/
rtadvd.c
1638 lines (1487 loc) · 41.8 KB
/
rtadvd.c
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/* $NetBSD: rtadvd.c,v 1.34 2007/01/16 17:32:04 hubertf Exp $ */
/* $KAME: rtadvd.c,v 1.92 2005/10/17 14:40:02 suz 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/param.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <sys/time.h>
#include <sys/queue.h>
#include <net/if.h>
#include <net/route.h>
#include <net/if_dl.h>
#include <netinet/in.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet/icmp6.h>
#include <arpa/inet.h>
#include <time.h>
#include <unistd.h>
#include <stdio.h>
#include <err.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <syslog.h>
#include <util.h>
#include <poll.h>
#include "rtadvd.h"
#include "rrenum.h"
#include "advcap.h"
#include "timer.h"
#include "if.h"
#include "config.h"
#include "dump.h"
struct msghdr rcvmhdr;
static u_char *rcvcmsgbuf;
static size_t rcvcmsgbuflen;
static u_char *sndcmsgbuf = NULL;
static size_t sndcmsgbuflen;
volatile sig_atomic_t do_dump;
volatile sig_atomic_t do_die;
struct msghdr sndmhdr;
struct iovec rcviov[2];
struct iovec sndiov[2];
struct sockaddr_in6 rcvfrom;
struct sockaddr_in6 sin6_allnodes = {sizeof(sin6_allnodes), AF_INET6};
struct in6_addr in6a_site_allrouters;
static char *dumpfilename = "/var/run/rtadvd.dump"; /* XXX: should be configurable */
static char *mcastif;
int sock;
int rtsock = -1;
int accept_rr = 0;
int dflag = 0, sflag = 0;
char *conffile = NULL;
struct rainfo *ralist = NULL;
struct nd_optlist {
struct nd_optlist *next;
struct nd_opt_hdr *opt;
};
union nd_opts {
struct nd_opt_hdr *nd_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;
struct nd_optlist *list;
} nd_opt_each;
};
#define nd_opts_src_lladdr nd_opt_each.src_lladdr
#define nd_opts_tgt_lladdr nd_opt_each.tgt_lladdr
#define nd_opts_pi nd_opt_each.pi
#define nd_opts_rh nd_opt_each.rh
#define nd_opts_mtu nd_opt_each.mtu
#define nd_opts_list nd_opt_each.list
#define NDOPT_FLAG_SRCLINKADDR 0x1
#define NDOPT_FLAG_TGTLINKADDR 0x2
#define NDOPT_FLAG_PREFIXINFO 0x4
#define NDOPT_FLAG_RDHDR 0x8
#define NDOPT_FLAG_MTU 0x10
u_int32_t ndopt_flags[] = {
0, NDOPT_FLAG_SRCLINKADDR, NDOPT_FLAG_TGTLINKADDR,
NDOPT_FLAG_PREFIXINFO, NDOPT_FLAG_RDHDR, NDOPT_FLAG_MTU,
};
int main __P((int, char *[]));
static void set_die __P((int));
static void die __P((void));
static void sock_open __P((void));
static void rtsock_open __P((void));
static void rtadvd_input __P((void));
static void rs_input __P((int, struct nd_router_solicit *,
struct in6_pktinfo *, struct sockaddr_in6 *));
static void ra_input __P((int, struct nd_router_advert *,
struct in6_pktinfo *, struct sockaddr_in6 *));
static int prefix_check __P((struct nd_opt_prefix_info *, struct rainfo *,
struct sockaddr_in6 *));
static int nd6_options __P((struct nd_opt_hdr *, int,
union nd_opts *, u_int32_t));
static void free_ndopts __P((union nd_opts *));
static void ra_output __P((struct rainfo *));
static void rtmsg_input __P((void));
static void rtadvd_set_dump_file __P((int));
static void set_short_delay __P((struct rainfo *));
int
main(argc, argv)
int argc;
char *argv[];
{
struct pollfd set[2];
struct timeval *timeout;
int i, ch;
int fflag = 0, logopt;
/* get command line options and arguments */
#define OPTIONS "c:dDfM:Rs"
while ((ch = getopt(argc, argv, OPTIONS)) != -1) {
#undef OPTIONS
switch (ch) {
case 'c':
conffile = optarg;
break;
case 'd':
dflag = 1;
break;
case 'D':
dflag = 2;
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;
}
}
argc -= optind;
argv += optind;
if (argc == 0) {
fprintf(stderr,
"usage: rtadvd [-DdfMRs] [-c configfile] "
"interface ...\n");
exit(1);
}
logopt = LOG_NDELAY | LOG_PID;
if (fflag)
logopt |= LOG_PERROR;
openlog("rtadvd", logopt, LOG_DAEMON);
