text: /*
   * gre.h: types/functions for gre.
   *
   * Copyright (c) 2012 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 included_gre_h
  #define included_gre_h
  
  #include <vnet/vnet.h>
  #include <vnet/gre/packet.h>
  #include <vnet/ip/ip.h>
  #include <vnet/ip/ip4.h>
  #include <vnet/ip/ip4_packet.h>
  #include <vnet/pg/pg.h>
  #include <vnet/ip/format.h>
  #include <vnet/adj/adj_types.h>
  
  extern vnet_hw_interface_class_t gre_hw_interface_class;
  
  typedef enum {
  #define gre_error(n,s) GRE_ERROR_##n,
  #include <vnet/gre/error.def>
  #undef gre_error
    GRE_N_ERROR,
  } gre_error_t;
  
  typedef struct {
    /* Name (a c string). */
    char * name;
  
    /* GRE protocol type in host byte order. */
    gre_protocol_t protocol;
  
    /* Node which handles this type. */
    u32 node_index;
  
    /* Next index for this type. */
    u32 next_index;
  } gre_protocol_info_t;
  
  typedef struct {
    /**
     * Linkage into the FIB object graph
     */
    fib_node_t node;
  
    /**
     * The tunnel's source/local address
     */
    ip4_address_t tunnel_src;
    /**
     * The tunnel's destination/remote address
     */
    ip4_address_t tunnel_dst;
    /**
     * The FIB in which the src.dst address are present
     */
    u32 outer_fib_index;
    u32 hw_if_index;
    u32 sw_if_index;
    u8 teb;
  
    /**
     * The FIB entry sourced by the tunnel for its destination prefix
     */
    fib_node_index_t fib_entry_index;
  
    /**
     * The tunnel is a child of the FIB entry for its desintion. This is
     * so it receives updates when the forwarding information for that entry
     * changes.
     * The tunnels sibling index on the FIB entry's dependency list.
     */
    u32 sibling_index;
  
    /**
     * The index of the midchain adjacency created for this tunnel
     */
    adj_index_t adj_index[FIB_LINK_NUM];
  
    /**
     * on a L2 tunnel this is the VLIB arc from the L2-tx to the l2-midchain
     */
    u32 l2_tx_arc;
  } gre_tunnel_t;
  
  typedef struct {
    /* pool of tunnel instances */
    gre_tunnel_t *tunnels;
  
    gre_protocol_info_t * protocol_infos;
  
    /* Hash tables mapping name/protocol to protocol info index. */
    uword * protocol_info_by_name, * protocol_info_by_protocol;
    /* Hash mapping src/dst addr pair to tunnel */
    uword * tunnel_by_key;
  
    /* Free vlib hw_if_indices */
    u32 * free_gre_tunnel_hw_if_indices;
  
    /* Mapping from sw_if_index to tunnel index */
    u32 * tunnel_index_by_sw_if_index;
  
    /* convenience */
    vlib_main_t * vlib_main;
    vnet_main_t * vnet_main;
  } gre_main_t;
  
  /**
   * @brief IPv4 and GRE header.
   *
  */
  typedef CLIB_PACKED (struct {
    ip4_header_t ip4;
    gre_header_t gre;
  }) ip4_and_gre_header_t;
  
  always_inline gre_protocol_info_t *
  gre_get_protocol_info (gre_main_t * em, gre_protocol_t protocol)
  {
    uword * p = hash_get (em->protocol_info_by_protocol, protocol);
    return p ? vec_elt_at_index (em->protocol_infos, p[0]) : 0;
  }
  
  gre_main_t gre_main;
  
  /* Register given node index to take input for given gre type. */
  void
  gre_register_input_type (vlib_main_t * vm,
  			 gre_protocol_t protocol,
  			 u32 node_index);
  
  extern void gre_tunnel_stack (gre_tunnel_t *gt);
  
  format_function_t format_gre_protocol;
  format_function_t format_gre_header;
  format_function_t format_gre_header_with_length;
  
  extern vlib_node_registration_t gre_input_node;
  extern vnet_device_class_t gre_device_class;
  extern vnet_device_class_t gre_l2_device_class;
  
  /* Parse gre protocol as 0xXXXX or protocol name.
     In either host or network byte order. */
  unformat_function_t unformat_gre_protocol_host_byte_order;
  unformat_function_t unformat_gre_protocol_net_byte_order;
  
  /* Parse gre header. */
  unformat_function_t unformat_gre_header;
  unformat_function_t unformat_pg_gre_header;
  
  void
  gre_register_input_protocol (vlib_main_t * vm,
  			     gre_protocol_t protocol,
  			     u32 node_index);
  
  /* manually added to the interface output node in gre.c */
  #define GRE_OUTPUT_NEXT_LOOKUP	1
  
  typedef struct {
    u8 is_add;
  
    ip4_address_t src, dst;
    u32 outer_fib_id;
    u8 teb;
  } vnet_gre_add_del_tunnel_args_t;
  
  int vnet_gre_add_del_tunnel
    (vnet_gre_add_del_tunnel_args_t *a, u32 * sw_if_indexp);
  
  #endif /* included_gre_h */
  