NetBSD/usr.sbin/rtadvd/rrenum.c

494 lines
14 KiB
C

/* $NetBSD: rrenum.c,v 1.21 2018/04/20 10:26:34 roy Exp $ */
/* $KAME: rrenum.c,v 1.14 2004/06/14 05:36:00 itojun Exp $ */
/*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/types.h>
#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <net/if.h>
#ifdef __FreeBSD__
#include <net/if_var.h>
#endif
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/icmp6.h>
#include <arpa/inet.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <syslog.h>
#include "rtadvd.h"
#include "rrenum.h"
#include "if.h"
#include "logit.h"
#include "prog_ops.h"
#define RR_ISSET_SEGNUM(segnum_bits, segnum) \
((((segnum_bits)[(segnum) >> 5]) & (1 << ((segnum) & 31))) != 0)
#define RR_SET_SEGNUM(segnum_bits, segnum) \
(((segnum_bits)[(segnum) >> 5]) |= (1 << ((segnum) & 31)))
struct rr_operation {
u_long rro_seqnum;
u_long rro_segnum_bits[8];
};
static struct rr_operation rro;
static int rr_rcvifindex;
static int rrcmd2pco[RPM_PCO_MAX] = {
0,
SIOCAIFPREFIX_IN6,
SIOCCIFPREFIX_IN6,
SIOCSGIFPREFIX_IN6
};
static int s = -1;
/*
* Check validity of a Prefix Control Operation(PCO).
* Return 0 on success, 1 on failure.
*/
static int
rr_pco_check(int len, struct rr_pco_match *rpm)
{
struct rr_pco_use *rpu, *rpulim;
int checklen;
/* rpm->rpm_len must be (4N * 3) as router-renum-05.txt */
if ((rpm->rpm_len - 3) < 0 || /* must be at least 3 */
(rpm->rpm_len - 3) & 0x3) { /* must be multiple of 4 */
logit(LOG_WARNING, "<%s> rpm_len %d is not 4N * 3",
__func__, rpm->rpm_len);
return 1;
}
/* rpm->rpm_code must be valid value */
switch (rpm->rpm_code) {
case RPM_PCO_ADD:
case RPM_PCO_CHANGE:
case RPM_PCO_SETGLOBAL:
break;
default:
logit(LOG_WARNING, "<%s> unknown rpm_code %d", __func__,
rpm->rpm_code);
return 1;
}
/* rpm->rpm_matchlen must be 0 to 128 inclusive */
if (rpm->rpm_matchlen > 128) {
logit(LOG_WARNING, "<%s> rpm_matchlen %d is over 128",
__func__, rpm->rpm_matchlen);
return 1;
}
/*
* rpu->rpu_uselen, rpu->rpu_keeplen, and sum of them must be
* between 0 and 128 inclusive
*/
for (rpu = (struct rr_pco_use *)(rpm + 1),
rpulim = (struct rr_pco_use *)((char *)rpm + len);
rpu < rpulim;
rpu += 1) {
checklen = rpu->rpu_uselen;
checklen += rpu->rpu_keeplen;
/*
* omit these check, because either of rpu_uselen
* and rpu_keeplen is unsigned char
* (128 > rpu_uselen > 0)
* (128 > rpu_keeplen > 0)
* (rpu_uselen + rpu_keeplen > 0)
*/
if (checklen > 128) {
logit(LOG_WARNING, "<%s> sum of rpu_uselen %d and"
" rpu_keeplen %d is %d(over 128)",
__func__, rpu->rpu_uselen,
rpu->rpu_keeplen,
rpu->rpu_uselen + rpu->rpu_keeplen);
return 1;
}
}
return 0;
}
static void
do_use_prefix(int len, struct rr_pco_match *rpm,
struct in6_rrenumreq *irr, int ifindex)
{
struct rr_pco_use *rpu, *rpulim;
struct rainfo *rai;
struct prefix *pp;
struct in6_addr rpm_prefix, rpu_prefix;
