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 <dirent.h>
  26 #include <fcntl.h>
  27 #include <inttypes.h>
  28 #include <limits.h>
  29 #include <locale.h>
  30 #include <stdarg.h>
  31 #include <stdbool.h>
  32 #include <stddef.h>
  33 #include <stdio.h>
  34 #include <stdlib.h>
  35 #include <sys/inotify.h>
  36 #include <sys/socket.h>
  37 #include <sys/stat.h>
  38 #include <sys/statfs.h>
  39 #include <sys/types.h>
  40 #include <time.h>
  41 #include <unistd.h>
  42
  43 #include "formats-util.h"
  44 #include "macro.h"
  45 #include "missing.h"
  46 #include "time-util.h"
  47
  48 /* What is interpreted as whitespace? */
  49 #define WHITESPACE " \t\n\r"
  50 #define NEWLINE    "\n\r"
  51 #define QUOTES     "\"\'"
  52 #define COMMENTS   "#;"
  53 #define GLOB_CHARS "*?["
  54
  55 size_t page_size(void) _pure_;
  56 #define PAGE_ALIGN(l) ALIGN_TO((l), page_size())
  57
  58 #define new(t, n) ((t*) malloc_multiply(sizeof(t), (n)))
  59
  60 #define new0(t, n) ((t*) calloc((n), sizeof(t)))
  61
  62 #define newa(t, n) ((t*) alloca(sizeof(t)*(n)))
  63
  64 #define newa0(t, n) ((t*) alloca0(sizeof(t)*(n)))
  65
  66 #define newdup(t, p, n) ((t*) memdup_multiply(p, sizeof(t), (n)))
  67
  68 #define malloc0(n) (calloc(1, (n)))
  69
  70 static inline void *mfree(void *memory) {
  71         free(memory);
  72         return NULL;
  73 }
  74
  75 static inline const char* yes_no(bool b) {
  76         return b ? "yes" : "no";
  77 }
  78
  79 static inline const char* true_false(bool b) {
  80         return b ? "true" : "false";
  81 }
  82
  83 static inline const char* one_zero(bool b) {
  84         return b ? "1" : "0";
  85 }
  86
  87 int readlinkat_malloc(int fd, const char *p, char **ret);
  88 int readlink_malloc(const char *p, char **r);
  89 int readlink_value(const char *p, char **ret);
  90 int readlink_and_make_absolute(const char *p, char **r);
  91 int readlink_and_canonicalize(const char *p, char **r);
  92
  93 char *file_in_same_dir(const char *path, const char *filename);
  94
  95 int rmdir_parents(const char *path, const char *stop);
  96
  97 bool dirent_is_file(const struct dirent *de) _pure_;
  98 bool dirent_is_file_with_suffix(const struct dirent *de, const char *suffix) _pure_;
  99
 100 bool hidden_file(const char *filename) _pure_;
 101
 102 /* For basic lookup tables with strictly enumerated entries */
 103 #define _DEFINE_STRING_TABLE_LOOKUP_TO_STRING(name,type,scope)          \
 104         scope const char *name##_to_string(type i) {                    \
 105                 if (i < 0 || i >= (type) ELEMENTSOF(name##_table))      \
 106                         return NULL;                                    \
 107                 return name##_table[i];                                 \
 108         }
 109
 110 ssize_t string_table_lookup(const char * const *table, size_t len, const char *key);
 111
 112 #define _DEFINE_STRING_TABLE_LOOKUP_FROM_STRING(name,type,scope)        \
 113         scope type name##_from_string(const char *s) {                  \
 114                 return (type) string_table_lookup(name##_table, ELEMENTSOF(name##_table), s); \
 115         }
 116
 117 #define _DEFINE_STRING_TABLE_LOOKUP(name,type,scope)                    \
 118         _DEFINE_STRING_TABLE_LOOKUP_TO_STRING(name,type,scope)          \
 119         _DEFINE_STRING_TABLE_LOOKUP_FROM_STRING(name,type,scope)        \
 120         struct __useless_struct_to_allow_trailing_semicolon__
 121
 122 #define DEFINE_STRING_TABLE_LOOKUP(name,type) _DEFINE_STRING_TABLE_LOOKUP(name,type,)
 123 #define DEFINE_PRIVATE_STRING_TABLE_LOOKUP(name,type) _DEFINE_STRING_TABLE_LOOKUP(name,type,static)
 124 #define DEFINE_PRIVATE_STRING_TABLE_LOOKUP_TO_STRING(name,type) _DEFINE_STRING_TABLE_LOOKUP_TO_STRING(name,type,static)
