Home | History | Annotate | Download | only in iputils
      1 /*
      2  *
      3  *	Modified for AF_INET6 by Pedro Roque
      4  *
      5  *	<roque (at) di.fc.ul.pt>
      6  *
      7  *	Original copyright notice included bellow
      8  */
      9 
     10 /*
     11  * Copyright (c) 1989 The Regents of the University of California.
     12  * All rights reserved.
     13  *
     14  * This code is derived from software contributed to Berkeley by
     15  * Mike Muuss.
     16  *
     17  * Redistribution and use in source and binary forms, with or without
     18  * modification, are permitted provided that the following conditions
     19  * are met:
     20  * 1. Redistributions of source code must retain the above copyright
     21  *    notice, this list of conditions and the following disclaimer.
     22  * 2. Redistributions in binary form must reproduce the above copyright
     23  *    notice, this list of conditions and the following disclaimer in the
     24  *    documentation and/or other materials provided with the distribution.
     25  * 3. All advertising materials mentioning features or use of this software
     26  *    must display the following acknowledgement:
     27  *	This product includes software developed by the University of
     28  *	California, Berkeley and its contributors.
     29  * 4. Neither the name of the University nor the names of its contributors
     30  *    may be used to endorse or promote products derived from this software
     31  *    without specific prior written permission.
     32  *
     33  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     34  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     35  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     36  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     37  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     38  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     39  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     40  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     41  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     42  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     43  * SUCH DAMAGE.
     44  */
     45 
     46 #ifndef lint
     47 char copyright[] =
     48 "@(#) Copyright (c) 1989 The Regents of the University of California.\n\
     49  All rights reserved.\n";
     50 #endif /* not lint */
     51 
     52 /*
     53  *			P I N G . C
     54  *
     55  * Using the InterNet Control Message Protocol (ICMP) "ECHO" facility,
     56  * measure round-trip-delays and packet loss across network paths.
     57  *
     58  * Author -
     59  *	Mike Muuss
     60  *	U. S. Army Ballistic Research Laboratory
     61  *	December, 1983
     62  *
     63  * Status -
     64  *	Public Domain.  Distribution Unlimited.
     65  * Bugs -
     66  *	More statistics could always be gathered.
     67  *	This program has to run SUID to ROOT to access the ICMP socket.
     68  */
     69 #include "ping_common.h"
     70 
     71 #include <linux/filter.h>
     72 #include <netinet/ip6.h>
     73 #include <netinet/icmp6.h>
     74 #include <resolv.h>
     75 #ifndef WITHOUT_IFADDRS
     76 #include <ifaddrs.h>
     77 #endif
     78 
     79 #ifdef USE_IDN
     80 #include <stringprep.h>
     81 #endif
     82 
     83 #include "ping6_niquery.h"
     84 #include "in6_flowlabel.h"
     85 
     86 #ifndef SOL_IPV6
     87 #define SOL_IPV6 IPPROTO_IPV6
     88 #endif
     89 
     90 #ifndef SOL_ICMPV6
     91 #define SOL_ICMPV6 IPPROTO_ICMPV6
     92 #endif
     93 
     94 /* RFC3542 */
     95 #ifndef ICMP6_DST_UNREACH_BEYONDSCOPE
     96 #define ICMP6_DST_UNREACH_BEYONDSCOPE ICMP6_DST_UNREACH_NOTNEIGHBOR
     97 #endif
     98 
     99 #if defined(ENABLE_PING6_RTHDR) && !defined(ENABLE_PING6_RTHDR_RFC3542)
    100 #ifndef IPV6_SRCRT_TYPE_0
    101 #define IPV6_SRCRT_TYPE_0	0
    102 #endif
    103 #endif
    104 
    105 #ifndef MLD_LISTENER_QUERY
    106 #define MLD_LISTENER_QUERY	130
    107 #define MLD_LISTENER_REPORT	131
    108 #define MLD_LISTENER_REDUCTION	132
    109 #endif
    110 
    111 #define BIT_CLEAR(nr, addr) do { ((__u32 *)(addr))[(nr) >> 5] &= ~(1U << ((nr) & 31)); } while(0)
    112 #define BIT_SET(nr, addr) do { ((__u32 *)(addr))[(nr) >> 5] |= (1U << ((nr) & 31)); } while(0)
    113 #define BIT_TEST(nr, addr) do { (__u32 *)(addr))[(nr) >> 5] & (1U << ((nr) & 31)); } while(0)
    114 
    115 #ifndef ICMP6_FILTER_WILLPASS
    116 #define ICMP6_FILTER_WILLPASS(type, filterp) \
    117 	(BIT_TEST((type), filterp) == 0)
    118 
    119 #define ICMP6_FILTER_WILLBLOCK(type, filterp) \
    120 	BIT_TEST((type), filterp)
    121 
    122 #define ICMP6_FILTER_SETPASS(type, filterp) \
    123 	BIT_CLEAR((type), filterp)
    124 
    125 #define ICMP6_FILTER_SETBLOCK(type, filterp) \
    126 	BIT_SET((type), filterp)
    127 
    128 #define ICMP6_FILTER_SETPASSALL(filterp) \
    129 	memset(filterp, 0, sizeof(struct icmp6_filter));
    130 
    131 #define ICMP6_FILTER_SETBLOCKALL(filterp) \
    132 	memset(filterp, 0xFF, sizeof(struct icmp6_filter));
    133 #endif
    134 
    135 #define	MAXPACKET	128000		/* max packet size */
    136 
    137 #ifdef SO_TIMESTAMP
    138 #define HAVE_SIN6_SCOPEID 1
    139 #endif
    140 
    141 #ifndef SCOPE_DELIMITER
    142 # define SCOPE_DELIMITER '%'
    143 #endif
    144 
    145 __u32 flowlabel;
    146 __u32 tclass;
    147 #ifdef ENABLE_PING6_RTHDR
    148 struct cmsghdr *srcrt;
    149 #endif
    150 
    151 struct sockaddr_in6 whereto;	/* who to ping */
    152 u_char outpack[MAXPACKET];
    153 int maxpacket = sizeof(outpack);
    154 
    155 static unsigned char cmsgbuf[4096];
    156 static int cmsglen = 0;
    157 
    158 static char * pr_addr(struct in6_addr *addr);
    159 static char * pr_addr_n(struct in6_addr *addr);
    160 static int pr_icmph(__u8 type, __u8 code, __u32 info);
    161 static void usage(void) __attribute((noreturn));
    162 
    163 struct sockaddr_in6 source;
    164 char *device;
    165 int pmtudisc=-1;
    166 
    167 static int icmp_sock;
    168 
    169 #ifdef USE_GNUTLS
    170 # include <gnutls/openssl.h>
    171 #else
    172 # include <openssl/md5.h>
    173 #endif
    174 
    175 /* Node Information query */
    176 int ni_query = -1;
    177 int ni_flag = 0;
    178 void *ni_subject = NULL;
    179 int ni_subject_len = 0;
    180 int ni_subject_type = -1;
    181 char *ni_group;
    182 
    183 static inline int ntohsp(__u16 *p)
    184 {
    185 	__u16 v;
    186 	memcpy(&v, p, sizeof(v));
    187 	return ntohs(v);
    188 }
    189 
    190 #if defined(ENABLE_PING6_RTHDR) && !defined(ENABLE_PING6_RTHDR_RFC3542)
    191 size_t inet6_srcrt_space(int type, int segments)
    192 {
    193 	if (type != 0 || segments > 24)
    194 		return 0;
    195 
    196 	return (sizeof(struct cmsghdr) + sizeof(struct ip6_rthdr0) +
    197 		segments * sizeof(struct in6_addr));
    198 }
    199 
    200 extern struct cmsghdr *	inet6_srcrt_init(void *bp, int type)
    201 {
    202 	struct cmsghdr *cmsg;
    203 
    204 	if (type)
    205 		return NULL;
    206 
    207 	memset(bp, 0, sizeof(struct cmsghdr) + sizeof(struct ip6_rthdr0));
