Reorganize source tree to use single autotools instance

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

1 files changed, 1456 insertions, 0 deletions

diff --git a/src/vnet/fib/fib_entry_src.c b/src/vnet/fib/fib_entry_src.c
new file mode 100644
index 00000000000..060fac941d2
--- /dev/null
+++ b/src/vnet/fib/fib_entry_src.c
@@ -0,0 +1,1456 @@
+/*
+ * 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 <vnet/adj/adj.h>
+#include <vnet/dpo/load_balance.h>
+#include <vnet/dpo/mpls_label_dpo.h>
+#include <vnet/dpo/drop_dpo.h>
+
+#include <vnet/fib/fib_entry_src.h>
+#include <vnet/fib/fib_table.h>
+#include <vnet/fib/fib_path_ext.h>
+#include <vnet/fib/fib_urpf_list.h>
+
+/*
+ * per-source type vft
+ */
+static fib_entry_src_vft_t fib_entry_src_vft[FIB_SOURCE_MAX];
+
+static fib_protocol_t
+fib_entry_get_proto (const fib_entry_t * fib_entry)
+{
+    return (fib_entry->fe_prefix.fp_proto);
+}
+
+void
+fib_entry_src_register (fib_source_t source,
+			const fib_entry_src_vft_t *vft)
+{
+    fib_entry_src_vft[source] = *vft;
+}
+
+static int
+fib_entry_src_cmp_for_sort (void * v1,
+			    void * v2)
+{
+    fib_entry_src_t *esrc1 = v1, *esrc2 = v2;
+
+    return (esrc1->fes_src - esrc2->fes_src);
+}
+
+void
+fib_entry_src_action_init (fib_entry_t *fib_entry,
+			   fib_source_t source)
+
+{
+    fib_entry_src_t esrc = {
+	.fes_pl = FIB_NODE_INDEX_INVALID,
+	.fes_flags = FIB_ENTRY_SRC_FLAG_NONE,
+	.fes_src = source,
+    };
+
+    if (NULL != fib_entry_src_vft[source].fesv_init)
+    {
+	fib_entry_src_vft[source].fesv_init(&esrc);
+    }
+
+    vec_add1(fib_entry->fe_srcs, esrc);
+    vec_sort_with_function(fib_entry->fe_srcs,
+			   fib_entry_src_cmp_for_sort);
+}
+
+static fib_entry_src_t *
+fib_entry_src_find (const fib_entry_t *fib_entry,
+		    fib_source_t source,
+		    u32 *index)
+
+{
+    fib_entry_src_t *esrc;
+    int ii;
+
+    ii = 0;
+    vec_foreach(esrc, fib_entry->fe_srcs)
+    {
+	if (esrc->fes_src == source)
+	{
+	    if (NULL != index)
+	    {
+		*index = ii;
+	    }
+	    return (esrc);
+	}
+	else
+	{
+	    ii++;
+	}
+    }
+
+    return (NULL);
+}
+
+int
+fib_entry_is_sourced (fib_node_index_t fib_entry_index,
+                      fib_source_t source)
+{
+    fib_entry_t *fib_entry;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    return (NULL != fib_entry_src_find(fib_entry, source, NULL));
+}
+
+static fib_entry_src_t *
+fib_entry_src_find_or_create (fib_entry_t *fib_entry,
+			      fib_source_t source,
+			      u32 *index)
+{
+    fib_entry_src_t *esrc;
+
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    if (NULL == esrc)
+    {
+	fib_entry_src_action_init(fib_entry, source);
+    }
+
+    return (fib_entry_src_find(fib_entry, source, NULL));
+}
+
+void
+fib_entry_src_action_deinit (fib_entry_t *fib_entry,
+			     fib_source_t source)
+
+{
+    fib_entry_src_t *esrc;
+    u32 index = ~0;
+
+    esrc = fib_entry_src_find(fib_entry, source, &index);
+
+    ASSERT(NULL != esrc);
+
+    if (NULL != fib_entry_src_vft[source].fesv_deinit)
+    {
+	fib_entry_src_vft[source].fesv_deinit(esrc);
+    }
+
+    vec_free(esrc->fes_path_exts);
+    vec_del1(fib_entry->fe_srcs, index);
+}
+
+fib_entry_src_cover_res_t
+fib_entry_src_action_cover_change (fib_entry_t *fib_entry,
+				   fib_source_t source)
+{
+    if (NULL != fib_entry_src_vft[source].fesv_cover_change)
+    {
+	return (fib_entry_src_vft[source].fesv_cover_change(
+		    fib_entry_src_find(fib_entry, source, NULL),
+		    fib_entry));
+    }
+
+    fib_entry_src_cover_res_t res = {
+	.install = !0,
+	.bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
+    };
+    return (res);
+}
+
+fib_entry_src_cover_res_t
+fib_entry_src_action_cover_update (fib_entry_t *fib_entry,
+				   fib_source_t source)
+{
+    if (NULL != fib_entry_src_vft[source].fesv_cover_update)
+    {
+	return (fib_entry_src_vft[source].fesv_cover_update(
+		    fib_entry_src_find(fib_entry, source, NULL),
+		    fib_entry));
+    }
+
+    fib_entry_src_cover_res_t res = {
+	.install = !0,
+	.bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
+    };
+    return (res);
+}
+
+typedef struct fib_entry_src_collect_forwarding_ctx_t_
+{
+    load_balance_path_t * next_hops;
+    const fib_entry_t *fib_entry;
+    const fib_entry_src_t *esrc;
+    fib_forward_chain_type_t fct;
+    int is_recursive;
+} fib_entry_src_collect_forwarding_ctx_t;
+
+/**
+ * @brief Determine whether this FIB entry should use a load-balance MAP
+ * to support PIC edge fast convergence
+ */
+load_balance_flags_t
+fib_entry_calc_lb_flags (fib_entry_src_collect_forwarding_ctx_t *ctx)
+{
+    /**
+     * We'll use a LB map is the path-list has recursive paths.
+     * recursive paths implies BGP, and hence scale.
+     */
+    if (ctx->is_recursive)
+    {
+        return (LOAD_BALANCE_FLAG_USES_MAP);
+    }
+    return (LOAD_BALANCE_FLAG_NONE);
+}
+
+static int
+fib_entry_src_valid_out_label (mpls_label_t label)
+{
+    return ((MPLS_LABEL_IS_REAL(label) ||
+             MPLS_IETF_IPV4_EXPLICIT_NULL_LABEL == label ||
+             MPLS_IETF_IPV6_EXPLICIT_NULL_LABEL == label ||
+             MPLS_IETF_IMPLICIT_NULL_LABEL == label));
+}
+
+/**
+ * @brief Turn the chain type requested by the client into the one they
+ * really wanted
+ */
+fib_forward_chain_type_t
+fib_entry_chain_type_fixup (const fib_entry_t *entry,
+			    fib_forward_chain_type_t fct)
+{
+    ASSERT(FIB_FORW_CHAIN_TYPE_MPLS_EOS == fct);
+
+    /*
+     * The EOS chain is a tricky since one cannot know the adjacency
+     * to link to without knowing what the packets payload protocol
+     * will be once the label is popped.
+     */
+    fib_forward_chain_type_t dfct;
+
+    dfct = fib_entry_get_default_chain_type(entry);
+
+    if (FIB_FORW_CHAIN_TYPE_MPLS_EOS == dfct)
+    {
+        /*
+         * 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(
+                    entry->fe_prefix.fp_payload_proto));
+    }
+    /*
+     * else give them what this entry would be by default. i.e. if it's a v6
+     * entry, then the label its local labelled should be carrying v6 traffic.
+     * If it's a non-EOS label entry, then there are more labels and we want
+     * a non-eos chain.
+     */
+    return (dfct);
+}
+
+static int
+fib_entry_src_collect_forwarding (fib_node_index_t pl_index,
+                                  fib_node_index_t path_index,
+                                  void *arg)
+{
+    fib_entry_src_collect_forwarding_ctx_t *ctx;
+    fib_path_ext_t *path_ext;
+
+    ctx = arg;
+
+    /*
+     * if the path is not resolved, don't include it.
+     */
+    if (!fib_path_is_resolved(path_index))
+    {
+        return (!0);
+    }
+
+    if (fib_path_is_recursive(path_index))
+    {
+        ctx->is_recursive = 1;
+    }
+
+    /*
+     * get the matching path-extension for the path being visited.
+     */
+    vec_foreach(path_ext, ctx->esrc->fes_path_exts)
+    {
+        if (path_ext->fpe_path_index == path_index)
+            break;
+    }
+    
+    if (NULL != path_ext &&
+        path_ext->fpe_path_index == path_index &&
+        fib_entry_src_valid_out_label(path_ext->fpe_label_stack[0]))
+    {
+        /*
+         * found a matching extension. stack it to obtain the forwarding
+         * info for this path.
+         */
+        ctx->next_hops = fib_path_ext_stack(path_ext, ctx->fib_entry, ctx->fct, ctx->next_hops);
+    }
+    else
+    {
+        load_balance_path_t *nh;
+
+        /*
+         * no extension => no out-going label for this path. that's OK
+         * in the case of an IP or EOS chain, but not for non-EOS
+         */
+        switch (ctx->fct)
+        {
+        case FIB_FORW_CHAIN_TYPE_UNICAST_IP4:
+        case FIB_FORW_CHAIN_TYPE_UNICAST_IP6:
+            /*
+             * EOS traffic with no label to stack, we need the IP Adj
+             */
+            vec_add2(ctx->next_hops, nh, 1);
+
+            nh->path_index = path_index;
+            nh->path_weight = fib_path_get_weight(path_index);
+            fib_path_contribute_forwarding(path_index, ctx->fct, &nh->path_dpo);
+
+            break;
+        case FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS:
+	    if (fib_path_is_exclusive(path_index) ||
+		fib_path_is_deag(path_index))
+	    {
+		vec_add2(ctx->next_hops, nh, 1);
+
+		nh->path_index = path_index;
+		nh->path_weight = fib_path_get_weight(path_index);
+		fib_path_contribute_forwarding(path_index,
+					       FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS,
+					       &nh->path_dpo);
+	    }
+            break;
+        case FIB_FORW_CHAIN_TYPE_MPLS_EOS:
+        {
+            /*
+             * no label. we need a chain based on the payload. fixup.
+             */
+            vec_add2(ctx->next_hops, nh, 1);
+
+            nh->path_index = path_index;
+            nh->path_weight = fib_path_get_weight(path_index);
+            fib_path_contribute_forwarding(path_index,
+                                           fib_entry_chain_type_fixup(ctx->fib_entry,
+                                                                      ctx->fct),
+                                           &nh->path_dpo);
+
+            break;
+        }
+        case FIB_FORW_CHAIN_TYPE_ETHERNET:
+	    ASSERT(0);
+	    break;
+        }
+    }
+
+    return (!0);
+}
+
+void
+fib_entry_src_mk_lb (fib_entry_t *fib_entry,
+		     const fib_entry_src_t *esrc,
+		     fib_forward_chain_type_t fct,
+		     dpo_id_t *dpo_lb)
+{
+    dpo_proto_t lb_proto;
+
+    /*
+     * If the entry has path extensions then we construct a load-balance
+     * by stacking the extensions on the forwarding chains of the paths.
