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Linux 5.9.7
[linux/fpc-iii.git] / crypto / af_alg.c
blob8be8bec07cdd2c7a14f9a65bde64b4ed0b992e94
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.h>
20 #include <linux/sched/signal.h>
21 #include <linux/security.h>
22
23 struct alg_type_list {
24 const struct af_alg_type *type;
25 struct list_head list;
26 };
27
28 static atomic_long_t alg_memory_allocated;
29
30 static struct proto alg_proto = {
31 .name = "ALG",
32 .owner = THIS_MODULE,
33 .memory_allocated = &alg_memory_allocated,
34 .obj_size = sizeof(struct alg_sock),
35 };
36
37 static LIST_HEAD(alg_types);
38 static DECLARE_RWSEM(alg_types_sem);
39
40 static const struct af_alg_type *alg_get_type(const char *name)
41 {
42 const struct af_alg_type *type = ERR_PTR(-ENOENT);
43 struct alg_type_list *node;
44
45 down_read(&alg_types_sem);
46 list_for_each_entry(node, &alg_types, list) {
47 if (strcmp(node->type->name, name))
48 continue;
49
50 if (try_module_get(node->type->owner))
51 type = node->type;
52 break;
53 }
54 up_read(&alg_types_sem);
55
56 return type;
57 }
58
59 int af_alg_register_type(const struct af_alg_type *type)
60 {
61 struct alg_type_list *node;
62 int err = -EEXIST;
63
64 down_write(&alg_types_sem);
65 list_for_each_entry(node, &alg_types, list) {
66 if (!strcmp(node->type->name, type->name))
67 goto unlock;
68 }
69
70 node = kmalloc(sizeof(*node), GFP_KERNEL);
71 err = -ENOMEM;
72 if (!node)
73 goto unlock;
74
75 type->ops->owner = THIS_MODULE;
76 if (type->ops_nokey)
77 type->ops_nokey->owner = THIS_MODULE;
78 node->type = type;
79 list_add(&node->list, &alg_types);
80 err = 0;
81
82 unlock:
83 up_write(&alg_types_sem);
84
85 return err;
86 }
87 EXPORT_SYMBOL_GPL(af_alg_register_type);
88
89 int af_alg_unregister_type(const struct af_alg_type *type)
90 {
91 struct alg_type_list *node;
92 int err = -ENOENT;
93
94 down_write(&alg_types_sem);
95 list_for_each_entry(node, &alg_types, list) {
96 if (strcmp(node->type->name, type->name))
97 continue;
98
99 list_del(&node->list);
100 kfree(node);
101 err = 0;
102 break;
103 }
104 up_write(&alg_types_sem);
105
106 return err;
107 }
108 EXPORT_SYMBOL_GPL(af_alg_unregister_type);
109
110 static void alg_do_release(const struct af_alg_type *type, void *private)
111 {
112 if (!type)
113 return;
114
115 type->release(private);
116 module_put(type->owner);
117 }
118
119 int af_alg_release(struct socket *sock)
120 {
121 if (sock->sk) {
122 sock_put(sock->sk);
123 sock->sk = NULL;
124 }
125 return 0;
126 }
127 EXPORT_SYMBOL_GPL(af_alg_release);
128
129 void af_alg_release_parent(struct sock *sk)
130 {
131 struct alg_sock *ask = alg_sk(sk);
132 unsigned int nokey = atomic_read(&ask->nokey_refcnt);
133
134 sk = ask->parent;
135 ask = alg_sk(sk);
136
137 if (nokey)
138 atomic_dec(&ask->nokey_refcnt);
139
140 if (atomic_dec_and_test(&ask->refcnt))
141 sock_put(sk);
142 }
143 EXPORT_SYMBOL_GPL(af_alg_release_parent);
144
145 static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
146 {
147 const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY;
148 struct sock *sk = sock->sk;
149 struct alg_sock *ask = alg_sk(sk);
150 struct sockaddr_alg *sa = (void *)uaddr;
151 const struct af_alg_type *type;
152 void *private;
153 int err;
154
155 if (sock->state == SS_CONNECTED)
156 return -EINVAL;
157
158 if (addr_len < sizeof(*sa))
159 return -EINVAL;
160
161 /* If caller uses non-allowed flag, return error. */
162 if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed))
163 return -EINVAL;
164
165 sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
166 sa->salg_name[sizeof(sa->salg_name) + addr_len - sizeof(*sa) - 1] = 0;
167
168 type = alg_get_type(sa->salg_type);
169 if (PTR_ERR(type) == -ENOENT) {
170 request_module("algif-%s", sa->salg_type);
171 type = alg_get_type(sa->salg_type);
172 }
173
174 if (IS_ERR(type))
175 return PTR_ERR(type);
176
177 private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask);
178 if (IS_ERR(private)) {
179 module_put(type->owner);
180 return PTR_ERR(private);
181 }
182
183 err = -EBUSY;
184 lock_sock(sk);
185 if (atomic_read(&ask->refcnt))
186 goto unlock;
187
188 swap(ask->type, type);
189 swap(ask->private, private);
190
191 err = 0;
192
193 unlock:
194 release_sock(sk);
195
196 alg_do_release(type, private);
197
198 return err;
199 }
200
201 static int alg_setkey(struct sock *sk, sockptr_t ukey, 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_sockptr(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 sockptr_t 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 .mmap = sock_no_mmap,
339 .sendpage = sock_no_sendpage,
340 .sendmsg = sock_no_sendmsg,
341 .recvmsg = sock_no_recvmsg,
342
343 .bind = alg_bind,
344 .release = af_alg_release,
345 .setsockopt = alg_setsockopt,
346 .accept = alg_accept,
347 };
348
349 static void alg_sock_destruct(struct sock *sk)
350 {
351 struct alg_sock *ask = alg_sk(sk);
352
353 alg_do_release(ask->type, ask->private);
354 }
355
356 static int alg_create(struct net *net, struct socket *sock, int protocol,
357 int kern)
358 {
359 struct sock *sk;
360 int err;
361
362 if (sock->type != SOCK_SEQPACKET)
363 return -ESOCKTNOSUPPORT;
364 if (protocol != 0)
365 return -EPROTONOSUPPORT;
366
367 err = -ENOMEM;
368 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
369 if (!sk)
370 goto out;
371
372 sock->ops = &alg_proto_ops;
373 sock_init_data(sock, sk);
374
375 sk->sk_destruct = alg_sock_destruct;
376
377 return 0;
378 out:
379 return err;
380 }
381
382 static const struct net_proto_family alg_family = {
383 .family = PF_ALG,
384 .create = alg_create,
385 .owner = THIS_MODULE,
386 };
387
388 int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
389 {
390 size_t off;
391 ssize_t n;
392 int npages, i;
393
394 n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
395 if (n < 0)
396 return n;
397
398 npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT;
399 if (WARN_ON(npages == 0))
400 return -EINVAL;
401 /* Add one extra for linking */
402 sg_init_table(sgl->sg, npages + 1);
403
404 for (i = 0, len = n; i < npages; i++) {
405 int plen = min_t(int, len, PAGE_SIZE - off);
406
407 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
408
409 off = 0;
410 len -= plen;
411 }
412 sg_mark_end(sgl->sg + npages - 1);
413 sgl->npages = npages;
414
415 return n;
416 }
417 EXPORT_SYMBOL_GPL(af_alg_make_sg);
418
419 static void af_alg_link_sg(struct af_alg_sgl *sgl_prev,
420 struct af_alg_sgl *sgl_new)
421 {
422 sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
423 sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
424 }
425
426 void af_alg_free_sg(struct af_alg_sgl *sgl)
427 {
428 int i;
429
430 for (i = 0; i < sgl->npages; i++)
431 put_page(sgl->pages[i]);
432 }
433 EXPORT_SYMBOL_GPL(af_alg_free_sg);
434
435 static int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
436 {
437 struct cmsghdr *cmsg;
438
439 for_each_cmsghdr(cmsg, msg) {
440 if (!CMSG_OK(msg, cmsg))
441 return -EINVAL;
442 if (cmsg->cmsg_level != SOL_ALG)
443 continue;
444
445 switch (cmsg->cmsg_type) {
446 case ALG_SET_IV:
447 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
448 return -EINVAL;
449 con->iv = (void *)CMSG_DATA(cmsg);
450 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
451 sizeof(*con->iv)))
452 return -EINVAL;
453 break;
454
455 case ALG_SET_OP:
456 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
457 return -EINVAL;
458 con->op = *(u32 *)CMSG_DATA(cmsg);
459 break;
460
461 case ALG_SET_AEAD_ASSOCLEN:
462 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
463 return -EINVAL;
464 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
465 break;
466
467 default:
468 return -EINVAL;
469 }
470 }
471
472 return 0;
473 }
474
475 /**
476 * af_alg_alloc_tsgl - allocate the TX SGL
477 *
478 * @sk socket of connection to user space
479 * @return: 0 upon success, < 0 upon error
480 */
481 static int af_alg_alloc_tsgl(struct sock *sk)
482 {
483 struct alg_sock *ask = alg_sk(sk);
484 struct af_alg_ctx *ctx = ask->private;
485 struct af_alg_tsgl *sgl;
486 struct scatterlist *sg = NULL;
487
488 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
489 if (!list_empty(&ctx->tsgl_list))
490 sg = sgl->sg;
491
492 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
493 sgl = sock_kmalloc(sk,
494 struct_size(sgl, sg, (MAX_SGL_ENTS + 1)),
495 GFP_KERNEL);
496 if (!sgl)
497 return -ENOMEM;
498
499 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
500 sgl->cur = 0;
501
502 if (sg)
503 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
504
505 list_add_tail(&sgl->list, &ctx->tsgl_list);
506 }
507
508 return 0;
509 }
510
511 /**
512 * aead_count_tsgl - Count number of TX SG entries
513 *
514 * The counting starts from the beginning of the SGL to @bytes. If
515 * an offset is provided, the counting of the SG entries starts at the offset.
516 *
517 * @sk socket of connection to user space
518 * @bytes Count the number of SG entries holding given number of bytes.
519 * @offset Start the counting of SG entries from the given offset.
520 * @return Number of TX SG entries found given the constraints
521 */
522 unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
523 {
524 const struct alg_sock *ask = alg_sk(sk);
525 const struct af_alg_ctx *ctx = ask->private;
526 const struct af_alg_tsgl *sgl;
527 unsigned int i;
528 unsigned int sgl_count = 0;
529
530 if (!bytes)
531 return 0;
532
533 list_for_each_entry(sgl, &ctx->tsgl_list, list) {
534 const struct scatterlist *sg = sgl->sg;
535
536 for (i = 0; i < sgl->cur; i++) {
537 size_t bytes_count;
538
539 /* Skip offset */
540 if (offset >= sg[i].length) {
541 offset -= sg[i].length;
542 bytes -= sg[i].length;
543 continue;
544 }
545
546 bytes_count = sg[i].length - offset;
547
548 offset = 0;
549 sgl_count++;
550
551 /* If we have seen requested number of bytes, stop */
552 if (bytes_count >= bytes)
553 return sgl_count;
554
555 bytes -= bytes_count;
556 }
557 }
558
559 return sgl_count;
560 }
561 EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
562
563 /**
564 * aead_pull_tsgl - Release the specified buffers from TX SGL
565 *
566 * If @dst is non-null, reassign the pages to dst. The caller must release
567 * the pages. If @dst_offset is given only reassign the pages to @dst starting
568 * at the @dst_offset (byte). The caller must ensure that @dst is large
569 * enough (e.g. by using af_alg_count_tsgl with the same offset).
570 *
571 * @sk socket of connection to user space
572 * @used Number of bytes to pull from TX SGL
573 * @dst If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
574 * caller must release the buffers in dst.
575 * @dst_offset Reassign the TX SGL from given offset. All buffers before
576 * reaching the offset is released.
577 */
578 void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
579 size_t dst_offset)
580 {
581 struct alg_sock *ask = alg_sk(sk);
582 struct af_alg_ctx *ctx = ask->private;
583 struct af_alg_tsgl *sgl;
584 struct scatterlist *sg;
585 unsigned int i, j = 0;
586
587 while (!list_empty(&ctx->tsgl_list)) {
588 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
589 list);
590 sg = sgl->sg;
591
592 for (i = 0; i < sgl->cur; i++) {
593 size_t plen = min_t(size_t, used, sg[i].length);
594 struct page *page = sg_page(sg + i);
595
596 if (!page)
597 continue;
598
599 /*
600 * Assumption: caller created af_alg_count_tsgl(len)
601 * SG entries in dst.
602 */
603 if (dst) {
604 if (dst_offset >= plen) {
605 /* discard page before offset */
606 dst_offset -= plen;
607 } else {
608 /* reassign page to dst after offset */
609 get_page(page);
610 sg_set_page(dst + j, page,
611 plen - dst_offset,
612 sg[i].offset + dst_offset);
613 dst_offset = 0;
614 j++;
615 }
616 }
617
618 sg[i].length -= plen;
619 sg[i].offset += plen;
620
621 used -= plen;
622 ctx->used -= plen;
623
624 if (sg[i].length)
625 return;
626
627 put_page(page);
628 sg_assign_page(sg + i, NULL);
629 }
630
631 list_del(&sgl->list);
632 sock_kfree_s(sk, sgl, struct_size(sgl, sg, MAX_SGL_ENTS + 1));
633 }
634
635 if (!ctx->used)
636 ctx->merge = 0;
637 ctx->init = ctx->more;
638 }
639 EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
640
641 /**
642 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
643 *
644 * @areq Request holding the TX and RX SGL
645 */
646 static void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
647 {
648 struct sock *sk = areq->sk;
649 struct alg_sock *ask = alg_sk(sk);
650 struct af_alg_ctx *ctx = ask->private;
651 struct af_alg_rsgl *rsgl, *tmp;
652 struct scatterlist *tsgl;
653 struct scatterlist *sg;
654 unsigned int i;
655
656 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
657 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
658 af_alg_free_sg(&rsgl->sgl);
659 list_del(&rsgl->list);
660 if (rsgl != &areq->first_rsgl)
661 sock_kfree_s(sk, rsgl, sizeof(*rsgl));
662 }
663
664 tsgl = areq->tsgl;
665 if (tsgl) {
666 for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
667 if (!sg_page(sg))
668 continue;
669 put_page(sg_page(sg));
670 }
671
672 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
673 }
674 }
675
676 /**
677 * af_alg_wait_for_wmem - wait for availability of writable memory
678 *
679 * @sk socket of connection to user space
680 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
681 * @return 0 when writable memory is available, < 0 upon error
682 */
683 static int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
684 {
685 DEFINE_WAIT_FUNC(wait, woken_wake_function);
686 int err = -ERESTARTSYS;
687 long timeout;
688
689 if (flags & MSG_DONTWAIT)
690 return -EAGAIN;
691
692 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
693
694 add_wait_queue(sk_sleep(sk), &wait);
695 for (;;) {
696 if (signal_pending(current))
697 break;
698 timeout = MAX_SCHEDULE_TIMEOUT;
699 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
700 err = 0;
701 break;
702 }
703 }
704 remove_wait_queue(sk_sleep(sk), &wait);
705
706 return err;
707 }
708
709 /**
710 * af_alg_wmem_wakeup - wakeup caller when writable memory is available
711 *
712 * @sk socket of connection to user space
713 */
714 void af_alg_wmem_wakeup(struct sock *sk)
715 {
716 struct socket_wq *wq;
717
718 if (!af_alg_writable(sk))
719 return;
720
721 rcu_read_lock();
722 wq = rcu_dereference(sk->sk_wq);
723 if (skwq_has_sleeper(wq))
724 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN |
725 EPOLLRDNORM |
726 EPOLLRDBAND);
727 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
728 rcu_read_unlock();
729 }
730 EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
731
732 /**
733 * af_alg_wait_for_data - wait for availability of TX data
734 *
735 * @sk socket of connection to user space
736 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
737 * @min Set to minimum request size if partial requests are allowed.
738 * @return 0 when writable memory is available, < 0 upon error
739 */
740 int af_alg_wait_for_data(struct sock *sk, unsigned flags, unsigned min)
741 {
742 DEFINE_WAIT_FUNC(wait, woken_wake_function);
743 struct alg_sock *ask = alg_sk(sk);
744 struct af_alg_ctx *ctx = ask->private;
745 long timeout;
746 int err = -ERESTARTSYS;
747
748 if (flags & MSG_DONTWAIT)
749 return -EAGAIN;
750
751 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
752
753 add_wait_queue(sk_sleep(sk), &wait);
754 for (;;) {
755 if (signal_pending(current))
756 break;
757 timeout = MAX_SCHEDULE_TIMEOUT;
758 if (sk_wait_event(sk, &timeout,
759 ctx->init && (!ctx->more ||
760 (min && ctx->used >= min)),
761 &wait)) {
762 err = 0;
763 break;
764 }
765 }
766 remove_wait_queue(sk_sleep(sk), &wait);
767
768 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
769
770 return err;
771 }
772 EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
773
774 /**
775 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
776 *
777 * @sk socket of connection to user space
778 */
779 static void af_alg_data_wakeup(struct sock *sk)
780 {
781 struct alg_sock *ask = alg_sk(sk);
782 struct af_alg_ctx *ctx = ask->private;
783 struct socket_wq *wq;
784
785 if (!ctx->used)
786 return;
787
788 rcu_read_lock();
789 wq = rcu_dereference(sk->sk_wq);
790 if (skwq_has_sleeper(wq))
791 wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
792 EPOLLRDNORM |
793 EPOLLRDBAND);
794 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
795 rcu_read_unlock();
796 }
797
798 /**
799 * af_alg_sendmsg - implementation of sendmsg system call handler
800 *
801 * The sendmsg system call handler obtains the user data and stores it
802 * in ctx->tsgl_list. This implies allocation of the required numbers of
803 * struct af_alg_tsgl.
804 *
805 * In addition, the ctx is filled with the information sent via CMSG.
806 *
807 * @sock socket of connection to user space
808 * @msg message from user space
809 * @size size of message from user space
810 * @ivsize the size of the IV for the cipher operation to verify that the
811 * user-space-provided IV has the right size
812 * @return the number of copied data upon success, < 0 upon error
813 */
814 int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
815 unsigned int ivsize)
816 {
817 struct sock *sk = sock->sk;
818 struct alg_sock *ask = alg_sk(sk);
819 struct af_alg_ctx *ctx = ask->private;
820 struct af_alg_tsgl *sgl;
821 struct af_alg_control con = {};
822 long copied = 0;
823 bool enc = false;
824 bool init = false;
825 int err = 0;
826
827 if (msg->msg_controllen) {
828 err = af_alg_cmsg_send(msg, &con);
829 if (err)
830 return err;
831
832 init = true;
833 switch (con.op) {
834 case ALG_OP_ENCRYPT:
835 enc = true;
836 break;
837 case ALG_OP_DECRYPT:
838 enc = false;
839 break;
840 default:
841 return -EINVAL;
842 }
843
844 if (con.iv && con.iv->ivlen != ivsize)
845 return -EINVAL;
846 }
847
848 lock_sock(sk);
849 if (ctx->init && !ctx->more) {
850 if (ctx->used) {
851 err = -EINVAL;
852 goto unlock;
853 }
854
855 pr_info_once(
856 "%s sent an empty control message without MSG_MORE.\n",
857 current->comm);
858 }
859 ctx->init = true;
860
861 if (init) {
862 ctx->enc = enc;
863 if (con.iv)
864 memcpy(ctx->iv, con.iv->iv, ivsize);
865
866 ctx->aead_assoclen = con.aead_assoclen;
867 }
868
869 while (size) {
870 struct scatterlist *sg;
871 size_t len = size;
872 size_t plen;
873
874 /* use the existing memory in an allocated page */
875 if (ctx->merge) {
876 sgl = list_entry(ctx->tsgl_list.prev,
877 struct af_alg_tsgl, list);
878 sg = sgl->sg + sgl->cur - 1;
879 len = min_t(size_t, len,
880 PAGE_SIZE - sg->offset - sg->length);
881
882 err = memcpy_from_msg(page_address(sg_page(sg)) +
883 sg->offset + sg->length,
884 msg, len);
885 if (err)
886 goto unlock;
887
888 sg->length += len;
889 ctx->merge = (sg->offset + sg->length) &
890 (PAGE_SIZE - 1);
891
892 ctx->used += len;
893 copied += len;
894 size -= len;
895 continue;
896 }
897
898 if (!af_alg_writable(sk)) {
899 err = af_alg_wait_for_wmem(sk, msg->msg_flags);
900 if (err)
901 goto unlock;
902 }
903
904 /* allocate a new page */
905 len = min_t(unsigned long, len, af_alg_sndbuf(sk));
906
907 err = af_alg_alloc_tsgl(sk);
908 if (err)
909 goto unlock;
910
911 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
912 list);
913 sg = sgl->sg;
914 if (sgl->cur)
915 sg_unmark_end(sg + sgl->cur - 1);
916
917 do {
918 unsigned int i = sgl->cur;
919
920 plen = min_t(size_t, len, PAGE_SIZE);
921
922 sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
923 if (!sg_page(sg + i)) {
924 err = -ENOMEM;
925 goto unlock;
926 }
927
928 err = memcpy_from_msg(page_address(sg_page(sg + i)),
929 msg, plen);
930 if (err) {
931 __free_page(sg_page(sg + i));
932 sg_assign_page(sg + i, NULL);
933 goto unlock;
934 }
935
936 sg[i].length = plen;
937 len -= plen;
938 ctx->used += plen;
939 copied += plen;
940 size -= plen;
941 sgl->cur++;
942 } while (len && sgl->cur < MAX_SGL_ENTS);
943
944 if (!size)
945 sg_mark_end(sg + sgl->cur - 1);
946
947 ctx->merge = plen & (PAGE_SIZE - 1);
948 }
949
950 err = 0;
951
952 ctx->more = msg->msg_flags & MSG_MORE;
953
954 unlock:
955 af_alg_data_wakeup(sk);
956 release_sock(sk);
957
958 return copied ?: err;
959 }
960 EXPORT_SYMBOL_GPL(af_alg_sendmsg);
961
962 /**
963 * af_alg_sendpage - sendpage system call handler
964 *
965 * This is a generic implementation of sendpage to fill ctx->tsgl_list.
