diff options
Diffstat (limited to 'libpod/networking_linux.go')
| -rw-r--r-- | libpod/networking_linux.go | 129 |
1 files changed, 124 insertions, 5 deletions
diff --git a/libpod/networking_linux.go b/libpod/networking_linux.go index 43d0a61a4..f9caf26d1 100644 --- a/libpod/networking_linux.go +++ b/libpod/networking_linux.go @@ -50,7 +50,16 @@ func (r *Runtime) getPodNetwork(id, name, nsPath string, networks []string, port // Create and configure a new network namespace for a container func (r *Runtime) configureNetNS(ctr *Container, ctrNS ns.NetNS) ([]*cnitypes.Result, error) { - podNetwork := r.getPodNetwork(ctr.ID(), ctr.Name(), ctrNS.Path(), ctr.config.Networks, ctr.config.PortMappings, ctr.config.StaticIP) + var requestedIP net.IP + if ctr.requestedIP != nil { + requestedIP = ctr.requestedIP + // cancel request for a specific IP in case the container is reused later + ctr.requestedIP = nil + } else { + requestedIP = ctr.config.StaticIP + } + + podNetwork := r.getPodNetwork(ctr.ID(), ctr.Name(), ctrNS.Path(), ctr.config.Networks, ctr.config.PortMappings, requestedIP) results, err := r.netPlugin.SetUpPod(podNetwork) if err != nil { @@ -112,6 +121,19 @@ func (r *Runtime) createNetNS(ctr *Container) (n ns.NetNS, q []*cnitypes.Result, return ctrNS, networkStatus, err } +type slirp4netnsCmdArg struct { + Proto string `json:"proto,omitempty"` + HostAddr string `json:"host_addr"` + HostPort int32 `json:"host_port"` + GuestAddr string `json:"guest_addr"` + GuestPort int32 `json:"guest_port"` +} + +type slirp4netnsCmd struct { + Execute string `json:"execute"` + Args slirp4netnsCmdArg `json:"arguments"` +} + // Configure the network namespace for a rootless container func (r *Runtime) setupRootlessNetNS(ctr *Container) (err error) { defer ctr.rootlessSlirpSyncR.Close() @@ -130,7 +152,15 @@ func (r *Runtime) setupRootlessNetNS(ctr *Container) (err error) { defer syncR.Close() defer syncW.Close() - cmd := exec.Command(path, "-c", "-e", "3", "-r", "4", fmt.Sprintf("%d", ctr.state.PID), "tap0") + havePortMapping := len(ctr.Config().PortMappings) > 0 + apiSocket := filepath.Join(r.ociRuntime.tmpDir, fmt.Sprintf("%s.net", ctr.config.ID)) + var cmd *exec.Cmd + if havePortMapping { + // if we need ports to be mapped from the host, create a API socket to use for communicating with slirp4netns. + cmd = exec.Command(path, "-c", "-e", "3", "-r", "4", "--api-socket", apiSocket, fmt.Sprintf("%d", ctr.state.PID), "tap0") + } else { + cmd = exec.Command(path, "-c", "-e", "3", "-r", "4", fmt.Sprintf("%d", ctr.state.PID), "tap0") + } cmd.SysProcAttr = &syscall.SysProcAttr{ Setpgid: true, @@ -153,19 +183,99 @@ func (r *Runtime) setupRootlessNetNS(ctr *Container) (err error) { if os.IsTimeout(err) { // Check if the process is still running. var status syscall.WaitStatus - _, err := syscall.Wait4(cmd.Process.Pid, &status, syscall.WNOHANG, nil) + pid, err := syscall.Wait4(cmd.Process.Pid, &status, syscall.WNOHANG, nil) if err != nil { return errors.Wrapf(err, "failed to read slirp4netns process status") } + if pid != cmd.Process.Pid { + continue + } if status.Exited() || status.Signaled() { return errors.New("slirp4netns failed") } - continue } return errors.Wrapf(err, "failed to read from slirp4netns sync pipe") } } + + if havePortMapping { + const pidWaitTimeout = 60 * time.Second + chWait := make(chan