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crypto: ccp - no need to check return value of debugfs_create functions
[thirdparty/kernel/stable.git] / crypto / af_alg.c
1 /*
2 * af_alg: User-space algorithm interface
3 *
4 * This file provides the user-space API for algorithms.
5 *
6 * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the Free
10 * Software Foundation; either version 2 of the License, or (at your option)
11 * any later version.
12 *
13 */
14
15 #include <linux/atomic.h>
16 #include <crypto/if_alg.h>
17 #include <linux/crypto.h>
18 #include <linux/init.h>
19 #include <linux/kernel.h>
20 #include <linux/list.h>
21 #include <linux/module.h>
22 #include <linux/net.h>
23 #include <linux/rwsem.h>
24 #include <linux/sched/signal.h>
25 #include <linux/security.h>
26
27 struct alg_type_list {
28 const struct af_alg_type *type;
29 struct list_head list;
30 };
31
32 static atomic_long_t alg_memory_allocated;
33
34 static struct proto alg_proto = {
35 .name = "ALG",
36 .owner = THIS_MODULE,
37 .memory_allocated = &alg_memory_allocated,
38 .obj_size = sizeof(struct alg_sock),
39 };
40
41 static LIST_HEAD(alg_types);
42 static DECLARE_RWSEM(alg_types_sem);
43
44 static const struct af_alg_type *alg_get_type(const char *name)
45 {
46 const struct af_alg_type *type = ERR_PTR(-ENOENT);
47 struct alg_type_list *node;
48
49 down_read(&alg_types_sem);
50 list_for_each_entry(node, &alg_types, list) {
51 if (strcmp(node->type->name, name))
52 continue;
53
54 if (try_module_get(node->type->owner))
55 type = node->type;
56 break;
57 }
58 up_read(&alg_types_sem);
59
60 return type;
61 }
62
63 int af_alg_register_type(const struct af_alg_type *type)
64 {
65 struct alg_type_list *node;
66 int err = -EEXIST;
67
68 down_write(&alg_types_sem);
69 list_for_each_entry(node, &alg_types, list) {
70 if (!strcmp(node->type->name, type->name))
71 goto unlock;
72 }
73
74 node = kmalloc(sizeof(*node), GFP_KERNEL);
75 err = -ENOMEM;
76 if (!node)
77 goto unlock;
78
79 type->ops->owner = THIS_MODULE;
80 if (type->ops_nokey)
81 type->ops_nokey->owner = THIS_MODULE;
82 node->type = type;
83 list_add(&node->list, &alg_types);
84 err = 0;
85
86 unlock:
87 up_write(&alg_types_sem);
88
89 return err;
90 }
91 EXPORT_SYMBOL_GPL(af_alg_register_type);
92
93 int af_alg_unregister_type(const struct af_alg_type *type)
94 {
95 struct alg_type_list *node;
96 int err = -ENOENT;
97
98 down_write(&alg_types_sem);
99 list_for_each_entry(node, &alg_types, list) {
100 if (strcmp(node->type->name, type->name))
101 continue;
102
103 list_del(&node->list);
104 kfree(node);
105 err = 0;
106 break;
107 }
108 up_write(&alg_types_sem);
109
110 return err;
111 }
112 EXPORT_SYMBOL_GPL(af_alg_unregister_type);
113
114 static void alg_do_release(const struct af_alg_type *type, void *private)
115 {
116 if (!type)
117 return;
118
119 type->release(private);
120 module_put(type->owner);
121 }
122
123 int af_alg_release(struct socket *sock)
124 {
125 if (sock->sk)
126 sock_put(sock->sk);
127 return 0;
128 }
129 EXPORT_SYMBOL_GPL(af_alg_release);
130
131 void af_alg_release_parent(struct sock *sk)
132 {
133 struct alg_sock *ask = alg_sk(sk);
134 unsigned int nokey = ask->nokey_refcnt;
135 bool last = nokey && !ask->refcnt;
136
137 sk = ask->parent;
138 ask = alg_sk(sk);
139
140 lock_sock(sk);
141 ask->nokey_refcnt -= nokey;
142 if (!last)
143 last = !--ask->refcnt;
144 release_sock(sk);
145
146 if (last)
147 sock_put(sk);
148 }
149 EXPORT_SYMBOL_GPL(af_alg_release_parent);
150
151 static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
152 {
153 const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY;
154 struct sock *sk = sock->sk;
155 struct alg_sock *ask = alg_sk(sk);
156 struct sockaddr_alg *sa = (void *)uaddr;
157 const struct af_alg_type *type;
158 void *private;
159 int err;
160
161 if (sock->state == SS_CONNECTED)
162 return -EINVAL;
163
164 if (addr_len < sizeof(*sa))
165 return -EINVAL;
166
167 /* If caller uses non-allowed flag, return error. */
