libwebserv/binder_server.cc - platform/system/webservd - Git at Google

 // Copyright 2016 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 "webserv_common/binder_constants.h"

 #include "libwebserv/binder_request_handler.h"
 #include "libwebserv/binder_server.h"
 #include "libwebserv/protocol_handler.h"
 #include "libwebserv/request_handler_callback.h"

 #include <map>
 #include <set>
 #include <string>
 #include <vector>

 using android::sp;
 using android::IBinder;
 using android::binder::Status;
 using android::webservd::IProtocolHandler;
 using android::webservd::IRequestHandler;
 using std::map;
 using std::pair;
 using std::set;
 using std::string;
 using std::unique_ptr;
 using std::vector;

 namespace libwebserv {

 class RequestHandlerRegistration {
  public:
   RequestHandlerRegistration(const string& url,
                              const string& method,
                              unique_ptr<RequestHandlerInterface> handler)
       : url_(url),
         method_(method),
         handler_(std::move(handler)),
         binder_handler_(new BinderRequestHandler(handler_.get())) {}

   ~RequestHandlerRegistration() { DropRemotes(); }

   void AddRemote(sp<IProtocolHandler> handler) {
     string guid;

     if (!handler->AddRequestHandler(url_,
                                     method_,
                                     binder_handler_,
                                     &guid).isOk()) {
       LOG(WARNING) << "Remote protocol handler failed to "
                    << "register new request handler.";
     }

     protos_.emplace_back(handler, guid);
   }

   void DropRemotes() {
     for (auto& proto : protos_) {
       if (!proto.first->RemoveRequestHandler(proto.second).isOk()) {
         LOG(WARNING) << "Could not remove request handler from remote.";
       }
     }
   }

  private:
   string url_;
   string method_;
   unique_ptr<RequestHandlerInterface> handler_;
   sp<IRequestHandler> binder_handler_;
   vector<pair<sp<IProtocolHandler>, string>> protos_;

   DISALLOW_COPY_AND_ASSIGN(RequestHandlerRegistration);
 };

 // This is libwebserv's binder based process local protocol
 // handler.  It wraps around a group of remote protocol handlers
 // that share a common name.  It exists independently of the
 // lifetime of the remote protocol handlers and is created on
 // either of:
 //   1) The local process requests a protocol handler by name
 //   2) We connect to the remote webservd process and it has a protocol
 //      handler with the given name.
 class BinderProtocolHandler : public ProtocolHandler {
  public:
   explicit BinderProtocolHandler(const string& name)
       : name_(name) {}

   virtual ~BinderProtocolHandler() {
     ResetRemoteProtocolHandlers();
   }

   bool AddRemote(sp<IProtocolHandler> handler) {
     string name;
     int32_t port;
     string protocol;

     if (!handler->GetName(&name).isOk()) {
       LOG(INFO) << "Could not get name of remote protocol handler.";
       return false;
     }

     CHECK(name == name_);

     if (!handler->GetPort(&port).isOk()) {
       LOG(INFO) << "Could not get port for remote protocol handler.";
       return false;
     }

     if (!handler->GetProtocol(&protocol).isOk()) {
       LOG(INFO) << "Could not get protocol for remote protocol handler.";
       return false;
     }

     ports_.insert(uint16_t(port));
     protocols_.insert(protocol);
     remote_handlers_.push_back(handler);

     for (auto& request_handler : request_handler_ids_) {
       request_handler.second->AddRemote(handler);
     }

     return true;
   }

   int AddHandler(const string& url,
                  const string& method,
                  unique_ptr<RequestHandlerInterface> handler) override {
     unique_ptr<RequestHandlerRegistration> registration(
         new RequestHandlerRegistration(url, method, std::move(handler)));

     for (sp<IProtocolHandler> remote : remote_handlers_) {
       registration->AddRemote(remote);
     }

     int id = last_handler_id_++;

     request_handler_ids_.emplace(id, std::move(registration));

     return id;
   }

   int AddHandlerCallback(
       const string& url,
       const string& method,
       const base::Callback<RequestHandlerInterface::HandlerSignature>&
           handler_callback) override {
     std::unique_ptr<RequestHandlerInterface> handler{
         new RequestHandlerCallback{handler_callback}};
     return AddHandler(url, method, std::move(handler));
   }

   bool RemoveHandler(int handler_id) override {
     return request_handler_ids_.erase(handler_id) > 0;
   }

   void ResetRemoteProtocolHandlers() {
     for (auto& it : request_handler_ids_) {
       it.second->DropRemotes();
     }

     remote_handlers_.clear();
   }

   bool IsConnected() const override { return !remote_handlers_.empty(); }
   string GetName() const override { return name_; }
   set<uint16_t> GetPorts() const override { return ports_; }
   set<string> GetProtocols() const override { return protocols_; }

   brillo::Blob GetCertificateFingerprint() const override {
     brillo::Blob result;

     for (auto& handler : remote_handlers_) {
       Status status = handler->GetCertificateFingerprint(&result);
       if (!status.isOk()) {
         LOG(WARNING) << "Could not get certificate fingerprint "
                      << "from protocol handler: " << status;
       } else if (!result.empty()) {
         break;
       }
     }

     return result;
   }

  private:
   int last_handler_id_ = 0;
   set<uint16_t> ports_;
   set<string> protocols_;
   string name_;
   vector<sp<IProtocolHandler>> remote_handlers_;

   // Map of local handler IDs to objects containing the various bits of IPC
   // state we need to maintain those handlers on the remote end.
   map<int,unique_ptr<RequestHandlerRegistration>> request_handler_ids_;

   DISALLOW_COPY_AND_ASSIGN(BinderProtocolHandler);
 };

 BinderServer::BinderServer(brillo::MessageLoop* message_loop,
                            const base::Closure& on_server_online,
                            const base::Closure& on_server_offline,
                            android::BinderWrapper* binder_wrapper)
     : message_loop_{message_loop},
       on_server_online_{on_server_online},
       on_server_offline_{on_server_offline},
       binder_wrapper_{binder_wrapper} {
   message_loop_->PostTask(FROM_HERE,
                           base::Bind(&BinderServer::TryConnecting,
                                      weak_ptr_factory_.GetWeakPtr()));
 }

 void BinderServer::TryConnecting() {
   ClearLocalState();
   sp<IBinder> binder = binder_wrapper_->GetService(
       webservd::kWebserverBinderServiceName);
   if (!binder.get()) {
     LOG(INFO) << "Webservd has not registered with service manager.";
   } else if (!BuildLocalState(binder)) {
     ClearLocalState();
   } else {
     // Got a binder, built up appropriate local state, our job is done.
     return;
   }
   message_loop_->PostDelayedTask(FROM_HERE,
                                  base::Bind(&BinderServer::TryConnecting,
                                             weak_ptr_factory_.GetWeakPtr()),
                                  base::TimeDelta::FromSeconds(1));
 }

 void BinderServer::ClearLocalState() {
   for (auto& local_handler: local_protocol_handlers_) {
     local_handler.second->ResetRemoteProtocolHandlers();
     if (!on_protocol_handler_disconnected_.is_null()) {
       message_loop_->PostTask(
           FROM_HERE, base::Bind(on_protocol_handler_disconnected_,
                                 base::Unretained(local_handler.second.get())));
     }
   }

   remote_server_.clear();
 }

 bool BinderServer::BuildLocalState(sp<IBinder> server) {
   remote_server_ = android::interface_cast<RemoteServer>(server);
   vector<sp<IBinder>> remote_raw_binders;
   if (!remote_server_->GetProtocolHandlers("", &remote_raw_binders).isOk()) {
     // Possibly the server died, this is not necessarily an error.
     LOG(INFO) << "Webservd failed to tell us about protocol handlers.";
     return false;
   }

   // Tell the local wrappers about the remote handlers that exist now.
   for (auto& raw_binder: remote_raw_binders) {
     sp<RemoteProtocolHandler> remote_handler =
         android::interface_cast<RemoteProtocolHandler>(raw_binder);
     string name;
     if (!remote_handler->GetName(&name).isOk()) {
       LOG(INFO) << "Remote handler could not report its name.";
       return false;
     }

     auto it = local_protocol_handlers_.find(name);

     if (it == local_protocol_handlers_.end()) {
       unique_ptr<BinderProtocolHandler> local_handler(
           new BinderProtocolHandler(name));
       it = local_protocol_handlers_.emplace(name,
                                             std::move(local_handler)).first;
     }

     it->second->AddRemote(remote_handler);
     if (!on_protocol_handler_connected_.is_null()) {
       message_loop_->PostTask(FROM_HERE,
                               base::Bind(on_protocol_handler_connected_,
                                          base::Unretained(it->second.get())));
     }
   }
   return true;
 }

