src/basic/util.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 #include <alloca.h>
   5 #include <errno.h>
   6 #include <fcntl.h>
   7 #include <inttypes.h>
   8 #include <limits.h>
   9 #include <locale.h>
  10 #include <stdarg.h>
  11 #include <stdbool.h>
  12 #include <stddef.h>
  13 #include <stdint.h>
  14 #include <stdio.h>
  15 #include <stdlib.h>
  16 #include <string.h>
  17 #include <sys/inotify.h>
  18 #include <sys/socket.h>
  19 #include <sys/stat.h>
  20 #include <sys/statfs.h>
  21 #include <sys/sysmacros.h>
  22 #include <sys/types.h>
  23 #include <time.h>
  24 #include <unistd.h>
  25
  26 #include "format-util.h"
  27 #include "macro.h"
  28 #include "missing.h"
  29 #include "time-util.h"
  30
  31 size_t page_size(void) _pure_;
  32 #define PAGE_ALIGN(l) ALIGN_TO((l), page_size())
  33
  34 static inline const char* yes_no(bool b) {
  35         return b ? "yes" : "no";
  36 }
  37
  38 static inline const char* true_false(bool b) {
  39         return b ? "true" : "false";
  40 }
  41
  42 static inline const char* one_zero(bool b) {
  43         return b ? "1" : "0";
  44 }
  45
  46 static inline const char* enable_disable(bool b) {
  47         return b ? "enable" : "disable";
  48 }
  49
  50 bool plymouth_running(void);
  51
  52 bool display_is_local(const char *display) _pure_;
  53
  54 #define NULSTR_FOREACH(i, l)                                    \
  55         for ((i) = (l); (i) && *(i); (i) = strchr((i), 0)+1)
  56
  57 #define NULSTR_FOREACH_PAIR(i, j, l)                             \
  58         for ((i) = (l), (j) = strchr((i), 0)+1; (i) && *(i); (i) = strchr((j), 0)+1, (j) = *(i) ? strchr((i), 0)+1 : (i))
  59
  60 extern int saved_argc;
  61 extern char **saved_argv;
  62
  63 bool kexec_loaded(void);
  64
  65 int prot_from_flags(int flags) _const_;
  66
  67 bool in_initrd(void);
  68 void in_initrd_force(bool value);
  69
  70 void *xbsearch_r(const void *key, const void *base, size_t nmemb, size_t size,
  71                  __compar_d_fn_t compar, void *arg);
  72
  73 #define typesafe_bsearch_r(k, b, n, func, userdata)                     \
  74         ({                                                              \
  75                 const typeof(b[0]) *_k = k;                             \
  76                 int (*_func_)(const typeof(b[0])*, const typeof(b[0])*, typeof(userdata)) = func; \
  77                 xbsearch_r((const void*) _k, (b), (n), sizeof((b)[0]), (__compar_d_fn_t) _func_, userdata); \
  78         })
  79
  80 /**
  81  * Normal bsearch requires base to be nonnull. Here were require
  82  * that only if nmemb > 0.
  83  */
  84 static inline void* bsearch_safe(const void *key, const void *base,
  85                                  size_t nmemb, size_t size, __compar_fn_t compar) {
  86         if (nmemb <= 0)
  87                 return NULL;
  88
  89         assert(base);
  90         return bsearch(key, base, nmemb, size, compar);
  91 }
  92
  93 #define typesafe_bsearch(k, b, n, func)                                 \
  94         ({                                                              \
  95                 const typeof(b[0]) *_k = k;                             \
  96                 int (*_func_)(const typeof(b[0])*, const typeof(b[0])*) = func; \
  97                 bsearch_safe((const void*) _k, (b), (n), sizeof((b)[0]), (__compar_fn_t) _func_); \
  98         })
  99
 100 /**
 101  * Normal qsort requires base to be nonnull. Here were require
 102  * that only if nmemb > 0.
