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freebsd-dev/usr.sbin/rtadvd/rtadvd.c
Andrey A. Chernov f90b161b21 Change 2 arc4random modulo operations to arc4random_uniform() as 
OpenBSD does, since modulo is not power of 2.

Obtained from:  OpenBSD
2008-07-26 15:39:32 +00:00

1690 lines
43 KiB
C
Raw Blame History

/* $FreeBSD$ */
/* $KAME: rtadvd.c,v 1.82 2003/08/05 12:34:23 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/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>
#ifdef HAVE_POLL_H
#include <poll.h>
#endif
#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 *pidfilename = "/var/run/rtadvd.pid"; /* should be configurable */
static char *mcastif;
int sock;
int rtsock = -1;
int accept_rr = 0;
int dflag = 0, sflag = 0;
u_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(int, char *[]);
static void set_die(int);
static void die(void);
static void sock_open(void);
static void rtsock_open(void);
static void rtadvd_input(void);
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_opts *, u_int32_t);
static void free_ndopts(union nd_opts *);
static void ra_output(struct rainfo *);
static void rtmsg_input(void);
static void rtadvd_set_dump_file(int);
static void set_short_delay(struct rainfo *);
int
main(argc, argv)
int argc;
char *argv[];
{
#ifdef HAVE_POLL_H
struct pollfd set[2];
#else
fd_set *fdsetp, *selectfdp;
int fdmasks;
int maxfd = 0;
#endif
struct timeval *timeout;
int i, ch;
int fflag = 0, logopt;
FILE *pidfp;
pid_t pid;
/* get command line options and arguments */
while ((ch = getopt(argc, argv, "c:dDfM:Rs")) != -1) {
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 conffile] "
"interfaces...\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();
#ifndef HAVE_ARC4RANDOM
/* random value initialization */
#ifdef __FreeBSD__
srandomdev();
#else
srandom((u_long)time(NULL));
#endif
#endif
/* 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 */
pid = getpid();
if ((pidfp = fopen(pidfilename, "w")) == NULL) {
syslog(LOG_ERR,
"<%s> failed to open the pid log file, run anyway.",
__func__);
} else {
fprintf(pidfp, "%d\n", pid);
fclose(pidfp);
}
#ifdef HAVE_POLL_H
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;
#else
maxfd = sock;
if (sflag == 0) {
rtsock_open();
if (rtsock > sock)
maxfd = rtsock;
} else
rtsock = -1;
fdmasks = howmany(maxfd + 1, NFDBITS) * sizeof(fd_mask);
if ((fdsetp = malloc(fdmasks)) == NULL) {
err(1, "malloc");
/*NOTREACHED*/
}
if ((selectfdp = malloc(fdmasks)) == NULL) {
err(1, "malloc");
/*NOTREACHED*/
}
memset(fdsetp, 0, fdmasks);
FD_SET(sock, fdsetp);
if (rtsock >= 0)
FD_SET(rtsock, fdsetp);
#endif
signal(SIGTERM, set_die);
signal(SIGUSR1, rtadvd_set_dump_file);
while (1) {
#ifndef HAVE_POLL_H
memcpy(selectfdp, fdsetp, fdmasks); /* reinitialize */
#endif
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__);
}
#ifdef HAVE_POLL_H
if ((i = poll(set, 2, timeout ? (timeout->tv_sec * 1000 +
timeout->tv_usec / 1000) : INFTIM)) < 0)
#else
if ((i = select(maxfd + 1, selectfdp, NULL, NULL,
timeout)) < 0)
#endif
{
/* EINTR would occur upon SIGUSR1 for status dump */
if (errno != EINTR)
syslog(LOG_ERR, "<%s> select: %s",
__func__, strerror(errno));
continue;
}
if (i == 0) /* timeout */
continue;
#ifdef HAVE_POLL_H
if (rtsock != -1 && set[1].revents & POLLIN)
#else
if (rtsock != -1 && FD_ISSET(rtsock, selectfdp))
#endif
rtmsg_input();
#ifdef HAVE_POLL_H
if (set[0].revents & POLLIN)
#else
if (FD_ISSET(sock, selectfdp))
#endif
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;
char msg[2048], *next, *lim;
u_char ifname[IF_NAMESIZE];
struct prefix *prefix;
struct rainfo *rai;
struct in6_addr *addr;
char addrbuf[INET6_ADDRSTRLEN];
int prefixchange = 0;
n = read(rtsock, msg, sizeof(msg));
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) && /* UP to DOWN */
!(iflist[ifindex]->ifm_flags & IFF_UP)) {
syslog(LOG_INFO,
"<%s> interface %s becomes down. stop timer.",
__func__, rai->ifname);
rtadvd_remove_timer(&rai->timer);
} else if (!(oldifflags & IFF_UP) && /* DOWN to UP */
(iflist[ifindex]->ifm_flags & IFF_UP)) {
