Add simple_l3_varbits example

Add example that's based on the simple_l3 example
(https://github.com/p4tc-dev/p4tc-examples-pub/blob/main/simple/simple_l3/simple_l3.p4),
and parser IPv4 options

testdata/p4tc_samples/simple_l3_varbits.p4

@@ -0,0 +1,159 @@
+/* -*- P4_16 -*- */
+
+#include <core.p4>
+#include <tc/pna.p4>
+
+struct my_ingress_metadata_t {
+}
+
+struct empty_metadata_t {
+}
+
+/*
+ * CONST VALUES FOR TYPES
+ */
+const bit<8> IP_PROTO_TCP = 0x06;
+const bit<16> ETHERTYPE_IPV4 = 0x0800;
+
+/*
+ * Standard ethernet header
+ */
+header ethernet_t {
+    bit<48> dstAddr;
+    bit<48> srcAddr;
+    bit<16> etherType;
+}
+
+header ipv4_t {
+    bit<4>  version;
+    bit<4>  ihl;
+    bit<8>  diffserv;
+    bit<16> totalLen;
+    bit<16> identification;
+    bit<3>  flags;
+    bit<13> fragOffset;
+    bit<8>  ttl;
+    bit<8>  protocol;
+    bit<16> hdrChecksum;
+    bit<32> srcAddr;
+    bit<32> dstAddr;
+}
+
+header v4_options_t {
+    varbit<320> opts;
+}
+
+struct my_ingress_headers_t {
+    ethernet_t   ethernet;
+    ipv4_t       ipv4;
+    v4_options_t opts;
+}
+
+    /***********************  P A R S E R  **************************/
+parser Ingress_Parser(
+        packet_in pkt,
+        out   my_ingress_headers_t  hdr,
+        inout my_ingress_metadata_t meta,
+        in    pna_main_parser_input_metadata_t istd)
+{
+
+    state start {
+        transition parse_ethernet;
+    }
+
+    state parse_ethernet {
+        pkt.extract(hdr.ethernet);
+        transition select(hdr.ethernet.etherType) {
+            ETHERTYPE_IPV4: parse_ipv4;
+            default: reject;
+        }
+    }
+    state parse_ipv4 {
+        pkt.extract(hdr.ipv4);
+	transition select(hdr.ipv4.ihl) {
+	    4w0: reject;
+	    4w1: reject;
+	    4w2: reject;
+	    4w3: reject;
+	    4w4: reject;
+	    5: parse_proto;
+	    default: parse_v4_opts;
+	}
+    }
+    state parse_v4_opts {
+	// XXX The cast to bit<32> is because pkt.extract demands
+	//  bit<32> for its second arg
+	pkt.extract(hdr.opts,(bit<32>)(32*(bit<9>)(hdr.ipv4.ihl-5)));
+	transition parse_proto;
+    }
+    state parse_proto {
+        transition select(hdr.ipv4.protocol) {
+            IP_PROTO_TCP : accept;
+            default: reject;
+        }
+    }
+}
+
+#define L3_TABLE_SIZE 2048
+
+/***************** M A T C H - A C T I O N  *********************/
+
+control ingress(
+    inout my_ingress_headers_t  hdr,
+    inout my_ingress_metadata_t meta,
+    in    pna_main_input_metadata_t  istd,
+    inout pna_main_output_metadata_t ostd
+)
+{
+   action send_nh(@tc_type("dev") PortId_t port, @tc_type("macaddr") bit<48> srcMac, @tc_type("macaddr") bit<48> dstMac) {
+        hdr.ethernet.srcAddr = srcMac;
+        hdr.ethernet.dstAddr = dstMac;
+        hdr.ipv4.ttl = 31;
+        send_to_port(port);
+   }
+
+   action drop() {
+        drop_packet();
+   }
+
+    table nh_table {
+        key = {
+            hdr.ipv4.dstAddr : exact @tc_type("ipv4") @name("dstAddr");
+        }
+        actions = {
+            send_nh;
+            drop;
+        }
+        size = L3_TABLE_SIZE;
+        const default_action = drop;
+    }
+
+    apply {
+        if (hdr.ipv4.isValid() && hdr.ipv4.protocol == IP_PROTO_TCP) {
+            nh_table.apply();
+        }
+    }
+}
+
+    /*********************  D E P A R S E R  ************************/
+
+control Ingress_Deparser(
+    packet_out pkt,
+    inout    my_ingress_headers_t hdr,
+    in    my_ingress_metadata_t meta,
+    in    pna_main_output_metadata_t ostd)
+{
+    apply {
+        pkt.emit(hdr.ethernet);
+        pkt.emit(hdr.ipv4);
+        pkt.emit(hdr.opts);
+    }
+}
+
+/************ F I N A L   P A C K A G E ******************************/
+
+PNA_NIC(
+    Ingress_Parser(),
+    ingress(),
+    Ingress_Deparser()
+) main;

