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bird/proto/static/static.c
Maria Matejka 10bb1c1e9d Real almost-lockless feeds and more pull-like exports
Introducing a new omnipotent internal API to just pass route updates
from whatever point wherever we want.

From now on, all the exports should be processed by RT_WALK_EXPORTS
macro, and you can also issue a separate feed-only request to just get a
feed and finish.

The exporters can now also stop and the readers must expect that to
happen and recover. Main tables don't stop, though.
2024-06-04 10:11:36 +02:00

852 lines
20 KiB
C

/*
* BIRD -- Static Route Generator
*
* (c) 1998--2000 Martin Mares <mj@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
/**
* DOC: Static
*
* The Static protocol is implemented in a straightforward way. It keeps a list
* of static routes. Routes of dest RTD_UNICAST have associated sticky node in
* the neighbor cache to be notified about gaining or losing the neighbor and
* about interface-related events (e.g. link down). They may also have a BFD
* request if associated with a BFD session. When a route is notified,
* static_decide() is used to see whether the route activeness is changed. In
* such case, the route is marked as dirty and scheduled to be announced or
* withdrawn, which is done asynchronously from event hook. Routes of other
* types (e.g. black holes) are announced all the time.
*
* Multipath routes are a bit tricky. To represent additional next hops, dummy
* static_route nodes are used, which are chained using @mp_next field and link
* to the master node by @mp_head field. Each next hop has a separate neighbor
* entry and an activeness state, but the master node is used for most purposes.
* Note that most functions DO NOT accept dummy nodes as arguments.
*
* The only other thing worth mentioning is that when asked for reconfiguration,
* Static not only compares the two configurations, but it also calculates
* difference between the lists of static routes and it just inserts the newly
* added routes, removes the obsolete ones and reannounces changed ones.
*/
#undef LOCAL_DEBUG
#include <stdlib.h>
#include "nest/bird.h"
#include "nest/iface.h"
#include "nest/protocol.h"
#include "nest/route.h"
#include "nest/mpls.h"
#include "nest/cli.h"
#include "conf/conf.h"
#include "filter/filter.h"
#include "lib/string.h"
#include "lib/alloca.h"
#include "static.h"
static inline struct rte_src * static_get_source(struct static_proto *p, uint i)
{ return i ? rt_get_source(&p->p, i) : p->p.main_source; }
static inline void static_free_source(struct rte_src *src, uint i)
{ if (i) rt_unlock_source(src); }
static void
static_announce_rte(struct static_proto *p, struct static_route *r)
{
struct rte_src *src;
ea_list *ea = NULL;
ea_set_attr_u32(&ea, &ea_gen_preference, 0, p->p.main_channel->preference);
ea_set_attr_u32(&ea, &ea_gen_source, 0, RTS_STATIC);
if (r->dest == RTD_UNICAST)
{
uint sz = 0;
for (struct static_route *r2 = r; r2; r2 = r2->mp_next)
if (r2->active)
sz += NEXTHOP_SIZE_CNT(r2->mls ? r2->mls->length / sizeof(u32) : 0);
if (!sz)
goto withdraw;
struct nexthop_adata *nhad = allocz(sz + sizeof *nhad);
struct nexthop *nh = &nhad->nh;
for (struct static_route *r2 = r; r2; r2 = r2->mp_next)
{
if (!r2->active)
continue;
