learn more stuff

compiling seagull on ubuntu 10.10

2011-12-22T16:45:00.001-06:00

Seagull is a free, Open Source (GPL) multi-protocol traffic generator test tool. I will be using Seagull to generate some Diameter traffic for testing. After trying for hours to get this software to compile under Ubuntu, I finally gave up and used the windows cygwin binarys, which worked like a charm.

Seagull is a handy tool for generating very specific traffic types, and provides many scenarios already configured. To get going on Windows, all that I had to do was edit the IP addresses in some XML config files and I was up and running. Nice.

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I'll document some of the pains that I went through here during compilation under Ubuntu 10.10 for Seagull in case someone else happens to try this out. There has been some time since Seagull was updated, and compilers have changed a bit since then. Fortunately I ran into this blog post that helped me to understand some of the problems that I was running into.

At first, KSH and GCC are missing from Ubuntu, so you have to install them.

# apt-get install ksh build-essential bison flex libntl-dev libsctp-dev

Source files that generate the error "error: memset was not declared in this scope" need to have this include line added.
#include <cstring>

Source files that generate the error "X" need to have this include line added.

#include <cstdlib>

Source files that generate the error "Y" need to have = changed to == in some if statements.

Source files that generate the error "fatal error: asm/page.h: No such file or directory" need to have a specific include line to point at the actual page.h file. From http://forums.fedoraforum.org/showthread.php?t=190186.
#include "/usr/src/linux-headers-2.6.35-22/arch/x86/include/asm/page.h"

Source files that generate the error "/usr/bin/ld: cannot find -lTTL" can be fixed by commenting a line and uncommenting a line in TCAP section of build.conf.

And lastly, I have not yet solved this one. Error message is "library-trans-extsctp/socketSCTP_t.hpp:23: fatal error: ext_socket.h: No such file or directory". I cant seem to find a library that provides sctp_initLibrary() as ext_socket.h used to, also cant find ext_socket.h on my system or in an available package.

So, use the windows version, because it works.

the diameter protocol

2011-12-20T15:20:00.003-06:00

Diameter is an authentication, authorization and accounting protocol for computer networks, and an alternative to RADIUS.

Anyway, here are some links.

For troubleshooting diameter, I have mostly been using tcpdump and wireshark since wireshark has dissectors for the Diameter protocol. Next I will be working on tcpdump filters.

Robot mower roundup

2011-12-11T19:21:00.001-06:00

I am not the only person on YouTube with a remote controlled lawn mower. It seems like more and more show up every day, so I decided to document a few of my favorites.

Lawnbot 400

This is the project that inspired me to create my own remote controlled mower. His website is here. What I liked about this mower is that it appears to have adjustable cutting deck height, and the dirt carrier on top.

One thing that I don't like about this design is how bulky the frame is compared to the size of the cutting deck. I took this design into consideration when building my mower, and it still comes to mind when I'm thinking about how to solve my rigid cutting height problems. The fit and finish on this project is top notch, and that is probably why it is listed in Make Magazine. Good work, Sir.

Lawnrover m3736

Right away I saw "Can I get this in Blue?" from the YouTube comments. This tells me that someone out there wouldn't change a thing and would enjoy this mower as is.

Based on the number of features on this mower, I suspect that this is not the first revision of this project. I'm just guessing here but the balance looks to be as such that if you sat on it, you might be able to pull wheelies! Imagine! I like the toolbox on this one as it is a great way to keep electronics safe from grass and dust and it is easy to open and get at the components if you need to.

thekruck2009 radio control lawn mower

This one deserves a name. I really like the compact size of everything on here. The little caster wheels might prove problematic when transitioning between different surfaces, but they look to be working just fine here.

There are not a lot of details posted about this project, and the viewer comments on YouTube appear to go unanswered.

I posted a question about the electrical system, but I may not get an answer. I was interested in whether the system is 12 or 24 volts. It seems like it must be a single battery at 12 volts, as I'm not sure where you would fit another battery on there. It also appears to be in the same situation as my project regarding height adjustability. I have to say it again, though, I just love how compact this one is.

DIY Robot Lawn Mower

This one is 100% custom and it represents an entire genre of custom mowers that are otherwise missing from this post. The guy combined a barbie jeep, razor blades, batteries, and an electric dog fence to create a completely autonomous mowing platform.

This device is not remote controlled, it works entirely on its own by bumping into things and turning itself a little bit each time. I think it would take ages to mow the yard based on how it moves and the fact that it is going to mow over the same tracks multiple times. I think this is a great device, though, as it is so totally different from the other projects in this category. I can really appreciate the effort that was put forth to make this, especially the custom logic board parts. Good work, Sir.

November already?

2011-11-08T18:44:00.004-06:00

So, its November already and I haven't posted much. Well, I changed jobs. Now I work for F5 Networks, Inc. My new employer is awesome.

