crypto/af_alg.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * af_alg: User-space algorithm interface
   4  *
   5  * This file provides the user-space API for algorithms.
   6  *
   7  * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
   8  */
   9
  10 #include <linux/atomic.h>
  11 #include <crypto/if_alg.h>
  12 #include <linux/crypto.h>
  13 #include <linux/init.h>
  14 #include <linux/kernel.h>
  15 #include <linux/list.h>
  16 #include <linux/module.h>
  17 #include <linux/net.h>
  18 #include <linux/rwsem.h>
  19 #include <linux/sched/signal.h>
  20 #include <linux/security.h>
  21
  22 struct alg_type_list {
  23         const struct af_alg_type *type;
  24         struct list_head list;
  25 };
  26
  27 static atomic_long_t alg_memory_allocated;
  28
  29 static struct proto alg_proto = {
  30         .name                   = "ALG",
  31         .owner                  = THIS_MODULE,
  32         .memory_allocated       = &alg_memory_allocated,
  33         .obj_size               = sizeof(struct alg_sock),
  34 };
  35
  36 static LIST_HEAD(alg_types);
  37 static DECLARE_RWSEM(alg_types_sem);
  38
  39 static const struct af_alg_type *alg_get_type(const char *name)
  40 {
  41         const struct af_alg_type *type = ERR_PTR(-ENOENT);
  42         struct alg_type_list *node;
  43
  44         down_read(&alg_types_sem);
  45         list_for_each_entry(node, &alg_types, list) {
  46                 if (strcmp(node->type->name, name))
  47                         continue;
  48
  49                 if (try_module_get(node->type->owner))
  50                         type = node->type;
  51                 break;
  52         }
  53         up_read(&alg_types_sem);
  54
  55         return type;
  56 }
  57
  58 int af_alg_register_type(const struct af_alg_type *type)
  59 {
  60         struct alg_type_list *node;
  61         int err = -EEXIST;
  62
  63         down_write(&alg_types_sem);
  64         list_for_each_entry(node, &alg_types, list) {
  65                 if (!strcmp(node->type->name, type->name))
  66                         goto unlock;
  67         }
  68
  69         node = kmalloc(sizeof(*node), GFP_KERNEL);
  70         err = -ENOMEM;
  71         if (!node)
  72                 goto unlock;
  73
  74         type->ops->owner = THIS_MODULE;
  75         if (type->ops_nokey)
  76                 type->ops_nokey->owner = THIS_MODULE;
  77         node->type = type;
  78         list_add(&node->list, &alg_types);
  79         err = 0;
  80
  81 unlock:
  82         up_write(&alg_types_sem);
  83
  84         return err;
  85 }
  86 EXPORT_SYMBOL_GPL(af_alg_register_type);
  87
  88 int af_alg_unregister_type(const struct af_alg_type *type)
  89 {
  90         struct alg_type_list *node;
  91         int err = -ENOENT;
  92
  93         down_write(&alg_types_sem);
  94         list_for_each_entry(node, &alg_types, list) {
  95                 if (strcmp(node->type->name, type->name))
  96                         continue;
  97
  98                 list_del(&node->list);
  99                 kfree(node);
 100                 err = 0;
 101                 break;
 102         }
 103         up_write(&alg_types_sem);
 104
 105         return err;
 106 }
 107 EXPORT_SYMBOL_GPL(af_alg_unregister_type);
 108
 109 static void alg_do_release(const struct af_alg_type *type, void *private)
 110 {
 111         if (!type)
 112                 return;
 113
 114         type->release(private);
 115         module_put(type->owner);
 116 }
 117
 118 int af_alg_release(struct socket *sock)
 119 {
 120         if (sock->sk) {
 121                 sock_put(sock->sk);
 122                 sock->sk = NULL;
 123         }
 124         return 0;
 125 }
 126 EXPORT_SYMBOL_GPL(af_alg_release);
 127
 128 void af_alg_release_parent(struct sock *sk)
 129 {
 130         struct alg_sock *ask = alg_sk(sk);
 131         unsigned int nokey = atomic_read(&ask->nokey_refcnt);
 132
 133         sk = ask->parent;
 134         ask = alg_sk(sk);
 135
 136         if (nokey)
 137                 atomic_dec(&ask->nokey_refcnt);
 138
 139         if (atomic_dec_and_test(&ask->refcnt))
 140                 sock_put(sk);
 141 }
 142 EXPORT_SYMBOL_GPL(af_alg_release_parent);
 143
 144 static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 145 {
 146         const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY;
 147         struct sock *sk = sock->sk;
 148         struct alg_sock *ask = alg_sk(sk);
 149         struct sockaddr_alg *sa = (void *)uaddr;
 150         const struct af_alg_type *type;
 151         void *private;
 152         int err;
 153
 154         if (sock->state == SS_CONNECTED)
 155                 return -EINVAL;
 156
 157         if (addr_len < sizeof(*sa))
 158                 return -EINVAL;
 159
 160         /* If caller uses non-allowed flag, return error. */
 161         if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed))
 162                 return -EINVAL;
 163
