bier: Add BFR prefix to BIFT

tbarbette · Oct 31, 2024 · f57049c · f57049c
1 parent b505da5
commit f57049c
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Showing 7 changed files with 37 additions and 22 deletions.
diff --git a/elements/bier/bierroutetable.cc b/elements/bier/bierroutetable.cc
@@ -21,6 +21,7 @@
 #include <click/error.hh>
 #include <click/glue.hh>
 #include <click/ip6address.hh>
+#include <click/ipaddress.hh>
 CLICK_DECLS
 
 void* BierRouteTable::cast(const char *name) {
@@ -30,7 +31,7 @@ void* BierRouteTable::cast(const char *name) {
     return Element::cast(name);
 }
 
-int BierRouteTable::add_route(bfrid, bitstring, IP6Address, int, String, ErrorHandler *errh) {
+int BierRouteTable::add_route(bfrid, IP6Address, bitstring, IP6Address, int, String, ErrorHandler *errh) {
   return errh->error("cannot add routes to this routing table");
 }
 
@@ -44,6 +45,7 @@ int BierRouteTable::add_route_handler(const String &conf, Element *e, void *, Er
   cp_spacevec(conf, words);
 
   bfrid dst;
+  IP6Address bfr_prefix;
   bitstring fbm;
   IP6Address nxt;
   int output;
@@ -54,14 +56,15 @@ int BierRouteTable::add_route_handler(const String &conf, Element *e, void *, Er
   // TODO: read_all for BFRID and define dst as an array for route addition batching
   ok = Args(words, r, errh)
        .read_mp("BFRID", dst)
+       .read_mp("BFRPREFIX", bfr_prefix)
        .read_mp("BITSTRING", fbm)
        .read_mp("NXT", nxt)
        .read_mp("IFIDX", output)
        .read_mp("IFNAME", ifname)
        .complete();
 
   if (ok >= 0)
-    ok = r->add_route(dst, fbm, nxt, output, ifname, errh);
+    ok = r->add_route(dst, bfr_prefix, fbm, nxt, output, ifname, errh);
 
   return ok;
 }

diff --git a/elements/bier/bierroutetable.hh b/elements/bier/bierroutetable.hh
@@ -11,7 +11,7 @@ class BierRouteTable : public BatchElement {
     void* cast(const char*) override;
     const char *port_count() const override { return PORTS_0_0; }
 
-    virtual int add_route(bfrid, bitstring, IP6Address, int, String, ErrorHandler*);
+    virtual int add_route(bfrid, IP6Address, bitstring, IP6Address, int, String, ErrorHandler*);
     virtual String dump_routes();
 
     static int add_route_handler(const String&, Element*, void*, ErrorHandler*);

diff --git a/elements/bier/lookupbiertable.cc b/elements/bier/lookupbiertable.cc
@@ -18,6 +18,7 @@
 #include <click/config.h>
 #include <click/args.hh>
 #include <click/glue.hh>
+#include <click/ip6address.hh>
 #include <click/packet.hh>
 #include <click/straccum.hh>
 #include <clicknet/bier.h>
@@ -72,7 +73,7 @@ int LookupBierTable::classify(Packet *p_in) {
 
   unsigned short k = 0;
   uint16_t bift_id;
-  IP6Address nxt;
+  IP6Address nxt, bfr_prefix;
   bitstring fbm;
   bfrid bfr_id;
   int index;
@@ -106,7 +107,10 @@ int LookupBierTable::classify(Packet *p_in) {
   );
 
   // Sanity check: the BIFT ID specified in the BIER packet corresponds to the current BIFT. 
-  if (bier->bier_bift_id != _bift_id) return -1;
+  if (bier->bier_bift_id != _bift_id) {
+    click_chatter("Unknown BIFT-ID %x. Ignoring.", bier->bier_bift_id);
+    return -1;
+  }
 
   // RFC8279 Section 6.5 Step 2
   while (bs != 0) {
@@ -134,20 +138,20 @@ int LookupBierTable::classify(Packet *p_in) {
     // the BIER packet's BIFT ID already has been verified earlier.
 
