Misc mutex locking things to avoid data races

router/tokens/websocket.go

@@ -4,10 +4,13 @@ import (
 	"encoding/json"
 	"github.com/gbrlsnchs/jwt/v3"
 	"strings"
+	"sync"
 )
 
 type WebsocketPayload struct {
 	jwt.Payload
+	sync.RWMutex
+
 	UserID      json.Number `json:"user_id"`
 	ServerUUID  string      `json:"server_uuid"`
 	Permissions []string    `json:"permissions"`
@@ -15,11 +18,24 @@ type WebsocketPayload struct {
 
 // Returns the JWT payload.
 func (p *WebsocketPayload) GetPayload() *jwt.Payload {
+	p.RLock()
+	defer p.RUnlock()
+
 	return &p.Payload
 }
 
+func (p *WebsocketPayload) GetServerUuid() string {
+	p.RLock()
+	defer p.RUnlock()
+
+	return p.ServerUUID
+}
+
 // Checks if the given token payload has a permission string.
 func (p *WebsocketPayload) HasPermission(permission string) bool {
+	p.RLock()
+	defer p.RUnlock()
+
 	for _, k := range p.Permissions {
 		if k == permission || (!strings.HasPrefix(permission, "admin") && k == "*") {
 			return true

router/websocket/websocket.go

@@ -127,10 +127,7 @@ func (h *Handler) TokenValid() error {
 		return errors.New("jwt does not have connect permission")
 	}
 
-	h.server.RLock()
-	defer h.server.RUnlock()
-
-	if h.server.Uuid != j.ServerUUID {
+	if h.server.Id() != j.GetServerUuid() {
 		return errors.New("jwt server uuid mismatch")
 	}
 

server/config_parser.go

@@ -10,7 +10,8 @@ import (
 func (s *Server) UpdateConfigurationFiles() {
 	wg := new(sync.WaitGroup)
 
-	for _, v := range s.processConfiguration.ConfigurationFiles {
+	files := s.ProcessConfiguration().ConfigurationFiles
+	for _, v := range files {
 		wg.Add(1)
 
 		go func(f parser.ConfigurationFile, server *Server) {

server/environment_docker.go

@@ -21,6 +21,7 @@ import (
 	"path/filepath"
 	"strconv"
 	"strings"
+	"sync"
 	"sync/atomic"
 	"time"
 )
@@ -44,6 +45,23 @@ type DockerEnvironment struct {
 	// Holds the stats stream used by the polling commands so that we can easily close
 	// it out.
 	stats io.ReadCloser
+
+	sync.RWMutex
+}
+
+// Set if this process is currently attached to the process.
+func (d *DockerEnvironment) SetAttached(a bool) {
+	d.Lock()
+	d.attached = a
+	d.Unlock()
+}
+
+// Determine if the this process is currently attached to the container.
+func (d *DockerEnvironment) IsAttached() bool {
+	d.RLock()
+	defer d.RUnlock()
+
+	return d.attached
 }
 
 // Creates a new base Docker environment. A server must still be attached to it.
@@ -72,7 +90,7 @@ func (d *DockerEnvironment) Type() string {
 
 // Determines if the container exists in this environment.
 func (d *DockerEnvironment) Exists() (bool, error) {
-	_, err := d.Client.ContainerInspect(context.Background(), d.Server.Uuid)
+	_, err := d.Client.ContainerInspect(context.Background(), d.Server.Id())
 