/* set log level */
if (dflag == 0)
(void)setlogmask(LOG_UPTO(LOG_ERR));
if (dflag == 1)
(void)setlogmask(LOG_UPTO(LOG_INFO));
/* timer initialization */
rtadvd_timer_init();
/* get iflist block from kernel */
init_iflist();
while (argc--)
getconfig(*argv++);
if (inet_pton(AF_INET6, ALLNODES, &sin6_allnodes.sin6_addr) != 1) {
fprintf(stderr, "fatal: inet_pton failed\n");
exit(1);
}
if (!fflag)
daemon(1, 0);
sock_open();
/* record the current PID */
if (pidfile(NULL) < 0) {
syslog(LOG_ERR,
"<%s> failed to open the pid log file, run anyway.",
__func__);
}
set[0].fd = sock;
set[0].events = POLLIN;
if (sflag == 0) {
rtsock_open();
set[1].fd = rtsock;
set[1].events = POLLIN;
} else
set[1].fd = -1;
signal(SIGTERM, set_die);
signal(SIGUSR1, rtadvd_set_dump_file);
for (;;) {
if (do_dump) { /* SIGUSR1 */
do_dump = 0;
rtadvd_dump_file(dumpfilename);
}
if (do_die) {
die();
/*NOTREACHED*/
}
/* 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, 2, timeout ? (timeout->tv_sec * 1000 +
timeout->tv_usec / 1000) : INFTIM)) < 0) {
/* EINTR would occur upon SIGUSR1 for status dump */
if (errno != EINTR)
syslog(LOG_ERR, "<%s> poll: %s",
__func__, strerror(errno));
continue;
}
if (i == 0) /* timeout */
continue;
if (rtsock != -1 && set[1].revents & POLLIN)
rtmsg_input();
if (set[0].revents & POLLIN)
rtadvd_input();
}
exit(0); /* NOTREACHED */
}
static void
rtadvd_set_dump_file(sig)
int sig;
{
do_dump = 1;
}
static void
set_die(sig)
int sig;
{
do_die = 1;
}
static void
die()
{
struct rainfo *ra;
int i;
const int retrans = MAX_FINAL_RTR_ADVERTISEMENTS;
if (dflag > 1) {
syslog(LOG_DEBUG, "<%s> cease to be an advertising router\n",
__func__);
}
for (ra = ralist; ra; ra = ra->next) {
ra->lifetime = 0;
make_packet(ra);
}
for (i = 0; i < retrans; i++) {
for (ra = ralist; ra; ra = ra->next)
ra_output(ra);
sleep(MIN_DELAY_BETWEEN_RAS);
}
exit(0);
/*NOTREACHED*/
}
static void
rtmsg_input()
{
int n, type, ifindex = 0, plen;
size_t len;
union rt_msghdr_buf {
struct rt_msghdr rt_msghdr;
char data[2048];
} buffer;
char *msg, *next, *lim;
char ifname[IF_NAMESIZE];
struct prefix *prefix;
struct rainfo *rai;
struct in6_addr *addr;
char addrbuf[INET6_ADDRSTRLEN];
int prefixchange = 0;
n = read(rtsock, &buffer, sizeof(buffer));
msg = buffer.data;
if (dflag > 1) {
syslog(LOG_DEBUG, "<%s> received a routing message "
"(type = %d, len = %d)", __func__, rtmsg_type(msg), n);
}
if (n > rtmsg_len(msg)) {
/*
* This usually won't happen for messages received on
* a routing socket.
*/
if (dflag > 1)
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, rtmsg_len(msg));
#if 0
/* adjust length */
n = rtmsg_len(msg);
#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));
if (len == 0)
break;
type = rtmsg_type(next);
switch (type) {
case RTM_ADD:
case RTM_DELETE:
ifindex = get_rtm_ifindex(next);
break;
case RTM_NEWADDR:
case RTM_DELADDR:
ifindex = get_ifam_ifindex(next);
break;
case RTM_IFINFO:
ifindex = get_ifm_ifindex(next);
break;
default:
/* should not reach here */
if (dflag > 1) {
syslog(LOG_DEBUG,
"<%s:%d> unknown rtmsg %d on %s",
__func__, __LINE__, type,
if_indextoname(ifindex, ifname));
}
continue;
}
if ((rai = if_indextorainfo(ifindex)) == NULL) {
if (dflag > 1) {
syslog(LOG_DEBUG,
"<%s> route changed on "
"non advertising interface(%s)",
__func__,
if_indextoname(ifindex, ifname));
}
continue;
}
oldifflags = iflist[ifindex]->ifm_flags;
switch (type) {
case RTM_ADD:
/* init ifflags because it may have changed */
iflist[ifindex]->ifm_flags =
if_getflags(ifindex, iflist[ifindex]->ifm_flags);
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;
}
prefix = find_prefix(rai, addr, plen);
if (prefix) {
if (prefix->timer) {
/*
* If the prefix has been invalidated,
* make it available again.
