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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.h>
20#include <linux/sched/signal.h>
21#include <linux/security.h>
22
23struct alg_type_list {
24 const struct af_alg_type *type;
25 struct list_head list;
26};
27
28static atomic_long_t alg_memory_allocated;
29
30static struct proto alg_proto = {
31 .name = "ALG",
32 .owner = THIS_MODULE,
33 .memory_allocated = &alg_memory_allocated,
34 .obj_size = sizeof(struct alg_sock),
35};
36
37static LIST_HEAD(alg_types);
38static DECLARE_RWSEM(alg_types_sem);
39
40static const struct af_alg_type *alg_get_type(const char *name)
41{
42 const struct af_alg_type *type = ERR_PTR(-ENOENT);
43 struct alg_type_list *node;
44
45 down_read(&alg_types_sem);
46 list_for_each_entry(node, &alg_types, list) {
47 if (strcmp(node->type->name, name))
48 continue;
49
50 if (try_module_get(node->type->owner))
51 type = node->type;
52 break;
53 }
54 up_read(&alg_types_sem);
55
56 return type;
57}
58
59int af_alg_register_type(const struct af_alg_type *type)
60{
61 struct alg_type_list *node;
62 int err = -EEXIST;
63
64 down_write(&alg_types_sem);
65 list_for_each_entry(node, &alg_types, list) {
66 if (!strcmp(node->type->name, type->name))
67 goto unlock;
68 }
69
70 node = kmalloc(sizeof(*node), GFP_KERNEL);
71 err = -ENOMEM;
72 if (!node)
73 goto unlock;
74
75 type->ops->owner = THIS_MODULE;
76 if (type->ops_nokey)
77 type->ops_nokey->owner = THIS_MODULE;
78 node->type = type;
79 list_add(&node->list, &alg_types);
80 err = 0;
81
82unlock:
83 up_write(&alg_types_sem);
84
85 return err;
86}
87EXPORT_SYMBOL_GPL(af_alg_register_type);
88
89int af_alg_unregister_type(const struct af_alg_type *type)
90{
91 struct alg_type_list *node;
92 int err = -ENOENT;
93
94 down_write(&alg_types_sem);
95 list_for_each_entry(node, &alg_types, list) {
96 if (strcmp(node->type->name, type->name))
97 continue;
98
99 list_del(&node->list);
100 kfree(node);
101 err = 0;
102 break;
103 }
104 up_write(&alg_types_sem);
105
106 return err;
107}
108EXPORT_SYMBOL_GPL(af_alg_unregister_type);
109
110static void alg_do_release(const struct af_alg_type *type, void *private)
111{
112 if (!type)
113 return;
114
115 type->release(private);
116 module_put(type->owner);
117}
118
119int af_alg_release(struct socket *sock)
120{
121 if (sock->sk) {
122 sock_put(sock->sk);
123 sock->sk = NULL;
124 }
125 return 0;
126}
127EXPORT_SYMBOL_GPL(af_alg_release);
128
129void af_alg_release_parent(struct sock *sk)
130{
131 struct alg_sock *ask = alg_sk(sk);
132 unsigned int nokey = atomic_read(&ask->nokey_refcnt);
133
134 sk = ask->parent;
135 ask = alg_sk(sk);
136
137 if (nokey)
138 atomic_dec(&ask->nokey_refcnt);
139
140 if (atomic_dec_and_test(&ask->refcnt))
141 sock_put(sk);
142}
143EXPORT_SYMBOL_GPL(af_alg_release_parent);
144
145static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
146{
147 const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY;
148 struct sock *sk = sock->sk;
149 struct alg_sock *ask = alg_sk(sk);
150 struct sockaddr_alg *sa = (void *)uaddr;
151 const struct af_alg_type *type;
152 void *private;
153 int err;
154
155 if (sock->state == SS_CONNECTED)
156 return -EINVAL;
157
158 if (addr_len < sizeof(*sa))
159 return -EINVAL;
160
161 /* If caller uses non-allowed flag, return error. */
162 if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed))
163 return -EINVAL;
164
165 sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
166 sa->salg_name[sizeof(sa->salg_name) + addr_len - sizeof(*sa) - 1] = 0;
167
168 type = alg_get_type(sa->salg_type);
169 if (PTR_ERR(type) == -ENOENT) {
170 request_module("algif-%s", sa->salg_type);
171 type = alg_get_type(sa->salg_type);
172 }
173
174 if (IS_ERR(type))
175 return PTR_ERR(type);
176
177 private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask);
178 if (IS_ERR(private)) {
