common/frontend/socket_vsock_proxy/main.cpp - device/google/cuttlefish - Git at Google

 /*
  * Copyright (C) 2018 The Android Open Source Project
  *
  * 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
  *
  *      http://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 <set>
 #include <thread>
 #include <android-base/logging.h>
 #include <gflags/gflags.h>

 #include "common/libs/fs/shared_fd.h"
 #include "host/commands/kernel_log_monitor/utils.h"

 #ifdef CUTTLEFISH_HOST
 #include "host/libs/config/logging.h"
 #endif // CUTTLEFISH_HOST

 constexpr std::size_t kMaxPacketSize = 8192;

 DEFINE_string(server, "",
               "The type of server to host, `vsock` or `tcp`. When hosting a server "
               "of one type, the proxy will take inbound connections of this type and "
               "make outbound connections of the other type.");
 DEFINE_uint32(tcp_port, 0, "TCP port");
 DEFINE_uint32(vsock_port, 0, "vsock port");
 DEFINE_uint32(vsock_cid, 0, "Vsock cid to initiate connections to");
 DEFINE_int32(adbd_events_fd, -1, "A file descriptor. If set it will wait for "
                                  "AdbdStarted boot event from the kernel log "
                                  "monitor before creating a tcp-vsock tunnel."
                                  "This option is used by --server=tcp only "
                                  "when socket_vsock_proxy runs as a host service");
 DEFINE_int32(
     server_fd, -1,
     "A file descriptor. If set the passed file descriptor will be used as the "
     "server and the corresponding port flag will be ignored");

 namespace {
 // Sends packets, Shutdown(SHUT_WR) on destruction
 class SocketSender {
  public:
   explicit SocketSender(cuttlefish::SharedFD socket) : socket_{socket} {}

   SocketSender(SocketSender&&) = default;
   SocketSender& operator=(SocketSender&&) = default;

   SocketSender(const SocketSender&&) = delete;
   SocketSender& operator=(const SocketSender&) = delete;

   ~SocketSender() {
     if (socket_.operator->()) {  // check that socket_ was not moved-from
       socket_->Shutdown(SHUT_WR);
     }
   }

   ssize_t SendAll(const char* packet, ssize_t length) {
     ssize_t written{};
     while (written < length) {
       if (!socket_->IsOpen()) {
         return -1;
       }
       auto just_written =
           socket_->Send(packet + written,
                         length - written, MSG_NOSIGNAL);
       if (just_written <= 0) {
         LOG(WARNING) << "Couldn't write to client: "
                      << strerror(socket_->GetErrno());
         return just_written;
       }
       written += just_written;
     }
     return written;
   }

  private:
   cuttlefish::SharedFD socket_;
 };

 class SocketReceiver {
  public:
   explicit SocketReceiver(cuttlefish::SharedFD socket) : socket_{socket} {}

   SocketReceiver(SocketReceiver&&) = default;
   SocketReceiver& operator=(SocketReceiver&&) = default;

   SocketReceiver(const SocketReceiver&&) = delete;
   SocketReceiver& operator=(const SocketReceiver&) = delete;

   // return value will be 0 if Read returns 0 or error
   ssize_t Recv(char* packet, ssize_t length) {
     auto size = socket_->Read(packet, length);
     if (size < 0) {
       size = 0;
     }

     return size;
   }

  private:
   cuttlefish::SharedFD socket_;
 };

 void SocketToVsock(SocketReceiver socket_receiver,
                    SocketSender vsock_sender) {
   char packet[kMaxPacketSize] = {};

   while (true) {
     ssize_t length = socket_receiver.Recv(packet, kMaxPacketSize);
     if (length == 0 || vsock_sender.SendAll(packet, length) < 0) {
       break;
     }
   }
   LOG(DEBUG) << "Socket to vsock exiting";
 }

 void VsockToSocket(SocketSender socket_sender,
                    SocketReceiver vsock_receiver) {
   char packet[kMaxPacketSize] = {};

   while (true) {
     ssize_t length = vsock_receiver.Recv(packet, kMaxPacketSize);
     if (length == 0) {
       break;
     }
     if (socket_sender.SendAll(packet, length) < 0) {
       break;
     }
   }
   LOG(DEBUG) << "Vsock to socket exiting";
 }

