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Implement RA_ACCEPTED mode of route propagation.

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This commit is contained in:
Ondrej Zajicek 2012-04-15 15:07:58 +02:00
parent bf2abe2f51
commit 00a09f3c36
5 changed files with 281 additions and 160 deletions
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3
nest/route.h
View file

@ -223,7 +223,8 @@ typedef struct rte {
/* Types of route announcement, also used as flags */
#define RA_OPTIMAL 1 /* Announcement of optimal route change */
#define RA_ANY 2 /* Announcement of any route change */
#define RA_ACCEPTED 2 /* Announcement of first accepted route */
#define RA_ANY 3 /* Announcement of any route change */
struct config;

402
nest/rt-table.c
View file

@ -182,86 +182,73 @@ rte_trace_out(unsigned int flag, struct proto *p, rte *e, char *msg)
rte_trace(p, e, '<', msg);
}
static inline void
do_rte_announce(struct announce_hook *ah, int type UNUSED, net *net, rte *new, rte *old, ea_list *tmpa, int refeed)
static rte *
export_filter(struct announce_hook *ah, rte *rt0, rte **rt_free, ea_list **tmpa, int silent)
{
struct proto *p = ah->proto;
struct filter *filter = ah->out_filter;
struct proto_stats *stats = ah->stats;
ea_list *tmpb = NULL;
rte *rt;
int v;
rte *new0 = new;
rte *old0 = old;
int ok;
rt = rt0;
*rt_free = NULL;
if (new)
/* If called does not care for eattrs, we prepare one internally */
if (!tmpa)
{
stats->exp_updates_received++;
struct proto *src = rt->attrs->proto;
tmpb = src->make_tmp_attrs ? src->make_tmp_attrs(rt, rte_update_pool) : NULL;
tmpa = &tmpb;
}
char *drop_reason = NULL;
if ((ok = p->import_control ? p->import_control(p, &new, &tmpa, rte_update_pool) : 0) < 0)
v = p->import_control ? p->import_control(p, &rt, tmpa, rte_update_pool) : 0;
if (v < 0)
{
if (silent)
goto reject;
stats->exp_updates_rejected++;
drop_reason = "rejected by protocol";
rte_trace_out(D_FILTERS, p, rt, "rejected by protocol");
goto reject;
}
else if (ok)
rte_trace_out(D_FILTERS, p, new, "forced accept by protocol");
else if ((filter == FILTER_REJECT) ||
(filter && f_run(filter, &new, &tmpa, rte_update_pool, FF_FORCE_TMPATTR) > F_ACCEPT))
if (v > 0)
{
if (!silent)
rte_trace_out(D_FILTERS, p, rt, "forced accept by protocol");
goto accept;
}
v = filter && ((filter == FILTER_REJECT) ||
(f_run(filter, &rt, tmpa, rte_update_pool, FF_FORCE_TMPATTR) > F_ACCEPT));
if (v)
{
if (silent)
goto reject;
stats->exp_updates_filtered++;
drop_reason = "filtered out";
}
if (drop_reason)
{
rte_trace_out(D_FILTERS, p, new, drop_reason);
if (new != new0)
rte_free(new);
new = NULL;
}
}
else
stats->exp_withdraws_received++;
/*
* This is a tricky part - we don't know whether route 'old' was
* exported to protocol 'p' or was filtered by the export filter.
* We try tu run the export filter to know this to have a correct
* value in 'old' argument of rte_update (and proper filter value)
*
* FIXME - this is broken because 'configure soft' may change
* filters but keep routes. Refeed is expected to be called after
* change of the filters and with old == new, therefore we do not
* even try to run the filter on an old route, This may lead to
* 'spurious withdraws' but ensure that there are no 'missing
* withdraws'.
*
* This is not completely safe as there is a window between
* reconfiguration and the end of refeed - if a newly filtered
* route disappears during this period, proper withdraw is not
* sent (because old would be also filtered) and the route is
* not refeeded (because it disappeared before that).
*/
if (old && !refeed)
{
if (filter == FILTER_REJECT)
old = NULL;
else
{
ea_list *tmpb = p->make_tmp_attrs ? p->make_tmp_attrs(old, rte_update_pool) : NULL;
ok = p->import_control ? p->import_control(p, &old, &tmpb, rte_update_pool) : 0;
if (ok < 0 || (!ok && filter && f_run(filter, &old, &tmpb, rte_update_pool, FF_FORCE_TMPATTR) > F_ACCEPT))
{
if (old != old0)
rte_free(old);
old = NULL;
}
}
rte_trace_out(D_FILTERS, p, rt, "filtered out");
goto reject;
}
/* FIXME - This is broken because of incorrect 'old' value (see above) */
if (!new && !old)
return;
accept:
if (rt != rt0)
*rt_free = rt;
return rt;
reject:
/* Discard temporary rte */
if (rt != rt0)
rte_free(rt);
return NULL;
}
static void
do_rt_notify(struct announce_hook *ah, net *net, rte *new, rte *old, ea_list *tmpa, int refeed)
{
struct proto *p = ah->proto;
struct proto_stats *stats = ah->stats;
if (new)
stats->exp_updates_accepted++;
@ -297,10 +284,174 @@ do_rte_announce(struct announce_hook *ah, int type UNUSED, net *net, rte *new, r
}
else
p->rt_notify(p, ah->table, net, new, old, new->attrs->eattrs);
if (new && new != new0) /* Discard temporary rte's */
rte_free(new);
if (old && old != old0)
rte_free(old);
}
static void
rt_notify_basic(struct announce_hook *ah, net *net, rte *new, rte *old, ea_list *tmpa, int refeed)
