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-rw-r--r--crypto/algif_skcipher.c640
1 files changed, 640 insertions, 0 deletions
diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c
new file mode 100644
index 000000000000..211c956952ca
--- /dev/null
+++ b/crypto/algif_skcipher.c
@@ -0,0 +1,640 @@
1/*
2 * algif_skcipher: User-space interface for skcipher algorithms
3 *
4 * This file provides the user-space API for symmetric key ciphers.
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 <crypto/scatterwalk.h>
16#include <crypto/skcipher.h>
17#include <crypto/if_alg.h>
18#include <linux/init.h>
19#include <linux/list.h>
20#include <linux/kernel.h>
21#include <linux/mm.h>
22#include <linux/module.h>
23#include <linux/net.h>
24#include <net/sock.h>
25
26struct skcipher_sg_list {
27 struct list_head list;
28
29 int cur;
30
31 struct scatterlist sg[0];
32};
33
34struct skcipher_ctx {
35 struct list_head tsgl;
36 struct af_alg_sgl rsgl;
37
38 void *iv;
39
40 struct af_alg_completion completion;
41
42 unsigned used;
43
44 unsigned int len;
45 bool more;
46 bool merge;
47 bool enc;
48
49 struct ablkcipher_request req;
50};
51
52#define MAX_SGL_ENTS ((PAGE_SIZE - sizeof(struct skcipher_sg_list)) / \
53 sizeof(struct scatterlist) - 1)
54
55static inline bool skcipher_writable(struct sock *sk)
56{
57 struct alg_sock *ask = alg_sk(sk);
58 struct skcipher_ctx *ctx = ask->private;
59
60 return ctx->used + PAGE_SIZE <= max_t(int, sk->sk_sndbuf, PAGE_SIZE);
61}
62
63static int skcipher_alloc_sgl(struct sock *sk)
64{
65 struct alg_sock *ask = alg_sk(sk);
66 struct skcipher_ctx *ctx = ask->private;
67 struct skcipher_sg_list *sgl;
68 struct scatterlist *sg = NULL;
69
70 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
71 if (!list_empty(&ctx->tsgl))
72 sg = sgl->sg;
73
74 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
75 sgl = sock_kmalloc(sk, sizeof(*sgl) +
76 sizeof(sgl->sg[0]) * (MAX_SGL_ENTS + 1),
77 GFP_KERNEL);
78 if (!sgl)
79 return -ENOMEM;
80
81 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
82 sgl->cur = 0;
83
84 if (sg)
85 scatterwalk_sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
86
87 list_add_tail(&sgl->list, &ctx->tsgl);
88 }
89
90 return 0;
91}
92
93static void skcipher_pull_sgl(struct sock *sk, int used)
94{
95 struct alg_sock *ask = alg_sk(sk);
96 struct skcipher_ctx *ctx = ask->private;
97 struct skcipher_sg_list *sgl;
98 struct scatterlist *sg;
99 int i;
100
101 while (!list_empty(&ctx->tsgl)) {
102 sgl = list_first_entry(&ctx->tsgl, struct skcipher_sg_list,
103 list);
104 sg = sgl->sg;
105
106 for (i = 0; i < sgl->cur; i++) {
107 int plen = min_t(int, used, sg[i].length);
108
109 if (!sg_page(sg + i))
110 continue;
111
112 sg[i].length -= plen;
113 sg[i].offset += plen;
114
115 used -= plen;
116 ctx->used -= plen;
117
118 if (sg[i].length)
119 return;
120
121 put_page(sg_page(sg + i));
122 sg_assign_page(sg + i, NULL);
123 }
124
125 list_del(&sgl->list);
126 sock_kfree_s(sk, sgl,
127 sizeof(*sgl) + sizeof(sgl->sg[0]) *
128 (MAX_SGL_ENTS + 1));
129 }
130
131 if (!ctx->used)
132 ctx->merge = 0;
133}
134
135static void skcipher_free_sgl(struct sock *sk)
136{
137 struct alg_sock *ask = alg_sk(sk);
138 struct skcipher_ctx *ctx = ask->private;
139
140 skcipher_pull_sgl(sk, ctx->used);
141}
142
143static int skcipher_wait_for_wmem(struct sock *sk, unsigned flags)
144{
145 long timeout;
146 DEFINE_WAIT(wait);
147 int err = -ERESTARTSYS;
148
149 if (flags & MSG_DONTWAIT)
150 return -EAGAIN;
151
152 set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
153
154 for (;;) {
155 if (signal_pending(current))
156 break;
157 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
158 timeout = MAX_SCHEDULE_TIMEOUT;
