Zyrianes / Adm

Mode AP pour ath5k avec Lenny

ludovic Bellier — 2011-01-29T20:38:47Z

Contents

Présentation
La carte wifi
- Description
- En mode client sous Debian
Le mode AP
Liens et articles annexes

Présentation

J'ai un Packard Bell Imax mini N3600 qui me sert de passerelle et de plateforme d'auto-hébergement sous Debian Lenny. Celui-ci possède une carte wifi qui ne me sert pas car la connectivité est fournie par ma connexion ADSL.

Je souhaite utiliser cette carte en tant que point d'accès Wifi, à la place de mon AP Linksys WRT54GL.

Pour ceux qui veulent les grandes lignes sans tout lire:

installer hostapd 0.6.10 de Squeeze
utiliser un noyau 2.6.32 de Lenny-backport
utiliser le guide Ath5k AP Mode d'Insignificant Bits.

La carte wifi

Description

Cette ordinateur inclut une carte wifi intégrée, il s'agit d'une Atheros AR2425 (168c:001c) qui fonctionne avec le driver ath5k:

# lspci -v -s 05:00.0
05:00.0 Ethernet controller:   Communications Inc. AR242x 802.11abg Wireless PCI Express Adapter (rev 01)
        Subsystem: AMBIT Microsystem Corp. Device 0428
        Flags: bus master, fast devsel, latency 0, IRQ 19
        Memory at febf0000 (64-bit, non-prefetchable) [size=64K]
        Capabilities: [40] Power Management version 2
        Capabilities: [50] Message Signalled Interrupts: Mask- 64bit- Queue=0/0 Enable-
        Capabilities: [60] Express Legacy Endpoint, MSI 00
        Capabilities: [90] MSI-X: Enable- Mask- TabSize=1
        Capabilities: [100] Advanced Error Reporting <?>
        Capabilities: [140] Virtual Channel <?>
        Kernel driver in use: ath5k
        Kernel modules: ath5k

Sortie de dmesg:

# dmesg
[   16.735520] ath5k 0000:05:00.0: PCI INT A -> Link[LN4A] -> GSI 19 (level, low) -> IRQ 19
[   16.735619] ath5k 0000:05:00.0: setting latency timer to 64
[   16.735706] ath5k 0000:05:00.0: registered as 'phy0'
...
[   19.006496] ath: EEPROM regdomain: 0x65
[   19.006503] ath: EEPROM indicates we should expect a direct regpair map
[   19.006513] ath: Country alpha2 being used: 00
[   19.006519] ath: Regpair used: 0x65
...
[   21.942054] phy0: Selected rate control algorithm 'minstrel'
[   21.943763] Registered led device: ath5k-phy0::rx
[   21.943869] Registered led device: ath5k-phy0::tx
[   21.943938] ath5k phy0: Atheros AR2425 chip found (MAC: 0xe2, PHY: 0x70)

En mode client sous Debian

Avant d'attaquer le mode AP, il faut valider le bon fonctionnement de la carte wifi avec le driver ath5k sur la Debian Lenny.

Pour cela le mieux est de l'utiliser en mode client, le mode le plus standard.

La page Debian ath5k peut vous être utile. Il faut vérifier que la carte est bien reconnue. Si l'OS ne charge pas tout seul le module ath5k, le charger et vérifier que la carte est reconnue, cf la sortie dmesg ci-dessus.

Est-ce que l'interface est bien créée, pour cela il suffit d'installer le package wireless-tools et vérifier la sortie de iwconfig, ici c'est l'interface wlan0 qui est en mode Managed:

# iwconfig
wlan0     IEEE 802.11bg  Mode:Managed  Access Point: Not-Associated
          Tx-Power=0 dBm
          Retry  long limit:7   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:off

Maintenant vous devez la configurer pour se connecter à votre réseau sans-fil (manuellement avec iwconfig, avec wicd ou autre gestionnaire de connexion).

