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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);
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_new *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 BUILD_BUG_ON(offsetof(struct sockaddr_alg_new, salg_name) !=
159 offsetof(struct sockaddr_alg, salg_name));
160 BUILD_BUG_ON(offsetof(struct sockaddr_alg, salg_name) != sizeof(*sa));
161
162 if (addr_len < sizeof(*sa) + 1)
163 return -EINVAL;
164
165 /* If caller uses non-allowed flag, return error. */
166 if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed))
167 return -EINVAL;
168
169 sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
170 sa->salg_name[addr_len - sizeof(*sa) - 1] = 0;
171
172 type = alg_get_type(sa->salg_type);
173 if (PTR_ERR(type) == -ENOENT) {
174 request_module("algif-%s", sa->salg_type);
175 type = alg_get_type(sa->salg_type);
176 }
177
178 if (IS_ERR(type))
179 return PTR_ERR(type);
180
181 private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask);
182 if (IS_ERR(private)) {
183 module_put(type->owner);
184 return PTR_ERR(private);
185 }
186
187 err = -EBUSY;
188 lock_sock(sk);
189 if (atomic_read(&ask->refcnt))
190 goto unlock;
191
192 swap(ask->type, type);
193 swap(ask->private, private);
194
195 err = 0;
196
197unlock:
198 release_sock(sk);
199
200 alg_do_release(type, private);
201
202 return err;
203}
204
205static int alg_setkey(struct sock *sk, sockptr_t ukey, 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_sockptr(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 sockptr_t 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 (atomic_read(&ask->refcnt) != atomic_read(&ask->nokey_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 break;
262 case ALG_SET_DRBG_ENTROPY:
263 if (sock->state == SS_CONNECTED)
264 goto unlock;
265 if (!type->setentropy)
266 goto unlock;
267
268 err = type->setentropy(ask->private, optval, optlen);
269 }
270
271unlock:
272 release_sock(sk);
273
274 return err;
275}
276
277int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern)
278{
279 struct alg_sock *ask = alg_sk(sk);
280 const struct af_alg_type *type;
281 struct sock *sk2;
282 unsigned int nokey;
283 int err;
284
285 lock_sock(sk);
286 type = ask->type;
287
288 err = -EINVAL;
289 if (!type)
290 goto unlock;
291
292 sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, kern);
293 err = -ENOMEM;
294 if (!sk2)
295 goto unlock;
296
297 sock_init_data(newsock, sk2);
298 security_sock_graft(sk2, newsock);
299 security_sk_clone(sk, sk2);
300
301 /*
302 * newsock->ops assigned here to allow type->accept call to override
303 * them when required.
304 */
305 newsock->ops = type->ops;
306 err = type->accept(ask->private, sk2);
307
308 nokey = err == -ENOKEY;
309 if (nokey && type->accept_nokey)
310 err = type->accept_nokey(ask->private, sk2);
311
312 if (err)
313 goto unlock;
314
315 if (atomic_inc_return_relaxed(&ask->refcnt) == 1)
316 sock_hold(sk);
317 if (nokey) {
318 atomic_inc(&ask->nokey_refcnt);
319 atomic_set(&alg_sk(sk2)->nokey_refcnt, 1);
320 }
321 alg_sk(sk2)->parent = sk;
322 alg_sk(sk2)->type = type;
323
324 newsock->state = SS_CONNECTED;
325
326 if (nokey)
327 newsock->ops = type->ops_nokey;
328
329 err = 0;
330
331unlock:
332 release_sock(sk);
333
334 return err;
335}
336EXPORT_SYMBOL_GPL(af_alg_accept);
337
338static int alg_accept(struct socket *sock, struct socket *newsock, int flags,
339 bool kern)
340{
341 return af_alg_accept(sock->sk, newsock, kern);
342}
343
344static const struct proto_ops alg_proto_ops = {
345 .family = PF_ALG,
346 .owner = THIS_MODULE,
347
348 .connect = sock_no_connect,
349 .socketpair = sock_no_socketpair,
350 .getname = sock_no_getname,
351 .ioctl = sock_no_ioctl,
352 .listen = sock_no_listen,
353 .shutdown = sock_no_shutdown,
354 .mmap = sock_no_mmap,
355 .sendpage = sock_no_sendpage,
356 .sendmsg = sock_no_sendmsg,
357 .recvmsg = sock_no_recvmsg,
358
359 .bind = alg_bind,
360 .release = af_alg_release,
361 .setsockopt = alg_setsockopt,
