nufw - NUFW User filtering gateway server
nufw [ -h ] [ -V ] [ -D ] [ -m ] [ -v[v...] ] [ -s ] [ -S ] [ -N ] [ -A
debug_area ] [ -k keyfile ] [ -c certfile ] [ -a cafile ] [ -r crlfile
] [ -n nuauth_cert_dn ] [ -d address ] [ -p (remote) port ] [ -t
timeout ] [ -T track_size ] [ -q NfQueue_num ] [ -L Nfqueue_length ] [
-C ] [ -M ]
This manual page documents the nufw command.
nufw is the minimalist server, designed to run on the gateway(s) of the
network. nufw is designed to run in conjunction with nuauth, the
authenticating server. nufw receives network packets from the local
firewall (on Linux 2.4 and 2.6, this is set up with the help of ’-j
NFQUEUE’ or ’-j QUEUE’ netfilter target), and synchronizes with a
nuauth server to check packet is authorized to travel through the
The design of the NUFW package lets administrator filter network
traffic per user, not only per IP. This means you can now deal with
different permissions for user A and user B, even if they work at the
same moment, on the same multiuser machine. In other words, this
extends firewalling criteria to userID, at the network scale.
Original packaging and informations and help can be found from
-h Issues usage details and exits.
-V Issues version and exits.
-D Run as a daemon. If started as a daemon, nufw logs message to
syslog. If you don’t specify this option, messages go to the
console nufw is running on, both on STDOUT and STDERR. Unless
you are debugging something, you should run nufw with this
-m Mark packets with UserID. This requires the wvmark POM patch
applied to netfilter, and is necessary for per user QoS or
-v Increases debug level. Multiple switches are accepted and each
of them increases the debug level by one. Default debug level is
2, max is 10.
Chooses debug_area. Default debug area is ALL. To select a
subset add value from the following list:
· DEBUG_AREA_MAIN (1) main domain
· DEBUG_AREA_PACKET (2) packet domain
· DEBUG_AREA_USER (4) user domain
· DEBUG_AREA_GW (8) Gateway domain, interaction with nufw
· DEBUG_AREA_AUTH (16) Authentication domain
Use specified file as SSL (private) key file.
Use specified file as SSL (public) certificate file.
Use specified file as SSL certificate authority file.
Use specified file as SSL certificate revocation list file. You
will need to restart nufw if you modify this file. Since 2.2.19,
nufw reloads this file dynamically when receiving a HUP signal.
Use specified string as the needed DN of nuauth. nufw will
refuse to connect if the provided string does not match the DN
of the certificate provided by nuauth. If you do not use this
option, the DN of the nuauth certificate will be checked against
the fully qualified domain name of the nuauth server, obtained
from a reverse DNS lookup on nuauth IP address.
-s Disable strict TLS checking of the certificate provided by
-S Force strict TLS checking of the certificate provided by nuauth.
This is the default behavior of the daemon since 2.2.18.
-N Suppress error if server FQDN does not match certificate CN.
Network address of the nuauth server.
Specifies TCP port to send data to when addressing the nuauth
server. Nuauth server must be setup to listen on that port.
Default value : 4128
Specifies timeout to forget packets not answered for by nuauth.
Default value : 15 s.
Set maximum number of packets that can wait a decision in nufw.
Default value : 1000.
-q NfQueue number
If Nufw was compiled with NfQueue support, Id of the NfQueue to
use (default : 0).
-L NfQueue length
Specify the length of the nfnetlink queue used by nufw. This is
the number of packets that the kernel will keep internally
before dropping new coming packets.
-C Listen to conntrack events (needed for connection expiration).
-M Only report event on marked connections to nuauth (implies -C
This is the way to do an efficient selection of events to be
sent to nuauth but this REQUIRES a kernel with transmit_mark
applied (should be ok for 2.6.18+) and the use of CONNMARK to
propagate the initial mark across all the packets of the
The nufw daemon is designed to deal with several signals : USR1, USR2,
SYS, WINCH and POLL.
USR1 Increases verbosity. The daemon then acts as if it had been
launched with one supplementary ’-v’.A line is also added to the
system log to mention the signal event.
USR2 Decreases verbosity. The daemon then acts as if it had been
launched with one less ’-v’. A line is also added to the system
log to mention the signal event.
SYS Removes the Conntrack events thread. This gets the daemon to
work as if the "-C" switch had not been set. This is useful on
HA configurations, when one firewall gets passive, for instance.
WINCH Starts the Conntrack events thread. This gets the daemon to work
as if the "-C" switch had been set at startup. This is useful on
HA configurations, when one firewall gets active, for instance.
POLL Logs an "audit" line, mentionning how many network datagrams
were received and sent since daemon startup.
Nufw was designed and coded by Eric Leblond, aka Regit
(<email@example.com>) , and Vincent Deffontaines, aka gryzor
(<firstname.lastname@example.org>). Original idea in 2001, while working on NSM
This manual page was written by Vincent Deffontaines
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 2 as
published by the Free Software Foundation; with no Invariant Sections,
no Front-Cover Texts and no Back-Cover Texts.
25 November 2008