Beispiel #1
0
func (mon *SlaveMonitor) slaveDidBeginRegistration(fd int) {
	// Having just started the process, we expect an IO, which we convert to a UNIX domain socket
	fileName := strconv.Itoa(rand.Int())
	slaveFile := unixsocket.FdToFile(fd, fileName)
	slaveUsock, err := unixsocket.NewUsockFromFile(slaveFile)
	if err != nil {
		fmt.Println(err)
	}
	if err = slaveUsock.Conn.SetReadBuffer(1024); err != nil {
		fmt.Println(err)
	}
	if err = slaveUsock.Conn.SetWriteBuffer(1024); err != nil {
		fmt.Println(err)
	}

	// We now expect the slave to use this fd they send us to send a Pid&Identifier Message
	msg, err := slaveUsock.ReadMessage()
	if err != nil {
		fmt.Println(err)
	}
	pid, identifier, err := ParsePidMessage(msg)

	slaveNode := mon.tree.FindSlaveByName(identifier)
	if slaveNode == nil {
		panic("slavemonitor.go:slaveDidBeginRegistration:Unknown identifier:" + identifier)
	}

	go slaveNode.Run(identifier, pid, slaveUsock)
}
Beispiel #2
0
func bootNewCommand(slaveNode *processtree.SlaveNode, command string, err error) (*unixsocket.Usock, error) {
	if err != nil {
		return nil, err
	}

	request := &processtree.CommandRequest{command, make(chan *os.File)}
	slaveNode.RequestCommandBoot(request)
	commandFile := <-request.Retchan // TODO: don't really want to wait indefinitely.
	// defer commandFile.Close() // TODO: can't do this here anymore.

	return unixsocket.NewUsockFromFile(commandFile)
}
Beispiel #3
0
func Run(color bool) {
	if !color {
		slog.DisableColor()
		DisableErrorColor()
	}
	slog.StartingZeus()

	var tree *ProcessTree = BuildProcessTree()

	exitNow = make(chan int)

	localMasterFile, remoteMasterFile, err := unixsocket.Socketpair(syscall.SOCK_DGRAM)
	if err != nil {
		panic(err)
	}

	localMasterSocket, err := unixsocket.NewUsockFromFile(localMasterFile)
	if err != nil {
		panic(err)
	}

	quit1 := make(chan bool)
	quit2 := make(chan bool)
	quit3 := make(chan bool)

	go StartSlaveMonitor(tree, localMasterSocket, remoteMasterFile, quit1)
	go StartClientHandler(tree, quit2)
	go StartFileMonitor(tree, quit3)

	quit := make(chan bool, 1)

	c := make(chan os.Signal, 1)
	signal.Notify(c, os.Interrupt)
	go func() {
		<-c
		// FIXME: Unprecedented levels of jank, right here.
		terminateComponents(quit1, quit2, quit3, quit)
	}()

	go func() {
		exitStatus = <-exitNow
		terminateComponents(quit1, quit2, quit3, quit)
	}()

	<-quit
	<-quit
	<-quit

	os.Exit(exitStatus)
}
Beispiel #4
0
func bootNewCommand(slaveNode *processtree.SlaveNode, command string, err error) (*unixsocket.Usock, error) {
	if err != nil {
		return nil, err
	}

	request := &processtree.CommandRequest{command, make(chan *processtree.CommandReply)}
	slaveNode.RequestCommandBoot(request)
	reply := <-request.Retchan // TODO: don't really want to wait indefinitely.
	// defer commandFile.Close() // TODO: can't do this here anymore.

	if reply.State == processtree.SCrashed {
		return nil, errors.New("Process has crashed")
	}

	return unixsocket.NewUsockFromFile(reply.File)
}
Beispiel #5
0
func StartSlaveMonitor(tree *ProcessTree, quit chan bool) {
	monitor := &SlaveMonitor{tree}

	localMasterFile, remoteMasterFile, err := unixsocket.Socketpair(syscall.SOCK_DGRAM)
	if err != nil {
		panic(err)
	}

	localMasterSocket, err := unixsocket.NewUsockFromFile(localMasterFile)
	if err != nil {
		panic(err)
	}

	// We just want this unix socket to be a channel so we can select on it...
	registeringFds := make(chan int, 3)
	go func() {
		for {
			fd, err := localMasterSocket.ReadFD()
			if err != nil {
				fmt.Println(err)
			}
			registeringFds <- fd
		}
	}()

	for _, slave := range monitor.tree.SlavesByName {
		if slave.Parent == nil {
			go monitor.startInitialProcess(remoteMasterFile)
		} else {
			go monitor.bootSlave(slave)
		}
	}

	for {
		select {
		case <-quit:
			quit <- true
			monitor.cleanupChildren()
			return
		case fd := <-registeringFds:
			monitor.slaveDidBeginRegistration(fd)
		}
	}
}
Beispiel #6
0
func StartSlaveMonitor(tree *ProcessTree, done chan bool) chan bool {
	quit := make(chan bool)
	go func() {
		localMasterFile, remoteMasterFile, err := unixsocket.Socketpair(syscall.SOCK_DGRAM)
		if err != nil {
			Error("Couldn't create socketpair")
		}

		monitor := &SlaveMonitor{tree, remoteMasterFile}

		localMasterSocket, err := unixsocket.NewUsockFromFile(localMasterFile)
		if err != nil {
			Error("Couldn't Open UNIXSocket")
		}

