text: /*
   * Copyright (c) 2016 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 __FIB_ENTRY_H__
  #define __FIB_ENTRY_H__
  
  #include <vnet/fib/fib_node.h>
  #include <vnet/fib/fib_entry_delegate.h>
  #include <vnet/adj/adj.h>
  #include <vnet/ip/ip.h>
  #include <vnet/dpo/dpo.h>
  
  /**
   * The different sources that can create a route.
   * The sources are defined here the thier relative priority order.
   * The lower the value the higher the priority
   */
  typedef enum fib_source_t_ {
      /**
       * Marker. Add new values after this one.
       */
      FIB_SOURCE_FIRST,
      /**
       * Special sources. These are for entries that are added to all
       * FIBs by default, and should never be over-ridden (hence they
       * are the highest priority)
       */
      FIB_SOURCE_SPECIAL = FIB_SOURCE_FIRST,
      /**
       * Classify. A route that links directly to a classify adj
       */
      FIB_SOURCE_CLASSIFY,
      /**
       * Route added as a result of interface configuration.
       * this will also come from the API/CLI, but the distinction is
       * that is from confiiguration on an interface, not a 'ip route' command
       */
      FIB_SOURCE_INTERFACE,
      /**
       * A high priority source a plugin can use
       */
      FIB_SOURCE_PLUGIN_HI,
      /**
       * From the control plane API
       */
      FIB_SOURCE_API,
      /**
       * From the CLI.
       */
      FIB_SOURCE_CLI,
      /**
       * LISP
       */
      FIB_SOURCE_LISP,
      /**
       * SRv6
       */
      FIB_SOURCE_SR,
      /**
       * IPv[46] Mapping
       */
      FIB_SOURCE_MAP,
      /**
       * SIXRD
       */
      FIB_SOURCE_SIXRD,
      /**
       * DHCP
       */
      FIB_SOURCE_DHCP,
      /**
       * Adjacency source.
       * routes created as a result of ARP/ND entries. This is lower priority
       * then the API/CLI. This is on purpose. trust me.
       */
      FIB_SOURCE_ADJ,
      /**
       * MPLS label. The prefix has been assigned a local label. This source
       * never provides forwarding information, instead it acts as a place-holder
       * so the association of label to prefix can be maintained
       */
      FIB_SOURCE_MPLS,
      /**
       * Attached Export source.
       * routes created as a result of attahced export. routes thus sourced
       * will be present in the export tables
       */
      FIB_SOURCE_AE,
      /**
       * Recursive resolution source.
       * Used to install an entry that is the resolution traget of another.
       */
      FIB_SOURCE_RR,
      /**
       * uRPF bypass/exemption.
       * Used to install an entry that is exempt from the loose uRPF check
       */
      FIB_SOURCE_URPF_EXEMPT,
      /**
       * The default route source.
       * The default route is always added to the FIB table (like the
       * special sources) but we need to be able to over-ride it with
       * 'ip route' sources when provided
       */
      FIB_SOURCE_DEFAULT_ROUTE,
      /**
       * Marker. add new entries before this one.
       */
      FIB_SOURCE_LAST = FIB_SOURCE_DEFAULT_ROUTE,
  } __attribute__ ((packed)) fib_source_t;
  
  STATIC_ASSERT (sizeof(fib_source_t) == 1,
  	       "FIB too many sources");
  
  /**
   * The maximum number of sources
   */
  #define FIB_SOURCE_MAX (FIB_SOURCE_LAST+1)
  
