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_skcipher *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         atomic_t inflight;
  48         size_t used;
  49
  50         unsigned int len;
  51         bool more;
  52         bool merge;
  53         bool enc;
  54
  55         struct skcipher_request req;
  56 };
  57
  58 struct skcipher_async_rsgl {
  59         struct af_alg_sgl sgl;
  60         struct list_head list;
  61 };
  62
  63 struct skcipher_async_req {
  64         struct kiocb *iocb;
  65         struct skcipher_async_rsgl first_sgl;
  66         struct list_head list;
  67         struct scatterlist *tsg;
  68         char iv[];
  69 };
  70
  71 #define GET_SREQ(areq, ctx) (struct skcipher_async_req *)((char *)areq + \
  72         crypto_skcipher_reqsize(crypto_skcipher_reqtfm(&ctx->req)))
  73
  74 #define GET_REQ_SIZE(ctx) \
  75         crypto_skcipher_reqsize(crypto_skcipher_reqtfm(&ctx->req))
  76
  77 #define GET_IV_SIZE(ctx) \
  78         crypto_skcipher_ivsize(crypto_skcipher_reqtfm(&ctx->req))
  79
  80 #define MAX_SGL_ENTS ((4096 - sizeof(struct skcipher_sg_list)) / \
  81                       sizeof(struct scatterlist) - 1)
  82
  83 static void skcipher_free_async_sgls(struct skcipher_async_req *sreq)
  84 {
  85         struct skcipher_async_rsgl *rsgl, *tmp;
  86         struct scatterlist *sgl;
  87         struct scatterlist *sg;
  88         int i, n;
  89
  90         list_for_each_entry_safe(rsgl, tmp, &sreq->list, list) {
  91                 af_alg_free_sg(&rsgl->sgl);
  92                 if (rsgl != &sreq->first_sgl)
  93                         kfree(rsgl);
  94         }
  95         sgl = sreq->tsg;
  96         n = sg_nents(sgl);
  97         for_each_sg(sgl, sg, n, i)
  98                 put_page(sg_page(sg));
  99
 100         kfree(sreq->tsg);
 101 }
 102
 103 static void skcipher_async_cb(struct crypto_async_request *req, int err)
 104 {
 105         struct sock *sk = req->data;
 106         struct alg_sock *ask = alg_sk(sk);
 107         struct skcipher_ctx *ctx = ask->private;
 108         struct skcipher_async_req *sreq = GET_SREQ(req, ctx);
 109         struct kiocb *iocb = sreq->iocb;
 110
 111         atomic_dec(&ctx->inflight);
 112         skcipher_free_async_sgls(sreq);
 113         kfree(req);
 114         iocb->ki_complete(iocb, err, err);
 115 }
 116
 117 static inline int skcipher_sndbuf(struct sock *sk)
 118 {
 119         struct alg_sock *ask = alg_sk(sk);
 120         struct skcipher_ctx *ctx = ask->private;
 121
 122         return max_t(int, max_t(int, sk->sk_sndbuf & PAGE_MASK, PAGE_SIZE) -
 123                           ctx->used, 0);
 124 }
 125
 126 static inline bool skcipher_writable(struct sock *sk)
 127 {
 128         return PAGE_SIZE <= skcipher_sndbuf(sk);
 129 }
 130
 131 static int skcipher_alloc_sgl(struct sock *sk)
 132 {
 133         struct alg_sock *ask = alg_sk(sk);
 134         struct skcipher_ctx *ctx = ask->private;
 135         struct skcipher_sg_list *sgl;
 136         struct scatterlist *sg = NULL;
 137
 138         sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
 139         if (!list_empty(&ctx->tsgl))
 140                 sg = sgl->sg;
 141
 142         if (!sg || sgl->cur >= MAX_SGL_ENTS) {
 143                 sgl = sock_kmalloc(sk, sizeof(*sgl) +
 144                                        sizeof(sgl->sg[0]) * (MAX_SGL_ENTS + 1),
 145                                    GFP_KERNEL);
 146                 if (!sgl)
 147                         return -ENOMEM;
 148
 149                 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
 150                 sgl->cur = 0;
 151
 152                 if (sg)
 153                         sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
 154
 155                 list_add_tail(&sgl->list, &ctx->tsgl);
 156         }
 157
 158         return 0;
 159 }
 160
 161 static void skcipher_pull_sgl(struct sock *sk, size_t used, int put)
 162 {
 163         struct alg_sock *ask = alg_sk(sk);
 164         struct skcipher_ctx *ctx = ask->private;
 165         struct skcipher_sg_list *sgl;
 166         struct scatterlist *sg;
 167         int i;
 168
 169         while (!list_empty(&ctx->tsgl)) {
