Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1306 insertions, 0 deletions

diff --git a/third_party/libwebrtc/rtc_base/network.cc b/third_party/libwebrtc/rtc_base/network.cc
new file mode 100644
index 0000000000..4be6eed759
--- /dev/null
+++ b/third_party/libwebrtc/rtc_base/network.cc
@@ -0,0 +1,1306 @@
+/*
+ *  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 "rtc_base/network.h"
+
+#include "absl/strings/string_view.h"
+#include "rtc_base/experiments/field_trial_parser.h"
+
+#if defined(WEBRTC_POSIX)
+#include <net/if.h>
+#endif  // WEBRTC_POSIX
+
+#if defined(WEBRTC_WIN)
+#include <iphlpapi.h>
+
+#include "rtc_base/win32.h"
+#elif !defined(__native_client__)
+#include "rtc_base/ifaddrs_converter.h"
+#endif
+
+#include <memory>
+
+#include "absl/algorithm/container.h"
+#include "absl/memory/memory.h"
+#include "absl/strings/match.h"
+#include "absl/strings/string_view.h"
+#include "api/task_queue/pending_task_safety_flag.h"
+#include "api/transport/field_trial_based_config.h"
+#include "api/units/time_delta.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/logging.h"
+#include "rtc_base/memory/always_valid_pointer.h"
+#include "rtc_base/network_monitor.h"
+#include "rtc_base/socket.h"  // includes something that makes windows happy
+#include "rtc_base/string_encode.h"
+#include "rtc_base/string_utils.h"
+#include "rtc_base/strings/string_builder.h"
+#include "rtc_base/thread.h"
+
+namespace rtc {
+namespace {
+using ::webrtc::SafeTask;
+using ::webrtc::TimeDelta;
+
+// List of MAC addresses of known VPN (for windows).
+constexpr uint8_t kVpns[3][6] = {
+    // Cisco AnyConnect SSL VPN Client.
+    {0x0, 0x5, 0x9A, 0x3C, 0x7A, 0x0},
+    // Cisco AnyConnect IPSEC VPN Client.
+    {0x0, 0x5, 0x9A, 0x3C, 0x78, 0x0},
+    // GlobalProtect Virtual Ethernet.
+    {0x2, 0x50, 0x41, 0x0, 0x0, 0x1},
+};
+
+// Fetch list of networks every two seconds.
+const int kNetworksUpdateIntervalMs = 2000;
+
+const int kHighestNetworkPreference = 127;
+
+struct AddressList {
+  std::unique_ptr<Network> net;
+  std::vector<InterfaceAddress> ips;
+};
+
+bool SortNetworks(const Network* a, const Network* b) {
+  // Network types will be preferred above everything else while sorting
+  // Networks.
+
+  // Networks are sorted first by type.
+  if (a->type() != b->type()) {
+    return a->type() < b->type();
+  }
+
+  IPAddress ip_a = a->GetBestIP();
+  IPAddress ip_b = b->GetBestIP();
+
+  // After type, networks are sorted by IP address precedence values
+  // from RFC 3484-bis
+  if (IPAddressPrecedence(ip_a) != IPAddressPrecedence(ip_b)) {
+    return IPAddressPrecedence(ip_a) > IPAddressPrecedence(ip_b);
+  }
+
+  // TODO(mallinath) - Add VPN and Link speed conditions while sorting.
+
+  // Networks are sorted last by key.
+  return a->key() < b->key();
+}
+
+uint16_t ComputeNetworkCostByType(int type,
+                                  bool is_vpn,
+                                  bool use_differentiated_cellular_costs,
+                                  bool add_network_cost_to_vpn) {
+  // TODO(jonaso) : Rollout support for cellular network cost using A/B
+  // experiment to make sure it does not introduce regressions.
+  int vpnCost = (is_vpn && add_network_cost_to_vpn) ? kNetworkCostVpn : 0;
+  switch (type) {
+    case rtc::ADAPTER_TYPE_ETHERNET:
+    case rtc::ADAPTER_TYPE_LOOPBACK:
+      return kNetworkCostMin + vpnCost;
+    case rtc::ADAPTER_TYPE_WIFI:
+      return kNetworkCostLow + vpnCost;
+    case rtc::ADAPTER_TYPE_CELLULAR:
+      return kNetworkCostCellular + vpnCost;
+    case rtc::ADAPTER_TYPE_CELLULAR_2G:
+      return (use_differentiated_cellular_costs ? kNetworkCostCellular2G
+                                                : kNetworkCostCellular) +
+             vpnCost;
+    case rtc::ADAPTER_TYPE_CELLULAR_3G:
+      return (use_differentiated_cellular_costs ? kNetworkCostCellular3G
+                                                : kNetworkCostCellular) +
+             vpnCost;
+    case rtc::ADAPTER_TYPE_CELLULAR_4G:
+      return (use_differentiated_cellular_costs ? kNetworkCostCellular4G
+                                                : kNetworkCostCellular) +
+             vpnCost;
+    case rtc::ADAPTER_TYPE_CELLULAR_5G:
+      return (use_differentiated_cellular_costs ? kNetworkCostCellular5G
+                                                : kNetworkCostCellular) +
+             vpnCost;
+    case rtc::ADAPTER_TYPE_ANY:
+      // Candidates gathered from the any-address/wildcard ports, as backups,
+      // are given the maximum cost so that if there are other candidates with
+      // known interface types, we would not select candidate pairs using these
+      // backup candidates if other selection criteria with higher precedence
+      // (network conditions over the route) are the same. Note that setting the
+      // cost to kNetworkCostUnknown would be problematic since
+      // ADAPTER_TYPE_CELLULAR would then have a higher cost. See
+      // P2PTransportChannel::SortConnectionsAndUpdateState for how we rank and
+      // select candidate pairs, where the network cost is among the criteria.
+      return kNetworkCostMax + vpnCost;
+    case rtc::ADAPTER_TYPE_VPN:
+      // The cost of a VPN should be computed using its underlying network type.
+      RTC_DCHECK_NOTREACHED();
+      return kNetworkCostUnknown;
+    default:
+      return kNetworkCostUnknown + vpnCost;
+  }
+}
+
+#if !defined(__native_client__)
+bool IsIgnoredIPv6(bool allow_mac_based_ipv6, const InterfaceAddress& ip) {
+  if (ip.family() != AF_INET6) {
+    return false;
+  }
+
+  // Link-local addresses require scope id to be bound successfully.
+  // However, our IPAddress structure doesn't carry that so the
+  // information is lost and causes binding failure.
+  if (IPIsLinkLocal(ip)) {
+    RTC_LOG(LS_VERBOSE) << "Ignore link local IP:" << ip.ToSensitiveString();
+    return true;
+  }
+
+  // Any MAC based IPv6 should be avoided to prevent the MAC tracking.
