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 * @aead_assoclen: Length of AAD for AEAD cipher operations 125 * @completion: Work queue for synchronous operation 126 * @used: TX bytes sent to kernel. This variable is used to 127 * ensure that user space cannot cause the kernel 128 * to allocate too much memory in sendmsg operation. 129 * @rcvused: Total RX bytes to be filled by kernel. This variable 130 * is used to ensure user space cannot cause the kernel 131 * to allocate too much memory in a recvmsg operation. 132 * @more: More data to be expected from user space? 133 * @merge: Shall new data from user space be merged into existing 134 * SG? 135 * @enc: Cryptographic operation to be performed when 136 * recvmsg is invoked. 137 * @init: True if metadata has been sent. 138 * @len: Length of memory allocated for this data structure. 139 * @inflight: Non-zero when AIO requests are in flight. 140 */ 141 struct af_alg_ctx { 142 struct list_head tsgl_list; 143 144 void *iv; 145 size_t aead_assoclen; 146 147 struct crypto_wait wait; 148 149 size_t used; 150 atomic_t rcvused; 151 152 bool more; 153 bool merge; 154 bool enc; 155 bool init; 156 157 unsigned int len; 158 159 unsigned int inflight; 160 }; 161 162 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); 166 void af_alg_release_parent(struct sock *sk); 167 int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern); 168 169 void af_alg_free_sg(struct af_alg_sgl *sgl); 170 171 static 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 */ 182 static 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 */ 197 static 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 */ 208 static 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 */ 223 static inline bool af_alg_readable(struct sock *sk) 224 { 225 return PAGE_SIZE <= af_alg_rcvbuf(sk); 226 } 227 228 unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset); 229 void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst, 230 size_t dst_offset); 231 void af_alg_wmem_wakeup(struct sock *sk); 232 int af_alg_wait_for_data(struct sock *sk, unsigned flags, unsigned min); 233 int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size, 234 unsigned int ivsize); 235 void af_alg_free_resources(struct af_alg_async_req *areq); 236 void af_alg_async_cb(void *data, int err); 237 __poll_t af_alg_poll(struct file *file, struct socket *sock, 238 poll_table *wait); 239 struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk, 240 unsigned int areqlen); 241 int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags, 242 struct af_alg_async_req *areq, size_t maxsize, 243 size_t *outlen); 244 245 #endif /* _CRYPTO_IF_ALG_H */ 246