sandboxed-api/sandboxed_api/sandbox2/network_proxy/server.cc
Wiktor Garbacz 5f9698612e Better network proxy tests
Fix sending error on `connect` failure.

PiperOrigin-RevId: 562693682
Change-Id: I70c710a9001f22e172cbe4df328983bfa7188d3d
2023-09-05 00:57:27 -07:00

127 lines
3.4 KiB
C++

// 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/network_proxy/server.h"
#include <netinet/in.h>
#include <pthread.h>
#include <signal.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <atomic>
#include <cerrno>
#include <cstdint>
#include <memory>
#include <string>
#include <utility>
#include <vector>
#include "absl/log/log.h"
#include "absl/status/status.h"
#include "absl/status/statusor.h"
#include "sandboxed_api/sandbox2/comms.h"
#include "sandboxed_api/sandbox2/network_proxy/filtering.h"
#include "sandboxed_api/util/fileops.h"
namespace sandbox2 {
namespace file_util = ::sapi::file_util;
NetworkProxyServer::NetworkProxyServer(int fd, AllowedHosts* allowed_hosts,
pthread_t monitor_thread_id)
: violation_occurred_(false),
comms_(std::make_unique<Comms>(fd)),
fatal_error_(false),
monitor_thread_id_(monitor_thread_id),
allowed_hosts_(allowed_hosts) {}
void NetworkProxyServer::ProcessConnectRequest() {
std::vector<uint8_t> addr;
if (!comms_->RecvBytes(&addr)) {
fatal_error_ = true;
return;
}
const struct sockaddr* saddr = reinterpret_cast<const sockaddr*>(addr.data());
// Only IPv4 TCP and IPv6 TCP are supported.
if (!((addr.size() == sizeof(sockaddr_in) && saddr->sa_family == AF_INET) ||
(addr.size() == sizeof(sockaddr_in6) &&
saddr->sa_family == AF_INET6))) {
SendError(EINVAL);
return;
}
if (!allowed_hosts_->IsHostAllowed(saddr)) {
NotifyViolation(saddr);
return;
}
int new_socket = socket(saddr->sa_family, SOCK_STREAM, 0);
if (new_socket < 0) {
SendError(errno);
return;
}
file_util::fileops::FDCloser new_socket_closer(new_socket);
int result = connect(
new_socket, reinterpret_cast<const sockaddr*>(addr.data()), addr.size());
if (result < 0) {
SendError(errno);
return;
}
NotifySuccess();
if (!fatal_error_ && !comms_->SendFD(new_socket)) {
fatal_error_ = true;
return;
}
}
void NetworkProxyServer::Run() {
while (!fatal_error_ &&
!violation_occurred_.load(std::memory_order_relaxed)) {
ProcessConnectRequest();
}
LOG(INFO)
<< "Clean shutdown or error occurred, shutting down NetworkProxyServer";
}
void NetworkProxyServer::SendError(int saved_errno) {
if (!comms_->SendInt32(saved_errno)) {
fatal_error_ = true;
}
}
void NetworkProxyServer::NotifySuccess() {
if (!comms_->SendInt32(0)) {
fatal_error_ = true;
}
}
void NetworkProxyServer::NotifyViolation(const struct sockaddr* saddr) {
if (absl::StatusOr<std::string> result = AddrToString(saddr); result.ok()) {
violation_msg_ = std::move(result).value();
} else {
violation_msg_ = std::string(result.status().message());
}
violation_occurred_.store(true, std::memory_order_release);
pthread_kill(monitor_thread_id_, SIGCHLD);
}
} // namespace sandbox2