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  * $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/systm.h>
  52 #include <sys/kernel.h>
  53 #include <sys/malloc.h>
  54 #include <sys/mbuf.h>
  55 #include <netgraph/ng_message.h>
  56 #include <netgraph/netgraph.h>
  57 #include <netgraph/ng_echo.h>
  58
  59 /* Netgraph methods */
  60 static ng_constructor_t nge_cons;
  61 static ng_rcvmsg_t      nge_rcvmsg;
  62 static ng_rcvdata_t     nge_rcvdata;
  63 static ng_disconnect_t  nge_disconnect;
  64
  65 /* Netgraph type */
  66 static struct ng_type typestruct = {
  67         .version =      NG_ABI_VERSION,
  68         .name =         NG_ECHO_NODE_TYPE,
  69         .constructor =  nge_cons,
  70         .rcvmsg =       nge_rcvmsg,
  71         .rcvdata =      nge_rcvdata,
  72         .disconnect =   nge_disconnect,
  73 };
  74 NETGRAPH_INIT(echo, &typestruct);
  75
  76 static int
  77 nge_cons(node_p node)
  78 {
  79         return (0);
  80 }
  81
  82 /*
  83  * Receive control message. We just bounce it back as a reply.
  84  */
  85 static int
  86 nge_rcvmsg(node_p node, item_p item, hook_p lasthook)
  87 {
  88         struct ng_mesg *msg;
  89         int error = 0;
  90
  91         NGI_GET_MSG(item, msg);
  92         msg->header.flags |= NGF_RESP;
  93         NG_RESPOND_MSG(error, node, item, msg);
  94         return (error);
  95 }
  96
  97 /*
  98  * Receive data
  99  */
 100 static int
 101 nge_rcvdata(hook_p hook, item_p item)
 102 {
 103         int error;
 104
 105         NG_FWD_ITEM_HOOK(error, item, hook);
 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 ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
 116         && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) {
 117                 ng_rmnode_self(NG_HOOK_NODE(hook));
 118         }
 119         return (0);
 120 }
 121