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No real network connection (becouse it`s UDP;)). Fast and simple)))

This is nice.

Thanks for sharing this rodego.

rodego wrote:

Code: Select all

Procedure.l GetIPByHost(Host$="")
  Result.l=0
  
  If Host$=""
    Host$=Hostname()
  EndIf
  
  SelfLoop=OpenNetworkConnection(Host$,0,#PB_Network_UDP)
  If SelfLoop
    Result=GetClientIP(SelfLoop)
    CloseNetworkConnection(SelfLoop)
  EndIf
  
  ProcedureReturn Result
EndProcedure

No real network connection (becouse it`s UDP;)). Fast and simple)))

What is it actually doing? (port 0)

EDIT:
Okay, I get it. The system has to resolve the IP (using whatever DNS server assigned to it) so your program is able to send UDP traffic too it
Sorry for being slow in my head this evening... I like your solution!

I once researched how to do the same without using any DNS server, but I never automated that procedure, hmm, maybe I should

Very cool hack, just tested and it works fine on WinXP/Win7/Linux, looks like a perfect way to resolve DNS, without messing with APIs, etc.

It is working with any port, not only 0.

And it also is strange that firewalls (Outpost Firewall Pro, windows default and maybe some others) have no any reaction to this. Well, that can be explained this way that DNS queries are sent from the name of svchost.exe on Windows, your program does nothing but calling OS api. So the only way to block it is to use proactive stuff to detect API calls, or to block svchost outcoming DNS queries, but then you will be unable to resolve any hostname from any app

Lunasole wrote:Very cool hack, just tested and it works fine on WinXP/Win7/Linux, looks like a perfect way to resolve DNS, without messing with APIs, etc

Perhaps this assertion is only correct if the remote site's firewall administrator indeed allows UDP connects?

With enabled unicode support, it is not working. Function OpenNetworkConnection returns 0.

User_Russian wrote:With enabled unicode support, it is not working. Function OpenNetworkConnection returns 0.

NOT confirmed. I use only the unicode compiler option, and the ip's are all correct !

I'm using Win 10 x64 here.

Bisonte wrote:

User_Russian wrote:With enabled unicode support, it is not working. Function OpenNetworkConnection returns 0.

NOT confirmed. I use only the unicode compiler option, and the ip's are all correct !

I'm using Win 10 x64 here.

Also NOT verified, Windows 7 x64 and Windows XP x86.

Maybe it's because of the Cyrillic alphabet. Function Hostname() returns "компьютер".
With disabled of support for Unicode, normal working. But if enable support for Unicode, the function OpenNetworkConnection returns 0.
Because of these bugs, I am opposed to exclusion support ascii. http://www.purebasic.fr/english/viewtop ... 14&t=60214

dell_jockey wrote: Perhaps this assertion is only correct if the remote site's firewall administrator indeed allows UDP connects?

No, nothing is sent to remote server, actually nothing is sent at all by application using this code, the only thing it does with network is regular DNS-query sent by OS [if needed and if possible]

User_Russian wrote:With enabled unicode support, it is not working. Function OpenNetworkConnection returns 0.

I'm always compiling with unicode, just finished my client-server based TCP tunneling app (using own simple protocol fully encrypted, to pack original stream), tested on 3 PCs over Internet [2x Win7 x64 and 1 XP x32, all using 32bit exe] and everything worked fine resolving DDNS-host with this stuff.
But of course need more detailed results to be sure, all that Win10/8/Vista, different linux builds, both for 32/64 etc.