock_destruct(struct sock *sk)
 696 {
 697         skcipher_sock_destruct_common(sk);
 698         af_alg_release_parent(sk);
 699 }
 700
 701 static void skcipher_release_parent_nokey(struct sock *sk)
 702 {
 703         struct alg_sock *ask = alg_sk(sk);
 704
 705         if (!ask->refcnt) {
 706                 sock_put(ask->parent);
 707                 return;
 708         }
 709
 710         af_alg_release_parent(sk);
 711 }
 712
 713 static void skcipher_sock_destruct_nokey(struct sock *sk)
 714 {
 715         skcipher_sock_destruct_common(sk);
 716         skcipher_release_parent_nokey(sk);
 717 }
 718
 719 static int skcipher_accept_parent_common(void *private, struct sock *sk)
 720 {
 721         struct skcipher_ctx *ctx;
 722         struct alg_sock *ask = alg_sk(sk);
 723         struct skcipher_tfm *tfm = private;
 724         struct crypto_ablkcipher *skcipher = tfm->skcipher;
 725         unsigned int len = sizeof(*ctx) + crypto_ablkcipher_reqsize(skcipher);
 726
 727         ctx = sock_kmalloc(sk, len, GFP_KERNEL);
 728         if (!ctx)
 729                 return -ENOMEM;
 730         ctx->iv = sock_kmalloc(sk, crypto_ablkcipher_ivsize(skcipher),
 731                                GFP_KERNEL);
 732         if (!ctx->iv) {
 733                 sock_kfree_s(sk, ctx, len);
 734                 return -ENOMEM;
 735         }
 736
 737         memset(ctx->iv, 0, crypto_ablkcipher_ivsize(skcipher));
 738
 739         INIT_LIST_HEAD(&ctx->tsgl);
 740         ctx->len = len;
 741         ctx->used = 0;
 742         ctx->more = 0;
 743         ctx->merge = 0;
 744         ctx->enc = 0;
 745         af_alg_init_completion(&ctx->completion);
 746
 747         ask->private = ctx;
 748
 749         ablkcipher_request_set_tfm(&ctx->req, skcipher);
 750         ablkcipher_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
 751                                       af_alg_complete, &ctx->completion);
 752
 753         sk->sk_destruct = skcipher_sock_destruct;
 754
 755         return 0;
 756 }
 757
 758 static int skcipher_accept_parent(void *private, struct sock *sk)
 759 {
 760         struct skcipher_tfm *tfm = private;
 761
 762         if (!tfm->has_key && crypto_ablkcipher_has_setkey(tfm->skcipher))
 763                 return -ENOKEY;
 764
 765         return skcipher_accept_parent_common(private, sk);
 766 }
 767
 768 static int skcipher_accept_parent_nokey(void *private, struct sock *sk)
 769 {
 770         int err;
 771
 772         err = skcipher_accept_parent_common(private, sk);
 773         if (err)
 774                 goto out;
 775
 776         sk->sk_destruct = skcipher_sock_destruct_nokey;
 777
 778 out:
 779         return err;
 780 }
 781
 782 static const struct af_alg_type algif_type_skcipher = {
 783         .bind           =       skcipher_bind,
 784         .release        =       skcipher_release,
 785         .setkey         =       skcipher_setkey,
 786         .accept         =       skcipher_accept_parent,
 787         .accept_nokey   =       skcipher_accept_parent_nokey,
 788         .ops            =       &algif_skcipher_ops,
 789         .ops_nokey      =       &algif_skcipher_ops_nokey,
 790         .name           =       "skcipher",
 791         .owner          =       THIS_MODULE
 792 };
 793
 794 static int __init algif_skcipher_init(void)
 795 {
 796         return af_alg_register_type(&algif_type_skcipher);
 797 }
 798
 799 static void __exit algif_skcipher_exit(void)
 800 {
 801         int err = af_alg_unregister_type(&algif_type_skcipher);
 802         BUG_ON(err);
 803 }
 804
 805 module_init(algif_skcipher_init);
 806 module_exit(algif_skcipher_exit);
 807 MODULE_LICENSE("GPL");