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, 195 insertions, 0 deletions

diff --git a/src/vnet/bier/bier_output.c b/src/vnet/bier/bier_output.c
new file mode 100644
index 00000000000..fce6c50b309
--- /dev/null
+++ b/src/vnet/bier/bier_output.c
@@ -0,0 +1,195 @@
+/*
+ * 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_fmask.h>
+#include <vnet/bier/bier_hdr_inlines.h>
+#include <vlib/vlib.h>
+
+static char * bier_output_error_strings[] = {
+#define bier_error(n,s) s,
+#include <vnet/bier/bier_output_error.def>
+#undef bier_error
+};
+
+/*
+ * Keep these values sematically the same as BIER output
+ */
+#define foreach_bier_output_next                \
+    _(DROP, "bier-drop")
+
+typedef enum {
+#define _(s,n) BIER_OUTPUT_NEXT_##s,
+    foreach_bier_output_next
+#undef _
+    BIER_OUTPUT_N_NEXT,
+} bier_output_next_t;
+
+typedef enum {
+#define bier_error(n,s) BIER_OUTPUT_ERROR_##n,
+#include <vnet/bier/bier_output_error.def>
+#undef bier_error
+    BIER_OUTPUT_N_ERROR,
+} bier_output_error_t;
+
+/**
+ * Forward declaration
+ */
+vlib_node_registration_t bier_output_node;
+
+/**
+ * @brief Packet trace recoed for a BIER output
+ */
+typedef struct bier_output_trace_t_
+{
+    u32 next_index;
+    index_t bfm_index;
+} bier_output_trace_t;
+
+static uword
+bier_output (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;
+
+    // vnet_buffer(b0)->sw_if_index[VLIB_TX] = d0->tx_fib_index;
+
+    /*
+     * 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)
+        {
+            bier_output_next_t next0;
+            bier_bit_string_t bbs;
+            vlib_buffer_t * b0;
+            bier_fmask_t *bfm0;
+            bier_hdr_t *bh0;
+            u32 bi0, *h0;
+            u32 bfmi0;
+
+            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_bit_string_init_from_hdr(bh0, &bbs);
+
+            /*
+             * In the BIER Lookup node we squirelled away the
+             * BIER fmask index as the adj index
+             */
+            bfmi0 = vnet_buffer (b0)->ip.adj_index[VLIB_TX];
+            bfm0 = bier_fmask_get(bfmi0);
+
+            /*
+             * perform the logical AND of the packet's mask with
+             * that of the fmask objects, to reset the bits that
+             * are only on the shortest path the the fmask NH.
+             */
+            bier_bit_string_logical_and_string(
+                &bfm0->bfm_bits.bfmb_input_reset_string,
+                &bbs);
+
+            /*
+             * this is the last time we touch the BIER header
+             * so flip to network order
+             */
+            bier_hdr_hton(bh0);
+
+            /*
+             * paint the BIER peer's label
+             */
+            if (!(bfm0->bfm_flags & BIER_FMASK_FLAG_DISP))
+            {
+                vlib_buffer_advance(b0, -(word)sizeof(mpls_label_t));
+                h0 = vlib_buffer_get_current(b0);
+                h0[0] = bfm0->bfm_label;
+            }
+
+            /*
+             * setup next graph node
+             */
+            next0 = bfm0->bfm_dpo.dpoi_next_node;
+            vnet_buffer(b0)->ip.adj_index[VLIB_TX] = bfm0->bfm_dpo.dpoi_index;
+
+            if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED))
+            {
+                bier_output_trace_t *tr;
+
+                tr = vlib_add_trace (vm, node, b0, sizeof (*tr));
+                tr->next_index = next0;
+                tr->bfm_index = bfmi0;
+            }
+
+            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_output_node.index,
+                                 BIER_OUTPUT_ERROR_NONE,
+                                 from_frame->n_vectors);
+    return (from_frame->n_vectors);
+}
+
+static u8 *
+format_bier_output_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_output_trace_t * t = va_arg (*args, bier_output_trace_t *);
+
+    s = format (s, " next [%d], BFM index %d",
+                t->next_index, t->bfm_index);
+    return s;
+}
+
+VLIB_REGISTER_NODE (bier_output_node) = {
+    .function = bier_output,
+    .name = "bier-output",
+    /* Takes a vector of packets. */
+    .vector_size = sizeof (u32),
+
+    .n_errors = BIER_OUTPUT_N_ERROR,
+    .error_strings = bier_output_error_strings,
+
+    .n_next_nodes = BIER_OUTPUT_N_NEXT,
+    .next_nodes = {
+        [BIER_OUTPUT_NEXT_DROP] = "bier-drop",
+    },
+
+    .format_trace = format_bier_output_trace,
+};