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 alg_sock { 25 /* struct sock must be the first member of struct alg_sock */ 26 struct sock sk; 27 28 struct sock *parent; 29 30 atomic_t refcnt; 31 atomic_t nokey_refcnt; 32 33 const struct af_alg_type *type; 34 void *private; 35 }; 36 37 struct af_alg_control { 38 struct af_alg_iv *iv; 39 int op; 40 unsigned int aead_assoclen; 41 }; 42 43 struct af_alg_type { 44 void *(*bind)(const char *name, u32 type, u32 mask); 45 void (*release)(void *private); 46 int (*setkey)(void *private, const u8 *key, unsigned int keylen); 47 int (*setentropy)(void *private, sockptr_t entropy, unsigned int len); 48 int (*accept)(void *private, struct sock *sk); 49 int (*accept_nokey)(void *private, struct sock *sk); 50 int (*setauthsize)(void *private, unsigned int authsize); 51 52 struct proto_ops *ops; 53 struct proto_ops *ops_nokey; 54 struct module *owner; 55 char name[14]; 56 }; 57 58 struct af_alg_sgl { 59 struct sg_table sgt; 60 struct scatterlist sgl[ALG_MAX_PAGES + 1]; 61 bool need_unpin; 62 }; 63 64 /* TX SGL entry */ 65 struct af_alg_tsgl { 66 struct list_head list; 67 unsigned int cur; /* Last processed SG entry */ 68 struct scatterlist sg[]; /* Array of SGs forming the SGL */ 69 }; 70 71 #define MAX_SGL_ENTS ((4096 - sizeof(struct af_alg_tsgl)) / \ 72 sizeof(struct scatterlist) - 1) 73 74 /* RX SGL entry */ 75 struct af_alg_rsgl { 76 struct af_alg_sgl sgl; 77 struct list_head list; 78 size_t sg_num_bytes; /* Bytes of data in that SGL */ 79 }; 80 81 /** 82 * struct af_alg_async_req - definition of crypto request 83 * @iocb: IOCB for AIO operations 84 * @sk: Socket the request is associated with 85 * @first_rsgl: First RX SG 86 * @last_rsgl: Pointer to last RX SG 87 * @rsgl_list: Track RX SGs 88 * @tsgl: Private, per request TX SGL of buffers to process 89 * @tsgl_entries: Number of entries in priv. TX SGL 90 * @outlen: Number of output bytes generated by crypto op 91 * @areqlen: Length of this data structure 92 * @cra_u: Cipher request 93 */ 94 struct af_alg_async_req { 95 struct kiocb *iocb; 96 struct sock *sk; 97 98 struct af_alg_rsgl first_rsgl; 99 struct af_alg_rsgl *last_rsgl; 100 struct list_head rsgl_list; 101 102 struct scatterlist *tsgl; 103 unsigned int tsgl_entries; 104 105 unsigned int outlen; 106 unsigned int areqlen; 107 108 union { 109 struct aead_request aead_req; 110 struct skcipher_request skcipher_req; 111 } cra_u; 112 113 /* req ctx trails this struct */ 114 }; 115 116 /** 117 * struct af_alg_ctx - definition of the crypto context 118 * 119 * The crypto context tracks the input data during the lifetime of an AF_ALG 120 * socket. 121 * 122 * @tsgl_list: Link to TX SGL 123 * @iv: IV for cipher operation 124 * @state: Existing state for continuing 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 * @write: True if we are in the middle of a write. 139 * @init: True if metadata has been sent. 140 * @len: Length of memory allocated for this data structure. 141 * @inflight: Non-zero when AIO requests are in flight. 142 */ 143 struct af_alg_ctx { 144 struct list_head tsgl_list; 145 146 void *iv; 147 void *state; 148 size_t aead_assoclen; 149 150 struct crypto_wait wait; 151 152 size_t used; 153 atomic_t rcvused; 154 155 bool more:1, 156 merge:1, 157 enc:1, 158 write:1, 159 init:1; 160 161 unsigned int len; 162 163 unsigned int inflight; 164 }; 165 166 int af_alg_register_type(const struct af_alg_type *type); 167 int af_alg_unregister_type(const struct af_alg_type *type); 168 169 int af_alg_release(struct socket *sock); 170 void af_alg_release_parent(struct sock *sk); 171 int af_alg_accept(struct sock *sk, struct socket *newsock, 172 struct proto_accept_arg *arg); 173 174 void af_alg_free_sg(struct af_alg_sgl *sgl); 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 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_wmem_wakeup(struct sock *sk); 237 int af_alg_wait_for_data(struct sock *sk, unsigned flags, unsigned min); 238 int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size, 239 unsigned int ivsize); 240 void af_alg_free_resources(struct af_alg_async_req *areq); 241 void af_alg_async_cb(void *data, int err); 242 __poll_t af_alg_poll(struct file *file, struct socket *sock, 243 poll_table *wait); 244 struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk, 245 unsigned int areqlen); 246 int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags, 247 struct af_alg_async_req *areq, size_t maxsize, 248 size_t *outlen); 249 250 #endif /* _CRYPTO_IF_ALG_H */ 251