xref: /dragonfly/contrib/tcpdump/extract.h (revision 6f5ec8b5)
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 */
916