[Winpcap-bugs] WinPCAP 4.1 beta on Vista, localhost

[Torsten Jaekel]

Dear Gianluca,
 
thank you for the reply:
1. yes, my traffic must be correct: I receive with WinPCAP and save into
file - error free. Just instead to write to file I send exactly the same
data to UDP socket: fails
    And as mentioned: if I send to IP address on different PC - error
free, only on localhost.
2. yes, it should not interfer, but I am pretty sure it does (or it gets
very slow and does not capture anymore all data if network on localhost
is used)
3. I mean driver: I send via Named Pipe to a BDA minidriver (from user
to kernel mode), fails in the same way like sending UDP to localhost on
WinSock
4. Capture statistics: sorry, have not yet checked (I guess you mean
WinPCAP statistics, other statistics should not be there, it is UDP and
no way to check lost packets
    without MPEG TS analysis, I see it is corrupt).
5. traffic is: 15 Mbps
6. It works fine if I read these TS packets from file and send it to UDP
and my pipe (bypassing WinPCAP).
    It seems to be the combination:
        - capturing via WinPCAP on an RNDIS device on localhost
        - sending as UDP to localhost
    both parts are error free, only the combination generates trouble
and the combinations works if the destination not localhost.
 
Let's guess I would see on statistics, WinPCAP cannot capture anymore
all packets. Do you have any advice how to improve and why the same code
is working on XP?
 
Best regards
 
Torsten
 

________________________________

From: Gianluca Varenni [mailto:gianluca.varenni at cacetech.com] 
Sent: Tuesday, November 13, 2007 5:34 PM
To: Torsten Jaekel; winpcap-bugs at winpcap.org
Subject: Re: [Winpcap-bugs] WinPCAP 4.1 beta on Vista, localhost


 

	----- Original Message ----- 
	From: Torsten Jaekel <mailto:tjaekel at broadcom.com>  
	To: winpcap-bugs at winpcap.org 
	Sent: Tuesday, November 13, 2007 1:41 AM
	Subject: [Winpcap-bugs] WinPCAP 4.1 beta on Vista, localhost

	Dear WinPCAP team,
	 
	I am using WinPCAP, version 4.1 beta in order to capture data on
an USB RNDIS device. It works fine on XP.
	On Vista (32 or 64 bit, on a Dual Core PC, I have strange
trouble:
	 
	- if I capture the data (it is a MPEG-2 Transport Stream) and
send it as UDP to another PC (leaving my PC) - all is fine
	- if I send it to "localhost" - the TS is corrupt, I have quite
a lot of lost TS packets (discontinuities).
	 

Have you checked if all the traffic is received before sending it to
your UDP socket?

	 
	I tried to use a FiFo, to increase the buffer sizes when opening
the PCAP device etc. Nothing helps.
	 
	It seems to me, traffic on localhost interfers with WinPCAP
driver. 
	 

Well, WinPcap sits in parallel with tcp/ip and cannot directly interfere
with it.

	 
	The same effect if I send the data via a Named Pipe to another
driver/thread.
	 

I think you meant "process/thread", instead of driver.

	 
	WinPCAP is error free, if I write the captured data into a file.
It happens only when UDP sockets are used with destination on the same
PC.
	If I stream and record into a file what I have streamed - I see
the corrupted data.
	 
	My assumption, sockets to localhost on Vista could be too slow,
does not seem to be true. I see that WinPCAP is still using timeouts in
case
	nothing was captured and the CPU load is not remarkable high.
	My software seems to be correct, just changing from file write
to UDP send with the same parameter creates this trouble.
	 
	Could there be a side effect, streaming to localhost? (but only
on Vista, on XP it works)?
	 

I don't think so. Have you checks the capture statistics and see if any
dropped packets are reported? What is the traffic rate you are dealing
with?
 
Have a nice day
GV

	 
	Sincerely yours
	 
	Torsten Jaekel
	 

	_______________________________________ 
	


	Torsten Jaekel

	Broadcom Corporation
	Call: +49 30 30 649 396
	Direct: +1 949 926 8016
	Cell: +49 174 94 33 716
	Email: tjaekel at broadcom.com 

	

	 

	
________________________________


	

	_______________________________________________
	Winpcap-bugs mailing list
	Winpcap-bugs at winpcap.org
	https://www.winpcap.org/mailman/listinfo/winpcap-bugs
	

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.winpcap.org/pipermail/winpcap-bugs/attachments/20071113/901c7f68/attachment-0001.htm