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crypto: algif_aead - Only wake up when ctx->more is zero
[linux/fpc-iii.git] / crypto / af_alg.c
blobed8ace8675b776c642f1ea337ec4456e81fc6dec
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * af_alg: User-space algorithm interface
4 *
5 * This file provides the user-space API for algorithms.
6 *
7 * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
8 */
9
10 #include <linux/atomic.h>
11 #include <crypto/if_alg.h>
12 #include <linux/crypto.h>
13 #include <linux/init.h>
14 #include <linux/kernel.h>
15 #include <linux/list.h>
16 #include <linux/module.h>
17 #include <linux/net.h>
18 #include <linux/rwsem.h>
19 #include <linux/sched/signal.h>
20 #include <linux/security.h>
21
22 struct alg_type_list {
23 const struct af_alg_type *type;
24 struct list_head list;
25 };
26
27 static atomic_long_t alg_memory_allocated;
28
29 static struct proto alg_proto = {
30 .name = "ALG",
31 .owner = THIS_MODULE,
32 .memory_allocated = &alg_memory_allocated,
33 .obj_size = sizeof(struct alg_sock),
34 };
35
36 static LIST_HEAD(alg_types);
37 static DECLARE_RWSEM(alg_types_sem);
38
39 static const struct af_alg_type *alg_get_type(const char *name)
40 {
41 const struct af_alg_type *type = ERR_PTR(-ENOENT);
42 struct alg_type_list *node;
43
44 down_read(&alg_types_sem);
45 list_for_each_entry(node, &alg_types, list) {
46 if (strcmp(node->type->name, name))
47 continue;
48
49 if (try_module_get(node->type->owner))
50 type = node->type;
51 break;
52 }
53 up_read(&alg_types_sem);
54
55 return type;
56 }
57
58 int af_alg_register_type(const struct af_alg_type *type)
59 {
60 struct alg_type_list *node;
61 int err = -EEXIST;
62
63 down_write(&alg_types_sem);
64 list_for_each_entry(node, &alg_types, list) {
65 if (!strcmp(node->type->name, type->name))
66 goto unlock;
67 }
68
69 node = kmalloc(sizeof(*node), GFP_KERNEL);
70 err = -ENOMEM;
71 if (!node)
72 goto unlock;
73
74 type->ops->owner = THIS_MODULE;
75 if (type->ops_nokey)
76 type->ops_nokey->owner = THIS_MODULE;
77 node->type = type;
78 list_add(&node->list, &alg_types);
79 err = 0;
80
81 unlock:
82 up_write(&alg_types_sem);
83
84 return err;
85 }
86 EXPORT_SYMBOL_GPL(af_alg_register_type);
87
88 int af_alg_unregister_type(const struct af_alg_type *type)
89 {
90 struct alg_type_list *node;
91 int err = -ENOENT;
92
93 down_write(&alg_types_sem);
94 list_for_each_entry(node, &alg_types, list) {
95 if (strcmp(node->type->name, type->name))
96 continue;
97
98 list_del(&node->list);
99 kfree(node);
100 err = 0;
101 break;
102 }
103 up_write(&alg_types_sem);
104
105 return err;
106 }
107 EXPORT_SYMBOL_GPL(af_alg_unregister_type);
108
109 static void alg_do_release(const struct af_alg_type *type, void *private)
110 {
111 if (!type)
112 return;
113
114 type->release(private);
115 module_put(type->owner);
116 }
117
118 int af_alg_release(struct socket *sock)
119 {
120 if (sock->sk) {
121 sock_put(sock->sk);
122 sock->sk = NULL;
123 }
124 return 0;
125 }
126 EXPORT_SYMBOL_GPL(af_alg_release);
127
128 void af_alg_release_parent(struct sock *sk)
129 {
130 struct alg_sock *ask = alg_sk(sk);
131 unsigned int nokey = atomic_read(&ask->nokey_refcnt);
132
133 sk = ask->parent;
134 ask = alg_sk(sk);
135
136 if (nokey)
137 atomic_dec(&ask->nokey_refcnt);
138
139 if (atomic_dec_and_test(&ask->refcnt))
140 sock_put(sk);
141 }
142 EXPORT_SYMBOL_GPL(af_alg_release_parent);
143
144 static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
145 {
146 const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY;
147 struct sock *sk = sock->sk;
148 struct alg_sock *ask = alg_sk(sk);
149 struct sockaddr_alg *sa = (void *)uaddr;
150 const struct af_alg_type *type;
151 void *private;
