src/basic/fileio.h

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2 #pragma once
   3
   4 #include "forward.h"
   5
   6 #define LONG_LINE_MAX (1U*1024U*1024U)
   7
   8 typedef enum {
   9         WRITE_STRING_FILE_CREATE                     = 1 << 0,
  10         WRITE_STRING_FILE_TRUNCATE                   = 1 << 1,
  11         WRITE_STRING_FILE_ATOMIC                     = 1 << 2,
  12         WRITE_STRING_FILE_AVOID_NEWLINE              = 1 << 3,
  13         WRITE_STRING_FILE_VERIFY_ON_FAILURE          = 1 << 4,
  14         WRITE_STRING_FILE_VERIFY_IGNORE_NEWLINE      = 1 << 5,
  15         WRITE_STRING_FILE_SYNC                       = 1 << 6,
  16         WRITE_STRING_FILE_DISABLE_BUFFER             = 1 << 7,
  17         WRITE_STRING_FILE_NOFOLLOW                   = 1 << 8,
  18         WRITE_STRING_FILE_MKDIR_0755                 = 1 << 9,
  19         WRITE_STRING_FILE_MODE_0600                  = 1 << 10,
  20         WRITE_STRING_FILE_MODE_0444                  = 1 << 11,
  21         WRITE_STRING_FILE_SUPPRESS_REDUNDANT_VIRTUAL = 1 << 12,
  22         WRITE_STRING_FILE_LABEL                      = 1 << 13,
  23         WRITE_STRING_FILE_OPEN_NONBLOCKING           = 1 << 14,
  24 } WriteStringFileFlags;
  25
  26 typedef enum {
  27         READ_FULL_FILE_SECURE              = 1 << 0, /* erase any buffers we employ internally, after use */
  28         READ_FULL_FILE_UNBASE64            = 1 << 1, /* base64 decode what we read */
  29         READ_FULL_FILE_UNHEX               = 1 << 2, /* hex decode what we read */
  30         READ_FULL_FILE_WARN_WORLD_READABLE = 1 << 3, /* if regular file, log at LOG_WARNING level if access mode above 0700 */
  31         READ_FULL_FILE_CONNECT_SOCKET      = 1 << 4, /* if socket inode, connect to it and read off it */
  32         READ_FULL_FILE_FAIL_WHEN_LARGER    = 1 << 5, /* fail loading if file is larger than specified size */
  33 } ReadFullFileFlags;
  34
  35 int fdopen_unlocked(int fd, const char *options, FILE **ret);
  36 int take_fdopen_unlocked(int *fd, const char *options, FILE **ret);
  37 FILE* take_fdopen(int *fd, const char *options);
  38 DIR* take_fdopendir(int *dfd);
  39 FILE* open_memstream_unlocked(char **ptr, size_t *sizeloc);
  40 FILE* fmemopen_unlocked(void *buf, size_t size, const char *mode);
  41
  42 int write_string_stream_full(FILE *f, const char *line, WriteStringFileFlags flags, const struct timespec *ts);
  43 static inline int write_string_stream(FILE *f, const char *line, WriteStringFileFlags flags) {
  44         return write_string_stream_full(f, line, flags, NULL);
  45 }
  46
  47 int write_string_file_full(int dir_fd, const char *fn, const char *line, WriteStringFileFlags flags, const struct timespec *ts, const char *label_fn);
  48 static inline int write_string_file_at(int dir_fd, const char *fn, const char *line, WriteStringFileFlags flags) {
  49         return write_string_file_full(dir_fd, fn, line, flags, NULL, NULL);
  50 }
  51 static inline int write_string_file_fd(int dir_fd, const char *line, WriteStringFileFlags flags) {
  52         return write_string_file_at(dir_fd, NULL, line, flags);
  53 }
  54 static inline int write_string_file(const char *fn, const char *line, WriteStringFileFlags flags) {
  55         return write_string_file_at(AT_FDCWD, fn, line, flags);
  56 }
  57 int write_string_filef(const char *fn, WriteStringFileFlags flags, const char *format, ...) _printf_(3, 4);
  58
  59 int write_base64_file_at(int dir_fd, const char *fn, const struct iovec *data, WriteStringFileFlags flags);
  60
  61 int read_one_line_file_at(int dir_fd, const char *filename, char **ret);
  62 static inline int read_one_line_file(const char *filename, char **ret) {
  63         return read_one_line_file_at(AT_FDCWD, filename, ret);
  64 }
  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_at(int dir_fd, const char *filename, char **ret_contents, size_t *ret_size) {
  67         return read_full_file_full(dir_fd, filename, UINT64_MAX, SIZE_MAX, 0, NULL, ret_contents, ret_size);
  68 }
  69 static inline int read_full_file(const char *filename, char **ret_contents, size_t *ret_size) {
  70         return read_full_file_full(AT_FDCWD, filename, UINT64_MAX, SIZE_MAX, 0, NULL, ret_contents, ret_size);
  71 }
  72
  73 int read_virtual_file_at(int dir_fd, const char *filename, size_t max_size, char **ret_contents, size_t *ret_size);
