diff options
author | Brent Baude <bbaude@redhat.com> | 2020-04-16 08:39:34 -0500 |
---|---|---|
committer | Brent Baude <bbaude@redhat.com> | 2020-04-16 12:04:46 -0500 |
commit | ba430bfe5ef65d5aa5ffa1fef0087da76aafcc35 (patch) | |
tree | 3554a8bc2a5add5feee1d008d594665f82279fb3 /pkg/specgen/generate/config_linux.go | |
parent | 8857ba20a0651e8fa71762da90d774e3aa290883 (diff) | |
download | podman-ba430bfe5ef65d5aa5ffa1fef0087da76aafcc35.tar.gz podman-ba430bfe5ef65d5aa5ffa1fef0087da76aafcc35.tar.bz2 podman-ba430bfe5ef65d5aa5ffa1fef0087da76aafcc35.zip |
podman v2 remove bloat v2
rid ourseleves of libpod references in v2 client
Signed-off-by: Brent Baude <bbaude@redhat.com>
Diffstat (limited to 'pkg/specgen/generate/config_linux.go')
-rw-r--r-- | pkg/specgen/generate/config_linux.go | 323 |
1 files changed, 323 insertions, 0 deletions
diff --git a/pkg/specgen/generate/config_linux.go b/pkg/specgen/generate/config_linux.go new file mode 100644 index 000000000..1b2a2ac32 --- /dev/null +++ b/pkg/specgen/generate/config_linux.go @@ -0,0 +1,323 @@ +package generate + +import ( + "fmt" + "io/ioutil" + "os" + "path/filepath" + "strings" + + "github.com/containers/libpod/pkg/rootless" + "github.com/opencontainers/runc/libcontainer/configs" + "github.com/opencontainers/runc/libcontainer/devices" + spec "github.com/opencontainers/runtime-spec/specs-go" + "github.com/opencontainers/runtime-tools/generate" + "github.com/pkg/errors" + "golang.org/x/sys/unix" +) + +func u32Ptr(i int64) *uint32 { u := uint32(i); return &u } +func fmPtr(i int64) *os.FileMode { fm := os.FileMode(i); return &fm } + +// Device transforms a libcontainer configs.Device to a specs.LinuxDevice object. +func Device(d *configs.Device) spec.LinuxDevice { + return spec.LinuxDevice{ + Type: string(d.Type), + Path: d.Path, + Major: d.Major, + Minor: d.Minor, + FileMode: fmPtr(int64(d.FileMode)), + UID: u32Ptr(int64(d.Uid)), + GID: u32Ptr(int64(d.Gid)), + } +} + +func addPrivilegedDevices(g *generate.Generator) error { + hostDevices, err := getDevices("/dev") + if err != nil { + return err + } + g.ClearLinuxDevices() + + if rootless.IsRootless() { + mounts := make(map[string]interface{}) + for _, m := range g.Mounts() { + mounts[m.Destination] = true + } + newMounts := []spec.Mount{} + for _, d := range hostDevices { + devMnt := spec.Mount{ + Destination: d.Path, + Type: TypeBind, + Source: d.Path, + Options: []string{"slave", "nosuid", "noexec", "rw", "rbind"}, + } + if d.Path == "/dev/ptmx" || strings.HasPrefix(d.Path, "/dev/tty") { + continue + } + if _, found := mounts[d.Path]; found { + continue + } + st, err := os.Stat(d.Path) + if err != nil { + if err == unix.EPERM { + continue + } + return errors.Wrapf(err, "stat %s", d.Path) + } + // Skip devices that the user has not access to. + if st.Mode()&0007 == 0 { + continue + } + newMounts = append(newMounts, devMnt) + } + g.Config.Mounts = append(newMounts, g.Config.Mounts...) + g.Config.Linux.Resources.Devices = nil + } else { + for _, d := range hostDevices { + g.AddDevice(Device(d)) + } + // Add resources device - need to clear the existing one first. + g.Config.Linux.Resources.Devices = nil + g.AddLinuxResourcesDevice(true, "", nil, nil, "rwm") + } + + return nil +} + +// DevicesFromPath computes a list of devices +func DevicesFromPath(g *generate.Generator, devicePath string) error { + devs := strings.Split(devicePath, ":") + resolvedDevicePath := devs[0] + // check if it is a symbolic link + if src, err := os.Lstat(resolvedDevicePath); err == nil && src.Mode()&os.ModeSymlink == os.ModeSymlink { + if linkedPathOnHost, err := filepath.EvalSymlinks(resolvedDevicePath); err == nil { + resolvedDevicePath = linkedPathOnHost + } + } + st, err := os.Stat(resolvedDevicePath) + if err != nil { + return errors.Wrapf(err, "cannot stat %s", devicePath) + } + if st.IsDir() { + found := false + src := resolvedDevicePath + dest := src + var devmode string + if len(devs) > 1 { + if len(devs[1]) > 0 && devs[1][0] == '/' { + dest = devs[1] + } else { + devmode = devs[1] + } + } + if len(devs) > 2 { + if devmode != "" { + return errors.Wrapf(unix.EINVAL, "invalid device specification %s", devicePath) + } + devmode = devs[2] + } + + // mount the internal devices recursively + if err := filepath.Walk(resolvedDevicePath, func(dpath string, f os.FileInfo, e error) error { + + if f.Mode()&os.ModeDevice == os.ModeDevice { + found = true + device := fmt.Sprintf("%s:%s", dpath, filepath.Join(dest, strings.TrimPrefix(dpath, src))) + if