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->bvec = NULL; 76 buf->pages = NULL; 77 buf->page_len = 0; 78 buf->flags = 0; 79 buf->len = 0; 80 buf->buflen = len; 81 } 82 83 /* 84 * pre-xdr'ed macros. 85 */ 86 87 #define xdr_zero cpu_to_be32(0) 88 #define xdr_one cpu_to_be32(1) 89 #define xdr_two cpu_to_be32(2) 90 91 #define rpc_success cpu_to_be32(RPC_SUCCESS) 92 #define rpc_prog_unavail cpu_to_be32(RPC_PROG_UNAVAIL) 93 #define rpc_prog_mismatch cpu_to_be32(RPC_PROG_MISMATCH) 94 #define rpc_proc_unavail cpu_to_be32(RPC_PROC_UNAVAIL) 95 #define rpc_garbage_args cpu_to_be32(RPC_GARBAGE_ARGS) 96 #define rpc_system_err cpu_to_be32(RPC_SYSTEM_ERR) 97 #define rpc_drop_reply cpu_to_be32(RPC_DROP_REPLY) 98 99 #define rpc_auth_ok cpu_to_be32(RPC_AUTH_OK) 100 #define rpc_autherr_badcred cpu_to_be32(RPC_AUTH_BADCRED) 101 #define rpc_autherr_rejectedcred cpu_to_be32(RPC_AUTH_REJECTEDCRED) 102 #define rpc_autherr_badverf cpu_to_be32(RPC_AUTH_BADVERF) 103 #define rpc_autherr_rejectedverf cpu_to_be32(RPC_AUTH_REJECTEDVERF) 104 #define rpc_autherr_tooweak cpu_to_be32(RPC_AUTH_TOOWEAK) 105 #define rpcsec_gsserr_credproblem cpu_to_be32(RPCSEC_GSS_CREDPROBLEM) 106 #define rpcsec_gsserr_ctxproblem cpu_to_be32(RPCSEC_GSS_CTXPROBLEM) 107 #define rpc_autherr_oldseqnum cpu_to_be32(101) 108 109 /* 110 * Miscellaneous XDR helper functions 111 */ 112 __be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int len); 113 __be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int len); 114 __be32 *xdr_encode_string(__be32 *p, const char *s); 115 __be32 *xdr_decode_string_inplace(__be32 *p, char **sp, unsigned int *lenp, 116 unsigned int maxlen); 117 __be32 *xdr_encode_netobj(__be32 *p, const struct xdr_netobj *); 118 __be32 *xdr_decode_netobj(__be32 *p, struct xdr_netobj *); 119 120 void xdr_inline_pages(struct xdr_buf *, unsigned int, 121 struct page **, unsigned int, unsigned int); 122 void xdr_terminate_string(struct xdr_buf *, const u32); 123 size_t xdr_buf_pagecount(struct xdr_buf *buf); 124 int xdr_alloc_bvec(struct xdr_buf *buf, gfp_t gfp); 125 void xdr_free_bvec(struct xdr_buf *buf); 126 127 static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len) 128 { 129 return xdr_encode_opaque(p, s, len); 130 } 131 132 /* 133 * Decode 64bit quantities (NFSv3 support) 134 */ 135 static inline __be32 * 136 xdr_encode_hyper(__be32 *p, __u64 val) 137 { 138 put_unaligned_be64(val, p); 139 return p + 2; 140 } 141 142 static inline __be32 * 143 xdr_decode_hyper(__be32 *p, __u64 *valp) 144 { 145 *valp = get_unaligned_be64(p); 146 return p + 2; 147 } 148 149 static inline __be32 * 150 xdr_decode_opaque_fixed(__be32 *p, void *ptr, unsigned int len) 151 { 152 memcpy(ptr, p, len); 153 return p + XDR_QUADLEN(len); 154 } 155 156 /* 157 * Adjust kvec to reflect end of xdr'ed data (RPC client XDR) 158 */ 159 static inline int 160 xdr_adjust_iovec(struct kvec *iov, __be32 *p) 161 { 162 return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base); 163 } 164 165 /* 166 * XDR buffer helper functions 167 */ 168 extern void xdr_shift_buf(struct xdr_buf *, size_t); 169 extern void xdr_buf_from_iov(struct kvec *, struct xdr_buf *); 170 extern int xdr_buf_subsegment(struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int); 171 extern void xdr_buf_trim(struct xdr_buf *, unsigned int); 172 extern int xdr_buf_read_netobj(struct xdr_buf *, struct xdr_netobj *, unsigned int); 173 extern int read_bytes_from_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int); 174 extern int write_bytes_to_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int); 175 176 /* 177 * Helper structure for copying from an sk_buff. 178 */ 179 struct xdr_skb_reader { 180 struct sk_buff *skb; 181 unsigned