The Tcpdump Group git mirrors - tcpdump/blob - extract.h

   1 /*
   2  * Copyright (c) 1992, 1993, 1994, 1995, 1996
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that: (1) source code distributions
   7  * retain the above copyright notice and this paragraph in its entirety, (2)
   8  * distributions including binary code include the above copyright notice and
   9  * this paragraph in its entirety in the documentation or other materials
  10  * provided with the distribution, and (3) all advertising materials mentioning
  11  * features or use of this software display the following acknowledgement:
  12  * ``This product includes software developed by the University of California,
  13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
  14  * the University nor the names of its contributors may be used to endorse
  15  * or promote products derived from this software without specific prior
  16  * written permission.
  17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  20  */
  21
  22 #include <string.h>
  23
  24 /*
  25  * For 8-bit values; needed to fetch a one-byte value.  Byte order
  26  * isn't relevant, and alignment isn't an issue.
  27  */
  28 #define EXTRACT_U_1(p)  ((uint8_t)(*(p)))
  29 #define EXTRACT_S_1(p)  ((int8_t)(*(p)))
  30
  31 /*
  32  * Inline functions or macros to extract possibly-unaligned big-endian
  33  * integral values.
  34  */
  35 #include "funcattrs.h"
  36
  37 /*
  38  * If we have versions of GCC or Clang that support an __attribute__
  39  * to say "if we're building with unsigned behavior sanitization,
  40  * don't complain about undefined behavior in this function", we
  41  * label these functions with that attribute - we *know* it's undefined
  42  * in the C standard, but we *also* know it does what we want with
  43  * the ISA we're targeting and the compiler we're using.
  44  *
  45  * For GCC 4.9.0 and later, we use __attribute__((no_sanitize_undefined));
  46  * pre-5.0 GCC doesn't have __has_attribute, and I'm not sure whether
  47  * GCC or Clang first had __attribute__((no_sanitize(XXX)).
  48  *
  49  * For Clang, we check for __attribute__((no_sanitize(XXX)) with
  50  * __has_attribute, as there are versions of Clang that support
  51  * __attribute__((no_sanitize("undefined")) but don't support
  52  * __attribute__((no_sanitize_undefined)).
  53  *
  54  * We define this here, rather than in funcattrs.h, because we
  55  * only want it used here, we don't want it to be broadly used.
  56  * (Any printer will get this defined, but this should at least
  57  * make it harder for people to find.)
  58  */
  59 #if defined(__GNUC__) && ((__GNUC__ * 100 + __GNUC_MINOR__) >= 409)
  60 #define UNALIGNED_OK    __attribute__((no_sanitize_undefined))
  61 #elif __has_attribute(no_sanitize)
  62 #define UNALIGNED_OK    __attribute__((no_sanitize("undefined")))
  63 #else
  64 #define UNALIGNED_OK
  65 #endif
  66
  67 #if (defined(__i386__) || defined(_M_IX86) || defined(__X86__) || defined(__x86_64__) || defined(_M_X64)) || \
  68     (defined(__arm__) || defined(_M_ARM) || defined(__aarch64__)) || \
  69     (defined(__m68k__) && (!defined(__mc68000__) && !defined(__mc68010__))) || \
  70     (defined(__ppc__) || defined(__ppc64__) || defined(_M_PPC) || defined(_ARCH_PPC) || defined(_ARCH_PPC64)) || \
  71     (defined(__s390__) || defined(__s390x__) || defined(__zarch__))
  72 /*
  73  * The processor natively handles unaligned loads, so we can just
  74  * cast the pointer and fetch through it.
  75  *
  76  * XXX - are those all the x86 tests we need?
  77  * XXX - do we need to worry about ARMv1 through ARMv5, which didn't
  78  * support unaligned loads, and, if so, do we need to worry about all
  79  * of them, or just some of them, e.g. ARMv5?
  80  * XXX - are those the only 68k tests we need not to generated
  81  * unaligned accesses if the target is the 68000 or 68010?