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;
u_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)
{
u_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. RFC-2461 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(rai->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, &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;
u_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++;
}
}
/* Preferred and Valid Lifetimes for prefixes */
{
struct nd_optlist *optp = ndopts.nd_opts_list;
if (ndopts.nd_opts_pi) {
if (prefix_check(ndopts.nd_opts_pi, rai, from))
inconsistent++;
}
while (optp) {
if (prefix_check((struct nd_opt_prefix_info *)optp->opt,
rai, from))
inconsistent++;
optp = optp->next;
}
}
if (inconsistent)
rai->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)
{
u_int32_t preferred_time, valid_time;
struct prefix *pp;
int inconsistent = 0;
u_char ntopbuf[INET6_ADDRSTRLEN], prefixbuf[INET6_ADDRSTRLEN];
struct timeval now;
#if 0 /* impossible */
if (pinfo->nd_opt_pi_type != ND_OPT_PREFIX_INFORMATION)
return(0);
#endif
/*
* 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, INET6_ADDRSTRLEN),
pinfo->nd_opt_pi_prefix_len,
inet_ntop(AF_INET6, &from->sin6_addr,
ntopbuf, INET6_ADDRSTRLEN),
rai->ifname);
}
if ((pp = 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, INET6_ADDRSTRLEN),
pinfo->nd_opt_pi_prefix_len,
inet_ntop(AF_INET6, &from->sin6_addr,
ntopbuf, INET6_ADDRSTRLEN),
rai->ifname);
return(0);
}
preferred_time = ntohl(pinfo->nd_opt_pi_preferred_time);
if (pp->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 (!pp->timer && rai->clockskew &&
abs(preferred_time - pp->pltimeexpire) > rai->clockskew) {
syslog(LOG_INFO,
"<%s> preferred lifetime for %s/%d"
" (decr. in real time) inconsistent on %s:"
" %d from %s, %ld from us",
__func__,
inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
prefixbuf, INET6_ADDRSTRLEN),
pinfo->nd_opt_pi_prefix_len,
rai->ifname, preferred_time,
inet_ntop(AF_INET6, &from->sin6_addr,
ntopbuf, INET6_ADDRSTRLEN),
pp->pltimeexpire);
inconsistent++;
}
} else if (!pp->timer && preferred_time != pp->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, INET6_ADDRSTRLEN),
pinfo->nd_opt_pi_prefix_len,
rai->ifname, preferred_time,
inet_ntop(AF_INET6, &from->sin6_addr,
ntopbuf, INET6_ADDRSTRLEN),
pp->preflifetime);
}
valid_time = ntohl(pinfo->nd_opt_pi_valid_time);
if (pp->vltimeexpire) {
gettimeofday(&now, NULL);
valid_time += now.tv_sec;
if (!pp->timer && rai->clockskew &&
abs(valid_time - pp->vltimeexpire) > rai->clockskew) {
syslog(LOG_INFO,
"<%s> valid lifetime for %s/%d"
" (decr. in real time) inconsistent on %s:"
" %d from %s, %ld from us",
__func__,
inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
prefixbuf, INET6_ADDRSTRLEN),
pinfo->nd_opt_pi_prefix_len,
rai->ifname, preferred_time,
inet_ntop(AF_INET6, &from->sin6_addr,
ntopbuf, INET6_ADDRSTRLEN),
pp->vltimeexpire);
inconsistent++;
}
} else if (!pp->timer && valid_time != pp->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, INET6_ADDRSTRLEN),
pinfo->nd_opt_pi_prefix_len,
rai->ifname, valid_time,
inet_ntop(AF_INET6, &from->sin6_addr,
ntopbuf, INET6_ADDRSTRLEN),
pp->validlifetime);
inconsistent++;
}
return(inconsistent);
}
struct prefix *
find_prefix(struct rainfo *rai, struct in6_addr *prefix, int plen)
{
struct prefix *pp;
int bytelen, bitlen;
u_char bitmask;
for (pp = rai->prefix.next; pp != &rai->prefix; pp = pp->next) {
if (plen != pp->prefixlen)
continue;
bytelen = plen / 8;
bitlen = plen % 8;
bitmask = 0xff << (8 - bitlen);
if (memcmp((void *)prefix, (void *)&pp->prefix, bytelen))
continue;
if (bitlen == 0 ||
((prefix->s6_addr[bytelen] & bitmask) ==
(pp->prefix.s6_addr[bytelen] & bitmask))) {
return(pp);
}
}
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;
u_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_opts *ndopts, u_int32_t optflags)
{
int optlen = 0;
for (; limit > 0; limit -= optlen) {
if (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) {
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.
