proto/bgp/bgp.h

   1 /*
   2  *      BIRD -- The Border Gateway Protocol
   3  *
   4  *      (c) 2000 Martin Mares <mj@ucw.cz>
   5  *      (c) 2008--2016 Ondrej Zajicek <santiago@crfreenet.org>
   6  *      (c) 2008--2016 CZ.NIC z.s.p.o.
   7  *
   8  *      Can be freely distributed and used under the terms of the GNU GPL.
   9  */
  10
  11 #ifndef _BIRD_BGP_H_
  12 #define _BIRD_BGP_H_
  13
  14 #include <stdint.h>
  15 #include <setjmp.h>
  16 #include "nest/bird.h"
  17 #include "nest/route.h"
  18 #include "nest/bfd.h"
  19 //#include "lib/lists.h"
  20 #include "lib/hash.h"
  21 #include "lib/socket.h"
  22
  23 struct linpool;
  24 struct eattr;
  25
  26
  27 /* Address families */
  28
  29 #define BGP_AFI_IPV4            1
  30 #define BGP_AFI_IPV6            2
  31
  32 #define BGP_SAFI_UNICAST        1
  33 #define BGP_SAFI_MULTICAST      2
  34 #define BGP_SAFI_MPLS           4
  35 #define BGP_SAFI_MPLS_VPN       128
  36 #define BGP_SAFI_FLOW           133
  37
  38 /* Internal AF codes */
  39
  40 #define BGP_AF(A, B)            (((u32)(A) << 16) | (u32)(B))
  41 #define BGP_AFI(A)              ((u32)(A) >> 16)
  42 #define BGP_SAFI(A)             ((u32)(A) & 0xFFFF)
  43
  44 #define BGP_AF_IPV4             BGP_AF( BGP_AFI_IPV4, BGP_SAFI_UNICAST )
  45 #define BGP_AF_IPV6             BGP_AF( BGP_AFI_IPV6, BGP_SAFI_UNICAST )
  46 #define BGP_AF_IPV4_MC          BGP_AF( BGP_AFI_IPV4, BGP_SAFI_MULTICAST )
  47 #define BGP_AF_IPV6_MC          BGP_AF( BGP_AFI_IPV6, BGP_SAFI_MULTICAST )
  48 #define BGP_AF_IPV4_MPLS        BGP_AF( BGP_AFI_IPV4, BGP_SAFI_MPLS )
  49 #define BGP_AF_IPV6_MPLS        BGP_AF( BGP_AFI_IPV6, BGP_SAFI_MPLS )
  50 #define BGP_AF_VPN4_MPLS        BGP_AF( BGP_AFI_IPV4, BGP_SAFI_MPLS_VPN )
  51 #define BGP_AF_VPN6_MPLS        BGP_AF( BGP_AFI_IPV6, BGP_SAFI_MPLS_VPN )
  52 #define BGP_AF_FLOW4            BGP_AF( BGP_AFI_IPV4, BGP_SAFI_FLOW )
  53 #define BGP_AF_FLOW6            BGP_AF( BGP_AFI_IPV6, BGP_SAFI_FLOW )
  54
  55
  56 struct bgp_write_state;
  57 struct bgp_parse_state;
  58 struct bgp_export_state;
  59 struct bgp_bucket;
  60
  61 struct bgp_af_desc {
  62   u32 afi;
  63   u32 net;
  64   u8 mpls;
  65   u8 no_igp;
  66   const char *name;
  67   uint (*encode_nlri)(struct bgp_write_state *s, struct bgp_bucket *buck, byte *buf, uint size);
  68   void (*decode_nlri)(struct bgp_parse_state *s, byte *pos, uint len, rta *a);
  69   void (*update_next_hop)(struct bgp_export_state *s, eattr *nh, ea_list **to);
  70   uint (*encode_next_hop)(struct bgp_write_state *s, eattr *nh, byte *buf, uint size);
  71   void (*decode_next_hop)(struct bgp_parse_state *s, byte *pos, uint len, rta *a);
  72 };
  73
  74
  75 struct bgp_config {
  76   struct proto_config c;
  77   u32 local_as, remote_as;
  78   ip_addr local_ip;                     /* Source address to use */
  79   ip_addr remote_ip;
  80   struct iface *iface;                  /* Interface for link-local addresses */
  81   u16 local_port;                       /* Local listening port */
  82   u16 remote_port;                      /* Neighbor destination port */
  83   int multihop;                         /* Number of hops if multihop */
  84   int strict_bind;                      /* Bind listening socket to local address */
  85   int ttl_security;                     /* Enable TTL security [RFC 5082] */
  86   int compare_path_lengths;             /* Use path lengths when selecting best route */
  87   int med_metric;                       /* Compare MULTI_EXIT_DISC even between routes from differen ASes */
  88   int igp_metric;                       /* Use IGP metrics when selecting best route */
  89   int prefer_older;                     /* Prefer older routes according to RFC 5004 */
