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, 175 insertions, 0 deletions

diff --git a/src/vnet/bier/bier_input.c b/src/vnet/bier/bier_input.c
new file mode 100644
index 00000000000..88b37fc80c0
--- /dev/null
+++ b/src/vnet/bier/bier_input.c
@@ -0,0 +1,175 @@
+/*
+ * 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/buffer.h>
+
+#include <vnet/bier/bier_table.h>
+#include <vnet/bier/bier_hdr_inlines.h>
+
+typedef enum {
+#define bier_error(n,s) BIER_INPUT_ERROR_##n,
+#include <vnet/bier/bier_input_error.def>
+#undef bier_error
+    BIER_INPUT_N_ERROR,
+} bier_input_error_t;
+
+static char * bier_error_strings[] = {
+#define bier_error(n,s) s,
+#include <vnet/bier/bier_input_error.def>
+#undef bier_error
+};
+
+typedef enum bier_input_next_t_ {
+    BIER_INPUT_NEXT_BIER_LOOKUP,
+    BIER_INPUT_NEXT_DROP,
+    BIER_INPUT_N_NEXT,
+} bier_input_next_t;
+
+vlib_node_registration_t bier_input_node;
+
+/**
+ * @brief Packet trace recoed for a BIER output
+ */
+typedef struct bier_input_trace_t_
+{
+    u32 next_index;
+    u32 bt_index;
+} bier_input_trace_t;
+
+static int
+bier_hdr_validate (bier_hdr_t *bier_hdr,
+                   bier_hdr_len_id_t expected_length)
+{
+    /*
+     * checks:
+     *  - the version field must be 1
+     *  - the header length matches the length expected
+     */
+    if (PREDICT_FALSE((BIER_HDR_VERSION_1 != bier_hdr_get_version(bier_hdr)) ||
+                      (expected_length != bier_hdr_get_len_id(bier_hdr)))) {
+        return (0);
+    }
+
+    return (1);
+}
+
+static uword
+bier_input (vlib_main_t * vm,
+            vlib_node_runtime_t * node,
+            vlib_frame_t * from_frame)
+{
+    u32 n_left_from, next_index, * from, * to_next;
+
+    from = vlib_frame_vector_args (from_frame);
+    n_left_from = from_frame->n_vectors;
+
+    /*
+     * objection your honour! speculation!
+     */
+    next_index = node->cached_next_index;
+
+    while (n_left_from > 0)
+    {
+        u32 n_left_to_next;
+
+        vlib_get_next_frame (vm, node, next_index,
+                             to_next, n_left_to_next);
+
+        while (n_left_from > 0 && n_left_to_next > 0)
+        {
+            const bier_table_t *bt0;
+            vlib_buffer_t * b0;
+            bier_hdr_t * bh0;
+            u32 bi0, next0;
+            u32 bt_index0;
+
+            bi0 = from[0];
+            to_next[0] = bi0;
+            from += 1;
+            to_next += 1;
+            n_left_from -= 1;
+            n_left_to_next -= 1;
+
+            b0 = vlib_get_buffer (vm, bi0);
+            bh0 = vlib_buffer_get_current (b0);
+            bier_hdr_ntoh(bh0);
+
+            /*
+             * In the MPLS decap node we squirelled away the
+             * index for the BIER table as the tx adjacency
+             */
+            bt_index0 = vnet_buffer(b0)->ip.adj_index[VLIB_TX];
+            bt0 = bier_table_get(bt_index0);
+
+            if (PREDICT_TRUE(bier_hdr_validate(bh0, bt0->bt_id.bti_hdr_len)))
+            {
+                next0 = BIER_INPUT_NEXT_BIER_LOOKUP;
+            } else {
+                next0 = BIER_INPUT_NEXT_DROP;
+                b0->error = node->errors[BIER_INPUT_ERROR_INVALID_HEADER];
+            }
+
+            if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED))
+            {
+                bier_input_trace_t *tr;
+
+                tr = vlib_add_trace (vm, node, b0, sizeof (*tr));
+                tr->next_index = next0;
+                tr->bt_index = bt_index0;
+            }
+
+            vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+                                             to_next, n_left_to_next,
+                                             bi0, next0);
+        }
+
+        vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+    vlib_node_increment_counter (vm, bier_input_node.index,
+                                 BIER_INPUT_ERROR_PKTS_VALID,
+                                 from_frame->n_vectors);
+    return (from_frame->n_vectors);
+}
+
+static u8 *
+format_bier_input_trace (u8 * s, va_list * args)
+{
+    CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+    CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+    bier_input_trace_t * t = va_arg (*args, bier_input_trace_t *);
+
+    s = format (s, " next [%d], BIER Table index %d",
+                t->next_index, t->bt_index);
+    return s;
+}
+
+VLIB_REGISTER_NODE (bier_input_node) = {
+    .function = bier_input,
+    .name = "bier-input",
+    /* Takes a vector of packets. */
+    .vector_size = sizeof (u32),
+
+    .n_errors = BIER_INPUT_N_ERROR,
+    .error_strings = bier_error_strings,
+
+    .n_next_nodes = BIER_INPUT_N_NEXT,
+    .next_nodes = {
+        [BIER_INPUT_NEXT_BIER_LOOKUP] = "bier-lookup",
+        [BIER_INPUT_NEXT_DROP] = "bier-drop",
+    },
+
+    .format_trace = format_bier_input_trace,
+};