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Diffstat (limited to 'include/crypto/if_alg.h')
| -rw-r--r-- | include/crypto/if_alg.h | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/include/crypto/if_alg.h b/include/crypto/if_alg.h new file mode 100644 index 000000000..11f107df7 --- /dev/null +++ b/include/crypto/if_alg.h @@ -0,0 +1,256 @@ +/* + * if_alg: User-space algorithm interface + * + * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + * + */ + +#ifndef _CRYPTO_IF_ALG_H +#define _CRYPTO_IF_ALG_H + +#include <linux/compiler.h> +#include <linux/completion.h> +#include <linux/if_alg.h> +#include <linux/scatterlist.h> +#include <linux/types.h> +#include <linux/atomic.h> +#include <net/sock.h> + +#include <crypto/aead.h> +#include <crypto/skcipher.h> + +#define ALG_MAX_PAGES 16 + +struct crypto_async_request; + +struct alg_sock { + /* struct sock must be the first member of struct alg_sock */ + struct sock sk; + + struct sock *parent; + + atomic_t refcnt; + atomic_t nokey_refcnt; + + const struct af_alg_type *type; + void *private; +}; + +struct af_alg_control { + struct af_alg_iv *iv; + int op; + unsigned int aead_assoclen; +}; + +struct af_alg_type { + void *(*bind)(const char *name, u32 type, u32 mask); + void (*release)(void *private); + int (*setkey)(void *private, const u8 *key, unsigned int keylen); + int (*accept)(void *private, struct sock *sk); + int (*accept_nokey)(void *private, struct sock *sk); + int (*setauthsize)(void *private, unsigned int authsize); + + struct proto_ops *ops; + struct proto_ops *ops_nokey; + struct module *owner; + char name[14]; +}; + +struct af_alg_sgl { + struct scatterlist sg[ALG_MAX_PAGES + 1]; + struct page *pages[ALG_MAX_PAGES]; + unsigned int npages; +}; + +/* TX SGL entry */ +struct af_alg_tsgl { + struct list_head list; + unsigned int cur; /* Last processed SG entry */ + struct scatterlist sg[0]; /* Array of SGs forming the SGL */ +}; + +#define MAX_SGL_ENTS ((4096 - sizeof(struct af_alg_tsgl)) / \ + sizeof(struct scatterlist) - 1) + +/* RX SGL entry */ +struct af_alg_rsgl { + struct af_alg_sgl sgl; + struct list_head list; + size_t sg_num_bytes; /* Bytes of data in that SGL */ +}; + +/** + * struct af_alg_async_req - definition of crypto request + * @iocb: IOCB for AIO operations + * @sk: Socket the request is associated with + * @first_rsgl: First RX SG + * @last_rsgl: Pointer to last RX SG + * @rsgl_list: Track RX SGs + * @tsgl: Private, per request TX SGL of buffers to process + * @tsgl_entries: Number of entries in priv. TX SGL + * @outlen: Number of output bytes generated by crypto op + * @areqlen: Length of this data structure + * @cra_u: Cipher request + */ +struct af_alg_async_req { + struct kiocb *iocb; + struct sock *sk; + + struct af_alg_rsgl first_rsgl; + struct af_alg_rsgl *last_rsgl; + struct list_head rsgl_list; + + struct scatterlist *tsgl; + unsigned int tsgl_entries; + + unsigned int outlen; + unsigned int areqlen; + + union { + struct aead_request aead_req; + struct skcipher_request skcipher_req; + } cra_u; + + /* req ctx trails this struct */ +}; + +/** + * struct af_alg_ctx - definition of the crypto context + * + * The crypto context tracks the input data during the lifetime of an AF_ALG + * socket. + * + * @tsgl_list: Link to TX SGL + * @iv: IV for cipher operation + * @aead_assoclen: Length of AAD for AEAD cipher operations + * @completion: Work queue for synchronous operation + * @used: TX bytes sent to kernel. This variable is used to + * ensure that user space cannot cause the kernel + * to allocate too much memory in sendmsg operation. + * @rcvused: Total RX bytes to be filled by kernel. This variable + * is used to ensure user space cannot cause the kernel + * to allocate too much memory in a recvmsg operation. + * @more: More data to be expected from user space? + * @merge: Shall new data from user space be merged into existing + * SG? + * @enc: Cryptographic operation to be performed when + * recvmsg is invoked. + * @len: Length of memory allocated for this data structure. + */ +struct af_alg_ctx { + struct list_head tsgl_list; + + void *iv; + size_t aead_assoclen; + + struct crypto_wait wait; + + size_t used; + atomic_t rcvused; + + bool more; + bool merge; + bool enc; + + unsigned int len; +}; + +int af_alg_register_type(const struct af_alg_type *type); +int af_alg_unregister_type(const struct af_alg_type *type); + +int af_alg_release(struct socket *sock); +void af_alg_release_parent(struct sock *sk); +int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern); + +int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len); +void af_alg_free_sg(struct af_alg_sgl *sgl); +void af_alg_link_sg(struct af_alg_sgl *sgl_prev, struct af_alg_sgl *sgl_new); + +int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con); + +static inline struct alg_sock *alg_sk(struct sock *sk) +{ + return (struct alg_sock *)sk; +} + +/** + * Size of available buffer for sending data from user space to kernel. + * + * @sk socket of connection to user space + * @return number of bytes still available + */ +static inline int af_alg_sndbuf(struct sock *sk) +{ + struct alg_sock *ask = alg_sk(sk); + struct af_alg_ctx *ctx = ask->private; + + return max_t(int, max_t(int, sk->sk_sndbuf & PAGE_MASK, PAGE_SIZE) - + ctx->used, 0); +} + +/** + * Can the send buffer still be written to? + * + * @sk socket of connection to user space + * @return true => writable, false => not writable + */ +static inline bool af_alg_writable(struct sock *sk) +{ + return PAGE_SIZE <= af_alg_sndbuf(sk); +} + +/** + * Size of available buffer used by kernel for the RX user space operation. + * + * @sk socket of connection to user space + * @return number of bytes still available + */ +static inline int af_alg_rcvbuf(struct sock *sk) +{ + struct alg_sock *ask = alg_sk(sk); + struct af_alg_ctx *ctx = ask->private; + + return max_t(int, max_t(int, sk->sk_rcvbuf & PAGE_MASK, PAGE_SIZE) - + atomic_read(&ctx->rcvused), 0); +} + +/** + * Can the RX buffer still be written to? + * + * @sk socket of connection to user space + * @return true => writable, false => not writable + */ +static inline bool af_alg_readable(struct sock *sk) +{ + return PAGE_SIZE <= af_alg_rcvbuf(sk); +} + +int af_alg_alloc_tsgl(struct sock *sk); +unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset); +void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst, + size_t dst_offset); +void af_alg_free_areq_sgls(struct af_alg_async_req *areq); +int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags); +void af_alg_wmem_wakeup(struct sock *sk); +int af_alg_wait_for_data(struct sock *sk, unsigned flags); +void af_alg_data_wakeup(struct sock *sk); +int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size, + unsigned int ivsize); +ssize_t af_alg_sendpage(struct socket *sock, struct page *page, + int offset, size_t size, int flags); +void af_alg_free_resources(struct af_alg_async_req *areq); +void af_alg_async_cb(struct crypto_async_request *_req, int err); +__poll_t af_alg_poll(struct file *file, struct socket *sock, + poll_table *wait); +struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk, + unsigned int areqlen); +int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags, + struct af_alg_async_req *areq, size_t maxsize, + size_t *outlen); + +#endif /* _CRYPTO_IF_ALG_H */ |