src/lxc/file_utils.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #ifndef __LXC_FILE_UTILS_H
   4 #define __LXC_FILE_UTILS_H
   5
   6 #include <fcntl.h>
   7 #include <stdbool.h>
   8 #include <stdio.h>
   9 #include <sys/stat.h>
  10 #include <sys/types.h>
  11 #include <sys/uio.h>
  12 #include <sys/vfs.h>
  13 #include <unistd.h>
  14
  15 #include "compiler.h"
  16 #include "syscall_wrappers.h"
  17
  18 /* read and write whole files */
  19 __hidden extern int lxc_write_to_file(const char *filename, const void *buf, size_t count,
  20                                       bool add_newline, mode_t mode) __access_r(2, 3);
  21
  22 __hidden extern int lxc_readat(int dirfd, const char *filename, void *buf, size_t count)
  23     __access_w(3, 4);
  24
  25 __hidden extern int lxc_writeat(int dirfd, const char *filename, const void *buf, size_t count)
  26     __access_r(3, 4);
  27
  28 __hidden extern int lxc_write_openat(const char *dir, const char *filename, const void *buf,
  29                                      size_t count) __access_r(3, 4);
  30
  31 __hidden extern int lxc_read_from_file(const char *filename, void *buf, size_t count)
  32     __access_w(2, 3);
  33
  34 /* send and receive buffers completely */
  35 __hidden extern ssize_t lxc_write_nointr(int fd, const void *buf, size_t count) __access_r(2, 3);
  36
  37 __hidden extern ssize_t lxc_pwrite_nointr(int fd, const void *buf, size_t count, off_t offset)
  38     __access_r(2, 3);
  39
  40 __hidden extern ssize_t lxc_send_nointr(int sockfd, void *buf, size_t len, int flags)
  41     __access_r(2, 3);
  42
  43 __hidden extern ssize_t lxc_read_nointr(int fd, void *buf, size_t count) __access_w(2, 3);
  44
  45 __hidden extern ssize_t lxc_read_nointr_expect(int fd, void *buf, size_t count,
  46                                                const void *expected_buf) __access_w(2, 3);
  47
  48 __hidden extern ssize_t lxc_read_file_expect(const char *path, void *buf, size_t count,
  49                                              const void *expected_buf) __access_w(2, 3);
  50
  51 __hidden extern ssize_t lxc_recv_nointr(int sockfd, void *buf, size_t len, int flags)
  52     __access_w(2, 3);
  53
  54 __hidden extern ssize_t lxc_recvmsg_nointr_iov(int sockfd, struct iovec *iov, size_t iovlen,
  55                                                int flags);
  56
  57 __hidden extern bool file_exists(const char *f);
  58 __hidden extern int print_to_file(const char *file, const char *content);
  59 __hidden extern int is_dir(const char *path);
  60 __hidden extern int lxc_count_file_lines(const char *fn);
  61 __hidden extern int lxc_make_tmpfile(char *template, bool rm);
  62
  63 /* __typeof__ should be safe to use with all compilers. */
  64 typedef __typeof__(((struct statfs *)NULL)->f_type) fs_type_magic;
  65 __hidden extern bool has_fs_type(const char *path, fs_type_magic magic_val);
  66 __hidden extern bool fhas_fs_type(int fd, fs_type_magic magic_val);
  67 __hidden extern bool is_fs_type(const struct statfs *fs, fs_type_magic magic_val);
  68 __hidden extern FILE *fopen_cloexec(const char *path, const char *mode);
  69 __hidden extern ssize_t lxc_sendfile_nointr(int out_fd, int in_fd, off_t *offset, size_t count);
  70 __hidden extern char *file_to_buf(const char *path, size_t *length);
  71 __hidden extern int fd_to_buf(int fd, char **buf, size_t *length);
  72 __hidden extern ssize_t __fd_to_fd(int from, int to);
  73 static inline int fd_to_fd(int from, int to)
  74 {
  75         return __fd_to_fd(from, to) >= 0;
  76 }
  77 __hidden extern int fd_cloexec(int fd, bool cloexec);
  78 __hidden extern int lxc_open_dirfd(const char *dir);
  79 __hidden extern FILE *fdopen_cached(int fd, const char *mode, void **caller_freed_buffer);
  80 __hidden extern FILE *fdopen_at(int dfd, const char *path, const char *mode,
  81                                 unsigned int o_flags,
  82                                 unsigned int resolve_flags);
  83 __hidden extern FILE *fopen_cached(const char *path, const char *mode, void **caller_freed_buffer);
  84 __hidden extern int timens_offset_write(clockid_t clk_id, int64_t s_offset, int64_t ns_offset);
  85 __hidden extern bool exists_dir_at(int dir_fd, const char *path);
  86 __hidden extern bool exists_file_at(int dir_fd, const char *path);
  87 __hidden extern int open_at(int dfd, const char *path, unsigned int o_flags,
  88                             unsigned int resolve_flags, mode_t mode);
  89 static inline int open_beneath(int dfd, const char *path, unsigned int flags)
  90 {
  91         return open_at(dfd, path, flags, PROTECT_LOOKUP_BENEATH, 0);
  92 }
  93 __hidden int fd_make_nonblocking(int fd);
  94 __hidden extern char *read_file_at(int dfd, const char *fnam,
  95                                    unsigned int o_flags,
  96                                    unsigned resolve_flags);
  97 __hidden extern ssize_t lxc_read_try_buf_at(int dfd, const char *path,
  98                                             void *buf, size_t count);
  99
 100 #endif /* __LXC_FILE_UTILS_H */