Home | History | Annotate | Download | only in traceroute
      1 /*
      2  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
      3  * Use is subject to license terms.
      4  */
      5 
      6 /*
      7  * Copyright (c) 1988, 1989, 1991, 1994, 1995, 1996, 1997
      8  *	The Regents of the University of California.  All rights reserved.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that: (1) source code distributions
     12  * retain the above copyright notice and this paragraph in its entirety, (2)
     13  * distributions including binary code include the above copyright notice and
     14  * this paragraph in its entirety in the documentation or other materials
     15  * provided with the distribution, and (3) all advertising materials mentioning
     16  * features or use of this software display the following acknowledgement:
     17  * ``This product includes software developed by the University of California,
     18  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
     19  * the University nor the names of its contributors may be used to endorse
     20  * or promote products derived from this software without specific prior
     21  * written permission.
     22  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
     23  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
     24  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
     25  *
     26  *
     27  * @(#)$Header: traceroute.c,v 1.49 97/06/13 02:30:23 leres Exp $ (LBL)
     28  */
     29 
     30 #include <sys/param.h>
     31 #include <sys/file.h>
     32 #include <sys/ioctl.h>
     33 #include <sys/socket.h>
     34 #include <sys/time.h>
     35 #include <sys/sysmacros.h>
     36 
     37 #include <netinet/in_systm.h>
     38 #include <netinet/in.h>
     39 #include <netinet/ip.h>
     40 #include <netinet/ip_var.h>
     41 #include <netinet/ip_icmp.h>
     42 #include <netinet/udp.h>
     43 #include <netinet/udp_var.h>
     44 #include <netinet/ip6.h>
     45 #include <netinet/icmp6.h>
     46 
     47 #include <arpa/inet.h>
     48 
     49 #include <ctype.h>
     50 #include <errno.h>
     51 #include <malloc.h>
     52 #include <memory.h>
     53 #include <netdb.h>
     54 #include <stdio.h>
     55 #include <stdlib.h>
     56 #include <strings.h>
     57 #include <unistd.h>
     58 #include <libintl.h>
     59 #include <locale.h>
     60 #include <signal.h>
     61 #include <setjmp.h>
     62 #include <limits.h>
     63 #include <zone.h>
     64 
     65 #include <priv_utils.h>
     66 
     67 #include <libinetutil.h>
     68 #include "traceroute.h"
     69 
     70 #define	MAX_SEQ			65535	/* max sequence value for ICMP */
     71 #define	MAX_TRAFFIC_CLASS	255	/* max traffic class for IPv6 */
     72 #define	MAX_FLOW_LABEL		0xFFFFF	/* max flow label for IPv6 */
     73 #define	MAX_TOS			255	/* max type-of-service for IPv4 */
     74 #define	STR_LEN			30
     75 
     76 /* store the information about a host */
     77 struct hostinfo {
     78 	char *name;		/* hostname */
     79 	int family;		/* address family of the IP addresses */
     80 	int num_addr;			/* number of IP addresses */
     81 	union any_in_addr *addrs;	/* list of IP addresses */
     82 };
     83 
     84 /* used to store a bunch of protocol specific values */
     85 struct pr_set {
     86 	int family;		/* AF_INET or AF_INET6 */
     87 	char name[STR_LEN];	/* "IPv4" or "IPv6" */
     88 	char icmp[STR_LEN];	/* "icmp" or "ipv6-icmp" */
     89 	int icmp_minlen;
     90 	int addr_len;
     91 	int ip_hdr_len;
     92 	int packlen;
     93 	int sock_size;		/* size of sockaddr_in or sockaddr_in6 */
     94 	struct sockaddr *to;
     95 	struct sockaddr *from;
     96 	void *from_sin_addr;
     97 	union any_in_addr *gwIPlist;
     98 	/* pointers to v4/v6 functions */
     99 	struct ip *(*set_buffers_fn) (int);
    100 	int (*check_reply_fn)(struct msghdr *, int, int, uchar_t *, uchar_t *);
    101 	boolean_t (*print_icmp_other_fn)(uchar_t, uchar_t);
    102 	void (*print_addr_fn)(uchar_t *, int, struct sockaddr *);
    103 
    104 };
    105 
    106 /*
    107  * LBNL bug fixed: in LBNL traceroute 'uchar_t packet[512];'
    108  * Not sufficient to hold the complete packet for ECHO REPLY of a big probe.
    109  * Packet size is reported incorrectly in such a case.
    110  * Also this buffer needs to be 32 bit aligned. In the future the alignment
    111  * requirement will be increased to 64 bit. So, let's use 64 bit alignment now.
    112  */
    113 static uint64_t packet[(IP_MAXPACKET + 1)/8];	/* received packet */
    114 
    115 static struct ip *outip4;	/* output buffer to send as an IPv4 datagram */
    116 static struct ip *outip6;	/* output buffer to send as an IPv6 datagram */
    117 
    118 /* Used to store the ancillary data that comes with the received packets */
    119 static uint64_t ancillary_data[(IP_MAXPACKET + 1)/8];
    120 
    121 /* first get the gw names, later you'll resolve them based on the family */
    122 static char *gwlist[MAXMAX_GWS];		/* gateway names list */
    123 static union any_in_addr gwIPlist[MAX_GWS];	/* gateway IPv4 address list */
    124 static union any_in_addr gwIP6list[MAX_GWS6];	/* gateway IPv6 address list */
    125 
    126 static int family_input = AF_UNSPEC;	/* User supplied protocol family */
    127 static int rcvsock4;		/* receive (icmp) socket file descriptor */
    128 static int sndsock4;		/* send (udp/icmp) socket file descriptor */
    129 static int rcvsock6;		/* receive (icmp6) socket file descriptor */
    130 static int sndsock6;		/* send (udp6/icmp6) socket file descriptor */
    131 int gw_count = 0;		/* number of gateways */
    132 static struct sockaddr_in whereto;	/* Who to try to reach */
    133 static struct sockaddr_in6 whereto6;
    134 static struct sockaddr_in wherefrom;	/* Who we are */
    135 static struct sockaddr_in6 wherefrom6;
    136 static int packlen_input = 0;		/* user input for packlen */
    137 
    138 char *prog;
    139 static char *source_input = NULL; /* this is user arg. source, doesn't change */
    140 static char *source = NULL;	/* this gets modified after name lookup */
    141 char *hostname;
    142 static char *device = NULL;   	/* interface name */
    143 static struct pr_set *pr4;	/* protocol info for IPv4 */
    144 static struct pr_set *pr6;	/* protocol info for IPv6 */
    145 static struct ifaddrlist *al4;	/* list of interfaces */
    146 static struct ifaddrlist *al6;	/* list of interfaces */
    147 static uint_t if_index = 0;	/* interface index */
    148 static int num_v4 = 0;		/* count of IPv4 addresses */
    149 static int num_v6 = 0;		/* count of IPv6 addresses */
    150 static int num_ifs4 = 0;	/* count of local IPv4 interfaces */
    151 static int num_ifs6 = 0;	/* count of local IPv6 interfaces */
    152 
    153 static int nprobes = 3;		/* number of probes */
    154 static int max_ttl = 30;	/* max number of hops */
    155 static int first_ttl = 1;	/* initial number of hops */
    156 ushort_t ident;			/* used to authenticate replies */
    157 ushort_t port = 32768 + 666;	/* start udp dest port # for probe packets */
    158 
    159 static int options = 0;		/* socket options */
    160 boolean_t verbose = _B_FALSE;	/* verbose output */
    161 static int waittime = 5;	/* time to wait for response (in seconds) */
    162 static struct timeval delay = {0, 0}; /* delay between consecutive probe */
    163 boolean_t nflag = _B_FALSE;	/* print addresses numerically */
    164 static boolean_t showttl = _B_FALSE; /* print the ttl(hop limit) of recvd pkt */
    165 boolean_t useicmp = _B_FALSE;  	/* use icmp echo instead of udp packets */
    166 boolean_t docksum = _B_TRUE;	/* calculate checksums */
    167 static boolean_t collect_stat = _B_FALSE;	/* print statistics */
    168 boolean_t settos = _B_FALSE;   	/* set type-of-service field */
    169 int dontfrag = 0;		/* IP*_DONTFRAG */
    170 static int max_timeout = 5;	/* quit after this consecutive timeouts */
    171 static boolean_t probe_all = _B_FALSE;	/* probe all the IFs of the target */
    172 static boolean_t pick_src = _B_FALSE;	/* traceroute picks the src address */
    173 
    174 /*
    175  * flow and class are specific to IPv6, tos and off are specific to IPv4.
    176  * Each protocol uses the ones that are specific to itself, and ignores
    177  * others.
    178  */
    179 static uint_t flow = 0;		/* IPv6 flow info */
    180 static uint_t class = 0;	/* IPv6 class */
    181 uchar_t tos = 0;		/* IPv4 type-of-service */
    182 ushort_t off = 0;		/* set DF bit */
    183 
    184 static jmp_buf env;		/* stack environment for longjmp() */
    185 boolean_t raw_req;		/* if sndsock for IPv4 must be raw */
    186 
    187 /* Forwards */
    188 static uint_t calc_packetlen(int, struct pr_set *);
    189 extern int check_reply(struct msghdr *, int, int, uchar_t *, uchar_t *);
    190 extern int check_reply6(struct msghdr *, int, int, uchar_t *, uchar_t *);
    191 static double deltaT(struct timeval *, struct timeval *);
    192 static char *device_name(struct ifaddrlist *, int, union any_in_addr *,
    193     struct pr_set *);
    194 extern void *find_ancillary_data(struct msghdr *, int, int);
    195 static boolean_t has_addr(struct addrinfo *, union any_in_addr *);
    196 static struct ifaddrlist *find_device(struct ifaddrlist *, int, char *);
    197 static struct ifaddrlist *find_ifaddr(struct ifaddrlist *, int,
    198     union any_in_addr *, int);
    199 static void get_gwaddrs(char **, int, union any_in_addr *,
    200     union any_in_addr *, int *, int *);
    201 static void get_hostinfo(char *, int, struct addrinfo **);
    202 char *inet_name(union any_in_addr *, int);
    203 ushort_t in_cksum(ushort_t *, int);
    204 extern int ip_hdr_length_v6(ip6_t *, int, uint8_t *);
    205 extern char *pr_type(uchar_t);
    206 extern char *pr_type6(uchar_t);
    207 extern void print_addr(uchar_t *, int, struct sockaddr *);
    208 extern void print_addr6(uchar_t *, int, struct sockaddr *);
    209 extern boolean_t print_icmp_other(uchar_t, uchar_t);
    210 extern boolean_t print_icmp_other6(uchar_t, uchar_t);
    211 static void print_stats(int, int, double, double, double, double);
    212 static void print_unknown_host_msg(const char *, const char *);
    213 static void record_stats(double, int *, double *, double *, double *, double *);
    214 static void resolve_nodes(int *, struct addrinfo **);
    215 static void select_src_addr(union any_in_addr *, union any_in_addr *, int);
    216 extern void send_probe(int, struct sockaddr *, struct ip *, int, int,
    217     struct timeval *, int);
    218 extern void send_probe6(int, struct msghdr *, struct ip *, int, int,
    219     struct timeval *, int);
    220 extern void set_ancillary_data(struct msghdr *, int, union any_in_addr *, int,
    221     uint_t);
    222 extern struct ip *set_buffers(int);
    223 extern struct ip *set_buffers6(int);
    224 extern void set_IPv4opt_sourcerouting(int, union any_in_addr *,
    225     union any_in_addr *);
    226 static void set_sin(struct sockaddr *, union any_in_addr *, int);
    227 static int set_src_addr(struct pr_set *, struct ifaddrlist **);
    228 static void setup_protocol(struct pr_set *, int);
    229 static void setup_socket(struct pr_set *, int);
    230 static void sig_handler(int);
    231 static int str2int(const char *, const char *, int, int);
    232 static double str2dbl(const char *, const char *, double, double);
    233 static void trace_it(struct addrinfo *);
    234 static void traceroute(union any_in_addr *, struct msghdr *, struct pr_set *,
    235     int, struct ifaddrlist *);
    236 static void tv_sub(struct timeval *, struct timeval *);
    237 static void usage(void);
    238 static int wait_for_reply(int, struct msghdr *, struct timeval *);
    239 static double xsqrt(double);
    240 
    241 /*
    242  * main
    243  */
    244 int
    245 main(int argc, char **argv)
    246 {
    247 	struct addrinfo *ai_dst = NULL;		/* destination host */
    248 	/*
    249 	 * "probing_successful" indicates if we could successfully send probes,
    250 	 * not necessarily received reply from the target (this behavior is from
    251 	 * the original traceroute). It's _B_FALSE if packlen is invalid, or no
    252 	 * interfaces found.
    253 	 */
    254 	boolean_t probing_successful = _B_FALSE;
    255 	int longjmp_return;			/* return value from longjump */
    256 	int i = 0;
    257 	char *cp;
    258 	int op;
    259 	char *ep;
    260 	char temp_buf[INET6_ADDRSTRLEN];	/* use for inet_ntop() */
    261 	double pause;
    262 
    263 	/*
    264 	 * A raw socket will be used for IPv4 if there is sufficient
    265 	 * privilege.
    266 	 */
    267 	raw_req = priv_ineffect(PRIV_NET_RAWACCESS);
    268 
    269 	/*
    270 	 * We'll need the privilege only when we open the sockets; that's
    271 	 * when we'll fail if the program has insufficient privileges.
    272 	 */
    273 	(void) __init_suid_priv(PU_CLEARLIMITSET, PRIV_NET_ICMPACCESS,
    274 	    raw_req ? PRIV_NET_RAWACCESS : NULL, NULL);
    275 
    276 	(void) setlinebuf(stdout);
    277 
    278 	if ((cp = strrchr(argv[0], '/')) != NULL)
    279 		prog = cp + 1;
    280 	else
    281 		prog = argv[0];
    282 
    283 	opterr = 0;
    284 	while ((op = getopt(argc, argv, "adFIlnrSvxA:c:f:g:i:L:m:P:p:Q:q:s:"
    285 	    "t:w:")) != EOF) {
    286 		switch (op) {
    287 		case 'A':
    288 			if (strcmp(optarg, "inet") == 0) {
    289 				family_input = AF_INET;
    290 			} else if (strcmp(optarg, "inet6") == 0) {
    291 				family_input = AF_INET6;
    292 			} else {
    293 				Fprintf(stderr,
    294 				    "%s: unknown address family %s\n",
    295 				    prog, optarg);
    296 				exit(EXIT_FAILURE);
    297 			}
    298 			break;
    299 
    300 		case 'a':
    301 			probe_all = _B_TRUE;
    302 			break;
    303 
    304 		case 'c':
    305 			class = str2int(optarg, "traffic class", 0,
    306 			    MAX_TRAFFIC_CLASS);
    307 			break;
    308 
    309 		case 'd':
    310 			options |= SO_DEBUG;
    311 			break;
    312 
    313 		case 'f':
    314 			first_ttl = str2int(optarg, "first ttl", 1, MAXTTL);
    315 			break;
    316 
    317 		case 'F':
    318 			off = IP_DF;
    319 			dontfrag = 1;
    320 			break;
    321 
    322 		case 'g':
    323 			if (!raw_req) {
    324 				Fprintf(stderr,
    325 				    "%s: privilege to specify a loose source "
    326 				    "route gateway is unavailable\n",
    327 				    prog);
    328 				exit(EXIT_FAILURE);
    329 			}
    330 			if (gw_count >= MAXMAX_GWS) {
    331 				Fprintf(stderr,
    332 				    "%s: Too many gateways\n", prog);
    333 				exit(EXIT_FAILURE);
    334 			}
    335 			gwlist[gw_count] = strdup(optarg);
    336 			if (gwlist[gw_count] == NULL) {
    337 				Fprintf(stderr, "%s: strdup %s\n", prog,
    338 				    strerror(errno));
    339 				exit(EXIT_FAILURE);
    340 			}
    341 
    342 			++gw_count;
    343 			break;
    344 
    345 		case 'l':
    346 			showttl = _B_TRUE;
    347 			break;
    348 
    349 		case 'i':
    350 			/* this can be IF name or IF index */
    351 			if_index = (uint_t)strtol(optarg, &ep, 10);
    352 
    353 			/* convert IF index <-->  IF name */
    354 			if (errno != 0 || *ep != '\0') {
    355 				device = optarg;
    356 				if_index = if_nametoindex((const char *)device);
    357 
    358 				/*
    359 				 * In case it fails, check to see if the problem
    360 				 * is other than "IF not found".
    361 				 */
    362 				if (if_index == 0 && errno != ENXIO) {
    363 					Fprintf(stderr, "%s: if_nametoindex:"
    364 					    "%s\n", prog, strerror(errno));
    365 					exit(EXIT_FAILURE);
    366 				}
    367 			} else {
    368 				device = (char *)malloc(LIFNAMSIZ + 1);
    369 				if (device == NULL) {
    370 					Fprintf(stderr, "%s: malloc: %s\n",
    371 					    prog, strerror(errno));
    372 					exit(EXIT_FAILURE);
    373 				}
    374 
    375 				device = if_indextoname(if_index, device);
    376 				if (device != NULL) {
    377 					device[LIFNAMSIZ] = '\0';
    378 				} else if (errno != ENXIO) {
    379 					/*
    380 					 * The problem was other than "index
    381 					 * not found".
    382 					 */
    383 					Fprintf(stderr, "%s: if_indextoname:"
    384 					    "%s\n", prog, strerror(errno));
    385 					exit(EXIT_FAILURE);
    386 				}
    387 			}
    388 
    389 			if (device == NULL || if_index == 0) {
    390 				Fprintf(stderr, "%s: interface %s "
    391 				    "doesn't match any actual interfaces\n",
    392 				    prog, optarg);
    393 				exit(EXIT_FAILURE);
    394 			}
    395 			break;
    396 
    397 		case 'I':
    398 			useicmp = _B_TRUE;
    399 			break;
    400 
    401 		case 'L':
    402 			flow = str2int(optarg, "flow label", 0, MAX_FLOW_LABEL);
    403 			break;
    404 
    405 		case 'm':
    406 			max_ttl = str2int(optarg, "max ttl(hop limit)", 1,
    407 			    MAXTTL);
    408 			break;
    409 
    410 		case 'n':
    411 			nflag = _B_TRUE;
    412 			break;
    413 
    414 		case 'P':
    415 			pause = str2dbl(optarg, "pause", 0, INT_MAX);
    416 			delay.tv_sec = (time_t)pause;
    417 			delay.tv_usec = (suseconds_t)((pause - delay.tv_sec) *
    418 			    1000000);
    419 			break;
    420 
    421 		case 'p':
    422 			port = str2int(optarg, "port", 1, MAX_PORT);
    423 			break;
    424 
    425 		case 'Q':
    426 			max_timeout = str2int(optarg, "max timeout", 1, -1);
    427 			break;
    428 
    429 		case 'q':
    430 			nprobes = str2int(optarg, "nprobes", 1, -1);
    431 			break;
    432 
    433 		case 'r':
    434 			options |= SO_DONTROUTE;
    435 			break;
    436 
    437 		case 'S':
    438 			collect_stat = _B_TRUE;
    439 			break;
    440 
    441 		case 's':
    442 			/*
    443 			 * set the ip source address of the outbound
    444 			 * probe (e.g., on a multi-homed host).
    445 			 */
    446 			source_input = optarg;
    447 			break;
    448 
    449 		case 't':
    450 			tos = (uchar_t)str2int(optarg, "tos", 0, MAX_TOS);
    451 			settos = _B_TRUE;
    452 			break;
    453 
    454 		case 'v':
    455 			verbose = _B_TRUE;
    456 			break;
    457 
    458 		case 'x':
    459 			docksum = _B_FALSE;
    460 			break;
    461 
    462 		case 'w':
    463 			waittime = str2int(optarg, "wait time", 2, -1);
    464 			break;
    465 
    466 		default:
    467 			usage();
    468 			break;
    469 		}
    470 	}
    471 
    472 	/*
    473 	 * If it's probe_all, SIGQUIT makes traceroute exit(). But we set the
    474 	 * address to jump back to in traceroute(). Until then, we'll need to
    475 	 * temporarily specify one.
    476 	 */
    477 	if (probe_all) {
    478 		if ((longjmp_return = setjmp(env)) != 0) {
    479 			if (longjmp_return == SIGQUIT) {
    480 				Printf("(exiting)\n");
    481 				exit(EXIT_SUCCESS);
    482 			} else {		/* should never happen */
    483 				exit(EXIT_FAILURE);
    484 			}
    485 		}
    486 		(void) signal(SIGQUIT, sig_handler);
    487 	}
    488 
    489 	if ((gw_count > 0) && (options & SO_DONTROUTE)) {
    490 		Fprintf(stderr, "%s: loose source route gateways (-g)"
    491 		    " cannot be specified when probe packets are sent"
    492 		    " directly to a host on an attached network (-r)\n",
    493 		    prog);
    494 		exit(EXIT_FAILURE);
    495 	}
    496 
    497 	i = argc - optind;
    498 	if (i == 1 || i == 2) {
    499 		hostname = argv[optind];
    500 
    501 		if (i == 2) {
    502 			/* accept any length now, we'll check it later */
    503 			packlen_input = str2int(argv[optind + 1],
    504 			    "packet length", 0, -1);
    505 		}
    506 	} else {
    507 		usage();
    508 	}
    509 
    510 	if (first_ttl > max_ttl) {
    511 		Fprintf(stderr,
    512 		    "%s: first ttl(hop limit) (%d) may not be greater"
    513 		    " than max ttl(hop limit) (%d)\n",
    514 		    prog, first_ttl, max_ttl);
    515 		exit(EXIT_FAILURE);
    516 	}
    517 
    518 	/* resolve hostnames */
    519 	resolve_nodes(&family_input, &ai_dst);
    520 	if (ai_dst == NULL) {
    521 		exit(EXIT_FAILURE);
    522 	}
    523 
    524 	/*
    525 	 * If it's probe_all, SIGINT makes traceroute skip to probing next IP
    526 	 * address of the target. The new interrupt handler is assigned in
    527 	 * traceroute() function. Until then let's ignore the signal.
    528 	 */
    529 	if (probe_all)
    530 		(void) signal(SIGINT, SIG_IGN);
    531 
    532 	ident = (getpid() & 0xffff) | 0x8000;
    533 
    534 	/*
    535 	 * We KNOW that probe_all == TRUE if family is AF_UNSPEC,
    536 	 * since family is set to the specific AF found unless it's
    537 	 * probe_all. So if family == AF_UNSPEC, we need to init pr4 and pr6.
