Merge changes I4fd4c57a,I719965ff,I91a8a7f4 (971821fb) · Commits · e / os / android_packages_modules_DnsResolver

Android.bp

+15 −36

Original line number	Diff line number	Diff line
		@@ -326,24 +326,25 @@ filegroup {
		],
		}

		rust_ffi_static {
		name: "libdoh_ffi",
		crate_name: "doh",
		srcs: ["doh/doh.rs"],
		edition: "2018",

		rlibs: [
		doh_rust_deps = [
		"libandroid_logger",
		"libanyhow",
		"libbase64_rust",
		"libfutures",
		"liblibc",
		"liblog_rust",
		"libquiche",
		"libring",
		"libtokio",
		"liburl",
		],
		]

		rust_ffi_static {
		name: "libdoh_ffi",
		crate_name: "doh",
		srcs: ["doh/doh.rs"],
		edition: "2018",

		rlibs: doh_rust_deps + ["libquiche"],
		prefer_rlib: true,

		shared_libs: [
		@@ -368,18 +369,7 @@ rust_test {
		// Used to enable root permission for the test.
		// TODO: remove after 'require_root' is supported in rust_test.
		test_config_template: ":resolv_rust_test_config_template",
		rustlibs: [
		"libandroid_logger",
		"libanyhow",
		"libbase64_rust",
		"libfutures",
		"liblibc",
		"liblog_rust",
		"libquiche_static",
		"libring",
		"libtokio",
		"liburl",
		],
		rustlibs: doh_rust_deps + ["libquiche_static"],
		min_sdk_version: "29",
		}

		@@ -390,18 +380,7 @@ rust_ffi_static {
		srcs: ["doh/doh.rs"],
		edition: "2018",

		rlibs: [
		"libandroid_logger",
		"libanyhow",
		"libbase64_rust",
		"libfutures",
		"liblibc",
		"liblog_rust",
		"libquiche_static",
		"libring",
		"libtokio",
		"liburl",
		],
		rlibs: doh_rust_deps + ["libquiche_static"],
		prefer_rlib: true,
		// TODO(b/194022174), for unit tests to run on the Android 10 platform,
		// libunwind must be statically linked.

DnsResolver.cpp

+1 −1

Original line number	Diff line number	Diff line
		@@ -33,7 +33,7 @@ bool resolv_init(const ResolverNetdCallbacks* callbacks) {
		// TODO(b/170539625): restore log level to WARNING after clarifying flaky tests.
		const bool isDebug = isUserDebugBuild();
		resolv_set_log_severity(isDebug ? android::base::DEBUG : android::base::WARNING);
		doh_init_logger(isDebug ? LOG_LEVEL_DEBUG : LOG_LEVEL_WARN);
		doh_init_logger(isDebug ? DOH_LOG_LEVEL_DEBUG : DOH_LOG_LEVEL_WARN);
		using android::net::gApiLevel;
		gApiLevel = getApiLevel();
		using android::net::gResNetdCallbacks;

PrivateDnsConfiguration.cpp

+1 −1

Original line number	Diff line number	Diff line
		@@ -510,7 +510,7 @@ ssize_t PrivateDnsConfiguration::dohQuery(unsigned netId, const Slice query, con
		{
		std::lock_guard guard(mPrivateDnsLock);
		// It's safe because mDohDispatcher won't be deleted after initializing.
		if (mDohDispatcher == nullptr) return RESULT_CAN_NOT_SEND;
		if (mDohDispatcher == nullptr) return DOH_RESULT_CAN_NOT_SEND;
		}
		return doh_query(mDohDispatcher, netId, query.base(), query.size(), answer.base(),
		answer.size(), timeoutMs);

doh.h

+11 −8

Original line number	Diff line number	Diff line
		@@ -26,28 +26,28 @@
		#include <sys/types.h>

		/// The return code of doh_query means that there is no answer.
		static const ssize_t RESULT_INTERNAL_ERROR = -1;
		static const ssize_t DOH_RESULT_INTERNAL_ERROR = -1;

		/// The return code of doh_query means that query can't be sent.
		static const ssize_t RESULT_CAN_NOT_SEND = -2;
		static const ssize_t DOH_RESULT_CAN_NOT_SEND = -2;

