utils: ref_get() returns the new value of the reference counter
[strongswan.git] / src / libstrongswan / utils / utils.h
1 /*
2 * Copyright (C) 2008-2012 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_i utils
19 * @{ @ingroup utils
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 * General purpose boolean type.
56 */
57 #ifdef HAVE_STDBOOL_H
58 # include <stdbool.h>
59 #else
60 # ifndef HAVE__BOOL
61 # define _Bool signed char
62 # endif /* HAVE__BOOL */
63 # define bool _Bool
64 # define false 0
65 # define true 1
66 # define __bool_true_false_are_defined 1
67 #endif /* HAVE_STDBOOL_H */
68 #ifndef FALSE
69 # define FALSE false
70 #endif /* FALSE */
71 #ifndef TRUE
72 # define TRUE true
73 #endif /* TRUE */
74
75 /**
76 * Helper function that compares two strings for equality
77 */
78 static inline bool streq(const char *x, const char *y)
79 {
80 return strcmp(x, y) == 0;
81 }
82
83 /**
84 * Macro compares two strings for equality, length limited
85 */
86 #define strneq(x,y,len) (strncmp(x, y, len) == 0)
87
88 /**
89 * Helper function that compares two strings for equality ignoring case
90 */
91 static inline bool strcaseeq(const char *x, const char *y)
92 {
93 return strcasecmp(x, y) == 0;
94 }
95
96 /**
97 * Macro compares two strings for equality ignoring case, length limited
98 */
99 #define strncaseeq(x,y,len) (strncasecmp(x, y, len) == 0)
100
101 /**
102 * NULL-safe strdup variant
103 */
104 static inline char *strdupnull(const char *s)
105 {
106 return s ? strdup(s) : NULL;
107 }
108
109 /**
110 * Macro compares two binary blobs for equality
111 */
112 #define memeq(x,y,len) (memcmp(x, y, len) == 0)
113
114 /**
115 * Macro gives back larger of two values.
116 */
117 #define max(x,y) ({ \
118 typeof(x) _x = (x); \
119 typeof(y) _y = (y); \
120 _x > _y ? _x : _y; })
121
122
123 /**
124 * Macro gives back smaller of two values.
125 */
126 #define min(x,y) ({ \
127 typeof(x) _x = (x); \
128 typeof(y) _y = (y); \
129 _x < _y ? _x : _y; })
130
131 /**
132 * Call destructor of an object, if object != NULL
133 */
134 #define DESTROY_IF(obj) if (obj) (obj)->destroy(obj)
135
136 /**
137 * Call offset destructor of an object, if object != NULL
138 */
139 #define DESTROY_OFFSET_IF(obj, offset) if (obj) obj->destroy_offset(obj, offset);
140
141 /**
142 * Call function destructor of an object, if object != NULL
143 */
144 #define DESTROY_FUNCTION_IF(obj, fn) if (obj) obj->destroy_function(obj, fn);
145
146 /**
147 * Debug macro to follow control flow
148 */
149 #define POS printf("%s, line %d\n", __FILE__, __LINE__)
150
151 /**
152 * Object allocation/initialization macro, using designated initializer.
153 */
154 #define INIT(this, ...) { (this) = malloc(sizeof(*(this))); \
155 *(this) = (typeof(*(this))){ __VA_ARGS__ }; }
156
157 /**
158 * Method declaration/definition macro, providing private and public interface.
159 *
160 * Defines a method name with this as first parameter and a return value ret,
161 * and an alias for this method with a _ prefix, having the this argument
162 * safely casted to the public interface iface.
163 * _name is provided a function pointer, but will get optimized out by GCC.
164 */
165 #define METHOD(iface, name, ret, this, ...) \
166 static ret name(union {iface *_public; this;} \
167 __attribute__((transparent_union)), ##__VA_ARGS__); \
168 static typeof(name) *_##name = (typeof(name)*)name; \
169 static ret name(this, ##__VA_ARGS__)
170
171 /**
172 * Same as METHOD(), but is defined for two public interfaces.