*/
update_prefix(prefix);
prefixchange = 1;
} else if (dflag > 1) {
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, INET6_ADDRSTRLEN),
plen, rai->ifname);
}
break;
}
make_prefix(rai, ifindex, addr, plen);
prefixchange = 1;
break;
case RTM_DELETE:
/* init ifflags because it may have changed */
iflist[ifindex]->ifm_flags =
if_getflags(ifindex, iflist[ifindex]->ifm_flags);
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;
}
prefix = find_prefix(rai, addr, plen);
if (prefix == NULL) {
if (dflag > 1) {
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, INET6_ADDRSTRLEN),
plen, rai->ifname);
}
break;
}
invalidate_prefix(prefix);
prefixchange = 1;
break;
case RTM_NEWADDR:
case RTM_DELADDR:
/* init ifflags because it may have changed */
iflist[ifindex]->ifm_flags =
if_getflags(ifindex, iflist[ifindex]->ifm_flags);
break;
case RTM_IFINFO:
iflist[ifindex]->ifm_flags = get_ifm_flags(next);
break;
default:
/* should not reach here */
if (dflag > 1) {
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) != 0 && /* UP to DOWN */
(iflist[ifindex]->ifm_flags & IFF_UP) == 0) {
syslog(LOG_INFO,
"<%s> interface %s becomes down. stop timer.",
__func__, rai->ifname);
rtadvd_remove_timer(&rai->timer);
} else if ((oldifflags & IFF_UP) == 0 && /* DOWN to UP */
(iflist[ifindex]->ifm_flags & IFF_UP) != 0) {
syslog(LOG_INFO,
"<%s> interface %s becomes up. restart timer.",
__func__, rai->ifname);
rai->initcounter = 0; /* reset the counter */
rai->waiting = 0; /* XXX */
rai->timer = rtadvd_add_timer(ra_timeout,
ra_timer_update, rai, rai);
ra_timer_update((void *)rai, &rai->timer->tm);
rtadvd_set_timer(&rai->timer->tm, rai->timer);
} else if (prefixchange &&
iflist[ifindex]->ifm_flags & IFF_UP) {
/*
* An advertised prefix has been added or invalidated.
* Will notice the change in a short delay.
*/
rai->initcounter = 0;
set_short_delay(rai);
}
}
return;
}
void
rtadvd_input()
{
int 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;
/*
* 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(sock, &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,
"<%s> failed to get receiving interface",
__func__);
return;
}
if (hlimp == NULL) {
syslog(LOG_ERR,
"<%s> failed to get receiving hop limit",
__func__);
return;
}
/*
* If we happen to receive data on an interface which is now down,
* just discard the data.
*/
if ((iflist[pi->ipi6_ifindex]->ifm_flags & IFF_UP) == 0) {
syslog(LOG_INFO,
"<%s> received data on a disabled interface (%s)",
__func__,
if_indextoname(pi->ipi6_ifindex, ifnamebuf));
return;
}
#ifdef OLDRAWSOCKET
if (i < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr)) {
syslog(LOG_ERR,
"<%s> packet size(%d) is too short",
__func__, i);
return;
}
ip = (struct ip6_hdr *)rcvmhdr.msg_iov[0].iov_base;
icp = (struct icmp6_hdr *)(ip + 1); /* XXX: ext. hdr? */
#else
if (i < sizeof(struct icmp6_hdr)) {
syslog(LOG_ERR,
"<%s> packet size(%d) is too short",
__func__, i);
return;
}
icp = (struct icmp6_hdr *)rcvmhdr.msg_iov[0].iov_base;
#endif
switch (icp->icmp6_type) {
case ND_ROUTER_SOLICIT:
/*
* Message verification - RFC-2461 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,
"<%s> RS with invalid hop limit(%d) "
"received from %s on %s",
__func__, *hlimp,
inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
INET6_ADDRSTRLEN),
if_indextoname(pi->ipi6_ifindex, ifnamebuf));
return;
}
if (icp->icmp6_code) {
syslog(LOG_NOTICE,
"<%s> RS with invalid ICMP6 code(%d) "
"received from %s on %s",
__func__, icp->icmp6_code,
inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
INET6_ADDRSTRLEN),
if_indextoname(pi->ipi6_ifindex, ifnamebuf));
return;
}
if (i < sizeof(struct nd_router_solicit)) {
syslog(LOG_NOTICE,
"<%s> RS from %s on %s does not have enough "
"length (len = %d)",
__func__,
inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
INET6_ADDRSTRLEN),
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-2461 6.1.2
* XXX: there's a same dilemma as above...