168 if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed))
169 return -EINVAL;
170
171 sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
172 sa->salg_name[sizeof(sa->salg_name) + addr_len - sizeof(*sa) - 1] = 0;
173
174 type = alg_get_type(sa->salg_type);
175 if (IS_ERR(type) && PTR_ERR(type) == -ENOENT) {
176 request_module("algif-%s", sa->salg_type);
177 type = alg_get_type(sa->salg_type);
178 }
179
180 if (IS_ERR(type))
181 return PTR_ERR(type);
182
183 private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask);
184 if (IS_ERR(private)) {
185 module_put(type->owner);
186 return PTR_ERR(private);
187 }
188
189 err = -EBUSY;
190 lock_sock(sk);
191 if (ask->refcnt | ask->nokey_refcnt)
192 goto unlock;
193
194 swap(ask->type, type);
195 swap(ask->private, private);
196
197 err = 0;
198
199 unlock:
200 release_sock(sk);
201
202 alg_do_release(type, private);
203
204 return err;
205 }
206
207 static int alg_setkey(struct sock *sk, char __user *ukey,
208 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_user(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 static int alg_setsockopt(struct socket *sock, int level, int optname,
232 char __user *optval, unsigned int optlen)
233 {
234 struct sock *sk = sock->sk;
235 struct alg_sock *ask = alg_sk(sk);
236 const struct af_alg_type *type;
237 int err = -EBUSY;
238
239 lock_sock(sk);
240 if (ask->refcnt)
241 goto unlock;
242
243 type = ask->type;
244
245 err = -ENOPROTOOPT;
246 if (level != SOL_ALG || !type)
247 goto unlock;
248
249 switch (optname) {
250 case ALG_SET_KEY:
251 if (sock->state == SS_CONNECTED)
252 goto unlock;
253 if (!type->setkey)
254 goto unlock;
255
256 err = alg_setkey(sk, optval, optlen);
257 break;
258 case ALG_SET_AEAD_AUTHSIZE:
259 if (sock->state == SS_CONNECTED)
260 goto unlock;
261 if (!type->setauthsize)
262 goto unlock;
263 err = type->setauthsize(ask->private, optlen);
264 }
265
266 unlock:
267 release_sock(sk);
268
269 return err;
270 }
271
272 int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern)
273 {
274 struct alg_sock *ask = alg_sk(sk);
275 const struct af_alg_type *type;
276 struct sock *sk2;
277 unsigned int nokey;
278 int err;
279
280 lock_sock(sk);
281 type = ask->type;
282
283 err = -EINVAL;
284 if (!type)
285 goto unlock;
286
287 sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, kern);
288 err = -ENOMEM;
289 if (!sk2)
290 goto unlock;
291
292 sock_init_data(newsock, sk2);
293 security_sock_graft(sk2, newsock);
294 security_sk_clone(sk, sk2);
295
296 err = type->accept(ask->private, sk2);
297
298 nokey = err == -ENOKEY;
299 if (nokey && type->accept_nokey)
300 err = type->accept_nokey(ask->private, sk2);
301
302 if (err)
303 goto unlock;
304
305 if (nokey || !ask->refcnt++)
306 sock_hold(sk);
307 ask->nokey_refcnt += nokey;
308 alg_sk(sk2)->parent = sk;
309 alg_sk(sk2)->type = type;
310 alg_sk(sk2)->nokey_refcnt = nokey;
311
312 newsock->ops = type->ops;
313 newsock->state = SS_CONNECTED;
314
315 if (nokey)
316 newsock->ops = type->ops_nokey;
317
318 err = 0;
319
320 unlock:
321 release_sock(sk);
322
323 return err;
324 }
325 EXPORT_SYMBOL_GPL(af_alg_accept);
326
327 static int alg_accept(struct socket *sock, struct socket *newsock, int flags,
328 bool kern)
329 {
330 return af_alg_accept(sock->sk, newsock, kern);
331 }
332
333 static const struct proto_ops alg_proto_ops = {
334 .family = PF_ALG,
335 .owner = THIS_MODULE,
336
337 .connect = sock_no_connect,
338 .socketpair = sock_no_socketpair,
339 .getname = sock_no_getname,
340 .ioctl = sock_no_ioctl,
341 .listen = sock_no_listen,
342 .shutdown = sock_no_shutdown,
343 .getsockopt = sock_no_getsockopt,
344 .mmap = sock_no_mmap,
345 .sendpage = sock_no_sendpage,
346 .sendmsg = sock_no_sendmsg,
347 .recvmsg = sock_no_recvmsg,
348
349 .bind = alg_bind,
350 .release = af_alg_release,
351 .setsockopt = alg_setsockopt,
352 .accept = alg_accept,
353 };
354
355 static void alg_sock_destruct(struct sock *sk)
356 {
