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os/vendor/github.com/vmware/vmw-guestinfo/message/message.go
Sven Dowideit be2c4044ce cloudinit tests pass :)
Signed-off-by: Sven Dowideit <SvenDowideit@home.org.au>
2017-02-28 13:58:34 +10:00

335 lines
8.7 KiB
Go

// Copyright 2016 VMware, Inc. All Rights Reserved.
//
// 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.
package message
import (
"bytes"
"encoding/binary"
"errors"
"unsafe"
"github.com/vmware/vmw-guestinfo/bdoor"
)
const (
messageTypeOpen = iota
messageTypeSendSize
messageTypeSendPayload
messageTypeReceiveSize
messageTypeReceivePayload
messageTypeReceiveStatus
messageTypeClose
messageStatusFail = uint16(0x0000)
messageStatusSuccess = uint16(0x0001)
messageStatusDoRecieve = uint16(0x0002)
messageStatusCheckPoint = uint16(0x0010)
messageStatusHighBW = uint16(0x0080)
)
var (
// ErrChannelOpen represents a failure to open a channel
ErrChannelOpen = errors.New("could not open channel")
// ErrChannelClose represents a failure to close a channel
ErrChannelClose = errors.New("could not close channel")
// ErrRpciSend represents a failure to send a message
ErrRpciSend = errors.New("unable to send RPCI command")
// ErrRpciReceive represents a failure to receive a message
ErrRpciReceive = errors.New("unable to receive RPCI command result")
)
type Channel struct {
id uint16
forceLowBW bool
buf []byte
cookie bdoor.UInt64
}
// NewChannel opens a new Channel
func NewChannel(proto uint32) (*Channel, error) {
flags := bdoor.CommandFlagCookie
retry:
bp := &bdoor.BackdoorProto{}
bp.BX.Low.SetWord(proto | flags)
bp.CX.Low.High = messageTypeOpen
bp.CX.Low.Low = bdoor.CommandMessage
out := bp.InOut()
if (out.CX.Low.High & messageStatusSuccess) == 0 {
if flags != 0 {
flags = 0
goto retry
}
Errorf("Message: Unable to open communication channel")
return nil, ErrChannelOpen
}
ch := &Channel{}
ch.id = out.DX.Low.High
ch.cookie.High.SetWord(out.SI.Low.Word())
ch.cookie.Low.SetWord(out.DI.Low.Word())
Debugf("Opened channel %d", ch.id)
return ch, nil
}
func (c *Channel) Close() error {
bp := &bdoor.BackdoorProto{}
bp.CX.Low.High = messageTypeClose
bp.CX.Low.Low = bdoor.CommandMessage
bp.DX.Low.High = c.id
bp.SI.Low.SetWord(c.cookie.High.Word())
bp.DI.Low.SetWord(c.cookie.Low.Word())
out := bp.InOut()
if (out.CX.Low.High & messageStatusSuccess) == 0 {
Errorf("Message: Unable to close communication channel %d", c.id)
return ErrChannelClose
}
Debugf("Closed channel %d", c.id)
return nil
}
func (c *Channel) Send(buf []byte) error {
retry:
bp := &bdoor.BackdoorProto{}
bp.CX.Low.High = messageTypeSendSize
bp.CX.Low.Low = bdoor.CommandMessage
bp.DX.Low.High = c.id
bp.SI.Low.SetWord(c.cookie.High.Word())
bp.DI.Low.SetWord(c.cookie.Low.Word())
bp.BX.Low.SetWord(uint32(len(buf)))
// send the size
out := bp.InOut()
if (out.CX.Low.High & messageStatusSuccess) == 0 {
Errorf("Message: Unable to send a message over the communication channel %d", c.id)
return ErrRpciSend
}
// size of buf 0 is fine, just return
if len(buf) == 0 {
return nil
}
if !c.forceLowBW && (out.CX.Low.High&messageStatusHighBW) == messageStatusHighBW {
hbbp := &bdoor.BackdoorProto{}
hbbp.BX.Low.Low = bdoor.CommandHighBWMessage
hbbp.BX.Low.High = messageStatusSuccess
hbbp.DX.Low.High = c.id
hbbp.BP.Low.SetWord(c.cookie.High.Word())
hbbp.DI.Low.SetWord(c.cookie.Low.Word())
hbbp.CX.Low.SetWord(uint32(len(buf)))
hbbp.SI.SetQuad(uint64(uintptr(unsafe.Pointer(&buf[0]))))
out := hbbp.HighBandwidthOut()
if (out.BX.Low.High & messageStatusSuccess) == 0 {
if (out.BX.Low.High & messageStatusCheckPoint) != 0 {
Debugf("A checkpoint occurred. Retrying the operation")
goto retry
}
Errorf("Message: Unable to send a message over the communication channel %d", c.id)
return ErrRpciSend
}
} else {
bp.CX.Low.High = messageTypeSendPayload
bbuf := bytes.NewBuffer(buf)
for {
// read 4 bytes at a time
words := bbuf.Next(4)
if len(words) == 0 {
break
}
Debugf("sending %q over %d", string(words), c.id)
switch len(words) {
case 3:
bp.BX.Low.SetWord(binary.LittleEndian.Uint32([]byte{0x0, words[2], words[1], words[0]}))
case 2:
bp.BX.Low.SetWord(uint32(binary.LittleEndian.Uint16(words)))
case 1:
bp.BX.Low.SetWord(uint32(words[0]))
default:
bp.BX.Low.SetWord(binary.LittleEndian.Uint32(words))
}
out = bp.InOut()
if (out.CX.Low.High & messageStatusSuccess) == 0 {
Errorf("Message: Unable to send a message over the communication channel %d", c.id)
return ErrRpciSend
}
}
}
return nil
}
func (c *Channel) Receive() ([]byte, error) {
retry:
var err error
bp := &bdoor.BackdoorProto{}
bp.CX.Low.High = messageTypeReceiveSize
bp.CX.Low.Low = bdoor.CommandMessage
bp.DX.Low.High = c.id
bp.SI.Low.SetWord(c.cookie.High.Word())
bp.DI.Low.SetWord(c.cookie.Low.Word())
out := bp.InOut()
if (out.CX.Low.High & messageStatusSuccess) == 0 {
Errorf("Message: Unable to poll for messages over the communication channel %d", c.id)
return nil, ErrRpciReceive
}
if (out.CX.Low.High & messageStatusDoRecieve) == 0 {
Debugf("No message to retrieve")
return nil, nil
}
// Receive the size.