Le mode AP

Description

Les cartes wifi possèdent plusieurs mode de fonctionnement, le plus classique est le mode client (mode Managed) pour se connecter à un réseau wifi.

Mais il existe de nombreux autres modes: le mode AP (Mode Master), le mode écoute (Mode Monitor) utiliser par des outils comme Kismet, le mode ad-hoc (Mode Ad-Hoc) pour faire un réseau direct entre clients sans AP...

Avec les wireless-tools

J'ai déjà utilisé le mode AP avec une carte PCI wifi avec le driver prism54g, il suffisait d'utiliser la commande iwconfig:

iwconfig wlan0 mode Master
iwconfig wlan0 essid test
iwconfig wlan0 key maclefWEP

Hélas, le driver ath5k ne supporte pas ce mode de configuration. Il faut donc passer par hostapd.

Installation d'hostapd

Il faut installer le package hostapd. Lenny propose la version 5.10 de hostapd qui est trop ancienne. En effet, il faut utiliser le driver nl80211 de hostapd, et cette version ne le supporte pas. Je comptais utiliser la version de lenny-backport, mais ... il n'y en a pas.

J'ai regardé les packages hostapd disponibles, et j'ai essayé celui de la squeeze. J'ai téléchargé le package:

wget http://ftp.fr.debian.org/debian/pool/main/h/hostapd/hostapd_0.6.10-2_i386.deb

et une tentative d'installation m'a indiqué deux conflits libnl1 et libssl. J'ai donc installé libnl1:

apt-get install libnl1

Je suis passé outre le conflit libssl car la version demandée était très proche de celle déjà installée (oui ce n'est pas bien). Donc j'ai forcé l'installation:

dpkg --force-depends-version -i hostapd_0.6.10-2_i386.deb

A noter qu'il est aussi souhaitable d'avoir un noyau >= 2.6.30. J'avais déjà un noyau de lenny-backport : linux-image-2.6.32-bpo.4-686.

Configuration d'hostapd

J'ai modifié le fichier /etc/defaut/hostapd pour indiquer le fichier de configuration:

DAEMON_CONF="/etc/hostapd/hostapd.conf"

Puis j'ai copié le fichier d'exemple:

cp /usr/share/doc/hostapd/examples/hostapd.conf.gz /etc/hostapd/
gunzip /etc/hostapd/hostapd.conf.gz

J'ai suivi le guide hostapd de mad-wifi. Il faut notamment utiliser le driver nl80211 de hostapd (basé sur la pile wifi mac80211 du noyau):

interface=wlan0
driver=nl80211
ssid=test

Puis lancer hostapd:

/usr/sbin/hostapd /etc/hostapd/hostapd.conf

Hélas le guide hostapd de mad-wifi est succinct, et je n'ai pas réussi à configurer correctement hostapd. J'avais un message d'incompatibilité matérielle.

Mon salut est venu du blog d'Insignificant Bits avec l'article Ath5k AP Mode qui est plus détaillé. J'avais oublié de configurer de nombreux paramètres (notamment le mode g au lieu de a), en WPA2:

hw_mode=g
channel=5
own_ip_addr=192.168.2.1
wpa=2
wpa_passphrase=MaClefWPA
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP
rsn_pairwise=CCMP

Puis un nouveau test, qui est passé:

# /usr/sbin/hostapd /etc/hostapd/hostapd.conf
Configuration file: /etc/hostapd/hostapd.conf
Using interface wlan0 with hwaddr 00:24:2c:78:xx:xx and ssid 'test'

Et la connexion d'un client:

wlan0: STA 00:1b:b1:48:xx:xx IEEE 802.11: authenticated
STA 00:1b:b1:48:xx:xx: No WPA/RSN IE in association request
wlan0: STA 00:1b:b1:48:xx:xx IEEE 802.11: authenticated
wlan0: STA 00:1b:b1:48:xx:xx IEEE 802.11: associated (aid 1)
wlan0: STA 00:1b:b1:48:xx:xx RADIUS: starting accounting session 4D44ACF5-00000000
wlan0: STA 00:1b:b1:48:xx:xx WPA: pairwise key handshake completed (RSN)

Il ne reste plus que des manipulations assez simples et très documentées: automatiser le lancement d'hostapd avec /etc/init.d/hostapd, configurer le serveur dhcp pour ce nouveau réseau, modifier la conf iptable pour le nat de ce réseau et le filtrage souhaité.

