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
23 /*
24 * If we have versions of GCC or Clang that support an __attribute__
25 * to say "if we're building with unsigned behavior sanitization,
26 * don't complain about undefined behavior in this function", we
27 * label these functions with that attribute - we *know* it's undefined
28 * in the C standard, but we *also* know it does what we want with
29 * the ISA we're targeting and the compiler we're using.
30 *
31 * For GCC 4.9.0 and later, we use __attribute__((no_sanitize_undefined));
32 * pre-5.0 GCC doesn't have __has_attribute, and I'm not sure whether
33 * GCC or Clang first had __attribute__((no_sanitize(XXX)).
34 *
35 * For Clang, we check for __attribute__((no_sanitize(XXX)) with
36 * __has_attribute, as there are versions of Clang that support
37 * __attribute__((no_sanitize("undefined")) but don't support
38 * __attribute__((no_sanitize_undefined)).
39 *
40 * We define this here, rather than in funcattrs.h, because we
41 * only want it used here, we don't want it to be broadly used.
42 * (Any printer will get this defined, but this should at least
43 * make it harder for people to find.)
44 */
45 #if defined(__GNUC__) && ((__GNUC__ * 100 + __GNUC_MINOR__) >= 409)
46 #define UNALIGNED_OK __attribute__((no_sanitize_undefined))
47 #elif __has_attribute(no_sanitize)
48 #define UNALIGNED_OK __attribute__((no_sanitize("undefined")))
49 #else
50 #define UNALIGNED_OK
51 #endif
52
53 #ifdef __NetBSD__
54 #include <string.h>
55
56 /*
57 * Do it the portable way and let the compiler optimize the code
58 */
EXTRACT_16BITS(const void * p)59 static inline uint16_t EXTRACT_16BITS(const void *p)
60 {
61 uint16_t t;
62 memcpy(&t, p, sizeof(t));
63 return ntohs(t);
64 }
65
EXTRACT_24BITS(const void * p)66 static inline uint32_t EXTRACT_24BITS(const void *p)
67 {
68 uint8_t t[3];
69 memcpy(t, p, sizeof(t));
70 return
71 ((uint32_t)t[0] << 16) |
72 ((uint32_t)t[1] << 8) |
73 t[2];
74 }
75
EXTRACT_32BITS(const void * p)76 static inline uint32_t EXTRACT_32BITS(const void *p)
77 {
78 uint32_t t;
79 memcpy(&t, p, sizeof(t));
80 return ntohl(t);
81 }
82
83
EXTRACT_48BITS(const void * p)84 static inline uint64_t EXTRACT_48BITS(const void *p)
85 {
86 uint8_t t[6];
87 memcpy(t, p, sizeof(t));
88 return
89 ((uint64_t)t[0] << 40) |
90 ((uint64_t)t[1] << 32) |
91 ((uint64_t)t[2] << 24) |
92 ((uint64_t)t[3] << 16) |
93 ((uint64_t)t[4] << 8) |
94 t[5];
95 }
96
EXTRACT_64BITS(const void * p)97 static inline uint64_t EXTRACT_64BITS(const void *p)
98 {
99 uint32_t t[2];
100 memcpy(&t[0], p, sizeof(t[0]));
101 memcpy(&t[1], (const uint8_t *)p + sizeof(t[0]), sizeof(t[1]));
102 return ((uint64_t)ntohl(t[0]) << 32) | ntohl(t[1]);
103 }
104
EXTRACT_LE_8BITS(const void * p)105 static inline uint8_t EXTRACT_LE_8BITS(const void *p)
106 {
107 uint8_t t[1];
108 memcpy(t, p, sizeof(t));
109 return t[0];
110 }
111
EXTRACT_LE_16BITS(const void * p)112 static inline uint16_t EXTRACT_LE_16BITS(const void *p)
113 {
114 uint8_t t[2];
115 memcpy(t, p, sizeof(t));
116 return
117 ((uint16_t)t[1] << 8) |
118 t[0];
119 }
120
EXTRACT_LE_24BITS(const void * p)121 static inline uint32_t EXTRACT_LE_24BITS(const void *p)
122 {
123 uint8_t t[3];
124 memcpy(t, p, sizeof(t));
125 return
126 ((uint32_t)t[2] << 16) |
127 ((uint32_t)t[1] << 8) |
128 t[0];
129 }
130
EXTRACT_LE_32BITS(const void * p)131 static inline uint32_t EXTRACT_LE_32BITS(const void *p)
132 {
133 uint8_t t[4];
134 memcpy(t, p, sizeof(t));
135 return
136 ((uint32_t)t[3] << 24) |
137 ((uint32_t)t[2] << 16) |
138 ((uint32_t)t[1] << 8) |
139 t[0];
140 }
141
EXTRACT_LE_64BITS(const void * p)142 static inline uint64_t EXTRACT_LE_64BITS(const void *p)
143 {
144 uint8_t t[8];
145 memcpy(&t, p, sizeof(t));
146 return
147 ((uint64_t)t[7] << 56) |
148 ((uint64_t)t[6] << 48) |
149 ((uint64_t)t[5] << 40) |
150 ((uint64_t)t[4] << 32) |
151 ((uint64_t)t[3] << 24) |
152 ((uint64_t)t[2] << 16) |
153 ((uint64_t)t[1] << 8) |
154 t[0];
155 }
156
157 #define EXTRACT_8BITS(p) EXTRACT_LE_8BITS(p)
158
159 #else /* Fast & Loose */
160 /*
161 * For 8-bit values; provided for the sake of completeness. Byte order
162 * isn't relevant, and alignment isn't an issue.
