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bgp_attr.c
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/* BGP attributes management routines.
* Copyright (C) 1996, 97, 98, 1999 Kunihiro Ishiguro
*
* This file is part of GNU Zebra.
*
* GNU Zebra is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2, or (at your option) any
* later version.
*
* GNU Zebra is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; see the file COPYING; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <zebra.h>
#include "linklist.h"
#include "prefix.h"
#include "memory.h"
#include "vector.h"
#include "stream.h"
#include "log.h"
#include "hash.h"
#include "jhash.h"
#include "queue.h"
#include "table.h"
#include "filter.h"
#include "command.h"
#include "bgpd/bgpd.h"
#include "bgpd/bgp_attr.h"
#include "bgpd/bgp_route.h"
#include "bgpd/bgp_aspath.h"
#include "bgpd/bgp_community.h"
#include "bgpd/bgp_debug.h"
#include "bgpd/bgp_errors.h"
#include "bgpd/bgp_label.h"
#include "bgpd/bgp_packet.h"
#include "bgpd/bgp_ecommunity.h"
#include "bgpd/bgp_lcommunity.h"
#include "bgpd/bgp_updgrp.h"
#include "bgpd/bgp_encap_types.h"
#if ENABLE_BGP_VNC
#include "bgpd/rfapi/bgp_rfapi_cfg.h"
#include "bgp_encap_types.h"
#include "bgp_vnc_types.h"
#endif
#include "bgp_encap_types.h"
#include "bgp_evpn.h"
#include "bgp_flowspec_private.h"
/* Attribute strings for logging. */
static const struct message attr_str[] = {
{BGP_ATTR_ORIGIN, "ORIGIN"},
{BGP_ATTR_AS_PATH, "AS_PATH"},
{BGP_ATTR_NEXT_HOP, "NEXT_HOP"},
{BGP_ATTR_MULTI_EXIT_DISC, "MULTI_EXIT_DISC"},
{BGP_ATTR_LOCAL_PREF, "LOCAL_PREF"},
{BGP_ATTR_ATOMIC_AGGREGATE, "ATOMIC_AGGREGATE"},
{BGP_ATTR_AGGREGATOR, "AGGREGATOR"},
{BGP_ATTR_COMMUNITIES, "COMMUNITY"},
{BGP_ATTR_ORIGINATOR_ID, "ORIGINATOR_ID"},
{BGP_ATTR_CLUSTER_LIST, "CLUSTER_LIST"},
{BGP_ATTR_DPA, "DPA"},
{BGP_ATTR_ADVERTISER, "ADVERTISER"},
{BGP_ATTR_RCID_PATH, "RCID_PATH"},
{BGP_ATTR_MP_REACH_NLRI, "MP_REACH_NLRI"},
{BGP_ATTR_MP_UNREACH_NLRI, "MP_UNREACH_NLRI"},
{BGP_ATTR_EXT_COMMUNITIES, "EXT_COMMUNITIES"},
{BGP_ATTR_AS4_PATH, "AS4_PATH"},
{BGP_ATTR_AS4_AGGREGATOR, "AS4_AGGREGATOR"},
{BGP_ATTR_AS_PATHLIMIT, "AS_PATHLIMIT"},
{BGP_ATTR_PMSI_TUNNEL, "PMSI_TUNNEL_ATTRIBUTE"},
{BGP_ATTR_ENCAP, "ENCAP"},
#if ENABLE_BGP_VNC_ATTR
{BGP_ATTR_VNC, "VNC"},
#endif
{BGP_ATTR_LARGE_COMMUNITIES, "LARGE_COMMUNITY"},
{BGP_ATTR_PREFIX_SID, "PREFIX_SID"},
{0}};
static const struct message attr_flag_str[] = {
{BGP_ATTR_FLAG_OPTIONAL, "Optional"},
{BGP_ATTR_FLAG_TRANS, "Transitive"},
{BGP_ATTR_FLAG_PARTIAL, "Partial"},
/* bgp_attr_flags_diagnose() relies on this bit being last in
this list */
{BGP_ATTR_FLAG_EXTLEN, "Extended Length"},
{0}};
static struct hash *cluster_hash;
static void *cluster_hash_alloc(void *p)
{
const struct cluster_list *val = (const struct cluster_list *)p;
struct cluster_list *cluster;
cluster = XMALLOC(MTYPE_CLUSTER, sizeof(struct cluster_list));
cluster->length = val->length;
if (cluster->length) {
cluster->list = XMALLOC(MTYPE_CLUSTER_VAL, val->length);
memcpy(cluster->list, val->list, val->length);
} else
cluster->list = NULL;
cluster->refcnt = 0;
return cluster;
}
/* Cluster list related functions. */
