Reorganize source tree to use single autotools instance

Change-Id: I7b51f88292e057c6443b12224486f2d0c9f8ae23
Signed-off-by: Damjan Marion <damarion@cisco.com>

1 files changed, 1503 insertions, 0 deletions

diff --git a/src/vnet/fib/fib_entry.c b/src/vnet/fib/fib_entry.c
new file mode 100644
index 00000000000..24b506379ac
--- /dev/null
+++ b/src/vnet/fib/fib_entry.c
@@ -0,0 +1,1503 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * 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 <vlib/vlib.h>
+#include <vnet/ip/format.h>
+#include <vnet/ip/lookup.h>
+#include <vnet/adj/adj.h>
+#include <vnet/dpo/load_balance.h>
+#include <vnet/dpo/drop_dpo.h>
+
+#include <vnet/fib/fib_entry.h>
+#include <vnet/fib/fib_walk.h>
+#include <vnet/fib/fib_entry_src.h>
+#include <vnet/fib/fib_entry_cover.h>
+#include <vnet/fib/fib_table.h>
+#include <vnet/fib/fib_internal.h>
+#include <vnet/fib/fib_attached_export.h>
+#include <vnet/fib/fib_path_ext.h>
+
+/*
+ * Array of strings/names for the FIB sources
+ */
+static const char *fib_source_names[] = FIB_SOURCES;
+static const char *fib_attribute_names[] = FIB_ENTRY_ATTRIBUTES;
+
+/*
+ * Pool for all fib_entries
+ */
+static fib_entry_t *fib_entry_pool;
+
+fib_entry_t *
+fib_entry_get (fib_node_index_t index)
+{
+    return (pool_elt_at_index(fib_entry_pool, index));
+}
+
+static fib_node_t *
+fib_entry_get_node (fib_node_index_t index)
+{
+    return ((fib_node_t*)fib_entry_get(index));
+}
+
+fib_node_index_t
+fib_entry_get_index (const fib_entry_t * fib_entry)
+{
+    return (fib_entry - fib_entry_pool);
+}
+
+static fib_protocol_t
+fib_entry_get_proto (const fib_entry_t * fib_entry)
+{
+    return (fib_entry->fe_prefix.fp_proto);
+}
+
+fib_forward_chain_type_t
+fib_entry_get_default_chain_type (const fib_entry_t *fib_entry)
+{
+    switch (fib_entry->fe_prefix.fp_proto)
+    {
+    case FIB_PROTOCOL_IP4:
+	return (FIB_FORW_CHAIN_TYPE_UNICAST_IP4);
+    case FIB_PROTOCOL_IP6:
+	return (FIB_FORW_CHAIN_TYPE_UNICAST_IP6);
+    case FIB_PROTOCOL_MPLS:
+	if (MPLS_EOS == fib_entry->fe_prefix.fp_eos)
+	    /*
+	     * If the entry being asked is a eos-MPLS label entry,
+	     * then use the payload-protocol field, that we stashed there
+	     * for just this purpose
+	     */
+	    return (fib_forw_chain_type_from_dpo_proto(
+			fib_entry->fe_prefix.fp_payload_proto));
+	else
+	    return (FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS);
+    }
+
+    return (FIB_FORW_CHAIN_TYPE_UNICAST_IP4);
+}
+
+u8 *
+format_fib_entry (u8 * s, va_list * args)
+{
+    fib_forward_chain_type_t fct;
+    fib_entry_attribute_t attr;
+    fib_path_ext_t *path_ext;
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *src;
+    fib_node_index_t fei;
+    fib_source_t source;
+    u32 n_covered;
+    int level;
+
+    fei = va_arg (*args, fib_node_index_t);
+    level = va_arg (*args, int);
+    fib_entry = fib_entry_get(fei);
+
+    s = format (s, "%U", format_fib_prefix, &fib_entry->fe_prefix);
+
+    if (level >= FIB_ENTRY_FORMAT_DETAIL)
+    {
+	s = format (s, " fib:%d", fib_entry->fe_fib_index);
+	s = format (s, " index:%d", fib_entry_get_index(fib_entry));
+	s = format (s, " locks:%d", fib_entry->fe_node.fn_locks);
+
+	FOR_EACH_SRC_ADDED(fib_entry, src, source,
+        ({
+	    s = format (s, "\n  src:%s ",
+			fib_source_names[source]);
+	    s = fib_entry_src_format(fib_entry, source, s);
+	    s = format (s, " refs:%d ", src->fes_ref_count);
+	    if (FIB_ENTRY_FLAG_NONE != src->fes_entry_flags) {
+		s = format(s, "flags:");
+		FOR_EACH_FIB_ATTRIBUTE(attr) {
+		    if ((1<<attr) & src->fes_entry_flags) {
+			s = format (s, "%s,", fib_attribute_names[attr]);
+		    }
+		}
+	    }
+	    s = format (s, "\n");
+	    if (FIB_NODE_INDEX_INVALID != src->fes_pl)
+	    {
+		s = fib_path_list_format(src->fes_pl, s);
+	    }
+	    if (NULL != src->fes_path_exts)
+	    {
+		s = format(s, "    Extensions:");
+		vec_foreach(path_ext, src->fes_path_exts)
+		{
+		    s = format(s, "\n     %U", format_fib_path_ext, path_ext);
+		}
+	    }
+	}));
+    
+	n_covered = fib_entry_cover_get_size(fib_entry);
+	if (n_covered > 0) {
+	    s = format(s, "\n tracking %d covered: ", n_covered);
+	    s = fib_entry_cover_list_format(fib_entry, s);
+	}
+	s = fib_ae_import_format(fib_entry, s);
+	s = fib_ae_export_format(fib_entry, s);
+
+	s = format (s, "\n forwarding: ");
+    }
+    else
+    {
+	s = format (s, "\n");
+    }
+
+    fct = fib_entry_get_default_chain_type(fib_entry);
+
+    if (!dpo_id_is_valid(&fib_entry->fe_lb))
+    {
+	s = format (s, "  UNRESOLVED\n");
+	return (s);
+    }
+    else
+    {
+        s = format(s, "  %U-chain\n  %U",
+                   format_fib_forw_chain_type, fct,
+                   format_dpo_id,
+                   &fib_entry->fe_lb,
+                   2);
+        s = format(s, "\n");
+
+        if (level >= FIB_ENTRY_FORMAT_DETAIL2)
+        {
+            fib_entry_delegate_type_t fdt;
+            fib_entry_delegate_t *fed;
+
+            FOR_EACH_DELEGATE_CHAIN(fib_entry, fdt, fed,
+            {
+                s = format(s, "  %U-chain\n  %U",
+                           format_fib_forw_chain_type,
+                           fib_entry_delegate_type_to_chain_type(fdt),
+                           format_dpo_id, &fed->fd_dpo, 2);
+                s = format(s, "\n");
+            });
+        }
+    }
+
+    if (level >= FIB_ENTRY_FORMAT_DETAIL2)
+    {
+        s = format(s, "\nchildren:");
+        s = fib_node_children_format(fib_entry->fe_node.fn_children, s);
+    }
+
+    return (s);
+}
+
+static fib_entry_t*
+fib_entry_from_fib_node (fib_node_t *node)
+{
+#if CLIB_DEBUG > 0
+    ASSERT(FIB_NODE_TYPE_ENTRY == node->fn_type);
+#endif
+    return ((fib_entry_t*)node);
+}
+
+static void
+fib_entry_last_lock_gone (fib_node_t *node)
+{
+    fib_entry_delegate_type_t fdt;
+    fib_entry_delegate_t *fed;
+    fib_entry_t *fib_entry;
+
+    fib_entry = fib_entry_from_fib_node(node);
+
+    FOR_EACH_DELEGATE_CHAIN(fib_entry, fdt, fed,
+    {
+	dpo_reset(&fed->fd_dpo);
+        fib_entry_delegate_remove(fib_entry, fdt);
+    });
+
+    FIB_ENTRY_DBG(fib_entry, "last-lock");
+
+    fib_node_deinit(&fib_entry->fe_node);
+    // FIXME -RR Backwalk
+
+    ASSERT(0 == vec_len(fib_entry->fe_delegates));
+    vec_free(fib_entry->fe_delegates);
+    pool_put(fib_entry_pool, fib_entry);
+}
+
+static fib_entry_src_t*
+fib_entry_get_best_src_i (const fib_entry_t *fib_entry)
+{
+    fib_entry_src_t *bsrc;
+
+    /*
+     * the enum of sources is deliberately arranged in priority order
+     */
+    if (0 == vec_len(fib_entry->fe_srcs))
+    {
+	bsrc = NULL;
+    }
+    else
+    {
+	bsrc = vec_elt_at_index(fib_entry->fe_srcs, 0);
+    }
+
+    return (bsrc);
+}
+
+static fib_source_t
+fib_entry_src_get_source (const fib_entry_src_t *esrc)
+{
+    if (NULL != esrc)
+    {
+	return (esrc->fes_src);
+    }
+    return (FIB_SOURCE_MAX);
+}
+
+static fib_entry_flag_t
+fib_entry_src_get_flags (const fib_entry_src_t *esrc)
+{
+    if (NULL != esrc)
+    {
+	return (esrc->fes_entry_flags);
+    }
+    return (FIB_ENTRY_FLAG_NONE);
+}
+
+fib_entry_flag_t
+fib_entry_get_flags (fib_node_index_t fib_entry_index)
+{
+    return (fib_entry_get_flags_i(fib_entry_get(fib_entry_index)));
+}
+
+/*
+ * fib_entry_back_walk_notify
+ *
+ * A back walk has reach this entry.
+ */
+static fib_node_back_walk_rc_t
+fib_entry_back_walk_notify (fib_node_t *node,
+			    fib_node_back_walk_ctx_t *ctx)
+{
+    fib_entry_t *fib_entry;
+
+    fib_entry = fib_entry_from_fib_node(node);
+
+    if (FIB_NODE_BW_REASON_FLAG_EVALUATE & ctx->fnbw_reason        ||
+        FIB_NODE_BW_REASON_FLAG_ADJ_UPDATE & ctx->fnbw_reason      ||
+        FIB_NODE_BW_REASON_FLAG_ADJ_DOWN & ctx->fnbw_reason        ||
+	FIB_NODE_BW_REASON_FLAG_INTERFACE_UP & ctx->fnbw_reason    ||
+	FIB_NODE_BW_REASON_FLAG_INTERFACE_DOWN & ctx->fnbw_reason  ||
+	FIB_NODE_BW_REASON_FLAG_INTERFACE_DELETE & ctx->fnbw_reason)
+    {
+	fib_entry_src_action_reactivate(fib_entry,
+                                        fib_entry_get_best_source(
+                                            fib_entry_get_index(fib_entry)));
+    }
+
+    /*
+     * all other walk types can be reclassifed to a re-evaluate to
+     * all recursive dependents.
+     * By reclassifying we ensure that should any of these walk types meet
+     * they can be merged.
+     */
+    ctx->fnbw_reason = FIB_NODE_BW_REASON_FLAG_EVALUATE;
+
+    /*
+     * ... and nothing is forced sync from now on.
+     */
+    ctx->fnbw_flags &= ~FIB_NODE_BW_FLAG_FORCE_SYNC;
+
+    /*
+     * propagate the backwalk further if we haven't already reached the
+     * maximum depth.