int offset; 182 size_t count; 183 __wsum csum; 184 }; 185 186 typedef size_t (*xdr_skb_read_actor)(struct xdr_skb_reader *desc, void *to, size_t len); 187 188 extern int csum_partial_copy_to_xdr(struct xdr_buf *, struct sk_buff *); 189 190 extern int xdr_encode_word(struct xdr_buf *, unsigned int, u32); 191 extern int xdr_decode_word(struct xdr_buf *, unsigned int, u32 *); 192 193 struct xdr_array2_desc; 194 typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem); 195 struct xdr_array2_desc { 196 unsigned int elem_size; 197 unsigned int array_len; 198 unsigned int array_maxlen; 199 xdr_xcode_elem_t xcode; 200 }; 201 202 extern int xdr_decode_array2(struct xdr_buf *buf, unsigned int base, 203 struct xdr_array2_desc *desc); 204 extern int xdr_encode_array2(struct xdr_buf *buf, unsigned int base, 205 struct xdr_array2_desc *desc); 206 extern void _copy_from_pages(char *p, struct page **pages, size_t pgbase, 207 size_t len); 208 209 /* 210 * Provide some simple tools for XDR buffer overflow-checking etc. 211 */ 212 struct xdr_stream { 213 __be32 *p; /* start of available buffer */ 214 struct xdr_buf *buf; /* XDR buffer to read/write */ 215 216 __be32 *end; /* end of available buffer space */ 217 struct kvec *iov; /* pointer to the current kvec */ 218 struct kvec scratch; /* Scratch buffer */ 219 struct page **page_ptr; /* pointer to the current page */ 220 unsigned int nwords; /* Remaining decode buffer length */ 221 }; 222 223 /* 224 * These are the xdr_stream style generic XDR encode and decode functions. 225 */ 226 typedef void (*kxdreproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr, 227 const void *obj); 228 typedef int (*kxdrdproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr, 229 void *obj); 230 231 extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p); 232 extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes); 233 extern void xdr_commit_encode(struct xdr_stream *xdr); 234 extern void xdr_truncate_encode(struct xdr_stream *xdr, size_t len); 235 extern int xdr_restrict_buflen(struct xdr_stream *xdr, int newbuflen); 236 extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages, 237 unsigned int base, unsigned int len); 238 extern unsigned int xdr_stream_pos(const struct xdr_stream *xdr); 239 extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p); 240 extern void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf, 241 struct page **pages, unsigned int len); 242 extern void xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen); 243 extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes); 244 extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len); 245 extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len); 246 extern int xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data); 247 248 /** 249 * xdr_stream_remaining - Return the number of bytes remaining in the stream 250 * @xdr: pointer to struct xdr_stream 251 * 252 * Return value: 253 * Number of bytes remaining in @xdr before xdr->end 254 */ 255 static inline size_t 256 xdr_stream_remaining(const struct xdr_stream *xdr) 257 { 258 return xdr->nwords << 2; 259 } 260 261 ssize_t xdr_stream_decode_opaque(struct xdr_stream *xdr, void *ptr, 262 size_t size); 263 ssize_t xdr_stream_decode_opaque_dup(struct xdr_stream *xdr, void **ptr, 264 size_t maxlen, gfp_t gfp_flags); 265 ssize_t xdr_stream_decode_string(struct xdr_stream *xdr, char *str, 266 size_t size); 267 ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str, 268 size_t maxlen, gfp_t gfp_flags); 269 /** 270 * xdr_align_size - Calculate padded size of an object 271 * @n: Size of an object being XDR encoded (in bytes) 272 * 273 * Return value: 274 * Size (in bytes) of the object