rpu = (struct rr_pco_use *)(rpm + 1);
rpulim = (struct rr_pco_use *)((char *)rpm + len);
if (rpu == rpulim) { /* no use prefix */
if (rpm->rpm_code == RPM_PCO_ADD)
return;
irr->irr_u_uselen = 0;
irr->irr_u_keeplen = 0;
irr->irr_raf_mask_onlink = 0;
irr->irr_raf_mask_auto = 0;
irr->irr_vltime = 0;
irr->irr_pltime = 0;
memset(&irr->irr_flags, 0, sizeof(irr->irr_flags));
irr->irr_useprefix.sin6_len = 0; /* let it mean, no addition */
irr->irr_useprefix.sin6_family = 0;
irr->irr_useprefix.sin6_addr = in6addr_any;
if (prog_ioctl(s, rrcmd2pco[rpm->rpm_code], irr) < 0 &&
errno != EADDRNOTAVAIL)
logit(LOG_ERR, "<%s> ioctl: %m", __func__);
return;
}
for (rpu = (struct rr_pco_use *)(rpm + 1),
rpulim = (struct rr_pco_use *)((char *)rpm + len);
rpu < rpulim;
rpu += 1) {
/* init in6_rrenumreq fields */
irr->irr_u_uselen = rpu->rpu_uselen;
irr->irr_u_keeplen = rpu->rpu_keeplen;
irr->irr_raf_mask_onlink =
!!(rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_ONLINK);
irr->irr_raf_mask_auto =
!!(rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_AUTO);
irr->irr_vltime = ntohl(rpu->rpu_vltime);
irr->irr_pltime = ntohl(rpu->rpu_pltime);
irr->irr_raf_onlink =
(rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_ONLINK) == 0 ? 0 : 1;
irr->irr_raf_auto =
(rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_AUTO) == 0 ? 0 : 1;
irr->irr_rrf_decrvalid =
(rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRVLTIME) == 0 ? 0 : 1;
irr->irr_rrf_decrprefd =
(rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRPLTIME) == 0 ? 0 : 1;
irr->irr_useprefix.sin6_len = sizeof(irr->irr_useprefix);
irr->irr_useprefix.sin6_family = AF_INET6;
irr->irr_useprefix.sin6_addr = rpu->rpu_prefix;
if (prog_ioctl(s, rrcmd2pco[rpm->rpm_code], irr) < 0 &&
errno != EADDRNOTAVAIL)
logit(LOG_ERR, "<%s> ioctl: %m", __func__);
/* very adhoc: should be rewritten */
memcpy(&rpm_prefix, &rpm->rpm_prefix, sizeof(rpm_prefix));
memcpy(&rpu_prefix, &rpu->rpu_prefix, sizeof(rpu_prefix));
if (rpm->rpm_code == RPM_PCO_CHANGE &&
IN6_ARE_ADDR_EQUAL(&rpm_prefix, &rpu_prefix) &&
rpm->rpm_matchlen == rpu->rpu_uselen &&
rpu->rpu_uselen == rpu->rpu_keeplen) {
if ((rai = if_indextorainfo(ifindex)) == NULL)
continue; /* non-advertising IF */
TAILQ_FOREACH(pp, &rai->prefix, next) {
struct timespec now;
if (prefix_match(&pp->prefix, pp->prefixlen,
&rpm_prefix,
rpm->rpm_matchlen)) {
/* change parameters */
pp->validlifetime = ntohl(rpu->rpu_vltime);
pp->preflifetime = ntohl(rpu->rpu_pltime);
if (irr->irr_rrf_decrvalid) {
prog_clock_gettime(CLOCK_MONOTONIC,
&now);
pp->vltimeexpire =
now.tv_sec + pp->validlifetime;
} else
pp->vltimeexpire = 0;
if (irr->irr_rrf_decrprefd) {
prog_clock_gettime(CLOCK_MONOTONIC,
&now);
pp->pltimeexpire =
now.tv_sec + pp->preflifetime;
} else
pp->pltimeexpire = 0;
}
}
}
}
}
/*
* process a Prefix Control Operation(PCO).
