ZsZs IT

Saturday, February 23, 2013

Debricking Seagate Dockstar

Somehow I managed to brick my Dockstar. It was so simple like the first sentence :) The debricking process was quite long due to lack of experience and tools. Tools required:
- A buspirate card (I have a v3.6)
- openocd with buspirate support
- An USB2serial converter (3.3V version!) . Tip: search "CP2102 usb serial" on Ebay. You'll get tons for a few bucks.
1. Upgrade your BusPirate 3.x to at least 6.0RC fw version to have an openocd capable firmware on your buspirate.
2. Connect the ingredients according to this schematic. My "setup":

3. Download boot image and make a symlink to it:

# wget http://jeff.doozan.com/debian/uboot/files/uboot/uboot.mtd0.dockstar.jeff-2010-10-23.kwb
# ln -s uboot.mtd0.dockstar.jeff-2010-10-23.kwb uboot.kwb

4. Download docstar.cfg and change the start of the config from

# I'm using a wiggler compatible cable
source [find interface/buspirate.cfg]
source [find target/feroceon.cfg]
jtag_khz 500
jtag_nsrst_delay 500

interface buspirate
source [find target/feroceon.cfg]
buspirate_port /dev/ttyUSB0
buspirate_speed fast
buspirate_vreg 0
reset_config srst_only
adapter_khz 500

5. Connect Buspirate'c USB port to your USB port and start openocd on Terminal #1:

# openocd -f ./dockstar.cfg
Open On-Chip Debugger 0.7.0-dev-00079-g08ddb19 (2012-12-02-23:14)
Licensed under GNU GPL v2
For bug reports, read
        http://openocd.sourceforge.net/doc/doxygen/bugs.html
Warn : Adapter driver 'buspirate' did not declare which transports it allows; assuming legacy JTAG-only
Info : only one transport option; autoselect 'jtag'
trst_and_srst separate srst_gates_jtag trst_push_pull srst_open_drain
adapter_nsrst_delay: 200
jtag_ntrst_delay: 200
srst_only separate srst_gates_jtag srst_open_drain
adapter speed: 500 kHz
Warn : use 'feroceon.cpu' as target identifier, not '0'
dockstar_reset_cpu
Info : Buspirate switched to FAST mode
Info : Buspirate Interface ready!
Info : Want to set speed to 500kHz, but not implemented yet
Error: Translation from jtag_speed to khz not implemented
Info : adapter-specific clock speed value 500
Info : JTAG tap: feroceon.cpu tap/device found: 0x20a023d3 (mfg: 0x1e9, part: 0x0a02, ver: 0x2)
Info : Embedded ICE version 0
Info : feroceon.cpu: hardware has 1 breakpoint/watchpoint unit

You can minimize this terminal because you do not need to watch this
6. Open Terminal #2 and connect to openocd:

# telnet localhost 4444
Trying ::1...
telnet: connect to address ::1: Connection refused
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
Connection closed by foreign host.
[root@centos6 ~]# telnet localhost 4444
Trying ::1...
telnet: connect to address ::1: Connection refused
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
Open On-Chip Debugger
>

7. On Terminal #2 issue following commands:

> init
> soft_reset_halt
requesting target halt and executing a soft reset
target state: halted
target halted in ARM state due to debug-request, current mode: Supervisor
cpsr: 0x000000d3 pc: 0x00000000
MMU: disabled, D-Cache: disabled, I-Cache: disabled
> dockstar_init
> load_image uboot.kwb 0x800000
524288 bytes written at address 0x00800000
downloaded 524288 bytes in 108.139221s (4.735 KiB/s)

Update: The trick was to issue "soft_reset_halt" instead of "halt". There are a few guides which operates with halt command and immediate press reset button. With "soft_reset_halt" no need to be lucky with reset button. You don't have to press it.
Halt command lead my Dockstar to "target halted in Thumb state", which wasn't enough to access the NAND.
8. Check NAND on Terminal #2:

> nand probe 0
NAND flash device 'NAND 256MiB 3.3V 8-bit (Micron)' found
> nand list
#0: NAND 256MiB 3.3V 8-bit (Micron) pagesize: 2048, buswidth: 8,
        blocksize: 131072, blocks: 2048
> nand check_bad_blocks 0
checked NAND flash device for bad blocks, use "nand info" command to list blocks

9. Open Terminal #3 and connect it to Dockstar's serial port via USB2Serial adapter
10. On Terminal #2 issue following connmmand and be prepared co switch to Termianl #3 within 3 seconds and press a key to stop boot process.

> resume 0x800200

11. Switch to Termnal #3 and press a key to stop boot process:

U-Boot 2010.09 (Oct 23 2010 - 11:49:22)
Marvell-Dockstar/Pogoplug by Jeff Doozan

SoC:   Kirkwood 88F6281_A0
DRAM:  128 MiB
NAND:  256 MiB
*** Warning - bad CRC or NAND, using default environment

In:    serial
Out:   serial
Err:   serial
Net:   egiga0
88E1116 Initialized on egiga0
Hit any key to stop autoboot:  0
Marvell>>

12. Write uBoot into NAND on Terminal #3:

Marvell>> nand erase

NAND erase: device 0 whole chip
Erasing at 0xffe0000 -- 100% complete.
OK
Marvell>> nand write.e 0x800000 0x0 0x80000

NAND write: device 0 offset 0x0, size 0x80000
 524288 bytes written: OK
Marvell>> reset
resetting ...

