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 block_get_whole_disk(dev_t d, dev_t *ret);
  98
  99 #define NULSTR_FOREACH(i, l)                                    \
 100         for ((i) = (l); (i) && *(i); (i) = strchr((i), 0)+1)
 101
 102 #define NULSTR_FOREACH_PAIR(i, j, l)                             \
 103         for ((i) = (l), (j) = strchr((i), 0)+1; (i) && *(i); (i) = strchr((j), 0)+1, (j) = *(i) ? strchr((i), 0)+1 : (i))
 104
 105 int ioprio_class_to_string_alloc(int i, char **s);
 106 int ioprio_class_from_string(const char *s);
 107
 108 const char *sigchld_code_to_string(int i) _const_;
 109 int sigchld_code_from_string(const char *s) _pure_;
 110
 111 int sched_policy_to_string_alloc(int i, char **s);
 112 int sched_policy_from_string(const char *s);
 113
 114 extern int saved_argc;
 115 extern char **saved_argv;
 116
 117 bool kexec_loaded(void);
 118
 119 int prot_from_flags(int flags) _const_;
 120
 121 void* memdup(const void *p, size_t l) _alloc_(2);
 122
 123 int fork_agent(pid_t *pid, const int except[], unsigned n_except, const char *path, ...);
 124
 125 bool in_initrd(void);
 126
 127 static inline void freep(void *p) {
 128         free(*(void**) p);
 129 }
 130
 131 #define _cleanup_free_ _cleanup_(freep)
 132
 133 _malloc_  _alloc_(1, 2) static inline void *malloc_multiply(size_t a, size_t b) {
 134         if (_unlikely_(b != 0 && a > ((size_t) -1) / b))
 135                 return NULL;
 136
 137         return malloc(a * b);
 138 }
 139
 140 _alloc_(2, 3) static inline void *realloc_multiply(void *p, size_t a, size_t b) {
 141         if (_unlikely_(b != 0 && a > ((size_t) -1) / b))
 142                 return NULL;
 143
 144         return realloc(p, a * b);
 145 }
 146
 147 _alloc_(2, 3) static inline void *memdup_multiply(const void *p, size_t a, size_t b) {
 148         if (_unlikely_(b != 0 && a > ((size_t) -1) / b))
 149                 return NULL;
 150
 151         return memdup(p, a * b);
 152 }
 153
 154 void *xbsearch_r(const void *key, const void *base, size_t nmemb, size_t size,
 155                  int (*compar) (const void *, const void *, void *),
 156                  void *arg);
 157
 158 int on_ac_power(void);
 159
 160 static inline void *mempset(void *s, int c, size_t n) {
 161         memset(s, c, n);
 162         return (uint8_t*)s + n;
 163 }
 164
 165 #define memzero(x,l) (memset((x), 0, (l)))
 166 #define zero(x) (memzero(&(x), sizeof(x)))
 167
 168 void* greedy_realloc(void **p, size_t *allocated, size_t need, size_t size);
 169 void* greedy_realloc0(void **p, size_t *allocated, size_t need, size_t size);
 170 #define GREEDY_REALLOC(array, allocated, need)                          \
 171         greedy_realloc((void**) &(array), &(allocated), (need), sizeof((array)[0]))
 172
 173 #define GREEDY_REALLOC0(array, allocated, need)                         \
 174         greedy_realloc0((void**) &(array), &(allocated), (need), sizeof((array)[0]))
 175
 176 static inline void _reset_errno_(int *saved_errno) {
 177         errno = *saved_errno;
 178 }
 179
 180 #define PROTECT_ERRNO _cleanup_(_reset_errno_) __attribute__((unused)) int _saved_errno_ = errno
 181
 182 static inline int negative_errno(void) {
 183         /* This helper should be used to shut up gcc if you know 'errno' is
 184          * negative. Instead of "return -errno;", use "return negative_errno();"
 185          * It will suppress bogus gcc warnings in case it assumes 'errno' might
 186          * be 0 and thus the caller's error-handling might not be triggered. */
 187         assert_return(errno > 0, -EINVAL);
 188         return -errno;
 189 }
 190
 191 static inline unsigned u64log2(uint64_t n) {
 192 #if __SIZEOF_LONG_LONG__ == 8
 193         return (n > 1) ? (unsigned) __builtin_clzll(n) ^ 63U : 0;
 194 #else
 195 #error "Wut?"
