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15#include <crypto/hash.h>
16#include <crypto/if_alg.h>
17#include <linux/init.h>
18#include <linux/kernel.h>
19#include <linux/mm.h>
20#include <linux/module.h>
21#include <linux/net.h>
22#include <net/sock.h>
23
24struct hash_ctx {
25 struct af_alg_sgl sgl;
26
27 u8 *result;
28
29 struct af_alg_completion completion;
30
31 unsigned int len;
32 bool more;
33
34 struct ahash_request req;
35};
36
37struct algif_hash_tfm {
38 struct crypto_ahash *hash;
39 bool has_key;
40};
41
42static int hash_sendmsg(struct socket *sock, struct msghdr *msg,
43 size_t ignored)
44{
45 int limit = ALG_MAX_PAGES * PAGE_SIZE;
46 struct sock *sk = sock->sk;
47 struct alg_sock *ask = alg_sk(sk);
48 struct hash_ctx *ctx = ask->private;
49 long copied = 0;
50 int err;
51
52 if (limit > sk->sk_sndbuf)
53 limit = sk->sk_sndbuf;
54
55 lock_sock(sk);
56 if (!ctx->more) {
57 err = af_alg_wait_for_completion(crypto_ahash_init(&ctx->req),
58 &ctx->completion);
59 if (err)
60 goto unlock;
61 }
62
63 ctx->more = 0;
64
65 while (msg_data_left(msg)) {
66 int len = msg_data_left(msg);
67
68 if (len > limit)
69 len = limit;
70
71 len = af_alg_make_sg(&ctx->sgl, &msg->msg_iter, len);
72 if (len < 0) {
73 err = copied ? 0 : len;
74 goto unlock;
75 }
76
77 ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, NULL, len);
78
79 err = af_alg_wait_for_completion(crypto_ahash_update(&ctx->req),
80 &ctx->completion);
81 af_alg_free_sg(&ctx->sgl);
82 if (err)
83 goto unlock;
84
85 copied += len;
86 iov_iter_advance(&msg->msg_iter, len);
87 }
88
89 err = 0;
90
91 ctx->more = msg->msg_flags & MSG_MORE;
92 if (!ctx->more) {
93 ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0);
94 err = af_alg_wait_for_completion(crypto_ahash_final(&ctx->req),
95 &ctx->completion);
96 }
97
98unlock:
99 release_sock(sk);
100
101 return err ?: copied;
102}
103
104static ssize_t hash_sendpage(struct socket *sock, struct page *page,
105 int offset, size_t size, int flags)
106{
107 struct sock *sk = sock->sk;
108 struct alg_sock *ask = alg_sk(sk);
109 struct hash_ctx *ctx = ask->private;
110 int err;
111
112 if (flags & MSG_SENDPAGE_NOTLAST)
113 flags |= MSG_MORE;
114
115 lock_sock(sk);
116 sg_init_table(ctx->sgl.sg, 1);
117 sg_set_page(ctx->sgl.sg, page, size, offset);
118
119 ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, ctx->result, size);
120
121 if (!(flags & MSG_MORE)) {
122 if (ctx->more)
123 err = crypto_ahash_finup(&ctx->req);
124 else
125 err = crypto_ahash_digest(&ctx->req);
126 } else {
127 if (!ctx->more) {
128 err = crypto_ahash_init(&ctx->req);
129 err = af_alg_wait_for_completion(err, &ctx->completion);
130 if (err)
131 goto unlock;
132 }
133
134 err = crypto_ahash_update(&ctx->req);
135 }
136
137 err = af_alg_wait_for_completion(err, &ctx->completion);
138 if (err)
139 goto unlock;
140
141 ctx->more = flags & MSG_MORE;
142
143unlock:
144 release_sock(sk);
145
146 return err ?: size;
147}
148
149static int hash_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
150 int flags)
151{
152 struct sock *sk = sock->sk;
153 struct alg_sock *ask = alg_sk(sk);
154 struct hash_ctx *ctx = ask->private;
155 unsigned ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req));
156 int err;
157
158 if (len > ds)
159 len = ds;
160 else if (len < ds)
161 msg->msg_flags |= MSG_TRUNC;
162
163 lock_sock(sk);
164 if (ctx->more) {
165 ctx->more = 0;
166 ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0);
167 err = af_alg_wait_for_completion(crypto_ahash_final(&ctx->req),