You are Done!
+1 Extra steps to write rescue image to NAND
Download rescue images and put them to a local TFTP server:
http://jeff.doozan.com/debian/rescue/uImage-mtd1.img
http://jeff.doozan.com/debian/rescue/rootfs-mtd2.img
On Terminal #3 stop the boot process and issue following commands:

Marvell>> setenv ipaddr 192.168.A.B
Marvell>> setenv serverip 192.168.A.C
Marvell>> setenv ethaddr 00:10:75:XX:XX:XX
Marvell>> saveenv
Saving Environment to NAND...
Erasing Nand...
Erasing at 0xc0000 -- 100% complete.
Writing to Nand... done
Marvell>> ping 192.168.A.C
Using egiga0 device
host 192.168.A.C is alive
Marvell>> nand erase 0x100000 0x400000

NAND erase: device 0 offset 0x100000, size 0x400000
Erasing at 0x4e0000 -- 100% complete.
OK
Marvell>> tftp 0x800000 uImage-mtd1.img
Using egiga0 device
TFTP from server 192.168.248.254; our IP address is 192.168.248.199
Filename 'uImage-mtd1.img'.
Load address: 0x800000
Loading: #################################################################
         #################################################################
         #################################################################
         ########################################################
done
Bytes transferred = 3670016 (380000 hex)
Marvell>> nand write.e 0x800000 0x100000 0x380000

NAND write: device 0 offset 0x100000, size 0x380000
 3670016 bytes written: OK
Marvell>> tftp 0x1000000 rootfs-mtd2.img
Using egiga0 device
TFTP from server 192.168.248.254; our IP address is 192.168.248.199
Filename 'rootfs-mtd2.img'.
Load address: 0x1000000
Loading: #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         ########################
done
Bytes transferred = 28966912 (1ba0000 hex)
Marvell>> setenv rescue_set_bootargs 'setenv bootargs console=$console ubi.mtd=2 root=ubi0:rootfs ro rootfstype=ubifs $mtdparts $rescue_custom_params'
Marvell>> setenv rescue_bootcmd 'if test $rescue_installed -eq 1; then run rescue_set_bootargs; nand read.e 0x800000 0x100000 0x400000; bootm 0x800000; else run pogo_bootcmd; fi'
Marvell>> setenv bootcmd 'run bootcmd_usb; usb stop; run rescue_bootcmd; reset'
Marvell>> saveenv
Saving Environment to NAND...
Erasing Nand...
Erasing at 0xc0000 -- 100% complete.
Writing to Nand... done
Marvell>> run rescue_bootcmd

NAND read: device 0 offset 0x100000, size 0x400000
 4194304 bytes read: OK
## Booting kernel from Legacy Image at 00800000 ...
   Image Name:   Linux-2.6.32.18-dockstar
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    3236180 Bytes = 3.1 MiB
   Load Address: 00008000
   Entry Point:  00008000
   Verifying Checksum ... OK
   Loading Kernel Image ... OK
OK

Starting kernel ...

Uncompressing Linux............................................................................................................................................................................................................. done, booting the kernel.
[    0.000000] Initializing cgroup subsys cpuset
[    0.000000] Initializing cgroup subsys cpu
[    0.000000] Linux version 2.6.32.18-dockstar (root@stfu.tcbnet) (gcc version 4.3.5 (Buildroot 2010.08) ) #1 Thu Feb 17 03:09:57 EST 2011
[    0.000000] CPU: Feroceon 88FR131 [56251311] revision 1 (ARMv5TE), cr=00053977
[    0.000000] CPU: VIVT data cache, VIVT instruction cache
[    0.000000] Machine: Marvell SheevaPlug Reference Board
[    0.000000] Memory policy: ECC disabled, Data cache writeback
[    0.000000] Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 32512
[    0.000000] Kernel command line: console=ttyS0,115200 ubi.mtd=2 root=ubi0:rootfs ro rootfstype=ubifs mtdparts=orion_nand:1M(u-boot),4M(uImage),32M(rootfs),-(data)
[    0.000000] PID hash table entries: 512 (order: -1, 2048 bytes)
[    0.000000] Dentry cache hash table entries: 16384 (order: 4, 65536 bytes)
[    0.000000] Inode-cache hash table entries: 8192 (order: 3, 32768 bytes)
[    0.000000] Memory: 128MB = 128MB total
[    0.000000] Memory: 122836KB available (5968K code, 708K data, 128K init, 0K highmem)
[    0.000000] SLUB: Genslabs=11, HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
[    0.000000] Hierarchical RCU implementation.
[    0.000000] NR_IRQS:114
[    0.000000] Console: colour dummy device 80x30
[    0.000123] Calibrating delay loop... 1192.75 BogoMIPS (lpj=5963776)
[    0.240079] Security Framework initialized
[    0.240098] SELinux:  Disabled at boot.
[    0.240118] Mount-cache hash table entries: 512
[    0.240368] Initializing cgroup subsys ns
[    0.240381] Initializing cgroup subsys cpuacct
[    0.240390] Initializing cgroup subsys devices
[    0.240399] Initializing cgroup subsys freezer
[    0.240406] Initializing cgroup subsys net_cls
[    0.240438] CPU: Testing write buffer coherency: ok
[    0.240988] devtmpfs: initialized
[    0.242412] regulator: core version 0.5
[    0.242586] NET: Registered protocol family 16
[    0.242971] Kirkwood: MV88F6281-A0, TCLK=200000000.
[    0.242983] Feroceon L2: Cache support initialised.
[    0.246010] bio: create slab  at 0
[    0.246292] vgaarb: loaded
[    0.246568] SCSI subsystem initialized
[    0.246822] usbcore: registered new interface driver usbfs
[    0.246888] usbcore: registered new interface driver hub
[    0.246977] usbcore: registered new device driver usb
[    0.247423] Switching to clocksource orion_clocksource
[    0.252761] NET: Registered protocol family 2
[    0.253024] IP route cache hash table entries: 1024 (order: 0, 4096 bytes)
[    0.253840] TCP established hash table entries: 4096 (order: 3, 32768 bytes)
[    0.253939] TCP bind hash table entries: 4096 (order: 2, 16384 bytes)
[    0.253992] TCP: Hash tables configured (established 4096 bind 4096)
[    0.254001] TCP reno registered