+     * Otherwise we use the load-balance of the path-list
+     */
+    fib_entry_src_collect_forwarding_ctx_t ctx = {
+        .esrc = esrc,
+        .fib_entry = fib_entry,
+        .next_hops = NULL,
+        .is_recursive = 0,
+        .fct = fct,
+    };
+
+    lb_proto = fib_proto_to_dpo(fib_entry->fe_prefix.fp_proto);
+
+    fib_path_list_walk(esrc->fes_pl,
+                       fib_entry_src_collect_forwarding,
+                       &ctx);
+
+    if (esrc->fes_entry_flags & FIB_ENTRY_FLAG_EXCLUSIVE)
+    {
+	/*
+	 * the client provided the DPO that the entry should link to.
+	 * all entries must link to a LB, so if it is an LB already
+	 * then we can use it.
+	 */
+	if ((1 == vec_len(ctx.next_hops)) &&
+	    (DPO_LOAD_BALANCE == ctx.next_hops[0].path_dpo.dpoi_type))
+	{
+	    dpo_copy(dpo_lb, &ctx.next_hops[0].path_dpo);
+	    dpo_reset(&ctx.next_hops[0].path_dpo);
+	    return;
+	}
+    }
+
+    if (!dpo_id_is_valid(dpo_lb))
+    {
+        /*
+         * first time create
+         */
+        flow_hash_config_t fhc;
+
+        fhc = fib_table_get_flow_hash_config(fib_entry->fe_fib_index,
+                                             dpo_proto_to_fib(lb_proto));
+        dpo_set(dpo_lb,
+                DPO_LOAD_BALANCE,
+                lb_proto,
+                load_balance_create(0, lb_proto, fhc));
+    }
+
+    load_balance_multipath_update(dpo_lb,
+                                  ctx.next_hops,
+                                  fib_entry_calc_lb_flags(&ctx));
+    vec_free(ctx.next_hops);
+
+    /*
+     * if this entry is sourced by the uRPF-exempt source then we
+     * append the always present local0 interface (index 0) to the
+     * uRPF list so it is not empty. that way packets pass the loose check.
+     */
+    index_t ui = fib_path_list_get_urpf(esrc->fes_pl);
+
+    if (fib_entry_is_sourced(fib_entry_get_index(fib_entry),
+			     FIB_SOURCE_URPF_EXEMPT) &&
+	(0 == fib_urpf_check_size(ui)))
+    {
+	/*
+	 * The uRPF list we get from the path-list is shared by all
+	 * other users of the list, but the uRPF exemption applies
+	 * only to this prefix. So we need our own list.
+	 */
+	ui = fib_urpf_list_alloc_and_lock();
+	fib_urpf_list_append(ui, 0);
+	fib_urpf_list_bake(ui);
+	load_balance_set_urpf(dpo_lb->dpoi_index, ui);
+	fib_urpf_list_unlock(ui);
+    }
+    else
+    {
+	load_balance_set_urpf(dpo_lb->dpoi_index, ui);
+    }
+}
+
+void
+fib_entry_src_action_install (fib_entry_t *fib_entry,
+			      fib_source_t source)
+{
+    /*
+     * Install the forwarding chain for the given source into the forwarding
+     * tables
+     */
+    fib_forward_chain_type_t fct;
+    fib_entry_src_t *esrc;
+    int insert;
+
+    fct = fib_entry_get_default_chain_type(fib_entry);
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    /*
+     * Every entry has its own load-balance object. All changes to the entry's
+     * forwarding result in an inplace modify of the load-balance. This means
+     * the load-balance object only needs to be added to the forwarding
+     * DB once, when it is created.
+     */
+    insert = !dpo_id_is_valid(&fib_entry->fe_lb);
+
+    fib_entry_src_mk_lb(fib_entry, esrc, fct, &fib_entry->fe_lb);
+
+    ASSERT(dpo_id_is_valid(&fib_entry->fe_lb));
+    FIB_ENTRY_DBG(fib_entry, "install: %d", fib_entry->fe_lb);
+
+    /*
+     * insert the adj into the data-plane forwarding trie
+     */
+    if (insert)
+    {
+       fib_table_fwding_dpo_update(fib_entry->fe_fib_index,
+                                   &fib_entry->fe_prefix,
+                                   &fib_entry->fe_lb);
+    }
+
+    /*
+     * if any of the other chain types are already created they will need
+     * updating too
+     */
+    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, esrc,
+                            fib_entry_delegate_type_to_chain_type(fdt),
+                            &fed->fd_dpo);
+    });
+}
+
+void
+fib_entry_src_action_uninstall (fib_entry_t *fib_entry)
+{
+    /*
+     * uninstall the forwarding chain from the forwarding tables
+     */
+    FIB_ENTRY_DBG(fib_entry, "uninstall: %d",
+		  fib_entry->fe_adj_index);
+
+    if (dpo_id_is_valid(&fib_entry->fe_lb))
+    {
+	fib_table_fwding_dpo_remove(
+	    fib_entry->fe_fib_index,
+	    &fib_entry->fe_prefix,
+	    &fib_entry->fe_lb);
+
+	dpo_reset(&fib_entry->fe_lb);
+    }
+}
+
+static void
+fib_entry_recursive_loop_detect_i (fib_node_index_t path_list_index)
+{
+    fib_node_index_t *entries = NULL;
+
+    fib_path_list_recursive_loop_detect(path_list_index, &entries);
+
+    vec_free(entries);
+}
+
+void
+fib_entry_src_action_activate (fib_entry_t *fib_entry,
+			       fib_source_t source)
+
+{
+    int houston_we_are_go_for_install;
+    fib_entry_src_t *esrc;
+
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    ASSERT(!(esrc->fes_flags & FIB_ENTRY_SRC_FLAG_ACTIVE));
+    ASSERT(esrc->fes_flags & FIB_ENTRY_SRC_FLAG_ADDED);
+
+    esrc->fes_flags |= FIB_ENTRY_SRC_FLAG_ACTIVE;
+
+    if (NULL != fib_entry_src_vft[source].fesv_activate)
+    {
+	houston_we_are_go_for_install =
+	    fib_entry_src_vft[source].fesv_activate(esrc, fib_entry);
+    }
+    else
+    {
+	/*
+	 * the source is not providing an activate function, we'll assume
+	 * therefore it has no objection to installing the entry
+	 */
+	houston_we_are_go_for_install = !0;
+    }
+
+    /*
+     * link to the path-list provided by the source, and go check
+     * if that forms any loops in the graph.
