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Linux 4.19.168
[linux/fpc-iii.git] / crypto / af_alg.c
blobd0276a4ed987677450572cb8b4ce694ba6f91990
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 = atomic_read(&ask->nokey_refcnt);
137
138 sk = ask->parent;
139 ask = alg_sk(sk);
140
141 if (nokey)
142 atomic_dec(&ask->nokey_refcnt);
143
144 if (atomic_dec_and_test(&ask->refcnt))
145 sock_put(sk);
146 }
147 EXPORT_SYMBOL_GPL(af_alg_release_parent);
148
149 static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
150 {
151 const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY;
152 struct sock *sk = sock->sk;
153 struct alg_sock *ask = alg_sk(sk);
154 struct sockaddr_alg_new *sa = (void *)uaddr;
155 const struct af_alg_type *type;
156 void *private;
157 int err;
158
159 if (sock->state == SS_CONNECTED)
160 return -EINVAL;
161
162 BUILD_BUG_ON(offsetof(struct sockaddr_alg_new, salg_name) !=
163 offsetof(struct sockaddr_alg, salg_name));
164 BUILD_BUG_ON(offsetof(struct sockaddr_alg, salg_name) != sizeof(*sa));
165
166 if (addr_len < sizeof(*sa) + 1)
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[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 (atomic_read(&ask->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 (atomic_read(&ask->refcnt) != atomic_read(&ask->nokey_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 (atomic_inc_return_relaxed(&ask->refcnt) == 1)
310 sock_hold(sk);
311 if (nokey) {
312 atomic_inc(&ask->nokey_refcnt);
313 atomic_set(&alg_sk(sk2)->nokey_refcnt, 1);
314 }
315 alg_sk(sk2)->parent = sk;
316 alg_sk(sk2)->type = type;
317
318 newsock->ops = type->ops;
319 newsock->state = SS_CONNECTED;
320
321 if (nokey)
322 newsock->ops = type->ops_nokey;
323
324 err = 0;
325
326 unlock:
327 release_sock(sk);
328
329 return err;
330 }
331 EXPORT_SYMBOL_GPL(af_alg_accept);
332
333 static int alg_accept(struct socket *sock, struct socket *newsock, int flags,
334 bool kern)
335 {
336 return af_alg_accept(sock->sk, newsock, kern);
337 }
338
339 static const struct proto_ops alg_proto_ops = {
340 .family = PF_ALG,
341 .owner = THIS_MODULE,
342
343 .connect = sock_no_connect,
344 .socketpair = sock_no_socketpair,
345 .getname = sock_no_getname,
346 .ioctl = sock_no_ioctl,
347 .listen = sock_no_listen,
348 .shutdown = sock_no_shutdown,
349 .getsockopt = sock_no_getsockopt,
350 .mmap = sock_no_mmap,
351 .sendpage = sock_no_sendpage,
352 .sendmsg = sock_no_sendmsg,
353 .recvmsg = sock_no_recvmsg,
354
355 .bind = alg_bind,
356 .release = af_alg_release,
357 .setsockopt = alg_setsockopt,
358 .accept = alg_accept,
359 };
360
361 static void alg_sock_destruct(struct sock *sk)
362 {
363 struct alg_sock *ask = alg_sk(sk);
364
365 alg_do_release(ask->type, ask->private);
366 }
367
368 static int alg_create(struct net *net, struct socket *sock, int protocol,
369 int kern)
370 {
371 struct sock *sk;
372 int err;
373
374 if (sock->type != SOCK_SEQPACKET)
375 return -ESOCKTNOSUPPORT;
376 if (protocol != 0)
377 return -EPROTONOSUPPORT;
378
379 err = -ENOMEM;
380 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
381 if (!sk)
382 goto out;
383
384 sock->ops = &alg_proto_ops;
385 sock_init_data(sock, sk);
386
387 sk->sk_family = PF_ALG;
388 sk->sk_destruct = alg_sock_destruct;
389
390 return 0;
391 out:
392 return err;
393 }
394
395 static const struct net_proto_family alg_family = {
396 .family = PF_ALG,
397 .create = alg_create,
398 .owner = THIS_MODULE,
399 };
400
