RE: [ns] How to run emulation programs in NS-2?

["Schramp, R." <R.Schramp@kpn.com>]

The .bin file used to be a "patch" file.

Typical use is to set your working directory to the place of the original
code e.g.

cd /home/mmrenyu/ns/ns-allinone/ns-2.1b8a

here you type something like

patch -p1 < ~mmrenyu/patch


The -p1 tells patch to strip the first directory from the directory's in the
patch file. ensuring that the paths in the patch file point to existing
files.

Although the patch file is against the latest version of ns, I expect no big
problems patching it automatically to a litle older version. If you get
errors you can also patch the source files by hand as it is only about 20
lines of code.

Best regards,

Ruud Schramp


------CUT HERE: <Patch>------
diff -Naur ns-2.1b8a/emulate/net-ip.cc ns-2.1b8a_patched/emulate/net-ip.cc
--- ns-2.1b8a/emulate/net-ip.cc	Mon Jun 25 20:01:08 2001
+++ ns-2.1b8a_patched/emulate/net-ip.cc	Fri Aug 31 13:05:29 2001
@@ -573,10 +573,22 @@
 IPNetwork::send(u_char* buf, int len)
 {
 	struct ip *ip = (struct ip*) buf;
+#ifdef __linux__ 
+// r.schramp@kpn.com: For raw sockets on linux the send does not work,
+// all packets show up only on the loopback device and are not routed
+// to the correct host. Using sendto on a closed socket solves this problem
+	ip->ip_len = (ip->ip_len);
+	ip->ip_off = (ip->ip_off);
+        sockaddr_in sin;
+	memset((char *)&sin, 0, sizeof(sin));
+	sin.sin_family = AF_INET;
+        sin.sin_addr = ip->ip_dst;
+	return (::sendto(ssock_, (char*)buf, len, 0,(sockaddr *)
&sin,sizeof(sin)));
+#else
 	ip->ip_len = ntohs(ip->ip_len);
 	ip->ip_off = ntohs(ip->ip_off);
-
 	return (::send(ssock_, (char*)buf, len, 0));
+#endif
 }
 
 int IPNetwork::command(int argc, const char*const* argv)
@@ -714,8 +726,13 @@
 		return (-1);
 	}
 
+#ifndef __linux__
 	// sort of curious, but do a connect() even though we have
 	// HDRINCL on.  Otherwise, we get ENOTCONN when doing a send()
+
+	// r.schramp@kpn.com: the send does not work under linux, this has
+	// been replaced by a sendto, however this requires a closed socket
+
 	sockaddr_in sin;
 	in_addr ia = { INADDR_ANY };
 	if (connectsock(fd, ia, 0, sin) < 0) {
@@ -723,6 +740,7 @@
 	"IPNetwork(%s): open: unable to connect : %s\n",
 			name(), strerror(errno));
 	}
+#endif
 	rsock_ = ssock_ = fd;
 	mode_ = mode;
 	NIDEBUG5("IPNetwork(%s): opened with mode %d, rsock_:%d,
ssock_:%d\n",
diff -Naur ns-2.1b8a/emulate/tcptap.cc ns-2.1b8a_patched/emulate/tcptap.cc
--- ns-2.1b8a/emulate/tcptap.cc	Mon Jun 25 20:01:08 2001
+++ ns-2.1b8a_patched/emulate/tcptap.cc	Fri Aug 31 13:08:19 2001
@@ -36,6 +36,13 @@
     "@(#) $Header: /nfs/jade/vint/CVSROOT/ns-2/emulate/tcptap.cc,v 1.1
2001/05/15 21:23:38 alefiyah Exp $ (ISI)";
 #endif
 
+#ifdef __linux__
+// r.schramp@kpn.com: The ip header structure under linux defaults to a
different structure, this
+// define makes the BSD ip header the default one. Actualy this solution
does not win the beaty
+// contest, anyone with knowledge of makefiles and configure may want to
include it there
+#define _BSD_SOURCE
+#endif
+
 #include "tcptap.h"
--------CUT HERE <patch>-------