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_ctx {
  35         struct list_head tsgl;
  36         struct af_alg_sgl rsgl;
  37
  38         void *iv;
  39
  40         struct af_alg_completion completion;
  41
  42         atomic_t inflight;
  43         size_t used;
  44
  45         unsigned int len;
  46         bool more;
  47         bool merge;
  48         bool enc;
  49
  50         struct skcipher_request req;
  51 };
  52
  53 struct skcipher_async_rsgl {
  54         struct af_alg_sgl sgl;
  55         struct list_head list;
  56 };
  57
  58 struct skcipher_async_req {
  59         struct kiocb *iocb;
  60         struct skcipher_async_rsgl first_sgl;
  61         struct list_head list;
  62         struct scatterlist *tsg;
  63         char iv[];
  64 };
  65
  66 #define GET_SREQ(areq, ctx) (struct skcipher_async_req *)((char *)areq + \
  67         crypto_skcipher_reqsize(crypto_skcipher_reqtfm(&ctx->req)))
  68
  69 #define GET_REQ_SIZE(ctx) \
  70         crypto_skcipher_reqsize(crypto_skcipher_reqtfm(&ctx->req))
  71
  72 #define GET_IV_SIZE(ctx) \
  73         crypto_skcipher_ivsize(crypto_skcipher_reqtfm(&ctx->req))
  74
  75 #define MAX_SGL_ENTS ((4096 - sizeof(struct skcipher_sg_list)) / \
  76                       sizeof(struct scatterlist) - 1)
  77
  78 static void skcipher_free_async_sgls(struct skcipher_async_req *sreq)
  79 {
  80         struct skcipher_async_rsgl *rsgl, *tmp;
  81         struct scatterlist *sgl;
  82         struct scatterlist *sg;
  83         int i, n;
  84
  85         list_for_each_entry_safe(rsgl, tmp, &sreq->list, list) {
  86                 af_alg_free_sg(&rsgl->sgl);
  87                 if (rsgl != &sreq->first_sgl)
  88                         kfree(rsgl);
  89         }
  90         sgl = sreq->tsg;
  91         n = sg_nents(sgl);
  92         for_each_sg(sgl, sg, n, i)
  93                 put_page(sg_page(sg));
  94
  95         kfree(sreq->tsg);
  96 }
  97
  98 static void skcipher_async_cb(struct crypto_async_request *req, int err)
  99 {
 100         struct sock *sk = req->data;
 101         struct alg_sock *ask = alg_sk(sk);
 102         struct skcipher_ctx *ctx = ask->private;
 103         struct skcipher_async_req *sreq = GET_SREQ(req, ctx);
 104         struct kiocb *iocb = sreq->iocb;
 105
 106         atomic_dec(&ctx->inflight);
 107         skcipher_free_async_sgls(sreq);
 108         kfree(req);
 109         iocb->ki_complete(iocb, err, err);
 110 }
 111
 112 static inline int skcipher_sndbuf(struct sock *sk)
 113 {
 114         struct alg_sock *ask = alg_sk(sk);
 115         struct skcipher_ctx *ctx = ask->private;
 116
 117         return max_t(int, max_t(int, sk->sk_sndbuf & PAGE_MASK, PAGE_SIZE) -
 118                           ctx->used, 0);
 119 }
 120
 121 static inline bool skcipher_writable(struct sock *sk)
 122 {
 123         return PAGE_SIZE <= skcipher_sndbuf(sk);
 124 }
 125
 126 static int skcipher_alloc_sgl(struct sock *sk)
 127 {
 128         struct alg_sock *ask = alg_sk(sk);
 129         struct skcipher_ctx *ctx = ask->private;
 130         struct skcipher_sg_list *sgl;
 131         struct scatterlist *sg = NULL;
 132
 133         sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
 134         if (!list_empty(&ctx->tsgl))
 135                 sg = sgl->sg;
 136
 137         if (!sg || sgl->cur >= MAX_SGL_ENTS) {
 138                 sgl = sock_kmalloc(sk, sizeof(*sgl) +
 139                                        sizeof(sgl->sg[0]) * (MAX_SGL_ENTS + 1),
 140                                    GFP_KERNEL);
 141                 if (!sgl)
 142                         return -ENOMEM;
 143
 144                 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
 145                 sgl->cur = 0;
 146
 147                 if (sg)
 148                         sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
 149
 150                 list_add_tail(&sgl->list, &ctx->tsgl);
 151         }
 152
 153         return 0;
 154 }
 155
 156 static void skcipher_pull_sgl(struct sock *sk, size_t used, int put)
 157 {
 158         struct alg_sock *ask = alg_sk(sk);
 159         struct skcipher_ctx *ctx = ask->private;
 160         struct skcipher_sg_list *sgl;