static struct cluster_list *cluster_parse(struct in_addr *pnt, int length)
{
struct cluster_list tmp;
struct cluster_list *cluster;
tmp.length = length;
tmp.list = pnt;
cluster = hash_get(cluster_hash, &tmp, cluster_hash_alloc);
cluster->refcnt++;
return cluster;
}
int cluster_loop_check(struct cluster_list *cluster, struct in_addr originator)
{
int i;
for (i = 0; i < cluster->length / 4; i++)
if (cluster->list[i].s_addr == originator.s_addr)
return 1;
return 0;
}
static unsigned int cluster_hash_key_make(void *p)
{
const struct cluster_list *cluster = p;
return jhash(cluster->list, cluster->length, 0);
}
static bool cluster_hash_cmp(const void *p1, const void *p2)
{
const struct cluster_list *cluster1 = p1;
const struct cluster_list *cluster2 = p2;
return (cluster1->length == cluster2->length
&& memcmp(cluster1->list, cluster2->list, cluster1->length)
== 0);
}
static void cluster_free(struct cluster_list *cluster)
{
if (cluster->list)
XFREE(MTYPE_CLUSTER_VAL, cluster->list);
XFREE(MTYPE_CLUSTER, cluster);
}
static struct cluster_list *cluster_intern(struct cluster_list *cluster)
{
struct cluster_list *find;
find = hash_get(cluster_hash, cluster, cluster_hash_alloc);
find->refcnt++;
return find;
}
void cluster_unintern(struct cluster_list *cluster)
{
if (cluster->refcnt)
cluster->refcnt--;
if (cluster->refcnt == 0) {
hash_release(cluster_hash, cluster);
cluster_free(cluster);
}
}
static void cluster_init(void)
{
cluster_hash = hash_create(cluster_hash_key_make, cluster_hash_cmp,
"BGP Cluster");
}
static void cluster_finish(void)
{
hash_clean(cluster_hash, (void (*)(void *))cluster_free);
hash_free(cluster_hash);
cluster_hash = NULL;
}
static struct hash *encap_hash = NULL;
#if ENABLE_BGP_VNC
static struct hash *vnc_hash = NULL;
#endif
struct bgp_attr_encap_subtlv *encap_tlv_dup(struct bgp_attr_encap_subtlv *orig)
{
struct bgp_attr_encap_subtlv *new;
struct bgp_attr_encap_subtlv *tail;
struct bgp_attr_encap_subtlv *p;
for (p = orig, tail = new = NULL; p; p = p->next) {
int size = sizeof(struct bgp_attr_encap_subtlv) + p->length;
if (tail) {
tail->next = XCALLOC(MTYPE_ENCAP_TLV, size);
tail = tail->next;
} else {
tail = new = XCALLOC(MTYPE_ENCAP_TLV, size);
}
assert(tail);
memcpy(tail, p, size);
tail->next = NULL;
}
return new;
}
static void encap_free(struct bgp_attr_encap_subtlv *p)
{
struct bgp_attr_encap_subtlv *next;
while (p) {
next = p->next;
p->next = NULL;
XFREE(MTYPE_ENCAP_TLV, p);
p = next;
}
}
void bgp_attr_flush_encap(struct attr *attr)
{
if (!attr)
return;
if (attr->encap_subtlvs) {
encap_free(attr->encap_subtlvs);
attr->encap_subtlvs = NULL;
}
#if ENABLE_BGP_VNC
if (attr->vnc_subtlvs) {
encap_free(attr->vnc_subtlvs);
attr->vnc_subtlvs = NULL;
}
#endif
}
/*
* Compare encap sub-tlv chains
*
* 1 = equivalent
* 0 = not equivalent
*
* This algorithm could be made faster if needed
*/
static int encap_same(const struct bgp_attr_encap_subtlv *h1,
const struct bgp_attr_encap_subtlv *h2)
{
const struct bgp_attr_encap_subtlv *p;
const struct bgp_attr_encap_subtlv *q;
if (h1 == h2)
return 1;
if (h1 == NULL || h2 == NULL)
return 0;
for (p = h1; p; p = p->next) {
for (q = h2; q; q = q->next) {
