Repo created

TMessagesProj/jni/voip/webrtc/p2p/stunprober/stun_prober.h

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+/*
+ *  Copyright 2015 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 P2P_STUNPROBER_STUN_PROBER_H_
+#define P2P_STUNPROBER_STUN_PROBER_H_
+
+#include <memory>
+#include <set>
+#include <string>
+#include <vector>
+
+#include "api/async_dns_resolver.h"
+#include "api/sequence_checker.h"
+#include "api/task_queue/pending_task_safety_flag.h"
+#include "rtc_base/network.h"
+#include "rtc_base/socket_address.h"
+#include "rtc_base/system/rtc_export.h"
+#include "rtc_base/thread.h"
+
+namespace rtc {
+class AsyncPacketSocket;
+class PacketSocketFactory;
+class Thread;
+class NetworkManager;
+class AsyncResolverInterface;
+}  // namespace rtc
+
+namespace stunprober {
+
+class StunProber;
+
+static const int kMaxUdpBufferSize = 1200;
+
+typedef std::function<void(StunProber*, int)> AsyncCallback;
+
+enum NatType {
+  NATTYPE_INVALID,
+  NATTYPE_NONE,          // Not behind a NAT.
+  NATTYPE_UNKNOWN,       // Behind a NAT but type can't be determine.
+  NATTYPE_SYMMETRIC,     // Behind a symmetric NAT.
+  NATTYPE_NON_SYMMETRIC  // Behind a non-symmetric NAT.
+};
+
+class RTC_EXPORT StunProber : public sigslot::has_slots<> {
+ public:
+  enum Status {       // Used in UMA_HISTOGRAM_ENUMERATION.
+    SUCCESS,          // Successfully received bytes from the server.
+    GENERIC_FAILURE,  // Generic failure.
+    RESOLVE_FAILED,   // Host resolution failed.
+    WRITE_FAILED,     // Sending a message to the server failed.
+    READ_FAILED,      // Reading the reply from the server failed.
+  };
+
+  class Observer {
+   public:
+    virtual ~Observer() = default;
+    virtual void OnPrepared(StunProber* prober, StunProber::Status status) = 0;
+    virtual void OnFinished(StunProber* prober, StunProber::Status status) = 0;
+  };
+
+  struct RTC_EXPORT Stats {
+    Stats();
+    ~Stats();
+
+    // `raw_num_request_sent` is the total number of requests
+    // sent. `num_request_sent` is the count of requests against a server where
+    // we see at least one response. `num_request_sent` is designed to protect
+    // against DNS resolution failure or the STUN server is not responsive
+    // which could skew the result.
+    int raw_num_request_sent = 0;
+    int num_request_sent = 0;
+
+    int num_response_received = 0;
+    NatType nat_type = NATTYPE_INVALID;
+    int average_rtt_ms = -1;
+    int success_percent = 0;
+    int target_request_interval_ns = 0;
+    int actual_request_interval_ns = 0;
+
+    // Also report whether this trial can't be considered truly as shared
+    // mode. Share mode only makes sense when we have multiple IP resolved and
+    // successfully probed.
+    bool shared_socket_mode = false;
+
+    std::string host_ip;
+
+    // If the srflx_addrs has more than 1 element, the NAT is symmetric.
+    std::set<std::string> srflx_addrs;
+  };
+
+  StunProber(rtc::PacketSocketFactory* socket_factory,
+             rtc::Thread* thread,
+             std::vector<const rtc::Network*> networks);
+  ~StunProber() override;
+
+  StunProber(const StunProber&) = delete;
+  StunProber& operator=(const StunProber&) = delete;
+
+  // Begin performing the probe test against the `servers`. If
+  // `shared_socket_mode` is false, each request will be done with a new socket.
+  // Otherwise, a unique socket will be used for a single round of requests
+  // against all resolved IPs. No single socket will be used against a given IP
+  // more than once.  The interval of requests will be as close to the requested
+  // inter-probe interval `stun_ta_interval_ms` as possible. After sending out
+  // the last scheduled request, the probe will wait `timeout_ms` for request
+  // responses and then call `finish_callback`.  `requests_per_ip` indicates how
+  // many requests should be tried for each resolved IP address. In shared mode,
+  // (the number of sockets to be created) equals to `requests_per_ip`. In
+  // non-shared mode, (the number of sockets) equals to requests_per_ip * (the
+  // number of resolved IP addresses). TODO(guoweis): Remove this once
+  // everything moved to Prepare() and Run().
