/*

 * include/linux/sunrpc/xdr.h

 *

 * Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>

 */

#ifndef _SUNRPC_XDR_H_

#define _SUNRPC_XDR_H_

#ifdef __KERNEL__

#include <linux/uio.h>

#include <asm/byteorder.h>

#include <linux/scatterlist.h>

#include <linux/smp_lock.h>

/*

 * Buffer adjustment

 */

#define XDR_QUADLEN(l)		(((l) + 3) >> 2)

/*

 * Generic opaque `network object.' At the kernel level, this type

 * is used only by lockd.

 */

#define XDR_MAX_NETOBJ		1024

struct xdr_netobj {

	unsigned int		len;

	u8 *			data;

};

/*

 * This is the generic XDR function. rqstp is either a rpc_rqst (client

 * side) or svc_rqst pointer (server side).

 * Encode functions always assume there's enough room in the buffer.

 */

typedef int	(*kxdrproc_t)(void *rqstp, __be32 *data, void *obj);

/*

 * Basic structure for transmission/reception of a client XDR message.

 * Features a header (for a linear buffer containing RPC headers

 * and the data payload for short messages), and then an array of

 * pages.

 * The tail iovec allows you to append data after the page array. Its

 * main interest is for appending padding to the pages in order to

 * satisfy the int_32-alignment requirements in RFC1832.

 *

 * For the future, we might want to string several of these together

 * in a list if anybody wants to make use of NFSv4 COMPOUND

 * operations and/or has a need for scatter/gather involving pages.

 */

struct xdr_buf {

	struct kvec	head[1],	/* RPC header + non-page data */

			tail[1];	/* Appended after page data */

	struct page **	pages;		/* Array of contiguous pages */

	unsigned int	page_base,	/* Start of page data */

			page_len,	/* Length of page data */

			flags;		/* Flags for data disposition */

#define XDRBUF_READ		0x01		/* target of file read */

#define XDRBUF_WRITE		0x02		/* source of file write */

	unsigned int	buflen,		/* Total length of storage buffer */

			len;		/* Length of XDR encoded message */

};

/*

 * pre-xdr'ed macros.

 */

#define	xdr_zero	__constant_htonl(0)

#define	xdr_one		__constant_htonl(1)

#define	xdr_two		__constant_htonl(2)

#define	rpc_success		__constant_htonl(RPC_SUCCESS)

#define	rpc_prog_unavail	__constant_htonl(RPC_PROG_UNAVAIL)

#define	rpc_prog_mismatch	__constant_htonl(RPC_PROG_MISMATCH)

#define	rpc_proc_unavail	__constant_htonl(RPC_PROC_UNAVAIL)

#define	rpc_garbage_args	__constant_htonl(RPC_GARBAGE_ARGS)

#define	rpc_system_err		__constant_htonl(RPC_SYSTEM_ERR)

#define	rpc_drop_reply		__constant_htonl(RPC_DROP_REPLY)

#define	rpc_auth_ok		__constant_htonl(RPC_AUTH_OK)

#define	rpc_autherr_badcred	__constant_htonl(RPC_AUTH_BADCRED)

#define	rpc_autherr_rejectedcred __constant_htonl(RPC_AUTH_REJECTEDCRED)

#define	rpc_autherr_badverf	__constant_htonl(RPC_AUTH_BADVERF)

#define	rpc_autherr_rejectedverf __constant_htonl(RPC_AUTH_REJECTEDVERF)

#define	rpc_autherr_tooweak	__constant_htonl(RPC_AUTH_TOOWEAK)

#define	rpcsec_gsserr_credproblem	__constant_htonl(RPCSEC_GSS_CREDPROBLEM)

#define	rpcsec_gsserr_ctxproblem	__constant_htonl(RPCSEC_GSS_CTXPROBLEM)

#define	rpc_autherr_oldseqnum	__constant_htonl(101)

/*

 * Miscellaneous XDR helper functions

 */

__be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int len);

__be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int len);

__be32 *xdr_encode_string(__be32 *p, const char *s);

__be32 *xdr_decode_string_inplace(__be32 *p, char **sp, unsigned int *lenp,

			unsigned int maxlen);

__be32 *xdr_encode_netobj(__be32 *p, const struct xdr_netobj *);

__be32 *xdr_decode_netobj(__be32 *p, struct xdr_netobj *);

void	xdr_encode_pages(struct xdr_buf *, struct page **, unsigned int,

			 unsigned int);

void	xdr_inline_pages(struct xdr_buf *, unsigned int,

			 struct page **, unsigned int, unsigned int);

static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len)

{

	return xdr_encode_opaque(p, s, len);

}

/*

 * Decode 64bit quantities (NFSv3 support)

 */

static inline __be32 *

xdr_encode_hyper(__be32 *p, __u64 val)

{

	*p++ = htonl(val >> 32);

	*p++ = htonl(val & 0xFFFFFFFF);

	return p;

}

static inline __be32 *

xdr_decode_hyper(__be32 *p, __u64 *valp)

{

	*valp  = ((__u64) ntohl(*p++)) << 32;

	*valp |= ntohl(*p++);

	return p;

}

/*

 * Adjust kvec to reflect end of xdr'ed data (RPC client XDR)

 */

static inline int

xdr_adjust_iovec(struct kvec *iov, __be32 *p)

{

	return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base);

}

/*

 * XDR buffer helper functions

 */

extern void xdr_shift_buf(struct xdr_buf *, size_t);

extern void xdr_buf_from_iov(struct kvec *, struct xdr_buf *);

extern int xdr_buf_subsegment(struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int);

extern int xdr_buf_read_netobj(struct xdr_buf *, struct xdr_netobj *, unsigned int);

extern int read_bytes_from_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);

extern int write_bytes_to_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);

/*

 * Helper structure for copying from an sk_buff.

 */

struct xdr_skb_reader {

	struct sk_buff	*skb;

	unsigned int	offset;

	size_t		count;

	__wsum		csum;

};

typedef size_t (*xdr_skb_read_actor)(struct xdr_skb_reader *desc, void *to, size_t len);

size_t xdr_skb_read_bits(struct xdr_skb_reader *desc, void *to, size_t len);

extern int csum_partial_copy_to_xdr(struct xdr_buf *, struct sk_buff *);

extern ssize_t xdr_partial_copy_from_skb(struct xdr_buf *, unsigned int,

		struct xdr_skb_reader *, xdr_skb_read_actor);

extern int xdr_encode_word(struct xdr_buf *, unsigned int, u32);

extern int xdr_decode_word(struct xdr_buf *, unsigned int, u32 *);

struct xdr_array2_desc;

typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem);

struct xdr_array2_desc {

	unsigned int elem_size;

	unsigned int array_len;

	unsigned int array_maxlen;

	xdr_xcode_elem_t xcode;

};

extern int xdr_decode_array2(struct xdr_buf *buf, unsigned int base,

                             struct xdr_array2_desc *desc);

extern int xdr_encode_array2(struct xdr_buf *buf, unsigned int base,

			     struct xdr_array2_desc *desc);

/*

 * Provide some simple tools for XDR buffer overflow-checking etc.

 */

struct xdr_stream {

	__be32 *p;		/* start of available buffer */

	struct xdr_buf *buf;	/* XDR buffer to read/write */

	__be32 *end;		/* end of available buffer space */

	struct kvec *iov;	/* pointer to the current kvec */

};

extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p);

extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes);

extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages,

		unsigned int base, unsigned int len);

extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p);

extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes);

extern void 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);

#endif /* __KERNEL__ */

#endif /* _SUNRPC_XDR_H_ */