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Linux 4.14.51
[linux/fpc-iii.git] / crypto / af_alg.c
blob815ee1075574af7a03aca33b4d820e5bb4bbaa9b
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 sk2->sk_family = PF_ALG;
306
307 if (nokey || !ask->refcnt++)
308 sock_hold(sk);
309 ask->nokey_refcnt += nokey;
310 alg_sk(sk2)->parent = sk;
311 alg_sk(sk2)->type = type;
312 alg_sk(sk2)->nokey_refcnt = nokey;
313
314 newsock->ops = type->ops;
315 newsock->state = SS_CONNECTED;
316
317 if (nokey)
318 newsock->ops = type->ops_nokey;
319
320 err = 0;
321
322 unlock:
323 release_sock(sk);
324
325 return err;
326 }
327 EXPORT_SYMBOL_GPL(af_alg_accept);
328
329 static int alg_accept(struct socket *sock, struct socket *newsock, int flags,
330 bool kern)
331 {
332 return af_alg_accept(sock->sk, newsock, kern);
333 }
334
335 static const struct proto_ops alg_proto_ops = {
336 .family = PF_ALG,
337 .owner = THIS_MODULE,
338
339 .connect = sock_no_connect,
340 .socketpair = sock_no_socketpair,
341 .getname = sock_no_getname,
342 .ioctl = sock_no_ioctl,
343 .listen = sock_no_listen,
344 .shutdown = sock_no_shutdown,
345 .getsockopt = sock_no_getsockopt,
346 .mmap = sock_no_mmap,
347 .sendpage = sock_no_sendpage,
348 .sendmsg = sock_no_sendmsg,
349 .recvmsg = sock_no_recvmsg,
350 .poll = sock_no_poll,
351
352 .bind = alg_bind,
353 .release = af_alg_release,
354 .setsockopt = alg_setsockopt,
355 .accept = alg_accept,
356 };
357
358 static void alg_sock_destruct(struct sock *sk)
359 {
360 struct alg_sock *ask = alg_sk(sk);
361
362 alg_do_release(ask->type, ask->private);
363 }
364
365 static int alg_create(struct net *net, struct socket *sock, int protocol,
366 int kern)
367 {
368 struct sock *sk;
369 int err;
370
371 if (sock->type != SOCK_SEQPACKET)
372 return -ESOCKTNOSUPPORT;
373 if (protocol != 0)
374 return -EPROTONOSUPPORT;
375
376 err = -ENOMEM;
377 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
378 if (!sk)
379 goto out;
380
381 sock->ops = &alg_proto_ops;
382 sock_init_data(sock, sk);
383
384 sk->sk_family = PF_ALG;
385 sk->sk_destruct = alg_sock_destruct;
386
387 return 0;
388 out:
389 return err;
390 }
391
392 static const struct net_proto_family alg_family = {
393 .family = PF_ALG,
394 .create = alg_create,
395 .owner = THIS_MODULE,
396 };
397
398 int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
399 {
400 size_t off;
401 ssize_t n;
402 int npages, i;
403
404 n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
405 if (n < 0)
406 return n;
407
408 npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT;
409 if (WARN_ON(npages == 0))
410 return -EINVAL;
411 /* Add one extra for linking */
412 sg_init_table(sgl->sg, npages + 1);
413
414 for (i = 0, len = n; i < npages; i++) {
415 int plen = min_t(int, len, PAGE_SIZE - off);
416
417 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
418
419 off = 0;
420 len -= plen;
421 }
422 sg_mark_end(sgl->sg + npages - 1);
423 sgl->npages = npages;
424
425 return n;
426 }
427 EXPORT_SYMBOL_GPL(af_alg_make_sg);
428
429 void af_alg_link_sg(struct af_alg_sgl *sgl_prev, struct af_alg_sgl *sgl_new)
430 {
431 sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
432 sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
