bird/nest/rt-table.c
Martin Mares 08f0290a1e Changed semantics of the rt_update hook. The attribute list we pass now
contains all attributes, not just the temporary ones. This avoids having
to merge the lists inside protocols or doing searches on both of them.

Also, do filtering of routes properly. (I'd like to avoid it, but it's
needed at least in the krt protocol.)
2000-05-13 11:00:37 +00:00

858 lines
19 KiB
C

/*
* BIRD -- Routing Table
*
* (c) 1998--2000 Martin Mares <mj@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#undef 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"
#include "lib/string.h"
static slab *rte_slab;
static linpool *rte_update_pool;
static pool *rt_table_pool;
static list routing_tables;
static void rt_format_via(rte *e, byte *via);
static void
rte_init(struct fib_node *N)
{
net *n = (net *) N;
N->flags = 0;
n->routes = NULL;
}
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 void
rte_trace(struct proto *p, rte *e, int dir, char *msg)
{
byte via[STD_ADDRESS_P_LENGTH+32];
rt_format_via(e, via);
log(L_TRACE "%s %c %s %I/%d %s", p->name, dir, msg, e->net->n.prefix, e->net->n.pxlen, via);
}
static inline void
rte_trace_in(unsigned int flag, struct proto *p, rte *e, char *msg)
{
if (p->debug & flag)
rte_trace(p, e, '>', msg);
}
static inline void
rte_trace_out(unsigned int flag, struct proto *p, rte *e, char *msg)
{
if (p->debug & flag)
rte_trace(p, e, '<', msg);
}
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;
int ok;
if (new)
{
if ((class & IADDR_SCOPE_MASK) < p->min_scope)
{
rte_trace_out(D_FILTERS, p, new, "out of scope");
new = NULL;
}
else if ((ok = p->import_control ? p->import_control(p, &new, &tmpa, rte_update_pool) : 0) < 0)
{
rte_trace_out(D_FILTERS, p, new, "rejected by protocol");
new = NULL;
}
else if (ok)
rte_trace_out(D_FILTERS, p, new, "forced accept by protocol");
else if (p->out_filter == FILTER_REJECT ||
p->out_filter && f_run(p->out_filter, &new, &tmpa, rte_update_pool, FF_FORCE_TMPATTR) > F_ACCEPT)
{
rte_trace_out(D_FILTERS, p, new, "filtered out");
new = NULL;
}
}
if (old && p->out_filter)
{
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;
ok = p->import_control ? p->import_control(p, &old, &tmpb, rte_update_pool) : 0;
if (ok < 0 || (!ok && f_run(p->out_filter, &old, &tmpb, rte_update_pool, FF_FORCE_TMPATTR) > F_ACCEPT))
old = NULL;
}
}
if (p->debug & D_ROUTES)
{
if (new && old)
rte_trace_out(D_ROUTES, p, new, "replaced");
else if (new)
rte_trace_out(D_ROUTES, p, new, "added");
else if (old)
rte_trace_out(D_ROUTES, p, old, "removed");
}
if (!new && !old)
return;
if (!new)
p->rt_notify(p, net, NULL, old, NULL);
else if (tmpa)
{
while (tmpa->next)
tmpa = tmpa->next;
tmpa->next = new->attrs->eattrs;
p->rt_notify(p, net, new, old, tmpa);
tmpa->next = NULL;
}
else
p->rt_notify(p, 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
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;
DBG("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);
if (p->core_state != FS_FEEDING)
return; /* In the meantime, the protocol fell down. */
}
}
FIB_WALK_END;
}
}
static inline int
rte_validate(rte *e)
{
int c;
net *n = e->net;
if (ipa_nonzero(ipa_and(n->n.prefix, ipa_not(ipa_mkmask(n->n.pxlen)))))
{
log(L_BUG "Ignoring bogus prefix %I/%d received via %s",
n->n.prefix, n->n.pxlen, e->attrs->proto->name);
return 0;
}
if (n->n.pxlen)
{
c = ipa_classify(n->n.prefix);
if (c < 0 || !(c & IADDR_HOST))
{
if (!ipa_nonzero(n->n.prefix))
{
/* Various default routes */
#ifdef IPV6
if (n->n.pxlen == 96)
#else
if (n->n.pxlen <= 1)
#endif
return 1;
}
log(L_WARN "Ignoring bogus route %I/%d received via %s",
n->n.prefix, n->n.pxlen, 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 int
rte_same(rte *x, rte *y)
{
return
x->attrs == y->attrs &&
x->flags == y->flags &&
x->pflags == y->pflags &&
x->pref == y->pref &&
(!x->attrs->proto->rte_same || x->attrs->proto->rte_same(x, y));
}
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)
{
if (new && rte_same(old, new))
{
/* No changes, ignore the new route */
rte_trace_in(D_ROUTES, p, new, "ignored");
rte_free_quick(new);
old->lastmod = now;
return;
}
*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_trace_in(D_ROUTES, p, new, "added [best]");
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;
}
k = &s->next;
}
r->next = net->routes;
net->routes = r;
if (!r &&
table->gc_counter++ >= table->config->gc_max_ops &&
table->gc_time + table->config->gc_min_time <= now)
ev_schedule(table->gc_event);
}
}
if (new) /* Link in the new non-optimal route */
{
new->next = old_best->next;
old_best->next = new;
rte_trace_in(D_ROUTES, p, new, "added");
}
else if (old && (p->debug & D_ROUTES))
{
if (old != old_best)
rte_trace_in(D_ROUTES, p, old, "removed");
else if (net->routes)
rte_trace_in(D_ROUTES, p, old, "removed [replaced]");
else
rte_trace_in(D_ROUTES, p, old, "removed [sole]");
}
