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mirror_frr/bgpd/bgp_updgrp_packet.c
vivek 6407da5a24 bgpd: Fixes and updates for VPNv6 
VPNv6 changes picked from upstream needed fixes and updates due to some
fundamental changes implemented by Cumulus (BGP update-groups, RFC 5549
and nexthop setting etc.) which aren't present upstream.

Signed-off-by: Vivek Venkatraman <vivek@cumulusnetworks.com>
Updates: 945c8fe, 8ecd326, bb86c60, 93b73df, f4c8985
2016-06-11 11:36:42 -07:00

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32 KiB
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/**
* bgp_updgrp_packet.c: BGP update group packet handling routines
*
* @copyright Copyright (C) 2014 Cumulus Networks, Inc.
*
* @author Avneesh Sachdev <avneesh@sproute.net>
* @author Rajesh Varadarajan <rajesh@sproute.net>
* @author Pradosh Mohapatra <pradosh@sproute.net>
*
* 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 GNU Zebra; see the file COPYING. If not, write to the Free
* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
* 02111-1307, USA.
*/
#include <zebra.h>
#include "prefix.h"
#include "thread.h"
#include "buffer.h"
#include "stream.h"
#include "command.h"
#include "sockunion.h"
#include "network.h"
#include "memory.h"
#include "filter.h"
#include "routemap.h"
#include "str.h"
#include "log.h"
#include "plist.h"
#include "linklist.h"
#include "workqueue.h"
#include "hash.h"
#include "queue.h"
#include "bgpd/bgpd.h"
#include "bgpd/bgp_debug.h"
#include "bgpd/bgp_fsm.h"
#include "bgpd/bgp_route.h"
#include "bgpd/bgp_packet.h"
#include "bgpd/bgp_advertise.h"
#include "bgpd/bgp_updgrp.h"
#include "bgpd/bgp_nexthop.h"
#include "bgpd/bgp_nht.h"
/********************
* PRIVATE FUNCTIONS
********************/
/********************
* PUBLIC FUNCTIONS
********************/
struct bpacket *
bpacket_alloc ()
{
struct bpacket *pkt;
pkt =
(struct bpacket *) XCALLOC (MTYPE_BGP_PACKET, sizeof (struct bpacket));
return pkt;
}
void
bpacket_free (struct bpacket *pkt)
{
if (pkt->buffer)
stream_free (pkt->buffer);
pkt->buffer = NULL;
XFREE (MTYPE_BGP_PACKET, pkt);
}
void
bpacket_queue_init (struct bpacket_queue *q)
{
TAILQ_INIT (&(q->pkts));
}
/*
* bpacket_queue_sanity_check
*/
void
bpacket_queue_sanity_check (struct bpacket_queue __attribute__ ((__unused__)) *q)
{
#if 0
struct bpacket *pkt;
pkt = bpacket_queue_last (q);
assert (pkt);
assert (!pkt->buffer);
/*
* Make sure the count of packets is correct.
*/
int num_pkts = 0;
pkt = bpacket_queue_first (q);
while (pkt)
{
num_pkts++;
if (num_pkts > q->curr_count)
assert (0);
pkt = TAILQ_NEXT (pkt, pkt_train);
}
assert (num_pkts == q->curr_count);
#endif
}
/*
* bpacket_queue_add_packet
*
* Internal function of bpacket_queue - and adds a
* packet entry to the end of the list.
*
* Users of bpacket_queue should use bpacket_queue_add instead.
*/
static void
bpacket_queue_add_packet (struct bpacket_queue *q, struct bpacket *pkt)
{
struct bpacket *last_pkt;
if (TAILQ_EMPTY (&(q->pkts)))
TAILQ_INSERT_TAIL (&(q->pkts), pkt, pkt_train);
else
{
last_pkt = bpacket_queue_last (q);
TAILQ_INSERT_AFTER (&(q->pkts), last_pkt, pkt, pkt_train);
}
q->curr_count++;
if (q->hwm_count < q->curr_count)
q->hwm_count = q->curr_count;
}
/*
* Adds a packet to the bpacket_queue.
*
* The stream passed is consumed by this function. So, the caller should
* not free or use the stream after
* invoking this function.
*/
struct bpacket *
bpacket_queue_add (struct bpacket_queue *q, struct stream *s,
struct bpacket_attr_vec_arr *vecarrp)
{
struct bpacket *pkt;
struct bpacket *last_pkt;
pkt = bpacket_alloc ();
if (TAILQ_EMPTY (&(q->pkts)))
{
pkt->ver = 1;
pkt->buffer = s;
if (vecarrp)
memcpy (&pkt->arr, vecarrp, sizeof (struct bpacket_attr_vec_arr));
else
bpacket_attr_vec_arr_reset (&pkt->arr);
bpacket_queue_add_packet (q, pkt);
bpacket_queue_sanity_check (q);
return pkt;
}
/*
* Fill in the new information into the current sentinel and create a
* new sentinel.