    208 	cmsg = (struct cmsghdr *) bp;
    209 
    210 	cmsg->cmsg_len = sizeof(struct cmsghdr) + sizeof(struct ip6_rthdr0);
    211 	cmsg->cmsg_level = SOL_IPV6;
    212 	cmsg->cmsg_type = IPV6_RTHDR;
    213 
    214 	return cmsg;
    215 }
    216 
    217 int inet6_srcrt_add(struct cmsghdr *cmsg, const struct in6_addr *addr)
    218 {
    219 	struct ip6_rthdr0 *hdr;
    220 
    221 	hdr = (struct ip6_rthdr0 *) CMSG_DATA(cmsg);
    222 
    223 	cmsg->cmsg_len += sizeof(struct in6_addr);
    224 	hdr->ip6r0_len += sizeof(struct in6_addr) / 8;
    225 
    226 	memcpy(&hdr->ip6r0_addr[hdr->ip6r0_segleft++], addr,
    227 	       sizeof(struct in6_addr));
    228 
    229 	return 0;
    230 }
    231 #endif
    232 
    233 unsigned int if_name2index(const char *ifname)
    234 {
    235 	unsigned int i = if_nametoindex(ifname);
    236 	if (!i) {
    237 		fprintf(stderr, "ping: unknown iface %s\n", ifname);
    238 		exit(2);
    239 	}
    240 	return i;
    241 }
    242 
    243 struct niquery_option {
    244 	char *name;
    245 	int namelen;
    246 	int has_arg;
    247 	int data;
    248 	int (*handler)(int index, const char *arg);
    249 };
    250 
    251 #define NIQUERY_OPTION(_name, _has_arg, _data, _handler)	\
    252 	{							\
    253 		.name = _name,					\
    254 		.namelen = sizeof(_name) - 1,			\
    255 		.has_arg = _has_arg,				\
    256 		.data = _data,					\
    257 		.handler = _handler				\
    258 	}
    259 
    260 static int niquery_option_name_handler(int index, const char *arg);
    261 static int niquery_option_ipv6_handler(int index, const char *arg);
    262 static int niquery_option_ipv6_flag_handler(int index, const char *arg);
    263 static int niquery_option_ipv4_handler(int index, const char *arg);
    264 static int niquery_option_ipv4_flag_handler(int index, const char *arg);
    265 static int niquery_option_subject_addr_handler(int index, const char *arg);
    266 static int niquery_option_subject_name_handler(int index, const char *arg);
    267 static int niquery_option_help_handler(int index, const char *arg);
    268 
    269 struct niquery_option niquery_options[] = {
    270 	NIQUERY_OPTION("name",			0,	0,				niquery_option_name_handler),
    271 	NIQUERY_OPTION("fqdn",			0,	0,				niquery_option_name_handler),
    272 	NIQUERY_OPTION("ipv6",			0,	0,				niquery_option_ipv6_handler),
    273 	NIQUERY_OPTION("ipv6-all",		0,	NI_IPV6ADDR_F_ALL,		niquery_option_ipv6_flag_handler),
    274 	NIQUERY_OPTION("ipv6-compatible",	0,	NI_IPV6ADDR_F_COMPAT,		niquery_option_ipv6_flag_handler),
    275 	NIQUERY_OPTION("ipv6-linklocal",	0,	NI_IPV6ADDR_F_LINKLOCAL,	niquery_option_ipv6_flag_handler),
    276 	NIQUERY_OPTION("ipv6-sitelocal",	0,	NI_IPV6ADDR_F_SITELOCAL,	niquery_option_ipv6_flag_handler),
    277 	NIQUERY_OPTION("ipv6-global",		0,	NI_IPV6ADDR_F_GLOBAL,		niquery_option_ipv6_flag_handler),
    278 	NIQUERY_OPTION("ipv4",			0,	0,				niquery_option_ipv4_handler),
    279 	NIQUERY_OPTION("ipv4-all",		0,	NI_IPV4ADDR_F_ALL,		niquery_option_ipv4_flag_handler),
    280 	NIQUERY_OPTION("subject-ipv6",		1,	NI_SUBJ_IPV6,			niquery_option_subject_addr_handler),
    281 	NIQUERY_OPTION("subject-ipv4",		1,	NI_SUBJ_IPV4,			niquery_option_subject_addr_handler),
    282 	NIQUERY_OPTION("subject-name",		1,	0,				niquery_option_subject_name_handler),
    283 	NIQUERY_OPTION("subject-fqdn",		1,	-1,				niquery_option_subject_name_handler),
    284 	NIQUERY_OPTION("help",			0,	0,				niquery_option_help_handler),
    285 	{},
    286 };
    287 
    288 static inline int niquery_is_enabled(void)
    289 {
    290 	return ni_query >= 0;
    291 }
    292 
    293 #if PING6_NONCE_MEMORY
    294 __u8 *ni_nonce_ptr;
    295 #else
    296 struct {
    297 	struct timeval tv;
    298 	pid_t pid;
    299 } ni_nonce_secret;
    300 #endif
    301 
    302 static void niquery_init_nonce(void)
    303 {
    304 #if PING6_NONCE_MEMORY
    305 	struct timeval tv;
    306 	unsigned long seed;
    307 
    308 	seed = (unsigned long)getpid();
    309 	if (!gettimeofday(&tv, NULL))
    310 		seed ^= tv.tv_usec;
    311 	srand(seed);
    312 
    313 	ni_nonce_ptr = calloc(NI_NONCE_SIZE, MAX_DUP_CHK);
    314 	if (!ni_nonce_ptr) {
    315 		perror("ping6: calloc");
    316 		exit(2);
    317 	}
    318 
    319 	ni_nonce_ptr[0] = ~0;
    320 #else
    321 	gettimeofday(&ni_nonce_secret.tv, NULL);
    322 	ni_nonce_secret.pid = getpid();
    323 #endif
    324 }
    325 
    326 #if !PING6_NONCE_MEMORY
    327 static int niquery_nonce(__u8 *nonce, int fill)
    328 {
    329 	static __u8 digest[MD5_DIGEST_LENGTH];
    330 	static int seq = -1;
    331 
    332 	if (fill || seq != *(__u16 *)nonce || seq < 0) {
    333 		MD5_CTX ctxt;
    334 
    335 		MD5_Init(&ctxt);
    336 		MD5_Update(&ctxt, &ni_nonce_secret, sizeof(ni_nonce_secret));
    337 		MD5_Update(&ctxt, nonce, sizeof(__u16));
    338 		MD5_Final(digest, &ctxt);
    339 
    340 		seq = *(__u16 *)nonce;
    341 	}
    342 
    343 	if (fill) {
    344 		memcpy(nonce + sizeof(__u16), digest, NI_NONCE_SIZE - sizeof(__u16));
    345 		return 0;
    346 	} else {
    347 		if (memcmp(nonce + sizeof(__u16), digest, NI_NONCE_SIZE - sizeof(__u16)))
    348 			return -1;
    349 		return ntohsp((__u16 *)nonce);
    350 	}
    351 }
    352 #endif
    353 
    354 static inline void niquery_fill_nonce(__u16 seq, __u8 *nonce)
    355 {
    356 	__u16 v = htons(seq);
    357 #if PING6_NONCE_MEMORY
    358 	int i;
    359 
    360 	memcpy(&ni_nonce_ptr[NI_NONCE_SIZE * (seq % MAX_DUP_CHK)], &v, sizeof(v));
    361 
    362 	for (i = sizeof(v); i < NI_NONCE_SIZE; i++)
    363 		ni_nonce_ptr[NI_NONCE_SIZE * (seq % MAX_DUP_CHK) + i] = 0x100 * (rand() / (RAND_MAX + 1.0));
    364 
    365 	memcpy(nonce, &ni_nonce_ptr[NI_NONCE_SIZE * (seq % MAX_DUP_CHK)], NI_NONCE_SIZE);
    366 #else
    367 	memcpy(nonce, &v, sizeof(v));
    368 	niquery_nonce(nonce, 1);
    369 #endif
    370 }
    371 
    372 static inline int niquery_check_nonce(__u8 *nonce)
    373 {
    374 #if PING6_NONCE_MEMORY
    375 	__u16 seq = ntohsp((__u16 *)nonce);
    376 	if (memcmp(nonce, &ni_nonce_ptr[NI_NONCE_SIZE * (seq % MAX_DUP_CHK)], NI_NONCE_SIZE))
    377 		return -1;
    378 	return seq;
    379 #else
    380 	return niquery_nonce(nonce, 0);
    381 #endif
    382 }
    383 
    384 static int niquery_set_qtype(int type)
    385 {
    386 	if (niquery_is_enabled() && ni_query != type) {
    387 		printf("Qtype conflict\n");
    388 		return -1;
    389 	}
    390 	ni_query = type;
    391 	return 0;
    392 }
    393 
    394 static int niquery_option_name_handler(int index, const char *arg)
    395 {
    396 	if (niquery_set_qtype(NI_QTYPE_NAME) < 0)
    397 		return -1;
    398 	return 0;
    399 }
    400 
    401 static int niquery_option_ipv6_handler(int index, const char *arg)
    402 {
    403 	if (niquery_set_qtype(NI_QTYPE_IPV6ADDR) < 0)
    404 		return -1;
    405 	return 0;
    406 }
    407 
    408 static int niquery_option_ipv6_flag_handler(int index, const char *arg)
    409 {
    410 	if (niquery_set_qtype(NI_QTYPE_IPV6ADDR) < 0)
    411 		return -1;
    412 	ni_flag |= niquery_options[index].data;
    413 	return 0;
    414 }
    415 