}
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))
{
rte_trace_in(D_FILTERS, p, new, "invalid");
goto drop;
}
if (p->in_filter == FILTER_REJECT)
{
rte_trace_in(D_FILTERS, p, new, "filtered out");
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, 0);
if (fr > F_ACCEPT)
{
rte_trace_in(D_FILTERS, p, new, "filtered out");
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 */
{
net *n = old->net;
struct proto *p = old->attrs->proto;
rte_update_lock();
rte_recalculate(t, n, p, 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 void
rt_gc(void *tab)
{
rtable *t = tab;
DBG("Entered routing table garbage collector for %s after %d seconds and %d deletes\n",
t->name, (int)(now - t->gc_time), t->gc_counter);
rt_prune(t);
}
void
rt_setup(pool *p, rtable *t, char *name, struct rtable_config *cf)
{
bzero(t, sizeof(*t));
fib_init(&t->fib, p, sizeof(net), 0, rte_init);
t->name = name;
t->config = cf;
init_list(&t->hooks);
if (cf)
{
t->gc_event = ev_new(p);
t->gc_event->hook = rt_gc;
t->gc_event->data = t;
}
}
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));
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);
#ifdef DEBUGGING
fib_check(&tab->fib);
#endif
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 &&
e->attrs->proto->core_state != FS_FEEDING)
{
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);
#ifdef DEBUGGING
fib_check(&tab->fib);
#endif
tab->gc_counter = 0;
tab->gc_time = now;
}
void
rt_prune_all(void)
{
rtable *t;
WALK_LIST(t, routing_tables)
rt_prune(t);
}
struct rtable_config *
rt_new_table(struct symbol *s)
{
struct rtable_config *c = cfg_allocz(sizeof(struct rtable_config));
cf_define_symbol(s, SYM_TABLE, c);
c->name = s->name;
add_tail(&new_config->tables, &c->n);
c->gc_max_ops = 100;
c->gc_min_time = 5;
return c;
}
void
rt_preconfig(struct config *c)
{
struct symbol *s = cf_find_symbol("master");
init_list(&c->tables);
c->master_rtc = rt_new_table(s);
}
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;
ot->config = r;
}
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, r);
add_tail(&routing_tables, &t->n);
r->table = t;
}
DBG("\tdone\n");
}
/*
* CLI commands
*/
static void
rt_format_via(rte *e, byte *via)
{
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, "???");
}
}
static void
rt_show_rte(struct cli *c, byte *ia, rte *e, struct rt_show_data *d, ea_list *tmpa)
{
byte via[STD_ADDRESS_P_LENGTH+32], from[STD_ADDRESS_P_LENGTH+6];
byte tm[TM_RELTIME_BUFFER_SIZE], info[256];
rta *a = e->attrs;
rt_format_via(e, 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 || d->verbose)
{
/* Need to normalize the extended attributes */
ea_list *t = tmpa;
t = ea_append(t, a->eattrs);
tmpa = alloca(ea_scan(t));
ea_merge(t, tmpa);
}
if (a->proto->proto->get_route_info)
a->proto->proto->get_route_info(e, info, tmpa);
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, tmpa);
}
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];
int ok;
bsprintf(ia, "%I/%d", n->n.prefix, n->n.pxlen);
if (n->routes)
d->net_counter++;
for(e=n->routes; e; e=e->next)
{
struct ea_list *tmpa, *old_tmpa;
struct proto *p0 = e->attrs->proto;
struct proto *p1 = d->import_protocol;
d->rt_counter++;
ee = e;
rte_update_lock(); /* We use the update buffer for filtering */
old_tmpa = tmpa = p0->make_tmp_attrs ? p0->make_tmp_attrs(e, rte_update_pool) : NULL;
ok = (d->filter == FILTER_ACCEPT || f_run(d->filter, &e, &tmpa, rte_update_pool, FF_FORCE_TMPATTR) <= F_ACCEPT);
if (ok && d->import_mode)
{
int ic = (p1->import_control ? p1->import_control(p1, &e, &tmpa, rte_update_pool) : 0);
if (ic < 0)
ok = 0;
else if (!ic && d->import_mode > 1)
{
if (p1->out_filter == FILTER_REJECT ||
p1->out_filter && f_run(p1->out_filter, &e, &tmpa, rte_update_pool, FF_FORCE_TMPATTR) > F_ACCEPT)
ok = 0;
}
}
if (ok)
{
d->show_counter++;
if (d->stats < 2)
rt_show_rte(c, ia, e, d, tmpa);
ia[0] = 0;
}
if (e != ee)
rte_free(ee);
rte_update_unlock();
if (d->primary_only)
break;
}
}
static void
rt_show_cont(struct cli *c)
{
struct rt_show_data *d = c->rover;
#ifdef DEBUGGING
unsigned max = 4;
#else
unsigned max = 64;
#endif
struct fib *fib = &d->table->fib;
struct fib_iterator *it = &d->fit;
FIB_ITERATE_START(fib, it, f)
{
net *n = (net *) f;
if (d->running_on_config && d->running_on_config != config)
{
cli_printf(c, 8004, "Stopped due to reconfiguration");
goto done;
}
if (d->import_protocol &&
d->import_protocol->core_state != FS_HAPPY &&
d->import_protocol->core_state != FS_FEEDING)
{
cli_printf(c, 8005, "Protocol is down");
goto done;
}
if (!max--)
{
FIB_ITERATE_PUT(it, f);
return;
}
rt_show_net(c, n, d);
}
FIB_ITERATE_END(f);
if (d->stats)
cli_printf(c, 14, "%d of %d routes for %d networks", d->show_counter, d->rt_counter, d->net_counter);
else
cli_printf(c, 0, "");
done:
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)
{
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");
}
}