networking/ping.c - fp2-dev/platform/external/busybox - Gitiles

 /* vi: set sw=4 ts=4: */
 /*
  * $Id: ping.c,v 1.56 2004/03/15 08:28:48 andersen Exp $
  * Mini ping implementation for busybox
  *
  * Copyright (C) 1999 by Randolph Chung <tausq@debian.org>
  *
  * Adapted from the ping in netkit-base 0.10:
  * Copyright (c) 1989 The Regents of the University of California.
  * Derived from software contributed to Berkeley by Mike Muuss.
  *
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */

 #include <sys/param.h>
 #include <sys/socket.h>
 #include <sys/file.h>
 #include <sys/times.h>
 #include <signal.h>

 #include <netinet/in.h>
 #include <netinet/ip.h>
 #include <netinet/ip_icmp.h>
 #include <arpa/inet.h>
 #include <netdb.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <errno.h>
 #include <unistd.h>
 #include <string.h>
 #include <stdlib.h>
 #include "busybox.h"

 enum {
 	DEFDATALEN = 56,
 	MAXIPLEN = 60,
 	MAXICMPLEN = 76,
 	MAXPACKET = 65468,
 	MAX_DUP_CHK = (8 * 128),
 	MAXWAIT = 10,
 	PINGINTERVAL = 1		/* second */
 };

 #define O_QUIET         (1 << 0)

 #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))

 static void ping(const char *host);

 /* common routines */
 static int in_cksum(unsigned short *buf, int sz)
 {
 	int nleft = sz;
 	int sum = 0;
 	unsigned short *w = buf;
 	unsigned short ans = 0;

 	while (nleft > 1) {
 		sum += *w++;
 		nleft -= 2;
 	}

 	if (nleft == 1) {
 		*(unsigned char *) (&ans) = *(unsigned char *) w;
 		sum += ans;
 	}

 	sum = (sum >> 16) + (sum & 0xFFFF);
 	sum += (sum >> 16);
 	ans = ~sum;
 	return (ans);
 }

 /* simple version */
 #ifndef CONFIG_FEATURE_FANCY_PING
 static char *hostname;

 static void noresp(int ign)
 {
 	printf("No response from %s\n", hostname);
 	exit(EXIT_FAILURE);
 }

 static void ping(const char *host)
 {
 	struct hostent *h;
 	struct sockaddr_in pingaddr;
 	struct icmp *pkt;
 	int pingsock, c;
 	char packet[DEFDATALEN + MAXIPLEN + MAXICMPLEN];

 	pingsock = create_icmp_socket();

 	memset(&pingaddr, 0, sizeof(struct sockaddr_in));

 	pingaddr.sin_family = AF_INET;
 	h = xgethostbyname(host);
 	memcpy(&pingaddr.sin_addr, h->h_addr, sizeof(pingaddr.sin_addr));
 	hostname = h->h_name;

 	pkt = (struct icmp *) packet;
 	memset(pkt, 0, sizeof(packet));
 	pkt->icmp_type = ICMP_ECHO;
 	pkt->icmp_cksum = in_cksum((unsigned short *) pkt, sizeof(packet));

 	c = sendto(pingsock, packet, DEFDATALEN + ICMP_MINLEN, 0,
 			   (struct sockaddr *) &pingaddr, sizeof(struct sockaddr_in));

 	if (c < 0) {
 		if (ENABLE_FEATURE_CLEAN_UP) close(pingsock);
 		bb_perror_msg_and_die("sendto");
 	}

 	signal(SIGALRM, noresp);
 	alarm(5);					/* give the host 5000ms to respond */
 	/* listen for replies */
 	while (1) {
 		struct sockaddr_in from;
 		socklen_t fromlen = sizeof(from);

