contrib/tcpdump/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 #ifndef EXTRACT_H
  23 #define EXTRACT_H
  24
  25 #include <string.h>
  26
  27 /*
  28  * For 8-bit values; needed to fetch a one-byte value.  Byte order
  29  * isn't relevant, and alignment isn't an issue.
  30  */
  31 #define EXTRACT_U_1(p)  ((uint8_t)(*(p)))
  32 #define EXTRACT_S_1(p)  ((int8_t)(*(p)))
  33
  34 /*
  35  * Inline functions or macros to extract possibly-unaligned big-endian
  36  * integral values.
  37  */
  38 #include "funcattrs.h"
  39 #include "netdissect.h"
  40
  41 /*
  42  * If we have versions of GCC or Clang that support an __attribute__
  43  * to say "if we're building with unsigned behavior sanitization,
  44  * don't complain about undefined behavior in this function", we
  45  * label these functions with that attribute - we *know* it's undefined
  46  * in the C standard, but we *also* know it does what we want with
  47  * the ISA we're targeting and the compiler we're using.
  48  *
  49  * For GCC 4.9.0 and later, we use __attribute__((no_sanitize_undefined));
  50  * pre-5.0 GCC doesn't have __has_attribute, and I'm not sure whether
  51  * GCC or Clang first had __attribute__((no_sanitize(XXX)).
  52  *
  53  * For Clang, we check for __attribute__((no_sanitize(XXX)) with
  54  * __has_attribute, as there are versions of Clang that support
  55  * __attribute__((no_sanitize("undefined")) but don't support
  56  * __attribute__((no_sanitize_undefined)).
  57  *
  58  * We define this here, rather than in funcattrs.h, because we
  59  * only want it used here, we don't want it to be broadly used.
  60  * (Any printer will get this defined, but this should at least
  61  * make it harder for people to find.)
  62  */
  63 #if defined(__GNUC__) && ((__GNUC__ * 100 + __GNUC_MINOR__) >= 409)
  64 #define UNALIGNED_OK    __attribute__((no_sanitize_undefined))
  65 #elif __has_attribute(no_sanitize)
  66 #define UNALIGNED_OK    __attribute__((no_sanitize("undefined")))
  67 #else
  68 #define UNALIGNED_OK
  69 #endif
  70
  71 #if (defined(__i386__) || defined(_M_IX86) || defined(__X86__) || defined(__x86_64__) || defined(_M_X64)) || \
  72     (defined(__m68k__) && (!defined(__mc68000__) && !defined(__mc68010__))) || \
  73     (defined(__ppc__) || defined(__ppc64__) || defined(_M_PPC) || defined(_ARCH_PPC) || defined(_ARCH_PPC64)) || \
  74     (defined(__s390__) || defined(__s390x__) || defined(__zarch__))
  75 /*
  76  * The processor natively handles unaligned loads, so we can just
  77  * cast the pointer and fetch through it.
  78  *
  79  * XXX - are those all the x86 tests we need?
  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 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  * XXX - ARM is a special case.  ARMv1 through ARMv5 didn't suppory
 264  * unaligned loads; ARMv6 and later support it *but* have a bit in
 265  * the system control register that the OS can set and that causes
 266  * unaligned loads to fault rather than succeeding.
 267  *
 268  * At least some OSes may set that flag, so we do *not* treat ARM
 269  * as supporting unaligned loads.  If your OS supports them on ARM,
 270  * and you want to use them, please update the tests in the #if above
 271  * to check for ARM *and* for your OS.
