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 generic XDR function. rqstp is either a rpc_rqst (client
  37  * 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 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
 107 void    xdr_encode_pages(struct xdr_buf *, struct page **, unsigned int,
 108                          unsigned int);
 109 void    xdr_inline_pages(struct xdr_buf *, unsigned int,
 110                          struct page **, unsigned int, unsigned int);
 111 void    xdr_terminate_string(struct xdr_buf *, const u32);
 112
 113 static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len)
 114 {
 115         return xdr_encode_opaque(p, s, len);
 116 }
 117
 118 /*
 119  * Decode 64bit quantities (NFSv3 support)
 120  */
 121 static inline __be32 *
 122 xdr_encode_hyper(__be32 *p, __u64 val)
 123 {
 124         put_unaligned_be64(val, p);
 125         return p + 2;
 126 }
 127
 128 static inline __be32 *
 129 xdr_decode_hyper(__be32 *p, __u64 *valp)
 130 {
 131         *valp = get_unaligned_be64(p);
 132         return p + 2;
 133 }
 134
 135 static inline __be32 *
 136 xdr_decode_opaque_fixed(__be32 *p, void *ptr, unsigned int len)
 137 {
 138         memcpy(ptr, p, len);
 139         return p + XDR_QUADLEN(len);
 140 }
 141
 142 /*
 143  * Adjust kvec to reflect end of xdr'ed data (RPC client XDR)
 144  */
 145 static inline int
 146 xdr_adjust_iovec(struct kvec *iov, __be32 *p)
 147 {
 148         return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base);
 149 }
 150
 151 /*
 152  * XDR buffer helper functions
 153  */
 154 extern void xdr_shift_buf(struct xdr_buf *, size_t);
 155 extern void xdr_buf_from_iov(struct kvec *, struct xdr_buf *);
 156 extern int xdr_buf_subsegment(struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int);
 157 extern int xdr_buf_read_netobj(struct xdr_buf *, struct xdr_netobj *, unsigned int);
 158 extern int read_bytes_from_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
 159 extern int write_bytes_to_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
 160
 161 /*
 162  * Helper structure for copying from an sk_buff.
 163  */
 164 struct xdr_skb_reader {
 165         struct sk_buff  *skb;
 166         unsigned int    offset;
 167         size_t          count;
 168         __wsum          csum;
 169 };
 170
 171 typedef size_t (*xdr_skb_read_actor)(struct xdr_skb_reader *desc, void *to, size_t len);
 172
 173 size_t xdr_skb_read_bits(struct xdr_skb_reader *desc, void *to, size_t len);
 174 extern int csum_partial_copy_to_xdr(struct xdr_buf *, struct sk_buff *);
 175 extern ssize_t xdr_partial_copy_from_skb(struct xdr_buf *, unsigned int,
 176                 struct xdr_skb_reader *, xdr_skb_read_actor);
 177
 178 extern int xdr_encode_word(struct xdr_buf *, unsigned int, u32);
 179 extern int xdr_decode_word(struct xdr_buf *, unsigned int, u32 *);
 180
 181 struct xdr_array2_desc;
 182 typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem);
 183 struct xdr_array2_desc {
 184         unsigned int elem_size;
 185         unsigned int array_len;
 186         unsigned int array_maxlen;
 187         xdr_xcode_elem_t xcode;
 188 };
 189
 190 extern int xdr_decode_array2(struct xdr_buf *buf, unsigned int base,
 191                              struct xdr_array2_desc *desc);
 192 extern int xdr_encode_array2(struct xdr_buf *buf, unsigned int base,
 193                              struct xdr_array2_desc *desc);
 194
 195 /*
 196  * Provide some simple tools for XDR buffer overflow-checking etc.
 197  */
 198 struct 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 };
 207
 208 extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p);
 209 extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes);
 210 extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages,
 211                 unsigned int base, unsigned int len);
 212 extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p);
 213 extern void xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen);
 214 extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes);
 215 extern void xdr_read_pages(struct xdr_stream *xdr, unsigned int len);
 216 extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);
 217 extern int xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);
 218
 219 #endif /* __KERNEL__ */
 220
 221 #endif /* _SUNRPC_XDR_H_ */