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 #define xsprintf(buf, fmt, ...) \
  89         assert_message_se((size_t) snprintf(buf, ELEMENTSOF(buf), fmt, __VA_ARGS__) < ELEMENTSOF(buf), \
  90                           "xsprintf: " #buf "[] must be big enough")
  91
  92 int running_in_chroot(void);
  93
  94 noreturn void freeze(void);
  95
  96 void execute_directories(const char* const* directories, usec_t timeout, char *argv[]);
  97
  98 bool plymouth_running(void);
  99
 100 bool display_is_local(const char *display) _pure_;
 101 int socket_from_display(const char *display, char **path);
 102
 103 int glob_exists(const char *path);
 104 int glob_extend(char ***strv, const char *path);
 105
 106 bool is_main_thread(void);
 107
 108 int block_get_whole_disk(dev_t d, dev_t *ret);
 109
 110 #define NULSTR_FOREACH(i, l)                                    \
 111         for ((i) = (l); (i) && *(i); (i) = strchr((i), 0)+1)
 112
 113 #define NULSTR_FOREACH_PAIR(i, j, l)                             \
 114         for ((i) = (l), (j) = strchr((i), 0)+1; (i) && *(i); (i) = strchr((j), 0)+1, (j) = *(i) ? strchr((i), 0)+1 : (i))
 115
 116 int ioprio_class_to_string_alloc(int i, char **s);
 117 int ioprio_class_from_string(const char *s);
 118
 119 const char *sigchld_code_to_string(int i) _const_;
 120 int sigchld_code_from_string(const char *s) _pure_;
 121
 122 int log_facility_unshifted_to_string_alloc(int i, char **s);
 123 int log_facility_unshifted_from_string(const char *s);
 124 bool log_facility_unshifted_is_valid(int faciliy);
 125
 126 int log_level_to_string_alloc(int i, char **s);
 127 int log_level_from_string(const char *s);
 128 bool log_level_is_valid(int level);
 129
 130 int sched_policy_to_string_alloc(int i, char **s);
 131 int sched_policy_from_string(const char *s);
 132
 133 extern int saved_argc;
 134 extern char **saved_argv;
 135
 136 bool kexec_loaded(void);
 137
 138 int prot_from_flags(int flags) _const_;
 139
 140 void* memdup(const void *p, size_t l) _alloc_(2);
 141
 142 int fork_agent(pid_t *pid, const int except[], unsigned n_except, const char *path, ...);
 143
 144 bool http_url_is_valid(const char *url) _pure_;
 145 bool documentation_url_is_valid(const char *url) _pure_;
 146
 147 bool http_etag_is_valid(const char *etag);
 148
 149 bool in_initrd(void);
 150
 151 static inline void freep(void *p) {
 152         free(*(void**) p);
 153 }
 154
 155 static inline void umaskp(mode_t *u) {
 156         umask(*u);
 157 }
 158
 159 #define _cleanup_free_ _cleanup_(freep)
 160 #define _cleanup_umask_ _cleanup_(umaskp)
 161 #define _cleanup_globfree_ _cleanup_(globfree)
 162
 163 _malloc_  _alloc_(1, 2) static inline void *malloc_multiply(size_t a, size_t b) {
 164         if (_unlikely_(b != 0 && a > ((size_t) -1) / b))
 165                 return NULL;
 166
 167         return malloc(a * b);
 168 }
 169
 170 _alloc_(2, 3) static inline void *realloc_multiply(void *p, size_t a, size_t b) {
 171         if (_unlikely_(b != 0 && a > ((size_t) -1) / b))
 172                 return NULL;
 173
 174         return realloc(p, a * b);
 175 }
 176
 177 _alloc_(2, 3) static inline void *memdup_multiply(const void *p, size_t a, size_t b) {
 178         if (_unlikely_(b != 0 && a > ((size_t) -1) / b))
 179                 return NULL;
 180
 181         return memdup(p, a * b);
 182 }
 183
 184 /**
 185  * Check if a string contains any glob patterns.
