Snap for 10755155 from 99de1f690b7ecaf09803bf7273facec58cd406f5 to mainline-art-release (af3ce770) · Commits · e / os / android_packages_modules_DnsResolver

Android.bp

+1 −0

Original line number	Diff line number	Diff line
		@@ -230,6 +230,7 @@ cc_library {
		"libprotobuf-cpp-lite",
		"libstatslog_resolv",
		"libsysutils",
		"libutils",
		"netd_event_listener_interface-lateststable-ndk",
		"server_configurable_flags",
		"stats_proto",

Dns64Configuration.cpp

+10 −7

Original line number	Diff line number	Diff line
		@@ -24,6 +24,7 @@
		#include <netdutils/DumpWriter.h>
		#include <netdutils/InternetAddresses.h>
		#include <netdutils/ThreadUtil.h>
		#include <utils/StrongPointer.h>
		#include <thread>
		#include <utility>

		@@ -36,6 +37,7 @@

		namespace android {

		using android::sp;
		using netdutils::DumpWriter;
		using netdutils::IPAddress;
		using netdutils::IPPrefix;
		@@ -61,8 +63,9 @@ void Dns64Configuration::startPrefixDiscovery(unsigned netId) {
		// Emplace a copy of \|cfg\| in the map.
		mDns64Configs.emplace(std::make_pair(netId, cfg));

		const sp<Dns64Configuration> thiz = sp<Dns64Configuration>::fromExisting(this);
		// Note that capturing \|cfg\| in this lambda creates a copy.
		std::thread discovery_thread([this, cfg, netId] {
		std::thread discovery_thread([thiz, cfg, netId] {
		setThreadName(fmt::format("Nat64Pfx_{}", netId));

		// Make a mutable copy rather than mark the whole lambda mutable.
		@@ -75,28 +78,28 @@ void Dns64Configuration::startPrefixDiscovery(unsigned netId) {
		.build();

		while (true) {
		if (!this->shouldContinueDiscovery(evalCfg)) break;
		if (!thiz->shouldContinueDiscovery(evalCfg)) break;

		android_net_context netcontext{};
		mGetNetworkContextCallback(evalCfg.netId, 0, &netcontext);
		thiz->mGetNetworkContextCallback(evalCfg.netId, 0, &netcontext);

		// Prefix discovery must bypass private DNS because in strict mode
		// the server generally won't know the NAT64 prefix.
		netcontext.flags \|= NET_CONTEXT_FLAG_USE_LOCAL_NAMESERVERS;
		if (doRfc7050PrefixDiscovery(netcontext, &evalCfg)) {
		this->recordDns64Config(evalCfg);
		thiz->recordDns64Config(evalCfg);
		break;
		}

		if (!this->shouldContinueDiscovery(evalCfg)) break;
		if (!thiz->shouldContinueDiscovery(evalCfg)) break;

		if (!backoff.hasNextTimeout()) break;
		{
		std::unique_lock<std::mutex> cvGuard(mMutex);
		std::unique_lock<std::mutex> cvGuard(thiz->mMutex);
		// TODO: Consider some chrono math, combined with wait_until()
		// perhaps, to prevent early re-resolves from the removal of
		// other netids with IPv6-only nameservers.
		mCv.wait_for(cvGuard, backoff.getNextTimeout());
		thiz->mCv.wait_for(cvGuard, backoff.getNextTimeout());
		}
		}
		});

Dns64Configuration.h

+2 −1

Original line number	Diff line number	Diff line
		@@ -27,6 +27,7 @@
		#include <android-base/thread_annotations.h>
		#include <netdutils/DumpWriter.h>
		#include <netdutils/InternetAddresses.h>
		#include <utils/RefBase.h>

		struct android_net_context;

		@@ -48,7 +49,7 @@ namespace net {
		* Thread-safety: All public methods in this class MUST be thread-safe.
		* (In other words: this class handles all its locking privately.)
		*/
		class Dns64Configuration {
		class Dns64Configuration : virtual public RefBase {
		public:
		// Simple data struct for passing back packet NAT64 prefix event information to the
		// Dns64PrefixCallback callback.

DnsProxyListener.cpp

+4 −5

Original line number	Diff line number	Diff line
		@@ -70,20 +70,19 @@ using std::span;

		namespace android {

		using netdutils::MAX_QUERIES_IN_TOTAL;
		using netdutils::MAX_QUERIES_PER_UID;
		using netdutils::ResponseCode;
		using netdutils::Stopwatch;

		namespace net {
		namespace {

		// Limits the number of outstanding DNS queries by client UID.
		constexpr int MAX_QUERIES_PER_UID = 256;

		android::netdutils::OperationLimiter<uid_t> queryLimiter(MAX_QUERIES_PER_UID);

		bool startQueryLimiter(uid_t uid) {
		const int globalLimit =
		android::net::Experiments::getInstance()->getFlag("max_queries_global", INT_MAX);
		const int globalLimit = android::net::Experiments::getInstance()->getFlag("max_queries_global",
		MAX_QUERIES_IN_TOTAL);
		return queryLimiter.start(uid, globalLimit);
		}

OperationLimiter.h

+7 −2

Original line number	Diff line number	Diff line
		@@ -28,6 +28,11 @@
		namespace android {
		namespace netdutils {

		// Limits the number of outstanding DNS queries by client UID.
		constexpr int MAX_QUERIES_PER_UID = 256;
		// Limits the total number of outstanding DNS queries.
		constexpr int MAX_QUERIES_IN_TOTAL = 2500;

		// Tracks the number of operations in progress on behalf of a particular key or
		// ID, rejecting further attempts to start new operations after a configurable
		// limit has been reached.
		@@ -56,11 +61,11 @@ class OperationLimiter {
		//
		// Note: each successful start(key) must be matched by exactly one call to
		// finish(key).
		bool start(KeyType key, int globalLimit = INT_MAX) EXCLUDES(mMutex) {
		bool start(KeyType key, int globalLimit = MAX_QUERIES_IN_TOTAL) EXCLUDES(mMutex) {
		std::lock_guard lock(mMutex);
		if (globalLimit < mLimitPerKey) {
		LOG(ERROR) << "Misconfiguration on max_queries_global " << globalLimit;
		globalLimit = INT_MAX;
		globalLimit = MAX_QUERIES_IN_TOTAL;
		}
		if (mGlobalCounter >= globalLimit) {
		// Oh, no!