139 lines
2.7 KiB
Go
139 lines
2.7 KiB
Go
package comms
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import (
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"encoding/gob"
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"fmt"
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"github.com/hashicorp/yamux"
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"io"
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"log"
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"net"
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"os"
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"os/user"
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"time"
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)
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type CommChannel struct {
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Peer net.Conn
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Encoder *gob.Encoder
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Decoder *gob.Decoder
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Session *yamux.Session
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}
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type Role int
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const (
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Agent Role = iota
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ConvergeServer
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)
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func NewCommChannel(role Role, wsConn io.ReadWriteCloser) (CommChannel, error) {
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var commChannel CommChannel
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switch role {
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case Agent:
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listener, err := yamux.Server(wsConn, nil)
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if err != nil {
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return CommChannel{}, err
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}
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commChannel = CommChannel{
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Peer: nil,
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Session: listener,
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}
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case ConvergeServer:
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clientSession, err := yamux.Client(wsConn, nil)
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if err != nil {
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return CommChannel{}, err
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}
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commChannel = CommChannel{
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Peer: nil,
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Session: clientSession,
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}
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default:
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panic(fmt.Errorf("Undefined role %d", role))
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}
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// communication between Agent and ConvergeServer
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// Currently used only fof communication from Agent to ConvergeServer
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switch role {
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case Agent:
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conn, err := commChannel.Session.OpenStream()
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commChannel.Peer = conn
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if err != nil {
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return CommChannel{}, err
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}
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case ConvergeServer:
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conn, err := commChannel.Session.Accept()
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commChannel.Peer = conn
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if err != nil {
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return CommChannel{}, err
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}
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default:
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panic(fmt.Errorf("Undefined role %d", role))
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}
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log.Println("Communication channel between agent and converge server established")
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gob.Register(SessionInfo{})
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gob.Register(ExpiryTimeUpdate{})
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gob.Register(ConvergeMessage{})
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commChannel.Encoder = gob.NewEncoder(commChannel.Peer)
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commChannel.Decoder = gob.NewDecoder(commChannel.Peer)
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switch role {
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case ConvergeServer:
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go serverReader(commChannel)
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}
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return commChannel, nil
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}
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func serverReader(channel CommChannel) {
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for {
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var result ConvergeMessage
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err := channel.Decoder.Decode(&result)
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if err != nil {
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// TODO more clean solution, need to explicitly close when agent exits.
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log.Printf("Exiting serverReader %v", err)
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return
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}
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switch v := result.Value.(type) {
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case SessionInfo:
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log.Println("RECEIVED: session info ", v)
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case ExpiryTimeUpdate:
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log.Println("RECEIVED: expirytime update ", v)
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default:
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fmt.Printf(" Unknown type: %T\n", v)
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}
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}
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}
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type SessionInfo struct {
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Username string
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Hostname string
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Pwd string
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}
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func NewSessionInfo() SessionInfo {
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username, _ := user.Current()
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host, _ := os.Hostname()
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pwd, _ := os.Getwd()
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return SessionInfo{
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Username: username.Username,
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Hostname: host,
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Pwd: pwd,
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}
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}
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type ExpiryTimeUpdate struct {
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ExpiryTime time.Time
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}
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type ConvergeMessage struct {
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Value interface{}
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}
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func NewExpiryTimeUpdate(expiryTime time.Time) ExpiryTimeUpdate {
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return ExpiryTimeUpdate{ExpiryTime: expiryTime}
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}
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