 272  */
 273 #define EXTRACT_BE_U_2(p) \
 274         ((uint16_t)(((uint16_t)(*((const uint8_t *)(p) + 0)) << 8) | \
 275                     ((uint16_t)(*((const uint8_t *)(p) + 1)) << 0)))
 276 #define EXTRACT_BE_S_2(p) \
 277         ((int16_t)(((uint16_t)(*((const uint8_t *)(p) + 0)) << 8) | \
 278                    ((uint16_t)(*((const uint8_t *)(p) + 1)) << 0)))
 279 #define EXTRACT_BE_U_4(p) \
 280         ((uint32_t)(((uint32_t)(*((const uint8_t *)(p) + 0)) << 24) | \
 281                     ((uint32_t)(*((const uint8_t *)(p) + 1)) << 16) | \
 282                     ((uint32_t)(*((const uint8_t *)(p) + 2)) << 8) | \
 283                     ((uint32_t)(*((const uint8_t *)(p) + 3)) << 0)))
 284 #define EXTRACT_BE_S_4(p) \
 285         ((int32_t)(((uint32_t)(*((const uint8_t *)(p) + 0)) << 24) | \
 286                    ((uint32_t)(*((const uint8_t *)(p) + 1)) << 16) | \
 287                    ((uint32_t)(*((const uint8_t *)(p) + 2)) << 8) | \
 288                    ((uint32_t)(*((const uint8_t *)(p) + 3)) << 0)))
 289 #define EXTRACT_BE_U_8(p) \
 290         ((uint64_t)(((uint64_t)(*((const uint8_t *)(p) + 0)) << 56) | \
 291                     ((uint64_t)(*((const uint8_t *)(p) + 1)) << 48) | \
 292                     ((uint64_t)(*((const uint8_t *)(p) + 2)) << 40) | \
 293                     ((uint64_t)(*((const uint8_t *)(p) + 3)) << 32) | \
 294                     ((uint64_t)(*((const uint8_t *)(p) + 4)) << 24) | \
 295                     ((uint64_t)(*((const uint8_t *)(p) + 5)) << 16) | \
 296                     ((uint64_t)(*((const uint8_t *)(p) + 6)) << 8) | \
 297                     ((uint64_t)(*((const uint8_t *)(p) + 7)) << 0)))
 298 #define EXTRACT_BE_S_8(p) \
 299         ((int64_t)(((uint64_t)(*((const uint8_t *)(p) + 0)) << 56) | \
 300                    ((uint64_t)(*((const uint8_t *)(p) + 1)) << 48) | \
 301                    ((uint64_t)(*((const uint8_t *)(p) + 2)) << 40) | \
 302                    ((uint64_t)(*((const uint8_t *)(p) + 3)) << 32) | \
 303                    ((uint64_t)(*((const uint8_t *)(p) + 4)) << 24) | \
 304                    ((uint64_t)(*((const uint8_t *)(p) + 5)) << 16) | \
 305                    ((uint64_t)(*((const uint8_t *)(p) + 6)) << 8) | \
 306                    ((uint64_t)(*((const uint8_t *)(p) + 7)) << 0)))
 307
 308 /*
 309  * Extract an IPv4 address, which is in network byte order, and not
 310  * necessarily aligned, and provide the result in host byte order.
 311  */
 312 #define EXTRACT_IPV4_TO_HOST_ORDER(p) \
 313         ((uint32_t)(((uint32_t)(*((const uint8_t *)(p) + 0)) << 24) | \
 314                     ((uint32_t)(*((const uint8_t *)(p) + 1)) << 16) | \
 315                     ((uint32_t)(*((const uint8_t *)(p) + 2)) << 8) | \
 316                     ((uint32_t)(*((const uint8_t *)(p) + 3)) << 0)))
 317 #endif /* unaligned access checks */
 318
 319 /*
 320  * Extract numerical values in *host* byte order.  (Some metadata
 321  * headers are in the byte order of the host that wrote the file,
 322  * and libpcap translate them to the byte order of the host
 323  * reading the file.  This means that if a program on that host
 324  * reads with libpcap and writes to a new file, the new file will
 325  * be written in the byte order of the host writing the file.  Thus,
 326  * the magic number in pcap files and byte-order magic in pcapng
 327  * files can be used to determine the byte order in those metadata
 328  * headers.)
 329  *
 330  * XXX - on platforms that can do unaligned accesses, just cast and
 331  * dereference the pointer.
 332  */
 333 static inline uint16_t
 334 EXTRACT_HE_U_2(const void *p)
 335 {
 336         uint16_t val;
 337
 338         UNALIGNED_MEMCPY(&val, p, sizeof(uint16_t));
 339         return val;
 340 }
 341
 342 static inline int16_t
 343 EXTRACT_HE_S_2(const void *p)
 344 {
 345         int16_t val;
 346
 347         UNALIGNED_MEMCPY(&val, p, sizeof(int16_t));
 348         return val;
 349 }
 350
 351 static inline uint32_t
 352 EXTRACT_HE_U_4(const void *p)
 353 {
 354         uint32_t val;
 355
 356         UNALIGNED_MEMCPY(&val, p, sizeof(uint32_t));
 357         return val;
 358 }
 359
 360 static inline int32_t
 361 EXTRACT_HE_S_4(const void *p)
 362 {
 363         int32_t val;
 364
 365         UNALIGNED_MEMCPY(&val, p, sizeof(int32_t));
 366         return val;
 367 }
 368
 369 /*
 370  * Extract an IPv4 address, which is in network byte order, and which
 371  * is not necessarily aligned on a 4-byte boundary, and provide the
 372  * result in network byte order.
 373  *
 374  * This works the same way regardless of the host's byte order.
 375  */
 376 static inline uint32_t
 377 EXTRACT_IPV4_TO_NETWORK_ORDER(const void *p)
 378 {
 379         uint32_t addr;
 380
 381         UNALIGNED_MEMCPY(&addr, p, sizeof(uint32_t));
 382         return addr;
 383 }
 384
 385 /*
 386  * Non-power-of-2 sizes.
