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mm/vmscan.c: prevent useless kswapd loops
[linux/fpc-iii.git] / crypto / af_alg.c
blobec78a04eb136e8bfd31e9ce3ab2d1b0a7ed29be1
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
353 .bind = alg_bind,
354 .release = af_alg_release,
355 .setsockopt = alg_setsockopt,
356 .accept = alg_accept,
357 };
358
359 static void alg_sock_destruct(struct sock *sk)
360 {
361 struct alg_sock *ask = alg_sk(sk);
362
363 alg_do_release(ask->type, ask->private);
364 }
365
366 static int alg_create(struct net *net, struct socket *sock, int protocol,
367 int kern)
368 {
369 struct sock *sk;
370 int err;
371
372 if (sock->type != SOCK_SEQPACKET)
373 return -ESOCKTNOSUPPORT;
374 if (protocol != 0)
375 return -EPROTONOSUPPORT;
376
377 err = -ENOMEM;
378 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
379 if (!sk)
380 goto out;
381
382 sock->ops = &alg_proto_ops;
383 sock_init_data(sock, sk);
384
385 sk->sk_family = PF_ALG;
386 sk->sk_destruct = alg_sock_destruct;
387
388 return 0;
389 out:
390 return err;
391 }
392
393 static const struct net_proto_family alg_family = {
394 .family = PF_ALG,
395 .create = alg_create,
396 .owner = THIS_MODULE,
397 };
398
399 int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
400 {
401 size_t off;
402 ssize_t n;
403 int npages, i;
404
405 n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
406 if (n < 0)
407 return n;
408
409 npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT;
410 if (WARN_ON(npages == 0))
411 return -EINVAL;
412 /* Add one extra for linking */
413 sg_init_table(sgl->sg, npages + 1);
414
415 for (i = 0, len = n; i < npages; i++) {
416 int plen = min_t(int, len, PAGE_SIZE - off);
417
418 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
419
420 off = 0;
421 len -= plen;
422 }
423 sg_mark_end(sgl->sg + npages - 1);
424 sgl->npages = npages;
425
426 return n;
427 }
428 EXPORT_SYMBOL_GPL(af_alg_make_sg);
429
430 void af_alg_link_sg(struct af_alg_sgl *sgl_prev, struct af_alg_sgl *sgl_new)
431 {
432 sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
433 sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
434 }
435 EXPORT_SYMBOL_GPL(af_alg_link_sg);
436
437 void af_alg_free_sg(struct af_alg_sgl *sgl)
438 {
439 int i;
440
441 for (i = 0; i < sgl->npages; i++)
442 put_page(sgl->pages[i]);
443 }
444 EXPORT_SYMBOL_GPL(af_alg_free_sg);
445
446 int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
447 {
448 struct cmsghdr *cmsg;
449
450 for_each_cmsghdr(cmsg, msg) {
451 if (!CMSG_OK(msg, cmsg))
452 return -EINVAL;
453 if (cmsg->cmsg_level != SOL_ALG)
454 continue;
455
456 switch (cmsg->cmsg_type) {
457 case ALG_SET_IV:
458 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
459 return -EINVAL;
460 con->iv = (void *)CMSG_DATA(cmsg);
461 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
462 sizeof(*con->iv)))
463 return -EINVAL;
464 break;
465
466 case ALG_SET_OP:
467 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
468 return -EINVAL;
469 con->op = *(u32 *)CMSG_DATA(cmsg);
470 break;
471
472 case ALG_SET_AEAD_ASSOCLEN:
473 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
474 return -EINVAL;
475 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
476 break;
477
478 default:
479 return -EINVAL;
480 }
481 }
482
483 return 0;
484 }
485 EXPORT_SYMBOL_GPL(af_alg_cmsg_send);
486
487 /**
488 * af_alg_alloc_tsgl - allocate the TX SGL
489 *
490 * @sk socket of connection to user space
491 * @return: 0 upon success, < 0 upon error
492 */
493 int af_alg_alloc_tsgl(struct sock *sk)
494 {
495 struct alg_sock *ask = alg_sk(sk);
496 struct af_alg_ctx *ctx = ask->private;
497 struct af_alg_tsgl *sgl;
498 struct scatterlist *sg = NULL;
499
500 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
501 if (!list_empty(&ctx->tsgl_list))
502 sg = sgl->sg;
503
504 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
505 sgl = sock_kmalloc(sk,
506 struct_size(sgl, sg, (MAX_SGL_ENTS + 1)),
507 GFP_KERNEL);
508 if (!sgl)
509 return -ENOMEM;
510
511 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
512 sgl->cur = 0;
513
514 if (sg)
515 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
516
517 list_add_tail(&sgl->list, &ctx->tsgl_list);
518 }
519
520 return 0;
521 }
522 EXPORT_SYMBOL_GPL(af_alg_alloc_tsgl);
523
524 /**
525 * aead_count_tsgl - Count number of TX SG entries
526 *
527 * The counting starts from the beginning of the SGL to @bytes. If
528 * an offset is provided, the counting of the SG entries starts at the offset.