+  if (IPIsMacBased(ip) && !allow_mac_based_ipv6) {
+    RTC_LOG(LS_INFO) << "Ignore Mac based IP:" << ip.ToSensitiveString();
+    return true;
+  }
+
+  // Ignore deprecated IPv6.
+  if (ip.ipv6_flags() & IPV6_ADDRESS_FLAG_DEPRECATED) {
+    RTC_LOG(LS_INFO) << "Ignore deprecated IP:" << ip.ToSensitiveString();
+    return true;
+  }
+
+  return false;
+}
+#endif  // !defined(__native_client__)
+
+// Note: consider changing to const Network* as arguments
+// if/when considering other changes that should not trigger
+// OnNetworksChanged.
+bool ShouldAdapterChangeTriggerNetworkChange(rtc::AdapterType old_type,
+                                             rtc::AdapterType new_type) {
+  // skip triggering OnNetworksChanged if
+  // changing from one cellular to another.
+  if (Network::IsCellular(old_type) && Network::IsCellular(new_type))
+    return false;
+  return true;
+}
+
+#if defined(WEBRTC_WIN)
+bool IpAddressAttributesEnabled(const webrtc::FieldTrialsView* field_trials) {
+  // Field trial key reserved in bugs.webrtc.org/14334
+  if (field_trials &&
+      field_trials->IsEnabled("WebRTC-IPv6NetworkResolutionFixes")) {
+    webrtc::FieldTrialParameter<bool> ip_address_attributes_enabled(
+        "IpAddressAttributesEnabled", false);
+    webrtc::ParseFieldTrial(
+        {&ip_address_attributes_enabled},
+        field_trials->Lookup("WebRTC-IPv6NetworkResolutionFixes"));
+    return ip_address_attributes_enabled;
+  }
+  return false;
+}
+#endif  // WEBRTC_WIN
+
+}  // namespace
+
+// These addresses are used as the targets to find out the default local address
+// on a multi-homed endpoint. They are actually DNS servers.
+const char kPublicIPv4Host[] = "8.8.8.8";
+const char kPublicIPv6Host[] = "2001:4860:4860::8888";
+const int kPublicPort = 53;  // DNS port.
+
+namespace webrtc_network_internal {
+bool CompareNetworks(const std::unique_ptr<Network>& a,
+                     const std::unique_ptr<Network>& b) {
+  if (a->prefix_length() != b->prefix_length()) {
+    return a->prefix_length() < b->prefix_length();
+  }
+  if (a->name() != b->name()) {
+    return a->name() < b->name();
+  }
+  return a->prefix() < b->prefix();
+}
+}  // namespace webrtc_network_internal
+
+std::string MakeNetworkKey(absl::string_view name,
+                           const IPAddress& prefix,
+                           int prefix_length) {
+  rtc::StringBuilder ost;
+  ost << name << "%" << prefix.ToString() << "/" << prefix_length;
+  return ost.Release();
+}
+// Test if the network name matches the type<number> pattern, e.g. eth0. The
+// matching is case-sensitive.
+bool MatchTypeNameWithIndexPattern(absl::string_view network_name,
+                                   absl::string_view type_name) {
+  if (!absl::StartsWith(network_name, type_name)) {
+    return false;
+  }
+  return absl::c_none_of(network_name.substr(type_name.size()),
+                         [](char c) { return !isdigit(c); });
+}
+
+// A cautious note that this method may not provide an accurate adapter type
+// based on the string matching. Incorrect type of adapters can affect the
+// result of the downstream network filtering, see e.g.
+// BasicPortAllocatorSession::GetNetworks when
+// PORTALLOCATOR_DISABLE_COSTLY_NETWORKS is turned on.
+AdapterType GetAdapterTypeFromName(absl::string_view network_name) {
+  if (MatchTypeNameWithIndexPattern(network_name, "lo")) {
+    // Note that we have a more robust way to determine if a network interface
+    // is a loopback interface by checking the flag IFF_LOOPBACK in ifa_flags of
+    // an ifaddr struct. See ConvertIfAddrs in this file.
+    return ADAPTER_TYPE_LOOPBACK;
+  }
+
+  if (MatchTypeNameWithIndexPattern(network_name, "eth")) {
+    return ADAPTER_TYPE_ETHERNET;
+  }
+
+  if (MatchTypeNameWithIndexPattern(network_name, "wlan") ||
+      MatchTypeNameWithIndexPattern(network_name, "v4-wlan")) {
+    return ADAPTER_TYPE_WIFI;
+  }
+
+  if (MatchTypeNameWithIndexPattern(network_name, "ipsec") ||
+      MatchTypeNameWithIndexPattern(network_name, "tun") ||
+      MatchTypeNameWithIndexPattern(network_name, "utun") ||
+      MatchTypeNameWithIndexPattern(network_name, "tap")) {
+    return ADAPTER_TYPE_VPN;
+  }
+#if defined(WEBRTC_IOS)
+  // Cell networks are pdp_ipN on iOS.
+  if (MatchTypeNameWithIndexPattern(network_name, "pdp_ip")) {
+    return ADAPTER_TYPE_CELLULAR;
+  }
+  if (MatchTypeNameWithIndexPattern(network_name, "en")) {
+    // This may not be most accurate because sometimes Ethernet interface
+    // name also starts with "en" but it is better than showing it as
+    // "unknown" type.
+    // TODO(honghaiz): Write a proper IOS network manager.
