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crypto: af_alg - remove locking in async callback
[mirror_ubuntu-bionic-kernel.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 forbidden = CRYPTO_ALG_INTERNAL;
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 sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
168 sa->salg_name[sizeof(sa->salg_name) + addr_len - sizeof(*sa) - 1] = 0;
169
170 type = alg_get_type(sa->salg_type);
171 if (IS_ERR(type) && PTR_ERR(type) == -ENOENT) {
172 request_module("algif-%s", sa->salg_type);
173 type = alg_get_type(sa->salg_type);
174 }
175
176 if (IS_ERR(type))
177 return PTR_ERR(type);
178
179 private = type->bind(sa->salg_name,
180 sa->salg_feat & ~forbidden,
181 sa->salg_mask & ~forbidden);
182 if (IS_ERR(private)) {
183 module_put(type->owner);
184 return PTR_ERR(private);
185 }
186
187 err = -EBUSY;
188 lock_sock(sk);
189 if (ask->refcnt | ask->nokey_refcnt)
190 goto unlock;
191
192 swap(ask->type, type);
193 swap(ask->private, private);
194
195 err = 0;
196
197 unlock:
198 release_sock(sk);
199
200 alg_do_release(type, private);
201
202 return err;
203 }
204
205 static int alg_setkey(struct sock *sk, char __user *ukey,
206 unsigned int keylen)
207 {
208 struct alg_sock *ask = alg_sk(sk);
209 const struct af_alg_type *type = ask->type;
210 u8 *key;
211 int err;
212
213 key = sock_kmalloc(sk, keylen, GFP_KERNEL);
214 if (!key)
215 return -ENOMEM;
216
217 err = -EFAULT;
218 if (copy_from_user(key, ukey, keylen))
219 goto out;
220
221 err = type->setkey(ask->private, key, keylen);
222
223 out:
224 sock_kzfree_s(sk, key, keylen);
225
226 return err;
227 }
228
229 static int alg_setsockopt(struct socket *sock, int level, int optname,
230 char __user *optval, unsigned int optlen)
231 {
232 struct sock *sk = sock->sk;
233 struct alg_sock *ask = alg_sk(sk);
234 const struct af_alg_type *type;
235 int err = -EBUSY;
236
237 lock_sock(sk);
238 if (ask->refcnt)
239 goto unlock;
240
241 type = ask->type;
242
243 err = -ENOPROTOOPT;
244 if (level != SOL_ALG || !type)
245 goto unlock;
246
247 switch (optname) {
248 case ALG_SET_KEY:
249 if (sock->state == SS_CONNECTED)
250 goto unlock;
251 if (!type->setkey)
252 goto unlock;
253
254 err = alg_setkey(sk, optval, optlen);
255 break;
256 case ALG_SET_AEAD_AUTHSIZE:
257 if (sock->state == SS_CONNECTED)
258 goto unlock;
259 if (!type->setauthsize)
260 goto unlock;
261 err = type->setauthsize(ask->private, optlen);
262 }
263
264 unlock:
265 release_sock(sk);
266
267 return err;
268 }
269
270 int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern)
271 {
272 struct alg_sock *ask = alg_sk(sk);
273 const struct af_alg_type *type;
274 struct sock *sk2;
275 unsigned int nokey;
276 int err;
277
278 lock_sock(sk);
279 type = ask->type;
280
281 err = -EINVAL;
282 if (!type)
283 goto unlock;
284
285 sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, kern);
286 err = -ENOMEM;
287 if (!sk2)
288 goto unlock;
289
290 sock_init_data(newsock, sk2);
291 security_sock_graft(sk2, newsock);
292 security_sk_clone(sk, sk2);
293
294 err = type->accept(ask->private, sk2);
295
296 nokey = err == -ENOKEY;
297 if (nokey && type->accept_nokey)
298 err = type->accept_nokey(ask->private, sk2);
299
300 if (err)
301 goto unlock;
302
303 sk2->sk_family = PF_ALG;
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 .poll = sock_no_poll,
349
350 .bind = alg_bind,
351 .release = af_alg_release,
352 .setsockopt = alg_setsockopt,
353 .accept = alg_accept,
354 };
355
356 static void alg_sock_destruct(struct sock *sk)
357 {
358 struct alg_sock *ask = alg_sk(sk);
359
360 alg_do_release(ask->type, ask->private);
361 }
362
363 static int alg_create(struct net *net, struct socket *sock, int protocol,
364 int kern)
365 {
366 struct sock *sk;
367 int err;
368
369 if (sock->type != SOCK_SEQPACKET)
