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833d853cbf
freebsd-dev/usr.sbin/rtadvd/rtadvd.c
Hiroki Sato 833d853cbf Fix SIGSEGV when set_short_delay() is called when ifi->ifi_ra_timer is NULL. 
This can happen in a short period when a prefix is changed by a rtmsg and a
new interface arrives.
2013-03-06 04:58:48 +00:00

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49 KiB
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/* $FreeBSD$ */
/* $KAME: rtadvd.c,v 1.82 2003/08/05 12:34:23 itojun Exp $ */
/*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* Copyright (C) 2011 Hiroki Sato <hrs@FreeBSD.org>
* 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/param.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <sys/time.h>
#include <sys/queue.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/if_types.h>
#include <net/if_media.h>
#include <net/if_dl.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet/icmp6.h>
#include <arpa/inet.h>
#include <net/if_var.h>
#include <netinet/in_var.h>
#include <netinet6/nd6.h>
#include <time.h>
#include <unistd.h>
#include <stdio.h>
#include <err.h>
#include <errno.h>
#include <inttypes.h>
#include <libutil.h>
#include <netdb.h>
#include <signal.h>
#include <string.h>
#include <stdlib.h>
#include <syslog.h>
#include <poll.h>
#include "pathnames.h"
#include "rtadvd.h"
#include "if.h"
#include "rrenum.h"
#include "advcap.h"
#include "timer_subr.h"
#include "timer.h"
#include "config.h"
#include "control.h"
#include "control_server.h"
#define RTADV_TYPE2BITMASK(type) (0x1 << type)
struct msghdr rcvmhdr;
static char *rcvcmsgbuf;
static size_t rcvcmsgbuflen;
static char *sndcmsgbuf = NULL;
static size_t sndcmsgbuflen;
struct msghdr sndmhdr;
struct iovec rcviov[2];
struct iovec sndiov[2];
struct sockaddr_in6 rcvfrom;
static const char *pidfilename = _PATH_RTADVDPID;
const char *conffile = _PATH_RTADVDCONF;
static struct pidfh *pfh;
int dflag = 0, sflag = 0;
static int wait_shutdown;
#define PFD_RAWSOCK 0
#define PFD_RTSOCK 1
#define PFD_CSOCK 2
#define PFD_MAX 3
struct railist_head_t railist =
TAILQ_HEAD_INITIALIZER(railist);
struct ifilist_head_t ifilist =
TAILQ_HEAD_INITIALIZER(ifilist);
struct nd_optlist {
TAILQ_ENTRY(nd_optlist) nol_next;
struct nd_opt_hdr *nol_opt;
};
union nd_opt {
struct nd_opt_hdr *opt_array[9];
struct {
struct nd_opt_hdr *zero;
struct nd_opt_hdr *src_lladdr;
struct nd_opt_hdr *tgt_lladdr;
struct nd_opt_prefix_info *pi;
struct nd_opt_rd_hdr *rh;
struct nd_opt_mtu *mtu;
TAILQ_HEAD(, nd_optlist) opt_list;
} nd_opt_each;
};
#define opt_src_lladdr nd_opt_each.src_lladdr
#define opt_tgt_lladdr nd_opt_each.tgt_lladdr
#define opt_pi nd_opt_each.pi
#define opt_rh nd_opt_each.rh
#define opt_mtu nd_opt_each.mtu
#define opt_list nd_opt_each.opt_list
#define NDOPT_FLAG_SRCLINKADDR (1 << 0)
#define NDOPT_FLAG_TGTLINKADDR (1 << 1)
#define NDOPT_FLAG_PREFIXINFO (1 << 2)
#define NDOPT_FLAG_RDHDR (1 << 3)
#define NDOPT_FLAG_MTU (1 << 4)
#define NDOPT_FLAG_RDNSS (1 << 5)
#define NDOPT_FLAG_DNSSL (1 << 6)
uint32_t ndopt_flags[] = {
[ND_OPT_SOURCE_LINKADDR] = NDOPT_FLAG_SRCLINKADDR,
[ND_OPT_TARGET_LINKADDR] = NDOPT_FLAG_TGTLINKADDR,
[ND_OPT_PREFIX_INFORMATION] = NDOPT_FLAG_PREFIXINFO,
[ND_OPT_REDIRECTED_HEADER] = NDOPT_FLAG_RDHDR,
[ND_OPT_MTU] = NDOPT_FLAG_MTU,
[ND_OPT_RDNSS] = NDOPT_FLAG_RDNSS,
[ND_OPT_DNSSL] = NDOPT_FLAG_DNSSL,
};
static void rtadvd_shutdown(void);
static void sock_open(struct sockinfo *);
static void rtsock_open(struct sockinfo *);
static void rtadvd_input(struct sockinfo *);
static void rs_input(int, struct nd_router_solicit *,
struct in6_pktinfo *, struct sockaddr_in6 *);
static void ra_input(int, struct nd_router_advert *,
struct in6_pktinfo *, struct sockaddr_in6 *);
static int prefix_check(struct nd_opt_prefix_info *, struct rainfo *,
struct sockaddr_in6 *);
static int nd6_options(struct nd_opt_hdr *, int,
union nd_opt *, uint32_t);
static void free_ndopts(union nd_opt *);
static void rtmsg_input(struct sockinfo *);
static void set_short_delay(struct ifinfo *);
static int check_accept_rtadv(int);
static void
usage(void)
{
fprintf(stderr, "usage: rtadvd [-dDfRs] "
"[-c configfile] [-C ctlsock] [-M ifname] [-p pidfile]\n");
exit(1);
}
int
main(int argc, char *argv[])
{
struct pollfd set[PFD_MAX];
struct timeval *timeout;
int i, ch;
int fflag = 0, logopt;
int error;
pid_t pid, otherpid;
/* get command line options and arguments */
while ((ch = getopt(argc, argv, "c:C:dDfhM:p:Rs")) != -1) {
switch (ch) {
case 'c':
conffile = optarg;
break;
case 'C':
ctrlsock.si_name = optarg;
break;
case 'd':
dflag++;
break;
case 'D':
dflag += 3;
break;
case 'f':
fflag = 1;
break;
case 'M':
mcastif = optarg;
break;
case 'R':
fprintf(stderr, "rtadvd: "
"the -R option is currently ignored.\n");
/* accept_rr = 1; */
/* run anyway... */
break;
case 's':
sflag = 1;
break;
case 'p':
pidfilename = optarg;
break;
default:
usage();
}
}
argc -= optind;
argv += optind;
logopt = LOG_NDELAY | LOG_PID;
if (fflag)
logopt |= LOG_PERROR;
openlog("rtadvd", logopt, LOG_DAEMON);
/* set log level */
if (dflag > 2)
(void)setlogmask(LOG_UPTO(LOG_DEBUG));
else if (dflag > 1)
(void)setlogmask(LOG_UPTO(LOG_INFO));
else if (dflag > 0)
(void)setlogmask(LOG_UPTO(LOG_NOTICE));
else
(void)setlogmask(LOG_UPTO(LOG_ERR));
/* timer initialization */
rtadvd_timer_init();
#ifndef HAVE_ARC4RANDOM
/* random value initialization */
#ifdef __FreeBSD__