if out.DX.Low.High != messageTypeSendSize {
Errorf("Message: Protocol error. Expected a MESSAGE_TYPE_SENDSIZE request from vmware")
return nil, ErrRpciReceive
}
size := out.BX.Quad()
var buf []byte
if size != 0 {
if !c.forceLowBW && (out.CX.Low.High&messageStatusHighBW == messageStatusHighBW) {
buf = make([]byte, size)
hbbp := &bdoor.BackdoorProto{}
hbbp.BX.Low.Low = bdoor.CommandHighBWMessage
hbbp.BX.Low.High = messageStatusSuccess
hbbp.DX.Low.High = c.id
hbbp.SI.Low.SetWord(c.cookie.High.Word())
hbbp.BP.Low.SetWord(c.cookie.Low.Word())
hbbp.CX.Low.SetWord(uint32(len(buf)))
hbbp.DI.SetQuad(uint64(uintptr(unsafe.Pointer(&buf[0]))))
out := hbbp.HighBandwidthIn()
if (out.BX.Low.High & messageStatusSuccess) == 0 {
Errorf("Message: Unable to send a message over the communication channel %d", c.id)
c.reply(messageTypeReceivePayload, messageStatusFail)
return nil, ErrRpciReceive
}
} else {
b := bytes.NewBuffer(make([]byte, 0, size))
for {
if size == 0 {
break
}
bp.CX.Low.High = messageTypeReceivePayload
bp.BX.Low.Low = messageStatusSuccess
out = bp.InOut()
if (out.CX.Low.High & messageStatusSuccess) == 0 {
if (out.CX.Low.High & messageStatusCheckPoint) != 0 {
Debugf("A checkpoint occurred. Retrying the operation")
goto retry
}
Errorf("Message: Unable to receive a message over the communication channel %d", c.id)
c.reply(messageTypeReceivePayload, messageStatusFail)
return nil, ErrRpciReceive
}
if out.DX.Low.High != messageTypeSendPayload {
Errorf("Message: Protocol error. Expected a MESSAGE_TYPE_SENDPAYLOAD from vmware")
c.reply(messageTypeReceivePayload, messageStatusFail)
return nil, ErrRpciReceive
}
Debugf("Received %#v", out.BX.Low.Word())
switch size {
case 1:
err = binary.Write(b, binary.LittleEndian, uint8(out.BX.Low.Low))
size = size - 1
case 2:
err = binary.Write(b, binary.LittleEndian, uint16(out.BX.Low.Low))
size = size - 2
case 3:
err = binary.Write(b, binary.LittleEndian, uint16(out.BX.Low.Low))
if err != nil {
c.reply(messageTypeReceivePayload, messageStatusFail)
return nil, ErrRpciReceive
}
err = binary.Write(b, binary.LittleEndian, uint8(out.BX.Low.High))
size = size - 3
default:
err = binary.Write(b, binary.LittleEndian, out.BX.Low.Word())
size = size - 4
}
if err != nil {
Errorf(err.Error())
c.reply(messageTypeReceivePayload, messageStatusFail)
return nil, ErrRpciReceive
}
}
buf = b.Bytes()
}
}
c.reply(messageTypeReceiveStatus, messageStatusSuccess)
return buf, nil
}
func (c *Channel) reply(messageType, messageStatus uint16) {
bp := &bdoor.BackdoorProto{}
bp.BX.Low.Low = messageStatus
bp.CX.Low.High = messageType
bp.CX.Low.Low = bdoor.CommandMessage
bp.DX.Low.High = c.id
bp.SI.Low.SetWord(c.cookie.High.Word())
bp.DI.Low.SetWord(c.cookie.Low.Word())
out := bp.InOut()
/* OUT: Status */
if (out.CX.Low.High & messageStatusSuccess) == 0 {
if messageStatus == messageStatusSuccess {
Errorf("reply Message: Unable to send a message over the communication channel %d", c.id)
} else {
Errorf("reply Message: Unable to signal an error of reception over the communication channel %d", c.id)
}
}
}