Annotation of embedaddon/bird/proto/ospf/topology.h, revision 1.1.1.1
1.1 misho 1: /*
2: * BIRD -- OSPF
3: *
4: * (c) 1999--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_TOPOLOGY_H_
12: #define _BIRD_OSPF_TOPOLOGY_H_
13:
14: struct top_hash_entry
15: { /* Index for fast mapping (type,rtrid,LSid)->vertex */
16: snode n;
17: node cn; /* For adding into list of candidates
18: in intra-area routing table calculation */
19: struct top_hash_entry *next; /* Next in hash chain */
20: struct ospf_lsa_header lsa;
21: u16 lsa_type; /* lsa.type processed and converted to common values (LSA_T_*) */
22: u16 init_age; /* Initial value for lsa.age during inst_time */
23: u32 domain; /* Area ID for area-wide LSAs, Iface ID for link-wide LSAs */
24: // struct ospf_area *oa;
25: void *lsa_body; /* May be NULL if LSA was flushed but hash entry was kept */
26: void *next_lsa_body; /* For postponed LSA origination */
27: u16 next_lsa_blen; /* For postponed LSA origination */
28: u16 next_lsa_opts; /* For postponed LSA origination */
29: bird_clock_t inst_time; /* Time of installation into DB */
30: struct ort *nf; /* Reference fibnode for sum and ext LSAs, NULL for otherwise */
31: struct mpnh *nhs; /* Computed nexthops - valid only in ospf_rt_spf() */
32: ip_addr lb; /* In OSPFv2, link back address. In OSPFv3, any global address in the area useful for vlinks */
33: u32 lb_id; /* Interface ID of link back iface (for bcast or NBMA networks) */
34: u32 dist; /* Distance from the root */
35: int ret_count; /* Number of retransmission lists referencing the entry */
36: u8 color;
37: #define OUTSPF 0
38: #define CANDIDATE 1
39: #define INSPF 2
40: u8 mode; /* LSA generated during RT calculation (LSA_RTCALC or LSA_STALE)*/
41: u8 nhs_reuse; /* Whether nhs nodes can be reused during merging.
42: See a note in rt.c:add_cand() */
43: };
44:
45:
46: /* Prevents ospf_hash_find() to ignore the entry, for p->lsrqh and p->lsrth */
47: #define LSA_BODY_DUMMY ((void *) 1)
48:
49: /*
50: * LSA entry life cycle
51: *
52: * LSA entries are created by ospf_originate_lsa() (for locally originated LSAs)
53: * or ospf_install_lsa() (for LSAs received from neighbors). A regular (like
54: * newly originated) LSA entry has defined lsa_body nad lsa.age < %LSA_MAXAGE.
55: * When the LSA is requested to be flushed by ospf_flush_lsa(), the lsa.age is
56: * set to %LSA_MAXAGE and flooded. Flush process is finished asynchronously,
57: * when (at least) flooding is acknowledged by neighbors. This is detected in
58: * ospf_update_lsadb(), then ospf_clear_lsa() is called to free the LSA body but
59: * the LSA entry is kept. Such LSA does not formally exist, we keep an empty
60: * entry (until regular timeout) to know inst_time and lsa.sn in the case of
61: * later reorigination. After the timeout, LSA is removed by ospf_remove_lsa().
62: *
63: * When LSA origination is requested (by ospf_originate_lsa()). but it is not
64: * possible to do that immediately (because of MinLSInterval or because the
65: * sequence number is wrapping), The new LSA is scheduled for later origination
66: * in next_lsa_* fields of the LSA entry. The later origination is handled by
67: * ospf_originate_next_lsa() called from ospf_update_lsadb(). We can see that
68: * both real origination and final flush is asynchronous to ospf_originate_lsa()
69: * and ospf_flush_lsa().
