f98de413906d62faa9f8afb4c51deeef9ce3c1d2
[strongswan.git] / src / libstrongswan / utils.h
1 /*
2 * Copyright (C) 2008-2011 Tobias Brunner
3 * Copyright (C) 2008 Martin Willi
4 * Hochschule fuer Technik Rapperswil
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2 of the License, or (at your
9 * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
10 *
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
13 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * for more details.
15 */
16
17 /**
18 * @defgroup utils utils
19 * @{ @ingroup libstrongswan
20 */
21
22 #ifndef UTILS_H_
23 #define UTILS_H_
24
25 #include <sys/types.h>
26 #include <stdlib.h>
27 #include <stddef.h>
28 #include <sys/time.h>
29 #include <arpa/inet.h>
30 #include <string.h>
31
32 #include "enum.h"
33
34 /**
35 * strongSwan program return codes
36 */
37 #define SS_RC_LIBSTRONGSWAN_INTEGRITY 64
38 #define SS_RC_DAEMON_INTEGRITY 65
39 #define SS_RC_INITIALIZATION_FAILED 66
40
41 #define SS_RC_FIRST SS_RC_LIBSTRONGSWAN_INTEGRITY
42 #define SS_RC_LAST SS_RC_INITIALIZATION_FAILED
43
44 /**
45 * Number of bits in a byte
46 */
47 #define BITS_PER_BYTE 8
48
49 /**
50 * Default length for various auxiliary text buffers
51 */
52 #define BUF_LEN 512
53
54 /**
55 * Macro compares two strings for equality
56 */
57 #define streq(x,y) (strcmp(x, y) == 0)
58
59 /**
60 * Macro compares two strings for equality, length limited
61 */
62 #define strneq(x,y,len) (strncmp(x, y, len) == 0)
63
64 /**
65 * Macro compares two strings for equality ignoring case
66 */
67 #define strcaseeq(x,y) (strcasecmp(x, y) == 0)
68
69 /**
70 * Macro compares two strings for equality ignoring case, length limited
71 */
72 #define strncaseeq(x,y,len) (strncasecmp(x, y, len) == 0)
73
74 /**
75 * NULL-safe strdup variant
76 */
77 #define strdupnull(x) ({ char *_x = x; _x ? strdup(_x) : NULL; })
78
79 /**
80 * Macro compares two binary blobs for equality
81 */
82 #define memeq(x,y,len) (memcmp(x, y, len) == 0)
83
84 /**
85 * Macro gives back larger of two values.
86 */
87 #define max(x,y) ({ \
88 typeof(x) _x = (x); \
89 typeof(y) _y = (y); \
90 _x > _y ? _x : _y; })
91
92
93 /**
94 * Macro gives back smaller of two values.
95 */
96 #define min(x,y) ({ \
97 typeof(x) _x = (x); \
98 typeof(y) _y = (y); \
99 _x < _y ? _x : _y; })
100
101 /**
102 * Call destructor of an object, if object != NULL
103 */
104 #define DESTROY_IF(obj) if (obj) (obj)->destroy(obj)
105
106 /**
107 * Call offset destructor of an object, if object != NULL
108 */
109 #define DESTROY_OFFSET_IF(obj, offset) if (obj) obj->destroy_offset(obj, offset);
110
111 /**
112 * Call function destructor of an object, if object != NULL
113 */
114 #define DESTROY_FUNCTION_IF(obj, fn) if (obj) obj->destroy_function(obj, fn);
115
116 /**
117 * Debug macro to follow control flow
118 */
119 #define POS printf("%s, line %d\n", __FILE__, __LINE__)
120
121 /**
122 * Object allocation/initialization macro, using designated initializer.
123 */
124 #define INIT(this, ...) ({ (this) = malloc(sizeof(*(this))); \
125 *(this) = (typeof(*(this))){ __VA_ARGS__ }; \
126 (this); })
127
128 /**
129 * Method declaration/definition macro, providing private and public interface.
130 *
131 * Defines a method name with this as first parameter and a return value ret,
132 * and an alias for this method with a _ prefix, having the this argument
133 * safely casted to the public interface iface.
134 * _name is provided a function pointer, but will get optimized out by GCC.
