nest/route.h

   1 /*
   2  *      BIRD Internet Routing Daemon -- Routing Table
   3  *
   4  *      (c) 1998--2000 Martin Mares <mj@ucw.cz>
   5  *
   6  *      Can be freely distributed and used under the terms of the GNU GPL.
   7  */
   8
   9 #ifndef _BIRD_ROUTE_H_
  10 #define _BIRD_ROUTE_H_
  11
  12 #include "lib/lists.h"
  13 #include "lib/resource.h"
  14 #include "sysdep/unix/timer.h"
  15 #include "lib/net.h"
  16
  17 struct ea_list;
  18 struct protocol;
  19 struct proto;
  20 struct rte_src;
  21 struct symbol;
  22 struct filter;
  23 struct cli;
  24
  25 /*
  26  *      Generic data structure for storing network prefixes. Also used
  27  *      for the master routing table. Currently implemented as a hash
  28  *      table.
  29  *
  30  *      Available operations:
  31  *              - insertion of new entry
  32  *              - deletion of entry
  33  *              - searching for entry by network prefix
  34  *              - asynchronous retrieval of fib contents
  35  */
  36
  37 struct fib_node {
  38   struct fib_node *next;                /* Next in hash chain */
  39   struct fib_iterator *readers;         /* List of readers of this node */
  40   byte flags;                           /* User-defined, will be removed */
  41   net_addr addr[0];
  42 };
  43
  44 struct fib_iterator {                   /* See lib/slists.h for an explanation */
  45   struct fib_iterator *prev, *next;     /* Must be synced with struct fib_node! */
  46   byte efef;                            /* 0xff to distinguish between iterator and node */
  47   byte pad[3];
  48   struct fib_node *node;                /* Or NULL if freshly merged */
  49   uint hash;
  50 };
  51
  52 typedef void (*fib_init_fn)(void *);
  53
  54 struct fib {
  55   pool *fib_pool;                       /* Pool holding all our data */
  56   slab *fib_slab;                       /* Slab holding all fib nodes */
  57   struct fib_node **hash_table;         /* Node hash table */
  58   uint hash_size;                       /* Number of hash table entries (a power of two) */
  59   uint hash_order;                      /* Binary logarithm of hash_size */
  60   uint hash_shift;                      /* 32 - hash_order */
  61   uint addr_type;                       /* Type of address data stored in fib (NET_*) */
  62   uint node_size;                       /* FIB node size, 0 for nonuniform */
  63   uint node_offset;                     /* Offset of fib_node struct inside of user data */
  64   uint entries;                         /* Number of entries */
  65   uint entries_min, entries_max;        /* Entry count limits (else start rehashing) */
  66   fib_init_fn init;                     /* Constructor */
  67 };
  68
  69 static inline void * fib_node_to_user(struct fib *f, struct fib_node *e)
  70 { return e ? (void *) ((char *) e - f->node_offset) : NULL; }
  71
  72 static inline struct fib_node * fib_user_to_node(struct fib *f, void *e)
  73 { return e ? (void *) ((char *) e + f->node_offset) : NULL; }
  74
  75 void fib_init(struct fib *f, pool *p, uint addr_type, uint node_size, uint node_offset, uint hash_order, fib_init_fn init);
  76 void *fib_find(struct fib *, const net_addr *); /* Find or return NULL if doesn't exist */
  77 void *fib_get_chain(struct fib *f, const net_addr *a); /* Find first node in linked list from hash table */
  78 void *fib_get(struct fib *, const net_addr *);  /* Find or create new if nonexistent */
  79 void *fib_route(struct fib *, const net_addr *); /* Longest-match routing lookup */
  80 void fib_delete(struct fib *, void *);  /* Remove fib entry */
  81 void fib_free(struct fib *);            /* Destroy the fib */
  82 void fib_check(struct fib *);           /* Consistency check for debugging */
  83
  84 void fit_init(struct fib_iterator *, struct fib *); /* Internal functions, don't call */
  85 struct fib_node *fit_get(struct fib *, struct fib_iterator *);
