1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * af_alg: User-space algorithm interface 4 * 5 * This file provides the user-space API for algorithms. 6 * 7 * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au> 8 */ 9 10 #include <linux/atomic.h> 11 #include <crypto/if_alg.h> 12 #include <linux/crypto.h> 13 #include <linux/init.h> 14 #include <linux/kernel.h> 15 #include <linux/list.h> 16 #include <linux/module.h> 17 #include <linux/net.h> 18 #include <linux/rwsem.h> 19 #include <linux/sched/signal.h> 20 #include <linux/security.h> 21 22 struct alg_type_list { 23 const struct af_alg_type *type; 24 struct list_head list; 25 }; 26 27 static atomic_long_t alg_memory_allocated; 28 29 static struct proto alg_proto = { 30 .name = "ALG", 31 .owner = THIS_MODULE, 32 .memory_allocated = &alg_memory_allocated, 33 .obj_size = sizeof(struct alg_sock), 34 }; 35 36 static LIST_HEAD(alg_types); 37 static DECLARE_RWSEM(alg_types_sem); 38 39 static const struct af_alg_type *alg_get_type(const char *name) 40 { 41 const struct af_alg_type *type = ERR_PTR(-ENOENT); 42 struct alg_type_list *node; 43 44 down_read(&alg_types_sem); 45 list_for_each_entry(node, &alg_types, list) { 46 if (strcmp(node->type->name, name)) 47 continue; 48 49 if (try_module_get(node->type->owner)) 50 type = node->type; 51 break; 52 } 53 up_read(&alg_types_sem); 54 55 return type; 56 } 57 58 int af_alg_register_type(const struct af_alg_type *type) 59 { 60 struct alg_type_list *node; 61 int err = -EEXIST; 62 63 down_write(&alg_types_sem); 64 list_for_each_entry(node, &alg_types, list) { 65 if (!strcmp(node->type->name, type->name)) 66 goto unlock; 67 } 68 69 node = kmalloc(sizeof(*node), GFP_KERNEL); 70 err = -ENOMEM; 71 if (!node) 72 goto unlock; 73 74 type->ops->owner = THIS_MODULE; 75 if (type->ops_nokey) 76 type->ops_nokey->owner = THIS_MODULE; 77 node->type = type; 78 list_add(&node->list, &alg_types); 79 err = 0; 80 81 unlock: 82 up_write(&alg_types_sem); 83 84 return err; 85 } 86 EXPORT_SYMBOL_GPL(af_alg_register_type); 87 88 int af_alg_unregister_type(const struct af_alg_type *type) 89 { 90 struct alg_type_list *node; 91 int err = -ENOENT; 92 93 down_write(&alg_types_sem); 94 list_for_each_entry(node, &alg_types, list) { 95 if (strcmp(node->type->name, type->name)) 96 continue; 97 98 list_del(&node->list); 99 kfree(node); 100 err = 0; 101 break; 102 } 103 up_write(&alg_types_sem); 104 105 return err; 106 } 107 EXPORT_SYMBOL_GPL(af_alg_unregister_type); 108 109 static void alg_do_release(const struct af_alg_type *type, void *private) 110 { 111 if (!type) 112 return; 113 114 type->release(private); 115 module_put(type->owner); 116 } 117 118 int af_alg_release(struct socket *sock) 119 { 120 if (sock->sk) { 121 sock_put(sock->sk); 122 sock->sk = NULL; 123 } 124 return 0; 125 } 126 EXPORT_SYMBOL_GPL(af_alg_release); 127 128 void af_alg_release_parent(struct sock *sk) 129 { 130 struct alg_sock *ask = alg_sk(sk); 131 unsigned int nokey = atomic_read(&ask->nokey_refcnt); 132 133 sk = ask->parent; 134 ask = alg_sk(sk); 135 136 if (nokey) 137 atomic_dec(&ask->nokey_refcnt); 138 139 if (atomic_dec_and_test(&ask->refcnt)) 140 sock_put(sk); 141 } 142 EXPORT_SYMBOL_GPL(af_alg_release_parent); 143 144 static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 145 { 146 const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY; 147 struct sock *sk = sock->sk; 148 struct alg_sock *ask = alg_sk(sk); 149 struct sockaddr_alg *sa = (void *)uaddr; 150 const struct af_alg_type *type; 151 void *private; 152 int err; 153 154 if (sock->state == SS_CONNECTED) 155 return -EINVAL; 156 157 if (addr_len < sizeof(*sa)) 158 return -EINVAL; 159 160 /* If caller uses