if ((p->type == q->type) && (p->length == q->length)
&& !memcmp(p->value, q->value, p->length)) {
break;
}
}
if (!q)
return 0;
}
for (p = h2; p; p = p->next) {
for (q = h1; q; q = q->next) {
if ((p->type == q->type) && (p->length == q->length)
&& !memcmp(p->value, q->value, p->length)) {
break;
}
}
if (!q)
return 0;
}
return 1;
}
static void *encap_hash_alloc(void *p)
{
/* Encap structure is already allocated. */
return p;
}
typedef enum {
ENCAP_SUBTLV_TYPE,
#if ENABLE_BGP_VNC
VNC_SUBTLV_TYPE
#endif
} encap_subtlv_type;
static struct bgp_attr_encap_subtlv *
encap_intern(struct bgp_attr_encap_subtlv *encap, encap_subtlv_type type)
{
struct bgp_attr_encap_subtlv *find;
struct hash *hash = encap_hash;
#if ENABLE_BGP_VNC
if (type == VNC_SUBTLV_TYPE)
hash = vnc_hash;
#endif
find = hash_get(hash, encap, encap_hash_alloc);
if (find != encap)
encap_free(encap);
find->refcnt++;
return find;
}
static void encap_unintern(struct bgp_attr_encap_subtlv **encapp,
encap_subtlv_type type)
{
struct bgp_attr_encap_subtlv *encap = *encapp;
if (encap->refcnt)
encap->refcnt--;
if (encap->refcnt == 0) {
struct hash *hash = encap_hash;
#if ENABLE_BGP_VNC
if (type == VNC_SUBTLV_TYPE)
hash = vnc_hash;
#endif
hash_release(hash, encap);
encap_free(encap);
*encapp = NULL;
}
}
static unsigned int encap_hash_key_make(void *p)
{
const struct bgp_attr_encap_subtlv *encap = p;
return jhash(encap->value, encap->length, 0);
}
static bool encap_hash_cmp(const void *p1, const void *p2)
{
return encap_same((const struct bgp_attr_encap_subtlv *)p1,
(const struct bgp_attr_encap_subtlv *)p2);
}
static void encap_init(void)
{
encap_hash = hash_create(encap_hash_key_make, encap_hash_cmp,
"BGP Encap Hash");
#if ENABLE_BGP_VNC
vnc_hash = hash_create(encap_hash_key_make, encap_hash_cmp,
"BGP VNC Hash");
#endif
}
static void encap_finish(void)
{
hash_clean(encap_hash, (void (*)(void *))encap_free);
hash_free(encap_hash);
encap_hash = NULL;
#if ENABLE_BGP_VNC
hash_clean(vnc_hash, (void (*)(void *))encap_free);
hash_free(vnc_hash);
vnc_hash = NULL;
#endif
}
static bool overlay_index_same(const struct attr *a1, const struct attr *a2)
{
if (!a1 && a2)
return false;
if (!a2 && a1)
return false;
if (!a1 && !a2)
return true;
return !memcmp(&(a1->evpn_overlay), &(a2->evpn_overlay),
sizeof(struct bgp_route_evpn));
}
/* Unknown transit attribute. */
static struct hash *transit_hash;
static void transit_free(struct transit *transit)
{
if (transit->val)
XFREE(MTYPE_TRANSIT_VAL, transit->val);
XFREE(MTYPE_TRANSIT, transit);
}
static void *transit_hash_alloc(void *p)
{
/* Transit structure is already allocated. */
return p;
}
static struct transit *transit_intern(struct transit *transit)
{
struct transit *find;
find = hash_get(transit_hash, transit, transit_hash_alloc);
if (find != transit)
transit_free(transit);
find->refcnt++;
return find;
}
void transit_unintern(struct transit *transit)
{
if (transit->refcnt)
transit->refcnt--;
if (transit->refcnt == 0) {
hash_release(transit_hash, transit);
transit_free(transit);
}
}
static unsigned int transit_hash_key_make(void *p)
{
const struct transit *transit = p;
return jhash(transit->val, transit->length, 0);
}