362 .accept = alg_accept,
363};
364
365static void alg_sock_destruct(struct sock *sk)
366{
367 struct alg_sock *ask = alg_sk(sk);
368
369 alg_do_release(ask->type, ask->private);
370}
371
372static int alg_create(struct net *net, struct socket *sock, int protocol,
373 int kern)
374{
375 struct sock *sk;
376 int err;
377
378 if (sock->type != SOCK_SEQPACKET)
379 return -ESOCKTNOSUPPORT;
380 if (protocol != 0)
381 return -EPROTONOSUPPORT;
382
383 err = -ENOMEM;
384 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
385 if (!sk)
386 goto out;
387
388 sock->ops = &alg_proto_ops;
389 sock_init_data(sock, sk);
390
391 sk->sk_destruct = alg_sock_destruct;
392
393 return 0;
394out:
395 return err;
396}
397
398static const struct net_proto_family alg_family = {
399 .family = PF_ALG,
400 .create = alg_create,
401 .owner = THIS_MODULE,
402};
403
404int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
405{
406 size_t off;
407 ssize_t n;
408 int npages, i;
409
410 n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
411 if (n < 0)
412 return n;
413
414 npages = DIV_ROUND_UP(off + n, PAGE_SIZE);
415 if (WARN_ON(npages == 0))
416 return -EINVAL;
417 /* Add one extra for linking */
418 sg_init_table(sgl->sg, npages + 1);
419
420 for (i = 0, len = n; i < npages; i++) {
421 int plen = min_t(int, len, PAGE_SIZE - off);
422
423 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
424
425 off = 0;
426 len -= plen;
427 }
428 sg_mark_end(sgl->sg + npages - 1);
429 sgl->npages = npages;
430
431 return n;
432}
433EXPORT_SYMBOL_GPL(af_alg_make_sg);
434
435static void af_alg_link_sg(struct af_alg_sgl *sgl_prev,
436 struct af_alg_sgl *sgl_new)
437{
438 sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
439 sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
440}
441
442void af_alg_free_sg(struct af_alg_sgl *sgl)
443{
444 int i;
445
446 for (i = 0; i < sgl->npages; i++)
447 put_page(sgl->pages[i]);
448}
449EXPORT_SYMBOL_GPL(af_alg_free_sg);
450
451static int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
452{
453 struct cmsghdr *cmsg;
454
455 for_each_cmsghdr(cmsg, msg) {
456 if (!CMSG_OK(msg, cmsg))
457 return -EINVAL;
458 if (cmsg->cmsg_level != SOL_ALG)
459 continue;
460
461 switch (cmsg->cmsg_type) {
462 case ALG_SET_IV:
463 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
464 return -EINVAL;
465 con->iv = (void *)CMSG_DATA(cmsg);
466 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
467 sizeof(*con->iv)))
468 return -EINVAL;
469 break;
470
471 case ALG_SET_OP:
472 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
473 return -EINVAL;
474 con->op = *(u32 *)CMSG_DATA(cmsg);
475 break;
476
477 case ALG_SET_AEAD_ASSOCLEN:
478 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
479 return -EINVAL;
480 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
481 break;
482
483 default:
484 return -EINVAL;
485 }
486 }
487
488 return 0;
489}
490
491/**
492 * af_alg_alloc_tsgl - allocate the TX SGL
493 *
494 * @sk: socket of connection to user space
495 * Return: 0 upon success, < 0 upon error
496 */
497static int af_alg_alloc_tsgl(struct sock *sk)
498{
499 struct alg_sock *ask = alg_sk(sk);
500 struct af_alg_ctx *ctx = ask->private;
501 struct af_alg_tsgl *sgl;
502 struct scatterlist *sg = NULL;
503
504 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
505 if (!list_empty(&ctx->tsgl_list))
506 sg = sgl->sg;
507
508 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
509 sgl = sock_kmalloc(sk,
510 struct_size(sgl, sg, (MAX_SGL_ENTS + 1)),
511 GFP_KERNEL);
512 if (!sgl)
513 return -ENOMEM;
514
515 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
516 sgl->cur = 0;
517
518 if (sg)
519 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
520
521 list_add_tail(&sgl->list, &ctx->tsgl_list);
522 }
523
524 return 0;
525}
526
527/**
528 * af_alg_count_tsgl - Count number of TX SG entries
529 *
530 * The counting starts from the beginning of the SGL to @bytes. If
531 * an @offset is provided, the counting of the SG entries starts at the @offset.
