diff options
Diffstat (limited to 'vendor/github.com/opencontainers/runc/libcontainer/devices/device.go')
-rw-r--r-- | vendor/github.com/opencontainers/runc/libcontainer/devices/device.go | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/vendor/github.com/opencontainers/runc/libcontainer/devices/device.go b/vendor/github.com/opencontainers/runc/libcontainer/devices/device.go new file mode 100644 index 000000000..3eb73cc7c --- /dev/null +++ b/vendor/github.com/opencontainers/runc/libcontainer/devices/device.go @@ -0,0 +1,170 @@ +package devices + +import ( + "fmt" + "os" + "strconv" +) + +const ( + Wildcard = -1 +) + +type Device struct { + Rule + + // Path to the device. + Path string `json:"path"` + + // FileMode permission bits for the device. + FileMode os.FileMode `json:"file_mode"` + + // Uid of the device. + Uid uint32 `json:"uid"` + + // Gid of the device. + Gid uint32 `json:"gid"` +} + +// Permissions is a cgroupv1-style string to represent device access. It +// has to be a string for backward compatibility reasons, hence why it has +// methods to do set operations. +type Permissions string + +const ( + deviceRead uint = (1 << iota) + deviceWrite + deviceMknod +) + +func (p Permissions) toSet() uint { + var set uint + for _, perm := range p { + switch perm { + case 'r': + set |= deviceRead + case 'w': + set |= deviceWrite + case 'm': + set |= deviceMknod + } + } + return set +} + +func fromSet(set uint) Permissions { + var perm string + if set&deviceRead == deviceRead { + perm += "r" + } + if set&deviceWrite == deviceWrite { + perm += "w" + } + if set&deviceMknod == deviceMknod { + perm += "m" + } + return Permissions(perm) +} + +// Union returns the union of the two sets of Permissions. +func (p Permissions) Union(o Permissions) Permissions { + lhs := p.toSet() + rhs := o.toSet() + return fromSet(lhs | rhs) +} + +// Difference returns the set difference of the two sets of Permissions. +// In set notation, A.Difference(B) gives you A\B. +func (p Permissions) Difference(o Permissions) Permissions { + lhs := p.toSet() + rhs := o.toSet() + return fromSet(lhs &^ rhs) +} + +// Intersection computes the intersection of the two sets of Permissions. +func (p Permissions) Intersection(o Permissions) Permissions { + lhs := p.toSet() + rhs := o.toSet() + return fromSet(lhs & rhs) +} + +// IsEmpty returns whether the set of permissions in a Permissions is +// empty. +func (p Permissions) IsEmpty() bool { + return p == Permissions("") +} + +// IsValid returns whether the set of permissions is a subset of valid +// permissions (namely, {r,w,m}). +func (p Permissions) IsValid() bool { + return p == fromSet(p.toSet()) +} + +type Type rune + +const ( + WildcardDevice Type = 'a' + BlockDevice Type = 'b' + CharDevice Type = 'c' // or 'u' + FifoDevice Type = 'p' +) + +func (t Type) IsValid() bool { + switch t { + case WildcardDevice, BlockDevice, CharDevice, FifoDevice: + return true + default: + return false + } +} + +func (t Type) CanMknod() bool { + switch t { + case BlockDevice, CharDevice, FifoDevice: + return true + default: + return false + } +} + +func (t Type) CanCgroup() bool { + switch t { + case WildcardDevice, BlockDevice, CharDevice: + return true + default: + return false + } +} + +type Rule struct { + // Type of device ('c' for char, 'b' for block). If set to 'a', this rule + // acts as a wildcard and all fields other than Allow are ignored. + Type Type `json:"type"` + + // Major is the device's major number. + Major int64 `json:"major"` + + // Minor is the device's minor number. + Minor int64 `json:"minor"` + + // Permissions is the set of permissions that this rule applies to (in the + // cgroupv1 format -- any combination of "rwm"). + Permissions Permissions `json:"permissions"` + + // Allow specifies whether this rule is allowed. + Allow bool `json:"allow"` +} + +func (d *Rule) CgroupString() string { + var ( + major = strconv.FormatInt(d.Major, 10) + minor = strconv.FormatInt(d.Minor, 10) + ) + if d.Major == Wildcard { + major = "*" + } + if d.Minor == Wildcard { + minor = "*" + } + return fmt.Sprintf("%c %s:%s %s", d.Type, major, minor, d.Permissions) +} |