static bool transit_hash_cmp(const void *p1, const void *p2)
{
const struct transit *transit1 = p1;
const struct transit *transit2 = p2;
return (transit1->length == transit2->length
&& memcmp(transit1->val, transit2->val, transit1->length) == 0);
}
static void transit_init(void)
{
transit_hash = hash_create(transit_hash_key_make, transit_hash_cmp,
"BGP Transit Hash");
}
static void transit_finish(void)
{
hash_clean(transit_hash, (void (*)(void *))transit_free);
hash_free(transit_hash);
transit_hash = NULL;
}
/* Attribute hash routines. */
static struct hash *attrhash;
/* Shallow copy of an attribute
* Though, not so shallow that it doesn't copy the contents
* of the attr_extra pointed to by 'extra'
*/
void bgp_attr_dup(struct attr *new, struct attr *orig)
{
*new = *orig;
}
unsigned long int attr_count(void)
{
return attrhash->count;
}
unsigned long int attr_unknown_count(void)
{
return transit_hash->count;
}
unsigned int attrhash_key_make(void *p)
{
const struct attr *attr = (struct attr *)p;
uint32_t key = 0;
#define MIX(val) key = jhash_1word(val, key)
#define MIX3(a, b, c) key = jhash_3words((a), (b), (c), key)
MIX3(attr->origin, attr->nexthop.s_addr, attr->med);
MIX3(attr->local_pref, attr->aggregator_as,
attr->aggregator_addr.s_addr);
MIX3(attr->weight, attr->mp_nexthop_global_in.s_addr,
attr->originator_id.s_addr);
MIX3(attr->tag, attr->label, attr->label_index);
if (attr->aspath)
MIX(aspath_key_make(attr->aspath));
if (attr->community)
MIX(community_hash_make(attr->community));
if (attr->lcommunity)
MIX(lcommunity_hash_make(attr->lcommunity));
if (attr->ecommunity)
MIX(ecommunity_hash_make(attr->ecommunity));
if (attr->cluster)
MIX(cluster_hash_key_make(attr->cluster));
if (attr->transit)
MIX(transit_hash_key_make(attr->transit));
if (attr->encap_subtlvs)
MIX(encap_hash_key_make(attr->encap_subtlvs));
#if ENABLE_BGP_VNC
if (attr->vnc_subtlvs)
MIX(encap_hash_key_make(attr->vnc_subtlvs));
#endif
MIX(attr->mp_nexthop_len);
key = jhash(attr->mp_nexthop_global.s6_addr, IPV6_MAX_BYTELEN, key);
key = jhash(attr->mp_nexthop_local.s6_addr, IPV6_MAX_BYTELEN, key);
MIX(attr->nh_ifindex);
MIX(attr->nh_lla_ifindex);
return key;
}
bool attrhash_cmp(const void *p1, const void *p2)
{
const struct attr *attr1 = p1;
const struct attr *attr2 = p2;
if (attr1->flag == attr2->flag && attr1->origin == attr2->origin
&& attr1->nexthop.s_addr == attr2->nexthop.s_addr
&& attr1->aspath == attr2->aspath
&& attr1->community == attr2->community && attr1->med == attr2->med
&& attr1->local_pref == attr2->local_pref
&& attr1->rmap_change_flags == attr2->rmap_change_flags) {
if (attr1->aggregator_as == attr2->aggregator_as
&& attr1->aggregator_addr.s_addr
== attr2->aggregator_addr.s_addr
&& attr1->weight == attr2->weight
&& attr1->tag == attr2->tag
&& attr1->label_index == attr2->label_index
&& attr1->mp_nexthop_len == attr2->mp_nexthop_len
&& attr1->ecommunity == attr2->ecommunity
&& attr1->lcommunity == attr2->lcommunity
&& attr1->cluster == attr2->cluster
&& attr1->transit == attr2->transit
&& (attr1->encap_tunneltype == attr2->encap_tunneltype)
&& encap_same(attr1->encap_subtlvs, attr2->encap_subtlvs)
#if ENABLE_BGP_VNC