 387  */
 388 #define EXTRACT_BE_U_3(p) \
 389         ((uint32_t)(((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_S_3(p) \
 394         (((*((const uint8_t *)(p) + 0)) & 0x80) ? \
 395           ((int32_t)(((uint32_t)(*((const uint8_t *)(p) + 0)) << 16) | \
 396                      ((uint32_t)(*((const uint8_t *)(p) + 1)) << 8) | \
 397                      ((uint32_t)(*((const uint8_t *)(p) + 2)) << 0))) : \
 398           ((int32_t)(0xFF000000U | \
 399                      ((uint32_t)(*((const uint8_t *)(p) + 0)) << 16) | \
 400                      ((uint32_t)(*((const uint8_t *)(p) + 1)) << 8) | \
 401                      ((uint32_t)(*((const uint8_t *)(p) + 2)) << 0))))
 402
 403 #define EXTRACT_BE_U_5(p) \
 404         ((uint64_t)(((uint64_t)(*((const uint8_t *)(p) + 0)) << 32) | \
 405                     ((uint64_t)(*((const uint8_t *)(p) + 1)) << 24) | \
 406                     ((uint64_t)(*((const uint8_t *)(p) + 2)) << 16) | \
 407                     ((uint64_t)(*((const uint8_t *)(p) + 3)) << 8) | \
 408                     ((uint64_t)(*((const uint8_t *)(p) + 4)) << 0)))
 409
 410 #define EXTRACT_BE_S_5(p) \
 411         (((*((const uint8_t *)(p) + 0)) & 0x80) ? \
 412           ((int64_t)(((uint64_t)(*((const uint8_t *)(p) + 0)) << 32) | \
 413                      ((uint64_t)(*((const uint8_t *)(p) + 1)) << 24) | \
 414                      ((uint64_t)(*((const uint8_t *)(p) + 2)) << 16) | \
 415                      ((uint64_t)(*((const uint8_t *)(p) + 3)) << 8) | \
 416                      ((uint64_t)(*((const uint8_t *)(p) + 4)) << 0))) : \
 417           ((int64_t)(INT64_T_CONSTANT(0xFFFFFF0000000000U) | \
 418                      ((uint64_t)(*((const uint8_t *)(p) + 0)) << 32) | \
 419                      ((uint64_t)(*((const uint8_t *)(p) + 1)) << 24) | \
 420                      ((uint64_t)(*((const uint8_t *)(p) + 2)) << 16) | \
 421                      ((uint64_t)(*((const uint8_t *)(p) + 3)) << 8) | \
 422                      ((uint64_t)(*((const uint8_t *)(p) + 4)) << 0))))
 423
 424 #define EXTRACT_BE_U_6(p) \
 425         ((uint64_t)(((uint64_t)(*((const uint8_t *)(p) + 0)) << 40) | \
 426                     ((uint64_t)(*((const uint8_t *)(p) + 1)) << 32) | \
 427                     ((uint64_t)(*((const uint8_t *)(p) + 2)) << 24) | \
 428                     ((uint64_t)(*((const uint8_t *)(p) + 3)) << 16) | \
 429                     ((uint64_t)(*((const uint8_t *)(p) + 4)) << 8) | \
 430                     ((uint64_t)(*((const uint8_t *)(p) + 5)) << 0)))
 431
 432 #define EXTRACT_BE_S_6(p) \
 433         (((*((const uint8_t *)(p) + 0)) & 0x80) ? \
 434            ((int64_t)(((uint64_t)(*((const uint8_t *)(p) + 0)) << 40) | \
 435                       ((uint64_t)(*((const uint8_t *)(p) + 1)) << 32) | \
 436                       ((uint64_t)(*((const uint8_t *)(p) + 2)) << 24) | \
 437                       ((uint64_t)(*((const uint8_t *)(p) + 3)) << 16) | \
 438                       ((uint64_t)(*((const uint8_t *)(p) + 4)) << 8) | \
 439                       ((uint64_t)(*((const uint8_t *)(p) + 5)) << 0))) : \
 440           ((int64_t)(INT64_T_CONSTANT(0xFFFFFFFF00000000U) | \
 441                       ((uint64_t)(*((const uint8_t *)(p) + 0)) << 40) | \
 442                       ((uint64_t)(*((const uint8_t *)(p) + 1)) << 32) | \
 443                       ((uint64_t)(*((const uint8_t *)(p) + 2)) << 24) | \
 444                       ((uint64_t)(*((const uint8_t *)(p) + 3)) << 16) | \
 445                       ((uint64_t)(*((const uint8_t *)(p) + 4)) << 8) | \
 446                       ((uint64_t)(*((const uint8_t *)(p) + 5)) << 0))))
 447
 448 #define EXTRACT_BE_U_7(p) \
 449         ((uint64_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
