src/basic/fileio.h

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2 #pragma once
   3
   4 #include <dirent.h>
   5 #include <stdbool.h>
   6 #include <stddef.h>
   7 #include <stdio.h>
   8 #include <sys/stat.h>
   9 #include <sys/fcntl.h>
  10 #include <sys/types.h>
  11
  12 #include "macro.h"
  13 #include "time-util.h"
  14
  15 #define LONG_LINE_MAX (1U*1024U*1024U)
  16
  17 typedef enum {
  18         WRITE_STRING_FILE_CREATE            = 1 << 0,
  19         WRITE_STRING_FILE_TRUNCATE          = 1 << 1,
  20         WRITE_STRING_FILE_ATOMIC            = 1 << 2,
  21         WRITE_STRING_FILE_AVOID_NEWLINE     = 1 << 3,
  22         WRITE_STRING_FILE_VERIFY_ON_FAILURE = 1 << 4,
  23         WRITE_STRING_FILE_SYNC              = 1 << 5,
  24         WRITE_STRING_FILE_DISABLE_BUFFER    = 1 << 6,
  25         WRITE_STRING_FILE_NOFOLLOW          = 1 << 7,
  26         WRITE_STRING_FILE_MKDIR_0755        = 1 << 8,
  27         WRITE_STRING_FILE_MODE_0600         = 1 << 9,
  28
  29         /* And before you wonder, why write_string_file_atomic_label_ts() is a separate function instead of just one
  30            more flag here: it's about linking: we don't want to pull -lselinux into all users of write_string_file()
  31            and friends. */
  32
  33 } WriteStringFileFlags;
  34
  35 typedef enum {
  36         READ_FULL_FILE_SECURE              = 1 << 0, /* erase any buffers we employ internally, after use */
  37         READ_FULL_FILE_UNBASE64            = 1 << 1, /* base64 decode what we read */
  38         READ_FULL_FILE_UNHEX               = 1 << 2, /* hex decode what we read */
  39         READ_FULL_FILE_WARN_WORLD_READABLE = 1 << 3, /* if regular file, log at LOG_WARNING level if access mode above 0700 */
  40         READ_FULL_FILE_CONNECT_SOCKET      = 1 << 4, /* if socket inode, connect to it and read off it */
  41 } ReadFullFileFlags;
  42
  43 int fopen_unlocked(const char *path, const char *options, FILE **ret);
  44 int fdopen_unlocked(int fd, const char *options, FILE **ret);
  45 int take_fdopen_unlocked(int *fd, const char *options, FILE **ret);
  46 FILE* take_fdopen(int *fd, const char *options);
  47 DIR* take_fdopendir(int *dfd);
  48 FILE* open_memstream_unlocked(char **ptr, size_t *sizeloc);
  49 FILE* fmemopen_unlocked(void *buf, size_t size, const char *mode);
  50
  51 int write_string_stream_ts(FILE *f, const char *line, WriteStringFileFlags flags, const struct timespec *ts);
  52 static inline int write_string_stream(FILE *f, const char *line, WriteStringFileFlags flags) {
  53         return write_string_stream_ts(f, line, flags, NULL);
  54 }
  55 int write_string_file_ts(const char *fn, const char *line, WriteStringFileFlags flags, const struct timespec *ts);
  56 static inline int write_string_file(const char *fn, const char *line, WriteStringFileFlags flags) {
  57         return write_string_file_ts(fn, line, flags, NULL);
  58 }
  59
  60 int write_string_filef(const char *fn, WriteStringFileFlags flags, const char *format, ...) _printf_(3, 4);
  61
  62 int read_one_line_file(const char *filename, char **line);
  63 int read_full_file_full(int dir_fd, const char *filename, uint64_t offset, size_t size, ReadFullFileFlags flags, const char *bind_name, char **ret_contents, size_t *ret_size);
  64 static inline int read_full_file(const char *filename, char **ret_contents, size_t *ret_size) {
  65         return read_full_file_full(AT_FDCWD, filename, UINT64_MAX, SIZE_MAX, 0, NULL, ret_contents, ret_size);
  66 }
  67 int read_full_virtual_file(const char *filename, char **ret_contents, size_t *ret_size);
  68 int read_full_stream_full(FILE *f, const char *filename, uint64_t offset, size_t size, ReadFullFileFlags flags, char **ret_contents, size_t *ret_size);
  69 static inline int read_full_stream(FILE *f, char **ret_contents, size_t *ret_size) {
  70         return read_full_stream_full(f, NULL, UINT64_MAX, SIZE_MAX, 0, ret_contents, ret_size);
  71 }
  72
  73 int verify_file(const char *fn, const char *blob, bool accept_extra_nl);
  74
  75 int executable_is_script(const char *path, char **interpreter);
  76
  77 int get_proc_field(const char *filename, const char *pattern, const char *terminator, char **field);
  78
  79 DIR *xopendirat(int dirfd, const char *name, int flags);
  80 int xfopenat(int dir_fd, const char *path, const char *mode, int flags, FILE **ret);
  81
  82 int search_and_fopen(const char *path, const char *mode, const char *root, const char **search, FILE **_f);
  83 int search_and_fopen_nulstr(const char *path, const char *mode, const char *root, const char *search, FILE **_f);
  84
  85 int chase_symlinks_and_fopen_unlocked(
  86                 const char *path,
  87                 const char *root,
  88                 unsigned chase_flags,
  89                 const char *open_flags,
  90                 FILE **ret_file,
  91                 char **ret_path);
  92
  93 int fflush_and_check(FILE *f);
  94 int fflush_sync_and_check(FILE *f);
  95
  96 int write_timestamp_file_atomic(const char *fn, usec_t n);
  97 int read_timestamp_file(const char *fn, usec_t *ret);
  98
  99 int fputs_with_space(FILE *f, const char *s, const char *separator, bool *space);
 100
 101 typedef enum ReadLineFlags {
 102         READ_LINE_ONLY_NUL  = 1 << 0,
 103         READ_LINE_IS_A_TTY  = 1 << 1,
 104         READ_LINE_NOT_A_TTY = 1 << 2,
 105 } ReadLineFlags;
 106
 107 int read_line_full(FILE *f, size_t limit, ReadLineFlags flags, char **ret);
 108
 109 static inline int read_line(FILE *f, size_t limit, char **ret) {
 110         return read_line_full(f, limit, 0, ret);
 111 }
 112
 113 static inline int read_nul_string(FILE *f, size_t limit, char **ret) {
 114         return read_line_full(f, limit, READ_LINE_ONLY_NUL, ret);
 115 }
 116
 117 int safe_fgetc(FILE *f, char *ret);
 118
 119 int warn_file_is_world_accessible(const char *filename, struct stat *st, const char *unit, unsigned line);
 120
 121 int rename_and_apply_smack_floor_label(const char *temp_path, const char *dest_path);