  82  * XXX - are there any tests we don't need, because some definitions are for
  83  * compilers that also predefine the GCC symbols?
  84  * XXX - do we need to test for both 32-bit and 64-bit versions of those
  85  * architectures in all cases?
  86  */
  87 UNALIGNED_OK static inline uint16_t
  88 EXTRACT_BE_U_2(const void *p)
  89 {
  90         return ((uint16_t)ntohs(*(const uint16_t *)(p)));
  91 }
  92
  93 UNALIGNED_OK static inline int16_t
  94 EXTRACT_BE_S_2(const void *p)
  95 {
  96         return ((int16_t)ntohs(*(const int16_t *)(p)));
  97 }
  98
  99 UNALIGNED_OK static inline uint32_t
 100 EXTRACT_BE_U_4(const void *p)
 101 {
 102         return ((uint32_t)ntohl(*(const uint32_t *)(p)));
 103 }
 104
 105 UNALIGNED_OK static inline int32_t
 106 EXTRACT_BE_S_4(const void *p)
 107 {
 108         return ((int32_t)ntohl(*(const int32_t *)(p)));
 109 }
 110
 111 UNALIGNED_OK static inline uint64_t
 112 EXTRACT_BE_U_8(const void *p)
 113 {
 114         return ((uint64_t)(((uint64_t)ntohl(*((const uint32_t *)(p) + 0))) << 32 |
 115                 ((uint64_t)ntohl(*((const uint32_t *)(p) + 1))) << 0));
 116
 117 }
 118
 119 UNALIGNED_OK static inline int64_t
 120 EXTRACT_BE_S_8(const void *p)
 121 {
 122         return ((int64_t)(((int64_t)ntohl(*((const uint32_t *)(p) + 0))) << 32 |
 123                 ((uint64_t)ntohl(*((const uint32_t *)(p) + 1))) << 0));
 124
 125 }
 126
 127 /*
 128  * Extract an IPv4 address, which is in network byte order, and not
 129  * necessarily aligned, and provide the result in host byte order.
 130  */
 131 UNALIGNED_OK static inline uint32_t
 132 EXTRACT_IPV4_TO_HOST_ORDER(const void *p)
 133 {
 134         return ((uint32_t)ntohl(*(const uint32_t *)(p)));
 135 }
 136 #elif ND_IS_AT_LEAST_GNUC_VERSION(2,0) && \
 137     (defined(__alpha) || defined(__alpha__) || \
 138      defined(__mips) || defined(__mips__))
 139 /*
 140  * This is MIPS or Alpha, which don't natively handle unaligned loads,
 141  * but which have instructions that can help when doing unaligned
 142  * loads, and this is GCC 2.0 or later or a compiler that claims to
 143  * be GCC 2.0 or later, which we assume that mean we have
 144  * __attribute__((packed)), which we can use to convince the compiler
 145  * to generate those instructions.
 146  *
 147  * Declare packed structures containing a uint16_t and a uint32_t,
 148  * cast the pointer to point to one of those, and fetch through it;
 149  * the GCC manual doesn't appear to explicitly say that
 150  * __attribute__((packed)) causes the compiler to generate unaligned-safe
 151  * code, but it apppears to do so.
 152  *
 153  * We do this in case the compiler can generate code using those
 154  * instructions to do an unaligned load and pass stuff to "ntohs()" or
 155  * "ntohl()", which might be better than than the code to fetch the
 156  * bytes one at a time and assemble them.  (That might not be the
 157  * case on a little-endian platform, such as DEC's MIPS machines and
 158  * Alpha machines, where "ntohs()" and "ntohl()" might not be done
 159  * inline.)
 160  *
 161  * We do this only for specific architectures because, for example,
 162  * at least some versions of GCC, when compiling for 64-bit SPARC,
 163  * generate code that assumes alignment if we do this.
 164  *
 165  * XXX - add other architectures and compilers as possible and
 166  * appropriate.
 167  *
 168  * HP's C compiler, indicated by __HP_cc being defined, supports
 169  * "#pragma unaligned N" in version A.05.50 and later, where "N"
 170  * specifies a number of bytes at which the typedef on the next
 171  * line is aligned, e.g.
 172  *
 173  *      #pragma unalign 1
 174  *      typedef uint16_t unaligned_uint16_t;
 175  *
 176  * to define unaligned_uint16_t as a 16-bit unaligned data type.
 177  * This could be presumably used, in sufficiently recent versions of
 178  * the compiler, with macros similar to those below.  This would be
 179  * useful only if that compiler could generate better code for PA-RISC
 180  * or Itanium than would be generated by a bunch of shifts-and-ORs.
 181  *
 182  * DEC C, indicated by __DECC being defined, has, at least on Alpha,
 183  * an __unaligned qualifier that can be applied to pointers to get the
 184  * compiler to generate code that does unaligned loads and stores when
 185  * dereferencing the pointer in question.
 186  *
 187  * XXX - what if the native C compiler doesn't support
 188  * __attribute__((packed))?  How can we get it to generate unaligned
 189  * accesses for *specific* items?
 190  */
 191 typedef struct {
 192         uint16_t        val;
 193 } __attribute__((packed)) unaligned_uint16_t;
 194
 195 typedef struct {
 196         int16_t         val;
 197 } __attribute__((packed)) unaligned_int16_t;
 198
 199 typedef struct {
 200         uint32_t        val;
 201 } __attribute__((packed)) unaligned_uint32_t;
 202
 203 typedef struct {
 204         int32_t         val;
 205 } __attribute__((packed)) unaligned_int32_t;
 206
 207 UNALIGNED_OK static inline uint16_t
 208 EXTRACT_BE_U_2(const void *p)
 209 {
 210         return ((uint16_t)ntohs(((const unaligned_uint16_t *)(p))->val));
 211 }
 212
 213 UNALIGNED_OK static inline int16_t
 214 EXTRACT_BE_S_2(const void *p)
 215 {
 216         return ((int16_t)ntohs(((const unaligned_int16_t *)(p))->val));
 217 }
 218
 219 UNALIGNED_OK static inline uint32_t
 220 EXTRACT_BE_U_4(const void *p)
 221 {
 222         return ((uint32_t)ntohl(((const unaligned_uint32_t *)(p))->val));
 223 }
 224
 225 UNALIGNED_OK static inline int32_t
 226 EXTRACT_BE_S_4(const void *p)
 227 {
 228         return ((int32_t)ntohl(((const unaligned_int32_t *)(p))->val));
 229 }
 230
 231 UNALIGNED_OK static inline uint64_t
 232 EXTRACT_BE_U_8(const void *p)
 233 {
 234         return ((uint64_t)(((uint64_t)ntohl(((const unaligned_uint32_t *)(p) + 0)->val)) << 32 |
 235                 ((uint64_t)ntohl(((const unaligned_uint32_t *)(p) + 1)->val)) << 0));
 236 }
 237
 238 UNALIGNED_OK static inline int64_t
 239 EXTRACT_BE_S_8(const void *p)
 240 {
 241         return ((int64_t)(((uint64_t)ntohl(((const unaligned_uint32_t *)(p) + 0)->val)) << 32 |
 242                 ((uint64_t)ntohl(((const unaligned_uint32_t *)(p) + 1)->val)) << 0));
 243 }
 244
 245 /*
 246  * Extract an IPv4 address, which is in network byte order, and not
 247  * necessarily aligned, and provide the result in host byte order.