    538 	 */
    539 	switch (family_input) {
    540 	case AF_UNSPEC:
    541 		pr4 = (struct pr_set *)malloc(sizeof (struct pr_set));
    542 		if (pr4 == NULL) {
    543 			Fprintf(stderr,
    544 			    "%s: malloc %s\n", prog, strerror(errno));
    545 			exit(EXIT_FAILURE);
    546 		}
    547 		pr6 = (struct pr_set *)malloc(sizeof (struct pr_set));
    548 		if (pr6 == NULL) {
    549 			Fprintf(stderr,
    550 			    "%s: malloc %s\n", prog, strerror(errno));
    551 			exit(EXIT_FAILURE);
    552 		}
    553 		setup_protocol(pr6, AF_INET6);
    554 		setup_protocol(pr4, AF_INET);
    555 		outip6 = (*pr6->set_buffers_fn)(pr6->packlen);
    556 		setup_socket(pr6, pr6->packlen);
    557 
    558 		outip4 = (*pr4->set_buffers_fn)(pr4->packlen);
    559 		setup_socket(pr4, pr4->packlen);
    560 		num_ifs6 = set_src_addr(pr6, &al6);
    561 		num_ifs4 = set_src_addr(pr4, &al4);
    562 		break;
    563 	case AF_INET6:
    564 		pr6 = (struct pr_set *)malloc(sizeof (struct pr_set));
    565 		if (pr6 == NULL) {
    566 			Fprintf(stderr,
    567 			    "%s: malloc %s\n", prog, strerror(errno));
    568 			exit(EXIT_FAILURE);
    569 		}
    570 		setup_protocol(pr6, AF_INET6);
    571 		outip6 = (*pr6->set_buffers_fn)(pr6->packlen);
    572 		setup_socket(pr6, pr6->packlen);
    573 		num_ifs6 = set_src_addr(pr6, &al6);
    574 		break;
    575 	case AF_INET:
    576 		pr4 = (struct pr_set *)malloc(sizeof (struct pr_set));
    577 		if (pr4 == NULL) {
    578 			Fprintf(stderr,
    579 			    "%s: malloc %s\n", prog, strerror(errno));
    580 			exit(EXIT_FAILURE);
    581 		}
    582 		setup_protocol(pr4, AF_INET);
    583 		outip4 = (*pr4->set_buffers_fn)(pr4->packlen);
    584 		setup_socket(pr4, pr4->packlen);
    585 		num_ifs4 = set_src_addr(pr4, &al4);
    586 		break;
    587 	default:
    588 		Fprintf(stderr, "%s: unknow address family.\n", prog);
    589 		exit(EXIT_FAILURE);
    590 	}
    591 
    592 	if (num_v4 + num_v6 > 1 && !probe_all) {
    593 		if (ai_dst->ai_family == AF_INET) {
    594 			Fprintf(stderr,
    595 			    "%s: Warning: %s has multiple addresses;"
    596 			    " using %s\n", prog, hostname,
    597 			    inet_ntop(AF_INET,
    598 			    /* LINTED E_BAD_PTR_CAST_ALIGN */
    599 			    (void *)&((struct sockaddr_in *)
    600 			    ai_dst->ai_addr)->sin_addr,
    601 			    temp_buf, sizeof (temp_buf)));
    602 		} else {
    603 			Fprintf(stderr,
    604 			    "%s: Warning: %s has multiple addresses;"
    605 			    " using %s\n", prog, hostname,
    606 			    inet_ntop(AF_INET6,
    607 			    /* LINTED E_BAD_PTR_CAST_ALIGN */
    608 			    (void *)&((struct sockaddr_in6 *)
    609 			    ai_dst->ai_addr)->sin6_addr,
    610 			    temp_buf, sizeof (temp_buf)));
    611 		}
    612 	}
    613 
    614 	if (num_ifs4 + num_ifs6 > 0) {
    615 		trace_it(ai_dst);
    616 		probing_successful = _B_TRUE;
    617 	}
    618 
    619 	(void) close(rcvsock4);
    620 	(void) close(sndsock4);
    621 	(void) close(rcvsock6);
    622 	(void) close(sndsock6);
    623 
    624 	/*
    625 	 * if we could probe any of the IP addresses of the target, that means
    626 	 * this was a successful operation
    627 	 */
    628 	if (probing_successful)
    629 		return (EXIT_SUCCESS);
    630 	else
    631 		return (EXIT_FAILURE);
    632 }
    633 
    634 /*
    635  * print "unknown host" message
    636  */
    637 static void
    638 print_unknown_host_msg(const char *protocol, const char *host)
    639 {
    640 	Fprintf(stderr, "%s: unknown%s host %s\n", prog, protocol, host);
    641 }
    642 
    643 /*
    644  * resolve destination host and gateways
    645  */
    646 static void
    647 resolve_nodes(int *family, struct addrinfo **ai_dstp)
    648 {
    649 	struct addrinfo *ai_dst = NULL;
    650 	struct addrinfo *aip = NULL;
    651 	int num_resolved_gw = 0;
    652 	int num_resolved_gw6 = 0;
    653 
    654 	get_hostinfo(hostname, *family, &ai_dst);
    655 	if (ai_dst == NULL) {
    656 		print_unknown_host_msg("", hostname);
    657 		exit(EXIT_FAILURE);
    658 	}
    659 	/* Get a count of the v4 & v6 addresses */
    660 	for (aip = ai_dst; aip != NULL; aip = aip->ai_next) {
    661 		switch (aip->ai_family) {
    662 		case AF_INET:
    663 			num_v4++;
    664 			break;
    665 		case AF_INET6:
    666 			num_v6++;
    667 			break;
    668 		}
    669 	}
    670 
    671 	if (*family == AF_UNSPEC && !probe_all) {
    672 		*family = ai_dst->ai_family;
    673 	}
    674 
    675 	/* resolve gateways */
    676 	if (gw_count > 0) {
    677 		get_gwaddrs(gwlist, *family, gwIPlist, gwIP6list,
    678 		    &num_resolved_gw, &num_resolved_gw6);
    679 
    680 		/* we couldn't resolve a gateway as an IPv6 host */
    681 		if (num_resolved_gw6 != gw_count && num_v6 != 0) {
    682 			if (*family == AF_INET6 || *family == AF_UNSPEC)
    683 				print_unknown_host_msg(" IPv6",
    684 				    gwlist[num_resolved_gw6]);
    685 			num_v6 = 0;
    686 		}
    687 
    688 		/* we couldn't resolve a gateway as an IPv4 host */
    689 		if (num_resolved_gw != gw_count && num_v4 != 0) {
    690 			if (*family == AF_INET || *family == AF_UNSPEC)
    691 				print_unknown_host_msg(" IPv4",
    692 				    gwlist[num_resolved_gw]);
    693 			num_v4 = 0;
    694 		}
    695 	}
    696 
    697 	*ai_dstp = (num_v4 + num_v6 > 0) ? ai_dst : NULL;
    698 }
    699 
    700 /*
    701  * Given IP address or hostname, return v4 and v6 hostinfo lists.
    702  * Assumes that hostinfo ** ptrs are non-null.
    703  */
    704 static void
    705 get_hostinfo(char *host, int family, struct addrinfo **aipp)
    706 {
    707 	struct addrinfo hints, *ai;
    708 	struct in6_addr addr6;
    709 	struct in_addr addr;
    710 	char abuf[INET6_ADDRSTRLEN];	/* use for inet_ntop() */
    711 	int rc;
    712 
    713 	/*
    714 	 * Take care of v4-mapped addresses. It should run same as v4, after
    715 	 * chopping off the prefix, leaving the IPv4 address
    716 	 */
    717 	if ((inet_pton(AF_INET6, host, &addr6) > 0) &&
    718 	    IN6_IS_ADDR_V4MAPPED(&addr6)) {
    719 		/* peel off the "mapping" stuff, leaving 32 bit IPv4 address */
    720 		IN6_V4MAPPED_TO_INADDR(&addr6, &addr);
    721 
    722 		/* convert it back to a string */
    723 		(void) inet_ntop(AF_INET, &addr, abuf, sizeof (abuf));
    724 
    725 		/* now the host is an IPv4 address */
    726 		(void) strcpy(host, abuf);
    727 
    728 		/*
    729 		 * If it's a mapped address, we convert it into IPv4
    730 		 * address because traceroute will send and receive IPv4
    731 		 * packets for that address. Therefore, it's a failure case to
    732 		 * ask get_hostinfo() to treat a mapped address as an IPv6
    733 		 * address.
    734 		 */
    735 		if (family == AF_INET6) {
    736 			return;
    737 		}
    738 	}
    739 
    740 	(void) memset(&hints, 0, sizeof (hints));
    741 	hints.ai_family = family;
    742 	hints.ai_flags = AI_ADDRCONFIG | AI_CANONNAME;
    743 	rc = getaddrinfo(host, NULL, &hints, &ai);
    744 	if (rc != 0) {
    745 		if (rc != EAI_NONAME)
    746 			Fprintf(stderr, "%s: getaddrinfo: %s\n", prog,
    747 			    gai_strerror(rc));
    748 		*aipp = NULL;
    749 		return;
    750 	}
    751 	*aipp = ai;
    752 }
    753 
    754 /*
    755  * Calculate the packet length to be used, and check against the valid range.
    756  * Returns -1 if range check fails.
    757  */
    758 static uint_t
    759 calc_packetlen(int plen_input, struct pr_set *pr)
    760 {
    761 	int minpacket;			/* min ip packet size */
    762 	int optlen;			/* length of ip options */
    763 	int plen;
    764 
    765 	/*
    766 	 * LBNL bug fixed: miscalculation of optlen
    767 	 */
    768 	if (gw_count > 0) {
    769 		/*
    770 		 * IPv4:
    771 		 * ----
    772 		 * 5 (NO OPs) + 3 (code, len, ptr) + gateways
    773 		 * IP options field can hold up to 9 gateways. But the API
    774 		 * allows you to specify only 8, because the last one is the
    775 		 * destination host. When this packet is sent, on the wire
    776 		 * you see one gateway replaced by 4 NO OPs. The other 1 NO
    777 		 * OP is for alignment
    778 		 *
    779 		 * IPv6:
    780 		 * ----
    781 		 * Well, formula is different, but the result is same.
    782 		 * 8 byte fixed part for Type 0 Routing header, followed by
    783 		 * gateway addresses
    784 		 */
    785 		optlen = 8 + gw_count * pr->addr_len;
    786 	} else {
    787 		optlen = 0;
    788 	}
    789 
    790 	/* take care of the packet length calculations and checks */
    791 	minpacket = pr->ip_hdr_len + sizeof (struct outdata) + optlen;
    792 	if (useicmp)
    793 		minpacket += pr->icmp_minlen;	/* minimum ICMP header size */
    794 	else
    795 		minpacket += sizeof (struct udphdr);
    796 	plen = plen_input;
    797 	if (plen == 0) {
    798 		plen = minpacket;		/* minimum sized packet */
    799 	} else if (minpacket > plen || plen > IP_MAXPACKET) {
    800 		Fprintf(stderr, "%s: %s packet size must be >= %d and <= %d\n",
    801 		    prog, pr->name, minpacket, IP_MAXPACKET);
    802 		return (0);
    803 	}
    804 
    805 	return (plen);
    806 }
    807 
    808 /*
    809  * Sets the source address by resolving -i and -s arguments, or if -i and -s
    810  * don't dictate any, it sets the pick_src to make sure traceroute uses the
    811  * kernel's pick of the source address.
    812  * Returns number of interfaces configured on the source host, 0 on error or
    813  * there's no interface which is up amd not a loopback.
