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(error: -ENOENT);
46 struct alg_type_list *node;
47
48 down_read(sem: &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(module: node->type->owner))
54 type = node->type;
55 break;
56 }
57 up_read(sem: &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(sem: &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(size: 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(new: &node->list, head: &alg_types);
83 err = 0;
84
85unlock:
86 up_write(sem: &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(sem: &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(entry: &node->list);
103 kfree(objp: node);
104 err = 0;
105 break;
106 }
107 up_write(sem: &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(module: type->owner);
120}
121
122int af_alg_release(struct socket *sock)
123{
124 if (sock->sk) {
125 sock_put(sk: 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(v: &ask->nokey_refcnt);
136
137 sk = ask->parent;
138 ask = alg_sk(sk);
139
140 if (nokey)
141 atomic_dec(v: &ask->nokey_refcnt);
142
143 if (atomic_dec_and_test(v: &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(name: sa->salg_type);
176 if (PTR_ERR(ptr: type) == -ENOENT) {
177 request_module("algif-%s", sa->salg_type);
178 type = alg_get_type(name: sa->salg_type);
179 }
180
181 if (IS_ERR(ptr: type))
182 return PTR_ERR(ptr: type);
183
184 private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask);
185 if (IS_ERR(ptr: private)) {
186 module_put(module: type->owner);
187 return PTR_ERR(ptr: private);
188 }
189
190 err = -EBUSY;
191 lock_sock(sk);
192 if (atomic_read(v: &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, size: keylen, GFP_KERNEL);
216 if (!key)
217 return -ENOMEM;
218
219 err = -EFAULT;
220 if (copy_from_sockptr(dst: key, src: ukey, size: keylen))
221 goto out;
222
223 err = type->setkey(ask->private, key, keylen);
224
225out:
226 sock_kzfree_s(sk, mem: key, size: 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(ptr: ukp))
240 return ERR_PTR(error: -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(ptr: ekp))
254 return ERR_PTR(error: -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(ptr: tkp))
268 return ERR_PTR(error: -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(id: serial, flags: 0, need_perm: KEY_NEED_SEARCH);
280 if (IS_ERR(ptr: key_ref))
281 return ERR_CAST(ptr: 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(dst: &serial, src: optval, size: optlen))
301 return -EFAULT;
302
303 key = lookup_key(serial);
304 if (IS_ERR(ptr: key))
305 return PTR_ERR(ptr: key);
306
307 down_read(sem: &key->sem);
308
309 ret = ERR_PTR(error: -ENOPROTOOPT);
310 if (!strcmp(key->type->name, "user") ||
311 !strcmp(key->type->name, "logon")) {
312 ret = key_data_ptr_user(key, datalen: &key_datalen);
313 } else if (IS_REACHABLE(CONFIG_ENCRYPTED_KEYS) &&
314 !strcmp(key->type->name, "encrypted")) {
315 ret = key_data_ptr_encrypted(key, datalen: &key_datalen);
316 } else if (IS_REACHABLE(CONFIG_TRUSTED_KEYS) &&
317 !strcmp(key->type->name, "trusted")) {
318 ret = key_data_ptr_trusted(key, datalen: &key_datalen);
319 }
320
321 if (IS_ERR(ptr: ret)) {
322 up_read(sem: &key->sem);
323 key_put(key);
324 return PTR_ERR(ptr: ret);
325 }
326
327 key_data = sock_kmalloc(sk: &ask->sk, size: key_datalen, GFP_KERNEL);
328 if (!key_data) {
329 up_read(sem: &key->sem);
330 key_put(key);
331 return -ENOMEM;
332 }
333
334 memcpy(key_data, ret, key_datalen);
335
336 up_read(sem: &key->sem);
337 key_put(key);
338
339 err = type->setkey(ask->private, key_data, key_datalen);
340
341 sock_kzfree_s(sk: &ask->sk, mem: key_data, size: key_datalen);
342