 170                 sgl = list_first_entry(&ctx->tsgl, struct skcipher_sg_list,
 171                                        list);
 172                 sg = sgl->sg;
 173
 174                 for (i = 0; i < sgl->cur; i++) {
 175                         size_t plen = min_t(size_t, used, sg[i].length);
 176
 177                         if (!sg_page(sg + i))
 178                                 continue;
 179
 180                         sg[i].length -= plen;
 181                         sg[i].offset += plen;
 182
 183                         used -= plen;
 184                         ctx->used -= plen;
 185
 186                         if (sg[i].length)
 187                                 return;
 188                         if (put)
 189                                 put_page(sg_page(sg + i));
 190                         sg_assign_page(sg + i, NULL);
 191                 }
 192
 193                 list_del(&sgl->list);
 194                 sock_kfree_s(sk, sgl,
 195                              sizeof(*sgl) + sizeof(sgl->sg[0]) *
 196                                             (MAX_SGL_ENTS + 1));
 197         }
 198
 199         if (!ctx->used)
 200                 ctx->merge = 0;
 201 }
 202
 203 static void skcipher_free_sgl(struct sock *sk)
 204 {
 205         struct alg_sock *ask = alg_sk(sk);
 206         struct skcipher_ctx *ctx = ask->private;
 207
 208         skcipher_pull_sgl(sk, ctx->used, 1);
 209 }
 210
 211 static int skcipher_wait_for_wmem(struct sock *sk, unsigned flags)
 212 {
 213         long timeout;
 214         DEFINE_WAIT(wait);
 215         int err = -ERESTARTSYS;
 216
 217         if (flags & MSG_DONTWAIT)
 218                 return -EAGAIN;
 219
 220         sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 221
 222         for (;;) {
 223                 if (signal_pending(current))
 224                         break;
 225                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 226                 timeout = MAX_SCHEDULE_TIMEOUT;
 227                 if (sk_wait_event(sk, &timeout, skcipher_writable(sk))) {
 228                         err = 0;
 229                         break;
 230                 }
 231         }
 232         finish_wait(sk_sleep(sk), &wait);
 233
 234         return err;
 235 }
 236
 237 static void skcipher_wmem_wakeup(struct sock *sk)
 238 {
 239         struct socket_wq *wq;
 240
 241         if (!skcipher_writable(sk))
 242                 return;
 243
 244         rcu_read_lock();
 245         wq = rcu_dereference(sk->sk_wq);
 246         if (skwq_has_sleeper(wq))
 247                 wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
 248                                                            POLLRDNORM |
 249                                                            POLLRDBAND);
 250         sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
 251         rcu_read_unlock();
 252 }
 253
 254 static int skcipher_wait_for_data(struct sock *sk, unsigned flags)
 255 {
 256         struct alg_sock *ask = alg_sk(sk);
 257         struct skcipher_ctx *ctx = ask->private;
 258         long timeout;
 259         DEFINE_WAIT(wait);
 260         int err = -ERESTARTSYS;
 261
 262         if (flags & MSG_DONTWAIT) {
 263                 return -EAGAIN;
 264         }
 265
 266         sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
 267
 268         for (;;) {
 269                 if (signal_pending(current))
 270                         break;
 271                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 272                 timeout = MAX_SCHEDULE_TIMEOUT;
 273                 if (sk_wait_event(sk, &timeout, ctx->used)) {
 274                         err = 0;
 275                         break;
 276                 }
 277         }
 278         finish_wait(sk_sleep(sk), &wait);
 279
 280         sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
 281
 282         return err;
 283 }
 284
 285 static void skcipher_data_wakeup(struct sock *sk)
 286 {
 287         struct alg_sock *ask = alg_sk(sk);
 288         struct skcipher_ctx *ctx = ask->private;
 289         struct socket_wq *wq;
 290
 291         if (!ctx->used)
 292                 return;
 293