 	if err != nil {
 		// If this error is because the container instance wasn't found via Docker we
@@ -96,7 +114,7 @@ func (d *DockerEnvironment) Exists() (bool, error) {
 //
 // @see docker/client/errors.go
 func (d *DockerEnvironment) IsRunning() (bool, error) {
-	c, err := d.Client.ContainerInspect(context.Background(), d.Server.Uuid)
+	c, err := d.Client.ContainerInspect(context.Background(), d.Server.Id())
 	if err != nil {
 		return false, err
 	}
@@ -108,7 +126,7 @@ func (d *DockerEnvironment) IsRunning() (bool, error) {
 // making any changes to the operational state of the container. This allows memory, cpu,
 // and IO limitations to be adjusted on the fly for individual instances.
 func (d *DockerEnvironment) InSituUpdate() error {
-	if _, err := d.Client.ContainerInspect(context.Background(), d.Server.Uuid); err != nil {
+	if _, err := d.Client.ContainerInspect(context.Background(), d.Server.Id()); err != nil {
 		// If the container doesn't exist for some reason there really isn't anything
 		// we can do to fix that in this process (it doesn't make sense at least). In those
 		// cases just return without doing anything since we still want to save the configuration
@@ -130,7 +148,7 @@ func (d *DockerEnvironment) InSituUpdate() error {
 
 	ctx, cancel := context.WithTimeout(context.Background(), time.Second*10)
 	defer cancel()
-	if _, err := d.Client.ContainerUpdate(ctx, d.Server.Uuid, u); err != nil {
+	if _, err := d.Client.ContainerUpdate(ctx, d.Server.Id(), u); err != nil {
 		return errors.WithStack(err)
 	}
 
@@ -156,7 +174,7 @@ func (d *DockerEnvironment) OnBeforeStart() error {
 
 	// Always destroy and re-create the server container to ensure that synced data from
 	// the Panel is used.
-	if err := d.Client.ContainerRemove(context.Background(), d.Server.Uuid, types.ContainerRemoveOptions{RemoveVolumes: true}); err != nil {
+	if err := d.Client.ContainerRemove(context.Background(), d.Server.Id(), types.ContainerRemoveOptions{RemoveVolumes: true}); err != nil {
 		if !client.IsErrNotFound(err) {
 			return err
 		}
@@ -204,7 +222,7 @@ func (d *DockerEnvironment) Start() error {
 		return &suspendedError{}
 	}
 
-	if c, err := d.Client.ContainerInspect(context.Background(), d.Server.Uuid); err != nil {
+	if c, err := d.Client.ContainerInspect(context.Background(), d.Server.Id()); err != nil {
 		// Do nothing if the container is not found, we just don't want to continue
 		// to the next block of code here. This check was inlined here to guard againt
 		// a nil-pointer when checking c.State below.
@@ -259,7 +277,7 @@ func (d *DockerEnvironment) Start() error {
 	ctx, cancel := context.WithTimeout(context.Background(), time.Second*10)
 	defer cancel()
 
-	if err := d.Client.ContainerStart(ctx, d.Server.Uuid, types.ContainerStartOptions{}); err != nil {
+	if err := d.Client.ContainerStart(ctx, d.Server.Id(), types.ContainerStartOptions{}); err != nil {
 		return errors.WithStack(err)
 	}
 
@@ -272,7 +290,7 @@ func (d *DockerEnvironment) Start() error {
 // Stops the container that the server is running in. This will allow up to 10
 // seconds to pass before a failure occurs.
 func (d *DockerEnvironment) Stop() error {
-	stop := d.Server.processConfiguration.Stop
+	stop := d.Server.ProcessConfiguration().Stop
 	if stop.Type == api.ProcessStopSignal {
 		return d.Terminate(os.Kill)
 	}
@@ -284,7 +302,7 @@ func (d *DockerEnvironment) Stop() error {
 
 	t := time.Second * 10
 
-	return d.Client.ContainerStop(context.Background(), d.Server.Uuid, &t)
+	return d.Client.ContainerStop(context.Background(), d.Server.Id(), &t)
 }
 
