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/* $OpenBSD: lsack.c,v 1.10 2023/03/08 04:43:14 guenther Exp $ */
/*
* Copyright (c) 2004, 2005, 2007 Esben Norby <norby@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/socket.h>
#include <netinet/in.h>
#include <netinet/ip6.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <string.h>
#include "ospf6d.h"
#include "ospf6.h"
#include "log.h"
#include "ospfe.h"
int send_ls_ack(struct iface *, struct in6_addr, struct ibuf *);
struct ibuf *prepare_ls_ack(struct iface *);
void start_ls_ack_tx_timer_now(struct iface *);
/* link state acknowledgement packet handling */
struct ibuf *
prepare_ls_ack(struct iface *iface)
{
struct ibuf *buf;
if ((buf = ibuf_open(iface->mtu - sizeof(struct ip6_hdr))) == NULL) {
log_warn("prepare_ls_ack");
return (NULL);
}
/* OSPF header */
if (gen_ospf_hdr(buf, iface, PACKET_TYPE_LS_ACK)) {
log_warn("prepare_ls_ack");
ibuf_free(buf);
return (NULL);
}
return (buf);
}
int
send_ls_ack(struct iface *iface, struct in6_addr addr, struct ibuf *buf)
{
/* calculate checksum */
if (upd_ospf_hdr(buf, iface)) {
log_warn("send_ls_ack");
return (-1);
}
if (send_packet(iface, buf, &addr) == -1) {
log_warn("send_ls_ack");
return (-1);
}
return (0);
}
int
send_direct_ack(struct iface *iface, struct in6_addr addr, void *d, size_t len)
{
struct ibuf *buf;
int ret;
if ((buf = prepare_ls_ack(iface)) == NULL)
return (-1);
/* LS ack(s) */
if (ibuf_add(buf, d, len)) {
log_warn("send_direct_ack");
ibuf_free(buf);
return (-1);
}
ret = send_ls_ack(iface, addr, buf);
ibuf_free(buf);
return (ret);
}
void
recv_ls_ack(struct nbr *nbr, char *buf, u_int16_t len)
{
struct lsa_hdr lsa_hdr;
switch (nbr->state) {
case NBR_STA_DOWN:
case NBR_STA_ATTEMPT:
case NBR_STA_INIT:
case NBR_STA_2_WAY:
case NBR_STA_XSTRT:
case NBR_STA_SNAP:
log_debug("recv_ls_ack: packet ignored in state %s, "
"neighbor ID %s (%s)", nbr_state_name(nbr->state),
inet_ntoa(nbr->id), nbr->iface->name);
break;
case NBR_STA_XCHNG:
case NBR_STA_LOAD:
case NBR_STA_FULL:
while (len >= sizeof(lsa_hdr)) {
memcpy(&lsa_hdr, buf, sizeof(lsa_hdr));
if (lsa_hdr_check(nbr, &lsa_hdr)) {
/* try both list in case of DROTHER */
if (nbr->iface->state & IF_STA_DROTHER)
(void)ls_retrans_list_del(
nbr->iface->self, &lsa_hdr);
(void)ls_retrans_list_del(nbr, &lsa_hdr);
}
buf += sizeof(lsa_hdr);
len -= sizeof(lsa_hdr);
}
if (len > 0) {
log_warnx("recv_ls_ack: bad packet size, "
"neighbor ID %s (%s)", inet_ntoa(nbr->id),
nbr->iface->name);
return;
}
break;
default:
fatalx("recv_ls_ack: unknown neighbor state");
}
}
int
lsa_hdr_check(struct nbr *nbr, struct lsa_hdr *lsa_hdr)
{
/* invalid age */
if ((ntohs(lsa_hdr->age) < 1) || (ntohs(lsa_hdr->age) > MAX_AGE)) {
log_debug("lsa_hdr_check: invalid age, neighbor ID %s (%s)",
inet_ntoa(nbr->id), nbr->iface->name);
return (0);
}
/* invalid type */
switch (ntohs(lsa_hdr->type)) {
case LSA_TYPE_LINK:
case LSA_TYPE_ROUTER:
case LSA_TYPE_NETWORK:
case LSA_TYPE_INTER_A_PREFIX:
case LSA_TYPE_INTER_A_ROUTER:
case LSA_TYPE_INTRA_A_PREFIX:
case LSA_TYPE_EXTERNAL:
break;
default:
log_debug("lsa_hdr_check: invalid LSA type %d, "
"neighbor ID %s (%s)",
lsa_hdr->type, inet_ntoa(nbr->id), nbr->iface->name);
