cloudinit/vendor/github.com/sigma/vmw-guestinfo/rpcout/rpcout.go
Vasiliy Tolstov 414957d985 fix build
Signed-off-by: Vasiliy Tolstov <v.tolstov@selfip.ru>
2015-11-09 09:08:44 +00:00

80 lines
1.6 KiB
Go

package rpcout
import (
"errors"
"fmt"
"github.com/sigma/vmw-guestinfo/message"
)
// ErrRpciFormat represents an invalid result format
var ErrRpciFormat = errors.New("invalid format for RPCI command result")
const rpciProtocolNum uint32 = 0x49435052
// SendOne is a command-oriented wrapper for SendOneRaw
func SendOne(format string, a ...interface{}) (reply []byte, ok bool, err error) {
request := fmt.Sprintf(format, a...)
return SendOneRaw([]byte(request))
}
// SendOneRaw uses a throw-away RPCOut to send a request
func SendOneRaw(request []byte) (reply []byte, ok bool, err error) {
out := &RPCOut{}
if err = out.Start(); err != nil {
return
}
if reply, ok, err = out.Send(request); err != nil {
return
}
if err = out.Stop(); err != nil {
return
}
return
}
// RPCOut is an ougoing connection from the VM to the hypervisor
type RPCOut struct {
channel *message.Channel
}
// Start opens the connection
func (out *RPCOut) Start() error {
channel, err := message.NewChannel(rpciProtocolNum)
if err != nil {
return err
}
out.channel = channel
return nil
}
// Stop closes the connection
func (out *RPCOut) Stop() error {
err := out.channel.Close()
out.channel = nil
return err
}
// Send emits a request and receives a response
func (out *RPCOut) Send(request []byte) (reply []byte, ok bool, err error) {
if err = out.channel.Send(request); err != nil {
return
}
var resp []byte
if resp, err = out.channel.Receive(); err != nil {
return
}
switch string(resp[:2]) {
case "0 ":
reply = resp[2:]
case "1 ":
reply = resp[2:]
ok = true
default:
err = ErrRpciFormat
}
return
}