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mirror of https://gitlab.nic.cz/labs/bird.git synced 2024-12-22 17:51:53 +00:00
bird/nest/rt-show.c
Ondrej Zajicek (work) 5a89edc6fd Nest: Implement locking of prefix tries during walks
The prune loop may may rebuild the prefix trie and therefore invalidate
walk state for asynchronous walks (used in 'show route in' cmd). Fix it
by adding locking that keeps the old trie in memory until current walks
are done.

In future this could be improved by rebuilding trie walk states (by
lookup for last found prefix) after the prefix trie rebuild.
2022-02-06 23:27:13 +01:00

492 lines
11 KiB
C

/*
* BIRD -- Route Display Routines
*
* (c) 1998--2000 Martin Mares <mj@ucw.cz>
* (c) 2017 Jan Moskyto Matejka <mq@jmq.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 "filter/filter.h"
#include "filter/data.h"
#include "sysdep/unix/krt.h"
static void
rt_show_table(struct cli *c, struct rt_show_data *d)
{
/* No table blocks in 'show route count' */
if (d->stats == 2)
return;
if (d->last_table) cli_printf(c, -1007, "");
cli_printf(c, -1007, "Table %s:", d->tab->table->name);
d->last_table = d->tab;
}
static inline struct krt_proto *
rt_show_get_kernel(struct rt_show_data *d)
{
struct proto_config *krt = d->tab->table->config->krt_attached;
return krt ? (struct krt_proto *) krt->proto : NULL;
}
static void
rt_show_rte(struct cli *c, byte *ia, rte *e, struct rt_show_data *d, int primary)
{
byte from[IPA_MAX_TEXT_LENGTH+8];
byte tm[TM_DATETIME_BUFFER_SIZE], info[256];
rta *a = e->attrs;
int sync_error = d->kernel ? krt_get_sync_error(d->kernel, e) : 0;
void (*get_route_info)(struct rte *, byte *buf);
struct nexthop *nh;
tm_format_time(tm, &config->tf_route, e->lastmod);
if (ipa_nonzero(a->from) && !ipa_equal(a->from, a->nh.gw))
bsprintf(from, " from %I", a->from);
else
from[0] = 0;
/* Need to normalize the extended attributes */
if (d->verbose && !rta_is_cached(a) && a->eattrs)
ea_normalize(a->eattrs);
get_route_info = a->src->proto->proto->get_route_info;
if (get_route_info)
get_route_info(e, info);
else
bsprintf(info, " (%d)", e->pref);
if (d->last_table != d->tab)
rt_show_table(c, d);
cli_printf(c, -1007, "%-20s %s [%s %s%s]%s%s", ia, rta_dest_name(a->dest),
a->src->proto->name, tm, from, primary ? (sync_error ? " !" : " *") : "", info);
if (a->dest == RTD_UNICAST)
for (nh = &(a->nh); nh; nh = nh->next)
{
char mpls[MPLS_MAX_LABEL_STACK*12 + 5], *lsp = mpls;
char *onlink = (nh->flags & RNF_ONLINK) ? " onlink" : "";
char weight[16] = "";
if (nh->labels)
{
lsp += bsprintf(lsp, " mpls %d", nh->label[0]);
for (int i=1;i<nh->labels; i++)
lsp += bsprintf(lsp, "/%d", nh->label[i]);
}
*lsp = '\0';
if (a->nh.next)
bsprintf(weight, " weight %d", nh->weight + 1);
if (ipa_nonzero(nh->gw))
cli_printf(c, -1007, "\tvia %I on %s%s%s%s",
nh->gw, nh->iface->name, mpls, onlink, weight);
else
cli_printf(c, -1007, "\tdev %s%s%s",
nh->iface->name, mpls, onlink, weight);
}
if (d->verbose)
rta_show(c, a);
}
static void
rt_show_net(struct cli *c, net *n, struct rt_show_data *d)
{
rte *e, *ee;
byte ia[NET_MAX_TEXT_LENGTH+1];
struct channel *ec = d->tab->export_channel;
/* The Clang static analyzer complains that ec may be NULL.
