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Merge tag 'apparmor-pr-2020-06-07' of git://git.kernel.org/pub/scm/linux/kernel/git...
[mirror_ubuntu-jammy-kernel.git] / crypto / af_alg.c
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 = ask->nokey_refcnt;
132 bool last = nokey && !ask->refcnt;
133
134 sk = ask->parent;
135 ask = alg_sk(sk);
136
137 local_bh_disable();
138 bh_lock_sock(sk);
139 ask->nokey_refcnt -= nokey;
140 if (!last)
141 last = !--ask->refcnt;
142 bh_unlock_sock(sk);
143 local_bh_enable();
144
145 if (last)
146 sock_put(sk);
147 }
148 EXPORT_SYMBOL_GPL(af_alg_release_parent);
149
150 static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
151 {
152 const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY;
153 struct sock *sk = sock->sk;
154 struct alg_sock *ask = alg_sk(sk);
155 struct sockaddr_alg *sa = (void *)uaddr;
156 const struct af_alg_type *type;
157 void *private;
158 int err;
159
160 if (sock->state == SS_CONNECTED)
161 return -EINVAL;
162
163 if (addr_len < sizeof(*sa))
164 return -EINVAL;
165
166 /* If caller uses non-allowed flag, return error. */
167 if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed))
168 return -EINVAL;
169
170 sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
171 sa->salg_name[sizeof(sa->salg_name) + addr_len - sizeof(*sa) - 1] = 0;
172
173 type = alg_get_type(sa->salg_type);
174 if (PTR_ERR(type) == -ENOENT) {
175 request_module("algif-%s", sa->salg_type);
176 type = alg_get_type(sa->salg_type);
177 }
178
179 if (IS_ERR(type))
180 return PTR_ERR(type);
181
182 private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask);
183 if (IS_ERR(private)) {
184 module_put(type->owner);
185 return PTR_ERR(private);
186 }
187
188 err = -EBUSY;
189 lock_sock(sk);
190 if (ask->refcnt | ask->nokey_refcnt)
191 goto unlock;
192
193 swap(ask->type, type);
194 swap(ask->private, private);
195
196 err = 0;
197
198 unlock:
199 release_sock(sk);
200
201 alg_do_release(type, private);
202
203 return err;
204 }
205
206 static int alg_setkey(struct sock *sk, char __user *ukey,
207 unsigned int keylen)
208 {
209 struct alg_sock *ask = alg_sk(sk);
210 const struct af_alg_type *type = ask->type;
211 u8 *key;
212 int err;
213
214 key = sock_kmalloc(sk, keylen, GFP_KERNEL);
215 if (!key)
216 return -ENOMEM;
217
218 err = -EFAULT;
219 if (copy_from_user(key, ukey, keylen))
220 goto out;
221
222 err = type->setkey(ask->private, key, keylen);
223
224 out:
225 sock_kzfree_s(sk, key, keylen);
226
227 return err;
228 }
229
230 static int alg_setsockopt(struct socket *sock, int level, int optname,
231 char __user *optval, unsigned int optlen)
232 {
233 struct sock *sk = sock->sk;
234 struct alg_sock *ask = alg_sk(sk);
235 const struct af_alg_type *type;
236 int err = -EBUSY;
237
238 lock_sock(sk);
239 if (ask->refcnt)
240 goto unlock;
241
242 type = ask->type;
243
244 err = -ENOPROTOOPT;
245 if (level != SOL_ALG || !type)
246 goto unlock;
247
248 switch (optname) {
249 case ALG_SET_KEY:
250 if (sock->state == SS_CONNECTED)
251 goto unlock;
252 if (!type->setkey)
253 goto unlock;
254
255 err = alg_setkey(sk, optval, optlen);
256 break;
257 case ALG_SET_AEAD_AUTHSIZE:
258 if (sock->state == SS_CONNECTED)
259 goto unlock;
260 if (!type->setauthsize)
261 goto unlock;
262 err = type->setauthsize(ask->private, optlen);
263 }
264
265 unlock:
266 release_sock(sk);
267
268 return err;
269 }
270
271 int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern)
272 {
273 struct alg_sock *ask = alg_sk(sk);
274 const struct af_alg_type *type;
275 struct sock *sk2;
276 unsigned int nokey;
277 int err;
278
279 lock_sock(sk);