nh->gw = r2->via;
nh->iface = r2->neigh->iface;
nh->flags = r2->onlink ? RNF_ONLINK : 0;
nh->weight = r2->weight;
if (r2->mls)
{
nh->labels = r2->mls->length / sizeof(u32);
memcpy(nh->label, r2->mls->data, r2->mls->length);
}
nh = NEXTHOP_NEXT(nh);
}
ea_set_attr_data(&ea, &ea_gen_nexthop, 0,
nhad->ad.data, (void *) nh - (void *) nhad->ad.data);
}
else if (r->dest == RTDX_RECURSIVE)
{
rtable *tab = ipa_is_ip4(r->via) ? p->igp_table_ip4 : p->igp_table_ip6;
u32 *labels = r->mls ? (void *) r->mls->data : NULL;
u32 lnum = r->mls ? r->mls->length / sizeof(u32) : 0;
ea_set_hostentry(&ea, p->p.main_channel->table, tab,
r->via, IPA_NONE, lnum, labels);
}
else if (r->dest)
ea_set_dest(&ea, 0, r->dest);
if (p->p.mpls_channel)
{
struct mpls_channel *mc = (void *) p->p.mpls_channel;
if (r->mpls_label != (uint) -1)
{
ea_set_attr_u32(&ea, &ea_gen_mpls_label, 0, r->mpls_label);
ea_set_attr_u32(&ea, &ea_gen_mpls_policy, 0, MPLS_POLICY_STATIC);
}
else
{
ea_set_attr_u32(&ea, &ea_gen_mpls_policy, 0, mc->label_policy);
}
}
/* Already announced */
if (r->state == SRS_CLEAN)
return;
/* We skip rta_lookup() here */
src = static_get_source(p, r->index);
rte e0 = { .attrs = ea, .src = src, .net = r->net, }, *e = &e0;
/* Evaluate the filter */
if (r->cmds)
f_eval_rte(r->cmds, e, 0, NULL, 0, NULL);
rte_update(p->p.main_channel, r->net, e, src);
static_free_source(src, r->index);
r->state = SRS_CLEAN;
return;
withdraw:
if (r->state == SRS_DOWN)
return;
src = static_get_source(p, r->index);
rte_update(p->p.main_channel, r->net, NULL, src);
static_free_source(src, r->index);
r->state = SRS_DOWN;
}
static void
static_mark_rte(struct static_proto *p, struct static_route *r)
{
if (r->state == SRS_DIRTY)
return;
r->state = SRS_DIRTY;
BUFFER_PUSH(p->marked) = r;
if (!ev_active(p->event))
ev_schedule(p->event);
}
static void
static_mark_all(struct static_proto *p)
{
struct static_config *cf = (void *) p->p.cf;
struct static_route *r;
/* We want to reload all routes, mark them as dirty */
WALK_LIST(r, cf->routes)
if (r->state == SRS_CLEAN)
r->state = SRS_DIRTY;
p->marked_all = 1;
BUFFER_FLUSH(p->marked);
if (!ev_active(p->event))
ev_schedule(p->event);
}
static void
static_mark_partial(struct static_proto *p, struct rt_feeding_request *rfr)
{
struct static_config *cf = (void *) p->p.cf;
struct static_route *r;
WALK_LIST(r, cf->routes)
if (r->state == SRS_CLEAN && (!rfr || rt_prefilter_net(&rfr->prefilter, r->net)))
{
r->state = SRS_DIRTY;
BUFFER_PUSH(p->marked) = r;
}
if (!ev_active(p->event))
ev_schedule(p->event);
rfr->done(rfr);
}
static void
static_announce_marked(void *P)
{
struct static_proto *p = P;
struct static_config *cf = (void *) p->p.cf;
struct static_route *r;
if (p->marked_all)
{
WALK_LIST(r, cf->routes)
if (r->state == SRS_DIRTY)
static_announce_rte(p, r);
p->marked_all = 0;
}
else
{
BUFFER_WALK(p->marked, r)
static_announce_rte(p, r);
BUFFER_FLUSH(p->marked);
}
}
static void
static_bfd_notify(struct bfd_request *req);
static void
static_update_bfd(struct static_proto *p, struct static_route *r)
{
/* The @r is a RTD_UNICAST next hop, may be a dummy node */
struct neighbor *nb = r->neigh;
int bfd_up = (nb->scope > 0) && r->use_bfd;
if (bfd_up && !r->bfd_req)
{
// ip_addr local = ipa_nonzero(r->local) ? r->local : nb->ifa->ip;