&& encap_same(attr1->vnc_subtlvs, attr2->vnc_subtlvs)
#endif
&& IPV6_ADDR_SAME(&attr1->mp_nexthop_global,
&attr2->mp_nexthop_global)
&& IPV6_ADDR_SAME(&attr1->mp_nexthop_local,
&attr2->mp_nexthop_local)
&& IPV4_ADDR_SAME(&attr1->mp_nexthop_global_in,
&attr2->mp_nexthop_global_in)
&& IPV4_ADDR_SAME(&attr1->originator_id,
&attr2->originator_id)
&& overlay_index_same(attr1, attr2)
&& attr1->nh_ifindex == attr2->nh_ifindex
&& attr1->nh_lla_ifindex == attr2->nh_lla_ifindex)
return true;
}
return false;
}
static void attrhash_init(void)
{
attrhash =
hash_create(attrhash_key_make, attrhash_cmp, "BGP Attributes");
}
/*
* special for hash_clean below
*/
static void attr_vfree(void *attr)
{
XFREE(MTYPE_ATTR, attr);
}
static void attrhash_finish(void)
{
hash_clean(attrhash, attr_vfree);
hash_free(attrhash);
attrhash = NULL;
}
static void attr_show_all_iterator(struct hash_bucket *bucket, struct vty *vty)
{
struct attr *attr = bucket->data;
vty_out(vty, "attr[%ld] nexthop %s\n", attr->refcnt,
inet_ntoa(attr->nexthop));
vty_out(vty, "\tflags: %" PRIu64 " med: %u local_pref: %u origin: %u weight: %u label: %u\n",
attr->flag, attr->med, attr->local_pref, attr->origin,
attr->weight, attr->label);
}
void attr_show_all(struct vty *vty)
{
hash_iterate(attrhash, (void (*)(struct hash_bucket *,
void *))attr_show_all_iterator,
vty);
}
static void *bgp_attr_hash_alloc(void *p)
{
struct attr *val = (struct attr *)p;
struct attr *attr;
attr = XMALLOC(MTYPE_ATTR, sizeof(struct attr));
*attr = *val;
if (val->encap_subtlvs) {
val->encap_subtlvs = NULL;
}
#if ENABLE_BGP_VNC
if (val->vnc_subtlvs) {
val->vnc_subtlvs = NULL;
}
#endif
attr->refcnt = 0;
return attr;
}
/* Internet argument attribute. */
struct attr *bgp_attr_intern(struct attr *attr)
{
struct attr *find;
/* Intern referenced strucutre. */
if (attr->aspath) {
if (!attr->aspath->refcnt)
attr->aspath = aspath_intern(attr->aspath);
else
attr->aspath->refcnt++;
}
if (attr->community) {
if (!attr->community->refcnt)
attr->community = community_intern(attr->community);
else
attr->community->refcnt++;
}
if (attr->ecommunity) {
if (!attr->ecommunity->refcnt)
attr->ecommunity = ecommunity_intern(attr->ecommunity);
else
attr->ecommunity->refcnt++;
}
if (attr->lcommunity) {
if (!attr->lcommunity->refcnt)
attr->lcommunity = lcommunity_intern(attr->lcommunity);
else
attr->lcommunity->refcnt++;
}
if (attr->cluster) {
if (!attr->cluster->refcnt)
attr->cluster = cluster_intern(attr->cluster);
else
attr->cluster->refcnt++;
}
if (attr->transit) {
if (!attr->transit->refcnt)
attr->transit = transit_intern(attr->transit);
else
attr->transit->refcnt++;
}
if (attr->encap_subtlvs) {
if (!attr->encap_subtlvs->refcnt)
attr->encap_subtlvs = encap_intern(attr->encap_subtlvs,
ENCAP_SUBTLV_TYPE);
else
attr->encap_subtlvs->refcnt++;
}
#if ENABLE_BGP_VNC
if (attr->vnc_subtlvs) {
if (!attr->vnc_subtlvs->refcnt)
attr->vnc_subtlvs = encap_intern(attr->vnc_subtlvs,
VNC_SUBTLV_TYPE);
else
attr->vnc_subtlvs->refcnt++;
}
#endif
/* At this point, attr only contains intern'd pointers. that means
* if we find it in attrhash, it has all the same pointers and we
* correctly updated the refcounts on these.
