diff options
Diffstat (limited to 'proto/ospf/rt.h')
| -rw-r--r-- | proto/ospf/rt.h | 57 |
1 files changed, 30 insertions, 27 deletions
diff --git a/proto/ospf/rt.h b/proto/ospf/rt.h index 77d7080b..61936f3c 100644 --- a/proto/ospf/rt.h +++ b/proto/ospf/rt.h @@ -2,9 +2,10 @@ * BIRD -- OSPF * * (c) 2000--2004 Ondrej Filip <feela@network.cz> + * (c) 2009--2014 Ondrej Zajicek <santiago@crfreenet.org> + * (c) 2009--2014 CZ.NIC z.s.p.o. * * Can be freely distributed and used under the terms of the GNU GPL. - * */ #ifndef _BIRD_OSPF_RT_H_ @@ -28,12 +29,17 @@ typedef struct orta #define ORTA_ASBR OPT_RT_E #define ORTA_ABR OPT_RT_B /* - * For ORT_NET routes, the field is almost unused with one - * exception: ORTA_PREF for external routes means that the route is - * preferred in AS external route selection according to 16.4.1. - - * it is intra-area path using non-backbone area. In other words, - * the forwarding address (or ASBR if forwarding address is zero) is - * intra-area (type == RTS_OSPF) and its area is not a backbone. + * For ORT_NET routes, there are just several flags for external routes: + * + * ORTA_PREF for external routes means that the route is preferred in AS + * external route selection according to 16.4.1. - it is intra-area path using + * non-backbone area. In other words, the forwarding address (or ASBR if + * forwarding address is zero) is intra-area (type == RTS_OSPF) and its area + * is not a backbone. + * + * ORTA_NSSA means that the entry represents an NSSA route, and ORTA_PROP + * means that the NSSA route has propagate-bit set. These flags are used in + * NSSA translation. */ #define ORTA_PREF 0x80000000 #define ORTA_NSSA 0x40000000 @@ -51,41 +57,38 @@ typedef struct orta } orta; - -/* Values for fn.flags in struct ort */ -#define OSPF_RT_PERSISTENT 0x01 - typedef struct ort { /* - * We use OSPF_RT_PERSISTENT to mark persistent rt entries, that are - * needed for summary LSAs that don't have 'proper' rt entry (area - * networks + default to stubs) to keep uid stable (used for LSA ID - * in OSPFv3 - see fibnode_to_lsaid()). - * - * We use ORT_RT_EXPORT and ORT_RT_NSSA to note whether the - * external/NSSA route was originated from the route export (in - * ospf_rt_notify()) or from the NSSA route translation (in - * check_nssa_lsa()). + * Most OSPF routing table entries are for computed OSPF routes, these have + * defined n.type. There are also few other cases: entries for configured area + * networks (these have area_net field set) and entries for external routes + * exported to OSPF (these have external_rte field set). These entries are + * kept even if they do not contain 'proper' rt entry. That is needed to keep + * allocated stable UID numbers (fn.uid), which are used as LSA IDs in OSPFv3 + * (see fibnode_to_lsaid()) for related LSAs (network summary LSAs in the + * first case, external or NSSA LSAs in the second case). Entries for external + * routes also have a second purpose - to prevent NSSA translation of received + * NSSA routes if regular external routes were already originated for the same + * network (see check_nssa_lsa()). * - * old_* values are here to represent the last route update. old_rta - * is cached (we keep reference), mainly for multipath nexthops. - * old_rta == NULL means route was not in the last update, in that - * case other old_* values are not valid. + * old_* values are here to represent the last route update. old_rta is cached + * (we keep reference), mainly for multipath nexthops. old_rta == NULL means + * route was not in the last update, in that case other old_* values are not + * valid. */ struct fib_node fn; orta n; u32 old_metric1, old_metric2, old_tag, old_rid; rta *old_rta; u8 external_rte; + u8 area_net; } ort; static inline int rt_is_nssa(ort *nf) { return nf->n.options & ORTA_NSSA; } -#define EXT_EXPORT 1 -#define EXT_NSSA 2 /* * Invariants for structs top_hash_entry (nodes of LSA db) @@ -97,7 +100,7 @@ static inline int rt_is_nssa(ort *nf) * - beware, nhs is not valid after SPF calculation * * Invariants for structs orta nodes of fib tables po->rtf, oa->rtr: - * - nodes may be invalid (fn.type == 0), in that case other invariants don't hold + * - nodes may be invalid (n.type == 0), in that case other invariants don't hold * - n.metric1 may be at most a small multiple of LSINFINITY, * therefore sums do not overflow * - n.oa is always non-NULL |