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, major: imajor(inode), minor: 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 | |