280 type = ask->type;
281
282 err = -EINVAL;
283 if (!type)
284 goto unlock;
285
286 sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, kern);
287 err = -ENOMEM;
288 if (!sk2)
289 goto unlock;
290
291 sock_init_data(newsock, sk2);
292 security_sock_graft(sk2, newsock);
293 security_sk_clone(sk, sk2);
294
295 err = type->accept(ask->private, sk2);
296
297 nokey = err == -ENOKEY;
298 if (nokey && type->accept_nokey)
299 err = type->accept_nokey(ask->private, sk2);
300
301 if (err)
302 goto unlock;
303
304 if (nokey || !ask->refcnt++)
305 sock_hold(sk);
306 ask->nokey_refcnt += nokey;
307 alg_sk(sk2)->parent = sk;
308 alg_sk(sk2)->type = type;
309 alg_sk(sk2)->nokey_refcnt = nokey;
310
311 newsock->ops = type->ops;
312 newsock->state = SS_CONNECTED;
313
314 if (nokey)
315 newsock->ops = type->ops_nokey;
316
317 err = 0;
318
319 unlock:
320 release_sock(sk);
321
322 return err;
323 }
324 EXPORT_SYMBOL_GPL(af_alg_accept);
325
326 static int alg_accept(struct socket *sock, struct socket *newsock, int flags,
327 bool kern)
328 {
329 return af_alg_accept(sock->sk, newsock, kern);
330 }
331
332 static const struct proto_ops alg_proto_ops = {
333 .family = PF_ALG,
334 .owner = THIS_MODULE,
335
336 .connect = sock_no_connect,
337 .socketpair = sock_no_socketpair,
338 .getname = sock_no_getname,
339 .ioctl = sock_no_ioctl,
340 .listen = sock_no_listen,
341 .shutdown = sock_no_shutdown,
342 .getsockopt = sock_no_getsockopt,
343 .mmap = sock_no_mmap,
344 .sendpage = sock_no_sendpage,
345 .sendmsg = sock_no_sendmsg,
346 .recvmsg = sock_no_recvmsg,
347
348 .bind = alg_bind,
349 .release = af_alg_release,
350 .setsockopt = alg_setsockopt,
351 .accept = alg_accept,
352 };
353
354 static void alg_sock_destruct(struct sock *sk)
355 {
356 struct alg_sock *ask = alg_sk(sk);
357
358 alg_do_release(ask->type, ask->private);
359 }
360
361 static int alg_create(struct net *net, struct socket *sock, int protocol,
362 int kern)
363 {
364 struct sock *sk;
365 int err;
366
367 if (sock->type != SOCK_SEQPACKET)
368 return -ESOCKTNOSUPPORT;
369 if (protocol != 0)
370 return -EPROTONOSUPPORT;
371
372 err = -ENOMEM;
373 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
374 if (!sk)
375 goto out;
376
377 sock->ops = &alg_proto_ops;
378 sock_init_data(sock, sk);
379
380 sk->sk_destruct = alg_sock_destruct;
381
382 return 0;
383 out:
384 return err;
385 }
386
387 static const struct net_proto_family alg_family = {
388 .family = PF_ALG,
389 .create = alg_create,
390 .owner = THIS_MODULE,
391 };
392
393 int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
394 {
395 size_t off;
396 ssize_t n;
397 int npages, i;
398
399 n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
400 if (n < 0)
401 return n;
402
403 npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT;
404 if (WARN_ON(npages == 0))
405 return -EINVAL;
406 /* Add one extra for linking */
407 sg_init_table(sgl->sg, npages + 1);
408
409 for (i = 0, len = n; i < npages; i++) {
410 int plen = min_t(int, len, PAGE_SIZE - off);
411
412 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
413
414 off = 0;
415 len -= plen;
416 }
417 sg_mark_end(sgl->sg + npages - 1);
418 sgl->npages = npages;
419
420 return n;
421 }
422 EXPORT_SYMBOL_GPL(af_alg_make_sg);
423
424 static void af_alg_link_sg(struct af_alg_sgl *sgl_prev,
425 struct af_alg_sgl *sgl_new)
426 {
427 sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
428 sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
429 }
430
431 void af_alg_free_sg(struct af_alg_sgl *sgl)
432 {
433 int i;
434
435 for (i = 0; i < sgl->npages; i++)
436 put_page(sgl->pages[i]);
437 }
438 EXPORT_SYMBOL_GPL(af_alg_free_sg);