159 if (sk_wait_event(sk, &timeout, skcipher_writable(sk))) {
160 err = 0;
161 break;
162 }
163 }
164 finish_wait(sk_sleep(sk), &wait);
165
166 return err;
167}
168
169static void skcipher_wmem_wakeup(struct sock *sk)
170{
171 struct socket_wq *wq;
172
173 if (!skcipher_writable(sk))
174 return;
175
176 rcu_read_lock();
177 wq = rcu_dereference(sk->sk_wq);
178 if (wq_has_sleeper(wq))
179 wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
180 POLLRDNORM |
181 POLLRDBAND);
182 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
183 rcu_read_unlock();
184}
185
186static int skcipher_wait_for_data(struct sock *sk, unsigned flags)
187{
188 struct alg_sock *ask = alg_sk(sk);
189 struct skcipher_ctx *ctx = ask->private;
190 long timeout;
191 DEFINE_WAIT(wait);
192 int err = -ERESTARTSYS;
193
194 if (flags & MSG_DONTWAIT) {
195 return -EAGAIN;
196 }
197
198 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
199
200 for (;;) {
201 if (signal_pending(current))
202 break;
203 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
204 timeout = MAX_SCHEDULE_TIMEOUT;
205 if (sk_wait_event(sk, &timeout, ctx->used)) {
206 err = 0;
207 break;
208 }
209 }
210 finish_wait(sk_sleep(sk), &wait);
211
212 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
213
214 return err;
215}
216
217static void skcipher_data_wakeup(struct sock *sk)
218{
219 struct alg_sock *ask = alg_sk(sk);
220 struct skcipher_ctx *ctx = ask->private;
221 struct socket_wq *wq;
222
223 if (!ctx->used)
224 return;
225
226 rcu_read_lock();
227 wq = rcu_dereference(sk->sk_wq);
228 if (wq_has_sleeper(wq))
229 wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
230 POLLRDNORM |
231 POLLRDBAND);
232 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
233 rcu_read_unlock();
234}
235
236static int skcipher_sendmsg(struct kiocb *unused, struct socket *sock,
237 struct msghdr *msg, size_t size)
238{
239 struct sock *sk = sock->sk;
240 struct alg_sock *ask = alg_sk(sk);
241 struct skcipher_ctx *ctx = ask->private;
242 struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(&ctx->req);
243 unsigned ivsize = crypto_ablkcipher_ivsize(tfm);
244 struct skcipher_sg_list *sgl;
245 struct af_alg_control con = {};
246 long copied = 0;
247 bool enc = 0;
248 int limit;
249 int err;
250 int i;
251
252 if (msg->msg_controllen) {
253 err = af_alg_cmsg_send(msg, &con);
254 if (err)
255 return err;
256
257 switch (con.op) {
258 case ALG_OP_ENCRYPT:
259 enc = 1;
260 break;
261 case ALG_OP_DECRYPT:
262 enc = 0;
263 break;
264 default:
265 return -EINVAL;
266 }
267
268 if (con.iv && con.iv->ivlen != ivsize)
269 return -EINVAL;
270 }
271
272 err = -EINVAL;
273
274 lock_sock(sk);
275 if (!ctx->more && ctx->used)
276 goto unlock;
277
278 if (!ctx->used) {
279 ctx->enc = enc;
280 if (con.iv)
281 memcpy(ctx->iv, con.iv->iv, ivsize);
282 }
283
284 limit = max_t(int, sk->sk_sndbuf, PAGE_SIZE);
285 limit -= ctx->used;
286
287 while (size) {
288 struct scatterlist *sg;
289 unsigned long len = size;
290 int plen;
291
292 if (ctx->merge) {
293 sgl = list_entry(ctx->tsgl.prev,
294 struct skcipher_sg_list, list);
295 sg = sgl->sg + sgl->cur - 1;
296 len = min_t(unsigned long, len,
297 PAGE_SIZE - sg->offset - sg->length);
298
299 err = memcpy_fromiovec(page_address(sg_page(sg)) +
300 sg->offset + sg->length,
301 msg->msg_iov, len);
302 if (err)
303 goto unlock;
304
305 sg->length += len;
306 ctx->merge = (sg->offset + sg->length) &
307 (PAGE_SIZE - 1);
308
309 ctx->used += len;
310 copied += len;
311 size -= len;
312 limit -= len;
313 continue;
314 }
315
316 if (limit < PAGE_SIZE) {
317 err = skcipher_wait_for_wmem(sk, msg->msg_flags);
318 if (err)
319 goto unlock;
320
321 limit = max_t(int, sk->sk_sndbuf, PAGE_SIZE);