Anyway, back to the books. Here is what I have been reading lately.

MD5 Authentication Between BGP Peers Configuration Example
http://www.cisco.com/en/US/tech/tk365/technologies_configuration_example09186a0080b52107.shtml
Protection of BGP Sessions via the TCP MD5 Signature Option
http://www.ietf.org/rfc/rfc2385.txt

During my BGP and TCP MD5 digest searching, I found an awesome website called PacketLife. This website provides packet captures for just about everything. I can tell that this is going to be a good "known working example" resource. Check them out at the link below.

http://packetlife.net/captures/protocol/bgp/

Later.

august reading materials

2011-08-18T13:34:00.002-05:00

TCP Misc
http://www.texample.net/tikz/examples/tcp-state-machine/
http://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_segment_structure
http://www.ietf.org/rfc/rfc793.txt

ICMP Messages
http://en.wikipedia.org/wiki/Internet_Control_Message_Protocol#List_of_permitted_control_messages_.28incomplete_list.29

OpenSSL CSR/CRL
http://gagravarr.org/writing/openssl-certs/ca.shtml

SSL Handshake
http://publib.boulder.ibm.com/infocenter/tivihelp/v2r1/index.jsp?topic=%2Fcom.ibm.itame2.doc_5.1%2Fss7aumst18.htm

SSL Certificate verification
http://www.madboa.com/geek/openssl/

HTTP
http://www.ietf.org/rfc/rfc2616.txt

Other Misc
http://wiki.wireshark.org/Gratuitous_ARP

Python Exercises - Count the Words

2011-07-12T21:35:00.001-05:00

My Python solution to the problem "count the frequency of words from a given input stream" is here at ideone.com.

I started out by using a For loop to send each word from a single line to the dictionary mapping function. Once this was working and proved that the dictionary mapping function worked, I re-factored the code to use the map() function instead of the For loop. Perhaps I could save some time in the mapping function (named wordcounter) by using the .setdefault method of the Dictionary object instead of explicitly checking for a key's existence in the Dictionary every time the function is called.

Reading materials:
http://docs.python.org/library/stdtypes.html#dict

http://docs.python.org/library/functions.html#map

Reducing fragility in test automation

2011-07-12T12:25:00.001-05:00

I would like to learn more about this subject. Here are some reading materials for now.

http://marlenacompton.com/?p=424
http://www.satisfice.com/articles/test_automation_snake_oil.pdf
http://www.kaner.com/pdfs/autosqa.pdf

Check out my robot mower!

2011-06-17T15:32:00.002-05:00

My robot lawn mower project is alive! See http://www.d33z.com/p/robot-mower.html for build details, videos, etc. Yay!

Python Exercises - Reverse a String

2011-05-06T22:51:00.000-05:00

As an exercise to gain more experience with Python, I wrote a function to reverse a string. Playing with ideone.com's online Python IDE was also a bonus. You can run the following code here. This is probably not the best way to solve this problem, but it works.


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# implement a function that reverses a string
def reverse_string(in_string):
        # reverse string using brute force
        print " input is %s" % in_string
        length = len(in_string)
        out_string = ""
        for position in range(length, 0, -1):
                out_string += in_string[position-1]
        print "output is %s" % out_string
        return out_string
 
a = reverse_string("1234")
print a

While I am aware that Python already provides a reversed() function as well as a .reverse() method for List objects, I wanted to gain the experience of having written a function to perform the task myself, so I wrote one. In retrospect, reading this sooner might have helped me write this code in far fewer lines.

Robot Framework

2011-05-05T13:57:00.000-05:00

A great blog post by Frank Berthold helped me learn to use Robot Framework. Some questions remained for me after reading Robot Framework's Quick Start Guide, and Frank's blog post answered them. My application was a content management system, and for historical purposes is available online here.

Here is one of the test suites that I came up with for testing the application:

*** Testcases ***
Homepage allows Admin Login
   Sign in as Admin

Homepage allows Admin to Add an Entry
   Click Link Add
   Page Should Contain Add a blog entry

Add an Entry page allows adding a test Entry
   Input Text title Testing Entry Title
   Input Text subtitle Subtitle for Testing Entry
   Input Text content This is a test Entry.
   Click Button Save
   Page Should Not Contain Error

Homepage shows test Entry
   Page Should Contain   Testing Entry Title

fwmark + iproute2

2011-04-21T09:53:00.001-05:00

http://tldp.org/HOWTO/Adv-Routing-HOWTO/lartc.netfilter.html

You can set up policy routes using fwmarks in Linux using iproute2. Awesome!

Matt's Fault Isolation Model

2011-04-13T20:23:00.000-05:00

An ex-colleague of mine introduced me to a new way to look at problems, and I thought I would share it. The person that explained this to me was Matt Brace.

