Merge "aconfig: update aconfig_storage_read_api" into main
diff --git a/tools/aconfig/aconfig_storage_read_api/aconfig_storage_read_api.cpp b/tools/aconfig/aconfig_storage_read_api/aconfig_storage_read_api.cpp
index b5bcf7d..ea756b3 100644
--- a/tools/aconfig/aconfig_storage_read_api/aconfig_storage_read_api.cpp
+++ b/tools/aconfig/aconfig_storage_read_api/aconfig_storage_read_api.cpp
@@ -74,11 +74,6 @@
if (fstat(fd, &fd_stat) < 0) {
return Error() << "fstat failed";
}
-
- if ((fd_stat.st_mode & (S_IWUSR | S_IWGRP | S_IWOTH)) != 0) {
- return Error() << "cannot map writeable file";
- }
-
size_t file_size = fd_stat.st_size;
void* const map_result = mmap(nullptr, file_size, PROT_READ, MAP_SHARED, fd, 0);
diff --git a/tools/aconfig/aconfig_storage_read_api/src/lib.rs b/tools/aconfig/aconfig_storage_read_api/src/lib.rs
index ea45f5d..8a71480 100644
--- a/tools/aconfig/aconfig_storage_read_api/src/lib.rs
+++ b/tools/aconfig/aconfig_storage_read_api/src/lib.rs
@@ -64,11 +64,17 @@
/// \input container: the flag package container
/// \input file_type: stoarge file type enum
/// \return a result of read only mapped file
-pub fn get_mapped_storage_file(
+///
+/// # Safety
+///
+/// The memory mapped file may have undefined behavior if there are writes to this
+/// file after being mapped. Ensure no writes can happen to this file while this
+/// mapping stays alive.
+pub unsafe fn get_mapped_storage_file(
container: &str,
file_type: StorageFileType,
) -> Result<Mmap, AconfigStorageError> {
- crate::mapped_file::get_mapped_file(STORAGE_LOCATION_FILE, container, file_type)
+ unsafe { crate::mapped_file::get_mapped_file(STORAGE_LOCATION_FILE, container, file_type) }
}
/// Get package start offset for flags.
@@ -311,10 +317,10 @@
use aconfig_storage_file::protos::storage_record_pb::write_proto_to_temp_file;
use tempfile::NamedTempFile;
- fn create_test_storage_files(read_only: bool) -> [NamedTempFile; 4] {
- let package_map = copy_to_temp_file("./tests/package.map", read_only).unwrap();
- let flag_map = copy_to_temp_file("./tests/flag.map", read_only).unwrap();
- let flag_val = copy_to_temp_file("./tests/flag.val", read_only).unwrap();
+ fn create_test_storage_files() -> [NamedTempFile; 4] {
+ let package_map = copy_to_temp_file("./tests/package.map").unwrap();
+ let flag_map = copy_to_temp_file("./tests/flag.map").unwrap();
+ let flag_val = copy_to_temp_file("./tests/flag.val").unwrap();
let text_proto = format!(
r#"
@@ -338,10 +344,11 @@
#[test]
// this test point locks down flag package offset query
fn test_package_offset_query() {
- let [package_map, flag_map, flag_val, pb_file] = create_test_storage_files(true);
+ let [_package_map, _flag_map, _flag_val, pb_file] = create_test_storage_files();
let pb_file_path = pb_file.path().display().to_string();
- let package_mapped_file =
- get_mapped_file(&pb_file_path, "system", StorageFileType::PackageMap).unwrap();
+ let package_mapped_file = unsafe {
+ get_mapped_file(&pb_file_path, "system", StorageFileType::PackageMap).unwrap()
+ };
let package_offset =
get_package_offset(&package_mapped_file, "com.android.aconfig.storage.test_1")
@@ -368,10 +375,10 @@
#[test]
// this test point locks down flag offset query
fn test_flag_offset_query() {
- let [package_map, flag_map, flag_val, pb_file] = create_test_storage_files(true);
+ let [_package_map, _flag_map, _flag_val, pb_file] = create_test_storage_files();
let pb_file_path = pb_file.path().display().to_string();
let flag_mapped_file =
- get_mapped_file(&pb_file_path, "system", StorageFileType::FlagMap).unwrap();
