249 lines · c
1/* SPDX-License-Identifier: GPL-2.0-or-later */2/*3 * if_alg: User-space algorithm interface4 *5 * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>6 */7 8#ifndef _CRYPTO_IF_ALG_H9#define _CRYPTO_IF_ALG_H10 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 1623 24struct 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 37struct af_alg_control {38 struct af_alg_iv *iv;39 int op;40 unsigned int aead_assoclen;41};42 43struct 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 58struct 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 */65struct 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 */75struct 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 request83 * @iocb: IOCB for AIO operations84 * @sk: Socket the request is associated with85 * @first_rsgl: First RX SG86 * @last_rsgl: Pointer to last RX SG87 * @rsgl_list: Track RX SGs88 * @tsgl: Private, per request TX SGL of buffers to process89 * @tsgl_entries: Number of entries in priv. TX SGL90 * @outlen: Number of output bytes generated by crypto op91 * @areqlen: Length of this data structure92 * @cra_u: Cipher request93 */94struct 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 context118 *119 * The crypto context tracks the input data during the lifetime of an AF_ALG120 * socket.121 *122 * @tsgl_list: Link to TX SGL123 * @iv: IV for cipher operation124 * @state: Existing state for continuing operation125 * @aead_assoclen: Length of AAD for AEAD cipher operations126 * @completion: Work queue for synchronous operation127 * @used: TX bytes sent to kernel. This variable is used to128 * ensure that user space cannot cause the kernel129 * to allocate too much memory in sendmsg operation.130 * @rcvused: Total RX bytes to be filled by kernel. This variable131 * is used to ensure user space cannot cause the kernel132 * 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 existing135 * SG?136 * @enc: Cryptographic operation to be performed when137 * recvmsg is invoked.138 * @init: True if metadata has been sent.139 * @len: Length of memory allocated for this data structure.140 * @inflight: Non-zero when AIO requests are in flight.141 */142struct af_alg_ctx {143 struct list_head tsgl_list;144 145 void *iv;146 void *state;147 size_t aead_assoclen;148 149 struct crypto_wait wait;150 151 size_t used;152 atomic_t rcvused;153 154 bool more;155 bool merge;156 bool enc;157 bool init;158 159 unsigned int len;160 161 unsigned int inflight;162};163 164int af_alg_register_type(const struct af_alg_type *type);165int af_alg_unregister_type(const struct af_alg_type *type);166 167int af_alg_release(struct socket *sock);168void af_alg_release_parent(struct sock *sk);169int af_alg_accept(struct sock *sk, struct socket *newsock,170 struct proto_accept_arg *arg);171 172void af_alg_free_sg(struct af_alg_sgl *sgl);173 174static inline struct alg_sock *alg_sk(struct sock *sk)175{176 return (struct alg_sock *)sk;177}178 179/**180 * Size of available buffer for sending data from user space to kernel.181 *182 * @sk socket of connection to user space183 * @return number of bytes still available184 */185static inline int af_alg_sndbuf(struct sock *sk)186{187 struct alg_sock *ask = alg_sk(sk);188 struct af_alg_ctx *ctx = ask->private;189 190 return max_t(int, max_t(int, sk->sk_sndbuf & PAGE_MASK, PAGE_SIZE) -191 ctx->used, 0);192}193 194/**195 * Can the send buffer still be written to?196 *197 * @sk socket of connection to user space198 * @return true => writable, false => not writable199 */200static inline bool af_alg_writable(struct sock *sk)201{202 return PAGE_SIZE <= af_alg_sndbuf(sk);203}204 205/**206 * Size of available buffer used by kernel for the RX user space operation.207 *208 * @sk socket of connection to user space209 * @return number of bytes still available210 */211static inline int af_alg_rcvbuf(struct sock *sk)212{213 struct alg_sock *ask = alg_sk(sk);214 struct af_alg_ctx *ctx = ask->private;215 216 return max_t(int, max_t(int, sk->sk_rcvbuf & PAGE_MASK, PAGE_SIZE) -217 atomic_read(&ctx->rcvused), 0);218}219 220/**221 * Can the RX buffer still be written to?222 *223 * @sk socket of connection to user space224 * @return true => writable, false => not writable225 */226static inline bool af_alg_readable(struct sock *sk)227{228 return PAGE_SIZE <= af_alg_rcvbuf(sk);229}230 231unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset);232void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,233 size_t dst_offset);234void af_alg_wmem_wakeup(struct sock *sk);235int af_alg_wait_for_data(struct sock *sk, unsigned flags, unsigned min);236int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,237 unsigned int ivsize);238void af_alg_free_resources(struct af_alg_async_req *areq);239void af_alg_async_cb(void *data, int err);240__poll_t af_alg_poll(struct file *file, struct socket *sock,241 poll_table *wait);242struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,243 unsigned int areqlen);244int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,245 struct af_alg_async_req *areq, size_t maxsize,246 size_t *outlen);247 248#endif /* _CRYPTO_IF_ALG_H */249