non-allowed flag, return error. */ 161 if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed)) 162 return -EINVAL; 163 164 sa->salg_type[sizeof(sa->salg_type) - 1] = 0; 165 sa->salg_name[sizeof(sa->salg_name) + addr_len - sizeof(*sa) - 1] = 0; 166 167 type = alg_get_type(sa->salg_type); 168 if (PTR_ERR(type) == -ENOENT) { 169 request_module("algif-%s", sa->salg_type); 170 type = alg_get_type(sa->salg_type); 171 } 172 173 if (IS_ERR(type)) 174 return PTR_ERR(type); 175 176 private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask); 177 if (IS_ERR(private)) { 178 module_put(type->owner); 179 return PTR_ERR(private); 180 } 181 182 err = -EBUSY; 183 lock_sock(sk); 184 if (atomic_read(&ask->refcnt)) 185 goto unlock; 186 187 swap(ask->type, type); 188 swap(ask->private, private); 189 190 err = 0; 191 192 unlock: 193 release_sock(sk); 194 195 alg_do_release(type, private); 196 197 return err; 198 } 199 200 static int alg_setkey(struct sock *sk, char __user *ukey, 201 unsigned int keylen) 202 { 203 struct alg_sock *ask = alg_sk(sk); 204 const struct af_alg_type *type = ask->type; 205 u8 *key; 206 int err; 207 208 key = sock_kmalloc(sk, keylen, GFP_KERNEL); 209 if (!key) 210 return -ENOMEM; 211 212 err = -EFAULT; 213 if (copy_from_user(key, ukey, keylen)) 214 goto out; 215 216 err = type->setkey(ask->private, key, keylen); 217 218 out: 219 sock_kzfree_s(sk, key, keylen); 220 221 return err; 222 } 223 224 static int alg_setsockopt(struct socket *sock, int level, int optname, 225 char __user *optval, unsigned int optlen) 226 { 227 struct sock *sk = sock->sk; 228 struct alg_sock *ask = alg_sk(sk); 229 const struct af_alg_type *type; 230 int err = -EBUSY; 231 232 lock_sock(sk); 233 if (atomic_read(&ask->refcnt) != atomic_read(&ask->nokey_refcnt)) 234 goto unlock; 235 236 type = ask->type; 237 238 err = -ENOPROTOOPT; 239 if (level != SOL_ALG || !type) 240 goto unlock; 241 242 switch (optname) { 243 case ALG_SET_KEY: 244 if (sock->state == SS_CONNECTED) 245 goto unlock; 246 if (!type->setkey) 247 goto unlock; 248 249 err = alg_setkey(sk, optval, optlen); 250 break; 251 case ALG_SET_AEAD_AUTHSIZE: 252 if (sock->state == SS_CONNECTED) 253 goto unlock; 254 if (!type->setauthsize) 255 goto unlock; 256 err = type->setauthsize(ask->private, optlen); 257 } 258 259 unlock: 260 release_sock(sk); 261 262 return err; 263 } 264 265 int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern) 266 { 267 struct alg_sock *ask = alg_sk(sk); 268 const struct af_alg_type *type; 269 struct sock *sk2; 270 unsigned int nokey; 271 int err; 272 273 lock_sock(sk); 274 type = ask->type; 275 276 err = -EINVAL; 277 if (!type) 278 goto unlock; 279 280 sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, kern); 281 err = -ENOMEM; 282 if (!sk2) 283 goto unlock; 284 285 sock_init_data(newsock, sk2); 286 security_sock_graft(sk2, newsock); 287 security_sk_clone(sk, sk2); 288 289 err = type->accept(ask->private, sk2); 290 291 nokey = err == -ENOKEY; 292 if (nokey && type->accept_nokey) 293 err = type->accept_nokey(ask->private, sk2); 294 295 if (err) 296 goto unlock; 297 298 if (atomic_inc_return_relaxed(&ask->refcnt) == 1) 299 sock_hold(sk); 300 if (nokey) { 301 atomic_inc(&ask->nokey_refcnt); 302 atomic_set(&alg_sk(sk2)->nokey_refcnt, 1); 303 } 304 alg_sk(sk2)->parent = sk; 305 alg_sk(sk2)->type = type; 306 307 newsock->ops = type->ops; 308 newsock->state = SS_CONNECTED; 309 310 if (nokey) 311 newsock->ops = type->ops_nokey; 312 313 err = 0; 314 315 unlock: 316 release_sock(sk); 317 318 return err; 319 } 320 EXPORT_SYMBOL_GPL(af_alg_accept); 321 322 static int alg_accept(struct socket *sock, struct socket *newsock, int flags, 323 bool kern) 