248 строки
6.8 KiB
C
248 строки
6.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _LINUX_MNT_IDMAPPING_H
|
|
#define _LINUX_MNT_IDMAPPING_H
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/uidgid.h>
|
|
|
|
struct mnt_idmap;
|
|
struct user_namespace;
|
|
|
|
extern struct mnt_idmap nop_mnt_idmap;
|
|
extern struct user_namespace init_user_ns;
|
|
|
|
typedef struct {
|
|
uid_t val;
|
|
} vfsuid_t;
|
|
|
|
typedef struct {
|
|
gid_t val;
|
|
} vfsgid_t;
|
|
|
|
static_assert(sizeof(vfsuid_t) == sizeof(kuid_t));
|
|
static_assert(sizeof(vfsgid_t) == sizeof(kgid_t));
|
|
static_assert(offsetof(vfsuid_t, val) == offsetof(kuid_t, val));
|
|
static_assert(offsetof(vfsgid_t, val) == offsetof(kgid_t, val));
|
|
|
|
#ifdef CONFIG_MULTIUSER
|
|
static inline uid_t __vfsuid_val(vfsuid_t uid)
|
|
{
|
|
return uid.val;
|
|
}
|
|
|
|
static inline gid_t __vfsgid_val(vfsgid_t gid)
|
|
{
|
|
return gid.val;
|
|
}
|
|
#else
|
|
static inline uid_t __vfsuid_val(vfsuid_t uid)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline gid_t __vfsgid_val(vfsgid_t gid)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static inline bool vfsuid_valid(vfsuid_t uid)
|
|
{
|
|
return __vfsuid_val(uid) != (uid_t)-1;
|
|
}
|
|
|
|
static inline bool vfsgid_valid(vfsgid_t gid)
|
|
{
|
|
return __vfsgid_val(gid) != (gid_t)-1;
|
|
}
|
|
|
|
static inline bool vfsuid_eq(vfsuid_t left, vfsuid_t right)
|
|
{
|
|
return vfsuid_valid(left) && __vfsuid_val(left) == __vfsuid_val(right);
|
|
}
|
|
|
|
static inline bool vfsgid_eq(vfsgid_t left, vfsgid_t right)
|
|
{
|
|
return vfsgid_valid(left) && __vfsgid_val(left) == __vfsgid_val(right);
|
|
}
|
|
|
|
/**
|
|
* vfsuid_eq_kuid - check whether kuid and vfsuid have the same value
|
|
* @vfsuid: the vfsuid to compare
|
|
* @kuid: the kuid to compare
|
|
*
|
|
* Check whether @vfsuid and @kuid have the same values.
|
|
*
|
|
* Return: true if @vfsuid and @kuid have the same value, false if not.
|
|
* Comparison between two invalid uids returns false.
|
|
*/
|
|
static inline bool vfsuid_eq_kuid(vfsuid_t vfsuid, kuid_t kuid)
|
|
{
|
|
return vfsuid_valid(vfsuid) && __vfsuid_val(vfsuid) == __kuid_val(kuid);
|
|
}
|
|
|
|
/**
|
|
* vfsgid_eq_kgid - check whether kgid and vfsgid have the same value
|
|
* @vfsgid: the vfsgid to compare
|
|
* @kgid: the kgid to compare
|
|
*
|
|
* Check whether @vfsgid and @kgid have the same values.
|
|
*
|
|
* Return: true if @vfsgid and @kgid have the same value, false if not.
|
|
* Comparison between two invalid gids returns false.
|
|
*/
|
|
static inline bool vfsgid_eq_kgid(vfsgid_t vfsgid, kgid_t kgid)
|
|
{
|
|
return vfsgid_valid(vfsgid) && __vfsgid_val(vfsgid) == __kgid_val(kgid);
|
|
}
|
|
|
|
/*
|
|
* vfs{g,u}ids are created from k{g,u}ids.
|
|
* We don't allow them to be created from regular {u,g}id.
|
|
*/
|
|
#define VFSUIDT_INIT(val) (vfsuid_t){ __kuid_val(val) }
|
|
#define VFSGIDT_INIT(val) (vfsgid_t){ __kgid_val(val) }
|
|
|
|
#define INVALID_VFSUID VFSUIDT_INIT(INVALID_UID)
|
|
#define INVALID_VFSGID VFSGIDT_INIT(INVALID_GID)
|
|
|
|
/*
|
|
* Allow a vfs{g,u}id to be used as a k{g,u}id where we want to compare
|
|
* whether the mapped value is identical to value of a k{g,u}id.
|
|
*/
|
|
#define AS_KUIDT(val) (kuid_t){ __vfsuid_val(val) }
|
|
#define AS_KGIDT(val) (kgid_t){ __vfsgid_val(val) }
|
|
|
|
int vfsgid_in_group_p(vfsgid_t vfsgid);
|
|
|
|
vfsuid_t make_vfsuid(struct mnt_idmap *idmap,
|
|
struct user_namespace *fs_userns, kuid_t kuid);
|
|
|
|
vfsgid_t make_vfsgid(struct mnt_idmap *idmap,
|
|
struct user_namespace *fs_userns, kgid_t kgid);
|
|
|
|
kuid_t from_vfsuid(struct mnt_idmap *idmap,
|
|
struct user_namespace *fs_userns, vfsuid_t vfsuid);
|
|
|
|
kgid_t from_vfsgid(struct mnt_idmap *idmap,
|
|
struct user_namespace *fs_userns, vfsgid_t vfsgid);
|
|
|
|
/**
|
|
* vfsuid_has_fsmapping - check whether a vfsuid maps into the filesystem
|
|
* @idmap: the mount's idmapping
|
|
* @fs_userns: the filesystem's idmapping
|
|
* @vfsuid: vfsuid to be mapped
|
|
*
|
|
* Check whether @vfsuid has a mapping in the filesystem idmapping. Use this
|
|
* function to check whether the filesystem idmapping has a mapping for
|
|
* @vfsuid.