529 *
530 * @sk socket of connection to user space
531 * @bytes Count the number of SG entries holding given number of bytes.
532 * @offset Start the counting of SG entries from the given offset.
533 * @return Number of TX SG entries found given the constraints
534 */
535 unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
536 {
537 struct alg_sock *ask = alg_sk(sk);
538 struct af_alg_ctx *ctx = ask->private;
539 struct af_alg_tsgl *sgl, *tmp;
540 unsigned int i;
541 unsigned int sgl_count = 0;
542
543 if (!bytes)
544 return 0;
545
546 list_for_each_entry_safe(sgl, tmp, &ctx->tsgl_list, list) {
547 struct scatterlist *sg = sgl->sg;
548
549 for (i = 0; i < sgl->cur; i++) {
550 size_t bytes_count;
551
552 /* Skip offset */
553 if (offset >= sg[i].length) {
554 offset -= sg[i].length;
555 bytes -= sg[i].length;
556 continue;
557 }
558
559 bytes_count = sg[i].length - offset;
560
561 offset = 0;
562 sgl_count++;
563
564 /* If we have seen requested number of bytes, stop */
565 if (bytes_count >= bytes)
566 return sgl_count;
567
568 bytes -= bytes_count;
569 }
570 }
571
572 return sgl_count;
573 }
574 EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
575
576 /**
577 * aead_pull_tsgl - Release the specified buffers from TX SGL
578 *
579 * If @dst is non-null, reassign the pages to dst. The caller must release
580 * the pages. If @dst_offset is given only reassign the pages to @dst starting
581 * at the @dst_offset (byte). The caller must ensure that @dst is large
582 * enough (e.g. by using af_alg_count_tsgl with the same offset).
583 *
584 * @sk socket of connection to user space
585 * @used Number of bytes to pull from TX SGL
586 * @dst If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
587 * caller must release the buffers in dst.
588 * @dst_offset Reassign the TX SGL from given offset. All buffers before
589 * reaching the offset is released.
590 */
591 void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
592 size_t dst_offset)
593 {
594 struct alg_sock *ask = alg_sk(sk);
595 struct af_alg_ctx *ctx = ask->private;
596 struct af_alg_tsgl *sgl;
597 struct scatterlist *sg;
598 unsigned int i, j = 0;
599
600 while (!list_empty(&ctx->tsgl_list)) {
601 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
602 list);
603 sg = sgl->sg;
604
605 for (i = 0; i < sgl->cur; i++) {
606 size_t plen = min_t(size_t, used, sg[i].length);
607 struct page *page = sg_page(sg + i);
608
609 if (!page)
610 continue;
611
612 /*
613 * Assumption: caller created af_alg_count_tsgl(len)
614 * SG entries in dst.