179 module_put(type->owner);
180 return PTR_ERR(private);
181 }
182
183 err = -EBUSY;
184 lock_sock(sk);
185 if (atomic_read(&ask->refcnt))
186 goto unlock;
187
188 swap(ask->type, type);
189 swap(ask->private, private);
190
191 err = 0;
192
193unlock:
194 release_sock(sk);
195
196 alg_do_release(type, private);
197
198 return err;
199}
200
201static int alg_setkey(struct sock *sk, sockptr_t ukey, unsigned int keylen)
202{
203 struct alg_sock *ask = alg_sk(sk);
204 const struct af_alg_type *type = ask->type;
205 u8 *key;
206 int err;
207
208 key = sock_kmalloc(sk, keylen, GFP_KERNEL);
209 if (!key)
210 return -ENOMEM;
211
212 err = -EFAULT;
213 if (copy_from_sockptr(key, ukey, keylen))
214 goto out;
215
216 err = type->setkey(ask->private, key, keylen);
217
218out:
219 sock_kzfree_s(sk, key, keylen);
220
221 return err;
222}
223
224static int alg_setsockopt(struct socket *sock, int level, int optname,
225 sockptr_t optval, unsigned int optlen)
226{
227 struct sock *sk = sock->sk;
228 struct alg_sock *ask = alg_sk(sk);
229 const struct af_alg_type *type;
230 int err = -EBUSY;
231
232 lock_sock(sk);
233 if (atomic_read(&ask->refcnt) != atomic_read(&ask->nokey_refcnt))
234 goto unlock;
235
236 type = ask->type;
237
238 err = -ENOPROTOOPT;
239 if (level != SOL_ALG || !type)
240 goto unlock;
241
242 switch (optname) {
243 case ALG_SET_KEY:
244 if (sock->state == SS_CONNECTED)
245 goto unlock;
246 if (!type->setkey)
247 goto unlock;
248
249 err = alg_setkey(sk, optval, optlen);
250 break;
251 case ALG_SET_AEAD_AUTHSIZE:
252 if (sock->state == SS_CONNECTED)
253 goto unlock;
254 if (!type->setauthsize)
255 goto unlock;
256 err = type->setauthsize(ask->private, optlen);
257 }
258
259unlock:
260 release_sock(sk);
261
262 return err;
263}
264
265int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern)
266{
267 struct alg_sock *ask = alg_sk(sk);
268 const struct af_alg_type *type;
269 struct sock *sk2;
270 unsigned int nokey;
271 int err;
272
273 lock_sock(sk);
274 type = ask->type;
275
276 err = -EINVAL;
277 if (!type)
278 goto unlock;
279
280 sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, kern);
281 err = -ENOMEM;
282 if (!sk2)
283 goto unlock;
284
285 sock_init_data(newsock, sk2);
286 security_sock_graft(sk2, newsock);
287 security_sk_clone(sk, sk2);
288
289 err = type->accept(ask->private, sk2);
290
291 nokey = err == -ENOKEY;
292 if (nokey && type->accept_nokey)
293 err = type->accept_nokey(ask->private, sk2);
294
295 if (err)
296 goto unlock;
297
298 if (atomic_inc_return_relaxed(&ask->refcnt) == 1)
299 sock_hold(sk);
300 if (nokey) {
301 atomic_inc(&ask->nokey_refcnt);
302 atomic_set(&alg_sk(sk2)->nokey_refcnt, 1);
303 }
304 alg_sk(sk2)->parent = sk;
305 alg_sk(sk2)->type = type;
306
307 newsock->ops = type->ops;
308 newsock->state = SS_CONNECTED;
309
310 if (nokey)
311 newsock->ops = type->ops_nokey;
312
313 err = 0;
314
315unlock:
316 release_sock(sk);
317
318 return err;
319}
320EXPORT_SYMBOL_GPL(af_alg_accept);
321
322static int alg_accept(struct socket *sock, struct socket *newsock, int flags,
323 bool kern)
324{
325 return af_alg_accept(sock->sk, newsock, kern);
326}
327
328static const struct proto_ops alg_proto_ops = {
329 .family = PF_ALG,
330 .owner = THIS_MODULE,
331
332 .connect = sock_no_connect,
333 .socketpair = sock_no_socketpair,
334 .getname = sock_no_getname,
335 .ioctl = sock_no_ioctl,
336 .listen = sock_no_listen,
337 .shutdown = sock_no_shutdown,
338 .mmap = sock_no_mmap,
339 .sendpage = sock_no_sendpage,
340 .sendmsg = sock_no_sendmsg,
341 .recvmsg = sock_no_recvmsg,
342
343 .bind = alg_bind,
344 .release = af_alg_release,
345 .setsockopt = alg_setsockopt,
346 .accept = alg_accept,
347};
348
349static void alg_sock_destruct(struct sock *sk)
350{
351 struct alg_sock *ask = alg_sk(sk);
352
353 alg_do_release(ask->type, ask->private);
354}
355
