Allow p2p UDP packages to set DSCP

net/udp/udp_socket_win.cc

Index: net/udp/udp_socket_win.cc
diff --git a/net/udp/udp_socket_win.cc b/net/udp/udp_socket_win.cc
index 1f0c337fd4a609fcb783bb0382345a88ab4ecd34..430346cc90e380eb2ab1dc22267b3e9c8fdac27e 100644
--- a/net/udp/udp_socket_win.cc
+++ b/net/udp/udp_socket_win.cc
@@ -752,4 +752,83 @@ int UDPSocketWin::SetMulticastLoopbackMode(bool loopback) {
   return OK;
 }
 
+// setsockopt IP_TOS doesn't work on XP and newer. This code
+// attempts to map DSCP to the GQoS api, which will then
+// of course map it back to DSCP. Unfortunately, this does not
+// give as fine-grained control of the DSCP value as
+// setsockopt does.
+int UDPSocketWin::SetDiffServCodePoint(DiffServCodePoint dscp) {
+  QOS qos;
+  switch (dscp) {
+    case DSCP_NO_CHANGE:
+      return OK;
+
+    default:
+    case DSCP_CS0:
+    case DSCP_CS1:
+    case DSCP_AF11:
+    case DSCP_AF12:
+    case DSCP_AF13:
+      qos.SendingFlowspec.ServiceType = SERVICETYPE_BESTEFFORT;
+      qos.ReceivingFlowspec.ServiceType = SERVICETYPE_BESTEFFORT;
+      break;
+
+    case DSCP_CS2:
+    case DSCP_AF21:
+    case DSCP_AF22:
+    case DSCP_AF23:
+      qos.SendingFlowspec.ServiceType = SERVICETYPE_CONTROLLEDLOAD;
+      qos.ReceivingFlowspec.ServiceType = SERVICETYPE_CONTROLLEDLOAD;
+      break;
+
+    case DSCP_CS3:
+    case DSCP_AF31:
+    case DSCP_AF32:
+    case DSCP_AF33:
+    case DSCP_CS4:
+    case DSCP_AF41:
+    case DSCP_AF42:
+    case DSCP_AF43:
+    case DSCP_CS5:
+    case DSCP_EF:
+    case DSCP_CS6:
+      qos.SendingFlowspec.ServiceType = SERVICETYPE_GUARANTEED;
+      qos.ReceivingFlowspec.ServiceType = SERVICETYPE_GUARANTEED;
+      break;
+
+    case DSCP_CS7:
+      qos.SendingFlowspec.ServiceType = SERVICETYPE_NETWORK_CONTROL;
+      qos.ReceivingFlowspec.ServiceType = SERVICETYPE_NETWORK_CONTROL;
+      break;
+  }
+
+  qos.ReceivingFlowspec.TokenRate = 100000000;
+  qos.ReceivingFlowspec.TokenBucketSize = QOS_NOT_SPECIFIED;
+  qos.ReceivingFlowspec.PeakBandwidth = QOS_NOT_SPECIFIED;
+  qos.ReceivingFlowspec.Latency = QOS_NOT_SPECIFIED;
+  qos.ReceivingFlowspec.DelayVariation = QOS_NOT_SPECIFIED;
+  qos.ReceivingFlowspec.MinimumPolicedSize = QOS_NOT_SPECIFIED;
+  qos.ReceivingFlowspec.MaxSduSize = QOS_NOT_SPECIFIED;
+
+  // We don't actually know what bandwidth we will be
+  // using, try something really high.
+  qos.SendingFlowspec.TokenRate = 100000000;
+  qos.SendingFlowspec.TokenBucketSize = 100000000;
+  qos.SendingFlowspec.PeakBandwidth = 100000000;
+  qos.SendingFlowspec.Latency = QOS_NOT_SPECIFIED;
+  qos.SendingFlowspec.DelayVariation = QOS_NOT_SPECIFIED;
+  qos.SendingFlowspec.MinimumPolicedSize = QOS_NOT_SPECIFIED;
+  qos.SendingFlowspec.MaxSduSize = QOS_NOT_SPECIFIED;
+
+  qos.ProviderSpecific.len = 0;
+  qos.ProviderSpecific.buf = NULL;
+  DWORD bytes_returned;
+  if (WSAIoctl(socket_, SIO_SET_QOS,
+               &qos, sizeof(QOS), NULL, 0,
+               &bytes_returned,  NULL, NULL)) {
+    return MapSystemError(WSAGetLastError());
+  }
+  return OK;
+}
+
 }  // namespace net