Loading...
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
23struct alg_type_list {
24 const struct af_alg_type *type;
25 struct list_head list;
26};
27
28static atomic_long_t alg_memory_allocated;
29
30static 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
37static LIST_HEAD(alg_types);
38static DECLARE_RWSEM(alg_types_sem);
39
40static 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
59int 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
82unlock:
83 up_write(&alg_types_sem);
84
85 return err;
86}
87EXPORT_SYMBOL_GPL(af_alg_register_type);
88
89int 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}
108EXPORT_SYMBOL_GPL(af_alg_unregister_type);
109
110static 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
119int 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}
127EXPORT_SYMBOL_GPL(af_alg_release);
128
129void 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}
143EXPORT_SYMBOL_GPL(af_alg_release_parent);
144
145static 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
193unlock:
194 release_sock(sk);
195
196 alg_do_release(type, private);
197
198 return err;
199}
200
201static 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
218out:
219 sock_kzfree_s(sk, key, keylen);
220
221 return err;
222}
223
224static 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
259unlock:
260 release_sock(sk);
261
262 return err;
263}
264
265int 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
315unlock:
316 release_sock(sk);
317
318 return err;
319}
320EXPORT_SYMBOL_GPL(af_alg_accept);
321
322static 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
328static 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
349static 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
356static 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;
378out:
379 return err;
380}
381
382static const struct net_proto_family alg_family = {
383 .family = PF_ALG,
384 .create = alg_create,
385 .owner = THIS_MODULE,
386};
387
388int 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}
417EXPORT_SYMBOL_GPL(af_alg_make_sg);
418
419static 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
426void 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}
433EXPORT_SYMBOL_GPL(af_alg_free_sg);
434
435static 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 */
481static 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 */
522unsigned 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}
561EXPORT_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 */
578void 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}
639EXPORT_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 */
646static 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 */
683static 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 */
714void 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}
730EXPORT_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 */
740int 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}
772EXPORT_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 */
779static 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 */
814int 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
954unlock:
955 af_alg_data_wakeup(sk);
956 release_sock(sk);
957
958 return copied ?: err;
959}
960EXPORT_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 */
967ssize_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
1009done:
1010 ctx->more = flags & MSG_MORE;
1011
1012unlock:
1013 af_alg_data_wakeup(sk);
1014 release_sock(sk);
1015
1016 return err ?: size;
1017}
1018EXPORT_SYMBOL_GPL(af_alg_sendpage);
1019
1020/**
1021 * af_alg_free_resources - release resources required for crypto request
1022 */
1023void 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}
1030EXPORT_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 */
1041void 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}
1056EXPORT_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}
1080EXPORT_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 */
1089struct 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}
1106EXPORT_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 */
