aboutsummaryrefslogtreecommitdiff
path: root/networking/ping.c
blob: 11138c036d657569597a75444bd92d8ef8cfe9e2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
/* vi: set sw=4 ts=4: */
/*
 * 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.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Mike Muuss.
 *
 * 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 "libbb.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,
	MAXIPLEN = 60,
	MAXICMPLEN = 76,
	MAXPACKET = 65468,
	MAX_DUP_CHK = (8 * 128),
	MAXWAIT = 10,
	PINGINTERVAL = 1, /* 1 second */
};

/* 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;
}

#if !ENABLE_FEATURE_FANCY_PING

/* simple version */

static char *hostname;

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

static void ping4(len_and_sockaddr *lsa)
{
	struct sockaddr_in pingaddr;
	struct icmp *pkt;
	int pingsock, c;
	char packet[DEFDATALEN + MAXIPLEN + MAXICMPLEN];

	pingsock = create_icmp_socket();
	pingaddr = lsa->u.sin;

	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 = xsendto(pingsock, packet, DEFDATALEN + ICMP_MINLEN,
			   (struct sockaddr *) &pingaddr, sizeof(pingaddr));

	/* listen for replies */
	while (1) {
		struct sockaddr_in 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 >= 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);
}

#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->u.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 = xsendto(pingsock, packet, DEFDATALEN + sizeof (struct icmp6_hdr),
			   (struct sockaddr *) &pingaddr, sizeof(pingaddr));

	/* 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) MAIN_EXTERNALLY_VISIBLE;
int ping_main(int argc, char **argv)
{
	len_and_sockaddr *lsa;
#if ENABLE_PING6
	sa_family_t af = AF_UNSPEC;

	while ((++argv)[0] && 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++;
#endif

	hostname = *argv;
	if (!hostname)
		bb_show_usage();

#if ENABLE_PING6
	lsa = xhost_and_af2sockaddr(hostname, 0, af);
#else
	lsa = xhost_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->u.sa.sa_family == AF_INET6)
		ping6(lsa);
	else
#endif
		ping4(lsa);
	printf("%s is alive!\n", hostname);
	return EXIT_SUCCESS;
}


#else /* FEATURE_FANCY_PING */


/* full(er) version */

#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,
};


struct globals {
	int pingsock;
	int if_index;
	char *opt_I;
	len_and_sockaddr *source_lsa;
	unsigned datalen;
	unsigned long ntransmitted, nreceived, nrepeats, pingcount;
	uint16_t myid;
	unsigned tmin, tmax; /* in us */
	unsigned long long tsum; /* in us, sum of all times */
	const char *hostname;
	const char *dotted;
	union {
		struct sockaddr sa;
		struct sockaddr_in sin;
#if ENABLE_PING6
		struct sockaddr_in6 sin6;
#endif
	} pingaddr;
	char rcvd_tbl[MAX_DUP_CHK / 8];
};
#define G (*(struct globals*)&bb_common_bufsiz1)
#define pingsock     (G.pingsock    )
#define if_index     (G.if_index    )
#define source_lsa   (G.source_lsa  )
#define opt_I        (G.opt_I       )
#define datalen      (G.datalen     )
#define ntransmitted (G.ntransmitted)
#define nreceived    (G.nreceived   )
#define nrepeats     (G.nrepeats    )
#define pingcount    (G.pingcount   )
#define myid         (G.myid        )
#define tmin         (G.tmin        )
#define tmax         (G.tmax        )
#define tsum         (G.tsum        )
#define hostname     (G.hostname    )
#define dotted       (G.dotted      )
#define pingaddr     (G.pingaddr    )
#define rcvd_tbl     (G.rcvd_tbl    )
void BUG_ping_globals_too_big(void);
#define INIT_G() do { \
	if (sizeof(G) > COMMON_BUFSIZE) \
		BUG_ping_globals_too_big(); \
	pingsock = -1; \
	tmin = UINT_MAX; \
} while (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 pingstats(int junk ATTRIBUTE_UNUSED)
{
	signal(SIGINT, SIG_IGN);

	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)
		ntransmitted = (ntransmitted - nreceived) * 100 / ntransmitted;
	printf("%lu%% packet loss\n", ntransmitted);
	if (tmin != UINT_MAX) {
		unsigned tavg = tsum / (nreceived + nrepeats);
		printf("round-trip min/avg/max = %u.%03u/%u.%03u/%u.%03u ms\n",
			tmin / 1000, tmin % 1000,
			tavg / 1000, tavg % 1000,
			tmax / 1000, tmax % 1000);
	}
	exit(nreceived == 0); /* (nreceived == 0) is true (1) -- 'failure' */
}

static void sendping_tail(void (*sp)(int), const void *pkt, int size_pkt)
{
	int sz;

