OSPF: Fix handling of external routes on graceful restart

We need to flush learned external LSAs a bit later than other LSAs (after
first feed after end of the graceful restart) to avoid flap of external
routes.
This commit is contained in:
Ondrej Zajicek (work) 2019-07-09 03:31:54 +02:00
parent 05e3933c06
commit 85840d4c03
6 changed files with 75 additions and 35 deletions

View file

@ -880,7 +880,6 @@ ospf_iface_reconfigure(struct ospf_iface *ifa, struct ospf_iface_patt *new)
ifname, ifa->priority, new->priority);
ifa->priority = new->priority;
ospf_iface_sm(ifa, ISM_NEICH);
ospf_notify_link_lsa(ifa);
}

View file

@ -246,18 +246,33 @@ void
ospf_stop_gr_recovery(struct ospf_proto *p)
{
p->gr_recovery = 0;
p->gr_cleanup = 1;
p->gr_timeout = 0;
channel_graceful_restart_unlock(p->p.main_channel);
/* Reorigination of router/network LSAs is already scheduled */
ospf_mark_lsadb(p);
/*
* NOTE: We should move channel_graceful_restart_unlock() to the end of
* ospf_disp() in order to have local LSA reorigination / LSAdb cleanup /
* routing table recomputation before official end of GR. It does not matter
* when we are single-threaded.
*/
/* Rest is done in ospf_cleanup_gr_recovery() */
}
static void
ospf_cleanup_gr_recovery(struct ospf_proto *p)
{
struct top_hash_entry *en;
/* Flush dirty LSAa except external ones, these will be handled by feed */
WALK_SLIST(en, p->lsal)
if (en->gr_dirty)
{
if ((en->lsa_type == LSA_T_EXT) || (en->lsa_type == LSA_T_NSSA))
en->mode = LSA_M_EXPORT;
else
ospf_flush_lsa(p, en);
}
/* End graceful restart on channel, will also schedule feed */
channel_graceful_restart_unlock(p->p.main_channel);
p->gr_cleanup = 0;
}
static int
@ -361,6 +376,8 @@ ospf_init(struct proto_config *CF)
P->ifa_notify = cf->ospf2 ? ospf_ifa_notify2 : ospf_ifa_notify3;
P->preexport = ospf_preexport;
P->reload_routes = ospf_reload_routes;
P->feed_begin = ospf_feed_begin;
P->feed_end = ospf_feed_end;
P->make_tmp_attrs = ospf_make_tmp_attrs;
P->store_tmp_attrs = ospf_store_tmp_attrs;
P->rte_better = ospf_rte_better;
@ -436,6 +453,7 @@ ospf_disp(timer * timer)
{
struct ospf_proto *p = timer->data;
/* Check for end of graceful restart */
if (p->gr_recovery)
ospf_update_gr_recovery(p);
@ -448,6 +466,10 @@ ospf_disp(timer * timer)
/* Calculate routing table */
if (p->calcrt)
ospf_rt_spf(p);
/* Cleanup after graceful restart */
if (p->gr_cleanup)
ospf_cleanup_gr_recovery(p);
}

View file

@ -223,7 +223,8 @@ struct ospf_proto
int areano; /* Number of area I belong to */
int padj; /* Number of neighbors in Exchange or Loading state */
int gr_count; /* Number of neighbors in graceful restart state */
int gr_recovery; /* Graceful restart recovery is active */
u8 gr_recovery; /* Graceful restart recovery is active */
u8 gr_cleanup; /* GR cleanup scheduled */
btime gr_timeout; /* The end time of grace restart recovery */
struct fib rtf; /* Routing table */
struct idm idm; /* OSPFv3 LSA ID map */

View file

@ -1640,7 +1640,7 @@ ospf_rt_reset(struct ospf_proto *p)
en->lb = IPA_NONE;
if (en->mode == LSA_M_RTCALC)
en->mode = LSA_M_STALE;
en->mode = LSA_M_RTCALC_STALE;
}
WALK_LIST(oa, p->area_list)
@ -2117,7 +2117,7 @@ again2:
/* Cleanup stale LSAs */
WALK_SLIST(en, p->lsal)
if (en->mode == LSA_M_STALE)
if (en->mode == LSA_M_RTCALC_STALE)
ospf_flush_lsa(p, en);
}

