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                 sock->sk = NULL;
 128         }
 129         return 0;
 130 }
 131 EXPORT_SYMBOL_GPL(af_alg_release);
 132
 133 void af_alg_release_parent(struct sock *sk)
 134 {
 135         struct alg_sock *ask = alg_sk(sk);
 136         unsigned int nokey = ask->nokey_refcnt;
 137         bool last = nokey && !ask->refcnt;
 138
 139         sk = ask->parent;
 140         ask = alg_sk(sk);
 141
 142         lock_sock(sk);
 143         ask->nokey_refcnt -= nokey;
 144         if (!last)
 145                 last = !--ask->refcnt;
 146         release_sock(sk);
 147
 148         if (last)
 149                 sock_put(sk);
 150 }
 151 EXPORT_SYMBOL_GPL(af_alg_release_parent);
 152
 153 static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 154 {
 155         const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY;
 156         struct sock *sk = sock->sk;
 157         struct alg_sock *ask = alg_sk(sk);
 158         struct sockaddr_alg *sa = (void *)uaddr;
 159         const struct af_alg_type *type;
 160         void *private;
 161         int err;
 162
 163         if (sock->state == SS_CONNECTED)
 164                 return -EINVAL;
 165
 166         if (addr_len < sizeof(*sa))
 167                 return -EINVAL;
 168
 169         /* If caller uses non-allowed flag, return error. */
 170         if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed))
 171                 return -EINVAL;
 172
 173         sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
 174         sa->salg_name[sizeof(sa->salg_name) + addr_len - sizeof(*sa) - 1] = 0;
 175
 176         type = alg_get_type(sa->salg_type);
 177         if (IS_ERR(type) && PTR_ERR(type) == -ENOENT) {
 178                 request_module("algif-%s", sa->salg_type);
 179                 type = alg_get_type(sa->salg_type);
 180         }
 181
 182         if (IS_ERR(type))
 183                 return PTR_ERR(type);
 184
 185         private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask);
 186         if (IS_ERR(private)) {
 187                 module_put(type->owner);
 188                 return PTR_ERR(private);
 189         }
 190
 191         err = -EBUSY;
 192         lock_sock(sk);
 193         if (ask->refcnt | ask->nokey_refcnt)
 194                 goto unlock;
 195
 196         swap(ask->type, type);
 197         swap(ask->private, private);
 198
 199         err = 0;
 200
 201 unlock:
 202         release_sock(sk);
 203
 204         alg_do_release(type, private);
 205
 206         return err;
 207 }
 208
 209 static int alg_setkey(struct sock *sk, char __user *ukey,
 210                       unsigned int keylen)
 211 {
 212         struct alg_sock *ask = alg_sk(sk);
 213         const struct af_alg_type *type = ask->type;
 214         u8 *key;
 215         int err;
 216
 217         key = sock_kmalloc(sk, keylen, GFP_KERNEL);
 218         if (!key)
 219                 return -ENOMEM;
 220
 221         err = -EFAULT;
 222         if (copy_from_user(key, ukey, keylen))
 223                 goto out;
 224
 225         err = type->setkey(ask->private, key, keylen);
 226
 227 out:
 228         sock_kzfree_s(sk, key, keylen);
 229
 230         return err;
 231 }
 232
 233 static int alg_setsockopt(struct socket *sock, int level, int optname,
 234                           char __user *optval, unsigned int optlen)
 235 {
 236         struct sock *sk = sock->sk;
 237         struct alg_sock *ask = alg_sk(sk);
 238         const struct af_alg_type *type;
 239         int err = -EBUSY;
 240
 241         lock_sock(sk);
 242         if (ask->refcnt)
 243                 goto unlock;
 244
 245         type = ask->type;
 246
 247         err = -ENOPROTOOPT;
 248         if (level != SOL_ALG || !type)
 249                 goto unlock;
 250
 251         switch (optname) {
 252         case ALG_SET_KEY:
 253                 if (sock->state == SS_CONNECTED)
 254                         goto unlock;
 255                 if (!type->setkey)
 256                         goto unlock;
 257
 258                 err = alg_setkey(sk, optval, optlen);
 259                 break;
 260         case ALG_SET_AEAD_AUTHSIZE:
 261                 if (sock->state == SS_CONNECTED)
 262                         goto unlock;
 263                 if (!type->setauthsize)
 264                         goto unlock;
 265                 err = type->setauthsize(ask->private, optlen);
 266         }
 267
 268 unlock:
 269         release_sock(sk);
 270
 271         return err;
 272 }
 273
 274 int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern)
 275 {
 276         struct alg_sock *ask = alg_sk(sk);
