bird/sysdep/unix/krt.c

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/*
* BIRD -- UNIX Kernel Synchronization
*
* (c) 1998--2000 Martin Mares <mj@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
/**
* DOC: Kernel synchronization
*
* This system dependent module implements the Kernel and Device protocol,
* that is synchronization of interface lists and routing tables with the
* OS kernel.
*
* The whole kernel synchronization is a bit messy and touches some internals
* of the routing table engine, because routing table maintenance is a typical
* example of the proverbial compatibility between different Unices and we want
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* to keep the overhead of our KRT business as low as possible and avoid maintaining
* a local routing table copy.
*
* The kernel syncer can work in three different modes (according to system config header):
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* Either with a single routing table and single KRT protocol [traditional UNIX]
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* or with many routing tables and separate KRT protocols for all of them
* or with many routing tables, but every scan including all tables, so we start
* separate KRT protocols which cooperate with each other [Linux].
* In this case, we keep only a single scan timer.
*
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* We use FIB node flags in the routing table to keep track of route
* synchronization status. We also attach temporary &rte's to the routing table,
* but it cannot do any harm to the rest of BIRD since table synchronization is
* an atomic process.
*
* When starting up, we cheat by looking if there is another
* KRT instance to be initialized later and performing table scan
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* only once for all the instances.
*
* The code uses OS-dependent parts for kernel updates and scans. These parts are
* in more specific sysdep directories (e.g. sysdep/linux) in functions krt_sys_*
* and kif_sys_* (and some others like krt_replace_rte()) and krt-sys.h header file.
* This is also used for platform specific protocol options and route attributes.
*
* There was also an old code that used traditional UNIX ioctls for these tasks.
* It was unmaintained and later removed. For reference, see sysdep/krt-* files
* in commit 396dfa9042305f62da1f56589c4b98fac57fc2f6
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*/
/*
* If you are brave enough, continue now. You cannot say you haven't been warned.
*/
#undef LOCAL_DEBUG
#include "nest/bird.h"
#include "nest/iface.h"
#include "nest/route.h"
#include "nest/protocol.h"
#include "filter/filter.h"
#include "lib/timer.h"
#include "conf/conf.h"
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#include "lib/string.h"
#include "unix.h"
#include "krt.h"
/*
* Global resources
*/
pool *krt_pool;
static linpool *krt_filter_lp;
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static list krt_proto_list;
void
krt_io_init(void)
{
krt_pool = rp_new(&root_pool, "Kernel Syncer");
krt_filter_lp = lp_new(krt_pool, 4080);
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init_list(&krt_proto_list);
}
/*
* Interfaces
*/
static struct kif_config *kif_cf;
static struct kif_proto *kif_proto;
static timer *kif_scan_timer;
static bird_clock_t kif_last_shot;
static void
kif_scan(timer *t)
{
struct kif_proto *p = t->data;
KRT_TRACE(p, D_EVENTS, "Scanning interfaces");
kif_last_shot = now;
kif_do_scan(p);
}
static void
kif_force_scan(void)
{
if (kif_proto && kif_last_shot + 2 < now)
{
kif_scan(kif_scan_timer);
tm_start(kif_scan_timer, ((struct kif_config *) kif_proto->p.cf)->scan_time);
}
}
void
kif_request_scan(void)
{
if (kif_proto && kif_scan_timer->expires > now)
tm_start(kif_scan_timer, 1);
}
static inline int
prefer_addr(struct ifa *a, struct ifa *b)
{
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int sa = a->scope > SCOPE_LINK;
int sb = b->scope > SCOPE_LINK;
if (sa < sb)
return 0;
else if (sa > sb)
return 1;
else
return ipa_compare(a->ip, b->ip) < 0;
}
static inline struct ifa *
find_preferred_ifa(struct iface *i, ip_addr prefix, ip_addr mask)