343 return err;
344}
345
346#else
347
348static inline int alg_setkey_by_key_serial(struct alg_sock *ask,
349 sockptr_t optval,
350 unsigned int optlen)
351{
352 return -ENOPROTOOPT;
353}
354
355#endif
356
357static int alg_setsockopt(struct socket *sock, int level, int optname,
358 sockptr_t optval, unsigned int optlen)
359{
360 struct sock *sk = sock->sk;
361 struct alg_sock *ask = alg_sk(sk);
362 const struct af_alg_type *type;
363 int err = -EBUSY;
364
365 lock_sock(sk);
366 if (atomic_read(v: &ask->refcnt) != atomic_read(v: &ask->nokey_refcnt))
367 goto unlock;
368
369 type = ask->type;
370
371 err = -ENOPROTOOPT;
372 if (level != SOL_ALG || !type)
373 goto unlock;
374
375 switch (optname) {
376 case ALG_SET_KEY:
377 case ALG_SET_KEY_BY_KEY_SERIAL:
378 if (sock->state == SS_CONNECTED)
379 goto unlock;
380 if (!type->setkey)
381 goto unlock;
382
383 if (optname == ALG_SET_KEY_BY_KEY_SERIAL)
384 err = alg_setkey_by_key_serial(ask, optval, optlen);
385 else
386 err = alg_setkey(sk, ukey: optval, keylen: optlen);
387 break;
388 case ALG_SET_AEAD_AUTHSIZE:
389 if (sock->state == SS_CONNECTED)
390 goto unlock;
391 if (!type->setauthsize)
392 goto unlock;
393 err = type->setauthsize(ask->private, optlen);
394 break;
395 case ALG_SET_DRBG_ENTROPY:
396 if (sock->state == SS_CONNECTED)
397 goto unlock;
398 if (!type->setentropy)
399 goto unlock;
400
401 err = type->setentropy(ask->private, optval, optlen);
402 }
403
404unlock:
405 release_sock(sk);
406
407 return err;
408}
409
410int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern)
411{
412 struct alg_sock *ask = alg_sk(sk);
413 const struct af_alg_type *type;
414 struct sock *sk2;
415 unsigned int nokey;
416 int err;
417
418 lock_sock(sk);
419 type = ask->type;
420
421 err = -EINVAL;
422 if (!type)
423 goto unlock;
424
425 sk2 = sk_alloc(net: sock_net(sk), PF_ALG, GFP_KERNEL, prot: &alg_proto, kern);
426 err = -ENOMEM;
427 if (!sk2)
428 goto unlock;
429
430 sock_init_data(sock: newsock, sk: sk2);
431 security_sock_graft(sk: sk2, parent: newsock);
432 security_sk_clone(sk, newsk: sk2);
433
434 /*
435 * newsock->ops assigned here to allow type->accept call to override
436 * them when required.
437 */
438 newsock->ops = type->ops;
439 err = type->accept(ask->private, sk2);
440
441 nokey = err == -ENOKEY;
442 if (nokey && type->accept_nokey)
443 err = type->accept_nokey(ask->private, sk2);
444
445 if (err)
446 goto unlock;
447
448 if (atomic_inc_return_relaxed(v: &ask->refcnt) == 1)
449 sock_hold(sk);
450 if (nokey) {
451 atomic_inc(v: &ask->nokey_refcnt);
452 atomic_set(v: &alg_sk(sk: sk2)->nokey_refcnt, i: 1);
453 }
454 alg_sk(sk: sk2)->parent = sk;
455 alg_sk(sk: sk2)->type = type;
456
457 newsock->state = SS_CONNECTED;
458
459 if (nokey)
460 newsock->ops = type->ops_nokey;
461
462 err = 0;
463
464unlock:
465 release_sock(sk);
466
467 return err;
468}
469EXPORT_SYMBOL_GPL(af_alg_accept);
470
471static int alg_accept(struct socket *sock, struct socket *newsock, int flags,
472 bool kern)
473{
474 return af_alg_accept(sock->sk, newsock, kern);
475}
476
477static const struct proto_ops alg_proto_ops = {
478 .family = PF_ALG,
479 .owner = THIS_MODULE,
480
481 .connect = sock_no_connect,
482 .socketpair = sock_no_socketpair,
483 .getname = sock_no_getname,
484 .ioctl = sock_no_ioctl,
485 .listen = sock_no_listen,
486 .shutdown = sock_no_shutdown,
487 .mmap = sock_no_mmap,
488 .sendmsg = sock_no_sendmsg,
489 .recvmsg = sock_no_recvmsg,
490
491 .bind = alg_bind,
492 .release = af_alg_release,
493 .setsockopt = alg_setsockopt,
494 .accept = alg_accept,
495};
496
497static void alg_sock_destruct(struct sock *sk)
498{
499 struct alg_sock *ask = alg_sk(sk);
