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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/key.h>
16#include <linux/key-type.h>
17#include <linux/list.h>
18#include <linux/module.h>
19#include <linux/net.h>
20#include <linux/rwsem.h>
21#include <linux/sched.h>
22#include <linux/sched/signal.h>
23#include <linux/security.h>
24#include <linux/string.h>
25#include <keys/user-type.h>
26#include <keys/trusted-type.h>
27#include <keys/encrypted-type.h>
28
29struct alg_type_list {
30 const struct af_alg_type *type;
31 struct list_head list;
32};
33
34static struct proto alg_proto = {
35 .name = "ALG",
36 .owner = THIS_MODULE,
37 .obj_size = sizeof(struct alg_sock),
38};
39
40static LIST_HEAD(alg_types);
41static DECLARE_RWSEM(alg_types_sem);
42
43static const struct af_alg_type *alg_get_type(const char *name)
44{
45 const struct af_alg_type *type = ERR_PTR(-ENOENT);
46 struct alg_type_list *node;
47
48 down_read(&alg_types_sem);
49 list_for_each_entry(node, &alg_types, list) {
50 if (strcmp(node->type->name, name))
51 continue;
52
53 if (try_module_get(node->type->owner))
54 type = node->type;
55 break;
56 }
57 up_read(&alg_types_sem);
58
59 return type;
60}
61
62int af_alg_register_type(const struct af_alg_type *type)
63{
64 struct alg_type_list *node;
65 int err = -EEXIST;
66
67 down_write(&alg_types_sem);
68 list_for_each_entry(node, &alg_types, list) {
69 if (!strcmp(node->type->name, type->name))
70 goto unlock;
71 }
72
73 node = kmalloc(sizeof(*node), GFP_KERNEL);
74 err = -ENOMEM;
75 if (!node)
76 goto unlock;
77
78 type->ops->owner = THIS_MODULE;
79 if (type->ops_nokey)
80 type->ops_nokey->owner = THIS_MODULE;
81 node->type = type;
82 list_add(&node->list, &alg_types);
83 err = 0;
84
85unlock:
86 up_write(&alg_types_sem);
87
88 return err;
89}
90EXPORT_SYMBOL_GPL(af_alg_register_type);
91
92int af_alg_unregister_type(const struct af_alg_type *type)
93{
94 struct alg_type_list *node;
95 int err = -ENOENT;
96
97 down_write(&alg_types_sem);
98 list_for_each_entry(node, &alg_types, list) {
99 if (strcmp(node->type->name, type->name))
100 continue;
101
102 list_del(&node->list);
103 kfree(node);
104 err = 0;
105 break;
106 }
107 up_write(&alg_types_sem);
108
109 return err;
110}
111EXPORT_SYMBOL_GPL(af_alg_unregister_type);
112
113static void alg_do_release(const struct af_alg_type *type, void *private)
114{
115 if (!type)
116 return;
117
118 type->release(private);
119 module_put(type->owner);
120}
121
122int af_alg_release(struct socket *sock)
123{
124 if (sock->sk) {
125 sock_put(sock->sk);
126 sock->sk = NULL;
127 }
128 return 0;
129}
130EXPORT_SYMBOL_GPL(af_alg_release);
131
132void af_alg_release_parent(struct sock *sk)
133{
134 struct alg_sock *ask = alg_sk(sk);
135 unsigned int nokey = atomic_read(&ask->nokey_refcnt);
136
137 sk = ask->parent;
138 ask = alg_sk(sk);
139
140 if (nokey)
141 atomic_dec(&ask->nokey_refcnt);
142
143 if (atomic_dec_and_test(&ask->refcnt))
144 sock_put(sk);
145}
146EXPORT_SYMBOL_GPL(af_alg_release_parent);
147
148static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
149{
150 const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY;
151 struct sock *sk = sock->sk;
152 struct alg_sock *ask = alg_sk(sk);
153 struct sockaddr_alg_new *sa = (void *)uaddr;
154 const struct af_alg_type *type;
155 void *private;
156 int err;
157
158 if (sock->state == SS_CONNECTED)
159 return -EINVAL;
160
161 BUILD_BUG_ON(offsetof(struct sockaddr_alg_new, salg_name) !=
162 offsetof(struct sockaddr_alg, salg_name));
163 BUILD_BUG_ON(offsetof(struct sockaddr_alg, salg_name) != sizeof(*sa));
164
165 if (addr_len < sizeof(*sa) + 1)
166 return -EINVAL;
167
168 /* If caller uses non-allowed flag, return error. */
169 if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed))
170 return -EINVAL;
171
172 sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
173 sa->salg_name[addr_len - sizeof(*sa) - 1] = 0;
174
175 type = alg_get_type(sa->salg_type);
176 if (PTR_ERR(type) == -ENOENT) {
177 request_module("algif-%s", sa->salg_type);
178 type = alg_get_type(sa->salg_type);
179 }
180
181 if (IS_ERR(type))
182 return PTR_ERR(type);
