linux/crypto/algif_skcipher.c
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   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
  26struct skcipher_sg_list {
  27        struct list_head list;
  28
  29        int cur;
  30
  31        struct scatterlist sg[0];
  32};
  33
  34struct skcipher_tfm {
  35        struct crypto_skcipher *skcipher;
  36        bool has_key;
  37};
  38
  39struct 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
  58struct skcipher_async_rsgl {
  59        struct af_alg_sgl sgl;
  60        struct list_head list;
  61};
  62
  63struct skcipher_async_req {
  64        struct kiocb *iocb;
  65        struct skcipher_async_rsgl first_sgl;
  66        struct list_head list;
  67        struct scatterlist *tsg;
  68        atomic_t *inflight;
  69        struct skcipher_request req;
  70};
  71
  72#define MAX_SGL_ENTS ((4096 - sizeof(struct skcipher_sg_list)) / \
  73                      sizeof(struct scatterlist) - 1)
  74
  75static void skcipher_free_async_sgls(struct skcipher_async_req *sreq)
  76{
  77        struct skcipher_async_rsgl *rsgl, *tmp;
  78        struct scatterlist *sgl;
  79        struct scatterlist *sg;
  80        int i, n;
  81
  82        list_for_each_entry_safe(rsgl, tmp, &sreq->list, list) {
  83                af_alg_free_sg(&rsgl->sgl);
  84                if (rsgl != &sreq->first_sgl)
  85                        kfree(rsgl);
  86        }
  87        sgl = sreq->tsg;
  88        n = sg_nents(sgl);
  89        for_each_sg(sgl, sg, n, i)
  90                put_page(sg_page(sg));
  91
  92        kfree(sreq->tsg);
  93}
  94
  95static void skcipher_async_cb(struct crypto_async_request *req, int err)
  96{
  97        struct skcipher_async_req *sreq = req->data;
  98        struct kiocb *iocb = sreq->iocb;
  99
 100        atomic_dec(sreq->inflight);
 101        skcipher_free_async_sgls(sreq);
 102        kzfree(sreq);
 103        iocb->ki_complete(iocb, err, err);
 104}
 105
 106static inline int skcipher_sndbuf(struct sock *sk)
 107{
 108        struct alg_sock *ask = alg_sk(sk);
 109        struct skcipher_ctx *ctx = ask->private;
 110
 111        return max_t(int, max_t(int, sk->sk_sndbuf & PAGE_MASK, PAGE_SIZE) -
 112                          ctx->used, 0);
 113}
 114
 115static inline bool skcipher_writable(struct sock *sk)
 116{
 117        return PAGE_SIZE <= skcipher_sndbuf(sk);
 118}
 119
 120static int skcipher_alloc_sgl(struct sock *sk)
 121{
 122        struct alg_sock *ask = alg_sk(sk);
 123        struct skcipher_ctx *ctx = ask->private;
 124        struct skcipher_sg_list *sgl;
 125        struct scatterlist *sg = NULL;
 126
 127        sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
 128        if (!list_empty(&ctx->tsgl))
 129                sg = sgl->sg;
 130
 131        if (!sg || sgl->cur >= MAX_SGL_ENTS) {
 132                sgl = sock_kmalloc(sk, sizeof(*sgl) +
 133                                       sizeof(sgl->sg[0]) * (MAX_SGL_ENTS + 1),
 134                                   GFP_KERNEL);
 135                if (!sgl)
 136                        return -ENOMEM;
 137
 138                sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
 139                sgl->cur = 0;
 140
 141                if (sg)
 142                        sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
 143
 144                list_add_tail(&sgl->list, &ctx->tsgl);
 145        }
 146
 147        return 0;
 148}
 149
 150static void skcipher_pull_sgl(struct sock *sk, size_t used, int put)
 151{
 152        struct alg_sock *ask = alg_sk(sk);
 153        struct skcipher_ctx *ctx = ask->private;
 154        struct skcipher_sg_list *sgl;
 155        struct scatterlist *sg;
 156        int i;
 157
 158        while (!list_empty(&ctx->tsgl)) {
 159                sgl = list_first_entry(&ctx->tsgl, struct skcipher_sg_list,
 160                                       list);
 161                sg = sgl->sg;
 162
 163                for (i = 0; i < sgl->cur; i++) {
 164                        size_t plen = min_t(size_t, used, sg[i].length);
 165
 166                        if (!sg_page(sg + i))
 167                                continue;
 168
 169                        sg[i].length -= plen;
 170                        sg[i].offset += plen;
 171
 172                        used -= plen;
 173                        ctx->used -= plen;
 174
 175                        if (sg[i].length)
 176                                return;
 177                        if (put)
 178                                put_page(sg_page(sg + i));
 179                        sg_assign_page(sg + i, NULL);
 180                }
 181
 182                list_del(&sgl->list);
 183                sock_kfree_s(sk, sgl,
 184                             sizeof(*sgl) + sizeof(sgl->sg[0]) *
 185                                            (MAX_SGL_ENTS + 1));
 186        }
 187
 188        if (!ctx->used)
 189                ctx->merge = 0;
 190}
 191
 192static void skcipher_free_sgl(struct sock *sk)
 193{
 194        struct alg_sock *ask = alg_sk(sk);
 195        struct skcipher_ctx *ctx = ask->private;
 196
 197        skcipher_pull_sgl(sk, ctx->used, 1);
 198}
 199
 200static int skcipher_wait_for_wmem(struct sock *sk, unsigned flags)
 201{
 202        long timeout;
 203        DEFINE_WAIT(wait);
 204        int err = -ERESTARTSYS;
 205
 206        if (flags & MSG_DONTWAIT)
 207                return -EAGAIN;
 208
 209        sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 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, skcipher_writable(sk))) {
 217                        err = 0;
 218                        break;
 219                }
 220        }
 221        finish_wait(sk_sleep(sk), &wait);
 222
 223        return err;
 224}
 225
 226static void skcipher_wmem_wakeup(struct sock *sk)
 227{
 228        struct socket_wq *wq;
 229
 230        if (!skcipher_writable(sk))
 231                return;
 232
 233        rcu_read_lock();
 234        wq = rcu_dereference(sk->sk_wq);
 235        if (skwq_has_sleeper(wq))
 236                wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
 237                                                           POLLRDNORM |
 238                                                           POLLRDBAND);
 239        sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
 240        rcu_read_unlock();
 241}
 242
 243static int skcipher_wait_for_data(struct sock *sk, unsigned flags)
 244{
 245        struct alg_sock *ask = alg_sk(sk);
 246        struct skcipher_ctx *ctx = ask->private;
 247        long timeout;
 248        DEFINE_WAIT(wait);
 249        int err = -ERESTARTSYS;
 250
 251        if (flags & MSG_DONTWAIT) {
 252                return -EAGAIN;
 253        }
 254
 255        sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
 256
 257        for (;;) {
 258                if (signal_pending(current))
 259                        break;
 260                prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 261                timeout = MAX_SCHEDULE_TIMEOUT;
 262                if (sk_wait_event(sk, &timeout, ctx->used)) {
 263                        err = 0;
 264                        break;
 265                }
 266        }
 267        finish_wait(sk_sleep(sk), &wait);
 268
 269        sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
 270
 271        return err;
 272}
 273
 274static void skcipher_data_wakeup(struct sock *sk)
 275{
 276        struct alg_sock *ask = alg_sk(sk);
 277        struct skcipher_ctx *ctx = ask->private;
 278        struct socket_wq *wq;
 279
 280        if (!ctx->used)
 281                return;
 282
 283        rcu_read_lock();
 284        wq = rcu_dereference(sk->sk_wq);
 285        if (skwq_has_sleeper(wq))
 286                wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
 287                                                           POLLRDNORM |
 288                                                           POLLRDBAND);
 289        sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
 290        rcu_read_unlock();
 291}
 292
 293static int skcipher_sendmsg(struct socket *sock, struct msghdr *msg,
