bsdping.c

unix网络编程第一卷socket编程书上的全部源代码

/*	BSDI	ping.c,v 2.3 1996/01/21 17:56:50 jch Exp	*/

/*
 * Copyright (c) 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Mike Muuss.
 *
 * 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) 1989, 1993\n\
	The Regents of the University of California.  All rights reserved.\n";
#endif /* not lint */

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

/*
 * Using the InterNet Control Message Protocol (ICMP) "ECHO" facility,
 * measure round-trip-delays and packet loss across network paths.
 *
 * Author -
 *	Mike Muuss
 *	U. S. Army Ballistic Research Laboratory
 *	December, 1983
 *
 * Status -
 *	Public Domain.  Distribution Unlimited.
 * Bugs -
 *	More statistics could always be gathered.
 *	This program has to run SUID to ROOT to access the ICMP socket.
 */

#include <sys/param.h>
#include <sys/socket.h>
#include <sys/time.h>

#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#include <netinet/ip_var.h>
#include <arpa/inet.h>
#include <netdb.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#define	DEFDATALEN	(64 - 8)	/* default data length */
#define	MAXIPLEN	60
#define	MAXICMPLEN	76
#define	MAXPACKET	(65536 - 60 - 8)/* max packet size */
#define	NROUTES		9		/* number of record route slots */

#define	A(bit)		rcvd_tbl[(bit)>>3]	/* identify byte in array */
#define	B(bit)		(1 << ((bit) & 0x07))	/* identify bit in byte */
#define	SET(bit)	(A(bit) |= B(bit))
#define	CLR(bit)	(A(bit) &= (~B(bit)))
#define	TST(bit)	(A(bit) & B(bit))

#define	F_FLOOD		0x0001
#define	F_INTERVAL	0x0002
#define	F_NUMERIC	0x0004
#define	F_PINGFILLED	0x0008
#define	F_QUIET		0x0010
#define	F_RROUTE	0x0020
#define	F_SO_DEBUG	0x0040
#define	F_SO_DONTROUTE	0x0080
#define	F_VERBOSE	0x0100
u_int options;

/*
 * MAX_DUP_CHK is the number of bits in received table, i.e. the maximum
 * number of received sequence numbers we can keep track of.  Change 128
 * to 8192 for complete accuracy...
 */
#define	MAX_DUP_CHK	(8 * 8192)
int mx_dup_ck = MAX_DUP_CHK;
char rcvd_tbl[MAX_DUP_CHK / 8];

struct sockaddr whereto;	/* who to ping */
int datalen = DEFDATALEN;
int s;				/* socket file descriptor */
u_char outpack[MAXPACKET];
char BSPACE = '\b';		/* characters written for flood */
char DOT = '.';
char *hostname;
int ident;			/* process id to identify our packets */

/* counters */
long npackets;			/* max packets to transmit */
long nreceived;			/* # of packets we got back */
long nrepeats;			/* number of duplicates */
long ntransmitted;		/* sequence # for outbound packets = #sent */
int interval = 1;		/* interval between packets */

/* timing */
int timing;			/* flag to do timing */
double tmin = 999999999.0;	/* minimum round trip time */
double tmax = 0.0;		/* maximum round trip time */
double tsum = 0.0;		/* sum of all times, for doing average */

void	 fill __P((char *, char *));
u_short	 in_cksum __P((u_short *, int));
void	 onalrm __P((int));
void	 oninfo __P((int));
void	 onint __P((int));
void	 pinger __P((void));
char	*pr_addr __P((u_long));
void	 pr_icmph __P((struct icmp *));
void	 pr_iph __P((struct ip *));
void	 pr_pack __P((char *, int, struct sockaddr_in *));
void	 pr_retip __P((struct ip *));
void	 summary __P((void));
void	 tvsub __P((struct timeval *, struct timeval *));
void	 usage __P((void));

