Date: Tue, 10 Oct 2006 13:38:43 -0300 From: "Eduardo Meyer" <dudu.meyer@gmail.com> To: stable@freebsd.org Subject: Netgraph - ng_bpf help (first experience) Message-ID: <d3ea75b30610100938k5fe929a7n3641b469b16c8bd1@mail.gmail.com>
next in thread | raw e-mail | index | archive | help
Hello,
I tried asking it on freebsd-ipfw@ but I got no luck. Maybe because
this is related to Netgraph and not ipfw essentially.
I want to use ng_bpf to use ng_tag to use ipfw-tag. Looks like lego,
where I have to assemble my toy, but I liked Lego when I was a child.
Following ng_bpf(4) man page I ran this script:
PATTERN="(ether[40:4]=0x134e5844 &&
ether[44:4]=0x6f6d6169 &&
ether[48:4]=0x6e0a)"
NODEPATH="my_node:"
INHOOK="hook1"
MATCHHOOK="hook2"
NOTMATCHHOOK="hook3"
cat > /tmp/bpf.awk << xxENDxx
{
if (!init) {
printf "bpf_prog_len=%d bpf_prog=[", \$1;
init=1;
} else {
printf " { code=%d jt=%d jf=%d k=%d }", \$1, \$2, \$3, \$4;
}
}
END {
print " ]"
}
xxENDxx
BPFPROG=`tcpdump -s 8192 -ddd ${PATTERN} | awk -f /tmp/bpf.awk`
ngctl msg ${NODEPATH} setprogram { thisHook=\"${INHOOK}\" \
ifMatch=\"${MATCHHOOK}\" \
ifNotMatch=\"${NOTMATCHHOOK}\" \
${BPFPROG} } }
But I got this message:
ngctl: send msg: No such file or directory
I printed the full commands that returns the error, it is:
ngctl msg setprogram { thisHook="" ifMatch="" ifNotMatch=""
bpf_prog_len=8 bpf_prog=[ { code=32 jt=0 jf=0 k=40 } { code=21 jt=0
jf=5 k=323901508 } { code=32 jt=0 jf=0 k=44 } { code=21 jt=0 jf=3
k=1869439337 } { code=32 jt=0 jf=0 k=48 } { code=21 jt=0 jf=1 k=28170
} { code=6 jt=0 jf=0 k=8192 } { code=6 jt=0 jf=0 k=0 } ] } }
Running tcpdump -s 8192 -ddd $PATTERN manually I get:
8
32 0 0 40
21 0 5 323901508
32 0 0 44
21 0 3 1869439337
32 0 0 48
21 0 1 28170
6 0 0 8192
6 0 0 0
Which looks that the ngctl data (code, kt, jf and k) are correct. But
the command returns that error for some reason. The script was taken
from ng_blf(4) man page.
I am all new to this netgraph thing.
Can anyone help me to find out what is rong? Thank you.
--
===========
Eduardo Meyer
pessoal: dudu.meyer@gmail.com
profissional: ddm.farmaciap@saude.gov.br
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?d3ea75b30610100938k5fe929a7n3641b469b16c8bd1>