Initial

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

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

@@ -0,0 +1,154 @@
+// 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     int32
+}
+
+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
+}
+
+// not yet in syscall
+const (
+	pr_CAP_AMBIENT           = 47
+	pr_CAP_AMBIENT_IS_SET    = uintptr(1)
+	pr_CAP_AMBIENT_RAISE     = uintptr(2)
+	pr_CAP_AMBIENT_LOWER     = uintptr(3)
+	pr_CAP_AMBIENT_CLEAR_ALL = uintptr(4)
+)
+
+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
+}