 277         const struct af_alg_type *type;
 278         struct sock *sk2;
 279         unsigned int nokey;
 280         int err;
 281
 282         lock_sock(sk);
 283         type = ask->type;
 284
 285         err = -EINVAL;
 286         if (!type)
 287                 goto unlock;
 288
 289         sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, kern);
 290         err = -ENOMEM;
 291         if (!sk2)
 292                 goto unlock;
 293
 294         sock_init_data(newsock, sk2);
 295         security_sock_graft(sk2, newsock);
 296         security_sk_clone(sk, sk2);
 297
 298         err = type->accept(ask->private, sk2);
 299
 300         nokey = err == -ENOKEY;
 301         if (nokey && type->accept_nokey)
 302                 err = type->accept_nokey(ask->private, sk2);
 303
 304         if (err)
 305                 goto unlock;
 306
 307         sk2->sk_family = PF_ALG;
 308
 309         if (nokey || !ask->refcnt++)
 310                 sock_hold(sk);
 311         ask->nokey_refcnt += nokey;
 312         alg_sk(sk2)->parent = sk;
 313         alg_sk(sk2)->type = type;
 314         alg_sk(sk2)->nokey_refcnt = nokey;
 315
 316         newsock->ops = type->ops;
 317         newsock->state = SS_CONNECTED;
 318
 319         if (nokey)
 320                 newsock->ops = type->ops_nokey;
 321
 322         err = 0;
 323
 324 unlock:
 325         release_sock(sk);
 326
 327         return err;
 328 }
 329 EXPORT_SYMBOL_GPL(af_alg_accept);
 330
 331 static int alg_accept(struct socket *sock, struct socket *newsock, int flags,
 332                       bool kern)
 333 {
 334         return af_alg_accept(sock->sk, newsock, kern);
 335 }
 336
 337 static const struct proto_ops alg_proto_ops = {
 338         .family         =       PF_ALG,
 339         .owner          =       THIS_MODULE,
 340
 341         .connect        =       sock_no_connect,
 342         .socketpair     =       sock_no_socketpair,
 343         .getname        =       sock_no_getname,
 344         .ioctl          =       sock_no_ioctl,
 345         .listen         =       sock_no_listen,
 346         .shutdown       =       sock_no_shutdown,
 347         .getsockopt     =       sock_no_getsockopt,
 348         .mmap           =       sock_no_mmap,
 349         .sendpage       =       sock_no_sendpage,
 350         .sendmsg        =       sock_no_sendmsg,
 351         .recvmsg        =       sock_no_recvmsg,
 352         .poll           =       sock_no_poll,
 353
 354         .bind           =       alg_bind,
 355         .release        =       af_alg_release,
 356         .setsockopt     =       alg_setsockopt,
 357         .accept         =       alg_accept,
 358 };
 359
 360 static void alg_sock_destruct(struct sock *sk)
 361 {
 362         struct alg_sock *ask = alg_sk(sk);
 363
 364         alg_do_release(ask->type, ask->private);
 365 }
 366
 367 static int alg_create(struct net *net, struct socket *sock, int protocol,
 368                       int kern)
 369 {
 370         struct sock *sk;
 371         int err;
 372
 373         if (sock->type != SOCK_SEQPACKET)
 374                 return -ESOCKTNOSUPPORT;
 375         if (protocol != 0)
 376                 return -EPROTONOSUPPORT;
 377
 378         err = -ENOMEM;
 379         sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
 380         if (!sk)
 381                 goto out;
 382
 383         sock->ops = &alg_proto_ops;
 384         sock_init_data(sock, sk);
 385
 386         sk->sk_family = PF_ALG;
 387         sk->sk_destruct = alg_sock_destruct;
 388
 389         return 0;
 390 out:
 391         return err;
 392 }
 393
 394 static const struct net_proto_family alg_family = {
 395         .family =       PF_ALG,
 396         .create =       alg_create,
 397         .owner  =       THIS_MODULE,
 398 };
 399
 400 int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
 401 {
 402         size_t off;
 403         ssize_t n;
 404         int npages, i;
 405
 406         n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
 407         if (n < 0)
 408                 return n;
 409
 410         npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT;
 411         if (WARN_ON(npages == 0))
 412                 return -EINVAL;
 413         /* Add one extra for linking */
 414         sg_init_table(sgl->sg, npages + 1);
 415
 416         for (i = 0, len = n; i < npages; i++) {
 417                 int plen = min_t(int, len, PAGE_SIZE - off);
 418
 419                 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
 420
 421                 off = 0;
 422                 len -= plen;
 423         }