 161         struct scatterlist *sg;
 162         int i;
 163
 164         while (!list_empty(&ctx->tsgl)) {
 165                 sgl = list_first_entry(&ctx->tsgl, struct skcipher_sg_list,
 166                                        list);
 167                 sg = sgl->sg;
 168
 169                 for (i = 0; i < sgl->cur; i++) {
 170                         size_t plen = min_t(size_t, used, sg[i].length);
 171
 172                         if (!sg_page(sg + i))
 173                                 continue;
 174
 175                         sg[i].length -= plen;
 176                         sg[i].offset += plen;
 177
 178                         used -= plen;
 179                         ctx->used -= plen;
 180
 181                         if (sg[i].length)
 182                                 return;
 183                         if (put)
 184                                 put_page(sg_page(sg + i));
 185                         sg_assign_page(sg + i, NULL);
 186                 }
 187
 188                 list_del(&sgl->list);
 189                 sock_kfree_s(sk, sgl,
 190                              sizeof(*sgl) + sizeof(sgl->sg[0]) *
 191                                             (MAX_SGL_ENTS + 1));
 192         }
 193
 194         if (!ctx->used)
 195                 ctx->merge = 0;
 196 }
 197
 198 static void skcipher_free_sgl(struct sock *sk)
 199 {
 200         struct alg_sock *ask = alg_sk(sk);
 201         struct skcipher_ctx *ctx = ask->private;
 202
 203         skcipher_pull_sgl(sk, ctx->used, 1);
 204 }
 205
 206 static int skcipher_wait_for_wmem(struct sock *sk, unsigned flags)
 207 {
 208         long timeout;
 209         DEFINE_WAIT(wait);
 210         int err = -ERESTARTSYS;
 211
 212         if (flags & MSG_DONTWAIT)
 213                 return -EAGAIN;
 214
 215         sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 216
 217         for (;;) {
 218                 if (signal_pending(current))
 219                         break;
 220                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 221                 timeout = MAX_SCHEDULE_TIMEOUT;
 222                 if (sk_wait_event(sk, &timeout, skcipher_writable(sk))) {
 223                         err = 0;
 224                         break;
 225                 }
 226         }
 227         finish_wait(sk_sleep(sk), &wait);
 228
 229         return err;
 230 }
 231
 232 static void skcipher_wmem_wakeup(struct sock *sk)
 233 {
 234         struct socket_wq *wq;
 235
 236         if (!skcipher_writable(sk))
 237                 return;
 238
 239         rcu_read_lock();
 240         wq = rcu_dereference(sk->sk_wq);
 241         if (skwq_has_sleeper(wq))
 242                 wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
 243                                                            POLLRDNORM |
 244                                                            POLLRDBAND);
 245         sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
 246         rcu_read_unlock();
 247 }
 248
 249 static int skcipher_wait_for_data(struct sock *sk, unsigned flags)
 250 {
 251         struct alg_sock *ask = alg_sk(sk);
 252         struct skcipher_ctx *ctx = ask->private;
 253         long timeout;
 254         DEFINE_WAIT(wait);
 255         int err = -ERESTARTSYS;
 256
 257         if (flags & MSG_DONTWAIT) {
 258                 return -EAGAIN;
 259         }
 260
 261         sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
 262
 263         for (;;) {
 264                 if (signal_pending(current))
 265                         break;
 266                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 267                 timeout = MAX_SCHEDULE_TIMEOUT;
 268                 if (sk_wait_event(sk, &timeout, ctx->used)) {
 269                         err = 0;
 270                         break;
 271                 }
 272         }
 273         finish_wait(sk_sleep(sk), &wait);
 274
 275         sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
 276
 277         return err;
 278 }
 279
 280 static void skcipher_data_wakeup(struct sock *sk)
 281 {
 282         struct alg_sock *ask = alg_sk(sk);
 283         struct skcipher_ctx *ctx = ask->private;
