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 key_put(key); 324 return PTR_ERR(ret); 325 } 326 327 key_data = sock_kmalloc(&ask->sk, key_datalen, GFP_KERNEL); 328 if (!key_data) { 329 up_read(&key->sem); 330 key_put(key); 331 return -ENOMEM; 332 } 333 334 memcpy(key_data, ret, key_datalen); 335 336 up_read(&key->sem); 337 key_put(key); 338 339 err = type->setkey(ask->private, key_data, key_datalen); 340 341 sock_kzfree_s(&ask->sk, key_data, key_datalen); 342 343 return err; 344 } 345 346 #else 347 348 static inline int alg_setkey_by_key_serial(struct alg_sock *ask, 349 sockptr_t optval, 350 unsigned int optlen) 351 { 352 return -ENOPROTOOPT; 353 } 354 355 #endif 356 357 static int alg_setsockopt(struct socket *sock, int level, int optname, 358 sockptr_t optval, unsigned int optlen) 359 { 360 struct sock *sk = sock->sk; 361 struct alg_sock *ask = alg_sk(sk); 362 const struct af_alg_type *type; 363 int err = -EBUSY; 364 365 lock_sock(sk); 366 if (atomic_read(&ask->refcnt) != atomic_read(&ask->nokey_refcnt)) 367 goto unlock; 368 369 type = ask->type; 370 371 err = -ENOPROTOOPT; 372 if (level != SOL_ALG || !type) 373 goto unlock; 374 375 switch (optname) { 376 case ALG_SET_KEY: 377 case ALG_SET_KEY_BY_KEY_SERIAL: 378 if (sock->state == SS_CONNECTED) 379 goto unlock; 380 if (!type->setkey) 381 goto unlock; 382 383 if (optname == ALG_SET_KEY_BY_KEY_SERIAL) 384 err = alg_setkey_by_key_serial(ask, optval, optlen); 385 else 386 err = alg_setkey(sk, optval, optlen); 387 break; 388 case ALG_SET_AEAD_AUTHSIZE: 389 if (sock->state == SS_CONNECTED) 390 goto unlock; 391 if (!type->setauthsize) 392 goto unlock; 393 err = type->setauthsize(ask->private, optlen); 394 break; 395 case ALG_SET_DRBG_ENTROPY: 396 if (sock->state == SS_CONNECTED) 397 goto unlock; 398 if (!type->setentropy) 399 goto unlock; 400 401 err = type->setentropy(ask->private, optval, optlen); 402 } 403 404 unlock: 405 release_sock(sk); 406 407 return err; 408 } 409 410 int af_alg_accept(struct sock *sk, struct socket *newsock, 411 struct proto_accept_arg *arg) 412 { 413 struct alg_sock *ask = alg_sk(sk); 414 const struct af_alg_type *type; 415 struct sock *sk2; 416 unsigned int nokey; 417 int err; 418 419 lock_sock(sk); 420 type = ask->type; 421 422 err = -EINVAL; 423 if (!type) 424 goto unlock; 425 426 sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, arg->kern); 427 err = -ENOMEM; 428 if (!sk2) 429 goto unlock; 430 431 sock_init_data(newsock, sk2); 432 security_sock_graft(sk2, newsock); 433 security_sk_clone(sk, sk2); 434 435 /* 436 * newsock->ops assigned here to allow type->accept call to override 437 * them when required. 438 */ 439 newsock->ops = type->ops; 440 err = type->accept(ask->private, sk2); 441 442 nokey = err == -ENOKEY; 443 if (nokey && type->accept_nokey) 444 err = type->accept_nokey(ask->private, sk2); 445 446 if (err) 447 goto unlock; 448 449 if (atomic_inc_return_relaxed(&ask->refcnt) == 1) 450 sock_hold(sk); 451 if (nokey) { 452 atomic_inc(&ask->nokey_refcnt); 453 atomic_set(&alg_sk(sk2)->nokey_refcnt, 1); 454 } 455 alg_sk(sk2)->parent = sk; 456 alg_sk(sk2)->type = type; 457 458 newsock->state = SS_CONNECTED; 459 460 if (nokey) 461 newsock->ops = type->ops_nokey; 462 463 err = 0; 464 465 unlock: 466 release_sock(sk); 467 468 return err; 469 } 470 EXPORT_SYMBOL_GPL(af_alg_accept); 471 472 static int alg_accept(struct socket *sock, struct socket *newsock, 473 struct proto_accept_arg *arg) 474 { 475 return af_alg_accept(sock->sk, newsock, arg); 476 } 477 478 static const struct proto_ops alg_proto_ops = { 479 .family = PF_ALG, 480 .owner = THIS_MODULE, 481 482 .connect = sock_no_connect, 483 .socketpair = sock_no_socketpair, 484 .getname = sock_no_getname, 485 .ioctl = sock_no_ioctl, 486 .listen = sock_no_listen, 487 .shutdown = sock_no_shutdown, 488 .mmap = sock_no_mmap, 489 .sendmsg = sock_no_sendmsg, 490 .recvmsg = sock_no_recvmsg, 491 492 .bind = alg_bind, 493 .release = af_alg_release, 494 .setsockopt = alg_setsockopt, 495 .accept = alg_accept, 496 }; 497 498 static void alg_sock_destruct(struct sock *sk) 499 { 500 struct alg_sock *ask = alg_sk(sk); 501 502 alg_do_release(ask->type, ask->private); 503 } 504 505 static int alg_create(struct net *net, struct socket *sock, int protocol, 506 int kern) 507 { 508 struct sock *sk; 509 int err; 510 511 if (sock->type != SOCK_SEQPACKET) 512 return -ESOCKTNOSUPPORT; 513 if (protocol != 0) 514 return -EPROTONOSUPPORT; 515 516 err = -ENOMEM; 517 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern); 518 if (!sk) 519 goto out; 520 521 sock->ops = &alg_proto_ops; 522 sock_init_data(sock, sk); 523 524 sk->sk_destruct = alg_sock_destruct; 525 526 return 0; 527 out: 528 return err; 529 } 530 531 static const struct net_proto_family alg_family = { 532 .family = PF_ALG, 533 .create = alg_create, 534 .owner = THIS_MODULE, 535 }; 536 537 static void af_alg_link_sg(struct af_alg_sgl *sgl_prev, 538 struct af_alg_sgl *sgl_new) 539 { 540 sg_unmark_end(sgl_prev->sgt.sgl + sgl_prev->sgt.nents - 1); 541 sg_chain(sgl_prev->sgt.sgl, sgl_prev->sgt.nents + 1, sgl_new->sgt.sgl); 542 } 543 544 void af_alg_free_sg(struct af_alg_sgl *sgl) 545 { 546 int i; 547 548 if (sgl->sgt.sgl) { 549 if (sgl->need_unpin) 550 for (i = 0; i < sgl->sgt.nents; i++) 551 unpin_user_page(sg_page(&sgl->sgt.sgl[i])); 552 if (sgl->sgt.sgl != sgl->sgl) 553 kvfree(sgl->sgt.sgl); 554 sgl->sgt.sgl = NULL; 555 } 556 } 557 EXPORT_SYMBOL_GPL(af_alg_free_sg); 558 559 static int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con) 560 { 561 struct cmsghdr *cmsg; 562 563 for_each_cmsghdr(cmsg, msg) { 564 if (!CMSG_OK(msg, cmsg)) 565 return -EINVAL; 566 if (cmsg->cmsg_level != SOL_ALG) 567 continue; 568 569 switch (cmsg->cmsg_type) { 570 case ALG_SET_IV: 571 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv))) 572 return -EINVAL; 573 con->iv = (void *)CMSG_DATA(cmsg); 574 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen + 575 sizeof(*con->iv))) 576 return -EINVAL; 577 break; 578 579 case ALG_SET_OP: 580 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32))) 581 return -EINVAL; 582 con->op = *(u32 *)CMSG_DATA(cmsg); 583 break; 584 585 case ALG_SET_AEAD_ASSOCLEN: 586 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32))) 587 return -EINVAL; 588 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg); 589 break; 590 591 default: 592 return -EINVAL; 593 } 594 } 595 596 return 0; 597 } 598 599 /** 600 * af_alg_alloc_tsgl - allocate the TX SGL 601 * 602 * @sk: socket of connection to user space 603 * Return: 0 upon success, < 0 upon error 604 */ 605 static int af_alg_alloc_tsgl(struct sock *sk) 606 { 607 struct alg_sock *ask = alg_sk(sk); 608 struct af_alg_ctx *ctx = ask->private; 609 struct af_alg_tsgl *sgl; 610 struct scatterlist *sg = NULL; 611 612 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list); 613 if (!list_empty(&ctx->tsgl_list)) 614 sg = sgl->sg; 615 616 if (!sg || sgl->cur >= MAX_SGL_ENTS) { 617 sgl = sock_kmalloc(sk, 618 struct_size(sgl, sg, (MAX_SGL_ENTS + 1)), 619 GFP_KERNEL); 620 if (!sgl) 621 return -ENOMEM; 622 623 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1); 624 sgl->cur = 0; 625 626 if (sg) 627 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg); 628 629 list_add_tail(&sgl->list, &ctx->tsgl_list); 630 } 631 632 return 0; 633 } 634 635 /** 636 * af_alg_count_tsgl - Count number of TX SG entries 637 * 638 * The counting starts from the beginning of the SGL to @bytes. If 639 * an @offset is provided, the counting of the SG entries starts at the @offset. 640 * 641 * @sk: socket of connection to user space 642 * @bytes: Count the number of SG entries holding given number of bytes. 643 * @offset: Start the counting of SG entries from the given offset. 644 * Return: Number of TX SG entries found given the constraints 645 */ 646 unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset) 647 { 648 const struct alg_sock *ask = alg_sk(sk); 649 const struct af_alg_ctx *ctx = ask->private; 650 const struct af_alg_tsgl *sgl; 651 unsigned int i; 652 unsigned int sgl_count = 0; 653 654 if (!bytes) 655 return 0; 656 657 list_for_each_entry(sgl, &ctx->tsgl_list, list) { 658 const struct scatterlist *sg = sgl->sg; 659 660 for (i = 0; i < sgl->cur; i++) { 661 size_t bytes_count; 662 663 /* Skip offset */ 664 if (offset >= sg[i].length) { 665 offset -= sg[i].length; 666 bytes -= sg[i].length; 667 continue; 668 } 669 670 bytes_count = sg[i].length - offset; 671 672 offset = 0; 673 sgl_count++; 674 675 /* If we have seen requested number of bytes, stop */ 676 if (bytes_count >= bytes) 677 return sgl_count; 678 679 bytes -= bytes_count; 680 } 681 } 682 683 return sgl_count; 684 } 685 EXPORT_SYMBOL_GPL(af_alg_count_tsgl); 686 687 /** 688 * af_alg_pull_tsgl - Release the specified buffers from TX SGL 689 * 690 * If @dst is non-null, reassign the pages to @dst. The caller must release 691 * the pages. If @dst_offset is given only reassign the pages to @dst starting 692 * at the @dst_offset (byte). The caller must ensure that @dst is large 693 * enough (e.g. by using af_alg_count_tsgl with the same offset). 694 * 695 * @sk: socket of connection to user space 696 * @used: Number of bytes to pull from TX SGL 697 * @dst: If non-NULL, buffer is reassigned to dst SGL instead of releasing. The 698 * caller must release the buffers in dst. 699 * @dst_offset: Reassign the TX SGL from given offset. All buffers before 700 * reaching the offset is released. 