 424         sg_mark_end(sgl->sg + npages - 1);
 425         sgl->npages = npages;
 426
 427         return n;
 428 }
 429 EXPORT_SYMBOL_GPL(af_alg_make_sg);
 430
 431 void af_alg_link_sg(struct af_alg_sgl *sgl_prev, struct af_alg_sgl *sgl_new)
 432 {
 433         sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
 434         sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
 435 }
 436 EXPORT_SYMBOL_GPL(af_alg_link_sg);
 437
 438 void af_alg_free_sg(struct af_alg_sgl *sgl)
 439 {
 440         int i;
 441
 442         for (i = 0; i < sgl->npages; i++)
 443                 put_page(sgl->pages[i]);
 444 }
 445 EXPORT_SYMBOL_GPL(af_alg_free_sg);
 446
 447 int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
 448 {
 449         struct cmsghdr *cmsg;
 450
 451         for_each_cmsghdr(cmsg, msg) {
 452                 if (!CMSG_OK(msg, cmsg))
 453                         return -EINVAL;
 454                 if (cmsg->cmsg_level != SOL_ALG)
 455                         continue;
 456
 457                 switch (cmsg->cmsg_type) {
 458                 case ALG_SET_IV:
 459                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
 460                                 return -EINVAL;
 461                         con->iv = (void *)CMSG_DATA(cmsg);
 462                         if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
 463                                                       sizeof(*con->iv)))
 464                                 return -EINVAL;
 465                         break;
 466
 467                 case ALG_SET_OP:
 468                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
 469                                 return -EINVAL;
 470                         con->op = *(u32 *)CMSG_DATA(cmsg);
 471                         break;
 472
 473                 case ALG_SET_AEAD_ASSOCLEN:
 474                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
 475                                 return -EINVAL;
 476                         con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
 477                         break;
 478
 479                 default:
 480                         return -EINVAL;
 481                 }
 482         }
 483
 484         return 0;
 485 }
 486 EXPORT_SYMBOL_GPL(af_alg_cmsg_send);
 487
 488 int af_alg_wait_for_completion(int err, struct af_alg_completion *completion)
 489 {
 490         switch (err) {
 491         case -EINPROGRESS:
 492         case -EBUSY:
 493                 wait_for_completion(&completion->completion);
 494                 reinit_completion(&completion->completion);
 495                 err = completion->err;
 496                 break;
 497         };
 498
 499         return err;
 500 }
 501 EXPORT_SYMBOL_GPL(af_alg_wait_for_completion);
 502
 503 void af_alg_complete(struct crypto_async_request *req, int err)
 504 {
 505         struct af_alg_completion *completion = req->data;
 506
 507         if (err == -EINPROGRESS)
 508                 return;
 509
 510         completion->err = err;
 511         complete(&completion->completion);
 512 }
 513 EXPORT_SYMBOL_GPL(af_alg_complete);
 514
 515 /**
 516  * af_alg_alloc_tsgl - allocate the TX SGL
 517  *
 518  * @sk socket of connection to user space
 519  * @return: 0 upon success, < 0 upon error
 520  */
 521 int af_alg_alloc_tsgl(struct sock *sk)
 522 {
 523         struct alg_sock *ask = alg_sk(sk);
 524         struct af_alg_ctx *ctx = ask->private;
 525         struct af_alg_tsgl *sgl;
 526         struct scatterlist *sg = NULL;
 527
 528         sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
 529         if (!list_empty(&ctx->tsgl_list))
 530                 sg = sgl->sg;
 531
 532         if (!sg || sgl->cur >= MAX_SGL_ENTS) {
 533                 sgl = sock_kmalloc(sk, sizeof(*sgl) +
 534                                        sizeof(sgl->sg[0]) * (MAX_SGL_ENTS + 1),
 535                                    GFP_KERNEL);
 536                 if (!sgl)
 537                         return -ENOMEM;
 538
 539                 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
 540                 sgl->cur = 0;
 541
 542                 if (sg)
 543                         sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
 544
 545                 list_add_tail(&sgl->list, &ctx->tsgl_list);
 546         }
 547
 548         return 0;
 549 }
 550 EXPORT_SYMBOL_GPL(af_alg_alloc_tsgl);
 551
 552 /**
 553  * aead_count_tsgl - Count number of TX SG entries
 554  *
 555  * The counting starts from the beginning of the SGL to @bytes. If
 556  * an offset is provided, the counting of the SG entries starts at the offset.