70: *
71: * LSA entry therefore could be in three basic states:
72: * R - regular (lsa.age < %LSA_MAXAGE, lsa_body != NULL)
73: * F - flushing (lsa.age == %LSA_MAXAGE, lsa_body != NULL)
74: * E - empty (lsa.age == %LSA_MAXAGE, lsa_body == NULL)
75: *
76: * And these states are doubled based on whether the next LSA is scheduled
77: * (next_lsa_body != NULL, -n suffix) or not (next_lsa_body == NULL). We also
78: * use X for a state of non-existentce. We have this basic state graph
79: * (transitions from any state to R are omitted for clarity):
80: *
81: * X --> R ---> F ---> E --> X
82: * | \ / | |
83: * | \/ | |
84: * | /\ | |
85: * | / \ | |
86: * Rn --> Fn --> En
87: *
88: * The transitions are:
89: *
90: * any state -> R - new LSA origination requested and executed
91: * R -> Rn, F -> Fn, E -> En - new LSA origination requested and postponed
92: * R -> Fn - new LSA origination requested, seqnum wrapping
93: * Rn,Fn,En -> R - postponed LSA finally originated
94: * R -> R - LSA refresh done
95: * R -> Fn - LSA refresh with seqnum wrapping
96: * R -> F, Rn -> Fn - LSA age timeout
97: * R,Rn,Fn -> F, En -> E - LSA flush requested
98: * F -> E, Fn -> En - LSA flush done (acknowledged)
99: * E -> X - LSA real age timeout (or immediate for received LSA)
100: *
101: * The 'origination requested' and 'flush requested' transitions are triggered
102: * and done by ospf_originate_lsa() and ospf_flush_lsa(), the rest is handled
103: * asynchronously by ospf_update_lsadb().
104: *
105: * The situation is significantly simpler for non-local (received) LSAs - there
106: * is no postponed origination and after flushing is done, LSAs are immediately
107: * removed, so it is just X -> R -> F -> X, or X -> F -> X (when MaxAge LSA is
108: * received).
109: *
110: * There are also some special cases related to handling of received unknown
111: * self-originated LSAs in ospf_advance_lsa():
112: * X -> F - LSA is received and immediately flushed
113: * R,Rn -> Fn - LSA with MaxSeqNo received and flushed, current LSA scheduled
114: */
115:
116:
117: #define LSA_M_BASIC 0
118: #define LSA_M_EXPORT 1
119: #define LSA_M_RTCALC 2
120: #define LSA_M_STALE 3
121:
122: /*
123: * LSA entry modes:
124: *
125: * LSA_M_BASIC - The LSA is explicitly originated using ospf_originate_lsa() and
126: * explicitly flushed using ospf_flush_lsa(). When the LSA is changed, the
127: * routing table calculation is scheduled. This is also the mode used for LSAs
128: * received from neighbors. Example: Router-LSAs, Network-LSAs.
129: *
130: * LSA_M_EXPORT - like LSA_M_BASIC, but the routing table calculation does not
131: * depend on the LSA. Therefore, the calculation is not scheduled when the LSA
132: * is changed. Example: AS-external-LSAs for exported routes.
133: *
134: * LSA_M_RTCALC - The LSA has to be requested using ospf_originate_lsa() during
135: * each routing table calculation, otherwise it is flushed automatically at the
136: * end of the calculation. The LSA is a result of the calculation and not a
137: * source for it. Therefore, the calculation is not scheduled when the LSA is
138: * changed. Example: Summary-LSAs.
139: *
140: * LSA_M_STALE - Temporary state for LSA_M_RTCALC that is not requested during
141: * the current routing table calculation.
142: *
143: *
144: * Note that we do not schedule the routing table calculation when the age of
145: * LSA_M_BASIC LSA is changed to MaxAge because of the sequence number wrapping,
146: * As it will be switched back to a regular one ASAP.