r->bfd_req = bfd_request_session(p->p.pool, r->via, nb->ifa->ip,
nb->iface, p->p.vrf,
static_bfd_notify, r, p->p.loop, NULL);
}
if (!bfd_up && r->bfd_req)
{
rfree(r->bfd_req);
r->bfd_req = NULL;
}
}
static int
static_decide(struct static_proto *p, struct static_route *r)
{
/* The @r is a RTD_UNICAST next hop, may be a dummy node */
struct static_config *cf = (void *) p->p.cf;
uint old_active = r->active;
if (r->neigh->scope < 0)
goto fail;
if (cf->check_link && !(r->neigh->iface->flags & IF_LINK_UP))
goto fail;
if (r->bfd_req && (r->bfd_req->state != BFD_STATE_UP))
goto fail;
r->active = 1;
return !old_active;
fail:
r->active = 0;
return old_active;
}
static void
static_add_rte(struct static_proto *p, struct static_route *r)
{
if (r->dest == RTD_UNICAST)
{
struct static_route *r2;
struct neighbor *n;
for (r2 = r; r2; r2 = r2->mp_next)
{
n = neigh_find(&p->p, r2->via, r2->iface, NEF_STICKY |
(r2->onlink ? NEF_ONLINK : 0) |
(ipa_zero(r2->via) ? NEF_IFACE : 0));
if (!n)
{
log(L_WARN "Invalid next hop %I of static route %N", r2->via, r2->net);
continue;
}
r2->neigh = n;
r2->chain = n->data;
n->data = r2;
static_update_bfd(p, r2);
static_decide(p, r2);
}
}
static_announce_rte(p, r);
}
static void
static_reset_rte(struct static_proto *p UNUSED, struct static_route *r)
{
struct static_route *r2;
for (r2 = r; r2; r2 = r2->mp_next)
{
r2->neigh = NULL;
r2->chain = NULL;
r2->state = 0;
r2->active = 0;
rfree(r2->bfd_req);
r2->bfd_req = NULL;
}
}
static void
static_remove_rte(struct static_proto *p, struct static_route *r)
{
if (r->state)
{
struct rte_src *src = static_get_source(p, r->index);
rte_update(p->p.main_channel, r->net, NULL, src);
static_free_source(src, r->index);
}
static_reset_rte(p, r);
}
static inline int
static_same_dest(struct static_route *x, struct static_route *y)
{
if (x->dest != y->dest)
return 0;
switch (x->dest)
{
case RTD_UNICAST:
for (; x && y; x = x->mp_next, y = y->mp_next)
{
if (!ipa_equal(x->via, y->via) ||
(x->iface != y->iface) ||
(x->onlink != y->onlink) ||
(x->weight != y->weight) ||
(x->use_bfd != y->use_bfd) ||
(!x->mls != !y->mls) ||
((x->mls) && (y->mls) && adata_same(x->mls, y->mls)))
return 0;
}
return !x && !y;
case RTDX_RECURSIVE:
if (!ipa_equal(x->via, y->via) ||
(!x->mls != !y->mls) ||
((x->mls) && (y->mls) && adata_same(x->mls, y->mls)))
return 0;
return 1;
default:
return 1;
}
}
static inline int
static_same_rte(struct static_route *or, struct static_route *nr)
{
/* Note that i_same() requires arguments in (new, old) order */
return (or->mpls_label == nr->mpls_label) && static_same_dest(or, nr) && f_same(nr->cmds, or->cmds);
}
static void
static_reconfigure_rte(struct static_proto *p, struct static_route *or, struct static_route *nr)
{
if ((or->state == SRS_CLEAN) && !static_same_rte(or, nr))
nr->state = SRS_DIRTY;
else
nr->state = or->state;
static_add_rte(p, nr);
static_reset_rte(p, or);
}
static void
static_neigh_notify(struct neighbor *n)
{
struct static_proto *p = (void *) n->proto;
struct static_route *r;
DBG("Static: neighbor notify for %I: iface %p\n", n->addr, n->iface);
for (r = n->data; r; r = r->chain)
{
static_update_bfd(p, r);
if (static_decide(p, r))
static_mark_rte(p, r->mp_head);
}
}
static void
static_bfd_notify(struct bfd_request *req)
{