370 return -ESOCKTNOSUPPORT;
371 if (protocol != 0)
372 return -EPROTONOSUPPORT;
373
374 err = -ENOMEM;
375 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
376 if (!sk)
377 goto out;
378
379 sock->ops = &alg_proto_ops;
380 sock_init_data(sock, sk);
381
382 sk->sk_family = PF_ALG;
383 sk->sk_destruct = alg_sock_destruct;
384
385 return 0;
386 out:
387 return err;
388 }
389
390 static const struct net_proto_family alg_family = {
391 .family = PF_ALG,
392 .create = alg_create,
393 .owner = THIS_MODULE,
394 };
395
396 int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
397 {
398 size_t off;
399 ssize_t n;
400 int npages, i;
401
402 n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
403 if (n < 0)
404 return n;
405
406 npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT;
407 if (WARN_ON(npages == 0))
408 return -EINVAL;
409 /* Add one extra for linking */
410 sg_init_table(sgl->sg, npages + 1);
411
412 for (i = 0, len = n; i < npages; i++) {
413 int plen = min_t(int, len, PAGE_SIZE - off);
414
415 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
416
417 off = 0;
418 len -= plen;
419 }
420 sg_mark_end(sgl->sg + npages - 1);
421 sgl->npages = npages;
422
423 return n;
424 }
425 EXPORT_SYMBOL_GPL(af_alg_make_sg);
426
427 void af_alg_link_sg(struct af_alg_sgl *sgl_prev, struct af_alg_sgl *sgl_new)
428 {
429 sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
430 sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
431 }
432 EXPORT_SYMBOL_GPL(af_alg_link_sg);
433
434 void af_alg_free_sg(struct af_alg_sgl *sgl)
435 {
436 int i;
437
438 for (i = 0; i < sgl->npages; i++)
439 put_page(sgl->pages[i]);
440 }
441 EXPORT_SYMBOL_GPL(af_alg_free_sg);
442
443 int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
444 {
445 struct cmsghdr *cmsg;
446
447 for_each_cmsghdr(cmsg, msg) {
448 if (!CMSG_OK(msg, cmsg))
449 return -EINVAL;
450 if (cmsg->cmsg_level != SOL_ALG)
451 continue;
452
453 switch (cmsg->cmsg_type) {
454 case ALG_SET_IV:
455 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
456 return -EINVAL;
457 con->iv = (void *)CMSG_DATA(cmsg);
458 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
459 sizeof(*con->iv)))
460 return -EINVAL;
461 break;
462
463 case ALG_SET_OP:
464 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
465 return -EINVAL;
466 con->op = *(u32 *)CMSG_DATA(cmsg);
467 break;
468
469 case ALG_SET_AEAD_ASSOCLEN:
470 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
471 return -EINVAL;
472 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
473 break;
474
475 default:
476 return -EINVAL;
477 }
478 }
479
480 return 0;
481 }
482 EXPORT_SYMBOL_GPL(af_alg_cmsg_send);
483
484 /**
485 * af_alg_alloc_tsgl - allocate the TX SGL
486 *
487 * @sk socket of connection to user space
488 * @return: 0 upon success, < 0 upon error
489 */
490 int af_alg_alloc_tsgl(struct sock *sk)
491 {
492 struct alg_sock *ask = alg_sk(sk);
493 struct af_alg_ctx *ctx = ask->private;
494 struct af_alg_tsgl *sgl;
495 struct scatterlist *sg = NULL;
496
497 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
498 if (!list_empty(&ctx->tsgl_list))
499 sg = sgl->sg;
500
501 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
502 sgl = sock_kmalloc(sk, sizeof(*sgl) +
503 sizeof(sgl->sg[0]) * (MAX_SGL_ENTS + 1),
504 GFP_KERNEL);
505 if (!sgl)
506 return -ENOMEM;
507
508 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
509 sgl->cur = 0;
510
511 if (sg)
512 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
513
514 list_add_tail(&sgl->list, &ctx->tsgl_list);
515 }
516
517 return 0;
518 }
519 EXPORT_SYMBOL_GPL(af_alg_alloc_tsgl);
520
521 /**
522 * aead_count_tsgl - Count number of TX SG entries
523 *
524 * The counting starts from the beginning of the SGL to @bytes. If
525 * an offset is provided, the counting of the SG entries starts at the offset.
