crypto/af_alg.c

   1 /*
   2  * af_alg: User-space algorithm interface
   3  *
   4  * This file provides the user-space API for algorithms.
   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 <linux/atomic.h>
  16 #include <crypto/if_alg.h>
  17 #include <linux/crypto.h>
  18 #include <linux/init.h>
  19 #include <linux/kernel.h>
  20 #include <linux/list.h>
  21 #include <linux/module.h>
  22 #include <linux/net.h>
  23 #include <linux/rwsem.h>
  24 #include <linux/sched/signal.h>
  25 #include <linux/security.h>
  26
  27 struct alg_type_list {
  28         const struct af_alg_type *type;
  29         struct list_head list;
  30 };
  31
  32 static atomic_long_t alg_memory_allocated;
  33
  34 static struct proto alg_proto = {
  35         .name                   = "ALG",
  36         .owner                  = THIS_MODULE,
  37         .memory_allocated       = &alg_memory_allocated,
  38         .obj_size               = sizeof(struct alg_sock),
  39 };
  40
  41 static LIST_HEAD(alg_types);
  42 static DECLARE_RWSEM(alg_types_sem);
  43
  44 static const struct af_alg_type *alg_get_type(const char *name)
  45 {
  46         const struct af_alg_type *type = ERR_PTR(-ENOENT);
  47         struct alg_type_list *node;
  48
  49         down_read(&alg_types_sem);
  50         list_for_each_entry(node, &alg_types, list) {
  51                 if (strcmp(node->type->name, name))
  52                         continue;
  53
  54                 if (try_module_get(node->type->owner))
  55                         type = node->type;
  56                 break;
  57         }
  58         up_read(&alg_types_sem);
  59
  60         return type;
  61 }
  62
  63 int af_alg_register_type(const struct af_alg_type *type)
  64 {
  65         struct alg_type_list *node;
  66         int err = -EEXIST;
  67
  68         down_write(&alg_types_sem);
  69         list_for_each_entry(node, &alg_types, list) {
  70                 if (!strcmp(node->type->name, type->name))
  71                         goto unlock;
  72         }
  73
  74         node = kmalloc(sizeof(*node), GFP_KERNEL);
  75         err = -ENOMEM;
  76         if (!node)
  77                 goto unlock;
  78
  79         type->ops->owner = THIS_MODULE;
  80         if (type->ops_nokey)
  81                 type->ops_nokey->owner = THIS_MODULE;
  82         node->type = type;
  83         list_add(&node->list, &alg_types);
  84         err = 0;
  85
  86 unlock:
  87         up_write(&alg_types_sem);
  88
  89         return err;
  90 }
  91 EXPORT_SYMBOL_GPL(af_alg_register_type);
  92
  93 int af_alg_unregister_type(const struct af_alg_type *type)
  94 {
  95         struct alg_type_list *node;
  96         int err = -ENOENT;
  97
  98         down_write(&alg_types_sem);
  99         list_for_each_entry(node, &alg_types, list) {
 100                 if (strcmp(node->type->name, type->name))
 101                         continue;
 102
 103                 list_del(&node->list);
 104                 kfree(node);
 105                 err = 0;
 106                 break;
 107         }
 108         up_write(&alg_types_sem);
 109
 110         return err;
 111 }
 112 EXPORT_SYMBOL_GPL(af_alg_unregister_type);
 113
 114 static void alg_do_release(const struct af_alg_type *type, void *private)
 115 {
 116         if (!type)
 117                 return;
 118
 119         type->release(private);
 120         module_put(type->owner);
 121 }
 122
 123 int af_alg_release(struct socket *sock)
 124 {
 125         if (sock->sk)
 126                 sock_put(sock->sk);
 127         return 0;
 128 }
 129 EXPORT_SYMBOL_GPL(af_alg_release);
 130
 131 void af_alg_release_parent(struct sock *sk)
 132 {
 133         struct alg_sock *ask = alg_sk(sk);
 134         unsigned int nokey = ask->nokey_refcnt;
 135         bool last = nokey && !ask->refcnt;
 136
 137         sk = ask->parent;
 138         ask = alg_sk(sk);
 139
 140         lock_sock(sk);
 141         ask->nokey_refcnt -= nokey;
 142         if (!last)
 143                 last = !--ask->refcnt;
 144         release_sock(sk);
 145
 146         if (last)
 147                 sock_put(sk);
 148 }
 149 EXPORT_SYMBOL_GPL(af_alg_release_parent);
 150
 151 static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 152 {
 153         const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY;
 154         struct sock *sk = sock->sk;
 155         struct alg_sock *ask = alg_sk(sk);
 156         struct sockaddr_alg *sa = (void *)uaddr;
 157         const struct af_alg_type *type;
 158         void *private;
 159         int err;
 160
 161         if (sock->state == SS_CONNECTED)
 162                 return -EINVAL;
 163
 164         if (addr_len < sizeof(*sa))
 165                 return -EINVAL;
 166
 167         /* If caller uses non-allowed flag, return error. */
 168         if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed))
 169                 return -EINVAL;
 170
 171         sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