 294                            size_t size)
 295{
 296        struct sock *sk = sock->sk;
 297        struct alg_sock *ask = alg_sk(sk);
 298        struct sock *psk = ask->parent;
 299        struct alg_sock *pask = alg_sk(psk);
 300        struct skcipher_ctx *ctx = ask->private;
 301        struct skcipher_tfm *skc = pask->private;
 302        struct crypto_skcipher *tfm = skc->skcipher;
 303        unsigned ivsize = crypto_skcipher_ivsize(tfm);
 304        struct skcipher_sg_list *sgl;
 305        struct af_alg_control con = {};
 306        long copied = 0;
 307        bool enc = 0;
 308        bool init = 0;
 309        int err;
 310        int i;
 311
 312        if (msg->msg_controllen) {
 313                err = af_alg_cmsg_send(msg, &con);
 314                if (err)
 315                        return err;
 316
 317                init = 1;
 318                switch (con.op) {
 319                case ALG_OP_ENCRYPT:
 320                        enc = 1;
 321                        break;
 322                case ALG_OP_DECRYPT:
 323                        enc = 0;
 324                        break;
 325                default:
 326                        return -EINVAL;
 327                }
 328
 329                if (con.iv && con.iv->ivlen != ivsize)
 330                        return -EINVAL;
 331        }
 332
 333        err = -EINVAL;
 334
 335        lock_sock(sk);
 336        if (!ctx->more && ctx->used)
 337                goto unlock;
 338
 339        if (init) {
 340                ctx->enc = enc;
 341                if (con.iv)
 342                        memcpy(ctx->iv, con.iv->iv, ivsize);
 343        }
 344
 345        while (size) {
 346                struct scatterlist *sg;
 347                unsigned long len = size;
 348                size_t plen;
 349
 350                if (ctx->merge) {
 351                        sgl = list_entry(ctx->tsgl.prev,
 352                                         struct skcipher_sg_list, list);
 353                        sg = sgl->sg + sgl->cur - 1;
 354                        len = min_t(unsigned long, len,
 355                                    PAGE_SIZE - sg->offset - sg->length);
 356
 357                        err = memcpy_from_msg(page_address(sg_page(sg)) +
 358                                              sg->offset + sg->length,
 359                                              msg, len);
 360                        if (err)
 361                                goto unlock;
 362
 363                        sg->length += len;
 364                        ctx->merge = (sg->offset + sg->length) &
 365                                     (PAGE_SIZE - 1);
 366
 367                        ctx->used += len;
 368                        copied += len;
 369                        size -= len;
 370                        continue;
 371                }
 372
 373                if (!skcipher_writable(sk)) {
 374                        err = skcipher_wait_for_wmem(sk, msg->msg_flags);
 375                        if (err)
 376                                goto unlock;
 377                }
 378
 379                len = min_t(unsigned long, len, skcipher_sndbuf(sk));
 380
 381                err = skcipher_alloc_sgl(sk);
 382                if (err)
 383                        goto unlock;
 384
 385                sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
 386                sg = sgl->sg;
 387                if (sgl->cur)
 388                        sg_unmark_end(sg + sgl->cur - 1);
 389                do {
 390                        i = sgl->cur;
 391                        plen = min_t(size_t, len, PAGE_SIZE);
 392
 393                        sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
 394                        err = -ENOMEM;
 395                        if (!sg_page(sg + i))
 396                                goto unlock;
 397
 398                        err = memcpy_from_msg(page_address(sg_page(sg + i)),
 399                                              msg, plen);
 400                        if (err) {
 401                                __free_page(sg_page(sg + i));
