ipv6.c

#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>

int main()
{
        int s, s1;
        int rc;
        struct sockaddr_in6 sa = {
                .sin6_family = AF_INET6,
                .sin6_port = 0x1234,
        };
        struct sockaddr_in6 sa1 = { 0 };
        socklen_t sz;
        ssize_t rsz;
        char buf[1024];

        s = socket(AF_INET6, SOCK_STREAM, 0);
        if (s < 0) {
                perror("socket");
                abort();
        }
        rc = bind(s, (void *)&sa, sizeof(sa));
        if (rc < 0) {
                perror("bind");
                abort();
        }
        rc = listen(s, 5);
        if (rc < 0) {
                perror("listen");
                abort();
        }
        sz = sizeof(sa1);
        s1 = accept(s, (void *)&sa1, &sz);
        if (s1 < 0) {
                perror("accept");
                abort();
        }
        for (;;) {
                rsz = read(s1, buf, sizeof(buf));
                if (rsz < 0) {
                        perror("read");
                        abort();
                } else if (rsz == 0) {
                        break;
                }
                write(STDOUT_FILENO, buf, rsz);
        }
        return 0;
}

Makefile

ipv6: ipv6.c