1 /*-
2  * Copyright (c) 2007 Bruce M. Simpson
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 /*
28  * Regression test utility for RFC 3678 Advanced Multicast API in FreeBSD.
29  *
30  * TODO: Test the SSM paths.
31  * TODO: Support INET6. The code has been written to facilitate this later.
32  * TODO: Merge multicast socket option tests from ipsockopt.
33  */
34 
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 #include <sys/param.h>
39 #include <sys/types.h>
40 #include <sys/ioctl.h>
41 #include <sys/socket.h>
42 
43 #include <net/if.h>
44 #include <net/if_dl.h>
45 #include <netinet/in.h>
46 #include <arpa/inet.h>
47 #include <netdb.h>
48 
49 #include <assert.h>
50 #include <err.h>
51 #include <errno.h>
52 #include <getopt.h>
53 #include <libgen.h>
54 #include <pwd.h>
55 #include <setjmp.h>
56 #include <signal.h>
57 #include <stddef.h>
58 #include <stdio.h>
59 #include <stdlib.h>
60 #include <string.h>
61 #include <sysexits.h>
62 #include <time.h>
63 #include <unistd.h>
64 
65 #ifndef __SOCKUNION_DECLARED
66 union sockunion {
67 	struct sockaddr_storage	ss;
68 	struct sockaddr		sa;
69 	struct sockaddr_dl	sdl;
70 	struct sockaddr_in	sin;
71 #ifdef INET6
72 	struct sockaddr_in6	sin6;
73 #endif
74 };
75 typedef union sockunion sockunion_t;
76 #define __SOCKUNION_DECLARED
77 #endif /* __SOCKUNION_DECLARED */
78 
79 #define ADDRBUF_LEN		16
80 #define DEFAULT_GROUP_STR	"238.1.1.0"
81 #define DEFAULT_IFNAME		"lo0"
82 #define DEFAULT_IFADDR_STR	"127.0.0.1"
83 #define DEFAULT_PORT		6698
84 #define DEFAULT_TIMEOUT		0		/* don't wait for traffic */
85 #define RXBUFSIZE		2048
86 
87 static sockunion_t	 basegroup;
88 static const char	*basegroup_str = NULL;
89 static int		 dobindaddr = 0;
90 static int		 dodebug = 1;
91 static int		 doipv4 = 0;
92 static int		 domiscopts = 0;
93 static int		 dorandom = 0;
94 static int		 doreuseport = 0;
95 static int		 dossm = 0;
96 static int		 dossf = 0;
97 static int		 doverbose = 0;
98 static sockunion_t	 ifaddr;
99 static const char	*ifaddr_str = NULL;
100 static uint32_t		 ifindex = 0;
101 static const char	*ifname = NULL;
102 struct in_addr		*ipv4_sources = NULL;
103 static jmp_buf		 jmpbuf;
104 static size_t		 nmcastgroups = IP_MAX_MEMBERSHIPS;
105 static size_t		 nmcastsources = 0;
106 static uint16_t		 portno = DEFAULT_PORT;
107 static char		*progname = NULL;
108 struct sockaddr_storage	*ss_sources = NULL;
109 static uint32_t		 timeout = 0;
110 
111 static int	do_asm_ipv4(void);
112 static int	do_asm_pim(void);
113 #ifdef notyet
114 static int	do_misc_opts(void);
115 #endif
116 static int	do_ssf_ipv4(void);
117 static int	do_ssf_pim(void);
118 static int	do_ssm_ipv4(void);
119 static int	do_ssm_pim(void);
120 static int	open_and_bind_socket(sockunion_t *);
121 static int	recv_loop_with_match(int, sockunion_t *, sockunion_t *);
122 static void	signal_handler(int);
123 static void	usage(void);
124 
125 /*
126  * Test the IPv4 set/getipv4sourcefilter() libc API functions.
127  * Build a single socket.
128  * Join a source group.
129  * Repeatedly change the source filters via setipv4sourcefilter.
130  * Read it back with getipv4sourcefilter up to IP_MAX_SOURCES
131  * and check for inconsistency.
132  */
133 static int
134 do_ssf_ipv4(void)
135 {
136 
137 	fprintf(stderr, "not yet implemented\n");
138 	return (0);
139 }
140 
141 /*
142  * Test the protocol-independent set/getsourcefilter() functions.
143  */
144 static int
145 do_ssf_pim(void)
146 {
147 
148 	fprintf(stderr, "not yet implemented\n");
149 	return (0);
150 }
151 
152 /*
153  * Test the IPv4 ASM API.
154  * Repeatedly join, block sources, unblock and leave groups.
155  */
156 static int
157 do_asm_ipv4(void)
158 {
159 	int			 error;
160 	char			 gaddrbuf[ADDRBUF_LEN];
161 	int			 i;
162 	sockunion_t		 laddr;
163 	struct ip_mreq		 mreq;
164 	struct ip_mreq_source	 mreqs;
165 	in_addr_t		 ngroupbase;
166 	char			 saddrbuf[ADDRBUF_LEN];
167 	int			 sock;
168 	sockunion_t		 tmpgroup;
169 	sockunion_t		 tmpsource;
170 
171 	memset(&mreq, 0, sizeof(struct ip_mreq));
172 	memset(&mreqs, 0, sizeof(struct ip_mreq_source));
173 	memset(&laddr, 0, sizeof(sockunion_t));
174 
175 	if (dobindaddr) {
176 		laddr = ifaddr;
177 	} else {
178 		laddr.sin.sin_family = AF_INET;
179 		laddr.sin.sin_len = sizeof(struct sockaddr_in);
180 		laddr.sin.sin_addr.s_addr = INADDR_ANY;
181 	}
182 	laddr.sin.sin_port = htons(portno);
183 
184 	tmpgroup = basegroup;
185 	ngroupbase = ntohl(basegroup.sin.sin_addr.s_addr) + 1;	/* XXX */
186 	tmpgroup.sin.sin_addr.s_addr = htonl(ngroupbase);
187 
188 	sock = open_and_bind_socket(&laddr);
189 	if (sock == -1)
190 		return (EX_OSERR);
191 
192 	for (i = 0; i < (signed)nmcastgroups; i++) {
193 		mreq.imr_multiaddr.s_addr = htonl((ngroupbase + i));
194 		mreq.imr_interface = ifaddr.sin.sin_addr;
195 		if (doverbose) {
196 			inet_ntop(AF_INET, &mreq.imr_multiaddr, gaddrbuf,
197 			    sizeof(gaddrbuf));
198 			fprintf(stderr, "IP_ADD_MEMBERSHIP %s %s\n",
199 			    gaddrbuf, inet_ntoa(mreq.imr_interface));
200 		}
201 		error = setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,
202 		    &mreq, sizeof(struct ip_mreq));
203 		if (error < 0) {
204 			warn("setsockopt IP_ADD_MEMBERSHIP");
205 			close(sock);
206 			return (EX_OSERR);
207 		}
208 	}
209 
210 	/*
211 	 * If no test sources auto-generated or specified on command line,
212 	 * skip source filter portion of ASM test.
213 	*/
214 	if (nmcastsources == 0)
215 		goto skipsources;
216 
217 	/*
218 	 * Begin blocking sources on the first group chosen.
219 	 */
220 	for (i = 0; i < (signed)nmcastsources; i++) {
221 		mreqs.imr_multiaddr = tmpgroup.sin.sin_addr;
222 		mreqs.imr_interface = ifaddr.sin.sin_addr;
223 		mreqs.imr_sourceaddr = ipv4_sources[i];
224 		if (doverbose) {
225 			inet_ntop(AF_INET, &mreqs.imr_multiaddr, gaddrbuf,
226 			    sizeof(gaddrbuf));
227 			inet_ntop(AF_INET, &mreqs.imr_sourceaddr, saddrbuf,
228 			    sizeof(saddrbuf));
229 			fprintf(stderr, "IP_BLOCK_SOURCE %s %s %s\n",
230 			    gaddrbuf, inet_ntoa(mreqs.imr_interface),
231 			    saddrbuf);
232 		}
233 		error = setsockopt(sock, IPPROTO_IP, IP_BLOCK_SOURCE, &mreqs,
234 		    sizeof(struct ip_mreq_source));
235 		if (error < 0) {
236 			warn("setsockopt IP_BLOCK_SOURCE");
237 			close(sock);
238 			return (EX_OSERR);
239 		}
240 	}
241 
242 	/*
243 	 * Choose the first group and source for a match.