{
// struct proto *p = ah->proto;
struct proto_stats *stats = ah->stats;
rte *new_free = NULL;
rte *old_free = NULL;
if (new)
stats->exp_updates_received++;
else
stats->exp_withdraws_received++;
/*
* This is a tricky part - we don't know whether route 'old' was
* exported to protocol 'p' or was filtered by the export filter.
* We try to run the export filter to know this to have a correct
* value in 'old' argument of rte_update (and proper filter value)
*
* FIXME - this is broken because 'configure soft' may change
* filters but keep routes. Refeed is expected to be called after
* change of the filters and with old == new, therefore we do not
* even try to run the filter on an old route, This may lead to
* 'spurious withdraws' but ensure that there are no 'missing
* withdraws'.
*
* This is not completely safe as there is a window between
* reconfiguration and the end of refeed - if a newly filtered
* route disappears during this period, proper withdraw is not
* sent (because old would be also filtered) and the route is
* not refeeded (because it disappeared before that).
*/
if (new)
new = export_filter(ah, new, &new_free, &tmpa, 0);
if (old && !refeed)
old = export_filter(ah, old, &old_free, NULL, 1);
/* FIXME - This is broken because of incorrect 'old' value (see above) */
if (!new && !old)
return;
do_rt_notify(ah, net, new, old, tmpa, refeed);
/* Discard temporary rte's */
if (new_free)
rte_free(new_free);
if (old_free)
rte_free(old_free);
}
static void
rt_notify_accepted(struct announce_hook *ah, net *net, rte *new_changed, rte *old_changed, rte *before_old,
ea_list *tmpa, int feed)
{
// struct proto *p = ah->proto;
struct proto_stats *stats = ah->stats;
rte *new_best = NULL;
rte *old_best = NULL;
rte *new_free = NULL;
rte *old_free = NULL;
rte *r;
/* Used to track whethe we met old_changed position. If it is NULL
it was the first and met it implicitly before current best route. */
int old_meet = (old_changed && !before_old) ? 1 : 0;
if (new_changed)
stats->exp_updates_received++;
else
stats->exp_withdraws_received++;
/* First, find the new_best route - first accepted by filters */
for (r=net->routes; r; r=r->next)
{
if (new_best = export_filter(ah, r, &new_free, &tmpa, 0))
break;
/* Note if we walked around the position of old_changed route */
if (r == before_old)
old_meet = 1;
}
/*
* Second, handle the feed case. That means we do not care for
* old_best. It is NULL for feed, and the new_best for refeed.
* For refeed, there is a hack similar to one in rt_notify_basic()
* to ensure withdraws in case of changed filters
*/
if (feed)
{
if (feed == 2) /* refeed */
old_best = new_best ? new_best : net->routes;
else
old_best = NULL;
if (!new_best && !old_best)
return;
goto found;
}
/*
* Now, we find the old_best route. Generally, it is the same as the
* new_best, unless new_best is the same as new_changed or
* old_changed is accepted before new_best.
*
* There are four cases:
*
* - We would find and accept old_changed before new_best, therefore
* old_changed is old_best. In remaining cases we suppose this
* is not true.
*
* - We found no new_best, therefore there is also no old_best and
* we ignore this withdraw.
*
* - We found new_best different than new_changed, therefore
* old_best is the same as new_best and we ignore this update.
*
* - We found new_best the same as new_changed, therefore it cannot
* be old_best and we have to continue search for old_best.
*/
/* First case */
if (old_meet)
if (old_best = export_filter(ah, old_changed, &old_free, NULL, 1))
goto found;
/* Second case */
if (!new_best)
return;
/* Third case, we use r insead of new_best, because export_filter() could change it */
if (r != new_changed)
{
if (new_free)
rte_free(new_free);
return;
}
/* Fourth case */
for (; r; r=r->next)
{
if (old_best = export_filter(ah, r, &old_free, NULL, 1))
goto found;
if (r == before_old)
if (old_best = export_filter(ah, old_changed, &old_free, NULL, 1))
goto found;
}
/* Implicitly, old_best is NULL and new_best is non-NULL */
found:
do_rt_notify(ah, net, new_best, old_best, tmpa, (feed == 2));
/* Discard temporary rte's */
if (new_free)
rte_free(new_free);
if (old_free)
rte_free(old_free);
}
/**
@ -333,7 +484,7 @@ do_rte_announce(struct announce_hook *ah, int type UNUSED, net *net, rte *new, r
* the protocol gets called.
*/
static void
rte_announce(rtable *tab, unsigned type, net *net, rte *new, rte *old, ea_list *tmpa)
rte_announce(rtable *tab, unsigned type, net *net, rte *new, rte *old, rte *before_old, ea_list *tmpa)
{
struct announce_hook *a;
@ -352,11 +503,13 @@ rte_announce(rtable *tab, unsigned type, net *net, rte *new, rte *old, ea_list *
{
ASSERT(a->proto->core_state == FS_HAPPY || a->proto->core_state == FS_FEEDING);
if (a->proto->accept_ra_types == type)
do_rte_announce(a, type, net, new, old, tmpa, 0);