526 *
527 * @sk socket of connection to user space
528 * @bytes Count the number of SG entries holding given number of bytes.
529 * @offset Start the counting of SG entries from the given offset.
530 * @return Number of TX SG entries found given the constraints
531 */
532 unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
533 {
534 struct alg_sock *ask = alg_sk(sk);
535 struct af_alg_ctx *ctx = ask->private;
536 struct af_alg_tsgl *sgl, *tmp;
537 unsigned int i;
538 unsigned int sgl_count = 0;
539
540 if (!bytes)
541 return 0;
542
543 list_for_each_entry_safe(sgl, tmp, &ctx->tsgl_list, list) {
544 struct scatterlist *sg = sgl->sg;
545
546 for (i = 0; i < sgl->cur; i++) {
547 size_t bytes_count;
548
549 /* Skip offset */
550 if (offset >= sg[i].length) {
551 offset -= sg[i].length;
552 bytes -= sg[i].length;
553 continue;
554 }
555
556 bytes_count = sg[i].length - offset;
557
558 offset = 0;
559 sgl_count++;
560
561 /* If we have seen requested number of bytes, stop */
562 if (bytes_count >= bytes)
563 return sgl_count;
564
565 bytes -= bytes_count;
566 }
567 }
568
569 return sgl_count;
570 }
571 EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
572
573 /**
574 * aead_pull_tsgl - Release the specified buffers from TX SGL
575 *
576 * If @dst is non-null, reassign the pages to dst. The caller must release
577 * the pages. If @dst_offset is given only reassign the pages to @dst starting
578 * at the @dst_offset (byte). The caller must ensure that @dst is large
579 * enough (e.g. by using af_alg_count_tsgl with the same offset).
580 *
581 * @sk socket of connection to user space
582 * @used Number of bytes to pull from TX SGL
583 * @dst If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
584 * caller must release the buffers in dst.
585 * @dst_offset Reassign the TX SGL from given offset. All buffers before
586 * reaching the offset is released.
587 */
588 void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
589 size_t dst_offset)
590 {
591 struct alg_sock *ask = alg_sk(sk);
592 struct af_alg_ctx *ctx = ask->private;
593 struct af_alg_tsgl *sgl;
594 struct scatterlist *sg;
595 unsigned int i, j = 0;
596
597 while (!list_empty(&ctx->tsgl_list)) {
598 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
599 list);
600 sg = sgl->sg;
601
602 for (i = 0; i < sgl->cur; i++) {
603 size_t plen = min_t(size_t, used, sg[i].length);
604 struct page *page = sg_page(sg + i);
605
606 if (!page)
607 continue;
608
609 /*
610 * Assumption: caller created af_alg_count_tsgl(len)
611 * SG entries in dst.