 		if ((c = recvfrom(pingsock, packet, sizeof(packet), 0,
 						  (struct sockaddr *) &from, &fromlen)) < 0) {
 			if (errno == EINTR)
 				continue;
 			bb_perror_msg("recvfrom");
 			continue;
 		}
 		if (c >= 76) {			/* ip + icmp */
 			struct iphdr *iphdr = (struct iphdr *) packet;

 			pkt = (struct icmp *) (packet + (iphdr->ihl << 2));	/* skip ip hdr */
 			if (pkt->icmp_type == ICMP_ECHOREPLY)
 				break;
 		}
 	}
 	if (ENABLE_FEATURE_CLEAN_UP) close(pingsock);
 	printf("%s is alive!\n", hostname);
 	return;
 }

 int ping_main(int argc, char **argv)
 {
 	argc--;
 	argv++;
 	if (argc < 1)
 		bb_show_usage();
 	ping(*argv);
 	return EXIT_SUCCESS;
 }

 #else /* ! CONFIG_FEATURE_FANCY_PING */
 /* full(er) version */
 static struct sockaddr_in pingaddr;
 static struct sockaddr_in sourceaddr;
 static int pingsock = -1;
 static int datalen; /* intentionally uninitialized to work around gcc bug */

 static long ntransmitted, nreceived, nrepeats, pingcount;
 static int myid, options;
 static unsigned long tmin = ULONG_MAX, tmax, tsum;
 static char rcvd_tbl[MAX_DUP_CHK / 8];

 static struct hostent *hostent;

 static void sendping(int);
 static void pingstats(int);
 static void unpack(char *, int, struct sockaddr_in *);

 /**************************************************************************/

 static void pingstats(int junk)
 {
 	int status;

 	signal(SIGINT, SIG_IGN);

 	printf("\n--- %s ping statistics ---\n", hostent->h_name);
 	printf("%ld packets transmitted, ", ntransmitted);
 	printf("%ld packets received, ", nreceived);
 	if (nrepeats)
 		printf("%ld duplicates, ", nrepeats);
 	if (ntransmitted)
 		printf("%ld%% packet loss\n",
 			   (ntransmitted - nreceived) * 100 / ntransmitted);
 	if (nreceived)
 		printf("round-trip min/avg/max = %lu.%lu/%lu.%lu/%lu.%lu ms\n",
 			   tmin / 10, tmin % 10,
 			   (tsum / (nreceived + nrepeats)) / 10,
 			   (tsum / (nreceived + nrepeats)) % 10, tmax / 10, tmax % 10);
 	if (nreceived != 0)
 		status = EXIT_SUCCESS;
 	else
 		status = EXIT_FAILURE;
 	exit(status);
 }

 static void sendping(int junk)
 {
 	struct icmp *pkt;
 	int i;
 	char packet[datalen + ICMP_MINLEN];

 	pkt = (struct icmp *) packet;

 	pkt->icmp_type = ICMP_ECHO;
 	pkt->icmp_code = 0;
 	pkt->icmp_cksum = 0;
 	pkt->icmp_seq = htons(ntransmitted++);
 	pkt->icmp_id = myid;
 	CLR(ntohs(pkt->icmp_seq) % MAX_DUP_CHK);

 	gettimeofday((struct timeval *) &pkt->icmp_dun, NULL);
 	pkt->icmp_cksum = in_cksum((unsigned short *) pkt, sizeof(packet));

 	i = sendto(pingsock, packet, sizeof(packet), 0,
 			   (struct sockaddr *) &pingaddr, sizeof(struct sockaddr_in));

 	if (i < 0)
 		bb_perror_msg_and_die("sendto");
 	else if ((size_t)i != sizeof(packet))
 		bb_error_msg_and_die("ping wrote %d chars; %d expected", i,
 			   (int)sizeof(packet));

 	signal(SIGALRM, sendping);
 	if (pingcount == 0 || ntransmitted < pingcount) {	/* schedule next in 1s */
 		alarm(PINGINTERVAL);
 	} else {					/* done, wait for the last ping to come back */
 		/* todo, don't necessarily need to wait so long... */
 		signal(SIGALRM, pingstats);
 		alarm(MAXWAIT);
 	}
 }