183
184 private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask);
185 if (IS_ERR(private)) {
186 module_put(type->owner);
187 return PTR_ERR(private);
188 }
189
190 err = -EBUSY;
191 lock_sock(sk);
192 if (atomic_read(&ask->refcnt))
193 goto unlock;
194
195 swap(ask->type, type);
196 swap(ask->private, private);
197
198 err = 0;
199
200unlock:
201 release_sock(sk);
202
203 alg_do_release(type, private);
204
205 return err;
206}
207
208static int alg_setkey(struct sock *sk, sockptr_t ukey, 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_sockptr(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
231#ifdef CONFIG_KEYS
232
233static const u8 *key_data_ptr_user(const struct key *key,
234 unsigned int *datalen)
235{
236 const struct user_key_payload *ukp;
237
238 ukp = user_key_payload_locked(key);
239 if (IS_ERR_OR_NULL(ukp))
240 return ERR_PTR(-EKEYREVOKED);
241
242 *datalen = key->datalen;
243
244 return ukp->data;
245}
246
247static const u8 *key_data_ptr_encrypted(const struct key *key,
248 unsigned int *datalen)
249{
250 const struct encrypted_key_payload *ekp;
251
252 ekp = dereference_key_locked(key);
253 if (IS_ERR_OR_NULL(ekp))
254 return ERR_PTR(-EKEYREVOKED);
255
256 *datalen = ekp->decrypted_datalen;
257
258 return ekp->decrypted_data;
259}
260
261static const u8 *key_data_ptr_trusted(const struct key *key,
262 unsigned int *datalen)
263{
264 const struct trusted_key_payload *tkp;
265
266 tkp = dereference_key_locked(key);
267 if (IS_ERR_OR_NULL(tkp))
268 return ERR_PTR(-EKEYREVOKED);
269
270 *datalen = tkp->key_len;
271
272 return tkp->key;
273}
274
275static struct key *lookup_key(key_serial_t serial)
276{
277 key_ref_t key_ref;
278
279 key_ref = lookup_user_key(serial, 0, KEY_NEED_SEARCH);
280 if (IS_ERR(key_ref))
281 return ERR_CAST(key_ref);
282
283 return key_ref_to_ptr(key_ref);
284}
285
286static int alg_setkey_by_key_serial(struct alg_sock *ask, sockptr_t optval,
287 unsigned int optlen)
288{
289 const struct af_alg_type *type = ask->type;
290 u8 *key_data = NULL;
291 unsigned int key_datalen;
292 key_serial_t serial;
293 struct key *key;
294 const u8 *ret;
295 int err;
296
297 if (optlen != sizeof(serial))
298 return -EINVAL;
299
300 if (copy_from_sockptr(&serial, optval, optlen))
301 return -EFAULT;
302
303 key = lookup_key(serial);
304 if (IS_ERR(key))
305 return PTR_ERR(key);
306
307 down_read(&key->sem);
308
309 ret = ERR_PTR(-ENOPROTOOPT);
310 if (!strcmp(key->type->name, "user") ||
311 !strcmp(key->type->name, "logon")) {
312 ret = key_data_ptr_user(key, &key_datalen);
313 } else if (IS_REACHABLE(CONFIG_ENCRYPTED_KEYS) &&
314 !strcmp(key->type->name, "encrypted")) {
315 ret = key_data_ptr_encrypted(key, &key_datalen);
316 } else if (IS_REACHABLE(CONFIG_TRUSTED_KEYS) &&
317 !strcmp(key->type->name, "trusted")) {
318 ret = key_data_ptr_trusted(key, &key_datalen);
319 }
320
321 if (IS_ERR(ret)) {
322 up_read(&key->sem);
323 return PTR_ERR(ret);
324 }
325
326 key_data = sock_kmalloc(&ask->sk, key_datalen, GFP_KERNEL);
327 if (!key_data) {
328 up_read(&key->sem);
329 return -ENOMEM;
330 }
331
332 memcpy(key_data, ret, key_datalen);
333
334 up_read(&key->sem);
335
336 err = type->setkey(ask->private, key_data, key_datalen);
337
338 sock_kzfree_s(&ask->sk, key_data, key_datalen);
339
340 return err;
341}
342
343#else
344
345static inline int alg_setkey_by_key_serial(struct alg_sock *ask,
346 sockptr_t optval,
347 unsigned int optlen)
348{
349 return -ENOPROTOOPT;
350}
351
352#endif
353
354static int alg_setsockopt(struct socket *sock, int level, int optname,
355 sockptr_t optval, unsigned int optlen)
356{
357 struct sock *sk = sock->sk;
358 struct alg_sock *ask = alg_sk(sk);
359 const struct af_alg_type *type;
360 int err = -EBUSY;
361
362 lock_sock(sk);
363 if (atomic_read(&ask->refcnt) != atomic_read(&ask->nokey_refcnt))
364 goto unlock;
365
366 type = ask->type;
367
368 err = -ENOPROTOOPT;
369 if (level != SOL_ALG || !type)
370 goto unlock;
371
372 switch (optname) {
373 case ALG_SET_KEY:
374 case ALG_SET_KEY_BY_KEY_SERIAL:
375 if (sock->state == SS_CONNECTED)
376 goto unlock;
377 if (!type->setkey)
378 goto unlock;