152 int err;
153
154 if (sock->state == SS_CONNECTED)
155 return -EINVAL;
156
157 if (addr_len < sizeof(*sa))
158 return -EINVAL;
159
160 /* If caller uses non-allowed flag, return error. */
161 if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed))
162 return -EINVAL;
163
164 sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
165 sa->salg_name[sizeof(sa->salg_name) + addr_len - sizeof(*sa) - 1] = 0;
166
167 type = alg_get_type(sa->salg_type);
168 if (IS_ERR(type) && PTR_ERR(type) == -ENOENT) {
169 request_module("algif-%s", sa->salg_type);
170 type = alg_get_type(sa->salg_type);
171 }
172
173 if (IS_ERR(type))
174 return PTR_ERR(type);
175
176 private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask);
177 if (IS_ERR(private)) {
178 module_put(type->owner);
179 return PTR_ERR(private);
180 }
181
182 err = -EBUSY;
183 lock_sock(sk);
184 if (atomic_read(&ask->refcnt))
185 goto unlock;
186
187 swap(ask->type, type);
188 swap(ask->private, private);
189
190 err = 0;
191
192 unlock:
193 release_sock(sk);
194
195 alg_do_release(type, private);
196
197 return err;
198 }
199
200 static int alg_setkey(struct sock *sk, char __user *ukey,
201 unsigned int keylen)
202 {
203 struct alg_sock *ask = alg_sk(sk);
204 const struct af_alg_type *type = ask->type;
205 u8 *key;
206 int err;
207
208 key = sock_kmalloc(sk, keylen, GFP_KERNEL);
209 if (!key)
210 return -ENOMEM;
211
212 err = -EFAULT;
213 if (copy_from_user(key, ukey, keylen))
214 goto out;
215
216 err = type->setkey(ask->private, key, keylen);
217
218 out:
219 sock_kzfree_s(sk, key, keylen);
220
221 return err;
222 }
223
224 static int alg_setsockopt(struct socket *sock, int level, int optname,
225 char __user *optval, unsigned int optlen)
226 {
227 struct sock *sk = sock->sk;
228 struct alg_sock *ask = alg_sk(sk);
229 const struct af_alg_type *type;
230 int err = -EBUSY;
231
232 lock_sock(sk);
233 if (atomic_read(&ask->refcnt) != atomic_read(&ask->nokey_refcnt))
234 goto unlock;
235
236 type = ask->type;
237
238 err = -ENOPROTOOPT;
239 if (level != SOL_ALG || !type)
240 goto unlock;
241
242 switch (optname) {
243 case ALG_SET_KEY:
244 if (sock->state == SS_CONNECTED)
245 goto unlock;
246 if (!type->setkey)
247 goto unlock;
248
249 err = alg_setkey(sk, optval, optlen);
250 break;
251 case ALG_SET_AEAD_AUTHSIZE:
252 if (sock->state == SS_CONNECTED)
253 goto unlock;
254 if (!type->setauthsize)
255 goto unlock;
256 err = type->setauthsize(ask->private, optlen);
257 }
258
259 unlock:
260 release_sock(sk);
261
262 return err;
263 }
264
265 int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern)
266 {
267 struct alg_sock *ask = alg_sk(sk);
268 const struct af_alg_type *type;
269 struct sock *sk2;
270 unsigned int nokey;
271 int err;
272
273 lock_sock(sk);
274 type = ask->type;
275
276 err = -EINVAL;
277 if (!type)
278 goto unlock;
279
280 sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, kern);
281 err = -ENOMEM;
282 if (!sk2)
283 goto unlock;
284
285 sock_init_data(newsock, sk2);
286 security_sock_graft(sk2, newsock);
287 security_sk_clone(sk, sk2);
288
289 err = type->accept(ask->private, sk2);
290
291 nokey = err == -ENOKEY;
292 if (nokey && type->accept_nokey)
293 err = type->accept_nokey(ask->private, sk2);
294
295 if (err)
296 goto unlock;
297
298 if (atomic_inc_return_relaxed(&ask->refcnt) == 1)
299 sock_hold(sk);
300 if (nokey) {
301 atomic_inc(&ask->nokey_refcnt);
302 atomic_set(&alg_sk(sk2)->nokey_refcnt, 1);
303 }
304 alg_sk(sk2)->parent = sk;
305 alg_sk(sk2)->type = type;
306
307 newsock->ops = type->ops;
308 newsock->state = SS_CONNECTED;
309
310 if (nokey)
311 newsock->ops = type->ops_nokey;
312
313 err = 0;
314
315 unlock:
316 release_sock(sk);