701 */ 702 void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst, 703 size_t dst_offset) 704 { 705 struct alg_sock *ask = alg_sk(sk); 706 struct af_alg_ctx *ctx = ask->private; 707 struct af_alg_tsgl *sgl; 708 struct scatterlist *sg; 709 unsigned int i, j = 0; 710 711 while (!list_empty(&ctx->tsgl_list)) { 712 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl, 713 list); 714 sg = sgl->sg; 715 716 for (i = 0; i < sgl->cur; i++) { 717 size_t plen = min_t(size_t, used, sg[i].length); 718 struct page *page = sg_page(sg + i); 719 720 if (!page) 721 continue; 722 723 /* 724 * Assumption: caller created af_alg_count_tsgl(len) 725 * SG entries in dst. 726 */ 727 if (dst) { 728 if (dst_offset >= plen) { 729 /* discard page before offset */ 730 dst_offset -= plen; 731 } else { 732 /* reassign page to dst after offset */ 733 get_page(page); 734 sg_set_page(dst + j, page, 735 plen - dst_offset, 736 sg[i].offset + dst_offset); 737 dst_offset = 0; 738 j++; 739 } 740 } 741 742 sg[i].length -= plen; 743 sg[i].offset += plen; 744 745 used -= plen; 746 ctx->used -= plen; 747 748 if (sg[i].length) 749 return; 750 751 put_page(page); 752 sg_assign_page(sg + i, NULL); 753 } 754 755 list_del(&sgl->list); 756 sock_kfree_s(sk, sgl, struct_size(sgl, sg, MAX_SGL_ENTS + 1)); 757 } 758 759 if (!ctx->used) 760 ctx->merge = 0; 761 ctx->init = ctx->more; 762 } 763 EXPORT_SYMBOL_GPL(af_alg_pull_tsgl); 764 765 /** 766 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request 767 * 768 * @areq: Request holding the TX and RX SGL 769 */ 770 static void af_alg_free_areq_sgls(struct af_alg_async_req *areq) 771 { 772 struct sock *sk = areq->sk; 773 struct alg_sock *ask = alg_sk(sk); 774 struct af_alg_ctx *ctx = ask->private; 775 struct af_alg_rsgl *rsgl, *tmp; 776 struct scatterlist *tsgl; 777 struct scatterlist *sg; 778 unsigned int i; 779 780 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) { 781 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused); 782 af_alg_free_sg(&rsgl->sgl); 783 list_del(&rsgl->list); 784 if (rsgl != &areq->first_rsgl) 785 sock_kfree_s(sk, rsgl, sizeof(*rsgl)); 786 } 787 788 tsgl = areq->tsgl; 789 if (tsgl) { 790 for_each_sg(tsgl, sg, areq->tsgl_entries, i) { 791 if (!sg_page(sg)) 792 continue; 793 put_page(sg_page(sg)); 794 } 795 796 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl)); 797 } 798 } 799 800 /** 801 * af_alg_wait_for_wmem - wait for availability of writable memory 802 * 803 * @sk: socket of connection to user space 804 * @flags: If MSG_DONTWAIT is set, then only report if function would sleep 805 * Return: 0 when writable memory is available, < 0 upon error 806 */ 807 static int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags) 808 { 809 DEFINE_WAIT_FUNC(wait, woken_wake_function); 810 int err = -ERESTARTSYS; 811 long timeout; 812 813 if (flags & MSG_DONTWAIT) 814 return -EAGAIN; 815 816 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk); 817 818 add_wait_queue(sk_sleep(sk), &wait); 819 for (;;) { 820 if (signal_pending(current)) 821 break; 822 timeout = MAX_SCHEDULE_TIMEOUT; 823 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) { 824 err = 0; 825 break; 826 } 827 } 828 remove_wait_queue(sk_sleep(sk), &wait); 829 830 return err; 831 } 832 833 /** 834 * af_alg_wmem_wakeup - wakeup caller when writable