	CLR((uint16_t)ntransmitted % MAX_DUP_CHK);
	ntransmitted++;

	/* sizeof(pingaddr) can be larger than real sa size, but I think
	 * it doesn't matter */
	sz = xsendto(pingsock, pkt, size_pkt, &pingaddr.sa, sizeof(pingaddr));
	if (sz != size_pkt)
		bb_error_msg_and_die(bb_msg_write_error);

	signal(SIGALRM, sp);
	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 void sendping4(int junk ATTRIBUTE_UNUSED)
{
	/* +4 reserves a place for timestamp, which may end up sitting
	 * *after* packet. Saves one if() */
	struct icmp *pkt = alloca(datalen + ICMP_MINLEN + 4);

	pkt->icmp_type = ICMP_ECHO;
	pkt->icmp_code = 0;
	pkt->icmp_cksum = 0;
	pkt->icmp_seq = htons(ntransmitted); /* don't ++ here, it can be a macro */
	pkt->icmp_id = myid;

	/* We don't do hton, because we will read it back on the same machine */
	/*if (datalen >= 4)*/
		*(uint32_t*)&pkt->icmp_dun = monotonic_us();

	pkt->icmp_cksum = in_cksum((unsigned short *) pkt, datalen + ICMP_MINLEN);

	sendping_tail(sendping4, pkt, datalen + ICMP_MINLEN);
}
#if ENABLE_PING6
static void sendping6(int junk ATTRIBUTE_UNUSED)
{
	struct icmp6_hdr *pkt = alloca(datalen + sizeof(struct icmp6_hdr) + 4);

	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;

	/*if (datalen >= 4)*/
		*(uint32_t*)(&pkt->icmp6_data8[4]) = monotonic_us();

	sendping_tail(sendping6, pkt, datalen + sizeof(struct icmp6_hdr));
}
#endif

static const 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";
	}
}
#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 const 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_tail(int sz, uint32_t *tp,
		const char *from_str,
		uint16_t recv_seq, int ttl)
{
	const char *dupmsg = " (DUP!)";
	unsigned triptime = triptime; /* for gcc */

	++nreceived;

	if (tp) {
		/* (int32_t) cast is for hypothetical 64-bit unsigned */
		/* (doesn't hurt 32-bit real-world anyway) */
		triptime = (int32_t) ((uint32_t)monotonic_us() - *tp);
		tsum += triptime;
		if (triptime < tmin)
			tmin = triptime;
		if (triptime > tmax)
			tmax = triptime;
	}

	if (TST(recv_seq % MAX_DUP_CHK)) {
		++nrepeats;
		--nreceived;
	} else {
		SET(recv_seq % MAX_DUP_CHK);
		dupmsg += 7;
	}

	if (option_mask32 & OPT_QUIET)
		return;

	printf("%d bytes from %s: seq=%u ttl=%d", sz,
		from_str, recv_seq, ttl);
	if (tp)
		printf(" time=%u.%03u ms", triptime / 1000, triptime % 1000);
	puts(dupmsg);
	fflush(stdout);
}
static void unpack4(char *buf, int sz, struct sockaddr_in *from)
{
	struct icmp *icmppkt;
	struct iphdr *iphdr;
	int hlen;

	/* 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) {
		uint16_t recv_seq = ntohs(icmppkt->icmp_seq);
		uint32_t *tp = NULL;

		if (sz >= ICMP_MINLEN + sizeof(uint32_t))
			tp = (uint32_t *) icmppkt->icmp_data;
		unpack_tail(sz, tp,
			inet_ntoa(*(struct in_addr *) &from->sin_addr.s_addr),
			recv_seq, iphdr->ttl);
	} else if (icmppkt->icmp_type != ICMP_ECHO) {
		bb_error_msg("warning: got ICMP %d (%s)",
				icmppkt->icmp_type,
				icmp_type_name(icmppkt->icmp_type));
	}
}
#if ENABLE_PING6
static void unpack6(char *packet, int sz, struct sockaddr_in6 *from, int hoplimit)
{
	struct icmp6_hdr *icmppkt;
	char buf[INET6_ADDRSTRLEN];