612 */
613 if (dst) {
614 if (dst_offset >= plen) {
615 /* discard page before offset */
616 dst_offset -= plen;
617 } else {
618 /* reassign page to dst after offset */
619 get_page(page);
620 sg_set_page(dst + j, page,
621 plen - dst_offset,
622 sg[i].offset + dst_offset);
623 dst_offset = 0;
624 j++;
625 }
626 }
627
628 sg[i].length -= plen;
629 sg[i].offset += plen;
630
631 used -= plen;
632 ctx->used -= plen;
633
634 if (sg[i].length)
635 return;
636
637 put_page(page);
638 sg_assign_page(sg + i, NULL);
639 }
640
641 list_del(&sgl->list);
642 sock_kfree_s(sk, sgl, sizeof(*sgl) + sizeof(sgl->sg[0]) *
643 (MAX_SGL_ENTS + 1));
644 }
645
646 if (!ctx->used)
647 ctx->merge = 0;
648 }
649 EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
650
651 /**
652 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
653 *
654 * @areq Request holding the TX and RX SGL
655 */
656 void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
657 {
658 struct sock *sk = areq->sk;
659 struct alg_sock *ask = alg_sk(sk);
660 struct af_alg_ctx *ctx = ask->private;
661 struct af_alg_rsgl *rsgl, *tmp;
662 struct scatterlist *tsgl;
663 struct scatterlist *sg;
664 unsigned int i;
665
666 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
667 ctx->rcvused -= rsgl->sg_num_bytes;
668 af_alg_free_sg(&rsgl->sgl);
669 list_del(&rsgl->list);
670 if (rsgl != &areq->first_rsgl)
671 sock_kfree_s(sk, rsgl, sizeof(*rsgl));
672 }
673
674 tsgl = areq->tsgl;
675 for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
676 if (!sg_page(sg))
677 continue;
678 put_page(sg_page(sg));
679 }
680
681 if (areq->tsgl && areq->tsgl_entries)
682 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
683 }
684 EXPORT_SYMBOL_GPL(af_alg_free_areq_sgls);
685
686 /**
687 * af_alg_wait_for_wmem - wait for availability of writable memory
688 *
689 * @sk socket of connection to user space
690 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
691 * @return 0 when writable memory is available, < 0 upon error
692 */
693 int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
694 {
695 DEFINE_WAIT_FUNC(wait, woken_wake_function);
696 int err = -ERESTARTSYS;
697 long timeout;
698
699 if (flags & MSG_DONTWAIT)
700 return -EAGAIN;
701
702 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
703
704 add_wait_queue(sk_sleep(sk), &wait);
705 for (;;) {
706 if (signal_pending(current))
707 break;
708 timeout = MAX_SCHEDULE_TIMEOUT;
709 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
710 err = 0;
711 break;
712 }
713 }
714 remove_wait_queue(sk_sleep(sk), &wait);
715
716 return err;
717 }
718 EXPORT_SYMBOL_GPL(af_alg_wait_for_wmem);
719
720 /**
721 * af_alg_wmem_wakeup - wakeup caller when writable memory is available
722 *
723 * @sk socket of connection to user space
724 */
725 void af_alg_wmem_wakeup(struct sock *sk)
726 {
727 struct socket_wq *wq;
728
729 if (!af_alg_writable(sk))
730 return;
731
732 rcu_read_lock();
733 wq = rcu_dereference(sk->sk_wq);
734 if (skwq_has_sleeper(wq))
735 wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
736 POLLRDNORM |
737 POLLRDBAND);
738 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
739 rcu_read_unlock();
740 }
741 EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
742
743 /**
744 * af_alg_wait_for_data - wait for availability of TX data
745 *
746 * @sk socket of connection to user space
747 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
748 * @return 0 when writable memory is available, < 0 upon error
749 */
750 int af_alg_wait_for_data(struct sock *sk, unsigned flags)
751 {
752 DEFINE_WAIT_FUNC(wait, woken_wake_function);
753 struct alg_sock *ask = alg_sk(sk);
754 struct af_alg_ctx *ctx = ask->private;
755 long timeout;
756 int err = -ERESTARTSYS;
757
758 if (flags & MSG_DONTWAIT)
759 return -EAGAIN;
760
761 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
762
763 add_wait_queue(sk_sleep(sk), &wait);
764 for (;;) {
765 if (signal_pending(current))
766 break;
767 timeout = MAX_SCHEDULE_TIMEOUT;
768 if (sk_wait_event(sk, &timeout, (ctx->used || !ctx->more),
769 &wait)) {
770 err = 0;
771 break;
772 }
773 }
774 remove_wait_queue(sk_sleep(sk), &wait);
775
776 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
777
778 return err;
779 }
780 EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
781
782 /**
783 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
784 *
785 * @sk socket of connection to user space
786 */
787
788 void af_alg_data_wakeup(struct sock *sk)
789 {
790 struct alg_sock *ask = alg_sk(sk);
791 struct af_alg_ctx *ctx = ask->private;
792 struct socket_wq *wq;
793
794 if (!ctx->used)
795 return;
796
797 rcu_read_lock();
798 wq = rcu_dereference(sk->sk_wq);
799 if (skwq_has_sleeper(wq))
800 wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
801 POLLRDNORM |
802 POLLRDBAND);
803 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
804 rcu_read_unlock();
805 }
806 EXPORT_SYMBOL_GPL(af_alg_data_wakeup);
807
808 /**
809 * af_alg_sendmsg - implementation of sendmsg system call handler
810 *
811 * The sendmsg system call handler obtains the user data and stores it
812 * in ctx->tsgl_list. This implies allocation of the required numbers of
813 * struct af_alg_tsgl.
