MPLS lookup DPO does not pop the label (nor does it handle replicate)

Change-Id: I7de6b96631d1645d0eadd38525860d84d78e316d
Signed-off-by: Neale Ranns <nranns@cisco.com>

5 files changed, 84 insertions, 19 deletions

diff --git a/src/vnet/dpo/lookup_dpo.c b/src/vnet/dpo/lookup_dpo.c
index 96fedd27ce9..a96e9dbb42a 100644
--- a/src/vnet/dpo/lookup_dpo.c
+++ b/src/vnet/dpo/lookup_dpo.c
@@ -15,8 +15,8 @@
 
 #include <vnet/ip/ip.h>
 #include <vnet/dpo/lookup_dpo.h>
-#include <vnet/dpo/load_balance.h>
-#include <vnet/mpls/mpls.h>
+#include <vnet/dpo/load_balance_map.h>
+#include <vnet/mpls/mpls_lookup.h>
 #include <vnet/fib/fib_table.h>
 #include <vnet/fib/ip4_fib.h>
 #include <vnet/fib/ip6_fib.h>
@@ -961,7 +961,7 @@ lookup_dpo_mpls_inline (vlib_main_t * vm,
 
         while (n_left_from > 0 && n_left_to_next > 0)
         {
-            u32 bi0, lkdi0, lbi0, fib_index0,  next0;
+            u32 bi0, lkdi0, lbi0, fib_index0, next0, hash0;
             const mpls_unicast_header_t * hdr0;
             const load_balance_t *lb0;
             const lookup_dpo_t * lkd0;
@@ -1000,15 +1000,32 @@ lookup_dpo_mpls_inline (vlib_main_t * vm,
             /* do lookup */
             lbi0 = mpls_fib_table_forwarding_lookup (fib_index0, hdr0);
             lb0  = load_balance_get(lbi0);
-            dpo0 = load_balance_get_bucket_i(lb0, 0);
 
+            if (PREDICT_FALSE(lb0->lb_n_buckets > 1))
+            {
+                hash0 = vnet_buffer (b0)->ip.flow_hash =
+                mpls_compute_flow_hash(hdr0, lb0->lb_hash_config);
+                dpo0 = load_balance_get_bucket_i
+                (lb0,
+                 (hash0 & (lb0->lb_n_buckets_minus_1)));
+            }
+            else
+            {
+                dpo0 = load_balance_get_bucket_i (lb0, 0);
+            }
             next0 = dpo0->dpoi_next_node;
-            vnet_buffer(b0)->ip.adj_index[VLIB_TX] = dpo0->dpoi_index;
+
+            vnet_buffer (b0)->ip.adj_index[VLIB_TX] = dpo0->dpoi_index;
 
             vlib_increment_combined_counter
                 (cm, cpu_index, lbi0, 1,
                  vlib_buffer_length_in_chain (vm, b0));
 
+            vnet_buffer (b0)->mpls.ttl = ((char*)hdr0)[3];
+            vnet_buffer (b0)->mpls.exp = (((char*)hdr0)[2] & 0xe) >> 1;
+            vnet_buffer (b0)->mpls.first = 1;
+            vlib_buffer_advance(b0, sizeof(*hdr0));
+
 	    if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED)) 
             {
                 lookup_trace_t *tr = vlib_add_trace (vm, node, 
diff --git a/src/vnet/ip/ip4_forward.c b/src/vnet/ip/ip4_forward.c
index 7352c2e718d..845e2f195b9 100644
--- a/src/vnet/ip/ip4_forward.c
+++ b/src/vnet/ip/ip4_forward.c
@@ -2461,7 +2461,6 @@ ip4_rewrite_inline (vlib_main_t * vm,
 		}
 
 	      /* Verify checksum. */
-	      ASSERT (ip0->checksum == ip4_header_checksum (ip0));
 	      ASSERT (ip1->checksum == ip4_header_checksum (ip1));
 	    }
 	  else
diff --git a/src/vnet/mpls/mpls_lookup.c b/src/vnet/mpls/mpls_lookup.c
index 4424f62cff5..5dd6980c727 100644
--- a/src/vnet/mpls/mpls_lookup.c
+++ b/src/vnet/mpls/mpls_lookup.c
@@ -17,12 +17,20 @@
 
 #include <vlib/vlib.h>
 #include <vnet/pg/pg.h>
-#include <vnet/mpls/mpls.h>
+#include <vnet/mpls/mpls_lookup.h>
 #include <vnet/fib/mpls_fib.h>
 #include <vnet/dpo/load_balance.h>
 
+
+/**
+ * Static MPLS VLIB forwarding node
+ */
 vlib_node_registration_t mpls_lookup_node;
 
+/**
+ * The arc/edge from the MPLS lookup node to the MPLS replicate node
+ */
+
 typedef struct {
   u32 next_index;
   u32 lb_index;
@@ -47,18 +55,6 @@ format_mpls_lookup_trace (u8 * s, va_list * args)
   return s;
 }
 
-/*
- * Compute flow hash. 
- * We'll use it to select which adjacency to use for this flow.  And other things.
- */
-always_inline u32
-mpls_compute_flow_hash (const mpls_unicast_header_t * hdr,
-                        flow_hash_config_t flow_hash_config)
-{
-    // FIXME
-    return (vnet_mpls_uc_get_label(hdr->label_exp_s_ttl));
-}
-
 static inline uword
 mpls_lookup (vlib_main_t * vm,
              vlib_node_runtime_t * node,
diff --git a/src/vnet/mpls/mpls_lookup.h b/src/vnet/mpls/mpls_lookup.h
new file mode 100644
index 00000000000..6d3b04b8507
--- /dev/null
+++ b/src/vnet/mpls/mpls_lookup.h
@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2015 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.
+ */
+
+#ifndef __MPLS_LOOKUP_H__
+#define __MPLS_LOOKUP_H__
+
+#include <vnet/mpls/mpls.h>
+#include <vnet/ip/ip.h>
+
+/*
+ * Compute flow hash. 
+ * We'll use it to select which adjacency to use for this flow.  And other things.
+ */
+always_inline u32
+mpls_compute_flow_hash (const mpls_unicast_header_t * hdr,
+                        flow_hash_config_t flow_hash_config)
+{
+    return (vnet_mpls_uc_get_label(hdr->label_exp_s_ttl));
+}
+
+#endif /* __MPLS_LOOKUP_H__ */
diff --git a/test/test_mpls.py b/test/test_mpls.py
index fc832644a10..40ffcdc6342 100644
--- a/test/test_mpls.py
+++ b/test/test_mpls.py
@@ -735,6 +735,26 @@ class TestMPLS(VppTestCase):
         rx = self.pg1.get_capture(packet_count)
         self.verify_capture_ip4(self.pg1, rx, tx, ping_resp=1)
 
+        #
+        # Double pop
+        #
+        route_36_neos = VppMplsRoute(self, 36, 0,
+                                     [VppRoutePath("0.0.0.0",
+                                                   0xffffffff)])
+        route_36_neos.add_vpp_config()
+
+        self.vapi.cli("clear trace")
+        tx = self.create_stream_labelled_ip4(self.pg0, [36, 35],
+                                             ping=1, ip_itf=self.pg1)
+        self.pg0.add_stream(tx)
+
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+
+        rx = self.pg1.get_capture(len(tx))
+        self.verify_capture_ip4(self.pg1, rx, tx, ping_resp=1)
+
+        route_36_neos.remove_vpp_config()
         route_35_eos.remove_vpp_config()
         route_34_eos.remove_vpp_config()