163 */
164 #define EXTRACT_8BITS(p) (*(p))
165 #define EXTRACT_LE_8BITS(p) (*(p))
166
167 /*
168 * Inline functions or macros to extract possibly-unaligned big-endian
169 * integral values.
170 */
171 #include "funcattrs.h"
172
173 #ifdef LBL_ALIGN
174 /*
175 * The processor doesn't natively handle unaligned loads.
176 */
177 #if defined(__GNUC__) && defined(HAVE___ATTRIBUTE__) && \
178 (defined(__alpha) || defined(__alpha__) || \
179 defined(__mips) || defined(__mips__))
180
181 /*
182 * This is a GCC-compatible compiler and we have __attribute__, which
183 * we assume that mean we have __attribute__((packed)), and this is
184 * MIPS or Alpha, which has instructions that can help when doing
185 * unaligned loads.
186 *
187 * Declare packed structures containing a uint16_t and a uint32_t,
188 * cast the pointer to point to one of those, and fetch through it;
189 * the GCC manual doesn't appear to explicitly say that
190 * __attribute__((packed)) causes the compiler to generate unaligned-safe
191 * code, but it apppears to do so.
192 *
193 * We do this in case the compiler can generate code using those
194 * instructions to do an unaligned load and pass stuff to "ntohs()" or
195 * "ntohl()", which might be better than than the code to fetch the
196 * bytes one at a time and assemble them. (That might not be the
197 * case on a little-endian platform, such as DEC's MIPS machines and
198 * Alpha machines, where "ntohs()" and "ntohl()" might not be done
199 * inline.)
200 *
201 * We do this only for specific architectures because, for example,
202 * at least some versions of GCC, when compiling for 64-bit SPARC,
203 * generate code that assumes alignment if we do this.
204 *
205 * XXX - add other architectures and compilers as possible and
206 * appropriate.
207 *
208 * HP's C compiler, indicated by __HP_cc being defined, supports
209 * "#pragma unaligned N" in version A.05.50 and later, where "N"
210 * specifies a number of bytes at which the typedef on the next
211 * line is aligned, e.g.
212 *
213 * #pragma unalign 1
214 * typedef uint16_t unaligned_uint16_t;
215 *
216 * to define unaligned_uint16_t as a 16-bit unaligned data type.
217 * This could be presumably used, in sufficiently recent versions of
218 * the compiler, with macros similar to those below. This would be
219 * useful only if that compiler could generate better code for PA-RISC
220 * or Itanium than would be generated by a bunch of shifts-and-ORs.
221 *
222 * DEC C, indicated by __DECC being defined, has, at least on Alpha,
223 * an __unaligned qualifier that can be applied to pointers to get the
224 * compiler to generate code that does unaligned loads and stores when
225 * dereferencing the pointer in question.
226 *
227 * XXX - what if the native C compiler doesn't support
228 * __attribute__((packed))? How can we get it to generate unaligned
229 * accesses for *specific* items?