srandomdev();
#else
srandom((unsigned long)time(NULL));
#endif
#endif
pfh = pidfile_open(pidfilename, 0600, &otherpid);
if (pfh == NULL) {
if (errno == EEXIST)
errx(1, "%s already running, pid: %d",
getprogname(), otherpid);
syslog(LOG_ERR,
"failed to open the pid file %s, run anyway.",
pidfilename);
}
if (!fflag)
daemon(1, 0);
sock_open(&sock);
update_ifinfo(&ifilist, UPDATE_IFINFO_ALL);
for (i = 0; i < argc; i++)
update_persist_ifinfo(&ifilist, argv[i]);
csock_open(&ctrlsock, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
if (ctrlsock.si_fd == -1) {
syslog(LOG_ERR, "cannot open control socket: %s",
strerror(errno));
exit(1);
}
/* record the current PID */
pid = getpid();
pidfile_write(pfh);
set[PFD_RAWSOCK].fd = sock.si_fd;
set[PFD_RAWSOCK].events = POLLIN;
if (sflag == 0) {
rtsock_open(&rtsock);
set[PFD_RTSOCK].fd = rtsock.si_fd;
set[PFD_RTSOCK].events = POLLIN;
} else
set[PFD_RTSOCK].fd = -1;
set[PFD_CSOCK].fd = ctrlsock.si_fd;
set[PFD_CSOCK].events = POLLIN;
signal(SIGTERM, set_do_shutdown);
signal(SIGINT, set_do_shutdown);
signal(SIGHUP, set_do_reload);
error = csock_listen(&ctrlsock);
if (error) {
syslog(LOG_ERR, "cannot listen control socket: %s",
strerror(errno));
exit(1);
}
/* load configuration file */
set_do_reload(0);
while (1) {
if (is_do_shutdown())
rtadvd_shutdown();
if (is_do_reload()) {
loadconfig_ifname(reload_ifname());
if (reload_ifname() == NULL)
syslog(LOG_INFO,
"configuration file reloaded.");
else
syslog(LOG_INFO,
"configuration file for %s reloaded.",
reload_ifname());
reset_do_reload();
}
/* timeout handler update for active interfaces */
rtadvd_update_timeout_handler();
/* timer expiration check and reset the timer */
timeout = rtadvd_check_timer();
if (timeout != NULL) {
syslog(LOG_DEBUG,
"<%s> set timer to %ld:%ld. waiting for "
"inputs or timeout", __func__,
(long int)timeout->tv_sec,
(long int)timeout->tv_usec);
} else {
syslog(LOG_DEBUG,
"<%s> there's no timer. waiting for inputs",
__func__);
}
if ((i = poll(set, sizeof(set)/sizeof(set[0]),
timeout ? (timeout->tv_sec * 1000 +
timeout->tv_usec / 1000) : INFTIM)) < 0) {
/* EINTR would occur if a signal was delivered */
if (errno != EINTR)
syslog(LOG_ERR, "poll() failed: %s",
strerror(errno));
continue;
}
if (i == 0) /* timeout */
continue;
if (rtsock.si_fd != -1 && set[PFD_RTSOCK].revents & POLLIN)
rtmsg_input(&rtsock);
if (set[PFD_RAWSOCK].revents & POLLIN)
rtadvd_input(&sock);
if (set[PFD_CSOCK].revents & POLLIN) {
int fd;
fd = csock_accept(&ctrlsock);
if (fd == -1)
syslog(LOG_ERR,
"cannot accept() control socket: %s",
strerror(errno));
else {
cm_handler_server(fd);
close(fd);
}
}
}
exit(0); /* NOTREACHED */
}
static void
rtadvd_shutdown(void)
{
struct ifinfo *ifi;
struct rainfo *rai;
struct rdnss *rdn;
struct dnssl *dns;
if (wait_shutdown) {
syslog(LOG_INFO,
"waiting expiration of the all RA timers.");
TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
/*
* Ignore !IFF_UP interfaces in waiting for shutdown.
*/
if (!(ifi->ifi_flags & IFF_UP) &&
ifi->ifi_ra_timer != NULL) {
ifi->ifi_state = IFI_STATE_UNCONFIGURED;
rtadvd_remove_timer(ifi->ifi_ra_timer);
ifi->ifi_ra_timer = NULL;
syslog(LOG_DEBUG, "<%s> %s(idx=%d) is down. "
"Timer removed and marked as UNCONFIGURED.",
__func__, ifi->ifi_ifname,
ifi->ifi_ifindex);
}
}
TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
if (ifi->ifi_ra_timer != NULL)
break;
}
if (ifi == NULL) {
syslog(LOG_NOTICE, "gracefully terminated.");
exit(0);
}
sleep(1);
return;
}
syslog(LOG_DEBUG, "<%s> cease to be an advertising router",
__func__);
wait_shutdown = 1;
TAILQ_FOREACH(rai, &railist, rai_next) {
rai->rai_lifetime = 0;
TAILQ_FOREACH(rdn, &rai->rai_rdnss, rd_next)
rdn->rd_ltime = 0;
TAILQ_FOREACH(dns, &rai->rai_dnssl, dn_next)
dns->dn_ltime = 0;
}
TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
if (!ifi->ifi_persist)
continue;
if (ifi->ifi_state == IFI_STATE_UNCONFIGURED)
continue;
if (ifi->ifi_ra_timer == NULL)
continue;
if (ifi->ifi_ra_lastsent.tv_sec == 0 &&
ifi->ifi_ra_lastsent.tv_usec == 0 &&
ifi->ifi_ra_timer != NULL) {
/*
* When RA configured but never sent,
* ignore the IF immediately.
*/
rtadvd_remove_timer(ifi->ifi_ra_timer);
ifi->ifi_ra_timer = NULL;
ifi->ifi_state = IFI_STATE_UNCONFIGURED;
continue;
}
ifi->ifi_state = IFI_STATE_TRANSITIVE;
/* Mark as the shut-down state. */
ifi->ifi_rainfo_trans = ifi->ifi_rainfo;
ifi->ifi_rainfo = NULL;
ifi->ifi_burstcount = MAX_FINAL_RTR_ADVERTISEMENTS;
ifi->ifi_burstinterval = MIN_DELAY_BETWEEN_RAS;
ra_timer_update(ifi, &ifi->ifi_ra_timer->rat_tm);
rtadvd_set_timer(&ifi->ifi_ra_timer->rat_tm,
ifi->ifi_ra_timer);
}
syslog(LOG_NOTICE, "final RA transmission started.");
pidfile_remove(pfh);
csock_close(&ctrlsock);
}
static void
rtmsg_input(struct sockinfo *s)
{
int n, type, ifindex = 0, plen;
size_t len;
char msg[2048], *next, *lim;
char ifname[IFNAMSIZ];
struct if_announcemsghdr *ifan;
struct rt_msghdr *rtm;
struct prefix *pfx;
struct rainfo *rai;
struct in6_addr *addr;
struct ifinfo *ifi;
char addrbuf[INET6_ADDRSTRLEN];
int prefixchange = 0;
if (s == NULL) {
syslog(LOG_ERR, "<%s> internal error", __func__);
exit(1);
}
n = read(s->si_fd, msg, sizeof(msg));
rtm = (struct rt_msghdr *)msg;
syslog(LOG_DEBUG, "<%s> received a routing message "
"(type = %d, len = %d)", __func__, rtm->rtm_type, n);
if (n > rtm->rtm_msglen) {
/*
* This usually won't happen for messages received on
* a routing socket.
