1 // Copyright 2018 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "osp/impl/internal_services.h"
6
7 #include <algorithm>
8 #include <utility>
9
10 #include "osp/impl/discovery/mdns/mdns_responder_adapter_impl.h"
11 #include "osp/impl/mdns_responder_service.h"
12 #include "platform/api/udp_socket.h"
13 #include "platform/base/error.h"
14 #include "util/osp_logging.h"
15
16 namespace openscreen {
17 namespace osp {
18 namespace {
19
20 constexpr char kServiceName[] = "_openscreen";
21 constexpr char kServiceProtocol[] = "_udp";
22 const IPAddress kMulticastAddress{224, 0, 0, 251};
23 const IPAddress kMulticastIPv6Address{
24 // ff02::fb
25 0xff02, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x00fb,
26 };
27 const uint16_t kMulticastListeningPort = 5353;
28
29 class MdnsResponderAdapterImplFactory final
30 : public MdnsResponderAdapterFactory {
31 public:
32 MdnsResponderAdapterImplFactory() = default;
33 ~MdnsResponderAdapterImplFactory() override = default;
34
Create()35 std::unique_ptr<MdnsResponderAdapter> Create() override {
36 return std::make_unique<MdnsResponderAdapterImpl>();
37 }
38 };
39
SetUpMulticastSocket(UdpSocket * socket,NetworkInterfaceIndex ifindex)40 Error SetUpMulticastSocket(UdpSocket* socket, NetworkInterfaceIndex ifindex) {
41 const IPAddress broadcast_address =
42 socket->IsIPv6() ? kMulticastIPv6Address : kMulticastAddress;
43
44 socket->JoinMulticastGroup(broadcast_address, ifindex);
45 socket->SetMulticastOutboundInterface(ifindex);
46 socket->Bind();
47
48 return Error::None();
49 }
50
51 // Ref-counted singleton instance of InternalServices. This lives only as long
52 // as there is at least one ServiceListener and/or ServicePublisher alive.
53 InternalServices* g_instance = nullptr;
54 int g_instance_ref_count = 0;
55
56 } // namespace
57
58 // static
CreateListener(const MdnsServiceListenerConfig & config,ServiceListener::Observer * observer,TaskRunner * task_runner)59 std::unique_ptr<ServiceListener> InternalServices::CreateListener(
60 const MdnsServiceListenerConfig& config,
61 ServiceListener::Observer* observer,
62 TaskRunner* task_runner) {
63 auto* services = ReferenceSingleton(task_runner);
64 auto listener =
65 std::make_unique<ServiceListenerImpl>(&services->mdns_service_);
66 listener->AddObserver(observer);
67 listener->SetDestructionCallback(&InternalServices::DereferenceSingleton,
68 services);
69 return listener;
70 }
71
72 // static
CreatePublisher(const ServicePublisher::Config & config,ServicePublisher::Observer * observer,TaskRunner * task_runner)73 std::unique_ptr<ServicePublisher> InternalServices::CreatePublisher(
74 const ServicePublisher::Config& config,
75 ServicePublisher::Observer* observer,
76 TaskRunner* task_runner) {
77 auto* services = ReferenceSingleton(task_runner);
78 services->mdns_service_.SetServiceConfig(
79 config.hostname, config.service_instance_name,
80 config.connection_server_port, config.network_interface_indices,
81 {{"fn", config.friendly_name}});
82 auto publisher = std::make_unique<ServicePublisherImpl>(
83 observer, &services->mdns_service_);
84 publisher->SetDestructionCallback(&InternalServices::DereferenceSingleton,
85 services);
86 return publisher;
87 }
88
InternalPlatformLinkage(InternalServices * parent)89 InternalServices::InternalPlatformLinkage::InternalPlatformLinkage(
90 InternalServices* parent)
91 : parent_(parent) {}
92
~InternalPlatformLinkage()93 InternalServices::InternalPlatformLinkage::~InternalPlatformLinkage() {
94 // If there are open sockets, then there will be dangling references to
95 // destroyed objects after destruction.
96 OSP_CHECK(open_sockets_.empty());
97 }
98
99 std::vector<MdnsPlatformService::BoundInterface>
RegisterInterfaces(const std::vector<NetworkInterfaceIndex> & allowlist)100 InternalServices::InternalPlatformLinkage::RegisterInterfaces(
101 const std::vector<NetworkInterfaceIndex>& allowlist) {
102 const std::vector<InterfaceInfo> interfaces = GetNetworkInterfaces();
103 const bool do_filter_using_allowlist = !allowlist.empty();
104 std::vector<NetworkInterfaceIndex> index_list;
105 for (const auto& interface : interfaces) {
106 OSP_VLOG << "Found interface: " << interface;
107 if (do_filter_using_allowlist &&
108 std::find(allowlist.begin(), allowlist.end(), interface.index) ==
109 allowlist.end()) {
110 OSP_VLOG << "Ignoring interface not in allowed list: " << interface;
111 continue;
112 }
113 if (!interface.addresses.empty())
114 index_list.push_back(interface.index);
115 }
116 OSP_LOG_IF(WARN, index_list.empty())
117 << "No network interfaces had usable addresses for mDNS.";
118
119 // Set up sockets to send and listen to mDNS multicast traffic on all
120 // interfaces.
