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bird/proto/static/static.c
Ondrej Zajicek 53434e44a9 Better flushing of interfaces.
When device protocol goes down, interfaces should be flushed
asynchronously (in the same way like routes from protocols are flushed),
when protocol goes to DOWN/HUNGRY.

This fixes the problem with static routes staying in kernel routing
table after BIRD shutdown.
2010-02-27 16:00:07 +01:00

319 lines
7.2 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
* two lists of static routes: one containing interface routes and one
* holding the remaining ones. Interface routes are inserted and removed according
* to interface events received from the core via the if_notify() hook. Routes
* pointing to a neighboring router use a sticky node in the neighbor cache
* to be notified about gaining or losing the neighbor. Special
* routes like black holes or rejects are inserted all the time.
*
* 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 and removes the obsolete ones.
*/
#undef LOCAL_DEBUG
#include "nest/bird.h"
#include "nest/iface.h"
#include "nest/protocol.h"
#include "nest/route.h"
#include "nest/cli.h"
#include "conf/conf.h"
#include "lib/string.h"
#include "static.h"
static void
static_install(struct proto *p, struct static_route *r, struct iface *ifa)
{
net *n;
rta a, *aa;
rte *e;
if (r->installed)
return;
DBG("Installing static route %I/%d, rtd=%d\n", r->net, r->masklen, r->dest);
bzero(&a, sizeof(a));
a.proto = p;
a.source = (r->dest == RTD_DEVICE) ? RTS_STATIC_DEVICE : RTS_STATIC;
a.scope = SCOPE_UNIVERSE;
a.cast = RTC_UNICAST;
a.dest = r->dest;
a.gw = r->via;
a.iface = ifa;
aa = rta_lookup(&a);
n = net_get(p->table, r->net, r->masklen);
e = rte_get_temp(aa);
e->net = n;
e->pflags = 0;
rte_update(p->table, n, p, p, e);
r->installed = 1;
}
static void
static_remove(struct proto *p, struct static_route *r)
{
net *n;
if (!r->installed)
return;
DBG("Removing static route %I/%d\n", r->net, r->masklen);
n = net_find(p->table, r->net, r->masklen);
if (n)
rte_update(p->table, n, p, p, NULL);
r->installed = 0;
}
static void
static_add(struct proto *p, struct static_route *r)
{
DBG("static_add(%I/%d,%d)\n", r->net, r->masklen, r->dest);
switch (r->dest)
{
case RTD_ROUTER:
{
struct neighbor *n = neigh_find(p, &r->via, NEF_STICKY);
if (n)
{
r->chain = n->data;
n->data = r;
r->neigh = n;
if (n->iface)
static_install(p, r, n->iface);
}
else
log(L_ERR "Static route destination %I is invalid. Ignoring.", r->via);
break;
}
case RTD_DEVICE:
break;
default:
static_install(p, r, NULL);
}
}
static int
static_start(struct proto *p)
{
struct static_config *c = (void *) p->cf;
struct static_route *r;
DBG("Static: take off!\n");
WALK_LIST(r, c->other_routes)
static_add(p, r);
return PS_UP;
}
static int
static_shutdown(struct proto *p)
{
struct static_config *c = (void *) p->cf;
struct static_route *r;
/* Just reset the flag, the routes will be flushed by the nest */
WALK_LIST(r, c->iface_routes)
r->installed = 0;
WALK_LIST(r, c->other_routes)
r->installed = 0;
return PS_DOWN;
}
static void
static_neigh_notify(struct neighbor *n)
{
struct proto *p = 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)
if (n->iface)
static_install(p, r, n->iface);
else
static_remove(p, r);
}
static void
static_dump_rt(struct static_route *r)
{
debug("%-1I/%2d: ", r->net, r->masklen);
switch (r->dest)
{
case RTD_ROUTER:
debug("via %I\n", r->via);
break;
case RTD_DEVICE:
debug("dev %s\n", r->if_name);
break;
default:
debug("rtd %d\n", r->dest);
break;
}
}
static void
static_dump(struct proto *p)
{
struct static_config *c = (void *) p->cf;
struct static_route *r;
debug("Independent static routes:\n");
WALK_LIST(r, c->other_routes)
static_dump_rt(r);
debug("Device static routes:\n");
WALK_LIST(r, c->iface_routes)
static_dump_rt(r);
}
static void
static_if_notify(struct proto *p, unsigned flags, struct iface *i)
{
struct static_route *r;
struct static_config *c = (void *) p->cf;
if (flags & IF_CHANGE_UP)
{
WALK_LIST(r, c->iface_routes)
if (!strcmp(r->if_name, i->name))
static_install(p, r, i);
}
else if (flags & IF_CHANGE_DOWN)
{
WALK_LIST(r, c->iface_routes)
if (!strcmp(r->if_name, i->name))
static_remove(p, r);
}
}
void
static_init_config(struct static_config *c)
{
c->c.preference = DEF_PREF_STATIC;
init_list(&c->iface_routes);
init_list(&c->other_routes);
}
static struct proto *
static_init(struct proto_config *c)
{
struct proto *p = proto_new(c, sizeof(struct proto));
p->neigh_notify = static_neigh_notify;
p->if_notify = static_if_notify;
return p;
}
static int
static_same_route(struct static_route *x, struct static_route *y)
{
return ipa_equal(x->net, y->net)
&& x->masklen == y->masklen
&& x->dest == y->dest
&& (x->dest != RTD_ROUTER || ipa_equal(x->via, y->via))
&& (x->dest != RTD_DEVICE || !strcmp(x->if_name, y->if_name))
;
}
static void
static_match(struct proto *p, struct static_route *r, struct static_config *n)
{
struct static_route *t;
if (r->neigh)
r->neigh->data = NULL;
WALK_LIST(t, n->iface_routes)
if (static_same_route(r, t))
{
t->installed = 1;
return;
}
WALK_LIST(t, n->other_routes)
if (static_same_route(r, t))
{
t->installed = 1;
return;
}
static_remove(p, r);
}
static int
static_reconfigure(struct proto *p, struct proto_config *new)
{
struct static_config *o = (void *) p->cf;
struct static_config *n = (void *) new;
struct static_route *r;
/* Delete all obsolete routes and reset neighbor entries */
WALK_LIST(r, o->iface_routes)
static_match(p, r, n);
WALK_LIST(r, o->other_routes)
static_match(p, r, n);
/* Now add all new routes, those not changed will be ignored by static_install() */
WALK_LIST(r, n->iface_routes)
{
struct iface *ifa;
if (ifa = if_find_by_name(r->if_name))
static_install(p, r, ifa);
}
WALK_LIST(r, n->other_routes)
static_add(p, r);
return 1;
}
struct protocol proto_static = {
name: "Static",
template: "static%d",
init: static_init,
dump: static_dump,
start: static_start,
shutdown: static_shutdown,
reconfigure: static_reconfigure,
};
static void
static_show_rt(struct static_route *r)
{
byte via[STD_ADDRESS_P_LENGTH + 16];
switch (r->dest)
{
case RTD_ROUTER: bsprintf(via, "via %I", r->via); break;
case RTD_DEVICE: bsprintf(via, "dev %s", r->if_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, "???");
}
cli_msg(-1009, "%I/%d %s%s", r->net, r->masklen, via, r->installed ? "" : " (dormant)");
}
void
static_show(struct proto *P)
{
struct static_config *c = (void *) P->cf;
struct static_route *r;
WALK_LIST(r, c->other_routes)
static_show_rt(r);
WALK_LIST(r, c->iface_routes)
static_show_rt(r);
cli_msg(0, "");
}