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
23 struct alg_type_list {
24 const struct af_alg_type *type;
25 struct list_head list;
26 };
27
28 static atomic_long_t alg_memory_allocated;
29
30 static 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
37 static LIST_HEAD(alg_types);
38 static DECLARE_RWSEM(alg_types_sem);
39
alg_get_type(const char * name)40 static 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
af_alg_register_type(const struct af_alg_type * type)59 int 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
82 unlock:
83 up_write(&alg_types_sem);
84
85 return err;
86 }
87 EXPORT_SYMBOL_GPL(af_alg_register_type);
88
af_alg_unregister_type(const struct af_alg_type * type)89 int 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 }
108 EXPORT_SYMBOL_GPL(af_alg_unregister_type);
109
alg_do_release(const struct af_alg_type * type,void * private)110 static 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
af_alg_release(struct socket * sock)119 int 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 }
127 EXPORT_SYMBOL_GPL(af_alg_release);
128
af_alg_release_parent(struct sock * sk)129 void 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 }
143 EXPORT_SYMBOL_GPL(af_alg_release_parent);
144
alg_bind(struct socket * sock,struct sockaddr * uaddr,int addr_len)145 static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
146 {
147 const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY;
148 struct sock *sk = sock->sk;
149 struct alg_sock *ask = alg_sk(sk);
150 struct sockaddr_alg *sa = (void *)uaddr;
151 const struct af_alg_type *type;
152 void *private;
153 int err;
154
155 if (sock->state == SS_CONNECTED)
156 return -EINVAL;
157
158 if (addr_len < sizeof(*sa))
159 return -EINVAL;
160
161 /* If caller uses non-allowed flag, return error. */
162 if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed))
163 return -EINVAL;
164
165 sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
166 sa->salg_name[sizeof(sa->salg_name) + addr_len - sizeof(*sa) - 1] = 0;
167
168 type = alg_get_type(sa->salg_type);
169 if (PTR_ERR(type) == -ENOENT) {
170 request_module("algif-%s", sa->salg_type);
171 type = alg_get_type(sa->salg_type);
172 }
173
174 if (IS_ERR(type))
175 return PTR_ERR(type);
176
177 private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask);
178 if (IS_ERR(private)) {
179 module_put(type->owner);
180 return PTR_ERR(private);
181 }
182
183 err = -EBUSY;
184 lock_sock(sk);
185 if (atomic_read(&ask->refcnt))
186 goto unlock;
187
188 swap(ask->type, type);
189 swap(ask->private, private);
190
191 err = 0;
192
193 unlock:
194 release_sock(sk);
195
196 alg_do_release(type, private);
197
198 return err;
199 }
200
alg_setkey(struct sock * sk,sockptr_t ukey,unsigned int keylen)201 static int alg_setkey(struct sock *sk, sockptr_t ukey, unsigned int keylen)
202 {
203 struct alg_sock *ask = alg_sk(sk);
204 const struct af_alg_type *type = ask->type;
205 u8 *key;
206 int err;
207
208 key = sock_kmalloc(sk, keylen, GFP_KERNEL);
209 if (!key)
210 return -ENOMEM;
211
212 err = -EFAULT;
213 if (copy_from_sockptr(key, ukey, keylen))
214 goto out;
215
216 err = type->setkey(ask->private, key, keylen);
217
218 out:
219 sock_kzfree_s(sk, key, keylen);
220
221 return err;
222 }
223
alg_setsockopt(struct socket * sock,int level,int optname,sockptr_t optval,unsigned int optlen)224 static int alg_setsockopt(struct socket *sock, int level, int optname,
225 sockptr_t optval, unsigned int optlen)
226 {
227 struct sock *sk = sock->sk;
228 struct alg_sock *ask = alg_sk(sk);
229 const struct af_alg_type *type;
230 int err = -EBUSY;
231
232 lock_sock(sk);
233 if (atomic_read(&ask->refcnt) != atomic_read(&ask->nokey_refcnt))
234 goto unlock;
235