 294         rcu_read_lock();
 295         wq = rcu_dereference(sk->sk_wq);
 296         if (skwq_has_sleeper(wq))
 297                 wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
 298                                                            POLLRDNORM |
 299                                                            POLLRDBAND);
 300         sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
 301         rcu_read_unlock();
 302 }
 303
 304 static int skcipher_sendmsg(struct socket *sock, struct msghdr *msg,
 305                             size_t size)
 306 {
 307         struct sock *sk = sock->sk;
 308         struct alg_sock *ask = alg_sk(sk);
 309         struct skcipher_ctx *ctx = ask->private;
 310         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(&ctx->req);
 311         unsigned ivsize = crypto_skcipher_ivsize(tfm);
 312         struct skcipher_sg_list *sgl;
 313         struct af_alg_control con = {};
 314         long copied = 0;
 315         bool enc = 0;
 316         bool init = 0;
 317         int err;
 318         int i;
 319
 320         if (msg->msg_controllen) {
 321                 err = af_alg_cmsg_send(msg, &con);
 322                 if (err)
 323                         return err;
 324
 325                 init = 1;
 326                 switch (con.op) {
 327                 case ALG_OP_ENCRYPT:
 328                         enc = 1;
 329                         break;
 330                 case ALG_OP_DECRYPT:
 331                         enc = 0;
 332                         break;
 333                 default:
 334                         return -EINVAL;
 335                 }
 336
 337                 if (con.iv && con.iv->ivlen != ivsize)
 338                         return -EINVAL;
 339         }
 340
 341         err = -EINVAL;
 342
 343         lock_sock(sk);
 344         if (!ctx->more && ctx->used)
 345                 goto unlock;
 346
 347         if (init) {
 348                 ctx->enc = enc;
 349                 if (con.iv)
 350                         memcpy(ctx->iv, con.iv->iv, ivsize);
 351         }
 352
 353         while (size) {
 354                 struct scatterlist *sg;
 355                 unsigned long len = size;
 356                 size_t plen;
 357
 358                 if (ctx->merge) {
 359                         sgl = list_entry(ctx->tsgl.prev,
 360                                          struct skcipher_sg_list, list);
 361                         sg = sgl->sg + sgl->cur - 1;
 362                         len = min_t(unsigned long, len,
 363                                     PAGE_SIZE - sg->offset - sg->length);
 364
 365                         err = memcpy_from_msg(page_address(sg_page(sg)) +
 366                                               sg->offset + sg->length,
 367                                               msg, len);
 368                         if (err)
 369                                 goto unlock;
 370
 371                         sg->length += len;
 372                         ctx->merge = (sg->offset + sg->length) &
 373                                      (PAGE_SIZE - 1);
 374
 375                         ctx->used += len;
 376                         copied += len;
 377                         size -= len;
 378                         continue;
 379                 }
 380
 381                 if (!skcipher_writable(sk)) {
 382                         err = skcipher_wait_for_wmem(sk, msg->msg_flags);
 383                         if (err)
 384                                 goto unlock;
 385                 }
 386
 387                 len = min_t(unsigned long, len, skcipher_sndbuf(sk));
 388
 389                 err = skcipher_alloc_sgl(sk);
 390                 if (err)
 391                         goto unlock;
 392
 393                 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
 394                 sg = sgl->sg;
 395                 if (sgl->cur)
 396                         sg_unmark_end(sg + sgl->cur - 1);
 397                 do {
 398                         i = sgl->cur;
 399                         plen = min_t(size_t, len, PAGE_SIZE);
 400
 401                         sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