433 }
434 EXPORT_SYMBOL_GPL(af_alg_link_sg);
435
436 void af_alg_free_sg(struct af_alg_sgl *sgl)
437 {
438 int i;
439
440 for (i = 0; i < sgl->npages; i++)
441 put_page(sgl->pages[i]);
442 }
443 EXPORT_SYMBOL_GPL(af_alg_free_sg);
444
445 int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
446 {
447 struct cmsghdr *cmsg;
448
449 for_each_cmsghdr(cmsg, msg) {
450 if (!CMSG_OK(msg, cmsg))
451 return -EINVAL;
452 if (cmsg->cmsg_level != SOL_ALG)
453 continue;
454
455 switch (cmsg->cmsg_type) {
456 case ALG_SET_IV:
457 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
458 return -EINVAL;
459 con->iv = (void *)CMSG_DATA(cmsg);
460 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
461 sizeof(*con->iv)))
462 return -EINVAL;
463 break;
464
465 case ALG_SET_OP:
466 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
467 return -EINVAL;
468 con->op = *(u32 *)CMSG_DATA(cmsg);
469 break;
470
471 case ALG_SET_AEAD_ASSOCLEN:
472 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
473 return -EINVAL;
474 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
475 break;
476
477 default:
478 return -EINVAL;
479 }
480 }
481
482 return 0;
483 }
484 EXPORT_SYMBOL_GPL(af_alg_cmsg_send);
485
486 int af_alg_wait_for_completion(int err, struct af_alg_completion *completion)
487 {
488 switch (err) {
489 case -EINPROGRESS:
490 case -EBUSY:
491 wait_for_completion(&completion->completion);
492 reinit_completion(&completion->completion);
493 err = completion->err;
494 break;
495 };
496
497 return err;
498 }
499 EXPORT_SYMBOL_GPL(af_alg_wait_for_completion);
500
501 void af_alg_complete(struct crypto_async_request *req, int err)
502 {
503 struct af_alg_completion *completion = req->data;
504
505 if (err == -EINPROGRESS)
506 return;
507
508 completion->err = err;
509 complete(&completion->completion);
510 }
511 EXPORT_SYMBOL_GPL(af_alg_complete);
512
513 /**
514 * af_alg_alloc_tsgl - allocate the TX SGL
515 *
516 * @sk socket of connection to user space
517 * @return: 0 upon success, < 0 upon error
518 */
519 int af_alg_alloc_tsgl(struct sock *sk)
520 {
521 struct alg_sock *ask = alg_sk(sk);
522 struct af_alg_ctx *ctx = ask->private;
523 struct af_alg_tsgl *sgl;
524 struct scatterlist *sg = NULL;
525
526 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
527 if (!list_empty(&ctx->tsgl_list))
528 sg = sgl->sg;
529
530 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
531 sgl = sock_kmalloc(sk, sizeof(*sgl) +
532 sizeof(sgl->sg[0]) * (MAX_SGL_ENTS + 1),
533 GFP_KERNEL);
534 if (!sgl)
535 return -ENOMEM;
536
537 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
538 sgl->cur = 0;
539
540 if (sg)
541 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
542
543 list_add_tail(&sgl->list, &ctx->tsgl_list);
544 }
545
546 return 0;
547 }
548 EXPORT_SYMBOL_GPL(af_alg_alloc_tsgl);
549
550 /**
551 * aead_count_tsgl - Count number of TX SG entries
552 *
553 * The counting starts from the beginning of the SGL to @bytes. If
554 * an offset is provided, the counting of the SG entries starts at the offset.
555 *
556 * @sk socket of connection to user space
557 * @bytes Count the number of SG entries holding given number of bytes.
558 * @offset Start the counting of SG entries from the given offset.
