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1 | /* | |
2 | * if_alg: User-space algorithm interface | |
3 | * | |
4 | * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify it | |
7 | * under the terms of the GNU General Public License as published by the Free | |
8 | * Software Foundation; either version 2 of the License, or (at your option) | |
9 | * any later version. | |
10 | * | |
11 | */ | |
12 | ||
13 | #ifndef _CRYPTO_IF_ALG_H | |
14 | #define _CRYPTO_IF_ALG_H | |
15 | ||
16 | #include <linux/compiler.h> | |
17 | #include <linux/completion.h> | |
18 | #include <linux/if_alg.h> | |
19 | #include <linux/scatterlist.h> | |
20 | #include <linux/types.h> | |
21 | #include <linux/atomic.h> | |
22 | #include <net/sock.h> | |
23 | ||
24 | #include <crypto/aead.h> | |
25 | #include <crypto/skcipher.h> | |
26 | ||
27 | #define ALG_MAX_PAGES 16 | |
28 | ||
29 | struct crypto_async_request; | |
30 | ||
31 | struct alg_sock { | |
32 | /* struct sock must be the first member of struct alg_sock */ | |
33 | struct sock sk; | |
34 | ||
35 | struct sock *parent; | |
36 | ||
37 | unsigned int refcnt; | |
38 | unsigned int nokey_refcnt; | |
39 | ||
40 | const struct af_alg_type *type; | |
41 | void *private; | |
42 | }; | |
43 | ||
44 | struct af_alg_control { | |
45 | struct af_alg_iv *iv; | |
46 | int op; | |
47 | unsigned int aead_assoclen; | |
48 | }; | |
49 | ||
50 | struct af_alg_type { | |
51 | void *(*bind)(const char *name, u32 type, u32 mask); | |
52 | void (*release)(void *private); | |
53 | int (*setkey)(void *private, const u8 *key, unsigned int keylen); | |
54 | int (*accept)(void *private, struct sock *sk); | |
55 | int (*accept_nokey)(void *private, struct sock *sk); | |
56 | int (*setauthsize)(void *private, unsigned int authsize); | |
57 | ||
58 | struct proto_ops *ops; | |
59 | struct proto_ops *ops_nokey; | |
60 | struct module *owner; | |
61 | char name[14]; | |
62 | }; | |
63 | ||
64 | struct af_alg_sgl { | |
65 | struct scatterlist sg[ALG_MAX_PAGES + 1]; | |
66 | struct page *pages[ALG_MAX_PAGES]; | |
67 | unsigned int npages; | |
68 | }; | |
69 | ||
70 | /* TX SGL entry */ | |
71 | struct af_alg_tsgl { | |
72 | struct list_head list; | |
73 | unsigned int cur; /* Last processed SG entry */ | |
74 | struct scatterlist sg[0]; /* Array of SGs forming the SGL */ | |
75 | }; | |
76 | ||
77 | #define MAX_SGL_ENTS ((4096 - sizeof(struct af_alg_tsgl)) / \ | |
78 | sizeof(struct scatterlist) - 1) | |
79 | ||
80 | /* RX SGL entry */ | |
81 | struct af_alg_rsgl { | |
82 | struct af_alg_sgl sgl; | |
83 | struct list_head list; | |
84 | size_t sg_num_bytes; /* Bytes of data in that SGL */ | |
85 | }; | |
86 | ||
87 | /** | |
88 | * struct af_alg_async_req - definition of crypto request | |
89 | * @iocb: IOCB for AIO operations | |
90 | * @sk: Socket the request is associated with | |
91 | * @first_rsgl: First RX SG | |
92 | * @last_rsgl: Pointer to last RX SG | |
93 | * @rsgl_list: Track RX SGs | |
94 | * @tsgl: Private, per request TX SGL of buffers to process | |
95 | * @tsgl_entries: Number of entries in priv. TX SGL | |
96 | * @outlen: Number of output bytes generated by crypto op | |
97 | * @areqlen: Length of this data structure | |
98 | * @cra_u: Cipher request | |
99 | */ | |
100 | struct af_alg_async_req { | |
101 | struct kiocb *iocb; | |
102 | struct sock *sk; | |
103 | ||
104 | struct af_alg_rsgl first_rsgl; | |
105 | struct af_alg_rsgl *last_rsgl; | |
106 | struct list_head rsgl_list; | |
107 | ||
108 | struct scatterlist *tsgl; | |
109 | unsigned int tsgl_entries; | |
110 | ||
111 | unsigned int outlen; | |
112 | unsigned int areqlen; | |
113 | ||
114 | union { | |
115 | struct aead_request aead_req; | |
116 | struct skcipher_request skcipher_req; | |
117 | } cra_u; | |
118 | ||
119 | /* req ctx trails this struct */ | |
120 | }; | |
121 | ||
122 | /** | |
123 | * struct af_alg_ctx - definition of the crypto context | |
124 | * | |
125 | * The crypto context tracks the input data during the lifetime of an AF_ALG | |
126 | * socket. | |
127 | * | |
128 | * @tsgl_list: Link to TX SGL | |
129 | * @iv: IV for cipher operation | |
130 | * @aead_assoclen: Length of AAD for AEAD cipher operations | |
131 | * @completion: Work queue for synchronous operation | |
132 | * @used: TX bytes sent to kernel. This variable is used to | |
133 | * ensure that user space cannot cause the kernel | |
134 | * to allocate too much memory in sendmsg operation. | |
135 | * @rcvused: Total RX bytes to be filled by kernel. This variable | |
136 | * is used to ensure user space cannot cause the kernel | |