230 */
231 typedef struct {
232 uint16_t val;
233 } __attribute__((packed)) unaligned_uint16_t;
234
235 typedef struct {
236 uint32_t val;
237 } __attribute__((packed)) unaligned_uint32_t;
238
239 UNALIGNED_OK static inline uint16_t
EXTRACT_16BITS(const void * p)240 EXTRACT_16BITS(const void *p)
241 {
242 return ((uint16_t)ntohs(((const unaligned_uint16_t *)(p))->val));
243 }
244
245 UNALIGNED_OK static inline uint32_t
EXTRACT_32BITS(const void * p)246 EXTRACT_32BITS(const void *p)
247 {
248 return ((uint32_t)ntohl(((const unaligned_uint32_t *)(p))->val));
249 }
250
251 UNALIGNED_OK static inline uint64_t
EXTRACT_64BITS(const void * p)252 EXTRACT_64BITS(const void *p)
253 {
254 return ((uint64_t)(((uint64_t)ntohl(((const unaligned_uint32_t *)(p) + 0)->val)) << 32 |
255 ((uint64_t)ntohl(((const unaligned_uint32_t *)(p) + 1)->val)) << 0));
256 }
257
258 #else /* have to do it a byte at a time */
259 /*
260 * This isn't a GCC-compatible compiler, we don't have __attribute__,
261 * or we do but we don't know of any better way with this instruction
262 * set to do unaligned loads, so do unaligned loads of big-endian
263 * quantities the hard way - fetch the bytes one at a time and
264 * assemble them.
265 */
266 #define EXTRACT_16BITS(p) \
267 ((uint16_t)(((uint16_t)(*((const uint8_t *)(p) + 0)) << 8) | \
268 ((uint16_t)(*((const uint8_t *)(p) + 1)) << 0)))
269 #define EXTRACT_32BITS(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_64BITS(p) \
275 ((uint64_t)(((uint64_t)(*((const uint8_t *)(p) + 0)) << 56) | \
276 ((uint64_t)(*((const uint8_t *)(p) + 1)) << 48) | \
277 ((uint64_t)(*((const uint8_t *)(p) + 2)) << 40) | \
278 ((uint64_t)(*((const uint8_t *)(p) + 3)) << 32) | \
279 ((uint64_t)(*((const uint8_t *)(p) + 4)) << 24) | \
280 ((uint64_t)(*((const uint8_t *)(p) + 5)) << 16) | \
281 ((uint64_t)(*((const uint8_t *)(p) + 6)) << 8) | \
282 ((uint64_t)(*((const uint8_t *)(p) + 7)) << 0)))
283 #endif /* must special-case unaligned accesses */
284 #else /* LBL_ALIGN */
285 /*
286 * The processor natively handles unaligned loads, so we can just
287 * cast the pointer and fetch through it.
288 */
289 static inline uint16_t UNALIGNED_OK
EXTRACT_16BITS(const void * p)290 EXTRACT_16BITS(const void *p)
291 {
292 return ((uint16_t)ntohs(*(const uint16_t *)(p)));
293 }
294
295 static inline uint32_t UNALIGNED_OK
EXTRACT_32BITS(const void * p)296 EXTRACT_32BITS(const void *p)
297 {
298 return ((uint32_t)ntohl(*(const uint32_t *)(p)));
299 }
300
301 static inline uint64_t UNALIGNED_OK
EXTRACT_64BITS(const void * p)302 EXTRACT_64BITS(const void *p)
303 {
304 return ((uint64_t)(((uint64_t)ntohl(*((const uint32_t *)(p) + 0))) << 32 |
305 ((uint64_t)ntohl(*((const uint32_t *)(p) + 1))) << 0));
306
307 }
308
309 #endif /* LBL_ALIGN */
310
311 #define EXTRACT_24BITS(p) \
312 ((uint32_t)(((uint32_t)(*((const uint8_t *)(p) + 0)) << 16) | \
313 ((uint32_t)(*((const uint8_t *)(p) + 1)) << 8) | \
314 ((uint32_t)(*((const uint8_t *)(p) + 2)) << 0)))
315
316 #define EXTRACT_40BITS(p) \
317 ((uint64_t)(((uint64_t)(*((const uint8_t *)(p) + 0)) << 32) | \
318 ((uint64_t)(*((const uint8_t *)(p) + 1)) << 24) | \
319 ((uint64_t)(*((const uint8_t *)(p) + 2)) << 16) | \
320 ((uint64_t)(*((const uint8_t *)(p) + 3)) << 8) | \
321 ((uint64_t)(*((const uint8_t *)(p) + 4)) << 0)))
322
323 #define EXTRACT_48BITS(p) \
324 ((uint64_t)(((uint64_t)(*((const uint8_t *)(p) + 0)) << 40) | \
325 ((uint64_t)(*((const uint8_t *)(p) + 1)) << 32) | \
326 ((uint64_t)(*((const uint8_t *)(p) + 2)) << 24) | \
327 ((uint64_t)(*((const uint8_t *)(p) + 3)) << 16) | \
328 ((uint64_t)(*((const uint8_t *)(p) + 4)) << 8) | \
329 ((uint64_t)(*((const uint8_t *)(p) + 5)) << 0)))
330
331 #define EXTRACT_56BITS(p) \
332 ((uint64_t)(((uint64_t)(*((const uint8_t *)(p) + 0)) << 48) | \
333 ((uint64_t)(*((const uint8_t *)(p) + 1)) << 40) | \
334 ((uint64_t)(*((const uint8_t *)(p) + 2)) << 32) | \
335 ((uint64_t)(*((const uint8_t *)(p) + 3)) << 24) | \
336 ((uint64_t)(*((const uint8_t *)(p) + 4)) << 16) | \
337 ((uint64_t)(*((const uint8_t *)(p) + 5)) << 8) | \
338 ((uint64_t)(*((const uint8_t *)(p) + 6)) << 0)))
339
340 /*
341 * Macros to extract possibly-unaligned little-endian integral values.