All problems are either in software, hardware, or configuration. I'll elaborate later.

Multiple routing tables for Linux

2011-04-07T20:20:00.000-05:00

Here are some reading materials related to policy routing and multiple routing tables in Linux. You may find this useful for tunneling, IPv4 NAT, routing, and wan load balancing.

http://lartc.org/howto/lartc.rpdb.html
http://linux-ip.net/html/routing-rpdb.html
http://www.policyrouting.org/iproute2.doc.html
http://mailman.ds9a.nl/pipermail/lartc/2003q3/010086.html

Musical Chairs with Websites

2011-04-03T16:40:00.000-05:00

I've been trying to decide where to host my blog.

In the beginning, there was blogger. I used blogger and flickr together for sharing pictures from my mobile phone. The picture quality was terrible, due to the device, and I never had any time to fill in descriptions for the pictures. The blogger side of things just became a list of pictures that were also available on flickr, which didn't make a lot of sense.

Once I needed more than just a blog, I hosted my own LAMP web server and used Wordpress. That worked for some time but ended up slowing to a halt until I just stopped updating anything. I later transitioned the site to a friends shared hosting server where it could live with other websites and not cost me a thing.

Now, I have come back full-circle to blogger. I am no longer hosting or managing a web server. I just need to decide between picasa and flickr.

Thoughts? Leave a comment...

http byte range request

2011-03-23T03:24:00.000-05:00

http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.35.2

http://en.wikipedia.org/wiki/List_of_HTTP_header_fields

http://www.web-polygraph.org/docs/userman/ranges.html

http://labs.apache.org/webarch/http/draft-fielding-http/p5-range.html

http://www.askapache.com/htaccess/apache-status-code-headers-errordocument.html

saving money on the electric bill

2010-04-09T05:51:00.000-05:00

After receiving a fairly large (>$200) electric bill for a month in which we did not use heat or a/c, I was convinced that I needed to audit my power usage habits. Here are a few things that I've done to try and reduce my electric bill:

Moved d33z.com to shared hosting. Now I don't have to run a server 24x7 at home.

Replaced ancient Cisco switch for Green D-Link. The Cisco cost $20/mo to run, the D-Link costs about $1.50/mo.

Add power strips to entertainment systems, and turn them off when not in use.

Reduce fish tank light timer to only light after sunset.

Bleh. I'm hoping just the above will cut out about $50 on my monthly bill.

opie keys: One-time Passwords In Everything

2010-03-04T06:25:00.000-06:00

OPIE is the initialism of "One time Passwords In Everything". Opie is a mature, Unix-like login and password package installed on the server and the client which makes untrusted networks safer against password-sniffing packet-analysis software like dSniff and safe against Shoulder surfing. It works by circumventing the delayed attack method because the same password is never used twice after installing Opie. OPIE implements a one-time password (OTP) scheme based on S/key, which will require a secret passphrase (not echoed) to generate a password for the current session, or a list of passwords you can print and carry on your person.

OPIE uses an MD4 or MD5 hash function to generate passwords.

OPIE can restrict its logins based on IP address. It uses its own passwd and login modules.

Sources:

http://en.wikipedia.org/wiki/OPIE_Authentication_System

http://www.freebsd.org/doc/handbook/one-time-passwords.html

ipsec: Authentication Header (AH) and Encapsulating Security Payload (ESP)

2010-02-02T12:49:00.000-06:00

The IPsec suite is a framework of open standards. IPsec uses the following protocols to perform various functions:

Internet key exchange (IKE and IKEv2) to set up a security association (SA) by handling negotiation of protocols and algorithms and to generate the encryption and authentication keys to be used by IPsec.

Authentication Header (AH) to provide connectionless integrity and data origin authentication for IP datagrams and to provide protection against replay attacks.

Encapsulating Security Payload (ESP) to provide confidentiality, data origin authentication, connectionless integrity, an anti-replay service (a form of partial sequence integrity), and limited traffic flow confidentiality.

The IPSec headers (AH and ESP) can be used in transport mode or tunnel mode. In transport mode, the original IP header is followed by the AH or ESP header. If ESP is used in transport mode, only the upper-layer (e.g., TCP, UDP, IGMP) is encrypted. The IP header is not encrypted.

Additional Reading:

http://www.networksorcery.com/enp/protocol/esp.htm

http://www.networksorcery.com/enp/protocol/ah.htm

http://docs.hp.com/en/J4255-90011/ch04s03.html

http://en.wikipedia.org/wiki/IPsec

Virtual Private Dialup Network (VPDN)

2010-01-22T09:43:00.000-06:00

A VPDN is a network that extends remote access to a private network using a shared infrastructure. VPDNs use Layer 2 tunnel technologies (L2F, L2TP, and PPTP) to extend the Layer 2 and higher parts of the network connection from a remote user across an ISP network to a private network. VPDNs are a cost effective method of establishing a long distance, point-to-point connection between remote dial users and a private network.

