Add get_stats

Author: mickel8

lib/ex_webrtc/app.ex

@@ -0,0 +1,10 @@
+defmodule ExWebRTC.App do
+  @moduledoc false
+  use Application
+
+  @impl true
+  def start(_type, _args) do
+    children = [{Registry, keys: :unique, name: ExWebRTC.Registry}]
+    Supervisor.start_link(children, strategy: :one_for_one)
+  end
+end

lib/ex_webrtc/dtls_transport.ex

@@ -33,6 +33,19 @@ defmodule ExWebRTC.DTLSTransport do
   """
   @type dtls_state() :: :new | :connecting | :connected | :closed | :failed
 
+  @typedoc """
+  Information about DTLS certificate.
+
+  * `fingerprint` - hex dump of the cert fingerprint
+  * `fingerprint_algorithm` - always `:sha_256`
+  * `base64_certificate` - base 64 encoded certificate
+  """
+  @type cert_info :: %{
+          fingerprint: binary(),
+          fingerprint_algorithm: :sha_256,
+          base64_certificate: binary()
+        }
+
   @spec start_link(ICETransport.t(), pid()) :: GenServer.on_start()
   def start_link(ice_transport \\ DefaultICETransport, ice_pid) do
     behaviour = ice_transport.__info__(:attributes)[:behaviour] || []
@@ -49,6 +62,14 @@ defmodule ExWebRTC.DTLSTransport do
     GenServer.call(dtls_transport, :set_ice_connected)
   end
 
+  @spec get_certs_info(dtls_transport()) :: %{
+          local_cert_info: cert_info(),
+          remote_cert_info: cert_info() | nil
+        }
+  def get_certs_info(dtls_transport) do
+    GenServer.call(dtls_transport, :get_certs_info)
+  end
+
   @spec get_fingerprint(dtls_transport()) :: binary()
   def get_fingerprint(dtls_transport) do
     GenServer.call(dtls_transport, :get_fingerprint)
@@ -87,8 +108,12 @@ defmodule ExWebRTC.DTLSTransport do
       ice_connected: false,
       buffered_packets: nil,
       cert: cert,
+      base64_cert: Base.encode64(cert),
       pkey: pkey,
       fingerprint: fingerprint,
+      remote_cert: nil,
+      remote_base64_cert: nil,
+      remote_fingerprint: nil,
       in_srtp: ExLibSRTP.new(),
       out_srtp: ExLibSRTP.new(),
       # sha256 hex dump
@@ -133,6 +158,49 @@ defmodule ExWebRTC.DTLSTransport do
     end
   end
 
+  @impl true
+  def handle_call(:get_certs_info, _from, state) do
+    local_cert_info = %{
+      fingerprint: Utils.hex_dump(state.fingerprint),
+      fingerprint_algorithm: :sha_256,
+      base64_certificate: state.base64_cert
+    }
+
+    remote_cert_info =
+      if state.dtls_state == :connected do
+        %{
+          fingerprint: Utils.hex_dump(state.remote_fingerprint),
+          fingerprint_algorithm: :sha_256,
+          base64_certificate: state.remote_base64_cert
+        }
+      else
+        nil
+      end
+
+    certs_info = %{
+      local_cert_info: local_cert_info,
+      remote_cert_info: remote_cert_info
+    }
+
+    {:reply, certs_info, state}
+  end
+
+  @impl true
+  def handle_call(:get_remote_cert_info, _from, %{dtls_state: :connected} = state) do
+    cert_info = %{
+      fingerprint: state.remote_fingerprint,
+      fingerprint_algorithm: :sha_256,
+      base64_certificate: state.remote_base64_cert
+    }
+
+    {:reply, cert_info, state}
+  end
+
+  @impl true
+  def handle_call(:get_remote_cert_info, _from, state) do
+    {:reply, nil, state}
+  end
+
   @impl true
   def handle_call(:get_fingerprint, _from, state) do
     {:reply, state.fingerprint, state}
@@ -247,6 +315,7 @@ defmodule ExWebRTC.DTLSTransport do
 
