/*-
 * Copyright (c) 2007 Bruce M. Simpson
 * 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/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/ioctl.h>

#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/ethernet.h>

#include <err.h>
#include <errno.h>
#include <getopt.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <ifaddrs.h>

static int dorandom = 0;
static int verbose = 0;
static char *ifname = NULL;

/*
 * The test tool exercises IP-level socket options by interrogating the
 * getsockopt()/setsockopt() APIs.  It does not currently test that the
 * intended semantics of each option are implemented (i.e., that setting IP
 * options on the socket results in packets with the desired IP options in
 * it).
 */

/*
 * get_socket() is a wrapper function that returns a socket of the specified
 * type, and created with or without restored root privilege (if running
 * with a real uid of root and an effective uid of some other user).  This
 * us to test whether the same rights are granted using a socket with a
 * privileged cached credential vs. a socket with a regular credential.
 */
#define PRIV_ASIS       0
#define PRIV_GETROOT    1
static int
get_socket_unpriv(int type)
{

        return (socket(PF_INET, type, 0));
}

static int
get_socket_priv(int type)
{
        uid_t olduid;
        int sock;

        if (getuid() != 0)
                errx(-1, "get_sock_priv: running without real uid 0");
        
        olduid = geteuid();
        if (seteuid(0) < 0)
                err(-1, "get_sock_priv: seteuid(0)");

        sock = socket(PF_INET, type, 0);

        if (seteuid(olduid) < 0)
                err(-1, "get_sock_priv: seteuid(%d)", olduid);

        return (sock);
}

static int
get_socket(int type, int priv)
{

        if (priv)
                return (get_socket_priv(type));
        else
                return (get_socket_unpriv(type));
}

union sockunion {
        struct sockaddr_storage ss;
        struct sockaddr         sa;
        struct sockaddr_dl      sdl;
};
typedef union sockunion sockunion_t;

static void
test_ether_multi(int sock)
{
        struct ifreq ifr;
        struct sockaddr_dl *dlp;
        struct ether_addr ea;
        struct ifmaddrs *ifma, *ifmap;
        int found;

        /* Choose an 802 multicast address. */
        if (dorandom) {
                uint32_t mac4;

                srandomdev();
                mac4 = random();
                ea.octet[0] = 0x01;
                ea.octet[1] = 0x80;
                ea.octet[2] = ((mac4 >> 24 & 0xFF));
                ea.octet[3] = ((mac4 >> 16 & 0xFF));
                ea.octet[4] = ((mac4 >> 8 & 0xFF));
                ea.octet[5] = (mac4 & 0xFF);
        } else {
                struct ether_addr *nep = ether_aton("01:80:DE:FA:CA:7E");
                ea = *nep;
        }

        /* Fill out ifreq, and fill out 802 group address. */
        memset(&ifr, 0, sizeof(struct ifreq));
        strlcpy(&ifr.ifr_name[0], ifname, IFNAMSIZ);
        dlp = (struct sockaddr_dl *)&ifr.ifr_addr;
        memset(dlp, 0, sizeof(struct sockaddr_dl));
        dlp->sdl_len = sizeof(struct sockaddr_dl);
        dlp->sdl_family = AF_LINK;
        dlp->sdl_alen = sizeof(struct ether_addr);
        memcpy(LLADDR(dlp), &ea, sizeof(struct ether_addr));

        /* Join an 802 group. */
        if (ioctl(sock, SIOCADDMULTI, &ifr) < 0) {
                warn("can't add ethernet multicast membership");
                return;
        }

        /* Check that we joined the group by calling getifmaddrs(). */
        found = 0;
        if (getifmaddrs(&ifmap) != 0) {
                warn("getifmaddrs()");
        } else {
                for (ifma = ifmap; ifma; ifma = ifma->ifma_next) {
                        sockunion_t *psa = (sockunion_t *)ifma->ifma_addr;
                        if (ifma->ifma_name == NULL || psa == NULL)
                                continue;

                        if (psa->sa.sa_family != AF_LINK ||
                            psa->sdl.sdl_alen != ETHER_ADDR_LEN)
                                continue;

                        if (bcmp(LLADDR(&psa->sdl), LLADDR(dlp),
                            ETHER_ADDR_LEN) == 0) {
                                found = 1;
                                break;
                        }
                }
                freeifmaddrs(ifmap);
        }
        if (!found) {
                warnx("group membership for %s not returned by getifmaddrs()",
                   ether_ntoa(&ea));
        }

        /* Fill out ifreq, and fill out 802 group address. */
        memset(&ifr, 0, sizeof(struct ifreq));
        strlcpy(&ifr.ifr_name[0], ifname, IFNAMSIZ);
        dlp = (struct sockaddr_dl *)&ifr.ifr_addr;
        memset(dlp, 0, sizeof(struct sockaddr_dl));
        dlp->sdl_len = sizeof(struct sockaddr_dl);
        dlp->sdl_family = AF_LINK;
        dlp->sdl_alen = sizeof(struct ether_addr);
        memcpy(LLADDR(dlp), &ea, sizeof(struct ether_addr));

        /* Leave an 802 group. */
        if (ioctl(sock, SIOCDELMULTI, &ifr) < 0)
                warn("can't delete ethernet multicast membership");

}

static void
testsuite(int priv)
{
        int sock;

        sock = get_socket(SOCK_DGRAM, 0);
        if (sock == -1)
                err(-1, "get_socket(SOCK_DGRAM) for test_ether_multi()", priv);
        test_ether_multi(sock);
        close(sock);
}

static void
usage()
{

        fprintf(stderr, "usage: ethermulti -i ifname [-r] [-v]\n");
        exit(EXIT_FAILURE);
}

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

        while ((ch = getopt(argc, argv, "i:rv")) != -1) {
                switch (ch) {
                case 'i':
                        ifname = optarg;
                        break;
                case 'r':
                        dorandom = 1;   /* introduce non-determinism */
                        break;
                case 'v':
                        verbose = 1;
                        break;
                default:
                        usage();
                }
        }
        if (ifname == NULL)
                usage();

        printf("1..1\n");
        if (geteuid() != 0) {
                errx(1, "Not running as root, can't run tests as non-root");
                /*NOTREACHED*/
        } else {
                fprintf(stderr,
                    "Running tests with ruid %d euid %d sock uid 0\n",
                    getuid(), geteuid());
                testsuite(PRIV_ASIS);
        }
        printf("ok 1 - ethermulti\n");
        exit(0);
}