?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Revert "locking/lockdep: Add debug_locks check in __lock_downgrade()"
[linux-stable.git] / crypto / af_alg.c
blobf816a72891046dc5bc819db3bdc14e75da5cb0a3
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 sock->sk = NULL;
128 }
129 return 0;
130 }
131 EXPORT_SYMBOL_GPL(af_alg_release);
132
133 void af_alg_release_parent(struct sock *sk)
134 {
135 struct alg_sock *ask = alg_sk(sk);
136 unsigned int nokey = ask->nokey_refcnt;
137 bool last = nokey && !ask->refcnt;
138
139 sk = ask->parent;
140 ask = alg_sk(sk);
141
142 lock_sock(sk);
143 ask->nokey_refcnt -= nokey;
144 if (!last)
145 last = !--ask->refcnt;
146 release_sock(sk);
147
148 if (last)
149 sock_put(sk);
150 }
151 EXPORT_SYMBOL_GPL(af_alg_release_parent);
152
153 static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
154 {
155 const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY;
156 struct sock *sk = sock->sk;
157 struct alg_sock *ask = alg_sk(sk);
158 struct sockaddr_alg *sa = (void *)uaddr;
159 const struct af_alg_type *type;
160 void *private;
161 int err;
162
163 if (sock->state == SS_CONNECTED)
164 return -EINVAL;
165
166 if (addr_len < sizeof(*sa))
167 return -EINVAL;
168
169 /* If caller uses non-allowed flag, return error. */
170 if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed))
171 return -EINVAL;
172
173 sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
174 sa->salg_name[sizeof(sa->salg_name) + addr_len - sizeof(*sa) - 1] = 0;
175
176 type = alg_get_type(sa->salg_type);
177 if (IS_ERR(type) && PTR_ERR(type) == -ENOENT) {
178 request_module("algif-%s", sa->salg_type);
179 type = alg_get_type(sa->salg_type);
180 }
181
182 if (IS_ERR(type))
183 return PTR_ERR(type);
184
185 private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask);
186 if (IS_ERR(private)) {
187 module_put(type->owner);
188 return PTR_ERR(private);
189 }
190
191 err = -EBUSY;
192 lock_sock(sk);
193 if (ask->refcnt | ask->nokey_refcnt)
194 goto unlock;
195
196 swap(ask->type, type);
197 swap(ask->private, private);
198
199 err = 0;
200
201 unlock:
202 release_sock(sk);
203
204 alg_do_release(type, private);
205
206 return err;
207 }
208
209 static int alg_setkey(struct sock *sk, char __user *ukey,
210 unsigned int keylen)
211 {
212 struct alg_sock *ask = alg_sk(sk);
213 const struct af_alg_type *type = ask->type;
214 u8 *key;
215 int err;
216
217 key = sock_kmalloc(sk, keylen, GFP_KERNEL);
218 if (!key)
219 return -ENOMEM;
220
221 err = -EFAULT;
222 if (copy_from_user(key, ukey, keylen))
223 goto out;
224
225 err = type->setkey(ask->private, key, keylen);
226
227 out:
228 sock_kzfree_s(sk, key, keylen);
229
230 return err;
231 }
232
233 static int alg_setsockopt(struct socket *sock, int level, int optname,
234 char __user *optval, unsigned int optlen)
235 {
236 struct sock *sk = sock->sk;
237 struct alg_sock *ask = alg_sk(sk);
238 const struct af_alg_type *type;
239 int err = -EBUSY;
240
241 lock_sock(sk);
242 if (ask->refcnt)
243 goto unlock;
244
245 type = ask->type;
246
247 err = -ENOPROTOOPT;
248 if (level != SOL_ALG || !type)
249 goto unlock;
250
251 switch (optname) {
252 case ALG_SET_KEY:
253 if (sock->state == SS_CONNECTED)
254 goto unlock;
255 if (!type->setkey)
256 goto unlock;
257
258 err = alg_setkey(sk, optval, optlen);
259 break;
260 case ALG_SET_AEAD_AUTHSIZE:
261 if (sock->state == SS_CONNECTED)
262 goto unlock;
263 if (!type->setauthsize)
264 goto unlock;
