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  * $DragonFly: src/sys/netgraph/echo/ng_echo.c,v 1.3 2003/08/07 21:17:31 dillon Exp $
  41  * $Whistle: ng_echo.c,v 1.13 1999/11/01 09:24:51 julian Exp $
  42  */
  43
  44 /*
  45  * Netgraph "echo" node
  46  *
  47  * This node simply bounces data and messages back to whence they came.
  48  */
  49
  50 #include <sys/param.h>
  51 #include <sys/kernel.h>
  52 #include <sys/malloc.h>
  53 #include <sys/mbuf.h>
  54 #include <netgraph/ng_message.h>
  55 #include <netgraph/netgraph.h>
  56 #include "ng_echo.h"
  57
  58 /* Netgraph methods */
  59 static ng_rcvmsg_t      nge_rcvmsg;
  60 static ng_rcvdata_t     nge_rcvdata;
  61 static ng_disconnect_t  nge_disconnect;
  62
  63 /* Netgraph type */
  64 static struct ng_type typestruct = {
  65         NG_VERSION,
  66         NG_ECHO_NODE_TYPE,
  67         NULL,
  68         NULL,
  69         nge_rcvmsg,
  70         NULL,
  71         NULL,
  72         NULL,
  73         NULL,
  74         nge_rcvdata,
  75         nge_rcvdata,
  76         nge_disconnect,
  77         NULL
  78 };
  79 NETGRAPH_INIT(echo, &typestruct);
  80
  81 /*
  82  * Receive control message. We just bounce it back as a reply.
  83  */
  84 static int
  85 nge_rcvmsg(node_p node, struct ng_mesg *msg, const char *retaddr,
  86            struct ng_mesg **rptr)
  87 {
  88         if (rptr) {
  89                 msg->header.flags |= NGF_RESP;
  90                 *rptr = msg;
  91         } else {
  92                 FREE(msg, M_NETGRAPH);
  93         }
  94         return (0);
  95 }
  96
  97 /*
  98  * Receive data
  99  */
 100 static int
 101 nge_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
 102 {
 103         int error = 0;
 104
 105         NG_SEND_DATA(error, hook, m, meta);
 106         return (error);
 107 }
 108
 109 /*
 110  * Removal of the last link destroys the nodeo
 111  */
 112 static int
 113 nge_disconnect(hook_p hook)
 114 {
 115         if (hook->node->numhooks == 0)
 116                 ng_rmnode(hook->node);
 117         return (0);
 118 }
 119