sandboxed-api/sandboxed_api/sapi_test.cc

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// Copyright 2019 Google LLC
//
// 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
//
// https://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.
#include <fcntl.h>
#include <memory>
#include <string>
#include <thread> // NOLINT(build/c++11)
#include "benchmark/benchmark.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "absl/status/status.h"
#include "absl/status/statusor.h"
#include "absl/time/clock.h"
#include "absl/time/time.h"
#include "sandboxed_api/examples/stringop/stringop-sapi.sapi.h"
#include "sandboxed_api/examples/stringop/stringop_params.pb.h"
#include "sandboxed_api/examples/sum/sum-sapi.sapi.h"
#include "sandboxed_api/sandbox.h"
#include "sandboxed_api/testing.h"
#include "sandboxed_api/transaction.h"
#include "sandboxed_api/util/status_matchers.h"
namespace sapi {
namespace {
using ::sapi::IsOk;
using ::sapi::StatusIs;
using ::testing::Eq;
using ::testing::Gt;
using ::testing::HasSubstr;
// Functions that will be used during the benchmarks:
// Function causing no load in the sandboxee.
absl::Status InvokeNop(Sandbox* sandbox) {
StringopApi api(sandbox);
return api.nop();
}
// Function that makes use of our special protobuf (de)-serialization code
// inside SAPI (including the back-synchronization of the structure).
absl::Status InvokeStringReversal(Sandbox* sandbox) {
StringopApi api(sandbox);
stringop::StringReverse proto;
proto.set_input("Hello");
absl::StatusOr<v::Proto<stringop::StringReverse>> pp(
v::Proto<stringop::StringReverse>::FromMessage(proto));
SAPI_RETURN_IF_ERROR(pp.status());
SAPI_ASSIGN_OR_RETURN(int return_code, api.pb_reverse_string(pp->PtrBoth()));
TRANSACTION_FAIL_IF_NOT(return_code != 0, "pb_reverse_string failed");
SAPI_ASSIGN_OR_RETURN(auto pb_result, pp->GetMessage());
TRANSACTION_FAIL_IF_NOT(pb_result.output() == "olleH", "Incorrect output");
return absl::OkStatus();
}
// Benchmark functions:
// Restart SAPI sandbox by letting the sandbox object go out of scope.
// Minimal case for measuring the minimum overhead of restarting the sandbox.
void BenchmarkSandboxRestartOverhead(benchmark::State& state) {
for (auto _ : state) {
BasicTransaction st(std::make_unique<StringopSandbox>());
// Invoke nop() to make sure that our sandbox is running.
EXPECT_THAT(st.Run(InvokeNop), IsOk());
}
}
BENCHMARK(BenchmarkSandboxRestartOverhead);
void BenchmarkSandboxRestartForkserverOverhead(benchmark::State& state) {
sapi::BasicTransaction st(std::make_unique<StringopSandbox>());
for (auto _ : state) {
EXPECT_THAT(st.Run(InvokeNop), IsOk());
EXPECT_THAT(st.sandbox()->Restart(true), IsOk());
}
}
BENCHMARK(BenchmarkSandboxRestartForkserverOverhead);
void BenchmarkSandboxRestartForkserverOverheadForced(benchmark::State& state) {
sapi::BasicTransaction st{std::make_unique<StringopSandbox>()};
for (auto _ : state) {
EXPECT_THAT(st.Run(InvokeNop), IsOk());
EXPECT_THAT(st.sandbox()->Restart(false), IsOk());
}
}
BENCHMARK(BenchmarkSandboxRestartForkserverOverheadForced);
// Reuse the sandbox. Used to measure the overhead of the call invocation.
void BenchmarkCallOverhead(benchmark::State& state) {
BasicTransaction st(std::make_unique<StringopSandbox>());
for (auto _ : state) {
EXPECT_THAT(st.Run(InvokeNop), IsOk());
}
}
BENCHMARK(BenchmarkCallOverhead);
// Make use of protobufs.
