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Linux kernel mirror (for testing)
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linux
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
20struct rpc_rqst;
21
22/*
23 * Buffer adjustment
24 */
25#define XDR_QUADLEN(l) (((l) + 3) >> 2)
26
27/*
28 * Generic opaque `network object.' At the kernel level, this type
29 * is used only by lockd.
30 */
31#define XDR_MAX_NETOBJ 1024
32struct xdr_netobj {
33 unsigned int len;
34 u8 * data;
35};
36
37/*
38 * Basic structure for transmission/reception of a client XDR message.
39 * Features a header (for a linear buffer containing RPC headers
40 * and the data payload for short messages), and then an array of
41 * pages.
42 * The tail iovec allows you to append data after the page array. Its
43 * main interest is for appending padding to the pages in order to
44 * satisfy the int_32-alignment requirements in RFC1832.
45 *
46 * For the future, we might want to string several of these together
47 * in a list if anybody wants to make use of NFSv4 COMPOUND
48 * operations and/or has a need for scatter/gather involving pages.
49 */
50struct xdr_buf {
51 struct kvec head[1], /* RPC header + non-page data */
52 tail[1]; /* Appended after page data */
53
54 struct page ** pages; /* Array of pages */
55 unsigned int page_base, /* Start of page data */
56 page_len, /* Length of page data */
57 flags; /* Flags for data disposition */
58#define XDRBUF_READ 0x01 /* target of file read */
59#define XDRBUF_WRITE 0x02 /* source of file write */
60
61 unsigned int buflen, /* Total length of storage buffer */
62 len; /* Length of XDR encoded message */
63};
64
65static inline void
66xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
67{
68 buf->head[0].iov_base = start;
69 buf->head[0].iov_len = len;
70 buf->tail[0].iov_len = 0;
71 buf->page_len = 0;
72 buf->flags = 0;
73 buf->len = 0;
74 buf->buflen = len;
75}
76
77/*
78 * pre-xdr'ed macros.
79 */
80
81#define xdr_zero cpu_to_be32(0)
82#define xdr_one cpu_to_be32(1)
83#define xdr_two cpu_to_be32(2)
84
85#define rpc_success cpu_to_be32(RPC_SUCCESS)
86#define rpc_prog_unavail cpu_to_be32(RPC_PROG_UNAVAIL)
87#define rpc_prog_mismatch cpu_to_be32(RPC_PROG_MISMATCH)
88#define rpc_proc_unavail cpu_to_be32(RPC_PROC_UNAVAIL)
89#define rpc_garbage_args cpu_to_be32(RPC_GARBAGE_ARGS)
90#define rpc_system_err cpu_to_be32(RPC_SYSTEM_ERR)
91#define rpc_drop_reply cpu_to_be32(RPC_DROP_REPLY)
92
93#define rpc_auth_ok cpu_to_be32(RPC_AUTH_OK)
94#define rpc_autherr_badcred cpu_to_be32(RPC_AUTH_BADCRED)
95#define rpc_autherr_rejectedcred cpu_to_be32(RPC_AUTH_REJECTEDCRED)
96#define rpc_autherr_badverf cpu_to_be32(RPC_AUTH_BADVERF)
97#define rpc_autherr_rejectedverf cpu_to_be32(RPC_AUTH_REJECTEDVERF)
98#define rpc_autherr_tooweak cpu_to_be32(RPC_AUTH_TOOWEAK)
99#define rpcsec_gsserr_credproblem cpu_to_be32(RPCSEC_GSS_CREDPROBLEM)
100#define rpcsec_gsserr_ctxproblem cpu_to_be32(RPCSEC_GSS_CTXPROBLEM)
101#define rpc_autherr_oldseqnum cpu_to_be32(101)
102
103/*
104 * Miscellaneous XDR helper functions
105 */
106__be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int len);
107__be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int len);
108__be32 *xdr_encode_string(__be32 *p, const char *s);
109__be32 *xdr_decode_string_inplace(__be32 *p, char **sp, unsigned int *lenp,
110 unsigned int maxlen);
111__be32 *xdr_encode_netobj(__be32 *p, const struct xdr_netobj *);
112__be32 *xdr_decode_netobj(__be32 *p, struct xdr_netobj *);
113
114void xdr_inline_pages(struct xdr_buf *, unsigned int,
115 struct page **, unsigned int, unsigned int);
116void xdr_terminate_string(struct xdr_buf *, const u32);
117
118static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len)
119{
120 return xdr_encode_opaque(p, s, len);
121}
122
123/*
124 * Decode 64bit quantities (NFSv3 support)
125 */
126static inline __be32 *
127xdr_encode_hyper(__be32 *p, __u64 val)
128{
129 put_unaligned_be64(val, p);
130 return p + 2;
131}
132
133static inline __be32 *
134xdr_decode_hyper(__be32 *p, __u64 *valp)
135{
136 *valp = get_unaligned_be64(p);
137 return p + 2;
138}
139
140static inline __be32 *
141xdr_decode_opaque_fixed(__be32 *p, void *ptr, unsigned int len)
142{
143 memcpy(ptr, p, len);
144 return p + XDR_QUADLEN(len);
145}
146
147/*
148 * Adjust kvec to reflect end of xdr'ed data (RPC client XDR)
149 */
150static inline int
151xdr_adjust_iovec(struct kvec *iov, __be32 *p)
152{
153 return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base);
154}
155
156/*
157 * XDR buffer helper functions
158 */
159extern void xdr_shift_buf(struct xdr_buf *, size_t);
160extern void xdr_buf_from_iov(struct kvec *, struct xdr_buf *);
161extern int xdr_buf_subsegment(struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int);
162extern void xdr_buf_trim(struct xdr_buf *, unsigned int);
163extern int xdr_buf_read_netobj(struct xdr_buf *, struct xdr_netobj *, unsigned int);
164extern int read_bytes_from_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
165extern int write_bytes_to_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
166
167/*
168 * Helper structure for copying from an sk_buff.
