Support DNS64 synthesis using externally-discovered prefixes. am: 346737c0d3 (fd0d47e2) · Commits · e / os / android_packages_modules_DnsResolver

Android.bp

+1 −1

Original line number	Diff line number	Diff line
		@@ -120,7 +120,7 @@ cc_library {
		// Link most things statically to minimize our dependence on system ABIs.
		stl: "libc++_static",
		static_libs: [
		"dnsresolver_aidl_interface-ndk_platform",
		"dnsresolver_aidl_interface-unstable-ndk_platform",
		"libbase",
		"libcutils",
		"libnetdutils",

Dns64Configuration.cpp

+45 −6

Original line number	Diff line number	Diff line
		@@ -216,10 +216,15 @@ bool Dns64Configuration::shouldContinueDiscovery(const Dns64Config& cfg) {
		}

		void Dns64Configuration::removeDns64Config(unsigned netId) REQUIRES(mMutex) {
		IPPrefix prefix = getPrefix64Locked(netId);
		mDns64Configs.erase(netId);
		if (!prefix.isUninitialized()) {
		reportNat64PrefixStatus(netId, PREFIX_REMOVED, prefix);
		const auto& iter = mDns64Configs.find(netId);
		if (iter == mDns64Configs.end()) return;

		Dns64Config cfg = iter->second;
		mDns64Configs.erase(iter);

		// Only report a prefix removed event if the prefix was discovered, not if it was set.
		if (cfg.isFromPrefixDiscovery() && !cfg.prefix64.isUninitialized()) {
		reportNat64PrefixStatus(netId, PREFIX_REMOVED, cfg.prefix64);
		}
		}

		@@ -231,9 +236,43 @@ void Dns64Configuration::recordDns64Config(const Dns64Config& cfg) {
		mDns64Configs.emplace(std::make_pair(cfg.netId, cfg));

		reportNat64PrefixStatus(cfg.netId, PREFIX_ADDED, cfg.prefix64);
		}

		int Dns64Configuration::setPrefix64(unsigned netId, const IPPrefix* pfx) {
		if (pfx->isUninitialized() \|\| pfx->family() != AF_INET6 \|\| pfx->length() != 96) {
		return -EINVAL;
		}

		std::lock_guard guard(mMutex);

		// This method may only be called if prefix discovery has been stopped or was never started.
		auto iter = mDns64Configs.find(netId);
		if (iter != mDns64Configs.end()) {
		if (iter->second.isFromPrefixDiscovery()) {
		return -EEXIST;
		} else {
		mDns64Configs.erase(iter);
		}
		}

		Dns64Config cfg(kNoDiscoveryId, netId);
		cfg.prefix64 = *pfx;
		mDns64Configs.emplace(std::make_pair(netId, cfg));

		return 0;
		}

		int Dns64Configuration::clearPrefix64(unsigned netId) {
		std::lock_guard guard(mMutex);

		const auto& iter = mDns64Configs.find(netId);
		if (iter == mDns64Configs.end() \|\| iter->second.isFromPrefixDiscovery()) {
		return -ENOENT;
		}

		mDns64Configs.erase(iter);

		// TODO: consider extending INetdEventListener to report the DNS64 prefix
		// up to ConnectivityService to potentially include this in LinkProperties.
		return 0;
		}

		} // namespace net

Dns64Configuration.h

+12 −1

Original line number	Diff line number	Diff line
		@@ -82,6 +82,9 @@ class Dns64Configuration {
		void stopPrefixDiscovery(unsigned netId);
		netdutils::IPPrefix getPrefix64(unsigned netId) const;

		int setPrefix64(unsigned netId, const netdutils::IPPrefix* pfx);
		int clearPrefix64(unsigned netId);

		void dump(netdutils::DumpWriter& dw, unsigned netId);

		private:
		@@ -89,16 +92,24 @@ class Dns64Configuration {
		Dns64Config(unsigned pseudoRandomId, unsigned network)
		: discoveryId(pseudoRandomId), netId(network) {}

		// ID of the discovery operation, or kNoDiscoveryId if no discovery was performed (i.e., the
		// prefix was discovered and passed in via setPrefix64).
		const unsigned int discoveryId;
		const unsigned int netId;
		netdutils::IPPrefix prefix64{};

		bool isFromPrefixDiscovery() const { return discoveryId != kNoDiscoveryId; }
		};

		static constexpr int kNoDiscoveryId = 0;

		enum { PREFIX_REMOVED, PREFIX_ADDED };

		static bool doRfc7050PrefixDiscovery(const android_net_context& netcontext, Dns64Config* cfg);

		unsigned getNextId() REQUIRES(mMutex) { return mNextId++; }
		// Picks the next discovery ID. Never returns kNoDiscoveryId.
		unsigned getNextId() REQUIRES(mMutex) { return ++mNextId ? mNextId : ++mNextId; }

		netdutils::IPPrefix getPrefix64Locked(unsigned netId) const REQUIRES(mMutex);
		bool isDiscoveryInProgress(const Dns64Config& cfg) const REQUIRES(mMutex);
		bool reportNat64PrefixStatus(unsigned netId, bool added, const netdutils::IPPrefix& pfx)

DnsResolverService.cpp

+16 −0

Original line number	Diff line number	Diff line
		@@ -39,6 +39,7 @@ using aidl::android::net::ResolverParamsParcel;
		using android::base::Join;
		using android::base::StringPrintf;
		using android::netdutils::DumpWriter;
		using android::netdutils::IPPrefix;

		namespace android {
		namespace net {
		@@ -240,6 +241,21 @@ binder_status_t DnsResolverService::dump(int fd, const char** args, uint32_t num
		return statusFromErrcode(res);
		}

		::ndk::ScopedAStatus DnsResolverService::setPrefix64(int netId, const std::string& stringPrefix) {
		ENFORCE_NETWORK_STACK_PERMISSIONS();

		if (stringPrefix.empty()) {
		return statusFromErrcode(gDnsResolv->resolverCtrl.clearPrefix64(netId));
		}

		IPPrefix prefix;
		if (!IPPrefix::forString(stringPrefix, &prefix)) {
		return statusFromErrcode(-EINVAL);
		}

		return statusFromErrcode(gDnsResolv->resolverCtrl.setPrefix64(netId, &prefix));
		}

		::ndk::ScopedAStatus DnsResolverService::setLogSeverity(int32_t logSeverity) {
		ENFORCE_NETWORK_STACK_PERMISSIONS();

DnsResolverService.h

+2 −1

Original line number	Diff line number	Diff line
		@@ -56,7 +56,8 @@ class DnsResolverService : public aidl::android::net::BnDnsResolver {
		::ndk::ScopedAStatus startPrefix64Discovery(int32_t netId) override;
		::ndk::ScopedAStatus stopPrefix64Discovery(int32_t netId) override;
		// (internal use only)
		::ndk::ScopedAStatus getPrefix64(int netId, std::string* stringPrefix) override;
		::ndk::ScopedAStatus getPrefix64(int32_t netId, std::string* stringPrefix) override;
		::ndk::ScopedAStatus setPrefix64(int32_t netId, const std::string& stringPrefix) override;

		// Debug log command
		::ndk::ScopedAStatus setLogSeverity(int32_t logSeverity) override;