121 std::vector<BoundInterface> result;
122 for (NetworkInterfaceIndex index : index_list) {
123 const auto& interface = *std::find_if(
124 interfaces.begin(), interfaces.end(),
125 [index](const InterfaceInfo& info) { return info.index == index; });
126 if (interface.addresses.empty()) {
127 continue;
128 }
129
130 // Pick any address for the given interface.
131 const IPSubnet& primary_subnet = interface.addresses.front();
132
133 auto create_result =
134 UdpSocket::Create(parent_->task_runner_, parent_,
135 IPEndpoint{{}, kMulticastListeningPort});
136 if (!create_result) {
137 OSP_LOG_ERROR << "failed to create socket for interface " << index << ": "
138 << create_result.error().message();
139 continue;
140 }
141 std::unique_ptr<UdpSocket> socket = std::move(create_result.value());
142 if (!SetUpMulticastSocket(socket.get(), index).ok()) {
143 continue;
144 }
145 result.emplace_back(interface, primary_subnet, socket.get());
146 parent_->RegisterMdnsSocket(socket.get());
147
148 open_sockets_.emplace_back(std::move(socket));
149 }
150
151 return result;
152 }
153
DeregisterInterfaces(const std::vector<BoundInterface> & registered_interfaces)154 void InternalServices::InternalPlatformLinkage::DeregisterInterfaces(
155 const std::vector<BoundInterface>& registered_interfaces) {
156 for (const auto& interface : registered_interfaces) {
157 UdpSocket* const socket = interface.socket;
158 parent_->DeregisterMdnsSocket(socket);
159
160 const auto it = std::find_if(open_sockets_.begin(), open_sockets_.end(),
161 [socket](const std::unique_ptr<UdpSocket>& s) {
162 return s.get() == socket;
163 });
164 OSP_DCHECK(it != open_sockets_.end());
165 open_sockets_.erase(it);
166 }
167 }
168
InternalServices(ClockNowFunctionPtr now_function,TaskRunner * task_runner)169 InternalServices::InternalServices(ClockNowFunctionPtr now_function,
170 TaskRunner* task_runner)
171 : mdns_service_(now_function,
172 task_runner,
173 kServiceName,
174 kServiceProtocol,
175 std::make_unique<MdnsResponderAdapterImplFactory>(),
176 std::make_unique<InternalPlatformLinkage>(this)),
177 task_runner_(task_runner) {}
178
179 InternalServices::~InternalServices() = default;
180
RegisterMdnsSocket(UdpSocket * socket)181 void InternalServices::RegisterMdnsSocket(UdpSocket* socket) {
182 OSP_CHECK(g_instance) << "No listener or publisher is alive.";
183 // TODO(rwkeane): Hook this up to the new mDNS library once we swap out the
184 // mDNSResponder.
185 }
186
DeregisterMdnsSocket(UdpSocket * socket)187 void InternalServices::DeregisterMdnsSocket(UdpSocket* socket) {
188 // TODO(rwkeane): Hook this up to the new mDNS library once we swap out the
189 // mDNSResponder.
190 }
191
192 // static
ReferenceSingleton(TaskRunner * task_runner)193 InternalServices* InternalServices::ReferenceSingleton(
194 TaskRunner* task_runner) {
195 if (!g_instance) {
196 OSP_CHECK_EQ(g_instance_ref_count, 0);
197 g_instance = new InternalServices(&Clock::now, task_runner);
198 }
199 ++g_instance_ref_count;
200 return g_instance;
201 }
202
203 // static
DereferenceSingleton(void * instance)204 void InternalServices::DereferenceSingleton(void* instance) {
205 OSP_CHECK_EQ(static_cast<InternalServices*>(instance), g_instance);
206 OSP_CHECK_GT(g_instance_ref_count, 0);
207 --g_instance_ref_count;
208 if (g_instance_ref_count == 0) {
209 delete g_instance;
210 g_instance = nullptr;
211 }
212 }
213
OnError(UdpSocket * socket,Error error)214 void InternalServices::OnError(UdpSocket* socket, Error error) {
215 OSP_LOG_ERROR << "failed to configure socket " << error.message();
216 this->DeregisterMdnsSocket(socket);
217 }
218
OnSendError(UdpSocket * socket,Error error)219 void InternalServices::OnSendError(UdpSocket* socket, Error error) {
220 // TODO(crbug.com/openscreen/67): Implement this method.
221 OSP_UNIMPLEMENTED();
222 }
223
OnRead(UdpSocket * socket,ErrorOr<UdpPacket> packet)224 void InternalServices::OnRead(UdpSocket* socket, ErrorOr<UdpPacket> packet) {
225 g_instance->mdns_service_.OnRead(socket, std::move(packet));
226 }
227
228 } // namespace osp
229 } // namespace openscreen
230