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-rw-r--r--include/crypto/if_alg.h250
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 */