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/key.h> 16 #include <linux/key-type.h> 17 #include <linux/list.h> 18 #include <linux/module.h> 19 #include <linux/net.h> 20 #include <linux/rwsem.h> 21 #include <linux/sched.h> 22 #include <linux/sched/signal.h> 23 #include <linux/security.h> 24 #include <linux/string.h> 25 #include <keys/user-type.h> 26 #include <keys/trusted-type.h> 27 #include <keys/encrypted-type.h> 28 29 struct alg_type_list { 30 const struct af_alg_type *type; 31 struct list_head list; 32 }; 33 34 static struct proto alg_proto = { 35 .name = "ALG", 36 .owner = THIS_MODULE, 37 .obj_size = sizeof(struct alg_sock), 38 }; 39 40 static LIST_HEAD(alg_types); 41 static DECLARE_RWSEM(alg_types_sem); 42 43 static const struct af_alg_type *alg_get_type(const char *name) 44 { 45 const struct af_alg_type *type = ERR_PTR(-ENOENT); 46 struct alg_type_list *node; 47 48 down_read(&alg_types_sem); 49 list_for_each_entry(node, &alg_types, list) { 50 if (strcmp(node->type->name, name)) 51 continue; 52 53 if (try_module_get(node->type->owner)) 54 type = node->type; 55 break; 56 } 57 up_read(&alg_types_sem); 58 59 return type; 60 } 61 62 int af_alg_register_type(const struct af_alg_type *type) 63 { 64 struct alg_type_list *node; 65 int err = -EEXIST; 66 67 down_write(&alg_types_sem); 68 list_for_each_entry(node, &alg_types, list) { 69 if (!strcmp(node->type->name, type->name)) 70 goto unlock; 71 } 72 73 node = kmalloc(sizeof(*node), GFP_KERNEL); 74 err = -ENOMEM; 75 if (!node) 76 goto unlock; 77 78 type->ops->owner = THIS_MODULE; 79 if (type->ops_nokey) 80 type->ops_nokey->owner = THIS_MODULE; 81 node->type = type; 82 list_add(&node->list, &alg_types); 83 err = 0; 84 85 unlock: 86 up_write(&alg_types_sem); 87 88 return err; 89 } 90 EXPORT_SYMBOL_GPL(af_alg_register_type); 91 92 int af_alg_unregister_type(const struct af_alg_type *type) 93 { 94 struct alg_type_list *node; 95 int err = -ENOENT; 96 97 down_write(&alg_types_sem); 98 list_for_each_entry(node, &alg_types, list) { 99 if (strcmp(node->type->name, type->name)) 100 continue; 101 102 list_del(&node->list); 103 kfree(node); 104 err = 0; 105 break; 106 } 107 up_write(&alg_types_sem); 108 109 return err; 110 } 111 EXPORT_SYMBOL_GPL(af_alg_unregister_type); 112 113 static void alg_do_release(const struct af_alg_type *type, void *private) 114 { 115 if (!type) 116 return; 117 118 type->release(private); 119 module_put(type->owner); 120 } 121 122 int af_alg_release(struct socket *sock) 123 { 124 if (sock->sk) { 125 sock_put(sock->sk); 126 sock->sk = NULL; 127 } 128 return 0; 129 } 130 EXPORT_SYMBOL_GPL(af_alg_release); 131 132 void af_alg_release_parent(struct sock *sk) 133 { 134 struct alg_sock *ask = alg_sk(sk); 135 unsigned int nokey = atomic_read(&ask->nokey_refcnt); 136 137 sk = ask->parent; 138 ask = alg_sk(sk); 139 140 if (nokey) 141 atomic_dec(&ask->nokey_refcnt); 142 143 if (atomic_dec_and_test(&ask->refcnt)) 144 sock_put(sk); 145 } 146 EXPORT_SYMBOL_GPL(af_alg_release_parent); 147 148 static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 149 { 150 const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY; 151 struct sock *sk = sock->sk; 152 struct alg_sock *ask = alg_sk(sk); 153 struct sockaddr_alg_new *sa = (void *)uaddr; 154 const struct af_alg_type *type; 155 void *private; 156 int err; 157 158 if (sock->state == SS_CONNECTED) 159 return -EINVAL; 160 161 BUILD_BUG_ON(offsetof(struct sockaddr_alg_new, salg_name) != 162 offsetof(struct sockaddr_alg, salg_name)); 163 BUILD_BUG_ON(offsetof(struct sockaddr_alg, salg_name) != sizeof(*sa)); 164 165 if (addr_len < sizeof(*sa) + 1) 166 return -EINVAL; 167 168 /* If caller uses non-allowed flag, return error. */ 169 if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed)) 170 return -EINVAL; 171 172 sa->salg_type[sizeof(sa->salg_type) - 1] = 0; 173 sa->salg_name[addr_len - sizeof(*sa) - 1] = 0; 174 175 type = alg_get_type(sa->salg_type); 176 if (PTR_ERR(type) == -ENOENT) { 177 request_module("algif-%s", sa->salg_type); 178 type = alg_get_type(sa->salg_type); 179 } 180 181 if (IS_ERR(type)) 182 return PTR_ERR(type); 183 184 private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask); 