*/
if (*hlimp != 255) {
syslog(LOG_NOTICE,
"<%s> RA with invalid hop limit(%d) "
"received from %s on %s",
__func__, *hlimp,
inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
INET6_ADDRSTRLEN),
if_indextoname(pi->ipi6_ifindex, ifnamebuf));
return;
}
if (icp->icmp6_code) {
syslog(LOG_NOTICE,
"<%s> RA with invalid ICMP6 code(%d) "
"received from %s on %s",
__func__, icp->icmp6_code,
inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
INET6_ADDRSTRLEN),
if_indextoname(pi->ipi6_ifindex, ifnamebuf));
return;
}
if (i < sizeof(struct nd_router_advert)) {
syslog(LOG_NOTICE,
"<%s> RA from %s on %s does not have enough "
"length (len = %d)",
__func__,
inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
INET6_ADDRSTRLEN),
if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
return;
}
ra_input(i, (struct nd_router_advert *)icp, pi, &rcvfrom);
break;
case ICMP6_ROUTER_RENUMBERING:
if (accept_rr == 0) {
syslog(LOG_ERR, "<%s> received a router renumbering "
"message, but not allowed to be accepted",
__func__);
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, "<%s> invalid icmp type(%d)",
__func__, 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], ifnamebuf[IFNAMSIZ];
union nd_opts ndopts;
struct rainfo *ra;
struct soliciter *sol;
syslog(LOG_DEBUG,
"<%s> RS received from %s on %s",
__func__,
inet_ntop(AF_INET6, &from->sin6_addr,
ntopbuf, INET6_ADDRSTRLEN),
if_indextoname(pi->ipi6_ifindex, ifnamebuf));
/* ND option check */
memset(&ndopts, 0, sizeof(ndopts));
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, INET6_ADDRSTRLEN),
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-2461 6.1.1)
*/
if (IN6_IS_ADDR_UNSPECIFIED(&from->sin6_addr) &&
ndopts.nd_opts_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;
}
ra = ralist;
while (ra != NULL) {
if (pi->ipi6_ifindex == ra->ifindex)
break;
ra = ra->next;
}
if (ra == NULL) {
syslog(LOG_INFO,
"<%s> RS received on non advertising interface(%s)",
__func__,
if_indextoname(pi->ipi6_ifindex, ifnamebuf));
goto done;
}
ra->rsinput++; /* increment statistics */
/*
* 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->addr = *from;
/* XXX RFC2553 need clarification on flowinfo */
sol->addr.sin6_flowinfo = 0;
sol->next = ra->soliciter;
ra->soliciter = sol;
}
/*
* If there is already a waiting RS packet, don't
* update the timer.
