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);
17 static inline int devcgroup_inode_permission(struct inode *inode, int mask)
18 {
19 short type, access = 0;
20
21 if (likely(!inode->i_rdev))
22 return 0;
23
24 if (S_ISBLK(inode->i_mode))
25 type = DEVCG_DEV_BLOCK;
26 else if (S_ISCHR(inode->i_mode))
27 type = DEVCG_DEV_CHAR;
28 else
29 return 0;
30
31 if (mask & MAY_WRITE)
32 access |= DEVCG_ACC_WRITE;
33 if (mask & MAY_READ)
34 access |= DEVCG_ACC_READ;
35
36 return devcgroup_check_permission(type, imajor(inode), iminor(inode),
37 access);
38 }
39
40 static inline int devcgroup_inode_mknod(int mode, dev_t dev)
41 {
42 short type;
43
44 if (!S_ISBLK(mode) && !S_ISCHR(mode))
45 return 0;
46
47 if (S_ISCHR(mode) && dev == WHITEOUT_DEV)
48 return 0;
49
50 if (S_ISBLK(mode))
51 type = DEVCG_DEV_BLOCK;
52 else
53 type = DEVCG_DEV_CHAR;
54
55 return devcgroup_check_permission(type, MAJOR(dev), MINOR(dev),
56 DEVCG_ACC_MKNOD);
57 }
58
59 #else
60 static inline int devcgroup_check_permission(short type, u32 major, u32 minor,
61 short access)
62 { return 0; }
63 static inline int devcgroup_inode_permission(struct inode *inode, int mask)
64 { return 0; }
65 static inline int devcgroup_inode_mknod(int mode, dev_t dev)
66 { return 0; }
67 #endif
68
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