title: Specifying packet length with scapy
body: <p>I'm trying to send a specific packet size (100 bytes) with <code>scapy</code> but cant seem to get it. </p>
  
  <p>I'm using this to start. </p>
  
  <pre><code>sr(IP(dst="192.168.1.1")/TCP(dport=443))
  </code></pre>
  
  <p>Looking at the docs / help I cant tell if I can use <code>PacketLenField</code> to specify the length of the packet. I can do it with NMAP &amp; NSE but would like to do it outside of NMAP. </p>
  
  <p>Any ideas on this one?</p>
  
  <p>Thanks!</p>