Thursday, February 7, 2013

Backup multiple pfSense 2.x

Recently I've installed some pfSense firewalls and looked around how to backup their config.

I found this on pfsense.org, but I improved the idea because I would like to:

backup more than one firewall without changing the script
push something useful about config change to syslog
properly log out and do not leave the admin session alive
retain previous config files if something strange happens :)

I wrote pfsensecfgarch.sh:

#!/bin/bash
# Download the actual config.xml from pfSense firewall and archive it, if it has changed
# Read config file in following format
# host=host1;username;password
# host=host2;username;password
#
# ZsZs 2013

cfgfile=pfsensecfgarch.cfg
backupdirpfx=config
tmpdir=tmp

[ -d $tmpdir ] || mkdir -p $tmpdir
scr=${0##*/}
loginf() { logger -t "$scr" -p "info" "$@"; }
logerr() { logger -t "$scr" -p "error" "$@"; }
cleanup() { /bin/rm $curlerr 2>/dev/null; /bin/rm $cookiefile 2>/dev/null; }

[[ ! -f $cfgfile ]] && { logerr "Missing config file: $cfgfile"; exit 1; }
for cfgline in $(egrep "^host=" $cfgfile | cut -d= -f 2-)
do
  echo $cfgline | while IFS=';' read -r host user passwd rest
  do
    [ ! -z "$rest" ] && { echo "Invalid line in $cfgfile: $(grep "$cfgline" $cfgfile)"; exit 1; }
    # Login and store sessionid in cookie file
    cookiefile=$(mktemp)
    curlerr=$(mktemp)
    curl -s -S --data-ascii "login=Login&usernamefld=$user&passwordfld=$passwd" -k https://$host/diag_backup.php -o /dev/null -c $cookiefile 2>$curlerr \
      || { logerr "[$host]: login: $(cat $curlerr)"; cleanup; exit 1; }
    backupdir=$backupdirpfx/$host
    [ -d $backupdir ] || mkdir -p $backupdir
    # Download actual config
    curl -s -S --data-ascii 'Submit=download&donotbackuprrd=yes' -k https://$host/diag_backup.php -o $backupdir/config.xml.tmp -b $cookiefile 2>$curlerr \
      || { logerr "[$host]: download: $(cat $curlerr)"; cleanup; exit 1; }
    # Logout
    curl -s -S -k "https://$host/index.php?logout" -o /dev/null -b $cookiefile 2>$curlerr \
      || { logerr "[$host]: logout: $(cat $curlerr)"; cleanup; exit 1; }
    if [ "$?" == "0" ]; then
      # Check for change
      diff $backupdir/config.xml.tmp $backupdir/config.xml.latest 2>/dev/null >/dev/null
      # Archive previous config if the new one is different
      if [ "$?" != "0" ]; then
        if [ -f $backupdir/config.xml.latest ]; then
          mv $backupdir/config.xml.latest $backupdir/config.xml.$(date "+%Y%m%d-%H%M%S") 2>/dev/null
          mv $backupdir/config.xml.tmp $backupdir/config.xml.latest 2>/dev/null
        else
          mv $backupdir/config.xml.tmp $backupdir/config.xml.latest 2>/dev/null
        fi
        loginf "[$host]: updated"
      fi
      /bin/rm $backupdir/config.xml.tmp 2>/dev/null
    fi
    cleanup
  done
done

This script should be run from cron approximately every hour.
Comments welcome!

Wednesday, December 12, 2012

Dovecot -> MySQL SElinux issue on CentOS6

I set up a postfix, dovecot, mysql, postfixadmin combo on SElinux enabled CentOS6, but I was keep getting following error in mail.log:

dovecot: dict: Error: mysql: Connect failed to localhost (mail): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (13) - waiting for 1 seconds before retry

The problem is that Selinux prevents dovecot connecting to mysql socket. I was unable to find simple solution by setting some setsebol parameter, so I went through the audit.log with audit2allow.

