Unify ping and ping6. ping has -4 and -6 which force

name resolution into IP or IPv6 only, otherwise
we take address family returned by host2sockaddr()
in lsa->sa.sa_family. IOW: "ping ::1" with do IPv6 ping,
"ping 127.0.0.1" will do IPv4 ping.
ping6 is aliased to "ping -6".

1 files changed, 452 insertions, 69 deletions

diff --git a/networking/ping.c b/networking/ping.c
index fc2de456a..7d36b7455 100644
--- a/networking/ping.c
+++ b/networking/ping.c
@@ -13,9 +13,30 @@
  *
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */
+/* from ping6.c:
+ * Copyright (C) 1999 by Randolph Chung <tausq@debian.org>
+ *
+ * This version of ping is adapted from the ping in netkit-base 0.10,
+ * which is:
+ *
+ * Original copyright notice is retained at the end of this file.
+ *
+ * This version is an adaptation of ping.c from busybox.
+ * The code was modified by Bart Visscher <magick@linux-fan.com>
+ */
 
+#include <net/if.h>
 #include <netinet/ip_icmp.h>
 #include "busybox.h"
+#if ENABLE_PING6
+#include <netinet/icmp6.h>
+/* I see RENUMBERED constants in bits/in.h - !!?
+ * What a fuck is going on with libc? Is it a glibc joke? */
+#ifdef IPV6_2292HOPLIMIT
+#undef IPV6_HOPLIMIT
+#define IPV6_HOPLIMIT IPV6_2292HOPLIMIT
+#endif
+#endif
 
 enum {
 	DEFDATALEN = 56,
@@ -24,11 +45,9 @@ enum {
 	MAXPACKET = 65468,
 	MAX_DUP_CHK = (8 * 128),
 	MAXWAIT = 10,
-	PINGINTERVAL = 1		/* second */
+	PINGINTERVAL = 1, /* 1 second */
 };
 
-static void ping(const char *host);
-
 /* common routines */
 
 static int in_cksum(unsigned short *buf, int sz)
@@ -54,34 +73,27 @@ static int in_cksum(unsigned short *buf, int sz)
 	return ans;
 }
 
-#ifndef CONFIG_FEATURE_FANCY_PING
+#if !ENABLE_FEATURE_FANCY_PING
 
 /* simple version */
 
 static char *hostname;
 
-static void noresp(int ign)
+static void noresp(int ign ATTRIBUTE_UNUSED)
 {
 	printf("No response from %s\n", hostname);
 	exit(EXIT_FAILURE);
 }
 
-static void ping(const char *host)
+static void ping(len_and_sockaddr *lsa)
 {
-	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(pingaddr));
-
-	pingaddr.sin_family = AF_INET;
-	h = xgethostbyname(host);
-	memcpy(&pingaddr.sin_addr, h->h_addr, sizeof(pingaddr.sin_addr));
-	hostname = h->h_name;
+	pingaddr = lsa->sin;
 
 	pkt = (struct icmp *) packet;
 	memset(pkt, 0, sizeof(packet));
@@ -89,15 +101,14 @@ static void ping(const char *host)
 	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));
+			   (struct sockaddr *) &pingaddr, sizeof(pingaddr));
 
 	if (c < 0) {
-		if (ENABLE_FEATURE_CLEAN_UP) close(pingsock);
+		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;
@@ -120,43 +131,140 @@ static void ping(const char *host)
 	}
 	if (ENABLE_FEATURE_CLEAN_UP)
 		close(pingsock);
-	printf("%s is alive!\n", hostname);
 }
 
