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[mirror_ubuntu-bionic-kernel.git] / crypto / af_alg.c
1 /*
2 * af_alg: User-space algorithm interface
3 *
4 * This file provides the user-space API for algorithms.
5 *
6 * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the Free
10 * Software Foundation; either version 2 of the License, or (at your option)
11 * any later version.
12 *
13 */
14
15 #include <linux/atomic.h>
16 #include <crypto/if_alg.h>
17 #include <linux/crypto.h>
18 #include <linux/init.h>
19 #include <linux/kernel.h>
20 #include <linux/list.h>
21 #include <linux/module.h>
22 #include <linux/net.h>
23 #include <linux/rwsem.h>
24 #include <linux/sched/signal.h>
25 #include <linux/security.h>
26
27 struct alg_type_list {
28 const struct af_alg_type *type;
29 struct list_head list;
30 };
31
32 static atomic_long_t alg_memory_allocated;
33
34 static struct proto alg_proto = {
35 .name = "ALG",
36 .owner = THIS_MODULE,
37 .memory_allocated = &alg_memory_allocated,
38 .obj_size = sizeof(struct alg_sock),
39 };
40
41 static LIST_HEAD(alg_types);
42 static DECLARE_RWSEM(alg_types_sem);
43
44 static const struct af_alg_type *alg_get_type(const char *name)
45 {
46 const struct af_alg_type *type = ERR_PTR(-ENOENT);
47 struct alg_type_list *node;
48
49 down_read(&alg_types_sem);
50 list_for_each_entry(node, &alg_types, list) {
51 if (strcmp(node->type->name, name))
52 continue;
53
54 if (try_module_get(node->type->owner))
55 type = node->type;
56 break;
57 }
58 up_read(&alg_types_sem);
59
60 return type;
61 }
62
63 int af_alg_register_type(const struct af_alg_type *type)
64 {
65 struct alg_type_list *node;
66 int err = -EEXIST;
67
68 down_write(&alg_types_sem);
69 list_for_each_entry(node, &alg_types, list) {
70 if (!strcmp(node->type->name, type->name))
71 goto unlock;
72 }
73
74 node = kmalloc(sizeof(*node), GFP_KERNEL);
75 err = -ENOMEM;
76 if (!node)
77 goto unlock;
78
79 type->ops->owner = THIS_MODULE;
80 if (type->ops_nokey)
81 type->ops_nokey->owner = THIS_MODULE;
82 node->type = type;
83 list_add(&node->list, &alg_types);
84 err = 0;
85
86 unlock:
87 up_write(&alg_types_sem);
88
89 return err;
90 }
91 EXPORT_SYMBOL_GPL(af_alg_register_type);
92
93 int af_alg_unregister_type(const struct af_alg_type *type)
94 {
95 struct alg_type_list *node;
96 int err = -ENOENT;
97
98 down_write(&alg_types_sem);
99 list_for_each_entry(node, &alg_types, list) {
100 if (strcmp(node->type->name, type->name))
101 continue;
102
103 list_del(&node->list);
104 kfree(node);
105 err = 0;
106 break;
107 }
108 up_write(&alg_types_sem);
109
110 return err;
111 }
112 EXPORT_SYMBOL_GPL(af_alg_unregister_type);
113
114 static void alg_do_release(const struct af_alg_type *type, void *private)
115 {
116 if (!type)
117 return;
118
119 type->release(private);
120 module_put(type->owner);
121 }
122
123 int af_alg_release(struct socket *sock)
124 {
125 if (sock->sk) {
126 sock_put(sock->sk);
127 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 /**
489 * af_alg_alloc_tsgl - allocate the TX SGL
490 *
491 * @sk socket of connection to user space
492 * @return: 0 upon success, < 0 upon error
493 */
494 int af_alg_alloc_tsgl(struct sock *sk)
495 {
496 struct alg_sock *ask = alg_sk(sk);
497 struct af_alg_ctx *ctx = ask->private;
498 struct af_alg_tsgl *sgl;
499 struct scatterlist *sg = NULL;
500
501 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
502 if (!list_empty(&ctx->tsgl_list))
503 sg = sgl->sg;
504
505 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
506 sgl = sock_kmalloc(sk, sizeof(*sgl) +
507 sizeof(sgl->sg[0]) * (MAX_SGL_ENTS + 1),
508 GFP_KERNEL);
509 if (!sgl)
510 return -ENOMEM;
511
512 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
513 sgl->cur = 0;
514
515 if (sg)
516 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
517
518 list_add_tail(&sgl->list, &ctx->tsgl_list);
519 }
520
521 return 0;
522 }
523 EXPORT_SYMBOL_GPL(af_alg_alloc_tsgl);
524
525 /**
526 * aead_count_tsgl - Count number of TX SG entries
527 *
528 * The counting starts from the beginning of the SGL to @bytes. If
529 * an offset is provided, the counting of the SG entries starts at the offset.