 186  */
 187 _pure_ static inline bool string_is_glob(const char *p) {
 188         return !!strpbrk(p, GLOB_CHARS);
 189 }
 190
 191 void *xbsearch_r(const void *key, const void *base, size_t nmemb, size_t size,
 192                  int (*compar) (const void *, const void *, void *),
 193                  void *arg);
 194
 195 #define _(String) gettext (String)
 196 #define N_(String) String
 197 void init_gettext(void);
 198 bool is_locale_utf8(void);
 199
 200 typedef enum DrawSpecialChar {
 201         DRAW_TREE_VERTICAL,
 202         DRAW_TREE_BRANCH,
 203         DRAW_TREE_RIGHT,
 204         DRAW_TREE_SPACE,
 205         DRAW_TRIANGULAR_BULLET,
 206         DRAW_BLACK_CIRCLE,
 207         DRAW_ARROW,
 208         DRAW_DASH,
 209         _DRAW_SPECIAL_CHAR_MAX
 210 } DrawSpecialChar;
 211
 212 const char *draw_special_char(DrawSpecialChar ch);
 213
 214 int on_ac_power(void);
 215
 216 static inline void *mempset(void *s, int c, size_t n) {
 217         memset(s, c, n);
 218         return (uint8_t*)s + n;
 219 }
 220
 221 void* greedy_realloc(void **p, size_t *allocated, size_t need, size_t size);
 222 void* greedy_realloc0(void **p, size_t *allocated, size_t need, size_t size);
 223 #define GREEDY_REALLOC(array, allocated, need)                          \
 224         greedy_realloc((void**) &(array), &(allocated), (need), sizeof((array)[0]))
 225
 226 #define GREEDY_REALLOC0(array, allocated, need)                         \
 227         greedy_realloc0((void**) &(array), &(allocated), (need), sizeof((array)[0]))
 228
 229 static inline void _reset_errno_(int *saved_errno) {
 230         errno = *saved_errno;
 231 }
 232
 233 #define PROTECT_ERRNO _cleanup_(_reset_errno_) __attribute__((unused)) int _saved_errno_ = errno
 234
 235 static inline int negative_errno(void) {
 236         /* This helper should be used to shut up gcc if you know 'errno' is
 237          * negative. Instead of "return -errno;", use "return negative_errno();"
 238          * It will suppress bogus gcc warnings in case it assumes 'errno' might
 239          * be 0 and thus the caller's error-handling might not be triggered. */
 240         assert_return(errno > 0, -EINVAL);
 241         return -errno;
 242 }
 243
 244 struct _umask_struct_ {
 245         mode_t mask;
 246         bool quit;
 247 };
 248
 249 static inline void _reset_umask_(struct _umask_struct_ *s) {
 250         umask(s->mask);
 251 };
 252
 253 #define RUN_WITH_UMASK(mask)                                            \
 254         for (_cleanup_(_reset_umask_) struct _umask_struct_ _saved_umask_ = { umask(mask), false }; \
 255              !_saved_umask_.quit ;                                      \
 256              _saved_umask_.quit = true)
 257
 258 static inline unsigned u64log2(uint64_t n) {
 259 #if __SIZEOF_LONG_LONG__ == 8
 260         return (n > 1) ? (unsigned) __builtin_clzll(n) ^ 63U : 0;
 261 #else
 262 #error "Wut?"
 263 #endif
 264 }
 265
 266 static inline unsigned u32ctz(uint32_t n) {
 267 #if __SIZEOF_INT__ == 4
 268         return __builtin_ctz(n);
 269 #else
 270 #error "Wut?"
