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1 | /* |
2 | * algif_hash: User-space interface for hash algorithms | |
3 | * | |
4 | * This file provides the user-space API for hash 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 <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 | ||
24 | struct 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 | ||
37 | static int hash_sendmsg(struct kiocb *unused, struct socket *sock, | |
38 | struct msghdr *msg, size_t ignored) | |
39 | { | |
40 | int limit = ALG_MAX_PAGES * PAGE_SIZE; | |
41 | struct sock *sk = sock->sk; | |
42 | struct alg_sock *ask = alg_sk(sk); | |
43 | struct hash_ctx *ctx = ask->private; | |
44 | unsigned long iovlen; | |
45 | struct iovec *iov; | |
46 | long copied = 0; | |
47 | int err; | |
48 | ||
49 | if (limit > sk->sk_sndbuf) | |
50 | limit = sk->sk_sndbuf; | |
51 | ||
52 | lock_sock(sk); | |
53 | if (!ctx->more) { | |
54 | err = crypto_ahash_init(&ctx->req); | |
55 | if (err) | |
56 | goto unlock; | |
57 | } | |
58 | ||
59 | ctx->more = 0; | |
60 | ||
61 | for (iov = msg->msg_iov, iovlen = msg->msg_iovlen; iovlen > 0; | |
62 | iovlen--, iov++) { | |
63 | unsigned long seglen = iov->iov_len; | |
64 | char __user *from = iov->iov_base; | |
65 | ||
66 | while (seglen) { | |
67 | int len = min_t(unsigned long, seglen, limit); | |
68 | int newlen; | |
69 | ||
70 | newlen = af_alg_make_sg(&ctx->sgl, from, len, 0); | |
71 | if (newlen < 0) | |
72 | goto unlock; | |
73 | ||
74 | ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, NULL, | |
75 | newlen); | |
76 | ||
77 | err = af_alg_wait_for_completion( | |
78 | crypto_ahash_update(&ctx->req), | |
79 | &ctx->completion); | |
80 | ||
81 | af_alg_free_sg(&ctx->sgl); | |
82 | ||
83 | if (err) | |
84 | goto unlock; | |
85 | ||
86 | seglen -= newlen; | |
87 | from += newlen; | |
88 | copied += newlen; | |
89 | } | |
90 | } | |
91 | ||
92 | err = 0; | |
93 | ||
94 | ctx->more = msg->msg_flags & MSG_MORE; | |
95 | if (!ctx->more) { | |
96 | ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0); | |
97 | err = af_alg_wait_for_completion(crypto_ahash_final(&ctx->req), | |
98 | &ctx->completion); | |
99 | } | |
100 | ||
101 | unlock: | |
102 | release_sock(sk); | |
103 | ||
104 | return err ?: copied; | |
105 | } | |
106 | ||
107 | static ssize_t hash_sendpage(struct socket *sock, struct page *page, | |
108 | int offset, size_t size, int flags) | |
109 | { | |
110 | struct sock *sk = sock->sk; | |
111 | struct alg_sock *ask = alg_sk(sk); | |
112 | struct hash_ctx *ctx = ask->private; | |
113 | int err; | |
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 | if (err) | |
130 | goto unlock; | |
131 | } | |
132 | ||
133 | err = crypto_ahash_update(&ctx->req); | |
134 | } | |
135 | ||
136 | err = af_alg_wait_for_completion(err, &ctx->completion); | |
137 | if (err) | |
138 | goto unlock; | |
139 | ||
140 | ctx->more = flags & MSG_MORE; | |
141 | ||
142 | unlock: | |
143 | release_sock(sk); | |
144 | ||
145 | return err ?: size; | |
146 | } | |
147 | ||
148 | static int hash_recvmsg(struct kiocb *unused, struct socket *sock, | |
149 | struct msghdr *msg, size_t len, int flags) | |
150 | { | |
151 | struct sock *sk = sock->sk; | |
152 | struct alg_sock *ask = alg_sk(sk); | |
153 | struct hash_ctx *ctx = ask->private; | |
154 | unsigned ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req)); | |
155 | int err; | |
156 | ||
157 | if (len > ds) | |
158 | len = ds; | |
159 | else if (len < ds) | |
160 | msg->msg_flags |= MSG_TRUNC; | |
161 | ||
162 | lock_sock(sk); | |
163 | if (ctx->more) { | |
164 | ctx->more = 0; | |
165 | ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0); | |
166 | err = af_alg_wait_for_completion(crypto_ahash_final(&ctx->req), | |
167 | &ctx->completion); | |
168 | if (err) | |
169 | goto unlock; | |
170 | } | |
171 | ||
172 | err = memcpy_toiovec(msg->msg_iov, ctx->result, len); | |
173 | ||
174 | unlock: | |
175 | release_sock(sk); | |
176 | ||
177 | return err ?: len; | |
178 | } | |
179 | ||
180 | static int hash_accept(struct socket *sock, struct socket *newsock, int flags) | |
181 | { | |
182 | struct sock *sk = sock->sk; | |
