bird/nest/rt-table.c

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/*
* BIRD -- Routing Table
*
* (c) 1998--2000 Martin Mares <mj@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#include <string.h>
#define LOCAL_DEBUG
#include "nest/bird.h"
#include "nest/route.h"
#include "nest/protocol.h"
#include "nest/cli.h"
#include "nest/iface.h"
#include "lib/resource.h"
#include "lib/event.h"
#include "lib/string.h"
#include "conf/conf.h"
#include "filter/filter.h"
static slab *rte_slab;
static linpool *rte_update_pool;
#define RT_GC_MIN_TIME 5 /* FIXME: Make configurable */
#define RT_GC_MIN_COUNT 100
static pool *rt_table_pool;
static list routing_tables;
static event *rt_gc_event;
static bird_clock_t rt_last_gc;
static int rt_gc_counter;
static void
rte_init(struct fib_node *N)
{
net *n = (net *) N;
N->flags = 0;
n->routes = NULL;
}
void
rt_setup(pool *p, rtable *t, char *name)
{
bzero(t, sizeof(*t));
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fib_init(&t->fib, p, sizeof(net), 0, rte_init);
t->name = name;
init_list(&t->hooks);
}
rte *
rte_find(net *net, struct proto *p)
{
rte *e = net->routes;
while (e && e->attrs->proto != p)
e = e->next;
return e;
}
rte *
rte_get_temp(rta *a)
{
rte *e = sl_alloc(rte_slab);
e->attrs = a;
e->flags = 0;
e->pref = a->proto->preference;
return e;
}
rte *
rte_do_cow(rte *r)
{
rte *e = sl_alloc(rte_slab);
memcpy(e, r, sizeof(rte));
e->attrs = rta_clone(r->attrs);
e->flags = 0;
return e;
}
static int /* Actually better or at least as good as */
rte_better(rte *new, rte *old)
{
int (*better)(rte *, rte *);
if (!old)
return 1;
if (new->pref > old->pref)
return 1;
if (new->pref < old->pref)
return 0;
if (new->attrs->proto->proto != old->attrs->proto->proto)
{
/*
* If the user has configured protocol preferences, so that two different protocols
* have the same preference, try to break the tie by comparing addresses. Not too
* useful, but keeps the ordering of routes unambiguous.
*/
return new->attrs->proto->proto > old->attrs->proto->proto;
}
if (better = new->attrs->proto->rte_better)
return better(new, old);
return 0;
}
static inline void
do_rte_announce(struct announce_hook *a, net *net, rte *new, rte *old, ea_list *tmpa, int class)
{
struct proto *p = a->proto;
rte *new0 = new;
rte *old0 = old;
if (new)
{
int ok;
if ((class & IADDR_SCOPE_MASK) < p->min_scope ||
(ok = p->import_control ? p->import_control(p, &new, &tmpa, rte_update_pool) : 0) < 0 ||
(!ok && (p->out_filter == FILTER_REJECT ||
p->out_filter && f_run(p->out_filter, &new, &tmpa, rte_update_pool) > F_ACCEPT)
)
)
new = NULL;
}
if (old && p->out_filter)
{
/* FIXME: Do we really need to filter old routes? */
if (p->out_filter == FILTER_REJECT)
old = NULL;
else
{
ea_list *tmpb = p->make_tmp_attrs ? p->make_tmp_attrs(old, rte_update_pool) : NULL;
if (f_run(p->out_filter, &old, &tmpb, rte_update_pool) > F_ACCEPT)
old = NULL;
}
}
if (new || old)
p->rt_notify(p, net, new, old, tmpa);
if (new && new != new0) /* Discard temporary rte's */
rte_free(new);
if (old && old != old0)
rte_free(old);
}
static void
rte_announce(rtable *tab, net *net, rte *new, rte *old, ea_list *tmpa)
{
struct announce_hook *a;
int class = ipa_classify(net->n.prefix);
WALK_LIST(a, tab->hooks)
{
ASSERT(a->proto->core_state == FS_HAPPY || a->proto->core_state == FS_FEEDING);
do_rte_announce(a, net, new, old, tmpa, class);
}
}
void
rt_feed_baby(struct proto *p)
{
struct announce_hook *h;
if (!p->ahooks)
return;
debug("Announcing routes to new protocol %s\n", p->name);
for(h=p->ahooks; h; h=h->next)
{
rtable *t = h->table;
FIB_WALK(&t->fib, fn)
{
net *n = (net *) fn;
rte *e;
for(e=n->routes; e; e=e->next)
{
struct proto *q = e->attrs->proto;
ea_list *tmpa = q->make_tmp_attrs ? q->make_tmp_attrs(e, rte_update_pool) : NULL;
do_rte_announce(h, n, e, NULL, tmpa, ipa_classify(n->n.prefix));
lp_flush(rte_update_pool);
}
}
FIB_WALK_END;
}
}
static inline int
rte_validate(rte *e)
{
int c;
net *n = e->net;
ASSERT(!ipa_nonzero(ipa_and(n->n.prefix, ipa_not(ipa_mkmask(n->n.pxlen)))));
if (n->n.pxlen)
{
c = ipa_classify(n->n.prefix);
if (c < 0 || !(c & IADDR_HOST))
{
if (!ipa_nonzero(n->n.prefix) && n->n.pxlen <= 1)
return 1; /* Default route and half-default route is OK */
log(L_WARN "Ignoring bogus route %I/%d received from %I via %s",
n->n.prefix, n->n.pxlen, e->attrs->from, e->attrs->proto->name);
return 0;
}
if ((c & IADDR_SCOPE_MASK) < e->attrs->proto->min_scope)
{
log(L_WARN "Ignoring %s scope route %I/%d received from %I via %s",
ip_scope_text(c & IADDR_SCOPE_MASK),
n->n.prefix, n->n.pxlen, e->attrs->from, e->attrs->proto->name);
return 0;
}
}
return 1;
}
void
rte_free(rte *e)
{
if (e->attrs->aflags & RTAF_CACHED)
rta_free(e->attrs);
sl_free(rte_slab, e);
}
static inline void
rte_free_quick(rte *e)
{
rta_free(e->attrs);
sl_free(rte_slab, e);
}
static void
rte_recalculate(rtable *table, net *net, struct proto *p, rte *new, ea_list *tmpa)
{
rte *old_best = net->routes;
rte *old = NULL;
rte **k, *r, *s;
k = &net->routes; /* Find and remove original route from the same protocol */
while (old = *k)
{
if (old->attrs->proto == p)
{
*k = old->next;
break;
}
k = &old->next;
}
if (new && rte_better(new, old_best)) /* It's a new optimal route => announce and relink it */
{
rte_announce(table, net, new, old_best, tmpa);
new->next = net->routes;
net->routes = new;
}
else
{
if (old == old_best) /* It has _replaced_ the old optimal route */
{
r = new; /* Find new optimal route and announce it */
for(s=net->routes; s; s=s->next)
if (rte_better(s, r))
r = s;
rte_announce(table, net, r, old_best, tmpa);
if (r) /* Re-link the new optimal route */
{
k = &net->routes;
while (s = *k)
{
if (s == r)
{
*k = r->next;
break;
}
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k = &s->next;
}
r->next = net->routes;
net->routes = r;
if (!r && rt_gc_counter++ >= RT_GC_MIN_COUNT && rt_last_gc + RT_GC_MIN_TIME <= now)
ev_schedule(rt_gc_event);
}
}
if (new) /* Link in the new non-optimal route */
{
new->next = old_best->next;
old_best->next = new;
}
}
if (old)
{
if (p->rte_remove)
p->rte_remove(net, old);
rte_free_quick(old);
}
if (new)
{
new->lastmod = now;
if (p->rte_insert)
p->rte_insert(net, new);
}
}
static int rte_update_nest_cnt; /* Nesting counter to allow recursive updates */
static inline void
rte_update_lock(void)
{
rte_update_nest_cnt++;
}
static inline void
rte_update_unlock(void)
{
if (!--rte_update_nest_cnt)
lp_flush(rte_update_pool);
}
void
rte_update(rtable *table, net *net, struct proto *p, rte *new)
{
ea_list *tmpa = NULL;
rte_update_lock();
if (new)
{
if (!rte_validate(new) || p->in_filter == FILTER_REJECT)
