Add route management for Android interface (#801)

Support client route management feature on Android

client/internal/routemanager/systemops_nonandroid_test.go

@@ -0,0 +1,116 @@
+package routemanager
+
+import (
+	"fmt"
+	"github.com/netbirdio/netbird/iface"
+	"github.com/pion/transport/v2/stdnet"
+	"github.com/stretchr/testify/require"
+	"net"
+	"net/netip"
+	"testing"
+)
+
+func TestAddRemoveRoutes(t *testing.T) {
+	testCases := []struct {
+		name                   string
+		prefix                 netip.Prefix
+		shouldRouteToWireguard bool
+		shouldBeRemoved        bool
+	}{
+		{
+			name:                   "Should Add And Remove Route",
+			prefix:                 netip.MustParsePrefix("100.66.120.0/24"),
+			shouldRouteToWireguard: true,
+			shouldBeRemoved:        true,
+		},
+		{
+			name:                   "Should Not Add Or Remove Route",
+			prefix:                 netip.MustParsePrefix("127.0.0.1/32"),
+			shouldRouteToWireguard: false,
+			shouldBeRemoved:        false,
+		},
+	}
+
+	for n, testCase := range testCases {
+		t.Run(testCase.name, func(t *testing.T) {
+			newNet, err := stdnet.NewNet()
+			if err != nil {
+				t.Fatal(err)
+			}
+			wgInterface, err := iface.NewWGIFace(fmt.Sprintf("utun53%d", n), "100.65.75.2/24", iface.DefaultMTU, nil, nil, newNet)
+			require.NoError(t, err, "should create testing WGIface interface")
+			defer wgInterface.Close()
+
+			err = wgInterface.Create()
+			require.NoError(t, err, "should create testing wireguard interface")
+
+			err = addToRouteTableIfNoExists(testCase.prefix, wgInterface.Address().IP.String())
+			require.NoError(t, err, "should not return err")
+
+			prefixGateway, err := getExistingRIBRouteGateway(testCase.prefix)
+			require.NoError(t, err, "should not return err")
+			if testCase.shouldRouteToWireguard {
+				require.Equal(t, wgInterface.Address().IP.String(), prefixGateway.String(), "route should point to wireguard interface IP")
+			} else {
+				require.NotEqual(t, wgInterface.Address().IP.String(), prefixGateway.String(), "route should point to a different interface")
+			}
+
+			err = removeFromRouteTableIfNonSystem(testCase.prefix, wgInterface.Address().IP.String())
+			require.NoError(t, err, "should not return err")
+
+			prefixGateway, err = getExistingRIBRouteGateway(testCase.prefix)
+			require.NoError(t, err, "should not return err")
+
+			internetGateway, err := getExistingRIBRouteGateway(netip.MustParsePrefix("0.0.0.0/0"))
+			require.NoError(t, err)
+
+			if testCase.shouldBeRemoved {
+				require.Equal(t, internetGateway, prefixGateway, "route should be pointing to default internet gateway")
+			} else {
+				require.NotEqual(t, internetGateway, prefixGateway, "route should be pointing to a different gateway than the internet gateway")
+			}
+		})
+	}
+}
+
+func TestGetExistingRIBRouteGateway(t *testing.T) {
+	gateway, err := getExistingRIBRouteGateway(netip.MustParsePrefix("0.0.0.0/0"))
+	if err != nil {
+		t.Fatal("shouldn't return error when fetching the gateway: ", err)
+	}
+	if gateway == nil {
+		t.Fatal("should return a gateway")
+	}
+	addresses, err := net.InterfaceAddrs()
+	if err != nil {
+		t.Fatal("shouldn't return error when fetching interface addresses: ", err)
+	}
+
+	var testingIP string
+	var testingPrefix netip.Prefix
+	for _, address := range addresses {
+		if address.Network() != "ip+net" {
+			continue
+		}
+		prefix := netip.MustParsePrefix(address.String())
+		if !prefix.Addr().IsLoopback() && prefix.Addr().Is4() {
+			testingIP = prefix.Addr().String()
+			testingPrefix = prefix.Masked()
+			break
+		}
+	}
+
+	localIP, err := getExistingRIBRouteGateway(testingPrefix)
+	if err != nil {
+		t.Fatal("shouldn't return error: ", err)
+	}
+	if localIP == nil {
+		t.Fatal("should return a gateway for local network")
+	}
+	if localIP.String() == gateway.String() {
+		t.Fatal("local ip should not match with gateway IP")
+	}
+	if localIP.String() != testingIP {
+		t.Fatalf("local ip should match with testing IP: want %s got %s", testingIP, localIP.String())
+	}
+}