error) + go func() { + interval := 25 * time.Millisecond + for i := time.Duration(0); i < pidWaitTimeout; i += interval { + // Check if the process is still running. + var status syscall.WaitStatus + pid, err := syscall.Wait4(cmd.Process.Pid, &status, syscall.WNOHANG, nil) + if err != nil { + break + } + if pid != cmd.Process.Pid { + continue + } + if status.Exited() || status.Signaled() { + chWait <- fmt.Errorf("slirp4netns exited with status %d", status.ExitStatus()) + } + time.Sleep(interval) + } + }() + defer close(chWait) + + // wait that API socket file appears before trying to use it. + if _, err := WaitForFile(apiSocket, chWait, pidWaitTimeout*time.Millisecond); err != nil { + return errors.Wrapf(err, "waiting for slirp4nets to create the api socket file %s", apiSocket) + } + + // for each port we want to add we need to open a connection to the slirp4netns control socket + // and send the add_hostfwd command. + for _, i := range ctr.config.PortMappings { + conn, err := net.Dial("unix", apiSocket) + if err != nil { + return errors.Wrapf(err, "cannot open connection to %s", apiSocket) + } + defer conn.Close() + hostIP := i.HostIP + if hostIP == "" { + hostIP = "0.0.0.0" + } + cmd := slirp4netnsCmd{ + Execute: "add_hostfwd", + Args: slirp4netnsCmdArg{ + Proto: i.Protocol, + HostAddr: hostIP, + HostPort: i.HostPort, + GuestPort: i.ContainerPort, + }, + } + // create the JSON payload and send it. Mark the end of request shutting down writes + // to the socket, as requested by slirp4netns. + data, err := json.Marshal(&cmd) + if err != nil { + return errors.Wrapf(err, "cannot marshal JSON for slirp4netns") + } + if _, err := conn.Write([]byte(fmt.Sprintf("%s\n", data))); err != nil { + return errors.Wrapf(err, "cannot write to control socket %s", apiSocket) + } + if err := conn.(*net.UnixConn).CloseWrite(); err != nil { + return errors.Wrapf(err, "cannot shutdown the socket %s", apiSocket) + } + buf := make([]byte, 2048) + len, err := conn.Read(buf) + if err != nil { + return errors.Wrapf(err, "cannot read from control socket %s", apiSocket) + } + // if there is no 'error' key in the received JSON data, then the operation was + // successful. + var y map[string]interface{} + if err := json.Unmarshal(buf[0:len], &y); err != nil { + return errors.Wrapf(err, "error parsing error status from slirp4netns") + } + if e, found := y["error"]; found { + return errors.Errorf("error from slirp4netns while setting up port redirection: %v", e) + } + } + } return nil } @@ -258,7 +368,16 @@ func (r *Runtime) teardownNetNS(ctr *Container) error { logrus.Debugf("Tearing down network namespace at %s for container %s", ctr.state.NetNS.Path(), ctr.ID()) - podNetwork := r.getPodNetwork(ctr.ID(), ctr.Name(), ctr.state.NetNS.Path(), ctr.config.Networks, ctr.config.PortMappings, ctr.config.StaticIP) + var requestedIP net.IP + if ctr.requestedIP != nil { + requestedIP = ctr.requestedIP + // cancel request for a specific IP in case the container is reused later + ctr.requestedIP = nil + } else { + requestedIP = ctr.config.StaticIP + } + + podNetwork := r.getPodNetwork(ctr.ID(), ctr.Name(), ctr.state.NetNS.Path(), ctr.config.Networks, ctr.config.PortMappings, requestedIP) // The network may have already been torn down, so don't fail here, just log if err := r.netPlugin.TearDownPod(podNetwork); err != nil { |