goto drop;
if (p->make_tmp_attrs)
tmpa = p->make_tmp_attrs(new, rte_update_pool);
if (p->in_filter)
{
ea_list *old_tmpa = tmpa;
int fr = f_run(p->in_filter, &new, &tmpa, rte_update_pool);
if (fr > F_ACCEPT)
goto drop;
if (tmpa != old_tmpa && p->store_tmp_attrs)
p->store_tmp_attrs(new, tmpa);
}
if (!(new->attrs->aflags & RTAF_CACHED)) /* Need to copy attributes */
new->attrs = rta_lookup(new->attrs);
new->flags |= REF_COW;
}
rte_recalculate(table, net, p, new, tmpa);
rte_update_unlock();
return;
drop:
rte_free(new);
rte_update_unlock();
}
void
rte_discard(rtable *t, rte *old) /* Non-filtered route deletion, used during garbage collection */
{
rte_update_lock();
rte_recalculate(t, old->net, old->attrs->proto, NULL, NULL);
rte_update_unlock();
}
void
rte_dump(rte *e)
{
net *n = e->net;
if (n)
debug("%1I/%2d ", n->n.prefix, n->n.pxlen);
else
debug("??? ");
debug("KF=%02x PF=%02x pref=%d lm=%d ", n->n.flags, e->pflags, e->pref, now-e->lastmod);
rta_dump(e->attrs);
if (e->attrs->proto->proto->dump_attrs)
e->attrs->proto->proto->dump_attrs(e);
debug("\n");
}
void
rt_dump(rtable *t)
{
rte *e;
net *n;
struct announce_hook *a;
debug("Dump of routing table <%s>\n", t->name);
#ifdef DEBUGGING
fib_check(&t->fib);
#endif
FIB_WALK(&t->fib, fn)
{
n = (net *) fn;
for(e=n->routes; e; e=e->next)
rte_dump(e);
}
FIB_WALK_END;
WALK_LIST(a, t->hooks)
debug("\tAnnounces routes to protocol %s\n", a->proto->name);
debug("\n");
}
void
rt_dump_all(void)
{
rtable *t;
WALK_LIST(t, routing_tables)
rt_dump(t);
}
static int
rt_gc(void *unused)
{
rtable *t;
DBG("Entered routing table garbage collector after %d seconds and %d deletes\n", (int)(now - rt_last_gc), rt_gc_counter);
rt_prune_all();
rt_last_gc = now;
rt_gc_counter = 0;
return 0;
}
void
rt_init(void)
{
rta_init();
rt_table_pool = rp_new(&root_pool, "Routing tables");
rte_update_pool = lp_new(rt_table_pool, 4080);
rte_slab = sl_new(rt_table_pool, sizeof(rte));
rt_last_gc = now;
rt_gc_event = ev_new(rt_table_pool);
rt_gc_event->hook = rt_gc;
init_list(&routing_tables);
}
void
rt_prune(rtable *tab)
{
struct fib_iterator fit;
int rcnt = 0, rdel = 0, ncnt = 0, ndel = 0;
DBG("Pruning route table %s\n", tab->name);
FIB_ITERATE_INIT(&fit, &tab->fib);
again:
FIB_ITERATE_START(&tab->fib, &fit, f)
{
net *n = (net *) f;
rte *e;
ncnt++;
rescan:
for (e=n->routes; e; e=e->next, rcnt++)
if (e->attrs->proto->core_state != FS_HAPPY)
{
rte_discard(tab, e);
rdel++;
goto rescan;
}
if (!n->routes) /* Orphaned FIB entry? */
{
FIB_ITERATE_PUT(&fit, f);
fib_delete(&tab->fib, f);
ndel++;
goto again;
}
}
FIB_ITERATE_END(f);
DBG("Pruned %d of %d routes and %d of %d networks\n", rcnt, rdel, ncnt, ndel);
}
void
rt_prune_all(void)
{
rtable *t;
WALK_LIST(t, routing_tables)
rt_prune(t);
}
void
rt_preconfig(struct config *c)
{
struct symbol *s = cf_find_symbol("master");
struct rtable_config *r = cfg_allocz(sizeof(struct rtable_config));
cf_define_symbol(s, SYM_TABLE, r);
r->name = s->name;
init_list(&c->tables);
add_tail(&c->tables, &r->n);
c->master_rtc = r;
}
void
rt_lock_table(rtable *r)
{
r->use_count++;
}
void
rt_unlock_table(rtable *r)
{
if (!--r->use_count && r->deleted)
{
struct config *conf = r->deleted;
DBG("Deleting routing table %s\n", r->name);
rem_node(&r->n);
fib_free(&r->fib);
mb_free(r);
