From a031b83a09a8628435317a03f199cdc18b78262f Mon Sep 17 00:00:00 2001 From: Matthew Heon Date: Wed, 1 Nov 2017 11:24:59 -0400 Subject: Initial checkin from CRI-O repo Signed-off-by: Matthew Heon --- .../kubernetes/pkg/security/apparmor/validate.go | 228 +++++++++++++++++++++ 1 file changed, 228 insertions(+) create mode 100644 vendor/k8s.io/kubernetes/pkg/security/apparmor/validate.go (limited to 'vendor/k8s.io/kubernetes/pkg/security/apparmor/validate.go') diff --git a/vendor/k8s.io/kubernetes/pkg/security/apparmor/validate.go b/vendor/k8s.io/kubernetes/pkg/security/apparmor/validate.go new file mode 100644 index 000000000..cf12df3c1 --- /dev/null +++ b/vendor/k8s.io/kubernetes/pkg/security/apparmor/validate.go @@ -0,0 +1,228 @@ +/* +Copyright 2016 The Kubernetes Authors. + +Licensed under the Apache License, Version 2.0 (the "License"); +you may not use this file except in compliance with the License. +You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + +Unless required by applicable law or agreed to in writing, software +distributed under the License is distributed on an "AS IS" BASIS, +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +See the License for the specific language governing permissions and +limitations under the License. +*/ + +package apparmor + +import ( + "bufio" + "errors" + "fmt" + "io/ioutil" + "os" + "path" + "strings" + + utilfeature "k8s.io/apiserver/pkg/util/feature" + "k8s.io/kubernetes/pkg/api/v1" + "k8s.io/kubernetes/pkg/features" + "k8s.io/kubernetes/pkg/util" +) + +// Whether AppArmor should be disabled by default. +// Set to true if the wrong build tags are set (see validate_disabled.go). +var isDisabledBuild bool + +// Interface for validating that a pod with with an AppArmor profile can be run by a Node. +type Validator interface { + Validate(pod *v1.Pod) error + ValidateHost() error +} + +func NewValidator(runtime string) Validator { + if err := validateHost(runtime); err != nil { + return &validator{validateHostErr: err} + } + appArmorFS, err := getAppArmorFS() + if err != nil { + return &validator{ + validateHostErr: fmt.Errorf("error finding AppArmor FS: %v", err), + } + } + return &validator{ + appArmorFS: appArmorFS, + } +} + +type validator struct { + validateHostErr error + appArmorFS string +} + +func (v *validator) Validate(pod *v1.Pod) error { + if !isRequired(pod) { + return nil + } + + if v.ValidateHost() != nil { + return v.validateHostErr + } + + loadedProfiles, err := v.getLoadedProfiles() + if err != nil { + return fmt.Errorf("could not read loaded profiles: %v", err) + } + + for _, container := range pod.Spec.InitContainers { + if err := validateProfile(GetProfileName(pod, container.Name), loadedProfiles); err != nil { + return err + } + } + for _, container := range pod.Spec.Containers { + if err := validateProfile(GetProfileName(pod, container.Name), loadedProfiles); err != nil { + return err + } + } + + return nil +} + +func (v *validator) ValidateHost() error { + return v.validateHostErr +} + +// Verify that the host and runtime is capable of enforcing AppArmor profiles. +func validateHost(runtime string) error { + // Check feature-gates + if !utilfeature.DefaultFeatureGate.Enabled(features.AppArmor) { + return errors.New("AppArmor disabled by feature-gate") + } + + // Check build support. + if isDisabledBuild { + return errors.New("Binary not compiled for linux") + } + + // Check kernel support. + if !IsAppArmorEnabled() { + return errors.New("AppArmor is not enabled on the host") + } + + // Check runtime support. Currently only Docker is supported. + if runtime != "docker" { + return fmt.Errorf("AppArmor is only enabled for 'docker' runtime. Found: %q.", runtime) + } + + return nil +} + +// Verify that the profile is valid and loaded. +func validateProfile(profile string, loadedProfiles map[string]bool) error { + if err := ValidateProfileFormat(profile); err != nil { + return err + } + + if strings.HasPrefix(profile, ProfileNamePrefix) { + profileName := strings.TrimPrefix(profile, ProfileNamePrefix) + if !loadedProfiles[profileName] { + return fmt.Errorf("profile %q is not loaded", profileName) + } + } + + return nil +} + +func ValidateProfileFormat(profile string) error { + if profile == "" || profile == ProfileRuntimeDefault { + return nil + } + if !strings.HasPrefix(profile, ProfileNamePrefix) { + return fmt.Errorf("invalid AppArmor profile name: %q", profile) + } + return nil +} + +func (v *validator) getLoadedProfiles() (map[string]bool, error) { + profilesPath := path.Join(v.appArmorFS, "profiles") + profilesFile, err := os.Open(profilesPath) + if err != nil { + return nil, fmt.Errorf("failed to open %s: %v", profilesPath, err) + } + defer profilesFile.Close() + + profiles := map[string]bool{} + scanner := bufio.NewScanner(profilesFile) + for scanner.Scan() { + profileName := parseProfileName(scanner.Text()) + if profileName == "" { + // Unknown line format; skip it. + continue + } + profiles[profileName] = true + } + return profiles, nil +} + +// The profiles file is formatted with one profile per line, matching a form: +// namespace://profile-name (mode) +// profile-name (mode) +// Where mode is {enforce, complain, kill}. The "namespace://" is only included for namespaced +// profiles. For the purposes of Kubernetes, we consider the namespace part of the profile name. +func parseProfileName(profileLine string) string { + modeIndex := strings.IndexRune(profileLine, '(') + if modeIndex < 0 { + return "" + } + return strings.TrimSpace(profileLine[:modeIndex]) +} + +func getAppArmorFS() (string, error) { + mountsFile, err := os.Open("/proc/mounts") + if err != nil { + return "", fmt.Errorf("could not open /proc/mounts: %v", err) + } + defer mountsFile.Close() + + scanner := bufio.NewScanner(mountsFile) + for scanner.Scan() { + fields := strings.Fields(scanner.Text()) + if len(fields) < 3 { + // Unknown line format; skip it. + continue + } + if fields[2] == "securityfs" { + appArmorFS := path.Join(fields[1], "apparmor") + if ok, err := util.FileExists(appArmorFS); !ok { + msg := fmt.Sprintf("path %s does not exist", appArmorFS) + if err != nil { + return "", fmt.Errorf("%s: %v", msg, err) + } else { + return "", errors.New(msg) + } + } else { + return appArmorFS, nil + } + } + } + if err := scanner.Err(); err != nil { + return "", fmt.Errorf("error scanning mounts: %v", err) + } + + return "", errors.New("securityfs not found") +} + +// IsAppArmorEnabled returns true if apparmor is enabled for the host. +// This function is forked from +// https://github.com/opencontainers/runc/blob/1a81e9ab1f138c091fe5c86d0883f87716088527/libcontainer/apparmor/apparmor.go +// to avoid the libapparmor dependency. +func IsAppArmorEnabled() bool { + if _, err := os.Stat("/sys/kernel/security/apparmor"); err == nil && os.Getenv("container") == "" { + if _, err = os.Stat("/sbin/apparmor_parser"); err == nil { + buf, err := ioutil.ReadFile("/sys/module/apparmor/parameters/enabled") + return err == nil && len(buf) > 1 && buf[0] == 'Y' + } + } + return false +} -- cgit v1.2.3-54-g00ecf