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_VERIFY_IGNORE_NEWLINE = 1 << 5,
  24         WRITE_STRING_FILE_SYNC                  = 1 << 6,
  25         WRITE_STRING_FILE_DISABLE_BUFFER        = 1 << 7,
  26         WRITE_STRING_FILE_NOFOLLOW              = 1 << 8,
  27         WRITE_STRING_FILE_MKDIR_0755            = 1 << 9,
  28         WRITE_STRING_FILE_MODE_0600             = 1 << 10,
  29
  30         /* And before you wonder, why write_string_file_atomic_label_ts() is a separate function instead of just one
  31            more flag here: it's about linking: we don't want to pull -lselinux into all users of write_string_file()
  32            and friends. */
  33
  34 } WriteStringFileFlags;
  35
  36 typedef enum {
  37         READ_FULL_FILE_SECURE              = 1 << 0, /* erase any buffers we employ internally, after use */
  38         READ_FULL_FILE_UNBASE64            = 1 << 1, /* base64 decode what we read */
  39         READ_FULL_FILE_UNHEX               = 1 << 2, /* hex decode what we read */
  40         READ_FULL_FILE_WARN_WORLD_READABLE = 1 << 3, /* if regular file, log at LOG_WARNING level if access mode above 0700 */
  41         READ_FULL_FILE_CONNECT_SOCKET      = 1 << 4, /* if socket inode, connect to it and read off it */
  42         READ_FULL_FILE_FAIL_WHEN_LARGER    = 1 << 5, /* fail loading if file is larger than specified size */
  43 } ReadFullFileFlags;
  44
  45 int fopen_unlocked(const char *path, const char *options, FILE **ret);
  46 int fdopen_unlocked(int fd, const char *options, FILE **ret);
  47 int take_fdopen_unlocked(int *fd, const char *options, FILE **ret);
  48 FILE* take_fdopen(int *fd, const char *options);
  49 DIR* take_fdopendir(int *dfd);
  50 FILE* open_memstream_unlocked(char **ptr, size_t *sizeloc);
  51 FILE* fmemopen_unlocked(void *buf, size_t size, const char *mode);
  52
  53 int write_string_stream_ts(FILE *f, const char *line, WriteStringFileFlags flags, const struct timespec *ts);
  54 static inline int write_string_stream(FILE *f, const char *line, WriteStringFileFlags flags) {
  55         return write_string_stream_ts(f, line, flags, NULL);
  56 }
  57 int write_string_file_ts(const char *fn, const char *line, WriteStringFileFlags flags, const struct timespec *ts);
  58 static inline int write_string_file(const char *fn, const char *line, WriteStringFileFlags flags) {
  59         return write_string_file_ts(fn, line, flags, NULL);
  60 }
  61
  62 int write_string_filef(const char *fn, WriteStringFileFlags flags, const char *format, ...) _printf_(3, 4);
  63
  64 int read_one_line_file(const char *filename, char **line);
  65 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);
  66 static inline int read_full_file(const char *filename, char **ret_contents, size_t *ret_size) {
  67         return read_full_file_full(AT_FDCWD, filename, UINT64_MAX, SIZE_MAX, 0, NULL, ret_contents, ret_size);
  68 }
  69
  70 int read_virtual_file(const char *filename, size_t max_size, char **ret_contents, size_t *ret_size);
  71 static inline int read_full_virtual_file(const char *filename, char **ret_contents, size_t *ret_size) {
  72         return read_virtual_file(filename, SIZE_MAX, ret_contents, ret_size);
  73 }
  74
  75 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);
  76 static inline int read_full_stream(FILE *f, char **ret_contents, size_t *ret_size) {
  77         return read_full_stream_full(f, NULL, UINT64_MAX, SIZE_MAX, 0, ret_contents, ret_size);
  78 }
  79
  80 int verify_file(const char *fn, const char *blob, bool accept_extra_nl);
  81
  82 int executable_is_script(const char *path, char **interpreter);
  83
  84 int get_proc_field(const char *filename, const char *pattern, const char *terminator, char **field);
  85
  86 DIR *xopendirat(int dirfd, const char *name, int flags);
  87 int xfopenat(int dir_fd, const char *path, const char *mode, int flags, FILE **ret);
  88
  89 int search_and_fopen(const char *path, const char *mode, const char *root, const char **search, FILE **ret, char **ret_path);
  90 int search_and_fopen_nulstr(const char *path, const char *mode, const char *root, const char *search, FILE **ret, char **ret_path);
  91
  92 int chase_symlinks_and_fopen_unlocked(
  93                 const char *path,
  94                 const char *root,
  95                 unsigned chase_flags,
  96                 const char *open_flags,
  97                 FILE **ret_file,
  98                 char **ret_path);
  99
 100 int fflush_and_check(FILE *f);
 101 int fflush_sync_and_check(FILE *f);
 102
 103 int write_timestamp_file_atomic(const char *fn, usec_t n);
 104 int read_timestamp_file(const char *fn, usec_t *ret);
 105
 106 int fputs_with_space(FILE *f, const char *s, const char *separator, bool *space);
 107
 108 typedef enum ReadLineFlags {
 109         READ_LINE_ONLY_NUL  = 1 << 0,
 110         READ_LINE_IS_A_TTY  = 1 << 1,
 111         READ_LINE_NOT_A_TTY = 1 << 2,
 112 } ReadLineFlags;
 113
 114 int read_line_full(FILE *f, size_t limit, ReadLineFlags flags, char **ret);
 115
 116 static inline int read_line(FILE *f, size_t limit, char **ret) {
 117         return read_line_full(f, limit, 0, ret);
 118 }
 119
 120 static inline int read_nul_string(FILE *f, size_t limit, char **ret) {
 121         return read_line_full(f, limit, READ_LINE_ONLY_NUL, ret);
 122 }
 123
 124 int safe_fgetc(FILE *f, char *ret);
 125
 126 int warn_file_is_world_accessible(const char *filename, struct stat *st, const char *unit, unsigned line);
 127
 128 int rename_and_apply_smack_floor_label(const char *temp_path, const char *dest_path);