Setting up the network interfaces is something that seems to give people a hard time (clearly visible here: http://docs.openstack.org/grizzly/basic-install/apt/content/basic-install_network.html). If you follow that guide, one of the most confusing points is how the Open vSwitch fits into the existing architecture.
Assuming you are following the guide, you have 2 networks:
10.10.10.0/24 -> private
10.0.0.0/24 -> public
Your Network Controller, again per the guide, will have an internal-network interface of “10.10.10.9” and an external-network interface of “10.0.0.9”
Your starting network config (/etc/network/interfaces) file will look like this:
Recently, while setting up my the network controller for OpenStack, I saw this message:
# tail -f /var/log/quantum/openvswitch-agent.log
ERROR [quantum.plugins.openvswitch.agent.ovs_quantum_agent] Failed to create OVS patch port. Cannot have tunneling enabled on this agent, since this version of OVS does not support tunnels or patch ports. Agent terminated!
What this means is that the versio of the datapath (shipped by Ubuntu) does not have the support needed to create tunnels or patch ports. This happened on Ubuntu 13.04.
Fortunately, it is VERY easy to solve this. You need to simply build your own datapath for your kernel. For this, you OpenvSwitch’s datapath source, and you need module-assistant:
Let’s say you are at a coffee shop with public internet access, and you don’t want someone snooping on your traffic, so you VPN to your work. However, you also don’t want to tunnel personal stuff out of your work VPN (chat, facebook, youtube, your personal email maybe?), so the question becomes, how do you create 2 different firewalls – one that ONLY allows you to VPN and does not allow any other applications access, and one that then controls the traffic within the VPN channel so that you can utilize the connection for some apps but not others?
At this point, there are only 2 “methods” of running a Firewall on Android: having root and managing/accessing IPTables, or, the only alternative – creating a sub-VPN channel that you pipe the traffic over and filter (which does not require root). Unfortunately, the second type (without root) will not work for this, since we will need to utilize the VPN channel ourselves for our VPN, and to my knowledge, Android let’s you setup only 1 active VPN channel. So, you need 1.) a way to root and 2.) a good Firewall
I read an interesting article last night which highlited some problems with the way SSH process communication happens. I am writing a post about it because it is so simple and yet so effective.
Here is the scenario:
Let’s say that you have a linux system running the latest set of patches/OpenSSH. You have multiple users on the system, and one or more of them have sudo/su/escalated privileges. The idea is that when user ‘A’ connects to the system, user ‘C’ will be able to sniff out their password.
The idea is that almost all ssh daemons by default are configured to use “Privilege Separation”. This means that sshd spawns a process (child) that is unprivileged to listen for incoming network requests. After the user authenticates, another process gets created running as the authenticated user. The magic happens in between these two processes.
A simple example: User ‘C’ ssh-es into the system, escalates their privledges (either by legitimate or non-legitimate means) and starts listening for newly created ssh ‘net’ processes. As soon as user ‘C’ sees a process being crated, they immediately attach strace to it.
UPDATE: Please check out latest version from my git repo: http://git.vpetkov.net/projects – project name: “pandora”
It seems that Pandora is not putting too much time or thought into how they provide and access music online through their website. I really hope they fix this since it’s irresponsible as far as the the DMCA is concerned. Each song is simply an encoded token, and it’s pulled down directly from, presumably, one of their proxy server. If you look at the stream while playing songs on pandora.com, you will notice something like this (ex: not real):
Some assumptions: the “version=4” is high quality or what used to be CD quality (192 kbps). The “lid=#####” is the “login id”, or your unique user number. The “token=…” is the actual song, encoded. By finding the host of these requests, and putting it all together, where the lid is completely optional, you will have a full request URL to a song.
Imagine putting it together like this: (example as a POC, like this)
"http.request.uri contains token and http.host contains pandora"|./worker.pl
Then having something that parses this “buffer”:
print"Token Already Seen...\n";
print">> New Token Added!\n";
# Code removed in order to prevent Abuse!
One way for them to fix this would be to session encode the requests. You should not be able to make requests that originate from outside of pandora.com directly to the servers. Also, the requests should be authenticated. As an addition, they could potentially be checked against what is “played” and controlled for streaming mechanisms. I really hope this fix this as soon as possible.
Droidzone (Joel Mathew) has created a much more advanced fork of this with many improvements – check it out: http://blog.droidzone.in/2013/03/31/automatically-update-all-wordpress-plugins-from-bash/ (While I still very much support this, I believe my updated solution from Sept 30th, 2018 is incredibly easier and has a single dependency on “WWW::Mechanize”. Leaving the link here to Joel’s for anyone that is interested in taking a look at his. His original fork + extension supports good visual output and other options that someone may be interested in. I believe the last update was in 2014.)
