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1.1 ! misho 1: /* ! 2: * BIRD -- The Border Gateway Protocol ! 3: * ! 4: * (c) 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_BGP_H_ ! 10: #define _BIRD_BGP_H_ ! 11: ! 12: #include <stdint.h> ! 13: #include "nest/route.h" ! 14: #include "nest/bfd.h" ! 15: #include "lib/hash.h" ! 16: ! 17: struct linpool; ! 18: struct eattr; ! 19: ! 20: struct bgp_config { ! 21: struct proto_config c; ! 22: u32 local_as, remote_as; ! 23: ip_addr remote_ip; ! 24: ip_addr source_addr; /* Source address to use */ ! 25: struct iface *iface; /* Interface for link-local addresses */ ! 26: u16 remote_port; /* Neighbor destination port */ ! 27: int multihop; /* Number of hops if multihop */ ! 28: int ttl_security; /* Enable TTL security [RFC5082] */ ! 29: int next_hop_self; /* Always set next hop to local IP address */ ! 30: int next_hop_keep; /* Do not touch next hop attribute */ ! 31: int missing_lladdr; /* What we will do when we don' know link-local addr, see MLL_* */ ! 32: int gw_mode; /* How we compute route gateway from next_hop attr, see GW_* */ ! 33: int compare_path_lengths; /* Use path lengths when selecting best route */ ! 34: int med_metric; /* Compare MULTI_EXIT_DISC even between routes from differen ASes */ ! 35: int igp_metric; /* Use IGP metrics when selecting best route */ ! 36: int prefer_older; /* Prefer older routes according to RFC 5004 */ ! 37: int deterministic_med; /* Use more complicated algo to have strict RFC 4271 MED comparison */ ! 38: u32 default_local_pref; /* Default value for LOCAL_PREF attribute */ ! 39: u32 default_med; /* Default value for MULTI_EXIT_DISC attribute */ ! 40: int capabilities; /* Enable capability handshake [RFC3392] */ ! 41: int enable_refresh; /* Enable local support for route refresh [RFC2918] */ ! 42: int enable_as4; /* Enable local support for 4B AS numbers [RFC4893] */ ! 43: int enable_extended_messages; /* Enable local support for extended messages [draft] */ ! 44: u32 rr_cluster_id; /* Route reflector cluster ID, if different from local ID */ ! 45: int rr_client; /* Whether neighbor is RR client of me */ ! 46: int rs_client; /* Whether neighbor is RS client of me */ ! 47: int advertise_ipv4; /* Whether we should add IPv4 capability advertisement to OPEN message */ ! 48: int passive; /* Do not initiate outgoing connection */ ! 49: int interpret_communities; /* Hardwired handling of well-known communities */ ! 50: int secondary; /* Accept also non-best routes (i.e. RA_ACCEPTED) */ ! 51: int add_path; /* Use ADD-PATH extension [draft] */ ! 52: int allow_local_as; /* Allow that number of local ASNs in incoming AS_PATHs */ ! 53: int gr_mode; /* Graceful restart mode (BGP_GR_*) */ ! 54: int setkey; /* Set MD5 password to system SA/SP database */ ! 55: unsigned gr_time; /* Graceful restart timeout */ ! 56: unsigned connect_delay_time; /* Minimum delay between connect attempts */ ! 57: unsigned connect_retry_time; /* Timeout for connect attempts */ ! 58: unsigned hold_time, initial_hold_time; ! 59: unsigned keepalive_time; ! 60: unsigned error_amnesia_time; /* Errors are forgotten after */ ! 61: unsigned error_delay_time_min; /* Time to wait after an error is detected */ ! 62: unsigned error_delay_time_max; ! 