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 filename_is_valid(const char *p) _pure_;
 307 bool path_is_safe(const char *p) _pure_;
 308 bool string_is_safe(const char *p) _pure_;
 309
 310 /**
 311  * Check if a string contains any glob patterns.
 312  */
 313 _pure_ static inline bool string_is_glob(const char *p) {
 314         return !!strpbrk(p, GLOB_CHARS);
 315 }
 316
 317 void *xbsearch_r(const void *key, const void *base, size_t nmemb, size_t size,
 318                  int (*compar) (const void *, const void *, void *),
 319                  void *arg);
 320
 321 #define _(String) gettext (String)
 322 #define N_(String) String
 323 void init_gettext(void);
 324 bool is_locale_utf8(void);
 325
 326 typedef enum DrawSpecialChar {
 327         DRAW_TREE_VERTICAL,
 328         DRAW_TREE_BRANCH,
 329         DRAW_TREE_RIGHT,
 330         DRAW_TREE_SPACE,
 331         DRAW_TRIANGULAR_BULLET,
 332         DRAW_BLACK_CIRCLE,
 333         DRAW_ARROW,
 334         DRAW_DASH,
 335         _DRAW_SPECIAL_CHAR_MAX
 336 } DrawSpecialChar;
 337
 338 const char *draw_special_char(DrawSpecialChar ch);
 339
 340 int on_ac_power(void);
 341
 342 #define FOREACH_DIRENT(de, d, on_error)                                 \
 343         for (errno = 0, de = readdir(d);; errno = 0, de = readdir(d))   \
 344                 if (!de) {                                              \
 345                         if (errno > 0) {                                \
 346                                 on_error;                               \
 347                         }                                               \
 348                         break;                                          \
 349                 } else if (hidden_file((de)->d_name))                   \
 350                         continue;                                       \
 351                 else
 352
 353 #define FOREACH_DIRENT_ALL(de, d, on_error)                             \
 354         for (errno = 0, de = readdir(d);; errno = 0, de = readdir(d))   \
 355                 if (!de) {                                              \
 356                         if (errno > 0) {                                \
 357                                 on_error;                               \
 358                         }                                               \
 359                         break;                                          \
 360                 } else
 361
 362 static inline void *mempset(void *s, int c, size_t n) {
 363         memset(s, c, n);
 364         return (uint8_t*)s + n;
 365 }
 366
 367 void* greedy_realloc(void **p, size_t *allocated, size_t need, size_t size);
 368 void* greedy_realloc0(void **p, size_t *allocated, size_t need, size_t size);
 369 #define GREEDY_REALLOC(array, allocated, need)                          \
 370         greedy_realloc((void**) &(array), &(allocated), (need), sizeof((array)[0]))
 371
 372 #define GREEDY_REALLOC0(array, allocated, need)                         \
 373         greedy_realloc0((void**) &(array), &(allocated), (need), sizeof((array)[0]))
 374
 375 static inline void _reset_errno_(int *saved_errno) {
 376         errno = *saved_errno;
 377 }
 378
 379 #define PROTECT_ERRNO _cleanup_(_reset_errno_) __attribute__((unused)) int _saved_errno_ = errno
 380
 381 static inline int negative_errno(void) {
 382         /* This helper should be used to shut up gcc if you know 'errno' is
 383          * negative. Instead of "return -errno;", use "return negative_errno();"
 384          * It will suppress bogus gcc warnings in case it assumes 'errno' might
 385          * be 0 and thus the caller's error-handling might not be triggered. */
 386         assert_return(errno > 0, -EINVAL);
 387         return -errno;
 388 }
 389
 390 struct _umask_struct_ {
 391         mode_t mask;
 392         bool quit;
 393 };
 394
 395 static inline void _reset_umask_(struct _umask_struct_ *s) {
 396         umask(s->mask);
 397 };
 398
 399 #define RUN_WITH_UMASK(mask)                                            \
 400         for (_cleanup_(_reset_umask_) struct _umask_struct_ _saved_umask_ = { umask(mask), false }; \
 401              !_saved_umask_.quit ;                                      \
 402              _saved_umask_.quit = true)
 403
 404 static inline unsigned u64log2(uint64_t n) {
 405 #if __SIZEOF_LONG_LONG__ == 8
 406         return (n > 1) ? (unsigned) __builtin_clzll(n) ^ 63U : 0;
 407 #else
 408 #error "Wut?"
 409 #endif
 410 }
 411
 412 static inline unsigned u32ctz(uint32_t n) {
 413 #if __SIZEOF_INT__ == 4
 414         return __builtin_ctz(n);
 415 #else
 416 #error "Wut?"