401 int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
402 {
403 size_t off;
404 ssize_t n;
405 int npages, i;
406
407 n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
408 if (n < 0)
409 return n;
410
411 npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT;
412 if (WARN_ON(npages == 0))
413 return -EINVAL;
414 /* Add one extra for linking */
415 sg_init_table(sgl->sg, npages + 1);
416
417 for (i = 0, len = n; i < npages; i++) {
418 int plen = min_t(int, len, PAGE_SIZE - off);
419
420 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
421
422 off = 0;
423 len -= plen;
424 }
425 sg_mark_end(sgl->sg + npages - 1);
426 sgl->npages = npages;
427
428 return n;
429 }
430 EXPORT_SYMBOL_GPL(af_alg_make_sg);
431
432 void af_alg_link_sg(struct af_alg_sgl *sgl_prev, struct af_alg_sgl *sgl_new)
433 {
434 sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
435 sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
436 }
437 EXPORT_SYMBOL_GPL(af_alg_link_sg);
438
439 void af_alg_free_sg(struct af_alg_sgl *sgl)
440 {
441 int i;
442
443 for (i = 0; i < sgl->npages; i++)
444 put_page(sgl->pages[i]);
445 }
446 EXPORT_SYMBOL_GPL(af_alg_free_sg);
447
448 int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
449 {
450 struct cmsghdr *cmsg;
451
452 for_each_cmsghdr(cmsg, msg) {
453 if (!CMSG_OK(msg, cmsg))
454 return -EINVAL;
455 if (cmsg->cmsg_level != SOL_ALG)
456 continue;
457
458 switch (cmsg->cmsg_type) {
459 case ALG_SET_IV:
460 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
461 return -EINVAL;
462 con->iv = (void *)CMSG_DATA(cmsg);
463 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
464 sizeof(*con->iv)))
465 return -EINVAL;
466 break;
467
468 case ALG_SET_OP:
469 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
470 return -EINVAL;
471 con->op = *(u32 *)CMSG_DATA(cmsg);
472 break;
473
474 case ALG_SET_AEAD_ASSOCLEN:
475 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
476 return -EINVAL;
477 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
478 break;
479
480 default:
481 return -EINVAL;
482 }
483 }
484
485 return 0;
486 }
487 EXPORT_SYMBOL_GPL(af_alg_cmsg_send);
488
489 /**
490 * af_alg_alloc_tsgl - allocate the TX SGL
491 *
492 * @sk socket of connection to user space
493 * @return: 0 upon success, < 0 upon error
494 */
495 int af_alg_alloc_tsgl(struct sock *sk)
496 {
497 struct alg_sock *ask = alg_sk(sk);
498 struct af_alg_ctx *ctx = ask->private;
499 struct af_alg_tsgl *sgl;
500 struct scatterlist *sg = NULL;
501
502 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
503 if (!list_empty(&ctx->tsgl_list))
504 sg = sgl->sg;
505
506 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
507 sgl = sock_kmalloc(sk,
508 struct_size(sgl, sg, (MAX_SGL_ENTS + 1)),
509 GFP_KERNEL);
510 if (!sgl)
511 return -ENOMEM;
512
513 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
514 sgl->cur = 0;
515
516 if (sg)
517 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
518
519 list_add_tail(&sgl->list, &ctx->tsgl_list);
520 }
521
522 return 0;
523 }
524 EXPORT_SYMBOL_GPL(af_alg_alloc_tsgl);
525
526 /**
527 * aead_count_tsgl - Count number of TX SG entries
528 *
529 * The counting starts from the beginning of the SGL to @bytes. If
530 * an offset is provided, the counting of the SG entries starts at the offset.
531 *
532 * @sk socket of connection to user space
533 * @bytes Count the number of SG entries holding given number of bytes.
534 * @offset Start the counting of SG entries from the given offset.