185 if (IS_ERR(private)) { 186 module_put(type->owner); 187 return PTR_ERR(private); 188 } 189 190 err = -EBUSY; 191 lock_sock(sk); 192 if (atomic_read(&ask->refcnt)) 193 goto unlock; 194 195 swap(ask->type, type); 196 swap(ask->private, private); 197 198 err = 0; 199 200 unlock: 201 release_sock(sk); 202 203 alg_do_release(type, private); 204 205 return err; 206 } 207 208 static int alg_setkey(struct sock *sk, sockptr_t ukey, 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_sockptr(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 #ifdef CONFIG_KEYS 232 233 static const u8 *key_data_ptr_user(const struct key *key, 234 unsigned int *datalen) 235 { 236 const struct user_key_payload *ukp; 237 238 ukp = user_key_payload_locked(key); 239 if (IS_ERR_OR_NULL(ukp)) 240 return ERR_PTR(-EKEYREVOKED); 241 242 *datalen = key->datalen; 243 244 return ukp->data; 245 } 246 247 static const u8 *key_data_ptr_encrypted(const struct key *key, 248 unsigned int *datalen) 249 { 250 const struct encrypted_key_payload *ekp; 251 252 ekp = dereference_key_locked(key); 253 if (IS_ERR_OR_NULL(ekp)) 254 return ERR_PTR(-EKEYREVOKED); 255 256 *datalen = ekp->decrypted_datalen; 257 258 return ekp->decrypted_data; 259 } 260 261 static const u8 *key_data_ptr_trusted(const struct key *key, 262 unsigned int *datalen) 263 { 264 const struct trusted_key_payload *tkp; 265 266 tkp = dereference_key_locked(key); 267 if (IS_ERR_OR_NULL(tkp)) 268 return ERR_PTR(-EKEYREVOKED); 269 270 *datalen = tkp->key_len; 271 272 return tkp->key; 273 } 274 275 static struct key *lookup_key(key_serial_t serial) 276 { 277 key_ref_t key_ref; 278 279 key_ref = lookup_user_key(serial, 0, KEY_NEED_SEARCH); 280 if (IS_ERR(key_ref)) 281 return ERR_CAST(key_ref); 282 283 return key_ref_to_ptr(key_ref); 284 } 285 286 static int alg_setkey_by_key_serial(struct alg_sock *ask, sockptr_t optval, 287 unsigned int optlen) 288 { 289 const struct af_alg_type *type = ask->type; 290 u8 *key_data = NULL; 291 unsigned int key_datalen; 292 key_serial_t serial; 293 struct key *key; 294 const u8 *ret; 295 int err; 296 297 if (optlen != sizeof(serial)) 298 return -EINVAL; 299 300 if (copy_from_sockptr(&serial, optval, optlen)) 301 return -EFAULT; 302 303 key = lookup_key(serial); 304 if (IS_ERR(key)) 305 return PTR_ERR(key); 306 307 down_read(&key->sem); 308 309 ret = ERR_PTR(-ENOPROTOOPT); 310 if (!strcmp(key->type->name, "user") || 311 !strcmp(key->type->name, "logon")) { 312 ret = key_data_ptr_user(key, &key_datalen); 313 } else if (IS_REACHABLE(CONFIG_ENCRYPTED_KEYS) && 314 !strcmp(key->type->name, "encrypted")) { 315 ret = key_data_ptr_encrypted(key, &key_datalen); 316 } else if (IS_REACHABLE(CONFIG_TRUSTED_KEYS) && 317 !strcmp(key->type->name, "trusted")) { 318 ret = key_data_ptr_trusted(key, &key_datalen); 319 } 320 321 if (IS_ERR(ret)) { 322 up_read(&key->sem); 323 return PTR_ERR(ret); 324 } 325 326 key_data = sock_kmalloc(&ask->sk, key_datalen, GFP_KERNEL); 327 if (!key_data) { 328 up_read(&key->sem); 329 return -ENOMEM; 330 } 331 332 memcpy(key_data, ret, key_datalen); 333 334 up_read(&key->sem); 335 336 err = type->setkey(ask->private, key_data, key_datalen); 337 338 sock_kzfree_s(&ask->sk, key_data, key_datalen); 339 340 return err; 341 } 342 343 #else 344 345 static inline int alg_setkey_by_key_serial(struct alg_sock *ask, 346 sockptr_t optval, 347 unsigned int optlen) 348 { 349 return -ENOPROTOOPT; 350 } 351 352 #endif 353 354 static int alg_setsockopt(struct socket *sock, int level, int optname, 355 sockptr_t optval, unsigned int optlen) 356 { 357 struct sock *sk = sock->sk; 358 struct alg_sock *ask = alg_sk(sk); 359 const struct af_alg_type *type; 360 int err = -EBUSY; 361 362 lock_sock(sk); 363 if (atomic_read(&ask->refcnt) != atomic_read(&ask->nokey_refcnt)) 364 goto unlock; 365 366 type = ask->type; 367 368 err = -ENOPROTOOPT; 369 if (level != SOL_ALG || !type) 370 goto unlock; 371 372 switch (optname) { 373 case ALG_SET_KEY: 374 case ALG_SET_KEY_BY_KEY_SERIAL: 375 if (sock->state == SS_CONNECTED) 376 goto unlock; 377 if (!type->setkey) 378 goto unlock; 379 380 if (optname == ALG_SET_KEY_BY_KEY_SERIAL) 381 err = alg_setkey_by_key_serial(ask, optval, optlen); 