  90   int deterministic_med;                /* Use more complicated algo to have strict RFC 4271 MED comparison */
  91   u32 default_local_pref;               /* Default value for LOCAL_PREF attribute */
  92   u32 default_med;                      /* Default value for MULTI_EXIT_DISC attribute */
  93   int capabilities;                     /* Enable capability handshake [RFC 5492] */
  94   int enable_refresh;                   /* Enable local support for route refresh [RFC 2918] */
  95   int enable_as4;                       /* Enable local support for 4B AS numbers [RFC 6793] */
  96   int enable_extended_messages;         /* Enable local support for extended messages [draft] */
  97   u32 rr_cluster_id;                    /* Route reflector cluster ID, if different from local ID */
  98   int rr_client;                        /* Whether neighbor is RR client of me */
  99   int rs_client;                        /* Whether neighbor is RS client of me */
 100   u32 confederation;                    /* Confederation ID, or zero if confeds not active */
 101   int confederation_member;             /* Whether neighbor AS is member of our confederation */
 102   int passive;                          /* Do not initiate outgoing connection */
 103   int interpret_communities;            /* Hardwired handling of well-known communities */
 104   int allow_local_as;                   /* Allow that number of local ASNs in incoming AS_PATHs */
 105   int gr_mode;                          /* Graceful restart mode (BGP_GR_*) */
 106   int setkey;                           /* Set MD5 password to system SA/SP database */
 107   unsigned gr_time;                     /* Graceful restart timeout */
 108   unsigned connect_delay_time;          /* Minimum delay between connect attempts */
 109   unsigned connect_retry_time;          /* Timeout for connect attempts */
 110   unsigned hold_time, initial_hold_time;
 111   unsigned keepalive_time;
 112   unsigned error_amnesia_time;          /* Errors are forgotten after */
 113   unsigned error_delay_time_min;        /* Time to wait after an error is detected */
 114   unsigned error_delay_time_max;
 115   unsigned disable_after_error;         /* Disable the protocol when error is detected */
 116
 117   char *password;                       /* Password used for MD5 authentication */
 118   int check_link;                       /* Use iface link state for liveness detection */
 119   int bfd;                              /* Use BFD for liveness detection */
 120 };
 121
 122 struct bgp_channel_config {
 123   struct channel_config c;
 124
 125   u32 afi;
 126   const struct bgp_af_desc *desc;
 127
 128   ip_addr next_hop_addr;                /* Local address for NEXT_HOP attribute */
 129   u8 next_hop_self;                     /* Always set next hop to local IP address */
 130   u8 next_hop_keep;                     /* Do not touch next hop attribute */
 131   u8 missing_lladdr;                    /* What we will do when we don' know link-local addr, see MLL_* */
 132   u8 gw_mode;                           /* How we compute route gateway from next_hop attr, see GW_* */
 133   u8 secondary;                         /* Accept also non-best routes (i.e. RA_ACCEPTED) */
 134   u8 gr_able;                           /* Allow full graceful restart for the channel */
 135   u8 ext_next_hop;                      /* Allow both IPv4 and IPv6 next hops */
 136   u8 add_path;                          /* Use ADD-PATH extension [RFC 7911] */
 137
 138   uint rest[0];                         /* Remaining items are reconfigured separately */
 139   struct rtable_config *igp_table_ip4;  /* Table for recursive IPv4 next hop lookups */
 140   struct rtable_config *igp_table_ip6;  /* Table for recursive IPv6 next hop lookups */
 141 };
 142
 143 #define MLL_SELF 1