    416 static int niquery_option_ipv4_handler(int index, const char *arg)
    417 {
    418 	if (niquery_set_qtype(NI_QTYPE_IPV4ADDR) < 0)
    419 		return -1;
    420 	return 0;
    421 }
    422 
    423 static int niquery_option_ipv4_flag_handler(int index, const char *arg)
    424 {
    425 	if (niquery_set_qtype(NI_QTYPE_IPV4ADDR) < 0)
    426 		return -1;
    427 	ni_flag |= niquery_options[index].data;
    428 	return 0;
    429 }
    430 
    431 static inline int niquery_is_subject_valid(void)
    432 {
    433 	return ni_subject_type >= 0 && ni_subject;
    434 }
    435 
    436 static int niquery_set_subject_type(int type)
    437 {
    438 	if (niquery_is_subject_valid() && ni_subject_type != type) {
    439 		printf("Subject type conflict\n");
    440 		return -1;
    441 	}
    442 	ni_subject_type = type;
    443 	return 0;
    444 }
    445 
    446 #define ARRAY_SIZE(array)	(sizeof(array) / sizeof(array[0]))
    447 #define OFFSET_OF(type,elem)	((size_t)&((type *)0)->elem)
    448 
    449 static int niquery_option_subject_addr_handler(int index, const char *arg)
    450 {
    451 	struct addrinfo hints, *ai0, *ai;
    452 	int offset;
    453 	int gai;
    454 
    455 	if (niquery_set_subject_type(niquery_options[index].data) < 0)
    456 		return -1;
    457 
    458 	ni_subject_type = niquery_options[index].data;
    459 
    460 	memset(&hints, 0, sizeof(hints));
    461 
    462 	switch (niquery_options[index].data) {
    463 	case NI_SUBJ_IPV6:
    464 		ni_subject_len = sizeof(struct in6_addr);
    465 		offset = OFFSET_OF(struct sockaddr_in6, sin6_addr);
    466 		hints.ai_family = AF_INET6;
    467 		break;
    468 	case NI_SUBJ_IPV4:
    469 		ni_subject_len = sizeof(struct in_addr);
    470 		offset = OFFSET_OF(struct sockaddr_in, sin_addr);
    471 		hints.ai_family = AF_INET;
    472 		break;
    473 	default:
    474 		/* should not happen. */
    475 		offset = -1;
    476 	}
    477 
    478 	hints.ai_socktype = SOCK_DGRAM;
    479 #ifdef USE_IDN
    480 	hints.ai_flags = AI_IDN;
    481 #endif
    482 
    483 	gai = getaddrinfo(arg, 0, &hints, &ai0);
    484 	if (gai) {
    485 		fprintf(stderr, "Unknown host: %s\n", arg);
    486 		return -1;
    487 	}
    488 
    489 	for (ai = ai0; ai; ai = ai->ai_next) {
    490 		void *p = malloc(ni_subject_len);
    491 		if (!p)
    492 			continue;
    493 		memcpy(p, (__u8 *)ai->ai_addr + offset, ni_subject_len);
    494 		free(ni_subject);
    495 		ni_subject = p;
    496 		break;
    497 	}
    498 	freeaddrinfo(ai0);
    499 
    500 	return 0;
    501 }
    502 
    503 static int niquery_option_subject_name_handler(int index, const char *arg)
    504 {
    505 	static char nigroup_buf[INET6_ADDRSTRLEN + 1 + IFNAMSIZ];
    506 	unsigned char *dnptrs[2], **dpp, **lastdnptr;
    507 	int n;
    508 	int i;
    509 	char *name, *p;
    510 	char *canonname = NULL, *idn = NULL;
    511 	unsigned char *buf = NULL;
    512 	size_t namelen;
    513 	size_t buflen;
    514 	int dots, fqdn = niquery_options[index].data;
    515 	MD5_CTX ctxt;
    516 	__u8 digest[MD5_DIGEST_LENGTH];
    517 #ifdef USE_IDN
    518 	int rc;
    519 #endif
    520 
    521 	if (niquery_set_subject_type(NI_SUBJ_NAME) < 0)
    522 		return -1;
    523 
    524 #ifdef USE_IDN
    525 	name = stringprep_locale_to_utf8(arg);
    526 	if (!name) {
    527 		fprintf(stderr, "ping6: IDN support failed.\n");
    528 		exit(2);
    529 	}
    530 #else
    531 	name = strdup(arg);
    532 	if (!name)
    533 		goto oomexit;
    534 #endif
    535 
    536 	p = strchr(name, SCOPE_DELIMITER);
    537 	if (p) {
    538 		*p = '\0';
    539 		if (strlen(p + 1) >= IFNAMSIZ) {
    540 			fprintf(stderr, "ping6: too long scope name.\n");
    541 			exit(1);
    542 		}
    543 	}
    544 
    545 #ifdef USE_IDN
    546 	rc = idna_to_ascii_8z(name, &idn, 0);
    547 	if (rc) {
    548 		fprintf(stderr, "ping6: IDN encoding error: %s\n",
    549 			idna_strerror(rc));
    550 		exit(2);
    551 	}
    552 #else
    553 	idn = strdup(name);
    554 	if (!idn)
    555 		goto oomexit;
    556 #endif
    557 
    558 	namelen = strlen(idn);
    559 	canonname = malloc(namelen + 1);
    560 	if (!canonname)
    561 		goto oomexit;
    562 
    563 	dots = 0;
    564 	for (i = 0; i < namelen + 1; i++) {
    565 		canonname[i] = isupper(idn[i]) ? tolower(idn[i]) : idn[i];
    566 		if (idn[i] == '.')
    567 			dots++;
    568 	}
    569 
    570 	if (fqdn == 0) {
    571 		/* guess if hostname is FQDN */
    572 		fqdn = dots ? 1 : -1;
    573 	}
    574 
    575 	buflen = namelen + 3 + 1;	/* dn_comp() requrires strlen() + 3,
    576 					   plus non-fqdn indicator. */
    577 	buf = malloc(buflen);
    578 	if (!buf) {
    579 		fprintf(stderr, "ping6: out of memory.\n");
    580 		goto errexit;
    581 	}
    582 
    583 	dpp = dnptrs;
    584 	lastdnptr = &dnptrs[ARRAY_SIZE(dnptrs)];
    585 
    586 	*dpp++ = (unsigned char *)buf;
    587 	*dpp++ = NULL;
    588 
    589 	n = dn_comp(canonname, (unsigned char *)buf, buflen, dnptrs, lastdnptr);
    590 	if (n < 0) {
    591 		fprintf(stderr, "ping6: Inappropriate subject name: %s\n", canonname);
    592 		goto errexit;
    593 	} else if (n >= buflen) {
    594 		fprintf(stderr, "ping6: dn_comp() returned too long result.\n");
    595 		goto errexit;
    596 	}
    597 
    598 	MD5_Init(&ctxt);
    599 	MD5_Update(&ctxt, buf, buf[0]);
    600 	MD5_Final(digest, &ctxt);
    601 
    602 	sprintf(nigroup_buf, "ff02::2:%02x%02x:%02x%02x%s%s",
    603 		digest[0], digest[1], digest[2], digest[3],
    604 		p ? "%" : "",
    605 		p ? p + 1 : "");
    606 
    607 	if (fqdn < 0)
    608 		buf[n] = 0;
    609 
    610 	free(ni_subject);
    611 
    612 	ni_group = nigroup_buf;
    613 	ni_subject = buf;
    614 	ni_subject_len = n + (fqdn < 0);
    615 	ni_group = nigroup_buf;
    616 
    617 	free(canonname);
    618 	free(idn);
    619 	free(name);
    620 
    621 	return 0;
    622 oomexit:
    623 	fprintf(stderr, "ping6: out of memory.\n");
    624 errexit:
    625 	free(buf);
    626 	free(canonname);
    627 	free(idn);
    628 	free(name);
    629 	exit(1);
    630 }
    631 
    632 int niquery_option_help_handler(int index, const char *arg)
    633 {
    634 	fprintf(stderr, "ping6 -N suboptions\n"
    635 			"\tHelp:\n"
    636 			"\t\thelp\n"
    637 			"\tQuery:\n"
    638 			"\t\tname,\n"
    639 			"\t\tipv6,ipv6-all,ipv6-compatible,ipv6-linklocal,ipv6-sitelocal,ipv6-global,\n"
    640 			"\t\tipv4,ipv4-all,\n"
    641 			"\tSubject:\n"
    642 			"\t\tsubject-ipv6=addr,subject-ipv4=addr,subject-name=name,subject-fqdn=name,\n"
    643 		);
    644 	exit(2);
    645 }
    646 
    647 int niquery_option_handler(const char *opt_arg)
    648 {
    649 	struct niquery_option *p;
    650 	int i;
    651 	int ret = -1;
    652 	for (i = 0, p = niquery_options; p->name; i++, p++) {
    653 		if (strncmp(p->name, opt_arg, p->namelen))
    654 			continue;
    655 		if (!p->has_arg) {
    656 			if (opt_arg[p->namelen] == '\0') {
    657 				ret = p->handler(i, NULL);
    658 				if (ret >= 0)
    659 					break;
    660 			}
    661 		} else {
    662 			if (opt_arg[p->namelen] == '=') {
    663 				ret = p->handler(i, &opt_arg[p->namelen] + 1);
