'm back...Snowden had litle level of access to information. couldn't plug in nothing, bring nothing inside...couldn't keystroke nothing...my wild guess...he sent a link trought the internal chatroom...OR

how to add http headers to a packet sniffed using scapy

....

f I understand correctly, the problem you're having is that you want to update an existing HTTP request with a new header. What you want is to update a string in place, which Python can't do directly (strings are immutable).

So what you should do is take the HTTP header:

old_hdr = pkt[Raw] or old_hdr = pkt[TCP].payload

and manipulate it like a string:

new_hdr = 'New Header: value'
hdr = old_hdr.split('\r\n') # This is a crappy hack. Parsing HTTP headers
hdr.insert(new_hdr, 2)      # is a [solved problem][1].
send_hdr = '\r\n'.join(hdr)
pkt[TCP].payload = send_hdr

If you find checksums are not updating, delete them before sending the packet:

del pkt[TCP].chksum

and Scapy will put them back for you, with the right values.

Edit: I just noticed that my link is fail. Here is how to parse HTTP headers.

https://stackoverflow.com/questions/13017797/how-to-add-http-headers-to-a-packet-sniffed-using-scapy?rq=1