379
380 if (optname == ALG_SET_KEY_BY_KEY_SERIAL)
381 err = alg_setkey_by_key_serial(ask, optval, optlen);
382 else
383 err = alg_setkey(sk, optval, optlen);
384 break;
385 case ALG_SET_AEAD_AUTHSIZE:
386 if (sock->state == SS_CONNECTED)
387 goto unlock;
388 if (!type->setauthsize)
389 goto unlock;
390 err = type->setauthsize(ask->private, optlen);
391 break;
392 case ALG_SET_DRBG_ENTROPY:
393 if (sock->state == SS_CONNECTED)
394 goto unlock;
395 if (!type->setentropy)
396 goto unlock;
397
398 err = type->setentropy(ask->private, optval, optlen);
399 }
400
401unlock:
402 release_sock(sk);
403
404 return err;
405}
406
407int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern)
408{
409 struct alg_sock *ask = alg_sk(sk);
410 const struct af_alg_type *type;
411 struct sock *sk2;
412 unsigned int nokey;
413 int err;
414
415 lock_sock(sk);
416 type = ask->type;
417
418 err = -EINVAL;
419 if (!type)
420 goto unlock;
421
422 sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, kern);
423 err = -ENOMEM;
424 if (!sk2)
425 goto unlock;
426
427 sock_init_data(newsock, sk2);
428 security_sock_graft(sk2, newsock);
429 security_sk_clone(sk, sk2);
430
431 /*
432 * newsock->ops assigned here to allow type->accept call to override
433 * them when required.
434 */
435 newsock->ops = type->ops;
436 err = type->accept(ask->private, sk2);
437
438 nokey = err == -ENOKEY;
439 if (nokey && type->accept_nokey)
440 err = type->accept_nokey(ask->private, sk2);
441
442 if (err)
443 goto unlock;
444
445 if (atomic_inc_return_relaxed(&ask->refcnt) == 1)
446 sock_hold(sk);
447 if (nokey) {
448 atomic_inc(&ask->nokey_refcnt);
449 atomic_set(&alg_sk(sk2)->nokey_refcnt, 1);
450 }
451 alg_sk(sk2)->parent = sk;
452 alg_sk(sk2)->type = type;
453
454 newsock->state = SS_CONNECTED;
455
456 if (nokey)
457 newsock->ops = type->ops_nokey;
458
459 err = 0;
460
461unlock:
462 release_sock(sk);
463
464 return err;
465}
466EXPORT_SYMBOL_GPL(af_alg_accept);
467
468static int alg_accept(struct socket *sock, struct socket *newsock, int flags,
469 bool kern)
470{
471 return af_alg_accept(sock->sk, newsock, kern);
472}
473
474static const struct proto_ops alg_proto_ops = {
475 .family = PF_ALG,
476 .owner = THIS_MODULE,
477
478 .connect = sock_no_connect,
479 .socketpair = sock_no_socketpair,
480 .getname = sock_no_getname,
481 .ioctl = sock_no_ioctl,
482 .listen = sock_no_listen,
483 .shutdown = sock_no_shutdown,
484 .mmap = sock_no_mmap,
485 .sendpage = sock_no_sendpage,
486 .sendmsg = sock_no_sendmsg,
487 .recvmsg = sock_no_recvmsg,
488
489 .bind = alg_bind,
490 .release = af_alg_release,
491 .setsockopt = alg_setsockopt,
492 .accept = alg_accept,
493};
494
495static void alg_sock_destruct(struct sock *sk)
496{
497 struct alg_sock *ask = alg_sk(sk);
498
499 alg_do_release(ask->type, ask->private);
500}
501
502static int alg_create(struct net *net, struct socket *sock, int protocol,
503 int kern)
504{
505 struct sock *sk;
506 int err;
507
508 if (sock->type != SOCK_SEQPACKET)
509 return -ESOCKTNOSUPPORT;
510 if (protocol != 0)
511 return -EPROTONOSUPPORT;
512
513 err = -ENOMEM;
514 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
515 if (!sk)
516 goto out;
517
518 sock->ops = &alg_proto_ops;
519 sock_init_data(sock, sk);
520
521 sk->sk_destruct = alg_sock_destruct;
522
523 return 0;
524out:
525 return err;
526}
527
528static const struct net_proto_family alg_family = {
529 .family = PF_ALG,
530 .create = alg_create,
531 .owner = THIS_MODULE,
532};
533
534int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
535{
536 size_t off;
537 ssize_t n;
538 int npages, i;
539
540 n = iov_iter_get_pages2(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
541 if (n < 0)
542 return n;
543
544 npages = DIV_ROUND_UP(off + n, PAGE_SIZE);
545 if (WARN_ON(npages == 0))
546 return -EINVAL;
547 /* Add one extra for linking */
548 sg_init_table(sgl->sg, npages + 1);
549
550 for (i = 0, len = n; i < npages; i++) {
551 int plen = min_t(int, len, PAGE_SIZE - off);
552
553 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
554
555 off = 0;
556 len -= plen;
557 }
558 sg_mark_end(sgl->sg + npages - 1);