236 type = ask->type;
237
238 err = -ENOPROTOOPT;
239 if (level != SOL_ALG || !type)
240 goto unlock;
241
242 switch (optname) {
243 case ALG_SET_KEY:
244 if (sock->state == SS_CONNECTED)
245 goto unlock;
246 if (!type->setkey)
247 goto unlock;
248
249 err = alg_setkey(sk, optval, optlen);
250 break;
251 case ALG_SET_AEAD_AUTHSIZE:
252 if (sock->state == SS_CONNECTED)
253 goto unlock;
254 if (!type->setauthsize)
255 goto unlock;
256 err = type->setauthsize(ask->private, optlen);
257 break;
258 case ALG_SET_DRBG_ENTROPY:
259 if (sock->state == SS_CONNECTED)
260 goto unlock;
261 if (!type->setentropy)
262 goto unlock;
263
264 err = type->setentropy(ask->private, optval, optlen);
265 }
266
267 unlock:
268 release_sock(sk);
269
270 return err;
271 }
272
af_alg_accept(struct sock * sk,struct socket * newsock,bool kern)273 int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern)
274 {
275 struct alg_sock *ask = alg_sk(sk);
276 const struct af_alg_type *type;
277 struct sock *sk2;
278 unsigned int nokey;
279 int err;
280
281 lock_sock(sk);
282 type = ask->type;
283
284 err = -EINVAL;
285 if (!type)
286 goto unlock;
287
288 sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, kern);
289 err = -ENOMEM;
290 if (!sk2)
291 goto unlock;
292
293 sock_init_data(newsock, sk2);
294 security_sock_graft(sk2, newsock);
295 security_sk_clone(sk, sk2);
296
297 /*
298 * newsock->ops assigned here to allow type->accept call to override
299 * them when required.
300 */
301 newsock->ops = type->ops;
302 err = type->accept(ask->private, sk2);
303
304 nokey = err == -ENOKEY;
305 if (nokey && type->accept_nokey)
306 err = type->accept_nokey(ask->private, sk2);
307
308 if (err)
309 goto unlock;
310
311 if (atomic_inc_return_relaxed(&ask->refcnt) == 1)
312 sock_hold(sk);
313 if (nokey) {
314 atomic_inc(&ask->nokey_refcnt);
315 atomic_set(&alg_sk(sk2)->nokey_refcnt, 1);
316 }
317 alg_sk(sk2)->parent = sk;
318 alg_sk(sk2)->type = type;
319
320 newsock->state = SS_CONNECTED;
321
322 if (nokey)
323 newsock->ops = type->ops_nokey;
324
325 err = 0;
326
327 unlock:
328 release_sock(sk);
329
330 return err;
331 }
332 EXPORT_SYMBOL_GPL(af_alg_accept);
333
alg_accept(struct socket * sock,struct socket * newsock,int flags,bool kern)334 static int alg_accept(struct socket *sock, struct socket *newsock, int flags,
335 bool kern)
336 {
337 return af_alg_accept(sock->sk, newsock, kern);
338 }
339
340 static const struct proto_ops alg_proto_ops = {
341 .family = PF_ALG,
342 .owner = THIS_MODULE,
343
344 .connect = sock_no_connect,
345 .socketpair = sock_no_socketpair,
346 .getname = sock_no_getname,
347 .ioctl = sock_no_ioctl,
348 .listen = sock_no_listen,
349 .shutdown = sock_no_shutdown,
350 .mmap = sock_no_mmap,
351 .sendpage = sock_no_sendpage,
352 .sendmsg = sock_no_sendmsg,
353 .recvmsg = sock_no_recvmsg,
354
355 .bind = alg_bind,
356 .release = af_alg_release,
357 .setsockopt = alg_setsockopt,
358 .accept = alg_accept,
359 };
360
alg_sock_destruct(struct sock * sk)361 static void alg_sock_destruct(struct sock *sk)
362 {
363 struct alg_sock *ask = alg_sk(sk);
364
365 alg_do_release(ask->type, ask->private);
366 }
367
alg_create(struct net * net,struct socket * sock,int protocol,int kern)368 static int alg_create(struct net *net, struct socket *sock, int protocol,
369 int kern)
370 {
371 struct sock *sk;
372 int err;
373
374 if (sock->type != SOCK_SEQPACKET)
375 return -ESOCKTNOSUPPORT;
376 if (protocol != 0)
377 return -EPROTONOSUPPORT;
378
379 err = -ENOMEM;
380 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
381 if (!sk)
382 goto out;
383
384 sock->ops = &alg_proto_ops;
385 sock_init_data(sock, sk);
386
387 sk->sk_destruct = alg_sock_destruct;
388
389 return 0;
390 out:
391 return err;
392 }
393