 557  *
 558  * @sk socket of connection to user space
 559  * @bytes Count the number of SG entries holding given number of bytes.
 560  * @offset Start the counting of SG entries from the given offset.
 561  * @return Number of TX SG entries found given the constraints
 562  */
 563 unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
 564 {
 565         struct alg_sock *ask = alg_sk(sk);
 566         struct af_alg_ctx *ctx = ask->private;
 567         struct af_alg_tsgl *sgl, *tmp;
 568         unsigned int i;
 569         unsigned int sgl_count = 0;
 570
 571         if (!bytes)
 572                 return 0;
 573
 574         list_for_each_entry_safe(sgl, tmp, &ctx->tsgl_list, list) {
 575                 struct scatterlist *sg = sgl->sg;
 576
 577                 for (i = 0; i < sgl->cur; i++) {
 578                         size_t bytes_count;
 579
 580                         /* Skip offset */
 581                         if (offset >= sg[i].length) {
 582                                 offset -= sg[i].length;
 583                                 bytes -= sg[i].length;
 584                                 continue;
 585                         }
 586
 587                         bytes_count = sg[i].length - offset;
 588
 589                         offset = 0;
 590                         sgl_count++;
 591
 592                         /* If we have seen requested number of bytes, stop */
 593                         if (bytes_count >= bytes)
 594                                 return sgl_count;
 595
 596                         bytes -= bytes_count;
 597                 }
 598         }
 599
 600         return sgl_count;
 601 }
 602 EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
 603
 604 /**
 605  * aead_pull_tsgl - Release the specified buffers from TX SGL
 606  *
 607  * If @dst is non-null, reassign the pages to dst. The caller must release
 608  * the pages. If @dst_offset is given only reassign the pages to @dst starting
 609  * at the @dst_offset (byte). The caller must ensure that @dst is large
 610  * enough (e.g. by using af_alg_count_tsgl with the same offset).
 611  *
 612  * @sk socket of connection to user space
 613  * @used Number of bytes to pull from TX SGL
 614  * @dst If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
 615  *      caller must release the buffers in dst.
 616  * @dst_offset Reassign the TX SGL from given offset. All buffers before
 617  *             reaching the offset is released.
 618  */
 619 void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
 620                       size_t dst_offset)
 621 {
 622         struct alg_sock *ask = alg_sk(sk);
 623         struct af_alg_ctx *ctx = ask->private;
 624         struct af_alg_tsgl *sgl;
 625         struct scatterlist *sg;
 626         unsigned int i, j = 0;
 627
 628         while (!list_empty(&ctx->tsgl_list)) {
 629                 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
 630                                        list);
 631                 sg = sgl->sg;
 632
 633                 for (i = 0; i < sgl->cur; i++) {
 634                         size_t plen = min_t(size_t, used, sg[i].length);
 635                         struct page *page = sg_page(sg + i);
 636
 637                         if (!page)
 638                                 continue;
 639
 640                         /*
 641                          * Assumption: caller created af_alg_count_tsgl(len)
 642                          * SG entries in dst.