*/
bpacket_queue_sanity_check (q);
last_pkt = bpacket_queue_last (q);
assert (last_pkt->buffer == NULL);
last_pkt->buffer = s;
if (vecarrp)
memcpy (&last_pkt->arr, vecarrp, sizeof (struct bpacket_attr_vec_arr));
else
bpacket_attr_vec_arr_reset (&last_pkt->arr);
pkt->ver = last_pkt->ver;
pkt->ver++;
bpacket_queue_add_packet (q, pkt);
bpacket_queue_sanity_check (q);
return last_pkt;
}
struct bpacket *
bpacket_queue_first (struct bpacket_queue *q)
{
return (TAILQ_FIRST (&(q->pkts)));
}
struct bpacket *
bpacket_queue_last (struct bpacket_queue *q)
{
return TAILQ_LAST (&(q->pkts), pkt_queue);
}
struct bpacket *
bpacket_queue_remove (struct bpacket_queue *q)
{
struct bpacket *first;
first = bpacket_queue_first (q);
if (first)
{
TAILQ_REMOVE (&(q->pkts), first, pkt_train);
q->curr_count--;
}
return first;
}
unsigned int
bpacket_queue_length (struct bpacket_queue *q)
{
return q->curr_count - 1;
}
unsigned int
bpacket_queue_hwm_length (struct bpacket_queue *q)
{
return q->hwm_count - 1;
}
int
bpacket_queue_is_full (struct bgp *bgp, struct bpacket_queue *q)
{
if (q->curr_count >= bgp->default_subgroup_pkt_queue_max)
return 1;
return 0;
}
void
bpacket_add_peer (struct bpacket *pkt, struct peer_af *paf)
{
if (!pkt || !paf)
return;
LIST_INSERT_HEAD (&(pkt->peers), paf, pkt_train);
paf->next_pkt_to_send = pkt;
}
/*
* bpacket_queue_cleanup
*/
void
bpacket_queue_cleanup (struct bpacket_queue *q)
{
struct bpacket *pkt;
while ((pkt = bpacket_queue_remove (q)))
{
bpacket_free (pkt);
}
}
/*
* bpacket_queue_compact
*
* Delete packets that do not need to be transmitted to any peer from
* the queue.
*
* @return the number of packets deleted.
*/
static int
bpacket_queue_compact (struct bpacket_queue *q)
{
int num_deleted;
struct bpacket *pkt, *removed_pkt;
num_deleted = 0;
while (1)
{
pkt = bpacket_queue_first (q);
if (!pkt)
break;
/*
* Don't delete the sentinel.
*/
if (!pkt->buffer)
break;
if (!LIST_EMPTY (&(pkt->peers)))
break;
removed_pkt = bpacket_queue_remove (q);
assert (pkt == removed_pkt);
bpacket_free (removed_pkt);
num_deleted++;
}
bpacket_queue_sanity_check (q);
return num_deleted;
}
void
bpacket_queue_advance_peer (struct peer_af *paf)
{
struct bpacket *pkt;
struct bpacket *old_pkt;
old_pkt = paf->next_pkt_to_send;
if (old_pkt->buffer == NULL)
/* Already at end of list */
return;
LIST_REMOVE (paf, pkt_train);
pkt = TAILQ_NEXT (old_pkt, pkt_train);
bpacket_add_peer (pkt, paf);
if (!bpacket_queue_compact (PAF_PKTQ (paf)))
return;
/*
* Deleted one or more packets. Check if we can now merge this
* peer's subgroup into another subgroup.
*/
update_subgroup_check_merge (paf->subgroup, "advanced peer in queue");
}
/*
* bpacket_queue_remove_peer
*
* Remove the peer from the packet queue of the subgroup it belongs
* to.