    664 				if (ret >= 0)
    665 					break;
    666 			}
    667 		}
    668 	}
    669 	if (!p->name)
    670 		ret = niquery_option_help_handler(0, NULL);
    671 	return ret;
    672 }
    673 
    674 static int hextoui(const char *str)
    675 {
    676 	unsigned long val;
    677 	char *ep;
    678 
    679 	errno = 0;
    680 	val = strtoul(str, &ep, 16);
    681 	if (*ep) {
    682 		if (!errno)
    683 			errno = EINVAL;
    684 		return -1;
    685 	}
    686 
    687 	if (val > UINT_MAX) {
    688 		errno = ERANGE;
    689 		return UINT_MAX;
    690 	}
    691 
    692 	return val;
    693 }
    694 
    695 int main(int argc, char *argv[])
    696 {
    697 	int ch, hold, packlen;
    698 	u_char *packet;
    699 	char *target;
    700 	struct addrinfo hints, *ai;
    701 	int gai;
    702 	struct sockaddr_in6 firsthop;
    703 	int socket_errno = 0;
    704 	struct icmp6_filter filter;
    705 	int err;
    706 #ifdef __linux__
    707 	int csum_offset, sz_opt;
    708 #endif
    709 	static uint32_t scope_id = 0;
    710 
    711 #ifdef ANDROID
    712 	android_check_security();
    713 #endif
    714 
    715 	limit_capabilities();
    716 
    717 #ifdef USE_IDN
    718 	setlocale(LC_ALL, "");
    719 #endif
    720 
    721 	icmp_sock = socket(AF_INET6, SOCK_DGRAM, IPPROTO_ICMPV6);
    722 	if (icmp_sock < 0) {
    723 		enable_capability_raw();
    724 		icmp_sock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6);
    725 		socket_errno = errno;
    726 		disable_capability_raw();
    727 		using_ping_socket = 0;
    728 	}
    729 
    730 	source.sin6_family = AF_INET6;
    731 	memset(&firsthop, 0, sizeof(firsthop));
    732 	firsthop.sin6_family = AF_INET6;
    733 
    734 	preload = 1;
    735 	while ((ch = getopt(argc, argv, COMMON_OPTSTR "F:N:")) != EOF) {
    736 		switch(ch) {
    737 		case 'F':
    738 			flowlabel = hextoui(optarg);
    739 			if (errno || (flowlabel & ~IPV6_FLOWINFO_FLOWLABEL)) {
    740 				fprintf(stderr, "ping: Invalid flowinfo %s\n", optarg);
    741 				exit(2);
    742 			}
    743 			options |= F_FLOWINFO;
    744 			break;
    745 		case 'Q':
    746 			tclass = hextoui(optarg);
    747 			if (errno || (tclass & ~0xff)) {
    748 				fprintf(stderr, "ping: Invalid tclass %s\n", optarg);
    749 				exit(2);
    750 			}
    751 			options |= F_TCLASS;
    752 			break;
    753 		case 'I':
    754 			if (strchr(optarg, ':')) {
    755 				char *p, *addr = strdup(optarg);
    756 
    757 				if (!addr) {
    758 					fprintf(stderr, "ping: out of memory\n");
    759 					exit(2);
    760 				}
    761 
    762 				p = strchr(addr, SCOPE_DELIMITER);
    763 				if (p) {
    764 					*p = '\0';
    765 					device = optarg + (p - addr) + 1;
    766 				}
    767 
    768 				if (inet_pton(AF_INET6, addr, (char*)&source.sin6_addr) <= 0) {
    769 					fprintf(stderr, "ping: invalid source address %s\n", optarg);
    770 					exit(2);
    771 				}
    772 
    773 				options |= F_STRICTSOURCE;
    774 
    775 				free(addr);
    776 			} else {
    777 				device = optarg;
    778 			}
    779 			break;
    780 		case 'M':
    781 			if (strcmp(optarg, "do") == 0)
    782 				pmtudisc = IPV6_PMTUDISC_DO;
    783 			else if (strcmp(optarg, "dont") == 0)
    784 				pmtudisc = IPV6_PMTUDISC_DONT;
    785 			else if (strcmp(optarg, "want") == 0)
    786 				pmtudisc = IPV6_PMTUDISC_WANT;
    787 			else {
    788 				fprintf(stderr, "ping: wrong value for -M: do, dont, want are valid ones.\n");
    789 				exit(2);
    790 			}
    791 			break;
    792 		case 'V':
    793 			printf("ping6 utility, iputils-%s\n", SNAPSHOT);
    794 			exit(0);
    795 		case 'N':
    796 			if (using_ping_socket) {
    797 				fprintf(stderr, "ping: -N requires raw socket permissions\n");
    798 				exit(2);
    799 			}
    800 			if (niquery_option_handler(optarg) < 0) {
    801 				usage();
    802 				break;
    803 			}
    804 			break;
    805 		COMMON_OPTIONS
    806 			common_options(ch);
    807 			break;
    808 		default:
    809 			usage();
    810 		}
    811 	}
    812 	argc -= optind;
    813 	argv += optind;
    814 
    815 #ifdef ENABLE_PING6_RTHDR
    816 	while (argc > 1) {
    817 		struct in6_addr *addr;
    818 
    819 		if (srcrt == NULL) {
    820 			int space;
    821 
    822 			fprintf(stderr, "ping6: Warning: "
    823 					"Source routing is deprecated by RFC5095.\n");
    824 
    825 #ifdef ENABLE_PING6_RTHDR_RFC3542
    826 			space = inet6_rth_space(IPV6_RTHDR_TYPE_0, argc - 1);
    827 #else
    828 			space = inet6_srcrt_space(IPV6_SRCRT_TYPE_0, argc - 1);
    829 #endif
    830 			if (space == 0)	{
    831 				fprintf(stderr, "srcrt_space failed\n");
    832 				exit(2);
    833 			}
    834 #ifdef ENABLE_PING6_RTHDR_RFC3542
    835 			if (cmsglen + CMSG_SPACE(space) > sizeof(cmsgbuf)) {
    836 				fprintf(stderr, "no room for options\n");
    837 				exit(2);
    838 			}
    839 #else
    840 			if (space + cmsglen > sizeof(cmsgbuf)) {
    841 				fprintf(stderr, "no room for options\n");
    842 				exit(2);
    843 			}
    844 #endif
    845 			srcrt = (struct cmsghdr*)(cmsgbuf+cmsglen);
    846 #ifdef ENABLE_PING6_RTHDR_RFC3542
    847 			memset(srcrt, 0, CMSG_SPACE(0));
    848 			srcrt->cmsg_len = CMSG_LEN(space);
    849 			srcrt->cmsg_level = IPPROTO_IPV6;
    850 			srcrt->cmsg_type = IPV6_RTHDR;
    851 			inet6_rth_init(CMSG_DATA(srcrt), space, IPV6_RTHDR_TYPE_0, argc - 1);
    852 			cmsglen += CMSG_SPACE(space);
    853 #else
    854 			cmsglen += CMSG_ALIGN(space);
    855 			inet6_srcrt_init(srcrt, IPV6_SRCRT_TYPE_0);
    856 #endif
    857 		}
    858 
    859 		target = *argv;
    860 
    861 		memset(&hints, 0, sizeof(hints));
    862 		hints.ai_family = AF_INET6;
    863 #ifdef USE_IDN
    864 		hints.ai_flags = AI_IDN;
    865 #endif
    866 		gai = getaddrinfo(target, NULL, &hints, &ai);
    867 		if (gai) {
    868 			fprintf(stderr, "unknown host\n");
    869 			exit(2);
    870 		}
    871 		addr = &((struct sockaddr_in6 *)(ai->ai_addr))->sin6_addr;
    872 #ifdef ENABLE_PING6_RTHDR_RFC3542
    873 		inet6_rth_add(CMSG_DATA(srcrt), addr);
    874 #else
    875 		inet6_srcrt_add(srcrt, addr);
    876 #endif
    877 		if (IN6_IS_ADDR_UNSPECIFIED(&firsthop.sin6_addr)) {
    878 			memcpy(&firsthop.sin6_addr, addr, 16);
    879 #ifdef HAVE_SIN6_SCOPEID
    880 			firsthop.sin6_scope_id = ((struct sockaddr_in6 *)(ai->ai_addr))->sin6_scope_id;
    881 			/* Verify scope_id is the same as previous nodes */
    882 			if (firsthop.sin6_scope_id && scope_id && firsthop.sin6_scope_id != scope_id) {
    883 				fprintf(stderr, "scope discrepancy among the nodes\n");
    884 				exit(2);
    885 			} else if (!scope_id) {
    886 				scope_id = firsthop.sin6_scope_id;
    887 			}
    888 #endif
    889 		}
    890 		freeaddrinfo(ai);
    891 
    892 		argv++;
    893 		argc--;
    894 	}
    895 #endif
    896 
    897 	if (niquery_is_enabled()) {
    898 		niquery_init_nonce();
    899 
    900 		if (!niquery_is_subject_valid()) {
    901 			ni_subject = &whereto.sin6_addr;
    902 			ni_subject_len = sizeof(whereto.sin6_addr);
    903 			ni_subject_type = NI_SUBJ_IPV6;
    904 		}