struct static_route *r = req->data;
struct static_proto *p = (void *) r->neigh->proto;
// if (req->down) TRACE(D_EVENTS, "BFD session down for nbr %I on %s", XXXX);
if (static_decide(p, r))
static_mark_rte(p, r->mp_head);
}
static int
static_reload_routes(struct channel *C, struct rt_feeding_request *rfr)
{
struct static_proto *p = (void *) C->proto;
TRACE(D_EVENTS, "Scheduling route reload");
if (rfr)
static_mark_partial(p, rfr);
else
static_mark_all(p);
return 1;
}
static int
static_rte_better(const rte *new, const rte *old)
{
u32 n = ea_get_int(new->attrs, &ea_gen_igp_metric, IGP_METRIC_UNKNOWN);
u32 o = ea_get_int(old->attrs, &ea_gen_igp_metric, IGP_METRIC_UNKNOWN);
return n < o;
}
static int
static_rte_mergable(const rte *pri, const rte *sec)
{
u32 a = ea_get_int(pri->attrs, &ea_gen_igp_metric, IGP_METRIC_UNKNOWN);
u32 b = ea_get_int(sec->attrs, &ea_gen_igp_metric, IGP_METRIC_UNKNOWN);
return a == b;
}
static void static_index_routes(struct static_config *cf);
static void
static_postconfig(struct proto_config *CF)
{
struct static_config *cf = (void *) CF;
struct static_route *r;
/* If there is just a MPLS channel, use it as a main channel */
if (!CF->net_type && proto_cf_mpls_channel(CF))
CF->net_type = NET_MPLS;
if (! proto_cf_main_channel(CF))
cf_error("Channel not specified");
struct channel_config *cc = proto_cf_main_channel(CF);
struct channel_config *mc = proto_cf_mpls_channel(CF);
if (!cf->igp_table_ip4)
cf->igp_table_ip4 = (cc->table->addr_type == NET_IP4) ?
cc->table : rt_get_default_table(cf->c.global, NET_IP4);
if (!cf->igp_table_ip6)
cf->igp_table_ip6 = (cc->table->addr_type == NET_IP6) ?
cc->table : rt_get_default_table(cf->c.global, NET_IP6);
WALK_LIST(r, cf->routes)
{
if (r->net && (r->net->type != CF->net_type))
cf_error("Route %N incompatible with channel type", r->net);
if ((r->mpls_label != (uint) -1) && !mc)
cf_error("Route %N has MPLS label, but MPLS channel not specified", r->net);
}
static_index_routes(cf);
}
static struct rte_owner_class static_rte_owner_class;
static struct proto *
static_init(struct proto_config *CF)
{
struct proto *P = proto_new(CF);
struct static_proto *p = (void *) P;
struct static_config *cf = (void *) CF;
P->main_channel = proto_add_channel(P, proto_cf_main_channel(CF));
proto_configure_mpls_channel(P, CF, RTS_STATIC);
P->iface_sub.neigh_notify = static_neigh_notify;
P->reload_routes = static_reload_routes;
P->sources.class = &static_rte_owner_class;
if (cf->igp_table_ip4)
p->igp_table_ip4 = cf->igp_table_ip4->table;
if (cf->igp_table_ip6)
p->igp_table_ip6 = cf->igp_table_ip6->table;
return P;
}
static int
static_start(struct proto *P)
{
struct static_proto *p = (void *) P;
struct static_config *cf = (void *) P->cf;
struct static_route *r;
if (p->igp_table_ip4)
rt_lock_table(p->igp_table_ip4);
if (p->igp_table_ip6)
rt_lock_table(p->igp_table_ip6);
p->event = ev_new_init(p->p.pool, static_announce_marked, p);
BUFFER_INIT(p->marked, p->p.pool, 4);
/* We have to go UP before routes could be installed */
proto_notify_state(P, PS_UP);
WALK_LIST(r, cf->routes)
TMP_SAVED
static_add_rte(p, r);
return PS_UP;
}
static int
static_shutdown(struct proto *P)
{
struct static_proto *p = (void *) P;
struct static_config *cf = (void *) P->cf;
struct static_route *r;
