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/*
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 *        BIRD Internet Routing Daemon -- Routing Table
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 *
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 *        (c) 1998--2000 Martin Mares <mj@ucw.cz>
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 *
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 *        Can be freely distributed and used under the terms of the GNU GPL.
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 */
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#ifndef _BIRD_ROUTE_H_
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#define _BIRD_ROUTE_H_
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#include "lib/lists.h"
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#include "lib/resource.h"
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#include "lib/timer.h"
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struct protocol;
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struct proto;
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struct symbol;
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struct filter;
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struct cli;
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/*
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 *        Generic data structure for storing network prefixes. Also used
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 *        for the master routing table. Currently implemented as a hash
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 *        table.
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 *
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 *        Available operations:
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 *                - insertion of new entry
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 *                - deletion of entry
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 *                - searching for entry by network prefix
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 *                - asynchronous retrieval of fib contents
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 */
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struct fib_node {
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  struct fib_node *next;                /* Next in hash chain */
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  struct fib_iterator *readers;                /* List of readers of this node */
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  byte pxlen;
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  byte flags;                                /* User-defined */
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  byte x0, x1;                                /* User-defined */
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  u32 uid;                                /* Unique ID based on hash */
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  ip_addr prefix;                        /* In host order */
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};
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struct fib_iterator {                        /* See lib/slists.h for an explanation */
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  struct fib_iterator *prev, *next;        /* Must be synced with struct fib_node! */
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  byte efef;                                /* 0xff to distinguish between iterator and node */
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  byte pad[3];
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  struct fib_node *node;                /* Or NULL if freshly merged */
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  unsigned int hash;
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};
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typedef void (*fib_init_func)(struct fib_node *);
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struct fib {
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  pool *fib_pool;                        /* Pool holding all our data */
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  slab *fib_slab;                        /* Slab holding all fib nodes */
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  struct fib_node **hash_table;                /* Node hash table */
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  unsigned int hash_size;                /* Number of hash table entries (a power of two) */
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  unsigned int hash_order;                /* Binary logarithm of hash_size */
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  unsigned int hash_shift;                /* 16 - hash_log */
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  unsigned int entries;                        /* Number of entries */
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  unsigned int entries_min, entries_max;/* Entry count limits (else start rehashing) */
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  fib_init_func init;                        /* Constructor */
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};
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void fib_init(struct fib *, pool *, unsigned node_size, unsigned hash_order, fib_init_func init);
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void *fib_find(struct fib *, ip_addr *, int);        /* Find or return NULL if doesn't exist */
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void *fib_get(struct fib *, ip_addr *, int);         /* Find or create new if nonexistent */
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void *fib_route(struct fib *, ip_addr, int);        /* Longest-match routing lookup */
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void fib_delete(struct fib *, void *);        /* Remove fib entry */
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void fib_free(struct fib *);                /* Destroy the fib */
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void fib_check(struct fib *);                /* Consistency check for debugging */
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void fit_init(struct fib_iterator *, struct fib *); /* Internal functions, don't call */
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struct fib_node *fit_get(struct fib *, struct fib_iterator *);
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void fit_put(struct fib_iterator *, struct fib_node *);
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#define FIB_WALK(fib, z) do {                                        \
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        struct fib_node *z, **ff = (fib)->hash_table;                \
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        unsigned int count = (fib)->hash_size;                        \
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        while (count--)                                                \
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          for(z = *ff++; z; z=z->next)
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#define FIB_WALK_END } while (0)
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#define FIB_ITERATE_INIT(it, fib) fit_init(it, fib)
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#define FIB_ITERATE_START(fib, it, z) do {                        \
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        struct fib_node *z = fit_get(fib, it);                        \
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        unsigned int count = (fib)->hash_size;                        \
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        unsigned int hpos = (it)->hash;                                \
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        for(;;) {                                                \
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          if (!z)                                                \
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            {                                                        \
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               if (++hpos >= count)                                \
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                 break;                                                \
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               z = (fib)->hash_table[hpos];                        \
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               continue;                                        \
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            }
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#define FIB_ITERATE_END(z) z = z->next; } } while(0)
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#define FIB_ITERATE_PUT(it, z) fit_put(it, z)
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/*
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 *        Master Routing Tables. Generally speaking, each of them contains a FIB
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 *        with each entry pointing to a list of route entries representing routes
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 *        to given network (with the selected one at the head).