     // RFC8279 Section 6.5 Step 6
-    if (_t.lookup(bfr_id, fbm, nxt, index, ifname)) {
+    if (_t.lookup(bfr_id, bfr_prefix, fbm, nxt, index, ifname)) {
       fbm.resize(bsl);
 
       // RFC8279 Section 6.5 Step 7
       WritablePacket *p2 = p->duplicate();
+      SET_DST_IP6_ANNO(p2, nxt);
       click_ip6 *ip6 = reinterpret_cast<click_ip6*>(p2->data());
-      ip6->ip6_dst = nxt;
-      click_bier *bier_dup = reinterpret_cast<click_bier*>(p2->data()+sizeof(click_ip6));
-      memcpy(bier_dup->bitstring, (bs & fbm).data_words(), bsl/(sizeof(Bitvector::word_type)*8));
-      bier_dup->encode();
-      // TODO: Add ethernet header to the packet
+      ip6->ip6_dst = bfr_prefix;
+      click_bier *bier = reinterpret_cast<click_bier*>(p2->data()+sizeof(click_ip6));
+      memcpy(bier->bitstring, (bs & fbm).data_words(), bsl/(sizeof(Bitvector::word_type)*8));
+      bier->encode();
 
       // ifname is ensured to be in _ifaces because of the check upon route addition.
-      output(_ifaces[ifname]).push(p2->duplicate());
+      output(_ifaces[ifname]).push(p2);
 
       // RFC8279 Section 6.5 Step 8
       bs &= ~fbm;
@@ -165,11 +169,11 @@ int LookupBierTable::classify(Packet *p_in) {
     return -1;
 }
 
-int LookupBierTable::add_route(bfrid dst, bitstring fbm, IP6Address nxt, int output, String ifname, ErrorHandler *errh) {
+int LookupBierTable::add_route(bfrid dst, IP6Address bfr_prefix, bitstring fbm, IP6Address nxt, int output, String ifname, ErrorHandler *errh) {
   // if (output < 0 || output >= noutputs())
     // return errh->error("port number <%u> out of range", output);
   // TODO: Check if ifname is in table
-  _t.add(dst, fbm, nxt, output, ifname);
+  _t.add(dst, bfr_prefix, fbm, nxt, output, ifname);
   return 0;
 }
 

diff --git a/elements/bier/lookupbiertable.hh b/elements/bier/lookupbiertable.hh
@@ -21,7 +21,7 @@ class LookupBierTable : public ClassifyElement<LookupBierTable, BierRouteTable>
     int configure(Vector<String> &, ErrorHandler *) CLICK_COLD;
 		void add_handlers() override CLICK_COLD;
 
-		int add_route(bfrid dst, bitstring fbm, IP6Address nxt, int, String, ErrorHandler*);
+		int add_route(bfrid dst, IP6Address bfr_prefix, bitstring fbm, IP6Address nxt, int, String, ErrorHandler*);
 		String dump_routes() { return _t.dump(); }
 
 	private:

diff --git a/include/click/biertable.hh b/include/click/biertable.hh
@@ -12,16 +12,17 @@ class BierTable {
     BierTable();
     ~BierTable();
 
-    bool lookup(const bfrid &dst, bitstring &fbm, IP6Address &nxt, int &index, String &ifname) const;
+    bool lookup(const bfrid &dst, IP6Address &bfr_prefix, bitstring &fbm, IP6Address &nxt, int &index, String &ifname) const;
 
     void del(const bfrid &dst);
-    void add(const bfrid &dst, const bitstring fbm, const IP6Address &nxt, int output, String ifname);
+    void add(const bfrid &dst, const IP6Address bfr_prefix, const bitstring fbm, const IP6Address &nxt, int output, String ifname);
     void clear() { _v.clear(); }
     String dump();
 
   private:
     struct Entry {
       bfrid _dst;
+      IP6Address _bfr_prefix;
       bitstring _fbm;
       IP6Address _nxt;
       int _if_idx;

