refact: refactored can dbc logic

modules/can/can.go

@@ -6,7 +6,6 @@ import (
 
 	"github.com/bettercap/bettercap/v2/session"
 	"github.com/hashicorp/go-bexpr"
-	"go.einride.tech/can/pkg/descriptor"
 	"go.einride.tech/can/pkg/socketcan"
 )
 
@@ -17,9 +16,7 @@ type CANModule struct {
 	transport  string
 	filter     string
 	filterExpr *bexpr.Evaluator
-	dbcPath    string
-	dbc        *descriptor.Database
-
+	dbc        *DBC
 	conn       net.Conn
 	recv       *socketcan.Receiver
 	send       *socketcan.Transmitter
@@ -28,8 +25,8 @@ type CANModule struct {
 func NewCanModule(s *session.Session) *CANModule {
 	mod := &CANModule{
 		SessionModule: session.NewSessionModule("can", s),
-		dbcPath:       "",
 		filter:        "",
+		dbc:           &DBC{},
 		filterExpr:    nil,
 		transport:     "can",
 		deviceName:    "can0",
@@ -45,11 +42,6 @@ func NewCanModule(s *session.Session) *CANModule {
 		"",
 		"Network type, can be 'can' for SocketCAN or 'udp'."))
 
-	mod.AddParam(session.NewStringParameter("can.dbc_path",
-		mod.dbcPath,
-		"",
-		"Optional path to DBC file for decoding."))
-
 	mod.AddParam(session.NewStringParameter("can.filter",
 		"",
 		"",
@@ -61,6 +53,18 @@ func NewCanModule(s *session.Session) *CANModule {
 			return mod.Start()
 		}))
 
+	mod.AddHandler(session.NewModuleHandler("can.load_dbc PATH", "",
+		"Start CAN-bus discovery.",
+		func(args []string) error {
+			return mod.Start()
+		}))
+
+	mod.AddHandler(session.NewModuleHandler("can.dbc.load NAME", "can.dbc.load (.+)",
+		"Load a DBC file from the list of available ones or from disk.",
+		func(args []string) error {
+			return mod.dbcLoad(args[0])
+		}))
+
 	mod.AddHandler(session.NewModuleHandler("can.recon off", "",
 		"Stop CAN-bus discovery.",
 		func(args []string) error {

modules/can/can_dbc.go

@@ -0,0 +1,169 @@
+package can
+
+import (
+	"fmt"
+	"os"
+	"sync"
+
+	"github.com/evilsocket/islazy/str"
+	"go.einride.tech/can"
+	"go.einride.tech/can/pkg/descriptor"
+)
+
+type DBC struct {
+	sync.RWMutex
+
+	path string
+	db   *descriptor.Database
+}
+
+func (dbc *DBC) Loaded() bool {
+	dbc.RLock()
+	defer dbc.RUnlock()
+
+	return dbc.db != nil
+}
+
+func (dbc *DBC) LoadFile(mod *CANModule, path string) error {
+	input, err := os.ReadFile(path)
+	if err != nil {
+		return fmt.Errorf("can't read %s: %v", path, err)
+	}
+	return dbc.LoadData(mod, path, input)
+}
+
+func (dbc *DBC) LoadData(mod *CANModule, name string, input []byte) error {
+	dbc.Lock()
+	defer dbc.Unlock()
+
+	mod.Debug("compiling %s ...", name)
+
+	result, err := dbcCompile(name, input)
+	if err != nil {
+		return fmt.Errorf("can't compile %s: %v", name, err)
+	}
+
+	for _, warning := range result.Warnings {
+		mod.Warning("%v", warning)
+	}
+
+	dbc.path = name
+	dbc.db = result.Database
+
+	mod.Info("%s loaded", name)
+	return nil
+}
+
+func (dbc *DBC) Parse(mod *CANModule, frame can.Frame, msg *Message) bool {
+	dbc.RLock()
+	defer dbc.RUnlock()
+
+	// did we load any DBC database?
+	if dbc.db == nil {
+		return false
+	}
+
+	// if the database contains this message id
+	if message, found := dbc.db.Message(frame.ID); found {
+		msg.Name = message.Name
+
+		// find source full info in DBC nodes
+		sourceName := message.SenderNode
+		sourceDesc := ""
+		if sender, found := dbc.db.Node(message.SenderNode); found {
+			sourceName = sender.Name
+			sourceDesc = sender.Description
+		}
+
+		// add CAN source if new
+		_, msg.Source = mod.Session.CAN.AddIfNew(sourceName, sourceDesc, frame.Data[:])
+
+		msg.Signals = make(map[string]string)
+
+		// parse signals
+		for _, signal := range message.Signals {
+			var value string
+
+			if signal.Length <= 32 && signal.IsFloat {
+				value = fmt.Sprintf("%f", signal.UnmarshalFloat(frame.Data))
+			} else if signal.Length == 1 {
+				value = fmt.Sprintf("%v", signal.UnmarshalBool(frame.Data))
+			} else if signal.IsSigned {
+				value = fmt.Sprintf("%d", signal.UnmarshalSigned(frame.Data))
+			} else {
+				value = fmt.Sprintf("%d", signal.UnmarshalUnsigned(frame.Data))
+			}
+
+			msg.Signals[signal.Name] = str.Trim(fmt.Sprintf("%s %s", value, signal.Unit))
+		}
+
+		return true
+	}
+
+	return false
+}
+
+func (dbc *DBC) MessagesBySender(senderId string) []*descriptor.Message {
+	dbc.RLock()
+	defer dbc.RUnlock()
+
+	fromSender := make([]*descriptor.Message, 0)
+
+	if dbc.db == nil {
+		return fromSender
+	}
+
+	for _, msg := range dbc.db.Messages {
+		if msg.SenderNode == senderId {
+			fromSender = append(fromSender, msg)
+		}
+	}
+
+	return fromSender
+}
+
+func (dbc *DBC) MessageById(frameID uint32) *descriptor.Message {
+	dbc.RLock()
+	defer dbc.RUnlock()
+
+	if dbc.db == nil {
+		return nil
+	}
+
+	if message, found := dbc.db.Message(frameID); found {
+		return message
+	}
+	return nil
+}
+
+func (dbc *DBC) Messages() []*descriptor.Message {
+	dbc.RLock()
+	defer dbc.RUnlock()
+
+	if dbc.db == nil {
+		return nil
+	}
+
+	return dbc.db.Messages
+}
+
+func (dbc *DBC) Senders() []string {
+	dbc.RLock()
+	defer dbc.RUnlock()
+
+	senders := make([]string, 0)
+	if dbc.db == nil {
+		return senders
+	}
+
+	uniq := make(map[string]bool)
+	for _, msg := range dbc.db.Messages {
+		uniq[msg.SenderNode] = true
+	}
+
+	for sender, _ := range uniq {
+		senders = append(senders, sender)
+	}
+
+	return senders
+}

