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