 457 #define EXTRACT_BE_S_7(p) \
 458         (((*((const uint8_t *)(p) + 0)) & 0x80) ? \
 459           ((int64_t)(((uint64_t)(*((const uint8_t *)(p) + 0)) << 48) | \
 460                      ((uint64_t)(*((const uint8_t *)(p) + 1)) << 40) | \
 461                      ((uint64_t)(*((const uint8_t *)(p) + 2)) << 32) | \
 462                      ((uint64_t)(*((const uint8_t *)(p) + 3)) << 24) | \
 463                      ((uint64_t)(*((const uint8_t *)(p) + 4)) << 16) | \
 464                      ((uint64_t)(*((const uint8_t *)(p) + 5)) << 8) | \
 465                      ((uint64_t)(*((const uint8_t *)(p) + 6)) << 0))) : \
 466             ((int64_t)(INT64_T_CONSTANT(0xFFFFFFFFFF000000U) | \
 467                      ((uint64_t)(*((const uint8_t *)(p) + 0)) << 48) | \
 468                      ((uint64_t)(*((const uint8_t *)(p) + 1)) << 40) | \
 469                      ((uint64_t)(*((const uint8_t *)(p) + 2)) << 32) | \
 470                      ((uint64_t)(*((const uint8_t *)(p) + 3)) << 24) | \
 471                      ((uint64_t)(*((const uint8_t *)(p) + 4)) << 16) | \
 472                      ((uint64_t)(*((const uint8_t *)(p) + 5)) << 8) | \
 473                      ((uint64_t)(*((const uint8_t *)(p) + 6)) << 0))))
 474
 475 /*
 476  * Macros to extract possibly-unaligned little-endian integral values.
 477  * XXX - do loads on little-endian machines that support unaligned loads?
 478  */
 479 #define EXTRACT_LE_U_2(p) \
 480         ((uint16_t)(((uint16_t)(*((const uint8_t *)(p) + 1)) << 8) | \
 481                     ((uint16_t)(*((const uint8_t *)(p) + 0)) << 0)))
 482 #define EXTRACT_LE_S_2(p) \
 483         ((int16_t)(((uint16_t)(*((const uint8_t *)(p) + 1)) << 8) | \
 484                    ((uint16_t)(*((const uint8_t *)(p) + 0)) << 0)))
 485 #define EXTRACT_LE_U_4(p) \
 486         ((uint32_t)(((uint32_t)(*((const uint8_t *)(p) + 3)) << 24) | \
 487                     ((uint32_t)(*((const uint8_t *)(p) + 2)) << 16) | \
 488                     ((uint32_t)(*((const uint8_t *)(p) + 1)) << 8) | \
 489                     ((uint32_t)(*((const uint8_t *)(p) + 0)) << 0)))
 490 #define EXTRACT_LE_S_4(p) \
 491         ((int32_t)(((uint32_t)(*((const uint8_t *)(p) + 3)) << 24) | \
 492                    ((uint32_t)(*((const uint8_t *)(p) + 2)) << 16) | \
 493                    ((uint32_t)(*((const uint8_t *)(p) + 1)) << 8) | \
 494                    ((uint32_t)(*((const uint8_t *)(p) + 0)) << 0)))
 495 #define EXTRACT_LE_U_8(p) \
 496         ((uint64_t)(((uint64_t)(*((const uint8_t *)(p) + 7)) << 56) | \
 497                     ((uint64_t)(*((const uint8_t *)(p) + 6)) << 48) | \
 498                     ((uint64_t)(*((const uint8_t *)(p) + 5)) << 40) | \
 499                     ((uint64_t)(*((const uint8_t *)(p) + 4)) << 32) | \
 500                     ((uint64_t)(*((const uint8_t *)(p) + 3)) << 24) | \
 501                     ((uint64_t)(*((const uint8_t *)(p) + 2)) << 16) | \
 502                     ((uint64_t)(*((const uint8_t *)(p) + 1)) << 8) | \
 503                     ((uint64_t)(*((const uint8_t *)(p) + 0)) << 0)))
 504 #define EXTRACT_LE_S_8(p) \
 505         ((int64_t)(((uint64_t)(*((const uint8_t *)(p) + 7)) << 56) | \
 506                    ((uint64_t)(*((const uint8_t *)(p) + 6)) << 48) | \
 507                    ((uint64_t)(*((const uint8_t *)(p) + 5)) << 40) | \
 508                    ((uint64_t)(*((const uint8_t *)(p) + 4)) << 32) | \
 509                    ((uint64_t)(*((const uint8_t *)(p) + 3)) << 24) | \
 510                    ((uint64_t)(*((const uint8_t *)(p) + 2)) << 16) | \
 511                    ((uint64_t)(*((const uint8_t *)(p) + 1)) << 8) | \
 512                    ((uint64_t)(*((const uint8_t *)(p) + 0)) << 0)))
 513
 514 /*
 515  * Non-power-of-2 sizes.
