1 /*
2 * af_alg: User-space algorithm interface
3 *
4 * This file provides the user-space API for algorithms.
5 *
6 * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the Free
10 * Software Foundation; either version 2 of the License, or (at your option)
11 * any later version.
12 *
13 */
14
15 #include <linux/atomic.h>
16 #include <crypto/if_alg.h>
17 #include <linux/crypto.h>
18 #include <linux/init.h>
19 #include <linux/kernel.h>
20 #include <linux/list.h>
21 #include <linux/module.h>
22 #include <linux/net.h>
23 #include <linux/rwsem.h>
24 #include <linux/sched/signal.h>
25 #include <linux/security.h>
26
27 struct alg_type_list {
28 const struct af_alg_type *type;
29 struct list_head list;
30 };
31
32 static atomic_long_t alg_memory_allocated;
33
34 static struct proto alg_proto = {
35 .name = "ALG",
36 .owner = THIS_MODULE,
37 .memory_allocated = &alg_memory_allocated,
38 .obj_size = sizeof(struct alg_sock),
39 };
40
41 static LIST_HEAD(alg_types);
42 static DECLARE_RWSEM(alg_types_sem);
43
alg_get_type(const char * name)44 static const struct af_alg_type *alg_get_type(const char *name)
45 {
46 const struct af_alg_type *type = ERR_PTR(-ENOENT);
47 struct alg_type_list *node;
48
49 down_read(&alg_types_sem);
50 list_for_each_entry(node, &alg_types, list) {
51 if (strcmp(node->type->name, name))
52 continue;
53
54 if (try_module_get(node->type->owner))
55 type = node->type;
56 break;
57 }
58 up_read(&alg_types_sem);
59
60 return type;
61 }
62
af_alg_register_type(const struct af_alg_type * type)63 int af_alg_register_type(const struct af_alg_type *type)
64 {
65 struct alg_type_list *node;
66 int err = -EEXIST;
67
68 down_write(&alg_types_sem);
69 list_for_each_entry(node, &alg_types, list) {
70 if (!strcmp(node->type->name, type->name))
71 goto unlock;
72 }
73
74 node = kmalloc(sizeof(*node), GFP_KERNEL);
75 err = -ENOMEM;
76 if (!node)
77 goto unlock;
78
79 type->ops->owner = THIS_MODULE;
80 if (type->ops_nokey)
81 type->ops_nokey->owner = THIS_MODULE;
82 node->type = type;
83 list_add(&node->list, &alg_types);
84 err = 0;
85
86 unlock:
87 up_write(&alg_types_sem);
88
89 return err;
90 }
91 EXPORT_SYMBOL_GPL(af_alg_register_type);
92
af_alg_unregister_type(const struct af_alg_type * type)93 int af_alg_unregister_type(const struct af_alg_type *type)
94 {
95 struct alg_type_list *node;
96 int err = -ENOENT;
97
98 down_write(&alg_types_sem);
99 list_for_each_entry(node, &alg_types, list) {
100 if (strcmp(node->type->name, type->name))
101 continue;
102
103 list_del(&node->list);
104 kfree(node);
105 err = 0;
106 break;
107 }
108 up_write(&alg_types_sem);
109
110 return err;
111 }
112 EXPORT_SYMBOL_GPL(af_alg_unregister_type);
113
alg_do_release(const struct af_alg_type * type,void * private)114 static void alg_do_release(const struct af_alg_type *type, void *private)
115 {
116 if (!type)
117 return;
118
119 type->release(private);
120 module_put(type->owner);
121 }
122
af_alg_release(struct socket * sock)123 int af_alg_release(struct socket *sock)
124 {
125 if (sock->sk)
126 sock_put(sock->sk);
127 return 0;
128 }
129 EXPORT_SYMBOL_GPL(af_alg_release);
130
af_alg_release_parent(struct sock * sk)131 void af_alg_release_parent(struct sock *sk)
132 {
133 struct alg_sock *ask = alg_sk(sk);
134 unsigned int nokey = ask->nokey_refcnt;
135 bool last = nokey && !ask->refcnt;
136
137 sk = ask->parent;
138 ask = alg_sk(sk);
139
140 lock_sock(sk);
141 ask->nokey_refcnt -= nokey;
142 if (!last)
143 last = !--ask->refcnt;
144 release_sock(sk);
145
146 if (last)
147 sock_put(sk);
148 }
149 EXPORT_SYMBOL_GPL(af_alg_release_parent);
150
alg_bind(struct socket * sock,struct sockaddr * uaddr,int addr_len)151 static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