  #define FIB_SOURCES {					\
      [FIB_SOURCE_SPECIAL] = "special",			\
      [FIB_SOURCE_INTERFACE] = "interface",		\
      [FIB_SOURCE_API] = "API",			        \
      [FIB_SOURCE_CLI] = "CLI",			        \
      [FIB_SOURCE_ADJ] = "adjacency",			\
      [FIB_SOURCE_MAP] = "MAP",			        \
      [FIB_SOURCE_SR] = "SR",			        \
      [FIB_SOURCE_SIXRD] = "SixRD",			\
      [FIB_SOURCE_LISP] = "LISP", 			\
      [FIB_SOURCE_CLASSIFY] = "classify",			\
      [FIB_SOURCE_DHCP] = "DHCP",   			\
      [FIB_SOURCE_RR] = "recursive-resolution",	        \
      [FIB_SOURCE_AE] = "attached_export",	        \
      [FIB_SOURCE_MPLS] = "mpls",           	        \
      [FIB_SOURCE_URPF_EXEMPT] = "urpf-exempt",	        \
      [FIB_SOURCE_DEFAULT_ROUTE] = "default-route",	\
  }
  
  #define FOR_EACH_FIB_SOURCE(_item) \
      for (_item = FIB_SOURCE_FIRST; _item < FIB_SOURCE_MAX; _item++)
  
  /**
   * The different sources that can create a route.
   * The sources are defined here the thier relative priority order.
   * The lower the value the higher the priority
   */
  typedef enum fib_entry_attribute_t_ {
      /**
       * Marker. Add new values after this one.
       */
      FIB_ENTRY_ATTRIBUTE_FIRST,
      /**
       * Connected. The prefix is configured on an interface.
       */
      FIB_ENTRY_ATTRIBUTE_CONNECTED = FIB_ENTRY_ATTRIBUTE_FIRST,
      /**
       * Attached. The prefix is attached to an interface.
       */
      FIB_ENTRY_ATTRIBUTE_ATTACHED,
      /**
       * The route is an explicit drop.
       */
      FIB_ENTRY_ATTRIBUTE_DROP,
      /**
       * The route is exclusive. The client creating the route is
       * providing an exclusive adjacency.
       */
      FIB_ENTRY_ATTRIBUTE_EXCLUSIVE,
      /**
       * The route is attached cross tables and thus imports covered
       * prefixes from the other table.
       */
      FIB_ENTRY_ATTRIBUTE_IMPORT,
      /**
       * The prefix/address is local to this device
       */
      FIB_ENTRY_ATTRIBUTE_LOCAL,
      /**
       * Marker. add new entries before this one.
       */
      FIB_ENTRY_ATTRIBUTE_LAST = FIB_ENTRY_ATTRIBUTE_LOCAL,
  } fib_entry_attribute_t;
  
  /**
   * The maximum number of sources
   */
  #define FIB_ENTRY_ATTRIBUTE_MAX (FIB_ENTRY_ATTRIBUTE_LAST+1)
  
  #define FIB_ENTRY_ATTRIBUTES {		       		\
      [FIB_ENTRY_ATTRIBUTE_CONNECTED] = "connected",	\
      [FIB_ENTRY_ATTRIBUTE_ATTACHED]  = "attached",	\
      [FIB_ENTRY_ATTRIBUTE_IMPORT]    = "import",	        \
      [FIB_ENTRY_ATTRIBUTE_DROP]      = "drop",		\
      [FIB_ENTRY_ATTRIBUTE_EXCLUSIVE] = "exclusive",      \
      [FIB_ENTRY_ATTRIBUTE_LOCAL]     = "local",		\
  }
  
  #define FOR_EACH_FIB_ATTRIBUTE(_item)			\
      for (_item = FIB_ENTRY_ATTRIBUTE_FIRST;		\
  	 _item < FIB_ENTRY_ATTRIBUTE_MAX;		\
  	 _item++)
  
  typedef enum fib_entry_flag_t_ {
      FIB_ENTRY_FLAG_NONE      = 0,
      FIB_ENTRY_FLAG_CONNECTED = (1 << FIB_ENTRY_ATTRIBUTE_CONNECTED),
      FIB_ENTRY_FLAG_ATTACHED  = (1 << FIB_ENTRY_ATTRIBUTE_ATTACHED),
      FIB_ENTRY_FLAG_DROP      = (1 << FIB_ENTRY_ATTRIBUTE_DROP),
      FIB_ENTRY_FLAG_EXCLUSIVE = (1 << FIB_ENTRY_ATTRIBUTE_EXCLUSIVE),
      FIB_ENTRY_FLAG_LOCAL     = (1 << FIB_ENTRY_ATTRIBUTE_LOCAL),
      FIB_ENTRY_FLAG_IMPORT    = (1 << FIB_ENTRY_ATTRIBUTE_IMPORT),
  } fib_entry_flag_t;
  