 static char *icmp_type_name(int id)
 {
 	switch (id) {
 	case ICMP_ECHOREPLY:		return "Echo Reply";
 	case ICMP_DEST_UNREACH:		return "Destination Unreachable";
 	case ICMP_SOURCE_QUENCH:	return "Source Quench";
 	case ICMP_REDIRECT:			return "Redirect (change route)";
 	case ICMP_ECHO:				return "Echo Request";
 	case ICMP_TIME_EXCEEDED:	return "Time Exceeded";
 	case ICMP_PARAMETERPROB:	return "Parameter Problem";
 	case ICMP_TIMESTAMP:		return "Timestamp Request";
 	case ICMP_TIMESTAMPREPLY:	return "Timestamp Reply";
 	case ICMP_INFO_REQUEST:		return "Information Request";
 	case ICMP_INFO_REPLY:		return "Information Reply";
 	case ICMP_ADDRESS:			return "Address Mask Request";
 	case ICMP_ADDRESSREPLY:		return "Address Mask Reply";
 	default:					return "unknown ICMP type";
 	}
 }

 static void unpack(char *buf, int sz, struct sockaddr_in *from)
 {
 	struct icmp *icmppkt;
 	struct iphdr *iphdr;
 	struct timeval tv, *tp;
 	int hlen, dupflag;
 	unsigned long triptime;

 	gettimeofday(&tv, NULL);

 	/* discard if too short */
 	if (sz < (datalen + ICMP_MINLEN))
 		return;

 	/* check IP header */
 	iphdr = (struct iphdr *) buf;
 	hlen = iphdr->ihl << 2;
 	sz -= hlen;
 	icmppkt = (struct icmp *) (buf + hlen);
 	if (icmppkt->icmp_id != myid)
 		return;				/* not our ping */

 	if (icmppkt->icmp_type == ICMP_ECHOREPLY) {
 		u_int16_t recv_seq = ntohs(icmppkt->icmp_seq);
 		++nreceived;
 		tp = (struct timeval *) icmppkt->icmp_data;

 		if ((tv.tv_usec -= tp->tv_usec) < 0) {
 			--tv.tv_sec;
 			tv.tv_usec += 1000000;
 		}
 		tv.tv_sec -= tp->tv_sec;

 		triptime = tv.tv_sec * 10000 + (tv.tv_usec / 100);
 		tsum += triptime;
 		if (triptime < tmin)
 			tmin = triptime;
 		if (triptime > tmax)
 			tmax = triptime;

 		if (TST(recv_seq % MAX_DUP_CHK)) {
 			++nrepeats;
 			--nreceived;
 			dupflag = 1;
 		} else {
 			SET(recv_seq % MAX_DUP_CHK);
 			dupflag = 0;
 		}

 		if (options & O_QUIET)
 			return;

 		printf("%d bytes from %s: icmp_seq=%u", sz,
 			   inet_ntoa(*(struct in_addr *) &from->sin_addr.s_addr),
 			   recv_seq);
 		printf(" ttl=%d", iphdr->ttl);
 		printf(" time=%lu.%lu ms", triptime / 10, triptime % 10);
 		if (dupflag)
 			printf(" (DUP!)");
 		printf("\n");
 	} else
 		if (icmppkt->icmp_type != ICMP_ECHO)
 			bb_error_msg("Warning: Got ICMP %d (%s)",
 					icmppkt->icmp_type, icmp_type_name(icmppkt->icmp_type));
 	fflush(stdout);
 }

 static void ping(const char *host)
 {
 	char packet[datalen + MAXIPLEN + MAXICMPLEN];
 	int sockopt;

 	pingsock = create_icmp_socket();

 	if (sourceaddr.sin_addr.s_addr) {
 		xbind(pingsock, (struct sockaddr*)&sourceaddr, sizeof(sourceaddr));
 	}

 	memset(&pingaddr, 0, sizeof(struct sockaddr_in));

 	pingaddr.sin_family = AF_INET;
 	hostent = xgethostbyname(host);
 	if (hostent->h_addrtype != AF_INET)
 		bb_error_msg_and_die("unknown address type; only AF_INET is currently supported");

 	memcpy(&pingaddr.sin_addr, hostent->h_addr, sizeof(pingaddr.sin_addr));