Solution:

Create dovecot2mysql.te file under /etc/selinux:

cat > /etc/selinux/dovecot2mysql.te
module dovecot2mysqldb 1.0.0;

require {
    type dovecot_t;
    type dovecot_deliver_t;
    type var_t;
    type mysqld_db_t;
    type mysqld_t;
    type mysqld_var_run_t;
    type usr_t;
    class file { rename read create write getattr link unlink open };
    class dir search;
    class unix_stream_socket connectto;
    class sock_file write;
    class file { read getattr open };
}


allow dovecot_deliver_t var_t:file { rename read create write getattr link unlink open };
allow dovecot_t mysqld_db_t:dir search;
allow dovecot_t mysqld_t:unix_stream_socket connectto;
allow dovecot_t mysqld_var_run_t:sock_file write;
allow dovecot_t usr_t:file { read getattr open };


cat >/etc/selinux/sel.sh <<EOF
name=\${1%%.*}
echo "\$name"
checkmodule -M -m -o \$name.mod \$name.te \
  && semodule_package -o \$name.pp -m \$name.mod \
  && /usr/sbin/semodule -i \$name.pp
EOF

chmod 700 /etc/selinux/sel.sh
/etc/selinux/sel.sh /etc/selinux/dovecot2mysql.te

Tuesday, November 20, 2012

djndns on CentOS6

I use DJB's dns package for a long time and I am satisfied with it. Recently I started migrating it to a CentOS6 machine.
My new requirements were following:

run services from init script
collect log messages by syslog-ng
have config files under /etc

There are a few guides on the net but they use DJB's svscan service to start-stop djb services and they use multilog as log collector.
There is my guide to achieve my requirements:
Install prerequisites (build environment):

yum install gcc make

Build daemontools

cd /usr/local/src
wget http://cr.yp.to/daemontools/daemontools-0.76.tar.gz
tar xvfz daemontools-0.76.tar.gz
cd admin/daemontools-0.76
sed -i '/gcc/ s|$| -include /usr/include/errno.h|' src/conf-cc
package/compile
for i in $(cat package/commands); do cp command/$i /usr/local/bin/$i; done

Build ucspi-tcp

cd /usr/local/src
wget http://cr.yp.to/ucspi-tcp/ucspi-tcp-0.88.tar.gz
tar xvfz ucspi-tcp-0.88.tar.gz
cd ucspi-tcp-0.88
sed -i '/gcc/ s|$| -include /usr/include/errno.h|' conf-cc
make
make setup check

Build djbdns

cd /usr/local/src
wget http://cr.yp.to/djbdns/djbdns-1.05.tar.gz
tar xvfz djbdns-1.05.tar.gz
cd djbdns-1.05
sed -i '/gcc/ s|$| -include /usr/include/errno.h|' conf-cc
make
make setup check

UPDATE:

Add /usr/local/bin to your PATH:

sed -i '/PATH=/ s|$|:/usr/local/bin|' /root/.bash_profile

Re-login or simply add to bash session:

export PATH=$PATH:/usr/local/bin

dnscache

Create dnscache users

groupadd -g 200 djbdns
useradd --no-create-home -s /bin/false -u 201 -g 200 dnscache
useradd --no-create-home -s /bin/false -u 202 -g 200 dnslog

Setup dnscache

dnscache-conf dnscache dnslog /etc/dnscache 192.168.233.254

Specify client's address range

touch /etc/dnscache/root/ip/192.168.233

Create init script

cat >/etc/init.d/dnscache <<EOF
#!/bin/bash
#
# dnscache      DNS cache server
#
# chkconfig: 345 11 89
# Provides: dnscache
# Required-Start: \$network
# Required-Stop: \$network
# Short-Description: start and stop dnscache
# Description: Dan Bernstein (DJB) dns cache server
# ZsZs
 
# Source function library.
. /etc/rc.d/init.d/functions
 
prog=dnscache
progdir=/usr/local/bin
 
# pull in sysconfig settings
[ -f /etc/sysconfig/dnscache ] && . /etc/sysconfig/dnscache
 
start(){
    echo -n \$"Starting \$prog: "
    pid=\$(pidof \$progdir/\$prog)
    if [[ "\$pid" == "" ]]; then
        # Read up dnscache environment files and export them
        for env in \$(cd \$dnscachedir/env/; ls -1); do envs="\$envs \$env=\$(cat \$dnscachedir/env/\$env)"; done
        export \$envs
        \$progdir/envuidgid dnscache \$progdir/softlimit -o250 -d "\$DATALIMIT" \
          \$progdir/\$prog 2>&1 | (\$progdir/setuidgid dnslog /usr/bin/logger -p local4.info -t \$prog) &
        if [[ "\$?" == "0" ]]
        then
            success
            echo
        else
            failure \$"\$prog start"
            echo
            exit 1
        fi
    else
        failure \$"\$prog start"
        echo
        exit 1
    fi
}
 
stop(){
    pid=\$(pidof \$progdir/\$prog)
    if [[ "\$pid" == "" ]]
    then
        echo -n "Stopping  \$prog: "
        failure \$"\$prog not running."
        echo
    else
        echo -n "Stopping \$prog: "
        kill \$pid && success || failure \$"\$prog stop"
        echo
    fi
}
 
