IP QoS support in libvncclient.

This enables setting the DSCP/Traffic Class field of IP/IPv6 packets
sent by a client. For example starting a client with -qosdscp 184
marks all outgoing traffic for expedited forwarding.

Implementation for Win32 is still a TODO, though. See
http://betelco.blogspot.com/2009/03/dscp-marking-under-windows-at.html
for an overview of the Win32 QoS API mess...

1 files changed, 49 insertions, 0 deletions

diff --git a/libvncclient/sockets.c b/libvncclient/sockets.c
index 28b0256..e9a4b53 100644
--- a/libvncclient/sockets.c
+++ b/libvncclient/sockets.c
@@ -566,6 +566,55 @@ SetNonBlocking(int sock)
 }
 
 
+
+/*
+ * SetDSCP sets a socket's IP QoS parameters aka Differentiated Services Code Point field
+ */
+
+rfbBool
+SetDSCP(int sock, int dscp)
+{
+#ifdef WIN32
+  rfbClientErr("Setting of QoS IP DSCP not implemented for Windows\n");
+  return TRUE;
+#else
+  int level, cmd;
+  struct sockaddr addr;
+  socklen_t addrlen = sizeof(addr);
+
+  if(getsockname(sock, &addr, &addrlen) != 0) {
+    rfbClientErr("Setting socket QoS failed while getting socket address: %s\n",strerror(errno));
+    return FALSE;
+  }
+
+  switch(addr.sa_family)
+    {
+#ifdef LIBVNCSERVER_IPv6
+    case AF_INET6:
+      level = IPPROTO_IPV6;
+      cmd = IPV6_TCLASS;
+      break;
+#endif
+    case AF_INET:
+      level = IPPROTO_IP;
+      cmd = IP_TOS;
+      break;
+    default:
+      rfbClientErr("Setting socket QoS failed: Not bound to IP address");
+      return FALSE;
+    }
+
+  if(setsockopt(sock, level, cmd, (void*)&dscp, sizeof(dscp)) != 0) {
+    rfbClientErr("Setting socket QoS failed: %s\n", strerror(errno));
+    return FALSE;
+  }
+
+  return TRUE;
+#endif
+}
+
+
+
 /*
  * StringToIPAddr - convert a host string to an IP address.
  */