615 */
616 if (dst) {
617 if (dst_offset >= plen) {
618 /* discard page before offset */
619 dst_offset -= plen;
620 } else {
621 /* reassign page to dst after offset */
622 get_page(page);
623 sg_set_page(dst + j, page,
624 plen - dst_offset,
625 sg[i].offset + dst_offset);
626 dst_offset = 0;
627 j++;
628 }
629 }
630
631 sg[i].length -= plen;
632 sg[i].offset += plen;
633
634 used -= plen;
635 ctx->used -= plen;
636
637 if (sg[i].length)
638 return;
639
640 put_page(page);
641 sg_assign_page(sg + i, NULL);
642 }
643
644 list_del(&sgl->list);
645 sock_kfree_s(sk, sgl, sizeof(*sgl) + sizeof(sgl->sg[0]) *
646 (MAX_SGL_ENTS + 1));
647 }
648
649 if (!ctx->used)
650 ctx->merge = 0;
651 }
652 EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
653
654 /**
655 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
656 *
657 * @areq Request holding the TX and RX SGL
658 */
659 void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
660 {
661 struct sock *sk = areq->sk;
662 struct alg_sock *ask = alg_sk(sk);
663 struct af_alg_ctx *ctx = ask->private;
664 struct af_alg_rsgl *rsgl, *tmp;
665 struct scatterlist *tsgl;
666 struct scatterlist *sg;
667 unsigned int i;
668
669 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
670 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
671 af_alg_free_sg(&rsgl->sgl);
672 list_del(&rsgl->list);
673 if (rsgl != &areq->first_rsgl)
674 sock_kfree_s(sk, rsgl, sizeof(*rsgl));
675 }
676
677 tsgl = areq->tsgl;
678 if (tsgl) {
679 for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
680 if (!sg_page(sg))
681 continue;
682 put_page(sg_page(sg));
683 }
684
685 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
686 }
687 }
688 EXPORT_SYMBOL_GPL(af_alg_free_areq_sgls);
689
690 /**
691 * af_alg_wait_for_wmem - wait for availability of writable memory
692 *
693 * @sk socket of connection to user space
694 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
695 * @return 0 when writable memory is available, < 0 upon error
696 */
697 int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
698 {
699 DEFINE_WAIT_FUNC(wait, woken_wake_function);
700 int err = -ERESTARTSYS;
701 long timeout;
702
703 if (flags & MSG_DONTWAIT)
704 return -EAGAIN;
705
706 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
707
708 add_wait_queue(sk_sleep(sk), &wait);
709 for (;;) {
710 if (signal_pending(current))
711 break;
712 timeout = MAX_SCHEDULE_TIMEOUT;
713 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
714 err = 0;
715 break;
716 }
717 }
718 remove_wait_queue(sk_sleep(sk), &wait);
719
720 return err;
721 }
722 EXPORT_SYMBOL_GPL(af_alg_wait_for_wmem);
723
724 /**
725 * af_alg_wmem_wakeup - wakeup caller when writable memory is available
726 *
727 * @sk socket of connection to user space
728 */
729 void af_alg_wmem_wakeup(struct sock *sk)
730 {
731 struct socket_wq *wq;
732
733 if (!af_alg_writable(sk))
734 return;
735
736 rcu_read_lock();
737 wq = rcu_dereference(sk->sk_wq);
738 if (skwq_has_sleeper(wq))
739 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN |
740 EPOLLRDNORM |
741 EPOLLRDBAND);
742 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
743 rcu_read_unlock();
744 }
745 EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
746
747 /**
748 * af_alg_wait_for_data - wait for availability of TX data
749 *
750 * @sk socket of connection to user space
751 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
752 * @return 0 when writable memory is available, < 0 upon error
753 */