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 *
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 *        Each of the RTE's contains variable data (the preference and protocol-dependent
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 *        metrics) and a pointer to a route attribute block common for many routes).
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 *
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 *        It's guaranteed that there is at most one RTE for every (prefix,proto) pair.
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 */
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struct rtable_config {
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  node n;
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  char *name;
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  struct rtable *table;
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  struct proto_config *krt_attached;        /* Kernel syncer attached to this table */
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  int gc_max_ops;                        /* Maximum number of operations before GC is run */
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  int gc_min_time;                        /* Minimum time between two consecutive GC runs */
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};
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typedef struct rtable {
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  node n;                                /* Node in list of all tables */
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  struct fib fib;
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  char *name;                                /* Name of this table */
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  list hooks;                                /* List of announcement hooks */
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  int pipe_busy;                        /* Pipe loop detection */
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  int use_count;                        /* Number of protocols using this table */
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  struct hostcache *hostcache;
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  struct rtable_config *config;                /* Configuration of this table */
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  struct config *deleted;                /* Table doesn't exist in current configuration,
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                                         * delete as soon as use_count becomes 0 and remove
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                                         * obstacle from this routing table.
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                                         */
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  struct event *rt_event;                /* Routing table event */
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  int gc_counter;                        /* Number of operations since last GC */
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  bird_clock_t gc_time;                        /* Time of last GC */
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  byte gc_scheduled;                        /* GC is scheduled */
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  byte hcu_scheduled;                        /* Hostcache update is scheduled */
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  byte nhu_state;                        /* Next Hop Update state */
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  struct fib_iterator nhu_fit;                /* Next Hop Update FIB iterator */
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} rtable;
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typedef struct network {
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  struct fib_node n;                        /* FIB flags reserved for kernel syncer */
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  struct rte *routes;                        /* Available routes for this network */
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} net;
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struct hostcache {
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  slab *slab;                                /* Slab holding all hostentries */
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  struct hostentry **hash_table;        /* Hash table for hostentries */
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  unsigned hash_order, hash_shift;
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  unsigned hash_max, hash_min;
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  unsigned hash_items;
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  linpool *lp;                                /* Linpool for trie */
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  struct f_trie *trie;                        /* Trie of prefixes that might affect hostentries */
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  list hostentries;                        /* List of all hostentries */
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  byte update_hostcache;
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};
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struct hostentry {
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  node ln;
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  ip_addr addr;                                /* IP address of host, part of key */
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  ip_addr link;                                /* (link-local) IP address of host, used as gw
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                                           if host is directly attached */
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  struct rtable *tab;                        /* Dependent table, part of key*/
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  struct hostentry *next;                /* Next in hash chain */
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  unsigned hash_key;                        /* Hash key */
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  unsigned uc;                                /* Use count */
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  struct rta *src;                        /* Source rta entry */
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  ip_addr gw;                                /* Chosen next hop */
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  byte dest;                                /* Chosen route destination type (RTD_...) */
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  u32 igp_metric;                        /* Chosen route IGP metric */
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};
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typedef struct rte {
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  struct rte *next;
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  net *net;                                /* Network this RTE belongs to */
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  struct proto *sender;                        /* Protocol instance that sent the route to the routing table */
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  struct rta *attrs;                        /* Attributes of this route */