 	/* enable broadcast pings */
 	sockopt = 1;
 	setsockopt(pingsock, SOL_SOCKET, SO_BROADCAST, (char *) &sockopt,
 			   sizeof(sockopt));

 	/* set recv buf for broadcast pings */
 	sockopt = 48 * 1024;
 	setsockopt(pingsock, SOL_SOCKET, SO_RCVBUF, (char *) &sockopt,
 			   sizeof(sockopt));

 	printf("PING %s (%s)",
 			hostent->h_name,
 			inet_ntoa(*(struct in_addr *) &pingaddr.sin_addr.s_addr));
 	if (sourceaddr.sin_addr.s_addr) {
 		printf(" from %s",
 			inet_ntoa(*(struct in_addr *) &sourceaddr.sin_addr.s_addr));
 	}
 	printf(": %d data bytes\n", datalen);

 	signal(SIGINT, pingstats);

 	/* start the ping's going ... */
 	sendping(0);

 	/* listen for replies */
 	while (1) {
 		struct sockaddr_in from;
 		socklen_t fromlen = (socklen_t) sizeof(from);
 		int c;

 		if ((c = recvfrom(pingsock, packet, sizeof(packet), 0,
 						  (struct sockaddr *) &from, &fromlen)) < 0) {
 			if (errno == EINTR)
 				continue;
 			bb_perror_msg("recvfrom");
 			continue;
 		}
 		unpack(packet, c, &from);
 		if (pingcount > 0 && nreceived >= pingcount)
 			break;
 	}
 	pingstats(0);
 }

 /* TODO: consolidate ether-wake.c, dnsd.c, ifupdown.c, nslookup.c
  * versions of below thing. BTW we have far too many "%u.%u.%u.%u" too...
 */
 static int parse_nipquad(const char *str, struct sockaddr_in* addr)
 {
 	char dummy;
 	unsigned i1, i2, i3, i4;
 	if (sscanf(str, "%u.%u.%u.%u%c",
 			   &i1, &i2, &i3, &i4, &dummy) == 4
 	&& ( (i1|i2|i3|i4) <= 0xff )
 	) {
 		uint8_t* ptr = (uint8_t*)&addr->sin_addr;
 		ptr[0] = i1;
 		ptr[1] = i2;
 		ptr[2] = i3;
 		ptr[3] = i4;
 		return 0;
 	}
 	return 1; /* error */
 }

 int ping_main(int argc, char **argv)
 {
 	char *thisarg;

 	datalen = DEFDATALEN; /* initialized here rather than in global scope to work around gcc bug */

 	argc--;
 	argv++;
 	/* Parse any options */
 	while (argc >= 1 && **argv == '-') {
 		thisarg = *argv;
 		thisarg++;
 		switch (*thisarg) {
 		case 'q':
 			options |= O_QUIET;
 			break;
 		case 'c':
 			if (--argc <= 0)
 				bb_show_usage();
 			argv++;
 			pingcount = atoi(*argv);
 			break;
 		case 's':
 			if (--argc <= 0)
 				bb_show_usage();
 			argv++;
 			datalen = atoi(*argv);
 			break;
 		case 'I':
 			if (--argc <= 0)
 				bb_show_usage();
 			argv++;
 /* ping6 accepts iface too:
 			if_index = if_nametoindex(*argv);
 			if (!if_index) ...
    make it true for ping too. TODO.
 */
 			if (parse_nipquad(*argv, &sourceaddr))
 				bb_show_usage();
 			break;
 		default:
 			bb_show_usage();
 		}
 		argc--;
 		argv++;
 	}
 	if (argc < 1)
 		bb_show_usage();