559 * @return Number of TX SG entries found given the constraints
560 */
561 unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
562 {
563 struct alg_sock *ask = alg_sk(sk);
564 struct af_alg_ctx *ctx = ask->private;
565 struct af_alg_tsgl *sgl, *tmp;
566 unsigned int i;
567 unsigned int sgl_count = 0;
568
569 if (!bytes)
570 return 0;
571
572 list_for_each_entry_safe(sgl, tmp, &ctx->tsgl_list, list) {
573 struct scatterlist *sg = sgl->sg;
574
575 for (i = 0; i < sgl->cur; i++) {
576 size_t bytes_count;
577
578 /* Skip offset */
579 if (offset >= sg[i].length) {
580 offset -= sg[i].length;
581 bytes -= sg[i].length;
582 continue;
583 }
584
585 bytes_count = sg[i].length - offset;
586
587 offset = 0;
588 sgl_count++;
589
590 /* If we have seen requested number of bytes, stop */
591 if (bytes_count >= bytes)
592 return sgl_count;
593
594 bytes -= bytes_count;
595 }
596 }
597
598 return sgl_count;
599 }
600 EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
601
602 /**
603 * aead_pull_tsgl - Release the specified buffers from TX SGL
604 *
605 * If @dst is non-null, reassign the pages to dst. The caller must release
606 * the pages. If @dst_offset is given only reassign the pages to @dst starting
607 * at the @dst_offset (byte). The caller must ensure that @dst is large
608 * enough (e.g. by using af_alg_count_tsgl with the same offset).
609 *
610 * @sk socket of connection to user space
611 * @used Number of bytes to pull from TX SGL
612 * @dst If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
613 * caller must release the buffers in dst.
614 * @dst_offset Reassign the TX SGL from given offset. All buffers before
615 * reaching the offset is released.
616 */
617 void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
618 size_t dst_offset)
619 {
620 struct alg_sock *ask = alg_sk(sk);
621 struct af_alg_ctx *ctx = ask->private;
622 struct af_alg_tsgl *sgl;
623 struct scatterlist *sg;
624 unsigned int i, j = 0;
625
626 while (!list_empty(&ctx->tsgl_list)) {
627 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
628 list);
629 sg = sgl->sg;
630
631 for (i = 0; i < sgl->cur; i++) {
632 size_t plen = min_t(size_t, used, sg[i].length);
633 struct page *page = sg_page(sg + i);
634
635 if (!page)
636 continue;
637
638 /*
639 * Assumption: caller created af_alg_count_tsgl(len)
640 * SG entries in dst.
641 */
642 if (dst) {
643 if (dst_offset >= plen) {
644 /* discard page before offset */
645 dst_offset -= plen;
646 } else {
647 /* reassign page to dst after offset */
648 get_page(page);
649 sg_set_page(dst + j, page,
650 plen - dst_offset,
651 sg[i].offset + dst_offset);
652 dst_offset = 0;
653 j++;
654 }
655 }
656
657 sg[i].length -= plen;
658 sg[i].offset += plen;
659
660 used -= plen;
661 ctx->used -= plen;
662
663 if (sg[i].length)
664 return;
665
666 put_page(page);
667 sg_assign_page(sg + i, NULL);
668 }
669
670 list_del(&sgl->list);
671 sock_kfree_s(sk, sgl, sizeof(*sgl) + sizeof(sgl->sg[0]) *
672 (MAX_SGL_ENTS + 1));
673 }
674
675 if (!ctx->used)
676 ctx->merge = 0;
677 }
678 EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
679
680 /**
681 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
682 *
683 * @areq Request holding the TX and RX SGL
684 */
685 void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
686 {
687 struct sock *sk = areq->sk;
688 struct alg_sock *ask = alg_sk(sk);
689 struct af_alg_ctx *ctx = ask->private;
690 struct af_alg_rsgl *rsgl, *tmp;
691 struct scatterlist *tsgl;
692 struct scatterlist *sg;
693 unsigned int i;
694
695 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
696 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
697 af_alg_free_sg(&rsgl->sgl);
698 list_del(&rsgl->list);
699 if (rsgl != &areq->first_rsgl)
700 sock_kfree_s(sk, rsgl, sizeof(*rsgl));
701 }
702
703 tsgl = areq->tsgl;