* If we don't find it, we need to allocate a one because in all
* cases this returns a new reference to a hashed attr, but the input
* wasn't on hash. */
find = (struct attr *)hash_get(attrhash, attr, bgp_attr_hash_alloc);
find->refcnt++;
return find;
}
/* Make network statement's attribute. */
struct attr *bgp_attr_default_set(struct attr *attr, uint8_t origin)
{
memset(attr, 0, sizeof(struct attr));
attr->origin = origin;
attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_ORIGIN);
attr->aspath = aspath_empty();
attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_AS_PATH);
attr->weight = BGP_ATTR_DEFAULT_WEIGHT;
attr->tag = 0;
attr->label_index = BGP_INVALID_LABEL_INDEX;
attr->label = MPLS_INVALID_LABEL;
attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_NEXT_HOP);
attr->mp_nexthop_len = IPV6_MAX_BYTELEN;
return attr;
}
/* Create the attributes for an aggregate */
struct attr *bgp_attr_aggregate_intern(struct bgp *bgp, uint8_t origin,
struct aspath *aspath,
struct community *community,
struct ecommunity *ecommunity,
struct lcommunity *lcommunity,
int as_set, uint8_t atomic_aggregate)
{
struct attr attr;
struct attr *new;
memset(&attr, 0, sizeof(struct attr));
/* Origin attribute. */
attr.origin = origin;
attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_ORIGIN);
/* AS path attribute. */
if (aspath)
attr.aspath = aspath_intern(aspath);
else
attr.aspath = aspath_empty();
attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_AS_PATH);
/* Next hop attribute. */
attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_NEXT_HOP);
if (community) {
uint32_t gshut = COMMUNITY_GSHUT;
/* If we are not shutting down ourselves and we are
* aggregating a route that contains the GSHUT community we
* need to remove that community when creating the aggregate */
if (!bgp_flag_check(bgp, BGP_FLAG_GRACEFUL_SHUTDOWN)
&& community_include(community, gshut)) {
community_del_val(community, &gshut);
}
attr.community = community;
attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_COMMUNITIES);
}
if (ecommunity) {
attr.ecommunity = ecommunity;
attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_EXT_COMMUNITIES);
}
if (lcommunity) {
attr.lcommunity = lcommunity;
attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_LARGE_COMMUNITIES);
}
if (bgp_flag_check(bgp, BGP_FLAG_GRACEFUL_SHUTDOWN)) {
bgp_attr_add_gshut_community(&attr);
}
attr.label_index = BGP_INVALID_LABEL_INDEX;
attr.label = MPLS_INVALID_LABEL;
attr.weight = BGP_ATTR_DEFAULT_WEIGHT;
attr.mp_nexthop_len = IPV6_MAX_BYTELEN;
if (!as_set || atomic_aggregate)
attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_ATOMIC_AGGREGATE);
attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_AGGREGATOR);
if (CHECK_FLAG(bgp->config, BGP_CONFIG_CONFEDERATION))
attr.aggregator_as = bgp->confed_id;
else
attr.aggregator_as = bgp->as;
attr.aggregator_addr = bgp->router_id;
attr.label_index = BGP_INVALID_LABEL_INDEX;
attr.label = MPLS_INVALID_LABEL;
new = bgp_attr_intern(&attr);
aspath_unintern(&new->aspath);
return new;
}
/* Unintern just the sub-components of the attr, but not the attr */
void bgp_attr_unintern_sub(struct attr *attr)
{
/* aspath refcount shoud be decrement. */
