Basic support for LISP-GPE encapsulated NSH packets

Change-Id: I97fedb0f70dd18ed9bbe985407cc5fe714e8a2e2
Signed-off-by: Florin Coras <fcoras@cisco.com>

1 files changed, 211 insertions, 0 deletions

diff --git a/src/vnet/adj/adj_nsh.c b/src/vnet/adj/adj_nsh.c
new file mode 100644
index 00000000000..9a0f9d8b9d6
--- /dev/null
+++ b/src/vnet/adj/adj_nsh.c
@@ -0,0 +1,211 @@
+/*
+ * Copyright (c) 2017 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/vnet.h>
+#include <vnet/adj/adj_nsh.h>
+#include <vnet/ip/ip.h>
+
+nsh_main_dummy_t nsh_main_dummy;
+
+/**
+ * @brief Trace data for a NSH Midchain
+ */
+typedef struct adj_nsh_trace_t_ {
+    /** Adjacency index taken. */
+    u32 adj_index;
+} adj_nsh_trace_t;
+
+static u8 *
+format_adj_nsh_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 *);
+    adj_nsh_trace_t * t = va_arg (*args, adj_nsh_trace_t *);
+
+    s = format (s, "adj-idx %d : %U",
+                t->adj_index,
+                format_ip_adjacency, t->adj_index, FORMAT_IP_ADJACENCY_NONE);
+    return s;
+}
+
+typedef enum adj_nsh_rewrite_next_t_
+{
+    ADJ_NSH_REWRITE_NEXT_DROP,
+} adj_gpe_rewrite_next_t;
+
+always_inline uword
+adj_nsh_rewrite_inline (vlib_main_t * vm,
+                       vlib_node_runtime_t * node,
+                       vlib_frame_t * frame,
+                       int is_midchain)
+{
+    u32 * from = vlib_frame_vector_args (frame);
+    u32 n_left_from, n_left_to_next, * to_next, next_index;
+    u32 cpu_index = os_get_cpu_number();
+
+    n_left_from = frame->n_vectors;
+    next_index = node->cached_next_index;
+
+    while (n_left_from > 0)
+    {
+        vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+        while (n_left_from > 0 && n_left_to_next > 0)
+        {
+            ip_adjacency_t * adj0;
+            vlib_buffer_t * p0;
+            char *h0;
+            u32 pi0, rw_len0, adj_index0, next0 = 0;
+            u32 tx_sw_if_index0;
+
+            pi0 = to_next[0] = from[0];
+            from += 1;
+            n_left_from -= 1;
+            to_next += 1;
+            n_left_to_next -= 1;
+
+            p0 = vlib_get_buffer (vm, pi0);
+            h0 = vlib_buffer_get_current (p0);
+
+            adj_index0 = vnet_buffer (p0)->ip.adj_index[VLIB_TX];
+
+            /* We should never rewrite a pkt using the MISS adjacency */
+            ASSERT(adj_index0);
+
+            adj0 = adj_get (adj_index0);
+
+            /* Guess we are only writing on simple IP4 header. */
+            vnet_rewrite_one_header(adj0[0], h0, sizeof(ip4_header_t));
+
+            /* Update packet buffer attributes/set output interface. */
+            rw_len0 = adj0[0].rewrite_header.data_bytes;
+            vnet_buffer(p0)->ip.save_rewrite_length = rw_len0;
+
+            vlib_increment_combined_counter(&adjacency_counters,
+                                            cpu_index,
+                                            adj_index0,
+                                            /* packet increment */ 0,
+                                            /* byte increment */ rw_len0);
+
+            /* Check MTU of outgoing interface. */
+            if (PREDICT_TRUE((vlib_buffer_length_in_chain (vm, p0)  <=
+                              adj0[0].rewrite_header.max_l3_packet_bytes)))
+            {
+                /* Don't adjust the buffer for ttl issue; icmp-error node wants
+                 * to see the IP headerr */
+                p0->current_data -= rw_len0;
+                p0->current_length += rw_len0;
+                tx_sw_if_index0 = adj0[0].rewrite_header.sw_if_index;
+
+                if (is_midchain)
+                {
+                    adj0->sub_type.midchain.fixup_func(vm, adj0, p0);
+                }
+
+                vnet_buffer (p0)->sw_if_index[VLIB_TX] = tx_sw_if_index0;
+
+                /*
+                 * Follow the feature ARC. this will result eventually in
+                 * the midchain-tx node
+                 */
+                vnet_feature_arc_start (nsh_main_dummy.output_feature_arc_index,
+                                        tx_sw_if_index0, &next0, p0);
+            }
+            else
+            {
+                /* can't fragment NSH */
+                next0 = ADJ_NSH_REWRITE_NEXT_DROP;
+            }
+
+            if (PREDICT_FALSE(p0->flags & VLIB_BUFFER_IS_TRACED))
+            {
+                adj_nsh_trace_t *tr = vlib_add_trace (vm, node,
+                                                     p0, sizeof (*tr));
+                tr->adj_index = vnet_buffer(p0)->ip.adj_index[VLIB_TX];
+            }
+
+            vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+                                             to_next, n_left_to_next,
+                                             pi0, next0);
+        }
+
+        vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+    return frame->n_vectors;
+}
+
+static uword
+adj_nsh_rewrite (vlib_main_t * vm,
+                vlib_node_runtime_t * node,
+                vlib_frame_t * frame)
+{
+    return adj_nsh_rewrite_inline (vm, node, frame, 0);
+}
+
+static uword
+adj_nsh_midchain (vlib_main_t * vm,
+                 vlib_node_runtime_t * node,
+                 vlib_frame_t * frame)
+{
+    return adj_nsh_rewrite_inline (vm, node, frame, 1);
+}
+
+VLIB_REGISTER_NODE (adj_nsh_rewrite_node) = {
+    .function = adj_nsh_rewrite,
+    .name = "adj-nsh-rewrite",
+    .vector_size = sizeof (u32),
+
+    .format_trace = format_adj_nsh_trace,
+
+    .n_next_nodes = 1,
+    .next_nodes = {
+        [ADJ_NSH_REWRITE_NEXT_DROP] = "error-drop",
+    },
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (adj_nsh_rewrite_node, adj_nsh_rewrite)
+
+VLIB_REGISTER_NODE (adj_nsh_midchain_node) = {
+    .function = adj_nsh_midchain,
+    .name = "adj-nsh-midchain",
+    .vector_size = sizeof (u32),
+
+    .format_trace = format_adj_nsh_trace,
+
+    .n_next_nodes = 1,
+    .next_nodes = {
+        [ADJ_NSH_REWRITE_NEXT_DROP] = "error-drop",
+    },
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (adj_nsh_midchain_node, adj_nsh_midchain)
+
+/* Built-in ip4 tx feature path definition */
+/* *INDENT-OFF* */
+VNET_FEATURE_ARC_INIT (nsh_output, static) =
+{
+  .arc_name  = "nsh-output",
+  .start_nodes = VNET_FEATURES ("adj-nsh-midchain"),
+  .arc_index_ptr = &nsh_main_dummy.output_feature_arc_index,
+};
+
+VNET_FEATURE_INIT (nsh_tx_drop, static) =
+{
+  .arc_name = "nsh-output",
+  .node_name = "error-drop",
+  .runs_before = 0,     /* not before any other features */
+};
+/* *INDENT-ON* */