sandboxed-api/sandboxed_api/sandbox2/namespace_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 "sandboxed_api/sandbox2/namespace.h"
#include <unistd.h>
#include <cstdint>
#include <cstdlib>
#include <initializer_list>
#include <memory>
#include <string>
#include <utility>
#include <vector>
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "absl/log/check.h"
#include "absl/status/statusor.h"
#include "absl/strings/str_cat.h"
#include "absl/strings/string_view.h"
#include "sandboxed_api/sandbox2/allow_all_syscalls.h"
#include "sandboxed_api/sandbox2/executor.h"
#include "sandboxed_api/sandbox2/policy.h"
#include "sandboxed_api/sandbox2/policybuilder.h"
#include "sandboxed_api/sandbox2/result.h"
#include "sandboxed_api/sandbox2/sandbox2.h"
#include "sandboxed_api/testing.h"
#include "sandboxed_api/util/fileops.h"
#include "sandboxed_api/util/status_matchers.h"
#include "sandboxed_api/util/temp_file.h"
namespace sandbox2 {
namespace {
namespace file_util = ::sapi::file_util;
using ::sapi::CreateDefaultPermissiveTestPolicy;
using ::sapi::CreateNamedTempFile;
using ::sapi::GetTestSourcePath;
using ::sapi::GetTestTempPath;
using ::testing::AllOf;
using ::testing::AnyOfArray;
using ::testing::Contains;
using ::testing::ElementsAre;
using ::testing::Eq;
using ::testing::Gt;
using ::testing::HasSubstr;
using ::testing::IsEmpty;
using ::testing::Matcher;
using ::testing::Ne;
using ::testing::SizeIs;
using ::testing::StartsWith;
using ::testing::StrEq; // sapi::google3-only(broken matchers)
std::string GetTestcaseBinPath(absl::string_view bin_name) {
return GetTestSourcePath(absl::StrCat("sandbox2/testcases/", bin_name));
}
std::vector<std::string> RunSandboxeeWithArgsAndPolicy(
const std::string& bin_path, std::initializer_list<std::string> args,
std::unique_ptr<Policy> policy = nullptr) {
if (!policy) {
policy = CreateDefaultPermissiveTestPolicy(bin_path).BuildOrDie();
}
Sandbox2 sandbox(std::make_unique<Executor>(bin_path, args),
std::move(policy));
CHECK(sandbox.RunAsync());
Comms* comms = sandbox.comms();
uint64_t num;
std::vector<std::string> entries;
if (comms->RecvUint64(&num)) {
entries.reserve(num);
for (int i = 0; i < num; ++i) {
std::string entry;
CHECK(comms->RecvString(&entry));
entries.push_back(std::move(entry));
}
}
Result result = sandbox.AwaitResult();
EXPECT_THAT(result.final_status(), Eq(Result::OK));
EXPECT_THAT(result.reason_code(), Eq(0));
return entries;
}
TEST(NamespaceTest, FileNamespaceWorks) {
// Mount /binary_path RO and check that it exists and is readable.
// /etc/passwd should not exist.
const std::string path = GetTestcaseBinPath("namespace");
SAPI_ASSERT_OK_AND_ASSIGN(auto policy, CreateDefaultPermissiveTestPolicy(path)
.AddFileAt(path, "/binary_path")
.TryBuild());
std::vector<std::string> result = RunSandboxeeWithArgsAndPolicy(
path, {path, "0", "/binary_path", "/etc/passwd"}, std::move(policy));
EXPECT_THAT(result, ElementsAre("/binary_path"));
}
TEST(NamespaceTest, ReadOnlyIsRespected) {
// Mount temporary file as RO and check that it actually is RO.
auto [name, fd] = CreateNamedTempFile(GetTestTempPath("temp_file")).value();
file_util::fileops::FDCloser temp_closer(fd);
const std::string path = GetTestcaseBinPath("namespace");
{
SAPI_ASSERT_OK_AND_ASSIGN(auto policy,
CreateDefaultPermissiveTestPolicy(path)
.AddFileAt(name, "/temp_file")
.TryBuild());
// Check that it is readable
std::vector<std::string> result = RunSandboxeeWithArgsAndPolicy(
path, {path, "0", "/temp_file"}, std::move(policy));
EXPECT_THAT(result, ElementsAre("/temp_file"));
}
{
SAPI_ASSERT_OK_AND_ASSIGN(auto policy,
CreateDefaultPermissiveTestPolicy(path)
.AddFileAt(name, "/temp_file")
.TryBuild());
// Now check that it is not writeable
std::vector<std::string> result = RunSandboxeeWithArgsAndPolicy(
path, {path, "1", "/temp_file"}, std::move(policy));
EXPECT_THAT(result, IsEmpty());
}
}
TEST(NamespaceTest, UserNamespaceWorks) {
const std::string path = GetTestcaseBinPath("namespace");
// Check that getpid() returns 2 (which is the case inside pid NS).
{
std::vector<std::string> result =
RunSandboxeeWithArgsAndPolicy(path, {path, "2"});
EXPECT_THAT(result, ElementsAre("2"));
}
// Validate that getpid() does not return 2 when outside of a pid NS.
{
std::vector<std::string> result = RunSandboxeeWithArgsAndPolicy(
path, {path, "2"},
PolicyBuilder()
.DisableNamespaces()
.DefaultAction(AllowAllSyscalls()) // Do not restrict syscalls
.BuildOrDie());
EXPECT_THAT(result, ElementsAre(Ne("2")));
}
}
TEST(NamespaceTest, UserNamespaceIDMapWritten) {
// Check that the idmap is initialized before the sandbox application is
// started.
const std::string path = GetTestcaseBinPath("namespace");
{
std::vector<std::string> result =
RunSandboxeeWithArgsAndPolicy(path, {path, "3", "1000", "1000"});
EXPECT_THAT(result, ElementsAre("1000", "1000"));
}
// Check that the uid/gid is the same when not using namespaces.