View file

@ -71,6 +71,7 @@ ospf_install_lsa(struct ospf_proto *p, struct ospf_lsa_header *lsa, u32 type, u3
en->lsa = *lsa;
en->init_age = en->lsa.age;
en->inst_time = current_time();
en->gr_dirty = p->gr_recovery && (lsa->rt == p->router_id);
/*
* We do not set en->mode. It is either default LSA_M_BASIC, or in a special
@ -246,7 +247,7 @@ ospf_do_originate_lsa(struct ospf_proto *p, struct top_hash_entry *en, void *lsa
en->lsa.age = 0;
en->init_age = 0;
en->inst_time = current_time();
en->dirty = 0;
en->gr_dirty = 0;
lsa_generate_checksum(&en->lsa, en->lsa_body);
OSPF_TRACE(D_EVENTS, "Originating LSA: Type: %04x, Id: %R, Rt: %R, Seq: %08x",
@ -329,7 +330,7 @@ ospf_originate_lsa(struct ospf_proto *p, struct ospf_new_lsa *lsa)
(lsa_length == en->lsa.length) &&
!memcmp(lsa_body, en->lsa_body, lsa_blen) &&
(!ospf_is_v2(p) || (lsa->opts == lsa_get_options(&en->lsa))) &&
!en->dirty)
!en->gr_dirty)
goto drop;
lsa_body = lsab_flush(p);
@ -422,6 +423,7 @@ void
ospf_flush_lsa(struct ospf_proto *p, struct top_hash_entry *en)
{
en->nf = NULL;
en->gr_dirty = 0;
if (en->next_lsa_body)
{
@ -520,12 +522,6 @@ ospf_update_lsadb(struct ospf_proto *p)
continue;
}
if (en->dirty)
{
ospf_flush_lsa(p, en);
continue;
}
if ((en->lsa.rt == p->router_id) && (real_age >= LSREFRESHTIME))
{
ospf_refresh_lsa(p, en);
@ -543,14 +539,27 @@ ospf_update_lsadb(struct ospf_proto *p)
}
void
ospf_mark_lsadb(struct ospf_proto *p)
ospf_feed_begin(struct channel *C, int initial UNUSED)
{
struct ospf_proto *p = (struct ospf_proto *) C->proto;
struct top_hash_entry *en;
/* Mark all local LSAs as dirty */
/* Mark all external LSAs as stale */
WALK_SLIST(en, p->lsal)
if (en->lsa.rt == p->router_id)
en->dirty = 1;
if (en->mode == LSA_M_EXPORT)
en->mode = LSA_M_EXPORT_STALE;
}
void
ospf_feed_end(struct channel *C)
{
struct ospf_proto *p = (struct ospf_proto *) C->proto;
struct top_hash_entry *en;
/* Flush stale LSAs */
WALK_SLIST(en, p->lsal)
if (en->mode == LSA_M_EXPORT_STALE)
ospf_flush_lsa(p, en);
}
static u32

View file

@ -33,7 +33,7 @@ struct top_hash_entry
u32 lb_id; /* Interface ID of link back iface (for bcast or NBMA networks) */
u32 dist; /* Distance from the root */
int ret_count; /* Number of retransmission lists referencing the entry */
u8 dirty; /* Will be flushed during next LSAdb update unless reoriginated*/
u8 gr_dirty; /* Local LSA received during GR, will be removed unless reoriginated */
u8 color;
#define OUTSPF 0
#define CANDIDATE 1
@ -115,10 +115,11 @@ struct top_hash_entry
*/
#define LSA_M_BASIC 0
#define LSA_M_EXPORT 1
#define LSA_M_RTCALC 2
#define LSA_M_STALE 3
#define LSA_M_BASIC 0
#define LSA_M_EXPORT 1
#define LSA_M_RTCALC 2
#define LSA_M_EXPORT_STALE 3
#define LSA_M_RTCALC_STALE 4
/*
* LSA entry modes:
@ -128,9 +129,13 @@ struct top_hash_entry
* routing table calculation is scheduled. This is also the mode used for LSAs
* received from neighbors. Example: Router-LSAs, Network-LSAs.
*
* LSA_M_EXPORT - like LSA_M_BASIC, but the routing table calculation does not
* depend on the LSA. Therefore, the calculation is not scheduled when the LSA
* is changed. Example: AS-external-LSAs for exported routes.
* LSA_M_EXPORT - The LSA is originated using ospf_originate_lsa() as a
* consequence of route export to the OSPF instance. It has to be reoriginated
* during each channel feed, otherwise it is flushed automatically at the end of
* the feed. May be originated and flushed asynchronously. Also, routing table
* calculation does not depend on the LSA. Therefore, the routing table
* calculation is not scheduled when the LSA is changed. Example:
* AS-external-LSAs for exported routes.
*
* LSA_M_RTCALC - The LSA has to be requested using ospf_originate_lsa() during
* each routing table calculation, otherwise it is flushed automatically at the
@ -138,8 +143,11 @@ struct top_hash_entry
* source for it. Therefore, the calculation is not scheduled when the LSA is
* changed. Example: Summary-LSAs.
*
* LSA_M_STALE - Temporary state for LSA_M_RTCALC that is not requested during
* the current routing table calculation.
* LSA_M_EXPORT_STALE - Temporary state for LSA_M_EXPORT that is not requested
* during current external route feed.
*
* LSA_M_RTCALC_STALE - Temporary state for LSA_M_RTCALC that is not requested
* during current routing table calculation.
*
*
* Note that we do not schedule the routing table calculation when the age of
@ -181,7 +189,8 @@ struct top_hash_entry * ospf_originate_lsa(struct ospf_proto *p, struct ospf_new
void ospf_advance_lsa(struct ospf_proto *p, struct top_hash_entry *en, struct ospf_lsa_header *lsa, u32 type, u32 domain, void *body);
void ospf_flush_lsa(struct ospf_proto *p, struct top_hash_entry *en);
void ospf_update_lsadb(struct ospf_proto *p);
void ospf_mark_lsadb(struct ospf_proto *p);
void ospf_feed_begin(struct channel *C, int initial);
void ospf_feed_end(struct channel *C);
static inline void ospf_flush2_lsa(struct ospf_proto *p, struct top_hash_entry **en)
{ if (*en) { ospf_flush_lsa(p, *en); *en = NULL; } }