382 else 383 err = alg_setkey(sk, optval, optlen); 384 break; 385 case ALG_SET_AEAD_AUTHSIZE: 386 if (sock->state == SS_CONNECTED) 387 goto unlock; 388 if (!type->setauthsize) 389 goto unlock; 390 err = type->setauthsize(ask->private, optlen); 391 break; 392 case ALG_SET_DRBG_ENTROPY: 393 if (sock->state == SS_CONNECTED) 394 goto unlock; 395 if (!type->setentropy) 396 goto unlock; 397 398 err = type->setentropy(ask->private, optval, optlen); 399 } 400 401 unlock: 402 release_sock(sk); 403 404 return err; 405 } 406 407 int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern) 408 { 409 struct alg_sock *ask = alg_sk(sk); 410 const struct af_alg_type *type; 411 struct sock *sk2; 412 unsigned int nokey; 413 int err; 414 415 lock_sock(sk); 416 type = ask->type; 417 418 err = -EINVAL; 419 if (!type) 420 goto unlock; 421 422 sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, kern); 423 err = -ENOMEM; 424 if (!sk2) 425 goto unlock; 426 427 sock_init_data(newsock, sk2); 428 security_sock_graft(sk2, newsock); 429 security_sk_clone(sk, sk2); 430 431 /* 432 * newsock->ops assigned here to allow type->accept call to override 433 * them when required. 434 */ 435 newsock->ops = type->ops; 436 err = type->accept(ask->private, sk2); 437 438 nokey = err == -ENOKEY; 439 if (nokey && type->accept_nokey) 440 err = type->accept_nokey(ask->private, sk2); 441 442 if (err) 443 goto unlock; 444 445 if (atomic_inc_return_relaxed(&ask->refcnt) == 1) 446 sock_hold(sk); 447 if (nokey) { 448 atomic_inc(&ask->nokey_refcnt); 449 atomic_set(&alg_sk(sk2)->nokey_refcnt, 1); 450 } 451 alg_sk(sk2)->parent = sk; 452 alg_sk(sk2)->type = type; 453 454 newsock->state = SS_CONNECTED; 455 456 if (nokey) 457 newsock->ops = type->ops_nokey; 458 459 err = 0; 460 461 unlock: 462 release_sock(sk); 463 464 return err; 465 } 466 EXPORT_SYMBOL_GPL(af_alg_accept); 467 468 static int alg_accept(struct socket *sock, struct socket *newsock, int flags, 469 bool kern) 470 { 471 return af_alg_accept(sock->sk, newsock, kern); 472 } 473 474 static const struct proto_ops alg_proto_ops = { 475 .family = PF_ALG, 476 .owner = THIS_MODULE, 477 478 .connect = sock_no_connect, 479 .socketpair = sock_no_socketpair, 480 .getname = sock_no_getname, 481 .ioctl = sock_no_ioctl, 482 .listen = sock_no_listen, 483 .shutdown = sock_no_shutdown, 484 .mmap = sock_no_mmap, 485 .sendpage = sock_no_sendpage, 486 .sendmsg = sock_no_sendmsg, 487 .recvmsg = sock_no_recvmsg, 488 489 .bind = alg_bind, 490 .release = af_alg_release, 491 .setsockopt = alg_setsockopt, 492 .accept = alg_accept, 493 }; 494 495 static void alg_sock_destruct(struct sock *sk) 496 { 497 struct alg_sock *ask = alg_sk(sk); 498 499 alg_do_release(ask->type, ask->private); 500 } 501 502 static int alg_create(struct net *net, struct socket *sock, int protocol, 503 int kern) 504 { 505 struct sock *sk; 506 int err; 507 508 if (sock->type != SOCK_SEQPACKET) 509 return -ESOCKTNOSUPPORT; 510 if (protocol != 0) 511 return -EPROTONOSUPPORT; 512 513 err = -ENOMEM; 514 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern); 515 if (!sk) 516 goto out; 517 518 sock->ops = &alg_proto_ops; 519 sock_init_data(sock, sk); 520 521 sk->sk_destruct = alg_sock_destruct; 522 523 return 0; 524 out: 525 return err; 526 } 527 528 static const struct net_proto_family alg_family = { 529 .family = PF_ALG, 530 .create = alg_create, 531 .owner = THIS_MODULE, 532 }; 533 534 int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len) 535 { 536 struct page **pages = sgl->pages; 537 size_t off; 538 ssize_t n; 539 int npages, i; 540 541 n = iov_iter_extract_pages(iter, &pages, len, ALG_MAX_PAGES, 0, &off); 542 if (n < 0) 543 return n; 544 545 sgl->need_unpin = iov_iter_extract_will_pin(iter); 546 547 npages = DIV_ROUND_UP(off + n, PAGE_SIZE); 548 if (WARN_ON(npages == 0)) 549 return -EINVAL; 550 /* Add one extra for linking */ 551 sg_init_table(sgl->sg, npages + 1); 552 553 for (i = 0, len = n; i < npages; i++) { 554 int plen = min_t(int, len, PAGE_SIZE - off); 555 556 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off); 557 558 off = 0; 559 len -= plen; 560 } 561 sg_mark_end(sgl->sg + npages - 1); 562 sgl->npages = npages; 