  74 static inline int read_virtual_file_fd(int fd, size_t max_size, char **ret_contents, size_t *ret_size) {
  75         return read_virtual_file_at(fd, NULL, max_size, ret_contents, ret_size);
  76 }
  77 static inline int read_virtual_file(const char *filename, size_t max_size, char **ret_contents, size_t *ret_size) {
  78         return read_virtual_file_at(AT_FDCWD, filename, max_size, ret_contents, ret_size);
  79 }
  80 static inline int read_full_virtual_file(const char *filename, char **ret_contents, size_t *ret_size) {
  81         return read_virtual_file(filename, SIZE_MAX, ret_contents, ret_size);
  82 }
  83
  84 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);
  85 static inline int read_full_stream(FILE *f, char **ret_contents, size_t *ret_size) {
  86         return read_full_stream_full(f, NULL, UINT64_MAX, SIZE_MAX, 0, ret_contents, ret_size);
  87 }
  88
  89 int verify_file_at(int dir_fd, const char *fn, const char *blob, bool accept_extra_nl);
  90
  91 int script_get_shebang_interpreter(const char *path, char **ret);
  92
  93 int get_proc_field(const char *path, const char *key, char **ret);
  94
  95 DIR* xopendirat(int dir_fd, const char *name, int flags);
  96
  97 typedef enum XfopenFlags {
  98         XFOPEN_UNLOCKED = 1 << 0, /* call __fsetlocking(FSETLOCKING_BYCALLER) after opened */
  99         XFOPEN_SOCKET   = 1 << 1, /* also try to open unix socket */
 100 } XfopenFlags;
 101
 102 int xfopenat_full(
 103                 int dir_fd,
 104                 const char *path,
 105                 const char *mode,
 106                 int open_flags,
 107                 XfopenFlags flags,
 108                 const char *bind_name,
 109                 FILE **ret);
 110 static inline int xfopenat(int dir_fd, const char *path, const char *mode, int open_flags, FILE **ret) {
 111         return xfopenat_full(dir_fd, path, mode, open_flags, 0, NULL, ret);
 112 }
 113 static inline int fopen_unlocked_at(int dir_fd, const char *path, const char *mode, int open_flags, FILE **ret) {
 114         return xfopenat_full(dir_fd, path, mode, open_flags, XFOPEN_UNLOCKED, NULL, ret);
 115 }
 116 static inline int fopen_unlocked(const char *path, const char *mode, FILE **ret) {
 117         return fopen_unlocked_at(AT_FDCWD, path, mode, 0, ret);
 118 }
 119
 120 int fdopen_independent(int fd, const char *mode, FILE **ret);
 121
 122 int search_and_open(const char *path, int mode, const char *root, char **search, int *ret_fd, char **ret_path);
 123 static inline int search_and_access(const char *path, int mode, const char *root, char**search, char **ret_path) {
 124         return search_and_open(path, mode, root, search, NULL, ret_path);
 125 }
 126 int search_and_fopen(const char *path, const char *mode, const char *root, const char **search, FILE **ret_file, char **ret_path);
 127 int search_and_fopen_nulstr(const char *path, const char *mode, const char *root, const char *search, FILE **ret_file, char **ret_path);
 128
 129 int fflush_and_check(FILE *f);
 130 int fflush_sync_and_check(FILE *f);
 131
 132 int write_timestamp_file_atomic(const char *fn, usec_t n);
 133 int read_timestamp_file(const char *fn, usec_t *ret);
 134
 135 int fputs_with_separator(FILE *f, const char *s, const char *separator, bool *space);
 136 int fputs_with_newline(FILE *f, const char *s);
 137
 138 typedef enum ReadLineFlags {
 139         READ_LINE_ONLY_NUL  = 1 << 0,
 140         READ_LINE_IS_A_TTY  = 1 << 1,
 141         READ_LINE_NOT_A_TTY = 1 << 2,
 142 } ReadLineFlags;
 143
 144 int read_line_full(FILE *f, size_t limit, ReadLineFlags flags, char **ret);
 145 static inline int read_line(FILE *f, size_t limit, char **ret) {
 146         return read_line_full(f, limit, 0, ret);
 147 }
 148 static inline int read_nul_string(FILE *f, size_t limit, char **ret) {
 149         return read_line_full(f, limit, READ_LINE_ONLY_NUL, ret);
 150 }
 151
 152 int read_stripped_line(FILE *f, size_t limit, char **ret);
 153
 154 static inline bool file_offset_beyond_memory_size(off_t x) {
 155         if (x < 0) /* off_t is signed, filter that out */
 156                 return false;
 157         return (uint64_t) x > (uint64_t) SIZE_MAX;
 158 }
 159
 160 int safe_fgetc(FILE *f, char *ret);
 161
 162 int warn_file_is_world_accessible(const char *filename, struct stat *st, const char *unit, unsigned line);
 163
 164 int fopen_mode_to_flags(const char *mode);