 248  */
 249 UNALIGNED_OK static inline uint32_t
 250 EXTRACT_IPV4_TO_HOST_ORDER(const void *p)
 251 {
 252         return ((uint32_t)ntohl(((const unaligned_uint32_t *)(p))->val));
 253 }
 254 #else
 255 /*
 256  * This architecture doesn't natively support unaligned loads, and either
 257  * this isn't a GCC-compatible compiler, we don't have __attribute__,
 258  * or we do but we don't know of any better way with this instruction
 259  * set to do unaligned loads, so do unaligned loads of big-endian
 260  * quantities the hard way - fetch the bytes one at a time and
 261  * assemble them.
 262  */
 263 #define EXTRACT_BE_U_2(p) \
 264         ((uint16_t)(((uint16_t)(*((const uint8_t *)(p) + 0)) << 8) | \
 265                     ((uint16_t)(*((const uint8_t *)(p) + 1)) << 0)))
 266 #define EXTRACT_BE_S_2(p) \
 267         ((int16_t)(((uint16_t)(*((const uint8_t *)(p) + 0)) << 8) | \
 268                    ((uint16_t)(*((const uint8_t *)(p) + 1)) << 0)))
 269 #define EXTRACT_BE_U_4(p) \
 270         ((uint32_t)(((uint32_t)(*((const uint8_t *)(p) + 0)) << 24) | \
 271                     ((uint32_t)(*((const uint8_t *)(p) + 1)) << 16) | \
 272                     ((uint32_t)(*((const uint8_t *)(p) + 2)) << 8) | \
 273                     ((uint32_t)(*((const uint8_t *)(p) + 3)) << 0)))
 274 #define EXTRACT_BE_S_4(p) \
 275         ((int32_t)(((uint32_t)(*((const uint8_t *)(p) + 0)) << 24) | \
 276                    ((uint32_t)(*((const uint8_t *)(p) + 1)) << 16) | \
 277                    ((uint32_t)(*((const uint8_t *)(p) + 2)) << 8) | \
 278                    ((uint32_t)(*((const uint8_t *)(p) + 3)) << 0)))
 279 #define EXTRACT_BE_U_8(p) \
 280         ((uint64_t)(((uint64_t)(*((const uint8_t *)(p) + 0)) << 56) | \
 281                     ((uint64_t)(*((const uint8_t *)(p) + 1)) << 48) | \
 282                     ((uint64_t)(*((const uint8_t *)(p) + 2)) << 40) | \
 283                     ((uint64_t)(*((const uint8_t *)(p) + 3)) << 32) | \
 284                     ((uint64_t)(*((const uint8_t *)(p) + 4)) << 24) | \
 285                     ((uint64_t)(*((const uint8_t *)(p) + 5)) << 16) | \
 286                     ((uint64_t)(*((const uint8_t *)(p) + 6)) << 8) | \
 287                     ((uint64_t)(*((const uint8_t *)(p) + 7)) << 0)))
 288 #define EXTRACT_BE_S_8(p) \
 289         ((int64_t)(((uint64_t)(*((const uint8_t *)(p) + 0)) << 56) | \
 290                    ((uint64_t)(*((const uint8_t *)(p) + 1)) << 48) | \
 291                    ((uint64_t)(*((const uint8_t *)(p) + 2)) << 40) | \
 292                    ((uint64_t)(*((const uint8_t *)(p) + 3)) << 32) | \
 293                    ((uint64_t)(*((const uint8_t *)(p) + 4)) << 24) | \
 294                    ((uint64_t)(*((const uint8_t *)(p) + 5)) << 16) | \
 295                    ((uint64_t)(*((const uint8_t *)(p) + 6)) << 8) | \
 296                    ((uint64_t)(*((const uint8_t *)(p) + 7)) << 0)))
 297
 298 /*
 299  * Extract an IPv4 address, which is in network byte order, and not
 300  * necessarily aligned, and provide the result in host byte order.