754 int af_alg_wait_for_data(struct sock *sk, unsigned flags)
755 {
756 DEFINE_WAIT_FUNC(wait, woken_wake_function);
757 struct alg_sock *ask = alg_sk(sk);
758 struct af_alg_ctx *ctx = ask->private;
759 long timeout;
760 int err = -ERESTARTSYS;
761
762 if (flags & MSG_DONTWAIT)
763 return -EAGAIN;
764
765 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
766
767 add_wait_queue(sk_sleep(sk), &wait);
768 for (;;) {
769 if (signal_pending(current))
770 break;
771 timeout = MAX_SCHEDULE_TIMEOUT;
772 if (sk_wait_event(sk, &timeout, (ctx->used || !ctx->more),
773 &wait)) {
774 err = 0;
775 break;
776 }
777 }
778 remove_wait_queue(sk_sleep(sk), &wait);
779
780 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
781
782 return err;
783 }
784 EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
785
786 /**
787 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
788 *
789 * @sk socket of connection to user space
790 */
791
792 void af_alg_data_wakeup(struct sock *sk)
793 {
794 struct alg_sock *ask = alg_sk(sk);
795 struct af_alg_ctx *ctx = ask->private;
796 struct socket_wq *wq;
797
798 if (!ctx->used)
799 return;
800
801 rcu_read_lock();
802 wq = rcu_dereference(sk->sk_wq);
803 if (skwq_has_sleeper(wq))
804 wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
805 EPOLLRDNORM |
806 EPOLLRDBAND);
807 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
808 rcu_read_unlock();
809 }
810 EXPORT_SYMBOL_GPL(af_alg_data_wakeup);
811
812 /**
813 * af_alg_sendmsg - implementation of sendmsg system call handler
814 *
815 * The sendmsg system call handler obtains the user data and stores it
816 * in ctx->tsgl_list. This implies allocation of the required numbers of
817 * struct af_alg_tsgl.
818 *
819 * In addition, the ctx is filled with the information sent via CMSG.
820 *
821 * @sock socket of connection to user space
822 * @msg message from user space
823 * @size size of message from user space
824 * @ivsize the size of the IV for the cipher operation to verify that the
825 * user-space-provided IV has the right size
826 * @return the number of copied data upon success, < 0 upon error
827 */
828 int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
829 unsigned int ivsize)
830 {
831 struct sock *sk = sock->sk;
832 struct alg_sock *ask = alg_sk(sk);
833 struct af_alg_ctx *ctx = ask->private;
834 struct af_alg_tsgl *sgl;
835 struct af_alg_control con = {};
836 long copied = 0;
837 bool enc = 0;
838 bool init = 0;
839 int err = 0;
840
841 if (msg->msg_controllen) {
842 err = af_alg_cmsg_send(msg, &con);
843 if (err)
844 return err;
845
846 init = 1;
847 switch (con.op) {
848 case ALG_OP_ENCRYPT:
849 enc = 1;
850 break;
851 case ALG_OP_DECRYPT:
852 enc = 0;
853 break;
854 default:
855 return -EINVAL;
856 }
857
858 if (con.iv && con.iv->ivlen != ivsize)
859 return -EINVAL;
860 }
861
862 lock_sock(sk);
863 if (!ctx->more && ctx->used) {
864 err = -EINVAL;
865 goto unlock;
866 }
867
868 if (init) {
869 ctx->enc = enc;
870 if (con.iv)
871 memcpy(ctx->iv, con.iv->iv, ivsize);
872
873 ctx->aead_assoclen = con.aead_assoclen;
874 }
875
876 while (size) {
877 struct scatterlist *sg;
878 size_t len = size;
879 size_t plen;
880
881 /* use the existing memory in an allocated page */
882 if (ctx->merge) {
883 sgl = list_entry(ctx->tsgl_list.prev,
884 struct af_alg_tsgl, list);
885 sg = sgl->sg + sgl->cur - 1;
886 len = min_t(size_t, len,
887 PAGE_SIZE - sg->offset - sg->length);
888
889 err = memcpy_from_msg(page_address(sg_page(sg)) +
890 sg->offset + sg->length,