356static int alg_create(struct net *net, struct socket *sock, int protocol,
357 int kern)
358{
359 struct sock *sk;
360 int err;
361
362 if (sock->type != SOCK_SEQPACKET)
363 return -ESOCKTNOSUPPORT;
364 if (protocol != 0)
365 return -EPROTONOSUPPORT;
366
367 err = -ENOMEM;
368 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
369 if (!sk)
370 goto out;
371
372 sock->ops = &alg_proto_ops;
373 sock_init_data(sock, sk);
374
375 sk->sk_destruct = alg_sock_destruct;
376
377 return 0;
378out:
379 return err;
380}
381
382static const struct net_proto_family alg_family = {
383 .family = PF_ALG,
384 .create = alg_create,
385 .owner = THIS_MODULE,
386};
387
388int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
389{
390 size_t off;
391 ssize_t n;
392 int npages, i;
393
394 n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
395 if (n < 0)
396 return n;
397
398 npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT;
399 if (WARN_ON(npages == 0))
400 return -EINVAL;
401 /* Add one extra for linking */
402 sg_init_table(sgl->sg, npages + 1);
403
404 for (i = 0, len = n; i < npages; i++) {
405 int plen = min_t(int, len, PAGE_SIZE - off);
406
407 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
408
409 off = 0;
410 len -= plen;
411 }
412 sg_mark_end(sgl->sg + npages - 1);
413 sgl->npages = npages;
414
415 return n;
416}
417EXPORT_SYMBOL_GPL(af_alg_make_sg);
418
419static void af_alg_link_sg(struct af_alg_sgl *sgl_prev,
420 struct af_alg_sgl *sgl_new)
421{
422 sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
423 sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
424}
425
426void af_alg_free_sg(struct af_alg_sgl *sgl)
427{
428 int i;
429
430 for (i = 0; i < sgl->npages; i++)
431 put_page(sgl->pages[i]);
432}
433EXPORT_SYMBOL_GPL(af_alg_free_sg);
434
435static int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
436{
437 struct cmsghdr *cmsg;
438
439 for_each_cmsghdr(cmsg, msg) {
440 if (!CMSG_OK(msg, cmsg))
441 return -EINVAL;
442 if (cmsg->cmsg_level != SOL_ALG)
443 continue;
444
445 switch (cmsg->cmsg_type) {
446 case ALG_SET_IV:
447 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
448 return -EINVAL;
449 con->iv = (void *)CMSG_DATA(cmsg);
450 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
451 sizeof(*con->iv)))
452 return -EINVAL;
453 break;
454
455 case ALG_SET_OP:
456 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
457 return -EINVAL;
458 con->op = *(u32 *)CMSG_DATA(cmsg);
459 break;
460
461 case ALG_SET_AEAD_ASSOCLEN:
462 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
463 return -EINVAL;
464 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
465 break;
466
467 default:
468 return -EINVAL;
469 }
470 }
471
472 return 0;
473}
474
475/**
476 * af_alg_alloc_tsgl - allocate the TX SGL
477 *
478 * @sk socket of connection to user space
479 * @return: 0 upon success, < 0 upon error
480 */
481static int af_alg_alloc_tsgl(struct sock *sk)
482{
483 struct alg_sock *ask = alg_sk(sk);
484 struct af_alg_ctx *ctx = ask->private;
485 struct af_alg_tsgl *sgl;
486 struct scatterlist *sg = NULL;
487
488 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
489 if (!list_empty(&ctx->tsgl_list))
490 sg = sgl->sg;
491
492 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
493 sgl = sock_kmalloc(sk,
494 struct_size(sgl, sg, (MAX_SGL_ENTS + 1)),
495 GFP_KERNEL);
496 if (!sgl)
497 return -ENOMEM;
498
499 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
500 sgl->cur = 0;
501
502 if (sg)
503 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
504
505 list_add_tail(&sgl->list, &ctx->tsgl_list);
506 }
507
508 return 0;
509}
510
511/**
512 * aead_count_tsgl - Count number of TX SG entries
513 *
514 * The counting starts from the beginning of the SGL to @bytes. If
515 * an offset is provided, the counting of the SG entries starts at the offset.