 144 #define MLL_DROP 2
 145 #define MLL_IGNORE 3
 146
 147 #define GW_DIRECT 1
 148 #define GW_RECURSIVE 2
 149
 150 #define BGP_ADD_PATH_RX         1
 151 #define BGP_ADD_PATH_TX         2
 152 #define BGP_ADD_PATH_FULL       3
 153
 154 #define BGP_GR_ABLE             1
 155 #define BGP_GR_AWARE            2
 156
 157 /* For GR capability common flags */
 158 #define BGP_GRF_RESTART 0x80
 159
 160 /* For GR capability per-AF flags */
 161 #define BGP_GRF_FORWARDING 0x80
 162
 163
 164 struct bgp_af_caps {
 165   u32 afi;
 166   u8 ready;                             /* Multiprotocol capability, RFC 4760 */
 167   u8 gr_able;                           /* Graceful restart support, RFC 4724 */
 168   u8 gr_af_flags;                       /* Graceful restart per-AF flags */
 169   u8 ext_next_hop;                      /* Extended IPv6 next hop,   RFC 5549 */
 170   u8 add_path;                          /* Multiple paths support,   RFC 7911 */
 171 };
 172
 173 struct bgp_caps {
 174   u32 as4_number;                       /* Announced ASN */
 175
 176   u8 as4_support;                       /* Four-octet AS capability, RFC 6793 */
 177   u8 ext_messages;                      /* Extended message length,  RFC draft */
 178   u8 route_refresh;                     /* Route refresh capability, RFC 2918 */
 179   u8 enhanced_refresh;                  /* Enhanced route refresh,   RFC 7313 */
 180
 181   u8 gr_aware;                          /* Graceful restart capability, RFC 4724 */
 182   u8 gr_flags;                          /* Graceful restart flags */
 183   u16 gr_time;                          /* Graceful restart time in seconds */
 184
 185   u16 af_count;                         /* Number of af_data items */
 186
 187   struct bgp_af_caps af_data[0];        /* Per-AF capability data */
 188 };
 189
 190 #define WALK_AF_CAPS(caps,ac) \
 191   for (ac = caps->af_data; ac < &caps->af_data[caps->af_count]; ac++)
 192
 193
 194 struct bgp_socket {
 195   node n;                               /* Node in global bgp_sockets */
 196   sock *sk;                             /* Real listening socket */
 197   u32 uc;                               /* Use count */
 198 };
 199
 200 struct bgp_conn {
 201   struct bgp_proto *bgp;
 202   struct birdsock *sk;
 203   u8 state;                             /* State of connection state machine */
 204   u8 as4_session;                       /* Session uses 4B AS numbers in AS_PATH (both sides support it) */
 205   u8 ext_messages;                      /* Session uses extended message length */
 206
 207   struct bgp_caps *local_caps;
 208   struct bgp_caps *remote_caps;
 209   struct timer *connect_timer;
 210   struct timer *hold_timer;
 211   struct timer *keepalive_timer;
 212   struct event *tx_ev;
 213   u32 packets_to_send;                  /* Bitmap of packet types to be sent */
 214   u32 channels_to_send;                 /* Bitmap of channels with packets to be sent */
 215   u8 last_channel;                      /* Channel used last time for TX */
 216   u8 last_channel_count;                /* Number of times the last channel was used in succession */
 217   int notify_code, notify_subcode, notify_size;
 218   byte *notify_data;
 219
 220   uint hold_time, keepalive_time;       /* Times calculated from my and neighbor's requirements */
 221 };
 222
 223 struct bgp_proto {
 224   struct proto p;
 225   struct bgp_config *cf;                /* Shortcut to BGP configuration */
 226   u32 local_as, remote_as;
 227   u32 public_as;                        /* Externally visible ASN (local_as or confederation id) */
 228   u32 local_id;                         /* BGP identifier of this router */
 229   u32 remote_id;                        /* BGP identifier of the neighbor */
 230   u32 rr_cluster_id;                    /* Route reflector cluster ID */