173 */
174 #define METHOD2(iface1, iface2, name, ret, this, ...) \
175 static ret name(union {iface1 *_public1; iface2 *_public2; this;} \
176 __attribute__((transparent_union)), ##__VA_ARGS__); \
177 static typeof(name) *_##name = (typeof(name)*)name; \
178 static ret name(this, ##__VA_ARGS__)
179
180 /**
181 * Architecture independent bitfield definition helpers (at least with GCC).
182 *
183 * Defines a bitfield with a type t and a fixed size of bitfield members, e.g.:
184 * BITFIELD2(u_int8_t,
185 * low: 4,
186 * high: 4,
187 * ) flags;
188 * The member defined first placed at bit 0.
189 */
190 #if BYTE_ORDER == LITTLE_ENDIAN
191 #define BITFIELD2(t, a, b,...) struct { t a; t b; __VA_ARGS__}
192 #define BITFIELD3(t, a, b, c,...) struct { t a; t b; t c; __VA_ARGS__}
193 #define BITFIELD4(t, a, b, c, d,...) struct { t a; t b; t c; t d; __VA_ARGS__}
194 #define BITFIELD5(t, a, b, c, d, e,...) struct { t a; t b; t c; t d; t e; __VA_ARGS__}
195 #elif BYTE_ORDER == BIG_ENDIAN
196 #define BITFIELD2(t, a, b,...) struct { t b; t a; __VA_ARGS__}
197 #define BITFIELD3(t, a, b, c,...) struct { t c; t b; t a; __VA_ARGS__}
198 #define BITFIELD4(t, a, b, c, d,...) struct { t d; t c; t b; t a; __VA_ARGS__}
199 #define BITFIELD5(t, a, b, c, d, e,...) struct { t e; t d; t c; t b; t a; __VA_ARGS__}
200 #endif
201
202 /**
203 * Macro to allocate a sized type.
204 */
205 #define malloc_thing(thing) ((thing*)malloc(sizeof(thing)))
206
207 /**
208 * Get the number of elements in an array
209 */
210 #define countof(array) (sizeof(array)/sizeof(array[0]))
211
212 /**
213 * Ignore result of functions tagged with warn_unused_result attributes
214 */
215 #define ignore_result(call) { if(call){}; }
216
217 /**
218 * Assign a function as a class method
219 */
220 #define ASSIGN(method, function) (method = (typeof(method))function)
221
222 /**
223 * time_t not defined
224 */
225 #define UNDEFINED_TIME 0
226
227 /**
228 * Maximum time since epoch causing wrap-around on Jan 19 03:14:07 UTC 2038
229 */
230 #define TIME_32_BIT_SIGNED_MAX 0x7fffffff
231
232 /**
233 * define some missing fixed width int types on OpenSolaris.
234 * TODO: since the uintXX_t types are defined by the C99 standard we should
235 * probably use those anyway
236 */
237 #ifdef __sun
238 #include <stdint.h>
239 typedef uint8_t u_int8_t;
240 typedef uint16_t u_int16_t;
241 typedef uint32_t u_int32_t;
242 typedef uint64_t u_int64_t;
243 #endif
244
245 typedef enum status_t status_t;
246
247 /**
248 * Return values of function calls.
249 */
250 enum status_t {
251 /**
252 * Call succeeded.
253 */
254 SUCCESS,
255
256 /**
257 * Call failed.
258 */
259 FAILED,
260
261 /**
262 * Out of resources.
263 */
264 OUT_OF_RES,
265
266 /**
267 * The suggested operation is already done
268 */
269 ALREADY_DONE,
270
271 /**
272 * Not supported.
273 */
274 NOT_SUPPORTED,
275
276 /**
277 * One of the arguments is invalid.
278 */
279 INVALID_ARG,
280
281 /**
282 * Something could not be found.
283 */
284 NOT_FOUND,
285
286 /**
287 * Error while parsing.
288 */
289 PARSE_ERROR,
290
291 /**
292 * Error while verifying.
293 */
294 VERIFY_ERROR,
295
296 /**
297 * Object in invalid state.
298 */
299 INVALID_STATE,
300
301 /**
302 * Destroy object which called method belongs to.
303 */
304 DESTROY_ME,
305
306 /**
307 * Another call to the method is required.
308 */
309 NEED_MORE,
310 };
311
312 /**
313 * enum_names for type status_t.
