Merge "libbinder: remove gMaxFds from Parcel" (50219f1d) · Commits · e / os / android_frameworks_native

libs/binder/Parcel.cpp

+4 −15

Original line number	Diff line number	Diff line
		@@ -87,7 +87,8 @@ static_assert(sizeof(Parcel) == 60);
		static std::atomic<size_t> gParcelGlobalAllocCount;
		static std::atomic<size_t> gParcelGlobalAllocSize;

		static size_t gMaxFds = 0;
		// Maximum number of file descriptors per Parcel.
		constexpr size_t kMaxFds = 1024;

		// Maximum size of a blob to transfer in-place.
		static const size_t BLOB_INPLACE_LIMIT = 16 * 1024;
		@@ -1416,7 +1417,7 @@ status_t Parcel::write(const FlattenableHelperInterface& val)
		const size_t len = val.getFlattenedSize();
		const size_t fd_count = val.getFdCount();

		if ((len > INT32_MAX) \|\| (fd_count >= gMaxFds)) {
		if ((len > INT32_MAX) \|\| (fd_count > kMaxFds)) {
		// don't accept size_t values which may have come from an
		// inadvertent conversion from a negative int.
		return BAD_VALUE;
		@@ -2158,7 +2159,7 @@ status_t Parcel::read(FlattenableHelperInterface& val) const
		const size_t len = this->readInt32();
		const size_t fd_count = this->readInt32();

		if ((len > INT32_MAX) \|\| (fd_count >= gMaxFds)) {
		if ((len > INT32_MAX) \|\| (fd_count > kMaxFds)) {
		// don't accept size_t values which may have come from an
		// inadvertent conversion from a negative int.
		return BAD_VALUE;
		@@ -2747,18 +2748,6 @@ void Parcel::initState()
		mAllowFds = true;
		mDeallocZero = false;
		mOwner = nullptr;

		// racing multiple init leads only to multiple identical write
		if (gMaxFds == 0) {
		struct rlimit result;
		if (!getrlimit(RLIMIT_NOFILE, &result)) {
		gMaxFds = (size_t)result.rlim_cur;
		//ALOGI("parcel fd limit set to %zu", gMaxFds);
		} else {
		ALOGW("Unable to getrlimit: %s", strerror(errno));
		gMaxFds = 1024;
		}
		}
		}

		void Parcel::scanForFds() const {

libs/binder/tests/binderLibTest.cpp

+48 −0

Original line number	Diff line number	Diff line
		@@ -30,6 +30,7 @@
		#include <android-base/properties.h>
		#include <android-base/result-gmock.h>
		#include <android-base/result.h>
		#include <android-base/scopeguard.h>
		#include <android-base/strings.h>
		#include <android-base/unique_fd.h>
		#include <binder/Binder.h>
		@@ -1232,6 +1233,53 @@ TEST_F(BinderLibTest, GotSid) {
		EXPECT_THAT(server->transact(BINDER_LIB_TEST_CAN_GET_SID, data, nullptr), StatusEq(OK));
		}

		struct TooManyFdsFlattenable : Flattenable<TooManyFdsFlattenable> {
		TooManyFdsFlattenable(size_t fdCount) : mFdCount(fdCount) {}

		// Flattenable protocol
		size_t getFlattenedSize() const {
		// Return a valid non-zero size here so we don't get an unintended
		// BAD_VALUE from Parcel::write
		return 16;
		}
		size_t getFdCount() const { return mFdCount; }
		status_t flatten(void & /buffer/, size_t & /size/, int &fds, size_t &count) const {
		for (size_t i = 0; i < count; i++) {
		fds[i] = STDIN_FILENO;
		}
		return NO_ERROR;
		}
		status_t unflatten(void const & /buffer/, size_t & /size/, int const & /fds/,
		size_t & /count/) {
		/* This doesn't get called */
		return NO_ERROR;
		}

		size_t mFdCount;
		};

		TEST_F(BinderLibTest, TooManyFdsFlattenable) {
		rlimit origNofile;
		int ret = getrlimit(RLIMIT_NOFILE, &origNofile);
		ASSERT_EQ(0, ret);

		// Restore the original file limits when the test finishes
		base::ScopeGuard guardUnguard([&]() { setrlimit(RLIMIT_NOFILE, &origNofile); });

		rlimit testNofile = {1024, 1024};
		ret = setrlimit(RLIMIT_NOFILE, &testNofile);
		ASSERT_EQ(0, ret);

		Parcel parcel;
		// Try to write more file descriptors than supported by the OS
		TooManyFdsFlattenable tooManyFds1(1024);
		EXPECT_THAT(parcel.write(tooManyFds1), StatusEq(-EMFILE));

		// Try to write more file descriptors than the internal limit
		TooManyFdsFlattenable tooManyFds2(1025);
		EXPECT_THAT(parcel.write(tooManyFds2), StatusEq(BAD_VALUE));
		}

		TEST(ServiceNotifications, Unregister) {
		auto sm = defaultServiceManager();
		using LocalRegistrationCallback = IServiceManager::LocalRegistrationCallback;