563 564 return n; 565 } 566 EXPORT_SYMBOL_GPL(af_alg_make_sg); 567 568 static void af_alg_link_sg(struct af_alg_sgl *sgl_prev, 569 struct af_alg_sgl *sgl_new) 570 { 571 sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1); 572 sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg); 573 } 574 575 void af_alg_free_sg(struct af_alg_sgl *sgl) 576 { 577 int i; 578 579 if (sgl->need_unpin) 580 for (i = 0; i < sgl->npages; i++) 581 unpin_user_page(sgl->pages[i]); 582 } 583 EXPORT_SYMBOL_GPL(af_alg_free_sg); 584 585 static int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con) 586 { 587 struct cmsghdr *cmsg; 588 589 for_each_cmsghdr(cmsg, msg) { 590 if (!CMSG_OK(msg, cmsg)) 591 return -EINVAL; 592 if (cmsg->cmsg_level != SOL_ALG) 593 continue; 594 595 switch (cmsg->cmsg_type) { 596 case ALG_SET_IV: 597 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv))) 598 return -EINVAL; 599 con->iv = (void *)CMSG_DATA(cmsg); 600 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen + 601 sizeof(*con->iv))) 602 return -EINVAL; 603 break; 604 605 case ALG_SET_OP: 606 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32))) 607 return -EINVAL; 608 con->op = *(u32 *)CMSG_DATA(cmsg); 609 break; 610 611 case ALG_SET_AEAD_ASSOCLEN: 612 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32))) 613 return -EINVAL; 614 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg); 615 break; 616 617 default: 618 return -EINVAL; 619 } 620 } 621 622 return 0; 623 } 624 625 /** 626 * af_alg_alloc_tsgl - allocate the TX SGL 627 * 628 * @sk: socket of connection to user space 629 * Return: 0 upon success, < 0 upon error 630 */ 631 static int af_alg_alloc_tsgl(struct sock *sk) 632 { 633 struct alg_sock *ask = alg_sk(sk); 634 struct af_alg_ctx *ctx = ask->private; 635 struct af_alg_tsgl *sgl; 636 struct scatterlist *sg = NULL; 637 638 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list); 639 if (!list_empty(&ctx->tsgl_list)) 640 sg = sgl->sg; 641 642 if (!sg || sgl->cur >= MAX_SGL_ENTS) { 643 sgl = sock_kmalloc(sk, 644 struct_size(sgl, sg, (MAX_SGL_ENTS + 1)), 645 GFP_KERNEL); 646 if (!sgl) 647 return -ENOMEM; 648 649 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1); 650 sgl->cur = 0; 651 652 if (sg) 653 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg); 654 655 list_add_tail(&sgl->list, &ctx->tsgl_list); 656 } 657 658 return 0; 659 } 660 661 /** 662 * af_alg_count_tsgl - Count number of TX SG entries 663 * 664 * The counting starts from the beginning of the SGL to @bytes. If 665 * an @offset is provided, the counting of the SG entries starts at the @offset. 666 * 667 * @sk: socket of connection to user space 668 * @bytes: Count the number of SG entries holding given number of bytes. 669 * @offset: Start the counting of SG entries from the given offset. 670 * Return: Number of TX SG entries found given the constraints 671 */ 672 unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset) 673 { 674 const struct alg_sock *ask = alg_sk(sk); 675 const struct af_alg_ctx *ctx = ask->private; 676 const struct af_alg_tsgl *sgl; 677 unsigned int i; 678 unsigned int sgl_count = 0; 679 680 if (!bytes) 681 return 0; 682 683 list_for_each_entry(sgl, &ctx->tsgl_list, list) { 684 const struct scatterlist *sg = sgl->sg; 685 686 for (i = 0; i < sgl->cur; i++) { 687 size_t bytes_count; 688 689 /* Skip offset */ 690 if (offset >= sg[i].length) { 691 offset -= sg[i].length; 692 bytes -= sg[i].length; 693 continue; 694 } 695 696 bytes_count = sg[i].length - offset; 697 698 offset = 0; 699 sgl_count++; 700 701 /* If we have seen requested number of bytes, stop */ 702 if (bytes_count >= bytes) 703 return sgl_count; 704 705 bytes -= bytes_count; 706 } 707 } 708 709 return sgl_count; 710 } 711 EXPORT_SYMBOL_GPL(af_alg_count_tsgl); 712 713 /** 714 * af_alg_pull_tsgl - Release the specified buffers from TX SGL 715 * 716 * If @dst is non-null, reassign the pages to @dst. The caller must release 717 * the pages. If @dst_offset is given only reassign the pages to @dst starting 718 * at the @dst_offset (byte). The caller must ensure that @dst is large 719 * enough (e.g. by using af_alg_count_tsgl with the same offset). 