137 | * to allocate too much memory in a recvmsg operation. | |
138 | * @more: More data to be expected from user space? | |
139 | * @merge: Shall new data from user space be merged into existing | |
140 | * SG? | |
141 | * @enc: Cryptographic operation to be performed when | |
142 | * recvmsg is invoked. | |
143 | * @len: Length of memory allocated for this data structure. | |
144 | */ | |
145 | struct af_alg_ctx { | |
146 | struct list_head tsgl_list; | |
147 | ||
148 | void *iv; | |
149 | size_t aead_assoclen; | |
150 | ||
151 | struct crypto_wait wait; | |
152 | ||
153 | size_t used; | |
154 | atomic_t rcvused; | |
155 | ||
156 | bool more; | |
157 | bool merge; | |
158 | bool enc; | |
159 | ||
160 | unsigned int len; | |
161 | }; | |
162 | ||
163 | int af_alg_register_type(const struct af_alg_type *type); | |
164 | int af_alg_unregister_type(const struct af_alg_type *type); | |
165 | ||
166 | int af_alg_release(struct socket *sock); | |
167 | void af_alg_release_parent(struct sock *sk); | |
168 | int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern); | |
169 | ||
170 | int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len); | |
171 | void af_alg_free_sg(struct af_alg_sgl *sgl); | |
172 | void af_alg_link_sg(struct af_alg_sgl *sgl_prev, struct af_alg_sgl *sgl_new); | |
173 | ||
174 | int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con); | |
175 | ||
176 | static inline struct alg_sock *alg_sk(struct sock *sk) | |
177 | { | |
178 | return (struct alg_sock *)sk; | |
179 | } | |
180 | ||
181 | /** | |
182 | * Size of available buffer for sending data from user space to kernel. | |
183 | * | |
184 | * @sk socket of connection to user space | |
185 | * @return number of bytes still available | |
186 | */ | |
187 | static inline int af_alg_sndbuf(struct sock *sk) | |
188 | { | |
189 | struct alg_sock *ask = alg_sk(sk); | |
190 | struct af_alg_ctx *ctx = ask->private; | |
191 | ||
192 | return max_t(int, max_t(int, sk->sk_sndbuf & PAGE_MASK, PAGE_SIZE) - | |
193 | ctx->used, 0); | |
194 | } | |
195 | ||
196 | /** | |
197 | * Can the send buffer still be written to? | |
198 | * | |
199 | * @sk socket of connection to user space | |
200 | * @return true => writable, false => not writable | |
201 | */ | |
202 | static inline bool af_alg_writable(struct sock *sk) | |
203 | { | |
204 | return PAGE_SIZE <= af_alg_sndbuf(sk); | |
205 | } | |
206 | ||
207 | /** | |
208 | * Size of available buffer used by kernel for the RX user space operation. | |
209 | * | |
210 | * @sk socket of connection to user space | |
211 | * @return number of bytes still available | |
212 | */ | |
213 | static inline int af_alg_rcvbuf(struct sock *sk) | |
214 | { | |
215 | struct alg_sock *ask = alg_sk(sk); | |
216 | struct af_alg_ctx *ctx = ask->private; | |
217 | ||
218 | return max_t(int, max_t(int, sk->sk_rcvbuf & PAGE_MASK, PAGE_SIZE) - | |
219 | atomic_read(&ctx->rcvused), 0); | |
220 | } | |
221 | ||
222 | /** | |
223 | * Can the RX buffer still be written to? | |
224 | * | |
225 | * @sk socket of connection to user space | |
226 | * @return true => writable, false => not writable | |
227 | */ | |
228 | static inline bool af_alg_readable(struct sock *sk) | |
229 | { | |
230 | return PAGE_SIZE <= af_alg_rcvbuf(sk); | |
231 | } | |
232 | ||
233 | int af_alg_alloc_tsgl(struct sock *sk); | |
234 | unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset); | |
235 | void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst, | |
236 | size_t dst_offset); | |
237 | void af_alg_free_areq_sgls(struct af_alg_async_req *areq); | |
238 | int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags); | |
239 | void af_alg_wmem_wakeup(struct sock *sk); | |
240 | int af_alg_wait_for_data(struct sock *sk, unsigned flags); | |
241 | void af_alg_data_wakeup(struct sock *sk); | |
242 | int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size, | |
243 | unsigned int ivsize); | |
244 | ssize_t af_alg_sendpage(struct socket *sock, struct page *page, | |
245 | int offset, size_t size, int flags); | |
246 | void af_alg_free_resources(struct af_alg_async_req *areq); | |
247 | void af_alg_async_cb(struct crypto_async_request *_req, int err); | |
248 | unsigned int af_alg_poll(struct file *file, struct socket *sock, | |
249 | poll_table *wait); | |
250 | struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk, | |
251 | unsigned int areqlen); | |
252 | int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags, | |
253 | struct af_alg_async_req *areq, size_t maxsize, | |
254 | size_t *outlen); | |
255 | ||
256 | #endif /* _CRYPTO_IF_ALG_H */ |