 516  */
 517
 518 #define EXTRACT_LE_U_3(p) \
 519         ((uint32_t)(((uint32_t)(*((const uint8_t *)(p) + 2)) << 16) | \
 520                     ((uint32_t)(*((const uint8_t *)(p) + 1)) << 8) | \
 521                     ((uint32_t)(*((const uint8_t *)(p) + 0)) << 0)))
 522 #define EXTRACT_LE_S_3(p) \
 523         ((int32_t)(((uint32_t)(*((const uint8_t *)(p) + 2)) << 16) | \
 524                    ((uint32_t)(*((const uint8_t *)(p) + 1)) << 8) | \
 525                    ((uint32_t)(*((const uint8_t *)(p) + 0)) << 0)))
 526 #define EXTRACT_LE_U_5(p) \
 527         ((uint64_t)(((uint64_t)(*((const uint8_t *)(p) + 4)) << 32) |   \
 528                     ((uint64_t)(*((const uint8_t *)(p) + 3)) << 24) |   \
 529                     ((uint64_t)(*((const uint8_t *)(p) + 2)) << 16) |   \
 530                     ((uint64_t)(*((const uint8_t *)(p) + 1)) << 8) |    \
 531                     ((uint64_t)(*((const uint8_t *)(p) + 0)) << 0)))
 532 #define EXTRACT_LE_U_6(p) \
 533         ((uint64_t)(((uint64_t)(*((const uint8_t *)(p) + 5)) << 40) |   \
 534                     ((uint64_t)(*((const uint8_t *)(p) + 4)) << 32) |   \
 535                     ((uint64_t)(*((const uint8_t *)(p) + 3)) << 24) |   \
 536                     ((uint64_t)(*((const uint8_t *)(p) + 2)) << 16) |   \
 537                     ((uint64_t)(*((const uint8_t *)(p) + 1)) << 8) |    \
 538                     ((uint64_t)(*((const uint8_t *)(p) + 0)) << 0)))
 539 #define EXTRACT_LE_U_7(p) \
 540         ((uint64_t)(((uint64_t)(*((const uint8_t *)(p) + 6)) << 48) |   \
 541                     ((uint64_t)(*((const uint8_t *)(p) + 5)) << 40) |   \
 542                     ((uint64_t)(*((const uint8_t *)(p) + 4)) << 32) |   \
 543                     ((uint64_t)(*((const uint8_t *)(p) + 3)) << 24) |   \
 544                     ((uint64_t)(*((const uint8_t *)(p) + 2)) << 16) |   \
 545                     ((uint64_t)(*((const uint8_t *)(p) + 1)) << 8) |    \
 546                     ((uint64_t)(*((const uint8_t *)(p) + 0)) << 0)))
 547
 548 /*
 549  * Macros to check the presence of the values in question.
 550  */
 551 #define ND_TTEST_1(p) ND_TTEST_LEN((p), 1)
 552 #define ND_TCHECK_1(p) ND_TCHECK_LEN((p), 1)
 553
 554 #define ND_TTEST_2(p) ND_TTEST_LEN((p), 2)
 555 #define ND_TCHECK_2(p) ND_TCHECK_LEN((p), 2)
 556
 557 #define ND_TTEST_3(p) ND_TTEST_LEN((p), 3)
 558 #define ND_TCHECK_3(p) ND_TCHECK_LEN((p), 3)
 559
 560 #define ND_TTEST_4(p) ND_TTEST_LEN((p), 4)
 561 #define ND_TCHECK_4(p) ND_TCHECK_LEN((p), 4)
 562
 563 #define ND_TTEST_5(p) ND_TTEST_LEN((p), 5)
 564 #define ND_TCHECK_5(p) ND_TCHECK_LEN((p), 5)
 565
 566 #define ND_TTEST_6(p) ND_TTEST_LEN((p), 6)
 567 #define ND_TCHECK_6(p) ND_TCHECK_LEN((p), 6)
 568
 569 #define ND_TTEST_7(p) ND_TTEST_LEN((p), 7)
 570 #define ND_TCHECK_7(p) ND_TCHECK_LEN((p), 7)
 571
 572 #define ND_TTEST_8(p) ND_TTEST_LEN((p), 8)
 573 #define ND_TCHECK_8(p) ND_TCHECK_LEN((p), 8)
 574
 575 #define ND_TTEST_16(p) ND_TTEST_LEN((p), 16)
 576 #define ND_TCHECK_16(p) ND_TCHECK_LEN((p), 16)
 577
 578 static inline NORETURN void
 579 nd_trunc_longjmp(netdissect_options *ndo)
 580 {
 581         longjmp(ndo->ndo_early_end, ND_TRUNCATED);
 582 }
 583
 584 /* get_u_1 and get_s_1 */
 585
 586 static inline uint8_t
 587 get_u_1(netdissect_options *ndo, const u_char *p)
 588 {
