In theory: implement NAT64 from v6 to v4 without externs

doc/plan.org

@@ -5632,7 +5632,33 @@ PCAP files to prove it works:
  create mode 100644 pcap/tcp-udp-delta-2019-07-17-1558-h3.pcap
 
 #+END_CENTER
-***
+*** TODO 2019-07-21: fix "compilation error" on minip4 / netpfga
+#+BEGIN_CENTER
+source tcl/export_hardware.tcl
+# set design [lindex $argv 0]
+# puts "\nOpening $design XPR project\n"
+
+Opening simple_sume_switch XPR project
+
+# open_project project/$design.xpr
+Scanning sources...
+Finished scanning sources
+INFO: [IP_Flow 19-234] Refreshing IP repositories
+INFO: [IP_Flow 19-1700] Loaded user IP repository '/home/nico/projects/P4-NetFPGA/contrib-projects/sume-sdnet-switch/projects/minip4/simple_sume_switch/hw/ip_repo'.
+INFO: [IP_Flow 19-2313] Loaded Vivado IP repository '/opt/Xilinx/Vivado/2018.2/data/ip'.
+WARNING: [IP_Flow 19-3664] IP 'bd_7ad4_xpcs_0' generated file not found '/home/nico/projects/P4-NetFPGA/contrib-projects/sume-sdnet-switch/projects/minip4/simple_sume_switch/hw/.Xil/Vivado-10327-nsg-System/coregen/bd_7ad4_xpcs_0_1/elaborate/configure_gt.tcl'. Please regenerate to continue.
+WARNING: [IP_Flow 19-3664] IP 'bd_a1aa_xpcs_0' generated file not found '/home/nico/projects/P4-NetFPGA/contrib-projects/sume-sdnet-switch/projects/minip4/simple_sume_switch/hw/.Xil/Vivado-10327-nsg-System/coregen/bd_a1aa_xpcs_0_2/elaborate/configure_gt.tcl'. Please regenerate to continue.
+open_project: Time (s): cpu = 00:00:05 ; elapsed = 00:00:05 . Memory (MB): peak = 1365.707 ; gain = 188.977 ; free physical = 10151 ; free virtual = 15581
+# puts "\nOpening $design Implementation design\n"
+
+Opening simple_sume_switch Implementation design
+
+# open_run impl_1
+ERROR: [Common 17-69] Command failed: Run 'impl_1' has not been launched. Unable to open
+Vivado%
+Vivado%
+#+END_CENTER
+*** TODO 2019-07-21: whether or not to handle icmp(6) checksums
 ** The NetPFGA saga
 Problems encountered:
 - The logfile for a compile run is 10k+ lines

p4src/actions_delta_checksum.p4

@@ -1,8 +1,6 @@
 #ifndef NICO_DELTA_CHECKSUM
 #define NICO_DELTA_CHECKSUM
 
-
-
 #include "headers.p4"
 
 action v4sum() {
@@ -128,6 +126,10 @@ action delta_ipv4_from_v6_to_v4()
 {
     bit<16> tmp = 0;
 
+   /* we don't have ANY checksum, but tcp or udp: we can
+       base on that ones for calculating the diff for IPv4
+
+    Does NOT contain payload! -> can be done manually */
 
     tmp = tmp + (bit<16>) hdr.ipv4.version;          /* 4 bit */
 	tmp = tmp + (bit<16>) hdr.ipv4.ihl;              /* 4 bit */
@@ -136,18 +138,15 @@ action delta_ipv4_from_v6_to_v4()
     tmp = tmp + (bit<16>) hdr.ipv4.totalLen;         /* 16 bit */
     tmp = tmp + (bit<16>) hdr.ipv4.identification;   /* 16 bit */
     tmp = tmp + (bit<16>) hdr.ipv4.flags;            /* 3 bit */
-    /* we don't have ANY checksum, but tcp or udp: we can
+    tmp = tmp + (bit<16>) hdr.ipv4.fragOffset;       /* 13 bit */
-       base on that ones for calculating the diff for IPv4
+    tmp = tmp + (bit<16>) hdr.ipv4.ttl;              /* 8 bit */
+    tmp = tmp + (bit<16>) hdr.ipv4.protocol;         /* 8 bit */
+    tmp = tmp + (bit<16>) hdr.ipv4.src_addr[15:0];   /* 16 bit */
+    tmp = tmp + (bit<16>) hdr.ipv4.src_addr[31:16];  /* 16 bit */
+    tmp = tmp + (bit<16>) hdr.ipv4.dst_addr[15:0];   /* 16 bit */
+    tmp = tmp + (bit<16>) hdr.ipv4.dst_addr[31:16];   /* 16 bit */
 
-    Does NOT contain payload! -> can be done manually
+    hdr.ipv4.checksum = ~tmp;
-    tmp = tmp + (bit<16>) hdr.ipv4.fragOffset;
-    tmp = tmp + (bit<16>) hdr.ipv4.ttl,
-    tmp = tmp + (bit<16>) hdr.ipv4.protocol,
-    tmp = tmp + (bit<16>) hdr.ipv4.src_addr,
-    tmp = tmp + (bit<16>) hdr.ipv4.dst_addr
-
-    */
-    hdr.ipv4.checksum = 0;    /* TO BE DONE! */
 }
 
 

p4src/actions_nat64_generic.p4

@@ -2,6 +2,7 @@
 #define NICO_NAT64_GENERIC
 
 #include "actions_controller.p4"
+#include "actions_delta_checksum.p4"
 
 /********************** NAT64 / NAT46 ACTIONS GENERIC ***********************************/
 
@@ -28,31 +29,32 @@ action nat64_icmp6_generic()
 action nat64_generic(ipv4_addr_t src, ipv4_addr_t dst) {
 	hdr.ipv4.setValid();
 
-    meta.chk_ipv4 = 1; /* need to calculate the hdrchecksum */
 
     /* Stuff that might need to be fixed */
     hdr.ipv4.version        = (bit<4>)4;
+    hdr.ipv4.ihl            = (bit<4>)5;                             // internet header length: 4*5 = 20
+                                                                     /* 5 is ok as long as
+                                                                       we don't use options / padding /
+                                                                       anything after the destination address */
     hdr.ipv4.diff_serv      = (bit<6>)0;                             // no ToS
 	hdr.ipv4.ecn            = (bit<2>)0;                             // unsupported
-
-    /* 5 is ok as long as we don't use options / padding /
-    anything after the destination address */
-    hdr.ipv4.ihl            = (bit<4>) 5;                            // internet header length: 4*5 = 20
     hdr.ipv4.totalLen       = (bit<16>) hdr.ipv6.payload_length + 20; // ok under above constraints
-
     hdr.ipv4.identification = (bit<16>) 0;                           // no support for fragments
     hdr.ipv4.flags          = (bit<3>)  0;                           // DF bit and more fragments
     hdr.ipv4.fragOffset     = (bit<13>) 0;                           // 0 as there are no fragments
+    hdr.ipv4.ttl            = hdr.ipv6.hop_limit;
+    hdr.ipv4.protocol       = hdr.ipv6.next_header;
+    hdr.ipv4.src_addr       = src;
+    hdr.ipv4.dst_addr       = dst;
 
     /* Stuff that should be fine */
 	hdr.ethernet.ethertype  = TYPE_IPV4;
 
-    hdr.ipv4.dst_addr       = dst;
+    #ifdef USE_NICO_DELTA_CHECKSUM
-    hdr.ipv4.src_addr       = src;
+    delta_ipv4_from_v6_to_v4();
-
+    #else
-    hdr.ipv4.ttl            = hdr.ipv6.hop_limit;
+    meta.chk_ipv4 = 1; /* need to calculate the hdrchecksum */
-
+    #endif
-    hdr.ipv4.protocol       = hdr.ipv6.next_header;
 
     hdr.ipv6.setInvalid();
 }