/*-
 * Copyright (c) 2005 Robert N. M. Watson
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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/ioctl.h>
#include <sys/linker.h>
#include <sys/socket.h>

#include <net/if.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>

/*
 * Regression test to reproduce problems associated with the removal of a
 * network interface being used by an active multicast socket.  This proves
 * to be somewhat complicated, as we need a multicast-capable synthetic
 * network device that can be torn down on demand, in order that the test
 * program can open a multicast socket, join a group on the interface, tear
 * down the interface, and then close the multicast socket.  We use the
 * if_disc ("discard") synthetic interface for this purpose.
 *
 * Because potential solutions to this problem require separate handling for
 * different IP socket types, we actually run the test twice: once for UDP
 * sockets, and once for raw IP sockets.
 */

/*
 * XXX: The following hopefully don't conflict with the local configuration.
 */
#define MULTICAST_IP    "224.100.100.100"
#define DISC_IP         "192.0.2.100"
#define DISC_MASK       "255.255.255.0"
#define DISC_IFNAME     "disc"
#define DISC_IFUNIT     100

static int
disc_setup(void)
{
        struct ifreq ifr;
        int s;

        if (kldload("if_disc") < 0) {
                switch (errno) {
                case EEXIST:
                        break;
                default:
                        warn("disc_setup: kldload(if_disc)");
                        return (-1);
                }
        }

        s = socket(PF_INET, SOCK_RAW, 0);
        if (s < 0) {
                warn("disc_setup: socket(PF_INET, SOCK_RAW, 0)");
                return (-1);
        }

        bzero(&ifr, sizeof(ifr));
        snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", DISC_IFNAME,
            DISC_IFUNIT);

        if (ioctl(s, SIOCIFCREATE, &ifr) < 0) {
                warn("disc_setup: ioctl(%s, SIOCIFCREATE)", ifr.ifr_name);
                close(s);
                return (-1);
        }

        close(s);
        return (0);
}

static void
disc_done(void)
{
        struct ifreq ifr;
        int s;

        s = socket(PF_INET, SOCK_RAW, 0);
        if (s < 0) {
                warn("disc_done: socket(PF_INET, SOCK_RAW, 0)");
                return;
        }

        bzero(&ifr, sizeof(ifr));
        snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", DISC_IFNAME,
            DISC_IFUNIT);

        if (ioctl(s, SIOCIFDESTROY, &ifr) < 0)
                warn("disc_done: ioctl(%s, SIOCIFDESTROY)", ifr.ifr_name);
        close(s);
}

/*
 * Configure an IP address and netmask on a network interface.
 */
static int
ifconfig_inet(char *ifname, int ifunit, char *ip, char *netmask)
{
        struct sockaddr_in *sinp;
        struct ifaliasreq ifra;
        int s;

        s = socket(PF_INET, SOCK_RAW, 0);
        if (s < 0) {
                warn("ifconfig_inet: socket(PF_INET, SOCK_RAW, 0)");
                return (-1);
        }

        bzero(&ifra, sizeof(ifra));
        snprintf(ifra.ifra_name, sizeof(ifra.ifra_name), "%s%d", ifname,
            ifunit);

        sinp = (struct sockaddr_in *)&ifra.ifra_addr;
        sinp->sin_family = AF_INET;
        sinp->sin_len = sizeof(ifra.ifra_addr);
        sinp->sin_addr.s_addr = inet_addr(ip);

        sinp = (struct sockaddr_in *)&ifra.ifra_mask;
        sinp->sin_family = AF_INET;
        sinp->sin_len = sizeof(ifra.ifra_addr);
        sinp->sin_addr.s_addr = inet_addr(netmask);

        if (ioctl(s, SIOCAIFADDR, &ifra) < 0) {
                warn("ifconfig_inet: ioctl(%s%d, SIOCAIFADDR, %s)", ifname,
                    ifunit, ip);
                close(s);
                return (-1);
        }

        close(s);
        return (0);
}

static int
multicast_open(int *sockp, int type, const char *type_string)
{
        struct ip_mreq imr;
        int sock;

        sock = socket(PF_INET, type, 0);
        if (sock < 0) {
                warn("multicast_test: socket(PF_INET, %s, 0)", type_string);
                return (-1);
        }

        bzero(&imr, sizeof(imr));
        imr.imr_multiaddr.s_addr = inet_addr(MULTICAST_IP);
        imr.imr_interface.s_addr = inet_addr(DISC_IP);

        if (setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP, &imr,
            sizeof(imr)) < 0) {
                warn("multicast_test: setsockopt(IPPROTO_IP, "
                    "IP_ADD_MEMBERSHIP, {%s, %s})", MULTICAST_IP, DISC_IP);
                close(sock);
                return (-1);
        }

        *sockp = sock;
        return (0);
}

static void
multicast_close(int udp_socket)
{

        close(udp_socket);
}

static int
test_sock_type(int type, const char *type_string)
{
        int sock;

        if (disc_setup() < 0)
                return (-1);

        if (ifconfig_inet(DISC_IFNAME, DISC_IFUNIT, DISC_IP, DISC_MASK) < 0) {
                disc_done();
                return (-1);
        }

        if (multicast_open(&sock, type, type_string) < 0) {
                disc_done();
                return (-1);
        }

        /*
         * Tear down the interface first, then close the multicast socket and
         * see if we make it to the end of the function.
         */
        disc_done();
        multicast_close(sock);

        printf("test_sock_type(%s) passed\n", type_string);

        return (0);
}

int
main(int argc, char *argv[])
{

        if (test_sock_type(SOCK_RAW, "SOCK_RAW") < 0)
                return (-1);

        if (test_sock_type(SOCK_DGRAM, "SOCK_DGRAM") < 0)
                return (-1);

        return (0);
}