From 0ae060ca2bdfe11181094699b0f76437ec210b17 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sun, 19 Feb 2017 16:08:25 -0500 Subject: [PATCH] SUNRPC: Add generic helpers for xdr_stream encode/decode Add some generic helpers for encoding/decoding opaque structures and basic u32/u64. Signed-off-by: Trond Myklebust Reviewed-by: Chuck Lever Signed-off-by: Anna Schumaker --- include/linux/sunrpc/xdr.h | 177 +++++++++++++++++++++++++++++++++++++ 1 file changed, 177 insertions(+) diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h index 56c48c884a24..dc7e51a769ac 100644 --- a/include/linux/sunrpc/xdr.h +++ b/include/linux/sunrpc/xdr.h @@ -242,6 +242,183 @@ extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len); extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len); extern int xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data); +/** + * xdr_align_size - Calculate padded size of an object + * @n: Size of an object being XDR encoded (in bytes) + * + * Return value: + * Size (in bytes) of the object including xdr padding + */ +static inline size_t +xdr_align_size(size_t n) +{ + const size_t mask = sizeof(__u32) - 1; + + return (n + mask) & ~mask; +} + +/** + * xdr_stream_encode_u32 - Encode a 32-bit integer + * @xdr: pointer to xdr_stream + * @n: integer to encode + * + * Return values: + * On success, returns length in bytes of XDR buffer consumed + * %-EMSGSIZE on XDR buffer overflow + */ +static inline ssize_t +xdr_stream_encode_u32(struct xdr_stream *xdr, __u32 n) +{ + const size_t len = sizeof(n); + __be32 *p = xdr_reserve_space(xdr, len); + + if (unlikely(!p)) + return -EMSGSIZE; + *p = cpu_to_be32(n); + return len; +} + +/** + * xdr_stream_encode_u64 - Encode a 64-bit integer + * @xdr: pointer to xdr_stream + * @n: 64-bit integer to encode + * + * Return values: + * On success, returns length in bytes of XDR buffer consumed + * %-EMSGSIZE on XDR buffer overflow + */ +static inline ssize_t +xdr_stream_encode_u64(struct xdr_stream *xdr, __u64 n) +{ + const size_t len = sizeof(n); + __be32 *p = xdr_reserve_space(xdr, len); + + if (unlikely(!p)) + return -EMSGSIZE; + xdr_encode_hyper(p, n); + return len; +} + +/** + * xdr_stream_encode_opaque_fixed - Encode fixed length opaque xdr data + * @xdr: pointer to xdr_stream + * @ptr: pointer to opaque data object + * @len: size of object pointed to by @ptr + * + * Return values: + * On success, returns length in bytes of XDR buffer consumed + * %-EMSGSIZE on XDR buffer overflow + */ +static inline ssize_t +xdr_stream_encode_opaque_fixed(struct xdr_stream *xdr, const void *ptr, size_t len) +{ + __be32 *p = xdr_reserve_space(xdr, len); + + if (unlikely(!p)) + return -EMSGSIZE; + xdr_encode_opaque_fixed(p, ptr, len); + return xdr_align_size(len); +} + +/** + * xdr_stream_encode_opaque - Encode variable length opaque xdr data + * @xdr: pointer to xdr_stream + * @ptr: pointer to opaque data object + * @len: size of object pointed to by @ptr + * + * Return values: + * On success, returns length in bytes of XDR buffer consumed + * %-EMSGSIZE on XDR buffer overflow + */ +static inline ssize_t +xdr_stream_encode_opaque(struct xdr_stream *xdr, const void *ptr, size_t len) +{ + size_t count = sizeof(__u32) + xdr_align_size(len); + __be32 *p = xdr_reserve_space(xdr, count); + + if (unlikely(!p)) + return -EMSGSIZE; + xdr_encode_opaque(p, ptr, len); + return count; +} + +/** + * xdr_stream_decode_u32 - Decode a 32-bit integer + * @xdr: pointer to xdr_stream + * @ptr: location to store integer + * + * Return values: + * %0 on success + * %-EBADMSG on XDR buffer overflow + */ +static inline ssize_t +xdr_stream_decode_u32(struct xdr_stream *xdr, __u32 *ptr) +{ + const size_t count = sizeof(*ptr); + __be32 *p = xdr_inline_decode(xdr, count); + + if (unlikely(!p)) + return -EBADMSG; + *ptr = be32_to_cpup(p); + return 0; +} + +/** + * xdr_stream_decode_opaque_fixed - Decode fixed length opaque xdr data + * @xdr: pointer to xdr_stream + * @ptr: location to store data + * @len: size of buffer pointed to by @ptr + * + * Return values: + * On success, returns size of object stored in @ptr + * %-EBADMSG on XDR buffer overflow + */ +static inline ssize_t +xdr_stream_decode_opaque_fixed(struct xdr_stream *xdr, void *ptr, size_t len) +{ + __be32 *p = xdr_inline_decode(xdr, len); + + if (unlikely(!p)) + return -EBADMSG; + xdr_decode_opaque_fixed(p, ptr, len); + return len; +} + +/** + * xdr_stream_decode_opaque_inline - Decode variable length opaque xdr data + * @xdr: pointer to xdr_stream + * @ptr: location to store pointer to opaque data + * @maxlen: maximum acceptable object size + * + * Note: the pointer stored in @ptr cannot be assumed valid after the XDR + * buffer has been destroyed, or even after calling xdr_inline_decode() + * on @xdr. It is therefore expected that the object it points to should + * be processed immediately. + * + * Return values: + * On success, returns size of object stored in *@ptr + * %-EBADMSG on XDR buffer overflow + * %-EMSGSIZE if the size of the object would exceed @maxlen + */ +static inline ssize_t +xdr_stream_decode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t maxlen) +{ + __be32 *p; + __u32 len; + + *ptr = NULL; + if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0)) + return -EBADMSG; + if (len != 0) { + p = xdr_inline_decode(xdr, len); + if (unlikely(!p)) + return -EBADMSG; + if (unlikely(len > maxlen)) + return -EMSGSIZE; + *ptr = p; + } + return len; +} #endif /* __KERNEL__ */ #endif /* _SUNRPC_XDR_H_ */ -- 2.20.1