main.c

早期freebsd实现

/*
 * Copyright (c) 1985, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This file includes significant work done at Cornell University by
 * Bill Nesheim.  That work included by permission.
 *
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
 */

#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1985, 1993\n\
	The Regents of the University of California.  All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)main.c	8.1 (Berkeley) 6/5/93";
#endif /* not lint */

/*
 * XNS Routing Information Protocol Daemon
 */
#include "defs.h"
#include <sys/time.h>

#include <net/if.h>

#include <errno.h>
#include <nlist.h>
#include <signal.h>
#include <paths.h>

int	supplier = -1;		/* process should supply updates */
extern int gateway;

struct	rip *msg = (struct rip *) &packet[sizeof (struct idp)]; 
void	hup(), fkexit(), timer();

main(argc, argv)
	int argc;
	char *argv[];
{
	int cc;
	struct sockaddr from;
	u_char retry;
	
	argv0 = argv;
	argv++, argc--;
	while (argc > 0 && **argv == '-') {
		if (strcmp(*argv, "-s") == 0) {
			supplier = 1;
			argv++, argc--;
			continue;
		}
		if (strcmp(*argv, "-q") == 0) {
			supplier = 0;
			argv++, argc--;
			continue;
		}
		if (strcmp(*argv, "-R") == 0) {
			noteremoterequests++;
			argv++, argc--;
			continue;
		}
		if (strcmp(*argv, "-t") == 0) {
			tracepackets++;
			argv++, argc--;
			ftrace = stderr;
			tracing = 1; 
			continue;
		}
		if (strcmp(*argv, "-g") == 0) {
			gateway = 1;
			argv++, argc--;
			continue;
		}
		if (strcmp(*argv, "-l") == 0) {
			gateway = -1;
			argv++, argc--;
			continue;
		}
		fprintf(stderr,
			"usage: xnsrouted [ -s ] [ -q ] [ -t ] [ -g ] [ -l ]\n");
		exit(1);
	}
	
	
#ifndef DEBUG
	if (!tracepackets)
		daemon(0, 0);
#endif
	openlog("XNSrouted", LOG_PID, LOG_DAEMON);

	addr.sns_family = AF_NS;
	addr.sns_len = sizeof(addr);
	addr.sns_port = htons(IDPPORT_RIF);
	ns_anynet.s_net[0] = ns_anynet.s_net[1] = -1;
	ns_netmask.sns_addr.x_net = ns_anynet;
	ns_netmask.sns_len = 6;
	r = socket(AF_ROUTE, SOCK_RAW, 0);
	/* later, get smart about lookingforinterfaces */
	if (r)
		shutdown(r, 0); /* for now, don't want reponses */
	else {
		fprintf(stderr, "routed: no routing socket\n");
		exit(1);
	}
	s = getsocket(SOCK_DGRAM, 0, &addr);
	if (s < 0)
		exit(1);
	/*
	 * Any extra argument is considered
	 * a tracing log file.
	 */
	if (argc > 0)
		traceon(*argv);
	/*
	 * Collect an initial view of the world by
	 * snooping in the kernel.  Then, send a request packet on all
	 * directly connected networks to find out what
	 * everyone else thinks.
	 */
	rtinit();
	ifinit();
	if (supplier < 0)
		supplier = 0;
	/* request the state of the world */
	msg->rip_cmd = htons(RIPCMD_REQUEST);
	msg->rip_nets[0].rip_dst = ns_anynet;
	msg->rip_nets[0].rip_metric =  htons(HOPCNT_INFINITY);
	toall(sndmsg);
	signal(SIGALRM, timer);
	signal(SIGHUP, hup);
	signal(SIGINT, hup);
	signal(SIGEMT, fkexit);
	timer();
	

	for (;;) 
		process(s);
	
}

process(fd)
	int fd;
{
	struct sockaddr from;
	int fromlen = sizeof (from), cc, omask;
	struct idp *idp = (struct idp *)packet;

	cc = recvfrom(fd, packet, sizeof (packet), 0, &from, &fromlen);
	if (cc <= 0) {
		if (cc < 0 && errno != EINTR)
			syslog(LOG_ERR, "recvfrom: %m");
		return;
	}
	if (tracepackets > 1 && ftrace) {
	    fprintf(ftrace,"rcv %d bytes on %s ", cc, xns_ntoa(&idp->idp_dna));
	    fprintf(ftrace," from %s\n", xns_ntoa(&idp->idp_sna));
	}
	
	if (noteremoterequests && !ns_neteqnn(idp->idp_sna.x_net, ns_zeronet)
		&& !ns_neteq(idp->idp_sna, idp->idp_dna))
	{
		syslog(LOG_ERR,
		       "net of interface (%s) != net on ether (%s)!\n",
		       xns_nettoa(idp->idp_dna.x_net),
		       xns_nettoa(idp->idp_sna.x_net));
	}
			
	/* We get the IDP header in front of the RIF packet*/
	cc -= sizeof (struct idp);
#define	mask(s)	(1<<((s)-1))
	omask = sigblock(mask(SIGALRM));
	rip_input(&from, cc);
	sigsetmask(omask);
}

getsocket(type, proto, sns)
	int type, proto; 
	struct sockaddr_ns *sns;
{
	int domain = sns->sns_family;
	int retry, s, on = 1;

	retry = 1;
	while ((s = socket(domain, type, proto)) < 0 && retry) {
		syslog(LOG_ERR, "socket: %m");
		sleep(5 * retry);
		retry <<= 1;
	}
	if (retry == 0)
		return (-1);
	while (bind(s, (struct sockaddr *)sns, sizeof (*sns)) < 0 && retry) {
		syslog(LOG_ERR, "bind: %m");
		sleep(5 * retry);
		retry <<= 1;
	}
	if (retry == 0)
		return (-1);
	if (domain==AF_NS) {
		struct idp idp;
		if (setsockopt(s, 0, SO_HEADERS_ON_INPUT, &on, sizeof(on))) {
			syslog(LOG_ERR, "setsockopt SEE HEADERS: %m");
			exit(1);
		}
		idp.idp_pt = NSPROTO_RI;
		if (setsockopt(s, 0, SO_DEFAULT_HEADERS, &idp, sizeof(idp))) {
			syslog(LOG_ERR, "setsockopt SET HEADER: %m");
			exit(1);
		}
	}
	if (setsockopt(s, SOL_SOCKET, SO_BROADCAST, &on, sizeof (on)) < 0) {
		syslog(LOG_ERR, "setsockopt SO_BROADCAST: %m");
		exit(1);
	}
	return (s);
}

/*
 * Fork and exit on EMT-- for profiling.
 */
void
fkexit()
{
	if (fork() == 0)
		exit(0);
}