 402                                sg_assign_page(sg + i, NULL);
 403                                goto unlock;
 404                        }
 405
 406                        sg[i].length = plen;
 407                        len -= plen;
 408                        ctx->used += plen;
 409                        copied += plen;
 410                        size -= plen;
 411                        sgl->cur++;
 412                } while (len && sgl->cur < MAX_SGL_ENTS);
 413
 414                if (!size)
 415                        sg_mark_end(sg + sgl->cur - 1);
 416
 417                ctx->merge = plen & (PAGE_SIZE - 1);
 418        }
 419
 420        err = 0;
 421
 422        ctx->more = msg->msg_flags & MSG_MORE;
 423
 424unlock:
 425        skcipher_data_wakeup(sk);
 426        release_sock(sk);
 427
 428        return copied ?: err;
 429}
 430
 431static ssize_t skcipher_sendpage(struct socket *sock, struct page *page,
 432                                 int offset, size_t size, int flags)
 433{
 434        struct sock *sk = sock->sk;
 435        struct alg_sock *ask = alg_sk(sk);
 436        struct skcipher_ctx *ctx = ask->private;
 437        struct skcipher_sg_list *sgl;
 438        int err = -EINVAL;
 439
 440        if (flags & MSG_SENDPAGE_NOTLAST)
 441                flags |= MSG_MORE;
 442
 443        lock_sock(sk);
 444        if (!ctx->more && ctx->used)
 445                goto unlock;
 446
 447        if (!size)
 448                goto done;
 449
 450        if (!skcipher_writable(sk)) {
 451                err = skcipher_wait_for_wmem(sk, flags);
 452                if (err)
 453                        goto unlock;
 454        }
 455
 456        err = skcipher_alloc_sgl(sk);
 457        if (err)
 458                goto unlock;
 459
 460        ctx->merge = 0;
 461        sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
 462
 463        if (sgl->cur)
 464                sg_unmark_end(sgl->sg + sgl->cur - 1);
 465
 466        sg_mark_end(sgl->sg + sgl->cur);
 467        get_page(page);
 468        sg_set_page(sgl->sg + sgl->cur, page, size, offset);
 469        sgl->cur++;
 470        ctx->used += size;
 471
 472done:
 473        ctx->more = flags & MSG_MORE;
 474
 475unlock:
 476        skcipher_data_wakeup(sk);
 477        release_sock(sk);
 478
 479        return err ?: size;
 480}
 481
 482static int skcipher_all_sg_nents(struct skcipher_ctx *ctx)
 483{
 484        struct skcipher_sg_list *sgl;
 485        struct scatterlist *sg;
 486        int nents = 0;
 487
 488        list_for_each_entry(sgl, &ctx->tsgl, list) {
 489                sg = sgl->sg;
 490
 491                while (!sg->length)
 492                        sg++;
 493
 494                nents += sg_nents(sg);
 495        }
 496        return nents;
 497}
 498
 499static int skcipher_recvmsg_async(struct socket *sock, struct msghdr *msg,
 500                                  int flags)
 501{
 502        struct sock *sk = sock->sk;
 503        struct alg_sock *ask = alg_sk(sk);
 504        struct sock *psk = ask->parent;
 505        struct alg_sock *pask = alg_sk(psk);
 506        struct skcipher_ctx *ctx = ask->private;
 507        struct skcipher_tfm *skc = pask->private;
 508        struct crypto_skcipher *tfm = skc->skcipher;
 509        struct skcipher_sg_list *sgl;
 510        struct scatterlist *sg;
 511        struct skcipher_async_req *sreq;
 512        struct skcipher_request *req;
 513        struct skcipher_async_rsgl *last_rsgl = NULL;
 514        unsigned int txbufs = 0, len = 0, tx_nents;
 515        unsigned int reqsize = crypto_skcipher_reqsize(tfm);
 516        unsigned int ivsize = crypto_skcipher_ivsize(tfm);
 517        int err = -ENOMEM;
 518        bool mark = false;
 519        char *iv;
 520
 521        sreq = kzalloc(sizeof(*sreq) + reqsize + ivsize, GFP_KERNEL);
 522        if (unlikely(!sreq))
 523                goto out;
 524
 525        req = &sreq->req;
 526        iv = (char *)(req + 1) + reqsize;
 527        sreq->iocb = msg->msg_iocb;
 528        INIT_LIST_HEAD(&sreq->list);
 529        sreq->inflight = &ctx->inflight;
