From ffd3b391c8907430dcbabaf0f1e28552b88fa836 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20Dr=C3=B6ge?= <sebastian@centricular.com>
Date: Tue, 17 Nov 2015 12:39:05 +0200
Subject: [PATCH] udpsrc: Add "loop" property for enabling/disabling multicast
 loopback

On POSIX, IP_MULTICAST_LOOP is a setting for the sender socket. On Windows it
is a setting for the receiver socket. As such we will need it on udpsrc too to
allow filtering out our own multicast packets.
---
 gst/udp/gstudpsrc.c | 17 ++++++++++++++++-
 gst/udp/gstudpsrc.h |  1 +
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/gst/udp/gstudpsrc.c b/gst/udp/gstudpsrc.c
index 8da3585dbf..34aa7e4644 100644
--- a/gst/udp/gstudpsrc.c
+++ b/gst/udp/gstudpsrc.c
@@ -138,6 +138,7 @@ static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src",
 #define UDP_DEFAULT_USED_SOCKET        NULL
 #define UDP_DEFAULT_AUTO_MULTICAST     TRUE
 #define UDP_DEFAULT_REUSE              TRUE
+#define UDP_DEFAULT_LOOP               TRUE
 
 enum
 {
@@ -156,7 +157,8 @@ enum
   PROP_USED_SOCKET,
   PROP_AUTO_MULTICAST,
   PROP_REUSE,
-  PROP_ADDRESS
+  PROP_ADDRESS,
+  PROP_LOOP
 };
 
 static void gst_udpsrc_uri_handler_init (gpointer g_iface, gpointer iface_data);
@@ -266,6 +268,11 @@ gst_udpsrc_class_init (GstUDPSrcClass * klass)
           "Address to receive packets for. This is equivalent to the "
           "multicast-group property for now", UDP_DEFAULT_MULTICAST_GROUP,
           G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+  g_object_class_install_property (gobject_class, PROP_LOOP,
+      g_param_spec_boolean ("loop", "Multicast Loopback",
+          "Used for setting the multicast loop parameter. TRUE = enable,"
+          " FALSE = disable", UDP_DEFAULT_LOOP,
+          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
 
   gst_element_class_add_pad_template (gstelement_class,
       gst_static_pad_template_get (&src_template));
@@ -305,6 +312,7 @@ gst_udpsrc_init (GstUDPSrc * udpsrc)
   udpsrc->auto_multicast = UDP_DEFAULT_AUTO_MULTICAST;
   udpsrc->used_socket = UDP_DEFAULT_USED_SOCKET;
   udpsrc->reuse = UDP_DEFAULT_REUSE;
+  udpsrc->loop = UDP_DEFAULT_LOOP;
 
   /* configure basesrc to be a live source */
   gst_base_src_set_live (GST_BASE_SRC (udpsrc), TRUE);
@@ -791,6 +799,9 @@ gst_udpsrc_set_property (GObject * object, guint prop_id, const GValue * value,
     case PROP_REUSE:
       udpsrc->reuse = g_value_get_boolean (value);
       break;
+    case PROP_LOOP:
+      udpsrc->loop = g_value_get_boolean (value);
+      break;
     default:
       break;
   }
@@ -845,6 +856,9 @@ gst_udpsrc_get_property (GObject * object, guint prop_id, GValue * value,
     case PROP_REUSE:
       g_value_set_boolean (value, udpsrc->reuse);
       break;
+    case PROP_LOOP:
+      g_value_set_boolean (value, udpsrc->loop);
+      break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -952,6 +966,7 @@ gst_udpsrc_open (GstUDPSrc * src)
       goto bind_error;
 
     g_object_unref (bind_saddr);
+    g_socket_set_multicast_loopback (src->used_socket, src->loop);
   } else {
     GST_DEBUG_OBJECT (src, "using provided socket %p", src->socket);
     /* we use the configured socket, try to get some info about it */
diff --git a/gst/udp/gstudpsrc.h b/gst/udp/gstudpsrc.h
index 5d7e340dbc..a476483224 100644
--- a/gst/udp/gstudpsrc.h
+++ b/gst/udp/gstudpsrc.h
@@ -60,6 +60,7 @@ struct _GstUDPSrc {
   gboolean   close_socket;
   gboolean   auto_multicast;
   gboolean   reuse;
+  gboolean   loop;
 
   /* stats */
   guint      max_size;