/*      $KAME: mld6.c,v 1.15 2003/04/02 11:29:54 suz Exp $      */

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (C) 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/param.h>
#include <sys/uio.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/time.h>
#include <ifaddrs.h>
#include <unistd.h>
#include <signal.h>

#include <net/if.h>

#include <netinet/in.h>
#include <netinet/ip6.h>
#include <netinet/icmp6.h>

#include  <arpa/inet.h>

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <err.h>

/* portability with older KAME headers */
#ifndef MLD_LISTENER_QUERY
#define MLD_LISTENER_QUERY      MLD6_LISTENER_QUERY
#define MLD_LISTENER_REPORT     MLD6_LISTENER_REPORT
#define MLD_LISTENER_DONE       MLD6_LISTENER_DONE
#define MLD_MTRACE_RESP         MLD6_MTRACE_RESP
#define MLD_MTRACE              MLD6_MTRACE
#define mld_hdr         mld6_hdr
#define mld_type        mld6_type
#define mld_code        mld6_code
#define mld_cksum       mld6_cksum
#define mld_maxdelay    mld6_maxdelay
#define mld_reserved    mld6_reserved
#define mld_addr        mld6_addr
#endif
#ifndef IP6OPT_ROUTER_ALERT
#define IP6OPT_ROUTER_ALERT     IP6OPT_RTALERT
#endif

struct msghdr m;
struct sockaddr_in6 dst;
struct mld_hdr mldh;
struct in6_addr maddr = IN6ADDR_ANY_INIT, any = IN6ADDR_ANY_INIT;
struct ipv6_mreq mreq;
u_short ifindex;
int s;

#define QUERY_RESPONSE_INTERVAL 10000

void make_msg(int index, struct in6_addr *addr, u_int type, struct in6_addr *qaddr);
void usage(void);
void dump(int);
void quit(int);

int
main(int argc, char *argv[])
{
        int i;
        struct icmp6_filter filt;
        u_int hlim = 1;
        fd_set fdset;
        struct itimerval itimer;
        u_int type;
        int ch;
        struct in6_addr *qaddr = &maddr;

        type = MLD_LISTENER_QUERY;
        while ((ch = getopt(argc, argv, "dgr")) != -1) {
                switch (ch) {
                case 'd':
                        if (type != MLD_LISTENER_QUERY) {
                                printf("Can not specify -d with -r\n");
                                return 1;
                        }
                        type = MLD_LISTENER_DONE;
                        break;
                case 'g':
                        qaddr = &any;
                        break;
                case 'r':
                        if (type != MLD_LISTENER_QUERY) {
                                printf("Can not specify -r with -d\n");
                                return 1;
                        }
                        type = MLD_LISTENER_REPORT;
                        break;
                default:
                        usage();
                        /*NOTREACHED*/
                }
        }

        argv += optind;
        argc -= optind;
        
        if (argc != 1 && argc != 2)
                usage();

        ifindex = (u_short)if_nametoindex(argv[0]);
        if (ifindex == 0)
                usage();
        if (argc == 2 && inet_pton(AF_INET6, argv[1], &maddr) != 1)
                usage();
        if (type != MLD_LISTENER_QUERY && qaddr != &maddr) {
                printf("Can not specify -g with -d or -r\n");
                return 1;
        }

        if ((s = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0)
                err(1, "socket");

        if (setsockopt(s, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &hlim,
                       sizeof(hlim)) == -1)
                err(1, "setsockopt(IPV6_MULTICAST_HOPS)");

        if (IN6_IS_ADDR_UNSPECIFIED(&maddr)) {
                if (inet_pton(AF_INET6, "ff02::1", &maddr) != 1)
                        errx(1, "inet_pton failed");
        }

        mreq.ipv6mr_multiaddr = maddr;
        mreq.ipv6mr_interface = ifindex;
        if (setsockopt(s, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq,
                       sizeof(mreq)) == -1)
                err(1, "setsockopt(IPV6_JOIN_GROUP)");