 231   int start_state;                      /* Substates that partitions BS_START */
 232   u8 is_internal;                       /* Internal BGP session (local_as == remote_as) */
 233   u8 is_interior;                       /* Internal or intra-confederation BGP session */
 234   u8 as4_session;                       /* Session uses 4B AS numbers in AS_PATH (both sides support it) */
 235   u8 rr_client;                         /* Whether neighbor is RR client of me */
 236   u8 rs_client;                         /* Whether neighbor is RS client of me */
 237   u8 route_refresh;                     /* Route refresh allowed to send [RFC 2918] */
 238   u8 enhanced_refresh;                  /* Enhanced refresh is negotiated [RFC 7313] */
 239   u8 gr_ready;                          /* Neighbor could do graceful restart */
 240   u8 gr_active_num;                     /* Neighbor is doing GR, number of active channels */
 241   u8 channel_count;                     /* Number of active channels */
 242   u32 *afi_map;                         /* Map channel index -> AFI */
 243   struct bgp_channel **channel_map;     /* Map channel index -> channel */
 244   struct bgp_conn *conn;                /* Connection we have established */
 245   struct bgp_conn outgoing_conn;        /* Outgoing connection we're working with */
 246   struct bgp_conn incoming_conn;        /* Incoming connection we have neither accepted nor rejected yet */
 247   struct object_lock *lock;             /* Lock for neighbor connection */
 248   struct neighbor *neigh;               /* Neighbor entry corresponding to remote ip, NULL if multihop */
 249   struct bgp_socket *sock;              /* Shared listening socket */
 250   struct bfd_request *bfd_req;          /* BFD request, if BFD is used */
 251   ip_addr source_addr;                  /* Local address used as an advertised next hop */
 252   ip_addr link_addr;                    /* Link-local version of source_addr */
 253   struct event *event;                  /* Event for respawning and shutting process */
 254   struct timer *startup_timer;          /* Timer used to delay protocol startup due to previous errors (startup_delay) */
 255   struct timer *gr_timer;               /* Timer waiting for reestablishment after graceful restart */
 256   unsigned startup_delay;               /* Time to delay protocol startup by due to errors */
 257   bird_clock_t last_proto_error;        /* Time of last error that leads to protocol stop */
 258   u8 last_error_class;                  /* Error class of last error */
 259   u32 last_error_code;                  /* Error code of last error. BGP protocol errors
 260                                            are encoded as (bgp_err_code << 16 | bgp_err_subcode) */
 261 };
 262
 263 struct bgp_channel {
 264   struct channel c;
 265
 266   /* Rest are BGP specific data */
 267   struct bgp_channel_config *cf;
 268   pool *pool; /* XXXX */
 269
 270   u32 afi;
 271   u32 index;
 272   const struct bgp_af_desc *desc;
 273
 274   HASH(struct bgp_bucket) bucket_hash;  /* Hash table of route buckets */
 275   struct bgp_bucket *withdraw_bucket;   /* Withdrawn routes */
 276   list bucket_queue;                    /* Queue of buckets to send (struct bgp_bucket) */
 277
 278   HASH(struct bgp_prefix) prefix_hash;  /* Prefixes to be sent */
 279   slab *prefix_slab;                    /* Slab holding prefix nodes */
 280
 281   rtable *igp_table_ip4;                /* Table for recursive IPv4 next hop lookups */
 282   rtable *igp_table_ip6;                /* Table for recursive IPv6 next hop lookups */
 283   ip_addr next_hop_addr;                /* Local address for NEXT_HOP attribute */
 284   ip_addr link_addr;                    /* Link-local version of next_hop_addr */
