ngx_int_t
ngx_connection_local_sockaddr(ngx_connection_t *c, ngx_str_t *s,
    ngx_uint_t port)
{
    socklen_t             len;
    ngx_uint_t            addr;
    u_char                sa[NGX_SOCKADDRLEN];
    struct sockaddr_in   *sin;
#if (NGX_HAVE_INET6)
    ngx_uint_t            i;
    struct sockaddr_in6  *sin6;
#endif

    switch (c->local_sockaddr->sa_family) {

#if (NGX_HAVE_INET6)
    case AF_INET6:
        sin6 = (struct sockaddr_in6 *) c->local_sockaddr;
        len = sizeof(struct sockaddr_in6);

        for (addr = 0, i = 0; addr == 0 && i < 16; i++) {
            addr |= sin6->sin6_addr.s6_addr[i];
        }

        break;
#endif

    default: /* AF_INET */
        sin = (struct sockaddr_in *) c->local_sockaddr;
        len = sizeof(struct sockaddr_in);
        addr = sin->sin_addr.s_addr;
        break;
    }

    if (addr == 0) {

        len = NGX_SOCKADDRLEN;

        if (getsockname(c->fd, (struct sockaddr *) &sa, &len) == -1) {
            ngx_connection_error(c, ngx_socket_errno, "getsockname() failed");
            return NGX_ERROR;
        }

        c->local_sockaddr = ngx_palloc(c->pool, len);
        if (c->local_sockaddr == NULL) {
            return NGX_ERROR;
        }

        ngx_memcpy(c->local_sockaddr, &sa, len);
    }

    if (s == NULL) {
        return NGX_OK;
    }

    s->len = ngx_sock_ntop(c->local_sockaddr, len, s->data, s->len, port);

    return NGX_OK;
}