439
440 static int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
441 {
442 struct cmsghdr *cmsg;
443
444 for_each_cmsghdr(cmsg, msg) {
445 if (!CMSG_OK(msg, cmsg))
446 return -EINVAL;
447 if (cmsg->cmsg_level != SOL_ALG)
448 continue;
449
450 switch (cmsg->cmsg_type) {
451 case ALG_SET_IV:
452 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
453 return -EINVAL;
454 con->iv = (void *)CMSG_DATA(cmsg);
455 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
456 sizeof(*con->iv)))
457 return -EINVAL;
458 break;
459
460 case ALG_SET_OP:
461 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
462 return -EINVAL;
463 con->op = *(u32 *)CMSG_DATA(cmsg);
464 break;
465
466 case ALG_SET_AEAD_ASSOCLEN:
467 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
468 return -EINVAL;
469 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
470 break;
471
472 default:
473 return -EINVAL;
474 }
475 }
476
477 return 0;
478 }
479
480 /**
481 * af_alg_alloc_tsgl - allocate the TX SGL
482 *
483 * @sk socket of connection to user space
484 * @return: 0 upon success, < 0 upon error
485 */
486 static int af_alg_alloc_tsgl(struct sock *sk)
487 {
488 struct alg_sock *ask = alg_sk(sk);
489 struct af_alg_ctx *ctx = ask->private;
490 struct af_alg_tsgl *sgl;
491 struct scatterlist *sg = NULL;
492
493 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
494 if (!list_empty(&ctx->tsgl_list))
495 sg = sgl->sg;
496
497 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
498 sgl = sock_kmalloc(sk,
499 struct_size(sgl, sg, (MAX_SGL_ENTS + 1)),
500 GFP_KERNEL);
501 if (!sgl)
502 return -ENOMEM;
503
504 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
505 sgl->cur = 0;
506
507 if (sg)
508 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
509
510 list_add_tail(&sgl->list, &ctx->tsgl_list);
511 }
512
513 return 0;
514 }
515
516 /**
517 * aead_count_tsgl - Count number of TX SG entries
518 *
519 * The counting starts from the beginning of the SGL to @bytes. If
520 * an offset is provided, the counting of the SG entries starts at the offset.
521 *
522 * @sk socket of connection to user space
523 * @bytes Count the number of SG entries holding given number of bytes.
524 * @offset Start the counting of SG entries from the given offset.
525 * @return Number of TX SG entries found given the constraints
526 */
527 unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
528 {
529 const struct alg_sock *ask = alg_sk(sk);
530 const struct af_alg_ctx *ctx = ask->private;
531 const struct af_alg_tsgl *sgl;
532 unsigned int i;
533 unsigned int sgl_count = 0;
534
535 if (!bytes)
536 return 0;
537
538 list_for_each_entry(sgl, &ctx->tsgl_list, list) {
539 const struct scatterlist *sg = sgl->sg;
540
541 for (i = 0; i < sgl->cur; i++) {
542 size_t bytes_count;
543
544 /* Skip offset */
545 if (offset >= sg[i].length) {
546 offset -= sg[i].length;
547 bytes -= sg[i].length;
548 continue;
549 }
550
551 bytes_count = sg[i].length - offset;
552
553 offset = 0;
554 sgl_count++;
555
556 /* If we have seen requested number of bytes, stop */
557 if (bytes_count >= bytes)
558 return sgl_count;
559
560 bytes -= bytes_count;
561 }
562 }
563
564 return sgl_count;
565 }
566 EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
567
568 /**
569 * aead_pull_tsgl - Release the specified buffers from TX SGL
570 *
571 * If @dst is non-null, reassign the pages to dst. The caller must release
572 * the pages. If @dst_offset is given only reassign the pages to @dst starting
573 * at the @dst_offset (byte). The caller must ensure that @dst is large
574 * enough (e.g. by using af_alg_count_tsgl with the same offset).