  86 void fit_put(struct fib_iterator *, struct fib_node *);
  87 void fit_put_next(struct fib *f, struct fib_iterator *i, struct fib_node *n, uint hpos);
  88
  89
  90 #define FIB_WALK(fib, type, z) do {                             \
  91         struct fib_node *fn_, **ff_ = (fib)->hash_table;        \
  92         uint count_ = (fib)->hash_size;                         \
  93         type *z;                                                \
  94         while (count_--)                                        \
  95           for (fn_ = *ff_++; z = fib_node_to_user(fib, fn_); fn_=fn_->next)
  96
  97 #define FIB_WALK_END } while (0)
  98
  99 #define FIB_ITERATE_INIT(it, fib) fit_init(it, fib)
 100
 101 #define FIB_ITERATE_START(fib, it, type, z) do {                \
 102         struct fib_node *fn_ = fit_get(fib, it);                \
 103         uint count_ = (fib)->hash_size;                         \
 104         uint hpos_ = (it)->hash;                                \
 105         type *z;                                                \
 106         for(;;) {                                               \
 107           if (!fn_)                                             \
 108             {                                                   \
 109                if (++hpos_ >= count_)                           \
 110                  break;                                         \
 111                fn_ = (fib)->hash_table[hpos_];                  \
 112                continue;                                        \
 113             }                                                   \
 114           z = fib_node_to_user(fib, fn_);
 115
 116 #define FIB_ITERATE_END fn_ = fn_->next; } } while(0)
 117
 118 #define FIB_ITERATE_PUT(it) fit_put(it, fn_)
 119
 120 #define FIB_ITERATE_PUT_NEXT(it, fib) fit_put_next(fib, it, fn_, hpos_)
 121
 122 #define FIB_ITERATE_UNLINK(it, fib) fit_get(fib, it)
 123
 124
 125 /*
 126  *      Master Routing Tables. Generally speaking, each of them contains a FIB
 127  *      with each entry pointing to a list of route entries representing routes
 128  *      to given network (with the selected one at the head).
 129  *
 130  *      Each of the RTE's contains variable data (the preference and protocol-dependent
 131  *      metrics) and a pointer to a route attribute block common for many routes).
 132  *
 133  *      It's guaranteed that there is at most one RTE for every (prefix,proto) pair.
 134  */
 135
 136 struct rtable_config {
 137   node n;
 138   char *name;
 139   struct rtable *table;
 140   struct proto_config *krt_attached;    /* Kernel syncer attached to this table */
 141   uint addr_type;                       /* Type of address data stored in table (NET_*) */
 142   int gc_max_ops;                       /* Maximum number of operations before GC is run */
 143   int gc_min_time;                      /* Minimum time between two consecutive GC runs */
 144   byte sorted;                          /* Routes of network are sorted according to rte_better() */
 145 };
 146
 147 typedef struct rtable {
 148   node n;                               /* Node in list of all tables */
 149   struct fib fib;
 150   char *name;                           /* Name of this table */
 151   list channels;                        /* List of attached channels (struct channel) */
 152   uint addr_type;                       /* Type of address data stored in table (NET_*) */
 153   int pipe_busy;                        /* Pipe loop detection */
 154   int use_count;                        /* Number of protocols using this table */
 155   struct hostcache *hostcache;
 156   struct rtable_config *config;         /* Configuration of this table */
 157   struct config *deleted;               /* Table doesn't exist in current configuration,
 158                                          * delete as soon as use_count becomes 0 and remove
 159                                          * obstacle from this routing table.