 402                         err = -ENOMEM;
 403                         if (!sg_page(sg + i))
 404                                 goto unlock;
 405
 406                         err = memcpy_from_msg(page_address(sg_page(sg + i)),
 407                                               msg, plen);
 408                         if (err) {
 409                                 __free_page(sg_page(sg + i));
 410                                 sg_assign_page(sg + i, NULL);
 411                                 goto unlock;
 412                         }
 413
 414                         sg[i].length = plen;
 415                         len -= plen;
 416                         ctx->used += plen;
 417                         copied += plen;
 418                         size -= plen;
 419                         sgl->cur++;
 420                 } while (len && sgl->cur < MAX_SGL_ENTS);
 421
 422                 if (!size)
 423                         sg_mark_end(sg + sgl->cur - 1);
 424
 425                 ctx->merge = plen & (PAGE_SIZE - 1);
 426         }
 427
 428         err = 0;
 429
 430         ctx->more = msg->msg_flags & MSG_MORE;
 431
 432 unlock:
 433         skcipher_data_wakeup(sk);
 434         release_sock(sk);
 435
 436         return copied ?: err;
 437 }
 438
 439 static ssize_t skcipher_sendpage(struct socket *sock, struct page *page,
 440                                  int offset, size_t size, int flags)
 441 {
 442         struct sock *sk = sock->sk;
 443         struct alg_sock *ask = alg_sk(sk);
 444         struct skcipher_ctx *ctx = ask->private;
 445         struct skcipher_sg_list *sgl;
 446         int err = -EINVAL;
 447
 448         if (flags & MSG_SENDPAGE_NOTLAST)
 449                 flags |= MSG_MORE;
 450
 451         lock_sock(sk);
 452         if (!ctx->more && ctx->used)
 453                 goto unlock;
 454
 455         if (!size)
 456                 goto done;
 457
 458         if (!skcipher_writable(sk)) {
 459                 err = skcipher_wait_for_wmem(sk, flags);
 460                 if (err)
 461                         goto unlock;
 462         }
 463
 464         err = skcipher_alloc_sgl(sk);
 465         if (err)
 466                 goto unlock;
 467
 468         ctx->merge = 0;
 469         sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
 470
 471         if (sgl->cur)
 472                 sg_unmark_end(sgl->sg + sgl->cur - 1);
 473
 474         sg_mark_end(sgl->sg + sgl->cur);
 475         get_page(page);
 476         sg_set_page(sgl->sg + sgl->cur, page, size, offset);
 477         sgl->cur++;
 478         ctx->used += size;
 479
 480 done:
 481         ctx->more = flags & MSG_MORE;
 482
 483 unlock:
 484         skcipher_data_wakeup(sk);
 485         release_sock(sk);
 486
 487         return err ?: size;
 488 }
 489
 490 static int skcipher_all_sg_nents(struct skcipher_ctx *ctx)
 491 {
 492         struct skcipher_sg_list *sgl;
 493         struct scatterlist *sg;
 494         int nents = 0;
 495
 496         list_for_each_entry(sgl, &ctx->tsgl, list) {
 497                 sg = sgl->sg;
 498
 499                 while (!sg->length)
 500                         sg++;
 501
 502                 nents += sg_nents(sg);
 503         }
 504         return nents;
 505 }
 506
 507 static int skcipher_recvmsg_async(struct socket *sock, struct msghdr *msg,
 508                                   int flags)
 509 {
 510         struct sock *sk = sock->sk;
 511         struct alg_sock *ask = alg_sk(sk);
 512         struct skcipher_ctx *ctx = ask->private;
 513         struct skcipher_sg_list *sgl;
 514         struct scatterlist *sg;
 515         struct skcipher_async_req *sreq;
 516         struct skcipher_request *req;
 517         struct skcipher_async_rsgl *last_rsgl = NULL;
 518         unsigned int txbufs = 0, len = 0, tx_nents = skcipher_all_sg_nents(ctx);
 519         unsigned int reqlen = sizeof(struct skcipher_async_req) +
 520                                 GET_REQ_SIZE(ctx) + GET_IV_SIZE(ctx);
 521         int err = -ENOMEM;
 522         bool mark = false;
 523
 524         lock_sock(sk);
 525         req = kmalloc(reqlen, GFP_KERNEL);
 526         if (unlikely(!req))
 527                 goto unlock;
 528
