sys/netgraph/echo/ng_echo.c

   1
   2 /*
   3  * ng_echo.c
   4  *
   5  * Copyright (c) 1996-1999 Whistle Communications, Inc.
   6  * All rights reserved.
   7  *
   8  * Subject to the following obligations and disclaimer of warranty, use and
   9  * redistribution of this software, in source or object code forms, with or
  10  * without modifications are expressly permitted by Whistle Communications;
  11  * provided, however, that:
  12  * 1. Any and all reproductions of the source or object code must include the
  13  *    copyright notice above and the following disclaimer of warranties; and
  14  * 2. No rights are granted, in any manner or form, to use Whistle
  15  *    Communications, Inc. trademarks, including the mark "WHISTLE
  16  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
  17  *    such appears in the above copyright notice or in the software.
  18  *
  19  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
  20  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
  21  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
  22  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
  23  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
  24  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
  25  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
  26  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
  27  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
  28  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
  29  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
  30  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
  31  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
  32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  34  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
  35  * OF SUCH DAMAGE.
  36  *
  37  * Author: Julian Elisher <julian@freebsd.org>
  38  *
  39  * $FreeBSD: src/sys/netgraph/ng_echo.c,v 1.4.2.1 2000/10/24 18:36:44 julian Exp $
  40  * $Whistle: ng_echo.c,v 1.13 1999/11/01 09:24:51 julian Exp $
  41  */
  42
  43 /*
  44  * Netgraph "echo" node
  45  *
  46  * This node simply bounces data and messages back to whence they came.
  47  */
  48
  49 #include <sys/param.h>
  50 #include <sys/kernel.h>
  51 #include <sys/malloc.h>
  52 #include <sys/mbuf.h>
  53 #include <netgraph/ng_message.h>
  54 #include <netgraph/netgraph.h>
  55 #include "ng_echo.h"
  56
  57 /* Netgraph methods */
  58 static ng_rcvmsg_t      nge_rcvmsg;
  59 static ng_rcvdata_t     nge_rcvdata;
  60 static ng_disconnect_t  nge_disconnect;
  61
  62 /* Netgraph type */
  63 static struct ng_type typestruct = {
  64         NG_VERSION,
  65         NG_ECHO_NODE_TYPE,
  66         NULL,
  67         NULL,
  68         nge_rcvmsg,
  69         NULL,
  70         NULL,
  71         NULL,
  72         NULL,
  73         nge_rcvdata,
  74         nge_rcvdata,
  75         nge_disconnect,
  76         NULL
  77 };
  78 NETGRAPH_INIT(echo, &typestruct);
  79
  80 /*
  81  * Receive control message. We just bounce it back as a reply.
  82  */
  83 static int
  84 nge_rcvmsg(node_p node, struct ng_mesg *msg, const char *retaddr,
  85            struct ng_mesg **rptr)
  86 {
  87         if (rptr) {
  88                 msg->header.flags |= NGF_RESP;
  89                 *rptr = msg;
  90         } else {
  91                 kfree(msg, M_NETGRAPH);
  92         }
  93         return (0);
  94 }
  95
  96 /*
  97  * Receive data
  98  */
  99 static int
 100 nge_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
 101 {
 102         int error = 0;
 103
 104         NG_SEND_DATA(error, hook, m, meta);
 105         return (error);
 106 }
 107
 108 /*
 109  * Removal of the last link destroys the nodeo
 110  */
 111 static int
 112 nge_disconnect(hook_p hook)
 113 {
 114         if (hook->node->numhooks == 0)
 115                 ng_rmnode(hook->node);
 116         return (0);
 117 }
 118