kops/vendor/github.com/google/go-tdx-guest/client/client_linux.go

132 lines
3.7 KiB
Go

// Copyright 2023 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//go:build linux
// Package client provides an interface to the Intel TDX guest device commands.
package client
import (
"fmt"
"unsafe"
"github.com/google/go-configfs-tsm/configfs/linuxtsm"
"github.com/google/go-configfs-tsm/report"
labi "github.com/google/go-tdx-guest/client/linuxabi"
"golang.org/x/sys/unix"
)
// defaultTdxGuestDevicePath is the platform's usual device path to the TDX guest.
const defaultTdxGuestDevicePath = "/dev/tdx_guest"
// LinuxDevice implements the Device interface with Linux ioctls.
type LinuxDevice struct {
fd int
}
// Open opens the TDX guest device from a given path
func (d *LinuxDevice) Open(path string) error {
fd, err := unix.Open(path, unix.O_RDWR|unix.O_SYNC, 0)
if err != nil {
d.fd = -1
return fmt.Errorf("could not open Intel TDX guest device at %q: %v", path, err)
}
d.fd = fd
return nil
}
// OpenDevice opens the TDX guest device.
func OpenDevice() (*LinuxDevice, error) {
result := &LinuxDevice{}
path := *tdxGuestPath
if UseDefaultTdxGuestDevice() {
path = defaultTdxGuestDevicePath
}
if err := result.Open(path); err != nil {
return nil, err
}
return result, nil
}
// Close closes the TDX guest device.
func (d *LinuxDevice) Close() error {
if d.fd == -1 { // Not open
return nil
}
if err := unix.Close(d.fd); err != nil {
return err
}
// Prevent double-close.
d.fd = -1
return nil
}
// Ioctl sends a command with its wrapped request and response values to the Linux device.
func (d *LinuxDevice) Ioctl(command uintptr, req any) (uintptr, error) {
if d.fd == -1 {
return 0, fmt.Errorf("intel TDX Guest Device is not open")
}
switch sreq := req.(type) {
case *labi.TdxQuoteReq:
abi := sreq.ABI()
result, _, errno := unix.Syscall(unix.SYS_IOCTL, uintptr(d.fd), command, uintptr(abi.Pointer()))
abi.Finish(sreq)
if errno == unix.EBUSY {
return 0, errno
} else if errno == unix.ENOTTY {
return 0, fmt.Errorf("invalid ioctl! use QuoteProvider to fetch attestation quote")
} else if errno != 0 {
return 0, errno
}
return result, nil
case *labi.TdxReportReq:
result, _, errno := unix.Syscall(unix.SYS_IOCTL, uintptr(d.fd), command, uintptr(unsafe.Pointer(req.(*labi.TdxReportReq))))
if errno != 0 {
return 0, errno
}
return result, nil
}
return 0, fmt.Errorf("unexpected request value: %v", req)
}
// LinuxConfigFsQuoteProvider implements the QuoteProvider interface to fetch
// attestation quote via ConfigFS.
type LinuxConfigFsQuoteProvider struct{}
// IsSupported checks if TSM client can be created to use ConfigFS system.
func (p *LinuxConfigFsQuoteProvider) IsSupported() error {
_, err := linuxtsm.MakeClient()
return err
}
// GetRawQuote returns byte format attestation quote via ConfigFS.
func (p *LinuxConfigFsQuoteProvider) GetRawQuote(reportData [64]byte) ([]uint8, error) {
req := &report.Request{
InBlob: reportData[:],
GetAuxBlob: false,
}
resp, err := linuxtsm.GetReport(req)
if err != nil {
return nil, err
}
tdReport := resp.OutBlob
return tdReport, nil
}
// GetQuoteProvider returns an instance of LinuxConfigFsQuoteProvider.
func GetQuoteProvider() (*LinuxConfigFsQuoteProvider, error) {
return &LinuxConfigFsQuoteProvider{}, nil
}