Files
gluetun/internal/routing/default.go
2022-09-13 17:18:10 -07:00

74 lines
1.9 KiB
Go

package routing
import (
"errors"
"fmt"
"net"
"github.com/qdm12/gluetun/internal/netlink"
)
var (
ErrRouteDefaultNotFound = errors.New("default route not found")
)
type DefaultRoute struct {
NetInterface string
Gateway net.IP
AssignedIP net.IP
Family int
}
func (d DefaultRoute) String() string {
return fmt.Sprintf("interface %s, gateway %s and assigned IP %s",
d.NetInterface, d.Gateway, d.AssignedIP)
}
func (r *Routing) DefaultRoutes() (defaultRoutes []DefaultRoute, err error) {
routes, err := r.netLinker.RouteList(nil, netlink.FAMILY_ALL)
if err != nil {
return nil, fmt.Errorf("cannot list routes: %w", err)
}
for _, route := range routes {
if route.Dst == nil {
defaultRoute := DefaultRoute{
Gateway: route.Gw,
Family: route.Family,
}
linkIndex := route.LinkIndex
link, err := r.netLinker.LinkByIndex(linkIndex)
if err != nil {
return nil, fmt.Errorf("cannot obtain link by index: for default route at index %d: %w", linkIndex, err)
}
attributes := link.Attrs()
defaultRoute.NetInterface = attributes.Name
family := netlink.FAMILY_V6
if route.Gw.To4() != nil {
family = netlink.FAMILY_V4
}
defaultRoute.AssignedIP, err = r.assignedIP(defaultRoute.NetInterface, family)
if err != nil {
return nil, fmt.Errorf("cannot get assigned IP of %s: %w", defaultRoute.NetInterface, err)
}
r.logger.Info("default route found: " + defaultRoute.String())
defaultRoutes = append(defaultRoutes, defaultRoute)
}
}
if len(defaultRoutes) == 0 {
return nil, fmt.Errorf("%w: in %d route(s)", ErrRouteDefaultNotFound, len(routes))
}
return defaultRoutes, nil
}
func DefaultRoutesInterfaces(defaultRoutes []DefaultRoute) (interfaces []string) {
interfaces = make([]string, len(defaultRoutes))
for i := range defaultRoutes {
interfaces[i] = defaultRoutes[i].NetInterface
}
return interfaces
}