 172         sa->salg_name[sizeof(sa->salg_name) + addr_len - sizeof(*sa) - 1] = 0;
 173
 174         type = alg_get_type(sa->salg_type);
 175         if (IS_ERR(type) && PTR_ERR(type) == -ENOENT) {
 176                 request_module("algif-%s", sa->salg_type);
 177                 type = alg_get_type(sa->salg_type);
 178         }
 179
 180         if (IS_ERR(type))
 181                 return PTR_ERR(type);
 182
 183         private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask);
 184         if (IS_ERR(private)) {
 185                 module_put(type->owner);
 186                 return PTR_ERR(private);
 187         }
 188
 189         err = -EBUSY;
 190         lock_sock(sk);
 191         if (ask->refcnt | ask->nokey_refcnt)
 192                 goto unlock;
 193
 194         swap(ask->type, type);
 195         swap(ask->private, private);
 196
 197         err = 0;
 198
 199 unlock:
 200         release_sock(sk);
 201
 202         alg_do_release(type, private);
 203
 204         return err;
 205 }
 206
 207 static int alg_setkey(struct sock *sk, char __user *ukey,
 208                       unsigned int keylen)
 209 {
 210         struct alg_sock *ask = alg_sk(sk);
 211         const struct af_alg_type *type = ask->type;
 212         u8 *key;
 213         int err;
 214
 215         key = sock_kmalloc(sk, keylen, GFP_KERNEL);
 216         if (!key)
 217                 return -ENOMEM;
 218
 219         err = -EFAULT;
 220         if (copy_from_user(key, ukey, keylen))
 221                 goto out;
 222
 223         err = type->setkey(ask->private, key, keylen);
 224
 225 out:
 226         sock_kzfree_s(sk, key, keylen);
 227
 228         return err;
 229 }
 230
 231 static int alg_setsockopt(struct socket *sock, int level, int optname,
 232                           char __user *optval, unsigned int optlen)
 233 {
 234         struct sock *sk = sock->sk;
 235         struct alg_sock *ask = alg_sk(sk);
 236         const struct af_alg_type *type;
 237         int err = -EBUSY;
 238
 239         lock_sock(sk);
 240         if (ask->refcnt)
 241                 goto unlock;
 242
 243         type = ask->type;
 244
 245         err = -ENOPROTOOPT;
 246         if (level != SOL_ALG || !type)
 247                 goto unlock;
 248
 249         switch (optname) {
 250         case ALG_SET_KEY:
 251                 if (sock->state == SS_CONNECTED)
 252                         goto unlock;
 253                 if (!type->setkey)
 254                         goto unlock;
 255
 256                 err = alg_setkey(sk, optval, optlen);
 257                 break;
 258         case ALG_SET_AEAD_AUTHSIZE:
 259                 if (sock->state == SS_CONNECTED)
 260                         goto unlock;
 261                 if (!type->setauthsize)
 262                         goto unlock;
 263                 err = type->setauthsize(ask->private, optlen);
 264         }
 265
 266 unlock:
 267         release_sock(sk);
 268
 269         return err;
 270 }
 271
 272 int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern)
 273 {
 274         struct alg_sock *ask = alg_sk(sk);
 275         const struct af_alg_type *type;
 276         struct sock *sk2;
 277         unsigned int nokey;
 278         int err;
 279
 280         lock_sock(sk);
 281         type = ask->type;
 282
 283         err = -EINVAL;
 284         if (!type)
 285                 goto unlock;
 286
 287         sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, kern);
 288         err = -ENOMEM;
 289         if (!sk2)
 290                 goto unlock;
 291
 292         sock_init_data(newsock, sk2);
 293         security_sock_graft(sk2, newsock);
 294         security_sk_clone(sk, sk2);
 295
 296         err = type->accept(ask->private, sk2);
 297
 298         nokey = err == -ENOKEY;
 299         if (nokey && type->accept_nokey)
 300                 err = type->accept_nokey(ask->private, sk2);
 301
 302         if (err)
 303                 goto unlock;
 304
 305         sk2->sk_family = PF_ALG;
 306
 307         if (nokey || !ask->refcnt++)
 308                 sock_hold(sk);
 309         ask->nokey_refcnt += nokey;
 310         alg_sk(sk2)->parent = sk;
 311         alg_sk(sk2)->type = type;
 312         alg_sk(sk2)->nokey_refcnt = nokey;
 313
 314         newsock->ops = type->ops;
 315         newsock->state = SS_CONNECTED;
 316
 317         if (nokey)
 318                 newsock->ops = type->ops_nokey;
 319
 320         err = 0;
 321
 322 unlock:
 323         release_sock(sk);
 324
 325         return err;
 326 }
 327 EXPORT_SYMBOL_GPL(af_alg_accept);
 328
 329 static int alg_accept(struct socket *sock, struct socket *newsock, int flags,
 330                       bool kern)
 331 {
 332         return af_alg_accept(sock->sk, newsock, kern);
 333 }
 334
 335 static const struct proto_ops alg_proto_ops = {
 336         .family         =       PF_ALG,
 337         .owner          =       THIS_MODULE,
 338
 339         .connect        =       sock_no_connect,
