src/basic/util.h

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 #pragma once
   4
   5 /***
   6   This file is part of systemd.
   7
   8   Copyright 2010 Lennart Poettering
   9
  10   systemd is free software; you can redistribute it and/or modify it
  11   under the terms of the GNU Lesser General Public License as published by
  12   the Free Software Foundation; either version 2.1 of the License, or
  13   (at your option) any later version.
  14
  15   systemd is distributed in the hope that it will be useful, but
  16   WITHOUT ANY WARRANTY; without even the implied warranty of
  17   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18   Lesser General Public License for more details.
  19
  20   You should have received a copy of the GNU Lesser General Public License
  21   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  22 ***/
  23
  24 #include <alloca.h>
  25 #include <fcntl.h>
  26 #include <inttypes.h>
  27 #include <limits.h>
  28 #include <locale.h>
  29 #include <stdarg.h>
  30 #include <stdbool.h>
  31 #include <stddef.h>
  32 #include <stdio.h>
  33 #include <stdlib.h>
  34 #include <sys/inotify.h>
  35 #include <sys/socket.h>
  36 #include <sys/stat.h>
  37 #include <sys/statfs.h>
  38 #include <sys/types.h>
  39 #include <time.h>
  40 #include <unistd.h>
  41
  42 #include "formats-util.h"
  43 #include "macro.h"
  44 #include "missing.h"
  45 #include "time-util.h"
  46
  47 /* What is interpreted as whitespace? */
  48 #define WHITESPACE " \t\n\r"
  49 #define NEWLINE    "\n\r"
  50 #define QUOTES     "\"\'"
  51 #define COMMENTS   "#;"
  52 #define GLOB_CHARS "*?["
  53
  54 size_t page_size(void) _pure_;
  55 #define PAGE_ALIGN(l) ALIGN_TO((l), page_size())
  56
  57 #define new(t, n) ((t*) malloc_multiply(sizeof(t), (n)))
  58
  59 #define new0(t, n) ((t*) calloc((n), sizeof(t)))
  60
  61 #define newa(t, n) ((t*) alloca(sizeof(t)*(n)))
  62
  63 #define newa0(t, n) ((t*) alloca0(sizeof(t)*(n)))
  64
  65 #define newdup(t, p, n) ((t*) memdup_multiply(p, sizeof(t), (n)))
  66
  67 #define malloc0(n) (calloc(1, (n)))
  68
  69 static inline void *mfree(void *memory) {
  70         free(memory);
  71         return NULL;
  72 }
  73
  74 static inline const char* yes_no(bool b) {
  75         return b ? "yes" : "no";
  76 }
  77
  78 static inline const char* true_false(bool b) {
  79         return b ? "true" : "false";
  80 }
  81
  82 static inline const char* one_zero(bool b) {
  83         return b ? "1" : "0";
  84 }
  85
  86 bool fstype_is_network(const char *fstype);
  87
  88 noreturn void freeze(void);
  89
  90 void execute_directories(const char* const* directories, usec_t timeout, char *argv[]);
  91
  92 bool plymouth_running(void);
  93
  94 bool display_is_local(const char *display) _pure_;
  95 int socket_from_display(const char *display, char **path);
  96
  97 int glob_exists(const char *path);
  98 int glob_extend(char ***strv, const char *path);
  99
 100 int block_get_whole_disk(dev_t d, dev_t *ret);
 101
 102 #define NULSTR_FOREACH(i, l)                                    \
 103         for ((i) = (l); (i) && *(i); (i) = strchr((i), 0)+1)
 104
 105 #define NULSTR_FOREACH_PAIR(i, j, l)                             \
 106         for ((i) = (l), (j) = strchr((i), 0)+1; (i) && *(i); (i) = strchr((j), 0)+1, (j) = *(i) ? strchr((i), 0)+1 : (i))
 107
 108 int ioprio_class_to_string_alloc(int i, char **s);
 109 int ioprio_class_from_string(const char *s);
 110
 111 const char *sigchld_code_to_string(int i) _const_;
