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 ctx->init = ctx->more; 639 } 640 EXPORT_SYMBOL_GPL(af_alg_pull_tsgl); 641 642 /** 643 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request 644 * 645 * @areq Request holding the TX and RX SGL 646 */ 647 static void af_alg_free_areq_sgls(struct af_alg_async_req *areq) 648 { 649 struct sock *sk = areq->sk; 650 struct alg_sock *ask = alg_sk(sk); 651 struct af_alg_ctx *ctx = ask->private; 652 struct af_alg_rsgl *rsgl, *tmp; 653 struct scatterlist *tsgl; 654 struct scatterlist *sg; 655 unsigned int i; 656 657 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) { 658 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused); 659 af_alg_free_sg(&rsgl->sgl); 660 list_del(&rsgl->list); 661 if (rsgl != &areq->first_rsgl) 662 sock_kfree_s(sk, rsgl, sizeof(*rsgl)); 663 } 664 665 tsgl = areq->tsgl; 666 if (tsgl) { 667 for_each_sg(tsgl, sg, areq->tsgl_entries, i) { 668 if (!sg_page(sg)) 669 continue; 670 put_page(sg_page(sg)); 671 } 672 673 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl)); 674 } 675 } 676 677 /** 678 * af_alg_wait_for_wmem - wait for availability of writable memory 679 * 680 * @sk socket of connection to user space 681 * @flags If MSG_DONTWAIT is set, then only report if function would sleep 682 * @return 0 when writable memory is available, < 0 upon error 683 */ 684 static int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags) 685 { 686 DEFINE_WAIT_FUNC(wait, woken_wake_function); 687 int err = -ERESTARTSYS; 688 long timeout; 689 690 if (flags & MSG_DONTWAIT) 691 return -EAGAIN; 692 693 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk); 694 695 add_wait_queue(sk_sleep(sk), &wait); 696 for (;;) { 697 if (signal_pending(current)) 698 break; 699 timeout = MAX_SCHEDULE_TIMEOUT; 700 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) { 701 err = 0; 702 break; 703 } 704 } 705 remove_wait_queue(sk_sleep(sk), &wait); 706 707 return err; 708 } 709 710 /** 711 * af_alg_wmem_wakeup - wakeup caller when writable memory is available 712 * 713 * @sk socket of connection to user space 714 */ 715 void af_alg_wmem_wakeup(struct sock *sk) 716 { 717 struct socket_wq *wq; 718 719 if (!af_alg_writable(sk)) 720 return; 721 722 rcu_read_lock(); 723 wq = rcu_dereference(sk->sk_wq); 724 if (skwq_has_sleeper(wq)) 725 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | 726 EPOLLRDNORM | 727 EPOLLRDBAND); 728 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN); 729 rcu_read_unlock(); 730 } 731 EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup); 732 733 /** 734 * af_alg_wait_for_data - wait for availability of TX data 735 * 736 * @sk socket of connection to user space 737 * @flags If MSG_DONTWAIT is set, then only report if function would sleep 738 * @min Set to minimum request size if partial requests are allowed. 739 * @return 0 when writable memory is available, < 0 upon error 740 */ 741 int af_alg_wait_for_data(struct sock *sk, unsigned flags, unsigned min) 742 { 743 DEFINE_WAIT_FUNC(wait, woken_wake_function); 744 struct alg_sock *ask = alg_sk(sk); 745 struct af_alg_ctx *ctx = ask->private; 746 long timeout; 747 int err = -ERESTARTSYS; 748 749 if (flags & MSG_DONTWAIT) 750 return -EAGAIN; 751 752 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk); 753 754 add_wait_queue(sk_sleep(sk), &wait); 755 for (;;) { 756 if (signal_pending(current)) 757 break; 758 timeout = MAX_SCHEDULE_TIMEOUT; 759 if (sk_wait_event(sk, &timeout, 760 ctx->init && (!ctx->more || 761 (min && ctx->used >= min)), 762 &wait)) { 763 err = 0; 764 break; 765 } 766 } 767 remove_wait_queue(sk_sleep(sk), &wait); 768 769 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk); 770 771 return err; 772 } 773 EXPORT_SYMBOL_GPL(af_alg_wait_for_data); 774 775 /** 776 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel 777 * 778 * @sk socket of connection to user space 779 */ 780 static void af_alg_data_wakeup(struct sock *sk) 781 { 782 struct alg_sock *ask = alg_sk(sk); 783 struct af_alg_ctx *ctx = ask->private; 784 struct socket_wq *wq; 785 786 if (!ctx->used) 787 return; 788 789 rcu_read_lock(); 790 wq = rcu_dereference(sk->sk_wq); 791 if (skwq_has_sleeper(wq)) 792 wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT | 793 EPOLLRDNORM | 794 EPOLLRDBAND); 795 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); 796 rcu_read_unlock(); 797 } 798 799 /** 800 * af_alg_sendmsg - implementation of sendmsg system call handler 801 * 802 * The sendmsg system call handler obtains the user data and stores it 803 * in ctx->tsgl_list. This implies allocation of the required numbers of 804 * struct af_alg_tsgl. 805 * 806 * In addition, the ctx is filled with the information sent via CMSG. 807 * 808 * @sock socket of connection to user space 809 * @msg message from user space 810 * @size size of message from user space 811 * @ivsize the size of the IV for the cipher operation to verify that the 812 * user-space-provided IV has the right size 813 * @return the number of copied data upon success, < 0 upon error 814 */ 815 int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size, 816 unsigned int ivsize) 817 { 818 struct sock *sk = sock->sk; 819 struct alg_sock *ask = alg_sk(sk); 820 struct af_alg_ctx *ctx = ask->private; 821 struct af_alg_tsgl *sgl; 822 struct af_alg_control con = {}; 823 long copied = 0; 824 bool enc = false; 825 bool init = false; 826 int err = 0; 827 828 if (msg->msg_controllen) { 829 err = af_alg_cmsg_send(msg, &con); 830 if (err) 831 return err; 832 833 init = true; 834 switch (con.op) { 835 case ALG_OP_ENCRYPT: 836 enc = true; 837 break; 838 case ALG_OP_DECRYPT: 839 enc = false; 840 break; 841 default: 842 return -EINVAL; 843 } 844 845 if (con.iv && con.iv->ivlen != ivsize) 846 return -EINVAL; 847 } 848 849 lock_sock(sk); 850 if (ctx->init && (init || !ctx->more)) { 851 err = -EINVAL; 852 goto unlock; 853 } 854 ctx->init = true; 855 856 if (init) { 857 ctx->enc = enc; 858 if (con.iv) 859 memcpy(ctx->iv, con.iv->iv, ivsize); 860 861 ctx->aead_assoclen = con.aead_assoclen; 862 } 863 864 while (size) { 865 struct scatterlist *sg; 866 size_t len = size; 867 size_t plen; 868 869 /* use the existing memory in an allocated page */ 870 if (ctx->merge) { 871 sgl = list_entry(ctx->tsgl_list.prev, 872 struct af_alg_tsgl, list); 873 sg = sgl->sg + sgl->cur - 1; 874 len = min_t(size_t, len, 875 PAGE_SIZE - sg->offset - sg->length); 876 877 err = memcpy_from_msg(page_address(sg_page(sg)) + 878 sg->offset + sg->length, 879 msg, len); 880 if (err) 881 goto unlock; 882 883 sg->length += len; 884 ctx->merge = (sg->offset + sg->length) & 885 (PAGE_SIZE - 1); 886 887 ctx->used += len; 888 copied += len; 889 size -= len; 890 continue; 891 } 892 893 if (!af_alg_writable(sk)) { 894 err = af_alg_wait_for_wmem(sk, msg->msg_flags); 895 if (err) 896 goto unlock; 897 } 898 899 /* allocate a new page */ 900 len = min_t(unsigned long, len, af_alg_sndbuf(sk)); 901 902 err = af_alg_alloc_tsgl(sk); 903 if (err) 904 goto unlock; 905 906 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, 907 list); 908 sg = sgl->sg; 909 if (sgl->cur) 910 sg_unmark_end(sg + sgl->cur - 1); 911 912 do { 913 unsigned