63: unsigned disable_after_error; /* Disable the protocol when error is detected */ ! 64: ! 65: char *password; /* Password used for MD5 authentication */ ! 66: struct rtable_config *igp_table; /* Table used for recursive next hop lookups */ ! 67: int check_link; /* Use iface link state for liveness detection */ ! 68: int bfd; /* Use BFD for liveness detection */ ! 69: }; ! 70: ! 71: #define MLL_SELF 1 ! 72: #define MLL_DROP 2 ! 73: #define MLL_IGNORE 3 ! 74: ! 75: #define GW_DIRECT 1 ! 76: #define GW_RECURSIVE 2 ! 77: ! 78: #define ADD_PATH_RX 1 ! 79: #define ADD_PATH_TX 2 ! 80: #define ADD_PATH_FULL 3 ! 81: ! 82: #define BGP_GR_ABLE 1 ! 83: #define BGP_GR_AWARE 2 ! 84: ! 85: /* For peer_gr_flags */ ! 86: #define BGP_GRF_RESTART 0x80 ! 87: ! 88: /* For peer_gr_aflags */ ! 89: #define BGP_GRF_FORWARDING 0x80 ! 90: ! 91: ! 92: struct bgp_conn { ! 93: struct bgp_proto *bgp; ! 94: struct birdsock *sk; ! 95: uint state; /* State of connection state machine */ ! 96: struct timer *connect_retry_timer; ! 97: struct timer *hold_timer; ! 98: struct timer *keepalive_timer; ! 99: struct event *tx_ev; ! 100: int packets_to_send; /* Bitmap of packet types to be sent */ ! 101: int notify_code, notify_subcode, notify_size; ! 102: byte *notify_data; ! 103: u32 advertised_as; /* Temporary value for AS number received */ ! 104: int start_state; /* protocol start_state snapshot when connection established */ ! 105: u8 peer_refresh_support; /* Peer supports route refresh [RFC2918] */ ! 106: u8 peer_as4_support; /* Peer supports 4B AS numbers [RFC4893] */ ! 107: u8 peer_add_path; /* Peer supports ADD-PATH [draft] */ ! 108: u8 peer_enhanced_refresh_support; /* Peer supports enhanced refresh [RFC7313] */ ! 109: u8 peer_gr_aware; ! 110: u8 peer_gr_able; ! 111: u16 peer_gr_time; ! 112: u8 peer_gr_flags; ! 113: u8 peer_gr_aflags; ! 114: u8 peer_ext_messages_support; /* Peer supports extended message length [draft] */ ! 115: unsigned hold_time, keepalive_time; /* Times calculated from my and neighbor's requirements */ ! 116: }; ! 117: ! 118: struct bgp_proto { ! 119: struct proto p; ! 120: struct bgp_config *cf; /* Shortcut to BGP configuration */ ! 121: u32 local_as, remote_as; ! 122: int start_state; /* Substates that partitions BS_START */ ! 123: u8 is_internal; /* Internal BGP connection (local_as == remote_as) */ ! 124: u8 as4_session; /* Session uses 4B AS numbers in AS_PATH (both sides support it) */ ! 125: u8 add_path_rx; /* Session expects receive of ADD-PATH extended NLRI */ ! 126: u8 add_path_tx; /* Session expects transmit of ADD-PATH extended NLRI */ ! 127: u8 ext_messages; /* Session allows to use extended messages (both sides support it) */ ! 128: u32 local_id; /* BGP identifier of this router */ ! 129: u32 remote_id; /* BGP identifier of the neighbor */ ! 130: u32 rr_cluster_id; /* Route reflector cluster ID */ ! 131: int rr_client; /* Whether neighbor is RR client of me */ ! 132: int rs_client; /* Whether neighbor is RS client of me */ ! 133: u8 gr_ready; /* Neighbor could do graceful restart */ ! 134: u8 gr_active; /* Neighbor is doing graceful restart */ ! 135: u8 feed_state; /* Feed state (TX) for EoR, RR packets, see BFS_* */ ! 136: u8 load_state; /* Load state (RX) for EoR, RR packets, see BFS_* */ ! 