814 *
815 * In addition, the ctx is filled with the information sent via CMSG.
816 *
817 * @sock socket of connection to user space
818 * @msg message from user space
819 * @size size of message from user space
820 * @ivsize the size of the IV for the cipher operation to verify that the
821 * user-space-provided IV has the right size
822 * @return the number of copied data upon success, < 0 upon error
823 */
824 int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
825 unsigned int ivsize)
826 {
827 struct sock *sk = sock->sk;
828 struct alg_sock *ask = alg_sk(sk);
829 struct af_alg_ctx *ctx = ask->private;
830 struct af_alg_tsgl *sgl;
831 struct af_alg_control con = {};
832 long copied = 0;
833 bool enc = 0;
834 bool init = 0;
835 int err = 0;
836
837 if (msg->msg_controllen) {
838 err = af_alg_cmsg_send(msg, &con);
839 if (err)
840 return err;
841
842 init = 1;
843 switch (con.op) {
844 case ALG_OP_ENCRYPT:
845 enc = 1;
846 break;
847 case ALG_OP_DECRYPT:
848 enc = 0;
849 break;
850 default:
851 return -EINVAL;
852 }
853
854 if (con.iv && con.iv->ivlen != ivsize)
855 return -EINVAL;
856 }
857
858 lock_sock(sk);
859 if (!ctx->more && ctx->used) {
860 err = -EINVAL;
861 goto unlock;
862 }
863
864 if (init) {
865 ctx->enc = enc;
866 if (con.iv)
867 memcpy(ctx->iv, con.iv->iv, ivsize);
868
869 ctx->aead_assoclen = con.aead_assoclen;
870 }
871
872 while (size) {
873 struct scatterlist *sg;
874 size_t len = size;
875 size_t plen;
876
877 /* use the existing memory in an allocated page */
878 if (ctx->merge) {
879 sgl = list_entry(ctx->tsgl_list.prev,
880 struct af_alg_tsgl, list);
881 sg = sgl->sg + sgl->cur - 1;
882 len = min_t(size_t, len,
883 PAGE_SIZE - sg->offset - sg->length);
884
885 err = memcpy_from_msg(page_address(sg_page(sg)) +
886 sg->offset + sg->length,
887 msg, len);
888 if (err)
889 goto unlock;
890
891 sg->length += len;
892 ctx->merge = (sg->offset + sg->length) &
893 (PAGE_SIZE - 1);
894
895 ctx->used += len;
896 copied += len;
897 size -= len;
898 continue;
899 }
900
901 if (!af_alg_writable(sk)) {
902 err = af_alg_wait_for_wmem(sk, msg->msg_flags);
903 if (err)
904 goto unlock;
905 }
906
907 /* allocate a new page */
908 len = min_t(unsigned long, len, af_alg_sndbuf(sk));
909
910 err = af_alg_alloc_tsgl(sk);
911 if (err)
912 goto unlock;
913
914 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
915 list);
916 sg = sgl->sg;
917 if (sgl->cur)
918 sg_unmark_end(sg + sgl->cur - 1);
919
920 do {
921 unsigned int i = sgl->cur;
922
923 plen = min_t(size_t, len, PAGE_SIZE);
924
925 sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
926 if (!sg_page(sg + i)) {
927 err = -ENOMEM;
928 goto unlock;
929 }
930
931 err = memcpy_from_msg(page_address(sg_page(sg + i)),
932 msg, plen);
933 if (err) {
934 __free_page(sg_page(sg + i));
935 sg_assign_page(sg + i, NULL);
936 goto unlock;
937 }
938
939 sg[i].length = plen;
940 len -= plen;
941 ctx->used += plen;
942 copied += plen;
943 size -= plen;
944 sgl->cur++;
945 } while (len && sgl->cur < MAX_SGL_ENTS);
946
947 if (!size)
948 sg_mark_end(sg + sgl->cur - 1);
949
950 ctx->merge = plen & (PAGE_SIZE - 1);
951 }
952
953 err = 0;
954
955 ctx->more = msg->msg_flags & MSG_MORE;
956
957 unlock:
958 af_alg_data_wakeup(sk);
959 release_sock(sk);
960
961 return copied ?: err;
962 }
963 EXPORT_SYMBOL_GPL(af_alg_sendmsg);
964
965 /**
966 * af_alg_sendpage - sendpage system call handler
967 *
968 * This is a generic implementation of sendpage to fill ctx->tsgl_list.
