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/* $OpenBSD: hello.c,v 1.22 2018/02/22 07:42:38 claudio Exp $ */
/*
* Copyright (c) 2005 Claudio Jeker <claudio@openbsd.org>
* Copyright (c) 2004, 2005 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 <arpa/inet.h>
#include <sys/time.h>
#include <stdlib.h>
#include <string.h>
#include <event.h>
#include "ospfd.h"
#include "ospf.h"
#include "log.h"
#include "ospfe.h"
extern struct ospfd_conf *oeconf;
/* hello packet handling */
int
send_hello(struct iface *iface)
{
struct sockaddr_in dst;
struct hello_hdr hello;
struct nbr *nbr;
struct ibuf *buf;
int ret;
dst.sin_family = AF_INET;
dst.sin_len = sizeof(struct sockaddr_in);
switch (iface->type) {
case IF_TYPE_POINTOPOINT:
case IF_TYPE_BROADCAST:
inet_aton(AllSPFRouters, &dst.sin_addr);
break;
case IF_TYPE_NBMA:
case IF_TYPE_POINTOMULTIPOINT:
log_debug("send_hello: type %s not supported, interface %s",
if_type_name(iface->type), iface->name);
return (-1);
case IF_TYPE_VIRTUALLINK:
dst.sin_addr = iface->dst;
break;
default:
fatalx("send_hello: unknown interface type");
}
if ((buf = ibuf_dynamic(PKG_DEF_SIZE,
IP_MAXPACKET - sizeof(struct ip))) == NULL)
fatal("send_hello");
/* OSPF header */
if (gen_ospf_hdr(buf, iface, PACKET_TYPE_HELLO))
goto fail;
/* hello header */
hello.mask = iface->mask.s_addr;
hello.hello_interval = htons(iface->hello_interval);
hello.opts = area_ospf_options(iface->area);
hello.rtr_priority = iface->priority;
hello.rtr_dead_interval = htonl(iface->dead_interval);
if (iface->dr) {
hello.d_rtr = iface->dr->addr.s_addr;
iface->self->dr.s_addr = iface->dr->addr.s_addr;
} else
hello.d_rtr = 0;
if (iface->bdr) {
hello.bd_rtr = iface->bdr->addr.s_addr;
iface->self->bdr.s_addr = iface->bdr->addr.s_addr;
} else
hello.bd_rtr = 0;
if (ibuf_add(buf, &hello, sizeof(hello)))
goto fail;
/* active neighbor(s) */
LIST_FOREACH(nbr, &iface->nbr_list, entry) {
if ((nbr->state >= NBR_STA_INIT) && (nbr != iface->self))
if (ibuf_add(buf, &nbr->id, sizeof(nbr->id)))
goto fail;
}
/* update authentication and calculate checksum */
if (auth_gen(buf, iface))
goto fail;
ret = send_packet(iface, buf, &dst);
ibuf_free(buf);
return (ret);
fail:
log_warn("send_hello");
ibuf_free(buf);
return (-1);
}
void
recv_hello(struct iface *iface, struct in_addr src, u_int32_t rtr_id, char *buf,
u_int16_t len)
{
struct hello_hdr hello;
struct nbr *nbr = NULL, *dr;
u_int32_t nbr_id;
int nbr_change = 0;
if (len < sizeof(hello) || (len & 0x03)) {
log_warnx("recv_hello: bad packet size, interface %s",
iface->name);
return;
}
memcpy(&hello, buf, sizeof(hello));
buf += sizeof(hello);
len -= sizeof(hello);
if (iface->type != IF_TYPE_POINTOPOINT &&
iface->type != IF_TYPE_VIRTUALLINK)
if (hello.mask != iface->mask.s_addr) {
log_warnx("recv_hello: invalid netmask, interface %s",
iface->name);
return;
}
if (ntohs(hello.hello_interval) != iface->hello_interval) {
log_warnx("recv_hello: invalid hello-interval %d, "
"interface %s", ntohs(hello.hello_interval),
iface->name);
return;
}
if (ntohl(hello.rtr_dead_interval) != iface->dead_interval) {
log_warnx("recv_hello: invalid router-dead-interval %d, "
"interface %s", ntohl(hello.rtr_dead_interval),
iface->name);
return;
}
if ((hello.opts & OSPF_OPTION_E && iface->area->stub) ||
((hello.opts & OSPF_OPTION_E) == 0 && !iface->area->stub)) {
log_warnx("recv_hello: ExternalRoutingCapability mismatch, "
"interface %s", iface->name);
return;
}
/*
* Match router-id, in case of conflict moan and ignore hello.