137: struct bgp_conn *conn; /* Connection we have established */ ! 138: struct bgp_conn outgoing_conn; /* Outgoing connection we're working with */ ! 139: struct bgp_conn incoming_conn; /* Incoming connection we have neither accepted nor rejected yet */ ! 140: struct object_lock *lock; /* Lock for neighbor connection */ ! 141: struct neighbor *neigh; /* Neighbor entry corresponding to remote ip, NULL if multihop */ ! 142: struct bfd_request *bfd_req; /* BFD request, if BFD is used */ ! 143: ip_addr source_addr; /* Local address used as an advertised next hop */ ! 144: rtable *igp_table; /* Table used for recursive next hop lookups */ ! 145: struct event *event; /* Event for respawning and shutting process */ ! 146: struct timer *startup_timer; /* Timer used to delay protocol startup due to previous errors (startup_delay) */ ! 147: struct timer *gr_timer; /* Timer waiting for reestablishment after graceful restart */ ! 148: struct bgp_bucket **bucket_hash; /* Hash table of attribute buckets */ ! 149: uint hash_size, hash_count, hash_limit; ! 150: HASH(struct bgp_prefix) prefix_hash; /* Prefixes to be sent */ ! 151: slab *prefix_slab; /* Slab holding prefix nodes */ ! 152: list bucket_queue; /* Queue of buckets to send */ ! 153: struct bgp_bucket *withdraw_bucket; /* Withdrawn routes */ ! 154: unsigned startup_delay; /* Time to delay protocol startup by due to errors */ ! 155: bird_clock_t last_proto_error; /* Time of last error that leads to protocol stop */ ! 156: u8 last_error_class; /* Error class of last error */ ! 157: u32 last_error_code; /* Error code of last error. BGP protocol errors ! 158: are encoded as (bgp_err_code << 16 | bgp_err_subcode) */ ! 159: #ifdef IPV6 ! 160: byte *mp_reach_start, *mp_unreach_start; /* Multiprotocol BGP attribute notes */ ! 161: unsigned mp_reach_len, mp_unreach_len; ! 162: ip_addr local_link; /* Link-level version of source_addr */ ! 163: #endif ! 164: }; ! 165: ! 166: struct bgp_prefix { ! 167: struct { ! 168: ip_addr prefix; ! 169: int pxlen; ! 170: } n; ! 171: u32 path_id; ! 172: struct bgp_prefix *next; ! 173: node bucket_node; /* Node in per-bucket list */ ! 174: }; ! 175: ! 176: struct bgp_bucket { ! 177: node send_node; /* Node in send queue */ ! 178: struct bgp_bucket *hash_next, *hash_prev; /* Node in bucket hash table */ ! 179: unsigned hash; /* Hash over extended attributes */ ! 180: list prefixes; /* Prefixes in this buckets */ ! 181: ea_list eattrs[0]; /* Per-bucket extended attributes */ ! 182: }; ! 183: ! 184: #define BGP_PORT 179 ! 185: #define BGP_VERSION 4 ! 186: #define BGP_HEADER_LENGTH 19 ! 187: #define BGP_MAX_MESSAGE_LENGTH 4096 ! 188: #define BGP_MAX_EXT_MSG_LENGTH 65535 ! 189: #define BGP_RX_BUFFER_SIZE 4096 ! 190: #define BGP_TX_BUFFER_SIZE 4096 ! 191: #define BGP_RX_BUFFER_EXT_SIZE 65535 ! 192: #define BGP_TX_BUFFER_EXT_SIZE 65535 ! 193: ! 194: static inline uint bgp_max_packet_length(struct bgp_proto *p) ! 195: { return p->ext_messages ? BGP_MAX_EXT_MSG_LENGTH : BGP_MAX_MESSAGE_LENGTH; } ! 196: ! 197: extern struct linpool *bgp_linpool; ! 198: ! 199: ! 200: void bgp_start_timer(struct timer *t, int value); ! 201: void bgp_check_config(struct bgp_config *c); ! 