966 */
967 ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
968 int offset, size_t size, int flags)
969 {
970 struct sock *sk = sock->sk;
971 struct alg_sock *ask = alg_sk(sk);
972 struct af_alg_ctx *ctx = ask->private;
973 struct af_alg_tsgl *sgl;
974 int err = -EINVAL;
975
976 if (flags & MSG_SENDPAGE_NOTLAST)
977 flags |= MSG_MORE;
978
979 lock_sock(sk);
980 if (!ctx->more && ctx->used)
981 goto unlock;
982
983 if (!size)
984 goto done;
985
986 if (!af_alg_writable(sk)) {
987 err = af_alg_wait_for_wmem(sk, flags);
988 if (err)
989 goto unlock;
990 }
991
992 err = af_alg_alloc_tsgl(sk);
993 if (err)
994 goto unlock;
995
996 ctx->merge = 0;
997 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
998
999 if (sgl->cur)
1000 sg_unmark_end(sgl->sg + sgl->cur - 1);
1001
1002 sg_mark_end(sgl->sg + sgl->cur);
1003
1004 get_page(page);
1005 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
1006 sgl->cur++;
1007 ctx->used += size;
1008
1009 done:
1010 ctx->more = flags & MSG_MORE;
1011
1012 unlock:
1013 af_alg_data_wakeup(sk);
1014 release_sock(sk);
1015
1016 return err ?: size;
1017 }
1018 EXPORT_SYMBOL_GPL(af_alg_sendpage);
1019
1020 /**
1021 * af_alg_free_resources - release resources required for crypto request
1022 */
1023 void af_alg_free_resources(struct af_alg_async_req *areq)
1024 {
1025 struct sock *sk = areq->sk;
1026
1027 af_alg_free_areq_sgls(areq);
1028 sock_kfree_s(sk, areq, areq->areqlen);
1029 }
1030 EXPORT_SYMBOL_GPL(af_alg_free_resources);
1031
1032 /**
1033 * af_alg_async_cb - AIO callback handler
1034 *
1035 * This handler cleans up the struct af_alg_async_req upon completion of the
1036 * AIO operation.
1037 *
1038 * The number of bytes to be generated with the AIO operation must be set
1039 * in areq->outlen before the AIO callback handler is invoked.