 ProtocolHandler* BinderServer::GetDefaultHttpHandler() {
   return GetProtocolHandler(ProtocolHandler::kHttp);
 }

 ProtocolHandler* BinderServer::GetDefaultHttpsHandler() {
   return GetProtocolHandler(ProtocolHandler::kHttps);
 }

 ProtocolHandler* BinderServer::GetProtocolHandler(const string& name) {
   auto it = local_protocol_handlers_.find(name);

   if (it == local_protocol_handlers_.end()) {
     unique_ptr<BinderProtocolHandler> local_handler(
         new BinderProtocolHandler(name));
     it = local_protocol_handlers_.emplace(name,
                                           std::move(local_handler)).first;
   }

   return it->second.get();
 }

 bool BinderServer::IsConnected() const {
   return remote_server_.get() != nullptr;
 }

 void BinderServer::OnProtocolHandlerConnected(
     const base::Callback<void(ProtocolHandler*)>& callback) {
   on_protocol_handler_connected_ = callback;

   for (auto& handler : local_protocol_handlers_) {
     if (handler.second->IsConnected()) {
       message_loop_->PostTask(
           FROM_HERE,
           base::Bind(callback, base::Unretained(handler.second.get())));
     }
   }
 }

 void BinderServer::OnProtocolHandlerDisconnected(
     const base::Callback<void(ProtocolHandler*)>& callback) {
   on_protocol_handler_disconnected_ = callback;

   for (auto& handler : local_protocol_handlers_) {
     if (!handler.second->IsConnected()) {
       message_loop_->PostTask(
           FROM_HERE,
           base::Bind(callback, base::Unretained(handler.second.get())));
     }
   }
 }

 base::TimeDelta BinderServer::GetDefaultRequestTimeout() const {
   int32_t timeout_seconds;
   if (!remote_server_->GetDefaultRequestTimeout(&timeout_seconds).isOk()) {
     LOG(ERROR) << "Could not get request timeout from remote server.";

     // Precedent from the DBus server says this is the error return value.
     return base::TimeDelta::Max();
   }

   return base::TimeDelta::FromSeconds(timeout_seconds);
 }

 }  // namespace libwebserv
	// Copyright 2016 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 "webserv_common/binder_constants.h"

	#include "libwebserv/binder_request_handler.h"
	#include "libwebserv/binder_server.h"
	#include "libwebserv/protocol_handler.h"
	#include "libwebserv/request_handler_callback.h"

	#include <map>
	#include <set>
	#include <string>
	#include <vector>

	using android::sp;
	using android::IBinder;
	using android::binder::Status;
	using android::webservd::IProtocolHandler;
	using android::webservd::IRequestHandler;
	using std::map;
	using std::pair;
	using std::set;
	using std::string;
	using std::unique_ptr;
	using std::vector;

	namespace libwebserv {

	class RequestHandlerRegistration {
	public:
	RequestHandlerRegistration(const string& url,
	const string& method,
	unique_ptr<RequestHandlerInterface> handler)
	: url_(url),
	method_(method),
	handler_(std::move(handler)),
	binder_handler_(new BinderRequestHandler(handler_.get())) {}

	~RequestHandlerRegistration() { DropRemotes(); }

	void AddRemote(sp<IProtocolHandler> handler) {
	string guid;

	if (!handler->AddRequestHandler(url_,
	method_,
	binder_handler_,
	&guid).isOk()) {
	LOG(WARNING) << "Remote protocol handler failed to "
	<< "register new request handler.";
	}

	protos_.emplace_back(handler, guid);
	}

	void DropRemotes() {
	for (auto& proto : protos_) {
	if (!proto.first->RemoveRequestHandler(proto.second).isOk()) {
	LOG(WARNING) << "Could not remove request handler from remote.";
	}
	}
	}

	private:
	string url_;
	string method_;
	unique_ptr<RequestHandlerInterface> handler_;
	sp<IRequestHandler> binder_handler_;
	vector<pair<sp<IProtocolHandler>, string>> protos_;

	DISALLOW_COPY_AND_ASSIGN(RequestHandlerRegistration);
	};

