path: root/usr.sbin/ifmcstat/ifmcstat.c

/*	$KAME: ifmcstat.c,v 1.48 2006/11/15 05:13:59 itojun Exp $	*/

/*
 * Copyright (c) 2007-2009 Bruce Simpson.
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/types.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/queue.h>

#include <net/if.h>
#include <net/if_var.h>
#include <net/if_types.h>
#include <net/if_dl.h>
#include <net/route.h>

#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/igmp.h>
#ifdef HAVE_IGMPV3
# include <netinet/in_msf.h>
#endif
#define KERNEL
# include <netinet/if_ether.h>
#undef KERNEL
#define _KERNEL
# include <sys/sysctl.h>
# include <netinet/igmp_var.h>
#undef _KERNEL

#ifdef INET6
# ifdef HAVE_MLDV2
#  include <netinet6/in6_msf.h>
# endif
#include <netinet/icmp6.h>
#define _KERNEL
# include <netinet6/mld6_var.h>
#undef _KERNEL
#endif /* INET6 */

#include <arpa/inet.h>
#include <netdb.h>

#include <stddef.h>
#include <stdarg.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <ctype.h>
#include <err.h>
#include <fcntl.h>
#include <kvm.h>
#include <limits.h>
#include <ifaddrs.h>
#include <nlist.h>
#include <sysexits.h>
#include <unistd.h>

/* XXX: This file currently assumes INET and KVM support in the base system. */
#ifndef INET
#define INET
#endif

union sockunion {
	struct sockaddr_storage	ss;
	struct sockaddr		sa;
	struct sockaddr_dl	sdl;
#ifdef INET
	struct sockaddr_in	sin;
#endif
#ifdef INET6
	struct sockaddr_in6	sin6;
#endif
};
typedef union sockunion sockunion_t;

uint32_t	ifindex = 0;
int		af = AF_UNSPEC;
int		vflag = 0;

#define	sa_equal(a1, a2)	\
	(bcmp((a1), (a2), ((a1))->sa_len) == 0)

#define	sa_dl_equal(a1, a2)	\
	((((struct sockaddr_dl *)(a1))->sdl_len ==			\
	 ((struct sockaddr_dl *)(a2))->sdl_len) &&			\
	 (bcmp(LLADDR((struct sockaddr_dl *)(a1)),			\
	       LLADDR((struct sockaddr_dl *)(a2)),			\
	       ((struct sockaddr_dl *)(a1))->sdl_alen) == 0))

/*
 * Most of the code in this utility is to support the use of KVM for
 * post-mortem debugging of the multicast code.
 */
#ifdef WITH_KVM

#ifdef INET
static void		if_addrlist(struct ifaddr *);
static struct in_multi *
			in_multientry(struct in_multi *);
#ifdef HAVE_IGMPV3
static void		in_addr_slistentry(struct in_addr_slist *, char *);
#endif
#endif /* INET */

#ifdef INET6
static void		if6_addrlist(struct ifaddr *);
static struct in6_multi *
			in6_multientry(struct in6_multi *);
#ifdef HAVE_MLDV2
static void		in6_addr_slistentry(struct in6_addr_slist *, char *);
#endif
#endif /* INET6 */

static void		kread(u_long, void *, int);
static void		ll_addrlist(struct ifaddr *);

static int		ifmcstat_kvm(const char *kernel, const char *core);

#define	KREAD(addr, buf, type) \
	kread((u_long)addr, (void *)buf, sizeof(type))

kvm_t	*kvmd;
struct	nlist nl[] = {
	{ "_ifnet", 0, 0, 0, 0, },
	{ "", 0, 0, 0, 0, },
};
#define	N_IFNET	0

