Don't fail if there is junk byte in origin attribute

Author: varsill

lib/ex_sdp/origin.ex

@@ -52,8 +52,18 @@ defmodule ExSDP.Origin do
   end
 
   @spec parse(binary()) ::
-          {:ok, t()} | {:error, :invalid_addrtype | :invalid_address}
-  def parse(origin) do
+          {:ok, t()}
+          | {:error, :invalid_addrtype | :invalid_address | :too_few_fields | :too_many_fields}
+  def parse(origin_binary) do
+    with {:ok, origin} <- do_parse(origin_binary, 6) do
+      {:ok, origin}
+    else
+      {:error, :too_many_fields} -> do_parse(origin_binary, 7)
+      error -> error
+    end
+  end
+
+  defp do_parse(origin, 6) do
     with {:ok, [username, sess_id, sess_version, nettype, addrtype, address]} <-
            Utils.split(origin, " ", 6),
          {:ok, addrtype} <- Address.parse_addrtype(addrtype),
@@ -75,6 +85,29 @@ defmodule ExSDP.Origin do
     end
   end
 
+  # a workaround to support SDP sent by Tapo C320WS camera which puts an additional junk byte in the origin attribute
+  defp do_parse(origin, 7) do
+    with {:ok, [username, sess_id, sess_version, _junk, nettype, addrtype, address]} <-
+           Utils.split(origin, " ", 7),
+         {:ok, addrtype} <- Address.parse_addrtype(addrtype),
+         {:ok, address} <- Address.parse_address(address) do
+      # check whether fqdn
+      address = if is_binary(address), do: {addrtype, address}, else: address
+
+      origin = %__MODULE__{
+        username: username,
+        session_id: String.to_integer(sess_id),
+        session_version: String.to_integer(sess_version),
+        network_type: nettype,
+        address: address
+      }
+
+      {:ok, origin}
+    else
+      {:error, _reason} = error -> error
+    end
+  end
+
   @doc """
   Increments `session_version` field.
 

lib/ex_sdp/utils.ex

@@ -74,10 +74,15 @@ defmodule ExSDP.Utils do
   end
 
   @spec split(String.t(), String.t() | [String.t()] | :binary.cp() | Regex.t(), any) ::
-          {:error, :too_few_fields} | {:ok, [String.t()]}
+          {:error, :too_few_fields | :too_many_fields} | {:ok, [String.t()]}
   def split(origin, delim, expected_len) do
-    split = String.split(origin, delim, parts: expected_len)
-    if length(split) == expected_len, do: {:ok, split}, else: {:error, :too_few_fields}
+    split = String.split(origin, delim)
+
+    cond do
+      length(split) == expected_len -> {:ok, split}
+      length(split) < expected_len -> {:error, :too_few_fields}
+      length(split) > expected_len -> {:error, :too_many_fields}
+    end
   end
 
   @spec parse_payload_type(binary) :: {:ok, 0..127} | {:errror, :invalid_pt}

mix.exs

@@ -1,7 +1,7 @@
 defmodule ExSDP.MixProject do
   use Mix.Project
 
-  @version "1.1.1"
+  @version "1.1.2"
   @github_url "https://github.com/membraneframework/ex_sdp"
 
   def project do

test/ex_sdp/origin_test.exs

@@ -43,6 +43,17 @@ defmodule ExSDP.OriginTest do
                 username: "jdoe"
               }} = Origin.parse("jdoe 2890844526 2890842807 IN IP4 host.origin.name")
     end
+
+    test "supports improper SDP provided by Tapo C320WS cameras" do
+      assert {:ok, origin} = Origin.parse("jdoe 2890844526 2890842807 1 IN IP4 10.47.16.5")
+
+      assert origin == %Origin{
+               session_id: 2_890_844_526,
+               address: {10, 47, 16, 5},
+               session_version: 2_890_842_807,
+               username: "jdoe"
+             }
+    end
   end
 
   describe "Origin serializer" do