 529         sreq = GET_SREQ(req, ctx);
 530         sreq->iocb = msg->msg_iocb;
 531         memset(&sreq->first_sgl, '\0', sizeof(struct skcipher_async_rsgl));
 532         INIT_LIST_HEAD(&sreq->list);
 533         sreq->tsg = kcalloc(tx_nents, sizeof(*sg), GFP_KERNEL);
 534         if (unlikely(!sreq->tsg)) {
 535                 kfree(req);
 536                 goto unlock;
 537         }
 538         sg_init_table(sreq->tsg, tx_nents);
 539         memcpy(sreq->iv, ctx->iv, GET_IV_SIZE(ctx));
 540         skcipher_request_set_tfm(req, crypto_skcipher_reqtfm(&ctx->req));
 541         skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
 542                                       skcipher_async_cb, sk);
 543
 544         while (iov_iter_count(&msg->msg_iter)) {
 545                 struct skcipher_async_rsgl *rsgl;
 546                 int used;
 547
 548                 if (!ctx->used) {
 549                         err = skcipher_wait_for_data(sk, flags);
 550                         if (err)
 551                                 goto free;
 552                 }
 553                 sgl = list_first_entry(&ctx->tsgl,
 554                                        struct skcipher_sg_list, list);
 555                 sg = sgl->sg;
 556
 557                 while (!sg->length)
 558                         sg++;
 559
 560                 used = min_t(unsigned long, ctx->used,
 561                              iov_iter_count(&msg->msg_iter));
 562                 used = min_t(unsigned long, used, sg->length);
 563
 564                 if (txbufs == tx_nents) {
 565                         struct scatterlist *tmp;
 566                         int x;
 567                         /* Ran out of tx slots in async request
 568                          * need to expand */
 569                         tmp = kcalloc(tx_nents * 2, sizeof(*tmp),
 570                                       GFP_KERNEL);
 571                         if (!tmp)
 572                                 goto free;
 573
 574                         sg_init_table(tmp, tx_nents * 2);
 575                         for (x = 0; x < tx_nents; x++)
 576                                 sg_set_page(&tmp[x], sg_page(&sreq->tsg[x]),
 577                                             sreq->tsg[x].length,
 578                                             sreq->tsg[x].offset);
 579                         kfree(sreq->tsg);
 580                         sreq->tsg = tmp;
 581                         tx_nents *= 2;
 582                         mark = true;
 583                 }
 584                 /* Need to take over the tx sgl from ctx
 585                  * to the asynch req - these sgls will be freed later */
 586                 sg_set_page(sreq->tsg + txbufs++, sg_page(sg), sg->length,
 587                             sg->offset);
 588
 589                 if (list_empty(&sreq->list)) {
 590                         rsgl = &sreq->first_sgl;
 591                         list_add_tail(&rsgl->list, &sreq->list);
 592                 } else {
 593                         rsgl = kmalloc(sizeof(*rsgl), GFP_KERNEL);
 594                         if (!rsgl) {
 595                                 err = -ENOMEM;
 596                                 goto free;
 597                         }
 598                         list_add_tail(&rsgl->list, &sreq->list);
 599                 }
 600
 601                 used = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, used);
 602                 err = used;
 603                 if (used < 0)
 604                         goto free;
 605                 if (last_rsgl)
 606                         af_alg_link_sg(&last_rsgl->sgl, &rsgl->sgl);
 607
 608                 last_rsgl = rsgl;
 609                 len += used;
 610                 skcipher_pull_sgl(sk, used, 0);
 611                 iov_iter_advance(&msg->msg_iter, used);
 612         }
 613
 614         if (mark)
 615                 sg_mark_end(sreq->tsg + txbufs - 1);
 616
 617         skcipher_request_set_crypt(req, sreq->tsg, sreq->first_sgl.sgl.sg,
 618                                    len, sreq->iv);
 619         err = ctx->enc ? crypto_skcipher_encrypt(req) :
 620                          crypto_skcipher_decrypt(req);