 340         .socketpair     =       sock_no_socketpair,
 341         .getname        =       sock_no_getname,
 342         .ioctl          =       sock_no_ioctl,
 343         .listen         =       sock_no_listen,
 344         .shutdown       =       sock_no_shutdown,
 345         .getsockopt     =       sock_no_getsockopt,
 346         .mmap           =       sock_no_mmap,
 347         .sendpage       =       sock_no_sendpage,
 348         .sendmsg        =       sock_no_sendmsg,
 349         .recvmsg        =       sock_no_recvmsg,
 350         .poll           =       sock_no_poll,
 351
 352         .bind           =       alg_bind,
 353         .release        =       af_alg_release,
 354         .setsockopt     =       alg_setsockopt,
 355         .accept         =       alg_accept,
 356 };
 357
 358 static void alg_sock_destruct(struct sock *sk)
 359 {
 360         struct alg_sock *ask = alg_sk(sk);
 361
 362         alg_do_release(ask->type, ask->private);
 363 }
 364
 365 static int alg_create(struct net *net, struct socket *sock, int protocol,
 366                       int kern)
 367 {
 368         struct sock *sk;
 369         int err;
 370
 371         if (sock->type != SOCK_SEQPACKET)
 372                 return -ESOCKTNOSUPPORT;
 373         if (protocol != 0)
 374                 return -EPROTONOSUPPORT;
 375
 376         err = -ENOMEM;
 377         sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
 378         if (!sk)
 379                 goto out;
 380
 381         sock->ops = &alg_proto_ops;
 382         sock_init_data(sock, sk);
 383
 384         sk->sk_family = PF_ALG;
 385         sk->sk_destruct = alg_sock_destruct;
 386
 387         return 0;
 388 out:
 389         return err;
 390 }
 391
 392 static const struct net_proto_family alg_family = {
 393         .family =       PF_ALG,
 394         .create =       alg_create,
 395         .owner  =       THIS_MODULE,
 396 };
 397
 398 int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
 399 {
 400         size_t off;
 401         ssize_t n;
 402         int npages, i;
 403
 404         n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
 405         if (n < 0)
 406                 return n;
 407
 408         npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT;
 409         if (WARN_ON(npages == 0))
 410                 return -EINVAL;
 411         /* Add one extra for linking */
 412         sg_init_table(sgl->sg, npages + 1);
 413
 414         for (i = 0, len = n; i < npages; i++) {
 415                 int plen = min_t(int, len, PAGE_SIZE - off);
 416
 417                 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
 418
 419                 off = 0;
 420                 len -= plen;
 421         }
 422         sg_mark_end(sgl->sg + npages - 1);
 423         sgl->npages = npages;
 424
 425         return n;
 426 }
 427 EXPORT_SYMBOL_GPL(af_alg_make_sg);
 428
 429 void af_alg_link_sg(struct af_alg_sgl *sgl_prev, struct af_alg_sgl *sgl_new)
 430 {
 431         sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
 432         sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
 433 }
 434 EXPORT_SYMBOL_GPL(af_alg_link_sg);
 435
 436 void af_alg_free_sg(struct af_alg_sgl *sgl)
 437 {
 438         int i;
 439
 440         for (i = 0; i < sgl->npages; i++)
 441                 put_page(sgl->pages[i]);
 442 }
 443 EXPORT_SYMBOL_GPL(af_alg_free_sg);
 444
 445 int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
 446 {
 447         struct cmsghdr *cmsg;
 448
 449         for_each_cmsghdr(cmsg, msg) {
 450                 if (!CMSG_OK(msg, cmsg))
 451                         return -EINVAL;
 452                 if (cmsg->cmsg_level != SOL_ALG)
 453                         continue;
 454
 455                 switch (cmsg->cmsg_type) {
 456                 case ALG_SET_IV:
 457                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
 458                                 return -EINVAL;
 459                         con->iv = (void *)CMSG_DATA(cmsg);
 460                         if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
 461                                                       sizeof(*con->iv)))
 462                                 return -EINVAL;
 463                         break;
 464
 465                 case ALG_SET_OP:
 466                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
 467                                 return -EINVAL;
 468                         con->op = *(u32 *)CMSG_DATA(cmsg);
 469                         break;
 470
 471                 case ALG_SET_AEAD_ASSOCLEN:
 472                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
 473                                 return -EINVAL;
 474                         con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
 475                         break;
 476
 477                 default:
 478                         return -EINVAL;
 479                 }
 480         }
 481
 482         return 0;
 483 }
 484 EXPORT_SYMBOL_GPL(af_alg_cmsg_send);