169 */
170struct xdr_skb_reader {
171 struct sk_buff *skb;
172 unsigned int offset;
173 size_t count;
174 __wsum csum;
175};
176
177typedef size_t (*xdr_skb_read_actor)(struct xdr_skb_reader *desc, void *to, size_t len);
178
179size_t xdr_skb_read_bits(struct xdr_skb_reader *desc, void *to, size_t len);
180extern int csum_partial_copy_to_xdr(struct xdr_buf *, struct sk_buff *);
181extern ssize_t xdr_partial_copy_from_skb(struct xdr_buf *, unsigned int,
182 struct xdr_skb_reader *, xdr_skb_read_actor);
183
184extern int xdr_encode_word(struct xdr_buf *, unsigned int, u32);
185extern int xdr_decode_word(struct xdr_buf *, unsigned int, u32 *);
186
187struct xdr_array2_desc;
188typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem);
189struct xdr_array2_desc {
190 unsigned int elem_size;
191 unsigned int array_len;
192 unsigned int array_maxlen;
193 xdr_xcode_elem_t xcode;
194};
195
196extern int xdr_decode_array2(struct xdr_buf *buf, unsigned int base,
197 struct xdr_array2_desc *desc);
198extern int xdr_encode_array2(struct xdr_buf *buf, unsigned int base,
199 struct xdr_array2_desc *desc);
200extern void _copy_from_pages(char *p, struct page **pages, size_t pgbase,
201 size_t len);
202
203/*
204 * Provide some simple tools for XDR buffer overflow-checking etc.
205 */
206struct xdr_stream {
207 __be32 *p; /* start of available buffer */
208 struct xdr_buf *buf; /* XDR buffer to read/write */
209
210 __be32 *end; /* end of available buffer space */
211 struct kvec *iov; /* pointer to the current kvec */
212 struct kvec scratch; /* Scratch buffer */
213 struct page **page_ptr; /* pointer to the current page */
214 unsigned int nwords; /* Remaining decode buffer length */
215};
216
217/*
218 * These are the xdr_stream style generic XDR encode and decode functions.
219 */
220typedef void (*kxdreproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
221 const void *obj);
222typedef int (*kxdrdproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
223 void *obj);
224
225extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p);
226extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes);
227extern void xdr_commit_encode(struct xdr_stream *xdr);
228extern void xdr_truncate_encode(struct xdr_stream *xdr, size_t len);
229extern int xdr_restrict_buflen(struct xdr_stream *xdr, int newbuflen);
230extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages,
231 unsigned int base, unsigned int len);
232extern unsigned int xdr_stream_pos(const struct xdr_stream *xdr);
233extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p);
234extern void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf,
235 struct page **pages, unsigned int len);
236extern void xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen);
237extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes);
238extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len);
239extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);
240extern int xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);
241
242/**
243 * xdr_stream_remaining - Return the number of bytes remaining in the stream
244 * @xdr: pointer to struct xdr_stream
245 *
246 * Return value:
247 * Number of bytes remaining in @xdr before xdr->end
248 */
249static inline size_t
250xdr_stream_remaining(const struct xdr_stream *xdr)
251{
252 return xdr->nwords << 2;
253}
254
255ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str,
256 size_t maxlen, gfp_t gfp_flags);
257/**
258 * xdr_align_size - Calculate padded size of an object
259 * @n: Size of an object being XDR encoded (in bytes)
260 *
261 * Return value:
262 * Size (in bytes) of the object including xdr padding
263 */
264static inline size_t
265xdr_align_size(size_t n)
266{
267 const size_t mask = sizeof(__u32) - 1;
268
269 return (n + mask) & ~mask;
270}
271
272/**
273 * xdr_stream_encode_u32 - Encode a 32-bit integer
274 * @xdr: pointer to xdr_stream
275 * @n: integer to encode
276 *
277 * Return values:
278 * On success, returns length in bytes of XDR buffer consumed
279 * %-EMSGSIZE on XDR buffer overflow
280 */
281static inline ssize_t
282xdr_stream_encode_u32(struct xdr_stream *xdr, __u32 n)
283{
284 const size_t len = sizeof(n);
285 __be32 *p = xdr_reserve_space(xdr, len);