+  bool Start(const std::vector<rtc::SocketAddress>& servers,
+             bool shared_socket_mode,
+             int stun_ta_interval_ms,
+             int requests_per_ip,
+             int timeout_ms,
+             AsyncCallback finish_callback);
+
+  // TODO(guoweis): The combination of Prepare() and Run() are equivalent to the
+  // Start() above. Remove Start() once everything is migrated.
+  bool Prepare(const std::vector<rtc::SocketAddress>& servers,
+               bool shared_socket_mode,
+               int stun_ta_interval_ms,
+               int requests_per_ip,
+               int timeout_ms,
+               StunProber::Observer* observer);
+
+  // Start to send out the STUN probes.
+  bool Start(StunProber::Observer* observer);
+
+  // Method to retrieve the Stats once `finish_callback` is invoked. Returning
+  // false when the result is inconclusive, for example, whether it's behind a
+  // NAT or not.
+  bool GetStats(Stats* stats) const;
+
+  int estimated_execution_time() {
+    return static_cast<int>(requests_per_ip_ * all_servers_addrs_.size() *
+                            interval_ms_);
+  }
+
+ private:
+  // A requester tracks the requests and responses from a single socket to many
+  // STUN servers.
+  class Requester;
+
+  // TODO(guoweis): Remove this once all dependencies move away from
+  // AsyncCallback.
+  class ObserverAdapter : public Observer {
+   public:
+    ObserverAdapter();
+    ~ObserverAdapter() override;
+
+    void set_callback(AsyncCallback callback) { callback_ = callback; }
+    void OnPrepared(StunProber* stunprober, Status status) override;
+    void OnFinished(StunProber* stunprober, Status status) override;
+
+   private:
+    AsyncCallback callback_;
+  };
+
+  bool ResolveServerName(const rtc::SocketAddress& addr);
+  void OnServerResolved(const webrtc::AsyncDnsResolverResult& resolver);
+
+  void OnSocketReady(rtc::AsyncPacketSocket* socket,
+                     const rtc::SocketAddress& addr);
+
+  void CreateSockets();
+
+  bool Done() {
+    return num_request_sent_ >= requests_per_ip_ * all_servers_addrs_.size();
+  }
+
+  size_t total_socket_required() {
+    return (shared_socket_mode_ ? 1 : all_servers_addrs_.size()) *
+           requests_per_ip_;
+  }
+
+  bool should_send_next_request(int64_t now);
+  int get_wake_up_interval_ms();
+
+  bool SendNextRequest();
+
+  // Will be invoked in 1ms intervals and schedule the next request from the
+  // `current_requester_` if the time has passed for another request.
+  void MaybeScheduleStunRequests();
+
+  void ReportOnPrepared(StunProber::Status status);
+  void ReportOnFinished(StunProber::Status status);
+
+  Requester* CreateRequester();
+
+  Requester* current_requester_ = nullptr;
+
+  // The time when the next request should go out.
+  int64_t next_request_time_ms_ = 0;
+
+  // Total requests sent so far.
+  uint32_t num_request_sent_ = 0;
+
+  bool shared_socket_mode_ = false;
+
+  // How many requests should be done against each resolved IP.
+  uint32_t requests_per_ip_ = 0;
+
+  // Milliseconds to pause between each STUN request.
+  int interval_ms_;
+
+  // Timeout period after the last request is sent.
+  int timeout_ms_;
+
+  // STUN server name to be resolved.
+  std::vector<rtc::SocketAddress> servers_;
+
+  // Weak references.
+  rtc::PacketSocketFactory* socket_factory_;
+  rtc::Thread* thread_;
+
+  // Accumulate all resolved addresses.
+  std::vector<rtc::SocketAddress> all_servers_addrs_;
+
+  // The set of STUN probe sockets and their state.
+  std::vector<Requester*> requesters_;
+
+  webrtc::SequenceChecker thread_checker_;
+
+  // Temporary storage for created sockets.
+  std::vector<rtc::AsyncPacketSocket*> sockets_;
+  // This tracks how many of the sockets are ready.
+  size_t total_ready_sockets_ = 0;
+
+  Observer* observer_ = nullptr;
+  // TODO(guoweis): Remove this once all dependencies move away from
+  // AsyncCallback.
+  ObserverAdapter observer_adapter_;
+
+  const std::vector<const rtc::Network*> networks_;
+  std::unique_ptr<webrtc::AsyncDnsResolverInterface> resolver_;
+
+  webrtc::ScopedTaskSafety task_safety_;
+};
+
+}  // namespace stunprober
+
+#endif  // P2P_STUNPROBER_STUN_PROBER_H_