532 *
533 * @sk: socket of connection to user space
534 * @bytes: Count the number of SG entries holding given number of bytes.
535 * @offset: Start the counting of SG entries from the given offset.
536 * Return: Number of TX SG entries found given the constraints
537 */
538unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
539{
540 const struct alg_sock *ask = alg_sk(sk);
541 const struct af_alg_ctx *ctx = ask->private;
542 const struct af_alg_tsgl *sgl;
543 unsigned int i;
544 unsigned int sgl_count = 0;
545
546 if (!bytes)
547 return 0;
548
549 list_for_each_entry(sgl, &ctx->tsgl_list, list) {
550 const struct scatterlist *sg = sgl->sg;
551
552 for (i = 0; i < sgl->cur; i++) {
553 size_t bytes_count;
554
555 /* Skip offset */
556 if (offset >= sg[i].length) {
557 offset -= sg[i].length;
558 bytes -= sg[i].length;
559 continue;
560 }
561
562 bytes_count = sg[i].length - offset;
563
564 offset = 0;
565 sgl_count++;
566
567 /* If we have seen requested number of bytes, stop */
568 if (bytes_count >= bytes)
569 return sgl_count;
570
571 bytes -= bytes_count;
572 }
573 }
574
575 return sgl_count;
576}
577EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
578
579/**
580 * af_alg_pull_tsgl - Release the specified buffers from TX SGL
581 *
582 * If @dst is non-null, reassign the pages to @dst. The caller must release
583 * the pages. If @dst_offset is given only reassign the pages to @dst starting
584 * at the @dst_offset (byte). The caller must ensure that @dst is large
585 * enough (e.g. by using af_alg_count_tsgl with the same offset).
586 *
587 * @sk: socket of connection to user space
588 * @used: Number of bytes to pull from TX SGL
589 * @dst: If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
590 * caller must release the buffers in dst.
591 * @dst_offset: Reassign the TX SGL from given offset. All buffers before
592 * reaching the offset is released.
593 */
594void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
595 size_t dst_offset)
596{
597 struct alg_sock *ask = alg_sk(sk);
598 struct af_alg_ctx *ctx = ask->private;
599 struct af_alg_tsgl *sgl;
600 struct scatterlist *sg;
601 unsigned int i, j = 0;
602
603 while (!list_empty(&ctx->tsgl_list)) {
604 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
605 list);
606 sg = sgl->sg;
607
608 for (i = 0; i < sgl->cur; i++) {
609 size_t plen = min_t(size_t, used, sg[i].length);
610 struct page *page = sg_page(sg + i);
611
612 if (!page)
613 continue;
614
615 /*
616 * Assumption: caller created af_alg_count_tsgl(len)
617 * SG entries in dst.
