NetBSD/usr.sbin/mrouted/main.c

613 lines
13 KiB
C

/*
* 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.
*
*
* $Id: main.c,v 1.4 1995/06/01 02:25:57 mycroft Exp $
*/
/*
* 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 <string.h>
#include <varargs.h>
#ifdef SNMP
#include "snmp.h"
#endif
extern char *configfilename;
static char pidfilename[] = _PATH_MROUTED_PID;
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 */
#define NHANDLERS 2
static struct ihandler {
int fd; /* File descriptor */
void (*func)(); /* Function to call with &fd_set */
} ihandlers[NHANDLERS];
static int nhandlers = 0;
/*
* Forward declarations.
*/
static void fasttimer();
static void timer();
static void cleanup();
static void done();
static void dump();
static void fdump();
static void cdump();
static void restart();
int
register_input_handler(fd, func)
int fd;
void (*func)();
{
if (nhandlers >= NHANDLERS)
return -1;
ihandlers[nhandlers].fd = fd;
ihandlers[nhandlers++].func = func;
return 0;
}
int main(argc, argv)
int argc;
char *argv[];
{
register int recvlen;
register int omask;
int dummy;
FILE *fp;
extern uid_t geteuid();
struct timeval tv;
u_long prev_genid;
int vers;
fd_set rfds, readers;
int nfds, n, i;
#ifdef SNMP
char *myname;
fd_set wfds;
if (myname = strrchr(argv[0], '/'))
myname++;
if (myname == NULL || *myname == 0)
myname = argv[0];
isodetailor (myname, 0);
#endif
#ifdef SYSV
setvbuf(stderr, NULL, _IOLBF, 0);
#else
setlinebuf(stderr);
#endif
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(*(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;
} 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
*/
int t;
if (fork()) exit(0);
(void)close(0);
(void)close(1);
(void)close(2);
(void)open("/", 0);
(void)dup2(0, 1);
(void)dup2(0, 2);
#ifdef TIOCNOTTY
t = open("/dev/tty", 2);
if (t >= 0) {
(void)ioctl(t, TIOCNOTTY, (char *)0);
(void)close(t);
}
#else
if (setsid() < 0)
perror("setsid");
#endif
}
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
log(LOG_NOTICE, 0, "mrouted version %d.%d",
PROTOCOL_VERSION, MROUTED_VERSION);
#ifdef SYSV
srand48(time(NULL));
#else
srandom(gethostid());
#endif
/*
* 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();
#ifdef SNMP
snmp_init();
#endif
init_igmp();
k_init_dvmrp(); /* enable DVMRP routing in kernel */
#ifndef OLD_KERNEL
vers = k_get_version();
if ((((vers >> 8) & 0xff) != PROTOCOL_VERSION) ||
((vers & 0xff) != MROUTED_VERSION))
log(LOG_ERR, 0, "kernel (v%d.%d)/mrouted (v%d.%d) version mismatch",
(vers >> 8) & 0xff, vers & 0xff,
PROTOCOL_VERSION, MROUTED_VERSION);
#endif
init_routes();
init_ktable();
init_vifs();
#ifdef RSRR
rsrr_init();
#endif /* RSRR */
#if defined(__STDC__) || defined(__GNUC__)
/* 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);
#endif
if (debug)
fprintf(stderr, "pruning %s\n", pruning ? "on" : "off");
fp = fopen(pidfilename, "w");
if (fp != NULL) {
fprintf(fp, "%d\n", getpid());
(void) fclose(fp);
}
if (debug >= 2) dump();
(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);
FD_SET(igmp_socket, &readers);
nfds = igmp_socket + 1;
for (i = 0; i < nhandlers; i++) {
FD_SET(ihandlers[i].fd, &readers);
if (ihandlers[i].fd >= nfds)
nfds = ihandlers[i].fd + 1;
}
(void)alarm(1); /* schedule first timer interrupt */
/*
* Main receive loop.