 // One thread for reading from shm and writing into a socket.
 // One thread for reading from a socket and writing into shm.
 void HandleConnection(cuttlefish::SharedFD vsock,
                       cuttlefish::SharedFD socket) {
   auto socket_to_vsock =
       std::thread(SocketToVsock, SocketReceiver{socket}, SocketSender{vsock});
   VsockToSocket(SocketSender{socket}, SocketReceiver{vsock});
   socket_to_vsock.join();
 }

 void WaitForAdbdToBeStarted(int events_fd) {
   auto evt_shared_fd = cuttlefish::SharedFD::Dup(events_fd);
   close(events_fd);
   while (evt_shared_fd->IsOpen()) {
     std::optional<monitor::ReadEventResult> read_result =
         monitor::ReadEvent(evt_shared_fd);
     if (!read_result) {
       LOG(ERROR) << "Failed to read a complete kernel log adb event.";
       // The file descriptor can't be trusted anymore, stop waiting and try to
       // connect
       return;
     }

     if (read_result->event == monitor::Event::AdbdStarted) {
       LOG(DEBUG) << "Adbd has started in the guest, connecting adb";
       return;
     }
   }
 }

 // intented to run as cuttlefish host service
 [[noreturn]] void TcpServer() {
   LOG(DEBUG) << "starting TCP server on " << FLAGS_tcp_port
              << " for vsock port " << FLAGS_vsock_port;
   cuttlefish::SharedFD server;
   if (FLAGS_server_fd < 0) {
     server =
         cuttlefish::SharedFD::SocketLocalServer(FLAGS_tcp_port, SOCK_STREAM);
   } else {
     server = cuttlefish::SharedFD::Dup(FLAGS_server_fd);
     close(FLAGS_server_fd);
   }
   CHECK(server->IsOpen()) << "Could not start server on " << FLAGS_tcp_port;
   LOG(DEBUG) << "Accepting client connections";
   int last_failure_reason = 0;
   while (true) {
     auto client_socket = cuttlefish::SharedFD::Accept(*server);
     CHECK(client_socket->IsOpen()) << "error creating client socket";
     cuttlefish::SharedFD vsock_socket = cuttlefish::SharedFD::VsockClient(
         FLAGS_vsock_cid, FLAGS_vsock_port, SOCK_STREAM);
     if (vsock_socket->IsOpen()) {
       last_failure_reason = 0;
       LOG(DEBUG) << "Connected to vsock:" << FLAGS_vsock_cid << ":"
                  << FLAGS_vsock_port;
     } else {
       // Don't log if the previous connection failed with the same error
       if (last_failure_reason != vsock_socket->GetErrno()) {
         last_failure_reason = vsock_socket->GetErrno();
         LOG(ERROR) << "Unable to connect to vsock server: "
                    << vsock_socket->StrError();
       }
       continue;
     }
     auto thread = std::thread(HandleConnection, std::move(vsock_socket),
                               std::move(client_socket));
     thread.detach();
   }
 }

 cuttlefish::SharedFD OpenSocketConnection() {
   while (true) {
     auto sock = cuttlefish::SharedFD::SocketLocalClient(FLAGS_tcp_port, SOCK_STREAM);
     if (sock->IsOpen()) {
       return sock;
     }
     LOG(WARNING) << "could not connect on port " << FLAGS_tcp_port
                  << ". sleeping for 1 second";
     sleep(1);
   }
 }

 bool socketErrorIsRecoverable(int error) {
   std::set<int> unrecoverable{EACCES, EAFNOSUPPORT, EINVAL, EPROTONOSUPPORT};
   return unrecoverable.find(error) == unrecoverable.end();
 }

 [[noreturn]] static void SleepForever() {
   while (true) {
     sleep(std::numeric_limits<unsigned int>::max());
   }
 }