    814  */
    815 static int
    816 set_src_addr(struct pr_set *pr, struct ifaddrlist **alp)
    817 {
    818 	union any_in_addr *ap;
    819 	struct ifaddrlist *al = NULL;
    820 	struct ifaddrlist *tmp1_al = NULL;
    821 	struct ifaddrlist *tmp2_al = NULL;
    822 	/* LINTED E_BAD_PTR_CAST_ALIGN */
    823 	struct sockaddr_in *sin_from = (struct sockaddr_in *)pr->from;
    824 	/* LINTED E_BAD_PTR_CAST_ALIGN */
    825 	struct sockaddr_in6 *sin6_from = (struct sockaddr_in6 *)pr->from;
    826 	struct addrinfo *aip;
    827 	char errbuf[ERRBUFSIZE];
    828 	char abuf[INET6_ADDRSTRLEN];		/* use for inet_ntop() */
    829 	int num_ifs;				/* all the interfaces  */
    830 	int num_src_ifs;			/* exclude loopback and down */
    831 	int i;
    832 	uint_t ifaddrflags = 0;
    833 
    834 	source = source_input;
    835 
    836 	if (device != NULL)
    837 		ifaddrflags |= LIFC_UNDER_IPMP;
    838 
    839 	/* get the interface address list */
    840 	num_ifs = ifaddrlist(&al, pr->family, ifaddrflags, errbuf);
    841 	if (num_ifs < 0) {
    842 		Fprintf(stderr, "%s: ifaddrlist: %s\n", prog, errbuf);
    843 		exit(EXIT_FAILURE);
    844 	}
    845 
    846 	num_src_ifs = 0;
    847 	for (i = 0; i < num_ifs; i++) {
    848 		if (!(al[i].flags & IFF_LOOPBACK) && (al[i].flags & IFF_UP))
    849 			num_src_ifs++;
    850 	}
    851 
    852 	if (num_src_ifs == 0) {
    853 		Fprintf(stderr, "%s: can't find any %s network interfaces\n",
    854 		    prog, pr->name);
    855 		return (0);
    856 	}
    857 
    858 	/* verify the device */
    859 	if (device != NULL) {
    860 		tmp1_al = find_device(al, num_ifs, device);
    861 
    862 		if (tmp1_al == NULL) {
    863 			Fprintf(stderr, "%s: %s (index %d) is an invalid %s"
    864 			    " interface\n", prog, device, if_index, pr->name);
    865 			free(al);
    866 			return (0);
    867 		}
    868 	}
    869 
    870 	/* verify the source address */
    871 	if (source != NULL) {
    872 		get_hostinfo(source, pr->family, &aip);
    873 		if (aip == NULL) {
    874 			Fprintf(stderr,
    875 			    "%s: %s is an invalid %s source address\n",
    876 			    prog, source, pr->name);
    877 
    878 			free(al);
    879 			return (0);
    880 		}
    881 
    882 		source = aip->ai_canonname;
    883 
    884 		if (pr->family == AF_INET)
    885 			ap = (union any_in_addr *)
    886 			    /* LINTED E_BAD_PTR_CAST_ALIGN */
    887 			    &((struct sockaddr_in *)aip->ai_addr)->sin_addr;
    888 		else
    889 			ap = (union any_in_addr *)
    890 			    /* LINTED E_BAD_PTR_CAST_ALIGN */
    891 			    &((struct sockaddr_in6 *)aip->ai_addr)->sin6_addr;
    892 
    893 		/*
    894 		 * LBNL bug fixed: used to accept any src address
    895 		 */
    896 		tmp2_al = find_ifaddr(al, num_ifs, ap, pr->family);
    897 		if (tmp2_al == NULL) {
    898 			(void) inet_ntop(pr->family, ap, abuf, sizeof (abuf));
    899 			Fprintf(stderr, "%s: %s is not a local %s address\n",
    900 			    prog, abuf, pr->name);
    901 			free(al);
    902 			freeaddrinfo(aip);
    903 			return (0);
    904 		}
    905 	}
    906 
    907 	pick_src = _B_FALSE;
    908 
    909 	if (source == NULL) {			/* no -s used */
    910 		if (device == NULL) {		/* no -i used, no -s used */
    911 			pick_src = _B_TRUE;
    912 		} else {			/* -i used, no -s used */
    913 			/*
    914 			 * -i used, but not -s, and it's IPv4: set the source
    915 			 * address to whatever the interface has configured on
    916 			 * it.
    917 			 */
    918 			if (pr->family == AF_INET)
    919 				set_sin(pr->from, &(tmp1_al->addr), pr->family);
    920 			else
    921 				pick_src = _B_TRUE;
    922 		}
    923 	} else {				/* -s used */
    924 		if (device == NULL) {		/* no -i used, -s used */
    925 			set_sin(pr->from, ap, pr->family);
    926 
    927 			if (aip->ai_next != NULL) {
    928 				(void) inet_ntop(pr->family, pr->from_sin_addr,
    929 				    abuf, sizeof (abuf));
    930 				Fprintf(stderr, "%s: Warning: %s has multiple "
    931 				    "addresses; using %s\n", prog, source,
    932 				    abuf);
    933 			}
    934 		} else {			/* -i and -s used */
    935 			/*
    936 			 * Make sure the source specified matches the
    937 			 * interface address. You only care about this for IPv4
    938 			 * IPv6 can handle IF not matching src address
    939 			 */
    940 			if (pr->family == AF_INET) {
    941 				if (!has_addr(aip, &tmp1_al->addr)) {
    942 					Fprintf(stderr,
    943 					    "%s: %s is not on interface %s\n",
    944 					    prog, source, device);
    945 					exit(EXIT_FAILURE);
    946 				}
    947 				/*
    948 				 * make sure we use the one matching the
    949 				 * interface's address
    950 				 */
    951 				*ap = tmp1_al->addr;
    952 			}
    953 
    954 			set_sin(pr->from, ap, pr->family);
    955 		}
    956 	}
    957 
    958 	/*
    959 	 * Binding at this point will set the source address to be used
    960 	 * for both IPv4 (when raw IP datagrams are not required) and
    961 	 * IPv6.  If the address being bound to is zero, then the kernel
    962 	 * will end up choosing the source address when the datagram is
    963 	 * sent.
    964 	 *
    965 	 * For raw IPv4 datagrams, the source address is initialized
    966 	 * within traceroute() along with the outbound destination
    967 	 * address.
    968 	 */
    969 	if (pr->family == AF_INET && !raw_req) {
    970 		sin_from->sin_family = AF_INET;
    971 		sin_from->sin_port = htons(ident);
    972 		if (bind(sndsock4, (struct sockaddr *)pr->from,
    973 			sizeof (struct sockaddr_in)) < 0) {
    974 			Fprintf(stderr, "%s: bind: %s\n", prog,
    975 			    strerror(errno));
    976 			exit(EXIT_FAILURE);
    977 		}
    978 	} else if (pr->family == AF_INET6) {
    979 		sin6_from->sin6_family = AF_INET6;
    980 		sin6_from->sin6_port = htons(ident);
    981 		if (bind(sndsock6, (struct sockaddr *)pr->from,
    982 			sizeof (struct sockaddr_in6)) < 0) {
    983 			Fprintf(stderr, "%s: bind: %s\n", prog,
    984 			    strerror(errno));
    985 			exit(EXIT_FAILURE);
    986 		}
    987 
    988 		whereto6.sin6_flowinfo = htonl((class << 20) | flow);
    989 	}
    990 	*alp = al;
    991 	return (num_ifs);
    992 }
    993 
    994 /*
    995  * Returns the complete ifaddrlist structure matching the desired interface
    996  * address. Ignores interfaces which are either down or loopback.
    997  */
    998 static struct ifaddrlist *
    999 find_ifaddr(struct ifaddrlist *al, int len, union any_in_addr *addr,
   1000     int family)
   1001 {
   1002 	struct ifaddrlist *tmp_al = al;
   1003 	int i;
   1004 	size_t addr_len = (family == AF_INET) ? sizeof (struct in_addr) :
   1005 	    sizeof (struct in6_addr);
   1006 
   1007 	for (i = 0; i < len; i++, tmp_al++) {
   1008 		if ((!(tmp_al->flags & IFF_LOOPBACK) &&
   1009 		    (tmp_al->flags & IFF_UP)) &&
   1010 		    (memcmp(&tmp_al->addr, addr, addr_len) == 0))
   1011 			break;
   1012 	}
   1013 
   1014 	if (i < len) {
   1015 		return (tmp_al);
   1016 	} else {
   1017 		return (NULL);
   1018 	}
   1019 }
   1020 
   1021 /*
   1022  * Returns the complete ifaddrlist structure matching the desired interface name
   1023  * Ignores interfaces which are either down or loopback.
   1024  */
   1025 static struct ifaddrlist *
   1026 find_device(struct ifaddrlist *al, int len, char *device)
   1027 {
   1028 	struct ifaddrlist *tmp_al = al;
   1029 	int i;
   1030 
   1031 	for (i = 0; i < len; i++, tmp_al++) {
   1032 		if ((!(tmp_al->flags & IFF_LOOPBACK) &&
   1033 		    (tmp_al->flags & IFF_UP)) &&
   1034 		    (strcmp(tmp_al->device, device) == 0))
   1035 			break;
   1036 	}
   1037 
   1038 	if (i < len) {
   1039 		return (tmp_al);
   1040 	} else {
   1041 		return (NULL);
   1042 	}
   1043 }
   1044 
   1045 /*
   1046  * returns _B_TRUE if given hostinfo contains the given address
   1047  */
   1048 static boolean_t
   1049 has_addr(struct addrinfo *ai, union any_in_addr *addr)
   1050 {
   1051 	struct addrinfo *ai_tmp = NULL;
   1052 	union any_in_addr *ap;
   1053 
   1054 	for (ai_tmp = ai; ai_tmp != NULL; ai_tmp = ai_tmp->ai_next) {
   1055 		if (ai_tmp->ai_family == AF_INET6)
   1056 			continue;
   1057 		ap = (union any_in_addr *)
   1058 		    /* LINTED E_BAD_PTR_CAST_ALIGN */
   1059 		    &((struct sockaddr_in *)ai_tmp->ai_addr)->sin_addr;
   1060 		if (memcmp(ap, addr, sizeof (struct in_addr)) == 0)
   1061 			break;
   1062 	}
   1063 
   1064 	if (ai_tmp != NULL) {
   1065 		return (_B_TRUE);
   1066 	} else {
   1067 		return (_B_FALSE);
   1068 	}
   1069 }
   1070 
   1071 /*
   1072  * Resolve the gateway names, splitting results into v4 and v6 lists.
   1073  * Gateway addresses are added to the appropriate passed-in array; the
   1074  * number of resolved gateways for each af is returned in resolved[6].
   1075  * Assumes that passed-in arrays are large enough for MAX_GWS[6] addrs
   1076  * and resolved[6] ptrs are non-null; ignores array and counter if the
   1077  * address family param makes them irrelevant.
   1078  */
   1079 static void
   1080 get_gwaddrs(char **gwlist, int family, union any_in_addr *gwIPlist,
   1081     union any_in_addr *gwIPlist6, int *resolved, int *resolved6)
   1082 {
   1083 	int i;
   1084 	boolean_t check_v4 = _B_TRUE, check_v6 = _B_TRUE;
   1085 	struct addrinfo *ai = NULL;
   1086 	struct addrinfo *aip = NULL;
   1087 
   1088 	*resolved = *resolved6 = 0;
   1089 	switch (family) {
   1090 	case AF_UNSPEC:
   1091 		break;
   1092 	case AF_INET:
   1093 		check_v6 = _B_FALSE;
   1094 		break;
   1095 	case AF_INET6:
   1096 		check_v4 = _B_FALSE;
   1097 		break;
   1098 	default:
   1099 		return;
   1100 	}
   1101 
   1102 	if (check_v4 && gw_count >= MAX_GWS) {
   1103 		check_v4 = _B_FALSE;
   1104 		Fprintf(stderr, "%s: too many IPv4 gateways\n", prog);
   1105 		num_v4 = 0;
   1106 	}
   1107 	if (check_v6 && gw_count >= MAX_GWS6) {
   1108 		check_v6 = _B_FALSE;
   1109 		Fprintf(stderr, "%s: too many IPv6 gateways\n", prog);
   1110 		num_v6 = 0;
   1111 	}
   1112 
   1113 	for (i = 0; i < gw_count; i++) {
   1114 		if (!check_v4 && !check_v6)
   1115 			return;
   1116 		get_hostinfo(gwlist[i], family, &ai);
   1117 		if (ai == NULL)
   1118 			return;
   1119 		if (check_v4 && num_v4 != 0) {
   1120 			check_v4 = _B_FALSE;
   1121 			for (aip = ai; aip != NULL; aip = aip->ai_next) {
   1122 				if (aip->ai_family == AF_INET) {
   1123 					/* LINTED E_BAD_PTR_CAST_ALIGN */
   1124 					bcopy(&((struct sockaddr_in *)
   1125 					    aip->ai_addr)->sin_addr,
   1126 					    &gwIPlist[i].addr,
   1127 					    aip->ai_addrlen);
   1128 					(*resolved)++;
   1129 					check_v4 = _B_TRUE;
   1130 					break;
   1131 				}
   1132 			}
   1133 		} else if (check_v4) {
   1134 			check_v4 = _B_FALSE;
   1135 		}
   1136 		if (check_v6 && num_v6 != 0) {
   1137 			check_v6 = _B_FALSE;
   1138 			for (aip = ai; aip != NULL; aip = aip->ai_next) {
   1139 				if (aip->ai_family == AF_INET6) {
   1140 					/* LINTED E_BAD_PTR_CAST_ALIGN */
   1141 					bcopy(&((struct sockaddr_in6 *)
   1142 					    aip->ai_addr)->sin6_addr,
   1143 					    &gwIPlist6[i].addr6,
   1144 					    aip->ai_addrlen);
   1145 					(*resolved6)++;
   1146 					check_v6 = _B_TRUE;
   1147 					break;
   1148 				}
   1149 			}
   1150 		} else if (check_v6) {
   1151 			check_v6 = _B_FALSE;
   1152 		}
   1153 	}
   1154 	freeaddrinfo(ai);
   1155 }
   1156 
   1157 /*
   1158  * set protocol specific values here
   1159  */
   1160 static void
   1161 setup_protocol(struct pr_set *pr, int family)
   1162 {
   1163 	/*
   1164 	 * Set the global variables for each AF. This is going to save us lots
   1165 	 * of "if (family == AF_INET)... else .."
   1166 	 */
   1167 	pr->family = family;
   1168 
   1169 	if (family == AF_INET) {
   1170 		if (!docksum) {
   1171 			Fprintf(stderr,
   1172 			    "%s: Warning: checksums disabled\n", prog);
   1173 		}
   1174 		(void) strcpy(pr->name, "IPv4");
   1175 		(void) strcpy(pr->icmp, "icmp");
   1176 		pr->icmp_minlen = ICMP_MINLEN;
   1177 		pr->addr_len = sizeof (struct in_addr);
   1178 		pr->ip_hdr_len = sizeof (struct ip);
   1179 		pr->sock_size = sizeof (struct sockaddr_in);
   1180 		pr->to = (struct sockaddr *)&whereto;
   1181 		pr->from = (struct sockaddr *)&wherefrom;
   1182 		pr->from_sin_addr = (void *)&wherefrom.sin_addr;
   1183 		pr->gwIPlist = gwIPlist;
   1184 		pr->set_buffers_fn = set_buffers;
   1185 		pr->check_reply_fn = check_reply;
   1186 		pr->print_icmp_other_fn = print_icmp_other;
   1187 		pr->print_addr_fn = print_addr;
   1188 		pr->packlen = calc_packetlen(packlen_input, pr);
   1189 	} else {
   1190 		(void) strcpy(pr->name, "IPv6");
   1191 		(void) strcpy(pr->icmp, "ipv6-icmp");
   1192 		pr->icmp_minlen = ICMP6_MINLEN;
   1193 		pr->addr_len = sizeof (struct in6_addr);
   1194 		pr->ip_hdr_len = sizeof (struct ip6_hdr);
   1195 		pr->sock_size = sizeof (struct sockaddr_in6);
   1196 		pr->to = (struct sockaddr *)&whereto6;
   1197 		pr->from = (struct sockaddr *)&wherefrom6;
   1198 		pr->from_sin_addr = (void *)&wherefrom6.sin6_addr;
   1199 		pr->gwIPlist = gwIP6list;
   1200 		pr->set_buffers_fn = set_buffers6;
   1201 		pr->check_reply_fn = check_reply6;
   1202 		pr->print_icmp_other_fn = print_icmp_other6;
   1203 		pr->print_addr_fn = print_addr6;
   1204 		pr->packlen = calc_packetlen(packlen_input, pr);
   1205 	}
   1206 	if (pr->packlen == 0)
   1207 		exit(EXIT_FAILURE);
   1208 }
   1209 
   1210 /*
   1211  * setup the sockets for the given protocol's address family
   1212  */
   1213 static void
   1214 setup_socket(struct pr_set *pr, int packet_len)
   1215 {
   1216 	int on = 1;
   1217 	struct protoent *pe;
   1218 	int type;
   1219 	int proto;
   1220 	int int_op;
   1221 	int rsock;
   1222 	int ssock;
   1223 
   1224 	if ((pe = getprotobyname(pr->icmp)) == NULL) {
   1225 		Fprintf(stderr, "%s: unknown protocol %s\n", prog, pr->icmp);
   1226 		exit(EXIT_FAILURE);
   1227 	}
   1228 
   1229 	/* privilege bracketing */
   1230 	(void) __priv_bracket(PRIV_ON);
   1231 
   1232 	if ((rsock = socket(pr->family, SOCK_RAW, pe->p_proto)) < 0) {
   1233 		Fprintf(stderr, "%s: icmp socket: %s\n", prog, strerror(errno));
   1234 		exit(EXIT_FAILURE);
   1235 	}
   1236 
   1237 	if (options & SO_DEBUG) {
   1238 		if (setsockopt(rsock, SOL_SOCKET, SO_DEBUG, (char *)&on,
   1239 		    sizeof (on)) < 0) {
   1240 			Fprintf(stderr, "%s: SO_DEBUG: %s\n", prog,
   1241 			    strerror(errno));
   1242 			exit(EXIT_FAILURE);
   1243 		}
   1244 	}
   1245 	if (options & SO_DONTROUTE) {
   1246 		if (setsockopt(rsock, SOL_SOCKET, SO_DONTROUTE, (char *)&on,
   1247 		    sizeof (on)) < 0) {
   1248 			Fprintf(stderr, "%s: SO_DONTROUTE: %s\n", prog,
   1249 			    strerror(errno));
   1250 			exit(EXIT_FAILURE);
   1251 		}
   1252 	}
   1253 
   1254 	if (pr->family == AF_INET6) {
   1255 		/* Enable receipt of destination address info */
   1256 		if (setsockopt(rsock, IPPROTO_IPV6, IPV6_RECVPKTINFO,
   1257 		    (char *)&on, sizeof (on)) < 0) {
   1258 			Fprintf(stderr, "%s: IPV6_RECVPKTINFO: %s\n", prog,
   1259 			    strerror(errno));
   1260 			exit(EXIT_FAILURE);
   1261 		}
   1262 		/* Enable receipt of hoplimit info */
   1263 		if (setsockopt(rsock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT,
   1264 		    (char *)&on, sizeof (on)) < 0) {
   1265 			Fprintf(stderr, "%s: IPV6_RECVHOPLIMIT: %s\n", prog,
   1266 			    strerror(errno));
   1267 			exit(EXIT_FAILURE);
   1268 		}
   1269 
   1270 	}
   1271 
   1272 	/*
   1273 	 * Initialize the socket type and protocol based on the address
   1274 	 * family, whether or not a raw IP socket is required (for IPv4)
   1275 	 * or whether ICMP will be used instead of UDP.
   1276 	 *
   1277 	 * For historical reasons, the datagrams sent out by
   1278 	 * traceroute(1M) do not have the "don't fragment" flag set.  For
   1279 	 * this reason as well as the ability to set the Loose Source and
   1280 	 * Record Route (LSRR) option, a raw IP socket will be used for
   1281 	 * IPv4 when run in the global zone.  Otherwise, the actual
   1282 	 * datagram that will be sent will be a regular UDP or ICMP echo
   1283 	 * request packet.  However for convenience and for future options
   1284 	 * when other IP header information may be specified using
   1285 	 * traceroute, the buffer including the raw IP and UDP or ICMP
   1286 	 * header is always filled in.  When the probe is actually sent,
   1287 	 * the size of the request and the start of the packet is set
   1288 	 * according to the type of datagram to send.
   1289 	 */
   1290 	if (pr->family == AF_INET && raw_req) {
   1291 		type = SOCK_RAW;
   1292 		proto = IPPROTO_RAW;
   1293 	} else if (useicmp) {
   1294 		type = SOCK_RAW;
   1295 		if (pr->family == AF_INET)
   1296 			proto = IPPROTO_ICMP;
   1297 		else
   1298 			proto = IPPROTO_ICMPV6;
   1299 	} else {
   1300 		type = SOCK_DGRAM;
   1301 		proto = IPPROTO_UDP;
   1302 	}
   1303 	ssock = socket(pr->family, type, proto);
   1304 
   1305 	if (ssock < 0) {
   1306 		if (proto == IPPROTO_RAW) {
   1307 			Fprintf(stderr, "%s: raw socket: %s\n", prog,
   1308 			    strerror(errno));
   1309 		} else if (proto == IPPROTO_UDP) {
   1310 			Fprintf(stderr, "%s: udp socket: %s\n", prog,
   1311 			    strerror(errno));
   1312 		} else {
   1313 			Fprintf(stderr, "%s: icmp socket: %s\n", prog,
   1314 			    strerror(errno));
   1315 		}
   1316 		exit(EXIT_FAILURE);
   1317 	}
   1318 
   1319 	if (setsockopt(ssock, SOL_SOCKET, SO_SNDBUF, (char *)&packet_len,
   1320 	    sizeof (packet_len)) < 0) {
   1321 		Fprintf(stderr, "%s: SO_SNDBUF: %s\n", prog, strerror(errno));
   1322 		exit(EXIT_FAILURE);
   1323 	}
   1324 
   1325 	if (pr->family == AF_INET && raw_req) {
   1326 		if (setsockopt(ssock, IPPROTO_IP, IP_HDRINCL, (char *)&on,
   1327 		    sizeof (on)) < 0) {
   1328 			Fprintf(stderr, "%s: IP_HDRINCL: %s\n", prog,
   1329 			    strerror(errno));
   1330 			exit(EXIT_FAILURE);
   1331 		}
   1332 	}
   1333 
   1334 	if (options & SO_DEBUG) {
   1335 		if (setsockopt(ssock, SOL_SOCKET, SO_DEBUG, (char *)&on,
   1336 		    sizeof (on)) < 0) {
   1337 			Fprintf(stderr, "%s: SO_DEBUG: %s\n", prog,
   1338 			    strerror(errno));
   1339 			exit(EXIT_FAILURE);
   1340 		}
   1341 	}
   1342 	if (options & SO_DONTROUTE) {
   1343 		if (setsockopt(ssock, SOL_SOCKET, SO_DONTROUTE,
   1344 		    (char *)&on, sizeof (on)) < 0) {
   1345 			Fprintf(stderr, "%s: SO_DONTROUTE: %s\n", prog,
   1346 			    strerror(errno));
   1347 			exit(EXIT_FAILURE);
   1348 		}
   1349 	}
   1350 
   1351 	/*
   1352 	 * If a raw IPv4 packet is going to be sent, the Type of Service
   1353 	 * field in the packet will be initialized in set_buffers().