+ unsafe { get_mapped_file(&pb_file_path, "system", StorageFileType::FlagMap).unwrap() };
let baseline = vec![
(0, "enabled_ro", 1u16),
@@ -393,10 +400,10 @@
#[test]
// this test point locks down flag offset query
fn test_flag_value_query() {
- let [package_map, flag_map, flag_val, pb_file] = create_test_storage_files(true);
+ let [_package_map, _flag_map, _flag_val, pb_file] = create_test_storage_files();
let pb_file_path = pb_file.path().display().to_string();
let flag_value_file =
- get_mapped_file(&pb_file_path, "system", StorageFileType::FlagVal).unwrap();
+ unsafe { get_mapped_file(&pb_file_path, "system", StorageFileType::FlagVal).unwrap() };
let baseline: Vec<bool> = vec![false; 8];
for (offset, expected_value) in baseline.into_iter().enumerate() {
let flag_value = get_boolean_flag_value(&flag_value_file, offset as u32).unwrap();
@@ -407,7 +414,6 @@
#[test]
// this test point locks down flag storage file version number query api
fn test_storage_version_query() {
- let _ro_files = create_test_storage_files(true);
assert_eq!(get_storage_file_version("./tests/package.map").unwrap(), 1);
assert_eq!(get_storage_file_version("./tests/flag.map").unwrap(), 1);
assert_eq!(get_storage_file_version("./tests/flag.val").unwrap(), 1);
diff --git a/tools/aconfig/aconfig_storage_read_api/src/mapped_file.rs b/tools/aconfig/aconfig_storage_read_api/src/mapped_file.rs
index 09ecdb6..86c6a1b 100644
--- a/tools/aconfig/aconfig_storage_read_api/src/mapped_file.rs
+++ b/tools/aconfig/aconfig_storage_read_api/src/mapped_file.rs
@@ -14,7 +14,7 @@
* limitations under the License.
*/
-use std::fs::{self, File};
+use std::fs::File;
use std::io::{BufReader, Read};
use anyhow::anyhow;
@@ -56,26 +56,16 @@
Err(StorageFileNotFound(anyhow!("Storage file does not exist for {}", container)))
}
-/// Verify the file is read only and then map it
-fn verify_read_only_and_map(file_path: &str) -> Result<Mmap, AconfigStorageError> {
- // ensure file has read only permission
- let perms = fs::metadata(file_path).unwrap().permissions();
- if !perms.readonly() {
- return Err(MapFileFail(anyhow!("fail to map non read only storage file {}", file_path)));
- }
-
+/// Get the read only memory mapping of a storage file
+///
+/// # Safety
+///
+/// The memory mapped file may have undefined behavior if there are writes to this
+/// file after being mapped. Ensure no writes can happen to this file while this
+/// mapping stays alive.
+unsafe fn map_file(file_path: &str) -> Result<Mmap, AconfigStorageError> {
let file = File::open(file_path)
.map_err(|errmsg| FileReadFail(anyhow!("Failed to open file {}: {}", file_path, errmsg)))?;
-
- // SAFETY:
- //
- // Mmap constructors are unsafe as it would have undefined behaviors if the file
- // is modified after mapped (https://docs.rs/memmap2/latest/memmap2/struct.Mmap.html).
- //
- // We either have to make this api unsafe or ensure that the file will not be modified
- // which means it is read only. Here in the code, we check explicitly that the file
- // being mapped must only have read permission, otherwise, error out, thus making sure
- // it is safe.
unsafe {
let mapped_file = Mmap::map(&file).map_err(|errmsg| {
MapFileFail(anyhow!("fail to map storage file {}: {}", file_path, errmsg))
@@ -85,16 +75,22 @@
}
/// Get a mapped storage file given the container and file type
-pub fn get_mapped_file(
+///
+/// # Safety
+///
+/// The memory mapped file may have undefined behavior if there are writes to this
+/// file after being mapped. Ensure no writes can happen to this file while this
+/// mapping stays alive.