720 * 721 * @sk: socket of connection to user space 722 * @used: Number of bytes to pull from TX SGL 723 * @dst: If non-NULL, buffer is reassigned to dst SGL instead of releasing. The 724 * caller must release the buffers in dst. 725 * @dst_offset: Reassign the TX SGL from given offset. All buffers before 726 * reaching the offset is released. 727 */ 728 void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst, 729 size_t dst_offset) 730 { 731 struct alg_sock *ask = alg_sk(sk); 732 struct af_alg_ctx *ctx = ask->private; 733 struct af_alg_tsgl *sgl; 734 struct scatterlist *sg; 735 unsigned int i, j = 0; 736 737 while (!list_empty(&ctx->tsgl_list)) { 738 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl, 739 list); 740 sg = sgl->sg; 741 742 for (i = 0; i < sgl->cur; i++) { 743 size_t plen = min_t(size_t, used, sg[i].length); 744 struct page *page = sg_page(sg + i); 745 746 if (!page) 747 continue; 748 749 /* 750 * Assumption: caller created af_alg_count_tsgl(len) 751 * SG entries in dst. 752 */ 753 if (dst) { 754 if (dst_offset >= plen) { 755 /* discard page before offset */ 756 dst_offset -= plen; 757 } else { 758 /* reassign page to dst after offset */ 759 get_page(page); 760 sg_set_page(dst + j, page, 761 plen - dst_offset, 762 sg[i].offset + dst_offset); 763 dst_offset = 0; 764 j++; 765 } 766 } 767 768 sg[i].length -= plen; 769 sg[i].offset += plen; 770 771 used -= plen; 772 ctx->used -= plen; 773 774 if (sg[i].length) 775 return; 776 777 put_page(page); 778 sg_assign_page(sg + i, NULL); 779 } 780 781 list_del(&sgl->list); 782 sock_kfree_s(sk, sgl, struct_size(sgl, sg, MAX_SGL_ENTS + 1)); 783 } 784 785 if (!ctx->used) 786 ctx->merge = 0; 787 ctx->init = ctx->more; 788 } 789 EXPORT_SYMBOL_GPL(af_alg_pull_tsgl); 790 791 /** 792 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request 793 * 794 * @areq: Request holding the TX and RX SGL 795 */ 796 static void af_alg_free_areq_sgls(struct af_alg_async_req *areq) 797 { 798 struct sock *sk = areq->sk; 799 struct alg_sock *ask = alg_sk(sk); 800 struct af_alg_ctx *ctx = ask->private; 801 struct af_alg_rsgl *rsgl, *tmp; 802 struct scatterlist *tsgl; 803 struct scatterlist *sg; 804 unsigned int i; 805 806 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) { 807 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused); 808 af_alg_free_sg(&rsgl->sgl); 809 list_del(&rsgl->list); 810 if (rsgl != &areq->first_rsgl) 811 sock_kfree_s(sk, rsgl, sizeof(*rsgl)); 812 } 813 814 tsgl = areq->tsgl; 815 if (tsgl) { 816 for_each_sg(tsgl, sg, areq->tsgl_entries, i) { 817 if (!sg_page(sg)) 818 continue; 819 put_page(sg_page(sg)); 820 } 821 822 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl)); 823 } 824 } 825 826 /** 827 * af_alg_wait_for_wmem - wait for availability of writable memory 828 * 829 * @sk: socket of connection to user space 830 * @flags: If MSG_DONTWAIT is set, then only report if function would sleep 831 * Return: 0 when writable memory is available, < 0 upon error 832 */ 833 static int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags) 834 { 835 DEFINE_WAIT_FUNC(wait, woken_wake_function); 836 int err = -ERESTARTSYS; 837 long timeout; 838 839 if (flags & MSG_DONTWAIT) 840 return -EAGAIN; 841 842 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk); 843 844 add_wait_queue(sk_sleep(sk), &wait); 845 for (;;) { 846 if (signal_pending(current)) 847 break; 848 timeout = MAX_SCHEDULE_TIMEOUT; 849 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) { 850 err = 0; 851 break; 852 } 853 } 854 remove_wait_queue(sk_sleep(sk), &wait); 855 856 return err; 857 } 858 859 /** 860 * af_alg_wmem_wakeup - wakeup caller when writable memory is available 861 * 862 * @sk: socket of connection to user space 863 */ 864 void af_alg_wmem_wakeup(struct sock *sk) 865 { 866 struct socket_wq *wq; 867 868 if (!af_alg_writable(sk)) 869 return; 870 871 rcu_read_lock(); 872 wq = rcu_dereference(sk->sk_wq); 873 if (skwq_has_sleeper(wq)) 874 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | 875 EPOLLRDNORM | 876 EPOLLRDBAND); 877 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN); 878 rcu_read_unlock(); 879 } 880 EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup); 881 882 /** 883 * af_alg_wait_for_data - wait for availability of TX data 884 * 885 * @sk: socket of connection to user space 886 * @flags: If MSG_DONTWAIT is set, then only report if function would sleep 887 * @min: Set to minimum request size if partial requests are allowed. 