 164         sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
 165         sa->salg_name[sizeof(sa->salg_name) + addr_len - sizeof(*sa) - 1] = 0;
 166
 167         type = alg_get_type(sa->salg_type);
 168         if (PTR_ERR(type) == -ENOENT) {
 169                 request_module("algif-%s", sa->salg_type);
 170                 type = alg_get_type(sa->salg_type);
 171         }
 172
 173         if (IS_ERR(type))
 174                 return PTR_ERR(type);
 175
 176         private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask);
 177         if (IS_ERR(private)) {
 178                 module_put(type->owner);
 179                 return PTR_ERR(private);
 180         }
 181
 182         err = -EBUSY;
 183         lock_sock(sk);
 184         if (atomic_read(&ask->refcnt))
 185                 goto unlock;
 186
 187         swap(ask->type, type);
 188         swap(ask->private, private);
 189
 190         err = 0;
 191
 192 unlock:
 193         release_sock(sk);
 194
 195         alg_do_release(type, private);
 196
 197         return err;
 198 }
 199
 200 static int alg_setkey(struct sock *sk, char __user *ukey,
 201                       unsigned int keylen)
 202 {
 203         struct alg_sock *ask = alg_sk(sk);
 204         const struct af_alg_type *type = ask->type;
 205         u8 *key;
 206         int err;
 207
 208         key = sock_kmalloc(sk, keylen, GFP_KERNEL);
 209         if (!key)
 210                 return -ENOMEM;
 211
 212         err = -EFAULT;
 213         if (copy_from_user(key, ukey, keylen))
 214                 goto out;
 215
 216         err = type->setkey(ask->private, key, keylen);
 217
 218 out:
 219         sock_kzfree_s(sk, key, keylen);
 220
 221         return err;
 222 }
 223
 224 static int alg_setsockopt(struct socket *sock, int level, int optname,
 225                           char __user *optval, unsigned int optlen)
 226 {
 227         struct sock *sk = sock->sk;
 228         struct alg_sock *ask = alg_sk(sk);
 229         const struct af_alg_type *type;
 230         int err = -EBUSY;
 231
 232         lock_sock(sk);
 233         if (atomic_read(&ask->refcnt) != atomic_read(&ask->nokey_refcnt))
 234                 goto unlock;
 235
 236         type = ask->type;
 237
 238         err = -ENOPROTOOPT;
 239         if (level != SOL_ALG || !type)
 240                 goto unlock;
 241
 242         switch (optname) {
 243         case ALG_SET_KEY:
 244                 if (sock->state == SS_CONNECTED)
 245                         goto unlock;
 246                 if (!type->setkey)
 247                         goto unlock;
 248
 249                 err = alg_setkey(sk, optval, optlen);
 250                 break;
 251         case ALG_SET_AEAD_AUTHSIZE:
 252                 if (sock->state == SS_CONNECTED)
 253                         goto unlock;
 254                 if (!type->setauthsize)
 255                         goto unlock;
 256                 err = type->setauthsize(ask->private, optlen);
 257         }
 258
 259 unlock:
 260         release_sock(sk);
 261
 262         return err;
 263 }
 264
 265 int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern)
 266 {
 267         struct alg_sock *ask = alg_sk(sk);
 268         const struct af_alg_type *type;
 269         struct sock *sk2;
 270         unsigned int nokey;
 271         int err;
 272
 273         lock_sock(sk);
 274         type = ask->type;
 275
 276         err = -EINVAL;
 277         if (!type)
 278                 goto unlock;
 279
 280         sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, kern);
 281         err = -ENOMEM;
 282         if (!sk2)
 283                 goto unlock;
 284
 285         sock_init_data(newsock, sk2);
 286         security_sock_graft(sk2, newsock);
 287         security_sk_clone(sk, sk2);
 288
 289         err = type->accept(ask->private, sk2);
 290
 291         nokey = err == -ENOKEY;
 292         if (nokey && type->accept_nokey)
 293                 err = type->accept_nokey(ask->private, sk2);
 294
 295         if (err)
 296                 goto unlock;
 297
 298         if (atomic_inc_return_relaxed(&ask->refcnt) == 1)
 299                 sock_hold(sk);
 300         if (nokey) {
 301                 atomic_inc(&ask->nokey_refcnt);
 302                 atomic_set(&alg_sk(sk2)->nokey_refcnt, 1);
 303         }
 304         alg_sk(sk2)->parent = sk;
 305         alg_sk(sk2)->type = type;
 306
 307         newsock->ops = type->ops;
 308         newsock->state = SS_CONNECTED;
 309
 310         if (nokey)
 311                 newsock->ops = type->ops_nokey;
 312
 313         err = 0;
 314
 315 unlock:
 316         release_sock(sk);
 317
 318         return err;
 319 }
 320 EXPORT_SYMBOL_GPL(af_alg_accept);
 321
 322 static int alg_accept(struct socket *sock, struct socket *newsock, int flags,
 323                       bool kern)
 324 {
 325         return af_alg_accept(sock->sk, newsock, kern);
 326 }
 327
 328 static const struct proto_ops alg_proto_ops = {
 329         .family         =       PF_ALG,