559 sgl->npages = npages;
560
561 return n;
562}
563EXPORT_SYMBOL_GPL(af_alg_make_sg);
564
565static void af_alg_link_sg(struct af_alg_sgl *sgl_prev,
566 struct af_alg_sgl *sgl_new)
567{
568 sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
569 sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
570}
571
572void af_alg_free_sg(struct af_alg_sgl *sgl)
573{
574 int i;
575
576 for (i = 0; i < sgl->npages; i++)
577 put_page(sgl->pages[i]);
578}
579EXPORT_SYMBOL_GPL(af_alg_free_sg);
580
581static int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
582{
583 struct cmsghdr *cmsg;
584
585 for_each_cmsghdr(cmsg, msg) {
586 if (!CMSG_OK(msg, cmsg))
587 return -EINVAL;
588 if (cmsg->cmsg_level != SOL_ALG)
589 continue;
590
591 switch (cmsg->cmsg_type) {
592 case ALG_SET_IV:
593 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
594 return -EINVAL;
595 con->iv = (void *)CMSG_DATA(cmsg);
596 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
597 sizeof(*con->iv)))
598 return -EINVAL;
599 break;
600
601 case ALG_SET_OP:
602 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
603 return -EINVAL;
604 con->op = *(u32 *)CMSG_DATA(cmsg);
605 break;
606
607 case ALG_SET_AEAD_ASSOCLEN:
608 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
609 return -EINVAL;
610 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
611 break;
612
613 default:
614 return -EINVAL;
615 }
616 }
617
618 return 0;
619}
620
621/**
622 * af_alg_alloc_tsgl - allocate the TX SGL
623 *
624 * @sk: socket of connection to user space
625 * Return: 0 upon success, < 0 upon error
626 */
627static int af_alg_alloc_tsgl(struct sock *sk)
628{
629 struct alg_sock *ask = alg_sk(sk);
630 struct af_alg_ctx *ctx = ask->private;
631 struct af_alg_tsgl *sgl;
632 struct scatterlist *sg = NULL;
633
634 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
635 if (!list_empty(&ctx->tsgl_list))
636 sg = sgl->sg;
637
638 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
639 sgl = sock_kmalloc(sk,
640 struct_size(sgl, sg, (MAX_SGL_ENTS + 1)),
641 GFP_KERNEL);
642 if (!sgl)
643 return -ENOMEM;
644
645 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
646 sgl->cur = 0;
647
648 if (sg)
649 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
650
651 list_add_tail(&sgl->list, &ctx->tsgl_list);
652 }
653
654 return 0;
655}
656
657/**
658 * af_alg_count_tsgl - Count number of TX SG entries
659 *
660 * The counting starts from the beginning of the SGL to @bytes. If
661 * an @offset is provided, the counting of the SG entries starts at the @offset.
662 *
663 * @sk: socket of connection to user space
664 * @bytes: Count the number of SG entries holding given number of bytes.
665 * @offset: Start the counting of SG entries from the given offset.
666 * Return: Number of TX SG entries found given the constraints
667 */
668unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
669{
670 const struct alg_sock *ask = alg_sk(sk);
671 const struct af_alg_ctx *ctx = ask->private;
672 const struct af_alg_tsgl *sgl;
673 unsigned int i;
674 unsigned int sgl_count = 0;
675
676 if (!bytes)
677 return 0;
678
679 list_for_each_entry(sgl, &ctx->tsgl_list, list) {
680 const struct scatterlist *sg = sgl->sg;
681
682 for (i = 0; i < sgl->cur; i++) {
683 size_t bytes_count;
684
685 /* Skip offset */
686 if (offset >= sg[i].length) {
687 offset -= sg[i].length;
688 bytes -= sg[i].length;
689 continue;
690 }
691
692 bytes_count = sg[i].length - offset;
693
694 offset = 0;
695 sgl_count++;
696
697 /* If we have seen requested number of bytes, stop */
698 if (bytes_count >= bytes)
699 return sgl_count;
700
701 bytes -= bytes_count;
702 }
703 }
704
705 return sgl_count;
706}
707EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
708
709/**
710 * af_alg_pull_tsgl - Release the specified buffers from TX SGL
711 *
712 * If @dst is non-null, reassign the pages to @dst. The caller must release
713 * the pages. If @dst_offset is given only reassign the pages to @dst starting
714 * at the @dst_offset (byte). The caller must ensure that @dst is large
715 * enough (e.g. by using af_alg_count_tsgl with the same offset).
