include/linux/sunrpc/xdr.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * XDR standard data types and function declarations
   4  *
   5  * Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>
   6  *
   7  * Based on:
   8  *   RFC 4506 "XDR: External Data Representation Standard", May 2006
   9  */
  10
  11 #ifndef _SUNRPC_XDR_H_
  12 #define _SUNRPC_XDR_H_
  13
  14 #ifdef __KERNEL__
  15
  16 #include <linux/uio.h>
  17 #include <asm/byteorder.h>
  18 #include <asm/unaligned.h>
  19 #include <linux/scatterlist.h>
  20
  21 struct bio_vec;
  22 struct rpc_rqst;
  23
  24 /*
  25  * Buffer adjustment
  26  */
  27 #define XDR_QUADLEN(l)          (((l) + 3) >> 2)
  28
  29 /*
  30  * Generic opaque `network object.' At the kernel level, this type
  31  * is used only by lockd.
  32  */
  33 #define XDR_MAX_NETOBJ          1024
  34 struct xdr_netobj {
  35         unsigned int            len;
  36         u8 *                    data;
  37 };
  38
  39 /*
  40  * Basic structure for transmission/reception of a client XDR message.
  41  * Features a header (for a linear buffer containing RPC headers
  42  * and the data payload for short messages), and then an array of
  43  * pages.
  44  * The tail iovec allows you to append data after the page array. Its
  45  * main interest is for appending padding to the pages in order to
  46  * satisfy the int_32-alignment requirements in RFC1832.
  47  *
  48  * For the future, we might want to string several of these together
  49  * in a list if anybody wants to make use of NFSv4 COMPOUND
  50  * operations and/or has a need for scatter/gather involving pages.
  51  */
  52 struct xdr_buf {
  53         struct kvec     head[1],        /* RPC header + non-page data */
  54                         tail[1];        /* Appended after page data */
  55
  56         struct bio_vec  *bvec;
  57         struct page **  pages;          /* Array of pages */
  58         unsigned int    page_base,      /* Start of page data */
  59                         page_len,       /* Length of page data */
  60                         flags;          /* Flags for data disposition */
  61 #define XDRBUF_READ             0x01            /* target of file read */
  62 #define XDRBUF_WRITE            0x02            /* source of file write */
  63 #define XDRBUF_SPARSE_PAGES     0x04            /* Page array is sparse */
  64
  65         unsigned int    buflen,         /* Total length of storage buffer */
  66                         len;            /* Length of XDR encoded message */
  67 };
  68
  69 static inline void
  70 xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
  71 {
  72         buf->head[0].iov_base = start;
  73         buf->head[0].iov_len = len;
  74         buf->tail[0].iov_len = 0;
  75         buf->pages = NULL;
  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_auth_null   cpu_to_be32(RPC_AUTH_NULL)
  91 #define rpc_auth_unix   cpu_to_be32(RPC_AUTH_UNIX)
  92 #define rpc_auth_short  cpu_to_be32(RPC_AUTH_SHORT)
  93 #define rpc_auth_gss    cpu_to_be32(RPC_AUTH_GSS)
  94
  95 #define rpc_call        cpu_to_be32(RPC_CALL)
  96 #define rpc_reply       cpu_to_be32(RPC_REPLY)
  97
  98 #define rpc_msg_accepted        cpu_to_be32(RPC_MSG_ACCEPTED)
  99
 100 #define rpc_success             cpu_to_be32(RPC_SUCCESS)
 101 #define rpc_prog_unavail        cpu_to_be32(RPC_PROG_UNAVAIL)
 102 #define rpc_prog_mismatch       cpu_to_be32(RPC_PROG_MISMATCH)
 103 #define rpc_proc_unavail        cpu_to_be32(RPC_PROC_UNAVAIL)
 104 #define rpc_garbage_args        cpu_to_be32(RPC_GARBAGE_ARGS)
 105 #define rpc_system_err          cpu_to_be32(RPC_SYSTEM_ERR)
 106 #define rpc_drop_reply          cpu_to_be32(RPC_DROP_REPLY)
 107
 108 #define rpc_mismatch            cpu_to_be32(RPC_MISMATCH)
 109 #define rpc_auth_error          cpu_to_be32(RPC_AUTH_ERROR)
 110
 111 #define rpc_auth_ok             cpu_to_be32(RPC_AUTH_OK)
 112 #define rpc_autherr_badcred     cpu_to_be32(RPC_AUTH_BADCRED)
 113 #define rpc_autherr_rejectedcred cpu_to_be32(RPC_AUTH_REJECTEDCRED)
 114 #define rpc_autherr_badverf     cpu_to_be32(RPC_AUTH_BADVERF)