535 * @return Number of TX SG entries found given the constraints
536 */
537 unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
538 {
539 struct alg_sock *ask = alg_sk(sk);
540 struct af_alg_ctx *ctx = ask->private;
541 struct af_alg_tsgl *sgl, *tmp;
542 unsigned int i;
543 unsigned int sgl_count = 0;
544
545 if (!bytes)
546 return 0;
547
548 list_for_each_entry_safe(sgl, tmp, &ctx->tsgl_list, list) {
549 struct scatterlist *sg = sgl->sg;
550
551 for (i = 0; i < sgl->cur; i++) {
552 size_t bytes_count;
553
554 /* Skip offset */
555 if (offset >= sg[i].length) {
556 offset -= sg[i].length;
557 bytes -= sg[i].length;
558 continue;
559 }
560
561 bytes_count = sg[i].length - offset;
562
563 offset = 0;
564 sgl_count++;
565
566 /* If we have seen requested number of bytes, stop */
567 if (bytes_count >= bytes)
568 return sgl_count;
569
570 bytes -= bytes_count;
571 }
572 }
573
574 return sgl_count;
575 }
576 EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
577
578 /**
579 * aead_pull_tsgl - Release the specified buffers from TX SGL
580 *
581 * If @dst is non-null, reassign the pages to dst. The caller must release
582 * the pages. If @dst_offset is given only reassign the pages to @dst starting
583 * at the @dst_offset (byte). The caller must ensure that @dst is large
584 * enough (e.g. by using af_alg_count_tsgl with the same offset).
585 *
586 * @sk socket of connection to user space
587 * @used Number of bytes to pull from TX SGL
588 * @dst If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
589 * caller must release the buffers in dst.
590 * @dst_offset Reassign the TX SGL from given offset. All buffers before
591 * reaching the offset is released.
592 */
593 void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
594 size_t dst_offset)
595 {
596 struct alg_sock *ask = alg_sk(sk);
597 struct af_alg_ctx *ctx = ask->private;
598 struct af_alg_tsgl *sgl;
599 struct scatterlist *sg;
600 unsigned int i, j = 0;
601
602 while (!list_empty(&ctx->tsgl_list)) {
603 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
604 list);
605 sg = sgl->sg;
606
607 for (i = 0; i < sgl->cur; i++) {
608 size_t plen = min_t(size_t, used, sg[i].length);
609 struct page *page = sg_page(sg + i);
610
611 if (!page)
612 continue;
613
614 /*
615 * Assumption: caller created af_alg_count_tsgl(len)
616 * SG entries in dst.
617 */
618 if (dst) {
619 if (dst_offset >= plen) {
620 /* discard page before offset */
621 dst_offset -= plen;
622 } else {
623 /* reassign page to dst after offset */
624 get_page(page);
625 sg_set_page(dst + j, page,
626 plen - dst_offset,
627 sg[i].offset + dst_offset);
628 dst_offset = 0;
629 j++;
630 }
631 }
632
633 sg[i].length -= plen;
634 sg[i].offset += plen;
635
636 used -= plen;
637 ctx->used -= plen;
638
639 if (sg[i].length)
640 return;
641
642 put_page(page);
643 sg_assign_page(sg + i, NULL);
644 }
645
646 list_del(&sgl->list);
647 sock_kfree_s(sk, sgl, sizeof(*sgl) + sizeof(sgl->sg[0]) *
648 (MAX_SGL_ENTS + 1));
649 }
650
651 if (!ctx->used)
652 ctx->merge = 0;
653 }
654 EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
655
656 /**
657 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
658 *
659 * @areq Request holding the TX and RX SGL
660 */
661 void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
662 {
663 struct sock *sk = areq->sk;
664 struct alg_sock *ask = alg_sk(sk);
665 struct af_alg_ctx *ctx = ask->private;
666 struct af_alg_rsgl *rsgl, *tmp;
667 struct scatterlist *tsgl;
668 struct scatterlist *sg;
669 unsigned int i;
670
671 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
672 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
673 af_alg_free_sg(&rsgl->sgl);
674 list_del(&rsgl->list);
675 if (rsgl != &areq->first_rsgl)
676 sock_kfree_s(sk, rsgl, sizeof(*rsgl));
