1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * XDR standard data types and function declarations 4 * 5 * Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de> 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_auth_null cpu_to_be32(RPC_AUTH_NULL) 91 #define rpc_auth_unix cpu_to_be32(RPC_AUTH_UNIX) 92 #define rpc_auth_short cpu_to_be32(RPC_AUTH_SHORT) 93 #define rpc_auth_gss cpu_to_be32(RPC_AUTH_GSS) 94 95 #define rpc_call cpu_to_be32(RPC_CALL) 96 #define rpc_reply cpu_to_be32(RPC_REPLY) 97 98 #define rpc_msg_accepted cpu_to_be32(RPC_MSG_ACCEPTED) 99 100 #define rpc_success cpu_to_be32(RPC_SUCCESS) 101 #define rpc_prog_unavail cpu_to_be32(RPC_PROG_UNAVAIL) 102 #define rpc_prog_mismatch cpu_to_be32(RPC_PROG_MISMATCH) 103 #define rpc_proc_unavail cpu_to_be32(RPC_PROC_UNAVAIL) 104 #define rpc_garbage_args cpu_to_be32(RPC_GARBAGE_ARGS) 105 #define rpc_system_err cpu_to_be32(RPC_SYSTEM_ERR) 106 #define rpc_drop_reply cpu_to_be32(RPC_DROP_REPLY) 107 108 #define rpc_mismatch cpu_to_be32(RPC_MISMATCH) 109 #define rpc_auth_error cpu_to_be32(RPC_AUTH_ERROR) 110 111 #define rpc_auth_ok cpu_to_be32(RPC_AUTH_OK) 112 #define rpc_autherr_badcred cpu_to_be32(RPC_AUTH_BADCRED) 113 #define rpc_autherr_rejectedcred cpu_to_be32(RPC_AUTH_REJECTEDCRED) 114 #define rpc_autherr_badverf cpu_to_be32(RPC_AUTH_BADVERF) 115 #define rpc_autherr_rejectedverf cpu_to_be32(RPC_AUTH_REJECTEDVERF) 116 #define rpc_autherr_tooweak cpu_to_be32(RPC_AUTH_TOOWEAK) 117 #define rpcsec_gsserr_credproblem cpu_to_be32(RPCSEC_GSS_CREDPROBLEM) 118 #define rpcsec_gsserr_ctxproblem cpu_to_be32(RPCSEC_GSS_CTXPROBLEM) 119 120 /* 121 * Miscellaneous XDR helper functions 122 */ 123 __be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int len); 124 __be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int len); 125 __be32 *xdr_encode_string(__be32 *p, const char *s); 126 __be32 *xdr_decode_string_inplace(__be32 *p, char **sp, unsigned int *lenp, 127 unsigned int maxlen); 128 __be32 *xdr_encode_netobj(__be32 *p, const struct xdr_netobj *); 129 __be32 *xdr_decode_netobj(__be32 *p, struct xdr_netobj *); 130 131 void xdr_inline_pages(struct xdr_buf *, unsigned int, 132 struct page **, unsigned int, unsigned int); 133 void xdr_terminate_string(struct xdr_buf *, const u32); 134 size_t xdr_buf_pagecount(struct xdr_buf *buf); 135 int xdr_alloc_bvec(struct xdr_buf *buf, gfp_t gfp); 136 void xdr_free_bvec(struct xdr_buf *buf); 137 138 static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len) 139 { 140 return xdr_encode_opaque(p, s, len); 141 } 142 143 /* 144 * Decode 64bit quantities (NFSv3 support) 145 */ 146 static inline __be32 * 147 xdr_encode_hyper(__be32 *p, __u64 val) 148 { 149 put_unaligned_be64(val, p); 150 return p + 2; 151 } 152 153 static inline __be32 * 154 xdr_decode_hyper(__be32 *p, __u64 *valp) 155 { 156 *valp = get_unaligned_be64(p); 157 return p + 2; 158 } 159 160 static inline __be32 * 161 xdr_decode_opaque_fixed(__be32 *p, void *ptr, unsigned int len) 162 { 163 memcpy(ptr, p, len); 164 return p + XDR_QUADLEN(len); 165 } 166 167 /* 168 * Adjust kvec to reflect end of xdr'ed data (RPC client XDR) 169 */ 170 static inline int 171 xdr_adjust_iovec(struct kvec *iov, __be32 *p) 172 { 173 return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base); 174 } 175 176 /* 177 * XDR buffer helper functions 178 */ 179 extern void xdr_shift_buf(struct xdr_buf *, size_t); 180 extern void xdr_buf_from_iov(struct kvec *, struct xdr_buf *); 181 extern int xdr_buf_subsegment(struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int); 182 extern int xdr_buf_read_netobj(struct xdr_buf *, struct xdr_netobj *, unsigned int); 183 extern int read_bytes_from_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int); 