 301  */
 302 #define EXTRACT_IPV4_TO_HOST_ORDER(p) \
 303         ((uint32_t)(((uint32_t)(*((const uint8_t *)(p) + 0)) << 24) | \
 304                     ((uint32_t)(*((const uint8_t *)(p) + 1)) << 16) | \
 305                     ((uint32_t)(*((const uint8_t *)(p) + 2)) << 8) | \
 306                     ((uint32_t)(*((const uint8_t *)(p) + 3)) << 0)))
 307 #endif /* unaligned access checks */
 308
 309 /*
 310  * Extract numerical values in *host* byte order.  (Some metadata
 311  * headers are in the byte order of the host that wrote the file,
 312  * and libpcap translate them to the byte order of the host
 313  * reading the file.  This means that if a program on that host
 314  * reads with libpcap and writes to a new file, the new file will
 315  * be written in the byte order of the host writing the file.  Thus,
 316  * the magic number in pcap files and byte-order magic in pcapng
 317  * files can be used to determine the byte order in those metadata
 318  * headers.)
 319  *
 320  * XXX - on platforms that can do unaligned accesses, just cast and
 321  * dereference the pointer.
 322  */
 323 static inline uint16_t
 324 EXTRACT_HE_U_2(const void *p)
 325 {
 326         uint16_t val;
 327
 328         UNALIGNED_MEMCPY(&val, p, sizeof(uint16_t));
 329         return val;
 330 }
 331
 332 static inline int16_t
 333 EXTRACT_HE_S_2(const void *p)
 334 {
 335         int16_t val;
 336
 337         UNALIGNED_MEMCPY(&val, p, sizeof(int16_t));
 338         return val;
 339 }
 340
 341 static inline uint32_t
 342 EXTRACT_HE_U_4(const void *p)
 343 {
 344         uint32_t val;
 345
 346         UNALIGNED_MEMCPY(&val, p, sizeof(uint32_t));
 347         return val;
 348 }
 349
 350 static inline int32_t
 351 EXTRACT_HE_S_4(const void *p)
 352 {
 353         int32_t val;
 354
 355         UNALIGNED_MEMCPY(&val, p, sizeof(int32_t));
 356         return val;
 357 }
 358
 359 /*
 360  * Extract an IPv4 address, which is in network byte order, and which
 361  * is not necessarily aligned on a 4-byte boundary, and provide the
 362  * result in network byte order.
 363  *
 364  * This works the same way regardless of the host's byte order.
 365  */
 366 static inline uint32_t
 367 EXTRACT_IPV4_TO_NETWORK_ORDER(const void *p)
 368 {
 369         uint32_t addr;
 370
 371         UNALIGNED_MEMCPY(&addr, p, sizeof(uint32_t));
 372         return addr;
 373 }
 374
 375 /*
 376  * Non-power-of-2 sizes.
 377  */
 378 #define EXTRACT_BE_U_3(p) \
 379         ((uint32_t)(((uint32_t)(*((const uint8_t *)(p) + 0)) << 16) | \
 380                     ((uint32_t)(*((const uint8_t *)(p) + 1)) << 8) | \
 381                     ((uint32_t)(*((const uint8_t *)(p) + 2)) << 0)))
 382
 383 #define EXTRACT_BE_S_3(p) \
 384         (((*((const uint8_t *)(p) + 0)) & 0x80) ? \
 385           ((int32_t)(((uint32_t)(*((const uint8_t *)(p) + 0)) << 16) | \
 386                      ((uint32_t)(*((const uint8_t *)(p) + 1)) << 8) | \
 387                      ((uint32_t)(*((const uint8_t *)(p) + 2)) << 0))) : \
