FreeBSD kernel support with DCE

Overview

This module provides an additional network stack support for DCE with FreeBSD kernel.

• This is a POSIX userspace application support over FreeBSD kernel over DCE, over ns-3 over Linux.
• This is NOT the DCE running on FreeBSD operating system (right now DCE only run on Linux).

Usage

bake.py configure -e dce-freebsd-dev
bake.py download
bake.py build

Once you finished to build dce-freebsd module, you can write a simulation script that uses FreeBSD kernel as a network stack. All you need is to specify the library name with an attribute Library to ns3::FreeBSDSocketFdFactory, then install FreeBSDStackHelper to the nodes.

DceManagerHelper processManager;
processManager.SetNetworkStack ("ns3::FreeBSDSocketFdFactory",
                           "Library", StringValue ("libfreebsd.so"));
processManager.Install (nodes);
FreeBSDStackHelper stack;
stack.Install (nodes);

How to use your kernel extension with DCE ?

No configuration support (like make menuconfig in Linux) right now. You need to add files into sys/sim/Makefile.

The following represents an example to add Multipath-TCP feature of FreeBSD by adding mptcp_subr.o to the freebsd-sim/sys/sim/Makefile. If you want to add your code into the kernel build, you may add object file names that is from your own codes.

diff --git a/sys/sim/Makefile b/sys/sim/Makefile
index 8115e3d..1b2feab 100644
--- a/sys/sim/Makefile
+++ b/sys/sim/Makefile
@@ -100,7 +100,7 @@ ip_divert.o tcp_hostcache.o ip_ecn.o tcp_input.o ip_encap.o
\
 tcp_lro.o ip_fastfwd.o tcp_offload.o ip_gre.o tcp_output.o \
 ip_icmp.o tcp_reass.o ip_id.o tcp_sack.o ip_input.o tcp_subr.o \
 tcp_syncache.o ip_mroute.o tcp_timer.o ip_options.o tcp_timewait.o \
-ip_output.o tcp_usrreq.o raw_ip.o udp_usrreq.o if_llatbl.o
+ip_output.o tcp_usrreq.o raw_ip.o udp_usrreq.o if_llatbl.o mptcp_subr.o

Limitations

While this release gives a proof of concept to use FreeBSD kernel with DCE, there are tons of limitations (listed below) that have to be improved in near future.

• No sysctl
• No IPv6 address configuration
• No ifconfig

• No delete IP addresses support

• No route command
• No quagga, new FreeBSD-version glue code needed
• No extensive test
• No DCE Cradle
• No Poll implementation
• No getifaddr/routing socket implementations
• Socket options missing (incosistent defined value: SOL_SOCKET(Linux/FreeBSD)=20/0xffff)

TODO

• refactoring with LinuxStackHelper/FreeBSDStackHelper
• refactoring with wscript (–enable-kernel-stack uses both FreeBSD/Linux for now)