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 #include <linux/uio.h> 15 #include <asm/byteorder.h> 16 #include <asm/unaligned.h> 17 #include <linux/scatterlist.h> 18 19 struct bio_vec; 20 struct 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 32 struct 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 */ 50 struct xdr_buf { 51 struct kvec head[1], /* RPC header + non-page data */ 52 tail[1]; /* Appended after page data */ 53 54 struct bio_vec *bvec; 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 #define XDRBUF_SPARSE_PAGES 0x04 /* Page array is sparse */ 62 63 unsigned int buflen, /* Total length of storage buffer */ 64 len; /* Length of XDR encoded message */ 65 }; 66 67 static inline void 68 xdr_buf_init(struct xdr_buf *buf, void *start, size_t len) 69 { 70 buf->head[0].iov_base = start; 71 buf->head[0].iov_len = len; 72 buf->tail[0].iov_len = 0; 73 buf->pages = NULL; 74 buf->page_len = 0; 75 buf->flags = 0; 76 buf->len = 0; 77 buf->buflen = len; 78 } 79 80 /* 81 * pre-xdr'ed macros. 82 */ 83 84 #define xdr_zero cpu_to_be32(0) 85 #define xdr_one cpu_to_be32(1) 86 #define xdr_two cpu_to_be32(2) 87 88 #define rpc_auth_null cpu_to_be32(RPC_AUTH_NULL) 89 #define rpc_auth_unix cpu_to_be32(RPC_AUTH_UNIX) 90 #define rpc_auth_short cpu_to_be32(RPC_AUTH_SHORT) 91 #define rpc_auth_gss cpu_to_be32(RPC_AUTH_GSS) 92 93 #define rpc_call cpu_to_be32(RPC_CALL) 94 #define rpc_reply cpu_to_be32(RPC_REPLY) 95 96 #define rpc_msg_accepted cpu_to_be32(RPC_MSG_ACCEPTED) 97 98 #define rpc_success cpu_to_be32(RPC_SUCCESS) 99 #define rpc_prog_unavail cpu_to_be32(RPC_PROG_UNAVAIL) 100 #define rpc_prog_mismatch cpu_to_be32(RPC_PROG_MISMATCH) 101 #define rpc_proc_unavail cpu_to_be32(RPC_PROC_UNAVAIL) 102 #define rpc_garbage_args cpu_to_be32(RPC_GARBAGE_ARGS) 103 #define rpc_system_err cpu_to_be32(RPC_SYSTEM_ERR) 104 #define rpc_drop_reply cpu_to_be32(RPC_DROP_REPLY) 105 106 #define rpc_mismatch cpu_to_be32(RPC_MISMATCH) 107 #define rpc_auth_error cpu_to_be32(RPC_AUTH_ERROR) 108 109 #define rpc_auth_ok cpu_to_be32(RPC_AUTH_OK) 110 #define rpc_autherr_badcred cpu_to_be32(RPC_AUTH_BADCRED) 111 #define rpc_autherr_rejectedcred cpu_to_be32(RPC_AUTH_REJECTEDCRED) 112 #define rpc_autherr_badverf cpu_to_be32(RPC_AUTH_BADVERF) 113 #define rpc_autherr_rejectedverf cpu_to_be32(RPC_AUTH_REJECTEDVERF) 114 #define rpc_autherr_tooweak cpu_to_be32(RPC_AUTH_TOOWEAK) 115 #define rpcsec_gsserr_credproblem cpu_to_be32(RPCSEC_GSS_CREDPROBLEM) 116 #define rpcsec_gsserr_ctxproblem cpu_to_be32(RPCSEC_GSS_CTXPROBLEM) 117 118 /* 119 * Miscellaneous XDR helper functions 120 */ 121 __be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int len); 122 __be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int len); 123 __be32 *xdr_encode_string(__be32 *p, const char *s); 124 __be32 *xdr_decode_string_inplace(__be32 *p, char **sp, unsigned int *lenp, 125 unsigned int maxlen); 126 __be32 *xdr_encode_netobj(__be32 *p, const struct xdr_netobj *); 127 __be32 *xdr_decode_netobj(__be32 *p, struct xdr_netobj *); 128 129 void xdr_inline_pages(struct xdr_buf *, unsigned int, 130 struct page **, unsigned int, unsigned int); 131 void xdr_terminate_string(struct xdr_buf *, const u32); 132 size_t xdr_buf_pagecount(struct xdr_buf *buf); 133 int xdr_alloc_bvec(struct xdr_buf *buf, gfp_t gfp); 134 void xdr_free_bvec(struct xdr_buf *buf); 135 136 static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len) 137 { 138 return xdr_encode_opaque(p, s, len); 