        ICMP6_FILTER_SETBLOCKALL(&filt);
        ICMP6_FILTER_SETPASS(ICMP6_MEMBERSHIP_QUERY, &filt);
        ICMP6_FILTER_SETPASS(ICMP6_MEMBERSHIP_REPORT, &filt);
        ICMP6_FILTER_SETPASS(ICMP6_MEMBERSHIP_REDUCTION, &filt);
        if (setsockopt(s, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
                        sizeof(filt)) < 0)
                err(1, "setsockopt(ICMP6_FILTER)");

        make_msg(ifindex, &maddr, type, qaddr);

        if (sendmsg(s, &m, 0) < 0)
                err(1, "sendmsg");

        itimer.it_value.tv_sec =  QUERY_RESPONSE_INTERVAL / 1000;
        itimer.it_interval.tv_sec = 0;
        itimer.it_interval.tv_usec = 0;
        itimer.it_value.tv_usec = 0;

        (void)signal(SIGALRM, quit);
        (void)setitimer(ITIMER_REAL, &itimer, NULL);

        FD_ZERO(&fdset);
        if (s >= FD_SETSIZE)
                errx(1, "descriptor too big");
        for (;;) {
                FD_SET(s, &fdset);
                if ((i = select(s + 1, &fdset, NULL, NULL, NULL)) < 0)
                        perror("select");
                if (i == 0)
                        continue;
                else
                        dump(s);
        }
}

void
make_msg(int index, struct in6_addr *addr, u_int type, struct in6_addr *qaddr)
{
        static struct iovec iov[2];
        static u_char *cmsgbuf;
        int cmsglen, hbhlen = 0;
        void *hbhbuf = NULL, *optp = NULL;
        int currentlen;
        struct in6_pktinfo *pi;
        struct cmsghdr *cmsgp;
        u_short rtalert_code = htons(IP6OPT_RTALERT_MLD);
        struct ifaddrs *ifa, *ifap;
        struct in6_addr src;

        dst.sin6_len = sizeof(dst);
        dst.sin6_family = AF_INET6;
        dst.sin6_addr = *addr;
        m.msg_name = (caddr_t)&dst;
        m.msg_namelen = dst.sin6_len;
        iov[0].iov_base = (caddr_t)&mldh;
        iov[0].iov_len = sizeof(mldh);
        m.msg_iov = iov;
        m.msg_iovlen = 1;

        bzero(&mldh, sizeof(mldh));
        mldh.mld_type = type & 0xff;
        mldh.mld_maxdelay = htons(QUERY_RESPONSE_INTERVAL);
        mldh.mld_addr = *qaddr;

        /* MLD packet should be advertised from linklocal address */
        getifaddrs(&ifa);
        for (ifap = ifa; ifap; ifap = ifap->ifa_next) {
                if (index != if_nametoindex(ifap->ifa_name))
                        continue;

                if (ifap->ifa_addr->sa_family != AF_INET6)
                        continue;
                if (!IN6_IS_ADDR_LINKLOCAL(&((struct sockaddr_in6 *)
                                            ifap->ifa_addr)->sin6_addr))
                        continue;
                break;
        }
        if (ifap == NULL)
                errx(1, "no linklocal address is available");
        memcpy(&src, &((struct sockaddr_in6 *)ifap->ifa_addr)->sin6_addr,
               sizeof(src));
        freeifaddrs(ifa);
#ifdef __KAME__
        /* remove embedded ifindex */
        src.s6_addr[2] = src.s6_addr[3] = 0;
#endif

        if ((hbhlen = inet6_opt_init(NULL, 0)) == -1)
                errx(1, "inet6_opt_init(0) failed");
        if ((hbhlen = inet6_opt_append(NULL, 0, hbhlen, IP6OPT_ROUTER_ALERT, 2,
                                       2, NULL)) == -1)
                errx(1, "inet6_opt_append(0) failed");
        if ((hbhlen = inet6_opt_finish(NULL, 0, hbhlen)) == -1)
                errx(1, "inet6_opt_finish(0) failed");
        cmsglen = CMSG_SPACE(sizeof(struct in6_pktinfo)) + CMSG_SPACE(hbhlen);