#endif /* WITH_KVM */

static int		ifmcstat_getifmaddrs(void);
#ifdef INET6
static const char *	inet6_n2a(struct in6_addr *);
#endif
int			main(int, char **);

static void
usage()
{

	fprintf(stderr,
	    "usage: ifmcstat [-i interface] [-f address family]"
	    " [-v]"
#ifdef WITH_KVM
	    " [-M core] [-N system]"
#endif
	    "\n");
	exit(EX_USAGE);
}

int
main(int argc, char **argv)
{
	int c, error;
#ifdef WITH_KVM
	const char *kernel = NULL;
	const char *core = NULL;
#endif

	while ((c = getopt(argc, argv, "i:f:vM:N:")) != -1) {
		switch (c) {
		case 'i':
			if ((ifindex = if_nametoindex(optarg)) == 0) {
				fprintf(stderr, "%s: unknown interface\n",
				    optarg);
				exit(1);
			}
			break;

		case 'f':
#ifdef INET
			if (strcmp(optarg, "inet") == 0) {
				af = AF_INET;
				break;
			}
#endif
#ifdef INET6
			if (strcmp(optarg, "inet6") == 0) {
				af = AF_INET6;
				break;
			}
#endif
			if (strcmp(optarg, "link") == 0) {
				af = AF_LINK;
				break;
			}
			fprintf(stderr, "%s: unknown address family\n", optarg);
			exit(1);
			/*NOTREACHED*/
			break;

		case 'v':
			vflag = 1;
			break;

#ifdef WITH_KVM
		case 'M':
			core = strdup(optarg);
			break;

		case 'N':
			kernel = strdup(optarg);
			break;
#endif

		default:
			usage();
			break;
			/*NOTREACHED*/
		}
	}

	if (af == AF_LINK && vflag)
		usage();

#ifdef WITH_KVM
	error = ifmcstat_kvm(kernel, core);
	/*
	 * If KVM failed, and user did not explicitly specify a core file,
	 * try the sysctl backend.
	 */
	if (error != 0 && (core == NULL && kernel == NULL))
#endif
	error = ifmcstat_getifmaddrs();
	if (error != 0)
		exit(1);

	exit(0);
	/*NOTREACHED*/
}

#ifdef WITH_KVM

static int
ifmcstat_kvm(const char *kernel, const char *core)
{
	char	buf[_POSIX2_LINE_MAX], ifname[IFNAMSIZ];
	struct	ifnet	*ifp, *nifp, ifnet;

	if ((kvmd = kvm_openfiles(kernel, core, NULL, O_RDONLY, buf)) ==
	    NULL) {
		perror("kvm_openfiles");
		return (-1);
	}
	if (kvm_nlist(kvmd, nl) < 0) {
		perror("kvm_nlist");
		return (-1);
	}
	if (nl[N_IFNET].n_value == 0) {
		printf("symbol %s not found\n", nl[N_IFNET].n_name);
		return (-1);
	}
	KREAD(nl[N_IFNET].n_value, &ifp, struct ifnet *);
	while (ifp) {
		KREAD(ifp, &ifnet, struct ifnet);
		nifp = ifnet.if_link.tqe_next;
		if (ifindex && ifindex != ifnet.if_index)
			goto next;
	
		printf("%s:\n", if_indextoname(ifnet.if_index, ifname));
#ifdef INET
		if_addrlist(TAILQ_FIRST(&ifnet.if_addrhead));
#endif
#ifdef INET6
		if6_addrlist(TAILQ_FIRST(&ifnet.if_addrhead));
#endif
		if (vflag)
			ll_addrlist(TAILQ_FIRST(&ifnet.if_addrhead));
next:
		ifp = nifp;
	}

	return (0);
}

static void
kread(u_long addr, void *buf, int len)
{

	if (kvm_read(kvmd, addr, buf, len) != len) {
		perror("kvm_read");
		exit(1);
	}
}

static void
ll_addrlist(struct ifaddr *ifap)
{
	char addrbuf[NI_MAXHOST];
	struct ifaddr ifa;
	struct sockaddr sa;
	struct sockaddr_dl sdl;
	struct ifaddr *ifap0;
	int error;

	if (af && af != AF_LINK)
		return;