 271 #endif
 272 }
 273
 274 static inline unsigned log2i(int x) {
 275         assert(x > 0);
 276
 277         return __SIZEOF_INT__ * 8 - __builtin_clz(x) - 1;
 278 }
 279
 280 static inline unsigned log2u(unsigned x) {
 281         assert(x > 0);
 282
 283         return sizeof(unsigned) * 8 - __builtin_clz(x) - 1;
 284 }
 285
 286 static inline unsigned log2u_round_up(unsigned x) {
 287         assert(x > 0);
 288
 289         if (x == 1)
 290                 return 0;
 291
 292         return log2u(x - 1) + 1;
 293 }
 294
 295 #define DECIMAL_STR_WIDTH(x)                            \
 296         ({                                              \
 297                 typeof(x) _x_ = (x);                    \
 298                 unsigned ans = 1;                       \
 299                 while (_x_ /= 10)                       \
 300                         ans++;                          \
 301                 ans;                                    \
 302         })
 303
 304 #define alloca0(n)                                      \
 305         ({                                              \
 306                 char *_new_;                            \
 307                 size_t _len_ = n;                       \
 308                 _new_ = alloca(_len_);                  \
 309                 (void *) memset(_new_, 0, _len_);       \
 310         })
 311
 312 /* It's not clear what alignment glibc/gcc alloca() guarantee, hence provide a guaranteed safe version */
 313 #define alloca_align(size, align)                                       \
 314         ({                                                              \
 315                 void *_ptr_;                                            \
 316                 size_t _mask_ = (align) - 1;                            \
 317                 _ptr_ = alloca((size) + _mask_);                        \
 318                 (void*)(((uintptr_t)_ptr_ + _mask_) & ~_mask_);         \
 319         })
 320
 321 #define alloca0_align(size, align)                                      \
 322         ({                                                              \
 323                 void *_new_;                                            \
 324                 size_t _size_ = (size);                                 \
 325                 _new_ = alloca_align(_size_, (align));                  \
 326                 (void*)memset(_new_, 0, _size_);                        \
 327         })
 328
 329 bool id128_is_valid(const char *s) _pure_;
 330
 331 int shall_restore_state(void);
 332
 333 /**
 334  * Normal qsort requires base to be nonnull. Here were require
 335  * that only if nmemb > 0.
 336  */
 337 static inline void qsort_safe(void *base, size_t nmemb, size_t size, comparison_fn_t compar) {
 338         if (nmemb <= 1)
 339                 return;
 340
 341         assert(base);
 342         qsort(base, nmemb, size, compar);
 343 }
 344
 345 int proc_cmdline(char **ret);
 346 int parse_proc_cmdline(int (*parse_word)(const char *key, const char *value));
 347 int get_proc_cmdline_key(const char *parameter, char **value);
 348
 349 int container_get_leader(const char *machine, pid_t *pid);
 350
 351 int namespace_open(pid_t pid, int *pidns_fd, int *mntns_fd, int *netns_fd, int *userns_fd, int *root_fd);
 352 int namespace_enter(int pidns_fd, int mntns_fd, int netns_fd, int userns_fd, int root_fd);
 353
 354 #ifndef PERSONALITY_INVALID
 355 /* personality(7) documents that 0xffffffffUL is used for querying the
 356  * current personality, hence let's use that here as error
 357  * indicator. */
 358 #define PERSONALITY_INVALID 0xffffffffLU
 359 #endif
 360
 361 unsigned long personality_from_string(const char *p);
 362 const char *personality_to_string(unsigned long);
 363
 364 uint64_t physical_memory(void);
 365
 366 union file_handle_union {
 367         struct file_handle handle;
 368         char padding[sizeof(struct file_handle) + MAX_HANDLE_SZ];
 369 };
 370 #define FILE_HANDLE_INIT { .handle.handle_bytes = MAX_HANDLE_SZ }
 371
 372 int update_reboot_param_file(const char *param);
 373
 374 #define INOTIFY_EVENT_MAX (sizeof(struct inotify_event) + NAME_MAX + 1)
 375
 376 #define FOREACH_INOTIFY_EVENT(e, buffer, sz) \
 377         for ((e) = &buffer.ev;                                \
 378              (uint8_t*) (e) < (uint8_t*) (buffer.raw) + (sz); \
 379              (e) = (struct inotify_event*) ((uint8_t*) (e) + sizeof(struct inotify_event) + (e)->len))
 380
 381 union inotify_event_buffer {
 382         struct inotify_event ev;
 383         uint8_t raw[INOTIFY_EVENT_MAX];
 384 };
 385
 386 int syslog_parse_priority(const char **p, int *priority, bool with_facility);
 387
 388 int version(void);
 389
 390 bool fdname_is_valid(const char *s);
 391
 392 bool oom_score_adjust_is_valid(int oa);