317
318 return err;
319 }
320 EXPORT_SYMBOL_GPL(af_alg_accept);
321
322 static int alg_accept(struct socket *sock, struct socket *newsock, int flags,
323 bool kern)
324 {
325 return af_alg_accept(sock->sk, newsock, kern);
326 }
327
328 static const struct proto_ops alg_proto_ops = {
329 .family = PF_ALG,
330 .owner = THIS_MODULE,
331
332 .connect = sock_no_connect,
333 .socketpair = sock_no_socketpair,
334 .getname = sock_no_getname,
335 .ioctl = sock_no_ioctl,
336 .listen = sock_no_listen,
337 .shutdown = sock_no_shutdown,
338 .getsockopt = sock_no_getsockopt,
339 .mmap = sock_no_mmap,
340 .sendpage = sock_no_sendpage,
341 .sendmsg = sock_no_sendmsg,
342 .recvmsg = sock_no_recvmsg,
343
344 .bind = alg_bind,
345 .release = af_alg_release,
346 .setsockopt = alg_setsockopt,
347 .accept = alg_accept,
348 };
349
350 static void alg_sock_destruct(struct sock *sk)
351 {
352 struct alg_sock *ask = alg_sk(sk);
353
354 alg_do_release(ask->type, ask->private);
355 }
356
357 static int alg_create(struct net *net, struct socket *sock, int protocol,
358 int kern)
359 {
360 struct sock *sk;
361 int err;
362
363 if (sock->type != SOCK_SEQPACKET)
364 return -ESOCKTNOSUPPORT;
365 if (protocol != 0)
366 return -EPROTONOSUPPORT;
367
368 err = -ENOMEM;
369 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
370 if (!sk)
371 goto out;
372
373 sock->ops = &alg_proto_ops;
374 sock_init_data(sock, sk);
375
376 sk->sk_destruct = alg_sock_destruct;
377
378 return 0;
379 out:
380 return err;
381 }
382
383 static const struct net_proto_family alg_family = {
384 .family = PF_ALG,
385 .create = alg_create,
386 .owner = THIS_MODULE,
387 };
388
389 int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
390 {
391 size_t off;
392 ssize_t n;
393 int npages, i;
394
395 n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
396 if (n < 0)
397 return n;
398
399 npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT;
400 if (WARN_ON(npages == 0))
401 return -EINVAL;
402 /* Add one extra for linking */
403 sg_init_table(sgl->sg, npages + 1);
404
405 for (i = 0, len = n; i < npages; i++) {
406 int plen = min_t(int, len, PAGE_SIZE - off);
407
408 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
409
410 off = 0;
411 len -= plen;
412 }
413 sg_mark_end(sgl->sg + npages - 1);
414 sgl->npages = npages;
415
416 return n;
417 }
418 EXPORT_SYMBOL_GPL(af_alg_make_sg);
419
420 static void af_alg_link_sg(struct af_alg_sgl *sgl_prev,
421 struct af_alg_sgl *sgl_new)
422 {
423 sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
424 sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
425 }
426
427 void af_alg_free_sg(struct af_alg_sgl *sgl)
428 {
429 int i;
430
431 for (i = 0; i < sgl->npages; i++)
432 put_page(sgl->pages[i]);
433 }
434 EXPORT_SYMBOL_GPL(af_alg_free_sg);
435
436 static int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
437 {
438 struct cmsghdr *cmsg;
439
440 for_each_cmsghdr(cmsg, msg) {
441 if (!CMSG_OK(msg, cmsg))
442 return -EINVAL;
443 if (cmsg->cmsg_level != SOL_ALG)
444 continue;
445
446 switch (cmsg->cmsg_type) {
447 case ALG_SET_IV:
448 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
449 return -EINVAL;
450 con->iv = (void *)CMSG_DATA(cmsg);
451 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
452 sizeof(*con->iv)))
453 return -EINVAL;
454 break;
455
456 case ALG_SET_OP:
457 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
458 return -EINVAL;
459 con->op = *(u32 *)CMSG_DATA(cmsg);
460 break;
461
462 case ALG_SET_AEAD_ASSOCLEN:
463 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
464 return -EINVAL;
465 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
466 break;
467
468 default:
469 return -EINVAL;
470 }
471 }
472
