cmds.c

早期freebsd实现

/*-
 * Copyright (c) 1985, 1993
 *	The Regents of the University of California.  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. 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 sccsid[] = "@(#)cmds.c	8.1 (Berkeley) 6/6/93";
#endif /* not lint */

#ifdef sgi
#ident "$Revision: 1.10 $"
#endif

#include "timedc.h"
#include <sys/file.h>

#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>

#include <stdlib.h>
#include <strings.h>
#include <unistd.h>

#define TSPTYPES
#include <protocols/timed.h>

#ifdef sgi
#include <bstring.h>
#include <sys/clock.h>
#else
#define	SECHR	(60*60)
#define	SECDAY	(24*SECHR)
#endif /* sgi */

# define DATE_PROTO "udp"
# define DATE_PORT "time"


int sock;
int sock_raw;
char myname[MAXHOSTNAMELEN];
struct hostent *hp;
struct sockaddr_in server;
struct sockaddr_in dayaddr;
extern int measure_delta;

void bytenetorder(struct tsp *);
void bytehostorder(struct tsp *);


#define BU ((unsigned long)2208988800)	/* seconds before UNIX epoch */


/* compute the difference between our date and another machine
 */
static int				/* difference in days from our time */
daydiff(hostname)
	char *hostname;
{
	int i;
	int trials;
	struct timeval tout, now;
	fd_set ready;
	struct sockaddr from;
	int fromlen;
	unsigned long sec;


	/* wait 2 seconds between 10 tries */
	tout.tv_sec = 2;
	tout.tv_usec = 0;
	for (trials = 0; trials < 10; trials++) {
		/* ask for the time */
		sec = 0;
		if (sendto(sock, &sec, sizeof(sec), 0,
			   (struct sockaddr*)&dayaddr, sizeof(dayaddr)) < 0) {
			perror("sendto(sock)");
			return 0;
		}

		for (;;) {
			FD_ZERO(&ready);
			FD_SET(sock, &ready);
			i = select(sock+1, &ready, (fd_set *)0,
				   (fd_set *)0, &tout);
			if (i < 0) {
				if (errno = EINTR)
					continue;
				perror("select(date read)");
				return 0;
			}
			if (0 == i)
				break;

			fromlen = sizeof(from);
			if (recvfrom(sock,&sec,sizeof(sec),0,
				     &from,&fromlen) < 0) {
				perror("recvfrom(date read)");
				return 0;
			}

			sec = ntohl(sec);
			if (sec < BU) {
				fprintf(stderr,
					"%s says it is before 1970: %lu",
					hostname, sec);
				return 0;
			}
			sec -= BU;

			(void)gettimeofday(&now, (struct timezone*)0);
			return (sec - now.tv_sec);
		}
	}

	/* if we get here, we tried too many times */
	fprintf(stderr,"%s will not tell us the date\n", hostname);
	return 0;
}


/*
 * Clockdiff computes the difference between the time of the machine on
 * which it is called and the time of the machines given as argument.
 * The time differences measured by clockdiff are obtained using a sequence
 * of ICMP TSTAMP messages which are returned to the sender by the IP module
 * in the remote machine.
 * In order to compare clocks of machines in different time zones, the time
 * is transmitted (as a 32-bit value) in milliseconds since midnight UT.
 * If a hosts uses a different time format, it should set the high order
 * bit of the 32-bit quantity it transmits.
 * However, VMS apparently transmits the time in milliseconds since midnight
 * local time (rather than GMT) without setting the high order bit.
 * Furthermore, it does not understand daylight-saving time.  This makes
 * clockdiff behaving inconsistently with hosts running VMS.
 *
 * In order to reduce the sensitivity to the variance of message transmission
 * time, clockdiff sends a sequence of messages.  Yet, measures between
 * two `distant' hosts can be affected by a small error. The error can,
 * however, be reduced by increasing the number of messages sent in each
 * measurement.
 */
void
clockdiff(argc, argv)
	int argc;
	char *argv[];
{
	int measure_status;
	extern int measure(u_long, u_long, char *, struct sockaddr_in*, int);
	register int avg_cnt;
	register long avg;
	struct servent *sp;

	if (argc < 2)  {
		printf("Usage: clockdiff host ... \n");
		return;
	}

	(void)gethostname(myname,sizeof(myname));