357 struct alg_sock *ask = alg_sk(sk);
358
359 alg_do_release(ask->type, ask->private);
360 }
361
362 static int alg_create(struct net *net, struct socket *sock, int protocol,
363 int kern)
364 {
365 struct sock *sk;
366 int err;
367
368 if (sock->type != SOCK_SEQPACKET)
369 return -ESOCKTNOSUPPORT;
370 if (protocol != 0)
371 return -EPROTONOSUPPORT;
372
373 err = -ENOMEM;
374 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
375 if (!sk)
376 goto out;
377
378 sock->ops = &alg_proto_ops;
379 sock_init_data(sock, sk);
380
381 sk->sk_destruct = alg_sock_destruct;
382
383 return 0;
384 out:
385 return err;
386 }
387
388 static const struct net_proto_family alg_family = {
389 .family = PF_ALG,
390 .create = alg_create,
391 .owner = THIS_MODULE,
392 };
393
394 int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
395 {
396 size_t off;
397 ssize_t n;
398 int npages, i;
399
400 n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
401 if (n < 0)
402 return n;
403
404 npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT;
405 if (WARN_ON(npages == 0))
406 return -EINVAL;
407 /* Add one extra for linking */
408 sg_init_table(sgl->sg, npages + 1);
409
410 for (i = 0, len = n; i < npages; i++) {
411 int plen = min_t(int, len, PAGE_SIZE - off);
412
413 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
414
415 off = 0;
416 len -= plen;
417 }
418 sg_mark_end(sgl->sg + npages - 1);
419 sgl->npages = npages;
420
421 return n;
422 }
423 EXPORT_SYMBOL_GPL(af_alg_make_sg);
424
425 static void af_alg_link_sg(struct af_alg_sgl *sgl_prev,
426 struct af_alg_sgl *sgl_new)
427 {
428 sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
429 sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
430 }
431
432 void af_alg_free_sg(struct af_alg_sgl *sgl)
433 {
434 int i;
435
436 for (i = 0; i < sgl->npages; i++)
437 put_page(sgl->pages[i]);
438 }
439 EXPORT_SYMBOL_GPL(af_alg_free_sg);
440
441 static int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
442 {
443 struct cmsghdr *cmsg;
444
445 for_each_cmsghdr(cmsg, msg) {
446 if (!CMSG_OK(msg, cmsg))
447 return -EINVAL;
448 if (cmsg->cmsg_level != SOL_ALG)
449 continue;
450
451 switch (cmsg->cmsg_type) {
452 case ALG_SET_IV:
453 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
454 return -EINVAL;
455 con->iv = (void *)CMSG_DATA(cmsg);
456 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
457 sizeof(*con->iv)))
458 return -EINVAL;
459 break;
460
461 case ALG_SET_OP:
462 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
463 return -EINVAL;
464 con->op = *(u32 *)CMSG_DATA(cmsg);
465 break;
466
467 case ALG_SET_AEAD_ASSOCLEN:
468 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
469 return -EINVAL;
470 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
471 break;
472
473 default:
474 return -EINVAL;
475 }
476 }
477
478 return 0;
479 }
480
481 /**
482 * af_alg_alloc_tsgl - allocate the TX SGL
483 *
484 * @sk socket of connection to user space
485 * @return: 0 upon success, < 0 upon error
486 */
487 static int af_alg_alloc_tsgl(struct sock *sk)
488 {
489 struct alg_sock *ask = alg_sk(sk);
490 struct af_alg_ctx *ctx = ask->private;
491 struct af_alg_tsgl *sgl;
492 struct scatterlist *sg = NULL;
493
494 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
495 if (!list_empty(&ctx->tsgl_list))
496 sg = sgl->sg;
497
498 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
499 sgl = sock_kmalloc(sk,
500 struct_size(sgl, sg, (MAX_SGL_ENTS + 1)),
501 GFP_KERNEL);
502 if (!sgl)
503 return -ENOMEM;
504
505 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
506 sgl->cur = 0;
507
508 if (sg)
509 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
510
511 list_add_tail(&sgl->list, &ctx->tsgl_list);
512 }
513
514 return 0;
515 }
516
517 /**
518 * aead_count_tsgl - Count number of TX SG entries
519 *
520 * The counting starts from the beginning of the SGL to @bytes. If
521 * an offset is provided, the counting of the SG entries starts at the offset.