 160                                          */
 161   struct event *rt_event;               /* Routing table event */
 162   int gc_counter;                       /* Number of operations since last GC */
 163   bird_clock_t gc_time;                 /* Time of last GC */
 164   byte prune_state;                     /* Table prune state, 1 -> scheduled, 2-> running */
 165   byte hcu_scheduled;                   /* Hostcache update is scheduled */
 166   byte nhu_state;                       /* Next Hop Update state */
 167   struct fib_iterator prune_fit;        /* Rtable prune FIB iterator */
 168   struct fib_iterator nhu_fit;          /* Next Hop Update FIB iterator */
 169 } rtable;
 170
 171 #define NHU_CLEAN       0
 172 #define NHU_SCHEDULED   1
 173 #define NHU_RUNNING     2
 174 #define NHU_DIRTY       3
 175
 176 typedef struct network {
 177   struct rte *routes;                   /* Available routes for this network */
 178   struct fib_node n;                    /* FIB flags reserved for kernel syncer */
 179 } net;
 180
 181 struct hostcache {
 182   slab *slab;                           /* Slab holding all hostentries */
 183   struct hostentry **hash_table;        /* Hash table for hostentries */
 184   unsigned hash_order, hash_shift;
 185   unsigned hash_max, hash_min;
 186   unsigned hash_items;
 187   linpool *lp;                          /* Linpool for trie */
 188   struct f_trie *trie;                  /* Trie of prefixes that might affect hostentries */
 189   list hostentries;                     /* List of all hostentries */
 190   byte update_hostcache;
 191 };
 192
 193 struct hostentry {
 194   node ln;
 195   ip_addr addr;                         /* IP address of host, part of key */
 196   ip_addr link;                         /* (link-local) IP address of host, used as gw
 197                                            if host is directly attached */
 198   struct rtable *tab;                   /* Dependent table, part of key */
 199   struct hostentry *next;               /* Next in hash chain */
 200   unsigned hash_key;                    /* Hash key */
 201   unsigned uc;                          /* Use count */
 202   struct rta *src;                      /* Source rta entry */
 203   byte dest;                            /* Chosen route destination type (RTD_...) */
 204   byte nexthop_linkable;                /* Nexthop list is completely non-device */
 205   u32 igp_metric;                       /* Chosen route IGP metric */
 206 };
 207
 208 typedef struct rte {
 209   struct rte *next;
 210   net *net;                             /* Network this RTE belongs to */
 211   struct channel *sender;               /* Channel used to send the route to the routing table */
 212   struct rta *attrs;                    /* Attributes of this route */
 213   byte flags;                           /* Flags (REF_...) */
 214   byte pflags;                          /* Protocol-specific flags */
 215   word pref;                            /* Route preference */
 216   bird_clock_t lastmod;                 /* Last modified */
 217   union {                               /* Protocol-dependent data (metrics etc.) */
 218 #ifdef CONFIG_RIP
 219     struct {
 220       struct iface *from;               /* Incoming iface */
 221       u8 metric;                        /* RIP metric */
 222       u16 tag;                          /* External route tag */
 223     } rip;
 224 #endif
 225 #ifdef CONFIG_OSPF
 226     struct {
 227       u32 metric1, metric2;             /* OSPF Type 1 and Type 2 metrics */
 228       u32 tag;                          /* External route tag */
 229       u32 router_id;                    /* Router that originated this route */
 230     } ospf;
 231 #endif
 232 #ifdef CONFIG_BGP
 233     struct {
 234       u8 suppressed;                    /* Used for deterministic MED comparison */
 235     } bgp;
 236 #endif
 237 #ifdef CONFIG_BABEL
 238     struct {
 239       u16 metric;                       /* Babel metric */
 240       u64 router_id;                    /* Babel router id */
 241     } babel;
 242 #endif
 243     struct {                            /* Routes generated by krt sync (both temporary and inherited ones) */
 244       s8 src;                           /* Alleged route source (see krt.h) */
 245       u8 proto;                         /* Kernel source protocol ID */
 246       u8 seen;                          /* Seen during last scan */
 247       u8 best;                          /* Best route in network, propagated to core */
