android/neverallow.go - platform/build/soong - Git at Google

 // Copyright 2017 Google Inc. All rights reserved.
 //
 // 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 android

 import (
 	"path/filepath"
 	"reflect"
 	"strconv"
 	"strings"

 	"github.com/google/blueprint/proptools"
 )

 // "neverallow" rules for the build system.
 //
 // This allows things which aren't related to the build system and are enforced
 // for sanity, in progress code refactors, or policy to be expressed in a
 // straightforward away disjoint from implementations and tests which should
 // work regardless of these restrictions.
 //
 // A module is disallowed if all of the following are true:
 // - it is in one of the "in" paths
 // - it is not in one of the "notIn" paths
 // - it has all "with" properties matched
 // - - values are matched in their entirety
 // - - nil is interpreted as an empty string
 // - - nested properties are separated with a '.'
 // - - if the property is a list, any of the values in the list being matches
 //     counts as a match
 // - it has none of the "without" properties matched (same rules as above)

 func registerNeverallowMutator(ctx RegisterMutatorsContext) {
 	ctx.BottomUp("neverallow", neverallowMutator).Parallel()
 }

 var neverallows = []*rule{
 	neverallow().
 		in("vendor", "device").
 		with("vndk.enabled", "true").
 		without("vendor", "true").
 		because("the VNDK can never contain a library that is device dependent."),
 	neverallow().
 		with("vndk.enabled", "true").
 		without("vendor", "true").
 		without("owner", "").
 		because("a VNDK module can never have an owner."),
 	neverallow().notIn("libcore", "development").with("no_standard_libs", "true"),

 	// TODO(b/67974785): always enforce the manifest
 	neverallow().
 		without("name", "libhidltransport").
 		with("product_variables.enforce_vintf_manifest.cflags", "*").
 		because("manifest enforcement should be independent of ."),

 	// TODO(b/67975799): vendor code should always use /vendor/bin/sh
 	neverallow().
 		without("name", "libc_bionic_ndk").
 		with("product_variables.treble_linker_namespaces.cflags", "*").
 		because("nothing should care if linker namespaces are enabled or not"),

 	// Example:
 	// *neverallow().with("Srcs", "main.cpp"),
 }

 func neverallowMutator(ctx BottomUpMutatorContext) {
 	m, ok := ctx.Module().(Module)
 	if !ok {
 		return
 	}

 	dir := ctx.ModuleDir() + "/"
 	properties := m.GetProperties()

 	for _, n := range neverallows {
 		if !n.appliesToPath(dir) {
 			continue
 		}

 		if !n.appliesToProperties(properties) {
 			continue
 		}

 		ctx.ModuleErrorf("violates " + n.String())
 	}
 }

 type ruleProperty struct {
 	fields []string // e.x.: Vndk.Enabled
 	value  string   // e.x.: true
 }

 type rule struct {
 	// User string for why this is a thing.
 	reason string

 	paths       []string
 	unlessPaths []string

 	props       []ruleProperty
 	unlessProps []ruleProperty
 }

 func neverallow() *rule {
 	return &rule{}
 }
 func (r *rule) in(path ...string) *rule {
 	r.paths = append(r.paths, cleanPaths(path)...)
 	return r
 }
 func (r *rule) notIn(path ...string) *rule {
 	r.unlessPaths = append(r.unlessPaths, cleanPaths(path)...)
 	return r
 }
 func (r *rule) with(properties, value string) *rule {
 	r.props = append(r.props, ruleProperty{
 		fields: fieldNamesForProperties(properties),
 		value:  value,
 	})
 	return r
 }
 func (r *rule) without(properties, value string) *rule {
 	r.unlessProps = append(r.unlessProps, ruleProperty{
 		fields: fieldNamesForProperties(properties),
 		value:  value,
 	})
 	return r
 }
 func (r *rule) because(reason string) *rule {
 	r.reason = reason
 	return r
 }

 func (r *rule) String() string {
 	s := "neverallow"
 	for _, v := range r.paths {
 		s += " dir:" + v + "*"
 	}
 	for _, v := range r.unlessPaths {
 		s += " -dir:" + v + "*"
 	}
 	for _, v := range r.props {
 		s += " " + strings.Join(v.fields, ".") + "=" + v.value
 	}
 	for _, v := range r.unlessProps {
 		s += " -" + strings.Join(v.fields, ".") + "=" + v.value
 	}
 	if len(r.reason) != 0 {
 		s += " which is restricted because " + r.reason
 	}
 	return s
 }

 func (r *rule) appliesToPath(dir string) bool {
 	includePath := len(r.paths) == 0 || hasAnyPrefix(dir, r.paths)
 	excludePath := hasAnyPrefix(dir, r.unlessPaths)
 	return includePath && !excludePath
 }

 func (r *rule) appliesToProperties(properties []interface{}) bool {
 	includeProps := hasAllProperties(properties, r.props)
 	excludeProps := hasAnyProperty(properties, r.unlessProps)
 	return includeProps && !excludeProps
 }