530 *
531 * @sk socket of connection to user space
532 * @bytes Count the number of SG entries holding given number of bytes.
533 * @offset Start the counting of SG entries from the given offset.
534 * @return Number of TX SG entries found given the constraints
535 */
536 unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
537 {
538 struct alg_sock *ask = alg_sk(sk);
539 struct af_alg_ctx *ctx = ask->private;
540 struct af_alg_tsgl *sgl, *tmp;
541 unsigned int i;
542 unsigned int sgl_count = 0;
543
544 if (!bytes)
545 return 0;
546
547 list_for_each_entry_safe(sgl, tmp, &ctx->tsgl_list, list) {
548 struct scatterlist *sg = sgl->sg;
549
550 for (i = 0; i < sgl->cur; i++) {
551 size_t bytes_count;
552
553 /* Skip offset */
554 if (offset >= sg[i].length) {
555 offset -= sg[i].length;
556 bytes -= sg[i].length;
557 continue;
558 }
559
560 bytes_count = sg[i].length - offset;
561
562 offset = 0;
563 sgl_count++;
564
565 /* If we have seen requested number of bytes, stop */
566 if (bytes_count >= bytes)
567 return sgl_count;
568
569 bytes -= bytes_count;
570 }
571 }
572
573 return sgl_count;
574 }
575 EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
576
577 /**
578 * aead_pull_tsgl - Release the specified buffers from TX SGL
579 *
580 * If @dst is non-null, reassign the pages to dst. The caller must release
581 * the pages. If @dst_offset is given only reassign the pages to @dst starting
582 * at the @dst_offset (byte). The caller must ensure that @dst is large
583 * enough (e.g. by using af_alg_count_tsgl with the same offset).
584 *
585 * @sk socket of connection to user space
586 * @used Number of bytes to pull from TX SGL
587 * @dst If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
588 * caller must release the buffers in dst.
589 * @dst_offset Reassign the TX SGL from given offset. All buffers before
590 * reaching the offset is released.
591 */
592 void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
593 size_t dst_offset)
594 {
595 struct alg_sock *ask = alg_sk(sk);
596 struct af_alg_ctx *ctx = ask->private;
597 struct af_alg_tsgl *sgl;
598 struct scatterlist *sg;
599 unsigned int i, j = 0;
600
601 while (!list_empty(&ctx->tsgl_list)) {
602 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
603 list);
604 sg = sgl->sg;
605
606 for (i = 0; i < sgl->cur; i++) {
607 size_t plen = min_t(size_t, used, sg[i].length);
608 struct page *page = sg_page(sg + i);
609
610 if (!page)
611 continue;
612
613 /*
614 * Assumption: caller created af_alg_count_tsgl(len)
615 * SG entries in dst.