+#if ENABLE_PING6
+static void ping6(len_and_sockaddr *lsa)
+{
+	struct sockaddr_in6 pingaddr;
+	struct icmp6_hdr *pkt;
+	int pingsock, c;
+	int sockopt;
+	char packet[DEFDATALEN + MAXIPLEN + MAXICMPLEN];
+
+	pingsock = create_icmp6_socket();
+	pingaddr = lsa->sin6;
+
+	pkt = (struct icmp6_hdr *) packet;
+	memset(pkt, 0, sizeof(packet));
+	pkt->icmp6_type = ICMP6_ECHO_REQUEST;
+
+	sockopt = offsetof(struct icmp6_hdr, icmp6_cksum);
+	setsockopt(pingsock, SOL_RAW, IPV6_CHECKSUM, &sockopt, sizeof(sockopt));
+
+	c = sendto(pingsock, packet, DEFDATALEN + sizeof (struct icmp6_hdr), 0,
+			   (struct sockaddr *) &pingaddr, sizeof(pingaddr));
+
+	if (c < 0) {
+		if (ENABLE_FEATURE_CLEAN_UP)
+			close(pingsock);
+		bb_perror_msg_and_die("sendto");
+	}
+
+	/* listen for replies */
+	while (1) {
+		struct sockaddr_in6 from;
+		socklen_t fromlen = sizeof(from);
+
+		c = recvfrom(pingsock, packet, sizeof(packet), 0,
+				(struct sockaddr *) &from, &fromlen);
+		if (c < 0) {
+			if (errno != EINTR)
+				bb_perror_msg("recvfrom");
+			continue;
+		}
+		if (c >= 8) {			/* icmp6_hdr */
+			pkt = (struct icmp6_hdr *) packet;
+			if (pkt->icmp6_type == ICMP6_ECHO_REPLY)
+				break;
+		}
+	}
+	if (ENABLE_FEATURE_CLEAN_UP)
+		close(pingsock);
+}
+#endif
+
 int ping_main(int argc, char **argv)
 {
-	argc--;
+	len_and_sockaddr *lsa;
+#if ENABLE_PING6
+	sa_family_t af = AF_UNSPEC;
+	while (++argv[0][0]) == '-') {
+		if (argv[0][1] == '4') {
+			af = AF_INET;
+			continue;
+		}
+		if (argv[0][1] == '6') {
+			af = AF_INET6;
+			continue;
+		}
+		bb_show_usage();
+	}
+#else
 	argv++;
-	if (argc < 1)
+#endif
+
+	hostname = *argv;
+	if (!hostname)
 		bb_show_usage();
-	ping(*argv);
+
+#if ENABLE_PING6
+	lsa = host_and_af2sockaddr(hostname, 0, af);
+#else
+	lsa = host_and_af2sockaddr(hostname, 0, AF_INET);
+#endif
+	/* Set timer _after_ DNS resolution */
+	signal(SIGALRM, noresp);
+	alarm(5); /* give the host 5000ms to respond */
+
+#if ENABLE_PING6
+	if (lsa->sa.sa_family == AF_INET6)
+		ping6(lsa);
+	else
+#endif
+		ping(lsa);
+	printf("%s is alive!\n", hostname);
 	return EXIT_SUCCESS;
 }
 
-#else /* ! CONFIG_FEATURE_FANCY_PING */
+
+#else /* FEATURE_FANCY_PING */
+
 
 /* full(er) version */
 
-#define OPT_STRING "qc:s:I:"
+#define OPT_STRING ("qvc:s:I:4" USE_PING6("6"))
 enum {
 	OPT_QUIET = 1 << 0,
+	OPT_VERBOSE = 1 << 1,
+	OPT_c = 1 << 2,
+	OPT_s = 1 << 3,
+	OPT_I = 1 << 4,
+	OPT_IPV4 = 1 << 5,
+	OPT_IPV6 = (1 << 6) * ENABLE_PING6,
 };
 
-static struct sockaddr_in pingaddr;
+
+static union {
+	struct sockaddr sa;
+	struct sockaddr_in sin;
+#if ENABLE_PING6
+	struct sockaddr_in sin6;
+#endif
+} pingaddr;
 static struct sockaddr_in sourceaddr;
 static int pingsock = -1;
 static unsigned datalen; /* intentionally uninitialized to work around gcc bug */
 
+static int if_index;
+
 static unsigned long ntransmitted, nreceived, nrepeats, pingcount;
 static int myid;
 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 const char *hostname;
+static const char *dotted;
 