 330         .owner          =       THIS_MODULE,
 331
 332         .connect        =       sock_no_connect,
 333         .socketpair     =       sock_no_socketpair,
 334         .getname        =       sock_no_getname,
 335         .ioctl          =       sock_no_ioctl,
 336         .listen         =       sock_no_listen,
 337         .shutdown       =       sock_no_shutdown,
 338         .getsockopt     =       sock_no_getsockopt,
 339         .mmap           =       sock_no_mmap,
 340         .sendpage       =       sock_no_sendpage,
 341         .sendmsg        =       sock_no_sendmsg,
 342         .recvmsg        =       sock_no_recvmsg,
 343
 344         .bind           =       alg_bind,
 345         .release        =       af_alg_release,
 346         .setsockopt     =       alg_setsockopt,
 347         .accept         =       alg_accept,
 348 };
 349
 350 static void alg_sock_destruct(struct sock *sk)
 351 {
 352         struct alg_sock *ask = alg_sk(sk);
 353
 354         alg_do_release(ask->type, ask->private);
 355 }
 356
 357 static int alg_create(struct net *net, struct socket *sock, int protocol,
 358                       int kern)
 359 {
 360         struct sock *sk;
 361         int err;
 362
 363         if (sock->type != SOCK_SEQPACKET)
 364                 return -ESOCKTNOSUPPORT;
 365         if (protocol != 0)
 366                 return -EPROTONOSUPPORT;
 367
 368         err = -ENOMEM;
 369         sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
 370         if (!sk)
 371                 goto out;
 372
 373         sock->ops = &alg_proto_ops;
 374         sock_init_data(sock, sk);
 375
 376         sk->sk_destruct = alg_sock_destruct;
 377
 378         return 0;
 379 out:
 380         return err;
 381 }
 382
 383 static const struct net_proto_family alg_family = {
 384         .family =       PF_ALG,
 385         .create =       alg_create,
 386         .owner  =       THIS_MODULE,
 387 };
 388
 389 int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
 390 {
 391         size_t off;
 392         ssize_t n;
 393         int npages, i;
 394
 395         n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
 396         if (n < 0)
 397                 return n;
 398
 399         npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT;
 400         if (WARN_ON(npages == 0))
 401                 return -EINVAL;
 402         /* Add one extra for linking */
 403         sg_init_table(sgl->sg, npages + 1);
 404
 405         for (i = 0, len = n; i < npages; i++) {
 406                 int plen = min_t(int, len, PAGE_SIZE - off);
 407
 408                 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
 409
 410                 off = 0;
 411                 len -= plen;
 412         }
 413         sg_mark_end(sgl->sg + npages - 1);
 414         sgl->npages = npages;
 415
 416         return n;
 417 }
 418 EXPORT_SYMBOL_GPL(af_alg_make_sg);
 419
 420 static void af_alg_link_sg(struct af_alg_sgl *sgl_prev,
 421                            struct af_alg_sgl *sgl_new)
 422 {
 423         sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
 424         sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
 425 }
 426
 427 void af_alg_free_sg(struct af_alg_sgl *sgl)
 428 {
 429         int i;
 430
 431         for (i = 0; i < sgl->npages; i++)
 432                 put_page(sgl->pages[i]);
 433 }
 434 EXPORT_SYMBOL_GPL(af_alg_free_sg);
 435
 436 static int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
 437 {
 438         struct cmsghdr *cmsg;
 439
 440         for_each_cmsghdr(cmsg, msg) {
 441                 if (!CMSG_OK(msg, cmsg))
 442                         return -EINVAL;
 443                 if (cmsg->cmsg_level != SOL_ALG)
 444                         continue;
 445
 446                 switch (cmsg->cmsg_type) {
 447                 case ALG_SET_IV:
 448                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
 449                                 return -EINVAL;
 450                         con->iv = (void *)CMSG_DATA(cmsg);
 451                         if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
 452                                                       sizeof(*con->iv)))
 453                                 return -EINVAL;
 454                         break;
 455
 456                 case ALG_SET_OP:
 457                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
 458                                 return -EINVAL;
 459                         con->op = *(u32 *)CMSG_DATA(cmsg);
 460                         break;
 461
 462                 case ALG_SET_AEAD_ASSOCLEN:
 463                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
 464                                 return -EINVAL;
 465                         con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
 466                         break;
 467
 468                 default:
 469                         return -EINVAL;
 470                 }
 471         }