  /**
   * Flags for the source data
   */
  typedef enum fib_entry_src_attribute_t_ {
      /**
       * Marker. Add new values after this one.
       */
      FIB_ENTRY_SRC_ATTRIBUTE_FIRST,
      /**
       * the source has been added to the entry
       */
      FIB_ENTRY_SRC_ATTRIBUTE_ADDED = FIB_ENTRY_SRC_ATTRIBUTE_FIRST,
      /**
       * the source is active/best
       */
      FIB_ENTRY_SRC_ATTRIBUTE_ACTIVE,
      /**
       * Marker. add new entries before this one.
       */
      FIB_ENTRY_SRC_ATTRIBUTE_LAST = FIB_ENTRY_SRC_ATTRIBUTE_ACTIVE,
  } fib_entry_src_attribute_t;
  
  #define FIB_ENTRY_SRC_ATTRIBUTE_MAX (FIB_ENTRY_SRC_ATTRIBUTE_LAST+1)
  
  #define FIB_ENTRY_SRC_ATTRIBUTES {		 \
      [FIB_ENTRY_SRC_ATTRIBUTE_ADDED]  = "added",	 \
      [FIB_ENTRY_SRC_ATTRIBUTE_ACTIVE] = "active", \
  }
  
  typedef enum fib_entry_src_flag_t_ {
      FIB_ENTRY_SRC_FLAG_NONE   = 0,
      FIB_ENTRY_SRC_FLAG_ADDED  = (1 << FIB_ENTRY_SRC_ATTRIBUTE_ADDED),
      FIB_ENTRY_SRC_FLAG_ACTIVE = (1 << FIB_ENTRY_SRC_ATTRIBUTE_ACTIVE),
  } __attribute__ ((packed)) fib_entry_src_flag_t;
  
  /*
   * Keep the size of the flags field to 2 bytes, so it
   * can be placed next to the 2 bytes reference count
   */
  STATIC_ASSERT (sizeof(fib_entry_src_flag_t) <= 2,
  	       "FIB entry flags field size too big");
  
  /**
   * Information related to the source of a FIB entry
   */
  typedef struct fib_entry_src_t_ {
      /**
       * A vector of path extensions
       */
      struct fib_path_ext_t_ *fes_path_exts;
  
      /**
       * The path-list created by the source
       */
      fib_node_index_t fes_pl;
      /**
       * Which source this info block is for
       */
      fib_source_t fes_src;
      /**
       * Flags on the source
       */
      fib_entry_src_flag_t fes_flags;
  
      /**
       * 1 bytes ref count. This is not the number of users of the Entry
       * (which is itself not large, due to path-list sharing), but the number
       * of times a given source has been added. Which is even fewer
       */
      u8 fes_ref_count;
  
      /**
       * Flags the source contributes to the entry
       */
      fib_entry_flag_t fes_entry_flags;
      
      /**
       * Source specific info
       */
      union {
  	struct {
  	    /**
  	     * the index of the FIB entry that is the covering entry
  	     */
  	    fib_node_index_t fesr_cover;
  	    /**
  	     * This source's index in the cover's list
  	     */
  	    u32 fesr_sibling;
  	} rr;
  	struct {
  	    /**
  	     * the index of the FIB entry that is the covering entry
  	     */
  	    fib_node_index_t fesa_cover;
  	    /**
  	     * This source's index in the cover's list
  	     */
  	    u32 fesa_sibling;
  	} adj;
  	struct {
  	    /**
  	     * the index of the FIB entry that is the covering entry
  	     */
  	    fib_node_index_t fesi_cover;
  	    /**
  	     * This source's index in the cover's list
  	     */
  	    u32 fesi_sibling;
  	} interface;
  	struct {
  	    /**
  	     * This MPLS local label associated with the prefix.
  	     */
  	    mpls_label_t fesm_label;
  
