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<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>Hi,<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>This is what the code looks like
– <o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>This is all initialization code –
<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> if ((adhandle=
pcap_open_live(d->name, // name of the device<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> 65536, //
portion of the packet to capture. <o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> //
65536 grants that the whole packet will be captured on all the MACs.<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> 1, //
promiscuous mode (nonzero means promiscuous)<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> 1, //
read timeout<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> errbuf //
error buffer<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> ))
== NULL)<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> {<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> printf("\nUnable
to open the adapter. %s is not supported by WinPcap\n", d->name);<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> <o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> return
RETCODE_ERR;<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> }<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> //Set the filter
string to the source ip address<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> //Only packets
from this source address will be captured.<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> //This does slow
down the capture a bit.<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> NetMask=0xffffff;<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> filter = "src
192.168.1.10";<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> <o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> if(pcap_compile(adhandle,
&fcode, filter, 1, NetMask) < 0)<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> {<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> printf("\nError
compiling filter: wrong syntax.\n");<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> pcap_close(adhandle);<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> return
RETCODE_ERR;<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> }<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> if(pcap_setfilter(adhandle,
&fcode)<0)<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> {<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> printf("\nError
setting the filter\n");<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> pcap_close(adhandle);<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> return
RETCODE_ERR;<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> }
<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> <o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> //Set the kernel
buffer<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> <o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> if
(pcap_setbuff(adhandle,41943040) < 0)<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> {<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> printf("\n
unable to set buffer");<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> <o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> return
RETCODE_ERR;<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> }<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>Then I start the pcap_loop on a separate
thread – This function is called for each packet capture.<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>I copy the data for all packets
in a global array – image_buf <o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>void packet_handler(u_char
*dumpfileHandler, const struct pcap_pkthdr *header, const u_char *pkt_data)<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>{<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> //copy the packet data to
image_buf and also store the packet length<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> <o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> image_buf[packetCounter] =
(unsigned char*)(malloc(header->caplen*sizeof(unsigned char)));<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> if(image_buf[packetCounter] ==
NULL)<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> { <o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> printf("\n
unable to allocate buffer");<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> return;<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> }<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> memcpy(image_buf[packetCounter],pkt_data,header->caplen);<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> pkt_length[packetCounter]=header->caplen;<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> <o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'> packetCounter += 1; <o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>}<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>Please let me know if you need
more details. I can zip and send the code file if needed.<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>Thanks<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>Charu<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<div>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'>
<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
winpcap-users-bounces@winpcap.org [mailto:winpcap-users-bounces@winpcap.org] <b>On
Behalf Of </b>Gianluca Varenni<br>
<b>Sent:</b> Tuesday, April 21, 2009 1:51 PM<br>
<b>To:</b> winpcap-users@winpcap.org<br>
<b>Subject:</b> Re: [Winpcap-users] Better Performance<o:p></o:p></span></p>
</div>
</div>
<p class=MsoNormal><o:p> </o:p></p>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Times New Roman","serif"'>Before
trying to modify the WinPcap source code, I would try to understand what the
bottlenecks are. What are you doing with the received packets?</span><span
style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Times New Roman","serif"'>Can
you show us the packet processing loop that you have in your code (even in form
of pseudocode)?</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Times New Roman","serif"'>Have
a nice day</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Times New Roman","serif"'>GV</span><span
style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
</div>
<blockquote style='border:none;border-left:solid black 1.5pt;padding:0in 0in 0in 4.0pt;
margin-left:3.75pt;margin-top:5.0pt;margin-right:0in;margin-bottom:5.0pt'>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>-----
Original Message ----- <o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal style='background:#E4E4E4'><b><span style='font-size:10.0pt;
font-family:"Arial","sans-serif"'>From:</span></b><span style='font-size:10.0pt;
font-family:"Arial","sans-serif"'> <a href="mailto:cagrawal@altasens.com"
title="cagrawal@altasens.com">Charu Agrawal</a> <o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>To:</span></b><span
style='font-size:10.0pt;font-family:"Arial","sans-serif"'> <a
href="mailto:winpcap-users@winpcap.org" title="winpcap-users@winpcap.org">winpcap-users@winpcap.org</a>
<o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Sent:</span></b><span
style='font-size:10.0pt;font-family:"Arial","sans-serif"'> Monday, April 20,
2009 10:58 AM<o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Subject:</span></b><span
style='font-size:10.0pt;font-family:"Arial","sans-serif"'> [Winpcap-users]
Better Performance<o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p> </o:p></span></p>
</div>
<p class=MsoNormal>Hi,<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>I am trying to figure out how to capture image frames most efficiently.
Each frame is approximately 20Mbytes.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>I am trying to achieve frame rate of 1-2 frames per second.
The packets are being received over a Gig eth dedicated link. ( Packets
are sent over that link using only one source).<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>I am unable to achieve this frame rate using winpcap. Would
it be helpful to modify the Winpcap source code for better performance ? Has
anyone here have any experience in modifying the winpcap source to achieve
higher frame rate capture ?<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Thanks for your help in advance<o:p></o:p></p>
<p class=MsoNormal>Regards<o:p></o:p></p>
<p class=MsoNormal>Charu Agrawal<o:p></o:p></p>
<div class=MsoNormal align=center style='text-align:center'><span
style='font-size:12.0pt;font-family:"Times New Roman","serif"'>
<hr size=2 width="100%" align=center>
</span></div>
<p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'>_______________________________________________<br>
Winpcap-users mailing list<br>
Winpcap-users@winpcap.org<br>
https://www.winpcap.org/mailman/listinfo/winpcap-users<o:p></o:p></span></p>
</blockquote>
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