+    return ADAPTER_TYPE_WIFI;
+  }
+#elif defined(WEBRTC_ANDROID)
+  if (MatchTypeNameWithIndexPattern(network_name, "rmnet") ||
+      MatchTypeNameWithIndexPattern(network_name, "rmnet_data") ||
+      MatchTypeNameWithIndexPattern(network_name, "v4-rmnet") ||
+      MatchTypeNameWithIndexPattern(network_name, "v4-rmnet_data") ||
+      MatchTypeNameWithIndexPattern(network_name, "clat") ||
+      MatchTypeNameWithIndexPattern(network_name, "ccmni")) {
+    return ADAPTER_TYPE_CELLULAR;
+  }
+#endif
+
+  return ADAPTER_TYPE_UNKNOWN;
+}
+
+NetworkManager::EnumerationPermission NetworkManager::enumeration_permission()
+    const {
+  return ENUMERATION_ALLOWED;
+}
+
+bool NetworkManager::GetDefaultLocalAddress(int family, IPAddress* addr) const {
+  return false;
+}
+
+webrtc::MdnsResponderInterface* NetworkManager::GetMdnsResponder() const {
+  return nullptr;
+}
+
+NetworkManagerBase::NetworkManagerBase(
+    const webrtc::FieldTrialsView* field_trials)
+    : field_trials_(field_trials),
+      enumeration_permission_(NetworkManager::ENUMERATION_ALLOWED),
+      signal_network_preference_change_(
+          field_trials
+              ? field_trials->IsEnabled("WebRTC-SignalNetworkPreferenceChange")
+              : false) {}
+
+NetworkManager::EnumerationPermission
+NetworkManagerBase::enumeration_permission() const {
+  return enumeration_permission_;
+}
+
+std::unique_ptr<Network> NetworkManagerBase::CreateNetwork(
+    absl::string_view name,
+    absl::string_view description,
+    const IPAddress& prefix,
+    int prefix_length,
+    AdapterType type) const {
+  return std::make_unique<Network>(name, description, prefix, prefix_length,
+                                   type);
+}
+
+std::vector<const Network*> NetworkManagerBase::GetAnyAddressNetworks() {
+  std::vector<const Network*> networks;
+  if (!ipv4_any_address_network_) {
+    const rtc::IPAddress ipv4_any_address(INADDR_ANY);
+    ipv4_any_address_network_ =
+        CreateNetwork("any", "any", ipv4_any_address, 0, ADAPTER_TYPE_ANY);
+    ipv4_any_address_network_->set_default_local_address_provider(this);
+    ipv4_any_address_network_->set_mdns_responder_provider(this);
+    ipv4_any_address_network_->AddIP(ipv4_any_address);
+  }
+  networks.push_back(ipv4_any_address_network_.get());
+
+  if (!ipv6_any_address_network_) {
+    const rtc::IPAddress ipv6_any_address(in6addr_any);
+    ipv6_any_address_network_ =
+        CreateNetwork("any", "any", ipv6_any_address, 0, ADAPTER_TYPE_ANY);
+    ipv6_any_address_network_->set_default_local_address_provider(this);
+    ipv6_any_address_network_->set_mdns_responder_provider(this);
+    ipv6_any_address_network_->AddIP(ipv6_any_address);
+  }
+  networks.push_back(ipv6_any_address_network_.get());
+  return networks;
+}
+
+std::vector<const Network*> NetworkManagerBase::GetNetworks() const {
+  std::vector<const Network*> result;
+  result.insert(result.begin(), networks_.begin(), networks_.end());
+  return result;
+}
+
+void NetworkManagerBase::MergeNetworkList(
+    std::vector<std::unique_ptr<Network>> new_networks,
+    bool* changed) {
+  NetworkManager::Stats stats;
+  MergeNetworkList(std::move(new_networks), changed, &stats);
+}
+
+void NetworkManagerBase::MergeNetworkList(
+    std::vector<std::unique_ptr<Network>> new_networks,
+    bool* changed,
+    NetworkManager::Stats* stats) {
+  *changed = false;
+  // AddressList in this map will track IP addresses for all Networks
+  // with the same key.
+  std::map<std::string, AddressList> consolidated_address_list;
+  absl::c_sort(new_networks, rtc::webrtc_network_internal::CompareNetworks);
+  // First, build a set of network-keys to the ipaddresses.
+  for (auto& network : new_networks) {
+    bool might_add_to_merged_list = false;
+    std::string key = MakeNetworkKey(network->name(), network->prefix(),
+                                     network->prefix_length());
+    const std::vector<InterfaceAddress>& addresses = network->GetIPs();
+    if (consolidated_address_list.find(key) ==
+        consolidated_address_list.end()) {
+      AddressList addrlist;
+      addrlist.net = std::move(network);
+      consolidated_address_list[key] = std::move(addrlist);
+      might_add_to_merged_list = true;
+    }
+    AddressList& current_list = consolidated_address_list[key];
+    for (const InterfaceAddress& address : addresses) {
+      current_list.ips.push_back(address);
+    }
+    if (might_add_to_merged_list) {
+      if (current_list.ips[0].family() == AF_INET) {
+        stats->ipv4_network_count++;
+      } else {
+        RTC_DCHECK(current_list.ips[0].family() == AF_INET6);
+        stats->ipv6_network_count++;
+      }
+    }
+  }
+
+  // Next, look for existing network objects to re-use.
+  // Result of Network merge. Element in this list should have unique key.
+  std::vector<Network*> merged_list;
+  for (auto& kv : consolidated_address_list) {
+    const std::string& key = kv.first;
+    std::unique_ptr<Network> net = std::move(kv.second.net);
+    auto existing = networks_map_.find(key);
+    if (existing == networks_map_.end()) {
+      // This network is new.
+      net->set_id(next_available_network_id_++);
+      // We might have accumulated IPAddresses from the first
+      // step, set it here.
+      net->SetIPs(kv.second.ips, true);
+      // Place it in the network map.
+      merged_list.push_back(net.get());
+      networks_map_[key] = std::move(net);
+      *changed = true;
+    } else {
+      // This network exists in the map already. Reset its IP addresses.
+      Network* existing_net = existing->second.get();
+      *changed = existing_net->SetIPs(kv.second.ips, *changed);
+      merged_list.push_back(existing_net);
+      if (net->type() != ADAPTER_TYPE_UNKNOWN &&
+          net->type() != existing_net->type()) {
+        if (ShouldAdapterChangeTriggerNetworkChange(existing_net->type(),
+                                                    net->type())) {
+          *changed = true;
+        }
+        existing_net->set_type(net->type());
+      }
+      // If the existing network was not active, networks have changed.
+      if (!existing_net->active()) {
+        *changed = true;
+      }
+      if (net->network_preference() != existing_net->network_preference()) {
+        existing_net->set_network_preference(net->network_preference());
+        if (signal_network_preference_change_) {
+          *changed = true;
+        }
+      }
+      RTC_DCHECK(net->active());
+    }
+    networks_map_[key]->set_mdns_responder_provider(this);
+  }
+  // It may still happen that the merged list is a subset of `networks_`.
+  // To detect this change, we compare their sizes.
+  if (merged_list.size() != networks_.size()) {
+    *changed = true;
+  }
+
+  // If the network list changes, we re-assign `networks_` to the merged list
+  // and re-sort it.
+  if (*changed) {
+    networks_ = merged_list;
+    // Reset the active states of all networks.
+    for (const auto& kv : networks_map_) {
+      const std::unique_ptr<Network>& network = kv.second;
+      // If `network` is in the newly generated `networks_`, it is active.
+      bool found = absl::c_linear_search(networks_, network.get());
+      network->set_active(found);
+    }
+    absl::c_sort(networks_, SortNetworks);
+    // Now network interfaces are sorted, we should set the preference value
+    // for each of the interfaces we are planning to use.
+    // Preference order of network interfaces might have changed from previous
+    // sorting due to addition of higher preference network interface.
+    // Since we have already sorted the network interfaces based on our
+    // requirements, we will just assign a preference value starting with 127,
+    // in decreasing order.
