crypto/af

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

DEFINITIONS