* It should be ensured to be not NULL by rt_show_prepare_tables() */
ASSUME(!d->export_mode || ec);
int first = 1;
int first_show = 1;
int pass = 0;
for (e = n->routes; e; e = e->next)
{
if (rte_is_filtered(e) != d->filtered)
continue;
d->rt_counter++;
d->net_counter += first;
first = 0;
if (pass)
continue;
ee = e;
rte_make_tmp_attrs(&e, c->show_pool, NULL);
/* Export channel is down, do not try to export routes to it */
if (ec && (ec->export_state == ES_DOWN))
goto skip;
if (d->export_mode == RSEM_EXPORTED)
{
if (!bmap_test(&ec->export_map, ee->id))
goto skip;
// if (ec->ra_mode != RA_ANY)
// pass = 1;
}
else if ((d->export_mode == RSEM_EXPORT) && (ec->ra_mode == RA_MERGED))
{
/* Special case for merged export */
rte *rt_free;
e = rt_export_merged(ec, n, &rt_free, c->show_pool, 1);
pass = 1;
if (!e)
{ e = ee; goto skip; }
}
else if (d->export_mode)
{
struct proto *ep = ec->proto;
int ic = ep->preexport ? ep->preexport(ep, &e, c->show_pool) : 0;
if (ec->ra_mode == RA_OPTIMAL || ec->ra_mode == RA_MERGED)
pass = 1;
if (ic < 0)
goto skip;
if (d->export_mode > RSEM_PREEXPORT)
{
/*
* FIXME - This shows what should be exported according to current
* filters, but not what was really exported. 'configure soft'
* command may change the export filter and do not update routes.
*/
int do_export = (ic > 0) ||
(f_run(ec->out_filter, &e, c->show_pool, FF_SILENT) <= F_ACCEPT);
if (do_export != (d->export_mode == RSEM_EXPORT))
goto skip;
if ((d->export_mode == RSEM_EXPORT) && (ec->ra_mode == RA_ACCEPTED))
pass = 1;
}
}
if (d->show_protocol && (d->show_protocol != e->attrs->src->proto))
goto skip;
if (f_run(d->filter, &e, c->show_pool, 0) > F_ACCEPT)
goto skip;
if (d->stats < 2)
{
if (first_show)
net_format(n->n.addr, ia, sizeof(ia));
else
ia[0] = 0;
rt_show_rte(c, ia, e, d, (e->net->routes == ee));
first_show = 0;
}
d->show_counter++;
skip:
if (e != ee)
{
rte_free(e);
e = ee;
}
lp_flush(c->show_pool);
if (d->primary_only)
break;
}
}
static void
rt_show_cleanup(struct cli *c)
{
struct rt_show_data *d = c->rover;
struct rt_show_data_rtable *tab;
/* Unlink the iterator */
if (d->table_open && !d->trie_walk)
fit_get(&d->tab->table->fib, &d->fit);
if (d->walk_lock)
rt_unlock_trie(d->tab->table, d->walk_lock);
/* Unlock referenced tables */
WALK_LIST(tab, d->tables)
rt_unlock_table(tab->table);
}
static void
rt_show_cont(struct cli *c)
{
struct rt_show_data *d = c->rover;
struct rtable *tab = d->tab->table;
#ifdef DEBUGGING
unsigned max = 4;
#else
unsigned max = 64;
#endif
struct fib *fib = &tab->fib;
struct fib_iterator *it = &d->fit;
if (d->running_on_config && (d->running_on_config != config))
{
cli_printf(c, 8004, "Stopped due to reconfiguration");
goto done;
}
if (!d->table_open)
{
/* We use either trie-based walk or fib-based walk */
d->trie_walk = tab->trie &&
(d->addr_mode == RSD_ADDR_IN) &&
net_val_match(tab->addr_type, NB_IP);
if (d->trie_walk && !d->walk_state)
d->walk_state = lp_allocz(c->parser_pool, sizeof (struct f_trie_walk_state));
if (d->trie_walk)
{
d->walk_lock = rt_lock_trie(tab);
trie_walk_init(d->walk_state, tab->trie, d->addr);
}
else
FIB_ITERATE_INIT(&d->fit, &tab->fib);
d->table_open = 1;
d->table_counter++;
d->kernel = rt_show_get_kernel(d);
d->show_counter_last = d->show_counter;
d->rt_counter_last = d->rt_counter;
d->net_counter_last = d->net_counter;
if (d->tables_defined_by & RSD_TDB_SET)
rt_show_table(c, d);
}
if (d->trie_walk)
{
/* Trie-based walk */
net_addr addr;
while (trie_walk_next(d->walk_state, &addr))
{
net *n = net_find(tab, &addr);
if (!n)
continue;
rt_show_net(c, n, d);
if (!--max)
return;
}
rt_unlock_trie(tab, d->walk_lock);
d->walk_lock = NULL;
}
else
{
/* fib-based walk */
FIB_ITERATE_START(fib, it, net, n)
{