 530
 531        lock_sock(sk);
 532        tx_nents = skcipher_all_sg_nents(ctx);
 533        sreq->tsg = kcalloc(tx_nents, sizeof(*sg), GFP_KERNEL);
 534        if (unlikely(!sreq->tsg))
 535                goto unlock;
 536        sg_init_table(sreq->tsg, tx_nents);
 537        memcpy(iv, ctx->iv, ivsize);
 538        skcipher_request_set_tfm(req, tfm);
 539        skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP,
 540                                      skcipher_async_cb, sreq);
 541
 542        while (iov_iter_count(&msg->msg_iter)) {
 543                struct skcipher_async_rsgl *rsgl;
 544                int used;
 545
 546                if (!ctx->used) {
 547                        err = skcipher_wait_for_data(sk, flags);
 548                        if (err)
 549                                goto free;
 550                }
 551                sgl = list_first_entry(&ctx->tsgl,
 552                                       struct skcipher_sg_list, list);
 553                sg = sgl->sg;
 554
 555                while (!sg->length)
 556                        sg++;
 557
 558                used = min_t(unsigned long, ctx->used,
 559                             iov_iter_count(&msg->msg_iter));
 560                used = min_t(unsigned long, used, sg->length);
 561
 562                if (txbufs == tx_nents) {
 563                        struct scatterlist *tmp;
 564                        int x;
 565                        /* Ran out of tx slots in async request
 566                         * need to expand */
 567                        tmp = kcalloc(tx_nents * 2, sizeof(*tmp),
 568                                      GFP_KERNEL);
 569                        if (!tmp)
 570                                goto free;
 571
 572                        sg_init_table(tmp, tx_nents * 2);
 573                        for (x = 0; x < tx_nents; x++)
 574                                sg_set_page(&tmp[x], sg_page(&sreq->tsg[x]),
 575                                            sreq->tsg[x].length,
 576                                            sreq->tsg[x].offset);
 577                        kfree(sreq->tsg);
 578                        sreq->tsg = tmp;
 579                        tx_nents *= 2;
 580                        mark = true;
 581                }
 582                /* Need to take over the tx sgl from ctx
 583                 * to the asynch req - these sgls will be freed later */
 584                sg_set_page(sreq->tsg + txbufs++, sg_page(sg), sg->length,
 585                            sg->offset);
 586
 587                if (list_empty(&sreq->list)) {
 588                        rsgl = &sreq->first_sgl;
 589                        list_add_tail(&rsgl->list, &sreq->list);
 590                } else {
 591                        rsgl = kmalloc(sizeof(*rsgl), GFP_KERNEL);
 592                        if (!rsgl) {
 593                                err = -ENOMEM;
 594                                goto free;
 595                        }
 596                        list_add_tail(&rsgl->list, &sreq->list);
 597                }
 598
 599                used = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, used);
 600                err = used;
 601                if (used < 0)
 602                        goto free;
 603                if (last_rsgl)
 604                        af_alg_link_sg(&last_rsgl->sgl, &rsgl->sgl);
 605
 606                last_rsgl = rsgl;
 607                len += used;
 608                skcipher_pull_sgl(sk, used, 0);
 609                iov_iter_advance(&msg->msg_iter, used);
 610        }
 611
 612        if (mark)
 613                sg_mark_end(sreq->tsg + txbufs - 1);
 614
 615        skcipher_request_set_crypt(req, sreq->tsg, sreq->first_sgl.sgl.sg,
 616                                   len, iv);
 617        err = ctx->enc ? crypto_skcipher_encrypt(req) :
 618                         crypto_skcipher_decrypt(req);
 619        if (err == -EINPROGRESS) {
 620                atomic_inc(&ctx->inflight);
 621                err = -EIOCBQUEUED;
 622                sreq = NULL;
