RSSHashSwitch: Switch element using the RSS software hash

elements/userlevel/rsshashswitch.cc

@@ -0,0 +1,118 @@
+/*
+ * RSSHashSwitch.{cc,hh} -- element demultiplexes packets based on hash of
+ * specified packet fields
+ * Eddie Kohler
+ *
+ * Computational batching support by Georgios Katsikas
+ *
+ * Copyright (c) 1999-2000 Massachusetts Institute of Technology
+ * Copyright (c) 2018 Georgios Katsikas, RISE SICS
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, subject to the conditions
+ * listed in the Click LICENSE file. These conditions include: you must
+ * preserve this copyright notice, and you cannot mention the copyright
+ * holders in advertising related to the Software without their permission.
+ * The Software is provided WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED. This
+ * notice is a summary of the Click LICENSE file; the license in that file is
+ * legally binding.
+ */
+
+#include <click/config.h>
+#include "rsshashswitch.hh"
+#include <click/error.hh>
+#include <click/args.hh>
+#include <clicknet/ether.h>
+
+#include <click/dpdkdevice.hh>
+#include <click/ip6address.hh>
+#include <click/ip6flowid.hh>
+#include <rte_thash.h>
+
+CLICK_DECLS
+
+RSSHashSwitch::RSSHashSwitch()
+{
+}
+
+#define RSS_HASH_KEY_LENGTH 40
+static uint8_t hash_key[RSS_HASH_KEY_LENGTH] = {
+0x6D, 0x5A, 0x6D, 0x5A, 0x6D, 0x5A, 0x6D, 0x5A,
+0x6D, 0x5A, 0x6D, 0x5A, 0x6D, 0x5A, 0x6D, 0x5A,
+0x6D, 0x5A, 0x6D, 0x5A, 0x6D, 0x5A, 0x6D, 0x5A,
+0x6D, 0x5A, 0x6D, 0x5A, 0x6D, 0x5A, 0x6D, 0x5A,
+0x6D, 0x5A, 0x6D, 0x5A, 0x6D, 0x5A, 0x6D, 0x5A,
+};
+
+int
+RSSHashSwitch::configure(Vector<String> &conf, ErrorHandler *errh)
+{
+    _max = noutputs();
+    if (Args(conf, this, errh)
+        .read("MAX", _max)
+        .complete() < 0)
+    return -1;
+
+
+    return 0;
+}
+
+int
+RSSHashSwitch::process(Packet *p)
+{
+    union rte_thash_tuple tuple = {0};
+
+    /* A complete tuple from the packet. */
+    struct click_ether *eth = (click_ether*) p->mac_header();
+
+    int len = 0;
+    if (eth->ether_type == 0x0008) {
+
+        IPFlowID f(p);
+        tuple.v4.sport = f.sport();
+
+        tuple.v4.dport = f.dport();
+        IPAddress a = f.saddr();
+        memcpy(&tuple.v4.src_addr, &a, 4);
+        a = f.daddr();
+        memcpy(&tuple.v4.dst_addr, &a, 4);
+        len = 4 + 4 + 2 + 2;
+
+    } else if  (eth->ether_type == 0xDD86) {
+        IP6FlowID f(p);
+        tuple.v6.sport = f.sport();
+        tuple.v6.dport = f.dport();
+        IP6Address a = f.saddr();
+        memcpy(&tuple.v6.src_addr, &a, 16);
+        a = f.daddr();
+        memcpy(&tuple.v6.dst_addr, &a, 16);
+        len = 16 + 16 + 2 + 2;
+    } else {
+        return 0;
+    }
+
+    uint32_t orig_hash = rte_softrss((uint32_t *)&tuple, len, hash_key);
+
+    return orig_hash % _max;
+}
+
+void
+RSSHashSwitch::push(int port, Packet *p)
+{
+    output(process(p)).push(p);
+}
+
+#if HAVE_BATCH
+void
+RSSHashSwitch::push_batch(int port, PacketBatch *batch)
+{
+    auto fnt = [this, port](Packet *p) { return process(p); };
+    CLASSIFY_EACH_PACKET(_max + 1, fnt, batch, checked_output_push_batch);
+}
+#endif
+
+CLICK_ENDDECLS
+EXPORT_ELEMENT(RSSHashSwitch)
+ELEMENT_MT_SAFE(RSSHashSwitch)
+ELEMENT_REQUIRES(dpdk)

elements/userlevel/rsshashswitch.hh

@@ -0,0 +1,49 @@
+#ifndef CLICK_RSSHashSwitch_HH
+#define CLICK_RSSHashSwitch_HH
+#include <click/batchelement.hh>
+CLICK_DECLS
+
+/*
+ * =c
+ * RSSHashSwitch(OFFSET, LENGTH)
+ * =s classification
+ * classifies packets by hash of contents
+ * =d
+ * Can have any number of outputs.
+ * Chooses the output on which to emit each packet based on
+ * a hash of the LENGTH bytes starting at OFFSET.
+ * Could be used for stochastic fair queuing.
+ * =e
+ * This element expects IP packets and chooses the output
+ * based on a hash of the IP destination address:
+ *
+ *   RSSHashSwitch(16, 4)
+ * =a
+ * Switch, RoundRobinSwitch, StrideSwitch, RandomSwitch
+ */
+
+class RSSHashSwitch : public BatchElement {
+
+    int _max;
+
+ public:
+
+    RSSHashSwitch() CLICK_COLD;
+
+    const char *class_name() const override        { return "RSSHashSwitch"; }
+    const char *port_count() const override        { return "1/1-"; }
+    const char *processing() const override        { return PUSH; }
+
+    int configure(Vector<String> &, ErrorHandler *) CLICK_COLD;
+
+    int process(Packet *);
+    void push(int port, Packet *);
+#if HAVE_BATCH
+    void push_batch(int port, PacketBatch *);
+#endif
+
+};
+
+CLICK_ENDDECLS
+
+#endif

lib/ip6flowid.cc

@@ -40,7 +40,6 @@ IP6FlowID::IP6FlowID(const Packet *p, bool reverse)
       assign(IP6Address(ip6h->ip6_dst), udph->uh_dport, IP6Address(ip6h->ip6_src), udph->uh_sport);
     }
   } else {
-    assert(IP_FIRSTFRAG(iph));
     if (likely(!reverse))
       assign(iph->ip_src, udph->uh_sport,
              iph->ip_dst, udph->uh_dport);