 196 #endif
 197 }
 198
 199 static inline unsigned u32ctz(uint32_t n) {
 200 #if __SIZEOF_INT__ == 4
 201         return __builtin_ctz(n);
 202 #else
 203 #error "Wut?"
 204 #endif
 205 }
 206
 207 static inline unsigned log2i(int x) {
 208         assert(x > 0);
 209
 210         return __SIZEOF_INT__ * 8 - __builtin_clz(x) - 1;
 211 }
 212
 213 static inline unsigned log2u(unsigned x) {
 214         assert(x > 0);
 215
 216         return sizeof(unsigned) * 8 - __builtin_clz(x) - 1;
 217 }
 218
 219 static inline unsigned log2u_round_up(unsigned x) {
 220         assert(x > 0);
 221
 222         if (x == 1)
 223                 return 0;
 224
 225         return log2u(x - 1) + 1;
 226 }
 227
 228 #define alloca0(n)                                      \
 229         ({                                              \
 230                 char *_new_;                            \
 231                 size_t _len_ = n;                       \
 232                 _new_ = alloca(_len_);                  \
 233                 (void *) memset(_new_, 0, _len_);       \
 234         })
 235
 236 /* It's not clear what alignment glibc/gcc alloca() guarantee, hence provide a guaranteed safe version */
 237 #define alloca_align(size, align)                                       \
 238         ({                                                              \
 239                 void *_ptr_;                                            \
 240                 size_t _mask_ = (align) - 1;                            \
 241                 _ptr_ = alloca((size) + _mask_);                        \
 242                 (void*)(((uintptr_t)_ptr_ + _mask_) & ~_mask_);         \
 243         })
 244
 245 #define alloca0_align(size, align)                                      \
 246         ({                                                              \
 247                 void *_new_;                                            \
 248                 size_t _size_ = (size);                                 \
 249                 _new_ = alloca_align(_size_, (align));                  \
 250                 (void*)memset(_new_, 0, _size_);                        \
 251         })
 252
 253 bool id128_is_valid(const char *s) _pure_;
 254
 255 /**
 256  * Normal qsort requires base to be nonnull. Here were require
 257  * that only if nmemb > 0.
 258  */
 259 static inline void qsort_safe(void *base, size_t nmemb, size_t size, comparison_fn_t compar) {
 260         if (nmemb <= 1)
 261                 return;
 262
 263         assert(base);
 264         qsort(base, nmemb, size, compar);
 265 }
 266
 267 int container_get_leader(const char *machine, pid_t *pid);
 268
 269 int namespace_open(pid_t pid, int *pidns_fd, int *mntns_fd, int *netns_fd, int *userns_fd, int *root_fd);
 270 int namespace_enter(int pidns_fd, int mntns_fd, int netns_fd, int userns_fd, int root_fd);
 271
 272 #ifndef PERSONALITY_INVALID
 273 /* personality(7) documents that 0xffffffffUL is used for querying the
 274  * current personality, hence let's use that here as error
 275  * indicator. */
 276 #define PERSONALITY_INVALID 0xffffffffLU
 277 #endif
 278
 279 unsigned long personality_from_string(const char *p);
 280 const char *personality_to_string(unsigned long);
 281
 282 uint64_t physical_memory(void);
 283
 284 union file_handle_union {
 285         struct file_handle handle;
 286         char padding[sizeof(struct file_handle) + MAX_HANDLE_SZ];
 287 };
 288 #define FILE_HANDLE_INIT { .handle.handle_bytes = MAX_HANDLE_SZ }
 289
 290 int update_reboot_param_file(const char *param);
 291
 292 #define INOTIFY_EVENT_MAX (sizeof(struct inotify_event) + NAME_MAX + 1)
 293
 294 #define FOREACH_INOTIFY_EVENT(e, buffer, sz) \
 295         for ((e) = &buffer.ev;                                \
 296              (uint8_t*) (e) < (uint8_t*) (buffer.raw) + (sz); \
 297              (e) = (struct inotify_event*) ((uint8_t*) (e) + sizeof(struct inotify_event) + (e)->len))
 298
 299 union inotify_event_buffer {
 300         struct inotify_event ev;
 301         uint8_t raw[INOTIFY_EVENT_MAX];
 302 };
 303
 304 int version(void);
 305
 306 bool fdname_is_valid(const char *s);
 307
 308 bool oom_score_adjust_is_valid(int oa);