+     */
+    fib_walk_sync(FIB_NODE_TYPE_ENTRY,
+		  fib_entry_get_index(fib_entry),
+		  ctx);
+
+    return (FIB_NODE_BACK_WALK_CONTINUE);
+}
+
+static void
+fib_entry_show_memory (void)
+{
+    u32 n_srcs = 0, n_exts = 0;
+    fib_entry_src_t *esrc;
+    fib_entry_t *entry;
+
+    fib_show_memory_usage("Entry",
+			  pool_elts(fib_entry_pool),
+			  pool_len(fib_entry_pool),
+			  sizeof(fib_entry_t));
+
+    pool_foreach(entry, fib_entry_pool,
+    ({
+	n_srcs += vec_len(entry->fe_srcs);
+	vec_foreach(esrc, entry->fe_srcs)
+	{
+	    n_exts += vec_len(esrc->fes_path_exts);
+	}
+    }));
+
+    fib_show_memory_usage("Entry Source",
+			  n_srcs, n_srcs, sizeof(fib_entry_src_t));
+    fib_show_memory_usage("Entry Path-Extensions",
+			  n_exts, n_exts,
+			  sizeof(fib_path_ext_t));
+}
+
+/*
+ * The FIB path-list's graph node virtual function table
+ */
+static const fib_node_vft_t fib_entry_vft = {
+    .fnv_get = fib_entry_get_node,
+    .fnv_last_lock = fib_entry_last_lock_gone,
+    .fnv_back_walk = fib_entry_back_walk_notify,
+    .fnv_mem_show = fib_entry_show_memory,
+};
+
+/**
+ * @brief Contribute the set of Adjacencies that this entry forwards with
+ * to build the uRPF list of its children
+ */
+void
+fib_entry_contribute_urpf (fib_node_index_t entry_index,
+			   index_t urpf)
+{
+    fib_entry_t *fib_entry;
+
+    fib_entry = fib_entry_get(entry_index);
+
+    return (fib_path_list_contribute_urpf(fib_entry->fe_parent, urpf));
+}
+
+/*
+ * fib_entry_contribute_forwarding
+ *
+ * Get an lock the forwarding information (DPO) contributed by the FIB entry.
+ */
+void
+fib_entry_contribute_forwarding (fib_node_index_t fib_entry_index,
+				 fib_forward_chain_type_t fct,
+				 dpo_id_t *dpo)
+{
+    fib_entry_delegate_t *fed;
+    fib_entry_t *fib_entry;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    if (fct == fib_entry_get_default_chain_type(fib_entry))
+    {
+        dpo_copy(dpo, &fib_entry->fe_lb);
+    }
+    else
+    {
+        fed = fib_entry_delegate_get(fib_entry,
+                                     fib_entry_chain_type_to_delegate_type(fct));
+
+        if (NULL == fed)
+        {
+            fed = fib_entry_delegate_find_or_add(
+                      fib_entry,
+                      fib_entry_chain_type_to_delegate_type(fct));
+            /*
+             * on-demand create eos/non-eos.
+             * There is no on-demand delete because:
+             *   - memory versus complexity & reliability:
+             *      leaving unrequired [n]eos LB arounds wastes memory, cleaning
+             *      then up on the right trigger is more code. i favour the latter.
+             */
+            fib_entry_src_mk_lb(fib_entry,
+                                fib_entry_get_best_src_i(fib_entry),
+                                fct,
+                                &fed->fd_dpo);
+        }
+
+        dpo_copy(dpo, &fed->fd_dpo);
+    }
+}
+
+const dpo_id_t *
+fib_entry_contribute_ip_forwarding (fib_node_index_t fib_entry_index)
+{
+    fib_forward_chain_type_t fct;
+    fib_entry_t *fib_entry;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+    fct = fib_entry_get_default_chain_type(fib_entry);
+
+    ASSERT((fct == FIB_FORW_CHAIN_TYPE_UNICAST_IP4 ||
+            fct == FIB_FORW_CHAIN_TYPE_UNICAST_IP6));
+
+    return (&fib_entry->fe_lb);
+}
+
+adj_index_t
+fib_entry_get_adj (fib_node_index_t fib_entry_index)
+{
+    const dpo_id_t *dpo;
+
+    dpo = fib_entry_contribute_ip_forwarding(fib_entry_index);
+    dpo = load_balance_get_bucket(dpo->dpoi_index, 0);
+
+    if (dpo_is_adj(dpo))
+    {
+	return (dpo->dpoi_index);
+    }
+    return (ADJ_INDEX_INVALID);
+}
+
+fib_node_index_t
+fib_entry_get_path_list (fib_node_index_t fib_entry_index)
+{
+    fib_entry_t *fib_entry;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    return (fib_entry->fe_parent);
+}
+
+u32
+fib_entry_child_add (fib_node_index_t fib_entry_index,
+		     fib_node_type_t child_type,
+		     fib_node_index_t child_index)
+{
+    return (fib_node_child_add(FIB_NODE_TYPE_ENTRY,
+                               fib_entry_index,
+                               child_type,
+                               child_index));
+};
+
+void
+fib_entry_child_remove (fib_node_index_t fib_entry_index,
+			u32 sibling_index)
+{
+    fib_node_child_remove(FIB_NODE_TYPE_ENTRY,
+                          fib_entry_index,
+                          sibling_index);
+
+    if (0 == fib_node_get_n_children(FIB_NODE_TYPE_ENTRY,
+                                     fib_entry_index))
+    {
+        /*
+         * if there are no children left then there is no reason to keep
+         * the non-default forwarding chains. those chains are built only
+         * because the children want them.
+         */
+        fib_entry_delegate_type_t fdt;
+        fib_entry_delegate_t *fed;
+        fib_entry_t *fib_entry;
+
+        fib_entry = fib_entry_get(fib_entry_index);
+
+        FOR_EACH_DELEGATE_CHAIN(fib_entry, fdt, fed,
+        {
+            dpo_reset(&fed->fd_dpo);
+            fib_entry_delegate_remove(fib_entry, fdt);
+        });
+    }
+}
+
+static fib_entry_t *
+fib_entry_alloc (u32 fib_index,
+		 const fib_prefix_t *prefix,
+		 fib_node_index_t *fib_entry_index)
+{
+    fib_entry_t *fib_entry;
+    fib_prefix_t *fep;
+
+    pool_get(fib_entry_pool, fib_entry);
+    memset(fib_entry, 0, sizeof(*fib_entry));
+
+    fib_node_init(&fib_entry->fe_node,
+		  FIB_NODE_TYPE_ENTRY);
+
+    fib_entry->fe_fib_index = fib_index;
+
+    /*
+     * the one time we need to update the const prefix is when
+     * the entry is first created
+     */
+    fep = (fib_prefix_t*)&(fib_entry->fe_prefix);
+    *fep = *prefix;
+
+    if (FIB_PROTOCOL_MPLS == fib_entry->fe_prefix.fp_proto)
+    {
+	fep->fp_len = 21;
+	if (MPLS_NON_EOS == fep->fp_eos)
+	{
+	    fep->fp_payload_proto = DPO_PROTO_MPLS;
+	}
+    	ASSERT(DPO_PROTO_NONE != fib_entry->fe_prefix.fp_payload_proto);
+    }
+
+    dpo_reset(&fib_entry->fe_lb);
+
+    *fib_entry_index = fib_entry_get_index(fib_entry);
+
+    FIB_ENTRY_DBG(fib_entry, "alloc");
+
+    return (fib_entry);
+}
+
+static void
+fib_entry_post_flag_update_actions (fib_entry_t *fib_entry,
+				    fib_source_t source,
+				    fib_entry_flag_t old_flags)
+{
+    /*
+     * handle changes to attached export for import entries
+     */
+    int is_import  = (FIB_ENTRY_FLAG_IMPORT & fib_entry_get_flags_i(fib_entry));
+    int was_import = (FIB_ENTRY_FLAG_IMPORT & old_flags);
+
+    if (!was_import && is_import)
+    {
+	/*
+	 * transition from not exported to exported
+	 */
+
+	/*
+	 * there is an assumption here that the entry resolves via only
+	 * one interface and that it is the cross VRF interface.
+	 */
+	u32 sw_if_index = fib_path_list_get_resolving_interface(fib_entry->fe_parent);
+
+	fib_attached_export_import(fib_entry,
+				   fib_table_get_index_for_sw_if_index(
+				       fib_entry_get_proto(fib_entry),
+                                       sw_if_index));
+    }
+    else if (was_import && !is_import)
+    {
+	/*
+	 * transition from exported to not exported
+	 */
+	fib_attached_export_purge(fib_entry);
+    }
+    /*
+     * else
+     *   no change. nothing to do.
+     */
+
+    /*
+     * handle changes to attached export for export entries
+     */
+    int is_attached  = (FIB_ENTRY_FLAG_ATTACHED & fib_entry_get_flags_i(fib_entry));
+    int was_attached = (FIB_ENTRY_FLAG_ATTACHED & old_flags);
+
+    if (!was_attached && is_attached)
+    {
+	/*
+	 * transition to attached. time to export
+	 */
+	// FIXME
+    }
+    // else FIXME
+}
+
+static void
+fib_entry_post_install_actions (fib_entry_t *fib_entry,
+				fib_source_t source,
+				fib_entry_flag_t old_flags)
+{
+    fib_entry_post_flag_update_actions(fib_entry, source, old_flags);
+    fib_entry_src_action_installed(fib_entry, source);
+}
+
+fib_node_index_t
+fib_entry_create (u32 fib_index,
+		  const fib_prefix_t *prefix,
+		  fib_source_t source,
+		  fib_entry_flag_t flags,
+		  const fib_route_path_t *paths)
+{
+    fib_node_index_t fib_entry_index;
+    fib_entry_t *fib_entry;
+
+    ASSERT(0 < vec_len(paths));
+
+    fib_entry = fib_entry_alloc(fib_index, prefix, &fib_entry_index);
+
+    /*
+     * since this is a new entry create, we don't need to check for winning
+     * sources - there is only one.
+     */
+    fib_entry = fib_entry_src_action_add(fib_entry, source, flags,
+                                         drop_dpo_get(
+                                             fib_proto_to_dpo(
+                                                 fib_entry_get_proto(fib_entry))));
+    fib_entry_src_action_path_swap(fib_entry,
+				   source,
+				   flags,
+				   paths);
+    /*
+     * handle possible realloc's by refetching the pointer
+     */
+    fib_entry = fib_entry_get(fib_entry_index);
+    fib_entry_src_action_activate(fib_entry, source);
+
+    fib_entry_post_install_actions(fib_entry, source, FIB_ENTRY_FLAG_NONE);
+
+    return (fib_entry_index);
+}
+
+fib_node_index_t
+fib_entry_create_special (u32 fib_index,
+			  const fib_prefix_t *prefix,
+			  fib_source_t source,
+			  fib_entry_flag_t flags,
+			  const dpo_id_t *dpo)
+{
+    fib_node_index_t fib_entry_index;
+    fib_entry_t *fib_entry;
+
+    /*
+     * create and initiliase the new enty
+     */
+    fib_entry = fib_entry_alloc(fib_index, prefix, &fib_entry_index);
+
+    /*
+     * create the path-list
+     */
+    fib_entry = fib_entry_src_action_add(fib_entry, source, flags, dpo);
+    fib_entry_src_action_activate(fib_entry, source);
+
+    fib_entry_post_install_actions(fib_entry, source, FIB_ENTRY_FLAG_NONE);
+
+    return (fib_entry_index);
+}
+
+static void
+fib_entry_post_update_actions (fib_entry_t *fib_entry,
+			       fib_source_t source,
+			       fib_entry_flag_t old_flags)
+{
+    /*
+     * backwalk to children to inform then of the change to forwarding.
+     */
+    fib_node_back_walk_ctx_t bw_ctx = {
+	.fnbw_reason = FIB_NODE_BW_REASON_FLAG_EVALUATE,
+    };
+
+    fib_walk_sync(FIB_NODE_TYPE_ENTRY, fib_entry_get_index(fib_entry), &bw_ctx);
+
+    /*
+     * then inform any covered prefixes
+     */
+    fib_entry_cover_update_notify(fib_entry);
+
+    fib_entry_post_install_actions(fib_entry, source, old_flags);
+}
+
+static void
+fib_entry_source_change (fib_entry_t *fib_entry,
+			 fib_source_t best_source,
+			 fib_source_t new_source,
+			 fib_entry_flag_t old_flags)
+{
+    /*
+     * if the path list for the source passed is invalid,
+     * then we need to create a new one. else we are updating
+     * an existing.
+     */
+    if (new_source < best_source)
+    {
+	/*
+	 * we have a new winning source.
+	 */
+	fib_entry_src_action_deactivate(fib_entry, best_source);
+	fib_entry_src_action_activate(fib_entry, new_source);
+    }
+    else if (new_source > best_source)
+    {
+	/*
+	 * the new source loses. nothing to do here.
+	 * the data from the source is saved in the path-list created
+	 */
+	return;
+    }
+    else
+    {
+	/*
+	 * the new source is one this entry already has.
+	 * But the path-list was updated, which will contribute new forwarding,
+	 * so install it.
+	 */
+	fib_entry_src_action_deactivate(fib_entry, new_source);
+	fib_entry_src_action_activate(fib_entry, new_source);
+    }
+
+    fib_entry_post_update_actions(fib_entry, new_source, old_flags);
+}
+
+void
+fib_entry_special_add (fib_node_index_t fib_entry_index,
+		       fib_source_t source,
+		       fib_entry_flag_t flags,
+		       const dpo_id_t *dpo)
+{
+    fib_source_t best_source;
+    fib_entry_flag_t bflags;
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *bsrc;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    bsrc = fib_entry_get_best_src_i(fib_entry);
+    best_source = fib_entry_src_get_source(bsrc);
+    bflags = fib_entry_src_get_flags(bsrc);
+
+    fib_entry = fib_entry_src_action_add(fib_entry, source, flags, dpo);
+    fib_entry_source_change(fib_entry, best_source, source, bflags);
+}
+
+void
+fib_entry_special_update (fib_node_index_t fib_entry_index,
+			  fib_source_t source,
+			  fib_entry_flag_t flags,
+			  const dpo_id_t *dpo)
+{
+    fib_source_t best_source;
+    fib_entry_flag_t bflags;
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *bsrc;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    bsrc = fib_entry_get_best_src_i(fib_entry);
+    best_source = fib_entry_src_get_source(bsrc);
+    bflags = fib_entry_src_get_flags(bsrc);
+
+    fib_entry = fib_entry_src_action_update(fib_entry, source, flags, dpo);
+    fib_entry_source_change(fib_entry, best_source, source, bflags);
+}
+
+
+void
+fib_entry_path_add (fib_node_index_t fib_entry_index,
+		    fib_source_t source,
+		    fib_entry_flag_t flags,
+		    const fib_route_path_t *rpath)
+{
+    fib_source_t best_source;
+    fib_entry_flag_t bflags;
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *bsrc;
+
+    ASSERT(1 == vec_len(rpath));
+
+    fib_entry = fib_entry_get(fib_entry_index);
+    ASSERT(NULL != fib_entry);
+
+    bsrc = fib_entry_get_best_src_i(fib_entry);
+    best_source = fib_entry_src_get_source(bsrc);
+    bflags = fib_entry_src_get_flags(bsrc);
+    
+    fib_entry = fib_entry_src_action_path_add(fib_entry, source, flags, rpath);
+
+    /*
+     * if the path list for the source passed is invalid,
+     * then we need to create a new one. else we are updating
+     * an existing.
+     */
+    if (source < best_source)
+    {
+	/*
+	 * we have a new winning source.
+	 */
+	fib_entry_src_action_deactivate(fib_entry, best_source);
+	fib_entry_src_action_activate(fib_entry, source);
+    }
+    else if (source > best_source)
+    {
+	/*
+	 * the new source loses. nothing to do here.
+	 * the data from the source is saved in the path-list created
+	 */
+	return;
+    }
+    else
+    {
+	/*
+	 * the new source is one this entry already has.
+	 * But the path-list was updated, which will contribute new forwarding,
+	 * so install it.
+	 */
+	fib_entry_src_action_deactivate(fib_entry, source);
+	fib_entry_src_action_activate(fib_entry, source);
+    }
+
+    fib_entry_post_update_actions(fib_entry, source, bflags);
+}
+
+/*
+ * fib_entry_path_remove
+ *
+ * remove a path from the entry.
+ * return the fib_entry's index if it is still present, INVALID otherwise.
+ */
+fib_entry_src_flag_t
+fib_entry_path_remove (fib_node_index_t fib_entry_index,
+		       fib_source_t source,
+		       const fib_route_path_t *rpath)
+{
+    fib_entry_src_flag_t sflag;
+    fib_source_t best_source;
+    fib_entry_flag_t bflags;
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *bsrc;
+
+    ASSERT(1 == vec_len(rpath));
+
+    fib_entry = fib_entry_get(fib_entry_index);
+    ASSERT(NULL != fib_entry);
+
+    bsrc = fib_entry_get_best_src_i(fib_entry);
+    best_source = fib_entry_src_get_source(bsrc);
+    bflags = fib_entry_src_get_flags(bsrc);
+
+    sflag = fib_entry_src_action_path_remove(fib_entry, source, rpath);
+
+    /*
+     * if the path list for the source passed is invalid,
+     * then we need to create a new one. else we are updating
+     * an existing.
+     */
+    if (source < best_source )
+    {
+	/*
+	 * Que! removing a path from a source that is better than the
+	 * one this entry is using.
+	 */
+	ASSERT(0);
+    }
+    else if (source > best_source )
+    {
+	/*
+	 * the source is not the best. nothing to do.
+	 */
+	return (FIB_ENTRY_SRC_FLAG_ADDED);
+    }
+    else
+    {
+	/*
+	 * removing a path from the path-list we were using.
+	 */
+	if (!(FIB_ENTRY_SRC_FLAG_ADDED & sflag))
+	{
+	    /*
+	     * the last path from the source was removed.
+	     * fallback to lower source
+	     */
+	    bsrc = fib_entry_get_best_src_i(fib_entry);
+	    best_source = fib_entry_src_get_source(bsrc);
+
+	    if (FIB_SOURCE_MAX == best_source) {
+		/*
+		 * no more sources left. this entry is toast.
+		 */
+		fib_entry_src_action_uninstall(fib_entry);
+		fib_entry_post_flag_update_actions(fib_entry, source, bflags);
+
+		return (FIB_ENTRY_SRC_FLAG_NONE);
+	    }
+	    else
+	    {
+		fib_entry_src_action_activate(fib_entry, best_source);
+		source = best_source;
+	    }
+	}
+	else
+	{
+	    /*
+	     * re-install the new forwarding information
+	     */
+	    fib_entry_src_action_deactivate(fib_entry, source);
+	    fib_entry_src_action_activate(fib_entry, source);
+	}
+    }
+
+    fib_entry_post_update_actions(fib_entry, source, bflags);
+
+    /*
+     * still have sources
+     */
+    return (FIB_ENTRY_SRC_FLAG_ADDED);
+}
+
+/*
+ * fib_entry_special_remove
+ *
+ * remove a special source from the entry.
+ * return the fib_entry's index if it is still present, INVALID otherwise.
+ */
+fib_entry_src_flag_t
+fib_entry_special_remove (fib_node_index_t fib_entry_index,
+			  fib_source_t source)
+{
+    fib_entry_src_flag_t sflag;
+    fib_source_t best_source;
+    fib_entry_flag_t bflags;
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *bsrc;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+    ASSERT(NULL != fib_entry);
+
+    bsrc = fib_entry_get_best_src_i(fib_entry);
+    best_source = fib_entry_src_get_source(bsrc);
+    bflags = fib_entry_src_get_flags(bsrc);
+
+    sflag = fib_entry_src_action_remove(fib_entry, source);
+
+    /*
+     * if the path list for the source passed is invalid,
+     * then we need to create a new one. else we are updating
+     * an existing.
+     */
+    if (source < best_source )
+    {
+	/*
+	 * Que! removing a path from a source that is better than the
+	 * one this entry is using. This can only mean it is a source
+         * this prefix does not have.
+	 */
+        return (FIB_ENTRY_SRC_FLAG_ADDED);
+    }
+    else if (source > best_source ) {
+	/*
+	 * the source is not the best. nothing to do.
+	 */
+	return (FIB_ENTRY_SRC_FLAG_ADDED);
+    }
+    else
+    {
+	if (!(FIB_ENTRY_SRC_FLAG_ADDED & sflag))
+	{
+	    /*
+	     * the source was removed. use the next best.
+	     */
+	    bsrc = fib_entry_get_best_src_i(fib_entry);
+	    best_source = fib_entry_src_get_source(bsrc);
+
+	    if (FIB_SOURCE_MAX == best_source) {
+		/*
+		 * no more sources left. this entry is toast.
+		 */
+		fib_entry_src_action_uninstall(fib_entry);
+		fib_entry_post_flag_update_actions(fib_entry, source, bflags);
+
+		return (FIB_ENTRY_SRC_FLAG_NONE);
+	    }
+	    else
+	    {
+		fib_entry_src_action_activate(fib_entry, best_source);
+		source = best_source;
+	    }
+	}
+	else
+	{
+	    /*
+	     * re-install the new forwarding information
+	     */
+	    fib_entry_src_action_reactivate(fib_entry, source);
+	}
+    }
+
+    fib_entry_post_update_actions(fib_entry, source, bflags);
+
+    /*
+     * still have sources
+     */
+    return (FIB_ENTRY_SRC_FLAG_ADDED);
+}
+
+/**
+ * fib_entry_delete
+ *
+ * The source is withdrawing all the paths it provided
+ */
+fib_entry_src_flag_t
+fib_entry_delete (fib_node_index_t fib_entry_index,
+		  fib_source_t source)
+{
+    return (fib_entry_special_remove(fib_entry_index, source));
+}
+
+/**
+ * fib_entry_update
+ *
+ * The source has provided a new set of paths that will replace the old.
+ */
+void
+fib_entry_update (fib_node_index_t fib_entry_index,
+		  fib_source_t source,
+		  fib_entry_flag_t flags,
+		  const fib_route_path_t *paths)
+{
+    fib_source_t best_source;
+    fib_entry_flag_t bflags;
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *bsrc;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+    ASSERT(NULL != fib_entry);
+
+    bsrc = fib_entry_get_best_src_i(fib_entry);
+    best_source = fib_entry_src_get_source(bsrc);
+    bflags = fib_entry_src_get_flags(bsrc);
+
+    fib_entry_src_action_path_swap(fib_entry,
+				   source,
+				   flags,
+				   paths);
+    /*
+     * handle possible realloc's by refetching the pointer
+     */
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    /*
+     * if the path list for the source passed is invalid,
+     * then we need to create a new one. else we are updating
+     * an existing.
+     */
+    if (source < best_source)
+    {
+	/*
+	 * we have a new winning source.
+	 */
+	fib_entry_src_action_deactivate(fib_entry, best_source);
+	fib_entry_src_action_activate(fib_entry, source);
+    }
+    else if (source > best_source) {
+	/*
+	 * the new source loses. nothing to do here.
+	 * the data from the source is saved in the path-list created
+	 */
+	return;
+    }
+    else
+    {
+	/*
+	 * the new source is one this entry already has.
+	 * But the path-list was updated, which will contribute new forwarding,
+	 * so install it.
+	 */
+	fib_entry_src_action_deactivate(fib_entry, source);
+	fib_entry_src_action_activate(fib_entry, source);
+    }
+
+    fib_entry_post_update_actions(fib_entry, source, bflags);
+}
+
+
+/*
+ * fib_entry_cover_changed
+ *
+ * this entry is tracking its cover and that cover has changed.