202: void bgp_error(struct bgp_conn *c, unsigned code, unsigned subcode, byte *data, int len); ! 203: void bgp_close_conn(struct bgp_conn *c); ! 204: void bgp_update_startup_delay(struct bgp_proto *p); ! 205: void bgp_conn_enter_openconfirm_state(struct bgp_conn *conn); ! 206: void bgp_conn_enter_established_state(struct bgp_conn *conn); ! 207: void bgp_conn_enter_close_state(struct bgp_conn *conn); ! 208: void bgp_conn_enter_idle_state(struct bgp_conn *conn); ! 209: void bgp_handle_graceful_restart(struct bgp_proto *p); ! 210: void bgp_graceful_restart_done(struct bgp_proto *p); ! 211: void bgp_refresh_begin(struct bgp_proto *p); ! 212: void bgp_refresh_end(struct bgp_proto *p); ! 213: void bgp_store_error(struct bgp_proto *p, struct bgp_conn *c, u8 class, u32 code); ! 214: void bgp_stop(struct bgp_proto *p, unsigned subcode); ! 215: ! 216: struct rte_source *bgp_find_source(struct bgp_proto *p, u32 path_id); ! 217: struct rte_source *bgp_get_source(struct bgp_proto *p, u32 path_id); ! 218: ! 219: ! 220: ! 221: #ifdef LOCAL_DEBUG ! 222: #define BGP_FORCE_DEBUG 1 ! 223: #else ! 224: #define BGP_FORCE_DEBUG 0 ! 225: #endif ! 226: #define BGP_TRACE(flags, msg, args...) do { if ((p->p.debug & flags) || BGP_FORCE_DEBUG) \ ! 227: log(L_TRACE "%s: " msg, p->p.name , ## args ); } while(0) ! 228: ! 229: #define BGP_TRACE_RL(rl, flags, msg, args...) do { if ((p->p.debug & flags) || BGP_FORCE_DEBUG) \ ! 230: log_rl(rl, L_TRACE "%s: " msg, p->p.name , ## args ); } while(0) ! 231: ! 232: ! 233: /* attrs.c */ ! 234: ! 235: /* Hack: although BA_NEXT_HOP attribute has type EAF_TYPE_IP_ADDRESS, in IPv6 ! 236: * we store two addesses in it - a global address and a link local address. ! 237: */ ! 238: #ifdef IPV6 ! 239: #define NEXT_HOP_LENGTH (2*sizeof(ip_addr)) ! 240: static inline void set_next_hop(byte *b, ip_addr addr) { ((ip_addr *) b)[0] = addr; ((ip_addr *) b)[1] = IPA_NONE; } ! 241: #else ! 242: #define NEXT_HOP_LENGTH sizeof(ip_addr) ! 243: static inline void set_next_hop(byte *b, ip_addr addr) { ((ip_addr *) b)[0] = addr; } ! 244: #endif ! 245: ! 246: void bgp_attach_attr(struct ea_list **to, struct linpool *pool, unsigned attr, uintptr_t val); ! 247: byte *bgp_attach_attr_wa(struct ea_list **to, struct linpool *pool, unsigned attr, unsigned len); ! 248: struct rta *bgp_decode_attrs(struct bgp_conn *conn, byte *a, uint len, struct linpool *pool, int mandatory); ! 249: int bgp_get_attr(struct eattr *e, byte *buf, int buflen); ! 250: int bgp_rte_better(struct rte *, struct rte *); ! 251: int bgp_rte_mergable(rte *pri, rte *sec); ! 252: int bgp_rte_recalculate(rtable *table, net *net, rte *new, rte *old, rte *old_best); ! 253: void bgp_rt_notify(struct proto *P, rtable *tbl UNUSED, net *n, rte *new, rte *old UNUSED, ea_list *attrs); ! 254: int bgp_import_control(struct proto *, struct rte **, struct ea_list **, struct linpool *); ! 255: void bgp_init_bucket_table(struct bgp_proto *); ! 256: void bgp_free_bucket_table(struct bgp_proto *p); ! 257: void bgp_free_bucket(struct bgp_proto *p, struct bgp_bucket *buck); ! 258: void bgp_init_prefix_table(struct bgp_proto *p, u32 order); ! 259: void bgp_free_prefix_table(struct bgp_proto *p); ! 260: void bgp_free_prefix(struct bgp_proto *p, struct bgp_prefix *bp); ! 