 589         if (!ND_TTEST_1(p))
 590                 nd_trunc_longjmp(ndo);
 591         return EXTRACT_U_1(p);
 592 }
 593
 594 static inline int8_t
 595 get_s_1(netdissect_options *ndo, const u_char *p)
 596 {
 597         if (!ND_TTEST_1(p))
 598                 nd_trunc_longjmp(ndo);
 599         return EXTRACT_S_1(p);
 600 }
 601
 602 /* get_be_u_N */
 603
 604 static inline uint16_t
 605 get_be_u_2(netdissect_options *ndo, const u_char *p)
 606 {
 607         if (!ND_TTEST_2(p))
 608                 nd_trunc_longjmp(ndo);
 609         return EXTRACT_BE_U_2(p);
 610 }
 611
 612 static inline uint32_t
 613 get_be_u_3(netdissect_options *ndo, const u_char *p)
 614 {
 615         if (!ND_TTEST_3(p))
 616                 nd_trunc_longjmp(ndo);
 617         return EXTRACT_BE_U_3(p);
 618 }
 619
 620 static inline uint32_t
 621 get_be_u_4(netdissect_options *ndo, const u_char *p)
 622 {
 623         if (!ND_TTEST_4(p))
 624                 nd_trunc_longjmp(ndo);
 625         return EXTRACT_BE_U_4(p);
 626 }
 627
 628 static inline uint64_t
 629 get_be_u_5(netdissect_options *ndo, const u_char *p)
 630 {
 631         if (!ND_TTEST_5(p))
 632                 nd_trunc_longjmp(ndo);
 633         return EXTRACT_BE_U_5(p);
 634 }
 635
 636 static inline uint64_t
 637 get_be_u_6(netdissect_options *ndo, const u_char *p)
 638 {
 639         if (!ND_TTEST_6(p))
 640                 nd_trunc_longjmp(ndo);
 641         return EXTRACT_BE_U_6(p);
 642 }
 643
 644 static inline uint64_t
 645 get_be_u_7(netdissect_options *ndo, const u_char *p)
 646 {
 647         if (!ND_TTEST_7(p))
 648                 nd_trunc_longjmp(ndo);
 649         return EXTRACT_BE_U_7(p);
 650 }
 651
 652 static inline uint64_t
 653 get_be_u_8(netdissect_options *ndo, const u_char *p)
 654 {
 655         if (!ND_TTEST_8(p))
 656                 nd_trunc_longjmp(ndo);
 657         return EXTRACT_BE_U_8(p);
 658 }
 659
 660 /* get_be_s_N  */
 661
 662 static inline int16_t
 663 get_be_s_2(netdissect_options *ndo, const u_char *p)
 664 {
 665         if (!ND_TTEST_2(p))
 666                 nd_trunc_longjmp(ndo);
 667         return EXTRACT_BE_S_2(p);
 668 }
 669
 670 static inline int32_t
 671 get_be_s_3(netdissect_options *ndo, const u_char *p)
 672 {
 673         if (!ND_TTEST_3(p))
 674                 nd_trunc_longjmp(ndo);
 675         return EXTRACT_BE_S_3(p);
 676 }
 677
 678 static inline int32_t
 679 get_be_s_4(netdissect_options *ndo, const u_char *p)
 680 {
 681         if (!ND_TTEST_4(p))
 682                 nd_trunc_longjmp(ndo);
 683         return EXTRACT_BE_S_4(p);
 684 }
 685
 686 static inline int64_t
 687 get_be_s_5(netdissect_options *ndo, const u_char *p)
 688 {
 689         if (!ND_TTEST_5(p))
 690                 nd_trunc_longjmp(ndo);
 691         return EXTRACT_BE_S_5(p);
 692 }
 693
 694 static inline int64_t
 695 get_be_s_6(netdissect_options *ndo, const u_char *p)
 696 {
 697         if (!ND_TTEST_6(p))
 698                 nd_trunc_longjmp(ndo);
 699         return EXTRACT_BE_S_6(p);
 700 }
 701
 702 static inline int64_t
 703 get_be_s_7(netdissect_options *ndo, const u_char *p)
 704 {
 705         if (!ND_TTEST_7(p))
 706                 nd_trunc_longjmp(ndo);
 707         return EXTRACT_BE_S_7(p);
 708 }
 709
 710 static inline int64_t
 711 get_be_s_8(netdissect_options *ndo, const u_char *p)