*/
syslog(LOG_DEBUG,
"<%s> received data length is larger than "
"1st routing message len. multiple messages? "
"read %d bytes, but 1st msg len = %d",
__func__, n, rtm->rtm_msglen);
#if 0
/* adjust length */
n = rtm->rtm_msglen;
#endif
}
lim = msg + n;
for (next = msg; next < lim; next += len) {
int oldifflags;
next = get_next_msg(next, lim, 0, &len,
RTADV_TYPE2BITMASK(RTM_ADD) |
RTADV_TYPE2BITMASK(RTM_DELETE) |
RTADV_TYPE2BITMASK(RTM_NEWADDR) |
RTADV_TYPE2BITMASK(RTM_DELADDR) |
RTADV_TYPE2BITMASK(RTM_IFINFO) |
RTADV_TYPE2BITMASK(RTM_IFANNOUNCE));
if (len == 0)
break;
type = ((struct rt_msghdr *)next)->rtm_type;
switch (type) {
case RTM_ADD:
case RTM_DELETE:
ifindex = get_rtm_ifindex(next);
break;
case RTM_NEWADDR:
case RTM_DELADDR:
ifindex = (int)((struct ifa_msghdr *)next)->ifam_index;
break;
case RTM_IFINFO:
ifindex = (int)((struct if_msghdr *)next)->ifm_index;
break;
case RTM_IFANNOUNCE:
ifan = (struct if_announcemsghdr *)next;
switch (ifan->ifan_what) {
case IFAN_ARRIVAL:
case IFAN_DEPARTURE:
break;
default:
syslog(LOG_DEBUG,
"<%s:%d> unknown ifan msg (ifan_what=%d)",
__func__, __LINE__, ifan->ifan_what);
continue;
}
syslog(LOG_DEBUG, "<%s>: if_announcemsg (idx=%d:%d)",
__func__, ifan->ifan_index, ifan->ifan_what);
switch (ifan->ifan_what) {
case IFAN_ARRIVAL:
syslog(LOG_NOTICE,
"interface added (idx=%d)",
ifan->ifan_index);
update_ifinfo(&ifilist, ifan->ifan_index);
loadconfig_index(ifan->ifan_index);
break;
case IFAN_DEPARTURE:
syslog(LOG_NOTICE,
"interface removed (idx=%d)",
ifan->ifan_index);
rm_ifinfo_index(ifan->ifan_index);
/* Clear ifi_ifindex */
TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
if (ifi->ifi_ifindex
== ifan->ifan_index) {
ifi->ifi_ifindex = 0;
break;
}
}
update_ifinfo(&ifilist, ifan->ifan_index);
break;
}
continue;
default:
/* should not reach here */
syslog(LOG_DEBUG,
"<%s:%d> unknown rtmsg %d on %s",
__func__, __LINE__, type,
if_indextoname(ifindex, ifname));
continue;
}
ifi = if_indextoifinfo(ifindex);
if (ifi == NULL) {
syslog(LOG_DEBUG,
"<%s> ifinfo not found for idx=%d. Why?",
__func__, ifindex);
continue;
}
rai = ifi->ifi_rainfo;
if (rai == NULL) {
syslog(LOG_DEBUG,
"<%s> route changed on "
"non advertising interface(%s)",
__func__, ifi->ifi_ifname);
continue;
}
oldifflags = ifi->ifi_flags;
/* init ifflags because it may have changed */
update_ifinfo(&ifilist, ifindex);
switch (type) {
case RTM_ADD:
if (sflag)
break; /* we aren't interested in prefixes */
addr = get_addr(msg);
plen = get_prefixlen(msg);
/* sanity check for plen */
/* as RFC2373, prefixlen is at least 4 */
if (plen < 4 || plen > 127) {
syslog(LOG_INFO, "<%s> new interface route's"
"plen %d is invalid for a prefix",
__func__, plen);
break;
}
pfx = find_prefix(rai, addr, plen);
if (pfx) {
if (pfx->pfx_timer) {
/*
* If the prefix has been invalidated,
* make it available again.
*/
update_prefix(pfx);
prefixchange = 1;
} else
syslog(LOG_DEBUG,
"<%s> new prefix(%s/%d) "
"added on %s, "
"but it was already in list",
__func__,
inet_ntop(AF_INET6, addr,
(char *)addrbuf,
sizeof(addrbuf)),
plen, ifi->ifi_ifname);
break;
}
make_prefix(rai, ifindex, addr, plen);
prefixchange = 1;
break;
case RTM_DELETE:
if (sflag)
break;
addr = get_addr(msg);
plen = get_prefixlen(msg);
/* sanity check for plen */
/* as RFC2373, prefixlen is at least 4 */
if (plen < 4 || plen > 127) {
syslog(LOG_INFO,
"<%s> deleted interface route's "
"plen %d is invalid for a prefix",
__func__, plen);
break;
}
pfx = find_prefix(rai, addr, plen);
if (pfx == NULL) {
syslog(LOG_DEBUG,
"<%s> prefix(%s/%d) was deleted on %s, "
"but it was not in list",
__func__, inet_ntop(AF_INET6, addr,
(char *)addrbuf, sizeof(addrbuf)),
plen, ifi->ifi_ifname);
break;
}
invalidate_prefix(pfx);
prefixchange = 1;
break;
case RTM_NEWADDR:
case RTM_DELADDR:
case RTM_IFINFO:
break;
default:
/* should not reach here */
syslog(LOG_DEBUG,
"<%s:%d> unknown rtmsg %d on %s",
__func__, __LINE__, type,
if_indextoname(ifindex, ifname));
return;
}
/* check if an interface flag is changed */
if ((oldifflags & IFF_UP) && /* UP to DOWN */
!(ifi->ifi_flags & IFF_UP)) {
syslog(LOG_NOTICE,
"<interface %s becomes down. stop timer.",
ifi->ifi_ifname);
rtadvd_remove_timer(ifi->ifi_ra_timer);
ifi->ifi_ra_timer = NULL;
} else if (!(oldifflags & IFF_UP) && /* DOWN to UP */
(ifi->ifi_flags & IFF_UP)) {
syslog(LOG_NOTICE,
"interface %s becomes up. restart timer.",
ifi->ifi_ifname);
ifi->ifi_state = IFI_STATE_TRANSITIVE;
ifi->ifi_burstcount =
MAX_INITIAL_RTR_ADVERTISEMENTS;
ifi->ifi_burstinterval =
MAX_INITIAL_RTR_ADVERT_INTERVAL;
ifi->ifi_ra_timer = rtadvd_add_timer(ra_timeout,
ra_timer_update, ifi, ifi);
ra_timer_update(ifi, &ifi->ifi_ra_timer->rat_tm);
rtadvd_set_timer(&ifi->ifi_ra_timer->rat_tm,
ifi->ifi_ra_timer);
} else if (prefixchange &&
(ifi->ifi_flags & IFF_UP)) {
/*
* An advertised prefix has been added or invalidated.
* Will notice the change in a short delay.
*/
set_short_delay(ifi);
}
}
return;
}
void
rtadvd_input(struct sockinfo *s)
{
ssize_t i;
int *hlimp = NULL;
#ifdef OLDRAWSOCKET
struct ip6_hdr *ip;
#endif
struct icmp6_hdr *icp;
int ifindex = 0;
struct cmsghdr *cm;
struct in6_pktinfo *pi = NULL;
char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
struct in6_addr dst = in6addr_any;
struct ifinfo *ifi;
syslog(LOG_DEBUG, "<%s> enter", __func__);
if (s == NULL) {
syslog(LOG_ERR, "<%s> internal error", __func__);
exit(1);
}
/*
* Get message. We reset msg_controllen since the field could
* be modified if we had received a message before setting
* receive options.
*/
rcvmhdr.msg_controllen = rcvcmsgbuflen;
if ((i = recvmsg(s->si_fd, &rcvmhdr, 0)) < 0)
return;
/* extract optional information via Advanced API */
for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&rcvmhdr);
cm;
cm = (struct cmsghdr *)CMSG_NXTHDR(&rcvmhdr, cm)) {
if (cm->cmsg_level == IPPROTO_IPV6 &&
cm->cmsg_type == IPV6_PKTINFO &&
cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) {
pi = (struct in6_pktinfo *)(CMSG_DATA(cm));
ifindex = pi->ipi6_ifindex;
dst = pi->ipi6_addr;
}
if (cm->cmsg_level == IPPROTO_IPV6 &&
cm->cmsg_type == IPV6_HOPLIMIT &&
cm->cmsg_len == CMSG_LEN(sizeof(int)))
hlimp = (int *)CMSG_DATA(cm);
}
if (ifindex == 0) {
syslog(LOG_ERR, "failed to get receiving interface");
return;
}
if (hlimp == NULL) {
syslog(LOG_ERR, "failed to get receiving hop limit");
return;
}
/*
* If we happen to receive data on an interface which is now gone
* or down, just discard the data.
*/
ifi = if_indextoifinfo(pi->ipi6_ifindex);
if (ifi == NULL || !(ifi->ifi_flags & IFF_UP)) {
syslog(LOG_INFO,
"<%s> received data on a disabled interface (%s)",
__func__,
(ifi == NULL) ? "[gone]" : ifi->ifi_ifname);
return;
}
#ifdef OLDRAWSOCKET
if ((size_t)i < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr)) {
syslog(LOG_ERR,
"packet size(%d) is too short", i);
return;
}
ip = (struct ip6_hdr *)rcvmhdr.msg_iov[0].iov_base;
icp = (struct icmp6_hdr *)(ip + 1); /* XXX: ext. hdr? */
#else
if ((size_t)i < sizeof(struct icmp6_hdr)) {
syslog(LOG_ERR, "packet size(%zd) is too short", i);
return;
}
icp = (struct icmp6_hdr *)rcvmhdr.msg_iov[0].iov_base;
#endif
switch (icp->icmp6_type) {
case ND_ROUTER_SOLICIT:
/*
* Message verification - RFC 4861 6.1.1
* XXX: these checks must be done in the kernel as well,
* but we can't completely rely on them.
*/
if (*hlimp != 255) {
syslog(LOG_NOTICE,
"RS with invalid hop limit(%d) "
"received from %s on %s",
*hlimp,
inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
sizeof(ntopbuf)),
if_indextoname(pi->ipi6_ifindex, ifnamebuf));
return;
}
if (icp->icmp6_code) {
syslog(LOG_NOTICE,
"RS with invalid ICMP6 code(%d) "
"received from %s on %s",
icp->icmp6_code,
inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
sizeof(ntopbuf)),
if_indextoname(pi->ipi6_ifindex, ifnamebuf));
return;
}
if ((size_t)i < sizeof(struct nd_router_solicit)) {
syslog(LOG_NOTICE,
"RS from %s on %s does not have enough "
"length (len = %zd)",
inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
sizeof(ntopbuf)),
if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
return;
}
rs_input(i, (struct nd_router_solicit *)icp, pi, &rcvfrom);
break;
case ND_ROUTER_ADVERT:
/*
* Message verification - RFC 4861 6.1.2
* XXX: there's the same dilemma as above...
*/
if (!IN6_IS_ADDR_LINKLOCAL(&rcvfrom.sin6_addr)) {
syslog(LOG_NOTICE,
"RA with non-linklocal source address "
"received from %s on %s",
inet_ntop(AF_INET6, &rcvfrom.sin6_addr,
ntopbuf, sizeof(ntopbuf)),
if_indextoname(pi->ipi6_ifindex, ifnamebuf));
return;
}
if (*hlimp != 255) {
syslog(LOG_NOTICE,
"RA with invalid hop limit(%d) "
"received from %s on %s",
*hlimp,
inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
sizeof(ntopbuf)),
if_indextoname(pi->ipi6_ifindex, ifnamebuf));
return;
}
if (icp->icmp6_code) {
syslog(LOG_NOTICE,
"RA with invalid ICMP6 code(%d) "
"received from %s on %s",
icp->icmp6_code,
inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
sizeof(ntopbuf)),
if_indextoname(pi->ipi6_ifindex, ifnamebuf));
return;
}
if ((size_t)i < sizeof(struct nd_router_advert)) {
syslog(LOG_NOTICE,
"RA from %s on %s does not have enough "
"length (len = %zd)",
inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
sizeof(ntopbuf)),
if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
return;
}
ra_input(i, (struct nd_router_advert *)icp, pi, &rcvfrom);
break;
case ICMP6_ROUTER_RENUMBERING:
if (mcastif == NULL) {
syslog(LOG_ERR, "received a router renumbering "
"message, but not allowed to be accepted");
break;
}
rr_input(i, (struct icmp6_router_renum *)icp, pi, &rcvfrom,
&dst);
break;
default:
/*
* Note that this case is POSSIBLE, especially just
* after invocation of the daemon. This is because we
* could receive message after opening the socket and
* before setting ICMP6 type filter(see sock_open()).
*/
syslog(LOG_ERR, "invalid icmp type(%d)", icp->icmp6_type);
return;
}
return;
}
static void
rs_input(int len, struct nd_router_solicit *rs,
struct in6_pktinfo *pi, struct sockaddr_in6 *from)
{
char ntopbuf[INET6_ADDRSTRLEN];
char ifnamebuf[IFNAMSIZ];
union nd_opt ndopts;
struct rainfo *rai;
struct ifinfo *ifi;
struct soliciter *sol;
syslog(LOG_DEBUG,
"<%s> RS received from %s on %s",
__func__,
inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)),
if_indextoname(pi->ipi6_ifindex, ifnamebuf));
/* ND option check */
memset(&ndopts, 0, sizeof(ndopts));
TAILQ_INIT(&ndopts.opt_list);
if (nd6_options((struct nd_opt_hdr *)(rs + 1),
len - sizeof(struct nd_router_solicit),
&ndopts, NDOPT_FLAG_SRCLINKADDR)) {
syslog(LOG_INFO,
"<%s> ND option check failed for an RS from %s on %s",
__func__,
inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
sizeof(ntopbuf)),
if_indextoname(pi->ipi6_ifindex, ifnamebuf));
return;
}
/*
* If the IP source address is the unspecified address, there
* must be no source link-layer address option in the message.
* (RFC 4861 6.1.1)
*/
if (IN6_IS_ADDR_UNSPECIFIED(&from->sin6_addr) &&
ndopts.opt_src_lladdr) {
syslog(LOG_INFO,
"<%s> RS from unspecified src on %s has a link-layer"
" address option",
__func__, if_indextoname(pi->ipi6_ifindex, ifnamebuf));
goto done;
}
ifi = if_indextoifinfo(pi->ipi6_ifindex);
if (ifi == NULL) {
syslog(LOG_INFO,
"<%s> if (idx=%d) not found. Why?",
__func__, pi->ipi6_ifindex);
goto done;
}
rai = ifi->ifi_rainfo;
if (rai == NULL) {
syslog(LOG_INFO,
"<%s> RS received on non advertising interface(%s)",
__func__,
if_indextoname(pi->ipi6_ifindex, ifnamebuf));
goto done;
}
rai->rai_ifinfo->ifi_rsinput++;
/*
* Decide whether to send RA according to the rate-limit
* consideration.
*/
/* record sockaddr waiting for RA, if possible */
sol = (struct soliciter *)malloc(sizeof(*sol));
if (sol) {
sol->sol_addr = *from;
/* XXX RFC 2553 need clarification on flowinfo */
sol->sol_addr.sin6_flowinfo = 0;
TAILQ_INSERT_TAIL(&rai->rai_soliciter, sol, sol_next);
}
/*
* If there is already a waiting RS packet, don't
* update the timer.
