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 int read_bytes_from_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int); 188 extern int write_bytes_to_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int); 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 struct rpc_rqst *rqst; /* For debugging */ 223 }; 224 225 /* 226 * These are the xdr_stream style generic XDR encode and decode functions. 227 */ 228 typedef void (*kxdreproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr, 229 const void *obj); 230 typedef int (*kxdrdproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr, 231 void *obj); 232 233 extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, 234 __be32 *p, struct rpc_rqst *rqst); 235 extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes); 236 extern void xdr_commit_encode(struct xdr_stream *xdr); 237 extern void xdr_truncate_encode(struct xdr_stream *xdr, size_t len); 238 extern int xdr_restrict_buflen(struct xdr_stream *xdr, int newbuflen); 239 extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages, 240 unsigned int base, unsigned int len); 241 extern unsigned int xdr_stream_pos(const struct xdr_stream *xdr); 242 extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, 243 __be32 *p, struct rpc_rqst *rqst); 244 extern void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf, 245 struct page **pages, unsigned int len); 246 extern void xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen); 247 extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes); 248 extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len); 249 extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len); 250 extern int xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data); 251 252 /** 253 * xdr_stream_remaining - Return the number of bytes remaining in the stream 254 * @xdr: pointer to struct xdr_stream 255 * 256 * Return value: 257 * Number of bytes remaining in @xdr before xdr->end 258 */ 259 static inline size_t 260 xdr_stream_remaining(const struct xdr_stream *xdr) 261 { 262 return xdr->nwords << 2; 263 } 264 265 ssize_t xdr_stream_decode_opaque(struct xdr_stream *xdr, void *ptr, 266 size_t size); 267 ssize_t xdr_stream_decode_opaque_dup(struct xdr_stream *xdr, void **ptr, 268 size_t maxlen, gfp_t gfp_flags); 269 ssize_t xdr_stream_decode_string(struct xdr_stream *xdr, char *str, 270 size_t size); 271 ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str, 272 size_t maxlen, gfp_t gfp_flags); 273 /** 274 * xdr_align_size - Calculate padded size of an object 275 * @n: Size of an object being XDR encoded (in bytes) 276 * 277 * Return value: 278 * Size (in bytes) of the object including xdr padding 279 */ 280 static inline size_t 281 xdr_align_size(size_t n) 282 { 283 const size_t mask = sizeof(__u32) - 1; 284 285 return (n + mask) & ~mask; 286 } 287 288 /** 289 * xdr_pad_size - Calculate size of an object's pad 290 * @n: Size of an object being XDR encoded (in bytes) 291 * 292 * This implementation avoids the need for conditional 293 * branches or modulo division. 294 * 295 * Return value: 296 * Size (in bytes) of the needed XDR pad 297 */ 298 static inline size_t xdr_pad_size(size_t n) 299 { 300 return xdr_align_size(n) - n; 301 } 302 303 /** 304 * xdr_stream_encode_item_present - Encode a "present" list item 305 * @xdr: pointer to xdr_stream 306 * 307 * Return values: 308 * On success, returns length in bytes of XDR buffer consumed 309 * %-EMSGSIZE on XDR buffer overflow 310 */ 311 static inline ssize_t xdr_stream_encode_item_present(struct xdr_stream *xdr) 312 { 313 const size_t len = sizeof(__be32); 314 __be32 *p = xdr_reserve_space(xdr, len); 315 316 if (unlikely(!p)) 317 return -EMSGSIZE; 318 *p = xdr_one; 319 return len; 320 } 321 322 /** 323 * xdr_stream_encode_item_absent - Encode a "not present" list item 324 * @xdr: pointer to xdr_stream 325 * 326 * Return values: 327 * On success, returns length in bytes of XDR buffer consumed 328 * %-EMSGSIZE on XDR buffer overflow 329 */ 330 static inline int xdr_stream_encode_item_absent(struct xdr_stream *xdr) 331 { 332 const size_t len = sizeof(__be32); 333 __be32 *p = xdr_reserve_space(xdr, len); 334 335 if (unlikely(!p)) 336 return -EMSGSIZE; 337 *p = xdr_zero; 338 return len; 339 } 340 341 /** 342 * xdr_stream_encode_u32 - Encode a 32-bit integer 343 * @xdr: pointer to xdr_stream 344 * @n: integer to encode 345 * 346 * Return values: 347 * On success, returns length in bytes of XDR buffer consumed 348 * %-EMSGSIZE on XDR buffer overflow 349 */ 350 static inline ssize_t 351 xdr_stream_encode_u32(struct xdr_stream *xdr, __u32 n) 352 { 353 const size_t len = sizeof(n); 354 __be32 *p = xdr_reserve_space(xdr, len); 355 356 if (unlikely(!p)) 357 return -EMSGSIZE; 358 *p = cpu_to_be32(n); 359 return len; 360 } 361 362 /** 363 * xdr_stream_encode_u64 - Encode a 64-bit integer 364 * @xdr: pointer to xdr_stream 365 * @n: 64-bit integer to encode 366 * 367 * Return values: 368 * On success, returns length in bytes of XDR buffer consumed 369 * %-EMSGSIZE on XDR buffer overflow 370 */ 371 static inline ssize_t 372 xdr_stream_encode_u64(struct xdr_stream *xdr, __u64 n) 373 { 374 const size_t len = sizeof(n); 375 __be32 *p = xdr_reserve_space(xdr, len); 376 377 if (unlikely(!p)) 378 return -EMSGSIZE; 379 xdr_encode_hyper(p, n); 380 return len; 381 } 382 383 /** 384 * xdr_stream_encode_opaque_inline - Encode opaque xdr data 385 * @xdr: pointer to xdr_stream 386 * @ptr: pointer to void pointer 387 * @len: size of object 388 * 389 * Return values: 390 * On success, returns length in bytes of XDR buffer consumed 391 * %-EMSGSIZE on XDR buffer overflow 392 */ 393 static inline ssize_t 394 xdr_stream_encode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t len) 395 { 396 size_t count = sizeof(__u32) + xdr_align_size(len); 397 __be32 *p = xdr_reserve_space(xdr, count); 398 399 if (unlikely(!p)) { 400 *ptr = NULL; 401 return -EMSGSIZE; 402 } 403 xdr_encode_opaque(p, NULL, len); 404 *ptr = ++p; 405 return count; 406 } 407 408 /** 409 * xdr_stream_encode_opaque_fixed - Encode fixed length opaque xdr data 410 * @xdr: pointer to xdr_stream 411 * @ptr: pointer to opaque data object 412 * @len: size of object pointed to by @ptr 413 * 414 * Return values: 415 * On success, returns length in bytes of XDR buffer consumed 416 * %-EMSGSIZE on XDR buffer overflow 417 */ 418 static inline ssize_t 419 xdr_stream_encode_opaque_fixed(struct xdr_stream *xdr, const void *ptr, size_t len) 420 { 421 __be32 *p = xdr_reserve_space(xdr, len); 422 423 if (unlikely(!p)) 424 return -EMSGSIZE; 425 xdr_encode_opaque_fixed(p, ptr, len); 426 return xdr_align_size(len); 427 } 428 429 /** 430 * xdr_stream_encode_opaque - Encode variable length opaque xdr data 431 * @xdr: pointer to xdr_stream 432 * @ptr: pointer to opaque data object 433 * @len: size of object pointed to by @ptr 434 * 435 * Return values: 436 * On success, returns length in bytes of XDR buffer consumed 437 * %-EMSGSIZE on XDR buffer overflow 438 */ 439 static inline ssize_t 440 xdr_stream_encode_opaque(struct xdr_stream *xdr, const void *ptr, size_t len) 441 { 442 size_t count = sizeof(__u32) + xdr_align_size(len); 443 __be32 *p = xdr_reserve_space(xdr, count); 444 445 if (unlikely(!p)) 446 return -EMSGSIZE; 447 xdr_encode_opaque(p, ptr, len); 448 return count; 449 } 450 451 /** 452 * xdr_stream_encode_uint32_array - Encode variable length array of integers 453 * @xdr: pointer to xdr_stream 454 * @array: array of integers 455 * @array_size: number of elements in @array 456 * 457 * Return values: 458 * On success, returns length in bytes of XDR buffer consumed 459 * %-EMSGSIZE on XDR buffer overflow 