+    int pref = kHighestNetworkPreference;
+    for (Network* network : networks_) {
+      network->set_preference(pref);
+      if (pref > 0) {
+        --pref;
+      } else {
+        RTC_LOG(LS_ERROR) << "Too many network interfaces to handle!";
+        break;
+      }
+    }
+  }
+}
+
+void NetworkManagerBase::set_default_local_addresses(const IPAddress& ipv4,
+                                                     const IPAddress& ipv6) {
+  if (ipv4.family() == AF_INET) {
+    default_local_ipv4_address_ = ipv4;
+  }
+  if (ipv6.family() == AF_INET6) {
+    default_local_ipv6_address_ = ipv6;
+  }
+}
+
+bool NetworkManagerBase::GetDefaultLocalAddress(int family,
+                                                IPAddress* ipaddr) const {
+  if (family == AF_INET && !default_local_ipv4_address_.IsNil()) {
+    *ipaddr = default_local_ipv4_address_;
+    return true;
+  } else if (family == AF_INET6 && !default_local_ipv6_address_.IsNil()) {
+    Network* ipv6_network = GetNetworkFromAddress(default_local_ipv6_address_);
+    if (ipv6_network) {
+      // If the default ipv6 network's BestIP is different than
+      // default_local_ipv6_address_, use it instead.
+      // This is to prevent potential IP address leakage. See WebRTC bug 5376.
+      *ipaddr = ipv6_network->GetBestIP();
+    } else {
+      *ipaddr = default_local_ipv6_address_;
+    }
+    return true;
+  }
+  return false;
+}
+
+Network* NetworkManagerBase::GetNetworkFromAddress(
+    const rtc::IPAddress& ip) const {
+  for (Network* network : networks_) {
+    const auto& ips = network->GetIPs();
+    if (absl::c_any_of(ips, [&](const InterfaceAddress& existing_ip) {
+          return ip == static_cast<rtc::IPAddress>(existing_ip);
+        })) {
+      return network;
+    }
+  }
+  return nullptr;
+}
+
+bool NetworkManagerBase::IsVpnMacAddress(
+    rtc::ArrayView<const uint8_t> address) {
+  if (address.data() == nullptr && address.size() == 0) {
+    return false;
+  }
+  for (const auto& vpn : kVpns) {
+    if (sizeof(vpn) == address.size() &&
+        memcmp(vpn, address.data(), address.size()) == 0) {
+      return true;
+    }
+  }
+  return false;
+}
+
+BasicNetworkManager::BasicNetworkManager(
+    NetworkMonitorFactory* network_monitor_factory,
+    SocketFactory* socket_factory,
+    const webrtc::FieldTrialsView* field_trials_view)
+    : NetworkManagerBase(field_trials_view),
+      field_trials_(field_trials_view),
+      network_monitor_factory_(network_monitor_factory),
+      socket_factory_(socket_factory),
+      allow_mac_based_ipv6_(
+          field_trials()->IsEnabled("WebRTC-AllowMACBasedIPv6")),
+      bind_using_ifname_(
+          !field_trials()->IsDisabled("WebRTC-BindUsingInterfaceName")) {
+  RTC_DCHECK(socket_factory_);
+}
+
+BasicNetworkManager::~BasicNetworkManager() {
+  if (task_safety_flag_) {
+    task_safety_flag_->SetNotAlive();
+  }
+}
+
+void BasicNetworkManager::OnNetworksChanged() {
+  RTC_DCHECK_RUN_ON(thread_);
+  RTC_LOG(LS_INFO) << "Network change was observed";
+  UpdateNetworksOnce();
+}
+
+#if defined(__native_client__)
+
+bool BasicNetworkManager::CreateNetworks(
+    bool include_ignored,
+    std::vector<std::unique_ptr<Network>>* networks) const {
+  RTC_DCHECK_NOTREACHED();
+  RTC_LOG(LS_WARNING) << "BasicNetworkManager doesn't work on NaCl yet";
+  return false;
+}
+
+#elif defined(WEBRTC_POSIX)
+NetworkMonitorInterface::InterfaceInfo BasicNetworkManager::GetInterfaceInfo(
+    struct ifaddrs* cursor) const {
+  if (cursor->ifa_flags & IFF_LOOPBACK) {
+    return {
+        .adapter_type = ADAPTER_TYPE_LOOPBACK,
+        .underlying_type_for_vpn = ADAPTER_TYPE_UNKNOWN,
+        .network_preference = NetworkPreference::NEUTRAL,
+        .available = true,
+    };
+  } else if (network_monitor_) {
+    return network_monitor_->GetInterfaceInfo(cursor->ifa_name);
+  } else {
+    return {.adapter_type = GetAdapterTypeFromName(cursor->ifa_name),
+            .underlying_type_for_vpn = ADAPTER_TYPE_UNKNOWN,
+            .network_preference = NetworkPreference::NEUTRAL,
+            .available = true};
+  }
+}
+
+void BasicNetworkManager::ConvertIfAddrs(
+    struct ifaddrs* interfaces,
+    IfAddrsConverter* ifaddrs_converter,
+    bool include_ignored,
+    std::vector<std::unique_ptr<Network>>* networks) const {
+  std::map<std::string, Network*> current_networks;
+
+  for (struct ifaddrs* cursor = interfaces; cursor != nullptr;
+       cursor = cursor->ifa_next) {
+    IPAddress prefix;
+    IPAddress mask;
+    InterfaceAddress ip;
+    int scope_id = 0;
+
+    // Some interfaces may not have address assigned.
+    if (!cursor->ifa_addr || !cursor->ifa_netmask) {
+      continue;
+    }
+    // Skip unknown family.
+    if (cursor->ifa_addr->sa_family != AF_INET &&
+        cursor->ifa_addr->sa_family != AF_INET6) {
+      continue;
+    }
+    // Convert to InterfaceAddress.
+    // TODO(webrtc:13114): Convert ConvertIfAddrs to use rtc::Netmask.
+    if (!ifaddrs_converter->ConvertIfAddrsToIPAddress(cursor, &ip, &mask)) {
+      continue;
+    }
+    // Skip ones which are down.
+    if (!(cursor->ifa_flags & IFF_RUNNING)) {
+      RTC_LOG(LS_INFO) << "Skip interface because of not IFF_RUNNING: "
+                       << ip.ToSensitiveString();
+      continue;
+    }
+
+    // Special case for IPv6 address.
+    if (cursor->ifa_addr->sa_family == AF_INET6) {
+      if (IsIgnoredIPv6(allow_mac_based_ipv6_, ip)) {
+        continue;
+      }
+      scope_id =
+          reinterpret_cast<sockaddr_in6*>(cursor->ifa_addr)->sin6_scope_id;
+    }
+
+    int prefix_length = CountIPMaskBits(mask);
+    prefix = TruncateIP(ip, prefix_length);
+    std::string key =
+        MakeNetworkKey(std::string(cursor->ifa_name), prefix, prefix_length);
+
+    auto iter = current_networks.find(key);
+    if (iter != current_networks.end()) {
+      // We have already added this network, simply add extra IP.