# See how we were called.
case "\$1" in
    start)
        start
        ;;
    stop)
        stop
        ;;
    restart)
        stop
        sleep 1
        start
        ;;
    *)
        echo "Usage: \$prog {start|stop|restart}"
        exit 1
esac
 
exit 0
EOF

Create dnscache config file

echo "dnscachedir=/etc/dnscache" >/etc/sysconfig/dnscache

Start dnscache service

chmod 755 /etc/init.d/dnscache
service dnscache start
chkconfig dnscache on

tinydns

Create tinydns users

useradd --no-create-home -s /bin/false -u 203 -g 200 tinydns
useradd --no-create-home -s /bin/false -u 204 -g 200 tinylog

Install tinydns

tinydns-conf tinydns tinylog /etc/tinydns your.pub.lic.ip
cd /etc/tinydns/root

Create example domain Add SOA record

./add-ns example.hu 123.123.123.123

Add host

./add-host garfield.examle.hu 123.123.123.124

Add MX record

./add-mx examle.hu 123.123.123.123

Add alias

./add-alias www.example.hu 123.123.123.123

Make data.cdb

make

Create init script

cat >/etc/init.d/tinydns <<EOF
#!/bin/bash
#
# tinydns      Authoritative DNS server
#
# chkconfig: 345 11 89
# Provides: tinydns
# Required-Start: \$network
# Required-Stop: \$network
# Short-Description: start and stop tinydns
# Description: Dan Bernstein (DJB) authoritative dns server
# ZsZs
 
# Source function library.
. /etc/rc.d/init.d/functions
 
prog=tinydns
progdir=/usr/local/bin
 
# pull in sysconfig settings
[ -f /etc/sysconfig/tinydns ] && . /etc/sysconfig/tinydns
 
start(){
    echo -n \$"Starting \$prog: "
    pid=\$(pidof \$progdir/\$prog)
    if [[ "\$pid" == "" ]]; then
        # Read up tinydns environment files and export them
        for env in \$(cd \$tinydnsdir/env/; ls -1); do envs="\$envs \$env=\$(cat \$tinydnsdir/env/\$env)"; done
        export \$envs
        \$progdir/envuidgid tinydns \$progdir/softlimit -d300000 \$progdir/\$prog 2>&1 | \
          (\$progdir/setuidgid tinylog /usr/bin/logger -p local4.info -t \$prog) &
        if [[ "\$?" == "0" ]]
        then
            success
            echo
        else
            failure \$"\$prog start"
            echo
            exit 1
        fi
    else
        failure \$"\$prog start"
        echo
        exit 1
    fi
}
 
stop(){
    pid=\$(pidof \$progdir/\$prog)
    if [[ "\$pid" == "" ]]
    then
        echo -n "Stopping  \$prog: "
        failure \$"\$prog not running."
        echo
    else
        echo -n "Stopping \$prog: "
        kill \$pid && success || failure \$"\$prog stop"
        echo
    fi
}
 
# See how we were called.
case "\$1" in
    start)
        start
        ;;
    stop)
        stop
        ;;
    restart)
        stop
        sleep 1
        start
        ;;
    *)
        echo "Usage: \$prog {start|stop|restart}"
        exit 1
esac
 
exit 0
EOF

Create tinydns config file

echo "tinydnsdir=/etc/tinydns" >/etc/sysconfig/tinydns

Start tinydns service

chmod 755 /etc/sysconfig/tinydns
service tinydns start
chkconfig tinydns on

Test dns server: ask it for some type of records

dnsq soa example.hu 123.123.123.123
dnsq a example.hu 123.123.123.123

axfrdns

Create axfrdns user

useradd --no-create-home -s /bin/false -u 205 -g 200 axfrlog

Install axfrdns

axfrdns-conf axfrdns axfrlog /etc/axfrdns /etc/tinydns 123.123.123.123

Allow a cleint to tranfser zone

cd /etc/axfrdns
cat >>tcp <<EOF
123.123.123.123:allow,AXFR="example.hu"
EOF
make

Create init script

cat >/etc/init.d/axfrdns <<-EOF
#!/bin/bash
#
# axfrdns      DNS zone transfer server
#
# chkconfig: 345 11 89
# Provides: axfrdns
# Required-Start: \$network
# Required-Stop: \$network
# Short-Description: start and stop axfrdns
# Description: Dan Bernstein (DJB) dns zone transfer server
# ZsZs
 
