Initial commit

1 files changed, 98 insertions, 0 deletions

diff --git a/external/construct/protocols/layer3/icmpv4.py b/external/construct/protocols/layer3/icmpv4.py
new file mode 100644
index 0000000..2c0715e
--- /dev/null
+++ b/external/construct/protocols/layer3/icmpv4.py
@@ -0,0 +1,98 @@
+"""
+Internet Control Message Protocol for IPv4 (TCP/IP protocol stack)
+"""
+from construct import *
+from ipv4 import IpAddress
+from binascii import unhexlify
+import six
+
+
+echo_payload = Struct("echo_payload",
+    UBInt16("identifier"),
+    UBInt16("sequence"),
+    Bytes("data", 32), # length is implementation dependent... 
+                       # is anyone using more than 32 bytes?
+)
+
+dest_unreachable_payload = Struct("dest_unreachable_payload",
+    Padding(2),
+    UBInt16("next_hop_mtu"),
+    IpAddress("host"),
+    Bytes("echo", 8),
+)
+
+dest_unreachable_code = Enum(Byte("code"),
+    Network_unreachable_error = 0,
+    Host_unreachable_error = 1,
+    Protocol_unreachable_error = 2,
+    Port_unreachable_error = 3,
+    The_datagram_is_too_big = 4,
+    Source_route_failed_error = 5,
+    Destination_network_unknown_error = 6,
+    Destination_host_unknown_error = 7,
+    Source_host_isolated_error = 8,
+    Desination_administratively_prohibited = 9,
+    Host_administratively_prohibited2 = 10,
+    Network_TOS_unreachable = 11,
+    Host_TOS_unreachable = 12,
+)
+
+icmp_header = Struct("icmp_header",
+    Enum(Byte("type"),
+        Echo_reply = 0,
+        Destination_unreachable = 3,
+        Source_quench = 4,
+        Redirect = 5,
+        Alternate_host_address = 6,
+        Echo_request = 8,
+        Router_advertisement = 9,
+        Router_solicitation = 10,
+        Time_exceeded = 11,
+        Parameter_problem = 12,
+        Timestamp_request = 13,
+        Timestamp_reply = 14,
+        Information_request = 15,
+        Information_reply = 16,
+        Address_mask_request = 17,
+        Address_mask_reply = 18,
+        _default_ = Pass,
+    ),
+    Switch("code", lambda ctx: ctx.type, 
+        {
+            "Destination_unreachable" : dest_unreachable_code,
+        },
+        default = Byte("code"),
+    ),
+    UBInt16("crc"),
+    Switch("payload", lambda ctx: ctx.type, 
+        {
+            "Echo_reply" : echo_payload,
+            "Echo_request" : echo_payload,
+            "Destination_unreachable" : dest_unreachable_payload,
+        }, 
+        default = Pass
+    )
+)
+
+
+if __name__ == "__main__":
+    cap1 = unhexlify(six.b("0800305c02001b006162636465666768696a6b6c6d6e6f70717273747576776162"
+        "63646566676869"))
+    cap2 = unhexlify(six.b("0000385c02001b006162636465666768696a6b6c6d6e6f70717273747576776162"
+        "63646566676869"))
+    cap3 = unhexlify(six.b("0301000000001122aabbccdd0102030405060708"))
+    
+    print (icmp_header.parse(cap1))
+    print (icmp_header.parse(cap2))
+    print (icmp_header.parse(cap3))
+
+
+
+
+
+
+
+
+
+
+