704 if (tsgl) {
705 for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
706 if (!sg_page(sg))
707 continue;
708 put_page(sg_page(sg));
709 }
710
711 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
712 }
713 }
714 EXPORT_SYMBOL_GPL(af_alg_free_areq_sgls);
715
716 /**
717 * af_alg_wait_for_wmem - wait for availability of writable memory
718 *
719 * @sk socket of connection to user space
720 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
721 * @return 0 when writable memory is available, < 0 upon error
722 */
723 int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
724 {
725 DEFINE_WAIT_FUNC(wait, woken_wake_function);
726 int err = -ERESTARTSYS;
727 long timeout;
728
729 if (flags & MSG_DONTWAIT)
730 return -EAGAIN;
731
732 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
733
734 add_wait_queue(sk_sleep(sk), &wait);
735 for (;;) {
736 if (signal_pending(current))
737 break;
738 timeout = MAX_SCHEDULE_TIMEOUT;
739 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
740 err = 0;
741 break;
742 }
743 }
744 remove_wait_queue(sk_sleep(sk), &wait);
745
746 return err;
747 }
748 EXPORT_SYMBOL_GPL(af_alg_wait_for_wmem);
749
750 /**
751 * af_alg_wmem_wakeup - wakeup caller when writable memory is available
752 *
753 * @sk socket of connection to user space
754 */
755 void af_alg_wmem_wakeup(struct sock *sk)
756 {
757 struct socket_wq *wq;
758
759 if (!af_alg_writable(sk))
760 return;
761
762 rcu_read_lock();
763 wq = rcu_dereference(sk->sk_wq);
764 if (skwq_has_sleeper(wq))
765 wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
766 POLLRDNORM |
767 POLLRDBAND);
768 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
769 rcu_read_unlock();
770 }
771 EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
772
773 /**
774 * af_alg_wait_for_data - wait for availability of TX data
775 *
776 * @sk socket of connection to user space
777 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
778 * @return 0 when writable memory is available, < 0 upon error
779 */
780 int af_alg_wait_for_data(struct sock *sk, unsigned flags)
781 {
782 DEFINE_WAIT_FUNC(wait, woken_wake_function);
783 struct alg_sock *ask = alg_sk(sk);
784 struct af_alg_ctx *ctx = ask->private;
785 long timeout;
786 int err = -ERESTARTSYS;
787
788 if (flags & MSG_DONTWAIT)
789 return -EAGAIN;
790
791 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
792
793 add_wait_queue(sk_sleep(sk), &wait);
794 for (;;) {
795 if (signal_pending(current))
796 break;
797 timeout = MAX_SCHEDULE_TIMEOUT;
798 if (sk_wait_event(sk, &timeout, (ctx->used || !ctx->more),
799 &wait)) {
800 err = 0;
801 break;
802 }
803 }
804 remove_wait_queue(sk_sleep(sk), &wait);
805
806 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
807
808 return err;
809 }
810 EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
811
812 /**
813 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
814 *
815 * @sk socket of connection to user space
816 */
817
818 void af_alg_data_wakeup(struct sock *sk)
819 {
820 struct alg_sock *ask = alg_sk(sk);
821 struct af_alg_ctx *ctx = ask->private;
822 struct socket_wq *wq;
823
824 if (!ctx->used)
825 return;
826
827 rcu_read_lock();
828 wq = rcu_dereference(sk->sk_wq);
829 if (skwq_has_sleeper(wq))
830 wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
831 POLLRDNORM |
832 POLLRDBAND);
833 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
834 rcu_read_unlock();
835 }
836 EXPORT_SYMBOL_GPL(af_alg_data_wakeup);
837
838 /**
839 * af_alg_sendmsg - implementation of sendmsg system call handler
840 *
841 * The sendmsg system call handler obtains the user data and stores it
842 * in ctx->tsgl_list. This implies allocation of the required numbers of
843 * struct af_alg_tsgl.
844 *
845 * In addition, the ctx is filled with the information sent via CMSG.
