ng_echo.c revision 53913 
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 53913 1999-11-30 02:45:32Z archie $
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/errno.h>
52#include <sys/kernel.h>
53#include <sys/malloc.h>
54#include <sys/mbuf.h>
55#include <sys/syslog.h>
56#include <netgraph/ng_message.h>
57#include <netgraph/netgraph.h>
58#include <netgraph/ng_echo.h>
59
60/* Netgraph methods */
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	NG_VERSION,
68	NG_ECHO_NODE_TYPE,
69	NULL,
70	NULL,
71	nge_rcvmsg,
72	NULL,
73	NULL,
74	NULL,
75	NULL,
76	nge_rcvdata,
77	nge_rcvdata,
78	nge_disconnect,
79	NULL
80};
81NETGRAPH_INIT(echo, &typestruct);
82
83/*
84 * Receive control message. We just bounce it back as a reply.
85 */
86static int
87nge_rcvmsg(node_p node, struct ng_mesg *msg, const char *retaddr,
88	   struct ng_mesg **rptr)
89{
90	if (rptr) {
91		msg->header.flags |= NGF_RESP;
92		*rptr = msg;
93	} else {
94		FREE(msg, M_NETGRAPH);
95	}
96	return (0);
97}
98
99/*
100 * Receive data
101 */
102static int
103nge_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
104{
105	int error = 0;
106
107	NG_SEND_DATA(error, hook, m, meta);
108	return (error);
109}
110
111/*
112 * Removal of the last link destroys the nodeo
113 */
114static int
115nge_disconnect(hook_p hook)
116{
117	if (hook->node->numhooks == 0)
118		ng_rmnode(hook->node);
119	return (0);
120}
121
122