522 *
523 * @sk socket of connection to user space
524 * @bytes Count the number of SG entries holding given number of bytes.
525 * @offset Start the counting of SG entries from the given offset.
526 * @return Number of TX SG entries found given the constraints
527 */
528 unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
529 {
530 const struct alg_sock *ask = alg_sk(sk);
531 const struct af_alg_ctx *ctx = ask->private;
532 const struct af_alg_tsgl *sgl;
533 unsigned int i;
534 unsigned int sgl_count = 0;
535
536 if (!bytes)
537 return 0;
538
539 list_for_each_entry(sgl, &ctx->tsgl_list, list) {
540 const struct scatterlist *sg = sgl->sg;
541
542 for (i = 0; i < sgl->cur; i++) {
543 size_t bytes_count;
544
545 /* Skip offset */
546 if (offset >= sg[i].length) {
547 offset -= sg[i].length;
548 bytes -= sg[i].length;
549 continue;
550 }
551
552 bytes_count = sg[i].length - offset;
553
554 offset = 0;
555 sgl_count++;
556
557 /* If we have seen requested number of bytes, stop */
558 if (bytes_count >= bytes)
559 return sgl_count;
560
561 bytes -= bytes_count;
562 }
563 }
564
565 return sgl_count;
566 }
567 EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
568
569 /**
570 * aead_pull_tsgl - Release the specified buffers from TX SGL
571 *
572 * If @dst is non-null, reassign the pages to dst. The caller must release
573 * the pages. If @dst_offset is given only reassign the pages to @dst starting
574 * at the @dst_offset (byte). The caller must ensure that @dst is large
575 * enough (e.g. by using af_alg_count_tsgl with the same offset).
576 *
577 * @sk socket of connection to user space
578 * @used Number of bytes to pull from TX SGL
579 * @dst If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
580 * caller must release the buffers in dst.
581 * @dst_offset Reassign the TX SGL from given offset. All buffers before
582 * reaching the offset is released.
583 */
584 void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
585 size_t dst_offset)
586 {
587 struct alg_sock *ask = alg_sk(sk);
588 struct af_alg_ctx *ctx = ask->private;
589 struct af_alg_tsgl *sgl;
590 struct scatterlist *sg;
591 unsigned int i, j = 0;
592
593 while (!list_empty(&ctx->tsgl_list)) {
594 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
595 list);
596 sg = sgl->sg;
597
598 for (i = 0; i < sgl->cur; i++) {
599 size_t plen = min_t(size_t, used, sg[i].length);
600 struct page *page = sg_page(sg + i);
601
602 if (!page)
603 continue;
604
605 /*
606 * Assumption: caller created af_alg_count_tsgl(len)
607 * SG entries in dst.