265 err = type->setauthsize(ask->private, optlen);
266 }
267
268 unlock:
269 release_sock(sk);
270
271 return err;
272 }
273
274 int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern)
275 {
276 struct alg_sock *ask = alg_sk(sk);
277 const struct af_alg_type *type;
278 struct sock *sk2;
279 unsigned int nokey;
280 int err;
281
282 lock_sock(sk);
283 type = ask->type;
284
285 err = -EINVAL;
286 if (!type)
287 goto unlock;
288
289 sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, kern);
290 err = -ENOMEM;
291 if (!sk2)
292 goto unlock;
293
294 sock_init_data(newsock, sk2);
295 security_sock_graft(sk2, newsock);
296 security_sk_clone(sk, sk2);
297
298 err = type->accept(ask->private, sk2);
299
300 nokey = err == -ENOKEY;
301 if (nokey && type->accept_nokey)
302 err = type->accept_nokey(ask->private, sk2);
303
304 if (err)
305 goto unlock;
306
307 sk2->sk_family = PF_ALG;
308
309 if (nokey || !ask->refcnt++)
310 sock_hold(sk);
311 ask->nokey_refcnt += nokey;
312 alg_sk(sk2)->parent = sk;
313 alg_sk(sk2)->type = type;
314 alg_sk(sk2)->nokey_refcnt = nokey;
315
316 newsock->ops = type->ops;
317 newsock->state = SS_CONNECTED;
318
319 if (nokey)
320 newsock->ops = type->ops_nokey;
321
322 err = 0;
323
324 unlock:
325 release_sock(sk);
326
327 return err;
328 }
329 EXPORT_SYMBOL_GPL(af_alg_accept);
330
331 static int alg_accept(struct socket *sock, struct socket *newsock, int flags,
332 bool kern)
333 {
334 return af_alg_accept(sock->sk, newsock, kern);
335 }
336
337 static const struct proto_ops alg_proto_ops = {
338 .family = PF_ALG,
339 .owner = THIS_MODULE,
340
341 .connect = sock_no_connect,
342 .socketpair = sock_no_socketpair,
343 .getname = sock_no_getname,
344 .ioctl = sock_no_ioctl,
345 .listen = sock_no_listen,
346 .shutdown = sock_no_shutdown,
347 .getsockopt = sock_no_getsockopt,
348 .mmap = sock_no_mmap,
349 .sendpage = sock_no_sendpage,
350 .sendmsg = sock_no_sendmsg,
351 .recvmsg = sock_no_recvmsg,
352 .poll = sock_no_poll,
353
354 .bind = alg_bind,
355 .release = af_alg_release,
356 .setsockopt = alg_setsockopt,
357 .accept = alg_accept,
358 };
359
360 static void alg_sock_destruct(struct sock *sk)
361 {
362 struct alg_sock *ask = alg_sk(sk);
363
364 alg_do_release(ask->type, ask->private);
365 }
366
367 static int alg_create(struct net *net, struct socket *sock, int protocol,
368 int kern)
369 {
370 struct sock *sk;
371 int err;
372
373 if (sock->type != SOCK_SEQPACKET)
374 return -ESOCKTNOSUPPORT;
375 if (protocol != 0)
376 return -EPROTONOSUPPORT;
377
378 err = -ENOMEM;
379 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
380 if (!sk)
381 goto out;
382
383 sock->ops = &alg_proto_ops;
384 sock_init_data(sock, sk);
385
386 sk->sk_family = PF_ALG;
387 sk->sk_destruct = alg_sock_destruct;
388
389 return 0;
390 out:
391 return err;
392 }
393
394 static const struct net_proto_family alg_family = {
395 .family = PF_ALG,
396 .create = alg_create,
397 .owner = THIS_MODULE,
398 };
399
400 int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
401 {
402 size_t off;
403 ssize_t n;
404 int npages, i;
405
406 n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
407 if (n < 0)
408 return n;
409
410 npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT;
411 if (WARN_ON(npages == 0))
412 return -EINVAL;
413 /* Add one extra for linking */
414 sg_init_table(sgl->sg, npages + 1);
415
416 for (i = 0, len = n; i < npages; i++) {
417 int plen = min_t(int, len, PAGE_SIZE - off);
418
