linux/include/crypto/if_alg.h

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * if_alg: User-space algorithm interface
 *
 * Copyright (c) 2010 Herbert Xu <[email protected]>
 */

#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 …

struct alg_sock { … };

struct af_alg_control { … };

struct af_alg_type { … };

struct af_alg_sgl { … };

/* TX SGL entry */
struct af_alg_tsgl { … };

#define MAX_SGL_ENTS …

/* RX SGL entry */
struct af_alg_rsgl { … };

/**
 * 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 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
 * @state:		Existing state for continuing 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.
 * @init:		True if metadata has been sent.
 * @len:		Length of memory allocated for this data structure.
 * @inflight:		Non-zero when AIO requests are in flight.
 */
struct af_alg_ctx { … };

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,
		  struct proto_accept_arg *arg);

void af_alg_free_sg(struct af_alg_sgl *sgl);

static inline struct alg_sock *alg_sk(struct 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)
{ … }

/**
 * 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)
{ … }

/**
 * 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)
{ … }

/**
 * 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)
{ … }

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_wmem_wakeup(struct sock *sk);
int af_alg_wait_for_data(struct sock *sk, unsigned flags, unsigned min);
int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
		   unsigned int ivsize);
void af_alg_free_resources(struct af_alg_async_req *areq);
void af_alg_async_cb(void *data, 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 */