 125 #define DEFINE_PRIVATE_STRING_TABLE_LOOKUP_FROM_STRING(name,type) _DEFINE_STRING_TABLE_LOOKUP_FROM_STRING(name,type,static)
 126
 127 /* For string conversions where numbers are also acceptable */
 128 #define DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(name,type,max)         \
 129         int name##_to_string_alloc(type i, char **str) {                \
 130                 char *s;                                                \
 131                 if (i < 0 || i > max)                                   \
 132                         return -ERANGE;                                 \
 133                 if (i < (type) ELEMENTSOF(name##_table)) {              \
 134                         s = strdup(name##_table[i]);                    \
 135                         if (!s)                                         \
 136                                 return -ENOMEM;                         \
 137                 } else {                                                \
 138                         if (asprintf(&s, "%i", i) < 0)                  \
 139                                 return -ENOMEM;                         \
 140                 }                                                       \
 141                 *str = s;                                               \
 142                 return 0;                                               \
 143         }                                                               \
 144         type name##_from_string(const char *s) {                        \
 145                 type i;                                                 \
 146                 unsigned u = 0;                                         \
 147                 if (!s)                                                 \
 148                         return (type) -1;                               \
 149                 for (i = 0; i < (type) ELEMENTSOF(name##_table); i++)   \
 150                         if (streq_ptr(name##_table[i], s))              \
 151                                 return i;                               \
 152                 if (safe_atou(s, &u) >= 0 && u <= max)                  \
 153                         return (type) u;                                \
 154                 return (type) -1;                                       \
 155         }                                                               \
 156         struct __useless_struct_to_allow_trailing_semicolon__
 157
 158 bool fstype_is_network(const char *fstype);
 159
 160 bool is_device_path(const char *path);
 161
 162 int dir_is_empty(const char *path);
 163
 164 static inline int dir_is_populated(const char *path) {
 165         int r;
 166         r = dir_is_empty(path);
 167         if (r < 0)
 168                 return r;
 169         return !r;
 170 }
 171
 172 int chmod_and_chown(const char *path, mode_t mode, uid_t uid, gid_t gid);
 173 int fchmod_and_fchown(int fd, mode_t mode, uid_t uid, gid_t gid);
 174
 175 typedef long statfs_f_type_t;
 176
 177 bool is_fs_type(const struct statfs *s, statfs_f_type_t magic_value) _pure_;
 178 int fd_check_fstype(int fd, statfs_f_type_t magic_value);
 179 int path_check_fstype(const char *path, statfs_f_type_t magic_value);
 180
 181 bool is_temporary_fs(const struct statfs *s) _pure_;
 182 int fd_is_temporary_fs(int fd);
 183
 184 #define xsprintf(buf, fmt, ...) \
 185         assert_message_se((size_t) snprintf(buf, ELEMENTSOF(buf), fmt, __VA_ARGS__) < ELEMENTSOF(buf), \
 186                           "xsprintf: " #buf "[] must be big enough")
 187
 188 int files_same(const char *filea, const char *fileb);
 189
 190 int running_in_chroot(void);
 191
 192 int touch_file(const char *path, bool parents, usec_t stamp, uid_t uid, gid_t gid, mode_t mode);
 193 int touch(const char *path);
 194
 195 noreturn void freeze(void);
 196