 115 #define rpc_autherr_rejectedverf cpu_to_be32(RPC_AUTH_REJECTEDVERF)
 116 #define rpc_autherr_tooweak     cpu_to_be32(RPC_AUTH_TOOWEAK)
 117 #define rpcsec_gsserr_credproblem       cpu_to_be32(RPCSEC_GSS_CREDPROBLEM)
 118 #define rpcsec_gsserr_ctxproblem        cpu_to_be32(RPCSEC_GSS_CTXPROBLEM)
 119
 120 /*
 121  * Miscellaneous XDR helper functions
 122  */
 123 __be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int len);
 124 __be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int len);
 125 __be32 *xdr_encode_string(__be32 *p, const char *s);
 126 __be32 *xdr_decode_string_inplace(__be32 *p, char **sp, unsigned int *lenp,
 127                         unsigned int maxlen);
 128 __be32 *xdr_encode_netobj(__be32 *p, const struct xdr_netobj *);
 129 __be32 *xdr_decode_netobj(__be32 *p, struct xdr_netobj *);
 130
 131 void    xdr_inline_pages(struct xdr_buf *, unsigned int,
 132                          struct page **, unsigned int, unsigned int);
 133 void    xdr_terminate_string(struct xdr_buf *, const u32);
 134 size_t  xdr_buf_pagecount(struct xdr_buf *buf);
 135 int     xdr_alloc_bvec(struct xdr_buf *buf, gfp_t gfp);
 136 void    xdr_free_bvec(struct xdr_buf *buf);
 137
 138 static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len)
 139 {
 140         return xdr_encode_opaque(p, s, len);
 141 }
 142
 143 /*
 144  * Decode 64bit quantities (NFSv3 support)
 145  */
 146 static inline __be32 *
 147 xdr_encode_hyper(__be32 *p, __u64 val)
 148 {
 149         put_unaligned_be64(val, p);
 150         return p + 2;
 151 }
 152
 153 static inline __be32 *
 154 xdr_decode_hyper(__be32 *p, __u64 *valp)
 155 {
 156         *valp = get_unaligned_be64(p);
 157         return p + 2;
 158 }
 159
 160 static inline __be32 *
 161 xdr_decode_opaque_fixed(__be32 *p, void *ptr, unsigned int len)
 162 {
 163         memcpy(ptr, p, len);
 164         return p + XDR_QUADLEN(len);
 165 }
 166
 167 /*
 168  * Adjust kvec to reflect end of xdr'ed data (RPC client XDR)
 169  */
 170 static inline int
 171 xdr_adjust_iovec(struct kvec *iov, __be32 *p)
 172 {
 173         return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base);
 174 }
 175
 176 /*
 177  * XDR buffer helper functions
 178  */
 179 extern void xdr_shift_buf(struct xdr_buf *, size_t);
 180 extern void xdr_buf_from_iov(struct kvec *, struct xdr_buf *);
 181 extern int xdr_buf_subsegment(struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int);
 182 extern int xdr_buf_read_netobj(struct xdr_buf *, struct xdr_netobj *, unsigned int);
 183 extern int read_bytes_from_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
 184 extern int write_bytes_to_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
 185
 186 /*
 187  * Helper structure for copying from an sk_buff.
 188  */
 189 struct xdr_skb_reader {
 190         struct sk_buff  *skb;
 191         unsigned int    offset;
 192         size_t          count;
 193         __wsum          csum;
 194 };
 195
 196 typedef size_t (*xdr_skb_read_actor)(struct xdr_skb_reader *desc, void *to, size_t len);
 197
 198 extern int csum_partial_copy_to_xdr(struct xdr_buf *, struct sk_buff *);
 199
 200 extern int xdr_encode_word(struct xdr_buf *, unsigned int, u32);
 201 extern int xdr_decode_word(struct xdr_buf *, unsigned int, u32 *);
 202
 203 struct xdr_array2_desc;
 204 typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem);
 205 struct xdr_array2_desc {
 206         unsigned int elem_size;
 207         unsigned int array_len;
 208         unsigned int array_maxlen;
 209         xdr_xcode_elem_t xcode;
 210 };
 211
 212 extern int xdr_decode_array2(struct xdr_buf *buf, unsigned int base,
 213                              struct xdr_array2_desc *desc);
 214 extern int xdr_encode_array2(struct xdr_buf *buf, unsigned int base,
 215                              struct xdr_array2_desc *desc);
 216 extern void _copy_from_pages(char *p, struct page **pages, size_t pgbase,
 217                              size_t len);
 218
 219 /*
 220  * Provide some simple tools for XDR buffer overflow-checking etc.
 221  */
 222 struct xdr_stream {
 223         __be32 *p;              /* start of available buffer */
 224         struct xdr_buf *buf;    /* XDR buffer to read/write */
 225
 226         __be32 *end;            /* end of available buffer space */
 227         struct kvec *iov;       /* pointer to the current kvec */
 228         struct kvec scratch;    /* Scratch buffer */
 229         struct page **page_ptr; /* pointer to the current page */
 230         unsigned int nwords;    /* Remaining decode buffer length */
 231
 232         struct rpc_rqst *rqst;  /* For debugging */
 233 };
 234
 235 /*
 236  * These are the xdr_stream style generic XDR encode and decode functions.
 237  */
 238 typedef void    (*kxdreproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
 239                 const void *obj);
 240 typedef int     (*kxdrdproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
 241                 void *obj);
 242
 243 extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf,
 244                             __be32 *p, struct rpc_rqst *rqst);
 245 extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes);
 246 extern void xdr_commit_encode(struct xdr_stream *xdr);
 247 extern void xdr_truncate_encode(struct xdr_stream *xdr, size_t len);
 248 extern int xdr_restrict_buflen(struct xdr_stream *xdr, int newbuflen);
 249 extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages,
 250                 unsigned int base, unsigned int len);
 251 extern unsigned int xdr_stream_pos(const struct xdr_stream *xdr);
 252 extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf,
 253                             __be32 *p, struct rpc_rqst *rqst);
 254 extern void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf,
 255                 struct page **pages, unsigned int len);
 256 extern void xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen);
 257 extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes);
 258 extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len);
 259 extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);
 260 extern int xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);
 261
 262 /**
 263  * xdr_stream_remaining - Return the number of bytes remaining in the stream
 264  * @xdr: pointer to struct xdr_stream
 265  *
 266  * Return value:
 267  *   Number of bytes remaining in @xdr before xdr->end
 268  */
 269 static inline size_t
 270 xdr_stream_remaining(const struct xdr_stream *xdr)
 271 {
 272         return xdr->nwords << 2;
 273 }
 274
 275 ssize_t xdr_stream_decode_opaque(struct xdr_stream *xdr, void *ptr,
 276                 size_t size);
 277 ssize_t xdr_stream_decode_opaque_dup(struct xdr_stream *xdr, void **ptr,
 278                 size_t maxlen, gfp_t gfp_flags);
 279 ssize_t xdr_stream_decode_string(struct xdr_stream *xdr, char *str,
 280                 size_t size);
 281 ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str,
 282                 size_t maxlen, gfp_t gfp_flags);
 283 /**
 284  * xdr_align_size - Calculate padded size of an object
 285  * @n: Size of an object being XDR encoded (in bytes)
 286  *
 287  * Return value:
 288  *   Size (in bytes) of the object including xdr padding
 289  */
 290 static inline size_t
 291 xdr_align_size(size_t n)
 292 {
 293         const size_t mask = sizeof(__u32) - 1;
 294
 295         return (n + mask) & ~mask;
 296 }
 297
 298 /**
 299  * xdr_stream_encode_u32 - Encode a 32-bit integer
 300  * @xdr: pointer to xdr_stream
 301  * @n: integer to encode
 302  *
 303  * Return values:
 304  *   On success, returns length in bytes of XDR buffer consumed
 305  *   %-EMSGSIZE on XDR buffer overflow
 306  */
 307 static inline ssize_t
 308 xdr_stream_encode_u32(struct xdr_stream *xdr, __u32 n)
 309 {
 310         const size_t len = sizeof(n);
 311         __be32 *p = xdr_reserve_space(xdr, len);
 312
 313         if (unlikely(!p))
 314                 return -EMSGSIZE;
 315         *p = cpu_to_be32(n);