139 } 140 141 /* 142 * Decode 64bit quantities (NFSv3 support) 143 */ 144 static inline __be32 * 145 xdr_encode_hyper(__be32 *p, __u64 val) 146 { 147 put_unaligned_be64(val, p); 148 return p + 2; 149 } 150 151 static inline __be32 * 152 xdr_decode_hyper(__be32 *p, __u64 *valp) 153 { 154 *valp = get_unaligned_be64(p); 155 return p + 2; 156 } 157 158 static inline __be32 * 159 xdr_decode_opaque_fixed(__be32 *p, void *ptr, unsigned int len) 160 { 161 memcpy(ptr, p, len); 162 return p + XDR_QUADLEN(len); 163 } 164 165 static inline void xdr_netobj_dup(struct xdr_netobj *dst, 166 struct xdr_netobj *src, gfp_t gfp_mask) 167 { 168 dst->data = kmemdup(src->data, src->len, gfp_mask); 169 dst->len = src->len; 170 } 171 172 /* 173 * Adjust kvec to reflect end of xdr'ed data (RPC client XDR) 174 */ 175 static inline int 176 xdr_adjust_iovec(struct kvec *iov, __be32 *p) 177 { 178 return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base); 179 } 180 181 /* 182 * XDR buffer helper functions 183 */ 184 extern void xdr_shift_buf(struct xdr_buf *, size_t); 185 extern void xdr_buf_from_iov(struct kvec *, struct xdr_buf *); 186 extern int xdr_buf_subsegment(struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int); 187 extern void xdr_buf_trim(struct xdr_buf *, unsigned int); 188 extern int read_bytes_from_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int); 189 extern int write_bytes_to_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int); 190 191 extern int xdr_encode_word(struct xdr_buf *, unsigned int, u32); 192 extern int xdr_decode_word(struct xdr_buf *, unsigned int, u32 *); 193 194 struct xdr_array2_desc; 195 typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem); 196 struct xdr_array2_desc { 197 unsigned int elem_size; 198 unsigned int array_len; 199 unsigned int array_maxlen; 200 xdr_xcode_elem_t xcode; 201 }; 202 203 extern int xdr_decode_array2(struct xdr_buf *buf, unsigned int base, 204 struct xdr_array2_desc *desc); 205 extern int xdr_encode_array2(struct xdr_buf *buf, unsigned int base, 206 struct xdr_array2_desc *desc); 207 extern void _copy_from_pages(char *p, struct page **pages, size_t pgbase, 208 size_t len); 209 210 /* 211 * Provide some simple tools for XDR buffer overflow-checking etc. 212 */ 213 struct xdr_stream { 214 __be32 *p; /* start of available buffer */ 215 struct xdr_buf *buf; /* XDR buffer to read/write */ 216 217 __be32 *end; /* end of available buffer space */ 218 struct kvec *iov; /* pointer to the current kvec */ 219 struct kvec scratch; /* Scratch buffer */ 220 struct page **page_ptr; /* pointer to the current page */ 221 unsigned int nwords; /* Remaining decode buffer length */ 222 223 struct rpc_rqst *rqst; /* For debugging */ 224 }; 225 226 /* 227 * These are the xdr_stream style generic XDR encode and decode functions. 228 */ 229 typedef void (*kxdreproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr, 230 const void *obj); 231 typedef int (*kxdrdproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr, 232 void *obj); 233 234 extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, 235 __be32 *p, struct rpc_rqst *rqst); 236 extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes); 237 extern void xdr_commit_encode(struct xdr_stream *xdr); 238 extern void xdr_truncate_encode(struct xdr_stream *xdr, size_t len); 239 extern int xdr_restrict_buflen(struct xdr_stream *xdr, int newbuflen); 240 extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages, 