sysctl.conf hardened for FreeBSD with Xen

# Are being run under another UID.
security.bsd.see_other_gids=0
security.bsd.see_other_uids=0
kern.ps_showallprocs=0
kern.ipc.maxsockbuf=4000000

# Enable stack protecttion
kern.elf32.nxstack=1
kern.elf64.nxstack=1

# IP security options
net.inet.ip.redirect=0
net.inet.ip.sourceroute=0
net.inet.ip.accept_sourceroute=0
net.inet.ip.random_id=1
net.inet.ip.portrange.first=9981
net.inet.ip.ttl=128

# TCP Security options
net.inet.tcp.sendspace=32768
net.inet.tcp.recvspace=32768
net.inet.tcp.sendbuf_max=16777216
net.inet.tcp.recvbuf_max=16777216
net.inet.tcp.path_mtu_discovery=0
net.inet.tcp.blackhole=2
net.inet.tcp.drop_synfin=1

# ICMP Security options
net.inet.icmp.drop_redirect=1
net.inet.icmp.maskrepl=0

# UDP Security options
net.inet.udp.recvbuf_max=16777216
net.inet.udp.blackhole=1

# Disable TSO in all interfaces
net.inet.tcp.tso=0