716 *
717 * @sk: socket of connection to user space
718 * @used: Number of bytes to pull from TX SGL
719 * @dst: If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
720 * caller must release the buffers in dst.
721 * @dst_offset: Reassign the TX SGL from given offset. All buffers before
722 * reaching the offset is released.
723 */
724void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
725 size_t dst_offset)
726{
727 struct alg_sock *ask = alg_sk(sk);
728 struct af_alg_ctx *ctx = ask->private;
729 struct af_alg_tsgl *sgl;
730 struct scatterlist *sg;
731 unsigned int i, j = 0;
732
733 while (!list_empty(&ctx->tsgl_list)) {
734 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
735 list);
736 sg = sgl->sg;
737
738 for (i = 0; i < sgl->cur; i++) {
739 size_t plen = min_t(size_t, used, sg[i].length);
740 struct page *page = sg_page(sg + i);
741
742 if (!page)
743 continue;
744
745 /*
746 * Assumption: caller created af_alg_count_tsgl(len)
747 * SG entries in dst.
748 */
749 if (dst) {
750 if (dst_offset >= plen) {
751 /* discard page before offset */
752 dst_offset -= plen;
753 } else {
754 /* reassign page to dst after offset */
755 get_page(page);
756 sg_set_page(dst + j, page,
757 plen - dst_offset,
758 sg[i].offset + dst_offset);
759 dst_offset = 0;
760 j++;
761 }
762 }
763
764 sg[i].length -= plen;
765 sg[i].offset += plen;
766
767 used -= plen;
768 ctx->used -= plen;
769
770 if (sg[i].length)
771 return;
772
773 put_page(page);
774 sg_assign_page(sg + i, NULL);
775 }
776
777 list_del(&sgl->list);
778 sock_kfree_s(sk, sgl, struct_size(sgl, sg, MAX_SGL_ENTS + 1));
779 }
780
781 if (!ctx->used)
782 ctx->merge = 0;
783 ctx->init = ctx->more;
784}
785EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
786
787/**
788 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
789 *
790 * @areq: Request holding the TX and RX SGL
791 */
792static void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
793{
794 struct sock *sk = areq->sk;
795 struct alg_sock *ask = alg_sk(sk);
796 struct af_alg_ctx *ctx = ask->private;
797 struct af_alg_rsgl *rsgl, *tmp;
798 struct scatterlist *tsgl;
799 struct scatterlist *sg;
800 unsigned int i;
801
802 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
803 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
804 af_alg_free_sg(&rsgl->sgl);
805 list_del(&rsgl->list);
806 if (rsgl != &areq->first_rsgl)
807 sock_kfree_s(sk, rsgl, sizeof(*rsgl));
808 }
809
810 tsgl = areq->tsgl;
811 if (tsgl) {
812 for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
813 if (!sg_page(sg))
814 continue;
815 put_page(sg_page(sg));
816 }
817
818 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
819 }
820}
821
822/**
823 * af_alg_wait_for_wmem - wait for availability of writable memory
824 *
825 * @sk: socket of connection to user space
826 * @flags: If MSG_DONTWAIT is set, then only report if function would sleep
827 * Return: 0 when writable memory is available, < 0 upon error
828 */
829static int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
830{
831 DEFINE_WAIT_FUNC(wait, woken_wake_function);
832 int err = -ERESTARTSYS;
833 long timeout;
834
835 if (flags & MSG_DONTWAIT)
836 return -EAGAIN;
837
838 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
839
840 add_wait_queue(sk_sleep(sk), &wait);
841 for (;;) {
842 if (signal_pending(current))
843 break;
844 timeout = MAX_SCHEDULE_TIMEOUT;
845 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
846 err = 0;
847 break;
848 }
849 }
850 remove_wait_queue(sk_sleep(sk), &wait);
851
852 return err;
853}
854
855/**
856 * af_alg_wmem_wakeup - wakeup caller when writable memory is available
857 *
858 * @sk: socket of connection to user space
859 */
860void af_alg_wmem_wakeup(struct sock *sk)
861{
862 struct socket_wq *wq;
863
864 if (!af_alg_writable(sk))
865 return;
866
867 rcu_read_lock();
868 wq = rcu_dereference(sk->sk_wq);
869 if (skwq_has_sleeper(wq))
870 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN |
871 EPOLLRDNORM |
872 EPOLLRDBAND);
873 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
874 rcu_read_unlock();
875}
876EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
877
878/**
879 * af_alg_wait_for_data - wait for availability of TX data
880 *
881 * @sk: socket of connection to user space
882 * @flags: If MSG_DONTWAIT is set, then only report if function would sleep
883 * @min: Set to minimum request size if partial requests are allowed.