* return 0 on success, 1 on failure
*/
static int
do_pco(struct icmp6_router_renum *rr, int len, struct rr_pco_match *rpm)
{
int ifindex = 0;
struct in6_rrenumreq irr;
struct rainfo *rai;
if ((rr_pco_check(len, rpm) != 0))
return 1;
if (s == -1 && (s = prog_socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
logit(LOG_ERR, "<%s> socket: %m", __func__);
exit(1);
}
memset(&irr, 0, sizeof(irr));
irr.irr_origin = PR_ORIG_RR;
irr.irr_m_len = rpm->rpm_matchlen;
irr.irr_m_minlen = rpm->rpm_minlen;
irr.irr_m_maxlen = rpm->rpm_maxlen;
irr.irr_matchprefix.sin6_len = sizeof(irr.irr_matchprefix);
irr.irr_matchprefix.sin6_family = AF_INET6;
irr.irr_matchprefix.sin6_addr = rpm->rpm_prefix;
/*
* if ICMP6_RR_FLAGS_FORCEAPPLY(A flag) is 0 and IFF_UP is off,
* the interface is not applied
*/
if (rr->rr_flags & ICMP6_RR_FLAGS_FORCEAPPLY) {
while (if_indextoname(++ifindex, irr.irr_name)) {
rai = if_indextorainfo(ifindex);
if (rai && (rai->ifflags & IFF_UP)) {
/* TODO: interface scope check */
do_use_prefix(len, rpm, &irr, ifindex);
}
}
}
if (errno == ENXIO)
return 0;
else if (errno) {
logit(LOG_ERR, "<%s> if_indextoname: %m", __func__);
return 1;
}
return 0;
}
/*
* call do_pco() for each Prefix Control Operations(PCOs) in a received
* Router Renumbering Command packet.
* return 0 on success, 1 on failure
*/
static int
do_rr(size_t len, struct icmp6_router_renum *rr)
{
struct rr_pco_match *rpm;
char *cp, *lim;
lim = (char *)rr + len;
cp = (char *)(rr + 1);
len -= sizeof(struct icmp6_router_renum);
while (cp < lim) {
size_t rpmlen;
rpm = (struct rr_pco_match *)cp;
if (len < sizeof(struct rr_pco_match)) {
tooshort:
logit(LOG_ERR, "<%s> pkt too short. left len = %zd. "
"garbage at end of pkt?", __func__, len);
return 1;
}
rpmlen = rpm->rpm_len << 3;
if (len < rpmlen)
goto tooshort;
if (do_pco(rr, rpmlen, rpm)) {
logit(LOG_WARNING, "<%s> invalid PCO", __func__);
goto next;
}
next:
cp += rpmlen;
len -= rpmlen;
}
return 0;
}
/*
* check validity of a router renumbering command packet
* return 0 on success, 1 on failure
*/
static int
rr_command_check(size_t len, struct icmp6_router_renum *rr,
struct in6_addr *from, struct in6_addr *dst)
{
char ntopbuf[INET6_ADDRSTRLEN];
/* omit rr minimal length check. hope kernel have done it. */
/* rr_command length check */
if (len < (sizeof(struct icmp6_router_renum) +
sizeof(struct rr_pco_match))) {
logit(LOG_ERR, "<%s> rr_command len %zd is too short",
__func__, len);
return 1;
}
/* destination check. only for multicast. omit unicast check. */
if (IN6_IS_ADDR_MULTICAST(dst) && !IN6_IS_ADDR_MC_LINKLOCAL(dst) &&
!IN6_IS_ADDR_MC_SITELOCAL(dst)) {
logit(LOG_ERR, "<%s> dst mcast addr %s is illegal",
__func__,
inet_ntop(AF_INET6, dst, ntopbuf, INET6_ADDRSTRLEN));
return 1;
}
/* seqnum and segnum check */
if (rro.rro_seqnum > rr->rr_seqnum) {
logit(LOG_WARNING,
"<%s> rcvd old seqnum %d from %s",
__func__, (uint32_t)ntohl(rr->rr_seqnum),
inet_ntop(AF_INET6, from, ntopbuf, INET6_ADDRSTRLEN));
return 1;
}
if (rro.rro_seqnum == rr->rr_seqnum &&
(rr->rr_flags & ICMP6_RR_FLAGS_TEST) == 0 &&