+      iter->second->AddIP(ip);
+#if RTC_DCHECK_IS_ON
+      // Validate that different IP of same network has same properties
+      auto existing_network = iter->second;
+
+      NetworkMonitorInterface::InterfaceInfo if_info = GetInterfaceInfo(cursor);
+      if (if_info.adapter_type != ADAPTER_TYPE_VPN &&
+          IsConfiguredVpn(prefix, prefix_length)) {
+        if_info.underlying_type_for_vpn = if_info.adapter_type;
+        if_info.adapter_type = ADAPTER_TYPE_VPN;
+      }
+
+      RTC_DCHECK(existing_network->type() == if_info.adapter_type);
+      RTC_DCHECK(existing_network->underlying_type_for_vpn() ==
+                 if_info.underlying_type_for_vpn);
+      RTC_DCHECK(existing_network->network_preference() ==
+                 if_info.network_preference);
+      if (!if_info.available) {
+        RTC_DCHECK(existing_network->ignored());
+      }
+#endif  // RTC_DCHECK_IS_ON
+      continue;
+    }
+
+    // Create a new network.
+    NetworkMonitorInterface::InterfaceInfo if_info = GetInterfaceInfo(cursor);
+
+    // Check manually configured VPN override.
+    if (if_info.adapter_type != ADAPTER_TYPE_VPN &&
+        IsConfiguredVpn(prefix, prefix_length)) {
+      if_info.underlying_type_for_vpn = if_info.adapter_type;
+      if_info.adapter_type = ADAPTER_TYPE_VPN;
+    }
+
+    auto network = CreateNetwork(cursor->ifa_name, cursor->ifa_name, prefix,
+                                 prefix_length, if_info.adapter_type);
+    network->set_default_local_address_provider(this);
+    network->set_scope_id(scope_id);
+    network->AddIP(ip);
+    if (!if_info.available) {
+      network->set_ignored(true);
+    } else {
+      network->set_ignored(IsIgnoredNetwork(*network));
+    }
+    network->set_underlying_type_for_vpn(if_info.underlying_type_for_vpn);
+    network->set_network_preference(if_info.network_preference);
+    if (include_ignored || !network->ignored()) {
+      current_networks[key] = network.get();
+      networks->push_back(std::move(network));
+    }
+  }
+}
+
+bool BasicNetworkManager::CreateNetworks(
+    bool include_ignored,
+    std::vector<std::unique_ptr<Network>>* networks) const {
+  struct ifaddrs* interfaces;
+  int error = getifaddrs(&interfaces);
+  if (error != 0) {
+    RTC_LOG_ERR(LS_ERROR) << "getifaddrs failed to gather interface data: "
+                          << error;
+    return false;
+  }
+
+  std::unique_ptr<IfAddrsConverter> ifaddrs_converter(CreateIfAddrsConverter());
+  ConvertIfAddrs(interfaces, ifaddrs_converter.get(), include_ignored,
+                 networks);
+
+  freeifaddrs(interfaces);
+  return true;
+}
+
+#elif defined(WEBRTC_WIN)
+
+unsigned int GetPrefix(PIP_ADAPTER_PREFIX prefixlist,
+                       const IPAddress& ip,
+                       IPAddress* prefix) {
+  IPAddress current_prefix;
+  IPAddress best_prefix;
+  unsigned int best_length = 0;
+  while (prefixlist) {
+    // Look for the longest matching prefix in the prefixlist.
+    if (prefixlist->Address.lpSockaddr == nullptr ||
+        prefixlist->Address.lpSockaddr->sa_family != ip.family()) {
+      prefixlist = prefixlist->Next;
+      continue;
+    }
+    switch (prefixlist->Address.lpSockaddr->sa_family) {
+      case AF_INET: {
+        sockaddr_in* v4_addr =
+            reinterpret_cast<sockaddr_in*>(prefixlist->Address.lpSockaddr);
+        current_prefix = IPAddress(v4_addr->sin_addr);
+        break;
+      }
+      case AF_INET6: {
+        sockaddr_in6* v6_addr =
+            reinterpret_cast<sockaddr_in6*>(prefixlist->Address.lpSockaddr);
+        current_prefix = IPAddress(v6_addr->sin6_addr);
+        break;
+      }
+      default: {
+        prefixlist = prefixlist->Next;
+        continue;
+      }
+    }
+    if (TruncateIP(ip, prefixlist->PrefixLength) == current_prefix &&
+        prefixlist->PrefixLength > best_length) {
+      best_prefix = current_prefix;
+      best_length = prefixlist->PrefixLength;
+    }
+    prefixlist = prefixlist->Next;
+  }
+  *prefix = best_prefix;
+  return best_length;
+}
+
+bool BasicNetworkManager::CreateNetworks(
+    bool include_ignored,
+    std::vector<std::unique_ptr<Network>>* networks) const {
+  std::map<std::string, Network*> current_networks;
+  // MSDN recommends a 15KB buffer for the first try at GetAdaptersAddresses.
+  size_t buffer_size = 16384;
+  std::unique_ptr<char[]> adapter_info(new char[buffer_size]);
+  PIP_ADAPTER_ADDRESSES adapter_addrs =
+      reinterpret_cast<PIP_ADAPTER_ADDRESSES>(adapter_info.get());
+  int adapter_flags = (GAA_FLAG_SKIP_DNS_SERVER | GAA_FLAG_SKIP_ANYCAST |
+                       GAA_FLAG_SKIP_MULTICAST | GAA_FLAG_INCLUDE_PREFIX);
+  int ret = 0;
+  do {
+    adapter_info.reset(new char[buffer_size]);
+    adapter_addrs = reinterpret_cast<PIP_ADAPTER_ADDRESSES>(adapter_info.get());
+    ret = GetAdaptersAddresses(AF_UNSPEC, adapter_flags, 0, adapter_addrs,
+                               reinterpret_cast<PULONG>(&buffer_size));
+  } while (ret == ERROR_BUFFER_OVERFLOW);
+  if (ret != ERROR_SUCCESS) {
+    return false;
+  }
+  int count = 0;
+  while (adapter_addrs) {
+    if (adapter_addrs->OperStatus == IfOperStatusUp) {
+      PIP_ADAPTER_UNICAST_ADDRESS address = adapter_addrs->FirstUnicastAddress;
+      PIP_ADAPTER_PREFIX prefixlist = adapter_addrs->FirstPrefix;
+      std::string description = ToUtf8(adapter_addrs->Description,
+                                       wcslen(adapter_addrs->Description));
+
+      for (; address; address = address->Next) {
+        std::string name = rtc::ToString(count);
+#if !defined(NDEBUG)
+        name = ToUtf8(adapter_addrs->FriendlyName,
+                      wcslen(adapter_addrs->FriendlyName));
+#endif
+
+        IPAddress ip;
+        int scope_id = 0;
+        std::unique_ptr<Network> network;
+        switch (address->Address.lpSockaddr->sa_family) {
+          case AF_INET: {
+            sockaddr_in* v4_addr =
+                reinterpret_cast<sockaddr_in*>(address->Address.lpSockaddr);
+            ip = IPAddress(v4_addr->sin_addr);
+            break;
+          }
+          case AF_INET6: {
+            sockaddr_in6* v6_addr =
+                reinterpret_cast<sockaddr_in6*>(address->Address.lpSockaddr);
+            scope_id = v6_addr->sin6_scope_id;
+
+            // From http://technet.microsoft.com/en-us/ff568768(v=vs.60).aspx,
+            // the way to identify a temporary IPv6 Address is to check if
+            // PrefixOrigin is equal to IpPrefixOriginRouterAdvertisement and
+            // SuffixOrigin equal to IpSuffixOriginRandom.