	/* get the address for the date ready */
	sp = getservbyname(DATE_PORT, DATE_PROTO);
	if (!sp) {
		(void)fprintf(stderr, "%s/%s is an unknown service\n",
			      DATE_PORT, DATE_PROTO);
		dayaddr.sin_port = 0;
	} else {
		dayaddr.sin_port = sp->s_port;
	}

	while (argc > 1) {
		argc--; argv++;
		hp = gethostbyname(*argv);
		if (hp == NULL) {
			fprintf(stderr, "timedc: %s: ", *argv);
			herror(0);
			continue;
		}

		server.sin_family = hp->h_addrtype;
		bcopy(hp->h_addr, &server.sin_addr.s_addr, hp->h_length);
		for (avg_cnt = 0, avg = 0; avg_cnt < 16; avg_cnt++) {
			measure_status = measure(10000,100, *argv, &server, 1);
			if (measure_status != GOOD)
				break;
			avg += measure_delta;
		}
		if (measure_status == GOOD)
			measure_delta = avg/avg_cnt;

		switch (measure_status) {
		case HOSTDOWN:
			printf("%s is down\n", hp->h_name);
			continue;
		case NONSTDTIME:
			printf("%s transmitts a non-standard time format\n",
			       hp->h_name);
			continue;
		case UNREACHABLE:
			printf("%s is unreachable\n", hp->h_name);
			continue;
		}

		/*
		 * Try to get the date only after using ICMP timestamps to
		 * get the time.  This is because the date protocol
		 * is optional.
		 */
		if (dayaddr.sin_port != 0) {
			dayaddr.sin_family = hp->h_addrtype;
			bcopy(hp->h_addr, &dayaddr.sin_addr.s_addr,
			      hp->h_length);
			avg = daydiff(*argv);
			if (avg > SECDAY) {
				printf("time on %s is %ld days ahead %s\n",
				       hp->h_name, avg/SECDAY, myname);
				continue;
			} else if (avg < -SECDAY) {
				printf("time on %s is %ld days behind %s\n",
				       hp->h_name, -avg/SECDAY, myname);
				continue;
			}
		}

		if (measure_delta > 0) {
			printf("time on %s is %d ms. ahead of time on %s\n",
			       hp->h_name, measure_delta, myname);
		} else if (measure_delta == 0) {
			printf("%s and %s have the same time\n",
			       hp->h_name, myname);
		} else {
			printf("time on %s is %d ms. behind time on %s\n",
			       hp->h_name, -measure_delta, myname);
		}
	}
	return;
}


/*
 * finds location of master timedaemon
 */
void
msite(argc, argv)
	int argc;
	char *argv[];
{
	int cc;
	fd_set ready;
	struct sockaddr_in dest;
	int i, length;
	struct sockaddr from;
	struct timeval tout;
	struct tsp msg;
	struct servent *srvp;
	char *tgtname;

	if (argc < 1) {
		printf("Usage: msite [hostname]\n");
		return;
	}

	srvp = getservbyname("timed", "udp");
	if (srvp == 0) {
		fprintf(stderr, "udp/timed: unknown service\n");
		return;
	}
	dest.sin_port = srvp->s_port;
	dest.sin_family = AF_INET;

	(void)gethostname(myname, sizeof(myname));
	i = 1;
	do {
		tgtname = (i >= argc) ? myname : argv[i];
		hp = gethostbyname(tgtname);
		if (hp == 0) {
			fprintf(stderr, "timedc: %s: ", tgtname);
			herror(0);
			continue;
		}
		bcopy(hp->h_addr, &dest.sin_addr.s_addr, hp->h_length);

		(void)strcpy(msg.tsp_name, myname);
		msg.tsp_type = TSP_MSITE;
		msg.tsp_vers = TSPVERSION;
		bytenetorder(&msg);
		if (sendto(sock, &msg, sizeof(struct tsp), 0,
			   (struct sockaddr*)&dest,
			   sizeof(struct sockaddr)) < 0) {
			perror("sendto");
			continue;
		}

		tout.tv_sec = 15;
		tout.tv_usec = 0;
		FD_ZERO(&ready);
		FD_SET(sock, &ready);
		if (select(FD_SETSIZE, &ready, (fd_set *)0, (fd_set *)0,
			   &tout)) {
			length = sizeof(struct sockaddr);
			cc = recvfrom(sock, &msg, sizeof(struct tsp), 0,
				      &from, &length);
			if (cc < 0) {
				perror("recvfrom");
				continue;
			}
			bytehostorder(&msg);
			if (msg.tsp_type == TSP_ACK) {
				printf("master timedaemon at %s is %s\n",
				       tgtname, msg.tsp_name);
			} else {
				printf("received wrong ack: %s\n",
				       tsptype[msg.tsp_type]);
			}
		} else {
			printf("communication error with %s\n", tgtname);
		}
	} while (++i < argc);
}