152 {
153 const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY;
154 struct sock *sk = sock->sk;
155 struct alg_sock *ask = alg_sk(sk);
156 struct sockaddr_alg *sa = (void *)uaddr;
157 const struct af_alg_type *type;
158 void *private;
159 int err;
160
161 if (sock->state == SS_CONNECTED)
162 return -EINVAL;
163
164 if (addr_len < sizeof(*sa))
165 return -EINVAL;
166
167 /* If caller uses non-allowed flag, return error. */
168 if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed))
169 return -EINVAL;
170
171 sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
172 sa->salg_name[sizeof(sa->salg_name) + addr_len - sizeof(*sa) - 1] = 0;
173
174 type = alg_get_type(sa->salg_type);
175 if (IS_ERR(type) && PTR_ERR(type) == -ENOENT) {
176 request_module("algif-%s", sa->salg_type);
177 type = alg_get_type(sa->salg_type);
178 }
179
180 if (IS_ERR(type))
181 return PTR_ERR(type);
182
183 private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask);
184 if (IS_ERR(private)) {
185 module_put(type->owner);
186 return PTR_ERR(private);
187 }
188
189 err = -EBUSY;
190 lock_sock(sk);
191 if (ask->refcnt | ask->nokey_refcnt)
192 goto unlock;
193
194 swap(ask->type, type);
195 swap(ask->private, private);
196
197 err = 0;
198
199 unlock:
200 release_sock(sk);
201
202 alg_do_release(type, private);
203
204 return err;
205 }
206
alg_setkey(struct sock * sk,char __user * ukey,unsigned int keylen)207 static int alg_setkey(struct sock *sk, char __user *ukey,
208 unsigned int keylen)
209 {
210 struct alg_sock *ask = alg_sk(sk);
211 const struct af_alg_type *type = ask->type;
212 u8 *key;
213 int err;
214
215 key = sock_kmalloc(sk, keylen, GFP_KERNEL);
216 if (!key)
217 return -ENOMEM;
218
219 err = -EFAULT;
220 if (copy_from_user(key, ukey, keylen))
221 goto out;
222
223 err = type->setkey(ask->private, key, keylen);
224
225 out:
226 sock_kzfree_s(sk, key, keylen);
227
228 return err;
229 }
230
alg_setsockopt(struct socket * sock,int level,int optname,char __user * optval,unsigned int optlen)231 static int alg_setsockopt(struct socket *sock, int level, int optname,
232 char __user *optval, unsigned int optlen)
233 {
234 struct sock *sk = sock->sk;
235 struct alg_sock *ask = alg_sk(sk);
236 const struct af_alg_type *type;
237 int err = -EBUSY;
238
239 lock_sock(sk);
240 if (ask->refcnt)
241 goto unlock;
242
243 type = ask->type;
244
245 err = -ENOPROTOOPT;
246 if (level != SOL_ALG || !type)
247 goto unlock;
248
249 switch (optname) {
250 case ALG_SET_KEY:
251 if (sock->state == SS_CONNECTED)
252 goto unlock;
253 if (!type->setkey)
254 goto unlock;
255
256 err = alg_setkey(sk, optval, optlen);
257 break;
258 case ALG_SET_AEAD_AUTHSIZE:
259 if (sock->state == SS_CONNECTED)
260 goto unlock;
261 if (!type->setauthsize)
262 goto unlock;
263 err = type->setauthsize(ask->private, optlen);
264 }
265
266 unlock:
267 release_sock(sk);
268
269 return err;
270 }
271
af_alg_accept(struct sock * sk,struct socket * newsock,bool kern)272 int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern)
273 {
274 struct alg_sock *ask = alg_sk(sk);
275 const struct af_alg_type *type;
276 struct sock *sk2;
277 unsigned int nokey;
278 int err;
279
280 lock_sock(sk);
281 type = ask->type;
282
283 err = -EINVAL;
284 if (!type)
285 goto unlock;
286
287 sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, kern);
288 err = -ENOMEM;
289 if (!sk2)
290 goto unlock;
291
292 sock_init_data(newsock, sk2);
293 security_sock_graft(sk2, newsock);
294 security_sk_clone(sk, sk2);
295
296 err = type->accept(ask->private, sk2);
297
298 nokey = err == -ENOKEY;
299 if (nokey && type->accept_nokey)
300 err = type->accept_nokey(ask->private, sk2);
301
302 if (err)
303 goto unlock;
304