322 limit -= ctx->used;
323 }
324
325 len = min_t(unsigned long, len, limit);
326
327 err = skcipher_alloc_sgl(sk);
328 if (err)
329 goto unlock;
330
331 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
332 sg = sgl->sg;
333 do {
334 i = sgl->cur;
335 plen = min_t(int, len, PAGE_SIZE);
336
337 sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
338 err = -ENOMEM;
339 if (!sg_page(sg + i))
340 goto unlock;
341
342 err = memcpy_fromiovec(page_address(sg_page(sg + i)),
343 msg->msg_iov, plen);
344 if (err) {
345 __free_page(sg_page(sg + i));
346 sg_assign_page(sg + i, NULL);
347 goto unlock;
348 }
349
350 sg[i].length = plen;
351 len -= plen;
352 ctx->used += plen;
353 copied += plen;
354 size -= plen;
355 limit -= plen;
356 sgl->cur++;
357 } while (len && sgl->cur < MAX_SGL_ENTS);
358
359 ctx->merge = plen & (PAGE_SIZE - 1);
360 }
361
362 err = 0;
363
364 ctx->more = msg->msg_flags & MSG_MORE;
365 if (!ctx->more && !list_empty(&ctx->tsgl))
366 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
367
368unlock:
369 skcipher_data_wakeup(sk);
370 release_sock(sk);
371
372 return copied ?: err;
373}
374
375static ssize_t skcipher_sendpage(struct socket *sock, struct page *page,
376 int offset, size_t size, int flags)
377{
378 struct sock *sk = sock->sk;
379 struct alg_sock *ask = alg_sk(sk);
380 struct skcipher_ctx *ctx = ask->private;
381 struct skcipher_sg_list *sgl;
382 int err = -EINVAL;
383 int limit;
384
385 lock_sock(sk);
386 if (!ctx->more && ctx->used)
387 goto unlock;
388
389 if (!size)
390 goto done;
391
392 limit = max_t(int, sk->sk_sndbuf, PAGE_SIZE);
393 limit -= ctx->used;
394
395 if (limit < PAGE_SIZE) {
396 err = skcipher_wait_for_wmem(sk, flags);
397 if (err)
398 goto unlock;
399
400 limit = max_t(int, sk->sk_sndbuf, PAGE_SIZE);
401 limit -= ctx->used;
402 }
403
404 err = skcipher_alloc_sgl(sk);
405 if (err)
406 goto unlock;
407
408 ctx->merge = 0;
409 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
410
411 get_page(page);
412 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
413 sgl->cur++;
414 ctx->used += size;
415
416done:
417 ctx->more = flags & MSG_MORE;
418 if (!ctx->more && !list_empty(&ctx->tsgl))
419 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
420
421unlock:
422 skcipher_data_wakeup(sk);
423 release_sock(sk);
424
425 return err ?: size;
426}
427
428static int skcipher_recvmsg(struct kiocb *unused, struct socket *sock,
429 struct msghdr *msg, size_t ignored, int flags)
430{
431 struct sock *sk = sock->sk;
432 struct alg_sock *ask = alg_sk(sk);
433 struct skcipher_ctx *ctx = ask->private;
434 unsigned bs = crypto_ablkcipher_blocksize(crypto_ablkcipher_reqtfm(
435 &ctx->req));
436 struct skcipher_sg_list *sgl;
437 struct scatterlist *sg;
438 unsigned long iovlen;
439 struct iovec *iov;
440 int err = -EAGAIN;
441 int used;
442 long copied = 0;
443
444 lock_sock(sk);
445 for (iov = msg->msg_iov, iovlen = msg->msg_iovlen; iovlen > 0;
446 iovlen--, iov++) {
447 unsigned long seglen = iov->iov_len;
448 char __user *from = iov->iov_base;
449
450 while (seglen) {
451 sgl = list_first_entry(&ctx->tsgl,
452 struct skcipher_sg_list, list);
453 sg = sgl->sg;
454
455 while (!sg->length)
456 sg++;
457
458 used = ctx->used;
459 if (!used) {
460 err = skcipher_wait_for_data(sk, flags);
461 if (err)
462 goto unlock;
463 }
464
465 used = min_t(unsigned long, used, seglen);
466
467 if (ctx->more || used < ctx->used)
468 used -= used % bs;
469
470 err = -EINVAL;
471 if (!used)
472 goto unlock;
473
474 used = af_alg_make_sg(&ctx->rsgl, from, used, 1);
475 if (used < 0)
476 goto unlock;
477
478 ablkcipher_request_set_crypt(&ctx->req, sg,
479 ctx->rsgl.sg, used,
480 ctx->iv);
481
482 err = af_alg_wait_for_completion(
483 ctx->enc ?