/*
 * quits timedc
 */
void
quit()
{
	exit(0);
}


/*
 * Causes the election timer to expire on the selected hosts
 * It sends just one udp message per machine, relying on
 * reliability of communication channel.
 */
void
testing(argc, argv)
	int argc;
	char *argv[];
{
	struct servent *srvp;
	struct sockaddr_in sin;
	struct tsp msg;

	if (argc < 2)  {
		printf("Usage: election host1 [host2 ...]\n");
		return;
	}

	srvp = getservbyname("timed", "udp");
	if (srvp == 0) {
		fprintf(stderr, "udp/timed: unknown service\n");
		return;
	}

	while (argc > 1) {
		argc--; argv++;
		hp = gethostbyname(*argv);
		if (hp == NULL) {
			fprintf(stderr, "timedc: %s: ", *argv);
			herror(0);
			argc--; argv++;
			continue;
		}
		sin.sin_port = srvp->s_port;
		sin.sin_family = hp->h_addrtype;
		bcopy(hp->h_addr, &sin.sin_addr.s_addr, hp->h_length);

		msg.tsp_type = TSP_TEST;
		msg.tsp_vers = TSPVERSION;
		(void)gethostname(myname, sizeof(myname));
		(void)strncpy(msg.tsp_name, myname, sizeof(msg.tsp_name));
		bytenetorder(&msg);
		if (sendto(sock, &msg, sizeof(struct tsp), 0,
			   (struct sockaddr*)&sin,
			   sizeof(struct sockaddr)) < 0) {
			perror("sendto");
		}
	}
}


/*
 * Enables or disables tracing on local timedaemon
 */
void
tracing(argc, argv)
	int argc;
	char *argv[];
{
	int onflag;
	int length;
	int cc;
	fd_set ready;
	struct sockaddr_in dest;
	struct sockaddr from;
	struct timeval tout;
	struct tsp msg;
	struct servent *srvp;

	if (argc != 2) {
		printf("Usage: tracing { on | off }\n");
		return;
	}

	srvp = getservbyname("timed", "udp");
	if (srvp == 0) {
		fprintf(stderr, "udp/timed: unknown service\n");
		return;
	}
	dest.sin_port = srvp->s_port;
	dest.sin_family = AF_INET;

	(void)gethostname(myname,sizeof(myname));
	hp = gethostbyname(myname);
	bcopy(hp->h_addr, &dest.sin_addr.s_addr, hp->h_length);

	if (strcmp(argv[1], "on") == 0) {
		msg.tsp_type = TSP_TRACEON;
		onflag = ON;
	} else {
		msg.tsp_type = TSP_TRACEOFF;
		onflag = OFF;
	}

	(void)strcpy(msg.tsp_name, myname);
	msg.tsp_vers = TSPVERSION;
	bytenetorder(&msg);
	if (sendto(sock, &msg, sizeof(struct tsp), 0,
		   (struct sockaddr*)&dest, sizeof(struct sockaddr)) < 0) {
		perror("sendto");
		return;
	}

	tout.tv_sec = 5;
	tout.tv_usec = 0;
	FD_ZERO(&ready);
	FD_SET(sock, &ready);
	if (select(FD_SETSIZE, &ready, (fd_set *)0, (fd_set *)0, &tout)) {
		length = sizeof(struct sockaddr);
		cc = recvfrom(sock, &msg, sizeof(struct tsp), 0,
			      &from, &length);
		if (cc < 0) {
			perror("recvfrom");
			return;
		}
		bytehostorder(&msg);
		if (msg.tsp_type == TSP_ACK)
			if (onflag)
				printf("timed tracing enabled\n");
			else
				printf("timed tracing disabled\n");
		else
			printf("wrong ack received: %s\n",
						tsptype[msg.tsp_type]);
	} else
		printf("communication error\n");
}

int
priv_resources()
{
	int port;
	struct sockaddr_in sin;

	sock = socket(AF_INET, SOCK_DGRAM, 0);
	if (sock < 0) {
		perror("opening socket");
		return(-1);
	}

	sin.sin_family = AF_INET;
	sin.sin_addr.s_addr = 0;
	for (port = IPPORT_RESERVED - 1; port > IPPORT_RESERVED / 2; port--) {
		sin.sin_port = htons((u_short)port);
		if (bind(sock, (struct sockaddr*)&sin, sizeof (sin)) >= 0)
			break;
		if (errno != EADDRINUSE && errno != EADDRNOTAVAIL) {
			perror("bind");
			(void) close(sock);
			return(-1);
		}
	}
	if (port == IPPORT_RESERVED / 2) {
		fprintf(stderr, "all reserved ports in use\n");
		(void) close(sock);
		return(-1);
	}

	sock_raw = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
	if (sock_raw < 0)  {
		perror("opening raw socket");
		(void) close(sock);
		return(-1);
	}
	return(1);
}