677 }
678
679 tsgl = areq->tsgl;
680 if (tsgl) {
681 for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
682 if (!sg_page(sg))
683 continue;
684 put_page(sg_page(sg));
685 }
686
687 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
688 }
689 }
690 EXPORT_SYMBOL_GPL(af_alg_free_areq_sgls);
691
692 /**
693 * af_alg_wait_for_wmem - wait for availability of writable memory
694 *
695 * @sk socket of connection to user space
696 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
697 * @return 0 when writable memory is available, < 0 upon error
698 */
699 int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
700 {
701 DEFINE_WAIT_FUNC(wait, woken_wake_function);
702 int err = -ERESTARTSYS;
703 long timeout;
704
705 if (flags & MSG_DONTWAIT)
706 return -EAGAIN;
707
708 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
709
710 add_wait_queue(sk_sleep(sk), &wait);
711 for (;;) {
712 if (signal_pending(current))
713 break;
714 timeout = MAX_SCHEDULE_TIMEOUT;
715 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
716 err = 0;
717 break;
718 }
719 }
720 remove_wait_queue(sk_sleep(sk), &wait);
721
722 return err;
723 }
724 EXPORT_SYMBOL_GPL(af_alg_wait_for_wmem);
725
726 /**
727 * af_alg_wmem_wakeup - wakeup caller when writable memory is available
728 *
729 * @sk socket of connection to user space
730 */
731 void af_alg_wmem_wakeup(struct sock *sk)
732 {
733 struct socket_wq *wq;
734
735 if (!af_alg_writable(sk))
736 return;
737
738 rcu_read_lock();
739 wq = rcu_dereference(sk->sk_wq);
740 if (skwq_has_sleeper(wq))
741 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN |
742 EPOLLRDNORM |
743 EPOLLRDBAND);
744 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
745 rcu_read_unlock();
746 }
747 EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
748
749 /**
750 * af_alg_wait_for_data - wait for availability of TX data
751 *
752 * @sk socket of connection to user space
753 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
754 * @return 0 when writable memory is available, < 0 upon error
755 */
756 int af_alg_wait_for_data(struct sock *sk, unsigned flags)
757 {
758 DEFINE_WAIT_FUNC(wait, woken_wake_function);
759 struct alg_sock *ask = alg_sk(sk);
760 struct af_alg_ctx *ctx = ask->private;
761 long timeout;
762 int err = -ERESTARTSYS;
763
764 if (flags & MSG_DONTWAIT)
765 return -EAGAIN;
766
767 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
768
769 add_wait_queue(sk_sleep(sk), &wait);
770 for (;;) {
771 if (signal_pending(current))
772 break;
773 timeout = MAX_SCHEDULE_TIMEOUT;
774 if (sk_wait_event(sk, &timeout, (ctx->used || !ctx->more),
775 &wait)) {
776 err = 0;
777 break;
778 }
779 }
780 remove_wait_queue(sk_sleep(sk), &wait);
781
782 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
783
784 return err;
785 }
786 EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
787
788 /**
789 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
790 *
791 * @sk socket of connection to user space
792 */
793
794 void af_alg_data_wakeup(struct sock *sk)
795 {
796 struct alg_sock *ask = alg_sk(sk);
797 struct af_alg_ctx *ctx = ask->private;
798 struct socket_wq *wq;
799
800 if (!ctx->used)
801 return;
802
803 rcu_read_lock();
804 wq = rcu_dereference(sk->sk_wq);
805 if (skwq_has_sleeper(wq))
806 wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
807 EPOLLRDNORM |
808 EPOLLRDBAND);
809 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
810 rcu_read_unlock();
811 }
812 EXPORT_SYMBOL_GPL(af_alg_data_wakeup);
813
814 /**
815 * af_alg_sendmsg - implementation of sendmsg system call handler
816 *
817 * The sendmsg system call handler obtains the user data and stores it
818 * in ctx->tsgl_list. This implies allocation of the required numbers of
819 * struct af_alg_tsgl.