Reading:

http://www.cisco.com/en/US/tech/tk801/tk703/tsd_technology_support_protocol_home.html

Cisco VPDN Configuration Examples and TechNotes

l2tp: layer 2 tunneling protocol

2009-12-29T07:15:00.000-06:00

In computer networking, Layer 2 Tunneling Protocol (L2TP) is a tunneling protocol used to support virtual private networks (VPNs). It does not provide any encryption or confidentiality by itself; it relies on an encryption protocol that it passes within the tunnel to provide privacy.[1]

Although L2TP acts like a Data Link Layer protocol in the OSI model, L2TP is in fact a Session Layer protocol,[2] and uses the registered UDP port 1701. (see List of TCP and UDP port numbers).

(shamelessly copied from wikipedia)

Additional Reading:

http://en.wikipedia.org/wiki/Layer_2_Tunneling_Protocol

http://www.cisco.com/en/US/docs/ios/12_0t/12_0t1/feature/guide/l2tpT.html

http://www.cisco.com/en/US/tech/tk801/tk703/technologies_tech_note09186a0080094c4f.shtml

http://www.iana.org/assignments/l2tp-parameters

protocol overhead

2009-12-18T09:47:00.000-06:00

Additional Reading:

http://sd.wareonearth.com/~phil/net/overhead/

http://en.wikipedia.org/wiki/Protocol_overhead

Iptables : Remove an entry

2009-11-17T07:30:00.000-06:00

Sorry it's been a while.

You can either delete by number or by recreating the rule. "iptables -D
INPUT 3" will remove the 3rd (counting from 1) rule. Or "iptables -D
INPUT -s 65.75.152.40 -j DROP" will remove the corresponding entry
independent of location. The rules must match exactly though or you'll
get a "Bad rule" error.

http://www.plug.org/pipermail/plug/2004-November/010606.html
http://www.redhat.com/docs/manuals/linux/RHL-9-Manual/ref-guide/s1-iptables-options.html
http://netfilter.org/documentation/HOWTO/packet-filtering-HOWTO-7.html

xargs and find

2009-11-16T08:16:00.000-06:00

xargs is a command on Unix and most Unix-like operating systems. It is useful when one wants to pass a large number of arguments to a command. Until Linux kernel 2.6.23, arbitrarily long lists of parameters could not be passed to a command ^[1], so xargs will break the list of arguments into sublists small enough to be acceptable.

Additional Reading:

http://en.wikipedia.org/wiki/Xargs

http://www.softpanorama.org/Tools/xargs.shtml

http://www.linuxplanet.com/linuxplanet/tutorials/6522/1/

tail -f multiple files

2009-11-03T07:58:00.000-06:00

Pass more than one filename to tail -f and it will follow each file and let you know when one changes.

daniel@mycomputer:~$ tail -f /var/log/dmesg /var/log/kern.log
==> /var/log/dmesg <==
[   14.951256] type=1505 audit(1256945274.318:9): operation="profile_load" name="/usr/sbin/tcpdump" name2="default" pid=2001
[   16.052417] e1000e 0000:00:19.0: irq 2300 for MSI/MSI-X
[   16.108300] e1000e 0000:00:19.0: irq 2300 for MSI/MSI-X
[   16.108533] ADDRCONF(NETDEV_UP): eth0: link is not ready
[   17.572692] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[   17.572694] Bluetooth: BNEP filters: protocol multicast
[   17.578508] Bridge firewalling registered
[   18.272754] 0000:00:19.0: eth0: Link is Up 100 Mbps Full Duplex, Flow Control: None
[   18.272757] 0000:00:19.0: eth0: 10/100 speed: disabling TSO
[   18.272906] ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready

==> /var/log/kern.log <==
Nov 2 09:39:21 mycomputer kernel: [231116.479553] [drm] Resetting GPU
Nov 2 09:39:21 mycomputer kernel: [231116.479608] [drm] writeback test succeeded in 1 usecs
Nov 2 09:39:25 mycomputer kernel: [231120.406627] CPU0 attaching NULL sched-domain.
Nov 2 09:39:25 mycomputer kernel: [231120.406630] CPU1 attaching NULL sched-domain.
Nov 2 09:39:25 mycomputer kernel: [231120.407377] CPU0 attaching sched-domain:

Bash Numeric Comparison

2009-11-02T08:40:00.000-06:00

Do not use > or < when comparing numbers in BASH. It doesn't work. It tries to redirect output instead of performing the comparison. Use -lt or -gt instead.

Additional Reading:

http://fvue.nl/wiki/Bash:_Numeric_comparison

http://tldp.org/LDP/abs/html/