Add local/remote ICE candidates to current/pending description. (#83)

lib/ex_webrtc/ice_transport.ex

@@ -11,6 +11,8 @@ defmodule ExWebRTC.ICETransport do
   @callback end_of_candidates(pid()) :: :ok
   @callback gather_candidates(pid()) :: :ok
   @callback get_local_credentials(pid()) :: {:ok, ufrag :: binary(), pwd :: binary()}
+  @callback get_local_candidates(pid()) :: [binary()]
+  @callback get_remote_candidates(pid()) :: [binary()]
   @callback restart(pid()) :: :ok
   @callback send_data(pid(), binary()) :: :ok
   @callback set_remote_credentials(pid(), ufrag :: binary(), pwd :: binary()) :: :ok
@@ -38,6 +40,10 @@ defmodule ExWebRTC.DefaultICETransport do
   @impl true
   defdelegate get_local_credentials(pid), to: ICEAgent
   @impl true
+  defdelegate get_local_candidates(pid), to: ICEAgent
+  @impl true
+  defdelegate get_remote_candidates(pid), to: ICEAgent
+  @impl true
   defdelegate restart(pid), to: ICEAgent
   @impl true
   defdelegate send_data(pid, data), to: ICEAgent

lib/ex_webrtc/peer_connection.ex

@@ -110,6 +110,11 @@ defmodule ExWebRTC.PeerConnection do
     GenServer.call(peer_connection, {:set_local_description, description})
   end
 
+  @spec get_local_description(peer_connection()) :: SessionDescription.t() | nil
+  def get_local_description(peer_connection) do
+    GenServer.call(peer_connection, :get_local_description)
+  end
+
   @spec get_current_local_description(peer_connection()) :: SessionDescription.t() | nil
   def get_current_local_description(peer_connection) do
     GenServer.call(peer_connection, :get_current_local_description)
@@ -121,6 +126,11 @@ defmodule ExWebRTC.PeerConnection do
     GenServer.call(peer_connection, {:set_remote_description, description})
   end
 
+  @spec get_remote_description(peer_connection()) :: SessionDescription.t() | nil
+  def get_remote_description(peer_connection) do
+    GenServer.call(peer_connection, :get_remote_description)
+  end
+
   @spec get_current_remote_description(peer_connection()) :: SessionDescription.t() | nil
   def get_current_remote_description(peer_connection) do
     GenServer.call(peer_connection, :get_current_remote_description)
@@ -385,15 +395,18 @@ defmodule ExWebRTC.PeerConnection do
   end
 
   @impl true
-  def handle_call(:get_current_local_description, _from, state) do
-    case state.current_local_desc do
-      nil ->
-        {:reply, nil, state}
+  def handle_call(:get_local_description, _from, state) do
+    desc = state.pending_local_desc || state.current_local_desc
+    candidates = state.ice_transport.get_local_candidates(state.ice_pid)
+    desc = do_get_description(desc, candidates)
+    {:reply, desc, state}
+  end
 
-      {type, sdp} ->
-        desc = %SessionDescription{type: type, sdp: to_string(sdp)}
-        {:reply, desc, state}
-    end
+  @impl true
+  def handle_call(:get_current_local_description, _from, state) do
+    candidates = state.ice_transport.get_local_candidates(state.ice_pid)
+    desc = do_get_description(state.current_local_desc, candidates)
+    {:reply, desc, state}
   end
 
   @impl true
@@ -405,15 +418,18 @@ defmodule ExWebRTC.PeerConnection do
   end
 
   @impl true
-  def handle_call(:get_current_remote_description, _from, state) do
-    case state.current_remote_desc do
-      nil ->
-        {:reply, nil, state}
+  def handle_call(:get_remote_description, _from, state) do
+    desc = state.pending_remote_desc || state.current_remote_desc
+    candidates = state.ice_transport.get_remote_candidates(state.ice_pid)
+    desc = do_get_description(desc, candidates)
+    {:reply, desc, state}
+  end
 
-      {type, sdp} ->
-        desc = %SessionDescription{type: type, sdp: to_string(sdp)}
-        {:reply, desc, state}
-    end
+  @impl true
+  def handle_call(:get_current_remote_description, _from, state) do
+    candidates = state.ice_transport.get_remote_candidates(state.ice_pid)
+    desc = do_get_description(state.current_remote_desc, candidates)
+    {:reply, desc, state}
   end
 
   @impl true
@@ -1463,6 +1479,13 @@ defmodule ExWebRTC.PeerConnection do
     end
   end
 
+  defp do_get_description(nil, _candidates), do: nil
+
+  defp do_get_description({type, sdp}, candidates) do
+    sdp = SDPUtils.add_ice_candidates(sdp, candidates)
+    %SessionDescription{type: type, sdp: to_string(sdp)}
+  end
+
   defp generate_ssrc(state) do
     rtp_sender_ssrcs = Enum.map(state.transceivers, & &1.sender.ssrc)
     ssrcs = MapSet.new(Map.keys(state.demuxer.ssrc_to_mid) ++ rtp_sender_ssrcs)

lib/ex_webrtc/sdp_utils.ex

@@ -127,6 +127,13 @@ defmodule ExWebRTC.SDPUtils do
     |> Enum.map(fn {"candidate", attr} -> attr end)
   end
 