 	myid = (int16_t) getpid();
 	ping(*argv);
 	return EXIT_SUCCESS;
 }
 #endif /* ! CONFIG_FEATURE_FANCY_PING */
	/* vi: set sw=4 ts=4: */
	/*
	* $Id: ping.c,v 1.56 2004/03/15 08:28:48 andersen Exp $
	* Mini ping implementation for busybox
	*
	* Copyright (C) 1999 by Randolph Chung <tausq@debian.org>
	*
	* Adapted from the ping in netkit-base 0.10:
	* Copyright (c) 1989 The Regents of the University of California.
	* Derived from software contributed to Berkeley by Mike Muuss.
	*
	* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
	*/

	#include <sys/param.h>
	#include <sys/socket.h>
	#include <sys/file.h>
	#include <sys/times.h>
	#include <signal.h>

	#include <netinet/in.h>
	#include <netinet/ip.h>
	#include <netinet/ip_icmp.h>
	#include <arpa/inet.h>
	#include <netdb.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <errno.h>
	#include <unistd.h>
	#include <string.h>
	#include <stdlib.h>
	#include "busybox.h"

	enum {
	DEFDATALEN = 56,
	MAXIPLEN = 60,
	MAXICMPLEN = 76,
	MAXPACKET = 65468,
	MAX_DUP_CHK = (8 * 128),
	MAXWAIT = 10,
	PINGINTERVAL = 1 /* second */
	};

	#define O_QUIET (1 << 0)

	#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))

	static void ping(const char *host);

	/* common routines */
	static int in_cksum(unsigned short *buf, int sz)
	{
	int nleft = sz;
	int sum = 0;
	unsigned short *w = buf;
	unsigned short ans = 0;

	while (nleft > 1) {
	sum += *w++;
	nleft -= 2;
	}

	if (nleft == 1) {
	(unsigned char ) (&ans) = (unsigned char ) w;
	sum += ans;
	}

	sum = (sum >> 16) + (sum & 0xFFFF);
	sum += (sum >> 16);
	ans = ~sum;
	return (ans);
	}

	/* simple version */
	#ifndef CONFIG_FEATURE_FANCY_PING
	static char *hostname;

	static void noresp(int ign)
	{
	printf("No response from %s\n", hostname);
	exit(EXIT_FAILURE);
	}

	static void ping(const char *host)
	{
	struct hostent *h;
	struct sockaddr_in pingaddr;
	struct icmp *pkt;
	int pingsock, c;
	char packet[DEFDATALEN + MAXIPLEN + MAXICMPLEN];

	pingsock = create_icmp_socket();

	memset(&pingaddr, 0, sizeof(struct sockaddr_in));

	pingaddr.sin_family = AF_INET;
	h = xgethostbyname(host);
	memcpy(&pingaddr.sin_addr, h->h_addr, sizeof(pingaddr.sin_addr));
	hostname = h->h_name;

	pkt = (struct icmp *) packet;
	memset(pkt, 0, sizeof(packet));
	pkt->icmp_type = ICMP_ECHO;
	pkt->icmp_cksum = in_cksum((unsigned short *) pkt, sizeof(packet));

	c = sendto(pingsock, packet, DEFDATALEN + ICMP_MINLEN, 0,
	(struct sockaddr *) &pingaddr, sizeof(struct sockaddr_in));

	if (c < 0) {
	if (ENABLE_FEATURE_CLEAN_UP) close(pingsock);
	bb_perror_msg_and_die("sendto");
	}

	signal(SIGALRM, noresp);
	alarm(5); /* give the host 5000ms to respond */
	/* listen for replies */
	while (1) {
	struct sockaddr_in from;
	socklen_t fromlen = sizeof(from);

