Internet on FIRE

/*

 *        BIRD Internet Routing Daemon -- Routing Table

 *

 *        (c) 1998--2000 Martin Mares <mj@ucw.cz>

 *

 *        Can be freely distributed and used under the terms of the GNU GPL.

 */

#ifndef _BIRD_ROUTE_H_

#define _BIRD_ROUTE_H_

#include "lib/lists.h"

#include "lib/resource.h"

#include "sysdep/unix/timer.h"

#include "lib/net.h"

struct ea_list;

struct protocol;

struct proto;

struct rte_src;

struct symbol;

struct filter;

struct cli;

/*

 *        Generic data structure for storing network prefixes. Also used

 *        for the master routing table. Currently implemented as a hash

 *        table.

 *

 *        Available operations:

 *                - insertion of new entry

 *                - deletion of entry

 *                - searching for entry by network prefix

 *                - asynchronous retrieval of fib contents

 */

struct fib_node {

  struct fib_node *next;                /* Next in hash chain */

  struct fib_iterator *readers;                /* List of readers of this node */

  byte flags;                                /* User-defined, will be removed */

  net_addr addr[0];

};

struct fib_iterator {                        /* See lib/slists.h for an explanation */

  struct fib_iterator *prev, *next;        /* Must be synced with struct fib_node! */

  byte efef;                                /* 0xff to distinguish between iterator and node */

  byte pad[3];

  struct fib_node *node;                /* Or NULL if freshly merged */

  uint hash;

};

typedef void (*fib_init_fn)(void *);

struct fib {

  pool *fib_pool;                        /* Pool holding all our data */

  slab *fib_slab;                        /* Slab holding all fib nodes */

  struct fib_node **hash_table;                /* Node hash table */

  uint hash_size;                        /* Number of hash table entries (a power of two) */

  uint hash_order;                        /* Binary logarithm of hash_size */

  uint hash_shift;                        /* 32 - hash_order */

  uint addr_type;                        /* Type of address data stored in fib (NET_*) */

  uint node_size;                        /* FIB node size, 0 for nonuniform */

  uint node_offset;                        /* Offset of fib_node struct inside of user data */

  uint entries;                                /* Number of entries */

  uint entries_min, entries_max;        /* Entry count limits (else start rehashing) */

  fib_init_fn init;                        /* Constructor */

};

static inline void * fib_node_to_user(struct fib *f, struct fib_node *e)

{ return e ? (void *) ((char *) e - f->node_offset) : NULL; }

static inline struct fib_node * fib_user_to_node(struct fib *f, void *e)

{ return e ? (void *) ((char *) e + f->node_offset) : NULL; }

void fib_init(struct fib *f, pool *p, uint addr_type, uint node_size, uint node_offset, uint hash_order, fib_init_fn init);

void *fib_find(struct fib *, const net_addr *);        /* Find or return NULL if doesn't exist */

void *fib_get_chain(struct fib *f, const net_addr *a); /* Find first node in linked list from hash table */

void *fib_get(struct fib *, const net_addr *);         /* Find or create new if nonexistent */

void *fib_route(struct fib *, const net_addr *); /* Longest-match routing lookup */

void fib_delete(struct fib *, void *);        /* Remove fib entry */

void fib_free(struct fib *);                /* Destroy the fib */

void fib_check(struct fib *);                /* Consistency check for debugging */

void fit_init(struct fib_iterator *, struct fib *); /* Internal functions, don't call */

struct fib_node *fit_get(struct fib *, struct fib_iterator *);

void fit_put(struct fib_iterator *, struct fib_node *);

void fit_put_next(struct fib *f, struct fib_iterator *i, struct fib_node *n, uint hpos);

#define FIB_WALK(fib, type, z) do {                                \

        struct fib_node *fn_, **ff_ = (fib)->hash_table;        \

        uint count_ = (fib)->hash_size;                                \

        type *z;                                                \

        while (count_--)                                        \

          for (fn_ = *ff_++; z = fib_node_to_user(fib, fn_); fn_=fn_->next)

