blob: 8b6b6235fa2f9a02e0133fe231f278bdb991a513 [file] [log] [blame]
* Copyright 2004 The WebRTC Project Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
#include <stdint.h>
#include <deque>
#include <map>
#include <memory>
#include <string>
#include <vector>
#include "api/sequence_checker.h"
#include "rtc_base/ip_address.h"
#include "rtc_base/mdns_responder_interface.h"
#include "rtc_base/message_handler.h"
#include "rtc_base/network_monitor.h"
#include "rtc_base/network_monitor_factory.h"
#include "rtc_base/system/rtc_export.h"
#include "rtc_base/third_party/sigslot/sigslot.h"
#include "rtc_base/thread_annotations.h"
#if defined(WEBRTC_POSIX)
struct ifaddrs;
#endif // defined(WEBRTC_POSIX)
namespace rtc {
extern const char kPublicIPv4Host[];
extern const char kPublicIPv6Host[];
class IfAddrsConverter;
class Network;
class NetworkMonitorInterface;
class Thread;
// By default, ignore loopback interfaces on the host.
const int kDefaultNetworkIgnoreMask = ADAPTER_TYPE_LOOPBACK;
// Makes a string key for this network. Used in the network manager's maps.
// Network objects are keyed on interface name, network prefix and the
// length of that prefix.
std::string MakeNetworkKey(const std::string& name,
const IPAddress& prefix,
int prefix_length);
// Utility function that attempts to determine an adapter type by an interface
// name (e.g., "wlan0"). Can be used by NetworkManager subclasses when other
// mechanisms fail to determine the type.
RTC_EXPORT AdapterType GetAdapterTypeFromName(const char* network_name);
class DefaultLocalAddressProvider {
virtual ~DefaultLocalAddressProvider() = default;
// The default local address is the local address used in multi-homed endpoint
// when the any address ( or ::) is used as the local address. It's
// important to check the return value as a IP family may not be enabled.
virtual bool GetDefaultLocalAddress(int family, IPAddress* ipaddr) const = 0;
class MdnsResponderProvider {
virtual ~MdnsResponderProvider() = default;
// Returns the mDNS responder that can be used to obfuscate the local IP
// addresses of ICE host candidates by mDNS hostnames.
// The provider MUST outlive the mDNS responder.
virtual webrtc::MdnsResponderInterface* GetMdnsResponder() const = 0;
// Generic network manager interface. It provides list of local
// networks.
// Every method of NetworkManager (including the destructor) must be called on
// the same thread, except for the constructor which may be called on any
// thread.
// This allows constructing a NetworkManager subclass on one thread and
// passing it into an object that uses it on a different thread.
class RTC_EXPORT NetworkManager : public DefaultLocalAddressProvider,
public MdnsResponderProvider {
typedef std::vector<Network*> NetworkList;
// This enum indicates whether adapter enumeration is allowed.
enum EnumerationPermission {
ENUMERATION_ALLOWED, // Adapter enumeration is allowed. Getting 0 network
// from GetNetworks means that there is no network
// available.
ENUMERATION_BLOCKED, // Adapter enumeration is disabled.
// GetAnyAddressNetworks() should be used instead.
~NetworkManager() override;
// Called when network list is updated.
sigslot::signal0<> SignalNetworksChanged;
// Indicates a failure when getting list of network interfaces.
sigslot::signal0<> SignalError;
// This should be called on the NetworkManager's thread before the
// NetworkManager is used. Subclasses may override this if necessary.
virtual void Initialize() {}
// Start/Stop monitoring of network interfaces
// list. SignalNetworksChanged or SignalError is emitted immediately
// after StartUpdating() is called. After that SignalNetworksChanged
// is emitted whenever list of networks changes.
virtual void StartUpdating() = 0;
virtual void StopUpdating() = 0;
// Returns the current list of networks available on this machine.
// StartUpdating() must be called before this method is called.
// It makes sure that repeated calls return the same object for a
// given network, so that quality is tracked appropriately. Does not
// include ignored networks.
virtual void GetNetworks(NetworkList* networks) const = 0;
// Returns the current permission state of GetNetworks().
virtual EnumerationPermission enumeration_permission() const;
// "AnyAddressNetwork" is a network which only contains single "any address"
// IP address. (i.e. INADDR_ANY for IPv4 or in6addr_any for IPv6). This is
// useful as binding to such interfaces allow default routing behavior like
// http traffic.
