Annotation of embedaddon/bird2/proto/ospf/rt.h, revision 1.1
1.1 ! misho 1: /*
! 2: * BIRD -- OSPF
! 3: *
! 4: * (c) 2000--2004 Ondrej Filip <feela@network.cz>
! 5: * (c) 2009--2014 Ondrej Zajicek <santiago@crfreenet.org>
! 6: * (c) 2009--2014 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_OSPF_RT_H_
! 12: #define _BIRD_OSPF_RT_H_
! 13:
! 14:
! 15: #define ORT_NET 0
! 16: #define ORT_ROUTER 1
! 17:
! 18: typedef struct orta
! 19: {
! 20: u8 type; /* RTS_OSPF_* */
! 21: u8 nhs_reuse; /* Whether nhs nodes can be reused during merging.
! 22: See a note in rt.c:add_cand() */
! 23: u32 options;
! 24: /*
! 25: * For ORT_ROUTER routes, options field are router-LSA style
! 26: * options, with V,E,B bits. In OSPFv2, ASBRs from another areas
! 27: * (that we know from rt-summary-lsa) have just ORTA_ASBR in
! 28: * options, their real options are unknown.
! 29: */
! 30: #define ORTA_ASBR OPT_RT_E
! 31: #define ORTA_ABR OPT_RT_B
! 32: /*
! 33: * For ORT_NET routes, there are just several flags for external routes:
! 34: *
! 35: * ORTA_PREF for external routes means that the route is preferred in AS
! 36: * external route selection according to 16.4.1. - it is intra-area path using
! 37: * non-backbone area. In other words, the forwarding address (or ASBR if
! 38: * forwarding address is zero) is intra-area (type == RTS_OSPF) and its area
! 39: * is not a backbone.
! 40: *
! 41: * ORTA_NSSA means that the entry represents an NSSA route, and ORTA_PROP
! 42: * means that the NSSA route has propagate-bit set. These flags are used in
! 43: * NSSA translation.
! 44: */
! 45: #define ORTA_PREF 0x80000000
! 46: #define ORTA_NSSA 0x40000000
! 47: #define ORTA_PROP 0x20000000
! 48:
! 49: u32 metric1;
! 50: u32 metric2;
! 51: u32 tag;
! 52: u32 rid; /* Router ID of real advertising router */
! 53: struct ospf_area *oa;
! 54: struct ospf_area *voa; /* Used when route is replaced in ospf_rt_sum_tr(),
! 55: NULL otherwise */
! 56: struct nexthop *nhs; /* Next hops computed during SPF */
! 57: struct top_hash_entry *en; /* LSA responsible for this orta */
! 58: }
! 59: orta;
! 60:
! 61: typedef struct ort
! 62: {
! 63: /*
! 64: * Most OSPF routing table entries are for computed OSPF routes, these have
! 65: * defined n.type. There are also few other cases: entries for configured area
! 66: * networks (these have area_net field set) and entries for external routes
! 67: * exported to OSPF (these have external_rte field set). These entries are
! 68: * kept even if they do not contain 'proper' rt entry. That is needed to keep
! 69: * allocated stable UID numbers (fn.uid), which are used as LSA IDs in OSPFv3
! 70: * (see fibnode_to_lsaid()) for related LSAs (network summary LSAs in the
! 71: * first case, external or NSSA LSAs in the second case). Entries for external
! 72: * routes also have a second purpose - to prevent NSSA translation of received
! 73: * NSSA routes if regular external routes were already originated for the same
! 74: * network (see check_nssa_lsa()).
! 75: *
! 76: * old_* values are here to represent the last route update. old_rta is cached
! 77: * (we keep reference), mainly for multipath nexthops. old_rta == NULL means
! 78: * route was not in the last update, in that case other old_* values are not
! 79: * valid.
! 80: */
! 81: orta n;
! 82: u32 old_metric1, old_metric2, old_tag, old_rid;
! 83: rta *old_rta;
! 84: u32 lsa_id;
! 85: u8 external_rte;
! 86: u8 area_net;
! 87: u8 keep;
! 88:
! 89: struct fib_node fn;
! 90: }
! 91: ort;
! 92:
! 93: static inline int rt_is_nssa(ort *nf)
! 94: { return nf->n.options & ORTA_NSSA; }
! 95:
! 96:
! 97: /*
! 98: * Invariants for structs top_hash_entry (nodes of LSA db)
! 99: * enforced by SPF calculation for final nodes (color == INSPF):
! 100: * - only router, network and AS-external LSAs
! 101: * - lsa.age < LSA_MAXAGE
! 102: * - dist < LSINFINITY (or 2*LSINFINITY for ext-LSAs)
! 103: * - nhs is non-NULL unless the node is oa->rt (calculating router itself)
! 104: * - beware, nhs is not valid after SPF calculation
! 105: *
! 106: * Invariants for structs orta nodes of fib tables po->rtf, oa->rtr:
! 107: * - nodes may be invalid (n.type == 0), in that case other invariants don't hold
! 108: * - n.metric1 may be at most a small multiple of LSINFINITY,
! 109: * therefore sums do not overflow
! 110: * - n.oa is always non-NULL
! 111: * - n.nhs is always non-NULL unless it is configured stubnet
! 112: * - n.en is non-NULL for external routes, NULL for intra/inter area routes.
! 113: * - oa->rtr does not contain calculating router itself
! 114: *
! 115: * There are four types of nexthops in nhs fields:
! 116: * - gateway nexthops (non-NULL iface, gw != IPA_NONE)
! 117: * - device nexthops (non-NULL iface, gw == IPA_NONE)
! 118: * - dummy vlink nexthops (NULL iface, gw == IPA_NONE)
! 119: * - configured stubnets (nhs is NULL, only RTS_OSPF orta nodes in po->rtf)
! 120: *
! 121: * Dummy vlink nexthops and configured stubnets cannot be mixed with
! 122: * regular ones, nhs field contains either list of gateway+device nodes,
! 123: * one vlink node, or NULL for configured stubnet.
! 124: *
! 125: * Dummy vlink nexthops can appear in both network (rtf) and backbone area router
! 126: * (rtr) tables for regular and inter-area routes, but only if areano > 1. They are
! 127: * replaced in ospf_rt_sum_tr() and removed in ospf_rt_abr1(), therefore cannot
! 128: * appear in ASBR pre-selection and external routes processing.
! 129: */
! 130:
! 131: void ospf_rt_spf(struct ospf_proto *p);
! 132: void ospf_rt_initort(struct fib_node *fn);
! 133: void ospf_update_gr_recovery(struct ospf_proto *p);
! 134:
! 135:
! 136: #endif /* _BIRD_OSPF_RT_H_ */
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>
![[BACK]](/icons/cvsweb/back.gif){kind=icon}
Return to rt.h CVS log ![[TXT]](/icons/cvsweb/text.gif){kind=icon}
![[DIR]](/icons/cvsweb/dir.gif){kind=icon}
Up to [ELWIX - Embedded LightWeight unIX -] / embedaddon / bird2 / proto / ospf