        if ((cmsgbuf = malloc(cmsglen)) == NULL)
                errx(1, "can't allocate enough memory for cmsg");
        cmsgp = (struct cmsghdr *)cmsgbuf;
        m.msg_control = (caddr_t)cmsgbuf;
        m.msg_controllen = cmsglen;
        /* specify the outgoing interface */
        cmsgp->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
        cmsgp->cmsg_level = IPPROTO_IPV6;
        cmsgp->cmsg_type = IPV6_PKTINFO;
        pi = (struct in6_pktinfo *)CMSG_DATA(cmsgp);
        pi->ipi6_ifindex = index;
        memcpy(&pi->ipi6_addr, &src, sizeof(pi->ipi6_addr));
        /* specify to insert router alert option in a hop-by-hop opt hdr. */
        cmsgp = CMSG_NXTHDR(&m, cmsgp);
        cmsgp->cmsg_len = CMSG_LEN(hbhlen);
        cmsgp->cmsg_level = IPPROTO_IPV6;
        cmsgp->cmsg_type = IPV6_HOPOPTS;
        hbhbuf = CMSG_DATA(cmsgp);
        if ((currentlen = inet6_opt_init(hbhbuf, hbhlen)) == -1)
                errx(1, "inet6_opt_init(len = %d) failed", hbhlen);
        if ((currentlen = inet6_opt_append(hbhbuf, hbhlen, currentlen,
                                           IP6OPT_ROUTER_ALERT, 2,
                                           2, &optp)) == -1)
                errx(1, "inet6_opt_append(currentlen = %d, hbhlen = %d) failed",
                     currentlen, hbhlen);
        (void)inet6_opt_set_val(optp, 0, &rtalert_code, sizeof(rtalert_code));
        if ((currentlen = inet6_opt_finish(hbhbuf, hbhlen, currentlen)) == -1)
                errx(1, "inet6_opt_finish(buf) failed");
}

void
dump(int s)
{
        int i;
        struct mld_hdr *mld;
        u_char buf[1024];
        struct sockaddr_in6 from;
        int from_len = sizeof(from);
        char ntop_buf[256];

        if ((i = recvfrom(s, buf, sizeof(buf), 0,
                          (struct sockaddr *)&from,
                          &from_len)) < 0)
                return;

        if (i < sizeof(struct mld_hdr)) {
                printf("too short!\n");
                return;
        }

        mld = (struct mld_hdr *)buf;

        printf("from %s, ", inet_ntop(AF_INET6, &from.sin6_addr,
                                      ntop_buf, sizeof(ntop_buf)));

        switch (mld->mld_type) {
        case ICMP6_MEMBERSHIP_QUERY:
                printf("type=Multicast Listener Query, ");
                break;
        case ICMP6_MEMBERSHIP_REPORT:
                printf("type=Multicast Listener Report, ");
                break;
        case ICMP6_MEMBERSHIP_REDUCTION:
                printf("type=Multicast Listener Done, ");
                break;
        }
        printf("addr=%s\n", inet_ntop(AF_INET6, &mld->mld_addr,
                                    ntop_buf, sizeof(ntop_buf)));
        
        fflush(stdout);
}

void
quit(int signum __unused)
{
        mreq.ipv6mr_multiaddr = maddr;
        mreq.ipv6mr_interface = ifindex;
        if (setsockopt(s, IPPROTO_IPV6, IPV6_LEAVE_GROUP, &mreq,
                       sizeof(mreq)) == -1)
                err(1, "setsockopt(IPV6_LEAVE_GROUP)");

        exit(0);
}

void
usage(void)
{
        (void)fprintf(stderr, "usage: mld6query [-dgr] ifname [addr]\n");
        exit(1);
}