820 *
821 * In addition, the ctx is filled with the information sent via CMSG.
822 *
823 * @sock socket of connection to user space
824 * @msg message from user space
825 * @size size of message from user space
826 * @ivsize the size of the IV for the cipher operation to verify that the
827 * user-space-provided IV has the right size
828 * @return the number of copied data upon success, < 0 upon error
829 */
830 int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
831 unsigned int ivsize)
832 {
833 struct sock *sk = sock->sk;
834 struct alg_sock *ask = alg_sk(sk);
835 struct af_alg_ctx *ctx = ask->private;
836 struct af_alg_tsgl *sgl;
837 struct af_alg_control con = {};
838 long copied = 0;
839 bool enc = 0;
840 bool init = 0;
841 int err = 0;
842
843 if (msg->msg_controllen) {
844 err = af_alg_cmsg_send(msg, &con);
845 if (err)
846 return err;
847
848 init = 1;
849 switch (con.op) {
850 case ALG_OP_ENCRYPT:
851 enc = 1;
852 break;
853 case ALG_OP_DECRYPT:
854 enc = 0;
855 break;
856 default:
857 return -EINVAL;
858 }
859
860 if (con.iv && con.iv->ivlen != ivsize)
861 return -EINVAL;
862 }
863
864 lock_sock(sk);
865 if (!ctx->more && ctx->used) {
866 err = -EINVAL;
867 goto unlock;
868 }
869
870 if (init) {
871 ctx->enc = enc;
872 if (con.iv)
873 memcpy(ctx->iv, con.iv->iv, ivsize);
874
875 ctx->aead_assoclen = con.aead_assoclen;
876 }
877
878 while (size) {
879 struct scatterlist *sg;
880 size_t len = size;
881 size_t plen;
882
883 /* use the existing memory in an allocated page */
884 if (ctx->merge) {
885 sgl = list_entry(ctx->tsgl_list.prev,
886 struct af_alg_tsgl, list);
887 sg = sgl->sg + sgl->cur - 1;
888 len = min_t(size_t, len,
889 PAGE_SIZE - sg->offset - sg->length);
890
891 err = memcpy_from_msg(page_address(sg_page(sg)) +
892 sg->offset + sg->length,
893 msg, len);
894 if (err)
895 goto unlock;
896
897 sg->length += len;
898 ctx->merge = (sg->offset + sg->length) &
899 (PAGE_SIZE - 1);
900
901 ctx->used += len;
902 copied += len;
903 size -= len;
904 continue;
905 }
906
907 if (!af_alg_writable(sk)) {
908 err = af_alg_wait_for_wmem(sk, msg->msg_flags);
909 if (err)
910 goto unlock;
911 }
912
913 /* allocate a new page */
914 len = min_t(unsigned long, len, af_alg_sndbuf(sk));
915
916 err = af_alg_alloc_tsgl(sk);
917 if (err)
918 goto unlock;
919
920 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
921 list);
922 sg = sgl->sg;
923 if (sgl->cur)
924 sg_unmark_end(sg + sgl->cur - 1);
925
926 do {
927 unsigned int i = sgl->cur;
928
929 plen = min_t(size_t, len, PAGE_SIZE);
930
931 sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
932 if (!sg_page(sg + i)) {
933 err = -ENOMEM;
934 goto unlock;
935 }
936
937 err = memcpy_from_msg(page_address(sg_page(sg + i)),
938 msg, plen);
939 if (err) {
940 __free_page(sg_page(sg + i));
941 sg_assign_page(sg + i, NULL);
942 goto unlock;
943 }
944
945 sg[i].length = plen;
946 len -= plen;
947 ctx->used += plen;
948 copied += plen;
949 size -= plen;
950 sgl->cur++;
951 } while (len && sgl->cur < MAX_SGL_ENTS);
952
953 if (!size)
954 sg_mark_end(sg + sgl->cur - 1);
955
956 ctx->merge = plen & (PAGE_SIZE - 1);
957 }
958
959 err = 0;
960
961 ctx->more = msg->msg_flags & MSG_MORE;
962
963 unlock:
964 af_alg_data_wakeup(sk);
965 release_sock(sk);
966
967 return copied ?: err;
968 }
969 EXPORT_SYMBOL_GPL(af_alg_sendmsg);
970
971 /**
972 * af_alg_sendpage - sendpage system call handler
973 *
974 * This is a generic implementation of sendpage to fill ctx->tsgl_list.
