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|
package landlock
import (
"strings"
"syscall"
"unsafe"
"hakurei.app/ext"
)
// include/uapi/linux/landlock.h
const (
LANDLOCK_CREATE_RULESET_VERSION = 1 << iota
)
// AccessFS is bitmask of handled filesystem actions.
type AccessFS uint64
const (
LANDLOCK_ACCESS_FS_EXECUTE AccessFS = 1 << iota
LANDLOCK_ACCESS_FS_WRITE_FILE
LANDLOCK_ACCESS_FS_READ_FILE
LANDLOCK_ACCESS_FS_READ_DIR
LANDLOCK_ACCESS_FS_REMOVE_DIR
LANDLOCK_ACCESS_FS_REMOVE_FILE
LANDLOCK_ACCESS_FS_MAKE_CHAR
LANDLOCK_ACCESS_FS_MAKE_DIR
LANDLOCK_ACCESS_FS_MAKE_REG
LANDLOCK_ACCESS_FS_MAKE_SOCK
LANDLOCK_ACCESS_FS_MAKE_FIFO
LANDLOCK_ACCESS_FS_MAKE_BLOCK
LANDLOCK_ACCESS_FS_MAKE_SYM
LANDLOCK_ACCESS_FS_REFER
LANDLOCK_ACCESS_FS_TRUNCATE
LANDLOCK_ACCESS_FS_IOCTL_DEV
_LANDLOCK_ACCESS_FS_DELIM
)
// String returns a space-separated string of [AccessFS] flags.
func (f AccessFS) String() string {
switch f {
case LANDLOCK_ACCESS_FS_EXECUTE:
return "execute"
case LANDLOCK_ACCESS_FS_WRITE_FILE:
return "write_file"
case LANDLOCK_ACCESS_FS_READ_FILE:
return "read_file"
case LANDLOCK_ACCESS_FS_READ_DIR:
return "read_dir"
case LANDLOCK_ACCESS_FS_REMOVE_DIR:
return "remove_dir"
case LANDLOCK_ACCESS_FS_REMOVE_FILE:
return "remove_file"
case LANDLOCK_ACCESS_FS_MAKE_CHAR:
return "make_char"
case LANDLOCK_ACCESS_FS_MAKE_DIR:
return "make_dir"
case LANDLOCK_ACCESS_FS_MAKE_REG:
return "make_reg"
case LANDLOCK_ACCESS_FS_MAKE_SOCK:
return "make_sock"
case LANDLOCK_ACCESS_FS_MAKE_FIFO:
return "make_fifo"
case LANDLOCK_ACCESS_FS_MAKE_BLOCK:
return "make_block"
case LANDLOCK_ACCESS_FS_MAKE_SYM:
return "make_sym"
case LANDLOCK_ACCESS_FS_REFER:
return "fs_refer"
case LANDLOCK_ACCESS_FS_TRUNCATE:
return "fs_truncate"
case LANDLOCK_ACCESS_FS_IOCTL_DEV:
return "fs_ioctl_dev"
default:
var c []AccessFS
for i := AccessFS(1); i < _LANDLOCK_ACCESS_FS_DELIM; i <<= 1 {
if f&i != 0 {
c = append(c, i)
}
}
if len(c) == 0 {
return "NULL"
}
s := make([]string, len(c))
for i, v := range c {
s[i] = v.String()
}
return strings.Join(s, " ")
}
}
// AccessNet is bitmask of handled network actions.
type AccessNet uint64
const (
LANDLOCK_ACCESS_NET_BIND_TCP AccessNet = 1 << iota
LANDLOCK_ACCESS_NET_CONNECT_TCP
_LANDLOCK_ACCESS_NET_DELIM
)
// String returns a space-separated string of [AccessNet] flags.
func (f AccessNet) String() string {
switch f {
case LANDLOCK_ACCESS_NET_BIND_TCP:
return "bind_tcp"
case LANDLOCK_ACCESS_NET_CONNECT_TCP:
return "connect_tcp"
default:
var c []AccessNet
for i := AccessNet(1); i < _LANDLOCK_ACCESS_NET_DELIM; i <<= 1 {
if f&i != 0 {
c = append(c, i)
}
}
if len(c) == 0 {
return "NULL"
}
s := make([]string, len(c))
for i, v := range c {
s[i] = v.String()
}
return strings.Join(s, " ")
}
}
// Scope is bitmask of scopes restricting a Landlock domain from accessing outside resources.
type Scope uint64
const (
LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET Scope = 1 << iota
LANDLOCK_SCOPE_SIGNAL
_LANDLOCK_SCOPE_DELIM
)
// String returns a space-separated string of [Scope] flags.
func (f Scope) String() string {
switch f {
case LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET:
return "abstract_unix_socket"
case LANDLOCK_SCOPE_SIGNAL:
return "signal"
default:
var c []Scope
for i := Scope(1); i < _LANDLOCK_SCOPE_DELIM; i <<= 1 {
if f&i != 0 {
c = append(c, i)
}
}
if len(c) == 0 {
return "NULL"
}
s := make([]string, len(c))
for i, v := range c {
s[i] = v.String()
}
return strings.Join(s, " ")
}
}
// RulesetAttr is equivalent to struct landlock_ruleset_attr.
type RulesetAttr struct {
// Bitmask of handled filesystem actions.
HandledAccessFS AccessFS
// Bitmask of handled network actions.
HandledAccessNet AccessNet
// Bitmask of scopes restricting a Landlock domain from accessing outside
// resources (e.g. IPCs).
Scoped Scope
}
// String returns a user-facing description of [RulesetAttr].
func (rulesetAttr *RulesetAttr) String() string {
if rulesetAttr == nil {
return "NULL"
}
elems := make([]string, 0, 3)
if rulesetAttr.HandledAccessFS > 0 {
elems = append(elems, "fs: "+rulesetAttr.HandledAccessFS.String())
}
if rulesetAttr.HandledAccessNet > 0 {
elems = append(elems, "net: "+rulesetAttr.HandledAccessNet.String())
}
if rulesetAttr.Scoped > 0 {
elems = append(elems, "scoped: "+rulesetAttr.Scoped.String())
}
if len(elems) == 0 {
return "0"
}
return strings.Join(elems, ", ")
}
// Create loads the ruleset into the kernel.
func (rulesetAttr *RulesetAttr) Create(flags uintptr) (fd int, err error) {
var pointer, size uintptr
// NULL needed for abi version
if rulesetAttr != nil {
pointer = uintptr(unsafe.Pointer(rulesetAttr))
size = unsafe.Sizeof(*rulesetAttr)
}
rulesetFd, _, errno := syscall.Syscall(
ext.SYS_LANDLOCK_CREATE_RULESET,
pointer, size,
flags,
)
fd = int(rulesetFd)
err = errno
if fd < 0 {
return
}
if rulesetAttr != nil { // not a fd otherwise
syscall.CloseOnExec(fd)
}
return fd, nil
}
// GetABI returns the ABI version supported by the kernel.
func GetABI() (int, error) {
return (*RulesetAttr)(nil).Create(LANDLOCK_CREATE_RULESET_VERSION)
}
// RestrictSelf applies a loaded ruleset to the calling thread.
func RestrictSelf(rulesetFd int, flags uintptr) error {
r, _, errno := syscall.Syscall(
ext.SYS_LANDLOCK_RESTRICT_SELF,
uintptr(rulesetFd),
flags,
0,
)
if r != 0 {
return errno
}
return nil
}
|
