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/* $OpenBSD: rde_filter.c,v 1.21 2004/10/08 16:36:42 claudio Exp $ */
/*
* Copyright (c) 2004 Claudio Jeker <claudio@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <sys/queue.h>
#include <string.h>
#include "bgpd.h"
#include "rde.h"
extern struct filter_head *rules_l; /* XXX ugly */
int rde_filter_match(struct filter_rule *, struct rde_aspath *,
struct bgpd_addr *, u_int8_t);
enum filter_actions
rde_filter(struct rde_peer *peer, struct rde_aspath *asp,
struct bgpd_addr *prefix, u_int8_t prefixlen, enum directions dir)
{
struct filter_rule *f;
enum filter_actions action = ACTION_ALLOW; /* default allow */
TAILQ_FOREACH(f, rules_l, entry) {
if (dir != f->dir)
continue;
if (f->peer.groupid != 0 &&
f->peer.groupid != peer->conf.groupid)
continue;
if (f->peer.peerid != 0 &&
f->peer.peerid != peer->conf.id)
continue;
if (rde_filter_match(f, asp, prefix, prefixlen)) {
if (asp != NULL)
rde_apply_set(asp, &f->set, prefix->af,
asp->peer, dir);
if (f->action != ACTION_NONE)
action = f->action;
if (f->quick)
return (action);
}
}
return (action);
}
void
rde_apply_set(struct rde_aspath *asp, struct filter_set *set, sa_family_t af,
struct rde_peer *peer, enum directions dir)
{
struct aspath *new;
u_int16_t as;
u_int8_t prepend;
if (asp == NULL)
return;
if (set->flags & SET_PREPEND_SELF && dir != DIR_DEFAULT_IN) {
/* don't apply if this is a incoming default override */
as = rde_local_as();
prepend = set->prepend_self;
new = aspath_prepend(asp->aspath, as, prepend);
aspath_put(asp->aspath);
asp->aspath = new;
}
if (dir == DIR_DEFAULT_OUT)
/*
* default outgoing overrides are only allowed to
* set prepend-self
*/
return;
if (set->flags & SET_PREPEND_PEER) {
as = peer->conf.remote_as;
prepend = set->prepend_peer;
new = aspath_prepend(asp->aspath, as, prepend);
aspath_put(asp->aspath);
asp->aspath = new;
}
if (set->flags & SET_LOCALPREF)
asp->lpref = set->localpref;
if (set->flags & SET_MED) {
asp->flags |= F_ATTR_MED | F_ATTR_MED_ANNOUNCE;
asp->med = set->med;
}
nexthop_modify(asp, &set->nexthop, set->flags, af);
if (set->flags & SET_PFTABLE)
strlcpy(asp->pftable, set->pftable, sizeof(asp->pftable));
if (set->flags & SET_COMMUNITY) {
struct attr *a;
if ((a = attr_optget(asp, ATTR_COMMUNITIES)) == NULL) {
attr_optadd(asp, ATTR_OPTIONAL|ATTR_TRANSITIVE,
ATTR_COMMUNITIES, NULL, 0);
if ((a = attr_optget(asp, ATTR_COMMUNITIES)) == NULL)
fatalx("internal community bug");
}
community_set(a, set->community.as, set->community.type);
}
}
int
rde_filter_match(struct filter_rule *f, struct rde_aspath *asp,
struct bgpd_addr *prefix, u_int8_t plen)
{
if (asp != NULL && f->match.as.type != AS_NONE)
if (aspath_match(asp->aspath, f->match.as.type,
f->match.as.as) == 0)
return (0);
if (asp != NULL && f->match.community.as != 0)
if (rde_filter_community(asp, f->match.community.as,
f->match.community.type) == 0)
return (0);
if (f->match.prefix.addr.af != 0 &&
f->match.prefix.addr.af == prefix->af) {
if (prefix_compare(prefix, &f->match.prefix.addr,
f->match.prefix.len))
return (0);
/* test prefixlen stuff too */
switch (f->match.prefixlen.op) {
case OP_NONE:
/* perfect match */
return (plen == f->match.prefix.len);
case OP_RANGE:
return ((plen >= f->match.prefixlen.len_min) &&
(plen <= f->match.prefixlen.len_max));
case OP_XRANGE:
return ((plen < f->match.prefixlen.len_min) ||
(plen > f->match.prefixlen.len_max));
case OP_EQ:
return (plen == f->match.prefixlen.len_min);
case OP_NE:
return (plen != f->match.prefixlen.len_min);
case OP_LE:
return (plen <= f->match.prefixlen.len_min);
case OP_LT:
return (plen < f->match.prefixlen.len_min);
case OP_GE:
return (plen >= f->match.prefixlen.len_min);
case OP_GT:
return (plen > f->match.prefixlen.len_min);
}
/* NOTREACHED */
} else if (f->match.prefixlen.op != OP_NONE) {
/* only prefixlen without a prefix */
if (f->match.prefixlen.af != prefix->af)
/* don't use IPv4 rules for IPv6 and vice versa */
return (0);
switch (f->match.prefixlen.op) {
case OP_NONE:
fatalx("internal filter bug");
case OP_RANGE:
return ((plen >= f->match.prefixlen.len_min) &&
(plen <= f->match.prefixlen.len_max));
case OP_XRANGE:
return ((plen < f->match.prefixlen.len_min) ||
(plen > f->match.prefixlen.len_max));
case OP_EQ:
return (plen == f->match.prefixlen.len_min);
case OP_NE:
return (plen != f->match.prefixlen.len_min);
case OP_LE:
return (plen <= f->match.prefixlen.len_min);
case OP_LT:
return (plen < f->match.prefixlen.len_min);
case OP_GE:
return (plen >= f->match.prefixlen.len_min);
case OP_GT:
return (plen > f->match.prefixlen.len_min);
}
/* NOTREACHED */
}
/* matched somewhen or is anymatch rule */
return (1);
}
int
rde_filter_community(struct rde_aspath *asp, int as, int type)
{
struct attr *a;
a = attr_optget(asp, ATTR_COMMUNITIES);
if (a == NULL)
/* no communities, no match */
return (0);
return (community_match(a->data, a->len, as, type));
}
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