* Only the router-id is compared since the source IP on NBMA,
* broadcast and point-to-multipoint interfaces was already
* compared in find_iface() and only IPs in the same subnet
* are accepted. This is not excatly what the RFC specifies
* but works far better.
*/
LIST_FOREACH(nbr, &iface->nbr_list, entry) {
if (nbr == iface->self) {
if (nbr->id.s_addr == rtr_id) {
log_warnx("recv_hello: Router-ID collision on "
"interface %s neighbor IP %s", iface->name,
inet_ntoa(src));
return;
}
continue;
}
if (nbr->id.s_addr == rtr_id)
break;
}
if (!nbr) {
nbr = nbr_new(rtr_id, iface, 0);
/* set neighbor parameters */
nbr->dr.s_addr = hello.d_rtr;
nbr->bdr.s_addr = hello.bd_rtr;
nbr->priority = hello.rtr_priority;
}
/* actually the neighbor address shouldn't be stored on virtual links */
nbr->addr.s_addr = src.s_addr;
nbr->options = hello.opts;
nbr_fsm(nbr, NBR_EVT_HELLO_RCVD);
while (len >= sizeof(nbr_id)) {
memcpy(&nbr_id, buf, sizeof(nbr_id));
if (nbr_id == ospfe_router_id()) {
/* seen myself */
if (nbr->state & NBR_STA_PRELIM) {
nbr_fsm(nbr, NBR_EVT_2_WAY_RCVD);
nbr_change = 1;
}
break;
}
buf += sizeof(nbr_id);
len -= sizeof(nbr_id);
}
if (len == 0) {
nbr_fsm(nbr, NBR_EVT_1_WAY_RCVD);
/* set neighbor parameters */
nbr->dr.s_addr = hello.d_rtr;
nbr->bdr.s_addr = hello.bd_rtr;
nbr->priority = hello.rtr_priority;
return;
}
if (nbr->priority != hello.rtr_priority) {
nbr->priority = hello.rtr_priority;
nbr_change = 1;
}
if (iface->state & IF_STA_WAITING &&
hello.d_rtr == nbr->addr.s_addr && hello.bd_rtr == 0)
if_fsm(iface, IF_EVT_BACKUP_SEEN);
if (iface->state & IF_STA_WAITING && hello.bd_rtr == nbr->addr.s_addr) {
/*
* In case we see the BDR make sure that the DR is around
* with a bidirectional (2_WAY or better) connection
*/
LIST_FOREACH(dr, &iface->nbr_list, entry)
if (hello.d_rtr == dr->addr.s_addr &&
dr->state & NBR_STA_BIDIR)
if_fsm(iface, IF_EVT_BACKUP_SEEN);
}
if ((nbr->addr.s_addr == nbr->dr.s_addr &&
nbr->addr.s_addr != hello.d_rtr) ||
(nbr->addr.s_addr != nbr->dr.s_addr &&
nbr->addr.s_addr == hello.d_rtr))
/* neighbor changed from or to DR */
nbr_change = 1;
if ((nbr->addr.s_addr == nbr->bdr.s_addr &&
nbr->addr.s_addr != hello.bd_rtr) ||
(nbr->addr.s_addr != nbr->bdr.s_addr &&
nbr->addr.s_addr == hello.bd_rtr))
/* neighbor changed from or to BDR */
nbr_change = 1;
nbr->dr.s_addr = hello.d_rtr;
nbr->bdr.s_addr = hello.bd_rtr;
if (nbr_change)
if_fsm(iface, IF_EVT_NBR_CHNG);
/* TODO NBMA needs some special handling */
}
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