/* DF-3309: getsockopt(IPV6_MULTICAST_LOOP) echoes ip6_defmcasthlim when no
 * multicast options are attached (ip6_output.c:2511-2515 copy-paste bug). */
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
int main(void) {
    int s = socket(AF_INET6, SOCK_DGRAM, 0);
    if (s < 0) { perror("socket"); exit(1); }
    unsigned int loop = 0xdeadbeef;
    socklen_t l = sizeof(loop);
    if (getsockopt(s, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &loop, &l) < 0) {
        perror("getsockopt"); exit(1);
    }
    printf("IPV6_MULTICAST_LOOP = %u (l=%u)\n", loop, (unsigned)l);
    return (loop == 1) ? 0 : 2;  /* 1 == IPV6_DEFAULT_MULTICAST_LOOP */
}