1 /* SPDX-License-Identifier: GPL-2.0 */
3 * XDR standard data types and function declarations
5 * Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>
8 * RFC 4506 "XDR: External Data Representation Standard", May 2006
11 #ifndef _SUNRPC_XDR_H_
12 #define _SUNRPC_XDR_H_
14 #include <linux/uio.h>
15 #include <asm/byteorder.h>
16 #include <asm/unaligned.h>
17 #include <linux/scatterlist.h>
23 * Size of an XDR encoding unit in bytes, i.e. 32 bits,
24 * as defined in Section 3 of RFC 4506. All encoded
25 * XDR data items are aligned on a boundary of 32 bits.
27 #define XDR_UNIT sizeof(__be32)
32 #define XDR_QUADLEN(l) (((l) + 3) >> 2)
35 * Generic opaque `network object.'
37 #define XDR_MAX_NETOBJ 1024
44 * Basic structure for transmission/reception of a client XDR message.
45 * Features a header (for a linear buffer containing RPC headers
46 * and the data payload for short messages), and then an array of
48 * The tail iovec allows you to append data after the page array. Its
49 * main interest is for appending padding to the pages in order to
50 * satisfy the int_32-alignment requirements in RFC1832.
52 * For the future, we might want to string several of these together
53 * in a list if anybody wants to make use of NFSv4 COMPOUND
54 * operations and/or has a need for scatter/gather involving pages.
57 struct kvec head[1], /* RPC header + non-page data */
58 tail[1]; /* Appended after page data */
61 struct page ** pages; /* Array of pages */
62 unsigned int page_base, /* Start of page data */
63 page_len, /* Length of page data */
64 flags; /* Flags for data disposition */
65 #define XDRBUF_READ 0x01 /* target of file read */
66 #define XDRBUF_WRITE 0x02 /* source of file write */
67 #define XDRBUF_SPARSE_PAGES 0x04 /* Page array is sparse */
69 unsigned int buflen, /* Total length of storage buffer */
70 len; /* Length of XDR encoded message */
74 xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
76 buf->head[0].iov_base = start;
77 buf->head[0].iov_len = len;
78 buf->tail[0].iov_len = 0;
90 #define xdr_zero cpu_to_be32(0)
91 #define xdr_one cpu_to_be32(1)
92 #define xdr_two cpu_to_be32(2)
94 #define rpc_auth_null cpu_to_be32(RPC_AUTH_NULL)
95 #define rpc_auth_unix cpu_to_be32(RPC_AUTH_UNIX)
96 #define rpc_auth_short cpu_to_be32(RPC_AUTH_SHORT)
97 #define rpc_auth_gss cpu_to_be32(RPC_AUTH_GSS)
98 #define rpc_auth_tls cpu_to_be32(RPC_AUTH_TLS)
100 #define rpc_call cpu_to_be32(RPC_CALL)
101 #define rpc_reply cpu_to_be32(RPC_REPLY)
103 #define rpc_msg_accepted cpu_to_be32(RPC_MSG_ACCEPTED)
105 #define rpc_success cpu_to_be32(RPC_SUCCESS)
106 #define rpc_prog_unavail cpu_to_be32(RPC_PROG_UNAVAIL)
107 #define rpc_prog_mismatch cpu_to_be32(RPC_PROG_MISMATCH)
108 #define rpc_proc_unavail cpu_to_be32(RPC_PROC_UNAVAIL)
109 #define rpc_garbage_args cpu_to_be32(RPC_GARBAGE_ARGS)
110 #define rpc_system_err cpu_to_be32(RPC_SYSTEM_ERR)
111 #define rpc_drop_reply cpu_to_be32(RPC_DROP_REPLY)
113 #define rpc_mismatch cpu_to_be32(RPC_MISMATCH)
114 #define rpc_auth_error cpu_to_be32(RPC_AUTH_ERROR)
116 #define rpc_auth_ok cpu_to_be32(RPC_AUTH_OK)
117 #define rpc_autherr_badcred cpu_to_be32(RPC_AUTH_BADCRED)
118 #define rpc_autherr_rejectedcred cpu_to_be32(RPC_AUTH_REJECTEDCRED)
119 #define rpc_autherr_badverf cpu_to_be32(RPC_AUTH_BADVERF)
120 #define rpc_autherr_rejectedverf cpu_to_be32(RPC_AUTH_REJECTEDVERF)
121 #define rpc_autherr_tooweak cpu_to_be32(RPC_AUTH_TOOWEAK)
122 #define rpcsec_gsserr_credproblem cpu_to_be32(RPCSEC_GSS_CREDPROBLEM)