 248       u32 metric;                       /* Kernel metric */
 249     } krt;
 250   } u;
 251 } rte;
 252
 253 #define REF_COW         1               /* Copy this rte on write */
 254 #define REF_FILTERED    2               /* Route is rejected by import filter */
 255 #define REF_STALE       4               /* Route is stale in a refresh cycle */
 256 #define REF_DISCARD     8               /* Route is scheduled for discard */
 257
 258 /* Route is valid for propagation (may depend on other flags in the future), accepts NULL */
 259 static inline int rte_is_valid(rte *r) { return r && !(r->flags & REF_FILTERED); }
 260
 261 /* Route just has REF_FILTERED flag */
 262 static inline int rte_is_filtered(rte *r) { return !!(r->flags & REF_FILTERED); }
 263
 264
 265 /* Types of route announcement, also used as flags */
 266 #define RA_UNDEF        0               /* Undefined RA type */
 267 #define RA_OPTIMAL      1               /* Announcement of optimal route change */
 268 #define RA_ACCEPTED     2               /* Announcement of first accepted route */
 269 #define RA_ANY          3               /* Announcement of any route change */
 270 #define RA_MERGED       4               /* Announcement of optimal route merged with next ones */
 271
 272 /* Return value of import_control() callback */
 273 #define RIC_ACCEPT      1               /* Accepted by protocol */
 274 #define RIC_PROCESS     0               /* Process it through import filter */
 275 #define RIC_REJECT      -1              /* Rejected by protocol */
 276 #define RIC_DROP        -2              /* Silently dropped by protocol */
 277
 278 struct config;
 279
 280 void rt_init(void);
 281 void rt_preconfig(struct config *);
 282 void rt_commit(struct config *new, struct config *old);
 283 void rt_lock_table(rtable *);
 284 void rt_unlock_table(rtable *);
 285 void rt_setup(pool *, rtable *, char *, struct rtable_config *);
 286 static inline net *net_find(rtable *tab, const net_addr *addr) { return (net *) fib_find(&tab->fib, addr); }
 287 static inline net *net_get(rtable *tab, const net_addr *addr) { return (net *) fib_get(&tab->fib, addr); }
 288 void *net_route(rtable *tab, const net_addr *n);
 289 int net_roa_check(rtable *tab, const net_addr *n, u32 asn);
 290 rte *rte_find(net *net, struct rte_src *src);
 291 rte *rte_get_temp(struct rta *);
 292 void rte_update2(struct channel *c, const net_addr *n, rte *new, struct rte_src *src);
 293 /* rte_update() moved to protocol.h to avoid dependency conflicts */
 294 int rt_examine(rtable *t, net_addr *a, struct proto *p, struct filter *filter);
 295 rte *rt_export_merged(struct channel *c, net *net, rte **rt_free, struct ea_list **tmpa, linpool *pool, int silent);
 296 void rt_refresh_begin(rtable *t, struct channel *c);
 297 void rt_refresh_end(rtable *t, struct channel *c);
 298 void rt_schedule_prune(rtable *t);
 299 void rte_dump(rte *);
 300 void rte_free(rte *);
 301 rte *rte_do_cow(rte *);
 302 static inline rte * rte_cow(rte *r) { return (r->flags & REF_COW) ? rte_do_cow(r) : r; }
 303 rte *rte_cow_rta(rte *r, linpool *lp);
 304 void rt_dump(rtable *);
 305 void rt_dump_all(void);
 306 int rt_feed_channel(struct channel *c);
 307 void rt_feed_channel_abort(struct channel *c);
 308 struct rtable_config *rt_new_table(struct symbol *s, uint addr_type);
 309
 310
 311 struct rt_show_data {
 312   net_addr *addr;
 313   rtable *table;
 314   struct filter *filter;
 315   int verbose;
 316   struct fib_iterator fit;
 317   struct proto *show_protocol;
 318   struct proto *export_protocol;
 319   struct channel *export_channel;
 320   int export_mode, primary_only, filtered;
 321   struct config *running_on_config;
 322   int net_counter, rt_counter, show_counter;
 323   int stats, show_for;
 324 };
 325 void rt_show(struct rt_show_data *);
 326
 327 /* Value of export_mode in struct rt_show_data */
 328 #define RSEM_NONE       0               /* Export mode not used */
 329 #define RSEM_PREEXPORT  1               /* Routes ready for export, before filtering */
 330 #define RSEM_EXPORT     2               /* Routes accepted by export filter */
 331 #define RSEM_NOEXPORT   3               /* Routes rejected by export filter */
 332
 333 /*
 334  *      Route Attributes
 335  *
 336  *      Beware: All standard BGP attributes must be represented here instead
 337  *      of making them local to the route. This is needed to ensure proper
 338  *      construction of BGP route attribute lists.