 643                          */
 644                         if (dst) {
 645                                 if (dst_offset >= plen) {
 646                                         /* discard page before offset */
 647                                         dst_offset -= plen;
 648                                 } else {
 649                                         /* reassign page to dst after offset */
 650                                         get_page(page);
 651                                         sg_set_page(dst + j, page,
 652                                                     plen - dst_offset,
 653                                                     sg[i].offset + dst_offset);
 654                                         dst_offset = 0;
 655                                         j++;
 656                                 }
 657                         }
 658
 659                         sg[i].length -= plen;
 660                         sg[i].offset += plen;
 661
 662                         used -= plen;
 663                         ctx->used -= plen;
 664
 665                         if (sg[i].length)
 666                                 return;
 667
 668                         put_page(page);
 669                         sg_assign_page(sg + i, NULL);
 670                 }
 671
 672                 list_del(&sgl->list);
 673                 sock_kfree_s(sk, sgl, sizeof(*sgl) + sizeof(sgl->sg[0]) *
 674                                                      (MAX_SGL_ENTS + 1));
 675         }
 676
 677         if (!ctx->used)
 678                 ctx->merge = 0;
 679 }
 680 EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
 681
 682 /**
 683  * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
 684  *
 685  * @areq Request holding the TX and RX SGL
 686  */
 687 void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
 688 {
 689         struct sock *sk = areq->sk;
 690         struct alg_sock *ask = alg_sk(sk);
 691         struct af_alg_ctx *ctx = ask->private;
 692         struct af_alg_rsgl *rsgl, *tmp;
 693         struct scatterlist *tsgl;
 694         struct scatterlist *sg;
 695         unsigned int i;
 696
 697         list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
 698                 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
 699                 af_alg_free_sg(&rsgl->sgl);
 700                 list_del(&rsgl->list);
 701                 if (rsgl != &areq->first_rsgl)
 702                         sock_kfree_s(sk, rsgl, sizeof(*rsgl));
 703         }
 704
 705         tsgl = areq->tsgl;
 706         if (tsgl) {
 707                 for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
 708                         if (!sg_page(sg))
 709                                 continue;
 710                         put_page(sg_page(sg));
 711                 }
 712
 713                 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
 714         }
 715 }
 716 EXPORT_SYMBOL_GPL(af_alg_free_areq_sgls);
 717
 718 /**
 719  * af_alg_wait_for_wmem - wait for availability of writable memory
 720  *
 721  * @sk socket of connection to user space
 722  * @flags If MSG_DONTWAIT is set, then only report if function would sleep
 723  * @return 0 when writable memory is available, < 0 upon error
 724  */
 725 int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
 726 {
 727         DEFINE_WAIT_FUNC(wait, woken_wake_function);
 728         int err = -ERESTARTSYS;
 729         long timeout;
 730
 731         if (flags & MSG_DONTWAIT)
 732                 return -EAGAIN;
 733
 734         sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 735
 736         add_wait_queue(sk_sleep(sk), &wait);
 737         for (;;) {
 738                 if (signal_pending(current))
 739                         break;
 740                 timeout = MAX_SCHEDULE_TIMEOUT;
 741                 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
 742                         err = 0;
 743                         break;
 744                 }
 745         }
 746         remove_wait_queue(sk_sleep(sk), &wait);
 747
 748         return err;
 749 }
 750 EXPORT_SYMBOL_GPL(af_alg_wait_for_wmem);
 751
 752 /**
 753  * af_alg_wmem_wakeup - wakeup caller when writable memory is available
 754  *
 755  * @sk socket of connection to user space
 756  */
 757 void af_alg_wmem_wakeup(struct sock *sk)
 758 {
 759         struct socket_wq *wq;
 760
 761         if (!af_alg_writable(sk))
 762                 return;
 763
 764         rcu_read_lock();
 765         wq = rcu_dereference(sk->sk_wq);
 766         if (skwq_has_sleeper(wq))
 767                 wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
 768                                                            POLLRDNORM |
 769                                                            POLLRDBAND);
 770         sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
 771         rcu_read_unlock();
 772 }
 773 EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
 774
 775 /**
 776  * af_alg_wait_for_data - wait for availability of TX data
 777  *
 778  * @sk socket of connection to user space
 779  * @flags If MSG_DONTWAIT is set, then only report if function would sleep
 780  * @return 0 when writable memory is available, < 0 upon error
 781  */
 782 int af_alg_wait_for_data(struct sock *sk, unsigned flags)
 783 {
 784         DEFINE_WAIT_FUNC(wait, woken_wake_function);
 785         struct alg_sock *ask = alg_sk(sk);
 786         struct af_alg_ctx *ctx = ask->private;
 787         long timeout;
 788         int err = -ERESTARTSYS;
 789
 790         if (flags & MSG_DONTWAIT)
 791                 return -EAGAIN;
 792
 793         sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
 794
 795         add_wait_queue(sk_sleep(sk), &wait);
 796         for (;;) {
 797                 if (signal_pending(current))
 798                         break;
 799                 timeout = MAX_SCHEDULE_TIMEOUT;
 800                 if (sk_wait_event(sk, &timeout, (ctx->used || !ctx->more),
 801                                   &wait)) {
 802                         err = 0;
 803                         break;
 804                 }
 805         }
 806         remove_wait_queue(sk_sleep(sk), &wait);
 807
 808         sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
 809
 810         return err;
 811 }
 812 EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
 813
 814 /**
 815  * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
 816  *
 817  * @sk socket of connection to user space
 818  */
 819
 820 void af_alg_data_wakeup(struct sock *sk)
 821 {
 822         struct alg_sock *ask = alg_sk(sk);
 823         struct af_alg_ctx *ctx = ask->private;
 824         struct socket_wq *wq;
 825
 826         if (!ctx->used)
 827                 return;
 828
 829         rcu_read_lock();
 830         wq = rcu_dereference(sk->sk_wq);
 831         if (skwq_has_sleeper(wq))
 832                 wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
 833                                                            POLLRDNORM |
 834                                                            POLLRDBAND);
 835         sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
 836         rcu_read_unlock();
 837 }
 838 EXPORT_SYMBOL_GPL(af_alg_data_wakeup);
 839
 840 /**
 841  * af_alg_sendmsg - implementation of sendmsg system call handler
 842  *
 843  * The sendmsg system call handler obtains the user data and stores it
 844  * in ctx->tsgl_list. This implies allocation of the required numbers of
 845  * struct af_alg_tsgl.
