diff options
Diffstat (limited to 'libpod/networking_linux.go')
| -rw-r--r-- | libpod/networking_linux.go | 374 |
1 files changed, 192 insertions, 182 deletions
diff --git a/libpod/networking_linux.go b/libpod/networking_linux.go index 48b0c495c..29fb85556 100644 --- a/libpod/networking_linux.go +++ b/libpod/networking_linux.go @@ -108,7 +108,7 @@ func (r *Runtime) getPodNetwork(id, name, nsPath string, networks []string, port type RootlessCNI struct { ns ns.NetNS dir string - lock lockfile.Locker + Lock lockfile.Locker } // getPath will join the given path to the rootless cni dir @@ -234,16 +234,17 @@ func (r *RootlessCNI) Do(toRun func() error) error { return err } -// Cleanup the rootless cni namespace if needed -// check if we have running containers with the bridge network mode +// Cleanup the rootless cni namespace if needed. +// It checks if we have running containers with the bridge network mode. +// Cleanup() will try to lock RootlessCNI, therefore you have to call it with an unlocked func (r *RootlessCNI) Cleanup(runtime *Runtime) error { _, err := os.Stat(r.dir) if os.IsNotExist(err) { // the directory does not exists no need for cleanup return nil } - r.lock.Lock() - defer r.lock.Unlock() + r.Lock.Lock() + defer r.Lock.Unlock() running := func(c *Container) bool { // we cannot use c.state() because it will try to lock the container // using c.state.State directly should be good enough for this use case @@ -301,205 +302,216 @@ func (r *RootlessCNI) Cleanup(runtime *Runtime) error { // GetRootlessCNINetNs returns the rootless cni object. If create is set to true // the rootless cni namespace will be created if it does not exists already. +// If called as root it returns always nil. +// On success the returned RootlessCNI lock is locked and must be unlocked by the caller. func (r *Runtime) GetRootlessCNINetNs(new bool) (*RootlessCNI, error) { + if !rootless.IsRootless() { + return nil, nil + } var rootlessCNINS *RootlessCNI - if rootless.IsRootless() { - runDir, err := util.GetRuntimeDir() - if err != nil { - return nil, err + runDir, err := util.GetRuntimeDir() + if err != nil { + return nil, err + } + + lfile := filepath.Join(runDir, "rootless-cni.lock") + lock, err := lockfile.GetLockfile(lfile) + if err != nil { + return nil, errors.Wrap(err, "failed to get rootless-cni lockfile") + } + lock.Lock() + defer func() { + // In case of an error (early exit) rootlessCNINS will be nil. + // Make sure to unlock otherwise we could deadlock. + if rootlessCNINS == nil { + lock.Unlock() } - cniDir := filepath.Join(runDir, "rootless-cni") - err = os.MkdirAll(cniDir, 0700) + }() + + cniDir := filepath.Join(runDir, "rootless-cni") + err = os.MkdirAll(cniDir, 0700) + if err != nil { + return nil, errors.Wrap(err, "could not create rootless-cni directory") + } + + nsDir, err := netns.GetNSRunDir() + if err != nil { + return nil, err + } + path := filepath.Join(nsDir, rootlessCNINSName) + ns, err := ns.GetNS(path) + if err != nil { + if !new { + // return a error if we could not get the namespace and should no create one + return nil, errors.Wrap(err, "error getting rootless cni network namespace") + } + // create a new namespace + logrus.Debug("creating rootless cni network namespace") + ns, err = netns.NewNSWithName(rootlessCNINSName) if err != nil { - return nil, errors.Wrap(err, "could not create rootless-cni directory") + return nil, errors.Wrap(err, "error creating rootless cni network namespace") + } + // setup slirp4netns here + path := r.config.Engine.NetworkCmdPath + if path == "" { + var err error + path, err = exec.LookPath("slirp4netns") + if err != nil { + return nil, err + } } - lfile := filepath.Join(cniDir, "rootless-cni.lck") - lock, err := lockfile.GetLockfile(lfile) + syncR, syncW, err := os.Pipe() if err != nil { - return nil, errors.Wrap(err, "failed to get rootless-cni lockfile") + return nil, errors.Wrapf(err, "failed to open pipe") } - lock.Lock() - defer lock.Unlock() + defer errorhandling.CloseQuiet(syncR) + defer errorhandling.CloseQuiet(syncW) - nsDir, err := netns.GetNSRunDir() + netOptions, err := parseSlirp4netnsNetworkOptions(r, nil) if err != nil { return nil, err } - path := filepath.Join(nsDir, rootlessCNINSName) - ns, err := ns.GetNS(path) + slirpFeatures, err := checkSlirpFlags(path) if err != nil { - if new { - // create a new namespace - logrus.Debug("creating rootless cni network namespace") - ns, err = netns.NewNSWithName(rootlessCNINSName) - if err != nil { - return nil, errors.Wrap(err, "error creating rootless cni network namespace") - } - // setup slirp4netns here - path := r.config.Engine.NetworkCmdPath - if path == "" { - var err error - path, err = exec.LookPath("slirp4netns") - if err != nil { - return nil, err - } - } - - syncR, syncW, err := os.Pipe() - if err != nil { - return nil, errors.Wrapf(err, "failed to open pipe") - } - defer errorhandling.CloseQuiet(syncR) - defer errorhandling.CloseQuiet(syncW) - - netOptions, err := parseSlirp4netnsNetworkOptions(r, nil) - if err != nil { - return nil, err - } - slirpFeatures, err := checkSlirpFlags(path) - if err != nil { - return nil, errors.Wrapf(err, "error checking slirp4netns binary %s: %q", path, err) - } - cmdArgs, err := createBasicSlirp4netnsCmdArgs(netOptions, slirpFeatures) - if err != nil { - return nil, err - } - // Note we do not use --exit-fd, we kill this process by pid - cmdArgs = append(cmdArgs, "-c", "-r", "3") - cmdArgs = append(cmdArgs, "--netns-type=path", ns.Path(), "tap0") - - cmd := exec.Command(path, cmdArgs...) - logrus.Debugf("slirp4netns command: %s", strings.Join(cmd.Args, " ")) - cmd.SysProcAttr = &syscall.SysProcAttr{ - Setpgid: true, - } - - // workaround for https://github.com/rootless-containers/slirp4netns/pull/153 - if !netOptions.noPivotRoot && slirpFeatures.HasEnableSandbox { - cmd.SysProcAttr.Cloneflags = syscall.CLONE_NEWNS - cmd.SysProcAttr.Unshareflags = syscall.CLONE_NEWNS - } - - // Leak one end of the pipe in slirp4netns - cmd.ExtraFiles = append(cmd.ExtraFiles, syncW) + return nil, errors.Wrapf(err, "error checking slirp4netns binary %s: %q", path, err) + } + cmdArgs, err := createBasicSlirp4netnsCmdArgs(netOptions, slirpFeatures) + if err != nil { + return nil, err + } + // Note we do not use --exit-fd, we kill this process by pid + cmdArgs = append(cmdArgs, "-c", "-r", "3") + cmdArgs = append(cmdArgs, "--netns-type=path", ns.Path(), "tap0") + + cmd := exec.Command(path, cmdArgs...) + logrus.Debugf("slirp4netns command: %s", strings.Join(cmd.Args, " ")) + cmd.SysProcAttr = &syscall.SysProcAttr{ + Setpgid: true, + } - logPath := filepath.Join(r.config.Engine.TmpDir, "slirp4netns-rootless-cni.log") - logFile, err := os.Create(logPath) - if err != nil { - return nil, errors.Wrapf(err, "failed to open slirp4netns log file %s", logPath) - } - defer logFile.Close() - // Unlink immediately the file so we won't need to worry about cleaning it up later. - // It is still accessible through the open fd logFile. - if err := os.Remove(logPath); err != nil { - return nil, errors.Wrapf(err, "delete file %s", logPath) - } - cmd.Stdout = logFile - cmd.Stderr = logFile - if err := cmd.Start(); err != nil { - return nil, errors.Wrapf(err, "failed to start slirp4netns process") - } - // create pid file for the slirp4netns process - // this is need to kill the process in the cleanup - pid := strconv.Itoa(cmd.Process.Pid) - err = ioutil.WriteFile(filepath.Join(cniDir, "rootless-cni-slirp4netns.pid"), []byte(pid), 0700) - if err != nil { - errors.Wrap(err, "unable to write rootless-cni slirp4netns pid file") - } + // workaround for https://github.com/rootless-containers/slirp4netns/pull/153 + if !netOptions.noPivotRoot && slirpFeatures.HasEnableSandbox { + cmd.SysProcAttr.Cloneflags = syscall.CLONE_NEWNS + cmd.SysProcAttr.Unshareflags = syscall.CLONE_NEWNS + } - defer func() { - if err := cmd.Process.Release(); err != nil { - logrus.Errorf("unable to release command process: %q", err) - } - }() + // Leak one end of the pipe in slirp4netns + cmd.ExtraFiles = append(cmd.ExtraFiles, syncW) - if err := waitForSync(syncR, cmd, logFile, 1*time.Second); err != nil { - return nil, err - } + logPath := filepath.Join(r.config.Engine.TmpDir, "slirp4netns-rootless-cni.log") + logFile, err := os.Create(logPath) + if err != nil { + return nil, errors.Wrapf(err, "failed to open slirp4netns log file %s", logPath) + } + defer logFile.Close() + // Unlink immediately the file so we won't need to worry about cleaning it up later. + // It is still accessible through the open fd logFile. + if err := os.Remove(logPath); err != nil { + return nil, errors.Wrapf(err, "delete file %s", logPath) + } + cmd.Stdout = logFile + cmd.Stderr = logFile + if err := cmd.Start(); err != nil { + return nil, errors.Wrapf(err, "failed to start slirp4netns process") + } + // create pid file for the slirp4netns process + // this is need to kill the process in the cleanup + pid := strconv.Itoa(cmd.Process.Pid) + err = ioutil.WriteFile(filepath.Join(cniDir, "rootless-cni-slirp4netns.pid"), []byte(pid), 0700) + if err != nil { + errors.Wrap(err, "unable to write rootless-cni slirp4netns pid file") + } - // build a new resolv.conf file which uses the slirp4netns dns server address - resolveIP, err := GetSlirp4netnsDNS(nil) - if err != nil { - return nil, errors.Wrap(err, "failed to determine default slirp4netns DNS address") - } + defer func() { + if err := cmd.Process.Release(); err != nil { + logrus.Errorf("unable to release command process: %q", err) + } + }() - if netOptions.cidr != "" { - _, cidr, err := net.ParseCIDR(netOptions.cidr) - if err != nil { - return nil, errors.Wrap(err, "failed to parse slirp4netns cidr") - } - resolveIP, err = GetSlirp4netnsDNS(cidr) - if err != nil { - return nil, errors.Wrapf(err, "failed to determine slirp4netns DNS address from cidr: %s", cidr.String()) - } - } - conf, err := resolvconf.Get() - if err != nil { - return nil, err - } - conf, err = resolvconf.FilterResolvDNS(conf.Content, netOptions.enableIPv6, true) - if err != nil { - return nil, err - } - searchDomains := resolvconf.GetSearchDomains(conf.Content) - dnsOptions := resolvconf.GetOptions(conf.Content) - nameServers := resolvconf.GetNameservers(conf.Content) + if err := waitForSync(syncR, cmd, logFile, 1*time.Second); err != nil { + return nil, err + } - _, err = resolvconf.Build(filepath.Join(cniDir, "resolv.conf"), append([]string{resolveIP.String()}, nameServers...), searchDomains, dnsOptions) - if err != nil { - return nil, errors.Wrap(err, "failed to create rootless cni resolv.conf") - } + // build a new resolv.conf file which uses the slirp4netns dns server address + resolveIP, err := GetSlirp4netnsDNS(nil) + if err != nil { + return nil, errors.Wrap(err, "failed to determine default slirp4netns DNS address") + } - // create cni directories to store files - // they will be bind mounted to the correct location in a extra mount ns - err = os.MkdirAll(filepath.Join(cniDir, strings.TrimPrefix(persistentCNIDir, "/")), 0700) - if err != nil { - return nil, errors.Wrap(err, "could not create rootless-cni var directory") - } - runDir := filepath.Join(cniDir, "run") - err = os.MkdirAll(runDir, 0700) - if err != nil { - return nil, errors.Wrap(err, "could not create rootless-cni run directory") - } - // relabel the new run directory to the iptables /run label - // this is important, otherwise the iptables command will fail - err = label.Relabel(runDir, "system_u:object_r:iptables_var_run_t:s0", false) - if err != nil { - return nil, errors.Wrap(err, "could not create relabel rootless-cni run directory") - } - // create systemd run directory - err = os.MkdirAll(filepath.Join(runDir, "systemd"), 0700) - if err != nil { - return nil, errors.Wrap(err, "could not create rootless-cni systemd directory") - } - // create the directory for the netns files at the same location - // relative to the rootless-cni location - err = os.MkdirAll(filepath.Join(cniDir, nsDir), 0700) - if err != nil { - return nil, errors.Wrap(err, "could not create rootless-cni netns directory") - } - } else { - // return a error if we could not get the namespace and should no create one - return nil, errors.Wrap(err, "error getting rootless cni network namespace") + if netOptions.cidr != "" { + _, cidr, err := net.ParseCIDR(netOptions.cidr) + if err != nil { + return nil, errors.Wrap(err, "failed to parse slirp4netns cidr") + } + resolveIP, err = GetSlirp4netnsDNS(cidr) + if err != nil { + return nil, errors.Wrapf(err, "failed to determine slirp4netns DNS address from cidr: %s", cidr.String()) } } + conf, err := resolvconf.Get() + if err != nil { + return nil, err + } + conf, err = resolvconf.FilterResolvDNS(conf.Content, netOptions.enableIPv6, true) + if err != nil { + return nil, err + } + searchDomains := resolvconf.GetSearchDomains(conf.Content) + dnsOptions := resolvconf.GetOptions(conf.Content) + nameServers := resolvconf.GetNameservers(conf.Content) - // The CNI plugins need access to iptables in $PATH. As it turns out debian doesn't put - // /usr/sbin in $PATH for rootless users. This will break rootless cni completely. - // We might break existing users and we cannot expect everyone to change their $PATH so - // lets add /usr/sbin to $PATH ourselves. - path = os.Getenv("PATH") - if !strings.Contains(path, "/usr/sbin") { - path = path + ":/usr/sbin" - os.Setenv("PATH", path) + _, err = resolvconf.Build(filepath.Join(cniDir, "resolv.conf"), append([]string{resolveIP.String()}, nameServers...), searchDomains, dnsOptions) + if err != nil { + return nil, errors.Wrap(err, "failed to create rootless cni resolv.conf") } - rootlessCNINS = &RootlessCNI{ - ns: ns, - dir: cniDir, - lock: lock, + // create cni directories to store files + // they will be bind mounted to the correct location in a extra mount ns + err = os.MkdirAll(filepath.Join(cniDir, strings.TrimPrefix(persistentCNIDir, "/")), 0700) + if err != nil { + return nil, errors.Wrap(err, "could not create rootless-cni var directory") + } + runDir := filepath.Join(cniDir, "run") + err = os.MkdirAll(runDir, 0700) + if err != nil { + return nil, errors.Wrap(err, "could not create rootless-cni run directory") + } + // relabel the new run directory to the iptables /run label + // this is important, otherwise the iptables command will fail + err = label.Relabel(runDir, "system_u:object_r:iptables_var_run_t:s0", false) + if err != nil { + return nil, errors.Wrap(err, "could not create relabel rootless-cni run directory") + } + // create systemd run directory + err = os.MkdirAll(filepath.Join(runDir, "systemd"), 0700) + if err != nil { + return nil, errors.Wrap(err, "could not create rootless-cni systemd directory") } + // create the directory for the netns files at the same location + // relative to the rootless-cni location + err = os.MkdirAll(filepath.Join(cniDir, nsDir), 0700) + if err != nil { + return nil, errors.Wrap(err, "could not create rootless-cni netns directory") + } + } + + // The CNI plugins need access to iptables in $PATH. As it turns out debian doesn't put + // /usr/sbin in $PATH for rootless users. This will break rootless cni completely. + // We might break existing users and we cannot expect everyone to change their $PATH so + // lets add /usr/sbin to $PATH ourselves. + path = os.Getenv("PATH") + if !strings.Contains(path, "/usr/sbin") { + path = path + ":/usr/sbin" + os.Setenv("PATH", path) + } + + // Important set rootlessCNINS as last step. + // Do not return any errors after this. + rootlessCNINS = &RootlessCNI{ + ns: ns, + dir: cniDir, + Lock: lock, } return rootlessCNINS, nil } @@ -548,9 +560,8 @@ func (r *Runtime) setUpOCICNIPod(podNetwork ocicni.PodNetwork) ([]ocicni.NetResu // rootlessCNINS is nil if we are root if rootlessCNINS != nil { // execute the cni setup in the rootless net ns - rootlessCNINS.lock.Lock() err = rootlessCNINS.Do(setUpPod) - rootlessCNINS.lock.Unlock() + rootlessCNINS.Lock.Unlock() } else { err = setUpPod() } @@ -762,9 +773,8 @@ func (r *Runtime) teardownOCICNIPod(podNetwork ocicni.PodNetwork) error { // rootlessCNINS is nil if we are root if rootlessCNINS != nil { // execute the cni setup in the rootless net ns - rootlessCNINS.lock.Lock() err = rootlessCNINS.Do(tearDownPod) - rootlessCNINS.lock.Unlock() + rootlessCNINS.Lock.Unlock() if err == nil { err = rootlessCNINS.Cleanup(r) } |