 285
 286   u32 packets_to_send;                  /* Bitmap of packet types to be sent */
 287
 288   u8 gr_ready;                          /* Neighbor could do GR on this AF */
 289   u8 gr_active;                         /* Neighbor is doing GR and keeping fwd state */
 290
 291   u8 ext_next_hop;                      /* Session allows both IPv4 and IPv6 next hops */
 292
 293   u8 add_path_rx;                       /* Session expects receive of ADD-PATH extended NLRI */
 294   u8 add_path_tx;                       /* Session expects transmit of ADD-PATH extended NLRI */
 295
 296   u8 feed_state;                        /* Feed state (TX) for EoR, RR packets, see BFS_* */
 297   u8 load_state;                        /* Load state (RX) for EoR, RR packets, see BFS_* */
 298 };
 299
 300 struct bgp_prefix {
 301   node buck_node;                       /* Node in per-bucket list */
 302   struct bgp_prefix *next;              /* Node in prefix hash table */
 303   u32 hash;
 304   u32 path_id;
 305   net_addr net[0];
 306 };
 307
 308 struct bgp_bucket {
 309   node send_node;                       /* Node in send queue */
 310   struct bgp_bucket *next;              /* Node in bucket hash table */
 311   list prefixes;                        /* Prefixes in this bucket (struct bgp_prefix) */
 312   u32 hash;                             /* Hash over extended attributes */
 313   ea_list eattrs[0];                    /* Per-bucket extended attributes */
 314 };
 315
 316 struct bgp_export_state {
 317   struct bgp_proto *proto;
 318   struct bgp_channel *channel;
 319   struct linpool *pool;
 320
 321   struct bgp_proto *src;
 322   rte *route;
 323   int mpls;
 324
 325   u32 attrs_seen[1];
 326   uint err_withdraw;
 327 };
 328
 329 struct bgp_write_state {
 330   struct bgp_proto *proto;
 331   struct bgp_channel *channel;
 332   struct linpool *pool;
 333
 334   int as4_session;
 335   int add_path;
 336   int mpls;
 337
 338   eattr *mp_next_hop;
 339   adata *mpls_labels;
 340 };
 341
 342 struct bgp_parse_state {
 343   struct bgp_proto *proto;
 344   struct bgp_channel *channel;
 345   struct linpool *pool;
 346
 347   int as4_session;
 348   int add_path;
 349   int mpls;
 350
 351   u32 attrs_seen[256/32];
 352
 353   u32 mp_reach_af;
 354   u32 mp_unreach_af;
 355
 356   uint attr_len;
 357   uint ip_reach_len;
 358   uint ip_unreach_len;
 359   uint ip_next_hop_len;
 360   uint mp_reach_len;
 361   uint mp_unreach_len;
 362   uint mp_next_hop_len;
 363
 364   byte *attrs;
 365   byte *ip_reach_nlri;
 366   byte *ip_unreach_nlri;
 367   byte *ip_next_hop_data;
 368   byte *mp_reach_nlri;
 369   byte *mp_unreach_nlri;
 370   byte *mp_next_hop_data;
 371
 372   uint err_withdraw;
 373   uint err_subcode;
 374   jmp_buf err_jmpbuf;
 375
 376   struct hostentry *hostentry;
 377   adata *mpls_labels;
 378
 379   /* Cached state for bgp_rte_update() */
 380   u32 last_id;
 381   struct rte_src *last_src;
 382   rta *cached_rta;
 383 };
 384
 385 #define BGP_PORT                179
 386 #define BGP_VERSION             4
 387 #define BGP_HEADER_LENGTH       19
 388 #define BGP_MAX_MESSAGE_LENGTH  4096
 389 #define BGP_MAX_EXT_MSG_LENGTH  65535
 390 #define BGP_RX_BUFFER_SIZE      4096
 391 #define BGP_TX_BUFFER_SIZE      4096
 392 #define BGP_RX_BUFFER_EXT_SIZE  65535
 393 #define BGP_TX_BUFFER_EXT_SIZE  65535
 394
 395 static inline int bgp_channel_is_ipv4(struct bgp_channel *c)
 396 { return BGP_AFI(c->afi) == BGP_AFI_IPV4; }
 397
 398 static inline int bgp_channel_is_ipv6(struct bgp_channel *c)
 399 { return BGP_AFI(c->afi) == BGP_AFI_IPV6; }
 400
 401 static inline int bgp_cc_is_ipv4(struct bgp_channel_config *c)
 402 { return BGP_AFI(c->afi) == BGP_AFI_IPV4; }
 403
 404 static inline int bgp_cc_is_ipv6(struct bgp_channel_config *c)