*/
void
bpacket_queue_remove_peer (struct peer_af *paf)
{
struct bpacket_queue *q;
q = PAF_PKTQ (paf);
assert (q);
if (!q)
return;
LIST_REMOVE (paf, pkt_train);
paf->next_pkt_to_send = NULL;
bpacket_queue_compact (q);
}
unsigned int
bpacket_queue_virtual_length (struct peer_af *paf)
{
struct bpacket *pkt;
struct bpacket *last;
struct bpacket_queue *q;
pkt = paf->next_pkt_to_send;
if (!pkt || (pkt->buffer == NULL))
/* Already at end of list */
return 0;
q = PAF_PKTQ (paf);
if (TAILQ_EMPTY (&(q->pkts)))
return 0;
last = TAILQ_LAST (&(q->pkts), pkt_queue);
if (last->ver >= pkt->ver)
return last->ver - pkt->ver;
/* sequence # rolled over */
return (UINT_MAX - pkt->ver + 1) + last->ver;
}
/*
* Dump the bpacket queue
*/
void
bpacket_queue_show_vty (struct bpacket_queue *q, struct vty *vty)
{
struct bpacket *pkt;
struct peer_af *paf;
pkt = bpacket_queue_first (q);
while (pkt)
{
vty_out (vty, " Packet %p ver %u buffer %p%s", pkt, pkt->ver,
pkt->buffer, VTY_NEWLINE);
LIST_FOREACH (paf, &(pkt->peers), pkt_train)
{
vty_out (vty, " - %s%s", paf->peer->host, VTY_NEWLINE);
}
pkt = bpacket_next (pkt);
}
return;
}
struct stream *
bpacket_reformat_for_peer (struct bpacket *pkt, struct peer_af *paf)
{
struct stream *s = NULL;
bpacket_attr_vec *vec;
struct peer *peer;
char buf[BUFSIZ];
char buf2[BUFSIZ];
s = stream_dup (pkt->buffer);
peer = PAF_PEER(paf);
vec = &pkt->arr.entries[BGP_ATTR_VEC_NH];
if (CHECK_FLAG (vec->flags, BPKT_ATTRVEC_FLAGS_UPDATED))
{
u_int8_t nhlen;
int route_map_sets_nh;
nhlen = stream_getc_from (s, vec->offset);
if (paf->afi == AFI_IP && !peer_cap_enhe(peer))
{
struct in_addr v4nh, *mod_v4nh;
int nh_modified = 0;
route_map_sets_nh =
(CHECK_FLAG (vec->flags, BPKT_ATTRVEC_FLAGS_RMAP_IPV4_NH_CHANGED) ||
CHECK_FLAG (vec->flags, BPKT_ATTRVEC_FLAGS_RMAP_NH_PEER_ADDRESS));
stream_get_from (&v4nh, s, vec->offset + 1, 4);
mod_v4nh = &v4nh;
/*
* If route-map has set the nexthop, that is always used; if it is
* specified as peer-address, the peering address is picked up.
* Otherwise, if NH is unavailable from attribute, the peering addr
* is picked up; the "NH unavailable" case also covers next-hop-self
* and some other scenarios -- see subgroup_announce_check(). In
* all other cases, use the nexthop carried in the attribute unless
* it is EBGP non-multiaccess and there is no next-hop-unchanged setting.
* Note: It is assumed route-map cannot set the nexthop to an
* invalid value.
*/
if (route_map_sets_nh)
{
if (CHECK_FLAG(vec->flags,
BPKT_ATTRVEC_FLAGS_RMAP_NH_PEER_ADDRESS))
{
mod_v4nh = &peer->nexthop.v4;
nh_modified = 1;
}
}
else if (!v4nh.s_addr)
{
mod_v4nh = &peer->nexthop.v4;
nh_modified = 1;
}
else if (peer->sort == BGP_PEER_EBGP &&
(bgp_multiaccess_check_v4 (v4nh, peer) == 0) &&
!CHECK_FLAG(vec->flags,
BPKT_ATTRVEC_FLAGS_RMAP_NH_UNCHANGED) &&
!peer_af_flag_check (peer, paf->afi, paf->safi,
PEER_FLAG_NEXTHOP_UNCHANGED))
{
mod_v4nh = &peer->nexthop.v4;
nh_modified = 1;
}
if (nh_modified)
stream_put_in_addr_at (s, vec->offset + 1, mod_v4nh);
if (bgp_debug_update(peer, NULL, NULL, 0))
zlog_debug ("u%" PRIu64 ":s%" PRIu64 " %s send UPDATE w/ nexthop %s",
PAF_SUBGRP(paf)->update_group->id, PAF_SUBGRP(paf)->id,
peer->host, inet_ntoa (*mod_v4nh));
}
else if (paf->afi == AFI_IP6 || peer_cap_enhe(peer))
{
struct in6_addr v6nhglobal, *mod_v6nhg;
struct in6_addr v6nhlocal, *mod_v6nhl;
int gnh_modified, lnh_modified;
gnh_modified = lnh_modified = 0;
mod_v6nhg = &v6nhglobal;
mod_v6nhl = &v6nhlocal;
route_map_sets_nh =
(CHECK_FLAG (vec->flags, BPKT_ATTRVEC_FLAGS_RMAP_IPV6_GNH_CHANGED) ||
CHECK_FLAG (vec->flags, BPKT_ATTRVEC_FLAGS_RMAP_NH_PEER_ADDRESS));
/*
* The logic here is rather similar to that for IPv4, the
* additional work being to handle 1 or 2 nexthops. Also, 3rd
* party nexthop is not propagated for EBGP right now.