324 { 325 return af_alg_accept(sock->sk, newsock, kern); 326 } 327 328 static const struct proto_ops alg_proto_ops = { 329 .family = PF_ALG, 330 .owner = THIS_MODULE, 331 332 .connect = sock_no_connect, 333 .socketpair = sock_no_socketpair, 334 .getname = sock_no_getname, 335 .ioctl = sock_no_ioctl, 336 .listen = sock_no_listen, 337 .shutdown = sock_no_shutdown, 338 .getsockopt = sock_no_getsockopt, 339 .mmap = sock_no_mmap, 340 .sendpage = sock_no_sendpage, 341 .sendmsg = sock_no_sendmsg, 342 .recvmsg = sock_no_recvmsg, 343 344 .bind = alg_bind, 345 .release = af_alg_release, 346 .setsockopt = alg_setsockopt, 347 .accept = alg_accept, 348 }; 349 350 static void alg_sock_destruct(struct sock *sk) 351 { 352 struct alg_sock *ask = alg_sk(sk); 353 354 alg_do_release(ask->type, ask->private); 355 } 356 357 static int alg_create(struct net *net, struct socket *sock, int protocol, 358 int kern) 359 { 360 struct sock *sk; 361 int err; 362 363 if (sock->type != SOCK_SEQPACKET) 364 return -ESOCKTNOSUPPORT; 365 if (protocol != 0) 366 return -EPROTONOSUPPORT; 367 368 err = -ENOMEM; 369 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern); 370 if (!sk) 371 goto out; 372 373 sock->ops = &alg_proto_ops; 374 sock_init_data(sock, sk); 375 376 sk->sk_destruct = alg_sock_destruct; 377 378 return 0; 379 out: 380 return err; 381 } 382 383 static const struct net_proto_family alg_family = { 384 .family = PF_ALG, 385 .create = alg_create, 386 .owner = THIS_MODULE, 387 }; 388 389 int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len) 390 { 391 size_t off; 392 ssize_t n; 393 int npages, i; 394 395 n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off); 396 if (n < 0) 397 return n; 398 399 npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT; 400 if (WARN_ON(npages == 0)) 401 return -EINVAL; 402 /* Add one extra for linking */ 403 sg_init_table(sgl->sg, npages + 1); 404 405 for (i = 0, len = n; i < npages; i++) { 406 int plen = min_t(int, len, PAGE_SIZE - off); 407 408 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off); 409 410 off = 0; 411 len -= plen; 412 } 413 sg_mark_end(sgl->sg + npages - 1); 414 sgl->npages = npages; 415 416 return n; 417 } 418 EXPORT_SYMBOL_GPL(af_alg_make_sg); 419 420 static void af_alg_link_sg(struct af_alg_sgl *sgl_prev, 421 struct af_alg_sgl *sgl_new) 422 { 423 sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1); 424 sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg); 425 } 426 427 void af_alg_free_sg(struct af_alg_sgl *sgl) 428 { 429 int i; 430 431 for (i = 0; i < sgl->npages; i++) 432 put_page(sgl->pages[i]); 433 } 434 EXPORT_SYMBOL_GPL(af_alg_free_sg); 435 436 static int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con) 437 { 438 struct cmsghdr *cmsg; 439 440 for_each_cmsghdr(cmsg, msg) { 441 if (!CMSG_OK(msg, cmsg)) 442 return -EINVAL; 443 if (cmsg->cmsg_level != SOL_ALG) 444 continue; 445 446 switch (cmsg->cmsg_type) { 447 case ALG_SET_IV: 448 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv))) 449 return -EINVAL; 450 con->iv = (void *)CMSG_DATA(cmsg); 451 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen + 452 sizeof(*con->iv))) 453 return -EINVAL; 454 break; 455 456 case ALG_SET_OP: 457 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32))) 458 return -EINVAL; 459 con->op = *(u32 *)CMSG_DATA(cmsg); 460 break; 461 462 case ALG_SET_AEAD_ASSOCLEN: 463 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32))) 464 return -EINVAL; 465 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg); 466 break; 467 468 default: 469 return -EINVAL; 470 } 471 } 472 473 return 0; 474 } 475 476 /** 477 * af_alg_alloc_tsgl - allocate the TX SGL 478 * 479 * @sk