 // intended to run inside Android guest
 [[noreturn]] void VsockServer() {
   LOG(DEBUG) << "Starting vsock server on " << FLAGS_vsock_port;
   cuttlefish::SharedFD vsock;
   if (FLAGS_server_fd < 0) {
     do {
       vsock = cuttlefish::SharedFD::VsockServer(FLAGS_vsock_port, SOCK_STREAM);
       if (!vsock->IsOpen() && !socketErrorIsRecoverable(vsock->GetErrno())) {
         LOG(ERROR) << "Could not open vsock socket: " << vsock->StrError();
         SleepForever();
       }
     } while (!vsock->IsOpen());
   } else {
     vsock = cuttlefish::SharedFD::Dup(FLAGS_server_fd);
     close(FLAGS_server_fd);
   }
   CHECK(vsock->IsOpen()) << "Could not start server on " << FLAGS_vsock_port;
   while (true) {
     LOG(DEBUG) << "waiting for vsock connection";
     auto vsock_client = cuttlefish::SharedFD::Accept(*vsock);
     CHECK(vsock_client->IsOpen()) << "error creating vsock socket";
     LOG(DEBUG) << "vsock socket accepted";
     auto client = OpenSocketConnection();
     CHECK(client->IsOpen()) << "error connecting to guest client";
     auto thread = std::thread(HandleConnection, std::move(vsock_client),
                               std::move(client));
     thread.detach();
   }
 }

 }  // namespace

 int main(int argc, char* argv[]) {
 #ifdef CUTTLEFISH_HOST
   cuttlefish::DefaultSubprocessLogging(argv);
 #else
   ::android::base::InitLogging(argv, android::base::LogdLogger());
 #endif
   google::ParseCommandLineFlags(&argc, &argv, true);

   CHECK((FLAGS_server == "tcp" && FLAGS_server_fd >= 0) || FLAGS_tcp_port != 0)
       << "Must specify -tcp_port or -server_fd (with -server=tcp) flag";
   CHECK((FLAGS_server == "vsock" && FLAGS_server_fd >= 0) ||
         FLAGS_vsock_port != 0)
       << "Must specify -vsock_port or -server_fd (with -server=vsock) flag";

   if (FLAGS_adbd_events_fd >= 0) {
     LOG(DEBUG) << "Wating AdbdStarted boot event from the kernel log";
     WaitForAdbdToBeStarted(FLAGS_adbd_events_fd);
   }

   if (FLAGS_server == "tcp") {
     CHECK(FLAGS_vsock_cid != 0) << "Must specify -vsock_cid flag";
     TcpServer();
   } else if (FLAGS_server == "vsock") {
     VsockServer();
   } else {
     LOG(FATAL) << "Unknown server type: " << FLAGS_server;
   }
 }
	/*
	* Copyright (C) 2018 The Android Open Source Project
	*
	* 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
	*
	* http://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 <set>
	#include <thread>
	#include <android-base/logging.h>
	#include <gflags/gflags.h>

	#include "common/libs/fs/shared_fd.h"
	#include "host/commands/kernel_log_monitor/utils.h"

	#ifdef CUTTLEFISH_HOST
	#include "host/libs/config/logging.h"
	#endif // CUTTLEFISH_HOST

	constexpr std::size_t kMaxPacketSize = 8192;

	DEFINE_string(server, "",
	"The type of server to host, `vsock` or `tcp`. When hosting a server "
	"of one type, the proxy will take inbound connections of this type and "
	"make outbound connections of the other type.");
	DEFINE_uint32(tcp_port, 0, "TCP port");
	DEFINE_uint32(vsock_port, 0, "vsock port");
	DEFINE_uint32(vsock_cid, 0, "Vsock cid to initiate connections to");
	DEFINE_int32(adbd_events_fd, -1, "A file descriptor. If set it will wait for "
	"AdbdStarted boot event from the kernel log "
	"monitor before creating a tcp-vsock tunnel."
	"This option is used by --server=tcp only "
	"when socket_vsock_proxy runs as a host service");
	DEFINE_int32(
	server_fd, -1,
	"A file descriptor. If set the passed file descriptor will be used as the "
	"server and the corresponding port flag will be ignored");

	namespace {
	// Sends packets, Shutdown(SHUT_WR) on destruction
	class SocketSender {
	public:
	explicit SocketSender(cuttlefish::SharedFD socket) : socket_{socket} {}

	SocketSender(SocketSender&&) = default;
	SocketSender& operator=(SocketSender&&) = default;

	SocketSender(const SocketSender&&) = delete;
	SocketSender& operator=(const SocketSender&) = delete;

