LXR linux/include/linux/sunrpc/xdr.h

   1/*
   2 * XDR standard data types and function declarations
   3 *
   4 * Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>
   5 *
   6 * Based on:
   7 *   RFC 4506 "XDR: External Data Representation Standard", May 2006
   8 */
   9
  10#ifndef _SUNRPC_XDR_H_
  11#define _SUNRPC_XDR_H_
  12
  13#ifdef __KERNEL__
  14
  15#include <linux/uio.h>
  16#include <asm/byteorder.h>
  17#include <asm/unaligned.h>
  18#include <linux/scatterlist.h>
  19
  20/*
  21 * Buffer adjustment
  22 */
  23#define XDR_QUADLEN(l)          (((l) + 3) >> 2)
  24
  25/*
  26 * Generic opaque `network object.' At the kernel level, this type
  27 * is used only by lockd.
  28 */
  29#define XDR_MAX_NETOBJ          1024
  30struct xdr_netobj {
  31        unsigned int            len;
  32        u8 *                    data;
  33};
  34
  35/*
  36 * This is the legacy generic XDR function. rqstp is either a rpc_rqst
  37 * (client side) or svc_rqst pointer (server side).
  38 * Encode functions always assume there's enough room in the buffer.
  39 */
  40typedef int     (*kxdrproc_t)(void *rqstp, __be32 *data, void *obj);
  41
  42/*
  43 * Basic structure for transmission/reception of a client XDR message.
  44 * Features a header (for a linear buffer containing RPC headers
  45 * and the data payload for short messages), and then an array of
  46 * pages.
  47 * The tail iovec allows you to append data after the page array. Its
  48 * main interest is for appending padding to the pages in order to
  49 * satisfy the int_32-alignment requirements in RFC1832.
  50 *
  51 * For the future, we might want to string several of these together
  52 * in a list if anybody wants to make use of NFSv4 COMPOUND
  53 * operations and/or has a need for scatter/gather involving pages.
  54 */
  55struct xdr_buf {
  56        struct kvec     head[1],        /* RPC header + non-page data */
  57                        tail[1];        /* Appended after page data */
  58
  59        struct page **  pages;          /* Array of contiguous pages */
  60        unsigned int    page_base,      /* Start of page data */
  61                        page_len,       /* Length of page data */
  62                        flags;          /* Flags for data disposition */
  63#define XDRBUF_READ             0x01            /* target of file read */
  64#define XDRBUF_WRITE            0x02            /* source of file write */
  65
  66        unsigned int    buflen,         /* Total length of storage buffer */
  67                        len;            /* Length of XDR encoded message */
  68};
  69
  70/*
  71 * pre-xdr'ed macros.
  72 */
  73
  74#define xdr_zero        cpu_to_be32(0)
  75#define xdr_one         cpu_to_be32(1)
  76#define xdr_two         cpu_to_be32(2)
  77
  78#define rpc_success             cpu_to_be32(RPC_SUCCESS)
  79#define rpc_prog_unavail        cpu_to_be32(RPC_PROG_UNAVAIL)
  80#define rpc_prog_mismatch       cpu_to_be32(RPC_PROG_MISMATCH)
  81#define rpc_proc_unavail        cpu_to_be32(RPC_PROC_UNAVAIL)
  82#define rpc_garbage_args        cpu_to_be32(RPC_GARBAGE_ARGS)
  83#define rpc_system_err          cpu_to_be32(RPC_SYSTEM_ERR)
  84#define rpc_drop_reply          cpu_to_be32(RPC_DROP_REPLY)
  85
  86#define rpc_auth_ok             cpu_to_be32(RPC_AUTH_OK)
  87#define rpc_autherr_badcred     cpu_to_be32(RPC_AUTH_BADCRED)
  88#define rpc_autherr_rejectedcred cpu_to_be32(RPC_AUTH_REJECTEDCRED)
  89#define rpc_autherr_badverf     cpu_to_be32(RPC_AUTH_BADVERF)
  90#define rpc_autherr_rejectedverf cpu_to_be32(RPC_AUTH_REJECTEDVERF)
  91#define rpc_autherr_tooweak     cpu_to_be32(RPC_AUTH_TOOWEAK)
  92#define rpcsec_gsserr_credproblem       cpu_to_be32(RPCSEC_GSS_CREDPROBLEM)
  93#define rpcsec_gsserr_ctxproblem        cpu_to_be32(RPCSEC_GSS_CTXPROBLEM)
  94#define rpc_autherr_oldseqnum   cpu_to_be32(101)
  95
  96/*
  97 * Miscellaneous XDR helper functions
  98 */
  99__be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int len);
 100__be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int len);
 101__be32 *xdr_encode_string(__be32 *p, const char *s);
 102__be32 *xdr_decode_string_inplace(__be32 *p, char **sp, unsigned int *lenp,
 103                        unsigned int maxlen);
 104__be32 *xdr_encode_netobj(__be32 *p, const struct xdr_netobj *);
 105__be32 *xdr_decode_netobj(__be32 *p, struct xdr_netobj *);
 106
 107void    xdr_inline_pages(struct xdr_buf *, unsigned int,
 108                         struct page **, unsigned int, unsigned int);
 109void    xdr_terminate_string(struct xdr_buf *, const u32);
 110
 111static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len)
 112{
 113        return xdr_encode_opaque(p, s, len);
 114}
 115
 116/*
 117 * Decode 64bit quantities (NFSv3 support)
 118 */
 119static inline __be32 *
 120xdr_encode_hyper(__be32 *p, __u64 val)
 121{
 122        put_unaligned_be64(val, p);
 123        return p + 2;
 124}
 125
 126static inline __be32 *
 127xdr_decode_hyper(__be32 *p, __u64 *valp)
 128{
 129        *valp = get_unaligned_be64(p);
 130        return p + 2;
 131}
 132
 133static inline __be32 *
 134xdr_decode_opaque_fixed(__be32 *p, void *ptr, unsigned int len)
 135{
 136        memcpy(ptr, p, len);
 137        return p + XDR_QUADLEN(len);
 138}
 139
 140/*
 141 * Adjust kvec to reflect end of xdr'ed data (RPC client XDR)
 142 */
 143static inline int
 144xdr_adjust_iovec(struct kvec *iov, __be32 *p)
 145{
 146        return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base);
 147}
 148
 149/*
 150 * XDR buffer helper functions
 151 */
 152extern void xdr_shift_buf(struct xdr_buf *, size_t);
 153extern void xdr_buf_from_iov(struct kvec *, struct xdr_buf *);
 154extern int xdr_buf_subsegment(struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int);
 155extern int xdr_buf_read_netobj(struct xdr_buf *, struct xdr_netobj *, unsigned int);
 156extern int read_bytes_from_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
 157extern int write_bytes_to_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
 158
 159/*
 160 * Helper structure for copying from an sk_buff.
 161 */
 162struct xdr_skb_reader {
 163        struct sk_buff  *skb;
 164        unsigned int    offset;
 165        size_t          count;
 166        __wsum          csum;
 167};
 168
 169typedef size_t (*xdr_skb_read_actor)(struct xdr_skb_reader *desc, void *to, size_t len);
 170
 171size_t xdr_skb_read_bits(struct xdr_skb_reader *desc, void *to, size_t len);
 172extern int csum_partial_copy_to_xdr(struct xdr_buf *, struct sk_buff *);
 173extern ssize_t xdr_partial_copy_from_skb(struct xdr_buf *, unsigned int,
 174                struct xdr_skb_reader *, xdr_skb_read_actor);
 175
 176extern int xdr_encode_word(struct xdr_buf *, unsigned int, u32);
 177extern int xdr_decode_word(struct xdr_buf *, unsigned int, u32 *);
 178
 179struct xdr_array2_desc;
 180typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem);
 181struct xdr_array2_desc {
 182        unsigned int elem_size;
 183        unsigned int array_len;
 184        unsigned int array_maxlen;
 185        xdr_xcode_elem_t xcode;
 186};
 187
 188extern int xdr_decode_array2(struct xdr_buf *buf, unsigned int base,
 189                             struct xdr_array2_desc *desc);
 190extern int xdr_encode_array2(struct xdr_buf *buf, unsigned int base,
 191                             struct xdr_array2_desc *desc);
 192extern void _copy_from_pages(char *p, struct page **pages, size_t pgbase,
 193                             size_t len);
 194
 195/*
 196 * Provide some simple tools for XDR buffer overflow-checking etc.
 197 */
 198struct xdr_stream {
 199        __be32 *p;              /* start of available buffer */
 200        struct xdr_buf *buf;    /* XDR buffer to read/write */
 201
 202        __be32 *end;            /* end of available buffer space */
 203        struct kvec *iov;       /* pointer to the current kvec */
 204        struct kvec scratch;    /* Scratch buffer */
 205        struct page **page_ptr; /* pointer to the current page */
 206        unsigned int nwords;    /* Remaining decode buffer length */
 207};
 208
 209/*
 210 * These are the xdr_stream style generic XDR encode and decode functions.
 211 */
 212typedef void    (*kxdreproc_t)(void *rqstp, struct xdr_stream *xdr, void *obj);
 213typedef int     (*kxdrdproc_t)(void *rqstp, struct xdr_stream *xdr, void *obj);
 214
 215extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p);
 216extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes);
 217extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages,
 218                unsigned int base, unsigned int len);
 219extern unsigned int xdr_stream_pos(const struct xdr_stream *xdr);
 220extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p);
 221extern void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf,
 222                struct page **pages, unsigned int len);
 223extern void xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen);
 224extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes);
 225extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len);
 226extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);
 227extern int xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);
 228
 229#endif /* __KERNEL__ */
 230
 231#endif /* _SUNRPC_XDR_H_ */
 232