<div> I hope I am not misleading you.</div>
<div> But I don't think there is padding on the tcp data.</div>
<div> padding is only inside the header , before the tcp data begins.</div>
<div> any way , you can use the total length field from the ip header + calculations</div>
<div> to find the data length.<br><br> </div>
<div><span class="gmail_quote">On 4/1/06, <b class="gmail_sendername">Krzysztof Włodarczyk</b> <<a href="mailto:krwl@wp.pl">krwl@wp.pl</a>> wrote:</span>
<blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">Hi,<br><br>my problem is how to find out where, in a tcp packet, finishes tcp data, and begins a padding??
<br><br>for example I have the following packet:<br>00 50 fc a1 50 cb 00 30 4f 18 3a d8 08 00 45 00<br>00 2d 47 52 40 00 3a 06 fd 60 d4 4d 65 a6 c0 a8<br>01 7c 00 6e 08 a9 0c f8 00 cc 62 09 bd db 50 18<br>16 d0 e5 c2 00 00 2b 4f 4b 0d 0a 62
<br><br>where:<br>00 50 fc a1 50 cb 00 30 4f 18 3a d8 08 00<br>-is an Ethernet header<br><br> 45 00<br>00 2d 47 52 40 00 3a 06 fd 60 d4 4d 65 a6 c0 a8<br>01 7c<br>-is an IPv4 header
<br><br> 00 6e 08 a9 0c f8 00 cc 62 09 bd db 50 18<br>16 d0 e5 c2 00 00<br>-is a TCP header<br><br>2b 4f 4b 0d 0a<br>-is TCP data<br><br>and finally:<br>62<br>-is a padding rubbish<br><br>The two TCP crc-s:<br>without rubbish: 0xe5c2 - ok
<br>with rubbish: 0xe55f - wrong<br><br>And my question: is there any method that can tell me where the padding begins? (other than counting multiple CRC and comparing it to a proper TCP field;))<br><br>----------------------------------------------------
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