*/
stream_get_from (&v6nhglobal, s, vec->offset + 1, 16);
if (route_map_sets_nh)
{
if (CHECK_FLAG(vec->flags,
BPKT_ATTRVEC_FLAGS_RMAP_NH_PEER_ADDRESS))
{
mod_v6nhg = &peer->nexthop.v6_global;
gnh_modified = 1;
}
}
else if (IN6_IS_ADDR_UNSPECIFIED (&v6nhglobal))
{
mod_v6nhg = &peer->nexthop.v6_global;
gnh_modified = 1;
}
else if (peer->sort == BGP_PEER_EBGP &&
!CHECK_FLAG(vec->flags,
BPKT_ATTRVEC_FLAGS_RMAP_NH_UNCHANGED) &&
!peer_af_flag_check (peer, paf->afi, paf->safi,
PEER_FLAG_NEXTHOP_UNCHANGED))
{
mod_v6nhg = &peer->nexthop.v6_global;
gnh_modified = 1;
}
if (nhlen == 32)
{
stream_get_from (&v6nhlocal, s, vec->offset + 1 + 16, 16);
if (IN6_IS_ADDR_UNSPECIFIED (&v6nhlocal))
{
mod_v6nhl = &peer->nexthop.v6_local;
lnh_modified = 1;
}
}
if (gnh_modified)
stream_put_in6_addr_at (s, vec->offset + 1, mod_v6nhg);
if (lnh_modified)
stream_put_in6_addr_at (s, vec->offset + 1 + 16, mod_v6nhl);
if (bgp_debug_update(peer, NULL, NULL, 0))
{
if (nhlen == 32)
zlog_debug ("u%" PRIu64 ":s%" PRIu64 " %s send UPDATE w/ mp_nexthops %s, %s",
PAF_SUBGRP(paf)->update_group->id,
PAF_SUBGRP(paf)->id,
peer->host,
inet_ntop (AF_INET6, mod_v6nhg, buf, BUFSIZ),
inet_ntop (AF_INET6, mod_v6nhl, buf2, BUFSIZ));
else
zlog_debug ("u%" PRIu64 ":s%" PRIu64 " %s send UPDATE w/ mp_nexthop %s",
PAF_SUBGRP(paf)->update_group->id,
PAF_SUBGRP(paf)->id,
peer->host,
inet_ntop (AF_INET6, mod_v6nhg, buf, BUFSIZ));
}
}
}
bgp_packet_add (peer, s);
return s;
}
/*
* Update the vecarr offsets to go beyond 'pos' bytes, i.e. add 'pos'
* to each offset.
*/
static void
bpacket_attr_vec_arr_update (struct bpacket_attr_vec_arr *vecarr, size_t pos)
{
int i;
if (!vecarr)
return;
for (i = 0; i < BGP_ATTR_VEC_MAX; i++)
vecarr->entries[i].offset += pos;
}
/*
* Return if there are packets to build for this subgroup.
*/
int
subgroup_packets_to_build (struct update_subgroup *subgrp)
{
struct bgp_advertise *adv;
if (!subgrp)
return 0;
adv = BGP_ADV_FIFO_HEAD (&subgrp->sync->withdraw);
if (adv)
return 1;
adv = BGP_ADV_FIFO_HEAD (&subgrp->sync->update);
if (adv)
return 1;
return 0;
}
static void
bgp_info_addpath_tx_str (int addpath_encode, u_int32_t addpath_tx_id,
char *buf)
{
if (addpath_encode)
sprintf(buf, " with addpath ID %d", addpath_tx_id);
}
/* Make BGP update packet. */
struct bpacket *
subgroup_update_packet (struct update_subgroup *subgrp)
{
struct bpacket_attr_vec_arr vecarr;
struct bpacket *pkt;
struct peer *peer;
struct stream *s;
struct stream *snlri;
struct stream *packet;
struct bgp_adj_out *adj;
struct bgp_advertise *adv;
struct bgp_node *rn = NULL;
struct bgp_info *binfo = NULL;
bgp_size_t total_attr_len = 0;
unsigned long attrlen_pos = 0;
size_t mpattrlen_pos = 0;
size_t mpattr_pos = 0;
afi_t afi;
safi_t safi;
int space_remaining = 0;
int space_needed = 0;
char send_attr_str[BUFSIZ];
int send_attr_printed = 0;
int num_pfx = 0;
int addpath_encode = 0;
u_int32_t addpath_tx_id = 0;
if (!subgrp)
return NULL;
if (bpacket_queue_is_full (SUBGRP_INST (subgrp), SUBGRP_PKTQ (subgrp)))
return NULL;
peer = SUBGRP_PEER (subgrp);
afi = SUBGRP_AFI (subgrp);
safi = SUBGRP_SAFI (subgrp);
s = subgrp->work;
stream_reset (s);
snlri = subgrp->scratch;
stream_reset (snlri);
bpacket_attr_vec_arr_reset (&vecarr);
addpath_encode = bgp_addpath_encode_tx (peer, afi, safi);
adv = BGP_ADV_FIFO_HEAD (&subgrp->sync->update);
while (adv)
{
assert (adv->rn);
rn = adv->rn;
adj = adv->adj;
addpath_tx_id = adj->addpath_tx_id;
binfo = adv->binfo;
space_remaining = STREAM_CONCAT_REMAIN (s, snlri, STREAM_SIZE(s)) -
BGP_MAX_PACKET_SIZE_OVERFLOW;
space_needed = BGP_NLRI_LENGTH +
bgp_packet_mpattr_prefix_size (afi, safi, &rn->p);
/* When remaining space can't include NLRI and it's length. */
if (space_remaining < space_needed)
break;
/* If packet is empty, set attribute. */
if (stream_empty (s))
{
struct peer *from = NULL;
if (binfo)
from = binfo->peer;
/* 1: Write the BGP message header - 16 bytes marker, 2 bytes length,
* one byte message type.
