BIER

- see draft-ietf-bier-mpls-encapsulation-10
- midpoint, head and tail functions
- supported payload protocols; IPv4 and IPv6 only.

Change-Id: I59d7363bb6fdfdce8e4016a68a9c8f5a5e5791cb
Signed-off-by: Neale Ranns <nranns@cisco.com>

1 files changed, 198 insertions, 0 deletions

diff --git a/src/vnet/bier/bier_fmask.h b/src/vnet/bier/bier_fmask.h
new file mode 100644
index 00000000000..d5ff4590ffe
--- /dev/null
+++ b/src/vnet/bier/bier_fmask.h
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+/*
+ * 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.
+ */
+/**
+ * @brief bier_fmask : The BIER fmask
+ *
+ * The BIER fmask contains the bitString that is applied to packets that
+ * egress towards the next-hop. As such the fmask is part of the rewrite
+ * (adj) for that next-hop. It it thus an extension of the next-hop and in
+ * no way associated with the bit-position(s) that are reachable through it.
+ * Fmasks are thus shared by bit-positions that egress throught the same
+ * nh (BFR-NBR).
+ * Deag fmasks are also shread in the event that a router has local
+ * bit-positions. This is necessary to prevent the router recieving two copies
+ * of each packet. Consequently it also means that they share the same
+ * disposition data for the global data.
+ */
+
+#ifndef __BIER_FMASK_H__
+#define __BIER_FMASK_H__
+
+#include <vlib/vlib.h>
+
+#include <vnet/fib/fib_node.h>
+#include <vnet/mpls/packet.h>
+#include <vnet/dpo/dpo.h>
+
+#include <vnet/bier/bier_types.h>
+#include <vnet/bier/bier_fmask_db.h>
+
+/**
+ * A struct that represents the reference counting of the bits
+ */
+typedef struct bier_fmask_bits_t_ {
+    /**
+     * each bit in the mask needs to be reference counted
+     * and set/cleared on the 0->1 and 1->0 transitions.
+     */
+    bier_bit_string_t bfmb_input_reset_string;
+    u32 *bfmb_refs;
+
+    /**
+     * The total number of references to bits set on this mask
+     * in effect a count of the number of children.
+     */
+    uint32_t bfmb_count;
+} bier_fmask_bits_t;
+
+/**
+ * Flags on fmask
+ */
+typedef enum bier_fmask_attributes_t_
+{
+    BIER_FMASK_ATTR_FIRST,
+    BIER_FMASK_ATTR_FORWARDING = BIER_FMASK_ATTR_FIRST,
+    BIER_FMASK_ATTR_DISP,
+    BIER_FMASK_ATTR_LAST = BIER_FMASK_ATTR_DISP,
+} bier_fmask_attributes_t;
+
+#define BIER_FMASK_ATTR_NAMES {                         \
+     [BIER_FMASK_ATTR_FORWARDING] = "forwarding",       \
+     [BIER_FMASK_ATTR_DISP] = "disposition",            \
+}
+
+#define FOR_EACH_BIER_FMASK_ATTR(_item)          \
+    for (_item =  BIER_FMASK_ATTR_FIRST;         \
+         _item <= BIER_FMASK_ATTR_LAST;          \
+         _item++)
+
+typedef enum bier_fmask_flags_t_
+{
+    BIER_FMASK_FLAG_FORWARDING = (1 << BIER_FMASK_ATTR_FORWARDING),
+    BIER_FMASK_FLAG_DISP = (1 << BIER_FMASK_ATTR_DISP),
+} bier_fmask_flags_t;
+
+/**
+ * An outgoing BIER mask. aka forwarding bit mask (in the RFCs)
+ *
+ * This mask's function is two-fold
+ *  1 - it is logical-AND with the input packet header to produce the
+ *      output packet header
+ *  2 - it is logical NAND with the input packet header to modify the bit-mask
+ *      for the next lookup
+ */
+typedef struct bier_fmask_t_ {
+    /**
+     * The BIER fmask is a child of a FIB entry in the FIB graph.
+     */
+    fib_node_t bfm_node;
+
+    /**
+     * operational/state flags on the fmask
+     */
+    bier_fmask_flags_t bfm_flags;
+
+    /**
+     * The bits, and their ref counts, that are set on this mask
+     * This mask changes as BIER entries link to and from this fmask
+     */
+    bier_fmask_bits_t bfm_bits;
+
+    struct
+    {
+        /**
+         * The key to this fmask - used for store/lookup in the DB
+         */
+        bier_fmask_id_t bfm_id;
+
+        /**
+         * The BIER Table this Fmask is used in
+         */
+        index_t bfm_fib_index;
+    };
+
+    union
+    {
+        /**
+         * For forwarding via a next-hop
+         */
+        struct
+        {
+            /**
+             * The parent fib entry
+             */
+            fib_node_index_t bfm_fei;
+            /**
+             * The MPLS label to paint on the header during forwarding
+             */
+            mpls_label_t bfm_label;
+        };
+
+        /**
+         * For disposition
+         */
+        struct
+        {
+            /**
+             * The parent disposition table object
+             */
+            index_t bfm_disp;
+        };
+    };
+
+    /**
+     * the index of this fmask in the parent's child list.
+     */
+    u32 bfm_sibling;
+
+    /**
+     * The index into the adj table for the adj that
+     * this fmask resolves via
+     */
+    dpo_id_t bfm_dpo;
+} bier_fmask_t;
+
+extern void bier_fmask_link(index_t bfmi, bier_bp_t bp);
+extern void bier_fmask_unlink(index_t bfmi, bier_bp_t bp);
+extern void bier_fmask_unlock(index_t bfmi);
+extern void bier_fmask_lock(index_t bfmi);
+
+extern index_t bier_fmask_create_and_lock(const bier_fmask_id_t *fmid,
+                                          index_t bti,
+                                          const fib_route_path_t *rpath);
+
+extern u8* format_bier_fmask(u8 *s, va_list *ap);
+
+extern void bier_fmask_contribute_forwarding(index_t bfmi,
+                                             dpo_id_t *dpo);
+
+extern u32 bier_fmask_child_add (fib_node_index_t fib_entry_index,
+                                 fib_node_type_t child_type,
+                                 fib_node_index_t child_index);
+extern void bier_fmask_child_remove (fib_node_index_t fib_entry_index,
+                                     u32 sibling_index);
+
+/*
+ * provided for fast data-path access
+ */
+bier_fmask_t *bier_fmask_pool;
+
+static inline bier_fmask_t *
+bier_fmask_get (u32 index)
+{
+    return (pool_elt_at_index(bier_fmask_pool, index));
+}
+
+#endif