 284         struct socket_wq *wq;
 285
 286         if (!ctx->used)
 287                 return;
 288
 289         rcu_read_lock();
 290         wq = rcu_dereference(sk->sk_wq);
 291         if (skwq_has_sleeper(wq))
 292                 wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
 293                                                            POLLRDNORM |
 294                                                            POLLRDBAND);
 295         sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
 296         rcu_read_unlock();
 297 }
 298
 299 static int skcipher_sendmsg(struct socket *sock, struct msghdr *msg,
 300                             size_t size)
 301 {
 302         struct sock *sk = sock->sk;
 303         struct alg_sock *ask = alg_sk(sk);
 304         struct skcipher_ctx *ctx = ask->private;
 305         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(&ctx->req);
 306         unsigned ivsize = crypto_skcipher_ivsize(tfm);
 307         struct skcipher_sg_list *sgl;
 308         struct af_alg_control con = {};
 309         long copied = 0;
 310         bool enc = 0;
 311         bool init = 0;
 312         int err;
 313         int i;
 314
 315         if (msg->msg_controllen) {
 316                 err = af_alg_cmsg_send(msg, &con);
 317                 if (err)
 318                         return err;
 319
 320                 init = 1;
 321                 switch (con.op) {
 322                 case ALG_OP_ENCRYPT:
 323                         enc = 1;
 324                         break;
 325                 case ALG_OP_DECRYPT:
 326                         enc = 0;
 327                         break;
 328                 default:
 329                         return -EINVAL;
 330                 }
 331
 332                 if (con.iv && con.iv->ivlen != ivsize)
 333                         return -EINVAL;
 334         }
 335
 336         err = -EINVAL;
 337
 338         lock_sock(sk);
 339         if (!ctx->more && ctx->used)
 340                 goto unlock;
 341
 342         if (init) {
 343                 ctx->enc = enc;
 344                 if (con.iv)
 345                         memcpy(ctx->iv, con.iv->iv, ivsize);
 346         }
 347
 348         while (size) {
 349                 struct scatterlist *sg;
 350                 unsigned long len = size;
 351                 size_t plen;
 352
 353                 if (ctx->merge) {
 354                         sgl = list_entry(ctx->tsgl.prev,
 355                                          struct skcipher_sg_list, list);
 356                         sg = sgl->sg + sgl->cur - 1;
 357                         len = min_t(unsigned long, len,
 358                                     PAGE_SIZE - sg->offset - sg->length);
 359
 360                         err = memcpy_from_msg(page_address(sg_page(sg)) +
 361                                               sg->offset + sg->length,
 362                                               msg, len);
 363                         if (err)
 364                                 goto unlock;
 365
 366                         sg->length += len;
 367                         ctx->merge = (sg->offset + sg->length) &
 368                                      (PAGE_SIZE - 1);
 369
 370                         ctx->used += len;
 371                         copied += len;
 372                         size -= len;
 373                         continue;
 374                 }
 375
 376                 if (!skcipher_writable(sk)) {
 377                         err = skcipher_wait_for_wmem(sk, msg->msg_flags);
 378                         if (err)
 379                                 goto unlock;
 380                 }
 381
 382                 len = min_t(unsigned long, len, skcipher_sndbuf(sk));
 383
 384                 err = skcipher_alloc_sgl(sk);
 385                 if (err)
 386                         goto unlock;
 387
 388                 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
 389                 sg = sgl->sg;
 390                 sg_unmark_end(sg + sgl->cur);
 391                 do {
 392                         i = sgl->cur;
 393                         plen = min_t(size_t, len, PAGE_SIZE);
 394
 395                         sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
 396                         err = -ENOMEM;
 397                         if (!sg_page(sg + i))
 398                                 goto unlock;
 399
 400                         err = memcpy_from_msg(page_address(sg_page(sg + i)),
 401                                               msg, plen);
 402                         if (err) {
 403                                 __free_page(sg_page(sg + i));
 404                                 sg_assign_page(sg + i, NULL);
 405                                 goto unlock;
 406                         }
 407
 408                         sg[i].length = plen;
 409                         len -= plen;
 410                         ctx->used += plen;
 411                         copied += plen;
 412                         size -= plen;
 413                         sgl->cur++;
 414                 } while (len && sgl->cur < MAX_SGL_ENTS);
 415
 416                 if (!size)
 417                         sg_mark_end(sg + sgl->cur - 1);
 418
 419                 ctx->merge = plen & (PAGE_SIZE - 1);
 420         }
 421
 422         err = 0;
 423
 424         ctx->more = msg->msg_flags & MSG_MORE;
 425
 426 unlock:
 427         skcipher_data_wakeup(sk);
 428         release_sock(sk);
 429
 430         return copied ?: err;
 431 }
 432
 433 static ssize_t skcipher_sendpage(struct socket *sock, struct page *page,
 434                                  int offset, size_t size, int flags)
 435 {
 436         struct sock *sk = sock->sk;
 437         struct alg_sock *ask = alg_sk(sk);
 438         struct skcipher_ctx *ctx = ask->private;
 439         struct skcipher_sg_list *sgl;
 440         int err = -EINVAL;
 441
 442         if (flags & MSG_SENDPAGE_NOTLAST)
 443                 flags |= MSG_MORE;
 444
 445         lock_sock(sk);
 446         if (!ctx->more && ctx->used)
 447                 goto unlock;
 448
 449         if (!size)
 450                 goto done;
 451
 452         if (!skcipher_writable(sk)) {
 453                 err = skcipher_wait_for_wmem(sk, flags);
 454                 if (err)
 455                         goto unlock;
 456         }
 457
 458         err = skcipher_alloc_sgl(sk);
 459         if (err)
 460                 goto unlock;
 461
 462         ctx->merge = 0;
 463         sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
 464
 465         if (sgl->cur)
 466                 sg_unmark_end(sgl->sg + sgl->cur - 1);
 467
 468         sg_mark_end(sgl->sg + sgl->cur);
 469         get_page(page);
 470         sg_set_page(sgl->sg + sgl->cur, page, size, offset);
 471         sgl->cur++;
 472         ctx->used += size;
 473
 474 done:
 475         ctx->more = flags & MSG_MORE;
 476
 477 unlock:
 478         skcipher_data_wakeup(sk);
 479         release_sock(sk);
 480
 481         return err ?: size;
 482 }
 483
 484 static int skcipher_all_sg_nents(struct skcipher_ctx *ctx)
 485 {
 486         struct skcipher_sg_list *sgl;
 487         struct scatterlist *sg;
 488         int nents = 0;
 489
 490         list_for_each_entry(sgl, &ctx->tsgl, list) {
 491                 sg = sgl->sg;
 492
 493                 while (!sg->length)
 494                         sg++;
 495
 496                 nents += sg_nents(sg);
 497         }
 498         return nents;
 499 }
 500
 501 static int skcipher_recvmsg_async(struct socket *sock, struct msghdr *msg,
 502                                   int flags)
 503 {
 504         struct sock *sk = sock->sk;
 505         struct alg_sock *ask = alg_sk(sk);
 506         struct skcipher_ctx *ctx = ask->private;
 507         struct skcipher_sg_list *sgl;
 508         struct scatterlist *sg;
 509         struct skcipher_async_req *sreq;
 510         struct skcipher_request *req;
 511         struct skcipher_async_rsgl *last_rsgl = NULL;
 512         unsigned int txbufs = 0, len = 0, tx_nents = skcipher_all_sg_nents(ctx);
 513         unsigned int reqlen = sizeof(struct skcipher_async_req) +
 514                                 GET_REQ_SIZE(ctx) + GET_IV_SIZE(ctx);
 515         int err = -ENOMEM;
 516         bool mark = false;
 517
 518         lock_sock(sk);
 519         req = kmalloc(reqlen, GFP_KERNEL);