484 crypto_ablkcipher_encrypt(&ctx->req) :
485 crypto_ablkcipher_decrypt(&ctx->req),
486 &ctx->completion);
487
488 af_alg_free_sg(&ctx->rsgl);
489
490 if (err)
491 goto unlock;
492
493 copied += used;
494 from += used;
495 seglen -= used;
496 skcipher_pull_sgl(sk, used);
497 }
498 }
499
500 err = 0;
501
502unlock:
503 skcipher_wmem_wakeup(sk);
504 release_sock(sk);
505
506 return copied ?: err;
507}
508
509
510static unsigned int skcipher_poll(struct file *file, struct socket *sock,
511 poll_table *wait)
512{
513 struct sock *sk = sock->sk;
514 struct alg_sock *ask = alg_sk(sk);
515 struct skcipher_ctx *ctx = ask->private;
516 unsigned int mask;
517
518 sock_poll_wait(file, sk_sleep(sk), wait);
519 mask = 0;
520
521 if (ctx->used)
522 mask |= POLLIN | POLLRDNORM;
523
524 if (skcipher_writable(sk))
525 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
526
527 return mask;
528}
529
530static struct proto_ops algif_skcipher_ops = {
531 .family = PF_ALG,
532
533 .connect = sock_no_connect,
534 .socketpair = sock_no_socketpair,
535 .getname = sock_no_getname,
536 .ioctl = sock_no_ioctl,
537 .listen = sock_no_listen,
538 .shutdown = sock_no_shutdown,
539 .getsockopt = sock_no_getsockopt,
540 .mmap = sock_no_mmap,
541 .bind = sock_no_bind,
542 .accept = sock_no_accept,
543 .setsockopt = sock_no_setsockopt,
544
545 .release = af_alg_release,
546 .sendmsg = skcipher_sendmsg,
547 .sendpage = skcipher_sendpage,
548 .recvmsg = skcipher_recvmsg,
549 .poll = skcipher_poll,
550};
551
552static void *skcipher_bind(const char *name, u32 type, u32 mask)
553{
554 return crypto_alloc_ablkcipher(name, type, mask);
555}
556
557static void skcipher_release(void *private)
558{
559 crypto_free_ablkcipher(private);
560}
561
562static int skcipher_setkey(void *private, const u8 *key, unsigned int keylen)
563{
564 return crypto_ablkcipher_setkey(private, key, keylen);
565}
566
567static void skcipher_sock_destruct(struct sock *sk)
568{
569 struct alg_sock *ask = alg_sk(sk);
570 struct skcipher_ctx *ctx = ask->private;
571 struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(&ctx->req);
572
573 skcipher_free_sgl(sk);
574 sock_kfree_s(sk, ctx->iv, crypto_ablkcipher_ivsize(tfm));
575 sock_kfree_s(sk, ctx, ctx->len);
576 af_alg_release_parent(sk);
577}
578
579static int skcipher_accept_parent(void *private, struct sock *sk)
580{
581 struct skcipher_ctx *ctx;
582 struct alg_sock *ask = alg_sk(sk);
583 unsigned int len = sizeof(*ctx) + crypto_ablkcipher_reqsize(private);
584
585 ctx = sock_kmalloc(sk, len, GFP_KERNEL);
586 if (!ctx)
587 return -ENOMEM;
588
589 ctx->iv = sock_kmalloc(sk, crypto_ablkcipher_ivsize(private),
590 GFP_KERNEL);
591 if (!ctx->iv) {
592 sock_kfree_s(sk, ctx, len);
593 return -ENOMEM;
594 }
595
596 memset(ctx->iv, 0, crypto_ablkcipher_ivsize(private));
597
598 INIT_LIST_HEAD(&ctx->tsgl);
599 ctx->len = len;
600 ctx->used = 0;
601 ctx->more = 0;
602 ctx->merge = 0;
603 ctx->enc = 0;
604 af_alg_init_completion(&ctx->completion);
605
606 ask->private = ctx;
607
608 ablkcipher_request_set_tfm(&ctx->req, private);
609 ablkcipher_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
610 af_alg_complete, &ctx->completion);
611
612 sk->sk_destruct = skcipher_sock_destruct;
613
614 return 0;
615}
616
617static const struct af_alg_type algif_type_skcipher = {
618 .bind = skcipher_bind,
619 .release = skcipher_release,
620 .setkey = skcipher_setkey,
621 .accept = skcipher_accept_parent,
622 .ops = &algif_skcipher_ops,
623 .name = "skcipher",
624 .owner = THIS_MODULE
625};
626
627static int __init algif_skcipher_init(void)
628{
629 return af_alg_register_type(&algif_type_skcipher);
630}
631
632static void __exit algif_skcipher_exit(void)
633{
634 int err = af_alg_unregister_type(&algif_type_skcipher);
635 BUG_ON(err);
636}
637
638module_init(algif_skcipher_init);
639module_exit(algif_skcipher_exit);
640MODULE_LICENSE("GPL");
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-22 00:55:51 -0500