314 */
315 extern enum_name_t *status_names;
316
317 typedef enum tty_escape_t tty_escape_t;
318
319 /**
320 * Excape codes for tty colors
321 */
322 enum tty_escape_t {
323 /** text properties */
324 TTY_RESET,
325 TTY_BOLD,
326 TTY_UNDERLINE,
327 TTY_BLINKING,
328
329 /** foreground colors */
330 TTY_FG_BLACK,
331 TTY_FG_RED,
332 TTY_FG_GREEN,
333 TTY_FG_YELLOW,
334 TTY_FG_BLUE,
335 TTY_FG_MAGENTA,
336 TTY_FG_CYAN,
337 TTY_FG_WHITE,
338 TTY_FG_DEF,
339
340 /** background colors */
341 TTY_BG_BLACK,
342 TTY_BG_RED,
343 TTY_BG_GREEN,
344 TTY_BG_YELLOW,
345 TTY_BG_BLUE,
346 TTY_BG_MAGENTA,
347 TTY_BG_CYAN,
348 TTY_BG_WHITE,
349 TTY_BG_DEF,
350 };
351
352 /**
353 * Get the escape string for a given TTY color, empty string on non-tty fd
354 */
355 char* tty_escape_get(int fd, tty_escape_t escape);
356
357 /**
358 * deprecated pluto style return value:
359 * error message, NULL for success
360 */
361 typedef const char *err_t;
362
363 /**
364 * Handle struct timeval like an own type.
365 */
366 typedef struct timeval timeval_t;
367
368 /**
369 * Handle struct timespec like an own type.
370 */
371 typedef struct timespec timespec_t;
372
373 /**
374 * Handle struct chunk_t like an own type.
375 */
376 typedef struct sockaddr sockaddr_t;
377
378 /**
379 * Same as memcpy, but XORs src into dst instead of copy
380 */
381 void memxor(u_int8_t dest[], u_int8_t src[], size_t n);
382
383 /**
384 * Safely overwrite n bytes of memory at ptr with zero, non-inlining variant.
385 */
386 void memwipe_noinline(void *ptr, size_t n);
387
388 /**
389 * Safely overwrite n bytes of memory at ptr with zero, inlining variant.
390 */
391 static inline void memwipe_inline(void *ptr, size_t n)
392 {
393 volatile char *c = (volatile char*)ptr;
394 size_t m, i;
395
396 /* byte wise until long aligned */
397 for (i = 0; (uintptr_t)&c[i] % sizeof(long) && i < n; i++)
398 {
399 c[i] = 0;
400 }
401 /* word wise */
402 if (n >= sizeof(long))
403 {
404 for (m = n - sizeof(long); i <= m; i += sizeof(long))
405 {
406 *(volatile long*)&c[i] = 0;
407 }
408 }
409 /* byte wise of the rest */
410 for (; i < n; i++)
411 {
412 c[i] = 0;
413 }
414 }
415
416 /**
417 * Safely overwrite n bytes of memory at ptr with zero, auto-inlining variant.
418 */
419 static inline void memwipe(void *ptr, size_t n)
420 {
421 if (!ptr)
422 {
423 return;
424 }
425 if (__builtin_constant_p(n))
426 {
427 memwipe_inline(ptr, n);
428 }
429 else
430 {
431 memwipe_noinline(ptr, n);
432 }
433 }
434
435 /**
436 * A variant of strstr with the characteristics of memchr, where haystack is not
437 * a null-terminated string but simply a memory area of length n.
438 */
439 void *memstr(const void *haystack, const char *needle, size_t n);
440
441 /**
442 * Translates the characters in the given string, searching for characters
443 * in 'from' and mapping them to characters in 'to'.
444 * The two characters sets 'from' and 'to' must contain the same number of
445 * characters.
446 */
447 char *translate(char *str, const char *from, const char *to);
448
449 /**
450 * Creates a directory and all required parent directories.
451 *
452 * @param path path to the new directory
453 * @param mode permissions of the new directory/directories
454 * @return TRUE on success
455 */
456 bool mkdir_p(const char *path, mode_t mode);
457
458 /**
459 * Thread-safe wrapper around strerror and strerror_r.