   1354 	 * Otherwise, it is initialized here using the IPPROTO_IP level
   1355 	 * socket option.
   1356 	 */
   1357 	if (settos && !raw_req) {
   1358 		int_op = tos;
   1359 		if (setsockopt(ssock, IPPROTO_IP, IP_TOS, (char *)&int_op,
   1360 		    sizeof (int_op)) < 0) {
   1361 			Fprintf(stderr, "%s: IP_TOS: %s\n", prog,
   1362 			    strerror(errno));
   1363 			exit(EXIT_FAILURE);
   1364 		}
   1365 	}
   1366 
   1367 	/* We enable or disable to not depend on the kernel default */
   1368 	if (pr->family == AF_INET) {
   1369 		if (setsockopt(ssock, IPPROTO_IP, IP_DONTFRAG,
   1370 		    (char *)&dontfrag, sizeof (dontfrag)) == -1) {
   1371 			Fprintf(stderr, "%s: IP_DONTFRAG %s\n", prog,
   1372 			    strerror(errno));
   1373 			exit(EXIT_FAILURE);
   1374 		}
   1375 	} else {
   1376 		if (setsockopt(ssock, IPPROTO_IPV6, IPV6_DONTFRAG,
   1377 		    (char *)&dontfrag, sizeof (dontfrag)) == -1) {
   1378 			Fprintf(stderr, "%s: IPV6_DONTFRAG %s\n", prog,
   1379 			    strerror(errno));
   1380 			exit(EXIT_FAILURE);
   1381 		}
   1382 	}
   1383 
   1384 	if (pr->family == AF_INET) {
   1385 		rcvsock4 = rsock;
   1386 		sndsock4 = ssock;
   1387 	} else {
   1388 		rcvsock6 = rsock;
   1389 		sndsock6 = ssock;
   1390 	}
   1391 	/* Revert to non-privileged user after configuring sockets */
   1392 	(void) __priv_bracket(PRIV_OFF);
   1393 }
   1394 
   1395 /*
   1396  * If we are "probing all", this function calls traceroute() for each IP address
   1397  * of the target, otherwise calls only once. Returns _B_FALSE if traceroute()
   1398  * fails.
   1399  */
   1400 static void
   1401 trace_it(struct addrinfo *ai_dst)
   1402 {
   1403 	struct msghdr msg6;
   1404 	int num_dst_IPaddrs;
   1405 	struct addrinfo *aip;
   1406 	int i;
   1407 
   1408 	if (!probe_all)
   1409 		num_dst_IPaddrs = 1;
   1410 	else
   1411 		num_dst_IPaddrs = num_v4 + num_v6;
   1412 
   1413 	/*
   1414 	 * Initialize the msg6 structure using the hoplimit for the first
   1415 	 * probe packet, gateway addresses and the outgoing interface index.
   1416 	 */
   1417 	if (ai_dst->ai_family == AF_INET6 || (probe_all && num_v6)) {
   1418 		msg6.msg_control = NULL;
   1419 		msg6.msg_controllen = 0;
   1420 		set_ancillary_data(&msg6, first_ttl, pr6->gwIPlist, gw_count,
   1421 		    if_index);
   1422 	}
   1423 
   1424 	/* run traceroute for all the IP addresses of the multihomed dest */
   1425 	for (aip = ai_dst, i = 0; i < num_dst_IPaddrs && aip != NULL; i++) {
   1426 		union any_in_addr *addrp;
   1427 		if (aip->ai_family == AF_INET) {
   1428 			addrp = (union any_in_addr *)
   1429 			    /* LINTED E_BAD_PTR_CAST_ALIGN */
   1430 			    &((struct sockaddr_in *)
   1431 			    aip->ai_addr)->sin_addr;
   1432 			set_sin((struct sockaddr *)pr4->to, addrp,
   1433 			    aip->ai_family);
   1434 			traceroute(addrp, &msg6, pr4, num_ifs4, al4);
   1435 		} else {
   1436 			addrp = (union any_in_addr *)
   1437 			    /* LINTED E_BAD_PTR_CAST_ALIGN */
   1438 			    &((struct sockaddr_in6 *)
   1439 			    aip->ai_addr)->sin6_addr;
   1440 			set_sin((struct sockaddr *)pr6->to, addrp,
   1441 			    aip->ai_family);
   1442 			traceroute(addrp, &msg6, pr6, num_ifs6, al6);
   1443 		}
   1444 		aip = aip->ai_next;
   1445 		if (i < (num_dst_IPaddrs - 1))
   1446 			(void) putchar('\n');
   1447 	}
   1448 }
   1449 
   1450 /*
   1451  * set the IP address in a sockaddr struct
   1452  */
   1453 static void
   1454 set_sin(struct sockaddr *sock, union any_in_addr *addr, int family)
   1455 {
   1456 	sock->sa_family = family;
   1457 
   1458 	if (family == AF_INET)
   1459 		/* LINTED E_BAD_PTR_CAST_ALIGN */
   1460 		((struct sockaddr_in *)sock)->sin_addr = addr->addr;
   1461 	else
   1462 		/* LINTED E_BAD_PTR_CAST_ALIGN */
   1463 		((struct sockaddr_in6 *)sock)->sin6_addr = addr->addr6;
   1464 }
   1465 
   1466 /*
   1467  * returns the IF name on which the given IP address is configured
   1468  */
   1469 static char *
   1470 device_name(struct ifaddrlist *al, int len, union any_in_addr *ip_addr,
   1471     struct pr_set *pr)
   1472 {
   1473 	int i;
   1474 	struct ifaddrlist *tmp_al;
   1475 
   1476 	tmp_al = al;
   1477 
   1478 	for (i = 0; i < len; i++, tmp_al++) {
   1479 		if (memcmp(&tmp_al->addr, ip_addr, pr->addr_len) == 0) {
   1480 			return (tmp_al->device);
   1481 		}
   1482 	}
   1483 
   1484 	return (NULL);
   1485 }
   1486 
   1487 /*
   1488  * Trace the route to the host with given IP address.
   1489  */
   1490 static void
   1491 traceroute(union any_in_addr *ip_addr, struct msghdr *msg6, struct pr_set *pr,
   1492     int num_ifs, struct ifaddrlist *al)
   1493 {
   1494 	int ttl;
   1495 	int probe;
   1496 	uchar_t type;				/* icmp type */
   1497 	uchar_t code;				/* icmp code */
   1498 	int reply;
   1499 	int seq = 0;
   1500 	char abuf[INET6_ADDRSTRLEN];		/* use for inet_ntop() */
   1501 	int longjmp_return;			/* return value from longjump */
   1502 	struct ip *ip = (struct ip *)packet;
   1503 	boolean_t got_there = _B_FALSE;		/* we hit the destination */
   1504 	static boolean_t first_pkt = _B_TRUE;
   1505 	int hoplimit;				/* hoplimit for IPv6 packets */
   1506 	struct in6_addr addr6;
   1507 	int num_src_ifs;			/* excludes down and loopback */
   1508 	struct msghdr in_msg;
   1509 	struct iovec iov;
   1510 	int *intp;
   1511 	int sndsock;
   1512 	int rcvsock;
   1513 
   1514 	msg6->msg_name = pr->to;
   1515 	msg6->msg_namelen = sizeof (struct sockaddr_in6);
   1516 	sndsock =  (pr->family == AF_INET) ? sndsock4 : sndsock6;
   1517 	rcvsock =  (pr->family == AF_INET) ? rcvsock4 : rcvsock6;
   1518 
   1519 	/* carry out the source address selection */
   1520 	if (pick_src) {
   1521 		union any_in_addr src_addr;
   1522 		char *dev_name;
   1523 		int i;
   1524 
   1525 		/*
   1526 		 * If there's a gateway, a routing header as a consequence, our
   1527 		 * kernel picks the source address based on the first hop
   1528 		 * address, rather than final destination address.
   1529 		 */
   1530 		if (gw_count > 0) {
   1531 			(void) select_src_addr(pr->gwIPlist, &src_addr,
   1532 			    pr->family);
   1533 		} else {
   1534 			(void) select_src_addr(ip_addr, &src_addr, pr->family);
   1535 		}
   1536 		set_sin(pr->from, &src_addr, pr->family);
   1537 
   1538 		/* filter out down and loopback interfaces */
   1539 		num_src_ifs = 0;
   1540 		for (i = 0; i < num_ifs; i++) {
   1541 			if (!(al[i].flags & IFF_LOOPBACK) &&
   1542 			    (al[i].flags & IFF_UP))
   1543 				num_src_ifs++;
   1544 		}
   1545 
   1546 		if (num_src_ifs > 1) {
   1547 			dev_name = device_name(al, num_ifs, &src_addr, pr);
   1548 			if (dev_name == NULL)
   1549 				dev_name = "?";
   1550 
   1551 			(void) inet_ntop(pr->family, pr->from_sin_addr, abuf,
   1552 			    sizeof (abuf));
   1553 			Fprintf(stderr,
   1554 			    "%s: Warning: Multiple interfaces found;"
   1555 			    " using %s @ %s\n", prog, abuf, dev_name);
   1556 		}
   1557 	}
   1558 
   1559 	if (pr->family == AF_INET) {
   1560 		outip4->ip_src = *(struct in_addr *)pr->from_sin_addr;
   1561 		outip4->ip_dst = ip_addr->addr;
   1562 	}
   1563 
   1564 	/*
   1565 	 * If the hostname is an IPv6 literal address, let's not print it twice.
   1566 	 */
   1567 	if (pr->family == AF_INET6 &&
   1568 	    inet_pton(AF_INET6, hostname, &addr6) > 0) {
   1569 		Fprintf(stderr, "%s to %s", prog, hostname);
   1570 	} else {
   1571 		Fprintf(stderr, "%s to %s (%s)", prog, hostname,
   1572 		    inet_ntop(pr->family, ip_addr, abuf, sizeof (abuf)));
   1573 	}
   1574 
   1575 	if (source)
   1576 		Fprintf(stderr, " from %s", source);
   1577 	Fprintf(stderr, ", %d hops max, %d byte packets\n", max_ttl,
   1578 	    pr->packlen);
   1579 	(void) fflush(stderr);
   1580 
   1581 	/*
   1582 	 * Setup the source routing for IPv4. For IPv6, we did the required
   1583 	 * setup in the caller function, trace_it(), because it's independent
   1584 	 * from the IP address of target.
   1585 	 */
   1586 	if (pr->family == AF_INET && gw_count > 0)
   1587 		set_IPv4opt_sourcerouting(sndsock, ip_addr, pr->gwIPlist);
   1588 
   1589 	if (probe_all) {
   1590 		/* interrupt handler sig_handler() jumps back to here */
   1591 		if ((longjmp_return = setjmp(env)) != 0) {
   1592 			switch (longjmp_return) {
   1593 			case SIGINT:
   1594 				Printf("(skipping)\n");
   1595 				return;
   1596 			case SIGQUIT:
   1597 				Printf("(exiting)\n");
   1598 				exit(EXIT_SUCCESS);
   1599 			default:	/* should never happen */
   1600 				exit(EXIT_FAILURE);
   1601 			}
   1602 		}
   1603 		(void) signal(SIGINT, sig_handler);
   1604 	}
   1605 
   1606 	for (ttl = first_ttl; ttl <= max_ttl; ++ttl) {
   1607 		union any_in_addr lastaddr;
   1608 		int timeouts = 0;
   1609 		double rtt;		/* for statistics */
   1610 		int nreceived = 0;
   1611 		double rttmin, rttmax;
   1612 		double rttsum, rttssq;
   1613 		int unreachable;
   1614 
   1615 		got_there = _B_FALSE;
   1616 		unreachable = 0;
   1617 
   1618 		/*
   1619 		 * The following line clears both IPv4 and IPv6 address stored
   1620 		 * in the union.