618 */
619 if (dst) {
620 if (dst_offset >= plen) {
621 /* discard page before offset */
622 dst_offset -= plen;
623 } else {
624 /* reassign page to dst after offset */
625 get_page(page);
626 sg_set_page(dst + j, page,
627 plen - dst_offset,
628 sg[i].offset + dst_offset);
629 dst_offset = 0;
630 j++;
631 }
632 }
633
634 sg[i].length -= plen;
635 sg[i].offset += plen;
636
637 used -= plen;
638 ctx->used -= plen;
639
640 if (sg[i].length)
641 return;
642
643 put_page(page);
644 sg_assign_page(sg + i, NULL);
645 }
646
647 list_del(&sgl->list);
648 sock_kfree_s(sk, sgl, struct_size(sgl, sg, MAX_SGL_ENTS + 1));
649 }
650
651 if (!ctx->used)
652 ctx->merge = 0;
653 ctx->init = ctx->more;
654}
655EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
656
657/**
658 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
659 *
660 * @areq: Request holding the TX and RX SGL
661 */
662static void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
663{
664 struct sock *sk = areq->sk;
665 struct alg_sock *ask = alg_sk(sk);
666 struct af_alg_ctx *ctx = ask->private;
667 struct af_alg_rsgl *rsgl, *tmp;
668 struct scatterlist *tsgl;
669 struct scatterlist *sg;
670 unsigned int i;
671
672 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
673 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
674 af_alg_free_sg(&rsgl->sgl);
675 list_del(&rsgl->list);
676 if (rsgl != &areq->first_rsgl)
677 sock_kfree_s(sk, rsgl, sizeof(*rsgl));
678 }
679
680 tsgl = areq->tsgl;
681 if (tsgl) {
682 for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
683 if (!sg_page(sg))
684 continue;
685 put_page(sg_page(sg));
686 }
687
688 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
689 }
690}
691
692/**
693 * af_alg_wait_for_wmem - wait for availability of writable memory
694 *
695 * @sk: socket of connection to user space
696 * @flags: If MSG_DONTWAIT is set, then only report if function would sleep
697 * Return: 0 when writable memory is available, < 0 upon error
698 */
699static int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
700{
701 DEFINE_WAIT_FUNC(wait, woken_wake_function);
702 int err = -ERESTARTSYS;
703 long timeout;
704
705 if (flags & MSG_DONTWAIT)
706 return -EAGAIN;
707
708 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
709
710 add_wait_queue(sk_sleep(sk), &wait);
711 for (;;) {
712 if (signal_pending(current))
713 break;
714 timeout = MAX_SCHEDULE_TIMEOUT;
715 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
716 err = 0;
717 break;
718 }
719 }
720 remove_wait_queue(sk_sleep(sk), &wait);
721
722 return err;
723}
724
725/**
726 * af_alg_wmem_wakeup - wakeup caller when writable memory is available
727 *
728 * @sk: socket of connection to user space
729 */
730void af_alg_wmem_wakeup(struct sock *sk)
731{
732 struct socket_wq *wq;
733
734 if (!af_alg_writable(sk))
735 return;
736
737 rcu_read_lock();
738 wq = rcu_dereference(sk->sk_wq);
739 if (skwq_has_sleeper(wq))
740 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN |
741 EPOLLRDNORM |
742 EPOLLRDBAND);
743 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
744 rcu_read_unlock();
745}
746EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
747
748/**
749 * af_alg_wait_for_data - wait for availability of TX data
750 *
751 * @sk: socket of connection to user space
752 * @flags: If MSG_DONTWAIT is set, then only report if function would sleep
753 * @min: Set to minimum request size if partial requests are allowed.
754 * Return: 0 when writable memory is available, < 0 upon error
755 */
756int af_alg_wait_for_data(struct sock *sk, unsigned flags, unsigned min)
757{
758 DEFINE_WAIT_FUNC(wait, woken_wake_function);
759 struct alg_sock *ask = alg_sk(sk);
760 struct af_alg_ctx *ctx = ask->private;
761 long timeout;
762 int err = -ERESTARTSYS;
763
764 if (flags & MSG_DONTWAIT)
765 return -EAGAIN;
766
767 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
768
769 add_wait_queue(sk_sleep(sk), &wait);
770 for (;;) {
771 if (signal_pending(current))
772 break;
773 timeout = MAX_SCHEDULE_TIMEOUT;
774 if (sk_wait_event(sk, &timeout,
775 ctx->init && (!ctx->more ||
776 (min && ctx->used >= min)),
777 &wait)) {
778 err = 0;
779 break;
780 }
781 }
782 remove_wait_queue(sk_sleep(sk), &wait);
783
784 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
785
786 return err;
787}
788EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
789
790/**
791 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
792 *
793 * @sk: socket of connection to user space
794 */
795static void af_alg_data_wakeup(struct sock *sk)
796{
797 struct alg_sock *ask = alg_sk(sk);
798 struct af_alg_ctx *ctx = ask->private;
799 struct socket_wq *wq;
800
801 if (!ctx->used)
802 return;
803
804 rcu_read_lock();
805 wq = rcu_dereference(sk->sk_wq);
806 if (skwq_has_sleeper(wq))
807 wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
808 EPOLLRDNORM |
809 EPOLLRDBAND);
810 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
811 rcu_read_unlock();
812}
813
814/**
815 * af_alg_sendmsg - implementation of sendmsg system call handler
816 *
817 * The sendmsg system call handler obtains the user data and stores it
818 * in ctx->tsgl_list. This implies allocation of the required numbers of
819 * struct af_alg_tsgl.