975 */
976 ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
977 int offset, size_t size, int flags)
978 {
979 struct sock *sk = sock->sk;
980 struct alg_sock *ask = alg_sk(sk);
981 struct af_alg_ctx *ctx = ask->private;
982 struct af_alg_tsgl *sgl;
983 int err = -EINVAL;
984
985 if (flags & MSG_SENDPAGE_NOTLAST)
986 flags |= MSG_MORE;
987
988 lock_sock(sk);
989 if (!ctx->more && ctx->used)
990 goto unlock;
991
992 if (!size)
993 goto done;
994
995 if (!af_alg_writable(sk)) {
996 err = af_alg_wait_for_wmem(sk, flags);
997 if (err)
998 goto unlock;
999 }
1000
1001 err = af_alg_alloc_tsgl(sk);
1002 if (err)
1003 goto unlock;
1004
1005 ctx->merge = 0;
1006 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
1007
1008 if (sgl->cur)
1009 sg_unmark_end(sgl->sg + sgl->cur - 1);
1010
1011 sg_mark_end(sgl->sg + sgl->cur);
1012
1013 get_page(page);
1014 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
1015 sgl->cur++;
1016 ctx->used += size;
1017
1018 done:
1019 ctx->more = flags & MSG_MORE;
1020
1021 unlock:
1022 af_alg_data_wakeup(sk);
1023 release_sock(sk);
1024
1025 return err ?: size;
1026 }
1027 EXPORT_SYMBOL_GPL(af_alg_sendpage);
1028
1029 /**
1030 * af_alg_free_resources - release resources required for crypto request
1031 */
1032 void af_alg_free_resources(struct af_alg_async_req *areq)
1033 {
1034 struct sock *sk = areq->sk;
1035
1036 af_alg_free_areq_sgls(areq);
1037 sock_kfree_s(sk, areq, areq->areqlen);
1038 }
1039 EXPORT_SYMBOL_GPL(af_alg_free_resources);
1040
1041 /**
1042 * af_alg_async_cb - AIO callback handler
1043 *
1044 * This handler cleans up the struct af_alg_async_req upon completion of the
1045 * AIO operation.
1046 *
1047 * The number of bytes to be generated with the AIO operation must be set
1048 * in areq->outlen before the AIO callback handler is invoked.