*/
bgp_packet_set_marker (s, BGP_MSG_UPDATE);
/* 2: withdrawn routes length */
stream_putw (s, 0);
/* 3: total attributes length - attrlen_pos stores the position */
attrlen_pos = stream_get_endp (s);
stream_putw (s, 0);
/* 4: if there is MP_REACH_NLRI attribute, that should be the first
* attribute, according to draft-ietf-idr-error-handling. Save the
* position.
*/
mpattr_pos = stream_get_endp (s);
/* 5: Encode all the attributes, except MP_REACH_NLRI attr. */
total_attr_len = bgp_packet_attribute (NULL, peer, s,
adv->baa->attr, &vecarr,
NULL, afi, safi,
from, NULL, NULL, 0, 0);
space_remaining = STREAM_CONCAT_REMAIN (s, snlri, STREAM_SIZE(s)) -
BGP_MAX_PACKET_SIZE_OVERFLOW;
space_needed = BGP_NLRI_LENGTH +
bgp_packet_mpattr_prefix_size (afi, safi, &rn->p);
/* If the attributes alone do not leave any room for NLRI then
* return */
if (space_remaining < space_needed)
{
zlog_err ("u%" PRIu64 ":s%" PRIu64 " attributes too long, cannot send UPDATE",
subgrp->update_group->id, subgrp->id);
/* Flush the FIFO update queue */
while (adv)
adv = bgp_advertise_clean_subgroup (subgrp, adj);
return NULL;
}
if (BGP_DEBUG (update, UPDATE_OUT) ||
BGP_DEBUG (update, UPDATE_PREFIX))
{
memset (send_attr_str, 0, BUFSIZ);
send_attr_printed = 0;
bgp_dump_attr (peer, adv->baa->attr, send_attr_str, BUFSIZ);
}
}
if ((afi == AFI_IP && safi == SAFI_UNICAST) &&
!peer_cap_enhe(peer))
stream_put_prefix_addpath (s, &rn->p, addpath_encode, addpath_tx_id);
else
{
/* Encode the prefix in MP_REACH_NLRI attribute */
struct prefix_rd *prd = NULL;
u_char *tag = NULL;
if (rn->prn)
prd = (struct prefix_rd *) &rn->prn->p;
if (binfo && binfo->extra)
tag = binfo->extra->tag;
if (stream_empty (snlri))
mpattrlen_pos = bgp_packet_mpattr_start (snlri, afi, safi,
(peer_cap_enhe(peer) ? AFI_IP6 : afi),
&vecarr, adv->baa->attr);
bgp_packet_mpattr_prefix (snlri, afi, safi, &rn->p, prd, tag,
addpath_encode, addpath_tx_id);
}
num_pfx++;
if (bgp_debug_update(NULL, &rn->p, subgrp->update_group, 0))
{
char buf[INET6_BUFSIZ];
char tx_id_buf[30];
if (!send_attr_printed)
{
zlog_debug ("u%" PRIu64 ":s%" PRIu64 " send UPDATE w/ attr: %s",
subgrp->update_group->id, subgrp->id, send_attr_str);
send_attr_printed = 1;
}
bgp_info_addpath_tx_str (addpath_encode, addpath_tx_id, tx_id_buf);
zlog_debug ("u%" PRIu64 ":s%" PRIu64 " send UPDATE %s/%d%s",
subgrp->update_group->id, subgrp->id,
inet_ntop (rn->p.family, &(rn->p.u.prefix), buf, INET6_BUFSIZ),
rn->p.prefixlen, tx_id_buf);
}
/* Synchnorize attribute. */
if (adj->attr)
bgp_attr_unintern (&adj->attr);
else
subgrp->scount++;
adj->attr = bgp_attr_intern (adv->baa->attr);
adv = bgp_advertise_clean_subgroup (subgrp, adj);
}
if (!stream_empty (s))
{
if (!stream_empty (snlri))
{
bgp_packet_mpattr_end (snlri, mpattrlen_pos);
total_attr_len += stream_get_endp (snlri);
}
/* set the total attribute length correctly */
stream_putw_at (s, attrlen_pos, total_attr_len);
if (!stream_empty (snlri))
{
packet = stream_dupcat (s, snlri, mpattr_pos);
bpacket_attr_vec_arr_update (&vecarr, mpattr_pos);
}
else
packet = stream_dup (s);
bgp_packet_set_size (packet);
if (bgp_debug_update(NULL, NULL, subgrp->update_group, 0))
zlog_debug ("u%" PRIu64 ":s%" PRIu64 " UPDATE len %zd numpfx %d",
subgrp->update_group->id, subgrp->id,
(stream_get_endp(packet) - stream_get_getp(packet)), num_pfx);