*/
if ((hdr->nd_opt_type == ND_OPT_MTU &&
(optlen != sizeof(struct nd_opt_mtu))) ||
((hdr->nd_opt_type == ND_OPT_PREFIX_INFORMATION &&
optlen != sizeof(struct nd_opt_prefix_info)))) {
syslog(LOG_INFO, "<%s> invalid option length",
__func__);
continue;
}
switch (hdr->nd_opt_type) {
case ND_OPT_TARGET_LINKADDR:
case ND_OPT_REDIRECTED_HEADER:
break; /* we don't care about these options */
case ND_OPT_SOURCE_LINKADDR:
case ND_OPT_MTU:
if (ndopts->nd_opt_array[hdr->nd_opt_type]) {
syslog(LOG_INFO,
"<%s> duplicated ND option (type = %d)",
__func__, hdr->nd_opt_type);
}
ndopts->nd_opt_array[hdr->nd_opt_type] = hdr;
break;
case ND_OPT_PREFIX_INFORMATION:
{
struct nd_optlist *pfxlist;
if (ndopts->nd_opts_pi == 0) {
ndopts->nd_opts_pi =
(struct nd_opt_prefix_info *)hdr;
continue;
}
if ((pfxlist = malloc(sizeof(*pfxlist))) == NULL) {
syslog(LOG_ERR, "<%s> can't allocate memory",
__func__);
goto bad;
}
pfxlist->next = ndopts->nd_opts_list;
pfxlist->opt = hdr;
ndopts->nd_opts_list = pfxlist;
break;
}
default: /* impossible */
break;
}
}
return(0);
bad:
free_ndopts(ndopts);
return(-1);
}
static void
free_ndopts(union nd_opts *ndopts)
{
struct nd_optlist *opt = ndopts->nd_opts_list, *next;
while (opt) {
next = opt->next;
free(opt);
opt = next;
}
}
void
sock_open()
{
struct icmp6_filter filt;
struct ipv6_mreq mreq;
struct rainfo *ra = ralist;
int on;
/* XXX: should be max MTU attached to the node */
static u_char answer[1500];
rcvcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
CMSG_SPACE(sizeof(int));
rcvcmsgbuf = (u_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 = (u_char *)malloc(sndcmsgbuflen);
if (sndcmsgbuf == NULL) {
syslog(LOG_ERR, "<%s> not enough core", __func__);
exit(1);
}
if ((sock = 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;
#ifdef IPV6_RECVPKTINFO
if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
sizeof(on)) < 0) {
syslog(LOG_ERR, "<%s> IPV6_RECVPKTINFO: %s",
__func__, strerror(errno));
exit(1);
}
#else /* old adv. API */
if (setsockopt(sock, IPPROTO_IPV6, IPV6_PKTINFO, &on,
sizeof(on)) < 0) {
syslog(LOG_ERR, "<%s> IPV6_PKTINFO: %s",
__func__, strerror(errno));
exit(1);
}
#endif
on = 1;
/* specify to tell value of hoplimit field of received IP6 hdr */
#ifdef IPV6_RECVHOPLIMIT
if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
sizeof(on)) < 0) {
syslog(LOG_ERR, "<%s> IPV6_RECVHOPLIMIT: %s",
__func__, strerror(errno));
exit(1);
}
#else /* old adv. API */
if (setsockopt(sock, IPPROTO_IPV6, IPV6_HOPLIMIT, &on,
sizeof(on)) < 0) {
syslog(LOG_ERR, "<%s> IPV6_HOPLIMIT: %s",
__func__, strerror(errno));
exit(1);
}
#endif
ICMP6_FILTER_SETBLOCKALL(&filt);
ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filt);
ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
if (accept_rr)
ICMP6_FILTER_SETPASS(ICMP6_ROUTER_RENUMBERING, &filt);
if (setsockopt(sock, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
sizeof(filt)) < 0) {
syslog(LOG_ERR, "<%s> IICMP6_FILTER: %s",
__func__, strerror(errno));
exit(1);
}
/*
* join all routers multicast address on each advertising interface.
*/
if (inet_pton(AF_INET6, ALLROUTERS_LINK,
&mreq.ipv6mr_multiaddr.s6_addr)
!= 1) {
syslog(LOG_ERR, "<%s> inet_pton failed(library bug?)",
__func__);
exit(1);
}
while (ra) {
mreq.ipv6mr_interface = ra->ifindex;
if (setsockopt(sock, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq,
sizeof(mreq)) < 0) {
syslog(LOG_ERR, "<%s> IPV6_JOIN_GROUP(link) on %s: %s",
__func__, ra->ifname, strerror(errno));
exit(1);
}
ra = ra->next;
}
/*
* When attending router renumbering, join all-routers site-local
* multicast group.
