OpenBSD-4.6/usr.sbin/rtsold/rtsold.c
/* $OpenBSD: rtsold.c,v 1.45 2009/01/30 17:25:51 rainer Exp $ */
/* $KAME: rtsold.c,v 1.75 2004/01/03 00:00:07 itojun Exp $ */
/*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/types.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <sys/param.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <netinet/in.h>
#include <netinet/icmp6.h>
#include <signal.h>
#include <unistd.h>
#include <syslog.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <err.h>
#include <stdarg.h>
#include <ifaddrs.h>
#include <util.h>
#include <poll.h>
#include "rtsold.h"
struct ifinfo *iflist;
struct timeval tm_max = {0x7fffffff, 0x7fffffff};
static int log_upto = 999;
static int fflag = 0;
static int Fflag = 0; /* force setting sysctl parameters */
int aflag = 0;
int dflag = 0;
char *otherconf_script;
/* protocol constants */
#define MAX_RTR_SOLICITATION_DELAY 1 /* second */
#define RTR_SOLICITATION_INTERVAL 4 /* seconds */
#define MAX_RTR_SOLICITATIONS 3 /* times */
/*
* implementation dependent constants in seconds
* XXX: should be configurable
*/
#define PROBE_INTERVAL 60
int main(int, char **);
/* static variables and functions */
static int mobile_node = 0;
#ifndef SMALL
volatile sig_atomic_t do_dump;
static char *dumpfilename = "/var/run/rtsold.dump"; /* XXX: should be configurable */
#endif
#if 0
static int ifreconfig(char *);
#endif
int ifconfig(char *ifname);
static int make_packet(struct ifinfo *);
static struct timeval *rtsol_check_timer(void);
#ifndef SMALL
static void rtsold_set_dump_file(int);
#endif
static void usage(char *);
int
main(int argc, char *argv[])
{
int s, ch, once = 0;
struct timeval *timeout;
char *argv0, *opts;
struct pollfd set[2];
/*
* Initialization
*/
argv0 = argv[0];
/* get option */
if (argv0 && argv0[0] != '\0' && argv0[strlen(argv0) - 1] != 'd') {
fflag = 1;
once = 1;
opts = "adDFO:";
} else
opts = "adDfFm1O:";
while ((ch = getopt(argc, argv, opts)) != -1) {
switch (ch) {
case 'a':
aflag = 1;
break;
case 'd':
dflag = 1;
break;
case 'D':
dflag = 2;
break;
case 'f':
fflag = 1;
break;
case 'F':
Fflag = 1;
break;
case 'm':
mobile_node = 1;
break;
case '1':
once = 1;
break;
#ifndef SMALL
case 'O':
otherconf_script = optarg;
break;
#endif
default:
usage(argv0);
/*NOTREACHED*/
}
}
argc -= optind;
argv += optind;
if ((!aflag && argc == 0) || (aflag && argc != 0)) {
usage(argv0);
/*NOTREACHED*/
}
/* set log level */
if (dflag == 0)
log_upto = LOG_NOTICE;
if (!fflag) {
char *ident;
ident = strrchr(argv0, '/');
if (!ident)
ident = argv0;
else
ident++;
openlog(ident, LOG_NDELAY|LOG_PID, LOG_DAEMON);
if (log_upto >= 0)
setlogmask(LOG_UPTO(log_upto));
}
#ifndef SMALL
if (otherconf_script && *otherconf_script != '/') {
errx(1, "configuration script (%s) must be an absolute path",
otherconf_script);
}
#endif
if (Fflag) {
setinet6sysctl(IPV6CTL_ACCEPT_RTADV, 1);
setinet6sysctl(IPV6CTL_FORWARDING, 0);
} else {
/* warn if accept_rtadv is down */
if (!getinet6sysctl(IPV6CTL_ACCEPT_RTADV))
warnx("kernel is configured not to accept RAs");
/* warn if forwarding is up */
if (getinet6sysctl(IPV6CTL_FORWARDING))
warnx("kernel is configured as a router, not a host");
}
#ifndef SMALL
/* initialization to dump internal status to a file */
signal(SIGUSR1, rtsold_set_dump_file);
#endif
if (!fflag)
daemon(0, 0); /* act as a daemon */
/*
* Open a socket for sending RS and receiving RA.
* This should be done before calling ifinit(), since the function
* uses the socket.
*/
if ((s = sockopen()) < 0) {
warnmsg(LOG_ERR, __func__, "failed to open a socket");
exit(1);
/*NOTREACHED*/
}
set[0].fd = s;
set[0].events = POLLIN;
set[1].fd = -1;
/* configuration per interface */
if (ifinit()) {
warnmsg(LOG_ERR, __func__,
"failed to initialize interfaces");
exit(1);
/*NOTREACHED*/
}
if (aflag)
argv = autoifprobe();
while (argv && *argv) {
if (ifconfig(*argv)) {
warnmsg(LOG_ERR, __func__,
"failed to initialize %s", *argv);
exit(1);
/*NOTREACHED*/
}
argv++;
}
/* setup for probing default routers */
if (probe_init()) {
warnmsg(LOG_ERR, __func__,
"failed to setup for probing routers");
exit(1);
/*NOTREACHED*/
}
while (1) { /* main loop */
int e;
#ifndef SMALL
if (do_dump) { /* SIGUSR1 */
do_dump = 0;
rtsold_dump_file(dumpfilename);
}
#endif
timeout = rtsol_check_timer();
if (once) {
struct ifinfo *ifi;
/* if we have no timeout, we are done (or failed) */
if (timeout == NULL)
break;
/* if all interfaces have got RA packet, we are done */
for (ifi = iflist; ifi; ifi = ifi->next) {
if (ifi->state != IFS_DOWN && ifi->racnt == 0)
break;
}
if (ifi == NULL)
break;
}
e = poll(set, 2, timeout ? (timeout->tv_sec * 1000 + timeout->tv_usec / 1000) : INFTIM);
if (e < 1) {
if (e < 0 && errno != EINTR) {
warnmsg(LOG_ERR, __func__, "select: %s",
strerror(errno));
}
continue;
}
/* packet reception */
if (set[0].revents & POLLIN)
rtsol_input(s);
}
/* NOTREACHED */
return 0;
}
int
ifconfig(char *ifname)
{
struct ifinfo *ifinfo;
struct sockaddr_dl *sdl;
int flags;
if ((sdl = if_nametosdl(ifname)) == NULL) {
warnmsg(LOG_ERR, __func__,
"failed to get link layer information for %s", ifname);
return(-1);
}
if (find_ifinfo(sdl->sdl_index)) {
warnmsg(LOG_ERR, __func__,
"interface %s was already configured", ifname);
free(sdl);
return(-1);
}
if ((ifinfo = malloc(sizeof(*ifinfo))) == NULL) {
warnmsg(LOG_ERR, __func__, "memory allocation failed");
free(sdl);
return(-1);
}
memset(ifinfo, 0, sizeof(*ifinfo));
ifinfo->sdl = sdl;
strncpy(ifinfo->ifname, ifname, sizeof(ifinfo->ifname));
/* construct a router solicitation message */
if (make_packet(ifinfo))
goto bad;
/* set link ID of this interface. */
#ifdef HAVE_SCOPELIB
if (inet_zoneid(AF_INET6, 2, ifname, &ifinfo->linkid))
goto bad;
#else
/* XXX: assume interface IDs as link IDs */
ifinfo->linkid = ifinfo->sdl->sdl_index;
#endif
/*
* check if the interface is available.
* also check if SIOCGIFMEDIA ioctl is OK on the interface.
*/
ifinfo->mediareqok = 1;
ifinfo->active = interface_status(ifinfo);
if (!ifinfo->mediareqok) {
/*
* probe routers periodically even if the link status
* does not change.
*/
ifinfo->probeinterval = PROBE_INTERVAL;
}
/* activate interface: interface_up returns 0 on success */
flags = interface_up(ifinfo->ifname);
if (flags == 0)
ifinfo->state = IFS_DELAY;
else if (flags == IFS_TENTATIVE)
ifinfo->state = IFS_TENTATIVE;
else
ifinfo->state = IFS_DOWN;
rtsol_timer_update(ifinfo);
/* link into chain */
if (iflist)
ifinfo->next = iflist;
iflist = ifinfo;
return(0);
bad:
free(ifinfo->sdl);
free(ifinfo);
return(-1);
}
#if 0
static int
ifreconfig(char *ifname)
{
struct ifinfo *ifi, *prev;
int rv;
prev = NULL;
for (ifi = iflist; ifi; ifi = ifi->next) {
if (strncmp(ifi->ifname, ifname, sizeof(ifi->ifname)) == 0)
break;
prev = ifi;
}
prev->next = ifi->next;
rv = ifconfig(ifname);
/* reclaim it after ifconfig() in case ifname is pointer inside ifi */
if (ifi->rs_data)
free(ifi->rs_data);
free(ifi->sdl);
free(ifi);
return rv;
}
#endif
struct ifinfo *
find_ifinfo(int ifindex)
{
struct ifinfo *ifi;
for (ifi = iflist; ifi; ifi = ifi->next)
if (ifi->sdl->sdl_index == ifindex)
return(ifi);
return(NULL);
}
static int
make_packet(struct ifinfo *ifinfo)
{
size_t packlen = sizeof(struct nd_router_solicit), lladdroptlen = 0;
struct nd_router_solicit *rs;
char *buf;
if ((lladdroptlen = lladdropt_length(ifinfo->sdl)) == 0) {
warnmsg(LOG_INFO, __func__,
"link-layer address option has null length"
" on %s. Treat as not included.", ifinfo->ifname);
}
packlen += lladdroptlen;
ifinfo->rs_datalen = packlen;
/* allocate buffer */
if ((buf = malloc(packlen)) == NULL) {
warnmsg(LOG_ERR, __func__,
"memory allocation failed for %s", ifinfo->ifname);
return(-1);
}
ifinfo->rs_data = buf;
/* fill in the message */
rs = (struct nd_router_solicit *)buf;
rs->nd_rs_type = ND_ROUTER_SOLICIT;
rs->nd_rs_code = 0;
rs->nd_rs_cksum = 0;
rs->nd_rs_reserved = 0;
buf += sizeof(*rs);
/* fill in source link-layer address option */
if (lladdroptlen)
lladdropt_fill(ifinfo->sdl, (struct nd_opt_hdr *)buf);
return(0);
}
static struct timeval *
rtsol_check_timer(void)
{
static struct timeval returnval;
struct timeval now, rtsol_timer;
struct ifinfo *ifinfo;
int flags;
gettimeofday(&now, NULL);
rtsol_timer = tm_max;
for (ifinfo = iflist; ifinfo; ifinfo = ifinfo->next) {
if (timercmp(&ifinfo->expire, &now, <=)) {
if (dflag > 1)
warnmsg(LOG_DEBUG, __func__,
"timer expiration on %s, "
"state = %d", ifinfo->ifname,
ifinfo->state);
switch (ifinfo->state) {
case IFS_DOWN:
case IFS_TENTATIVE:
/* interface_up returns 0 on success */
flags = interface_up(ifinfo->ifname);
if (flags == 0)
ifinfo->state = IFS_DELAY;
else if (flags == IFS_TENTATIVE)
ifinfo->state = IFS_TENTATIVE;
else
ifinfo->state = IFS_DOWN;
break;
case IFS_IDLE:
{
int oldstatus = ifinfo->active;
int probe = 0;
ifinfo->active = interface_status(ifinfo);
if (oldstatus != ifinfo->active) {
warnmsg(LOG_DEBUG, __func__,
"%s status is changed"
" from %d to %d",
ifinfo->ifname,
oldstatus, ifinfo->active);
probe = 1;
ifinfo->state = IFS_DELAY;
} else if (ifinfo->probeinterval &&
(ifinfo->probetimer -=
ifinfo->timer.tv_sec) <= 0) {
/* probe timer expired */
ifinfo->probetimer =
ifinfo->probeinterval;
probe = 1;
ifinfo->state = IFS_PROBE;
}
#ifndef SMALL
/*
* If we need a probe, clear the previous
* status wrt the "other" configuration.
*/
if (probe)
ifinfo->otherconfig = 0;
#endif
if (probe && mobile_node)
defrouter_probe(ifinfo);
break;
}
case IFS_DELAY:
ifinfo->state = IFS_PROBE;
sendpacket(ifinfo);
break;
case IFS_PROBE:
if (ifinfo->probes < MAX_RTR_SOLICITATIONS)
sendpacket(ifinfo);
else {
warnmsg(LOG_INFO, __func__,
"No answer after sending %d RSs",
ifinfo->probes);
ifinfo->probes = 0;
ifinfo->state = IFS_IDLE;
}
break;
}
rtsol_timer_update(ifinfo);
}
if (timercmp(&ifinfo->expire, &rtsol_timer, <))
rtsol_timer = ifinfo->expire;
}
if (timercmp(&rtsol_timer, &tm_max, ==)) {
warnmsg(LOG_DEBUG, __func__, "there is no timer");
return(NULL);
} else if (timercmp(&rtsol_timer, &now, <))
/* this may occur when the interval is too small */
returnval.tv_sec = returnval.tv_usec = 0;
else
timersub(&rtsol_timer, &now, &returnval);
if (dflag > 1)
warnmsg(LOG_DEBUG, __func__, "New timer is %ld:%08ld",
(long)returnval.tv_sec, (long)returnval.tv_usec);
return(&returnval);
}
void
rtsol_timer_update(struct ifinfo *ifinfo)
{
#define MILLION 1000000
#define DADRETRY 10 /* XXX: adhoc */
long interval;
struct timeval now;
bzero(&ifinfo->timer, sizeof(ifinfo->timer));
switch (ifinfo->state) {
case IFS_DOWN:
case IFS_TENTATIVE:
if (++ifinfo->dadcount > DADRETRY) {
ifinfo->dadcount = 0;
ifinfo->timer.tv_sec = PROBE_INTERVAL;
} else
ifinfo->timer.tv_sec = 1;
break;
case IFS_IDLE:
if (mobile_node) {
/* XXX should be configurable */
ifinfo->timer.tv_sec = 3;
} else
ifinfo->timer = tm_max; /* stop timer(valid?) */
break;
case IFS_DELAY:
interval = arc4random_uniform(MAX_RTR_SOLICITATION_DELAY *
MILLION);
ifinfo->timer.tv_sec = interval / MILLION;
ifinfo->timer.tv_usec = interval % MILLION;
break;
case IFS_PROBE:
if (ifinfo->probes < MAX_RTR_SOLICITATIONS)
ifinfo->timer.tv_sec = RTR_SOLICITATION_INTERVAL;
else {
/*
* After sending MAX_RTR_SOLICITATIONS solicitations,
* we're just waiting for possible replies; there
* will be no more solicitation. Thus, we change
* the timer value to MAX_RTR_SOLICITATION_DELAY based
* on RFC 2461, Section 6.3.7.
*/
ifinfo->timer.tv_sec = MAX_RTR_SOLICITATION_DELAY;
}
break;
default:
warnmsg(LOG_ERR, __func__,
"illegal interface state(%d) on %s",
ifinfo->state, ifinfo->ifname);
return;
}
/* reset the timer */
if (timercmp(&ifinfo->timer, &tm_max, ==)) {
ifinfo->expire = tm_max;
warnmsg(LOG_DEBUG, __func__,
"stop timer for %s", ifinfo->ifname);
} else {
gettimeofday(&now, NULL);
timeradd(&now, &ifinfo->timer, &ifinfo->expire);
if (dflag > 1)
warnmsg(LOG_DEBUG, __func__,
"set timer for %s to %d:%d", ifinfo->ifname,
(int)ifinfo->timer.tv_sec,
(int)ifinfo->timer.tv_usec);
}
#undef MILLION
}
/* timer related utility functions */
#define MILLION 1000000
#ifndef SMALL
static void
rtsold_set_dump_file(int sig)
{
do_dump = 1;
}
#endif
static void
usage(char *progname)
{
if (progname && progname[0] != '\0' && progname[strlen(progname) - 1] != 'd') {
fprintf(stderr,
"usage: rtsol [-DdF] [-O script-name] interface ...\n"
" rtsol [-DdF] -a\n");
} else {
fprintf(stderr,
"usage: rtsold [-1DdFfm] [-O script-name] interface ...\n"
" rtsold [-1DdFfm] -a\n");
}
exit(1);
}
void
warnmsg(int priority, const char *func, const char *msg, ...)
{
va_list ap;
char buf[BUFSIZ];
va_start(ap, msg);
if (fflag) {
if (priority <= log_upto) {
(void)vfprintf(stderr, msg, ap);
(void)fprintf(stderr, "\n");
}
} else {
snprintf(buf, sizeof(buf), "<%s> %s", func, msg);
msg = buf;
vsyslog(priority, msg, ap);
}
va_end(ap);
}
/*
* return a list of interfaces which is suitable to sending an RS.
*/
char **
autoifprobe(void)
{
static char **argv = NULL;
static int n = 0;
char **a;
int i, found;
struct ifaddrs *ifap, *ifa, *target;
/* initialize */
while (n--)
free(argv[n]);
if (argv) {
free(argv);
argv = NULL;
}
n = 0;
if (getifaddrs(&ifap) != 0)
return NULL;
target = NULL;
/* find an ethernet */
for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
if ((ifa->ifa_flags & IFF_UP) == 0)
continue;
if ((ifa->ifa_flags & IFF_POINTOPOINT) != 0)
continue;
if ((ifa->ifa_flags & IFF_LOOPBACK) != 0)
continue;
if ((ifa->ifa_flags & IFF_MULTICAST) == 0)
continue;
if (ifa->ifa_addr->sa_family != AF_INET6)
continue;
found = 0;
for (i = 0; i < n; i++) {
if (strcmp(argv[i], ifa->ifa_name) == 0) {
found++;
break;
}
}
if (found)
continue;
/* if we find multiple candidates, just warn. */
if (n != 0 && dflag > 1)
warnx("multiple interfaces found");
a = (char **)realloc(argv, (n + 1) * sizeof(char **));
if (a == NULL)
err(1, "realloc");
argv = a;
if ((argv[n] = strdup(ifa->ifa_name)) == NULL)
err(1, "strdup");
n++;
}
if (n) {
a = (char **)realloc(argv, (n + 1) * sizeof(char **));
if (a == NULL)
err(1, "realloc");
argv = a;
argv[n] = NULL;
if (dflag > 0) {
for (i = 0; i < n; i++)
warnx("probing %s", argv[i]);
}
}
freeifaddrs(ifap);
return argv;
}