pkt = bpacket_queue_add (SUBGRP_PKTQ (subgrp), packet, &vecarr);
stream_reset (s);
stream_reset (snlri);
return pkt;
}
return NULL;
}
/* Make BGP withdraw packet. */
/* For ipv4 unicast:
16-octet marker | 2-octet length | 1-octet type |
2-octet withdrawn route length | withdrawn prefixes | 2-octet attrlen (=0)
*/
/* For other afi/safis:
16-octet marker | 2-octet length | 1-octet type |
2-octet withdrawn route length (=0) | 2-octet attrlen |
mp_unreach attr type | attr len | afi | safi | withdrawn prefixes
*/
struct bpacket *
subgroup_withdraw_packet (struct update_subgroup *subgrp)
{
struct bpacket *pkt;
struct stream *s;
struct bgp_adj_out *adj;
struct bgp_advertise *adv;
struct peer *peer;
struct bgp_node *rn;
bgp_size_t unfeasible_len;
bgp_size_t total_attr_len;
size_t mp_start = 0;
size_t attrlen_pos = 0;
size_t mplen_pos = 0;
u_char first_time = 1;
afi_t afi;
safi_t safi;
int space_remaining = 0;
int space_needed = 0;
int num_pfx = 0;
int addpath_encode = 0;
u_int32_t addpath_tx_id = 0;
if (!subgrp)
return NULL;
if (bpacket_queue_is_full (SUBGRP_INST (subgrp), SUBGRP_PKTQ (subgrp)))
return NULL;
peer = SUBGRP_PEER (subgrp);
afi = SUBGRP_AFI (subgrp);
safi = SUBGRP_SAFI (subgrp);
s = subgrp->work;
stream_reset (s);
addpath_encode = bgp_addpath_encode_tx (peer, afi, safi);
while ((adv = BGP_ADV_FIFO_HEAD (&subgrp->sync->withdraw)) != NULL)
{
assert (adv->rn);
adj = adv->adj;
rn = adv->rn;
addpath_tx_id = adj->addpath_tx_id;
space_remaining = STREAM_REMAIN (s) -
BGP_MAX_PACKET_SIZE_OVERFLOW;
space_needed = BGP_NLRI_LENGTH + BGP_TOTAL_ATTR_LEN +
bgp_packet_mpattr_prefix_size (afi, safi, &rn->p);
if (space_remaining < space_needed)
break;
if (stream_empty (s))
{
bgp_packet_set_marker (s, BGP_MSG_UPDATE);
stream_putw (s, 0); /* unfeasible routes length */
}
else
first_time = 0;
if (afi == AFI_IP && safi == SAFI_UNICAST &&
!peer_cap_enhe(peer))
stream_put_prefix_addpath (s, &rn->p, addpath_encode, addpath_tx_id);
else
{
struct prefix_rd *prd = NULL;
if (rn->prn)
prd = (struct prefix_rd *) &rn->prn->p;
/* If first time, format the MP_UNREACH header */
if (first_time)
{
attrlen_pos = stream_get_endp (s);
/* total attr length = 0 for now. reevaluate later */
stream_putw (s, 0);
mp_start = stream_get_endp (s);
mplen_pos = bgp_packet_mpunreach_start (s, afi, safi);
}
bgp_packet_mpunreach_prefix (s, &rn->p, afi, safi, prd, NULL,
addpath_encode, addpath_tx_id);
}
num_pfx++;
if (bgp_debug_update(NULL, &rn->p, subgrp->update_group, 0))
{
char buf[INET6_BUFSIZ];
char tx_id_buf[30];
bgp_info_addpath_tx_str (addpath_encode, addpath_tx_id, tx_id_buf);
zlog_debug ("u%" PRIu64 ":s%" PRIu64 " send UPDATE %s/%d%s -- unreachable",
subgrp->update_group->id, subgrp->id,
inet_ntop (rn->p.family, &(rn->p.u.prefix), buf, INET6_BUFSIZ),
rn->p.prefixlen, tx_id_buf);
}
subgrp->scount--;
bgp_adj_out_remove_subgroup (rn, adj, subgrp);
bgp_unlock_node (rn);
}
if (!stream_empty (s))
{
if (afi == AFI_IP && safi == SAFI_UNICAST &&
!peer_cap_enhe(peer))
{
unfeasible_len
= stream_get_endp (s) - BGP_HEADER_SIZE - BGP_UNFEASIBLE_LEN;
stream_putw_at (s, BGP_HEADER_SIZE, unfeasible_len);
stream_putw (s, 0);
}
else
{
/* Set the mp_unreach attr's length */
bgp_packet_mpunreach_end (s, mplen_pos);
/* Set total path attribute length. */