{
struct ifa *a, *b = NULL;
WALK_LIST(a, i->addrs)
{
if (!(a->flags & IA_SECONDARY) &&
ipa_equal(ipa_and(a->ip, mask), prefix) &&
2012-08-29 18:42:49 +08:00
(!b || prefer_addr(a, b)))
b = a;
}
return b;
}
struct ifa *
kif_choose_primary(struct iface *i)
{
struct kif_config *cf = (struct kif_config *) (kif_proto->p.cf);
struct kif_primary_item *it;
struct ifa *a;
WALK_LIST(it, cf->primary)
{
if (!it->pattern || patmatch(it->pattern, i->name))
if (a = find_preferred_ifa(i, it->prefix, ipa_mkmask(it->pxlen)))
return a;
}
if (a = kif_get_primary_ip(i))
return a;
return find_preferred_ifa(i, IPA_NONE, IPA_NONE);
}
static struct proto *
kif_init(struct proto_config *c)
{
struct kif_proto *p = proto_new(c, sizeof(struct kif_proto));
kif_sys_init(p);
return &p->p;
}
static int
kif_start(struct proto *P)
{
struct kif_proto *p = (struct kif_proto *) P;
kif_proto = p;
kif_sys_start(p);
/* Start periodic interface scanning */
kif_scan_timer = tm_new(P->pool);
kif_scan_timer->hook = kif_scan;
kif_scan_timer->data = p;
kif_scan_timer->recurrent = KIF_CF->scan_time;
kif_scan(kif_scan_timer);
tm_start(kif_scan_timer, KIF_CF->scan_time);
return PS_UP;
}
static int
kif_shutdown(struct proto *P)
{
struct kif_proto *p = (struct kif_proto *) P;
tm_stop(kif_scan_timer);
kif_sys_shutdown(p);
kif_proto = NULL;
return PS_DOWN;
}
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static int
kif_reconfigure(struct proto *p, struct proto_config *new)
{
struct kif_config *o = (struct kif_config *) p->cf;
struct kif_config *n = (struct kif_config *) new;
if (!kif_sys_reconfigure((struct kif_proto *) p, n, o))
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return 0;
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if (o->scan_time != n->scan_time)
{
tm_stop(kif_scan_timer);
kif_scan_timer->recurrent = n->scan_time;
kif_scan(kif_scan_timer);
tm_start(kif_scan_timer, n->scan_time);
}
if (!EMPTY_LIST(o->primary) || !EMPTY_LIST(n->primary))
{
/* This is hack, we have to update a configuration
* to the new value just now, because it is used
* for recalculation of primary addresses.
*/
p->cf = new;
ifa_recalc_all_primary_addresses();
}
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return 1;
}
static void
kif_preconfig(struct protocol *P UNUSED, struct config *c)
{
kif_cf = NULL;
kif_sys_preconfig(c);
}
struct proto_config *
kif_init_config(int class)
{
if (kif_cf)
cf_error("Kernel device protocol already defined");
kif_cf = (struct kif_config *) proto_config_new(&proto_unix_iface, class);
kif_cf->scan_time = 60;
init_list(&kif_cf->primary);
kif_sys_init_config(kif_cf);
return (struct proto_config *) kif_cf;
}
static void
kif_copy_config(struct proto_config *dest, struct proto_config *src)
{
struct kif_config *d = (struct kif_config *) dest;
struct kif_config *s = (struct kif_config *) src;
/* Shallow copy of everything (just scan_time currently) */
proto_copy_rest(dest, src, sizeof(struct kif_config));
/* Copy primary addr list */
cfg_copy_list(&d->primary, &s->primary, sizeof(struct kif_primary_item));
/* Fix sysdep parts */
kif_sys_copy_config(d, s);
}
struct protocol proto_unix_iface = {
.name = "Device",
.template = "device%d",
.preference = DEF_PREF_DIRECT,
.config_size = sizeof(struct kif_config),
.preconfig = kif_preconfig,
.init = kif_init,
.start = kif_start,
.shutdown = kif_shutdown,
.reconfigure = kif_reconfigure,
.copy_config = kif_copy_config
};
/*
* Tracing of routes
*/
static inline void
krt_trace_in(struct krt_proto *p, rte *e, char *msg)
{
if (p->p.debug & D_PACKETS)
log(L_TRACE "%s: %N: %s", p->p.name, e->net->n.addr, msg);
}
static inline void
krt_trace_in_rl(struct tbf *f, struct krt_proto *p, rte *e, char *msg)
{
if (p->p.debug & D_PACKETS)
log_rl(f, L_TRACE "%s: %N: %s", p->p.name, e->net->n.addr, msg);
}
/*
* Inherited Routes
*/
#ifdef KRT_ALLOW_LEARN
static struct tbf rl_alien = TBF_DEFAULT_LOG_LIMITS;
/*
* krt_same_key() specifies what (aside from the net) is the key in
* kernel routing tables. It should be OS-dependent, this is for
* Linux. It is important for asynchronous alien updates, because a
* positive update is implicitly a negative one for any old route with
* the same key.