244 	 * Enter the I/O loop.
245 	 */
246 	memset(&tmpsource, 0, sizeof(sockunion_t));
247 	tmpsource.sin.sin_family = AF_INET;
248 	tmpsource.sin.sin_len = sizeof(struct sockaddr_in);
249 	tmpsource.sin.sin_addr = ipv4_sources[0];
250 
251 	error = recv_loop_with_match(sock, &tmpgroup, &tmpsource);
252 
253 	/*
254 	 * Unblock sources.
255 	 */
256 	for (i = nmcastsources-1; i >= 0; i--) {
257 		mreqs.imr_multiaddr = tmpgroup.sin.sin_addr;
258 		mreqs.imr_interface = ifaddr.sin.sin_addr;
259 		mreqs.imr_sourceaddr = ipv4_sources[i];
260 		if (doverbose) {
261 			inet_ntop(AF_INET, &mreqs.imr_multiaddr, gaddrbuf,
262 			    sizeof(gaddrbuf));
263 			inet_ntop(AF_INET, &mreqs.imr_sourceaddr, saddrbuf,
264 			    sizeof(saddrbuf));
265 			fprintf(stderr, "IP_UNBLOCK_SOURCE %s %s %s\n",
266 			    gaddrbuf, inet_ntoa(mreqs.imr_interface),
267 			    saddrbuf);
268 		}
269 		error = setsockopt(sock, IPPROTO_IP, IP_UNBLOCK_SOURCE, &mreqs,
270 		    sizeof(struct ip_mreq_source));
271 		if (error < 0) {
272 			warn("setsockopt IP_UNBLOCK_SOURCE");
273 			close(sock);
274 			return (EX_OSERR);
275 		}
276 	}
277 
278 skipsources:
279 	/*
280 	 * Leave groups.
281 	 */
282 	for (i = nmcastgroups-1; i >= 0; i--) {
283 		mreq.imr_multiaddr.s_addr = htonl((ngroupbase + i));
284 		mreq.imr_interface = ifaddr.sin.sin_addr;
285 		if (doverbose) {
286 			inet_ntop(AF_INET, &mreq.imr_multiaddr, gaddrbuf,
287 			    sizeof(gaddrbuf));
288 			fprintf(stderr, "IP_DROP_MEMBERSHIP %s %s\n",
289 			    gaddrbuf, inet_ntoa(mreq.imr_interface));
290 		}
291 		error = setsockopt(sock, IPPROTO_IP, IP_DROP_MEMBERSHIP,
292 		    &mreq, sizeof(struct ip_mreq));
293 		if (error < 0) {
294 			warn("setsockopt IP_DROP_MEMBERSHIP");
295 			close(sock);
296 			return (EX_OSERR);
297 		}
298 	}
299 
300 	return (0);
301 }
302 
303 static int
304 do_asm_pim(void)
305 {
306 
307 	fprintf(stderr, "not yet implemented\n");
308 	return (0);
309 }
310 
311 #ifdef notyet
312 /*
313  * Test misceallaneous IPv4 options.
314  */
315 static int
316 do_misc_opts(void)
317 {
318 	int sock;
319 
320 	sock = open_and_bind_socket(NULL);
321 	if (sock == -1)
322 		return (EX_OSERR);
323 	test_ip_uchar(sock, socktypename, IP_MULTICAST_TTL,
324 	    "IP_MULTICAST_TTL", 1);
325 	close(sock);
326 
327 	sock = open_and_bind_socket(NULL);
328 	if (sock == -1)
329 		return (EX_OSERR);
330 	test_ip_boolean(sock, socktypename, IP_MULTICAST_LOOP,
331 	    "IP_MULTICAST_LOOP", 1, BOOLEAN_ANYONE);
332 	close(sock);
333 
334 	return (0);
335 }
336 #endif
337 
338 /*
339  * Test the IPv4 SSM API.