config_del_obstacle(conf);
}
}
void
rt_commit(struct config *new, struct config *old)
{
struct rtable_config *o, *r;
DBG("rt_commit:\n");
if (old)
{
WALK_LIST(o, old->tables)
{
rtable *ot = o->table;
if (!ot->deleted)
{
struct symbol *sym = cf_find_symbol(o->name);
if (sym && sym->class == SYM_TABLE && !new->shutdown)
{
DBG("\t%s: same\n", o->name);
r = sym->def;
r->table = ot;
ot->name = r->name;
}
else
{
DBG("\t%s: deleted\n", o->name);
ot->deleted = old;
config_add_obstacle(old);
rt_lock_table(ot);
rt_unlock_table(ot);
}
}
}
}
WALK_LIST(r, new->tables)
if (!r->table)
{
rtable *t = mb_alloc(rt_table_pool, sizeof(struct rtable));
DBG("\t%s: created\n", r->name);
rt_setup(rt_table_pool, t, r->name);
add_tail(&routing_tables, &t->n);
r->table = t;
}
DBG("\tdone\n");
}
/*
* CLI commands
*/
static void
rt_show_rte(struct cli *c, byte *ia, rte *e, struct rt_show_data *d)
{
byte via[STD_ADDRESS_P_LENGTH+32], from[STD_ADDRESS_P_LENGTH];
byte tm[TM_RELTIME_BUFFER_SIZE], info[256];
rta *a = e->attrs;
switch (a->dest)
{
case RTD_ROUTER: bsprintf(via, "via %I on %s", a->gw, a->iface->name); break;
case RTD_DEVICE: bsprintf(via, "dev %s", a->iface->name); break;
case RTD_BLACKHOLE: bsprintf(via, "blackhole"); break;
case RTD_UNREACHABLE: bsprintf(via, "unreachable"); break;
case RTD_PROHIBIT: bsprintf(via, "prohibited"); break;
default: bsprintf(via, "???");
}
tm_format_reltime(tm, e->lastmod);
if (ipa_nonzero(a->from) && !ipa_equal(a->from, a->gw))
bsprintf(from, " from %I", a->from);
else
from[0] = 0;
if (a->proto->proto->get_route_info)
a->proto->proto->get_route_info(e, info);
else
bsprintf(info, " (%d)", e->pref);
cli_printf(c, -1007, "%-18s %s [%s %s%s]%s", ia, via, a->proto->name, tm, from, info);
if (d->verbose)
{
rta_show(c, a);
if (a->proto->proto->show_route_data)
a->proto->proto->show_route_data(e);
}
}
static void
rt_show_net(struct cli *c, net *n, struct rt_show_data *d)
{
rte *e, *ee;
byte ia[STD_ADDRESS_P_LENGTH+8];
bsprintf(ia, "%I/%d", n->n.prefix, n->n.pxlen);
for(e=n->routes; e; e=e->next)
{
struct ea_list *tmpa = NULL;
ee = e;
rte_update_lock(); /* We use the update buffer for filtering */
if (d->filter == FILTER_ACCEPT || f_run(d->filter, &ee, &tmpa, rte_update_pool) <= F_ACCEPT)
{
rt_show_rte(c, ia, e, d);
ia[0] = 0;
}
if (e != ee)
rte_free(ee);
rte_update_unlock();
}
}
static void
rt_show_cont(struct cli *c)
{
struct rt_show_data *d = c->rover;
unsigned max = 1; /* FIXME: After some debugging, increase to reasonable amount */
struct fib *fib = &d->table->fib;
struct fib_iterator *it = &d->fit;
FIB_ITERATE_START(fib, it, f)
{
net *n = (net *) f;
if (!max--)
{
FIB_ITERATE_PUT(it, f);
return;
}
rt_show_net(c, n, d);
}
FIB_ITERATE_END(f);
cli_printf(c, 0, "");
c->cont = c->cleanup = NULL;
}
static void
rt_show_cleanup(struct cli *c)
{
struct rt_show_data *d = c->rover;
/* Unlink the iterator */
fit_get(&d->table->fib, &d->fit);
}
void
rt_show(struct rt_show_data *d)
{
struct rtable_config *tc;
net *n;
if (d->pxlen == 256)
{
FIB_ITERATE_INIT(&d->fit, &d->table->fib);
this_cli->cont = rt_show_cont;
this_cli->cleanup = rt_show_cleanup;
this_cli->rover = d;
}
else
{
n = fib_find(&d->table->fib, &d->prefix, d->pxlen);
if (n)
{
rt_show_net(this_cli, n, d);
cli_msg(0, "");
}
else
cli_msg(8001, "Network not in table");
}
}