Merge "Check remaining bytes before attempting to read from buffer" into main (45845843) · Commits · e / os / android_build

tools/aconfig/aconfig_storage_file/src/lib.rs

+81 −18

Original line number	Diff line number	Diff line
		@@ -228,10 +228,14 @@ pub(crate) fn get_bucket_index(val: &[u8], num_buckets: u32) -> u32 {

		/// Read and parse bytes as u8
		pub fn read_u8_from_bytes(buf: &[u8], head: &mut usize) -> Result<u8, AconfigStorageError> {
		let val =
		u8::from_le_bytes(buf[head..head + 1].try_into().map_err(\|errmsg\| {
		BytesParseFail(anyhow!("fail to parse u8 from bytes: {}", errmsg))
		})?);
		let val = u8::from_le_bytes(
		buf.get(head..head + 1)
		.ok_or(AconfigStorageError::BytesParseFail(anyhow!(
		"fail to parse u8 from bytes: access out of bounds"
		)))?
		.try_into()
		.map_err(\|errmsg\| BytesParseFail(anyhow!("fail to parse u8 from bytes: {}", errmsg)))?,
		);
		*head += 1;
		Ok(val)
		}
		@@ -241,10 +245,16 @@ pub(crate) fn read_u16_from_bytes(
		buf: &[u8],
		head: &mut usize,
		) -> Result<u16, AconfigStorageError> {
		let val =
		u16::from_le_bytes(buf[head..head + 2].try_into().map_err(\|errmsg\| {
		let val = u16::from_le_bytes(
		buf.get(head..head + 2)
		.ok_or(AconfigStorageError::BytesParseFail(anyhow!(
		"fail to parse u16 from bytes: access out of bounds"
		)))?
		.try_into()
		.map_err(\|errmsg\| {
		BytesParseFail(anyhow!("fail to parse u16 from bytes: {}", errmsg))
		})?);
		})?,
		);
		*head += 2;
		Ok(val)
		}
		@@ -256,20 +266,32 @@ pub fn read_u32_from_start_of_bytes(buf: &[u8]) -> Result<u32, AconfigStorageErr

		/// Read and parse bytes as u32
		pub fn read_u32_from_bytes(buf: &[u8], head: &mut usize) -> Result<u32, AconfigStorageError> {
		let val =
		u32::from_le_bytes(buf[head..head + 4].try_into().map_err(\|errmsg\| {
		let val = u32::from_le_bytes(
		buf.get(head..head + 4)
		.ok_or(AconfigStorageError::BytesParseFail(anyhow!(
		"fail to parse u32 from bytes: access out of bounds"
		)))?
		.try_into()
		.map_err(\|errmsg\| {
		BytesParseFail(anyhow!("fail to parse u32 from bytes: {}", errmsg))
		})?);
		})?,
		);
		*head += 4;
		Ok(val)
		}

		// Read and parse bytes as u64
		pub fn read_u64_from_bytes(buf: &[u8], head: &mut usize) -> Result<u64, AconfigStorageError> {
		let val =
		u64::from_le_bytes(buf[head..head + 8].try_into().map_err(\|errmsg\| {
		let val = u64::from_le_bytes(
		buf.get(head..head + 8)
		.ok_or(AconfigStorageError::BytesParseFail(anyhow!(
		"fail to parse u64 from bytes: access out of bounds"
		)))?
		.try_into()
		.map_err(\|errmsg\| {
		BytesParseFail(anyhow!("fail to parse u64 from bytes: {}", errmsg))
		})?);
		})?,
		);
		*head += 8;
		Ok(val)
		}
		@@ -280,7 +302,20 @@ pub(crate) fn read_str_from_bytes(
		head: &mut usize,
		) -> Result<String, AconfigStorageError> {
		let num_bytes = read_u32_from_bytes(buf, head)? as usize;
		let val = String::from_utf8(buf[head..head + num_bytes].to_vec())
		// TODO(opg): Document this limitation and check it when creating files.
		if num_bytes > 1024 {
		return Err(AconfigStorageError::BytesParseFail(anyhow!(
		"fail to parse string from bytes, string is too long (found {}, max is 1024)",
		num_bytes
		)));
		}
		let val = String::from_utf8(
		buf.get(head..head + num_bytes)
		.ok_or(AconfigStorageError::BytesParseFail(anyhow!(
		"fail to parse string from bytes: access out of bounds"
		)))?
		.to_vec(),
		)
		.map_err(\|errmsg\| BytesParseFail(anyhow!("fail to parse string from bytes: {}", errmsg)))?;
		*head += num_bytes;
		Ok(val)
		@@ -532,6 +567,34 @@ mod tests {
		create_test_package_table, write_bytes_to_temp_file,
		};

		#[test]
		fn test_list_flags_with_missing_files_error() {
		let flag_list_error = list_flags("does", "not", "exist").unwrap_err();
		assert_eq!(
		format!("{:?}", flag_list_error),
		format!(
		"FileReadFail(Failed to open file does: No such file or directory (os error 2))"
		)
		);
		}

		#[test]
		fn test_list_flags_with_invalid_files_error() {
		let invalid_bytes: [u8; 3] = [0; 3];
		let package_table = write_bytes_to_temp_file(&invalid_bytes).unwrap();
		let flag_table = write_bytes_to_temp_file(&invalid_bytes).unwrap();
		let flag_value_list = write_bytes_to_temp_file(&invalid_bytes).unwrap();
		let package_table_path = package_table.path().display().to_string();
		let flag_table_path = flag_table.path().display().to_string();
		let flag_value_list_path = flag_value_list.path().display().to_string();
		let flag_list_error =
		list_flags(&package_table_path, &flag_table_path, &flag_value_list_path).unwrap_err();
		assert_eq!(
		format!("{:?}", flag_list_error),
		format!("BytesParseFail(fail to parse u32 from bytes: access out of bounds)")
		);
		}

		#[test]
		// this test point locks down the flag list api
		fn test_list_flag() {