agent: Add APIs to set the send and receive buffers of UDP sockets

Adds nice_socket_set_udp_send_buffer() and nice_socket_set_udp_receive_buffer().
These APIs set the SO_SNDBUF and SO_RCVBUF options on UDP sockets.

agent/agent.c

@@ -2925,6 +2925,25 @@ _priv_set_socket_opts (NiceAgent *agent, NiceSocket *sock, Stream *stream)
         stream->tos, g_strerror (errno));
   }
 #endif
+
+
+  if (stream->sndbuf != 0 &&
+      g_socket_get_protocol (sock->fileno) == G_SOCKET_PROTOCOL_UDP) {
+    if (setsockopt (g_socket_get_fd (sock->fileno), SOL_SOCKET,
+            SO_SNDBUF, (const char *) &stream->sndbuf, sizeof (stream->rcvbuf)) < 0) {
+      nice_debug ("Agent %p: Could not set socket send buffer to %d: %s", agent,
+          stream->sndbuf, g_strerror (errno));
+    }
+  }
+
+  if (stream->rcvbuf != 0 &&
+      g_socket_get_protocol (sock->fileno) == G_SOCKET_PROTOCOL_UDP) {
+    if (setsockopt (g_socket_get_fd (sock->fileno), SOL_SOCKET,
+            SO_RCVBUF, (const char *) &stream->rcvbuf, sizeof (stream->rcvbuf)) < 0) {
+      nice_debug ("Agent %p: Could not set socket receive buffer to %d: %s",
+          agent, stream->rcvbuf, g_strerror (errno));
+    }
+  }
 }
 
 static void
@@ -2975,3 +2994,43 @@ nice_agent_set_software (NiceAgent *agent, const gchar *software)
 
   agent_unlock ();
 }
+
+void
+nice_agent_set_stream_udp_recv_buffer (NiceAgent *agent, guint stream_id,
+    gint rcvbuf)
+{
+  Stream *stream;
+
+  agent_lock();
+
+  rcvbuf = MAX (1, rcvbuf);
+
+  stream = agent_find_stream (agent, stream_id);
+
+  if (stream && stream->rcvbuf != rcvbuf) {
+    stream->rcvbuf = rcvbuf;
+    priv_update_socket_opts (agent, stream);
+  }
+
+  agent_unlock();
+}
+
+void
+nice_agent_set_stream_udp_send_buffer (NiceAgent *agent, guint stream_id,
+    gint sndbuf)
+{
+  Stream *stream;
+
+  agent_lock();
+
+  sndbuf = MAX (1, sndbuf);
+
+  stream = agent_find_stream (agent, stream_id);
+
+  if (stream && stream->sndbuf != sndbuf) {
+    stream->sndbuf = sndbuf;
+    priv_update_socket_opts (agent, stream);
+  }
+
+  agent_unlock();
+}

agent/agent.h

@@ -730,7 +730,6 @@ void nice_agent_set_stream_tos (
   gint tos);
 
 
-
 /**
  * nice_agent_set_software:
  * @agent: The #NiceAgent Object
@@ -759,6 +758,40 @@ void nice_agent_set_stream_tos (
  */
 void nice_agent_set_software (NiceAgent *agent, const gchar *software);
 
+
+/**
+ * nice_agent_set_stream_udp_recv_buffer:
+ * @agent: The #NiceAgent Object
+ * @stream_id: The ID of the stream
+ * @rcvbuf: The size of the receive buffer
+ *
+ * Sets the SO_RCVBUF field on the stream's sockets' options. This value may be
+ * clamped or ignored by the operating system.
+ *
+ * Since: 0.1.4
+ */
+void nice_agent_set_stream_udp_recv_buffer (
+  NiceAgent *agent,
+  guint stream_id,
+  gint rcvbuf);
+
+
+/**
+ * nice_agent_set_stream_udp_send_buffer:
+ * @agent: The #NiceAgent Object
+ * @stream_id: The ID of the stream
+ * @sndbuf: The size of the send buffer
+ *
+ * Sets the SO_SNDBUF field on the stream's sockets' options. This value may be
+ * clamped or ignored by the operating system.
+ *
+ * Since: 0.1.4
+ */
+void nice_agent_set_stream_udp_send_buffer (
+  NiceAgent *agent,
+  guint stream_id,
+  gint sndbuf);
+
 G_END_DECLS
 
 #endif /* _AGENT_H */

agent/stream.h

@@ -72,6 +72,8 @@ struct _Stream
   gchar remote_password[NICE_STREAM_MAX_PWD];
   gboolean gathering;
   gint tos;
+  gint sndbuf;
+  gint rcvbuf;
 };