608 */
609 if (dst) {
610 if (dst_offset >= plen) {
611 /* discard page before offset */
612 dst_offset -= plen;
613 } else {
614 /* reassign page to dst after offset */
615 get_page(page);
616 sg_set_page(dst + j, page,
617 plen - dst_offset,
618 sg[i].offset + dst_offset);
619 dst_offset = 0;
620 j++;
621 }
622 }
623
624 sg[i].length -= plen;
625 sg[i].offset += plen;
626
627 used -= plen;
628 ctx->used -= plen;
629
630 if (sg[i].length)
631 return;
632
633 put_page(page);
634 sg_assign_page(sg + i, NULL);
635 }
636
637 list_del(&sgl->list);
638 sock_kfree_s(sk, sgl, sizeof(*sgl) + sizeof(sgl->sg[0]) *
639 (MAX_SGL_ENTS + 1));
640 }
641
642 if (!ctx->used)
643 ctx->merge = 0;
644 }
645 EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
646
647 /**
648 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
649 *
650 * @areq Request holding the TX and RX SGL
651 */
652 static void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
653 {
654 struct sock *sk = areq->sk;
655 struct alg_sock *ask = alg_sk(sk);
656 struct af_alg_ctx *ctx = ask->private;
657 struct af_alg_rsgl *rsgl, *tmp;
658 struct scatterlist *tsgl;
659 struct scatterlist *sg;
660 unsigned int i;
661
662 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
663 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
664 af_alg_free_sg(&rsgl->sgl);
665 list_del(&rsgl->list);
666 if (rsgl != &areq->first_rsgl)
667 sock_kfree_s(sk, rsgl, sizeof(*rsgl));
668 }
669
670 tsgl = areq->tsgl;
671 if (tsgl) {
672 for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
673 if (!sg_page(sg))
674 continue;
675 put_page(sg_page(sg));
676 }
677
678 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
679 }
680 }
681
682 /**
683 * af_alg_wait_for_wmem - wait for availability of writable memory
684 *
685 * @sk socket of connection to user space
686 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
687 * @return 0 when writable memory is available, < 0 upon error
688 */
689 static int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
690 {
691 DEFINE_WAIT_FUNC(wait, woken_wake_function);
692 int err = -ERESTARTSYS;
693 long timeout;
694
695 if (flags & MSG_DONTWAIT)
696 return -EAGAIN;
697
698 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
699
700 add_wait_queue(sk_sleep(sk), &wait);
701 for (;;) {
702 if (signal_pending(current))
703 break;
704 timeout = MAX_SCHEDULE_TIMEOUT;
705 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
706 err = 0;
707 break;
708 }
709 }
710 remove_wait_queue(sk_sleep(sk), &wait);
711
712 return err;
713 }
714
715 /**
716 * af_alg_wmem_wakeup - wakeup caller when writable memory is available
717 *
718 * @sk socket of connection to user space
719 */
720 void af_alg_wmem_wakeup(struct sock *sk)
721 {
722 struct socket_wq *wq;
723
724 if (!af_alg_writable(sk))
725 return;
726
727 rcu_read_lock();
728 wq = rcu_dereference(sk->sk_wq);
729 if (skwq_has_sleeper(wq))
730 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN |
731 EPOLLRDNORM |
732 EPOLLRDBAND);
733 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
734 rcu_read_unlock();
735 }
736 EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
737
738 /**
739 * af_alg_wait_for_data - wait for availability of TX data
740 *
741 * @sk socket of connection to user space
742 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
743 * @return 0 when writable memory is available, < 0 upon error
744 */
745 int af_alg_wait_for_data(struct sock *sk, unsigned flags)
746 {
747 DEFINE_WAIT_FUNC(wait, woken_wake_function);
748 struct alg_sock *ask = alg_sk(sk);
749 struct af_alg_ctx *ctx = ask->private;
750 long timeout;
751 int err = -ERESTARTSYS;
752
753 if (flags & MSG_DONTWAIT)
754 return -EAGAIN;
755
756 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
757
758 add_wait_queue(sk_sleep(sk), &wait);
759 for (;;) {
760 if (signal_pending(current))
761 break;
762 timeout = MAX_SCHEDULE_TIMEOUT;
763 if (sk_wait_event(sk, &timeout, (ctx->used || !ctx->more),
764 &wait)) {
765 err = 0;
766 break;
767 }
768 }
769 remove_wait_queue(sk_sleep(sk), &wait);
770
771 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
772
773 return err;
774 }
775 EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
776
777 /**
778 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
779 *
780 * @sk socket of connection to user space
781 */
782 static void af_alg_data_wakeup(struct sock *sk)
783 {
784 struct alg_sock *ask = alg_sk(sk);
785 struct af_alg_ctx *ctx = ask->private;
786 struct socket_wq *wq;
787
788 if (!ctx->used)
789 return;
790
791 rcu_read_lock();
792 wq = rcu_dereference(sk->sk_wq);
793 if (skwq_has_sleeper(wq))
794 wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
795 EPOLLRDNORM |
796 EPOLLRDBAND);
797 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
798 rcu_read_unlock();
799 }
800
801 /**
802 * af_alg_sendmsg - implementation of sendmsg system call handler
803 *
804 * The sendmsg system call handler obtains the user data and stores it
805 * in ctx->tsgl_list. This implies allocation of the required numbers of
806 * struct af_alg_tsgl.