1049 */
1050 void af_alg_async_cb(struct crypto_async_request *_req, int err)
1051 {
1052 struct af_alg_async_req *areq = _req->data;
1053 struct sock *sk = areq->sk;
1054 struct kiocb *iocb = areq->iocb;
1055 unsigned int resultlen;
1056
1057 /* Buffer size written by crypto operation. */
1058 resultlen = areq->outlen;
1059
1060 af_alg_free_resources(areq);
1061 sock_put(sk);
1062
1063 iocb->ki_complete(iocb, err ? err : (int)resultlen, 0);
1064 }
1065 EXPORT_SYMBOL_GPL(af_alg_async_cb);
1066
1067 /**
1068 * af_alg_poll - poll system call handler
1069 */
1070 __poll_t af_alg_poll(struct file *file, struct socket *sock,
1071 poll_table *wait)
1072 {
1073 struct sock *sk = sock->sk;
1074 struct alg_sock *ask = alg_sk(sk);
1075 struct af_alg_ctx *ctx = ask->private;
1076 __poll_t mask;
1077
1078 sock_poll_wait(file, sock, wait);
1079 mask = 0;
1080
1081 if (!ctx->more || ctx->used)
1082 mask |= EPOLLIN | EPOLLRDNORM;
1083
1084 if (af_alg_writable(sk))
1085 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1086
1087 return mask;
1088 }
1089 EXPORT_SYMBOL_GPL(af_alg_poll);
1090
1091 /**
1092 * af_alg_alloc_areq - allocate struct af_alg_async_req
1093 *
1094 * @sk socket of connection to user space
1095 * @areqlen size of struct af_alg_async_req + crypto_*_reqsize
1096 * @return allocated data structure or ERR_PTR upon error
1097 */
1098 struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
1099 unsigned int areqlen)
1100 {
1101 struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
1102
1103 if (unlikely(!areq))
1104 return ERR_PTR(-ENOMEM);
1105
1106 areq->areqlen = areqlen;
1107 areq->sk = sk;
1108 areq->last_rsgl = NULL;
1109 INIT_LIST_HEAD(&areq->rsgl_list);
1110 areq->tsgl = NULL;
1111 areq->tsgl_entries = 0;
1112
1113 return areq;
1114 }
1115 EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
1116
1117 /**
1118 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1119 * operation
1120 *
1121 * @sk socket of connection to user space
1122 * @msg user space message
1123 * @flags flags used to invoke recvmsg with
1124 * @areq instance of the cryptographic request that will hold the RX SGL
1125 * @maxsize maximum number of bytes to be pulled from user space
1126 * @outlen number of bytes in the RX SGL
1127 * @return 0 on success, < 0 upon error
1128 */
1129 int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
1130 struct af_alg_async_req *areq, size_t maxsize,
1131 size_t *outlen)
1132 {
1133 struct alg_sock *ask = alg_sk(sk);
1134 struct af_alg_ctx *ctx = ask->private;
1135 size_t len = 0;
1136
1137 while (maxsize > len && msg_data_left(msg)) {
1138 struct af_alg_rsgl *rsgl;
1139 size_t seglen;
1140 int err;
1141
1142 /* limit the amount of readable buffers */
1143 if (!af_alg_readable(sk))
1144 break;
1145
1146 seglen = min_t(size_t, (maxsize - len),
1147 msg_data_left(msg));
1148
1149 if (list_empty(&areq->rsgl_list)) {
1150 rsgl = &areq->first_rsgl;
1151 } else {
1152 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
1153 if (unlikely(!rsgl))
1154 return -ENOMEM;
1155 }
1156
1157 rsgl->sgl.npages = 0;
1158 list_add_tail(&rsgl->list, &areq->rsgl_list);
1159
1160 /* make one iovec available as scatterlist */
1161 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
1162 if (err < 0) {
1163 rsgl->sg_num_bytes = 0;
1164 return err;
1165 }
1166
1167 /* chain the new scatterlist with previous one */
1168 if (areq->last_rsgl)
1169 af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
1170
1171 areq->last_rsgl = rsgl;
1172 len += err;
1173 atomic_add(err, &ctx->rcvused);
1174 rsgl->sg_num_bytes = err;
1175 iov_iter_advance(&msg->msg_iter, err);
1176 }
1177
1178 *outlen = len;
1179 return 0;
1180 }
1181 EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
1182
1183 static int __init af_alg_init(void)
1184 {
1185 int err = proto_register(&alg_proto, 0);
1186
1187 if (err)
1188 goto out;
1189
1190 err = sock_register(&alg_family);
1191 if (err != 0)
1192 goto out_unregister_proto;
1193
1194 out:
1195 return err;
1196
1197 out_unregister_proto:
1198 proto_unregister(&alg_proto);
1199 goto out;
1200 }
1201
1202 static void __exit af_alg_exit(void)
1203 {
1204 sock_unregister(PF_ALG);
1205 proto_unregister(&alg_proto);
1206 }
1207
1208 module_init(af_alg_init);
1209 module_exit(af_alg_exit);
1210 MODULE_LICENSE("GPL");
1211 MODULE_ALIAS_NETPROTO(AF_ALG);
Linux with added FPC-III support