MPLS Mcast

 1 - interface-DPO
        Used in the Data-plane to change a packet's input interface
 2 - MPLS multicast FIB entry
        Same as a unicast entry but it links to a replicate not a load-balance DPO
 3 - Multicast MPLS tunnel
        Update MPLS tunnels to use a FIB path-list to describe the endpoint[s]. Use the path-list to generate the forwarding chain (DPOs) to link to .
 4 - Resolve a path via a local label (of an mLDP LSP)
        For IP multicast entries to use an LSP in the replication list, we need to decribe the 'resolve-via-label' where the label is that of a multicast LSP.
 5 - MPLS disposition path sets RPF-ID
        For a interface-less LSP (i.e. mLDP not RSVP-TE) at the tail of the LSP we still need to perform an RPF check. An MPLS disposition DPO performs the MPLS pop validation checks and sets the RPF-ID in the packet.
 6 - RPF check with per-entry RPF-ID
       An RPF-ID is used instead of a real interface SW if index in the case the IP traffic arrives from an LSP that does not have an associated interface.

Change-Id: Ib92e177be919147bafeb599729abf3d1abc2f4b3
Signed-off-by: Neale Ranns <nranns@cisco.com>

1 files changed, 364 insertions, 0 deletions

diff --git a/src/vnet/dpo/mpls_disposition.c b/src/vnet/dpo/mpls_disposition.c
new file mode 100644
index 00000000000..5dc33fcfdbd
--- /dev/null
+++ b/src/vnet/dpo/mpls_disposition.c
@@ -0,0 +1,364 @@
+/*
+ * 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/ip/ip.h>
+#include <vnet/dpo/mpls_disposition.h>
+#include <vnet/mpls/mpls.h>
+
+/*
+ * pool of all MPLS Label DPOs
+ */
+mpls_disp_dpo_t *mpls_disp_dpo_pool;
+
+static mpls_disp_dpo_t *
+mpls_disp_dpo_alloc (void)
+{
+    mpls_disp_dpo_t *mdd;
+
+    pool_get_aligned(mpls_disp_dpo_pool, mdd, CLIB_CACHE_LINE_BYTES);
+    memset(mdd, 0, sizeof(*mdd));
+
+    dpo_reset(&mdd->mdd_dpo);
+
+    return (mdd);
+}
+
+static index_t
+mpls_disp_dpo_get_index (mpls_disp_dpo_t *mdd)
+{
+    return (mdd - mpls_disp_dpo_pool);
+}
+
+index_t
+mpls_disp_dpo_create (dpo_proto_t payload_proto,
+                      fib_rpf_id_t rpf_id,
+                      const dpo_id_t *dpo)
+{
+    mpls_disp_dpo_t *mdd;
+
+    mdd = mpls_disp_dpo_alloc();
+
+    mdd->mdd_payload_proto = payload_proto;
+    mdd->mdd_rpf_id = rpf_id;
+
+    dpo_stack(DPO_MPLS_DISPOSITION,
+              mdd->mdd_payload_proto,
+              &mdd->mdd_dpo,
+              dpo);
+
+    return (mpls_disp_dpo_get_index(mdd));
+}
+
+u8*
+format_mpls_disp_dpo (u8 *s, va_list *args)
+{
+    index_t index = va_arg (*args, index_t);
+    u32 indent = va_arg (*args, u32);
+    mpls_disp_dpo_t *mdd;
+
+    mdd = mpls_disp_dpo_get(index);
+
+    s = format(s, "mpls-disposition:[%d]:[%U]",
+               index,
+               format_dpo_proto, mdd->mdd_payload_proto);
+
+    s = format(s, "\n%U", format_white_space, indent);
+    s = format(s, "%U", format_dpo_id, &mdd->mdd_dpo, indent+2);
+
+    return (s);
+}
+
+static void
+mpls_disp_dpo_lock (dpo_id_t *dpo)
+{
+    mpls_disp_dpo_t *mdd;
+
+    mdd = mpls_disp_dpo_get(dpo->dpoi_index);
+
+    mdd->mdd_locks++;
+}
+
+static void
+mpls_disp_dpo_unlock (dpo_id_t *dpo)
+{
+    mpls_disp_dpo_t *mdd;
+
+    mdd = mpls_disp_dpo_get(dpo->dpoi_index);
+
+    mdd->mdd_locks--;
+
+    if (0 == mdd->mdd_locks)
+    {
+	dpo_reset(&mdd->mdd_dpo);
+	pool_put(mpls_disp_dpo_pool, mdd);
+    }
+}
+
+/**
+ * @brief A struct to hold tracing information for the MPLS label disposition
+ * node.