394 static const struct net_proto_family alg_family = {
395 .family = PF_ALG,
396 .create = alg_create,
397 .owner = THIS_MODULE,
398 };
399
af_alg_make_sg(struct af_alg_sgl * sgl,struct iov_iter * iter,int len)400 int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
401 {
402 size_t off;
403 ssize_t n;
404 int npages, i;
405
406 n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
407 if (n < 0)
408 return n;
409
410 npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT;
411 if (WARN_ON(npages == 0))
412 return -EINVAL;
413 /* Add one extra for linking */
414 sg_init_table(sgl->sg, npages + 1);
415
416 for (i = 0, len = n; i < npages; i++) {
417 int plen = min_t(int, len, PAGE_SIZE - off);
418
419 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
420
421 off = 0;
422 len -= plen;
423 }
424 sg_mark_end(sgl->sg + npages - 1);
425 sgl->npages = npages;
426
427 return n;
428 }
429 EXPORT_SYMBOL_GPL(af_alg_make_sg);
430
af_alg_link_sg(struct af_alg_sgl * sgl_prev,struct af_alg_sgl * sgl_new)431 static void af_alg_link_sg(struct af_alg_sgl *sgl_prev,
432 struct af_alg_sgl *sgl_new)
433 {
434 sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
435 sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
436 }
437
af_alg_free_sg(struct af_alg_sgl * sgl)438 void af_alg_free_sg(struct af_alg_sgl *sgl)
439 {
440 int i;
441
442 for (i = 0; i < sgl->npages; i++)
443 put_page(sgl->pages[i]);
444 }
445 EXPORT_SYMBOL_GPL(af_alg_free_sg);
446
af_alg_cmsg_send(struct msghdr * msg,struct af_alg_control * con)447 static int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
448 {
449 struct cmsghdr *cmsg;
450
451 for_each_cmsghdr(cmsg, msg) {
452 if (!CMSG_OK(msg, cmsg))
453 return -EINVAL;
454 if (cmsg->cmsg_level != SOL_ALG)
455 continue;
456
457 switch (cmsg->cmsg_type) {
458 case ALG_SET_IV:
459 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
460 return -EINVAL;
461 con->iv = (void *)CMSG_DATA(cmsg);
462 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
463 sizeof(*con->iv)))
464 return -EINVAL;
465 break;
466
467 case ALG_SET_OP:
468 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
469 return -EINVAL;
470 con->op = *(u32 *)CMSG_DATA(cmsg);
471 break;
472
473 case ALG_SET_AEAD_ASSOCLEN:
474 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
475 return -EINVAL;
476 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
477 break;
478
479 default:
480 return -EINVAL;
481 }
482 }
483
484 return 0;
485 }
486
487 /**
488 * af_alg_alloc_tsgl - allocate the TX SGL
489 *
490 * @sk socket of connection to user space
491 * @return: 0 upon success, < 0 upon error
492 */
af_alg_alloc_tsgl(struct sock * sk)493 static int af_alg_alloc_tsgl(struct sock *sk)
494 {
495 struct alg_sock *ask = alg_sk(sk);
496 struct af_alg_ctx *ctx = ask->private;
497 struct af_alg_tsgl *sgl;
498 struct scatterlist *sg = NULL;
499
500 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
501 if (!list_empty(&ctx->tsgl_list))
502 sg = sgl->sg;
503
504 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
505 sgl = sock_kmalloc(sk,
506 struct_size(sgl, sg, (MAX_SGL_ENTS + 1)),
507 GFP_KERNEL);
508 if (!sgl)
509 return -ENOMEM;
510
511 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
512 sgl->cur = 0;
513
514 if (sg)
515 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
516
517 list_add_tail(&sgl->list, &ctx->tsgl_list);
518 }
519
520 return 0;
521 }
522
523 /**
524 * aead_count_tsgl - Count number of TX SG entries
525 *
526 * The counting starts from the beginning of the SGL to @bytes. If
527 * an offset is provided, the counting of the SG entries starts at the offset.
528 *
529 * @sk socket of connection to user space
530 * @bytes Count the number of SG entries holding given number of bytes.