*/
static inline int
krt_same_key(rte *a, rte *b)
{
return a->u.krt.metric == b->u.krt.metric;
}
static inline int
krt_uptodate(rte *a, rte *b)
{
if (a->attrs != b->attrs)
return 0;
if (a->u.krt.proto != b->u.krt.proto)
return 0;
return 1;
}
static void
krt_learn_announce_update(struct krt_proto *p, rte *e)
{
net *n = e->net;
rta *aa = rta_clone(e->attrs);
rte *ee = rte_get_temp(aa);
net *nn = net_get(p->p.table, n->n.addr);
ee->net = nn;
ee->pflags = 0;
ee->pref = p->p.preference;
ee->u.krt = e->u.krt;
rte_update(&p->p, nn, ee);
}
static void
krt_learn_announce_delete(struct krt_proto *p, net *n)
{
n = net_find(p->p.table, n->n.addr);
rte_update(&p->p, n, NULL);
}
/* Called when alien route is discovered during scan */
static void
krt_learn_scan(struct krt_proto *p, rte *e)
{
net *n0 = e->net;
net *n = net_get(&p->krt_table, n0->n.addr);
rte *m, **mm;
e->attrs = rta_lookup(e->attrs);
for(mm=&n->routes; m = *mm; mm=&m->next)
if (krt_same_key(m, e))
break;
if (m)
{
if (krt_uptodate(m, e))
{
krt_trace_in_rl(&rl_alien, p, e, "[alien] seen");
rte_free(e);
m->u.krt.seen = 1;
}
else
{
krt_trace_in(p, e, "[alien] updated");
*mm = m->next;
rte_free(m);
m = NULL;
}
}
else
krt_trace_in(p, e, "[alien] created");
if (!m)
{
e->next = n->routes;
n->routes = e;
e->u.krt.seen = 1;
}
}
static void
krt_learn_prune(struct krt_proto *p)
{
struct fib *fib = &p->krt_table.fib;
struct fib_iterator fit;
KRT_TRACE(p, D_EVENTS, "Pruning inherited routes");
FIB_ITERATE_INIT(&fit, fib);
again:
FIB_ITERATE_START(fib, &fit, f)
{
net *n = (net *) f;
rte *e, **ee, *best, **pbest, *old_best;
old_best = n->routes;
best = NULL;
pbest = NULL;
ee = &n->routes;
while (e = *ee)
{
if (!e->u.krt.seen)
{
*ee = e->next;
rte_free(e);
continue;
}
if (!best || best->u.krt.metric > e->u.krt.metric)
{
best = e;
pbest = ee;
}
e->u.krt.seen = 0;
ee = &e->next;
}
if (!n->routes)
{
DBG("%I/%d: deleting\n", n->n.prefix, n->n.pxlen);
if (old_best)
{
krt_learn_announce_delete(p, n);
n->n.flags &= ~KRF_INSTALLED;
}
FIB_ITERATE_PUT(&fit, f);
fib_delete(fib, f);
goto again;
}
*pbest = best->next;
best->next = n->routes;
n->routes = best;
if (best != old_best || !(n->n.flags & KRF_INSTALLED) || p->reload)
{
DBG("%I/%d: announcing (metric=%d)\n", n->n.prefix, n->n.pxlen, best->u.krt.metric);
krt_learn_announce_update(p, best);
n->n.flags |= KRF_INSTALLED;
}
else
DBG("%I/%d: uptodate (metric=%d)\n", n->n.prefix, n->n.pxlen, best->u.krt.metric);
}
FIB_ITERATE_END(f);
p->reload = 0;
}
static void
krt_learn_async(struct krt_proto *p, rte *e, int new)
{
net *n0 = e->net;
net *n = net_get(&p->krt_table, n0->n.addr);
rte *g, **gg, *best, **bestp, *old_best;
e->attrs = rta_lookup(e->attrs);
old_best = n->routes;
for(gg=&n->routes; g = *gg; gg = &g->next)
if (krt_same_key(g, e))
break;
if (new)
{
if (g)
{
if (krt_uptodate(g, e))
{
krt_trace_in(p, e, "[alien async] same");
rte_free(e);
return;
}
krt_trace_in(p, e, "[alien async] updated");