473 return 0;
474 }
475
476 /**
477 * af_alg_alloc_tsgl - allocate the TX SGL
478 *
479 * @sk socket of connection to user space
480 * @return: 0 upon success, < 0 upon error
481 */
482 static int af_alg_alloc_tsgl(struct sock *sk)
483 {
484 struct alg_sock *ask = alg_sk(sk);
485 struct af_alg_ctx *ctx = ask->private;
486 struct af_alg_tsgl *sgl;
487 struct scatterlist *sg = NULL;
488
489 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
490 if (!list_empty(&ctx->tsgl_list))
491 sg = sgl->sg;
492
493 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
494 sgl = sock_kmalloc(sk,
495 struct_size(sgl, sg, (MAX_SGL_ENTS + 1)),
496 GFP_KERNEL);
497 if (!sgl)
498 return -ENOMEM;
499
500 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
501 sgl->cur = 0;
502
503 if (sg)
504 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
505
506 list_add_tail(&sgl->list, &ctx->tsgl_list);
507 }
508
509 return 0;
510 }
511
512 /**
513 * aead_count_tsgl - Count number of TX SG entries
514 *
515 * The counting starts from the beginning of the SGL to @bytes. If
516 * an offset is provided, the counting of the SG entries starts at the offset.
517 *
518 * @sk socket of connection to user space
519 * @bytes Count the number of SG entries holding given number of bytes.
520 * @offset Start the counting of SG entries from the given offset.
521 * @return Number of TX SG entries found given the constraints
522 */
523 unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
524 {
525 const struct alg_sock *ask = alg_sk(sk);
526 const struct af_alg_ctx *ctx = ask->private;
527 const struct af_alg_tsgl *sgl;
528 unsigned int i;
529 unsigned int sgl_count = 0;
530
531 if (!bytes)
532 return 0;
533
534 list_for_each_entry(sgl, &ctx->tsgl_list, list) {
535 const struct scatterlist *sg = sgl->sg;
536
537 for (i = 0; i < sgl->cur; i++) {
538 size_t bytes_count;
539
540 /* Skip offset */
541 if (offset >= sg[i].length) {
542 offset -= sg[i].length;
543 bytes -= sg[i].length;
544 continue;
545 }
546
547 bytes_count = sg[i].length - offset;
548
549 offset = 0;
550 sgl_count++;
551
552 /* If we have seen requested number of bytes, stop */
553 if (bytes_count >= bytes)
554 return sgl_count;
555
556 bytes -= bytes_count;
557 }
558 }
559
560 return sgl_count;
561 }
562 EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
563
564 /**
565 * aead_pull_tsgl - Release the specified buffers from TX SGL
566 *
567 * If @dst is non-null, reassign the pages to dst. The caller must release
568 * the pages. If @dst_offset is given only reassign the pages to @dst starting
569 * at the @dst_offset (byte). The caller must ensure that @dst is large
570 * enough (e.g. by using af_alg_count_tsgl with the same offset).
571 *
572 * @sk socket of connection to user space
573 * @used Number of bytes to pull from TX SGL
574 * @dst If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
575 * caller must release the buffers in dst.
576 * @dst_offset Reassign the TX SGL from given offset. All buffers before
577 * reaching the offset is released.
578 */
579 void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
580 size_t dst_offset)
581 {
582 struct alg_sock *ask = alg_sk(sk);
583 struct af_alg_ctx *ctx = ask->private;
584 struct af_alg_tsgl *sgl;
585 struct scatterlist *sg;
586 unsigned int i, j = 0;
587
588 while (!list_empty(&ctx->tsgl_list)) {
589 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
590 list);
591 sg = sgl->sg;
592
593 for (i = 0; i < sgl->cur; i++) {
594 size_t plen = min_t(size_t, used, sg[i].length);
595 struct page *page = sg_page(sg + i);
596
597 if (!page)
598 continue;
599
600 /*
601 * Assumption: caller created af_alg_count_tsgl(len)
602 * SG entries in dst.
