sandboxed-api/sandboxed_api/sandbox2/examples/network_proxy/networkproxy_sandbox.cc

142 lines
4.3 KiB
C++

// A demo sandbox for the network binary.
#include <arpa/inet.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <syscall.h>
#include <unistd.h>
#include <cstdlib>
#include <memory>
#include <string>
#include <utility>
#include <vector>
#include "absl/flags/flag.h"
#include "absl/flags/parse.h"
#include "absl/log/globals.h"
#include "absl/log/initialize.h"
#include "absl/log/log.h"
#include "absl/base/log_severity.h"
#include "absl/status/statusor.h"
#include "absl/strings/string_view.h"
#include "absl/time/time.h"
#include "sandboxed_api/config.h"
#include "sandboxed_api/sandbox2/comms.h"
#include "sandboxed_api/sandbox2/executor.h"
#include "sandboxed_api/sandbox2/network_proxy/testing.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/util/runfiles.h"
ABSL_FLAG(bool, connect_with_handler, true, "Connect using automatic mode.");
namespace {
constexpr char kSandboxeePath[] =
"sandbox2/examples/network_proxy/networkproxy_bin";
std::unique_ptr<sandbox2::Policy> GetPolicy(absl::string_view sandboxee_path) {
sandbox2::PolicyBuilder builder;
builder.AllowExit()
.AllowMmapWithoutExec()
.AllowRead()
.AllowWrite()
.AllowStat() // printf, puts
.AllowOpen()
.AllowSyscall(__NR_sendto) // send
.AllowSyscall(__NR_lseek)
.AllowSyscall(__NR_munmap)
.AllowSyscall(__NR_getpid)
.AllowSyscall(__NR_sigaltstack)
.AllowTcMalloc()
.AddLibrariesForBinary(sandboxee_path);
if (absl::GetFlag(FLAGS_connect_with_handler)) {
builder.AddNetworkProxyHandlerPolicy();
} else {
builder.AddNetworkProxyPolicy();
}
return builder.AllowIPv6("::1").BuildOrDie();
}
} // namespace
int main(int argc, char* argv[]) {
// This test is incompatible with sanitizers.
// The `SKIP_SANITIZERS_AND_COVERAGE` macro won't work for us here since we
// need to return something.
if constexpr (sapi::sanitizers::IsAny()) {
return EXIT_SUCCESS;
}
absl::SetStderrThreshold(absl::LogSeverityAtLeast::kInfo);
absl::ParseCommandLine(argc, argv);
absl::InitializeLog();
absl::StatusOr<std::unique_ptr<sandbox2::NetworkProxyTestServer>> server =
sandbox2::NetworkProxyTestServer::Start();
if (!server.ok()) {
LOG(ERROR) << server.status();
return EXIT_FAILURE;
}
// Note: In your own code, use sapi::GetDataDependencyFilePath() instead.
const std::string path =
sapi::internal::GetSapiDataDependencyFilePath(kSandboxeePath);
std::vector<std::string> args = {path};
if (!absl::GetFlag(FLAGS_connect_with_handler)) {
args.push_back("--noconnect_with_handler");
}
std::vector<std::string> envs = {};
auto executor = std::make_unique<sandbox2::Executor>(path, args, envs);
executor
// Sandboxing is enabled by the binary itself (i.e. the networkproxy_bin
// is capable of enabling sandboxing on its own).
->set_enable_sandbox_before_exec(false)
// Set cwd to / to get rids of warnings connected with file namespace.
.set_cwd("/");
executor
->limits()
// Kill sandboxed processes with a signal (SIGXFSZ) if it writes more than
// these many bytes to the file-system.
->set_rlimit_fsize(10000)
// The CPU time limit in seconds.
.set_rlimit_cpu(100)
.set_walltime_limit(absl::Seconds(100));
auto policy = GetPolicy(path);
sandbox2::Sandbox2 s2(std::move(executor), std::move(policy));
sandbox2::Comms* comms = s2.comms();
// Let the sandboxee run.
if (!s2.RunAsync()) {
auto result = s2.AwaitResult();
LOG(ERROR) << "RunAsync failed: " << result.ToString();
return 2;
}
// Send the port number via comms
if (!comms->SendInt32((*server)->port())) {
LOG(ERROR) << "sandboxee_comms->SendInt32() failed";
return 3;
}
auto result = s2.AwaitResult();
if (result.final_status() != sandbox2::Result::OK) {
LOG(ERROR) << "Sandbox error: " << result.ToString();
return 4; // e.g. sandbox violation, signal (sigsegv)
}
auto code = result.reason_code();
if (code) {
LOG(ERROR) << "Sandboxee exited with non-zero: " << code;
return 5; // e.g. normal child error
}
LOG(INFO) << "Sandboxee finished: " << result.ToString();
return EXIT_SUCCESS;
}