+  @spec add_ice_candidates(ExSDP.t(), [String.t()]) :: ExSDP.t()
+  def add_ice_candidates(sdp, candidates) do
+    candidates = Enum.map(candidates, &{"candidate", &1})
+    media = Enum.map(sdp.media, &ExSDP.add_attributes(&1, candidates))
+    %ExSDP{sdp | media: media}
+  end
+
   @spec get_dtls_role(ExSDP.t()) ::
           {:ok, :active | :passive | :actpass}
           | {:error, :missing_dtls_role | :conflicting_dtls_roles}

mix.exs

@@ -51,7 +51,7 @@ defmodule ExWebRTC.MixProject do
   defp deps do
     [
       {:ex_sdp, "~> 0.15.0"},
-      {:ex_ice, "~> 0.6.0"},
+      {:ex_ice, github: "elixir-webrtc/ex_ice"},
       {:ex_dtls, "~> 0.15.0"},
       {:ex_libsrtp, "~> 0.7.1"},
       {:ex_rtp, "~> 0.3.0"},

mix.lock

@@ -13,7 +13,7 @@
   "erlex": {:hex, :erlex, "0.2.6", "c7987d15e899c7a2f34f5420d2a2ea0d659682c06ac607572df55a43753aa12e", [:mix], [], "hexpm", "2ed2e25711feb44d52b17d2780eabf998452f6efda104877a3881c2f8c0c0c75"},
   "ex_doc": {:hex, :ex_doc, "0.31.1", "8a2355ac42b1cc7b2379da9e40243f2670143721dd50748bf6c3b1184dae2089", [:mix], [{:earmark_parser, "~> 1.4.39", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_c, ">= 0.1.1", [hex: :makeup_c, repo: "hexpm", optional: true]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1", [hex: :makeup_erlang, repo: "hexpm", optional: false]}], "hexpm", "3178c3a407c557d8343479e1ff117a96fd31bafe52a039079593fb0524ef61b0"},
   "ex_dtls": {:hex, :ex_dtls, "0.15.1", "34b3600ff13eebf6c96be033005cc110ea5beef98394631365ec26b493df80c5", [:mix], [{:unifex, "~> 1.0", [hex: :unifex, repo: "hexpm", optional: false]}], "hexpm", "9cfebdfe9111c0f68c77667cb9366e4a6f17e8a240975ffd100148de57478a29"},
-  "ex_ice": {:hex, :ex_ice, "0.6.1", "6e28c38a750c36e8ecea359bcff8c88ed47be036d7b217f376480eccd1d2ed08", [:mix], [{:ex_stun, "~> 0.1.0", [hex: :ex_stun, repo: "hexpm", optional: false]}], "hexpm", "cdc5d0199930c2be66c473b7a60d4786c63d23a624f7f52a2b08c3ea059669fe"},
+  "ex_ice": {:git, "https://github.com/elixir-webrtc/ex_ice.git", "3d98186bac257e671e4fabaf930729c3299adea7", []},
   "ex_libsrtp": {:hex, :ex_libsrtp, "0.7.2", "211bd89c08026943ce71f3e2c0231795b99cee748808ed3ae7b97cd8d2450b6b", [:mix], [{:bunch, "~> 1.6", [hex: :bunch, repo: "hexpm", optional: false]}, {:bundlex, "~> 1.3", [hex: :bundlex, repo: "hexpm", optional: false]}, {:membrane_precompiled_dependency_provider, "~> 0.1.0", [hex: :membrane_precompiled_dependency_provider, repo: "hexpm", optional: false]}, {:unifex, "~> 1.1", [hex: :unifex, repo: "hexpm", optional: false]}], "hexpm", "2e20645d0d739a4ecdcf8d4810a0c198120c8a2f617f2b75b2e2e704d59f492a"},
   "ex_rtcp": {:hex, :ex_rtcp, "0.2.0", "7599506340835d5e879ca04c6e90b25c56340ffedd4d345c14b1c0fc858446c9", [:mix], [], "hexpm", "5a5b47a2549bd2ae0bb03ec87f166f561c031ff6c8bbe189bde1e68e8578a99f"},
   "ex_rtp": {:hex, :ex_rtp, "0.3.0", "d18d0de39875958902816284f79c8cd51ec83d39bdd14edf6a5b069926268a43", [:mix], [], "hexpm", "cec8398237095b02438842cfc74487c3cbaeb7fe29e4c62ae11457a0ddd99754"},

test/ex_webrtc/dtls_transport_test.exs

@@ -35,6 +35,12 @@ defmodule ExWebRTC.DTLSTransportTest do
     @impl true
     def get_local_credentials(_state), do: {:ok, "testufrag", "testpwd"}
 
+    @impl true
+    def get_local_candidates(_ice_pid), do: []
+
+    @impl true
+    def get_remote_candidates(_ice_pid), do: []
+
     @impl true
     def restart(ice_pid), do: ice_pid
 

test/ex_webrtc/peer_connection_test.exs

@@ -224,6 +224,27 @@ defmodule ExWebRTC.PeerConnectionTest do
     :ok = PeerConnection.close(pc2)
   end
 
+  describe "get_local_description/1" do
+    test "includes ICE candidates" do
+      {:ok, pc} = PeerConnection.start()
+      {:ok, _sender} = PeerConnection.add_transceiver(pc, :audio)
+      {:ok, offer} = PeerConnection.create_offer(pc)
+      :ok = PeerConnection.set_local_description(pc, offer)
+
+      assert_receive {:ex_webrtc, _from, {:ice_candidate, cand}}
+      desc = PeerConnection.get_local_description(pc)
+
+      assert desc != nil
+
+      "a=" <> desc_cand =
+        desc.sdp
+        |> String.split("\r\n")
+        |> Enum.find(&String.starts_with?(&1, "a=candidate:"))
+
+      assert desc_cand == cand.candidate
+    end
+  end
+
   describe "set_remote_description/2" do
     test "MID" do
       {:ok, pc} = PeerConnection.start_link()