*gg = g->next;
rte_free(g);
}
else
krt_trace_in(p, e, "[alien async] created");
e->next = n->routes;
n->routes = e;
}
else if (!g)
{
krt_trace_in(p, e, "[alien async] delete failed");
rte_free(e);
return;
}
else
{
krt_trace_in(p, e, "[alien async] removed");
*gg = g->next;
rte_free(e);
rte_free(g);
}
best = n->routes;
bestp = &n->routes;
for(gg=&n->routes; g=*gg; gg=&g->next)
if (best->u.krt.metric > g->u.krt.metric)
{
best = g;
bestp = gg;
}
if (best)
{
*bestp = best->next;
best->next = n->routes;
n->routes = best;
}
if (best != old_best)
{
DBG("krt_learn_async: distributing change\n");
if (best)
{
krt_learn_announce_update(p, best);
n->n.flags |= KRF_INSTALLED;
}
else
{
n->routes = NULL;
krt_learn_announce_delete(p, n);
n->n.flags &= ~KRF_INSTALLED;
}
}
}
static void
krt_learn_init(struct krt_proto *p)
{
if (KRT_CF->learn)
rt_setup(p->p.pool, &p->krt_table, "Inherited", NULL);
}
static void
krt_dump(struct proto *P)
{
struct krt_proto *p = (struct krt_proto *) P;
if (!KRT_CF->learn)
return;
debug("KRT: Table of inheritable routes\n");
rt_dump(&p->krt_table);
}
static void
krt_dump_attrs(rte *e)
{
debug(" [m=%d,p=%d,t=%d]", e->u.krt.metric, e->u.krt.proto, e->u.krt.type);
}
#endif
/*
* Routes
*/
static void
krt_flush_routes(struct krt_proto *p)
{
struct rtable *t = p->p.table;
KRT_TRACE(p, D_EVENTS, "Flushing kernel routes");
FIB_WALK(&t->fib, f)
{
net *n = (net *) f;
rte *e = n->routes;
if (rte_is_valid(e) && (n->n.flags & KRF_INSTALLED))
{
2012-05-03 20:04:56 +08:00
/* FIXME: this does not work if gw is changed in export filter */
krt_replace_rte(p, e->net, NULL, e, NULL);
n->n.flags &= ~KRF_INSTALLED;
}
}
FIB_WALK_END;
}
static struct rte *
krt_export_net(struct krt_proto *p, net *net, rte **rt_free, ea_list **tmpa)
{
struct announce_hook *ah = p->p.main_ahook;
struct filter *filter = ah->out_filter;
rte *rt;
if (p->p.accept_ra_types == RA_MERGED)
return rt_export_merged(ah, net, rt_free, tmpa, 1);
rt = net->routes;
*rt_free = NULL;
if (!rte_is_valid(rt))
return NULL;
if (filter == FILTER_REJECT)
return NULL;
struct proto *src = rt->attrs->src->proto;
*tmpa = src->make_tmp_attrs ? src->make_tmp_attrs(rt, krt_filter_lp) : NULL;
/* We could run krt_import_control() here, but it is already handled by KRF_INSTALLED */
if (filter == FILTER_ACCEPT)
goto accept;
if (f_run(filter, &rt, tmpa, krt_filter_lp, FF_FORCE_TMPATTR) > F_ACCEPT)
goto reject;
accept:
if (rt != net->routes)
*rt_free = rt;
return rt;
reject:
if (rt != net->routes)
rte_free(rt);
return NULL;
}
static int
krt_same_dest(rte *k, rte *e)
{
rta *ka = k->attrs, *ea = e->attrs;
if (ka->dest != ea->dest)
return 0;
switch (ka->dest)
{
case RTD_ROUTER:
return ipa_equal(ka->gw, ea->gw);
case RTD_DEVICE:
return !strcmp(ka->iface->name, ea->iface->name);
case RTD_MULTIPATH:
return mpnh_same(ka->nexthops, ea->nexthops);
default:
return 1;
}
}
/*
* This gets called back when the low-level scanning code discovers a route.
* We expect that the route is a temporary rte and its attributes are uncached.
*/
void
krt_got_route(struct krt_proto *p, rte *e)
{
net *net = e->net;
int verdict;
#ifdef KRT_ALLOW_LEARN
switch (e->u.krt.src)
{
case KRT_SRC_KERNEL:
verdict = KRF_IGNORE;
goto sentenced;
case KRT_SRC_REDIRECT:
verdict = KRF_DELETE;
goto sentenced;
case KRT_SRC_ALIEN:
if (KRT_CF->learn)
krt_learn_scan(p, e);
else
{
krt_trace_in_rl(&rl_alien, p, e, "[alien] ignored");
rte_free(e);
}
return;
}
#endif
/* The rest is for KRT_SRC_BIRD (or KRT_SRC_UNKNOWN) */
if (net->n.flags & KRF_VERDICT_MASK)
{
/* Route to this destination was already seen. Strange, but it happens... */
krt_trace_in(p, e, "already seen");
rte_free(e);
return;
}
if (!p->ready)
{
/* We wait for the initial feed to have correct KRF_INSTALLED flag */
verdict = KRF_IGNORE;
goto sentenced;
}
if (net->n.flags & KRF_INSTALLED)
{
rte *new, *rt_free;
ea_list *tmpa;
new = krt_export_net(p, net, &rt_free, &tmpa);
/* TODO: There also may be changes in route eattrs, we ignore that for now. */
if (!new)
verdict = KRF_DELETE;
else if ((net->n.flags & KRF_SYNC_ERROR) || !krt_same_dest(e, new))
verdict = KRF_UPDATE;
else
verdict = KRF_SEEN;
if (rt_free)
rte_free(rt_free);
lp_flush(krt_filter_lp);
}
else
verdict = KRF_DELETE;
sentenced:
krt_trace_in(p, e, ((char *[]) { "?", "seen", "will be updated", "will be removed", "ignored" }) [verdict]);
net->n.flags = (net->n.flags & ~KRF_VERDICT_MASK) | verdict;
if (verdict == KRF_UPDATE || verdict == KRF_DELETE)
{
/* Get a cached copy of attributes and temporarily link the route */
rta *a = e->attrs;
a->source = RTS_DUMMY;
e->attrs = rta_lookup(a);
e->next = net->routes;
net->routes = e;
}
else
rte_free(e);
}
static void
krt_prune(struct krt_proto *p)
{
struct rtable *t = p->p.table;
KRT_TRACE(p, D_EVENTS, "Pruning table %s", t->name);
FIB_WALK(&t->fib, f)
{
net *n = (net *) f;
int verdict = f->flags & KRF_VERDICT_MASK;
rte *new, *old, *rt_free = NULL;
ea_list *tmpa = NULL;
if (verdict == KRF_UPDATE || verdict == KRF_DELETE)
{
/* Get a dummy route from krt_got_route() */
old = n->routes;
n->routes = old->next;
}
else
old = NULL;
if (verdict == KRF_CREATE || verdict == KRF_UPDATE)
{
/* We have to run export filter to get proper 'new' route */
new = krt_export_net(p, n, &rt_free, &tmpa);
if (!new)
verdict = (verdict == KRF_CREATE) ? KRF_IGNORE : KRF_DELETE;
else
tmpa = ea_append(tmpa, new->attrs->eattrs);
}
else
new = NULL;
switch (verdict)
{
case KRF_CREATE:
if (new && (f->flags & KRF_INSTALLED))
{
krt_trace_in(p, new, "reinstalling");
krt_replace_rte(p, n, new, NULL, tmpa);
}
break;
case KRF_SEEN:
case KRF_IGNORE:
/* Nothing happens */
break;
case KRF_UPDATE:
krt_trace_in(p, new, "updating");
krt_replace_rte(p, n, new, old, tmpa);
break;
case KRF_DELETE:
krt_trace_in(p, old, "deleting");
krt_replace_rte(p, n, NULL, old, NULL);
break;
default:
bug("krt_prune: invalid route status");
}
if (old)
rte_free(old);
if (rt_free)
rte_free(rt_free);
lp_flush(krt_filter_lp);
f->flags &= ~KRF_VERDICT_MASK;
}
FIB_WALK_END;
#ifdef KRT_ALLOW_LEARN
if (KRT_CF->learn)
krt_learn_prune(p);
#endif
if (p->ready)
p->initialized = 1;
}
void
krt_got_route_async(struct krt_proto *p, rte *e, int new)
{
net *net = e->net;
switch (e->u.krt.src)
{
case KRT_SRC_BIRD:
ASSERT(0); /* Should be filtered by the back end */
case KRT_SRC_REDIRECT:
if (new)
{
krt_trace_in(p, e, "[redirect] deleting");
krt_replace_rte(p, net, NULL, e, NULL);
}
/* If !new, it is probably echo of our deletion */
break;
#ifdef KRT_ALLOW_LEARN
case KRT_SRC_ALIEN:
if (KRT_CF->learn)
{
krt_learn_async(p, e, new);
return;
}
#endif
}
rte_free(e);
}
/*
* Periodic scanning
*/
2013-06-30 04:55:41 +08:00
#ifdef CONFIG_ALL_TABLES_AT_ONCE
static timer *krt_scan_timer;
static int krt_scan_count;
static void
krt_scan(timer *t UNUSED)
{
struct krt_proto *p;
kif_force_scan();
2013-06-30 04:55:41 +08:00
/* We need some node to decide whether to print the debug messages or not */
p = SKIP_BACK(struct krt_proto, krt_node, HEAD(krt_proto_list));
KRT_TRACE(p, D_EVENTS, "Scanning routing table");
krt_do_scan(NULL);
void *q;
WALK_LIST(q, krt_proto_list)
{
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p = SKIP_BACK(struct krt_proto, krt_node, q);
krt_prune(p);
}
}
static void
krt_scan_timer_start(struct krt_proto *p)
{
if (!krt_scan_count)
krt_scan_timer = tm_new_set(krt_pool, krt_scan, NULL, 0, KRT_CF->scan_time);
krt_scan_count++;
tm_start(krt_scan_timer, 1);
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}
static void
krt_scan_timer_stop(struct krt_proto *p)
{
krt_scan_count--;
if (!krt_scan_count)
{
rfree(krt_scan_timer);
krt_scan_timer = NULL;
}
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}
static void
krt_scan_timer_kick(struct krt_proto *p UNUSED)
{
tm_start(krt_scan_timer, 0);
}
#else
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static void
krt_scan(timer *t)
{
struct krt_proto *p = t->data;
kif_force_scan();
KRT_TRACE(p, D_EVENTS, "Scanning routing table");
krt_do_scan(p);
krt_prune(p);
}
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static void
krt_scan_timer_start(struct krt_proto *p)
{
p->scan_timer = tm_new_set(p->p.pool, krt_scan, p, 0, KRT_CF->scan_time);
tm_start(p->scan_timer, 1);
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}
static void
krt_scan_timer_stop(struct krt_proto *p)
{
tm_stop(p->scan_timer);
}
static void
krt_scan_timer_kick(struct krt_proto *p)
{
tm_start(p->scan_timer, 0);
}
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#endif
/*
* Updates
*/
static struct ea_list *
krt_make_tmp_attrs(rte *rt, struct linpool *pool)
{
struct ea_list *l = lp_alloc(pool, sizeof(struct ea_list) + 2 * sizeof(eattr));
l->next = NULL;
l->flags = EALF_SORTED;
l->count = 2;
l->attrs[0].id = EA_KRT_SOURCE;
l->attrs[0].flags = 0;
l->attrs[0].type = EAF_TYPE_INT | EAF_TEMP;
l->attrs[0].u.data = rt->u.krt.proto;
l->attrs[1].id = EA_KRT_METRIC;
l->attrs[1].flags = 0;
l->attrs[1].type = EAF_TYPE_INT | EAF_TEMP;
l->attrs[1].u.data = rt->u.krt.metric;
return l;
}
static void
krt_store_tmp_attrs(rte *rt, struct ea_list *attrs)
{
/* EA_KRT_SOURCE is read-only */
rt->u.krt.metric = ea_get_int(attrs, EA_KRT_METRIC, 0);
}
static int
krt_import_control(struct proto *P, rte **new, ea_list **attrs, struct linpool *pool)
{
struct krt_proto *p = (struct krt_proto *) P;
rte *e = *new;
if (e->attrs->src->proto == P)
{
#ifdef CONFIG_SINGLE_ROUTE
/*
* Implicit withdraw - when the imported kernel route becomes the best one,
* we know that the previous one exported to the kernel was already removed,
* but if we processed the update as usual, we would send withdraw to the
* kernel, which would remove the new imported route instead.
*
* We will remove KRT_INSTALLED flag, which stops such withdraw to be
* processed in krt_rt_notify() and krt_replace_rte().
*/
if (e == e->net->routes)
e->net->n.flags &= ~KRF_INSTALLED;
#endif
return -1;
}
if (!KRT_CF->devroutes &&
(e->attrs->dest == RTD_DEVICE) &&
(e->attrs->source != RTS_STATIC_DEVICE))
return -1;
if (!krt_capable(e))
return -1;
return 0;
}
static void
krt_rt_notify(struct proto *P, struct rtable *table UNUSED, net *net,
rte *new, rte *old, struct ea_list *eattrs)
{
struct krt_proto *p = (struct krt_proto *) P;
if (config->shutdown)
return;
if (!(net->n.flags & KRF_INSTALLED))
old = NULL;
if (new)
net->n.flags |= KRF_INSTALLED;
else
net->n.flags &= ~KRF_INSTALLED;
if (p->initialized) /* Before first scan we don't touch the routes */
krt_replace_rte(p, net, new, old, eattrs);
}
static void
krt_if_notify(struct proto *P, uint flags, struct iface *iface UNUSED)
{
struct krt_proto *p = (struct krt_proto *) P;
/*
* When interface went down, we should remove routes to it. In the ideal world,
* OS kernel would send us route removal notifications in such cases, but we
* cannot rely on it as it is often not true. E.g. Linux kernel removes related
* routes when an interface went down, but it does not notify userspace about
* that. To be sure, we just schedule a scan to ensure synchronization.
*/
if ((flags & IF_CHANGE_DOWN) && KRT_CF->learn)
krt_scan_timer_kick(p);
}
static int
krt_reload_routes(struct proto *P)
{
struct krt_proto *p = (struct krt_proto *) P;
/* Although we keep learned routes in krt_table, we rather schedule a scan */
if (KRT_CF->learn)
{
p->reload = 1;
krt_scan_timer_kick(p);
}
return 1;
}
static void
krt_feed_end(struct proto *P)
{
struct krt_proto *p = (struct krt_proto *) P;
p->ready = 1;
krt_scan_timer_kick(p);
}
static int
krt_rte_same(rte *a, rte *b)
{
/* src is always KRT_SRC_ALIEN and type is irrelevant */
return (a->u.krt.proto == b->u.krt.proto) && (a->u.krt.metric == b->u.krt.metric);
}
/*
* Protocol glue
*/
struct krt_config *krt_cf;
static struct proto *
krt_init(struct proto_config *C)
{
struct krt_proto *p = proto_new(C, sizeof(struct krt_proto));
struct krt_config *c = (struct krt_config *) C;
p->p.accept_ra_types = c->merge_paths ? RA_MERGED : RA_OPTIMAL;
p->p.merge_limit = c->merge_paths;
p->p.import_control = krt_import_control;
p->p.rt_notify = krt_rt_notify;
p->p.if_notify = krt_if_notify;
p->p.reload_routes = krt_reload_routes;
p->p.feed_end = krt_feed_end;
p->p.make_tmp_attrs = krt_make_tmp_attrs;
p->p.store_tmp_attrs = krt_store_tmp_attrs;
p->p.rte_same = krt_rte_same;
krt_sys_init(p);
return &p->p;
}
static int
krt_start(struct proto *P)
{
struct krt_proto *p = (struct krt_proto *) P;
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add_tail(&krt_proto_list, &p->krt_node);
#ifdef KRT_ALLOW_LEARN
krt_learn_init(p);
#endif
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krt_sys_start(p);
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krt_scan_timer_start(p);
if (P->gr_recovery && KRT_CF->graceful_restart)
P->gr_wait = 1;
return PS_UP;