 520         if (unlikely(!req))
 521                 goto unlock;
 522
 523         sreq = GET_SREQ(req, ctx);
 524         sreq->iocb = msg->msg_iocb;
 525         memset(&sreq->first_sgl, '\0', sizeof(struct skcipher_async_rsgl));
 526         INIT_LIST_HEAD(&sreq->list);
 527         sreq->tsg = kcalloc(tx_nents, sizeof(*sg), GFP_KERNEL);
 528         if (unlikely(!sreq->tsg)) {
 529                 kfree(req);
 530                 goto unlock;
 531         }
 532         sg_init_table(sreq->tsg, tx_nents);
 533         memcpy(sreq->iv, ctx->iv, GET_IV_SIZE(ctx));
 534         skcipher_request_set_tfm(req, crypto_skcipher_reqtfm(&ctx->req));
 535         skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
 536                                       skcipher_async_cb, sk);
 537
 538         while (iov_iter_count(&msg->msg_iter)) {
 539                 struct skcipher_async_rsgl *rsgl;
 540                 int used;
 541
 542                 if (!ctx->used) {
 543                         err = skcipher_wait_for_data(sk, flags);
 544                         if (err)
 545                                 goto free;
 546                 }
 547                 sgl = list_first_entry(&ctx->tsgl,
 548                                        struct skcipher_sg_list, list);
 549                 sg = sgl->sg;
 550
 551                 while (!sg->length)
 552                         sg++;
 553
 554                 used = min_t(unsigned long, ctx->used,
 555                              iov_iter_count(&msg->msg_iter));
 556                 used = min_t(unsigned long, used, sg->length);
 557
 558                 if (txbufs == tx_nents) {
 559                         struct scatterlist *tmp;
 560                         int x;
 561                         /* Ran out of tx slots in async request
 562                          * need to expand */
 563                         tmp = kcalloc(tx_nents * 2, sizeof(*tmp),
 564                                       GFP_KERNEL);
 565                         if (!tmp)
 566                                 goto free;
 567
 568                         sg_init_table(tmp, tx_nents * 2);
 569                         for (x = 0; x < tx_nents; x++)
 570                                 sg_set_page(&tmp[x], sg_page(&sreq->tsg[x]),
 571                                             sreq->tsg[x].length,
 572                                             sreq->tsg[x].offset);
 573                         kfree(sreq->tsg);
 574                         sreq->tsg = tmp;
 575                         tx_nents *= 2;
 576                         mark = true;
 577                 }
 578                 /* Need to take over the tx sgl from ctx
 579                  * to the asynch req - these sgls will be freed later */
 580                 sg_set_page(sreq->tsg + txbufs++, sg_page(sg), sg->length,
 581                             sg->offset);
 582
 583                 if (list_empty(&sreq->list)) {
 584                         rsgl = &sreq->first_sgl;
 585                         list_add_tail(&rsgl->list, &sreq->list);
 586                 } else {
 587                         rsgl = kmalloc(sizeof(*rsgl), GFP_KERNEL);
 588                         if (!rsgl) {
 589                                 err = -ENOMEM;
 590                                 goto free;
 591                         }
 592                         list_add_tail(&rsgl->list, &sreq->list);
 593                 }
 594
 595                 used = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, used);
 596                 err = used;
 597                 if (used < 0)
 598                         goto free;
 599                 if (last_rsgl)
 600                         af_alg_link_sg(&last_rsgl->sgl, &rsgl->sgl);
 601
 602                 last_rsgl = rsgl;
 603                 len += used;
 604                 skcipher_pull_sgl(sk, used, 0);
 605                 iov_iter_advance(&msg->msg_iter, used);
 606         }
 607
 608         if (mark)
 609                 sg_mark_end(sreq->tsg + txbufs - 1);
 610
 611         skcipher_request_set_crypt(req, sreq->tsg, sreq->first_sgl.sgl.sg,
 612                                    len, sreq->iv);
 613         err = ctx->enc ? crypto_skcipher_encrypt(req) :