807 *
808 * In addition, the ctx is filled with the information sent via CMSG.
809 *
810 * @sock socket of connection to user space
811 * @msg message from user space
812 * @size size of message from user space
813 * @ivsize the size of the IV for the cipher operation to verify that the
814 * user-space-provided IV has the right size
815 * @return the number of copied data upon success, < 0 upon error
816 */
817 int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
818 unsigned int ivsize)
819 {
820 struct sock *sk = sock->sk;
821 struct alg_sock *ask = alg_sk(sk);
822 struct af_alg_ctx *ctx = ask->private;
823 struct af_alg_tsgl *sgl;
824 struct af_alg_control con = {};
825 long copied = 0;
826 bool enc = 0;
827 bool init = 0;
828 int err = 0;
829
830 if (msg->msg_controllen) {
831 err = af_alg_cmsg_send(msg, &con);
832 if (err)
833 return err;
834
835 init = 1;
836 switch (con.op) {
837 case ALG_OP_ENCRYPT:
838 enc = 1;
839 break;
840 case ALG_OP_DECRYPT:
841 enc = 0;
842 break;
843 default:
844 return -EINVAL;
845 }
846
847 if (con.iv && con.iv->ivlen != ivsize)
848 return -EINVAL;
849 }
850
851 lock_sock(sk);
852 if (!ctx->more && ctx->used) {
853 err = -EINVAL;
854 goto unlock;
855 }
856
857 if (init) {
858 ctx->enc = enc;
859 if (con.iv)
860 memcpy(ctx->iv, con.iv->iv, ivsize);
861
862 ctx->aead_assoclen = con.aead_assoclen;
863 }
864
865 while (size) {
866 struct scatterlist *sg;
867 size_t len = size;
868 size_t plen;
869
870 /* use the existing memory in an allocated page */
871 if (ctx->merge) {
872 sgl = list_entry(ctx->tsgl_list.prev,
873 struct af_alg_tsgl, list);
874 sg = sgl->sg + sgl->cur - 1;
875 len = min_t(size_t, len,
876 PAGE_SIZE - sg->offset - sg->length);
877
878 err = memcpy_from_msg(page_address(sg_page(sg)) +
879 sg->offset + sg->length,
880 msg, len);
881 if (err)
882 goto unlock;
883
884 sg->length += len;
885 ctx->merge = (sg->offset + sg->length) &
886 (PAGE_SIZE - 1);
887
888 ctx->used += len;
889 copied += len;
890 size -= len;
891 continue;
892 }
893
894 if (!af_alg_writable(sk)) {
895 err = af_alg_wait_for_wmem(sk, msg->msg_flags);
896 if (err)
897 goto unlock;
898 }
899
900 /* allocate a new page */
901 len = min_t(unsigned long, len, af_alg_sndbuf(sk));
902
903 err = af_alg_alloc_tsgl(sk);
904 if (err)
905 goto unlock;
906
907 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
908 list);
909 sg = sgl->sg;
910 if (sgl->cur)
911 sg_unmark_end(sg + sgl->cur - 1);
912
913 do {
914 unsigned int i = sgl->cur;
915
916 plen = min_t(size_t, len, PAGE_SIZE);
917
918 sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
919 if (!sg_page(sg + i)) {
920 err = -ENOMEM;
921 goto unlock;
922 }
923
924 err = memcpy_from_msg(page_address(sg_page(sg + i)),
925 msg, plen);
926 if (err) {
927 __free_page(sg_page(sg + i));
928 sg_assign_page(sg + i, NULL);
929 goto unlock;
930 }
931
932 sg[i].length = plen;
933 len -= plen;
934 ctx->used += plen;
935 copied += plen;
936 size -= plen;
937 sgl->cur++;
938 } while (len && sgl->cur < MAX_SGL_ENTS);
939
940 if (!size)
941 sg_mark_end(sg + sgl->cur - 1);
942
943 ctx->merge = plen & (PAGE_SIZE - 1);
944 }
945
946 err = 0;
947
948 ctx->more = msg->msg_flags & MSG_MORE;
949
950 unlock:
951 af_alg_data_wakeup(sk);
952 release_sock(sk);
953
954 return copied ?: err;
955 }
956 EXPORT_SYMBOL_GPL(af_alg_sendmsg);
957
958 /**
959 * af_alg_sendpage - sendpage system call handler
960 *
961 * This is a generic implementation of sendpage to fill ctx->tsgl_list.
