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 rpc_rqst;
22
23 /*
24 * Buffer adjustment
25 */
26 #define XDR_QUADLEN(l) (((l) + 3) >> 2)
27
28 /*
29 * Generic opaque `network object.' At the kernel level, this type
30 * is used only by lockd.
31 */
32 #define XDR_MAX_NETOBJ 1024
33 struct xdr_netobj {
34 unsigned int len;
35 u8 * data;
36 };
37
38 /*
39 * Basic structure for transmission/reception of a client XDR message.
40 * Features a header (for a linear buffer containing RPC headers
41 * and the data payload for short messages), and then an array of
42 * pages.
43 * The tail iovec allows you to append data after the page array. Its
44 * main interest is for appending padding to the pages in order to
45 * satisfy the int_32-alignment requirements in RFC1832.
46 *
47 * For the future, we might want to string several of these together
48 * in a list if anybody wants to make use of NFSv4 COMPOUND
49 * operations and/or has a need for scatter/gather involving pages.
50 */
51 struct xdr_buf {
52 struct kvec head[1], /* RPC header + non-page data */
53 tail[1]; /* Appended after page data */
54
55 struct page ** pages; /* Array of pages */
56 unsigned int page_base, /* Start of page data */
57 page_len, /* Length of page data */
58 flags; /* Flags for data disposition */
59 #define XDRBUF_READ 0x01 /* target of file read */
60 #define XDRBUF_WRITE 0x02 /* source of file write */
61
62 unsigned int buflen, /* Total length of storage buffer */
63 len; /* Length of XDR encoded message */
64 };
65
66 static inline void
xdr_buf_init(struct xdr_buf * buf,void * start,size_t len)67 xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
68 {
69 buf->head[0].iov_base = start;
70 buf->head[0].iov_len = len;
71 buf->tail[0].iov_len = 0;
72 buf->page_len = 0;
73 buf->flags = 0;
74 buf->len = 0;
75 buf->buflen = len;
76 }
77
78 /*
79 * pre-xdr'ed macros.
80 */
81
82 #define xdr_zero cpu_to_be32(0)
83 #define xdr_one cpu_to_be32(1)
84 #define xdr_two cpu_to_be32(2)
85
86 #define rpc_success cpu_to_be32(RPC_SUCCESS)
87 #define rpc_prog_unavail cpu_to_be32(RPC_PROG_UNAVAIL)
88 #define rpc_prog_mismatch cpu_to_be32(RPC_PROG_MISMATCH)
89 #define rpc_proc_unavail cpu_to_be32(RPC_PROC_UNAVAIL)
90 #define rpc_garbage_args cpu_to_be32(RPC_GARBAGE_ARGS)
91 #define rpc_system_err cpu_to_be32(RPC_SYSTEM_ERR)
92 #define rpc_drop_reply cpu_to_be32(RPC_DROP_REPLY)
93
94 #define rpc_auth_ok cpu_to_be32(RPC_AUTH_OK)
95 #define rpc_autherr_badcred cpu_to_be32(RPC_AUTH_BADCRED)
96 #define rpc_autherr_rejectedcred cpu_to_be32(RPC_AUTH_REJECTEDCRED)
97 #define rpc_autherr_badverf cpu_to_be32(RPC_AUTH_BADVERF)
98 #define rpc_autherr_rejectedverf cpu_to_be32(RPC_AUTH_REJECTEDVERF)
99 #define rpc_autherr_tooweak cpu_to_be32(RPC_AUTH_TOOWEAK)
100 #define rpcsec_gsserr_credproblem cpu_to_be32(RPCSEC_GSS_CREDPROBLEM)
101 #define rpcsec_gsserr_ctxproblem cpu_to_be32(RPCSEC_GSS_CTXPROBLEM)
102 #define rpc_autherr_oldseqnum cpu_to_be32(101)
103
104 /*
105 * Miscellaneous XDR helper functions
106 */
107 __be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int len);
108 __be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int len);
109 __be32 *xdr_encode_string(__be32 *p, const char *s);
110 __be32 *xdr_decode_string_inplace(__be32 *p, char **sp, unsigned int *lenp,
111 unsigned int maxlen);
112 __be32 *xdr_encode_netobj(__be32 *p, const struct xdr_netobj *);
113 __be32 *xdr_decode_netobj(__be32 *p, struct xdr_netobj *);
114
115 void xdr_inline_pages(struct xdr_buf *, unsigned int,
116 struct page **, unsigned int, unsigned int);
117 void xdr_terminate_string(struct xdr_buf *, const u32);
