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 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
  70static inline void
  71xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
  72{
  73        buf->head[0].iov_base = start;
  74        buf->head[0].iov_len = len;
  75        buf->tail[0].iov_len = 0;
  76        buf->page_len = 0;
  77        buf->flags = 0;
  78        buf->len = 0;
  79        buf->buflen = len;
  80}
  81
  82/*
  83 * pre-xdr'ed macros.
  84 */
  85
  86#define xdr_zero        cpu_to_be32(0)
  87#define xdr_one         cpu_to_be32(1)
  88#define xdr_two         cpu_to_be32(2)
  89
  90#define rpc_success             cpu_to_be32(RPC_SUCCESS)
  91#define rpc_prog_unavail        cpu_to_be32(RPC_PROG_UNAVAIL)
  92#define rpc_prog_mismatch       cpu_to_be32(RPC_PROG_MISMATCH)
  93#define rpc_proc_unavail        cpu_to_be32(RPC_PROC_UNAVAIL)
  94#define rpc_garbage_args        cpu_to_be32(RPC_GARBAGE_ARGS)
  95#define rpc_system_err          cpu_to_be32(RPC_SYSTEM_ERR)
  96#define rpc_drop_reply          cpu_to_be32(RPC_DROP_REPLY)
  97
  98#define rpc_auth_ok             cpu_to_be32(RPC_AUTH_OK)
  99#define rpc_autherr_badcred     cpu_to_be32(RPC_AUTH_BADCRED)
 100#define rpc_autherr_rejectedcred cpu_to_be32(RPC_AUTH_REJECTEDCRED)
 101#define rpc_autherr_badverf     cpu_to_be32(RPC_AUTH_BADVERF)
 102#define rpc_autherr_rejectedverf cpu_to_be32(RPC_AUTH_REJECTEDVERF)
 103#define rpc_autherr_tooweak     cpu_to_be32(RPC_AUTH_TOOWEAK)
 104#define rpcsec_gsserr_credproblem       cpu_to_be32(RPCSEC_GSS_CREDPROBLEM)
 105#define rpcsec_gsserr_ctxproblem        cpu_to_be32(RPCSEC_GSS_CTXPROBLEM)
 106#define rpc_autherr_oldseqnum   cpu_to_be32(101)
 107
 108/*
 109 * Miscellaneous XDR helper functions
 110 */
 111__be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int len);
 112__be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int len);
 113__be32 *xdr_encode_string(__be32 *p, const char *s);
 114__be32 *xdr_decode_string_inplace(__be32 *p, char **sp, unsigned int *lenp,
 115                        unsigned int maxlen);
 116__be32 *xdr_encode_netobj(__be32 *p, const struct xdr_netobj *);
 117__be32 *xdr_decode_netobj(__be32 *p, struct xdr_netobj *);
 118
 119void    xdr_inline_pages(struct xdr_buf *, unsigned int,
 120                         struct page **, unsigned int, unsigned int);
 121void    xdr_terminate_string(struct xdr_buf *, const u32);
 122
 123static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len)
 124{
 125        return xdr_encode_opaque(p, s, len);
 126}
 127
 128/*
 129 * Decode 64bit quantities (NFSv3 support)
 130 */
 131static inline __be32 *
 132xdr_encode_hyper(__be32 *p, __u64 val)
 133{
 134        put_unaligned_be64(val, p);
 135        return p + 2;
 136}
 137
 138static inline __be32 *
 139xdr_decode_hyper(__be32 *p, __u64 *valp)
 140{
 141        *valp = get_unaligned_be64(p);
 142        return p + 2;
 143}
 144
 145static inline __be32 *
 146xdr_decode_opaque_fixed(__be32 *p, void *ptr, unsigned int len)
 147{
 148        memcpy(ptr, p, len);
 149        return p + XDR_QUADLEN(len);
 150}
 151
 152/*
 153 * Adjust kvec to reflect end of xdr'ed data (RPC client XDR)
 154 */
 155static inline int
 156xdr_adjust_iovec(struct kvec *iov, __be32 *p)
 157{
 158        return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base);
 159}
 160
 161/*
 162 * XDR buffer helper functions
 163 */
 164extern void xdr_shift_buf(struct xdr_buf *, size_t);
 165extern void xdr_buf_from_iov(struct kvec *, struct xdr_buf *);
 166extern int xdr_buf_subsegment(struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int);
 167extern void xdr_buf_trim(struct xdr_buf *, unsigned int);
 168extern int xdr_buf_read_netobj(struct xdr_buf *, struct xdr_netobj *, unsigned int);
 169extern int read_bytes_from_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
 170extern int write_bytes_to_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
 171
 172/*
 173 * Helper structure for copying from an sk_buff.