 316         return len;
 317 }
 318
 319 /**
 320  * xdr_stream_encode_u64 - Encode a 64-bit integer
 321  * @xdr: pointer to xdr_stream
 322  * @n: 64-bit integer to encode
 323  *
 324  * Return values:
 325  *   On success, returns length in bytes of XDR buffer consumed
 326  *   %-EMSGSIZE on XDR buffer overflow
 327  */
 328 static inline ssize_t
 329 xdr_stream_encode_u64(struct xdr_stream *xdr, __u64 n)
 330 {
 331         const size_t len = sizeof(n);
 332         __be32 *p = xdr_reserve_space(xdr, len);
 333
 334         if (unlikely(!p))
 335                 return -EMSGSIZE;
 336         xdr_encode_hyper(p, n);
 337         return len;
 338 }
 339
 340 /**
 341  * xdr_stream_encode_opaque_inline - Encode opaque xdr data
 342  * @xdr: pointer to xdr_stream
 343  * @ptr: pointer to void pointer
 344  * @len: size of object
 345  *
 346  * Return values:
 347  *   On success, returns length in bytes of XDR buffer consumed
 348  *   %-EMSGSIZE on XDR buffer overflow
 349  */
 350 static inline ssize_t
 351 xdr_stream_encode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t len)
 352 {
 353         size_t count = sizeof(__u32) + xdr_align_size(len);
 354         __be32 *p = xdr_reserve_space(xdr, count);
 355
 356         if (unlikely(!p)) {
 357                 *ptr = NULL;
 358                 return -EMSGSIZE;
 359         }
 360         xdr_encode_opaque(p, NULL, len);
 361         *ptr = ++p;
 362         return count;
 363 }
 364
 365 /**
 366  * xdr_stream_encode_opaque_fixed - Encode fixed length opaque xdr data
 367  * @xdr: pointer to xdr_stream
 368  * @ptr: pointer to opaque data object
 369  * @len: size of object pointed to by @ptr
 370  *
 371  * Return values:
 372  *   On success, returns length in bytes of XDR buffer consumed
 373  *   %-EMSGSIZE on XDR buffer overflow
 374  */
 375 static inline ssize_t
 376 xdr_stream_encode_opaque_fixed(struct xdr_stream *xdr, const void *ptr, size_t len)
 377 {
 378         __be32 *p = xdr_reserve_space(xdr, len);
 379
 380         if (unlikely(!p))
 381                 return -EMSGSIZE;
 382         xdr_encode_opaque_fixed(p, ptr, len);
 383         return xdr_align_size(len);
 384 }
 385
 386 /**
 387  * xdr_stream_encode_opaque - Encode variable length opaque xdr data
 388  * @xdr: pointer to xdr_stream
 389  * @ptr: pointer to opaque data object
 390  * @len: size of object pointed to by @ptr
 391  *
 392  * Return values:
 393  *   On success, returns length in bytes of XDR buffer consumed
 394  *   %-EMSGSIZE on XDR buffer overflow
 395  */
 396 static inline ssize_t
 397 xdr_stream_encode_opaque(struct xdr_stream *xdr, const void *ptr, size_t len)
 398 {
 399         size_t count = sizeof(__u32) + xdr_align_size(len);
 400         __be32 *p = xdr_reserve_space(xdr, count);
 401
 402         if (unlikely(!p))
 403                 return -EMSGSIZE;
 404         xdr_encode_opaque(p, ptr, len);
 405         return count;
 406 }
 407
 408 /**
 409  * xdr_stream_encode_uint32_array - Encode variable length array of integers
 410  * @xdr: pointer to xdr_stream
 411  * @array: array of integers
 412  * @array_size: number of elements in @array
 413  *
 414  * Return values:
 415  *   On success, returns length in bytes of XDR buffer consumed
 416  *   %-EMSGSIZE on XDR buffer overflow
 417  */
 418 static inline ssize_t
 419 xdr_stream_encode_uint32_array(struct xdr_stream *xdr,
 420                 const __u32 *array, size_t array_size)
 421 {
 422         ssize_t ret = (array_size+1) * sizeof(__u32);
 423         __be32 *p = xdr_reserve_space(xdr, ret);
 424
 425         if (unlikely(!p))
 426                 return -EMSGSIZE;
 427         *p++ = cpu_to_be32(array_size);
 428         for (; array_size > 0; p++, array++, array_size--)
 429                 *p = cpu_to_be32p(array);
 430         return ret;
 431 }
 432
 433 /**
 434  * xdr_stream_decode_u32 - Decode a 32-bit integer
 435  * @xdr: pointer to xdr_stream
 436  * @ptr: location to store integer
 437  *