	/* 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);
		uint32_t *tp = NULL;

		if (sz >= sizeof(struct icmp6_hdr) + sizeof(uint32_t))
			tp = (uint32_t *) &icmppkt->icmp6_data8[4];
		unpack_tail(sz, tp,
			inet_ntop(AF_INET6, &pingaddr.sin6.sin6_addr,
					buf, sizeof(buf)),
			recv_seq, hoplimit);
	} 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));
	}
}
#endif

static void ping4(len_and_sockaddr *lsa)
{
	char packet[datalen + MAXIPLEN + MAXICMPLEN];
	int sockopt;

	pingsock = create_icmp_socket();
	pingaddr.sin = lsa->u.sin;
	if (source_lsa) {
		if (setsockopt(pingsock, IPPROTO_IP, IP_MULTICAST_IF,
				&source_lsa->u.sa, source_lsa->len))
			bb_error_msg_and_die("can't set multicast source interface");
		xbind(pingsock, &source_lsa->u.sa, source_lsa->len);
	}
	if (opt_I)
		setsockopt(pingsock, SOL_SOCKET, SO_BINDTODEVICE, opt_I, strlen(opt_I) + 1);

	/* 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));

	signal(SIGINT, pingstats);

	/* start the ping's going ... */
	sendping4(0);

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

		c = recvfrom(pingsock, packet, sizeof(packet), 0,
				(struct sockaddr *) &from, &fromlen);
		if (c < 0) {
			if (errno != EINTR)
				bb_perror_msg("recvfrom");
			continue;
		}
		unpack4(packet, c, &from);
		if (pingcount > 0 && nreceived >= pingcount)
			break;
	}
}
#if ENABLE_PING6
extern int BUG_bad_offsetof_icmp6_cksum(void);
static void ping6(len_and_sockaddr *lsa)
{
	char packet[datalen + MAXIPLEN + MAXICMPLEN];
	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->u.sin6;
	/* untested whether "-I addr" really works for IPv6: */
	if (source_lsa)
		xbind(pingsock, &source_lsa->u.sa, source_lsa->len);
	if (opt_I)
		setsockopt(pingsock, SOL_SOCKET, SO_BINDTODEVICE, opt_I, strlen(opt_I) + 1);

#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.sin6_scope_id = if_index;

	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

static void ping(len_and_sockaddr *lsa)
{
	printf("PING %s (%s)", hostname, dotted);
	if (source_lsa) {
		printf(" from %s",
			xmalloc_sockaddr2dotted_noport(&source_lsa->u.sa));
	}
	printf(": %d data bytes\n", datalen);

#if ENABLE_PING6
	if (lsa->u.sa.sa_family == AF_INET6)
		ping6(lsa);
	else
#endif
		ping4(lsa);
}

int ping_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int ping_main(int argc, char **argv)
{
	len_and_sockaddr *lsa;
	char *opt_c, *opt_s;
	USE_PING6(sa_family_t af = AF_UNSPEC;)

	INIT_G();

	datalen = DEFDATALEN;

	/* exactly one argument needed, -v and -q don't mix */
	opt_complementary = "=1:q--v:v--q";
	getopt32(argv, OPT_STRING, &opt_c, &opt_s, &opt_I);
	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) {
			/* TODO: I'm not sure it takes IPv6 unless in [XX:XX..] format */
			source_lsa = xdotted2sockaddr(opt_I, 0);
			opt_I = NULL; /* don't try to bind to device later */
		}
	}
	myid = (uint16_t) getpid();
	hostname = argv[optind];
#if ENABLE_PING6
	if (option_mask32 & OPT_IPV4)
		af = AF_INET;
	if (option_mask32 & OPT_IPV6)
		af = AF_INET6;
	lsa = xhost_and_af2sockaddr(hostname, 0, af);
#else
	lsa = xhost_and_af2sockaddr(hostname, 0, AF_INET);
#endif

	if (source_lsa && source_lsa->u.sa.sa_family != lsa->u.sa.sa_family)
		/* leaking it here... */
		source_lsa = NULL;

	dotted = xmalloc_sockaddr2dotted_noport(&lsa->u.sa);
	ping(lsa);
	pingstats(0);
	return EXIT_SUCCESS;
}
#endif /* FEATURE_FANCY_PING */


#if ENABLE_PING6
int ping6_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int ping6_main(int argc, char **argv)
{
	argv[0] = (char*)"-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.
 */