143 lines
4.3 KiB
C++
143 lines
4.3 KiB
C++
// Copyright 2019 Google LLC
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// https://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#include "sandboxed_api/sandbox2/network_proxy/client.h"
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#include <sys/socket.h>
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#include <syscall.h>
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#include <unistd.h>
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#include <cerrno>
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#include <cstdint>
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#include "absl/log/log.h"
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#include "absl/status/status.h"
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#include "absl/synchronization/mutex.h"
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#include "sandboxed_api/sandbox2/util/syscall_trap.h"
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#include "sandboxed_api/util/status_macros.h"
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namespace sandbox2 {
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int NetworkProxyClient::ConnectHandler(int sockfd, const struct sockaddr* addr,
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socklen_t addrlen) {
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absl::Status status = Connect(sockfd, addr, addrlen);
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if (status.ok()) {
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return 0;
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}
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LOG(ERROR) << "ConnectHandler() failed: " << status.message();
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return -1;
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}
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absl::Status NetworkProxyClient::Connect(int sockfd,
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const struct sockaddr* addr,
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socklen_t addrlen) {
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absl::MutexLock lock(&mutex_);
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// Check if socket is SOCK_STREAM
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int type;
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socklen_t type_size = sizeof(int);
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int result = getsockopt(sockfd, SOL_SOCKET, SO_TYPE, &type, &type_size);
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if (result == -1) {
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return absl::FailedPreconditionError("Invalid socket FD");
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}
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if (type_size != sizeof(int) || type != SOCK_STREAM) {
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errno = EINVAL;
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return absl::InvalidArgumentError(
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"Invalid socket, only SOCK_STREAM is allowed");
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}
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// Send sockaddr struct
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if (!comms_.SendBytes(reinterpret_cast<const uint8_t*>(addr), addrlen)) {
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errno = EIO;
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return absl::InternalError("Sending data to network proxy failed");
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}
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SAPI_RETURN_IF_ERROR(ReceiveRemoteResult());
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// Receive new socket
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int s;
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if (!comms_.RecvFD(&s)) {
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errno = EIO;
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return absl::InternalError("Receiving data from network proxy failed");
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}
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if (dup2(s, sockfd) == -1) {
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close(s);
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return absl::InternalError("Processing data from network proxy failed");
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}
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return absl::OkStatus();
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}
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absl::Status NetworkProxyClient::ReceiveRemoteResult() {
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int result;
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if (!comms_.RecvInt32(&result)) {
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errno = EIO;
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return absl::InternalError("Receiving data from the network proxy failed");
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}
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if (result != 0) {
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errno = result;
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return absl::ErrnoToStatus(errno, "Error in network proxy server");
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}
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return absl::OkStatus();
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}
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NetworkProxyClient* NetworkProxyHandler::network_proxy_client_ = nullptr;
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absl::Status NetworkProxyHandler::InstallNetworkProxyHandler(
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NetworkProxyClient* npc) {
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if (network_proxy_client_ != nullptr) {
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return absl::AlreadyExistsError(
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"Network proxy handler is already installed");
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}
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network_proxy_client_ = npc;
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if (!SyscallTrap::Install([](int nr, SyscallTrap::Args args, uintptr_t* rv) {
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return ProcessSeccompTrap(nr, args, rv);
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})) {
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return absl::InternalError("Could not install syscall trap");
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}
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return absl::OkStatus();
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}
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bool NetworkProxyHandler::ProcessSeccompTrap(int nr, SyscallTrap::Args args,
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uintptr_t* rv) {
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int sockfd;
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const struct sockaddr* addr;
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socklen_t addrlen;
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if (nr == __NR_connect) {
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sockfd = static_cast<int>(args[0]);
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addr = reinterpret_cast<const struct sockaddr*>(args[1]);
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addrlen = static_cast<socklen_t>(args[2]);
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#if defined(SAPI_PPC64_LE)
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} else if (nr == __NR_socketcall &&
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static_cast<int>(args[0]) == SYS_CONNECT) {
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auto* connect_args = reinterpret_cast<uint64_t*>(args[1]);
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sockfd = static_cast<int>(connect_args[0]);
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addr = reinterpret_cast<const struct sockaddr*>(connect_args[1]);
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addrlen = static_cast<socklen_t>(connect_args[2]);
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#endif
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} else {
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return false;
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}
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absl::Status result = network_proxy_client_->Connect(sockfd, addr, addrlen);
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if (result.ok()) {
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*rv = 0;
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} else {
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*rv = -errno;
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}
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return true;
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}
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} // namespace sandbox2
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