include/asterisk/utils.h

   1 /*
   2  * Asterisk -- A telephony toolkit for Linux.
   3  *
   4  * Utility functions
   5  *
   6  * Copyright (C) 2004 - 2005, Digium, Inc.
   7  *
   8  * This program is free software, distributed under the terms of
   9  * the GNU General Public License
  10  */
  11
  12 #ifndef _ASTERISK_UTIL_H
  13 #define _ASTERISK_UTIL_H
  14
  15 #include <netinet/in.h>
  16 #include <netdb.h>
  17 #include <pthread.h>
  18 #include <asterisk/lock.h>
  19 #include <limits.h>
  20
  21 /* Note:
  22    It is very important to use only unsigned variables to hold
  23    bit flags, as otherwise you can fall prey to the compiler's
  24    sign-extension antics if you try to use the top two bits in
  25    your variable.
  26
  27    The flag macros below use a set of compiler tricks to verify
  28    that the caller is using an "unsigned int" variable to hold
  29    the flags, and nothing else. If the caller uses any other
  30    type of variable, a warning message similar to this:
  31
  32    warning: comparison of distinct pointer types lacks cast
  33
  34    will be generated.
  35
  36    The "dummy" variable below is used to make these comparisons.
  37
  38    Also note that at -O2 or above, this type-safety checking
  39    does _not_ produce any additional object code at all.
  40 */
  41
  42 extern unsigned int __unsigned_int_flags_dummy;
  43
  44 #define ast_test_flag(p,flag)           ({ \
  45                                         typeof ((p)->flags) __p = (p)->flags; \
  46                                         typeof (__unsigned_int_flags_dummy) __x = 0; \
  47                                         (void) (&__p == &__x); \
  48                                         ((p)->flags & (flag)); \
  49                                         })
  50
  51 #define ast_set_flag(p,flag)            do { \
  52                                         typeof ((p)->flags) __p = (p)->flags; \
  53                                         typeof (__unsigned_int_flags_dummy) __x = 0; \
  54                                         (void) (&__p == &__x); \
  55                                         ((p)->flags |= (flag)); \
  56                                         } while(0)
  57
  58 #define ast_clear_flag(p,flag)          do { \
  59                                         typeof ((p)->flags) __p = (p)->flags; \
  60                                         typeof (__unsigned_int_flags_dummy) __x = 0; \
  61                                         (void) (&__p == &__x); \
  62                                         ((p)->flags &= ~(flag)); \
  63                                         } while(0)
  64
  65 #define ast_copy_flags(dest,src,flagz)  do { \
  66                                         typeof ((dest)->flags) __d = (dest)->flags; \
  67                                         typeof ((src)->flags) __s = (src)->flags; \
  68                                         typeof (__unsigned_int_flags_dummy) __x = 0; \
  69                                         (void) (&__d == &__x); \
  70                                         (void) (&__s == &__x); \
  71                                         (dest)->flags &= ~(flagz); \
  72                                         (dest)->flags |= ((src)->flags & (flagz)); \
  73                                         } while (0)
  74
  75 #define ast_set2_flag(p,value,flag)     do { \
  76                                         typeof ((p)->flags) __p = (p)->flags; \
  77                                         typeof (__unsigned_int_flags_dummy) __x = 0; \
  78                                         (void) (&__p == &__x); \
  79                                         if (value) \
  80                                                 (p)->flags |= (flag); \
  81                                         else \
  82                                                 (p)->flags &= ~(flag); \
  83                                         } while (0)
  84
  85 /* Non-type checking variations for non-unsigned int flags.  You
  86    should only use non-unsigned int flags where required by
  87    protocol etc and if you know what you're doing :)  */
  88 #define ast_test_flag_nonstd(p,flag)            ({ \
  89                                         ((p)->flags & (flag)); \
  90                                         })
  91
  92 #define ast_set_flag_nonstd(p,flag)             do { \
  93                                         ((p)->flags |= (flag)); \
  94                                         } while(0)
  95
  96 #define ast_clear_flag_nonstd(p,flag)           do { \
  97                                         ((p)->flags &= ~(flag)); \
  98                                         } while(0)
  99
 100 #define ast_copy_flags_nonstd(dest,src,flagz)   do { \
 101                                         (dest)->flags &= ~(flagz); \
 102                                         (dest)->flags |= ((src)->flags & (flagz)); \
 103                                         } while (0)
 104
 105 #define ast_set2_flag_nonstd(p,value,flag)      do { \
 106                                         if (value) \
 107                                                 (p)->flags |= (flag); \
 108                                         else \
 109                                                 (p)->flags &= ~(flag); \
 110                                         } while (0)
 111
 112 #define AST_FLAGS_ALL UINT_MAX
 113
 114 struct ast_flags {
 115         unsigned int flags;
 116 };
 117
 118 static inline int ast_strlen_zero(const char *s)
 119 {
 120         return (*s == '\0');
 121 }
 122
 123 struct ast_hostent {
 124         struct hostent hp;
 125         char buf[1024];
 126 };
 127
 128 extern char *ast_strip(char *buf);
 129 extern struct hostent *ast_gethostbyname(const char *host, struct ast_hostent *hp);
 130 /* ast_md5_hash: Produces MD5 hash based on input string */
 131 extern void ast_md5_hash(char *output, char *input);
 132 extern int ast_base64encode(char *dst, unsigned char *src, int srclen, int max);
 133 extern int ast_base64decode(unsigned char *dst, char *src, int max);
 134
 135 extern int test_for_thread_safety(void);
 136
 137 extern const char *ast_inet_ntoa(char *buf, int bufsiz, struct in_addr ia);
 138 extern int ast_utils_init(void);
 139
 140 /* The realloca lets us ast_restrdupa(), but you can't mix any other ast_strdup calls! */
 141
 142 struct ast_realloca {
 143         char *ptr;
 144         int alloclen;
 145 };
 146
 147 #define ast_restrdupa(ra, s) \
 148         ({ \
 149                 if ((ra)->ptr && strlen(s) + 1 < (ra)->alloclen) { \
 150                         strcpy((ra)->ptr, s); \
 151                 } else { \
 152                         (ra)->ptr = alloca(strlen(s) + 1 - (ra)->alloclen); \
 153                         if ((ra)->ptr) (ra)->alloclen = strlen(s) + 1; \
 154                 } \
 155                 (ra)->ptr; \
 156         })
 157
 158 #ifdef inet_ntoa
 159 #undef inet_ntoa
 160 #endif
 161 #define inet_ntoa __dont__use__inet_ntoa__use__ast_inet_ntoa__instead__
 162
 163 #define AST_STACK_SIZE 128 * 1024
 164
 165 #ifdef __linux__
 166 #define ast_pthread_create pthread_create
 167 #define ast_strcasestr strcasestr
 168 #else
 169 /* Linux threads have a default 2MB stack size. */
 170 #ifndef PTHREAD_ATTR_STACKSIZE
 171 #define PTHREAD_ATTR_STACKSIZE          2097152
 172 #endif /* PTHREAD_ATTR_STACKSIZE */
 173 extern int ast_pthread_create(pthread_t *thread, pthread_attr_t *attr, void *(*start_routine)(void *), void *data);
 174 extern char *ast_strcasestr(const char *, const char *);
 175 #endif /* __linux__ */
 176
 177
 178 #endif