305 sk2->sk_family = PF_ALG;
306
307 if (nokey || !ask->refcnt++)
308 sock_hold(sk);
309 ask->nokey_refcnt += nokey;
310 alg_sk(sk2)->parent = sk;
311 alg_sk(sk2)->type = type;
312 alg_sk(sk2)->nokey_refcnt = nokey;
313
314 newsock->ops = type->ops;
315 newsock->state = SS_CONNECTED;
316
317 if (nokey)
318 newsock->ops = type->ops_nokey;
319
320 err = 0;
321
322 unlock:
323 release_sock(sk);
324
325 return err;
326 }
327 EXPORT_SYMBOL_GPL(af_alg_accept);
328
alg_accept(struct socket * sock,struct socket * newsock,int flags,bool kern)329 static int alg_accept(struct socket *sock, struct socket *newsock, int flags,
330 bool kern)
331 {
332 return af_alg_accept(sock->sk, newsock, kern);
333 }
334
335 static const struct proto_ops alg_proto_ops = {
336 .family = PF_ALG,
337 .owner = THIS_MODULE,
338
339 .connect = sock_no_connect,
340 .socketpair = sock_no_socketpair,
341 .getname = sock_no_getname,
342 .ioctl = sock_no_ioctl,
343 .listen = sock_no_listen,
344 .shutdown = sock_no_shutdown,
345 .getsockopt = sock_no_getsockopt,
346 .mmap = sock_no_mmap,
347 .sendpage = sock_no_sendpage,
348 .sendmsg = sock_no_sendmsg,
349 .recvmsg = sock_no_recvmsg,
350
351 .bind = alg_bind,
352 .release = af_alg_release,
353 .setsockopt = alg_setsockopt,
354 .accept = alg_accept,
355 };
356
alg_sock_destruct(struct sock * sk)357 static void alg_sock_destruct(struct sock *sk)
358 {
359 struct alg_sock *ask = alg_sk(sk);
360
361 alg_do_release(ask->type, ask->private);
362 }
363
alg_create(struct net * net,struct socket * sock,int protocol,int kern)364 static int alg_create(struct net *net, struct socket *sock, int protocol,
365 int kern)
366 {
367 struct sock *sk;
368 int err;
369
370 if (sock->type != SOCK_SEQPACKET)
371 return -ESOCKTNOSUPPORT;
372 if (protocol != 0)
373 return -EPROTONOSUPPORT;
374
375 err = -ENOMEM;
376 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
377 if (!sk)
378 goto out;
379
380 sock->ops = &alg_proto_ops;
381 sock_init_data(sock, sk);
382
383 sk->sk_family = PF_ALG;
384 sk->sk_destruct = alg_sock_destruct;
385
386 return 0;
387 out:
388 return err;
389 }
390
391 static const struct net_proto_family alg_family = {
392 .family = PF_ALG,
393 .create = alg_create,
394 .owner = THIS_MODULE,
395 };
396
af_alg_make_sg(struct af_alg_sgl * sgl,struct iov_iter * iter,int len)397 int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
398 {
399 size_t off;
400 ssize_t n;
401 int npages, i;
402
403 n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
404 if (n < 0)
405 return n;
406
407 npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT;
408 if (WARN_ON(npages == 0))
409 return -EINVAL;
410 /* Add one extra for linking */
411 sg_init_table(sgl->sg, npages + 1);
412
413 for (i = 0, len = n; i < npages; i++) {
414 int plen = min_t(int, len, PAGE_SIZE - off);
415
416 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
417
418 off = 0;
419 len -= plen;
420 }
421 sg_mark_end(sgl->sg + npages - 1);
422 sgl->npages = npages;
423
424 return n;
425 }
426 EXPORT_SYMBOL_GPL(af_alg_make_sg);
427
af_alg_link_sg(struct af_alg_sgl * sgl_prev,struct af_alg_sgl * sgl_new)428 void af_alg_link_sg(struct af_alg_sgl *sgl_prev, struct af_alg_sgl *sgl_new)
429 {
430 sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
431 sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
432 }
433 EXPORT_SYMBOL_GPL(af_alg_link_sg);
434
af_alg_free_sg(struct af_alg_sgl * sgl)435 void af_alg_free_sg(struct af_alg_sgl *sgl)
436 {
437 int i;
438
439 for (i = 0; i < sgl->npages; i++)
440 put_page(sgl->pages[i]);
441 }
442 EXPORT_SYMBOL_GPL(af_alg_free_sg);
443
af_alg_cmsg_send(struct msghdr * msg,struct af_alg_control * con)444 int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
445 {