884 * Return: 0 when writable memory is available, < 0 upon error
885 */
886int af_alg_wait_for_data(struct sock *sk, unsigned flags, unsigned min)
887{
888 DEFINE_WAIT_FUNC(wait, woken_wake_function);
889 struct alg_sock *ask = alg_sk(sk);
890 struct af_alg_ctx *ctx = ask->private;
891 long timeout;
892 int err = -ERESTARTSYS;
893
894 if (flags & MSG_DONTWAIT)
895 return -EAGAIN;
896
897 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
898
899 add_wait_queue(sk_sleep(sk), &wait);
900 for (;;) {
901 if (signal_pending(current))
902 break;
903 timeout = MAX_SCHEDULE_TIMEOUT;
904 if (sk_wait_event(sk, &timeout,
905 ctx->init && (!ctx->more ||
906 (min && ctx->used >= min)),
907 &wait)) {
908 err = 0;
909 break;
910 }
911 }
912 remove_wait_queue(sk_sleep(sk), &wait);
913
914 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
915
916 return err;
917}
918EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
919
920/**
921 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
922 *
923 * @sk: socket of connection to user space
924 */
925static void af_alg_data_wakeup(struct sock *sk)
926{
927 struct alg_sock *ask = alg_sk(sk);
928 struct af_alg_ctx *ctx = ask->private;
929 struct socket_wq *wq;
930
931 if (!ctx->used)
932 return;
933
934 rcu_read_lock();
935 wq = rcu_dereference(sk->sk_wq);
936 if (skwq_has_sleeper(wq))
937 wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
938 EPOLLRDNORM |
939 EPOLLRDBAND);
940 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
941 rcu_read_unlock();
942}
943
944/**
945 * af_alg_sendmsg - implementation of sendmsg system call handler
946 *
947 * The sendmsg system call handler obtains the user data and stores it
948 * in ctx->tsgl_list. This implies allocation of the required numbers of
949 * struct af_alg_tsgl.
950 *
951 * In addition, the ctx is filled with the information sent via CMSG.
952 *
953 * @sock: socket of connection to user space
954 * @msg: message from user space
955 * @size: size of message from user space
956 * @ivsize: the size of the IV for the cipher operation to verify that the
957 * user-space-provided IV has the right size
958 * Return: the number of copied data upon success, < 0 upon error
959 */
960int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
961 unsigned int ivsize)
962{
963 struct sock *sk = sock->sk;
964 struct alg_sock *ask = alg_sk(sk);
965 struct af_alg_ctx *ctx = ask->private;
966 struct af_alg_tsgl *sgl;
967 struct af_alg_control con = {};
968 long copied = 0;
969 bool enc = false;
970 bool init = false;
971 int err = 0;
972
973 if (msg->msg_controllen) {
974 err = af_alg_cmsg_send(msg, &con);
975 if (err)
976 return err;
977
978 init = true;
979 switch (con.op) {
980 case ALG_OP_ENCRYPT:
981 enc = true;
982 break;
983 case ALG_OP_DECRYPT:
984 enc = false;
985 break;
986 default:
987 return -EINVAL;
988 }
989
990 if (con.iv && con.iv->ivlen != ivsize)
991 return -EINVAL;
992 }
993
994 lock_sock(sk);
995 if (ctx->init && !ctx->more) {
996 if (ctx->used) {
997 err = -EINVAL;
998 goto unlock;
999 }
1000
1001 pr_info_once(
1002 "%s sent an empty control message without MSG_MORE.\n",
1003 current->comm);
1004 }
1005 ctx->init = true;
1006
1007 if (init) {
1008 ctx->enc = enc;
1009 if (con.iv)
1010 memcpy(ctx->iv, con.iv->iv, ivsize);
1011
1012 ctx->aead_assoclen = con.aead_assoclen;
1013 }
1014
1015 while (size) {
1016 struct scatterlist *sg;
1017 size_t len = size;
1018 size_t plen;
1019
1020 /* use the existing memory in an allocated page */
1021 if (ctx->merge) {
1022 sgl = list_entry(ctx->tsgl_list.prev,
1023 struct af_alg_tsgl, list);
1024 sg = sgl->sg + sgl->cur - 1;
1025 len = min_t(size_t, len,
1026 PAGE_SIZE - sg->offset - sg->length);
1027
1028 err = memcpy_from_msg(page_address(sg_page(sg)) +
1029 sg->offset + sg->length,
1030 msg, len);
1031 if (err)
1032 goto unlock;
1033
1034 sg->length += len;
1035 ctx->merge = (sg->offset + sg->length) &