888 * Return: 0 when writable memory is available, < 0 upon error 889 */ 890 int af_alg_wait_for_data(struct sock *sk, unsigned flags, unsigned min) 891 { 892 DEFINE_WAIT_FUNC(wait, woken_wake_function); 893 struct alg_sock *ask = alg_sk(sk); 894 struct af_alg_ctx *ctx = ask->private; 895 long timeout; 896 int err = -ERESTARTSYS; 897 898 if (flags & MSG_DONTWAIT) 899 return -EAGAIN; 900 901 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk); 902 903 add_wait_queue(sk_sleep(sk), &wait); 904 for (;;) { 905 if (signal_pending(current)) 906 break; 907 timeout = MAX_SCHEDULE_TIMEOUT; 908 if (sk_wait_event(sk, &timeout, 909 ctx->init && (!ctx->more || 910 (min && ctx->used >= min)), 911 &wait)) { 912 err = 0; 913 break; 914 } 915 } 916 remove_wait_queue(sk_sleep(sk), &wait); 917 918 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk); 919 920 return err; 921 } 922 EXPORT_SYMBOL_GPL(af_alg_wait_for_data); 923 924 /** 925 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel 926 * 927 * @sk: socket of connection to user space 928 */ 929 static void af_alg_data_wakeup(struct sock *sk) 930 { 931 struct alg_sock *ask = alg_sk(sk); 932 struct af_alg_ctx *ctx = ask->private; 933 struct socket_wq *wq; 934 935 if (!ctx->used) 936 return; 937 938 rcu_read_lock(); 939 wq = rcu_dereference(sk->sk_wq); 940 if (skwq_has_sleeper(wq)) 941 wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT | 942 EPOLLRDNORM | 943 EPOLLRDBAND); 944 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); 945 rcu_read_unlock(); 946 } 947 948 /** 949 * af_alg_sendmsg - implementation of sendmsg system call handler 950 * 951 * The sendmsg system call handler obtains the user data and stores it 952 * in ctx->tsgl_list. This implies allocation of the required numbers of 953 * struct af_alg_tsgl. 954 * 955 * In addition, the ctx is filled with the information sent via CMSG. 956 * 957 * @sock: socket of connection to user space 958 * @msg: message from user space 959 * @size: size of message from user space 960 * @ivsize: the size of the IV for the cipher operation to verify that the 961 * user-space-provided IV has the right size 962 * Return: the number of copied data upon success, < 0 upon error 963 */ 964 int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size, 965 unsigned int ivsize) 966 { 967 struct sock *sk = sock->sk; 968 struct alg_sock *ask = alg_sk(sk); 969 struct af_alg_ctx *ctx = ask->private; 970 struct af_alg_tsgl *sgl; 971 struct af_alg_control con = {}; 972 long copied = 0; 973 bool enc = false; 974 bool init = false; 975 int err = 0; 976 977 if (msg->msg_controllen) { 978 err = af_alg_cmsg_send(msg, &con); 979 if (err) 980 return err; 981 982 init = true; 983 switch (con.op) { 984 case ALG_OP_ENCRYPT: 985 enc = true; 986 break; 987 case ALG_OP_DECRYPT: 988 enc = false; 989 break; 990 default: 991 return -EINVAL; 992 } 993 994 if (con.iv && con.iv->ivlen != ivsize) 995 return -EINVAL; 996 } 997 998 lock_sock(sk); 999 if (ctx->init && !ctx->more) { 1000 if (ctx->used) { 1001 err = -EINVAL; 1002 goto unlock; 1003 } 1004 1005 pr_info_once( 1006 "%s sent an empty control message without MSG_MORE.\n", 1007 current->comm); 1008 } 1009 ctx->init = true; 1010 1011 if (init) { 1012 ctx->enc = enc; 1013 if (con.iv) 1014 memcpy(ctx->iv, con.iv->iv, ivsize); 1015 1016 ctx->aead_assoclen = con.aead_assoclen; 1017 } 1018 1019 while (size) { 1020 struct scatterlist *sg; 1021 size_t len = size; 1022 size_t plen; 1023 1024 /* use the existing memory in an allocated page */ 1025 if (ctx->merge) { 1026 sgl = list_entry(ctx->tsgl_list.prev, 1027 struct af_alg_tsgl, list); 1028 sg = sgl->sg + sgl->cur - 1; 1029 len = min_t(size_t, len, 1030 PAGE_SIZE - sg->offset - sg->length); 1031 1032 err = memcpy_from_msg(page_address(sg_page(sg)) + 1033 sg->offset + sg->length, 1034 msg, len); 1035 if (err) 1036 goto unlock; 1037 1038 sg->length += len; 1039 