*/
if (ifi->ifi_rs_waitcount++)
goto done;
set_short_delay(ifi);
done:
free_ndopts(&ndopts);
return;
}
static void
set_short_delay(struct ifinfo *ifi)
{
long delay; /* must not be greater than 1000000 */
struct timeval interval, now, min_delay, tm_tmp, *rest;
if (ifi->ifi_ra_timer == NULL)
return;
/*
* Compute a random delay. If the computed value
* corresponds to a time later than the time the next
* multicast RA is scheduled to be sent, ignore the random
* delay and send the advertisement at the
* already-scheduled time. RFC 4861 6.2.6
*/
#ifdef HAVE_ARC4RANDOM
delay = arc4random_uniform(MAX_RA_DELAY_TIME);
#else
delay = random() % MAX_RA_DELAY_TIME;
#endif
interval.tv_sec = 0;
interval.tv_usec = delay;
rest = rtadvd_timer_rest(ifi->ifi_ra_timer);
if (TIMEVAL_LT(rest, &interval)) {
syslog(LOG_DEBUG, "<%s> random delay is larger than "
"the rest of the current timer", __func__);
interval = *rest;
}
/*
* If we sent a multicast Router Advertisement within
* the last MIN_DELAY_BETWEEN_RAS seconds, schedule
* the advertisement to be sent at a time corresponding to
* MIN_DELAY_BETWEEN_RAS plus the random value after the
* previous advertisement was sent.
*/
gettimeofday(&now, NULL);
TIMEVAL_SUB(&now, &ifi->ifi_ra_lastsent, &tm_tmp);
min_delay.tv_sec = MIN_DELAY_BETWEEN_RAS;
min_delay.tv_usec = 0;
if (TIMEVAL_LT(&tm_tmp, &min_delay)) {
TIMEVAL_SUB(&min_delay, &tm_tmp, &min_delay);
TIMEVAL_ADD(&min_delay, &interval, &interval);
}
rtadvd_set_timer(&interval, ifi->ifi_ra_timer);
}
static int
check_accept_rtadv(int idx)
{
struct ifinfo *ifi;
TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
if (ifi->ifi_ifindex == idx)
break;
}
if (ifi == NULL) {
syslog(LOG_DEBUG,
"<%s> if (idx=%d) not found. Why?",
__func__, idx);
return (0);
}
#if (__FreeBSD_version < 900000)
/*
* RA_RECV: !ip6.forwarding && ip6.accept_rtadv
* RA_SEND: ip6.forwarding
*/
return ((getinet6sysctl(IPV6CTL_FORWARDING) == 0) &&
(getinet6sysctl(IPV6CTL_ACCEPT_RTADV) == 1));
#else
/*
* RA_RECV: ND6_IFF_ACCEPT_RTADV
* RA_SEND: ip6.forwarding
*/
if (update_ifinfo_nd_flags(ifi) != 0) {
syslog(LOG_ERR, "cannot get nd6 flags (idx=%d)", idx);
return (0);
}
return (ifi->ifi_nd_flags & ND6_IFF_ACCEPT_RTADV);
#endif
}
static void
ra_input(int len, struct nd_router_advert *nra,
struct in6_pktinfo *pi, struct sockaddr_in6 *from)
{
struct rainfo *rai;
struct ifinfo *ifi;
char ntopbuf[INET6_ADDRSTRLEN];
char ifnamebuf[IFNAMSIZ];
union nd_opt ndopts;
const char *on_off[] = {"OFF", "ON"};
uint32_t reachabletime, retranstimer, mtu;
int inconsistent = 0;
int error;
syslog(LOG_DEBUG, "<%s> RA received from %s on %s", __func__,
inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)),
if_indextoname(pi->ipi6_ifindex, ifnamebuf));
/* ND option check */
memset(&ndopts, 0, sizeof(ndopts));
TAILQ_INIT(&ndopts.opt_list);
error = nd6_options((struct nd_opt_hdr *)(nra + 1),
len - sizeof(struct nd_router_advert), &ndopts,
NDOPT_FLAG_SRCLINKADDR | NDOPT_FLAG_PREFIXINFO | NDOPT_FLAG_MTU |
NDOPT_FLAG_RDNSS | NDOPT_FLAG_DNSSL);
if (error) {
syslog(LOG_INFO,
"<%s> ND option check failed for an RA from %s on %s",
__func__,
inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex,
ifnamebuf));
return;
}
/*
* RA consistency check according to RFC 4861 6.2.7
*/
ifi = if_indextoifinfo(pi->ipi6_ifindex);
if (ifi->ifi_rainfo == NULL) {
syslog(LOG_INFO,
"<%s> received RA from %s on non-advertising"
" interface(%s)",
__func__,
inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex,
ifnamebuf));
goto done;
}
rai = ifi->ifi_rainfo;
ifi->ifi_rainput++;
syslog(LOG_DEBUG, "<%s> ifi->ifi_rainput = %" PRIu64, __func__,
ifi->ifi_rainput);
/* Cur Hop Limit value */
if (nra->nd_ra_curhoplimit && rai->rai_hoplimit &&
nra->nd_ra_curhoplimit != rai->rai_hoplimit) {
syslog(LOG_NOTICE,
"CurHopLimit inconsistent on %s:"
" %d from %s, %d from us",
ifi->ifi_ifname, nra->nd_ra_curhoplimit,
inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
sizeof(ntopbuf)), rai->rai_hoplimit);
inconsistent++;
}
/* M flag */
if ((nra->nd_ra_flags_reserved & ND_RA_FLAG_MANAGED) !=
rai->rai_managedflg) {
syslog(LOG_NOTICE,
"M flag inconsistent on %s:"
" %s from %s, %s from us",
ifi->ifi_ifname, on_off[!rai->rai_managedflg],
inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
sizeof(ntopbuf)), on_off[rai->rai_managedflg]);
inconsistent++;
}
/* O flag */
if ((nra->nd_ra_flags_reserved & ND_RA_FLAG_OTHER) !=
rai->rai_otherflg) {
syslog(LOG_NOTICE,
"O flag inconsistent on %s:"
" %s from %s, %s from us",
ifi->ifi_ifname, on_off[!rai->rai_otherflg],
inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
sizeof(ntopbuf)), on_off[rai->rai_otherflg]);
inconsistent++;
}
/* Reachable Time */
reachabletime = ntohl(nra->nd_ra_reachable);
if (reachabletime && rai->rai_reachabletime &&
reachabletime != rai->rai_reachabletime) {
syslog(LOG_NOTICE,
"ReachableTime inconsistent on %s:"
" %d from %s, %d from us",
ifi->ifi_ifname, reachabletime,
inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
sizeof(ntopbuf)), rai->rai_reachabletime);
inconsistent++;
}
/* Retrans Timer */
retranstimer = ntohl(nra->nd_ra_retransmit);
if (retranstimer && rai->rai_retranstimer &&
retranstimer != rai->rai_retranstimer) {
syslog(LOG_NOTICE,
"RetranceTimer inconsistent on %s:"
" %d from %s, %d from us",
ifi->ifi_ifname, retranstimer,
inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
sizeof(ntopbuf)), rai->rai_retranstimer);
inconsistent++;
}
/* Values in the MTU options */
if (ndopts.opt_mtu) {
mtu = ntohl(ndopts.opt_mtu->nd_opt_mtu_mtu);
if (mtu && rai->rai_linkmtu && mtu != rai->rai_linkmtu) {
syslog(LOG_NOTICE,
"MTU option value inconsistent on %s:"
" %d from %s, %d from us",
ifi->ifi_ifname, mtu,
inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
sizeof(ntopbuf)), rai->rai_linkmtu);
inconsistent++;
}
}
/* Preferred and Valid Lifetimes for prefixes */
{
struct nd_optlist *nol;
if (ndopts.opt_pi)
if (prefix_check(ndopts.opt_pi, rai, from))
inconsistent++;
TAILQ_FOREACH(nol, &ndopts.opt_list, nol_next)
if (prefix_check((struct nd_opt_prefix_info *)nol->nol_opt,
rai, from))
inconsistent++;
}
if (inconsistent)
ifi->ifi_rainconsistent++;
done:
free_ndopts(&ndopts);
return;
}
/* return a non-zero value if the received prefix is inconsitent with ours */
static int
prefix_check(struct nd_opt_prefix_info *pinfo,
struct rainfo *rai, struct sockaddr_in6 *from)
{
struct ifinfo *ifi;
uint32_t preferred_time, valid_time;
struct prefix *pfx;
int inconsistent = 0;
char ntopbuf[INET6_ADDRSTRLEN];
char prefixbuf[INET6_ADDRSTRLEN];
struct timeval now;
#if 0 /* impossible */
if (pinfo->nd_opt_pi_type != ND_OPT_PREFIX_INFORMATION)
return (0);
#endif
ifi = rai->rai_ifinfo;
/*
* log if the adveritsed prefix has link-local scope(sanity check?)