+     */
+    fib_entry->fe_parent = esrc->fes_pl;
+    fib_entry->fe_sibling =
+	fib_path_list_child_add(fib_entry->fe_parent,
+				FIB_NODE_TYPE_ENTRY,
+				fib_entry_get_index(fib_entry));
+
+    fib_entry_recursive_loop_detect_i(fib_entry->fe_parent);
+
+    FIB_ENTRY_DBG(fib_entry, "activate: %d",
+		  fib_entry->fe_parent);
+
+    if (0 != houston_we_are_go_for_install)
+    {
+	fib_entry_src_action_install(fib_entry, source);
+    }
+    else
+    {
+	fib_entry_src_action_uninstall(fib_entry);
+    }
+}
+
+void
+fib_entry_src_action_deactivate (fib_entry_t *fib_entry,
+				 fib_source_t source)
+
+{
+    fib_node_index_t path_list_index;
+    fib_entry_src_t *esrc;
+
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    ASSERT(esrc->fes_flags & FIB_ENTRY_SRC_FLAG_ACTIVE);
+
+    if (NULL != fib_entry_src_vft[source].fesv_deactivate)
+    {
+	fib_entry_src_vft[source].fesv_deactivate(esrc, fib_entry);
+    }
+
+    esrc->fes_flags &= ~FIB_ENTRY_SRC_FLAG_ACTIVE;
+
+    FIB_ENTRY_DBG(fib_entry, "deactivate: %d", fib_entry->fe_parent);
+
+    /*
+     * un-link from an old path-list. Check for any loops this will clear
+     */
+    path_list_index = fib_entry->fe_parent;
+    fib_entry->fe_parent = FIB_NODE_INDEX_INVALID;
+
+    fib_entry_recursive_loop_detect_i(path_list_index);
+
+    /*
+     * this will unlock the path-list, so it may be invalid thereafter.
+     */
+    fib_path_list_child_remove(path_list_index, fib_entry->fe_sibling);
+    fib_entry->fe_sibling = FIB_NODE_INDEX_INVALID;
+}
+
+static void
+fib_entry_src_action_fwd_update (const fib_entry_t *fib_entry,
+				 fib_source_t source)
+{
+    fib_entry_src_t *esrc;
+
+    vec_foreach(esrc, fib_entry->fe_srcs)
+    {
+	if (NULL != fib_entry_src_vft[esrc->fes_src].fesv_fwd_update)
+	{
+	    fib_entry_src_vft[esrc->fes_src].fesv_fwd_update(esrc,
+							     fib_entry,
+							     source);
+	}
+    }
+}
+
+void
+fib_entry_src_action_reactivate (fib_entry_t *fib_entry,
+				 fib_source_t source)
+{
+    fib_node_index_t path_list_index;
+    fib_entry_src_t *esrc;
+
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    ASSERT(esrc->fes_flags & FIB_ENTRY_SRC_FLAG_ACTIVE);
+
+    FIB_ENTRY_DBG(fib_entry, "reactivate: %d to %d",
+		  fib_entry->fe_parent,
+		  esrc->fes_pl);
+
+    if (fib_entry->fe_parent != esrc->fes_pl)
+    {
+	/*
+	 * un-link from an old path-list. Check for any loops this will clear
+	 */
+	path_list_index = fib_entry->fe_parent;
+	fib_entry->fe_parent = FIB_NODE_INDEX_INVALID;
+
+	/*
+	 * temporary lock so it doesn't get deleted when this entry is no
+	 * longer a child.
+	 */
+	fib_path_list_lock(path_list_index);
+
+	/*
+	 * this entry is no longer a child. after unlinking check if any loops
+	 * were broken
+	 */
+	fib_path_list_child_remove(path_list_index,
+				   fib_entry->fe_sibling);
+
+	fib_entry_recursive_loop_detect_i(path_list_index);
+
+	/*
+	 * link to the path-list provided by the source, and go check
+	 * if that forms any loops in the graph.
