/* SPDX-License-Identifier: GPL-2.0-or-later *//* * if_alg: User-space algorithm interface * * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au> */ #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 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);	void (*release)(void *private);	int (*setkey)(void *private, const u8 *key, unsigned int keylen);	int (*setentropy)(void *private, sockptr_t entropy, unsigned int len);	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 sg_table sgt;	struct scatterlist sgl[ALG_MAX_PAGES + 1];	bool need_unpin;}; /* TX SGL entry */struct af_alg_tsgl {	struct list_head list;	unsigned int cur;		/* Last processed SG entry */	struct scatterlist sg[];	/* 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 * @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 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 * @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. * @write:		True if we are in the middle of a write. * @init:		True if metadata has been sent. * @len:		Length of memory allocated for this data structure. * @inflight:		Non-zero when requests are in flight, for debugging only. */struct af_alg_ctx {	struct list_head tsgl_list; 	void *iv;	void *state;	size_t aead_assoclen; 	struct crypto_wait wait; 	size_t used;	atomic_t rcvused; 	bool		more:1,			merge:1,			enc:1,			write:1,			init:1; 	unsigned int len; 	unsigned int inflight;}; 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){	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);} unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes);void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst);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);__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); /* * Mask used to disable unsupported algorithm implementations. * * This is the same as FSCRYPT_CRYPTOAPI_MASK in fs/crypto/fscrypt_private.h. * In additions to the motivations there, this API is exposed to userspace * that might not be fully trusted. */#define AF_ALG_CRYPTOAPI_MASK                             \	(CRYPTO_ALG_ASYNC | CRYPTO_ALG_ALLOCATES_MEMORY | \	 CRYPTO_ALG_KERN_DRIVER_ONLY)  #endif	/* _CRYPTO_IF_ALG_H */