I already created a script to upgrade wordpress installations automatically. You can find it here: http://blog.vpetkov.net/2011/06/01/script-to-upgrade-wordpress-to-the-latest-version-fully-automatically Recently, the same general problem came about when it came to plugins. The biggest problem I had is that I had to log-into wordpress, see a number of plugins that were outdated, and then go hunt each one down by generally just copying the name and pasting it into google . Even thought most of the time, the plugin was the first hit, I then had to download the latest version, extract it, and clean it up. Imagine doing this for 10+ plugins for 5+ blogs — constantly. It was just time consuming and frustrating.
Here is my solution in the form of a perl script:
# By: Ventz Petkov
# Date: 06-15-2011
# Last: 02-11-2018
# Version: 3.5
# Comment on last update:
# * WP changed their plugins html format syntax quite a bit...
# * WP changed their plugins URL a tiny bit, and download URL newline/spacing
# * WP changed their description html a bit
# * WP changed their description again - changed to pulling it from the meta tag
1.) You can simply run it, and it will update everything that you have listed in the @plugins array.
2.) You can give it a parameter of a registered plugin name. This does 2 jobs — upgrades an existing plugin, AND installs new ones.
You can definitely add an extension to this. For #1, you can go a step further by making it scan your plugin directory and populating the list from there. If you want to be even fancier, you can relatively easily keep version tracks of what you have installed and what’s currently available, so that you don’t just blindly download new plugins. For me this is sufficient. If anyone is interested in getting help implementing any of these extra additions, feel free to ask and I’ll help as much as I can.
START OF NOTE AND WARNING! Spoofing your Caller ID is legal in the US only if done via VOIP services for legal and legitimate uses, or to block sending your caller ID, but again, only if it is used for legal purposes. An example of a legitimate use is spoofing your own home/cell phone number when making outbound calls via VOIP/SIP. Another example would be spoofing an outgoing number (a bit like NATing) when sitting at a private (let’s say for example 2,3,4, or 5 digit) extension. There are many scenarios where this is absolutely needed — like offices, enterprises, remote employees/road warriors, and phone support.
Spoofing your Caller ID is not legal for false identity, threatening/harassing someone, pranking, lying, or other such negative and immoral actions. If you are interested in some more information, you can find some here: http://www.gordostuff.com/2011/06/fcc-ups-caller-id-spoofing-penalties.html, and here: http://www.gordostuff.com/2011/02/is-faking-caller-id-legal-in-united.html. This said, I am providing this information for anyone who wants to learn about how this is done, or/and is interested in setting it up for their business or personal use, but ONLY for legal and legitimate uses. I am in no way responsible if you do something stupid or illegal. Here is a good background/history and more information on Caller ID Spoofing: http://www.calleridspoofing.info/ END OF NOTE AND WARNING!
The assumption here is that you have some things already setup and working. The article is titled “Spoofing Caller ID on the fly from any phone” and not “how to spoof your Caller ID”. I am assuming that you have: a sip trunk provider with an outgoing plan, a DID, a SIP server with some advanced features (Asterisk and OpenPBX, or something like TrixBox), and most of all — a working setup. The first step is getting DISA (Direct Inward System Access – http://www.voip-info.org/wiki/view/Asterisk+cmd+DISA). The idea is that you will dial your DID phone number, and the sip trunk provider will route it to your IP address. From there, your server will handle the call and connect you inside your system. I absolutely suggest setting up a DISA password/passcode, otherwise, you leave yourself open to abuse and other people will be able to potentially make calls and use your sip account. It is also important to note that generally, you can simply set a from name and number right here in the DISA outbound options. But again, the idea is to make this dynamic. Ones you dial into your system, the next step is to setup an extension that will handle the rest of this. Leave your context “from-internal” if you want to be able to make external calls by default — necessary in order to bridge the active call to your destination. If you are using Asterisk or TrixBox, go to /etc/asterisk/extensions_custom.conf, and enter something like this:
Now here’s what’s happening: When you get your DID, you get the DISA context. From there, after you authenticate yourself with a pin and now you are in your system. At this point, you would hook in your custom context, in this case called “proof-of-concept-custom”. Make sure that the word “custom” is present somewhere. At this point, your recipe will be executed. The first thing you want to do is answer. You can look up each of these commands at the voip-info.org website. For example, Answer: http://www.voip-info.org/wiki/view/Asterisk+cmd+Answer. The next step is to wait 2 seconds. Then you will speak out the current caller ID. This is really just so you know where you are coming from – it is not neccessary. The play (mp3/wav/etc…) play is not really necessary either, but it can be used to queue up different actions. If you will play something, the suggestion is to Answer the channel before hand, and pause/wait for a bit. The next step is to read 10 digits into the “digito” variable. For good measure, and to prevent a mistake, you can speak out the digits again, and then set them as the current Caller ID (the spoofing part). At this point, you can play another sound to queue up the next action. As an extra precaution/security-by-obscurity step, you can prompt for another pin. In this case, it’s “98765”. After the pin has been successfully entered, you can signal via a sound, and then dial and bridge the call to the same number that you set as your Caller ID (impractical, but just for the purpose of a proof of concept). You can very easily modify this to ask for a destination number and call that destination number instead. Please note that this will charge you a twice from the point that you dial the call and bridge it — once for the current/already active call, and once for the new call that you are making to your destination.