+	 */
+	fib_entry->fe_parent = esrc->fes_pl;
+	fib_entry->fe_sibling =
+	    fib_path_list_child_add(fib_entry->fe_parent,
+				    FIB_NODE_TYPE_ENTRY,
+				    fib_entry_get_index(fib_entry));
+
+	fib_entry_recursive_loop_detect_i(fib_entry->fe_parent);
+	fib_path_list_unlock(path_list_index);
+    }
+    fib_entry_src_action_install(fib_entry, source);
+    fib_entry_src_action_fwd_update(fib_entry, source);
+}
+
+void
+fib_entry_src_action_installed (const fib_entry_t *fib_entry,
+				fib_source_t source)
+{
+    fib_entry_src_t *esrc;
+
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    if (NULL != fib_entry_src_vft[source].fesv_installed)
+    {
+	fib_entry_src_vft[source].fesv_installed(esrc,
+						 fib_entry);
+    }
+
+    fib_entry_src_action_fwd_update(fib_entry, source);
+}
+
+/*
+ * fib_entry_src_action_add
+ *
+ * Adding a source can result in a new fib_entry being created, which
+ * can inturn mean the pool is realloc'd and thus the entry passed as
+ * an argument it also realloc'd
+ * @return the original entry
+ */
+fib_entry_t *
+fib_entry_src_action_add (fib_entry_t *fib_entry,
+			  fib_source_t source,
+			  fib_entry_flag_t flags,
+			  const dpo_id_t *dpo)
+{
+    fib_node_index_t fib_entry_index;
+    fib_entry_src_t *esrc;
+
+    esrc = fib_entry_src_find_or_create(fib_entry, source, NULL);
+
+    esrc->fes_ref_count++;
+
+    if (1 != esrc->fes_ref_count)
+    {
+        /*
+         * we only want to add the source on the 0->1 transition
+         */
+        return (fib_entry);
+    }
+
+    esrc->fes_entry_flags = flags;
+
+    /*
+     * save variable so we can recover from a fib_entry realloc.
+     */
+    fib_entry_index = fib_entry_get_index(fib_entry);
+
+    if (NULL != fib_entry_src_vft[source].fesv_add)
+    {
+	fib_entry_src_vft[source].fesv_add(esrc,
+					   fib_entry,
+					   flags,
+					   fib_entry_get_proto(fib_entry),
+					   dpo);
+    }
+
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    esrc->fes_flags |= FIB_ENTRY_SRC_FLAG_ADDED;
+
+    fib_path_list_lock(esrc->fes_pl);
+
+    /*
+     * the source owns a lock on the entry
+     */
+    fib_entry_lock(fib_entry_get_index(fib_entry));
+
+    return (fib_entry);
+}
+
+/*
+ * fib_entry_src_action_update
+ *
+ * Adding a source can result in a new fib_entry being created, which
+ * can inturn mean the pool is realloc'd and thus the entry passed as
+ * an argument it also realloc'd
+ * @return the original entry
+ */
+fib_entry_t *
+fib_entry_src_action_update (fib_entry_t *fib_entry,
+			     fib_source_t source,
+			     fib_entry_flag_t flags,
+			     const dpo_id_t *dpo)
+{
+    fib_node_index_t fib_entry_index, old_path_list_index;
+    fib_entry_src_t *esrc;
+
+    esrc = fib_entry_src_find_or_create(fib_entry, source, NULL);
+
+    if (NULL == esrc)
+	return (fib_entry_src_action_add(fib_entry, source, flags, dpo));
+
+    old_path_list_index = esrc->fes_pl;
+    esrc->fes_entry_flags = flags;
+
+    /*
+     * save variable so we can recover from a fib_entry realloc.
+     */
+    fib_entry_index = fib_entry_get_index(fib_entry);
+
+    if (NULL != fib_entry_src_vft[source].fesv_add)
+    {
+	fib_entry_src_vft[source].fesv_add(esrc,
+					   fib_entry,
+					   flags,
+					   fib_entry_get_proto(fib_entry),
+					   dpo);
+    }
+
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    esrc->fes_flags |= FIB_ENTRY_SRC_FLAG_ADDED;
+
+    fib_path_list_lock(esrc->fes_pl);
+    fib_path_list_unlock(old_path_list_index);
+
+    return (fib_entry);
+}
+
+
+fib_entry_src_flag_t
+fib_entry_src_action_remove (fib_entry_t *fib_entry,
+			     fib_source_t source)
+
+{
+    fib_node_index_t old_path_list;
+    fib_entry_src_flag_t sflags;
+    fib_entry_src_t *esrc;
+
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    if (NULL == esrc)
+	return (FIB_ENTRY_SRC_FLAG_ACTIVE);
+
+    esrc->fes_ref_count--;
+    sflags = esrc->fes_flags;
+
+    if (0 != esrc->fes_ref_count)
+    {
+        /*
+         * only remove the source on the 1->0 transisition
+         */
+        return (sflags);
+    }
+
+    if (esrc->fes_flags & FIB_ENTRY_SRC_FLAG_ACTIVE)
+    {
+	fib_entry_src_action_deactivate(fib_entry, source);
+    }
+
+    old_path_list = esrc->fes_pl;
+
+    if (NULL != fib_entry_src_vft[source].fesv_remove)
+    {
+	fib_entry_src_vft[source].fesv_remove(esrc);
+    }
+
+    fib_path_list_unlock(old_path_list);
+    fib_entry_unlock(fib_entry_get_index(fib_entry));
+
+    sflags &= ~FIB_ENTRY_SRC_FLAG_ADDED;
+    fib_entry_src_action_deinit(fib_entry, source);
+
+    return (sflags);
+}
+
+static inline int
+fib_route_recurses_via_self (const fib_prefix_t *prefix,
+			     const fib_route_path_t *rpath)
+{
+    /*
+     * not all zeros next hop &&
+     * is recursive path &&
+     * nexthop is same as the route's address
+     */
+    return ((!ip46_address_is_zero(&rpath->frp_addr)) &&
