fix: refactored routing logic (fixes #701)

routing/route.go

@@ -0,0 +1,17 @@
+package routing
+
+type RouteType int
+
+const (
+	IPv4 RouteType = 0
+	IPv6 RouteType = 1
+)
+
+type Route struct {
+	Type        RouteType
+	Default     bool
+	Device      string
+	Destination string
+	Gateway     string
+	Flags       string
+}

routing/tables.go

@@ -0,0 +1,39 @@
+package routing
+
+import "sync"
+
+var (
+	lock  = sync.RWMutex{}
+	table = make([]Route, 0)
+)
+
+func Table() []Route {
+	lock.RLock()
+	defer lock.RUnlock()
+	return table
+}
+
+func Update() ([]Route, error) {
+	lock.Lock()
+	defer lock.Unlock()
+	return update()
+}
+
+func Gateway(ip RouteType, device string) (string, error) {
+	Update()
+
+	lock.RLock()
+	defer lock.RUnlock()
+
+	for _, r := range table {
+		if r.Type == ip {
+			if device == "" || r.Device == device || r.Device == "" /* windows case */ {
+				if r.Default {
+					return r.Gateway, nil
+				}
+			}
+		}
+	}
+
+	return "", nil
+}

routing/update_darwin.go

@@ -0,0 +1,44 @@
+package routing
+
+import (
+	"github.com/bettercap/bettercap/core"
+	"github.com/evilsocket/islazy/str"
+	"regexp"
+	"strings"
+)
+
+var parser = regexp.MustCompile(`^([^\s]+)\s+([^\s]+)\s+([^\s]+)\s+([^\s]+).*$`)
+
+func update() ([]Route, error) {
+	table = make([]Route, 0)
+
+	output, err := core.Exec("netstat", []string{"-n", "-r"})
+	if err != nil {
+		return nil, err
+	}
+
+	for _, line := range strings.Split(output, "\n") {
+		if line = str.Trim(line); len(line) > 0 {
+			matches := parser.FindStringSubmatch(line)
+			if num := len(matches); num == 5 && matches[1] != "Destination" {
+				route := Route{
+					Destination: matches[1],
+					Gateway:     matches[2],
+					Flags:       matches[3],
+					Device:      matches[4],
+					Default:     matches[1] == "default",
+				}
+
+				if strings.ContainsRune(route.Destination, '.') || strings.ContainsRune(route.Gateway, '.') {
+					route.Type = IPv4
+				} else {
+					route.Type = IPv6
+				}
+
+				table = append(table, route)
+			}
+		}
+	}
+
+	return table, nil
+}

routing/update_linux.go

@@ -0,0 +1,45 @@
+package routing
+
+import (
+	"github.com/bettercap/bettercap/core"
+	"github.com/evilsocket/islazy/str"
+	"regexp"
+	"strings"
+)
+
+var parser = regexp.MustCompile(`^(.+)\sdev\s([^\s]+)\s(.+)$`)
+
+func update() ([]Route, error) {
+	table = make([]Route, 0)
+
+	for ip, inet := range map[RouteType]string{IPv4: "inet", IPv6: "inet6"} {
+		output, err := core.Exec("ip", []string{"-f", inet, "route"})
+		if err != nil {
+			return nil, err
+		}
+
+		for _, line := range strings.Split(output, "\n") {
+			if line = str.Trim(line); len(line) > 0 {
+				matches := parser.FindStringSubmatch(line)
+				if num := len(matches); num == 4 {
+					route := Route{
+						Type:        ip,
+						Destination: matches[1],
+						Device:      matches[2],
+						Flags:       matches[3],
+						Default:     strings.Index(matches[1], "default ") == 0,
+					}
+
+					if idx := strings.Index(route.Destination, " via "); idx >= 0 {
+						route.Gateway = route.Destination[idx + len(" via "):]
+						route.Destination = route.Destination[:idx]
+					}
+
+					table = append(table, route)
+				}
+			}
+		}
+	}
+
+	return table, nil
+}

routing/update_windows.go

@@ -0,0 +1,44 @@
+package routing
+
+import (
+	"github.com/bettercap/bettercap/core"
+	"github.com/evilsocket/islazy/str"
+	"regexp"
+	"strings"
+)
+
+var parser = regexp.MustCompile(`^.+\d+\s+([^\s]+)\s+\d+\s+(.+)$`)
+
+func update() ([]Route, error) {
+	table = make([]Route, 0)
+
+	for ip, inet := range map[RouteType]string{IPv4: "ipv4", IPv6: "ipv6"} {
+		output, err := core.Exec("netsh", []string{"interface", inet, "show", "route"})
+		if err != nil {
+			return nil, err
+		}
+
+		for _, line := range strings.Split(output, "\n") {
+			if line = str.Trim(line); len(line) > 0 {
+				matches := parser.FindStringSubmatch(line)
+				if num := len(matches); num == 3 {
+					route := Route{
+						Type:        ip,
+						Destination: matches[1],
+						Device:      matches[2],
+					}
+
+					if route.Destination == "0.0.0.0/0" || route.Destination == "::/0" {
+						route.Default = true
+						route.Gateway = route.Device
+						route.Device = ""
+					}
+
+					table = append(table, route)
+				}
+			}
+		}
+	}
+
+	return table, nil
+}