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 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_success cpu_to_be32(RPC_SUCCESS) 91 #define rpc_prog_unavail cpu_to_be32(RPC_PROG_UNAVAIL) 92 #define rpc_prog_mismatch cpu_to_be32(RPC_PROG_MISMATCH) 93 #define rpc_proc_unavail cpu_to_be32(RPC_PROC_UNAVAIL) 94 #define rpc_garbage_args cpu_to_be32(RPC_GARBAGE_ARGS) 95 #define rpc_system_err cpu_to_be32(RPC_SYSTEM_ERR) 96 #define rpc_drop_reply cpu_to_be32(RPC_DROP_REPLY) 97 98 #define rpc_auth_ok cpu_to_be32(RPC_AUTH_OK) 99 #define rpc_autherr_badcred cpu_to_be32(RPC_AUTH_BADCRED) 100 #define rpc_autherr_rejectedcred cpu_to_be32(RPC_AUTH_REJECTEDCRED) 101 #define rpc_autherr_badverf cpu_to_be32(RPC_AUTH_BADVERF) 102 #define rpc_autherr_rejectedverf cpu_to_be32(RPC_AUTH_REJECTEDVERF) 103 #define rpc_autherr_tooweak cpu_to_be32(RPC_AUTH_TOOWEAK) 104 #define rpcsec_gsserr_credproblem cpu_to_be32(RPCSEC_GSS_CREDPROBLEM) 105 #define rpcsec_gsserr_ctxproblem cpu_to_be32(RPCSEC_GSS_CTXPROBLEM) 106 #define rpc_autherr_oldseqnum cpu_to_be32(101) 107 108 /* 109 * Miscellaneous XDR helper functions 110 */ 111 __be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int len); 112 __be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int len); 113 __be32 *xdr_encode_string(__be32 *p, const char *s); 114 __be32 *xdr_decode_string_inplace(__be32 *p, char **sp, unsigned int *lenp, 115 unsigned int maxlen); 116 __be32 *xdr_encode_netobj(__be32 *p, const struct xdr_netobj *); 117 __be32 *xdr_decode_netobj(__be32 *p, struct xdr_netobj *); 118 119 void xdr_inline_pages(struct xdr_buf *, unsigned int, 120 struct page **, unsigned int, unsigned int); 121 void xdr_terminate_string(struct xdr_buf *, const u32); 122 size_t xdr_buf_pagecount(struct xdr_buf *buf); 123 int xdr_alloc_bvec(struct xdr_buf *buf, gfp_t gfp); 124 void xdr_free_bvec(struct xdr_buf *buf); 125 126 static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len) 127 { 128 return xdr_encode_opaque(p, s, len); 129 } 130 131 /* 132 * Decode 64bit quantities (NFSv3 support) 133 */ 134 static inline __be32 * 135 xdr_encode_hyper(__be32 *p, __u64 val) 136 { 137 put_unaligned_be64(val, p); 138 return p + 2; 139 } 140 141 static inline __be32 * 142 xdr_decode_hyper(__be32 *p, __u64 *valp) 143 { 144 *valp = get_unaligned_be64(p); 145 return p + 2; 146 } 147 148 static inline __be32 * 149 xdr_decode_opaque_fixed(__be32 *p, void *ptr, unsigned int len) 150 { 151 memcpy(ptr, p, len); 152 return p + XDR_QUADLEN(len); 153 } 154 155 /* 156 * Adjust kvec to reflect end of xdr'ed data (RPC client XDR) 157 */ 158 static inline int 159 xdr_adjust_iovec(struct kvec *iov, __be32 *p) 160 { 161 return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base); 162 } 163 164 /* 165 * XDR buffer helper functions 166 */ 167 extern void xdr_shift_buf(struct xdr_buf *, size_t); 168 extern void xdr_buf_from_iov(struct kvec *, struct xdr_buf *); 169 extern int xdr_buf_subsegment(struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int); 170 extern void xdr_buf_trim(struct xdr_buf *, unsigned int); 171 extern int xdr_buf_read_netobj(struct xdr_buf *, struct xdr_netobj *, unsigned int); 172 extern int read_bytes_from_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int); 173 extern int write_bytes_to_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int); 174 175 /* 176 * Helper structure for copying from an sk_buff. 177 */ 178 struct xdr_skb_reader { 179 struct sk_buff *skb; 180 unsigned int offset; 181 size_t count; 182 __wsum csum; 183 }; 184 185 typedef size_t (*xdr_skb_read_actor)(struct xdr_skb_reader *desc, void *to, size_t len); 186 187 extern int