 712 {
 713         if (!ND_TTEST_8(p))
 714                 nd_trunc_longjmp(ndo);
 715         return EXTRACT_BE_S_8(p);
 716 }
 717
 718 /* get_he_u_N */
 719
 720 static inline uint16_t
 721 get_he_u_2(netdissect_options *ndo, const u_char *p)
 722 {
 723         if (!ND_TTEST_2(p))
 724                 nd_trunc_longjmp(ndo);
 725         return EXTRACT_HE_U_2(p);
 726 }
 727
 728 static inline uint32_t
 729 get_he_u_4(netdissect_options *ndo, const u_char *p)
 730 {
 731         if (!ND_TTEST_4(p))
 732                 nd_trunc_longjmp(ndo);
 733         return EXTRACT_HE_U_4(p);
 734 }
 735
 736 /* get_he_s_N */
 737
 738 static inline int16_t
 739 get_he_s_2(netdissect_options *ndo, const u_char *p)
 740 {
 741         if (!ND_TTEST_2(p))
 742                 nd_trunc_longjmp(ndo);
 743         return EXTRACT_HE_S_2(p);
 744 }
 745
 746 static inline int32_t
 747 get_he_s_4(netdissect_options *ndo, const u_char *p)
 748 {
 749         if (!ND_TTEST_4(p))
 750                 nd_trunc_longjmp(ndo);
 751         return EXTRACT_HE_S_4(p);
 752 }
 753
 754 /* get_le_u_N */
 755
 756 static inline uint16_t
 757 get_le_u_2(netdissect_options *ndo, const u_char *p)
 758 {
 759         if (!ND_TTEST_2(p))
 760                 nd_trunc_longjmp(ndo);
 761         return EXTRACT_LE_U_2(p);
 762 }
 763
 764 static inline uint32_t
 765 get_le_u_3(netdissect_options *ndo, const u_char *p)
 766 {
 767         if (!ND_TTEST_3(p))
 768                 nd_trunc_longjmp(ndo);
 769         return EXTRACT_LE_U_3(p);
 770 }
 771
 772 static inline uint32_t
 773 get_le_u_4(netdissect_options *ndo, const u_char *p)
 774 {
 775         if (!ND_TTEST_4(p))
 776                 nd_trunc_longjmp(ndo);
 777         return EXTRACT_LE_U_4(p);
 778 }
 779
 780 static inline uint64_t
 781 get_le_u_5(netdissect_options *ndo, const u_char *p)
 782 {
 783         if (!ND_TTEST_5(p))
 784                 nd_trunc_longjmp(ndo);
 785         return EXTRACT_LE_U_5(p);
 786 }
 787
 788 static inline uint64_t
 789 get_le_u_6(netdissect_options *ndo, const u_char *p)
 790 {
 791         if (!ND_TTEST_6(p))
 792                 nd_trunc_longjmp(ndo);
 793         return EXTRACT_LE_U_6(p);
 794 }
 795
 796 static inline uint64_t
 797 get_le_u_7(netdissect_options *ndo, const u_char *p)
 798 {
 799         if (!ND_TTEST_7(p))
 800                 nd_trunc_longjmp(ndo);
 801         return EXTRACT_LE_U_7(p);
 802 }
 803
 804 static inline uint64_t
 805 get_le_u_8(netdissect_options *ndo, const u_char *p)
 806 {
 807         if (!ND_TTEST_8(p))
 808                 nd_trunc_longjmp(ndo);
 809         return EXTRACT_LE_U_8(p);
 810 }
 811
 812 /* get_le_s_N */
 813
 814 static inline int16_t
 815 get_le_s_2(netdissect_options *ndo, const u_char *p)
 816 {
 817         if (!ND_TTEST_2(p))
 818                 nd_trunc_longjmp(ndo);
 819         return EXTRACT_LE_S_2(p);
 820 }
 821
 822 static inline int32_t
 823 get_le_s_3(netdissect_options *ndo, const u_char *p)
 824 {
 825         if (!ND_TTEST_3(p))
 826                 nd_trunc_longjmp(ndo);
 827         return EXTRACT_LE_S_3(p);
 828 }
 829
 830 static inline int32_t
 831 get_le_s_4(netdissect_options *ndo, const u_char *p)
 832 {
 833         if (!ND_TTEST_4(p))
 834                 nd_trunc_longjmp(ndo);
 835         return EXTRACT_LE_S_4(p);
 836 }
 837