531 * @offset Start the counting of SG entries from the given offset.
532 * @return Number of TX SG entries found given the constraints
533 */
af_alg_count_tsgl(struct sock * sk,size_t bytes,size_t offset)534 unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
535 {
536 const struct alg_sock *ask = alg_sk(sk);
537 const struct af_alg_ctx *ctx = ask->private;
538 const struct af_alg_tsgl *sgl;
539 unsigned int i;
540 unsigned int sgl_count = 0;
541
542 if (!bytes)
543 return 0;
544
545 list_for_each_entry(sgl, &ctx->tsgl_list, list) {
546 const struct scatterlist *sg = sgl->sg;
547
548 for (i = 0; i < sgl->cur; i++) {
549 size_t bytes_count;
550
551 /* Skip offset */
552 if (offset >= sg[i].length) {
553 offset -= sg[i].length;
554 bytes -= sg[i].length;
555 continue;
556 }
557
558 bytes_count = sg[i].length - offset;
559
560 offset = 0;
561 sgl_count++;
562
563 /* If we have seen requested number of bytes, stop */
564 if (bytes_count >= bytes)
565 return sgl_count;
566
567 bytes -= bytes_count;
568 }
569 }
570
571 return sgl_count;
572 }
573 EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
574
575 /**
576 * aead_pull_tsgl - Release the specified buffers from TX SGL
577 *
578 * If @dst is non-null, reassign the pages to dst. The caller must release
579 * the pages. If @dst_offset is given only reassign the pages to @dst starting
580 * at the @dst_offset (byte). The caller must ensure that @dst is large
581 * enough (e.g. by using af_alg_count_tsgl with the same offset).
582 *
583 * @sk socket of connection to user space
584 * @used Number of bytes to pull from TX SGL
585 * @dst If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
586 * caller must release the buffers in dst.
587 * @dst_offset Reassign the TX SGL from given offset. All buffers before
588 * reaching the offset is released.
589 */
af_alg_pull_tsgl(struct sock * sk,size_t used,struct scatterlist * dst,size_t dst_offset)590 void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
591 size_t dst_offset)
592 {
593 struct alg_sock *ask = alg_sk(sk);
594 struct af_alg_ctx *ctx = ask->private;
595 struct af_alg_tsgl *sgl;
596 struct scatterlist *sg;
597 unsigned int i, j = 0;
598
599 while (!list_empty(&ctx->tsgl_list)) {
600 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
601 list);
602 sg = sgl->sg;
603
604 for (i = 0; i < sgl->cur; i++) {
605 size_t plen = min_t(size_t, used, sg[i].length);
606 struct page *page = sg_page(sg + i);
607
608 if (!page)
609 continue;
610
611 /*
612 * Assumption: caller created af_alg_count_tsgl(len)
613 * SG entries in dst.
614 */
615 if (dst) {
616 if (dst_offset >= plen) {
617 /* discard page before offset */
618 dst_offset -= plen;
619 } else {
620 /* reassign page to dst after offset */
621 get_page(page);
622 sg_set_page(dst + j, page,
623 plen - dst_offset,
624 sg[i].offset + dst_offset);
625 dst_offset = 0;
626 j++;
627 }
628 }
629
630 sg[i].length -= plen;
631 sg[i].offset += plen;
632
633 used -= plen;
634 ctx->used -= plen;
635
636 if (sg[i].length)
637 return;
638
639 put_page(page);
640 sg_assign_page(sg + i, NULL);
641 }
642
643 list_del(&sgl->list);
644 sock_kfree_s(sk, sgl, struct_size(sgl, sg, MAX_SGL_ENTS + 1));
645 }
646
647 if (!ctx->used)
648 ctx->merge = 0;
649 ctx->init = ctx->more;
650 }
651 EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
652
653 /**
654 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
655 *
656 * @areq Request holding the TX and RX SGL
657 */
af_alg_free_areq_sgls(struct af_alg_async_req * areq)658 static void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
659 {
660 struct sock *sk = areq->sk;
661 struct alg_sock *ask = alg_sk(sk);
662 struct af_alg_ctx *ctx = ask->private;
663 struct af_alg_rsgl *rsgl, *tmp;
664 struct scatterlist *tsgl;
665 struct scatterlist *sg;
666 unsigned int i;
667
668 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
669 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
670 af_alg_free_sg(&rsgl->sgl);
671 list_del(&rsgl->list);