# Source function library.
. /etc/rc.d/init.d/functions
 
prog=axfrdns
progdir=/usr/local/bin
 
# pull in sysconfig settings
[ -f /etc/sysconfig/axfrdns ] && . /etc/sysconfig/axfrdns
 
start(){
    echo -n \$"Starting \$prog: "
    pid=\$(pidof \$progdir/tcpserver \$progdir/\$prog)
    if [[ "\$pid" == "" ]]; then
        # Read up axfrdns environment files and export them
        for env in \$(cd \$axfrdnsdir/env/; ls -1); do envs="\$envs \$env=\$(cat \$axfrdnsdir/env/\$env)"; done
        export \$envs
        \$progdir/envuidgid axfrlog \$progdir/softlimit -d300000 \$progdir/tcpserver -vDRHl0 -x \$axfrdnsdir/tcp.cdb -- "\$IP" 53 \
          \$progdir/\$prog 2>&1 | (\$progdir/setuidgid axfrlog /usr/bin/logger -p local4.info -t \$prog) &
        if [[ "\$?" == "0" ]]
        then
            success
            echo
        else
            failure \$"\$prog start"
            echo
            exit 1
        fi
    else
        failure \$"\$prog start"
        echo
        exit 1
    fi
}
 
stop(){
    pid=\$(pidof \$progdir/tcpserver \$progdir/\$prog)
    if [[ "\$pid" == "" ]]
    then
        echo -n "Stopping  \$prog: "
        failure \$"\$prog not running."
        echo
    else
        echo -n "Stopping \$prog: "
        kill \$pid && success || failure \$"\$prog stop"
        echo
    fi
}
 
# See how we were called.
case "\$1" in
    start)
        start
        ;;
    stop)
        stop
        ;;
    restart)
        stop
        sleep 1
        start
        ;;
    *)
        echo "Usage: \$prog {start|stop|restart}"
        exit 1
esac
 
exit 0
EOF

Create axfrdns config file

echo "axfrdnsdir=/etc/axfrdns" >/etc/sysconfig/axfrdns

Start axfrdns service

chmod 755 /etc/init.d/axfrdns
service axfrdns start
chkconfig axfrdns on

Test axfrdns server

tcpclient 123.123.123.123 53 axfr-get example.hu aa aa.tmp
cat aa
#1352995218 auto axfr-get
Zexample.hu:0.ns.example.hu.:hostmaster.example.hu.:1352995218:16384:2048:1048576:2560:2560
&example.hu::0.ns.example.hu.:259200
+0.ns.example.hu:123.123.123.123:259200
+garfield.example.hu:123.123.123.123:86400
@example.hu::a.mx.example.hu.:0:86400
+a.mx.example.hu:123.123.123.123:86400
+www.example.hu:123.123.123.123:86400

syslog-ng

Relevant lines of syslog-ng.conf to collect logs in sepatare log files:

destination df_djb { file("/var/log/$YEAR/$MONTH/$DAY/djb_$PROGRAM.$YEAR$MONTH$DAY.log" ); };
filter f_djb { facility(local4); };
log { source(s_sys); filter(f_djb); destination(df_djb); };

Thanks to http://www.koelzer.us/~thomas/postfix-CentOS6.html

Comments are welcome!

Saturday, October 20, 2012

Ratelimit callbacks suppressed

Recently I hardened some RHEL6 based machines.
During this hardening process - among the others - I did the following:
- disdabled ipv6 by "options ipv6 disable=1" in /etc/modprobe.d/hardening.conf
- added some more audit rules according to NSA guide
- stopped auditd therefore audit log events are redirected to kernel log
- filtered audit logs by following filter to separate audilt.log:
filter f_audit { match(' audit\(' value("MESSAGE")); };

After this hardening there were staerted appearing "__ratelimit: XX callbacks suppressed" messages regularly in kernel log, like following:

Oct 18 01:00:01 test1 kernel: __ratelimit: 4 callbacks suppressed
Oct 18 01:01:01 test1 kernel: __ratelimit: 192 callbacks suppressed
Oct 18 01:05:07 test1 kernel: __ratelimit: 188 callbacks suppressed

It didn't cause any problem but after a while I've started investigating (thx Cipo) what can cause this strange behaviour.

The root cause of this problem is a bit complex. Let's see them:
- disabling ipv6 module caused that some programs would like to insert it
- I've set an audit rule which logs any module instertion attempts: "-w /sbin/modprobe -p x -k modules"
- there are kernel.printk_ratelimit* kernel parameters
# cat /proc/sys/kernel/printk_ratelimit
5
# cat /proc/sys/kernel/printk_ratelimit_burst
10
This means that there is a 10 msgs/5 seconds limit in kernel logging. Exceeding this limit messages will be dropped AND "__ratelimit NumberOfDroppedMessages: callbacks suppressed" messages will be written to the kernel log.

To put the pieces of the picture together:
- my script runs curl 20 times
- curl tried to insert ipv6 module by modprobe
- modprobe tries were logged by audit (5 lines/ modprobe)
- too much audit log in short time exceeded the ratelimit

My solution:
- re-enable ipv6 by commenting "options ipv6 disable=1" line in /etc/modprobe.d/hardening.conf
- prevent use of ipv6 calls by appending following line to /etc/sysctl.conf:
net.ipv6.conf.all.disable_ipv6 = 1
(Thanks to Daniel Walsh)

These resulted that:
- ipv6 module is already inserted, so programs do not want to insert it
- ipv6 remained pseudo-disabled

After finishing this I've continued getting ratelimit messaged but not regularly.
I've find out that Midnight Commander deletes a few temporary files and changes permissions of its config files after exiting. This process resulted more than 150 lines within one second in audit log...
My solution is that I've appended following line to the /etc/sysctl.conf file:
kernel.printk_ratelimit = 30
kernel.printk_ratelimit_burst = 200
This means that kernel accepts 200 messages/30 sec

Comments are welcome.

