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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);
1/*
2 * af_alg: User-space algorithm interface
3 *
4 * This file provides the user-space API for algorithms.
5 *
6 * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the Free
10 * Software Foundation; either version 2 of the License, or (at your option)
11 * any later version.
12 *
13 */
14
15#include <linux/atomic.h>
16#include <crypto/if_alg.h>
17#include <linux/crypto.h>
18#include <linux/init.h>
19#include <linux/kernel.h>
20#include <linux/list.h>
21#include <linux/module.h>
22#include <linux/net.h>
23#include <linux/rwsem.h>
24#include <linux/sched/signal.h>
25#include <linux/security.h>
26
27struct alg_type_list {
28 const struct af_alg_type *type;
29 struct list_head list;
30};
31
32static atomic_long_t alg_memory_allocated;
33
34static struct proto alg_proto = {
35 .name = "ALG",
36 .owner = THIS_MODULE,
37 .memory_allocated = &alg_memory_allocated,
38 .obj_size = sizeof(struct alg_sock),
39};
40
41static LIST_HEAD(alg_types);
42static DECLARE_RWSEM(alg_types_sem);
43
44static const struct af_alg_type *alg_get_type(const char *name)
45{
46 const struct af_alg_type *type = ERR_PTR(-ENOENT);
47 struct alg_type_list *node;
48
49 down_read(&alg_types_sem);
50 list_for_each_entry(node, &alg_types, list) {
51 if (strcmp(node->type->name, name))
52 continue;
53
54 if (try_module_get(node->type->owner))
55 type = node->type;
56 break;
57 }
58 up_read(&alg_types_sem);
59
60 return type;
61}
62
63int af_alg_register_type(const struct af_alg_type *type)
64{
65 struct alg_type_list *node;
66 int err = -EEXIST;
67
68 down_write(&alg_types_sem);
69 list_for_each_entry(node, &alg_types, list) {
70 if (!strcmp(node->type->name, type->name))
71 goto unlock;
72 }
73
74 node = kmalloc(sizeof(*node), GFP_KERNEL);
75 err = -ENOMEM;
76 if (!node)
77 goto unlock;
78
79 type->ops->owner = THIS_MODULE;
80 if (type->ops_nokey)
81 type->ops_nokey->owner = THIS_MODULE;
82 node->type = type;
83 list_add(&node->list, &alg_types);
84 err = 0;
85
86unlock:
87 up_write(&alg_types_sem);
88
89 return err;
90}
91EXPORT_SYMBOL_GPL(af_alg_register_type);
92
93int af_alg_unregister_type(const struct af_alg_type *type)
94{
95 struct alg_type_list *node;
96 int err = -ENOENT;
97
98 down_write(&alg_types_sem);
99 list_for_each_entry(node, &alg_types, list) {
100 if (strcmp(node->type->name, type->name))
101 continue;
102
103 list_del(&node->list);
104 kfree(node);
105 err = 0;
106 break;
107 }
108 up_write(&alg_types_sem);
109
110 return err;
111}
112EXPORT_SYMBOL_GPL(af_alg_unregister_type);
113
114static void alg_do_release(const struct af_alg_type *type, void *private)
115{
116 if (!type)
117 return;
118
119 type->release(private);
120 module_put(type->owner);
121}
122
123int af_alg_release(struct socket *sock)
124{
125 if (sock->sk)
126 sock_put(sock->sk);
127 return 0;
128}
129EXPORT_SYMBOL_GPL(af_alg_release);
130
131void af_alg_release_parent(struct sock *sk)
132{
133 struct alg_sock *ask = alg_sk(sk);
134 unsigned int nokey = ask->nokey_refcnt;
135 bool last = nokey && !ask->refcnt;
136
137 sk = ask->parent;
138 ask = alg_sk(sk);
139
140 lock_sock(sk);
141 ask->nokey_refcnt -= nokey;
142 if (!last)
143 last = !--ask->refcnt;
144 release_sock(sk);
145
146 if (last)
147 sock_put(sk);
148}
149EXPORT_SYMBOL_GPL(af_alg_release_parent);
150
151static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
152{
153 const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY;
154 struct sock *sk = sock->sk;
155 struct alg_sock *ask = alg_sk(sk);
156 struct sockaddr_alg *sa = (void *)uaddr;
157 const struct af_alg_type *type;
158 void *private;
159 int err;
160
