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/*
* 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.
*/
#ifndef RTC_BASE_NETWORK_H_
#define RTC_BASE_NETWORK_H_
#include <stdint.h>
#include <deque>
#include <map>
#include <memory>
#include <string>
#include <vector>
#include "absl/base/attributes.h"
#include "absl/strings/string_view.h"
#include "api/array_view.h"
#include "api/field_trials_view.h"
#include "api/sequence_checker.h"
#include "api/task_queue/pending_task_safety_flag.h"
#include "api/transport/field_trial_based_config.h"
#include "rtc_base/ip_address.h"
#include "rtc_base/mdns_responder_interface.h"
#include "rtc_base/memory/always_valid_pointer.h"
#include "rtc_base/network_monitor.h"
#include "rtc_base/network_monitor_factory.h"
#include "rtc_base/socket_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;
namespace webrtc_network_internal {
bool CompareNetworks(const std::unique_ptr<Network>& a,
const std::unique_ptr<Network>& b);
} // namespace webrtc_network_internal
// 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(absl::string_view 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(absl::string_view network_name);
class DefaultLocalAddressProvider {
public:
virtual ~DefaultLocalAddressProvider() = default;
// The default local address is the local address used in multi-homed endpoint
// when the any address (0.0.0.0 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 {
public:
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;
};
// Network/mask in CIDR representation.
class NetworkMask {
public:
NetworkMask(const IPAddress& addr, int prefix_length)
: address_(addr), prefix_length_(prefix_length) {}
const IPAddress& address() const { return address_; }
int prefix_length() const { return prefix_length_; }
bool operator==(const NetworkMask& o) const {
return address_ == o.address_ && prefix_length_ == o.prefix_length_;
}
private:
IPAddress address_;
// Length of valid bits in address_ (for ipv4 valid range is 0-32)
int prefix_length_;
};
// 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 {
public:
// 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.
};
// 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.
// The returned vector of Network* is valid as long as the NetworkManager is
// alive.
virtual std::vector<const Network*> GetNetworks() 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.
virtual std::vector<const Network*> GetAnyAddressNetworks() = 0;
// 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;
virtual void set_vpn_list(const std::vector<NetworkMask>& vpn) {}
};
// Represents a Unix-type network interface, with a name and single address.
class RTC_EXPORT Network {
public:
Network(absl::string_view name,
absl::string_view description,
const IPAddress& prefix,
int prefix_length)
: Network(name,
description,
prefix,
prefix_length,
rtc::ADAPTER_TYPE_UNKNOWN) {}
Network(absl::string_view name,
absl::string_view description,
const IPAddress& prefix,
int prefix_length,
AdapterType type);
Network(const Network&);
~Network();
// This signal is fired whenever type() or underlying_type_for_vpn() changes.
// Mutable, to support connecting on the const Network passed to cricket::Port
// constructor.
mutable sigslot::signal1<const Network*> SignalTypeChanged;
// This signal is fired whenever network preference changes.
sigslot::signal1<const Network*> SignalNetworkPreferenceChanged;
const DefaultLocalAddressProvider* default_local_address_provider() const {
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_; }
// Returns the family for the network prefix.
int family() const { return prefix_.family(); }
// `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, return local link ones.
// 4) if #3 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;
// 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(android.net.Network[])
// on https://developer.android.com/reference/android/net/VpnService.html).
// 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) {
return;
}
type_ = type;
if (type != ADAPTER_TYPE_VPN) {
underlying_type_for_vpn_ = ADAPTER_TYPE_UNKNOWN;
}
SignalTypeChanged(this);
}
void set_underlying_type_for_vpn(AdapterType type) {
if (underlying_type_for_vpn_ == type) {
return;
}
underlying_type_for_vpn_ = type;
SignalTypeChanged(this);
}
bool IsVpn() const { return type_ == ADAPTER_TYPE_VPN; }
bool IsCellular() const { return IsCellular(type_); }
static bool IsCellular(AdapterType type) {
switch (type) {
case ADAPTER_TYPE_CELLULAR:
case ADAPTER_TYPE_CELLULAR_2G:
case ADAPTER_TYPE_CELLULAR_3G:
case ADAPTER_TYPE_CELLULAR_4G:
case ADAPTER_TYPE_CELLULAR_5G:
return true;
default:
return false;
}
}
// Note: This function is called "rarely".
