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Commit 0ae060ca authored by Trond Myklebust's avatar Trond Myklebust Committed by Anna Schumaker
Browse files

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: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent 9761a246

include/linux/sunrpc/xdr.h

+177 −0
Original line number Diff line number Diff line
@@ -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_ */