// This method appends the "any address" networks to the list, such that this
// can optionally be called after GetNetworks.
// TODO(guoweis): remove this body when chromium implements this.
virtual void GetAnyAddressNetworks(NetworkList* networks) {}
// Dumps the current list of networks in the network manager.
virtual void DumpNetworks() {}
bool GetDefaultLocalAddress(int family, IPAddress* ipaddr) const override;
struct Stats {
int ipv4_network_count;
int ipv6_network_count;
Stats() {
ipv4_network_count = 0;
ipv6_network_count = 0;
// MdnsResponderProvider interface.
webrtc::MdnsResponderInterface* GetMdnsResponder() const override;
// Base class for NetworkManager implementations.
class RTC_EXPORT NetworkManagerBase : public NetworkManager {
~NetworkManagerBase() override;
void GetNetworks(NetworkList* networks) const override;
void GetAnyAddressNetworks(NetworkList* networks) override;
EnumerationPermission enumeration_permission() const override;
bool GetDefaultLocalAddress(int family, IPAddress* ipaddr) const override;
typedef std::map<std::string, Network*> NetworkMap;
// Updates |networks_| with the networks listed in |list|. If
// |network_map_| already has a Network object for a network listed
// in the |list| then it is reused. Accept ownership of the Network
// objects in the |list|. |changed| will be set to true if there is
// any change in the network list.
void MergeNetworkList(const NetworkList& list, bool* changed);
// |stats| will be populated even if |*changed| is false.
void MergeNetworkList(const NetworkList& list,
bool* changed,
NetworkManager::Stats* stats);
void set_enumeration_permission(EnumerationPermission state) {
enumeration_permission_ = state;
void set_default_local_addresses(const IPAddress& ipv4,
const IPAddress& ipv6);
Network* GetNetworkFromAddress(const rtc::IPAddress& ip) const;
friend class NetworkTest;
EnumerationPermission enumeration_permission_;
NetworkList networks_;
NetworkMap networks_map_;
std::unique_ptr<rtc::Network> ipv4_any_address_network_;
std::unique_ptr<rtc::Network> ipv6_any_address_network_;
IPAddress default_local_ipv4_address_;
IPAddress default_local_ipv6_address_;
// We use 16 bits to save the bandwidth consumption when sending the network
// id over the Internet. It is OK that the 16-bit integer overflows to get a
// network id 0 because we only compare the network ids in the old and the new
// best connections in the transport channel.
uint16_t next_available_network_id_ = 1;
// True if calling network_preference() with a changed value
// should result in firing the SignalNetworkChanged signal.
bool signal_network_preference_change_ = false;
// Basic implementation of the NetworkManager interface that gets list
// of networks using OS APIs.
class RTC_EXPORT BasicNetworkManager : public NetworkManagerBase,
public MessageHandlerAutoCleanup,
public NetworkBinderInterface,
public sigslot::has_slots<> {
explicit BasicNetworkManager(NetworkMonitorFactory* network_monitor_factory);
~BasicNetworkManager() override;
void StartUpdating() override;
void StopUpdating() override;
void DumpNetworks() override;
// MessageHandler interface.
void OnMessage(Message* msg) override;
bool started() { return start_count_ > 0; }
// Sets the network ignore list, which is empty by default. Any network on the
// ignore list will be filtered from network enumeration results.
// Should be called only before initialization.
void set_network_ignore_list(const std::vector<std::string>& list) {
RTC_DCHECK(thread_ == nullptr);
network_ignore_list_ = list;
// Bind a socket to interface that ip address belong to.
// Implementation look up interface name and calls
// BindSocketToNetwork on NetworkMonitor.
// The interface name is needed as e.g ipv4 over ipv6 addresses
// are not exposed using Android functions, but it is possible
// bind an ipv4 address to the interface.