 388           ((int32_t)(0xFF000000U | \
 389                      ((uint32_t)(*((const uint8_t *)(p) + 0)) << 16) | \
 390                      ((uint32_t)(*((const uint8_t *)(p) + 1)) << 8) | \
 391                      ((uint32_t)(*((const uint8_t *)(p) + 2)) << 0))))
 392
 393 #define EXTRACT_BE_U_5(p) \
 394         ((uint64_t)(((uint64_t)(*((const uint8_t *)(p) + 0)) << 32) | \
 395                     ((uint64_t)(*((const uint8_t *)(p) + 1)) << 24) | \
 396                     ((uint64_t)(*((const uint8_t *)(p) + 2)) << 16) | \
 397                     ((uint64_t)(*((const uint8_t *)(p) + 3)) << 8) | \
 398                     ((uint64_t)(*((const uint8_t *)(p) + 4)) << 0)))
 399
 400 #define EXTRACT_BE_S_5(p) \
 401         (((*((const uint8_t *)(p) + 0)) & 0x80) ? \
 402           ((int64_t)(((uint64_t)(*((const uint8_t *)(p) + 0)) << 32) | \
 403                      ((uint64_t)(*((const uint8_t *)(p) + 1)) << 24) | \
 404                      ((uint64_t)(*((const uint8_t *)(p) + 2)) << 16) | \
 405                      ((uint64_t)(*((const uint8_t *)(p) + 3)) << 8) | \
 406                      ((uint64_t)(*((const uint8_t *)(p) + 4)) << 0))) : \
 407           ((int64_t)(INT64_T_CONSTANT(0xFFFFFF0000000000U) | \
 408                      ((uint64_t)(*((const uint8_t *)(p) + 0)) << 32) | \
 409                      ((uint64_t)(*((const uint8_t *)(p) + 1)) << 24) | \
 410                      ((uint64_t)(*((const uint8_t *)(p) + 2)) << 16) | \
 411                      ((uint64_t)(*((const uint8_t *)(p) + 3)) << 8) | \
 412                      ((uint64_t)(*((const uint8_t *)(p) + 4)) << 0))))
 413
 414 #define EXTRACT_BE_U_6(p) \
 415         ((uint64_t)(((uint64_t)(*((const uint8_t *)(p) + 0)) << 40) | \
 416                     ((uint64_t)(*((const uint8_t *)(p) + 1)) << 32) | \
 417                     ((uint64_t)(*((const uint8_t *)(p) + 2)) << 24) | \
 418                     ((uint64_t)(*((const uint8_t *)(p) + 3)) << 16) | \
 419                     ((uint64_t)(*((const uint8_t *)(p) + 4)) << 8) | \
 420                     ((uint64_t)(*((const uint8_t *)(p) + 5)) << 0)))
 421
 422 #define EXTRACT_BE_S_6(p) \
 423         (((*((const uint8_t *)(p) + 0)) & 0x80) ? \
 424           ((uint64_t)(((uint64_t)(*((const uint8_t *)(p) + 0)) << 40) | \
 425                       ((uint64_t)(*((const uint8_t *)(p) + 1)) << 32) | \
 426                       ((uint64_t)(*((const uint8_t *)(p) + 2)) << 24) | \
 427                       ((uint64_t)(*((const uint8_t *)(p) + 3)) << 16) | \
 428                       ((uint64_t)(*((const uint8_t *)(p) + 4)) << 8) | \
 429                       ((uint64_t)(*((const uint8_t *)(p) + 5)) << 0))) : \
 430           ((int64_t)(INT64_T_CONSTANT(0xFFFFFFFF00000000U) | \
 431                       ((uint64_t)(*((const uint8_t *)(p) + 0)) << 40) | \
 432                       ((uint64_t)(*((const uint8_t *)(p) + 1)) << 32) | \
 433                       ((uint64_t)(*((const uint8_t *)(p) + 2)) << 24) | \
