text: /*
   *  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 "p2p/base/port_allocator.h"
  
  #include <iterator>
  #include <set>
  #include <utility>
  
  #include "p2p/base/ice_credentials_iterator.h"
  #include "rtc_base/checks.h"
  #include "rtc_base/logging.h"
  
  namespace cricket {
  
  RelayServerConfig::RelayServerConfig() {}
  
  RelayServerConfig::RelayServerConfig(const rtc::SocketAddress& address,
                                       const std::string& username,
                                       const std::string& password,
                                       ProtocolType proto)
      : credentials(username, password) {
    ports.push_back(ProtocolAddress(address, proto));
  }
  
  RelayServerConfig::RelayServerConfig(const std::string& address,
                                       int port,
                                       const std::string& username,
                                       const std::string& password,
                                       ProtocolType proto)
      : RelayServerConfig(rtc::SocketAddress(address, port),
                          username,
                          password,
                          proto) {}
  
  // Legacy constructor where "secure" and PROTO_TCP implies PROTO_TLS.
  RelayServerConfig::RelayServerConfig(const std::string& address,
                                       int port,
                                       const std::string& username,
                                       const std::string& password,
                                       ProtocolType proto,
                                       bool secure)
      : RelayServerConfig(address,
                          port,
                          username,
                          password,
                          (proto == PROTO_TCP && secure ? PROTO_TLS : proto)) {}
  
  RelayServerConfig::RelayServerConfig(const RelayServerConfig&) = default;
  
  RelayServerConfig::~RelayServerConfig() = default;
  
  PortAllocatorSession::PortAllocatorSession(const std::string& content_name,
                                             int component,
                                             const std::string& ice_ufrag,
                                             const std::string& ice_pwd,
                                             const std::string& network_token,
                                             uint32_t flags)
      : flags_(flags),
        generation_(0),
        content_name_(content_name),
        component_(component),
        ice_ufrag_(ice_ufrag),
        ice_pwd_(ice_pwd),
        network_token_(network_token) {
    // Pooled sessions are allowed to be created with empty content name,
    // component, ufrag and password.
    RTC_DCHECK(ice_ufrag.empty() == ice_pwd.empty());
  }
  
  PortAllocatorSession::~PortAllocatorSession() = default;
  
  bool PortAllocatorSession::IsCleared() const {
    return false;
  }
  
  bool PortAllocatorSession::IsStopped() const {
    return false;
  }
  
  uint32_t PortAllocatorSession::generation() {
    return generation_;
  }
  
  void PortAllocatorSession::set_generation(uint32_t generation) {
    generation_ = generation;
  }
  
  PortAllocator::PortAllocator()
      : flags_(kDefaultPortAllocatorFlags),
        min_port_(0),
        max_port_(0),
        max_ipv6_networks_(kDefaultMaxIPv6Networks),
        step_delay_(kDefaultStepDelay),
        allow_tcp_listen_(true),
        candidate_filter_(CF_ALL) {
    // The allocator will be attached to a thread in Initialize.
    thread_checker_.Detach();
  }
  
  void PortAllocator::Initialize() {
    RTC_DCHECK(thread_checker_.IsCurrent());
    initialized_ = true;
  }
  
  PortAllocator::~PortAllocator() {
    CheckRunOnValidThreadIfInitialized();
  }
  
  void PortAllocator::set_restrict_ice_credentials_change(bool value) {
    restrict_ice_credentials_change_ = value;
  }
  
  // Deprecated
  bool PortAllocator::SetConfiguration(
      const ServerAddresses& stun_servers,
      const std::vector<RelayServerConfig>& turn_servers,
      int candidate_pool_size,
      bool prune_turn_ports,
      webrtc::TurnCustomizer* turn_customizer,
      const absl::optional<int>& stun_candidate_keepalive_interval) {
    webrtc::PortPrunePolicy turn_port_prune_policy =
        prune_turn_ports ? webrtc::PRUNE_BASED_ON_PRIORITY : webrtc::NO_PRUNE;
    return SetConfiguration(stun_servers, turn_servers, candidate_pool_size,
                            turn_port_prune_policy, turn_customizer,
                            stun_candidate_keepalive_interval, std::string());
  }
  
