1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * XDR standard data types and function declarations 4 * 5 * Copyright (C) 1995-1997 Olaf Kirch <[email protected]> 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 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); 118 119 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 * 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 * 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 * 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 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 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 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 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 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 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 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 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 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 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