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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 <net/sock.h>
22
23#define ALG_MAX_PAGES 16
24
25struct crypto_async_request;
26
27struct alg_sock {
28 /* struct sock must be the first member of struct alg_sock */
29 struct sock sk;
30
31 struct sock *parent;
32
33 const struct af_alg_type *type;
34 void *private;
35};
36
37struct af_alg_completion {
38 struct completion completion;
39 int err;
40};
41
42struct af_alg_control {
43 struct af_alg_iv *iv;
44 int op;
45};
46
47struct af_alg_type {
48 void *(*bind)(const char *name, u32 type, u32 mask);
49 void (*release)(void *private);
50 int (*setkey)(void *private, const u8 *key, unsigned int keylen);
51 int (*accept)(void *private, struct sock *sk);
52
53 struct proto_ops *ops;
54 struct module *owner;
55 char name[14];
56};
57
58struct af_alg_sgl {
59 struct scatterlist sg[ALG_MAX_PAGES];
60 struct page *pages[ALG_MAX_PAGES];
61};
62
63int af_alg_register_type(const struct af_alg_type *type);
64int af_alg_unregister_type(const struct af_alg_type *type);
65
66int af_alg_release(struct socket *sock);
67int af_alg_accept(struct sock *sk, struct socket *newsock);
68
69int af_alg_make_sg(struct af_alg_sgl *sgl, void __user *addr, int len,
70 int write);
71void af_alg_free_sg(struct af_alg_sgl *sgl);
72
73int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con);
74
75int af_alg_wait_for_completion(int err, struct af_alg_completion *completion);
76void af_alg_complete(struct crypto_async_request *req, int err);
77
78static inline struct alg_sock *alg_sk(struct sock *sk)
79{
80 return (struct alg_sock *)sk;
81}
82
83static inline void af_alg_release_parent(struct sock *sk)
84{
85 sock_put(alg_sk(sk)->parent);
86}
87
88static inline void af_alg_init_completion(struct af_alg_completion *completion)
89{
90 init_completion(&completion->completion);
91}
92
93#endif /* _CRYPTO_IF_ALG_H */
1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * if_alg: User-space algorithm interface
4 *
5 * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
6 */
7
8#ifndef _CRYPTO_IF_ALG_H
9#define _CRYPTO_IF_ALG_H
10
11#include <linux/compiler.h>
12#include <linux/completion.h>
13#include <linux/if_alg.h>
14#include <linux/scatterlist.h>
15#include <linux/types.h>
16#include <linux/atomic.h>
17#include <net/sock.h>
18
19#include <crypto/aead.h>
20#include <crypto/skcipher.h>
21
22#define ALG_MAX_PAGES 16
23
24struct crypto_async_request;
25
26struct alg_sock {
27 /* struct sock must be the first member of struct alg_sock */
28 struct sock sk;
29
30 struct sock *parent;
31
32 atomic_t refcnt;
33 atomic_t nokey_refcnt;
34
35 const struct af_alg_type *type;
36 void *private;
37};
38
39struct af_alg_control {
40 struct af_alg_iv *iv;
41 int op;
42 unsigned int aead_assoclen;
43};
44
45struct af_alg_type {
46 void *(*bind)(const char *name, u32 type, u32 mask);
47 void (*release)(void *private);
48 int (*setkey)(void *private, const u8 *key, unsigned int keylen);
49 int (*setentropy)(void *private, sockptr_t entropy, unsigned int len);
50 int (*accept)(void *private, struct sock *sk);
51 int (*accept_nokey)(void *private, struct sock *sk);
52 int (*setauthsize)(void *private, unsigned int authsize);
53
54 struct proto_ops *ops;
55 struct proto_ops *ops_nokey;
56 struct module *owner;
57 char name[14];
58};
59
60struct af_alg_sgl {
61 struct scatterlist sg[ALG_MAX_PAGES + 1];
62 struct page *pages[ALG_MAX_PAGES];
63 unsigned int npages;
64};
65
66/* TX SGL entry */
67struct af_alg_tsgl {
68 struct list_head list;
69 unsigned int cur; /* Last processed SG entry */
70 struct scatterlist sg[]; /* Array of SGs forming the SGL */
71};
72
73#define MAX_SGL_ENTS ((4096 - sizeof(struct af_alg_tsgl)) / \
74 sizeof(struct scatterlist) - 1)
75
76/* RX SGL entry */
77struct af_alg_rsgl {
78 struct af_alg_sgl sgl;
79 struct list_head list;
80 size_t sg_num_bytes; /* Bytes of data in that SGL */
81};
82
83/**
84 * struct af_alg_async_req - definition of crypto request
85 * @iocb: IOCB for AIO operations
86 * @sk: Socket the request is associated with
87 * @first_rsgl: First RX SG
88 * @last_rsgl: Pointer to last RX SG
89 * @rsgl_list: Track RX SGs
90 * @tsgl: Private, per request TX SGL of buffers to process
91 * @tsgl_entries: Number of entries in priv. TX SGL
92 * @outlen: Number of output bytes generated by crypto op
93 * @areqlen: Length of this data structure
94 * @cra_u: Cipher request
95 */
96struct af_alg_async_req {
97 struct kiocb *iocb;
98 struct sock *sk;
99
100 struct af_alg_rsgl first_rsgl;
101 struct af_alg_rsgl *last_rsgl;
102 struct list_head rsgl_list;
103
104 struct scatterlist *tsgl;
105 unsigned int tsgl_entries;
106
107 unsigned int outlen;
108 unsigned int areqlen;
109
110 union {
111 struct aead_request aead_req;
112 struct skcipher_request skcipher_req;
113 } cra_u;
114
115 /* req ctx trails this struct */
116};
117
118/**
119 * struct af_alg_ctx - definition of the crypto context
120 *
121 * The crypto context tracks the input data during the lifetime of an AF_ALG
122 * socket.