	// This is libwebserv's binder based process local protocol
	// handler. It wraps around a group of remote protocol handlers
	// that share a common name. It exists independently of the
	// lifetime of the remote protocol handlers and is created on
	// either of:
	// 1) The local process requests a protocol handler by name
	// 2) We connect to the remote webservd process and it has a protocol
	// handler with the given name.
	class BinderProtocolHandler : public ProtocolHandler {
	public:
	explicit BinderProtocolHandler(const string& name)
	: name_(name) {}

	virtual ~BinderProtocolHandler() {
	ResetRemoteProtocolHandlers();
	}

	bool AddRemote(sp<IProtocolHandler> handler) {
	string name;
	int32_t port;
	string protocol;

	if (!handler->GetName(&name).isOk()) {
	LOG(INFO) << "Could not get name of remote protocol handler.";
	return false;
	}

	CHECK(name == name_);

	if (!handler->GetPort(&port).isOk()) {
	LOG(INFO) << "Could not get port for remote protocol handler.";
	return false;
	}

	if (!handler->GetProtocol(&protocol).isOk()) {
	LOG(INFO) << "Could not get protocol for remote protocol handler.";
	return false;
	}

	ports_.insert(uint16_t(port));
	protocols_.insert(protocol);
	remote_handlers_.push_back(handler);

	for (auto& request_handler : request_handler_ids_) {
	request_handler.second->AddRemote(handler);
	}

	return true;
	}

	int AddHandler(const string& url,
	const string& method,
	unique_ptr<RequestHandlerInterface> handler) override {
	unique_ptr<RequestHandlerRegistration> registration(
	new RequestHandlerRegistration(url, method, std::move(handler)));

	for (sp<IProtocolHandler> remote : remote_handlers_) {
	registration->AddRemote(remote);
	}

	int id = last_handler_id_++;

	request_handler_ids_.emplace(id, std::move(registration));

	return id;
	}

	int AddHandlerCallback(
	const string& url,
	const string& method,
	const base::Callback<RequestHandlerInterface::HandlerSignature>&
	handler_callback) override {
	std::unique_ptr<RequestHandlerInterface> handler{
	new RequestHandlerCallback{handler_callback}};
	return AddHandler(url, method, std::move(handler));
	}

	bool RemoveHandler(int handler_id) override {
	return request_handler_ids_.erase(handler_id) > 0;
	}

	void ResetRemoteProtocolHandlers() {
	for (auto& it : request_handler_ids_) {
	it.second->DropRemotes();
	}

	remote_handlers_.clear();
	}

	bool IsConnected() const override { return !remote_handlers_.empty(); }
	string GetName() const override { return name_; }
	set<uint16_t> GetPorts() const override { return ports_; }
	set<string> GetProtocols() const override { return protocols_; }

	brillo::Blob GetCertificateFingerprint() const override {
	brillo::Blob result;

	for (auto& handler : remote_handlers_) {
	Status status = handler->GetCertificateFingerprint(&result);
	if (!status.isOk()) {
	LOG(WARNING) << "Could not get certificate fingerprint "
	<< "from protocol handler: " << status;
	} else if (!result.empty()) {
	break;
	}
	}

	return result;
	}

	private:
	int last_handler_id_ = 0;
	set<uint16_t> ports_;
	set<string> protocols_;
	string name_;
	vector<sp<IProtocolHandler>> remote_handlers_;

	// Map of local handler IDs to objects containing the various bits of IPC
	// state we need to maintain those handlers on the remote end.
	map<int,unique_ptr<RequestHandlerRegistration>> request_handler_ids_;

	DISALLOW_COPY_AND_ASSIGN(BinderProtocolHandler);
	};

	BinderServer::BinderServer(brillo::MessageLoop* message_loop,
	const base::Closure& on_server_online,
	const base::Closure& on_server_offline,
	android::BinderWrapper* binder_wrapper)
	: message_loop_{message_loop},
	on_server_online_{on_server_online},
	on_server_offline_{on_server_offline},
	binder_wrapper_{binder_wrapper} {
	message_loop_->PostTask(FROM_HERE,
	base::Bind(&BinderServer::TryConnecting,
	weak_ptr_factory_.GetWeakPtr()));
	}