 434                       ((uint64_t)(*((const uint8_t *)(p) + 3)) << 16) | \
 435                       ((uint64_t)(*((const uint8_t *)(p) + 4)) << 8) | \
 436                       ((uint64_t)(*((const uint8_t *)(p) + 5)) << 0))))
 437
 438 #define EXTRACT_BE_U_7(p) \
 439         ((uint64_t)(((uint64_t)(*((const uint8_t *)(p) + 0)) << 48) | \
 440                     ((uint64_t)(*((const uint8_t *)(p) + 1)) << 40) | \
 441                     ((uint64_t)(*((const uint8_t *)(p) + 2)) << 32) | \
 442                     ((uint64_t)(*((const uint8_t *)(p) + 3)) << 24) | \
 443                     ((uint64_t)(*((const uint8_t *)(p) + 4)) << 16) | \
 444                     ((uint64_t)(*((const uint8_t *)(p) + 5)) << 8) | \
 445                     ((uint64_t)(*((const uint8_t *)(p) + 6)) << 0)))
 446
 447 #define EXTRACT_BE_S_7(p) \
 448         (((*((const uint8_t *)(p) + 0)) & 0x80) ? \
 449           ((int64_t)(((uint64_t)(*((const uint8_t *)(p) + 0)) << 48) | \
 450                      ((uint64_t)(*((const uint8_t *)(p) + 1)) << 40) | \
 451                      ((uint64_t)(*((const uint8_t *)(p) + 2)) << 32) | \
 452                      ((uint64_t)(*((const uint8_t *)(p) + 3)) << 24) | \
 453                      ((uint64_t)(*((const uint8_t *)(p) + 4)) << 16) | \
 454                      ((uint64_t)(*((const uint8_t *)(p) + 5)) << 8) | \
 455                      ((uint64_t)(*((const uint8_t *)(p) + 6)) << 0))) : \
 456             ((int64_t)(INT64_T_CONSTANT(0xFFFFFFFFFF000000U) | \
 457                      ((uint64_t)(*((const uint8_t *)(p) + 0)) << 48) | \
 458                      ((uint64_t)(*((const uint8_t *)(p) + 1)) << 40) | \
 459                      ((uint64_t)(*((const uint8_t *)(p) + 2)) << 32) | \
 460                      ((uint64_t)(*((const uint8_t *)(p) + 3)) << 24) | \
 461                      ((uint64_t)(*((const uint8_t *)(p) + 4)) << 16) | \
 462                      ((uint64_t)(*((const uint8_t *)(p) + 5)) << 8) | \
 463                      ((uint64_t)(*((const uint8_t *)(p) + 6)) << 0))))
 464
 465 /*
 466  * Macros to extract possibly-unaligned little-endian integral values.
 467  * XXX - do loads on little-endian machines that support unaligned loads?
 468  */
 469 #define EXTRACT_LE_U_2(p) \
 470         ((uint16_t)(((uint16_t)(*((const uint8_t *)(p) + 1)) << 8) | \
 471                     ((uint16_t)(*((const uint8_t *)(p) + 0)) << 0)))
 472 #define EXTRACT_LE_S_2(p) \
 473         ((int16_t)(((uint16_t)(*((const uint8_t *)(p) + 1)) << 8) | \
 474                    ((uint16_t)(*((const uint8_t *)(p) + 0)) << 0)))
 475 #define EXTRACT_LE_U_4(p) \
 476         ((uint32_t)(((uint32_t)(*((const uint8_t *)(p) + 3)) << 24) | \
 477                     ((uint32_t)(*((const uint8_t *)(p) + 2)) << 16) | \
 478                     ((uint32_t)(*((const uint8_t *)(p) + 1)) << 8) | \
 479                     ((uint32_t)(*((const uint8_t *)(p) + 0)) << 0)))
 480 #define EXTRACT_LE_S_4(p) \
 481         ((int32_t)(((uint32_t)(*((const uint8_t *)(p) + 3)) << 24) | \