820 *
821 * In addition, the ctx is filled with the information sent via CMSG.
822 *
823 * @sock: socket of connection to user space
824 * @msg: message from user space
825 * @size: size of message from user space
826 * @ivsize: the size of the IV for the cipher operation to verify that the
827 * user-space-provided IV has the right size
828 * Return: the number of copied data upon success, < 0 upon error
829 */
830int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
831 unsigned int ivsize)
832{
833 struct sock *sk = sock->sk;
834 struct alg_sock *ask = alg_sk(sk);
835 struct af_alg_ctx *ctx = ask->private;
836 struct af_alg_tsgl *sgl;
837 struct af_alg_control con = {};
838 long copied = 0;
839 bool enc = false;
840 bool init = false;
841 int err = 0;
842
843 if (msg->msg_controllen) {
844 err = af_alg_cmsg_send(msg, &con);
845 if (err)
846 return err;
847
848 init = true;
849 switch (con.op) {
850 case ALG_OP_ENCRYPT:
851 enc = true;
852 break;
853 case ALG_OP_DECRYPT:
854 enc = false;
855 break;
856 default:
857 return -EINVAL;
858 }
859
860 if (con.iv && con.iv->ivlen != ivsize)
861 return -EINVAL;
862 }
863
864 lock_sock(sk);
865 if (ctx->init && !ctx->more) {
866 if (ctx->used) {
867 err = -EINVAL;
868 goto unlock;
869 }
870
871 pr_info_once(
872 "%s sent an empty control message without MSG_MORE.\n",
873 current->comm);
874 }
875 ctx->init = true;
876
877 if (init) {
878 ctx->enc = enc;
879 if (con.iv)
880 memcpy(ctx->iv, con.iv->iv, ivsize);
881
882 ctx->aead_assoclen = con.aead_assoclen;
883 }
884
885 while (size) {
886 struct scatterlist *sg;
887 size_t len = size;
888 size_t plen;
889
890 /* use the existing memory in an allocated page */
891 if (ctx->merge) {
892 sgl = list_entry(ctx->tsgl_list.prev,
893 struct af_alg_tsgl, list);
894 sg = sgl->sg + sgl->cur - 1;
895 len = min_t(size_t, len,
896 PAGE_SIZE - sg->offset - sg->length);
897
898 err = memcpy_from_msg(page_address(sg_page(sg)) +
899 sg->offset + sg->length,
900 msg, len);
901 if (err)
902 goto unlock;
903
904 sg->length += len;
905 ctx->merge = (sg->offset + sg->length) &
906 (PAGE_SIZE - 1);
907
908 ctx->used += len;
909 copied += len;
910 size -= len;
911 continue;
912 }
913
914 if (!af_alg_writable(sk)) {
915 err = af_alg_wait_for_wmem(sk, msg->msg_flags);
916 if (err)
917 goto unlock;
918 }
919
920 /* allocate a new page */
921 len = min_t(unsigned long, len, af_alg_sndbuf(sk));
922
923 err = af_alg_alloc_tsgl(sk);
924 if (err)
925 goto unlock;
926
927 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
928 list);
929 sg = sgl->sg;
930 if (sgl->cur)
931 sg_unmark_end(sg + sgl->cur - 1);
932
933 do {
934 unsigned int i = sgl->cur;
935
936 plen = min_t(size_t, len, PAGE_SIZE);
937
938 sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
939 if (!sg_page(sg + i)) {
940 err = -ENOMEM;
941 goto unlock;
942 }
943
944 err = memcpy_from_msg(page_address(sg_page(sg + i)),
945 msg, plen);
946 if (err) {
947 __free_page(sg_page(sg + i));
948 sg_assign_page(sg + i, NULL);
949 goto unlock;
950 }
951
952 sg[i].length = plen;
953 len -= plen;
954 ctx->used += plen;
955 copied += plen;
956 size -= plen;
957 sgl->cur++;
958 } while (len && sgl->cur < MAX_SGL_ENTS);
959
960 if (!size)
961 sg_mark_end(sg + sgl->cur - 1);
962
963 ctx->merge = plen & (PAGE_SIZE - 1);
964 }
965
966 err = 0;
967
968 ctx->more = msg->msg_flags & MSG_MORE;
969
970unlock:
971 af_alg_data_wakeup(sk);
972 release_sock(sk);
973
974 return copied ?: err;
975}
976EXPORT_SYMBOL_GPL(af_alg_sendmsg);
977
978/**
979 * af_alg_sendpage - sendpage system call handler
980 * @sock: socket of connection to user space to write to
981 * @page: data to send
982 * @offset: offset into page to begin sending
983 * @size: length of data
984 * @flags: message send/receive flags
985 *
986 * This is a generic implementation of sendpage to fill ctx->tsgl_list.