419 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
420
421 off = 0;
422 len -= plen;
423 }
424 sg_mark_end(sgl->sg + npages - 1);
425 sgl->npages = npages;
426
427 return n;
428 }
429 EXPORT_SYMBOL_GPL(af_alg_make_sg);
430
431 void af_alg_link_sg(struct af_alg_sgl *sgl_prev, struct af_alg_sgl *sgl_new)
432 {
433 sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
434 sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
435 }
436 EXPORT_SYMBOL_GPL(af_alg_link_sg);
437
438 void af_alg_free_sg(struct af_alg_sgl *sgl)
439 {
440 int i;
441
442 for (i = 0; i < sgl->npages; i++)
443 put_page(sgl->pages[i]);
444 }
445 EXPORT_SYMBOL_GPL(af_alg_free_sg);
446
447 int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
448 {
449 struct cmsghdr *cmsg;
450
451 for_each_cmsghdr(cmsg, msg) {
452 if (!CMSG_OK(msg, cmsg))
453 return -EINVAL;
454 if (cmsg->cmsg_level != SOL_ALG)
455 continue;
456
457 switch (cmsg->cmsg_type) {
458 case ALG_SET_IV:
459 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
460 return -EINVAL;
461 con->iv = (void *)CMSG_DATA(cmsg);
462 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
463 sizeof(*con->iv)))
464 return -EINVAL;
465 break;
466
467 case ALG_SET_OP:
468 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
469 return -EINVAL;
470 con->op = *(u32 *)CMSG_DATA(cmsg);
471 break;
472
473 case ALG_SET_AEAD_ASSOCLEN:
474 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
475 return -EINVAL;
476 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
477 break;
478
479 default:
480 return -EINVAL;
481 }
482 }
483
484 return 0;
485 }
486 EXPORT_SYMBOL_GPL(af_alg_cmsg_send);
487
488 int af_alg_wait_for_completion(int err, struct af_alg_completion *completion)
489 {
490 switch (err) {
491 case -EINPROGRESS:
492 case -EBUSY:
493 wait_for_completion(&completion->completion);
494 reinit_completion(&completion->completion);
495 err = completion->err;
496 break;
497 };
498
499 return err;
500 }
501 EXPORT_SYMBOL_GPL(af_alg_wait_for_completion);
502
503 void af_alg_complete(struct crypto_async_request *req, int err)
504 {
505 struct af_alg_completion *completion = req->data;
506
507 if (err == -EINPROGRESS)
508 return;
509
510 completion->err = err;
511 complete(&completion->completion);
512 }
513 EXPORT_SYMBOL_GPL(af_alg_complete);
514
515 /**
516 * af_alg_alloc_tsgl - allocate the TX SGL
517 *
518 * @sk socket of connection to user space
519 * @return: 0 upon success, < 0 upon error
520 */
521 int af_alg_alloc_tsgl(struct sock *sk)
522 {
523 struct alg_sock *ask = alg_sk(sk);
524 struct af_alg_ctx *ctx = ask->private;
525 struct af_alg_tsgl *sgl;
526 struct scatterlist *sg = NULL;
527
528 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
529 if (!list_empty(&ctx->tsgl_list))
530 sg = sgl->sg;
531
532 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
533 sgl = sock_kmalloc(sk, sizeof(*sgl) +
534 sizeof(sgl->sg[0]) * (MAX_SGL_ENTS + 1),
535 GFP_KERNEL);
536 if (!sgl)
537 return -ENOMEM;
538
539 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
540 sgl->cur = 0;
541
542 if (sg)
543 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
544
545 list_add_tail(&sgl->list, &ctx->tsgl_list);
546 }
547
548 return 0;
549 }
550 EXPORT_SYMBOL_GPL(af_alg_alloc_tsgl);
551
552 /**
553 * aead_count_tsgl - Count number of TX SG entries
554 *
555 * The counting starts from the beginning of the SGL to @bytes. If
556 * an offset is provided, the counting of the SG entries starts at the offset.
