Merge "libbinder: Add getter for max supported FDs" into main (ef9f0459) · Commits · e / os / android_frameworks_native

libs/binder/RpcState.cpp

+12 −30

Original line number	Diff line number	Diff line
		@@ -1231,37 +1231,19 @@ status_t RpcState::validateParcel(const sp<RpcSession>& session, const Parcel& p
		}

		if (rpcFields->mFds && !rpcFields->mFds->empty()) {
		switch (session->getFileDescriptorTransportMode()) {
		case RpcSession::FileDescriptorTransportMode::NONE:
		*errorMsg =
		"Parcel has file descriptors, but no file descriptor transport is enabled";
		auto fileDescriptorTransportMode = session->getFileDescriptorTransportMode();
		size_t maxFdsPerMsg = getRpcTransportModeMaxFds(fileDescriptorTransportMode);
		if (RpcSession::FileDescriptorTransportMode::NONE == fileDescriptorTransportMode) {
		*errorMsg = "Parcel has file descriptors, but no file descriptor transport is enabled";
		return FDS_NOT_ALLOWED;
		case RpcSession::FileDescriptorTransportMode::UNIX: {
		constexpr size_t kMaxFdsPerMsg = 253;
		if (rpcFields->mFds->size() > kMaxFdsPerMsg) {
		std::stringstream ss;
		ss << "Too many file descriptors in Parcel for unix domain socket: "
		<< rpcFields->mFds->size() << " (max is " << kMaxFdsPerMsg << ")";
		*errorMsg = ss.str();
		return BAD_VALUE;
		}
		break;
		}
		case RpcSession::FileDescriptorTransportMode::TRUSTY: {
		// Keep this in sync with trusty_ipc.h!!!
		// We could import that file here on Trusty, but it's not
		// available on Android
		constexpr size_t kMaxFdsPerMsg = 8;
		if (rpcFields->mFds->size() > kMaxFdsPerMsg) {
		if (rpcFields->mFds->size() > maxFdsPerMsg) {
		std::stringstream ss;
		ss << "Too many file descriptors in Parcel for Trusty IPC connection: "
		<< rpcFields->mFds->size() << " (max is " << kMaxFdsPerMsg << ")";
		ss << "Too many file descriptors in Parcel: " << rpcFields->mFds->size() << " (max is "
		<< maxFdsPerMsg << ")";
		*errorMsg = ss.str();
		return BAD_VALUE;
		}
		break;
		}
		}
		}

		return OK;

libs/binder/RpcWireFormat.h

+16 −0

Original line number	Diff line number	Diff line
		@@ -15,6 +15,8 @@
		*/
		#pragma once

		#include <binder/RpcSession.h>

		namespace android {

		#pragma clang diagnostic push
		@@ -167,4 +169,18 @@ static_assert(sizeof(RpcWireReply) == 20);

		#pragma clang diagnostic pop

		static inline size_t getRpcTransportModeMaxFds(RpcSession::FileDescriptorTransportMode mode) {
		switch (mode) {
		case RpcSession::FileDescriptorTransportMode::NONE:
		return 0;
		case RpcSession::FileDescriptorTransportMode::UNIX:
		return 253;
		case RpcSession::FileDescriptorTransportMode::TRUSTY:
		// Keep this in sync with trusty_ipc.h!!!
		// We could import that file here on Trusty, but it's not
		// available on Android
		return 8;
		}
		}

		} // namespace android

libs/binder/tests/binderRpcTest.cpp

+12 −9

Original line number	Diff line number	Diff line
		@@ -42,6 +42,7 @@
		#include <trusty/tipc.h>
		#endif // BINDER_RPC_TO_TRUSTY_TEST

		#include "../RpcWireFormat.h"
		#include "../Utils.h"
		#include "binderRpcTestCommon.h"
		#include "binderRpcTestFixture.h"
		@@ -1061,14 +1062,15 @@ TEST_P(BinderRpc, SendMaxFiles) {
		GTEST_SKIP() << "Would fail trivially (which is tested by BinderRpc::SendFiles)";
		}

		auto transportMode = RpcSession::FileDescriptorTransportMode::UNIX;
		auto proc = createRpcTestSocketServerProcess({
		.clientFileDescriptorTransportMode = RpcSession::FileDescriptorTransportMode::UNIX,
		.serverSupportedFileDescriptorTransportModes =
		{RpcSession::FileDescriptorTransportMode::UNIX},
		.clientFileDescriptorTransportMode = transportMode,
		.serverSupportedFileDescriptorTransportModes = {transportMode},
		});

		size_t maxFds = getRpcTransportModeMaxFds(transportMode);
		std::vector<android::os::ParcelFileDescriptor> files;
		for (int i = 0; i < 253; i++) {
		for (size_t i = 0; i < maxFds; i++) {
		files.emplace_back(android::os::ParcelFileDescriptor(mockFileDescriptor("a")));
		}

		@@ -1078,7 +1080,7 @@ TEST_P(BinderRpc, SendMaxFiles) {

		std::string result;
		EXPECT_TRUE(ReadFdToString(out.get(), &result));
		EXPECT_EQ(result, std::string(253, 'a'));
		EXPECT_EQ(result, std::string(maxFds, 'a'));
		}

		TEST_P(BinderRpc, SendTooManyFiles) {
		@@ -1086,14 +1088,15 @@ TEST_P(BinderRpc, SendTooManyFiles) {
		GTEST_SKIP() << "Would fail trivially (which is tested by BinderRpc::SendFiles)";
		}

		auto transportMode = RpcSession::FileDescriptorTransportMode::UNIX;
		auto proc = createRpcTestSocketServerProcess({
		.clientFileDescriptorTransportMode = RpcSession::FileDescriptorTransportMode::UNIX,
		.serverSupportedFileDescriptorTransportModes =
		{RpcSession::FileDescriptorTransportMode::UNIX},
		.clientFileDescriptorTransportMode = transportMode,
		.serverSupportedFileDescriptorTransportModes = {transportMode},
		});

		size_t maxFds = getRpcTransportModeMaxFds(transportMode);
		std::vector<android::os::ParcelFileDescriptor> files;
		for (int i = 0; i < 254; i++) {
		for (size_t i = 0; i < maxFds + 1; i++) {
		files.emplace_back(android::os::ParcelFileDescriptor(mockFileDescriptor("a")));
		}