446 struct cmsghdr *cmsg;
447
448 for_each_cmsghdr(cmsg, msg) {
449 if (!CMSG_OK(msg, cmsg))
450 return -EINVAL;
451 if (cmsg->cmsg_level != SOL_ALG)
452 continue;
453
454 switch (cmsg->cmsg_type) {
455 case ALG_SET_IV:
456 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
457 return -EINVAL;
458 con->iv = (void *)CMSG_DATA(cmsg);
459 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
460 sizeof(*con->iv)))
461 return -EINVAL;
462 break;
463
464 case ALG_SET_OP:
465 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
466 return -EINVAL;
467 con->op = *(u32 *)CMSG_DATA(cmsg);
468 break;
469
470 case ALG_SET_AEAD_ASSOCLEN:
471 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
472 return -EINVAL;
473 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
474 break;
475
476 default:
477 return -EINVAL;
478 }
479 }
480
481 return 0;
482 }
483 EXPORT_SYMBOL_GPL(af_alg_cmsg_send);
484
485 /**
486 * af_alg_alloc_tsgl - allocate the TX SGL
487 *
488 * @sk socket of connection to user space
489 * @return: 0 upon success, < 0 upon error
490 */
af_alg_alloc_tsgl(struct sock * sk)491 int af_alg_alloc_tsgl(struct sock *sk)
492 {
493 struct alg_sock *ask = alg_sk(sk);
494 struct af_alg_ctx *ctx = ask->private;
495 struct af_alg_tsgl *sgl;
496 struct scatterlist *sg = NULL;
497
498 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
499 if (!list_empty(&ctx->tsgl_list))
500 sg = sgl->sg;
501
502 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
503 sgl = sock_kmalloc(sk,
504 struct_size(sgl, sg, (MAX_SGL_ENTS + 1)),
505 GFP_KERNEL);
506 if (!sgl)
507 return -ENOMEM;
508
509 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
510 sgl->cur = 0;
511
512 if (sg)
513 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
514
515 list_add_tail(&sgl->list, &ctx->tsgl_list);
516 }
517
518 return 0;
519 }
520 EXPORT_SYMBOL_GPL(af_alg_alloc_tsgl);
521
522 /**
523 * aead_count_tsgl - Count number of TX SG entries
524 *
525 * The counting starts from the beginning of the SGL to @bytes. If
526 * an offset is provided, the counting of the SG entries starts at the offset.
527 *
528 * @sk socket of connection to user space
529 * @bytes Count the number of SG entries holding given number of bytes.
530 * @offset Start the counting of SG entries from the given offset.
531 * @return Number of TX SG entries found given the constraints
532 */
af_alg_count_tsgl(struct sock * sk,size_t bytes,size_t offset)533 unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
534 {
535 struct alg_sock *ask = alg_sk(sk);
536 struct af_alg_ctx *ctx = ask->private;
537 struct af_alg_tsgl *sgl, *tmp;
538 unsigned int i;
539 unsigned int sgl_count = 0;
540
541 if (!bytes)
542 return 0;
543
544 list_for_each_entry_safe(sgl, tmp, &ctx->tsgl_list, list) {
545 struct scatterlist *sg = sgl->sg;
546
547 for (i = 0; i < sgl->cur; i++) {
548 size_t bytes_count;
549
550 /* Skip offset */
551 if (offset >= sg[i].length) {
552 offset -= sg[i].length;
553 bytes -= sg[i].length;
554 continue;
555 }
556
557 bytes_count = sg[i].length - offset;
558
559 offset = 0;
560 sgl_count++;
561
562 /* If we have seen requested number of bytes, stop */
563 if (bytes_count >= bytes)
564 return sgl_count;
565
566 bytes -= bytes_count;
567 }
568 }
569
570 return sgl_count;
571 }
572 EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
573
574 /**
575 * aead_pull_tsgl - Release the specified buffers from TX SGL
576 *
577 * If @dst is non-null, reassign the pages to dst. The caller must release
578 * the pages. If @dst_offset is given only reassign the pages to @dst starting
579 * at the @dst_offset (byte). The caller must ensure that @dst is large
580 * enough (e.g. by using af_alg_count_tsgl with the same offset).