return (0);
}
/* invalid sequence number */
if (ntohl(lsa_hdr->seq_num) == RESV_SEQ_NUM) {
log_debug("ls_hdr_check: invalid seq num, "
"neighbor ID %s (%s)", inet_ntoa(nbr->id),
nbr->iface->name);
return (0);
}
return (1);
}
/* link state ack list */
void
ls_ack_list_add(struct iface *iface, struct lsa_hdr *lsa)
{
struct lsa_entry *le;
if (lsa == NULL)
fatalx("ls_ack_list_add: no LSA header");
if ((le = calloc(1, sizeof(*le))) == NULL)
fatal("ls_ack_list_add");
if (ls_ack_list_empty(iface))
start_ls_ack_tx_timer(iface);
TAILQ_INSERT_TAIL(&iface->ls_ack_list, le, entry);
le->le_lsa = lsa;
iface->ls_ack_cnt++;
/* reschedule now if we have enough for a full packet */
if (iface->ls_ack_cnt >
((iface->mtu - PACKET_HDR) / sizeof(struct lsa_hdr))) {
start_ls_ack_tx_timer_now(iface);
}
}
void
ls_ack_list_free(struct iface *iface, struct lsa_entry *le)
{
TAILQ_REMOVE(&iface->ls_ack_list, le, entry);
free(le->le_lsa);
free(le);
iface->ls_ack_cnt--;
}
void
ls_ack_list_clr(struct iface *iface)
{
struct lsa_entry *le;
while ((le = TAILQ_FIRST(&iface->ls_ack_list)) != NULL) {
TAILQ_REMOVE(&iface->ls_ack_list, le, entry);
free(le->le_lsa);
free(le);
}
iface->ls_ack_cnt = 0;
}
int
ls_ack_list_empty(struct iface *iface)
{
return (TAILQ_EMPTY(&iface->ls_ack_list));
}
/* timers */
void
ls_ack_tx_timer(int fd, short event, void *arg)
{
struct in6_addr addr;
struct iface *iface = arg;
struct lsa_entry *le, *nle;
struct nbr *nbr;
struct ibuf *buf;
int cnt;
while (!ls_ack_list_empty(iface)) {
if ((buf = prepare_ls_ack(iface)) == NULL)
fatal("ls_ack_tx_timer");
cnt = 0;
for (le = TAILQ_FIRST(&iface->ls_ack_list); le != NULL;
le = nle) {
nle = TAILQ_NEXT(le, entry);
if (ibuf_left(buf) < sizeof(struct lsa_hdr))
break;
if (ibuf_add(buf, le->le_lsa, sizeof(struct lsa_hdr)))
break;
ls_ack_list_free(iface, le);
cnt++;
}
if (cnt == 0) {
log_warnx("ls_ack_tx_timer: lost in space");
ibuf_free(buf);
return;
}
/* send LS ack(s) but first set correct destination */
switch (iface->type) {
case IF_TYPE_POINTOPOINT:
inet_pton(AF_INET6, AllSPFRouters, &addr);
send_ls_ack(iface, addr, buf);
break;
case IF_TYPE_BROADCAST:
if (iface->state & IF_STA_DRORBDR)
inet_pton(AF_INET6, AllSPFRouters, &addr);
else
inet_pton(AF_INET6, AllDRouters, &addr);
send_ls_ack(iface, addr, buf);
break;
case IF_TYPE_NBMA:
case IF_TYPE_POINTOMULTIPOINT:
case IF_TYPE_VIRTUALLINK:
LIST_FOREACH(nbr, &iface->nbr_list, entry) {
if (nbr == iface->self)
continue;
if (!(nbr->state & NBR_STA_FLOOD))
continue;
send_ls_ack(iface, nbr->addr, buf);
}
break;
default:
fatalx("lsa_ack_tx_timer: unknown interface type");
}
ibuf_free(buf);
}
}
void
start_ls_ack_tx_timer(struct iface *iface)
{
struct timeval tv;
timerclear(&tv);
tv.tv_sec = iface->rxmt_interval / 2;
if (evtimer_add(&iface->lsack_tx_timer, &tv) == -1)
fatal("start_ls_ack_tx_timer");
}
void
start_ls_ack_tx_timer_now(struct iface *iface)
{
struct timeval tv;
timerclear(&tv);
if (evtimer_add(&iface->lsack_tx_timer, &tv) == -1)
fatal("start_ls_ack_tx_timer_now");
}
void
stop_ls_ack_tx_timer(struct iface *iface)
{
if (evtimer_del(&iface->lsack_tx_timer) == -1)
fatal("stop_ls_ack_tx_timer");
}
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