1// Copyright (C) 2022 The Android Open Source Project
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15package filesystem
16
17import (
18	"fmt"
19	"strconv"
20
21	"github.com/google/blueprint/proptools"
22
23	"android/soong/android"
24)
25
26type avbAddHashFooter struct {
27	android.ModuleBase
28	android.DefaultableModuleBase
29
30	properties avbAddHashFooterProperties
31
32	output     android.OutputPath
33	installDir android.InstallPath
34}
35
36type avbProp struct {
37	// Name of a property
38	Name *string
39
40	// Value of a property. Can't be used together with `file`.
41	Value *string
42
43	// File from which the value of the prop is read from. Can't be used together with `value`.
44	File *string `android:"path,arch_variant"`
45}
46
47type avbAddHashFooterProperties struct {
48	// Source file of this image. Can reference a genrule type module with the ":module" syntax.
49	Src *string `android:"path,arch_variant"`
50
51	// Set the name of the output. Defaults to <module_name>.img.
52	Filename *string
53
54	// Name of the image partition. Defaults to the name of this module.
55	Partition_name *string
56
57	// Size of the partition. Defaults to dynamically calculating the size.
58	Partition_size *int64
59
60	// Path to the private key that avbtool will use to sign this image.
61	Private_key *string `android:"path"`
62
63	// Algorithm that avbtool will use to sign this image. Default is SHA256_RSA4096.
64	Algorithm *string
65
66	// The salt in hex. Required for reproducible builds.
67	Salt *string
68
69	// List of properties to add to the footer
70	Props []avbProp
71
72	// The index used to prevent rollback of the image on device.
73	Rollback_index *int64
74
75	// Include descriptors from images
76	Include_descriptors_from_images []string `android:"path,arch_variant"`
77}
78
79// The AVB footer adds verification information to the image.
80func avbAddHashFooterFactory() android.Module {
81	module := &avbAddHashFooter{}
82	module.AddProperties(&module.properties)
83	android.InitAndroidArchModule(module, android.DeviceSupported, android.MultilibFirst)
84	android.InitDefaultableModule(module)
85	return module
86}
87
88func (a *avbAddHashFooter) installFileName() string {
89	return proptools.StringDefault(a.properties.Filename, a.BaseModuleName()+".img")
90}
91
92func (a *avbAddHashFooter) GenerateAndroidBuildActions(ctx android.ModuleContext) {
93	builder := android.NewRuleBuilder(pctx, ctx)
94
95	if a.properties.Src == nil {
96		ctx.PropertyErrorf("src", "missing source file")
97		return
98	}
99	input := android.PathForModuleSrc(ctx, proptools.String(a.properties.Src))
100	a.output = android.PathForModuleOut(ctx, a.installFileName()).OutputPath
101	builder.Command().Text("cp").Input(input).Output(a.output)
102
103	cmd := builder.Command().BuiltTool("avbtool").Text("add_hash_footer")
104
105	partition_name := proptools.StringDefault(a.properties.Partition_name, a.BaseModuleName())
106	cmd.FlagWithArg("--partition_name ", partition_name)
107
108	if a.properties.Partition_size == nil {
109		cmd.Flag("--dynamic_partition_size")
110	} else {
111		partition_size := proptools.Int(a.properties.Partition_size)
112		cmd.FlagWithArg("--partition_size ", strconv.Itoa(partition_size))
113	}
114
115	key := android.PathForModuleSrc(ctx, proptools.String(a.properties.Private_key))
116	cmd.FlagWithInput("--key ", key)
117
118	algorithm := proptools.StringDefault(a.properties.Algorithm, "SHA256_RSA4096")
119	cmd.FlagWithArg("--algorithm ", algorithm)
120
121	if a.properties.Salt == nil {
122		ctx.PropertyErrorf("salt", "missing salt value")
123		return
124	}
125	cmd.FlagWithArg("--salt ", proptools.String(a.properties.Salt))
126