123 #define rpcsec_gsserr_ctxproblem cpu_to_be32(RPCSEC_GSS_CTXPROBLEM)
126 * Miscellaneous XDR helper functions
128 __be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int len);
129 __be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int len);
130 __be32 *xdr_encode_string(__be32 *p, const char *s);
131 __be32 *xdr_decode_string_inplace(__be32 *p, char **sp, unsigned int *lenp,
132 unsigned int maxlen);
133 __be32 *xdr_encode_netobj(__be32 *p, const struct xdr_netobj *);
134 __be32 *xdr_decode_netobj(__be32 *p, struct xdr_netobj *);
136 void xdr_inline_pages(struct xdr_buf *, unsigned int,
137 struct page **, unsigned int, unsigned int);
138 void xdr_terminate_string(const struct xdr_buf *, const u32);
139 size_t xdr_buf_pagecount(const struct xdr_buf *buf);
140 int xdr_alloc_bvec(struct xdr_buf *buf, gfp_t gfp);
141 void xdr_free_bvec(struct xdr_buf *buf);
143 static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len)
145 return xdr_encode_opaque(p, s, len);
149 * Decode 64bit quantities (NFSv3 support)
151 static inline __be32 *
152 xdr_encode_hyper(__be32 *p, __u64 val)
154 put_unaligned_be64(val, p);
158 static inline __be32 *
159 xdr_decode_hyper(__be32 *p, __u64 *valp)
161 *valp = get_unaligned_be64(p);
165 static inline __be32 *
166 xdr_decode_opaque_fixed(__be32 *p, void *ptr, unsigned int len)
169 return p + XDR_QUADLEN(len);
172 static inline void xdr_netobj_dup(struct xdr_netobj *dst,
173 struct xdr_netobj *src, gfp_t gfp_mask)
175 dst->data = kmemdup(src->data, src->len, gfp_mask);
180 * Adjust kvec to reflect end of xdr'ed data (RPC client XDR)
183 xdr_adjust_iovec(struct kvec *iov, __be32 *p)
185 return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base);
189 * XDR buffer helper functions
191 extern void xdr_shift_buf(struct xdr_buf *, size_t);
192 extern void xdr_buf_from_iov(const struct kvec *, struct xdr_buf *);
193 extern int xdr_buf_subsegment(const struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int);
194 extern void xdr_buf_trim(struct xdr_buf *, unsigned int);
195 extern int read_bytes_from_xdr_buf(const struct xdr_buf *, unsigned int, void *, unsigned int);
196 extern int write_bytes_to_xdr_buf(const struct xdr_buf *, unsigned int, void *, unsigned int);
198 extern int xdr_encode_word(const struct xdr_buf *, unsigned int, u32);
199 extern int xdr_decode_word(const struct xdr_buf *, unsigned int, u32 *);
201 struct xdr_array2_desc;
202 typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem);
203 struct xdr_array2_desc {
204 unsigned int elem_size;
205 unsigned int array_len;
206 unsigned int array_maxlen;
207 xdr_xcode_elem_t xcode;
210 extern int xdr_decode_array2(const struct xdr_buf *buf, unsigned int base,
211 struct xdr_array2_desc *desc);
212 extern int xdr_encode_array2(const struct xdr_buf *buf, unsigned int base,
213 struct xdr_array2_desc *desc);
214 extern void _copy_from_pages(char *p, struct page **pages, size_t pgbase,
218 * Provide some simple tools for XDR buffer overflow-checking etc.
221 __be32 *p; /* start of available buffer */
222 struct xdr_buf *buf; /* XDR buffer to read/write */
224 __be32 *end; /* end of available buffer space */
225 struct kvec *iov; /* pointer to the current kvec */
226 struct kvec scratch; /* Scratch buffer */
227 struct page **page_ptr; /* pointer to the current page */
228 unsigned int nwords; /* Remaining decode buffer length */
230 struct rpc_rqst *rqst; /* For debugging */
234 * These are the xdr_stream style generic XDR encode and decode functions.
