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