1120int 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}
1172EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
1173
1174static 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
1185out:
1186 return err;
1187
1188out_unregister_proto:
1189 proto_unregister(&alg_proto);
1190 goto out;
1191}
1192
1193static void __exit af_alg_exit(void)
1194{
1195 sock_unregister(PF_ALG);
1196 proto_unregister(&alg_proto);
1197}
1198
1199module_init(af_alg_init);
1200module_exit(af_alg_exit);
1201MODULE_LICENSE("GPL");
1202MODULE_ALIAS_NETPROTO(AF_ALG);
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
22struct alg_type_list {
23 const struct af_alg_type *type;
24 struct list_head list;
25};
26
27static atomic_long_t alg_memory_allocated;
28
29static 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
36static LIST_HEAD(alg_types);
37static DECLARE_RWSEM(alg_types_sem);
38
39static 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
58int 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
81unlock:
82 up_write(&alg_types_sem);
83
84 return err;
85}
86EXPORT_SYMBOL_GPL(af_alg_register_type);
87
88int 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}
107EXPORT_SYMBOL_GPL(af_alg_unregister_type);
108
109static 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
118int 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}
126EXPORT_SYMBOL_GPL(af_alg_release);
127
128void af_alg_release_parent(struct sock *sk)
129{
130 struct alg_sock *ask = alg_sk(sk);
131 unsigned int nokey = ask->nokey_refcnt;
132 bool last = nokey && !ask->refcnt;
133
134 sk = ask->parent;
135 ask = alg_sk(sk);
136
137 lock_sock(sk);
138 ask->nokey_refcnt -= nokey;
139 if (!last)
140 last = !--ask->refcnt;
141 release_sock(sk);
142
143 if (last)
144 sock_put(sk);
145}
146EXPORT_SYMBOL_GPL(af_alg_release_parent);
147
148static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
149{
150 const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY;
151 struct sock *sk = sock->sk;
152 struct alg_sock *ask = alg_sk(sk);
153 struct sockaddr_alg *sa = (void *)uaddr;
154 const struct af_alg_type *type;
155 void *private;
156 int err;
157
158 if (sock->state == SS_CONNECTED)
159 return -EINVAL;
160
161 if (addr_len < sizeof(*sa))
162 return -EINVAL;
163
164 /* If caller uses non-allowed flag, return error. */
165 if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed))
166 return -EINVAL;
167
168 sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
169 sa->salg_name[sizeof(sa->salg_name) + addr_len - sizeof(*sa) - 1] = 0;
170
171 type = alg_get_type(sa->salg_type);
172 if (IS_ERR(type) && PTR_ERR(type) == -ENOENT) {
173 request_module("algif-%s", sa->salg_type);
174 type = alg_get_type(sa->salg_type);
175 }
176
177 if (IS_ERR(type))
178 return PTR_ERR(type);
179
180 private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask);
181 if (IS_ERR(private)) {
182 module_put(type->owner);
183 return PTR_ERR(private);
184 }
185
186 err = -EBUSY;
187 lock_sock(sk);
188 if (ask->refcnt | ask->nokey_refcnt)
189 goto unlock;
190
191 swap(ask->type, type);
192 swap(ask->private, private);
193
194 err = 0;
195
196unlock:
197 release_sock(sk);
198
199 alg_do_release(type, private);
200
201 return err;
202}
203
204static int alg_setkey(struct sock *sk, char __user *ukey,
205 unsigned int keylen)
206{
207 struct alg_sock *ask = alg_sk(sk);
208 const struct af_alg_type *type = ask->type;
209 u8 *key;
210 int err;
211
212 key = sock_kmalloc(sk, keylen, GFP_KERNEL);
213 if (!key)
214 return -ENOMEM;
215
216 err = -EFAULT;
217 if (copy_from_user(key, ukey, keylen))
218 goto out;
219
220 err = type->setkey(ask->private, key, keylen);
221
222out:
223 sock_kzfree_s(sk, key, keylen);
224
225 return err;
226}
227
228static int alg_setsockopt(struct socket *sock, int level, int optname,
229 char __user *optval, unsigned int optlen)
230{
231 struct sock *sk = sock->sk;
232 struct alg_sock *ask = alg_sk(sk);
233 const struct af_alg_type *type;
234 int err = -EBUSY;
235
236 lock_sock(sk);
237 if (ask->refcnt)
238 goto unlock;
239
240 type = ask->type;
241
242 err = -ENOPROTOOPT;
243 if (level != SOL_ALG || !type)
244 goto unlock;
245
246 switch (optname) {
247 case ALG_SET_KEY:
248 if (sock->state == SS_CONNECTED)
249 goto unlock;
250 if (!type->setkey)
251 goto unlock;
252
253 err = alg_setkey(sk, optval, optlen);
254 break;
255 case ALG_SET_AEAD_AUTHSIZE:
256 if (sock->state == SS_CONNECTED)
257 goto unlock;
258 if (!type->setauthsize)
259 goto unlock;
260 err = type->setauthsize(ask->private, optlen);
261 }
262
263unlock:
264 release_sock(sk);
265
266 return err;
267}
268
269int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern)
270{
271 struct alg_sock *ask = alg_sk(sk);
272 const struct af_alg_type *type;
273 struct sock *sk2;
274 unsigned int nokey;
275 int err;
276
277 lock_sock(sk);
278 type = ask->type;
279
280 err = -EINVAL;
281 if (!type)
282 goto unlock;
283
284 sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, kern);
285 err = -ENOMEM;
286 if (!sk2)
287 goto unlock;
288
289 sock_init_data(newsock, sk2);
290 security_sock_graft(sk2, newsock);
291 security_sk_clone(sk, sk2);
292
293 err = type->accept(ask->private, sk2);
294
295 nokey = err == -ENOKEY;
296 if (nokey && type->accept_nokey)
297 err = type->accept_nokey(ask->private, sk2);
298
299 if (err)
300 goto unlock;
301
302 if (nokey || !ask->refcnt++)
303 sock_hold(sk);
304 ask->nokey_refcnt += nokey;
305 alg_sk(sk2)->parent = sk;
306 alg_sk(sk2)->type = type;
307 alg_sk(sk2)->nokey_refcnt = nokey;
308
309 newsock->ops = type->ops;
310 newsock->state = SS_CONNECTED;
311
312 if (nokey)
313 newsock->ops = type->ops_nokey;
314
315 err = 0;
316
317unlock:
318 release_sock(sk);
319
320 return err;
321}
322EXPORT_SYMBOL_GPL(af_alg_accept);
323
324static int alg_accept(struct socket *sock, struct socket *newsock, int flags,
325 bool kern)
326{
327 return af_alg_accept(sock->sk, newsock, kern);
328}
329
330static const struct proto_ops alg_proto_ops = {
331 .family = PF_ALG,
332 .owner = THIS_MODULE,
333
334 .connect = sock_no_connect,
335 .socketpair = sock_no_socketpair,
336 .getname = sock_no_getname,
337 .ioctl = sock_no_ioctl,
338 .listen = sock_no_listen,
339 .shutdown = sock_no_shutdown,
340 .getsockopt = sock_no_getsockopt,
341 .mmap = sock_no_mmap,
342 .sendpage = sock_no_sendpage,
343 .sendmsg = sock_no_sendmsg,
344 .recvmsg = sock_no_recvmsg,
345
346 .bind = alg_bind,
347 .release = af_alg_release,
348 .setsockopt = alg_setsockopt,
349 .accept = alg_accept,
350};
351
352static void alg_sock_destruct(struct sock *sk)
353{
354 struct alg_sock *ask = alg_sk(sk);
355
356 alg_do_release(ask->type, ask->private);
357}
358
359static int alg_create(struct net *net, struct socket *sock, int protocol,
360 int kern)
361{
362 struct sock *sk;
363 int err;
364
365 if (sock->type != SOCK_SEQPACKET)
366 return -ESOCKTNOSUPPORT;
367 if (protocol != 0)
368 return -EPROTONOSUPPORT;
369
370 err = -ENOMEM;
371 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
372 if (!sk)
373 goto out;
374
375 sock->ops = &alg_proto_ops;
376 sock_init_data(sock, sk);
377
378 sk->sk_destruct = alg_sock_destruct;
379
380 return 0;
381out:
382 return err;
383}
384
385static const struct net_proto_family alg_family = {
386 .family = PF_ALG,
387 .create = alg_create,
388 .owner = THIS_MODULE,
389};
390
391int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
392{
393 size_t off;
394 ssize_t n;
395 int npages, i;
396
397 n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
398 if (n < 0)
399 return n;
400
401 npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT;
402 if (WARN_ON(npages == 0))
403 return -EINVAL;
404 /* Add one extra for linking */
405 sg_init_table(sgl->sg, npages + 1);
406
407 for (i = 0, len = n; i < npages; i++) {
408 int plen = min_t(int, len, PAGE_SIZE - off);
409
410 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
411
412 off = 0;
413 len -= plen;
414 }
415 sg_mark_end(sgl->sg + npages - 1);
416 sgl->npages = npages;
417
418 return n;
419}
420EXPORT_SYMBOL_GPL(af_alg_make_sg);
421
422static void af_alg_link_sg(struct af_alg_sgl *sgl_prev,
423 struct af_alg_sgl *sgl_new)
424{
425 sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
426 sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
427}
428
429void af_alg_free_sg(struct af_alg_sgl *sgl)
430{
431 int i;
432
433 for (i = 0; i < sgl->npages; i++)
434 put_page(sgl->pages[i]);
435}
436EXPORT_SYMBOL_GPL(af_alg_free_sg);
437
438static int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
439{
440 struct cmsghdr *cmsg;
441
442 for_each_cmsghdr(cmsg, msg) {
443 if (!CMSG_OK(msg, cmsg))
444 return -EINVAL;
445 if (cmsg->cmsg_level != SOL_ALG)
446 continue;
447
448 switch (cmsg->cmsg_type) {
449 case ALG_SET_IV:
450 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
451 return -EINVAL;
452 con->iv = (void *)CMSG_DATA(cmsg);
453 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
454 sizeof(*con->iv)))
455 return -EINVAL;
456 break;
457
458 case ALG_SET_OP:
459 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
460 return -EINVAL;
461 con->op = *(u32 *)CMSG_DATA(cmsg);
462 break;
463
464 case ALG_SET_AEAD_ASSOCLEN:
465 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
466 return -EINVAL;
467 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
468 break;
469
470 default:
471 return -EINVAL;
472 }
473 }
474
475 return 0;
476}
477
478/**
479 * af_alg_alloc_tsgl - allocate the TX SGL
480 *
481 * @sk socket of connection to user space
482 * @return: 0 upon success, < 0 upon error
483 */
484static int af_alg_alloc_tsgl(struct sock *sk)
485{
486 struct alg_sock *ask = alg_sk(sk);
487 struct af_alg_ctx *ctx = ask->private;
488 struct af_alg_tsgl *sgl;
489 struct scatterlist *sg = NULL;
490
491 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
492 if (!list_empty(&ctx->tsgl_list))
493 sg = sgl->sg;
494
495 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
496 sgl = sock_kmalloc(sk,
497 struct_size(sgl, sg, (MAX_SGL_ENTS + 1)),
498 GFP_KERNEL);
499 if (!sgl)
500 return -ENOMEM;
501
502 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
503 sgl->cur = 0;
504
505 if (sg)
506 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
507
508 list_add_tail(&sgl->list, &ctx->tsgl_list);
509 }
510
511 return 0;
512}
513
514/**
515 * aead_count_tsgl - Count number of TX SG entries
516 *
517 * The counting starts from the beginning of the SGL to @bytes. If
518 * an offset is provided, the counting of the SG entries starts at the offset.
519 *
520 * @sk socket of connection to user space
521 * @bytes Count the number of SG entries holding given number of bytes.
522 * @offset Start the counting of SG entries from the given offset.
523 * @return Number of TX SG entries found given the constraints
524 */
525unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
526{
527 const struct alg_sock *ask = alg_sk(sk);
528 const struct af_alg_ctx *ctx = ask->private;
529 const struct af_alg_tsgl *sgl;
530 unsigned int i;
531 unsigned int sgl_count = 0;
532
533 if (!bytes)
534 return 0;
535
536 list_for_each_entry(sgl, &ctx->tsgl_list, list) {
537 const struct scatterlist *sg = sgl->sg;
538
539 for (i = 0; i < sgl->cur; i++) {
540 size_t bytes_count;
541
542 /* Skip offset */
543 if (offset >= sg[i].length) {
544 offset -= sg[i].length;
545 bytes -= sg[i].length;
546 continue;
547 }
548
549 bytes_count = sg[i].length - offset;
550
551 offset = 0;
552 sgl_count++;
553
554 /* If we have seen requested number of bytes, stop */
555 if (bytes_count >= bytes)
556 return sgl_count;
557
558 bytes -= bytes_count;
559 }
560 }
561
562 return sgl_count;
563}
564EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
565
566/**
567 * aead_pull_tsgl - Release the specified buffers from TX SGL
568 *
569 * If @dst is non-null, reassign the pages to dst. The caller must release
570 * the pages. If @dst_offset is given only reassign the pages to @dst starting
571 * at the @dst_offset (byte). The caller must ensure that @dst is large
572 * enough (e.g. by using af_alg_count_tsgl with the same offset).
573 *
574 * @sk socket of connection to user space
575 * @used Number of bytes to pull from TX SGL
576 * @dst If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
577 * caller must release the buffers in dst.
578 * @dst_offset Reassign the TX SGL from given offset. All buffers before
579 * reaching the offset is released.