int
main(argc, argv)
	int argc;
	char *argv[];
{
	extern int errno, optind;
	extern char *optarg;
	struct hostent *hp;
	struct itimerval itimer;
	struct protoent *proto;
	struct sockaddr_in *to, from;
	struct timeval timeout;
	fd_set fdset;
	register int cc, i;
	int ch, fromlen, hold, packlen, preload;
	u_char *datap, *packet;
	char *e, *target, hnamebuf[MAXHOSTNAMELEN];
#ifdef IP_OPTIONS
	char rspace[3 + 4 * NROUTES + 1];	/* record route space */
#endif

	preload = 0;
	datap = &outpack[8 + sizeof(struct timeval)];
	while ((ch = getopt(argc, argv, "c:dfi:l:np:qRrs:v")) != -1)
		switch(ch) {
		case 'c':
			npackets = strtol(optarg, &e, 10);
			if (npackets <= 0 || *optarg == '\0' || *e != '\0')
				errx(1,
				    "illegal number of packets -- %s", optarg);
			break;
		case 'd':
			options |= F_SO_DEBUG;
			break;
		case 'f':
			if (getuid()) {
				errno = EPERM;
				err(1, NULL);
			}
			options |= F_FLOOD;
			setbuf(stdout, (char *)NULL);
			break;
		case 'i':		/* wait between sending packets */
			interval = strtol(optarg, &e, 10);
			if (interval <= 0 || *optarg == '\0' || *e != '\0')
				errx(1,
				    "illegal timing interval -- %s", optarg);
			options |= F_INTERVAL;
			break;
		case 'l':
			preload = strtol(optarg, &e, 10);
			if (preload < 0 || *optarg == '\0' || *e != '\0')
				errx(1, "illegal preload value -- %s", optarg);
			break;
		case 'n':
			options |= F_NUMERIC;
			break;
		case 'p':		/* fill buffer with user pattern */
			options |= F_PINGFILLED;
			fill((char *)datap, optarg);
				break;
		case 'q':
			options |= F_QUIET;
			break;
		case 'R':
			options |= F_RROUTE;
			break;
		case 'r':
			options |= F_SO_DONTROUTE;
			break;
		case 's':		/* size of packet to send */
			datalen = strtol(optarg, &e, 10);
			if (datalen <= 0 || *optarg == '\0' || *e != '\0')
				errx(1, "illegal datalen value -- %s", optarg);
			if (datalen > MAXPACKET)
				errx(1,
				    "datalen value too large, maximum is %d",
				    MAXPACKET);
			break;
		case 'v':
			options |= F_VERBOSE;
			break;
		default:
			usage();
		}
	argc -= optind;
	argv += optind;

	if (argc != 1)
		usage();
	target = *argv;

	memset(&whereto, 0, sizeof(struct sockaddr));
	to = (struct sockaddr_in *)&whereto;
	to->sin_family = AF_INET;
	to->sin_addr.s_addr = inet_addr(target);
	if (to->sin_addr.s_addr != (u_int)-1)
		hostname = target;
	else {
		hp = gethostbyname(target);
		if (!hp)
			errx(1, "unknown host %s", target);
		to->sin_family = hp->h_addrtype;
		memmove(&to->sin_addr, hp->h_addr, hp->h_length);
		(void)strncpy(hnamebuf, hp->h_name, sizeof(hnamebuf) - 1);
		hostname = hnamebuf;
	}

	if (options & F_FLOOD && options & F_INTERVAL)
		errx(1, "-f and -i incompatible options");

	if (datalen >= sizeof(struct timeval))	/* can we time transfer */
		timing = 1;
	packlen = datalen + MAXIPLEN + MAXICMPLEN;
	if (!(packet = (u_char *)malloc((u_int)packlen)))
		err(1, NULL);
	if (!(options & F_PINGFILLED))
		for (i = 8; i < datalen; ++i)
			*datap++ = i;