if (type == RA_ACCEPTED)
rt_notify_accepted(a, net, new, old, before_old, tmpa, 0);
else
rt_notify_basic(a, net, new, old, tmpa, 0);
}
}
static inline int
rte_validate(rte *e)
{
@ -419,9 +572,10 @@ rte_recalculate(struct announce_hook *ah, net *net, rte *new, ea_list *tmpa, str
struct proto *p = ah->proto;
struct rtable *table = ah->table;
struct proto_stats *stats = ah->stats;
rte *before_old = NULL;
rte *old_best = net->routes;
rte *old = NULL;
rte **k, *r, *s;
rte **k;
k = &net->routes; /* Find and remove original route from the same protocol */
while (old = *k)
@ -466,8 +620,12 @@ rte_recalculate(struct announce_hook *ah, net *net, rte *new, ea_list *tmpa, str
break;
}
k = &old->next;
before_old = old;
}
if (!old)
before_old = NULL;
if (!old && !new)
{
stats->imp_withdraws_ignored++;
@ -484,82 +642,21 @@ rte_recalculate(struct announce_hook *ah, net *net, rte *new, ea_list *tmpa, str
if (old)
stats->imp_routes--;
rte_announce(table, RA_ANY, net, new, old, tmpa);
if (src->rte_recalculate && src->rte_recalculate(table, net, new, old, old_best))
goto do_recalculate;
if (new && rte_better(new, old_best))
{
/* The first case - the new route is cleary optimal, we link it
at the first position and announce it */
rte_trace_in(D_ROUTES, p, new, "added [best]");
rte_announce(table, RA_OPTIMAL, net, new, old_best, tmpa);
new->next = net->routes;
net->routes = new;
}
else if (old == old_best)
{
/* The second case - the old best route disappeared, we add the
new route (if we have any) to the list (we don't care about
position) and then we elect the new optimal route and relink
that route at the first position and announce it. New optimal
route might be NULL if there is no more routes */
do_recalculate:
/* Add the new route to the list */
if (new)
{
rte_trace_in(D_ROUTES, p, new, "added");
new->next = net->routes;
net->routes = new;
}
/* Find new optimal route */
r = NULL;
for (s=net->routes; s; s=s->next)
if (rte_better(s, r))
r = s;
/* Announce optimal route */
rte_announce(table, RA_OPTIMAL, net, r, old_best, tmpa);
/* And relink it (if there is any) */
if (r)
{
k = &net->routes;
while (s = *k)
{
if (s == r)
{
*k = r->next;
for (k=&net->routes; *k; k=&(*k)->next)
if (rte_better(new, *k))
break;
}
k = &s->next;
}
r->next = net->routes;
net->routes = r;
}
else if (table->gc_counter++ >= table->config->gc_max_ops &&
table->gc_time + table->config->gc_min_time <= now)
rt_schedule_gc(table);
}
else if (new)
{
/* The third case - the new route is not better than the old
best route (therefore old_best != NULL) and the old best
route was not removed (therefore old_best == net->routes).
We just link the new route after the old best route. */
ASSERT(net->routes != NULL);
new->next = net->routes->next;
net->routes->next = new;
rte_trace_in(D_ROUTES, p, new, "added");
new->lastmod = now;
new->next = *k;
*k = new;
rte_trace_in(D_ROUTES, p, new, net->routes == new ? "added [best]" : "added");
}
/* Log the route removal */
if (!new && old && (p->debug & D_ROUTES))
if (!new && (p->debug & D_ROUTES))
{
if (old != old_best)
rte_trace_in(D_ROUTES, p, old, "removed");
@ -569,6 +666,15 @@ rte_recalculate(struct announce_hook *ah, net *net, rte *new, ea_list *tmpa, str
rte_trace_in(D_ROUTES, p, old, "removed [sole]");
}
rte_announce(table, RA_ANY, net, new, old, NULL, tmpa);
rte_announce(table, RA_OPTIMAL, net, net->routes, old_best, NULL, tmpa);
rte_announce(table, RA_ACCEPTED, net, new, old, before_old, tmpa);
if (!net->routes &&
(table->gc_counter++ >= table->config->gc_max_ops) &&
(table->gc_time + table->config->gc_min_time <= now))
rt_schedule_gc(table);
if (old)
{
if (p->rte_remove)
@ -577,7 +683,6 @@ rte_recalculate(struct announce_hook *ah, net *net, rte *new, ea_list *tmpa, str
}
if (new)
{
new->lastmod = now;
if (p->rte_insert)
p->rte_insert(net, new);
}
@ -709,7 +814,7 @@ rte_announce_i(rtable *tab, unsigned type, net *n, rte *new, rte *old)
rte_update_lock();
src = new->attrs->proto;
tmpa = src->make_tmp_attrs ? src->make_tmp_attrs(new, rte_update_pool) : NULL;
rte_announce(tab, type, n, new, old, tmpa);
rte_announce(tab, type, n, new, old, NULL, tmpa);
rte_update_unlock();
}
@ -1259,12 +1364,15 @@ rt_commit(struct config *new, struct config *old)
static inline void
do_feed_baby(struct proto *p, int type, struct announce_hook *h, net *n, rte *e)
{
struct proto *q = e->attrs->proto;
struct proto *src = e->attrs->proto;
ea_list *tmpa;
rte_update_lock();
tmpa = q->make_tmp_attrs ? q->make_tmp_attrs(e, rte_update_pool) : NULL;
do_rte_announce(h, type, n, e, p->refeeding ? e : NULL, tmpa, p->refeeding);
tmpa = src->make_tmp_attrs ? src->make_tmp_attrs(e, rte_update_pool) : NULL;
if (type == RA_ACCEPTED)
rt_notify_accepted(h, n, e, NULL, NULL, tmpa, p->refeeding ? 2 : 1);
else
rt_notify_basic(h, n, e, p->refeeding ? e : NULL, tmpa, p->refeeding);
rte_update_unlock();
}

