1 files changed, 293 insertions, 0 deletions

diff --git a/src/vnet/fib/fib_entry_src_rr.c b/src/vnet/fib/fib_entry_src_rr.c
new file mode 100644
index 00000000000..ff15c54e281
--- /dev/null
+++ b/src/vnet/fib/fib_entry_src_rr.c
@@ -0,0 +1,293 @@
+/*
+ * 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/drop_dpo.h>
+
+#include "fib_entry_src.h"
+#include "fib_entry_cover.h"
+#include "fib_entry.h"
+#include "fib_table.h"
+
+/*
+ * fib_entry_src_rr_resolve_via_connected
+ *
+ * Resolve via a connected cover.
+ */
+static void
+fib_entry_src_rr_resolve_via_connected (fib_entry_src_t *src,
+					const fib_entry_t *fib_entry,
+					const fib_entry_t *cover)
+{
+    const fib_route_path_t path = {
+	.frp_proto = fib_entry->fe_prefix.fp_proto,
+	.frp_addr = fib_entry->fe_prefix.fp_addr,
+	.frp_sw_if_index = fib_entry_get_resolving_interface(
+	                       fib_entry_get_index(cover)),
+	.frp_fib_index = ~0,
+	.frp_weight = 1,
+    };
+    fib_route_path_t *paths = NULL;
+    vec_add1(paths, path);
+
+    /*
+     * since the cover is connected, the address this entry corresponds
+     * to is a peer (ARP-able for) on the interface to which the cover is
+     * connected. The fact we resolve via the cover, just means this RR
+     * source is the first SRC to use said peer. The ARP source will be along
+     * shortly to over-rule this RR source.
+     */
+    src->fes_pl = fib_path_list_create(FIB_PATH_LIST_FLAG_NONE, paths);
+    src->fes_entry_flags = fib_entry_get_flags(fib_entry_get_index(cover));
+
+    vec_free(paths);
+}
+
+
+/**
+ * Source initialisation Function 
+ */
+static void
+fib_entry_src_rr_init (fib_entry_src_t *src)
+{
+    src->rr.fesr_cover = FIB_NODE_INDEX_INVALID;
+    src->rr.fesr_sibling = FIB_NODE_INDEX_INVALID;
+}
+
+/*
+ * Source activation. Called when the source is the new best source on the entry
+ */
+static int
+fib_entry_src_rr_activate (fib_entry_src_t *src,
+			   const fib_entry_t *fib_entry)
+{
+    fib_entry_t *cover;
+
+    /*
+     * find the covering prefix. become a dependent thereof.
+     * for IP there should always be a cover, though it may be the default route.
+     * For MPLS there is never a cover.
+     */
+    if (FIB_PROTOCOL_MPLS == fib_entry->fe_prefix.fp_proto)
+    {
+	src->fes_pl = fib_path_list_create_special(FIB_PROTOCOL_MPLS,
+						   FIB_PATH_LIST_FLAG_DROP,
+						   NULL);
+	fib_path_list_lock(src->fes_pl);
+	return (!0);
+    }
+
+    src->rr.fesr_cover = fib_table_get_less_specific(fib_entry->fe_fib_index,
+						     &fib_entry->fe_prefix);
+
+    ASSERT(FIB_NODE_INDEX_INVALID != src->rr.fesr_cover);
+
+    cover = fib_entry_get(src->rr.fesr_cover);
+
+    src->rr.fesr_sibling =
+	fib_entry_cover_track(cover, fib_entry_get_index(fib_entry));
+
+    /*
+     * if the ocver is attached then install an attached-host path
+     * (like an adj-fib). Otherwise inherit the forwarding from the cover
+     */
+    if (FIB_ENTRY_FLAG_ATTACHED & fib_entry_get_flags_i(cover))
+    {
+	fib_entry_src_rr_resolve_via_connected(src, fib_entry, cover);
+    }
+    else
+    {
+        /*
+         * use the path-list of the cover, unless it would form a loop.
+         * that is unless the cover is via this entry.
+         * If a loop were to form it would be a 1 level loop (i.e. X via X),
+         * and there would be 2 locks on the path-list; one since its used
+         * by the cover, and 1 from here. The first lock will go when the
+         * cover is removed, the second, and last, when the covered walk
+         * occurs during the cover's removel - this is not a place where
+         * we can handle last lock gone.
+         * In short, don't let the loop form. The usual rules of 'we must
+         * let it form so we know when it breaks' don't apply here, since
+         * the loop will break when the cover changes, and this function
+         * will be called again when that happens.
+         */
+        fib_node_index_t *entries = NULL;
+        fib_protocol_t proto;
+
+        proto = fib_entry->fe_prefix.fp_proto;
+        vec_add1(entries, fib_entry_get_index(fib_entry));
+
+        if (fib_path_list_recursive_loop_detect(cover->fe_parent,
+                                                &entries))
+        {
+            src->fes_pl = fib_path_list_create_special(
+                              proto,
+                              FIB_PATH_LIST_FLAG_DROP,
+                              drop_dpo_get(fib_proto_to_dpo(proto)));
+        }
+        else
+        {
+            src->fes_pl = cover->fe_parent;
+        }
+        vec_free(entries);
+
+    }
+    fib_path_list_lock(src->fes_pl);
+
+    /*
+     * return go for install
+     */
+    return (!0);
+}
+
+/**
+ * Source Deactivate. 