+	    (~0 == rpath->frp_sw_if_index) &&
+	    (0 == ip46_address_cmp(&rpath->frp_addr, &prefix->fp_addr)));
+
+}
+
+/*
+ * fib_route_attached_cross_table
+ *
+ * Return true the the route is attached via an interface that
+ * is not in the same table as the route
+ */
+static inline int
+fib_route_attached_cross_table (const fib_entry_t *fib_entry,
+				const fib_route_path_t *rpath)
+{
+    /*
+     * - All zeros next-hop
+     * - a valid interface
+     * - entry's fib index not equeal to interface's index
+     */
+    if (ip46_address_is_zero(&rpath->frp_addr) &&
+	(~0 != rpath->frp_sw_if_index) &&
+	(fib_entry->fe_fib_index != 
+	 fib_table_get_index_for_sw_if_index(fib_entry_get_proto(fib_entry),
+					     rpath->frp_sw_if_index)))
+    {
+	return (!0);
+    }
+    return (0);
+}
+
+/*
+ * fib_route_attached_cross_table
+ *
+ * Return true the the route is attached via an interface that
+ * is not in the same table as the route
+ */
+static inline int
+fib_path_is_attached (const fib_route_path_t *rpath)
+{
+    /*
+     * - All zeros next-hop
+     * - a valid interface
+     */
+    if (ip46_address_is_zero(&rpath->frp_addr) &&
+	(~0 != rpath->frp_sw_if_index))
+    {
+	return (!0);
+    }
+    return (0);
+}
+
+fib_path_list_flags_t
+fib_entry_src_flags_2_path_list_flags (fib_entry_flag_t eflags)
+{
+    fib_path_list_flags_t plf = FIB_PATH_LIST_FLAG_NONE;
+
+    if (eflags & FIB_ENTRY_FLAG_DROP)
+    {
+	plf |= FIB_PATH_LIST_FLAG_DROP;
+    }
+    if (eflags & FIB_ENTRY_FLAG_LOCAL)
+    {
+	plf |= FIB_PATH_LIST_FLAG_LOCAL;
+    }
+    if (eflags & FIB_ENTRY_FLAG_EXCLUSIVE)
+    {
+	plf |= FIB_PATH_LIST_FLAG_EXCLUSIVE;
+    }
+
+    return (plf);
+}
+
+static void
+fib_entry_flags_update (const fib_entry_t *fib_entry,
+			const fib_route_path_t *rpath,
+			fib_path_list_flags_t *pl_flags,
+			fib_entry_src_t *esrc)
+{
+    /*
+     * don't allow the addition of a recursive looped path for prefix
+     * via itself.
+     */
+    if (fib_route_recurses_via_self(&fib_entry->fe_prefix, rpath))	
+    {
+	/*
+	 * force the install of a drop path-list.
+	 * we want the entry to have some path-list, mainly so
+	 * the dodgy path can be rmeoved when the source stops playing
+	 * silly buggers.
+	 */
+	*pl_flags |= FIB_PATH_LIST_FLAG_DROP;
+    }
+    else
+    {
+	*pl_flags &= ~FIB_PATH_LIST_FLAG_DROP;
+    }
+
+    if ((esrc->fes_src == FIB_SOURCE_API) ||
+	(esrc->fes_src == FIB_SOURCE_CLI))
+    {
+	if (fib_path_is_attached(rpath))
+	{
+	    esrc->fes_entry_flags |= FIB_ENTRY_FLAG_ATTACHED;
+	}
+	else
+	{
+	    esrc->fes_entry_flags &= ~FIB_ENTRY_FLAG_ATTACHED;
+	}
+    }
+    if (fib_route_attached_cross_table(fib_entry, rpath))
+    {
+	esrc->fes_entry_flags |= FIB_ENTRY_FLAG_IMPORT;
+    }
+    else
+    {
+	esrc->fes_entry_flags &= ~FIB_ENTRY_FLAG_IMPORT;
+    }
+}
+
+/*
+ * fib_entry_src_path_ext_add
+ *
+ * append a path extension to the entry's list
+ */
+static void
+fib_entry_src_path_ext_append (fib_entry_src_t *esrc,
+			       const fib_route_path_t *rpath)
+{
+    if (NULL != rpath->frp_label_stack)
+    {
+	fib_path_ext_t *path_ext;
+
+	vec_add2(esrc->fes_path_exts, path_ext, 1);
+
+	fib_path_ext_init(path_ext, esrc->fes_pl, rpath);
+    }
+}
+
+/*
+ * fib_entry_src_path_ext_insert
+ *
+ * insert, sorted, a path extension to the entry's list.
+ * It's not strictly necessary in sort the path extensions, since each
+ * extension has the path index to which it resolves. However, by being
+ * sorted the load-balance produced has a deterministic order, not an order
+ * based on the sequence of extension additions. this is a considerable benefit.
+ */
+static void
+fib_entry_src_path_ext_insert (fib_entry_src_t *esrc,
+			       const fib_route_path_t *rpath)
+{
+    if (0 == vec_len(esrc->fes_path_exts))
+	return (fib_entry_src_path_ext_append(esrc, rpath));
+
+    if (NULL != rpath->frp_label_stack)
+    {
+	fib_path_ext_t path_ext;
+	int i = 0;
+
+	fib_path_ext_init(&path_ext, esrc->fes_pl, rpath);
+
+	while (i < vec_len(esrc->fes_path_exts) &&
+	       (fib_path_ext_cmp(&esrc->fes_path_exts[i], rpath) < 0))
+	{
+	    i++;
+	}
+
+	vec_insert_elts(esrc->fes_path_exts, &path_ext, 1, i);
+    }
+}
+
+/*
+ * fib_entry_src_action_add
+ *
+ * Adding a source can result in a new fib_entry being created, which
+ * can inturn mean the pool is realloc'd and thus the entry passed as
+ * an argument it also realloc'd
+ * @return the entry
+ */
+fib_entry_t*
+fib_entry_src_action_path_add (fib_entry_t *fib_entry,
+			       fib_source_t source,
+			       fib_entry_flag_t flags,
+			       const fib_route_path_t *rpath)
+{
+    fib_node_index_t old_path_list, fib_entry_index;
+    fib_path_list_flags_t pl_flags;
+    fib_path_ext_t *path_ext;
+    fib_entry_src_t *esrc;
+
+    /*
+     * save variable so we can recover from a fib_entry realloc.