	~SocketSender() {
	if (socket_.operator->()) { // check that socket_ was not moved-from
	socket_->Shutdown(SHUT_WR);
	}
	}

	ssize_t SendAll(const char* packet, ssize_t length) {
	ssize_t written{};
	while (written < length) {
	if (!socket_->IsOpen()) {
	return -1;
	}
	auto just_written =
	socket_->Send(packet + written,
	length - written, MSG_NOSIGNAL);
	if (just_written <= 0) {
	LOG(WARNING) << "Couldn't write to client: "
	<< strerror(socket_->GetErrno());
	return just_written;
	}
	written += just_written;
	}
	return written;
	}

	private:
	cuttlefish::SharedFD socket_;
	};

	class SocketReceiver {
	public:
	explicit SocketReceiver(cuttlefish::SharedFD socket) : socket_{socket} {}

	SocketReceiver(SocketReceiver&&) = default;
	SocketReceiver& operator=(SocketReceiver&&) = default;

	SocketReceiver(const SocketReceiver&&) = delete;
	SocketReceiver& operator=(const SocketReceiver&) = delete;

	// return value will be 0 if Read returns 0 or error
	ssize_t Recv(char* packet, ssize_t length) {
	auto size = socket_->Read(packet, length);
	if (size < 0) {
	size = 0;
	}

	return size;
	}

	private:
	cuttlefish::SharedFD socket_;
	};

	void SocketToVsock(SocketReceiver socket_receiver,
	SocketSender vsock_sender) {
	char packet[kMaxPacketSize] = {};

	while (true) {
	ssize_t length = socket_receiver.Recv(packet, kMaxPacketSize);
	if (length == 0 \|\| vsock_sender.SendAll(packet, length) < 0) {
	break;
	}
	}
	LOG(DEBUG) << "Socket to vsock exiting";
	}

	void VsockToSocket(SocketSender socket_sender,
	SocketReceiver vsock_receiver) {
	char packet[kMaxPacketSize] = {};

	while (true) {
	ssize_t length = vsock_receiver.Recv(packet, kMaxPacketSize);
	if (length == 0) {
	break;
	}
	if (socket_sender.SendAll(packet, length) < 0) {
	break;
	}
	}
	LOG(DEBUG) << "Vsock to socket exiting";
	}

	// One thread for reading from shm and writing into a socket.
	// One thread for reading from a socket and writing into shm.
	void HandleConnection(cuttlefish::SharedFD vsock,
	cuttlefish::SharedFD socket) {
	auto socket_to_vsock =
	std::thread(SocketToVsock, SocketReceiver{socket}, SocketSender{vsock});
	VsockToSocket(SocketSender{socket}, SocketReceiver{vsock});
	socket_to_vsock.join();
	}

	void WaitForAdbdToBeStarted(int events_fd) {
	auto evt_shared_fd = cuttlefish::SharedFD::Dup(events_fd);
	close(events_fd);
	while (evt_shared_fd->IsOpen()) {
	std::optional<monitor::ReadEventResult> read_result =
	monitor::ReadEvent(evt_shared_fd);
	if (!read_result) {
	LOG(ERROR) << "Failed to read a complete kernel log adb event.";
	// The file descriptor can't be trusted anymore, stop waiting and try to
	// connect
	return;
	}

	if (read_result->event == monitor::Event::AdbdStarted) {
	LOG(DEBUG) << "Adbd has started in the guest, connecting adb";
	return;
	}
	}
	}

	// intented to run as cuttlefish host service
	[[noreturn]] void TcpServer() {
	LOG(DEBUG) << "starting TCP server on " << FLAGS_tcp_port
	<< " for vsock port " << FLAGS_vsock_port;
	cuttlefish::SharedFD server;
	if (FLAGS_server_fd < 0) {
	server =
	cuttlefish::SharedFD::SocketLocalServer(FLAGS_tcp_port, SOCK_STREAM);
	} else {
	server = cuttlefish::SharedFD::Dup(FLAGS_server_fd);
	close(FLAGS_server_fd);
	}
	CHECK(server->IsOpen()) << "Could not start server on " << FLAGS_tcp_port;
	LOG(DEBUG) << "Accepting client connections";
	int last_failure_reason = 0;
	while (true) {
	auto client_socket = cuttlefish::SharedFD::Accept(*server);
	CHECK(client_socket->IsOpen()) << "error creating client socket";
	cuttlefish::SharedFD vsock_socket = cuttlefish::SharedFD::VsockClient(
	FLAGS_vsock_cid, FLAGS_vsock_port, SOCK_STREAM);
	if (vsock_socket->IsOpen()) {
	last_failure_reason = 0;
	LOG(DEBUG) << "Connected to vsock:" << FLAGS_vsock_cid << ":"
	<< FLAGS_vsock_port;
	} else {
	// Don't log if the previous connection failed with the same error
	if (last_failure_reason != vsock_socket->GetErrno()) {
	last_failure_reason = vsock_socket->GetErrno();
	LOG(ERROR) << "Unable to connect to vsock server: "
	<< vsock_socket->StrError();
	}
	continue;
	}
	auto thread = std::thread(HandleConnection, std::move(vsock_socket),
	std::move(client_socket));
	thread.detach();
	}
	}