  	    /**
  	     * the indicies of the LFIB entries created
  	     */
  	    fib_node_index_t fesm_lfes[2];
  	} mpls;
  	struct {
  	    /**
  	     * The source FIB index.
  	     */
              fib_node_index_t fesl_fib_index;
  	} lisp;
      };
  } fib_entry_src_t;
  
  /**
   * An entry in a FIB table.
   *
   * This entry represents a route added to the FIB that is stored
   * in one of the FIB tables.
   */
  typedef struct fib_entry_t_ {
      /**
       * Base class. The entry's node representation in the graph.
       */
      fib_node_t fe_node;
      /**
       * The prefix of the route. this is const just to be sure.
       * It is the entry's key/identity and so should never change.
       */
      const fib_prefix_t fe_prefix;
      /**
       * The index of the FIB table this entry is in
       */
      u32 fe_fib_index;
      /**
       * The load-balance used for forwarding.
       *
       * We don't share the EOS and non-EOS even in case when they could be
       * because:
       *   - complexity & reliability v. memory
       *       determining the conditions where sharing is possible is non-trivial.
       *   - separate LBs means we can get the EOS bit right in the MPLS label DPO
       *     and so save a few clock cycles in the DP imposition node since we can
       *     paint the header straight on without the need to check the packet
       *     type to derive the EOS bit value.
       */
      dpo_id_t fe_lb; // [FIB_FORW_CHAIN_MPLS_NUM];
      /**
       * Vector of source infos.
       * Most entries will only have 1 source. So we optimise for memory usage,
       * which is preferable since we have many entries.
       */
      fib_entry_src_t *fe_srcs;
      /**
       * the path-list for which this entry is a child. This is also the path-list
       * that is contributing forwarding for this entry.
       */
      fib_node_index_t fe_parent;
      /**
       * index of this entry in the parent's child list.
       * This is set when this entry is added as a child, but can also
       * be changed by the parent as it manages its list.
       */
      u32 fe_sibling;
  
      /**
       * A vector of delegates.
       */
      fib_entry_delegate_t *fe_delegates;
  } fib_entry_t;
  
  #define FOR_EACH_FIB_ENTRY_FLAG(_item) \
      for (_item = FIB_ENTRY_FLAG_FIRST; _item < FIB_ENTRY_FLAG_MAX; _item++)
  
  #define FIB_ENTRY_FORMAT_BRIEF   (0x0)
  #define FIB_ENTRY_FORMAT_DETAIL  (0x1)
  #define FIB_ENTRY_FORMAT_DETAIL2 (0x2)
  
  extern u8 *format_fib_entry (u8 * s, va_list * args);
  
  extern fib_node_index_t fib_entry_create_special(u32 fib_index,
  						 const fib_prefix_t *prefix,
  						 fib_source_t source,
  						 fib_entry_flag_t flags,
  						 const dpo_id_t *dpo);
  
  extern fib_node_index_t fib_entry_create (u32 fib_index,
  					  const fib_prefix_t *prefix,
  					  fib_source_t source,
  					  fib_entry_flag_t flags,
  					  const fib_route_path_t *paths);
  extern void fib_entry_update (fib_node_index_t fib_entry_index,
  			      fib_source_t source,
  			      fib_entry_flag_t flags,
  			      const fib_route_path_t *paths);
  
  extern void fib_entry_path_add(fib_node_index_t fib_entry_index,
  			       fib_source_t source,
  			       fib_entry_flag_t flags,
  			       const fib_route_path_t *rpath);
  extern void fib_entry_special_add(fib_node_index_t fib_entry_index,
  				  fib_source_t source,
  				  fib_entry_flag_t flags,
  				  const dpo_id_t *dpo);
  extern void fib_entry_special_update(fib_node_index_t fib_entry_index,
  				     fib_source_t source,
  				     fib_entry_flag_t flags,
  				     const dpo_id_t *dpo);
  extern fib_entry_src_flag_t fib_entry_special_remove(fib_node_index_t fib_entry_index,
  						     fib_source_t source);
  
