Working showing version of checksums

bin/checksum_delta_diff_test.py

@@ -16,11 +16,16 @@ def checksum_scapy(pkt):
     s = ~s
     return (((s>>8)&0xff)|s<<8) & 0xffff
 
-
+# a) Compare for TCP, UDP -> IPv6 does not have checksum!
 # 1. convert to array of "bytes"
 # 2. import into an array
 # 3. sum everything up
+# b) Generate checksum from v4 offset and IPv6 for IPv4
 
+# a)
+# UDP/TCP CONTENT stays the same
+# Only the diff between v4 and v6 "counts"
+#
 
 def sum_for_udp(packet):
     sums = ""
@@ -52,7 +57,7 @@ def sum_for_v6(packet):
     sums += struct.pack("H", packet[IPv6].plen)
     sums += struct.pack("B", packet[IPv6].nh)
 
-    print("{} - {} - {}".format(len(sums), sums, checksum_scapy(sums)))
+#    print("{} - {} - {}".format(len(sums), sums, checksum_scapy(sums)))
 
     return sums
 
@@ -99,31 +104,81 @@ if __name__ == '__main__':
     d0 = ""
     d = "A"
 
-    p.append(e / i4 / u / d)
+    p6_udp = e / i6 / u / d
-    p.append(e / i6 / u / d)
+    p6_udp2 = e / i62 / u / d
-    p.append(e / i62 / u / d)
+    p4_udp = e / i4 / u / d
 
-    for packet in p:
+    p4_p6_1 = {
-        print("p = {}".format(packet.__repr__()))
+        "ipv6": p6_udp,
-        packet_rebuild = packet.__class__(str(packet))
+        "ipv4": p4_udp
-        print("rebuild = {}".format(packet_rebuild.__repr__()))
+    }
-        chk_old = packet[UDP].chksum
+    p.append(p4_p6_1)
-        chk_new = packet_rebuild[UDP].chksum
-        print("chk1 = {} chk2={}".format(chk_old, chk_new))
 
-        sums = ""
+    p4_p6_2 = {
+        "ipv6": p6_udp2,
+        "ipv4": p4_udp
+    }
+    p.append(p4_p6_2)
 
-        if IP in packet:
+    #p.append(e / i62 / u / d)
-            sums += sum_for_v4(packet_rebuild)
-        if IPv6 in packet:
-            sums += sum_for_v6(packet_rebuild)
-#        if UDP in packet:
-#            sums += sum_for_udp(packet_rebuild)
-
-        print("Checksum-parts {} for {}".format(checksum_scapy(sums), packet_rebuild.__repr__()))
 
 
-# Checksums:
+
+    for p_pair in p:
+        v6 = p_pair["ipv6"]
+        v4 = p_pair["ipv4"]
+
+        checksums = {}
+        header_checksums = {}
+        diff_ip_headers = 0
+
+        for packet in [v6, v4]:
+            #print("p = {}".format(packet.__repr__()))
+            packet_rebuild = packet.__class__(str(packet))
+            print("rebuild = {}".format(packet_rebuild.__repr__()))
+            chk_old = packet[UDP].chksum
+            chk_new = packet_rebuild[UDP].chksum
+            # print("chk1 = {} chk2={}".format(chk_old, chk_new))
+
+            sums = ""
+
+
+            if IPv6 in packet:
+                headertype = "ipv6"
+                sums += sum_for_v6(packet_rebuild)
+
+                if UDP in packet:
+                    checksums["ipv6"] = packet_rebuild[UDP].chksum
+
+            if IP in packet:
+                headertype = "ipv4"
+                sums += sum_for_v4(packet_rebuild)
+
+                if UDP in packet:
+                    checksums["ipv4"] = packet_rebuild[UDP].chksum
+
+            header_checksums[headertype] = checksum_scapy(sums)
+            print("Checksum-parts {} for {}".format(checksum_scapy(sums), packet_rebuild.__repr__()))
+
+        print("UDP v6: {} v4: {} diff: {}".format(checksums["ipv6"],
+                                                  checksums["ipv4"],
+                                                  checksums["ipv6"] - checksums["ipv4"]))
+
+        print("Header v6: {} v4: {} diff: {}".format(header_checksums["ipv6"],
+                                                     header_checksums["ipv4"],
+                                                     header_checksums["ipv6"] - header_checksums["ipv4"]))
+
+        p
+
+        # if UDP in packet:
+        #     sums += sum_for_udp(packet_rebuild)
+        # if TCP in packet:
+        #     sums += sum_for_udp(packet_rebuild)
+
+
+
+#            diff_total += packet_rebuild[IP].chksum
+#            diff_total -= packet_rebuild[IPv6].chksum# Checksums:
 # - tcp
 # - udp
 # - icmp6