 485
 486 /**
 487  * af_alg_alloc_tsgl - allocate the TX SGL
 488  *
 489  * @sk socket of connection to user space
 490  * @return: 0 upon success, < 0 upon error
 491  */
 492 int af_alg_alloc_tsgl(struct sock *sk)
 493 {
 494         struct alg_sock *ask = alg_sk(sk);
 495         struct af_alg_ctx *ctx = ask->private;
 496         struct af_alg_tsgl *sgl;
 497         struct scatterlist *sg = NULL;
 498
 499         sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
 500         if (!list_empty(&ctx->tsgl_list))
 501                 sg = sgl->sg;
 502
 503         if (!sg || sgl->cur >= MAX_SGL_ENTS) {
 504                 sgl = sock_kmalloc(sk, sizeof(*sgl) +
 505                                        sizeof(sgl->sg[0]) * (MAX_SGL_ENTS + 1),
 506                                    GFP_KERNEL);
 507                 if (!sgl)
 508                         return -ENOMEM;
 509
 510                 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
 511                 sgl->cur = 0;
 512
 513                 if (sg)
 514                         sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
 515
 516                 list_add_tail(&sgl->list, &ctx->tsgl_list);
 517         }
 518
 519         return 0;
 520 }
 521 EXPORT_SYMBOL_GPL(af_alg_alloc_tsgl);
 522
 523 /**
 524  * aead_count_tsgl - Count number of TX SG entries
 525  *
 526  * The counting starts from the beginning of the SGL to @bytes. If
 527  * an offset is provided, the counting of the SG entries starts at the offset.
 528  *
 529  * @sk socket of connection to user space
 530  * @bytes Count the number of SG entries holding given number of bytes.
 531  * @offset Start the counting of SG entries from the given offset.
 532  * @return Number of TX SG entries found given the constraints
 533  */
 534 unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
 535 {
 536         struct alg_sock *ask = alg_sk(sk);
 537         struct af_alg_ctx *ctx = ask->private;
 538         struct af_alg_tsgl *sgl, *tmp;
 539         unsigned int i;
 540         unsigned int sgl_count = 0;
 541
 542         if (!bytes)
 543                 return 0;
 544
 545         list_for_each_entry_safe(sgl, tmp, &ctx->tsgl_list, list) {
 546                 struct scatterlist *sg = sgl->sg;
 547
 548                 for (i = 0; i < sgl->cur; i++) {
 549                         size_t bytes_count;
 550
 551                         /* Skip offset */
 552                         if (offset >= sg[i].length) {
 553                                 offset -= sg[i].length;
 554                                 bytes -= sg[i].length;
 555                                 continue;
 556                         }
 557
 558                         bytes_count = sg[i].length - offset;
 559
 560                         offset = 0;
 561                         sgl_count++;
 562
 563                         /* If we have seen requested number of bytes, stop */
 564                         if (bytes_count >= bytes)
 565                                 return sgl_count;
 566
 567                         bytes -= bytes_count;
 568                 }
 569         }
 570
 571         return sgl_count;
 572 }
 573 EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
 574
 575 /**
 576  * aead_pull_tsgl - Release the specified buffers from TX SGL
 577  *
 578  * If @dst is non-null, reassign the pages to dst. The caller must release
 579  * the pages. If @dst_offset is given only reassign the pages to @dst starting
 580  * at the @dst_offset (byte). The caller must ensure that @dst is large
 581  * enough (e.g. by using af_alg_count_tsgl with the same offset).
 582  *
 583  * @sk socket of connection to user space
 584  * @used Number of bytes to pull from TX SGL
 585  * @dst If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
 586  *      caller must release the buffers in dst.
 587  * @dst_offset Reassign the TX SGL from given offset. All buffers before
 588  *             reaching the offset is released.
 589  */
 590 void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
 591                       size_t dst_offset)
 592 {
 593         struct alg_sock *ask = alg_sk(sk);
 594         struct af_alg_ctx *ctx = ask->private;
 595         struct af_alg_tsgl *sgl;
 596         struct scatterlist *sg;
 597         unsigned int i, j = 0;
 598
 599         while (!list_empty(&ctx->tsgl_list)) {
 600                 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
 601                                        list);
 602                 sg = sgl->sg;
 603
 604                 for (i = 0; i < sgl->cur; i++) {
 605                         size_t plen = min_t(size_t, used, sg[i].length);
 606                         struct page *page = sg_page(sg + i);
 607
 608                         if (!page)
 609                                 continue;
 610
 611                         /*
 612                          * Assumption: caller created af_alg_count_tsgl(len)
 613                          * SG entries in dst.