516 *
517 * @sk socket of connection to user space
518 * @bytes Count the number of SG entries holding given number of bytes.
519 * @offset Start the counting of SG entries from the given offset.
520 * @return Number of TX SG entries found given the constraints
521 */
522unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
523{
524 const struct alg_sock *ask = alg_sk(sk);
525 const struct af_alg_ctx *ctx = ask->private;
526 const struct af_alg_tsgl *sgl;
527 unsigned int i;
528 unsigned int sgl_count = 0;
529
530 if (!bytes)
531 return 0;
532
533 list_for_each_entry(sgl, &ctx->tsgl_list, list) {
534 const struct scatterlist *sg = sgl->sg;
535
536 for (i = 0; i < sgl->cur; i++) {
537 size_t bytes_count;
538
539 /* Skip offset */
540 if (offset >= sg[i].length) {
541 offset -= sg[i].length;
542 bytes -= sg[i].length;
543 continue;
544 }
545
546 bytes_count = sg[i].length - offset;
547
548 offset = 0;
549 sgl_count++;
550
551 /* If we have seen requested number of bytes, stop */
552 if (bytes_count >= bytes)
553 return sgl_count;
554
555 bytes -= bytes_count;
556 }
557 }
558
559 return sgl_count;
560}
561EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
562
563/**
564 * aead_pull_tsgl - Release the specified buffers from TX SGL
565 *
566 * If @dst is non-null, reassign the pages to dst. The caller must release
567 * the pages. If @dst_offset is given only reassign the pages to @dst starting
568 * at the @dst_offset (byte). The caller must ensure that @dst is large
569 * enough (e.g. by using af_alg_count_tsgl with the same offset).
570 *
571 * @sk socket of connection to user space
572 * @used Number of bytes to pull from TX SGL
573 * @dst If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
574 * caller must release the buffers in dst.
575 * @dst_offset Reassign the TX SGL from given offset. All buffers before
576 * reaching the offset is released.
577 */
578void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
579 size_t dst_offset)
580{
581 struct alg_sock *ask = alg_sk(sk);
582 struct af_alg_ctx *ctx = ask->private;
583 struct af_alg_tsgl *sgl;
584 struct scatterlist *sg;
585 unsigned int i, j = 0;
586
587 while (!list_empty(&ctx->tsgl_list)) {
588 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
589 list);
590 sg = sgl->sg;
591
592 for (i = 0; i < sgl->cur; i++) {
593 size_t plen = min_t(size_t, used, sg[i].length);
594 struct page *page = sg_page(sg + i);
595
596 if (!page)
597 continue;
598
599 /*
600 * Assumption: caller created af_alg_count_tsgl(len)
601 * SG entries in dst.