 623                goto unlock;
 624        }
 625free:
 626        skcipher_free_async_sgls(sreq);
 627unlock:
 628        skcipher_wmem_wakeup(sk);
 629        release_sock(sk);
 630        kzfree(sreq);
 631out:
 632        return err;
 633}
 634
 635static 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 sock *psk = ask->parent;
 641        struct alg_sock *pask = alg_sk(psk);
 642        struct skcipher_ctx *ctx = ask->private;
 643        struct skcipher_tfm *skc = pask->private;
 644        struct crypto_skcipher *tfm = skc->skcipher;
 645        unsigned bs = crypto_skcipher_blocksize(tfm);
 646        struct skcipher_sg_list *sgl;
 647        struct scatterlist *sg;
 648        int err = -EAGAIN;
 649        int used;
 650        long copied = 0;
 651
 652        lock_sock(sk);
 653        while (msg_data_left(msg)) {
 654                if (!ctx->used) {
 655                        err = skcipher_wait_for_data(sk, flags);
 656                        if (err)
 657                                goto unlock;
 658                }
 659
 660                used = min_t(unsigned long, ctx->used, msg_data_left(msg));
 661
 662                used = af_alg_make_sg(&ctx->rsgl, &msg->msg_iter, used);
 663                err = used;
 664                if (err < 0)
 665                        goto unlock;
 666
 667                if (ctx->more || used < ctx->used)
 668                        used -= used % bs;
 669
 670                err = -EINVAL;
 671                if (!used)
 672                        goto free;
 673
 674                sgl = list_first_entry(&ctx->tsgl,
 675                                       struct skcipher_sg_list, list);
 676                sg = sgl->sg;
 677
 678                while (!sg->length)
 679                        sg++;
 680
 681                skcipher_request_set_crypt(&ctx->req, sg, ctx->rsgl.sg, used,
 682                                           ctx->iv);
 683
 684                err = af_alg_wait_for_completion(
 685                                ctx->enc ?
 686                                        crypto_skcipher_encrypt(&ctx->req) :
 687                                        crypto_skcipher_decrypt(&ctx->req),
 688                                &ctx->completion);
 689
 690free:
 691                af_alg_free_sg(&ctx->rsgl);
 692
 693                if (err)
 694                        goto unlock;
 695
 696                copied += used;
 697                skcipher_pull_sgl(sk, used, 1);
 698                iov_iter_advance(&msg->msg_iter, used);
 699        }
 700
 701        err = 0;
 702
 703unlock:
 704        skcipher_wmem_wakeup(sk);
 705        release_sock(sk);
 706
 707        return copied ?: err;
 708}
 709
 710static int skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
 711                            size_t ignored, int flags)
 712{
 713        return (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) ?
 714                skcipher_recvmsg_async(sock, msg, flags) :
 715                skcipher_recvmsg_sync(sock, msg, flags);
 716}
 717
 718static unsigned int skcipher_poll(struct file *file, struct socket *sock,
 719                                  poll_table *wait)
 720{
 721        struct sock *sk = sock->sk;
 722        struct alg_sock *ask = alg_sk(sk);
 723        struct skcipher_ctx *ctx = ask->private;
 724        unsigned int mask;
 725
 726        sock_poll_wait(file, sk_sleep(sk), wait);
 727        mask = 0;
 728
 729        if (ctx->used)
 730                mask |= POLLIN | POLLRDNORM;
 731
 732        if (skcipher_writable(sk))
 733                mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
 734
 735        return mask;
 736}
 737
 738static struct proto_ops algif_skcipher_ops = {
 739        .family         =       PF_ALG,
 740
 741        .connect        =       sock_no_connect,
 742        .socketpair     =       sock_no_socketpair,
 743        .getname        =       sock_no_getname,
 744        .ioctl          =       sock_no_ioctl,
 745        .listen         =       sock_no_listen,
 746        .shutdown       =       sock_no_shutdown,