+            int ip_address_attributes = IPV6_ADDRESS_FLAG_NONE;
+            if (IpAddressAttributesEnabled(field_trials_.get())) {
+              if (address->PrefixOrigin == IpPrefixOriginRouterAdvertisement &&
+                  address->SuffixOrigin == IpSuffixOriginRandom) {
+                ip_address_attributes |= IPV6_ADDRESS_FLAG_TEMPORARY;
+              }
+              if (address->PreferredLifetime == 0) {
+                ip_address_attributes |= IPV6_ADDRESS_FLAG_DEPRECATED;
+              }
+            }
+            if (IsIgnoredIPv6(allow_mac_based_ipv6_,
+                              InterfaceAddress(v6_addr->sin6_addr,
+                                               ip_address_attributes))) {
+              continue;
+            }
+            ip = InterfaceAddress(v6_addr->sin6_addr, ip_address_attributes);
+            break;
+          }
+          default: {
+            continue;
+          }
+        }
+
+        IPAddress prefix;
+        int prefix_length = GetPrefix(prefixlist, ip, &prefix);
+        std::string key = MakeNetworkKey(name, prefix, prefix_length);
+        auto existing_network = current_networks.find(key);
+        if (existing_network == current_networks.end()) {
+          AdapterType adapter_type = ADAPTER_TYPE_UNKNOWN;
+          switch (adapter_addrs->IfType) {
+            case IF_TYPE_SOFTWARE_LOOPBACK:
+              adapter_type = ADAPTER_TYPE_LOOPBACK;
+              break;
+            case IF_TYPE_ETHERNET_CSMACD:
+            case IF_TYPE_ETHERNET_3MBIT:
+            case IF_TYPE_IEEE80212:
+            case IF_TYPE_FASTETHER:
+            case IF_TYPE_FASTETHER_FX:
+            case IF_TYPE_GIGABITETHERNET:
+              adapter_type = ADAPTER_TYPE_ETHERNET;
+              break;
+            case IF_TYPE_IEEE80211:
+              adapter_type = ADAPTER_TYPE_WIFI;
+              break;
+            case IF_TYPE_WWANPP:
+            case IF_TYPE_WWANPP2:
+              adapter_type = ADAPTER_TYPE_CELLULAR;
+              break;
+            default:
+              // TODO(phoglund): Need to recognize other types as well.
+              adapter_type = ADAPTER_TYPE_UNKNOWN;
+              break;
+          }
+          auto underlying_type_for_vpn = ADAPTER_TYPE_UNKNOWN;
+          if (adapter_type != ADAPTER_TYPE_VPN &&
+              IsConfiguredVpn(prefix, prefix_length)) {
+            underlying_type_for_vpn = adapter_type;
+            adapter_type = ADAPTER_TYPE_VPN;
+          }
+          if (adapter_type != ADAPTER_TYPE_VPN &&
+              IsVpnMacAddress(rtc::ArrayView<const uint8_t>(
+                  reinterpret_cast<const uint8_t*>(
+                      adapter_addrs->PhysicalAddress),
+                  adapter_addrs->PhysicalAddressLength))) {
+            // With MAC-based detection we do not know the
+            // underlying adapter type.
+            underlying_type_for_vpn = ADAPTER_TYPE_UNKNOWN;
+            adapter_type = ADAPTER_TYPE_VPN;
+          }
+
+          auto network = CreateNetwork(name, description, prefix, prefix_length,
+                                       adapter_type);
+          network->set_underlying_type_for_vpn(underlying_type_for_vpn);
+          network->set_default_local_address_provider(this);
+          network->set_mdns_responder_provider(this);
+          network->set_scope_id(scope_id);
+          network->AddIP(ip);
+          bool ignored = IsIgnoredNetwork(*network);
+          network->set_ignored(ignored);
+          if (include_ignored || !network->ignored()) {
+            current_networks[key] = network.get();
+            networks->push_back(std::move(network));
+          }
+        } else {
+          (*existing_network).second->AddIP(ip);
+        }
+      }
+      // Count is per-adapter - all 'Networks' created from the same
+      // adapter need to have the same name.
+      ++count;
+    }
+    adapter_addrs = adapter_addrs->Next;
+  }
+  return true;
+}
+#endif  // WEBRTC_WIN
+
+bool BasicNetworkManager::IsIgnoredNetwork(const Network& network) const {
+  // Ignore networks on the explicit ignore list.
+  for (const std::string& ignored_name : network_ignore_list_) {
+    if (network.name() == ignored_name) {
+      return true;
+    }
+  }
+
+#if defined(WEBRTC_POSIX)
+  // Filter out VMware/VirtualBox interfaces, typically named vmnet1,
+  // vmnet8, or vboxnet0.
+  if (strncmp(network.name().c_str(), "vmnet", 5) == 0 ||
+      strncmp(network.name().c_str(), "vnic", 4) == 0 ||
+      strncmp(network.name().c_str(), "vboxnet", 7) == 0) {
+    return true;
+  }
+#elif defined(WEBRTC_WIN)
+  // Ignore any HOST side vmware adapters with a description like:
+  // VMware Virtual Ethernet Adapter for VMnet1
+  // but don't ignore any GUEST side adapters with a description like:
+  // VMware Accelerated AMD PCNet Adapter #2
+  if (strstr(network.description().c_str(), "VMnet") != nullptr) {
+    return true;
+  }
+#endif
+
+  // Ignore any networks with a 0.x.y.z IP
+  if (network.prefix().family() == AF_INET) {
+    return (network.prefix().v4AddressAsHostOrderInteger() < 0x01000000);
+  }
+
+  return false;
+}
+
+void BasicNetworkManager::StartUpdating() {
+  thread_ = Thread::Current();
+  // Redundant but necessary for thread annotations.
+  RTC_DCHECK_RUN_ON(thread_);
+  if (start_count_) {
+    // If network interfaces are already discovered and signal is sent,
+    // we should trigger network signal immediately for the new clients
+    // to start allocating ports.