*/
if (IN6_IS_ADDR_LINKLOCAL(&pinfo->nd_opt_pi_prefix))
syslog(LOG_INFO,
"<%s> link-local prefix %s/%d is advertised "
"from %s on %s",
__func__,
inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
sizeof(prefixbuf)),
pinfo->nd_opt_pi_prefix_len,
inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
sizeof(ntopbuf)), ifi->ifi_ifname);
if ((pfx = find_prefix(rai, &pinfo->nd_opt_pi_prefix,
pinfo->nd_opt_pi_prefix_len)) == NULL) {
syslog(LOG_INFO,
"<%s> prefix %s/%d from %s on %s is not in our list",
__func__,
inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
sizeof(prefixbuf)),
pinfo->nd_opt_pi_prefix_len,
inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
sizeof(ntopbuf)), ifi->ifi_ifname);
return (0);
}
preferred_time = ntohl(pinfo->nd_opt_pi_preferred_time);
if (pfx->pfx_pltimeexpire) {
/*
* The lifetime is decremented in real time, so we should
* compare the expiration time.
* (RFC 2461 Section 6.2.7.)
* XXX: can we really expect that all routers on the link
* have synchronized clocks?
*/
gettimeofday(&now, NULL);
preferred_time += now.tv_sec;
if (!pfx->pfx_timer && rai->rai_clockskew &&
abs(preferred_time - pfx->pfx_pltimeexpire) > rai->rai_clockskew) {
syslog(LOG_INFO,
"<%s> preferred lifetime for %s/%d"
" (decr. in real time) inconsistent on %s:"
" %" PRIu32 " from %s, %" PRIu32 " from us",
__func__,
inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
sizeof(prefixbuf)),
pinfo->nd_opt_pi_prefix_len,
ifi->ifi_ifname, preferred_time,
inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
sizeof(ntopbuf)), pfx->pfx_pltimeexpire);
inconsistent++;
}
} else if (!pfx->pfx_timer && preferred_time != pfx->pfx_preflifetime)
syslog(LOG_INFO,
"<%s> preferred lifetime for %s/%d"
" inconsistent on %s:"
" %d from %s, %d from us",
__func__,
inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
sizeof(prefixbuf)),
pinfo->nd_opt_pi_prefix_len,
ifi->ifi_ifname, preferred_time,
inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
sizeof(ntopbuf)), pfx->pfx_preflifetime);
valid_time = ntohl(pinfo->nd_opt_pi_valid_time);
if (pfx->pfx_vltimeexpire) {
gettimeofday(&now, NULL);
valid_time += now.tv_sec;
if (!pfx->pfx_timer && rai->rai_clockskew &&
abs(valid_time - pfx->pfx_vltimeexpire) > rai->rai_clockskew) {
syslog(LOG_INFO,
"<%s> valid lifetime for %s/%d"
" (decr. in real time) inconsistent on %s:"
" %d from %s, %" PRIu32 " from us",
__func__,
inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
sizeof(prefixbuf)),
pinfo->nd_opt_pi_prefix_len,
ifi->ifi_ifname, preferred_time,
inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
sizeof(ntopbuf)), pfx->pfx_vltimeexpire);
inconsistent++;
}
} else if (!pfx->pfx_timer && valid_time != pfx->pfx_validlifetime) {
syslog(LOG_INFO,
"<%s> valid lifetime for %s/%d"
" inconsistent on %s:"
" %d from %s, %d from us",
__func__,
inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
sizeof(prefixbuf)),
pinfo->nd_opt_pi_prefix_len,
ifi->ifi_ifname, valid_time,
inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
sizeof(ntopbuf)), pfx->pfx_validlifetime);
inconsistent++;
}
return (inconsistent);
}
struct prefix *
find_prefix(struct rainfo *rai, struct in6_addr *prefix, int plen)
{
struct prefix *pfx;
int bytelen, bitlen;
char bitmask;
TAILQ_FOREACH(pfx, &rai->rai_prefix, pfx_next) {
if (plen != pfx->pfx_prefixlen)
continue;
bytelen = plen / 8;
bitlen = plen % 8;
bitmask = 0xff << (8 - bitlen);
if (memcmp((void *)prefix, (void *)&pfx->pfx_prefix, bytelen))
continue;
if (bitlen == 0 ||
((prefix->s6_addr[bytelen] & bitmask) ==
(pfx->pfx_prefix.s6_addr[bytelen] & bitmask))) {
return (pfx);
}
}
return (NULL);
}
/* check if p0/plen0 matches p1/plen1; return 1 if matches, otherwise 0. */
int
prefix_match(struct in6_addr *p0, int plen0,
struct in6_addr *p1, int plen1)
{
int bytelen, bitlen;
char bitmask;
if (plen0 < plen1)
return (0);
bytelen = plen1 / 8;
bitlen = plen1 % 8;
bitmask = 0xff << (8 - bitlen);
if (memcmp((void *)p0, (void *)p1, bytelen))
return (0);
if (bitlen == 0 ||
((p0->s6_addr[bytelen] & bitmask) ==
(p1->s6_addr[bytelen] & bitmask))) {
return (1);
}
return (0);
}
static int
nd6_options(struct nd_opt_hdr *hdr, int limit,
union nd_opt *ndopts, uint32_t optflags)
{
int optlen = 0;
for (; limit > 0; limit -= optlen) {
if ((size_t)limit < sizeof(struct nd_opt_hdr)) {
syslog(LOG_INFO, "<%s> short option header", __func__);
goto bad;
}
hdr = (struct nd_opt_hdr *)((caddr_t)hdr + optlen);
if (hdr->nd_opt_len == 0) {
syslog(LOG_INFO,
"<%s> bad ND option length(0) (type = %d)",
__func__, hdr->nd_opt_type);
goto bad;
}
optlen = hdr->nd_opt_len << 3;
if (optlen > limit) {
syslog(LOG_INFO, "<%s> short option", __func__);
goto bad;
}
if (hdr->nd_opt_type > ND_OPT_MTU &&
hdr->nd_opt_type != ND_OPT_RDNSS &&
hdr->nd_opt_type != ND_OPT_DNSSL) {
syslog(LOG_INFO, "<%s> unknown ND option(type %d)",
__func__, hdr->nd_opt_type);
continue;
}
if ((ndopt_flags[hdr->nd_opt_type] & optflags) == 0) {
syslog(LOG_INFO, "<%s> unexpected ND option(type %d)",
__func__, hdr->nd_opt_type);
continue;
}
/*
* Option length check. Do it here for all fixed-length
* options.