 614                          crypto_skcipher_decrypt(req);
 615         if (err == -EINPROGRESS) {
 616                 atomic_inc(&ctx->inflight);
 617                 err = -EIOCBQUEUED;
 618                 goto unlock;
 619         }
 620 free:
 621         skcipher_free_async_sgls(sreq);
 622         kfree(req);
 623 unlock:
 624         skcipher_wmem_wakeup(sk);
 625         release_sock(sk);
 626         return err;
 627 }
 628
 629 static int skcipher_recvmsg_sync(struct socket *sock, struct msghdr *msg,
 630                                  int flags)
 631 {
 632         struct sock *sk = sock->sk;
 633         struct alg_sock *ask = alg_sk(sk);
 634         struct skcipher_ctx *ctx = ask->private;
 635         unsigned bs = crypto_skcipher_blocksize(crypto_skcipher_reqtfm(
 636                 &ctx->req));
 637         struct skcipher_sg_list *sgl;
 638         struct scatterlist *sg;
 639         int err = -EAGAIN;
 640         int used;
 641         long copied = 0;
 642
 643         lock_sock(sk);
 644         while (msg_data_left(msg)) {
 645                 sgl = list_first_entry(&ctx->tsgl,
 646                                        struct skcipher_sg_list, list);
 647                 sg = sgl->sg;
 648
 649                 while (!sg->length)
 650                         sg++;
 651
 652                 if (!ctx->used) {
 653                         err = skcipher_wait_for_data(sk, flags);
 654                         if (err)
 655                                 goto unlock;
 656                 }
 657
 658                 used = min_t(unsigned long, ctx->used, msg_data_left(msg));
 659
 660                 used = af_alg_make_sg(&ctx->rsgl, &msg->msg_iter, used);
 661                 err = used;
 662                 if (err < 0)
 663                         goto unlock;
 664
 665                 if (ctx->more || used < ctx->used)
 666                         used -= used % bs;
 667
 668                 err = -EINVAL;
 669                 if (!used)
 670                         goto free;
 671
 672                 skcipher_request_set_crypt(&ctx->req, sg, ctx->rsgl.sg, used,
 673                                            ctx->iv);
 674
 675                 err = af_alg_wait_for_completion(
 676                                 ctx->enc ?
 677                                         crypto_skcipher_encrypt(&ctx->req) :
 678                                         crypto_skcipher_decrypt(&ctx->req),
 679                                 &ctx->completion);
 680
 681 free:
 682                 af_alg_free_sg(&ctx->rsgl);
 683
 684                 if (err)
 685                         goto unlock;
 686
 687                 copied += used;
 688                 skcipher_pull_sgl(sk, used, 1);
 689                 iov_iter_advance(&msg->msg_iter, used);
 690         }
 691
 692         err = 0;
 693
 694 unlock:
 695         skcipher_wmem_wakeup(sk);
 696         release_sock(sk);
 697
 698         return copied ?: err;
 699 }
 700
 701 static int skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
 702                             size_t ignored, int flags)
 703 {
 704         return (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) ?
 705                 skcipher_recvmsg_async(sock, msg, flags) :
 706                 skcipher_recvmsg_sync(sock, msg, flags);
 707 }
 708
 709 static unsigned int skcipher_poll(struct file *file, struct socket *sock,
 710                                   poll_table *wait)
 711 {
 712         struct sock *sk = sock->sk;
 713         struct alg_sock *ask = alg_sk(sk);
 714         struct skcipher_ctx *ctx = ask->private;
 715         unsigned int mask;
 716
 717         sock_poll_wait(file, sk_sleep(sk), wait);
 718         mask = 0;
 719
 720         if (ctx->used)
 721                 mask |= POLLIN | POLLRDNORM;
 722
 723         if (skcipher_writable(sk))
 724                 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
 725
 726         return mask;
 727 }
 728
 729 static struct proto_ops algif_skcipher_ops = {
 730         .family         =       PF_ALG,
 731
 732         .connect        =       sock_no_connect,
 733         .socketpair     =       sock_no_socketpair,