	void BinderServer::TryConnecting() {
	ClearLocalState();
	sp<IBinder> binder = binder_wrapper_->GetService(
	webservd::kWebserverBinderServiceName);
	if (!binder.get()) {
	LOG(INFO) << "Webservd has not registered with service manager.";
	} else if (!BuildLocalState(binder)) {
	ClearLocalState();
	} else {
	// Got a binder, built up appropriate local state, our job is done.
	return;
	}
	message_loop_->PostDelayedTask(FROM_HERE,
	base::Bind(&BinderServer::TryConnecting,
	weak_ptr_factory_.GetWeakPtr()),
	base::TimeDelta::FromSeconds(1));
	}

	void BinderServer::ClearLocalState() {
	for (auto& local_handler: local_protocol_handlers_) {
	local_handler.second->ResetRemoteProtocolHandlers();
	if (!on_protocol_handler_disconnected_.is_null()) {
	message_loop_->PostTask(
	FROM_HERE, base::Bind(on_protocol_handler_disconnected_,
	base::Unretained(local_handler.second.get())));
	}
	}

	remote_server_.clear();
	}

	bool BinderServer::BuildLocalState(sp<IBinder> server) {
	remote_server_ = android::interface_cast<RemoteServer>(server);
	vector<sp<IBinder>> remote_raw_binders;
	if (!remote_server_->GetProtocolHandlers("", &remote_raw_binders).isOk()) {
	// Possibly the server died, this is not necessarily an error.
	LOG(INFO) << "Webservd failed to tell us about protocol handlers.";
	return false;
	}

	// Tell the local wrappers about the remote handlers that exist now.
	for (auto& raw_binder: remote_raw_binders) {
	sp<RemoteProtocolHandler> remote_handler =
	android::interface_cast<RemoteProtocolHandler>(raw_binder);
	string name;
	if (!remote_handler->GetName(&name).isOk()) {
	LOG(INFO) << "Remote handler could not report its name.";
	return false;
	}

	auto it = local_protocol_handlers_.find(name);

	if (it == local_protocol_handlers_.end()) {
	unique_ptr<BinderProtocolHandler> local_handler(
	new BinderProtocolHandler(name));
	it = local_protocol_handlers_.emplace(name,
	std::move(local_handler)).first;
	}

	it->second->AddRemote(remote_handler);
	if (!on_protocol_handler_connected_.is_null()) {
	message_loop_->PostTask(FROM_HERE,
	base::Bind(on_protocol_handler_connected_,
	base::Unretained(it->second.get())));
	}
	}
	return true;
	}

	ProtocolHandler* BinderServer::GetDefaultHttpHandler() {
	return GetProtocolHandler(ProtocolHandler::kHttp);
	}

	ProtocolHandler* BinderServer::GetDefaultHttpsHandler() {
	return GetProtocolHandler(ProtocolHandler::kHttps);
	}

	ProtocolHandler* BinderServer::GetProtocolHandler(const string& name) {
	auto it = local_protocol_handlers_.find(name);

	if (it == local_protocol_handlers_.end()) {
	unique_ptr<BinderProtocolHandler> local_handler(
	new BinderProtocolHandler(name));
	it = local_protocol_handlers_.emplace(name,
	std::move(local_handler)).first;
	}

	return it->second.get();
	}

	bool BinderServer::IsConnected() const {
	return remote_server_.get() != nullptr;
	}

	void BinderServer::OnProtocolHandlerConnected(
	const base::Callback<void(ProtocolHandler*)>& callback) {
	on_protocol_handler_connected_ = callback;

	for (auto& handler : local_protocol_handlers_) {
	if (handler.second->IsConnected()) {
	message_loop_->PostTask(
	FROM_HERE,
	base::Bind(callback, base::Unretained(handler.second.get())));
	}
	}
	}

	void BinderServer::OnProtocolHandlerDisconnected(
	const base::Callback<void(ProtocolHandler*)>& callback) {
	on_protocol_handler_disconnected_ = callback;

	for (auto& handler : local_protocol_handlers_) {
	if (!handler.second->IsConnected()) {
	message_loop_->PostTask(
	FROM_HERE,
	base::Bind(callback, base::Unretained(handler.second.get())));
	}
	}
	}

	base::TimeDelta BinderServer::GetDefaultRequestTimeout() const {
	int32_t timeout_seconds;
	if (!remote_server_->GetDefaultRequestTimeout(&timeout_seconds).isOk()) {
	LOG(ERROR) << "Could not get request timeout from remote server.";

	// Precedent from the DBus server says this is the error return value.
	return base::TimeDelta::Max();
	}

	return base::TimeDelta::FromSeconds(timeout_seconds);
	}

	} // namespace libwebserv