fix: refactored routing logic (fixes #701)

network/net_gateway.go

@@ -3,46 +3,26 @@
 package network
 
 import (
-	"strings"
-
-	"github.com/bettercap/bettercap/core"
-
-	"github.com/evilsocket/islazy/str"
+	"github.com/bettercap/bettercap/routing"
 )
 
 func FindGateway(iface *Endpoint) (*Endpoint, error) {
-	Debug("FindGateway(%s) [cmd=%v opts=%v parser=%v]", iface.Name(), IPv4RouteCmd, IPv4RouteCmdOpts, IPv4RouteParser)
-
-	output, err := core.Exec(IPv4RouteCmd, IPv4RouteCmdOpts)
+	gateway, err := routing.Gateway(routing.IPv4, iface.Name())
 	if err != nil {
-		Debug("FindGateway(%s): core.Exec failed with %s", err)
 		return nil, err
 	}
 
-	Debug("FindGateway(%s) output:\n%s", iface.Name(), output)
-
-	ifName := iface.Name()
-	for _, line := range strings.Split(output, "\n") {
-		if line = str.Trim(line); strings.Contains(line, ifName) {
-			m := IPv4RouteParser.FindStringSubmatch(line)
-			if len(m) >= IPv4RouteTokens {
-				Debug("FindGateway(%s) line '%s' matched with %v", iface.Name(), line, m)
-				return IPv4RouteIsGateway(ifName, m, func(gateway string) (*Endpoint, error) {
-					if gateway == iface.IpAddress {
-						Debug("gateway is the interface")
-						return iface, nil
-					} else {
-						// we have the address, now we need its mac
-						mac, err := ArpLookup(ifName, gateway, false)
-						if err != nil {
-							return nil, err
-						}
-						Debug("gateway is %s[%s]", gateway, mac)
-						return NewEndpoint(gateway, mac), nil
-					}
-				})
-			}
+	if gateway == iface.IpAddress {
+		Debug("gateway is the interface")
+		return iface, nil
+	} else {
+		// we have the address, now we need its mac
+		mac, err := ArpLookup(iface.Name(), gateway, false)
+		if err != nil {
+			return nil, err
 		}
+		Debug("gateway is %s[%s]", gateway, mac)
+		return NewEndpoint(gateway, mac), nil
 	}
 
 	Debug("FindGateway(%s): nothing found :/", iface.Name())