modules/can/can_dbc_load.go

@@ -0,0 +1,6 @@
+package can
+
+func (mod *CANModule) dbcLoad(name string) error {
+	// load as file
+	return mod.dbc.LoadFile(mod, name)
+}

modules/can/can_fuzz.go

@@ -10,7 +10,6 @@ import (
 
 	"github.com/dustin/go-humanize"
 	"go.einride.tech/can"
-	"go.einride.tech/can/pkg/descriptor"
 )
 
 func (mod *CANModule) Fuzz(id string) error {
@@ -25,15 +24,9 @@ func (mod *CANModule) Fuzz(id string) error {
 	if err != nil {
 		if mod.dbc != nil {
 			// not a number, use as node name
-			fromSender := make([]*descriptor.Message, 0)
-			for _, msg := range mod.dbc.Messages {
-				if msg.SenderNode == id {
-					fromSender = append(fromSender, msg)
-				}
-			}
-
+			fromSender := mod.dbc.MessagesBySender(id)
 			if len(fromSender) == 0 {
-				return fmt.Errorf("no messages defined in DBC file for node %s", id)
+				return fmt.Errorf("no messages defined in DBC file for node %s, available nodes: %s", id, mod.dbc.Senders())
 			}
 
 			idx := rng.Intn(len(fromSender))
@@ -46,8 +39,8 @@ func (mod *CANModule) Fuzz(id string) error {
 	}
 
 	// if we have a DBC
-	if mod.dbc != nil {
-		if message, found := mod.dbc.Message(uint32(frameID)); found {
+	if mod.dbc.Loaded() {
+		if message := mod.dbc.MessageById(uint32(frameID)); message != nil {
 			mod.Info("found as %s", message.Name)
 
 			dataLen = int(message.Length)
@@ -57,7 +50,7 @@ func (mod *CANModule) Fuzz(id string) error {
 			}
 		} else {
 			avail := []string{}
-			for _, msg := range mod.dbc.Messages {
+			for _, msg := range mod.dbc.Messages() {
 				avail = append(avail, fmt.Sprintf("%d (%s)", msg.ID, msg.Name))
 			}
 			return fmt.Errorf("message with id %d not found in DBC file, available ids: %v", frameID, strings.Join(avail, ", "))
@@ -70,7 +63,7 @@ func (mod *CANModule) Fuzz(id string) error {
 			return err
 		}
 
-		mod.Warning("no can.dbc_path is set, creating frame with %d bytes of random data", dataLen)
+		mod.Warning("no dbc loaded, creating frame with %d bytes of random data", dataLen)
 	}
 
 	frame := can.Frame{

modules/can/can_recon.go

@@ -2,12 +2,9 @@ package can
 
 import (
 	"errors"
-	"fmt"
-	"os"
 