286
287 if (unlikely(!p))
288 return -EMSGSIZE;
289 *p = cpu_to_be32(n);
290 return len;
291}
292
293/**
294 * xdr_stream_encode_u64 - Encode a 64-bit integer
295 * @xdr: pointer to xdr_stream
296 * @n: 64-bit integer to encode
297 *
298 * Return values:
299 * On success, returns length in bytes of XDR buffer consumed
300 * %-EMSGSIZE on XDR buffer overflow
301 */
302static inline ssize_t
303xdr_stream_encode_u64(struct xdr_stream *xdr, __u64 n)
304{
305 const size_t len = sizeof(n);
306 __be32 *p = xdr_reserve_space(xdr, len);
307
308 if (unlikely(!p))
309 return -EMSGSIZE;
310 xdr_encode_hyper(p, n);
311 return len;
312}
313
314/**
315 * xdr_stream_encode_opaque_fixed - Encode fixed length opaque xdr data
316 * @xdr: pointer to xdr_stream
317 * @ptr: pointer to opaque data object
318 * @len: size of object pointed to by @ptr
319 *
320 * Return values:
321 * On success, returns length in bytes of XDR buffer consumed
322 * %-EMSGSIZE on XDR buffer overflow
323 */
324static inline ssize_t
325xdr_stream_encode_opaque_fixed(struct xdr_stream *xdr, const void *ptr, size_t len)
326{
327 __be32 *p = xdr_reserve_space(xdr, len);
328
329 if (unlikely(!p))
330 return -EMSGSIZE;
331 xdr_encode_opaque_fixed(p, ptr, len);
332 return xdr_align_size(len);
333}
334
335/**
336 * xdr_stream_encode_opaque - Encode variable length opaque xdr data
337 * @xdr: pointer to xdr_stream
338 * @ptr: pointer to opaque data object
339 * @len: size of object pointed to by @ptr
340 *
341 * Return values:
342 * On success, returns length in bytes of XDR buffer consumed
343 * %-EMSGSIZE on XDR buffer overflow
344 */
345static inline ssize_t
346xdr_stream_encode_opaque(struct xdr_stream *xdr, const void *ptr, size_t len)
347{
348 size_t count = sizeof(__u32) + xdr_align_size(len);
349 __be32 *p = xdr_reserve_space(xdr, count);
350
351 if (unlikely(!p))
352 return -EMSGSIZE;
353 xdr_encode_opaque(p, ptr, len);
354 return count;
355}
356
357/**
358 * xdr_stream_decode_u32 - Decode a 32-bit integer
359 * @xdr: pointer to xdr_stream
360 * @ptr: location to store integer
361 *
362 * Return values:
363 * %0 on success
364 * %-EBADMSG on XDR buffer overflow
365 */
366static inline ssize_t
367xdr_stream_decode_u32(struct xdr_stream *xdr, __u32 *ptr)
368{
369 const size_t count = sizeof(*ptr);
370 __be32 *p = xdr_inline_decode(xdr, count);
371
372 if (unlikely(!p))
373 return -EBADMSG;
374 *ptr = be32_to_cpup(p);
375 return 0;
376}
377
378/**
379 * xdr_stream_decode_opaque_fixed - Decode fixed length opaque xdr data
380 * @xdr: pointer to xdr_stream
381 * @ptr: location to store data
382 * @len: size of buffer pointed to by @ptr
383 *
384 * Return values:
385 * On success, returns size of object stored in @ptr
386 * %-EBADMSG on XDR buffer overflow
387 */
388static inline ssize_t
389xdr_stream_decode_opaque_fixed(struct xdr_stream *xdr, void *ptr, size_t len)
390{
391 __be32 *p = xdr_inline_decode(xdr, len);
392
393 if (unlikely(!p))
394 return -EBADMSG;
395 xdr_decode_opaque_fixed(p, ptr, len);
396 return len;
397}
398
399/**
400 * xdr_stream_decode_opaque_inline - Decode variable length opaque xdr data
401 * @xdr: pointer to xdr_stream
402 * @ptr: location to store pointer to opaque data
403 * @maxlen: maximum acceptable object size
404 *
405 * Note: the pointer stored in @ptr cannot be assumed valid after the XDR
406 * buffer has been destroyed, or even after calling xdr_inline_decode()
407 * on @xdr. It is therefore expected that the object it points to should
408 * be processed immediately.
409 *
410 * Return values:
411 * On success, returns size of object stored in *@ptr
412 * %-EBADMSG on XDR buffer overflow
413 * %-EMSGSIZE if the size of the object would exceed @maxlen
414 */
415static inline ssize_t
416xdr_stream_decode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t maxlen)
417{
418 __be32 *p;
419 __u32 len;
420
421 *ptr = NULL;
422 if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
423 return -EBADMSG;
424 if (len != 0) {
425 p = xdr_inline_decode(xdr, len);
426 if (unlikely(!p))
427 return -EBADMSG;
428 if (unlikely(len > maxlen))
429 return -EMSGSIZE;
430 *ptr = p;
431 }
432 return len;
433}
434#endif /* __KERNEL__ */
435
436#endif /* _SUNRPC_XDR_H_ */