// +build linux // Package specconv implements conversion of specifications to libcontainer // configurations package specconv import ( "fmt" "os" "path/filepath" "strings" "time" "github.com/opencontainers/runc/libcontainer/configs" "github.com/opencontainers/runc/libcontainer/seccomp" libcontainerUtils "github.com/opencontainers/runc/libcontainer/utils" "github.com/opencontainers/runtime-spec/specs-go" "golang.org/x/sys/unix" ) const wildcard = -1 var namespaceMapping = map[specs.LinuxNamespaceType]configs.NamespaceType{ specs.PIDNamespace: configs.NEWPID, specs.NetworkNamespace: configs.NEWNET, specs.MountNamespace: configs.NEWNS, specs.UserNamespace: configs.NEWUSER, specs.IPCNamespace: configs.NEWIPC, specs.UTSNamespace: configs.NEWUTS, } var mountPropagationMapping = map[string]int{ "rprivate": unix.MS_PRIVATE | unix.MS_REC, "private": unix.MS_PRIVATE, "rslave": unix.MS_SLAVE | unix.MS_REC, "slave": unix.MS_SLAVE, "rshared": unix.MS_SHARED | unix.MS_REC, "shared": unix.MS_SHARED, "": unix.MS_PRIVATE | unix.MS_REC, } var allowedDevices = []*configs.Device{ // allow mknod for any device { Type: 'c', Major: wildcard, Minor: wildcard, Permissions: "m", Allow: true, }, { Type: 'b', Major: wildcard, Minor: wildcard, Permissions: "m", Allow: true, }, { Type: 'c', Path: "/dev/null", Major: 1, Minor: 3, Permissions: "rwm", Allow: true, }, { Type: 'c', Path: "/dev/random", Major: 1, Minor: 8, Permissions: "rwm", Allow: true, }, { Type: 'c', Path: "/dev/full", Major: 1, Minor: 7, Permissions: "rwm", Allow: true, }, { Type: 'c', Path: "/dev/tty", Major: 5, Minor: 0, Permissions: "rwm", Allow: true, }, { Type: 'c', Path: "/dev/zero", Major: 1, Minor: 5, Permissions: "rwm", Allow: true, }, { Type: 'c', Path: "/dev/urandom", Major: 1, Minor: 9, Permissions: "rwm", Allow: true, }, { Path: "/dev/console", Type: 'c', Major: 5, Minor: 1, Permissions: "rwm", Allow: true, }, // /dev/pts/ - pts namespaces are "coming soon" { Path: "", Type: 'c', Major: 136, Minor: wildcard, Permissions: "rwm", Allow: true, }, { Path: "", Type: 'c', Major: 5, Minor: 2, Permissions: "rwm", Allow: true, }, // tuntap { Path: "", Type: 'c', Major: 10, Minor: 200, Permissions: "rwm", Allow: true, }, } type CreateOpts struct { CgroupName string UseSystemdCgroup bool NoPivotRoot bool NoNewKeyring bool Spec *specs.Spec Rootless bool } // CreateLibcontainerConfig creates a new libcontainer configuration from a // given specification and a cgroup name func CreateLibcontainerConfig(opts *CreateOpts) (*configs.Config, error) { // runc's cwd will always be the bundle path rcwd, err := os.Getwd() if err != nil { return nil, err } cwd, err := filepath.Abs(rcwd) if err != nil { return nil, err } spec := opts.Spec if spec.Root == nil { return nil, fmt.Errorf("Root must be specified") } rootfsPath := spec.Root.Path if !filepath.IsAbs(rootfsPath) { rootfsPath = filepath.Join(cwd, rootfsPath) } labels := []string{} for k, v := range spec.Annotations { labels = append(labels, fmt.Sprintf("%s=%s", k, v)) } config := &configs.Config{ Rootfs: rootfsPath, NoPivotRoot: opts.NoPivotRoot, Readonlyfs: spec.Root.Readonly, Hostname: spec.Hostname, Labels: append(labels, fmt.Sprintf("bundle=%s", cwd)), NoNewKeyring: opts.NoNewKeyring, Rootless: opts.Rootless, } exists := false if config.RootPropagation, exists = mountPropagationMapping[spec.Linux.RootfsPropagation]; !exists { return nil, fmt.Errorf("rootfsPropagation=%v is not supported", spec.Linux.RootfsPropagation) } for _, ns := range spec.Linux.Namespaces { t, exists := namespaceMapping[ns.Type] if !exists { return nil, fmt.Errorf("namespace %q does not exist", ns) } if