 482                    ((uint32_t)(*((const uint8_t *)(p) + 2)) << 16) | \
 483                    ((uint32_t)(*((const uint8_t *)(p) + 1)) << 8) | \
 484                    ((uint32_t)(*((const uint8_t *)(p) + 0)) << 0)))
 485 #define EXTRACT_LE_U_3(p) \
 486         ((uint32_t)(((uint32_t)(*((const uint8_t *)(p) + 2)) << 16) | \
 487                     ((uint32_t)(*((const uint8_t *)(p) + 1)) << 8) | \
 488                     ((uint32_t)(*((const uint8_t *)(p) + 0)) << 0)))
 489 #define EXTRACT_LE_S_3(p) \
 490         ((int32_t)(((uint32_t)(*((const uint8_t *)(p) + 2)) << 16) | \
 491                    ((uint32_t)(*((const uint8_t *)(p) + 1)) << 8) | \
 492                    ((uint32_t)(*((const uint8_t *)(p) + 0)) << 0)))
 493 #define EXTRACT_LE_U_8(p) \
 494         ((uint64_t)(((uint64_t)(*((const uint8_t *)(p) + 7)) << 56) | \
 495                     ((uint64_t)(*((const uint8_t *)(p) + 6)) << 48) | \
 496                     ((uint64_t)(*((const uint8_t *)(p) + 5)) << 40) | \
 497                     ((uint64_t)(*((const uint8_t *)(p) + 4)) << 32) | \
 498                     ((uint64_t)(*((const uint8_t *)(p) + 3)) << 24) | \
 499                     ((uint64_t)(*((const uint8_t *)(p) + 2)) << 16) | \
 500                     ((uint64_t)(*((const uint8_t *)(p) + 1)) << 8) | \
 501                     ((uint64_t)(*((const uint8_t *)(p) + 0)) << 0)))
 502 #define EXTRACT_LE_S_8(p) \
 503         ((int64_t)(((uint64_t)(*((const uint8_t *)(p) + 7)) << 56) | \
 504                    ((uint64_t)(*((const uint8_t *)(p) + 6)) << 48) | \
 505                    ((uint64_t)(*((const uint8_t *)(p) + 5)) << 40) | \
 506                    ((uint64_t)(*((const uint8_t *)(p) + 4)) << 32) | \
 507                    ((uint64_t)(*((const uint8_t *)(p) + 3)) << 24) | \
 508                    ((uint64_t)(*((const uint8_t *)(p) + 2)) << 16) | \
 509                    ((uint64_t)(*((const uint8_t *)(p) + 1)) << 8) | \
 510                    ((uint64_t)(*((const uint8_t *)(p) + 0)) << 0)))
 511
 512 /*
 513  * Macros to check the presence of the values in question.
 514  */
 515 #define ND_TTEST_1(p) ND_TTEST_LEN((p), 1)
 516 #define ND_TCHECK_1(p) ND_TCHECK_LEN((p), 1)
 517
 518 #define ND_TTEST_2(p) ND_TTEST_LEN((p), 2)
 519 #define ND_TCHECK_2(p) ND_TCHECK_LEN((p), 2)
 520
 521 #define ND_TTEST_3(p) ND_TTEST_LEN((p), 3)
 522 #define ND_TCHECK_3(p) ND_TCHECK_LEN((p), 3)
 523
 524 #define ND_TTEST_4(p) ND_TTEST_LEN((p), 4)
 525 #define ND_TCHECK_4(p) ND_TCHECK_LEN((p), 4)
 526
 527 #define ND_TTEST_5(p) ND_TTEST_LEN((p), 5)
 528 #define ND_TCHECK_5(p) ND_TCHECK_LEN((p), 5)
 529
 530 #define ND_TTEST_6(p) ND_TTEST_LEN((p), 6)
 531 #define ND_TCHECK_6(p) ND_TCHECK_LEN((p), 6)
 532
 533 #define ND_TTEST_7(p) ND_TTEST_LEN((p), 7)
 534 #define ND_TCHECK_7(p) ND_TCHECK_LEN((p), 7)
 535
 536 #define ND_TTEST_8(p) ND_TTEST_LEN((p), 8)
 537 #define ND_TCHECK_8(p) ND_TCHECK_LEN((p), 8)
 538
 539 #define ND_TTEST_16(p) ND_TTEST_LEN((p), 16)
 540 #define ND_TCHECK_16(p) ND_TCHECK_LEN((p), 16)