557 *
558 * @sk socket of connection to user space
559 * @bytes Count the number of SG entries holding given number of bytes.
560 * @offset Start the counting of SG entries from the given offset.
561 * @return Number of TX SG entries found given the constraints
562 */
563 unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
564 {
565 struct alg_sock *ask = alg_sk(sk);
566 struct af_alg_ctx *ctx = ask->private;
567 struct af_alg_tsgl *sgl, *tmp;
568 unsigned int i;
569 unsigned int sgl_count = 0;
570
571 if (!bytes)
572 return 0;
573
574 list_for_each_entry_safe(sgl, tmp, &ctx->tsgl_list, list) {
575 struct scatterlist *sg = sgl->sg;
576
577 for (i = 0; i < sgl->cur; i++) {
578 size_t bytes_count;
579
580 /* Skip offset */
581 if (offset >= sg[i].length) {
582 offset -= sg[i].length;
583 bytes -= sg[i].length;
584 continue;
585 }
586
587 bytes_count = sg[i].length - offset;
588
589 offset = 0;
590 sgl_count++;
591
592 /* If we have seen requested number of bytes, stop */
593 if (bytes_count >= bytes)
594 return sgl_count;
595
596 bytes -= bytes_count;
597 }
598 }
599
600 return sgl_count;
601 }
602 EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
603
604 /**
605 * aead_pull_tsgl - Release the specified buffers from TX SGL
606 *
607 * If @dst is non-null, reassign the pages to dst. The caller must release
608 * the pages. If @dst_offset is given only reassign the pages to @dst starting
609 * at the @dst_offset (byte). The caller must ensure that @dst is large
610 * enough (e.g. by using af_alg_count_tsgl with the same offset).
611 *
612 * @sk socket of connection to user space
613 * @used Number of bytes to pull from TX SGL
614 * @dst If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
615 * caller must release the buffers in dst.
616 * @dst_offset Reassign the TX SGL from given offset. All buffers before
617 * reaching the offset is released.
618 */
619 void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
620 size_t dst_offset)
621 {
622 struct alg_sock *ask = alg_sk(sk);
623 struct af_alg_ctx *ctx = ask->private;
624 struct af_alg_tsgl *sgl;
625 struct scatterlist *sg;
626 unsigned int i, j = 0;
627
628 while (!list_empty(&ctx->tsgl_list)) {
629 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
630 list);
631 sg = sgl->sg;
632
633 for (i = 0; i < sgl->cur; i++) {
634 size_t plen = min_t(size_t, used, sg[i].length);
635 struct page *page = sg_page(sg + i);
636
637 if (!page)
638 continue;
639
640 /*
641 * Assumption: caller created af_alg_count_tsgl(len)
642 * SG entries in dst.
643 */
644 if (dst) {
645 if (dst_offset >= plen) {
646 /* discard page before offset */
647 dst_offset -= plen;
648 } else {
649 /* reassign page to dst after offset */
650 get_page(page);
651 sg_set_page(dst + j, page,
652 plen - dst_offset,
653 sg[i].offset + dst_offset);
654 dst_offset = 0;
655 j++;
656 }
657 }
658
659 sg[i].length -= plen;
660 sg[i].offset += plen;
661
662 used -= plen;
663 ctx->used -= plen;
664
665 if (sg[i].length)
666 return;
667
668 put_page(page);
669 sg_assign_page(sg + i, NULL);
670 }
671
672 list_del(&sgl->list);
673 sock_kfree_s(sk, sgl, sizeof(*sgl) + sizeof(sgl->sg[0]) *
674 (MAX_SGL_ENTS + 1));
675 }
676
677 if (!ctx->used)
678 ctx->merge = 0;
679 }
680 EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
681
682 /**
683 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
684 *
685 * @areq Request holding the TX and RX SGL
686 */
687 void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
688 {
689 struct sock *sk = areq->sk;
690 struct alg_sock *ask = alg_sk(sk);
691 struct af_alg_ctx *ctx = ask->private;
692 struct af_alg_rsgl *rsgl, *tmp;
693 struct scatterlist *tsgl;
694 struct scatterlist *sg;
695 unsigned int i;
696
697 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
698 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
699 af_alg_free_sg(&rsgl->sgl);