575 *
576 * @sk socket of connection to user space
577 * @used Number of bytes to pull from TX SGL
578 * @dst If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
579 * caller must release the buffers in dst.
580 * @dst_offset Reassign the TX SGL from given offset. All buffers before
581 * reaching the offset is released.
582 */
583 void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
584 size_t dst_offset)
585 {
586 struct alg_sock *ask = alg_sk(sk);
587 struct af_alg_ctx *ctx = ask->private;
588 struct af_alg_tsgl *sgl;
589 struct scatterlist *sg;
590 unsigned int i, j = 0;
591
592 while (!list_empty(&ctx->tsgl_list)) {
593 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
594 list);
595 sg = sgl->sg;
596
597 for (i = 0; i < sgl->cur; i++) {
598 size_t plen = min_t(size_t, used, sg[i].length);
599 struct page *page = sg_page(sg + i);
600
601 if (!page)
602 continue;
603
604 /*
605 * Assumption: caller created af_alg_count_tsgl(len)
606 * SG entries in dst.
607 */
608 if (dst) {
609 if (dst_offset >= plen) {
610 /* discard page before offset */
611 dst_offset -= plen;
612 } else {
613 /* reassign page to dst after offset */
614 get_page(page);
615 sg_set_page(dst + j, page,
616 plen - dst_offset,
617 sg[i].offset + dst_offset);
618 dst_offset = 0;
619 j++;
620 }
621 }
622
623 sg[i].length -= plen;
624 sg[i].offset += plen;
625
626 used -= plen;
627 ctx->used -= plen;
628
629 if (sg[i].length)
630 return;
631
632 put_page(page);
633 sg_assign_page(sg + i, NULL);
634 }
635
636 list_del(&sgl->list);
637 sock_kfree_s(sk, sgl, struct_size(sgl, sg, MAX_SGL_ENTS + 1));
638 }
639
640 if (!ctx->used)
641 ctx->merge = 0;
642 }
643 EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
644
645 /**
646 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
647 *
648 * @areq Request holding the TX and RX SGL
649 */
650 static void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
651 {
652 struct sock *sk = areq->sk;
653 struct alg_sock *ask = alg_sk(sk);
654 struct af_alg_ctx *ctx = ask->private;
655 struct af_alg_rsgl *rsgl, *tmp;
656 struct scatterlist *tsgl;
657 struct scatterlist *sg;
658 unsigned int i;
659
660 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
661 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
662 af_alg_free_sg(&rsgl->sgl);
663 list_del(&rsgl->list);
664 if (rsgl != &areq->first_rsgl)
665 sock_kfree_s(sk, rsgl, sizeof(*rsgl));
666 }
667
668 tsgl = areq->tsgl;
669 if (tsgl) {
670 for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
671 if (!sg_page(sg))
672 continue;
673 put_page(sg_page(sg));
674 }
675
676 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
677 }
678 }
679
680 /**
681 * af_alg_wait_for_wmem - wait for availability of writable memory
682 *
683 * @sk socket of connection to user space
684 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
685 * @return 0 when writable memory is available, < 0 upon error
686 */
687 static int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
688 {
689 DEFINE_WAIT_FUNC(wait, woken_wake_function);
690 int err = -ERESTARTSYS;
691 long timeout;
692
693 if (flags & MSG_DONTWAIT)
694 return -EAGAIN;
695
696 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
697
698 add_wait_queue(sk_sleep(sk), &wait);
699 for (;;) {
700 if (signal_pending(current))
701 break;
702 timeout = MAX_SCHEDULE_TIMEOUT;
703 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
704 err = 0;
705 break;
706 }
707 }
708 remove_wait_queue(sk_sleep(sk), &wait);
709
710 return err;
711 }
712
713 /**
714 * af_alg_wmem_wakeup - wakeup caller when writable memory is available
715 *
716 * @sk socket of connection to user space
717 */
