Enusre BUNDLE group

lib/ex_webrtc/peer_connection.ex

@@ -7,9 +7,15 @@ defmodule ExWebRTC.PeerConnection do
 
   alias __MODULE__.Configuration
   alias ExICE.ICEAgent
-  alias ExWebRTC.{IceCandidate, MediaStreamTrack, RTPTransceiver, SessionDescription}
 
-  import ExWebRTC.Utils
+  alias ExWebRTC.{
+    IceCandidate,
+    MediaStreamTrack,
+    RTPTransceiver,
+    SessionDescription,
+    SDPUtils,
+    Utils
+  }
 
   @type peer_connection() :: GenServer.server()
 
@@ -121,7 +127,7 @@ defmodule ExWebRTC.PeerConnection do
         ice_ufrag: ice_ufrag,
         ice_pwd: ice_pwd,
         ice_options: "trickle",
-        fingerprint: {:sha256, hex_dump(dtls_fingerprint)},
+        fingerprint: {:sha256, Utils.hex_dump(dtls_fingerprint)},
         # TODO offer will always contain actpass
         # and answer should contain active
         # see RFC 8829 sec. 5.3.1
@@ -276,8 +282,11 @@ defmodule ExWebRTC.PeerConnection do
     # TODO apply steps listed in RFC 8829 5.10
     media = hd(sdp.media)
 
-    with {:ice_ufrag, ufrag} <- ExSDP.Media.get_attribute(media, :ice_ufrag),
-         {:ice_pwd, pwd} <- ExSDP.Media.get_attribute(media, :ice_pwd),
+    with :ok <- SDPUtils.ensure_mid(sdp),
+         :ok <- SDPUtils.ensure_bundle(sdp),
+         {:ice_ufrag, {:ice_ufrag, ufrag}} <-
+           {:ice_ufrag, ExSDP.Media.get_attribute(media, :ice_ufrag)},
+         {:ice_pwd, {:ice_pwd, pwd}} <- {:ice_pwd, ExSDP.Media.get_attribute(media, :ice_pwd)},
          {:ok, new_transceivers} <- update_transceivers(state.transceivers, sdp) do
       :ok = ICEAgent.set_remote_credentials(state.ice_agent, ufrag, pwd)
       :ok = ICEAgent.gather_candidates(state.ice_agent)
@@ -297,7 +306,9 @@ defmodule ExWebRTC.PeerConnection do
 
       {:ok, %{state | current_remote_desc: sdp, transceivers: new_transceivers}}
     else
-      nil -> {:error, :missing_ice_ufrag_or_pwd}
+      {:ice_ufrag, nil} -> {:error, :missing_ice_ufrag}
+      {:ice_pwd, nil} -> {:error, :missing_ice_pwd}
+      other -> other
     end
   end
 

lib/ex_webrtc/sdp_utils.ex

@@ -0,0 +1,52 @@
+defmodule ExWebRTC.SDPUtils do
+  @moduledoc false
+
+  @spec get_media_direction(ExSDP.Media.t()) ::
+          :sendrecv | :sendonly | :recvonly | :inactive | nil
+  def get_media_direction(media) do
+    Enum.find(media.attributes, fn attr ->
+      attr in [:sendrecv, :sendonly, :recvonly, :inactive]
+    end)
+  end
+
+  @spec ensure_mid(ExSDP.t()) :: :ok | {:error, :missing_mid | :duplicated_mid}
+  def ensure_mid(sdp) do
+    sdp.media
+    |> Enum.reduce_while({:ok, []}, fn media, {:ok, acc} ->
+      case ExSDP.Media.get_attributes(media, :mid) do
+        [{:mid, mid}] -> {:cont, {:ok, [mid | acc]}}
+        [] -> {:halt, {:error, :missing_mid}}
+        other when is_list(other) -> {:halt, {:error, :duplicated_mid}}
+      end
+    end)
+    |> case do
+      {:ok, mids} -> if Enum.uniq(mids) == mids, do: :ok, else: {:error, :duplicated_mid}
+      error -> error
+    end
+  end
+
+  @spec ensure_bundle(ExSDP.t()) ::
+          :ok
+          | {:error,
+             :non_exhaustive_bundle_group | :missing_budnle_group | :multiple_bundle_groups}
+  def ensure_bundle(sdp) do
+    groups = ExSDP.get_attributes(sdp, ExSDP.Attribute.Group)
+
+    mline_mids =
+      Enum.map(sdp.media, fn media ->
+        {:mid, mid} = ExSDP.Media.get_attribute(media, :mid)
+        mid
+      end)
+
+    case groups do
+      [%ExSDP.Attribute.Group{semantics: "BUNDLE", mids: group_mids}] ->
+        if group_mids -- mline_mids == [], do: :ok, else: {:error, :non_exhaustive_bundle_group}
+
+      [] ->
+        {:error, :missing_bundle_group}
+
+      other when is_list(other) ->
+        {:error, :multiple_bundle_groups}
+    end
+  end
+end

lib/ex_webrtc/utils.ex

@@ -7,10 +7,4 @@ defmodule ExWebRTC.Utils do
     |> :binary.bin_to_list()
     |> Enum.map_join(":", &Base.encode16(<<&1>>))
   end
-
-  def get_media_direction(media) do
-    Enum.find(media.attributes, fn attr ->
-      attr in [:sendrecv, :sendonly, :recvonly, :inactive]
-    end)
-  end
 end