236 typedef void (*kxdreproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
238 typedef int (*kxdrdproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
241 extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf,
242 __be32 *p, struct rpc_rqst *rqst);
243 extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes);
244 extern int xdr_reserve_space_vec(struct xdr_stream *xdr, struct kvec *vec,
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 unsigned int xdr_page_pos(const struct xdr_stream *xdr);
253 extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf,
254 __be32 *p, struct rpc_rqst *rqst);
255 extern void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf,
256 struct page **pages, unsigned int len);
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(const struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);
261 extern void xdr_set_pagelen(struct xdr_stream *, unsigned int len);
262 extern bool xdr_stream_subsegment(struct xdr_stream *xdr, struct xdr_buf *subbuf,
264 extern unsigned int xdr_stream_move_subsegment(struct xdr_stream *xdr, unsigned int offset,
265 unsigned int target, unsigned int length);
266 extern unsigned int xdr_stream_zero(struct xdr_stream *xdr, unsigned int offset,
267 unsigned int length);
270 * xdr_set_scratch_buffer - Attach a scratch buffer for decoding data.
271 * @xdr: pointer to xdr_stream struct
272 * @buf: pointer to an empty buffer
273 * @buflen: size of 'buf'
275 * The scratch buffer is used when decoding from an array of pages.
276 * If an xdr_inline_decode() call spans across page boundaries, then
277 * we copy the data into the scratch buffer in order to allow linear
281 xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen)
283 xdr->scratch.iov_base = buf;
284 xdr->scratch.iov_len = buflen;
288 * xdr_set_scratch_page - Attach a scratch buffer for decoding data
289 * @xdr: pointer to xdr_stream struct
290 * @page: an anonymous page
292 * See xdr_set_scratch_buffer().
295 xdr_set_scratch_page(struct xdr_stream *xdr, struct page *page)
297 xdr_set_scratch_buffer(xdr, page_address(page), PAGE_SIZE);
301 * xdr_reset_scratch_buffer - Clear scratch buffer information
302 * @xdr: pointer to xdr_stream struct
304 * See xdr_set_scratch_buffer().
307 xdr_reset_scratch_buffer(struct xdr_stream *xdr)
309 xdr_set_scratch_buffer(xdr, NULL, 0);
313 * xdr_commit_encode - Ensure all data is written to xdr->buf
314 * @xdr: pointer to xdr_stream
316 * Handle encoding across page boundaries by giving the caller a
317 * temporary location to write to, then later copying the data into
318 * place. __xdr_commit_encode() does that copying.
320 static inline void xdr_commit_encode(struct xdr_stream *xdr)
322 if (unlikely(xdr->scratch.iov_len))
323 __xdr_commit_encode(xdr);
327 * xdr_stream_remaining - Return the number of bytes remaining in the stream
328 * @xdr: pointer to struct xdr_stream
331 * Number of bytes remaining in @xdr before xdr->end
334 xdr_stream_remaining(const struct xdr_stream *xdr)
336 return xdr->nwords << 2;
339 ssize_t xdr_stream_decode_opaque(struct xdr_stream *xdr, void *ptr,
341 ssize_t xdr_stream_decode_opaque_dup(struct xdr_stream *xdr, void **ptr,
342 size_t maxlen, gfp_t gfp_flags);
343 ssize_t xdr_stream_decode_string(struct xdr_stream *xdr, char *str,
345 ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str,
346 size_t maxlen, gfp_t gfp_flags);
348 * xdr_align_size - Calculate padded size of an object
349 * @n: Size of an object being XDR encoded (in bytes)
352 * Size (in bytes) of the object including xdr padding
355 xdr_align_size(size_t n)
357 const size_t mask = XDR_UNIT - 1;
359 return (n + mask) & ~mask;
363 * xdr_pad_size - Calculate size of an object's pad
364 * @n: Size of an object being XDR encoded (in bytes)
366 * This implementation avoids the need for conditional
367 * branches or modulo division.