Monday, September 17, 2012

CentOS6 KVM with Shorewall

I wanted to install a CentOS6 host and some vitrual machines in it but I have only one public ip address so I cannot use the most common method to make a bridge as public interface.
There are a lot of guides describing how to install KVM with bridged public interface but just a few of them mentioned my situation.

By default there is just a simple firewall configuration tool on CentOS. I am not an iptables guru that is why I started using shorewall as firewall configuration tool long time ago and I am very satisfied with it..

According to libvirt's documentation when a libvirt manageded network bridge starts, some iptables rules applies and it can confuse administrators when there are two iptables configuration tool working on the same time.
It look like it is the time to set up the virtual network manually...

In shorewall there will be four defined zones:
- net: Internet on host's eth0 interface
- fw: the host computer itself
- dmz: virtual machines with configured portfowards from public ip (public services), interface: virbr0
- virt: virtual machines without portforwarding (testing purpose), interface: virbr1

1. First of all after installing libvirt stop and disable autostarting default network:

# virsh net-destroy default
Network default destroyed

# virsh net-autostart default --disable
Network default unmarked as autostarted

# virsh net-list --all
Name                 State      Autostart
-----------------------------------------
default              inactive   no

2. Create bridge manually, aka let the os network configuration scripts make them

# cat >/etc/sysconfig/network-scripts/ifcfg-virbr0 <<EOF
DEVICE=virbr0
TYPE=Bridge
BOOTPROTO=static
ONBOOT=yes
IPADDR=192.168.233.254
NETMASK=255.255.255.0
DELAY=0
STP=off
EOF
# cat >/etc/sysconfig/network-scripts/ifcfg-virbr1 <<EOF
DEVICE=virbr1
TYPE=Bridge
BOOTPROTO=static
ONBOOT=yes
IPADDR=192.168.244.254
NETMASK=255.255.255.0
DELAY=0
STP=off
EOF
# service network restart

3. If you would like to have a DHCP server on these subnets, configure and start dnsmasq as well:

# cat >/etc/dnsmasq.conf <<EOF
domain=example.com
domain=dmz.example.com,192.68.233.90,192.168.233.99
dhcp-range=dmz,192.168.233.90,192.168.233.99, 12h
dhcp-option=dmz,15,dmz.example.com
domain=virt.example.com,192.68.244.90,192.168.244.99
dhcp-range=virt,192.168.244.90,192.168.244.99, 12h
dhcp-option=virt,15,virt.example.com

bind-interfaces
domain-needed
bogus-priv
resolv-file=/etc/dnsmasq.d/resolv.conf
strict-order
listen-address=192.168.233.254
log-facility=/var/log/dnsmasq.log
#log-queries
dns-forward-max=150
cache-size=10000
EOF
# cat >/etc/dnsmasq.d/resolv.conf <<EOF
nameserver 8.8.8.8
nameserver 8.8.4.4
EOF
# chkconfig dnsmasq on
# service dnsmasq start

4. Ensure that you have one-interface config installed in /etc/shorewall.
Update: one interface config is the default, so you can skip this step.

# cd /usr/share/doc/shorewall-4.*/Samples/one-interface
# cp interfaces policy rules shorewall.conf zones /etc/shorewall

5. Append virtual zones definitions to zones file:

# TAB="$(printf '\t')"
# cat >>/etc/shorewall/zones <<EOF
virt${TAB}ipv4
dmz${TAB}ipv4
EOF

6. Append interfaces definitions to interfaces file:

# TAB="$(printf '\t')"
# cat >>/etc/shorewall/interfaces <<EOF
net${TAB}${TAB}eth0${TAB}${TAB}${TAB}dhcp,tcpflags,logmartians,nosmurfs
dmz${TAB}${TAB}virbr0${TAB}${TAB}${TAB}dhcp,tcpflags,nosmurfs,routeback,bridge
dmz${TAB}${TAB}vnet0${TAB}${TAB}${TAB}dhcp,tcpflags,nosmurfs,routeback
virt${TAB}${TAB}virbr1${TAB}${TAB}${TAB}dhcp,tcpflags,nosmurfs,routeback,bridge
virt${TAB}${TAB}vnet1${TAB}${TAB}${TAB}dhcp,tcpflags,nosmurfs,routeback
EOF

7. Rewrite policy definitions according to your needs. For example:

# TAB="$(printf '\t')"
# cat >>/etc/shorewall/policy <<EOF
# Connecto from firewall
\$FW${TAB}ALL${TAB}ACCEPT

# Connect from DMZ machines

dmz${TAB}dmz${TAB}ACCEPT
dmz${TAB}net${TAB}ACCEPT
dmz${TAB}\$FW${TAB}DROP${TAB}${TAB}info

# Connect from VIRT machines
virt${TAB}virt${TAB}ACCEPT
virt${TAB}all${TAB}DROP${TAB}${TAB}info

# Connect from net
net${TAB}all${TAB}DROP${TAB}${TAB}info

# The FOLLOWING POLICY MUST BE LAST
all${TAB}all${TAB}REJECT${TAB}${TAB}info
EOF

8. You should re-configure your sshd on the host to listen on different port and define an alternate SSH macro in shorewall: Warning! After ths step your host's sshd will listen on non default port! Be sure, that you can reach it on this different ports!