460 */ 461 static inline ssize_t 462 xdr_stream_encode_uint32_array(struct xdr_stream *xdr, 463 const __u32 *array, size_t array_size) 464 { 465 ssize_t ret = (array_size+1) * sizeof(__u32); 466 __be32 *p = xdr_reserve_space(xdr, ret); 467 468 if (unlikely(!p)) 469 return -EMSGSIZE; 470 *p++ = cpu_to_be32(array_size); 471 for (; array_size > 0; p++, array++, array_size--) 472 *p = cpu_to_be32p(array); 473 return ret; 474 } 475 476 /** 477 * xdr_stream_decode_u32 - Decode a 32-bit integer 478 * @xdr: pointer to xdr_stream 479 * @ptr: location to store integer 480 * 481 * Return values: 482 * %0 on success 483 * %-EBADMSG on XDR buffer overflow 484 */ 485 static inline ssize_t 486 xdr_stream_decode_u32(struct xdr_stream *xdr, __u32 *ptr) 487 { 488 const size_t count = sizeof(*ptr); 489 __be32 *p = xdr_inline_decode(xdr, count); 490 491 if (unlikely(!p)) 492 return -EBADMSG; 493 *ptr = be32_to_cpup(p); 494 return 0; 495 } 496 497 /** 498 * xdr_stream_decode_opaque_fixed - Decode fixed length opaque xdr data 499 * @xdr: pointer to xdr_stream 500 * @ptr: location to store data 501 * @len: size of buffer pointed to by @ptr 502 * 503 * Return values: 504 * On success, returns size of object stored in @ptr 505 * %-EBADMSG on XDR buffer overflow 506 */ 507 static inline ssize_t 508 xdr_stream_decode_opaque_fixed(struct xdr_stream *xdr, void *ptr, size_t len) 509 { 510 __be32 *p = xdr_inline_decode(xdr, len); 511 512 if (unlikely(!p)) 513 return -EBADMSG; 514 xdr_decode_opaque_fixed(p, ptr, len); 515 return len; 516 } 517 518 /** 519 * xdr_stream_decode_opaque_inline - Decode variable length opaque xdr data 520 * @xdr: pointer to xdr_stream 521 * @ptr: location to store pointer to opaque data 522 * @maxlen: maximum acceptable object size 523 * 524 * Note: the pointer stored in @ptr cannot be assumed valid after the XDR 525 * buffer has been destroyed, or even after calling xdr_inline_decode() 526 * on @xdr. It is therefore expected that the object it points to should 527 * be processed immediately. 528 * 529 * Return values: 530 * On success, returns size of object stored in *@ptr 531 * %-EBADMSG on XDR buffer overflow 532 * %-EMSGSIZE if the size of the object would exceed @maxlen 533 */ 534 static inline ssize_t 535 xdr_stream_decode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t maxlen) 536 { 537 __be32 *p; 538 __u32 len; 539 540 *ptr = NULL; 541 if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0)) 542 return -EBADMSG; 543 if (len != 0) { 544 p = xdr_inline_decode(xdr, len); 545 if (unlikely(!p)) 546 return -EBADMSG; 547 if (unlikely(len > maxlen)) 548 return -EMSGSIZE; 549 *ptr = p; 550 } 551 return len; 552 } 553 554 /** 555 * xdr_stream_decode_uint32_array - Decode variable length array of integers 556 * @xdr: pointer to xdr_stream 557 * @array: location to store the integer array or NULL 558 * @array_size: number of elements to store 559 * 560 * Return values: 561 * On success, returns number of elements stored in @array 562 * %-EBADMSG on XDR buffer overflow 563 * %-EMSGSIZE if the size of the array exceeds @array_size 564 */ 565 static inline ssize_t 566 xdr_stream_decode_uint32_array(struct xdr_stream *xdr, 567 __u32 *array, size_t array_size) 568 { 569 __be32 *p; 570 __u32 len; 571 ssize_t retval; 572 573 if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0)) 574 return -EBADMSG; 575 p = xdr_inline_decode(xdr, len * sizeof(*p)); 576 if (unlikely(!p)) 577 return -EBADMSG; 578 if (array == NULL) 579 return len; 580 if (len <= array_size) { 581 if (len < array_size) 582 memset(array+len, 0, (array_size-len)*sizeof(*array)); 583 array_size = len; 584 retval = len; 585 } else 586 retval = -EMSGSIZE; 587 for (; array_size > 0; p++, array++, array_size--) 588 *array = be32_to_cpup(p); 589 return retval; 590 } 591 592 #endif /* _SUNRPC_XDR_H_ */ 593