Removed interface manipulation via os.Exec into

rtnetlink calls

pkg/mesh/route.go

@@ -1,13 +1,20 @@
 package mesh
 
 import (
+	"fmt"
+	"net"
+
 	"github.com/tim-beatham/wgmesh/pkg/ip"
+	"github.com/tim-beatham/wgmesh/pkg/lib"
 	logging "github.com/tim-beatham/wgmesh/pkg/log"
 	"github.com/tim-beatham/wgmesh/pkg/route"
+	"golang.org/x/sys/unix"
 )
 
 type RouteManager interface {
 	UpdateRoutes() error
+	InstallRoutes() error
+	RemoveRoutes(meshId string) error
 }
 
 type RouteManagerImpl struct {
@@ -49,6 +56,129 @@ func (r *RouteManagerImpl) UpdateRoutes() error {
 	return nil
 }
 
+// removeRoutes: removes all meshes we are no longer a part of
+func (r *RouteManagerImpl) RemoveRoutes(meshId string) error {
+	ulaBuilder := new(ip.ULABuilder)
+	meshes := r.meshManager.GetMeshes()
+
+	ipNet, err := ulaBuilder.GetIPNet(meshId)
+
+	if err != nil {
+		return err
+	}
+
+	for _, mesh1 := range meshes {
+		self, err := r.meshManager.GetSelf(meshId)
+
+		if err != nil {
+			return err
+		}
+
+		mesh1.RemoveRoutes(self.GetHostEndpoint(), ipNet.String())
+	}
+	return nil
+}
+
+// AddRoute adds a route to the given interface
+func (m *RouteManagerImpl) addRoute(ifName string, meshPrefix string, routes ...lib.Route) error {
+	rtnl, err := lib.NewRtNetlinkConfig()
+
+	if err != nil {
+		return fmt.Errorf("failed to create config: %w", err)
+	}
+	defer rtnl.Close()
+
+	// Delete any routes that may be vacant
+	err = rtnl.DeleteRoutes(ifName, unix.AF_INET6, routes...)
+
+	if err != nil {
+		return err
+	}
+
+	for _, route := range routes {
+		if route.Destination.String() == meshPrefix {
+			continue
+		}
+
+		err = rtnl.AddRoute(ifName, route)
+
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (m *RouteManagerImpl) installRoute(ifName string, meshid string, node MeshNode) error {
+	routeMapFunc := func(route string) lib.Route {
+		_, cidr, _ := net.ParseCIDR(route)
+
+		r := lib.Route{
+			Destination: *cidr,
+			Gateway:     node.GetWgHost().IP,
+		}
+		return r
+	}
+
+	ipBuilder := &ip.ULABuilder{}
+	ipNet, err := ipBuilder.GetIPNet(meshid)
+
+	if err != nil {
+		return err
+	}
+
+	routes := lib.Map(append(node.GetRoutes(), ipNet.String()), routeMapFunc)
+	return m.addRoute(ifName, ipNet.String(), routes...)
+}
+
+func (m *RouteManagerImpl) installRoutes(meshProvider MeshProvider) error {
+	mesh, err := meshProvider.GetMesh()
+
+	if err != nil {
+		return err
+	}
+
+	dev, err := meshProvider.GetDevice()
+
+	if err != nil {
+		return err
+	}
+
+	self, err := m.meshManager.GetSelf(meshProvider.GetMeshId())
+
+	if err != nil {
+		return err
+	}
+
+	for _, node := range mesh.GetNodes() {
+		if self.GetHostEndpoint() == node.GetHostEndpoint() {
+			continue
+		}
+
+		err = m.installRoute(dev.Name, meshProvider.GetMeshId(), node)
+
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// InstallRoutes installs all routes to the RIB
+func (r *RouteManagerImpl) InstallRoutes() error {
+	for _, mesh := range r.meshManager.GetMeshes() {
+		err := r.installRoutes(mesh)
+
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
 func NewRouteManager(m MeshManager) RouteManager {
 	return &RouteManagerImpl{meshManager: m, routeInstaller: route.NewRouteInstaller()}
 }