	ifap0 = ifap;
	while (ifap) {
		KREAD(ifap, &ifa, struct ifaddr);
		if (ifa.ifa_addr == NULL)
			goto nextifap;
		KREAD(ifa.ifa_addr, &sa, struct sockaddr);
		if (sa.sa_family != PF_LINK)
			goto nextifap;
		KREAD(ifa.ifa_addr, &sdl, struct sockaddr_dl);
		if (sdl.sdl_alen == 0)
			goto nextifap;
		addrbuf[0] = '\0';
		error = getnameinfo((struct sockaddr *)&sdl, sdl.sdl_len,
		    addrbuf, sizeof(addrbuf), NULL, 0, NI_NUMERICHOST);
		printf("\tlink %s\n", addrbuf);
	nextifap:
		ifap = ifa.ifa_link.tqe_next;
	}
	if (ifap0) {
		struct ifnet ifnet;
		struct ifmultiaddr ifm, *ifmp = 0;

		KREAD(ifap0, &ifa, struct ifaddr);
		KREAD(ifa.ifa_ifp, &ifnet, struct ifnet);
		if (TAILQ_FIRST(&ifnet.if_multiaddrs))
			ifmp = TAILQ_FIRST(&ifnet.if_multiaddrs);
		while (ifmp) {
			KREAD(ifmp, &ifm, struct ifmultiaddr);
			if (ifm.ifma_addr == NULL)
				goto nextmulti;
			KREAD(ifm.ifma_addr, &sa, struct sockaddr);
			if (sa.sa_family != AF_LINK)
				goto nextmulti;
			KREAD(ifm.ifma_addr, &sdl, struct sockaddr_dl);
			addrbuf[0] = '\0';
			error = getnameinfo((struct sockaddr *)&sdl,
			    sdl.sdl_len, addrbuf, sizeof(addrbuf),
			    NULL, 0, NI_NUMERICHOST);
			printf("\t\tgroup %s refcnt %d\n",
			    addrbuf, ifm.ifma_refcount);
		nextmulti:
			ifmp = TAILQ_NEXT(&ifm, ifma_link);
		}
	}
}

#ifdef INET6

static void
if6_addrlist(struct ifaddr *ifap)
{
	struct ifaddr ifa;
	struct sockaddr sa;
	struct in6_ifaddr if6a;
	struct ifaddr *ifap0;

	if (af && af != AF_INET6)
		return;
	ifap0 = ifap;
	while (ifap) {
		KREAD(ifap, &ifa, struct ifaddr);
		if (ifa.ifa_addr == NULL)
			goto nextifap;
		KREAD(ifa.ifa_addr, &sa, struct sockaddr);
		if (sa.sa_family != PF_INET6)
			goto nextifap;
		KREAD(ifap, &if6a, struct in6_ifaddr);
		printf("\tinet6 %s\n", inet6_n2a(&if6a.ia_addr.sin6_addr));
	nextifap:
		ifap = ifa.ifa_link.tqe_next;
	}
	if (ifap0) {
		struct ifnet ifnet;
		struct ifmultiaddr ifm, *ifmp = 0;
		struct sockaddr_dl sdl;

		KREAD(ifap0, &ifa, struct ifaddr);
		KREAD(ifa.ifa_ifp, &ifnet, struct ifnet);
		if (TAILQ_FIRST(&ifnet.if_multiaddrs))
			ifmp = TAILQ_FIRST(&ifnet.if_multiaddrs);
		while (ifmp) {
			KREAD(ifmp, &ifm, struct ifmultiaddr);
			if (ifm.ifma_addr == NULL)
				goto nextmulti;
			KREAD(ifm.ifma_addr, &sa, struct sockaddr);
			if (sa.sa_family != AF_INET6)
				goto nextmulti;
			(void)in6_multientry((struct in6_multi *)
					     ifm.ifma_protospec);
			if (ifm.ifma_lladdr == 0)
				goto nextmulti;
			KREAD(ifm.ifma_lladdr, &sdl, struct sockaddr_dl);
			printf("\t\t\tmcast-macaddr %s refcnt %d\n",
			       ether_ntoa((struct ether_addr *)LLADDR(&sdl)),
			       ifm.ifma_refcount);
		    nextmulti:
			ifmp = TAILQ_NEXT(&ifm, ifma_link);
		}
	}
}

static struct in6_multi *
in6_multientry(struct in6_multi *mc)
{
	struct in6_multi multi;
#ifdef HAVE_MLDV2
	struct in6_multi_source src;
	struct router6_info rt6i;
#endif