500
501 alg_do_release(type: ask->type, private: ask->private);
502}
503
504static int alg_create(struct net *net, struct socket *sock, int protocol,
505 int kern)
506{
507 struct sock *sk;
508 int err;
509
510 if (sock->type != SOCK_SEQPACKET)
511 return -ESOCKTNOSUPPORT;
512 if (protocol != 0)
513 return -EPROTONOSUPPORT;
514
515 err = -ENOMEM;
516 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, prot: &alg_proto, kern);
517 if (!sk)
518 goto out;
519
520 sock->ops = &alg_proto_ops;
521 sock_init_data(sock, sk);
522
523 sk->sk_destruct = alg_sock_destruct;
524
525 return 0;
526out:
527 return err;
528}
529
530static const struct net_proto_family alg_family = {
531 .family = PF_ALG,
532 .create = alg_create,
533 .owner = THIS_MODULE,
534};
535
536static void af_alg_link_sg(struct af_alg_sgl *sgl_prev,
537 struct af_alg_sgl *sgl_new)
538{
539 sg_unmark_end(sg: sgl_prev->sgt.sgl + sgl_prev->sgt.nents - 1);
540 sg_chain(prv: sgl_prev->sgt.sgl, prv_nents: sgl_prev->sgt.nents + 1, sgl: sgl_new->sgt.sgl);
541}
542
543void af_alg_free_sg(struct af_alg_sgl *sgl)
544{
545 int i;
546
547 if (sgl->sgt.sgl) {
548 if (sgl->need_unpin)
549 for (i = 0; i < sgl->sgt.nents; i++)
550 unpin_user_page(page: sg_page(sg: &sgl->sgt.sgl[i]));
551 if (sgl->sgt.sgl != sgl->sgl)
552 kvfree(addr: sgl->sgt.sgl);
553 sgl->sgt.sgl = NULL;
554 }
555}
556EXPORT_SYMBOL_GPL(af_alg_free_sg);
557
558static int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
559{
560 struct cmsghdr *cmsg;
561
562 for_each_cmsghdr(cmsg, msg) {
563 if (!CMSG_OK(msg, cmsg))
564 return -EINVAL;
565 if (cmsg->cmsg_level != SOL_ALG)
566 continue;
567
568 switch (cmsg->cmsg_type) {
569 case ALG_SET_IV:
570 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
571 return -EINVAL;
572 con->iv = (void *)CMSG_DATA(cmsg);
573 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
574 sizeof(*con->iv)))
575 return -EINVAL;
576 break;
577
578 case ALG_SET_OP:
579 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
580 return -EINVAL;
581 con->op = *(u32 *)CMSG_DATA(cmsg);
582 break;
583
584 case ALG_SET_AEAD_ASSOCLEN:
585 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
586 return -EINVAL;
587 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
588 break;
589
590 default:
591 return -EINVAL;
592 }
593 }
594
595 return 0;
596}
597
598/**
599 * af_alg_alloc_tsgl - allocate the TX SGL
600 *
601 * @sk: socket of connection to user space
602 * Return: 0 upon success, < 0 upon error
603 */
604static int af_alg_alloc_tsgl(struct sock *sk)
605{
606 struct alg_sock *ask = alg_sk(sk);
607 struct af_alg_ctx *ctx = ask->private;
608 struct af_alg_tsgl *sgl;
609 struct scatterlist *sg = NULL;
610
611 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
612 if (!list_empty(head: &ctx->tsgl_list))
613 sg = sgl->sg;
614
615 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
616 sgl = sock_kmalloc(sk,
617 struct_size(sgl, sg, (MAX_SGL_ENTS + 1)),
618 GFP_KERNEL);
619 if (!sgl)
620 return -ENOMEM;
621
622 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
623 sgl->cur = 0;
624
625 if (sg)
626 sg_chain(prv: sg, MAX_SGL_ENTS + 1, sgl: sgl->sg);
627
628 list_add_tail(new: &sgl->list, head: &ctx->tsgl_list);
629 }
630
631 return 0;
632}
633
634/**
635 * af_alg_count_tsgl - Count number of TX SG entries
636 *
637 * The counting starts from the beginning of the SGL to @bytes. If
638 * an @offset is provided, the counting of the SG entries starts at the @offset.
639 *
640 * @sk: socket of connection to user space
641 * @bytes: Count the number of SG entries holding given number of bytes.
642 * @offset: Start the counting of SG entries from the given offset.