	if ((c = recvfrom(pingsock, packet, sizeof(packet), 0,
	(struct sockaddr *) &from, &fromlen)) < 0) {
	if (errno == EINTR)
	continue;
	bb_perror_msg("recvfrom");
	continue;
	}
	if (c >= 76) { /* ip + icmp */
	struct iphdr iphdr = (struct iphdr ) packet;

	pkt = (struct icmp ) (packet + (iphdr->ihl << 2)); / skip ip hdr */
	if (pkt->icmp_type == ICMP_ECHOREPLY)
	break;
	}
	}
	if (ENABLE_FEATURE_CLEAN_UP) close(pingsock);
	printf("%s is alive!\n", hostname);
	return;
	}

	int ping_main(int argc, char **argv)
	{
	argc--;
	argv++;
	if (argc < 1)
	bb_show_usage();
	ping(*argv);
	return EXIT_SUCCESS;
	}

	#else /* ! CONFIG_FEATURE_FANCY_PING */
	/* full(er) version */
	static struct sockaddr_in pingaddr;
	static struct sockaddr_in sourceaddr;
	static int pingsock = -1;
	static int datalen; /* intentionally uninitialized to work around gcc bug */

	static long ntransmitted, nreceived, nrepeats, pingcount;
	static int myid, options;
	static unsigned long tmin = ULONG_MAX, tmax, tsum;
	static char rcvd_tbl[MAX_DUP_CHK / 8];

	static struct hostent *hostent;

	static void sendping(int);
	static void pingstats(int);
	static void unpack(char , int, struct sockaddr_in );

	/**************************************************************************/

	static void pingstats(int junk)
	{
	int status;

	signal(SIGINT, SIG_IGN);

	printf("\n--- %s ping statistics ---\n", hostent->h_name);
	printf("%ld packets transmitted, ", ntransmitted);
	printf("%ld packets received, ", nreceived);
	if (nrepeats)
	printf("%ld duplicates, ", nrepeats);
	if (ntransmitted)
	printf("%ld%% packet loss\n",
	(ntransmitted - nreceived) * 100 / ntransmitted);
	if (nreceived)
	printf("round-trip min/avg/max = %lu.%lu/%lu.%lu/%lu.%lu ms\n",
	tmin / 10, tmin % 10,
	(tsum / (nreceived + nrepeats)) / 10,
	(tsum / (nreceived + nrepeats)) % 10, tmax / 10, tmax % 10);
	if (nreceived != 0)
	status = EXIT_SUCCESS;
	else
	status = EXIT_FAILURE;
	exit(status);
	}

	static void sendping(int junk)
	{
	struct icmp *pkt;
	int i;
	char packet[datalen + ICMP_MINLEN];

	pkt = (struct icmp *) packet;

	pkt->icmp_type = ICMP_ECHO;
	pkt->icmp_code = 0;
	pkt->icmp_cksum = 0;
	pkt->icmp_seq = htons(ntransmitted++);
	pkt->icmp_id = myid;
	CLR(ntohs(pkt->icmp_seq) % MAX_DUP_CHK);

	gettimeofday((struct timeval *) &pkt->icmp_dun, NULL);
	pkt->icmp_cksum = in_cksum((unsigned short *) pkt, sizeof(packet));

	i = sendto(pingsock, packet, sizeof(packet), 0,
	(struct sockaddr *) &pingaddr, sizeof(struct sockaddr_in));

	if (i < 0)
	bb_perror_msg_and_die("sendto");
	else if ((size_t)i != sizeof(packet))
	bb_error_msg_and_die("ping wrote %d chars; %d expected", i,
	(int)sizeof(packet));

