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 "lib/timer.h"

struct protocol;

struct proto;

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 pxlen;

  byte flags;                                /* User-defined */

  byte x0, x1;                                /* User-defined */

  u32 uid;                                /* Unique ID based on hash */

  ip_addr prefix;                        /* In host order */

};

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 */

  unsigned int hash;

};

typedef void (*fib_init_func)(struct fib_node *);

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 */

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

  unsigned int hash_order;                /* Binary logarithm of hash_size */

  unsigned int hash_shift;                /* 16 - hash_log */

  unsigned int entries;                        /* Number of entries */

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

  fib_init_func init;                        /* Constructor */

};

void fib_init(struct fib *, pool *, unsigned node_size, unsigned hash_order, fib_init_func init);

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

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

void *fib_route(struct fib *, ip_addr, int);        /* 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 *);

#define FIB_WALK(fib, z) do {                                        \

        struct fib_node *z, **ff = (fib)->hash_table;                \

        unsigned int count = (fib)->hash_size;                        \

        while (count--)                                                \

          for(z = *ff++; z; z=z->next)

#define FIB_WALK_END } while (0)

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

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

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

        unsigned int count = (fib)->hash_size;                        \

        unsigned int hpos = (it)->hash;                                \

        for(;;) {                                                \

          if (!z)                                                \

            {                                                        \

               if (++hpos >= count)                                \

                 break;                                                \

               z = (fib)->hash_table[hpos];                        \

               continue;                                        \

            }

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

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

/*

 *        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 */

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

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

};

typedef struct rtable {

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

  struct fib fib;

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

  list hooks;                                /* List of announcement hooks */

  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 gc_scheduled;                        /* GC is scheduled */

  byte hcu_scheduled;                        /* Hostcache update is scheduled */

  byte nhu_state;                        /* Next Hop Update state */

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

} rtable;

typedef struct network {

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

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

} 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 iface *iface;                        /* Chosen outgoing interface */

  ip_addr gw;                                /* 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 proto *sender;                        /* Protocol instance that sent 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 {

      node garbage;                        /* List for garbage collection */

      byte metric;                        /* RIP metric */

      u16 tag;                                /* External route tag */

      struct rip_entry *entry;

    } 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

    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 type;                                /* Kernel route type */

      u8 seen;                                /* Seen during last scan */

      u32 metric;                        /* Kernel metric */

    } krt;

  } u;

} rte;

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

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

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

#define RA_ANY 2                        /* Announcement of any route change */

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, ip_addr addr, unsigned len) { return (net *) fib_find(&tab->fib, &addr, len); }

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

rte *rte_find(net *net, struct proto *p);

rte *rte_get_temp(struct rta *);

void rte_update(rtable *tab, net *net, struct proto *p, struct proto *src, rte *new);

void rte_discard(rtable *tab, rte *old);

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; }

void rt_dump(rtable *);

void rt_dump_all(void);

int rt_feed_baby(struct proto *p);

void rt_feed_baby_abort(struct proto *p);

void rt_prune_all(void);

struct rtable_config *rt_new_table(struct symbol *s);

struct rt_show_data {

  ip_addr prefix;

  unsigned pxlen;

  rtable *table;

  struct filter *filter;

  int verbose;

  struct fib_iterator fit;

  struct proto *show_protocol;

  struct proto *export_protocol;

  int export_mode, primary_only;

  struct config *running_on_config;

  int net_counter, rt_counter, show_counter;

  int stats, show_for;

};

void rt_show(struct rt_show_data *);

/*

 *        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.

 */

typedef struct rta {

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

  struct proto *proto;                        /* Protocol instance that originally created the route */

  unsigned uc;                                /* Use count */

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

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

  byte cast;                                /* Casting type (RTC_...) */

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

  byte flags;                                /* Route flags (RTF_...), now unused */

  byte aflags;                                /* Attribute cache flags (RTAF_...) */

  u16 hash_key;                                /* Hash over important fields */

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

  ip_addr gw;                                /* Next hop */

  ip_addr from;                                /* Advertising router */

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

  struct iface *iface;                        /* Outgoing interface */

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

} 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 RTC_UNICAST 0

#define RTC_BROADCAST 1

#define RTC_MULTICAST 2

#define RTC_ANYCAST 3                        /* IPv6 Anycast */

#define RTD_ROUTER 0                        /* Next hop is neighbor router */

#define RTD_DEVICE 1                        /* Points to device */

#define RTD_BLACKHOLE 2                        /* Silently drop packets */

#define RTD_UNREACHABLE 3                /* Reject as unreachable */

#define RTD_PROHIBIT 4                        /* Administratively prohibited */

#define RTD_NONE 5                        /* Invalid RTD */

#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 */

/*

 *        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_MAX 4

#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 EAF_TYPE_MASK 0x0f                /* Mask with this to get type */

#define EAF_TYPE_INT 0x01                /* 32-bit signed 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_INT_SET 0x0a                /* Set of u32's (e.g., a community list) */

#define EAF_TYPE_UNDEF 0x0f                /* `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 0x40                /* The attribute has originated locally */

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

struct adata {

  unsigned int length;                        /* Length of data */

  byte data[0];

};

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 */

eattr *ea_find(ea_list *, unsigned ea);

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 */

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

void ea_format(eattr *e, byte *buf);

#define EA_FORMAT_BUF_SIZE 256

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

void rta_init(void);

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

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); }

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. 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. The protocol responsible for routes

 * with recursive next hops should also hold a lock for a table governing

 * that routes (argument tab to rta_set_recursive_next_hop()).

 */

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_RIP                120        /* RIP */

#define DEF_PREF_BGP                100        /* BGP */

#define DEF_PREF_PIPE                70        /* Routes piped from other tables */

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

#endif