Je remercie Insignificant Bits pour son article Ath5k AP Mode.

Liens et articles annexes

Les caractéristiques du driver ath5k pour la carte Atheros AR2425 sur kernel.org
La page Debian ath5k.
Les packages hostapd chez Debian.
Le site officiel hostapd
Le site hostapd de kernel.org
Le site hostapd de mad-wifi
Le guide Ath5k AP Mode d'Insignificant Bits.

Home + Sharp + return

ludovic Bellier — 2008-03-22T14:19:02Z

The shortcut that I never remember:
Esc + # (Meta + #)
With Bash, comment the line and go to next line

Very Simple Test Download via a Proxy Howto

ludovic Bellier — 2007-11-18T22:00:13Z

This simple howto explains howto to check your download rate through a ft proxy

private Proxy
=============

If it's a private proxy, first create a tunnel to this proxy with ::

ssh -l -L 3128:localhost:3128

Next, configure your proxy::

export ftp_proxy=localhost:3128

Finally, test your dl with wget::

wget --verbose --proxy=on \\
ftp://ftp.free.fr/mirrors/ftp.ubuntu.com/releases/7.10/ubuntu-7.10-desktop-i386.iso

You can check if your traffic uses the proxy with iftop, example::

iftop -i eth0

public or internal Proxy
========================

You just set your proxy host/port and launch wget::

export ftp_proxy=localhost:3128
wget --verbose --proxy=on \\
ftp://ftp.free.fr/mirrors/ftp.ubuntu.com/releases/7.10/ubuntu-7.10-desktop-i386.iso

Navibe GM720 : setting and using with Linux

ludovic Bellier — 2007-07-29T15:19:50Z

I recently buy an USB GPS, also called GPS Mouse, Navibe GM720 on eBay. I'll use it with Linux on my Apple iBook G4.

Contents

Hardware
- GPS
- Computer
Setting
- Hardware ID
- Setting an USB GPS with Linux
Using
iBook with Gentoo and GPS use
Thanks

Hardware

GPS

The Navibe GM720 uses a USB-to-Serial converter from Prolific. The GPS chipset is the SiRF Star III, a recent and famous chipset used in numerous current GPS receivers.

Computer

I use an Apple iBook G4 with Gnu/Linux Gentoo PPC distribution. This 12" iBook is small enough, I can put it in a back bag and the battery allows 3-4 endurance hours.

Setting

Hardware ID

lsusb only shows the USB-to-Serial converter:

# lsusb 
Bus 003 Device 002: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port

cgps reports: SiRF binary GSW3.2.0PAT_3.

Setting an USB GPS with Linux

A lot of these (all?) USB GPS use the Prolific USB-to-Serial converter. So your kernel needs the pl2303 driver.

Linux kernel setting (here v2.6.23-rc1):

Device Drivers  --->
 [*] USB support  --->
  USB Serial Converter support  --->
   <M> USB Serial Converter support
   <M>   USB Prolific 2303 Single Port Serial Driver

When you plug your USB GPS, you see in /var/log/messages:

Jul 29 17:23:40 iyn usb 3-1: new full speed USB device using ohci_hcd and address 3
Jul 29 17:23:40 iyn usb 3-1: configuration #1 chosen from 1 choice
Jul 29 17:23:40 iyn pl2303 3-1:1.0: pl2303 converter detected
Jul 29 17:23:40 iyn usb 3-1: pl2303 converter now attached to ttyUSB0

If none, verify if the pl2303 module is loaded, with the command lsmod:

# lsmod | grep pl2303
pl2303                 21956  0

If none, the command:

insmod pl2303

loads the module.