int i = sgl->cur; 914 915 plen = min_t(size_t, len, PAGE_SIZE); 916 917 sg_assign_page(sg + i, alloc_page(GFP_KERNEL)); 918 if (!sg_page(sg + i)) { 919 err = -ENOMEM; 920 goto unlock; 921 } 922 923 err = memcpy_from_msg(page_address(sg_page(sg + i)), 924 msg, plen); 925 if (err) { 926 __free_page(sg_page(sg + i)); 927 sg_assign_page(sg + i, NULL); 928 goto unlock; 929 } 930 931 sg[i].length = plen; 932 len -= plen; 933 ctx->used += plen; 934 copied += plen; 935 size -= plen; 936 sgl->cur++; 937 } while (len && sgl->cur < MAX_SGL_ENTS); 938 939 if (!size) 940 sg_mark_end(sg + sgl->cur - 1); 941 942 ctx->merge = plen & (PAGE_SIZE - 1); 943 } 944 945 err = 0; 946 947 ctx->more = msg->msg_flags & MSG_MORE; 948 949 unlock: 950 af_alg_data_wakeup(sk); 951 release_sock(sk); 952 953 return copied ?: err; 954 } 955 EXPORT_SYMBOL_GPL(af_alg_sendmsg); 956 957 /** 958 * af_alg_sendpage - sendpage system call handler 959 * 960 * This is a generic implementation of sendpage to fill ctx->tsgl_list. 961 */ 962 ssize_t af_alg_sendpage(struct socket *sock, struct page *page, 963 int offset, size_t size, int flags) 964 { 965 struct sock *sk = sock->sk; 966 struct alg_sock *ask = alg_sk(sk); 967 struct af_alg_ctx *ctx = ask->private; 968 struct af_alg_tsgl *sgl; 969 int err = -EINVAL; 970 971 if (flags & MSG_SENDPAGE_NOTLAST) 972 flags |= MSG_MORE; 973 974 lock_sock(sk); 975 if (!ctx->more && ctx->used) 976 goto unlock; 977 978 if (!size) 979 goto done; 980 981 if (!af_alg_writable(sk)) { 982 err = af_alg_wait_for_wmem(sk, flags); 983 if (err) 984 goto unlock; 985 } 986 987 err = af_alg_alloc_tsgl(sk); 988 if (err) 989 goto unlock; 990 991 ctx->merge = 0; 992 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list); 993 994 if (sgl->cur) 995 sg_unmark_end(sgl->sg + sgl->cur - 1); 996 997 sg_mark_end(sgl->sg + sgl->cur); 998 999 get_page(page); 1000 sg_set_page(sgl->sg + sgl->cur, page, size, offset); 1001 sgl->cur++; 1002 ctx->used += size; 1003 1004 done: 1005 ctx->more = flags & MSG_MORE; 1006 1007 unlock: 1008 af_alg_data_wakeup(sk); 1009 release_sock(sk); 1010 1011 return err ?: size; 1012 } 1013 EXPORT_SYMBOL_GPL(af_alg_sendpage); 1014 1015 /** 1016 * af_alg_free_resources - release resources required for crypto request 1017 */ 1018 void af_alg_free_resources(struct af_alg_async_req *areq) 1019 { 1020 struct sock *sk = areq->sk; 1021 1022 af_alg_free_areq_sgls(areq); 1023 sock_kfree_s(sk, areq, areq->areqlen); 1024 } 1025 EXPORT_SYMBOL_GPL(af_alg_free_resources); 1026 1027 /** 1028 * af_alg_async_cb - AIO callback handler 1029 * 1030 * This handler cleans up the struct af_alg_async_req upon completion of the 1031 * AIO operation. 1032 * 1033 * The number of bytes to be generated with the AIO operation must be set 1034 * in areq->outlen before the AIO callback handler is invoked. 1035 */ 1036 void af_alg_async_cb(struct crypto_async_request *_req, int err) 1037 { 1038 struct af_alg_async_req *areq = _req->data; 1039 struct sock *sk = areq->sk; 1040 struct kiocb *iocb = areq->iocb; 1041 unsigned int resultlen; 1042 1043 /* Buffer size written by crypto operation. */ 1044 resultlen = areq->outlen; 1045 1046 af_alg_free_resources(areq); 1047 sock_put(sk); 1048 1049 iocb->ki_complete(iocb, err ? err : (int)resultlen, 0); 1050 } 1051 EXPORT_SYMBOL_GPL(af_alg_async_cb); 1052 1053 /** 1054 * af_alg_poll - poll system call handler 1055 */ 1056 __poll_t af_alg_poll(struct file *file, struct socket *sock, 1057 poll_table *wait) 1058 { 1059 struct sock *sk = sock->sk; 1060 struct alg_sock *ask = alg_sk(sk); 1061 struct af_alg_ctx *ctx = ask->private; 1062 __poll_t mask; 1063 1064 sock_poll_wait(file, sock, wait); 1065 mask = 0; 1066 1067 if (!ctx->more || ctx->used) 1068 mask |= EPOLLIN | EPOLLRDNORM; 1069 1070 if (af_alg_writable(sk)) 1071 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND; 1072 1073 return mask; 1074 } 1075 EXPORT_SYMBOL_GPL(af_alg_poll); 1076 1077 /** 1078 * af_alg_alloc_areq - allocate struct af_alg_async_req 1079 * 1080 * @sk socket of connection to user space 1081 * @areqlen size of struct af_alg_async_req + crypto_*_reqsize 1082 * @return allocated data structure or ERR_PTR upon error 1083 */ 1084 struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk, 1085 unsigned int areqlen) 1086 { 1087 struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL); 1088 1089 if (unlikely(!areq)) 1090 return ERR_PTR(-ENOMEM); 1091 1092 areq->areqlen = areqlen; 1093 areq->sk = sk; 1094 areq->last_rsgl = NULL; 1095 INIT_LIST_HEAD(&areq->rsgl_list); 1096 areq->tsgl = NULL; 1097 areq->tsgl_entries = 0; 1098 1099 return areq; 1100 } 1101 EXPORT_SYMBOL_GPL(af_alg_alloc_areq); 1102 1103 /** 1104 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto 1105 * operation 1106 * 1107 * @sk socket of connection to user space 1108 * @msg user space message 1109 * @flags flags used to invoke recvmsg with 1110 * @areq instance of the cryptographic request that will hold the RX SGL 1111 * @maxsize maximum number of bytes to be pulled from user space 1112 * @outlen number of bytes in the RX SGL 1113 * @return 0 on success, < 0 upon error 1114 */ 1115 int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags, 1116 struct af_alg_async_req *areq, size_t maxsize, 1117 size_t *outlen) 1118 { 1119 struct alg_sock *ask = alg_sk(sk); 1120 struct af_alg_ctx *ctx = ask->private; 1121 size_t len = 0; 1122 1123 while (maxsize > len && msg_data_left(msg)) { 1124 struct af_alg_rsgl *rsgl; 1125 size_t seglen; 1126 int err; 1127 1128 /* limit the amount of readable buffers */ 1129 if (!af_alg_readable(sk)) 1130 break; 1131 1132 seglen = min_t(size_t, (maxsize - len), 1133 msg_data_left(msg)); 1134 1135 if (list_empty(&areq->rsgl_list)) { 1136 rsgl = &areq->first_rsgl; 1137 } else { 1138 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL); 1139 if (unlikely(!rsgl)) 1140 return -ENOMEM; 1141 } 1142 1143 rsgl->sgl.npages = 0; 1144 list_add_tail(&rsgl->list, &areq->rsgl_list); 1145 1146 /* make one iovec available as scatterlist */ 1147 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen); 1148 if (err < 0) { 1149 rsgl->sg_num_bytes = 0; 1150 return err; 1151 } 1152 1153 /* chain the new scatterlist with previous one */ 1154 if (areq->last_rsgl) 1155 af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl); 1156 1157 areq->last_rsgl = rsgl; 1158 len += err; 1159 atomic_add(err, &ctx->rcvused); 1160 rsgl->sg_num_bytes = err; 1161 iov_iter_advance(&msg->msg_iter, err); 1162 } 1163 1164 *outlen = len; 1165 return 0; 1166 } 1167 EXPORT_SYMBOL_GPL(af_alg_get_rsgl); 1168 1169 static int __init af_alg_init(void) 1170 { 1171 int err = proto_register(&alg_proto, 0); 1172 1173 if (err) 1174 goto out; 1175 1176 err = sock_register(&alg_family); 1177 if (err != 0) 1178 goto out_unregister_proto; 1179 1180 out: 1181 return err; 1182 1183 out_unregister_proto: 1184 proto_unregister(&alg_proto); 1185 goto out; 1186 } 1187 1188 static void __exit af_alg_exit(void) 1189 { 1190 sock_unregister(PF_ALG); 1191 proto_unregister(&alg_proto); 1192 } 1193 1194 module_init(af_alg_init); 1195 module_exit(af_alg_exit); 1196 MODULE_LICENSE("GPL"); 1197 MODULE_ALIAS_NETPROTO(AF_ALG); 1198