[HICN-574] Host stack plugin for VPP.

Signed-off-by: Mauro Sardara <msardara@cisco.com>
Change-Id: I8d8fdffef31a7013265d6529c5f52f3d5ec70d18
Signed-off-by: Mauro Sardara <msardara@cisco.com>
Signed-off-by: Mauro <you@example.com>
Signed-off-by: Mauro Sardara <msardara@cisco.com>

1 files changed, 178 insertions, 0 deletions

diff --git a/hicn-plugin/src/host_stack/route.c b/hicn-plugin/src/host_stack/route.c
new file mode 100644
index 000000000..5b42bea26
--- /dev/null
+++ b/hicn-plugin/src/host_stack/route.c
@@ -0,0 +1,178 @@
+/*
+ * Copyright (c) 2020 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 "host_stack.h"
+#include "route.h"
+
+#include <vnet/fib/fib_entry.h>
+#include <vnet/fib/fib_table.h>
+#include <vnet/ip/ip6_packet.h>
+#include <vnet/dpo/dpo.h>
+#include <vnet/dpo/load_balance.h>
+#include <vlib/global_funcs.h>
+#include <vnet/dpo/drop_dpo.h>
+
+#define FIB_SOURCE_HICN_HS 0x04	//Right after the FIB_SOURCE_INTERFACE priority
+#define HICN_HS_FIB_TABLE 0
+
+fib_source_t hicn_hs_fib_src;
+
+void
+hicn_hs_route_init ()
+{
+  hicn_hs_fib_src = fib_source_allocate ("hicn_hs", FIB_SOURCE_HICN_HS, FIB_SOURCE_BH_API);
+}
+
+always_inline int
+hicn_route_get_dpo (const fib_prefix_t * prefix,
+		    const dpo_id_t ** hicn_dpo, u32 * fib_index)
+{
+  //fib_prefix_t fib_pfx;
+  const dpo_id_t *load_balance_dpo_id;
+  const dpo_id_t *former_dpo_id;
+  int found = 0, ret = HICN_HS_ERROR_ROUTE_NOT_FOUND;
+  fib_node_index_t fib_entry_index;
+
+  /* Check if the route already exist in the fib */
+  /*
+   * ASSUMPTION: we use table 0 which is the default table and it is
+   * already existing and locked
+   */
+  *fib_index = fib_table_find_or_create_and_lock (prefix->fp_proto,
+						  HICN_HS_FIB_TABLE,
+						  hicn_hs_fib_src);
+  fib_entry_index = fib_table_lookup_exact_match (*fib_index, prefix);
+
+  if (fib_entry_index != FIB_NODE_INDEX_INVALID)
+    {
+      /* Route already existing. We need to update the dpo. */
+      load_balance_dpo_id =
+	fib_entry_contribute_ip_forwarding (fib_entry_index);
+
+      /* The dpo is not a load balance dpo as expected */
+      if (load_balance_dpo_id->dpoi_type != DPO_LOAD_BALANCE)
+	ret = HICN_HS_ERROR_ROUTE_NO_LB_DPO;
+      else
+	{
+	  /* former_dpo_id is a load_balance dpo */
+	  load_balance_t *lb =
+	    load_balance_get (load_balance_dpo_id->dpoi_index);
+
+	  /* FIB entry exists but there is no hicn_hs dpo. */
+	  ret = HICN_HS_ERROR_ROUTE_DPO_NO_HICN;
+	  for (int i = 0; i < lb->lb_n_buckets && !found; i++)
+	    {
+	      former_dpo_id = load_balance_get_bucket_i (lb, i);
+
+	      if (dpo_is_hicn_hs (former_dpo_id))
+		{
+		  *hicn_dpo = former_dpo_id;
+		  ret = HICN_HS_ERROR_NONE;
+		  found = 1;
+		}
+	    }
+	}
+    }
+  /*
+   * Remove the lock from the table. We keep one lock per route, not
+   * per dpo
+   */
+  fib_table_unlock (*fib_index, prefix->fp_proto, hicn_hs_fib_src);
+
+  return ret;
+}
+
+/* Add a new route for a name prefix */
+always_inline
+int hicn_hs_route_add_flags (const fib_prefix_t * prefix, const dpo_id_t *dpo, fib_entry_flag_t flags)
+{
+  CLIB_UNUSED(vlib_main_t *vm) = vlib_get_main ();
+  int ret = HICN_HS_ERROR_NONE;
+  u32 fib_index;
+  const dpo_id_t *_dpo;
+
+  ret = hicn_route_get_dpo (prefix, &_dpo, &fib_index);
+
+  if (ret == HICN_HS_ERROR_ROUTE_NOT_FOUND)
+    {
+      /* Here is where we create the "via" like route */
+      /*
+       * For the moment we use the global one the prefix you want
+       * to match Neale suggested -- FIB_SOURCE_HICN the client
+       * that is adding them -- no easy explanation at this time…
+       */
+      fib_node_index_t new_fib_node_index =
+	fib_table_entry_special_dpo_add (fib_index,
+					 prefix,
+					 hicn_hs_fib_src,
+					 flags,
+					 dpo);
+
+      /* We added a route, therefore add one lock to the table */
+      fib_table_lock (fib_index, prefix->fp_proto, hicn_hs_fib_src);
+
+      ret =
+	(new_fib_node_index !=
+	 FIB_NODE_INDEX_INVALID) ? HICN_HS_ERROR_NONE :
+	HICN_HS_ERROR_ROUTE_NO_INSERT;
+    }
+
+  return ret;
+}
+
+int
+hicn_hs_route_add (const fib_prefix_t * prefix, const dpo_id_t *dpo)
+{
+  return hicn_hs_route_add_flags(prefix, dpo, (FIB_ENTRY_FLAG_EXCLUSIVE |
+					       FIB_ENTRY_FLAG_LOOSE_URPF_EXEMPT));
+}
+
+clib_error_t *
+hicn_hs_set_local_prefix(const fib_prefix_t * prefix)
+{
+  clib_error_t * ret = 0;
+  int rv;
+  const dpo_id_t *drop_dpo = drop_dpo_get(prefix->fp_proto == FIB_PROTOCOL_IP4 ? DPO_PROTO_IP4 : DPO_PROTO_IP6);
+  rv = hicn_hs_route_add_flags(prefix, drop_dpo, (FIB_ENTRY_FLAG_EXCLUSIVE | FIB_ENTRY_FLAG_LOCAL | FIB_ENTRY_FLAG_LOOSE_URPF_EXEMPT));
+
+  if (rv)
+    ret = clib_error_return (0, "Error: %s", hicn_hs_error_strings[rv]);
+  
+  return ret;
+}
+
+int
+hicn_route_del (fib_prefix_t * prefix)
+{
+  const dpo_id_t *hicn_dpo_id;
+  int ret = HICN_HS_ERROR_NONE;
+  u32 fib_index;
+
+  /* Remove the fib entry only if the dpo is of type hicn */
+  ret = hicn_route_get_dpo (prefix, &hicn_dpo_id, &fib_index);
+
+  if (ret == HICN_HS_ERROR_NONE)
+    {
+      fib_table_entry_special_remove (HICN_HS_FIB_TABLE, prefix, hicn_hs_fib_src);
+
+      /*
+       * Remove the lock from the table. We keep one lock per route
+       */
+      fib_table_unlock (fib_index, prefix->fp_proto, hicn_hs_fib_src);
+    }
+  
+  // Remember to remove the lock from the table when removing the entry
+  return ret;
+}
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