       {:handshake_finished, lkm, rkm, profile, packets} ->
         Logger.debug("DTLS handshake finished")
+        state = update_remote_cert_info(state)
         state.ice_transport.send_data(state.ice_pid, packets)
 
         peer_fingerprint =
@@ -269,6 +338,7 @@ defmodule ExWebRTC.DTLSTransport do
         Logger.debug("DTLS handshake finished")
         :ok = setup_srtp(state, lkm, rkm, profile)
         state = update_dtls_state(state, :connected)
+        state = update_remote_cert_info(state)
         {:ok, state}
 
       :handshake_want_read ->
@@ -340,5 +410,13 @@ defmodule ExWebRTC.DTLSTransport do
     %{state | dtls_state: new_dtls_state}
   end
 
+  defp update_remote_cert_info(state) do
+    cert = ExDTLS.get_cert(state.dtls)
+    fingerprint = ExDTLS.get_cert_fingerprint(cert)
+    base64_cert = Base.encode64(cert)
+
+    %{state | remote_cert: cert, remote_base64_cert: base64_cert, remote_fingerprint: fingerprint}
+  end
+
   defp notify(dst, msg), do: send(dst, {:dtls_transport, self(), msg})
 end

lib/ex_webrtc/ice_transport.ex

@@ -14,6 +14,7 @@ defmodule ExWebRTC.ICETransport do
   @callback restart(pid()) :: :ok
   @callback send_data(pid(), binary()) :: :ok
   @callback set_remote_credentials(pid(), ufrag :: binary(), pwd :: binary()) :: :ok
+  @callback get_stats(pid()) :: map()
   @callback stop(pid()) :: :ok
 end
 
@@ -43,5 +44,7 @@ defmodule ExWebRTC.DefaultICETransport do
   @impl true
   defdelegate set_remote_credentials(pid, ufrag, pwd), to: ICEAgent
   @impl true
+  defdelegate get_stats(pid), to: ICEAgent
+  @impl true
   defdelegate stop(pid), to: ICEAgent
 end

lib/ex_webrtc/peer_connection.ex

@@ -18,6 +18,7 @@ defmodule ExWebRTC.PeerConnection do
     MediaStreamTrack,
     RTPTransceiver,
     RTPSender,
+    RTPReceiver,
     SDPUtils,
     SessionDescription,
     Utils
@@ -59,6 +60,11 @@ defmodule ExWebRTC.PeerConnection do
   @type connection_state() :: :closed | :failed | :disconnected | :new | :connecting | :connected
 
   #### API ####
+  @spec get_all_peer_connections() :: [pid()]
+  def get_all_peer_connections() do
+    Registry.select(ExWebRTC.Registry, [{{:_, :"$1", :_}, [], [:"$1"]}])
+  end
+
   @spec start_link(Configuration.options()) :: GenServer.on_start()
   def start_link(options \\ []) do
     configuration = Configuration.from_options!(options)
@@ -157,6 +163,11 @@ defmodule ExWebRTC.PeerConnection do
     GenServer.call(peer_connection, {:remove_track, sender_id})
   end
 
+  @spec get_stats(peer_connection()) :: %{String.t() => term()}
+  def get_stats(peer_connection) do
+    GenServer.call(peer_connection, :get_stats)
+  end
+
   @spec send_rtp(peer_connection(), String.t(), ExRTP.Packet.t()) :: :ok
   def send_rtp(peer_connection, track_id, packet) do
     GenServer.cast(peer_connection, {:send_rtp, track_id, packet})
@@ -171,6 +182,7 @@ defmodule ExWebRTC.PeerConnection do
 