 #define	A(bit)		rcvd_tbl[(bit)>>3]	/* identify byte in array */
 #define	B(bit)		(1 << ((bit) & 0x07))	/* identify bit in byte */
@@ -166,25 +274,25 @@ static void unpack(char *, int, struct sockaddr_in *);
 
 /**************************************************************************/
 
-static void pingstats(int junk)
+static void pingstats(void)
 {
 	int status;
 
 	signal(SIGINT, SIG_IGN);
 
-	printf("\n--- %s ping statistics ---\n", hostent->h_name);
+	printf("\n--- %s ping statistics ---\n", hostname);
 	printf("%lu packets transmitted, ", ntransmitted);
 	printf("%lu packets received, ", nreceived);
 	if (nrepeats)
 		printf("%lu duplicates, ", nrepeats);
 	if (ntransmitted)
-		printf("%lu%% packet loss\n",
-			   (ntransmitted - nreceived) * 100 / ntransmitted);
+		ntransmitted = (ntransmitted - nreceived) * 100 / ntransmitted);
+	printf("%lu%% packet loss\n", 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);
+			tmin / 10, tmin % 10,
+			(tsum / (nreceived + nrepeats)) / 10,
+			(tsum / (nreceived + nrepeats)) % 10, tmax / 10, tmax % 10);
 	if (nreceived != 0)
 		status = EXIT_SUCCESS;
 	else
@@ -192,7 +300,7 @@ static void pingstats(int junk)
 	exit(status);
 }
 
-static void sendping(int junk)
+static void sendping(int junk ATTRIBUTE_UNUSED)
 {
 	struct icmp *pkt;
 	int i;
@@ -212,7 +320,7 @@ static void sendping(int junk)
 	pkt->icmp_cksum = in_cksum((unsigned short *) pkt, sizeof(packet));
 
 	i = sendto(pingsock, packet, sizeof(packet), 0,
-			   (struct sockaddr *) &pingaddr, sizeof(struct sockaddr_in));
+			&pingaddr.sa, sizeof(pingaddr.sin));
 
 	if (i < 0)
 		bb_perror_msg_and_die("sendto");
@@ -223,12 +331,50 @@ static void sendping(int junk)
 	signal(SIGALRM, sendping);
 	if (pingcount == 0 || ntransmitted < pingcount) {	/* schedule next in 1s */
 		alarm(PINGINTERVAL);
-	} else {					/* done, wait for the last ping to come back */
+	} else { /* done, wait for the last ping to come back */
+		/* todo, don't necessarily need to wait so long... */
+		signal(SIGALRM, pingstats);
+		alarm(MAXWAIT);
+	}
+}
+#if ENABLE_PING6
+static void sendping6(int junk ATTRIBUTE_UNUSED)
+{
+	struct icmp6_hdr *pkt;
+	int i;
+	char packet[datalen + sizeof (struct icmp6_hdr)];
+
+	pkt = (struct icmp6_hdr *) packet;
+
+	pkt->icmp6_type = ICMP6_ECHO_REQUEST;
+	pkt->icmp6_code = 0;
+	pkt->icmp6_cksum = 0;
+	pkt->icmp6_seq = htons(ntransmitted); /* don't ++ here, it can be a macro */
+	pkt->icmp6_id = myid;
+	CLR((uint16_t)ntransmitted % MAX_DUP_CHK);
+	ntransmitted++;
+
+	gettimeofday((struct timeval *) &pkt->icmp6_data8[4], NULL);
+
+	i = sendto(pingsock, packet, sizeof(packet), 0,
+			&pingaddr.sa, sizeof(pingaddr.sin6));
+
+	if (i < 0)
+		bb_perror_msg_and_die("sendto");
+	if ((size_t)i != sizeof(packet))
+		bb_error_msg_and_die("ping wrote %d chars; %d expected", i,
+			   (int)sizeof(packet));
+
+	signal(SIGALRM, sendping6);
+	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);
 	}
 }
+#endif
 
