blob: 145faea079f746adaa6a2db523ea4f5de61dc202 [file] [log] [blame]
This example expands on the print_packets example. It checks for HTTP request headers and displays their contents.
NOTE: We are not reconstructing 'flows' so the request (and response if you tried to parse it) will only
parse correctly if they fit within a single packet. Requests can often fit in a single packet but
Responses almost never will. For proper reconstruction of flows you may want to look at other projects
that use DPKT ( and others)
import dpkt
import datetime
from dpkt.utils import mac_to_str, inet_to_str
def print_http_requests(pcap):
"""Print out information about each packet in a pcap
pcap: dpkt pcap reader object (dpkt.pcap.Reader)
# For each packet in the pcap process the contents
for timestamp, buf in pcap:
# Unpack the Ethernet frame (mac src/dst, ethertype)
eth = dpkt.ethernet.Ethernet(buf)
# Make sure the Ethernet data contains an IP packet
if not isinstance(, dpkt.ip.IP):
print('Non IP Packet type not supported %s\n' %
# Now grab the data within the Ethernet frame (the IP packet)
ip =
# Check for TCP in the transport layer
if isinstance(, dpkt.tcp.TCP):
# Set the TCP data
tcp =
# Now see if we can parse the contents as a HTTP request
request = dpkt.http.Request(
except (dpkt.dpkt.NeedData, dpkt.dpkt.UnpackError):
# Pull out fragment information (flags and offset all packed into off field, so use bitmasks)
do_not_fragment = bool( & dpkt.ip.IP_DF)
more_fragments = bool( & dpkt.ip.IP_MF)
fragment_offset = & dpkt.ip.IP_OFFMASK
# Print out the info
print('Timestamp: ', str(datetime.datetime.utcfromtimestamp(timestamp)))
print('Ethernet Frame: ', mac_to_str(eth.src), mac_to_str(eth.dst), eth.type)
print('IP: %s -> %s (len=%d ttl=%d DF=%d MF=%d offset=%d)' %
(inet_to_str(ip.src), inet_to_str(ip.dst), ip.len, ip.ttl, do_not_fragment, more_fragments, fragment_offset))
print('HTTP request: %s\n' % repr(request))
# Check for Header spanning acrossed TCP segments
if not'\r\n'):
print('\nHEADER TRUNCATED! Reassemble TCP segments!\n')
def test():
"""Open up a test pcap file and print out the packets"""
with open('data/http.pcap', 'rb') as f:
pcap = dpkt.pcap.Reader(f)
if __name__ == '__main__':