*/
dummy = 0;
for(;;) {
bcopy((char *)&readers, (char *)&rfds, sizeof(rfds));
#ifdef SNMP
FD_ZERO(&wfds);
if (smux_fd != NOTOK) {
if (rock_and_roll)
FD_SET(smux_fd, &rfds);
else
FD_SET(smux_fd, &wfds);
if (smux_fd >= nfds)
nfds = smux_fd + 1;
}
if ((n = xselect(nfds, &rfds, &wfds, NULLFD, NOTOK))==NOTOK) {
#else
if ((n = select(nfds, &rfds, NULL, NULL, NULL)) < 0) {
#endif
if (errno != EINTR) /* SIGALRM is expected */
log(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) log(LOG_ERR, errno, "recvfrom");
continue;
}
omask = sigblock(sigmask(SIGALRM));
accept_igmp(recvlen);
(void)sigsetmask(omask);
}
for (i = 0; i < nhandlers; i++) {
if (FD_ISSET(ihandlers[i].fd, &rfds)) {
(*ihandlers[i].func)(&rfds);
}
}
#ifdef SNMP
if (smux_fd != NOTOK) {
if (rock_and_roll) {
if (FD_ISSET(smux_fd, &rfds))
doit_smux();
} else if (FD_ISSET(smux_fd, &wfds))
start_smux();
}
#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()
{
static unsigned int tlast;
static unsigned int nsent;
register unsigned int t = tlast + 1;
register 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) {
register int nleft = nroutes - nsent;
while (nleft > 0) {
if ((n = report_next_chunk()) <= 0)
break;
nleft -= n;
}
tlast = 0;
nsent = 0;
} else {
register 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()
{
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
if (smux_fd == NOTOK && !dont_bother_anymore
&& virtual_time % SNMPD_RETRY_INTERVAL == 0) {
/*
* Time to check for snmpd running.
*/
try_smux_init();
}
#endif
/*
* Advance virtual time
*/
virtual_time += TIMER_INTERVAL;
}
/*
* On termination, let everyone know we're going away.
*/
static void
done()
{
log(LOG_NOTICE, 0, "mrouted version %d.%d exiting",
PROTOCOL_VERSION, MROUTED_VERSION);
cleanup();
_exit(1);
}
static void
cleanup()
{
static 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()
{
dump_vifs(stderr);
dump_routes(stderr);
}
/*
* Dump internal data structures to a file.
*/
static void
fdump()
{
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()
{
FILE *fp;
fp = fopen(cachefilename, "w");
if (fp != NULL) {
dump_cache(fp);
(void) fclose(fp);
}
}
/*
* Restart mrouted
*/
static void
restart()
{
register int omask;
log(LOG_NOTICE, 0, "mrouted version %d.%d restart",
PROTOCOL_VERSION, MROUTED_VERSION);
/*
* reset all the entries
*/
omask = sigblock(sigmask(SIGALRM));
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();
k_init_dvmrp(); /* enable DVMRP routing in kernel */
init_routes();
init_ktable();
init_vifs();
(void)sigsetmask(omask);
}
/*
* 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.
*/
/*VARARGS3*/
void
log(severity, syserr, format, va_alist)
int severity, syserr;
char *format;
va_dcl
{
va_list ap;
static char fmt[211] = "warning - ";
char *msg;
char tbuf[20];
struct timeval now;
struct tm *thyme;
va_start(ap);
vsprintf(&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);
thyme = localtime((time_t *)&now.tv_sec);
strftime(tbuf, sizeof(tbuf), "%X.%%03d ", thyme);
fprintf(stderr, tbuf, now.tv_usec / 1000);
fprintf(stderr, "%s", msg);
if (syserr == 0)
fprintf(stderr, "\n");
else
fprintf(stderr, ": %s\n", strerror(syserr));
}
if (severity <= LOG_NOTICE) {
if (syserr != 0) {
errno = syserr;
syslog(severity, "%s: %m", msg);
} else
syslog(severity, "%s", msg);
if (severity <= LOG_ERR) exit(-1);
}
}