+ */
+typedef struct mpls_label_disposition_trace_t_
+{
+    index_t mdd;
+} mpls_label_disposition_trace_t;
+
+always_inline uword
+mpls_label_disposition_inline (vlib_main_t * vm,
+                              vlib_node_runtime_t * node,
+                              vlib_frame_t * from_frame,
+                              u8 payload_is_ip4,
+                              u8 payload_is_ip6)
+{
+    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 >= 4 && n_left_to_next >= 2)
+        {
+            mpls_disp_dpo_t *mdd0, *mdd1;
+            u32 bi0, mddi0, bi1, mddi1;
+            vlib_buffer_t * b0, *b1;
+            u32 next0, next1;
+
+            bi0 = to_next[0] = from[0];
+            bi1 = to_next[1] = from[1];
+
+            /* Prefetch next iteration. */
+            {
+                vlib_buffer_t * p2, * p3;
+
+                p2 = vlib_get_buffer (vm, from[2]);
+                p3 = vlib_get_buffer (vm, from[3]);
+
+                vlib_prefetch_buffer_header (p2, STORE);
+                vlib_prefetch_buffer_header (p3, STORE);
+
+                CLIB_PREFETCH (p2->data, sizeof (ip6_header_t), STORE);
+                CLIB_PREFETCH (p3->data, sizeof (ip6_header_t), STORE);
+            }
+
+            from += 2;
+            to_next += 2;
+            n_left_from -= 2;
+            n_left_to_next -= 2;
+
+            b0 = vlib_get_buffer (vm, bi0);
+            b1 = vlib_get_buffer (vm, bi1);
+
+            /* dst lookup was done by ip4 lookup */
+            mddi0 = vnet_buffer(b0)->ip.adj_index[VLIB_TX];
+            mddi1 = vnet_buffer(b1)->ip.adj_index[VLIB_TX];
+            mdd0 = mpls_disp_dpo_get(mddi0);
+            mdd1 = mpls_disp_dpo_get(mddi1);
+
+            if (payload_is_ip4)
+            {
+                /*
+                 * decrement the TTL on ingress to the LSP
+                 */
+            }
+            else if (payload_is_ip6)
+            {
+                /*
+                 * decrement the TTL on ingress to the LSP
+                 */
+            }
+ 
+            next0 = mdd0->mdd_dpo.dpoi_next_node;
+            next1 = mdd1->mdd_dpo.dpoi_next_node;
+            vnet_buffer(b0)->ip.adj_index[VLIB_TX] = mdd0->mdd_dpo.dpoi_index;
+            vnet_buffer(b1)->ip.adj_index[VLIB_TX] = mdd1->mdd_dpo.dpoi_index;
+            vnet_buffer(b0)->ip.rpf_id = mdd0->mdd_rpf_id;
+            vnet_buffer(b1)->ip.rpf_id = mdd1->mdd_rpf_id;
+
+            if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED))
+            {
+                mpls_label_disposition_trace_t *tr =
+                    vlib_add_trace (vm, node, b0, sizeof (*tr));
+
+                tr->mdd = mddi0;
+            }
+            if (PREDICT_FALSE(b1->flags & VLIB_BUFFER_IS_TRACED))
+            {
+                mpls_label_disposition_trace_t *tr =
+                    vlib_add_trace (vm, node, b1, sizeof (*tr));
+                tr->mdd = mddi1;
+            }
+
+            vlib_validate_buffer_enqueue_x2(vm, node, next_index, to_next,
+                                            n_left_to_next,
+                                            bi0, bi1, next0, next1);
+        }
+
+        while (n_left_from > 0 && n_left_to_next > 0)
+        {
+            mpls_disp_dpo_t *mdd0;
+            vlib_buffer_t * b0;
+            u32 bi0, mddi0;
+            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);
+
+            /* dst lookup was done by ip4 lookup */
+            mddi0 = vnet_buffer(b0)->ip.adj_index[VLIB_TX];