580 */
581void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
582 size_t dst_offset)
583{
584 struct alg_sock *ask = alg_sk(sk);
585 struct af_alg_ctx *ctx = ask->private;
586 struct af_alg_tsgl *sgl;
587 struct scatterlist *sg;
588 unsigned int i, j = 0;
589
590 while (!list_empty(&ctx->tsgl_list)) {
591 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
592 list);
593 sg = sgl->sg;
594
595 for (i = 0; i < sgl->cur; i++) {
596 size_t plen = min_t(size_t, used, sg[i].length);
597 struct page *page = sg_page(sg + i);
598
599 if (!page)
600 continue;
601
602 /*
603 * Assumption: caller created af_alg_count_tsgl(len)
604 * SG entries in dst.
605 */
606 if (dst) {
607 if (dst_offset >= plen) {
608 /* discard page before offset */
609 dst_offset -= plen;
610 } else {
611 /* reassign page to dst after offset */
612 get_page(page);
613 sg_set_page(dst + j, page,
614 plen - dst_offset,
615 sg[i].offset + dst_offset);
616 dst_offset = 0;
617 j++;
618 }
619 }
620
621 sg[i].length -= plen;
622 sg[i].offset += plen;
623
624 used -= plen;
625 ctx->used -= plen;
626
627 if (sg[i].length)
628 return;
629
630 put_page(page);
631 sg_assign_page(sg + i, NULL);
632 }
633
634 list_del(&sgl->list);
635 sock_kfree_s(sk, sgl, struct_size(sgl, sg, MAX_SGL_ENTS + 1));
636 }
637
638 if (!ctx->used)
639 ctx->merge = 0;
640}
641EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
642
643/**
644 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
645 *
646 * @areq Request holding the TX and RX SGL
647 */
648static void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
649{
650 struct sock *sk = areq->sk;
651 struct alg_sock *ask = alg_sk(sk);
652 struct af_alg_ctx *ctx = ask->private;
653 struct af_alg_rsgl *rsgl, *tmp;
654 struct scatterlist *tsgl;
655 struct scatterlist *sg;
656 unsigned int i;
657
658 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
659 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
660 af_alg_free_sg(&rsgl->sgl);
661 list_del(&rsgl->list);
662 if (rsgl != &areq->first_rsgl)
663 sock_kfree_s(sk, rsgl, sizeof(*rsgl));
664 }
665
666 tsgl = areq->tsgl;
667 if (tsgl) {
668 for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
669 if (!sg_page(sg))
670 continue;
671 put_page(sg_page(sg));
672 }
673
674 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
675 }
676}
677
678/**
679 * af_alg_wait_for_wmem - wait for availability of writable memory
680 *
681 * @sk socket of connection to user space
682 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
683 * @return 0 when writable memory is available, < 0 upon error
684 */
685static int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
686{
687 DEFINE_WAIT_FUNC(wait, woken_wake_function);
688 int err = -ERESTARTSYS;
689 long timeout;
690
691 if (flags & MSG_DONTWAIT)
692 return -EAGAIN;
693
694 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
695
696 add_wait_queue(sk_sleep(sk), &wait);
697 for (;;) {
698 if (signal_pending(current))
699 break;
700 timeout = MAX_SCHEDULE_TIMEOUT;
701 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
702 err = 0;
703 break;
704 }
705 }
706 remove_wait_queue(sk_sleep(sk), &wait);
707
708 return err;
709}
710
711/**
712 * af_alg_wmem_wakeup - wakeup caller when writable memory is available
713 *
714 * @sk socket of connection to user space
715 */
716void af_alg_wmem_wakeup(struct sock *sk)
717{
718 struct socket_wq *wq;
719
720 if (!af_alg_writable(sk))
721 return;
722
723 rcu_read_lock();
724 wq = rcu_dereference(sk->sk_wq);
725 if (skwq_has_sleeper(wq))
726 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN |
727 EPOLLRDNORM |
728 EPOLLRDBAND);
729 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
730 rcu_read_unlock();
731}
732EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
733
734/**
735 * af_alg_wait_for_data - wait for availability of TX data
736 *
737 * @sk socket of connection to user space
738 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
739 * @return 0 when writable memory is available, < 0 upon error
740 */
741int af_alg_wait_for_data(struct sock *sk, unsigned flags)
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, (ctx->used || !ctx->more),
760 &wait)) {
761 err = 0;
762 break;
763 }
764 }
765 remove_wait_queue(sk_sleep(sk), &wait);
766
767 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
768
769 return err;
770}
771EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
772
773/**
774 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
775 *
776 * @sk socket of connection to user space
777 */
778static void af_alg_data_wakeup(struct sock *sk)
779{
780 struct alg_sock *ask = alg_sk(sk);
781 struct af_alg_ctx *ctx = ask->private;
782 struct socket_wq *wq;
783
784 if (!ctx->used)
785 return;
786
787 rcu_read_lock();
788 wq = rcu_dereference(sk->sk_wq);
789 if (skwq_has_sleeper(wq))
790 wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
791 EPOLLRDNORM |
792 EPOLLRDBAND);
793 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
794 rcu_read_unlock();
795}
796
797/**
798 * af_alg_sendmsg - implementation of sendmsg system call handler
799 *
800 * The sendmsg system call handler obtains the user data and stores it
801 * in ctx->tsgl_list. This implies allocation of the required numbers of
802 * struct af_alg_tsgl.