+pub unsafe fn get_mapped_file(
location_pb_file: &str,
container: &str,
file_type: StorageFileType,
) -> Result<Mmap, AconfigStorageError> {
let files_location = find_container_storage_location(location_pb_file, container)?;
match file_type {
- StorageFileType::PackageMap => verify_read_only_and_map(files_location.package_map()),
- StorageFileType::FlagMap => verify_read_only_and_map(files_location.flag_map()),
- StorageFileType::FlagVal => verify_read_only_and_map(files_location.flag_val()),
+ StorageFileType::PackageMap => unsafe { map_file(files_location.package_map()) },
+ StorageFileType::FlagMap => unsafe { map_file(files_location.flag_map()) },
+ StorageFileType::FlagVal => unsafe { map_file(files_location.flag_val()) },
}
}
@@ -155,14 +151,15 @@
let mut content = Vec::new();
opened_file.read_to_end(&mut content).unwrap();
- let mmaped_file = get_mapped_file(location_pb_file, "system", file_type).unwrap();
+ let mmaped_file =
+ unsafe { get_mapped_file(location_pb_file, "system", file_type).unwrap() };
assert_eq!(mmaped_file[..], content[..]);
}
- fn create_test_storage_files(read_only: bool) -> [NamedTempFile; 4] {
- let package_map = copy_to_temp_file("./tests/package.map", read_only).unwrap();
- let flag_map = copy_to_temp_file("./tests/flag.map", read_only).unwrap();
- let flag_val = copy_to_temp_file("./tests/package.map", read_only).unwrap();
+ fn create_test_storage_files() -> [NamedTempFile; 4] {
+ let package_map = copy_to_temp_file("./tests/package.map").unwrap();
+ let flag_map = copy_to_temp_file("./tests/flag.map").unwrap();
+ let flag_val = copy_to_temp_file("./tests/package.map").unwrap();
let text_proto = format!(
r#"
@@ -185,7 +182,7 @@
#[test]
fn test_mapped_file_contents() {
- let [package_map, flag_map, flag_val, pb_file] = create_test_storage_files(true);
+ let [package_map, flag_map, flag_val, pb_file] = create_test_storage_files();
let pb_file_path = pb_file.path().display().to_string();
map_and_verify(
&pb_file_path,
@@ -203,35 +200,4 @@
&flag_val.path().display().to_string(),
);
}
-
- #[test]
- fn test_map_non_read_only_file() {
- let [package_map, flag_map, flag_val, pb_file] = create_test_storage_files(false);
- let pb_file_path = pb_file.path().display().to_string();
- let error =
- get_mapped_file(&pb_file_path, "system", StorageFileType::PackageMap).unwrap_err();
- assert_eq!(
- format!("{:?}", error),
- format!(
- "MapFileFail(fail to map non read only storage file {})",
- package_map.path().display()
- )
- );
- let error = get_mapped_file(&pb_file_path, "system", StorageFileType::FlagMap).unwrap_err();
- assert_eq!(
- format!("{:?}", error),
- format!(
- "MapFileFail(fail to map non read only storage file {})",
- flag_map.path().display()
- )
- );
- let error = get_mapped_file(&pb_file_path, "system", StorageFileType::FlagVal).unwrap_err();
- assert_eq!(
- format!("{:?}", error),
- format!(
- "MapFileFail(fail to map non read only storage file {})",
- flag_val.path().display()
- )
- );
- }
}
diff --git a/tools/aconfig/aconfig_storage_read_api/src/test_utils.rs b/tools/aconfig/aconfig_storage_read_api/src/test_utils.rs
index ff72499..84f31aa 100644
--- a/tools/aconfig/aconfig_storage_read_api/src/test_utils.rs
+++ b/tools/aconfig/aconfig_storage_read_api/src/test_utils.rs
@@ -19,14 +19,8 @@
use tempfile::NamedTempFile;
/// Create temp file copy
-pub(crate) fn copy_to_temp_file(source_file: &str, read_only: bool) -> Result<NamedTempFile> {
+pub(crate) fn copy_to_temp_file(source_file: &str) -> Result<NamedTempFile> {
let file = NamedTempFile::new()?;
fs::copy(source_file, file.path())?;
- if read_only {
- let file_name = file.path().display().to_string();
- let mut perms = fs::metadata(file_name).unwrap().permissions();
- perms.set_readonly(true);
- fs::set_permissions(file.path(), perms.clone()).unwrap();
- }
Ok(file)
}
diff --git a/tools/aconfig/aconfig_storage_read_api/tests/storage_read_api_test.cpp b/tools/aconfig/aconfig_storage_read_api/tests/storage_read_api_test.cpp
index 377395a..1d36aae 100644
--- a/tools/aconfig/aconfig_storage_read_api/tests/storage_read_api_test.cpp
