ng_echo.c revision 129823 
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 129823 2004-05-29 00:51:19Z 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/systm.h>
51#include <sys/kernel.h>
52#include <sys/malloc.h>
53#include <sys/mbuf.h>
54#include <netgraph/ng_message.h>
55#include <netgraph/netgraph.h>
56#include <netgraph/ng_echo.h>
57
58/* Netgraph methods */
59static ng_constructor_t	nge_cons;
60static ng_rcvmsg_t	nge_rcvmsg;
61static ng_rcvdata_t	nge_rcvdata;
62static ng_disconnect_t	nge_disconnect;
63
64/* Netgraph type */
65static struct ng_type typestruct = {
66	.version =	NG_ABI_VERSION,
67	.name =		NG_ECHO_NODE_TYPE,
68	.constructor =	nge_cons,
69	.rcvmsg =	nge_rcvmsg,
70	.rcvdata =	nge_rcvdata,
71	.disconnect =	nge_disconnect,
72};
73NETGRAPH_INIT(echo, &typestruct);
74
75static int
76nge_cons(node_p node)
77{
78	return (0);
79}
80
81/*
82 * Receive control message. We just bounce it back as a reply.
83 */
84static int
85nge_rcvmsg(node_p node, item_p item, hook_p lasthook)
86{
87	struct ng_mesg *msg;
88	int error = 0;
89
90	NGI_GET_MSG(item, msg);
91	msg->header.flags |= NGF_RESP;
92	NG_RESPOND_MSG(error, node, item, msg);
93	return (error);
94}
95
96/*
97 * Receive data
98 */
99static int
100nge_rcvdata(hook_p hook, item_p item)
101{
102	int error = 0;
103
104	NG_FWD_ITEM_HOOK(error, item, hook);
105	return (0);
106}
107
108/*
109 * Removal of the last link destroys the nodeo
110 */
111static int
112nge_disconnect(hook_p hook)
113{
114	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
115	&& (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) {
116		ng_rmnode_self(NG_HOOK_NODE(hook));
117	}
118	return (0);
119}
120
121