You see that the GPS can be accessed with the ttyUSB0 serial device, so I'll use the /dev/ttyUSB0 device name.

Using

Verify you can access your GPS

The gpsd suite has the sirfmon utility which communicates with the GPS through the serial port (or through gpsd, see below).

Starts it with:

sirfmon /dev/ttyUSB0

This software displays on top the informations received from the GPS and on bottom the raw communication with the GPS.

GPSd

The gpsd daemon is an abstraction layer. It communicates through the physical serial port GPS and offers services (lat, long, ...) to its clients (cgps, sirfmon, gpsdrive, navit, ...).

A lot of Linux applications use it, and it is ported to Open/Free/NetBSD and Mac OS X.

It's very simple, just start the daemon with

gpsd /dev/ttyUSB0

If you want to kill it, use the killall gpsd command.

FYI: gpsd installs the usb hotplug rules.

The gpsd suite has a lot of very usefull tools.

Gpsd tools : sirfmon

sirfmon is a SiRF Star III chipset specific tool, it displays a lot of advanced information from this specific chipset class GPS. It'a a textual tool.

Start gpsd if not yet done, and just:

sirfmon

and sirfmon will use gpsd to get geographic informations, see this Sirfmon screenshot:

Gpsd tools : cgps

cgps is also a text tool which displays useful geographic informations, but it isn't specific to one chipset class GPS. See this cgps screenshot:

Gpsd tools : xgps

It's same as cgps but with a graphic interface.

Gpsd tools : cgpxlogger

cgpxlogger is a gps data logger, it displays GPS informations, in GPX format.

Use example:

# cgpxlogger > 2007-07-29_20h08.gpx

and Ctrl-c stop it.

GPX is one of the most known gps data logger format, a lot of applications use it. It's a good solution if you want trace your way or help the OSM project.

GpsDrive

gpsdrive is a car navigation system for laptops. It can download maps from Expedia or TopoZone. See this Gps Drive screenshot:

Navit

navit is a car navigation system for laptops and embedded touch screen displays. For the installation, you need some specific libraries: cegui with openGL support and quesoglc. See this Navit installation page from the project. This is a promising project.

OpenStreetMap

OSM is a collaborative editable map. Most of the current maps have restrictive rights, this project allows each person with a GPS to upgrade the OSM map. Some softwares (like Navit) can use this non-commercial Map. See the current OSM Map.

iBook with Gentoo and GPS use

/etc/init.d/pbbuttonsd stop deactivates the suspend to ram process, when you close your laptop or after 5mn of inactivity, so you can log your GPS way with cgpxlogger, and import it to OSM.

Thanks

gpsd developers, Gwenn, Jkx.

Screen tips

ludovic Bellier — 2005-05-19T12:03:08Z

screen is a unix command that manages few virtual terminals.

Splitting the screen

Start screen with few terminals and use C-a S for splitting the current view. C-a TAB allows moving from one to another view.

So:

C-a S split the screen
C-a TAB move to another view

man page: http://www.sunsite.ualberta.ca/Documentation/Gnu/screen-3.9.4/html_chapter/screen_toc.html

Thanks to Gwenn aka demisel.

TightVNC and VNC_VIA_CMD

ludovic Bellier — 2005-05-16T21:41:19Z

TightVNC has a '-via' option that allows using a gateway through the client and the VNC server.

TightVNC with this option can use a 'host in the middle' (gateway) to access another host. The VNC_VIA_CMD defines the ssh options to access the gateway.