+ */
+void
+fib_entry_cover_changed (fib_node_index_t fib_entry_index)
+{
+    fib_entry_src_cover_res_t res = {
+	.install = !0,
+	.bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
+    };
+    fib_source_t source, best_source;
+    fib_entry_flag_t bflags;
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *esrc;
+    u32 index;
+
+    bflags = FIB_ENTRY_FLAG_NONE;
+    best_source = FIB_SOURCE_FIRST;
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    fib_attached_export_cover_change(fib_entry);
+
+    /*
+     * propagate the notificuation to each of the added sources
+     */
+    index = 0;
+    FOR_EACH_SRC_ADDED(fib_entry, esrc, source,
+    ({
+	if (0 == index)
+	{
+	    /*
+	     * only the best source gets to set the back walk flags
+	     */
+	    res = fib_entry_src_action_cover_change(fib_entry, source);
+            bflags = fib_entry_src_get_flags(esrc);
+            best_source = fib_entry_src_get_source(esrc);
+	}
+	else
+	{
+	    fib_entry_src_action_cover_change(fib_entry, source);
+	}
+	index++;
+    }));
+
+    if (res.install)
+    {
+	fib_entry_src_action_reactivate(fib_entry,
+					fib_entry_src_get_source(
+					    fib_entry_get_best_src_i(fib_entry)));
+        fib_entry_post_install_actions(fib_entry, best_source, bflags);
+    }
+    else
+    {
+	fib_entry_src_action_uninstall(fib_entry);
+    }
+
+    if (FIB_NODE_BW_REASON_FLAG_NONE != res.bw_reason)
+    {
+	/*
+	 * time for walkies fido.
+	 */
+	fib_node_back_walk_ctx_t bw_ctx = {
+	    .fnbw_reason = res.bw_reason,
+        };
+
+	fib_walk_sync(FIB_NODE_TYPE_ENTRY, fib_entry_index, &bw_ctx);
+    }
+}
+
+/*
+ * fib_entry_cover_updated
+ *
+ * this entry is tracking its cover and that cover has been updated
+ * (i.e. its forwarding information has changed).
+ */
+void
+fib_entry_cover_updated (fib_node_index_t fib_entry_index)
+{
+    fib_entry_src_cover_res_t res = {
+	.install = !0,
+	.bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
+    };
+    fib_source_t source, best_source;
+    fib_entry_flag_t bflags;
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *esrc;
+    u32 index;
+
+    bflags = FIB_ENTRY_FLAG_NONE;
+    best_source = FIB_SOURCE_FIRST;
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    fib_attached_export_cover_update(fib_entry);
+
+    /*
+     * propagate the notificuation to each of the added sources
+     */
+    index = 0;
+    FOR_EACH_SRC_ADDED(fib_entry, esrc, source,
+    ({
+	if (0 == index)
+	{
+	    /*
+	     * only the best source gets to set the back walk flags
+	     */
+	    res = fib_entry_src_action_cover_update(fib_entry, source);
+            bflags = fib_entry_src_get_flags(esrc);
+            best_source = fib_entry_src_get_source(esrc);
+	}
+	else
+	{
+	    fib_entry_src_action_cover_update(fib_entry, source);
+	}
+	index++;
+    }));
+
+    if (res.install)
+    {
+	fib_entry_src_action_reactivate(fib_entry,
+					fib_entry_src_get_source(
+					    fib_entry_get_best_src_i(fib_entry)));
+        fib_entry_post_install_actions(fib_entry, best_source, bflags);
+    }
+    else
+    {
+	fib_entry_src_action_uninstall(fib_entry);
+    }
+
+    if (FIB_NODE_BW_REASON_FLAG_NONE != res.bw_reason)
+    {
+	/*
+	 * time for walkies fido.
+	 */
+	fib_node_back_walk_ctx_t bw_ctx = {
+	    .fnbw_reason = res.bw_reason,
+        };
+
+	fib_walk_sync(FIB_NODE_TYPE_ENTRY, fib_entry_index, &bw_ctx);
+    }
+}
+
+int
+fib_entry_recursive_loop_detect (fib_node_index_t entry_index,
+				 fib_node_index_t **entry_indicies)
+{
+    fib_entry_t *fib_entry;
+    int was_looped, is_looped;
+
+    fib_entry = fib_entry_get(entry_index);
+
+    if (FIB_NODE_INDEX_INVALID != fib_entry->fe_parent)
+    {
+	fib_node_index_t *entries = *entry_indicies;
+
+	vec_add1(entries, entry_index);
+	was_looped = fib_path_list_is_looped(fib_entry->fe_parent);
+	is_looped = fib_path_list_recursive_loop_detect(fib_entry->fe_parent,
+							&entries);
+
+	*entry_indicies = entries;
+
+	if (!!was_looped != !!is_looped)
+	{
+	    /*
+	     * re-evaluate all the entry's forwarding
+	     * NOTE: this is an inplace modify
+	     */
+            fib_entry_delegate_type_t fdt;
+            fib_entry_delegate_t *fed;
+
+            FOR_EACH_DELEGATE_CHAIN(fib_entry, fdt, fed,
+            {
+                fib_entry_src_mk_lb(fib_entry,
+                                    fib_entry_get_best_src_i(fib_entry),
+                                    fib_entry_delegate_type_to_chain_type(fdt),
+                                    &fed->fd_dpo);
+	    });
+	}
+    }
+    else
+    {
+	/*
+	 * the entry is currently not linked to a path-list. this happens
+	 * when it is this entry that is re-linking path-lists and has thus
+	 * broken the loop
+	 */
+	is_looped = 0;
+    }
+
+    return (is_looped);
+}
+
+u32
+fib_entry_get_resolving_interface (fib_node_index_t entry_index)
+{
+    fib_entry_t *fib_entry;
+
+    fib_entry = fib_entry_get(entry_index);
+
+    return (fib_path_list_get_resolving_interface(fib_entry->fe_parent));
+}
+
+fib_source_t
+fib_entry_get_best_source (fib_node_index_t entry_index)
+{
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *bsrc;
+
+    fib_entry = fib_entry_get(entry_index);
+
+    bsrc = fib_entry_get_best_src_i(fib_entry);
+    return (fib_entry_src_get_source(bsrc));
+}
+
+static int
+fib_ip4_address_compare (const ip4_address_t * a1,
+                         const ip4_address_t * a2)
+{
+    /*
+     * IP addresses are unsiged ints. the return value here needs to be signed
+     * a simple subtraction won't cut it.
