You are running a program that requires the Berkeley Packet Filter ( bpf(4)), but it's not in your kernel. Add this to your kernel config file and build a new kernel:
pseudo-device bpf # Berkeley Packet Filter
After rebooting, create the device node. This can be accomplished by going to the /dev directory and running:
# sh MAKEDEV bpf0
Please see the Handbook entry on device nodes for more information on creating devices.