 472
 473         return 0;
 474 }
 475
 476 /**
 477  * af_alg_alloc_tsgl - allocate the TX SGL
 478  *
 479  * @sk socket of connection to user space
 480  * @return: 0 upon success, < 0 upon error
 481  */
 482 static int af_alg_alloc_tsgl(struct sock *sk)
 483 {
 484         struct alg_sock *ask = alg_sk(sk);
 485         struct af_alg_ctx *ctx = ask->private;
 486         struct af_alg_tsgl *sgl;
 487         struct scatterlist *sg = NULL;
 488
 489         sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
 490         if (!list_empty(&ctx->tsgl_list))
 491                 sg = sgl->sg;
 492
 493         if (!sg || sgl->cur >= MAX_SGL_ENTS) {
 494                 sgl = sock_kmalloc(sk,
 495                                    struct_size(sgl, sg, (MAX_SGL_ENTS + 1)),
 496                                    GFP_KERNEL);
 497                 if (!sgl)
 498                         return -ENOMEM;
 499
 500                 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
 501                 sgl->cur = 0;
 502
 503                 if (sg)
 504                         sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
 505
 506                 list_add_tail(&sgl->list, &ctx->tsgl_list);
 507         }
 508
 509         return 0;
 510 }
 511
 512 /**
 513  * aead_count_tsgl - Count number of TX SG entries
 514  *
 515  * The counting starts from the beginning of the SGL to @bytes. If
 516  * an offset is provided, the counting of the SG entries starts at the offset.
 517  *
 518  * @sk socket of connection to user space
 519  * @bytes Count the number of SG entries holding given number of bytes.
 520  * @offset Start the counting of SG entries from the given offset.
 521  * @return Number of TX SG entries found given the constraints
 522  */
 523 unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
 524 {
 525         const struct alg_sock *ask = alg_sk(sk);
 526         const struct af_alg_ctx *ctx = ask->private;
 527         const struct af_alg_tsgl *sgl;
 528         unsigned int i;
 529         unsigned int sgl_count = 0;
 530
 531         if (!bytes)
 532                 return 0;
 533
 534         list_for_each_entry(sgl, &ctx->tsgl_list, list) {
 535                 const struct scatterlist *sg = sgl->sg;
 536
 537                 for (i = 0; i < sgl->cur; i++) {
 538                         size_t bytes_count;
 539
 540                         /* Skip offset */
 541                         if (offset >= sg[i].length) {
 542                                 offset -= sg[i].length;
 543                                 bytes -= sg[i].length;
 544                                 continue;
 545                         }
 546
 547                         bytes_count = sg[i].length - offset;
 548
 549                         offset = 0;
 550                         sgl_count++;
 551
 552                         /* If we have seen requested number of bytes, stop */
 553                         if (bytes_count >= bytes)
 554                                 return sgl_count;
 555
 556                         bytes -= bytes_count;
 557                 }
 558         }
 559
 560         return sgl_count;
 561 }
 562 EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
 563
 564 /**
 565  * aead_pull_tsgl - Release the specified buffers from TX SGL
 566  *
 567  * If @dst is non-null, reassign the pages to dst. The caller must release
 568  * the pages. If @dst_offset is given only reassign the pages to @dst starting
 569  * at the @dst_offset (byte). The caller must ensure that @dst is large
 570  * enough (e.g. by using af_alg_count_tsgl with the same offset).
 571  *
 572  * @sk socket of connection to user space
 573  * @used Number of bytes to pull from TX SGL
 574  * @dst If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
 575  *      caller must release the buffers in dst.
 576  * @dst_offset Reassign the TX SGL from given offset. All buffers before
 577  *             reaching the offset is released.
 578  */
 579 void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
 580                       size_t dst_offset)
 581 {
 582         struct alg_sock *ask = alg_sk(sk);
 583         struct af_alg_ctx *ctx = ask->private;
 584         struct af_alg_tsgl *sgl;
 585         struct scatterlist *sg;
 586         unsigned int i, j = 0;
 587
 588         while (!list_empty(&ctx->tsgl_list)) {
 589                 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
 590                                        list);
 591                 sg = sgl->sg;
 592
 593                 for (i = 0; i < sgl->cur; i++) {
 594                         size_t plen = min_t(size_t, used, sg[i].length);
 595                         struct page *page = sg_page(sg + i);
 596
 597                         if (!page)
 598                                 continue;
 599
 600                         /*
 601                          * Assumption: caller created af_alg_count_tsgl(len)
 602                          * SG entries in dst.
