Merge pull request #2119 from ecwolf/master

Added Hello World in P4
TheRenegadeCoder · Oct 4, 2020 · f34c81d · f34c81d
2 parents d314c53 + 2c3fdc5
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diff --git a/archive/p/p4/README.md b/archive/p/p4/README.md
@@ -0,0 +1,23 @@
+# Sample Programs in P4
+
+Welcome to Sample Programs in P4!
+
+## Sample Programs
+
+- [Hello World in P4][0]
+
+## Fun Facts
+
+- Debut: 2013
+- Developer: The P4 Language Consortium
+- License: Apache-style
+- Programming language for controlling packet forwarding planes in networking devices
+
+## References
+
+- [P4 Website][1]
+- [P4 GitHub][2]
+
+[0]: https://github.com/TheRenegadeCoder/sample-programs/issues/2117
+[1]: https://p4.org/code/
+[2]: https://github.com/p4lang/p4c
diff --git a/archive/p/p4/helloworld.p4 b/archive/p/p4/helloworld.p4
@@ -0,0 +1,201 @@
+/* -*- P4_16 -*- */
+
+
+
+/*************************************************************************
+
+    This is a P4 "Hello World" code:
+
+    When a packet arrives to the switch with some payload
+    data of 88 bites, the switch will forward the packet 
+    changing the payload to "Hello World".
+
+    The program is not intended to calculate a new checksum,
+    many errors can occur avoiding that process.
+
+    @ecwolf
+
+*************************************************************************/
+
+
+#include <core.p4>
+#include <v1model.p4>
+
+const bit<16> TYPE_IPV4 = 0x800;
+const bit<8> UDP_TYPE = 0x11;
+const bit<8> TCP_TYPE = 0x06;
+
+/*************************************************************************
+*********************** 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;
+}
+
+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;
+    ip4Addr_t srcAddr;
+    ip4Addr_t dstAddr;
+}
+
+header udp_t
+{
+    bit<16> srcPort;
+    bit<16> dstPort;
+    bit<16> len;
+    bit<16> checksum;
+    bit<88> payload;
+}
+
+struct metadata {
+    /* empty */
+}
+
+struct headers {
+    ethernet_t          ethernet;
+    ipv4_t              ipv4;
+    udp_t               udp;
+}
+
+/*************************************************************************
+*********************** 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) {
+            TYPE_IPV4: parse_ipv4;
+            default: accept;
+        }
+    }
+
+    state parse_ipv4 {
+        packet.extract(hdr.ipv4);
+        transition select(hdr.ipv4.protocol) {
+            UDP_TYPE : parse_udp;
+            default : accept;
+        }
+    }
+
+    state parse_udp {
+        packet.extract(hdr.udp);
+        transition 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 ipv4_forward(macAddr_t dstAddr, egressSpec_t port) {
+        standard_metadata.egress_spec = port;
+        hdr.ethernet.srcAddr = hdr.ethernet.dstAddr;
+        hdr.ethernet.dstAddr = dstAddr;
+        hdr.ipv4.ttl = hdr.ipv4.ttl - 1;
+        hdr.udp.payload = 0x48656C6C6F20576F726C64; // payload='Hello World'
+    }
+
+    table ipv4_lpm {
+        key = {
+            hdr.ipv4.dstAddr: lpm;
+        }
+        actions = {
+            ipv4_forward;
+            drop;
+            NoAction;
+        }
+        size = 1024;
+        default_action = drop();
+    }
+
+    apply {
+        ipv4_lpm.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) {
+    apply {}
+}
+
+/*************************************************************************
+*************   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);
+        packet.emit(hdr.ipv4);
+        packet.emit(hdr.udp);
+    }
+}
+
+/*************************************************************************
+***********************  S W I T C H  *******************************
+*************************************************************************/
+
+V1Switch(
+MyParser(),
+MyVerifyChecksum(),
+MyIngress(),
+MyEgress(),
+MyComputeChecksum(),
+MyDeparser()
+) main;