846 *
847 * @sock socket of connection to user space
848 * @msg message from user space
849 * @size size of message from user space
850 * @ivsize the size of the IV for the cipher operation to verify that the
851 * user-space-provided IV has the right size
852 * @return the number of copied data upon success, < 0 upon error
853 */
854 int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
855 unsigned int ivsize)
856 {
857 struct sock *sk = sock->sk;
858 struct alg_sock *ask = alg_sk(sk);
859 struct af_alg_ctx *ctx = ask->private;
860 struct af_alg_tsgl *sgl;
861 struct af_alg_control con = {};
862 long copied = 0;
863 bool enc = 0;
864 bool init = 0;
865 int err = 0;
866
867 if (msg->msg_controllen) {
868 err = af_alg_cmsg_send(msg, &con);
869 if (err)
870 return err;
871
872 init = 1;
873 switch (con.op) {
874 case ALG_OP_ENCRYPT:
875 enc = 1;
876 break;
877 case ALG_OP_DECRYPT:
878 enc = 0;
879 break;
880 default:
881 return -EINVAL;
882 }
883
884 if (con.iv && con.iv->ivlen != ivsize)
885 return -EINVAL;
886 }
887
888 lock_sock(sk);
889 if (!ctx->more && ctx->used) {
890 err = -EINVAL;
891 goto unlock;
892 }
893
894 if (init) {
895 ctx->enc = enc;
896 if (con.iv)
897 memcpy(ctx->iv, con.iv->iv, ivsize);
898
899 ctx->aead_assoclen = con.aead_assoclen;
900 }
901
902 while (size) {
903 struct scatterlist *sg;
904 size_t len = size;
905 size_t plen;
906
907 /* use the existing memory in an allocated page */
908 if (ctx->merge) {
909 sgl = list_entry(ctx->tsgl_list.prev,
910 struct af_alg_tsgl, list);
911 sg = sgl->sg + sgl->cur - 1;
912 len = min_t(size_t, len,
913 PAGE_SIZE - sg->offset - sg->length);
914
915 err = memcpy_from_msg(page_address(sg_page(sg)) +
916 sg->offset + sg->length,
917 msg, len);
918 if (err)
919 goto unlock;
920
921 sg->length += len;
922 ctx->merge = (sg->offset + sg->length) &
923 (PAGE_SIZE - 1);
924
925 ctx->used += len;
926 copied += len;
927 size -= len;
928 continue;
929 }
930
931 if (!af_alg_writable(sk)) {
932 err = af_alg_wait_for_wmem(sk, msg->msg_flags);
933 if (err)
934 goto unlock;
935 }
936
937 /* allocate a new page */
938 len = min_t(unsigned long, len, af_alg_sndbuf(sk));
939
940 err = af_alg_alloc_tsgl(sk);
941 if (err)
942 goto unlock;
943
944 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
945 list);
946 sg = sgl->sg;
947 if (sgl->cur)
948 sg_unmark_end(sg + sgl->cur - 1);
949
950 do {
951 unsigned int i = sgl->cur;
952
953 plen = min_t(size_t, len, PAGE_SIZE);
954
955 sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
956 if (!sg_page(sg + i)) {
957 err = -ENOMEM;
958 goto unlock;
959 }
960
961 err = memcpy_from_msg(page_address(sg_page(sg + i)),
962 msg, plen);
963 if (err) {
964 __free_page(sg_page(sg + i));
965 sg_assign_page(sg + i, NULL);
966 goto unlock;
967 }
968
969 sg[i].length = plen;
970 len -= plen;
971 ctx->used += plen;
972 copied += plen;
973 size -= plen;
974 sgl->cur++;
975 } while (len && sgl->cur < MAX_SGL_ENTS);
976
977 if (!size)
978 sg_mark_end(sg + sgl->cur - 1);
979
980 ctx->merge = plen & (PAGE_SIZE - 1);
981 }
982
983 err = 0;
984
985 ctx->more = msg->msg_flags & MSG_MORE;
986
987 unlock:
988 af_alg_data_wakeup(sk);
989 release_sock(sk);
990
991 return copied ?: err;
992 }
993 EXPORT_SYMBOL_GPL(af_alg_sendmsg);
994
995 /**
996 * af_alg_sendpage - sendpage system call handler
997 *
998 * This is a generic implementation of sendpage to fill ctx->tsgl_list.