   @impl true
   def init({owner, config}) do
+    {:ok, _} = Registry.register(ExWebRTC.Registry, self(), self())
     ice_config = [stun_servers: config.ice_servers, ip_filter: config.ice_ip_filter, on_data: nil]
     {:ok, ice_pid} = DefaultICETransport.start_link(:controlled, ice_config)
     {:ok, dtls_transport} = DTLSTransport.start_link(DefaultICETransport, ice_pid)
@@ -519,7 +531,7 @@ defmodule ExWebRTC.PeerConnection do
             {:reply, :ok, state}
 
           true ->
-            # that's not compliant with the W3C but it's safer not 
+            # that's not compliant with the W3C but it's safer not
             # to allow for this until we have clear use case
             {:reply, {:error, :invalid_transceiver_direction}, state}
         end
@@ -558,6 +570,119 @@ defmodule ExWebRTC.PeerConnection do
     end
   end
 
+  @impl true
+  def handle_call(:get_stats, _from, state) do
+    timestamp = System.os_time(:millisecond)
+
+    ice_stats = state.ice_transport.get_stats(state.ice_pid)
+
+    %{local_cert_info: local_cert_info, remote_cert_info: remote_cert_info} =
+      DTLSTransport.get_certs_info(state.dtls_transport)
+
+    remote_certificate =
+      if remote_cert_info != nil do
+        %{
+          id: :remote_certificate,
+          type: :certificate,
+          timestamp: timestamp,
+          fingerprint: remote_cert_info.fingerprint,
+          fingerprint_algorithm: remote_cert_info.fingerprint_algorithm,
+          base64_certificate: remote_cert_info.base64_certificate
+        }
+      else
+        %{
+          id: :remote_certificate,
+          type: :certificate,
+          timestamp: timestamp,
+          fingerprint: nil,
+          fingerprint_algorithm: nil,
+          base64_certificate: nil
+        }
+      end
+
+    local_cands =
+      Map.new(ice_stats.local_candidates, fn local_cand ->
+        cand = %{
+          id: local_cand.id,
+          timestamp: timestamp,
+          type: :local_candidate,
+          address: local_cand.address,
+          port: local_cand.port,
+          protocol: local_cand.transport,
+          candidate_type: local_cand.type,
+          priority: local_cand.priority,
+          foundation: local_cand.foundation,
+          related_address: local_cand.base_address,
+          related_port: local_cand.base_port
+        }
+
+        {cand.id, cand}
+      end)
+
+    rtp_stats =
+      Enum.flat_map(state.transceivers, fn tr ->
+        case tr.current_direction do
+          :sendonly ->
+            [RTPSender.get_stats(tr.sender, timestamp)]
+
+          :recvonly ->
+            [RTPReceiver.get_stats(tr.receiver, timestamp)]
+
+          :sendrecv ->
+            [
+              RTPSender.get_stats(tr.sender, timestamp),
+              RTPReceiver.get_stats(tr.receiver, timestamp)
+            ]
+
+          _other ->
+            []
+        end
+      end)
+      |> Map.new(fn stats -> {stats.id, stats} end)
+
+    stats = %{
+      peer_connection: %{
+        id: :peer_connection,
+        type: :peer_connection,
+        timestamp: timestamp,
+        signaling_state: state.signaling_state,
+        ice_state: state.ice_state,
+        ice_gathering_state: state.ice_gathering_state,
+        dtls_state: state.dtls_state,
+        negotiation_needed: state.negotiation_needed,
+        connection_state: state.conn_state
+      },
+      transport: %{
+        id: :transport,
+        type: :transport,
+        timestamp: timestamp,
+        bytes_sent: ice_stats.bytes_sent,
+        bytes_received: ice_stats.bytes_received,
+        packets_sent: ice_stats.packets_sent,
+        packets_received: ice_stats.packets_received,
+        ice_role: ice_stats.role,
+        ice_local_ufrag: ice_stats.local_ufrag,
+        ice_state: ice_stats.state
+      },
+      local_certificate: %{
+        id: :local_certificate,
+        type: :certificate,
+        timestamp: timestamp,
+        fingerprint: local_cert_info.fingerprint,
+        fingerprint_algorithm: local_cert_info.fingerprint_algorithm,
+        base64_certificate: local_cert_info.base64_certificate
+      },
+      remote_certificate: remote_certificate
+    }
+
+    stats =
+      stats
+      |> Map.merge(local_cands)
+      |> Map.merge(rtp_stats)
+
+    {:reply, stats, state}
+  end
+
   @impl true
   def handle_cast({:send_rtp, track_id, packet}, state) do
     # TODO: iterating over transceivers is not optimal
@@ -638,10 +763,12 @@ defmodule ExWebRTC.PeerConnection do
   @impl true
   def handle_info({:dtls_transport, _pid, {:rtp, data}}, state) do
     with {:ok, demuxer, mid, packet} <- Demuxer.demux(state.demuxer, data),
-         %RTPTransceiver{} = t <- Enum.find(state.transceivers, &(&1.mid == mid)) do
-      track_id = t.receiver.track.id
-      notify(state.owner, {:rtp, track_id, packet})
-      {:noreply, %{state | demuxer: demuxer}}
+         {idx, %RTPTransceiver{} = t} <- find_transceiver(state.transceivers, mid) do
+      receiver = RTPReceiver.receive(t.receiver, packet, data)
+      transceivers = List.update_at(state.transceivers, idx, &%{&1 | receiver: receiver})
+      state = %{state | demuxer: demuxer, transceivers: transceivers}
+      notify(state.owner, {:rtp, t.receiver.track.id, packet})
+      {:noreply, state}
     else
       nil ->
         Logger.warning("Received RTP with unrecognized MID: #{inspect(data)}")
@@ -717,7 +844,7 @@ defmodule ExWebRTC.PeerConnection do
     # mline from the last offer/answer, do it (i.e. recycle free mline)
     # * If there is no transceiver's mline, just rewrite
     # mline from the offer/answer respecting its port number i.e. whether
-    # it is rejected or not. 
+    # it is rejected or not.
     # This is to preserve the same number of mlines
     # between subsequent offer/anser exchanges.
     # * At the end, add remaining transceiver mlines
@@ -751,7 +878,7 @@ defmodule ExWebRTC.PeerConnection do
   end
 