		/// The return code of doh_query to indicate that the query timed out.
		static const ssize_t RESULT_TIMEOUT = -255;
		static const ssize_t DOH_RESULT_TIMEOUT = -255;

		/// The error log level.
		static const uint32_t LOG_LEVEL_ERROR = 0;
		static const uint32_t DOH_LOG_LEVEL_ERROR = 0;

		/// The warning log level.
		static const uint32_t LOG_LEVEL_WARN = 1;
		static const uint32_t DOH_LOG_LEVEL_WARN = 1;

		/// The info log level.
		static const uint32_t LOG_LEVEL_INFO = 2;
		static const uint32_t DOH_LOG_LEVEL_INFO = 2;

		/// The debug log level.
		static const uint32_t LOG_LEVEL_DEBUG = 3;
		static const uint32_t DOH_LOG_LEVEL_DEBUG = 3;

		/// The trace log level.
		static const uint32_t LOG_LEVEL_TRACE = 4;
		static const uint32_t DOH_LOG_LEVEL_TRACE = 4;

		/// Context for a running DoH engine.
		struct DohDispatcher;
		@@ -60,9 +60,12 @@ using TagSocketCallback = void (*)(int32_t sock);
		extern "C" {

		/// Performs static initialization for android logger.
		/// If an invalid level is passed, defaults to logging errors only.
		/// If called more than once, it will have no effect on subsequent calls.
		void doh_init_logger(uint32_t level);

		/// Set the log level.
		/// If an invalid level is passed, defaults to logging errors only.
		void doh_set_log_level(uint32_t level);

		/// Performs the initialization for the DoH engine.

doh/boot_time.rs

0 → 100644

+206 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2021 The Android Open Source Project
		*
		* 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.
		*/

		//! This module provides a time hack to work around the broken `Instant` type in the standard
		//! library.
		//!
		//! `BootTime` looks like `Instant`, but represents `CLOCK_BOOTTIME` instead of `CLOCK_MONOTONIC`.
		//! This means the clock increments correctly during suspend.

		pub use std::time::Duration;

		use std::io;

		use futures::future::pending;
		use std::convert::TryInto;
		use std::fmt;
		use std::future::Future;
		use std::os::unix::io::{AsRawFd, RawFd};
		use tokio::io::unix::AsyncFd;
		use tokio::select;

		/// Represents a moment in time, with differences including time spent in suspend. Only valid for
		/// a single boot - numbers from different boots are incomparable.
		#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
		pub struct BootTime {
		d: Duration,
		}

		// Return an error with the same structure as tokio::time::timeout to facilitate migration off it,
		// and hopefully some day back to it.
		/// Error returned by timeout
		#[derive(Debug, PartialEq)]
		pub struct Elapsed(());

		impl fmt::Display for Elapsed {
		fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
		"deadline has elapsed".fmt(fmt)
		}
		}

		impl std::error::Error for Elapsed {}

		impl BootTime {
		/// Gets a `BootTime` representing the current moment in time.
		pub fn now() -> BootTime {
		let mut t = libc::timespec { tv_sec: 0, tv_nsec: 0 };
		// # Safety
		// clock_gettime's only action will be to possibly write to the pointer provided,
		// and no borrows exist from that object other than the &mut used to construct the pointer
		// itself.
		if unsafe { libc::clock_gettime(libc::CLOCK_BOOTTIME, &mut t as *mut libc::timespec) } != 0
		{
		panic!(
		"libc::clock_gettime(libc::CLOCK_BOOTTIME) failed: {:?}",
		io::Error::last_os_error()
		);
		}
		BootTime { d: Duration::new(t.tv_sec as u64, t.tv_nsec as u32) }
		}

		/// Determines how long has elapsed since the provided `BootTime`.
		pub fn elapsed(&self) -> Duration {
		BootTime::now().checked_duration_since(*self).unwrap()
		}

		/// Add a specified time delta to a moment in time. If this would overflow the representation,
		/// returns `None`.
		pub fn checked_add(&self, duration: Duration) -> Option<BootTime> {
		Some(BootTime { d: self.d.checked_add(duration)? })
		}

