1 files changed, 250 insertions, 0 deletions
diff --git a/include/crypto/if_alg.h b/include/crypto/if_alg.h
new file mode 100644
index 000000000..a406e281a
--- /dev/null
+++ b/include/crypto/if_alg.h
@@ -0,0 +1,250 @@
+/* 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 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 (*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 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[];	/* 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.
+ * @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 {
+	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;
+	bool init;
+
+	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, 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);
+
+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, 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);
+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 */