  bool PortAllocator::SetConfiguration(
      const ServerAddresses& stun_servers,
      const std::vector<RelayServerConfig>& turn_servers,
      int candidate_pool_size,
      webrtc::PortPrunePolicy turn_port_prune_policy,
      webrtc::TurnCustomizer* turn_customizer,
      const absl::optional<int>& stun_candidate_keepalive_interval,
      const std::string& network_token) {
    CheckRunOnValidThreadIfInitialized();
    // A positive candidate pool size would lead to the creation of a pooled
    // allocator session and starting getting ports, which we should only do on
    // the network thread.
    RTC_DCHECK(candidate_pool_size == 0 || thread_checker_.IsCurrent());
    bool ice_servers_changed =
        (stun_servers != stun_servers_ || turn_servers != turn_servers_);
    stun_servers_ = stun_servers;
    turn_servers_ = turn_servers;
    turn_port_prune_policy_ = turn_port_prune_policy;
    network_token_ = network_token;
  
    if (candidate_pool_frozen_) {
      if (candidate_pool_size != candidate_pool_size_) {
        RTC_LOG(LS_ERROR)
            << "Trying to change candidate pool size after pool was frozen.";
        return false;
      }
      return true;
    }
  
    if (candidate_pool_size < 0) {
      RTC_LOG(LS_ERROR) << "Can't set negative pool size.";
      return false;
    }
  
    candidate_pool_size_ = candidate_pool_size;
  
    // If ICE servers changed, throw away any existing pooled sessions and create
    // new ones.
    if (ice_servers_changed) {
      pooled_sessions_.clear();
    }
  
    turn_customizer_ = turn_customizer;
  
    // If |candidate_pool_size_| is less than the number of pooled sessions, get
    // rid of the extras.
    while (candidate_pool_size_ < static_cast<int>(pooled_sessions_.size())) {
      pooled_sessions_.back().reset(nullptr);
      pooled_sessions_.pop_back();
    }
  
    // |stun_candidate_keepalive_interval_| will be used in STUN port allocation
    // in future sessions. We also update the ready ports in the pooled sessions.
    // Ports in sessions that are taken and owned by P2PTransportChannel will be
    // updated there via IceConfig.
    stun_candidate_keepalive_interval_ = stun_candidate_keepalive_interval;
    for (const auto& session : pooled_sessions_) {
      session->SetStunKeepaliveIntervalForReadyPorts(
          stun_candidate_keepalive_interval_);
    }
  
    // If |candidate_pool_size_| is greater than the number of pooled sessions,
    // create new sessions.
    while (static_cast<int>(pooled_sessions_.size()) < candidate_pool_size_) {
      IceParameters iceCredentials =
          IceCredentialsIterator::CreateRandomIceCredentials();
      PortAllocatorSession* pooled_session =
          CreateSessionInternal("", 0, iceCredentials.ufrag, iceCredentials.pwd);
      pooled_session->set_pooled(true);
      pooled_session->StartGettingPorts();
      pooled_sessions_.push_back(
          std::unique_ptr<PortAllocatorSession>(pooled_session));
    }
    return true;
  }
  
  std::unique_ptr<PortAllocatorSession> PortAllocator::CreateSession(
      const std::string& content_name,
      int component,
      const std::string& ice_ufrag,
      const std::string& ice_pwd) {
    CheckRunOnValidThreadAndInitialized();
    auto session = std::unique_ptr<PortAllocatorSession>(
        CreateSessionInternal(content_name, component, ice_ufrag, ice_pwd));
    session->SetCandidateFilter(candidate_filter());
    return session;
  }
  
  std::unique_ptr<PortAllocatorSession> PortAllocator::TakePooledSession(
      const std::string& content_name,
      int component,
      const std::string& ice_ufrag,
      const std::string& ice_pwd) {
    CheckRunOnValidThreadAndInitialized();
    RTC_DCHECK(!ice_ufrag.empty());
    RTC_DCHECK(!ice_pwd.empty());
    if (pooled_sessions_.empty()) {
      return nullptr;
    }
  