+++ b/tools/aconfig/aconfig_storage_read_api/tests/storage_read_api_test.cpp
@@ -33,7 +33,7 @@
class AconfigStorageTest : public ::testing::Test {
protected:
- Result<std::string> copy_to_ro_temp_file(std::string const& source_file) {
+ Result<std::string> copy_to_temp_file(std::string const& source_file) {
auto temp_file = std::string(std::tmpnam(nullptr));
auto content = std::string();
if (!ReadFileToString(source_file, &content)) {
@@ -42,9 +42,6 @@
if (!WriteStringToFile(content, temp_file)) {
return Error() << "failed to copy file: " << source_file;
}
- if (chmod(temp_file.c_str(), S_IRUSR | S_IRGRP | S_IROTH) == -1) {
- return Error() << "failed to make file read only";
- }
return temp_file;
}
@@ -71,9 +68,9 @@
void SetUp() override {
auto const test_dir = android::base::GetExecutableDirectory();
- package_map = *copy_to_ro_temp_file(test_dir + "/package.map");
- flag_map = *copy_to_ro_temp_file(test_dir + "/flag.map");
- flag_val = *copy_to_ro_temp_file(test_dir + "/flag.val");
+ package_map = *copy_to_temp_file(test_dir + "/package.map");
+ flag_map = *copy_to_temp_file(test_dir + "/flag.map");
+ flag_val = *copy_to_temp_file(test_dir + "/flag.val");
storage_record_pb = *write_storage_location_pb_file(
package_map, flag_map, flag_val);
}
@@ -113,27 +110,6 @@
"Unable to find storage files for container vendor");
}
-/// Negative test to lock down the error when mapping a writeable storage file
-TEST_F(AconfigStorageTest, test_writable_storage_file_mapping) {
- ASSERT_TRUE(chmod(package_map.c_str(), 0666) != -1);
- auto mapped_file = private_api::get_mapped_file_impl(
- storage_record_pb, "system", api::StorageFileType::package_map);
- ASSERT_FALSE(mapped_file.ok());
- ASSERT_EQ(mapped_file.error().message(), "cannot map writeable file");
-
- ASSERT_TRUE(chmod(flag_map.c_str(), 0666) != -1);
- mapped_file = private_api::get_mapped_file_impl(
- storage_record_pb, "system", api::StorageFileType::flag_map);
- ASSERT_FALSE(mapped_file.ok());
- ASSERT_EQ(mapped_file.error().message(), "cannot map writeable file");
-
- ASSERT_TRUE(chmod(flag_val.c_str(), 0666) != -1);
- mapped_file = private_api::get_mapped_file_impl(
- storage_record_pb, "system", api::StorageFileType::flag_val);
- ASSERT_FALSE(mapped_file.ok());
- ASSERT_EQ(mapped_file.error().message(), "cannot map writeable file");
-}
-
/// Test to lock down storage package offset query api
TEST_F(AconfigStorageTest, test_package_offset_query) {
auto mapped_file = private_api::get_mapped_file_impl(
diff --git a/tools/aconfig/aconfig_storage_read_api/tests/storage_read_api_test.rs b/tools/aconfig/aconfig_storage_read_api/tests/storage_read_api_test.rs
index eb4d54d..afcd5a7 100644
--- a/tools/aconfig/aconfig_storage_read_api/tests/storage_read_api_test.rs
+++ b/tools/aconfig/aconfig_storage_read_api/tests/storage_read_api_test.rs
@@ -9,20 +9,16 @@
use std::fs;
use tempfile::NamedTempFile;
- pub fn copy_to_ro_temp_file(source_file: &str) -> NamedTempFile {
+ pub fn copy_to_temp_file(source_file: &str) -> NamedTempFile {
let file = NamedTempFile::new().unwrap();
fs::copy(source_file, file.path()).unwrap();
- let file_name = file.path().display().to_string();
- let mut perms = fs::metadata(file_name).unwrap().permissions();
- perms.set_readonly(true);
- fs::set_permissions(file.path(), perms.clone()).unwrap();
file
}
fn create_test_storage_files() -> [NamedTempFile; 4] {
- let package_map = copy_to_ro_temp_file("./package.map");
- let flag_map = copy_to_ro_temp_file("./flag.map");
- let flag_val = copy_to_ro_temp_file("./flag.val");
+ let package_map = copy_to_temp_file("./package.map");
+ let flag_map = copy_to_temp_file("./flag.map");
+ let flag_val = copy_to_temp_file("./flag.val");
let text_proto = format!(
r#"
@@ -47,8 +43,11 @@
fn test_unavailable_stoarge() {
let [_package_map, _flag_map, _flag_val, pb_file] = create_test_storage_files();
let pb_file_path = pb_file.path().display().to_string();
- let err =
- get_mapped_file(&pb_file_path, "vendor", StorageFileType::PackageMap).unwrap_err();