643 * Return: Number of TX SG entries found given the constraints
644 */
645unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
646{
647 const struct alg_sock *ask = alg_sk(sk);
648 const struct af_alg_ctx *ctx = ask->private;
649 const struct af_alg_tsgl *sgl;
650 unsigned int i;
651 unsigned int sgl_count = 0;
652
653 if (!bytes)
654 return 0;
655
656 list_for_each_entry(sgl, &ctx->tsgl_list, list) {
657 const struct scatterlist *sg = sgl->sg;
658
659 for (i = 0; i < sgl->cur; i++) {
660 size_t bytes_count;
661
662 /* Skip offset */
663 if (offset >= sg[i].length) {
664 offset -= sg[i].length;
665 bytes -= sg[i].length;
666 continue;
667 }
668
669 bytes_count = sg[i].length - offset;
670
671 offset = 0;
672 sgl_count++;
673
674 /* If we have seen requested number of bytes, stop */
675 if (bytes_count >= bytes)
676 return sgl_count;
677
678 bytes -= bytes_count;
679 }
680 }
681
682 return sgl_count;
683}
684EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
685
686/**
687 * af_alg_pull_tsgl - Release the specified buffers from TX SGL
688 *
689 * If @dst is non-null, reassign the pages to @dst. The caller must release
690 * the pages. If @dst_offset is given only reassign the pages to @dst starting
691 * at the @dst_offset (byte). The caller must ensure that @dst is large
692 * enough (e.g. by using af_alg_count_tsgl with the same offset).
693 *
694 * @sk: socket of connection to user space
695 * @used: Number of bytes to pull from TX SGL
696 * @dst: If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
697 * caller must release the buffers in dst.
698 * @dst_offset: Reassign the TX SGL from given offset. All buffers before
699 * reaching the offset is released.
700 */
701void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
702 size_t dst_offset)
703{
704 struct alg_sock *ask = alg_sk(sk);
705 struct af_alg_ctx *ctx = ask->private;
706 struct af_alg_tsgl *sgl;
707 struct scatterlist *sg;
708 unsigned int i, j = 0;
709
710 while (!list_empty(head: &ctx->tsgl_list)) {
711 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
712 list);
713 sg = sgl->sg;
714
715 for (i = 0; i < sgl->cur; i++) {
716 size_t plen = min_t(size_t, used, sg[i].length);
717 struct page *page = sg_page(sg: sg + i);
718
719 if (!page)
720 continue;
721
722 /*
723 * Assumption: caller created af_alg_count_tsgl(len)
724 * SG entries in dst.
725 */
726 if (dst) {
727 if (dst_offset >= plen) {
728 /* discard page before offset */
729 dst_offset -= plen;
730 } else {
731 /* reassign page to dst after offset */
732 get_page(page);
733 sg_set_page(sg: dst + j, page,
734 len: plen - dst_offset,
735 offset: sg[i].offset + dst_offset);
736 dst_offset = 0;
737 j++;
738 }
739 }
740
741 sg[i].length -= plen;
742 sg[i].offset += plen;
743
744 used -= plen;
745 ctx->used -= plen;
746
747 if (sg[i].length)
748 return;
749
750 put_page(page);
751 sg_assign_page(sg: sg + i, NULL);
752 }
753
754 list_del(entry: &sgl->list);
755 sock_kfree_s(sk, mem: sgl, struct_size(sgl, sg, MAX_SGL_ENTS + 1));
756 }
757
758 if (!ctx->used)
759 ctx->merge = 0;
760 ctx->init = ctx->more;
761}
762EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
763
764/**
765 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
766 *
767 * @areq: Request holding the TX and RX SGL
768 */
769static void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
770{
771 struct sock *sk = areq->sk;
772 struct alg_sock *ask = alg_sk(sk);
773 struct af_alg_ctx *ctx = ask->private;
774 struct af_alg_rsgl *rsgl, *tmp;
775 struct scatterlist *tsgl;
776 struct scatterlist *sg;
777 unsigned int i;
778
779 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
780 atomic_sub(i: rsgl->sg_num_bytes, v: &ctx->rcvused);
781 af_alg_free_sg(&rsgl->sgl);
782 list_del(entry: &rsgl->list);
783 if (rsgl != &areq->first_rsgl)
784 sock_kfree_s(sk, mem: rsgl, size: sizeof(*rsgl));
785 }
786
787 tsgl = areq->tsgl;
788 if (tsgl) {