616 */
617 if (dst) {
618 if (dst_offset >= plen) {
619 /* discard page before offset */
620 dst_offset -= plen;
621 } else {
622 /* reassign page to dst after offset */
623 get_page(page);
624 sg_set_page(dst + j, page,
625 plen - dst_offset,
626 sg[i].offset + dst_offset);
627 dst_offset = 0;
628 j++;
629 }
630 }
631
632 sg[i].length -= plen;
633 sg[i].offset += plen;
634
635 used -= plen;
636 ctx->used -= plen;
637
638 if (sg[i].length)
639 return;
640
641 put_page(page);
642 sg_assign_page(sg + i, NULL);
643 }
644
645 list_del(&sgl->list);
646 sock_kfree_s(sk, sgl, sizeof(*sgl) + sizeof(sgl->sg[0]) *
647 (MAX_SGL_ENTS + 1));
648 }
649
650 if (!ctx->used)
651 ctx->merge = 0;
652 }
653 EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
654
655 /**
656 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
657 *
658 * @areq Request holding the TX and RX SGL
659 */
660 void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
661 {
662 struct sock *sk = areq->sk;
663 struct alg_sock *ask = alg_sk(sk);
664 struct af_alg_ctx *ctx = ask->private;
665 struct af_alg_rsgl *rsgl, *tmp;
666 struct scatterlist *tsgl;
667 struct scatterlist *sg;
668 unsigned int i;
669
670 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
671 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
672 af_alg_free_sg(&rsgl->sgl);
673 list_del(&rsgl->list);
674 if (rsgl != &areq->first_rsgl)
675 sock_kfree_s(sk, rsgl, sizeof(*rsgl));
676 }
677
678 tsgl = areq->tsgl;
679 if (tsgl) {
680 for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
681 if (!sg_page(sg))
682 continue;
683 put_page(sg_page(sg));
684 }
685
686 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
687 }
688 }
689 EXPORT_SYMBOL_GPL(af_alg_free_areq_sgls);
690
691 /**
692 * af_alg_wait_for_wmem - wait for availability of writable memory
693 *
694 * @sk socket of connection to user space
695 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
696 * @return 0 when writable memory is available, < 0 upon error
697 */
698 int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
699 {
700 DEFINE_WAIT_FUNC(wait, woken_wake_function);
701 int err = -ERESTARTSYS;
702 long timeout;
703
704 if (flags & MSG_DONTWAIT)
705 return -EAGAIN;
706
707 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
708
709 add_wait_queue(sk_sleep(sk), &wait);
710 for (;;) {
711 if (signal_pending(current))
712 break;
713 timeout = MAX_SCHEDULE_TIMEOUT;
714 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
715 err = 0;
716 break;
717 }
718 }
719 remove_wait_queue(sk_sleep(sk), &wait);
720
721 return err;
722 }
723 EXPORT_SYMBOL_GPL(af_alg_wait_for_wmem);
724
725 /**
726 * af_alg_wmem_wakeup - wakeup caller when writable memory is available
727 *
728 * @sk socket of connection to user space
729 */
730 void af_alg_wmem_wakeup(struct sock *sk)
731 {
732 struct socket_wq *wq;
733
734 if (!af_alg_writable(sk))
735 return;
736
737 rcu_read_lock();
738 wq = rcu_dereference(sk->sk_wq);
739 if (skwq_has_sleeper(wq))
740 wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
741 POLLRDNORM |
742 POLLRDBAND);
743 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
744 rcu_read_unlock();
745 }
746 EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
747
748 /**
749 * af_alg_wait_for_data - wait for availability of TX data
750 *
751 * @sk socket of connection to user space
752 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
753 * @return 0 when writable memory is available, < 0 upon error
754 */
755 int af_alg_wait_for_data(struct sock *sk, unsigned flags)
756 {
757 DEFINE_WAIT_FUNC(wait, woken_wake_function);
758 struct alg_sock *ask = alg_sk(sk);
759 struct af_alg_ctx *ctx = ask->private;
760 long timeout;
761 int err = -ERESTARTSYS;
762
763 if (flags & MSG_DONTWAIT)
764 return -EAGAIN;
765
766 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
767
768 add_wait_queue(sk_sleep(sk), &wait);
769 for (;;) {
770 if (signal_pending(current))
771 break;
772 timeout = MAX_SCHEDULE_TIMEOUT;
773 if (sk_wait_event(sk, &timeout, (ctx->used || !ctx->more),
774 &wait)) {
775 err = 0;
776 break;
777 }
778 }
779 remove_wait_queue(sk_sleep(sk), &wait);
780
781 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
782
783 return err;
784 }
785 EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
786
787 /**
788 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
789 *
790 * @sk socket of connection to user space
791 */
792
793 void af_alg_data_wakeup(struct sock *sk)
794 {
795 struct alg_sock *ask = alg_sk(sk);
796 struct af_alg_ctx *ctx = ask->private;
797 struct socket_wq *wq;
798
799 if (!ctx->used)
800 return;
801
802 rcu_read_lock();
803 wq = rcu_dereference(sk->sk_wq);
804 if (skwq_has_sleeper(wq))
805 wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
806 POLLRDNORM |
807 POLLRDBAND);
808 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
809 rcu_read_unlock();
810 }
811 EXPORT_SYMBOL_GPL(af_alg_data_wakeup);
812
813 /**
814 * af_alg_sendmsg - implementation of sendmsg system call handler
815 *
816 * The sendmsg system call handler obtains the user data and stores it
817 * in ctx->tsgl_list. This implies allocation of the required numbers of
818 * struct af_alg_tsgl.