340  */
341 static int
342 do_ssm_ipv4(void)
343 {
344 
345 	fprintf(stderr, "not yet implemented\n");
346 	return (0);
347 }
348 
349 /*
350  * Test the protocol-independent SSM API with IPv4 addresses.
351  */
352 static int
353 do_ssm_pim(void)
354 {
355 
356 	fprintf(stderr, "not yet implemented\n");
357 	return (0);
358 }
359 
360 int
361 main(int argc, char *argv[])
362 {
363 	struct addrinfo		 aih;
364 	struct addrinfo		*aip;
365 	int			 ch;
366 	int			 error;
367 	int			 exitval;
368 	size_t			 i;
369 	struct in_addr		*pina;
370 	struct sockaddr_storage	*pbss;
371 
372 	ifname = DEFAULT_IFNAME;
373 	ifaddr_str = DEFAULT_IFADDR_STR;
374 	basegroup_str = DEFAULT_GROUP_STR;
375 	ifname = DEFAULT_IFNAME;
376 	portno = DEFAULT_PORT;
377 	basegroup.ss.ss_family = AF_UNSPEC;
378 	ifaddr.ss.ss_family = AF_UNSPEC;
379 
380 	progname = basename(argv[0]);
381 	while ((ch = getopt(argc, argv, "4bg:i:I:mM:p:rsS:tT:v")) != -1) {
382 		switch (ch) {
383 		case '4':
384 			doipv4 = 1;
385 			break;
386 		case 'b':
387 			dobindaddr = 1;
388 			break;
389 		case 'g':
390 			basegroup_str = optarg;
391 			break;
392 		case 'i':
393 			ifname = optarg;
394 			break;
395 		case 'I':
396 			ifaddr_str = optarg;
397 			break;
398 		case 'm':
399 			usage();	/* notyet */
400 			/*NOTREACHED*/
401 			domiscopts = 1;
402 			break;
403 		case 'M':
404 			nmcastgroups = atoi(optarg);
405 			break;
406 		case 'p':
407 			portno = atoi(optarg);
408 			break;
409 		case 'r':
410 			doreuseport = 1;
411 			break;
412 		case 'S':
413 			nmcastsources = atoi(optarg);
414 			break;
415 		case 's':
416 			dossm = 1;
417 			break;
418 		case 't':
419 			dossf = 1;
420 			break;
421 		case 'T':
422 			timeout = atoi(optarg);
423 			break;
424 		case 'v':
425 			doverbose = 1;
426 			break;
427 		default:
428 			usage();
429 			break;
430 			/*NOTREACHED*/
431 		}
432 	}
433 	argc -= optind;
434 	argv += optind;
435 
436 	memset(&aih, 0, sizeof(struct addrinfo));
437 	aih.ai_flags = AI_NUMERICHOST | AI_PASSIVE;
438 	aih.ai_family = PF_INET;
439 	aih.ai_socktype = SOCK_DGRAM;
440 	aih.ai_protocol = IPPROTO_UDP;
441 
442 	/*
443 	 * Fill out base group.
444 	 */
445 	aip = NULL;
446 	error = getaddrinfo(basegroup_str, NULL, &aih, &aip);
447 	if (error != 0) {
448 		fprintf(stderr, "%s: getaddrinfo: %s\n", progname,
449 		    gai_strerror(error));
450 		exit(EX_USAGE);
451 	}
452 	memcpy(&basegroup, aip->ai_addr, aip->ai_addrlen);
453 	if (dodebug) {
454 		fprintf(stderr, "debug: gai thinks %s is %s\n",
455 		    basegroup_str, inet_ntoa(basegroup.sin.sin_addr));
456 	}
457 	freeaddrinfo(aip);
458 
459 	assert(basegroup.ss.ss_family == AF_INET);
460 
461 	/*
462 	 * If user specified interface as an address, and protocol
463 	 * specific APIs were selected, parse it.