718 void af_alg_wmem_wakeup(struct sock *sk)
719 {
720 struct socket_wq *wq;
721
722 if (!af_alg_writable(sk))
723 return;
724
725 rcu_read_lock();
726 wq = rcu_dereference(sk->sk_wq);
727 if (skwq_has_sleeper(wq))
728 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN |
729 EPOLLRDNORM |
730 EPOLLRDBAND);
731 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
732 rcu_read_unlock();
733 }
734 EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
735
736 /**
737 * af_alg_wait_for_data - wait for availability of TX data
738 *
739 * @sk socket of connection to user space
740 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
741 * @return 0 when writable memory is available, < 0 upon error
742 */
743 int af_alg_wait_for_data(struct sock *sk, unsigned flags)
744 {
745 DEFINE_WAIT_FUNC(wait, woken_wake_function);
746 struct alg_sock *ask = alg_sk(sk);
747 struct af_alg_ctx *ctx = ask->private;
748 long timeout;
749 int err = -ERESTARTSYS;
750
751 if (flags & MSG_DONTWAIT)
752 return -EAGAIN;
753
754 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
755
756 add_wait_queue(sk_sleep(sk), &wait);
757 for (;;) {
758 if (signal_pending(current))
759 break;
760 timeout = MAX_SCHEDULE_TIMEOUT;
761 if (sk_wait_event(sk, &timeout, (ctx->used || !ctx->more),
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->more && ctx->used) {
851 err = -EINVAL;
852 goto unlock;
853 }
854
855 if (init) {
856 ctx->enc = enc;
857 if (con.iv)
858 memcpy(ctx->iv, con.iv->iv, ivsize);
859
860 ctx->aead_assoclen = con.aead_assoclen;
861 }
862
863 while (size) {
864 struct scatterlist *sg;
865 size_t len = size;
866 size_t plen;
867
868 /* use the existing memory in an allocated page */
869 if (ctx->merge) {
870 sgl = list_entry(ctx->tsgl_list.prev,
871 struct af_alg_tsgl, list);
872 sg = sgl->sg + sgl->cur - 1;
873 len = min_t(size_t, len,
874 PAGE_SIZE - sg->offset - sg->length);
875
876 err = memcpy_from_msg(page_address(sg_page(sg)) +
877 sg->offset + sg->length,
878 msg, len);
879 if (err)
880 goto unlock;
881
882 sg->length += len;
883 ctx->merge = (sg->offset + sg->length) &
884 (PAGE_SIZE - 1);
885
886 ctx->used += len;
887 copied += len;
888 size -= len;
889 continue;
890 }
891
892 if (!af_alg_writable(sk)) {
893 err = af_alg_wait_for_wmem(sk, msg->msg_flags);
894 if (err)
895 goto unlock;
896 }
897
898 /* allocate a new page */
899 len = min_t(unsigned long, len, af_alg_sndbuf(sk));
900
901 err = af_alg_alloc_tsgl(sk);
902 if (err)
903 goto unlock;
904
905 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
906 list);
907 sg = sgl->sg;
908 if (sgl->cur)
909 sg_unmark_end(sg + sgl->cur - 1);
910
911 do {
912 unsigned int i = sgl->cur;
913
914 plen = min_t(size_t, len, PAGE_SIZE);
915
916 sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
917 if (!sg_page(sg + i)) {
918 err = -ENOMEM;
919 goto unlock;
920 }
921
922 err = memcpy_from_msg(page_address(sg_page(sg + i)),
923 msg, plen);
924 if (err) {
925 __free_page(sg_page(sg + i));
926 sg_assign_page(sg + i, NULL);
927 goto unlock;
928 }
929
930 sg[i].length = plen;
931 len -= plen;
932 ctx->used += plen;
933 copied += plen;
934 size -= plen;
935 sgl->cur++;
936 } while (len && sgl->cur < MAX_SGL_ENTS);
937
938 if (!size)
939 sg_mark_end(sg + sgl->cur - 1);
940
941 ctx->merge = plen & (PAGE_SIZE - 1);
942 }
943
944 err = 0;
945
946 ctx->more = msg->msg_flags & MSG_MORE;
947
948 unlock:
949 af_alg_data_wakeup(sk);
950 release_sock(sk);
951
952 return copied ?: err;
953 }
954 EXPORT_SYMBOL_GPL(af_alg_sendmsg);
955
956 /**
957 * af_alg_sendpage - sendpage system call handler
958 *
959 * This is a generic implementation of sendpage to fill ctx->tsgl_list.
