utils: nfbpf_compile

A BPF compiler to convert tcpdump expressions to the decimal format
accepted by the libxt_bpf.

Generate a file and pass that to iptables:

  nfbpf_compile RAW 'udp dst port 9000' > test.bpf
  iptables -A OUTPUT -m bpf --bytecode-file test.bpf -j LOG

Or pass the output directly to iptables using backticks:

  iptables -A INPUT -m bpf --bytecode \
      "`./nfbpf_compile RAW 'udp dst port 9000'" -j LOG

This utility depends on libpcap. The library is only compiled if the option
--enable-bpf-compiler is explicitly passed to ./configure and libpcap is
found.

Pablo has mangled the original patch to rename the utility to
nfbpf_compile. Also modified the output to match exactly what
-m bpf --bytecode needs.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 0 insertions, 2 deletions

diff --git a/Makefile.am b/Makefile.am
index 6400ba41..c38d3600 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -10,9 +10,7 @@ endif
 if ENABLE_LIBIPQ
 SUBDIRS         += libipq
 endif
-if HAVE_LIBNFNETLINK
 SUBDIRS         += utils
-endif
 # Depends on libxtables:
 SUBDIRS         += extensions
 # Depends on extensions/libext.a: