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
  30 struct 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  */
  40 typedef 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  */
  55 struct 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
  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
 107 void    xdr_inline_pages(struct xdr_buf *, unsigned int,
 108                          struct page **, unsigned int, unsigned int);
 109 void    xdr_terminate_string(struct xdr_buf *, const u32);
 110
 111 static 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  */
 119 static inline __be32 *
 120 xdr_encode_hyper(__be32 *p, __u64 val)
 121 {
 122         put_unaligned_be64(val, p);
 123         return p + 2;
 124 }
 125
 126 static inline __be32 *
 127 xdr_decode_hyper(__be32 *p, __u64 *valp)
 128 {
 129         *valp = get_unaligned_be64(p);
 130         return p + 2;
 131 }
 132
 133 static inline __be32 *
 134 xdr_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  */
 143 static inline int
 144 xdr_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  */
 152 extern void xdr_shift_buf(struct xdr_buf *, size_t);
 153 extern void xdr_buf_from_iov(struct kvec *, struct xdr_buf *);
 154 extern int xdr_buf_subsegment(struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int);
 155 extern void xdr_buf_trim(struct xdr_buf *, unsigned int);
 156 extern int xdr_buf_read_netobj(struct xdr_buf *, struct xdr_netobj *, unsigned int);
 157 extern int read_bytes_from_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
 158 extern int write_bytes_to_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
 159
 160 /*
 161  * Helper structure for copying from an sk_buff.
 162  */
 163 struct xdr_skb_reader {
 164         struct sk_buff  *skb;
 165         unsigned int    offset;
 166         size_t          count;
 167         __wsum          csum;
 168 };
 169
 170 typedef size_t (*xdr_skb_read_actor)(struct xdr_skb_reader *desc, void *to, size_t len);
 171
 172 size_t xdr_skb_read_bits(struct xdr_skb_reader *desc, void *to, size_t len);
 173 extern int csum_partial_copy_to_xdr(struct xdr_buf *, struct sk_buff *);
 174 extern ssize_t xdr_partial_copy_from_skb(struct xdr_buf *, unsigned int,
 175                 struct xdr_skb_reader *, xdr_skb_read_actor);
 176
 177 extern int xdr_encode_word(struct xdr_buf *, unsigned int, u32);
 178 extern int xdr_decode_word(struct xdr_buf *, unsigned int, u32 *);
 179
 180 struct xdr_array2_desc;
 181 typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem);
 182 struct xdr_array2_desc {
 183         unsigned int elem_size;
 184         unsigned int array_len;
 185         unsigned int array_maxlen;
 186         xdr_xcode_elem_t xcode;
 187 };
 188
 189 extern int xdr_decode_array2(struct xdr_buf *buf, unsigned int base,
 190                              struct xdr_array2_desc *desc);
 191 extern int xdr_encode_array2(struct xdr_buf *buf, unsigned int base,
 192                              struct xdr_array2_desc *desc);
 193 extern void _copy_from_pages(char *p, struct page **pages, size_t pgbase,
 194                              size_t len);
 195
 196 /*
 197  * Provide some simple tools for XDR buffer overflow-checking etc.
 198  */
 199 struct xdr_stream {
 200         __be32 *p;              /* start of available buffer */
 201         struct xdr_buf *buf;    /* XDR buffer to read/write */
 202
 203         __be32 *end;            /* end of available buffer space */
 204         struct kvec *iov;       /* pointer to the current kvec */
 205         struct kvec scratch;    /* Scratch buffer */
 206         struct page **page_ptr; /* pointer to the current page */
 207         unsigned int nwords;    /* Remaining decode buffer length */
 208 };
 209
 210 /*
 211  * These are the xdr_stream style generic XDR encode and decode functions.
 212  */
 213 typedef void    (*kxdreproc_t)(void *rqstp, struct xdr_stream *xdr, void *obj);
 214 typedef int     (*kxdrdproc_t)(void *rqstp, struct xdr_stream *xdr, void *obj);
 215
 216 extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p);
 217 extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes);
 218 extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages,
 219                 unsigned int base, unsigned int len);
 220 extern unsigned int xdr_stream_pos(const struct xdr_stream *xdr);
 221 extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p);
 222 extern void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf,
 223                 struct page **pages, unsigned int len);
 224 extern void xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen);
 225 extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes);
 226 extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len);
 227 extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);
 228 extern int xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);
 229
 230 #endif /* __KERNEL__ */
 231
 232 #endif /* _SUNRPC_XDR_H_ */