if (attr->aspath)
aspath_unintern(&attr->aspath);
UNSET_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_AS_PATH));
if (attr->community)
community_unintern(&attr->community);
UNSET_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_COMMUNITIES));
if (attr->ecommunity)
ecommunity_unintern(&attr->ecommunity);
UNSET_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_EXT_COMMUNITIES));
if (attr->lcommunity)
lcommunity_unintern(&attr->lcommunity);
UNSET_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_LARGE_COMMUNITIES));
if (attr->cluster)
cluster_unintern(attr->cluster);
UNSET_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_CLUSTER_LIST));
if (attr->transit)
transit_unintern(attr->transit);
if (attr->encap_subtlvs)
encap_unintern(&attr->encap_subtlvs, ENCAP_SUBTLV_TYPE);
#if ENABLE_BGP_VNC
if (attr->vnc_subtlvs)
encap_unintern(&attr->vnc_subtlvs, VNC_SUBTLV_TYPE);
#endif
}
/*
* We have some show commands that let you experimentally
* apply a route-map. When we apply the route-map
* we are reseting values but not saving them for
* posterity via intern'ing( because route-maps don't
* do that) but at this point in time we need
* to compare the new attr to the old and if the
* routemap has changed it we need to, as Snoop Dog says,
* Drop it like it's hot
*/
void bgp_attr_undup(struct attr *new, struct attr *old)
{
if (new->aspath != old->aspath)
aspath_free(new->aspath);
if (new->community != old->community)
community_free(&new->community);
if (new->ecommunity != old->ecommunity)
ecommunity_free(&new->ecommunity);
if (new->lcommunity != old->lcommunity)
lcommunity_free(&new->lcommunity);
}
/* Free bgp attribute and aspath. */
void bgp_attr_unintern(struct attr **pattr)
{
struct attr *attr = *pattr;
struct attr *ret;
struct attr tmp;
/* Decrement attribute reference. */
attr->refcnt--;
tmp = *attr;
/* If reference becomes zero then free attribute object. */
if (attr->refcnt == 0) {
ret = hash_release(attrhash, attr);
assert(ret != NULL);
XFREE(MTYPE_ATTR, attr);
*pattr = NULL;
}
bgp_attr_unintern_sub(&tmp);
}
void bgp_attr_flush(struct attr *attr)
{
if (attr->aspath && !attr->aspath->refcnt) {
aspath_free(attr->aspath);
attr->aspath = NULL;
}
if (attr->community && !attr->community->refcnt)
community_free(&attr->community);
if (attr->ecommunity && !attr->ecommunity->refcnt)
ecommunity_free(&attr->ecommunity);
if (attr->lcommunity && !attr->lcommunity->refcnt)
lcommunity_free(&attr->lcommunity);
if (attr->cluster && !attr->cluster->refcnt) {
cluster_free(attr->cluster);
attr->cluster = NULL;
}
if (attr->transit && !attr->transit->refcnt) {
transit_free(attr->transit);
attr->transit = NULL;
}
if (attr->encap_subtlvs && !attr->encap_subtlvs->refcnt) {
encap_free(attr->encap_subtlvs);
attr->encap_subtlvs = NULL;
}
#if ENABLE_BGP_VNC
if (attr->vnc_subtlvs && !attr->vnc_subtlvs->refcnt) {
encap_free(attr->vnc_subtlvs);
attr->vnc_subtlvs = NULL;
}
#endif
}
/* Implement draft-scudder-idr-optional-transitive behaviour and
* avoid resetting sessions for malformed attributes which are
* are partial/optional and hence where the error likely was not
* introduced by the sending neighbour.