+    if (sent_first_update_)
+      thread_->PostTask(SafeTask(task_safety_flag_, [this] {
+        RTC_DCHECK_RUN_ON(thread_);
+        SignalNetworksChanged();
+      }));
+  } else {
+    RTC_DCHECK(task_safety_flag_ == nullptr);
+    task_safety_flag_ = webrtc::PendingTaskSafetyFlag::Create();
+    thread_->PostTask(SafeTask(task_safety_flag_, [this] {
+      RTC_DCHECK_RUN_ON(thread_);
+      UpdateNetworksContinually();
+    }));
+    StartNetworkMonitor();
+  }
+  ++start_count_;
+}
+
+void BasicNetworkManager::StopUpdating() {
+  RTC_DCHECK_RUN_ON(thread_);
+  if (!start_count_)
+    return;
+
+  --start_count_;
+  if (!start_count_) {
+    task_safety_flag_->SetNotAlive();
+    task_safety_flag_ = nullptr;
+    sent_first_update_ = false;
+    StopNetworkMonitor();
+  }
+}
+
+void BasicNetworkManager::StartNetworkMonitor() {
+  if (network_monitor_factory_ == nullptr) {
+    return;
+  }
+  if (!network_monitor_) {
+    network_monitor_.reset(
+        network_monitor_factory_->CreateNetworkMonitor(*field_trials()));
+    if (!network_monitor_) {
+      return;
+    }
+    network_monitor_->SetNetworksChangedCallback(
+        [this]() { OnNetworksChanged(); });
+  }
+
+  if (network_monitor_->SupportsBindSocketToNetwork()) {
+    // Set NetworkBinder on SocketServer so that
+    // PhysicalSocket::Bind will call
+    // BasicNetworkManager::BindSocketToNetwork(), (that will lookup interface
+    // name and then call network_monitor_->BindSocketToNetwork()).
+    thread_->socketserver()->set_network_binder(this);
+  }
+
+  network_monitor_->Start();
+}
+
+void BasicNetworkManager::StopNetworkMonitor() {
+  if (!network_monitor_) {
+    return;
+  }
+  network_monitor_->Stop();
+
+  if (network_monitor_->SupportsBindSocketToNetwork()) {
+    // Reset NetworkBinder on SocketServer.
+    if (thread_->socketserver()->network_binder() == this) {
+      thread_->socketserver()->set_network_binder(nullptr);
+    }
+  }
+}
+
+IPAddress BasicNetworkManager::QueryDefaultLocalAddress(int family) const {
+  RTC_DCHECK(family == AF_INET || family == AF_INET6);
+
+  std::unique_ptr<Socket> socket(
+      socket_factory_->CreateSocket(family, SOCK_DGRAM));
+  if (!socket) {
+    RTC_LOG_ERR(LS_ERROR) << "Socket creation failed";
+    return IPAddress();
+  }
+
+  if (socket->Connect(SocketAddress(
+          family == AF_INET ? kPublicIPv4Host : kPublicIPv6Host, kPublicPort)) <
+      0) {
+    if (socket->GetError() != ENETUNREACH &&
+        socket->GetError() != EHOSTUNREACH) {
+      // Ignore the expected case of "host/net unreachable" - which happens if
+      // the network is V4- or V6-only.
+      RTC_LOG(LS_INFO) << "Connect failed with " << socket->GetError();
+    }
+    return IPAddress();
+  }
+  return socket->GetLocalAddress().ipaddr();
+}
+
+void BasicNetworkManager::UpdateNetworksOnce() {
+  if (!start_count_)
+    return;
+
+  std::vector<std::unique_ptr<Network>> list;
+  if (!CreateNetworks(false, &list)) {
+    SignalError();
+  } else {
+    bool changed;
+    NetworkManager::Stats stats;
+    MergeNetworkList(std::move(list), &changed, &stats);
+    set_default_local_addresses(QueryDefaultLocalAddress(AF_INET),
+                                QueryDefaultLocalAddress(AF_INET6));
+    if (changed || !sent_first_update_) {
+      SignalNetworksChanged();
+      sent_first_update_ = true;
+    }
+  }
+}
+
+void BasicNetworkManager::UpdateNetworksContinually() {
+  UpdateNetworksOnce();
+  thread_->PostDelayedTask(SafeTask(task_safety_flag_,
+                                    [this] {
+                                      RTC_DCHECK_RUN_ON(thread_);
+                                      UpdateNetworksContinually();
+                                    }),
+                           TimeDelta::Millis(kNetworksUpdateIntervalMs));
+}
+
+void BasicNetworkManager::DumpNetworks() {
+  RTC_DCHECK_RUN_ON(thread_);
+  std::vector<const Network*> list = GetNetworks();
+  RTC_LOG(LS_INFO) << "NetworkManager detected " << list.size() << " networks:";
+  for (const Network* network : list) {
+    RTC_LOG(LS_INFO) << network->ToString() << ": " << network->description()
+                     << ", active ? " << network->active()
+                     << ((network->ignored()) ? ", Ignored" : "");
+  }
+}
+
+NetworkBindingResult BasicNetworkManager::BindSocketToNetwork(
+    int socket_fd,
+    const IPAddress& address) {
+  RTC_DCHECK_RUN_ON(thread_);
+  std::string if_name;
+  if (bind_using_ifname_) {
+    Network* net = GetNetworkFromAddress(address);
+    if (net != nullptr) {
+      if_name = net->name();
+    }
+  }
+  return network_monitor_->BindSocketToNetwork(socket_fd, address, if_name);
+}
+
+Network::Network(absl::string_view name,
+                 absl::string_view desc,
+                 const IPAddress& prefix,
+                 int prefix_length,
+                 AdapterType type)
+    : name_(name),
+      description_(desc),
+      prefix_(prefix),
+      prefix_length_(prefix_length),
+      key_(MakeNetworkKey(name, prefix, prefix_length)),
+      scope_id_(0),
+      ignored_(false),
+      type_(type),
+      preference_(0) {}
+
+Network::Network(const Network&) = default;
+
+Network::~Network() = default;
+
+// Sets the addresses of this network. Returns true if the address set changed.
+// Change detection is short circuited if the changed argument is true.
+bool Network::SetIPs(const std::vector<InterfaceAddress>& ips, bool changed) {
+  // Detect changes with a nested loop; n-squared but we expect on the order
+  // of 2-3 addresses per network.
+  changed = changed || ips.size() != ips_.size();
+  if (!changed) {
+    for (const InterfaceAddress& ip : ips) {
+      if (!absl::c_linear_search(ips_, ip)) {
+        changed = true;
+        break;
+      }
+    }
+  }
+
+  ips_ = ips;
+  return changed;
+}
+
+// Select the best IP address to use from this Network.