including xdr padding 275 */ 276 static inline size_t 277 xdr_align_size(size_t n) 278 { 279 const size_t mask = sizeof(__u32) - 1; 280 281 return (n + mask) & ~mask; 282 } 283 284 /** 285 * xdr_stream_encode_u32 - Encode a 32-bit integer 286 * @xdr: pointer to xdr_stream 287 * @n: integer to encode 288 * 289 * Return values: 290 * On success, returns length in bytes of XDR buffer consumed 291 * %-EMSGSIZE on XDR buffer overflow 292 */ 293 static inline ssize_t 294 xdr_stream_encode_u32(struct xdr_stream *xdr, __u32 n) 295 { 296 const size_t len = sizeof(n); 297 __be32 *p = xdr_reserve_space(xdr, len); 298 299 if (unlikely(!p)) 300 return -EMSGSIZE; 301 *p = cpu_to_be32(n); 302 return len; 303 } 304 305 /** 306 * xdr_stream_encode_u64 - Encode a 64-bit integer 307 * @xdr: pointer to xdr_stream 308 * @n: 64-bit integer to encode 309 * 310 * Return values: 311 * On success, returns length in bytes of XDR buffer consumed 312 * %-EMSGSIZE on XDR buffer overflow 313 */ 314 static inline ssize_t 315 xdr_stream_encode_u64(struct xdr_stream *xdr, __u64 n) 316 { 317 const size_t len = sizeof(n); 318 __be32 *p = xdr_reserve_space(xdr, len); 319 320 if (unlikely(!p)) 321 return -EMSGSIZE; 322 xdr_encode_hyper(p, n); 323 return len; 324 } 325 326 /** 327 * xdr_stream_encode_opaque_inline - Encode opaque xdr data 328 * @xdr: pointer to xdr_stream 329 * @ptr: pointer to void pointer 330 * @len: size of object 331 * 332 * Return values: 333 * On success, returns length in bytes of XDR buffer consumed 334 * %-EMSGSIZE on XDR buffer overflow 335 */ 336 static inline ssize_t 337 xdr_stream_encode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t len) 338 { 339 size_t count = sizeof(__u32) + xdr_align_size(len); 340 __be32 *p = xdr_reserve_space(xdr, count); 341 342 if (unlikely(!p)) { 343 *ptr = NULL; 344 return -EMSGSIZE; 345 } 346 xdr_encode_opaque(p, NULL, len); 347 *ptr = ++p; 348 return count; 349 } 350 351 /** 352 * xdr_stream_encode_opaque_fixed - Encode fixed length opaque xdr data 353 * @xdr: pointer to xdr_stream 354 * @ptr: pointer to opaque data object 355 * @len: size of object pointed to by @ptr 356 * 357 * Return values: 358 * On success, returns length in bytes of XDR buffer consumed 359 * %-EMSGSIZE on XDR buffer overflow 360 */ 361 static inline ssize_t 362 xdr_stream_encode_opaque_fixed(struct xdr_stream *xdr, const void *ptr, size_t len) 363 { 364 __be32 *p = xdr_reserve_space(xdr, len); 365 366 if (unlikely(!p)) 367 return -EMSGSIZE; 368 xdr_encode_opaque_fixed(p, ptr, len); 369 return xdr_align_size(len); 370 } 371 372 /** 373 * xdr_stream_encode_opaque - Encode variable length opaque xdr data 374 * @xdr: pointer to xdr_stream 375 * @ptr: pointer to opaque data object 376 * @len: size of object pointed to by @ptr 377 * 378 * Return values: 379 * On success, returns length in bytes of XDR buffer consumed 380 * %-EMSGSIZE on XDR buffer overflow 381 */ 382 static inline ssize_t 383 xdr_stream_encode_opaque(struct xdr_stream *xdr, const void *ptr, size_t len) 384 { 385 size_t count = sizeof(__u32) + xdr_align_size(len); 386 __be32 *p = xdr_reserve_space(xdr, count); 387 388 if (unlikely(!p)) 389 return -EMSGSIZE; 390 xdr_encode_opaque(p, ptr, len); 391 return count; 392 } 393 394 /** 395 * xdr_stream_encode_uint32_array - Encode variable length array of integers 396 * @xdr: pointer to xdr_stream 397 * @array: array of integers 398 * @array_size: number of elements in @array 399 * 400 * Return values: 401 * On success, returns length in bytes of XDR buffer consumed 402 * %-EMSGSIZE on XDR buffer overflow 403 */ 404 static inline ssize_t 405 xdr_stream_encode_uint32_array(struct xdr_stream *xdr, 406 const __u32 *array, size_t array_size) 407 { 