*/
static bgp_attr_parse_ret_t
bgp_attr_malformed(struct bgp_attr_parser_args *args, uint8_t subcode,
bgp_size_t length)
{
struct peer *const peer = args->peer;
const uint8_t flags = args->flags;
/* startp and length must be special-cased, as whether or not to
* send the attribute data with the NOTIFY depends on the error,
* the caller therefore signals this with the seperate length argument
*/
uint8_t *notify_datap = (length > 0 ? args->startp : NULL);
/* Only relax error handling for eBGP peers */
if (peer->sort != BGP_PEER_EBGP) {
bgp_notify_send_with_data(peer, BGP_NOTIFY_UPDATE_ERR, subcode,
notify_datap, length);
return BGP_ATTR_PARSE_ERROR;
}
/* Adjust the stream getp to the end of the attribute, in case we can
* still proceed but the caller hasn't read all the attribute.
*/
stream_set_getp(BGP_INPUT(peer),
(args->startp - STREAM_DATA(BGP_INPUT(peer)))
+ args->total);
switch (args->type) {
/* where an attribute is relatively inconsequential, e.g. it does not
* affect route selection, and can be safely ignored, then any such
* attributes which are malformed should just be ignored and the route
* processed as normal.
*/
case BGP_ATTR_AS4_AGGREGATOR:
case BGP_ATTR_AGGREGATOR:
case BGP_ATTR_ATOMIC_AGGREGATE:
return BGP_ATTR_PARSE_PROCEED;
/* Core attributes, particularly ones which may influence route
* selection, should always cause session resets
*/
case BGP_ATTR_ORIGIN:
case BGP_ATTR_AS_PATH:
case BGP_ATTR_NEXT_HOP:
case BGP_ATTR_MULTI_EXIT_DISC:
case BGP_ATTR_LOCAL_PREF:
case BGP_ATTR_COMMUNITIES:
case BGP_ATTR_ORIGINATOR_ID:
case BGP_ATTR_CLUSTER_LIST:
case BGP_ATTR_MP_REACH_NLRI:
case BGP_ATTR_MP_UNREACH_NLRI:
case BGP_ATTR_EXT_COMMUNITIES:
bgp_notify_send_with_data(peer, BGP_NOTIFY_UPDATE_ERR, subcode,
notify_datap, length);
return BGP_ATTR_PARSE_ERROR;
}
/* Partial optional attributes that are malformed should not cause
* the whole session to be reset. Instead treat it as a withdrawal
* of the routes, if possible.
*/
if (CHECK_FLAG(flags, BGP_ATTR_FLAG_TRANS)
&& CHECK_FLAG(flags, BGP_ATTR_FLAG_OPTIONAL)
&& CHECK_FLAG(flags, BGP_ATTR_FLAG_PARTIAL))
return BGP_ATTR_PARSE_WITHDRAW;
/* default to reset */
return BGP_ATTR_PARSE_ERROR_NOTIFYPLS;
}
/* Find out what is wrong with the path attribute flag bits and log the error.
"Flag bits" here stand for Optional, Transitive and Partial, but not for
Extended Length. Checking O/T/P bits at once implies, that the attribute
being diagnosed is defined by RFC as either a "well-known" or an "optional,
non-transitive" attribute. */
static void
bgp_attr_flags_diagnose(struct bgp_attr_parser_args *args,
uint8_t desired_flags /* how RFC says it must be */
)
{
uint8_t seen = 0, i;