161 if (sock->state == SS_CONNECTED)
162 return -EINVAL;
163
164 if (addr_len < sizeof(*sa))
165 return -EINVAL;
166
167 /* If caller uses non-allowed flag, return error. */
168 if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed))
169 return -EINVAL;
170
171 sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
172 sa->salg_name[sizeof(sa->salg_name) + addr_len - sizeof(*sa) - 1] = 0;
173
174 type = alg_get_type(sa->salg_type);
175 if (IS_ERR(type) && PTR_ERR(type) == -ENOENT) {
176 request_module("algif-%s", sa->salg_type);
177 type = alg_get_type(sa->salg_type);
178 }
179
180 if (IS_ERR(type))
181 return PTR_ERR(type);
182
183 private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask);
184 if (IS_ERR(private)) {
185 module_put(type->owner);
186 return PTR_ERR(private);
187 }
188
189 err = -EBUSY;
190 lock_sock(sk);
191 if (ask->refcnt | ask->nokey_refcnt)
192 goto unlock;
193
194 swap(ask->type, type);
195 swap(ask->private, private);
196
197 err = 0;
198
199unlock:
200 release_sock(sk);
201
202 alg_do_release(type, private);
203
204 return err;
205}
206
207static int alg_setkey(struct sock *sk, char __user *ukey,
208 unsigned int keylen)
209{
210 struct alg_sock *ask = alg_sk(sk);
211 const struct af_alg_type *type = ask->type;
212 u8 *key;
213 int err;
214
215 key = sock_kmalloc(sk, keylen, GFP_KERNEL);
216 if (!key)
217 return -ENOMEM;
218
219 err = -EFAULT;
220 if (copy_from_user(key, ukey, keylen))
221 goto out;
222
223 err = type->setkey(ask->private, key, keylen);
224
225out:
226 sock_kzfree_s(sk, key, keylen);
227
228 return err;
229}
230
231static int alg_setsockopt(struct socket *sock, int level, int optname,
232 char __user *optval, unsigned int optlen)
233{
234 struct sock *sk = sock->sk;
235 struct alg_sock *ask = alg_sk(sk);
236 const struct af_alg_type *type;
237 int err = -EBUSY;
238
239 lock_sock(sk);
240 if (ask->refcnt)
241 goto unlock;
242
243 type = ask->type;
244
245 err = -ENOPROTOOPT;
246 if (level != SOL_ALG || !type)
247 goto unlock;
248
249 switch (optname) {
250 case ALG_SET_KEY:
251 if (sock->state == SS_CONNECTED)
252 goto unlock;
253 if (!type->setkey)
254 goto unlock;
255
256 err = alg_setkey(sk, optval, optlen);
257 break;
258 case ALG_SET_AEAD_AUTHSIZE:
259 if (sock->state == SS_CONNECTED)
260 goto unlock;
261 if (!type->setauthsize)
262 goto unlock;
263 err = type->setauthsize(ask->private, optlen);
264 }
265
266unlock:
267 release_sock(sk);
268
269 return err;
270}
271
272int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern)
273{
274 struct alg_sock *ask = alg_sk(sk);
275 const struct af_alg_type *type;
276 struct sock *sk2;
277 unsigned int nokey;
278 int err;
279
280 lock_sock(sk);
281 type = ask->type;
282
283 err = -EINVAL;
284 if (!type)
285 goto unlock;
286
287 sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, kern);
288 err = -ENOMEM;
289 if (!sk2)
290 goto unlock;
291
292 sock_init_data(newsock, sk2);
293 security_sock_graft(sk2, newsock);
294 security_sk_clone(sk, sk2);
295
296 err = type->accept(ask->private, sk2);
297
298 nokey = err == -ENOKEY;
299 if (nokey && type->accept_nokey)
300 err = type->accept_nokey(ask->private, sk2);
301
302 if (err)
303 goto unlock;
304
305 sk2->sk_family = PF_ALG;
306
307 if (nokey || !ask->refcnt++)
308 sock_hold(sk);
309 ask->nokey_refcnt += nokey;
310 alg_sk(sk2)->parent = sk;
311 alg_sk(sk2)->type = type;
312 alg_sk(sk2)->nokey_refcnt = nokey;
313
314 newsock->ops = type->ops;
315 newsock->state = SS_CONNECTED;
316
317 if (nokey)
318 newsock->ops = type->ops_nokey;
319
320 err = 0;
321
322unlock:
323 release_sock(sk);
324
325 return err;
326}
327EXPORT_SYMBOL_GPL(af_alg_accept);
328
329static int alg_accept(struct socket *sock, struct socket *newsock, int flags,