700 list_del(&rsgl->list);
701 if (rsgl != &areq->first_rsgl)
702 sock_kfree_s(sk, rsgl, sizeof(*rsgl));
703 }
704
705 tsgl = areq->tsgl;
706 if (tsgl) {
707 for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
708 if (!sg_page(sg))
709 continue;
710 put_page(sg_page(sg));
711 }
712
713 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
714 }
715 }
716 EXPORT_SYMBOL_GPL(af_alg_free_areq_sgls);
717
718 /**
719 * af_alg_wait_for_wmem - wait for availability of writable memory
720 *
721 * @sk socket of connection to user space
722 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
723 * @return 0 when writable memory is available, < 0 upon error
724 */
725 int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
726 {
727 DEFINE_WAIT_FUNC(wait, woken_wake_function);
728 int err = -ERESTARTSYS;
729 long timeout;
730
731 if (flags & MSG_DONTWAIT)
732 return -EAGAIN;
733
734 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
735
736 add_wait_queue(sk_sleep(sk), &wait);
737 for (;;) {
738 if (signal_pending(current))
739 break;
740 timeout = MAX_SCHEDULE_TIMEOUT;
741 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
742 err = 0;
743 break;
744 }
745 }
746 remove_wait_queue(sk_sleep(sk), &wait);
747
748 return err;
749 }
750 EXPORT_SYMBOL_GPL(af_alg_wait_for_wmem);
751
752 /**
753 * af_alg_wmem_wakeup - wakeup caller when writable memory is available
754 *
755 * @sk socket of connection to user space
756 */
757 void af_alg_wmem_wakeup(struct sock *sk)
758 {
759 struct socket_wq *wq;
760
761 if (!af_alg_writable(sk))
762 return;
763
764 rcu_read_lock();
765 wq = rcu_dereference(sk->sk_wq);
766 if (skwq_has_sleeper(wq))
767 wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
768 POLLRDNORM |
769 POLLRDBAND);
770 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
771 rcu_read_unlock();
772 }
773 EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
774
775 /**
776 * af_alg_wait_for_data - wait for availability of TX data
777 *
778 * @sk socket of connection to user space
779 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
780 * @return 0 when writable memory is available, < 0 upon error
781 */
782 int af_alg_wait_for_data(struct sock *sk, unsigned flags)
783 {
784 DEFINE_WAIT_FUNC(wait, woken_wake_function);
785 struct alg_sock *ask = alg_sk(sk);
786 struct af_alg_ctx *ctx = ask->private;
787 long timeout;
788 int err = -ERESTARTSYS;
789
790 if (flags & MSG_DONTWAIT)
791 return -EAGAIN;
792
793 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
794
795 add_wait_queue(sk_sleep(sk), &wait);
796 for (;;) {
797 if (signal_pending(current))
798 break;
799 timeout = MAX_SCHEDULE_TIMEOUT;
800 if (sk_wait_event(sk, &timeout, (ctx->used || !ctx->more),
801 &wait)) {
802 err = 0;
803 break;
804 }
805 }
806 remove_wait_queue(sk_sleep(sk), &wait);
807
808 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
809
810 return err;
811 }
812 EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
813
814 /**
815 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
816 *
817 * @sk socket of connection to user space
818 */
819
820 void af_alg_data_wakeup(struct sock *sk)
821 {
822 struct alg_sock *ask = alg_sk(sk);
823 struct af_alg_ctx *ctx = ask->private;
824 struct socket_wq *wq;
825
826 if (!ctx->used)
827 return;
828
829 rcu_read_lock();
830 wq = rcu_dereference(sk->sk_wq);
831 if (skwq_has_sleeper(wq))
832 wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
833 POLLRDNORM |
834 POLLRDBAND);
835 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
836 rcu_read_unlock();
837 }
838 EXPORT_SYMBOL_GPL(af_alg_data_wakeup);
839
840 /**
841 * af_alg_sendmsg - implementation of sendmsg system call handler
842 *
843 * The sendmsg system call handler obtains the user data and stores it
844 * in ctx->tsgl_list. This implies allocation of the required numbers of
845 * struct af_alg_tsgl.