 405 { return BGP_AFI(c->afi) == BGP_AFI_IPV6; }
 406
 407 static inline uint bgp_max_packet_length(struct bgp_conn *conn)
 408 { return conn->ext_messages ? BGP_MAX_EXT_MSG_LENGTH : BGP_MAX_MESSAGE_LENGTH; }
 409
 410 static inline void
 411 bgp_parse_error(struct bgp_parse_state *s, uint subcode)
 412 {
 413   s->err_subcode = subcode;
 414   longjmp(s->err_jmpbuf, 1);
 415 }
 416
 417 extern struct linpool *bgp_linpool;
 418 extern struct linpool *bgp_linpool2;
 419
 420
 421 void bgp_start_timer(struct timer *t, int value);
 422 void bgp_check_config(struct bgp_config *c);
 423 void bgp_error(struct bgp_conn *c, unsigned code, unsigned subcode, byte *data, int len);
 424 void bgp_close_conn(struct bgp_conn *c);
 425 void bgp_update_startup_delay(struct bgp_proto *p);
 426 void bgp_conn_enter_openconfirm_state(struct bgp_conn *conn);
 427 void bgp_conn_enter_established_state(struct bgp_conn *conn);
 428 void bgp_conn_enter_close_state(struct bgp_conn *conn);
 429 void bgp_conn_enter_idle_state(struct bgp_conn *conn);
 430 void bgp_handle_graceful_restart(struct bgp_proto *p);
 431 void bgp_graceful_restart_done(struct bgp_channel *c);
 432 void bgp_refresh_begin(struct bgp_channel *c);
 433 void bgp_refresh_end(struct bgp_channel *c);
 434 void bgp_store_error(struct bgp_proto *p, struct bgp_conn *c, u8 class, u32 code);
 435 void bgp_stop(struct bgp_proto *p, unsigned subcode);
 436
 437 struct rte_source *bgp_find_source(struct bgp_proto *p, u32 path_id);
 438 struct rte_source *bgp_get_source(struct bgp_proto *p, u32 path_id);
 439
 440
 441
 442 #ifdef LOCAL_DEBUG
 443 #define BGP_FORCE_DEBUG 1
 444 #else
 445 #define BGP_FORCE_DEBUG 0
 446 #endif
 447 #define BGP_TRACE(flags, msg, args...) do { if ((p->p.debug & flags) || BGP_FORCE_DEBUG) \
 448         log(L_TRACE "%s: " msg, p->p.name , ## args ); } while(0)
 449
 450 #define BGP_TRACE_RL(rl, flags, msg, args...) do { if ((p->p.debug & flags) || BGP_FORCE_DEBUG) \
 451         log_rl(rl, L_TRACE "%s: " msg, p->p.name , ## args ); } while(0)
 452
 453
 454 /* attrs.c */
 455
 456 static inline eattr *
 457 bgp_find_attr(ea_list *attrs, uint code)
 458 {
 459   return ea_find(attrs, EA_CODE(EAP_BGP, code));
 460 }
 461
 462 eattr *
 463 bgp_set_attr(ea_list **attrs, struct linpool *pool, uint code, uint flags, uintptr_t val);
 464
 465 static inline void
 466 bgp_set_attr_u32(ea_list **to, struct linpool *pool, uint code, uint flags, u32 val)
 467 { bgp_set_attr(to, pool, code, flags, (uintptr_t) val); }
 468
 469 static inline void
 470 bgp_set_attr_ptr(ea_list **to, struct linpool *pool, uint code, uint flags, struct adata *val)
 471 { bgp_set_attr(to, pool, code, flags, (uintptr_t) val); }
 472
 473 static inline void
 474 bgp_set_attr_data(ea_list **to, struct linpool *pool, uint code, uint flags, void *data, uint len)
 475 {
 476   struct adata *a = lp_alloc_adata(pool, len);
 477   memcpy(a->data, data, len);
 478   bgp_set_attr(to, pool, code, flags, (uintptr_t) a);
 479 }
 480
 481 static inline void
 482 bgp_unset_attr(ea_list **to, struct linpool *pool, uint code)
 483 { eattr *e = bgp_set_attr(to, pool, code, 0, 0); e->type = EAF_TYPE_UNDEF; }
 484
 485
 486 int bgp_encode_attrs(struct bgp_write_state *s, ea_list *attrs, byte *buf, byte *end);
 487 ea_list * bgp_decode_attrs(struct bgp_parse_state *s, byte *data, uint len);
 488
 489 void bgp_init_bucket_table(struct bgp_channel *c);
 490 void bgp_free_bucket(struct bgp_channel *c, struct bgp_bucket *b);
 491 void bgp_defer_bucket(struct bgp_channel *c, struct bgp_bucket *b);
 492 void bgp_withdraw_bucket(struct bgp_channel *c, struct bgp_bucket *b);
 493
 494 void bgp_init_prefix_table(struct bgp_channel *c);
 495 void bgp_free_prefix(struct bgp_channel *c, struct bgp_prefix *bp);
 496