NetworkBindingResult BindSocketToNetwork(int socket_fd,
const IPAddress& address) override;
#if defined(WEBRTC_POSIX)
// Separated from CreateNetworks for tests.
void ConvertIfAddrs(ifaddrs* interfaces,
IfAddrsConverter* converter,
bool include_ignored,
NetworkList* networks) const RTC_RUN_ON(thread_);
#endif // defined(WEBRTC_POSIX)
// Creates a network object for each network available on the machine.
bool CreateNetworks(bool include_ignored, NetworkList* networks) const
// Determines if a network should be ignored. This should only be determined
// based on the network's property instead of any individual IP.
bool IsIgnoredNetwork(const Network& network) const RTC_RUN_ON(thread_);
// This function connects a UDP socket to a public address and returns the
// local address associated it. Since it binds to the "any" address
// internally, it returns the default local address on a multi-homed endpoint.
IPAddress QueryDefaultLocalAddress(int family) const RTC_RUN_ON(thread_);
friend class NetworkTest;
// Creates a network monitor and listens for network updates.
void StartNetworkMonitor() RTC_RUN_ON(thread_);
// Stops and removes the network monitor.
void StopNetworkMonitor() RTC_RUN_ON(thread_);
// Called when it receives updates from the network monitor.
void OnNetworksChanged();
// Updates the networks and reschedules the next update.
void UpdateNetworksContinually() RTC_RUN_ON(thread_);
// Only updates the networks; does not reschedule the next update.
void UpdateNetworksOnce() RTC_RUN_ON(thread_);
Thread* thread_ = nullptr;
bool sent_first_update_ = true;
int start_count_ = 0;
std::vector<std::string> network_ignore_list_;
NetworkMonitorFactory* network_monitor_factory_ RTC_GUARDED_BY(thread_) =
std::unique_ptr<NetworkMonitorInterface> network_monitor_
bool allow_mac_based_ipv6_ RTC_GUARDED_BY(thread_) = false;
bool bind_using_ifname_ RTC_GUARDED_BY(thread_) = false;
// Represents a Unix-type network interface, with a name and single address.
class RTC_EXPORT Network {
Network(const std::string& name,
const std::string& description,
const IPAddress& prefix,
int prefix_length);
Network(const std::string& name,
const std::string& description,
const IPAddress& prefix,
int prefix_length,
AdapterType type);
Network(const Network&);
// This signal is fired whenever type() or underlying_type_for_vpn() changes.
sigslot::signal1<const Network*> SignalTypeChanged;
// This signal is fired whenever network preference changes.
sigslot::signal1<const Network*> SignalNetworkPreferenceChanged;
const DefaultLocalAddressProvider* default_local_address_provider() {
return default_local_address_provider_;
void set_default_local_address_provider(
const DefaultLocalAddressProvider* provider) {
default_local_address_provider_ = provider;
void set_mdns_responder_provider(const MdnsResponderProvider* provider) {
mdns_responder_provider_ = provider;
// Returns the name of the interface this network is associated with.
const std::string& name() const { return name_; }
// Returns the OS-assigned name for this network. This is useful for
// debugging but should not be sent over the wire (for privacy reasons).
const std::string& description() const { return description_; }
// Returns the prefix for this network.
const IPAddress& prefix() const { return prefix_; }
// Returns the length, in bits, of this network's prefix.
int prefix_length() const { return prefix_length_; }
// |key_| has unique value per network interface. Used in sorting network
// interfaces. Key is derived from interface name and it's prefix.
std::string key() const { return key_; }
// Returns the Network's current idea of the 'best' IP it has.
// Or return an unset IP if this network has no active addresses.
// Here is the rule on how we mark the IPv6 address as ignorable for WebRTC.
// 1) return all global temporary dynamic and non-deprecated ones.
// 2) if #1 not available, return global ones.
// 3) if #2 not available, use ULA ipv6 as last resort. (ULA stands
// for unique local address, which is not route-able in open
// internet but might be useful for a close WebRTC deployment.
// TODO(guoweis): rule #3 actually won't happen at current
// implementation. The reason being that ULA address starting with
// 0xfc 0r 0xfd will be grouped into its own Network. The result of
// that is WebRTC will have one extra Network to generate candidates
// but the lack of rule #3 shouldn't prevent turning on IPv6 since
// ULA should only be tried in a close deployment anyway.