	ident = getpid() & 0xFFFF;

	if (!(proto = getprotobyname("icmp")))
		errx(1, "unknown protocol icmp");
	if ((s = socket(AF_INET, SOCK_RAW, proto->p_proto)) < 0)
		err(1, "socket");
	hold = 1;
	if (options & F_SO_DEBUG)
		(void)setsockopt(s, SOL_SOCKET, SO_DEBUG, (char *)&hold,
		    sizeof(hold));
	if (options & F_SO_DONTROUTE)
		(void)setsockopt(s, SOL_SOCKET, SO_DONTROUTE, (char *)&hold,
		    sizeof(hold));

	/* record route option */
	if (options & F_RROUTE) {
#ifdef IP_OPTIONS
		rspace[IPOPT_OPTVAL] = IPOPT_RR;
		rspace[IPOPT_OLEN] = sizeof(rspace)-1;
		rspace[IPOPT_OFFSET] = IPOPT_MINOFF;
		if (setsockopt(s, IPPROTO_IP, IP_OPTIONS, rspace,
		    sizeof(rspace)) < 0)
			err(1, "record route");
#else
		errx(1, "record route not available in this implementation");
#endif
	}

	/*
	 * When pinging the broadcast address, you can get a lot of answers.
	 * Doing something so evil is useful if you are trying to stress the
	 * ethernet, or just want to fill the arp cache to get some stuff for
	 * /etc/ethers.
	 */
	hold = 48 * 1024;
	(void)setsockopt(s,
	    SOL_SOCKET, SO_RCVBUF, (char *)&hold, sizeof(hold));

	if (to->sin_family == AF_INET)
		(void)printf("PING %s (%s): %d data bytes\n", hostname,
		    inet_ntoa(*(struct in_addr *)&to->sin_addr.s_addr),
		    datalen);
	else
		(void)printf("PING %s: %d data bytes\n", hostname, datalen);

	while (preload--)		/* Fire off them quickies. */
		pinger();

	(void)signal(SIGINT, onint);
	(void)signal(SIGINFO, oninfo);

	if ((options & F_FLOOD) == 0) {
		(void)signal(SIGALRM, onalrm);
		itimer.it_interval.tv_sec = interval;
		itimer.it_interval.tv_usec = 0;
		itimer.it_value.tv_sec = 0;
		itimer.it_value.tv_usec = 1;
		(void)setitimer(ITIMER_REAL, &itimer, NULL);
	}

	FD_ZERO(&fdset);
	timeout.tv_sec = 0;
	timeout.tv_usec = 10000;
	for (;;) {
		if (options & F_FLOOD) {
			pinger();
			FD_SET(s, &fdset);
			if (select(s + 1, &fdset, NULL, NULL, &timeout) < 1)
				continue;
		}
		fromlen = sizeof(from);
		if ((cc = recvfrom(s, (char *)packet, packlen, 0,
		    (struct sockaddr *)&from, &fromlen)) < 0) {
			if (errno == EINTR)
				continue;
			warn("recvfrom");
			continue;
		}
		pr_pack((char *)packet, cc, &from);
		if (npackets && nreceived >= npackets)
			break;
	}
	summary();
	exit(nreceived == 0);
}

/*
 * onalrm --
 *	This routine transmits another ping.
 */
void
onalrm(signo)
	int signo;
{
	struct itimerval itimer;

	if (!npackets || ntransmitted < npackets) {
		pinger();
		return;
	}

	/*
	 * If we're not transmitting any more packets, change the timer
	 * to wait two round-trip times if we've received any packets or
	 * ten seconds if we haven't.
	 */
#define	MAXWAIT		10
	if (nreceived) {
		itimer.it_value.tv_sec =  2 * tmax / 1000;
		if (itimer.it_value.tv_sec == 0)
			itimer.it_value.tv_sec = 1;
	} else
		itimer.it_value.tv_sec = MAXWAIT;
	itimer.it_interval.tv_sec = 0;
	itimer.it_interval.tv_usec = 0;
	itimer.it_value.tv_usec = 0;

