1/*
2 * ng_echo.c
3 */
4
5/*-
6 * Copyright (c) 1996-1999 Whistle Communications, Inc.
7 * All rights reserved.
8 *
9 * Subject to the following obligations and disclaimer of warranty, use and
10 * redistribution of this software, in source or object code forms, with or
11 * without modifications are expressly permitted by Whistle Communications;
12 * provided, however, that:
13 * 1. Any and all reproductions of the source or object code must include the
14 *    copyright notice above and the following disclaimer of warranties; and
15 * 2. No rights are granted, in any manner or form, to use Whistle
16 *    Communications, Inc. trademarks, including the mark "WHISTLE
17 *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
18 *    such appears in the above copyright notice or in the software.
19 *
20 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
21 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
22 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
23 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
24 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
25 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
26 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
27 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
28 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
29 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
30 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
31 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
32 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
36 * OF SUCH DAMAGE.
37 *
38 * Author: Julian Elisher <julian@freebsd.org>
39 *
40 * $FreeBSD$
41 * $Whistle: ng_echo.c,v 1.13 1999/11/01 09:24:51 julian Exp $
42 */
43
44/*
45 * Netgraph "echo" node
46 *
47 * This node simply bounces data and messages back to whence they came.
48 */
49
50#include <sys/param.h>
51#include <sys/systm.h>
52#include <sys/kernel.h>
53#include <sys/malloc.h>
54#include <sys/mbuf.h>
55#include <netgraph/ng_message.h>
56#include <netgraph/netgraph.h>
57#include <netgraph/ng_echo.h>
58
59/* Netgraph methods */
60static ng_constructor_t	nge_cons;
61static ng_rcvmsg_t	nge_rcvmsg;
62static ng_rcvdata_t	nge_rcvdata;
63static ng_disconnect_t	nge_disconnect;
64
65/* Netgraph type */
66static struct ng_type typestruct = {
67	.version =	NG_ABI_VERSION,
68	.name =		NG_ECHO_NODE_TYPE,
69	.constructor =	nge_cons,
70	.rcvmsg =	nge_rcvmsg,
71	.rcvdata =	nge_rcvdata,
72	.disconnect =	nge_disconnect,
73};
74NETGRAPH_INIT(echo, &typestruct);
75
76static int
77nge_cons(node_p node)
78{
79	return (0);
80}
81
82/*
83 * Receive control message. We just bounce it back as a reply.
84 */
85static int
86nge_rcvmsg(node_p node, item_p item, hook_p lasthook)
87{
88	struct ng_mesg *msg;
89	int error = 0;
90
91	NGI_GET_MSG(item, msg);
92	msg->header.flags |= NGF_RESP;
93	NG_RESPOND_MSG(error, node, item, msg);
94	return (error);
95}
96
97/*
98 * Receive data
99 */
100static int
101nge_rcvdata(hook_p hook, item_p item)
102{
103	int error;
104
105	NG_FWD_ITEM_HOOK(error, item, hook);
106	return (error);
107}
108
109/*
110 * Removal of the last link destroys the nodeo
111 */
112static int
113nge_disconnect(hook_p hook)
114{
115	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
116	&& (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) {
117		ng_rmnode_self(NG_HOOK_NODE(hook));
118	}
119	return (0);
120}
121
122