Begin to introduce commented out code, use metadata

bin/checksum_from_scapy.py

@@ -23,6 +23,8 @@ else:
         # create array with unsigned shorts,
         # sum it up -> results in 16 bit uint (?)
         s = sum(array.array("H", pkt))
+        print("sum={}".format(s))
+        # This step is understood
 
         # (s & 0xffff) -> mask for 16 bit, truncate rest
         # (s >> 16) right shift by 16 bits
@@ -40,7 +42,6 @@ else:
         # over bits from the previous calculation
         s += s >> 16
 
-
         # according to https://stackoverflow.com/questions/8305199/the-tilde-operator-in-python
         # ~ is the bitwise complement operator in python
         # which essentially calculates -x - 1
@@ -65,3 +66,6 @@ if __name__ == '__main__':
     pkt_bytes = pkt.encode('utf-8')
     print(pkt_bytes)
     print(checksum(pkt_bytes))
+
+    ipv4 = "AAAA"
+    ipv6 = "BBAA"

doc/plan.org

@@ -358,8 +358,30 @@
 |            | - 15m q&a                                                                  |       |
 |            |                                                                            |       |
 |            |                                                                            |       |
+| 2019-06-24 |                                                                            |       |
+|            | Laurent meeting                                                            |       |
+|            |                                                                            |       |
+|            | Checksums                                                                  |       |
+|            | - 16 bit sum of fields, later one/two complement                           |       |
+|            | - various implementations                                                  |       |
+|            | - is a sum -> commutative law                                              |       |
+|            | - overflow (delta > payload) handling unclear                              |       |
+|            |                                                                            |       |
+|            | Netpfga                                                                    |       |
+|            | - Old one had several failure messages (one in DDR area)                   |       |
+|            | - New one: tables can be written                                           |       |
+|            | - Need 3 ports: v4, v6, management                                         |       |
+|            |                                                                            |       |
+|            | Next steps:                                                                |       |
+|            | - Test checksums delta on software switch                                  |       |
+|            | - Begin to port code to netpfga one-by-one                                 |       |
+|            |                                                                            |       |
+|            | Follow up notes:                                                           |       |
+|            | - Checkout Hendrik thesis / right / left shift                             |       |
+|            | - Fix computer in lab                                                      |       |
 |            |                                                                            |       |
-| 2018-06-27 |                                                                            |       |
+|            |                                                                            |       |
+| 2019-06-27 |                                                                            |       |
 |            | Target Hardware: code running                                              |       |
 |            |                                                                            |       |
 | 2019-07-11 |                                                                            |       |
@@ -3000,6 +3022,76 @@ b'AAAA'
 [14:18] line:bin% python3 checksum_from_scapy.py BBAA
 b'BBAA'
 31868
+[14:18] line:bin% python3 checksum_from_scapy.py AA
+b'AA'
+48830
+[14:20] line:bin% python3 checksum_from_scapy.py BB
+b'BB'
+48573
+>>> bin(48830)
+'0b1011111010111110'
+>>> bin(48573)
+'0b1011110110111101'
+>>>
+
+>>> array.array("H", "AAAA".encode("utf-8"))
+array('H', [16705, 16705])
+>>> array.array("H", "AA".encode("utf-8"))
+array('H', [16705])
+
+-> bit concat on 16:
+AA:
+>>> 0b100000101000001
+16705
+
+Order in 16 bit tuples does not matter:
+
+[14:24] line:bin% python3 checksum_from_scapy.py AABB
+b'AABB'
+sum=33667
+31868
+[14:28] line:bin% python3 checksum_from_scapy.py BBAA
+b'BBAA'
+sum=33667
+31868
+
+[14:28] line:bin% python3 checksum_from_scapy.py BBCCAA
+b'BBCCAA'
+sum=50886
+14649
+[14:28] line:bin% python3 checksum_from_scapy.py BBAACC
+b'BBAACC'
+sum=50886
+14649
+
+Sum on shorts does not stay in short area:
+
+>>> sum(array.array("H", [48830, 48573]))
+97403
+>>> sum(array.array("H", "AAAA".encode("utf-8")))
+33410
+>>> sum(array.array("H", "AABB".encode("utf-8")))
+33667
+>>> sum(array.array("H", "AABBCC".encode("utf-8")))
+50886
+>>> sum(array.array("H", "AABBCCDD".encode("utf-8")))
+68362
+
+Adding with overflow control works:
+
+>>> s = 97403
+>>> s = (s >> 16) + (s & 0xffff)
+>>> s
+31868
+>>> s += s >> 16
+>>> s
+31868
+
+[14:29] line:bin% python3 checksum_from_scapy.py AABB
+b'AABB'
+sum=33667
+31868
+
 
 #+END_CENTER
 *** TODO Get ANY p4 program to successfully run on netpfga

netpfga/minip4/src/minip4_solution.p4

@@ -1 +1 @@
-minip4_solution-v6zero.p4
+minip4_solution-nat64.p4

netpfga/minip4/src/settings.p4

@@ -0,0 +1 @@
+../../../p4src/settings.p4

p4src/settings.p4

@@ -10,5 +10,6 @@
 #define ICMP6_TABLE_SIZE 64                                 /* icmp6 handlers */
 #define ICMP_TABLE_SIZE 64                                 /* icmp6 handlers */
 #define NAT64_TABLE_SIZE 64                                 /* nat64 and nat46 entries */
+#define TEST_TABLE_SIZE 64                                 /* nat64 and nat46 entries */
 
 #endif