sys/netgraph/hole/ng_hole.c

   1
   2 /*
   3  * ng_hole.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_hole.c,v 1.4.2.1 2000/10/24 18:36:45 julian Exp $
  40  * $DragonFly: src/sys/netgraph/hole/ng_hole.c,v 1.3 2003/08/07 21:17:31 dillon Exp $
  41  * $Whistle: ng_hole.c,v 1.10 1999/11/01 09:24:51 julian Exp $
  42  */
  43
  44 /*
  45  * This node is a 'black hole' that simply discards everything it receives
  46  */
  47
  48 #include <sys/param.h>
  49 #include <sys/kernel.h>
  50 #include <sys/malloc.h>
  51 #include <sys/mbuf.h>
  52 #include <netgraph/ng_message.h>
  53 #include <netgraph/netgraph.h>
  54 #include "ng_hole.h"
  55
  56 /* Netgraph methods */
  57 static ng_rcvdata_t     ngh_rcvdata;
  58 static ng_disconnect_t  ngh_disconnect;
  59
  60 static struct ng_type typestruct = {
  61         NG_VERSION,
  62         NG_HOLE_NODE_TYPE,
  63         NULL,
  64         NULL,
  65         NULL,
  66         NULL,
  67         NULL,
  68         NULL,
  69         NULL,
  70         ngh_rcvdata,
  71         ngh_rcvdata,
  72         ngh_disconnect,
  73         NULL
  74 };
  75 NETGRAPH_INIT(hole, &typestruct);
  76
  77 /*
  78  * Receive data
  79  */
  80 static int
  81 ngh_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
  82 {
  83         NG_FREE_DATA(m, meta);
  84         return 0;
  85 }
  86
  87 /*
  88  * Hook disconnection
  89  */
  90 static int
  91 ngh_disconnect(hook_p hook)
  92 {
  93         if (hook->node->numhooks == 0)
  94                 ng_rmnode(hook->node);
  95         return (0);
  96 }