 	"github.com/bettercap/bettercap/v2/network"
 	"github.com/bettercap/bettercap/v2/session"
-	"github.com/evilsocket/islazy/str"
 	"github.com/evilsocket/islazy/tui"
 	"github.com/hashicorp/go-bexpr"
 	"go.einride.tech/can"
@@ -21,28 +18,6 @@ type Message struct {
 	Signals map[string]string
 }
 
-func (mod *CANModule) compileDBC() error {
-	input, err := os.ReadFile(mod.dbcPath)
-	if err != nil {
-		return fmt.Errorf("can't read %s: %v", mod.dbcPath, err)
-	}
-
-	mod.Info("compiling %s ...", mod.dbcPath)
-
-	result, err := dbcCompile(mod.dbcPath, input)
-	if err != nil {
-		return fmt.Errorf("can't compile %s: %v", mod.dbcPath, err)
-	}
-
-	for _, warning := range result.Warnings {
-		mod.Warning("%v", warning)
-	}
-
-	mod.dbc = result.Database
-
-	return nil
-}
-
 func (mod *CANModule) Configure() error {
 	var err error
 
@@ -54,20 +29,10 @@ func (mod *CANModule) Configure() error {
 		return err
 	} else if mod.transport != "can" && mod.transport != "udp" {
 		return errors.New("invalid transport")
-	} else if err, mod.dbcPath = mod.StringParam("can.dbc_path"); err != nil {
-		return err
 	} else if err, mod.filter = mod.StringParam("can.filter"); err != nil {
 		return err
 	}
 
-	if mod.dbcPath != "" {
-		if err := mod.compileDBC(); err != nil {
-			return err
-		}
-	} else {
-		mod.Warning("no can.dbc_path specified, messages won't be parsed")
-	}
-
 	if mod.filter != "" {
 		if mod.filterExpr, err = bexpr.CreateEvaluator(mod.filter); err != nil {
 			return err
@@ -85,49 +50,7 @@ func (mod *CANModule) Configure() error {
 	return nil
 }
 
-func (mod *CANModule) onFrame(frame can.Frame) {
-	msg := Message{
-		Frame: frame,
-	}
-
-	// if we have a DBC database
-	if mod.dbc != nil {
-		// if the database contains this message id
-		if message, found := mod.dbc.Message(frame.ID); found {
-			msg.Name = message.Name
-
-			// find source full info in DBC nodes
-			sourceName := message.SenderNode
-			sourceDesc := ""
-			if sender, found := mod.dbc.Node(message.SenderNode); found {
-				sourceName = sender.Name
-				sourceDesc = sender.Description
-			}
-
-			// add CAN source if new
-			_, msg.Source = mod.Session.CAN.AddIfNew(sourceName, sourceDesc, frame.Data[:])
-
-			msg.Signals = make(map[string]string)
-
-			// parse signals
-			for _, signal := range message.Signals {
-				var value string
-
-				if signal.Length <= 32 && signal.IsFloat {
-					value = fmt.Sprintf("%f", signal.UnmarshalFloat(frame.Data))
-				} else if signal.Length == 1 {
-					value = fmt.Sprintf("%v", signal.UnmarshalBool(frame.Data))
-				} else if signal.IsSigned {
-					value = fmt.Sprintf("%d", signal.UnmarshalSigned(frame.Data))
-				} else {
-					value = fmt.Sprintf("%d", signal.UnmarshalUnsigned(frame.Data))
-				}
-
-				msg.Signals[signal.Name] = str.Trim(fmt.Sprintf("%s %s", value, signal.Unit))
-			}
-		}
-	}
-
+func (mod *CANModule) isFilteredOut(frame can.Frame, msg Message) bool {
 	// if we have an active filter
 	if mod.filter != "" {
 		if res, err := mod.filterExpr.Evaluate(map[string]interface{}{
@@ -137,12 +60,25 @@ func (mod *CANModule) onFrame(frame can.Frame) {
 			mod.Error("error evaluating '%s': %v", mod.filter, err)
 		} else if !res {
 			mod.Debug("skipping can message %+v", msg)
-			return
+			return true
 		}
 	}
 
+	return false
+}
+
+func (mod *CANModule) onFrame(frame can.Frame) {
+	msg := Message{
+		Frame: frame,
+	}
+
+	// try to parse with DBC if we have any
+	mod.dbc.Parse(mod, frame, &msg)
+
+	if !mod.isFilteredOut(frame, msg) {
 		mod.Session.Events.Add("can.message", msg)
 	}
+}
 
 const canPrompt = "{br}{fw}{env.can.device} {fb}{reset} {bold}» {reset}"
 
@@ -173,8 +109,6 @@ func (mod *CANModule) Stop() error {
 			mod.conn = nil
 			mod.recv = nil
 			mod.send = nil
-			mod.dbc = nil
-			mod.dbcPath = ""
 			mod.filter = ""
 		}
 	})