 614                          */
 615                         if (dst) {
 616                                 if (dst_offset >= plen) {
 617                                         /* discard page before offset */
 618                                         dst_offset -= plen;
 619                                 } else {
 620                                         /* reassign page to dst after offset */
 621                                         get_page(page);
 622                                         sg_set_page(dst + j, page,
 623                                                     plen - dst_offset,
 624                                                     sg[i].offset + dst_offset);
 625                                         dst_offset = 0;
 626                                         j++;
 627                                 }
 628                         }
 629
 630                         sg[i].length -= plen;
 631                         sg[i].offset += plen;
 632
 633                         used -= plen;
 634                         ctx->used -= plen;
 635
 636                         if (sg[i].length)
 637                                 return;
 638
 639                         put_page(page);
 640                         sg_assign_page(sg + i, NULL);
 641                 }
 642
 643                 list_del(&sgl->list);
 644                 sock_kfree_s(sk, sgl, sizeof(*sgl) + sizeof(sgl->sg[0]) *
 645                                                      (MAX_SGL_ENTS + 1));
 646         }
 647
 648         if (!ctx->used)
 649                 ctx->merge = 0;
 650 }
 651 EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
 652
 653 /**
 654  * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
 655  *
 656  * @areq Request holding the TX and RX SGL
 657  */
 658 void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
 659 {
 660         struct sock *sk = areq->sk;
 661         struct alg_sock *ask = alg_sk(sk);
 662         struct af_alg_ctx *ctx = ask->private;
 663         struct af_alg_rsgl *rsgl, *tmp;
 664         struct scatterlist *tsgl;
 665         struct scatterlist *sg;
 666         unsigned int i;
 667
 668         list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
 669                 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
 670                 af_alg_free_sg(&rsgl->sgl);
 671                 list_del(&rsgl->list);
 672                 if (rsgl != &areq->first_rsgl)
 673                         sock_kfree_s(sk, rsgl, sizeof(*rsgl));
 674         }
 675
 676         tsgl = areq->tsgl;
 677         if (tsgl) {
 678                 for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
 679                         if (!sg_page(sg))
 680                                 continue;
 681                         put_page(sg_page(sg));
 682                 }
 683
 684                 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
 685         }
 686 }
 687 EXPORT_SYMBOL_GPL(af_alg_free_areq_sgls);
 688
 689 /**
 690  * af_alg_wait_for_wmem - wait for availability of writable memory
 691  *
 692  * @sk socket of connection to user space
 693  * @flags If MSG_DONTWAIT is set, then only report if function would sleep
 694  * @return 0 when writable memory is available, < 0 upon error
 695  */
 696 int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
 697 {
 698         DEFINE_WAIT_FUNC(wait, woken_wake_function);
 699         int err = -ERESTARTSYS;
 700         long timeout;
 701
 702         if (flags & MSG_DONTWAIT)
 703                 return -EAGAIN;
 704
 705         sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 706
 707         add_wait_queue(sk_sleep(sk), &wait);
 708         for (;;) {
 709                 if (signal_pending(current))
 710                         break;
 711                 timeout = MAX_SCHEDULE_TIMEOUT;
 712                 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
 713                         err = 0;
 714                         break;
 715                 }
 716         }
 717         remove_wait_queue(sk_sleep(sk), &wait);
 718
 719         return err;
 720 }
 721 EXPORT_SYMBOL_GPL(af_alg_wait_for_wmem);
 722
 723 /**
 724  * af_alg_wmem_wakeup - wakeup caller when writable memory is available
 725  *
 726  * @sk socket of connection to user space
 727  */
 728 void af_alg_wmem_wakeup(struct sock *sk)
 729 {
 730         struct socket_wq *wq;
 731
 732         if (!af_alg_writable(sk))
 733                 return;
 734
 735         rcu_read_lock();
 736         wq = rcu_dereference(sk->sk_wq);
 737         if (skwq_has_sleeper(wq))
 738                 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN |
 739                                                            EPOLLRDNORM |
 740                                                            EPOLLRDBAND);
 741         sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
 742         rcu_read_unlock();
 743 }
 744 EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
 745
 746 /**
 747  * af_alg_wait_for_data - wait for availability of TX data
 748  *
 749  * @sk socket of connection to user space
 750  * @flags If MSG_DONTWAIT is set, then only report if function would sleep
