Server for iPhone; continuous connection - iphone

Ok lets say I want to create a connection between my iPhone app and my server (i'd like to try and use GoDaddy servers for this) to server real time location data to users.
I've seen plenty of good stuff online about using sockets, streams, ASIHttpmessage, CFHTTPMessageRef, etc., but what I'm unclear about is how to set up a server that continuously servers real time data to users (I believe you'd need a stream of data going to the user for this, not just a single http request and response). How does one take a host like GoDaddy and run server code on it. I know you can set up a server like this using terminal, but I don't have access to command line or the ability to run this "server program" from my web host as far as I know. Is there software I can download on my cpanel for this? Do I need a virtual private server and different hosting via GoDaddy maybe?
Does anyone know how I can do this or if my understanding of this whole thing is wrong. Please keep in mind I need this real time (or close to). Please, educate me. I really just need a better understanding of how this works.

Related

Loopback.io backup server and server to server replication

I am thinking of adopting Loopback.io to create a REST API. I may need the following approach: an inTERnet server (run by me) to which clients connect, plus a fallback inTRAnet server to which clients connect only in case the internet connection is down. This secondary fallback server should then replicate data on the main server when the internet connection is up and running again. As clients are on the same inTRAnet they should be able to switch automatically to the fallback server. Is this possible as an idea and if so, what do you recommend i start digging into?
Thank you all!
Matteo
Simon from my other account. I believe what you want is possible as you can use whatever client side technology you want with LoopBack. As for easy solutions, I'm not familiar enough with Cordova to give any insight there.
It is definitely possible, but I suggest going through the getting started tutorial first. You'd probably create two application servers and have another proxy in front to route the requests to server a or b based a heartbeat from the main server. You would have to code all the logic and set up the infrastructure yourself though.

Possible to use server for collecting and distributing mail

We currently have POP3 mail accounts where I am and try as I might to convince my manager that we should be using hosted IMAP or Exchange he won't budge because of the cost. The staff are mostly out of office so there is no domain server here, however, we do have a dedicated server and I wondered whether I could use this to collect the mail and distribute it from there in some way.
Effectively what I'm trying to do is ensure mail is stored somewhere other than the end users machine because backups are user dependant at the moment. With hosted Exchange or Exchange on this server would be simple but my manager won't shell out for it. I have seen free mail servers called MailEnable and Axigen but unsure if they will do the job. Sorry if this seems like an easy or stupid question but never needed to do this before.
I am assuming due to the reference to Exchange that you are on Windows.
If you have an old box lying around that works, you could install linux on it and then choose from a number of different imap servers. Dovecot and Courier are both good choices and I have worked with them before.
You could use fetchmail to then pick up the mailboxes and then deliver to the imap boxes or get them deliver directly.
Setting up such a linux server for email was one of the first things I ever did on Linux. While initially daunting, once you get the hang of it, it is pretty straightforward and there are plenty of resources out there to help.
Ubuntu is probably the easiest to get used to. CentOs is also a reasonable choice.
You shouldn't be running your own server if you aren't willing to administer your own server, and they are not easy to configure if you don't know what you are doing (e.g., you mess up and you are exploited for spamming).
Look into a service like mailgun. In my application we are using them for forwarding to REST endpoints as well as onto another SMTP server.
Competitors that wound up not meeting my needs but may meet yours include Dyn, email yak, Sendgrid, etc. etc.
Why not just setup the mail clients to store their mail files on a standard network drive or share? I follow that this situation is pretty silly in your view - 100% because of the ridiculous constraints that you are being asked to work within: I would similarly find the solution I am suggesting ridiculous generally; but under the circumstances, it seems like a simple answer to your problem - replacing distributed mail storage and backup with centralized storage and backup.
Don't POP3 email clients have the option keep a copy on the server? Mine certainly does. See second tick box on the pic.
You can then periodically take a back up of all the emails from the server to stop it getting clogged up.

Where would I learn more about interpreting network packets?

I'm working on a personal project. It's to recreate server software for the game "Chu Chu Rocket" for the Sega Dreamcast. Its' servers went down in 2004 I believe. My approach is to use dnsmasq to change the originl hostname that the game originally connected to, to my own system. With a DC-PC server set up, I have done just that, now instead of it looking up a non-existent dns record, it connects to my computer which will eventually run the server software. I've used tshark (cli wireshark) to capture what's going on between the client (dreamcast) and the server (my computer). The problem is, I'm getting data, but I'm not sure how to interpret it, I don't know what it's saying, but I'm sure it can be done because private PSO servers were created, those are far more complex.
Very simply, where would I go about learning how to interpret data packets, and possibly creating packets that will respond to such queries from the client?
Thanks,
Dragos240
If you can get the source code for the server software on your PC, then that is the best place to look.
Otherwise, all you can do is look at the protocol, compare runs, and make notes of similarities and differences. With any luck, the protocol won't be encrypted.