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  byte flags;                                /* Flags (REF_...) */
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  byte pflags;                                /* Protocol-specific flags */
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  word pref;                                /* Route preference */
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  bird_clock_t lastmod;                        /* Last modified */
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  union {                                /* Protocol-dependent data (metrics etc.) */
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#ifdef CONFIG_RIP
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    struct {
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      node garbage;                        /* List for garbage collection */
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      byte metric;                        /* RIP metric */
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      u16 tag;                                /* External route tag */
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      struct rip_entry *entry;
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    } rip;
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#endif
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#ifdef CONFIG_OSPF
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    struct {
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      u32 metric1, metric2;                /* OSPF Type 1 and Type 2 metrics */
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      u32 tag;                                /* External route tag */
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      u32 router_id;                        /* Router that originated this route */
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    } ospf;
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#endif
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    struct {                                /* Routes generated by krt sync (both temporary and inherited ones) */
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      s8 src;                                /* Alleged route source (see krt.h) */
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      u8 proto;                                /* Kernel source protocol ID */
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      u8 type;                                /* Kernel route type */
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      u8 seen;                                /* Seen during last scan */
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      u32 metric;                        /* Kernel metric */
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    } krt;
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  } u;
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} rte;
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#define REF_COW 1                        /* Copy this rte on write */
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/* Types of route announcement, also used as flags */
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#define RA_OPTIMAL 1                        /* Announcement of optimal route change */
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#define RA_ANY 2                        /* Announcement of any route change */
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struct config;
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void rt_init(void);
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void rt_preconfig(struct config *);
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void rt_commit(struct config *new, struct config *old);
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void rt_lock_table(rtable *);
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void rt_unlock_table(rtable *);
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void rt_setup(pool *, rtable *, char *, struct rtable_config *);
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static inline net *net_find(rtable *tab, ip_addr addr, unsigned len) { return (net *) fib_find(&tab->fib, &addr, len); }
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static inline net *net_get(rtable *tab, ip_addr addr, unsigned len) { return (net *) fib_get(&tab->fib, &addr, len); }
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rte *rte_find(net *net, struct proto *p);
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rte *rte_get_temp(struct rta *);
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void rte_update(rtable *tab, net *net, struct proto *p, struct proto *src, rte *new);
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void rte_discard(rtable *tab, rte *old);
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void rte_dump(rte *);
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void rte_free(rte *);
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rte *rte_do_cow(rte *);
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static inline rte * rte_cow(rte *r) { return (r->flags & REF_COW) ? rte_do_cow(r) : r; }
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void rt_dump(rtable *);
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void rt_dump_all(void);
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int rt_feed_baby(struct proto *p);
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void rt_feed_baby_abort(struct proto *p);
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void rt_prune_all(void);
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struct rtable_config *rt_new_table(struct symbol *s);
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struct rt_show_data {
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  ip_addr prefix;
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  unsigned pxlen;
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  rtable *table;
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  struct filter *filter;
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  int verbose;
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  struct fib_iterator fit;
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  struct proto *show_protocol;
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  struct proto *export_protocol;
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  int export_mode, primary_only;
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  struct config *running_on_config;
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  int net_counter, rt_counter, show_counter;
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  int stats, show_for;
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};
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void rt_show(struct rt_show_data *);
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/*
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 *        Route Attributes
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 *
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 *        Beware: All standard BGP attributes must be represented here instead
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 *        of making them local to the route. This is needed to ensure proper
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 *        construction of BGP route attribute lists.