 751  * @return 0 when writable memory is available, < 0 upon error
 752  */
 753 int af_alg_wait_for_data(struct sock *sk, unsigned flags)
 754 {
 755         DEFINE_WAIT_FUNC(wait, woken_wake_function);
 756         struct alg_sock *ask = alg_sk(sk);
 757         struct af_alg_ctx *ctx = ask->private;
 758         long timeout;
 759         int err = -ERESTARTSYS;
 760
 761         if (flags & MSG_DONTWAIT)
 762                 return -EAGAIN;
 763
 764         sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
 765
 766         add_wait_queue(sk_sleep(sk), &wait);
 767         for (;;) {
 768                 if (signal_pending(current))
 769                         break;
 770                 timeout = MAX_SCHEDULE_TIMEOUT;
 771                 if (sk_wait_event(sk, &timeout, (ctx->used || !ctx->more),
 772                                   &wait)) {
 773                         err = 0;
 774                         break;
 775                 }
 776         }
 777         remove_wait_queue(sk_sleep(sk), &wait);
 778
 779         sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
 780
 781         return err;
 782 }
 783 EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
 784
 785 /**
 786  * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
 787  *
 788  * @sk socket of connection to user space
 789  */
 790
 791 void af_alg_data_wakeup(struct sock *sk)
 792 {
 793         struct alg_sock *ask = alg_sk(sk);
 794         struct af_alg_ctx *ctx = ask->private;
 795         struct socket_wq *wq;
 796
 797         if (!ctx->used)
 798                 return;
 799
 800         rcu_read_lock();
 801         wq = rcu_dereference(sk->sk_wq);
 802         if (skwq_has_sleeper(wq))
 803                 wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
 804                                                            EPOLLRDNORM |
 805                                                            EPOLLRDBAND);
 806         sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
 807         rcu_read_unlock();
 808 }
 809 EXPORT_SYMBOL_GPL(af_alg_data_wakeup);
 810
 811 /**
 812  * af_alg_sendmsg - implementation of sendmsg system call handler
 813  *
 814  * The sendmsg system call handler obtains the user data and stores it
 815  * in ctx->tsgl_list. This implies allocation of the required numbers of
 816  * struct af_alg_tsgl.
 817  *
 818  * In addition, the ctx is filled with the information sent via CMSG.
 819  *
 820  * @sock socket of connection to user space
 821  * @msg message from user space
 822  * @size size of message from user space
 823  * @ivsize the size of the IV for the cipher operation to verify that the
 824  *         user-space-provided IV has the right size
 825  * @return the number of copied data upon success, < 0 upon error
 826  */
 827 int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
 828                    unsigned int ivsize)
 829 {
 830         struct sock *sk = sock->sk;
 831         struct alg_sock *ask = alg_sk(sk);
 832         struct af_alg_ctx *ctx = ask->private;
 833         struct af_alg_tsgl *sgl;
 834         struct af_alg_control con = {};
 835         long copied = 0;
 836         bool enc = 0;
 837         bool init = 0;
 838         int err = 0;
 839
 840         if (msg->msg_controllen) {
 841                 err = af_alg_cmsg_send(msg, &con);
 842                 if (err)
 843                         return err;
 844
 845                 init = 1;
 846                 switch (con.op) {
 847                 case ALG_OP_ENCRYPT:
 848                         enc = 1;
 849                         break;
 850                 case ALG_OP_DECRYPT:
 851                         enc = 0;
 852                         break;
 853                 default:
 854                         return -EINVAL;
 855                 }
 856
 857                 if (con.iv && con.iv->ivlen != ivsize)
 858                         return -EINVAL;
 859         }
 860
 861         lock_sock(sk);
 862         if (!ctx->more && ctx->used) {
 863                 err = -EINVAL;
 864                 goto unlock;
 865         }
 866
 867         if (init) {
 868                 ctx->enc = enc;
 869                 if (con.iv)
 870                         memcpy(ctx->iv, con.iv->iv, ivsize);
 871
 872                 ctx->aead_assoclen = con.aead_assoclen;
 873         }
 874
 875         while (size) {
 876                 struct scatterlist *sg;
 877                 size_t len = size;
 878                 size_t plen;
 879
 880                 /* use the existing memory in an allocated page */
 881                 if (ctx->merge) {
 882                         sgl = list_entry(ctx->tsgl_list.prev,
 883                                          struct af_alg_tsgl, list);
 884                         sg = sgl->sg + sgl->cur - 1;
 885                         len = min_t(size_t, len,
 886                                     PAGE_SIZE - sg->offset - sg->length);
 887
 888                         err = memcpy_from_msg(page_address(sg_page(sg)) +
 889                                               sg->offset + sg->length,
 890                                               msg, len);