 339  */
 340
 341 /* Nexthop structure */
 342 struct nexthop {
 343   ip_addr gw;                           /* Next hop */
 344   struct iface *iface;                  /* Outgoing interface */
 345   struct nexthop *next;
 346   byte weight;
 347   byte labels_orig;                     /* Number of labels before hostentry was applied */
 348   byte labels;                          /* Number of all labels */
 349   u32 label[0];
 350 };
 351
 352 struct rte_src {
 353   struct rte_src *next;                 /* Hash chain */
 354   struct proto *proto;                  /* Protocol the source is based on */
 355   u32 private_id;                       /* Private ID, assigned by the protocol */
 356   u32 global_id;                        /* Globally unique ID of the source */
 357   unsigned uc;                          /* Use count */
 358 };
 359
 360
 361 typedef struct rta {
 362   struct rta *next, **pprev;            /* Hash chain */
 363   u32 uc;                               /* Use count */
 364   u32 hash_key;                         /* Hash over important fields */
 365   struct ea_list *eattrs;               /* Extended Attribute chain */
 366   struct rte_src *src;                  /* Route source that created the route */
 367   struct hostentry *hostentry;          /* Hostentry for recursive next-hops */
 368   ip_addr from;                         /* Advertising router */
 369   u32 igp_metric;                       /* IGP metric to next hop (for iBGP routes) */
 370   u8 source;                            /* Route source (RTS_...) */
 371   u8 scope;                             /* Route scope (SCOPE_... -- see ip.h) */
 372   u8 dest;                              /* Route destination type (RTD_...) */
 373   u8 aflags;
 374   struct nexthop nh;                    /* Next hop */
 375 } rta;
 376
 377 #define RTS_DUMMY 0                     /* Dummy route to be removed soon */
 378 #define RTS_STATIC 1                    /* Normal static route */
 379 #define RTS_INHERIT 2                   /* Route inherited from kernel */
 380 #define RTS_DEVICE 3                    /* Device route */
 381 #define RTS_STATIC_DEVICE 4             /* Static device route */
 382 #define RTS_REDIRECT 5                  /* Learned via redirect */
 383 #define RTS_RIP 6                       /* RIP route */
 384 #define RTS_OSPF 7                      /* OSPF route */
 385 #define RTS_OSPF_IA 8                   /* OSPF inter-area route */
 386 #define RTS_OSPF_EXT1 9                 /* OSPF external route type 1 */
 387 #define RTS_OSPF_EXT2 10                /* OSPF external route type 2 */
 388 #define RTS_BGP 11                      /* BGP route */
 389 #define RTS_PIPE 12                     /* Inter-table wormhole */
 390 #define RTS_BABEL 13                    /* Babel route */
 391 #define RTS_RPKI 14                     /* Route Origin Authorization */
 392
 393
 394 #define RTC_UNICAST 0
 395 #define RTC_BROADCAST 1
 396 #define RTC_MULTICAST 2
 397 #define RTC_ANYCAST 3                   /* IPv6 Anycast */
 398
 399 #define RTD_NONE 0                      /* Undefined next hop */
 400 #define RTD_UNICAST 1                   /* Next hop is neighbor router */
 401 #define RTD_BLACKHOLE 2                 /* Silently drop packets */
 402 #define RTD_UNREACHABLE 3               /* Reject as unreachable */
 403 #define RTD_PROHIBIT 4                  /* Administratively prohibited */