135 */
136 #define METHOD(iface, name, ret, this, ...) \
137 static ret name(union {iface *_public; this;} \
138 __attribute__((transparent_union)), ##__VA_ARGS__); \
139 static const typeof(name) *_##name = (const typeof(name)*)name; \
140 static ret name(this, ##__VA_ARGS__)
141
142 /**
143 * Same as METHOD(), but is defined for two public interfaces.
144 */
145 #define METHOD2(iface1, iface2, name, ret, this, ...) \
146 static ret name(union {iface1 *_public1; iface2 *_public2; this;} \
147 __attribute__((transparent_union)), ##__VA_ARGS__); \
148 static const typeof(name) *_##name = (const typeof(name)*)name; \
149 static ret name(this, ##__VA_ARGS__)
150
151 /**
152 * Architecture independent bitfield definition helpers (at least with GCC).
153 *
154 * Defines a bitfield with a type t and a fixed size of bitfield members, e.g.:
155 * BITFIELD2(u_int8_t,
156 * low: 4,
157 * high: 4,
158 * ) flags;
159 * The member defined first placed at bit 0.
160 */
161 #if BYTE_ORDER == LITTLE_ENDIAN
162 #define BITFIELD2(t, a, b,...) struct { t a; t b; __VA_ARGS__}
163 #define BITFIELD3(t, a, b, c,...) struct { t a; t b; t c; __VA_ARGS__}
164 #define BITFIELD4(t, a, b, c, d,...) struct { t a; t b; t c; t d; __VA_ARGS__}
165 #define BITFIELD5(t, a, b, c, d, e,...) struct { t a; t b; t c; t d; t e; __VA_ARGS__}
166 #elif BYTE_ORDER == BIG_ENDIAN
167 #define BITFIELD2(t, a, b,...) struct { t b; t a; __VA_ARGS__}
168 #define BITFIELD3(t, a, b, c,...) struct { t c; t b; t a; __VA_ARGS__}
169 #define BITFIELD4(t, a, b, c, d,...) struct { t d; t c; t b; t a; __VA_ARGS__}
170 #define BITFIELD5(t, a, b, c, d, e,...) struct { t e; t d; t c; t b; t a; __VA_ARGS__}
171 #endif
172
173 /**
174 * Macro to allocate a sized type.
175 */
176 #define malloc_thing(thing) ((thing*)malloc(sizeof(thing)))
177
178 /**
179 * Get the number of elements in an array
180 */
181 #define countof(array) (sizeof(array)/sizeof(array[0]))
182
183 /**
184 * Ignore result of functions tagged with warn_unused_result attributes
185 */
186 #define ignore_result(call) { if(call){}; }
187
188 /**
189 * Assign a function as a class method
190 */
191 #define ASSIGN(method, function) (method = (typeof(method))function)
192
193 /**
194 * time_t not defined
195 */
196 #define UNDEFINED_TIME 0
197
198 /**
199 * Maximum time since epoch causing wrap-around on Jan 19 03:14:07 UTC 2038
200 */
201 #define TIME_32_BIT_SIGNED_MAX 0x7fffffff
202
203 /**
204 * General purpose boolean type.
205 */
206 #ifdef HAVE_STDBOOL_H
207 # include <stdbool.h>
208 #else
209 # ifndef HAVE__BOOL
210 # define _Bool signed char
211 # endif /* HAVE__BOOL */
212 # define bool _Bool
213 # define false 0
214 # define true 1
215 # define __bool_true_false_are_defined 1
216 #endif /* HAVE_STDBOOL_H */
217 #ifndef FALSE
218 # define FALSE false
219 #endif /* FALSE */
220 #ifndef TRUE
221 # define TRUE true
222 #endif /* TRUE */
223
224 /**
225 * define some missing fixed width int types on OpenSolaris.
226 * TODO: since the uintXX_t types are defined by the C99 standard we should
227 * probably use those anyway
228 */
229 #ifdef __sun
230 #include <stdint.h>
231 typedef uint8_t u_int8_t;
232 typedef uint16_t u_int16_t;
233 typedef uint32_t u_int32_t;
234 typedef uint64_t u_int64_t;
235 #endif
236
237 typedef enum status_t status_t;
238
239 /**
240 * Return values of function calls.
241 */
242 enum status_t {
243 /**
244 * Call succeeded.
245 */
246 SUCCESS,
247
248 /**
249 * Call failed.
250 */
251 FAILED,
252
253 /**
254 * Out of resources.
255 */
256 OUT_OF_RES,
257
258 /**
259 * The suggested operation is already done
260 */
261 ALREADY_DONE,
262
263 /**
264 * Not supported.
265 */
266 NOT_SUPPORTED,
267
268 /**
269 * One of the arguments is invalid.
270 */
271 INVALID_ARG,
272
273 /**
274 * Something could not be found.
275 */
276 NOT_FOUND,
277
278 /**
279 * Error while parsing.
280 */
281 PARSE_ERROR,
282
283 /**
284 * Error while verifying.
285 */
286 VERIFY_ERROR,
287
288 /**
289 * Object in invalid state.
290 */
291 INVALID_STATE,
292
293 /**
294 * Destroy object which called method belongs to.
295 */
296 DESTROY_ME,
297
298 /**
299 * Another call to the method is required.
300 */
301 NEED_MORE,
302
303 /**
304 * For tasks only, same as SUCCESS, but also migrate all remaining tasks
305 * in the current queue to the opposite queue (passive->active or active->passive)
306 */
307 MIGRATE,
308 };
309
310 /**
311 * enum_names for type status_t.
312 */
313 extern enum_name_t *status_names;
314
315 /**
316 * deprecated pluto style return value:
317 * error message, NULL for success
318 */
319 typedef const char *err_t;
320
321 /**
322 * Handle struct timeval like an own type.
323 */
324 typedef struct timeval timeval_t;
325
326 /**
327 * Handle struct timespec like an own type.
328 */
329 typedef struct timespec timespec_t;
330
331 /**
332 * Handle struct chunk_t like an own type.
333 */
334 typedef struct sockaddr sockaddr_t;
335
336 /**
337 * Clone a data to a newly allocated buffer
338 */
339 void *clalloc(void *pointer, size_t size);
340
341 /**
342 * Same as memcpy, but XORs src into dst instead of copy
343 */
344 void memxor(u_int8_t dest[], u_int8_t src[], size_t n);
345
346 /**
347 * Safely overwrite n bytes of memory at ptr with zero, non-inlining variant.
348 */
349 void memwipe_noinline(void *ptr, size_t n);
350
351 /**
352 * Safely overwrite n bytes of memory at ptr with zero, inlining variant.
353 */
354 static inline void memwipe_inline(void *ptr, size_t n)
355 {
356 volatile char *c = (volatile char*)ptr;
357 size_t m, i;
358
359 /* byte wise until long aligned */
360 for (i = 0; (uintptr_t)&c[i] % sizeof(long) && i < n; i++)
361 {
362 c[i] = 0;
363 }
364 /* word wise */
365 if (n >= sizeof(long))
366 {
367 for (m = n - sizeof(long); i <= m; i += sizeof(long))
368 {
369 *(volatile long*)&c[i] = 0;
370 }
371 }
372 /* byte wise of the rest */
373 for (; i < n; i++)
374 {
375 c[i] = 0;
376 }
377 }
378
379 /**
380 * Safely overwrite n bytes of memory at ptr with zero, auto-inlining variant.
381 */
382 static inline void memwipe(void *ptr, size_t n)
383 {
384 if (__builtin_constant_p(n))
385 {
386 memwipe_inline(ptr, n);
387 }
388 else
389 {
390 memwipe_noinline(ptr, n);
391 }
392 }
393
394 /**
395 * A variant of strstr with the characteristics of memchr, where haystack is not
396 * a null-terminated string but simply a memory area of length n.
397 */
398 void *memstr(const void *haystack, const char *needle, size_t n);
399
400 /**
401 * Translates the characters in the given string, searching for characters
402 * in 'from' and mapping them to characters in 'to'.
403 * The two characters sets 'from' and 'to' must contain the same number of
404 * characters.
405 */
406 char *translate(char *str, const char *from, const char *to);
407
408 /**
409 * Creates a directory and all required parent directories.
410 *
411 * @param path path to the new directory
412 * @param mode permissions of the new directory/directories
413 * @return TRUE on success
414 */
415 bool mkdir_p(const char *path, mode_t mode);
416
417 #ifndef HAVE_CLOSEFROM
418 /**
419 * Close open file descriptors greater than or equal to lowfd.