 197 bool null_or_empty(struct stat *st) _pure_;
 198 int null_or_empty_path(const char *fn);
 199 int null_or_empty_fd(int fd);
 200
 201 void execute_directories(const char* const* directories, usec_t timeout, char *argv[]);
 202
 203 bool plymouth_running(void);
 204
 205 int symlink_idempotent(const char *from, const char *to);
 206
 207 int symlink_atomic(const char *from, const char *to);
 208 int mknod_atomic(const char *path, mode_t mode, dev_t dev);
 209 int mkfifo_atomic(const char *path, mode_t mode);
 210
 211 int fchmod_umask(int fd, mode_t mode);
 212
 213 bool display_is_local(const char *display) _pure_;
 214 int socket_from_display(const char *display, char **path);
 215
 216 int glob_exists(const char *path);
 217 int glob_extend(char ***strv, const char *path);
 218
 219 int dirent_ensure_type(DIR *d, struct dirent *de);
 220
 221 int get_files_in_directory(const char *path, char ***list);
 222
 223 bool is_main_thread(void);
 224
 225 int block_get_whole_disk(dev_t d, dev_t *ret);
 226
 227 #define NULSTR_FOREACH(i, l)                                    \
 228         for ((i) = (l); (i) && *(i); (i) = strchr((i), 0)+1)
 229
 230 #define NULSTR_FOREACH_PAIR(i, j, l)                             \
 231         for ((i) = (l), (j) = strchr((i), 0)+1; (i) && *(i); (i) = strchr((j), 0)+1, (j) = *(i) ? strchr((i), 0)+1 : (i))
 232
 233 int ioprio_class_to_string_alloc(int i, char **s);
 234 int ioprio_class_from_string(const char *s);
 235
 236 const char *sigchld_code_to_string(int i) _const_;
 237 int sigchld_code_from_string(const char *s) _pure_;
 238
 239 int log_facility_unshifted_to_string_alloc(int i, char **s);
 240 int log_facility_unshifted_from_string(const char *s);
 241 bool log_facility_unshifted_is_valid(int faciliy);
 242
 243 int log_level_to_string_alloc(int i, char **s);
 244 int log_level_from_string(const char *s);
 245 bool log_level_is_valid(int level);
 246
 247 int sched_policy_to_string_alloc(int i, char **s);
 248 int sched_policy_from_string(const char *s);
 249
 250 const char *rlimit_to_string(int i) _const_;
 251 int rlimit_from_string(const char *s) _pure_;
 252
 253 extern int saved_argc;
 254 extern char **saved_argv;
 255
 256 bool kexec_loaded(void);
 257
 258 int prot_from_flags(int flags) _const_;
 259
 260 void* memdup(const void *p, size_t l) _alloc_(2);
 261
 262 int fork_agent(pid_t *pid, const int except[], unsigned n_except, const char *path, ...);
 263
 264 int setrlimit_closest(int resource, const struct rlimit *rlim);
 265
 266 bool http_url_is_valid(const char *url) _pure_;
 267 bool documentation_url_is_valid(const char *url) _pure_;
 268
 269 bool http_etag_is_valid(const char *etag);
 270
 271 bool in_initrd(void);
 272
 273 static inline void freep(void *p) {
 274         free(*(void**) p);
 275 }
 276
 277 static inline void umaskp(mode_t *u) {
 278         umask(*u);
 279 }
 280
 281 #define _cleanup_free_ _cleanup_(freep)
 282 #define _cleanup_umask_ _cleanup_(umaskp)
 283 #define _cleanup_globfree_ _cleanup_(globfree)
 284
 285 _malloc_  _alloc_(1, 2) static inline void *malloc_multiply(size_t a, size_t b) {
 286         if (_unlikely_(b != 0 && a > ((size_t) -1) / b))
 287                 return NULL;
 288
 289         return malloc(a * b);
 290 }
 291
 292 _alloc_(2, 3) static inline void *realloc_multiply(void *p, size_t a, size_t b) {
 293         if (_unlikely_(b != 0 && a > ((size_t) -1) / b))
 294                 return NULL;
 295
 296         return realloc(p, a * b);
 297 }
 298
 299 _alloc_(2, 3) static inline void *memdup_multiply(const void *p, size_t a, size_t b) {
 300         if (_unlikely_(b != 0 && a > ((size_t) -1) / b))
 301                 return NULL;
 302
 303         return memdup(p, a * b);
 304 }
 305
 306 bool string_is_safe(const char *p) _pure_;
 307
 308 /**
 309  * Check if a string contains any glob patterns.