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 */
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/* Multipath next-hop */
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struct mpnh {
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  ip_addr gw;                                /* Next hop */
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  struct iface *iface;                        /* Outgoing interface */
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  struct mpnh *next;
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  unsigned char weight;
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};
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typedef struct rta {
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  struct rta *next, **pprev;                /* Hash chain */
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  struct proto *proto;                        /* Protocol instance that originally created the route */
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  unsigned uc;                                /* Use count */
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  byte source;                                /* Route source (RTS_...) */
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  byte scope;                                /* Route scope (SCOPE_... -- see ip.h) */
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  byte cast;                                /* Casting type (RTC_...) */
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  byte dest;                                /* Route destination type (RTD_...) */
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  byte flags;                                /* Route flags (RTF_...), now unused */
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  byte aflags;                                /* Attribute cache flags (RTAF_...) */
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  u16 hash_key;                                /* Hash over important fields */
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  u32 igp_metric;                        /* IGP metric to next hop (for iBGP routes) */
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  ip_addr gw;                                /* Next hop */
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  ip_addr from;                                /* Advertising router */
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  struct hostentry *hostentry;                /* Hostentry for recursive next-hops */
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  struct iface *iface;                        /* Outgoing interface */
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  struct mpnh *nexthops;                /* Next-hops for multipath routes */
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  struct ea_list *eattrs;                /* Extended Attribute chain */
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} rta;
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#define RTS_DUMMY 0                        /* Dummy route to be removed soon */
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#define RTS_STATIC 1                        /* Normal static route */
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#define RTS_INHERIT 2                        /* Route inherited from kernel */
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#define RTS_DEVICE 3                        /* Device route */
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#define RTS_STATIC_DEVICE 4                /* Static device route */
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#define RTS_REDIRECT 5                        /* Learned via redirect */
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#define RTS_RIP 6                        /* RIP route */
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#define RTS_OSPF 7                        /* OSPF route */
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#define RTS_OSPF_IA 8                        /* OSPF inter-area route */
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#define RTS_OSPF_EXT1 9                        /* OSPF external route type 1 */
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#define RTS_OSPF_EXT2 10                /* OSPF external route type 2 */
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#define RTS_BGP 11                        /* BGP route */
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#define RTS_PIPE 12                        /* Inter-table wormhole */
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#define RTC_UNICAST 0
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#define RTC_BROADCAST 1
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#define RTC_MULTICAST 2
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#define RTC_ANYCAST 3                        /* IPv6 Anycast */
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#define RTD_ROUTER 0                        /* Next hop is neighbor router */
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#define RTD_DEVICE 1                        /* Points to device */
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#define RTD_BLACKHOLE 2                        /* Silently drop packets */
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#define RTD_UNREACHABLE 3                /* Reject as unreachable */
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#define RTD_PROHIBIT 4                        /* Administratively prohibited */
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#define RTD_MULTIPATH 5                        /* Multipath route (nexthops != NULL) */
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#define RTD_NONE 6                        /* Invalid RTD */
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#define RTAF_CACHED 1                        /* This is a cached rta */
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#define IGP_METRIC_UNKNOWN 0x80000000        /* Default igp_metric used when no other
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                                           protocol-specific metric is availabe */
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/*
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 *        Extended Route Attributes
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 */
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typedef struct eattr {
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  word id;                                /* EA_CODE(EAP_..., protocol-dependent ID) */
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  byte flags;                                /* Protocol-dependent flags */
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  byte type;                                /* Attribute type and several flags (EAF_...) */
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  union {
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    u32 data;
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    struct adata *ptr;                        /* Attribute data elsewhere */
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  } u;
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} eattr;
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#define EAP_GENERIC 0                        /* Generic attributes */
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#define EAP_BGP 1                        /* BGP attributes */
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#define EAP_RIP 2                        /* RIP */
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#define EAP_OSPF 3                        /* OSPF */
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#define EAP_MAX 4
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#define EA_CODE(proto,id) (((proto) << 8) | (id))
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#define EA_PROTO(ea) ((ea) >> 8)
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#define EA_ID(ea) ((ea) & 0xff)
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#define EA_GEN_IGP_METRIC EA_CODE(EAP_GENERIC, 0)
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#define EA_CODE_MASK 0xffff
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#define EA_ALLOW_UNDEF 0x10000                /* ea_find: allow EAF_TYPE_UNDEF */
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#define EAF_TYPE_MASK 0x0f                /* Mask with this to get type */