672 if (rsgl != &areq->first_rsgl)
673 sock_kfree_s(sk, rsgl, sizeof(*rsgl));
674 }
675
676 tsgl = areq->tsgl;
677 if (tsgl) {
678 for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
679 if (!sg_page(sg))
680 continue;
681 put_page(sg_page(sg));
682 }
683
684 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
685 }
686 }
687
688 /**
689 * af_alg_wait_for_wmem - wait for availability of writable memory
690 *
691 * @sk socket of connection to user space
692 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
693 * @return 0 when writable memory is available, < 0 upon error
694 */
af_alg_wait_for_wmem(struct sock * sk,unsigned int flags)695 static int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
696 {
697 DEFINE_WAIT_FUNC(wait, woken_wake_function);
698 int err = -ERESTARTSYS;
699 long timeout;
700
701 if (flags & MSG_DONTWAIT)
702 return -EAGAIN;
703
704 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
705
706 add_wait_queue(sk_sleep(sk), &wait);
707 for (;;) {
708 if (signal_pending(current))
709 break;
710 timeout = MAX_SCHEDULE_TIMEOUT;
711 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
712 err = 0;
713 break;
714 }
715 }
716 remove_wait_queue(sk_sleep(sk), &wait);
717
718 return err;
719 }
720
721 /**
722 * af_alg_wmem_wakeup - wakeup caller when writable memory is available
723 *
724 * @sk socket of connection to user space
725 */
af_alg_wmem_wakeup(struct sock * sk)726 void af_alg_wmem_wakeup(struct sock *sk)
727 {
728 struct socket_wq *wq;
729
730 if (!af_alg_writable(sk))
731 return;
732
733 rcu_read_lock();
734 wq = rcu_dereference(sk->sk_wq);
735 if (skwq_has_sleeper(wq))
736 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN |
737 EPOLLRDNORM |
738 EPOLLRDBAND);
739 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
740 rcu_read_unlock();
741 }
742 EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
743
744 /**
745 * af_alg_wait_for_data - wait for availability of TX data
746 *
747 * @sk socket of connection to user space
748 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
749 * @min Set to minimum request size if partial requests are allowed.
750 * @return 0 when writable memory is available, < 0 upon error
751 */
af_alg_wait_for_data(struct sock * sk,unsigned flags,unsigned min)752 int af_alg_wait_for_data(struct sock *sk, unsigned flags, unsigned min)
753 {
754 DEFINE_WAIT_FUNC(wait, woken_wake_function);
755 struct alg_sock *ask = alg_sk(sk);
756 struct af_alg_ctx *ctx = ask->private;
757 long timeout;
758 int err = -ERESTARTSYS;
759
760 if (flags & MSG_DONTWAIT)
761 return -EAGAIN;
762
763 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
764
765 add_wait_queue(sk_sleep(sk), &wait);
766 for (;;) {
767 if (signal_pending(current))
768 break;
769 timeout = MAX_SCHEDULE_TIMEOUT;
770 if (sk_wait_event(sk, &timeout,
771 ctx->init && (!ctx->more ||
772 (min && ctx->used >= min)),
773 &wait)) {
774 err = 0;
775 break;
776 }
777 }
778 remove_wait_queue(sk_sleep(sk), &wait);
779
780 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
781
782 return err;
783 }
784 EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
785
786 /**
787 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
788 *
789 * @sk socket of connection to user space
790 */
af_alg_data_wakeup(struct sock * sk)791 static void af_alg_data_wakeup(struct sock *sk)
792 {
793 struct alg_sock *ask = alg_sk(sk);
794 struct af_alg_ctx *ctx = ask->private;
795 struct socket_wq *wq;
796
797 if (!ctx->used)
798 return;
799
800 rcu_read_lock();
801 wq = rcu_dereference(sk->sk_wq);
802 if (skwq_has_sleeper(wq))
803 wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
804 EPOLLRDNORM |
805 EPOLLRDBAND);
806 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
807 rcu_read_unlock();
808 }
809
810 /**
811 * af_alg_sendmsg - implementation of sendmsg system call handler
812 *
813 * The sendmsg system call handler obtains the user data and stores it
814 * in ctx->tsgl_list. This implies allocation of the required numbers of
815 * struct af_alg_tsgl.