+     */
+    fib_entry_index = fib_entry_get_index(fib_entry);
+
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+    if (NULL == esrc)
+    {
+	fib_entry =
+            fib_entry_src_action_add(fib_entry,
+                                     source,
+                                     flags,
+                                     drop_dpo_get(
+                                         fib_proto_to_dpo(
+                                             fib_entry_get_proto(fib_entry))));
+	esrc = fib_entry_src_find(fib_entry, source, NULL);
+    }
+
+    /*
+     * we are no doubt modifying a path-list. If the path-list
+     * is shared, and hence not modifiable, then the index returned
+     * will be for a different path-list. This FIB entry to needs
+     * to maintain its lock appropriately.
+     */
+    old_path_list = esrc->fes_pl;
+
+    ASSERT(NULL != fib_entry_src_vft[source].fesv_path_add);
+
+    pl_flags = fib_entry_src_flags_2_path_list_flags(fib_entry_get_flags_i(fib_entry));
+    fib_entry_flags_update(fib_entry, rpath, &pl_flags, esrc);
+
+    fib_entry_src_vft[source].fesv_path_add(esrc, fib_entry, pl_flags, rpath);
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    /*
+     * re-resolve all the path-extensions with the new path-list
+     */
+    vec_foreach(path_ext, esrc->fes_path_exts)
+    {
+	fib_path_ext_resolve(path_ext, esrc->fes_pl);
+    }
+    /*
+     * if the path has a label we need to add a path extension
+     */
+    fib_entry_src_path_ext_insert(esrc, rpath);
+
+    fib_path_list_lock(esrc->fes_pl);
+    fib_path_list_unlock(old_path_list);
+
+    return (fib_entry);
+}
+
+/*
+ * fib_entry_src_action_swap
+ *
+ * The source is providing new paths to replace the old ones.
+ * Adding a source can result in a new fib_entry being created, which
+ * can inturn mean the pool is realloc'd and thus the entry passed as
+ * an argument it also realloc'd
+ * @return the entry
+ */
+fib_entry_t*
+fib_entry_src_action_path_swap (fib_entry_t *fib_entry,
+				fib_source_t source,
+				fib_entry_flag_t flags,				
+				const fib_route_path_t *rpaths)
+{
+    fib_node_index_t old_path_list, fib_entry_index;
+    fib_path_list_flags_t pl_flags;
+    const fib_route_path_t *rpath;
+    fib_path_ext_t *path_ext;
+    fib_entry_src_t *esrc;
+
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    /*
+     * save variable so we can recover from a fib_entry realloc.
+     */
+    fib_entry_index = fib_entry_get_index(fib_entry);
+
+    if (NULL == esrc)
+    {
+	fib_entry = fib_entry_src_action_add(fib_entry,
+					     source,
+					     flags,
+                                             drop_dpo_get(
+                                                 fib_proto_to_dpo(
+                                                     fib_entry_get_proto(fib_entry))));
+	esrc = fib_entry_src_find(fib_entry, source, NULL);
+    }
+
+    /*
+     * swapping paths may create a new path-list (or may use an existing shared)
+     * but we are certainly getting a different one. This FIB entry to needs
+     * to maintain its lock appropriately.
+     */
+    old_path_list = esrc->fes_pl;
+
+    ASSERT(NULL != fib_entry_src_vft[source].fesv_path_swap);
+
+    pl_flags = fib_entry_src_flags_2_path_list_flags(flags);
+
+    vec_foreach(rpath, rpaths)
+    {
+	fib_entry_flags_update(fib_entry, rpath, &pl_flags, esrc);
+    }
+
+    fib_entry_src_vft[source].fesv_path_swap(esrc,
+					     fib_entry,
+					     pl_flags,
+					     rpaths);
+
+    vec_foreach(path_ext, esrc->fes_path_exts)
+    {
+	vec_free(path_ext->fpe_label_stack);
+    }
+    vec_free(esrc->fes_path_exts);
+
+    vec_foreach(rpath, rpaths)
+    {
+	fib_entry_src_path_ext_append(esrc, rpath);
+    }
+
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    fib_path_list_lock(esrc->fes_pl);
+    fib_path_list_unlock(old_path_list);
+
+    return (fib_entry);
+}
+
+fib_entry_src_flag_t
+fib_entry_src_action_path_remove (fib_entry_t *fib_entry,
+				  fib_source_t source,
+				  const fib_route_path_t *rpath)
+{
+    fib_path_list_flags_t pl_flags;
+    fib_node_index_t old_path_list;
+    fib_path_ext_t *path_ext;
+    fib_entry_src_t *esrc;
+
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    ASSERT(NULL != esrc);
+    ASSERT(esrc->fes_flags & FIB_ENTRY_SRC_FLAG_ADDED);
+
+    /*
+     * we no doubt modifying a path-list. If the path-list
+     * is shared, and hence not modifiable, then the index returned
+     * will be for a different path-list. This FIB entry to needs
+     * to maintain its lock appropriately.
+     */
+    old_path_list = esrc->fes_pl;
+
+    ASSERT(NULL != fib_entry_src_vft[source].fesv_path_remove);
+
+    pl_flags = fib_entry_src_flags_2_path_list_flags(fib_entry_get_flags_i(fib_entry));
+    fib_entry_flags_update(fib_entry, rpath, &pl_flags, esrc);
+
+    fib_entry_src_vft[source].fesv_path_remove(esrc, pl_flags, rpath);
+    /*
+     * find the matching path extension and remove it
+     */
+    vec_foreach(path_ext, esrc->fes_path_exts)
+    {
+	if (!fib_path_ext_cmp(path_ext, rpath))
+	{
+	    /*
+	     * delete the element moving the remaining elements down 1 position.
