xref: /aosp_15_r20/external/webrtc/api/sctp_transport_interface.h (revision d9f758449e529ab9291ac668be2861e7a55c2422)
1 /*
2  *  Copyright 2019 The WebRTC project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 #ifndef API_SCTP_TRANSPORT_INTERFACE_H_
12 #define API_SCTP_TRANSPORT_INTERFACE_H_
13 
14 #include "absl/types/optional.h"
15 #include "api/dtls_transport_interface.h"
16 #include "api/rtc_error.h"
17 #include "api/scoped_refptr.h"
18 #include "rtc_base/ref_count.h"
19 
20 namespace webrtc {
21 
22 // States of a SCTP transport, corresponding to the JS API specification.
23 // http://w3c.github.io/webrtc-pc/#dom-rtcsctptransportstate
24 enum class SctpTransportState {
25   kNew,         // Has not started negotiating yet. Non-standard state.
26   kConnecting,  // In the process of negotiating an association.
27   kConnected,   // Completed negotiation of an association.
28   kClosed,      // Closed by local or remote party.
29   kNumValues
30 };
31 
32 // This object gives snapshot information about the changeable state of a
33 // SctpTransport.
34 // It reflects the readonly attributes of the object in the specification.
35 // http://w3c.github.io/webrtc-pc/#rtcsctptransport-interface
36 class RTC_EXPORT SctpTransportInformation {
37  public:
38   SctpTransportInformation() = default;
39   SctpTransportInformation(const SctpTransportInformation&) = default;
40   explicit SctpTransportInformation(SctpTransportState state);
41   SctpTransportInformation(
42       SctpTransportState state,
43       rtc::scoped_refptr<DtlsTransportInterface> dtls_transport,
44       absl::optional<double> max_message_size,
45       absl::optional<int> max_channels);
46   ~SctpTransportInformation();
47   // The DTLS transport that supports this SCTP transport.
dtls_transport()48   rtc::scoped_refptr<DtlsTransportInterface> dtls_transport() const {
49     return dtls_transport_;
50   }
state()51   SctpTransportState state() const { return state_; }
MaxMessageSize()52   absl::optional<double> MaxMessageSize() const { return max_message_size_; }
MaxChannels()53   absl::optional<int> MaxChannels() const { return max_channels_; }
54 
55  private:
56   SctpTransportState state_;
57   rtc::scoped_refptr<DtlsTransportInterface> dtls_transport_;
58   absl::optional<double> max_message_size_;
59   absl::optional<int> max_channels_;
60 };
61 
62 class SctpTransportObserverInterface {
63  public:
64   // This callback carries information about the state of the transport.
65   // The argument is a pass-by-value snapshot of the state.
66   // The callback will be called on the network thread.
67   virtual void OnStateChange(SctpTransportInformation info) = 0;
68 
69  protected:
70   virtual ~SctpTransportObserverInterface() = default;
71 };
72 
73 // A SCTP transport, as represented to the outside world.
74 // This object is created on the network thread, and can only be
75 // accessed on that thread, except for functions explicitly marked otherwise.
76 // References can be held by other threads, and destruction can therefore
77 // be initiated by other threads.
78 class SctpTransportInterface : public rtc::RefCountInterface {
79  public:
80   // This function can be called from other threads.
81   virtual rtc::scoped_refptr<DtlsTransportInterface> dtls_transport() const = 0;
82   // Returns information on the state of the SctpTransport.
83   // This function can be called from other threads.
84   virtual SctpTransportInformation Information() const = 0;
85   // Observer management.
86   virtual void RegisterObserver(SctpTransportObserverInterface* observer) = 0;
87   virtual void UnregisterObserver() = 0;
88 };
89 
90 }  // namespace webrtc
91 
92 #endif  // API_SCTP_TRANSPORT_INTERFACE_H_
93