+ // SAFETY:
+ // The safety here is ensured as the test process will not write to temp storage file
+ let err = unsafe {
+ get_mapped_file(&pb_file_path, "vendor", StorageFileType::PackageMap).unwrap_err()
+ };
assert_eq!(
format!("{:?}", err),
"StorageFileNotFound(Storage file does not exist for vendor)"
@@ -59,8 +58,11 @@
fn test_package_offset_query() {
let [_package_map, _flag_map, _flag_val, pb_file] = create_test_storage_files();
let pb_file_path = pb_file.path().display().to_string();
- let package_mapped_file =
- get_mapped_file(&pb_file_path, "system", StorageFileType::PackageMap).unwrap();
+ // SAFETY:
+ // The safety here is ensured as the test process will not write to temp storage file
+ let package_mapped_file = unsafe {
+ get_mapped_file(&pb_file_path, "system", StorageFileType::PackageMap).unwrap()
+ };
let package_offset =
get_package_offset(&package_mapped_file, "com.android.aconfig.storage.test_1")
@@ -88,8 +90,12 @@
fn test_none_exist_package_offset_query() {
let [_package_map, _flag_map, _flag_val, pb_file] = create_test_storage_files();
let pb_file_path = pb_file.path().display().to_string();
- let package_mapped_file =
- get_mapped_file(&pb_file_path, "system", StorageFileType::PackageMap).unwrap();
+ // SAFETY:
+ // The safety here is ensured as the test process will not write to temp storage file
+ let package_mapped_file = unsafe {
+ get_mapped_file(&pb_file_path, "system", StorageFileType::PackageMap).unwrap()
+ };
+
let package_offset_option =
get_package_offset(&package_mapped_file, "com.android.aconfig.storage.test_3").unwrap();
assert_eq!(package_offset_option, None);
@@ -99,8 +105,10 @@
fn test_flag_offset_query() {
let [_package_map, _flag_map, _flag_val, pb_file] = create_test_storage_files();
let pb_file_path = pb_file.path().display().to_string();
+ // SAFETY:
+ // The safety here is ensured as the test process will not write to temp storage file
let flag_mapped_file =
- get_mapped_file(&pb_file_path, "system", StorageFileType::FlagMap).unwrap();
+ unsafe { get_mapped_file(&pb_file_path, "system", StorageFileType::FlagMap).unwrap() };
let baseline = vec![
(0, "enabled_ro", 1u16),
@@ -123,9 +131,10 @@
fn test_none_exist_flag_offset_query() {
let [_package_map, _flag_map, _flag_val, pb_file] = create_test_storage_files();
let pb_file_path = pb_file.path().display().to_string();
+ // SAFETY:
+ // The safety here is ensured as the test process will not write to temp storage file
let flag_mapped_file =
- get_mapped_file(&pb_file_path, "system", StorageFileType::FlagMap).unwrap();
-
+ unsafe { get_mapped_file(&pb_file_path, "system", StorageFileType::FlagMap).unwrap() };
let flag_offset_option = get_flag_offset(&flag_mapped_file, 0, "none_exist").unwrap();
assert_eq!(flag_offset_option, None);
@@ -137,9 +146,10 @@
fn test_boolean_flag_value_query() {
let [_package_map, _flag_map, _flag_val, pb_file] = create_test_storage_files();
let pb_file_path = pb_file.path().display().to_string();
+ // SAFETY:
+ // The safety here is ensured as the test process will not write to temp storage file
let flag_value_file =
- get_mapped_file(&pb_file_path, "system", StorageFileType::FlagVal).unwrap();
-
+ unsafe { get_mapped_file(&pb_file_path, "system", StorageFileType::FlagVal).unwrap() };
let baseline: Vec<bool> = vec![false; 8];
for (offset, expected_value) in baseline.into_iter().enumerate() {
let flag_value = get_boolean_flag_value(&flag_value_file, offset as u32).unwrap();
@@ -151,9 +161,10 @@
fn test_invalid_boolean_flag_value_query() {
let [_package_map, _flag_map, _flag_val, pb_file] = create_test_storage_files();
let pb_file_path = pb_file.path().display().to_string();
+ // SAFETY:
+ // The safety here is ensured as the test process will not write to temp storage file
let flag_value_file =
- get_mapped_file(&pb_file_path, "system", StorageFileType::FlagVal).unwrap();
-
+ unsafe { get_mapped_file(&pb_file_path, "system", StorageFileType::FlagVal).unwrap() };
let err = get_boolean_flag_value(&flag_value_file, 8u32).unwrap_err();
assert_eq!(
format!("{:?}", err),