Description: please apply "real full bolt" patch
 Even when compiled with "-DFULL_BOLT", slirp applies a small delay to
 TCP ACKs, which results in the upload speed being capped to circa 46Kb/s.
 Manfread Haertel published a tiny patch for this on the UML mailing list:
 http://article.gmane.org/gmane.linux.uml.user/13973
 .
Author: Manfred Haertel <Manfred.Haertel <at> rz-online.de>
Bug-Debian: http://bugs.debian.org/658359

Index: slirp-1.0.17/src/tcp_input.c
===================================================================
--- slirp-1.0.17.orig/src/tcp_input.c	2004-09-01 09:36:44.000000000 +0200
+++ slirp-1.0.17/src/tcp_input.c	2012-03-05 10:02:15.813322621 +0100
@@ -598,6 +598,10 @@
  *			    ((so->so_iptos & IPTOS_LOWDELAY) && 
  *			     ((struct tcpiphdr_2 *)ti)->first_char == (char)27)) {
  */
+#ifdef FULL_BOLT
+			tp->t_flags |= TF_ACKNOW;
+			tcp_output(tp);
+#else
 			if ((unsigned)ti->ti_len == 1 &&
 			    ((struct tcpiphdr_2 *)ti)->first_char == (char)27) {
 				tp->t_flags |= TF_ACKNOW;
@@ -605,6 +609,7 @@
 			} else {
 				tp->t_flags |= TF_DELACK;
 			}
+#endif
 			return;
 		}
 	} /* header prediction */