#define FIB_WALK_END } while (0)

#define FIB_ITERATE_INIT(it, fib) fit_init(it, fib)

#define FIB_ITERATE_START(fib, it, type, z) do {                \

        struct fib_node *fn_ = fit_get(fib, it);                \

        uint count_ = (fib)->hash_size;                                \

        uint hpos_ = (it)->hash;                                \

        type *z;                                                \

        for(;;) {                                                \

          if (!fn_)                                                \

            {                                                        \

               if (++hpos_ >= count_)                                \

                 break;                                                \

               fn_ = (fib)->hash_table[hpos_];                        \

               continue;                                        \

            }                                                        \

          z = fib_node_to_user(fib, fn_);

#define FIB_ITERATE_END fn_ = fn_->next; } } while(0)

#define FIB_ITERATE_PUT(it) fit_put(it, fn_)

#define FIB_ITERATE_PUT_NEXT(it, fib) fit_put_next(fib, it, fn_, hpos_)

#define FIB_ITERATE_UNLINK(it, fib) fit_get(fib, it)

/*

 *        Master Routing Tables. Generally speaking, each of them contains a FIB

 *        with each entry pointing to a list of route entries representing routes

 *        to given network (with the selected one at the head).

 *

 *        Each of the RTE's contains variable data (the preference and protocol-dependent

 *        metrics) and a pointer to a route attribute block common for many routes).

 *

 *        It's guaranteed that there is at most one RTE for every (prefix,proto) pair.

 */

struct rtable_config {

  node n;

  char *name;

  struct rtable *table;

  struct proto_config *krt_attached;        /* Kernel syncer attached to this table */

  uint addr_type;                        /* Type of address data stored in table (NET_*) */

  int gc_max_ops;                        /* Maximum number of operations before GC is run */

  int gc_min_time;                        /* Minimum time between two consecutive GC runs */

  byte sorted;                                /* Routes of network are sorted according to rte_better() */

};

typedef struct rtable {

  node n;                                /* Node in list of all tables */

  struct fib fib;

  char *name;                                /* Name of this table */

  list channels;                        /* List of attached channels (struct channel) */

  uint addr_type;                        /* Type of address data stored in table (NET_*) */

  int pipe_busy;                        /* Pipe loop detection */

  int use_count;                        /* Number of protocols using this table */

  struct hostcache *hostcache;

  struct rtable_config *config;                /* Configuration of this table */

  struct config *deleted;                /* Table doesn't exist in current configuration,

                                         * delete as soon as use_count becomes 0 and remove

                                         * obstacle from this routing table.

                                         */

  struct event *rt_event;                /* Routing table event */

  int gc_counter;                        /* Number of operations since last GC */

  bird_clock_t gc_time;                        /* Time of last GC */

  byte prune_state;                        /* Table prune state, 1 -> scheduled, 2-> running */

  byte hcu_scheduled;                        /* Hostcache update is scheduled */

  byte nhu_state;                        /* Next Hop Update state */

  struct fib_iterator prune_fit;        /* Rtable prune FIB iterator */

  struct fib_iterator nhu_fit;                /* Next Hop Update FIB iterator */

} rtable;

typedef struct network {

  struct rte *routes;                        /* Available routes for this network */

  struct fib_node n;                        /* FIB flags reserved for kernel syncer */

} net;

struct hostcache {

  slab *slab;                                /* Slab holding all hostentries */

  struct hostentry **hash_table;        /* Hash table for hostentries */

  unsigned hash_order, hash_shift;

  unsigned hash_max, hash_min;

  unsigned hash_items;

  linpool *lp;                                /* Linpool for trie */

  struct f_trie *trie;                        /* Trie of prefixes that might affect hostentries */

  list hostentries;                        /* List of all hostentries */

  byte update_hostcache;

};

struct hostentry {

  node ln;

  ip_addr addr;                                /* IP address of host, part of key */

  ip_addr link;                                /* (link-local) IP address of host, used as gw

                                           if host is directly attached */

  struct rtable *tab;                        /* Dependent table, part of key */

  struct hostentry *next;                /* Next in hash chain */

  unsigned hash_key;                        /* Hash key */

  unsigned uc;                                /* Use count */

  struct rta *src;                        /* Source rta entry */

  struct nexthop *nh;                        /* Chosen next hop */

  byte dest;                                /* Chosen route destination type (RTD_...) */

  u32 igp_metric;                        /* Chosen route IGP metric */

};

typedef struct rte {

  struct rte *next;

  net *net;                                /* Network this RTE belongs to */

  struct channel *sender;                /* Channel used to send the route to the routing table */

  struct rta *attrs;                        /* Attributes of this route */

  byte flags;                                /* Flags (REF_...) */

  byte pflags;                                /* Protocol-specific flags */

  word pref;                                /* Route preference */

  bird_clock_t lastmod;                        /* Last modified */

  union {                                /* Protocol-dependent data (metrics etc.) */

#ifdef CONFIG_RIP

    struct {

      struct iface *from;                /* Incoming iface */

      u8 metric;                        /* RIP metric */

      u16 tag;                                /* External route tag */

    } rip;

#endif

#ifdef CONFIG_OSPF

    struct {

      u32 metric1, metric2;                /* OSPF Type 1 and Type 2 metrics */

      u32 tag;                                /* External route tag */

      u32 router_id;                        /* Router that originated this route */

    } ospf;

#endif

#ifdef CONFIG_BGP

    struct {

      u8 suppressed;                        /* Used for deterministic MED comparison */

    } bgp;

#endif

#ifdef CONFIG_BABEL

    struct {

      u16 metric;                        /* Babel metric */

      u64 router_id;                        /* Babel router id */

    } babel;

#endif

    struct {                                /* Routes generated by krt sync (both temporary and inherited ones) */

      s8 src;                                /* Alleged route source (see krt.h) */

      u8 proto;                                /* Kernel source protocol ID */

      u8 seen;                                /* Seen during last scan */

      u8 best;                                /* Best route in network, propagated to core */

      u32 metric;                        /* Kernel metric */

    } krt;

  } u;

} rte;

#define REF_COW                1                /* Copy this rte on write */

#define REF_FILTERED        2                /* Route is rejected by import filter */

#define REF_STALE        4                /* Route is stale in a refresh cycle */

#define REF_DISCARD        8                /* Route is scheduled for discard */

/* Route is valid for propagation (may depend on other flags in the future), accepts NULL */

static inline int rte_is_valid(rte *r) { return r && !(r->flags & REF_FILTERED); }

/* Route just has REF_FILTERED flag */

static inline int rte_is_filtered(rte *r) { return !!(r->flags & REF_FILTERED); }

/* Types of route announcement, also used as flags */

#define RA_OPTIMAL        1                /* Announcement of optimal route change */

#define RA_ACCEPTED        2                /* Announcement of first accepted route */

#define RA_ANY                3                /* Announcement of any route change */

#define RA_MERGED        4                /* Announcement of optimal route merged with next ones */

/* Return value of import_control() callback */

#define RIC_ACCEPT        1                /* Accepted by protocol */

#define RIC_PROCESS        0                /* Process it through import filter */

#define RIC_REJECT        -1                /* Rejected by protocol */

#define RIC_DROP        -2                /* Silently dropped by protocol */

struct config;

void rt_init(void);

void rt_preconfig(struct config *);

void rt_commit(struct config *new, struct config *old);

void rt_lock_table(rtable *);

void rt_unlock_table(rtable *);

void rt_setup(pool *, rtable *, char *, struct rtable_config *);

static inline net *net_find(rtable *tab, const net_addr *addr) { return (net *) fib_find(&tab->fib, addr); }

static inline net *net_get(rtable *tab, const net_addr *addr) { return (net *) fib_get(&tab->fib, addr); }

void *net_route(rtable *tab, const net_addr *n);

int net_roa_check(rtable *tab, const net_addr *n, u32 asn);

rte *rte_find(net *net, struct rte_src *src);

rte *rte_get_temp(struct rta *);

void rte_update2(struct channel *c, const net_addr *n, rte *new, struct rte_src *src);

/* rte_update() moved to protocol.h to avoid dependency conflicts */

int rt_examine(rtable *t, net_addr *a, struct proto *p, struct filter *filter);

rte *rt_export_merged(struct channel *c, net *net, rte **rt_free, struct ea_list **tmpa, linpool *pool, int silent);

void rt_refresh_begin(rtable *t, struct channel *c);

void rt_refresh_end(rtable *t, struct channel *c);

void rt_schedule_prune(rtable *t);

void rte_dump(rte *);

void rte_free(rte *);

rte *rte_do_cow(rte *);

static inline rte * rte_cow(rte *r) { return (r->flags & REF_COW) ? rte_do_cow(r) : r; }

rte *rte_cow_rta(rte *r, linpool *lp);

void rt_dump(rtable *);

void rt_dump_all(void);

int rt_feed_channel(struct channel *c);

void rt_feed_channel_abort(struct channel *c);

struct rtable_config *rt_new_table(struct symbol *s, uint addr_type);

struct rt_show_data {

  net_addr *addr;

  rtable *table;

  struct filter *filter;

  int verbose;

  struct fib_iterator fit;

  struct proto *show_protocol;

  struct proto *export_protocol;

  struct channel *export_channel;

  int export_mode, primary_only, filtered;

  struct config *running_on_config;

  int net_counter, rt_counter, show_counter;

  int stats, show_for;

};

void rt_show(struct rt_show_data *);

/* Value of export_mode in struct rt_show_data */

#define RSEM_NONE        0                /* Export mode not used */

#define RSEM_PREEXPORT        1                /* Routes ready for export, before filtering */

#define RSEM_EXPORT        2                /* Routes accepted by export filter */

#define RSEM_NOEXPORT        3                /* Routes rejected by export filter */

/*

 *        Route Attributes

 *

 *        Beware: All standard BGP attributes must be represented here instead

 *        of making them local to the route. This is needed to ensure proper

 *        construction of BGP route attribute lists.

 */

/* Nexthop structure */

struct nexthop {

  ip_addr gw;                                /* Next hop */

  struct iface *iface;                        /* Outgoing interface */

  struct nexthop *next;

  byte weight;

  byte labels_append;                        /* Number of labels before hostentry was applied */

  byte labels;                                /* Number of labels prepended */

  u32 label[0];

};

struct rte_src {

  struct rte_src *next;                        /* Hash chain */

  struct proto *proto;                        /* Protocol the source is based on */

  u32 private_id;                        /* Private ID, assigned by the protocol */

  u32 global_id;                        /* Globally unique ID of the source */

  unsigned uc;                                /* Use count */

};

typedef struct rta {

  struct rta *next, **pprev;                /* Hash chain */

  u32 uc;                                /* Use count */

  u32 hash_key;                                /* Hash over important fields */

  struct ea_list *eattrs;                /* Extended Attribute chain */

  struct rte_src *src;                        /* Route source that created the route */

  struct hostentry *hostentry;                /* Hostentry for recursive next-hops */

  ip_addr from;                                /* Advertising router */

  u32 igp_metric;                        /* IGP metric to next hop (for iBGP routes) */

  u8 source;                                /* Route source (RTS_...) */

  u8 scope;                                /* Route scope (SCOPE_... -- see ip.h) */

  u8 dest;                                /* Route destination type (RTD_...) */

  u8 aflags;

  struct nexthop nh;                        /* Next hop */

} rta;

#define RTS_DUMMY 0                        /* Dummy route to be removed soon */

#define RTS_STATIC 1                        /* Normal static route */

#define RTS_INHERIT 2                        /* Route inherited from kernel */

#define RTS_DEVICE 3                        /* Device route */

#define RTS_STATIC_DEVICE 4                /* Static device route */

#define RTS_REDIRECT 5                        /* Learned via redirect */

#define RTS_RIP 6                        /* RIP route */

#define RTS_OSPF 7                        /* OSPF route */

#define RTS_OSPF_IA 8                        /* OSPF inter-area route */

#define RTS_OSPF_EXT1 9                        /* OSPF external route type 1 */

#define RTS_OSPF_EXT2 10                /* OSPF external route type 2 */

#define RTS_BGP 11                        /* BGP route */

#define RTS_PIPE 12                        /* Inter-table wormhole */

#define RTS_BABEL 13                        /* Babel route */

#define RTS_RPKI 14                        /* Route Origin Authorization */

#define RTC_UNICAST 0

#define RTC_BROADCAST 1

#define RTC_MULTICAST 2

#define RTC_ANYCAST 3                        /* IPv6 Anycast */

#define RTD_NONE 0                        /* Undefined next hop */

#define RTD_UNICAST 1                        /* Next hop is neighbor router */

#define RTD_BLACKHOLE 2                        /* Silently drop packets */

#define RTD_UNREACHABLE 3                /* Reject as unreachable */

#define RTD_PROHIBIT 4                        /* Administratively prohibited */

                                        /* Flags for net->n.flags, used by kernel syncer */

#define KRF_INSTALLED 0x80                /* This route should be installed in the kernel */

#define KRF_SYNC_ERROR 0x40                /* Error during kernel table synchronization */

#define RTAF_CACHED 1                        /* This is a cached rta */

#define IGP_METRIC_UNKNOWN 0x80000000        /* Default igp_metric used when no other

                                           protocol-specific metric is availabe */

/* Route has regular, reachable nexthop (i.e. not RTD_UNREACHABLE and like) */

static inline int rte_is_reachable(rte *r)

{ return r->attrs->dest == RTD_UNICAST; }

/*

 *        Extended Route Attributes

 */

typedef struct eattr {

  word id;                                /* EA_CODE(EAP_..., protocol-dependent ID) */

  byte flags;                                /* Protocol-dependent flags */

  byte type;                                /* Attribute type and several flags (EAF_...) */

  union {

    u32 data;

    struct adata *ptr;                        /* Attribute data elsewhere */

  } u;

} eattr;

#define EAP_GENERIC 0                        /* Generic attributes */

#define EAP_BGP 1                        /* BGP attributes */

#define EAP_RIP 2                        /* RIP */

#define EAP_OSPF 3                        /* OSPF */

#define EAP_KRT 4                        /* Kernel route attributes */

#define EAP_BABEL 5                        /* Babel attributes */

#define EAP_MAX 6

#define EA_CODE(proto,id) (((proto) << 8) | (id))

#define EA_PROTO(ea) ((ea) >> 8)

#define EA_ID(ea) ((ea) & 0xff)

#define EA_GEN_IGP_METRIC EA_CODE(EAP_GENERIC, 0)

#define EA_CODE_MASK 0xffff

#define EA_ALLOW_UNDEF 0x10000                /* ea_find: allow EAF_TYPE_UNDEF */

#define EA_BIT(n) ((n) << 24)                /* Used in bitfield accessors */

#define EAF_TYPE_MASK 0x1f                /* Mask with this to get type */

#define EAF_TYPE_INT 0x01                /* 32-bit unsigned integer number */

#define EAF_TYPE_OPAQUE 0x02                /* Opaque byte string (not filterable) */

#define EAF_TYPE_IP_ADDRESS 0x04        /* IP address */

#define EAF_TYPE_ROUTER_ID 0x05                /* Router ID (IPv4 address) */

#define EAF_TYPE_AS_PATH 0x06                /* BGP AS path (encoding per RFC 1771:4.3) */

#define EAF_TYPE_BITFIELD 0x09                /* 32-bit embedded bitfield */

#define EAF_TYPE_INT_SET 0x0a                /* Set of u32's (e.g., a community list) */

#define EAF_TYPE_EC_SET 0x0e                /* Set of pairs of u32's - ext. community list */

#define EAF_TYPE_LC_SET 0x12                /* Set of triplets of u32's - large community list */

#define EAF_TYPE_UNDEF 0x1f                /* `force undefined' entry */

#define EAF_EMBEDDED 0x01                /* Data stored in eattr.u.data (part of type spec) */

#define EAF_VAR_LENGTH 0x02                /* Attribute length is variable (part of type spec) */

#define EAF_ORIGINATED 0x20                /* The attribute has originated locally */

#define EAF_FRESH 0x40                        /* An uncached attribute (e.g. modified in export filter) */

#define EAF_TEMP 0x80                        /* A temporary attribute (the one stored in the tmp attr list) */

typedef struct adata {

  uint length;                                /* Length of data */

  byte data[0];

} adata;

static inline struct adata *

lp_alloc_adata(struct linpool *pool, uint len)

{

  struct adata *ad = lp_alloc(pool, sizeof(struct adata) + len);

  ad->length = len;

  return ad;

}

static inline int adata_same(struct adata *a, struct adata *b)

{ return (a->length == b->length && !memcmp(a->data, b->data, a->length)); }

typedef struct ea_list {

  struct ea_list *next;                        /* In case we have an override list */

  byte flags;                                /* Flags: EALF_... */

  byte rfu;

  word count;                                /* Number of attributes */

  eattr attrs[0];                        /* Attribute definitions themselves */

} ea_list;

#define EALF_SORTED 1                        /* Attributes are sorted by code */

#define EALF_BISECT 2                        /* Use interval bisection for searching */

#define EALF_CACHED 4                        /* Attributes belonging to cached rta */

struct rte_src *rt_find_source(struct proto *p, u32 id);

struct rte_src *rt_get_source(struct proto *p, u32 id);

static inline void rt_lock_source(struct rte_src *src) { src->uc++; }

static inline void rt_unlock_source(struct rte_src *src) { src->uc--; }

void rt_prune_sources(void);

struct ea_walk_state {

  ea_list *eattrs;                        /* Ccurrent ea_list, initially set by caller */

  eattr *ea;                                /* Current eattr, initially NULL */

  u32 visited[4];                        /* Bitfield, limiting max to 128 */

};

eattr *ea_find(ea_list *, unsigned ea);

eattr *ea_walk(struct ea_walk_state *s, uint id, uint max);

int ea_get_int(ea_list *, unsigned ea, int def);

void ea_dump(ea_list *);

void ea_sort(ea_list *);                /* Sort entries in all sub-lists */

unsigned ea_scan(ea_list *);                /* How many bytes do we need for merged ea_list */

void ea_merge(ea_list *from, ea_list *to); /* Merge sub-lists to allocated buffer */

int ea_same(ea_list *x, ea_list *y);        /* Test whether two ea_lists are identical */

uint ea_hash(ea_list *e);        /* Calculate 16-bit hash value */

ea_list *ea_append(ea_list *to, ea_list *what);

void ea_format_bitfield(struct eattr *a, byte *buf, int bufsize, const char **names, int min, int max);

#define NEXTHOP_MAX_SIZE (sizeof(struct nexthop) + sizeof(u32)*MPLS_MAX_LABEL_STACK)

static inline size_t nexthop_size(const struct nexthop *nh)