 310  */
 311 _pure_ static inline bool string_is_glob(const char *p) {
 312         return !!strpbrk(p, GLOB_CHARS);
 313 }
 314
 315 void *xbsearch_r(const void *key, const void *base, size_t nmemb, size_t size,
 316                  int (*compar) (const void *, const void *, void *),
 317                  void *arg);
 318
 319 #define _(String) gettext (String)
 320 #define N_(String) String
 321 void init_gettext(void);
 322 bool is_locale_utf8(void);
 323
 324 typedef enum DrawSpecialChar {
 325         DRAW_TREE_VERTICAL,
 326         DRAW_TREE_BRANCH,
 327         DRAW_TREE_RIGHT,
 328         DRAW_TREE_SPACE,
 329         DRAW_TRIANGULAR_BULLET,
 330         DRAW_BLACK_CIRCLE,
 331         DRAW_ARROW,
 332         DRAW_DASH,
 333         _DRAW_SPECIAL_CHAR_MAX
 334 } DrawSpecialChar;
 335
 336 const char *draw_special_char(DrawSpecialChar ch);
 337
 338 int on_ac_power(void);
 339
 340 #define FOREACH_DIRENT(de, d, on_error)                                 \
 341         for (errno = 0, de = readdir(d);; errno = 0, de = readdir(d))   \
 342                 if (!de) {                                              \
 343                         if (errno > 0) {                                \
 344                                 on_error;                               \
 345                         }                                               \
 346                         break;                                          \
 347                 } else if (hidden_file((de)->d_name))                   \
 348                         continue;                                       \
 349                 else
 350
 351 #define FOREACH_DIRENT_ALL(de, d, on_error)                             \
 352         for (errno = 0, de = readdir(d);; errno = 0, de = readdir(d))   \
 353                 if (!de) {                                              \
 354                         if (errno > 0) {                                \
 355                                 on_error;                               \
 356                         }                                               \
 357                         break;                                          \
 358                 } else
 359
 360 static inline void *mempset(void *s, int c, size_t n) {
 361         memset(s, c, n);
 362         return (uint8_t*)s + n;
 363 }
 364
 365 void* greedy_realloc(void **p, size_t *allocated, size_t need, size_t size);
 366 void* greedy_realloc0(void **p, size_t *allocated, size_t need, size_t size);
 367 #define GREEDY_REALLOC(array, allocated, need)                          \
 368         greedy_realloc((void**) &(array), &(allocated), (need), sizeof((array)[0]))
 369
 370 #define GREEDY_REALLOC0(array, allocated, need)                         \
 371         greedy_realloc0((void**) &(array), &(allocated), (need), sizeof((array)[0]))
 372
 373 static inline void _reset_errno_(int *saved_errno) {
 374         errno = *saved_errno;
 375 }
 376
 377 #define PROTECT_ERRNO _cleanup_(_reset_errno_) __attribute__((unused)) int _saved_errno_ = errno
 378
 379 static inline int negative_errno(void) {
 380         /* This helper should be used to shut up gcc if you know 'errno' is
 381          * negative. Instead of "return -errno;", use "return negative_errno();"
 382          * It will suppress bogus gcc warnings in case it assumes 'errno' might
 383          * be 0 and thus the caller's error-handling might not be triggered. */
 384         assert_return(errno > 0, -EINVAL);
 385         return -errno;
 386 }
 387
 388 struct _umask_struct_ {
 389         mode_t mask;
 390         bool quit;
 391 };
 392
 393 static inline void _reset_umask_(struct _umask_struct_ *s) {
 394         umask(s->mask);
 395 };
 396
 397 #define RUN_WITH_UMASK(mask)                                            \
 398         for (_cleanup_(_reset_umask_) struct _umask_struct_ _saved_umask_ = { umask(mask), false }; \
 399              !_saved_umask_.quit ;                                      \
 400              _saved_umask_.quit = true)
 401
 402 static inline unsigned u64log2(uint64_t n) {
 403 #if __SIZEOF_LONG_LONG__ == 8
 404         return (n > 1) ? (unsigned) __builtin_clzll(n) ^ 63U : 0;
 405 #else
 406 #error "Wut?"