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#define EAF_TYPE_INT 0x01                /* 32-bit signed integer number */
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#define EAF_TYPE_OPAQUE 0x02                /* Opaque byte string (not filterable) */
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#define EAF_TYPE_IP_ADDRESS 0x04        /* IP address */
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#define EAF_TYPE_ROUTER_ID 0x05                /* Router ID (IPv4 address) */
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#define EAF_TYPE_AS_PATH 0x06                /* BGP AS path (encoding per RFC 1771:4.3) */
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#define EAF_TYPE_INT_SET 0x0a                /* Set of u32's (e.g., a community list) */
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#define EAF_TYPE_UNDEF 0x0f                /* `force undefined' entry */
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#define EAF_EMBEDDED 0x01                /* Data stored in eattr.u.data (part of type spec) */
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#define EAF_VAR_LENGTH 0x02                /* Attribute length is variable (part of type spec) */
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#define EAF_ORIGINATED 0x40                /* The attribute has originated locally */
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#define EAF_TEMP 0x80                        /* A temporary attribute (the one stored in the tmp attr list) */
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struct adata {
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  unsigned int length;                        /* Length of data */
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  byte data[0];
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};
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typedef struct ea_list {
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  struct ea_list *next;                        /* In case we have an override list */
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  byte flags;                                /* Flags: EALF_... */
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  byte rfu;
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  word count;                                /* Number of attributes */
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  eattr attrs[0];                        /* Attribute definitions themselves */
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} ea_list;
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#define EALF_SORTED 1                        /* Attributes are sorted by code */
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#define EALF_BISECT 2                        /* Use interval bisection for searching */
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#define EALF_CACHED 4                        /* Attributes belonging to cached rta */
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eattr *ea_find(ea_list *, unsigned ea);
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int ea_get_int(ea_list *, unsigned ea, int def);
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void ea_dump(ea_list *);
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void ea_sort(ea_list *);                /* Sort entries in all sub-lists */
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unsigned ea_scan(ea_list *);                /* How many bytes do we need for merged ea_list */
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void ea_merge(ea_list *from, ea_list *to); /* Merge sub-lists to allocated buffer */
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int ea_same(ea_list *x, ea_list *y);        /* Test whether two ea_lists are identical */
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unsigned int ea_hash(ea_list *e);        /* Calculate 16-bit hash value */
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void ea_format(eattr *e, byte *buf);
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#define EA_FORMAT_BUF_SIZE 256
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ea_list *ea_append(ea_list *to, ea_list *what);
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int mpnh__same(struct mpnh *x, struct mpnh *y); /* Compare multipath nexthops */
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static inline int mpnh_same(struct mpnh *x, struct mpnh *y)
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{ return (x == y) || mpnh__same(x, y); }
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void rta_init(void);
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rta *rta_lookup(rta *);                        /* Get rta equivalent to this one, uc++ */
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static inline rta *rta_clone(rta *r) { r->uc++; return r; }
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void rta__free(rta *r);
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static inline void rta_free(rta *r) { if (r && !--r->uc) rta__free(r); }
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void rta_dump(rta *);
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void rta_dump_all(void);
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void rta_show(struct cli *, rta *, ea_list *);
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void rta_set_recursive_next_hop(rtable *dep, rta *a, rtable *tab, ip_addr *gw, ip_addr *ll);
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/*
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 * rta_set_recursive_next_hop() acquires hostentry from hostcache and
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 * fills rta->hostentry field.  New hostentry has zero use
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 * count. Cached rta locks its hostentry (increases its use count),
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 * uncached rta does not lock it. Hostentry with zero use count is
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 * removed asynchronously during host cache update, therefore it is
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 * safe to hold such hostentry temorarily. Hostentry holds a lock for
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 * a 'source' rta, mainly to share multipath nexthops. There is no
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 * need to hold a lock for hostentry->dep table, because that table
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 * contains routes responsible for that hostentry, and therefore is
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 * non-empty if given hostentry has non-zero use count. The protocol
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 * responsible for routes with recursive next hops should also hold a
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 * lock for a table governing that routes (argument tab to
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 * rta_set_recursive_next_hop()).
428
 */
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static inline void rt_lock_hostentry(struct hostentry *he) { if (he) he->uc++; }
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static inline void rt_unlock_hostentry(struct hostentry *he) { if (he) he->uc--; }
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extern struct protocol *attr_class_to_protocol[EAP_MAX];
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/*
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 *        Default protocol preferences
438
 */
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#define DEF_PREF_DIRECT                    240        /* Directly connected */
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#define DEF_PREF_STATIC                200        /* Static route */
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#define DEF_PREF_OSPF                150        /* OSPF intra-area, inter-area and type 1 external routes */
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#define DEF_PREF_RIP                120        /* RIP */
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#define DEF_PREF_BGP                100        /* BGP */
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#define DEF_PREF_PIPE                70        /* Routes piped from other tables */
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#define DEF_PREF_INHERITED        10        /* Routes inherited from other routing daemons */
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#endif