Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/* SPDX-License-Identifier: GPL-2.0 */
2#include <linux/fs.h>
3#include <linux/bpf-cgroup.h>
4
5#define DEVCG_ACC_MKNOD 1
6#define DEVCG_ACC_READ 2
7#define DEVCG_ACC_WRITE 4
8#define DEVCG_ACC_MASK (DEVCG_ACC_MKNOD | DEVCG_ACC_READ | DEVCG_ACC_WRITE)
9
10#define DEVCG_DEV_BLOCK 1
11#define DEVCG_DEV_CHAR 2
12#define DEVCG_DEV_ALL 4 /* this represents all devices */
13
14#ifdef CONFIG_CGROUP_DEVICE
15extern int __devcgroup_check_permission(short type, u32 major, u32 minor,
16 short access);
17#else
18static inline int __devcgroup_check_permission(short type, u32 major, u32 minor,
19 short access)
20{ return 0; }
21#endif
22
23#if defined(CONFIG_CGROUP_DEVICE) || defined(CONFIG_CGROUP_BPF)
24static inline int devcgroup_check_permission(short type, u32 major, u32 minor,
25 short access)
26{
27 int rc = BPF_CGROUP_RUN_PROG_DEVICE_CGROUP(type, major, minor, access);
28
29 if (rc)
30 return -EPERM;
31
32 return __devcgroup_check_permission(type, major, minor, access);
33}
34
35static inline int devcgroup_inode_permission(struct inode *inode, int mask)
36{
37 short type, access = 0;
38
39 if (likely(!inode->i_rdev))
40 return 0;
41
42 if (S_ISBLK(inode->i_mode))
43 type = DEVCG_DEV_BLOCK;
44 else if (S_ISCHR(inode->i_mode))
45 type = DEVCG_DEV_CHAR;
46 else
47 return 0;
48
49 if (mask & MAY_WRITE)
50 access |= DEVCG_ACC_WRITE;
51 if (mask & MAY_READ)
52 access |= DEVCG_ACC_READ;
53
54 return devcgroup_check_permission(type, imajor(inode), iminor(inode),
55 access);
56}
57
58static inline int devcgroup_inode_mknod(int mode, dev_t dev)
59{
60 short type;
61
62 if (!S_ISBLK(mode) && !S_ISCHR(mode))
63 return 0;
64
65 if (S_ISBLK(mode))
66 type = DEVCG_DEV_BLOCK;
67 else
68 type = DEVCG_DEV_CHAR;
69
70 return devcgroup_check_permission(type, MAJOR(dev), MINOR(dev),
71 DEVCG_ACC_MKNOD);
72}
73
74#else
75static inline int devcgroup_inode_permission(struct inode *inode, int mask)
76{ return 0; }
77static inline int devcgroup_inode_mknod(int mode, dev_t dev)
78{ return 0; }
79#endif