  extern fib_entry_src_flag_t fib_entry_path_remove(fib_node_index_t fib_entry_index,
  						  fib_source_t source,
  						  const fib_route_path_t *rpath);
  extern fib_entry_src_flag_t fib_entry_delete(fib_node_index_t fib_entry_index,
  					     fib_source_t source);
  
  extern void fib_entry_contribute_urpf(fib_node_index_t path_index,
  				      index_t urpf);
  extern void fib_entry_contribute_forwarding(
      fib_node_index_t fib_entry_index,
      fib_forward_chain_type_t type,
      dpo_id_t *dpo);
  extern const dpo_id_t * fib_entry_contribute_ip_forwarding(
      fib_node_index_t fib_entry_index);
  extern adj_index_t fib_entry_get_adj_for_source(
      fib_node_index_t fib_entry_index,
      fib_source_t source);
  extern const int fib_entry_get_dpo_for_source (
      fib_node_index_t fib_entry_index,
      fib_source_t source,
      dpo_id_t *dpo);
  
  extern adj_index_t fib_entry_get_adj(fib_node_index_t fib_entry_index);
  
  extern int fib_entry_cmp_for_sort(void *i1, void *i2);
  
  extern void fib_entry_cover_changed(fib_node_index_t fib_entry);
  extern void fib_entry_cover_updated(fib_node_index_t fib_entry);
  extern int fib_entry_recursive_loop_detect(fib_node_index_t entry_index,
  					   fib_node_index_t **entry_indicies);
  
  extern void fib_entry_lock(fib_node_index_t fib_entry_index);
  extern void fib_entry_unlock(fib_node_index_t fib_entry_index);
  
  extern u32 fib_entry_child_add(fib_node_index_t fib_entry_index,
  			       fib_node_type_t type,
  			       fib_node_index_t child_index);
  extern void fib_entry_child_remove(fib_node_index_t fib_entry_index,
  				   u32 sibling_index);
  extern u32 fib_entry_get_resolving_interface(fib_node_index_t fib_entry_index);
  extern u32 fib_entry_get_resolving_interface_for_source(
      fib_node_index_t fib_entry_index,
      fib_source_t source);
  
  extern void fib_entry_encode(fib_node_index_t fib_entry_index,
  			     fib_route_path_encode_t **api_rpaths);
  extern void fib_entry_get_prefix(fib_node_index_t fib_entry_index,
  				 fib_prefix_t *pfx);
  extern u32 fib_entry_get_fib_index(fib_node_index_t fib_entry_index);
  extern void fib_entry_set_source_data(fib_node_index_t fib_entry_index,
                                        fib_source_t source,
                                        const void *data);
  extern const void* fib_entry_get_source_data(fib_node_index_t fib_entry_index,
                                               fib_source_t source);
  
  extern fib_entry_flag_t fib_entry_get_flags(fib_node_index_t fib_entry_index);
  extern fib_entry_flag_t fib_entry_get_flags_for_source(
      fib_node_index_t fib_entry_index,
      fib_source_t source);
  extern fib_source_t fib_entry_get_best_source(fib_node_index_t fib_entry_index);
  extern int fib_entry_is_sourced(fib_node_index_t fib_entry_index,
                                  fib_source_t source);
  
  extern fib_node_index_t fib_entry_get_path_list(fib_node_index_t fib_entry_index);
  
  extern void fib_entry_module_init(void);
  
  /*
   * unsafe... beware the raw pointer.
   */
  extern fib_node_index_t fib_entry_get_index(const fib_entry_t * fib_entry);
  extern fib_entry_t * fib_entry_get(fib_node_index_t fib_entry_index);
  
  /*
   * for testing purposes.
   */
  extern u32 fib_entry_pool_size(void);
  
  #endif
  