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/*

 * 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>

/*

 * 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, u32 *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 iovec    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 */

        unsigned int    len;            /* Total length of data */

};

/*

 * 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_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

 */

u32 *   xdr_encode_array(u32 *p, const char *s, unsigned int len);

u32 *   xdr_encode_string(u32 *p, const char *s);

u32 *   xdr_decode_string(u32 *p, char **sp, int *lenp, int maxlen);

u32 *   xdr_decode_string_inplace(u32 *p, char **sp, int *lenp, int maxlen);

u32 *   xdr_encode_netobj(u32 *p, const struct xdr_netobj *);

u32 *   xdr_decode_netobj(u32 *p, struct xdr_netobj *);

u32 *   xdr_decode_netobj_fixed(u32 *p, void *obj, unsigned int len);

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);

/*

 * Decode 64bit quantities (NFSv3 support)

 */

static inline u32 *

xdr_encode_hyper(u32 *p, __u64 val)

{

        *p++ = htonl(val >> 32);

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

        return p;

}

static inline u32 *

xdr_decode_hyper(u32 *p, __u64 *valp)

{

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

        *valp |= ntohl(*p++);

        return p;

}

/*

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

 */

static inline int

xdr_adjust_iovec(struct iovec *iov, u32 *p)

{

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

}

void xdr_shift_iovec(struct iovec *, int, size_t);

/*

 * Maximum number of iov's we use.

 */

#define MAX_IOVEC       (12)

/*

 * XDR buffer helper functions

 */

extern int xdr_kmap(struct iovec *, struct xdr_buf *, size_t);

extern void xdr_kunmap(struct xdr_buf *, size_t);

extern void xdr_shift_buf(struct xdr_buf *, size_t);

/*

 * Helper structure for copying from an sk_buff.

 */

typedef struct {

        struct sk_buff  *skb;

        unsigned int    offset;

        size_t          count;

        unsigned int    csum;

} skb_reader_t;

typedef size_t (*skb_read_actor_t)(skb_reader_t *desc, void *to, size_t len);

extern void xdr_partial_copy_from_skb(struct xdr_buf *, unsigned int,

                skb_reader_t *, skb_read_actor_t);

struct socket;

struct sockaddr;

extern int xdr_sendpages(struct socket *, struct sockaddr *, int,

                struct xdr_buf *, unsigned int, int);

/*

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

 */

struct xdr_stream {

        uint32_t *p;            /* start of available buffer */

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

        uint32_t *end;          /* end of available buffer space */

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

};

/*

 * Initialize an xdr_stream for encoding data.

 *

 * Note: at the moment the RPC client only passes the length of our

 *       scratch buffer in the xdr_buf's header iovec. Previously this

 *       meant we needed to call xdr_adjust_iovec() after encoding the

 *       data. With the new scheme, the xdr_stream manages the details

 *       of the buffer length, and takes care of adjusting the iovec

 *       length for us.

 */

static inline void

xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, uint32_t *p)

{

        struct iovec *iov = buf->head;

        xdr->buf = buf;

        xdr->iov = iov;

        xdr->end = (uint32_t *)((char *)iov->iov_base + iov->iov_len);

        buf->len = iov->iov_len = (char *)p - (char *)iov->iov_base;

        xdr->p = p;

}

/*

 * Check that we have enough buffer space to encode 'nbytes' more

 * bytes of data. If so, update the total xdr_buf length, and

 * adjust the length of the current iovec.

 */

static inline uint32_t *

xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes)

{

        uint32_t *p = xdr->p;

        uint32_t *q;

        /* align nbytes on the next 32-bit boundary */

        nbytes += 3;

        nbytes &= ~3;

        q = p + (nbytes >> 2);

        if (unlikely(q > xdr->end || q < p))

                return NULL;

        xdr->p = q;

        xdr->iov->iov_len += nbytes;

        xdr->buf->len += nbytes;

        return p;

}

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

                unsigned int base, unsigned int len);

extern void xdr_read_pages(struct xdr_stream *xdr, unsigned int len);

/*

 * Initialize an xdr_stream for decoding data.

 */

static inline void

xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, uint32_t *p)

{

        struct iovec *iov = buf->head;

        xdr->buf = buf;

        xdr->iov = iov;

        xdr->p = p;

        xdr->end = (uint32_t *)((char *)iov->iov_base + iov->iov_len);

}

/*

 * Check if the input buffer is long enough to enable us to decode

 * 'nbytes' more bytes of data starting at the current position.

 * If so return the current pointer, then update the current

 * position.

 */

static inline uint32_t *

xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes)

{

        uint32_t *p = xdr->p;

        uint32_t *q = p + XDR_QUADLEN(nbytes);

        if (unlikely(q > xdr->end || q < p))

                return NULL;

        xdr->p = q;

        return p;

}

#endif /* __KERNEL__ */

#endif /* _SUNRPC_XDR_H_ */