}
static int
krt_shutdown(struct proto *P)
{
struct krt_proto *p = (struct krt_proto *) P;
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krt_scan_timer_stop(p);
/* FIXME we should flush routes even when persist during reconfiguration */
if (p->initialized && !KRT_CF->persist)
krt_flush_routes(p);
p->ready = 0;
p->initialized = 0;
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krt_sys_shutdown(p);
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rem_node(&p->krt_node);
return PS_DOWN;
}
static int
krt_reconfigure(struct proto *p, struct proto_config *new)
{
struct krt_config *o = (struct krt_config *) p->cf;
struct krt_config *n = (struct krt_config *) new;
if (!krt_sys_reconfigure((struct krt_proto *) p, n, o))
return 0;
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/* persist, graceful restart need not be the same */
return o->scan_time == n->scan_time && o->learn == n->learn &&
o->devroutes == n->devroutes && o->merge_paths == n->merge_paths;
}
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static void
krt_preconfig(struct protocol *P UNUSED, struct config *c)
{
krt_cf = NULL;
krt_sys_preconfig(c);
}
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static void
krt_postconfig(struct proto_config *C)
{
struct krt_config *c = (struct krt_config *) C;
#ifdef CONFIG_ALL_TABLES_AT_ONCE
if (krt_cf->scan_time != c->scan_time)
cf_error("All kernel syncers must use the same table scan interval");
#endif
if (C->table->krt_attached)
cf_error("Kernel syncer (%s) already attached to table %s", C->table->krt_attached->name, C->table->name);
C->table->krt_attached = C;
krt_sys_postconfig(c);
}
struct proto_config *
krt_init_config(int class)
{
#ifndef CONFIG_MULTIPLE_TABLES
if (krt_cf)
cf_error("Kernel protocol already defined");
#endif
krt_cf = (struct krt_config *) proto_config_new(&proto_unix_kernel, class);
krt_cf->scan_time = 60;
krt_sys_init_config(krt_cf);
return (struct proto_config *) krt_cf;
}
static void
krt_copy_config(struct proto_config *dest, struct proto_config *src)
{
struct krt_config *d = (struct krt_config *) dest;
struct krt_config *s = (struct krt_config *) src;
/* Shallow copy of everything */
proto_copy_rest(dest, src, sizeof(struct krt_config));
/* Fix sysdep parts */
krt_sys_copy_config(d, s);
}
static int
krt_get_attr(eattr *a, byte *buf, int buflen)
{
switch (a->id)
{
case EA_KRT_SOURCE:
bsprintf(buf, "source");
return GA_NAME;
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case EA_KRT_METRIC:
bsprintf(buf, "metric");
return GA_NAME;
default:
return krt_sys_get_attr(a, buf, buflen);
}
}
struct protocol proto_unix_kernel = {
.name = "Kernel",
.template = "kernel%d",
.attr_class = EAP_KRT,
.preference = DEF_PREF_INHERITED,
.config_size = sizeof(struct krt_config),
.preconfig = krt_preconfig,
.postconfig = krt_postconfig,
.init = krt_init,
.start = krt_start,
.shutdown = krt_shutdown,
.reconfigure = krt_reconfigure,
.copy_config = krt_copy_config,
.get_attr = krt_get_attr,
#ifdef KRT_ALLOW_LEARN
.dump = krt_dump,
.dump_attrs = krt_dump_attrs,
#endif
};