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<p class=MsoNormal><font size=2 face=굴림><span lang=EN-US
style='font-size:10.0pt;font-family:Gulim'>Hi.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=굴림><span lang=EN-US
style='font-size:10.0pt;font-family:Gulim'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=굴림><span lang=EN-US
style='font-size:10.0pt;font-family:Gulim'>In special network condition, I
found that TPROXY didn</span></font><font face=Arial><span lang=EN-US
style='font-family:Arial'>’</span></font><font face=굴림><span
lang=EN-US style='font-family:Gulim'>t work. <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=굴림><span lang=EN-US
style='font-size:10.0pt;font-family:Gulim'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=굴림><span lang=EN-US
style='font-size:10.0pt;font-family:Gulim'>I tried to change source ip to
another using below code.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=굴림><span lang=EN-US
style='font-size:10.0pt;font-family:Gulim'>==================== CODE START ========================<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=굴림><span lang=EN-US
style='font-size:10.0pt;font-family:Gulim'>itp.op
= TPROXY_ASSIGN;<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=굴림><span lang=EN-US
style='font-size:10.0pt;font-family:Gulim'>itp.v.addr.faddr = (another);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=굴림><span lang=EN-US
style='font-size:10.0pt;font-family:Gulim'>itp.v.addr.fport = htons(0);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=굴림><span lang=EN-US
style='font-size:10.0pt;font-family:Gulim'>setsockopt(s, SOL_IP, IP_TPROXY,
&itp, sizeof(itp));<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=굴림><span lang=EN-US
style='font-size:10.0pt;font-family:Gulim'>itp.op
= TPROXY_FLAGS;<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=굴림><span lang=EN-US
style='font-size:10.0pt;font-family:Gulim'>itp.v.flags = ITP_CONNECT;<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=바탕><span lang=EN-US
style='font-size:10.0pt'>setsockopt(s, SOL_IP, IP_TPROXY, &itp, sizeof(itp));<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=굴림><span lang=EN-US
style='font-size:10.0pt;font-family:Gulim'>==================== CODE END ==========================<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=바탕><span lang=EN-US
style='font-size:10.0pt'>It goes well when general TCP/IP state.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=바탕><span lang=EN-US
style='font-size:10.0pt'>But in case tcp sequence number of received packet is something
wierd, <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=바탕><span lang=EN-US
style='font-size:10.0pt'>LINUX tcp/ip stack make be zero sequence number and
ack number.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=바탕><span lang=EN-US
style='font-size:10.0pt'>And source ip address is not changed !!!<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=바탕><span lang=EN-US
style='font-size:10.0pt'>Of cource other sessions</span></font><font
face="Times New Roman"><span lang=EN-US style='font-family:"Times New Roman"'>’</span></font><span
lang=EN-US>s source ip address is changed very well.<o:p></o:p></span></p>
<p class=MsoNormal><font size=2 face=바탕><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=바탕><span lang=EN-US
style='font-size:10.0pt'>Especially only if I connect to windows system, this
is occurred. <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=바탕><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=바탕><span lang=EN-US
style='font-size:10.0pt'>My System Info:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=바탕><span lang=EN-US
style='font-size:10.0pt'>O S : linux-2.6.9<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=바탕><span lang=EN-US
style='font-size:10.0pt'>TRPOXY verserion : 2.0.1<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=바탕><span lang=EN-US
style='font-size:10.0pt'>ETC. : Using Bridge network<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=바탕><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=바탕><span lang=EN-US
style='font-size:10.0pt'>Now, I am studying TCP/IP kernel stack. And My eyes
and my head is very dizzy.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=바탕><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=바탕><span lang=EN-US
style='font-size:10.0pt'>Thanks.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=바탕><span lang=EN-US><o:p> </o:p></span></font></p>
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