Function select_padding_cb

modules/http2/h2_session.c:680–709

#endif

static ssize_t select_padding_cb(nghttp2_session *ngh2, 
                                 const nghttp2_frame *frame, 
                                 size_t max_payloadlen, void *user_data)
{
    h2_session *session = user_data;
    size_t frame_len = frame->hd.length + H2_FRAME_HDR_LEN; /* the total length without padding */
    size_t padded_len = frame_len;

    /* Determine # of padding bytes to append to frame. Unless session->padding_always
     * the number my be capped by the ui.write_size that currently applies. 
     */
    if (session->padding_max) {
        int n = ap_random_pick(0, session->padding_max);
        padded_len = H2MIN(max_payloadlen + H2_FRAME_HDR_LEN, frame_len + n); 
    }

    if (padded_len != frame_len) {
        if (!session->padding_always && session->io.write_size 
            && (padded_len > session->io.write_size)
            && (frame_len <= session->io.write_size)) {
            padded_len = session->io.write_size;
        }
        ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, session->c1,
                      "select padding from [%d, %d]: %d (frame length: 0x%04x, write size: %d)",
                      (int)frame_len, (int)max_payloadlen+H2_FRAME_HDR_LEN,
                      (int)(padded_len - frame_len), (int)padded_len, (int)session->io.write_size);
        return padded_len - H2_FRAME_HDR_LEN;
    }
    return frame->hd.length;
}

#define NGH2_SET_CALLBACK(callbacks, name, fn)\
nghttp2_session_callbacks_set_##name##_callback(callbacks, fn)