socket of connection to user space 480 * @return: 0 upon success, < 0 upon error 481 */ 482 static int af_alg_alloc_tsgl(struct sock *sk) 483 { 484 struct alg_sock *ask = alg_sk(sk); 485 struct af_alg_ctx *ctx = ask->private; 486 struct af_alg_tsgl *sgl; 487 struct scatterlist *sg = NULL; 488 489 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list); 490 if (!list_empty(&ctx->tsgl_list)) 491 sg = sgl->sg; 492 493 if (!sg || sgl->cur >= MAX_SGL_ENTS) { 494 sgl = sock_kmalloc(sk, 495 struct_size(sgl, sg, (MAX_SGL_ENTS + 1)), 496 GFP_KERNEL); 497 if (!sgl) 498 return -ENOMEM; 499 500 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1); 501 sgl->cur = 0; 502 503 if (sg) 504 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg); 505 506 list_add_tail(&sgl->list, &ctx->tsgl_list); 507 } 508 509 return 0; 510 } 511 512 /** 513 * aead_count_tsgl - Count number of TX SG entries 514 * 515 * The counting starts from the beginning of the SGL to @bytes. If 516 * an offset is provided, the counting of the SG entries starts at the offset. 517 * 518 * @sk socket of connection to user space 519 * @bytes Count the number of SG entries holding given number of bytes. 520 * @offset Start the counting of SG entries from the given offset. 521 * @return Number of TX SG entries found given the constraints 522 */ 523 unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset) 524 { 525 const struct alg_sock *ask = alg_sk(sk); 526 const struct af_alg_ctx *ctx = ask->private; 527 const struct af_alg_tsgl *sgl; 528 unsigned int i; 529 unsigned int sgl_count = 0; 530 531 if (!bytes) 532 return 0; 533 534 list_for_each_entry(sgl, &ctx->tsgl_list, list) { 535 const struct scatterlist *sg = sgl->sg; 536 537 for (i = 0; i < sgl->cur; i++) { 538 size_t bytes_count; 539 540 /* Skip offset */ 541 if (offset >= sg[i].length) { 542 offset -= sg[i].length; 543 bytes -= sg[i].length; 544 continue; 545 } 546 547 bytes_count = sg[i].length - offset; 548 549 offset = 0; 550 sgl_count++; 551 552 /* If we have seen requested number of bytes, stop */ 553 if (bytes_count >= bytes) 554 return sgl_count; 555 556 bytes -= bytes_count; 557 } 558 } 559 560 return sgl_count; 561 } 562 EXPORT_SYMBOL_GPL(af_alg_count_tsgl); 563 564 /** 565 * aead_pull_tsgl - Release the specified buffers from TX SGL 566 * 567 * If @dst is non-null, reassign the pages to dst. The caller must release 568 * the pages. If @dst_offset is given only reassign the pages to @dst starting 569 * at the @dst_offset (byte). The caller must ensure that @dst is large 570 * enough (e.g. by using af_alg_count_tsgl with the same offset). 571 * 572 * @sk socket of connection to user space 573 * @used Number of bytes to pull from TX SGL 574 * @dst If non-NULL, buffer is reassigned to dst SGL instead of releasing. The 575 * caller must release the buffers in dst. 576 * @dst_offset Reassign the TX SGL from given offset. All buffers before 577 * reaching the offset is released. 578 */ 579 void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst, 580 size_t dst_offset) 581 { 582 struct alg_sock *ask = alg_sk(sk); 583 struct af_alg_ctx *ctx = ask->private; 584 struct af_alg_tsgl *sgl; 585 struct scatterlist *sg; 586 unsigned int i, j = 0; 587 588 while (!list_empty(&ctx->tsgl_list)) { 589 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl, 590 list); 591 sg = sgl->sg; 592 593 for (i = 0; i < sgl->cur; i++) { 594 size_t plen = min_t(size_t, used, sg[i].length); 595 struct page *page = sg_page(sg + i); 596 597 if (!page) 598 continue; 599 600 /* 601 * Assumption: caller created af_alg_count_tsgl(len) 602 * SG entries in dst. 603 */ 604 if (dst) { 605 if (dst_offset >= plen) { 606 /* discard page before offset */ 607 dst_offset -= plen; 608 } else { 609 /* reassign page to dst after offset */ 610 get_page(page); 611 sg_set_page(dst + j, page, 612 plen - dst_offset, 613 sg[i].offset + dst_offset); 614 dst_offset = 0; 615 j++; 616 } 617 } 618 619 sg[i].length -= plen; 620 sg[i].offset += plen; 621 622 used -= plen; 623 ctx->used -= plen; 624 625 if (sg[i].length) 626 return; 627 628 put_page(page); 629 sg_assign_page(sg + i, NULL); 630 } 631 632 list_del(&sgl->list); 633 sock_kfree_s(sk, sgl, struct_size(sgl, sg, MAX_SGL_ENTS + 1)); 634 } 635 636 if (!ctx->used) 637 ctx->merge = 0; 638 } 639 EXPORT_SYMBOL_GPL(af_alg_pull_tsgl); 640 641 /** 642 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request 643 * 644 * @areq Request holding the TX and RX SGL 645 */ 646 static void af_alg_free_areq_sgls(struct af_alg_async_req *areq) 647 { 648 struct sock *sk = areq->sk; 649 struct alg_sock *ask = alg_sk(sk); 650 struct af_alg_ctx *ctx = ask->private; 651 struct af_alg_rsgl *rsgl, *tmp; 652 struct scatterlist *tsgl; 653 struct scatterlist *sg; 654 unsigned int i; 655 656 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) { 657 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused); 658 af_alg_free_sg(&rsgl->sgl); 659 list_del(&rsgl->list); 660 if (rsgl != &areq->first_rsgl) 661 sock_kfree_s(sk, rsgl, sizeof(*rsgl)); 662 } 663 664 tsgl = areq->tsgl; 665 if (tsgl) { 666 for_each_sg(tsgl, sg, areq->tsgl_entries, i) { 667 if (!sg_page(sg)) 668 continue; 669 put_page(sg_page(sg)); 670 } 671 672 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl)); 673 } 674 } 675 676 /** 677 * af_alg_wait_for_wmem - wait for availability of writable memory 678 * 679 * @sk socket of connection to user space 680 * @flags If MSG_DONTWAIT is set, then only report if function would sleep 681 * @return 0 when writable memory is available, < 0 upon error 682 */ 683 static int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags) 684 { 685 DEFINE_WAIT_FUNC(wait, woken_wake_function); 686 int err = -ERESTARTSYS; 687 long timeout; 688 689 if (flags & MSG_DONTWAIT) 690 return -EAGAIN; 691 692 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk); 693 694 add_wait_queue(sk_sleep(sk), &wait); 695 for (;;) { 696 if (signal_pending(current)) 697 break; 698 timeout = MAX_SCHEDULE_TIMEOUT; 699 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) { 700 err = 0; 701 break; 702 } 703 } 704 remove_wait_queue(sk_sleep(sk), &wait); 705 706 return err; 707 } 708 709 /** 710 * af_alg_wmem_wakeup - wakeup caller when writable memory is available 711 * 712 * @sk socket of connection to user space 713 */ 714 void af_alg_wmem_wakeup(struct sock *sk) 715 { 716 struct socket_wq *wq; 717 718 if (!af_alg_writable(sk)) 719 return; 720 721 rcu_read_lock(); 722 wq = rcu_dereference(sk->sk_wq); 723 if (skwq_has_sleeper(wq)) 724 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | 725 EPOLLRDNORM | 726 EPOLLRDBAND); 727 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN); 728 rcu_read_unlock(); 729 } 730 EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup); 731 732 /** 733 * af_alg_wait_for_data - wait for availability of TX data 734 * 735 * @sk socket of connection to user space 736 * @flags If MSG_DONTWAIT is set, then only report if function would sleep 737 * @return 0 when writable memory is available, < 0 upon error 738 */ 739 int af_alg_wait_for_data(struct sock *sk, unsigned flags) 740 { 741 DEFINE_WAIT_FUNC(wait, woken_wake_function); 742 struct alg_sock *ask = alg_sk(sk); 743 struct af_alg_ctx *ctx = ask->private; 744 long timeout; 745 int err = -ERESTARTSYS; 746 747 if (flags & MSG_DONTWAIT) 748 return -EAGAIN; 