total_attr_len = stream_get_endp (s) - mp_start;
stream_putw_at (s, attrlen_pos, total_attr_len);
}
bgp_packet_set_size (s);
if (bgp_debug_update(NULL, NULL, subgrp->update_group, 0))
zlog_debug ("u%" PRIu64 ":s%" PRIu64 " UPDATE (withdraw) len %zd numpfx %d",
subgrp->update_group->id, subgrp->id,
(stream_get_endp(s) - stream_get_getp(s)), num_pfx);
pkt = bpacket_queue_add (SUBGRP_PKTQ (subgrp), stream_dup (s), NULL);
stream_reset (s);
return pkt;
}
return NULL;
}
void
subgroup_default_update_packet (struct update_subgroup *subgrp,
struct attr *attr, struct peer *from)
{
struct stream *s;
struct peer *peer;
struct prefix p;
unsigned long pos;
bgp_size_t total_attr_len;
afi_t afi;
safi_t safi;
struct bpacket_attr_vec_arr vecarr;
int addpath_encode = 0;
if (DISABLE_BGP_ANNOUNCE)
return;
if (!subgrp)
return;
peer = SUBGRP_PEER (subgrp);
afi = SUBGRP_AFI (subgrp);
safi = SUBGRP_SAFI (subgrp);
bpacket_attr_vec_arr_reset (&vecarr);
addpath_encode = bgp_addpath_encode_tx (peer, afi, safi);
if (afi == AFI_IP)
str2prefix ("0.0.0.0/0", &p);
#ifdef HAVE_IPV6
else
str2prefix ("::/0", &p);
#endif /* HAVE_IPV6 */
/* Logging the attribute. */
if (bgp_debug_update(NULL, &p, subgrp->update_group, 0))
{
char attrstr[BUFSIZ];
char buf[INET6_BUFSIZ];
char tx_id_buf[30];
attrstr[0] = '\0';
bgp_dump_attr (peer, attr, attrstr, BUFSIZ);
bgp_info_addpath_tx_str (addpath_encode, BGP_ADDPATH_TX_ID_FOR_DEFAULT_ORIGINATE, tx_id_buf);
zlog_debug ("u%" PRIu64 ":s%" PRIu64 " send UPDATE %s/%d%s %s",
(SUBGRP_UPDGRP (subgrp))->id, subgrp->id,
inet_ntop (p.family, &(p.u.prefix), buf, INET6_BUFSIZ),
p.prefixlen, tx_id_buf, attrstr);
}
s = stream_new (BGP_MAX_PACKET_SIZE);
/* Make BGP update packet. */
bgp_packet_set_marker (s, BGP_MSG_UPDATE);
/* Unfeasible Routes Length. */
stream_putw (s, 0);
/* Make place for total attribute length. */
pos = stream_get_endp (s);
stream_putw (s, 0);
total_attr_len = bgp_packet_attribute (NULL, peer, s, attr, &vecarr, &p,
afi, safi, from, NULL, NULL,
addpath_encode,
BGP_ADDPATH_TX_ID_FOR_DEFAULT_ORIGINATE);
/* Set Total Path Attribute Length. */
stream_putw_at (s, pos, total_attr_len);
/* NLRI set. */
if (p.family == AF_INET && safi == SAFI_UNICAST &&
!peer_cap_enhe(peer))
stream_put_prefix_addpath (s, &p, addpath_encode, BGP_ADDPATH_TX_ID_FOR_DEFAULT_ORIGINATE);
/* Set size. */
bgp_packet_set_size (s);
(void) bpacket_queue_add (SUBGRP_PKTQ (subgrp), s, &vecarr);
subgroup_trigger_write(subgrp);
}
void
subgroup_default_withdraw_packet (struct update_subgroup *subgrp)
{
struct peer *peer;
struct stream *s;
struct prefix p;
unsigned long attrlen_pos = 0;
unsigned long cp;
bgp_size_t unfeasible_len;
bgp_size_t total_attr_len = 0;
size_t mp_start = 0;
size_t mplen_pos = 0;
afi_t afi;
safi_t safi;
int addpath_encode = 0;
if (DISABLE_BGP_ANNOUNCE)
return;
peer = SUBGRP_PEER (subgrp);
afi = SUBGRP_AFI (subgrp);
safi = SUBGRP_SAFI (subgrp);
addpath_encode = bgp_addpath_encode_tx (peer, afi, safi);
if (afi == AFI_IP)
str2prefix ("0.0.0.0/0", &p);
#ifdef HAVE_IPV6
else
str2prefix ("::/0", &p);
#endif /* HAVE_IPV6 */
if (bgp_debug_update(NULL, &p, subgrp->update_group, 0))
{
char buf[INET6_BUFSIZ];
char tx_id_buf[INET6_BUFSIZ];
bgp_info_addpath_tx_str (addpath_encode, BGP_ADDPATH_TX_ID_FOR_DEFAULT_ORIGINATE, tx_id_buf);