 407 #endif
 408 }
 409
 410 static inline unsigned u32ctz(uint32_t n) {
 411 #if __SIZEOF_INT__ == 4
 412         return __builtin_ctz(n);
 413 #else
 414 #error "Wut?"
 415 #endif
 416 }
 417
 418 static inline unsigned log2i(int x) {
 419         assert(x > 0);
 420
 421         return __SIZEOF_INT__ * 8 - __builtin_clz(x) - 1;
 422 }
 423
 424 static inline unsigned log2u(unsigned x) {
 425         assert(x > 0);
 426
 427         return sizeof(unsigned) * 8 - __builtin_clz(x) - 1;
 428 }
 429
 430 static inline unsigned log2u_round_up(unsigned x) {
 431         assert(x > 0);
 432
 433         if (x == 1)
 434                 return 0;
 435
 436         return log2u(x - 1) + 1;
 437 }
 438
 439 #define DECIMAL_STR_WIDTH(x)                            \
 440         ({                                              \
 441                 typeof(x) _x_ = (x);                    \
 442                 unsigned ans = 1;                       \
 443                 while (_x_ /= 10)                       \
 444                         ans++;                          \
 445                 ans;                                    \
 446         })
 447
 448 int unlink_noerrno(const char *path);
 449
 450 #define alloca0(n)                                      \
 451         ({                                              \
 452                 char *_new_;                            \
 453                 size_t _len_ = n;                       \
 454                 _new_ = alloca(_len_);                  \
 455                 (void *) memset(_new_, 0, _len_);       \
 456         })
 457
 458 /* It's not clear what alignment glibc/gcc alloca() guarantee, hence provide a guaranteed safe version */
 459 #define alloca_align(size, align)                                       \
 460         ({                                                              \
 461                 void *_ptr_;                                            \
 462                 size_t _mask_ = (align) - 1;                            \
 463                 _ptr_ = alloca((size) + _mask_);                        \
 464                 (void*)(((uintptr_t)_ptr_ + _mask_) & ~_mask_);         \
 465         })
 466
 467 #define alloca0_align(size, align)                                      \
 468         ({                                                              \
 469                 void *_new_;                                            \
 470                 size_t _size_ = (size);                                 \
 471                 _new_ = alloca_align(_size_, (align));                  \
 472                 (void*)memset(_new_, 0, _size_);                        \
 473         })
 474
 475 bool id128_is_valid(const char *s) _pure_;
 476
 477 int shall_restore_state(void);
 478
 479 /**
 480  * Normal qsort requires base to be nonnull. Here were require
 481  * that only if nmemb > 0.
