Add basic BIER elements

DISTFILES

@@ -388,6 +388,7 @@ archive.hh
 args.hh
 array_memory.hh
 atomic.hh
+biertable.hh
 bighashmap.cc
 bighashmap.hh
 bighashmap_arena.hh
@@ -474,6 +475,7 @@ storage.hh
 threadsched.hh
 
 ./include/clicknet:
+bier.h
 dhcp.h
 ether.h
 fddi.h
@@ -493,6 +495,7 @@ wifi.h
 archive.cc
 args.cc
 atomic.cc
+biertable.cc
 bighashmap_arena.cc
 bitvector.cc
 clp.c

configure.in

@@ -679,6 +679,7 @@ fi])
 ELEMENTS_ARG_ENABLE(analysis, [include elements for network analysis], yes)
 ELEMENTS_ARG_ENABLE(app, [include application-level elements], yes)
 ELEMENTS_ARG_ENABLE(aqm, [include active queue management elements], yes)
+ELEMENTS_ARG_ENABLE(bier, [include BIER elements], NO)
 ELEMENTS_ARG_ENABLE(ethernet, [include Ethernet elements], yes)
 ELEMENTS_ARG_ENABLE(etherswitch, [include Ethernet switch elements], NO)
 ELEMENTS_ARG_ENABLE(flow, [include Enable flow system and elements], NO, enable_flow=yes, [ -a "x$enable_batch" = xyes ] )
@@ -1082,6 +1083,11 @@ if test "x$enable_ip6" = xyes; then
     EXTRA_DRIVER_OBJS="ip6address.o ip6flowid.o ip6table.o $EXTRA_DRIVER_OBJS"
     EXTRA_TOOL_OBJS="ip6address.o $EXTRA_TOOL_OBJS"
 fi
+
+if test "x$enable_bier" = xyes; then
+    EXTRA_DRIVER_OBJS="biertable.o $EXTRA_DRIVER_OBJS"
+fi
+
 AC_SUBST(EXTRA_DRIVER_OBJS)
 AC_SUBST(EXTRA_TOOL_OBJS)
 

elements/bier/bierroutetable.cc

@@ -0,0 +1,106 @@
+/*
+ * bierroutetable.{cc,hh} -- implement handlers for BIFT element
+ * Nicolas Rybowski
+ *
+ * Copyright (c) 2024 UCLouvain
+ *
+ * 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 "bierroutetable.hh"
+#include <click/args.hh>
+#include <click/error.hh>
+#include <click/glue.hh>
+#include <click/ip6address.hh>
+#include <click/ipaddress.hh>
+CLICK_DECLS
+
+void* BierRouteTable::cast(const char *name) {
+  if (strcmp(name, "BierRouteTable") == 0)
+    return (void*) this;
+  else
+    return Element::cast(name);
+}
+
+int BierRouteTable::add_route(bfrid, IP6Address, bitstring, IP6Address, int, String, ErrorHandler *errh) {
+  return errh->error("cannot add routes to this routing table");
+}
+
+int BierRouteTable::del_route(bfrid, ErrorHandler *errh) {
+  return errh->error("cannot del routes to this routing table");
+}
+
+String BierRouteTable::dump_routes() {
+  return String();
+}
+
+int BierRouteTable::add_route_handler(const String &conf, Element *e, void *, ErrorHandler *errh) {
+  BierRouteTable *r = static_cast<BierRouteTable *>(e);
+  Vector<String> words;
+  cp_spacevec(conf, words);
+
+  bitstring fbm;
+  IP6Address nxt;
+  int output;
+  String ifname;
+  String raw_bfrs;
+
+  if (
+    Args(words, r, errh)
+       .read_mp("BITSTRING", fbm)
+       .read_mp("NXT", nxt)
+       .read_mp("IFIDX", output)
+       .read_mp("IFNAME", ifname)
+       .read_mp("BFR", raw_bfrs)
+       .complete() < 0
+  )
+    return -1;
+
+  Vector<String> bfrs;
+  cp_argvec(raw_bfrs, bfrs);
+
+  for (int i=0; i<bfrs.size(); i++) {
+    Vector<String> bfr = bfrs[i].split('_');
+    if (bfr.size() != 2) {
+      click_chatter("Invalid BFR specification. Should be \"BFR <bfr-id>_<bfr-prefix>\"");
+      continue;
+    }
+    if (r->add_route((bfrid) atoi(bfr[0].c_str()), IP6Address(bfr[1]), fbm, nxt, output, ifname, errh)) {
+      click_chatter("Failed to add BIFT entry. Ignoring.");
+      continue;
+    }
+  }
+
+  return 0;
+}
+
+String BierRouteTable::table_handler(Element *e, void *) {
+  BierRouteTable *r = static_cast<BierRouteTable *>(e);
+  return r->dump_routes();
+}
+
+int BierRouteTable::del_route_handler(const String &conf, Element *e, void *, ErrorHandler *errh) {
+  BierRouteTable *r = static_cast<BierRouteTable *>(e);
+  Vector<String> words;
+  cp_spacevec(conf, words);
+
+  bfrid bfrid;
+
+  if (Args(words, r, errh).read_mp("BFR-ID", bfrid).complete() < 0)
+    return -1;
+
+  return r->del_route(bfrid, errh);
+
+}
+
+CLICK_ENDDECLS
+ELEMENT_PROVIDES(BierRouteTable)