+	     * this preserves the sorted order.
+	     */
+	    vec_free(path_ext->fpe_label_stack);
+	    vec_delete(esrc->fes_path_exts, 1, (path_ext - esrc->fes_path_exts));
+	    break;
+	}
+    }
+    /*
+     * re-resolve all the path-extensions with the new path-list
+     */
+    vec_foreach(path_ext, esrc->fes_path_exts)
+    {
+	fib_path_ext_resolve(path_ext, esrc->fes_pl);
+    }
+
+    /*
+     * lock the new path-list, unlock the old if it had one
+     */
+    fib_path_list_unlock(old_path_list);
+
+    if (FIB_NODE_INDEX_INVALID != esrc->fes_pl) {
+	fib_path_list_lock(esrc->fes_pl);
+	return (FIB_ENTRY_SRC_FLAG_ADDED);
+    }
+    else
+    {
+	/*
+	 * no more paths left from this source
+	 */
+	fib_entry_src_action_remove(fib_entry, source);
+	return (FIB_ENTRY_SRC_FLAG_NONE);
+    }
+}
+
+u8*
+fib_entry_src_format (fib_entry_t *fib_entry,
+		      fib_source_t source,
+		      u8* s)
+{
+    fib_entry_src_t *esrc;
+
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    if (NULL != fib_entry_src_vft[source].fesv_format)
+    {
+	return (fib_entry_src_vft[source].fesv_format(esrc, s));
+    }
+    return (s);
+}
+
+adj_index_t
+fib_entry_get_adj_for_source (fib_node_index_t fib_entry_index,
+			      fib_source_t source)
+{
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *esrc;
+
+    if (FIB_NODE_INDEX_INVALID == fib_entry_index)
+	return (ADJ_INDEX_INVALID);
+
+    fib_entry = fib_entry_get(fib_entry_index);
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    if (NULL != esrc)
+    {
+	if (FIB_NODE_INDEX_INVALID != esrc->fes_pl)
+	{
+	    return (fib_path_list_get_adj(
+			esrc->fes_pl,
+			fib_entry_get_default_chain_type(fib_entry)));
+	}
+    }
+    return (ADJ_INDEX_INVALID);
+}
+
+const int
+fib_entry_get_dpo_for_source (fib_node_index_t fib_entry_index,
+			      fib_source_t source,
+			      dpo_id_t *dpo)
+{
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *esrc;
+
+    if (FIB_NODE_INDEX_INVALID == fib_entry_index)
+	return (0);
+
+    fib_entry = fib_entry_get(fib_entry_index);
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    if (NULL != esrc)
+    {
+	if (FIB_NODE_INDEX_INVALID != esrc->fes_pl)
+	{
+	    fib_path_list_contribute_forwarding(
+		esrc->fes_pl,
+		fib_entry_get_default_chain_type(fib_entry),
+		dpo);
+
+	    return (dpo_id_is_valid(dpo));
+	}
+    }
+    return (0);
+}
+
+u32
+fib_entry_get_resolving_interface_for_source (fib_node_index_t entry_index,
+					      fib_source_t source)
+{
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *esrc;
+
+    fib_entry = fib_entry_get(entry_index);
+
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    if (NULL != esrc)
+    {
+	if (FIB_NODE_INDEX_INVALID != esrc->fes_pl)
+	{
+	    return (fib_path_list_get_resolving_interface(esrc->fes_pl));
+	}
+    }
+    return (~0);
+}
+
+fib_entry_flag_t
+fib_entry_get_flags_for_source (fib_node_index_t entry_index,
+				fib_source_t source)
+{
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *esrc;
+
+    fib_entry = fib_entry_get(entry_index);
+
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    if (NULL != esrc)
+    {
+	return (esrc->fes_entry_flags);
+    }
+
+    return (FIB_ENTRY_FLAG_NONE);
+}
+
+fib_entry_flag_t
+fib_entry_get_flags_i (const fib_entry_t *fib_entry)
+{
+    fib_entry_flag_t flags;
+
+    /*
+     * the vector of sources is deliberately arranged in priority order
+     */
+    if (0 == vec_len(fib_entry->fe_srcs))
+    {
+	flags = FIB_ENTRY_FLAG_NONE;
+    }
+    else
+    {
+	fib_entry_src_t *esrc;
+
+	esrc = vec_elt_at_index(fib_entry->fe_srcs, 0);
+	flags = esrc->fes_entry_flags;
+    }
+
+    return (flags);
+}
+
+void
+fib_entry_set_source_data (fib_node_index_t fib_entry_index,
+                           fib_source_t source,
+                           const void *data)
+{
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *esrc;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    if (NULL != esrc &&
+        NULL != fib_entry_src_vft[source].fesv_set_data)
+    {
+	fib_entry_src_vft[source].fesv_set_data(esrc, fib_entry, data);
+    }
+}
+
+const void*
+fib_entry_get_source_data (fib_node_index_t fib_entry_index,
+                           fib_source_t source)
+{
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *esrc;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    if (NULL != esrc &&
+        NULL != fib_entry_src_vft[source].fesv_get_data)
+    {
+	return (fib_entry_src_vft[source].fesv_get_data(esrc, fib_entry));
+    }
+    return (NULL);
+}
+
+void
+fib_entry_src_module_init (void)
+{
+    fib_entry_src_rr_register();
+    fib_entry_src_interface_register();
+    fib_entry_src_default_route_register();
+    fib_entry_src_special_register();
+    fib_entry_src_api_register();
+    fib_entry_src_adj_register();
+    fib_entry_src_mpls_register();
+    fib_entry_src_lisp_register();
+}