 417 #endif
 418 }
 419
 420 static inline unsigned log2i(int x) {
 421         assert(x > 0);
 422
 423         return __SIZEOF_INT__ * 8 - __builtin_clz(x) - 1;
 424 }
 425
 426 static inline unsigned log2u(unsigned x) {
 427         assert(x > 0);
 428
 429         return sizeof(unsigned) * 8 - __builtin_clz(x) - 1;
 430 }
 431
 432 static inline unsigned log2u_round_up(unsigned x) {
 433         assert(x > 0);
 434
 435         if (x == 1)
 436                 return 0;
 437
 438         return log2u(x - 1) + 1;
 439 }
 440
 441 #define DECIMAL_STR_WIDTH(x)                            \
 442         ({                                              \
 443                 typeof(x) _x_ = (x);                    \
 444                 unsigned ans = 1;                       \
 445                 while (_x_ /= 10)                       \
 446                         ans++;                          \
 447                 ans;                                    \
 448         })
 449
 450 int unlink_noerrno(const char *path);
 451
 452 #define alloca0(n)                                      \
 453         ({                                              \
 454                 char *_new_;                            \
 455                 size_t _len_ = n;                       \
 456                 _new_ = alloca(_len_);                  \
 457                 (void *) memset(_new_, 0, _len_);       \
 458         })
 459
 460 /* It's not clear what alignment glibc/gcc alloca() guarantee, hence provide a guaranteed safe version */
 461 #define alloca_align(size, align)                                       \
 462         ({                                                              \
 463                 void *_ptr_;                                            \
 464                 size_t _mask_ = (align) - 1;                            \
 465                 _ptr_ = alloca((size) + _mask_);                        \
 466                 (void*)(((uintptr_t)_ptr_ + _mask_) & ~_mask_);         \
 467         })
 468
 469 #define alloca0_align(size, align)                                      \
 470         ({                                                              \
 471                 void *_new_;                                            \
 472                 size_t _size_ = (size);                                 \
 473                 _new_ = alloca_align(_size_, (align));                  \
 474                 (void*)memset(_new_, 0, _size_);                        \
 475         })
 476
 477 bool id128_is_valid(const char *s) _pure_;
 478
 479 int shall_restore_state(void);
 480
 481 /**
 482  * Normal qsort requires base to be nonnull. Here were require
 483  * that only if nmemb > 0.
 484  */
 485 static inline void qsort_safe(void *base, size_t nmemb, size_t size, comparison_fn_t compar) {
 486         if (nmemb <= 1)
 487                 return;
 488
 489         assert(base);
 490         qsort(base, nmemb, size, compar);
 491 }
 492
 493 int proc_cmdline(char **ret);
 494 int parse_proc_cmdline(int (*parse_word)(const char *key, const char *value));
 495 int get_proc_cmdline_key(const char *parameter, char **value);
 496
 497 int container_get_leader(const char *machine, pid_t *pid);
 498
 499 int namespace_open(pid_t pid, int *pidns_fd, int *mntns_fd, int *netns_fd, int *userns_fd, int *root_fd);
 500 int namespace_enter(int pidns_fd, int mntns_fd, int netns_fd, int userns_fd, int root_fd);
 501
 502 int fd_warn_permissions(const char *path, int fd);
 503
 504 #ifndef PERSONALITY_INVALID
 505 /* personality(7) documents that 0xffffffffUL is used for querying the
 506  * current personality, hence let's use that here as error
 507  * indicator. */
 508 #define PERSONALITY_INVALID 0xffffffffLU
 509 #endif
 510
 511 unsigned long personality_from_string(const char *p);
 512 const char *personality_to_string(unsigned long);
 513
 514 uint64_t physical_memory(void);
 515
 516 union file_handle_union {
 517         struct file_handle handle;
 518         char padding[sizeof(struct file_handle) + MAX_HANDLE_SZ];
 519 };
 520 #define FILE_HANDLE_INIT { .handle.handle_bytes = MAX_HANDLE_SZ }
 521
 522 int update_reboot_param_file(const char *param);
 523
 524 int take_password_lock(const char *root);
 525
 526 int is_symlink(const char *path);
 527 int is_dir(const char *path, bool follow);
 528 int is_device_node(const char *path);
 529
 530 #define INOTIFY_EVENT_MAX (sizeof(struct inotify_event) + NAME_MAX + 1)
 531
 532 #define FOREACH_INOTIFY_EVENT(e, buffer, sz) \
 533         for ((e) = &buffer.ev;                                \
 534              (uint8_t*) (e) < (uint8_t*) (buffer.raw) + (sz); \
 535              (e) = (struct inotify_event*) ((uint8_t*) (e) + sizeof(struct inotify_event) + (e)->len))
 536
 537 union inotify_event_buffer {
 538         struct inotify_event ev;
 539         uint8_t raw[INOTIFY_EVENT_MAX];
 540 };
 541
 542 #define laccess(path, mode) faccessat(AT_FDCWD, (path), (mode), AT_SYMLINK_NOFOLLOW)
 543
 544 ssize_t fgetxattrat_fake(int dirfd, const char *filename, const char *attribute, void *value, size_t size, int flags);
 545
 546 int fd_setcrtime(int fd, usec_t usec);
 547 int fd_getcrtime(int fd, usec_t *usec);
 548 int path_getcrtime(const char *p, usec_t *usec);
 549 int fd_getcrtime_at(int dirfd, const char *name, usec_t *usec, int flags);
 550
 551 int chattr_fd(int fd, unsigned value, unsigned mask);
 552 int chattr_path(const char *p, unsigned value, unsigned mask);
 553
 554 int read_attr_fd(int fd, unsigned *ret);
 555 int read_attr_path(const char *p, unsigned *ret);
 556
 557 #define RLIMIT_MAKE_CONST(lim) ((struct rlimit) { lim, lim })
 558
 559 int syslog_parse_priority(const char **p, int *priority, bool with_facility);
 560
 561 int rename_noreplace(int olddirfd, const char *oldpath, int newdirfd, const char *newpath);
 562
 563 int getxattr_malloc(const char *path, const char *name, char **value, bool allow_symlink);
 564 int fgetxattr_malloc(int fd, const char *name, char **value);
 565
 566 int version(void);
 567
 568 bool fdname_is_valid(const char *s);
 569
 570 bool oom_score_adjust_is_valid(int oa);