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 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_inode_permission(struct inode *inode, int mask) 25 { 26 short type, access = 0; 27 28 if (likely(!inode->i_rdev)) 29 return 0; 30 31 if (S_ISBLK(inode->i_mode)) 32 type = DEVCG_DEV_BLOCK; 33 else if (S_ISCHR(inode->i_mode)) 34 type = DEVCG_DEV_CHAR; 35 else 36 return 0; 37 38 if (mask & MAY_WRITE) 39 access |= DEVCG_ACC_WRITE; 40 if (mask & MAY_READ) 41 access |= DEVCG_ACC_READ; 42 43 return devcgroup_check_permission(type, imajor(inode), iminor(inode), 44 access); 45 } 46 47 static inline int devcgroup_inode_mknod(int mode, dev_t dev) 48 { 49 short type; 50 51 if (!S_ISBLK(mode) && !S_ISCHR(mode)) 52 return 0; 53 54 if (S_ISBLK(mode)) 55 type = DEVCG_DEV_BLOCK; 56 else 57 type = DEVCG_DEV_CHAR; 58 59 return devcgroup_check_permission(type, MAJOR(dev), MINOR(dev), 60 DEVCG_ACC_MKNOD); 61 } 62 63 #else 64 static inline int devcgroup_inode_permission(struct inode *inode, int mask) 65 { return 0; } 66 static inline int devcgroup_inode_mknod(int mode, dev_t dev) 67 { return 0; } 68 #endif 69