ctx->merge = (sg->offset + sg->length) & 1040 (PAGE_SIZE - 1); 1041 1042 ctx->used += len; 1043 copied += len; 1044 size -= len; 1045 continue; 1046 } 1047 1048 if (!af_alg_writable(sk)) { 1049 err = af_alg_wait_for_wmem(sk, msg->msg_flags); 1050 if (err) 1051 goto unlock; 1052 } 1053 1054 /* allocate a new page */ 1055 len = min_t(unsigned long, len, af_alg_sndbuf(sk)); 1056 1057 err = af_alg_alloc_tsgl(sk); 1058 if (err) 1059 goto unlock; 1060 1061 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, 1062 list); 1063 sg = sgl->sg; 1064 if (sgl->cur) 1065 sg_unmark_end(sg + sgl->cur - 1); 1066 1067 do { 1068 struct page *pg; 1069 unsigned int i = sgl->cur; 1070 1071 plen = min_t(size_t, len, PAGE_SIZE); 1072 1073 pg = alloc_page(GFP_KERNEL); 1074 if (!pg) { 1075 err = -ENOMEM; 1076 goto unlock; 1077 } 1078 1079 sg_assign_page(sg + i, pg); 1080 1081 err = memcpy_from_msg(page_address(sg_page(sg + i)), 1082 msg, plen); 1083 if (err) { 1084 __free_page(sg_page(sg + i)); 1085 sg_assign_page(sg + i, NULL); 1086 goto unlock; 1087 } 1088 1089 sg[i].length = plen; 1090 len -= plen; 1091 ctx->used += plen; 1092 copied += plen; 1093 size -= plen; 1094 sgl->cur++; 1095 } while (len && sgl->cur < MAX_SGL_ENTS); 1096 1097 if (!size) 1098 sg_mark_end(sg + sgl->cur - 1); 1099 1100 ctx->merge = plen & (PAGE_SIZE - 1); 1101 } 1102 1103 err = 0; 1104 1105 ctx->more = msg->msg_flags & MSG_MORE; 1106 1107 unlock: 1108 af_alg_data_wakeup(sk); 1109 release_sock(sk); 1110 1111 return copied ?: err; 1112 } 1113 EXPORT_SYMBOL_GPL(af_alg_sendmsg); 1114 1115 /** 1116 * af_alg_sendpage - sendpage system call handler 1117 * @sock: socket of connection to user space to write to 1118 * @page: data to send 1119 * @offset: offset into page to begin sending 1120 * @size: length of data 1121 * @flags: message send/receive flags 1122 * 1123 * This is a generic implementation of sendpage to fill ctx->tsgl_list. 1124 */ 1125 ssize_t af_alg_sendpage(struct socket *sock, struct page *page, 1126 int offset, size_t size, int flags) 1127 { 1128 struct sock *sk = sock->sk; 1129 struct alg_sock *ask = alg_sk(sk); 1130 struct af_alg_ctx *ctx = ask->private; 1131 struct af_alg_tsgl *sgl; 1132 int err = -EINVAL; 1133 1134 if (flags & MSG_SENDPAGE_NOTLAST) 1135 flags |= MSG_MORE; 1136 1137 lock_sock(sk); 1138 if (!ctx->more && ctx->used) 1139 goto unlock; 1140 1141 if (!size) 1142 goto done; 1143 1144 if (!af_alg_writable(sk)) { 1145 err = af_alg_wait_for_wmem(sk, flags); 1146 if (err) 1147 goto unlock; 1148 } 1149 1150 err = af_alg_alloc_tsgl(sk); 1151 if (err) 1152 goto unlock; 1153 1154 ctx->merge = 0; 1155 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list); 1156 1157 if (sgl->cur) 1158 sg_unmark_end(sgl->sg + sgl->cur - 1); 1159 1160 sg_mark_end(sgl->sg + sgl->cur); 1161 1162 get_page(page); 1163 sg_set_page(sgl->sg + sgl->cur, page, size, offset); 1164 sgl->cur++; 1165 ctx->used += size; 1166 1167 done: 1168 ctx->more = flags & MSG_MORE; 1169 1170 unlock: 1171 af_alg_data_wakeup(sk); 1172 release_sock(sk); 1173 1174 return err ?: size; 1175 } 1176 EXPORT_SYMBOL_GPL(af_alg_sendpage); 1177 1178 /** 1179 * af_alg_free_resources - release resources required for crypto request 1180 * @areq: Request holding the TX and RX SGL 1181 */ 1182 void af_alg_free_resources(struct af_alg_async_req *areq) 1183 { 1184 struct sock *sk = areq->sk; 1185 1186 af_alg_free_areq_sgls(areq); 1187 sock_kfree_s(sk, areq, areq->areqlen); 1188 } 1189 EXPORT_SYMBOL_GPL(af_alg_free_resources); 1190 1191 /** 1192 * af_alg_async_cb - AIO callback handler 1193 * @data: async request completion data 1194 * @err: if non-zero, error result to be returned via ki_complete(); 1195 * otherwise return the AIO output length via ki_complete(). 1196 * 1197 * This handler cleans up the struct af_alg_async_req upon completion of the 1198 * AIO operation. 1199 * 1200 * The number of bytes to be generated with the AIO operation must be set 1201 * in areq->outlen before the AIO callback handler is invoked. 