ng_echo.c revision 70700 
1
2/*
3 * ng_echo.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_echo.c 70700 2001-01-06 00:46:47Z julian $
40 * $Whistle: ng_echo.c,v 1.13 1999/11/01 09:24:51 julian Exp $
41 */
42
43/*
44 * Netgraph "echo" node
45 *
46 * This node simply bounces data and messages back to whence they came.
47 */
48
49#include <sys/param.h>
50#include <sys/kernel.h>
51#include <sys/malloc.h>
52#include <sys/mbuf.h>
53#include <netgraph/ng_message.h>
54#include <netgraph/netgraph.h>
55#include <netgraph/ng_echo.h>
56
57/* Netgraph methods */
58static ng_constructor_t	nge_cons;
59static ng_rcvmsg_t	nge_rcvmsg;
60static ng_rcvdata_t	nge_rcvdata;
61static ng_disconnect_t	nge_disconnect;
62
63/* Netgraph type */
64static struct ng_type typestruct = {
65	NG_ABI_VERSION,
66	NG_ECHO_NODE_TYPE,
67	NULL,
68	nge_cons,
69	nge_rcvmsg,
70	NULL,
71	NULL,
72	NULL,
73	NULL,
74	nge_rcvdata,
75	nge_disconnect,
76	NULL
77};
78NETGRAPH_INIT(echo, &typestruct);
79
80static int
81nge_cons(node_p node)
82{
83	return (0);
84}
85
86/*
87 * Receive control message. We just bounce it back as a reply.
88 */
89static int
90nge_rcvmsg(node_p node, item_p item, hook_p lasthook)
91{
92	struct ng_mesg *msg;
93	int error = 0;
94
95	NGI_GET_MSG(item, msg);
96	msg->header.flags |= NGF_RESP;
97	NG_RESPOND_MSG(error, node, item, msg);
98	return (error);
99}
100
101/*
102 * Receive data
103 */
104static int
105nge_rcvdata(hook_p hook, item_p item)
106{
107	int error = 0;
108
109	NG_FWD_DATA(error, item, hook);
110	return (0);
111}
112
113/*
114 * Removal of the last link destroys the nodeo
115 */
116static int
117nge_disconnect(hook_p hook)
118{
119	if ((hook->node->numhooks == 0)
120	&& ((hook->node->flags & NG_INVALID) == 0)) {
121		ng_rmnode_self(hook->node);
122	}
123	return (0);
124}
125
126