memory is available 835 * 836 * @sk: socket of connection to user space 837 */ 838 void af_alg_wmem_wakeup(struct sock *sk) 839 { 840 struct socket_wq *wq; 841 842 if (!af_alg_writable(sk)) 843 return; 844 845 rcu_read_lock(); 846 wq = rcu_dereference(sk->sk_wq); 847 if (skwq_has_sleeper(wq)) 848 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | 849 EPOLLRDNORM | 850 EPOLLRDBAND); 851 sk_wake_async_rcu(sk, SOCK_WAKE_WAITD, POLL_IN); 852 rcu_read_unlock(); 853 } 854 EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup); 855 856 /** 857 * af_alg_wait_for_data - wait for availability of TX data 858 * 859 * @sk: socket of connection to user space 860 * @flags: If MSG_DONTWAIT is set, then only report if function would sleep 861 * @min: Set to minimum request size if partial requests are allowed. 862 * Return: 0 when writable memory is available, < 0 upon error 863 */ 864 int af_alg_wait_for_data(struct sock *sk, unsigned flags, unsigned min) 865 { 866 DEFINE_WAIT_FUNC(wait, woken_wake_function); 867 struct alg_sock *ask = alg_sk(sk); 868 struct af_alg_ctx *ctx = ask->private; 869 long timeout; 870 int err = -ERESTARTSYS; 871 872 if (flags & MSG_DONTWAIT) 873 return -EAGAIN; 874 875 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk); 876 877 add_wait_queue(sk_sleep(sk), &wait); 878 for (;;) { 879 if (signal_pending(current)) 880 break; 881 timeout = MAX_SCHEDULE_TIMEOUT; 882 if (sk_wait_event(sk, &timeout, 883 ctx->init && (!ctx->more || 884 (min && ctx->used >= min)), 885 &wait)) { 886 err = 0; 887 break; 888 } 889 } 890 remove_wait_queue(sk_sleep(sk), &wait); 891 892 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk); 893 894 return err; 895 } 896 EXPORT_SYMBOL_GPL(af_alg_wait_for_data); 897 898 /** 899 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel 900 * 901 * @sk: socket of connection to user space 902 */ 903 static void af_alg_data_wakeup(struct sock *sk) 904 { 905 struct alg_sock *ask = alg_sk(sk); 906 struct af_alg_ctx *ctx = ask->private; 907 struct socket_wq *wq; 908 909 if (!ctx->used) 910 return; 911 912 rcu_read_lock(); 913 wq = rcu_dereference(sk->sk_wq); 914 if (skwq_has_sleeper(wq)) 915 wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT | 916 EPOLLRDNORM | 917 EPOLLRDBAND); 918 sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT); 919 rcu_read_unlock(); 920 } 921 922 /** 923 * af_alg_sendmsg - implementation of sendmsg system call handler 924 * 925 * The sendmsg system call handler obtains the user data and stores it 926 * in ctx->tsgl_list. This implies allocation of the required numbers of 927 * struct af_alg_tsgl. 928 * 929 * In addition, the ctx is filled with the information sent via CMSG. 930 * 931 * @sock: socket of connection to user space 932 * @msg: message from user space 933 * @size: size of message from user space 934 * @ivsize: the size of the IV for the cipher operation to verify that the 935 * user-space-provided IV has the right size 936 * Return: the number of copied data upon success, < 0 upon error 937 */ 938 int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size, 939 unsigned int ivsize) 940 { 941 struct sock *sk = sock->sk; 942 struct alg_sock *ask = alg_sk(sk); 943 struct af_alg_ctx *ctx = ask->private; 944 struct af_alg_tsgl *sgl; 945 struct af_alg_control con = {}; 946 long copied = 0; 947 bool enc = false; 948 bool init = false; 949 int err = 0; 950 951 if (msg->msg_controllen) { 952 err = af_alg_cmsg_send(msg, &con); 953 if (err) 954 return err; 955 956 init = true; 957 switch (con.op) { 958 case ALG_OP_ENCRYPT: 959 enc = true; 960 break; 961 case ALG_OP_DECRYPT: 962 enc = false; 963 break; 964 default: 965 return -EINVAL; 966 } 967 968 if (con.iv && con.iv->ivlen != ivsize) 969 return -EINVAL; 970 } 971 972 lock_sock(sk); 973 if (ctx->init && !ctx->more) { 974 if (ctx->used) { 975 err = -EINVAL; 976 goto unlock; 977 } 978 979 pr_info_once( 980 "%s sent an empty control message without MSG_MORE.\n", 981 current->comm); 982 } 983 ctx->init = true; 984 985 if (init) { 986 ctx->enc = enc; 987 if (con.iv) 988 memcpy(ctx->iv, con.iv->iv, ivsize); 989 990 ctx->aead_assoclen = con.aead_assoclen; 991 } 992 993 while (size) { 994 struct scatterlist *sg; 995 size_t len = size; 996 ssize_t plen; 997 998 /* use the existing memory in an allocated page */ 999 if (ctx->merge && !(msg->msg_flags & MSG_SPLICE_PAGES)) { 1000 sgl = list_entry(ctx->tsgl_list.prev, 1001 struct af_alg_tsgl, list); 1002 sg = sgl->sg + sgl->cur - 1; 1003 len = min_t(size_t, len, 1004 PAGE_SIZE - sg->offset - sg->length); 1005 1006 err = memcpy_from_msg(page_address(sg_page(sg)) + 1007 sg->offset + sg->length, 1008 msg, len); 1009 if (err) 1010 goto unlock; 1011 1012 sg->length += len; 1013 ctx->merge = (sg->offset + sg->length) & 1014 (PAGE_SIZE - 1); 1015 1016 ctx->used += len; 1017 copied += len; 1018 size -= len; 1019 continue; 1020 } 1021 1022 if (!af_alg_writable(sk)) { 1023 err = af_alg_wait_for_wmem(sk, msg->msg_flags); 1024 if (err) 1025 goto unlock; 1026 } 1027 1028 /* allocate a new page */ 1029 len = min_t(unsigned long, len, af_alg_sndbuf(sk)); 1030 1031 err = af_alg_alloc_tsgl(sk); 1032 if (err) 1033 goto unlock; 1034 1035 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, 1036 list); 1037 sg = sgl->sg; 1038 if (sgl->cur) 1039 sg_unmark_end(sg + sgl->cur - 1); 1040 1041 if (msg->msg_flags & MSG_SPLICE_PAGES) { 1042 struct sg_table sgtable = { 1043 .sgl = sg, 1044 .nents = sgl->cur, 1045 .orig_nents = sgl->cur, 1046 }; 1047 1048 plen = extract_iter_to_sg(&msg->msg_iter, len, &sgtable, 1049 MAX_SGL_ENTS - sgl->cur, 0); 1050 if (plen < 0) { 1051 err = plen; 1052 goto unlock; 1053 } 1054 1055 for (; sgl->cur < sgtable.nents; sgl->cur++) 1056 get_page(sg_page(&sg[sgl->cur])); 1057 len -= plen; 1058 ctx->used += plen; 1059 copied += plen; 1060 size -= plen; 1061 ctx->merge = 0; 1062 } else { 1063 do { 1064 struct page *pg; 1065 unsigned int i = sgl->cur; 1066 1067 plen = min_t(size_t, len, PAGE_SIZE); 1068 1069 pg = alloc_page(GFP_KERNEL); 1070 if (!pg) { 1071 err = -ENOMEM; 1072 goto unlock; 1073 } 1074 1075 sg_assign_page(sg + i, pg); 1076 1077 err = memcpy_from_msg( 1078 page_address(sg_page(sg + i)), 1079 msg, plen); 1080 if (err) { 1081 __free_page(sg_page(sg + i)); 1082 sg_assign_page(sg + i, NULL); 1083 goto unlock; 1084 } 1085 1086 sg[i].length = plen; 1087 len -= plen; 1088 ctx->used += plen; 