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 15 extern int __devcgroup_check_permission(short type, u32 major, u32 minor, 16 short access); 17 #else 18 static 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) 24 static 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 35 static 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 58 static 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 75 static inline int devcgroup_inode_permission(struct inode *inode, int mask) 76 { return 0; } 77 static inline int devcgroup_inode_mknod(int mode, dev_t dev) 78 { return 0; } 79 #endif 80