LXR linux/include/linux/device

   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)
  15int devcgroup_check_permission(short type, u32 major, u32 minor,
  16                               short access);
  17static 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
  40static 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
  60static inline int devcgroup_check_permission(short type, u32 major, u32 minor,
  61                               short access)
  62{ return 0; }
  63static inline int devcgroup_inode_permission(struct inode *inode, int mask)
  64{ return 0; }
  65static inline int devcgroup_inode_mknod(int mode, dev_t dev)
  66{ return 0; }
  67#endif
  68