602 */
603 if (dst) {
604 if (dst_offset >= plen) {
605 /* discard page before offset */
606 dst_offset -= plen;
607 } else {
608 /* reassign page to dst after offset */
609 get_page(page);
610 sg_set_page(dst + j, page,
611 plen - dst_offset,
612 sg[i].offset + dst_offset);
613 dst_offset = 0;
614 j++;
615 }
616 }
617
618 sg[i].length -= plen;
619 sg[i].offset += plen;
620
621 used -= plen;
622 ctx->used -= plen;
623
624 if (sg[i].length)
625 return;
626
627 put_page(page);
628 sg_assign_page(sg + i, NULL);
629 }
630
631 list_del(&sgl->list);
632 sock_kfree_s(sk, sgl, struct_size(sgl, sg, MAX_SGL_ENTS + 1));
633 }
634
635 if (!ctx->used)
636 ctx->merge = 0;
637 ctx->init = ctx->more;
638}
639EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
640
641/**
642 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
643 *
644 * @areq Request holding the TX and RX SGL
645 */
646static void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
647{
648 struct sock *sk = areq->sk;
649 struct alg_sock *ask = alg_sk(sk);
650 struct af_alg_ctx *ctx = ask->private;
651 struct af_alg_rsgl *rsgl, *tmp;
652 struct scatterlist *tsgl;
653 struct scatterlist *sg;
654 unsigned int i;
655
656 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
657 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
658 af_alg_free_sg(&rsgl->sgl);
659 list_del(&rsgl->list);
660 if (rsgl != &areq->first_rsgl)
661 sock_kfree_s(sk, rsgl, sizeof(*rsgl));
662 }
663
664 tsgl = areq->tsgl;
665 if (tsgl) {
666 for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
667 if (!sg_page(sg))
668 continue;
669 put_page(sg_page(sg));
670 }
671
672 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
673 }
674}
675
676/**
677 * af_alg_wait_for_wmem - wait for availability of writable memory
678 *
679 * @sk socket of connection to user space
680 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
681 * @return 0 when writable memory is available, < 0 upon error
682 */
683static int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
684{
685 DEFINE_WAIT_FUNC(wait, woken_wake_function);
686 int err = -ERESTARTSYS;
687 long timeout;
688
689 if (flags & MSG_DONTWAIT)
690 return -EAGAIN;
691
692 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
693
694 add_wait_queue(sk_sleep(sk), &wait);
695 for (;;) {
696 if (signal_pending(current))
697 break;
698 timeout = MAX_SCHEDULE_TIMEOUT;
699 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
700 err = 0;
701 break;
702 }
703 }
704 remove_wait_queue(sk_sleep(sk), &wait);
705
706 return err;
707}
708
709/**
710 * af_alg_wmem_wakeup - wakeup caller when writable memory is available
711 *
712 * @sk socket of connection to user space
713 */
714void af_alg_wmem_wakeup(struct sock *sk)
715{
716 struct socket_wq *wq;
717
718 if (!af_alg_writable(sk))
719 return;
720
721 rcu_read_lock();
722 wq = rcu_dereference(sk->sk_wq);
723 if (skwq_has_sleeper(wq))
724 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN |
725 EPOLLRDNORM |
726 EPOLLRDBAND);
727 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
728 rcu_read_unlock();
729}
730EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
731
732/**
733 * af_alg_wait_for_data - wait for availability of TX data
734 *
735 * @sk socket of connection to user space
736 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
737 * @min Set to minimum request size if partial requests are allowed.
738 * @return 0 when writable memory is available, < 0 upon error
739 */
740int af_alg_wait_for_data(struct sock *sk, unsigned flags, unsigned min)
741{
742 DEFINE_WAIT_FUNC(wait, woken_wake_function);
743 struct alg_sock *ask = alg_sk(sk);
744 struct af_alg_ctx *ctx = ask->private;
745 long timeout;
746 int err = -ERESTARTSYS;
747
748 if (flags & MSG_DONTWAIT)
749 return -EAGAIN;
750
751 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
752
753 add_wait_queue(sk_sleep(sk), &wait);
754 for (;;) {
755 if (signal_pending(current))
756 break;
757 timeout = MAX_SCHEDULE_TIMEOUT;
758 if (sk_wait_event(sk, &timeout,
759 ctx->init && (!ctx->more ||
760 (min && ctx->used >= min)),
761 &wait)) {
762 err = 0;
763 break;
764 }
765 }
766 remove_wait_queue(sk_sleep(sk), &wait);
767
768 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
769
770 return err;
771}
772EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
773
774/**
775 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
776 *
777 * @sk socket of connection to user space
778 */
779static void af_alg_data_wakeup(struct sock *sk)
780{
781 struct alg_sock *ask = alg_sk(sk);
782 struct af_alg_ctx *ctx = ask->private;
783 struct socket_wq *wq;
784
785 if (!ctx->used)
786 return;
787
788 rcu_read_lock();
789 wq = rcu_dereference(sk->sk_wq);
790 if (skwq_has_sleeper(wq))
791 wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
792 EPOLLRDNORM |
793 EPOLLRDBAND);
794 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
795 rcu_read_unlock();
796}
797
798/**
799 * af_alg_sendmsg - implementation of sendmsg system call handler
800 *
801 * The sendmsg system call handler obtains the user data and stores it
802 * in ctx->tsgl_list. This implies allocation of the required numbers of
803 * struct af_alg_tsgl.