581 *
582 * @sk socket of connection to user space
583 * @used Number of bytes to pull from TX SGL
584 * @dst If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
585 * caller must release the buffers in dst.
586 * @dst_offset Reassign the TX SGL from given offset. All buffers before
587 * reaching the offset is released.
588 */
af_alg_pull_tsgl(struct sock * sk,size_t used,struct scatterlist * dst,size_t dst_offset)589 void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
590 size_t dst_offset)
591 {
592 struct alg_sock *ask = alg_sk(sk);
593 struct af_alg_ctx *ctx = ask->private;
594 struct af_alg_tsgl *sgl;
595 struct scatterlist *sg;
596 unsigned int i, j = 0;
597
598 while (!list_empty(&ctx->tsgl_list)) {
599 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
600 list);
601 sg = sgl->sg;
602
603 for (i = 0; i < sgl->cur; i++) {
604 size_t plen = min_t(size_t, used, sg[i].length);
605 struct page *page = sg_page(sg + i);
606
607 if (!page)
608 continue;
609
610 /*
611 * Assumption: caller created af_alg_count_tsgl(len)
612 * SG entries in dst.
613 */
614 if (dst) {
615 if (dst_offset >= plen) {
616 /* discard page before offset */
617 dst_offset -= plen;
618 } else {
619 /* reassign page to dst after offset */
620 get_page(page);
621 sg_set_page(dst + j, page,
622 plen - dst_offset,
623 sg[i].offset + dst_offset);
624 dst_offset = 0;
625 j++;
626 }
627 }
628
629 sg[i].length -= plen;
630 sg[i].offset += plen;
631
632 used -= plen;
633 ctx->used -= plen;
634
635 if (sg[i].length)
636 return;
637
638 put_page(page);
639 sg_assign_page(sg + i, NULL);
640 }
641
642 list_del(&sgl->list);
643 sock_kfree_s(sk, sgl, sizeof(*sgl) + sizeof(sgl->sg[0]) *
644 (MAX_SGL_ENTS + 1));
645 }
646
647 if (!ctx->used)
648 ctx->merge = 0;
649 }
650 EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
651
652 /**
653 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
654 *
655 * @areq Request holding the TX and RX SGL
656 */
af_alg_free_areq_sgls(struct af_alg_async_req * areq)657 void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
658 {
659 struct sock *sk = areq->sk;
660 struct alg_sock *ask = alg_sk(sk);
661 struct af_alg_ctx *ctx = ask->private;
662 struct af_alg_rsgl *rsgl, *tmp;
663 struct scatterlist *tsgl;
664 struct scatterlist *sg;
665 unsigned int i;
666
667 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
668 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
669 af_alg_free_sg(&rsgl->sgl);
670 list_del(&rsgl->list);
671 if (rsgl != &areq->first_rsgl)
672 sock_kfree_s(sk, rsgl, sizeof(*rsgl));
673 }
674
675 tsgl = areq->tsgl;
676 if (tsgl) {
677 for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
678 if (!sg_page(sg))
679 continue;
680 put_page(sg_page(sg));
681 }
682
683 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
684 }
685 }
686 EXPORT_SYMBOL_GPL(af_alg_free_areq_sgls);
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 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 EXPORT_SYMBOL_GPL(af_alg_wait_for_wmem);
721
722 /**
723 * af_alg_wmem_wakeup - wakeup caller when writable memory is available
724 *
725 * @sk socket of connection to user space
726 */
af_alg_wmem_wakeup(struct sock * sk)727 void af_alg_wmem_wakeup(struct sock *sk)
728 {
729 struct socket_wq *wq;
730
731 if (!af_alg_writable(sk))
732 return;
733
734 rcu_read_lock();
735 wq = rcu_dereference(sk->sk_wq);
736 if (skwq_has_sleeper(wq))
737 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN |
738 EPOLLRDNORM |
739 EPOLLRDBAND);
740 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
741 rcu_read_unlock();
742 }
743 EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
744
745 /**
746 * af_alg_wait_for_data - wait for availability of TX data
747 *
748 * @sk socket of connection to user space
749 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
