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, 217 insertions, 0 deletions

diff --git a/src/vnet/bier/bier_imp_node.c b/src/vnet/bier/bier_imp_node.c
new file mode 100644
index 00000000000..e9aae93b460
--- /dev/null
+++ b/src/vnet/bier/bier_imp_node.c
@@ -0,0 +1,217 @@
+/*
+ * 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/bier/bier_imp.h>
+#include <vnet/bier/bier_hdr_inlines.h>
+#include <vnet/ip/ip.h>
+
+/**
+ * @brief A struct to hold tracing information for the BIER imposition
+ * node.
+ */
+typedef struct bier_imp_trace_t_
+{
+    /**
+     * BIER imposition object hit
+     */
+    index_t imp;
+
+    /**
+     * BIER hdr applied
+     */
+    bier_hdr_t hdr;
+} bier_imp_trace_t;
+
+always_inline uword
+bier_imp_dpo_inline (vlib_main_t * vm,
+                     vlib_node_runtime_t * node,
+                     vlib_frame_t * from_frame,
+                     fib_protocol_t fproto,
+                     bier_hdr_proto_id_t bproto)
+{
+    u32 n_left_from, next_index, * from, * to_next;
+
+    from = vlib_frame_vector_args (from_frame);
+    n_left_from = from_frame->n_vectors;
+
+    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)
+        {
+            vlib_buffer_t * b0;
+            bier_imp_t *bimp0;
+            bier_hdr_t *hdr0;
+            u32 bi0, bii0;
+            u32 next0;
+
+            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);
+
+            bii0 = vnet_buffer(b0)->ip.adj_index[VLIB_TX];
+            bimp0 = bier_imp_get(bii0);
+
+            if (FIB_PROTOCOL_IP4 == fproto)
+            {
+                /*
+                 * decrement the TTL on ingress to the BIER domain
+                 */
+                ip4_header_t * ip0 = vlib_buffer_get_current(b0);
+                u32 checksum0;
+
+                checksum0 = ip0->checksum + clib_host_to_net_u16 (0x0100);
+                checksum0 += checksum0 >= 0xffff;
+
+                ip0->checksum = checksum0;
+                ip0->ttl -= 1;
+
+                /*
+                 * calculate an entropy
+                 */
+                if (0 == vnet_buffer(b0)->ip.flow_hash)
+                {
+                    vnet_buffer(b0)->ip.flow_hash =
+                        ip4_compute_flow_hash (ip0, IP_FLOW_HASH_DEFAULT);
+                }
+            }
+            if (FIB_PROTOCOL_IP6 == fproto)
+            {
+                /*
+                 * decrement the TTL on ingress to the BIER domain
+                 */
+                ip6_header_t * ip0 = vlib_buffer_get_current(b0);
+
+                ip0->hop_limit -= 1;
+
+                /*
+                 * calculate an entropy
+                 */
+                if (0 == vnet_buffer(b0)->ip.flow_hash)
+                {
+                    vnet_buffer(b0)->ip.flow_hash =
+                        ip6_compute_flow_hash (ip0, IP_FLOW_HASH_DEFAULT);
+                }
+            }
+
+            /* Paint the BIER header */
+            vlib_buffer_advance(b0, -(sizeof(bier_hdr_t) +
+                                      bier_hdr_len_id_to_num_bytes(bimp0->bi_tbl.bti_hdr_len)));
+            hdr0 = vlib_buffer_get_current(b0);
+            clib_memcpy(hdr0, &bimp0->bi_hdr,
+                        (sizeof(bier_hdr_t) +
+                         bier_hdr_len_id_to_num_bytes(bimp0->bi_tbl.bti_hdr_len)));
+            /*
+             * Fixup the entropy and protocol, both of which have a
+             * zero value post the paint job
+             */
+            hdr0->bh_oam_dscp_proto |=
+                clib_host_to_net_u16(bproto << BIER_HDR_PROTO_FIELD_SHIFT);
+            hdr0->bh_first_word |=
+                clib_host_to_net_u32((vnet_buffer(b0)->ip.flow_hash &
+                                      BIER_HDR_ENTROPY_FIELD_MASK) <<
+                                     BIER_HDR_ENTROPY_FIELD_SHIFT);
+
+            /* next node */
+            next0 = bimp0->bi_dpo[fproto].dpoi_next_node;
+            vnet_buffer(b0)->ip.adj_index[VLIB_TX] =
+                bimp0->bi_dpo[fproto].dpoi_index;
+
+            if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED))
+            {
+                bier_imp_trace_t *tr =
+                    vlib_add_trace (vm, node, b0, sizeof (*tr));
+                tr->imp = bii0;
+                tr->hdr = *hdr0;
+            }
+
+            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);
+    }
+    return from_frame->n_vectors;
+}
+
+static u8 *
+format_bier_imp_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_imp_trace_t * t;
+    u32 indent;
+
+    t = va_arg (*args, bier_imp_trace_t *);
+    indent = format_get_indent (s);
+
+    s = format (s, "%U", format_bier_imp, t->imp, indent, BIER_SHOW_BRIEF);
+    return (s);
+}
+
+static uword
+bier_imp_ip4 (vlib_main_t * vm,
+              vlib_node_runtime_t * node,
+              vlib_frame_t * frame)
+{
+    return (bier_imp_dpo_inline(vm, node, frame,
+                                FIB_PROTOCOL_IP4,
+                                BIER_HDR_PROTO_IPV4));
+}
+
+VLIB_REGISTER_NODE (bier_imp_ip4_node) = {
+    .function = bier_imp_ip4,
+    .name = "bier-imp-ip4",
+    .vector_size = sizeof (u32),
+
+    .format_trace = format_bier_imp_trace,
+    .n_next_nodes = 1,
+    .next_nodes = {
+        [0] = "error-drop",
+    }
+};
+VLIB_NODE_FUNCTION_MULTIARCH (bier_imp_ip4_node, bier_imp_ip4)
+
+static uword
+bier_imp_ip6 (vlib_main_t * vm,
+              vlib_node_runtime_t * node,
+              vlib_frame_t * frame)
+{
+    return (bier_imp_dpo_inline(vm, node, frame,
+                                FIB_PROTOCOL_IP6,
+                                BIER_HDR_PROTO_IPV6));
+}
+
+VLIB_REGISTER_NODE (bier_imp_ip6_node) = {
+    .function = bier_imp_ip6,
+    .name = "bier-imp-ip6",
+    .vector_size = sizeof (u32),
+
+    .format_trace = format_bier_imp_trace,
+    .n_next_nodes = 1,
+    .next_nodes = {
+        [0] = "error-drop",
+    }
+};
+VLIB_NODE_FUNCTION_MULTIARCH (bier_imp_ip6_node, bier_imp_ip6)