168 &ctx->completion);
169 if (err)
170 goto unlock;
171 }
172
173 err = memcpy_to_msg(msg, ctx->result, len);
174
175unlock:
176 release_sock(sk);
177
178 return err ?: len;
179}
180
181static int hash_accept(struct socket *sock, struct socket *newsock, int flags)
182{
183 struct sock *sk = sock->sk;
184 struct alg_sock *ask = alg_sk(sk);
185 struct hash_ctx *ctx = ask->private;
186 struct ahash_request *req = &ctx->req;
187 char state[crypto_ahash_statesize(crypto_ahash_reqtfm(req))];
188 struct sock *sk2;
189 struct alg_sock *ask2;
190 struct hash_ctx *ctx2;
191 bool more;
192 int err;
193
194 lock_sock(sk);
195 more = ctx->more;
196 err = more ? crypto_ahash_export(req, state) : 0;
197 release_sock(sk);
198
199 if (err)
200 return err;
201
202 err = af_alg_accept(ask->parent, newsock);
203 if (err)
204 return err;
205
206 sk2 = newsock->sk;
207 ask2 = alg_sk(sk2);
208 ctx2 = ask2->private;
209 ctx2->more = more;
210
211 if (!more)
212 return err;
213
214 err = crypto_ahash_import(&ctx2->req, state);
215 if (err) {
216 sock_orphan(sk2);
217 sock_put(sk2);
218 }
219
220 return err;
221}
222
223static struct proto_ops algif_hash_ops = {
224 .family = PF_ALG,
225
226 .connect = sock_no_connect,
227 .socketpair = sock_no_socketpair,
228 .getname = sock_no_getname,
229 .ioctl = sock_no_ioctl,
230 .listen = sock_no_listen,
231 .shutdown = sock_no_shutdown,
232 .getsockopt = sock_no_getsockopt,
233 .mmap = sock_no_mmap,
234 .bind = sock_no_bind,
235 .setsockopt = sock_no_setsockopt,
236 .poll = sock_no_poll,
237
238 .release = af_alg_release,
239 .sendmsg = hash_sendmsg,
240 .sendpage = hash_sendpage,
241 .recvmsg = hash_recvmsg,
242 .accept = hash_accept,
243};
244
245static int hash_check_key(struct socket *sock)
246{
247 int err = 0;
248 struct sock *psk;
249 struct alg_sock *pask;
250 struct algif_hash_tfm *tfm;
251 struct sock *sk = sock->sk;
252 struct alg_sock *ask = alg_sk(sk);
253
254 lock_sock(sk);
255 if (ask->refcnt)
256 goto unlock_child;
257
258 psk = ask->parent;
259 pask = alg_sk(ask->parent);
260 tfm = pask->private;
261
262 err = -ENOKEY;
263 lock_sock_nested(psk, SINGLE_DEPTH_NESTING);
264 if (!tfm->has_key)
265 goto unlock;
266
267 if (!pask->refcnt++)
268 sock_hold(psk);
269
270 ask->refcnt = 1;
271 sock_put(psk);
272
273 err = 0;
274
275unlock:
276 release_sock(psk);
277unlock_child:
278 release_sock(sk);
279
280 return err;
281}
282
283static int hash_sendmsg_nokey(struct socket *sock, struct msghdr *msg,
284 size_t size)
285{
286 int err;
287
288 err = hash_check_key(sock);
289 if (err)
290 return err;
291
292 return hash_sendmsg(sock, msg, size);
293}
294
295static ssize_t hash_sendpage_nokey(struct socket *sock, struct page *page,
296 int offset, size_t size, int flags)
297{
298 int err;
299
300 err = hash_check_key(sock);
301 if (err)
302 return err;
303
304 return hash_sendpage(sock, page, offset, size, flags);
305}
306
307static int hash_recvmsg_nokey(struct socket *sock, struct msghdr *msg,
308 size_t ignored, int flags)
309{
310 int err;
311
312 err = hash_check_key(sock);
313 if (err)
314 return err;
315
316 return hash_recvmsg(sock, msg, ignored, flags);
317}
318
319static int hash_accept_nokey(struct socket *sock, struct socket *newsock,
320 int flags)
321{
322 int err;
323
324 err = hash_check_key(sock);
325 if (err)
326 return err;
327
328 return hash_accept(sock, newsock, flags);
329}
330
331static struct proto_ops algif_hash_ops_nokey = {
332 .family = PF_ALG,
333
334 .connect = sock_no_connect,