+     * If the addresses are the same, the sort order is undefiend, so phoey.
+     */
+    return ((clib_net_to_host_u32(a1->data_u32) >
+	     clib_net_to_host_u32(a2->data_u32) ) ?
+	    1 : -1);
+}
+
+static int
+fib_ip6_address_compare (const ip6_address_t * a1,
+                         const ip6_address_t * a2)
+{
+  int i;
+  for (i = 0; i < ARRAY_LEN (a1->as_u16); i++)
+  {
+      int cmp = (clib_net_to_host_u16 (a1->as_u16[i]) -
+		 clib_net_to_host_u16 (a2->as_u16[i]));
+      if (cmp != 0)
+	  return cmp;
+  }
+  return 0;
+}
+
+static int
+fib_entry_cmp (fib_node_index_t fib_entry_index1,
+	       fib_node_index_t fib_entry_index2)
+{
+    fib_entry_t *fib_entry1, *fib_entry2;
+    int cmp = 0;
+
+    fib_entry1 = fib_entry_get(fib_entry_index1);
+    fib_entry2 = fib_entry_get(fib_entry_index2);
+
+    switch (fib_entry1->fe_prefix.fp_proto)
+    {
+    case FIB_PROTOCOL_IP4:
+        cmp = fib_ip4_address_compare(&fib_entry1->fe_prefix.fp_addr.ip4,
+                                      &fib_entry2->fe_prefix.fp_addr.ip4);
+        break;
+    case FIB_PROTOCOL_IP6:
+        cmp = fib_ip6_address_compare(&fib_entry1->fe_prefix.fp_addr.ip6,
+                                      &fib_entry2->fe_prefix.fp_addr.ip6);
+        break;
+    case FIB_PROTOCOL_MPLS:
+	cmp = (fib_entry1->fe_prefix.fp_label - fib_entry2->fe_prefix.fp_label);
+
+	if (0 == cmp)
+	{
+	    cmp = (fib_entry1->fe_prefix.fp_eos - fib_entry2->fe_prefix.fp_eos);
+	}
+        break;
+    }
+
+    if (0 == cmp) {
+	cmp = (fib_entry1->fe_prefix.fp_len - fib_entry2->fe_prefix.fp_len);
+    }
+    return (cmp);   
+}
+
+int
+fib_entry_cmp_for_sort (void *i1, void *i2)
+{
+    fib_node_index_t *fib_entry_index1 = i1, *fib_entry_index2 = i2;
+
+    return (fib_entry_cmp(*fib_entry_index1,
+			  *fib_entry_index2));
+}
+
+void
+fib_entry_lock (fib_node_index_t fib_entry_index)
+{
+    fib_entry_t *fib_entry;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    fib_node_lock(&fib_entry->fe_node);
+}
+
+void
+fib_entry_unlock (fib_node_index_t fib_entry_index)
+{
+    fib_entry_t *fib_entry;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    fib_node_unlock(&fib_entry->fe_node);
+}
+
+void
+fib_entry_module_init (void)
+{
+    fib_node_register_type (FIB_NODE_TYPE_ENTRY, &fib_entry_vft);
+}
+
+void
+fib_entry_encode (fib_node_index_t fib_entry_index,
+		  fib_route_path_encode_t **api_rpaths)
+{
+    fib_entry_t *fib_entry;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+    fib_path_list_walk(fib_entry->fe_parent, fib_path_encode, api_rpaths);
+}
+
+void
+fib_entry_get_prefix (fib_node_index_t fib_entry_index,
+		      fib_prefix_t *pfx)
+{
+    fib_entry_t *fib_entry;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+    *pfx = fib_entry->fe_prefix;
+}
+
+u32
+fib_entry_get_fib_index (fib_node_index_t fib_entry_index)
+{
+    fib_entry_t *fib_entry;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    return (fib_entry->fe_fib_index);
+}
+
+u32
+fib_entry_pool_size (void)
+{
+    return (pool_elts(fib_entry_pool));
+}
+
+static clib_error_t *
+show_fib_entry_command (vlib_main_t * vm,
+			unformat_input_t * input,
+			vlib_cli_command_t * cmd)
+{
+    fib_node_index_t fei;
+
+    if (unformat (input, "%d", &fei))
+    {
+	/*
+	 * show one in detail
+	 */
+	if (!pool_is_free_index(fib_entry_pool, fei))
+	{
+	    vlib_cli_output (vm, "%d@%U",
+			     fei,
+			     format_fib_entry, fei,
+			     FIB_ENTRY_FORMAT_DETAIL2);
+	}
+	else
+	{
+	    vlib_cli_output (vm, "entry %d invalid", fei);
+	}
+    }
+    else
+    {
+	/*
+	 * show all
+	 */
+	vlib_cli_output (vm, "FIB Entries:");
+	pool_foreach_index(fei, fib_entry_pool,
+        ({
+	    vlib_cli_output (vm, "%d@%U",
+			     fei,
+			     format_fib_entry, fei,
+			     FIB_ENTRY_FORMAT_BRIEF);
+	}));
+    }
+
+    return (NULL);
+}
+
+VLIB_CLI_COMMAND (show_fib_entry, static) = {
+  .path = "show fib entry",
+  .function = show_fib_entry_command,
+  .short_help = "show fib entry",
+};