 734         .getname        =       sock_no_getname,
 735         .ioctl          =       sock_no_ioctl,
 736         .listen         =       sock_no_listen,
 737         .shutdown       =       sock_no_shutdown,
 738         .getsockopt     =       sock_no_getsockopt,
 739         .mmap           =       sock_no_mmap,
 740         .bind           =       sock_no_bind,
 741         .accept         =       sock_no_accept,
 742         .setsockopt     =       sock_no_setsockopt,
 743
 744         .release        =       af_alg_release,
 745         .sendmsg        =       skcipher_sendmsg,
 746         .sendpage       =       skcipher_sendpage,
 747         .recvmsg        =       skcipher_recvmsg,
 748         .poll           =       skcipher_poll,
 749 };
 750
 751 static void *skcipher_bind(const char *name, u32 type, u32 mask)
 752 {
 753         return crypto_alloc_skcipher(name, type, mask);
 754 }
 755
 756 static void skcipher_release(void *private)
 757 {
 758         crypto_free_skcipher(private);
 759 }
 760
 761 static int skcipher_setkey(void *private, const u8 *key, unsigned int keylen)
 762 {
 763         return crypto_skcipher_setkey(private, key, keylen);
 764 }
 765
 766 static void skcipher_wait(struct sock *sk)
 767 {
 768         struct alg_sock *ask = alg_sk(sk);
 769         struct skcipher_ctx *ctx = ask->private;
 770         int ctr = 0;
 771
 772         while (atomic_read(&ctx->inflight) && ctr++ < 100)
 773                 msleep(100);
 774 }
 775
 776 static void skcipher_sock_destruct(struct sock *sk)
 777 {
 778         struct alg_sock *ask = alg_sk(sk);
 779         struct skcipher_ctx *ctx = ask->private;
 780         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(&ctx->req);
 781
 782         if (atomic_read(&ctx->inflight))
 783                 skcipher_wait(sk);
 784
 785         skcipher_free_sgl(sk);
 786         sock_kzfree_s(sk, ctx->iv, crypto_skcipher_ivsize(tfm));
 787         sock_kfree_s(sk, ctx, ctx->len);
 788         af_alg_release_parent(sk);
 789 }
 790
 791 static int skcipher_accept_parent(void *private, struct sock *sk)
 792 {
 793         struct skcipher_ctx *ctx;
 794         struct alg_sock *ask = alg_sk(sk);
 795         unsigned int len = sizeof(*ctx) + crypto_skcipher_reqsize(private);
 796
 797         ctx = sock_kmalloc(sk, len, GFP_KERNEL);
 798         if (!ctx)
 799                 return -ENOMEM;
 800
 801         ctx->iv = sock_kmalloc(sk, crypto_skcipher_ivsize(private),
 802                                GFP_KERNEL);
 803         if (!ctx->iv) {
 804                 sock_kfree_s(sk, ctx, len);
 805                 return -ENOMEM;
 806         }
 807
 808         memset(ctx->iv, 0, crypto_skcipher_ivsize(private));
 809
 810         INIT_LIST_HEAD(&ctx->tsgl);
 811         ctx->len = len;
 812         ctx->used = 0;
 813         ctx->more = 0;
 814         ctx->merge = 0;
 815         ctx->enc = 0;
 816         atomic_set(&ctx->inflight, 0);
 817         af_alg_init_completion(&ctx->completion);
 818
 819         ask->private = ctx;
 820
 821         skcipher_request_set_tfm(&ctx->req, private);
 822         skcipher_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
 823                                       af_alg_complete, &ctx->completion);
 824
 825         sk->sk_destruct = skcipher_sock_destruct;
 826
 827         return 0;
 828 }
 829
 830 static const struct af_alg_type algif_type_skcipher = {
 831         .bind           =       skcipher_bind,
 832         .release        =       skcipher_release,
 833         .setkey         =       skcipher_setkey,
 834         .accept         =       skcipher_accept_parent,
 835         .ops            =       &algif_skcipher_ops,
 836         .name           =       "skcipher",
 837         .owner          =       THIS_MODULE
 838 };
 839
 840 static int __init algif_skcipher_init(void)
 841 {
 842         return af_alg_register_type(&algif_type_skcipher);
 843 }
 844
 845 static void __exit algif_skcipher_exit(void)
 846 {
 847         int err = af_alg_unregister_type(&algif_type_skcipher);
 848         BUG_ON(err);
 849 }
 850
 851 module_init(algif_skcipher_init);
 852 module_exit(algif_skcipher_exit);
 853 MODULE_LICENSE("GPL");