335 .socketpair = sock_no_socketpair,
336 .getname = sock_no_getname,
337 .ioctl = sock_no_ioctl,
338 .listen = sock_no_listen,
339 .shutdown = sock_no_shutdown,
340 .getsockopt = sock_no_getsockopt,
341 .mmap = sock_no_mmap,
342 .bind = sock_no_bind,
343 .setsockopt = sock_no_setsockopt,
344 .poll = sock_no_poll,
345
346 .release = af_alg_release,
347 .sendmsg = hash_sendmsg_nokey,
348 .sendpage = hash_sendpage_nokey,
349 .recvmsg = hash_recvmsg_nokey,
350 .accept = hash_accept_nokey,
351};
352
353static void *hash_bind(const char *name, u32 type, u32 mask)
354{
355 struct algif_hash_tfm *tfm;
356 struct crypto_ahash *hash;
357
358 tfm = kzalloc(sizeof(*tfm), GFP_KERNEL);
359 if (!tfm)
360 return ERR_PTR(-ENOMEM);
361
362 hash = crypto_alloc_ahash(name, type, mask);
363 if (IS_ERR(hash)) {
364 kfree(tfm);
365 return ERR_CAST(hash);
366 }
367
368 tfm->hash = hash;
369
370 return tfm;
371}
372
373static void hash_release(void *private)
374{
375 struct algif_hash_tfm *tfm = private;
376
377 crypto_free_ahash(tfm->hash);
378 kfree(tfm);
379}
380
381static int hash_setkey(void *private, const u8 *key, unsigned int keylen)
382{
383 struct algif_hash_tfm *tfm = private;
384 int err;
385
386 err = crypto_ahash_setkey(tfm->hash, key, keylen);
387 tfm->has_key = !err;
388
389 return err;
390}
391
392static void hash_sock_destruct(struct sock *sk)
393{
394 struct alg_sock *ask = alg_sk(sk);
395 struct hash_ctx *ctx = ask->private;
396
397 sock_kzfree_s(sk, ctx->result,
398 crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req)));
399 sock_kfree_s(sk, ctx, ctx->len);
400 af_alg_release_parent(sk);
401}
402
403static int hash_accept_parent_nokey(void *private, struct sock *sk)
404{
405 struct hash_ctx *ctx;
406 struct alg_sock *ask = alg_sk(sk);
407 struct algif_hash_tfm *tfm = private;
408 struct crypto_ahash *hash = tfm->hash;
409 unsigned len = sizeof(*ctx) + crypto_ahash_reqsize(hash);
410 unsigned ds = crypto_ahash_digestsize(hash);
411
412 ctx = sock_kmalloc(sk, len, GFP_KERNEL);
413 if (!ctx)
414 return -ENOMEM;
415
416 ctx->result = sock_kmalloc(sk, ds, GFP_KERNEL);
417 if (!ctx->result) {
418 sock_kfree_s(sk, ctx, len);
419 return -ENOMEM;
420 }
421
422 memset(ctx->result, 0, ds);
423
424 ctx->len = len;
425 ctx->more = 0;
426 af_alg_init_completion(&ctx->completion);
427
428 ask->private = ctx;
429
430 ahash_request_set_tfm(&ctx->req, hash);
431 ahash_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
432 af_alg_complete, &ctx->completion);
433
434 sk->sk_destruct = hash_sock_destruct;
435
436 return 0;
437}
438
439static int hash_accept_parent(void *private, struct sock *sk)
440{
441 struct algif_hash_tfm *tfm = private;
442
443 if (!tfm->has_key && crypto_ahash_has_setkey(tfm->hash))
444 return -ENOKEY;
445
446 return hash_accept_parent_nokey(private, sk);
447}
448
449static const struct af_alg_type algif_type_hash = {
450 .bind = hash_bind,
451 .release = hash_release,
452 .setkey = hash_setkey,
453 .accept = hash_accept_parent,
454 .accept_nokey = hash_accept_parent_nokey,
455 .ops = &algif_hash_ops,
456 .ops_nokey = &algif_hash_ops_nokey,
457 .name = "hash",
458 .owner = THIS_MODULE
459};
460
461static int __init algif_hash_init(void)
462{
463 return af_alg_register_type(&algif_type_hash);
464}
465
466static void __exit algif_hash_exit(void)
467{
468 int err = af_alg_unregister_type(&algif_type_hash);
469 BUG_ON(err);
470}
471
472module_init(algif_hash_init);
473module_exit(algif_hash_exit);
474MODULE_LICENSE("GPL");
475