 174 */
 175struct xdr_skb_reader {
 176        struct sk_buff  *skb;
 177        unsigned int    offset;
 178        size_t          count;
 179        __wsum          csum;
 180};
 181
 182typedef size_t (*xdr_skb_read_actor)(struct xdr_skb_reader *desc, void *to, size_t len);
 183
 184size_t xdr_skb_read_bits(struct xdr_skb_reader *desc, void *to, size_t len);
 185extern int csum_partial_copy_to_xdr(struct xdr_buf *, struct sk_buff *);
 186extern ssize_t xdr_partial_copy_from_skb(struct xdr_buf *, unsigned int,
 187                struct xdr_skb_reader *, xdr_skb_read_actor);
 188
 189extern int xdr_encode_word(struct xdr_buf *, unsigned int, u32);
 190extern int xdr_decode_word(struct xdr_buf *, unsigned int, u32 *);
 191
 192struct xdr_array2_desc;
 193typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem);
 194struct xdr_array2_desc {
 195        unsigned int elem_size;
 196        unsigned int array_len;
 197        unsigned int array_maxlen;
 198        xdr_xcode_elem_t xcode;
 199};
 200
 201extern int xdr_decode_array2(struct xdr_buf *buf, unsigned int base,
 202                             struct xdr_array2_desc *desc);
 203extern int xdr_encode_array2(struct xdr_buf *buf, unsigned int base,
 204                             struct xdr_array2_desc *desc);
 205extern void _copy_from_pages(char *p, struct page **pages, size_t pgbase,
 206                             size_t len);
 207
 208/*
 209 * Provide some simple tools for XDR buffer overflow-checking etc.
 210 */
 211struct xdr_stream {
 212        __be32 *p;              /* start of available buffer */
 213        struct xdr_buf *buf;    /* XDR buffer to read/write */
 214
 215        __be32 *end;            /* end of available buffer space */
 216        struct kvec *iov;       /* pointer to the current kvec */
 217        struct kvec scratch;    /* Scratch buffer */
 218        struct page **page_ptr; /* pointer to the current page */
 219        unsigned int nwords;    /* Remaining decode buffer length */
 220};
 221
 222/*
 223 * These are the xdr_stream style generic XDR encode and decode functions.
 224 */
 225typedef void    (*kxdreproc_t)(void *rqstp, struct xdr_stream *xdr, void *obj);
 226typedef int     (*kxdrdproc_t)(void *rqstp, struct xdr_stream *xdr, void *obj);
 227
 228extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p);
 229extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes);
 230extern void xdr_commit_encode(struct xdr_stream *xdr);
 231extern void xdr_truncate_encode(struct xdr_stream *xdr, size_t len);
 232extern int xdr_restrict_buflen(struct xdr_stream *xdr, int newbuflen);
 233extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages,
 234                unsigned int base, unsigned int len);
 235extern unsigned int xdr_stream_pos(const struct xdr_stream *xdr);
 236extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p);
 237extern void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf,
 238                struct page **pages, unsigned int len);
 239extern void xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen);
 240extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes);
 241extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len);
 242extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);
 243extern int xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);
 244
 245#endif /* __KERNEL__ */
 246
 247#endif /* _SUNRPC_XDR_H_ */
 248