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// Copyright 2018 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef MOJO_PUBLIC_CPP_PLATFORM_NAMED_PLATFORM_CHANNEL_H_
#define MOJO_PUBLIC_CPP_PLATFORM_NAMED_PLATFORM_CHANNEL_H_
#include <string>
#include "base/command_line.h"
#include "base/component_export.h"
#include "base/strings/string_piece.h"
#include "build/build_config.h"
#include "mojo/public/cpp/platform/platform_channel_endpoint.h"
#include "mojo/public/cpp/platform/platform_channel_server_endpoint.h"
#if defined(OS_POSIX)
#include "base/files/file_path.h"
#endif
namespace mojo {
// NamedPlatformChannel encapsulates a Mojo invitation transport channel which
// can listen for inbound connections established by clients connecting to
// a named system resource (i.e. a named pipe server on Windows, a named Unix
// domain socket on POSIX, a Mach bootstrap server on macOS, other platforms
// not supported).
//
// This can be especially useful when the local process has no way to transfer
// handles to the remote process, e.g. it does not control process launch or
// have any pre-existing communication channel to the process.
class COMPONENT_EXPORT(MOJO_CPP_PLATFORM) NamedPlatformChannel {
public:
static const char kNamedHandleSwitch[];
#if defined(OS_WIN)
using ServerName = std::wstring;
#else
using ServerName = std::string;
#endif
struct COMPONENT_EXPORT(MOJO_CPP_PLATFORM) Options {
// Specifies the name to use for the server. If empty, a random name is
// generated.
ServerName server_name;
#if defined(OS_WIN)
// If non-empty, a security descriptor to use when creating the pipe. If
// empty, a default security descriptor will be used. See
// |kDefaultSecurityDescriptor|.
std::wstring security_descriptor;
// If |true|, only a server endpoint will be allowed with the given name and
// only one client will be able to connect. Otherwise many
// NamedPlatformChannel instances can be created with the same name and
// a different client can connect to each one.
bool enforce_uniqueness = true;
#elif defined(OS_POSIX)
// On POSIX, every new unnamed NamedPlatformChannel creates a server socket
// with a random name. This controls the directory where that happens.
// Ignored if |server_name| was set explicitly.
base::FilePath socket_dir;
#endif
};
NamedPlatformChannel(const Options& options);
NamedPlatformChannel(NamedPlatformChannel&& other);
NamedPlatformChannel(const NamedPlatformChannel&) = delete;
NamedPlatformChannel& operator=(const NamedPlatformChannel&) = delete;
~NamedPlatformChannel();
NamedPlatformChannel& operator=(NamedPlatformChannel&& other);
const PlatformChannelServerEndpoint& server_endpoint() const {
return server_endpoint_;
}
// Helper to create a ServerName from a UTF8 string regardless of platform.
static ServerName ServerNameFromUTF8(base::StringPiece name);
// Passes the local server endpoint for the channel. On Windows, this is a
// named pipe server; on POSIX it's a bound, listening domain socket. In each
// case it should accept a single new connection.
//
// Use the handle to send or receive an invitation, with the endpoint type as
// |MOJO_INVITATION_TRANSPORT_TYPE_CHANNEL_SERVER|.
PlatformChannelServerEndpoint TakeServerEndpoint() WARN_UNUSED_RESULT {
return std::move(server_endpoint_);
}
// Returns a name that can be used a remote process to connect to the server
// endpoint.
const ServerName& GetServerName() const { return server_name_; }
// Passes the server name on |*command_line| using the common
// |kNamedHandleSwitch| flag.
void PassServerNameOnCommandLine(base::CommandLine* command_line);
// Recovers a functioning client endpoint handle by creating a new endpoint
// and connecting it to |server_name| if possible.
static PlatformChannelEndpoint ConnectToServer(const ServerName& server_name)
WARN_UNUSED_RESULT;
// Like above, but extracts the server name from |command_line| using the
// common |kNamedHandleSwitch| flag.
static PlatformChannelEndpoint ConnectToServer(
const base::CommandLine& command_line) WARN_UNUSED_RESULT;
private:
static PlatformChannelServerEndpoint CreateServerEndpoint(
const Options& options,
ServerName* server_name);
static PlatformChannelEndpoint CreateClientEndpoint(
const ServerName& server_name);
ServerName server_name_;
PlatformChannelServerEndpoint server_endpoint_;
};
} // namespace mojo
#endif // MOJO_PUBLIC_CPP_PLATFORM_NAMED_PLATFORM_CHANNEL_H_