 603                          */
 604                         if (dst) {
 605                                 if (dst_offset >= plen) {
 606                                         /* discard page before offset */
 607                                         dst_offset -= plen;
 608                                 } else {
 609                                         /* reassign page to dst after offset */
 610                                         get_page(page);
 611                                         sg_set_page(dst + j, page,
 612                                                     plen - dst_offset,
 613                                                     sg[i].offset + dst_offset);
 614                                         dst_offset = 0;
 615                                         j++;
 616                                 }
 617                         }
 618
 619                         sg[i].length -= plen;
 620                         sg[i].offset += plen;
 621
 622                         used -= plen;
 623                         ctx->used -= plen;
 624
 625                         if (sg[i].length)
 626                                 return;
 627
 628                         put_page(page);
 629                         sg_assign_page(sg + i, NULL);
 630                 }
 631
 632                 list_del(&sgl->list);
 633                 sock_kfree_s(sk, sgl, struct_size(sgl, sg, MAX_SGL_ENTS + 1));
 634         }
 635
 636         if (!ctx->used)
 637                 ctx->merge = 0;
 638 }
 639 EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
 640
 641 /**
 642  * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
 643  *
 644  * @areq Request holding the TX and RX SGL
 645  */
 646 static void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
 647 {
 648         struct sock *sk = areq->sk;
 649         struct alg_sock *ask = alg_sk(sk);
 650         struct af_alg_ctx *ctx = ask->private;
 651         struct af_alg_rsgl *rsgl, *tmp;
 652         struct scatterlist *tsgl;
 653         struct scatterlist *sg;
 654         unsigned int i;
 655
 656         list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
 657                 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
 658                 af_alg_free_sg(&rsgl->sgl);
 659                 list_del(&rsgl->list);
 660                 if (rsgl != &areq->first_rsgl)
 661                         sock_kfree_s(sk, rsgl, sizeof(*rsgl));
 662         }
 663
 664         tsgl = areq->tsgl;
 665         if (tsgl) {
 666                 for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
 667                         if (!sg_page(sg))
 668                                 continue;
 669                         put_page(sg_page(sg));
 670                 }
 671
 672                 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
 673         }
 674 }
 675
 676 /**
 677  * af_alg_wait_for_wmem - wait for availability of writable memory
 678  *
 679  * @sk socket of connection to user space
 680  * @flags If MSG_DONTWAIT is set, then only report if function would sleep
 681  * @return 0 when writable memory is available, < 0 upon error
 682  */
 683 static int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
 684 {
 685         DEFINE_WAIT_FUNC(wait, woken_wake_function);
 686         int err = -ERESTARTSYS;
 687         long timeout;
 688
 689         if (flags & MSG_DONTWAIT)
 690                 return -EAGAIN;
 691
 692         sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 693
 694         add_wait_queue(sk_sleep(sk), &wait);
 695         for (;;) {
 696                 if (signal_pending(current))
 697                         break;
 698                 timeout = MAX_SCHEDULE_TIMEOUT;
 699                 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
 700                         err = 0;
 701                         break;
 702                 }
 703         }
 704         remove_wait_queue(sk_sleep(sk), &wait);
 705
 706         return err;
 707 }
 708
 709 /**
 710  * af_alg_wmem_wakeup - wakeup caller when writable memory is available
 711  *
 712  * @sk socket of connection to user space
 713  */
 714 void af_alg_wmem_wakeup(struct sock *sk)
 715 {
 716         struct socket_wq *wq;
 717
 718         if (!af_alg_writable(sk))
 719                 return;
 720
 721         rcu_read_lock();
 722         wq = rcu_dereference(sk->sk_wq);
 723         if (skwq_has_sleeper(wq))
 724                 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN |
 725                                                            EPOLLRDNORM |
 726                                                            EPOLLRDBAND);
 727         sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
 728         rcu_read_unlock();
 729 }
 730 EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
 731
 732 /**
 733  * af_alg_wait_for_data - wait for availability of TX data
 734  *
 735  * @sk socket of connection to user space
 736  * @flags If MSG_DONTWAIT is set, then only report if function would sleep
 737  * @return 0 when writable memory is available, < 0 upon error
