device_cgroup.h
/* SPDX-License-Identifier: GPL-2.0 */
#include <linux/fs.h>
#define DEVCG_ACC_MKNOD 1
#define DEVCG_ACC_READ 2
#define DEVCG_ACC_WRITE 4
#define DEVCG_ACC_MASK (DEVCG_ACC_MKNOD | DEVCG_ACC_READ | DEVCG_ACC_WRITE)
#define DEVCG_DEV_BLOCK 1
#define DEVCG_DEV_CHAR 2
#define DEVCG_DEV_ALL 4 /* this represents all devices */
#if defined(CONFIG_CGROUP_DEVICE) || defined(CONFIG_CGROUP_BPF)
int devcgroup_check_permission(short type, u32 major, u32 minor,
short access);
static inline int devcgroup_inode_permission(struct inode *inode, int mask)
{
short type, access = 0;
if (likely(!inode->i_rdev))
return 0;
if (S_ISBLK(inode->i_mode))
type = DEVCG_DEV_BLOCK;
else if (S_ISCHR(inode->i_mode))
type = DEVCG_DEV_CHAR;
else
return 0;
if (mask & MAY_WRITE)
access |= DEVCG_ACC_WRITE;
if (mask & MAY_READ)
access |= DEVCG_ACC_READ;
return devcgroup_check_permission(type, imajor(inode), iminor(inode),
access);
}
static inline int devcgroup_inode_mknod(int mode, dev_t dev)
{
short type;
if (!S_ISBLK(mode) && !S_ISCHR(mode))
return 0;
if (S_ISCHR(mode) && dev == WHITEOUT_DEV)
return 0;
if (S_ISBLK(mode))
type = DEVCG_DEV_BLOCK;
else
type = DEVCG_DEV_CHAR;
return devcgroup_check_permission(type, MAJOR(dev), MINOR(dev),
DEVCG_ACC_MKNOD);
}
#else
static inline int devcgroup_check_permission(short type, u32 major, u32 minor,
short access)
{ return 0; }
static inline int devcgroup_inode_permission(struct inode *inode, int mask)
{ return 0; }
static inline int devcgroup_inode_mknod(int mode, dev_t dev)
{ return 0; }
#endif