846 *
847 * In addition, the ctx is filled with the information sent via CMSG.
848 *
849 * @sock socket of connection to user space
850 * @msg message from user space
851 * @size size of message from user space
852 * @ivsize the size of the IV for the cipher operation to verify that the
853 * user-space-provided IV has the right size
854 * @return the number of copied data upon success, < 0 upon error
855 */
856 int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
857 unsigned int ivsize)
858 {
859 struct sock *sk = sock->sk;
860 struct alg_sock *ask = alg_sk(sk);
861 struct af_alg_ctx *ctx = ask->private;
862 struct af_alg_tsgl *sgl;
863 struct af_alg_control con = {};
864 long copied = 0;
865 bool enc = 0;
866 bool init = 0;
867 int err = 0;
868
869 if (msg->msg_controllen) {
870 err = af_alg_cmsg_send(msg, &con);
871 if (err)
872 return err;
873
874 init = 1;
875 switch (con.op) {
876 case ALG_OP_ENCRYPT:
877 enc = 1;
878 break;
879 case ALG_OP_DECRYPT:
880 enc = 0;
881 break;
882 default:
883 return -EINVAL;
884 }
885
886 if (con.iv && con.iv->ivlen != ivsize)
887 return -EINVAL;
888 }
889
890 lock_sock(sk);
891 if (!ctx->more && ctx->used) {
892 err = -EINVAL;
893 goto unlock;
894 }
895
896 if (init) {
897 ctx->enc = enc;
898 if (con.iv)
899 memcpy(ctx->iv, con.iv->iv, ivsize);
900
901 ctx->aead_assoclen = con.aead_assoclen;
902 }
903
904 while (size) {
905 struct scatterlist *sg;
906 size_t len = size;
907 size_t plen;
908
909 /* use the existing memory in an allocated page */
910 if (ctx->merge) {
911 sgl = list_entry(ctx->tsgl_list.prev,
912 struct af_alg_tsgl, list);
913 sg = sgl->sg + sgl->cur - 1;
914 len = min_t(size_t, len,
915 PAGE_SIZE - sg->offset - sg->length);
916
917 err = memcpy_from_msg(page_address(sg_page(sg)) +
918 sg->offset + sg->length,
919 msg, len);
920 if (err)
921 goto unlock;
922
923 sg->length += len;
924 ctx->merge = (sg->offset + sg->length) &
925 (PAGE_SIZE - 1);
926
927 ctx->used += len;
928 copied += len;
929 size -= len;
930 continue;
931 }
932
933 if (!af_alg_writable(sk)) {
934 err = af_alg_wait_for_wmem(sk, msg->msg_flags);
935 if (err)
936 goto unlock;
937 }
938
939 /* allocate a new page */
940 len = min_t(unsigned long, len, af_alg_sndbuf(sk));
941
942 err = af_alg_alloc_tsgl(sk);
943 if (err)
944 goto unlock;
945
946 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
947 list);
948 sg = sgl->sg;
949 if (sgl->cur)
950 sg_unmark_end(sg + sgl->cur - 1);
951
952 do {
953 unsigned int i = sgl->cur;
954
955 plen = min_t(size_t, len, PAGE_SIZE);
956
957 sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
958 if (!sg_page(sg + i)) {
959 err = -ENOMEM;
960 goto unlock;
961 }
962
963 err = memcpy_from_msg(page_address(sg_page(sg + i)),
964 msg, plen);
965 if (err) {
966 __free_page(sg_page(sg + i));
967 sg_assign_page(sg + i, NULL);
968 goto unlock;
969 }
970
971 sg[i].length = plen;
972 len -= plen;
973 ctx->used += plen;
974 copied += plen;
975 size -= plen;
976 sgl->cur++;
977 } while (len && sgl->cur < MAX_SGL_ENTS);
978
979 if (!size)
980 sg_mark_end(sg + sgl->cur - 1);
981
982 ctx->merge = plen & (PAGE_SIZE - 1);
983 }
984
985 err = 0;
986
987 ctx->more = msg->msg_flags & MSG_MORE;
988
989 unlock:
990 af_alg_data_wakeup(sk);
991 release_sock(sk);
992
993 return copied ?: err;
994 }
995 EXPORT_SYMBOL_GPL(af_alg_sendmsg);
996
997 /**
998 * af_alg_sendpage - sendpage system call handler
999 *
1000 * This is a generic implementation of sendpage to fill ctx->tsgl_list.