 112 int sigchld_code_from_string(const char *s) _pure_;
 113
 114 int sched_policy_to_string_alloc(int i, char **s);
 115 int sched_policy_from_string(const char *s);
 116
 117 extern int saved_argc;
 118 extern char **saved_argv;
 119
 120 bool kexec_loaded(void);
 121
 122 int prot_from_flags(int flags) _const_;
 123
 124 void* memdup(const void *p, size_t l) _alloc_(2);
 125
 126 int fork_agent(pid_t *pid, const int except[], unsigned n_except, const char *path, ...);
 127
 128 bool in_initrd(void);
 129
 130 static inline void freep(void *p) {
 131         free(*(void**) p);
 132 }
 133
 134 #define _cleanup_free_ _cleanup_(freep)
 135 #define _cleanup_globfree_ _cleanup_(globfree)
 136
 137 _malloc_  _alloc_(1, 2) static inline void *malloc_multiply(size_t a, size_t b) {
 138         if (_unlikely_(b != 0 && a > ((size_t) -1) / b))
 139                 return NULL;
 140
 141         return malloc(a * b);
 142 }
 143
 144 _alloc_(2, 3) static inline void *realloc_multiply(void *p, size_t a, size_t b) {
 145         if (_unlikely_(b != 0 && a > ((size_t) -1) / b))
 146                 return NULL;
 147
 148         return realloc(p, a * b);
 149 }
 150
 151 _alloc_(2, 3) static inline void *memdup_multiply(const void *p, size_t a, size_t b) {
 152         if (_unlikely_(b != 0 && a > ((size_t) -1) / b))
 153                 return NULL;
 154
 155         return memdup(p, a * b);
 156 }
 157
 158 /**
 159  * Check if a string contains any glob patterns.
 160  */
 161 _pure_ static inline bool string_is_glob(const char *p) {
 162         return !!strpbrk(p, GLOB_CHARS);
 163 }
 164
 165 void *xbsearch_r(const void *key, const void *base, size_t nmemb, size_t size,
 166                  int (*compar) (const void *, const void *, void *),
 167                  void *arg);
 168
 169 int on_ac_power(void);
 170
 171 static inline void *mempset(void *s, int c, size_t n) {
 172         memset(s, c, n);
 173         return (uint8_t*)s + n;
 174 }
 175
 176 void* greedy_realloc(void **p, size_t *allocated, size_t need, size_t size);
 177 void* greedy_realloc0(void **p, size_t *allocated, size_t need, size_t size);
 178 #define GREEDY_REALLOC(array, allocated, need)                          \
 179         greedy_realloc((void**) &(array), &(allocated), (need), sizeof((array)[0]))
 180
 181 #define GREEDY_REALLOC0(array, allocated, need)                         \
 182         greedy_realloc0((void**) &(array), &(allocated), (need), sizeof((array)[0]))
 183
 184 static inline void _reset_errno_(int *saved_errno) {
 185         errno = *saved_errno;
 186 }
 187
 188 #define PROTECT_ERRNO _cleanup_(_reset_errno_) __attribute__((unused)) int _saved_errno_ = errno
 189
 190 static inline int negative_errno(void) {
 191         /* This helper should be used to shut up gcc if you know 'errno' is
 192          * negative. Instead of "return -errno;", use "return negative_errno();"
 193          * It will suppress bogus gcc warnings in case it assumes 'errno' might
 194          * be 0 and thus the caller's error-handling might not be triggered. */
 195         assert_return(errno > 0, -EINVAL);
 196         return -errno;
 197 }
 198
 199 static inline unsigned u64log2(uint64_t n) {
 200 #if __SIZEOF_LONG_LONG__ == 8
 201         return (n > 1) ? (unsigned) __builtin_clzll(n) ^ 63U : 0;
 202 #else
 203 #error "Wut?"
 204 #endif
 205 }
 206
 207 static inline unsigned u32ctz(uint32_t n) {
 208 #if __SIZEOF_INT__ == 4
 209         return __builtin_ctz(n);
 210 #else
 211 #error "Wut?"