	KREAD(mc, &multi, struct in6_multi);
	printf("\t\tgroup %s", inet6_n2a(&multi.in6m_addr));
	printf(" refcnt %u\n", multi.in6m_refcount);

#ifdef HAVE_MLDV2
	if (multi.in6m_rti != NULL) {
		KREAD(multi.in6m_rti, &rt6i, struct router_info);
		printf("\t\t\t");
		switch (rt6i.rt6i_type) {
		case MLD_V1_ROUTER:
			printf("mldv1");
			break;
		case MLD_V2_ROUTER:
			printf("mldv2");
			break;
		default:
			printf("mldv?(%d)", rt6i.rt6i_type);
			break;
		}

		if (multi.in6m_source == NULL) {
			printf("\n");
			return(multi.in6m_entry.le_next);
		}

		KREAD(multi.in6m_source, &src, struct in6_multi_source);
		printf(" mode=%s grpjoin=%d\n",
		    src.i6ms_mode == MCAST_INCLUDE ? "include" :
		    src.i6ms_mode == MCAST_EXCLUDE ? "exclude" :
		    "???",
		    src.i6ms_grpjoin);
		in6_addr_slistentry(src.i6ms_cur, "current");
		in6_addr_slistentry(src.i6ms_rec, "recorded");
		in6_addr_slistentry(src.i6ms_in, "included");
		in6_addr_slistentry(src.i6ms_ex, "excluded");
		in6_addr_slistentry(src.i6ms_alw, "allowed");
		in6_addr_slistentry(src.i6ms_blk, "blocked");
		in6_addr_slistentry(src.i6ms_toin, "to-include");
		in6_addr_slistentry(src.i6ms_ex, "to-exclude");
	}
#endif
	return(multi.in6m_entry.le_next);
}

#ifdef HAVE_MLDV2
static void
in6_addr_slistentry(struct in6_addr_slist *ias, char *heading)
{
	struct in6_addr_slist slist;
	struct i6as_head head;
	struct in6_addr_source src;

	if (ias == NULL) {
		printf("\t\t\t\t%s (none)\n", heading);
		return;
	}
	memset(&slist, 0, sizeof(slist));
	KREAD(ias, &slist, struct in6_addr_source);
	printf("\t\t\t\t%s (entry num=%d)\n", heading, slist.numsrc);
	if (slist.numsrc == 0) {
		return;
	}
	KREAD(slist.head, &head, struct i6as_head);

	KREAD(head.lh_first, &src, struct in6_addr_source);
	while (1) {
		printf("\t\t\t\t\tsource %s (ref=%d)\n",
			inet6_n2a(&src.i6as_addr.sin6_addr),
			src.i6as_refcount);
		if (src.i6as_list.le_next == NULL)
			break;
		KREAD(src.i6as_list.le_next, &src, struct in6_addr_source);
	}
	return;
}
#endif /* HAVE_MLDV2 */

#endif /* INET6 */

#ifdef INET

static void
if_addrlist(struct ifaddr *ifap)
{
	struct ifaddr ifa;
	struct sockaddr sa;
	struct in_ifaddr ia;
	struct ifaddr *ifap0;

	if (af && af != AF_INET)
		return;
	ifap0 = ifap;
	while (ifap) {
		KREAD(ifap, &ifa, struct ifaddr);
		if (ifa.ifa_addr == NULL)
			goto nextifap;
		KREAD(ifa.ifa_addr, &sa, struct sockaddr);
		if (sa.sa_family != PF_INET)
			goto nextifap;
		KREAD(ifap, &ia, struct in_ifaddr);
		printf("\tinet %s\n", inet_ntoa(ia.ia_addr.sin_addr));
	nextifap:
		ifap = ifa.ifa_link.tqe_next;
	}
	if (ifap0) {
		struct ifnet ifnet;
		struct ifmultiaddr ifm, *ifmp = 0;
		struct sockaddr_dl sdl;