mix.exs

@@ -45,7 +45,8 @@ defmodule ExWebRTC.MixProject do
 
   defp deps do
     [
-      {:ex_sdp, "~> 0.11"},
+      # {:ex_sdp, "~> 0.11"},
+      {:ex_sdp, github: "membraneframework/ex_sdp", branch: "get-attr"},
       {:ex_ice, "~> 0.1"},
       {:ex_dtls, "~> 0.13"},
 

mix.lock

@@ -11,7 +11,7 @@
   "ex_doc": {:hex, :ex_doc, "0.30.6", "5f8b54854b240a2b55c9734c4b1d0dd7bdd41f71a095d42a70445c03cf05a281", [:mix], [{:earmark_parser, "~> 1.4.31", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1", [hex: :makeup_erlang, repo: "hexpm", optional: false]}], "hexpm", "bd48f2ddacf4e482c727f9293d9498e0881597eae6ddc3d9562bd7923375109f"},
   "ex_dtls": {:hex, :ex_dtls, "0.13.0", "4d7631eefc19a8820d4f79883f379ff2ad642976bda55493d4ec4e5d10d6c078", [:mix], [{:unifex, "~> 1.0", [hex: :unifex, repo: "hexpm", optional: false]}], "hexpm", "3ece30967006ec12a4088e60514cb08847814fba8b8a21aca3862e5d1fd4a6bc"},
   "ex_ice": {:hex, :ex_ice, "0.1.0", "2653c884872d8769cf9fc655c74002a63ed6c21be1b3c2badfa42bdc74de2355", [:mix], [{:ex_stun, "~> 0.1.0", [hex: :ex_stun, repo: "hexpm", optional: false]}], "hexpm", "e2539a321f87f31997ba974d532d00511e5828f2f113b550b1ef6aa799dd2ffe"},
-  "ex_sdp": {:hex, :ex_sdp, "0.11.0", "19e3af1d70b945381752db3139dfc22a19da1e9394036721449b7fb8c49fe039", [:mix], [{:bunch, "~> 1.3", [hex: :bunch, repo: "hexpm", optional: false]}, {:uuid, "~> 1.1", [hex: :uuid, repo: "hexpm", optional: false]}], "hexpm", "7a3fe42f4ec0c18de09b10464829c27482d81d9c50c21bdebdbcfe17d2046408"},
+  "ex_sdp": {:git, "https://github.com/membraneframework/ex_sdp.git", "2d8dc9e2c964ed2d883a21d88547e9c5aaf0df1a", [branch: "get-attr"]},
   "ex_stun": {:hex, :ex_stun, "0.1.0", "252474bf4c8519fbf4bc0fbfc6a1b846a634b1478c65dbbfb4b6ab4e33c2a95a", [:mix], [], "hexpm", "629fc8be45b624a92522f81d85ba001877b1f0745889a2419bdb678790d7480c"},
   "excoveralls": {:hex, :excoveralls, "0.17.1", "83fa7906ef23aa7fc8ad7ee469c357a63b1b3d55dd701ff5b9ce1f72442b2874", [:mix], [{:castore, "~> 1.0", [hex: :castore, repo: "hexpm", optional: true]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "95bc6fda953e84c60f14da4a198880336205464e75383ec0f570180567985ae0"},
   "file_system": {:hex, :file_system, "0.2.10", "fb082005a9cd1711c05b5248710f8826b02d7d1784e7c3451f9c1231d4fc162d", [:mix], [], "hexpm", "41195edbfb562a593726eda3b3e8b103a309b733ad25f3d642ba49696bf715dc"},

test/peer_connection_test.exs

@@ -95,4 +95,28 @@ defmodule ExWebRTC.PeerConnectionTest do
     assert_receive {:ex_webrtc, ^pc, {:track, %MediaStreamTrack{mid: "1", kind: :video}}}
     refute_receive {:ex_webrtc, ^pc, {:track, %MediaStreamTrack{}}}
   end
+
+  test "set_remote_description/2" do
+    {:ok, pc} = PeerConnection.start_link()
+
+    raw_sdp = ExSDP.new()
+
+    mline =
+      ExSDP.Media.new("audio", 9, "UDP/TLS/RTP/SAVPF", [96])
+      |> ExSDP.Media.add_attribute({:mid, "0"})
+
+    sdp = ExSDP.add_media(raw_sdp, mline) |> to_string()
+    offer = %SessionDescription{type: :offer, sdp: sdp}
+    assert {:error, :missing_bundle_group} = PeerConnection.set_remote_description(pc, offer)
+
+    mline = ExSDP.Media.add_attribute(mline, {:mid, "1"})
+    sdp = ExSDP.add_media(raw_sdp, mline) |> to_string()
+    offer = %SessionDescription{type: :offer, sdp: sdp}
+    assert {:error, :duplicated_mid} = PeerConnection.set_remote_description(pc, offer)
+
+    mline = ExSDP.Media.new("audio", 9, "UDP/TLS/RTP/SAVPF", [96])
+    sdp = ExSDP.add_media(raw_sdp, mline) |> to_string()
+    offer = %SessionDescription{type: :offer, sdp: sdp}
+    assert {:error, :missing_mid} = PeerConnection.set_remote_description(pc, offer)
+  end
 end