 621         if (err == -EINPROGRESS) {
 622                 atomic_inc(&ctx->inflight);
 623                 err = -EIOCBQUEUED;
 624                 goto unlock;
 625         }
 626 free:
 627         skcipher_free_async_sgls(sreq);
 628         kfree(req);
 629 unlock:
 630         skcipher_wmem_wakeup(sk);
 631         release_sock(sk);
 632         return err;
 633 }
 634
 635 static int skcipher_recvmsg_sync(struct socket *sock, struct msghdr *msg,
 636                                  int flags)
 637 {
 638         struct sock *sk = sock->sk;
 639         struct alg_sock *ask = alg_sk(sk);
 640         struct skcipher_ctx *ctx = ask->private;
 641         unsigned bs = crypto_skcipher_blocksize(crypto_skcipher_reqtfm(
 642                 &ctx->req));
 643         struct skcipher_sg_list *sgl;
 644         struct scatterlist *sg;
 645         int err = -EAGAIN;
 646         int used;
 647         long copied = 0;
 648
 649         lock_sock(sk);
 650         while (msg_data_left(msg)) {
 651                 if (!ctx->used) {
 652                         err = skcipher_wait_for_data(sk, flags);
 653                         if (err)
 654                                 goto unlock;
 655                 }
 656
 657                 used = min_t(unsigned long, ctx->used, msg_data_left(msg));
 658
 659                 used = af_alg_make_sg(&ctx->rsgl, &msg->msg_iter, used);
 660                 err = used;
 661                 if (err < 0)
 662                         goto unlock;
 663
 664                 if (ctx->more || used < ctx->used)
 665                         used -= used % bs;
 666
 667                 err = -EINVAL;
 668                 if (!used)
 669                         goto free;
 670
 671                 sgl = list_first_entry(&ctx->tsgl,
 672                                        struct skcipher_sg_list, list);
 673                 sg = sgl->sg;
 674
 675                 while (!sg->length)
 676                         sg++;
 677
 678                 skcipher_request_set_crypt(&ctx->req, sg, ctx->rsgl.sg, used,
 679                                            ctx->iv);
 680
 681                 err = af_alg_wait_for_completion(
 682                                 ctx->enc ?
 683                                         crypto_skcipher_encrypt(&ctx->req) :
 684                                         crypto_skcipher_decrypt(&ctx->req),
 685                                 &ctx->completion);
 686
 687 free:
 688                 af_alg_free_sg(&ctx->rsgl);
 689
 690                 if (err)
 691                         goto unlock;
 692
 693                 copied += used;
 694                 skcipher_pull_sgl(sk, used, 1);
 695                 iov_iter_advance(&msg->msg_iter, used);
 696         }
 697
 698         err = 0;
 699
 700 unlock:
 701         skcipher_wmem_wakeup(sk);
 702         release_sock(sk);
 703
 704         return copied ?: err;
 705 }
 706
 707 static int skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
 708                             size_t ignored, int flags)
 709 {
 710         return (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) ?
 711                 skcipher_recvmsg_async(sock, msg, flags) :
 712                 skcipher_recvmsg_sync(sock, msg, flags);
 713 }
 714
 715 static unsigned int skcipher_poll(struct file *file, struct socket *sock,
 716                                   poll_table *wait)
 717 {
 718         struct sock *sk = sock->sk;
 719         struct alg_sock *ask = alg_sk(sk);
 720         struct skcipher_ctx *ctx = ask->private;
 721         unsigned int mask;
 722
 723         sock_poll_wait(file, sk_sleep(sk), wait);
 724         mask = 0;
 725
 726         if (ctx->used)
 727                 mask |= POLLIN | POLLRDNORM;
 728
 729         if (skcipher_writable(sk))
 730                 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
 731
 732         return mask;
 733 }
 734
 735 static struct proto_ops algif_skcipher_ops = {
 736         .family         =       PF_ALG,
 737
 738         .connect        =       sock_no_connect,
 739         .socketpair     =       sock_no_socketpair,
 740         .getname        =       sock_no_getname,