*/
switch (hdr->nd_opt_type) {
case ND_OPT_MTU:
if (optlen == sizeof(struct nd_opt_mtu))
break;
goto skip;
case ND_OPT_RDNSS:
if (optlen >= 24 &&
(optlen - sizeof(struct nd_opt_rdnss)) % 16 == 0)
break;
goto skip;
case ND_OPT_DNSSL:
if (optlen >= 16 &&
(optlen - sizeof(struct nd_opt_dnssl)) % 8 == 0)
break;
goto skip;
case ND_OPT_PREFIX_INFORMATION:
if (optlen == sizeof(struct nd_opt_prefix_info))
break;
skip:
syslog(LOG_INFO, "<%s> invalid option length",
__func__);
continue;
}
switch (hdr->nd_opt_type) {
case ND_OPT_TARGET_LINKADDR:
case ND_OPT_REDIRECTED_HEADER:
case ND_OPT_RDNSS:
case ND_OPT_DNSSL:
break; /* we don't care about these options */
case ND_OPT_SOURCE_LINKADDR:
case ND_OPT_MTU:
if (ndopts->opt_array[hdr->nd_opt_type]) {
syslog(LOG_INFO,
"<%s> duplicated ND option (type = %d)",
__func__, hdr->nd_opt_type);
}
ndopts->opt_array[hdr->nd_opt_type] = hdr;
break;
case ND_OPT_PREFIX_INFORMATION:
{
struct nd_optlist *nol;
if (ndopts->opt_pi == 0) {
ndopts->opt_pi =
(struct nd_opt_prefix_info *)hdr;
continue;
}
nol = malloc(sizeof(*nol));
if (nol == NULL) {
syslog(LOG_ERR, "<%s> can't allocate memory",
__func__);
goto bad;
}
nol->nol_opt = hdr;
TAILQ_INSERT_TAIL(&(ndopts->opt_list), nol, nol_next);
break;
}
default: /* impossible */
break;
}
}
return (0);
bad:
free_ndopts(ndopts);
return (-1);
}
static void
free_ndopts(union nd_opt *ndopts)
{
struct nd_optlist *nol;
while ((nol = TAILQ_FIRST(&ndopts->opt_list)) != NULL) {
TAILQ_REMOVE(&ndopts->opt_list, nol, nol_next);
free(nol);
}
}
void
sock_open(struct sockinfo *s)
{
struct icmp6_filter filt;
int on;
/* XXX: should be max MTU attached to the node */
static char answer[1500];
syslog(LOG_DEBUG, "<%s> enter", __func__);
if (s == NULL) {
syslog(LOG_ERR, "<%s> internal error", __func__);
exit(1);
}
rcvcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
CMSG_SPACE(sizeof(int));
rcvcmsgbuf = (char *)malloc(rcvcmsgbuflen);
if (rcvcmsgbuf == NULL) {
syslog(LOG_ERR, "<%s> not enough core", __func__);
exit(1);
}
sndcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
CMSG_SPACE(sizeof(int));
sndcmsgbuf = (char *)malloc(sndcmsgbuflen);
if (sndcmsgbuf == NULL) {
syslog(LOG_ERR, "<%s> not enough core", __func__);
exit(1);
}
if ((s->si_fd = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) {
syslog(LOG_ERR, "<%s> socket: %s", __func__, strerror(errno));
exit(1);
}
/* specify to tell receiving interface */
on = 1;
if (setsockopt(s->si_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
sizeof(on)) < 0) {
syslog(LOG_ERR, "<%s> IPV6_RECVPKTINFO: %s", __func__,
strerror(errno));
exit(1);
}
on = 1;
/* specify to tell value of hoplimit field of received IP6 hdr */
if (setsockopt(s->si_fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
sizeof(on)) < 0) {
syslog(LOG_ERR, "<%s> IPV6_RECVHOPLIMIT: %s", __func__,
strerror(errno));
exit(1);
}
ICMP6_FILTER_SETBLOCKALL(&filt);
ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filt);
ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
if (mcastif != NULL)
ICMP6_FILTER_SETPASS(ICMP6_ROUTER_RENUMBERING, &filt);
if (setsockopt(s->si_fd, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
sizeof(filt)) < 0) {
syslog(LOG_ERR, "<%s> IICMP6_FILTER: %s",
__func__, strerror(errno));
exit(1);
}
/* initialize msghdr for receiving packets */
rcviov[0].iov_base = (caddr_t)answer;
rcviov[0].iov_len = sizeof(answer);
rcvmhdr.msg_name = (caddr_t)&rcvfrom;
rcvmhdr.msg_namelen = sizeof(rcvfrom);
rcvmhdr.msg_iov = rcviov;
rcvmhdr.msg_iovlen = 1;
rcvmhdr.msg_control = (caddr_t) rcvcmsgbuf;
rcvmhdr.msg_controllen = rcvcmsgbuflen;
/* initialize msghdr for sending packets */
sndmhdr.msg_namelen = sizeof(struct sockaddr_in6);
sndmhdr.msg_iov = sndiov;
sndmhdr.msg_iovlen = 1;
sndmhdr.msg_control = (caddr_t)sndcmsgbuf;
sndmhdr.msg_controllen = sndcmsgbuflen;
return;
}
/* open a routing socket to watch the routing table */
static void
rtsock_open(struct sockinfo *s)
{
if (s == NULL) {
syslog(LOG_ERR, "<%s> internal error", __func__);
exit(1);
}
if ((s->si_fd = socket(PF_ROUTE, SOCK_RAW, 0)) < 0) {
syslog(LOG_ERR,
"<%s> socket: %s", __func__, strerror(errno));
exit(1);
}
}
struct ifinfo *
if_indextoifinfo(int idx)
{
struct ifinfo *ifi;
TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
if (ifi->ifi_ifindex == idx)
return (ifi);
}
if (ifi != NULL)
syslog(LOG_DEBUG, "<%s> ifi found (idx=%d)",
__func__, idx);
else
syslog(LOG_DEBUG, "<%s> ifi not found (idx=%d)",
__func__, idx);
return (NULL); /* search failed */
}
void
ra_output(struct ifinfo *ifi)
{
int i;
struct cmsghdr *cm;
struct in6_pktinfo *pi;
struct soliciter *sol;
struct rainfo *rai;
switch (ifi->ifi_state) {
case IFI_STATE_CONFIGURED:
rai = ifi->ifi_rainfo;
break;
case IFI_STATE_TRANSITIVE:
rai = ifi->ifi_rainfo_trans;
break;
case IFI_STATE_UNCONFIGURED:
syslog(LOG_DEBUG, "<%s> %s is unconfigured. "
"Skip sending RAs.",
__func__, ifi->ifi_ifname);
return;
default:
rai = NULL;
}
if (rai == NULL) {
syslog(LOG_DEBUG, "<%s> rainfo is NULL on %s."
"Skip sending RAs.",
__func__, ifi->ifi_ifname);
return;
}
if (!(ifi->ifi_flags & IFF_UP)) {
syslog(LOG_DEBUG, "<%s> %s is not up. "
"Skip sending RAs.",
__func__, ifi->ifi_ifname);
return;
}
/*
* Check lifetime, ACCEPT_RTADV flag, and ip6.forwarding.