 404 #define RTD_MAX 5
 405
 406                                         /* Flags for net->n.flags, used by kernel syncer */
 407 #define KRF_INSTALLED 0x80              /* This route should be installed in the kernel */
 408 #define KRF_SYNC_ERROR 0x40             /* Error during kernel table synchronization */
 409
 410 #define RTAF_CACHED 1                   /* This is a cached rta */
 411
 412 #define IGP_METRIC_UNKNOWN 0x80000000   /* Default igp_metric used when no other
 413                                            protocol-specific metric is availabe */
 414
 415
 416 const char * rta_dest_names[RTD_MAX];
 417
 418 static inline const char *rta_dest_name(uint n)
 419 { return (n < RTD_MAX) ? rta_dest_names[n] : "???"; }
 420
 421 /* Route has regular, reachable nexthop (i.e. not RTD_UNREACHABLE and like) */
 422 static inline int rte_is_reachable(rte *r)
 423 { return r->attrs->dest == RTD_UNICAST; }
 424
 425
 426 /*
 427  *      Extended Route Attributes
 428  */
 429
 430 typedef struct eattr {
 431   word id;                              /* EA_CODE(EAP_..., protocol-dependent ID) */
 432   byte flags;                           /* Protocol-dependent flags */
 433   byte type;                            /* Attribute type and several flags (EAF_...) */
 434   union {
 435     u32 data;
 436     struct adata *ptr;                  /* Attribute data elsewhere */
 437   } u;
 438 } eattr;
 439
 440 #define EAP_GENERIC 0                   /* Generic attributes */
 441 #define EAP_BGP 1                       /* BGP attributes */
 442 #define EAP_RIP 2                       /* RIP */
 443 #define EAP_OSPF 3                      /* OSPF */
 444 #define EAP_KRT 4                       /* Kernel route attributes */
 445 #define EAP_BABEL 5                     /* Babel attributes */
 446 #define EAP_MAX 6
 447
 448 #define EA_CODE(proto,id) (((proto) << 8) | (id))
 449 #define EA_PROTO(ea) ((ea) >> 8)
 450 #define EA_ID(ea) ((ea) & 0xff)
 451
 452 #define EA_GEN_IGP_METRIC EA_CODE(EAP_GENERIC, 0)
 453
 454 #define EA_CODE_MASK 0xffff
 455 #define EA_ALLOW_UNDEF 0x10000          /* ea_find: allow EAF_TYPE_UNDEF */
 456 #define EA_BIT(n) ((n) << 24)           /* Used in bitfield accessors */
 457
 458 #define EAF_TYPE_MASK 0x1f              /* Mask with this to get type */
 459 #define EAF_TYPE_INT 0x01               /* 32-bit unsigned integer number */
 460 #define EAF_TYPE_OPAQUE 0x02            /* Opaque byte string (not filterable) */
 461 #define EAF_TYPE_IP_ADDRESS 0x04        /* IP address */
 462 #define EAF_TYPE_ROUTER_ID 0x05         /* Router ID (IPv4 address) */
 463 #define EAF_TYPE_AS_PATH 0x06           /* BGP AS path (encoding per RFC 1771:4.3) */
 464 #define EAF_TYPE_BITFIELD 0x09          /* 32-bit embedded bitfield */
 465 #define EAF_TYPE_INT_SET 0x0a           /* Set of u32's (e.g., a community list) */
 466 #define EAF_TYPE_EC_SET 0x0e            /* Set of pairs of u32's - ext. community list */
 467 #define EAF_TYPE_LC_SET 0x12            /* Set of triplets of u32's - large community list */
 468 #define EAF_TYPE_UNDEF 0x1f             /* `force undefined' entry */
 469 #define EAF_EMBEDDED 0x01               /* Data stored in eattr.u.data (part of type spec) */
 470 #define EAF_VAR_LENGTH 0x02             /* Attribute length is variable (part of type spec) */
 471 #define EAF_ORIGINATED 0x20             /* The attribute has originated locally */