*/
if (accept_rr) {
if (inet_pton(AF_INET6, ALLROUTERS_SITE,
&in6a_site_allrouters) != 1) {
syslog(LOG_ERR, "<%s> inet_pton failed(library bug?)",
__func__);
exit(1);
}
mreq.ipv6mr_multiaddr = in6a_site_allrouters;
if (mcastif) {
if ((mreq.ipv6mr_interface = if_nametoindex(mcastif))
== 0) {
syslog(LOG_ERR,
"<%s> invalid interface: %s",
__func__, mcastif);
exit(1);
}
} else
mreq.ipv6mr_interface = ralist->ifindex;
if (setsockopt(sock, IPPROTO_IPV6, IPV6_JOIN_GROUP,
&mreq, sizeof(mreq)) < 0) {
syslog(LOG_ERR,
"<%s> IPV6_JOIN_GROUP(site) on %s: %s",
__func__,
mcastif ? mcastif : ralist->ifname,
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()
{
if ((rtsock = socket(PF_ROUTE, SOCK_RAW, 0)) < 0) {
syslog(LOG_ERR,
"<%s> socket: %s", __func__, strerror(errno));
exit(1);
}
}
struct rainfo *
if_indextorainfo(int idx)
{
struct rainfo *rai = ralist;
for (rai = ralist; rai; rai = rai->next) {
if (rai->ifindex == idx)
return(rai);
}
return(NULL); /* search failed */
}
static void
ra_output(rainfo)
struct rainfo *rainfo;
{
int i;
struct cmsghdr *cm;
struct in6_pktinfo *pi;
struct soliciter *sol, *nextsol;
if ((iflist[rainfo->ifindex]->ifm_flags & IFF_UP) == 0) {
syslog(LOG_DEBUG, "<%s> %s is not up, skip sending RA",
__func__, rainfo->ifname);
return;
}
make_packet(rainfo); /* XXX: inefficient */
sndmhdr.msg_name = (caddr_t)&sin6_allnodes;
sndmhdr.msg_iov[0].iov_base = (caddr_t)rainfo->ra_data;
sndmhdr.msg_iov[0].iov_len = rainfo->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 = rainfo->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 waitings = %d",
__func__, rainfo->ifname, rainfo->waiting);
i = sendmsg(sock, &sndmhdr, 0);
if (i < 0 || i != rainfo->ra_datalen) {
if (i < 0) {
syslog(LOG_ERR, "<%s> sendmsg on %s: %s",
__func__, rainfo->ifname,
strerror(errno));
}
}
/* update counter */
if (rainfo->initcounter < MAX_INITIAL_RTR_ADVERTISEMENTS)
rainfo->initcounter++;
rainfo->raoutput++;
/*
* unicast advertisements
* XXX commented out. reason: though spec does not forbit it, unicast
* advert does not really help
*/
for (sol = rainfo->soliciter; sol; sol = nextsol) {
nextsol = sol->next;
sol->next = NULL;
free(sol);
}
rainfo->soliciter = NULL;
/* update timestamp */
gettimeofday(&rainfo->lastsent, NULL);
/* reset waiting conter */
rainfo->waiting = 0;
}
/* process RA timer */
struct rtadvd_timer *
ra_timeout(void *data)
{
struct rainfo *rai = (struct rainfo *)data;
#ifdef notyet
/* if necessary, reconstruct the packet. */
#endif
syslog(LOG_DEBUG,
"<%s> RA timer on %s is expired",
__func__, rai->ifname);
ra_output(rai);
return(rai->timer);
}
/* update RA timer */
void
ra_timer_update(void *data, struct timeval *tm)
{
struct rainfo *rai = (struct rainfo *)data;
long interval;
/*
* 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 (RFC2461 6.2.4).
*/
interval = rai->mininterval;
#ifdef HAVE_ARC4RANDOM
interval += arc4random_uniform(rai->maxinterval - rai->mininterval);
#else
interval += random() % (rai->maxinterval - rai->mininterval);
#endif
/*
* 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-2461 6.2.4)
*/
if (rai->initcounter < MAX_INITIAL_RTR_ADVERTISEMENTS &&
interval > MAX_INITIAL_RTR_ADVERT_INTERVAL)
interval = MAX_INITIAL_RTR_ADVERT_INTERVAL;
tm->tv_sec = interval;
tm->tv_usec = 0;
syslog(LOG_DEBUG,
"<%s> RA timer on %s is set to %ld:%ld",
__func__, rai->ifname,
(long int)tm->tv_sec, (long int)tm->tv_usec);
return;
}
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