 497 int bgp_rte_better(struct rte *, struct rte *);
 498 int bgp_rte_mergable(rte *pri, rte *sec);
 499 int bgp_rte_recalculate(rtable *table, net *net, rte *new, rte *old, rte *old_best);
 500 void bgp_rt_notify(struct proto *P, struct channel *C, net *n, rte *new, rte *old, ea_list *attrs);
 501 int bgp_import_control(struct proto *, struct rte **, struct ea_list **, struct linpool *);
 502 int bgp_get_attr(struct eattr *e, byte *buf, int buflen);
 503 void bgp_get_route_info(struct rte *, byte *buf, struct ea_list *attrs);
 504
 505
 506 /* packets.c */
 507
 508 void mrt_dump_bgp_state_change(struct bgp_conn *conn, unsigned old, unsigned new);
 509 const struct bgp_af_desc *bgp_get_af_desc(u32 afi);
 510 const struct bgp_af_caps *bgp_find_af_caps(struct bgp_caps *caps, u32 afi);
 511 void bgp_schedule_packet(struct bgp_conn *conn, struct bgp_channel *c, int type);
 512 void bgp_kick_tx(void *vconn);
 513 void bgp_tx(struct birdsock *sk);
 514 int bgp_rx(struct birdsock *sk, uint size);
 515 const char * bgp_error_dsc(unsigned code, unsigned subcode);
 516 void bgp_log_error(struct bgp_proto *p, u8 class, char *msg, unsigned code, unsigned subcode, byte *data, unsigned len);
 517
 518 void bgp_update_next_hop(struct bgp_export_state *s, eattr *a, ea_list **to);
 519
 520
 521 /* Packet types */
 522
 523 #define PKT_OPEN                0x01
 524 #define PKT_UPDATE              0x02
 525 #define PKT_NOTIFICATION        0x03
 526 #define PKT_KEEPALIVE           0x04
 527 #define PKT_ROUTE_REFRESH       0x05    /* [RFC2918] */
 528 #define PKT_BEGIN_REFRESH       0x1e    /* Dummy type for BoRR packet [RFC7313] */
 529 #define PKT_SCHEDULE_CLOSE      0x1f    /* Used internally to schedule socket close */
 530
 531 /* Attributes */
 532
 533 #define BAF_OPTIONAL            0x80
 534 #define BAF_TRANSITIVE          0x40
 535 #define BAF_PARTIAL             0x20
 536 #define BAF_EXT_LEN             0x10
 537
 538 #define BA_ORIGIN               0x01    /* RFC 4271 */          /* WM */
 539 #define BA_AS_PATH              0x02                            /* WM */
 540 #define BA_NEXT_HOP             0x03                            /* WM */
 541 #define BA_MULTI_EXIT_DISC      0x04                            /* ON */
 542 #define BA_LOCAL_PREF           0x05                            /* WD */
 543 #define BA_ATOMIC_AGGR          0x06                            /* WD */
 544 #define BA_AGGREGATOR           0x07                            /* OT */
 545 #define BA_COMMUNITY            0x08    /* RFC 1997 */          /* OT */
 546 #define BA_ORIGINATOR_ID        0x09    /* RFC 4456 */          /* ON */
 547 #define BA_CLUSTER_LIST         0x0a    /* RFC 4456 */          /* ON */
 548 #define BA_MP_REACH_NLRI        0x0e    /* RFC 4760 */
 549 #define BA_MP_UNREACH_NLRI      0x0f    /* RFC 4760 */
 550 #define BA_EXT_COMMUNITY        0x10    /* RFC 4360 */
 551 #define BA_AS4_PATH             0x11    /* RFC 6793 */
 552 #define BA_AS4_AGGREGATOR       0x12    /* RFC 6793 */
 553 #define BA_LARGE_COMMUNITY      0x20    /* RFC 8092 */
 554
 555 /* Bird's private internal BGP attributes */
 556 #define BA_MPLS_LABEL_STACK     0xfe    /* MPLS label stack transfer attribute */
 557
 558 /* BGP connection states */
 559
 560 #define BS_IDLE                 0
 561 #define BS_CONNECT              1       /* Attempting to connect */
 562 #define BS_ACTIVE               2       /* Waiting for connection retry & listening */
 563 #define BS_OPENSENT             3
 564 #define BS_OPENCONFIRM          4
 565 #define BS_ESTABLISHED          5
 566 #define BS_CLOSE                6       /* Used during transition to BS_IDLE */
 567
 568 #define BS_MAX                  7
 569
 570 /* BGP start states
 571  *
 572  * Used in PS_START for fine-grained specification of starting state.