330 bool kern)
331{
332 return af_alg_accept(sock->sk, newsock, kern);
333}
334
335static const struct proto_ops alg_proto_ops = {
336 .family = PF_ALG,
337 .owner = THIS_MODULE,
338
339 .connect = sock_no_connect,
340 .socketpair = sock_no_socketpair,
341 .getname = sock_no_getname,
342 .ioctl = sock_no_ioctl,
343 .listen = sock_no_listen,
344 .shutdown = sock_no_shutdown,
345 .getsockopt = sock_no_getsockopt,
346 .mmap = sock_no_mmap,
347 .sendpage = sock_no_sendpage,
348 .sendmsg = sock_no_sendmsg,
349 .recvmsg = sock_no_recvmsg,
350 .poll = sock_no_poll,
351
352 .bind = alg_bind,
353 .release = af_alg_release,
354 .setsockopt = alg_setsockopt,
355 .accept = alg_accept,
356};
357
358static void alg_sock_destruct(struct sock *sk)
359{
360 struct alg_sock *ask = alg_sk(sk);
361
362 alg_do_release(ask->type, ask->private);
363}
364
365static int alg_create(struct net *net, struct socket *sock, int protocol,
366 int kern)
367{
368 struct sock *sk;
369 int err;
370
371 if (sock->type != SOCK_SEQPACKET)
372 return -ESOCKTNOSUPPORT;
373 if (protocol != 0)
374 return -EPROTONOSUPPORT;
375
376 err = -ENOMEM;
377 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
378 if (!sk)
379 goto out;
380
381 sock->ops = &alg_proto_ops;
382 sock_init_data(sock, sk);
383
384 sk->sk_family = PF_ALG;
385 sk->sk_destruct = alg_sock_destruct;
386
387 return 0;
388out:
389 return err;
390}
391
392static const struct net_proto_family alg_family = {
393 .family = PF_ALG,
394 .create = alg_create,
395 .owner = THIS_MODULE,
396};
397
398int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
399{
400 size_t off;
401 ssize_t n;
402 int npages, i;
403
404 n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
405 if (n < 0)
406 return n;
407
408 npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT;
409 if (WARN_ON(npages == 0))
410 return -EINVAL;
411 /* Add one extra for linking */
412 sg_init_table(sgl->sg, npages + 1);
413
414 for (i = 0, len = n; i < npages; i++) {
415 int plen = min_t(int, len, PAGE_SIZE - off);
416
417 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
418
419 off = 0;
420 len -= plen;
421 }
422 sg_mark_end(sgl->sg + npages - 1);
423 sgl->npages = npages;
424
425 return n;
426}
427EXPORT_SYMBOL_GPL(af_alg_make_sg);
428
429void af_alg_link_sg(struct af_alg_sgl *sgl_prev, struct af_alg_sgl *sgl_new)
430{
431 sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
432 sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
433}
434EXPORT_SYMBOL_GPL(af_alg_link_sg);
435
436void af_alg_free_sg(struct af_alg_sgl *sgl)
437{
438 int i;
439
440 for (i = 0; i < sgl->npages; i++)
441 put_page(sgl->pages[i]);
442}
443EXPORT_SYMBOL_GPL(af_alg_free_sg);
444
445int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
446{
447 struct cmsghdr *cmsg;
448
449 for_each_cmsghdr(cmsg, msg) {
450 if (!CMSG_OK(msg, cmsg))
451 return -EINVAL;
452 if (cmsg->cmsg_level != SOL_ALG)
453 continue;
454
455 switch (cmsg->cmsg_type) {
456 case ALG_SET_IV:
457 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
458 return -EINVAL;
459 con->iv = (void *)CMSG_DATA(cmsg);
460 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
461 sizeof(*con->iv)))
462 return -EINVAL;
463 break;
464
465 case ALG_SET_OP:
466 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
467 return -EINVAL;
468 con->op = *(u32 *)CMSG_DATA(cmsg);
469 break;
470
471 case ALG_SET_AEAD_ASSOCLEN:
472 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
473 return -EINVAL;
474 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
475 break;
476
477 default:
478 return -EINVAL;
479 }
480 }
481
482 return 0;
483}
484EXPORT_SYMBOL_GPL(af_alg_cmsg_send);
485
