OVS处理各个openflow消息的详细代码在 ofproto/ofproto.c 中：

static enum ofperr

handle_openflow__(struct ofconn *ofconn, const struct ofpbuf *msg)

{

    const struct ofp_header *oh = msg->data;

    enum ofptype type;

    enum ofperr error;

    error = ofptype_decode(&type, oh);

    if (error) {

        return error;

    }

    switch (type) {

        /* OpenFlow requests. */

    case OFPTYPE_ECHO_REQUEST:

        return handle_echo_request(ofconn, oh);

    case OFPTYPE_FEATURES_REQUEST:

        return handle_features_request(ofconn, oh);

    case OFPTYPE_GET_CONFIG_REQUEST:

        return handle_get_config_request(ofconn, oh);

    case OFPTYPE_SET_CONFIG:

        return handle_set_config(ofconn, oh);

    case OFPTYPE_PACKET_OUT:

        return handle_packet_out(ofconn, oh);

    case OFPTYPE_PORT_MOD:

        return handle_port_mod(ofconn, oh);

    case OFPTYPE_FLOW_MOD:

        return handle_flow_mod(ofconn, oh);

    case OFPTYPE_BARRIER_REQUEST:

        return handle_barrier_request(ofconn, oh);

        /* OpenFlow replies. */

    case OFPTYPE_ECHO_REPLY:

        return 0;

        /* Nicira extension requests. */

    case OFPTYPE_ROLE_REQUEST:

        return handle_role_request(ofconn, oh);

    case OFPTYPE_FLOW_MOD_TABLE_ID:

        return handle_nxt_flow_mod_table_id(ofconn, oh);

    case OFPTYPE_SET_FLOW_FORMAT:

        return handle_nxt_set_flow_format(ofconn, oh);

    case OFPTYPE_SET_PACKET_IN_FORMAT:

        return handle_nxt_set_packet_in_format(ofconn, oh);

    case OFPTYPE_SET_CONTROLLER_ID:

        return handle_nxt_set_controller_id(ofconn, oh);

    case OFPTYPE_FLOW_AGE:

        /* Nothing to do. */

        return 0;

    case OFPTYPE_FLOW_MONITOR_CANCEL:

        return handle_flow_monitor_cancel(ofconn, oh);

    case OFPTYPE_SET_ASYNC_CONFIG:

        return handle_nxt_set_async_config(ofconn, oh);

        /* Statistics requests. */

    case OFPTYPE_DESC_STATS_REQUEST:

        return handle_desc_stats_request(ofconn, oh);

    case OFPTYPE_FLOW_STATS_REQUEST:

        return handle_flow_stats_request(ofconn, oh);

    case OFPTYPE_AGGREGATE_STATS_REQUEST:

        return handle_aggregate_stats_request(ofconn, oh);

    case OFPTYPE_TABLE_STATS_REQUEST:

        return handle_table_stats_request(ofconn, oh);

    case OFPTYPE_PORT_STATS_REQUEST:

        return handle_port_stats_request(ofconn, oh);

    case OFPTYPE_QUEUE_STATS_REQUEST:

        return handle_queue_stats_request(ofconn, oh);

    case OFPTYPE_PORT_DESC_STATS_REQUEST:

        return handle_port_desc_stats_request(ofconn, oh);

    case OFPTYPE_FLOW_MONITOR_STATS_REQUEST:

        return handle_flow_monitor_request(ofconn, oh);

    case OFPTYPE_HELLO:

    case OFPTYPE_ERROR:

    case OFPTYPE_FEATURES_REPLY:

    case OFPTYPE_GET_CONFIG_REPLY:

    case OFPTYPE_PACKET_IN:

    case OFPTYPE_FLOW_REMOVED:

    case OFPTYPE_PORT_STATUS:

    case OFPTYPE_BARRIER_REPLY:

    case OFPTYPE_DESC_STATS_REPLY:

    case OFPTYPE_FLOW_STATS_REPLY:

    case OFPTYPE_QUEUE_STATS_REPLY:

    case OFPTYPE_PORT_STATS_REPLY:

    case OFPTYPE_TABLE_STATS_REPLY:

    case OFPTYPE_AGGREGATE_STATS_REPLY:

    case OFPTYPE_PORT_DESC_STATS_REPLY:

    case OFPTYPE_ROLE_REPLY:

    case OFPTYPE_FLOW_MONITOR_PAUSED:

    case OFPTYPE_FLOW_MONITOR_RESUMED:

    case OFPTYPE_FLOW_MONITOR_STATS_REPLY:

    default:

        return OFPERR_OFPBRC_BAD_TYPE;

    }

}

http://blog.csdn.net/vonzhoufz/article/details/29190281