987 */
988ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
989 int offset, size_t size, int flags)
990{
991 struct sock *sk = sock->sk;
992 struct alg_sock *ask = alg_sk(sk);
993 struct af_alg_ctx *ctx = ask->private;
994 struct af_alg_tsgl *sgl;
995 int err = -EINVAL;
996
997 if (flags & MSG_SENDPAGE_NOTLAST)
998 flags |= MSG_MORE;
999
1000 lock_sock(sk);
1001 if (!ctx->more && ctx->used)
1002 goto unlock;
1003
1004 if (!size)
1005 goto done;
1006
1007 if (!af_alg_writable(sk)) {
1008 err = af_alg_wait_for_wmem(sk, flags);
1009 if (err)
1010 goto unlock;
1011 }
1012
1013 err = af_alg_alloc_tsgl(sk);
1014 if (err)
1015 goto unlock;
1016
1017 ctx->merge = 0;
1018 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
1019
1020 if (sgl->cur)
1021 sg_unmark_end(sgl->sg + sgl->cur - 1);
1022
1023 sg_mark_end(sgl->sg + sgl->cur);
1024
1025 get_page(page);
1026 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
1027 sgl->cur++;
1028 ctx->used += size;
1029
1030done:
1031 ctx->more = flags & MSG_MORE;
1032
1033unlock:
1034 af_alg_data_wakeup(sk);
1035 release_sock(sk);
1036
1037 return err ?: size;
1038}
1039EXPORT_SYMBOL_GPL(af_alg_sendpage);
1040
1041/**
1042 * af_alg_free_resources - release resources required for crypto request
1043 * @areq: Request holding the TX and RX SGL
1044 */
1045void af_alg_free_resources(struct af_alg_async_req *areq)
1046{
1047 struct sock *sk = areq->sk;
1048
1049 af_alg_free_areq_sgls(areq);
1050 sock_kfree_s(sk, areq, areq->areqlen);
1051}
1052EXPORT_SYMBOL_GPL(af_alg_free_resources);
1053
1054/**
1055 * af_alg_async_cb - AIO callback handler
1056 * @_req: async request info
1057 * @err: if non-zero, error result to be returned via ki_complete();
1058 * otherwise return the AIO output length via ki_complete().
1059 *
1060 * This handler cleans up the struct af_alg_async_req upon completion of the
1061 * AIO operation.
1062 *
1063 * The number of bytes to be generated with the AIO operation must be set
1064 * in areq->outlen before the AIO callback handler is invoked.