1001 */
1002 ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
1003 int offset, size_t size, int flags)
1004 {
1005 struct sock *sk = sock->sk;
1006 struct alg_sock *ask = alg_sk(sk);
1007 struct af_alg_ctx *ctx = ask->private;
1008 struct af_alg_tsgl *sgl;
1009 int err = -EINVAL;
1010
1011 if (flags & MSG_SENDPAGE_NOTLAST)
1012 flags |= MSG_MORE;
1013
1014 lock_sock(sk);
1015 if (!ctx->more && ctx->used)
1016 goto unlock;
1017
1018 if (!size)
1019 goto done;
1020
1021 if (!af_alg_writable(sk)) {
1022 err = af_alg_wait_for_wmem(sk, flags);
1023 if (err)
1024 goto unlock;
1025 }
1026
1027 err = af_alg_alloc_tsgl(sk);
1028 if (err)
1029 goto unlock;
1030
1031 ctx->merge = 0;
1032 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
1033
1034 if (sgl->cur)
1035 sg_unmark_end(sgl->sg + sgl->cur - 1);
1036
1037 sg_mark_end(sgl->sg + sgl->cur);
1038
1039 get_page(page);
1040 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
1041 sgl->cur++;
1042 ctx->used += size;
1043
1044 done:
1045 ctx->more = flags & MSG_MORE;
1046
1047 unlock:
1048 af_alg_data_wakeup(sk);
1049 release_sock(sk);
1050
1051 return err ?: size;
1052 }
1053 EXPORT_SYMBOL_GPL(af_alg_sendpage);
1054
1055 /**
1056 * af_alg_free_resources - release resources required for crypto request
1057 */
1058 void af_alg_free_resources(struct af_alg_async_req *areq)
1059 {
1060 struct sock *sk = areq->sk;
1061
1062 af_alg_free_areq_sgls(areq);
1063 sock_kfree_s(sk, areq, areq->areqlen);
1064 }
1065 EXPORT_SYMBOL_GPL(af_alg_free_resources);
1066
1067 /**
1068 * af_alg_async_cb - AIO callback handler
1069 *
1070 * This handler cleans up the struct af_alg_async_req upon completion of the
1071 * AIO operation.
1072 *
1073 * The number of bytes to be generated with the AIO operation must be set
1074 * in areq->outlen before the AIO callback handler is invoked.