1202 */ 1203 void af_alg_async_cb(void *data, int err) 1204 { 1205 struct af_alg_async_req *areq = data; 1206 struct sock *sk = areq->sk; 1207 struct kiocb *iocb = areq->iocb; 1208 unsigned int resultlen; 1209 1210 /* Buffer size written by crypto operation. */ 1211 resultlen = areq->outlen; 1212 1213 af_alg_free_resources(areq); 1214 sock_put(sk); 1215 1216 iocb->ki_complete(iocb, err ? err : (int)resultlen); 1217 } 1218 EXPORT_SYMBOL_GPL(af_alg_async_cb); 1219 1220 /** 1221 * af_alg_poll - poll system call handler 1222 * @file: file pointer 1223 * @sock: socket to poll 1224 * @wait: poll_table 1225 */ 1226 __poll_t af_alg_poll(struct file *file, struct socket *sock, 1227 poll_table *wait) 1228 { 1229 struct sock *sk = sock->sk; 1230 struct alg_sock *ask = alg_sk(sk); 1231 struct af_alg_ctx *ctx = ask->private; 1232 __poll_t mask; 1233 1234 sock_poll_wait(file, sock, wait); 1235 mask = 0; 1236 1237 if (!ctx->more || ctx->used) 1238 mask |= EPOLLIN | EPOLLRDNORM; 1239 1240 if (af_alg_writable(sk)) 1241 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND; 1242 1243 return mask; 1244 } 1245 EXPORT_SYMBOL_GPL(af_alg_poll); 1246 1247 /** 1248 * af_alg_alloc_areq - allocate struct af_alg_async_req 1249 * 1250 * @sk: socket of connection to user space 1251 * @areqlen: size of struct af_alg_async_req + crypto_*_reqsize 1252 * Return: allocated data structure or ERR_PTR upon error 1253 */ 1254 struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk, 1255 unsigned int areqlen) 1256 { 1257 struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL); 1258 1259 if (unlikely(!areq)) 1260 return ERR_PTR(-ENOMEM); 1261 1262 areq->areqlen = areqlen; 1263 areq->sk = sk; 1264 areq->last_rsgl = NULL; 1265 INIT_LIST_HEAD(&areq->rsgl_list); 1266 areq->tsgl = NULL; 1267 areq->tsgl_entries = 0; 1268 1269 return areq; 1270 } 1271 EXPORT_SYMBOL_GPL(af_alg_alloc_areq); 1272 1273 /** 1274 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto 1275 * operation 1276 * 1277 * @sk: socket of connection to user space 1278 * @msg: user space message 1279 * @flags: flags used to invoke recvmsg with 1280 * @areq: instance of the cryptographic request that will hold the RX SGL 1281 * @maxsize: maximum number of bytes to be pulled from user space 1282 * @outlen: number of bytes in the RX SGL 1283 * Return: 0 on success, < 0 upon error 1284 */ 1285 int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags, 1286 struct af_alg_async_req *areq, size_t maxsize, 1287 size_t *outlen) 1288 { 1289 struct alg_sock *ask = alg_sk(sk); 1290 struct af_alg_ctx *ctx = ask->private; 1291 size_t len = 0; 1292 1293 while (maxsize > len && msg_data_left(msg)) { 1294 struct af_alg_rsgl *rsgl; 1295 size_t seglen; 1296 int err; 1297 1298 /* limit the amount of readable buffers */ 1299 if (!af_alg_readable(sk)) 1300 break; 1301 1302 seglen = min_t(size_t, (maxsize - len), 1303 msg_data_left(msg)); 1304 1305 if (list_empty(&areq->rsgl_list)) { 1306 rsgl = &areq->first_rsgl; 1307 } else { 1308 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL); 1309 if (unlikely(!rsgl)) 1310 return -ENOMEM; 1311 } 1312 1313 rsgl->sgl.npages = 0; 1314 list_add_tail(&rsgl->list, &areq->rsgl_list); 1315 1316 /* make one iovec available as scatterlist */ 1317 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen); 1318 if (err < 0) { 1319 rsgl->sg_num_bytes = 0; 1320 return err; 1321 } 1322 1323 /* chain the new scatterlist with previous one */ 1324 if (areq->last_rsgl) 1325 af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl); 1326 1327 areq->last_rsgl = rsgl; 1328 len += err; 1329 atomic_add(err, &ctx->rcvused); 1330 rsgl->sg_num_bytes = err; 1331 } 1332 1333 *outlen = len; 1334 return 0; 1335 } 1336 EXPORT_SYMBOL_GPL(af_alg_get_rsgl); 1337 1338 static int __init af_alg_init(void) 1339 { 1340 int err = proto_register(&alg_proto, 0); 1341 1342 if (err) 1343 goto out; 1344 1345 err = sock_register(&alg_family); 1346 if (err != 0) 1347 goto out_unregister_proto; 1348 1349 out: 1350 return err; 1351 1352 out_unregister_proto: 1353 proto_unregister(&alg_proto); 1354 goto out; 1355 } 1356 1357 static void __exit af_alg_exit(void) 1358 { 1359 sock_unregister(PF_ALG); 1360 proto_unregister(&alg_proto); 1361 } 1362 1363 module_init(af_alg_init); 1364 module_exit(af_alg_exit); 1365 MODULE_LICENSE("GPL"); 1366 MODULE_ALIAS_NETPROTO(AF_ALG); 1367