 738  */
 739 int af_alg_wait_for_data(struct sock *sk, unsigned flags)
 740 {
 741         DEFINE_WAIT_FUNC(wait, woken_wake_function);
 742         struct alg_sock *ask = alg_sk(sk);
 743         struct af_alg_ctx *ctx = ask->private;
 744         long timeout;
 745         int err = -ERESTARTSYS;
 746
 747         if (flags & MSG_DONTWAIT)
 748                 return -EAGAIN;
 749
 750         sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
 751
 752         add_wait_queue(sk_sleep(sk), &wait);
 753         for (;;) {
 754                 if (signal_pending(current))
 755                         break;
 756                 timeout = MAX_SCHEDULE_TIMEOUT;
 757                 if (sk_wait_event(sk, &timeout, (ctx->used || !ctx->more),
 758                                   &wait)) {
 759                         err = 0;
 760                         break;
 761                 }
 762         }
 763         remove_wait_queue(sk_sleep(sk), &wait);
 764
 765         sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
 766
 767         return err;
 768 }
 769 EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
 770
 771 /**
 772  * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
 773  *
 774  * @sk socket of connection to user space
 775  */
 776 static void af_alg_data_wakeup(struct sock *sk)
 777 {
 778         struct alg_sock *ask = alg_sk(sk);
 779         struct af_alg_ctx *ctx = ask->private;
 780         struct socket_wq *wq;
 781
 782         if (!ctx->used)
 783                 return;
 784
 785         rcu_read_lock();
 786         wq = rcu_dereference(sk->sk_wq);
 787         if (skwq_has_sleeper(wq))
 788                 wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
 789                                                            EPOLLRDNORM |
 790                                                            EPOLLRDBAND);
 791         sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
 792         rcu_read_unlock();
 793 }
 794
 795 /**
 796  * af_alg_sendmsg - implementation of sendmsg system call handler
 797  *
 798  * The sendmsg system call handler obtains the user data and stores it
 799  * in ctx->tsgl_list. This implies allocation of the required numbers of
 800  * struct af_alg_tsgl.
 801  *
 802  * In addition, the ctx is filled with the information sent via CMSG.
 803  *
 804  * @sock socket of connection to user space
 805  * @msg message from user space
 806  * @size size of message from user space
 807  * @ivsize the size of the IV for the cipher operation to verify that the
 808  *         user-space-provided IV has the right size
 809  * @return the number of copied data upon success, < 0 upon error
 810  */
 811 int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
 812                    unsigned int ivsize)
 813 {
 814         struct sock *sk = sock->sk;
 815         struct alg_sock *ask = alg_sk(sk);
 816         struct af_alg_ctx *ctx = ask->private;
 817         struct af_alg_tsgl *sgl;
 818         struct af_alg_control con = {};
 819         long copied = 0;
 820         bool enc = false;
 821         bool init = false;
 822         int err = 0;
 823
 824         if (msg->msg_controllen) {
 825                 err = af_alg_cmsg_send(msg, &con);
 826                 if (err)
 827                         return err;
 828
 829                 init = true;
 830                 switch (con.op) {
 831                 case ALG_OP_ENCRYPT:
 832                         enc = true;
 833                         break;
 834                 case ALG_OP_DECRYPT:
 835                         enc = false;
 836                         break;
 837                 default:
 838                         return -EINVAL;
 839                 }
 840
 841                 if (con.iv && con.iv->ivlen != ivsize)
 842                         return -EINVAL;
 843         }
 844
 845         lock_sock(sk);
 846         if (!ctx->more && ctx->used) {
 847                 err = -EINVAL;
 848                 goto unlock;
 849         }
 850
 851         if (init) {
 852                 ctx->enc = enc;
 853                 if (con.iv)
 854                         memcpy(ctx->iv, con.iv->iv, ivsize);
 855
 856                 ctx->aead_assoclen = con.aead_assoclen;
 857         }
 858
 859         while (size) {
 860                 struct scatterlist *sg;
 861                 size_t len = size;
 862                 size_t plen;
 863
 864                 /* use the existing memory in an allocated page */
 865                 if (ctx->merge) {
 866                         sgl = list_entry(ctx->tsgl_list.prev,
 867                                          struct af_alg_tsgl, list);
 868                         sg = sgl->sg + sgl->cur - 1;
 869                         len = min_t(size_t, len,
 870                                     PAGE_SIZE - sg->offset - sg->length);
 871
 872                         err = memcpy_from_msg(page_address(sg_page(sg)) +
 873                                               sg->offset + sg->length,
 874                                               msg, len);
 875                         if (err)