    905 	}
    906 
    907 	if (argc > 1) {
    908 #ifndef ENABLE_PING6_RTHDR
    909 		fprintf(stderr, "ping6: Source routing is deprecated by RFC5095.\n");
    910 #endif
    911 		usage();
    912 	} else if (argc == 1) {
    913 		target = *argv;
    914 	} else {
    915 		if (ni_query < 0 && ni_subject_type != NI_SUBJ_NAME)
    916 			usage();
    917 		target = ni_group;
    918 	}
    919 
    920 	memset(&hints, 0, sizeof(hints));
    921 	hints.ai_family = AF_INET6;
    922 #ifdef USE_IDN
    923 	hints.ai_flags = AI_IDN;
    924 #endif
    925 	gai = getaddrinfo(target, NULL, &hints, &ai);
    926 	if (gai) {
    927 		fprintf(stderr, "unknown host\n");
    928 		exit(2);
    929 	}
    930 
    931 	memcpy(&whereto, ai->ai_addr, sizeof(whereto));
    932 	whereto.sin6_port = htons(IPPROTO_ICMPV6);
    933 
    934 	if (memchr(target, ':', strlen(target)))
    935 		options |= F_NUMERIC;
    936 
    937 	freeaddrinfo(ai);
    938 
    939 	if (IN6_IS_ADDR_UNSPECIFIED(&firsthop.sin6_addr)) {
    940 		memcpy(&firsthop.sin6_addr, &whereto.sin6_addr, 16);
    941 #ifdef HAVE_SIN6_SCOPEID
    942 		firsthop.sin6_scope_id = whereto.sin6_scope_id;
    943 		/* Verify scope_id is the same as intermediate nodes */
    944 		if (firsthop.sin6_scope_id && scope_id && firsthop.sin6_scope_id != scope_id) {
    945 			fprintf(stderr, "scope discrepancy among the nodes\n");
    946 			exit(2);
    947 		} else if (!scope_id) {
    948 			scope_id = firsthop.sin6_scope_id;
    949 		}
    950 #endif
    951 	}
    952 
    953 	hostname = target;
    954 
    955 	if (IN6_IS_ADDR_UNSPECIFIED(&source.sin6_addr)) {
    956 		socklen_t alen;
    957 		int probe_fd = socket(AF_INET6, SOCK_DGRAM, 0);
    958 
    959 		if (probe_fd < 0) {
    960 			perror("socket");
    961 			exit(2);
    962 		}
    963 		if (device) {
    964 #if defined(IPV6_RECVPKTINFO) || defined(HAVE_SIN6_SCOPEID)
    965 			unsigned int iface = if_name2index(device);
    966 #endif
    967 #ifdef IPV6_RECVPKTINFO
    968 			struct in6_pktinfo ipi;
    969 
    970 			memset(&ipi, 0, sizeof(ipi));
    971 			ipi.ipi6_ifindex = iface;
    972 #endif
    973 
    974 #ifdef HAVE_SIN6_SCOPEID
    975 			if (IN6_IS_ADDR_LINKLOCAL(&firsthop.sin6_addr) ||
    976 			    IN6_IS_ADDR_MC_LINKLOCAL(&firsthop.sin6_addr))
    977 				firsthop.sin6_scope_id = iface;
    978 #endif
    979 			enable_capability_raw();
    980 			if (
    981 #ifdef IPV6_RECVPKTINFO
    982 			    setsockopt(probe_fd, IPPROTO_IPV6, IPV6_PKTINFO, &ipi, sizeof(ipi)) == -1 &&
    983 #endif
    984 			    setsockopt(probe_fd, SOL_SOCKET, SO_BINDTODEVICE, device, strlen(device)+1) == -1) {
    985 				perror("setsockopt(SO_BINDTODEVICE)");
    986 				exit(2);
    987 			}
    988 			disable_capability_raw();
    989 		}
    990 		firsthop.sin6_port = htons(1025);
    991 
    992 		sock_setmark(probe_fd);
    993 
    994 		if (connect(probe_fd, (struct sockaddr*)&firsthop, sizeof(firsthop)) == -1) {
    995 			perror("connect");
    996 			exit(2);
    997 		}
    998 		alen = sizeof(source);
    999 		if (getsockname(probe_fd, (struct sockaddr*)&source, &alen) == -1) {
   1000 			perror("getsockname");
   1001 			exit(2);
   1002 		}
   1003 		source.sin6_port = 0;
   1004 		close(probe_fd);
   1005 
   1006 #ifndef WITHOUT_IFADDRS
   1007 		if (device) {
   1008 			struct ifaddrs *ifa0, *ifa;
   1009 
   1010 			if (getifaddrs(&ifa0)) {
   1011 				perror("getifaddrs");
   1012 				exit(2);
   1013 			}
   1014 
   1015 			for (ifa = ifa0; ifa; ifa = ifa->ifa_next) {
   1016 				if (!ifa->ifa_addr || ifa->ifa_addr->sa_family != AF_INET6)
   1017 					continue;
   1018 				if (!strncmp(ifa->ifa_name, device, sizeof(device) - 1) &&
   1019 				    IN6_ARE_ADDR_EQUAL(&((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr,
   1020 						       &source.sin6_addr))
   1021 					break;
   1022 			}
   1023 			if (!ifa)
   1024 				fprintf(stderr, "ping6: Warning: source address might be selected on device other than %s.\n", device);
   1025 
   1026 			freeifaddrs(ifa0);
   1027 		}
   1028 #endif
   1029 	}
   1030 #ifdef HAVE_SIN6_SCOPEID
   1031 	else if (device && (IN6_IS_ADDR_LINKLOCAL(&source.sin6_addr) ||
   1032 			    IN6_IS_ADDR_MC_LINKLOCAL(&source.sin6_addr)))
   1033 		source.sin6_scope_id = if_name2index(device);
   1034 #endif
   1035 
   1036 	if (icmp_sock < 0) {
   1037 		errno = socket_errno;
   1038 		perror("ping: icmp open socket");
   1039 		exit(2);
   1040 	}
   1041 
   1042 	if (device) {
   1043 		struct cmsghdr *cmsg;
   1044 		struct in6_pktinfo *ipi;
   1045 
   1046 		cmsg = (struct cmsghdr*)(cmsgbuf+cmsglen);
   1047 		cmsglen += CMSG_SPACE(sizeof(*ipi));
   1048 		cmsg->cmsg_len = CMSG_LEN(sizeof(*ipi));
   1049 		cmsg->cmsg_level = SOL_IPV6;
   1050 		cmsg->cmsg_type = IPV6_PKTINFO;
   1051 
   1052 		ipi = (struct in6_pktinfo*)CMSG_DATA(cmsg);
   1053 		memset(ipi, 0, sizeof(*ipi));
   1054 		ipi->ipi6_ifindex = if_name2index(device);
   1055 	}
   1056 
   1057 	if ((whereto.sin6_addr.s6_addr16[0]&htons(0xff00)) == htons (0xff00)) {
   1058 		if (uid) {
   1059 			if (interval < 1000) {
   1060 				fprintf(stderr, "ping: multicast ping with too short interval.\n");
   1061 				exit(2);
   1062 			}
   1063 			if (pmtudisc >= 0 && pmtudisc != IPV6_PMTUDISC_DO) {
   1064 				fprintf(stderr, "ping: multicast ping does not fragment.\n");
   1065 				exit(2);
   1066 			}
   1067 		}
   1068 		if (pmtudisc < 0)
   1069 			pmtudisc = IPV6_PMTUDISC_DO;
   1070 	}
   1071 
   1072 	if (pmtudisc >= 0) {
   1073 		if (setsockopt(icmp_sock, SOL_IPV6, IPV6_MTU_DISCOVER, &pmtudisc, sizeof(pmtudisc)) == -1) {
   1074 			perror("ping: IPV6_MTU_DISCOVER");
   1075 			exit(2);
   1076 		}
   1077 	}
   1078 
   1079 	if ((options&F_STRICTSOURCE) &&
   1080 	    bind(icmp_sock, (struct sockaddr*)&source, sizeof(source)) == -1) {
   1081 		perror("ping: bind icmp socket");
   1082 		exit(2);
   1083 	}
   1084 
   1085 	if (datalen >= sizeof(struct timeval) && (ni_query < 0)) {
   1086 		/* can we time transfer */
   1087 		timing = 1;
   1088 	}
   1089 	packlen = datalen + 8 + 4096 + 40 + 8; /* 4096 for rthdr */
   1090 	if (!(packet = (u_char *)malloc((u_int)packlen))) {
   1091 		fprintf(stderr, "ping: out of memory.\n");
   1092 		exit(2);
   1093 	}
   1094 
   1095 	working_recverr = 1;
   1096 	hold = 1;
   1097 	if (setsockopt(icmp_sock, SOL_IPV6, IPV6_RECVERR, (char *)&hold, sizeof(hold))) {
   1098 		fprintf(stderr, "WARNING: your kernel is veeery old. No problems.\n");
   1099 		working_recverr = 0;
   1100 	}
   1101 
   1102 	/* Estimate memory eaten by single packet. It is rough estimate.
   1103 	 * Actually, for small datalen's it depends on kernel side a lot. */
   1104 	hold = datalen+8;
   1105 	hold += ((hold+511)/512)*(40+16+64+160);
   1106 	sock_setbufs(icmp_sock, hold);
   1107 
   1108 	if (!using_ping_socket) {
   1109 #ifdef __linux__
   1110 		csum_offset = 2;
   1111 		sz_opt = sizeof(int);
   1112 
   1113 		err = setsockopt(icmp_sock, SOL_RAW, IPV6_CHECKSUM,
   1114 				 &csum_offset, sz_opt);
   1115 		if (err < 0) {
   1116 			/* checksum should be enabled by default and setting
   1117 			 * this option might fail anyway.