Again, there are many legitimate and absolutely necessary cases for this. If you work in any company, most of the time they will not disclose private numbers. If the company is very large, they might simply not have/want to buy individual “routable” phone numbers. Your desk extension of “1234” can be masked behind a general number which routes to “directory/support” when called back. Another great case is someone who works from remote. Say that you work from home and are part of a support group. A customer calls you and reports a problem. Now you want to call the customer back, but you don’t want him to have your personal home number/cellphone – you can spoof your support number and call the customer back.
Something interesting to note is that VOIP/SIP system can choose to not respect Caller ID (cid) blocking/spoofing, and and 1-800/other TOLL-FREE numbers simply do not respect it.
The only point of this article is to demonstrate how easy it is to achieve this dynamically. Again, this is something that you can very easily set statically in the extension or DISA settings. This is not something new or mind blowing. You could have done this over 10 years ago. The point is that you can have a setup which can be activated from any phone and within 30 seconds or less, you can have a dynamically spoofed Caller ID number.
When you host your own WordPress installation, and there is some sort of an update about every month or so, it can quickly get very annoying doing all the upgrade steps manually (for the people who do not have a CPANEL or FTP account). Now imagine hosting 5-6 WordPress installations. Now imagine 100+. Welcome to my nightmare. Eventually I caved in and wrote this:
# This strictly follow the directions mentioned above.
# Utilizes: "rm", "cp", "mv", "wget", "unzip"
# Remove outdated CURRENT_BLOG files per instructions
/bin/rm-Rf wp-includes wp-admin
# Copy TEMP_NEW files per instructions
# Cleanup TEMP_NEW - remove extraction and download.
/bin/rm-Rf wordpress latest.zip
echo"go to: http://$FQDN/wp-admin/upgrade.php"
So, to summarize, this will download the latest version of wordpress, unzip it, and move the new files accordingly.
At the end, it will remind you to “upgrade” your DB, just in case there is an upgrade. I highly suggest backing up your primary blog before you begin this, just because it’s the “safe thing” to do.
That said, in the 10+ years I’ve used this (started long before I posted something here) – I’ve never had anything go wrong!
[updated: Jan 2nd, 2013 | Updated ‘tiny.pl’ to skip “mailto:” references … it polluted emails with replies]
[updated: Nov 28th, 2012 | Updated ‘tiny.pl’ to be much more efficient which resulted in a crazy speedup]
Yesterday I received one too many emails with a long URL that I actually needed to click on. Why is this a problem you wonder? — I use Mutt. Yes, I’ve heard it all, and yes, I don’t think it’s the best email client, but when you spend all day in a terminal, it’s simply a pain launching the browser to send a single email. It’s a “ctrl+a, #, m, type…type, y…sent”, vs “open browser, go to url, log-in, compose, type…type, hit send”. Anyway, given that I am using the Apple Terminal.app which for some reason has not been upgraded in the last 8 years to include hot linking URLs everywhere (correction: It does, but it does not always handle right clicking multi-line links which contain “strange characters and symbols”), I have to suffer. I’ve been toying with the idea of parsing my mutt emails for a while now, and yesterday I finally decided to sit down and write something. My starting point was my .mailcap entry
My first thought was, why not hook a custom perl script to parse the text from the email, extract the urls, and shorten them? After a little bit of work, I realized that I care about the rest of the text too and not just the URLs. The final solution can be found here:
The script starts by NOT reinventing the wheel, and utilizing lynx to parse out the HTML. Please note that this is done only for the ‘text/plain’ type. The way the same script is overloaded is by supplying a second argument for non-html based emails. As you will see, I actually use elinks to parse for html instead of lynx, and the reason for that is because lynx introduces a new character on long URLs for some reason, when used with –dump. This created problems with shortening the URLs. Then the script splits the resulting output into lines, and then it splits each line into “words”. Each “word” is checked for being an URL. If it is, and it’s less than the “trigger” number of characters, it’s shortened and printed, along with the original (nice to keep track). Otherwise, the word is just printed and the process repeats until the end.