Send emails through VB6 if no email client

I have a VB6 app which is used by a large number of clients.
I need to allow the clients to be able to send emails to me. In the past I have done this using Microsoft MAPI controls. However, not all of them have an email client installed, since they use webmail instead.
Is there any other method anyone can recommend which would allow them to do this?
SMTP
You can use CDO for Windows to do this if we make a few assumptions:
Your users are all on Win2K or later.
The users will never be behind a firewall blocking SMTP or proxying all SMTP port use to a corporate server.
You have an SMTP server that you have an account you can let the user-mails be sent with.
You embed the server's address and account credentials in your program.
Sometimes using an SMTP server listening on an alternate port will address the second issue, but often such an alternate port is even more likely to be blocked.
SMTP is Dying
Abuse over time has made SMTP less and less viable for automated/assisted user contact. There are just too many variables involved in trying to open some sort of "clear channel" for SMTP communication as people work harder to fight spammers and such.
Today I would be much more likely to use either WebDAV or a Web Service for this. Both use HTTP/HTTPS which is more likely to get past firewalls and usually get by most proxy servers as well. WebDAV is often more "slippery" at this than Web Services, which more and more proxies are bocking. You can also use something more RESTful than SOAPy since the traffic "smells more like" user browsing to proxy servers.
WebDAV is a Clean Option
There are even free WebDAV providers offering 2GB of storage with a main and a guest user. The guest account can be given limited rights to various folders so some folders they might post your messages to, other folders they might get data from (read only folders), etc. For a paid account you can get more storage, additional users, etc.
This works well. You can even use the same hosting for program version files, new version code to be downloaded and installed, etc. All you need on your end is an aggregator program that scoops up user posted messages and deletes them using the main user/pw.
You still need to embed user credentials in your program, but it can be a simpler matter to change passwords over time. Just have the program fetch an info file with a new password and an effective date and have the program flip the "new" password to "current" once run on that date or after.
WebDAV support in Windows varies. From WinXP SP3 forward you can simply programmatically map a drive letter to a WebDAV share and then use regular file I/O statements against it, and unmap the letter when done. For more general use across even Win9x you can build a simple WebDAV client on top of XMLHTTPRequest or use a 3rd party library.
Web Services Have Higher Costs
Just to start with you have server-side code to write and maintain, and you have to use a specific kind of hosting. For example if you built it using PHP you need a PHP host, ASP an ASP host, ASP.Net an ASP.Net host, etc.
Web Services can also be more problematic in terms of versioning. If you later update your program to provide different information in these user contact posts you have to make another Web Service as well as changing both the application and the aggregator. Using WebDAV you can just make a "new format" folder on the server and have the new program post the data there in the new format. Your aggregator can simply pull from both folders and do any necessary reformatting into your new local database/message repository format.
This is merely an incremental additional effort though and a Web Service might be the way to go, even if it is just something written like an HTML Form GET/POST acceptor.
Although this question is for VBA you may find it of interest. Sending Emails using VBA without MAPI

See what website the user is visiting in a browser independent way

I am trying to build an application that can inform a user about website specific information whenever they are visiting a website that is present in my database. This must be done in a browser independent way so the user will always see the information when visiting a website (no matter what browser or other tool he or she is using to visit the website).
My first (partially successful) approach was by looking at the data packets using the System.Net.Sockets.Socket class etc. Unfortunately I discoverd that this approach only works when the user has administrator rights. And of course, that is not what I want. My goal is that the user can install one relatively simple program that can be used right away.
After this I went looking for alternatives and found a lot about WinPcap and some of it's .NET wrappers (did I tell you I am programming c# .NET already?). But with WinPcap I found out that this must be installed on the user's pc and there is nog way to just reference some dll files and code away. I already looked at including WinPcap as a prerequisite in my installer but that is also to cumbersome.
Well, long story short. I want to know in my application what website my user is visiting at the moment it is happening. I think it must be done by looking at the data packets of the network but can't find a good solution for this. My application is build in C# .NET (4.0).
You could use Fiddler to monitor Internet traffic.
It is
a Web Debugging Proxy which logs all HTTP(S) traffic between your computer and the Internet. Fiddler allows you to inspect traffic, set breakpoints, and "fiddle" with incoming or outgoing data. Fiddler includes a powerful event-based scripting subsystem, and can be extended using any .NET language.
It's scriptable and can be readily used from .NET.
One simple idea: Instead of monitoring the traffic directly, what about installing a browser extension that sends you the current url of the page. Then you can check if that url is in your database and optionally show the user a message using the browser extension.
This is how extensions like Invisible Hand work... It scans the current page and sends relevant data back to the server for processing. If it finds anything, it uses the browser extension framework to communicate those results back to the user. (Using an alert, or a bar across the top of the window, etc.)
for a good start, wireshark will do what you want.
you can specify a filter to isolate and view http streams.
best part is wireshark is open source, and built opon another program api, winpcap which is open source.
I'm guessing this is what you want.
capture network data off the wire
view the tcp traffic of a computer, isolate and save(in part or in hole) http data.
store information about the http connections
number 1 there is easy, you can google for a winpcap tutorial, or just use some of their sample programs to capture the data.
I recomend you study up on the pcap file format, everything with winpcap uses this basic format and its structers.
now you have to learn how to take a tcp stream and turn it into a solid data stream without curoption, or disorginized parts. (sorry for the spelling)
again, a very good example can be found in the wireshark source code.
then with your data stream, you can simple read the http format, and html data, or what ever your dealing with.
Hope that helps
If the user is cooperating, you could have them set their browser(s) to use a proxy service you provide. This would intercept all web traffic, do whatever you want with it (look up in your database, notify the user, etc), and then pass it on to the original location. Run the proxy on the local system, or on a remote system if that fits your case better.
If the user is not cooperating, or you don't want to make them change their browser settings, you could use one of the packet sniffing solutions, such as fiddler.
A simple stright forward way is to change the comupter DNS to point to your application.
this will cause all DNS traffic to pass though your app which can be sniffed and then redirected to the real DNS server.
it will also save you the hussel of filtering out emule/torrent traffic as it normally work with pure IP address (which also might be a problem as it can be circumvented by using IP address to browse).
-How to change windows DNS Servers
-DNS resolver
Another simple way is to configure (programmaticly) the browsers proxy to pass through your server this will make your life easier but will be more obvious to users.
How to create a simple proxy in C#?