750 * @return 0 when writable memory is available, < 0 upon error
751 */
af_alg_wait_for_data(struct sock * sk,unsigned flags)752 int af_alg_wait_for_data(struct sock *sk, unsigned flags)
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, (ctx->used || !ctx->more),
771 &wait)) {
772 err = 0;
773 break;
774 }
775 }
776 remove_wait_queue(sk_sleep(sk), &wait);
777
778 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
779
780 return err;
781 }
782 EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
783
784 /**
785 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
786 *
787 * @sk socket of connection to user space
788 */
789
af_alg_data_wakeup(struct sock * sk)790 void af_alg_data_wakeup(struct sock *sk)
791 {
792 struct alg_sock *ask = alg_sk(sk);
793 struct af_alg_ctx *ctx = ask->private;
794 struct socket_wq *wq;
795
796 if (!ctx->used)
797 return;
798
799 rcu_read_lock();
800 wq = rcu_dereference(sk->sk_wq);
801 if (skwq_has_sleeper(wq))
802 wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
803 EPOLLRDNORM |
804 EPOLLRDBAND);
805 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
806 rcu_read_unlock();
807 }
808 EXPORT_SYMBOL_GPL(af_alg_data_wakeup);
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 = 0;
836 bool init = 0;
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 = 1;
845 switch (con.op) {
846 case ALG_OP_ENCRYPT:
847 enc = 1;
848 break;
849 case ALG_OP_DECRYPT:
850 enc = 0;
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->more && ctx->used) {
862 err = -EINVAL;
863 goto unlock;
864 }
865
866 if (init) {
867 ctx->enc = enc;
868 if (con.iv)
869 memcpy(ctx->iv, con.iv->iv, ivsize);
870
871 ctx->aead_assoclen = con.aead_assoclen;
872 }
873
874 while (size) {
875 struct scatterlist *sg;
876 size_t len = size;
877 size_t plen;
878
879 /* use the existing memory in an allocated page */
880 if (ctx->merge) {
881 sgl = list_entry(ctx->tsgl_list.prev,
882 struct af_alg_tsgl, list);
883 sg = sgl->sg + sgl->cur - 1;
884 len = min_t(size_t, len,
885 PAGE_SIZE - sg->offset - sg->length);
886
887 err = memcpy_from_msg(page_address(sg_page(sg)) +
888 sg->offset + sg->length,
889 msg, len);
890 if (err)
891 goto unlock;
892
893 sg->length += len;
894 ctx->merge = (sg->offset + sg->length) &
895 (PAGE_SIZE - 1);
896
897 ctx->used += len;
898 copied += len;
899 size -= len;
900 continue;
901 }
902
903 if (!af_alg_writable(sk)) {
904 err = af_alg_wait_for_wmem(sk, msg->msg_flags);
905 if (err)
906 goto unlock;
907 }
908
909 /* allocate a new page */
910 len = min_t(unsigned long, len, af_alg_sndbuf(sk));
911
912 err = af_alg_alloc_tsgl(sk);
913 if (err)
914 goto unlock;
915
916 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
917 list);
918 sg = sgl->sg;
919 if (sgl->cur)
920 sg_unmark_end(sg + sgl->cur - 1);
921
922 do {
923 unsigned int i = sgl->cur;
924
925 plen = min_t(size_t, len, PAGE_SIZE);
926
927 sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
928 if (!sg_page(sg + i)) {
929 err = -ENOMEM;
930 goto unlock;
931 }
932
933 err = memcpy_from_msg(page_address(sg_page(sg + i)),
934 msg, plen);
935 if (err) {
936 __free_page(sg_page(sg + i));
937 sg_assign_page(sg + i, NULL);
938 goto unlock;
939 }
940
941 sg[i].length = plen;
942 len -= plen;
943 ctx->used += plen;
944 copied += plen;
945 size -= plen;
946 sgl->cur++;
947 } while (len && sgl->cur < MAX_SGL_ENTS);
948
949 if (!size)
950 sg_mark_end(sg + sgl->cur - 1);
951
952 ctx->merge = plen & (PAGE_SIZE - 1);
953 }
954
955 err = 0;
956
957 ctx->more = msg->msg_flags & MSG_MORE;
958
959 unlock:
960 af_alg_data_wakeup(sk);
961 release_sock(sk);
962
963 return copied ?: err;
964 }
965 EXPORT_SYMBOL_GPL(af_alg_sendmsg);
966
967 /**
968 * af_alg_sendpage - sendpage system call handler
969 *
970 * This is a generic implementation of sendpage to fill ctx->tsgl_list.