 846  *
 847  * In addition, the ctx is filled with the information sent via CMSG.
 848  *
 849  * @sock socket of connection to user space
 850  * @msg message from user space
 851  * @size size of message from user space
 852  * @ivsize the size of the IV for the cipher operation to verify that the
 853  *         user-space-provided IV has the right size
 854  * @return the number of copied data upon success, < 0 upon error
 855  */
 856 int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
 857                    unsigned int ivsize)
 858 {
 859         struct sock *sk = sock->sk;
 860         struct alg_sock *ask = alg_sk(sk);
 861         struct af_alg_ctx *ctx = ask->private;
 862         struct af_alg_tsgl *sgl;
 863         struct af_alg_control con = {};
 864         long copied = 0;
 865         bool enc = 0;
 866         bool init = 0;
 867         int err = 0;
 868
 869         if (msg->msg_controllen) {
 870                 err = af_alg_cmsg_send(msg, &con);
 871                 if (err)
 872                         return err;
 873
 874                 init = 1;
 875                 switch (con.op) {
 876                 case ALG_OP_ENCRYPT:
 877                         enc = 1;
 878                         break;
 879                 case ALG_OP_DECRYPT:
 880                         enc = 0;
 881                         break;
 882                 default:
 883                         return -EINVAL;
 884                 }
 885
 886                 if (con.iv && con.iv->ivlen != ivsize)
 887                         return -EINVAL;
 888         }
 889
 890         lock_sock(sk);
 891         if (!ctx->more && ctx->used) {
 892                 err = -EINVAL;
 893                 goto unlock;
 894         }
 895
 896         if (init) {
 897                 ctx->enc = enc;
 898                 if (con.iv)
 899                         memcpy(ctx->iv, con.iv->iv, ivsize);
 900
 901                 ctx->aead_assoclen = con.aead_assoclen;
 902         }
 903
 904         while (size) {
 905                 struct scatterlist *sg;
 906                 size_t len = size;
 907                 size_t plen;
 908
 909                 /* use the existing memory in an allocated page */
 910                 if (ctx->merge) {
 911                         sgl = list_entry(ctx->tsgl_list.prev,
 912                                          struct af_alg_tsgl, list);
 913                         sg = sgl->sg + sgl->cur - 1;
 914                         len = min_t(size_t, len,
 915                                     PAGE_SIZE - sg->offset - sg->length);
 916
 917                         err = memcpy_from_msg(page_address(sg_page(sg)) +
 918                                               sg->offset + sg->length,
 919                                               msg, len);
 920                         if (err)
 921                                 goto unlock;
 922
 923                         sg->length += len;
 924                         ctx->merge = (sg->offset + sg->length) &
 925                                      (PAGE_SIZE - 1);
 926
 927                         ctx->used += len;
 928                         copied += len;
 929                         size -= len;
 930                         continue;
 931                 }
 932
 933                 if (!af_alg_writable(sk)) {
 934                         err = af_alg_wait_for_wmem(sk, msg->msg_flags);
 935                         if (err)
 936                                 goto unlock;
 937                 }
 938
 939                 /* allocate a new page */
 940                 len = min_t(unsigned long, len, af_alg_sndbuf(sk));
 941
 942                 err = af_alg_alloc_tsgl(sk);
 943                 if (err)
 944                         goto unlock;
 945
 946                 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
 947                                  list);
 948                 sg = sgl->sg;
 949                 if (sgl->cur)
 950                         sg_unmark_end(sg + sgl->cur - 1);
 951
 952                 do {
 953                         unsigned int i = sgl->cur;
 954
 955                         plen = min_t(size_t, len, PAGE_SIZE);
 956
 957                         sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
 958                         if (!sg_page(sg + i)) {
 959                                 err = -ENOMEM;
 960                                 goto unlock;
 961                         }
 962
 963                         err = memcpy_from_msg(page_address(sg_page(sg + i)),
 964                                               msg, plen);
 965                         if (err) {
 966                                 __free_page(sg_page(sg + i));
 967                                 sg_assign_page(sg + i, NULL);
 968                                 goto unlock;
 969                         }
 970
 971                         sg[i].length = plen;
 972                         len -= plen;
 973                         ctx->used += plen;
 974                         copied += plen;
 975                         size -= plen;
 976                         sgl->cur++;
 977                 } while (len && sgl->cur < MAX_SGL_ENTS);
 978
 979                 if (!size)
 980                         sg_mark_end(sg + sgl->cur - 1);
 981
 982                 ctx->merge = plen & (PAGE_SIZE - 1);
 983         }
 984
 985         err = 0;
 986
 987         ctx->more = msg->msg_flags & MSG_MORE;
 988
 989 unlock:
 990         af_alg_data_wakeup(sk);
 991         release_sock(sk);
 992
 993         return copied ?: err;
 994 }
 995 EXPORT_SYMBOL_GPL(af_alg_sendmsg);
 996
 997 /**
 998  * af_alg_sendpage - sendpage system call handler
 999  *
1000  * This is a generic implementation of sendpage to fill ctx->tsgl_list.