486/**
487 * af_alg_alloc_tsgl - allocate the TX SGL
488 *
489 * @sk socket of connection to user space
490 * @return: 0 upon success, < 0 upon error
491 */
492int af_alg_alloc_tsgl(struct sock *sk)
493{
494 struct alg_sock *ask = alg_sk(sk);
495 struct af_alg_ctx *ctx = ask->private;
496 struct af_alg_tsgl *sgl;
497 struct scatterlist *sg = NULL;
498
499 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
500 if (!list_empty(&ctx->tsgl_list))
501 sg = sgl->sg;
502
503 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
504 sgl = sock_kmalloc(sk, sizeof(*sgl) +
505 sizeof(sgl->sg[0]) * (MAX_SGL_ENTS + 1),
506 GFP_KERNEL);
507 if (!sgl)
508 return -ENOMEM;
509
510 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
511 sgl->cur = 0;
512
513 if (sg)
514 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
515
516 list_add_tail(&sgl->list, &ctx->tsgl_list);
517 }
518
519 return 0;
520}
521EXPORT_SYMBOL_GPL(af_alg_alloc_tsgl);
522
523/**
524 * aead_count_tsgl - Count number of TX SG entries
525 *
526 * The counting starts from the beginning of the SGL to @bytes. If
527 * an offset is provided, the counting of the SG entries starts at the offset.
528 *
529 * @sk socket of connection to user space
530 * @bytes Count the number of SG entries holding given number of bytes.
531 * @offset Start the counting of SG entries from the given offset.
532 * @return Number of TX SG entries found given the constraints
533 */
534unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
535{
536 struct alg_sock *ask = alg_sk(sk);
537 struct af_alg_ctx *ctx = ask->private;
538 struct af_alg_tsgl *sgl, *tmp;
539 unsigned int i;
540 unsigned int sgl_count = 0;
541
542 if (!bytes)
543 return 0;
544
545 list_for_each_entry_safe(sgl, tmp, &ctx->tsgl_list, list) {
546 struct scatterlist *sg = sgl->sg;
547
548 for (i = 0; i < sgl->cur; i++) {
549 size_t bytes_count;
550
551 /* Skip offset */
552 if (offset >= sg[i].length) {
553 offset -= sg[i].length;
554 bytes -= sg[i].length;
555 continue;
556 }
557
558 bytes_count = sg[i].length - offset;
559
560 offset = 0;
561 sgl_count++;
562
563 /* If we have seen requested number of bytes, stop */
564 if (bytes_count >= bytes)
565 return sgl_count;
566
567 bytes -= bytes_count;
568 }
569 }
570
571 return sgl_count;
572}
573EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
574
575/**
576 * aead_pull_tsgl - Release the specified buffers from TX SGL
577 *
578 * If @dst is non-null, reassign the pages to dst. The caller must release
579 * the pages. If @dst_offset is given only reassign the pages to @dst starting
580 * at the @dst_offset (byte). The caller must ensure that @dst is large
581 * enough (e.g. by using af_alg_count_tsgl with the same offset).
582 *
583 * @sk socket of connection to user space
584 * @used Number of bytes to pull from TX SGL
585 * @dst If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
586 * caller must release the buffers in dst.
587 * @dst_offset Reassign the TX SGL from given offset. All buffers before
588 * reaching the offset is released.
589 */
590void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
591 size_t dst_offset)
592{
593 struct alg_sock *ask = alg_sk(sk);
594 struct af_alg_ctx *ctx = ask->private;
595 struct af_alg_tsgl *sgl;
596 struct scatterlist *sg;
597 unsigned int i, j = 0;
598
599 while (!list_empty(&ctx->tsgl_list)) {
600 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
601 list);
602 sg = sgl->sg;
603
604 for (i = 0; i < sgl->cur; i++) {
605 size_t plen = min_t(size_t, used, sg[i].length);
606 struct page *page = sg_page(sg + i);
607
608 if (!page)
609 continue;
610
611 /*
612 * Assumption: caller created af_alg_count_tsgl(len)
613 * SG entries in dst.