789 for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
790 if (!sg_page(sg))
791 continue;
792 put_page(page: sg_page(sg));
793 }
794
795 sock_kfree_s(sk, mem: tsgl, size: areq->tsgl_entries * sizeof(*tsgl));
796 }
797}
798
799/**
800 * af_alg_wait_for_wmem - wait for availability of writable memory
801 *
802 * @sk: socket of connection to user space
803 * @flags: If MSG_DONTWAIT is set, then only report if function would sleep
804 * Return: 0 when writable memory is available, < 0 upon error
805 */
806static int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
807{
808 DEFINE_WAIT_FUNC(wait, woken_wake_function);
809 int err = -ERESTARTSYS;
810 long timeout;
811
812 if (flags & MSG_DONTWAIT)
813 return -EAGAIN;
814
815 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
816
817 add_wait_queue(wq_head: sk_sleep(sk), wq_entry: &wait);
818 for (;;) {
819 if (signal_pending(current))
820 break;
821 timeout = MAX_SCHEDULE_TIMEOUT;
822 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
823 err = 0;
824 break;
825 }
826 }
827 remove_wait_queue(wq_head: sk_sleep(sk), wq_entry: &wait);
828
829 return err;
830}
831
832/**
833 * af_alg_wmem_wakeup - wakeup caller when writable memory is available
834 *
835 * @sk: socket of connection to user space
836 */
837void af_alg_wmem_wakeup(struct sock *sk)
838{
839 struct socket_wq *wq;
840
841 if (!af_alg_writable(sk))
842 return;
843
844 rcu_read_lock();
845 wq = rcu_dereference(sk->sk_wq);
846 if (skwq_has_sleeper(wq))
847 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN |
848 EPOLLRDNORM |
849 EPOLLRDBAND);
850 sk_wake_async(sk, how: SOCK_WAKE_WAITD, POLL_IN);
851 rcu_read_unlock();
852}
853EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
854
855/**
856 * af_alg_wait_for_data - wait for availability of TX data
857 *
858 * @sk: socket of connection to user space
859 * @flags: If MSG_DONTWAIT is set, then only report if function would sleep
860 * @min: Set to minimum request size if partial requests are allowed.
861 * Return: 0 when writable memory is available, < 0 upon error
862 */
863int af_alg_wait_for_data(struct sock *sk, unsigned flags, unsigned min)
864{
865 DEFINE_WAIT_FUNC(wait, woken_wake_function);
866 struct alg_sock *ask = alg_sk(sk);
867 struct af_alg_ctx *ctx = ask->private;
868 long timeout;
869 int err = -ERESTARTSYS;
870
871 if (flags & MSG_DONTWAIT)
872 return -EAGAIN;
873
874 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
875
876 add_wait_queue(wq_head: sk_sleep(sk), wq_entry: &wait);
877 for (;;) {
878 if (signal_pending(current))
879 break;
880 timeout = MAX_SCHEDULE_TIMEOUT;
881 if (sk_wait_event(sk, &timeout,
882 ctx->init && (!ctx->more ||
883 (min && ctx->used >= min)),
884 &wait)) {
885 err = 0;
886 break;
887 }
888 }
889 remove_wait_queue(wq_head: sk_sleep(sk), wq_entry: &wait);
890
891 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
892
893 return err;
894}
895EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
896
897/**
898 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
899 *
900 * @sk: socket of connection to user space
901 */
902static void af_alg_data_wakeup(struct sock *sk)
903{
904 struct alg_sock *ask = alg_sk(sk);
905 struct af_alg_ctx *ctx = ask->private;
906 struct socket_wq *wq;
907
908 if (!ctx->used)
909 return;
910
911 rcu_read_lock();
912 wq = rcu_dereference(sk->sk_wq);
913 if (skwq_has_sleeper(wq))
914 wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
915 EPOLLRDNORM |
916 EPOLLRDBAND);
917 sk_wake_async(sk, how: SOCK_WAKE_SPACE, POLL_OUT);
918 rcu_read_unlock();
919}
920
921/**
922 * af_alg_sendmsg - implementation of sendmsg system call handler
923 *
924 * The sendmsg system call handler obtains the user data and stores it
925 * in ctx->tsgl_list. This implies allocation of the required numbers of
926 * struct af_alg_tsgl.
927 *
928 * In addition, the ctx is filled with the information sent via CMSG.