   1118 			 */
   1119 			fprintf(stderr, "setsockopt(RAW_CHECKSUM) failed"
   1120 				" - try to continue.");
   1121 		}
   1122 #endif
   1123 
   1124 		/*
   1125 		 *	select icmp echo reply as icmp type to receive
   1126 		 */
   1127 
   1128 		ICMP6_FILTER_SETBLOCKALL(&filter);
   1129 
   1130 		if (!working_recverr) {
   1131 			ICMP6_FILTER_SETPASS(ICMP6_DST_UNREACH, &filter);
   1132 			ICMP6_FILTER_SETPASS(ICMP6_PACKET_TOO_BIG, &filter);
   1133 			ICMP6_FILTER_SETPASS(ICMP6_TIME_EXCEEDED, &filter);
   1134 			ICMP6_FILTER_SETPASS(ICMP6_PARAM_PROB, &filter);
   1135 		}
   1136 
   1137 		if (niquery_is_enabled())
   1138 			ICMP6_FILTER_SETPASS(ICMPV6_NI_REPLY, &filter);
   1139 		else
   1140 			ICMP6_FILTER_SETPASS(ICMP6_ECHO_REPLY, &filter);
   1141 
   1142 		err = setsockopt(icmp_sock, IPPROTO_ICMPV6, ICMP6_FILTER,
   1143 				 &filter, sizeof(struct icmp6_filter));
   1144 
   1145 		if (err < 0) {
   1146 			perror("setsockopt(ICMP6_FILTER)");
   1147 			exit(2);
   1148 		}
   1149 	}
   1150 
   1151 	if (options & F_NOLOOP) {
   1152 		int loop = 0;
   1153 		if (setsockopt(icmp_sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP,
   1154 				&loop, sizeof(loop)) == -1) {
   1155 			perror ("can't disable multicast loopback");
   1156 			exit(2);
   1157 		}
   1158 	}
   1159 	if (options & F_TTL) {
   1160 		if (setsockopt(icmp_sock, IPPROTO_IPV6, IPV6_MULTICAST_HOPS,
   1161 			       &ttl, sizeof(ttl)) == -1) {
   1162 			perror ("can't set multicast hop limit");
   1163 			exit(2);
   1164 		}
   1165 		if (setsockopt(icmp_sock, IPPROTO_IPV6, IPV6_UNICAST_HOPS,
   1166 			       &ttl, sizeof(ttl)) == -1) {
   1167 			perror ("can't set unicast hop limit");
   1168 			exit(2);
   1169 		}
   1170 	}
   1171 
   1172 	if (1) {
   1173 		int on = 1;
   1174 		if (
   1175 #ifdef IPV6_RECVHOPLIMIT
   1176 		    setsockopt(icmp_sock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT,
   1177 			       &on, sizeof(on)) == -1 &&
   1178 		    setsockopt(icmp_sock, IPPROTO_IPV6, IPV6_2292HOPLIMIT,
   1179 			       &on, sizeof(on)) == -1
   1180 #else
   1181 		    setsockopt(icmp_sock, IPPROTO_IPV6, IPV6_HOPLIMIT,
   1182 			       &on, sizeof(on)) == -1
   1183 #endif
   1184 		   ){
   1185 			perror ("can't receive hop limit");
   1186 			exit(2);
   1187 		}
   1188 	}
   1189 
   1190 	if (options & F_TCLASS) {
   1191 #ifdef IPV6_TCLASS
   1192 		if (setsockopt(icmp_sock, IPPROTO_IPV6, IPV6_TCLASS,
   1193 			       &tclass, sizeof(tclass)) == -1) {
   1194 			perror ("setsockopt(IPV6_TCLASS)");
   1195 			exit(2);
   1196 		}
   1197 #else
   1198 		fprintf(stderr, "Traffic class is not supported.\n");
   1199 #endif
   1200 	}
   1201 
   1202 	if (options&F_FLOWINFO) {
   1203 #ifdef IPV6_FLOWINFO_SEND
   1204 		int on = 1;
   1205 #endif
   1206 #ifdef IPV6_FLOWLABEL_MGR
   1207 		char freq_buf[CMSG_ALIGN(sizeof(struct in6_flowlabel_req)) + cmsglen];
   1208 		struct in6_flowlabel_req *freq = (struct in6_flowlabel_req *)freq_buf;
   1209 		int freq_len = sizeof(*freq);
   1210 #ifdef ENABLE_PING6_RTHDR
   1211 		if (srcrt)
   1212 			freq_len = CMSG_ALIGN(sizeof(*freq)) + srcrt->cmsg_len;
   1213 #endif
   1214 		memset(freq, 0, sizeof(*freq));
   1215 		freq->flr_label = htonl(flowlabel & IPV6_FLOWINFO_FLOWLABEL);
   1216 		freq->flr_action = IPV6_FL_A_GET;
   1217 		freq->flr_flags = IPV6_FL_F_CREATE;
   1218 		freq->flr_share = IPV6_FL_S_EXCL;
   1219 		memcpy(&freq->flr_dst, &whereto.sin6_addr, 16);
   1220 #ifdef ENABLE_PING6_RTHDR
   1221 		if (srcrt)
   1222 			memcpy(freq_buf + CMSG_ALIGN(sizeof(*freq)), srcrt, srcrt->cmsg_len);
   1223 #endif
   1224 		if (setsockopt(icmp_sock, IPPROTO_IPV6, IPV6_FLOWLABEL_MGR,
   1225 			       freq, freq_len) == -1) {
   1226 			perror ("can't set flowlabel");
   1227 			exit(2);
   1228 		}
   1229 		flowlabel = freq->flr_label;
   1230 #ifdef ENABLE_PING6_RTHDR
   1231 		if (srcrt) {
   1232 			cmsglen = (char*)srcrt - (char*)cmsgbuf;
   1233 			srcrt = NULL;
   1234 		}
   1235 #endif
   1236 #else
   1237 		fprintf(stderr, "Flow labels are not supported.\n");
   1238 		exit(2);
   1239 #endif
   1240 
   1241 #ifdef IPV6_FLOWINFO_SEND
   1242 		whereto.sin6_flowinfo = flowlabel;
   1243 		if (setsockopt(icmp_sock, IPPROTO_IPV6, IPV6_FLOWINFO_SEND,
   1244 			       &on, sizeof(on)) == -1) {
   1245 			perror ("can't send flowinfo");
   1246 			exit(2);
   1247 		}
   1248 #else
   1249 		fprintf(stderr, "Flowinfo is not supported.\n");
   1250 		exit(2);
   1251 #endif
   1252 	}
   1253 
   1254 	printf("PING %s(%s) ", hostname, pr_addr(&whereto.sin6_addr));
   1255 	if (flowlabel)
   1256 		printf(", flow 0x%05x, ", (unsigned)ntohl(flowlabel));
   1257 	if (device || (options&F_STRICTSOURCE)) {
   1258 		printf("from %s %s: ",
   1259 		       pr_addr_n(&source.sin6_addr), device ? : "");
   1260 	}
   1261 	printf("%d data bytes\n", datalen);
   1262 
   1263 	setup(icmp_sock);
   1264 
   1265 	drop_capabilities();
   1266 
   1267 	main_loop(icmp_sock, packet, packlen);
   1268 }
   1269 
   1270 int receive_error_msg()
   1271 {
   1272 	int res;
   1273 	char cbuf[512];
   1274 	struct iovec  iov;
   1275 	struct msghdr msg;
   1276 	struct cmsghdr *cmsg;
   1277 	struct sock_extended_err *e;
   1278 	struct icmp6_hdr icmph;
   1279 	struct sockaddr_in6 target;
   1280 	int net_errors = 0;
   1281 	int local_errors = 0;
   1282 	int saved_errno = errno;
   1283 
   1284 	iov.iov_base = &icmph;
   1285 	iov.iov_len = sizeof(icmph);
   1286 	msg.msg_name = (void*)&target;
   1287 	msg.msg_namelen = sizeof(target);
   1288 	msg.msg_iov = &iov;
   1289 	msg.msg_iovlen = 1;
   1290 	msg.msg_flags = 0;
   1291 	msg.msg_control = cbuf;
   1292 	msg.msg_controllen = sizeof(cbuf);
   1293 
   1294 	res = recvmsg(icmp_sock, &msg, MSG_ERRQUEUE|MSG_DONTWAIT);
   1295 	if (res < 0)
   1296 		goto out;
   1297 
   1298 	e = NULL;
   1299 	for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
   1300 		if (cmsg->cmsg_level == SOL_IPV6) {
   1301 			if (cmsg->cmsg_type == IPV6_RECVERR)
   1302 				e = (struct sock_extended_err *)CMSG_DATA(cmsg);
   1303 		}
   1304 	}
   1305 	if (e == NULL)
   1306 		abort();
   1307 
   1308 	if (e->ee_origin == SO_EE_ORIGIN_LOCAL) {
   1309 		local_errors++;
   1310 		if (options & F_QUIET)
   1311 			goto out;
   1312 		if (options & F_FLOOD)
   1313 			write_stdout("E", 1);
   1314 		else if (e->ee_errno != EMSGSIZE)
   1315 			fprintf(stderr, "ping: local error: %s\n", strerror(e->ee_errno));
   1316 		else
   1317 			fprintf(stderr, "ping: local error: Message too long, mtu=%u\n", e->ee_info);
   1318 		nerrors++;
   1319 	} else if (e->ee_origin == SO_EE_ORIGIN_ICMP6) {
   1320 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6*)(e+1);
   1321 
   1322 		if (res < sizeof(icmph) ||
   1323 		    memcmp(&target.sin6_addr, &whereto.sin6_addr, 16) ||
   1324 		    icmph.icmp6_type != ICMP6_ECHO_REQUEST ||
   1325 		    !is_ours(icmph.icmp6_id)) {
   1326 			/* Not our error, not an error at all. Clear. */
   1327 			saved_errno = 0;
   1328 			goto out;
   1329 		}
   1330 
   1331 		net_errors++;
   1332 		nerrors++;
   1333 		if (options & F_QUIET)
   1334 			goto out;
   1335 		if (options & F_FLOOD) {
   1336 			write_stdout("\bE", 2);
   1337 		} else {
   1338 			print_timestamp();
   1339 			printf("From %s icmp_seq=%u ", pr_addr(&sin6->sin6_addr), ntohs(icmph.icmp6_seq));
   1340 			pr_icmph(e->ee_type, e->ee_code, e->ee_info);
   1341 			putchar('\n');
   1342 			fflush(stdout);
   1343 		}
   1344 	}
   1345 
   1346 out:
   1347 	errno = saved_errno;
   1348 	return net_errors ? : -local_errors;
   1349 }
   1350 
   1351 /*
   1352  * pinger --
   1353  * 	Compose and transmit an ICMP ECHO REQUEST packet.  The IP packet
   1354  * will be added on by the kernel.  The ID field is our UNIX process ID,
   1355  * and the sequence number is an ascending integer.  The first 8 bytes
   1356  * of the data portion are used to hold a UNIX "timeval" struct in VAX
   1357  * byte-order, to compute the round-trip time.
   1358  */
   1359 int build_echo(__u8 *_icmph)
   1360 {
   1361 	struct icmp6_hdr *icmph;
   1362 	int cc;
   1363 
   1364 	icmph = (struct icmp6_hdr *)_icmph;
   1365 	icmph->icmp6_type = ICMP6_ECHO_REQUEST;
   1366 	icmph->icmp6_code = 0;
   1367 	icmph->icmp6_cksum = 0;
   1368 	icmph->icmp6_seq = htons(ntransmitted+1);
   1369 	icmph->icmp6_id = ident;
   1370 
   1371 	if (timing)
   1372 		gettimeofday((struct timeval *)&outpack[8],
   1373 		    (struct timezone *)NULL);
   1374 
   1375 	cc = datalen + 8;			/* skips ICMP portion */
   1376 
   1377 	return cc;
   1378 }
   1379 
   1380 
   1381 int build_niquery(__u8 *_nih)
   1382 {
   1383 	struct ni_hdr *nih;
   1384 	int cc;
   1385 
   1386 	nih = (struct ni_hdr *)_nih;
   1387 	nih->ni_cksum = 0;
   1388 
   1389 	nih->ni_type = ICMPV6_NI_QUERY;
   1390 	cc = sizeof(*nih);
   1391 	datalen = 0;
   1392 
   1393 	niquery_fill_nonce(ntransmitted + 1, nih->ni_nonce);
   1394 	nih->ni_code = ni_subject_type;
   1395 	nih->ni_qtype = htons(ni_query);
   1396 	nih->ni_flags = ni_flag;
   1397 	memcpy(nih + 1, ni_subject, ni_subject_len);
   1398 	cc += ni_subject_len;
   1399 
   1400 	return cc;
   1401 }
   1402 
   1403 int send_probe(void)
   1404 {
   1405 	int len, cc;
   1406 
   1407 	rcvd_clear(ntransmitted + 1);
   1408 
   1409 	if (niquery_is_enabled())
   1410 		len = build_niquery(outpack);
   1411 	else
   1412 		len = build_echo(outpack);
   1413 
   1414 	if (cmsglen == 0) {
   1415 		cc = sendto(icmp_sock, (char *)outpack, len, confirm,
   1416 			    (struct sockaddr *) &whereto,
   1417 			    sizeof(struct sockaddr_in6));
   1418 	} else {
   1419 		struct msghdr mhdr;
   1420 		struct iovec iov;
   1421 
   1422 		iov.iov_len  = len;
   1423 		iov.iov_base = outpack;
   1424 
   1425 		memset(&mhdr, 0, sizeof(mhdr));
   1426 		mhdr.msg_name = &whereto;
   1427 		mhdr.msg_namelen = sizeof(struct sockaddr_in6);
   1428 		mhdr.msg_iov = &iov;
   1429 		mhdr.msg_iovlen = 1;
   1430 		mhdr.msg_control = cmsgbuf;
   1431 		mhdr.msg_controllen = cmsglen;
   1432 
   1433 		cc = sendmsg(icmp_sock, &mhdr, confirm);
   1434 	}
   1435 	confirm = 0;
   1436 
   1437 	return (cc == len ? 0 : cc);
   1438 }
   1439 
   1440 void pr_echo_reply(__u8 *_icmph, int cc)
   1441 {
   1442 	struct icmp6_hdr *icmph = (struct icmp6_hdr *) _icmph;
   1443 	printf(" icmp_seq=%u", ntohs(icmph->icmp6_seq));
   1444 };
   1445 
   1446 static void putchar_safe(char c)
   1447 {
   1448 	if (isprint(c))
   1449 		putchar(c);
   1450 	else
   1451 		printf("\\%03o", c);
   1452 }
   1453 
   1454 void pr_niquery_reply_name(struct ni_hdr *nih, int len)
   1455 {
   1456 	__u8 *h = (__u8 *)(nih + 1);
   1457 	__u8 *p = h + 4;
   1458 	__u8 *end = (__u8 *)nih + len;
   1459 	int continued = 0;
   1460 	char buf[1024];
   1461 	int ret;
   1462 
   1463 	len -= sizeof(struct ni_hdr) + 4;
   1464 
   1465 	if (len < 0) {
   1466 		printf(" parse error (too short)");
   1467 		return;
   1468 	}
   1469 	while (p < end) {
   1470 		int fqdn = 1;
   1471 		int i;
   1472 
   1473 		memset(buf, 0xff, sizeof(buf));
   1474 
   1475 		if (continued)
   1476 			putchar(',');
   1477 
   1478 		ret = dn_expand(h, end, p, buf, sizeof(buf));
   1479 		if (ret < 0) {
   1480 			printf(" parse error (truncated)");
   1481 			break;
   1482 		}
   1483 		if (p + ret < end && *(p + ret) == '\0')
   1484 			fqdn = 0;
   1485 
   1486 		putchar(' ');
   1487 		for (i = 0; i < strlen(buf); i++)
   1488 			putchar_safe(buf[i]);
   1489 		if (fqdn)
   1490 			putchar('.');
   1491 
   1492 		p += ret + !fqdn;
   1493 
   1494 		continued = 1;
   1495 	}
   1496 }
   1497 
   1498 void pr_niquery_reply_addr(struct ni_hdr *nih, int len)
   1499 {
   1500 	__u8 *h = (__u8 *)(nih + 1);
   1501 	__u8 *p = h + 4;
   1502 	__u8 *end = (__u8 *)nih + len;
   1503 	int af;
   1504 	int aflen;
   1505 	int continued = 0;
   1506 	int truncated;
   1507 	char buf[1024];
   1508 
   1509 	switch (ntohs(nih->ni_qtype)) {
   1510 	case NI_QTYPE_IPV4ADDR:
   1511 		af = AF_INET;
   1512 		aflen = sizeof(struct in_addr);
   1513 		truncated = nih->ni_flags & NI_IPV6ADDR_F_TRUNCATE;
   1514 		break;
   1515 	case NI_QTYPE_IPV6ADDR:
   1516 		af = AF_INET6;
   1517 		aflen = sizeof(struct in6_addr);
   1518 		truncated = nih->ni_flags & NI_IPV4ADDR_F_TRUNCATE;
   1519 		break;
   1520 	default:
   1521 		/* should not happen */
   1522 		af = aflen = truncated = 0;
   1523 	}
   1524 	p = h;
   1525 	if (len < 0) {
   1526 		printf(" parse error (too short)");
   1527 		return;
   1528 	}
   1529 
   1530 	while (p < end) {
   1531 		if (continued)
   1532 			putchar(',');
   1533 
   1534 		if (p + sizeof(__u32) + aflen > end) {
   1535 			printf(" parse error (truncated)");
   1536 			break;
   1537 		}
   1538 		if (!inet_ntop(af, p + sizeof(__u32), buf, sizeof(buf)))
   1539 			printf(" unexpeced error in inet_ntop(%s)",
   1540 			       strerror(errno));
   1541 		else
   1542 			printf(" %s", buf);
   1543 		p += sizeof(__u32) + aflen;
   1544 
   1545 		continued = 1;
   1546 	}
   1547 	if (truncated)
   1548 		printf(" (truncated)");
   1549 }
   1550 
   1551 void pr_niquery_reply(__u8 *_nih, int len)
   1552 {
   1553 	struct ni_hdr *nih = (struct ni_hdr *)_nih;
   1554 
   1555 	switch (nih->ni_code) {
   1556 	case NI_SUCCESS:
   1557 		switch (ntohs(nih->ni_qtype)) {
   1558 		case NI_QTYPE_NAME:
   1559 			pr_niquery_reply_name(nih, len);
   1560 			break;
   1561 		case NI_QTYPE_IPV4ADDR:
   1562 		case NI_QTYPE_IPV6ADDR:
   1563 			pr_niquery_reply_addr(nih, len);
   1564 			break;
   1565 		default:
   1566 			printf(" unknown qtype(0x%02x)", ntohs(nih->ni_qtype));
   1567 		}
   1568 		break;
   1569 	case NI_REFUSED:
   1570 		printf(" refused");
   1571 		break;
   1572 	case NI_UNKNOWN:
   1573 		printf(" unknown");
   1574 		break;
   1575 	default:
   1576 		printf(" unknown code(%02x)", ntohs(nih->ni_code));
   1577 	}
   1578 	printf("; seq=%u;", ntohsp((__u16*)nih->ni_nonce));
   1579 }
   1580 
   1581 /*
   1582  * parse_reply --
   1583  *	Print out the packet, if it came from us.  This logic is necessary
   1584  * because ALL readers of the ICMP socket get a copy of ALL ICMP packets
   1585  * which arrive ('tis only fair).  This permits multiple copies of this
   1586  * program to be run without having intermingled output (or statistics!).