960 */
961 ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
962 int offset, size_t size, int flags)
963 {
964 struct sock *sk = sock->sk;
965 struct alg_sock *ask = alg_sk(sk);
966 struct af_alg_ctx *ctx = ask->private;
967 struct af_alg_tsgl *sgl;
968 int err = -EINVAL;
969
970 if (flags & MSG_SENDPAGE_NOTLAST)
971 flags |= MSG_MORE;
972
973 lock_sock(sk);
974 if (!ctx->more && ctx->used)
975 goto unlock;
976
977 if (!size)
978 goto done;
979
980 if (!af_alg_writable(sk)) {
981 err = af_alg_wait_for_wmem(sk, flags);
982 if (err)
983 goto unlock;
984 }
985
986 err = af_alg_alloc_tsgl(sk);
987 if (err)
988 goto unlock;
989
990 ctx->merge = 0;
991 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
992
993 if (sgl->cur)
994 sg_unmark_end(sgl->sg + sgl->cur - 1);
995
996 sg_mark_end(sgl->sg + sgl->cur);
997
998 get_page(page);
999 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
1000 sgl->cur++;
1001 ctx->used += size;
1002
1003 done:
1004 ctx->more = flags & MSG_MORE;
1005
1006 unlock:
1007 af_alg_data_wakeup(sk);
1008 release_sock(sk);
1009
1010 return err ?: size;
1011 }
1012 EXPORT_SYMBOL_GPL(af_alg_sendpage);
1013
1014 /**
1015 * af_alg_free_resources - release resources required for crypto request
1016 */
1017 void af_alg_free_resources(struct af_alg_async_req *areq)
1018 {
1019 struct sock *sk = areq->sk;
1020
1021 af_alg_free_areq_sgls(areq);
1022 sock_kfree_s(sk, areq, areq->areqlen);
1023 }
1024 EXPORT_SYMBOL_GPL(af_alg_free_resources);
1025
1026 /**
1027 * af_alg_async_cb - AIO callback handler
1028 *
1029 * This handler cleans up the struct af_alg_async_req upon completion of the
1030 * AIO operation.
1031 *
1032 * The number of bytes to be generated with the AIO operation must be set
1033 * in areq->outlen before the AIO callback handler is invoked.
