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12.07.2015

Scapy and IP Options

Create packets with custom IPv4 IP Option fields using Scapy:

>>> packet=IP(src="203.0.113.1",dst="203.0.113.2",options=[IPOption('%s%s'%('\x86\x28','a'*38))])
>>> ls(packet)
version    : BitField             = 4               (4)
ihl        : BitField             = None            (None)
tos        : XByteField           = 0               (0)
len        : ShortField           = None            (None)
id         : ShortField           = 1               (1)
flags      : FlagsField           = 0               (0)
frag       : BitField             = 0               (0)
ttl        : ByteField            = 64              (64)
proto      : ByteEnumField        = 0               (0)
chksum     : XShortField          = None            (None)
src        : Emph                 = '203.0.113.1'   (None)
dst        : Emph                 = '203.0.113.2'   ('127.0.0.1')
options    : PacketListField      = [<IPOption  copy_flag=1L optclass=control option=commercial_security length=40 value='aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa' |>] ([])
>>> sr1(packet)

The above code results in the following packet (as seen by Wireshark):

Wireshark showing the packet with the custom IP Option

23:56 | Networking | Permalink

11.07.2015

Upgrade to Debian 8 without systemd

To avoid the automatic installation/switch to systemd during the upgrade to Debian 8, it is enough to prevent the installation of the systemd-sysv package.

This can be done by creating a file /etc/preferences.d/no-systemd-sysv with the following content:

Package: systemd-sysv
Pin: release o=Debian
Pin-Priority: -1

(via)

11:27 | Linux | Permalink

05.07.2015

Obey the cloud!

So true...

Johannes Kretzschmar - Obey the cloud!

"Obey the cloud!" by Johannes Kretzschmar, licensed under CC BY-NC-SA 3.0.

17:22 | Misc | Permalink

25.02.2015

The Day Is My Enemy

Looking forward to see the live performance at the Future Music Festival 2015 :-)

03:08 | Music | Permalink

11.01.2015

Hand-crafted IP packets

Form RFC 791

(via)

23:16 | Networking | Permalink

25.12.2014

Christmas Run

Run #9 around Centennial Park. Two rounds again, this time during noon with some nice sun and a whopping 30°C :-)

Centennial Midday Run 2x

12:16 | Misc | Permalink

22.12.2014

Advent Run #8

Run #8 around Centennial Park. Two rounds again, and with some rain :-(

Centennial Morning Run 2x

23:35 | Misc | Permalink

19.12.2014

Advent Run #7

Run #7 around Centennial Park. Only one round, but the fastest one so far.

Centennial Morning Run

23:21 | Misc | Permalink

16.12.2014

Advent Run #6

Run #6 around Centennial Park. Two rounds this time, with a slower pace though.

Centennial Morning Run 2x

23:31 | Misc | Permalink

12.12.2014

Advent Run #5

Run #5 around Centennial Park. Didn't have the patience to wait for the GPS to lock onto the signal, thus the late start.

Centennial Morning Run

22:51 | Misc | Permalink