118
xdr_encode_array(__be32 * p,const void * s,unsigned int len)119 static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len)
120 {
121 return xdr_encode_opaque(p, s, len);
122 }
123
124 /*
125 * Decode 64bit quantities (NFSv3 support)
126 */
127 static inline __be32 *
xdr_encode_hyper(__be32 * p,__u64 val)128 xdr_encode_hyper(__be32 *p, __u64 val)
129 {
130 put_unaligned_be64(val, p);
131 return p + 2;
132 }
133
134 static inline __be32 *
xdr_decode_hyper(__be32 * p,__u64 * valp)135 xdr_decode_hyper(__be32 *p, __u64 *valp)
136 {
137 *valp = get_unaligned_be64(p);
138 return p + 2;
139 }
140
141 static inline __be32 *
xdr_decode_opaque_fixed(__be32 * p,void * ptr,unsigned int len)142 xdr_decode_opaque_fixed(__be32 *p, void *ptr, unsigned int len)
143 {
144 memcpy(ptr, p, len);
145 return p + XDR_QUADLEN(len);
146 }
147
148 /*
149 * Adjust kvec to reflect end of xdr'ed data (RPC client XDR)
150 */
151 static inline int
xdr_adjust_iovec(struct kvec * iov,__be32 * p)152 xdr_adjust_iovec(struct kvec *iov, __be32 *p)
153 {
154 return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base);
155 }
156
157 /*
158 * XDR buffer helper functions
159 */
160 extern void xdr_shift_buf(struct xdr_buf *, size_t);
161 extern void xdr_buf_from_iov(struct kvec *, struct xdr_buf *);
162 extern int xdr_buf_subsegment(struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int);
163 extern void xdr_buf_trim(struct xdr_buf *, unsigned int);
164 extern int xdr_buf_read_netobj(struct xdr_buf *, struct xdr_netobj *, unsigned int);
165 extern int read_bytes_from_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
166 extern int write_bytes_to_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
167
168 /*
169 * Helper structure for copying from an sk_buff.
170 */
171 struct xdr_skb_reader {
172 struct sk_buff *skb;
173 unsigned int offset;
174 size_t count;
175 __wsum csum;
176 };
177
178 typedef size_t (*xdr_skb_read_actor)(struct xdr_skb_reader *desc, void *to, size_t len);
179
180 size_t xdr_skb_read_bits(struct xdr_skb_reader *desc, void *to, size_t len);
181 extern int csum_partial_copy_to_xdr(struct xdr_buf *, struct sk_buff *);
182 extern ssize_t xdr_partial_copy_from_skb(struct xdr_buf *, unsigned int,
183 struct xdr_skb_reader *, xdr_skb_read_actor);
184
185 extern int xdr_encode_word(struct xdr_buf *, unsigned int, u32);
186 extern int xdr_decode_word(struct xdr_buf *, unsigned int, u32 *);
187
188 struct xdr_array2_desc;
189 typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem);
190 struct xdr_array2_desc {
191 unsigned int elem_size;
192 unsigned int array_len;
193 unsigned int array_maxlen;
194 xdr_xcode_elem_t xcode;
195 };
196
197 extern int xdr_decode_array2(struct xdr_buf *buf, unsigned int base,
198 struct xdr_array2_desc *desc);
199 extern int xdr_encode_array2(struct xdr_buf *buf, unsigned int base,
200 struct xdr_array2_desc *desc);
201 extern void _copy_from_pages(char *p, struct page **pages, size_t pgbase,
202 size_t len);
203
204 /*
205 * Provide some simple tools for XDR buffer overflow-checking etc.
206 */
207 struct xdr_stream {
208 __be32 *p; /* start of available buffer */
209 struct xdr_buf *buf; /* XDR buffer to read/write */
210
211 __be32 *end; /* end of available buffer space */
212 struct kvec *iov; /* pointer to the current kvec */
213 struct kvec scratch; /* Scratch buffer */
214 struct page **page_ptr; /* pointer to the current page */
215 unsigned int nwords; /* Remaining decode buffer length */
216 };
217
218 /*
219 * These are the xdr_stream style generic XDR encode and decode functions.
