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/* $OpenBSD: packet.c,v 1.3 2014/10/25 03:23:49 lteo Exp $ */
/*
* Copyright (c) 2004, 2005, 2006 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 <sys/time.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/ip_mroute.h>
#include <arpa/inet.h>
#include <errno.h>
#include <event.h>
#include <stdlib.h>
#include <strings.h>
#include "igmp.h"
#include "dvmrpd.h"
#include "dvmrp.h"
#include "log.h"
#include "dvmrpe.h"
int ip_hdr_sanity_check(const struct ip *, u_int16_t);
int dvmrp_hdr_sanity_check(const struct ip *, struct dvmrp_hdr *,
u_int16_t, const struct iface *);
struct iface *find_iface(struct dvmrpd_conf *, struct in_addr);
extern struct dvmrpd_conf *deconf;
int
gen_dvmrp_hdr(struct ibuf *buf, struct iface *iface, u_int8_t code)
{
struct dvmrp_hdr dvmrp_hdr;
bzero(&dvmrp_hdr, sizeof(dvmrp_hdr));
dvmrp_hdr.type = PKT_TYPE_DVMRP;
dvmrp_hdr.code = code;
dvmrp_hdr.chksum = 0; /* updated later */
dvmrp_hdr.capabilities = DVMRP_CAP_DEFAULT; /* XXX update */
dvmrp_hdr.minor_version = DVMRP_MINOR_VERSION;
dvmrp_hdr.major_version = DVMRP_MAJOR_VERSION;
return (ibuf_add(buf, &dvmrp_hdr, sizeof(dvmrp_hdr)));
}
/* send and receive packets */
int
send_packet(struct iface *iface, void *pkt, size_t len, struct sockaddr_in *dst)
{
if (iface->passive) {
log_warnx("send_packet: cannot send packet on passive "
"interface %s", iface->name);
return (-1);
}
/* set outgoing interface for multicast traffic */
if (IN_MULTICAST(ntohl(dst->sin_addr.s_addr)))
if (if_set_mcast(iface) == -1) {
log_warn("send_packet: error setting multicast "
"interface, %s", iface->name);
return (-1);
}
if (sendto(iface->fd, pkt, len, 0,
(struct sockaddr *)dst, sizeof(*dst)) == -1 ) {
log_warn("send_packet: error sending packet on interface %s",
iface->name);
return (-1);
}
return (0);
}
void
recv_packet(int fd, short event, void *bula)
{
struct dvmrpd_conf *xconf = bula;
struct ip ip_hdr;
struct dvmrp_hdr *dvmrp_hdr;
struct iface *iface;
struct nbr *nbr = NULL;
struct in_addr addr;
char *buf;
ssize_t r;
u_int16_t len;
int l;
if (event != EV_READ)
return;
/* setup buffer */
buf = pkt_ptr;
if ((r = recvfrom(fd, buf, IBUF_READ_SIZE, 0, NULL, NULL)) == -1) {
if (errno != EAGAIN && errno != EINTR)
log_debug("recv_packet: error receiving packet");
return;
}
len = (u_int16_t)r;
/* IP header sanity checks */
if (len < sizeof(ip_hdr)) {
log_warnx("recv_packet: bad packet size");
return;
}
memcpy(&ip_hdr, buf, sizeof(ip_hdr));
if ((l = ip_hdr_sanity_check(&ip_hdr, len)) == -1)
return;
buf += l;
len -= l;
/* find a matching interface */
if ((iface = find_iface(xconf, ip_hdr.ip_src)) == NULL) {
log_debug("recv_packet: cannot find valid interface, ip src %s",
inet_ntoa(ip_hdr.ip_src));
return;
}
/* header sanity checks */
if (len < sizeof(*dvmrp_hdr)) {
log_warnx("recv_packet: bad packet size");
return;
}
dvmrp_hdr = (struct dvmrp_hdr *)buf;
switch (dvmrp_hdr->type) {
/* DVMRP */
case PKT_TYPE_DVMRP:
if ((l = dvmrp_hdr_sanity_check(&ip_hdr, dvmrp_hdr, len,
iface)) == -1)
return;
/*
* mrouted compat
*
* Old mrouted versions, send route reports before establishing
* 2-WAY neighbor relationships.