 876                                 goto unlock;
 877
 878                         sg->length += len;
 879                         ctx->merge = (sg->offset + sg->length) &
 880                                      (PAGE_SIZE - 1);
 881
 882                         ctx->used += len;
 883                         copied += len;
 884                         size -= len;
 885                         continue;
 886                 }
 887
 888                 if (!af_alg_writable(sk)) {
 889                         err = af_alg_wait_for_wmem(sk, msg->msg_flags);
 890                         if (err)
 891                                 goto unlock;
 892                 }
 893
 894                 /* allocate a new page */
 895                 len = min_t(unsigned long, len, af_alg_sndbuf(sk));
 896
 897                 err = af_alg_alloc_tsgl(sk);
 898                 if (err)
 899                         goto unlock;
 900
 901                 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
 902                                  list);
 903                 sg = sgl->sg;
 904                 if (sgl->cur)
 905                         sg_unmark_end(sg + sgl->cur - 1);
 906
 907                 do {
 908                         unsigned int i = sgl->cur;
 909
 910                         plen = min_t(size_t, len, PAGE_SIZE);
 911
 912                         sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
 913                         if (!sg_page(sg + i)) {
 914                                 err = -ENOMEM;
 915                                 goto unlock;
 916                         }
 917
 918                         err = memcpy_from_msg(page_address(sg_page(sg + i)),
 919                                               msg, plen);
 920                         if (err) {
 921                                 __free_page(sg_page(sg + i));
 922                                 sg_assign_page(sg + i, NULL);
 923                                 goto unlock;
 924                         }
 925
 926                         sg[i].length = plen;
 927                         len -= plen;
 928                         ctx->used += plen;
 929                         copied += plen;
 930                         size -= plen;
 931                         sgl->cur++;
 932                 } while (len && sgl->cur < MAX_SGL_ENTS);
 933
 934                 if (!size)
 935                         sg_mark_end(sg + sgl->cur - 1);
 936
 937                 ctx->merge = plen & (PAGE_SIZE - 1);
 938         }
 939
 940         err = 0;
 941
 942         ctx->more = msg->msg_flags & MSG_MORE;
 943
 944 unlock:
 945         af_alg_data_wakeup(sk);
 946         release_sock(sk);
 947
 948         return copied ?: err;
 949 }
 950 EXPORT_SYMBOL_GPL(af_alg_sendmsg);
 951
 952 /**
 953  * af_alg_sendpage - sendpage system call handler
 954  *
 955  * This is a generic implementation of sendpage to fill ctx->tsgl_list.
 956  */
 957 ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
 958                         int offset, size_t size, int flags)
 959 {
 960         struct sock *sk = sock->sk;
 961         struct alg_sock *ask = alg_sk(sk);
 962         struct af_alg_ctx *ctx = ask->private;
 963         struct af_alg_tsgl *sgl;
 964         int err = -EINVAL;
 965
 966         if (flags & MSG_SENDPAGE_NOTLAST)
 967                 flags |= MSG_MORE;
 968
 969         lock_sock(sk);
 970         if (!ctx->more && ctx->used)
 971                 goto unlock;
 972
 973         if (!size)
 974                 goto done;
 975
 976         if (!af_alg_writable(sk)) {
 977                 err = af_alg_wait_for_wmem(sk, flags);
 978                 if (err)
 979                         goto unlock;
 980         }
 981
 982         err = af_alg_alloc_tsgl(sk);
 983         if (err)
 984                 goto unlock;
 985
 986         ctx->merge = 0;
 987         sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
 988
 989         if (sgl->cur)
 990                 sg_unmark_end(sgl->sg + sgl->cur - 1);
 991
 992         sg_mark_end(sgl->sg + sgl->cur);
 993
 994         get_page(page);
 995         sg_set_page(sgl->sg + sgl->cur, page, size, offset);
 996         sgl->cur++;
 997         ctx->used += size;
 998
 999 done:
1000         ctx->more = flags & MSG_MORE;
1001
1002 unlock:
1003         af_alg_data_wakeup(sk);
1004         release_sock(sk);
1005
1006         return err ?: size;
1007 }
1008 EXPORT_SYMBOL_GPL(af_alg_sendpage);
1009
1010 /**
1011  * af_alg_free_resources - release resources required for crypto request
1012  */
1013 void af_alg_free_resources(struct af_alg_async_req *areq)
1014 {
1015         struct sock *sk = areq->sk;
1016
1017         af_alg_free_areq_sgls(areq);
1018         sock_kfree_s(sk, areq, areq->areqlen);
1019 }
1020 EXPORT_SYMBOL_GPL(af_alg_free_resources);
1021
1022 /**
1023  * af_alg_async_cb - AIO callback handler
1024  *
1025  * This handler cleans up the struct af_alg_async_req upon completion of the
1026  * AIO operation.
1027  *
1028  * The number of bytes to be generated with the AIO operation must be set
1029  * in areq->outlen before the AIO callback handler is invoked.