969 */
970 ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
971 int offset, size_t size, int flags)
972 {
973 struct sock *sk = sock->sk;
974 struct alg_sock *ask = alg_sk(sk);
975 struct af_alg_ctx *ctx = ask->private;
976 struct af_alg_tsgl *sgl;
977 int err = -EINVAL;
978
979 if (flags & MSG_SENDPAGE_NOTLAST)
980 flags |= MSG_MORE;
981
982 lock_sock(sk);
983 if (!ctx->more && ctx->used)
984 goto unlock;
985
986 if (!size)
987 goto done;
988
989 if (!af_alg_writable(sk)) {
990 err = af_alg_wait_for_wmem(sk, flags);
991 if (err)
992 goto unlock;
993 }
994
995 err = af_alg_alloc_tsgl(sk);
996 if (err)
997 goto unlock;
998
999 ctx->merge = 0;
1000 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
1001
1002 if (sgl->cur)
1003 sg_unmark_end(sgl->sg + sgl->cur - 1);
1004
1005 sg_mark_end(sgl->sg + sgl->cur);
1006
1007 get_page(page);
1008 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
1009 sgl->cur++;
1010 ctx->used += size;
1011
1012 done:
1013 ctx->more = flags & MSG_MORE;
1014
1015 unlock:
1016 af_alg_data_wakeup(sk);
1017 release_sock(sk);
1018
1019 return err ?: size;
1020 }
1021 EXPORT_SYMBOL_GPL(af_alg_sendpage);
1022
1023 /**
1024 * af_alg_free_resources - release resources required for crypto request
1025 */
1026 void af_alg_free_resources(struct af_alg_async_req *areq)
1027 {
1028 struct sock *sk = areq->sk;
1029
1030 af_alg_free_areq_sgls(areq);
1031 sock_kfree_s(sk, areq, areq->areqlen);
1032 }
1033 EXPORT_SYMBOL_GPL(af_alg_free_resources);
1034
1035 /**
1036 * af_alg_async_cb - AIO callback handler
1037 *
1038 * This handler cleans up the struct af_alg_async_req upon completion of the
1039 * AIO operation.
1040 *
1041 * The number of bytes to be generated with the AIO operation must be set
1042 * in areq->outlen before the AIO callback handler is invoked.
