sys/netgraph7/ng_echo.c

   1 /*
   2  * ng_echo.c
   3  */
   4
   5 /*-
   6  * Copyright (c) 1996-1999 Whistle Communications, Inc.
   7  * All rights reserved.
   8  *
   9  * Subject to the following obligations and disclaimer of warranty, use and
  10  * redistribution of this software, in source or object code forms, with or
  11  * without modifications are expressly permitted by Whistle Communications;
  12  * provided, however, that:
  13  * 1. Any and all reproductions of the source or object code must include the
  14  *    copyright notice above and the following disclaimer of warranties; and
  15  * 2. No rights are granted, in any manner or form, to use Whistle
  16  *    Communications, Inc. trademarks, including the mark "WHISTLE
  17  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
  18  *    such appears in the above copyright notice or in the software.
  19  *
  20  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
  21  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
  22  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
  23  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
  24  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
  25  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
  26  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
  27  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
  28  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
  29  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
  30  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
  31  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
  32  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
  33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  35  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
  36  * OF SUCH DAMAGE.
  37  *
  38  * Author: Julian Elisher <julian@freebsd.org>
  39  *
  40  * $FreeBSD: src/sys/netgraph/ng_echo.c,v 1.13 2005/04/15 10:14:00 glebius Exp $
  41  * $DragonFly: src/sys/netgraph7/ng_echo.c,v 1.2 2008/06/26 23:05:35 dillon Exp $
  42  * $Whistle: ng_echo.c,v 1.13 1999/11/01 09:24:51 julian Exp $
  43  */
  44
  45 /*
  46  * Netgraph "echo" node
  47  *
  48  * This node simply bounces data and messages back to whence they came.
  49  */
  50
  51 #include <sys/param.h>
  52 #include <sys/systm.h>
  53 #include <sys/kernel.h>
  54 #include <sys/malloc.h>
  55 #include <sys/mbuf.h>
  56 #include "ng_message.h"
  57 #include "netgraph.h"
  58 #include "ng_echo.h"
  59
  60 /* Netgraph methods */
  61 static ng_constructor_t nge_cons;
  62 static ng_rcvmsg_t      nge_rcvmsg;
  63 static ng_rcvdata_t     nge_rcvdata;
  64 static ng_disconnect_t  nge_disconnect;
  65
  66 /* Netgraph type */
  67 static struct ng_type typestruct = {
  68         .version =      NG_ABI_VERSION,
  69         .name =         NG_ECHO_NODE_TYPE,
  70         .constructor =  nge_cons,
  71         .rcvmsg =       nge_rcvmsg,
  72         .rcvdata =      nge_rcvdata,
  73         .disconnect =   nge_disconnect,
  74 };
  75 NETGRAPH_INIT(echo, &typestruct);
  76
  77 static int
  78 nge_cons(node_p node)
  79 {
  80         return (0);
  81 }
  82
  83 /*
  84  * Receive control message. We just bounce it back as a reply.
  85  */
  86 static int
  87 nge_rcvmsg(node_p node, item_p item, hook_p lasthook)
  88 {
  89         struct ng_mesg *msg;
  90         int error = 0;
  91
  92         NGI_GET_MSG(item, msg);
  93         msg->header.flags |= NGF_RESP;
  94         NG_RESPOND_MSG(error, node, item, msg);
  95         return (error);
  96 }
  97
  98 /*
  99  * Receive data
 100  */
 101 static int
 102 nge_rcvdata(hook_p hook, item_p item)
 103 {
 104         int error;
 105
 106         NG_FWD_ITEM_HOOK(error, item, hook);
 107         return (error);
 108 }
 109
 110 /*
 111  * Removal of the last link destroys the nodeo
 112  */
 113 static int
 114 nge_disconnect(hook_p hook)
 115 {
 116         if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
 117         && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) {
 118                 ng_rmnode_self(NG_HOOK_NODE(hook));
 119         }
 120         return (0);
 121 }
 122