420 *
421 * @param lowfd start closing file descriptoros from here
422 */
423 void closefrom(int lowfd);
424 #endif
425
426 /**
427 * Get a timestamp from a monotonic time source.
428 *
429 * While the time()/gettimeofday() functions are affected by leap seconds
430 * and system time changes, this function returns ever increasing monotonic
431 * time stamps.
432 *
433 * @param tv timeval struct receiving monotonic timestamps, or NULL
434 * @return monotonic timestamp in seconds
435 */
436 time_t time_monotonic(timeval_t *tv);
437
438 /**
439 * returns null
440 */
441 void *return_null();
442
443 /**
444 * No-Operation function
445 */
446 void nop();
447
448 /**
449 * returns TRUE
450 */
451 bool return_true();
452
453 /**
454 * returns FALSE
455 */
456 bool return_false();
457
458 /**
459 * returns FAILED
460 */
461 status_t return_failed();
462
463 /**
464 * Write a 16-bit host order value in network order to an unaligned address.
465 *
466 * @param host host order 16-bit value
467 * @param network unaligned address to write network order value to
468 */
469 static inline void htoun16(void *network, u_int16_t host)
470 {
471 char *unaligned = (char*)network;
472
473 host = htons(host);
474 memcpy(unaligned, &host, sizeof(host));
475 }
476
477 /**
478 * Write a 32-bit host order value in network order to an unaligned address.
479 *
480 * @param host host order 32-bit value
481 * @param network unaligned address to write network order value to
482 */
483 static inline void htoun32(void *network, u_int32_t host)
484 {
485 char *unaligned = (char*)network;
486
487 host = htonl(host);
488 memcpy((char*)unaligned, &host, sizeof(host));
489 }
490
491 /**
492 * Read a 16-bit value in network order from an unaligned address to host order.
493 *
494 * @param network unaligned address to read network order value from
495 * @return host order value
496 */
497 static inline u_int16_t untoh16(void *network)
498 {
499 char *unaligned = (char*)network;
500 u_int16_t tmp;
501
502 memcpy(&tmp, unaligned, sizeof(tmp));
503 return ntohs(tmp);
504 }
505
506 /**
507 * Read a 32-bit value in network order from an unaligned address to host order.
508 *
509 * @param network unaligned address to read network order value from
510 * @return host order value
511 */
512 static inline u_int32_t untoh32(void *network)
513 {
514 char *unaligned = (char*)network;
515 u_int32_t tmp;
516
517 memcpy(&tmp, unaligned, sizeof(tmp));
518 return ntohl(tmp);
519 }
520
521 /**
522 * Special type to count references
523 */
524 typedef volatile u_int refcount_t;
525
526
527 #ifdef HAVE_GCC_ATOMIC_OPERATIONS
528
529 #define ref_get(ref) {__sync_fetch_and_add(ref, 1); }
530 #define ref_put(ref) (!__sync_sub_and_fetch(ref, 1))
531
532 #else /* !HAVE_GCC_ATOMIC_OPERATIONS */
533
534 /**
535 * Get a new reference.
536 *
537 * Increments the reference counter atomic.
538 *
539 * @param ref pointer to ref counter
540 */
541 void ref_get(refcount_t *ref);
542
543 /**
544 * Put back a unused reference.
545 *
546 * Decrements the reference counter atomic and
547 * says if more references available.
548 *
549 * @param ref pointer to ref counter
550 * @return TRUE if no more references counted
551 */
552 bool ref_put(refcount_t *ref);
553
554 #endif /* HAVE_GCC_ATOMIC_OPERATIONS */
555
556 /**
557 * printf hook for time_t.
558 *
559 * Arguments are:
560 * time_t* time, bool utc
561 */
562 int time_printf_hook(char *dst, size_t len, printf_hook_spec_t *spec,
563 const void *const *args);
564
565 /**
566 * printf hook for time_t deltas.
567 *
568 * Arguments are:
569 * time_t* begin, time_t* end
570 */
571 int time_delta_printf_hook(char *dst, size_t len, printf_hook_spec_t *spec,
572 const void *const *args);
573
574 /**
575 * printf hook for memory areas.
576 *
577 * Arguments are:
578 * u_char *ptr, int len
579 */
580 int mem_printf_hook(char *dst, size_t len, printf_hook_spec_t *spec,
581 const void *const *args);
582
583 #endif /** UTILS_H_ @}*/