241 unsigned int base, unsigned int len); 242 extern unsigned int xdr_stream_pos(const struct xdr_stream *xdr); 243 extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, 244 __be32 *p, struct rpc_rqst *rqst); 245 extern void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf, 246 struct page **pages, unsigned int len); 247 extern void xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen); 248 extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes); 249 extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len); 250 extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len); 251 extern int xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data); 252 253 /** 254 * xdr_stream_remaining - Return the number of bytes remaining in the stream 255 * @xdr: pointer to struct xdr_stream 256 * 257 * Return value: 258 * Number of bytes remaining in @xdr before xdr->end 259 */ 260 static inline size_t 261 xdr_stream_remaining(const struct xdr_stream *xdr) 262 { 263 return xdr->nwords << 2; 264 } 265 266 ssize_t xdr_stream_decode_opaque(struct xdr_stream *xdr, void *ptr, 267 size_t size); 268 ssize_t xdr_stream_decode_opaque_dup(struct xdr_stream *xdr, void **ptr, 269 size_t maxlen, gfp_t gfp_flags); 270 ssize_t xdr_stream_decode_string(struct xdr_stream *xdr, char *str, 271 size_t size); 272 ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str, 273 size_t maxlen, gfp_t gfp_flags); 274 /** 275 * xdr_align_size - Calculate padded size of an object 276 * @n: Size of an object being XDR encoded (in bytes) 277 * 278 * Return value: 279 * Size (in bytes) of the object including xdr padding 280 */ 281 static inline size_t 282 xdr_align_size(size_t n) 283 { 284 const size_t mask = sizeof(__u32) - 1; 285 286 return (n + mask) & ~mask; 287 } 288 289 /** 290 * xdr_pad_size - Calculate size of an object's pad 291 * @n: Size of an object being XDR encoded (in bytes) 292 * 293 * This implementation avoids the need for conditional 294 * branches or modulo division. 295 * 296 * Return value: 297 * Size (in bytes) of the needed XDR pad 298 */ 299 static inline size_t xdr_pad_size(size_t n) 300 { 301 return xdr_align_size(n) - n; 302 } 303 304 /** 305 * xdr_stream_encode_item_present - Encode a "present" list item 306 * @xdr: pointer to xdr_stream 307 * 308 * Return values: 309 * On success, returns length in bytes of XDR buffer consumed 310 * %-EMSGSIZE on XDR buffer overflow 311 */ 312 static inline ssize_t xdr_stream_encode_item_present(struct xdr_stream *xdr) 313 { 314 const size_t len = sizeof(__be32); 315 __be32 *p = xdr_reserve_space(xdr, len); 316 317 if (unlikely(!p)) 318 return -EMSGSIZE; 319 *p = xdr_one; 320 return len; 321 } 322 323 /** 324 * xdr_stream_encode_item_absent - Encode a "not present" list item 325 * @xdr: pointer to xdr_stream 326 * 327 * Return values: 328 * On success, returns length in bytes of XDR buffer consumed 329 * %-EMSGSIZE on XDR buffer overflow 330 */ 331 static inline int xdr_stream_encode_item_absent(struct xdr_stream *xdr) 332 { 333 const size_t len = sizeof(__be32); 334 __be32 *p = xdr_reserve_space(xdr, len); 335 336 if (unlikely(!p)) 337 return -EMSGSIZE; 338 *p = xdr_zero; 339 return len; 340 } 341 342 /** 343 * xdr_stream_encode_u32 - Encode a 32-bit integer 344 * @xdr: pointer to xdr_stream 345 * @n: integer to encode 346 * 347 * Return values: 348 * On success, returns length in bytes of XDR buffer consumed 349 * %-EMSGSIZE on XDR buffer overflow 350 */ 351 static inline ssize_t 352 xdr_stream_encode_u32(struct xdr_stream *xdr, __u32 n) 353 { 354 const size_t len = sizeof(n); 355 __be32 *p = xdr_reserve_space(xdr, len); 356 357 if (unlikely(!p)) 358 return -EMSGSIZE; 359 *p = cpu_to_be32(n); 360 return len; 361 } 362 363 /** 364 * xdr_stream_encode_u64 - Encode a 64-bit integer 365 * @xdr: pointer to xdr_stream 366 * @n: 64-bit integer to encode 367 * 368 * Return values: 369 * On success, returns length in bytes of XDR buffer consumed 370 * %-EMSGSIZE on XDR buffer overflow 371 */ 372 static inline ssize_t 373 xdr_stream_encode_u64(struct xdr_stream *xdr, __u64 n) 374 { 375 const size_t len = sizeof(n); 376 __be32 *p = xdr_reserve_space(xdr, len); 377 378 if (unlikely(!p)) 379 return -EMSGSIZE; 380 xdr_encode_hyper(p, n); 381 return len; 382 } 383 384 /** 385 * xdr_stream_encode_opaque_inline - Encode opaque xdr data 386 * @xdr: pointer to xdr_stream 387 * @ptr: pointer to void pointer 388 * @len: size of object 389 * 390 * Return values: 391 * On success, returns length in bytes of XDR buffer consumed 392 * %-EMSGSIZE on XDR buffer overflow 393 */ 394 static inline ssize_t 395 xdr_stream_encode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t len) 396 { 397 size_t count = sizeof(__u32) + xdr_align_size(len); 398 __be32 *p = xdr_reserve_space(xdr, count); 399 400 if (unlikely(!p)) { 401 *ptr = NULL; 402 return -EMSGSIZE; 403 } 404 xdr_encode_opaque(p, NULL, len); 405 *ptr = ++p; 406 return count; 407 } 408 409 /** 410 * xdr_stream_encode_opaque_fixed - Encode fixed length opaque xdr data 411 * @xdr: pointer to xdr_stream 412 * @ptr: pointer to opaque data object 413 * @len: size of object pointed to by @ptr 414 * 415 * Return values: 416 * On success, returns length in bytes of XDR buffer consumed 417 * %-EMSGSIZE on XDR buffer overflow 418 */ 419 static inline ssize_t 420 xdr_stream_encode_opaque_fixed(struct xdr_stream *xdr, const void *ptr, size_t len) 421 { 422 __be32 *p = xdr_reserve_space(xdr, len); 423 424 if (unlikely(!p)) 425 return -EMSGSIZE; 426 xdr_encode_opaque_fixed(p, ptr, len); 427 return xdr_align_size(len); 428 } 429 430 /** 431 * xdr_stream_encode_opaque - Encode variable length opaque xdr data 432 * @xdr: pointer to xdr_stream 433 * @ptr: pointer to opaque data object 434 * @len: size of object pointed to by @ptr 435 * 436 * Return values: 437 * On success, returns length in bytes of XDR buffer consumed 438 * %-EMSGSIZE on XDR buffer overflow 439 */ 440 static inline ssize_t 441 xdr_stream_encode_opaque(struct xdr_stream *xdr, const void *ptr, size_t len) 442 { 443 size_t count = sizeof(__u32) + xdr_align_size(len); 444 __be32 *p = xdr_reserve_space(xdr, count); 445 446 if (unlikely(!p)) 447 return -EMSGSIZE; 448 xdr_encode_opaque(p, ptr, len); 449 return count; 450 } 451 452 /** 453 * xdr_stream_encode_uint32_array - Encode variable length array of integers 454 * @xdr: pointer to xdr_stream 455 * @array: array of integers 456 * @array_size: number of elements in @array 457 * 458 * Return values: 459 * On success, returns length in bytes of XDR buffer consumed 460 * %-EMSGSIZE on XDR buffer overflow 461 */ 462 static inline ssize_t 463 xdr_stream_encode_uint32_array(struct xdr_stream *xdr, 464 const __u32 *array, size_t array_size) 465 { 466 ssize_t ret = (array_size+1) * sizeof(__u32); 467 __be32 *p = xdr_reserve_space(xdr, ret); 468 469 if (unlikely(!p)) 470 return -EMSGSIZE; 471 *p++ = cpu_to_be32(array_size); 472 for (; array_size > 