7
proto/bgp/bgp.c
View file

@ -909,7 +909,7 @@ bgp_init(struct proto_config *C)
struct proto *P = proto_new(C, sizeof(struct bgp_proto));
struct bgp_proto *p = (struct bgp_proto *) P;
P->accept_ra_types = RA_OPTIMAL;
P->accept_ra_types = c->secondary ? RA_ACCEPTED : RA_OPTIMAL;
P->rt_notify = bgp_rt_notify;
P->rte_better = bgp_rte_better;
P->import_control = bgp_import_control;
@ -955,12 +955,14 @@ bgp_check_config(struct bgp_config *c)
if (internal && c->rs_client)
cf_error("Only external neighbor can be RS client");
/*
if (c->multihop && (c->gw_mode == GW_DIRECT))
cf_error("Multihop BGP cannot use direct gateway mode");
if (c->multihop && (ipa_has_link_scope(c->remote_ip) ||
ipa_has_link_scope(c->source_addr)))
cf_error("Multihop BGP cannot be used with link-local addresses");
*/
/* Different default based on rs_client */
if (!c->missing_lladdr)
@ -968,7 +970,8 @@ bgp_check_config(struct bgp_config *c)
/* Different default for gw_mode */
if (!c->gw_mode)
c->gw_mode = (c->multihop || internal) ? GW_RECURSIVE : GW_DIRECT;
// c->gw_mode = (c->multihop || internal) ? GW_RECURSIVE : GW_DIRECT;
c->gw_mode = GW_DIRECT;
}
static int