603 */
604 if (dst) {
605 if (dst_offset >= plen) {
606 /* discard page before offset */
607 dst_offset -= plen;
608 } else {
609 /* reassign page to dst after offset */
610 get_page(page);
611 sg_set_page(dst + j, page,
612 plen - dst_offset,
613 sg[i].offset + dst_offset);
614 dst_offset = 0;
615 j++;
616 }
617 }
618
619 sg[i].length -= plen;
620 sg[i].offset += plen;
621
622 used -= plen;
623 ctx->used -= plen;
624
625 if (sg[i].length)
626 return;
627
628 put_page(page);
629 sg_assign_page(sg + i, NULL);
630 }
631
632 list_del(&sgl->list);
633 sock_kfree_s(sk, sgl, struct_size(sgl, sg, MAX_SGL_ENTS + 1));
634 }
635
636 if (!ctx->used)
637 ctx->merge = 0;
638 ctx->init = ctx->more;
639 }
640 EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
641
642 /**
643 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
644 *
645 * @areq Request holding the TX and RX SGL
646 */
647 static void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
648 {
649 struct sock *sk = areq->sk;
650 struct alg_sock *ask = alg_sk(sk);
651 struct af_alg_ctx *ctx = ask->private;
652 struct af_alg_rsgl *rsgl, *tmp;
653 struct scatterlist *tsgl;
654 struct scatterlist *sg;
655 unsigned int i;
656
657 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
658 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
659 af_alg_free_sg(&rsgl->sgl);
660 list_del(&rsgl->list);
661 if (rsgl != &areq->first_rsgl)
662 sock_kfree_s(sk, rsgl, sizeof(*rsgl));
663 }
664
665 tsgl = areq->tsgl;
666 if (tsgl) {
667 for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
668 if (!sg_page(sg))
669 continue;
670 put_page(sg_page(sg));
671 }
672
673 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
674 }
675 }
676
677 /**
678 * af_alg_wait_for_wmem - wait for availability of writable memory
679 *
680 * @sk socket of connection to user space
681 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
682 * @return 0 when writable memory is available, < 0 upon error
683 */
684 static int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
685 {
686 DEFINE_WAIT_FUNC(wait, woken_wake_function);
687 int err = -ERESTARTSYS;
688 long timeout;
689
690 if (flags & MSG_DONTWAIT)
691 return -EAGAIN;
692
693 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
694
695 add_wait_queue(sk_sleep(sk), &wait);
696 for (;;) {
697 if (signal_pending(current))
698 break;
699 timeout = MAX_SCHEDULE_TIMEOUT;
700 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
701 err = 0;
702 break;
703 }
704 }
705 remove_wait_queue(sk_sleep(sk), &wait);
706
707 return err;
708 }
709
710 /**
711 * af_alg_wmem_wakeup - wakeup caller when writable memory is available
712 *
713 * @sk socket of connection to user space
714 */
715 void af_alg_wmem_wakeup(struct sock *sk)
716 {
717 struct socket_wq *wq;
718
719 if (!af_alg_writable(sk))
720 return;
721
722 rcu_read_lock();
723 wq = rcu_dereference(sk->sk_wq);
724 if (skwq_has_sleeper(wq))
725 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN |
726 EPOLLRDNORM |
727 EPOLLRDBAND);
728 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
729 rcu_read_unlock();
730 }
731 EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
732
733 /**
734 * af_alg_wait_for_data - wait for availability of TX data
735 *
736 * @sk socket of connection to user space
737 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
738 * @min Set to minimum request size if partial requests are allowed.