 482  */
 483 static inline void qsort_safe(void *base, size_t nmemb, size_t size, comparison_fn_t compar) {
 484         if (nmemb <= 1)
 485                 return;
 486
 487         assert(base);
 488         qsort(base, nmemb, size, compar);
 489 }
 490
 491 int proc_cmdline(char **ret);
 492 int parse_proc_cmdline(int (*parse_word)(const char *key, const char *value));
 493 int get_proc_cmdline_key(const char *parameter, char **value);
 494
 495 int container_get_leader(const char *machine, pid_t *pid);
 496
 497 int namespace_open(pid_t pid, int *pidns_fd, int *mntns_fd, int *netns_fd, int *userns_fd, int *root_fd);
 498 int namespace_enter(int pidns_fd, int mntns_fd, int netns_fd, int userns_fd, int root_fd);
 499
 500 int fd_warn_permissions(const char *path, int fd);
 501
 502 #ifndef PERSONALITY_INVALID
 503 /* personality(7) documents that 0xffffffffUL is used for querying the
 504  * current personality, hence let's use that here as error
 505  * indicator. */
 506 #define PERSONALITY_INVALID 0xffffffffLU
 507 #endif
 508
 509 unsigned long personality_from_string(const char *p);
 510 const char *personality_to_string(unsigned long);
 511
 512 uint64_t physical_memory(void);
 513
 514 union file_handle_union {
 515         struct file_handle handle;
 516         char padding[sizeof(struct file_handle) + MAX_HANDLE_SZ];
 517 };
 518 #define FILE_HANDLE_INIT { .handle.handle_bytes = MAX_HANDLE_SZ }
 519
 520 int update_reboot_param_file(const char *param);
 521
 522 int is_symlink(const char *path);
 523 int is_dir(const char *path, bool follow);
 524 int is_device_node(const char *path);
 525
 526 #define INOTIFY_EVENT_MAX (sizeof(struct inotify_event) + NAME_MAX + 1)
 527
 528 #define FOREACH_INOTIFY_EVENT(e, buffer, sz) \
 529         for ((e) = &buffer.ev;                                \
 530              (uint8_t*) (e) < (uint8_t*) (buffer.raw) + (sz); \
 531              (e) = (struct inotify_event*) ((uint8_t*) (e) + sizeof(struct inotify_event) + (e)->len))
 532
 533 union inotify_event_buffer {
 534         struct inotify_event ev;
 535         uint8_t raw[INOTIFY_EVENT_MAX];
 536 };
 537
 538 #define laccess(path, mode) faccessat(AT_FDCWD, (path), (mode), AT_SYMLINK_NOFOLLOW)
 539
 540 ssize_t fgetxattrat_fake(int dirfd, const char *filename, const char *attribute, void *value, size_t size, int flags);
 541
 542 int fd_setcrtime(int fd, usec_t usec);
 543 int fd_getcrtime(int fd, usec_t *usec);
 544 int path_getcrtime(const char *p, usec_t *usec);
 545 int fd_getcrtime_at(int dirfd, const char *name, usec_t *usec, int flags);
 546
 547 int chattr_fd(int fd, unsigned value, unsigned mask);
 548 int chattr_path(const char *p, unsigned value, unsigned mask);
 549
 550 int read_attr_fd(int fd, unsigned *ret);
 551 int read_attr_path(const char *p, unsigned *ret);
 552
 553 #define RLIMIT_MAKE_CONST(lim) ((struct rlimit) { lim, lim })
 554
 555 int syslog_parse_priority(const char **p, int *priority, bool with_facility);
 556
 557 int rename_noreplace(int olddirfd, const char *oldpath, int newdirfd, const char *newpath);
 558
 559 int getxattr_malloc(const char *path, const char *name, char **value, bool allow_symlink);
 560 int fgetxattr_malloc(int fd, const char *name, char **value);
 561
 562 int version(void);
 563
 564 bool fdname_is_valid(const char *s);
 565
 566 bool oom_score_adjust_is_valid(int oa);