adde flowlet_switching exercise

SIGCOMM_2015/flowlet_switching/p4src/simple_router.p4

@@ -0,0 +1,132 @@
+/*
+Copyright 2013-present Barefoot Networks, Inc. 
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+#include "includes/headers.p4"
+#include "includes/parser.p4"
+#include "includes/intrinsic.p4"
+
+header_type ingress_metadata_t {
+    fields {
+        ecmp_offset : 14; // offset into the ecmp table
+
+        nhop_ipv4 : 32;
+
+        // TODO: add your flowlet metadata here
+    }
+}
+
+metadata ingress_metadata_t ingress_metadata;
+
+action _drop() {
+    drop();
+}
+
+action set_nhop(nhop_ipv4, port) {
+    modify_field(ingress_metadata.nhop_ipv4, nhop_ipv4);
+    modify_field(standard_metadata.egress_spec, port);
+    add_to_field(ipv4.ttl, -1);
+}
+
+#define ECMP_BIT_WIDTH 10
+#define ECMP_GROUP_TABLE_SIZE 1024
+#define ECMP_NHOP_TABLE_SIZE 16384
+
+// TODO: add flowlet id to hash fields
+
+field_list l3_hash_fields {
+    ipv4.srcAddr;
+    ipv4.dstAddr;
+    ipv4.protocol;
+    tcp.srcPort;
+    tcp.dstPort;
+}
+
+field_list_calculation ecmp_hash {
+    input {
+        l3_hash_fields;
+    }
+    algorithm : crc16;
+    output_width : ECMP_BIT_WIDTH;
+}
+
+
+action set_ecmp_select(ecmp_base, ecmp_count) {
+    modify_field_with_hash_based_offset(ingress_metadata.ecmp_offset, ecmp_base,
+                                        ecmp_hash, ecmp_count);
+}
+
+table ecmp_group {
+    reads {
+        ipv4.dstAddr : lpm;
+    }
+    actions {
+        _drop;
+        set_ecmp_select;
+    }
+    size : ECMP_GROUP_TABLE_SIZE;
+}
+
+table ecmp_nhop {
+    reads {
+        ingress_metadata.ecmp_offset : exact;
+    }
+    actions {
+        _drop;
+        set_nhop;
+    }
+    size : ECMP_NHOP_TABLE_SIZE;
+}
+
+action set_dmac(dmac) {
+    modify_field(ethernet.dstAddr, dmac);
+}
+
+table forward {
+    reads {
+        ingress_metadata.nhop_ipv4 : exact;
+    }
+    actions {
+        set_dmac;
+        _drop;
+    }
+    size: 512;
+}
+
+action rewrite_mac(smac) {
+    modify_field(ethernet.srcAddr, smac);
+}
+
+table send_frame {
+    reads {
+        standard_metadata.egress_port: exact;
+    }
+    actions {
+        rewrite_mac;
+        _drop;
+    }
+    size: 256;
+}
+
+control ingress {
+    // TODO: flowlet switching
+    apply(ecmp_group);
+    apply(ecmp_nhop);
+    apply(forward);
+}
+
+control egress {
+    apply(send_frame);
+}