929 *
930 * @sock: socket of connection to user space
931 * @msg: message from user space
932 * @size: size of message from user space
933 * @ivsize: the size of the IV for the cipher operation to verify that the
934 * user-space-provided IV has the right size
935 * Return: the number of copied data upon success, < 0 upon error
936 */
937int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
938 unsigned int ivsize)
939{
940 struct sock *sk = sock->sk;
941 struct alg_sock *ask = alg_sk(sk);
942 struct af_alg_ctx *ctx = ask->private;
943 struct af_alg_tsgl *sgl;
944 struct af_alg_control con = {};
945 long copied = 0;
946 bool enc = false;
947 bool init = false;
948 int err = 0;
949
950 if (msg->msg_controllen) {
951 err = af_alg_cmsg_send(msg, con: &con);
952 if (err)
953 return err;
954
955 init = true;
956 switch (con.op) {
957 case ALG_OP_ENCRYPT:
958 enc = true;
959 break;
960 case ALG_OP_DECRYPT:
961 enc = false;
962 break;
963 default:
964 return -EINVAL;
965 }
966
967 if (con.iv && con.iv->ivlen != ivsize)
968 return -EINVAL;
969 }
970
971 lock_sock(sk);
972 if (ctx->init && !ctx->more) {
973 if (ctx->used) {
974 err = -EINVAL;
975 goto unlock;
976 }
977
978 pr_info_once(
979 "%s sent an empty control message without MSG_MORE.\n",
980 current->comm);
981 }
982 ctx->init = true;
983
984 if (init) {
985 ctx->enc = enc;
986 if (con.iv)
987 memcpy(ctx->iv, con.iv->iv, ivsize);
988
989 ctx->aead_assoclen = con.aead_assoclen;
990 }
991
992 while (size) {
993 struct scatterlist *sg;
994 size_t len = size;
995 ssize_t plen;
996
997 /* use the existing memory in an allocated page */
998 if (ctx->merge && !(msg->msg_flags & MSG_SPLICE_PAGES)) {
999 sgl = list_entry(ctx->tsgl_list.prev,
1000 struct af_alg_tsgl, list);
1001 sg = sgl->sg + sgl->cur - 1;
1002 len = min_t(size_t, len,
1003 PAGE_SIZE - sg->offset - sg->length);
1004
1005 err = memcpy_from_msg(page_address(sg_page(sg)) +
1006 sg->offset + sg->length,
1007 msg, len);
1008 if (err)
1009 goto unlock;
1010
1011 sg->length += len;
1012 ctx->merge = (sg->offset + sg->length) &
1013 (PAGE_SIZE - 1);
1014
1015 ctx->used += len;
1016 copied += len;
1017 size -= len;
1018 continue;
1019 }
1020
1021 if (!af_alg_writable(sk)) {
1022 err = af_alg_wait_for_wmem(sk, flags: msg->msg_flags);
1023 if (err)
1024 goto unlock;
1025 }
1026
1027 /* allocate a new page */
1028 len = min_t(unsigned long, len, af_alg_sndbuf(sk));
1029
1030 err = af_alg_alloc_tsgl(sk);
1031 if (err)
1032 goto unlock;
1033
1034 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
1035 list);
1036 sg = sgl->sg;
1037 if (sgl->cur)
1038 sg_unmark_end(sg: sg + sgl->cur - 1);
1039
1040 if (msg->msg_flags & MSG_SPLICE_PAGES) {
1041 struct sg_table sgtable = {
1042 .sgl = sg,
1043 .nents = sgl->cur,
1044 .orig_nents = sgl->cur,
1045 };
1046
1047 plen = extract_iter_to_sg(iter: &msg->msg_iter, len, sgtable: &sgtable,
1048 MAX_SGL_ENTS - sgl->cur, extraction_flags: 0);
1049 if (plen < 0) {
1050 err = plen;
1051 goto unlock;
1052 }
1053
1054 for (; sgl->cur < sgtable.nents; sgl->cur++)
1055 get_page(page: sg_page(sg: &sg[sgl->cur]));
1056 len -= plen;
1057 ctx->used += plen;
1058 copied += plen;
1059 size -= plen;
1060 ctx->merge = 0;
1061 } else {
1062 do {
1063 struct page *pg;
1064 unsigned int i = sgl->cur;
1065
1066 plen = min_t(size_t, len, PAGE_SIZE);
1067
1068 pg = alloc_page(GFP_KERNEL);