819 *
820 * In addition, the ctx is filled with the information sent via CMSG.
821 *
822 * @sock socket of connection to user space
823 * @msg message from user space
824 * @size size of message from user space
825 * @ivsize the size of the IV for the cipher operation to verify that the
826 * user-space-provided IV has the right size
827 * @return the number of copied data upon success, < 0 upon error
828 */
829 int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
830 unsigned int ivsize)
831 {
832 struct sock *sk = sock->sk;
833 struct alg_sock *ask = alg_sk(sk);
834 struct af_alg_ctx *ctx = ask->private;
835 struct af_alg_tsgl *sgl;
836 struct af_alg_control con = {};
837 long copied = 0;
838 bool enc = 0;
839 bool init = 0;
840 int err = 0;
841
842 if (msg->msg_controllen) {
843 err = af_alg_cmsg_send(msg, &con);
844 if (err)
845 return err;
846
847 init = 1;
848 switch (con.op) {
849 case ALG_OP_ENCRYPT:
850 enc = 1;
851 break;
852 case ALG_OP_DECRYPT:
853 enc = 0;
854 break;
855 default:
856 return -EINVAL;
857 }
858
859 if (con.iv && con.iv->ivlen != ivsize)
860 return -EINVAL;
861 }
862
863 lock_sock(sk);
864 if (!ctx->more && ctx->used) {
865 err = -EINVAL;
866 goto unlock;
867 }
868
869 if (init) {
870 ctx->enc = enc;
871 if (con.iv)
872 memcpy(ctx->iv, con.iv->iv, ivsize);
873
874 ctx->aead_assoclen = con.aead_assoclen;
875 }
876
877 while (size) {
878 struct scatterlist *sg;
879 size_t len = size;
880 size_t plen;
881
882 /* use the existing memory in an allocated page */
883 if (ctx->merge) {
884 sgl = list_entry(ctx->tsgl_list.prev,
885 struct af_alg_tsgl, list);
886 sg = sgl->sg + sgl->cur - 1;
887 len = min_t(size_t, len,
888 PAGE_SIZE - sg->offset - sg->length);
889
890 err = memcpy_from_msg(page_address(sg_page(sg)) +
891 sg->offset + sg->length,
892 msg, len);
893 if (err)
894 goto unlock;
895
896 sg->length += len;
897 ctx->merge = (sg->offset + sg->length) &
898 (PAGE_SIZE - 1);
899
900 ctx->used += len;
901 copied += len;
902 size -= len;
903 continue;
904 }
905
906 if (!af_alg_writable(sk)) {
907 err = af_alg_wait_for_wmem(sk, msg->msg_flags);
908 if (err)
909 goto unlock;
910 }
911
912 /* allocate a new page */
913 len = min_t(unsigned long, len, af_alg_sndbuf(sk));
914
915 err = af_alg_alloc_tsgl(sk);
916 if (err)
917 goto unlock;
918
919 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
920 list);
921 sg = sgl->sg;
922 if (sgl->cur)
923 sg_unmark_end(sg + sgl->cur - 1);
924
925 do {
926 unsigned int i = sgl->cur;
927
928 plen = min_t(size_t, len, PAGE_SIZE);
929
930 sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
931 if (!sg_page(sg + i)) {
932 err = -ENOMEM;
933 goto unlock;
934 }
935
936 err = memcpy_from_msg(page_address(sg_page(sg + i)),
937 msg, plen);
938 if (err) {
939 __free_page(sg_page(sg + i));
940 sg_assign_page(sg + i, NULL);
941 goto unlock;
942 }
943
944 sg[i].length = plen;
945 len -= plen;
946 ctx->used += plen;
947 copied += plen;
948 size -= plen;
949 sgl->cur++;
950 } while (len && sgl->cur < MAX_SGL_ENTS);
951
952 if (!size)
953 sg_mark_end(sg + sgl->cur - 1);
954
955 ctx->merge = plen & (PAGE_SIZE - 1);
956 }
957
958 err = 0;
959
960 ctx->more = msg->msg_flags & MSG_MORE;
961
962 unlock:
963 af_alg_data_wakeup(sk);
964 release_sock(sk);
965
966 return copied ?: err;
967 }
968 EXPORT_SYMBOL_GPL(af_alg_sendmsg);
969
970 /**
971 * af_alg_sendpage - sendpage system call handler
972 *
973 * This is a generic implementation of sendpage to fill ctx->tsgl_list.