123 *
124 * @tsgl_list: Link to TX SGL
125 * @iv: IV for cipher operation
126 * @aead_assoclen: Length of AAD for AEAD cipher operations
127 * @completion: Work queue for synchronous operation
128 * @used: TX bytes sent to kernel. This variable is used to
129 * ensure that user space cannot cause the kernel
130 * to allocate too much memory in sendmsg operation.
131 * @rcvused: Total RX bytes to be filled by kernel. This variable
132 * is used to ensure user space cannot cause the kernel
133 * to allocate too much memory in a recvmsg operation.
134 * @more: More data to be expected from user space?
135 * @merge: Shall new data from user space be merged into existing
136 * SG?
137 * @enc: Cryptographic operation to be performed when
138 * recvmsg is invoked.
139 * @init: True if metadata has been sent.
140 * @len: Length of memory allocated for this data structure.
141 */
142struct af_alg_ctx {
143 struct list_head tsgl_list;
144
145 void *iv;
146 size_t aead_assoclen;
147
148 struct crypto_wait wait;
149
150 size_t used;
151 atomic_t rcvused;
152
153 bool more;
154 bool merge;
155 bool enc;
156 bool init;
157
158 unsigned int len;
159};
160
161int af_alg_register_type(const struct af_alg_type *type);
162int af_alg_unregister_type(const struct af_alg_type *type);
163
164int af_alg_release(struct socket *sock);
165void af_alg_release_parent(struct sock *sk);
166int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern);
167
168int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len);
169void af_alg_free_sg(struct af_alg_sgl *sgl);
170
171static inline struct alg_sock *alg_sk(struct sock *sk)
172{
173 return (struct alg_sock *)sk;
174}
175
176/**
177 * Size of available buffer for sending data from user space to kernel.
178 *
179 * @sk socket of connection to user space
180 * @return number of bytes still available
181 */
182static inline int af_alg_sndbuf(struct sock *sk)
183{
184 struct alg_sock *ask = alg_sk(sk);
185 struct af_alg_ctx *ctx = ask->private;
186
187 return max_t(int, max_t(int, sk->sk_sndbuf & PAGE_MASK, PAGE_SIZE) -
188 ctx->used, 0);
189}
190
191/**
192 * Can the send buffer still be written to?
193 *
194 * @sk socket of connection to user space
195 * @return true => writable, false => not writable
196 */
197static inline bool af_alg_writable(struct sock *sk)
198{
199 return PAGE_SIZE <= af_alg_sndbuf(sk);
200}
201
202/**
203 * Size of available buffer used by kernel for the RX user space operation.
204 *
205 * @sk socket of connection to user space
206 * @return number of bytes still available
207 */
208static inline int af_alg_rcvbuf(struct sock *sk)
209{
210 struct alg_sock *ask = alg_sk(sk);
211 struct af_alg_ctx *ctx = ask->private;
212
213 return max_t(int, max_t(int, sk->sk_rcvbuf & PAGE_MASK, PAGE_SIZE) -
214 atomic_read(&ctx->rcvused), 0);
215}
216
217/**
218 * Can the RX buffer still be written to?
219 *
220 * @sk socket of connection to user space
221 * @return true => writable, false => not writable
222 */
223static inline bool af_alg_readable(struct sock *sk)
224{
225 return PAGE_SIZE <= af_alg_rcvbuf(sk);
226}
227
228unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset);
229void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
230 size_t dst_offset);
231void af_alg_wmem_wakeup(struct sock *sk);
232int af_alg_wait_for_data(struct sock *sk, unsigned flags, unsigned min);
233int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
234 unsigned int ivsize);
235ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
236 int offset, size_t size, int flags);
237void af_alg_free_resources(struct af_alg_async_req *areq);
238void af_alg_async_cb(struct crypto_async_request *_req, int err);
239__poll_t af_alg_poll(struct file *file, struct socket *sock,
240 poll_table *wait);
241struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
242 unsigned int areqlen);
243int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
244 struct af_alg_async_req *areq, size_t maxsize,
245 size_t *outlen);
246
247#endif /* _CRYPTO_IF_ALG_H */