803 *
804 * In addition, the ctx is filled with the information sent via CMSG.
805 *
806 * @sock socket of connection to user space
807 * @msg message from user space
808 * @size size of message from user space
809 * @ivsize the size of the IV for the cipher operation to verify that the
810 * user-space-provided IV has the right size
811 * @return the number of copied data upon success, < 0 upon error
812 */
813int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
814 unsigned int ivsize)
815{
816 struct sock *sk = sock->sk;
817 struct alg_sock *ask = alg_sk(sk);
818 struct af_alg_ctx *ctx = ask->private;
819 struct af_alg_tsgl *sgl;
820 struct af_alg_control con = {};
821 long copied = 0;
822 bool enc = 0;
823 bool init = 0;
824 int err = 0;
825
826 if (msg->msg_controllen) {
827 err = af_alg_cmsg_send(msg, &con);
828 if (err)
829 return err;
830
831 init = 1;
832 switch (con.op) {
833 case ALG_OP_ENCRYPT:
834 enc = 1;
835 break;
836 case ALG_OP_DECRYPT:
837 enc = 0;
838 break;
839 default:
840 return -EINVAL;
841 }
842
843 if (con.iv && con.iv->ivlen != ivsize)
844 return -EINVAL;
845 }
846
847 lock_sock(sk);
848 if (!ctx->more && ctx->used) {
849 err = -EINVAL;
850 goto unlock;
851 }
852
853 if (init) {
854 ctx->enc = enc;
855 if (con.iv)
856 memcpy(ctx->iv, con.iv->iv, ivsize);
857
858 ctx->aead_assoclen = con.aead_assoclen;
859 }
860
861 while (size) {
862 struct scatterlist *sg;
863 size_t len = size;
864 size_t plen;
865
866 /* use the existing memory in an allocated page */
867 if (ctx->merge) {
868 sgl = list_entry(ctx->tsgl_list.prev,
869 struct af_alg_tsgl, list);
870 sg = sgl->sg + sgl->cur - 1;
871 len = min_t(size_t, len,
872 PAGE_SIZE - sg->offset - sg->length);
873
874 err = memcpy_from_msg(page_address(sg_page(sg)) +
875 sg->offset + sg->length,
876 msg, len);
877 if (err)
878 goto unlock;
879
880 sg->length += len;
881 ctx->merge = (sg->offset + sg->length) &
882 (PAGE_SIZE - 1);
883
884 ctx->used += len;
885 copied += len;
886 size -= len;
887 continue;
888 }
889
890 if (!af_alg_writable(sk)) {
891 err = af_alg_wait_for_wmem(sk, msg->msg_flags);
892 if (err)
893 goto unlock;
894 }
895
896 /* allocate a new page */
897 len = min_t(unsigned long, len, af_alg_sndbuf(sk));
898
899 err = af_alg_alloc_tsgl(sk);
900 if (err)
901 goto unlock;
902
903 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
904 list);
905 sg = sgl->sg;
906 if (sgl->cur)
907 sg_unmark_end(sg + sgl->cur - 1);
908
909 do {
910 unsigned int i = sgl->cur;
911
912 plen = min_t(size_t, len, PAGE_SIZE);
913
914 sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
915 if (!sg_page(sg + i)) {
916 err = -ENOMEM;
917 goto unlock;
918 }
919
920 err = memcpy_from_msg(page_address(sg_page(sg + i)),
921 msg, plen);
922 if (err) {
923 __free_page(sg_page(sg + i));
924 sg_assign_page(sg + i, NULL);
925 goto unlock;
926 }
927
928 sg[i].length = plen;
929 len -= plen;
930 ctx->used += plen;
931 copied += plen;
932 size -= plen;
933 sgl->cur++;
934 } while (len && sgl->cur < MAX_SGL_ENTS);
935
936 if (!size)
937 sg_mark_end(sg + sgl->cur - 1);
938
939 ctx->merge = plen & (PAGE_SIZE - 1);
940 }
941
942 err = 0;
943
944 ctx->more = msg->msg_flags & MSG_MORE;
945
946unlock:
947 af_alg_data_wakeup(sk);
948 release_sock(sk);
949
950 return copied ?: err;
951}
952EXPORT_SYMBOL_GPL(af_alg_sendmsg);
953
954/**
955 * af_alg_sendpage - sendpage system call handler
956 *
957 * This is a generic implementation of sendpage to fill ctx->tsgl_list.