+IPAddress Network::GetBestIP() const {
+  if (ips_.size() == 0) {
+    return IPAddress();
+  }
+
+  if (prefix_.family() == AF_INET) {
+    return static_cast<IPAddress>(ips_.at(0));
+  }
+
+  InterfaceAddress selected_ip, link_local_ip, ula_ip;
+
+  for (const InterfaceAddress& ip : ips_) {
+    // Ignore any address which has been deprecated already.
+    if (ip.ipv6_flags() & IPV6_ADDRESS_FLAG_DEPRECATED)
+      continue;
+
+    if (IPIsLinkLocal(ip)) {
+      link_local_ip = ip;
+      continue;
+    }
+
+    // ULA address should only be returned when we have no other
+    // global IP.
+    if (IPIsULA(static_cast<const IPAddress&>(ip))) {
+      ula_ip = ip;
+      continue;
+    }
+    selected_ip = ip;
+
+    // Search could stop once a temporary non-deprecated one is found.
+    if (ip.ipv6_flags() & IPV6_ADDRESS_FLAG_TEMPORARY)
+      break;
+  }
+
+  if (IPIsUnspec(selected_ip)) {
+    if (!IPIsUnspec(link_local_ip)) {
+      // No proper global IPv6 address found, use link local address instead.
+      selected_ip = link_local_ip;
+    } else if (!IPIsUnspec(ula_ip)) {
+      // No proper global and link local address found, use ULA instead.
+      selected_ip = ula_ip;
+    }
+  }
+
+  return static_cast<IPAddress>(selected_ip);
+}
+
+webrtc::MdnsResponderInterface* Network::GetMdnsResponder() const {
+  if (mdns_responder_provider_ == nullptr) {
+    return nullptr;
+  }
+  return mdns_responder_provider_->GetMdnsResponder();
+}
+
+uint16_t Network::GetCost(const webrtc::FieldTrialsView* field_trials) const {
+  return GetCost(
+      *webrtc::AlwaysValidPointer<const webrtc::FieldTrialsView,
+                                  webrtc::FieldTrialBasedConfig>(field_trials));
+}
+
+uint16_t Network::GetCost(const webrtc::FieldTrialsView& field_trials) const {
+  AdapterType type = IsVpn() ? underlying_type_for_vpn_ : type_;
+  const bool use_differentiated_cellular_costs =
+      field_trials.IsEnabled("WebRTC-UseDifferentiatedCellularCosts");
+  const bool add_network_cost_to_vpn =
+      field_trials.IsEnabled("WebRTC-AddNetworkCostToVpn");
+  return ComputeNetworkCostByType(type, IsVpn(),
+                                  use_differentiated_cellular_costs,
+                                  add_network_cost_to_vpn);
+}
+
+// This is the inverse of ComputeNetworkCostByType().
+std::pair<rtc::AdapterType, bool /* vpn */>
+Network::GuessAdapterFromNetworkCost(int network_cost) {
+  switch (network_cost) {
+    case kNetworkCostMin:
+      return {rtc::ADAPTER_TYPE_ETHERNET, false};
+    case kNetworkCostMin + kNetworkCostVpn:
+      return {rtc::ADAPTER_TYPE_ETHERNET, true};
+    case kNetworkCostLow:
+      return {rtc::ADAPTER_TYPE_WIFI, false};
+    case kNetworkCostLow + kNetworkCostVpn:
+      return {rtc::ADAPTER_TYPE_WIFI, true};
+    case kNetworkCostCellular:
+      return {rtc::ADAPTER_TYPE_CELLULAR, false};
+    case kNetworkCostCellular + kNetworkCostVpn:
+      return {rtc::ADAPTER_TYPE_CELLULAR, true};
+    case kNetworkCostCellular2G:
+      return {rtc::ADAPTER_TYPE_CELLULAR_2G, false};
+    case kNetworkCostCellular2G + kNetworkCostVpn:
+      return {rtc::ADAPTER_TYPE_CELLULAR_2G, true};
+    case kNetworkCostCellular3G:
+      return {rtc::ADAPTER_TYPE_CELLULAR_3G, false};
+    case kNetworkCostCellular3G + kNetworkCostVpn:
+      return {rtc::ADAPTER_TYPE_CELLULAR_3G, true};
+    case kNetworkCostCellular4G:
+      return {rtc::ADAPTER_TYPE_CELLULAR_4G, false};
+    case kNetworkCostCellular4G + kNetworkCostVpn:
+      return {rtc::ADAPTER_TYPE_CELLULAR_4G, true};
+    case kNetworkCostCellular5G:
+      return {rtc::ADAPTER_TYPE_CELLULAR_5G, false};
+    case kNetworkCostCellular5G + kNetworkCostVpn:
+      return {rtc::ADAPTER_TYPE_CELLULAR_5G, true};
+    case kNetworkCostUnknown:
+      return {rtc::ADAPTER_TYPE_UNKNOWN, false};
+    case kNetworkCostUnknown + kNetworkCostVpn:
+      return {rtc::ADAPTER_TYPE_UNKNOWN, true};
+    case kNetworkCostMax:
+      return {rtc::ADAPTER_TYPE_ANY, false};
+    case kNetworkCostMax + kNetworkCostVpn:
+      return {rtc::ADAPTER_TYPE_ANY, true};
+  }
+  RTC_LOG(LS_VERBOSE) << "Unknown network cost: " << network_cost;
+  return {rtc::ADAPTER_TYPE_UNKNOWN, false};
+}
+
+std::string Network::ToString() const {
+  rtc::StringBuilder ss;
+  // Print out the first space-terminated token of the network desc, plus
+  // the IP address.
+  ss << "Net[" << description_.substr(0, description_.find(' ')) << ":"
+     << prefix_.ToSensitiveString() << "/" << prefix_length_ << ":"
+     << AdapterTypeToString(type_);
+  if (IsVpn()) {
+    ss << "/" << AdapterTypeToString(underlying_type_for_vpn_);
+  }
+  ss << ":id=" << id_ << "]";
+  return ss.Release();
+}
+
+void BasicNetworkManager::set_vpn_list(const std::vector<NetworkMask>& vpn) {
+  if (thread_ == nullptr) {
+    vpn_ = vpn;
+  } else {
+    thread_->BlockingCall([this, vpn] { vpn_ = vpn; });
+  }
+}
+
+bool BasicNetworkManager::IsConfiguredVpn(IPAddress prefix,
+                                          int prefix_length) const {
+  RTC_DCHECK_RUN_ON(thread_);
+  for (const auto& vpn : vpn_) {
+    if (prefix_length >= vpn.prefix_length()) {
+      auto copy = TruncateIP(prefix, vpn.prefix_length());
+      if (copy == vpn.address()) {
+        return true;
+      }
+    }
+  }
+  return false;
+}
+
+}  // namespace rtc