void BenchmarkProtobufHandling(benchmark::State& state) {
BasicTransaction st(std::make_unique<StringopSandbox>());
for (auto _ : state) {
EXPECT_THAT(st.Run(InvokeStringReversal), IsOk());
}
}
BENCHMARK(BenchmarkProtobufHandling);
// Measure overhead of synchronizing data.
void BenchmarkIntDataSynchronization(benchmark::State& state) {
auto sandbox = std::make_unique<StringopSandbox>();
ASSERT_THAT(sandbox->Init(), IsOk());
long current_val = 0; // NOLINT
v::Long long_var;
// Allocate remote memory.
ASSERT_THAT(sandbox->Allocate(&long_var, false), IsOk());
for (auto _ : state) {
// Write current_val to the process.
long_var.SetValue(current_val);
EXPECT_THAT(sandbox->TransferToSandboxee(&long_var), IsOk());
// Invalidate value to make sure that the next call
// is not simply a noop.
long_var.SetValue(-1);
// Read value back.
EXPECT_THAT(sandbox->TransferFromSandboxee(&long_var), IsOk());
EXPECT_THAT(long_var.GetValue(), Eq(current_val));
current_val++;
}
}
BENCHMARK(BenchmarkIntDataSynchronization);
// Test whether stack trace generation works.
TEST(SapiTest, HasStackTraces) {
SKIP_SANITIZERS_AND_COVERAGE;
auto sandbox = std::make_unique<StringopSandbox>();
ASSERT_THAT(sandbox->Init(), IsOk());
StringopApi api(sandbox.get());
EXPECT_THAT(api.violate(), StatusIs(absl::StatusCode::kUnavailable));
const auto& result = sandbox->AwaitResult();
EXPECT_THAT(
result.GetStackTrace(),
// Check that at least one expected function is present in the stack
// trace.
// Note: Typically, in optimized builds, on x86-64, only
// "ViolateIndirect()" will be present in the stack trace. On POWER, all
// stack frames are generated, but libunwind will be unable to track
// "ViolateIndirect()" on the stack and instead show its IP as zero.
AnyOf(HasSubstr("ViolateIndirect"), HasSubstr("violate")));
EXPECT_THAT(result.final_status(), Eq(sandbox2::Result::VIOLATION));
}
// Various tests:
// Leaks a file descriptor inside the sandboxee.
int LeakFileDescriptor(sapi::Sandbox* sandbox, const char* path) {
int raw_fd = open(path, O_RDONLY);
sapi::v::Fd fd(raw_fd); // Takes ownership of the raw fd.
EXPECT_THAT(sandbox->TransferToSandboxee(&fd), IsOk());
// We want to leak the remote FD. The local FD will still be closed.
fd.OwnRemoteFd(false);
return fd.GetRemoteFd();
}
// Make sure that restarting the sandboxee works (= fresh set of FDs).
TEST(SandboxTest, RestartSandboxFD) {
sapi::BasicTransaction st{std::make_unique<SumSandbox>()};
auto test_body = [](sapi::Sandbox* sandbox) -> absl::Status {
// Open some FDs and check their value.
int first_remote_fd = LeakFileDescriptor(sandbox, "/proc/self/exe");
EXPECT_THAT(LeakFileDescriptor(sandbox, "/proc/self/exe"),
Eq(first_remote_fd + 1));
SAPI_RETURN_IF_ERROR(sandbox->Restart(false));
// We should have a fresh sandbox now = FDs open previously should be
// closed now.
