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#ifndef ZDTM_FS_H_
#define ZDTM_FS_H_
#ifndef _BSD_SOURCE
#define _BSD_SOURCE
#endif
#include <sys/types.h>
#include <sys/sysmacros.h>
#include <limits.h>
#define KDEV_MINORBITS 20
#define KDEV_MINORMASK ((1UL << KDEV_MINORBITS) - 1)
#define MKKDEV(ma, mi) (((ma) << KDEV_MINORBITS) | (mi))
static inline unsigned int kdev_major(unsigned int kdev)
{
return kdev >> KDEV_MINORBITS;
}
static inline unsigned int kdev_minor(unsigned int kdev)
{
return kdev & KDEV_MINORMASK;
}
static inline dev_t kdev_to_odev(unsigned int kdev)
{
/*
* New kernels encode devices in a new form.
* See kernel's fs/stat.c for details, there
* choose_32_64 helpers which are the key.
*/
unsigned major = kdev_major(kdev);
unsigned minor = kdev_minor(kdev);
return makedev(major, minor);
}
typedef struct {
int mnt_id;
int parent_mnt_id;
unsigned int s_dev;
char root[PATH_MAX];
char mountpoint[PATH_MAX];
char fsname[64];
} mnt_info_t;
extern mnt_info_t *mnt_info_alloc(void);
extern void mnt_info_free(mnt_info_t **m);
extern mnt_info_t *get_cwd_mnt_info(void);
/*
* get_cwd_check_perm is called to check that cwd is actually usable for a calling
* process.
*
* Example output of a stat command on a '/root' path shows file access bits:
* > stat /root
* File: ‘/root’
* ...
* Access: (0550/dr-xr-x---) Uid: ( 0/root) Gid: ( 0/root)
* ^- no 'x' bit for other
*
* Here we can see that '/root' dir (that often can be part of cwd path) does not
* allow non-root user and non-root group to list contents of this directory.
* Calling process matching 'other' access category may succeed getting cwd path, but will
* fail performing further filesystem operations based on this path with confusing errors.
*
* This function calls get_current_dir_name and explicitly checks that bit 'x' is enabled for
* a calling process and logs the error.
*
* If check passes, stores get_current_dir's result in *result and returns 0
* If check fails, stores 0 in *result and returns -1
*/
extern int get_cwd_check_perm(char **result);
#endif /* ZDTM_FS_H_ */
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