614 */
615 if (dst) {
616 if (dst_offset >= plen) {
617 /* discard page before offset */
618 dst_offset -= plen;
619 } else {
620 /* reassign page to dst after offset */
621 get_page(page);
622 sg_set_page(dst + j, page,
623 plen - dst_offset,
624 sg[i].offset + dst_offset);
625 dst_offset = 0;
626 j++;
627 }
628 }
629
630 sg[i].length -= plen;
631 sg[i].offset += plen;
632
633 used -= plen;
634 ctx->used -= plen;
635
636 if (sg[i].length)
637 return;
638
639 put_page(page);
640 sg_assign_page(sg + i, NULL);
641 }
642
643 list_del(&sgl->list);
644 sock_kfree_s(sk, sgl, sizeof(*sgl) + sizeof(sgl->sg[0]) *
645 (MAX_SGL_ENTS + 1));
646 }
647
648 if (!ctx->used)
649 ctx->merge = 0;
650}
651EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
652
653/**
654 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
655 *
656 * @areq Request holding the TX and RX SGL
657 */
658void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
659{
660 struct sock *sk = areq->sk;
661 struct alg_sock *ask = alg_sk(sk);
662 struct af_alg_ctx *ctx = ask->private;
663 struct af_alg_rsgl *rsgl, *tmp;
664 struct scatterlist *tsgl;
665 struct scatterlist *sg;
666 unsigned int i;
667
668 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
669 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
670 af_alg_free_sg(&rsgl->sgl);
671 list_del(&rsgl->list);
672 if (rsgl != &areq->first_rsgl)
673 sock_kfree_s(sk, rsgl, sizeof(*rsgl));
674 }
675
676 tsgl = areq->tsgl;
677 if (tsgl) {
678 for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
679 if (!sg_page(sg))
680 continue;
681 put_page(sg_page(sg));
682 }
683
684 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
685 }
686}
687EXPORT_SYMBOL_GPL(af_alg_free_areq_sgls);
688
689/**
690 * af_alg_wait_for_wmem - wait for availability of writable memory
691 *
692 * @sk socket of connection to user space
693 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
694 * @return 0 when writable memory is available, < 0 upon error
695 */
696int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
697{
698 DEFINE_WAIT_FUNC(wait, woken_wake_function);
699 int err = -ERESTARTSYS;
700 long timeout;
701
702 if (flags & MSG_DONTWAIT)
703 return -EAGAIN;
704
705 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
706
707 add_wait_queue(sk_sleep(sk), &wait);
708 for (;;) {
709 if (signal_pending(current))
710 break;
711 timeout = MAX_SCHEDULE_TIMEOUT;
712 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
713 err = 0;
714 break;
715 }
716 }
717 remove_wait_queue(sk_sleep(sk), &wait);
718
719 return err;
720}
721EXPORT_SYMBOL_GPL(af_alg_wait_for_wmem);
722
723/**
724 * af_alg_wmem_wakeup - wakeup caller when writable memory is available
725 *
726 * @sk socket of connection to user space
727 */
728void af_alg_wmem_wakeup(struct sock *sk)
729{
730 struct socket_wq *wq;
731
732 if (!af_alg_writable(sk))
733 return;
734
735 rcu_read_lock();
736 wq = rcu_dereference(sk->sk_wq);
737 if (skwq_has_sleeper(wq))
738 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN |
739 EPOLLRDNORM |
740 EPOLLRDBAND);
741 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
742 rcu_read_unlock();
743}
744EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
745
746/**
747 * af_alg_wait_for_data - wait for availability of TX data
748 *
749 * @sk socket of connection to user space
750 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
751 * @return 0 when writable memory is available, < 0 upon error
752 */
753int af_alg_wait_for_data(struct sock *sk, unsigned flags)
754{
755 DEFINE_WAIT_FUNC(wait, woken_wake_function);
756 struct alg_sock *ask = alg_sk(sk);
757 struct af_alg_ctx *ctx = ask->private;
758 long timeout;
759 int err = -ERESTARTSYS;
760
761 if (flags & MSG_DONTWAIT)
762 return -EAGAIN;
763
764 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
765
766 add_wait_queue(sk_sleep(sk), &wait);
767 for (;;) {
768 if (signal_pending(current))
769 break;
770 timeout = MAX_SCHEDULE_TIMEOUT;
771 if (sk_wait_event(sk, &timeout, (ctx->used || !ctx->more),
772 &wait)) {
773 err = 0;
774 break;
775 }
776 }
777 remove_wait_queue(sk_sleep(sk), &wait);
778
779 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
780
781 return err;
782}
783EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
784
785/**
786 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
787 *
788 * @sk socket of connection to user space
789 */
790
791void af_alg_data_wakeup(struct sock *sk)
792{
793 struct alg_sock *ask = alg_sk(sk);
794 struct af_alg_ctx *ctx = ask->private;
795 struct socket_wq *wq;
796
797 if (!ctx->used)
798 return;
799
800 rcu_read_lock();
801 wq = rcu_dereference(sk->sk_wq);
802 if (skwq_has_sleeper(wq))
803 wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
804 EPOLLRDNORM |
805 EPOLLRDBAND);
806 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
807 rcu_read_unlock();
808}
809EXPORT_SYMBOL_GPL(af_alg_data_wakeup);
810
811/**
812 * af_alg_sendmsg - implementation of sendmsg system call handler
813 *
814 * The sendmsg system call handler obtains the user data and stores it
815 * in ctx->tsgl_list. This implies allocation of the required numbers of
816 * struct af_alg_tsgl.