464 	 * Otherwise, parse interface index from name if protocol
465 	 * independent APIs were selected (the default).
466 	 */
467 	if (doipv4) {
468 		if (ifaddr_str == NULL) {
469 			warnx("required argument missing: ifaddr");
470 			usage();
471 			/* NOTREACHED */
472 		}
473 		aip = NULL;
474 		error = getaddrinfo(ifaddr_str, NULL, &aih, &aip);
475 		if (error != 0) {
476 			fprintf(stderr, "%s: getaddrinfo: %s\n", progname,
477 			    gai_strerror(error));
478 			exit(EX_USAGE);
479 		}
480 		memcpy(&ifaddr, aip->ai_addr, aip->ai_addrlen);
481 		if (dodebug) {
482 			fprintf(stderr, "debug: gai thinks %s is %s\n",
483 			    ifaddr_str, inet_ntoa(ifaddr.sin.sin_addr));
484 		}
485 		freeaddrinfo(aip);
486 	}
487 
488 	if (!doipv4) {
489 		if (ifname == NULL) {
490 			warnx("required argument missing: ifname");
491 			usage();
492 			/* NOTREACHED */
493 		}
494 		ifindex = if_nametoindex(ifname);
495 		if (ifindex == 0)
496 			err(EX_USAGE, "if_nametoindex");
497 	}
498 
499 	/*
500 	 * Introduce randomness into group base if specified.
501 	 */
502 	if (dorandom) {
503 		in_addr_t ngroupbase;
504 
505 		srandomdev();
506 		ngroupbase = ntohl(basegroup.sin.sin_addr.s_addr);
507 		ngroupbase |= ((random() % ((1 << 11) - 1)) << 16);
508 		basegroup.sin.sin_addr.s_addr = htonl(ngroupbase);
509 	}
510 
511 	if (argc > 0) {
512 		nmcastsources = argc;
513 		if (doipv4) {
514 			ipv4_sources = calloc(nmcastsources,
515 			    sizeof(struct in_addr));
516 			if (ipv4_sources == NULL) {
517 				exitval = EX_OSERR;
518 				goto out;
519 			}
520 		} else {
521 			ss_sources = calloc(nmcastsources,
522 			    sizeof(struct sockaddr_storage));
523 			if (ss_sources == NULL) {
524 				exitval = EX_OSERR;
525 				goto out;
526 			}
527 		}
528 	}
529 
530 	/*
531 	 * Parse source list, if any were specified on the command line.
532 	 */
533 	assert(aih.ai_family == PF_INET);
534 	pbss = ss_sources;
535 	pina = ipv4_sources;
536 	for (i = 0; i < (size_t)argc; i++) {
537 		aip = NULL;
538 		error = getaddrinfo(argv[i], NULL, &aih, &aip);
539 		if (error != 0) {
540 			fprintf(stderr, "getaddrinfo: %s\n",
541 			    gai_strerror(error));
542 			exitval = EX_USAGE;
543 			goto out;
544 		}
545 		if (doipv4) {
546 			struct sockaddr_in *sin =
547 			    (struct sockaddr_in *)aip->ai_addr;
548 			*pina++ = sin->sin_addr;
549 		} else {
550 			memcpy(pbss++, aip->ai_addr, aip->ai_addrlen);
551 		}
552 		freeaddrinfo(aip);
553 	}
554 
555 	/*
556 	 * Perform the regression tests which the user requested.