891 msg, len);
892 if (err)
893 goto unlock;
894
895 sg->length += len;
896 ctx->merge = (sg->offset + sg->length) &
897 (PAGE_SIZE - 1);
898
899 ctx->used += len;
900 copied += len;
901 size -= len;
902 continue;
903 }
904
905 if (!af_alg_writable(sk)) {
906 err = af_alg_wait_for_wmem(sk, msg->msg_flags);
907 if (err)
908 goto unlock;
909 }
910
911 /* allocate a new page */
912 len = min_t(unsigned long, len, af_alg_sndbuf(sk));
913
914 err = af_alg_alloc_tsgl(sk);
915 if (err)
916 goto unlock;
917
918 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
919 list);
920 sg = sgl->sg;
921 if (sgl->cur)
922 sg_unmark_end(sg + sgl->cur - 1);
923
924 do {
925 unsigned int i = sgl->cur;
926
927 plen = min_t(size_t, len, PAGE_SIZE);
928
929 sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
930 if (!sg_page(sg + i)) {
931 err = -ENOMEM;
932 goto unlock;
933 }
934
935 err = memcpy_from_msg(page_address(sg_page(sg + i)),
936 msg, plen);
937 if (err) {
938 __free_page(sg_page(sg + i));
939 sg_assign_page(sg + i, NULL);
940 goto unlock;
941 }
942
943 sg[i].length = plen;
944 len -= plen;
945 ctx->used += plen;
946 copied += plen;
947 size -= plen;
948 sgl->cur++;
949 } while (len && sgl->cur < MAX_SGL_ENTS);
950
951 if (!size)
952 sg_mark_end(sg + sgl->cur - 1);
953
954 ctx->merge = plen & (PAGE_SIZE - 1);
955 }
956
957 err = 0;
958
959 ctx->more = msg->msg_flags & MSG_MORE;
960
961 unlock:
962 af_alg_data_wakeup(sk);
963 release_sock(sk);
964
965 return copied ?: err;
966 }
967 EXPORT_SYMBOL_GPL(af_alg_sendmsg);
968
969 /**
970 * af_alg_sendpage - sendpage system call handler
971 *
972 * This is a generic implementation of sendpage to fill ctx->tsgl_list.
973 */
974 ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
975 int offset, size_t size, int flags)
976 {
977 struct sock *sk = sock->sk;
978 struct alg_sock *ask = alg_sk(sk);
979 struct af_alg_ctx *ctx = ask->private;
980 struct af_alg_tsgl *sgl;
981 int err = -EINVAL;
982
983 if (flags & MSG_SENDPAGE_NOTLAST)
984 flags |= MSG_MORE;
985
986 lock_sock(sk);
987 if (!ctx->more && ctx->used)
988 goto unlock;
989
990 if (!size)
991 goto done;
992
993 if (!af_alg_writable(sk)) {
994 err = af_alg_wait_for_wmem(sk, flags);
995 if (err)
996 goto unlock;
997 }
998
999 err = af_alg_alloc_tsgl(sk);
1000 if (err)
1001 goto unlock;
1002
1003 ctx->merge = 0;
1004 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
1005
1006 if (sgl->cur)
1007 sg_unmark_end(sgl->sg + sgl->cur - 1);
1008
1009 sg_mark_end(sgl->sg + sgl->cur);
1010
1011 get_page(page);
1012 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
1013 sgl->cur++;
1014 ctx->used += size;
1015
1016 done:
1017 ctx->more = flags & MSG_MORE;
1018
1019 unlock:
1020 af_alg_data_wakeup(sk);
1021 release_sock(sk);
1022
1023 return err ?: size;
1024 }
1025 EXPORT_SYMBOL_GPL(af_alg_sendpage);
1026
1027 /**
1028 * af_alg_free_resources - release resources required for crypto request
1029 */
1030 void af_alg_free_resources(struct af_alg_async_req *areq)
1031 {
1032 struct sock *sk = areq->sk;
1033
1034 af_alg_free_areq_sgls(areq);
1035 sock_kfree_s(sk, areq, areq->areqlen);
1036 }
1037 EXPORT_SYMBOL_GPL(af_alg_free_resources);
1038
1039 /**
1040 * af_alg_async_cb - AIO callback handler
1041 *
1042 * This handler cleans up the struct af_alg_async_req upon completion of the
1043 * AIO operation.
1044 *
1045 * The number of bytes to be generated with the AIO operation must be set
1046 * in areq->outlen before the AIO callback handler is invoked.