220 */
221 typedef void (*kxdreproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
222 const void *obj);
223 typedef int (*kxdrdproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
224 void *obj);
225
226 extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p);
227 extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes);
228 extern void xdr_commit_encode(struct xdr_stream *xdr);
229 extern void xdr_truncate_encode(struct xdr_stream *xdr, size_t len);
230 extern int xdr_restrict_buflen(struct xdr_stream *xdr, int newbuflen);
231 extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages,
232 unsigned int base, unsigned int len);
233 extern unsigned int xdr_stream_pos(const struct xdr_stream *xdr);
234 extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p);
235 extern void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf,
236 struct page **pages, unsigned int len);
237 extern void xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen);
238 extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes);
239 extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len);
240 extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);
241 extern int xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);
242
243 /**
244 * xdr_stream_remaining - Return the number of bytes remaining in the stream
245 * @xdr: pointer to struct xdr_stream
246 *
247 * Return value:
248 * Number of bytes remaining in @xdr before xdr->end
249 */
250 static inline size_t
xdr_stream_remaining(const struct xdr_stream * xdr)251 xdr_stream_remaining(const struct xdr_stream *xdr)
252 {
253 return xdr->nwords << 2;
254 }
255
256 ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str,
257 size_t maxlen, gfp_t gfp_flags);
258 /**
259 * xdr_align_size - Calculate padded size of an object
260 * @n: Size of an object being XDR encoded (in bytes)
261 *
262 * Return value:
263 * Size (in bytes) of the object including xdr padding
264 */
265 static inline size_t
xdr_align_size(size_t n)266 xdr_align_size(size_t n)
267 {
268 const size_t mask = sizeof(__u32) - 1;
269
270 return (n + mask) & ~mask;
271 }
272
273 /**
274 * xdr_stream_encode_u32 - Encode a 32-bit integer
275 * @xdr: pointer to xdr_stream
276 * @n: integer to encode
277 *
278 * Return values:
279 * On success, returns length in bytes of XDR buffer consumed
280 * %-EMSGSIZE on XDR buffer overflow
281 */
282 static inline ssize_t
xdr_stream_encode_u32(struct xdr_stream * xdr,__u32 n)283 xdr_stream_encode_u32(struct xdr_stream *xdr, __u32 n)
284 {
285 const size_t len = sizeof(n);
286 __be32 *p = xdr_reserve_space(xdr, len);
287
288 if (unlikely(!p))
289 return -EMSGSIZE;
290 *p = cpu_to_be32(n);
291 return len;
292 }
293
294 /**
295 * xdr_stream_encode_u64 - Encode a 64-bit integer
296 * @xdr: pointer to xdr_stream
297 * @n: 64-bit integer to encode
298 *
299 * Return values:
300 * On success, returns length in bytes of XDR buffer consumed
301 * %-EMSGSIZE on XDR buffer overflow
302 */
303 static inline ssize_t
xdr_stream_encode_u64(struct xdr_stream * xdr,__u64 n)304 xdr_stream_encode_u64(struct xdr_stream *xdr, __u64 n)
305 {
306 const size_t len = sizeof(n);
307 __be32 *p = xdr_reserve_space(xdr, len);
308
309 if (unlikely(!p))
310 return -EMSGSIZE;
311 xdr_encode_hyper(p, n);
312 return len;
313 }
314
315 /**
316 * xdr_stream_encode_opaque_fixed - Encode fixed length opaque xdr data
317 * @xdr: pointer to xdr_stream
318 * @ptr: pointer to opaque data object
319 * @len: size of object pointed to by @ptr
320 *
321 * Return values:
322 * On success, returns length in bytes of XDR buffer consumed
323 * %-EMSGSIZE on XDR buffer overflow