408 ssize_t ret = (array_size+1) * sizeof(__u32); 409 __be32 *p = xdr_reserve_space(xdr, ret); 410 411 if (unlikely(!p)) 412 return -EMSGSIZE; 413 *p++ = cpu_to_be32(array_size); 414 for (; array_size > 0; p++, array++, array_size--) 415 *p = cpu_to_be32p(array); 416 return ret; 417 } 418 419 /** 420 * xdr_stream_decode_u32 - Decode a 32-bit integer 421 * @xdr: pointer to xdr_stream 422 * @ptr: location to store integer 423 * 424 * Return values: 425 * %0 on success 426 * %-EBADMSG on XDR buffer overflow 427 */ 428 static inline ssize_t 429 xdr_stream_decode_u32(struct xdr_stream *xdr, __u32 *ptr) 430 { 431 const size_t count = sizeof(*ptr); 432 __be32 *p = xdr_inline_decode(xdr, count); 433 434 if (unlikely(!p)) 435 return -EBADMSG; 436 *ptr = be32_to_cpup(p); 437 return 0; 438 } 439 440 /** 441 * xdr_stream_decode_opaque_fixed - Decode fixed length opaque xdr data 442 * @xdr: pointer to xdr_stream 443 * @ptr: location to store data 444 * @len: size of buffer pointed to by @ptr 445 * 446 * Return values: 447 * On success, returns size of object stored in @ptr 448 * %-EBADMSG on XDR buffer overflow 449 */ 450 static inline ssize_t 451 xdr_stream_decode_opaque_fixed(struct xdr_stream *xdr, void *ptr, size_t len) 452 { 453 __be32 *p = xdr_inline_decode(xdr, len); 454 455 if (unlikely(!p)) 456 return -EBADMSG; 457 xdr_decode_opaque_fixed(p, ptr, len); 458 return len; 459 } 460 461 /** 462 * xdr_stream_decode_opaque_inline - Decode variable length opaque xdr data 463 * @xdr: pointer to xdr_stream 464 * @ptr: location to store pointer to opaque data 465 * @maxlen: maximum acceptable object size 466 * 467 * Note: the pointer stored in @ptr cannot be assumed valid after the XDR 468 * buffer has been destroyed, or even after calling xdr_inline_decode() 469 * on @xdr. It is therefore expected that the object it points to should 470 * be processed immediately. 471 * 472 * Return values: 473 * On success, returns size of object stored in *@ptr 474 * %-EBADMSG on XDR buffer overflow 475 * %-EMSGSIZE if the size of the object would exceed @maxlen 476 */ 477 static inline ssize_t 478 xdr_stream_decode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t maxlen) 479 { 480 __be32 *p; 481 __u32 len; 482 483 *ptr = NULL; 484 if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0)) 485 return -EBADMSG; 486 if (len != 0) { 487 p = xdr_inline_decode(xdr, len); 488 if (unlikely(!p)) 489 return -EBADMSG; 490 if (unlikely(len > maxlen)) 491 return -EMSGSIZE; 492 *ptr = p; 493 } 494 return len; 495 } 496 497 /** 498 * xdr_stream_decode_uint32_array - Decode variable length array of integers 499 * @xdr: pointer to xdr_stream 500 * @array: location to store the integer array or NULL 501 * @array_size: number of elements to store 502 * 503 * Return values: 504 * On success, returns number of elements stored in @array 505 * %-EBADMSG on XDR buffer overflow 506 * %-EMSGSIZE if the size of the array exceeds @array_size 507 */ 508 static inline ssize_t 509 xdr_stream_decode_uint32_array(struct xdr_stream *xdr, 510 __u32 *array, size_t array_size) 511 { 512 __be32 *p; 513 __u32 len; 514 ssize_t retval; 515 516 if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0)) 517 return -EBADMSG; 518 p = xdr_inline_decode(xdr, len * sizeof(*p)); 519 if (unlikely(!p)) 520 return -EBADMSG; 521 if (array == NULL) 522 return len; 523 if (len <= array_size) { 524 if (len < array_size) 525 memset(array+len, 0, (array_size-len)*sizeof(*array)); 526 array_size = len; 527 retval = len; 528 } else 529 retval = -EMSGSIZE; 530 for (; array_size > 0; p++, array++, array_size--) 531 *array = be32_to_cpup(p); 532 return retval; 533 } 534 #endif /* __KERNEL__ */ 535 536 #endif /* _SUNRPC_XDR_H_ */ 537