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fe869cdb HX |
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); | |
269230e7 HX |
71 | if (newlen < 0) { |
72 | err = copied ? 0 : newlen; | |
fe869cdb | 73 | goto unlock; |
269230e7 | 74 | } |
fe869cdb HX |
75 | |
76 | ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, NULL, | |
77 | newlen); | |
78 | ||
79 | err = af_alg_wait_for_completion( | |
80 | crypto_ahash_update(&ctx->req), | |
81 | &ctx->completion); | |
82 | ||
83 | af_alg_free_sg(&ctx->sgl); | |
84 | ||
85 | if (err) | |
86 | goto unlock; | |
87 | ||
88 | seglen -= newlen; | |
89 | from += newlen; | |
90 | copied += newlen; | |
91 | } | |
92 | } | |
93 | ||
94 | err = 0; | |
95 | ||
96 | ctx->more = msg->msg_flags & MSG_MORE; | |
97 | if (!ctx->more) { | |
98 | ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0); | |
99 | err = af_alg_wait_for_completion(crypto_ahash_final(&ctx->req), | |
100 | &ctx->completion); | |
101 | } | |
102 | ||
103 | unlock: | |
104 | release_sock(sk); | |
105 | ||
106 | return err ?: copied; | |
107 | } | |
108 | ||
109 | static ssize_t hash_sendpage(struct socket *sock, struct page *page, | |
110 | int offset, size_t size, int flags) | |
111 | { | |
112 | struct sock *sk = sock->sk; | |
113 | struct alg_sock *ask = alg_sk(sk); | |
114 | struct hash_ctx *ctx = ask->private; | |
115 | int err; | |
116 | ||
117 | lock_sock(sk); | |
118 | sg_init_table(ctx->sgl.sg, 1); | |
119 | sg_set_page(ctx->sgl.sg, page, size, offset); | |
120 | ||
121 | ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, ctx->result, size); | |
122 | ||
123 | if (!(flags & MSG_MORE)) { | |
124 | if (ctx->more) | |
125 | err = crypto_ahash_finup(&ctx->req); | |
126 | else | |
127 | err = crypto_ahash_digest(&ctx->req); | |
128 | } else { | |
129 | if (!ctx->more) { | |
130 | err = crypto_ahash_init(&ctx->req); | |
131 | if (err) | |
132 | goto unlock; | |
133 | } | |
134 | ||
135 | err = crypto_ahash_update(&ctx->req); | |
136 | } | |
137 | ||
138 | err = af_alg_wait_for_completion(err, &ctx->completion); | |
139 | if (err) | |
140 | goto unlock; | |
141 | ||
142 | ctx->more = flags & MSG_MORE; | |
143 | ||
144 | unlock: | |
145 | release_sock(sk); | |
146 | ||
147 | return err ?: size; | |
148 | } | |
149 | ||
150 | static int hash_recvmsg(struct kiocb *unused, struct socket *sock, | |
151 | struct msghdr *msg, size_t len, int flags) | |
152 | { | |
153 | struct sock *sk = sock->sk; | |
154 | struct alg_sock *ask = alg_sk(sk); | |
155 | struct hash_ctx *ctx = ask->private; | |
156 | unsigned ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req)); | |
157 | int err; | |
158 | ||
159 | if (len > ds) | |
160 | len = ds; | |
161 | else if (len < ds) | |
162 | msg->msg_flags |= MSG_TRUNC; | |
163 | ||
72a763d8 MK |
164 | msg->msg_namelen = 0; |
165 | ||
fe869cdb HX |
166 | lock_sock(sk); |
167 | if (ctx->more) { | |
168 | ctx->more = 0; | |
169 | ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0); | |
170 | err = af_alg_wait_for_completion(crypto_ahash_final(&ctx->req), | |
171 | &ctx->completion); | |
172 | if (err) | |
173 | goto unlock; | |
174 | } | |
175 | ||
176 | err = memcpy_toiovec(msg->msg_iov, ctx->result, len); | |
177 | ||
178 | unlock: | |
179 | release_sock(sk); | |
180 | ||
181 | return err ?: len; | |
182 | } | |
183 | ||
184 | static int hash_accept(struct socket *sock, struct socket *newsock, int flags) | |
185 | { | |
186 | struct sock *sk = sock->sk; | |
187 | struct alg_sock *ask = alg_sk(sk); | |
188 | struct hash_ctx *ctx = ask->private; | |
189 | struct ahash_request *req = &ctx->req; | |
190 | char state[crypto_ahash_statesize(crypto_ahash_reqtfm(req))]; | |
191 | struct sock *sk2; | |
192 | struct alg_sock *ask2; | |
193 | struct hash_ctx *ctx2; | |
194 | int err; | |
195 | ||
196 | err = crypto_ahash_export(req, state); | |