816 *
817 * In addition, the ctx is filled with the information sent via CMSG.
818 *
819 * @sock socket of connection to user space
820 * @msg message from user space
821 * @size size of message from user space
822 * @ivsize the size of the IV for the cipher operation to verify that the
823 * user-space-provided IV has the right size
824 * @return the number of copied data upon success, < 0 upon error
825 */
af_alg_sendmsg(struct socket * sock,struct msghdr * msg,size_t size,unsigned int ivsize)826 int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
827 unsigned int ivsize)
828 {
829 struct sock *sk = sock->sk;
830 struct alg_sock *ask = alg_sk(sk);
831 struct af_alg_ctx *ctx = ask->private;
832 struct af_alg_tsgl *sgl;
833 struct af_alg_control con = {};
834 long copied = 0;
835 bool enc = false;
836 bool init = false;
837 int err = 0;
838
839 if (msg->msg_controllen) {
840 err = af_alg_cmsg_send(msg, &con);
841 if (err)
842 return err;
843
844 init = true;
845 switch (con.op) {
846 case ALG_OP_ENCRYPT:
847 enc = true;
848 break;
849 case ALG_OP_DECRYPT:
850 enc = false;
851 break;
852 default:
853 return -EINVAL;
854 }
855
856 if (con.iv && con.iv->ivlen != ivsize)
857 return -EINVAL;
858 }
859
860 lock_sock(sk);
861 if (ctx->init && !ctx->more) {
862 if (ctx->used) {
863 err = -EINVAL;
864 goto unlock;
865 }
866
867 pr_info_once(
868 "%s sent an empty control message without MSG_MORE.\n",
869 current->comm);
870 }
871 ctx->init = true;
872
873 if (init) {
874 ctx->enc = enc;
875 if (con.iv)
876 memcpy(ctx->iv, con.iv->iv, ivsize);
877
878 ctx->aead_assoclen = con.aead_assoclen;
879 }
880
881 while (size) {
882 struct scatterlist *sg;
883 size_t len = size;
884 size_t plen;
885
886 /* use the existing memory in an allocated page */
887 if (ctx->merge) {
888 sgl = list_entry(ctx->tsgl_list.prev,
889 struct af_alg_tsgl, list);
890 sg = sgl->sg + sgl->cur - 1;
891 len = min_t(size_t, len,
892 PAGE_SIZE - sg->offset - sg->length);
893
894 err = memcpy_from_msg(page_address(sg_page(sg)) +
895 sg->offset + sg->length,
896 msg, len);
897 if (err)
898 goto unlock;
899
900 sg->length += len;
901 ctx->merge = (sg->offset + sg->length) &
902 (PAGE_SIZE - 1);
903
904 ctx->used += len;
905 copied += len;
906 size -= len;
907 continue;
908 }
909
910 if (!af_alg_writable(sk)) {
911 err = af_alg_wait_for_wmem(sk, msg->msg_flags);
912 if (err)
913 goto unlock;
914 }
915
916 /* allocate a new page */
917 len = min_t(unsigned long, len, af_alg_sndbuf(sk));
918
919 err = af_alg_alloc_tsgl(sk);
920 if (err)
921 goto unlock;
922
923 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
924 list);
925 sg = sgl->sg;
926 if (sgl->cur)
927 sg_unmark_end(sg + sgl->cur - 1);
928
929 do {
930 unsigned int i = sgl->cur;
931
932 plen = min_t(size_t, len, PAGE_SIZE);
933
934 sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
935 if (!sg_page(sg + i)) {
936 err = -ENOMEM;
937 goto unlock;
938 }
939
940 err = memcpy_from_msg(page_address(sg_page(sg + i)),
941 msg, plen);
942 if (err) {
943 __free_page(sg_page(sg + i));
944 sg_assign_page(sg + i, NULL);
945 goto unlock;
946 }
947
948 sg[i].length = plen;
949 len -= plen;
950 ctx->used += plen;
951 copied += plen;
952 size -= plen;
953 sgl->cur++;
954 } while (len && sgl->cur < MAX_SGL_ENTS);
955
956 if (!size)
957 sg_mark_end(sg + sgl->cur - 1);
958
959 ctx->merge = plen & (PAGE_SIZE - 1);
960 }
961
962 err = 0;
963
964 ctx->more = msg->msg_flags & MSG_MORE;
965
966 unlock:
967 af_alg_data_wakeup(sk);
968 release_sock(sk);
969
970 return copied ?: err;
971 }
972 EXPORT_SYMBOL_GPL(af_alg_sendmsg);
973
974 /**
975 * af_alg_sendpage - sendpage system call handler
976 *
977 * This is a generic implementation of sendpage to fill ctx->tsgl_list.