817 *
818 * In addition, the ctx is filled with the information sent via CMSG.
819 *
820 * @sock socket of connection to user space
821 * @msg message from user space
822 * @size size of message from user space
823 * @ivsize the size of the IV for the cipher operation to verify that the
824 * user-space-provided IV has the right size
825 * @return the number of copied data upon success, < 0 upon error
826 */
827int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
828 unsigned int ivsize)
829{
830 struct sock *sk = sock->sk;
831 struct alg_sock *ask = alg_sk(sk);
832 struct af_alg_ctx *ctx = ask->private;
833 struct af_alg_tsgl *sgl;
834 struct af_alg_control con = {};
835 long copied = 0;
836 bool enc = 0;
837 bool init = 0;
838 int err = 0;
839
840 if (msg->msg_controllen) {
841 err = af_alg_cmsg_send(msg, &con);
842 if (err)
843 return err;
844
845 init = 1;
846 switch (con.op) {
847 case ALG_OP_ENCRYPT:
848 enc = 1;
849 break;
850 case ALG_OP_DECRYPT:
851 enc = 0;
852 break;
853 default:
854 return -EINVAL;
855 }
856
857 if (con.iv && con.iv->ivlen != ivsize)
858 return -EINVAL;
859 }
860
861 lock_sock(sk);
862 if (!ctx->more && ctx->used) {
863 err = -EINVAL;
864 goto unlock;
865 }
866
867 if (init) {
868 ctx->enc = enc;
869 if (con.iv)
870 memcpy(ctx->iv, con.iv->iv, ivsize);
871
872 ctx->aead_assoclen = con.aead_assoclen;
873 }
874
875 while (size) {
876 struct scatterlist *sg;
877 size_t len = size;
878 size_t plen;
879
880 /* use the existing memory in an allocated page */
881 if (ctx->merge) {
882 sgl = list_entry(ctx->tsgl_list.prev,
883 struct af_alg_tsgl, list);
884 sg = sgl->sg + sgl->cur - 1;
885 len = min_t(size_t, len,
886 PAGE_SIZE - sg->offset - sg->length);
887
888 err = memcpy_from_msg(page_address(sg_page(sg)) +
889 sg->offset + sg->length,
890 msg, len);
891 if (err)
892 goto unlock;
893
894 sg->length += len;
895 ctx->merge = (sg->offset + sg->length) &
896 (PAGE_SIZE - 1);
897
898 ctx->used += len;
899 copied += len;
900 size -= len;
901 continue;
902 }
903
904 if (!af_alg_writable(sk)) {
905 err = af_alg_wait_for_wmem(sk, msg->msg_flags);
906 if (err)
907 goto unlock;
908 }
909
910 /* allocate a new page */
911 len = min_t(unsigned long, len, af_alg_sndbuf(sk));
912
913 err = af_alg_alloc_tsgl(sk);
914 if (err)
915 goto unlock;
916
917 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
918 list);
919 sg = sgl->sg;
920 if (sgl->cur)
921 sg_unmark_end(sg + sgl->cur - 1);
922
923 do {
924 unsigned int i = sgl->cur;
925
926 plen = min_t(size_t, len, PAGE_SIZE);
927
928 sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
929 if (!sg_page(sg + i)) {
930 err = -ENOMEM;
