MFIB: recurse resolution through an MFIB entry

Change-Id: I8dc261e40b8398c5c8ab6bb69ecebbd0176055d9
Signed-off-by: Neale Ranns <nranns@cisco.com>

1 files changed, 180 insertions, 0 deletions

diff --git a/src/vnet/mfib/mfib_entry_cover.c b/src/vnet/mfib/mfib_entry_cover.c
new file mode 100644
index 00000000000..6caeb1b6928
--- /dev/null
+++ b/src/vnet/mfib/mfib_entry_cover.c
@@ -0,0 +1,180 @@
+/*
+ * 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/mfib/mfib_entry_cover.h>
+#include <vnet/mfib/mfib_entry_src.h>
+#include <vnet/fib/fib_node_list.h>
+
+u32
+mfib_entry_cover_track (mfib_entry_t* cover,
+		       fib_node_index_t covered)
+{
+    mfib_entry_delegate_t *mfed;
+
+    MFIB_ENTRY_DBG(cover, "cover-track %d", covered);
+
+    ASSERT(mfib_entry_get_index(cover) != covered);
+
+    mfed = mfib_entry_delegate_get(cover, MFIB_ENTRY_DELEGATE_COVERED);
+
+    if (NULL == mfed)
+    {
+        mfed = mfib_entry_delegate_find_or_add(cover, MFIB_ENTRY_DELEGATE_COVERED);
+        mfed->mfd_list = fib_node_list_create();
+    }
+
+    return (fib_node_list_push_front(mfed->mfd_list,
+                                     0, FIB_NODE_TYPE_MFIB_ENTRY,
+                                     covered));
+}
+
+void
+mfib_entry_cover_untrack (mfib_entry_t* cover,
+			 u32 tracked_index)
+{
+    mfib_entry_delegate_t *mfed;
+
+    MFIB_ENTRY_DBG(cover, "cover-untrack @ %d", tracked_index);
+
+    mfed = mfib_entry_delegate_get(cover, MFIB_ENTRY_DELEGATE_COVERED);
+
+    if (NULL == mfed)
+        return;
+
+    fib_node_list_remove(mfed->mfd_list, tracked_index);
+
+    if (0 == fib_node_list_get_size(mfed->mfd_list))
+    {
+        fib_node_list_destroy(&mfed->mfd_list);
+        mfib_entry_delegate_remove(cover, MFIB_ENTRY_DELEGATE_COVERED);        
+    }
+}
+
+/**
+ * Internal struct to hold user supplied paraneters for the cover walk
+ */
+typedef struct mfib_enty_cover_walk_ctx_t_ {
+    mfib_entry_t *cover;
+    mfib_entry_covered_walk_t walk;
+    void *ctx;
+} mfib_enty_cover_walk_ctx_t;
+
+static int
+mfib_entry_cover_walk_node_ptr (fib_node_ptr_t *depend,
+                                void *args)
+{
+    mfib_enty_cover_walk_ctx_t *ctx = args;
+
+    ctx->walk(ctx->cover, depend->fnp_index, ctx->ctx);
+
+    /* continue */
+    return (1);
+}
+
+void
+mfib_entry_cover_walk (mfib_entry_t *cover,
+		      mfib_entry_covered_walk_t walk,
+		      void *args)
+{
+    mfib_entry_delegate_t *mfed;
+
+    mfed = mfib_entry_delegate_get(cover, MFIB_ENTRY_DELEGATE_COVERED);
+
+    if (NULL == mfed)
+        return;
+
+    mfib_enty_cover_walk_ctx_t ctx = {
+        .cover = cover,
+        .walk = walk,
+        .ctx = args,
+    };
+
+    fib_node_list_walk(mfed->mfd_list,
+                       mfib_entry_cover_walk_node_ptr,
+                       &ctx);
+}
+
+static int
+mfib_entry_cover_change_one (mfib_entry_t *cover,
+			    fib_node_index_t covered,
+			    void *args)
+{
+    fib_node_index_t new_cover;
+
+    /*
+     * The 3 entries involved here are:
+     *   cover - the least specific. It will cover both the others
+     *  new_cover - the enty just inserted below the cover
+     *  covered - the entry that was tracking the cover.
+     *
+     * The checks below are to determine if new_cover is a cover for covered.
+     */
+    new_cover = pointer_to_uword(args);
+
+    if (FIB_NODE_INDEX_INVALID == new_cover)
+    {
+	/*
+	 * nothing has been inserted, which implies the cover was removed.
+	 * 'cover' is thus the new cover.
+	 */
+	mfib_entry_cover_changed(covered);
+    }
+    else if (new_cover != covered)
+    {
+	const mfib_prefix_t *pfx_covered, *pfx_new_cover;
+
+	pfx_covered = mfib_entry_get_prefix(covered);
+	pfx_new_cover = mfib_entry_get_prefix(new_cover);
+
+	if (mfib_prefix_is_cover(pfx_new_cover, pfx_covered))
+	{
+	    mfib_entry_cover_changed(covered);
+	}
+    }
+    /* continue */
+    return (1);
+}
+
+void
+mfib_entry_cover_change_notify (fib_node_index_t cover_index,
+                                fib_node_index_t covered)
+{
+    mfib_entry_t *cover;
+
+    cover = mfib_entry_get(cover_index);
+
+    mfib_entry_cover_walk(cover, 
+                          mfib_entry_cover_change_one,
+                          uword_to_pointer(covered, void*));
+}
+
+static int
+mfib_entry_cover_update_one (mfib_entry_t *cover,
+			    fib_node_index_t covered,
+			    void *args)
+{
+    mfib_entry_cover_updated(covered);
+
+    /* continue */
+    return (1);
+}
+
+void
+mfib_entry_cover_update_notify (mfib_entry_t *mfib_entry)
+{
+    mfib_entry_cover_walk(mfib_entry, 
+			 mfib_entry_cover_update_one,
+			 NULL);
+}