 438  * Return values:
 439  *   %0 on success
 440  *   %-EBADMSG on XDR buffer overflow
 441  */
 442 static inline ssize_t
 443 xdr_stream_decode_u32(struct xdr_stream *xdr, __u32 *ptr)
 444 {
 445         const size_t count = sizeof(*ptr);
 446         __be32 *p = xdr_inline_decode(xdr, count);
 447
 448         if (unlikely(!p))
 449                 return -EBADMSG;
 450         *ptr = be32_to_cpup(p);
 451         return 0;
 452 }
 453
 454 /**
 455  * xdr_stream_decode_opaque_fixed - Decode fixed length opaque xdr data
 456  * @xdr: pointer to xdr_stream
 457  * @ptr: location to store data
 458  * @len: size of buffer pointed to by @ptr
 459  *
 460  * Return values:
 461  *   On success, returns size of object stored in @ptr
 462  *   %-EBADMSG on XDR buffer overflow
 463  */
 464 static inline ssize_t
 465 xdr_stream_decode_opaque_fixed(struct xdr_stream *xdr, void *ptr, size_t len)
 466 {
 467         __be32 *p = xdr_inline_decode(xdr, len);
 468
 469         if (unlikely(!p))
 470                 return -EBADMSG;
 471         xdr_decode_opaque_fixed(p, ptr, len);
 472         return len;
 473 }
 474
 475 /**
 476  * xdr_stream_decode_opaque_inline - Decode variable length opaque xdr data
 477  * @xdr: pointer to xdr_stream
 478  * @ptr: location to store pointer to opaque data
 479  * @maxlen: maximum acceptable object size
 480  *
 481  * Note: the pointer stored in @ptr cannot be assumed valid after the XDR
 482  * buffer has been destroyed, or even after calling xdr_inline_decode()
 483  * on @xdr. It is therefore expected that the object it points to should
 484  * be processed immediately.
 485  *
 486  * Return values:
 487  *   On success, returns size of object stored in *@ptr
 488  *   %-EBADMSG on XDR buffer overflow
 489  *   %-EMSGSIZE if the size of the object would exceed @maxlen
 490  */
 491 static inline ssize_t
 492 xdr_stream_decode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t maxlen)
 493 {
 494         __be32 *p;
 495         __u32 len;
 496
 497         *ptr = NULL;
 498         if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
 499                 return -EBADMSG;
 500         if (len != 0) {
 501                 p = xdr_inline_decode(xdr, len);
 502                 if (unlikely(!p))
 503                         return -EBADMSG;
 504                 if (unlikely(len > maxlen))
 505                         return -EMSGSIZE;
 506                 *ptr = p;
 507         }
 508         return len;
 509 }
 510
 511 /**
 512  * xdr_stream_decode_uint32_array - Decode variable length array of integers
 513  * @xdr: pointer to xdr_stream
 514  * @array: location to store the integer array or NULL
 515  * @array_size: number of elements to store
 516  *
 517  * Return values:
 518  *   On success, returns number of elements stored in @array
 519  *   %-EBADMSG on XDR buffer overflow
 520  *   %-EMSGSIZE if the size of the array exceeds @array_size
 521  */
 522 static inline ssize_t
 523 xdr_stream_decode_uint32_array(struct xdr_stream *xdr,
 524                 __u32 *array, size_t array_size)
 525 {
 526         __be32 *p;
 527         __u32 len;
 528         ssize_t retval;
 529
 530         if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
 531                 return -EBADMSG;
 532         p = xdr_inline_decode(xdr, len * sizeof(*p));
 533         if (unlikely(!p))
 534                 return -EBADMSG;
 535         if (array == NULL)
 536                 return len;
 537         if (len <= array_size) {
 538                 if (len < array_size)
 539                         memset(array+len, 0, (array_size-len)*sizeof(*array));
 540                 array_size = len;
 541                 retval = len;
 542         } else
 543                 retval = -EMSGSIZE;
 544         for (; array_size > 0; p++, array++, array_size--)
 545                 *array = be32_to_cpup(p);
 546         return retval;
 547 }
 548 #endif /* __KERNEL__ */
 549
 550 #endif /* _SUNRPC_XDR_H_ */