Merge pull request #500 from kbandla/example_cleanup

using utils for DRY; cleaning up examples a bit

dpkt/utils.py

@@ -0,0 +1,41 @@
+"""Various Utility Functions"""
+import socket
+from .compat import compat_ord
+
+
+def mac_to_str(address):
+    """Convert a MAC address to a readable/printable string
+
+       Args:
+           address (str): a MAC address in hex form (e.g. '\x01\x02\x03\x04\x05\x06')
+       Returns:
+           str: Printable/readable MAC address
+    """
+    return ':'.join('%02x' % compat_ord(b) for b in address)
+
+
+def inet_to_str(inet):
+    """Convert inet object to a string
+
+        Args:
+            inet (inet struct): inet network address
+        Returns:
+            str: Printable/readable IP address
+    """
+    # First try ipv4 and then ipv6
+    try:
+        return socket.inet_ntop(socket.AF_INET, inet)
+    except ValueError:
+        return socket.inet_ntop(socket.AF_INET6, inet)
+
+
+def test_utils():
+    """Test the utility methods"""
+
+    print(mac_to_str(b'\x01\x02\x03\x04\x05\x06'))
+    assert mac_to_str(b'\x01\x02\x03\x04\x05\x06') == '01:02:03:04:05:06'
+    print(inet_to_str(b'\x91\xfe\xa0\xed'))
+    assert inet_to_str(b'\x91\xfe\xa0\xed') == '145.254.160.237'
+    ipv6_inet = b' \x01\r\xb8\x85\xa3\x00\x00\x00\x00\x8a.\x03ps4'
+    assert inet_to_str(ipv6_inet) == '2001:db8:85a3::8a2e:370:7334'
+    print('Success!')

examples/print_http_requests.py

@@ -1,4 +1,3 @@
-#!/usr/bin/env python
 """
 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
@@ -8,35 +7,9 @@
 """
 import dpkt
 import datetime
-import socket
-from dpkt.compat import compat_ord
+from dpkt.utils import mac_to_str, inet_to_str
 
 
-def mac_addr(address):
-    """Convert a MAC address to a readable/printable string
-
-       Args:
-           address (str): a MAC address in hex form (e.g. '\x01\x02\x03\x04\x05\x06')
-       Returns:
-           str: Printable/readable MAC address
-    """
-    return ':'.join('%02x' % compat_ord(b) for b in address)
-
-
-def inet_to_str(inet):
-    """Convert inet object to a string
-
-        Args:
-            inet (inet struct): inet network address
-        Returns:
-            str: Printable/readable IP address
-    """
-    # First try ipv4 and then ipv6
-    try:
-        return socket.inet_ntop(socket.AF_INET, inet)
-    except ValueError:
-        return socket.inet_ntop(socket.AF_INET6, inet)
-
 def print_http_requests(pcap):
     """Print out information about each packet in a pcap
 
@@ -76,7 +49,7 @@ def print_http_requests(pcap):
 
             # Print out the info
             print('Timestamp: ', str(datetime.datetime.utcfromtimestamp(timestamp)))
-            print('Ethernet Frame: ', mac_addr(eth.src), mac_addr(eth.dst), eth.type)
+            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))

examples/print_icmp.py

@@ -4,35 +4,9 @@
 """
 import dpkt
 import datetime
-import socket
-from dpkt.compat import compat_ord
+from dpkt.utils import mac_to_str, inet_to_str
 
 
-def mac_addr(address):
-    """Convert a MAC address to a readable/printable string
-
-       Args:
-           address (str): a MAC address in hex form (e.g. '\x01\x02\x03\x04\x05\x06')
-       Returns:
-           str: Printable/readable MAC address
-    """
-    return ':'.join('%02x' % compat_ord(b) for b in address)
-
-
-def inet_to_str(inet):
-    """Convert inet object to a string
-
-        Args:
-            inet (inet struct): inet network address
-        Returns:
-            str: Printable/readable IP address
-    """
-    # First try ipv4 and then ipv6
-    try:
-        return socket.inet_ntop(socket.AF_INET, inet)
-    except ValueError:
-        return socket.inet_ntop(socket.AF_INET6, inet)
-
 def print_icmp(pcap):
     """Print out information about each packet in a pcap
 
@@ -64,10 +38,12 @@ def print_icmp(pcap):
 
             # Print out the info
             print('Timestamp: ', str(datetime.datetime.utcfromtimestamp(timestamp)))
-            print( 'Ethernet Frame: ', mac_addr(eth.src), mac_addr(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('ICMP: type:%d code:%d checksum:%d data: %s\n' % (icmp.type, icmp.code, icmp.sum, repr(icmp.data)))
+            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('ICMP: type:%d code:%d checksum:%d data: %s\n' %
+                  (icmp.type, icmp.code, icmp.sum, repr(icmp.data)))
 
 
 def test():

examples/print_packets.py

@@ -1,39 +1,12 @@
-#!/usr/bin/env python
 """
 Use DPKT to read in a pcap file and print out the contents of the packets
 This example is focused on the fields in the Ethernet Frame and IP packet
 """
 import dpkt
 import datetime
-import socket
-from dpkt.compat import compat_ord
+from dpkt.utils import mac_to_str, inet_to_str
 
 
-def mac_addr(address):
-    """Convert a MAC address to a readable/printable string
-
-       Args:
-           address (str): a MAC address in hex form (e.g. '\x01\x02\x03\x04\x05\x06')
-       Returns:
-           str: Printable/readable MAC address
-    """
-    return ':'.join('%02x' % compat_ord(b) for b in address)
-
-
-def inet_to_str(inet):
-    """Convert inet object to a string
-
-        Args:
-            inet (inet struct): inet network address
-        Returns:
-            str: Printable/readable IP address
-    """
-    # First try ipv4 and then ipv6
-    try:
-        return socket.inet_ntop(socket.AF_INET, inet)
-    except ValueError:
-        return socket.inet_ntop(socket.AF_INET6, inet)
-
 def print_packets(pcap):
     """Print out information about each packet in a pcap
 
@@ -48,7 +21,7 @@ def print_packets(pcap):
 
         # Unpack the Ethernet frame (mac src/dst, ethertype)
         eth = dpkt.ethernet.Ethernet(buf)
-        print('Ethernet Frame: ', mac_addr(eth.src), mac_addr(eth.dst), eth.type)
+        print('Ethernet Frame: ', mac_to_str(eth.src), mac_to_str(eth.dst), eth.type)
 
         # Make sure the Ethernet data contains an IP packet
         if not isinstance(eth.data, dpkt.ip.IP):
@@ -65,8 +38,9 @@ def print_packets(pcap):
         fragment_offset = ip.off & dpkt.ip.IP_OFFMASK
 
         # Print out the info
-        print('IP: %s -> %s   (len=%d ttl=%d DF=%d MF=%d offset=%d)\n' % \
-              (inet_to_str(ip.src), inet_to_str(ip.dst), ip.len, ip.ttl, do_not_fragment, more_fragments, fragment_offset))
+        print('IP: %s -> %s   (len=%d ttl=%d DF=%d MF=%d offset=%d)\n' %
+              (inet_to_str(ip.src), inet_to_str(ip.dst), ip.len, ip.ttl,
+               do_not_fragment, more_fragments, fragment_offset))
 
 
 def test():