Example:

host A access host C through host B. A and B have a public IP, but C is behind B. 
A can access B with ssh.
export VNC_VIA_CMD='/usr/bin/ssh -2 -x -p <B sshd port> -l <B user> -f -L %L:%H:%R %G sleep 20'
vncviewer -via  <B host ip> <C host IP from B>

true life example:

foo --> gateway.bar.com --> 192.168.1.36
foo> export VNC_VIA_CMD='/usr/bin/ssh -2 -x -p 55 -l foo -f -L %L:%H:%R %G sleep 20'
foo> vncviewer -via  gateway.bar.com 192.168.1.36

links :

http://www.vanemery.com/Linux/VNC/vnc-over-ssh.html

charcode test:

148

ludovic Bellier — 2004-12-01T17:10:29Z

CODE

Qmail tips

ludovic Bellier — 2004-09-26T13:52:23Z

Contents

Repair the queue
Setup as MX secondary for a domain
Watch qmail logs with date/time

This short article enumerates tips for qmail (a reminder for me):

Repair the queue

The queue is located here : /var/qmail/queue/ , you can repair it with queue_repair ( http://www.qcc.ca/~charlesc/software/queue_repair/ ).

command:

./queue_repair.py -c -s 23 --no-bigtodo /var/qmail

see: http://www.qcc.ca/~charlesc/software/queue_repair/docs.html#docs -c create and repair -s 23 number of split directories --no-bigtodo if your qmail don't use the qmail big-todo patch

Setup as MX secondary for a domain

It's quite simple, add the domain in the /var/qmail/control/rcpthosts of each recorded MX secondary. And, restarts qmail (just kill -HUP).

exemple:

server1.domain1.tld has:
MX   10 server1.domain1.tld
MX   20 server2.domain2.tld

on server2.domain2.tld,
in /var/qmail/control/rcpthosts file add line:
server1.domain1.tld

Watch qmail logs with date/time

Qmail use a special log format for the date and the time (maybe seconds number since 1/1/1970 ). tai64nlocal shows user fiendly date/time.

exemple:

# tail -f /var/log/qmail/current  | tai64nlocal
2005-02-10 14:07:55.565508500 delivery 3973: success: did_1+0+0/
2005-02-10 14:07:55.565510500 status: local 0/10 remote 0/20
2005-02-10 14:07:55.565511500 end msg 52055
2005-02-10 14:27:01.610629500 new msg 52055

nmap

ludovic Bellier — 2004-09-23T10:17:29Z

Nmap 3.70 released -> http://www.insecure.org/

this simple command allows to know which local hosts are up:

nmap -sP <masked IP network>   (ex: nmap -sP 192.168.1.0/24 )

This friendly scanning can be added to the crontab, allowing a daily report of the open ports:

nmap -sT -P0 -sV <host> 2>&1 | mail -b <your mail> \
 -s "[nmap] `date -I` scan report" <host_owner_mail>

For IPv6:

nmap -sT -6 -P0 -sV <host|ipv6>

A mail per valid SSH session

ludovic Bellier — 2004-08-06T22:02:31Z

You want to be notified when someone connects on your server with ssh? Add this sshrc config file to your ssh config directory (/etc/ssh):

emailfrom=root@`hostname`
emailto=<_your address here_>
fulluser="$USER@"`hostname`
date822=`date -R`
ldate=`date "+%A %e %B %Y a %Hh%M %Z"`
host_ip="`echo $SSH_CONNECTION | awk '{print $1}'`"
host_dns="`host ${host_ip}`"

echo -e "\
From: $emailfrom
To: $emailto
Subject: [SSHRC] ssh session - $USER
Date: $date822
User-Agent: sshrc
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-15; format=flowed
Content-Transfer-Encoding: 8bit
Hello,

A ssh session version $SHLVL opened,
with local user $fulluser,
$ldate,
from host  $SSH_CONNECTION.
host DNS : $host_dns


- -- 
sshrc" | /usr/sbin/sendmail -t

Add your email to the emailto variable, test and modify to your needs.

Thanks to Léa for her ssh post on this.