 741         .ioctl          =       sock_no_ioctl,
 742         .listen         =       sock_no_listen,
 743         .shutdown       =       sock_no_shutdown,
 744         .getsockopt     =       sock_no_getsockopt,
 745         .mmap           =       sock_no_mmap,
 746         .bind           =       sock_no_bind,
 747         .accept         =       sock_no_accept,
 748         .setsockopt     =       sock_no_setsockopt,
 749
 750         .release        =       af_alg_release,
 751         .sendmsg        =       skcipher_sendmsg,
 752         .sendpage       =       skcipher_sendpage,
 753         .recvmsg        =       skcipher_recvmsg,
 754         .poll           =       skcipher_poll,
 755 };
 756
 757 static int skcipher_check_key(struct socket *sock)
 758 {
 759         int err = 0;
 760         struct sock *psk;
 761         struct alg_sock *pask;
 762         struct skcipher_tfm *tfm;
 763         struct sock *sk = sock->sk;
 764         struct alg_sock *ask = alg_sk(sk);
 765
 766         lock_sock(sk);
 767         if (ask->refcnt)
 768                 goto unlock_child;
 769
 770         psk = ask->parent;
 771         pask = alg_sk(ask->parent);
 772         tfm = pask->private;
 773
 774         err = -ENOKEY;
 775         lock_sock_nested(psk, SINGLE_DEPTH_NESTING);
 776         if (!tfm->has_key)
 777                 goto unlock;
 778
 779         if (!pask->refcnt++)
 780                 sock_hold(psk);
 781
 782         ask->refcnt = 1;
 783         sock_put(psk);
 784
 785         err = 0;
 786
 787 unlock:
 788         release_sock(psk);
 789 unlock_child:
 790         release_sock(sk);
 791
 792         return err;
 793 }
 794
 795 static int skcipher_sendmsg_nokey(struct socket *sock, struct msghdr *msg,
 796                                   size_t size)
 797 {
 798         int err;
 799
 800         err = skcipher_check_key(sock);
 801         if (err)
 802                 return err;
 803
 804         return skcipher_sendmsg(sock, msg, size);
 805 }
 806
 807 static ssize_t skcipher_sendpage_nokey(struct socket *sock, struct page *page,
 808                                        int offset, size_t size, int flags)
 809 {
 810         int err;
 811
 812         err = skcipher_check_key(sock);
 813         if (err)
 814                 return err;
 815
 816         return skcipher_sendpage(sock, page, offset, size, flags);
 817 }
 818
 819 static int skcipher_recvmsg_nokey(struct socket *sock, struct msghdr *msg,
 820                                   size_t ignored, int flags)
 821 {
 822         int err;
 823
 824         err = skcipher_check_key(sock);
 825         if (err)
 826                 return err;
 827
 828         return skcipher_recvmsg(sock, msg, ignored, flags);
 829 }
 830
 831 static struct proto_ops algif_skcipher_ops_nokey = {
 832         .family         =       PF_ALG,
 833
 834         .connect        =       sock_no_connect,
 835         .socketpair     =       sock_no_socketpair,
 836         .getname        =       sock_no_getname,
 837         .ioctl          =       sock_no_ioctl,
 838         .listen         =       sock_no_listen,
 839         .shutdown       =       sock_no_shutdown,
 840         .getsockopt     =       sock_no_getsockopt,
 841         .mmap           =       sock_no_mmap,
 842         .bind           =       sock_no_bind,
 843         .accept         =       sock_no_accept,
 844         .setsockopt     =       sock_no_setsockopt,
 845
 846         .release        =       af_alg_release,
 847         .sendmsg        =       skcipher_sendmsg_nokey,
 848         .sendpage       =       skcipher_sendpage_nokey,
 849         .recvmsg        =       skcipher_recvmsg_nokey,
 850         .poll           =       skcipher_poll,
 851 };
 852
 853 static void *skcipher_bind(const char *name, u32 type, u32 mask)
 854 {
 855         struct skcipher_tfm *tfm;
 856         struct crypto_skcipher *skcipher;
 857
 858         tfm = kzalloc(sizeof(*tfm), GFP_KERNEL);
 859         if (!tfm)
 860                 return ERR_PTR(-ENOMEM);
 861
 862         skcipher = crypto_alloc_skcipher(name, type, mask);
 863         if (IS_ERR(skcipher)) {
 864                 kfree(tfm);
 865                 return ERR_CAST(skcipher);