999 */
1000 ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
1001 int offset, size_t size, int flags)
1002 {
1003 struct sock *sk = sock->sk;
1004 struct alg_sock *ask = alg_sk(sk);
1005 struct af_alg_ctx *ctx = ask->private;
1006 struct af_alg_tsgl *sgl;
1007 int err = -EINVAL;
1008
1009 if (flags & MSG_SENDPAGE_NOTLAST)
1010 flags |= MSG_MORE;
1011
1012 lock_sock(sk);
1013 if (!ctx->more && ctx->used)
1014 goto unlock;
1015
1016 if (!size)
1017 goto done;
1018
1019 if (!af_alg_writable(sk)) {
1020 err = af_alg_wait_for_wmem(sk, flags);
1021 if (err)
1022 goto unlock;
1023 }
1024
1025 err = af_alg_alloc_tsgl(sk);
1026 if (err)
1027 goto unlock;
1028
1029 ctx->merge = 0;
1030 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
1031
1032 if (sgl->cur)
1033 sg_unmark_end(sgl->sg + sgl->cur - 1);
1034
1035 sg_mark_end(sgl->sg + sgl->cur);
1036
1037 get_page(page);
1038 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
1039 sgl->cur++;
1040 ctx->used += size;
1041
1042 done:
1043 ctx->more = flags & MSG_MORE;
1044
1045 unlock:
1046 af_alg_data_wakeup(sk);
1047 release_sock(sk);
1048
1049 return err ?: size;
1050 }
1051 EXPORT_SYMBOL_GPL(af_alg_sendpage);
1052
1053 /**
1054 * af_alg_free_resources - release resources required for crypto request
1055 */
1056 void af_alg_free_resources(struct af_alg_async_req *areq)
1057 {
1058 struct sock *sk = areq->sk;
1059
1060 af_alg_free_areq_sgls(areq);
1061 sock_kfree_s(sk, areq, areq->areqlen);
1062 }
1063 EXPORT_SYMBOL_GPL(af_alg_free_resources);
1064
1065 /**
1066 * af_alg_async_cb - AIO callback handler
1067 *
1068 * This handler cleans up the struct af_alg_async_req upon completion of the
1069 * AIO operation.
1070 *
1071 * The number of bytes to be generated with the AIO operation must be set
1072 * in areq->outlen before the AIO callback handler is invoked.
1073 */
1074 void af_alg_async_cb(struct crypto_async_request *_req, int err)
1075 {
1076 struct af_alg_async_req *areq = _req->data;
1077 struct sock *sk = areq->sk;
1078 struct kiocb *iocb = areq->iocb;
1079 unsigned int resultlen;
1080
1081 /* Buffer size written by crypto operation. */
1082 resultlen = areq->outlen;
1083
1084 af_alg_free_resources(areq);
1085 sock_put(sk);
1086
1087 iocb->ki_complete(iocb, err ? err : resultlen, 0);
1088 }
1089 EXPORT_SYMBOL_GPL(af_alg_async_cb);
1090
1091 /**
1092 * af_alg_poll - poll system call handler
1093 */
1094 unsigned int af_alg_poll(struct file *file, struct socket *sock,
1095 poll_table *wait)
1096 {
1097 struct sock *sk = sock->sk;
1098 struct alg_sock *ask = alg_sk(sk);
1099 struct af_alg_ctx *ctx = ask->private;
1100 unsigned int mask;
1101
1102 sock_poll_wait(file, sk_sleep(sk), wait);
1103 mask = 0;
1104
1105 if (!ctx->more || ctx->used)
1106 mask |= POLLIN | POLLRDNORM;
1107
1108 if (af_alg_writable(sk))
1109 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
1110
1111 return mask;
1112 }
1113 EXPORT_SYMBOL_GPL(af_alg_poll);
1114
1115 /**
1116 * af_alg_alloc_areq - allocate struct af_alg_async_req
1117 *
1118 * @sk socket of connection to user space
