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03c8efc1 HX |
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> | |
b7f080cf | 19 | #include <linux/scatterlist.h> |
03c8efc1 HX |
20 | #include <linux/types.h> |
21 | #include <net/sock.h> | |
22 | ||
2d97591e SM |
23 | #include <crypto/aead.h> |
24 | #include <crypto/skcipher.h> | |
25 | ||
03c8efc1 HX |
26 | #define ALG_MAX_PAGES 16 |
27 | ||
28 | struct crypto_async_request; | |
29 | ||
30 | struct alg_sock { | |
31 | /* struct sock must be the first member of struct alg_sock */ | |
32 | struct sock sk; | |
33 | ||
34 | struct sock *parent; | |
35 | ||
c840ac6a | 36 | unsigned int refcnt; |
6a935170 | 37 | unsigned int nokey_refcnt; |
c840ac6a | 38 | |
03c8efc1 HX |
39 | const struct af_alg_type *type; |
40 | void *private; | |
41 | }; | |
42 | ||
03c8efc1 HX |
43 | struct af_alg_control { |
44 | struct af_alg_iv *iv; | |
45 | int op; | |
af8e8073 | 46 | unsigned int aead_assoclen; |
03c8efc1 HX |
47 | }; |
48 | ||
49 | struct af_alg_type { | |
50 | void *(*bind)(const char *name, u32 type, u32 mask); | |
51 | void (*release)(void *private); | |
52 | int (*setkey)(void *private, const u8 *key, unsigned int keylen); | |
53 | int (*accept)(void *private, struct sock *sk); | |
37766586 | 54 | int (*accept_nokey)(void *private, struct sock *sk); |
25fb8638 | 55 | int (*setauthsize)(void *private, unsigned int authsize); |
03c8efc1 HX |
56 | |
57 | struct proto_ops *ops; | |
37766586 | 58 | struct proto_ops *ops_nokey; |
03c8efc1 HX |
59 | struct module *owner; |
60 | char name[14]; | |
61 | }; | |
62 | ||
63 | struct af_alg_sgl { | |
66db3739 | 64 | struct scatterlist sg[ALG_MAX_PAGES + 1]; |
03c8efc1 | 65 | struct page *pages[ALG_MAX_PAGES]; |
66db3739 | 66 | unsigned int npages; |
03c8efc1 HX |
67 | }; |
68 | ||
2d97591e SM |
69 | /* TX SGL entry */ |
70 | struct af_alg_tsgl { | |
71 | struct list_head list; | |
72 | unsigned int cur; /* Last processed SG entry */ | |
73 | struct scatterlist sg[0]; /* Array of SGs forming the SGL */ | |
74 | }; | |
75 | ||
76 | #define MAX_SGL_ENTS ((4096 - sizeof(struct af_alg_tsgl)) / \ | |
77 | sizeof(struct scatterlist) - 1) | |
78 | ||
79 | /* RX SGL entry */ | |
80 | struct af_alg_rsgl { | |
81 | struct af_alg_sgl sgl; | |
82 | struct list_head list; | |
83 | size_t sg_num_bytes; /* Bytes of data in that SGL */ | |
84 | }; | |
85 | ||
86 | /** | |
87 | * struct af_alg_async_req - definition of crypto request | |
88 | * @iocb: IOCB for AIO operations | |
89 | * @sk: Socket the request is associated with | |
90 | * @first_rsgl: First RX SG | |
91 | * @last_rsgl: Pointer to last RX SG | |
92 | * @rsgl_list: Track RX SGs | |
93 | * @tsgl: Private, per request TX SGL of buffers to process | |
94 | * @tsgl_entries: Number of entries in priv. TX SGL | |
95 | * @outlen: Number of output bytes generated by crypto op | |
96 | * @areqlen: Length of this data structure | |
97 | * @cra_u: Cipher request | |
98 | */ | |
99 | struct af_alg_async_req { | |
100 | struct kiocb *iocb; | |
101 | struct sock *sk; | |
102 | ||
103 | struct af_alg_rsgl first_rsgl; | |
104 | struct af_alg_rsgl *last_rsgl; | |
105 | struct list_head rsgl_list; | |
106 | ||
107 | struct scatterlist *tsgl; | |
108 | unsigned int tsgl_entries; | |
109 | ||
110 | unsigned int outlen; | |
111 | unsigned int areqlen; | |
112 | ||
113 | union { | |
114 | struct aead_request aead_req; | |
115 | struct skcipher_request skcipher_req; | |
116 | } cra_u; | |
117 | ||
118 | /* req ctx trails this struct */ | |
119 | }; | |
120 | ||
121 | /** | |
122 | * struct af_alg_ctx - definition of the crypto context | |
123 | * | |
124 | * The crypto context tracks the input data during the lifetime of an AF_ALG | |
125 | * socket. | |
126 | * | |
127 | * @tsgl_list: Link to TX SGL | |
128 | * @iv: IV for cipher operation | |
129 | * @aead_assoclen: Length of AAD for AEAD cipher operations | |
130 | * @completion: Work queue for synchronous operation | |
131 | * @used: TX bytes sent to kernel. This variable is used to | |
132 | * ensure that user space cannot cause the kernel | |
133 | * to allocate too much memory in sendmsg operation. | |
134 | * @rcvused: Total RX bytes to be filled by kernel. This variable | |
135 | * is used to ensure user space cannot cause the kernel | |
136 | * to allocate too much memory in a recvmsg operation. | |
137 | * @more: More data to be expected from user space? | |
138 | * @merge: Shall new data from user space be merged into existing | |