		KREAD(ifap0, &ifa, struct ifaddr);
		KREAD(ifa.ifa_ifp, &ifnet, struct ifnet);
		if (TAILQ_FIRST(&ifnet.if_multiaddrs))
			ifmp = TAILQ_FIRST(&ifnet.if_multiaddrs);
		while (ifmp) {
			KREAD(ifmp, &ifm, struct ifmultiaddr);
			if (ifm.ifma_addr == NULL)
				goto nextmulti;
			KREAD(ifm.ifma_addr, &sa, struct sockaddr);
			if (sa.sa_family != AF_INET)
				goto nextmulti;
			(void)in_multientry((struct in_multi *)
					    ifm.ifma_protospec);
			if (ifm.ifma_lladdr == 0)
				goto nextmulti;
			KREAD(ifm.ifma_lladdr, &sdl, struct sockaddr_dl);
			printf("\t\t\tmcast-macaddr %s refcnt %d\n",
			       ether_ntoa((struct ether_addr *)LLADDR(&sdl)),
			       ifm.ifma_refcount);
		    nextmulti:
			ifmp = TAILQ_NEXT(&ifm, ifma_link);
		}
	}
}

static struct in_multi *
in_multientry(struct in_multi *mc)
{
	struct in_multi multi;
	struct router_info rti;
#ifdef HAVE_IGMPV3
	struct in_multi_source src;
#endif

	KREAD(mc, &multi, struct in_multi);
	printf("\t\tgroup %s\n", inet_ntoa(multi.inm_addr));

	if (multi.inm_rti != NULL) {
		KREAD(multi.inm_rti, &rti, struct router_info);
		printf("\t\t\t");
		switch (rti.rti_type) {
		case IGMP_V1_ROUTER:
			printf("igmpv1");
			break;
		case IGMP_V2_ROUTER:
			printf("igmpv2");
			break;
#ifdef HAVE_IGMPV3
		case IGMP_V3_ROUTER:
			printf("igmpv3");
			break;
#endif
		default:
			printf("igmpv?(%d)", rti.rti_type);
			break;
		}

#ifdef HAVE_IGMPV3
		if (multi.inm_source == NULL) {
			printf("\n");
			return (multi.inm_list.le_next);
		}

		KREAD(multi.inm_source, &src, struct in_multi_source);
		printf(" mode=%s grpjoin=%d\n",
		    src.ims_mode == MCAST_INCLUDE ? "include" :
		    src.ims_mode == MCAST_EXCLUDE ? "exclude" :
		    "???",
		    src.ims_grpjoin);
		in_addr_slistentry(src.ims_cur, "current");
		in_addr_slistentry(src.ims_rec, "recorded");
		in_addr_slistentry(src.ims_in, "included");
		in_addr_slistentry(src.ims_ex, "excluded");
		in_addr_slistentry(src.ims_alw, "allowed");
		in_addr_slistentry(src.ims_blk, "blocked");
		in_addr_slistentry(src.ims_toin, "to-include");
		in_addr_slistentry(src.ims_ex, "to-exclude");
#else
		printf("\n");
#endif
	}

	return (NULL);
}

#ifdef HAVE_IGMPV3
static void
in_addr_slistentry(struct in_addr_slist *ias, char *heading)
{
	struct in_addr_slist slist;
	struct ias_head head;
	struct in_addr_source src;

	if (ias == NULL) {
		printf("\t\t\t\t%s (none)\n", heading);
		return;
	}
	memset(&slist, 0, sizeof(slist));
	KREAD(ias, &slist, struct in_addr_source);
	printf("\t\t\t\t%s (entry num=%d)\n", heading, slist.numsrc);
	if (slist.numsrc == 0) {
		return;
	}
	KREAD(slist.head, &head, struct ias_head);