 747        .getsockopt     =       sock_no_getsockopt,
 748        .mmap           =       sock_no_mmap,
 749        .bind           =       sock_no_bind,
 750        .accept         =       sock_no_accept,
 751        .setsockopt     =       sock_no_setsockopt,
 752
 753        .release        =       af_alg_release,
 754        .sendmsg        =       skcipher_sendmsg,
 755        .sendpage       =       skcipher_sendpage,
 756        .recvmsg        =       skcipher_recvmsg,
 757        .poll           =       skcipher_poll,
 758};
 759
 760static int skcipher_check_key(struct socket *sock)
 761{
 762        int err = 0;
 763        struct sock *psk;
 764        struct alg_sock *pask;
 765        struct skcipher_tfm *tfm;
 766        struct sock *sk = sock->sk;
 767        struct alg_sock *ask = alg_sk(sk);
 768
 769        lock_sock(sk);
 770        if (ask->refcnt)
 771                goto unlock_child;
 772
 773        psk = ask->parent;
 774        pask = alg_sk(ask->parent);
 775        tfm = pask->private;
 776
 777        err = -ENOKEY;
 778        lock_sock_nested(psk, SINGLE_DEPTH_NESTING);
 779        if (!tfm->has_key)
 780                goto unlock;
 781
 782        if (!pask->refcnt++)
 783                sock_hold(psk);
 784
 785        ask->refcnt = 1;
 786        sock_put(psk);
 787
 788        err = 0;
 789
 790unlock:
 791        release_sock(psk);
 792unlock_child:
 793        release_sock(sk);
 794
 795        return err;
 796}
 797
 798static int skcipher_sendmsg_nokey(struct socket *sock, struct msghdr *msg,
 799                                  size_t size)
 800{
 801        int err;
 802
 803        err = skcipher_check_key(sock);
 804        if (err)
 805                return err;
 806
 807        return skcipher_sendmsg(sock, msg, size);
 808}
 809
 810static ssize_t skcipher_sendpage_nokey(struct socket *sock, struct page *page,
 811                                       int offset, size_t size, int flags)
 812{
 813        int err;
 814
 815        err = skcipher_check_key(sock);
 816        if (err)
 817                return err;
 818
 819        return skcipher_sendpage(sock, page, offset, size, flags);
 820}
 821
 822static int skcipher_recvmsg_nokey(struct socket *sock, struct msghdr *msg,
 823                                  size_t ignored, int flags)
 824{
 825        int err;
 826
 827        err = skcipher_check_key(sock);
 828        if (err)
 829                return err;
 830
 831        return skcipher_recvmsg(sock, msg, ignored, flags);
 832}
 833
 834static struct proto_ops algif_skcipher_ops_nokey = {
 835        .family         =       PF_ALG,
 836
 837        .connect        =       sock_no_connect,
 838        .socketpair     =       sock_no_socketpair,
 839        .getname        =       sock_no_getname,
 840        .ioctl          =       sock_no_ioctl,
 841        .listen         =       sock_no_listen,
 842        .shutdown       =       sock_no_shutdown,
 843        .getsockopt     =       sock_no_getsockopt,
 844        .mmap           =       sock_no_mmap,
 845        .bind           =       sock_no_bind,
 846        .accept         =       sock_no_accept,
 847        .setsockopt     =       sock_no_setsockopt,
 848
 849        .release        =       af_alg_release,
 850        .sendmsg        =       skcipher_sendmsg_nokey,
 851        .sendpage       =       skcipher_sendpage_nokey,
 852        .recvmsg        =       skcipher_recvmsg_nokey,
 853        .poll           =       skcipher_poll,
 854};
 855
 856static void *skcipher_bind(const char *name, u32 type, u32 mask)
 857{
 858        struct skcipher_tfm *tfm;
 859        struct crypto_skcipher *skcipher;
 860
 861        tfm = kzalloc(sizeof(*tfm), GFP_KERNEL);
 862        if (!tfm)
 863                return ERR_PTR(-ENOMEM);
 864
 865        skcipher = crypto_alloc_skcipher(name, type, mask);
 866        if (IS_ERR(skcipher)) {
 867                kfree(tfm);
 868                return ERR_CAST(skcipher);
 869        }
 870
 871        tfm->skcipher = skcipher;
 872
 873        return tfm;
 874}
 875