1034 */
1035 void af_alg_async_cb(struct crypto_async_request *_req, int err)
1036 {
1037 struct af_alg_async_req *areq = _req->data;
1038 struct sock *sk = areq->sk;
1039 struct kiocb *iocb = areq->iocb;
1040 unsigned int resultlen;
1041
1042 /* Buffer size written by crypto operation. */
1043 resultlen = areq->outlen;
1044
1045 af_alg_free_resources(areq);
1046 sock_put(sk);
1047
1048 iocb->ki_complete(iocb, err ? err : (int)resultlen, 0);
1049 }
1050 EXPORT_SYMBOL_GPL(af_alg_async_cb);
1051
1052 /**
1053 * af_alg_poll - poll system call handler
1054 */
1055 __poll_t af_alg_poll(struct file *file, struct socket *sock,
1056 poll_table *wait)
1057 {
1058 struct sock *sk = sock->sk;
1059 struct alg_sock *ask = alg_sk(sk);
1060 struct af_alg_ctx *ctx = ask->private;
1061 __poll_t mask;
1062
1063 sock_poll_wait(file, sock, wait);
1064 mask = 0;
1065
1066 if (!ctx->more || ctx->used)
1067 mask |= EPOLLIN | EPOLLRDNORM;
1068
1069 if (af_alg_writable(sk))
1070 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1071
1072 return mask;
1073 }
1074 EXPORT_SYMBOL_GPL(af_alg_poll);
1075
1076 /**
1077 * af_alg_alloc_areq - allocate struct af_alg_async_req
1078 *
1079 * @sk socket of connection to user space
1080 * @areqlen size of struct af_alg_async_req + crypto_*_reqsize
1081 * @return allocated data structure or ERR_PTR upon error
1082 */
1083 struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
1084 unsigned int areqlen)
1085 {
1086 struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
1087
1088 if (unlikely(!areq))
1089 return ERR_PTR(-ENOMEM);
1090
1091 areq->areqlen = areqlen;
1092 areq->sk = sk;
1093 areq->last_rsgl = NULL;
1094 INIT_LIST_HEAD(&areq->rsgl_list);
1095 areq->tsgl = NULL;
1096 areq->tsgl_entries = 0;
1097
1098 return areq;
1099 }
1100 EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
1101
1102 /**
1103 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1104 * operation
1105 *
1106 * @sk socket of connection to user space
1107 * @msg user space message
1108 * @flags flags used to invoke recvmsg with
1109 * @areq instance of the cryptographic request that will hold the RX SGL
1110 * @maxsize maximum number of bytes to be pulled from user space
1111 * @outlen number of bytes in the RX SGL
1112 * @return 0 on success, < 0 upon error
1113 */
1114 int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
1115 struct af_alg_async_req *areq, size_t maxsize,
1116 size_t *outlen)
1117 {
1118 struct alg_sock *ask = alg_sk(sk);
1119 struct af_alg_ctx *ctx = ask->private;
1120 size_t len = 0;
1121
1122 while (maxsize > len && msg_data_left(msg)) {
1123 struct af_alg_rsgl *rsgl;
1124 size_t seglen;
1125 int err;
1126
1127 /* limit the amount of readable buffers */
1128 if (!af_alg_readable(sk))
1129 break;
1130
1131 seglen = min_t(size_t, (maxsize - len),
1132 msg_data_left(msg));
1133
1134 if (list_empty(&areq->rsgl_list)) {
1135 rsgl = &areq->first_rsgl;
1136 } else {
1137 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
1138 if (unlikely(!rsgl))
1139 return -ENOMEM;
1140 }
1141
1142 rsgl->sgl.npages = 0;
1143 list_add_tail(&rsgl->list, &areq->rsgl_list);
1144
1145 /* make one iovec available as scatterlist */
1146 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
1147 if (err < 0) {
1148 rsgl->sg_num_bytes = 0;
1149 return err;
1150 }
1151
1152 /* chain the new scatterlist with previous one */
1153 if (areq->last_rsgl)
1154 af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
1155
1156 areq->last_rsgl = rsgl;
1157 len += err;
1158 atomic_add(err, &ctx->rcvused);
1159 rsgl->sg_num_bytes = err;
1160 iov_iter_advance(&msg->msg_iter, err);
1161 }
1162
1163 *outlen = len;
1164 return 0;
1165 }
1166 EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
1167
1168 static int __init af_alg_init(void)
1169 {
1170 int err = proto_register(&alg_proto, 0);
1171
1172 if (err)
1173 goto out;
1174
1175 err = sock_register(&alg_family);
1176 if (err != 0)
1177 goto out_unregister_proto;
1178
1179 out:
1180 return err;
1181
1182 out_unregister_proto:
1183 proto_unregister(&alg_proto);
1184 goto out;
1185 }
1186
1187 static void __exit af_alg_exit(void)
1188 {
1189 sock_unregister(PF_ALG);
1190 proto_unregister(&alg_proto);
1191 }
1192
1193 module_init(af_alg_init);
1194 module_exit(af_alg_exit);
1195 MODULE_LICENSE("GPL");
1196 MODULE_ALIAS_NETPROTO(AF_ALG);
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