	KREAD(head.lh_first, &src, struct in_addr_source);
	while (1) {
		printf("\t\t\t\t\tsource %s (ref=%d)\n",
			inet_ntoa(src.ias_addr.sin_addr), src.ias_refcount);
		if (src.ias_list.le_next == NULL)
			break;
		KREAD(src.ias_list.le_next, &src, struct in_addr_source);
	}
	return;
}
#endif /* HAVE_IGMPV3 */

#endif /* INET */

#endif /* WITH_KVM */

#ifdef INET6
static const char *
inet6_n2a(struct in6_addr *p)
{
	static char buf[NI_MAXHOST];
	struct sockaddr_in6 sin6;
	u_int32_t scopeid;
	const int niflags = NI_NUMERICHOST;

	memset(&sin6, 0, sizeof(sin6));
	sin6.sin6_family = AF_INET6;
	sin6.sin6_len = sizeof(struct sockaddr_in6);
	sin6.sin6_addr = *p;
	if (IN6_IS_ADDR_LINKLOCAL(p) || IN6_IS_ADDR_MC_LINKLOCAL(p) ||
	    IN6_IS_ADDR_MC_NODELOCAL(p)) {
		scopeid = ntohs(*(u_int16_t *)&sin6.sin6_addr.s6_addr[2]);
		if (scopeid) {
			sin6.sin6_scope_id = scopeid;
			sin6.sin6_addr.s6_addr[2] = 0;
			sin6.sin6_addr.s6_addr[3] = 0;
		}
	}
	if (getnameinfo((struct sockaddr *)&sin6, sin6.sin6_len,
			buf, sizeof(buf), NULL, 0, niflags) == 0)
		return buf;
	else
		return "(invalid)";
}
#endif /* INET6 */

static int
ifmcstat_getifmaddrs(void)
{
	char			 thisifname[IFNAMSIZ];
	char			 addrbuf[NI_MAXHOST];
	struct ifaddrs		*ifap, *ifa;
	struct ifmaddrs		*ifmap, *ifma;
	sockunion_t		 lastifasa;
	sockunion_t		*psa, *pgsa, *pllsa, *pifasa;
	char			*pcolon;
	char			*pafname;
	uint32_t		 lastifindex, thisifindex;
	int			 error;

	error = 0;
	ifap = NULL;
	ifmap = NULL;
	lastifindex = 0;
	thisifindex = 0;
	lastifasa.ss.ss_family = AF_UNSPEC;

	if (getifaddrs(&ifap) != 0) {
		warn("getifmaddrs");
		return (-1);
	}

	if (getifmaddrs(&ifmap) != 0) {
		warn("getifmaddrs");
		error = -1;
		goto out;
	}

	for (ifma = ifmap; ifma; ifma = ifma->ifma_next) {
		error = 0;
		if (ifma->ifma_name == NULL || ifma->ifma_addr == NULL)
			continue;

		psa = (sockunion_t *)ifma->ifma_name;
		if (psa->sa.sa_family != AF_LINK) {
			fprintf(stderr,
			    "WARNING: Kernel returned invalid data.\n");
			error = -1;
			break;
		}

		/* Filter on interface name. */
		thisifindex = psa->sdl.sdl_index;
		if (ifindex != 0 && thisifindex != ifindex)
			continue;

		/* Filter on address family. */
		pgsa = (sockunion_t *)ifma->ifma_addr;
		if (af != 0 && pgsa->sa.sa_family != af)
			continue;

		strlcpy(thisifname, link_ntoa(&psa->sdl), IFNAMSIZ);
		pcolon = strchr(thisifname, ':');
		if (pcolon)
			*pcolon = '\0';