 212 #endif
 213 }
 214
 215 static inline unsigned log2i(int x) {
 216         assert(x > 0);
 217
 218         return __SIZEOF_INT__ * 8 - __builtin_clz(x) - 1;
 219 }
 220
 221 static inline unsigned log2u(unsigned x) {
 222         assert(x > 0);
 223
 224         return sizeof(unsigned) * 8 - __builtin_clz(x) - 1;
 225 }
 226
 227 static inline unsigned log2u_round_up(unsigned x) {
 228         assert(x > 0);
 229
 230         if (x == 1)
 231                 return 0;
 232
 233         return log2u(x - 1) + 1;
 234 }
 235
 236 #define alloca0(n)                                      \
 237         ({                                              \
 238                 char *_new_;                            \
 239                 size_t _len_ = n;                       \
 240                 _new_ = alloca(_len_);                  \
 241                 (void *) memset(_new_, 0, _len_);       \
 242         })
 243
 244 /* It's not clear what alignment glibc/gcc alloca() guarantee, hence provide a guaranteed safe version */
 245 #define alloca_align(size, align)                                       \
 246         ({                                                              \
 247                 void *_ptr_;                                            \
 248                 size_t _mask_ = (align) - 1;                            \
 249                 _ptr_ = alloca((size) + _mask_);                        \
 250                 (void*)(((uintptr_t)_ptr_ + _mask_) & ~_mask_);         \
 251         })
 252
 253 #define alloca0_align(size, align)                                      \
 254         ({                                                              \
 255                 void *_new_;                                            \
 256                 size_t _size_ = (size);                                 \
 257                 _new_ = alloca_align(_size_, (align));                  \
 258                 (void*)memset(_new_, 0, _size_);                        \
 259         })
 260
 261 bool id128_is_valid(const char *s) _pure_;
 262
 263 /**
 264  * Normal qsort requires base to be nonnull. Here were require
 265  * that only if nmemb > 0.
 266  */
 267 static inline void qsort_safe(void *base, size_t nmemb, size_t size, comparison_fn_t compar) {
 268         if (nmemb <= 1)
 269                 return;
 270
 271         assert(base);
 272         qsort(base, nmemb, size, compar);
 273 }
 274
 275 int container_get_leader(const char *machine, pid_t *pid);
 276
 277 int namespace_open(pid_t pid, int *pidns_fd, int *mntns_fd, int *netns_fd, int *userns_fd, int *root_fd);
 278 int namespace_enter(int pidns_fd, int mntns_fd, int netns_fd, int userns_fd, int root_fd);
 279
 280 #ifndef PERSONALITY_INVALID
 281 /* personality(7) documents that 0xffffffffUL is used for querying the
 282  * current personality, hence let's use that here as error
 283  * indicator. */
 284 #define PERSONALITY_INVALID 0xffffffffLU
 285 #endif
 286
 287 unsigned long personality_from_string(const char *p);
 288 const char *personality_to_string(unsigned long);
 289
 290 uint64_t physical_memory(void);
 291
 292 union file_handle_union {
 293         struct file_handle handle;
 294         char padding[sizeof(struct file_handle) + MAX_HANDLE_SZ];
 295 };
 296 #define FILE_HANDLE_INIT { .handle.handle_bytes = MAX_HANDLE_SZ }
 297
 298 int update_reboot_param_file(const char *param);
 299
 300 #define INOTIFY_EVENT_MAX (sizeof(struct inotify_event) + NAME_MAX + 1)
 301
 302 #define FOREACH_INOTIFY_EVENT(e, buffer, sz) \
 303         for ((e) = &buffer.ev;                                \
 304              (uint8_t*) (e) < (uint8_t*) (buffer.raw) + (sz); \
 305              (e) = (struct inotify_event*) ((uint8_t*) (e) + sizeof(struct inotify_event) + (e)->len))
 306
 307 union inotify_event_buffer {
 308         struct inotify_event ev;
 309         uint8_t raw[INOTIFY_EVENT_MAX];
 310 };
 311
 312 int version(void);
 313
 314 bool fdname_is_valid(const char *s);
 315
 316 bool oom_score_adjust_is_valid(int oa);