devmode != "" { + device = fmt.Sprintf("%s:%s", device, devmode) + } + if err := addDevice(g, device); err != nil { + return errors.Wrapf(err, "failed to add %s device", dpath) + } + } + return nil + }); err != nil { + return err + } + if !found { + return errors.Wrapf(unix.EINVAL, "no devices found in %s", devicePath) + } + return nil + } + + return addDevice(g, strings.Join(append([]string{resolvedDevicePath}, devs[1:]...), ":")) +} + +func BlockAccessToKernelFilesystems(privileged, pidModeIsHost bool, g *generate.Generator) { + if !privileged { + for _, mp := range []string{ + "/proc/acpi", + "/proc/kcore", + "/proc/keys", + "/proc/latency_stats", + "/proc/timer_list", + "/proc/timer_stats", + "/proc/sched_debug", + "/proc/scsi", + "/sys/firmware", + "/sys/fs/selinux", + } { + g.AddLinuxMaskedPaths(mp) + } + + if pidModeIsHost && rootless.IsRootless() { + return + } + + for _, rp := range []string{ + "/proc/asound", + "/proc/bus", + "/proc/fs", + "/proc/irq", + "/proc/sys", + "/proc/sysrq-trigger", + } { + g.AddLinuxReadonlyPaths(rp) + } + } +} + +// based on getDevices from runc (libcontainer/devices/devices.go) +func getDevices(path string) ([]*configs.Device, error) { + files, err := ioutil.ReadDir(path) + if err != nil { + if rootless.IsRootless() && os.IsPermission(err) { + return nil, nil + } + return nil, err + } + out := []*configs.Device{} + for _, f := range files { + switch { + case f.IsDir(): + switch f.Name() { + // ".lxc" & ".lxd-mounts" added to address https://github.com/lxc/lxd/issues/2825 + case "pts", "shm", "fd", "mqueue", ".lxc", ".lxd-mounts": + continue + default: + sub, err := getDevices(filepath.Join(path, f.Name())) + if err != nil { + return nil, err + } + if sub != nil { + out = append(out, sub...) + } + continue + } + case f.Name() == "console": + continue + } + device, err := devices.DeviceFromPath(filepath.Join(path, f.Name()), "rwm") + if err != nil { + if err == devices.ErrNotADevice { + continue + } + if os.IsNotExist(err) { + continue + } + return nil, err + } + out = append(out, device) + } + return out, nil +} + +func addDevice(g *generate.Generator, device string) error { + src, dst, permissions, err := ParseDevice(device) + if err != nil { + return err + } + dev, err := devices.DeviceFromPath(src, permissions) + if err != nil { + return errors.Wrapf(err, "%s is not a valid device", src) + } + if rootless.IsRootless() { + if _, err := os.Stat(src); err != nil { + if os.IsNotExist(err) { + return errors.Wrapf(err, "the specified device %s doesn't exist", src) + } + return errors.Wrapf(err, "stat device %s exist", src) + } + perm := "ro" + if strings.Contains(permissions, "w") { + perm = "rw" + } + devMnt := spec.Mount{ + Destination: dst, + Type: TypeBind, + Source: src, + Options: []string{"slave", "nosuid", "noexec", perm, "rbind"}, + } + g.Config.Mounts = append(g.Config.Mounts, devMnt) + return nil + } + dev.Path = dst + linuxdev := spec.LinuxDevice{ + Path: dev.Path, + Type: string(dev.Type), + Major: dev.Major, + Minor: dev.Minor, + FileMode: &dev.FileMode, + UID: &dev.Uid, + GID: &dev.Gid, + } + g.AddDevice(linuxdev) + g.AddLinuxResourcesDevice(true, string(dev.Type), &dev.Major, &dev.Minor, dev.Permissions) + return nil +} + +// ParseDevice parses device mapping string to a src, dest & permissions string +func ParseDevice(device string) (string, string, string, error) { //nolint + src := "" + dst := "" + permissions := "rwm" + arr := strings.Split(device, ":") + switch len(arr) { + case 3: + if !IsValidDeviceMode(arr[2]) { + return "", "", "", fmt.Errorf("invalid device mode: %s", arr[2]) + } + permissions = arr[2] + fallthrough + case 2: + if IsValidDeviceMode(arr[1]) { + permissions = arr[1] + } else { + if arr[1][0] != '/' { + return "", "", "", fmt.Errorf("invalid device mode: %s", arr[1]) + } + dst = arr[1] + } + fallthrough + case 1: + src = arr[0] + default: + return "", "", "", fmt.Errorf("invalid device specification: %s", device) + } + + if dst == "" { + dst = src + } + return src, dst, permissions, nil +} + +// IsValidDeviceMode checks if the mode for device is valid or not. +// IsValid mode is a composition of r (read), w (write), and m (mknod). +func IsValidDeviceMode(mode string) bool { + var legalDeviceMode = map[rune]bool{ + 'r': true, + 'w': true, + 'm': true, + } + if mode == "" { + return false + } + for _, c := range mode { + if !legalDeviceMode[c] { + return false + } + legalDeviceMode[c] = false + } + return true +} |