		/* Only print the banner for the first ifmaddrs entry. */
		if (lastifindex == 0 || lastifindex != thisifindex) {
			lastifindex = thisifindex;
			fprintf(stdout, "%s:\n", thisifname);
		}

		/*
		 * Currently, multicast joins only take place on the
		 * primary IPv4 address, and only on the link-local IPv6
		 * address, as per IGMPv2/3 and MLDv1/2 semantics.
		 * Therefore, we only look up the primary address on
		 * the first pass.
		 */
		pifasa = NULL;
		for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
			if ((strcmp(ifa->ifa_name, thisifname) != 0) ||
			    (ifa->ifa_addr == NULL) ||
			    (ifa->ifa_addr->sa_family != pgsa->sa.sa_family))
				continue;
			/*
			 * For AF_INET6 only the link-local address should
			 * be returned. If built without IPv6 support,
			 * skip this address entirely.
			 */
			pifasa = (sockunion_t *)ifa->ifa_addr;
			if (pifasa->sa.sa_family == AF_INET6
#ifdef INET6
			    && !IN6_IS_ADDR_LINKLOCAL(&pifasa->sin6.sin6_addr)
#endif
			) {
				pifasa = NULL;
				continue;
			}
			break;
		}
		if (pifasa == NULL)
			continue;	/* primary address not found */

		if (!vflag && pifasa->sa.sa_family == AF_LINK)
			continue;

		/* Parse and print primary address, if not already printed. */
		if (lastifasa.ss.ss_family == AF_UNSPEC ||
		    ((lastifasa.ss.ss_family == AF_LINK &&
		      !sa_dl_equal(&lastifasa.sa, &pifasa->sa)) ||
		     !sa_equal(&lastifasa.sa, &pifasa->sa))) {

			switch (pifasa->sa.sa_family) {
			case AF_INET:
				pafname = "inet";
				break;
			case AF_INET6:
				pafname = "inet6";
				break;
			case AF_LINK:
				pafname = "link";
				break;
			default:
				pafname = "unknown";
				break;
			}

			switch (pifasa->sa.sa_family) {
			case AF_INET6:
#ifdef INET6
			{
				const char *p =
				    inet6_n2a(&pifasa->sin6.sin6_addr);
				strlcpy(addrbuf, p, sizeof(addrbuf));
				break;
			}
#else
			/* FALLTHROUGH */
#endif
			case AF_INET:
			case AF_LINK:
				error = getnameinfo(&pifasa->sa,
				    pifasa->sa.sa_len,
				    addrbuf, sizeof(addrbuf), NULL, 0,
				    NI_NUMERICHOST);
				if (error)
					perror("getnameinfo");
				break;
			default:
				addrbuf[0] = '\0';
				break;
			}

			fprintf(stdout, "\t%s %s\n", pafname, addrbuf);
			lastifasa = *pifasa;
		}

		/* Print this group address. */
#ifdef INET6
		if (pgsa->sa.sa_family == AF_INET6) {
			const char *p = inet6_n2a(&pgsa->sin6.sin6_addr);
			strlcpy(addrbuf, p, sizeof(addrbuf));
		} else
#endif
		{
			error = getnameinfo(&pgsa->sa, pgsa->sa.sa_len,
			    addrbuf, sizeof(addrbuf), NULL, 0, NI_NUMERICHOST);
			if (error)
				perror("getnameinfo");
		}

		fprintf(stdout, "\t\tgroup %s\n", addrbuf);

		/* Link-layer mapping, if present. */
		pllsa = (sockunion_t *)ifma->ifma_lladdr;
		if (pllsa != NULL) {
			error = getnameinfo(&pllsa->sa, pllsa->sa.sa_len,
			    addrbuf, sizeof(addrbuf), NULL, 0, NI_NUMERICHOST);
			fprintf(stdout, "\t\t\tmcast-macaddr %s\n", addrbuf);
		}
	}
out:
	if (ifmap != NULL)
		freeifmaddrs(ifmap);
	if (ifap != NULL)
		freeifaddrs(ifap);

	return (error);
}