1075 */
1076 void af_alg_async_cb(struct crypto_async_request *_req, int err)
1077 {
1078 struct af_alg_async_req *areq = _req->data;
1079 struct sock *sk = areq->sk;
1080 struct kiocb *iocb = areq->iocb;
1081 unsigned int resultlen;
1082
1083 /* Buffer size written by crypto operation. */
1084 resultlen = areq->outlen;
1085
1086 af_alg_free_resources(areq);
1087 sock_put(sk);
1088
1089 iocb->ki_complete(iocb, err ? err : resultlen, 0);
1090 }
1091 EXPORT_SYMBOL_GPL(af_alg_async_cb);
1092
1093 /**
1094 * af_alg_poll - poll system call handler
1095 */
1096 unsigned int af_alg_poll(struct file *file, struct socket *sock,
1097 poll_table *wait)
1098 {
1099 struct sock *sk = sock->sk;
1100 struct alg_sock *ask = alg_sk(sk);
1101 struct af_alg_ctx *ctx = ask->private;
1102 unsigned int mask;
1103
1104 sock_poll_wait(file, sk_sleep(sk), wait);
1105 mask = 0;
1106
1107 if (!ctx->more || ctx->used)
1108 mask |= POLLIN | POLLRDNORM;
1109
1110 if (af_alg_writable(sk))
1111 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
1112
1113 return mask;
1114 }
1115 EXPORT_SYMBOL_GPL(af_alg_poll);
1116
1117 /**
1118 * af_alg_alloc_areq - allocate struct af_alg_async_req
1119 *
1120 * @sk socket of connection to user space
1121 * @areqlen size of struct af_alg_async_req + crypto_*_reqsize
1122 * @return allocated data structure or ERR_PTR upon error
1123 */
1124 struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
1125 unsigned int areqlen)
1126 {
1127 struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
1128
1129 if (unlikely(!areq))
1130 return ERR_PTR(-ENOMEM);
1131
1132 areq->areqlen = areqlen;
1133 areq->sk = sk;
1134 areq->last_rsgl = NULL;
1135 INIT_LIST_HEAD(&areq->rsgl_list);
1136 areq->tsgl = NULL;
1137 areq->tsgl_entries = 0;
1138
1139 return areq;
1140 }
1141 EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
1142
1143 /**
1144 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1145 * operation
1146 *
1147 * @sk socket of connection to user space
1148 * @msg user space message
1149 * @flags flags used to invoke recvmsg with
1150 * @areq instance of the cryptographic request that will hold the RX SGL
1151 * @maxsize maximum number of bytes to be pulled from user space
1152 * @outlen number of bytes in the RX SGL
1153 * @return 0 on success, < 0 upon error
1154 */
1155 int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
1156 struct af_alg_async_req *areq, size_t maxsize,
1157 size_t *outlen)
1158 {
1159 struct alg_sock *ask = alg_sk(sk);
1160 struct af_alg_ctx *ctx = ask->private;
1161 size_t len = 0;
1162
1163 while (maxsize > len && msg_data_left(msg)) {
1164 struct af_alg_rsgl *rsgl;
1165 size_t seglen;
1166 int err;
1167
1168 /* limit the amount of readable buffers */
1169 if (!af_alg_readable(sk))
1170 break;
1171
1172 seglen = min_t(size_t, (maxsize - len),
1173 msg_data_left(msg));
1174
1175 if (list_empty(&areq->rsgl_list)) {
1176 rsgl = &areq->first_rsgl;
1177 } else {
1178 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
1179 if (unlikely(!rsgl))
1180 return -ENOMEM;
1181 }
1182
1183 rsgl->sgl.npages = 0;
1184 list_add_tail(&rsgl->list, &areq->rsgl_list);
1185
1186 /* make one iovec available as scatterlist */
1187 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
1188 if (err < 0) {
1189 rsgl->sg_num_bytes = 0;
1190 return err;
1191 }
1192
1193 /* chain the new scatterlist with previous one */
1194 if (areq->last_rsgl)
1195 af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
1196
1197 areq->last_rsgl = rsgl;
1198 len += err;
1199 atomic_add(err, &ctx->rcvused);
1200 rsgl->sg_num_bytes = err;
1201 iov_iter_advance(&msg->msg_iter, err);
1202 }
1203
1204 *outlen = len;
1205 return 0;
1206 }
1207 EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
1208
1209 static int __init af_alg_init(void)
1210 {
1211 int err = proto_register(&alg_proto, 0);
1212
1213 if (err)
1214 goto out;
1215
1216 err = sock_register(&alg_family);
1217 if (err != 0)
1218 goto out_unregister_proto;
1219
1220 out:
1221 return err;
1222
1223 out_unregister_proto:
1224 proto_unregister(&alg_proto);
1225 goto out;
1226 }
1227
1228 static void __exit af_alg_exit(void)
1229 {
1230 sock_unregister(PF_ALG);
1231 proto_unregister(&alg_proto);
1232 }
1233
1234 module_init(af_alg_init);
1235 module_exit(af_alg_exit);
1236 MODULE_LICENSE("GPL");
1237 MODULE_ALIAS_NETPROTO(AF_ALG);
Linux kernel stable tree