183 | struct alg_sock *ask = alg_sk(sk); | |
184 | struct hash_ctx *ctx = ask->private; | |
185 | struct ahash_request *req = &ctx->req; | |
186 | char state[crypto_ahash_statesize(crypto_ahash_reqtfm(req))]; | |
187 | struct sock *sk2; | |
188 | struct alg_sock *ask2; | |
189 | struct hash_ctx *ctx2; | |
190 | int err; | |
191 | ||
192 | err = crypto_ahash_export(req, state); | |
193 | if (err) | |
194 | return err; | |
195 | ||
196 | err = af_alg_accept(ask->parent, newsock); | |
197 | if (err) | |
198 | return err; | |
199 | ||
200 | sk2 = newsock->sk; | |
201 | ask2 = alg_sk(sk2); | |
202 | ctx2 = ask2->private; | |
203 | ctx2->more = 1; | |
204 | ||
205 | err = crypto_ahash_import(&ctx2->req, state); | |
206 | if (err) { | |
207 | sock_orphan(sk2); | |
208 | sock_put(sk2); | |
209 | } | |
210 | ||
211 | return err; | |
212 | } | |
213 | ||
214 | static struct proto_ops algif_hash_ops = { | |
215 | .family = PF_ALG, | |
216 | ||
217 | .connect = sock_no_connect, | |
218 | .socketpair = sock_no_socketpair, | |
219 | .getname = sock_no_getname, | |
220 | .ioctl = sock_no_ioctl, | |
221 | .listen = sock_no_listen, | |
222 | .shutdown = sock_no_shutdown, | |
223 | .getsockopt = sock_no_getsockopt, | |
224 | .mmap = sock_no_mmap, | |
225 | .bind = sock_no_bind, | |
226 | .setsockopt = sock_no_setsockopt, | |
227 | .poll = sock_no_poll, | |
228 | ||
229 | .release = af_alg_release, | |
230 | .sendmsg = hash_sendmsg, | |
231 | .sendpage = hash_sendpage, | |
232 | .recvmsg = hash_recvmsg, | |
233 | .accept = hash_accept, | |
234 | }; | |
235 | ||
236 | static void *hash_bind(const char *name, u32 type, u32 mask) | |
237 | { | |
238 | return crypto_alloc_ahash(name, type, mask); | |
239 | } | |
240 | ||
241 | static void hash_release(void *private) | |
242 | { | |
243 | crypto_free_ahash(private); | |
244 | } | |
245 | ||
246 | static int hash_setkey(void *private, const u8 *key, unsigned int keylen) | |
247 | { | |
248 | return crypto_ahash_setkey(private, key, keylen); | |
249 | } | |
250 | ||
251 | static void hash_sock_destruct(struct sock *sk) | |
252 | { | |
253 | struct alg_sock *ask = alg_sk(sk); | |
254 | struct hash_ctx *ctx = ask->private; | |
255 | ||
256 | sock_kfree_s(sk, ctx->result, | |
257 | crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req))); | |
258 | sock_kfree_s(sk, ctx, ctx->len); | |
259 | af_alg_release_parent(sk); | |
260 | } | |
261 | ||
262 | static int hash_accept_parent(void *private, struct sock *sk) | |
263 | { | |
264 | struct hash_ctx *ctx; | |
265 | struct alg_sock *ask = alg_sk(sk); | |
266 | unsigned len = sizeof(*ctx) + crypto_ahash_reqsize(private); | |
267 | unsigned ds = crypto_ahash_digestsize(private); | |
268 | ||
269 | ctx = sock_kmalloc(sk, len, GFP_KERNEL); | |
270 | if (!ctx) | |
271 | return -ENOMEM; | |
272 | ||
273 | ctx->result = sock_kmalloc(sk, ds, GFP_KERNEL); | |
274 | if (!ctx->result) { | |
275 | sock_kfree_s(sk, ctx, len); | |
276 | return -ENOMEM; | |
277 | } | |
278 | ||
279 | memset(ctx->result, 0, ds); | |
280 | ||
281 | ctx->len = len; | |
282 | ctx->more = 0; | |
283 | af_alg_init_completion(&ctx->completion); | |
284 | ||
285 | ask->private = ctx; | |
286 | ||
287 | ahash_request_set_tfm(&ctx->req, private); | |
288 | ahash_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG, | |
289 | af_alg_complete, &ctx->completion); | |
290 | ||
291 | sk->sk_destruct = hash_sock_destruct; | |
292 | ||
293 | return 0; | |
294 | } | |
295 | ||
296 | static const struct af_alg_type algif_type_hash = { | |
297 | .bind = hash_bind, | |
298 | .release = hash_release, | |
299 | .setkey = hash_setkey, | |
300 | .accept = hash_accept_parent, | |
301 | .ops = &algif_hash_ops, | |
302 | .name = "hash", | |
303 | .owner = THIS_MODULE | |
304 | }; | |
305 | ||
306 | static int __init algif_hash_init(void) | |
307 | { | |
308 | return af_alg_register_type(&algif_type_hash); | |
309 | } | |
310 | ||
311 | static void __exit algif_hash_exit(void) | |
312 | { | |
313 | int err = af_alg_unregister_type(&algif_type_hash); | |
314 | BUG_ON(err); | |
315 | } | |
316 | ||
317 | module_init(algif_hash_init); | |
318 | module_exit(algif_hash_exit); | |
319 | MODULE_LICENSE("GPL"); |