FreeBSD/Linux Kernel Cross Reference
sys/netgraph/ng_echo.c

     
     /*
      * ng_echo.c
      *
      * Copyright (c) 1996-1999 Whistle Communications, Inc.
      * All rights reserved.
      * 
      * Subject to the following obligations and disclaimer of warranty, use and
      * redistribution of this software, in source or object code forms, with or
     * without modifications are expressly permitted by Whistle Communications;
     * provided, however, that:
     * 1. Any and all reproductions of the source or object code must include the
     *    copyright notice above and the following disclaimer of warranties; and
     * 2. No rights are granted, in any manner or form, to use Whistle
     *    Communications, Inc. trademarks, including the mark "WHISTLE
     *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
     *    such appears in the above copyright notice or in the software.
     * 
     * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
     * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
     * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
     * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
     * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
     * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
     * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
     * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
     * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
     * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
     * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
     * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
     * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
     * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
     * OF SUCH DAMAGE.
     *
     * Author: Julian Elisher <julian@freebsd.org>
     *
     * $FreeBSD: releng/5.3/sys/netgraph/ng_echo.c 136588 2004-10-16 08:43:07Z cvs2svn $
     * $Whistle: ng_echo.c,v 1.13 1999/11/01 09:24:51 julian Exp $
     */
    
    /*
     * Netgraph "echo" node
     *
     * This node simply bounces data and messages back to whence they came.
     */
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/kernel.h>
    #include <sys/malloc.h>
    #include <sys/mbuf.h>
    #include <netgraph/ng_message.h>
    #include <netgraph/netgraph.h>
    #include <netgraph/ng_echo.h>
    
    /* Netgraph methods */
    static ng_constructor_t nge_cons;
    static ng_rcvmsg_t      nge_rcvmsg;
    static ng_rcvdata_t     nge_rcvdata;
    static ng_disconnect_t  nge_disconnect;
    
    /* Netgraph type */
    static struct ng_type typestruct = {
            .version =      NG_ABI_VERSION,
            .name =         NG_ECHO_NODE_TYPE,
            .constructor =  nge_cons,
            .rcvmsg =       nge_rcvmsg,
            .rcvdata =      nge_rcvdata,
            .disconnect =   nge_disconnect,
    };
    NETGRAPH_INIT(echo, &typestruct);
    
    static int
    nge_cons(node_p node)
    {
            return (0);
    }
    
    /*
     * Receive control message. We just bounce it back as a reply.
     */
    static int
    nge_rcvmsg(node_p node, item_p item, hook_p lasthook)
    {
            struct ng_mesg *msg;
            int error = 0;
    
            NGI_GET_MSG(item, msg);
            msg->header.flags |= NGF_RESP;
            NG_RESPOND_MSG(error, node, item, msg);
            return (error);
    }
    
    /*
     * Receive data
     */
    static int
   nge_rcvdata(hook_p hook, item_p item)
   {
           int error = 0;
   
           NG_FWD_ITEM_HOOK(error, item, hook);
           return (0);
   }
   
   /*
    * Removal of the last link destroys the nodeo
    */
   static int
   nge_disconnect(hook_p hook)
   {
           if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
           && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) {
                   ng_rmnode_self(NG_HOOK_NODE(hook));
           }
           return (0);
   }
   

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