804 *
805 * In addition, the ctx is filled with the information sent via CMSG.
806 *
807 * @sock socket of connection to user space
808 * @msg message from user space
809 * @size size of message from user space
810 * @ivsize the size of the IV for the cipher operation to verify that the
811 * user-space-provided IV has the right size
812 * @return the number of copied data upon success, < 0 upon error
813 */
814int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
815 unsigned int ivsize)
816{
817 struct sock *sk = sock->sk;
818 struct alg_sock *ask = alg_sk(sk);
819 struct af_alg_ctx *ctx = ask->private;
820 struct af_alg_tsgl *sgl;
821 struct af_alg_control con = {};
822 long copied = 0;
823 bool enc = false;
824 bool init = false;
825 int err = 0;
826
827 if (msg->msg_controllen) {
828 err = af_alg_cmsg_send(msg, &con);
829 if (err)
830 return err;
831
832 init = true;
833 switch (con.op) {
834 case ALG_OP_ENCRYPT:
835 enc = true;
836 break;
837 case ALG_OP_DECRYPT:
838 enc = false;
839 break;
840 default:
841 return -EINVAL;
842 }
843
844 if (con.iv && con.iv->ivlen != ivsize)
845 return -EINVAL;
846 }
847
848 lock_sock(sk);
849 if (ctx->init && !ctx->more) {
850 if (ctx->used) {
851 err = -EINVAL;
852 goto unlock;
853 }
854
855 pr_info_once(
856 "%s sent an empty control message without MSG_MORE.\n",
857 current->comm);
858 }
859 ctx->init = true;
860
861 if (init) {
862 ctx->enc = enc;
863 if (con.iv)
864 memcpy(ctx->iv, con.iv->iv, ivsize);
865
866 ctx->aead_assoclen = con.aead_assoclen;
867 }
868
869 while (size) {
870 struct scatterlist *sg;
871 size_t len = size;
872 size_t plen;
873
874 /* use the existing memory in an allocated page */
875 if (ctx->merge) {
876 sgl = list_entry(ctx->tsgl_list.prev,
877 struct af_alg_tsgl, list);
878 sg = sgl->sg + sgl->cur - 1;
879 len = min_t(size_t, len,
880 PAGE_SIZE - sg->offset - sg->length);
881
882 err = memcpy_from_msg(page_address(sg_page(sg)) +
883 sg->offset + sg->length,
884 msg, len);
885 if (err)
886 goto unlock;
887
888 sg->length += len;
889 ctx->merge = (sg->offset + sg->length) &
890 (PAGE_SIZE - 1);
891
892 ctx->used += len;
893 copied += len;
894 size -= len;
895 continue;
896 }
897
898 if (!af_alg_writable(sk)) {
899 err = af_alg_wait_for_wmem(sk, msg->msg_flags);
900 if (err)
901 goto unlock;
902 }
903
904 /* allocate a new page */
905 len = min_t(unsigned long, len, af_alg_sndbuf(sk));
906
907 err = af_alg_alloc_tsgl(sk);
908 if (err)
909 goto unlock;
910
911 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
912 list);
913 sg = sgl->sg;
914 if (sgl->cur)
915 sg_unmark_end(sg + sgl->cur - 1);
916
917 do {
918 unsigned int i = sgl->cur;
919
920 plen = min_t(size_t, len, PAGE_SIZE);
921
922 sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
923 if (!sg_page(sg + i)) {
924 err = -ENOMEM;
925 goto unlock;
926 }
927
928 err = memcpy_from_msg(page_address(sg_page(sg + i)),
929 msg, plen);
930 if (err) {
931 __free_page(sg_page(sg + i));
932 sg_assign_page(sg + i, NULL);
933 goto unlock;
934 }
935
936 sg[i].length = plen;
937 len -= plen;
938 ctx->used += plen;
939 copied += plen;
940 size -= plen;
941 sgl->cur++;
942 } while (len && sgl->cur < MAX_SGL_ENTS);
943
944 if (!size)
945 sg_mark_end(sg + sgl->cur - 1);
946
947 ctx->merge = plen & (PAGE_SIZE - 1);
948 }
949
950 err = 0;
951
952 ctx->more = msg->msg_flags & MSG_MORE;
953
954unlock:
955 af_alg_data_wakeup(sk);
956 release_sock(sk);
957
958 return copied ?: err;
959}
960EXPORT_SYMBOL_GPL(af_alg_sendmsg);
961
962/**
963 * af_alg_sendpage - sendpage system call handler
964 *
965 * This is a generic implementation of sendpage to fill ctx->tsgl_list.