1119 * @areqlen size of struct af_alg_async_req + crypto_*_reqsize
1120 * @return allocated data structure or ERR_PTR upon error
1121 */
1122 struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
1123 unsigned int areqlen)
1124 {
1125 struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
1126
1127 if (unlikely(!areq))
1128 return ERR_PTR(-ENOMEM);
1129
1130 areq->areqlen = areqlen;
1131 areq->sk = sk;
1132 areq->last_rsgl = NULL;
1133 INIT_LIST_HEAD(&areq->rsgl_list);
1134 areq->tsgl = NULL;
1135 areq->tsgl_entries = 0;
1136
1137 return areq;
1138 }
1139 EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
1140
1141 /**
1142 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1143 * operation
1144 *
1145 * @sk socket of connection to user space
1146 * @msg user space message
1147 * @flags flags used to invoke recvmsg with
1148 * @areq instance of the cryptographic request that will hold the RX SGL
1149 * @maxsize maximum number of bytes to be pulled from user space
1150 * @outlen number of bytes in the RX SGL
1151 * @return 0 on success, < 0 upon error
1152 */
1153 int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
1154 struct af_alg_async_req *areq, size_t maxsize,
1155 size_t *outlen)
1156 {
1157 struct alg_sock *ask = alg_sk(sk);
1158 struct af_alg_ctx *ctx = ask->private;
1159 size_t len = 0;
1160
1161 while (maxsize > len && msg_data_left(msg)) {
1162 struct af_alg_rsgl *rsgl;
1163 size_t seglen;
1164 int err;
1165
1166 /* limit the amount of readable buffers */
1167 if (!af_alg_readable(sk))
1168 break;
1169
1170 seglen = min_t(size_t, (maxsize - len),
1171 msg_data_left(msg));
1172
1173 if (list_empty(&areq->rsgl_list)) {
1174 rsgl = &areq->first_rsgl;
1175 } else {
1176 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
1177 if (unlikely(!rsgl))
1178 return -ENOMEM;
1179 }
1180
1181 rsgl->sgl.npages = 0;
1182 list_add_tail(&rsgl->list, &areq->rsgl_list);
1183
1184 /* make one iovec available as scatterlist */
1185 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
1186 if (err < 0)
1187 return err;
1188
1189 /* chain the new scatterlist with previous one */
1190 if (areq->last_rsgl)
1191 af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
1192
1193 areq->last_rsgl = rsgl;
1194 len += err;
1195 atomic_add(err, &ctx->rcvused);
1196 rsgl->sg_num_bytes = err;
1197 iov_iter_advance(&msg->msg_iter, err);
1198 }
1199
1200 *outlen = len;
1201 return 0;
1202 }
1203 EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
1204
1205 static int __init af_alg_init(void)
1206 {
1207 int err = proto_register(&alg_proto, 0);
1208
1209 if (err)
1210 goto out;
1211
1212 err = sock_register(&alg_family);
1213 if (err != 0)
1214 goto out_unregister_proto;
1215
1216 out:
1217 return err;
1218
1219 out_unregister_proto:
1220 proto_unregister(&alg_proto);
1221 goto out;
1222 }
1223
1224 static void __exit af_alg_exit(void)
1225 {
1226 sock_unregister(PF_ALG);
1227 proto_unregister(&alg_proto);
1228 }
1229
1230 module_init(af_alg_init);
1231 module_exit(af_alg_exit);
1232 MODULE_LICENSE("GPL");
1233 MODULE_ALIAS_NETPROTO(AF_ALG);
Linux with added FPC-III support