342 * XXX - do loads on little-endian machines that support unaligned loads?
343 */
344 #define EXTRACT_LE_16BITS(p) \
345 ((uint16_t)(((uint16_t)(*((const uint8_t *)(p) + 1)) << 8) | \
346 ((uint16_t)(*((const uint8_t *)(p) + 0)) << 0)))
347 #define EXTRACT_LE_32BITS(p) \
348 ((uint32_t)(((uint32_t)(*((const uint8_t *)(p) + 3)) << 24) | \
349 ((uint32_t)(*((const uint8_t *)(p) + 2)) << 16) | \
350 ((uint32_t)(*((const uint8_t *)(p) + 1)) << 8) | \
351 ((uint32_t)(*((const uint8_t *)(p) + 0)) << 0)))
352 #define EXTRACT_LE_24BITS(p) \
353 ((uint32_t)(((uint32_t)(*((const uint8_t *)(p) + 2)) << 16) | \
354 ((uint32_t)(*((const uint8_t *)(p) + 1)) << 8) | \
355 ((uint32_t)(*((const uint8_t *)(p) + 0)) << 0)))
356 #define EXTRACT_LE_64BITS(p) \
357 ((uint64_t)(((uint64_t)(*((const uint8_t *)(p) + 7)) << 56) | \
358 ((uint64_t)(*((const uint8_t *)(p) + 6)) << 48) | \
359 ((uint64_t)(*((const uint8_t *)(p) + 5)) << 40) | \
360 ((uint64_t)(*((const uint8_t *)(p) + 4)) << 32) | \
361 ((uint64_t)(*((const uint8_t *)(p) + 3)) << 24) | \
362 ((uint64_t)(*((const uint8_t *)(p) + 2)) << 16) | \
363 ((uint64_t)(*((const uint8_t *)(p) + 1)) << 8) | \
364 ((uint64_t)(*((const uint8_t *)(p) + 0)) << 0)))
365
366 #endif /* __NetBSD__ */
367
368 /*
369 * Macros to check the presence of the values in question.
370 */
371 #define ND_TTEST_8BITS(p) ND_TTEST2(*(p), 1)
372 #define ND_TCHECK_8BITS(p) ND_TCHECK2(*(p), 1)
373
374 #define ND_TTEST_16BITS(p) ND_TTEST2(*(p), 2)
375 #define ND_TCHECK_16BITS(p) ND_TCHECK2(*(p), 2)
376
377 #define ND_TTEST_24BITS(p) ND_TTEST2(*(p), 3)
378 #define ND_TCHECK_24BITS(p) ND_TCHECK2(*(p), 3)
379
380 #define ND_TTEST_32BITS(p) ND_TTEST2(*(p), 4)
381 #define ND_TCHECK_32BITS(p) ND_TCHECK2(*(p), 4)
382
383 #define ND_TTEST_40BITS(p) ND_TTEST2(*(p), 5)
384 #define ND_TCHECK_40BITS(p) ND_TCHECK2(*(p), 5)
385
386 #define ND_TTEST_48BITS(p) ND_TTEST2(*(p), 6)
387 #define ND_TCHECK_48BITS(p) ND_TCHECK2(*(p), 6)
388
389 #define ND_TTEST_56BITS(p) ND_TTEST2(*(p), 7)
390 #define ND_TCHECK_56BITS(p) ND_TCHECK2(*(p), 7)
391
392 #define ND_TTEST_64BITS(p) ND_TTEST2(*(p), 8)
393 #define ND_TCHECK_64BITS(p) ND_TCHECK2(*(p), 8)
394
395 #define ND_TTEST_128BITS(p) ND_TTEST2(*(p), 16)
396 #define ND_TCHECK_128BITS(p) ND_TCHECK2(*(p), 16)
397