 // assorted utils

 func cleanPaths(paths []string) []string {
 	res := make([]string, len(paths))
 	for i, v := range paths {
 		res[i] = filepath.Clean(v) + "/"
 	}
 	return res
 }

 func fieldNamesForProperties(propertyNames string) []string {
 	names := strings.Split(propertyNames, ".")
 	for i, v := range names {
 		names[i] = proptools.FieldNameForProperty(v)
 	}
 	return names
 }

 func hasAnyPrefix(s string, prefixes []string) bool {
 	for _, prefix := range prefixes {
 		if strings.HasPrefix(s, prefix) {
 			return true
 		}
 	}
 	return false
 }

 func hasAnyProperty(properties []interface{}, props []ruleProperty) bool {
 	for _, v := range props {
 		if hasProperty(properties, v) {
 			return true
 		}
 	}
 	return false
 }

 func hasAllProperties(properties []interface{}, props []ruleProperty) bool {
 	for _, v := range props {
 		if !hasProperty(properties, v) {
 			return false
 		}
 	}
 	return true
 }

 func hasProperty(properties []interface{}, prop ruleProperty) bool {
 	for _, propertyStruct := range properties {
 		propertiesValue := reflect.ValueOf(propertyStruct).Elem()
 		for _, v := range prop.fields {
 			if !propertiesValue.IsValid() {
 				break
 			}
 			propertiesValue = propertiesValue.FieldByName(v)
 		}
 		if !propertiesValue.IsValid() {
 			continue
 		}

 		check := func(v string) bool {
 			return prop.value == "*" || prop.value == v
 		}

 		if matchValue(propertiesValue, check) {
 			return true
 		}
 	}
 	return false
 }

 func matchValue(value reflect.Value, check func(string) bool) bool {
 	if !value.IsValid() {
 		return false
 	}

 	if value.Kind() == reflect.Ptr {
 		if value.IsNil() {
 			return check("")
 		}
 		value = value.Elem()
 	}

 	switch value.Kind() {
 	case reflect.String:
 		return check(value.String())
 	case reflect.Bool:
 		return check(strconv.FormatBool(value.Bool()))
 	case reflect.Int:
 		return check(strconv.FormatInt(value.Int(), 10))
 	case reflect.Slice:
 		slice, ok := value.Interface().([]string)
 		if !ok {
 			panic("Can only handle slice of string")
 		}
 		for _, v := range slice {
 			if check(v) {
 				return true
 			}
 		}
 		return false
 	}

 	panic("Can't handle type: " + value.Kind().String())
 }
	// Copyright 2017 Google Inc. All rights reserved.
	//
	// 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 android

	import (
	"path/filepath"
	"reflect"
	"strconv"
	"strings"

	"github.com/google/blueprint/proptools"
	)

	// "neverallow" rules for the build system.
	//
	// This allows things which aren't related to the build system and are enforced
	// for sanity, in progress code refactors, or policy to be expressed in a
	// straightforward away disjoint from implementations and tests which should
	// work regardless of these restrictions.
	//
	// A module is disallowed if all of the following are true:
	// - it is in one of the "in" paths
	// - it is not in one of the "notIn" paths
	// - it has all "with" properties matched
	// - - values are matched in their entirety
	// - - nil is interpreted as an empty string
	// - - nested properties are separated with a '.'
	// - - if the property is a list, any of the values in the list being matches
	// counts as a match
	// - it has none of the "without" properties matched (same rules as above)

	func registerNeverallowMutator(ctx RegisterMutatorsContext) {
	ctx.BottomUp("neverallow", neverallowMutator).Parallel()
	}

	var neverallows = []*rule{
	neverallow().
	in("vendor", "device").
	with("vndk.enabled", "true").
	without("vendor", "true").
	because("the VNDK can never contain a library that is device dependent."),
	neverallow().
	with("vndk.enabled", "true").
	without("vendor", "true").
	without("owner", "").
	because("a VNDK module can never have an owner."),
	neverallow().notIn("libcore", "development").with("no_standard_libs", "true"),

	// TODO(b/67974785): always enforce the manifest
	neverallow().
	without("name", "libhidltransport").
	with("product_variables.enforce_vintf_manifest.cflags", "*").
	because("manifest enforcement should be independent of ."),

	// TODO(b/67975799): vendor code should always use /vendor/bin/sh
	neverallow().
	without("name", "libc_bionic_ndk").
	with("product_variables.treble_linker_namespaces.cflags", "*").
	because("nothing should care if linker namespaces are enabled or not"),

