peeraddr

static VALUE
ip_peeraddr(VALUE sock)
{
    rb_io_t *fptr;
    struct sockaddr_storage addr;
    socklen_t len = sizeof addr;

    GetOpenFile(sock, fptr);

    if (getpeername(fptr->fd, (struct sockaddr*)&addr, &len) < 0)
        rb_sys_fail("getpeername(2)");
    return ipaddr((struct sockaddr*)&addr, fptr->mode & FMODE_NOREVLOOKUP);
}