1040 */
1041 void af_alg_async_cb(struct crypto_async_request *_req, int err)
1042 {
1043 struct af_alg_async_req *areq = _req->data;
1044 struct sock *sk = areq->sk;
1045 struct kiocb *iocb = areq->iocb;
1046 unsigned int resultlen;
1047
1048 /* Buffer size written by crypto operation. */
1049 resultlen = areq->outlen;
1050
1051 af_alg_free_resources(areq);
1052 sock_put(sk);
1053
1054 iocb->ki_complete(iocb, err ? err : (int)resultlen, 0);
1055 }
1056 EXPORT_SYMBOL_GPL(af_alg_async_cb);
1057
1058 /**
1059 * af_alg_poll - poll system call handler
1060 */
1061 __poll_t af_alg_poll(struct file *file, struct socket *sock,
1062 poll_table *wait)
1063 {
1064 struct sock *sk = sock->sk;
1065 struct alg_sock *ask = alg_sk(sk);
1066 struct af_alg_ctx *ctx = ask->private;
1067 __poll_t mask;
1068
1069 sock_poll_wait(file, sock, wait);
1070 mask = 0;
1071
1072 if (!ctx->more || ctx->used)
1073 mask |= EPOLLIN | EPOLLRDNORM;
1074
1075 if (af_alg_writable(sk))
1076 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1077
1078 return mask;
1079 }
1080 EXPORT_SYMBOL_GPL(af_alg_poll);
1081
1082 /**
1083 * af_alg_alloc_areq - allocate struct af_alg_async_req
1084 *
1085 * @sk socket of connection to user space
1086 * @areqlen size of struct af_alg_async_req + crypto_*_reqsize
1087 * @return allocated data structure or ERR_PTR upon error
1088 */
1089 struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
1090 unsigned int areqlen)
1091 {
1092 struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
1093
1094 if (unlikely(!areq))
1095 return ERR_PTR(-ENOMEM);
1096
1097 areq->areqlen = areqlen;
1098 areq->sk = sk;
1099 areq->last_rsgl = NULL;
1100 INIT_LIST_HEAD(&areq->rsgl_list);
1101 areq->tsgl = NULL;
1102 areq->tsgl_entries = 0;
1103
1104 return areq;
1105 }
1106 EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
1107
1108 /**
1109 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1110 * operation
1111 *
1112 * @sk socket of connection to user space
1113 * @msg user space message
1114 * @flags flags used to invoke recvmsg with
1115 * @areq instance of the cryptographic request that will hold the RX SGL
1116 * @maxsize maximum number of bytes to be pulled from user space
1117 * @outlen number of bytes in the RX SGL
1118 * @return 0 on success, < 0 upon error
1119 */
1120 int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
1121 struct af_alg_async_req *areq, size_t maxsize,
1122 size_t *outlen)
1123 {
1124 struct alg_sock *ask = alg_sk(sk);
1125 struct af_alg_ctx *ctx = ask->private;
1126 size_t len = 0;
1127
1128 while (maxsize > len && msg_data_left(msg)) {
1129 struct af_alg_rsgl *rsgl;
1130 size_t seglen;
1131 int err;
1132
1133 /* limit the amount of readable buffers */
1134 if (!af_alg_readable(sk))
1135 break;
1136
1137 seglen = min_t(size_t, (maxsize - len),
1138 msg_data_left(msg));
1139
1140 if (list_empty(&areq->rsgl_list)) {
1141 rsgl = &areq->first_rsgl;
1142 } else {
1143 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
1144 if (unlikely(!rsgl))
1145 return -ENOMEM;
1146 }
1147
1148 rsgl->sgl.npages = 0;
1149 list_add_tail(&rsgl->list, &areq->rsgl_list);
1150
1151 /* make one iovec available as scatterlist */
1152 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
1153 if (err < 0) {
1154 rsgl->sg_num_bytes = 0;
1155 return err;
1156 }
1157
1158 /* chain the new scatterlist with previous one */
1159 if (areq->last_rsgl)
1160 af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
1161
1162 areq->last_rsgl = rsgl;
1163 len += err;
1164 atomic_add(err, &ctx->rcvused);
1165 rsgl->sg_num_bytes = err;
1166 iov_iter_advance(&msg->msg_iter, err);
1167 }
1168
1169 *outlen = len;
1170 return 0;
1171 }
1172 EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
1173
1174 static int __init af_alg_init(void)
1175 {
1176 int err = proto_register(&alg_proto, 0);
1177
1178 if (err)
1179 goto out;
1180
1181 err = sock_register(&alg_family);
1182 if (err != 0)
1183 goto out_unregister_proto;
1184
1185 out:
1186 return err;
1187
1188 out_unregister_proto:
1189 proto_unregister(&alg_proto);
1190 goto out;
1191 }
1192
1193 static void __exit af_alg_exit(void)
1194 {
1195 sock_unregister(PF_ALG);
1196 proto_unregister(&alg_proto);
1197 }
1198
1199 module_init(af_alg_init);
1200 module_exit(af_alg_exit);
1201 MODULE_LICENSE("GPL");
1202 MODULE_ALIAS_NETPROTO(AF_ALG);
Linux with added FPC-III support