749 750 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk); 751 752 add_wait_queue(sk_sleep(sk), &wait); 753 for (;;) { 754 if (signal_pending(current)) 755 break; 756 timeout = MAX_SCHEDULE_TIMEOUT; 757 if (sk_wait_event(sk, &timeout, (ctx->used || !ctx->more), 758 &wait)) { 759 err = 0; 760 break; 761 } 762 } 763 remove_wait_queue(sk_sleep(sk), &wait); 764 765 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk); 766 767 return err; 768 } 769 EXPORT_SYMBOL_GPL(af_alg_wait_for_data); 770 771 /** 772 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel 773 * 774 * @sk socket of connection to user space 775 */ 776 static void af_alg_data_wakeup(struct sock *sk) 777 { 778 struct alg_sock *ask = alg_sk(sk); 779 struct af_alg_ctx *ctx = ask->private; 780 struct socket_wq *wq; 781 782 if (!ctx->used) 783 return; 784 785 rcu_read_lock(); 786 wq = rcu_dereference(sk->sk_wq); 787 if (skwq_has_sleeper(wq)) 788 wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT | 789 EPOLLRDNORM | 790 EPOLLRDBAND); 791 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); 792 rcu_read_unlock(); 793 } 794 795 /** 796 * af_alg_sendmsg - implementation of sendmsg system call handler 797 * 798 * The sendmsg system call handler obtains the user data and stores it 799 * in ctx->tsgl_list. This implies allocation of the required numbers of 800 * struct af_alg_tsgl. 801 * 802 * In addition, the ctx is filled with the information sent via CMSG. 803 * 804 * @sock socket of connection to user space 805 * @msg message from user space 806 * @size size of message from user space 807 * @ivsize the size of the IV for the cipher operation to verify that the 808 * user-space-provided IV has the right size 809 * @return the number of copied data upon success, < 0 upon error 810 */ 811 int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size, 812 unsigned int ivsize) 813 { 814 struct sock *sk = sock->sk; 815 struct alg_sock *ask = alg_sk(sk); 816 struct af_alg_ctx *ctx = ask->private; 817 struct af_alg_tsgl *sgl; 818 struct af_alg_control con = {}; 819 long copied = 0; 820 bool enc = false; 821 bool init = false; 822 int err = 0; 823 824 if (msg->msg_controllen) { 825 err = af_alg_cmsg_send(msg, &con); 826 if (err) 827 return err; 828 829 init = true; 830 switch (con.op) { 831 case ALG_OP_ENCRYPT: 832 enc = true; 833 break; 834 case ALG_OP_DECRYPT: 835 enc = false; 836 break; 837 default: 838 return -EINVAL; 839 } 840 841 if (con.iv && con.iv->ivlen != ivsize) 842 return -EINVAL; 843 } 844 845 lock_sock(sk); 846 if (!ctx->more && ctx->used) { 847 err = -EINVAL; 848 goto unlock; 849 } 850 851 if (init) { 852 ctx->enc = enc; 853 if (con.iv) 854 memcpy(ctx->iv, con.iv->iv, ivsize); 855 856 ctx->aead_assoclen = con.aead_assoclen; 857 } 858 859 while (size) { 860 struct scatterlist *sg; 861 size_t len = size; 862 size_t plen; 863 864 /* use the existing memory in an allocated page */ 865 if (ctx->merge) { 866 sgl = list_entry(ctx->tsgl_list.prev, 867 struct af_alg_tsgl, list); 868 sg = sgl->sg + sgl->cur - 1; 869 len = min_t(size_t, len, 870 PAGE_SIZE - sg->offset - sg->length); 871 872 err = memcpy_from_msg(page_address(sg_page(sg)) + 873 sg->offset + sg->length, 874 msg, len); 875 if (err) 876 goto unlock; 877 878 sg->length += len; 879 ctx->merge = (sg->offset + sg->length) & 880 (PAGE_SIZE - 1); 881 882 ctx->used += len; 883 copied += len; 884 size -= len; 885 continue; 886 } 887 888 if (!af_alg_writable(sk)) { 889 err = af_alg_wait_for_wmem(sk, msg->msg_flags); 890 if (err) 891 goto unlock; 892 } 893 894 /* allocate a new page */ 895 len = min_t(unsigned long, len, af_alg_sndbuf(sk)); 896 897 err = af_alg_alloc_tsgl(sk); 898 if (err) 