460 *
461 * This is required because the first is not thread-safe (on some platforms)
462 * and the second uses two different signatures (POSIX/GNU) and is impractical
463 * to use anyway.
464 *
465 * @param errnum error code (i.e. errno)
466 * @return error message
467 */
468 const char *safe_strerror(int errnum);
469
470 /**
471 * Replace usages of strerror(3) with thread-safe variant.
472 */
473 #define strerror(errnum) safe_strerror(errnum)
474
475 #ifndef HAVE_CLOSEFROM
476 /**
477 * Close open file descriptors greater than or equal to lowfd.
478 *
479 * @param lowfd start closing file descriptoros from here
480 */
481 void closefrom(int lowfd);
482 #endif
483
484 /**
485 * Get a timestamp from a monotonic time source.
486 *
487 * While the time()/gettimeofday() functions are affected by leap seconds
488 * and system time changes, this function returns ever increasing monotonic
489 * time stamps.
490 *
491 * @param tv timeval struct receiving monotonic timestamps, or NULL
492 * @return monotonic timestamp in seconds
493 */
494 time_t time_monotonic(timeval_t *tv);
495
496 /**
497 * Add the given number of milliseconds to the given timeval struct
498 *
499 * @param tv timeval struct to modify
500 * @param ms number of milliseconds
501 */
502 static inline void timeval_add_ms(timeval_t *tv, u_int ms)
503 {
504 tv->tv_usec += ms * 1000;
505 while (tv->tv_usec >= 1000000 /* 1s */)
506 {
507 tv->tv_usec -= 1000000;
508 tv->tv_sec++;
509 }
510 }
511
512 /**
513 * returns null
514 */
515 void *return_null();
516
517 /**
518 * No-Operation function
519 */
520 void nop();
521
522 /**
523 * returns TRUE
524 */
525 bool return_true();
526
527 /**
528 * returns FALSE
529 */
530 bool return_false();
531
532 /**
533 * returns FAILED
534 */
535 status_t return_failed();
536
537 /**
538 * returns SUCCESS
539 */
540 status_t return_success();
541
542 /**
543 * Write a 16-bit host order value in network order to an unaligned address.
544 *
545 * @param host host order 16-bit value
546 * @param network unaligned address to write network order value to
547 */
548 static inline void htoun16(void *network, u_int16_t host)
549 {
550 char *unaligned = (char*)network;
551
552 host = htons(host);
553 memcpy(unaligned, &host, sizeof(host));
554 }
555
556 /**
557 * Write a 32-bit host order value in network order to an unaligned address.
558 *
559 * @param host host order 32-bit value
560 * @param network unaligned address to write network order value to
561 */
562 static inline void htoun32(void *network, u_int32_t host)
563 {
564 char *unaligned = (char*)network;
565
566 host = htonl(host);
567 memcpy((char*)unaligned, &host, sizeof(host));
568 }
569
570 /**
571 * Write a 64-bit host order value in network order to an unaligned address.
572 *
573 * @param host host order 64-bit value
574 * @param network unaligned address to write network order value to
575 */
576 static inline void htoun64(void *network, u_int64_t host)
577 {
578 char *unaligned = (char*)network;
579
580 #ifdef be64toh
581 host = htobe64(host);
582 memcpy((char*)unaligned, &host, sizeof(host));
583 #else
584 u_int32_t high_part, low_part;
585
586 high_part = host >> 32;
587 high_part = htonl(high_part);
588 low_part = host & 0xFFFFFFFFLL;
589 low_part = htonl(low_part);
590
591 memcpy(unaligned, &high_part, sizeof(high_part));
592 unaligned += sizeof(high_part);
593 memcpy(unaligned, &low_part, sizeof(low_part));
594 #endif
595 }
596
597 /**
598 * Read a 16-bit value in network order from an unaligned address to host order.
599 *
600 * @param network unaligned address to read network order value from
601 * @return host order value
602 */
603 static inline u_int16_t untoh16(void *network)
604 {
605 char *unaligned = (char*)network;
606 u_int16_t tmp;
607
608 memcpy(&tmp, unaligned, sizeof(tmp));
609 return ntohs(tmp);
610 }
611
612 /**
613 * Read a 32-bit value in network order from an unaligned address to host order.
