Exercise for L2 multicast (#288)

exercises/multicast/solution/multicast.p4

@@ -0,0 +1,149 @@
+/* -*- P4_16 -*- */
+#include <core.p4>
+#include <v1model.p4>
+
+/*************************************************************************
+*********************** H E A D E R S  ***********************************
+*************************************************************************/
+
+typedef bit<9>  egressSpec_t;
+typedef bit<48> macAddr_t;
+typedef bit<32> ip4Addr_t;
+
+
+header ethernet_t {
+    macAddr_t dstAddr;
+    macAddr_t srcAddr;
+    bit<16>   etherType;
+}
+
+
+struct metadata {
+    /* empty */
+}
+
+struct headers {
+    ethernet_t   ethernet;
+}
+
+/*************************************************************************
+*********************** P A R S E R  ***********************************
+*************************************************************************/
+
+parser MyParser(packet_in packet,
+                out headers hdr,
+                inout metadata meta,
+                inout standard_metadata_t standard_metadata) {
+
+    state start {
+        transition parse_ethernet;
+    }
+
+    state parse_ethernet {
+        packet.extract(hdr.ethernet);
+        transition select(hdr.ethernet.etherType) {
+            default : accept;
+        }
+    }
+}
+
+
+/*************************************************************************
+************   C H E C K S U M    V E R I F I C A T I O N   *************
+*************************************************************************/
+
+control MyVerifyChecksum(inout headers hdr, inout metadata meta) {
+    apply {  }
+}
+
+
+/*************************************************************************
+**************  I N G R E S S   P R O C E S S I N G   *******************
+*************************************************************************/
+
+control MyIngress(inout headers hdr,
+                  inout metadata meta,
+                  inout standard_metadata_t standard_metadata) {
+
+    action drop() {
+        mark_to_drop(standard_metadata);
+    }
+
+    action multicast() {
+        standard_metadata.mcast_grp = 1;
+    }
+
+    action mac_forward(egressSpec_t port) {
+        standard_metadata.egress_spec = port;
+    }
+
+    table mac_lookup {
+        key = {
+            hdr.ethernet.dstAddr : exact;
+        }
+        actions = {
+            multicast;
+            mac_forward;
+            drop;
+        }
+        size = 1024;
+        default_action = multicast;
+    }
+    apply {
+        if (hdr.ethernet.isValid())
+            mac_lookup.apply();
+    }
+}
+
+/*************************************************************************
+****************  E G R E S S   P R O C E S S I N G   *******************
+*************************************************************************/
+
+control MyEgress(inout headers hdr,
+                 inout metadata meta,
+                 inout standard_metadata_t standard_metadata) {
+
+    action drop() {
+        mark_to_drop(standard_metadata);
+    }
+
+    apply {
+        // Prune multicast packet to ingress port to preventing loop
+        if (standard_metadata.egress_port == standard_metadata.ingress_port)
+            drop();
+    }
+}
+
+/*************************************************************************
+*************   C H E C K S U M    C O M P U T A T I O N   **************
+*************************************************************************/
+
+control MyComputeChecksum(inout headers hdr, inout metadata meta) {
+     apply {
+
+    }
+}
+
+
+/*************************************************************************
+***********************  D E P A R S E R  *******************************
+*************************************************************************/
+
+control MyDeparser(packet_out packet, in headers hdr) {
+    apply {
+        packet.emit(hdr.ethernet);
+    }
+}
+
+/*************************************************************************
+***********************  S W I T C H  *******************************
+*************************************************************************/
+
+V1Switch(
+MyParser(),
+MyVerifyChecksum(),
+MyIngress(),
+MyEgress(),
+MyComputeChecksum(),
+MyDeparser()
+) main;

exercises/multicast/solution/s1-runtime.json

@@ -0,0 +1,70 @@
+{
+  "target": "bmv2",
+  "p4info": "build/multicast.p4.p4info.txt",
+  "bmv2_json": "build/multicast.json",
+  "table_entries": [
+    {
+      "table": "MyIngress.mac_lookup",
+      "match": {
+        "hdr.ethernet.dstAddr": "08:00:00:00:01:11"
+      },
+      "action_name": "MyIngress.mac_forward",
+      "action_params": {
+        "port": 1
+      }
+    },
+    {
+      "table": "MyIngress.mac_lookup",
+      "match": {
+        "hdr.ethernet.dstAddr": "08:00:00:00:02:22"
+      },
+      "action_name": "MyIngress.mac_forward",
+      "action_params": {
+        "port": 2
+      }
+    },
+    {
+      "table": "MyIngress.mac_lookup",
+      "match": {
+        "hdr.ethernet.dstAddr": "08:00:00:00:03:33"
+      },
+      "action_name": "MyIngress.mac_forward",
+      "action_params": {
+        "port": 3
+      }
+    },
+    {
+      "table": "MyIngress.mac_lookup",
+      "match": {
+        "hdr.ethernet.dstAddr": "08:00:00:00:04:44"
+      },
+      "action_name": "MyIngress.mac_forward",
+      "action_params": {
+        "port": 4
+      }
+    }
+  ],
+  "multicast_group_entries" : [
+    {
+      "multicast_group_id" : 1,
+      "replicas" : [
+        {
+          "egress_port" : 1,
+          "instance" : 1
+        },
+        {
+          "egress_port" : 2,
+          "instance" : 1
+        },
+        {
+          "egress_port" : 3,
+          "instance" : 1
+        },
+        {
+          "egress_port" : 4,
+          "instance" : 1
+        }
+      ]
+    }
+  ]
+}