899 goto unlock; 900 901 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, 902 list); 903 sg = sgl->sg; 904 if (sgl->cur) 905 sg_unmark_end(sg + sgl->cur - 1); 906 907 do { 908 unsigned int i = sgl->cur; 909 910 plen = min_t(size_t, len, PAGE_SIZE); 911 912 sg_assign_page(sg + i, alloc_page(GFP_KERNEL)); 913 if (!sg_page(sg + i)) { 914 err = -ENOMEM; 915 goto unlock; 916 } 917 918 err = memcpy_from_msg(page_address(sg_page(sg + i)), 919 msg, plen); 920 if (err) { 921 __free_page(sg_page(sg + i)); 922 sg_assign_page(sg + i, NULL); 923 goto unlock; 924 } 925 926 sg[i].length = plen; 927 len -= plen; 928 ctx->used += plen; 929 copied += plen; 930 size -= plen; 931 sgl->cur++; 932 } while (len && sgl->cur < MAX_SGL_ENTS); 933 934 if (!size) 935 sg_mark_end(sg + sgl->cur - 1); 936 937 ctx->merge = plen & (PAGE_SIZE - 1); 938 } 939 940 err = 0; 941 942 ctx->more = msg->msg_flags & MSG_MORE; 943 944 unlock: 945 af_alg_data_wakeup(sk); 946 release_sock(sk); 947 948 return copied ?: err; 949 } 950 EXPORT_SYMBOL_GPL(af_alg_sendmsg); 951 952 /** 953 * af_alg_sendpage - sendpage system call handler 954 * 955 * This is a generic implementation of sendpage to fill ctx->tsgl_list. 956 */ 957 ssize_t af_alg_sendpage(struct socket *sock, struct page *page, 958 int offset, size_t size, int flags) 959 { 960 struct sock *sk = sock->sk; 961 struct alg_sock *ask = alg_sk(sk); 962 struct af_alg_ctx *ctx = ask->private; 963 struct af_alg_tsgl *sgl; 964 int err = -EINVAL; 965 966 if (flags & MSG_SENDPAGE_NOTLAST) 967 flags |= MSG_MORE; 968 969 lock_sock(sk); 970 if (!ctx->more && ctx->used) 971 goto unlock; 972 973 if (!size) 974 goto done; 975 976 if (!af_alg_writable(sk)) { 977 err = af_alg_wait_for_wmem(sk, flags); 978 if (err) 979 goto unlock; 980 } 981 982 err = af_alg_alloc_tsgl(sk); 983 if (err) 984 goto unlock; 985 986 ctx->merge = 0; 987 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list); 988 989 if (sgl->cur) 990 sg_unmark_end(sgl->sg + sgl->cur - 1); 991 992 sg_mark_end(sgl->sg + sgl->cur); 993 994 get_page(page); 995 sg_set_page(sgl->sg + sgl->cur, page, size, offset); 996 sgl->cur++; 997 ctx->used += size; 998 999 done: 1000 ctx->more = flags & MSG_MORE; 1001 1002 unlock: 1003 af_alg_data_wakeup(sk); 1004 release_sock(sk); 1005 1006 return err ?: size; 1007 } 1008 EXPORT_SYMBOL_GPL(af_alg_sendpage); 1009 1010 /** 1011 * af_alg_free_resources - release resources required for crypto request 1012 */ 1013 void af_alg_free_resources(struct af_alg_async_req *areq) 1014 { 1015 struct sock *sk = areq->sk; 1016 1017 af_alg_free_areq_sgls(areq); 1018 sock_kfree_s(sk, areq, areq->areqlen); 1019 } 1020 EXPORT_SYMBOL_GPL(af_alg_free_resources); 1021 1022 /** 1023 * af_alg_async_cb - AIO callback handler 1024 * 1025 * This handler cleans up the struct af_alg_async_req upon completion of the 1026 * AIO operation. 1027 * 1028 * The number of bytes to be generated with the AIO operation must be set 1029 * in areq->outlen before the AIO callback handler is invoked. 1030 */ 1031 void af_alg_async_cb(struct crypto_async_request *_req, int err) 1032 { 1033 struct af_alg_async_req *areq = _req->data; 1034 struct sock *sk = areq->sk; 1035 struct kiocb *iocb = areq->iocb; 1036 unsigned int resultlen; 1037 1038 /* Buffer size written by crypto operation. */ 1039 resultlen = areq->outlen; 1040 1041 af_alg_free_resources(areq); 1042 sock_put(sk); 1043 1044 iocb->ki_complete(iocb, err ? err : (int)resultlen, 0); 1045 } 1046 EXPORT_SYMBOL_GPL(af_alg_async_cb); 1047 1048 /** 1049 * af_alg_poll - poll system call handler 1050 */ 1051 __poll_t af_alg_poll(struct file *file, struct socket *sock, 1052 poll_table *wait) 1053 { 1054 struct