config.Namespaces.Contains(t) { return nil, fmt.Errorf("malformed spec file: duplicated ns %q", ns) } config.Namespaces.Add(t, ns.Path) } if config.Namespaces.Contains(configs.NEWNET) { config.Networks = []*configs.Network{ { Type: "loopback", }, } } for _, m := range spec.Mounts { config.Mounts = append(config.Mounts, createLibcontainerMount(cwd, m)) } if err := createDevices(spec, config); err != nil { return nil, err } if err := setupUserNamespace(spec, config); err != nil { return nil, err } c, err := createCgroupConfig(opts) if err != nil { return nil, err } config.Cgroups = c // set extra path masking for libcontainer for the various unsafe places in proc config.MaskPaths = spec.Linux.MaskedPaths config.ReadonlyPaths = spec.Linux.ReadonlyPaths if spec.Linux.Seccomp != nil { seccomp, err := setupSeccomp(spec.Linux.Seccomp) if err != nil { return nil, err } config.Seccomp = seccomp } if spec.Process.SelinuxLabel != "" { config.ProcessLabel = spec.Process.SelinuxLabel } config.Sysctl = spec.Linux.Sysctl if spec.Process != nil && spec.Process.OOMScoreAdj != nil { config.OomScoreAdj = *spec.Process.OOMScoreAdj } if spec.Process.Capabilities != nil { config.Capabilities = &configs.Capabilities{ Bounding: spec.Process.Capabilities.Bounding, Effective: spec.Process.Capabilities.Effective, Permitted: spec.Process.Capabilities.Permitted, Inheritable: spec.Process.Capabilities.Inheritable, Ambient: spec.Process.Capabilities.Ambient, } } createHooks(spec, config) config.MountLabel = spec.Linux.MountLabel config.Version = specs.Version return config, nil } func createLibcontainerMount(cwd string, m specs.Mount) *configs.Mount { flags, pgflags, data, ext := parseMountOptions(m.Options) source := m.Source if m.Type == "bind" { if !filepath.IsAbs(source) { source = filepath.Join(cwd, m.Source) } } return &configs.Mount{ Device: m.Type, Source: source, Destination: m.Destination, Data: data, Flags: flags, PropagationFlags: pgflags, Extensions: ext, } } func createCgroupConfig(opts *CreateOpts) (*configs.Cgroup, error) { var ( myCgroupPath string spec = opts.Spec useSystemdCgroup = opts.UseSystemdCgroup name = opts.CgroupName ) c := &configs.Cgroup{ Resources: &configs.Resources{}, } if spec.Linux != nil && spec.Linux.CgroupsPath != "" { myCgroupPath = libcontainerUtils.CleanPath(spec.Linux.CgroupsPath) if useSystemdCgroup { myCgroupPath = spec.Linux.CgroupsPath } } if useSystemdCgroup { if myCgroupPath == "" { c.Parent = "system.slice" c.ScopePrefix = "runc" c.Name = name } else { // Parse the path from expected "slice:prefix:name" // for e.g. "system.slice:docker:1234" parts := strings.Split(myCgroupPath, ":") if len(parts) != 3 { return nil, fmt.Errorf("expected cgroupsPath to be of format \"slice:prefix:name\" for systemd cgroups") } c.Parent = parts[0] c.ScopePrefix = parts[1] c.Name = parts[2] } } else { if myCgroupPath == "" { c.Name = name } c.Path = myCgroupPath } // In rootless containers, any attempt to make cgroup changes will fail. // libcontainer will validate this and we shouldn't add any cgroup options // the user didn't specify. if !opts.Rootless { c.Resources.AllowedDevices = allowedDevices if spec.Linux == nil { return c, nil } } r := spec.Linux.Resources if r == nil { return c, nil } for i, d := range spec.Linux.Resources.Devices { var ( t = "a" major = int64(-1) minor = int64(-1) ) if d.Type != "" { t = d.Type } if d.Major != nil { major = *d.Major } if d.Minor != nil { minor = *d.Minor } if d.Access == "" { return nil, fmt.Errorf("device access at %d field cannot be empty", i) } dt, err := stringToCgroupDeviceRune(t) if err != nil { return nil, err } dd := &configs.Device{ Type: dt, Major: major, Minor: minor, Permissions: d.Access, Allow: d.Allow, } c.Resources.Devices = append(c.Resources.Devices, dd) } if !opts.Rootless { // append the default allowed devices to the end of the list c.Resources.Devices = append(c.Resources.Devices, allowedDevices...) } if r.Memory != nil { if r.Memory.Limit != nil { c.Resources.Memory = *r.Memory.Limit } if r.Memory.Reservation != nil { c.Resources.MemoryReservation = *r.Memory.Reservation } if r.Memory.Swap != nil { c.Resources.MemorySwap = *r.Memory.Swap } if r.Memory.Kernel != nil { c.Resources.KernelMemory = *r.Memory.Kernel } if r.Memory.KernelTCP != nil { c.Resources.KernelMemoryTCP = *r.Memory.KernelTCP } if r.Memory.Swappiness != nil { c.Resources.MemorySwappiness = r.Memory.Swappiness } if r.Memory.DisableOOMKiller != nil { c.Resources.OomKillDisable = *r.Memory.DisableOOMKiller } } if r.CPU != nil { if r.CPU.Shares != nil { c.Resources.CpuShares = *r.CPU.Shares } if r.CPU.Quota != nil { c.Resources.CpuQuota = *r.CPU.Quota } if r.CPU.Period != nil { c.Resources.CpuPeriod = *r.CPU.Period } if r.CPU.RealtimeRuntime != nil { c.Resources.CpuRtRuntime = *r.CPU.RealtimeRuntime } if r.CPU.RealtimePeriod != nil { c.Resources.CpuRtPeriod = *r.CPU.RealtimePeriod } if r.CPU.Cpus != "" { c.Resources.CpusetCpus = r.CPU.Cpus } if r.CPU.Mems != "" { c.Resources.CpusetMems = r.CPU.Mems } } if r.Pids != nil { c.Resources.PidsLimit = r.Pids.Limit } if r.BlockIO != nil { if r.BlockIO.Weight != nil { c.Resources.BlkioWeight = *r.BlockIO.Weight } if r.BlockIO.LeafWeight != nil { c.Resources.BlkioLeafWeight = *r.BlockIO.LeafWeight } if r.BlockIO.WeightDevice != nil { for _, wd := range r.BlockIO.WeightDevice { var weight, leafWeight uint16 if wd.Weight != nil { weight = *wd.Weight } if wd.LeafWeight != nil { leafWeight = *wd.LeafWeight } weightDevice := configs.NewWeightDevice(wd.Major, wd.Minor, weight, leafWeight) c.Resources.BlkioWeightDevice = append(c.Resources.BlkioWeightDevice, weightDevice) } } if r.BlockIO.ThrottleReadBpsDevice != nil { for _, td := range r.BlockIO.ThrottleReadBpsDevice { rate := td.Rate throttleDevice := configs.NewThrottleDevice(td.Major, td.Minor, rate) c.Resources.BlkioThrottleReadBpsDevice = append(c.Resources.BlkioThrottleReadBpsDevice, throttleDevice) } } if r.BlockIO.ThrottleWriteBpsDevice != nil { for _, td := range r.BlockIO.ThrottleWriteBpsDevice { rate := td.Rate throttleDevice := configs.NewThrottleDevice(td.Major, td.Minor, rate) c.Resources.BlkioThrottleWriteBpsDevice = append(c.Resources.BlkioThrottleWriteBpsDevice, throttleDevice) } } if r.BlockIO.ThrottleReadIOPSDevice != nil { for _, td := range r.BlockIO.ThrottleReadIOPSDevice { rate := td.Rate throttleDevice := configs.NewThrottleDevice(td.Major, td.Minor, rate) c.Resources.BlkioThrottleReadIOPSDevice = append(c.Resources.BlkioThrottleReadIOPSDevice, throttleDevice) } } if r.BlockIO.ThrottleWriteIOPSDevice != nil { for _, td := range r.BlockIO.ThrottleWriteIOPSDevice { rate := td.Rate throttleDevice := configs.NewThrottleDevice(td.Major, td.Minor, rate) c.Resources.BlkioThrottleWriteIOPSDevice = append(c.Resources.BlkioThrottleWriteIOPSDevice, throttleDevice) } } } for _, l := range r.HugepageLimits { c.Resources.HugetlbLimit = append(c.Resources.HugetlbLimit, &configs.HugepageLimit{ Pagesize: l.Pagesize, Limit: l.Limit, }) } if r.Network != nil { if r.Network.ClassID != nil { c.Resources.NetClsClassid = *r.Network.ClassID } for _, m := range r.Network.Priorities { c.Resources.NetPrioIfpriomap = append(c.Resources.NetPrioIfpriomap, &configs.IfPrioMap{ Interface: m.Name, Priority: int64(m.Priority), }) } } return