1069 if (!pg) {
1070 err = -ENOMEM;
1071 goto unlock;
1072 }
1073
1074 sg_assign_page(sg: sg + i, page: pg);
1075
1076 err = memcpy_from_msg(
1077 page_address(sg_page(sg + i)),
1078 msg, len: plen);
1079 if (err) {
1080 __free_page(sg_page(sg + i));
1081 sg_assign_page(sg: 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 ctx->merge = plen & (PAGE_SIZE - 1);
1094 }
1095
1096 if (!size)
1097 sg_mark_end(sg: sg + sgl->cur - 1);
1098 }
1099
1100 err = 0;
1101
1102 ctx->more = msg->msg_flags & MSG_MORE;
1103
1104unlock:
1105 af_alg_data_wakeup(sk);
1106 release_sock(sk);
1107
1108 return copied ?: err;
1109}
1110EXPORT_SYMBOL_GPL(af_alg_sendmsg);
1111
1112/**
1113 * af_alg_free_resources - release resources required for crypto request
1114 * @areq: Request holding the TX and RX SGL
1115 */
1116void af_alg_free_resources(struct af_alg_async_req *areq)
1117{
1118 struct sock *sk = areq->sk;
1119 struct af_alg_ctx *ctx;
1120
1121 af_alg_free_areq_sgls(areq);
1122 sock_kfree_s(sk, mem: areq, size: areq->areqlen);
1123
1124 ctx = alg_sk(sk)->private;
1125 ctx->inflight = false;
1126}
1127EXPORT_SYMBOL_GPL(af_alg_free_resources);
1128
1129/**
1130 * af_alg_async_cb - AIO callback handler
1131 * @data: async request completion data
1132 * @err: if non-zero, error result to be returned via ki_complete();
1133 * otherwise return the AIO output length via ki_complete().
1134 *
1135 * This handler cleans up the struct af_alg_async_req upon completion of the
1136 * AIO operation.
1137 *
1138 * The number of bytes to be generated with the AIO operation must be set
1139 * in areq->outlen before the AIO callback handler is invoked.
1140 */
1141void af_alg_async_cb(void *data, int err)
1142{
1143 struct af_alg_async_req *areq = data;
1144 struct sock *sk = areq->sk;
1145 struct kiocb *iocb = areq->iocb;
1146 unsigned int resultlen;
1147
1148 /* Buffer size written by crypto operation. */
1149 resultlen = areq->outlen;
1150
1151 af_alg_free_resources(areq);
1152 sock_put(sk);
1153
1154 iocb->ki_complete(iocb, err ? err : (int)resultlen);
1155}
1156EXPORT_SYMBOL_GPL(af_alg_async_cb);
1157
1158/**
1159 * af_alg_poll - poll system call handler
1160 * @file: file pointer
1161 * @sock: socket to poll
1162 * @wait: poll_table
1163 */
1164__poll_t af_alg_poll(struct file *file, struct socket *sock,
1165 poll_table *wait)
1166{
1167 struct sock *sk = sock->sk;
1168 struct alg_sock *ask = alg_sk(sk);
1169 struct af_alg_ctx *ctx = ask->private;
1170 __poll_t mask;
1171
1172 sock_poll_wait(filp: file, sock, p: wait);
1173 mask = 0;
1174
1175 if (!ctx->more || ctx->used)
1176 mask |= EPOLLIN | EPOLLRDNORM;
1177
1178 if (af_alg_writable(sk))
1179 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1180
1181 return mask;
1182}
1183EXPORT_SYMBOL_GPL(af_alg_poll);
1184
1185/**
1186 * af_alg_alloc_areq - allocate struct af_alg_async_req
1187 *
1188 * @sk: socket of connection to user space
1189 * @areqlen: size of struct af_alg_async_req + crypto_*_reqsize
1190 * Return: allocated data structure or ERR_PTR upon error
1191 */
1192struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
1193 unsigned int areqlen)
1194{
1195 struct af_alg_ctx *ctx = alg_sk(sk)->private;
1196 struct af_alg_async_req *areq;
1197
1198 /* Only one AIO request can be in flight. */
1199 if (ctx->inflight)
1200 return ERR_PTR(error: -EBUSY);
1201