127	imagePaths := android.PathsForModuleSrc(ctx, a.properties.Include_descriptors_from_images)
128	for _, imagePath := range imagePaths {
129		cmd.FlagWithInput("--include_descriptors_from_image ", imagePath)
130	}
131
132	for _, prop := range a.properties.Props {
133		addAvbProp(ctx, cmd, prop)
134	}
135
136	if a.properties.Rollback_index != nil {
137		rollbackIndex := proptools.Int(a.properties.Rollback_index)
138		if rollbackIndex < 0 {
139			ctx.PropertyErrorf("rollback_index", "Rollback index must be non-negative")
140		}
141		cmd.Flag(fmt.Sprintf(" --rollback_index %d", rollbackIndex))
142	}
143
144	cmd.FlagWithOutput("--image ", a.output)
145
146	builder.Build("avbAddHashFooter", fmt.Sprintf("avbAddHashFooter %s", ctx.ModuleName()))
147
148	a.installDir = android.PathForModuleInstall(ctx, "etc")
149	ctx.InstallFile(a.installDir, a.installFileName(), a.output)
150}
151
152func addAvbProp(ctx android.ModuleContext, cmd *android.RuleBuilderCommand, prop avbProp) {
153	name := proptools.String(prop.Name)
154	value := proptools.String(prop.Value)
155	file := proptools.String(prop.File)
156	if name == "" {
157		ctx.PropertyErrorf("name", "can't be empty")
158		return
159	}
160	if value == "" && file == "" {
161		ctx.PropertyErrorf("value", "either value or file should be set")
162		return
163	}
164	if value != "" && file != "" {
165		ctx.PropertyErrorf("value", "value and file can't be set at the same time")
166		return
167	}
168
169	if value != "" {
170		cmd.FlagWithArg("--prop ", proptools.ShellEscape(fmt.Sprintf("%s:%s", name, value)))
171	} else {
172		p := android.PathForModuleSrc(ctx, file)
173		cmd.Implicit(p)
174		cmd.FlagWithArg("--prop_from_file ", proptools.ShellEscape(fmt.Sprintf("%s:%s", name, cmd.PathForInput(p))))
175	}
176}
177
178var _ android.AndroidMkEntriesProvider = (*avbAddHashFooter)(nil)
179
180// Implements android.AndroidMkEntriesProvider
181func (a *avbAddHashFooter) AndroidMkEntries() []android.AndroidMkEntries {
182	return []android.AndroidMkEntries{android.AndroidMkEntries{
183		Class:      "ETC",
184		OutputFile: android.OptionalPathForPath(a.output),
185		ExtraEntries: []android.AndroidMkExtraEntriesFunc{
186			func(ctx android.AndroidMkExtraEntriesContext, entries *android.AndroidMkEntries) {
187				entries.SetString("LOCAL_MODULE_PATH", a.installDir.String())
188				entries.SetString("LOCAL_INSTALLED_MODULE_STEM", a.installFileName())
189			},
190		},
191	}}
192}
193
194var _ Filesystem = (*avbAddHashFooter)(nil)
195
196func (a *avbAddHashFooter) OutputPath() android.Path {
197	return a.output
198}
199
200func (a *avbAddHashFooter) SignedOutputPath() android.Path {
201	return a.OutputPath() // always signed
202}
203
204// TODO(b/185115783): remove when not needed as input to a prebuilt_etc rule
205var _ android.SourceFileProducer = (*avbAddHashFooter)(nil)
206
207// Implements android.SourceFileProducer
208func (a *avbAddHashFooter) Srcs() android.Paths {
209	return append(android.Paths{}, a.output)
210}
211
212type avbAddHashFooterDefaults struct {
213	android.ModuleBase
214	android.DefaultsModuleBase
215}
216
217// avb_add_hash_footer_defaults provides a set of properties that can be inherited by other
218// avb_add_hash_footer modules. A module can use the properties from an avb_add_hash_footer_defaults
219// using `defaults: ["<:default_module_name>"]`. Properties of both modules are erged (when
220// possible) by prepending the default module's values to the depending module's values.
221func avbAddHashFooterDefaultsFactory() android.Module {
222	module := &avbAddHashFooterDefaults{}
223	module.AddProperties(&avbAddHashFooterProperties{})
224	android.InitDefaultsModule(module)
225	return module
226}
227