csum_partial_copy_to_xdr(struct xdr_buf *, struct sk_buff *); 188 189 extern int xdr_encode_word(struct xdr_buf *, unsigned int, u32); 190 extern int xdr_decode_word(struct xdr_buf *, unsigned int, u32 *); 191 192 struct xdr_array2_desc; 193 typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem); 194 struct xdr_array2_desc { 195 unsigned int elem_size; 196 unsigned int array_len; 197 unsigned int array_maxlen; 198 xdr_xcode_elem_t xcode; 199 }; 200 201 extern int xdr_decode_array2(struct xdr_buf *buf, unsigned int base, 202 struct xdr_array2_desc *desc); 203 extern int xdr_encode_array2(struct xdr_buf *buf, unsigned int base, 204 struct xdr_array2_desc *desc); 205 extern void _copy_from_pages(char *p, struct page **pages, size_t pgbase, 206 size_t len); 207 208 /* 209 * Provide some simple tools for XDR buffer overflow-checking etc. 210 */ 211 struct xdr_stream { 212 __be32 *p; /* start of available buffer */ 213 struct xdr_buf *buf; /* XDR buffer to read/write */ 214 215 __be32 *end; /* end of available buffer space */ 216 struct kvec *iov; /* pointer to the current kvec */ 217 struct kvec scratch; /* Scratch buffer */ 218 struct page **page_ptr; /* pointer to the current page */ 219 unsigned int nwords; /* Remaining decode buffer length */ 220 }; 221 222 /* 223 * These are the xdr_stream style generic XDR encode and decode functions. 224 */ 225 typedef void (*kxdreproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr, 226 const void *obj); 227 typedef int (*kxdrdproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr, 228 void *obj); 229 230 extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p); 231 extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes); 232 extern void xdr_commit_encode(struct xdr_stream *xdr); 233 extern void xdr_truncate_encode(struct xdr_stream *xdr, size_t len); 234 extern int xdr_restrict_buflen(struct xdr_stream *xdr, int newbuflen); 235 extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages, 236 unsigned int base, unsigned int len); 237 extern unsigned int xdr_stream_pos(const struct xdr_stream *xdr); 238 extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p); 239 extern void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf, 240 struct page **pages, unsigned int len); 241 extern void xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen); 242 extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes); 243 extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len); 244 extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len); 245 extern int xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data); 246 247 /** 248 * xdr_stream_remaining - Return the number of bytes remaining in the stream 249 * @xdr: pointer to struct xdr_stream 250 * 251 * Return value: 252 * Number of bytes remaining in @xdr before xdr->end 253 */ 254 static inline size_t 255 xdr_stream_remaining(const struct xdr_stream *xdr) 256 { 257 return xdr->nwords << 2; 258 } 259 260 ssize_t xdr_stream_decode_opaque(struct xdr_stream *xdr, void *ptr, 261 size_t size); 262 ssize_t xdr_stream_decode_opaque_dup(struct xdr_stream *xdr, void **ptr, 263 size_t maxlen, gfp_t gfp_flags); 264 ssize_t xdr_stream_decode_string(struct xdr_stream *xdr, char *str, 265 size_t size); 266 ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str, 267 size_t maxlen, gfp_t gfp_flags); 268 /** 269 * xdr_align_size - Calculate padded size of an object 270 * @n: Size of an object being XDR encoded (in bytes) 271 * 272 * Return value: 273 * Size (in bytes) of the object including xdr padding 274 */ 275 static inline size_t 276 xdr_align_size(size_t n) 277 { 278 const size_t mask = sizeof(__u32) - 1; 279 280 return (n + mask) & ~mask; 281 } 282 283 /** 284 * xdr_stream_encode_u32 - Encode a 32-bit integer 285 * @xdr: pointer to xdr_stream 286 * @n: integer to encode 287 * 288 * Return values: 289 * On success, returns length in bytes of XDR buffer consumed 290 * %-EMSGSIZE on XDR buffer overflow 291 */ 292 static inline ssize_t 293 xdr_stream_encode_u32(struct xdr_stream *xdr, __u32 n) 294 { 295 const size_t len = sizeof(n); 296 __be32 *p = xdr_reserve_space(xdr, len); 297 298 if (unlikely(!p)) 299 return -EMSGSIZE; 300 *p = cpu_to_be32(n); 301 return len; 302 } 303 304 /** 305 * xdr_stream_encode_u64 - Encode a 64-bit integer 306 * @xdr: pointer to xdr_stream 307 * @n: 64-bit integer to encode 308 * 309 * Return values: 310 * On success, returns length in bytes of XDR buffer consumed 311 * %-EMSGSIZE on XDR buffer overflow 312 */ 313 static inline ssize_t 314 xdr_stream_encode_u64(struct xdr_stream *xdr, __u64 n) 315 { 316 const size_t len = sizeof(n); 317 __be32 *p = xdr_reserve_space(xdr, len); 318 319 if (unlikely(!p)) 320 return -EMSGSIZE; 321 xdr_encode_hyper(p, n); 322 return len; 323 } 324 325 /** 326 * xdr_stream_encode_opaque_inline - Encode opaque xdr data 327 * @xdr: pointer to xdr_stream 328 * @ptr: pointer to void pointer 329 * @len: size of object 330 * 331 * Return values: 332 * On success, returns length in bytes of XDR buffer consumed 333 * %-EMSGSIZE on XDR buffer overflow 334 */ 335 static inline ssize_t 336 xdr_stream_encode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t len) 337 { 338 size_t count = sizeof(__u32) + xdr_align_size(len); 339 __be32 *p = xdr_reserve_space(xdr, count); 340 341 if (unlikely(!p)) { 342 *ptr = NULL; 343 return -EMSGSIZE; 344 } 345 xdr_encode_opaque(p, NULL, len); 346 *ptr = ++p; 347 return count; 348 } 349 350 /** 351 * xdr_stream_encode_opaque_fixed - Encode fixed length opaque xdr data 352 * @xdr: pointer to xdr_stream 353 * @ptr: pointer to opaque data object 354 * @len: size of object pointed to by @ptr 355 * 356 * Return values: 357 * On success, returns length in bytes of XDR buffer consumed 358 * %-EMSGSIZE on XDR buffer overflow 359 */ 360 static inline ssize_t 361 xdr_stream_encode_opaque_fixed(struct xdr_stream *xdr, const void *ptr, size_t len) 362 { 363 __be32 *p = xdr_reserve_space(xdr, len); 364 365 if (unlikely(!p)) 366 return -EMSGSIZE; 367 xdr_encode_opaque_fixed(p, ptr, len); 368 return xdr_align_size(len); 369 } 370 371 /** 372 * xdr_stream_encode_opaque - Encode variable length opaque xdr data 373 * @xdr: pointer to xdr_stream 374 * @ptr: pointer to opaque data object 375 * @len: size of object pointed to by @ptr 376 * 377 * Return values: 378 * On success, returns length in bytes of XDR buffer consumed 379 * %-EMSGSIZE on XDR buffer overflow 380 */ 381 static inline ssize_t 382 xdr_stream_encode_opaque(struct xdr_stream *xdr, const void *ptr, size_t len) 383 { 384 size_t count = sizeof(__u32) + xdr_align_size(len); 385 __be32 *p = xdr_reserve_space(xdr, count); 386 387 if (unlikely(!p)) 388 return -EMSGSIZE; 389 xdr_encode_opaque(p, ptr, len); 390 return count; 391 } 392 393 /** 394 * xdr_stream_encode_uint32_array - Encode variable length array of integers 395 * @xdr: pointer to xdr_stream 396 * @array: array of integers 397 * @array_size: number of elements in @array 398 * 399 * Return values: 400 * On success, returns length in bytes of XDR buffer consumed 401 * %-EMSGSIZE on XDR buffer overflow 402 */ 403 static inline ssize_t 404 xdr_stream_encode_uint32_array(struct xdr_stream *xdr, 405 const __u32 *array, size_t array_size) 406 { 407 ssize_t ret = (array_size+1) * sizeof(__u32); 408 __be32 *p = xdr_reserve_space(xdr, ret); 409 410 if (unlikely(!p)) 411 return -EMSGSIZE; 412 *p++ = cpu_to_be32(array_size); 413 for (; array_size > 0; p++, array++, array_size--) 414 *p = cpu_to_be32p(array); 415 return ret; 416 } 417 418 /** 419 * xdr_stream_decode_u32 - Decode a 32-bit integer 420 * @xdr: pointer to xdr_stream 421 * @ptr: location to store integer 422 * 423 * Return values: 424 * %0 on success 425 * %-EBADMSG on XDR buffer overflow 426 */ 427 static inline ssize_t 428 xdr_stream_decode_u32(struct xdr_stream *xdr, __u32 *ptr) 429 { 430 const size_t count = sizeof(*ptr); 431 __be32 *p = xdr_inline_decode(xdr, count); 432 433 if (unlikely(!p)) 434 return -EBADMSG; 435 *ptr = be32_to_cpup(p); 436 return 0; 437 } 438 439 /** 440 * xdr_stream_decode_opaque_fixed - Decode fixed length opaque xdr data 441 * @xdr: pointer to xdr_stream 442 * @ptr: location to store data 443 * @len: size of buffer pointed to by @ptr 444 * 445 * Return values: 446 * On success, returns size of object stored in @ptr 447 * %-EBADMSG on XDR buffer overflow 448 */ 449 static inline ssize_t 450 xdr_stream_decode_opaque_fixed(struct xdr_stream *xdr, void *ptr, size_t len) 451 { 452 __be32 *p = xdr_inline_decode(xdr, len); 453 454 if (unlikely(!p)) 455 return -EBADMSG; 456 xdr_decode_opaque_fixed(p, ptr, len); 457 return len; 458 } 459 460 /** 461 * xdr_stream_decode_opaque_inline - Decode variable length opaque xdr data 462 * @xdr: pointer to xdr_stream 463 * @ptr: location to store pointer to opaque data 464 * @maxlen: maximum acceptable object size 465 * 466 * Note: the pointer stored in @ptr cannot be assumed valid after the XDR 467 * buffer has been destroyed, or even after calling xdr_inline_decode() 468 * on @xdr. It is therefore expected that the object it points to should 469 * be processed immediately. 470 * 471 * Return values: 472 * On success, returns size of object stored in *@ptr 473 * %-EBADMSG on XDR buffer overflow 474 * %-EMSGSIZE if the size of the object would exceed @maxlen 475 */ 476 static inline ssize_t 477 xdr_stream_decode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t maxlen) 478 { 479 __be32 *p; 480 __u32 len; 481 482 *ptr = NULL; 483 if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0)) 484 return -EBADMSG; 485 if (len != 0) { 486 p = xdr_inline_decode(xdr, len); 487 if (unlikely(!p)) 488 return -EBADMSG; 489 if (unlikely(len > maxlen)) 490 return -EMSGSIZE; 491 *ptr = p; 492 } 493 return len; 494 } 495 496 /** 497 * xdr_stream_decode_uint32_array - Decode variable length array of integers 498 * @xdr: pointer to xdr_stream 499 * @array: location to store the integer array or NULL 500 * @array_size: number of elements to store 501 * 502 * Return values: 503 * On success, returns number of elements stored in @array 504 * %-EBADMSG on XDR buffer overflow 505 * %-EMSGSIZE if the size of the array exceeds @array_size 506 */ 507 static inline ssize_t 508 xdr_stream_decode_uint32_array(struct xdr_stream *xdr, 509 __u32 *array, size_t array_size) 510 { 511 __be32 *p; 512 __u32 len; 513 ssize_t retval; 514 515 if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0)) 516 return -EBADMSG; 517 p = xdr_inline_decode(xdr, len * sizeof(*p)); 518 if (unlikely(!p)) 519 return -EBADMSG; 520 if (array == NULL) 521 return len; 522 if (len <= array_size) { 523 if (len < array_size) 524 memset(array+len, 0, (array_size-len)*sizeof(*array)); 525 array_size = len; 526 retval = len; 527 } else 528 retval = -EMSGSIZE; 529 for (; array_size > 0; p++, array++, array_size--) 530 *array = be32_to_cpup(p); 531 return retval; 532 } 533 #endif /* __KERNEL__ */ 534 535 #endif /* _SUNRPC_XDR_H_ */ 536