 103  */
 104 static inline void qsort_safe(void *base, size_t nmemb, size_t size, __compar_fn_t compar) {
 105         if (nmemb <= 1)
 106                 return;
 107
 108         assert(base);
 109         qsort(base, nmemb, size, compar);
 110 }
 111
 112 /* A wrapper around the above, but that adds typesafety: the element size is automatically derived from the type and so
 113  * is the prototype for the comparison function */
 114 #define typesafe_qsort(p, n, func)                                      \
 115         ({                                                              \
 116                 int (*_func_)(const typeof(p[0])*, const typeof(p[0])*) = func; \
 117                 qsort_safe((p), (n), sizeof((p)[0]), (__compar_fn_t) _func_); \
 118         })
 119
 120 static inline void qsort_r_safe(void *base, size_t nmemb, size_t size, __compar_d_fn_t compar, void *userdata) {
 121         if (nmemb <= 1)
 122                 return;
 123
 124         assert(base);
 125         qsort_r(base, nmemb, size, compar, userdata);
 126 }
 127
 128 #define typesafe_qsort_r(p, n, func, userdata)                          \
 129         ({                                                              \
 130                 int (*_func_)(const typeof(p[0])*, const typeof(p[0])*, typeof(userdata)) = func; \
 131                 qsort_r_safe((p), (n), sizeof((p)[0]), (__compar_d_fn_t) _func_, userdata); \
 132         })
 133
 134 /* Normal memcpy requires src to be nonnull. We do nothing if n is 0. */
 135 static inline void memcpy_safe(void *dst, const void *src, size_t n) {
 136         if (n == 0)
 137                 return;
 138         assert(src);
 139         memcpy(dst, src, n);
 140 }
 141
 142 /* Normal memcmp requires s1 and s2 to be nonnull. We do nothing if n is 0. */
 143 static inline int memcmp_safe(const void *s1, const void *s2, size_t n) {
 144         if (n == 0)
 145                 return 0;
 146         assert(s1);
 147         assert(s2);
 148         return memcmp(s1, s2, n);
 149 }
 150
 151 int on_ac_power(void);
 152
 153 #define memzero(x,l)                                            \
 154         ({                                                      \
 155                 size_t _l_ = (l);                               \
 156                 void *_x_ = (x);                                \
 157                 _l_ == 0 ? _x_ : memset(_x_, 0, _l_);           \
 158         })
 159
 160 #define zero(x) (memzero(&(x), sizeof(x)))
 161
 162 bool memeqzero(const void *data, size_t length);
 163
 164 #define eqzero(x) memeqzero(x, sizeof(x))
 165
 166 static inline void *mempset(void *s, int c, size_t n) {
 167         memset(s, c, n);
 168         return (uint8_t*)s + n;
 169 }
 170
 171 static inline void _reset_errno_(int *saved_errno) {
 172         errno = *saved_errno;
 173 }
 174
 175 #define PROTECT_ERRNO                                                   \
 176         _cleanup_(_reset_errno_) __attribute__((__unused__)) int _saved_errno_ = errno
 177
 178 static inline int negative_errno(void) {
 179         /* This helper should be used to shut up gcc if you know 'errno' is
 180          * negative. Instead of "return -errno;", use "return negative_errno();"
 181          * It will suppress bogus gcc warnings in case it assumes 'errno' might
 182          * be 0 and thus the caller's error-handling might not be triggered. */
 183         assert_return(errno > 0, -EINVAL);
 184         return -errno;
 185 }
 186
 187 static inline unsigned u64log2(uint64_t n) {
 188 #if __SIZEOF_LONG_LONG__ == 8
 189         return (n > 1) ? (unsigned) __builtin_clzll(n) ^ 63U : 0;
 190 #else
 191 #error "Wut?"
 192 #endif
 193 }
 194
 195 static inline unsigned u32ctz(uint32_t n) {
 196 #if __SIZEOF_INT__ == 4
 197         return __builtin_ctz(n);
 198 #else
 199 #error "Wut?"
 200 #endif
 201 }
 202
 203 static inline unsigned log2i(int x) {
 204         assert(x > 0);
 205
 206         return __SIZEOF_INT__ * 8 - __builtin_clz(x) - 1;
 207 }
 208
 209 static inline unsigned log2u(unsigned x) {
 210         assert(x > 0);
 211
 212         return sizeof(unsigned) * 8 - __builtin_clz(x) - 1;
 213 }
 214
 215 static inline unsigned log2u_round_up(unsigned x) {
 216         assert(x > 0);
 217
 218         if (x == 1)
 219                 return 0;
 220
 221         return log2u(x - 1) + 1;
 222 }
 223
 224 int container_get_leader(const char *machine, pid_t *pid);
 225
 226 int namespace_open(pid_t pid, int *pidns_fd, int *mntns_fd, int *netns_fd, int *userns_fd, int *root_fd);
 227 int namespace_enter(int pidns_fd, int mntns_fd, int netns_fd, int userns_fd, int root_fd);
 228
 229 uint64_t physical_memory(void);
 230 uint64_t physical_memory_scale(uint64_t v, uint64_t max);
 231
 232 uint64_t system_tasks_max(void);
 233 uint64_t system_tasks_max_scale(uint64_t v, uint64_t max);
 234
 235 int version(void);
 236
 237 int str_verscmp(const char *s1, const char *s2);
 238
 239 void disable_coredumps(void);