261: uint bgp_encode_attrs(struct bgp_proto *p, byte *w, ea_list *attrs, int remains); ! 262: void bgp_get_route_info(struct rte *, byte *buf, struct ea_list *attrs); ! 263: ! 264: inline static void bgp_attach_attr_ip(struct ea_list **to, struct linpool *pool, unsigned attr, ip_addr a) ! 265: { *(ip_addr *) bgp_attach_attr_wa(to, pool, attr, sizeof(ip_addr)) = a; } ! 266: ! 267: /* packets.c */ ! 268: ! 269: void mrt_dump_bgp_state_change(struct bgp_conn *conn, unsigned old, unsigned new); ! 270: void bgp_schedule_packet(struct bgp_conn *conn, int type); ! 271: void bgp_kick_tx(void *vconn); ! 272: void bgp_tx(struct birdsock *sk); ! 273: int bgp_rx(struct birdsock *sk, uint size); ! 274: const char * bgp_error_dsc(unsigned code, unsigned subcode); ! 275: void bgp_log_error(struct bgp_proto *p, u8 class, char *msg, unsigned code, unsigned subcode, byte *data, unsigned len); ! 276: ! 277: /* Packet types */ ! 278: ! 279: #define PKT_OPEN 0x01 ! 280: #define PKT_UPDATE 0x02 ! 281: #define PKT_NOTIFICATION 0x03 ! 282: #define PKT_KEEPALIVE 0x04 ! 283: #define PKT_ROUTE_REFRESH 0x05 /* [RFC2918] */ ! 284: #define PKT_BEGIN_REFRESH 0x1e /* Dummy type for BoRR packet [RFC7313] */ ! 285: #define PKT_SCHEDULE_CLOSE 0x1f /* Used internally to schedule socket close */ ! 286: ! 287: /* Attributes */ ! 288: ! 289: #define BAF_OPTIONAL 0x80 ! 290: #define BAF_TRANSITIVE 0x40 ! 291: #define BAF_PARTIAL 0x20 ! 292: #define BAF_EXT_LEN 0x10 ! 293: ! 294: #define BA_ORIGIN 0x01 /* [RFC1771] */ /* WM */ ! 295: #define BA_AS_PATH 0x02 /* WM */ ! 296: #define BA_NEXT_HOP 0x03 /* WM */ ! 297: #define BA_MULTI_EXIT_DISC 0x04 /* ON */ ! 298: #define BA_LOCAL_PREF 0x05 /* WD */ ! 299: #define BA_ATOMIC_AGGR 0x06 /* WD */ ! 300: #define BA_AGGREGATOR 0x07 /* OT */ ! 301: #define BA_COMMUNITY 0x08 /* [RFC1997] */ /* OT */ ! 302: #define BA_ORIGINATOR_ID 0x09 /* [RFC1966] */ /* ON */ ! 303: #define BA_CLUSTER_LIST 0x0a /* ON */ ! 304: /* We don't support these: */ ! 305: #define BA_DPA 0x0b /* ??? */ ! 306: #define BA_ADVERTISER 0x0c /* [RFC1863] */ ! 307: #define BA_RCID_PATH 0x0d ! 308: #define BA_MP_REACH_NLRI 0x0e /* [RFC2283] */ ! 309: #define BA_MP_UNREACH_NLRI 0x0f ! 310: #define BA_EXT_COMMUNITY 0x10 /* [RFC4360] */ ! 311: #define BA_AS4_PATH 0x11 /* [RFC4893] */ ! 312: #define BA_AS4_AGGREGATOR 0x12 ! 313: #define BA_LARGE_COMMUNITY 0x20 /* [draft-ietf-idr-large-community] */ ! 314: ! 315: /* BGP connection states */ ! 316: ! 317: #define BS_IDLE 0 ! 318: #define BS_CONNECT 1 /* Attempting to connect */ ! 319: #define BS_ACTIVE 2 /* Waiting for connection retry & listening */ ! 320: #define BS_OPENSENT 3 ! 321: #define BS_OPENCONFIRM 4 ! 322: #define BS_ESTABLISHED 5 ! 323: #define BS_CLOSE 6 /* Used during transition to BS_IDLE */ ! 324: ! 325: #define BS_MAX 7 ! 326: ! 327: /* BGP start states ! 328: * ! 329: * Used in PS_START for fine-grained specification of starting state. ! 330: * ! 331: * When BGP protocol is started by core, it goes to BSS_PREPARE. When BGP ! 332: * protocol done what is neccessary to start itself (like acquiring the lock), ! 333: * it goes to BSS_CONNECT. When some connection attempt failed because of ! 334: * option or capability error, it goes to BSS_CONNECT_NOCAP. ! 