 // Attempts to gracefully stop a server using the defined stop command. If the server
@@ -305,7 +323,7 @@ func (d *DockerEnvironment) WaitForStop(seconds int, terminate bool) error {
 	// Block the return of this function until the container as been marked as no
 	// longer running. If this wait does not end by the time seconds have passed,
 	// attempt to terminate the container, or return an error.
-	ok, errChan := d.Client.ContainerWait(ctx, d.Server.Uuid, container.WaitConditionNotRunning)
+	ok, errChan := d.Client.ContainerWait(ctx, d.Server.Id(), container.WaitConditionNotRunning)
 	select {
 	case <-ctx.Done():
 		if ctxErr := ctx.Err(); ctxErr != nil {
@@ -327,7 +345,7 @@ func (d *DockerEnvironment) WaitForStop(seconds int, terminate bool) error {
 
 // Forcefully terminates the container using the signal passed through.
 func (d *DockerEnvironment) Terminate(signal os.Signal) error {
-	c, err := d.Client.ContainerInspect(context.Background(), d.Server.Uuid)
+	c, err := d.Client.ContainerInspect(context.Background(), d.Server.Id())
 	if err != nil {
 		return errors.WithStack(err)
 	}
@@ -339,7 +357,7 @@ func (d *DockerEnvironment) Terminate(signal os.Signal) error {
 	d.Server.SetState(ProcessStoppingState)
 
 	return d.Client.ContainerKill(
-		context.Background(), d.Server.Uuid, strings.TrimSuffix(strings.TrimPrefix(signal.String(), "signal "), "ed"),
+		context.Background(), d.Server.Id(), strings.TrimSuffix(strings.TrimPrefix(signal.String(), "signal "), "ed"),
 	)
 }
 
@@ -349,7 +367,7 @@ func (d *DockerEnvironment) Destroy() error {
 	// Avoid crash detection firing off.
 	d.Server.SetState(ProcessStoppingState)
 
-	err := d.Client.ContainerRemove(context.Background(), d.Server.Uuid, types.ContainerRemoveOptions{
+	err := d.Client.ContainerRemove(context.Background(), d.Server.Id(), types.ContainerRemoveOptions{
 		RemoveVolumes: true,
 		RemoveLinks:   false,
 		Force:         true,
@@ -369,7 +387,7 @@ func (d *DockerEnvironment) Destroy() error {
 // Determine the container exit state and return the exit code and wether or not
 // the container was killed by the OOM killer.
 func (d *DockerEnvironment) ExitState() (uint32, bool, error) {
-	c, err := d.Client.ContainerInspect(context.Background(), d.Server.Uuid)
+	c, err := d.Client.ContainerInspect(context.Background(), d.Server.Id())
 	if err != nil {
 		// I'm not entirely sure how this can happen to be honest. I tried deleting a
 		// container _while_ a server was running and wings gracefully saw the crash and
@@ -395,7 +413,7 @@ func (d *DockerEnvironment) ExitState() (uint32, bool, error) {
 // miss important output at the beginning because of the time delay with attaching to the
 // output.
 func (d *DockerEnvironment) Attach() error {
-	if d.attached {
+	if d.IsAttached() {
 		return nil
 	}
 
@@ -404,7 +422,7 @@ func (d *DockerEnvironment) Attach() error {
 	}
 
 	var err error
-	d.stream, err = d.Client.ContainerAttach(context.Background(), d.Server.Uuid, types.ContainerAttachOptions{
+	d.stream, err = d.Client.ContainerAttach(context.Background(), d.Server.Id(), types.ContainerAttachOptions{
 		Stdin:  true,
 		Stdout: true,
 		Stderr: true,
@@ -419,7 +437,7 @@ func (d *DockerEnvironment) Attach() error {
 		Server: d.Server,
 	}
 
-	d.attached = true
+	d.SetAttached(true)
 	go func() {
 		if err := d.EnableResourcePolling(); err != nil {
 			d.Server.Log().WithField("error", errors.WithStack(err)).Warn("failed to enable resource polling on server")
@@ -430,7 +448,7 @@ func (d *DockerEnvironment) Attach() error {
 		defer d.stream.Close()
 		defer func() {
 			d.Server.SetState(ProcessOfflineState)
-			d.attached = false
+			d.SetAttached(false)
 		}()
 
 		io.Copy(console, d.stream.Reader)
@@ -448,7 +466,7 @@ func (d *DockerEnvironment) FollowConsoleOutput() error {
 			return errors.WithStack(err)
 		}
 