*/
if ((nbr_find_ip(iface, ip_hdr.ip_src.s_addr) == NULL) &&
(dvmrp_hdr->code == DVMRP_CODE_REPORT)) {
log_debug("recv_packet: route report from neighbor"
" ID %s, compat", inet_ntoa(ip_hdr.ip_src));
nbr = nbr_new(ip_hdr.ip_src.s_addr, iface, 0);
nbr_fsm(nbr, NBR_EVT_PROBE_RCVD);
nbr->compat = 1;
nbr->addr = ip_hdr.ip_src;
}
if ((dvmrp_hdr->type == PKT_TYPE_DVMRP) &&
(dvmrp_hdr->code != DVMRP_CODE_PROBE))
/* find neighbor */
if ((nbr = nbr_find_ip(iface, ip_hdr.ip_src.s_addr))
== NULL) {
log_debug("recv_packet: unknown neighbor ID");
return;
}
buf += sizeof(*dvmrp_hdr);
len = l - sizeof(*dvmrp_hdr);
inet_aton(AllDVMRPRouters, &addr);
if ((ip_hdr.ip_dst.s_addr != addr.s_addr) &&
(ip_hdr.ip_dst.s_addr != iface->addr.s_addr)) {
log_debug("recv_packet: interface %s, invalid"
" destination IP address %s", iface->name,
inet_ntoa(ip_hdr.ip_dst));
break;
}
switch (dvmrp_hdr->code) {
case DVMRP_CODE_PROBE:
recv_probe(iface, ip_hdr.ip_src, ip_hdr.ip_src.s_addr,
dvmrp_hdr->capabilities, buf, len);
break;
case DVMRP_CODE_REPORT:
recv_report(nbr, buf, len);
break;
case DVMRP_CODE_ASK_NBRS2:
recv_ask_nbrs2(nbr, buf,len);
break;
case DVMRP_CODE_NBRS2:
recv_nbrs2(nbr, buf,len);
break;
case DVMRP_CODE_PRUNE:
recv_prune(nbr, buf, len);
break;
case DVMRP_CODE_GRAFT:
recv_graft(nbr, buf,len);
break;
case DVMRP_CODE_GRAFT_ACK:
recv_graft_ack(nbr, buf,len);
break;
default:
log_debug("recv_packet: unknown DVMRP packet type, "
"interface %s", iface->name);
}
break;
/* IGMP */
case PKT_TYPE_MEMBER_QUERY:
recv_igmp_query(iface, ip_hdr.ip_src, buf, len);
break;
case PKT_TYPE_MEMBER_REPORTv1:
case PKT_TYPE_MEMBER_REPORTv2:
recv_igmp_report(iface, ip_hdr.ip_src, buf, len,
dvmrp_hdr->type);
break;
case PKT_TYPE_LEAVE_GROUPv2:
recv_igmp_leave(iface, ip_hdr.ip_src, buf, len);
break;
default:
log_debug("recv_packet: unknown IGMP packet type, interface %s",
iface->name);
}
}
int
ip_hdr_sanity_check(const struct ip *ip_hdr, u_int16_t len)
{
if (ntohs(ip_hdr->ip_len) != len) {
log_debug("recv_packet: invalid IP packet length %u",
ntohs(ip_hdr->ip_len));
return (-1);
}
if (ip_hdr->ip_p != IPPROTO_IGMP)
/* this is enforced by the socket itself */
fatalx("recv_packet: invalid IP proto");
return (ip_hdr->ip_hl << 2);
}
int
dvmrp_hdr_sanity_check(const struct ip *ip_hdr, struct dvmrp_hdr *dvmrp_hdr,
u_int16_t len, const struct iface *iface)
{
/* we only support DVMRPv3 */
if (dvmrp_hdr->major_version != DVMRP_MAJOR_VERSION) {
log_debug("recv_packet: invalid DVMRP version");
return (-1);
}
/* XXX enforce minor version as well, but not yet */
/* XXX chksum */
return (len);
}
struct iface *
find_iface(struct dvmrpd_conf *xconf, struct in_addr src)
{
struct iface *iface = NULL;
/* returned interface needs to be active */
LIST_FOREACH(iface, &xconf->iface_list, entry) {
if (iface->fd > 0 &&
(iface->type == IF_TYPE_POINTOPOINT) &&
(iface->dst.s_addr == src.s_addr) &&
!iface->passive)
return (iface);
if (iface->fd > 0 && (iface->addr.s_addr &
iface->mask.s_addr) == (src.s_addr &
iface->mask.s_addr) && !iface->passive)
return (iface);
}
return (NULL);
}
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