+ * Called when the source is no longer best source on the entry
+ */
+static void
+fib_entry_src_rr_deactivate (fib_entry_src_t *src,
+			     const fib_entry_t *fib_entry)
+{
+    fib_entry_t *cover;
+
+    /*
+     * remove the depednecy on the covering entry
+     */
+    if (FIB_NODE_INDEX_INVALID != src->rr.fesr_cover)
+    {
+	cover = fib_entry_get(src->rr.fesr_cover);
+	fib_entry_cover_untrack(cover, src->rr.fesr_sibling);
+	src->rr.fesr_cover = FIB_NODE_INDEX_INVALID;
+    }
+
+    fib_path_list_unlock(src->fes_pl);
+    src->fes_pl = FIB_NODE_INDEX_INVALID;
+    src->fes_entry_flags = FIB_ENTRY_FLAG_NONE;
+}
+
+static fib_entry_src_cover_res_t
+fib_entry_src_rr_cover_change (fib_entry_src_t *src,
+			       const fib_entry_t *fib_entry)
+{
+    fib_entry_src_cover_res_t res = {
+	.install = !0,
+	.bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
+    };
+
+    if (FIB_NODE_INDEX_INVALID == src->rr.fesr_cover)
+    {
+	/*
+	 * the source may be added, but it is not active
+	 * if it is not tracking the cover.
+	 */
+	return (res);
+    }
+
+    /*
+     * this function is called when this entry's cover has a more specific
+     * entry inserted benaeth it. That does not necessarily mean that this
+     * entry is covered by the new prefix. check that
+     */
+    if (src->rr.fesr_cover != fib_table_get_less_specific(fib_entry->fe_fib_index,
+							  &fib_entry->fe_prefix))
+    {
+	fib_entry_src_rr_deactivate(src, fib_entry);
+	fib_entry_src_rr_activate(src, fib_entry);
+
+	/*
+	 * dependent children need to re-resolve to the new forwarding info
+	 */
+	res.bw_reason = FIB_NODE_BW_REASON_FLAG_EVALUATE;
+    }
+    return (res);
+}
+
+/*
+ * fib_entry_src_rr_cover_update
+ *
+ * This entry's cover has updated its forwarding info. This entry
+ * will need to re-inheret.
+ */
+static fib_entry_src_cover_res_t
+fib_entry_src_rr_cover_update (fib_entry_src_t *src,
+			       const fib_entry_t *fib_entry)
+{
+    fib_entry_src_cover_res_t res = {
+	.install = !0,
+	.bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
+    };
+    fib_node_index_t old_path_list;
+    fib_entry_t *cover;
+
+    if (FIB_NODE_INDEX_INVALID == src->rr.fesr_cover)
+    {
+	/*
+	 * the source may be added, but it is not active
+	 * if it is not tracking the cover.
+	 */
+	return (res);
+    }
+
+    cover = fib_entry_get(src->rr.fesr_cover);
+    old_path_list = src->fes_pl;
+
+    /*
+     * if the ocver is attached then install an attached-host path
+     * (like an adj-fib). Otherwise inherit the forwarding from the cover
+     */
+    if (FIB_ENTRY_FLAG_ATTACHED & fib_entry_get_flags_i(cover))
+    {
+	fib_entry_src_rr_resolve_via_connected(src, fib_entry, cover);
+    }
+    else
+    {
+	src->fes_pl = cover->fe_parent;
+    }
+    fib_path_list_lock(src->fes_pl);
+    fib_path_list_unlock(old_path_list);
+
+    /*
+     * dependent children need to re-resolve to the new forwarding info
+     */
+    res.bw_reason = FIB_NODE_BW_REASON_FLAG_EVALUATE;
+
+    return (res);
+}
+
+static u8*
+fib_entry_src_rr_format (fib_entry_src_t *src,
+			 u8* s)
+{
+    return (format(s, "cover:%d", src->rr.fesr_cover));
+}
+
+const static fib_entry_src_vft_t rr_src_vft = {
+    .fesv_init = fib_entry_src_rr_init,
+    .fesv_activate = fib_entry_src_rr_activate,
+    .fesv_deactivate = fib_entry_src_rr_deactivate,
+    .fesv_cover_change = fib_entry_src_rr_cover_change,
+    .fesv_cover_update = fib_entry_src_rr_cover_update,
+    .fesv_format = fib_entry_src_rr_format,
+};
+
+void
+fib_entry_src_rr_register (void)
+{
+    fib_entry_src_register(FIB_SOURCE_RR, &rr_src_vft);    
+    fib_entry_src_register(FIB_SOURCE_URPF_EXEMPT, &rr_src_vft);    
+}