ng_echo.c revision 54249 
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@whistle.com>
38 *
39 * $FreeBSD: head/sys/netgraph/ng_echo.c 54249 1999-12-07 05:50:48Z 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_rcvmsg_t	nge_rcvmsg;
59static ng_rcvdata_t	nge_rcvdata;
60static ng_disconnect_t	nge_disconnect;
61
62/* Netgraph type */
63static struct ng_type typestruct = {
64	NG_VERSION,
65	NG_ECHO_NODE_TYPE,
66	NULL,
67	NULL,
68	nge_rcvmsg,
69	NULL,
70	NULL,
71	NULL,
72	NULL,
73	nge_rcvdata,
74	nge_rcvdata,
75	nge_disconnect,
76	NULL
77};
78NETGRAPH_INIT(echo, &typestruct);
79
80/*
81 * Receive control message. We just bounce it back as a reply.
82 */
83static int
84nge_rcvmsg(node_p node, struct ng_mesg *msg, const char *retaddr,
85	   struct ng_mesg **rptr)
86{
87	if (rptr) {
88		msg->header.flags |= NGF_RESP;
89		*rptr = msg;
90	} else {
91		FREE(msg, M_NETGRAPH);
92	}
93	return (0);
94}
95
96/*
97 * Receive data
98 */
99static int
100nge_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
101{
102	int error = 0;
103
104	NG_SEND_DATA(error, hook, m, meta);
105	return (error);
106}
107
108/*
109 * Removal of the last link destroys the nodeo
110 */
111static int
112nge_disconnect(hook_p hook)
113{
114	if (hook->node->numhooks == 0)
115		ng_rmnode(hook->node);
116	return (0);
117}
118
119