ping.c

早期freebsd实现

/*
 * 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 */

/*
 *			P I N G . C
 *
 * 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/file.h>
#include <sys/time.h>
#include <sys/signal.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 <netdb.h>
#include <unistd.h>
#include <stdio.h>
#include <ctype.h>
#include <errno.h>
#include <string.h>

#define	DEFDATALEN	(64 - 8)	/* default data length */
#define	MAXIPLEN	60
#define	MAXICMPLEN	76
#define	MAXPACKET	(65536 - 60 - 8)/* max packet size */
#define	MAXWAIT		10		/* max seconds to wait for response */
#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))

/* various options */
int options;
#define	F_FLOOD		0x001
#define	F_INTERVAL	0x002
#define	F_NUMERIC	0x004
#define	F_PINGFILLED	0x008
#define	F_QUIET		0x010
#define	F_RROUTE	0x020
#define	F_SO_DEBUG	0x040
#define	F_SO_DONTROUTE	0x080
#define	F_VERBOSE	0x100

/*
 * 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 * 128)
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 */

char *pr_addr();
void catcher(), finish();

main(argc, argv)
	int argc;
	char **argv;
{
	extern int errno, optind;
	extern char *optarg;
	struct timeval timeout;
	struct hostent *hp;
	struct sockaddr_in *to;
	struct protoent *proto;
	register int i;
	int ch, fdmask, hold, packlen, preload;
	u_char *datap, *packet;
	char *target, hnamebuf[MAXHOSTNAMELEN], *malloc();
#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, "Rc:dfh:i:l:np:qrs:v")) != EOF)
		switch(ch) {
		case 'c':
			npackets = atoi(optarg);
			if (npackets <= 0) {
				(void)fprintf(stderr,
				    "ping: bad number of packets to transmit.\n");
				exit(1);
			}
			break;
		case 'd':
			options |= F_SO_DEBUG;
			break;
		case 'f':
			if (getuid()) {
				(void)fprintf(stderr,
				    "ping: %s\n", strerror(EPERM));
				exit(1);
			}
			options |= F_FLOOD;
			setbuf(stdout, (char *)NULL);
			break;
		case 'i':		/* wait between sending packets */
			interval = atoi(optarg);
			if (interval <= 0) {
				(void)fprintf(stderr,
				    "ping: bad timing interval.\n");
				exit(1);
			}
			options |= F_INTERVAL;
			break;
		case 'l':
			preload = atoi(optarg);
			if (preload < 0) {
				(void)fprintf(stderr,
				    "ping: bad preload value.\n");
				exit(1);
			}
			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 = atoi(optarg);
			if (datalen > MAXPACKET) {
				(void)fprintf(stderr,
				    "ping: packet size too large.\n");
				exit(1);
			}
			if (datalen <= 0) {
				(void)fprintf(stderr,
				    "ping: illegal packet size.\n");
				exit(1);
			}
			break;
		case 'v':
			options |= F_VERBOSE;
			break;
		default:
			usage();
		}
	argc -= optind;
	argv += optind;

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

	bzero((char *)&whereto, 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) {
			(void)fprintf(stderr,
			    "ping: unknown host %s\n", target);
			exit(1);
		}
		to->sin_family = hp->h_addrtype;
		bcopy(hp->h_addr, (caddr_t)&to->sin_addr, hp->h_length);
		(void)strncpy(hnamebuf, hp->h_name, sizeof(hnamebuf) - 1);
		hostname = hnamebuf;
	}

	if (options & F_FLOOD && options & F_INTERVAL) {
		(void)fprintf(stderr,
		    "ping: -f and -i incompatible options.\n");
		exit(1);
	}

	if (datalen >= sizeof(struct timeval))	/* can we time transfer */
		timing = 1;
	packlen = datalen + MAXIPLEN + MAXICMPLEN;
	if (!(packet = (u_char *)malloc((u_int)packlen))) {
		(void)fprintf(stderr, "ping: out of memory.\n");
		exit(1);
	}
	if (!(options & F_PINGFILLED))
		for (i = 8; i < datalen; ++i)
			*datap++ = i;

	ident = getpid() & 0xFFFF;

	if (!(proto = getprotobyname("icmp"))) {
		(void)fprintf(stderr, "ping: unknown protocol icmp.\n");
		exit(1);
	}
	if ((s = socket(AF_INET, SOCK_RAW, proto->p_proto)) < 0) {
		perror("ping: socket");
		exit(1);
	}
	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) {
			perror("ping: record route");
			exit(1);
		}
#else
		(void)fprintf(stderr,
		  "ping: record route not available in this implementation.\n");
		exit(1);
#endif /* IP_OPTIONS */
	}

	/*
	 * 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);

	(void)signal(SIGINT, finish);
	(void)signal(SIGALRM, catcher);

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

	if ((options & F_FLOOD) == 0)
		catcher();		/* start things going */

	for (;;) {
		struct sockaddr_in from;
		register int cc;
		int fromlen;

		if (options & F_FLOOD) {
			pinger();
			timeout.tv_sec = 0;
			timeout.tv_usec = 10000;
			fdmask = 1 << s;
			if (select(s + 1, (fd_set *)&fdmask, (fd_set *)NULL,
			    (fd_set *)NULL, &timeout) < 1)
				continue;
		}
		fromlen = sizeof(from);
		if ((cc = recvfrom(s, (char *)packet, packlen, 0,
		    (struct sockaddr *)&from, &fromlen)) < 0) {
			if (errno == EINTR)
				continue;
			perror("ping: recvfrom");
			continue;
		}
		pr_pack((char *)packet, cc, &from);
		if (npackets && nreceived >= npackets)
			break;
	}
	finish();
	/* NOTREACHED */
}

/*
 * catcher --
 *	This routine causes another PING to be transmitted, and then
 * schedules another SIGALRM for 1 second from now.
 *
 * bug --
 *	Our sense of time will slowly skew (i.e., packets will not be
 * launched exactly at 1-second intervals).  This does not affect the
 * quality of the delay and loss statistics.
 */
void
catcher()
{
	int waittime;

	pinger();
	(void)signal(SIGALRM, catcher);
	if (!npackets || ntransmitted < npackets)
		alarm((u_int)interval);
	else {
		if (nreceived) {
			waittime = 2 * tmax / 1000;
			if (!waittime)
				waittime = 1;
		} else
			waittime = MAXWAIT;
		(void)signal(SIGALRM, finish);
		(void)alarm((u_int)waittime);
	}
}

/*
 * 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.
 */
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],
		    (struct timezone *)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)
			perror("ping: 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!).
 */
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, (struct timezone *)NULL);

	/* Check the IP header */
	ip = (struct ip *)buf;
	hlen = ip->ip_hl << 2;
	if (cc < hlen + ICMP_MINLEN) {
		if (options & F_VERBOSE)
			(void)fprintf(stderr,
			  "ping: 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;