1089 copied += plen; 1090 size -= plen; 1091 sgl->cur++; 1092 } while (len && sgl->cur < MAX_SGL_ENTS); 1093 1094 ctx->merge = plen & (PAGE_SIZE - 1); 1095 } 1096 1097 if (!size) 1098 sg_mark_end(sg + sgl->cur - 1); 1099 } 1100 1101 err = 0; 1102 1103 ctx->more = msg->msg_flags & MSG_MORE; 1104 1105 unlock: 1106 af_alg_data_wakeup(sk); 1107 release_sock(sk); 1108 1109 return copied ?: err; 1110 } 1111 EXPORT_SYMBOL_GPL(af_alg_sendmsg); 1112 1113 /** 1114 * af_alg_free_resources - release resources required for crypto request 1115 * @areq: Request holding the TX and RX SGL 1116 */ 1117 void af_alg_free_resources(struct af_alg_async_req *areq) 1118 { 1119 struct sock *sk = areq->sk; 1120 struct af_alg_ctx *ctx; 1121 1122 af_alg_free_areq_sgls(areq); 1123 sock_kfree_s(sk, areq, areq->areqlen); 1124 1125 ctx = alg_sk(sk)->private; 1126 ctx->inflight = false; 1127 } 1128 EXPORT_SYMBOL_GPL(af_alg_free_resources); 1129 1130 /** 1131 * af_alg_async_cb - AIO callback handler 1132 * @data: async request completion data 1133 * @err: if non-zero, error result to be returned via ki_complete(); 1134 * otherwise return the AIO output length via ki_complete(). 1135 * 1136 * This handler cleans up the struct af_alg_async_req upon completion of the 1137 * AIO operation. 1138 * 1139 * The number of bytes to be generated with the AIO operation must be set 1140 * in areq->outlen before the AIO callback handler is invoked. 1141 */ 1142 void af_alg_async_cb(void *data, int err) 1143 { 1144 struct af_alg_async_req *areq = data; 1145 struct sock *sk = areq->sk; 1146 struct kiocb *iocb = areq->iocb; 1147 unsigned int resultlen; 1148 1149 /* Buffer size written by crypto operation. */ 1150 resultlen = areq->outlen; 1151 1152 af_alg_free_resources(areq); 1153 sock_put(sk); 1154 1155 iocb->ki_complete(iocb, err ? err : (int)resultlen); 1156 } 1157 EXPORT_SYMBOL_GPL(af_alg_async_cb); 1158 1159 /** 1160 * af_alg_poll - poll system call handler 1161 * @file: file pointer 1162 * @sock: socket to poll 1163 * @wait: poll_table 1164 */ 1165 __poll_t af_alg_poll(struct file *file, struct socket *sock, 1166 poll_table *wait) 1167 { 1168 struct sock *sk = sock->sk; 1169 struct alg_sock *ask = alg_sk(sk); 1170 struct af_alg_ctx *ctx = ask->private; 1171 __poll_t mask; 1172 1173 sock_poll_wait(file, sock, wait); 1174 mask = 0; 1175 1176 if (!ctx->more || ctx->used) 1177 mask |= EPOLLIN | EPOLLRDNORM; 1178 1179 if (af_alg_writable(sk)) 1180 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND; 1181 1182 return mask; 1183 } 1184 EXPORT_SYMBOL_GPL(af_alg_poll); 1185 1186 /** 1187 * af_alg_alloc_areq - allocate struct af_alg_async_req 1188 * 1189 * @sk: socket of connection to user space 1190 * @areqlen: size of struct af_alg_async_req + crypto_*_reqsize 1191 * Return: allocated data structure or ERR_PTR upon error 1192 */ 1193 struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk, 1194 unsigned int areqlen) 1195 { 1196 struct af_alg_ctx *ctx = alg_sk(sk)->private; 1197 struct af_alg_async_req *areq; 1198 1199 /* Only one AIO request can be in flight. */ 1200 if (ctx->inflight) 1201 return ERR_PTR(-EBUSY); 1202 1203 areq = sock_kmalloc(sk, areqlen, GFP_KERNEL); 