package libnetwork import ( "fmt" "github.com/docker/libnetwork/types" ) const ( libnGWNetwork = "docker_gwbridge" gwEPlen = 12 ) var procGwNetwork = make(chan (bool), 1) /* libnetwork creates a bridge network "docker_gw_bridge" for provding default gateway for the containers if none of the container's endpoints have GW set by the driver. ICC is set to false for the GW_bridge network. If a driver can't provide external connectivity it can choose to not set the GW IP for the endpoint. endpoint on the GW_bridge network is managed dynamically by libnetwork. ie: - its created when an endpoint without GW joins the container - its deleted when an endpoint with GW joins the container */ func (sb *sandbox) setupDefaultGW() error { // check if the conitainer already has a GW endpoint if ep := sb.getEndpointInGWNetwork(); ep != nil { return nil } c := sb.controller // Look for default gw network. In case of error (includes not found), // retry and create it if needed in a serialized execution. n, err := c.NetworkByName(libnGWNetwork) if err != nil { if n, err = c.defaultGwNetwork(); err != nil { return err } } createOptions := []EndpointOption{CreateOptionAnonymous()} eplen := gwEPlen if len(sb.containerID) < gwEPlen { eplen = len(sb.containerID) } newEp, err := n.CreateEndpoint("gateway_"+sb.containerID[0:eplen], createOptions...) if err != nil { return fmt.Errorf("container %s: endpoint create on GW Network failed: %v", sb.containerID, err) } epLocal := newEp.(*endpoint) if err := epLocal.sbJoin(sb); err != nil { return fmt.Errorf("container %s: endpoint join on GW Network failed: %v", sb.containerID, err) } return nil } // If present, detach and remove the endpoint connecting the sandbox to the default gw network. func (sb *sandbox) clearDefaultGW() error { var ep *endpoint if ep = sb.getEndpointInGWNetwork(); ep == nil { return nil } if err := ep.sbLeave(sb, false); err != nil { return fmt.Errorf("container %s: endpoint leaving GW Network failed: %v", sb.containerID, err) } if err := ep.Delete(false); err != nil { return fmt.Errorf("container %s: deleting endpoint on GW Network failed: %v", sb.containerID, err) } return nil } // Evaluate whether the sandbox requires a default gateway based // on the endpoints to which it is connected. It does not account // for the default gateway network endpoint. func (sb *sandbox) needDefaultGW() bool { var needGW bool for _, ep := range sb.getConnectedEndpoints() { if ep.endpointInGWNetwork() { continue } if ep.getNetwork().Type() == "null" || ep.getNetwork().Type() == "host" { continue } if ep.getNetwork().Internal() { continue } // During stale sandbox cleanup, joinInfo may be nil if ep.joinInfo != nil && ep.joinInfo.disableGatewayService { continue } // TODO v6 needs to be handled. if len(ep.Gateway()) > 0 { return false } for _, r := range ep.StaticRoutes() { if r.Destination.String() == "0.0.0.0/0" { return false } } needGW = true } return needGW } func (sb *sandbox) getEndpointInGWNetwork() *endpoint { for _, ep := range sb.getConnectedEndpoints() { if ep.getNetwork().name == libnGWNetwork { return ep } } return nil } func (ep *endpoint) endpointInGWNetwork() bool { if ep.getNetwork().name == libnGWNetwork { return true } return false } func (sb *sandbox) getEPwithoutGateway() *endpoint { for _, ep := range sb.getConnectedEndpoints() { if ep.getNetwork().Type() == "null" || ep.getNetwork().Type() == "host" { continue } if len(ep.Gateway()) == 0 { return ep } } return nil } // Looks for the default gw network and creates it if not there. // Parallel executions are serialized. func (c *controller) defaultGwNetwork() (Network, error) { procGwNetwork <- true defer func() { <-procGwNetwork }() n, err := c.NetworkByName(libnGWNetwork) if err != nil { if _, ok := err.(types.NotFoundError); ok { n, err = c.createGWNetwork() } } return n, err } // Returns the endpoint which is providing external connectivity to the sandbox func (sb *sandbox) getGatewayEndpoint() *endpoint { for _, ep := range sb.getConnectedEndpoints() { if ep.getNetwork().Type() == "null" || ep.getNetwork().Type() == "host" { continue } if len(ep.Gateway()) != 0 { return ep } } return nil }