197 | if (err) | |
198 | return err; | |
199 | ||
200 | err = af_alg_accept(ask->parent, newsock); | |
201 | if (err) | |
202 | return err; | |
203 | ||
204 | sk2 = newsock->sk; | |
205 | ask2 = alg_sk(sk2); | |
206 | ctx2 = ask2->private; | |
207 | ctx2->more = 1; | |
208 | ||
209 | err = crypto_ahash_import(&ctx2->req, state); | |
210 | if (err) { | |
211 | sock_orphan(sk2); | |
212 | sock_put(sk2); | |
213 | } | |
214 | ||
215 | return err; | |
216 | } | |
217 | ||
218 | static struct proto_ops algif_hash_ops = { | |
219 | .family = PF_ALG, | |
220 | ||
221 | .connect = sock_no_connect, | |
222 | .socketpair = sock_no_socketpair, | |
223 | .getname = sock_no_getname, | |
224 | .ioctl = sock_no_ioctl, | |
225 | .listen = sock_no_listen, | |
226 | .shutdown = sock_no_shutdown, | |
227 | .getsockopt = sock_no_getsockopt, | |
228 | .mmap = sock_no_mmap, | |
229 | .bind = sock_no_bind, | |
230 | .setsockopt = sock_no_setsockopt, | |
231 | .poll = sock_no_poll, | |
232 | ||
233 | .release = af_alg_release, | |
234 | .sendmsg = hash_sendmsg, | |
235 | .sendpage = hash_sendpage, | |
236 | .recvmsg = hash_recvmsg, | |
237 | .accept = hash_accept, | |
238 | }; | |
239 | ||
240 | static void *hash_bind(const char *name, u32 type, u32 mask) | |
241 | { | |
242 | return crypto_alloc_ahash(name, type, mask); | |
243 | } | |
244 | ||
245 | static void hash_release(void *private) | |
246 | { | |
247 | crypto_free_ahash(private); | |
248 | } | |
249 | ||
250 | static int hash_setkey(void *private, const u8 *key, unsigned int keylen) | |
251 | { | |
252 | return crypto_ahash_setkey(private, key, keylen); | |
253 | } | |
254 | ||
255 | static void hash_sock_destruct(struct sock *sk) | |
256 | { | |
257 | struct alg_sock *ask = alg_sk(sk); | |
258 | struct hash_ctx *ctx = ask->private; | |
259 | ||
260 | sock_kfree_s(sk, ctx->result, | |
261 | crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req))); | |
262 | sock_kfree_s(sk, ctx, ctx->len); | |
263 | af_alg_release_parent(sk); | |
264 | } | |
265 | ||
266 | static int hash_accept_parent(void *private, struct sock *sk) | |
267 | { | |
268 | struct hash_ctx *ctx; | |
269 | struct alg_sock *ask = alg_sk(sk); | |
270 | unsigned len = sizeof(*ctx) + crypto_ahash_reqsize(private); | |
271 | unsigned ds = crypto_ahash_digestsize(private); | |
272 | ||
273 | ctx = sock_kmalloc(sk, len, GFP_KERNEL); | |
274 | if (!ctx) | |
275 | return -ENOMEM; | |
276 | ||
277 | ctx->result = sock_kmalloc(sk, ds, GFP_KERNEL); | |
278 | if (!ctx->result) { | |
279 | sock_kfree_s(sk, ctx, len); | |
280 | return -ENOMEM; | |
281 | } | |
282 | ||
283 | memset(ctx->result, 0, ds); | |
284 | ||
285 | ctx->len = len; | |
286 | ctx->more = 0; | |
287 | af_alg_init_completion(&ctx->completion); | |
288 | ||
289 | ask->private = ctx; | |
290 | ||
291 | ahash_request_set_tfm(&ctx->req, private); | |
292 | ahash_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG, | |
293 | af_alg_complete, &ctx->completion); | |
294 | ||
295 | sk->sk_destruct = hash_sock_destruct; | |
296 | ||
297 | return 0; | |
298 | } | |
299 | ||
300 | static const struct af_alg_type algif_type_hash = { | |
301 | .bind = hash_bind, | |
302 | .release = hash_release, | |
303 | .setkey = hash_setkey, | |
304 | .accept = hash_accept_parent, | |
305 | .ops = &algif_hash_ops, | |
306 | .name = "hash", | |
307 | .owner = THIS_MODULE | |
308 | }; | |
309 | ||
310 | static int __init algif_hash_init(void) | |
311 | { | |
312 | return af_alg_register_type(&algif_type_hash); | |
313 | } | |
314 | ||
315 | static void __exit algif_hash_exit(void) | |
316 | { | |
317 | int err = af_alg_unregister_type(&algif_type_hash); | |
318 | BUG_ON(err); | |
319 | } | |
320 | ||
321 | module_init(algif_hash_init); | |
322 | module_exit(algif_hash_exit); | |
323 | MODULE_LICENSE("GPL"); |