370 * Size (in bytes) of the needed XDR pad
372 static inline size_t xdr_pad_size(size_t n)
374 return xdr_align_size(n) - n;
378 * xdr_stream_encode_item_present - Encode a "present" list item
379 * @xdr: pointer to xdr_stream
382 * On success, returns length in bytes of XDR buffer consumed
383 * %-EMSGSIZE on XDR buffer overflow
385 static inline ssize_t xdr_stream_encode_item_present(struct xdr_stream *xdr)
387 const size_t len = XDR_UNIT;
388 __be32 *p = xdr_reserve_space(xdr, len);
397 * xdr_stream_encode_item_absent - Encode a "not present" list item
398 * @xdr: pointer to xdr_stream
401 * On success, returns length in bytes of XDR buffer consumed
402 * %-EMSGSIZE on XDR buffer overflow
404 static inline int xdr_stream_encode_item_absent(struct xdr_stream *xdr)
406 const size_t len = XDR_UNIT;
407 __be32 *p = xdr_reserve_space(xdr, len);
416 * xdr_encode_bool - Encode a boolean item
417 * @p: address in a buffer into which to encode
418 * @n: boolean value to encode
421 * Address of item following the encoded boolean
423 static inline __be32 *xdr_encode_bool(__be32 *p, u32 n)
425 *p++ = n ? xdr_one : xdr_zero;
430 * xdr_stream_encode_bool - Encode a boolean item
431 * @xdr: pointer to xdr_stream
432 * @n: boolean value to encode
435 * On success, returns length in bytes of XDR buffer consumed
436 * %-EMSGSIZE on XDR buffer overflow
438 static inline int xdr_stream_encode_bool(struct xdr_stream *xdr, __u32 n)
440 const size_t len = XDR_UNIT;
441 __be32 *p = xdr_reserve_space(xdr, len);
445 xdr_encode_bool(p, n);
450 * xdr_stream_encode_u32 - Encode a 32-bit integer
451 * @xdr: pointer to xdr_stream
452 * @n: integer to encode
455 * On success, returns length in bytes of XDR buffer consumed
456 * %-EMSGSIZE on XDR buffer overflow
458 static inline ssize_t
459 xdr_stream_encode_u32(struct xdr_stream *xdr, __u32 n)
461 const size_t len = sizeof(n);
462 __be32 *p = xdr_reserve_space(xdr, len);
471 * xdr_stream_encode_u64 - Encode a 64-bit integer
472 * @xdr: pointer to xdr_stream
473 * @n: 64-bit integer to encode
476 * On success, returns length in bytes of XDR buffer consumed
477 * %-EMSGSIZE on XDR buffer overflow
479 static inline ssize_t
480 xdr_stream_encode_u64(struct xdr_stream *xdr, __u64 n)
482 const size_t len = sizeof(n);
483 __be32 *p = xdr_reserve_space(xdr, len);
487 xdr_encode_hyper(p, n);
492 * xdr_stream_encode_opaque_inline - Encode opaque xdr data
493 * @xdr: pointer to xdr_stream
494 * @ptr: pointer to void pointer
495 * @len: size of object
498 * On success, returns length in bytes of XDR buffer consumed
499 * %-EMSGSIZE on XDR buffer overflow
501 static inline ssize_t
502 xdr_stream_encode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t len)
504 size_t count = sizeof(__u32) + xdr_align_size(len);
505 __be32 *p = xdr_reserve_space(xdr, count);
511 xdr_encode_opaque(p, NULL, len);
517 * xdr_stream_encode_opaque_fixed - Encode fixed length opaque xdr data
518 * @xdr: pointer to xdr_stream
519 * @ptr: pointer to opaque data object
520 * @len: size of object pointed to by @ptr
523 * On success, returns length in bytes of XDR buffer consumed
524 * %-EMSGSIZE on XDR buffer overflow
526 static inline ssize_t
527 xdr_stream_encode_opaque_fixed(struct xdr_stream *xdr, const void *ptr, size_t len)
529 __be32 *p = xdr_reserve_space(xdr, len);
533 xdr_encode_opaque_fixed(p, ptr, len);
534 return xdr_align_size(len);
538 * xdr_stream_encode_opaque - Encode variable length opaque xdr data
539 * @xdr: pointer to xdr_stream
540 * @ptr: pointer to opaque data object
541 * @len: size of object pointed to by @ptr
544 * On success, returns length in bytes of XDR buffer consumed
545 * %-EMSGSIZE on XDR buffer overflow
547 static inline ssize_t
548 xdr_stream_encode_opaque(struct xdr_stream *xdr, const void *ptr, size_t len)
550 size_t count = sizeof(__u32) + xdr_align_size(len);
551 __be32 *p = xdr_reserve_space(xdr, count);
555 xdr_encode_opaque(p, ptr, len);
560 * xdr_stream_encode_uint32_array - Encode variable length array of integers
561 * @xdr: pointer to xdr_stream
562 * @array: array of integers
563 * @array_size: number of elements in @array
566 * On success, returns length in bytes of XDR buffer consumed
567 * %-EMSGSIZE on XDR buffer overflow
569 static inline ssize_t