 838 static inline int64_t
 839 get_le_s_8(netdissect_options *ndo, const u_char *p)
 840 {
 841         if (!ND_TTEST_8(p))
 842                 nd_trunc_longjmp(ndo);
 843         return EXTRACT_LE_S_8(p);
 844 }
 845
 846 /* get_ipv4_to_{host|network]_order */
 847
 848 static inline uint32_t
 849 get_ipv4_to_host_order(netdissect_options *ndo, const u_char *p)
 850 {
 851         if (!ND_TTEST_4(p))
 852                 nd_trunc_longjmp(ndo);
 853         return EXTRACT_IPV4_TO_HOST_ORDER(p);
 854 }
 855
 856 static inline uint32_t
 857 get_ipv4_to_network_order(netdissect_options *ndo, const u_char *p)
 858 {
 859         if (!ND_TTEST_4(p))
 860                 nd_trunc_longjmp(ndo);
 861         return EXTRACT_IPV4_TO_NETWORK_ORDER(p);
 862 }
 863
 864 static inline void
 865 get_cpy_bytes(netdissect_options *ndo, u_char *dst, const u_char *p, size_t len)
 866 {
 867         if (!ND_TTEST_LEN(p, len))
 868                 nd_trunc_longjmp(ndo);
 869         UNALIGNED_MEMCPY(dst, p, len);
 870 }
 871
 872 #define GET_U_1(p) get_u_1(ndo, (const u_char *)(p))
 873 #define GET_S_1(p) get_s_1(ndo, (const u_char *)(p))
 874
 875 #define GET_BE_U_2(p) get_be_u_2(ndo, (const u_char *)(p))
 876 #define GET_BE_U_3(p) get_be_u_3(ndo, (const u_char *)(p))
 877 #define GET_BE_U_4(p) get_be_u_4(ndo, (const u_char *)(p))
 878 #define GET_BE_U_5(p) get_be_u_5(ndo, (const u_char *)(p))
 879 #define GET_BE_U_6(p) get_be_u_6(ndo, (const u_char *)(p))
 880 #define GET_BE_U_7(p) get_be_u_7(ndo, (const u_char *)(p))
 881 #define GET_BE_U_8(p) get_be_u_8(ndo, (const u_char *)(p))
 882
 883 #define GET_BE_S_2(p) get_be_s_2(ndo, (const u_char *)(p))
 884 #define GET_BE_S_3(p) get_be_s_3(ndo, (const u_char *)(p))
 885 #define GET_BE_S_4(p) get_be_s_4(ndo, (const u_char *)(p))
 886 #define GET_BE_S_5(p) get_be_s_5(ndo, (const u_char *)(p))
 887 #define GET_BE_S_6(p) get_be_s_6(ndo, (const u_char *)(p))
 888 #define GET_BE_S_7(p) get_be_s_7(ndo, (const u_char *)(p))
 889 #define GET_BE_S_8(p) get_be_s_8(ndo, (const u_char *)(p))
 890
 891 #define GET_HE_U_2(p) get_he_u_2(ndo, (const u_char *)(p))
 892 #define GET_HE_U_4(p) get_he_u_4(ndo, (const u_char *)(p))
 893
 894 #define GET_HE_S_2(p) get_he_s_2(ndo, (const u_char *)(p))
 895 #define GET_HE_S_4(p) get_he_s_4(ndo, (const u_char *)(p))
 896
 897 #define GET_LE_U_2(p) get_le_u_2(ndo, (const u_char *)(p))
 898 #define GET_LE_U_3(p) get_le_u_3(ndo, (const u_char *)(p))
 899 #define GET_LE_U_4(p) get_le_u_4(ndo, (const u_char *)(p))
 900 #define GET_LE_U_5(p) get_le_u_5(ndo, (const u_char *)(p))
 901 #define GET_LE_U_6(p) get_le_u_6(ndo, (const u_char *)(p))
 902 #define GET_LE_U_7(p) get_le_u_7(ndo, (const u_char *)(p))
 903 #define GET_LE_U_8(p) get_le_u_8(ndo, (const u_char *)(p))
 904
 905 #define GET_LE_S_2(p) get_le_s_2(ndo, (const u_char *)(p))
 906 #define GET_LE_S_3(p) get_le_s_3(ndo, (const u_char *)(p))
 907 #define GET_LE_S_4(p) get_le_s_4(ndo, (const u_char *)(p))
 908 #define GET_LE_S_8(p) get_le_s_8(ndo, (const u_char *)(p))
 909
 910 #define GET_IPV4_TO_HOST_ORDER(p) get_ipv4_to_host_order(ndo, (const u_char *)(p))
 911 #define GET_IPV4_TO_NETWORK_ORDER(p) get_ipv4_to_network_order(ndo, (const u_char *)(p))
 912
 913 #define GET_CPY_BYTES(dst, p, len) get_cpy_bytes(ndo, (u_char *)(dst), (const u_char *)(p), len)
 914
 915 #endif /* EXTRACT_H */