ng_hole.c revision 69922 
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: head/sys/netgraph/ng_hole.c 69922 2000-12-12 18:52:14Z julian $
40 * $Whistle: ng_hole.c,v 1.10 1999/11/01 09:24:51 julian Exp $
41 */
42
43/*
44 * This node is a 'black hole' that simply discards everything it receives
45 */
46
47#include <sys/param.h>
48#include <sys/kernel.h>
49#include <sys/malloc.h>
50#include <sys/mbuf.h>
51#include <netgraph/ng_message.h>
52#include <netgraph/netgraph.h>
53#include <netgraph/ng_hole.h>
54
55/* Netgraph methods */
56static ng_rcvdata_t	ngh_rcvdata;
57static ng_disconnect_t	ngh_disconnect;
58
59static struct ng_type typestruct = {
60	NG_VERSION,
61	NG_HOLE_NODE_TYPE,
62	NULL,
63	NULL,
64	NULL,
65	NULL,
66	NULL,
67	NULL,
68	NULL,
69	ngh_rcvdata,
70	ngh_disconnect,
71	NULL
72};
73NETGRAPH_INIT(hole, &typestruct);
74
75/*
76 * Receive data
77 */
78static int
79ngh_rcvdata(hook_p hook, struct mbuf *m, meta_p meta,
80		struct mbuf **ret_m, meta_p *ret_meta, struct ng_mesg **resp)
81{
82	NG_FREE_DATA(m, meta);
83	return 0;
84}
85
86/*
87 * Hook disconnection
88 */
89static int
90ngh_disconnect(hook_p hook)
91{
92	if (hook->node->numhooks == 0)
93		ng_rmnode(hook->node);
94	return (0);
95}
96