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