 static char *icmp_type_name(int id)
 {
@@ -249,6 +395,34 @@ static char *icmp_type_name(int id)
 	default:                  return "unknown ICMP type";
 	}
 }
+#if ENABLE_PING6
+/* RFC3542 changed some definitions from RFC2292 for no good reason, whee!
+ * the newer 3542 uses a MLD_ prefix where as 2292 uses ICMP6_ prefix */
+#ifndef MLD_LISTENER_QUERY
+# define MLD_LISTENER_QUERY ICMP6_MEMBERSHIP_QUERY
+#endif
+#ifndef MLD_LISTENER_REPORT
+# define MLD_LISTENER_REPORT ICMP6_MEMBERSHIP_REPORT
+#endif
+#ifndef MLD_LISTENER_REDUCTION
+# define MLD_LISTENER_REDUCTION ICMP6_MEMBERSHIP_REDUCTION
+#endif
+static char *icmp6_type_name(int id)
+{
+	switch (id) {
+	case ICMP6_DST_UNREACH:      return "Destination Unreachable";
+	case ICMP6_PACKET_TOO_BIG:   return "Packet too big";
+	case ICMP6_TIME_EXCEEDED:    return "Time Exceeded";
+	case ICMP6_PARAM_PROB:       return "Parameter Problem";
+	case ICMP6_ECHO_REPLY:       return "Echo Reply";
+	case ICMP6_ECHO_REQUEST:     return "Echo Request";
+	case MLD_LISTENER_QUERY:     return "Listener Query";
+	case MLD_LISTENER_REPORT:    return "Listener Report";
+	case MLD_LISTENER_REDUCTION: return "Listener Reduction";
+	default:                     return "unknown ICMP type";
+	}
+}
+#endif
 
 static void unpack(char *buf, int sz, struct sockaddr_in *from)
 {
@@ -318,27 +492,85 @@ static void unpack(char *buf, int sz, struct sockaddr_in *from)
 	}
 	fflush(stdout);
 }
+#if ENABLE_PING6
+static void unpack6(char *packet, int sz, struct sockaddr_in6 *from, int hoplimit)
+{
+	struct icmp6_hdr *icmppkt;
+	struct timeval tv, *tp;
+	int dupflag;
+	unsigned long triptime;
+	char buf[INET6_ADDRSTRLEN];
+
+	gettimeofday(&tv, NULL);
+
+	/* discard if too short */
+	if (sz < (datalen + sizeof(struct icmp6_hdr)))
+		return;
+
+	icmppkt = (struct icmp6_hdr *) packet;
+	if (icmppkt->icmp6_id != myid)
+		return;				/* not our ping */
+
+	if (icmppkt->icmp6_type == ICMP6_ECHO_REPLY) {
+		uint16_t recv_seq = ntohs(icmppkt->icmp6_seq);
+		++nreceived;
+		tp = (struct timeval *) &icmppkt->icmp6_data8[4];
+
+		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 (option_mask32 & OPT_QUIET)
+			return;
+
+		printf("%d bytes from %s: icmp6_seq=%u", sz,
+			   inet_ntop(AF_INET6, &pingaddr.sin6.sin6_addr,
+						 buf, sizeof(buf)),
+			   recv_seq);
+		printf(" ttl=%d time=%lu.%lu ms", hoplimit,
+			   triptime / 10, triptime % 10);
+		if (dupflag)
+			printf(" (DUP!)");
+		puts("");
+	} else {
+		if (icmppkt->icmp6_type != ICMP6_ECHO_REQUEST)
+			bb_error_msg("warning: got ICMP %d (%s)",
+					icmppkt->icmp6_type,
+					icmp6_type_name(icmppkt->icmp6_type));
+	}
+	fflush(stdout);
+}
+#endif
 
-static void ping(const char *host)
+static void ping(len_and_sockaddr *lsa)
 {
 	char packet[datalen + MAXIPLEN + MAXICMPLEN];
 	int sockopt;
 
 	pingsock = create_icmp_socket();
-
+	pingaddr.sin = lsa->sin;
 	if (sourceaddr.sin_addr.s_addr) {
 		xbind(pingsock, (struct sockaddr*)&sourceaddr, sizeof(sourceaddr));
 	}
 