324 */
325 static inline ssize_t
xdr_stream_encode_opaque_fixed(struct xdr_stream * xdr,const void * ptr,size_t len)326 xdr_stream_encode_opaque_fixed(struct xdr_stream *xdr, const void *ptr, size_t len)
327 {
328 __be32 *p = xdr_reserve_space(xdr, len);
329
330 if (unlikely(!p))
331 return -EMSGSIZE;
332 xdr_encode_opaque_fixed(p, ptr, len);
333 return xdr_align_size(len);
334 }
335
336 /**
337 * xdr_stream_encode_opaque - Encode variable length opaque xdr data
338 * @xdr: pointer to xdr_stream
339 * @ptr: pointer to opaque data object
340 * @len: size of object pointed to by @ptr
341 *
342 * Return values:
343 * On success, returns length in bytes of XDR buffer consumed
344 * %-EMSGSIZE on XDR buffer overflow
345 */
346 static inline ssize_t
xdr_stream_encode_opaque(struct xdr_stream * xdr,const void * ptr,size_t len)347 xdr_stream_encode_opaque(struct xdr_stream *xdr, const void *ptr, size_t len)
348 {
349 size_t count = sizeof(__u32) + xdr_align_size(len);
350 __be32 *p = xdr_reserve_space(xdr, count);
351
352 if (unlikely(!p))
353 return -EMSGSIZE;
354 xdr_encode_opaque(p, ptr, len);
355 return count;
356 }
357
358 /**
359 * xdr_stream_decode_u32 - Decode a 32-bit integer
360 * @xdr: pointer to xdr_stream
361 * @ptr: location to store integer
362 *
363 * Return values:
364 * %0 on success
365 * %-EBADMSG on XDR buffer overflow
366 */
367 static inline ssize_t
xdr_stream_decode_u32(struct xdr_stream * xdr,__u32 * ptr)368 xdr_stream_decode_u32(struct xdr_stream *xdr, __u32 *ptr)
369 {
370 const size_t count = sizeof(*ptr);
371 __be32 *p = xdr_inline_decode(xdr, count);
372
373 if (unlikely(!p))
374 return -EBADMSG;
375 *ptr = be32_to_cpup(p);
376 return 0;
377 }
378
379 /**
380 * xdr_stream_decode_opaque_fixed - Decode fixed length opaque xdr data
381 * @xdr: pointer to xdr_stream
382 * @ptr: location to store data
383 * @len: size of buffer pointed to by @ptr
384 *
385 * Return values:
386 * On success, returns size of object stored in @ptr
387 * %-EBADMSG on XDR buffer overflow
388 */
389 static inline ssize_t
xdr_stream_decode_opaque_fixed(struct xdr_stream * xdr,void * ptr,size_t len)390 xdr_stream_decode_opaque_fixed(struct xdr_stream *xdr, void *ptr, size_t len)
391 {
392 __be32 *p = xdr_inline_decode(xdr, len);
393
394 if (unlikely(!p))
395 return -EBADMSG;
396 xdr_decode_opaque_fixed(p, ptr, len);
397 return len;
398 }
399
400 /**
401 * xdr_stream_decode_opaque_inline - Decode variable length opaque xdr data
402 * @xdr: pointer to xdr_stream
403 * @ptr: location to store pointer to opaque data
404 * @maxlen: maximum acceptable object size
405 *
406 * Note: the pointer stored in @ptr cannot be assumed valid after the XDR
407 * buffer has been destroyed, or even after calling xdr_inline_decode()
408 * on @xdr. It is therefore expected that the object it points to should
409 * be processed immediately.
410 *
411 * Return values:
412 * On success, returns size of object stored in *@ptr
413 * %-EBADMSG on XDR buffer overflow
414 * %-EMSGSIZE if the size of the object would exceed @maxlen
415 */
416 static inline ssize_t
xdr_stream_decode_opaque_inline(struct xdr_stream * xdr,void ** ptr,size_t maxlen)417 xdr_stream_decode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t maxlen)
418 {
419 __be32 *p;
420 __u32 len;
421
422 *ptr = NULL;
423 if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
424 return -EBADMSG;
425 if (len != 0) {
426 p = xdr_inline_decode(xdr, len);
427 if (unlikely(!p))
428 return -EBADMSG;
429 if (unlikely(len > maxlen))
430 return -EMSGSIZE;
431 *ptr = p;
432 }
433 return len;
434 }
435 #endif /* __KERNEL__ */
436
437 #endif /* _SUNRPC_XDR_H_ */
438