1047 */
1048 void af_alg_async_cb(struct crypto_async_request *_req, int err)
1049 {
1050 struct af_alg_async_req *areq = _req->data;
1051 struct sock *sk = areq->sk;
1052 struct kiocb *iocb = areq->iocb;
1053 unsigned int resultlen;
1054
1055 /* Buffer size written by crypto operation. */
1056 resultlen = areq->outlen;
1057
1058 af_alg_free_resources(areq);
1059 sock_put(sk);
1060
1061 iocb->ki_complete(iocb, err ? err : resultlen, 0);
1062 }
1063 EXPORT_SYMBOL_GPL(af_alg_async_cb);
1064
1065 /**
1066 * af_alg_poll - poll system call handler
1067 */
1068 __poll_t af_alg_poll(struct file *file, struct socket *sock,
1069 poll_table *wait)
1070 {
1071 struct sock *sk = sock->sk;
1072 struct alg_sock *ask = alg_sk(sk);
1073 struct af_alg_ctx *ctx = ask->private;
1074 __poll_t mask;
1075
1076 sock_poll_wait(file, sock, wait);
1077 mask = 0;
1078
1079 if (!ctx->more || ctx->used)
1080 mask |= EPOLLIN | EPOLLRDNORM;
1081
1082 if (af_alg_writable(sk))
1083 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1084
1085 return mask;
1086 }
1087 EXPORT_SYMBOL_GPL(af_alg_poll);
1088
1089 /**
1090 * af_alg_alloc_areq - allocate struct af_alg_async_req
1091 *
1092 * @sk socket of connection to user space
1093 * @areqlen size of struct af_alg_async_req + crypto_*_reqsize
1094 * @return allocated data structure or ERR_PTR upon error
1095 */
1096 struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
1097 unsigned int areqlen)
1098 {
1099 struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
1100
1101 if (unlikely(!areq))
1102 return ERR_PTR(-ENOMEM);
1103
1104 areq->areqlen = areqlen;
1105 areq->sk = sk;
1106 areq->last_rsgl = NULL;
1107 INIT_LIST_HEAD(&areq->rsgl_list);
1108 areq->tsgl = NULL;
1109 areq->tsgl_entries = 0;
1110
1111 return areq;
1112 }
1113 EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
1114
1115 /**
1116 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1117 * operation
1118 *
1119 * @sk socket of connection to user space
1120 * @msg user space message
1121 * @flags flags used to invoke recvmsg with
1122 * @areq instance of the cryptographic request that will hold the RX SGL
1123 * @maxsize maximum number of bytes to be pulled from user space
1124 * @outlen number of bytes in the RX SGL
1125 * @return 0 on success, < 0 upon error
1126 */
1127 int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
1128 struct af_alg_async_req *areq, size_t maxsize,
1129 size_t *outlen)
1130 {
1131 struct alg_sock *ask = alg_sk(sk);
1132 struct af_alg_ctx *ctx = ask->private;
1133 size_t len = 0;
1134
1135 while (maxsize > len && msg_data_left(msg)) {
1136 struct af_alg_rsgl *rsgl;
1137 size_t seglen;
1138 int err;
1139
1140 /* limit the amount of readable buffers */
1141 if (!af_alg_readable(sk))
1142 break;
1143
1144 seglen = min_t(size_t, (maxsize - len),
1145 msg_data_left(msg));
1146
1147 if (list_empty(&areq->rsgl_list)) {
1148 rsgl = &areq->first_rsgl;
1149 } else {
1150 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
1151 if (unlikely(!rsgl))
1152 return -ENOMEM;
1153 }
1154
1155 rsgl->sgl.npages = 0;
1156 list_add_tail(&rsgl->list, &areq->rsgl_list);
1157
1158 /* make one iovec available as scatterlist */
1159 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
1160 if (err < 0) {
1161 rsgl->sg_num_bytes = 0;
1162 return err;
1163 }
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 atomic_add(err, &ctx->rcvused);
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);
Linux with added FPC-III support