1036 (PAGE_SIZE - 1);
1037
1038 ctx->used += len;
1039 copied += len;
1040 size -= len;
1041 continue;
1042 }
1043
1044 if (!af_alg_writable(sk)) {
1045 err = af_alg_wait_for_wmem(sk, msg->msg_flags);
1046 if (err)
1047 goto unlock;
1048 }
1049
1050 /* allocate a new page */
1051 len = min_t(unsigned long, len, af_alg_sndbuf(sk));
1052
1053 err = af_alg_alloc_tsgl(sk);
1054 if (err)
1055 goto unlock;
1056
1057 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
1058 list);
1059 sg = sgl->sg;
1060 if (sgl->cur)
1061 sg_unmark_end(sg + sgl->cur - 1);
1062
1063 do {
1064 struct page *pg;
1065 unsigned int i = sgl->cur;
1066
1067 plen = min_t(size_t, len, PAGE_SIZE);
1068
1069 pg = alloc_page(GFP_KERNEL);
1070 if (!pg) {
1071 err = -ENOMEM;
1072 goto unlock;
1073 }
1074
1075 sg_assign_page(sg + i, pg);
1076
1077 err = memcpy_from_msg(page_address(sg_page(sg + i)),
1078 msg, plen);
1079 if (err) {
1080 __free_page(sg_page(sg + i));
1081 sg_assign_page(sg + i, NULL);
1082 goto unlock;
1083 }
1084
1085 sg[i].length = plen;
1086 len -= plen;
1087 ctx->used += plen;
1088 copied += plen;
1089 size -= plen;
1090 sgl->cur++;
1091 } while (len && sgl->cur < MAX_SGL_ENTS);
1092
1093 if (!size)
1094 sg_mark_end(sg + sgl->cur - 1);
1095
1096 ctx->merge = plen & (PAGE_SIZE - 1);
1097 }
1098
1099 err = 0;
1100
1101 ctx->more = msg->msg_flags & MSG_MORE;
1102
1103unlock:
1104 af_alg_data_wakeup(sk);
1105 release_sock(sk);
1106
1107 return copied ?: err;
1108}
1109EXPORT_SYMBOL_GPL(af_alg_sendmsg);
1110
1111/**
1112 * af_alg_sendpage - sendpage system call handler
1113 * @sock: socket of connection to user space to write to
1114 * @page: data to send
1115 * @offset: offset into page to begin sending
1116 * @size: length of data
1117 * @flags: message send/receive flags
1118 *
1119 * This is a generic implementation of sendpage to fill ctx->tsgl_list.
1120 */
1121ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
1122 int offset, size_t size, int flags)
1123{
1124 struct sock *sk = sock->sk;
1125 struct alg_sock *ask = alg_sk(sk);
1126 struct af_alg_ctx *ctx = ask->private;
1127 struct af_alg_tsgl *sgl;
1128 int err = -EINVAL;
1129
1130 if (flags & MSG_SENDPAGE_NOTLAST)
1131 flags |= MSG_MORE;
1132
1133 lock_sock(sk);
1134 if (!ctx->more && ctx->used)
1135 goto unlock;
1136
1137 if (!size)
1138 goto done;
1139
1140 if (!af_alg_writable(sk)) {
1141 err = af_alg_wait_for_wmem(sk, flags);
1142 if (err)
1143 goto unlock;
1144 }
1145
1146 err = af_alg_alloc_tsgl(sk);
1147 if (err)
1148 goto unlock;
1149
1150 ctx->merge = 0;
1151 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
1152
1153 if (sgl->cur)
1154 sg_unmark_end(sgl->sg + sgl->cur - 1);
1155
1156 sg_mark_end(sgl->sg + sgl->cur);
1157
1158 get_page(page);
1159 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
1160 sgl->cur++;
1161 ctx->used += size;
1162
1163done:
1164 ctx->more = flags & MSG_MORE;
1165
1166unlock:
1167 af_alg_data_wakeup(sk);
1168 release_sock(sk);
1169
1170 return err ?: size;
1171}
1172EXPORT_SYMBOL_GPL(af_alg_sendpage);
1173
1174/**
1175 * af_alg_free_resources - release resources required for crypto request
1176 * @areq: Request holding the TX and RX SGL
1177 */
1178void af_alg_free_resources(struct af_alg_async_req *areq)
1179{
1180 struct sock *sk = areq->sk;
1181
1182 af_alg_free_areq_sgls(areq);
1183 sock_kfree_s(sk, areq, areq->areqlen);
1184}
1185EXPORT_SYMBOL_GPL(af_alg_free_resources);
1186
1187/**
1188 * af_alg_async_cb - AIO callback handler
1189 * @_req: async request info
1190 * @err: if non-zero, error result to be returned via ki_complete();
1191 * otherwise return the AIO output length via ki_complete().
1192 *
1193 * This handler cleans up the struct af_alg_async_req upon completion of the
1194 * AIO operation.
1195 *
1196 * The number of bytes to be generated with the AIO operation must be set
1197 * in areq->outlen before the AIO callback handler is invoked.