974 */
975 ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
976 int offset, size_t size, int flags)
977 {
978 struct sock *sk = sock->sk;
979 struct alg_sock *ask = alg_sk(sk);
980 struct af_alg_ctx *ctx = ask->private;
981 struct af_alg_tsgl *sgl;
982 int err = -EINVAL;
983
984 if (flags & MSG_SENDPAGE_NOTLAST)
985 flags |= MSG_MORE;
986
987 lock_sock(sk);
988 if (!ctx->more && ctx->used)
989 goto unlock;
990
991 if (!size)
992 goto done;
993
994 if (!af_alg_writable(sk)) {
995 err = af_alg_wait_for_wmem(sk, flags);
996 if (err)
997 goto unlock;
998 }
999
1000 err = af_alg_alloc_tsgl(sk);
1001 if (err)
1002 goto unlock;
1003
1004 ctx->merge = 0;
1005 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
1006
1007 if (sgl->cur)
1008 sg_unmark_end(sgl->sg + sgl->cur - 1);
1009
1010 sg_mark_end(sgl->sg + sgl->cur);
1011
1012 get_page(page);
1013 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
1014 sgl->cur++;
1015 ctx->used += size;
1016
1017 done:
1018 ctx->more = flags & MSG_MORE;
1019
1020 unlock:
1021 af_alg_data_wakeup(sk);
1022 release_sock(sk);
1023
1024 return err ?: size;
1025 }
1026 EXPORT_SYMBOL_GPL(af_alg_sendpage);
1027
1028 /**
1029 * af_alg_free_resources - release resources required for crypto request
1030 */
1031 void af_alg_free_resources(struct af_alg_async_req *areq)
1032 {
1033 struct sock *sk = areq->sk;
1034
1035 af_alg_free_areq_sgls(areq);
1036 sock_kfree_s(sk, areq, areq->areqlen);
1037 }
1038 EXPORT_SYMBOL_GPL(af_alg_free_resources);
1039
1040 /**
1041 * af_alg_async_cb - AIO callback handler
1042 *
1043 * This handler cleans up the struct af_alg_async_req upon completion of the
1044 * AIO operation.
1045 *
1046 * The number of bytes to be generated with the AIO operation must be set
1047 * in areq->outlen before the AIO callback handler is invoked.