sock *sk = sock->sk; 1055 struct alg_sock *ask = alg_sk(sk); 1056 struct af_alg_ctx *ctx = ask->private; 1057 __poll_t mask; 1058 1059 sock_poll_wait(file, sock, wait); 1060 mask = 0; 1061 1062 if (!ctx->more || ctx->used) 1063 mask |= EPOLLIN | EPOLLRDNORM; 1064 1065 if (af_alg_writable(sk)) 1066 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND; 1067 1068 return mask; 1069 } 1070 EXPORT_SYMBOL_GPL(af_alg_poll); 1071 1072 /** 1073 * af_alg_alloc_areq - allocate struct af_alg_async_req 1074 * 1075 * @sk socket of connection to user space 1076 * @areqlen size of struct af_alg_async_req + crypto_*_reqsize 1077 * @return allocated data structure or ERR_PTR upon error 1078 */ 1079 struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk, 1080 unsigned int areqlen) 1081 { 1082 struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL); 1083 1084 if (unlikely(!areq)) 1085 return ERR_PTR(-ENOMEM); 1086 1087 areq->areqlen = areqlen; 1088 areq->sk = sk; 1089 areq->last_rsgl = NULL; 1090 INIT_LIST_HEAD(&areq->rsgl_list); 1091 areq->tsgl = NULL; 1092 areq->tsgl_entries = 0; 1093 1094 return areq; 1095 } 1096 EXPORT_SYMBOL_GPL(af_alg_alloc_areq); 1097 1098 /** 1099 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto 1100 * operation 1101 * 1102 * @sk socket of connection to user space 1103 * @msg user space message 1104 * @flags flags used to invoke recvmsg with 1105 * @areq instance of the cryptographic request that will hold the RX SGL 1106 * @maxsize maximum number of bytes to be pulled from user space 1107 * @outlen number of bytes in the RX SGL 1108 * @return 0 on success, < 0 upon error 1109 */ 1110 int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags, 1111 struct af_alg_async_req *areq, size_t maxsize, 1112 size_t *outlen) 1113 { 1114 struct alg_sock *ask = alg_sk(sk); 1115 struct af_alg_ctx *ctx = ask->private; 1116 size_t len = 0; 1117 1118 while (maxsize > len && msg_data_left(msg)) { 1119 struct af_alg_rsgl *rsgl; 1120 size_t seglen; 1121 int err; 1122 1123 /* limit the amount of readable buffers */ 1124 if (!af_alg_readable(sk)) 1125 break; 1126 1127 seglen = min_t(size_t, (maxsize - len), 1128 msg_data_left(msg)); 1129 1130 if (list_empty(&areq->rsgl_list)) { 1131 rsgl = &areq->first_rsgl; 1132 } else { 1133 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL); 1134 if (unlikely(!rsgl)) 1135 return -ENOMEM; 1136 } 1137 1138 rsgl->sgl.npages = 0; 1139 list_add_tail(&rsgl->list, &areq->rsgl_list); 1140 1141 /* make one iovec available as scatterlist */ 1142 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen); 1143 if (err < 0) { 1144 rsgl->sg_num_bytes = 0; 1145 return err; 1146 } 1147 1148 /* chain the new scatterlist with previous one */ 1149 if (areq->last_rsgl) 1150 af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl); 1151 1152 areq->last_rsgl = rsgl; 1153 len += err; 1154 atomic_add(err, &ctx->rcvused); 1155 rsgl->sg_num_bytes = err; 1156 iov_iter_advance(&msg->msg_iter, err); 1157 } 1158 1159 *outlen = len; 1160 return 0; 1161 } 1162 EXPORT_SYMBOL_GPL(af_alg_get_rsgl); 1163 1164 static int __init af_alg_init(void) 1165 { 1166 int err = proto_register(&alg_proto, 0); 1167 1168 if (err) 1169 goto out; 1170 1171 err = sock_register(&alg_family); 1172 if (err != 0) 1173 goto out_unregister_proto; 1174 1175 out: 1176 return err; 1177 1178 out_unregister_proto: 1179 proto_unregister(&alg_proto); 1180 goto out; 1181 } 1182 1183 static void __exit af_alg_exit(void) 1184 { 1185 sock_unregister(PF_ALG); 1186 proto_unregister(&alg_proto); 1187 } 1188 1189 module_init(af_alg_init); 1190 module_exit(af_alg_exit); 1191 MODULE_LICENSE("GPL"); 1192 MODULE_ALIAS_NETPROTO(AF_ALG); 1193