	(void)signal(SIGALRM, onint);
	(void)setitimer(ITIMER_REAL, &itimer, NULL);
}

/*
 * pinger --
 *	Compose and transmit an ICMP ECHO REQUEST packet.  The IP packet
 * will be added on by the kernel.  The ID field is our UNIX process ID,
 * and the sequence number is an ascending integer.  The first 8 bytes
 * of the data portion are used to hold a UNIX "timeval" struct in VAX
 * byte-order, to compute the round-trip time.
 */
void
pinger()
{
	register struct icmp *icp;
	register int cc;
	int i;

	icp = (struct icmp *)outpack;
	icp->icmp_type = ICMP_ECHO;
	icp->icmp_code = 0;
	icp->icmp_cksum = 0;
	icp->icmp_seq = ntransmitted++;
	icp->icmp_id = ident;			/* ID */

	CLR(icp->icmp_seq % mx_dup_ck);

	if (timing)
		(void)gettimeofday((struct timeval *)&outpack[8], NULL);

	cc = datalen + 8;			/* skips ICMP portion */

	/* compute ICMP checksum here */
	icp->icmp_cksum = in_cksum((u_short *)icp, cc);

	i = sendto(s, (char *)outpack, cc, 0, &whereto,
	    sizeof(struct sockaddr));

	if (i < 0 || i != cc)  {
		if (i < 0)
			warn("sendto");
		(void)printf("ping: wrote %s %d chars, ret=%d\n",
		    hostname, cc, i);
	}
	if (!(options & F_QUIET) && options & F_FLOOD)
		(void)write(STDOUT_FILENO, &DOT, 1);
}

/*
 * pr_pack --
 *	Print out the packet, if it came from us.  This logic is necessary
 * because ALL readers of the ICMP socket get a copy of ALL ICMP packets
 * which arrive ('tis only fair).  This permits multiple copies of this
 * program to be run without having intermingled output (or statistics!).
 */
void
pr_pack(buf, cc, from)
	char *buf;
	int cc;
	struct sockaddr_in *from;
{
	register struct icmp *icp;
	register u_long l;
	register int i, j;
	register u_char *cp,*dp;
	static int old_rrlen;
	static char old_rr[MAX_IPOPTLEN];
	struct ip *ip;
	struct timeval tv, *tp;
	double triptime;
	int hlen, dupflag;

	(void)gettimeofday(&tv, NULL);

	/* Check the IP header */
	ip = (struct ip *)buf;
	hlen = ip->ip_hl << 2;
	if (cc < hlen + ICMP_MINLEN) {
		if (options & F_VERBOSE)
			warnx("packet too short (%d bytes) from %s\n", cc,
			  inet_ntoa(*(struct in_addr *)&from->sin_addr.s_addr));
		return;
	}

	/* Now the ICMP part */
	cc -= hlen;
	icp = (struct icmp *)(buf + hlen);
	if (icp->icmp_type == ICMP_ECHOREPLY) {
		if (icp->icmp_id != ident)
			return;			/* 'Twas not our ECHO */
		++nreceived;
		if (timing) {
#ifndef icmp_data
			tp = (struct timeval *)&icp->icmp_ip;
#else
			tp = (struct timeval *)icp->icmp_data;
#endif
			tvsub(&tv, tp);
			triptime = ((double)tv.tv_sec) * 1000.0 +
			    ((double)tv.tv_usec) / 1000.0;
			tsum += triptime;
			if (triptime < tmin)
				tmin = triptime;
			if (triptime > tmax)
				tmax = triptime;
		}

		if (TST(icp->icmp_seq % mx_dup_ck)) {
			++nrepeats;
			--nreceived;
			dupflag = 1;
		} else {