614 *
615 * @param network unaligned address to read network order value from
616 * @return host order value
617 */
618 static inline u_int32_t untoh32(void *network)
619 {
620 char *unaligned = (char*)network;
621 u_int32_t tmp;
622
623 memcpy(&tmp, unaligned, sizeof(tmp));
624 return ntohl(tmp);
625 }
626
627 /**
628 * Read a 64-bit value in network order from an unaligned address to host order.
629 *
630 * @param network unaligned address to read network order value from
631 * @return host order value
632 */
633 static inline u_int64_t untoh64(void *network)
634 {
635 char *unaligned = (char*)network;
636
637 #ifdef be64toh
638 u_int64_t tmp;
639
640 memcpy(&tmp, unaligned, sizeof(tmp));
641 return be64toh(tmp);
642 #else
643 u_int32_t high_part, low_part;
644
645 memcpy(&high_part, unaligned, sizeof(high_part));
646 unaligned += sizeof(high_part);
647 memcpy(&low_part, unaligned, sizeof(low_part));
648
649 high_part = ntohl(high_part);
650 low_part = ntohl(low_part);
651
652 return (((u_int64_t)high_part) << 32) + low_part;
653 #endif
654 }
655
656 /**
657 * Special type to count references
658 */
659 typedef volatile u_int refcount_t;
660
661
662 #ifdef HAVE_GCC_ATOMIC_OPERATIONS
663
664 #define ref_get(ref) __sync_add_and_fetch(ref, 1)
665 #define ref_put(ref) (!__sync_sub_and_fetch(ref, 1))
666
667 #define cas_bool(ptr, oldval, newval) \
668 (__sync_bool_compare_and_swap(ptr, oldval, newval))
669 #define cas_ptr(ptr, oldval, newval) \
670 (__sync_bool_compare_and_swap(ptr, oldval, newval))
671
672 #else /* !HAVE_GCC_ATOMIC_OPERATIONS */
673
674 /**
675 * Get a new reference.
676 *
677 * Increments the reference counter atomic.
678 *
679 * @param ref pointer to ref counter
680 * @return new value of ref
681 */
682 refcount_t ref_get(refcount_t *ref);
683
684 /**
685 * Put back a unused reference.
686 *
687 * Decrements the reference counter atomic and
688 * says if more references available.
689 *
690 * @param ref pointer to ref counter
691 * @return TRUE if no more references counted
692 */
693 bool ref_put(refcount_t *ref);
694
695 /**
696 * Atomically replace value of ptr with newval if it currently equals oldval.
697 *
698 * @param ptr pointer to variable
699 * @param oldval old value of the variable
700 * @param newval new value set if possible
701 * @return TRUE if value equaled oldval and newval was written
702 */
703 bool cas_bool(bool *ptr, bool oldval, bool newval);
704
705 /**
706 * Atomically replace value of ptr with newval if it currently equals oldval.
707 *
708 * @param ptr pointer to variable
709 * @param oldval old value of the variable
710 * @param newval new value set if possible
711 * @return TRUE if value equaled oldval and newval was written
712 */
713 bool cas_ptr(void **ptr, void *oldval, void *newval);
714
715 #endif /* HAVE_GCC_ATOMIC_OPERATIONS */
716
717 /**
718 * printf hook for time_t.
719 *
720 * Arguments are:
721 * time_t* time, bool utc
722 */
723 int time_printf_hook(printf_hook_data_t *data, printf_hook_spec_t *spec,
724 const void *const *args);
725
726 /**
727 * printf hook for time_t deltas.
728 *
729 * Arguments are:
730 * time_t* begin, time_t* end
731 */
732 int time_delta_printf_hook(printf_hook_data_t *data, printf_hook_spec_t *spec,
733 const void *const *args);
734
735 /**
736 * printf hook for memory areas.
737 *
738 * Arguments are:
739 * u_char *ptr, u_int len
740 */
741 int mem_printf_hook(printf_hook_data_t *data, printf_hook_spec_t *spec,
742 const void *const *args);
743
744 #endif /** UTILS_H_ @}*/