0; p++, array++, array_size--) 473 *p = cpu_to_be32p(array); 474 return ret; 475 } 476 477 /** 478 * xdr_stream_decode_u32 - Decode a 32-bit integer 479 * @xdr: pointer to xdr_stream 480 * @ptr: location to store integer 481 * 482 * Return values: 483 * %0 on success 484 * %-EBADMSG on XDR buffer overflow 485 */ 486 static inline ssize_t 487 xdr_stream_decode_u32(struct xdr_stream *xdr, __u32 *ptr) 488 { 489 const size_t count = sizeof(*ptr); 490 __be32 *p = xdr_inline_decode(xdr, count); 491 492 if (unlikely(!p)) 493 return -EBADMSG; 494 *ptr = be32_to_cpup(p); 495 return 0; 496 } 497 498 /** 499 * xdr_stream_decode_opaque_fixed - Decode fixed length opaque xdr data 500 * @xdr: pointer to xdr_stream 501 * @ptr: location to store data 502 * @len: size of buffer pointed to by @ptr 503 * 504 * Return values: 505 * On success, returns size of object stored in @ptr 506 * %-EBADMSG on XDR buffer overflow 507 */ 508 static inline ssize_t 509 xdr_stream_decode_opaque_fixed(struct xdr_stream *xdr, void *ptr, size_t len) 510 { 511 __be32 *p = xdr_inline_decode(xdr, len); 512 513 if (unlikely(!p)) 514 return -EBADMSG; 515 xdr_decode_opaque_fixed(p, ptr, len); 516 return len; 517 } 518 519 /** 520 * xdr_stream_decode_opaque_inline - Decode variable length opaque xdr data 521 * @xdr: pointer to xdr_stream 522 * @ptr: location to store pointer to opaque data 523 * @maxlen: maximum acceptable object size 524 * 525 * Note: the pointer stored in @ptr cannot be assumed valid after the XDR 526 * buffer has been destroyed, or even after calling xdr_inline_decode() 527 * on @xdr. It is therefore expected that the object it points to should 528 * be processed immediately. 529 * 530 * Return values: 531 * On success, returns size of object stored in *@ptr 532 * %-EBADMSG on XDR buffer overflow 533 * %-EMSGSIZE if the size of the object would exceed @maxlen 534 */ 535 static inline ssize_t 536 xdr_stream_decode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t maxlen) 537 { 538 __be32 *p; 539 __u32 len; 540 541 *ptr = NULL; 542 if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0)) 543 return -EBADMSG; 544 if (len != 0) { 545 p = xdr_inline_decode(xdr, len); 546 if (unlikely(!p)) 547 return -EBADMSG; 548 if (unlikely(len > maxlen)) 549 return -EMSGSIZE; 550 *ptr = p; 551 } 552 return len; 553 } 554 555 /** 556 * xdr_stream_decode_uint32_array - Decode variable length array of integers 557 * @xdr: pointer to xdr_stream 558 * @array: location to store the integer array or NULL 559 * @array_size: number of elements to store 560 * 561 * Return values: 562 * On success, returns number of elements stored in @array 563 * %-EBADMSG on XDR buffer overflow 564 * %-EMSGSIZE if the size of the array exceeds @array_size 565 */ 566 static inline ssize_t 567 xdr_stream_decode_uint32_array(struct xdr_stream *xdr, 568 __u32 *array, size_t array_size) 569 { 570 __be32 *p; 571 __u32 len; 572 ssize_t retval; 573 574 if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0)) 575 return -EBADMSG; 576 p = xdr_inline_decode(xdr, len * sizeof(*p)); 577 if (unlikely(!p)) 578 return -EBADMSG; 579 if (array == NULL) 580 return len; 581 if (len <= array_size) { 582 if (len < array_size) 583 memset(array+len, 0, (array_size-len)*sizeof(*array)); 584 array_size = len; 585 retval = len; 586 } else 587 retval = -EMSGSIZE; 588 for (; array_size > 0; p++, array++, array_size--) 589 *array = be32_to_cpup(p); 590 return retval; 591 } 592 593 #endif /* _SUNRPC_XDR_H_ */ 594