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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.
#include "osp/impl/internal_services.h"
#include <algorithm>
#include <utility>
#include "osp/impl/discovery/mdns/mdns_responder_adapter_impl.h"
#include "osp/impl/mdns_responder_service.h"
#include "platform/api/udp_socket.h"
#include "platform/base/error.h"
#include "util/osp_logging.h"
namespace openscreen {
namespace osp {
namespace {
constexpr char kServiceName[] = "_openscreen";
constexpr char kServiceProtocol[] = "_udp";
const IPAddress kMulticastAddress{224, 0, 0, 251};
const IPAddress kMulticastIPv6Address{
// ff02::fb
0xff02, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x00fb,
};
const uint16_t kMulticastListeningPort = 5353;
class MdnsResponderAdapterImplFactory final
: public MdnsResponderAdapterFactory {
public:
MdnsResponderAdapterImplFactory() = default;
~MdnsResponderAdapterImplFactory() override = default;
std::unique_ptr<MdnsResponderAdapter> Create() override {
return std::make_unique<MdnsResponderAdapterImpl>();
}
};
Error SetUpMulticastSocket(UdpSocket* socket, NetworkInterfaceIndex ifindex) {
const IPAddress broadcast_address =
socket->IsIPv6() ? kMulticastIPv6Address : kMulticastAddress;
socket->JoinMulticastGroup(broadcast_address, ifindex);
socket->SetMulticastOutboundInterface(ifindex);
socket->Bind();
return Error::None();
}
// Ref-counted singleton instance of InternalServices. This lives only as long
// as there is at least one ServiceListener and/or ServicePublisher alive.
InternalServices* g_instance = nullptr;
int g_instance_ref_count = 0;
} // namespace
// static
std::unique_ptr<ServiceListener> InternalServices::CreateListener(
const MdnsServiceListenerConfig& config,
ServiceListener::Observer* observer,
TaskRunner* task_runner) {
auto* services = ReferenceSingleton(task_runner);
auto listener =
std::make_unique<ServiceListenerImpl>(&services->mdns_service_);
listener->AddObserver(observer);
listener->SetDestructionCallback(&InternalServices::DereferenceSingleton,
services);
return listener;
}
// static
std::unique_ptr<ServicePublisher> InternalServices::CreatePublisher(
const ServicePublisher::Config& config,
ServicePublisher::Observer* observer,
TaskRunner* task_runner) {
auto* services = ReferenceSingleton(task_runner);
services->mdns_service_.SetServiceConfig(
config.hostname, config.service_instance_name,
config.connection_server_port, config.network_interface_indices,
{{"fn", config.friendly_name}});
auto publisher = std::make_unique<ServicePublisherImpl>(
observer, &services->mdns_service_);
publisher->SetDestructionCallback(&InternalServices::DereferenceSingleton,
services);
return publisher;
}
InternalServices::InternalPlatformLinkage::InternalPlatformLinkage(
InternalServices* parent)
: parent_(parent) {}
InternalServices::InternalPlatformLinkage::~InternalPlatformLinkage() {
// If there are open sockets, then there will be dangling references to
// destroyed objects after destruction.
OSP_CHECK(open_sockets_.empty());
}
std::vector<MdnsPlatformService::BoundInterface>
InternalServices::InternalPlatformLinkage::RegisterInterfaces(
const std::vector<NetworkInterfaceIndex>& allowlist) {
const std::vector<InterfaceInfo> interfaces = GetNetworkInterfaces();
const bool do_filter_using_allowlist = !allowlist.empty();
std::vector<NetworkInterfaceIndex> index_list;
for (const auto& interface : interfaces) {
OSP_VLOG << "Found interface: " << interface;
if (do_filter_using_allowlist &&
std::find(allowlist.begin(), allowlist.end(), interface.index) ==
allowlist.end()) {
OSP_VLOG << "Ignoring interface not in allowed list: " << interface;
continue;
}
if (!interface.addresses.empty())
index_list.push_back(interface.index);
}
OSP_LOG_IF(WARN, index_list.empty())
<< "No network interfaces had usable addresses for mDNS.";
// Set up sockets to send and listen to mDNS multicast traffic on all
// interfaces.