931 goto unlock;
932 }
933
934 err = memcpy_from_msg(page_address(sg_page(sg + i)),
935 msg, plen);
936 if (err) {
937 __free_page(sg_page(sg + i));
938 sg_assign_page(sg + i, NULL);
939 goto unlock;
940 }
941
942 sg[i].length = plen;
943 len -= plen;
944 ctx->used += plen;
945 copied += plen;
946 size -= plen;
947 sgl->cur++;
948 } while (len && sgl->cur < MAX_SGL_ENTS);
949
950 if (!size)
951 sg_mark_end(sg + sgl->cur - 1);
952
953 ctx->merge = plen & (PAGE_SIZE - 1);
954 }
955
956 err = 0;
957
958 ctx->more = msg->msg_flags & MSG_MORE;
959
960unlock:
961 af_alg_data_wakeup(sk);
962 release_sock(sk);
963
964 return copied ?: err;
965}
966EXPORT_SYMBOL_GPL(af_alg_sendmsg);
967
968/**
969 * af_alg_sendpage - sendpage system call handler
970 *
971 * This is a generic implementation of sendpage to fill ctx->tsgl_list.
972 */
973ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
974 int offset, size_t size, int flags)
975{
976 struct sock *sk = sock->sk;
977 struct alg_sock *ask = alg_sk(sk);
978 struct af_alg_ctx *ctx = ask->private;
979 struct af_alg_tsgl *sgl;
980 int err = -EINVAL;
981
982 if (flags & MSG_SENDPAGE_NOTLAST)
983 flags |= MSG_MORE;
984
985 lock_sock(sk);
986 if (!ctx->more && ctx->used)
987 goto unlock;
988
989 if (!size)
990 goto done;
991
992 if (!af_alg_writable(sk)) {
993 err = af_alg_wait_for_wmem(sk, flags);
994 if (err)
995 goto unlock;
996 }
997
998 err = af_alg_alloc_tsgl(sk);
999 if (err)
1000 goto unlock;
1001
1002 ctx->merge = 0;
1003 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
1004
1005 if (sgl->cur)
1006 sg_unmark_end(sgl->sg + sgl->cur - 1);
1007
1008 sg_mark_end(sgl->sg + sgl->cur);
1009
1010 get_page(page);
1011 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
1012 sgl->cur++;
1013 ctx->used += size;
1014
1015done:
1016 ctx->more = flags & MSG_MORE;
1017
1018unlock:
1019 af_alg_data_wakeup(sk);
1020 release_sock(sk);
1021
1022 return err ?: size;
1023}
1024EXPORT_SYMBOL_GPL(af_alg_sendpage);
1025
1026/**
1027 * af_alg_free_resources - release resources required for crypto request
1028 */
1029void af_alg_free_resources(struct af_alg_async_req *areq)
1030{
1031 struct sock *sk = areq->sk;
1032
1033 af_alg_free_areq_sgls(areq);
1034 sock_kfree_s(sk, areq, areq->areqlen);
1035}
1036EXPORT_SYMBOL_GPL(af_alg_free_resources);
1037
1038/**
1039 * af_alg_async_cb - AIO callback handler
1040 *
1041 * This handler cleans up the struct af_alg_async_req upon completion of the
1042 * AIO operation.
1043 *
1044 * The number of bytes to be generated with the AIO operation must be set
1045 * in areq->outlen before the AIO callback handler is invoked.