962 */
963 ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
964 int offset, size_t size, int flags)
965 {
966 struct sock *sk = sock->sk;
967 struct alg_sock *ask = alg_sk(sk);
968 struct af_alg_ctx *ctx = ask->private;
969 struct af_alg_tsgl *sgl;
970 int err = -EINVAL;
971
972 if (flags & MSG_SENDPAGE_NOTLAST)
973 flags |= MSG_MORE;
974
975 lock_sock(sk);
976 if (!ctx->more && ctx->used)
977 goto unlock;
978
979 if (!size)
980 goto done;
981
982 if (!af_alg_writable(sk)) {
983 err = af_alg_wait_for_wmem(sk, flags);
984 if (err)
985 goto unlock;
986 }
987
988 err = af_alg_alloc_tsgl(sk);
989 if (err)
990 goto unlock;
991
992 ctx->merge = 0;
993 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
994
995 if (sgl->cur)
996 sg_unmark_end(sgl->sg + sgl->cur - 1);
997
998 sg_mark_end(sgl->sg + sgl->cur);
999
1000 get_page(page);
1001 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
1002 sgl->cur++;
1003 ctx->used += size;
1004
1005 done:
1006 ctx->more = flags & MSG_MORE;
1007
1008 unlock:
1009 af_alg_data_wakeup(sk);
1010 release_sock(sk);
1011
1012 return err ?: size;
1013 }
1014 EXPORT_SYMBOL_GPL(af_alg_sendpage);
1015
1016 /**
1017 * af_alg_free_resources - release resources required for crypto request
1018 */
1019 void af_alg_free_resources(struct af_alg_async_req *areq)
1020 {
1021 struct sock *sk = areq->sk;
1022
1023 af_alg_free_areq_sgls(areq);
1024 sock_kfree_s(sk, areq, areq->areqlen);
1025 }
1026 EXPORT_SYMBOL_GPL(af_alg_free_resources);
1027
1028 /**
1029 * af_alg_async_cb - AIO callback handler
1030 *
1031 * This handler cleans up the struct af_alg_async_req upon completion of the
1032 * AIO operation.
1033 *
1034 * The number of bytes to be generated with the AIO operation must be set
1035 * in areq->outlen before the AIO callback handler is invoked.