 866         }
 867
 868         tfm->skcipher = skcipher;
 869
 870         return tfm;
 871 }
 872
 873 static void skcipher_release(void *private)
 874 {
 875         struct skcipher_tfm *tfm = private;
 876
 877         crypto_free_skcipher(tfm->skcipher);
 878         kfree(tfm);
 879 }
 880
 881 static int skcipher_setkey(void *private, const u8 *key, unsigned int keylen)
 882 {
 883         struct skcipher_tfm *tfm = private;
 884         int err;
 885
 886         err = crypto_skcipher_setkey(tfm->skcipher, key, keylen);
 887         tfm->has_key = !err;
 888
 889         return err;
 890 }
 891
 892 static void skcipher_wait(struct sock *sk)
 893 {
 894         struct alg_sock *ask = alg_sk(sk);
 895         struct skcipher_ctx *ctx = ask->private;
 896         int ctr = 0;
 897
 898         while (atomic_read(&ctx->inflight) && ctr++ < 100)
 899                 msleep(100);
 900 }
 901
 902 static void skcipher_sock_destruct(struct sock *sk)
 903 {
 904         struct alg_sock *ask = alg_sk(sk);
 905         struct skcipher_ctx *ctx = ask->private;
 906         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(&ctx->req);
 907
 908         if (atomic_read(&ctx->inflight))
 909                 skcipher_wait(sk);
 910
 911         skcipher_free_sgl(sk);
 912         sock_kzfree_s(sk, ctx->iv, crypto_skcipher_ivsize(tfm));
 913         sock_kfree_s(sk, ctx, ctx->len);
 914         af_alg_release_parent(sk);
 915 }
 916
 917 static int skcipher_accept_parent_nokey(void *private, struct sock *sk)
 918 {
 919         struct skcipher_ctx *ctx;
 920         struct alg_sock *ask = alg_sk(sk);
 921         struct skcipher_tfm *tfm = private;
 922         struct crypto_skcipher *skcipher = tfm->skcipher;
 923         unsigned int len = sizeof(*ctx) + crypto_skcipher_reqsize(skcipher);
 924
 925         ctx = sock_kmalloc(sk, len, GFP_KERNEL);
 926         if (!ctx)
 927                 return -ENOMEM;
 928
 929         ctx->iv = sock_kmalloc(sk, crypto_skcipher_ivsize(skcipher),
 930                                GFP_KERNEL);
 931         if (!ctx->iv) {
 932                 sock_kfree_s(sk, ctx, len);
 933                 return -ENOMEM;
 934         }
 935
 936         memset(ctx->iv, 0, crypto_skcipher_ivsize(skcipher));
 937
 938         INIT_LIST_HEAD(&ctx->tsgl);
 939         ctx->len = len;
 940         ctx->used = 0;
 941         ctx->more = 0;
 942         ctx->merge = 0;
 943         ctx->enc = 0;
 944         atomic_set(&ctx->inflight, 0);
 945         af_alg_init_completion(&ctx->completion);
 946
 947         ask->private = ctx;
 948
 949         skcipher_request_set_tfm(&ctx->req, skcipher);
 950         skcipher_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
 951                                       af_alg_complete, &ctx->completion);
 952
 953         sk->sk_destruct = skcipher_sock_destruct;
 954
 955         return 0;
 956 }
 957
 958 static int skcipher_accept_parent(void *private, struct sock *sk)
 959 {
 960         struct skcipher_tfm *tfm = private;
 961
 962         if (!tfm->has_key && crypto_skcipher_has_setkey(tfm->skcipher))
 963                 return -ENOKEY;
 964
 965         return skcipher_accept_parent_nokey(private, sk);
 966 }
 967
 968 static const struct af_alg_type algif_type_skcipher = {
 969         .bind           =       skcipher_bind,
 970         .release        =       skcipher_release,
 971         .setkey         =       skcipher_setkey,
 972         .accept         =       skcipher_accept_parent,
 973         .accept_nokey   =       skcipher_accept_parent_nokey,
 974         .ops            =       &algif_skcipher_ops,
 975         .ops_nokey      =       &algif_skcipher_ops_nokey,
 976         .name           =       "skcipher",
 977         .owner          =       THIS_MODULE
 978 };
 979
 980 static int __init algif_skcipher_init(void)
 981 {
 982         return af_alg_register_type(&algif_type_skcipher);
 983 }
 984
 985 static void __exit algif_skcipher_exit(void)
 986 {
 987         int err = af_alg_unregister_type(&algif_type_skcipher);
 988         BUG_ON(err);
 989 }
 990
 991 module_init(algif_skcipher_init);
 992 module_exit(algif_skcipher_exit);
 993 MODULE_LICENSE("GPL");