if ((d->addr_mode == RSD_ADDR_IN) && (!net_in_netX(n->n.addr, d->addr)))
goto next;
if (!max--)
{
FIB_ITERATE_PUT(it);
return;
}
rt_show_net(c, n, d);
next:;
}
FIB_ITERATE_END;
}
if (d->stats)
{
if (d->last_table != d->tab)
rt_show_table(c, d);
cli_printf(c, -1007, "%d of %d routes for %d networks in table %s",
d->show_counter - d->show_counter_last, d->rt_counter - d->rt_counter_last,
d->net_counter - d->net_counter_last, tab->name);
}
d->kernel = NULL;
d->table_open = 0;
d->tab = NODE_NEXT(d->tab);
if (NODE_VALID(d->tab))
return;
if (d->stats && (d->table_counter > 1))
{
if (d->last_table) cli_printf(c, -1007, "");
cli_printf(c, 14, "Total: %d of %d routes for %d networks in %d tables",
d->show_counter, d->rt_counter, d->net_counter, d->table_counter);
}
else
cli_printf(c, 0, "");
done:
rt_show_cleanup(c);
c->cont = c->cleanup = NULL;
}
struct rt_show_data_rtable *
rt_show_add_table(struct rt_show_data *d, rtable *t)
{
struct rt_show_data_rtable *tab = cfg_allocz(sizeof(struct rt_show_data_rtable));
tab->table = t;
add_tail(&(d->tables), &(tab->n));
return tab;
}
static inline void
rt_show_get_default_tables(struct rt_show_data *d)
{
struct channel *c;
struct rt_show_data_rtable *tab;
if (d->export_channel)
{
c = d->export_channel;
tab = rt_show_add_table(d, c->table);
tab->export_channel = c;
return;
}
if (d->export_protocol)
{
WALK_LIST(c, d->export_protocol->channels)
{
if (c->export_state == ES_DOWN)
continue;
tab = rt_show_add_table(d, c->table);
tab->export_channel = c;
}
return;
}
if (d->show_protocol)
{
WALK_LIST(c, d->show_protocol->channels)
rt_show_add_table(d, c->table);
return;
}
for (int i=1; i<NET_MAX; i++)
if (config->def_tables[i])
rt_show_add_table(d, config->def_tables[i]->table);
}
static inline void
rt_show_prepare_tables(struct rt_show_data *d)
{
struct rt_show_data_rtable *tab, *tabx;
/* Add implicit tables if no table is specified */
if (EMPTY_LIST(d->tables))
rt_show_get_default_tables(d);
WALK_LIST_DELSAFE(tab, tabx, d->tables)
{
/* Ensure there is defined export_channel for each table */
if (d->export_mode)
{
if (!tab->export_channel && d->export_channel &&
(tab->table == d->export_channel->table))
tab->export_channel = d->export_channel;
if (!tab->export_channel && d->export_protocol)
tab->export_channel = proto_find_channel_by_table(d->export_protocol, tab->table);
if (!tab->export_channel)
{
if (d->tables_defined_by & RSD_TDB_NMN)
cf_error("No export channel for table %s", tab->table->name);
rem_node(&(tab->n));
continue;
}
}
/* Ensure specified network is compatible with each table */
if (d->addr && (tab->table->addr_type != d->addr->type))
{
if (d->tables_defined_by & RSD_TDB_NMN)
cf_error("Incompatible type of prefix/ip for table %s", tab->table->name);
rem_node(&(tab->n));
continue;
}
}
/* Ensure there is at least one table */
if (EMPTY_LIST(d->tables))
cf_error("No valid tables");
}
void
rt_show(struct rt_show_data *d)
{
struct rt_show_data_rtable *tab;
net *n;
/* Filtered routes are neither exported nor have sensible ordering */
if (d->filtered && (d->export_mode || d->primary_only))
cf_error("Incompatible show route options");
rt_show_prepare_tables(d);
if (!d->addr || (d->addr_mode == RSD_ADDR_IN))
{
WALK_LIST(tab, d->tables)
rt_lock_table(tab->table);
/* There is at least one table */
d->tab = HEAD(d->tables);
this_cli->cont = rt_show_cont;
this_cli->cleanup = rt_show_cleanup;
this_cli->rover = d;
}
else
{
WALK_LIST(tab, d->tables)
{
d->tab = tab;
d->kernel = rt_show_get_kernel(d);
if (d->addr_mode == RSD_ADDR_FOR)
n = net_route(tab->table, d->addr);
else
n = net_find(tab->table, d->addr);
if (n)
rt_show_net(this_cli, n, d);
}
if (d->rt_counter)
cli_msg(0, "");
else
cli_msg(8001, "Network not found");
}
}