1030  */
1031 void af_alg_async_cb(struct crypto_async_request *_req, int err)
1032 {
1033         struct af_alg_async_req *areq = _req->data;
1034         struct sock *sk = areq->sk;
1035         struct kiocb *iocb = areq->iocb;
1036         unsigned int resultlen;
1037
1038         /* Buffer size written by crypto operation. */
1039         resultlen = areq->outlen;
1040
1041         af_alg_free_resources(areq);
1042         sock_put(sk);
1043
1044         iocb->ki_complete(iocb, err ? err : (int)resultlen, 0);
1045 }
1046 EXPORT_SYMBOL_GPL(af_alg_async_cb);
1047
1048 /**
1049  * af_alg_poll - poll system call handler
1050  */
1051 __poll_t af_alg_poll(struct file *file, struct socket *sock,
1052                          poll_table *wait)
1053 {
1054         struct sock *sk = sock->sk;
1055         struct alg_sock *ask = alg_sk(sk);
1056         struct af_alg_ctx *ctx = ask->private;
1057         __poll_t mask;
1058
1059         sock_poll_wait(file, sock, wait);
1060         mask = 0;
1061
1062         if (!ctx->more || ctx->used)
1063                 mask |= EPOLLIN | EPOLLRDNORM;
1064
1065         if (af_alg_writable(sk))
1066                 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1067
1068         return mask;
1069 }
1070 EXPORT_SYMBOL_GPL(af_alg_poll);
1071
1072 /**
1073  * af_alg_alloc_areq - allocate struct af_alg_async_req
1074  *
1075  * @sk socket of connection to user space
1076  * @areqlen size of struct af_alg_async_req + crypto_*_reqsize
1077  * @return allocated data structure or ERR_PTR upon error
1078  */
1079 struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
1080                                            unsigned int areqlen)
1081 {
1082         struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
1083
1084         if (unlikely(!areq))
1085                 return ERR_PTR(-ENOMEM);
1086
1087         areq->areqlen = areqlen;
1088         areq->sk = sk;
1089         areq->last_rsgl = NULL;
1090         INIT_LIST_HEAD(&areq->rsgl_list);
1091         areq->tsgl = NULL;
1092         areq->tsgl_entries = 0;
1093
1094         return areq;
1095 }
1096 EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
1097
1098 /**
1099  * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1100  *                   operation
1101  *
1102  * @sk socket of connection to user space
1103  * @msg user space message
1104  * @flags flags used to invoke recvmsg with
1105  * @areq instance of the cryptographic request that will hold the RX SGL
1106  * @maxsize maximum number of bytes to be pulled from user space
1107  * @outlen number of bytes in the RX SGL
1108  * @return 0 on success, < 0 upon error
1109  */
1110 int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
1111                     struct af_alg_async_req *areq, size_t maxsize,
1112                     size_t *outlen)
1113 {
1114         struct alg_sock *ask = alg_sk(sk);
1115         struct af_alg_ctx *ctx = ask->private;
1116         size_t len = 0;
1117
1118         while (maxsize > len && msg_data_left(msg)) {
1119                 struct af_alg_rsgl *rsgl;
1120                 size_t seglen;
1121                 int err;
1122
1123                 /* limit the amount of readable buffers */
1124                 if (!af_alg_readable(sk))
1125                         break;
1126
1127                 seglen = min_t(size_t, (maxsize - len),
1128                                msg_data_left(msg));
1129
1130                 if (list_empty(&areq->rsgl_list)) {
1131                         rsgl = &areq->first_rsgl;
1132                 } else {
1133                         rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
1134                         if (unlikely(!rsgl))
1135                                 return -ENOMEM;
1136                 }
1137
1138                 rsgl->sgl.npages = 0;
1139                 list_add_tail(&rsgl->list, &areq->rsgl_list);
1140
1141                 /* make one iovec available as scatterlist */
1142                 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
1143                 if (err < 0) {
1144                         rsgl->sg_num_bytes = 0;
1145                         return err;
1146                 }
1147
1148                 /* chain the new scatterlist with previous one */
1149                 if (areq->last_rsgl)
1150                         af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
1151
1152                 areq->last_rsgl = rsgl;
1153                 len += err;
1154                 atomic_add(err, &ctx->rcvused);
1155                 rsgl->sg_num_bytes = err;
1156                 iov_iter_advance(&msg->msg_iter, err);
1157         }
1158
1159         *outlen = len;
1160         return 0;
1161 }
1162 EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
1163
1164 static int __init af_alg_init(void)
1165 {
1166         int err = proto_register(&alg_proto, 0);
1167
1168         if (err)
1169                 goto out;
1170
1171         err = sock_register(&alg_family);
1172         if (err != 0)
1173                 goto out_unregister_proto;
1174
1175 out:
1176         return err;
1177
1178 out_unregister_proto:
1179         proto_unregister(&alg_proto);
1180         goto out;
1181 }
1182
1183 static void __exit af_alg_exit(void)
1184 {
1185         sock_unregister(PF_ALG);
1186         proto_unregister(&alg_proto);
1187 }
1188
1189 module_init(af_alg_init);
1190 module_exit(af_alg_exit);
1191 MODULE_LICENSE("GPL");
1192 MODULE_ALIAS_NETPROTO(AF_ALG);