RR_ISSET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum)) {
if ((rr->rr_flags & ICMP6_RR_FLAGS_REQRESULT) != 0)
logit(LOG_WARNING,
"<%s> rcvd duped segnum %d from %s",
__func__, rr->rr_segnum,
inet_ntop(AF_INET6, from, ntopbuf,
INET6_ADDRSTRLEN));
return 0;
}
/* update seqnum */
if (rro.rro_seqnum != rr->rr_seqnum) {
/* then must be "<" */
/* init rro_segnum_bits */
memset(rro.rro_segnum_bits, 0,
sizeof(rro.rro_segnum_bits));
}
rro.rro_seqnum = rr->rr_seqnum;
return 0;
}
static void
rr_command_input(int len, struct icmp6_router_renum *rr,
struct in6_addr *from, struct in6_addr *dst)
{
/* rr_command validity check */
if (rr_command_check(len, rr, from, dst))
goto failed;
if ((rr->rr_flags & (ICMP6_RR_FLAGS_TEST|ICMP6_RR_FLAGS_REQRESULT)) ==
ICMP6_RR_FLAGS_TEST)
return;
/* do router renumbering */
if (do_rr(len, rr)) {
goto failed;
}
/* update segnum */
RR_SET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum);
return;
failed:
logit(LOG_ERR, "<%s> received RR was invalid", __func__);
return;
}
void
rr_input(size_t len, struct icmp6_router_renum *rr, struct in6_pktinfo *pi,
struct sockaddr_in6 *from, struct in6_addr *dst)
{
char ntopbuf[2][INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
logit(LOG_DEBUG,
"<%s> RR received from %s to %s on %s",
__func__,
inet_ntop(AF_INET6, &from->sin6_addr,
ntopbuf[0], INET6_ADDRSTRLEN),
inet_ntop(AF_INET6, &dst, ntopbuf[1], INET6_ADDRSTRLEN),
if_indextoname(pi->ipi6_ifindex, ifnamebuf));
/* packet validation based on Section 4.1 of RFC2894 */
if (len < sizeof(struct icmp6_router_renum)) {
logit(LOG_NOTICE,
"<%s>: RR short message (size %zd) from %s to %s on %s",
__func__, len,
inet_ntop(AF_INET6, &from->sin6_addr,
ntopbuf[0], INET6_ADDRSTRLEN),
inet_ntop(AF_INET6, &dst, ntopbuf[1], INET6_ADDRSTRLEN),
if_indextoname(pi->ipi6_ifindex, ifnamebuf));
return;
}
/*
* If the IPv6 destination address is neither an All Routers multicast
* address [AARCH] nor one of the receiving router's unicast addresses,
* the message MUST be discarded and SHOULD be logged to network
* management.
* We rely on the kernel input routine for unicast addresses, and thus
* check multicast destinations only.
*/
if (IN6_IS_ADDR_MULTICAST(&pi->ipi6_addr) &&
!IN6_ARE_ADDR_EQUAL(&sin6_sitelocal_allrouters.sin6_addr,
&pi->ipi6_addr))
{
logit(LOG_NOTICE,
"<%s>: RR message with invalid destination (%s) "
"from %s on %s",
__func__,
inet_ntop(AF_INET6, &dst, ntopbuf[0], INET6_ADDRSTRLEN),
inet_ntop(AF_INET6, &from->sin6_addr,
ntopbuf[1], INET6_ADDRSTRLEN),
if_indextoname(pi->ipi6_ifindex, ifnamebuf));
return;
}
rr_rcvifindex = pi->ipi6_ifindex;
switch (rr->rr_code) {
case ICMP6_ROUTER_RENUMBERING_COMMAND:
rr_command_input(len, rr, &from->sin6_addr, dst);
/* TODO: send reply msg */
break;
case ICMP6_ROUTER_RENUMBERING_RESULT:
/* RESULT will be processed by rrenumd */
break;
case ICMP6_ROUTER_RENUMBERING_SEQNUM_RESET:
/* TODO: sequence number reset */
break;
default:
logit(LOG_ERR, "<%s> received unknown code %d",
__func__, rr->rr_code);
break;
}
return;
}