elements/bier/bierroutetable.hh

@@ -0,0 +1,27 @@
+#ifndef CLICK_BIERROUTETABLE_HH
+#define CLICK_BIERROUTETABLE_HH
+#include <click/glue.hh>
+#include <click/batchelement.hh>
+#include <click/ip6address.hh>
+#include <clicknet/bier.h>
+CLICK_DECLS
+
+class BierRouteTable : public BatchElement {
+  public:
+    void* cast(const char*) override;
+    const char *port_count() const override { return PORTS_0_0; }
+
+    virtual int add_route(bfrid, IP6Address, bitstring, IP6Address, int, String, ErrorHandler*);
+    virtual int del_route(bfrid, ErrorHandler*);
+    virtual String dump_routes();
+
+    static int add_route_handler(const String&, Element*, void*, ErrorHandler*);
+    static int del_route_handler(const String&, Element*, void*, ErrorHandler*);
+    static String table_handler(Element*, void*);
+
+  private:
+    uint16_t _bfr_id;
+};
+
+CLICK_ENDDECLS
+#endif

elements/bier/checkbierheader.cc

@@ -0,0 +1,100 @@
+/*
+ * checkbierheader.{cc,hh} -- checks BIER header for correctness
+ * Nicolas Rybowski
+ *
+ * Copyright (c) 2024 UCLouvain
+ *
+ * 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 "checkbierheader.hh"
+#include <click/element.hh>
+#include <clicknet/ip6.h>
+#include <click/packet.hh>
+#include <clicknet/bier.h>
+#include <click/args.hh>
+#include <click/error.hh>
+#include <click/standard/alignmentinfo.hh>
+
+CLICK_DECLS
+
+CheckBIERHeader::CheckBIERHeader() : _offset(0) {
+  _drops = 0;
+}
+
+CheckBIERHeader::~CheckBIERHeader() {}
+
+int CheckBIERHeader::configure(Vector<String> &conf,ErrorHandler *errh) {
+  if (Args(conf, this, errh)
+      .read_p("OFFSET", _offset)
+      .complete() < 0
+  )
+    return -1;
+  return 0;
+}
+
+void CheckBIERHeader::drop(Packet *p) {
+  if (_drops == 0) {
+    click_chatter("BIER header check failed");
+  }
+  _drops++;
+
+  if (noutputs() == 2) {
+    output(1).push(p);
+  } else {
+    p->kill();
+  }
+
+}
+
+Packet *CheckBIERHeader::simple_action(Packet *p) {
+  const click_bier *bier;
+  unsigned plen;
+
+  bier = reinterpret_cast<const click_bier*>(p->data());
+  plen = p->length();
+
+  if((int)plen < (int)sizeof(click_bier)) {
+    click_chatter("BIERin6 header too small");
+    goto drop;
+  }
+
+  // TODO: check that BSL is different from 0
+
+  // TODO: check that BS is not NULL
+
+  return(p);
+
+  drop:
+    drop(p);
+    return 0;
+}
+
+String CheckBIERHeader::read_handler(Element *e, void *thunk) {
+  CheckBIERHeader *c = reinterpret_cast<CheckBIERHeader *>(e);
+  switch (reinterpret_cast<uintptr_t>(thunk)) {
+    case h_drops: {
+        return String(c->_drops);
+    }
+    defaut: {
+      return String();
+    }
+  }
+}
+
+void CheckBIERHeader::add_handlers() {
+  add_read_handler("drops", read_handler, h_drops);
+}
+
+CLICK_ENDDECLS
+EXPORT_ELEMENT(CheckBIERHeader)
+ELEMENT_MT_SAFE(CheckBIERHeader)

elements/bier/checkbierheader.hh

@@ -0,0 +1,58 @@
+#ifndef CLICK_CHECKBIERHEADER_HH
+#define CLICK_CHECKBIERHEADER_HH
+#include <click/batchelement.hh>
+#include <click/confparse.hh>
+#include <clicknet/bier.h>
+CLICK_DECLS
+
+/*
+ * =c
+ * CheckBIERHeader([OFFSET])
+ * =s bier
+ *
+ * =d
+ * 
+ * Expects BIER packets as input starting at OFFSET bytes. Default OFFSET is zero.
+ * Checks that thet packet's length is reasonable.
+ * Pushes invalid or non BIER packets out on output 1, unless output 1 was unused; if so,
+ * drop the packets.
+ *
+ * Keyword arguments are:
+ *
+ * =over 8
+ *
+ * =item OFFSET
+ *
+ * Unsigned integer. Byte position at which the BIER header begins. Default is 0.
+ *
+ * =back
+ *
+ */
+
+class CheckBIERHeader : public SimpleElement<CheckBIERHeader> {
+  public:
+     CheckBIERHeader();
+     ~CheckBIERHeader();
+
+     const char *class_name() const override { return "CheckBIERHeader"; }
+     const char *port_count() const override { return PORTS_1_1X2; }
+     const char *processing() const override { return PROCESSING_A_AH; }
+
+     int configure(Vector<String> &, ErrorHandler *) CLICK_COLD;
+     void add_handlers() CLICK_COLD;
+
+     Packet *simple_action(Packet *p);
+
+  private:
+    int _offset;
+    atomic_uint64_t _drops;
+
+    enum {h_drops};
+
+    void drop(Packet *p);
+    static String read_handler(Element *e, void *thunk) CLICK_COLD;
+
+};
+
+CLICK_ENDDECLS
+#endif