-		return errors.New(fmt.Sprintf("no such container: %s", d.Server.Uuid))
+		return errors.New(fmt.Sprintf("no such container: %s", d.Server.Id()))
 	}
 
 	opts := types.ContainerLogsOptions{
@@ -458,7 +476,7 @@ func (d *DockerEnvironment) FollowConsoleOutput() error {
 		Since:      time.Now().Format(time.RFC3339),
 	}
 
-	reader, err := d.Client.ContainerLogs(context.Background(), d.Server.Uuid, opts)
+	reader, err := d.Client.ContainerLogs(context.Background(), d.Server.Id(), opts)
 
 	go func(r io.ReadCloser) {
 		defer r.Close()
@@ -484,7 +502,7 @@ func (d *DockerEnvironment) EnableResourcePolling() error {
 		return errors.New("cannot enable resource polling on a server that is not running")
 	}
 
-	stats, err := d.Client.ContainerStats(context.Background(), d.Server.Uuid, true)
+	stats, err := d.Client.ContainerStats(context.Background(), d.Server.Id(), true)
 	if err != nil {
 		return errors.WithStack(err)
 	}
@@ -621,7 +639,7 @@ func (d *DockerEnvironment) Create() error {
 	// If the container already exists don't hit the user with an error, just return
 	// the current information about it which is what we would do when creating the
 	// container anyways.
-	if _, err := d.Client.ContainerInspect(context.Background(), d.Server.Uuid); err == nil {
+	if _, err := d.Client.ContainerInspect(context.Background(), d.Server.Id()); err == nil {
 		return nil
 	} else if !client.IsErrNotFound(err) {
 		return errors.WithStack(err)
@@ -633,7 +651,7 @@ func (d *DockerEnvironment) Create() error {
 	}
 
 	conf := &container.Config{
-		Hostname:     d.Server.Uuid,
+		Hostname:     d.Server.Id(),
 		Domainname:   config.Get().Docker.Domainname,
 		User:         strconv.Itoa(config.Get().System.User.Uid),
 		AttachStdin:  true,
@@ -685,16 +703,17 @@ func (d *DockerEnvironment) Create() error {
 			break
 		}
 
-		log := log.WithFields(log.Fields{
-			"server":      d.Server.Uuid,
+		logger := log.WithFields(log.Fields{
+			"server":      d.Server.Id(),
 			"source_path": source,
 			"target_path": target,
 			"read_only":   m.ReadOnly,
 		})
+
 		if mounted {
-			log.Debug("attaching mount to server's container")
+			logger.Debug("attaching mount to server's container")
 		} else {
-			log.Warn("skipping mount because it isn't allowed")
+			logger.Warn("skipping mount because it isn't allowed")
 		}
 	}
 
@@ -738,7 +757,7 @@ func (d *DockerEnvironment) Create() error {
 		NetworkMode: container.NetworkMode(config.Get().Docker.Network.Mode),
 	}
 
-	if _, err := d.Client.ContainerCreate(context.Background(), conf, hostConf, nil, d.Server.Uuid); err != nil {
+	if _, err := d.Client.ContainerCreate(context.Background(), conf, hostConf, nil, d.Server.Id()); err != nil {
 		return errors.WithStack(err)
 	}
 
@@ -748,7 +767,7 @@ func (d *DockerEnvironment) Create() error {
 // Sends the specified command to the stdin of the running container instance. There is no
 // confirmation that this data is sent successfully, only that it gets pushed into the stdin.
 func (d *DockerEnvironment) SendCommand(c string) error {
-	if !d.attached {
+	if !d.IsAttached() {
 		return errors.New("attempting to send command to non-attached instance")
 	}
 