570 xdr_stream_encode_uint32_array(struct xdr_stream *xdr,
571 const __u32 *array, size_t array_size)
573 ssize_t ret = (array_size+1) * sizeof(__u32);
574 __be32 *p = xdr_reserve_space(xdr, ret);
578 *p++ = cpu_to_be32(array_size);
579 for (; array_size > 0; p++, array++, array_size--)
580 *p = cpu_to_be32p(array);
585 * xdr_item_is_absent - symbolically handle XDR discriminators
586 * @p: pointer to undecoded discriminator
589 * %true if the following XDR item is absent
590 * %false if the following XDR item is present
592 static inline bool xdr_item_is_absent(const __be32 *p)
594 return *p == xdr_zero;
598 * xdr_item_is_present - symbolically handle XDR discriminators
599 * @p: pointer to undecoded discriminator
602 * %true if the following XDR item is present
603 * %false if the following XDR item is absent
605 static inline bool xdr_item_is_present(const __be32 *p)
607 return *p != xdr_zero;
611 * xdr_stream_decode_bool - Decode a boolean
612 * @xdr: pointer to xdr_stream
613 * @ptr: pointer to a u32 in which to store the result
617 * %-EBADMSG on XDR buffer overflow
619 static inline ssize_t
620 xdr_stream_decode_bool(struct xdr_stream *xdr, __u32 *ptr)
622 const size_t count = sizeof(*ptr);
623 __be32 *p = xdr_inline_decode(xdr, count);
627 *ptr = (*p != xdr_zero);
632 * xdr_stream_decode_u32 - Decode a 32-bit integer
633 * @xdr: pointer to xdr_stream
634 * @ptr: location to store integer
638 * %-EBADMSG on XDR buffer overflow
640 static inline ssize_t
641 xdr_stream_decode_u32(struct xdr_stream *xdr, __u32 *ptr)
643 const size_t count = sizeof(*ptr);
644 __be32 *p = xdr_inline_decode(xdr, count);
648 *ptr = be32_to_cpup(p);
653 * xdr_stream_decode_u64 - Decode a 64-bit integer
654 * @xdr: pointer to xdr_stream
655 * @ptr: location to store 64-bit integer
659 * %-EBADMSG on XDR buffer overflow
661 static inline ssize_t
662 xdr_stream_decode_u64(struct xdr_stream *xdr, __u64 *ptr)
664 const size_t count = sizeof(*ptr);
665 __be32 *p = xdr_inline_decode(xdr, count);
669 xdr_decode_hyper(p, ptr);
674 * xdr_stream_decode_opaque_fixed - Decode fixed length opaque xdr data
675 * @xdr: pointer to xdr_stream
676 * @ptr: location to store data
677 * @len: size of buffer pointed to by @ptr
680 * On success, returns size of object stored in @ptr
681 * %-EBADMSG on XDR buffer overflow
683 static inline ssize_t
684 xdr_stream_decode_opaque_fixed(struct xdr_stream *xdr, void *ptr, size_t len)
686 __be32 *p = xdr_inline_decode(xdr, len);
690 xdr_decode_opaque_fixed(p, ptr, len);
695 * xdr_stream_decode_opaque_inline - Decode variable length opaque xdr data
696 * @xdr: pointer to xdr_stream
697 * @ptr: location to store pointer to opaque data
698 * @maxlen: maximum acceptable object size
700 * Note: the pointer stored in @ptr cannot be assumed valid after the XDR
701 * buffer has been destroyed, or even after calling xdr_inline_decode()
702 * on @xdr. It is therefore expected that the object it points to should
703 * be processed immediately.
706 * On success, returns size of object stored in *@ptr
707 * %-EBADMSG on XDR buffer overflow
708 * %-EMSGSIZE if the size of the object would exceed @maxlen
710 static inline ssize_t
711 xdr_stream_decode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t maxlen)
717 if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
720 p = xdr_inline_decode(xdr, len);
723 if (unlikely(len > maxlen))
731 * xdr_stream_decode_uint32_array - Decode variable length array of integers
732 * @xdr: pointer to xdr_stream
733 * @array: location to store the integer array or NULL
734 * @array_size: number of elements to store
737 * On success, returns number of elements stored in @array
738 * %-EBADMSG on XDR buffer overflow
739 * %-EMSGSIZE if the size of the array exceeds @array_size
741 static inline ssize_t
742 xdr_stream_decode_uint32_array(struct xdr_stream *xdr,
743 __u32 *array, size_t array_size)
749 if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
751 if (len > SIZE_MAX / sizeof(*p))
753 p = xdr_inline_decode(xdr, len * sizeof(*p));
758 if (len <= array_size) {
759 if (len < array_size)
760 memset(array+len, 0, (array_size-len)*sizeof(*array));
765 for (; array_size > 0; p++, array++, array_size--)
766 *array = be32_to_cpup(p);
770 #endif /* _SUNRPC_XDR_H_ */