1043 */
1044 void af_alg_async_cb(struct crypto_async_request *_req, int err)
1045 {
1046 struct af_alg_async_req *areq = _req->data;
1047 struct sock *sk = areq->sk;
1048 struct kiocb *iocb = areq->iocb;
1049 unsigned int resultlen;
1050
1051 /* Buffer size written by crypto operation. */
1052 resultlen = areq->outlen;
1053
1054 af_alg_free_resources(areq);
1055 sock_put(sk);
1056
1057 iocb->ki_complete(iocb, err ? err : resultlen, 0);
1058 }
1059 EXPORT_SYMBOL_GPL(af_alg_async_cb);
1060
1061 /**
1062 * af_alg_poll - poll system call handler
1063 */
1064 unsigned int af_alg_poll(struct file *file, struct socket *sock,
1065 poll_table *wait)
1066 {
1067 struct sock *sk = sock->sk;
1068 struct alg_sock *ask = alg_sk(sk);
1069 struct af_alg_ctx *ctx = ask->private;
1070 unsigned int mask;
1071
1072 sock_poll_wait(file, sk_sleep(sk), wait);
1073 mask = 0;
1074
1075 if (!ctx->more || ctx->used)
1076 mask |= POLLIN | POLLRDNORM;
1077
1078 if (af_alg_writable(sk))
1079 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
1080
1081 return mask;
1082 }
1083 EXPORT_SYMBOL_GPL(af_alg_poll);
1084
1085 /**
1086 * af_alg_alloc_areq - allocate struct af_alg_async_req
1087 *
1088 * @sk socket of connection to user space
1089 * @areqlen size of struct af_alg_async_req + crypto_*_reqsize
1090 * @return allocated data structure or ERR_PTR upon error
1091 */
1092 struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
1093 unsigned int areqlen)
1094 {
1095 struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
1096
1097 if (unlikely(!areq))
1098 return ERR_PTR(-ENOMEM);
1099
1100 areq->areqlen = areqlen;
1101 areq->sk = sk;
1102 areq->last_rsgl = NULL;
1103 INIT_LIST_HEAD(&areq->rsgl_list);
1104 areq->tsgl = NULL;
1105 areq->tsgl_entries = 0;
1106
1107 return areq;
1108 }
1109 EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
1110
1111 /**
1112 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1113 * operation
1114 *
1115 * @sk socket of connection to user space
1116 * @msg user space message
1117 * @flags flags used to invoke recvmsg with
1118 * @areq instance of the cryptographic request that will hold the RX SGL
1119 * @maxsize maximum number of bytes to be pulled from user space
1120 * @outlen number of bytes in the RX SGL
1121 * @return 0 on success, < 0 upon error
1122 */
1123 int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
1124 struct af_alg_async_req *areq, size_t maxsize,
1125 size_t *outlen)
1126 {
1127 struct alg_sock *ask = alg_sk(sk);
1128 struct af_alg_ctx *ctx = ask->private;
1129 size_t len = 0;
1130
1131 while (maxsize > len && msg_data_left(msg)) {
1132 struct af_alg_rsgl *rsgl;
1133 size_t seglen;
1134 int err;
1135
1136 /* limit the amount of readable buffers */
1137 if (!af_alg_readable(sk))
1138 break;
1139
1140 if (!ctx->used) {
1141 err = af_alg_wait_for_data(sk, flags);
1142 if (err)
1143 return err;
1144 }
1145
1146 seglen = min_t(size_t, (maxsize - len),
1147 msg_data_left(msg));
1148
1149 if (list_empty(&areq->rsgl_list)) {
1150 rsgl = &areq->first_rsgl;
1151 } else {
1152 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
1153 if (unlikely(!rsgl))
1154 return -ENOMEM;
1155 }
1156
1157 rsgl->sgl.npages = 0;
1158 list_add_tail(&rsgl->list, &areq->rsgl_list);
1159
1160 /* make one iovec available as scatterlist */
1161 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
1162 if (err < 0)
1163 return err;
1164
1165 /* chain the new scatterlist with previous one */
1166 if (areq->last_rsgl)
1167 af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
1168
1169 areq->last_rsgl = rsgl;
1170 len += err;
1171 ctx->rcvused += err;
1172 rsgl->sg_num_bytes = err;
1173 iov_iter_advance(&msg->msg_iter, err);
1174 }
1175
1176 *outlen = len;
1177 return 0;
1178 }
1179 EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
1180
1181 static int __init af_alg_init(void)
1182 {
1183 int err = proto_register(&alg_proto, 0);
1184
1185 if (err)
1186 goto out;
1187
1188 err = sock_register(&alg_family);
1189 if (err != 0)
1190 goto out_unregister_proto;
1191
1192 out:
1193 return err;
1194
1195 out_unregister_proto:
1196 proto_unregister(&alg_proto);
1197 goto out;
1198 }
1199
1200 static void __exit af_alg_exit(void)
1201 {
1202 sock_unregister(PF_ALG);
1203 proto_unregister(&alg_proto);
1204 }
1205
1206 module_init(af_alg_init);
1207 module_exit(af_alg_exit);
1208 MODULE_LICENSE("GPL");
1209 MODULE_ALIAS_NETPROTO(AF_ALG);
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