   1621 		 */
   1622 		lastaddr.addr6 = in6addr_any;
   1623 
   1624 		if ((ttl == (first_ttl + 1)) && (options & SO_DONTROUTE)) {
   1625 			Fprintf(stderr,
   1626 			    "%s: host %s is not on a directly-attached"
   1627 			    " network\n", prog, hostname);
   1628 			break;
   1629 		}
   1630 
   1631 		Printf("%2d ", ttl);
   1632 		(void) fflush(stdout);
   1633 
   1634 		for (probe = 0; (probe < nprobes) && (timeouts < max_timeout);
   1635 		    ++probe) {
   1636 			int cc;
   1637 			struct timeval t1, t2;
   1638 
   1639 			/*
   1640 			 * Put a delay before sending this probe packet. Don't
   1641 			 * delay it if it's the very first packet.
   1642 			 */
   1643 			if (!first_pkt) {
   1644 				if (delay.tv_sec > 0)
   1645 					(void) sleep((uint_t)delay.tv_sec);
   1646 				if (delay.tv_usec > 0)
   1647 					(void) usleep(delay.tv_usec);
   1648 			} else {
   1649 				first_pkt = _B_FALSE;
   1650 			}
   1651 
   1652 			(void) gettimeofday(&t1, NULL);
   1653 
   1654 			if (pr->family == AF_INET) {
   1655 				send_probe(sndsock, pr->to, outip4, seq, ttl,
   1656 				    &t1, pr->packlen);
   1657 			} else {
   1658 				send_probe6(sndsock, msg6, outip6, seq, ttl,
   1659 				    &t1, pr->packlen);
   1660 			}
   1661 
   1662 			/* prepare msghdr for recvmsg() */
   1663 			in_msg.msg_name = pr->from;
   1664 			in_msg.msg_namelen = pr->sock_size;
   1665 
   1666 			iov.iov_base = (char *)packet;
   1667 			iov.iov_len = sizeof (packet);
   1668 
   1669 			in_msg.msg_iov = &iov;
   1670 			in_msg.msg_iovlen = 1;
   1671 
   1672 			in_msg.msg_control = ancillary_data;
   1673 			in_msg.msg_controllen = sizeof (ancillary_data);
   1674 
   1675 			while ((cc = wait_for_reply(rcvsock, &in_msg,
   1676 			    &t1)) != 0) {
   1677 				(void) gettimeofday(&t2, NULL);
   1678 
   1679 				reply = (*pr->check_reply_fn) (&in_msg, cc, seq,
   1680 				    &type, &code);
   1681 
   1682 				in_msg.msg_controllen =
   1683 				    sizeof (ancillary_data);
   1684 				/* Skip short packet */
   1685 				if (reply == REPLY_SHORT_PKT) {
   1686 					continue;
   1687 				}
   1688 
   1689 				timeouts = 0;
   1690 
   1691 				/*
   1692 				 * if reply comes from a different host, print
   1693 				 * the hostname
   1694 				 */
   1695 				if (memcmp(pr->from_sin_addr, &lastaddr,
   1696 				    pr->addr_len) != 0) {
   1697 					(*pr->print_addr_fn) ((uchar_t *)packet,
   1698 					    cc, pr->from);
   1699 					/* store the address response */
   1700 					(void) memcpy(&lastaddr,
   1701 					    pr->from_sin_addr, pr->addr_len);
   1702 				}
   1703 
   1704 				rtt = deltaT(&t1, &t2);
   1705 				if (collect_stat) {
   1706 					record_stats(rtt, &nreceived, &rttmin,
   1707 					    &rttmax, &rttsum, &rttssq);
   1708 				} else {
   1709 					Printf("  %.3f ms", rtt);
   1710 				}
   1711 
   1712 				if (pr->family == AF_INET6) {
   1713 					intp = find_ancillary_data(&in_msg,
   1714 					    IPPROTO_IPV6, IPV6_HOPLIMIT);
   1715 					if (intp == NULL) {
   1716 						Fprintf(stderr,
   1717 						    "%s: can't find "
   1718 						    "IPV6_HOPLIMIT ancillary "
   1719 						    "data\n", prog);
   1720 						exit(EXIT_FAILURE);
   1721 					}
   1722 					hoplimit = *intp;
   1723 				}
   1724 
   1725 				if (reply == REPLY_GOT_TARGET) {
   1726 					got_there = _B_TRUE;
   1727 
   1728 					if (((pr->family == AF_INET) &&
   1729 					    (ip->ip_ttl <= 1)) ||
   1730 					    ((pr->family == AF_INET6) &&
   1731 					    (hoplimit <= 1)))
   1732 						Printf(" !");
   1733 				}
   1734 
   1735 				if (!collect_stat && showttl) {
   1736 					if (pr->family == AF_INET) {
   1737 						Printf(" (ttl=%d)",
   1738 						    (int)ip->ip_ttl);
   1739 					} else if (hoplimit != -1) {
   1740 						Printf(" (hop limit=%d)",
   1741 						    hoplimit);
   1742 					}
   1743 				}
   1744 
   1745 				if (reply == REPLY_GOT_OTHER) {
   1746 					if ((*pr->print_icmp_other_fn)
   1747 					    (type, code)) {
   1748 						unreachable++;
   1749 					}
   1750 				}
   1751 
   1752 				/* special case */
   1753 				if (pr->family == AF_INET &&
   1754 				    type == ICMP_UNREACH &&
   1755 				    code == ICMP_UNREACH_PROTOCOL)
   1756 					got_there = _B_TRUE;
   1757 
   1758 				break;
   1759 			}
   1760 
   1761 			seq = (seq + 1) % (MAX_SEQ + 1);
   1762 
   1763 			if (cc == 0) {
   1764 				Printf(" *");
   1765 				timeouts++;
   1766 			}
   1767 
   1768 			(void) fflush(stdout);
   1769 		}
   1770 
   1771 		if (collect_stat) {
   1772 			print_stats(probe, nreceived, rttmin, rttmax, rttsum,
   1773 			    rttssq);
   1774 		}
   1775 
   1776 		(void) putchar('\n');
   1777 
   1778 		/* either we hit the target or received too many unreachables */
   1779 		if (got_there ||
   1780 		    (unreachable > 0 && unreachable >= nprobes - 1))
   1781 			break;
   1782 	}
   1783 
   1784 	/* Ignore the SIGINT between traceroute() runs */
   1785 	if (probe_all)
   1786 		(void) signal(SIGINT, SIG_IGN);
   1787 }
   1788 
   1789 /*
   1790  * for a given destination address and address family, it finds out what
   1791  * source address kernel is going to pick
   1792  */
   1793 static void
   1794 select_src_addr(union any_in_addr *dst_addr, union any_in_addr *src_addr,
   1795     int family)
   1796 {
   1797 	int tmp_fd;
   1798 	struct sockaddr *sock;
   1799 	struct sockaddr_in *sin;
   1800 	struct sockaddr_in6 *sin6;
   1801 	size_t sock_len;
   1802 
   1803 	sock = (struct sockaddr *)malloc(sizeof (struct sockaddr_in6));
   1804 	if (sock == NULL) {
   1805 		Fprintf(stderr, "%s: malloc %s\n", prog, strerror(errno));
   1806 		exit(EXIT_FAILURE);
   1807 	}
   1808 	(void) bzero(sock, sizeof (struct sockaddr_in6));
   1809 
   1810 	if (family == AF_INET) {
   1811 		/* LINTED E_BAD_PTR_CAST_ALIGN */
   1812 		sin = (struct sockaddr_in *)sock;
   1813 		sin->sin_family = AF_INET;
   1814 		sin->sin_addr = dst_addr->addr;
   1815 		sin->sin_port = IPPORT_ECHO;	/* port shouldn't be 0 */
   1816 		sock_len = sizeof (struct sockaddr_in);
   1817 	} else {
   1818 		/* LINTED E_BAD_PTR_CAST_ALIGN */
   1819 		sin6 = (struct sockaddr_in6 *)sock;
   1820 		sin6->sin6_family = AF_INET6;
   1821 		sin6->sin6_addr = dst_addr->addr6;
   1822 		sin6->sin6_port = IPPORT_ECHO;	/* port shouldn't be 0 */
   1823 		sock_len = sizeof (struct sockaddr_in6);
   1824 	}
   1825 
   1826 	/* open a UDP socket */
   1827 	if ((tmp_fd = socket(family, SOCK_DGRAM, 0)) < 0) {
   1828 		Fprintf(stderr, "%s: udp socket: %s\n", prog,
   1829 		    strerror(errno));
   1830 		exit(EXIT_FAILURE);
   1831 	}
   1832 
   1833 	/* connect it */
   1834 	if (connect(tmp_fd, sock, sock_len) < 0) {
   1835 		/*
   1836 		 * If there's no route to the destination, this connect() call
   1837 		 * fails. We just return all-zero (wildcard) as the source
   1838 		 * address, so that user can get to see "no route to dest"
   1839 		 * message, as it'll try to send the probe packet out and will
   1840 		 * receive ICMP unreachable.
   1841 		 */
   1842 		if (family == AF_INET)
   1843 			src_addr->addr.s_addr = INADDR_ANY;
   1844 		else
   1845 			src_addr->addr6 = in6addr_any;
   1846 		free(sock);
   1847 		return;
   1848 	}
   1849 
   1850 	/* get the local sock info */
   1851 	if (getsockname(tmp_fd, sock, &sock_len) < 0) {
   1852 		Fprintf(stderr, "%s: getsockname: %s\n", prog,
   1853 		    strerror(errno));
   1854 		exit(EXIT_FAILURE);
   1855 	}
   1856 
   1857 	if (family == AF_INET) {
   1858 		/* LINTED E_BAD_PTR_CAST_ALIGN */
   1859 		sin = (struct sockaddr_in *)sock;
   1860 		src_addr->addr = sin->sin_addr;
   1861 	} else {
   1862 		/* LINTED E_BAD_PTR_CAST_ALIGN */
   1863 		sin6 = (struct sockaddr_in6 *)sock;
   1864 		src_addr->addr6 = sin6->sin6_addr;
   1865 	}
   1866 
   1867 	free(sock);
   1868 	(void) close(tmp_fd);
   1869 }
   1870 
   1871 /*
   1872  * Checksum routine for Internet Protocol family headers (C Version)
   1873  */
   1874 ushort_t
   1875 in_cksum(ushort_t *addr, int len)
   1876 {
   1877 	int nleft = len;
   1878 	ushort_t *w = addr;
   1879 	ushort_t answer;
   1880 	int sum = 0;
   1881 
   1882 	/*
   1883 	 *  Our algorithm is simple, using a 32 bit accumulator (sum),
   1884 	 *  we add sequential 16 bit words to it, and at the end, fold
   1885 	 *  back all the carry bits from the top 16 bits into the lower
   1886 	 *  16 bits.
   1887 	 */
   1888 	while (nleft > 1)  {
   1889 		sum += *w++;
   1890 		nleft -= 2;
   1891 	}
   1892 
   1893 	/* mop up an odd byte, if necessary */
   1894 	if (nleft == 1)
   1895 		sum += *(uchar_t *)w;
   1896 
   1897 	/* add back carry outs from top 16 bits to low 16 bits */
   1898 	sum = (sum >> 16) + (sum & 0xffff);	/* add hi 16 to low 16 */
   1899 	sum += (sum >> 16);			/* add carry */
   1900 	answer = ~sum;				/* truncate to 16 bits */
   1901 	return (answer);
   1902 }
   1903 
   1904 /*
   1905  * Wait until a reply arrives or timeout occurs. If packet arrived, read it
   1906  * return the size of the packet read.