978 */
af_alg_sendpage(struct socket * sock,struct page * page,int offset,size_t size,int flags)979 ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
980 int offset, size_t size, int flags)
981 {
982 struct sock *sk = sock->sk;
983 struct alg_sock *ask = alg_sk(sk);
984 struct af_alg_ctx *ctx = ask->private;
985 struct af_alg_tsgl *sgl;
986 int err = -EINVAL;
987
988 if (flags & MSG_SENDPAGE_NOTLAST)
989 flags |= MSG_MORE;
990
991 lock_sock(sk);
992 if (!ctx->more && ctx->used)
993 goto unlock;
994
995 if (!size)
996 goto done;
997
998 if (!af_alg_writable(sk)) {
999 err = af_alg_wait_for_wmem(sk, flags);
1000 if (err)
1001 goto unlock;
1002 }
1003
1004 err = af_alg_alloc_tsgl(sk);
1005 if (err)
1006 goto unlock;
1007
1008 ctx->merge = 0;
1009 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
1010
1011 if (sgl->cur)
1012 sg_unmark_end(sgl->sg + sgl->cur - 1);
1013
1014 sg_mark_end(sgl->sg + sgl->cur);
1015
1016 get_page(page);
1017 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
1018 sgl->cur++;
1019 ctx->used += size;
1020
1021 done:
1022 ctx->more = flags & MSG_MORE;
1023
1024 unlock:
1025 af_alg_data_wakeup(sk);
1026 release_sock(sk);
1027
1028 return err ?: size;
1029 }
1030 EXPORT_SYMBOL_GPL(af_alg_sendpage);
1031
1032 /**
1033 * af_alg_free_resources - release resources required for crypto request
1034 */
af_alg_free_resources(struct af_alg_async_req * areq)1035 void af_alg_free_resources(struct af_alg_async_req *areq)
1036 {
1037 struct sock *sk = areq->sk;
1038
1039 af_alg_free_areq_sgls(areq);
1040 sock_kfree_s(sk, areq, areq->areqlen);
1041 }
1042 EXPORT_SYMBOL_GPL(af_alg_free_resources);
1043
1044 /**
1045 * af_alg_async_cb - AIO callback handler
1046 *
1047 * This handler cleans up the struct af_alg_async_req upon completion of the
1048 * AIO operation.
1049 *
1050 * The number of bytes to be generated with the AIO operation must be set
1051 * in areq->outlen before the AIO callback handler is invoked.
1052 */
af_alg_async_cb(struct crypto_async_request * _req,int err)1053 void af_alg_async_cb(struct crypto_async_request *_req, int err)
1054 {
1055 struct af_alg_async_req *areq = _req->data;
1056 struct sock *sk = areq->sk;
1057 struct kiocb *iocb = areq->iocb;
1058 unsigned int resultlen;
1059
1060 /* Buffer size written by crypto operation. */
1061 resultlen = areq->outlen;
1062
1063 af_alg_free_resources(areq);
1064 sock_put(sk);
1065
1066 iocb->ki_complete(iocb, err ? err : (int)resultlen, 0);
1067 }
1068 EXPORT_SYMBOL_GPL(af_alg_async_cb);
1069
1070 /**
1071 * af_alg_poll - poll system call handler
1072 */
af_alg_poll(struct file * file,struct socket * sock,poll_table * wait)1073 __poll_t af_alg_poll(struct file *file, struct socket *sock,
1074 poll_table *wait)
1075 {
1076 struct sock *sk = sock->sk;
1077 struct alg_sock *ask = alg_sk(sk);
1078 struct af_alg_ctx *ctx = ask->private;
1079 __poll_t mask;
1080
1081 sock_poll_wait(file, sock, wait);
1082 mask = 0;
1083
1084 if (!ctx->more || ctx->used)
1085 mask |= EPOLLIN | EPOLLRDNORM;
1086
1087 if (af_alg_writable(sk))
1088 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1089
1090 return mask;
1091 }
1092 EXPORT_SYMBOL_GPL(af_alg_poll);
1093
1094 /**
1095 * af_alg_alloc_areq - allocate struct af_alg_async_req
1096 *
1097 * @sk socket of connection to user space