+            mdd0 = mpls_disp_dpo_get(mddi0);
+
+            if (payload_is_ip4)
+            {
+                /*
+                 * decrement the TTL on ingress to the LSP
+                 */
+            }
+            else if (payload_is_ip6)
+            {
+                /*
+                 * decrement the TTL on ingress to the LSP
+                 */
+            }
+            else
+            {
+            }
+
+            next0 = mdd0->mdd_dpo.dpoi_next_node;
+            vnet_buffer(b0)->ip.adj_index[VLIB_TX] = mdd0->mdd_dpo.dpoi_index;
+            vnet_buffer(b0)->ip.rpf_id = mdd0->mdd_rpf_id;
+
+            if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED))
+            {
+                mpls_label_disposition_trace_t *tr =
+                    vlib_add_trace (vm, node, b0, sizeof (*tr));
+                tr->mdd = mddi0;
+            }
+
+            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_mpls_label_disposition_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 *);
+    CLIB_UNUSED (mpls_label_disposition_trace_t * t);
+
+    t = va_arg (*args, mpls_label_disposition_trace_t *);
+
+    s = format(s, "disp:%d", t->mdd);
+    return (s);
+}
+
+static uword
+ip4_mpls_label_disposition (vlib_main_t * vm,
+                           vlib_node_runtime_t * node,
+                           vlib_frame_t * frame)
+{
+    return (mpls_label_disposition_inline(vm, node, frame, 1, 0));
+}
+
+VLIB_REGISTER_NODE (ip4_mpls_label_disposition_node) = {
+    .function = ip4_mpls_label_disposition,
+    .name = "ip4-mpls-label-disposition",
+    .vector_size = sizeof (u32),
+
+    .format_trace = format_mpls_label_disposition_trace,
+    .n_next_nodes = 1,
+    .next_nodes = {
+        [0] = "ip4-drop",
+    }
+};
+VLIB_NODE_FUNCTION_MULTIARCH (ip4_mpls_label_disposition_node,
+                              ip4_mpls_label_disposition)
+
+static uword
+ip6_mpls_label_disposition (vlib_main_t * vm,
+                           vlib_node_runtime_t * node,
+                           vlib_frame_t * frame)
+{
+    return (mpls_label_disposition_inline(vm, node, frame, 0, 1));
+}
+
+VLIB_REGISTER_NODE (ip6_mpls_label_disposition_node) = {
+    .function = ip6_mpls_label_disposition,
+    .name = "ip6-mpls-label-disposition",
+    .vector_size = sizeof (u32),
+
+    .format_trace = format_mpls_label_disposition_trace,
+    .n_next_nodes = 1,
+    .next_nodes = {
+        [0] = "ip6-drop",
+    }
+};
+VLIB_NODE_FUNCTION_MULTIARCH (ip6_mpls_label_disposition_node,
+                              ip6_mpls_label_disposition)
+
+static void
+mpls_disp_dpo_mem_show (void)
+{
+    fib_show_memory_usage("MPLS label",
+			  pool_elts(mpls_disp_dpo_pool),
+			  pool_len(mpls_disp_dpo_pool),
+			  sizeof(mpls_disp_dpo_t));
+}
+
+const static dpo_vft_t mdd_vft = {
+    .dv_lock = mpls_disp_dpo_lock,
+    .dv_unlock = mpls_disp_dpo_unlock,
+    .dv_format = format_mpls_disp_dpo,
+    .dv_mem_show = mpls_disp_dpo_mem_show,
+};
+
+const static char* const mpls_label_disp_ip4_nodes[] =
+{
+    "ip4-mpls-label-disposition",
+    NULL,
+};
+const static char* const mpls_label_disp_ip6_nodes[] =
+{
+    "ip6-mpls-label-disposition",
+    NULL,
+};
+const static char* const * const mpls_label_disp_nodes[DPO_PROTO_NUM] =
+{
+    [DPO_PROTO_IP4]  = mpls_label_disp_ip4_nodes,
+    [DPO_PROTO_IP6]  = mpls_label_disp_ip6_nodes,
+};
+
+
+void
+mpls_disp_dpo_module_init (void)
+{
+    dpo_register(DPO_MPLS_DISPOSITION, &mdd_vft, mpls_label_disp_nodes);
+}