zlog_debug ("u%" PRIu64 ":s%" PRIu64 " send UPDATE %s/%d%s -- unreachable",
(SUBGRP_UPDGRP (subgrp))->id, subgrp->id,
inet_ntop (p.family, &(p.u.prefix), buf, INET6_BUFSIZ),
p.prefixlen, tx_id_buf);
}
s = stream_new (BGP_MAX_PACKET_SIZE);
/* Make BGP update packet. */
bgp_packet_set_marker (s, BGP_MSG_UPDATE);
/* Unfeasible Routes Length. */ ;
cp = stream_get_endp (s);
stream_putw (s, 0);
/* Withdrawn Routes. */
if (p.family == AF_INET && safi == SAFI_UNICAST &&
!peer_cap_enhe(peer))
{
stream_put_prefix_addpath (s, &p, addpath_encode,
BGP_ADDPATH_TX_ID_FOR_DEFAULT_ORIGINATE);
unfeasible_len = stream_get_endp (s) - cp - 2;
/* Set unfeasible len. */
stream_putw_at (s, cp, unfeasible_len);
/* Set total path attribute length. */
stream_putw (s, 0);
}
else
{
attrlen_pos = stream_get_endp (s);
stream_putw (s, 0);
mp_start = stream_get_endp (s);
mplen_pos = bgp_packet_mpunreach_start (s, afi, safi);
bgp_packet_mpunreach_prefix (s, &p, afi, safi, NULL, NULL,
addpath_encode,
BGP_ADDPATH_TX_ID_FOR_DEFAULT_ORIGINATE);
/* Set the mp_unreach attr's length */
bgp_packet_mpunreach_end (s, mplen_pos);
/* Set total path attribute length. */
total_attr_len = stream_get_endp (s) - mp_start;
stream_putw_at (s, attrlen_pos, total_attr_len);
}
bgp_packet_set_size (s);
(void) bpacket_queue_add (SUBGRP_PKTQ (subgrp), s, NULL);
subgroup_trigger_write(subgrp);
}
static void
bpacket_vec_arr_inherit_attr_flags (struct bpacket_attr_vec_arr *vecarr,
bpacket_attr_vec_type type,
struct attr *attr)
{
if (CHECK_FLAG (attr->rmap_change_flags,
BATTR_RMAP_NEXTHOP_PEER_ADDRESS))
SET_FLAG (vecarr->entries[BGP_ATTR_VEC_NH].flags,
BPKT_ATTRVEC_FLAGS_RMAP_NH_PEER_ADDRESS);
if (CHECK_FLAG (attr->rmap_change_flags, BATTR_REFLECTED))
SET_FLAG (vecarr->entries[BGP_ATTR_VEC_NH].flags,
BPKT_ATTRVEC_FLAGS_REFLECTED);
if (CHECK_FLAG (attr->rmap_change_flags,
BATTR_RMAP_NEXTHOP_UNCHANGED))
SET_FLAG (vecarr->entries[BGP_ATTR_VEC_NH].flags,
BPKT_ATTRVEC_FLAGS_RMAP_NH_UNCHANGED);
if (CHECK_FLAG (attr->rmap_change_flags,
BATTR_RMAP_IPV4_NHOP_CHANGED))
SET_FLAG (vecarr->entries[BGP_ATTR_VEC_NH].flags,
BPKT_ATTRVEC_FLAGS_RMAP_IPV4_NH_CHANGED);
if (CHECK_FLAG (attr->rmap_change_flags,
BATTR_RMAP_IPV6_GLOBAL_NHOP_CHANGED))
SET_FLAG (vecarr->entries[BGP_ATTR_VEC_NH].flags,
BPKT_ATTRVEC_FLAGS_RMAP_IPV6_GNH_CHANGED);
if (CHECK_FLAG (attr->rmap_change_flags,
BATTR_RMAP_IPV6_LL_NHOP_CHANGED))
SET_FLAG (vecarr->entries[BGP_ATTR_VEC_NH].flags,
BPKT_ATTRVEC_FLAGS_RMAP_IPV6_LNH_CHANGED);
}
/* Reset the Attributes vector array. The vector array is used to override
* certain output parameters in the packet for a particular peer
*/
void
bpacket_attr_vec_arr_reset (struct bpacket_attr_vec_arr *vecarr)
{
int i;
if (!vecarr)
return;
i = 0;
while (i < BGP_ATTR_VEC_MAX)
{
vecarr->entries[i].flags = 0;
vecarr->entries[i].offset = 0;
i++;
}
}
/* Setup a particular node entry in the vecarr */
void
bpacket_attr_vec_arr_set_vec (struct bpacket_attr_vec_arr *vecarr,
bpacket_attr_vec_type type, struct stream *s,
struct attr *attr)
{
if (!vecarr)
return;
assert (type < BGP_ATTR_VEC_MAX);
SET_FLAG (vecarr->entries[type].flags, BPKT_ATTRVEC_FLAGS_UPDATED);
vecarr->entries[type].offset = stream_get_endp (s);
if (attr)
bpacket_vec_arr_inherit_attr_flags(vecarr, type, attr);
}
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