   # next_mline_idx is future mline idx to use if there are no mlines to recycle
-  # next_mid is the next free mid 
+  # next_mid is the next free mid
   defp assign_mlines(
          transceivers,
          last_answer,
@@ -1154,7 +1281,7 @@ defmodule ExWebRTC.PeerConnection do
 
   # If signaling state is not stable i.e. we are during negotiation,
   # don't fire negotiation needed notification.
-  # We will do this when moving to the stable state as part of the 
+  # We will do this when moving to the stable state as part of the
   # steps for setting remote description.
   defp update_negotiation_needed(%{signaling_state: sig_state} = state) when sig_state != :stable,
     do: state
@@ -1172,14 +1299,14 @@ defmodule ExWebRTC.PeerConnection do
 
       negotiation_needed == false ->
         # We need to clear the flag.
-        # Consider scenario where we add a transceiver and then 
-        # remove it without performing negotiation. 
+        # Consider scenario where we add a transceiver and then
+        # remove it without performing negotiation.
         # At the end of the day, negotiation_needed flag has to be cleared.
         %{state | negotiation_needed: false}
     end
   end
 
-  # We don't support MSIDs and stopping transceivers so 
+  # We don't support MSIDs and stopping transceivers so
   # we only check 5.2 and 5.3 from 4.7.3#check-if-negotiation-is-needed
   # https://www.w3.org/TR/webrtc/#dfn-check-if-negotiation-is-needed
   defp negotiation_needed?([], _), do: false
@@ -1199,7 +1326,7 @@ defmodule ExWebRTC.PeerConnection do
     cond do
       # Consider the following scenario:
       # 1. offerer offers sendrecv
-      # 2. answerer answers with recvonly  
+      # 2. answerer answers with recvonly
       # 3. offerer changes from sendrecv to sendonly
       # We don't need to renegotiate in such a case.
       local_desc_type == :offer and