// Twice per Network in BasicPortAllocator if
// PORTALLOCATOR_DISABLE_COSTLY_NETWORKS. Once in Port::Construct() (and when
// Port::OnNetworkTypeChanged is called).
uint16_t GetCost(const webrtc::FieldTrialsView& field_trials) 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) {
return;
}
network_preference_ = val;
SignalNetworkPreferenceChanged(this);
}
static std::pair<rtc::AdapterType, bool /* vpn */>
GuessAdapterFromNetworkCost(int network_cost);
// Debugging description of this network
std::string ToString() const;
private:
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;
NetworkPreference network_preference_ = NetworkPreference::NEUTRAL;
friend class NetworkManager;
};
// Base class for NetworkManager implementations.
class RTC_EXPORT NetworkManagerBase : public NetworkManager {
public:
NetworkManagerBase();
std::vector<const Network*> GetNetworks() const override;
std::vector<const Network*> GetAnyAddressNetworks() override;
EnumerationPermission enumeration_permission() const override;
bool GetDefaultLocalAddress(int family, IPAddress* ipaddr) const override;
// Check if MAC address in |bytes| is one of the pre-defined
// MAC addresses for know VPNs.
static bool IsVpnMacAddress(rtc::ArrayView<const uint8_t> address);
protected:
// Updates `networks_` with the networks listed in `list`. If
// `networks_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(std::vector<std::unique_ptr<Network>> list,
bool* changed);
// `stats` will be populated even if |*changed| is false.
void MergeNetworkList(std::vector<std::unique_ptr<Network>> 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;
// To enable subclasses to get the networks list, without interfering with
// refactoring of the interface GetNetworks method.
const std::vector<Network*>& GetNetworksInternal() const { return networks_; }
std::unique_ptr<Network> CreateNetwork(absl::string_view name,
absl::string_view description,
const IPAddress& prefix,
int prefix_length,
AdapterType type) const;
private:
friend class NetworkTest;
EnumerationPermission enumeration_permission_;
std::vector<Network*> networks_;
std::map<std::string, std::unique_ptr<Network>> 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;
};
// Basic implementation of the NetworkManager interface that gets list
// of networks using OS APIs.
class RTC_EXPORT BasicNetworkManager : public NetworkManagerBase,
public NetworkBinderInterface,
public sigslot::has_slots<> {
public:
// This is used by lots of downstream code.
BasicNetworkManager(SocketFactory* socket_factory,
const webrtc::FieldTrialsView* field_trials = nullptr)
: BasicNetworkManager(/* network_monitor_factory= */ nullptr,
socket_factory,
field_trials) {}
BasicNetworkManager(NetworkMonitorFactory* network_monitor_factory,
SocketFactory* socket_factory,
const webrtc::FieldTrialsView* field_trials = nullptr);
~BasicNetworkManager() override;
void StartUpdating() override;
void StopUpdating() override;
void DumpNetworks() 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;
}
// Set a list of manually configured VPN's.
void set_vpn_list(const std::vector<NetworkMask>& vpn) override;
// Check if |prefix| is configured as VPN.
bool IsConfiguredVpn(IPAddress prefix, int prefix_length) const;
// 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;
protected:
#if defined(WEBRTC_POSIX)
// Separated from CreateNetworks for tests.
void ConvertIfAddrs(ifaddrs* interfaces,
IfAddrsConverter* converter,
bool include_ignored,
std::vector<std::unique_ptr<Network>>* networks) const
RTC_RUN_ON(thread_);
NetworkMonitorInterface::InterfaceInfo GetInterfaceInfo(
struct ifaddrs* cursor) 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,
std::vector<std::unique_ptr<Network>>* networks) const
RTC_RUN_ON(thread_);
// 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_);
private:
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;
webrtc::AlwaysValidPointer<const webrtc::FieldTrialsView,
webrtc::FieldTrialBasedConfig>
field_trials_;
std::vector<std::string> network_ignore_list_;
NetworkMonitorFactory* const network_monitor_factory_;
SocketFactory* const socket_factory_;
std::unique_ptr<NetworkMonitorInterface> network_monitor_
RTC_GUARDED_BY(thread_);
bool allow_mac_based_ipv6_ RTC_GUARDED_BY(thread_) = false;
bool bind_using_ifname_ RTC_GUARDED_BY(thread_) = false;
std::vector<NetworkMask> vpn_;
rtc::scoped_refptr<webrtc::PendingTaskSafetyFlag> task_safety_flag_;
};
} // namespace rtc
#endif // RTC_BASE_NETWORK_H_