1098 * @areqlen size of struct af_alg_async_req + crypto_*_reqsize
1099 * @return allocated data structure or ERR_PTR upon error
1100 */
af_alg_alloc_areq(struct sock * sk,unsigned int areqlen)1101 struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
1102 unsigned int areqlen)
1103 {
1104 struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
1105
1106 if (unlikely(!areq))
1107 return ERR_PTR(-ENOMEM);
1108
1109 areq->areqlen = areqlen;
1110 areq->sk = sk;
1111 areq->last_rsgl = NULL;
1112 INIT_LIST_HEAD(&areq->rsgl_list);
1113 areq->tsgl = NULL;
1114 areq->tsgl_entries = 0;
1115
1116 return areq;
1117 }
1118 EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
1119
1120 /**
1121 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1122 * operation
1123 *
1124 * @sk socket of connection to user space
1125 * @msg user space message
1126 * @flags flags used to invoke recvmsg with
1127 * @areq instance of the cryptographic request that will hold the RX SGL
1128 * @maxsize maximum number of bytes to be pulled from user space
1129 * @outlen number of bytes in the RX SGL
1130 * @return 0 on success, < 0 upon error
1131 */
af_alg_get_rsgl(struct sock * sk,struct msghdr * msg,int flags,struct af_alg_async_req * areq,size_t maxsize,size_t * outlen)1132 int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
1133 struct af_alg_async_req *areq, size_t maxsize,
1134 size_t *outlen)
1135 {
1136 struct alg_sock *ask = alg_sk(sk);
1137 struct af_alg_ctx *ctx = ask->private;
1138 size_t len = 0;
1139
1140 while (maxsize > len && msg_data_left(msg)) {
1141 struct af_alg_rsgl *rsgl;
1142 size_t seglen;
1143 int err;
1144
1145 /* limit the amount of readable buffers */
1146 if (!af_alg_readable(sk))
1147 break;
1148
1149 seglen = min_t(size_t, (maxsize - len),
1150 msg_data_left(msg));
1151
1152 if (list_empty(&areq->rsgl_list)) {
1153 rsgl = &areq->first_rsgl;
1154 } else {
1155 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
1156 if (unlikely(!rsgl))
1157 return -ENOMEM;
1158 }
1159
1160 rsgl->sgl.npages = 0;
1161 list_add_tail(&rsgl->list, &areq->rsgl_list);
1162
1163 /* make one iovec available as scatterlist */
1164 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
1165 if (err < 0) {
1166 rsgl->sg_num_bytes = 0;
1167 return err;
1168 }
1169
1170 /* chain the new scatterlist with previous one */
1171 if (areq->last_rsgl)
1172 af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
1173
1174 areq->last_rsgl = rsgl;
1175 len += err;
1176 atomic_add(err, &ctx->rcvused);
1177 rsgl->sg_num_bytes = err;
1178 iov_iter_advance(&msg->msg_iter, err);
1179 }
1180
1181 *outlen = len;
1182 return 0;
1183 }
1184 EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
1185
af_alg_init(void)1186 static int __init af_alg_init(void)
1187 {
1188 int err = proto_register(&alg_proto, 0);
1189
1190 if (err)
1191 goto out;
1192
1193 err = sock_register(&alg_family);
1194 if (err != 0)
1195 goto out_unregister_proto;
1196
1197 out:
1198 return err;
1199
1200 out_unregister_proto:
1201 proto_unregister(&alg_proto);
1202 goto out;
1203 }
1204
af_alg_exit(void)1205 static void __exit af_alg_exit(void)
1206 {
1207 sock_unregister(PF_ALG);
1208 proto_unregister(&alg_proto);
1209 }
1210
1211 module_init(af_alg_init);
1212 module_exit(af_alg_exit);
1213 MODULE_LICENSE("GPL");
1214 MODULE_ALIAS_NETPROTO(AF_ALG);
1215