1001  */
1002 ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
1003                         int offset, size_t size, int flags)
1004 {
1005         struct sock *sk = sock->sk;
1006         struct alg_sock *ask = alg_sk(sk);
1007         struct af_alg_ctx *ctx = ask->private;
1008         struct af_alg_tsgl *sgl;
1009         int err = -EINVAL;
1010
1011         if (flags & MSG_SENDPAGE_NOTLAST)
1012                 flags |= MSG_MORE;
1013
1014         lock_sock(sk);
1015         if (!ctx->more && ctx->used)
1016                 goto unlock;
1017
1018         if (!size)
1019                 goto done;
1020
1021         if (!af_alg_writable(sk)) {
1022                 err = af_alg_wait_for_wmem(sk, flags);
1023                 if (err)
1024                         goto unlock;
1025         }
1026
1027         err = af_alg_alloc_tsgl(sk);
1028         if (err)
1029                 goto unlock;
1030
1031         ctx->merge = 0;
1032         sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
1033
1034         if (sgl->cur)
1035                 sg_unmark_end(sgl->sg + sgl->cur - 1);
1036
1037         sg_mark_end(sgl->sg + sgl->cur);
1038
1039         get_page(page);
1040         sg_set_page(sgl->sg + sgl->cur, page, size, offset);
1041         sgl->cur++;
1042         ctx->used += size;
1043
1044 done:
1045         ctx->more = flags & MSG_MORE;
1046
1047 unlock:
1048         af_alg_data_wakeup(sk);
1049         release_sock(sk);
1050
1051         return err ?: size;
1052 }
1053 EXPORT_SYMBOL_GPL(af_alg_sendpage);
1054
1055 /**
1056  * af_alg_free_resources - release resources required for crypto request
1057  */
1058 void af_alg_free_resources(struct af_alg_async_req *areq)
1059 {
1060         struct sock *sk = areq->sk;
1061
1062         af_alg_free_areq_sgls(areq);
1063         sock_kfree_s(sk, areq, areq->areqlen);
1064 }
1065 EXPORT_SYMBOL_GPL(af_alg_free_resources);
1066
1067 /**
1068  * af_alg_async_cb - AIO callback handler
1069  *
1070  * This handler cleans up the struct af_alg_async_req upon completion of the
1071  * AIO operation.
1072  *
1073  * The number of bytes to be generated with the AIO operation must be set
1074  * in areq->outlen before the AIO callback handler is invoked.