1204 if (unlikely(!areq)) 1205 return ERR_PTR(-ENOMEM); 1206 1207 ctx->inflight = true; 1208 1209 areq->areqlen = areqlen; 1210 areq->sk = sk; 1211 areq->first_rsgl.sgl.sgt.sgl = areq->first_rsgl.sgl.sgl; 1212 areq->last_rsgl = NULL; 1213 INIT_LIST_HEAD(&areq->rsgl_list); 1214 areq->tsgl = NULL; 1215 areq->tsgl_entries = 0; 1216 1217 return areq; 1218 } 1219 EXPORT_SYMBOL_GPL(af_alg_alloc_areq); 1220 1221 /** 1222 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto 1223 * operation 1224 * 1225 * @sk: socket of connection to user space 1226 * @msg: user space message 1227 * @flags: flags used to invoke recvmsg with 1228 * @areq: instance of the cryptographic request that will hold the RX SGL 1229 * @maxsize: maximum number of bytes to be pulled from user space 1230 * @outlen: number of bytes in the RX SGL 1231 * Return: 0 on success, < 0 upon error 1232 */ 1233 int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags, 1234 struct af_alg_async_req *areq, size_t maxsize, 1235 size_t *outlen) 1236 { 1237 struct alg_sock *ask = alg_sk(sk); 1238 struct af_alg_ctx *ctx = ask->private; 1239 size_t len = 0; 1240 1241 while (maxsize > len && msg_data_left(msg)) { 1242 struct af_alg_rsgl *rsgl; 1243 ssize_t err; 1244 size_t seglen; 1245 1246 /* limit the amount of readable buffers */ 1247 if (!af_alg_readable(sk)) 1248 break; 1249 1250 seglen = min_t(size_t, (maxsize - len), 1251 msg_data_left(msg)); 1252 1253 if (list_empty(&areq->rsgl_list)) { 1254 rsgl = &areq->first_rsgl; 1255 } else { 1256 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL); 1257 if (unlikely(!rsgl)) 1258 return -ENOMEM; 1259 } 1260 1261 rsgl->sgl.need_unpin = 1262 iov_iter_extract_will_pin(&msg->msg_iter); 1263 rsgl->sgl.sgt.sgl = rsgl->sgl.sgl; 1264 rsgl->sgl.sgt.nents = 0; 1265 rsgl->sgl.sgt.orig_nents = 0; 1266 list_add_tail(&rsgl->list, &areq->rsgl_list); 1267 1268 sg_init_table(rsgl->sgl.sgt.sgl, ALG_MAX_PAGES); 1269 err = extract_iter_to_sg(&msg->msg_iter, seglen, &rsgl->sgl.sgt, 1270 ALG_MAX_PAGES, 0); 1271 if (err < 0) { 1272 rsgl->sg_num_bytes = 0; 1273 return err; 1274 } 1275 1276 sg_mark_end(rsgl->sgl.sgt.sgl + rsgl->sgl.sgt.nents - 1); 1277 1278 /* chain the new scatterlist with previous one */ 1279 if (areq->last_rsgl) 1280 af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl); 1281 1282 areq->last_rsgl = rsgl; 1283 len += err; 1284 atomic_add(err, &ctx->rcvused); 1285 rsgl->sg_num_bytes = err; 1286 } 1287 1288 *outlen = len; 1289 return 0; 1290 } 1291 EXPORT_SYMBOL_GPL(af_alg_get_rsgl); 1292 1293 static int __init af_alg_init(void) 1294 { 1295 int err = proto_register(&alg_proto, 0); 1296 1297 if (err) 1298 goto out; 1299 1300 err = sock_register(&alg_family); 1301 if (err != 0) 1302 goto out_unregister_proto; 1303 1304 out: 1305 return err; 1306 1307 out_unregister_proto: 1308 proto_unregister(&alg_proto); 1309 goto out; 1310 } 1311 1312 static void __exit af_alg_exit(void) 1313 { 1314 sock_unregister(PF_ALG); 1315 proto_unregister(&alg_proto); 1316 } 1317 1318 module_init(af_alg_init); 1319 module_exit(af_alg_exit); 1320 MODULE_DESCRIPTION("Crypto userspace interface"); 1321 MODULE_LICENSE("GPL"); 1322 MODULE_ALIAS_NETPROTO(AF_ALG); 1323