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/*
* BIRD -- OSPF
*
* (c) 2000--2004 Ondrej Filip <feela@network.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*
*/
#ifndef _BIRD_OSPF_RT_H_
#define _BIRD_OSPF_RT_H_
#define ORT_UNDEF -1
#define ORT_ROUTER 1
#define ORT_NET 0
typedef struct orta
{
u8 type; /* RTS_OSPF_* */
u8 nhs_reuse; /* Whether nhs nodes can be reused during merging */
u32 options;
/*
* For ORT_ROUTER routes, options field are router-LSA style
* options, with V,E,B bits. In OSPFv2, ASBRs from another areas
* (that we know from rt-summary-lsa) have just ORTA_ASBR in
* options, their real options are unknown.
*/
#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.
*/
#define ORTA_PREF 0x80000000
#define ORTA_NSSA 0x40000000
#define ORTA_PROP 0x20000000
u32 metric1;
u32 metric2;
u32 tag;
u32 rid; /* Router ID of real advertising router */
struct ospf_area *oa;
struct ospf_area *voa; /* Used when route is replaced in ospf_rt_sum_tr(),
NULL otherwise */
struct mpnh *nhs; /* Next hops computed during SPF */
struct top_hash_entry *en; /* LSA responsible for this orta */
}
orta;
typedef struct ort
{
/*
* We use fn.x0 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 fn.x1 to note whether the external route was originated
* from the route export (in ospf_rt_notify()) or from the NSSA
* route translation (in 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 wasn 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;
}
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)
* enforced by SPF calculation for final nodes (color == INSPF):
* - only router, network and AS-external LSAs
* - lsa.age < LSA_MAXAGE
* - dist < LSINFINITY (or 2*LSINFINITY for ext-LSAs)
* - nhs is non-NULL unless the node is oa->rt (calculating router itself)
* - 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
* - n.metric1 may be at most a small multiple of LSINFINITY,
* therefore sums do not overflow
* - n.oa is always non-NULL
* - n.nhs is always non-NULL unless it is configured stubnet
* - n.en is non-NULL for external routes, NULL for intra/inter area routes.
* - oa->rtr does not contain calculating router itself
*
* There are four types of nexthops in nhs fields:
* - gateway nexthops (non-NULL iface, gw != IPA_NONE)
* - device nexthops (non-NULL iface, gw == IPA_NONE)
* - dummy vlink nexthops (NULL iface, gw == IPA_NONE)
* - configured stubnets (nhs is NULL, only RTS_OSPF orta nodes in po->rtf)
*
* Dummy vlink nexthops and configured stubnets cannot be mixed with
* regular ones, nhs field contains either list of gateway+device nodes,
* one vlink node, or NULL for configured stubnet.
*
* Dummy vlink nexthops can appear in both network (rtf) and backbone area router
* (rtr) tables for regular and inter-area routes, but only if areano > 1. They are
* replaced in ospf_rt_sum_tr() and removed in ospf_rt_abr1(), therefore cannot
* appear in ASBR pre-selection and external routes processing.
*/
void ospf_rt_spf(struct proto_ospf *po);
void ospf_rt_initort(struct fib_node *fn);
#endif /* _BIRD_OSPF_RT_H_ */
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