1
proto/bgp/bgp.h
View file

@ -43,6 +43,7 @@ struct bgp_config {
u32 route_limit; /* Number of routes that may be imported, 0 means disable limit */
int passive; /* Do not initiate outgoing connection */
int interpret_communities; /* Hardwired handling of well-known communities */
int secondary; /* Accept also non-best routes (i.e. RA_ACCEPTED) */
unsigned connect_retry_time;
unsigned hold_time, initial_hold_time;
unsigned keepalive_time;

10
proto/bgp/config.Y
View file

@ -25,7 +25,8 @@ CF_KEYWORDS(BGP, LOCAL, NEIGHBOR, AS, HOLD, TIME, CONNECT, RETRY,
CLUSTER, ID, AS4, ADVERTISE, IPV4, CAPABILITIES, LIMIT, PASSIVE,
PREFER, OLDER, MISSING, LLADDR, DROP, IGNORE, ROUTE, REFRESH,
INTERPRET, COMMUNITIES, BGP_ORIGINATOR_ID, BGP_CLUSTER_LIST, IGP,
TABLE, GATEWAY, DIRECT, RECURSIVE, MED, TTL, SECURITY, DETERMINISTIC)
TABLE, GATEWAY, DIRECT, RECURSIVE, MED, TTL, SECURITY, DETERMINISTIC,
SECONDARY)
CF_GRAMMAR
@ -73,19 +74,25 @@ bgp_proto:
| bgp_proto STARTUP HOLD TIME expr ';' { BGP_CFG->initial_hold_time = $5; }
| bgp_proto CONNECT RETRY TIME expr ';' { BGP_CFG->connect_retry_time = $5; }
| bgp_proto KEEPALIVE TIME expr ';' { BGP_CFG->keepalive_time = $4; }
/*
| bgp_proto MULTIHOP ';' { BGP_CFG->multihop = 64; }
| bgp_proto MULTIHOP expr ';' { BGP_CFG->multihop = $3; if (($3<1) || ($3>255)) cf_error("Multihop must be in range 1-255"); }
*/
| bgp_proto NEXT HOP SELF ';' { BGP_CFG->next_hop_self = 1; }
| bgp_proto MISSING LLADDR SELF ';' { BGP_CFG->missing_lladdr = MLL_SELF; }
| bgp_proto MISSING LLADDR DROP ';' { BGP_CFG->missing_lladdr = MLL_DROP; }
| bgp_proto MISSING LLADDR IGNORE ';' { BGP_CFG->missing_lladdr = MLL_IGNORE; }
/*
| bgp_proto GATEWAY DIRECT ';' { BGP_CFG->gw_mode = GW_DIRECT; }
| bgp_proto GATEWAY RECURSIVE ';' { BGP_CFG->gw_mode = GW_RECURSIVE; }
*/
| bgp_proto PATH METRIC bool ';' { BGP_CFG->compare_path_lengths = $4; }
| bgp_proto MED METRIC bool ';' { BGP_CFG->med_metric = $4; }
| bgp_proto IGP METRIC bool ';' { BGP_CFG->igp_metric = $4; }
| bgp_proto PREFER OLDER bool ';' { BGP_CFG->prefer_older = $4; }
/*
| bgp_proto DETERMINISTIC MED bool ';' { BGP_CFG->deterministic_med = $4; }
*/
| bgp_proto DEFAULT BGP_MED expr ';' { BGP_CFG->default_med = $4; }
| bgp_proto DEFAULT BGP_LOCAL_PREF expr ';' { BGP_CFG->default_local_pref = $4; }
| bgp_proto SOURCE ADDRESS ipa ';' { BGP_CFG->source_addr = $4; }
@ -101,6 +108,7 @@ bgp_proto:
| bgp_proto ROUTE LIMIT expr ';' { BGP_CFG->route_limit = $4; }
| bgp_proto PASSIVE bool ';' { BGP_CFG->passive = $3; }
| bgp_proto INTERPRET COMMUNITIES bool ';' { BGP_CFG->interpret_communities = $4; }
| bgp_proto SECONDARY bool ';' { BGP_CFG->secondary = $3; }
| bgp_proto IGP TABLE rtable ';' { BGP_CFG->igp_table = $4; }
| bgp_proto TTL SECURITY bool ';' { BGP_CFG->ttl_security = $4; }
;