1065 */
1066void af_alg_async_cb(struct crypto_async_request *_req, int err)
1067{
1068 struct af_alg_async_req *areq = _req->data;
1069 struct sock *sk = areq->sk;
1070 struct kiocb *iocb = areq->iocb;
1071 unsigned int resultlen;
1072
1073 /* Buffer size written by crypto operation. */
1074 resultlen = areq->outlen;
1075
1076 af_alg_free_resources(areq);
1077 sock_put(sk);
1078
1079 iocb->ki_complete(iocb, err ? err : (int)resultlen, 0);
1080}
1081EXPORT_SYMBOL_GPL(af_alg_async_cb);
1082
1083/**
1084 * af_alg_poll - poll system call handler
1085 * @file: file pointer
1086 * @sock: socket to poll
1087 * @wait: poll_table
1088 */
1089__poll_t af_alg_poll(struct file *file, struct socket *sock,
1090 poll_table *wait)
1091{
1092 struct sock *sk = sock->sk;
1093 struct alg_sock *ask = alg_sk(sk);
1094 struct af_alg_ctx *ctx = ask->private;
1095 __poll_t mask;
1096
1097 sock_poll_wait(file, sock, wait);
1098 mask = 0;
1099
1100 if (!ctx->more || ctx->used)
1101 mask |= EPOLLIN | EPOLLRDNORM;
1102
1103 if (af_alg_writable(sk))
1104 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1105
1106 return mask;
1107}
1108EXPORT_SYMBOL_GPL(af_alg_poll);
1109
1110/**
1111 * af_alg_alloc_areq - allocate struct af_alg_async_req
1112 *
1113 * @sk: socket of connection to user space
1114 * @areqlen: size of struct af_alg_async_req + crypto_*_reqsize
1115 * Return: allocated data structure or ERR_PTR upon error
1116 */
1117struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
1118 unsigned int areqlen)
1119{
1120 struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
1121
1122 if (unlikely(!areq))
1123 return ERR_PTR(-ENOMEM);
1124
1125 areq->areqlen = areqlen;
1126 areq->sk = sk;
1127 areq->last_rsgl = NULL;
1128 INIT_LIST_HEAD(&areq->rsgl_list);
1129 areq->tsgl = NULL;
1130 areq->tsgl_entries = 0;
1131
1132 return areq;
1133}
1134EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
1135
1136/**
1137 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1138 * operation
1139 *
1140 * @sk: socket of connection to user space
1141 * @msg: user space message
1142 * @flags: flags used to invoke recvmsg with
1143 * @areq: instance of the cryptographic request that will hold the RX SGL
1144 * @maxsize: maximum number of bytes to be pulled from user space
1145 * @outlen: number of bytes in the RX SGL
1146 * Return: 0 on success, < 0 upon error
1147 */
1148int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
1149 struct af_alg_async_req *areq, size_t maxsize,
1150 size_t *outlen)
1151{
1152 struct alg_sock *ask = alg_sk(sk);
1153 struct af_alg_ctx *ctx = ask->private;
1154 size_t len = 0;
1155
1156 while (maxsize > len && msg_data_left(msg)) {
1157 struct af_alg_rsgl *rsgl;
1158 size_t seglen;
1159 int err;
1160
1161 /* limit the amount of readable buffers */
1162 if (!af_alg_readable(sk))
1163 break;
1164
1165 seglen = min_t(size_t, (maxsize - len),
1166 msg_data_left(msg));
1167
1168 if (list_empty(&areq->rsgl_list)) {
1169 rsgl = &areq->first_rsgl;
1170 } else {
1171 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
1172 if (unlikely(!rsgl))
1173 return -ENOMEM;
1174 }
1175
1176 rsgl->sgl.npages = 0;
1177 list_add_tail(&rsgl->list, &areq->rsgl_list);
1178
1179 /* make one iovec available as scatterlist */
1180 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
1181 if (err < 0) {
1182 rsgl->sg_num_bytes = 0;
1183 return err;
1184 }
1185
1186 /* chain the new scatterlist with previous one */
1187 if (areq->last_rsgl)
1188 af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
1189
1190 areq->last_rsgl = rsgl;
1191 len += err;
1192 atomic_add(err, &ctx->rcvused);
1193 rsgl->sg_num_bytes = err;
1194 iov_iter_advance(&msg->msg_iter, err);
1195 }
1196
1197 *outlen = len;
1198 return 0;
1199}
1200EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
1201
1202static int __init af_alg_init(void)
1203{
1204 int err = proto_register(&alg_proto, 0);
1205
1206 if (err)
1207 goto out;
1208
1209 err = sock_register(&alg_family);
1210 if (err != 0)
1211 goto out_unregister_proto;
1212
1213out:
1214 return err;
1215
1216out_unregister_proto:
1217 proto_unregister(&alg_proto);
1218 goto out;
1219}
1220
1221static void __exit af_alg_exit(void)
1222{
1223 sock_unregister(PF_ALG);
1224 proto_unregister(&alg_proto);
1225}
1226
1227module_init(af_alg_init);
1228module_exit(af_alg_exit);
1229MODULE_LICENSE("GPL");
1230MODULE_ALIAS_NETPROTO(AF_ALG);