// Note that when not specifying any flag, it's treated as case global
// IPv6 address
IPAddress GetBestIP() const;
// Keep the original function here for now.
// TODO(guoweis): Remove this when all callers are migrated to GetBestIP().
IPAddress ip() const { return GetBestIP(); }
// Adds an active IP address to this network. Does not check for duplicates.
void AddIP(const InterfaceAddress& ip) { ips_.push_back(ip); }
void AddIP(const IPAddress& ip) { ips_.push_back(rtc::InterfaceAddress(ip)); }
// Sets the network's IP address list. Returns true if new IP addresses were
// detected. Passing true to already_changed skips this check.
bool SetIPs(const std::vector<InterfaceAddress>& ips, bool already_changed);
// Get the list of IP Addresses associated with this network.
const std::vector<InterfaceAddress>& GetIPs() const { return ips_; }
// Clear the network's list of addresses.
void ClearIPs() { ips_.clear(); }
// Returns the mDNS responder that can be used to obfuscate the local IP
// addresses of host candidates by mDNS names in ICE gathering. After a
// name-address mapping is created by the mDNS responder, queries for the
// created name will be resolved by the responder.
webrtc::MdnsResponderInterface* GetMdnsResponder() const;
// Returns the scope-id of the network's address.
// Should only be relevant for link-local IPv6 addresses.
int scope_id() const { return scope_id_; }
void set_scope_id(int id) { scope_id_ = id; }
// Indicates whether this network should be ignored, perhaps because
// the IP is 0, or the interface is one we know is invalid.
bool ignored() const { return ignored_; }
void set_ignored(bool ignored) { ignored_ = ignored; }
AdapterType type() const { return type_; }
// When type() is ADAPTER_TYPE_VPN, this returns the type of the underlying
// network interface used by the VPN, typically the preferred network type
// (see for example, the method setUnderlyingNetworks([])
// on
// When this information is unavailable from the OS, ADAPTER_TYPE_UNKNOWN is
// returned.
AdapterType underlying_type_for_vpn() const {
return underlying_type_for_vpn_;
void set_type(AdapterType type) {
if (type_ == type) {
type_ = type;
if (type != ADAPTER_TYPE_VPN) {
underlying_type_for_vpn_ = ADAPTER_TYPE_UNKNOWN;
void set_underlying_type_for_vpn(AdapterType type) {
if (underlying_type_for_vpn_ == type) {
underlying_type_for_vpn_ = type;
bool IsVpn() const { return type_ == ADAPTER_TYPE_VPN; }
bool IsCellular() const { return IsCellular(type_); }
static bool IsCellular(AdapterType type) {
switch (type) {
return true;
return false;
uint16_t GetCost() const;
// A unique id assigned by the network manager, which may be signaled
// to the remote side in the candidate.
uint16_t id() const { return id_; }
void set_id(uint16_t id) { id_ = id; }
int preference() const { return preference_; }
void set_preference(int preference) { preference_ = preference; }
// When we enumerate networks and find a previously-seen network is missing,
// we do not remove it (because it may be used elsewhere). Instead, we mark
// it inactive, so that we can detect network changes properly.
bool active() const { return active_; }
void set_active(bool active) {
if (active_ != active) {
active_ = active;
// Property set by operating system/firmware that has information
// about connection strength to e.g WIFI router or CELL base towers.
NetworkPreference network_preference() const { return network_preference_; }
void set_network_preference(NetworkPreference val) {
if (network_preference_ == val) {
network_preference_ = val;
// Debugging description of this network
std::string ToString() const;
const DefaultLocalAddressProvider* default_local_address_provider_ = nullptr;
const MdnsResponderProvider* mdns_responder_provider_ = nullptr;
std::string name_;
std::string description_;
IPAddress prefix_;
int prefix_length_;
std::string key_;
std::vector<InterfaceAddress> ips_;
int scope_id_;
bool ignored_;
AdapterType type_;
AdapterType underlying_type_for_vpn_ = ADAPTER_TYPE_UNKNOWN;
int preference_;
bool active_ = true;
uint16_t id_ = 0;
bool use_differentiated_cellular_costs_ = false;
NetworkPreference network_preference_ = NetworkPreference::NEUTRAL;
friend class NetworkManager;
} // namespace rtc