557 	 */
558 #ifdef notyet
559 	if (domiscopts) {
560 		exitval = do_misc_opts();
561 		if (exitval)
562 			goto out;
563 	}
564 #endif
565 	if (doipv4) {
566 		/* IPv4 protocol specific API tests */
567 		if (dossm) {
568 			/* Source-specific multicast */
569 			exitval = do_ssm_ipv4();
570 			if (exitval)
571 				goto out;
572 			if (dossf) {
573 				/* Do setipvsourcefilter() too */
574 				exitval = do_ssf_ipv4();
575 			}
576 		} else {
577 			/* Any-source multicast */
578 			exitval = do_asm_ipv4();
579 		}
580 	} else {
581 		/* Protocol independent API tests */
582 		if (dossm) {
583 			/* Source-specific multicast */
584 			exitval = do_ssm_pim();
585 			if (exitval)
586 				goto out;
587 			if (dossf) {
588 				/* Do setsourcefilter() too */
589 				exitval = do_ssf_pim();
590 			}
591 		} else {
592 			/* Any-source multicast */
593 			exitval = do_asm_pim();
594 		}
595 	}
596 
597 out:
598 	if (ipv4_sources != NULL)
599 		free(ipv4_sources);
600 
601 	if (ss_sources != NULL)
602 		free(ss_sources);
603 
604 	exit(exitval);
605 }
606 
607 static int
608 open_and_bind_socket(sockunion_t *bsu)
609 {
610 	int	 error, optval, sock;
611 
612 	sock = -1;
613 
614 	sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
615 	if (sock == -1) {
616 		warn("socket");
617 		return (-1);
618 	}
619 
620 	if (doreuseport) {
621 		optval = 1;
622 		if (setsockopt(sock, SOL_SOCKET, SO_REUSEPORT, &optval,
623 		    sizeof(optval)) < 0) {
624 			warn("setsockopt SO_REUSEPORT");
625 			close(sock);
626 			return (-1);
627 		}
628 	}
629 
630 	if (bsu != NULL) {
631 		error = bind(sock, &bsu->sa, bsu->sa.sa_len);
632 		if (error == -1) {
633 			warn("bind");
634 			close(sock);
635 			return (-1);
636 		}
637 	}
638 
639 	return (sock);
640 }
641 
642 /*
643  * Protocol-agnostic multicast I/O loop.
644  *
645  * Wait for 'timeout' seconds looking for traffic on group, so that manual
646  * or automated regression tests (possibly running on another host) have an
647  * opportunity to transmit within the group to test source filters.
648  *
649  * If the filter failed, this loop will report if we received traffic
650  * from the source we elected to monitor.
651  */
652 static int
653 recv_loop_with_match(int sock, sockunion_t *group, sockunion_t *source)
654 {
655 	int		 error;
656 	sockunion_t	 from;
657 	char		 groupname[NI_MAXHOST];
658 	ssize_t		 len;
659 	size_t		 npackets;
660 	int		 jmpretval;
661 	char		 rxbuf[RXBUFSIZE];
662 	char		 sourcename[NI_MAXHOST];
663 
664 	assert(source->sa.sa_family == AF_INET);
665 
666 	/*
667 	 * Return immediately if we don't need to wait for traffic.
668 	 */
669 	if (timeout == 0)
670 		return (0);
671 
672 	error = getnameinfo(&group->sa, group->sa.sa_len, groupname,
673 	    NI_MAXHOST, NULL, 0, NI_NUMERICHOST);
674 	if (error) {
675 		fprintf(stderr, "getnameinfo: %s\n", gai_strerror(error));
676 		return (error);
677 	}
678 
679 	error = getnameinfo(&source->sa, source->sa.sa_len, sourcename,
680 	    NI_MAXHOST, NULL, 0, NI_NUMERICHOST);
681 	if (error) {
682 		fprintf(stderr, "getnameinfo: %s\n", gai_strerror(error));
683 		return (error);
684 	}
685 
686 	fprintf(stdout,
687 	    "Waiting %d seconds for inbound traffic on group %s\n"
688 	    "Expecting no traffic from blocked source: %s\n",
689 	    (int)timeout, groupname, sourcename);