# sed -i "s/#Port 22/Port 39022/" /etc/ssh/sshd_config
# service sshd restart
# TAB="$(printf '\t')"
# cat >/etc/shorewall/macro.SSHAlt <<EOF
###############################################################################
#ACTION SOURCE  DEST    PROTO   DEST    SOURCE  RATE    USER
#                               PORT(S) PORT(S) LIMIT   GROUP
PARAM${TAB}-${TAB}-${TAB}tcp${TAB}39022

EOF

9. Define an admin host in params file

# cat >>/etc/shorewall/params <<EOF
ADMIN_HOSTS=11.22.33.44,11.22.66.44
DMZ_GUEST1=192.168.233.1
EOF

10. Enabe masquerading from dmz zone.

echo -e "eth0\t\t\t192.168.233.0/24" >>/etc/shorewall/masq

11. Append or rewrite rules file according to your configuration. For example:

# TAB="$(printf '\t')"
# cat >>/etc/shorewall/rules <<EOF
VNC(ACCEPT)${TAB}${TAB}net:\$ADMIN_HOSTS${TAB}${TAB}\$FW
SSHAlt(ACCEPT)${TAB}${TAB}net:\$ADMIN_HOSTS${TAB}${TAB}\$FW
SSH(DNAT)${TAB}${TAB}net:\$ADMIN_HOSTS${TAB}${TAB}dmz:\$DMZ_GUEST1
EOF

This configuration let the admin connect from ADMIN_HOSTS to the:

host on 39022 port (ssh)
host on 5900-5999 (vnc)
DMZ_GUEST1 virtual machine on port 22 (ssh)

12. Enable shorewall startup:

# sed -i "s/startup=0/startup=1/" /etc/sysconfig/shorewall

13. Start shorewall

# shorewall start

14. Create your virtual machine using

--network bridge:virbr0 if you want to connect it to dmz network
--network bridge:virbr1 to connect it to virt network.

15. Enjoy!

Create local CentOS repository

If you have to install a lot if machines with CentOS or you just play with kickstart script you should create a local repository to speed the process up. All you need as prerequisite is a configured web server and a script which copies the changes only from the public repository.
This script handles the CentOS and EPEL repository as well.

Here comes the script:

# cat > /usr/local/bin/repo-sync.sh
#!/bin/bash

rsync=/usr/bin/rsync
rsyncopts='--progress -avHSP --bwlimit=512 --delete'
rsyncexcl='--exclude=openoffice*.rpm --exclude=fonts-chinese*.rpm 
--exclude=fonts-japanese*.rpm --exclude=fonts-korean*.rpm 
--exclude=libreoffice*.rpm --exclude=firefox*.rpm 
--exclude=thunderbird*.rpm --exclude=ImageMagick*.rpm --exclude=/SRPMS/ 
--exclude=/headers/ --exclude=*.src.rpm --exclude=*.drpm 
--exclude=*-debuginfo-*.rpm --exclude=/debug/ --exclude=/repoview/'

if [ -f /var/lock/subsys/repo-sync ]; then
    echo "Updates via rsync already running."
    exit 0
fi

mirror=ftp.fsn.hu::linux/centos
verlist="6 5"
archlist="i386 x86_64"
baselist="updates os"
local=/var/www/html/mirror/centos/

for ver in $verlist; do
  for arch in $archlist; do
    for base in $baselist; do
      echo "==================================="
      echo "===== CentOS $ver/$base/$arch ====="
      echo "==================================="
      lrepo=$local/$ver/$base/$arch
      /bin/mkdir $lrepo 2> /dev/null
      /bin/touch /var/lock/subsys/rsync_sync
      remote=$mirror/$ver/$base/$arch/
      $rsync $rsyncopts $rsyncexcl $remote $lrepo
      newpkgs=`/usr/bin/find $lrepo -ctime -1 | wc -l`
      if [ $newpkgs -gt 0 ]; then
       /usr/bin/createrepo $lrepo #>> /dev/null
      fi
    done
  done
done

mirror=ftp.linux.cz::pub/linux/fedora/epel
verlist="6 5"
archlist="i386 x86_64"
baselist="."
local=/var/www/html/mirror/epel/

for ver in $verlist; do
  for arch in $archlist; do
    for base in $baselist; do
      echo "==================================="
      echo "===== EPEL $ver/$base/$arch ====="
      echo "==================================="
      lrepo=$local/$ver/$base/$arch
      /bin/mkdir $lrepo 2> /dev/null
      /bin/touch /var/lock/subsys/rsync_sync
      remote=$mirror/$ver/$base/$arch/
      $rsync $rsyncopts $rsyncexcl $remote $lrepo
      newpkgs=`/usr/bin/find $lrepo -ctime -1 | wc -l`
      if [ $newpkgs -gt 0 ]; then
       /usr/bin/createrepo $lrepo #>> /dev/null
      fi
    done
  done
done

Ctrl-D

Some explanation:
- there are some exclusions at the beginning of the script because I do not need any graphical programs for servers
- you should replace mirror hosts and path with one which is closer to you
- be sure that you choose a mirror which supports rsync protocol. http and/or ftp is not necessary for this script. - you can select which version (verlist) and which architecture (archlist) to sync