 891                         if (err)
 892                                 goto unlock;
 893
 894                         sg->length += len;
 895                         ctx->merge = (sg->offset + sg->length) &
 896                                      (PAGE_SIZE - 1);
 897
 898                         ctx->used += len;
 899                         copied += len;
 900                         size -= len;
 901                         continue;
 902                 }
 903
 904                 if (!af_alg_writable(sk)) {
 905                         err = af_alg_wait_for_wmem(sk, msg->msg_flags);
 906                         if (err)
 907                                 goto unlock;
 908                 }
 909
 910                 /* allocate a new page */
 911                 len = min_t(unsigned long, len, af_alg_sndbuf(sk));
 912
 913                 err = af_alg_alloc_tsgl(sk);
 914                 if (err)
 915                         goto unlock;
 916
 917                 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
 918                                  list);
 919                 sg = sgl->sg;
 920                 if (sgl->cur)
 921                         sg_unmark_end(sg + sgl->cur - 1);
 922
 923                 do {
 924                         unsigned int i = sgl->cur;
 925
 926                         plen = min_t(size_t, len, PAGE_SIZE);
 927
 928                         sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
 929                         if (!sg_page(sg + i)) {
 930                                 err = -ENOMEM;
 931                                 goto unlock;
 932                         }
 933
 934                         err = memcpy_from_msg(page_address(sg_page(sg + i)),
 935                                               msg, plen);
 936                         if (err) {
 937                                 __free_page(sg_page(sg + i));
 938                                 sg_assign_page(sg + i, NULL);
 939                                 goto unlock;
 940                         }
 941
 942                         sg[i].length = plen;
 943                         len -= plen;
 944                         ctx->used += plen;
 945                         copied += plen;
 946                         size -= plen;
 947                         sgl->cur++;
 948                 } while (len && sgl->cur < MAX_SGL_ENTS);
 949
 950                 if (!size)
 951                         sg_mark_end(sg + sgl->cur - 1);
 952
 953                 ctx->merge = plen & (PAGE_SIZE - 1);
 954         }
 955
 956         err = 0;
 957
 958         ctx->more = msg->msg_flags & MSG_MORE;
 959
 960 unlock:
 961         af_alg_data_wakeup(sk);
 962         release_sock(sk);
 963
 964         return copied ?: err;
 965 }
 966 EXPORT_SYMBOL_GPL(af_alg_sendmsg);
 967
 968 /**
 969  * af_alg_sendpage - sendpage system call handler
 970  *
 971  * This is a generic implementation of sendpage to fill ctx->tsgl_list.
 972  */
 973 ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
 974                         int offset, size_t size, int flags)
 975 {
 976         struct sock *sk = sock->sk;
 977         struct alg_sock *ask = alg_sk(sk);
 978         struct af_alg_ctx *ctx = ask->private;
 979         struct af_alg_tsgl *sgl;
 980         int err = -EINVAL;
 981
 982         if (flags & MSG_SENDPAGE_NOTLAST)
 983                 flags |= MSG_MORE;
 984
 985         lock_sock(sk);
 986         if (!ctx->more && ctx->used)
 987                 goto unlock;
 988
 989         if (!size)
 990                 goto done;
 991
 992         if (!af_alg_writable(sk)) {
 993                 err = af_alg_wait_for_wmem(sk, flags);
 994                 if (err)
 995                         goto unlock;
 996         }
 997
 998         err = af_alg_alloc_tsgl(sk);
 999         if (err)
1000                 goto unlock;
1001
1002         ctx->merge = 0;
1003         sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
1004
1005         if (sgl->cur)
1006                 sg_unmark_end(sgl->sg + sgl->cur - 1);
1007
1008         sg_mark_end(sgl->sg + sgl->cur);
1009
1010         get_page(page);
1011         sg_set_page(sgl->sg + sgl->cur, page, size, offset);
1012         sgl->cur++;
1013         ctx->used += size;
1014
1015 done:
1016         ctx->more = flags & MSG_MORE;
1017
1018 unlock:
1019         af_alg_data_wakeup(sk);
1020         release_sock(sk);
1021
1022         return err ?: size;
1023 }
1024 EXPORT_SYMBOL_GPL(af_alg_sendpage);
1025
1026 /**
1027  * af_alg_free_resources - release resources required for crypto request
1028  */
1029 void af_alg_free_resources(struct af_alg_async_req *areq)
1030 {
1031         struct sock *sk = areq->sk;
1032
1033         af_alg_free_areq_sgls(areq);
1034         sock_kfree_s(sk, areq, areq->areqlen);
1035 }
1036 EXPORT_SYMBOL_GPL(af_alg_free_resources);
1037
1038 /**
1039  * af_alg_async_cb - AIO callback handler
1040  *
1041  * This handler cleans up the struct af_alg_async_req upon completion of the
1042  * AIO operation.
1043  *
1044  * The number of bytes to be generated with the AIO operation must be set
1045  * in areq->outlen before the AIO callback handler is invoked.
1046  */
1047 void af_alg_async_cb(struct crypto_async_request *_req, int err)
1048 {
1049         struct af_alg_async_req *areq = _req->data;
1050         struct sock *sk = areq->sk;
1051         struct kiocb *iocb = areq->iocb;
1052         unsigned int resultlen;
1053
1054         /* Buffer size written by crypto operation. */
1055         resultlen = areq->outlen;
1056
1057         af_alg_free_resources(areq);
1058         sock_put(sk);
1059
1060         iocb->ki_complete(iocb, err ? err : resultlen, 0);
1061 }
1062 EXPORT_SYMBOL_GPL(af_alg_async_cb);
1063
1064 /**
1065  * af_alg_poll - poll system call handler
1066  */
1067 __poll_t af_alg_poll(struct file *file, struct socket *sock,
1068                          poll_table *wait)
1069 {
1070         struct sock *sk = sock->sk;
1071         struct alg_sock *ask = alg_sk(sk);
1072         struct af_alg_ctx *ctx = ask->private;
1073         __poll_t mask;
1074
1075         sock_poll_wait(file, sk_sleep(sk), wait);
1076         mask = 0;
1077
1078         if (!ctx->more || ctx->used)
1079                 mask |= EPOLLIN | EPOLLRDNORM;
1080
1081         if (af_alg_writable(sk))
1082                 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1083
1084         return mask;
1085 }
1086 EXPORT_SYMBOL_GPL(af_alg_poll);
1087
1088 /**
1089  * af_alg_alloc_areq - allocate struct af_alg_async_req
1090  *
1091  * @sk socket of connection to user space
1092  * @areqlen size of struct af_alg_async_req + crypto_*_reqsize
1093  * @return allocated data structure or ERR_PTR upon error
1094  */
1095 struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
1096                                            unsigned int areqlen)
1097 {
1098         struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
1099
1100         if (unlikely(!areq))
1101                 return ERR_PTR(-ENOMEM);
1102
1103         areq->areqlen = areqlen;
1104         areq->sk = sk;
1105         areq->last_rsgl = NULL;
1106         INIT_LIST_HEAD(&areq->rsgl_list);
1107         areq->tsgl = NULL;
1108         areq->tsgl_entries = 0;
1109
1110         return areq;
1111 }
1112 EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
1113
1114 /**
1115  * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1116  *                   operation
1117  *
1118  * @sk socket of connection to user space
1119  * @msg user space message
1120  * @flags flags used to invoke recvmsg with
1121  * @areq instance of the cryptographic request that will hold the RX SGL
1122  * @maxsize maximum number of bytes to be pulled from user space
1123  * @outlen number of bytes in the RX SGL
1124  * @return 0 on success, < 0 upon error
1125  */
1126 int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
1127                     struct af_alg_async_req *areq, size_t maxsize,
1128                     size_t *outlen)
1129 {
1130         struct alg_sock *ask = alg_sk(sk);
1131         struct af_alg_ctx *ctx = ask->private;
1132         size_t len = 0;
1133
1134         while (maxsize > len && msg_data_left(msg)) {
1135                 struct af_alg_rsgl *rsgl;
1136                 size_t seglen;
1137                 int err;
1138
1139                 /* limit the amount of readable buffers */
1140                 if (!af_alg_readable(sk))
1141                         break;
1142
1143                 seglen = min_t(size_t, (maxsize - len),
1144                                msg_data_left(msg));
1145
1146                 if (list_empty(&areq->rsgl_list)) {
1147                         rsgl = &areq->first_rsgl;
1148                 } else {
1149                         rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
1150                         if (unlikely(!rsgl))
1151                                 return -ENOMEM;
1152                 }
1153
1154                 rsgl->sgl.npages = 0;
1155                 list_add_tail(&rsgl->list, &areq->rsgl_list);
1156
1157                 /* make one iovec available as scatterlist */
1158                 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
1159                 if (err < 0)
1160                         return err;
1161
1162                 /* chain the new scatterlist with previous one */
1163                 if (areq->last_rsgl)
1164                         af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
1165
1166                 areq->last_rsgl = rsgl;
1167                 len += err;
1168                 atomic_add(err, &ctx->rcvused);
1169                 rsgl->sg_num_bytes = err;
1170                 iov_iter_advance(&msg->msg_iter, err);
1171         }
1172
1173         *outlen = len;
1174         return 0;
1175 }
1176 EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
1177
1178 static int __init af_alg_init(void)
1179 {
1180         int err = proto_register(&alg_proto, 0);
1181
1182         if (err)
1183                 goto out;
1184
1185         err = sock_register(&alg_family);
1186         if (err != 0)
1187                 goto out_unregister_proto;
1188
1189 out:
1190         return err;
1191
1192 out_unregister_proto:
1193         proto_unregister(&alg_proto);
1194         goto out;
1195 }
1196
1197 static void __exit af_alg_exit(void)
1198 {
1199         sock_unregister(PF_ALG);
1200         proto_unregister(&alg_proto);
1201 }
1202
1203 module_init(af_alg_init);
1204 module_exit(af_alg_exit);
1205 MODULE_LICENSE("GPL");
1206 MODULE_ALIAS_NETPROTO(AF_ALG);