		// We just want this unix socket to be a channel so we can select on it...
		registeringFds := make(chan int, 3)
		go func() {
			for {
				fd, err := localMasterSocket.ReadFD()
				if err != nil {
					slog.Error(err)
				}
				registeringFds <- fd
			}
		}()

		for _, slave := range monitor.tree.SlavesByName {
			go slave.Run(monitor)
		}

		for {
			select {
			case <-quit:
				monitor.cleanupChildren()
				done <- true
				return
			case fd := <-registeringFds:
				go monitor.slaveDidBeginRegistration(fd)
			}
		}
	}()
	return quit
}
Beispiel #7
0
func (mon *SlaveMonitor) slaveDidBeginRegistration(fd int) {
	// Having just started the process, we expect an IO, which we convert to a UNIX domain socket
	fileName := strconv.Itoa(rand.Int())
	slaveFile := unixsocket.FdToFile(fd, fileName)
	slaveUsock, err := unixsocket.NewUsockFromFile(slaveFile)
	if err != nil {
		slog.Error(err)
	}
	if err = slaveUsock.Conn.SetReadBuffer(1024); err != nil {
		slog.Error(err)
	}
	if err = slaveUsock.Conn.SetWriteBuffer(1024); err != nil {
		slog.Error(err)
	}

	// We now expect the slave to use this fd they send us to send a Pid&Identifier Message
	msg, err := slaveUsock.ReadMessage()
	if err != nil {
		slog.Error(err)
	}
	pid, identifier, err := messages.ParsePidMessage(msg)

	// And the last step before executing its action, the slave sends us a pipe it will later use to
	// send us all the features it's loaded.
	featurePipeFd, err := slaveUsock.ReadFD()
	if err != nil {
		slog.Error(err)
	}

	slaveNode := mon.tree.FindSlaveByName(identifier)
	if slaveNode == nil {
		Error("slavemonitor.go:slaveDidBeginRegistration:Unknown identifier:" + identifier)
	}

	slaveNode.SlaveWasInitialized(pid, slaveUsock, featurePipeFd)
}
Beispiel #8
0
// see docs/client_master_handshake.md
func handleClientConnection(tree *ProcessTree, usock *unixsocket.Usock) {
	defer usock.Close()

	// we have established first contact to the client.

	// we first read the command and arguments specified from the connection. (step 1)
	msg, err := usock.ReadMessage()
	if err != nil {
		fmt.Println("clienthandler.go:handleClientConnection:read command and arguments:", err)
		return
	}
	command, arguments, err := ParseClientCommandRequestMessage(msg)
	if err != nil {
		fmt.Println("clienthandler.go:handleClientConnection:parse command and arguments:", err)
		return
	}

	commandNode := tree.FindCommand(command)
	if commandNode == nil {
		fmt.Println("ERROR: Node not found!: ", command)
		return
	}
	command = commandNode.Name // resolve aliases
	slaveNode := commandNode.Parent

	// Now we read the terminal IO socket to use for raw IO (step 2)
	clientFd, err := usock.ReadFD()
	if err != nil {
		fmt.Println("Expected FD, none received!")
		return
	}
	fileName := strconv.Itoa(rand.Int())
	clientFile := unixsocket.FdToFile(clientFd, fileName)
	defer clientFile.Close()

	// We now need to fork a new command process.
	// For now, we naively assume it's running...

	if slaveNode.Error != "" {
		// we can skip steps 3-5 as they deal with the command process we're not spawning.
		// Write a fake pid (step 6)
		usock.WriteMessage("0")
		// Write the error message to the terminal
		clientFile.Write([]byte(slaveNode.Error))
		// Skip step 7, and write an exit code to the client (step 8)
		usock.WriteMessage("1")
		return
	}

	// boot a command process and establish a socket connection to it.
	slaveNode.WaitUntilBooted()

	msg = CreateSpawnCommandMessage(command)
	slaveNode.mu.Lock()
	unixsocket.NewUsock(slaveNode.Socket).WriteMessage(msg)
	slaveNode.mu.Unlock()

	// TODO: deadline? how to respond if this is never sent?
	commandFd := <-slaveNode.ClientCommandPTYFileDescriptor
	if err != nil {
		fmt.Println("Couldn't start command process!", err)
	}
	fileName = strconv.Itoa(rand.Int())
	commandFile := unixsocket.FdToFile(commandFd, fileName)
	defer commandFile.Close()

	commandUsock, err := unixsocket.NewUsockFromFile(commandFile)
	if err != nil {
		fmt.Println("MakeUnixSocket", err)
	}
	defer commandUsock.Close()

	// Send the arguments to the command process (step 3)
	commandUsock.WriteMessage(arguments)

	// Send the client terminal connection to the command process (step 4)
	commandUsock.WriteFD(clientFd)

	// Receive the pid from the command process (step 5)
	msg, err = commandUsock.ReadMessage()
	if err != nil {
		fmt.Println(err)
	}
	intPid, _, _ := ParsePidMessage(msg)

	// Send the pid to the client process (step 6)
	strPid := strconv.Itoa(intPid)
	usock.WriteMessage(strPid)

	// Receive the exit status from the command (step 7)
	msg, err = commandUsock.ReadMessage()
	if err != nil {
		fmt.Println("clienthandler.go:handleClientConnection:receive exit status:", err)
		return
	}

	// Forward the exit status to the Client (step 8)
	usock.WriteMessage(msg)

	// Done! Hooray!

}