1 /* SPDX-License-Identifier: GPL-2.0 */
2 #include <linux/fs.h>
3
4 #define DEVCG_ACC_MKNOD 1
5 #define DEVCG_ACC_READ 2
6 #define DEVCG_ACC_WRITE 4
7 #define DEVCG_ACC_MASK (DEVCG_ACC_MKNOD | DEVCG_ACC_READ | DEVCG_ACC_WRITE)
8
9 #define DEVCG_DEV_BLOCK 1
10 #define DEVCG_DEV_CHAR 2
11 #define DEVCG_DEV_ALL 4 /* this represents all devices */
12
13
14 #if defined(CONFIG_CGROUP_DEVICE) || defined(CONFIG_CGROUP_BPF)
15 int devcgroup_check_permission(short type, u32 major, u32 minor,
16 short access);
devcgroup_inode_permission(struct inode * inode,int mask)17 static inline int devcgroup_inode_permission(struct inode *inode, int mask)
18 {
19 short type, access = 0;
20
21 if (likely(!S_ISBLK(inode->i_mode) && !S_ISCHR(inode->i_mode)))
22 return 0;
23
24 if (likely(!inode->i_rdev))
25 return 0;
26
27 if (S_ISBLK(inode->i_mode))
28 type = DEVCG_DEV_BLOCK;
29 else /* S_ISCHR by the test above */
30 type = DEVCG_DEV_CHAR;
31
32 if (mask & MAY_WRITE)
33 access |= DEVCG_ACC_WRITE;
34 if (mask & MAY_READ)
35 access |= DEVCG_ACC_READ;
36
37 return devcgroup_check_permission(type, imajor(inode), iminor(inode),
38 access);
39 }
40
devcgroup_inode_mknod(int mode,dev_t dev)41 static inline int devcgroup_inode_mknod(int mode, dev_t dev)
42 {
43 short type;
44
45 if (!S_ISBLK(mode) && !S_ISCHR(mode))
46 return 0;
47
48 if (S_ISCHR(mode) && dev == WHITEOUT_DEV)
49 return 0;
50
51 if (S_ISBLK(mode))
52 type = DEVCG_DEV_BLOCK;
53 else
54 type = DEVCG_DEV_CHAR;
55
56 return devcgroup_check_permission(type, MAJOR(dev), MINOR(dev),
57 DEVCG_ACC_MKNOD);
58 }
59
60 #else
devcgroup_check_permission(short type,u32 major,u32 minor,short access)61 static inline int devcgroup_check_permission(short type, u32 major, u32 minor,
62 short access)
63 { return 0; }
devcgroup_inode_permission(struct inode * inode,int mask)64 static inline int devcgroup_inode_permission(struct inode *inode, int mask)
65 { return 0; }
devcgroup_inode_mknod(int mode,dev_t dev)66 static inline int devcgroup_inode_mknod(int mode, dev_t dev)
67 { return 0; }
68 #endif
69