   1587  */
   1588 int
   1589 parse_reply(struct msghdr *msg, int cc, void *addr, struct timeval *tv)
   1590 {
   1591 	struct sockaddr_in6 *from = addr;
   1592 	__u8 *buf = msg->msg_iov->iov_base;
   1593 	struct cmsghdr *c;
   1594 	struct icmp6_hdr *icmph;
   1595 	int hops = -1;
   1596 
   1597 	for (c = CMSG_FIRSTHDR(msg); c; c = CMSG_NXTHDR(msg, c)) {
   1598 		if (c->cmsg_level != SOL_IPV6)
   1599 			continue;
   1600 		switch(c->cmsg_type) {
   1601 		case IPV6_HOPLIMIT:
   1602 #ifdef IPV6_2292HOPLIMIT
   1603 		case IPV6_2292HOPLIMIT:
   1604 #endif
   1605 			if (c->cmsg_len < CMSG_LEN(sizeof(int)))
   1606 				continue;
   1607 			memcpy(&hops, CMSG_DATA(c), sizeof(hops));
   1608 		}
   1609 	}
   1610 
   1611 
   1612 	/* Now the ICMP part */
   1613 
   1614 	icmph = (struct icmp6_hdr *) buf;
   1615 	if (cc < 8) {
   1616 		if (options & F_VERBOSE)
   1617 			fprintf(stderr, "ping: packet too short (%d bytes)\n", cc);
   1618 		return 1;
   1619 	}
   1620 
   1621 	if (icmph->icmp6_type == ICMP6_ECHO_REPLY) {
   1622 		if (!is_ours(icmph->icmp6_id))
   1623 			return 1;
   1624 		if (gather_statistics((__u8*)icmph, sizeof(*icmph), cc,
   1625 				      ntohs(icmph->icmp6_seq),
   1626 				      hops, 0, tv, pr_addr(&from->sin6_addr),
   1627 				      pr_echo_reply))
   1628 			return 0;
   1629 	} else if (icmph->icmp6_type == ICMPV6_NI_REPLY) {
   1630 		struct ni_hdr *nih = (struct ni_hdr *)icmph;
   1631 		int seq = niquery_check_nonce(nih->ni_nonce);
   1632 		if (seq < 0)
   1633 			return 1;
   1634 		if (gather_statistics((__u8*)icmph, sizeof(*icmph), cc,
   1635 				      seq,
   1636 				      hops, 0, tv, pr_addr(&from->sin6_addr),
   1637 				      pr_niquery_reply))
   1638 			return 0;
   1639 	} else {
   1640 		int nexthdr;
   1641 		struct ip6_hdr *iph1 = (struct ip6_hdr*)(icmph+1);
   1642 		struct icmp6_hdr *icmph1 = (struct icmp6_hdr *)(iph1+1);
   1643 
   1644 		/* We must not ever fall here. All the messages but
   1645 		 * echo reply are blocked by filter and error are
   1646 		 * received with IPV6_RECVERR. Ugly code is preserved
   1647 		 * however, just to remember what crap we avoided
   1648 		 * using RECVRERR. :-)
   1649 		 */
   1650 
   1651 		if (cc < 8+sizeof(struct ip6_hdr)+8)
   1652 			return 1;
   1653 
   1654 		if (memcmp(&iph1->ip6_dst, &whereto.sin6_addr, 16))
   1655 			return 1;
   1656 
   1657 		nexthdr = iph1->ip6_nxt;
   1658 
   1659 		if (nexthdr == 44) {
   1660 			nexthdr = *(__u8*)icmph1;
   1661 			icmph1++;
   1662 		}
   1663 		if (nexthdr == IPPROTO_ICMPV6) {
   1664 			if (icmph1->icmp6_type != ICMP6_ECHO_REQUEST ||
   1665 			    !is_ours(icmph1->icmp6_id))
   1666 				return 1;
   1667 			acknowledge(ntohs(icmph1->icmp6_seq));
   1668 			if (working_recverr)
   1669 				return 0;
   1670 			nerrors++;
   1671 			if (options & F_FLOOD) {
   1672 				write_stdout("\bE", 2);
   1673 				return 0;
   1674 			}
   1675 			print_timestamp();
   1676 			printf("From %s: icmp_seq=%u ", pr_addr(&from->sin6_addr), ntohs(icmph1->icmp6_seq));
   1677 		} else {
   1678 			/* We've got something other than an ECHOREPLY */
   1679 			if (!(options & F_VERBOSE) || uid)
   1680 				return 1;
   1681 			print_timestamp();
   1682 			printf("From %s: ", pr_addr(&from->sin6_addr));
   1683 		}
   1684 		pr_icmph(icmph->icmp6_type, icmph->icmp6_code, ntohl(icmph->icmp6_mtu));
   1685 	}
   1686 
   1687 	if (!(options & F_FLOOD)) {
   1688 		if (options & F_AUDIBLE)
   1689 			putchar('\a');
   1690 		putchar('\n');
   1691 		fflush(stdout);
   1692 	} else {
   1693 		putchar('\a');
   1694 		fflush(stdout);
   1695 	}
   1696 	return 0;
   1697 }
   1698 
   1699 
   1700 int pr_icmph(__u8 type, __u8 code, __u32 info)
   1701 {
   1702 	switch(type) {
   1703 	case ICMP6_DST_UNREACH:
   1704 		printf("Destination unreachable: ");
   1705 		switch (code) {
   1706 		case ICMP6_DST_UNREACH_NOROUTE:
   1707 			printf("No route");
   1708 			break;
   1709 		case ICMP6_DST_UNREACH_ADMIN:
   1710 			printf("Administratively prohibited");
   1711 			break;
   1712 		case ICMP6_DST_UNREACH_BEYONDSCOPE:
   1713 			printf("Beyond scope of source address");
   1714 			break;
   1715 		case ICMP6_DST_UNREACH_ADDR:
   1716 			printf("Address unreachable");
   1717 			break;
   1718 		case ICMP6_DST_UNREACH_NOPORT:
   1719 			printf("Port unreachable");
   1720 			break;
   1721 		default:
   1722 			printf("Unknown code %d", code);
   1723 			break;
   1724 		}
   1725 		break;
   1726 	case ICMP6_PACKET_TOO_BIG:
   1727 		printf("Packet too big: mtu=%u", info);
   1728 		if (code)
   1729 			printf(", code=%d", code);
   1730 		break;
   1731 	case ICMP6_TIME_EXCEEDED:
   1732 		printf("Time exceeded: ");
   1733 		if (code == ICMP6_TIME_EXCEED_TRANSIT)
   1734 			printf("Hop limit");
   1735 		else if (code == ICMP6_TIME_EXCEED_REASSEMBLY)
   1736 			printf("Defragmentation failure");
   1737 		else
   1738 			printf("code %d", code);
   1739 		break;
   1740 	case ICMP6_PARAM_PROB:
   1741 		printf("Parameter problem: ");
   1742 		if (code == ICMP6_PARAMPROB_HEADER)
   1743 			printf("Wrong header field ");
   1744 		else if (code == ICMP6_PARAMPROB_NEXTHEADER)
   1745 			printf("Unknown header ");
   1746 		else if (code == ICMP6_PARAMPROB_OPTION)
   1747 			printf("Unknown option ");
   1748 		else
   1749 			printf("code %d ", code);
   1750 		printf ("at %u", info);
   1751 		break;
   1752 	case ICMP6_ECHO_REQUEST:
   1753 		printf("Echo request");
   1754 		break;
   1755 	case ICMP6_ECHO_REPLY:
   1756 		printf("Echo reply");
   1757 		break;
   1758 	case MLD_LISTENER_QUERY:
   1759 		printf("MLD Query");
   1760 		break;
   1761 	case MLD_LISTENER_REPORT:
   1762 		printf("MLD Report");
   1763 		break;
   1764 	case MLD_LISTENER_REDUCTION:
   1765 		printf("MLD Reduction");
   1766 		break;
   1767 	default:
   1768 		printf("unknown icmp type: %u", type);
   1769 
   1770 	}
   1771 	return 0;
   1772 }
   1773 
   1774 #include <linux/filter.h>
   1775 
   1776 void install_filter(void)
   1777 {
   1778 	static int once;
   1779 	static struct sock_filter insns[] = {
   1780 		BPF_STMT(BPF_LD|BPF_H|BPF_ABS, 4),  /* Load icmp echo ident */
   1781 		BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0xAAAA, 0, 1),  /* Ours? */
   1782 		BPF_STMT(BPF_RET|BPF_K, ~0U),  /* Yes, it passes. */
   1783 		BPF_STMT(BPF_LD|BPF_B|BPF_ABS, 0),  /* Load icmp type */
   1784 		BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, ICMP6_ECHO_REPLY, 1, 0), /* Echo? */
   1785 		BPF_STMT(BPF_RET|BPF_K, ~0U), /* No. It passes. This must not happen. */
   1786 		BPF_STMT(BPF_RET|BPF_K, 0), /* Echo with wrong ident. Reject. */
   1787 	};
   1788 	static struct sock_fprog filter = {
   1789 		sizeof insns / sizeof(insns[0]),
   1790 		insns
   1791 	};
   1792 
   1793 	if (once)
   1794 		return;
   1795 	once = 1;
   1796 
   1797 	/* Patch bpflet for current identifier. */
   1798 	insns[1] = (struct sock_filter)BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, htons(ident), 0, 1);
   1799 
   1800 	if (setsockopt(icmp_sock, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter)))
   1801 		perror("WARNING: failed to install socket filter\n");
   1802 }
   1803 
   1804 
   1805 /*
   1806  * pr_addr --
   1807  *	Return an ascii host address as a dotted quad and optionally with
   1808  * a hostname.
   1809  */
   1810 char * pr_addr(struct in6_addr *addr)
   1811 {
   1812 	struct hostent *hp = NULL;
   1813 	static char *s;
   1814 
   1815 #ifdef USE_IDN
   1816 	free(s);
   1817 #endif
   1818 
   1819 	in_pr_addr = !setjmp(pr_addr_jmp);
   1820 
   1821 	if (!(exiting || options&F_NUMERIC))
   1822 		hp = gethostbyaddr((__u8*)addr, sizeof(struct in6_addr), AF_INET6);
   1823 
   1824 	in_pr_addr = 0;
   1825 
   1826 	if (!hp
   1827 #ifdef USE_IDN
   1828 	    || idna_to_unicode_lzlz(hp->h_name, &s, 0) != IDNA_SUCCESS
   1829 #endif
   1830 	    )
   1831 		s = NULL;
   1832 
   1833 	return hp ? (s ? s : hp->h_name) : pr_addr_n(addr);
   1834 }
   1835 
   1836 char * pr_addr_n(struct in6_addr *addr)
   1837 {
   1838 	static char str[64];
   1839 	inet_ntop(AF_INET6, addr, str, sizeof(str));
   1840 	return str;
   1841 }
   1842 
   1843 #define USAGE_NEWLINE	"\n            "
   1844 
   1845 void usage(void)
   1846 {
   1847 	fprintf(stderr,
   1848 		"Usage: ping6"
   1849 		" [-"
   1850 			"aAbBdDfhLnOqrRUvV"
   1851 		"]"
   1852 		" [-c count]"
   1853 		" [-i interval]"
   1854 		" [-I interface]"
   1855 		USAGE_NEWLINE
   1856 		" [-l preload]"
   1857 		" [-m mark]"
   1858 		" [-M pmtudisc_option]"
   1859 		USAGE_NEWLINE
   1860 		" [-N nodeinfo_option]"
   1861 		" [-p pattern]"
   1862 		" [-Q tclass]"
   1863 		" [-s packetsize]"
   1864 		USAGE_NEWLINE
   1865 		" [-S sndbuf]"
   1866 		" [-t ttl]"
   1867 		" [-T timestamp_option]"
   1868 		" [-w deadline]"
   1869 		USAGE_NEWLINE
   1870 		" [-W timeout]"
   1871 #ifdef ENABLE_PING6_RTHDR
   1872 		" [hop1 ...]"
   1873 #endif
   1874 		" destination"
   1875 		"\n"
   1876 	);
   1877 	exit(2);
   1878 }
   1879