 876static void skcipher_release(void *private)
 877{
 878        struct skcipher_tfm *tfm = private;
 879
 880        crypto_free_skcipher(tfm->skcipher);
 881        kfree(tfm);
 882}
 883
 884static int skcipher_setkey(void *private, const u8 *key, unsigned int keylen)
 885{
 886        struct skcipher_tfm *tfm = private;
 887        int err;
 888
 889        err = crypto_skcipher_setkey(tfm->skcipher, key, keylen);
 890        tfm->has_key = !err;
 891
 892        return err;
 893}
 894
 895static void skcipher_wait(struct sock *sk)
 896{
 897        struct alg_sock *ask = alg_sk(sk);
 898        struct skcipher_ctx *ctx = ask->private;
 899        int ctr = 0;
 900
 901        while (atomic_read(&ctx->inflight) && ctr++ < 100)
 902                msleep(100);
 903}
 904
 905static void skcipher_sock_destruct(struct sock *sk)
 906{
 907        struct alg_sock *ask = alg_sk(sk);
 908        struct skcipher_ctx *ctx = ask->private;
 909        struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(&ctx->req);
 910
 911        if (atomic_read(&ctx->inflight))
 912                skcipher_wait(sk);
 913
 914        skcipher_free_sgl(sk);
 915        sock_kzfree_s(sk, ctx->iv, crypto_skcipher_ivsize(tfm));
 916        sock_kfree_s(sk, ctx, ctx->len);
 917        af_alg_release_parent(sk);
 918}
 919
 920static int skcipher_accept_parent_nokey(void *private, struct sock *sk)
 921{
 922        struct skcipher_ctx *ctx;
 923        struct alg_sock *ask = alg_sk(sk);
 924        struct skcipher_tfm *tfm = private;
 925        struct crypto_skcipher *skcipher = tfm->skcipher;
 926        unsigned int len = sizeof(*ctx) + crypto_skcipher_reqsize(skcipher);
 927
 928        ctx = sock_kmalloc(sk, len, GFP_KERNEL);
 929        if (!ctx)
 930                return -ENOMEM;
 931
 932        ctx->iv = sock_kmalloc(sk, crypto_skcipher_ivsize(skcipher),
 933                               GFP_KERNEL);
 934        if (!ctx->iv) {
 935                sock_kfree_s(sk, ctx, len);
 936                return -ENOMEM;
 937        }
 938
 939        memset(ctx->iv, 0, crypto_skcipher_ivsize(skcipher));
 940
 941        INIT_LIST_HEAD(&ctx->tsgl);
 942        ctx->len = len;
 943        ctx->used = 0;
 944        ctx->more = 0;
 945        ctx->merge = 0;
 946        ctx->enc = 0;
 947        atomic_set(&ctx->inflight, 0);
 948        af_alg_init_completion(&ctx->completion);
 949
 950        ask->private = ctx;
 951
 952        skcipher_request_set_tfm(&ctx->req, skcipher);
 953        skcipher_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_SLEEP |
 954                                                 CRYPTO_TFM_REQ_MAY_BACKLOG,
 955                                      af_alg_complete, &ctx->completion);
 956
 957        sk->sk_destruct = skcipher_sock_destruct;
 958
 959        return 0;
 960}
 961
 962static int skcipher_accept_parent(void *private, struct sock *sk)
 963{
 964        struct skcipher_tfm *tfm = private;
 965
 966        if (!tfm->has_key && crypto_skcipher_has_setkey(tfm->skcipher))
 967                return -ENOKEY;
 968
 969        return skcipher_accept_parent_nokey(private, sk);
 970}
 971
 972static const struct af_alg_type algif_type_skcipher = {
 973        .bind           =       skcipher_bind,
 974        .release        =       skcipher_release,
 975        .setkey         =       skcipher_setkey,
 976        .accept         =       skcipher_accept_parent,
 977        .accept_nokey   =       skcipher_accept_parent_nokey,
 978        .ops            =       &algif_skcipher_ops,
 979        .ops_nokey      =       &algif_skcipher_ops_nokey,
 980        .name           =       "skcipher",
 981        .owner          =       THIS_MODULE
 982};
 983
 984static int __init algif_skcipher_init(void)
 985{
 986        return af_alg_register_type(&algif_type_skcipher);
 987}
 988
 989static void __exit algif_skcipher_exit(void)
 990{
 991        int err = af_alg_unregister_type(&algif_type_skcipher);
 992        BUG_ON(err);
 993}
 994
 995module_init(algif_skcipher_init);
 996module_exit(algif_skcipher_exit);
 997MODULE_LICENSE("GPL");
 998