   1907  */
   1908 static int
   1909 wait_for_reply(int sock, struct msghdr *msg, struct timeval *tp)
   1910 {
   1911 	fd_set fds;
   1912 	struct timeval now, wait;
   1913 	int cc = 0;
   1914 	int result;
   1915 
   1916 	(void) FD_ZERO(&fds);
   1917 	FD_SET(sock, &fds);
   1918 
   1919 	wait.tv_sec = tp->tv_sec + waittime;
   1920 	wait.tv_usec = tp->tv_usec;
   1921 	(void) gettimeofday(&now, NULL);
   1922 	tv_sub(&wait, &now);
   1923 
   1924 	if (wait.tv_sec < 0 || wait.tv_usec < 0)
   1925 		return (0);
   1926 
   1927 	result = select(sock + 1, &fds, (fd_set *)NULL, (fd_set *)NULL, &wait);
   1928 
   1929 	if (result == -1) {
   1930 		if (errno != EINTR) {
   1931 			Fprintf(stderr, "%s: select: %s\n", prog,
   1932 			    strerror(errno));
   1933 		}
   1934 	} else if (result > 0)
   1935 		cc = recvmsg(sock, msg, 0);
   1936 
   1937 	return (cc);
   1938 }
   1939 
   1940 /*
   1941  * Construct an Internet address representation. If the nflag has been supplied,
   1942  * give numeric value, otherwise try for symbolic name.
   1943  */
   1944 char *
   1945 inet_name(union any_in_addr *in, int family)
   1946 {
   1947 	char *cp;
   1948 	static boolean_t first = _B_TRUE;
   1949 	static char domain[NI_MAXHOST + 1];
   1950 	static char line[NI_MAXHOST + 1];	/* assuming		*/
   1951 				/* (NI_MAXHOST + 1) >= INET6_ADDRSTRLEN */
   1952 	char hbuf[NI_MAXHOST];
   1953 	socklen_t slen;
   1954 	struct sockaddr_in sin;
   1955 	struct sockaddr_in6 sin6;
   1956 	struct sockaddr *sa;
   1957 	int flags;
   1958 
   1959 	switch (family) {
   1960 	case AF_INET:
   1961 		slen = sizeof (struct sockaddr_in);
   1962 		sin.sin_addr = in->addr;
   1963 		sin.sin_port = 0;
   1964 		sa = (struct sockaddr *)&sin;
   1965 		break;
   1966 	case AF_INET6:
   1967 		slen = sizeof (struct sockaddr_in6);
   1968 		sin6.sin6_addr = in->addr6;
   1969 		sin6.sin6_port = 0;
   1970 		sin6.sin6_scope_id = 0;
   1971 		sa = (struct sockaddr *)&sin6;
   1972 		break;
   1973 	default:
   1974 		(void) snprintf(line, sizeof (line),
   1975 		    "<invalid address family>");
   1976 		return (line);
   1977 	}
   1978 	sa->sa_family = family;
   1979 
   1980 	if (first && !nflag) {
   1981 		/* find out the domain name */
   1982 		first = _B_FALSE;
   1983 		if (gethostname(domain, MAXHOSTNAMELEN) == 0 &&
   1984 		    (cp = strchr(domain, '.')) != NULL) {
   1985 			(void) strncpy(domain, cp + 1, sizeof (domain) - 1);
   1986 			domain[sizeof (domain) - 1] = '\0';
   1987 		} else {
   1988 			domain[0] = '\0';
   1989 		}
   1990 	}
   1991 
   1992 	flags = (nflag) ? NI_NUMERICHOST : NI_NAMEREQD;
   1993 	if (getnameinfo(sa, slen, hbuf, sizeof (hbuf), NULL, 0, flags) != 0) {
   1994 		if (inet_ntop(family, (const void *)&in->addr6,
   1995 		    hbuf, sizeof (hbuf)) == NULL)
   1996 			hbuf[0] = 0;
   1997 	} else if (!nflag && (cp = strchr(hbuf, '.')) != NULL &&
   1998 	    strcmp(cp + 1, domain) == 0) {
   1999 		*cp = '\0';
   2000 	}
   2001 	(void) strlcpy(line, hbuf, sizeof (line));
   2002 
   2003 	return (line);
   2004 }
   2005 
   2006 /*
   2007  * return the difference (in msec) between two time values
   2008  */
   2009 static double
   2010 deltaT(struct timeval *t1p, struct timeval *t2p)
   2011 {
   2012 	double dt;
   2013 
   2014 	dt = (double)(t2p->tv_sec - t1p->tv_sec) * 1000.0 +
   2015 	    (double)(t2p->tv_usec - t1p->tv_usec) / 1000.0;
   2016 	return (dt);
   2017 }
   2018 
   2019 /*
   2020  * Subtract 2 timeval structs:  out = out - in.
   2021  * Out is assumed to be >= in.
   2022  */
   2023 static void
   2024 tv_sub(struct timeval *out, struct timeval *in)
   2025 {
   2026 	if ((out->tv_usec -= in->tv_usec) < 0)   {
   2027 		--out->tv_sec;
   2028 		out->tv_usec += 1000000;
   2029 	}
   2030 	out->tv_sec -= in->tv_sec;
   2031 }
   2032 
   2033 /*
   2034  * record statistics
   2035  */
   2036 static void
   2037 record_stats(double rtt, int *nreceived, double *rttmin, double *rttmax,
   2038     double *rttsum, double *rttssq)
   2039 {
   2040 	if (*nreceived == 0) {
   2041 		*rttmin = rtt;
   2042 		*rttmax = rtt;
   2043 		*rttsum = rtt;
   2044 		*rttssq = rtt * rtt;
   2045 	} else {
   2046 		if (rtt < *rttmin)
   2047 			*rttmin = rtt;
   2048 
   2049 		if (rtt > *rttmax)
   2050 			*rttmax = rtt;
   2051 
   2052 		*rttsum += rtt;
   2053 		*rttssq += rtt * rtt;
   2054 	}
   2055 
   2056 	(*nreceived)++;
   2057 }
   2058 
   2059 /*
   2060  * display statistics
   2061  */
   2062 static void
   2063 print_stats(int ntransmitted, int nreceived, double rttmin, double rttmax,
   2064     double rttsum, double rttssq)
   2065 {
   2066 	double rttavg;			/* average round-trip time */
   2067 	double rttstd;			/* rtt standard deviation */
   2068 
   2069 	if (ntransmitted > 0 && ntransmitted >= nreceived) {
   2070 		int missed = ntransmitted - nreceived;
   2071 		double loss = 100 * (double)missed / (double)ntransmitted;
   2072 
   2073 		if (nreceived > 0) {
   2074 			rttavg = rttsum / nreceived;
   2075 			rttstd = rttssq - (rttavg * rttsum);
   2076 			rttstd = xsqrt(rttstd / nreceived);
   2077 
   2078 			Printf("  %.3f", rttmin);
   2079 			Printf("/%.3f", rttavg);
   2080 			Printf("/%.3f", rttmax);
   2081 
   2082 			Printf(" (%.3f) ms ", rttstd);
   2083 		}
   2084 
   2085 		Printf(" %d/%d pkts", nreceived, ntransmitted);
   2086 
   2087 		if (nreceived == 0)
   2088 			Printf(" (100%% loss)");
   2089 		else
   2090 			Printf(" (%.2g%% loss)", loss);
   2091 	}
   2092 }
   2093 
   2094 /*
   2095  * square root function
   2096  */
   2097 double
   2098 xsqrt(double y)
   2099 {
   2100 	double t, x;
   2101 
   2102 	if (y <= 0) {
   2103 		return (0.0);
   2104 	}
   2105 
   2106 	x = (y < 1.0) ? 1.0 : y;
   2107 	do {
   2108 		t = x;
   2109 		x = (t + (y/t))/2.0;
   2110 	} while (0 < x && x < t);
   2111 
   2112 	return (x);
   2113 }
   2114 
   2115 /*
   2116  * String to double with optional min and max.
   2117  */
   2118 static double
   2119 str2dbl(const char *str, const char *what, double mi, double ma)
   2120 {
   2121 	double val;
   2122 	char *ep;
   2123 
   2124 	errno = 0;
   2125 
   2126 	val = strtod(str, &ep);
   2127 	if (errno != 0 || *ep != '\0') {
   2128 		Fprintf(stderr, "%s: \"%s\" bad value for %s \n",
   2129 		    prog, str, what);
   2130 		exit(EXIT_FAILURE);
   2131 	}
   2132 	if (val < mi && mi >= 0) {
   2133 		Fprintf(stderr, "%s: %s must be >= %f\n", prog, what, mi);
   2134 		exit(EXIT_FAILURE);
   2135 	}
   2136 	if (val > ma && ma >= 0) {
   2137 		Fprintf(stderr, "%s: %s must be <= %f\n", prog, what, ma);
   2138 		exit(EXIT_FAILURE);
   2139 	}
   2140 	return (val);
   2141 }
   2142 
   2143 /*
   2144  * String to int with optional min and max. Handles decimal and hex.
   2145  */
   2146 static int
   2147 str2int(const char *str, const char *what, int mi, int ma)
   2148 {
   2149 	const char *cp;
   2150 	int val;
   2151 	char *ep;
   2152 
   2153 	errno = 0;
   2154 
   2155 	if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X')) {
   2156 		cp = str + 2;
   2157 		val = (int)strtol(cp, &ep, 16);
   2158 	} else {
   2159 		val = (int)strtol(str, &ep, 10);
   2160 	}
   2161 	if (errno != 0 || *ep != '\0') {
   2162 		Fprintf(stderr, "%s: \"%s\" bad value for %s \n",
   2163 		    prog, str, what);
   2164 		exit(EXIT_FAILURE);
   2165 	}
   2166 	if (val < mi && mi >= 0) {
   2167 		if (mi == 0) {
   2168 			Fprintf(stderr, "%s: %s must be >= %d\n",
   2169 			    prog, what, mi);
   2170 		} else {
   2171 			Fprintf(stderr, "%s: %s must be > %d\n",
   2172 			    prog, what, mi - 1);
   2173 		}
   2174 		exit(EXIT_FAILURE);
   2175 	}
   2176 	if (val > ma && ma >= 0) {
   2177 		Fprintf(stderr, "%s: %s must be <= %d\n", prog, what, ma);
   2178 		exit(EXIT_FAILURE);
   2179 	}
   2180 	return (val);
   2181 }
   2182 
   2183 /*
   2184  * This is the interrupt handler for SIGINT and SIGQUIT. It's completely handled
   2185  * where it jumps to.
   2186  */
   2187 static void
   2188 sig_handler(int sig)
   2189 {
   2190 	longjmp(env, sig);
   2191 }
   2192 
   2193 /*
   2194  * display the usage of traceroute
   2195  */
   2196 static void
   2197 usage(void)
   2198 {
   2199 	Fprintf(stderr, "Usage: %s [-adFIlnSvx] [-A address_family] "
   2200 	    "[-c traffic_class]\n"
   2201 	    "\t[-f first_hop] [-g gateway [-g gateway ...]| -r] [-i iface]\n"
   2202 	    "\t[-L flow_label] [-m max_hop] [-P pause_sec] [-p port] "
   2203 	    "[-Q max_timeout]\n"
   2204 	    "\t[-q nqueries] [-s src_addr] [-t tos] [-w wait_time] host "
   2205 	    "[packetlen]\n", prog);
   2206 	exit(EXIT_FAILURE);
   2207 }
   2208