 472 #define EAF_FRESH 0x40                  /* An uncached attribute (e.g. modified in export filter) */
 473 #define EAF_TEMP 0x80                   /* A temporary attribute (the one stored in the tmp attr list) */
 474
 475 typedef struct adata {
 476   uint length;                          /* Length of data */
 477   byte data[0];
 478 } adata;
 479
 480 static inline struct adata *
 481 lp_alloc_adata(struct linpool *pool, uint len)
 482 {
 483   struct adata *ad = lp_alloc(pool, sizeof(struct adata) + len);
 484   ad->length = len;
 485   return ad;
 486 }
 487
 488 static inline int adata_same(struct adata *a, struct adata *b)
 489 { return (a->length == b->length && !memcmp(a->data, b->data, a->length)); }
 490
 491
 492 typedef struct ea_list {
 493   struct ea_list *next;                 /* In case we have an override list */
 494   byte flags;                           /* Flags: EALF_... */
 495   byte rfu;
 496   word count;                           /* Number of attributes */
 497   eattr attrs[0];                       /* Attribute definitions themselves */
 498 } ea_list;
 499
 500 #define EALF_SORTED 1                   /* Attributes are sorted by code */
 501 #define EALF_BISECT 2                   /* Use interval bisection for searching */
 502 #define EALF_CACHED 4                   /* Attributes belonging to cached rta */
 503
 504 struct rte_src *rt_find_source(struct proto *p, u32 id);
 505 struct rte_src *rt_get_source(struct proto *p, u32 id);
 506 static inline void rt_lock_source(struct rte_src *src) { src->uc++; }
 507 static inline void rt_unlock_source(struct rte_src *src) { src->uc--; }
 508 void rt_prune_sources(void);
 509
 510 struct ea_walk_state {
 511   ea_list *eattrs;                      /* Ccurrent ea_list, initially set by caller */
 512   eattr *ea;                            /* Current eattr, initially NULL */
 513   u32 visited[4];                       /* Bitfield, limiting max to 128 */
 514 };
 515
 516 eattr *ea_find(ea_list *, unsigned ea);
 517 eattr *ea_walk(struct ea_walk_state *s, uint id, uint max);
 518 int ea_get_int(ea_list *, unsigned ea, int def);
 519 void ea_dump(ea_list *);
 520 void ea_sort(ea_list *);                /* Sort entries in all sub-lists */
 521 unsigned ea_scan(ea_list *);            /* How many bytes do we need for merged ea_list */
 522 void ea_merge(ea_list *from, ea_list *to); /* Merge sub-lists to allocated buffer */
 523 int ea_same(ea_list *x, ea_list *y);    /* Test whether two ea_lists are identical */
 524 uint ea_hash(ea_list *e);       /* Calculate 16-bit hash value */
 525 ea_list *ea_append(ea_list *to, ea_list *what);
 526 void ea_format_bitfield(struct eattr *a, byte *buf, int bufsize, const char **names, int min, int max);
 527
 528 #define NEXTHOP_MAX_SIZE (sizeof(struct nexthop) + sizeof(u32)*MPLS_MAX_LABEL_STACK)
 529
 530 static inline size_t nexthop_size(const struct nexthop *nh)
 531 { return sizeof(struct nexthop) + sizeof(u32)*nh->labels; }
 532 int nexthop__same(struct nexthop *x, struct nexthop *y); /* Compare multipath nexthops */
 533 static inline int nexthop_same(struct nexthop *x, struct nexthop *y)
 534 { return (x == y) || nexthop__same(x, y); }
 535 struct nexthop *nexthop_merge(struct nexthop *x, struct nexthop *y, int rx, int ry, int max, linpool *lp);
 536 static inline void nexthop_link(struct rta *a, struct nexthop *from)
 537 { memcpy(&a->nh, from, nexthop_size(from)); }