184 extern int write_bytes_to_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int); 185 186 /* 187 * Helper structure for copying from an sk_buff. 188 */ 189 struct xdr_skb_reader { 190 struct sk_buff *skb; 191 unsigned int offset; 192 size_t count; 193 __wsum csum; 194 }; 195 196 typedef size_t (*xdr_skb_read_actor)(struct xdr_skb_reader *desc, void *to, size_t len); 197 198 extern int csum_partial_copy_to_xdr(struct xdr_buf *, struct sk_buff *); 199 200 extern int xdr_encode_word(struct xdr_buf *, unsigned int, u32); 201 extern int xdr_decode_word(struct xdr_buf *, unsigned int, u32 *); 202 203 struct xdr_array2_desc; 204 typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem); 205 struct xdr_array2_desc { 206 unsigned int elem_size; 207 unsigned int array_len; 208 unsigned int array_maxlen; 209 xdr_xcode_elem_t xcode; 210 }; 211 212 extern int xdr_decode_array2(struct xdr_buf *buf, unsigned int base, 213 struct xdr_array2_desc *desc); 214 extern int xdr_encode_array2(struct xdr_buf *buf, unsigned int base, 215 struct xdr_array2_desc *desc); 216 extern void _copy_from_pages(char *p, struct page **pages, size_t pgbase, 217 size_t len); 218 219 /* 220 * Provide some simple tools for XDR buffer overflow-checking etc. 221 */ 222 struct xdr_stream { 223 __be32 *p; /* start of available buffer */ 224 struct xdr_buf *buf; /* XDR buffer to read/write */ 225 226 __be32 *end; /* end of available buffer space */ 227 struct kvec *iov; /* pointer to the current kvec */ 228 struct kvec scratch; /* Scratch buffer */ 229 struct page **page_ptr; /* pointer to the current page */ 230 unsigned int nwords; /* Remaining decode buffer length */ 231 232 struct rpc_rqst *rqst; /* For debugging */ 233 }; 234 235 /* 236 * These are the xdr_stream style generic XDR encode and decode functions. 237 */ 238 typedef void (*kxdreproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr, 239 const void *obj); 240 typedef int (*kxdrdproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr, 241 void *obj); 242 243 extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, 244 __be32 *p, struct rpc_rqst *rqst); 245 extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes); 246 extern void xdr_commit_encode(struct xdr_stream *xdr); 247 extern void xdr_truncate_encode(struct xdr_stream *xdr, size_t len); 248 extern int xdr_restrict_buflen(struct xdr_stream *xdr, int newbuflen); 249 extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages, 250 unsigned int base, unsigned int len); 251 extern unsigned int xdr_stream_pos(const struct xdr_stream *xdr); 252 extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, 253 __be32 *p, struct rpc_rqst *rqst); 254 extern void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf, 255 struct page **pages, unsigned int len); 256 extern void xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen); 257 extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes); 258 extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len); 259 extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len); 260 extern int xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data); 261 262 /** 263 * xdr_stream_remaining - Return the number of bytes remaining in the stream 264 * @xdr: pointer to struct xdr_stream 265 * 266 * Return value: 267 * Number of bytes remaining in @xdr before xdr->end 268 */ 269 static inline size_t 270 xdr_stream_remaining(const struct xdr_stream *xdr) 271 { 272 return xdr->nwords << 2; 273 } 274 275 ssize_t xdr_stream_decode_opaque(struct xdr_stream *xdr, void *ptr, 276 size_t size); 277 ssize_t xdr_stream_decode_opaque_dup(struct xdr_stream *xdr, void **ptr, 278 size_t maxlen, gfp_t gfp_flags); 279 ssize_t xdr_stream_decode_string(struct xdr_stream *xdr, char *str, 280 size_t size); 281 ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str, 282 size_t maxlen, gfp_t gfp_flags); 283 /** 284 * xdr_align_size - Calculate padded size of an object 285 * @n: Size of an object being XDR encoded (in bytes) 286 * 287 * Return value: 288 * Size (in bytes) of the object including xdr padding 289 */ 290 static inline size_t 291 xdr_align_size(size_t n) 292 { 293 const size_t mask = sizeof(__u32) - 1; 294 295 return (n + mask) & ~mask; 296 } 297 298 /** 299 * xdr_stream_encode_u32 - Encode a 32-bit integer 300 * @xdr: pointer to xdr_stream 301 * @n: integer to encode 302 * 303 * Return values: 304 * On success, returns length in bytes of XDR buffer consumed 305 * %-EMSGSIZE on XDR buffer overflow 306 */ 307 static inline ssize_t 308 xdr_stream_encode_u32(struct xdr_stream *xdr, __u32 n) 309 { 310 const size_t len = sizeof(n); 311 __be32 *p = xdr_reserve_space(xdr, len); 312 313 if (unlikely(!p)) 314 return -EMSGSIZE; 315 *p = cpu_to_be32(n); 316 return len; 317 } 318 319 /** 320 * xdr_stream_encode_u64 - Encode a 64-bit integer 321 * @xdr: pointer to xdr_stream 322 * @n: 64-bit integer to encode 323 * 324 * Return values: 325 * On success, returns length in bytes of XDR buffer consumed 326 * %-EMSGSIZE on XDR buffer overflow 327 */ 328 static inline ssize_t 329 xdr_stream_encode_u64(struct xdr_stream *xdr, __u64 n) 330 { 331 const size_t len = sizeof(n); 332 __be32 *p = xdr_reserve_space(xdr, len); 333 334 if (unlikely(!p)) 335 return -EMSGSIZE; 336 xdr_encode_hyper(p, n); 337 return len; 338 } 339 340 /** 341 * xdr_stream_encode_opaque_inline - Encode opaque xdr data 342 * @xdr: pointer to xdr_stream 343 * @ptr: pointer to void pointer 344 * @len: size of object 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_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t len) 352 { 353 size_t count = sizeof(__u32) + xdr_align_size(len); 354 __be32 *p = xdr_reserve_space(xdr, count); 355 356 if (unlikely(!p)) { 357 *ptr = NULL; 358 return -EMSGSIZE; 359 } 360 xdr_encode_opaque(p, NULL, len); 361 *ptr = ++p; 362 return count; 363 } 364 365 /** 366 * xdr_stream_encode_opaque_fixed - Encode fixed length opaque xdr data 367 * @xdr: pointer to xdr_stream 368 * @ptr: pointer to opaque data object 369 * @len: size of object pointed to by @ptr 370 * 371 * Return values: 372 * On success, returns length in bytes of XDR buffer consumed 373 * %-EMSGSIZE on XDR buffer overflow 374 */ 375 static inline ssize_t 376 xdr_stream_encode_opaque_fixed(struct xdr_stream *xdr, const void *ptr, size_t len) 377 { 378 __be32 *p = xdr_reserve_space(xdr, len); 379 380 if (unlikely(!p)) 381 return -EMSGSIZE; 382 xdr_encode_opaque_fixed(p, ptr, len); 383 return xdr_align_size(len); 384 } 385 386 /** 387 * xdr_stream_encode_opaque - Encode variable length opaque xdr data 388 * @xdr: pointer to xdr_stream 389 * @ptr: pointer to opaque data object 390 * @len: size of object pointed to by @ptr 391 * 392 * Return values: 393 * On success, returns length in bytes of XDR buffer consumed 394 * %-EMSGSIZE on XDR buffer overflow 395 */ 396 static inline ssize_t 397 xdr_stream_encode_opaque(struct xdr_stream *xdr, const void *ptr, size_t len) 398 { 399 size_t count = sizeof(__u32) + xdr_align_size(len); 400 __be32 *p = xdr_reserve_space(xdr, count); 401 402 if (unlikely(!p)) 403 return -EMSGSIZE; 404 xdr_encode_opaque(p, ptr, len); 405 return count; 406 } 407 408 /** 409 * xdr_stream_encode_uint32_array - Encode variable length array of integers 410 * @xdr: pointer to xdr_stream 411 * @array: array of integers 412 * @array_size: number of elements in @array 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_uint32_array(struct xdr_stream *xdr, 420 const __u32 *array, size_t array_size) 421 { 422 ssize_t ret = (array_size+1) * sizeof(__u32); 423 __be32 *p = xdr_reserve_space(xdr, ret); 424 425 if (unlikely(!p)) 426 return -EMSGSIZE; 427 *p++ = cpu_to_be32(array_size); 428 for (; array_size > 0; p++, array++, array_size--) 429 *p = cpu_to_be32p(array); 430 return ret; 431 } 432 433 /** 434 * xdr_stream_decode_u32 - Decode a 32-bit integer 435 * @xdr: pointer to xdr_stream 436 * @ptr: location to store integer 437 * 438 * Return values: 439 * %0 on success 440 * %-EBADMSG on XDR buffer overflow 441 */ 442 static inline ssize_t 443 xdr_stream_decode_u32(struct xdr_stream *xdr, __u32 *ptr) 444 { 445 const size_t count = sizeof(*ptr); 446 __be32 *p = xdr_inline_decode(xdr, count); 447 448 if (unlikely(!p)) 449 return -EBADMSG; 450 *ptr = be32_to_cpup(p); 451 return 0; 452 } 453 454 /** 455 * xdr_stream_decode_opaque_fixed - Decode fixed length opaque xdr data 456 * @xdr: pointer to xdr_stream 457 * @ptr: location to store data 458 * @len: size of buffer pointed to by @ptr 459 * 460 * Return values: 461 * On success, returns size of object stored in @ptr 462 * %-EBADMSG on XDR buffer overflow 463 */ 464 static inline ssize_t 465 xdr_stream_decode_opaque_fixed(struct xdr_stream *xdr, void *ptr, size_t len) 466 { 467 __be32 *p = xdr_inline_decode(xdr, len); 468 469 if (unlikely(!p)) 470 return -EBADMSG; 471 xdr_decode_opaque_fixed(p, ptr, len); 472 return len; 473 } 474 475 /** 476 * xdr_stream_decode_opaque_inline - Decode variable length opaque xdr data 477 * @xdr: pointer to xdr_stream 478 * @ptr: location to store pointer to opaque data 479 * @maxlen: maximum acceptable object size 480 * 481 * Note: the pointer stored in @ptr cannot be assumed valid after the XDR 482 * buffer has been destroyed, or even after calling xdr_inline_decode() 483 * on @xdr. It is therefore expected that the object it points to should 484 * be processed immediately. 485 * 486 * Return values: 487 * On success, returns size of object stored in *@ptr 488 * %-EBADMSG on XDR buffer overflow 489 * %-EMSGSIZE if the size of the object would exceed @maxlen 490 */ 491 static inline ssize_t 492 xdr_stream_decode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t maxlen) 493 { 494 __be32 *p; 495 __u32 len; 496 497 *ptr = NULL; 498 if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0)) 499 return -EBADMSG; 500 if (len != 0) { 501 p = xdr_inline_decode(xdr, len); 502 if (unlikely(!p)) 503 return -EBADMSG; 504 if (unlikely(len > maxlen)) 505 return -EMSGSIZE; 506 *ptr = p; 507 } 508 return len; 509 } 510 511 /** 512 * xdr_stream_decode_uint32_array - Decode variable length array of integers 513 * @xdr: pointer to xdr_stream 514 * @array: location to store the integer array or NULL 515 * @array_size: number of elements to store 516 * 517 * Return values: 518 * On success, returns number of elements stored in @array 519 * %-EBADMSG on XDR buffer overflow 520 * %-EMSGSIZE if the size of the array exceeds @array_size 521 */ 522 static inline ssize_t 523 xdr_stream_decode_uint32_array(struct xdr_stream *xdr, 524 __u32 *array, size_t array_size) 525 { 526 __be32 *p; 527 __u32 len; 528 ssize_t retval; 529 530 if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0)) 531 return -EBADMSG; 532 p = xdr_inline_decode(xdr, len * sizeof(*p)); 533 if (unlikely(!p)) 534 return -EBADMSG; 535 if (array == NULL) 536 return len; 537 if (len <= array_size) { 538 if (len < array_size) 539 memset(array+len, 0, (array_size-len)*sizeof(*array)); 540 array_size = len; 541 retval = len; 542 } else 543 retval = -EMSGSIZE; 544 for (; array_size > 0; p++, array++, array_size--) 545 *array = be32_to_cpup(p); 546 return retval; 547 } 548 #endif /* __KERNEL__ */ 549 550 #endif /* _SUNRPC_XDR_H_ */ 551