690 
691 	signal(SIGINT, signal_handler);
692 	signal(SIGALRM, signal_handler);
693 
694 	error = 0;
695 	npackets = 0;
696 	alarm(timeout);
697 	while (0 == (jmpretval = setjmp(jmpbuf))) {
698 		len = recvfrom(sock, rxbuf, RXBUFSIZE, 0, &from.sa,
699 		    (socklen_t *)&from.sa.sa_len);
700 		if (dodebug) {
701 			fprintf(stderr, "debug: packet received from %s\n",
702 			    inet_ntoa(from.sin.sin_addr));
703 		}
704 		if (source &&
705 		    source->sin.sin_addr.s_addr == from.sin.sin_addr.s_addr)
706 			break;
707 		npackets++;
708 	}
709 
710 	if (doverbose) {
711 		fprintf(stderr, "Number of datagrams received from "
712 		    "non-blocked sources: %d\n", (int)npackets);
713 	}
714 
715 	switch (jmpretval) {
716 	case SIGALRM:	/* ok */
717 		break;
718 	case SIGINT:	/* go bye bye */
719 		fprintf(stderr, "interrupted\n");
720 		error = 20;
721 		break;
722 	case 0:		/* Broke out of loop; saw a bad source. */
723 		fprintf(stderr, "FAIL: got packet from blocked source\n");
724 		error = EX_IOERR;
725 		break;
726 	default:
727 		warnx("recvfrom");
728 		error = EX_OSERR;
729 		break;
730 	}
731 
732 	signal(SIGINT, SIG_DFL);
733 	signal(SIGALRM, SIG_DFL);
734 
735 	return (error);
736 }
737 
738 static void
739 signal_handler(int signo)
740 {
741 
742 	longjmp(jmpbuf, signo);
743 }
744 
745 static void
746 usage(void)
747 {
748 
749 	fprintf(stderr, "\nIP multicast regression test utility\n");
750 	fprintf(stderr,
751 "usage: %s [-4] [-b] [-g groupaddr] [-i ifname] [-I ifaddr] [-m]\n"
752 "       [-M ngroups] [-p portno] [-r] [-R] [-s] [-S nsources] [-t] [-T timeout]\n"
753 "       [-v] [blockaddr ...]\n\n", progname);
754 	fprintf(stderr, "-4: Use IPv4 API "
755 	                "(default: Use protocol-independent API)\n");
756 	fprintf(stderr, "-b: bind listening socket to ifaddr "
757 	    "(default: INADDR_ANY)\n");
758 	fprintf(stderr, "-g: Base IPv4 multicast group to join (default: %s)\n",
759 	    DEFAULT_GROUP_STR);
760 	fprintf(stderr, "-i: interface for multicast joins (default: %s)\n",
761 	    DEFAULT_IFNAME);
762 	fprintf(stderr, "-I: IPv4 address to join groups on, if using IPv4 "
763 	    "API\n    (default: %s)\n", DEFAULT_IFADDR_STR);
764 #ifdef notyet
765 	fprintf(stderr, "-m: Test misc IPv4 multicast socket options "
766 	    "(default: off)\n");
767 #endif
768 	fprintf(stderr, "-M: Number of multicast groups to join "
769 	    "(default: %d)\n", (int)nmcastgroups);
770 	fprintf(stderr, "-p: Set local and remote port (default: %d)\n",
771 	    DEFAULT_PORT);
772 	fprintf(stderr, "-r: Set SO_REUSEPORT on (default: off)\n");
773 	fprintf(stderr, "-R: Randomize groups/sources (default: off)\n");
774 	fprintf(stderr, "-s: Test source-specific API "
775 	    "(default: test any-source API)\n");
776 	fprintf(stderr, "-S: Number of multicast sources to generate if\n"
777 	    "    none specified on command line (default: %d)\n",
778 	    (int)nmcastsources);
779 	fprintf(stderr, "-t: Test get/setNsourcefilter() (default: off)\n");
780 	fprintf(stderr, "-T: Timeout to wait for blocked traffic on first "
781 	    "group (default: %d)\n", DEFAULT_TIMEOUT);
782 	fprintf(stderr, "-v: Be verbose (default: off)\n");
783 	fprintf(stderr, "\nRemaining arguments are treated as a list of IPv4 "
784 	    "sources to filter.\n\n");
785 
786 	exit(EX_USAGE);
787 }
788