	signal(SIGALRM, sendping);
	if (pingcount == 0 \|\| ntransmitted < pingcount) { /* schedule next in 1s */
	alarm(PINGINTERVAL);
	} else { /* done, wait for the last ping to come back */
	/* todo, don't necessarily need to wait so long... */
	signal(SIGALRM, pingstats);
	alarm(MAXWAIT);
	}
	}

	static char *icmp_type_name(int id)
	{
	switch (id) {
	case ICMP_ECHOREPLY: return "Echo Reply";
	case ICMP_DEST_UNREACH: return "Destination Unreachable";
	case ICMP_SOURCE_QUENCH: return "Source Quench";
	case ICMP_REDIRECT: return "Redirect (change route)";
	case ICMP_ECHO: return "Echo Request";
	case ICMP_TIME_EXCEEDED: return "Time Exceeded";
	case ICMP_PARAMETERPROB: return "Parameter Problem";
	case ICMP_TIMESTAMP: return "Timestamp Request";
	case ICMP_TIMESTAMPREPLY: return "Timestamp Reply";
	case ICMP_INFO_REQUEST: return "Information Request";
	case ICMP_INFO_REPLY: return "Information Reply";
	case ICMP_ADDRESS: return "Address Mask Request";
	case ICMP_ADDRESSREPLY: return "Address Mask Reply";
	default: return "unknown ICMP type";
	}
	}

	static void unpack(char buf, int sz, struct sockaddr_in from)
	{
	struct icmp *icmppkt;
	struct iphdr *iphdr;
	struct timeval tv, *tp;
	int hlen, dupflag;
	unsigned long triptime;

	gettimeofday(&tv, NULL);

	/* discard if too short */
	if (sz < (datalen + ICMP_MINLEN))
	return;

	/* check IP header */
	iphdr = (struct iphdr *) buf;
	hlen = iphdr->ihl << 2;
	sz -= hlen;
	icmppkt = (struct icmp *) (buf + hlen);
	if (icmppkt->icmp_id != myid)
	return; /* not our ping */

	if (icmppkt->icmp_type == ICMP_ECHOREPLY) {
	u_int16_t recv_seq = ntohs(icmppkt->icmp_seq);
	++nreceived;
	tp = (struct timeval *) icmppkt->icmp_data;

	if ((tv.tv_usec -= tp->tv_usec) < 0) {
	--tv.tv_sec;
	tv.tv_usec += 1000000;
	}
	tv.tv_sec -= tp->tv_sec;

	triptime = tv.tv_sec * 10000 + (tv.tv_usec / 100);
	tsum += triptime;
	if (triptime < tmin)
	tmin = triptime;
	if (triptime > tmax)
	tmax = triptime;

	if (TST(recv_seq % MAX_DUP_CHK)) {
	++nrepeats;
	--nreceived;
	dupflag = 1;
	} else {
	SET(recv_seq % MAX_DUP_CHK);
	dupflag = 0;
	}

	if (options & O_QUIET)
	return;

	printf("%d bytes from %s: icmp_seq=%u", sz,
	inet_ntoa((struct in_addr ) &from->sin_addr.s_addr),
	recv_seq);
	printf(" ttl=%d", iphdr->ttl);
	printf(" time=%lu.%lu ms", triptime / 10, triptime % 10);
	if (dupflag)
	printf(" (DUP!)");
	printf("\n");
	} else
	if (icmppkt->icmp_type != ICMP_ECHO)
	bb_error_msg("Warning: Got ICMP %d (%s)",
	icmppkt->icmp_type, icmp_type_name(icmppkt->icmp_type));
	fflush(stdout);
	}

	static void ping(const char *host)
	{
	char packet[datalen + MAXIPLEN + MAXICMPLEN];
	int sockopt;

	pingsock = create_icmp_socket();

	if (sourceaddr.sin_addr.s_addr) {
	xbind(pingsock, (struct sockaddr*)&sourceaddr, sizeof(sourceaddr));
	}

	memset(&pingaddr, 0, sizeof(struct sockaddr_in));

	pingaddr.sin_family = AF_INET;
	hostent = xgethostbyname(host);
	if (hostent->h_addrtype != AF_INET)
	bb_error_msg_and_die("unknown address type; only AF_INET is currently supported");

	memcpy(&pingaddr.sin_addr, hostent->h_addr, sizeof(pingaddr.sin_addr));

	/* enable broadcast pings */
	sockopt = 1;
	setsockopt(pingsock, SOL_SOCKET, SO_BROADCAST, (char *) &sockopt,
	sizeof(sockopt));

	/* set recv buf for broadcast pings */
	sockopt = 48 * 1024;
	setsockopt(pingsock, SOL_SOCKET, SO_RCVBUF, (char *) &sockopt,
	sizeof(sockopt));

	printf("PING %s (%s)",
	hostent->h_name,
	inet_ntoa((struct in_addr ) &pingaddr.sin_addr.s_addr));
	if (sourceaddr.sin_addr.s_addr) {
	printf(" from %s",
	inet_ntoa((struct in_addr ) &sourceaddr.sin_addr.s_addr));
	}
	printf(": %d data bytes\n", datalen);

	signal(SIGINT, pingstats);

	/* start the ping's going ... */
	sendping(0);

	/* listen for replies */
	while (1) {
	struct sockaddr_in from;
	socklen_t fromlen = (socklen_t) sizeof(from);
	int c;

	if ((c = recvfrom(pingsock, packet, sizeof(packet), 0,
	(struct sockaddr *) &from, &fromlen)) < 0) {
	if (errno == EINTR)
	continue;
	bb_perror_msg("recvfrom");
	continue;
	}
	unpack(packet, c, &from);
	if (pingcount > 0 && nreceived >= pingcount)
	break;
	}
	pingstats(0);
	}

	/* TODO: consolidate ether-wake.c, dnsd.c, ifupdown.c, nslookup.c
	* versions of below thing. BTW we have far too many "%u.%u.%u.%u" too...
	*/
	static int parse_nipquad(const char str, struct sockaddr_in addr)
	{
	char dummy;
	unsigned i1, i2, i3, i4;
	if (sscanf(str, "%u.%u.%u.%u%c",
	&i1, &i2, &i3, &i4, &dummy) == 4
	&& ( (i1\|i2\|i3\|i4) <= 0xff )
	) {
	uint8_t* ptr = (uint8_t*)&addr->sin_addr;
	ptr[0] = i1;
	ptr[1] = i2;
	ptr[2] = i3;
	ptr[3] = i4;
	return 0;
	}
	return 1; /* error */
	}

	int ping_main(int argc, char **argv)
	{
	char *thisarg;

	datalen = DEFDATALEN; /* initialized here rather than in global scope to work around gcc bug */

	argc--;
	argv++;
	/* Parse any options */
	while (argc >= 1 && **argv == '-') {
	thisarg = *argv;
	thisarg++;
	switch (*thisarg) {
	case 'q':
	options \|= O_QUIET;
	break;
	case 'c':
	if (--argc <= 0)
	bb_show_usage();
	argv++;
	pingcount = atoi(*argv);
	break;
	case 's':
	if (--argc <= 0)
	bb_show_usage();
	argv++;
	datalen = atoi(*argv);
	break;
	case 'I':
	if (--argc <= 0)
	bb_show_usage();
	argv++;
	/* ping6 accepts iface too:
	if_index = if_nametoindex(*argv);
	if (!if_index) ...
	make it true for ping too. TODO.
	*/
	if (parse_nipquad(*argv, &sourceaddr))
	bb_show_usage();
	break;
	default:
	bb_show_usage();
	}
	argc--;
	argv++;
	}
	if (argc < 1)
	bb_show_usage();

	myid = (int16_t) getpid();
	ping(*argv);
	return EXIT_SUCCESS;
	}
	#endif /* ! CONFIG_FEATURE_FANCY_PING */