739 * @return 0 when writable memory is available, < 0 upon error
740 */
741 int af_alg_wait_for_data(struct sock *sk, unsigned flags, unsigned min)
742 {
743 DEFINE_WAIT_FUNC(wait, woken_wake_function);
744 struct alg_sock *ask = alg_sk(sk);
745 struct af_alg_ctx *ctx = ask->private;
746 long timeout;
747 int err = -ERESTARTSYS;
748
749 if (flags & MSG_DONTWAIT)
750 return -EAGAIN;
751
752 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
753
754 add_wait_queue(sk_sleep(sk), &wait);
755 for (;;) {
756 if (signal_pending(current))
757 break;
758 timeout = MAX_SCHEDULE_TIMEOUT;
759 if (sk_wait_event(sk, &timeout,
760 ctx->init && (!ctx->more ||
761 (min && ctx->used >= min)),
762 &wait)) {
763 err = 0;
764 break;
765 }
766 }
767 remove_wait_queue(sk_sleep(sk), &wait);
768
769 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
770
771 return err;
772 }
773 EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
774
775 /**
776 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
777 *
778 * @sk socket of connection to user space
779 */
780 static void af_alg_data_wakeup(struct sock *sk)
781 {
782 struct alg_sock *ask = alg_sk(sk);
783 struct af_alg_ctx *ctx = ask->private;
784 struct socket_wq *wq;
785
786 if (!ctx->used)
787 return;
788
789 rcu_read_lock();
790 wq = rcu_dereference(sk->sk_wq);
791 if (skwq_has_sleeper(wq))
792 wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
793 EPOLLRDNORM |
794 EPOLLRDBAND);
795 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
796 rcu_read_unlock();
797 }
798
799 /**
800 * af_alg_sendmsg - implementation of sendmsg system call handler
801 *
802 * The sendmsg system call handler obtains the user data and stores it
803 * in ctx->tsgl_list. This implies allocation of the required numbers of
804 * struct af_alg_tsgl.
805 *
806 * In addition, the ctx is filled with the information sent via CMSG.
807 *
808 * @sock socket of connection to user space
809 * @msg message from user space
810 * @size size of message from user space
811 * @ivsize the size of the IV for the cipher operation to verify that the
812 * user-space-provided IV has the right size
813 * @return the number of copied data upon success, < 0 upon error
814 */
815 int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
816 unsigned int ivsize)
817 {
818 struct sock *sk = sock->sk;
819 struct alg_sock *ask = alg_sk(sk);
820 struct af_alg_ctx *ctx = ask->private;
821 struct af_alg_tsgl *sgl;
822 struct af_alg_control con = {};
823 long copied = 0;
824 bool enc = 0;
825 bool init = 0;
826 int err = 0;
827
828 if (msg->msg_controllen) {
829 err = af_alg_cmsg_send(msg, &con);
830 if (err)
831 return err;
832
833 init = 1;
834 switch (con.op) {
835 case ALG_OP_ENCRYPT:
836 enc = 1;
837 break;
838 case ALG_OP_DECRYPT:
839 enc = 0;
840 break;
841 default:
842 return -EINVAL;
843 }
844
845 if (con.iv && con.iv->ivlen != ivsize)
846 return -EINVAL;
847 }
848
849 lock_sock(sk);
850 if (ctx->init && (init || !ctx->more)) {
851 err = -EINVAL;
852 goto unlock;
853 }
854
855 if (init) {
856 ctx->enc = enc;
857 if (con.iv)
858 memcpy(ctx->iv, con.iv->iv, ivsize);
859
860 ctx->aead_assoclen = con.aead_assoclen;
861 ctx->init = true;
862 }
863
864 while (size) {
865 struct scatterlist *sg;
866 size_t len = size;
867 size_t plen;
868
869 /* use the existing memory in an allocated page */
870 if (ctx->merge) {
871 sgl = list_entry(ctx->tsgl_list.prev,
872 struct af_alg_tsgl, list);
873 sg = sgl->sg + sgl->cur - 1;
874 len = min_t(size_t, len,
875 PAGE_SIZE - sg->offset - sg->length);
876
877 err = memcpy_from_msg(page_address(sg_page(sg)) +
878 sg->offset + sg->length,
879 msg, len);
880 if (err)
881 goto unlock;
882
883 sg->length += len;
884 ctx->merge = (sg->offset + sg->length) &
885 (PAGE_SIZE - 1);
886
887 ctx->used += len;
888 copied += len;
889 size -= len;
890 continue;
891 }
892
893 if (!af_alg_writable(sk)) {
894 err = af_alg_wait_for_wmem(sk, msg->msg_flags);
895 if (err)
896 goto unlock;
897 }
898
899 /* allocate a new page */
900 len = min_t(unsigned long, len, af_alg_sndbuf(sk));
901
902 err = af_alg_alloc_tsgl(sk);
903 if (err)
904 goto unlock;
905
906 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
907 list);
908 sg = sgl->sg;
909 if (sgl->cur)
910 sg_unmark_end(sg + sgl->cur - 1);
911
912 do {
913 unsigned int i = sgl->cur;
914
915 plen = min_t(size_t, len, PAGE_SIZE);
916
917 sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
918 if (!sg_page(sg + i)) {
919 err = -ENOMEM;
920 goto unlock;
921 }
922
923 err = memcpy_from_msg(page_address(sg_page(sg + i)),
924 msg, plen);
925 if (err) {
926 __free_page(sg_page(sg + i));
927 sg_assign_page(sg + i, NULL);
928 goto unlock;
929 }
930
931 sg[i].length = plen;
932 len -= plen;
933 ctx->used += plen;
934 copied += plen;
935 size -= plen;
936 sgl->cur++;
937 } while (len && sgl->cur < MAX_SGL_ENTS);
938
939 if (!size)
940 sg_mark_end(sg + sgl->cur - 1);
941
942 ctx->merge = plen & (PAGE_SIZE - 1);
943 }
944
945 err = 0;
946
947 ctx->more = msg->msg_flags & MSG_MORE;
948
949 unlock:
950 af_alg_data_wakeup(sk);
951 release_sock(sk);
952
953 return copied ?: err;
954 }
955 EXPORT_SYMBOL_GPL(af_alg_sendmsg);
956
957 /**
958 * af_alg_sendpage - sendpage system call handler
959 *
960 * This is a generic implementation of sendpage to fill ctx->tsgl_list.