966 */
967ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
968 int offset, size_t size, int flags)
969{
970 struct sock *sk = sock->sk;
971 struct alg_sock *ask = alg_sk(sk);
972 struct af_alg_ctx *ctx = ask->private;
973 struct af_alg_tsgl *sgl;
974 int err = -EINVAL;
975
976 if (flags & MSG_SENDPAGE_NOTLAST)
977 flags |= MSG_MORE;
978
979 lock_sock(sk);
980 if (!ctx->more && ctx->used)
981 goto unlock;
982
983 if (!size)
984 goto done;
985
986 if (!af_alg_writable(sk)) {
987 err = af_alg_wait_for_wmem(sk, flags);
988 if (err)
989 goto unlock;
990 }
991
992 err = af_alg_alloc_tsgl(sk);
993 if (err)
994 goto unlock;
995
996 ctx->merge = 0;
997 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
998
999 if (sgl->cur)
1000 sg_unmark_end(sgl->sg + sgl->cur - 1);
1001
1002 sg_mark_end(sgl->sg + sgl->cur);
1003
1004 get_page(page);
1005 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
1006 sgl->cur++;
1007 ctx->used += size;
1008
1009done:
1010 ctx->more = flags & MSG_MORE;
1011
1012unlock:
1013 af_alg_data_wakeup(sk);
1014 release_sock(sk);
1015
1016 return err ?: size;
1017}
1018EXPORT_SYMBOL_GPL(af_alg_sendpage);
1019
1020/**
1021 * af_alg_free_resources - release resources required for crypto request
1022 */
1023void af_alg_free_resources(struct af_alg_async_req *areq)
1024{
1025 struct sock *sk = areq->sk;
1026
1027 af_alg_free_areq_sgls(areq);
1028 sock_kfree_s(sk, areq, areq->areqlen);
1029}
1030EXPORT_SYMBOL_GPL(af_alg_free_resources);
1031
1032/**
1033 * af_alg_async_cb - AIO callback handler
1034 *
1035 * This handler cleans up the struct af_alg_async_req upon completion of the
1036 * AIO operation.
1037 *
1038 * The number of bytes to be generated with the AIO operation must be set
1039 * in areq->outlen before the AIO callback handler is invoked.
1040 */
1041void af_alg_async_cb(struct crypto_async_request *_req, int err)
1042{
1043 struct af_alg_async_req *areq = _req->data;
1044 struct sock *sk = areq->sk;
1045 struct kiocb *iocb = areq->iocb;
1046 unsigned int resultlen;
1047
1048 /* Buffer size written by crypto operation. */
1049 resultlen = areq->outlen;
1050
1051 af_alg_free_resources(areq);
1052 sock_put(sk);
1053
1054 iocb->ki_complete(iocb, err ? err : (int)resultlen, 0);
1055}
1056EXPORT_SYMBOL_GPL(af_alg_async_cb);
1057
1058/**
1059 * af_alg_poll - poll system call handler
1060 */
1061__poll_t af_alg_poll(struct file *file, struct socket *sock,
1062 poll_table *wait)
1063{
1064 struct sock *sk = sock->sk;
1065 struct alg_sock *ask = alg_sk(sk);
1066 struct af_alg_ctx *ctx = ask->private;
1067 __poll_t mask;
1068
1069 sock_poll_wait(file, sock, wait);
1070 mask = 0;
1071
1072 if (!ctx->more || ctx->used)
1073 mask |= EPOLLIN | EPOLLRDNORM;
1074
1075 if (af_alg_writable(sk))
1076 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1077
1078 return mask;
1079}
1080EXPORT_SYMBOL_GPL(af_alg_poll);
1081
1082/**
1083 * af_alg_alloc_areq - allocate struct af_alg_async_req
1084 *
1085 * @sk socket of connection to user space
1086 * @areqlen size of struct af_alg_async_req + crypto_*_reqsize
1087 * @return allocated data structure or ERR_PTR upon error
1088 */
1089struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
1090 unsigned int areqlen)
1091{
1092 struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
1093
1094 if (unlikely(!areq))