-	memset(&pingaddr, 0, sizeof(pingaddr));
-
-	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 */
 	setsockopt_broadcast(pingsock);
 
@@ -346,9 +578,7 @@ static void ping(const char *host)
 	sockopt = 48 * 1024; /* explain why 48k? */
 	setsockopt(pingsock, SOL_SOCKET, SO_RCVBUF, &sockopt, sizeof(sockopt));
 
-	printf("PING %s (%s)",
-			hostent->h_name,
-			inet_ntoa(*(struct in_addr *) &pingaddr.sin_addr.s_addr));
+	printf("PING %s (%s)", hostname, dotted);
 	if (sourceaddr.sin_addr.s_addr) {
 		printf(" from %s",
 			inet_ntoa(*(struct in_addr *) &sourceaddr.sin_addr.s_addr));
@@ -377,8 +607,100 @@ static void ping(const char *host)
 		if (pingcount > 0 && nreceived >= pingcount)
 			break;
 	}
-	pingstats(0);
 }
+#if ENABLE_PING6
+extern int BUG_bad_offsetof_icmp6_cksum(void);
+static void ping6(len_and_sockaddr *lsa)
+{
+	char packet[datalen + MAXIPLEN + MAXICMPLEN];
+	char buf[INET6_ADDRSTRLEN];
+	int sockopt;
+	struct msghdr msg;
+	struct sockaddr_in6 from;
+	struct iovec iov;
+	char control_buf[CMSG_SPACE(36)];
+
+	pingsock = create_icmp6_socket();
+	pingaddr.sin6 = lsa->sin6;
+	//if (sourceaddr.sin_addr.s_addr) {
+	//	xbind(pingsock, (struct sockaddr*)&sourceaddr, sizeof(sourceaddr));
+	//}
+
+#ifdef ICMP6_FILTER
+	{
+		struct icmp6_filter filt;
+		if (!(option_mask32 & OPT_VERBOSE)) {
+			ICMP6_FILTER_SETBLOCKALL(&filt);
+			ICMP6_FILTER_SETPASS(ICMP6_ECHO_REPLY, &filt);
+		} else {
+			ICMP6_FILTER_SETPASSALL(&filt);
+		}
+		if (setsockopt(pingsock, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
+					   sizeof(filt)) < 0)
+			bb_error_msg_and_die("setsockopt(ICMP6_FILTER)");
+	}
+#endif /*ICMP6_FILTER*/
+
+	/* enable broadcast pings */
+	setsockopt_broadcast(pingsock);
+
+	/* set recv buf for broadcast pings */
+	sockopt = 48 * 1024; /* explain why 48k? */
+	setsockopt(pingsock, SOL_SOCKET, SO_RCVBUF, &sockopt, sizeof(sockopt));
+
+	sockopt = offsetof(struct icmp6_hdr, icmp6_cksum);
+	if (offsetof(struct icmp6_hdr, icmp6_cksum) != 2)
+		BUG_bad_offsetof_icmp6_cksum();
+	setsockopt(pingsock, SOL_RAW, IPV6_CHECKSUM, &sockopt, sizeof(sockopt));
+
+	/* request ttl info to be returned in ancillary data */
+	setsockopt(pingsock, SOL_IPV6, IPV6_HOPLIMIT, &const_int_1, sizeof(const_int_1));
+
+	if (if_index)
+		pingaddr.sin6_scope_id = if_index;
+
+	printf("PING %s (%s): %d data bytes\n", hostname, dotted, datalen);
+
+	signal(SIGINT, pingstats);
+
+	/* start the ping's going ... */
+	sendping6(0);
+
+	/* listen for replies */
+	msg.msg_name = &from;
+	msg.msg_namelen = sizeof(from);
+	msg.msg_iov = &iov;
+	msg.msg_iovlen = 1;
+	msg.msg_control = control_buf;
+	iov.iov_base = packet;
+	iov.iov_len = sizeof(packet);
+	while (1) {
+		int c;
+		struct cmsghdr *mp;
+		int hoplimit = -1;
+		msg.msg_controllen = sizeof(control_buf);
+
+		c = recvmsg(pingsock, &msg, 0);
+		if (c < 0) {
+			if (errno != EINTR)
+				bb_perror_msg("recvfrom");
+			continue;
+		}
+		for (mp = CMSG_FIRSTHDR(&msg); mp; mp = CMSG_NXTHDR(&msg, mp)) {
+			if (mp->cmsg_level == SOL_IPV6
+			 && mp->cmsg_type == IPV6_HOPLIMIT
+			 /* don't check len - we trust the kernel: */
+			 /* && mp->cmsg_len >= CMSG_LEN(sizeof(int)) */
+			) {
+				hoplimit = *(int*)CMSG_DATA(mp);
+			}
+		}
+		unpack6(packet, c, &from, hoplimit);
+		if (pingcount > 0 && nreceived >= pingcount)
+			break;
+	}
+}
+#endif
 