/* Just reset the flag, the routes will be flushed by the nest */
WALK_LIST(r, cf->routes)
static_reset_rte(p, r);
return PS_DOWN;
}
static void
static_cleanup(struct proto *P)
{
struct static_proto *p = (void *) P;
if (p->igp_table_ip4)
rt_unlock_table(p->igp_table_ip4);
if (p->igp_table_ip6)
rt_unlock_table(p->igp_table_ip6);
}
static void
static_dump_rte(struct static_route *r)
{
debug("%-1N (%u): ", r->net, r->index);
if (r->dest == RTD_UNICAST)
if (r->iface && ipa_zero(r->via))
debug("dev %s\n", r->iface->name);
else
debug("via %I%J\n", r->via, r->iface);
else
debug("rtd %d\n", r->dest);
}
static void
static_dump(struct proto *P)
{
struct static_config *c = (void *) P->cf;
struct static_route *r;
debug("Static routes:\n");
WALK_LIST(r, c->routes)
static_dump_rte(r);
}
#define IGP_TABLE(cf, sym) ((cf)->igp_table_##sym ? (cf)->igp_table_##sym ->table : NULL )
static inline int srt_equal(const struct static_route *a, const struct static_route *b)
{ return net_equal(a->net, b->net) && (a->index == b->index); }
static inline int srt_compare(const struct static_route *a, const struct static_route *b)
{ return net_compare(a->net, b->net) ?: uint_cmp(a->index, b->index); }
static inline int srt_compare_qsort(const void *A, const void *B)
{
return srt_compare(*(const struct static_route * const *)A,
*(const struct static_route * const *)B);
}
static void
static_index_routes(struct static_config *cf)
{
struct static_route *rt, **buf;
uint num, i, v;
num = list_length(&cf->routes);
buf = xmalloc(num * sizeof(void *));
/* Initialize with sequential indexes to ensure stable sorting */
i = 0;
WALK_LIST(rt, cf->routes)
{
buf[i] = rt;
rt->index = i++;
}
qsort(buf, num, sizeof(struct static_route *), srt_compare_qsort);
/* Compute proper indexes - sequential for routes with same network */
for (i = 0, v = 0, rt = NULL; i < num; i++, v++)
{
if (rt && !net_equal(buf[i]->net, rt->net))
v = 0;
rt = buf[i];
rt->index = v;
}
xfree(buf);
}
static int
static_reconfigure(struct proto *P, struct proto_config *CF)
{
struct static_proto *p = (void *) P;
struct static_config *o = (void *) P->cf;
struct static_config *n = (void *) CF;
struct static_route *r, *r2, *or, *nr;
/* Check change in IGP tables */
if ((IGP_TABLE(o, ip4) != IGP_TABLE(n, ip4)) ||
(IGP_TABLE(o, ip6) != IGP_TABLE(n, ip6)))
return 0;
if (!proto_configure_channel(P, &P->main_channel, proto_cf_main_channel(CF)) ||
!proto_configure_mpls_channel(P, CF, RTS_STATIC))
return 0;
p->p.cf = CF;
/* Reset route lists in neighbor entries */
WALK_LIST(r, o->routes)
for (r2 = r; r2; r2 = r2->mp_next)
if (r2->neigh)
r2->neigh->data = NULL;
/* Reconfigure initial matching sequence */
for (or = HEAD(o->routes), nr = HEAD(n->routes);
NODE_VALID(or) && NODE_VALID(nr) && srt_equal(or, nr);
or = NODE_NEXT(or), nr = NODE_NEXT(nr))
static_reconfigure_rte(p, or, nr);
if (!NODE_VALID(or) && !NODE_VALID(nr))
return 1;
/* Reconfigure remaining routes, sort them to find matching pairs */
struct static_route *or2, *nr2, **orbuf, **nrbuf;
uint ornum = 0, nrnum = 0, orpos = 0, nrpos = 0, i;
for (or2 = or; NODE_VALID(or2); or2 = NODE_NEXT(or2))
ornum++;
for (nr2 = nr; NODE_VALID(nr2); nr2 = NODE_NEXT(nr2))
nrnum++;
orbuf = xmalloc(ornum * sizeof(void *));
nrbuf = xmalloc(nrnum * sizeof(void *));