971 */
af_alg_sendpage(struct socket * sock,struct page * page,int offset,size_t size,int flags)972 ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
973 int offset, size_t size, int flags)
974 {
975 struct sock *sk = sock->sk;
976 struct alg_sock *ask = alg_sk(sk);
977 struct af_alg_ctx *ctx = ask->private;
978 struct af_alg_tsgl *sgl;
979 int err = -EINVAL;
980
981 if (flags & MSG_SENDPAGE_NOTLAST)
982 flags |= MSG_MORE;
983
984 lock_sock(sk);
985 if (!ctx->more && ctx->used)
986 goto unlock;
987
988 if (!size)
989 goto done;
990
991 if (!af_alg_writable(sk)) {
992 err = af_alg_wait_for_wmem(sk, flags);
993 if (err)
994 goto unlock;
995 }
996
997 err = af_alg_alloc_tsgl(sk);
998 if (err)
999 goto unlock;
1000
1001 ctx->merge = 0;
1002 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
1003
1004 if (sgl->cur)
1005 sg_unmark_end(sgl->sg + sgl->cur - 1);
1006
1007 sg_mark_end(sgl->sg + sgl->cur);
1008
1009 get_page(page);
1010 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
1011 sgl->cur++;
1012 ctx->used += size;
1013
1014 done:
1015 ctx->more = flags & MSG_MORE;
1016
1017 unlock:
1018 af_alg_data_wakeup(sk);
1019 release_sock(sk);
1020
1021 return err ?: size;
1022 }
1023 EXPORT_SYMBOL_GPL(af_alg_sendpage);
1024
1025 /**
1026 * af_alg_free_resources - release resources required for crypto request
1027 */
af_alg_free_resources(struct af_alg_async_req * areq)1028 void af_alg_free_resources(struct af_alg_async_req *areq)
1029 {
1030 struct sock *sk = areq->sk;
1031
1032 af_alg_free_areq_sgls(areq);
1033 sock_kfree_s(sk, areq, areq->areqlen);
1034 }
1035 EXPORT_SYMBOL_GPL(af_alg_free_resources);
1036
1037 /**
1038 * af_alg_async_cb - AIO callback handler
1039 *
1040 * This handler cleans up the struct af_alg_async_req upon completion of the
1041 * AIO operation.
1042 *
1043 * The number of bytes to be generated with the AIO operation must be set
1044 * in areq->outlen before the AIO callback handler is invoked.
1045 */
af_alg_async_cb(struct crypto_async_request * _req,int err)1046 void af_alg_async_cb(struct crypto_async_request *_req, int err)
1047 {
1048 struct af_alg_async_req *areq = _req->data;
1049 struct sock *sk = areq->sk;
1050 struct kiocb *iocb = areq->iocb;
1051 unsigned int resultlen;
1052
1053 /* Buffer size written by crypto operation. */
1054 resultlen = areq->outlen;
1055
1056 af_alg_free_resources(areq);
1057 sock_put(sk);
1058
1059 iocb->ki_complete(iocb, err ? err : resultlen, 0);
1060 }
1061 EXPORT_SYMBOL_GPL(af_alg_async_cb);
1062
1063 /**
1064 * af_alg_poll - poll system call handler
1065 */
af_alg_poll(struct file * file,struct socket * sock,poll_table * wait)1066 __poll_t af_alg_poll(struct file *file, struct socket *sock,
1067 poll_table *wait)
1068 {
1069 struct sock *sk = sock->sk;
1070 struct alg_sock *ask = alg_sk(sk);
1071 struct af_alg_ctx *ctx = ask->private;
1072 __poll_t mask;
1073
1074 sock_poll_wait(file, wait);
1075 mask = 0;
1076
1077 if (!ctx->more || ctx->used)
1078 mask |= EPOLLIN | EPOLLRDNORM;
1079
1080 if (af_alg_writable(sk))
1081 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1082
1083 return mask;
1084 }
1085 EXPORT_SYMBOL_GPL(af_alg_poll);
1086
1087 /**
1088 * af_alg_alloc_areq - allocate struct af_alg_async_req
1089 *
1090 * @sk socket of connection to user space