147: */
148:
149:
150: struct top_graph
151: {
152: pool *pool; /* Pool we allocate from */
153: slab *hash_slab; /* Slab for hash entries */
154: struct top_hash_entry **hash_table; /* Hashing (modelled a`la fib) */
155: uint ospf2; /* Whether it is for OSPFv2 or OSPFv3 */
156: uint hash_size;
157: uint hash_order;
158: uint hash_mask;
159: uint hash_entries;
160: uint hash_entries_min, hash_entries_max;
161: };
162:
163: struct ospf_new_lsa
164: {
165: u16 type;
166: u8 mode;
167: u32 dom;
168: u32 id;
169: u16 opts;
170: u16 length;
171: struct ospf_iface *ifa;
172: struct ort *nf;
173: };
174:
175: struct top_graph *ospf_top_new(struct ospf_proto *p, pool *pool);
176: void ospf_top_free(struct top_graph *f);
177:
178: struct top_hash_entry * ospf_install_lsa(struct ospf_proto *p, struct ospf_lsa_header *lsa, u32 type, u32 domain, void *body);
179: struct top_hash_entry * ospf_originate_lsa(struct ospf_proto *p, struct ospf_new_lsa *lsa);
180: void ospf_advance_lsa(struct ospf_proto *p, struct top_hash_entry *en, struct ospf_lsa_header *lsa, u32 type, u32 domain, void *body);
181: void ospf_flush_lsa(struct ospf_proto *p, struct top_hash_entry *en);
182: void ospf_update_lsadb(struct ospf_proto *p);
183:
184: static inline void ospf_flush2_lsa(struct ospf_proto *p, struct top_hash_entry **en)
185: { if (*en) { ospf_flush_lsa(p, *en); *en = NULL; } }
186:
187: void ospf_originate_sum_net_lsa(struct ospf_proto *p, struct ospf_area *oa, ort *nf, int metric);
188: void ospf_originate_sum_rt_lsa(struct ospf_proto *p, struct ospf_area *oa, ort *nf, int metric, u32 options);
189: void ospf_originate_ext_lsa(struct ospf_proto *p, struct ospf_area *oa, ort *nf, u8 mode, u32 metric, u32 ebit, ip_addr fwaddr, u32 tag, int pbit);
190:
191: void ospf_rt_notify(struct proto *P, rtable *tbl, net *n, rte *new, rte *old, ea_list *attrs);
192: void ospf_update_topology(struct ospf_proto *p);
193:
194: struct top_hash_entry *ospf_hash_find(struct top_graph *, u32 domain, u32 lsa, u32 rtr, u32 type);
195: struct top_hash_entry *ospf_hash_get(struct top_graph *, u32 domain, u32 lsa, u32 rtr, u32 type);
196: void ospf_hash_delete(struct top_graph *, struct top_hash_entry *);
197:
198: static inline struct top_hash_entry * ospf_hash_find_entry(struct top_graph *f, struct top_hash_entry *en)
199: { return ospf_hash_find(f, en->domain, en->lsa.id, en->lsa.rt, en->lsa_type); }
200:
201: static inline struct top_hash_entry * ospf_hash_get_entry(struct top_graph *f, struct top_hash_entry *en)
202: { return ospf_hash_get(f, en->domain, en->lsa.id, en->lsa.rt, en->lsa_type); }
203:
204: struct top_hash_entry * ospf_hash_find_rt(struct top_graph *f, u32 domain, u32 rtr);
205: struct top_hash_entry * ospf_hash_find_rt3_first(struct top_graph *f, u32 domain, u32 rtr);
206: struct top_hash_entry * ospf_hash_find_rt3_next(struct top_hash_entry *e);
207:
208: struct top_hash_entry * ospf_hash_find_net2(struct top_graph *f, u32 domain, u32 id);
209:
210: /* In OSPFv2, id is network IP prefix (lsa.id) while lsa.rt field is unknown
211: In OSPFv3, id is lsa.rt of DR while nif is neighbor iface id (lsa.id) */
212: static inline struct top_hash_entry *
213: ospf_hash_find_net(struct top_graph *f, u32 domain, u32 id, u32 nif)
214: {
215: return f->ospf2 ?
216: ospf_hash_find_net2(f, domain, id) :
217: ospf_hash_find(f, domain, nif, id, LSA_T_NET);
218: }
219:
220:
221: #endif /* _BIRD_OSPF_TOPOLOGY_H_ */
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>
![[BACK]](/icons/cvsweb/back.gif){kind=icon}
Return to topology.h CVS log ![[TXT]](/icons/cvsweb/text.gif){kind=icon}
![[DIR]](/icons/cvsweb/dir.gif){kind=icon}
Up to [ELWIX - Embedded LightWeight unIX -] / embedaddon / bird / proto / ospf