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