    IceParameters credentials(ice_ufrag, ice_pwd, false);
    // If restrict_ice_credentials_change_ is TRUE, then call FindPooledSession
    // with ice credentials. Otherwise call it with nullptr which means
    // "find any" pooled session.
    auto cit = FindPooledSession(restrict_ice_credentials_change_ ? &credentials
                                                                  : nullptr);
    if (cit == pooled_sessions_.end()) {
      return nullptr;
    }
  
    auto it =
        pooled_sessions_.begin() + std::distance(pooled_sessions_.cbegin(), cit);
    std::unique_ptr<PortAllocatorSession> ret = std::move(*it);
    ret->SetIceParameters(content_name, component, ice_ufrag, ice_pwd);
    ret->set_pooled(false);
    // According to JSEP, a pooled session should filter candidates only
    // after it's taken out of the pool.
    ret->SetCandidateFilter(candidate_filter());
    pooled_sessions_.erase(it);
    return ret;
  }
  
  const PortAllocatorSession* PortAllocator::GetPooledSession(
      const IceParameters* ice_credentials) const {
    CheckRunOnValidThreadAndInitialized();
    auto it = FindPooledSession(ice_credentials);
    if (it == pooled_sessions_.end()) {
      return nullptr;
    } else {
      return it->get();
    }
  }
  
  std::vector<std::unique_ptr<PortAllocatorSession>>::const_iterator
  PortAllocator::FindPooledSession(const IceParameters* ice_credentials) const {
    for (auto it = pooled_sessions_.begin(); it != pooled_sessions_.end(); ++it) {
      if (ice_credentials == nullptr ||
          ((*it)->ice_ufrag() == ice_credentials->ufrag &&
           (*it)->ice_pwd() == ice_credentials->pwd &&
           (*it)->network_token() == network_token_)) {
        return it;
      }
    }
    return pooled_sessions_.end();
  }
  
  void PortAllocator::FreezeCandidatePool() {
    CheckRunOnValidThreadAndInitialized();
    candidate_pool_frozen_ = true;
  }
  
  void PortAllocator::DiscardCandidatePool() {
    CheckRunOnValidThreadIfInitialized();
    pooled_sessions_.clear();
  }
  
  void PortAllocator::SetCandidateFilter(uint32_t filter) {
    CheckRunOnValidThreadIfInitialized();
    if (candidate_filter_ == filter) {
      return;
    }
    uint32_t prev_filter = candidate_filter_;
    candidate_filter_ = filter;
    SignalCandidateFilterChanged(prev_filter, filter);
  }
  
  void PortAllocator::GetCandidateStatsFromPooledSessions(
      CandidateStatsList* candidate_stats_list) {
    CheckRunOnValidThreadAndInitialized();
    for (const auto& session : pooled_sessions()) {
      session->GetCandidateStatsFromReadyPorts(candidate_stats_list);
    }
  }
  
  std::vector<IceParameters> PortAllocator::GetPooledIceCredentials() {
    CheckRunOnValidThreadAndInitialized();
    std::vector<IceParameters> list;
    for (const auto& session : pooled_sessions_) {
      list.push_back(
          IceParameters(session->ice_ufrag(), session->ice_pwd(), false));
    }
    return list;
  }
  
  Candidate PortAllocator::SanitizeCandidate(const Candidate& c) const {
    CheckRunOnValidThreadAndInitialized();
    // For a local host candidate, we need to conceal its IP address candidate if
    // the mDNS obfuscation is enabled.
    bool use_hostname_address =
        c.type() == LOCAL_PORT_TYPE && MdnsObfuscationEnabled();
    // If adapter enumeration is disabled or host candidates are disabled,
    // clear the raddr of STUN candidates to avoid local address leakage.
    bool filter_stun_related_address =
        ((flags() & PORTALLOCATOR_DISABLE_ADAPTER_ENUMERATION) &&
         (flags() & PORTALLOCATOR_DISABLE_DEFAULT_LOCAL_CANDIDATE)) ||
        !(candidate_filter_ & CF_HOST) || MdnsObfuscationEnabled();
    // If the candidate filter doesn't allow reflexive addresses, empty TURN raddr
    // to avoid reflexive address leakage.
    bool filter_turn_related_address = !(candidate_filter_ & CF_REFLEXIVE);
    bool filter_related_address =
        ((c.type() == STUN_PORT_TYPE && filter_stun_related_address) ||
         (c.type() == RELAY_PORT_TYPE && filter_turn_related_address));
    return c.ToSanitizedCopy(use_hostname_address, filter_related_address);
  }
  
  }  // namespace cricket
  