 573  *
 574  * When BGP protocol is started by core, it goes to BSS_PREPARE. When BGP
 575  * protocol done what is neccessary to start itself (like acquiring the lock),
 576  * it goes to BSS_CONNECT.
 577  */
 578
 579 #define BSS_PREPARE             0       /* Used before ordinary BGP started, i. e. waiting for lock */
 580 #define BSS_DELAY               1       /* Startup delay due to previous errors */
 581 #define BSS_CONNECT             2       /* Ordinary BGP connecting */
 582
 583
 584 /* BGP feed states (TX)
 585  *
 586  * RFC 4724 specifies that an initial feed should end with End-of-RIB mark.
 587  *
 588  * RFC 7313 specifies that a route refresh should be demarcated by BoRR and EoRR packets.
 589  *
 590  * These states (stored in c->feed_state) are used to keep track of these
 591  * requirements. When such feed is started, BFS_LOADING / BFS_REFRESHING is
 592  * set. When it ended, BFS_LOADED / BFS_REFRESHED is set to schedule End-of-RIB
 593  * or EoRR packet. When the packet is sent, the state returned to BFS_NONE.
 594  *
 595  * Note that when a non-demarcated feed (e.g. plain RFC 4271 initial load
 596  * without End-of-RIB or plain RFC 2918 route refresh without BoRR/EoRR
 597  * demarcation) is active, BFS_NONE is set.
 598  *
 599  * BFS_NONE, BFS_LOADING and BFS_REFRESHING are also used as load states (RX)
 600  * with correspondent semantics (-, expecting End-of-RIB, expecting EoRR).
 601  */
 602
 603 #define BFS_NONE                0       /* No feed or original non-demarcated feed */
 604 #define BFS_LOADING             1       /* Initial feed active, End-of-RIB planned */
 605 #define BFS_LOADED              2       /* Loading done, End-of-RIB marker scheduled */
 606 #define BFS_REFRESHING          3       /* Route refresh (introduced by BoRR) active */
 607 #define BFS_REFRESHED           4       /* Refresh done, EoRR packet scheduled */
 608
 609
 610 /* Error classes */
 611
 612 #define BE_NONE                 0
 613 #define BE_MISC                 1       /* Miscellaneous error */
 614 #define BE_SOCKET               2       /* Socket error */
 615 #define BE_BGP_RX               3       /* BGP protocol error notification received */
 616 #define BE_BGP_TX               4       /* BGP protocol error notification sent */
 617 #define BE_AUTO_DOWN            5       /* Automatic shutdown */
 618 #define BE_MAN_DOWN             6       /* Manual shutdown */
 619
 620 /* Misc error codes */
 621
 622 #define BEM_NEIGHBOR_LOST       1
 623 #define BEM_INVALID_NEXT_HOP    2
 624 #define BEM_INVALID_MD5         3       /* MD5 authentication kernel request failed (possibly not supported) */
 625 #define BEM_NO_SOCKET           4
 626 #define BEM_LINK_DOWN           5
 627 #define BEM_BFD_DOWN            6
 628 #define BEM_GRACEFUL_RESTART    7
 629
 630 /* Automatic shutdown error codes */
 631
 632 #define BEA_ROUTE_LIMIT_EXCEEDED 1
 633
 634 /* Well-known communities */
 635
 636 #define BGP_COMM_NO_EXPORT              0xffffff01      /* Don't export outside local AS / confed. */
 637 #define BGP_COMM_NO_ADVERTISE           0xffffff02      /* Don't export at all */
 638 #define BGP_COMM_NO_EXPORT_SUBCONFED    0xffffff03      /* NO_EXPORT even in local confederation */
 639
 640 /* Origins */
 641
 642 #define ORIGIN_IGP              0
 643 #define ORIGIN_EGP              1
 644 #define ORIGIN_INCOMPLETE       2
 645
 646
 647 #endif