*
* (lifetime == 0) = output
* (lifetime != 0 && (check_accept_rtadv()) = no output
*
* Basically, hosts MUST NOT send Router Advertisement
* messages at any time (RFC 4861, Section 6.2.3). However, it
* would sometimes be useful to allow hosts to advertise some
* parameters such as prefix information and link MTU. Thus,
* we allow hosts to invoke rtadvd only when router lifetime
* (on every advertising interface) is explicitly set
* zero. (see also the above section)
*/
syslog(LOG_DEBUG,
"<%s> check lifetime=%d, ACCEPT_RTADV=%d, ip6.forwarding=%d "
"on %s", __func__,
rai->rai_lifetime,
check_accept_rtadv(ifi->ifi_ifindex),
getinet6sysctl(IPV6CTL_FORWARDING),
ifi->ifi_ifname);
if (rai->rai_lifetime != 0) {
if (getinet6sysctl(IPV6CTL_FORWARDING) == 0) {
syslog(LOG_ERR,
"non-zero lifetime RA "
"but net.inet6.ip6.forwarding=0. "
"Ignored.");
return;
}
if (check_accept_rtadv(ifi->ifi_ifindex)) {
syslog(LOG_ERR,
"non-zero lifetime RA "
"on RA receiving interface %s."
" Ignored.", ifi->ifi_ifname);
return;
}
}
make_packet(rai); /* XXX: inefficient */
sndmhdr.msg_name = (caddr_t)&sin6_linklocal_allnodes;
sndmhdr.msg_iov[0].iov_base = (caddr_t)rai->rai_ra_data;
sndmhdr.msg_iov[0].iov_len = rai->rai_ra_datalen;
cm = CMSG_FIRSTHDR(&sndmhdr);
/* specify the outgoing interface */
cm->cmsg_level = IPPROTO_IPV6;
cm->cmsg_type = IPV6_PKTINFO;
cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
pi = (struct in6_pktinfo *)CMSG_DATA(cm);
memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr)); /*XXX*/
pi->ipi6_ifindex = ifi->ifi_ifindex;
/* specify the hop limit of the packet */
{
int hoplimit = 255;
cm = CMSG_NXTHDR(&sndmhdr, cm);
cm->cmsg_level = IPPROTO_IPV6;
cm->cmsg_type = IPV6_HOPLIMIT;
cm->cmsg_len = CMSG_LEN(sizeof(int));
memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
}
syslog(LOG_DEBUG,
"<%s> send RA on %s, # of RS waitings = %d",
__func__, ifi->ifi_ifname, ifi->ifi_rs_waitcount);
i = sendmsg(sock.si_fd, &sndmhdr, 0);
if (i < 0 || (size_t)i != rai->rai_ra_datalen) {
if (i < 0) {
syslog(LOG_ERR, "<%s> sendmsg on %s: %s",
__func__, ifi->ifi_ifname,
strerror(errno));
}
}
/*
* unicast advertisements
* XXX commented out. reason: though spec does not forbit it, unicast
* advert does not really help
*/
while ((sol = TAILQ_FIRST(&rai->rai_soliciter)) != NULL) {
TAILQ_REMOVE(&rai->rai_soliciter, sol, sol_next);
free(sol);
}
/* update timestamp */
gettimeofday(&ifi->ifi_ra_lastsent, NULL);
/* update counter */
ifi->ifi_rs_waitcount = 0;
ifi->ifi_raoutput++;
switch (ifi->ifi_state) {
case IFI_STATE_CONFIGURED:
if (ifi->ifi_burstcount > 0)
ifi->ifi_burstcount--;
break;
case IFI_STATE_TRANSITIVE:
ifi->ifi_burstcount--;
if (ifi->ifi_burstcount == 0) {
if (ifi->ifi_rainfo == ifi->ifi_rainfo_trans) {
/* Initial burst finished. */
if (ifi->ifi_rainfo_trans != NULL)
ifi->ifi_rainfo_trans = NULL;
}
/* Remove burst RA information */
if (ifi->ifi_rainfo_trans != NULL) {
rm_rainfo(ifi->ifi_rainfo_trans);
ifi->ifi_rainfo_trans = NULL;
}
if (ifi->ifi_rainfo != NULL) {
/*
* TRANSITIVE -> CONFIGURED
*
* After initial burst or transition from
* one configuration to another,
* ifi_rainfo always points to the next RA
* information.
*/
ifi->ifi_state = IFI_STATE_CONFIGURED;
syslog(LOG_DEBUG,
"<%s> ifname=%s marked as "
"CONFIGURED.", __func__,
ifi->ifi_ifname);
} else {
/*
* TRANSITIVE -> UNCONFIGURED
*
* If ifi_rainfo points to NULL, this
* interface is shutting down.
*
*/
int error;
ifi->ifi_state = IFI_STATE_UNCONFIGURED;
syslog(LOG_DEBUG,
"<%s> ifname=%s marked as "
"UNCONFIGURED.", __func__,
ifi->ifi_ifname);
error = sock_mc_leave(&sock,
ifi->ifi_ifindex);
if (error)
exit(1);
}
}
break;
}
}
/* process RA timer */
struct rtadvd_timer *
ra_timeout(void *arg)
{
struct ifinfo *ifi;
ifi = (struct ifinfo *)arg;
syslog(LOG_DEBUG, "<%s> RA timer on %s is expired",
__func__, ifi->ifi_ifname);
ra_output(ifi);
return (ifi->ifi_ra_timer);
}
/* update RA timer */
void
ra_timer_update(void *arg, struct timeval *tm)
{
uint16_t interval;
struct rainfo *rai;
struct ifinfo *ifi;
ifi = (struct ifinfo *)arg;
rai = ifi->ifi_rainfo;
interval = 0;
switch (ifi->ifi_state) {
case IFI_STATE_UNCONFIGURED:
return;
break;
case IFI_STATE_CONFIGURED:
/*
* Whenever a multicast advertisement is sent from
* an interface, the timer is reset to a
* uniformly-distributed random value between the
* interface's configured MinRtrAdvInterval and
* MaxRtrAdvInterval (RFC4861 6.2.4).
*/
interval = rai->rai_mininterval;
#ifdef HAVE_ARC4RANDOM
interval += arc4random_uniform(rai->rai_maxinterval -
rai->rai_mininterval);
#else
interval += random() % (rai->rai_maxinterval -
rai->rai_mininterval);
#endif
break;
case IFI_STATE_TRANSITIVE:
/*
* For the first few advertisements (up to
* MAX_INITIAL_RTR_ADVERTISEMENTS), if the randomly chosen
* interval is greater than
* MAX_INITIAL_RTR_ADVERT_INTERVAL, the timer SHOULD be
* set to MAX_INITIAL_RTR_ADVERT_INTERVAL instead. (RFC
* 4861 6.2.4)
*
* In such cases, the router SHOULD transmit one or more
* (but not more than MAX_FINAL_RTR_ADVERTISEMENTS) final
* multicast Router Advertisements on the interface with a
* Router Lifetime field of zero. (RFC 4861 6.2.5)
*/
interval = ifi->ifi_burstinterval;
break;
}
tm->tv_sec = interval;
tm->tv_usec = 0;
syslog(LOG_DEBUG,
"<%s> RA timer on %s is set to %ld:%ld",
__func__, ifi->ifi_ifname,
(long int)tm->tv_sec, (long int)tm->tv_usec);
return;
}
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