{ return sizeof(struct nexthop) + sizeof(u32)*nh->labels; }

int nexthop__same(struct nexthop *x, struct nexthop *y); /* Compare multipath nexthops */

static inline int nexthop_same(struct nexthop *x, struct nexthop *y)

{ return (x == y) || nexthop__same(x, y); }

struct nexthop *nexthop_merge(struct nexthop *x, struct nexthop *y, int rx, int ry, int max, linpool *lp);

static inline void nexthop_link(struct rta *a, struct nexthop *from)

{ memcpy(&a->nh, from, nexthop_size(from)); }

void nexthop_insert(struct nexthop **n, struct nexthop *y);

int nexthop_is_sorted(struct nexthop *x);

void rta_init(void);

static inline size_t rta_size(const rta *a) { return sizeof(rta) + sizeof(u32)*a->nh.labels; }

#define RTA_MAX_SIZE (sizeof(rta) + sizeof(u32)*MPLS_MAX_LABEL_STACK)

rta *rta_lookup(rta *);                        /* Get rta equivalent to this one, uc++ */

static inline int rta_is_cached(rta *r) { return r->aflags & RTAF_CACHED; }

static inline rta *rta_clone(rta *r) { r->uc++; return r; }

void rta__free(rta *r);

static inline void rta_free(rta *r) { if (r && !--r->uc) rta__free(r); }

rta *rta_do_cow(rta *o, linpool *lp);

static inline rta * rta_cow(rta *r, linpool *lp) { return rta_is_cached(r) ? rta_do_cow(r, lp) : r; }

void rta_dump(rta *);

void rta_dump_all(void);

void rta_show(struct cli *, rta *, ea_list *);

void rta_set_recursive_next_hop(rtable *dep, rta *a, rtable *tab, ip_addr gw, ip_addr ll);

/*

 * rta_set_recursive_next_hop() acquires hostentry from hostcache and fills

 * rta->hostentry field.  New hostentry has zero use count. Cached rta locks its

 * hostentry (increases its use count), uncached rta does not lock it. Hostentry

 * with zero use count is removed asynchronously during host cache update,

 * therefore it is safe to hold such hostentry temorarily. Hostentry holds a

 * lock for a 'source' rta, mainly to share multipath nexthops.

 *

 * There is no need to hold a lock for hostentry->dep table, because that table

 * contains routes responsible for that hostentry, and therefore is non-empty if

 * given hostentry has non-zero use count. If the hostentry has zero use count,

 * the entry is removed before dep is referenced.

 *

 * The protocol responsible for routes with recursive next hops should hold a

 * lock for a 'source' table governing that routes (argument tab to

 * rta_set_recursive_next_hop()), because its routes reference hostentries

 * (through rta) related to the governing table. When all such routes are

 * removed, rtas are immediately removed achieving zero uc. Then the 'source'

 * table lock could be immediately released, although hostentries may still

 * exist - they will be freed together with the 'source' table.

 */

static inline void rt_lock_hostentry(struct hostentry *he) { if (he) he->uc++; }

static inline void rt_unlock_hostentry(struct hostentry *he) { if (he) he->uc--; }

extern struct protocol *attr_class_to_protocol[EAP_MAX];

/*

 *        Default protocol preferences

 */

#define DEF_PREF_DIRECT                    240        /* Directly connected */

#define DEF_PREF_STATIC                200        /* Static route */

#define DEF_PREF_OSPF                150        /* OSPF intra-area, inter-area and type 1 external routes */

#define DEF_PREF_BABEL                130        /* Babel */

#define DEF_PREF_RIP                120        /* RIP */

#define DEF_PREF_BGP                100        /* BGP */

#define DEF_PREF_RPKI                100        /* RPKI */

#define DEF_PREF_INHERITED        10        /* Routes inherited from other routing daemons */

/*

 *        Route Origin Authorization

 */

#define ROA_UNKNOWN        0

#define ROA_VALID        1

#define ROA_INVALID        2

#endif