1202 areq = sock_kmalloc(sk, size: areqlen, GFP_KERNEL);
1203 if (unlikely(!areq))
1204 return ERR_PTR(error: -ENOMEM);
1205
1206 ctx->inflight = true;
1207
1208 areq->areqlen = areqlen;
1209 areq->sk = sk;
1210 areq->first_rsgl.sgl.sgt.sgl = areq->first_rsgl.sgl.sgl;
1211 areq->last_rsgl = NULL;
1212 INIT_LIST_HEAD(list: &areq->rsgl_list);
1213 areq->tsgl = NULL;
1214 areq->tsgl_entries = 0;
1215
1216 return areq;
1217}
1218EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
1219
1220/**
1221 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1222 * operation
1223 *
1224 * @sk: socket of connection to user space
1225 * @msg: user space message
1226 * @flags: flags used to invoke recvmsg with
1227 * @areq: instance of the cryptographic request that will hold the RX SGL
1228 * @maxsize: maximum number of bytes to be pulled from user space
1229 * @outlen: number of bytes in the RX SGL
1230 * Return: 0 on success, < 0 upon error
1231 */
1232int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
1233 struct af_alg_async_req *areq, size_t maxsize,
1234 size_t *outlen)
1235{
1236 struct alg_sock *ask = alg_sk(sk);
1237 struct af_alg_ctx *ctx = ask->private;
1238 size_t len = 0;
1239
1240 while (maxsize > len && msg_data_left(msg)) {
1241 struct af_alg_rsgl *rsgl;
1242 ssize_t err;
1243 size_t seglen;
1244
1245 /* limit the amount of readable buffers */
1246 if (!af_alg_readable(sk))
1247 break;
1248
1249 seglen = min_t(size_t, (maxsize - len),
1250 msg_data_left(msg));
1251
1252 if (list_empty(head: &areq->rsgl_list)) {
1253 rsgl = &areq->first_rsgl;
1254 } else {
1255 rsgl = sock_kmalloc(sk, size: sizeof(*rsgl), GFP_KERNEL);
1256 if (unlikely(!rsgl))
1257 return -ENOMEM;
1258 }
1259
1260 rsgl->sgl.need_unpin =
1261 iov_iter_extract_will_pin(iter: &msg->msg_iter);
1262 rsgl->sgl.sgt.sgl = rsgl->sgl.sgl;
1263 rsgl->sgl.sgt.nents = 0;
1264 rsgl->sgl.sgt.orig_nents = 0;
1265 list_add_tail(new: &rsgl->list, head: &areq->rsgl_list);
1266
1267 sg_init_table(rsgl->sgl.sgt.sgl, ALG_MAX_PAGES);
1268 err = extract_iter_to_sg(iter: &msg->msg_iter, len: seglen, sgtable: &rsgl->sgl.sgt,
1269 ALG_MAX_PAGES, extraction_flags: 0);
1270 if (err < 0) {
1271 rsgl->sg_num_bytes = 0;
1272 return err;
1273 }
1274
1275 sg_mark_end(sg: rsgl->sgl.sgt.sgl + rsgl->sgl.sgt.nents - 1);
1276
1277 /* chain the new scatterlist with previous one */
1278 if (areq->last_rsgl)
1279 af_alg_link_sg(sgl_prev: &areq->last_rsgl->sgl, sgl_new: &rsgl->sgl);
1280
1281 areq->last_rsgl = rsgl;
1282 len += err;
1283 atomic_add(i: err, v: &ctx->rcvused);
1284 rsgl->sg_num_bytes = err;
1285 }
1286
1287 *outlen = len;
1288 return 0;
1289}
1290EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
1291
1292static int __init af_alg_init(void)
1293{
1294 int err = proto_register(prot: &alg_proto, alloc_slab: 0);
1295
1296 if (err)
1297 goto out;
1298
1299 err = sock_register(fam: &alg_family);
1300 if (err != 0)
1301 goto out_unregister_proto;
1302
1303out:
1304 return err;
1305
1306out_unregister_proto:
1307 proto_unregister(prot: &alg_proto);
1308 goto out;
1309}
1310
1311static void __exit af_alg_exit(void)
1312{
1313 sock_unregister(PF_ALG);
1314 proto_unregister(prot: &alg_proto);
1315}
1316
1317module_init(af_alg_init);
1318module_exit(af_alg_exit);
1319MODULE_LICENSE("GPL");
1320MODULE_ALIAS_NETPROTO(AF_ALG);
1321

source code of linux/crypto/af_alg.c