DockerCLI/vendor/github.com/syndtr/gocapability/capability/syscall_linux.go

146 lines
3.1 KiB
Go

// Copyright (c) 2013, Suryandaru Triandana <syndtr@gmail.com>
// All rights reserved.
//
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
package capability
import (
"syscall"
"unsafe"
)
type capHeader struct {
version uint32
pid int
}
type capData struct {
effective uint32
permitted uint32
inheritable uint32
}
func capget(hdr *capHeader, data *capData) (err error) {
_, _, e1 := syscall.Syscall(syscall.SYS_CAPGET, uintptr(unsafe.Pointer(hdr)), uintptr(unsafe.Pointer(data)), 0)
if e1 != 0 {
err = e1
}
return
}
func capset(hdr *capHeader, data *capData) (err error) {
_, _, e1 := syscall.Syscall(syscall.SYS_CAPSET, uintptr(unsafe.Pointer(hdr)), uintptr(unsafe.Pointer(data)), 0)
if e1 != 0 {
err = e1
}
return
}
func prctl(option int, arg2, arg3, arg4, arg5 uintptr) (err error) {
_, _, e1 := syscall.Syscall6(syscall.SYS_PRCTL, uintptr(option), arg2, arg3, arg4, arg5, 0)
if e1 != 0 {
err = e1
}
return
}
const (
vfsXattrName = "security.capability"
vfsCapVerMask = 0xff000000
vfsCapVer1 = 0x01000000
vfsCapVer2 = 0x02000000
vfsCapFlagMask = ^vfsCapVerMask
vfsCapFlageffective = 0x000001
vfscapDataSizeV1 = 4 * (1 + 2*1)
vfscapDataSizeV2 = 4 * (1 + 2*2)
)
type vfscapData struct {
magic uint32
data [2]struct {
permitted uint32
inheritable uint32
}
effective [2]uint32
version int8
}
var (
_vfsXattrName *byte
)
func init() {
_vfsXattrName, _ = syscall.BytePtrFromString(vfsXattrName)
}
func getVfsCap(path string, dest *vfscapData) (err error) {
var _p0 *byte
_p0, err = syscall.BytePtrFromString(path)
if err != nil {
return
}
r0, _, e1 := syscall.Syscall6(syscall.SYS_GETXATTR, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_vfsXattrName)), uintptr(unsafe.Pointer(dest)), vfscapDataSizeV2, 0, 0)
if e1 != 0 {
if e1 == syscall.ENODATA {
dest.version = 2
return
}
err = e1
}
switch dest.magic & vfsCapVerMask {
case vfsCapVer1:
dest.version = 1
if r0 != vfscapDataSizeV1 {
return syscall.EINVAL
}
dest.data[1].permitted = 0
dest.data[1].inheritable = 0
case vfsCapVer2:
dest.version = 2
if r0 != vfscapDataSizeV2 {
return syscall.EINVAL
}
default:
return syscall.EINVAL
}
if dest.magic&vfsCapFlageffective != 0 {
dest.effective[0] = dest.data[0].permitted | dest.data[0].inheritable
dest.effective[1] = dest.data[1].permitted | dest.data[1].inheritable
} else {
dest.effective[0] = 0
dest.effective[1] = 0
}
return
}
func setVfsCap(path string, data *vfscapData) (err error) {
var _p0 *byte
_p0, err = syscall.BytePtrFromString(path)
if err != nil {
return
}
var size uintptr
if data.version == 1 {
data.magic = vfsCapVer1
size = vfscapDataSizeV1
} else if data.version == 2 {
data.magic = vfsCapVer2
if data.effective[0] != 0 || data.effective[1] != 0 {
data.magic |= vfsCapFlageffective
}
size = vfscapDataSizeV2
} else {
return syscall.EINVAL
}
_, _, e1 := syscall.Syscall6(syscall.SYS_SETXATTR, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_vfsXattrName)), uintptr(unsafe.Pointer(data)), size, 0, 0)
if e1 != 0 {
err = e1
}
return
}