1046 */
1047void af_alg_async_cb(struct crypto_async_request *_req, int err)
1048{
1049 struct af_alg_async_req *areq = _req->data;
1050 struct sock *sk = areq->sk;
1051 struct kiocb *iocb = areq->iocb;
1052 unsigned int resultlen;
1053
1054 /* Buffer size written by crypto operation. */
1055 resultlen = areq->outlen;
1056
1057 af_alg_free_resources(areq);
1058 sock_put(sk);
1059
1060 iocb->ki_complete(iocb, err ? err : resultlen, 0);
1061}
1062EXPORT_SYMBOL_GPL(af_alg_async_cb);
1063
1064/**
1065 * af_alg_poll - poll system call handler
1066 */
1067__poll_t af_alg_poll(struct file *file, struct socket *sock,
1068 poll_table *wait)
1069{
1070 struct sock *sk = sock->sk;
1071 struct alg_sock *ask = alg_sk(sk);
1072 struct af_alg_ctx *ctx = ask->private;
1073 __poll_t mask;
1074
1075 sock_poll_wait(file, sk_sleep(sk), wait);
1076 mask = 0;
1077
1078 if (!ctx->more || ctx->used)
1079 mask |= EPOLLIN | EPOLLRDNORM;
1080
1081 if (af_alg_writable(sk))
1082 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1083
1084 return mask;
1085}
1086EXPORT_SYMBOL_GPL(af_alg_poll);
1087
1088/**
1089 * af_alg_alloc_areq - allocate struct af_alg_async_req
1090 *
1091 * @sk socket of connection to user space
1092 * @areqlen size of struct af_alg_async_req + crypto_*_reqsize
1093 * @return allocated data structure or ERR_PTR upon error
1094 */
1095struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
1096 unsigned int areqlen)
1097{
1098 struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
1099
1100 if (unlikely(!areq))
1101 return ERR_PTR(-ENOMEM);
1102
1103 areq->areqlen = areqlen;
1104 areq->sk = sk;
1105 areq->last_rsgl = NULL;
1106 INIT_LIST_HEAD(&areq->rsgl_list);
1107 areq->tsgl = NULL;
1108 areq->tsgl_entries = 0;
1109
1110 return areq;
1111}
1112EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
1113
1114/**
1115 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1116 * operation
1117 *
1118 * @sk socket of connection to user space
1119 * @msg user space message
1120 * @flags flags used to invoke recvmsg with
1121 * @areq instance of the cryptographic request that will hold the RX SGL
1122 * @maxsize maximum number of bytes to be pulled from user space
1123 * @outlen number of bytes in the RX SGL
1124 * @return 0 on success, < 0 upon error
1125 */
1126int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
1127 struct af_alg_async_req *areq, size_t maxsize,
1128 size_t *outlen)
1129{
1130 struct alg_sock *ask = alg_sk(sk);
1131 struct af_alg_ctx *ctx = ask->private;
1132 size_t len = 0;
1133
1134 while (maxsize > len && msg_data_left(msg)) {
1135 struct af_alg_rsgl *rsgl;
1136 size_t seglen;
1137 int err;
1138
1139 /* limit the amount of readable buffers */
1140 if (!af_alg_readable(sk))
1141 break;
1142
1143 seglen = min_t(size_t, (maxsize - len),
1144 msg_data_left(msg));
1145
1146 if (list_empty(&areq->rsgl_list)) {
1147 rsgl = &areq->first_rsgl;
1148 } else {
1149 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
1150 if (unlikely(!rsgl))
1151 return -ENOMEM;
1152 }
1153
1154 rsgl->sgl.npages = 0;
1155 list_add_tail(&rsgl->list, &areq->rsgl_list);
1156
1157 /* make one iovec available as scatterlist */
1158 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
1159 if (err < 0)
1160 return err;
1161
1162 /* chain the new scatterlist with previous one */
1163 if (areq->last_rsgl)
1164 af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
1165
1166 areq->last_rsgl = rsgl;
1167 len += err;
1168 atomic_add(err, &ctx->rcvused);
1169 rsgl->sg_num_bytes = err;
1170 iov_iter_advance(&msg->msg_iter, err);
1171 }
1172
1173 *outlen = len;
1174 return 0;
1175}
1176EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
1177
1178static int __init af_alg_init(void)
1179{
1180 int err = proto_register(&alg_proto, 0);
1181
1182 if (err)
1183 goto out;
1184
1185 err = sock_register(&alg_family);
1186 if (err != 0)
1187 goto out_unregister_proto;
1188
1189out:
1190 return err;
1191
1192out_unregister_proto:
1193 proto_unregister(&alg_proto);
1194 goto out;
1195}
1196
1197static void __exit af_alg_exit(void)
1198{
1199 sock_unregister(PF_ALG);
1200 proto_unregister(&alg_proto);
1201}
1202
1203module_init(af_alg_init);
1204module_exit(af_alg_exit);
1205MODULE_LICENSE("GPL");
1206MODULE_ALIAS_NETPROTO(AF_ALG);