include/linux/kernel_read_file.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _LINUX_KERNEL_READ_FILE_H
   3 #define _LINUX_KERNEL_READ_FILE_H
   4
   5 #include <linux/file.h>
   6 #include <linux/types.h>
   7
   8 /* This is a list of *what* is being read, not *how* nor *where*. */
   9 #define __kernel_read_file_id(id) \
  10         id(UNKNOWN, unknown)            \
  11         id(FIRMWARE, firmware)          \
  12         id(MODULE, kernel-module)               \
  13         id(KEXEC_IMAGE, kexec-image)            \
  14         id(KEXEC_INITRAMFS, kexec-initramfs)    \
  15         id(POLICY, security-policy)             \
  16         id(X509_CERTIFICATE, x509-certificate)  \
  17         id(MAX_ID, )
  18
  19 #define __fid_enumify(ENUM, dummy) READING_ ## ENUM,
  20 #define __fid_stringify(dummy, str) #str,
  21
  22 enum kernel_read_file_id {
  23         __kernel_read_file_id(__fid_enumify)
  24 };
  25
  26 static const char * const kernel_read_file_str[] = {
  27         __kernel_read_file_id(__fid_stringify)
  28 };
  29
  30 static inline const char *kernel_read_file_id_str(enum kernel_read_file_id id)
  31 {
  32         if ((unsigned int)id >= READING_MAX_ID)
  33                 return kernel_read_file_str[READING_UNKNOWN];
  34
  35         return kernel_read_file_str[id];
  36 }
  37
  38 ssize_t kernel_read_file(struct file *file, loff_t offset,
  39                          void **buf, size_t buf_size,
  40                          size_t *file_size,
  41                          enum kernel_read_file_id id);
  42 ssize_t kernel_read_file_from_path(const char *path, loff_t offset,
  43                                    void **buf, size_t buf_size,
  44                                    size_t *file_size,
  45                                    enum kernel_read_file_id id);
  46 ssize_t kernel_read_file_from_path_initns(const char *path, loff_t offset,
  47                                           void **buf, size_t buf_size,
  48                                           size_t *file_size,
  49                                           enum kernel_read_file_id id);
  50 ssize_t kernel_read_file_from_fd(int fd, loff_t offset,
  51                                  void **buf, size_t buf_size,
  52                                  size_t *file_size,
  53                                  enum kernel_read_file_id id);
  54
  55 #endif /* _LINUX_KERNEL_READ_FILE_H */