std::vector<BoundInterface> result;
for (NetworkInterfaceIndex index : index_list) {
const auto& interface = *std::find_if(
interfaces.begin(), interfaces.end(),
[index](const InterfaceInfo& info) { return info.index == index; });
if (interface.addresses.empty()) {
continue;
}
// Pick any address for the given interface.
const IPSubnet& primary_subnet = interface.addresses.front();
auto create_result =
UdpSocket::Create(parent_->task_runner_, parent_,
IPEndpoint{{}, kMulticastListeningPort});
if (!create_result) {
OSP_LOG_ERROR << "failed to create socket for interface " << index << ": "
<< create_result.error().message();
continue;
}
std::unique_ptr<UdpSocket> socket = std::move(create_result.value());
if (!SetUpMulticastSocket(socket.get(), index).ok()) {
continue;
}
result.emplace_back(interface, primary_subnet, socket.get());
parent_->RegisterMdnsSocket(socket.get());
open_sockets_.emplace_back(std::move(socket));
}
return result;
}
void InternalServices::InternalPlatformLinkage::DeregisterInterfaces(
const std::vector<BoundInterface>& registered_interfaces) {
for (const auto& interface : registered_interfaces) {
UdpSocket* const socket = interface.socket;
parent_->DeregisterMdnsSocket(socket);
const auto it = std::find_if(open_sockets_.begin(), open_sockets_.end(),
[socket](const std::unique_ptr<UdpSocket>& s) {
return s.get() == socket;
});
OSP_DCHECK(it != open_sockets_.end());
open_sockets_.erase(it);
}
}
InternalServices::InternalServices(ClockNowFunctionPtr now_function,
TaskRunner* task_runner)
: mdns_service_(now_function,
task_runner,
kServiceName,
kServiceProtocol,
std::make_unique<MdnsResponderAdapterImplFactory>(),
std::make_unique<InternalPlatformLinkage>(this)),
task_runner_(task_runner) {}
InternalServices::~InternalServices() = default;
void InternalServices::RegisterMdnsSocket(UdpSocket* socket) {
OSP_CHECK(g_instance) << "No listener or publisher is alive.";
// TODO(rwkeane): Hook this up to the new mDNS library once we swap out the
// mDNSResponder.
}
void InternalServices::DeregisterMdnsSocket(UdpSocket* socket) {
// TODO(rwkeane): Hook this up to the new mDNS library once we swap out the
// mDNSResponder.
}
// static
InternalServices* InternalServices::ReferenceSingleton(
TaskRunner* task_runner) {
if (!g_instance) {
OSP_CHECK_EQ(g_instance_ref_count, 0);
g_instance = new InternalServices(&Clock::now, task_runner);
}
++g_instance_ref_count;
return g_instance;
}
// static
void InternalServices::DereferenceSingleton(void* instance) {
OSP_CHECK_EQ(static_cast<InternalServices*>(instance), g_instance);
OSP_CHECK_GT(g_instance_ref_count, 0);
--g_instance_ref_count;
if (g_instance_ref_count == 0) {
delete g_instance;
g_instance = nullptr;
}
}
void InternalServices::OnError(UdpSocket* socket, Error error) {
OSP_LOG_ERROR << "failed to configure socket " << error.message();
this->DeregisterMdnsSocket(socket);
}
void InternalServices::OnSendError(UdpSocket* socket, Error error) {
// TODO(crbug.com/openscreen/67): Implement this method.
OSP_UNIMPLEMENTED();
}
void InternalServices::OnRead(UdpSocket* socket, ErrorOr<UdpPacket> packet) {
g_instance->mdns_service_.OnRead(socket, std::move(packet));
}
} // namespace osp
} // namespace openscreen
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