c, nil } func stringToCgroupDeviceRune(s string) (rune, error) { switch s { case "a": return 'a', nil case "b": return 'b', nil case "c": return 'c', nil default: return 0, fmt.Errorf("invalid cgroup device type %q", s) } } func stringToDeviceRune(s string) (rune, error) { switch s { case "p": return 'p', nil case "u": return 'u', nil case "b": return 'b', nil case "c": return 'c', nil default: return 0, fmt.Errorf("invalid device type %q", s) } } func createDevices(spec *specs.Spec, config *configs.Config) error { // add whitelisted devices config.Devices = []*configs.Device{ { Type: 'c', Path: "/dev/null", Major: 1, Minor: 3, FileMode: 0666, Uid: 0, Gid: 0, }, { Type: 'c', Path: "/dev/random", Major: 1, Minor: 8, FileMode: 0666, Uid: 0, Gid: 0, }, { Type: 'c', Path: "/dev/full", Major: 1, Minor: 7, FileMode: 0666, Uid: 0, Gid: 0, }, { Type: 'c', Path: "/dev/tty", Major: 5, Minor: 0, FileMode: 0666, Uid: 0, Gid: 0, }, { Type: 'c', Path: "/dev/zero", Major: 1, Minor: 5, FileMode: 0666, Uid: 0, Gid: 0, }, { Type: 'c', Path: "/dev/urandom", Major: 1, Minor: 9, FileMode: 0666, Uid: 0, Gid: 0, }, } // merge in additional devices from the spec for _, d := range spec.Linux.Devices { var uid, gid uint32 var filemode os.FileMode = 0666 if d.UID != nil { uid = *d.UID } if d.GID != nil { gid = *d.GID } dt, err := stringToDeviceRune(d.Type) if err != nil { return err } if d.FileMode != nil { filemode = *d.FileMode } device := &configs.Device{ Type: dt, Path: d.Path, Major: d.Major, Minor: d.Minor, FileMode: filemode, Uid: uid, Gid: gid, } config.Devices = append(config.Devices, device) } return nil } func setupUserNamespace(spec *specs.Spec, config *configs.Config) error { if len(spec.Linux.UIDMappings) == 0 { return nil } create := func(m specs.LinuxIDMapping) configs.IDMap { return configs.IDMap{ HostID: int(m.HostID), ContainerID: int(m.ContainerID), Size: int(m.Size), } } for _, m := range spec.Linux.UIDMappings { config.UidMappings = append(config.UidMappings, create(m)) } for _, m := range spec.Linux.GIDMappings { config.GidMappings = append(config.GidMappings, create(m)) } rootUID, err := config.HostRootUID() if err != nil { return err } rootGID, err := config.HostRootGID() if err != nil { return err } for _, node := range config.Devices { node.Uid = uint32(rootUID) node.Gid = uint32(rootGID) } return nil } // parseMountOptions parses the string and returns the flags, propagation // flags and any mount data that it contains. func parseMountOptions(options []string) (int, []int, string, int) { var ( flag int pgflag []int data []string extFlags int ) flags := map[string]struct { clear bool flag int }{ "acl": {false, unix.MS_POSIXACL}, "async": {true, unix.MS_SYNCHRONOUS}, "atime": {true, unix.MS_NOATIME}, "bind": {false, unix.MS_BIND}, "defaults": {false, 0}, "dev": {true, unix.MS_NODEV}, "diratime": {true, unix.MS_NODIRATIME}, "dirsync": {false, unix.MS_DIRSYNC}, "exec": {true, unix.MS_NOEXEC}, "iversion": {false, unix.MS_I_VERSION}, "lazytime": {false, unix.MS_LAZYTIME}, "loud": {true, unix.MS_SILENT}, "mand": {false, unix.MS_MANDLOCK}, "noacl": {true, unix.MS_POSIXACL}, "noatime": {false, unix.MS_NOATIME}, "nodev": {false, unix.MS_NODEV}, "nodiratime": {false, unix.MS_NODIRATIME}, "noexec": {false, unix.MS_NOEXEC}, "noiversion": {true, unix.MS_I_VERSION}, "nolazytime": {true, unix.MS_LAZYTIME}, "nomand": {true, unix.MS_MANDLOCK}, "norelatime": {true, unix.MS_RELATIME}, "nostrictatime": {true, unix.MS_STRICTATIME}, "nosuid": {false, unix.MS_NOSUID}, "rbind": {false, unix.MS_BIND | unix.MS_REC}, "relatime": {false, unix.MS_RELATIME}, "remount": {false, unix.MS_REMOUNT}, "ro": {false, unix.MS_RDONLY}, "rw": {true, unix.MS_RDONLY}, "silent": {false, unix.MS_SILENT}, "strictatime": {false, unix.MS_STRICTATIME}, "suid": {true, unix.MS_NOSUID}, "sync": {false, unix.MS_SYNCHRONOUS}, } propagationFlags := map[string]int{ "private": unix.MS_PRIVATE, "shared": unix.MS_SHARED, "slave": unix.MS_SLAVE, "unbindable": unix.MS_UNBINDABLE, "rprivate": unix.MS_PRIVATE | unix.MS_REC, "rshared": unix.MS_SHARED | unix.MS_REC, "rslave": unix.MS_SLAVE | unix.MS_REC, "runbindable": unix.MS_UNBINDABLE | unix.MS_REC, } extensionFlags := map[string]struct { clear bool flag int }{ "tmpcopyup": {false, configs.EXT_COPYUP}, } for _, o := range options { // If the option does not exist in the flags table or the flag // is not supported on the platform, // then it is a data value for a specific fs type if f, exists := flags[o]; exists && f.flag != 0 { if f.clear { flag &= ^f.flag } else { flag |= f.flag } } else if f, exists := propagationFlags[o]; exists && f != 0 { pgflag = append(pgflag, f) } else if f, exists := extensionFlags[o]; exists && f.flag != 0 { if f.clear { extFlags &= ^f.flag } else { extFlags |= f.flag } } else { data = append(data, o) } } return flag, pgflag, strings.Join(data, ","), extFlags } func setupSeccomp(config *specs.LinuxSeccomp) (*configs.Seccomp, error) { if config == nil { return nil, nil } // No default action specified, no syscalls listed, assume seccomp disabled if config.DefaultAction == "" && len(config.Syscalls) == 0 { return nil, nil } newConfig := new(configs.Seccomp) newConfig.Syscalls = []*configs.Syscall{} if len(config.Architectures) > 0 { newConfig.Architectures = []string{} for _, arch := range config.Architectures { newArch, err := seccomp.ConvertStringToArch(string(arch)) if err != nil { return nil, err } newConfig.Architectures = append(newConfig.Architectures, newArch) } } // Convert default action from string representation newDefaultAction, err := seccomp.ConvertStringToAction(string(config.DefaultAction)) if err != nil { return nil, err } newConfig.DefaultAction = newDefaultAction // Loop through all syscall blocks and convert them to libcontainer format for _, call := range config.Syscalls { newAction, err := seccomp.ConvertStringToAction(string(call.Action)) if err != nil { return nil, err } for _, name := range call.Names { newCall := configs.Syscall{ Name: name, Action: newAction, Args: []*configs.Arg{}, } // Loop through all the arguments of the syscall and convert them for _, arg := range call.Args { newOp, err := seccomp.ConvertStringToOperator(string(arg.Op)) if err != nil { return nil, err } newArg := configs.Arg{ Index: arg.Index, Value: arg.Value, ValueTwo: arg.ValueTwo, Op: newOp, } newCall.Args = append(newCall.Args, &newArg) } newConfig.Syscalls = append(newConfig.Syscalls, &newCall) } } return newConfig, nil } func createHooks(rspec *specs.Spec, config *configs.Config) { config.Hooks = &configs.Hooks{} if rspec.Hooks != nil { for _, h := range rspec.Hooks.Prestart { cmd := createCommandHook(h) config.Hooks.Prestart = append(config.Hooks.Prestart, configs.NewCommandHook(cmd)) } for _, h := range rspec.Hooks.Poststart { cmd := createCommandHook(h) config.Hooks.Poststart = append(config.Hooks.Poststart, configs.NewCommandHook(cmd)) } for _, h := range rspec.Hooks.Poststop { cmd := createCommandHook(h) config.Hooks.Poststop = append(config.Hooks.Poststop, configs.NewCommandHook(cmd)) } } } func createCommandHook(h specs.Hook) configs.Command { cmd := configs.Command{ Path: h.Path, Args: h.Args, Env: h.Env, } if h.Timeout != nil { d := time.Duration(*h.Timeout) * time.Second cmd.Timeout = &d } return cmd }