*/
if (ra->waiting++)
goto done;
set_short_delay(ra);
done:
free_ndopts(&ndopts);
return;
}
static void
set_short_delay(rai)
struct rainfo *rai;
{
long delay; /* must not be greater than 1000000 */
struct timeval interval, now, min_delay, tm_tmp, *rest;
/*
* 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. RFC2461 6.2.6
*/
delay = arc4random() % MAX_RA_DELAY_TIME;
interval.tv_sec = 0;
interval.tv_usec = delay;
rest = rtadvd_timer_rest(rai->timer);
if (TIMEVAL_LT(*rest, interval)) {
syslog(LOG_DEBUG, "<%s> random delay is larger than "
"the rest of 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, &rai->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, rai->timer);
}
static void
ra_input(int len, struct nd_router_advert *ra,
struct in6_pktinfo *pi, struct sockaddr_in6 *from)
{
struct rainfo *rai;
char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
union nd_opts ndopts;
char *on_off[] = {"OFF", "ON"};
u_int32_t reachabletime, retranstimer, mtu;
int inconsistent = 0;
syslog(LOG_DEBUG,
"<%s> RA received from %s on %s",
__func__,
inet_ntop(AF_INET6, &from->sin6_addr,
ntopbuf, INET6_ADDRSTRLEN),
if_indextoname(pi->ipi6_ifindex, ifnamebuf));
/* ND option check */
memset(&ndopts, 0, sizeof(ndopts));
if (nd6_options((struct nd_opt_hdr *)(ra + 1),
len - sizeof(struct nd_router_advert),
&ndopts, NDOPT_FLAG_SRCLINKADDR |
NDOPT_FLAG_PREFIXINFO | NDOPT_FLAG_MTU)) {
syslog(LOG_INFO,
"<%s> ND option check failed for an RA from %s on %s",
__func__,
inet_ntop(AF_INET6, &from->sin6_addr,
ntopbuf, INET6_ADDRSTRLEN),
if_indextoname(pi->ipi6_ifindex, ifnamebuf));
return;
}
/*
* RA consistency check according to RFC-2461 6.2.7
*/
if ((rai = if_indextorainfo(pi->ipi6_ifindex)) == 0) {
syslog(LOG_INFO,
"<%s> received RA from %s on non-advertising"
" interface(%s)",
__func__,
inet_ntop(AF_INET6, &from->sin6_addr,
ntopbuf, INET6_ADDRSTRLEN),
if_indextoname(pi->ipi6_ifindex, ifnamebuf));
goto done;
}
rai->rainput++; /* increment statistics */
/* Cur Hop Limit value */
if (ra->nd_ra_curhoplimit && rai->hoplimit &&
ra->nd_ra_curhoplimit != rai->hoplimit) {
syslog(LOG_INFO,
"<%s> CurHopLimit inconsistent on %s:"
" %d from %s, %d from us",
__func__,
rai->ifname,
ra->nd_ra_curhoplimit,
inet_ntop(AF_INET6, &from->sin6_addr,
ntopbuf, INET6_ADDRSTRLEN),
rai->hoplimit);
inconsistent++;
}
/* M flag */
if ((ra->nd_ra_flags_reserved & ND_RA_FLAG_MANAGED) !=
rai->managedflg) {
syslog(LOG_INFO,
"<%s> M flag inconsistent on %s:"
" %s from %s, %s from us",
__func__,
rai->ifname,
on_off[!rai->managedflg],
inet_ntop(AF_INET6, &from->sin6_addr,
ntopbuf, INET6_ADDRSTRLEN),
on_off[rai->managedflg]);
inconsistent++;
}
/* O flag */
if ((ra->nd_ra_flags_reserved & ND_RA_FLAG_OTHER) !=
rai->otherflg) {
syslog(LOG_INFO,
"<%s> O flag inconsistent on %s:"
" %s from %s, %s from us",
__func__,
rai->ifname,
on_off[!rai->otherflg],
inet_ntop(AF_INET6, &from->sin6_addr,
ntopbuf, INET6_ADDRSTRLEN),
on_off[rai->otherflg]);
inconsistent++;
}
/* Reachable Time */
reachabletime = ntohl(ra->nd_ra_reachable);
if (reachabletime && rai->reachabletime &&
reachabletime != rai->reachabletime) {
syslog(LOG_INFO,
"<%s> ReachableTime inconsistent on %s:"
" %d from %s, %d from us",
__func__,
rai->ifname,
reachabletime,
inet_ntop(AF_INET6, &from->sin6_addr,
ntopbuf, INET6_ADDRSTRLEN),
rai->reachabletime);
inconsistent++;
}
/* Retrans Timer */
retranstimer = ntohl(ra->nd_ra_retransmit);
if (retranstimer && rai->retranstimer &&
retranstimer != rai->retranstimer) {
syslog(LOG_INFO,
"<%s> RetranceTimer inconsistent on %s:"
" %d from %s, %d from us",
__func__,
rai->ifname,
retranstimer,
inet_ntop(AF_INET6, &from->sin6_addr,
ntopbuf, INET6_ADDRSTRLEN),
rai->retranstimer);
inconsistent++;
}
/* Values in the MTU options */
if (ndopts.nd_opts_mtu) {
mtu = ntohl(ndopts.nd_opts_mtu->nd_opt_mtu_mtu);
if (mtu && rai->linkmtu && mtu != rai->linkmtu) {
syslog(LOG_INFO,
"<%s> MTU option value inconsistent on %s:"
" %d from %s, %d from us",
__func__,
rai->ifname, mtu,
inet_ntop(AF_INET6, &from->sin6_addr,
ntopbuf, INET6_ADDRSTRLEN),
rai->linkmtu);
inconsistent++;
}
}