1075  */
1076 void af_alg_async_cb(struct crypto_async_request *_req, int err)
1077 {
1078         struct af_alg_async_req *areq = _req->data;
1079         struct sock *sk = areq->sk;
1080         struct kiocb *iocb = areq->iocb;
1081         unsigned int resultlen;
1082
1083         /* Buffer size written by crypto operation. */
1084         resultlen = areq->outlen;
1085
1086         af_alg_free_resources(areq);
1087         sock_put(sk);
1088
1089         iocb->ki_complete(iocb, err ? err : resultlen, 0);
1090 }
1091 EXPORT_SYMBOL_GPL(af_alg_async_cb);
1092
1093 /**
1094  * af_alg_poll - poll system call handler
1095  */
1096 unsigned int af_alg_poll(struct file *file, struct socket *sock,
1097                          poll_table *wait)
1098 {
1099         struct sock *sk = sock->sk;
1100         struct alg_sock *ask = alg_sk(sk);
1101         struct af_alg_ctx *ctx = ask->private;
1102         unsigned int mask;
1103
1104         sock_poll_wait(file, sk_sleep(sk), wait);
1105         mask = 0;
1106
1107         if (!ctx->more || ctx->used)
1108                 mask |= POLLIN | POLLRDNORM;
1109
1110         if (af_alg_writable(sk))
1111                 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
1112
1113         return mask;
1114 }
1115 EXPORT_SYMBOL_GPL(af_alg_poll);
1116
1117 /**
1118  * af_alg_alloc_areq - allocate struct af_alg_async_req
1119  *
1120  * @sk socket of connection to user space
1121  * @areqlen size of struct af_alg_async_req + crypto_*_reqsize
1122  * @return allocated data structure or ERR_PTR upon error
1123  */
1124 struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
1125                                            unsigned int areqlen)
1126 {
1127         struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
1128
1129         if (unlikely(!areq))
1130                 return ERR_PTR(-ENOMEM);
1131
1132         areq->areqlen = areqlen;
1133         areq->sk = sk;
1134         areq->last_rsgl = NULL;
1135         INIT_LIST_HEAD(&areq->rsgl_list);
1136         areq->tsgl = NULL;
1137         areq->tsgl_entries = 0;
1138
1139         return areq;
1140 }
1141 EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
1142
1143 /**
1144  * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1145  *                   operation
1146  *
1147  * @sk socket of connection to user space
1148  * @msg user space message
1149  * @flags flags used to invoke recvmsg with
1150  * @areq instance of the cryptographic request that will hold the RX SGL
1151  * @maxsize maximum number of bytes to be pulled from user space
1152  * @outlen number of bytes in the RX SGL
1153  * @return 0 on success, < 0 upon error
1154  */
1155 int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
1156                     struct af_alg_async_req *areq, size_t maxsize,
1157                     size_t *outlen)
1158 {
1159         struct alg_sock *ask = alg_sk(sk);
1160         struct af_alg_ctx *ctx = ask->private;
1161         size_t len = 0;
1162
1163         while (maxsize > len && msg_data_left(msg)) {
1164                 struct af_alg_rsgl *rsgl;
1165                 size_t seglen;
1166                 int err;
1167
1168                 /* limit the amount of readable buffers */
1169                 if (!af_alg_readable(sk))
1170                         break;
1171
1172                 seglen = min_t(size_t, (maxsize - len),
1173                                msg_data_left(msg));
1174
1175                 if (list_empty(&areq->rsgl_list)) {
1176                         rsgl = &areq->first_rsgl;
1177                 } else {
1178                         rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
1179                         if (unlikely(!rsgl))
1180                                 return -ENOMEM;
1181                 }
1182
1183                 rsgl->sgl.npages = 0;
1184                 list_add_tail(&rsgl->list, &areq->rsgl_list);
1185
1186                 /* make one iovec available as scatterlist */
1187                 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
1188                 if (err < 0) {
1189                         rsgl->sg_num_bytes = 0;
1190                         return err;
1191                 }
1192
1193                 /* chain the new scatterlist with previous one */
1194                 if (areq->last_rsgl)
1195                         af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
1196
1197                 areq->last_rsgl = rsgl;
1198                 len += err;
1199                 atomic_add(err, &ctx->rcvused);
1200                 rsgl->sg_num_bytes = err;
1201                 iov_iter_advance(&msg->msg_iter, err);
1202         }
1203
1204         *outlen = len;
1205         return 0;
1206 }
1207 EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
1208
1209 static int __init af_alg_init(void)
1210 {
1211         int err = proto_register(&alg_proto, 0);
1212
1213         if (err)
1214                 goto out;
1215
1216         err = sock_register(&alg_family);
1217         if (err != 0)
1218                 goto out_unregister_proto;
1219
1220 out:
1221         return err;
1222
1223 out_unregister_proto:
1224         proto_unregister(&alg_proto);
1225         goto out;
1226 }
1227
1228 static void __exit af_alg_exit(void)
1229 {
1230         sock_unregister(PF_ALG);
1231         proto_unregister(&alg_proto);
1232 }
1233
1234 module_init(af_alg_init);
1235 module_exit(af_alg_exit);
1236 MODULE_LICENSE("GPL");
1237 MODULE_ALIAS_NETPROTO(AF_ALG);