139 | * SG? | |
140 | * @enc: Cryptographic operation to be performed when | |
141 | * recvmsg is invoked. | |
142 | * @len: Length of memory allocated for this data structure. | |
143 | */ | |
144 | struct af_alg_ctx { | |
145 | struct list_head tsgl_list; | |
146 | ||
147 | void *iv; | |
148 | size_t aead_assoclen; | |
149 | ||
2c3f8b16 | 150 | struct crypto_wait wait; |
2d97591e SM |
151 | |
152 | size_t used; | |
153 | size_t rcvused; | |
154 | ||
155 | bool more; | |
156 | bool merge; | |
157 | bool enc; | |
158 | ||
159 | unsigned int len; | |
160 | }; | |
161 | ||
03c8efc1 HX |
162 | int af_alg_register_type(const struct af_alg_type *type); |
163 | int af_alg_unregister_type(const struct af_alg_type *type); | |
164 | ||
165 | int af_alg_release(struct socket *sock); | |
c840ac6a | 166 | void af_alg_release_parent(struct sock *sk); |
cdfbabfb | 167 | int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern); |
03c8efc1 | 168 | |
1d10eb2f | 169 | int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len); |
03c8efc1 | 170 | void af_alg_free_sg(struct af_alg_sgl *sgl); |
66db3739 | 171 | void af_alg_link_sg(struct af_alg_sgl *sgl_prev, struct af_alg_sgl *sgl_new); |
03c8efc1 HX |
172 | |
173 | int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con); | |
174 | ||
03c8efc1 HX |
175 | static inline struct alg_sock *alg_sk(struct sock *sk) |
176 | { | |
177 | return (struct alg_sock *)sk; | |
178 | } | |
179 | ||
2d97591e SM |
180 | /** |
181 | * Size of available buffer for sending data from user space to kernel. | |
182 | * | |
183 | * @sk socket of connection to user space | |
184 | * @return number of bytes still available | |
185 | */ | |
186 | static inline int af_alg_sndbuf(struct sock *sk) | |
187 | { | |
188 | struct alg_sock *ask = alg_sk(sk); | |
189 | struct af_alg_ctx *ctx = ask->private; | |
190 | ||
191 | return max_t(int, max_t(int, sk->sk_sndbuf & PAGE_MASK, PAGE_SIZE) - | |
192 | ctx->used, 0); | |
193 | } | |
194 | ||
195 | /** | |
196 | * Can the send buffer still be written to? | |
197 | * | |
198 | * @sk socket of connection to user space | |
199 | * @return true => writable, false => not writable | |
200 | */ | |
201 | static inline bool af_alg_writable(struct sock *sk) | |
202 | { | |
203 | return PAGE_SIZE <= af_alg_sndbuf(sk); | |
204 | } | |
205 | ||
206 | /** | |
207 | * Size of available buffer used by kernel for the RX user space operation. | |
208 | * | |
209 | * @sk socket of connection to user space | |
210 | * @return number of bytes still available | |
211 | */ | |
212 | static inline int af_alg_rcvbuf(struct sock *sk) | |
213 | { | |
214 | struct alg_sock *ask = alg_sk(sk); | |
215 | struct af_alg_ctx *ctx = ask->private; | |
216 | ||
217 | return max_t(int, max_t(int, sk->sk_rcvbuf & PAGE_MASK, PAGE_SIZE) - | |
218 | ctx->rcvused, 0); | |
219 | } | |
220 | ||
221 | /** | |
222 | * Can the RX buffer still be written to? | |
223 | * | |
224 | * @sk socket of connection to user space | |
225 | * @return true => writable, false => not writable | |
226 | */ | |
227 | static inline bool af_alg_readable(struct sock *sk) | |
228 | { | |
229 | return PAGE_SIZE <= af_alg_rcvbuf(sk); | |
230 | } | |
231 | ||
232 | int af_alg_alloc_tsgl(struct sock *sk); | |
233 | unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset); | |
234 | void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst, | |
235 | size_t dst_offset); | |
236 | void af_alg_free_areq_sgls(struct af_alg_async_req *areq); | |
237 | int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags); | |
238 | void af_alg_wmem_wakeup(struct sock *sk); | |
239 | int af_alg_wait_for_data(struct sock *sk, unsigned flags); | |
240 | void af_alg_data_wakeup(struct sock *sk); | |
241 | int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size, | |
242 | unsigned int ivsize); | |
243 | ssize_t af_alg_sendpage(struct socket *sock, struct page *page, | |
244 | int offset, size_t size, int flags); | |
245 | void af_alg_async_cb(struct crypto_async_request *_req, int err); | |
246 | unsigned int af_alg_poll(struct file *file, struct socket *sock, | |
247 | poll_table *wait); | |
248 | struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk, | |
249 | unsigned int areqlen); | |
250 | int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags, | |
251 | struct af_alg_async_req *areq, size_t maxsize, | |
252 | size_t *outlen); | |
253 | ||
03c8efc1 | 254 | #endif /* _CRYPTO_IF_ALG_H */ |