1036 */
1037 void af_alg_async_cb(struct crypto_async_request *_req, int err)
1038 {
1039 struct af_alg_async_req *areq = _req->data;
1040 struct sock *sk = areq->sk;
1041 struct kiocb *iocb = areq->iocb;
1042 unsigned int resultlen;
1043
1044 /* Buffer size written by crypto operation. */
1045 resultlen = areq->outlen;
1046
1047 af_alg_free_resources(areq);
1048 sock_put(sk);
1049
1050 iocb->ki_complete(iocb, err ? err : resultlen, 0);
1051 }
1052 EXPORT_SYMBOL_GPL(af_alg_async_cb);
1053
1054 /**
1055 * af_alg_poll - poll system call handler
1056 */
1057 __poll_t af_alg_poll(struct file *file, struct socket *sock,
1058 poll_table *wait)
1059 {
1060 struct sock *sk = sock->sk;
1061 struct alg_sock *ask = alg_sk(sk);
1062 struct af_alg_ctx *ctx = ask->private;
1063 __poll_t mask;
1064
1065 sock_poll_wait(file, sock, wait);
1066 mask = 0;
1067
1068 if (!ctx->more || ctx->used)
1069 mask |= EPOLLIN | EPOLLRDNORM;
1070
1071 if (af_alg_writable(sk))
1072 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1073
1074 return mask;
1075 }
1076 EXPORT_SYMBOL_GPL(af_alg_poll);
1077
1078 /**
1079 * af_alg_alloc_areq - allocate struct af_alg_async_req
1080 *
1081 * @sk socket of connection to user space
1082 * @areqlen size of struct af_alg_async_req + crypto_*_reqsize
1083 * @return allocated data structure or ERR_PTR upon error
1084 */
1085 struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
1086 unsigned int areqlen)
1087 {
1088 struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
1089
1090 if (unlikely(!areq))
1091 return ERR_PTR(-ENOMEM);
1092
1093 areq->areqlen = areqlen;
1094 areq->sk = sk;
1095 areq->last_rsgl = NULL;
1096 INIT_LIST_HEAD(&areq->rsgl_list);
1097 areq->tsgl = NULL;
1098 areq->tsgl_entries = 0;
1099
1100 return areq;
1101 }
1102 EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
1103
1104 /**
1105 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1106 * operation
1107 *
1108 * @sk socket of connection to user space
1109 * @msg user space message
1110 * @flags flags used to invoke recvmsg with
1111 * @areq instance of the cryptographic request that will hold the RX SGL
1112 * @maxsize maximum number of bytes to be pulled from user space
1113 * @outlen number of bytes in the RX SGL
1114 * @return 0 on success, < 0 upon error
1115 */
1116 int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
1117 struct af_alg_async_req *areq, size_t maxsize,
1118 size_t *outlen)
1119 {
1120 struct alg_sock *ask = alg_sk(sk);
1121 struct af_alg_ctx *ctx = ask->private;
1122 size_t len = 0;
1123
1124 while (maxsize > len && msg_data_left(msg)) {
1125 struct af_alg_rsgl *rsgl;
1126 size_t seglen;
1127 int err;
1128
1129 /* limit the amount of readable buffers */
1130 if (!af_alg_readable(sk))
1131 break;
1132
1133 seglen = min_t(size_t, (maxsize - len),
1134 msg_data_left(msg));
1135
1136 if (list_empty(&areq->rsgl_list)) {
1137 rsgl = &areq->first_rsgl;
1138 } else {
1139 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
1140 if (unlikely(!rsgl))
1141 return -ENOMEM;
1142 }
1143
1144 rsgl->sgl.npages = 0;
1145 list_add_tail(&rsgl->list, &areq->rsgl_list);
1146
1147 /* make one iovec available as scatterlist */
1148 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
1149 if (err < 0) {
1150 rsgl->sg_num_bytes = 0;
1151 return err;
1152 }
1153
1154 /* chain the new scatterlist with previous one */
1155 if (areq->last_rsgl)
1156 af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
1157
1158 areq->last_rsgl = rsgl;
1159 len += err;
1160 atomic_add(err, &ctx->rcvused);
1161 rsgl->sg_num_bytes = err;
1162 iov_iter_advance(&msg->msg_iter, err);
1163 }
1164
1165 *outlen = len;
1166 return 0;
1167 }
1168 EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
1169
1170 static int __init af_alg_init(void)
1171 {
1172 int err = proto_register(&alg_proto, 0);
1173
1174 if (err)
1175 goto out;
1176
1177 err = sock_register(&alg_family);
1178 if (err != 0)
1179 goto out_unregister_proto;
1180
1181 out:
1182 return err;
1183
1184 out_unregister_proto:
1185 proto_unregister(&alg_proto);
1186 goto out;
1187 }
1188
1189 static void __exit af_alg_exit(void)
1190 {
1191 sock_unregister(PF_ALG);
1192 proto_unregister(&alg_proto);
1193 }
1194
1195 module_init(af_alg_init);
1196 module_exit(af_alg_exit);
1197 MODULE_LICENSE("GPL");
1198 MODULE_ALIAS_NETPROTO(AF_ALG);
Mirror https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git