title: where icmp.c checks expires
body: <p>In <code>kernel-3.0.26 code net/ipv6/icmp.c</code>, while sending ICMP reply where it checks for the timer expiry. It should check the value give by a router advertisement right? I think the expiry value is stored in <code>rt-&gt;rt6_expires</code> in <code>ndisc.c</code> (line no: 1284). Then while sending an ICMP reply, it should check with the expiry timer right? Where that checking is done? Please somebody explain me.</p>
  
  <p>Thank you in advance. sorry for my bad english.</p>