1095 return ERR_PTR(-ENOMEM);
1096
1097 areq->areqlen = areqlen;
1098 areq->sk = sk;
1099 areq->last_rsgl = NULL;
1100 INIT_LIST_HEAD(&areq->rsgl_list);
1101 areq->tsgl = NULL;
1102 areq->tsgl_entries = 0;
1103
1104 return areq;
1105}
1106EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
1107
1108/**
1109 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1110 * operation
1111 *
1112 * @sk socket of connection to user space
1113 * @msg user space message
1114 * @flags flags used to invoke recvmsg with
1115 * @areq instance of the cryptographic request that will hold the RX SGL
1116 * @maxsize maximum number of bytes to be pulled from user space
1117 * @outlen number of bytes in the RX SGL
1118 * @return 0 on success, < 0 upon error
1119 */
1120int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
1121 struct af_alg_async_req *areq, size_t maxsize,
1122 size_t *outlen)
1123{
1124 struct alg_sock *ask = alg_sk(sk);
1125 struct af_alg_ctx *ctx = ask->private;
1126 size_t len = 0;
1127
1128 while (maxsize > len && msg_data_left(msg)) {
1129 struct af_alg_rsgl *rsgl;
1130 size_t seglen;
1131 int err;
1132
1133 /* limit the amount of readable buffers */
1134 if (!af_alg_readable(sk))
1135 break;
1136
1137 seglen = min_t(size_t, (maxsize - len),
1138 msg_data_left(msg));
1139
1140 if (list_empty(&areq->rsgl_list)) {
1141 rsgl = &areq->first_rsgl;
1142 } else {
1143 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
1144 if (unlikely(!rsgl))
1145 return -ENOMEM;
1146 }
1147
1148 rsgl->sgl.npages = 0;
1149 list_add_tail(&rsgl->list, &areq->rsgl_list);
1150
1151 /* make one iovec available as scatterlist */
1152 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
1153 if (err < 0) {
1154 rsgl->sg_num_bytes = 0;
1155 return err;
1156 }
1157
1158 /* chain the new scatterlist with previous one */
1159 if (areq->last_rsgl)
1160 af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
1161
1162 areq->last_rsgl = rsgl;
1163 len += err;
1164 atomic_add(err, &ctx->rcvused);
1165 rsgl->sg_num_bytes = err;
1166 iov_iter_advance(&msg->msg_iter, err);
1167 }
1168
1169 *outlen = len;
1170 return 0;
1171}
1172EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
1173
1174static int __init af_alg_init(void)
1175{
1176 int err = proto_register(&alg_proto, 0);
1177
1178 if (err)
1179 goto out;
1180
1181 err = sock_register(&alg_family);
1182 if (err != 0)
1183 goto out_unregister_proto;
1184
1185out:
1186 return err;
1187
1188out_unregister_proto:
1189 proto_unregister(&alg_proto);
1190 goto out;
1191}
1192
1193static void __exit af_alg_exit(void)
1194{
1195 sock_unregister(PF_ALG);
1196 proto_unregister(&alg_proto);
1197}
1198
1199module_init(af_alg_init);
1200module_exit(af_alg_exit);
1201MODULE_LICENSE("GPL");
1202MODULE_ALIAS_NETPROTO(AF_ALG);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * af_alg: User-space algorithm interface
4 *
5 * This file provides the user-space API for algorithms.
6 *
7 * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
8 */
9
10#include <linux/atomic.h>
11#include <crypto/if_alg.h>
12#include <linux/crypto.h>
13#include <linux/init.h>
14#include <linux/kernel.h>
15#include <linux/list.h>
16#include <linux/module.h>
17#include <linux/net.h>
18#include <linux/rwsem.h>
19#include <linux/sched.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);