/*
 * Copyright (c) 2021 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 __HICN_PG_H__
#define __HICN_PG_H__

#include <vppinfra/pool.h>

/**
 * @file pg.h
 *
 * The packet generator is made of two entities, a client and a server.
 * The client issues interests at high speed and the server satisfy each
 * interest it receives with the corresponding data.
 * The packet generator is made of three nodes:
 * - hicnpg-interest that receives packets from a packet generator interface
 *   and manipulate them to generate interests based on the given
 * configuration. This node runs at the client side.
 * - hicnpg-data that receives data packets at the client side and counts them.
 *   This is useful for statistics. The "show err" command will give the number
 *   of interest issued and data received at the client side
 * - hicnpg-server that recevies and interest and replies with the
 * corresponding data. The data is generated from the interest switching the
 * src and destination address in the packet and appending a payload to the
 * packet.
 *
 *
 * These three nodes are inserted in the vlib graph in the following manner:
 * - hicnpg-interest is added as a possible next node of the pg-input node. The
 * packet generator stream then specifies it as next node.
 * - hicnpg-data is added as next hop of the ip4/6-unicast node exploiting the
 * corresponding feature and it runs before the ip4/6-inacl node. In this way,
 * every packet that is received through an interface on which this feature is
 * enabled is sent to this node.
 * - hicnpg-server is added as next hop of the ip4/6-unicast using the
 * corresponding feature and it runs before the ip4/6-inacl node. In this way,
 * every packet that is received through an interface on which this feature is
 * enabled is sent to this node.
 *
 * An example of how to use the pg for hicn is available in the documentation.
 */

/**
 * @brief hICN packet generator main for the pg client nodes
 *
 * It stores the configuration and make it availables to the pg client nodes.
 */
typedef struct hicnpg_main_s
{
  /*
   * used to compute the sequence number
   */
  u32 index;

  /*
   * hICN name to put in the destination addess of an interest
   */
  fib_prefix_t *pgen_clt_hicn_name;

  /*
   * Used to mimic interests coming from different consumer. The source address
   * will change from interest to interest index_ifaces is used to keep a
   * global reference to the iface used and it is incremented when we want to
   * change "consumer"
   */
  u32 index_ifaces;

  /*
   * n_ifaces identifies how many consumers to simulate
   */
  u32 n_ifaces;

  /*
   * Use to limit the max sequence number
   */
  u32 max_seq_number;

  /*
   * Use to simulate multiple flows (a flow always have the same hICN name)
   */
  u32 n_flows;

  /*
   * Source addess base to use in the interest
   */
  ip46_address_t pgen_clt_src_addr;

  /*
   * Interest lifetime
   */
  u16 interest_lifetime;

  /*
   * Interface where to send interest and receives data.
   */
  u32 sw_if;

  /*
   * Fib node type
   */
  fib_node_type_t hicn_fib_node_type;
} hicnpg_main_t;

extern hicnpg_main_t hicnpg_main;

/**
 * @brief hICN packet generator main for the pg server node
 *
 * It stores the configuration and make it availables to the pg server node.
 */
typedef struct hicnpg_server_s
{
  /*
   * Prefix served by this packet generator server
   */
  fib_prefix_t prefix;

  /*
   * IP address to put in the destination addess of the data
   */
  ip46_address_t hicn_locator;

  /*
   * Buffer index
   */
  u32 buffer_index;

  /**
   * The DPO used to forward to the next node in the VLIB graph
   */
  dpo_id_t dpo;

  /*
   * linkage into the FIB graph
   */
  fib_node_t fib_node;

  /*
   * Tracking information for the IP destination
   */
  fib_node_index_t fib_entry_index;

  /*
   * The FIB index
   */
  index_t fib_index;
} hicnpg_server_t;

STATIC_ASSERT (sizeof (hicnpg_server_t) <= 2 * CLIB_CACHE_LINE_BYTES,
	       "hicnpg_server_t is too large");

extern hicnpg_server_t hicnpg_server_main;
extern vlib_node_registration_t hicn_pg_interest_node;
extern vlib_node_registration_t hicn_pg_data_node;
extern dpo_type_t hicnpg_server_dpo_type;

/**
 * Pool of hicnpg_servers
 */
extern hicnpg_server_t *hicnpg_server_pool;

always_inline hicnpg_server_t *
hicnpg_server_get (index_t hpgi)
{
  return pool_elt_at_index (hicnpg_server_pool, hpgi);
}

always_inline u8
dpo_is_pgserver (const dpo_id_t *dpo)
{
  return (dpo->dpoi_type == hicnpg_server_dpo_type);
}

clib_error_t *hicnpg_server_add_and_lock (fib_prefix_t *prefix,
					  u32 *hicnpg_server_index,
					  ip46_address_t *locator,
					  size_t payload_size);

clib_error_t *hicn_pg_init (vlib_main_t *vm);

#endif // __HICN_PG_H__

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */