NetBSD-5.0.2/usr.sbin/mrouted/main.c
/* $NetBSD: main.c,v 1.23 2007/02/21 21:01:10 hubertf Exp $ */
/*
* The mrouted program is covered by the license in the accompanying file
* named "LICENSE". Use of the mrouted program represents acceptance of
* the terms and conditions listed in that file.
*
* The mrouted program is COPYRIGHT 1989 by The Board of Trustees of
* Leland Stanford Junior University.
*/
/*
* Written by Steve Deering, Stanford University, February 1989.
*
* (An earlier version of DVMRP was implemented by David Waitzman of
* BBN STC by extending Berkeley's routed program. Some of Waitzman's
* extensions have been incorporated into mrouted, but none of the
* original routed code has been adopted.)
*/
#include "defs.h"
#include <stdarg.h>
#include <fcntl.h>
#ifdef SNMP
#include "snmp.h"
#endif
#include <sys/cdefs.h>
#ifndef lint
__RCSID("@(#) $NetBSD: main.c,v 1.23 2007/02/21 21:01:10 hubertf Exp $");
#endif
#include <ctype.h>
#include <err.h>
#include <util.h>
extern char *configfilename;
char versionstring[100];
static char dumpfilename[] = _PATH_MROUTED_DUMP;
static char cachefilename[] = _PATH_MROUTED_CACHE;
static char genidfilename[] = _PATH_MROUTED_GENID;
int cache_lifetime = DEFAULT_CACHE_LIFETIME;
int max_prune_lifetime = DEFAULT_CACHE_LIFETIME * 2;
int debug = 0;
u_char pruning = 1; /* Enable pruning by default */
#ifdef SNMP
#define NHANDLERS 34
#else
#define NHANDLERS 2
#endif
static struct ihandler {
int fd; /* File descriptor */
ihfunc_t func; /* Function to call with &fd_set */
} ihandlers[NHANDLERS];
static int nhandlers = 0;
/*
* Forward declarations.
*/
static void fasttimer(int);
static void done(int);
static void dump(int);
static void fdump(int);
static void cdump(int);
static void restart(int);
static void timer(void);
static void cleanup(void);
static void resetlogging(void *);
/* To shut up gcc -Wstrict-prototypes */
int main(int argc, char *argv[]);
void logit(int severity, int syserr, const char *format, ...)
__attribute__((__format__(__printf__, 3, 4)));
int
register_input_handler(int fd, ihfunc_t func)
{
if (nhandlers >= NHANDLERS)
return -1;
ihandlers[nhandlers].fd = fd;
ihandlers[nhandlers++].func = func;
return 0;
}
int
main(int argc, char *argv[])
{
int recvlen;
int omask;
socklen_t dummy;
FILE *fp;
struct timeval tv;
u_int32_t prev_genid;
int vers;
fd_set rfds, readers;
int nfds, n, i;
#ifdef SNMP
struct timeval timeout, *tvp = &timeout;
struct timeval sched, *svp = &sched, now, *nvp = &now;
int index, block;
#endif
setlinebuf(stderr);
if (geteuid() != 0) {
fprintf(stderr, "must be root\n");
exit(1);
}
argv++, argc--;
while (argc > 0 && *argv[0] == '-') {
if (strcmp(*argv, "-d") == 0) {
if (argc > 1 && isdigit((unsigned char)*(argv + 1)[0])) {
argv++, argc--;
debug = atoi(*argv);
} else
debug = DEFAULT_DEBUG;
} else if (strcmp(*argv, "-c") == 0) {
if (argc > 1) {
argv++, argc--;
configfilename = *argv;
} else
goto usage;
} else if (strcmp(*argv, "-p") == 0) {
pruning = 0;
#ifdef SNMP
} else if (strcmp(*argv, "-P") == 0) {
if (argc > 1 && isdigit(*(argv + 1)[0])) {
argv++, argc--;
dest_port = atoi(*argv);
} else
dest_port = DEFAULT_PORT;
#endif
} else
goto usage;
argv++, argc--;
}
if (argc > 0) {
usage: fprintf(stderr,
"usage: mrouted [-p] [-c configfile] [-d [debug_level]]\n");
exit(1);
}
if (debug == 0) {
/*
* Detach from the terminal
*/
if (daemon(0, 0))
err(1, "can't fork");
pidfile(NULL);
}
else
fprintf(stderr, "debug level %u\n", debug);
#ifdef LOG_DAEMON
(void)openlog("mrouted", LOG_PID, LOG_DAEMON);
(void)setlogmask(LOG_UPTO(LOG_NOTICE));
#else
(void)openlog("mrouted", LOG_PID);
#endif
snprintf(versionstring, sizeof(versionstring),
"mrouted version %d.%d", PROTOCOL_VERSION, MROUTED_VERSION);
logit(LOG_NOTICE, 0, "%s", versionstring);
/*
* Get generation id
*/
gettimeofday(&tv, 0);
dvmrp_genid = tv.tv_sec;
fp = fopen(genidfilename, "r");
if (fp != NULL) {
fscanf(fp, "%d", &prev_genid);
if (prev_genid == dvmrp_genid)
dvmrp_genid++;
(void) fclose(fp);
}
fp = fopen(genidfilename, "w");
if (fp != NULL) {
fprintf(fp, "%d", dvmrp_genid);
(void) fclose(fp);
}
callout_init();
init_igmp();
init_routes();
init_ktable();
k_init_dvmrp(); /* enable DVMRP routing in kernel */
#ifndef OLD_KERNEL
vers = k_get_version();
/*XXX
* This function must change whenever the kernel version changes
*/
if ((((vers >> 8) & 0xff) != 3) ||
((vers & 0xff) != 5))
logit(LOG_ERR, 0, "kernel (v%d.%d)/mrouted (v%d.%d) version mismatch",
(vers >> 8) & 0xff, vers & 0xff,
PROTOCOL_VERSION, MROUTED_VERSION);
#endif
#ifdef SNMP
if (i = snmp_init())
return i;
gettimeofday(nvp, 0);
if (nvp->tv_usec < 500000L){
svp->tv_usec = nvp->tv_usec + 500000L;
svp->tv_sec = nvp->tv_sec;
} else {
svp->tv_usec = nvp->tv_usec - 500000L;
svp->tv_sec = nvp->tv_sec + 1;
}
#endif /* SNMP */
init_vifs();
#ifdef RSRR
rsrr_init();
#endif /* RSRR */
/*
* Allow cleanup if unexpected exit. Apparently some architectures
* have a kernel bug where closing the socket doesn't do an
* ip_mrouter_done(), so we attempt to do it on exit.
*/
atexit(cleanup);
if (debug)
fprintf(stderr, "pruning %s\n", pruning ? "on" : "off");
(void)signal(SIGALRM, fasttimer);
(void)signal(SIGHUP, restart);
(void)signal(SIGTERM, done);
(void)signal(SIGINT, done);
(void)signal(SIGUSR1, fdump);
(void)signal(SIGUSR2, cdump);
if (debug != 0)
(void)signal(SIGQUIT, dump);
FD_ZERO(&readers);
if (igmp_socket >= FD_SETSIZE)
logit(LOG_ERR, 0, "descriptor too big");
FD_SET(igmp_socket, &readers);
nfds = igmp_socket + 1;
for (i = 0; i < nhandlers; i++) {
if (ihandlers[i].fd >= FD_SETSIZE)
logit(LOG_ERR, 0, "descriptor too big");
FD_SET(ihandlers[i].fd, &readers);
if (ihandlers[i].fd >= nfds)
nfds = ihandlers[i].fd + 1;
}
/*
* Install the vifs in the kernel as late as possible in the
* initialization sequence.
*/
init_installvifs();
if (debug >= 2) dump(0);
/* Start up the log rate-limiter */
resetlogging(NULL);
(void)alarm(1); /* schedule first timer interrupt */
/*
* Main receive loop.
*/
for(;;) {
#ifdef SYSV
sigset_t block, oblock;
#endif
bcopy((char *)&readers, (char *)&rfds, sizeof(rfds));
#ifdef SNMP
gettimeofday(nvp, 0);
if (nvp->tv_sec > svp->tv_sec
|| (nvp->tv_sec == svp->tv_sec && nvp->tv_usec > svp->tv_usec)){
alarmTimer(nvp);
eventTimer(nvp);
if (nvp->tv_usec < 500000L){
svp->tv_usec = nvp->tv_usec + 500000L;
svp->tv_sec = nvp->tv_sec;
} else {
svp->tv_usec = nvp->tv_usec - 500000L;
svp->tv_sec = nvp->tv_sec + 1;
}
}
tvp = &timeout;
tvp->tv_sec = 0;
tvp->tv_usec = 500000L;
block = 0;
snmp_select_info(&nfds, &rfds, tvp, &block);
if (block == 1)
tvp = NULL; /* block without timeout */
if ((n = select(nfds, &rfds, NULL, NULL, tvp)) < 0)
#else
if ((n = select(nfds, &rfds, NULL, NULL, NULL)) < 0)
#endif
{
if (errno != EINTR) /* SIGALRM is expected */
logit(LOG_WARNING, errno, "select failed");
continue;
}
if (FD_ISSET(igmp_socket, &rfds)) {
recvlen = recvfrom(igmp_socket, recv_buf, RECV_BUF_SIZE,
0, NULL, &dummy);
if (recvlen < 0) {
if (errno != EINTR) logit(LOG_ERR, errno, "recvfrom");
continue;
}
#ifdef SYSV
(void)sigemptyset(&block);
(void)sigaddset(&block, SIGALRM);
if (sigprocmask(SIG_BLOCK, &block, &oblock) < 0)
logit(LOG_ERR, errno, "sigprocmask");
#else
omask = sigblock(sigmask(SIGALRM));
#endif
accept_igmp(recvlen);
#ifdef SYSV
(void)sigprocmask(SIG_SETMASK, &oblock, (sigset_t *)NULL);
#else
(void)sigsetmask(omask);
#endif
}
for (i = 0; i < nhandlers; i++) {
if (FD_ISSET(ihandlers[i].fd, &rfds)) {
(*ihandlers[i].func)(ihandlers[i].fd, &rfds);
}
}
#ifdef SNMP
snmp_read(&rfds);
snmp_timeout(); /* poll */
#endif
}
}
/*
* routine invoked every second. Its main goal is to cycle through
* the routing table and send partial updates to all neighbors at a
* rate that will cause the entire table to be sent in ROUTE_REPORT_INTERVAL
* seconds. Also, every TIMER_INTERVAL seconds it calls timer() to
* do all the other time-based processing.
*/
static void
fasttimer(int i)
{
static unsigned int tlast;
static unsigned int nsent;
unsigned int t = tlast + 1;
int n;
/*
* if we're in the last second, send everything that's left.
* otherwise send at least the fraction we should have sent by now.
*/
if (t >= ROUTE_REPORT_INTERVAL) {
int nleft = nroutes - nsent;
while (nleft > 0) {
if ((n = report_next_chunk()) <= 0)
break;
nleft -= n;
}
tlast = 0;
nsent = 0;
} else {
unsigned int ncum = nroutes * t / ROUTE_REPORT_INTERVAL;
while (nsent < ncum) {
if ((n = report_next_chunk()) <= 0)
break;
nsent += n;
}
tlast = t;
}
if ((t % TIMER_INTERVAL) == 0)
timer();
age_callout_queue();/* Advance the timer for the callout queue
for groups */
alarm(1);
}
/*
* The 'virtual_time' variable is initialized to a value that will cause the
* first invocation of timer() to send a probe or route report to all vifs
* and send group membership queries to all subnets for which this router is
* querier. This first invocation occurs approximately TIMER_INTERVAL seconds
* after the router starts up. Note that probes for neighbors and queries
* for group memberships are also sent at start-up time, as part of initial-
* ization. This repetition after a short interval is desirable for quickly
* building up topology and membership information in the presence of possible
* packet loss.
*
* 'virtual_time' advances at a rate that is only a crude approximation of
* real time, because it does not take into account any time spent processing,
* and because the timer intervals are sometimes shrunk by a random amount to
* avoid unwanted synchronization with other routers.
*/
static u_long virtual_time = 0;
/*
* Timer routine. Performs periodic neighbor probing, route reporting, and
* group querying duties, and drives various timers in routing entries and
* virtual interface data structures.
*/
static void
timer(void)
{
age_routes(); /* Advance the timers in the route entries */
age_vifs(); /* Advance the timers for neighbors */
age_table_entry(); /* Advance the timers for the cache entries */
if (virtual_time % GROUP_QUERY_INTERVAL == 0) {
/*
* Time to query the local group memberships on all subnets
* for which this router is the elected querier.
*/
query_groups();
}
if (virtual_time % NEIGHBOR_PROBE_INTERVAL == 0) {
/*
* Time to send a probe on all vifs from which no neighbors have
* been heard. Also, check if any inoperative interfaces have now
* come up. (If they have, they will also be probed as part of
* their initialization.)
*/
probe_for_neighbors();
if (vifs_down)
check_vif_state();
}
delay_change_reports = FALSE;
if (routes_changed) {
/*
* Some routes have changed since the last timer interrupt, but
* have not been reported yet. Report the changed routes to all
* neighbors.
*/
report_to_all_neighbors(CHANGED_ROUTES);
}
#ifdef SNMP
sync_timer();
#endif
/*
* Advance virtual time
*/
virtual_time += TIMER_INTERVAL;
}
/*
* On termination, let everyone know we're going away.
*/
static void
done(int i)
{
logit(LOG_NOTICE, 0, "%s exiting", versionstring);
cleanup();
_exit(1);
}
static void
cleanup(void)
{
static int in_cleanup = 0;
if (!in_cleanup) {
in_cleanup++;
#ifdef RSRR
rsrr_clean();
#endif /* RSRR */
expire_all_routes();
report_to_all_neighbors(ALL_ROUTES);
k_stop_dvmrp();
}
}
/*
* Dump internal data structures to stderr.