	// Example:
	// *neverallow().with("Srcs", "main.cpp"),
	}

	func neverallowMutator(ctx BottomUpMutatorContext) {
	m, ok := ctx.Module().(Module)
	if !ok {
	return
	}

	dir := ctx.ModuleDir() + "/"
	properties := m.GetProperties()

	for _, n := range neverallows {
	if !n.appliesToPath(dir) {
	continue
	}

	if !n.appliesToProperties(properties) {
	continue
	}

	ctx.ModuleErrorf("violates " + n.String())
	}
	}

	type ruleProperty struct {
	fields []string // e.x.: Vndk.Enabled
	value string // e.x.: true
	}

	type rule struct {
	// User string for why this is a thing.
	reason string

	paths []string
	unlessPaths []string

	props []ruleProperty
	unlessProps []ruleProperty
	}

	func neverallow() *rule {
	return &rule{}
	}
	func (r rule) in(path ...string) rule {
	r.paths = append(r.paths, cleanPaths(path)...)
	return r
	}
	func (r rule) notIn(path ...string) rule {
	r.unlessPaths = append(r.unlessPaths, cleanPaths(path)...)
	return r
	}
	func (r rule) with(properties, value string) rule {
	r.props = append(r.props, ruleProperty{
	fields: fieldNamesForProperties(properties),
	value: value,
	})
	return r
	}
	func (r rule) without(properties, value string) rule {
	r.unlessProps = append(r.unlessProps, ruleProperty{
	fields: fieldNamesForProperties(properties),
	value: value,
	})
	return r
	}
	func (r rule) because(reason string) rule {
	r.reason = reason
	return r
	}

	func (r *rule) String() string {
	s := "neverallow"
	for _, v := range r.paths {
	s += " dir:" + v + "*"
	}
	for _, v := range r.unlessPaths {
	s += " -dir:" + v + "*"
	}
	for _, v := range r.props {
	s += " " + strings.Join(v.fields, ".") + "=" + v.value
	}
	for _, v := range r.unlessProps {
	s += " -" + strings.Join(v.fields, ".") + "=" + v.value
	}
	if len(r.reason) != 0 {
	s += " which is restricted because " + r.reason
	}
	return s
	}

	func (r *rule) appliesToPath(dir string) bool {
	includePath := len(r.paths) == 0 \|\| hasAnyPrefix(dir, r.paths)
	excludePath := hasAnyPrefix(dir, r.unlessPaths)
	return includePath && !excludePath
	}

	func (r *rule) appliesToProperties(properties []interface{}) bool {
	includeProps := hasAllProperties(properties, r.props)
	excludeProps := hasAnyProperty(properties, r.unlessProps)
	return includeProps && !excludeProps
	}

	// assorted utils

	func cleanPaths(paths []string) []string {
	res := make([]string, len(paths))
	for i, v := range paths {
	res[i] = filepath.Clean(v) + "/"
	}
	return res
	}

	func fieldNamesForProperties(propertyNames string) []string {
	names := strings.Split(propertyNames, ".")
	for i, v := range names {
	names[i] = proptools.FieldNameForProperty(v)
	}
	return names
	}

	func hasAnyPrefix(s string, prefixes []string) bool {
	for _, prefix := range prefixes {
	if strings.HasPrefix(s, prefix) {
	return true
	}
	}
	return false
	}

	func hasAnyProperty(properties []interface{}, props []ruleProperty) bool {
	for _, v := range props {
	if hasProperty(properties, v) {
	return true
	}
	}
	return false
	}

	func hasAllProperties(properties []interface{}, props []ruleProperty) bool {
	for _, v := range props {
	if !hasProperty(properties, v) {
	return false
	}
	}
	return true
	}

	func hasProperty(properties []interface{}, prop ruleProperty) bool {
	for _, propertyStruct := range properties {
	propertiesValue := reflect.ValueOf(propertyStruct).Elem()
	for _, v := range prop.fields {
	if !propertiesValue.IsValid() {
	break
	}
	propertiesValue = propertiesValue.FieldByName(v)
	}
	if !propertiesValue.IsValid() {
	continue
	}

	check := func(v string) bool {
	return prop.value == "*" \|\| prop.value == v
	}

	if matchValue(propertiesValue, check) {
	return true
	}
	}
	return false
	}

	func matchValue(value reflect.Value, check func(string) bool) bool {
	if !value.IsValid() {
	return false
	}

	if value.Kind() == reflect.Ptr {
	if value.IsNil() {
	return check("")
	}
	value = value.Elem()
	}

	switch value.Kind() {
	case reflect.String:
	return check(value.String())
	case reflect.Bool:
	return check(strconv.FormatBool(value.Bool()))
	case reflect.Int:
	return check(strconv.FormatInt(value.Int(), 10))
	case reflect.Slice:
	slice, ok := value.Interface().([]string)
	if !ok {
	panic("Can only handle slice of string")
	}
	for _, v := range slice {
	if check(v) {
	return true
	}
	}
	return false
	}

	panic("Can't handle type: " + value.Kind().String())
	}