{
std::vector<std::string> result = RunSandboxeeWithArgsAndPolicy(
path, {path, "3"},
PolicyBuilder()
.DisableNamespaces()
.DefaultAction(AllowAllSyscalls()) // Do not restrict syscalls
.BuildOrDie());
EXPECT_THAT(result,
ElementsAre(absl::StrCat(getuid()), absl::StrCat(getgid())));
}
}
TEST(NamespaceTest, RootReadOnly) {
// Mount rw tmpfs at /tmp and check it is RW.
// Check also that / is RO.
const std::string path = GetTestcaseBinPath("namespace");
SAPI_ASSERT_OK_AND_ASSIGN(
auto policy, CreateDefaultPermissiveTestPolicy(path)
.AddTmpfs("/tmp", /*size=*/4ULL << 20 /* 4 MiB */)
.TryBuild());
std::vector<std::string> result = RunSandboxeeWithArgsAndPolicy(
path, {path, "4", "/tmp/testfile", "/testfile"}, std::move(policy));
EXPECT_THAT(result, ElementsAre("/tmp/testfile"));
}
TEST(NamespaceTest, RootWritable) {
// Mount root rw and check it
const std::string path = GetTestcaseBinPath("namespace");
SAPI_ASSERT_OK_AND_ASSIGN(
auto policy,
CreateDefaultPermissiveTestPolicy(path).SetRootWritable().TryBuild());
std::vector<std::string> result = RunSandboxeeWithArgsAndPolicy(
path, {path, "4", "/testfile"}, std::move(policy));
EXPECT_THAT(result, ElementsAre("/testfile"));
}
TEST(NamespaceTest, HostnameNone) {
const std::string path = GetTestcaseBinPath("namespace");
std::vector<std::string> result = RunSandboxeeWithArgsAndPolicy(
path, {path, "7"},
PolicyBuilder()
.DisableNamespaces()
.DefaultAction(AllowAllSyscalls()) // Do not restrict syscalls
.BuildOrDie());
EXPECT_THAT(result, ElementsAre(Ne("sandbox2")));
}
TEST(NamespaceTest, HostnameDefault) {
const std::string path = GetTestcaseBinPath("namespace");
std::vector<std::string> result =
RunSandboxeeWithArgsAndPolicy(path, {path, "7"});
EXPECT_THAT(result, ElementsAre("sandbox2"));
}
TEST(NamespaceTest, HostnameConfigured) {
const std::string path = GetTestcaseBinPath("namespace");
SAPI_ASSERT_OK_AND_ASSIGN(auto policy, CreateDefaultPermissiveTestPolicy(path)
.SetHostname("configured")
.TryBuild());
std::vector<std::string> result =
RunSandboxeeWithArgsAndPolicy(path, {path, "7"}, std::move(policy));
EXPECT_THAT(result, ElementsAre("configured"));
}
TEST(NamespaceTest, TestInterfacesNoNetwork) {
const std::string path = GetTestcaseBinPath("namespace");
std::vector<std::string> result =
RunSandboxeeWithArgsAndPolicy(path, {path, "5"});
// Only loopback network interface 'lo'.
EXPECT_THAT(result, ElementsAre("lo"));
}
TEST(NamespaceTest, TestInterfacesWithNetwork) {
const std::string path = GetTestcaseBinPath("namespace");
SAPI_ASSERT_OK_AND_ASSIGN(auto policy, CreateDefaultPermissiveTestPolicy(path)
.AllowUnrestrictedNetworking()
.TryBuild());
std::vector<std::string> result =
RunSandboxeeWithArgsAndPolicy(path, {path, "5"}, std::move(policy));
// Loopback network interface 'lo' and more.
EXPECT_THAT(result, Contains("lo"));
EXPECT_THAT(result, SizeIs(Gt(1)));
}
TEST(NamespaceTest, TestFiles) {
SKIP_ANDROID;
const std::string path = GetTestcaseBinPath("namespace");
std::vector<std::string> result =
RunSandboxeeWithArgsAndPolicy(path, {path, "6", "/"});
std::vector<Matcher<std::string>> lib_paths = {
StartsWith("/lib/"), // Often a symlink -> /usr/lib
StartsWith("/usr/lib/"),
StartsWith("/lib64/"), // Often a symlink -> /usr/lib64
StartsWith("/usr/lib64/")};
auto correct_lib_path_matcher =
AllOf(HasSubstr(".so"), AnyOfArray(lib_paths));
std::vector<Matcher<std::string>> matchers = {
correct_lib_path_matcher,
// Conditionally mapped if Tomoyo is active
StrEq(absl::StrCat("/dev/fd/", Comms::kSandbox2TargetExecFD)),
// System ldconfig cache
StrEq("/etc/ld.so.cache"),
// GRTE ldconfig cache
StrEq("/usr/grte/v4/etc/ld.so.cache"),
StrEq("/usr/grte/v5/etc/ld.so.cache"),
// procfs and sysfs
StartsWith("/proc"), StartsWith("/sys")};
// Coverage DIR
char* coverage_dir = getenv("COVERAGE_DIR");
if (coverage_dir != nullptr) {
matchers.push_back(StartsWith(coverage_dir));
}
for (const auto& file : result) {
EXPECT_THAT(file, AnyOfArray(matchers));
}
}
} // namespace
} // namespace sandbox2