961 */
962 ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
963 int offset, size_t size, int flags)
964 {
965 struct sock *sk = sock->sk;
966 struct alg_sock *ask = alg_sk(sk);
967 struct af_alg_ctx *ctx = ask->private;
968 struct af_alg_tsgl *sgl;
969 int err = -EINVAL;
970
971 if (flags & MSG_SENDPAGE_NOTLAST)
972 flags |= MSG_MORE;
973
974 lock_sock(sk);
975 if (!ctx->more && ctx->used)
976 goto unlock;
977
978 if (!size)
979 goto done;
980
981 if (!af_alg_writable(sk)) {
982 err = af_alg_wait_for_wmem(sk, flags);
983 if (err)
984 goto unlock;
985 }
986
987 err = af_alg_alloc_tsgl(sk);
988 if (err)
989 goto unlock;
990
991 ctx->merge = 0;
992 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
993
994 if (sgl->cur)
995 sg_unmark_end(sgl->sg + sgl->cur - 1);
996
997 sg_mark_end(sgl->sg + sgl->cur);
998
999 get_page(page);
1000 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
1001 sgl->cur++;
1002 ctx->used += size;
1003
1004 done:
1005 ctx->more = flags & MSG_MORE;
1006
1007 unlock:
1008 af_alg_data_wakeup(sk);
1009 release_sock(sk);
1010
1011 return err ?: size;
1012 }
1013 EXPORT_SYMBOL_GPL(af_alg_sendpage);
1014
1015 /**
1016 * af_alg_free_resources - release resources required for crypto request
1017 */
1018 void af_alg_free_resources(struct af_alg_async_req *areq)
1019 {
1020 struct sock *sk = areq->sk;
1021
1022 af_alg_free_areq_sgls(areq);
1023 sock_kfree_s(sk, areq, areq->areqlen);
1024 }
1025 EXPORT_SYMBOL_GPL(af_alg_free_resources);
1026
1027 /**
1028 * af_alg_async_cb - AIO callback handler
1029 *
1030 * This handler cleans up the struct af_alg_async_req upon completion of the
1031 * AIO operation.
1032 *
1033 * The number of bytes to be generated with the AIO operation must be set
1034 * in areq->outlen before the AIO callback handler is invoked.