testdata/p4tc_samples_outputs/simple_l3_varbits.json

@@ -0,0 +1,63 @@
+{
+  "schema_version" : "1.0.0",
+  "pipeline_name" : "simple_l3_varbits",
+  "externs" : [],
+  "tables" : [
+    {
+      "name" : "ingress/nh_table",
+      "id" : 1,
+      "tentries" : 2048,
+      "permissions" : "0x3da4",
+      "nummask" : 8,
+      "keysize" : 32,
+      "keyfields" : [
+        {
+          "id" : 1,
+          "name" : "dstAddr",
+          "type" : "ipv4",
+          "match_type" : "exact",
+          "bitwidth" : 32
+        }
+      ],
+      "actions" : [
+        {
+          "id" : 1,
+          "name" : "ingress/send_nh",
+          "action_scope" : "TableAndDefault",
+          "annotations" : [],
+          "params" : [
+            {
+              "id" : 1,
+              "name" : "port",
+              "type" : "dev",
+              "bitwidth" : 32
+            },
+            {
+              "id" : 2,
+              "name" : "srcMac",
+              "type" : "macaddr",
+              "bitwidth" : 48
+            },
+            {
+              "id" : 3,
+              "name" : "dstMac",
+              "type" : "macaddr",
+              "bitwidth" : 48
+            }
+          ],
+          "default_hit_action" : false,
+          "default_miss_action" : false
+        },
+        {
+          "id" : 2,
+          "name" : "ingress/drop",
+          "action_scope" : "TableAndDefault",
+          "annotations" : [],
+          "params" : [],
+          "default_hit_action" : false,
+          "default_miss_action" : true
+        }
+      ]
+    }
+  ]
+}

testdata/p4tc_samples_outputs/simple_l3_varbits.template

@@ -0,0 +1,24 @@
+#!/bin/bash -x
+
+set -e
+
+TC="tc"
+$TC p4template create pipeline/simple_l3_varbits numtables 1
+
+$TC p4template create action/simple_l3_varbits/ingress/send_nh actid 1 \
+	param port type dev \
+	param srcMac type macaddr \
+	param dstMac type macaddr
+$TC p4template update action/simple_l3_varbits/ingress/send_nh state active
+
+$TC p4template create action/simple_l3_varbits/ingress/drop actid 2
+$TC p4template update action/simple_l3_varbits/ingress/drop state active
+
+$TC p4template create table/simple_l3_varbits/ingress/nh_table \
+	tblid 1 \
+	type exact \
+	keysz 32 nummasks 8 permissions 0x3da4 tentries 2048 \
+	table_acts act name simple_l3_varbits/ingress/send_nh \
+	act name simple_l3_varbits/ingress/drop
+$TC p4template update table/simple_l3_varbits/ingress/nh_table default_miss_action permissions 0x1024 action simple_l3_varbits/ingress/drop
+$TC p4template update pipeline/simple_l3_varbits state ready