*/
static void
dump(int i)
{
dump_vifs(stderr);
dump_routes(stderr);
}
/*
* Dump internal data structures to a file.
*/
static void
fdump(int i)
{
FILE *fp;
fp = fopen(dumpfilename, "w");
if (fp != NULL) {
dump_vifs(fp);
dump_routes(fp);
(void) fclose(fp);
}
}
/*
* Dump local cache contents to a file.
*/
static void
cdump(int i)
{
FILE *fp;
fp = fopen(cachefilename, "w");
if (fp != NULL) {
dump_cache(fp);
(void) fclose(fp);
}
}
/*
* Restart mrouted
*/
static void
restart(int i)
{
int omask;
#ifdef SYSV
sigset_t block, oblock;
#endif
logit(LOG_NOTICE, 0, "%s restart", versionstring);
/*
* reset all the entries
*/
#ifdef SYSV
(void)sigemptyset(&block);
(void)sigaddset(&block, SIGALRM);
if (sigprocmask(SIG_BLOCK, &block, &oblock) < 0)
logit(LOG_ERR, errno, "sigprocmask");
#else
omask = sigblock(sigmask(SIGALRM));
#endif
free_all_prunes();
free_all_routes();
stop_all_vifs();
k_stop_dvmrp();
close(igmp_socket);
close(udp_socket);
/*
* start processing again
*/
dvmrp_genid++;
pruning = 1;
init_igmp();
init_routes();
init_ktable();
init_vifs();
k_init_dvmrp(); /* enable DVMRP routing in kernel */
init_installvifs();
#ifdef SYSV
(void)sigprocmask(SIG_SETMASK, &oblock, (sigset_t *)NULL);
#else
(void)sigsetmask(omask);
#endif
}
#define LOG_MAX_MSGS 20 /* if > 20/minute then shut up for a while */
#define LOG_SHUT_UP 600 /* shut up for 10 minutes */
static int log_nmsgs = 0;
static void
resetlogging(void *arg)
{
int nxttime = 60;
void *narg = NULL;
if (arg == NULL && log_nmsgs > LOG_MAX_MSGS) {
nxttime = LOG_SHUT_UP;
narg = (void *)&log_nmsgs; /* just need some valid void * */
syslog(LOG_WARNING, "logging too fast, shutting up for %d minutes",
LOG_SHUT_UP / 60);
} else {
log_nmsgs = 0;
}
timer_setTimer(nxttime, resetlogging, narg);
}
/*
* Log errors and other messages to the system log daemon and to stderr,
* according to the severity of the message and the current debug level.
* For errors of severity LOG_ERR or worse, terminate the program.
*/
void
logit(int severity, int syserr, const char *format, ...)
{
va_list ap;
static char fmt[211] = "warning - ";
char *msg;
char tbuf[20];
struct timeval now;
struct tm *thyme;
time_t t;
va_start(ap, format);
vsnprintf(&fmt[10], sizeof(fmt) - 10, format, ap);
va_end(ap);
msg = (severity == LOG_WARNING) ? fmt : &fmt[10];
switch (debug) {
case 0: break;
case 1: if (severity > LOG_NOTICE) break;
case 2: if (severity > LOG_INFO ) break;
default:
gettimeofday(&now,NULL);
t = now.tv_sec;
thyme = localtime(&t);
strftime(tbuf, sizeof(tbuf), "%X", thyme);
fprintf(stderr, "%s.%03ld %s", tbuf, (long)now.tv_usec / 1000,
msg);
if (syserr == 0)
fprintf(stderr, "\n");
else
fprintf(stderr, ": %s\n", strerror(syserr));
}
if (severity <= LOG_NOTICE) {
if (log_nmsgs++ < LOG_MAX_MSGS) {
if (syserr != 0) {
errno = syserr;
syslog(severity, "%s: %m", msg);
} else
syslog(severity, "%s", msg);
}
if (severity <= LOG_ERR) exit(1);
}
}
#ifdef DEBUG_MFC
void
md_log(int what, u_int32_t origin, u_int32_t mcastgrp)
{
static FILE *f = NULL;
struct timeval tv;
u_int32_t buf[4];
if (!f) {
if ((f = fopen("/tmp/mrouted.clog", "w")) == NULL) {
logit(LOG_ERR, errno, "open /tmp/mrouted.clog");
}
}
gettimeofday(&tv, NULL);
buf[0] = tv.tv_sec;
buf[1] = what;
buf[2] = origin;
buf[3] = mcastgrp;
fwrite(buf, sizeof(u_int32_t), 4, f);
}
#endif