for (i = 0, or2 = or; i < ornum; i++, or2 = NODE_NEXT(or2))
orbuf[i] = or2;
for (i = 0, nr2 = nr; i < nrnum; i++, nr2 = NODE_NEXT(nr2))
nrbuf[i] = nr2;
qsort(orbuf, ornum, sizeof(struct static_route *), srt_compare_qsort);
qsort(nrbuf, nrnum, sizeof(struct static_route *), srt_compare_qsort);
while ((orpos < ornum) && (nrpos < nrnum))
{
int x = srt_compare(orbuf[orpos], nrbuf[nrpos]);
if (x < 0)
static_remove_rte(p, orbuf[orpos++]);
else if (x > 0)
static_add_rte(p, nrbuf[nrpos++]);
else
static_reconfigure_rte(p, orbuf[orpos++], nrbuf[nrpos++]);
}
while (orpos < ornum)
static_remove_rte(p, orbuf[orpos++]);
while (nrpos < nrnum)
static_add_rte(p, nrbuf[nrpos++]);
xfree(orbuf);
xfree(nrbuf);
/* All dirty routes were announced anyways */
BUFFER_FLUSH(p->marked);
p->marked_all = 0;
return 1;
}
static void
static_copy_config(struct proto_config *dest, struct proto_config *src)
{
struct static_config *d = (struct static_config *) dest;
struct static_config *s = (struct static_config *) src;
struct static_route *srt, *snh;
/* Copy route list */
init_list(&d->routes);
WALK_LIST(srt, s->routes)
{
struct static_route *drt = NULL, *dnh = NULL, **dnp = &drt;
for (snh = srt; snh; snh = snh->mp_next)
{
dnh = cfg_alloc(sizeof(struct static_route));
memcpy(dnh, snh, sizeof(struct static_route));
memset(&dnh->n, 0, sizeof(node));
if (!drt)
add_tail(&d->routes, &(dnh->n));
*dnp = dnh;
dnp = &(dnh->mp_next);
if (snh->mp_head)
dnh->mp_head = drt;
}
}
}
static void
static_get_route_info(const rte *rte, byte *buf)
{
eattr *a = ea_find(rte->attrs, &ea_gen_igp_metric);
u32 pref = rt_get_preference(rte);
if (a && (a->u.data < IGP_METRIC_UNKNOWN))
buf += bsprintf(buf, " (%d/%u)", pref, a->u.data);
else
buf += bsprintf(buf, " (%d)", pref);
}
static void
static_show_rt(struct static_route *r)
{
switch (r->dest)
{
case RTD_UNICAST:
{
struct static_route *r2;
cli_msg(-1009, "%N", r->net);
for (r2 = r; r2; r2 = r2->mp_next)
{
if (r2->iface && ipa_zero(r2->via))
cli_msg(-1009, "\tdev %s%s", r2->iface->name,
r2->active ? "" : " (dormant)");
else
cli_msg(-1009, "\tvia %I%J%s%s%s", r2->via, r2->iface,
r2->onlink ? " onlink" : "",
r2->bfd_req ? " (bfd)" : "",
r2->active ? "" : " (dormant)");
}
break;
}
case RTD_NONE:
case RTD_BLACKHOLE:
case RTD_UNREACHABLE:
case RTD_PROHIBIT:
cli_msg(-1009, "%N\t%s", r->net, rta_dest_names[r->dest]);
break;
case RTDX_RECURSIVE:
cli_msg(-1009, "%N\trecursive %I", r->net, r->via);
break;
}
}
void
static_show(struct proto *P)
{
struct static_config *c = (void *) P->cf;
struct static_route *r;
WALK_LIST(r, c->routes)
static_show_rt(r);
}
static struct rte_owner_class static_rte_owner_class = {
.get_route_info = static_get_route_info,
.rte_better = static_rte_better,
.rte_mergable = static_rte_mergable,
};
struct protocol proto_static = {
.name = "Static",
.template = "static%d",
.preference = DEF_PREF_STATIC,
.channel_mask = NB_ANY,
.proto_size = sizeof(struct static_proto),
.config_size = sizeof(struct static_config),
.startup = PROTOCOL_STARTUP_GENERATOR,
.postconfig = static_postconfig,
.init = static_init,
.dump = static_dump,
.start = static_start,
.shutdown = static_shutdown,
.cleanup = static_cleanup,
.reconfigure = static_reconfigure,
.copy_config = static_copy_config,
};
void
static_build(void)
{
proto_build(&proto_static);
}