EXPECT_THAT(LeakFileDescriptor(sandbox, "/proc/self/exe"),
Eq(first_remote_fd));
return absl::OkStatus();
};
EXPECT_THAT(st.Run(test_body), IsOk());
}
TEST(SandboxTest, RestartTransactionSandboxFD) {
sapi::BasicTransaction st{std::make_unique<SumSandbox>()};
int fd_no = -1;
ASSERT_THAT(st.Run([&fd_no](sapi::Sandbox* sandbox) -> absl::Status {
fd_no = LeakFileDescriptor(sandbox, "/proc/self/exe");
return absl::OkStatus();
}),
IsOk());
EXPECT_THAT(st.Run([fd_no](sapi::Sandbox* sandbox) -> absl::Status {
EXPECT_THAT(LeakFileDescriptor(sandbox, "/proc/self/exe"), Gt(fd_no));
return absl::OkStatus();
}),
IsOk());
EXPECT_THAT(st.Restart(), IsOk());
EXPECT_THAT(st.Run([fd_no](sapi::Sandbox* sandbox) -> absl::Status {
EXPECT_THAT(LeakFileDescriptor(sandbox, "/proc/self/exe"), Eq(fd_no));
return absl::OkStatus();
}),
IsOk());
}
// Make sure we can recover from a dying sandbox.
TEST(SandboxTest, RestartSandboxAfterCrash) {
SumSandbox sandbox;
ASSERT_THAT(sandbox.Init(), IsOk());
SumApi api(&sandbox);
// Crash the sandbox.
EXPECT_THAT(api.crash(), StatusIs(absl::StatusCode::kUnavailable));
EXPECT_THAT(api.sum(1, 2).status(), StatusIs(absl::StatusCode::kUnavailable));
EXPECT_THAT(sandbox.AwaitResult().final_status(),
Eq(sandbox2::Result::SIGNALED));
// Restart the sandbox.
ASSERT_THAT(sandbox.Restart(false), IsOk());
// The sandbox should now be responsive again.
SAPI_ASSERT_OK_AND_ASSIGN(int result, api.sum(1, 2));
EXPECT_THAT(result, Eq(3));
}
TEST(SandboxTest, RestartSandboxAfterViolation) {
SumSandbox sandbox;
ASSERT_THAT(sandbox.Init(), IsOk());
SumApi api(&sandbox);
// Violate the sandbox policy.
EXPECT_THAT(api.violate(), StatusIs(absl::StatusCode::kUnavailable));
EXPECT_THAT(api.sum(1, 2).status(), StatusIs(absl::StatusCode::kUnavailable));
EXPECT_THAT(sandbox.AwaitResult().final_status(),
Eq(sandbox2::Result::VIOLATION));
// Restart the sandbox.
ASSERT_THAT(sandbox.Restart(false), IsOk());
// The sandbox should now be responsive again.
SAPI_ASSERT_OK_AND_ASSIGN(int result, api.sum(1, 2));
EXPECT_THAT(result, Eq(3));
}
TEST(SandboxTest, NoRaceInAwaitResult) {
StringopSandbox sandbox;
ASSERT_THAT(sandbox.Init(), IsOk());
StringopApi api(&sandbox);
EXPECT_THAT(api.violate(), StatusIs(absl::StatusCode::kUnavailable));
absl::SleepFor(absl::Milliseconds(200)); // Make sure we lose the race
const auto& result = sandbox.AwaitResult();
EXPECT_THAT(result.final_status(), Eq(sandbox2::Result::VIOLATION));
}
TEST(SandboxTest, NoRaceInConcurrentTerminate) {
SumSandbox sandbox;
ASSERT_THAT(sandbox.Init(), IsOk());
SumApi api(&sandbox);
std::thread th([&sandbox] {
// Sleep so that the call already starts
absl::SleepFor(absl::Seconds(1));
sandbox.Terminate(/*attempt_graceful_exit=*/false);
});
EXPECT_THAT(api.sleep_for_sec(10), StatusIs(absl::StatusCode::kUnavailable));
th.join();
const auto& result = sandbox.AwaitResult();
EXPECT_THAT(result.final_status(), Eq(sandbox2::Result::EXTERNAL_KILL));
}
} // namespace
} // namespace sapi