 /* 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...
@@ -403,26 +725,87 @@ static int parse_nipquad(const char *str, struct sockaddr_in* addr)
 
 int ping_main(int argc, char **argv)
 {
+	const char *hostname;
 	char *opt_c, *opt_s, *opt_I;
+	USE_PING6(sa_family_t af = AF_UNSPEC;)
 
 	datalen = DEFDATALEN; /* initialized here rather than in global scope to work around gcc bug */
 
-	/* exactly one argument needed */
-	opt_complementary = "=1";
+	/* exactly one argument needed, -v and -q don't mix. So do 4, 6 */
+	opt_complementary = "=1:q--v:v--q" USE_PING6(":4--6:6--4");
 	getopt32(argc, argv, OPT_STRING, &opt_c, &opt_s, &opt_I);
-	if (option_mask32 & 2) pingcount = xatoul(opt_c); // -c
-	if (option_mask32 & 4) datalen = xatou16(opt_s); // -s
-	if (option_mask32 & 8) { // -I
-/* TODO: ping6 accepts iface too:
-		if_index = if_nametoindex(*argv);
-		if (!if_index) ...
-make it true for ping. */
-		if (parse_nipquad(opt_I, &sourceaddr))
-			bb_show_usage();
+	if (option_mask32 & OPT_c) pingcount = xatoul(opt_c); // -c
+	if (option_mask32 & OPT_s) datalen = xatou16(opt_s); // -s
+	if (option_mask32 & OPT_I) { // -I
+		if_index = if_nametoindex(opt_I);
+		if (!if_index)
+			if (parse_nipquad(opt_I, &sourceaddr))
+				bb_show_usage();
 	}
-
 	myid = (int16_t) getpid();
-	ping(argv[optind]);
+	hostname = argv[optind];
+#if ENABLE_PING6
+	if (option_mask32 & OPT_IPV4)
+		af = AF_INET;
+	if (option_mask32 & OPT_IPV6)
+		af = AF_INET6;
+	lsa = host_and_af2sockaddr(hostname, 0, af);
+#else
+	lsa = host_and_af2sockaddr(hostname, 0, AF_INET);
+#endif
+	dotted = xmalloc_sockaddr2dotted_noport(lsa->sa, lsa->len);
+#if ENABLE_PING6
+	if (lsa->sa.sa_family == AF_INET6)
+		ping6(lsa);
+	else
+#endif
+		ping(lsa);
+	pingstats();
 	return EXIT_SUCCESS;
 }
-#endif /* ! CONFIG_FEATURE_FANCY_PING */
+#endif /* FEATURE_FANCY_PING */
+
+
+#if ENABLE_PING6
+int ping6_main(int argc, char **argv)
+{
+	argv[0] = "-6";
+	return ping_main(argc + 1, argv - 1);
+}
+#endif
+
+/* from ping6.c:
+ * Copyright (c) 1989 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. <BSD Advertising Clause omitted per the July 22, 1999 licensing change
+ *		ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change>
+ *
+ * 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.
+ */