	cuttlefish::SharedFD OpenSocketConnection() {
	while (true) {
	auto sock = cuttlefish::SharedFD::SocketLocalClient(FLAGS_tcp_port, SOCK_STREAM);
	if (sock->IsOpen()) {
	return sock;
	}
	LOG(WARNING) << "could not connect on port " << FLAGS_tcp_port
	<< ". sleeping for 1 second";
	sleep(1);
	}
	}

	bool socketErrorIsRecoverable(int error) {
	std::set<int> unrecoverable{EACCES, EAFNOSUPPORT, EINVAL, EPROTONOSUPPORT};
	return unrecoverable.find(error) == unrecoverable.end();
	}

	[[noreturn]] static void SleepForever() {
	while (true) {
	sleep(std::numeric_limits<unsigned int>::max());
	}
	}

	// intended to run inside Android guest
	[[noreturn]] void VsockServer() {
	LOG(DEBUG) << "Starting vsock server on " << FLAGS_vsock_port;
	cuttlefish::SharedFD vsock;
	if (FLAGS_server_fd < 0) {
	do {
	vsock = cuttlefish::SharedFD::VsockServer(FLAGS_vsock_port, SOCK_STREAM);
	if (!vsock->IsOpen() && !socketErrorIsRecoverable(vsock->GetErrno())) {
	LOG(ERROR) << "Could not open vsock socket: " << vsock->StrError();
	SleepForever();
	}
	} while (!vsock->IsOpen());
	} else {
	vsock = cuttlefish::SharedFD::Dup(FLAGS_server_fd);
	close(FLAGS_server_fd);
	}
	CHECK(vsock->IsOpen()) << "Could not start server on " << FLAGS_vsock_port;
	while (true) {
	LOG(DEBUG) << "waiting for vsock connection";
	auto vsock_client = cuttlefish::SharedFD::Accept(*vsock);
	CHECK(vsock_client->IsOpen()) << "error creating vsock socket";
	LOG(DEBUG) << "vsock socket accepted";
	auto client = OpenSocketConnection();
	CHECK(client->IsOpen()) << "error connecting to guest client";
	auto thread = std::thread(HandleConnection, std::move(vsock_client),
	std::move(client));
	thread.detach();
	}
	}

	} // namespace

	int main(int argc, char* argv[]) {
	#ifdef CUTTLEFISH_HOST
	cuttlefish::DefaultSubprocessLogging(argv);
	#else
	::android::base::InitLogging(argv, android::base::LogdLogger());
	#endif
	google::ParseCommandLineFlags(&argc, &argv, true);

	CHECK((FLAGS_server == "tcp" && FLAGS_server_fd >= 0) \|\| FLAGS_tcp_port != 0)
	<< "Must specify -tcp_port or -server_fd (with -server=tcp) flag";
	CHECK((FLAGS_server == "vsock" && FLAGS_server_fd >= 0) \|\|
	FLAGS_vsock_port != 0)
	<< "Must specify -vsock_port or -server_fd (with -server=vsock) flag";

	if (FLAGS_adbd_events_fd >= 0) {
	LOG(DEBUG) << "Wating AdbdStarted boot event from the kernel log";
	WaitForAdbdToBeStarted(FLAGS_adbd_events_fd);
	}

	if (FLAGS_server == "tcp") {
	CHECK(FLAGS_vsock_cid != 0) << "Must specify -vsock_cid flag";
	TcpServer();
	} else if (FLAGS_server == "vsock") {
	VsockServer();
	} else {
	LOG(FATAL) << "Unknown server type: " << FLAGS_server;
	}
	}