		/// Finds the difference from an earlier point in time. If the provided time is later, returns
		/// `None`.
		pub fn checked_duration_since(&self, earlier: BootTime) -> Option<Duration> {
		self.d.checked_sub(earlier.d)
		}
		}

		struct TimerFd(RawFd);

		impl Drop for TimerFd {
		fn drop(&mut self) {
		// # Safety
		// The fd is owned by the TimerFd struct, and no memory access occurs as a result of this
		// call.
		unsafe {
		libc::close(self.0);
		}
		}
		}

		impl AsRawFd for TimerFd {
		fn as_raw_fd(&self) -> RawFd {
		self.0
		}
		}

		impl TimerFd {
		fn create() -> io::Result<Self> {
		// # Unsafe
		// This libc call will either give us back a file descriptor or fail, it does not act on
		// memory or resources.
		let raw = unsafe {
		libc::timerfd_create(libc::CLOCK_BOOTTIME, libc::TFD_NONBLOCK \| libc::TFD_CLOEXEC)
		};
		if raw < 0 {
		return Err(io::Error::last_os_error());
		}
		Ok(Self(raw))
		}

		fn set(&self, duration: Duration) {
		let timer = libc::itimerspec {
		it_interval: libc::timespec { tv_sec: 0, tv_nsec: 0 },
		it_value: libc::timespec {
		tv_sec: duration.as_secs().try_into().unwrap(),
		tv_nsec: duration.subsec_nanos().try_into().unwrap(),
		},
		};
		// # Unsafe
		// We own `timer` and there are no borrows to it other than the pointer we pass to
		// timerfd_settime. timerfd_settime is explicitly documented to handle a null output
		// parameter for its fourth argument by not filling out the output. The fd passed in at
		// self.0 is owned by the `TimerFd` struct, so we aren't breaking anyone else's invariants.
		if unsafe { libc::timerfd_settime(self.0, 0, &timer, std::ptr::null_mut()) } != 0 {
		panic!("timerfd_settime failed: {:?}", io::Error::last_os_error());
		}
		}
		}

		/// Runs the provided future until completion or `duration` has passed on the `CLOCK_BOOTTIME`
		/// clock. In the event of a timeout, returns the elapsed time as an error.
		pub async fn timeout<T>(duration: Duration, future: impl Future<Output = T>) -> Result<T, Elapsed> {
		// Ideally, all timeouts in a runtime would share a timerfd. That will be much more
		// straightforwards to implement when moving this functionality into `tokio`.

		// The failure conditions for this are rare (see `man 2 timerfd_create`) and the caller would
		// not be able to do much in response to them. When integrated into tokio, this would be called
		// during runtime setup.
		let timer_fd = TimerFd::create().unwrap();
		timer_fd.set(duration);
		let async_fd = AsyncFd::new(timer_fd).unwrap();
		select! {
		v = future => Ok(v),
		_ = async_fd.readable() => Err(Elapsed(())),
		}
		}

		/// Provides a future which will complete once the provided duration has passed, as measured by the
		/// `CLOCK_BOOTTIME` clock.
		pub async fn sleep(duration: Duration) {
		assert!(timeout(duration, pending::<()>()).await.is_err());
		}

		#[test]
		fn monotonic_smoke() {
		for _ in 0..1000 {
		// If BootTime is not monotonic, .elapsed() will panic on the unwrap.
		BootTime::now().elapsed();
		}
		}

		#[test]
		fn round_trip() {
		use std::thread::sleep;
		for _ in 0..10 {
		let start = BootTime::now();
		sleep(Duration::from_millis(1));
		let end = BootTime::now();
		let delta = end.checked_duration_since(start).unwrap();
		assert_eq!(start.checked_add(delta).unwrap(), end);
		}
		}

		#[tokio::test]
		async fn timeout_drift() {
		let delta = Duration::from_millis(20);
		for _ in 0..10 {
		let start = BootTime::now();
		assert!(timeout(delta, pending::<()>()).await.is_err());
		let taken = start.elapsed();
		let drift = if taken > delta { taken - delta } else { delta - taken };
		assert!(drift < Duration::from_millis(5));
		}

		for _ in 0..10 {
		let start = BootTime::now();
		sleep(delta).await;
		let taken = start.elapsed();
		let drift = if taken > delta { taken - delta } else { delta - taken };
		assert!(drift < Duration::from_millis(5));
		}
		}