diff --git a/include/clicknet/bier.h b/include/clicknet/bier.h
@@ -96,18 +96,22 @@ struct click_bier {
     bier_un.bier_un1.bier_un1_l3  = htonl(bier_un.bier_un1.bier_un1_l3);
     // FIXME: Do not use BSL per RFC8296. BSL should be provided as an argument.
     size_t bsl = _click_bier_expand_bsl(bier_bsl) / 32;
-    click_chatter("bsl %u %u", bier_bsl, bsl);
-    uint32_t _bitstring[bsl] = {0};
+    uint32_t _bitstring[bsl];
     for (size_t i=0; i<bsl; i++) _bitstring[bsl-1-i] = htonl(bitstring[i]);
     memcpy(bitstring, _bitstring, bsl*sizeof(uint32_t));
 #endif
   }
 
   void encode() {
 #if CLICK_BYTE_ORDER == CLICK_LITTLE_ENDIAN
+    // FIXME: Do not use BSL per RFC8296. BSL should be provided as an argument.
+    size_t bsl = _click_bier_expand_bsl(bier_bsl) / 32;
     bier_un.bier_un1.bier_un1_l1  = ntohl(bier_un.bier_un1.bier_un1_l1); 
     bier_un.bier_un1.bier_un1_l2  = ntohl(bier_un.bier_un1.bier_un1_l2); 
     bier_un.bier_un1.bier_un1_l3  = ntohl(bier_un.bier_un1.bier_un1_l3); 
+    uint32_t _bitstring[bsl];
+    for (size_t i=0; i<bsl; i++) _bitstring[bsl-1-i] = ntohl(bitstring[i]);
+    memcpy(bitstring, _bitstring, bsl*sizeof(uint32_t));
 #endif
   }
 

diff --git a/lib/biertable.cc b/lib/biertable.cc
@@ -25,7 +25,7 @@ CLICK_DECLS
 BierTable::BierTable(){}
 BierTable::~BierTable(){}
 
-bool BierTable::lookup(const bfrid &dst, bitstring &fbm, IP6Address &nxt, int &index, String &ifname) const {
+bool BierTable::lookup(const bfrid &dst, IP6Address &bfr_prefix, bitstring &fbm, IP6Address &nxt, int &index, String &ifname) const {
   int best = -1;
 
   for (int i = 0; i < _v.size(); i++) {
@@ -39,6 +39,7 @@ bool BierTable::lookup(const bfrid &dst, bitstring &fbm, IP6Address &nxt, int &i
     return false;
   else {
     nxt = _v[best]._nxt;
+    bfr_prefix = _v[best]._bfr_prefix;
     fbm = _v[best]._fbm;
     index = _v[best]._if_idx;
     ifname = _v[best]._if_name;
@@ -53,9 +54,10 @@ void BierTable::del(const bfrid &dst) {
   }
 }
 
-void BierTable::add(const bfrid &dst, const bitstring fbm, const IP6Address &nxt, int output, String ifname) {
+void BierTable::add(const bfrid &dst, const IP6Address bfr_prefix, const bitstring fbm, const IP6Address &nxt, int output, String ifname) {
   struct Entry e;
   e._dst = dst;
+  e._bfr_prefix = bfr_prefix;
   e._fbm = fbm;
   e._nxt = nxt;
   e._valid = 1;
@@ -76,10 +78,11 @@ void BierTable::add(const bfrid &dst, const bitstring fbm, const IP6Address &nxt
 String BierTable::dump() {
   StringAccum sa;
   if (_v.size())
-    sa << "# Active routes\n# BFR-id    F-BM    Nexthop    Ifindex\n";
+    sa << "# Active routes\n# BFR-id   BFR-prefix     F-BM    Nexthop    Ifindex\n";
   for (int i=0; i< _v.size(); i++) {
     if (_v[i]._valid) {
       sa << "    " << _v[i]._dst;
+      sa << "    " << _v[i]._bfr_prefix;
       sa << "      " << _v[i]._fbm.unparse();
       sa << "      " << _v[i]._nxt;
       sa << "      " << _v[i]._if_idx;