1091 * @areqlen size of struct af_alg_async_req + crypto_*_reqsize
1092 * @return allocated data structure or ERR_PTR upon error
1093 */
af_alg_alloc_areq(struct sock * sk,unsigned int areqlen)1094 struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
1095 unsigned int areqlen)
1096 {
1097 struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
1098
1099 if (unlikely(!areq))
1100 return ERR_PTR(-ENOMEM);
1101
1102 areq->areqlen = areqlen;
1103 areq->sk = sk;
1104 areq->last_rsgl = NULL;
1105 INIT_LIST_HEAD(&areq->rsgl_list);
1106 areq->tsgl = NULL;
1107 areq->tsgl_entries = 0;
1108
1109 return areq;
1110 }
1111 EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
1112
1113 /**
1114 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1115 * operation
1116 *
1117 * @sk socket of connection to user space
1118 * @msg user space message
1119 * @flags flags used to invoke recvmsg with
1120 * @areq instance of the cryptographic request that will hold the RX SGL
1121 * @maxsize maximum number of bytes to be pulled from user space
1122 * @outlen number of bytes in the RX SGL
1123 * @return 0 on success, < 0 upon error
1124 */
af_alg_get_rsgl(struct sock * sk,struct msghdr * msg,int flags,struct af_alg_async_req * areq,size_t maxsize,size_t * outlen)1125 int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
1126 struct af_alg_async_req *areq, size_t maxsize,
1127 size_t *outlen)
1128 {
1129 struct alg_sock *ask = alg_sk(sk);
1130 struct af_alg_ctx *ctx = ask->private;
1131 size_t len = 0;
1132
1133 while (maxsize > len && msg_data_left(msg)) {
1134 struct af_alg_rsgl *rsgl;
1135 size_t seglen;
1136 int err;
1137
1138 /* limit the amount of readable buffers */
1139 if (!af_alg_readable(sk))
1140 break;
1141
1142 seglen = min_t(size_t, (maxsize - len),
1143 msg_data_left(msg));
1144
1145 if (list_empty(&areq->rsgl_list)) {
1146 rsgl = &areq->first_rsgl;
1147 } else {
1148 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
1149 if (unlikely(!rsgl))
1150 return -ENOMEM;
1151 }
1152
1153 rsgl->sgl.npages = 0;
1154 list_add_tail(&rsgl->list, &areq->rsgl_list);
1155
1156 /* make one iovec available as scatterlist */
1157 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
1158 if (err < 0) {
1159 rsgl->sg_num_bytes = 0;
1160 return err;
1161 }
1162
1163 /* chain the new scatterlist with previous one */
1164 if (areq->last_rsgl)
1165 af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
1166
1167 areq->last_rsgl = rsgl;
1168 len += err;
1169 atomic_add(err, &ctx->rcvused);
1170 rsgl->sg_num_bytes = err;
1171 iov_iter_advance(&msg->msg_iter, err);
1172 }
1173
1174 *outlen = len;
1175 return 0;
1176 }
1177 EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
1178
af_alg_init(void)1179 static int __init af_alg_init(void)
1180 {
1181 int err = proto_register(&alg_proto, 0);
1182
1183 if (err)
1184 goto out;
1185
1186 err = sock_register(&alg_family);
1187 if (err != 0)
1188 goto out_unregister_proto;
1189
1190 out:
1191 return err;
1192
1193 out_unregister_proto:
1194 proto_unregister(&alg_proto);
1195 goto out;
1196 }
1197
af_alg_exit(void)1198 static void __exit af_alg_exit(void)
1199 {
1200 sock_unregister(PF_ALG);
1201 proto_unregister(&alg_proto);
1202 }
1203
1204 module_init(af_alg_init);
1205 module_exit(af_alg_exit);
1206 MODULE_LICENSE("GPL");
1207 MODULE_ALIAS_NETPROTO(AF_ALG);
1208