|
|
*
|
|
* Return: true if @vfsuid has a mapping in the filesystem, false if not.
|
|
*/
|
|
static inline bool vfsuid_has_fsmapping(struct mnt_idmap *idmap,
|
|
struct user_namespace *fs_userns,
|
|
vfsuid_t vfsuid)
|
|
{
|
|
return uid_valid(from_vfsuid(idmap, fs_userns, vfsuid));
|
|
}
|
|
|
|
static inline bool vfsuid_has_mapping(struct user_namespace *userns,
|
|
vfsuid_t vfsuid)
|
|
{
|
|
return from_kuid(userns, AS_KUIDT(vfsuid)) != (uid_t)-1;
|
|
}
|
|
|
|
/**
|
|
* vfsuid_into_kuid - convert vfsuid into kuid
|
|
* @vfsuid: the vfsuid to convert
|
|
*
|
|
* This can be used when a vfsuid is committed as a kuid.
|
|
*
|
|
* Return: a kuid with the value of @vfsuid
|
|
*/
|
|
static inline kuid_t vfsuid_into_kuid(vfsuid_t vfsuid)
|
|
{
|
|
return AS_KUIDT(vfsuid);
|
|
}
|
|
|
|
/**
|
|
* vfsgid_has_fsmapping - check whether a vfsgid maps into the filesystem
|
|
* @idmap: the mount's idmapping
|
|
* @fs_userns: the filesystem's idmapping
|
|
* @vfsgid: vfsgid to be mapped
|
|
*
|
|
* Check whether @vfsgid has a mapping in the filesystem idmapping. Use this
|
|
* function to check whether the filesystem idmapping has a mapping for
|
|
* @vfsgid.
|
|
*
|
|
* Return: true if @vfsgid has a mapping in the filesystem, false if not.
|
|
*/
|
|
static inline bool vfsgid_has_fsmapping(struct mnt_idmap *idmap,
|
|
struct user_namespace *fs_userns,
|
|
vfsgid_t vfsgid)
|
|
{
|
|
return gid_valid(from_vfsgid(idmap, fs_userns, vfsgid));
|
|
}
|
|
|
|
static inline bool vfsgid_has_mapping(struct user_namespace *userns,
|
|
vfsgid_t vfsgid)
|
|
{
|
|
return from_kgid(userns, AS_KGIDT(vfsgid)) != (gid_t)-1;
|
|
}
|
|
|
|
/**
|
|
* vfsgid_into_kgid - convert vfsgid into kgid
|
|
* @vfsgid: the vfsgid to convert
|
|
*
|
|
* This can be used when a vfsgid is committed as a kgid.
|
|
*
|
|
* Return: a kgid with the value of @vfsgid
|
|
*/
|
|
static inline kgid_t vfsgid_into_kgid(vfsgid_t vfsgid)
|
|
{
|
|
return AS_KGIDT(vfsgid);
|
|
}
|
|
|
|
/**
|
|
* mapped_fsuid - return caller's fsuid mapped according to an idmapping
|
|
* @idmap: the mount's idmapping
|
|
* @fs_userns: the filesystem's idmapping
|
|
*
|
|
* Use this helper to initialize a new vfs or filesystem object based on
|
|
* the caller's fsuid. A common example is initializing the i_uid field of
|
|
* a newly allocated inode triggered by a creation event such as mkdir or
|
|
* O_CREAT. Other examples include the allocation of quotas for a specific
|
|
* user.
|
|
*
|
|
* Return: the caller's current fsuid mapped up according to @idmap.
|
|
*/
|
|
static inline kuid_t mapped_fsuid(struct mnt_idmap *idmap,
|
|
struct user_namespace *fs_userns)
|
|
{
|
|
return from_vfsuid(idmap, fs_userns, VFSUIDT_INIT(current_fsuid()));
|
|
}
|
|
|
|
/**
|
|
* mapped_fsgid - return caller's fsgid mapped according to an idmapping
|
|
* @idmap: the mount's idmapping
|
|
* @fs_userns: the filesystem's idmapping
|
|
*
|
|
* Use this helper to initialize a new vfs or filesystem object based on
|
|
* the caller's fsgid. A common example is initializing the i_gid field of
|
|
* a newly allocated inode triggered by a creation event such as mkdir or
|
|
* O_CREAT. Other examples include the allocation of quotas for a specific
|
|
* user.
|
|
*
|
|
* Return: the caller's current fsgid mapped up according to @idmap.
|
|
*/
|
|
static inline kgid_t mapped_fsgid(struct mnt_idmap *idmap,
|
|
struct user_namespace *fs_userns)
|
|
{
|
|
return from_vfsgid(idmap, fs_userns, VFSGIDT_INIT(current_fsgid()));
|
|
}
|
|
|
|
bool check_fsmapping(const struct mnt_idmap *idmap,
|
|
const struct super_block *sb);
|
|
|
|
#endif /* _LINUX_MNT_IDMAPPING_H */
|