@@ -760,7 +779,7 @@ func (d *DockerEnvironment) SendCommand(c string) error {
 // Reads the log file for the server. This does not care if the server is running or not, it will
 // simply try to read the last X bytes of the file and return them.
 func (d *DockerEnvironment) Readlog(len int64) ([]string, error) {
-	j, err := d.Client.ContainerInspect(context.Background(), d.Server.Uuid)
+	j, err := d.Client.ContainerInspect(context.Background(), d.Server.Id())
 	if err != nil {
 		return nil, err
 	}

server/listeners.go

@@ -27,9 +27,11 @@ func (s *Server) onConsoleOutput(data string) {
 	// If the specific line of output is one that would mark the server as started,
 	// set the server to that state. Only do this if the server is not currently stopped
 	// or stopping.
-	if s.GetState() == ProcessStartingState && strings.Contains(data, s.processConfiguration.Startup.Done) {
+	match := s.ProcessConfiguration().Startup.Done
+
+	if s.GetState() == ProcessStartingState && strings.Contains(data, match) {
 		s.Log().WithFields(log.Fields{
-			"match": s.processConfiguration.Startup.Done,
+			"match": match,
 			"against": data,
 		}).Debug("detected server in running state based on console line output")
 
@@ -40,7 +42,8 @@ func (s *Server) onConsoleOutput(data string) {
 	// set the server to be in a stopping state, otherwise crash detection will kick in and
 	// cause the server to unexpectedly restart on the user.
 	if s.IsRunning() {
-		if s.processConfiguration.Stop.Type == api.ProcessStopCommand && data == s.processConfiguration.Stop.Value {
+		stop := s.ProcessConfiguration().Stop
+		if stop.Type == api.ProcessStopCommand && data == stop.Value {
 			s.SetState(ProcessStoppingState)
 		}
 	}

server/process.go

@@ -0,0 +1,10 @@
+package server
+
+import "github.com/pterodactyl/wings/api"
+
+func (s *Server) ProcessConfiguration() *api.ProcessConfiguration {
+	s.RLock()
+	defer s.RUnlock()
+
+	return s.procConfig
+}

server/server.go

@@ -104,7 +104,7 @@ type Server struct {
 	// Defines the process configuration for the server instance. This is dynamically
 	// fetched from the Pterodactyl Server instance each time the server process is
 	// started, and then cached here.
-	processConfiguration *api.ProcessConfiguration
+	procConfig *api.ProcessConfiguration
 
 	// Tracks the installation process for this server and prevents a server from running
 	// two installer processes at the same time. This also allows us to cancel a running
@@ -153,6 +153,13 @@ type BuildSettings struct {
 	Threads string `json:"threads"`
 }
 
+func (s *Server) Id() string {
+	s.RLock()
+	defer s.RUnlock()
+
+	return s.Uuid
+}
+
 // Converts the CPU limit for a server build into a number that can be better understood
 // by the Docker environment. If there is no limit set, return -1 which will indicate to
 // Docker that it has unlimited CPU quota.
@@ -366,7 +373,10 @@ func (s *Server) SyncWithConfiguration(cfg *api.ServerConfigurationResponse) err
 		return errors.WithStack(err)
 	}
 
-	s.processConfiguration = cfg.ProcessConfiguration
+	s.Lock()
+	s.procConfig = cfg.ProcessConfiguration
+	s.Unlock()
+
 	return nil
 }
 

server/update.go

@@ -27,12 +27,14 @@ func (s *Server) UpdateDataStructure(data []byte, background bool) error {
 		return errors.New("attempting to merge a data stack with an invalid UUID")
 	}
 
+	s.Lock()
 	// Merge the new data object that we have received with the existing server data object
 	// and then save it to the disk so it is persistent.
 	if err := mergo.Merge(s, src, mergo.WithOverride); err != nil {
 		return errors.WithStack(err)
 	}
 
+	// Mergo makes that previous lock disappear. Handle that by just re-locking the object.
 	s.Lock()
 	defer s.Unlock()