958 */
959ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
960 int offset, size_t size, int flags)
961{
962 struct sock *sk = sock->sk;
963 struct alg_sock *ask = alg_sk(sk);
964 struct af_alg_ctx *ctx = ask->private;
965 struct af_alg_tsgl *sgl;
966 int err = -EINVAL;
967
968 if (flags & MSG_SENDPAGE_NOTLAST)
969 flags |= MSG_MORE;
970
971 lock_sock(sk);
972 if (!ctx->more && ctx->used)
973 goto unlock;
974
975 if (!size)
976 goto done;
977
978 if (!af_alg_writable(sk)) {
979 err = af_alg_wait_for_wmem(sk, flags);
980 if (err)
981 goto unlock;
982 }
983
984 err = af_alg_alloc_tsgl(sk);
985 if (err)
986 goto unlock;
987
988 ctx->merge = 0;
989 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
990
991 if (sgl->cur)
992 sg_unmark_end(sgl->sg + sgl->cur - 1);
993
994 sg_mark_end(sgl->sg + sgl->cur);
995
996 get_page(page);
997 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
998 sgl->cur++;
999 ctx->used += size;
1000
1001done:
1002 ctx->more = flags & MSG_MORE;
1003
1004unlock:
1005 af_alg_data_wakeup(sk);
1006 release_sock(sk);
1007
1008 return err ?: size;
1009}
1010EXPORT_SYMBOL_GPL(af_alg_sendpage);
1011
1012/**
1013 * af_alg_free_resources - release resources required for crypto request
1014 */
1015void af_alg_free_resources(struct af_alg_async_req *areq)
1016{
1017 struct sock *sk = areq->sk;
1018
1019 af_alg_free_areq_sgls(areq);
1020 sock_kfree_s(sk, areq, areq->areqlen);
1021}
1022EXPORT_SYMBOL_GPL(af_alg_free_resources);
1023
1024/**
1025 * af_alg_async_cb - AIO callback handler
1026 *
1027 * This handler cleans up the struct af_alg_async_req upon completion of the
1028 * AIO operation.
1029 *
1030 * The number of bytes to be generated with the AIO operation must be set
1031 * in areq->outlen before the AIO callback handler is invoked.
1032 */
1033void af_alg_async_cb(struct crypto_async_request *_req, int err)
1034{
1035 struct af_alg_async_req *areq = _req->data;
1036 struct sock *sk = areq->sk;
1037 struct kiocb *iocb = areq->iocb;
1038 unsigned int resultlen;
1039
1040 /* Buffer size written by crypto operation. */
1041 resultlen = areq->outlen;
1042
1043 af_alg_free_resources(areq);
1044 sock_put(sk);
1045
1046 iocb->ki_complete(iocb, err ? err : resultlen, 0);
1047}
1048EXPORT_SYMBOL_GPL(af_alg_async_cb);
1049
1050/**
1051 * af_alg_poll - poll system call handler
1052 */
1053__poll_t af_alg_poll(struct file *file, struct socket *sock,
1054 poll_table *wait)
1055{
1056 struct sock *sk = sock->sk;
1057 struct alg_sock *ask = alg_sk(sk);
1058 struct af_alg_ctx *ctx = ask->private;
1059 __poll_t mask;
1060
1061 sock_poll_wait(file, sock, wait);
1062 mask = 0;
1063
1064 if (!ctx->more || ctx->used)
1065 mask |= EPOLLIN | EPOLLRDNORM;
1066
1067 if (af_alg_writable(sk))
1068 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1069
1070 return mask;
1071}
1072EXPORT_SYMBOL_GPL(af_alg_poll);
1073
1074/**
1075 * af_alg_alloc_areq - allocate struct af_alg_async_req
1076 *
1077 * @sk socket of connection to user space
1078 * @areqlen size of struct af_alg_async_req + crypto_*_reqsize
1079 * @return allocated data structure or ERR_PTR upon error
1080 */
1081struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
1082 unsigned int areqlen)
1083{
1084 struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
1085
1086 if (unlikely(!areq))
1087 return ERR_PTR(-ENOMEM);
1088
1089 areq->areqlen = areqlen;
1090 areq->sk = sk;
1091 areq->last_rsgl = NULL;
1092 INIT_LIST_HEAD(&areq->rsgl_list);
1093 areq->tsgl = NULL;
1094 areq->tsgl_entries = 0;
1095
1096 return areq;
1097}
1098EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
1099
1100/**
1101 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1102 * operation
1103 *
1104 * @sk socket of connection to user space
1105 * @msg user space message
1106 * @flags flags used to invoke recvmsg with
1107 * @areq instance of the cryptographic request that will hold the RX SGL
1108 * @maxsize maximum number of bytes to be pulled from user space
1109 * @outlen number of bytes in the RX SGL
1110 * @return 0 on success, < 0 upon error
1111 */
1112int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
1113 struct af_alg_async_req *areq, size_t maxsize,
1114 size_t *outlen)
1115{
1116 struct alg_sock *ask = alg_sk(sk);
1117 struct af_alg_ctx *ctx = ask->private;
1118 size_t len = 0;
1119
1120 while (maxsize > len && msg_data_left(msg)) {
1121 struct af_alg_rsgl *rsgl;
1122 size_t seglen;
1123 int err;
1124
1125 /* limit the amount of readable buffers */
1126 if (!af_alg_readable(sk))
1127 break;
1128
1129 seglen = min_t(size_t, (maxsize - len),
1130 msg_data_left(msg));
1131
1132 if (list_empty(&areq->rsgl_list)) {
1133 rsgl = &areq->first_rsgl;
1134 } else {
1135 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
1136 if (unlikely(!rsgl))
1137 return -ENOMEM;
1138 }
1139
1140 rsgl->sgl.npages = 0;
1141 list_add_tail(&rsgl->list, &areq->rsgl_list);
1142
1143 /* make one iovec available as scatterlist */
1144 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
1145 if (err < 0) {
1146 rsgl->sg_num_bytes = 0;
1147 return err;
1148 }
1149
1150 /* chain the new scatterlist with previous one */
1151 if (areq->last_rsgl)
1152 af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
1153
1154 areq->last_rsgl = rsgl;
1155 len += err;
1156 atomic_add(err, &ctx->rcvused);
1157 rsgl->sg_num_bytes = err;
1158 iov_iter_advance(&msg->msg_iter, err);
1159 }
1160
1161 *outlen = len;
1162 return 0;
1163}
1164EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
1165
1166static int __init af_alg_init(void)
1167{
1168 int err = proto_register(&alg_proto, 0);
1169
1170 if (err)
1171 goto out;
1172
1173 err = sock_register(&alg_family);
1174 if (err != 0)
1175 goto out_unregister_proto;
1176
1177out:
1178 return err;
1179
1180out_unregister_proto:
1181 proto_unregister(&alg_proto);
1182 goto out;
1183}
1184
1185static void __exit af_alg_exit(void)
1186{
1187 sock_unregister(PF_ALG);
1188 proto_unregister(&alg_proto);
1189}
1190
1191module_init(af_alg_init);
1192module_exit(af_alg_exit);
1193MODULE_LICENSE("GPL");
1194MODULE_ALIAS_NETPROTO(AF_ALG);