1035 */
1036 void af_alg_async_cb(struct crypto_async_request *_req, int err)
1037 {
1038 struct af_alg_async_req *areq = _req->data;
1039 struct sock *sk = areq->sk;
1040 struct kiocb *iocb = areq->iocb;
1041 unsigned int resultlen;
1042
1043 /* Buffer size written by crypto operation. */
1044 resultlen = areq->outlen;
1045
1046 af_alg_free_resources(areq);
1047 sock_put(sk);
1048
1049 iocb->ki_complete(iocb, err ? err : (int)resultlen, 0);
1050 }
1051 EXPORT_SYMBOL_GPL(af_alg_async_cb);
1052
1053 /**
1054 * af_alg_poll - poll system call handler
1055 */
1056 __poll_t af_alg_poll(struct file *file, struct socket *sock,
1057 poll_table *wait)
1058 {
1059 struct sock *sk = sock->sk;
1060 struct alg_sock *ask = alg_sk(sk);
1061 struct af_alg_ctx *ctx = ask->private;
1062 __poll_t mask;
1063
1064 sock_poll_wait(file, sock, wait);
1065 mask = 0;
1066
1067 if (!ctx->more || ctx->used)
1068 mask |= EPOLLIN | EPOLLRDNORM;
1069
1070 if (af_alg_writable(sk))
1071 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1072
1073 return mask;
1074 }
1075 EXPORT_SYMBOL_GPL(af_alg_poll);
1076
1077 /**
1078 * af_alg_alloc_areq - allocate struct af_alg_async_req
1079 *
1080 * @sk socket of connection to user space
1081 * @areqlen size of struct af_alg_async_req + crypto_*_reqsize
1082 * @return allocated data structure or ERR_PTR upon error
1083 */
1084 struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
1085 unsigned int areqlen)
1086 {
1087 struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
1088
1089 if (unlikely(!areq))
1090 return ERR_PTR(-ENOMEM);
1091
1092 areq->areqlen = areqlen;
1093 areq->sk = sk;
1094 areq->last_rsgl = NULL;
1095 INIT_LIST_HEAD(&areq->rsgl_list);
1096 areq->tsgl = NULL;
1097 areq->tsgl_entries = 0;
1098
1099 return areq;
1100 }
1101 EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
1102
1103 /**
1104 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1105 * operation
1106 *
1107 * @sk socket of connection to user space
1108 * @msg user space message
1109 * @flags flags used to invoke recvmsg with
1110 * @areq instance of the cryptographic request that will hold the RX SGL
1111 * @maxsize maximum number of bytes to be pulled from user space
1112 * @outlen number of bytes in the RX SGL
1113 * @return 0 on success, < 0 upon error
1114 */
1115 int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
1116 struct af_alg_async_req *areq, size_t maxsize,
1117 size_t *outlen)
1118 {
1119 struct alg_sock *ask = alg_sk(sk);
1120 struct af_alg_ctx *ctx = ask->private;
1121 size_t len = 0;
1122
1123 while (maxsize > len && msg_data_left(msg)) {
1124 struct af_alg_rsgl *rsgl;
1125 size_t seglen;
1126 int err;
1127
1128 /* limit the amount of readable buffers */
1129 if (!af_alg_readable(sk))
1130 break;
1131
1132 seglen = min_t(size_t, (maxsize - len),
1133 msg_data_left(msg));
1134
1135 if (list_empty(&areq->rsgl_list)) {
1136 rsgl = &areq->first_rsgl;
1137 } else {
1138 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
1139 if (unlikely(!rsgl))
1140 return -ENOMEM;
1141 }
1142
1143 rsgl->sgl.npages = 0;
1144 list_add_tail(&rsgl->list, &areq->rsgl_list);
1145
1146 /* make one iovec available as scatterlist */
1147 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
1148 if (err < 0) {
1149 rsgl->sg_num_bytes = 0;
1150 return err;
1151 }
1152
1153 /* chain the new scatterlist with previous one */
1154 if (areq->last_rsgl)
1155 af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
1156
1157 areq->last_rsgl = rsgl;
1158 len += err;
1159 atomic_add(err, &ctx->rcvused);
1160 rsgl->sg_num_bytes = err;
1161 iov_iter_advance(&msg->msg_iter, err);
1162 }
1163
1164 *outlen = len;
1165 return 0;
1166 }
1167 EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
1168
1169 static int __init af_alg_init(void)
1170 {
1171 int err = proto_register(&alg_proto, 0);
1172
1173 if (err)
1174 goto out;
1175
1176 err = sock_register(&alg_family);
1177 if (err != 0)
1178 goto out_unregister_proto;
1179
1180 out:
1181 return err;
1182
1183 out_unregister_proto:
1184 proto_unregister(&alg_proto);
1185 goto out;
1186 }
1187
1188 static void __exit af_alg_exit(void)
1189 {
1190 sock_unregister(PF_ALG);
1191 proto_unregister(&alg_proto);
1192 }
1193
1194 module_init(af_alg_init);
1195 module_exit(af_alg_exit);
1196 MODULE_LICENSE("GPL");
1197 MODULE_ALIAS_NETPROTO(AF_ALG);
Linux with added FPC-III support