1048 */
1049 void af_alg_async_cb(struct crypto_async_request *_req, int err)
1050 {
1051 struct af_alg_async_req *areq = _req->data;
1052 struct sock *sk = areq->sk;
1053 struct kiocb *iocb = areq->iocb;
1054 unsigned int resultlen;
1055
1056 /* Buffer size written by crypto operation. */
1057 resultlen = areq->outlen;
1058
1059 af_alg_free_resources(areq);
1060 sock_put(sk);
1061
1062 iocb->ki_complete(iocb, err ? err : resultlen, 0);
1063 }
1064 EXPORT_SYMBOL_GPL(af_alg_async_cb);
1065
1066 /**
1067 * af_alg_poll - poll system call handler
1068 */
1069 unsigned int af_alg_poll(struct file *file, struct socket *sock,
1070 poll_table *wait)
1071 {
1072 struct sock *sk = sock->sk;
1073 struct alg_sock *ask = alg_sk(sk);
1074 struct af_alg_ctx *ctx = ask->private;
1075 unsigned int mask;
1076
1077 sock_poll_wait(file, sk_sleep(sk), wait);
1078 mask = 0;
1079
1080 if (!ctx->more || ctx->used)
1081 mask |= POLLIN | POLLRDNORM;
1082
1083 if (af_alg_writable(sk))
1084 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
1085
1086 return mask;
1087 }
1088 EXPORT_SYMBOL_GPL(af_alg_poll);
1089
1090 /**
1091 * af_alg_alloc_areq - allocate struct af_alg_async_req
1092 *
1093 * @sk socket of connection to user space
1094 * @areqlen size of struct af_alg_async_req + crypto_*_reqsize
1095 * @return allocated data structure or ERR_PTR upon error
1096 */
1097 struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
1098 unsigned int areqlen)
1099 {
1100 struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
1101
1102 if (unlikely(!areq))
1103 return ERR_PTR(-ENOMEM);
1104
1105 areq->areqlen = areqlen;
1106 areq->sk = sk;
1107 areq->last_rsgl = NULL;
1108 INIT_LIST_HEAD(&areq->rsgl_list);
1109 areq->tsgl = NULL;
1110 areq->tsgl_entries = 0;
1111
1112 return areq;
1113 }
1114 EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
1115
1116 /**
1117 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1118 * operation
1119 *
1120 * @sk socket of connection to user space
1121 * @msg user space message
1122 * @flags flags used to invoke recvmsg with
1123 * @areq instance of the cryptographic request that will hold the RX SGL
1124 * @maxsize maximum number of bytes to be pulled from user space
1125 * @outlen number of bytes in the RX SGL
1126 * @return 0 on success, < 0 upon error
1127 */
1128 int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
1129 struct af_alg_async_req *areq, size_t maxsize,
1130 size_t *outlen)
1131 {
1132 struct alg_sock *ask = alg_sk(sk);
1133 struct af_alg_ctx *ctx = ask->private;
1134 size_t len = 0;
1135
1136 while (maxsize > len && msg_data_left(msg)) {
1137 struct af_alg_rsgl *rsgl;
1138 size_t seglen;
1139 int err;
1140
1141 /* limit the amount of readable buffers */
1142 if (!af_alg_readable(sk))
1143 break;
1144
1145 seglen = min_t(size_t, (maxsize - len),
1146 msg_data_left(msg));
1147
1148 if (list_empty(&areq->rsgl_list)) {
1149 rsgl = &areq->first_rsgl;
1150 } else {
1151 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
1152 if (unlikely(!rsgl))
1153 return -ENOMEM;
1154 }
1155
1156 rsgl->sgl.npages = 0;
1157 list_add_tail(&rsgl->list, &areq->rsgl_list);
1158
1159 /* make one iovec available as scatterlist */
1160 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
1161 if (err < 0) {
1162 rsgl->sg_num_bytes = 0;
1163 return err;
1164 }
1165
1166 /* chain the new scatterlist with previous one */
1167 if (areq->last_rsgl)
1168 af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
1169
1170 areq->last_rsgl = rsgl;
1171 len += err;
1172 atomic_add(err, &ctx->rcvused);
1173 rsgl->sg_num_bytes = err;
1174 iov_iter_advance(&msg->msg_iter, err);
1175 }
1176
1177 *outlen = len;
1178 return 0;
1179 }
1180 EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
1181
1182 static int __init af_alg_init(void)
1183 {
1184 int err = proto_register(&alg_proto, 0);
1185
1186 if (err)
1187 goto out;
1188
1189 err = sock_register(&alg_family);
1190 if (err != 0)
1191 goto out_unregister_proto;
1192
1193 out:
1194 return err;
1195
1196 out_unregister_proto:
1197 proto_unregister(&alg_proto);
1198 goto out;
1199 }
1200
1201 static void __exit af_alg_exit(void)
1202 {
1203 sock_unregister(PF_ALG);
1204 proto_unregister(&alg_proto);
1205 }
1206
1207 module_init(af_alg_init);
1208 module_exit(af_alg_exit);
1209 MODULE_LICENSE("GPL");
1210 MODULE_ALIAS_NETPROTO(AF_ALG);
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