While this is EXTREMELY simple concept wise, it is very useful. Is there a down side? — Yes — some potentially private URLs are now public. Solution? — Yes — sign up for bit.ly Pro (free) and use your own domain name. At last, I just want to tack on that while searching for an existing solution to this, I did find a program called “urlview”. I haven’t tried it, but it seems like a much better solution. Here’s some more information on it: http://linuxcommand.org/man_pages/urlview1.html
UPDATE: As it turns out, Terminal.app actually picks up some/most/(all?) long urls. I think it was ‘lynx’ that was wrapping the line at 65-72 characters, which ended up being the cause for the ‘+’ in front of long URLs and the break onto two lines. Anyway, so basically, this means that if you don’t use ‘lynx’ for the HTML parsing, you can potentially click on the links. Either way, I still prefer having tinyurls. Also, I did find a bug in the ‘t’ (non-html emails) version of the script, where in some cases, it will rip out the URL but now show it at all (original or shortened). I noticed this 2 times (out of 1000+ emails), but I just haven’t had time to look into it. I have a feeling that it’s not really my script. The email comes in not containing any html other than an html a href tag. I think that messes with the detection.
If you want to read my full story behind why I even went this route, please continue bellow:
Recently I started looking at getting rid of as much physical infrastructure as possible. My reasons, among it being a pain to maintain, everything surrounding having your own infrastructure is a downfall. Let’s face it — you can’t afford what is really needed to have 99.99%-100% uptime. There are tricks that you can use to join multiple sites, but again, when you really get into it, it costs money and it takes time. Other than having an ESX server as a personal “lab”, I’ve realized that I spend just as much time dealing with physical infrastructure, as I do creating services, hosting stuff, automating things, and programming. This is just wrong! Also, hosting your own infrastructure means dealing with power, bandwidth, static IPs, etc… Anyway, so with that in mind, I started looking at getting rid of my biggest service which had the fewest users — Email.
I hosted a Zimbra server (which I absolutely love) for almost a year, and before that I hosted for 7+ years (and still do at different locations) mail servers running Postfix+Dovecot+SpamAssassin with Some webmail client (Squirrelmail or RoundCube). The problem with hosting your own email server (i’ll use Postfix synonymous with email server) is that everything is a hassle and a half. At the end of the day, if you have one Postfix server, this is fine. If you have 50+ Postfix servers, not so much. And yes, you can ease it by using puppet and common config management like svn+rsync, but it’s still a hassle. The other problem is that common needs like push email, exchange, blackberry BES, calendars, notes, and others simply do not exist as a “one in all” solution that attaches to Postfix. I realized that while being extremely efficient, and while procmail being simply priceless, it is not economical at the end of the day. Users want ease of use, convenience, pretty UIs, and no spam without any effort on their behalf.
This led me into looking at Google Apps (I’ll use Gmail synonymous). It seemed like the perfect solution — off site, fully managed, relatively cheap (or free), common UI which almost everyone is familiar with, and virtually no spam. It provided smtp(s), imap(s), pop(s), and other common services. The few problems that should be brought up front are: privacy, security, space, and limitations. With “GMail”, (free google app), you are limited to 7-7.5GB per user, 25 users, and “some” advanced SMTP features. You can always pay $50/year/account in order to 25GB with unlimited users and some more programmable/API features. The thing that really attracted me was the ability to get an “all-in-one” solution that was extremely easy to deploy for multiple users. The reality is that most users just want their own email at their own domain, with some storage, some web UI, and no spam or viruses. This was something that I was doing with my “Postfix setup”, and I had scripted quite well infact, but with Google Apps, it was a matter of 15 minutes per account.
Now, the main two problems were: how do my users who use mutt (myself being one of them) get to their email, and how to existing services AND “dumb services” (storage devices, vCenter, etc…) communicate to the “Gmail” servers. The first — mutt — turned out to be much easier than I thought. If you are already using mutt with any authenticated IMAP/SMTP server, you have probably already stumbled onto: msmtp. With a little more work, and you can get this piece of software to work perfectly with Gmail. If you need some help, check out: http://blog.vpetkov.net/documentation/network-services/smtps-and-imaps/mutt-with-google-gmailgoogle-apps-or-any-imap-server/ The second problem turned out to be relatively easy, after doing some research and a bit of trial and error. The main idea is that you create a simple “relay” server in a way. A lightweight Postfix installation which only auths and forwards/relays all the emails to Gmail/Google Apps/any IMAP server for that matter. I went the extra step and configured it to be able to use different SMTP servers with different auth based on different user/email accounts. You can get all the technically details at the top of this post. Good luck, and I hope this saves you some time.