ng_hole.c revision 70700 
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 70700 2001-01-06 00:46:47Z 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_constructor_t	ngh_cons;
57static ng_rcvdata_t	ngh_rcvdata;
58static ng_disconnect_t	ngh_disconnect;
59
60static struct ng_type typestruct = {
61	NG_ABI_VERSION,
62	NG_HOLE_NODE_TYPE,
63	NULL,		/* modeventhand_t */
64	ngh_cons,	/* ng_constructor_t */
65	NULL,		/* ng_rcvmsg_t */
66	NULL,		/* ng_shutdown_t */
67	NULL,		/* ng_newhook_t */
68	NULL,		/* ng_findhook_t */
69	NULL,		/* ng_connect_t */
70	ngh_rcvdata,	/* ng_rcvdata_t */
71	ngh_disconnect,	/* ng_disconnect_t */
72	NULL		/* ng_cmdlist */
73};
74NETGRAPH_INIT(hole, &typestruct);
75
76/*
77 * Be obliging. but no work to do.
78 */
79static int
80ngh_cons(node_p node)
81{
82	return(0);
83}
84
85/*
86 * Receive data
87 */
88static int
89ngh_rcvdata(hook_p hook, item_p item)
90{
91	NG_FREE_ITEM(item);
92	return 0;
93}
94
95/*
96 * Hook disconnection
97 */
98static int
99ngh_disconnect(hook_p hook)
100{
101	if (hook->node->numhooks == 0)
102		ng_rmnode_self(hook->node);
103	return (0);
104}
105