335: */ ! 336: ! 337: #define BSS_PREPARE 0 /* Used before ordinary BGP started, i. e. waiting for lock */ ! 338: #define BSS_DELAY 1 /* Startup delay due to previous errors */ ! 339: #define BSS_CONNECT 2 /* Ordinary BGP connecting */ ! 340: #define BSS_CONNECT_NOCAP 3 /* Legacy BGP connecting (without capabilities) */ ! 341: ! 342: ! 343: /* BGP feed states (TX) ! 344: * ! 345: * RFC 4724 specifies that an initial feed should end with End-of-RIB mark. ! 346: * ! 347: * RFC 7313 specifies that a route refresh should be demarcated by BoRR and EoRR packets. ! 348: * ! 349: * These states (stored in p->feed_state) are used to keep track of these ! 350: * requirements. When such feed is started, BFS_LOADING / BFS_REFRESHING is ! 351: * set. When it ended, BFS_LOADED / BFS_REFRESHED is set to schedule End-of-RIB ! 352: * or EoRR packet. When the packet is sent, the state returned to BFS_NONE. ! 353: * ! 354: * Note that when a non-demarcated feed (e.g. plain RFC 4271 initial load ! 355: * without End-of-RIB or plain RFC 2918 route refresh without BoRR/EoRR ! 356: * demarcation) is active, BFS_NONE is set. ! 357: * ! 358: * BFS_NONE, BFS_LOADING and BFS_REFRESHING are also used as load states (RX) ! 359: * with correspondent semantics (-, expecting End-of-RIB, expecting EoRR). ! 360: */ ! 361: ! 362: #define BFS_NONE 0 /* No feed or original non-demarcated feed */ ! 363: #define BFS_LOADING 1 /* Initial feed active, End-of-RIB planned */ ! 364: #define BFS_LOADED 2 /* Loading done, End-of-RIB marker scheduled */ ! 365: #define BFS_REFRESHING 3 /* Route refresh (introduced by BoRR) active */ ! 366: #define BFS_REFRESHED 4 /* Refresh done, EoRR packet scheduled */ ! 367: ! 368: ! 369: /* Error classes */ ! 370: ! 371: #define BE_NONE 0 ! 372: #define BE_MISC 1 /* Miscellaneous error */ ! 373: #define BE_SOCKET 2 /* Socket error */ ! 374: #define BE_BGP_RX 3 /* BGP protocol error notification received */ ! 375: #define BE_BGP_TX 4 /* BGP protocol error notification sent */ ! 376: #define BE_AUTO_DOWN 5 /* Automatic shutdown */ ! 377: #define BE_MAN_DOWN 6 /* Manual shutdown */ ! 378: ! 379: /* Misc error codes */ ! 380: ! 381: #define BEM_NEIGHBOR_LOST 1 ! 382: #define BEM_INVALID_NEXT_HOP 2 ! 383: #define BEM_INVALID_MD5 3 /* MD5 authentication kernel request failed (possibly not supported) */ ! 384: #define BEM_NO_SOCKET 4 ! 385: #define BEM_LINK_DOWN 5 ! 386: #define BEM_BFD_DOWN 6 ! 387: #define BEM_GRACEFUL_RESTART 7 ! 388: ! 389: /* Automatic shutdown error codes */ ! 390: ! 391: #define BEA_ROUTE_LIMIT_EXCEEDED 1 ! 392: ! 393: /* Well-known communities */ ! 394: ! 395: #define BGP_COMM_NO_EXPORT 0xffffff01 /* Don't export outside local AS / confed. */ ! 396: #define BGP_COMM_NO_ADVERTISE 0xffffff02 /* Don't export at all */ ! 397: #define BGP_COMM_NO_EXPORT_SUBCONFED 0xffffff03 /* NO_EXPORT even in local confederation */ ! 398: ! 399: /* Origins */ ! 400: ! 401: #define ORIGIN_IGP 0 ! 402: #define ORIGIN_EGP 1 ! 403: #define ORIGIN_INCOMPLETE 2 ! 404: ! 405: /* Address families */ ! 406: ! 407: #define BGP_AF_IPV4 1 ! 408: #define BGP_AF_IPV6 2 ! 409: ! 410: #ifdef IPV6 ! 411: #define BGP_AF BGP_AF_IPV6 ! 412: #else ! 413: #define BGP_AF BGP_AF_IPV4 ! 414: #endif ! 415: ! 416: #endif