1198 */
1199void af_alg_async_cb(struct crypto_async_request *_req, int err)
1200{
1201 struct af_alg_async_req *areq = _req->data;
1202 struct sock *sk = areq->sk;
1203 struct kiocb *iocb = areq->iocb;
1204 unsigned int resultlen;
1205
1206 /* Buffer size written by crypto operation. */
1207 resultlen = areq->outlen;
1208
1209 af_alg_free_resources(areq);
1210 sock_put(sk);
1211
1212 iocb->ki_complete(iocb, err ? err : (int)resultlen);
1213}
1214EXPORT_SYMBOL_GPL(af_alg_async_cb);
1215
1216/**
1217 * af_alg_poll - poll system call handler
1218 * @file: file pointer
1219 * @sock: socket to poll
1220 * @wait: poll_table
1221 */
1222__poll_t af_alg_poll(struct file *file, struct socket *sock,
1223 poll_table *wait)
1224{
1225 struct sock *sk = sock->sk;
1226 struct alg_sock *ask = alg_sk(sk);
1227 struct af_alg_ctx *ctx = ask->private;
1228 __poll_t mask;
1229
1230 sock_poll_wait(file, sock, wait);
1231 mask = 0;
1232
1233 if (!ctx->more || ctx->used)
1234 mask |= EPOLLIN | EPOLLRDNORM;
1235
1236 if (af_alg_writable(sk))
1237 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1238
1239 return mask;
1240}
1241EXPORT_SYMBOL_GPL(af_alg_poll);
1242
1243/**
1244 * af_alg_alloc_areq - allocate struct af_alg_async_req
1245 *
1246 * @sk: socket of connection to user space
1247 * @areqlen: size of struct af_alg_async_req + crypto_*_reqsize
1248 * Return: allocated data structure or ERR_PTR upon error
1249 */
1250struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
1251 unsigned int areqlen)
1252{
1253 struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
1254
1255 if (unlikely(!areq))
1256 return ERR_PTR(-ENOMEM);
1257
1258 areq->areqlen = areqlen;
1259 areq->sk = sk;
1260 areq->last_rsgl = NULL;
1261 INIT_LIST_HEAD(&areq->rsgl_list);
1262 areq->tsgl = NULL;
1263 areq->tsgl_entries = 0;
1264
1265 return areq;
1266}
1267EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
1268
1269/**
1270 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1271 * operation
1272 *
1273 * @sk: socket of connection to user space
1274 * @msg: user space message
1275 * @flags: flags used to invoke recvmsg with
1276 * @areq: instance of the cryptographic request that will hold the RX SGL
1277 * @maxsize: maximum number of bytes to be pulled from user space
1278 * @outlen: number of bytes in the RX SGL
1279 * Return: 0 on success, < 0 upon error
1280 */
1281int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
1282 struct af_alg_async_req *areq, size_t maxsize,
1283 size_t *outlen)
1284{
1285 struct alg_sock *ask = alg_sk(sk);
1286 struct af_alg_ctx *ctx = ask->private;
1287 size_t len = 0;
1288
1289 while (maxsize > len && msg_data_left(msg)) {
1290 struct af_alg_rsgl *rsgl;
1291 size_t seglen;
1292 int err;
1293
1294 /* limit the amount of readable buffers */
1295 if (!af_alg_readable(sk))
1296 break;
1297
1298 seglen = min_t(size_t, (maxsize - len),
1299 msg_data_left(msg));
1300
1301 if (list_empty(&areq->rsgl_list)) {
1302 rsgl = &areq->first_rsgl;
1303 } else {
1304 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
1305 if (unlikely(!rsgl))
1306 return -ENOMEM;
1307 }
1308
1309 rsgl->sgl.npages = 0;
1310 list_add_tail(&rsgl->list, &areq->rsgl_list);
1311
1312 /* make one iovec available as scatterlist */
1313 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
1314 if (err < 0) {
1315 rsgl->sg_num_bytes = 0;
1316 return err;
1317 }
1318
1319 /* chain the new scatterlist with previous one */
1320 if (areq->last_rsgl)
1321 af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
1322
1323 areq->last_rsgl = rsgl;
1324 len += err;
1325 atomic_add(err, &ctx->rcvused);
1326 rsgl->sg_num_bytes = err;
1327 }
1328
1329 *outlen = len;
1330 return 0;
1331}
1332EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
1333
1334static int __init af_alg_init(void)
1335{
1336 int err = proto_register(&alg_proto, 0);
1337
1338 if (err)
1339 goto out;
1340
1341 err = sock_register(&alg_family);
1342 if (err != 0)
1343 goto out_unregister_proto;
1344
1345out:
1346 return err;
1347
1348out_unregister_proto:
1349 proto_unregister(&alg_proto);
1350 goto out;
1351}
1352
1353static void __exit af_alg_exit(void)
1354{
1355 sock_unregister(PF_ALG);
1356 proto_unregister(&alg_proto);
1357}
1358
1359module_init(af_alg_init);
1360module_exit(af_alg_exit);
1361MODULE_LICENSE("GPL");
1362MODULE_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);