include/linux/device_cgroup.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 #include <linux/fs.h>
0003
0004 #define DEVCG_ACC_MKNOD 1
0005 #define DEVCG_ACC_READ  2
0006 #define DEVCG_ACC_WRITE 4
0007 #define DEVCG_ACC_MASK (DEVCG_ACC_MKNOD | DEVCG_ACC_READ | DEVCG_ACC_WRITE)
0008
0009 #define DEVCG_DEV_BLOCK 1
0010 #define DEVCG_DEV_CHAR  2
0011 #define DEVCG_DEV_ALL   4  /* this represents all devices */
0012
0013
0014 #if defined(CONFIG_CGROUP_DEVICE) || defined(CONFIG_CGROUP_BPF)
0015 int devcgroup_check_permission(short type, u32 major, u32 minor,
0016                    short access);
0017 static inline int devcgroup_inode_permission(struct inode *inode, int mask)
0018 {
0019     short type, access = 0;
0020
0021     if (likely(!inode->i_rdev))
0022         return 0;
0023
0024     if (S_ISBLK(inode->i_mode))
0025         type = DEVCG_DEV_BLOCK;
0026     else if (S_ISCHR(inode->i_mode))
0027         type = DEVCG_DEV_CHAR;
0028     else
0029         return 0;
0030
0031     if (mask & MAY_WRITE)
0032         access |= DEVCG_ACC_WRITE;
0033     if (mask & MAY_READ)
0034         access |= DEVCG_ACC_READ;
0035
0036     return devcgroup_check_permission(type, imajor(inode), iminor(inode),
0037                       access);
0038 }
0039
0040 static inline int devcgroup_inode_mknod(int mode, dev_t dev)
0041 {
0042     short type;
0043
0044     if (!S_ISBLK(mode) && !S_ISCHR(mode))
0045         return 0;
0046
0047     if (S_ISCHR(mode) && dev == WHITEOUT_DEV)
0048         return 0;
0049
0050     if (S_ISBLK(mode))
0051         type = DEVCG_DEV_BLOCK;
0052     else
0053         type = DEVCG_DEV_CHAR;
0054
0055     return devcgroup_check_permission(type, MAJOR(dev), MINOR(dev),
0056                       DEVCG_ACC_MKNOD);
0057 }
0058
0059 #else
0060 static inline int devcgroup_check_permission(short type, u32 major, u32 minor,
0061                    short access)
0062 { return 0; }
0063 static inline int devcgroup_inode_permission(struct inode *inode, int mask)
0064 { return 0; }
0065 static inline int devcgroup_inode_mknod(int mode, dev_t dev)
0066 { return 0; }
0067 #endif