 538 void nexthop_insert(struct nexthop **n, struct nexthop *y);
 539 int nexthop_is_sorted(struct nexthop *x);
 540
 541 void rta_init(void);
 542 static inline size_t rta_size(const rta *a) { return sizeof(rta) + sizeof(u32)*a->nh.labels; }
 543 #define RTA_MAX_SIZE (sizeof(rta) + sizeof(u32)*MPLS_MAX_LABEL_STACK)
 544 rta *rta_lookup(rta *);                 /* Get rta equivalent to this one, uc++ */
 545 static inline int rta_is_cached(rta *r) { return r->aflags & RTAF_CACHED; }
 546 static inline rta *rta_clone(rta *r) { r->uc++; return r; }
 547 void rta__free(rta *r);
 548 static inline void rta_free(rta *r) { if (r && !--r->uc) rta__free(r); }
 549 rta *rta_do_cow(rta *o, linpool *lp);
 550 static inline rta * rta_cow(rta *r, linpool *lp) { return rta_is_cached(r) ? rta_do_cow(r, lp) : r; }
 551 void rta_dump(rta *);
 552 void rta_dump_all(void);
 553 void rta_show(struct cli *, rta *, ea_list *);
 554 void rta_set_recursive_next_hop(rtable *dep, rta *a, rtable *tab, ip_addr gw, ip_addr ll, mpls_label_stack *mls);
 555
 556 /*
 557  * rta_set_recursive_next_hop() acquires hostentry from hostcache and fills
 558  * rta->hostentry field.  New hostentry has zero use count. Cached rta locks its
 559  * hostentry (increases its use count), uncached rta does not lock it. Hostentry
 560  * with zero use count is removed asynchronously during host cache update,
 561  * therefore it is safe to hold such hostentry temorarily. Hostentry holds a
 562  * lock for a 'source' rta, mainly to share multipath nexthops.
 563  *
 564  * There is no need to hold a lock for hostentry->dep table, because that table
 565  * contains routes responsible for that hostentry, and therefore is non-empty if
 566  * given hostentry has non-zero use count. If the hostentry has zero use count,
 567  * the entry is removed before dep is referenced.
 568  *
 569  * The protocol responsible for routes with recursive next hops should hold a
 570  * lock for a 'source' table governing that routes (argument tab to
 571  * rta_set_recursive_next_hop()), because its routes reference hostentries
 572  * (through rta) related to the governing table. When all such routes are
 573  * removed, rtas are immediately removed achieving zero uc. Then the 'source'
 574  * table lock could be immediately released, although hostentries may still
 575  * exist - they will be freed together with the 'source' table.
 576  */
 577
 578 static inline void rt_lock_hostentry(struct hostentry *he) { if (he) he->uc++; }
 579 static inline void rt_unlock_hostentry(struct hostentry *he) { if (he) he->uc--; }
 580
 581
 582 extern struct protocol *attr_class_to_protocol[EAP_MAX];
 583
 584 /*
 585  *      Default protocol preferences
 586  */
 587
 588 #define DEF_PREF_DIRECT         240     /* Directly connected */
 589 #define DEF_PREF_STATIC         200     /* Static route */
 590 #define DEF_PREF_OSPF           150     /* OSPF intra-area, inter-area and type 1 external routes */
 591 #define DEF_PREF_BABEL          130     /* Babel */
 592 #define DEF_PREF_RIP            120     /* RIP */
 593 #define DEF_PREF_BGP            100     /* BGP */
 594 #define DEF_PREF_RPKI           100     /* RPKI */
 595 #define DEF_PREF_INHERITED      10      /* Routes inherited from other routing daemons */
 596
 597 /*
 598  *      Route Origin Authorization
 599  */
 600
 601 #define ROA_UNKNOWN     0
 602 #define ROA_VALID       1
 603 #define ROA_INVALID     2
 604
 605 #endif