static int vnc_display_get_addresses(QemuOpts *opts,
                                     bool reverse,
                                     SocketAddress ***retsaddr,
                                     size_t *retnsaddr,
                                     SocketAddress ***retwsaddr,
                                     size_t *retnwsaddr,
                                     Error **errp)
{
    SocketAddress *saddr = NULL;
    SocketAddress *wsaddr = NULL;
    QemuOptsIter addriter;
    const char *addr;
    int to = qemu_opt_get_number(opts, "to", 0);
    bool has_ipv4 = qemu_opt_get(opts, "ipv4");
    bool has_ipv6 = qemu_opt_get(opts, "ipv6");
    bool ipv4 = qemu_opt_get_bool(opts, "ipv4", false);
    bool ipv6 = qemu_opt_get_bool(opts, "ipv6", false);
    size_t i;
    int displaynum = -1;
    int ret = -1;

    *retsaddr = NULL;
    *retnsaddr = 0;
    *retwsaddr = NULL;
    *retnwsaddr = 0;

    addr = qemu_opt_get(opts, "vnc");
    if (addr == NULL || g_str_equal(addr, "none")) {
        ret = 0;
        goto cleanup;
    }
    if (qemu_opt_get(opts, "websocket") &&
        !qcrypto_hash_supports(QCRYPTO_HASH_ALG_SHA1)) {
        error_setg(errp,
                   "SHA1 hash support is required for websockets");
        goto cleanup;
    }

    qemu_opt_iter_init(&addriter, opts, "vnc");
    while ((addr = qemu_opt_iter_next(&addriter)) != NULL) {
        int rv;
        rv = vnc_display_get_address(addr, false, reverse, 0, to,
                                     has_ipv4, has_ipv6,
                                     ipv4, ipv6,
                                     &saddr, errp);
        if (rv < 0) {
            goto cleanup;
        }
        /* Historical compat - first listen address can be used
         * to set the default websocket port
         */
        if (displaynum == -1) {
            displaynum = rv;
        }
        *retsaddr = g_renew(SocketAddress *, *retsaddr, *retnsaddr + 1);
        (*retsaddr)[(*retnsaddr)++] = saddr;
    }

    /* If we had multiple primary displays, we don't do defaults
     * for websocket, and require explicit config instead. */
    if (*retnsaddr > 1) {
        displaynum = -1;
    }

    qemu_opt_iter_init(&addriter, opts, "websocket");
    while ((addr = qemu_opt_iter_next(&addriter)) != NULL) {
        if (vnc_display_get_address(addr, true, reverse, displaynum, to,
                                    has_ipv4, has_ipv6,
                                    ipv4, ipv6,
                                    &wsaddr, errp) < 0) {
            goto cleanup;
        }

        /* Historical compat - if only a single listen address was
         * provided, then this is used to set the default listen
         * address for websocket too
         */
        if (*retnsaddr == 1 &&
            (*retsaddr)[0]->type == SOCKET_ADDRESS_TYPE_INET &&
            wsaddr->type == SOCKET_ADDRESS_TYPE_INET &&
            g_str_equal(wsaddr->u.inet.host, "") &&
            !g_str_equal((*retsaddr)[0]->u.inet.host, "")) {
            g_free(wsaddr->u.inet.host);
            wsaddr->u.inet.host = g_strdup((*retsaddr)[0]->u.inet.host);
        }

        *retwsaddr = g_renew(SocketAddress *, *retwsaddr, *retnwsaddr + 1);
        (*retwsaddr)[(*retnwsaddr)++] = wsaddr;
    }

    ret = 0;
 cleanup:
    if (ret < 0) {
        for (i = 0; i < *retnsaddr; i++) {
            qapi_free_SocketAddress((*retsaddr)[i]);
        }
        g_free(*retsaddr);
        for (i = 0; i < *retnwsaddr; i++) {
            qapi_free_SocketAddress((*retwsaddr)[i]);
        }
        g_free(*retwsaddr);
        *retsaddr = *retwsaddr = NULL;
        *retnsaddr = *retnwsaddr = 0;
    }
    return ret;
}